bpf.h

   1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
   2/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
   3 *
   4 * This program is free software; you can redistribute it and/or
   5 * modify it under the terms of version 2 of the GNU General Public
   6 * License as published by the Free Software Foundation.
   7 */
   8#ifndef _UAPI__LINUX_BPF_H__
   9#define _UAPI__LINUX_BPF_H__
  10
  11#include <linux/types.h>
  12#include <linux/bpf_common.h>
  13
  14/* Extended instruction set based on top of classic BPF */
  15
  16/* instruction classes */
  17#define BPF_JMP32	0x06	/* jmp mode in word width */
  18#define BPF_ALU64	0x07	/* alu mode in double word width */
  19
  20/* ld/ldx fields */
  21#define BPF_DW		0x18	/* double word (64-bit) */
  22#define BPF_MEMSX	0x80	/* load with sign extension */
  23#define BPF_ATOMIC	0xc0	/* atomic memory ops - op type in immediate */
  24#define BPF_XADD	0xc0	/* exclusive add - legacy name */
  25
  26/* alu/jmp fields */
  27#define BPF_MOV		0xb0	/* mov reg to reg */
  28#define BPF_ARSH	0xc0	/* sign extending arithmetic shift right */
  29
  30/* change endianness of a register */
  31#define BPF_END		0xd0	/* flags for endianness conversion: */
  32#define BPF_TO_LE	0x00	/* convert to little-endian */
  33#define BPF_TO_BE	0x08	/* convert to big-endian */
  34#define BPF_FROM_LE	BPF_TO_LE
  35#define BPF_FROM_BE	BPF_TO_BE
  36
  37/* jmp encodings */
  38#define BPF_JNE		0x50	/* jump != */
  39#define BPF_JLT		0xa0	/* LT is unsigned, '<' */
  40#define BPF_JLE		0xb0	/* LE is unsigned, '<=' */
  41#define BPF_JSGT	0x60	/* SGT is signed '>', GT in x86 */
  42#define BPF_JSGE	0x70	/* SGE is signed '>=', GE in x86 */
  43#define BPF_JSLT	0xc0	/* SLT is signed, '<' */
  44#define BPF_JSLE	0xd0	/* SLE is signed, '<=' */
  45#define BPF_JCOND	0xe0	/* conditional pseudo jumps: may_goto, goto_or_nop */
  46#define BPF_CALL	0x80	/* function call */
  47#define BPF_EXIT	0x90	/* function return */
  48
  49/* atomic op type fields (stored in immediate) */
  50#define BPF_FETCH	0x01	/* not an opcode on its own, used to build others */
  51#define BPF_XCHG	(0xe0 | BPF_FETCH)	/* atomic exchange */
  52#define BPF_CMPXCHG	(0xf0 | BPF_FETCH)	/* atomic compare-and-write */
  53
  54#define BPF_LOAD_ACQ	0x100	/* load-acquire */
  55#define BPF_STORE_REL	0x110	/* store-release */
  56
  57enum bpf_cond_pseudo_jmp {
  58	BPF_MAY_GOTO = 0,
  59};
  60
  61/* Register numbers */
  62enum {
  63	BPF_REG_0 = 0,
  64	BPF_REG_1,
  65	BPF_REG_2,
  66	BPF_REG_3,
  67	BPF_REG_4,
  68	BPF_REG_5,
  69	BPF_REG_6,
  70	BPF_REG_7,
  71	BPF_REG_8,
  72	BPF_REG_9,
  73	BPF_REG_10,
  74	__MAX_BPF_REG,
  75};
  76
  77/* BPF has 10 general purpose 64-bit registers and stack frame. */
  78#define MAX_BPF_REG	__MAX_BPF_REG
  79
  80struct bpf_insn {
  81	__u8	code;		/* opcode */
  82	__u8	dst_reg:4;	/* dest register */
  83	__u8	src_reg:4;	/* source register */
  84	__s16	off;		/* signed offset */
  85	__s32	imm;		/* signed immediate constant */
  86};
  87
  88/* Deprecated: use struct bpf_lpm_trie_key_u8 (when the "data" member is needed for
  89 * byte access) or struct bpf_lpm_trie_key_hdr (when using an alternative type for
  90 * the trailing flexible array member) instead.
  91 */
  92struct bpf_lpm_trie_key {
  93	__u32	prefixlen;	/* up to 32 for AF_INET, 128 for AF_INET6 */
  94	__u8	data[0];	/* Arbitrary size */
  95};
  96
  97/* Header for bpf_lpm_trie_key structs */
  98struct bpf_lpm_trie_key_hdr {
  99	__u32	prefixlen;
 100};
 101
 102/* Key of an a BPF_MAP_TYPE_LPM_TRIE entry, with trailing byte array. */
 103struct bpf_lpm_trie_key_u8 {
 104	union {
 105		struct bpf_lpm_trie_key_hdr	hdr;
 106		__u32				prefixlen;
 107	};
 108	__u8	data[];		/* Arbitrary size */
 109};
 110
 111struct bpf_cgroup_storage_key {
 112	__u64	cgroup_inode_id;	/* cgroup inode id */
 113	__u32	attach_type;		/* program attach type (enum bpf_attach_type) */
 114};
 115
 116enum bpf_cgroup_iter_order {
 117	BPF_CGROUP_ITER_ORDER_UNSPEC = 0,
 118	BPF_CGROUP_ITER_SELF_ONLY,		/* process only a single object. */
 119	BPF_CGROUP_ITER_DESCENDANTS_PRE,	/* walk descendants in pre-order. */
 120	BPF_CGROUP_ITER_DESCENDANTS_POST,	/* walk descendants in post-order. */
 121	BPF_CGROUP_ITER_ANCESTORS_UP,		/* walk ancestors upward. */
 122};
 123
 124union bpf_iter_link_info {
 125	struct {
 126		__u32	map_fd;
 127	} map;
 128	struct {
 129		enum bpf_cgroup_iter_order order;
 130
 131		/* At most one of cgroup_fd and cgroup_id can be non-zero. If
 132		 * both are zero, the walk starts from the default cgroup v2
 133		 * root. For walking v1 hierarchy, one should always explicitly
 134		 * specify cgroup_fd.
 135		 */
 136		__u32	cgroup_fd;
 137		__u64	cgroup_id;
 138	} cgroup;
 139	/* Parameters of task iterators. */
 140	struct {
 141		__u32	tid;
 142		__u32	pid;
 143		__u32	pid_fd;
 144	} task;
 145};
 146
 147/* BPF syscall commands, see bpf(2) man-page for more details. */
 148/**
 149 * DOC: eBPF Syscall Preamble
 150 *
 151 * The operation to be performed by the **bpf**\ () system call is determined
 152 * by the *cmd* argument. Each operation takes an accompanying argument,
 153 * provided via *attr*, which is a pointer to a union of type *bpf_attr* (see
 154 * below). The size argument is the size of the union pointed to by *attr*.
 155 */
 156/**
 157 * DOC: eBPF Syscall Commands
 158 *
 159 * BPF_MAP_CREATE
 160 *	Description
 161 *		Create a map and return a file descriptor that refers to the
 162 *		map. The close-on-exec file descriptor flag (see **fcntl**\ (2))
 163 *		is automatically enabled for the new file descriptor.
 164 *
 165 *		Applying **close**\ (2) to the file descriptor returned by
 166 *		**BPF_MAP_CREATE** will delete the map (but see NOTES).
 167 *
 168 *	Return
 169 *		A new file descriptor (a nonnegative integer), or -1 if an
 170 *		error occurred (in which case, *errno* is set appropriately).
 171 *
 172 * BPF_MAP_LOOKUP_ELEM
 173 *	Description
 174 *		Look up an element with a given *key* in the map referred to
 175 *		by the file descriptor *map_fd*.
 176 *
 177 *		The *flags* argument may be specified as one of the
 178 *		following:
 179 *
 180 *		**BPF_F_LOCK**
 181 *			Look up the value of a spin-locked map without
 182 *			returning the lock. This must be specified if the
 183 *			elements contain a spinlock.
 184 *
 185 *	Return
 186 *		Returns zero on success. On error, -1 is returned and *errno*
 187 *		is set appropriately.
 188 *
 189 * BPF_MAP_UPDATE_ELEM
 190 *	Description
 191 *		Create or update an element (key/value pair) in a specified map.
 192 *
 193 *		The *flags* argument should be specified as one of the
 194 *		following:
 195 *
 196 *		**BPF_ANY**
 197 *			Create a new element or update an existing element.
 198 *		**BPF_NOEXIST**
 199 *			Create a new element only if it did not exist.
 200 *		**BPF_EXIST**
 201 *			Update an existing element.
 202 *		**BPF_F_LOCK**
 203 *			Update a spin_lock-ed map element.
 204 *
 205 *	Return
 206 *		Returns zero on success. On error, -1 is returned and *errno*
 207 *		is set appropriately.
 208 *
 209 *		May set *errno* to **EINVAL**, **EPERM**, **ENOMEM**,
 210 *		**E2BIG**, **EEXIST**, or **ENOENT**.
 211 *
 212 *		**E2BIG**
 213 *			The number of elements in the map reached the
 214 *			*max_entries* limit specified at map creation time.
 215 *		**EEXIST**
 216 *			If *flags* specifies **BPF_NOEXIST** and the element
 217 *			with *key* already exists in the map.
 218 *		**ENOENT**
 219 *			If *flags* specifies **BPF_EXIST** and the element with
 220 *			*key* does not exist in the map.
 221 *
 222 * BPF_MAP_DELETE_ELEM
 223 *	Description
 224 *		Look up and delete an element by key in a specified map.
 225 *
 226 *	Return
 227 *		Returns zero on success. On error, -1 is returned and *errno*
 228 *		is set appropriately.
 229 *
 230 * BPF_MAP_GET_NEXT_KEY
 231 *	Description
 232 *		Look up an element by key in a specified map and return the key
 233 *		of the next element. Can be used to iterate over all elements
 234 *		in the map.
 235 *
 236 *	Return
 237 *		Returns zero on success. On error, -1 is returned and *errno*
 238 *		is set appropriately.
 239 *
 240 *		The following cases can be used to iterate over all elements of
 241 *		the map:
 242 *
 243 *		* If *key* is not found, the operation returns zero and sets
 244 *		  the *next_key* pointer to the key of the first element.
 245 *		* If *key* is found, the operation returns zero and sets the
 246 *		  *next_key* pointer to the key of the next element.
 247 *		* If *key* is the last element, returns -1 and *errno* is set
 248 *		  to **ENOENT**.
 249 *
 250 *		May set *errno* to **ENOMEM**, **EFAULT**, **EPERM**, or
 251 *		**EINVAL** on error.
 252 *
 253 * BPF_PROG_LOAD
 254 *	Description
 255 *		Verify and load an eBPF program, returning a new file
 256 *		descriptor associated with the program.
 257 *
 258 *		Applying **close**\ (2) to the file descriptor returned by
 259 *		**BPF_PROG_LOAD** will unload the eBPF program (but see NOTES).
 260 *
 261 *		The close-on-exec file descriptor flag (see **fcntl**\ (2)) is
 262 *		automatically enabled for the new file descriptor.
 263 *
 264 *	Return
 265 *		A new file descriptor (a nonnegative integer), or -1 if an
 266 *		error occurred (in which case, *errno* is set appropriately).
 267 *
 268 * BPF_OBJ_PIN
 269 *	Description
 270 *		Pin an eBPF program or map referred by the specified *bpf_fd*
 271 *		to the provided *pathname* on the filesystem.
 272 *
 273 *		The *pathname* argument must not contain a dot (".").
 274 *
 275 *		On success, *pathname* retains a reference to the eBPF object,
 276 *		preventing deallocation of the object when the original
 277 *		*bpf_fd* is closed. This allow the eBPF object to live beyond
 278 *		**close**\ (\ *bpf_fd*\ ), and hence the lifetime of the parent
 279 *		process.
 280 *
 281 *		Applying **unlink**\ (2) or similar calls to the *pathname*
 282 *		unpins the object from the filesystem, removing the reference.
 283 *		If no other file descriptors or filesystem nodes refer to the
 284 *		same object, it will be deallocated (see NOTES).
 285 *
 286 *		The filesystem type for the parent directory of *pathname* must
 287 *		be **BPF_FS_MAGIC**.
 288 *
 289 *	Return
 290 *		Returns zero on success. On error, -1 is returned and *errno*
 291 *		is set appropriately.
 292 *
 293 * BPF_OBJ_GET
 294 *	Description
 295 *		Open a file descriptor for the eBPF object pinned to the
 296 *		specified *pathname*.
 297 *
 298 *	Return
 299 *		A new file descriptor (a nonnegative integer), or -1 if an
 300 *		error occurred (in which case, *errno* is set appropriately).
 301 *
 302 * BPF_PROG_ATTACH
 303 *	Description
 304 *		Attach an eBPF program to a *target_fd* at the specified
 305 *		*attach_type* hook.
 306 *
 307 *		The *attach_type* specifies the eBPF attachment point to
 308 *		attach the program to, and must be one of *bpf_attach_type*
 309 *		(see below).
 310 *
 311 *		The *attach_bpf_fd* must be a valid file descriptor for a
 312 *		loaded eBPF program of a cgroup, flow dissector, LIRC, sockmap
 313 *		or sock_ops type corresponding to the specified *attach_type*.
 314 *
 315 *		The *target_fd* must be a valid file descriptor for a kernel
 316 *		object which depends on the attach type of *attach_bpf_fd*:
 317 *
 318 *		**BPF_PROG_TYPE_CGROUP_DEVICE**,
 319 *		**BPF_PROG_TYPE_CGROUP_SKB**,
 320 *		**BPF_PROG_TYPE_CGROUP_SOCK**,
 321 *		**BPF_PROG_TYPE_CGROUP_SOCK_ADDR**,
 322 *		**BPF_PROG_TYPE_CGROUP_SOCKOPT**,
 323 *		**BPF_PROG_TYPE_CGROUP_SYSCTL**,
 324 *		**BPF_PROG_TYPE_SOCK_OPS**
 325 *
 326 *			Control Group v2 hierarchy with the eBPF controller
 327 *			enabled. Requires the kernel to be compiled with
 328 *			**CONFIG_CGROUP_BPF**.
 329 *
 330 *		**BPF_PROG_TYPE_FLOW_DISSECTOR**
 331 *
 332 *			Network namespace (eg /proc/self/ns/net).
 333 *
 334 *		**BPF_PROG_TYPE_LIRC_MODE2**
 335 *
 336 *			LIRC device path (eg /dev/lircN). Requires the kernel
 337 *			to be compiled with **CONFIG_BPF_LIRC_MODE2**.
 338 *
 339 *		**BPF_PROG_TYPE_SK_SKB**,
 340 *		**BPF_PROG_TYPE_SK_MSG**
 341 *
 342 *			eBPF map of socket type (eg **BPF_MAP_TYPE_SOCKHASH**).
 343 *
 344 *	Return
 345 *		Returns zero on success. On error, -1 is returned and *errno*
 346 *		is set appropriately.
 347 *
 348 * BPF_PROG_DETACH
 349 *	Description
 350 *		Detach the eBPF program associated with the *target_fd* at the
 351 *		hook specified by *attach_type*. The program must have been
 352 *		previously attached using **BPF_PROG_ATTACH**.
 353 *
 354 *	Return
 355 *		Returns zero on success. On error, -1 is returned and *errno*
 356 *		is set appropriately.
 357 *
 358 * BPF_PROG_TEST_RUN
 359 *	Description
 360 *		Run the eBPF program associated with the *prog_fd* a *repeat*
 361 *		number of times against a provided program context *ctx_in* and
 362 *		data *data_in*, and return the modified program context
 363 *		*ctx_out*, *data_out* (for example, packet data), result of the
 364 *		execution *retval*, and *duration* of the test run.
 365 *
 366 *		The sizes of the buffers provided as input and output
 367 *		parameters *ctx_in*, *ctx_out*, *data_in*, and *data_out* must
 368 *		be provided in the corresponding variables *ctx_size_in*,
 369 *		*ctx_size_out*, *data_size_in*, and/or *data_size_out*. If any
 370 *		of these parameters are not provided (ie set to NULL), the
 371 *		corresponding size field must be zero.
 372 *
 373 *		Some program types have particular requirements:
 374 *
 375 *		**BPF_PROG_TYPE_SK_LOOKUP**
 376 *			*data_in* and *data_out* must be NULL.
 377 *
 378 *		**BPF_PROG_TYPE_RAW_TRACEPOINT**,
 379 *		**BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE**
 380 *
 381 *			*ctx_out*, *data_in* and *data_out* must be NULL.
 382 *			*repeat* must be zero.
 383 *
 384 *		BPF_PROG_RUN is an alias for BPF_PROG_TEST_RUN.
 385 *
 386 *	Return
 387 *		Returns zero on success. On error, -1 is returned and *errno*
 388 *		is set appropriately.
 389 *
 390 *		**ENOSPC**
 391 *			Either *data_size_out* or *ctx_size_out* is too small.
 392 *		**ENOTSUPP**
 393 *			This command is not supported by the program type of
 394 *			the program referred to by *prog_fd*.
 395 *
 396 * BPF_PROG_GET_NEXT_ID
 397 *	Description
 398 *		Fetch the next eBPF program currently loaded into the kernel.
 399 *
 400 *		Looks for the eBPF program with an id greater than *start_id*
 401 *		and updates *next_id* on success. If no other eBPF programs
 402 *		remain with ids higher than *start_id*, returns -1 and sets
 403 *		*errno* to **ENOENT**.
 404 *
 405 *	Return
 406 *		Returns zero on success. On error, or when no id remains, -1
 407 *		is returned and *errno* is set appropriately.
 408 *
 409 * BPF_MAP_GET_NEXT_ID
 410 *	Description
 411 *		Fetch the next eBPF map currently loaded into the kernel.
 412 *
 413 *		Looks for the eBPF map with an id greater than *start_id*
 414 *		and updates *next_id* on success. If no other eBPF maps
 415 *		remain with ids higher than *start_id*, returns -1 and sets
 416 *		*errno* to **ENOENT**.
 417 *
 418 *	Return
 419 *		Returns zero on success. On error, or when no id remains, -1
 420 *		is returned and *errno* is set appropriately.
 421 *
 422 * BPF_PROG_GET_FD_BY_ID
 423 *	Description
 424 *		Open a file descriptor for the eBPF program corresponding to
 425 *		*prog_id*.
 426 *
 427 *	Return
 428 *		A new file descriptor (a nonnegative integer), or -1 if an
 429 *		error occurred (in which case, *errno* is set appropriately).
 430 *
 431 * BPF_MAP_GET_FD_BY_ID
 432 *	Description
 433 *		Open a file descriptor for the eBPF map corresponding to
 434 *		*map_id*.
 435 *
 436 *	Return
 437 *		A new file descriptor (a nonnegative integer), or -1 if an
 438 *		error occurred (in which case, *errno* is set appropriately).
 439 *
 440 * BPF_OBJ_GET_INFO_BY_FD
 441 *	Description
 442 *		Obtain information about the eBPF object corresponding to
 443 *		*bpf_fd*.
 444 *
 445 *		Populates up to *info_len* bytes of *info*, which will be in
 446 *		one of the following formats depending on the eBPF object type
 447 *		of *bpf_fd*:
 448 *
 449 *		* **struct bpf_prog_info**
 450 *		* **struct bpf_map_info**
 451 *		* **struct bpf_btf_info**
 452 *		* **struct bpf_link_info**
 453 *		* **struct bpf_token_info**
 454 *
 455 *	Return
 456 *		Returns zero on success. On error, -1 is returned and *errno*
 457 *		is set appropriately.
 458 *
 459 * BPF_PROG_QUERY
 460 *	Description
 461 *		Obtain information about eBPF programs associated with the
 462 *		specified *attach_type* hook.
 463 *
 464 *		The *target_fd* must be a valid file descriptor for a kernel
 465 *		object which depends on the attach type of *attach_bpf_fd*:
 466 *
 467 *		**BPF_PROG_TYPE_CGROUP_DEVICE**,
 468 *		**BPF_PROG_TYPE_CGROUP_SKB**,
 469 *		**BPF_PROG_TYPE_CGROUP_SOCK**,
 470 *		**BPF_PROG_TYPE_CGROUP_SOCK_ADDR**,
 471 *		**BPF_PROG_TYPE_CGROUP_SOCKOPT**,
 472 *		**BPF_PROG_TYPE_CGROUP_SYSCTL**,
 473 *		**BPF_PROG_TYPE_SOCK_OPS**
 474 *
 475 *			Control Group v2 hierarchy with the eBPF controller
 476 *			enabled. Requires the kernel to be compiled with
 477 *			**CONFIG_CGROUP_BPF**.
 478 *
 479 *		**BPF_PROG_TYPE_FLOW_DISSECTOR**
 480 *
 481 *			Network namespace (eg /proc/self/ns/net).
 482 *
 483 *		**BPF_PROG_TYPE_LIRC_MODE2**
 484 *
 485 *			LIRC device path (eg /dev/lircN). Requires the kernel
 486 *			to be compiled with **CONFIG_BPF_LIRC_MODE2**.
 487 *
 488 *		**BPF_PROG_QUERY** always fetches the number of programs
 489 *		attached and the *attach_flags* which were used to attach those
 490 *		programs. Additionally, if *prog_ids* is nonzero and the number
 491 *		of attached programs is less than *prog_cnt*, populates
 492 *		*prog_ids* with the eBPF program ids of the programs attached
 493 *		at *target_fd*.
 494 *
 495 *		The following flags may alter the result:
 496 *
 497 *		**BPF_F_QUERY_EFFECTIVE**
 498 *			Only return information regarding programs which are
 499 *			currently effective at the specified *target_fd*.
 500 *
 501 *	Return
 502 *		Returns zero on success. On error, -1 is returned and *errno*
 503 *		is set appropriately.
 504 *
 505 * BPF_RAW_TRACEPOINT_OPEN
 506 *	Description
 507 *		Attach an eBPF program to a tracepoint *name* to access kernel
 508 *		internal arguments of the tracepoint in their raw form.
 509 *
 510 *		The *prog_fd* must be a valid file descriptor associated with
 511 *		a loaded eBPF program of type **BPF_PROG_TYPE_RAW_TRACEPOINT**.
 512 *
 513 *		No ABI guarantees are made about the content of tracepoint
 514 *		arguments exposed to the corresponding eBPF program.
 515 *
 516 *		Applying **close**\ (2) to the file descriptor returned by
 517 *		**BPF_RAW_TRACEPOINT_OPEN** will delete the map (but see NOTES).
 518 *
 519 *	Return
 520 *		A new file descriptor (a nonnegative integer), or -1 if an
 521 *		error occurred (in which case, *errno* is set appropriately).
 522 *
 523 * BPF_BTF_LOAD
 524 *	Description
 525 *		Verify and load BPF Type Format (BTF) metadata into the kernel,
 526 *		returning a new file descriptor associated with the metadata.
 527 *		BTF is described in more detail at
 528 *		https://www.kernel.org/doc/html/latest/bpf/btf.html.
 529 *
 530 *		The *btf* parameter must point to valid memory providing
 531 *		*btf_size* bytes of BTF binary metadata.
 532 *
 533 *		The returned file descriptor can be passed to other **bpf**\ ()
 534 *		subcommands such as **BPF_PROG_LOAD** or **BPF_MAP_CREATE** to
 535 *		associate the BTF with those objects.
 536 *
 537 *		Similar to **BPF_PROG_LOAD**, **BPF_BTF_LOAD** has optional
 538 *		parameters to specify a *btf_log_buf*, *btf_log_size* and
 539 *		*btf_log_level* which allow the kernel to return freeform log
 540 *		output regarding the BTF verification process.
 541 *
 542 *	Return
 543 *		A new file descriptor (a nonnegative integer), or -1 if an
 544 *		error occurred (in which case, *errno* is set appropriately).
 545 *
 546 * BPF_BTF_GET_FD_BY_ID
 547 *	Description
 548 *		Open a file descriptor for the BPF Type Format (BTF)
 549 *		corresponding to *btf_id*.
 550 *
 551 *	Return
 552 *		A new file descriptor (a nonnegative integer), or -1 if an
 553 *		error occurred (in which case, *errno* is set appropriately).
 554 *
 555 * BPF_TASK_FD_QUERY
 556 *	Description
 557 *		Obtain information about eBPF programs associated with the
 558 *		target process identified by *pid* and *fd*.
 559 *
 560 *		If the *pid* and *fd* are associated with a tracepoint, kprobe
 561 *		or uprobe perf event, then the *prog_id* and *fd_type* will
 562 *		be populated with the eBPF program id and file descriptor type
 563 *		of type **bpf_task_fd_type**. If associated with a kprobe or
 564 *		uprobe, the  *probe_offset* and *probe_addr* will also be
 565 *		populated. Optionally, if *buf* is provided, then up to
 566 *		*buf_len* bytes of *buf* will be populated with the name of
 567 *		the tracepoint, kprobe or uprobe.
 568 *
 569 *		The resulting *prog_id* may be introspected in deeper detail
 570 *		using **BPF_PROG_GET_FD_BY_ID** and **BPF_OBJ_GET_INFO_BY_FD**.
 571 *
 572 *	Return
 573 *		Returns zero on success. On error, -1 is returned and *errno*
 574 *		is set appropriately.
 575 *
 576 * BPF_MAP_LOOKUP_AND_DELETE_ELEM
 577 *	Description
 578 *		Look up an element with the given *key* in the map referred to
 579 *		by the file descriptor *fd*, and if found, delete the element.
 580 *
 581 *		For **BPF_MAP_TYPE_QUEUE** and **BPF_MAP_TYPE_STACK** map
 582 *		types, the *flags* argument needs to be set to 0, but for other
 583 *		map types, it may be specified as:
 584 *
 585 *		**BPF_F_LOCK**
 586 *			Look up and delete the value of a spin-locked map
 587 *			without returning the lock. This must be specified if
 588 *			the elements contain a spinlock.
 589 *
 590 *		The **BPF_MAP_TYPE_QUEUE** and **BPF_MAP_TYPE_STACK** map types
 591 *		implement this command as a "pop" operation, deleting the top
 592 *		element rather than one corresponding to *key*.
 593 *		The *key* and *key_len* parameters should be zeroed when
 594 *		issuing this operation for these map types.
 595 *
 596 *		This command is only valid for the following map types:
 597 *		* **BPF_MAP_TYPE_QUEUE**
 598 *		* **BPF_MAP_TYPE_STACK**
 599 *		* **BPF_MAP_TYPE_HASH**
 600 *		* **BPF_MAP_TYPE_PERCPU_HASH**
 601 *		* **BPF_MAP_TYPE_LRU_HASH**
 602 *		* **BPF_MAP_TYPE_LRU_PERCPU_HASH**
 603 *
 604 *	Return
 605 *		Returns zero on success. On error, -1 is returned and *errno*
 606 *		is set appropriately.
 607 *
 608 * BPF_MAP_FREEZE
 609 *	Description
 610 *		Freeze the permissions of the specified map.
 611 *
 612 *		Write permissions may be frozen by passing zero *flags*.
 613 *		Upon success, no future syscall invocations may alter the
 614 *		map state of *map_fd*. Write operations from eBPF programs
 615 *		are still possible for a frozen map.
 616 *
 617 *		Not supported for maps of type **BPF_MAP_TYPE_STRUCT_OPS**.
 618 *
 619 *	Return
 620 *		Returns zero on success. On error, -1 is returned and *errno*
 621 *		is set appropriately.
 622 *
 623 * BPF_BTF_GET_NEXT_ID
 624 *	Description
 625 *		Fetch the next BPF Type Format (BTF) object currently loaded
 626 *		into the kernel.
 627 *
 628 *		Looks for the BTF object with an id greater than *start_id*
 629 *		and updates *next_id* on success. If no other BTF objects
 630 *		remain with ids higher than *start_id*, returns -1 and sets
 631 *		*errno* to **ENOENT**.
 632 *
 633 *	Return
 634 *		Returns zero on success. On error, or when no id remains, -1
 635 *		is returned and *errno* is set appropriately.
 636 *
 637 * BPF_MAP_LOOKUP_BATCH
 638 *	Description
 639 *		Iterate and fetch multiple elements in a map.
 640 *
 641 *		Two opaque values are used to manage batch operations,
 642 *		*in_batch* and *out_batch*. Initially, *in_batch* must be set
 643 *		to NULL to begin the batched operation. After each subsequent
 644 *		**BPF_MAP_LOOKUP_BATCH**, the caller should pass the resultant
 645 *		*out_batch* as the *in_batch* for the next operation to
 646 *		continue iteration from the current point. Both *in_batch* and
 647 *		*out_batch* must point to memory large enough to hold a key,
 648 *		except for maps of type **BPF_MAP_TYPE_{HASH, PERCPU_HASH,
 649 *		LRU_HASH, LRU_PERCPU_HASH}**, for which batch parameters
 650 *		must be at least 4 bytes wide regardless of key size.
 651 *
 652 *		The *keys* and *values* are output parameters which must point
 653 *		to memory large enough to hold *count* items based on the key
 654 *		and value size of the map *map_fd*. The *keys* buffer must be
 655 *		of *key_size* * *count*. The *values* buffer must be of
 656 *		*value_size* * *count*.
 657 *
 658 *		The *elem_flags* argument may be specified as one of the
 659 *		following:
 660 *
 661 *		**BPF_F_LOCK**
 662 *			Look up the value of a spin-locked map without
 663 *			returning the lock. This must be specified if the
 664 *			elements contain a spinlock.
 665 *
 666 *		On success, *count* elements from the map are copied into the
 667 *		user buffer, with the keys copied into *keys* and the values
 668 *		copied into the corresponding indices in *values*.
 669 *
 670 *		If an error is returned and *errno* is not **EFAULT**, *count*
 671 *		is set to the number of successfully processed elements.
 672 *
 673 *	Return
 674 *		Returns zero on success. On error, -1 is returned and *errno*
 675 *		is set appropriately.
 676 *
 677 *		May set *errno* to **ENOSPC** to indicate that *keys* or
 678 *		*values* is too small to dump an entire bucket during
 679 *		iteration of a hash-based map type.
 680 *
 681 * BPF_MAP_LOOKUP_AND_DELETE_BATCH
 682 *	Description
 683 *		Iterate and delete all elements in a map.
 684 *
 685 *		This operation has the same behavior as
 686 *		**BPF_MAP_LOOKUP_BATCH** with two exceptions:
 687 *
 688 *		* Every element that is successfully returned is also deleted
 689 *		  from the map. This is at least *count* elements. Note that
 690 *		  *count* is both an input and an output parameter.
 691 *		* Upon returning with *errno* set to **EFAULT**, up to
 692 *		  *count* elements may be deleted without returning the keys
 693 *		  and values of the deleted elements.
 694 *
 695 *	Return
 696 *		Returns zero on success. On error, -1 is returned and *errno*
 697 *		is set appropriately.
 698 *
 699 * BPF_MAP_UPDATE_BATCH
 700 *	Description
 701 *		Update multiple elements in a map by *key*.
 702 *
 703 *		The *keys* and *values* are input parameters which must point
 704 *		to memory large enough to hold *count* items based on the key
 705 *		and value size of the map *map_fd*. The *keys* buffer must be
 706 *		of *key_size* * *count*. The *values* buffer must be of
 707 *		*value_size* * *count*.
 708 *
 709 *		Each element specified in *keys* is sequentially updated to the
 710 *		value in the corresponding index in *values*. The *in_batch*
 711 *		and *out_batch* parameters are ignored and should be zeroed.
 712 *
 713 *		The *elem_flags* argument should be specified as one of the
 714 *		following:
 715 *
 716 *		**BPF_ANY**
 717 *			Create new elements or update a existing elements.
 718 *		**BPF_NOEXIST**
 719 *			Create new elements only if they do not exist.
 720 *		**BPF_EXIST**
 721 *			Update existing elements.
 722 *		**BPF_F_LOCK**
 723 *			Update spin_lock-ed map elements. This must be
 724 *			specified if the map value contains a spinlock.
 725 *
 726 *		On success, *count* elements from the map are updated.
 727 *
 728 *		If an error is returned and *errno* is not **EFAULT**, *count*
 729 *		is set to the number of successfully processed elements.
 730 *
 731 *	Return
 732 *		Returns zero on success. On error, -1 is returned and *errno*
 733 *		is set appropriately.
 734 *
 735 *		May set *errno* to **EINVAL**, **EPERM**, **ENOMEM**, or
 736 *		**E2BIG**. **E2BIG** indicates that the number of elements in
 737 *		the map reached the *max_entries* limit specified at map
 738 *		creation time.
 739 *
 740 *		May set *errno* to one of the following error codes under
 741 *		specific circumstances:
 742 *
 743 *		**EEXIST**
 744 *			If *flags* specifies **BPF_NOEXIST** and the element
 745 *			with *key* already exists in the map.
 746 *		**ENOENT**
 747 *			If *flags* specifies **BPF_EXIST** and the element with
 748 *			*key* does not exist in the map.
 749 *
 750 * BPF_MAP_DELETE_BATCH
 751 *	Description
 752 *		Delete multiple elements in a map by *key*.
 753 *
 754 *		The *keys* parameter is an input parameter which must point
 755 *		to memory large enough to hold *count* items based on the key
 756 *		size of the map *map_fd*, that is, *key_size* * *count*.
 757 *
 758 *		Each element specified in *keys* is sequentially deleted. The
 759 *		*in_batch*, *out_batch*, and *values* parameters are ignored
 760 *		and should be zeroed.
 761 *
 762 *		The *elem_flags* argument may be specified as one of the
 763 *		following:
 764 *
 765 *		**BPF_F_LOCK**
 766 *			Look up the value of a spin-locked map without
 767 *			returning the lock. This must be specified if the
 768 *			elements contain a spinlock.
 769 *
 770 *		On success, *count* elements from the map are updated.
 771 *
 772 *		If an error is returned and *errno* is not **EFAULT**, *count*
 773 *		is set to the number of successfully processed elements. If
 774 *		*errno* is **EFAULT**, up to *count* elements may be been
 775 *		deleted.
 776 *
 777 *	Return
 778 *		Returns zero on success. On error, -1 is returned and *errno*
 779 *		is set appropriately.
 780 *
 781 * BPF_LINK_CREATE
 782 *	Description
 783 *		Attach an eBPF program to a *target_fd* at the specified
 784 *		*attach_type* hook and return a file descriptor handle for
 785 *		managing the link.
 786 *
 787 *	Return
 788 *		A new file descriptor (a nonnegative integer), or -1 if an
 789 *		error occurred (in which case, *errno* is set appropriately).
 790 *
 791 * BPF_LINK_UPDATE
 792 *	Description
 793 *		Update the eBPF program in the specified *link_fd* to
 794 *		*new_prog_fd*.
 795 *
 796 *	Return
 797 *		Returns zero on success. On error, -1 is returned and *errno*
 798 *		is set appropriately.
 799 *
 800 * BPF_LINK_GET_FD_BY_ID
 801 *	Description
 802 *		Open a file descriptor for the eBPF Link corresponding to
 803 *		*link_id*.
 804 *
 805 *	Return
 806 *		A new file descriptor (a nonnegative integer), or -1 if an
 807 *		error occurred (in which case, *errno* is set appropriately).
 808 *
 809 * BPF_LINK_GET_NEXT_ID
 810 *	Description
 811 *		Fetch the next eBPF link currently loaded into the kernel.
 812 *
 813 *		Looks for the eBPF link with an id greater than *start_id*
 814 *		and updates *next_id* on success. If no other eBPF links
 815 *		remain with ids higher than *start_id*, returns -1 and sets
 816 *		*errno* to **ENOENT**.
 817 *
 818 *	Return
 819 *		Returns zero on success. On error, or when no id remains, -1
 820 *		is returned and *errno* is set appropriately.
 821 *
 822 * BPF_ENABLE_STATS
 823 *	Description
 824 *		Enable eBPF runtime statistics gathering.
 825 *
 826 *		Runtime statistics gathering for the eBPF runtime is disabled
 827 *		by default to minimize the corresponding performance overhead.
 828 *		This command enables statistics globally.
 829 *
 830 *		Multiple programs may independently enable statistics.
 831 *		After gathering the desired statistics, eBPF runtime statistics
 832 *		may be disabled again by calling **close**\ (2) for the file
 833 *		descriptor returned by this function. Statistics will only be
 834 *		disabled system-wide when all outstanding file descriptors
 835 *		returned by prior calls for this subcommand are closed.
 836 *
 837 *	Return
 838 *		A new file descriptor (a nonnegative integer), or -1 if an
 839 *		error occurred (in which case, *errno* is set appropriately).
 840 *
 841 * BPF_ITER_CREATE
 842 *	Description
 843 *		Create an iterator on top of the specified *link_fd* (as
 844 *		previously created using **BPF_LINK_CREATE**) and return a
 845 *		file descriptor that can be used to trigger the iteration.
 846 *
 847 *		If the resulting file descriptor is pinned to the filesystem
 848 *		using  **BPF_OBJ_PIN**, then subsequent **read**\ (2) syscalls
 849 *		for that path will trigger the iterator to read kernel state
 850 *		using the eBPF program attached to *link_fd*.
 851 *
 852 *	Return
 853 *		A new file descriptor (a nonnegative integer), or -1 if an
 854 *		error occurred (in which case, *errno* is set appropriately).
 855 *
 856 * BPF_LINK_DETACH
 857 *	Description
 858 *		Forcefully detach the specified *link_fd* from its
 859 *		corresponding attachment point.
 860 *
 861 *	Return
 862 *		Returns zero on success. On error, -1 is returned and *errno*
 863 *		is set appropriately.
 864 *
 865 * BPF_PROG_BIND_MAP
 866 *	Description
 867 *		Bind a map to the lifetime of an eBPF program.
 868 *
 869 *		The map identified by *map_fd* is bound to the program
 870 *		identified by *prog_fd* and only released when *prog_fd* is
 871 *		released. This may be used in cases where metadata should be
 872 *		associated with a program which otherwise does not contain any
 873 *		references to the map (for example, embedded in the eBPF
 874 *		program instructions).
 875 *
 876 *	Return
 877 *		Returns zero on success. On error, -1 is returned and *errno*
 878 *		is set appropriately.
 879 *
 880 * BPF_TOKEN_CREATE
 881 *	Description
 882 *		Create BPF token with embedded information about what
 883 *		BPF-related functionality it allows:
 884 *		- a set of allowed bpf() syscall commands;
 885 *		- a set of allowed BPF map types to be created with
 886 *		BPF_MAP_CREATE command, if BPF_MAP_CREATE itself is allowed;
 887 *		- a set of allowed BPF program types and BPF program attach
 888 *		types to be loaded with BPF_PROG_LOAD command, if
 889 *		BPF_PROG_LOAD itself is allowed.
 890 *
 891 *		BPF token is created (derived) from an instance of BPF FS,
 892 *		assuming it has necessary delegation mount options specified.
 893 *		This BPF token can be passed as an extra parameter to various
 894 *		bpf() syscall commands to grant BPF subsystem functionality to
 895 *		unprivileged processes.
 896 *
 897 *		When created, BPF token is "associated" with the owning
 898 *		user namespace of BPF FS instance (super block) that it was
 899 *		derived from, and subsequent BPF operations performed with
 900 *		BPF token would be performing capabilities checks (i.e.,
 901 *		CAP_BPF, CAP_PERFMON, CAP_NET_ADMIN, CAP_SYS_ADMIN) within
 902 *		that user namespace. Without BPF token, such capabilities
 903 *		have to be granted in init user namespace, making bpf()
 904 *		syscall incompatible with user namespace, for the most part.
 905 *
 906 *	Return
 907 *		A new file descriptor (a nonnegative integer), or -1 if an
 908 *		error occurred (in which case, *errno* is set appropriately).
 909 *
 910 * BPF_PROG_STREAM_READ_BY_FD
 911 *	Description
 912 *		Read data of a program's BPF stream. The program is identified
 913 *		by *prog_fd*, and the stream is identified by the *stream_id*.
 914 *		The data is copied to a buffer pointed to by *stream_buf*, and
 915 *		filled less than or equal to *stream_buf_len* bytes.
 916 *
 917 *	Return
 918 *		Number of bytes read from the stream on success, or -1 if an
 919 *		error occurred (in which case, *errno* is set appropriately).
 920 *
 921 * NOTES
 922 *	eBPF objects (maps and programs) can be shared between processes.
 923 *
 924 *	* After **fork**\ (2), the child inherits file descriptors
 925 *	  referring to the same eBPF objects.
 926 *	* File descriptors referring to eBPF objects can be transferred over
 927 *	  **unix**\ (7) domain sockets.
 928 *	* File descriptors referring to eBPF objects can be duplicated in the
 929 *	  usual way, using **dup**\ (2) and similar calls.
 930 *	* File descriptors referring to eBPF objects can be pinned to the
 931 *	  filesystem using the **BPF_OBJ_PIN** command of **bpf**\ (2).
 932 *
 933 *	An eBPF object is deallocated only after all file descriptors referring
 934 *	to the object have been closed and no references remain pinned to the
 935 *	filesystem or attached (for example, bound to a program or device).
 936 */
 937enum bpf_cmd {
 938	BPF_MAP_CREATE,
 939	BPF_MAP_LOOKUP_ELEM,
 940	BPF_MAP_UPDATE_ELEM,
 941	BPF_MAP_DELETE_ELEM,
 942	BPF_MAP_GET_NEXT_KEY,
 943	BPF_PROG_LOAD,
 944	BPF_OBJ_PIN,
 945	BPF_OBJ_GET,
 946	BPF_PROG_ATTACH,
 947	BPF_PROG_DETACH,
 948	BPF_PROG_TEST_RUN,
 949	BPF_PROG_RUN = BPF_PROG_TEST_RUN,
 950	BPF_PROG_GET_NEXT_ID,
 951	BPF_MAP_GET_NEXT_ID,
 952	BPF_PROG_GET_FD_BY_ID,
 953	BPF_MAP_GET_FD_BY_ID,
 954	BPF_OBJ_GET_INFO_BY_FD,
 955	BPF_PROG_QUERY,
 956	BPF_RAW_TRACEPOINT_OPEN,
 957	BPF_BTF_LOAD,
 958	BPF_BTF_GET_FD_BY_ID,
 959	BPF_TASK_FD_QUERY,
 960	BPF_MAP_LOOKUP_AND_DELETE_ELEM,
 961	BPF_MAP_FREEZE,
 962	BPF_BTF_GET_NEXT_ID,
 963	BPF_MAP_LOOKUP_BATCH,
 964	BPF_MAP_LOOKUP_AND_DELETE_BATCH,
 965	BPF_MAP_UPDATE_BATCH,
 966	BPF_MAP_DELETE_BATCH,
 967	BPF_LINK_CREATE,
 968	BPF_LINK_UPDATE,
 969	BPF_LINK_GET_FD_BY_ID,
 970	BPF_LINK_GET_NEXT_ID,
 971	BPF_ENABLE_STATS,
 972	BPF_ITER_CREATE,
 973	BPF_LINK_DETACH,
 974	BPF_PROG_BIND_MAP,
 975	BPF_TOKEN_CREATE,
 976	BPF_PROG_STREAM_READ_BY_FD,
 977	__MAX_BPF_CMD,
 978};
 979
 980enum bpf_map_type {
 981	BPF_MAP_TYPE_UNSPEC,
 982	BPF_MAP_TYPE_HASH,
 983	BPF_MAP_TYPE_ARRAY,
 984	BPF_MAP_TYPE_PROG_ARRAY,
 985	BPF_MAP_TYPE_PERF_EVENT_ARRAY,
 986	BPF_MAP_TYPE_PERCPU_HASH,
 987	BPF_MAP_TYPE_PERCPU_ARRAY,
 988	BPF_MAP_TYPE_STACK_TRACE,
 989	BPF_MAP_TYPE_CGROUP_ARRAY,
 990	BPF_MAP_TYPE_LRU_HASH,
 991	BPF_MAP_TYPE_LRU_PERCPU_HASH,
 992	BPF_MAP_TYPE_LPM_TRIE,
 993	BPF_MAP_TYPE_ARRAY_OF_MAPS,
 994	BPF_MAP_TYPE_HASH_OF_MAPS,
 995	BPF_MAP_TYPE_DEVMAP,
 996	BPF_MAP_TYPE_SOCKMAP,
 997	BPF_MAP_TYPE_CPUMAP,
 998	BPF_MAP_TYPE_XSKMAP,
 999	BPF_MAP_TYPE_SOCKHASH,
1000	BPF_MAP_TYPE_CGROUP_STORAGE_DEPRECATED,
1001	/* BPF_MAP_TYPE_CGROUP_STORAGE is available to bpf programs attaching
1002	 * to a cgroup. The newer BPF_MAP_TYPE_CGRP_STORAGE is available to
1003	 * both cgroup-attached and other progs and supports all functionality
1004	 * provided by BPF_MAP_TYPE_CGROUP_STORAGE. So mark
1005	 * BPF_MAP_TYPE_CGROUP_STORAGE deprecated.
1006	 */
1007	BPF_MAP_TYPE_CGROUP_STORAGE = BPF_MAP_TYPE_CGROUP_STORAGE_DEPRECATED,
1008	BPF_MAP_TYPE_REUSEPORT_SOCKARRAY,
1009	BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE_DEPRECATED,
1010	/* BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE is available to bpf programs
1011	 * attaching to a cgroup. The new mechanism (BPF_MAP_TYPE_CGRP_STORAGE +
1012	 * local percpu kptr) supports all BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE
1013	 * functionality and more. So mark * BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE
1014	 * deprecated.
1015	 */
1016	BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE = BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE_DEPRECATED,
1017	BPF_MAP_TYPE_QUEUE,
1018	BPF_MAP_TYPE_STACK,
1019	BPF_MAP_TYPE_SK_STORAGE,
1020	BPF_MAP_TYPE_DEVMAP_HASH,
1021	BPF_MAP_TYPE_STRUCT_OPS,
1022	BPF_MAP_TYPE_RINGBUF,
1023	BPF_MAP_TYPE_INODE_STORAGE,
1024	BPF_MAP_TYPE_TASK_STORAGE,
1025	BPF_MAP_TYPE_BLOOM_FILTER,
1026	BPF_MAP_TYPE_USER_RINGBUF,
1027	BPF_MAP_TYPE_CGRP_STORAGE,
1028	BPF_MAP_TYPE_ARENA,
1029	BPF_MAP_TYPE_INSN_ARRAY,
1030	__MAX_BPF_MAP_TYPE
1031};
1032
1033/* Note that tracing related programs such as
1034 * BPF_PROG_TYPE_{KPROBE,TRACEPOINT,PERF_EVENT,RAW_TRACEPOINT}
1035 * are not subject to a stable API since kernel internal data
1036 * structures can change from release to release and may
1037 * therefore break existing tracing BPF programs. Tracing BPF
1038 * programs correspond to /a/ specific kernel which is to be
1039 * analyzed, and not /a/ specific kernel /and/ all future ones.
1040 */
1041enum bpf_prog_type {
1042	BPF_PROG_TYPE_UNSPEC,
1043	BPF_PROG_TYPE_SOCKET_FILTER,
1044	BPF_PROG_TYPE_KPROBE,
1045	BPF_PROG_TYPE_SCHED_CLS,
1046	BPF_PROG_TYPE_SCHED_ACT,
1047	BPF_PROG_TYPE_TRACEPOINT,
1048	BPF_PROG_TYPE_XDP,
1049	BPF_PROG_TYPE_PERF_EVENT,
1050	BPF_PROG_TYPE_CGROUP_SKB,
1051	BPF_PROG_TYPE_CGROUP_SOCK,
1052	BPF_PROG_TYPE_LWT_IN,
1053	BPF_PROG_TYPE_LWT_OUT,
1054	BPF_PROG_TYPE_LWT_XMIT,
1055	BPF_PROG_TYPE_SOCK_OPS,
1056	BPF_PROG_TYPE_SK_SKB,
1057	BPF_PROG_TYPE_CGROUP_DEVICE,
1058	BPF_PROG_TYPE_SK_MSG,
1059	BPF_PROG_TYPE_RAW_TRACEPOINT,
1060	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
1061	BPF_PROG_TYPE_LWT_SEG6LOCAL,
1062	BPF_PROG_TYPE_LIRC_MODE2,
1063	BPF_PROG_TYPE_SK_REUSEPORT,
1064	BPF_PROG_TYPE_FLOW_DISSECTOR,
1065	BPF_PROG_TYPE_CGROUP_SYSCTL,
1066	BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE,
1067	BPF_PROG_TYPE_CGROUP_SOCKOPT,
1068	BPF_PROG_TYPE_TRACING,
1069	BPF_PROG_TYPE_STRUCT_OPS,
1070	BPF_PROG_TYPE_EXT,
1071	BPF_PROG_TYPE_LSM,
1072	BPF_PROG_TYPE_SK_LOOKUP,
1073	BPF_PROG_TYPE_SYSCALL, /* a program that can execute syscalls */
1074	BPF_PROG_TYPE_NETFILTER,
1075	__MAX_BPF_PROG_TYPE
1076};
1077
1078enum bpf_attach_type {
1079	BPF_CGROUP_INET_INGRESS,
1080	BPF_CGROUP_INET_EGRESS,
1081	BPF_CGROUP_INET_SOCK_CREATE,
1082	BPF_CGROUP_SOCK_OPS,
1083	BPF_SK_SKB_STREAM_PARSER,
1084	BPF_SK_SKB_STREAM_VERDICT,
1085	BPF_CGROUP_DEVICE,
1086	BPF_SK_MSG_VERDICT,
1087	BPF_CGROUP_INET4_BIND,
1088	BPF_CGROUP_INET6_BIND,
1089	BPF_CGROUP_INET4_CONNECT,
1090	BPF_CGROUP_INET6_CONNECT,
1091	BPF_CGROUP_INET4_POST_BIND,
1092	BPF_CGROUP_INET6_POST_BIND,
1093	BPF_CGROUP_UDP4_SENDMSG,
1094	BPF_CGROUP_UDP6_SENDMSG,
1095	BPF_LIRC_MODE2,
1096	BPF_FLOW_DISSECTOR,
1097	BPF_CGROUP_SYSCTL,
1098	BPF_CGROUP_UDP4_RECVMSG,
1099	BPF_CGROUP_UDP6_RECVMSG,
1100	BPF_CGROUP_GETSOCKOPT,
1101	BPF_CGROUP_SETSOCKOPT,
1102	BPF_TRACE_RAW_TP,
1103	BPF_TRACE_FENTRY,
1104	BPF_TRACE_FEXIT,
1105	BPF_MODIFY_RETURN,
1106	BPF_LSM_MAC,
1107	BPF_TRACE_ITER,
1108	BPF_CGROUP_INET4_GETPEERNAME,
1109	BPF_CGROUP_INET6_GETPEERNAME,
1110	BPF_CGROUP_INET4_GETSOCKNAME,
1111	BPF_CGROUP_INET6_GETSOCKNAME,
1112	BPF_XDP_DEVMAP,
1113	BPF_CGROUP_INET_SOCK_RELEASE,
1114	BPF_XDP_CPUMAP,
1115	BPF_SK_LOOKUP,
1116	BPF_XDP,
1117	BPF_SK_SKB_VERDICT,
1118	BPF_SK_REUSEPORT_SELECT,
1119	BPF_SK_REUSEPORT_SELECT_OR_MIGRATE,
1120	BPF_PERF_EVENT,
1121	BPF_TRACE_KPROBE_MULTI,
1122	BPF_LSM_CGROUP,
1123	BPF_STRUCT_OPS,
1124	BPF_NETFILTER,
1125	BPF_TCX_INGRESS,
1126	BPF_TCX_EGRESS,
1127	BPF_TRACE_UPROBE_MULTI,
1128	BPF_CGROUP_UNIX_CONNECT,
1129	BPF_CGROUP_UNIX_SENDMSG,
1130	BPF_CGROUP_UNIX_RECVMSG,
1131	BPF_CGROUP_UNIX_GETPEERNAME,
1132	BPF_CGROUP_UNIX_GETSOCKNAME,
1133	BPF_NETKIT_PRIMARY,
1134	BPF_NETKIT_PEER,
1135	BPF_TRACE_KPROBE_SESSION,
1136	BPF_TRACE_UPROBE_SESSION,
1137	__MAX_BPF_ATTACH_TYPE
1138};
1139
1140#define MAX_BPF_ATTACH_TYPE __MAX_BPF_ATTACH_TYPE
1141
1142/* Add BPF_LINK_TYPE(type, name) in bpf_types.h to keep bpf_link_type_strs[]
1143 * in sync with the definitions below.
1144 */
1145enum bpf_link_type {
1146	BPF_LINK_TYPE_UNSPEC = 0,
1147	BPF_LINK_TYPE_RAW_TRACEPOINT = 1,
1148	BPF_LINK_TYPE_TRACING = 2,
1149	BPF_LINK_TYPE_CGROUP = 3,
1150	BPF_LINK_TYPE_ITER = 4,
1151	BPF_LINK_TYPE_NETNS = 5,
1152	BPF_LINK_TYPE_XDP = 6,
1153	BPF_LINK_TYPE_PERF_EVENT = 7,
1154	BPF_LINK_TYPE_KPROBE_MULTI = 8,
1155	BPF_LINK_TYPE_STRUCT_OPS = 9,
1156	BPF_LINK_TYPE_NETFILTER = 10,
1157	BPF_LINK_TYPE_TCX = 11,
1158	BPF_LINK_TYPE_UPROBE_MULTI = 12,
1159	BPF_LINK_TYPE_NETKIT = 13,
1160	BPF_LINK_TYPE_SOCKMAP = 14,
1161	__MAX_BPF_LINK_TYPE,
1162};
1163
1164#define MAX_BPF_LINK_TYPE __MAX_BPF_LINK_TYPE
1165
1166enum bpf_perf_event_type {
1167	BPF_PERF_EVENT_UNSPEC = 0,
1168	BPF_PERF_EVENT_UPROBE = 1,
1169	BPF_PERF_EVENT_URETPROBE = 2,
1170	BPF_PERF_EVENT_KPROBE = 3,
1171	BPF_PERF_EVENT_KRETPROBE = 4,
1172	BPF_PERF_EVENT_TRACEPOINT = 5,
1173	BPF_PERF_EVENT_EVENT = 6,
1174};
1175
1176/* cgroup-bpf attach flags used in BPF_PROG_ATTACH command
1177 *
1178 * NONE(default): No further bpf programs allowed in the subtree.
1179 *
1180 * BPF_F_ALLOW_OVERRIDE: If a sub-cgroup installs some bpf program,
1181 * the program in this cgroup yields to sub-cgroup program.
1182 *
1183 * BPF_F_ALLOW_MULTI: If a sub-cgroup installs some bpf program,
1184 * that cgroup program gets run in addition to the program in this cgroup.
1185 *
1186 * Only one program is allowed to be attached to a cgroup with
1187 * NONE or BPF_F_ALLOW_OVERRIDE flag.
1188 * Attaching another program on top of NONE or BPF_F_ALLOW_OVERRIDE will
1189 * release old program and attach the new one. Attach flags has to match.
1190 *
1191 * Multiple programs are allowed to be attached to a cgroup with
1192 * BPF_F_ALLOW_MULTI flag. They are executed in FIFO order
1193 * (those that were attached first, run first)
1194 * The programs of sub-cgroup are executed first, then programs of
1195 * this cgroup and then programs of parent cgroup.
1196 * When children program makes decision (like picking TCP CA or sock bind)
1197 * parent program has a chance to override it.
1198 *
1199 * With BPF_F_ALLOW_MULTI a new program is added to the end of the list of
1200 * programs for a cgroup. Though it's possible to replace an old program at
1201 * any position by also specifying BPF_F_REPLACE flag and position itself in
1202 * replace_bpf_fd attribute. Old program at this position will be released.
1203 *
1204 * A cgroup with MULTI or OVERRIDE flag allows any attach flags in sub-cgroups.
1205 * A cgroup with NONE doesn't allow any programs in sub-cgroups.
1206 * Ex1:
1207 * cgrp1 (MULTI progs A, B) ->
1208 *    cgrp2 (OVERRIDE prog C) ->
1209 *      cgrp3 (MULTI prog D) ->
1210 *        cgrp4 (OVERRIDE prog E) ->
1211 *          cgrp5 (NONE prog F)
1212 * the event in cgrp5 triggers execution of F,D,A,B in that order.
1213 * if prog F is detached, the execution is E,D,A,B
1214 * if prog F and D are detached, the execution is E,A,B
1215 * if prog F, E and D are detached, the execution is C,A,B
1216 *
1217 * All eligible programs are executed regardless of return code from
1218 * earlier programs.
1219 */
1220#define BPF_F_ALLOW_OVERRIDE	(1U << 0)
1221#define BPF_F_ALLOW_MULTI	(1U << 1)
1222/* Generic attachment flags. */
1223#define BPF_F_REPLACE		(1U << 2)
1224#define BPF_F_BEFORE		(1U << 3)
1225#define BPF_F_AFTER		(1U << 4)
1226#define BPF_F_ID		(1U << 5)
1227#define BPF_F_PREORDER		(1U << 6)
1228#define BPF_F_LINK		BPF_F_LINK /* 1 << 13 */
1229
1230/* If BPF_F_STRICT_ALIGNMENT is used in BPF_PROG_LOAD command, the
1231 * verifier will perform strict alignment checking as if the kernel
1232 * has been built with CONFIG_EFFICIENT_UNALIGNED_ACCESS not set,
1233 * and NET_IP_ALIGN defined to 2.
1234 */
1235#define BPF_F_STRICT_ALIGNMENT	(1U << 0)
1236
1237/* If BPF_F_ANY_ALIGNMENT is used in BPF_PROG_LOAD command, the
1238 * verifier will allow any alignment whatsoever.  On platforms
1239 * with strict alignment requirements for loads ands stores (such
1240 * as sparc and mips) the verifier validates that all loads and
1241 * stores provably follow this requirement.  This flag turns that
1242 * checking and enforcement off.
1243 *
1244 * It is mostly used for testing when we want to validate the
1245 * context and memory access aspects of the verifier, but because
1246 * of an unaligned access the alignment check would trigger before
1247 * the one we are interested in.
1248 */
1249#define BPF_F_ANY_ALIGNMENT	(1U << 1)
1250
1251/* BPF_F_TEST_RND_HI32 is used in BPF_PROG_LOAD command for testing purpose.
1252 * Verifier does sub-register def/use analysis and identifies instructions whose
1253 * def only matters for low 32-bit, high 32-bit is never referenced later
1254 * through implicit zero extension. Therefore verifier notifies JIT back-ends
1255 * that it is safe to ignore clearing high 32-bit for these instructions. This
1256 * saves some back-ends a lot of code-gen. However such optimization is not
1257 * necessary on some arches, for example x86_64, arm64 etc, whose JIT back-ends
1258 * hence hasn't used verifier's analysis result. But, we really want to have a
1259 * way to be able to verify the correctness of the described optimization on
1260 * x86_64 on which testsuites are frequently exercised.
1261 *
1262 * So, this flag is introduced. Once it is set, verifier will randomize high
1263 * 32-bit for those instructions who has been identified as safe to ignore them.
1264 * Then, if verifier is not doing correct analysis, such randomization will
1265 * regress tests to expose bugs.
1266 */
1267#define BPF_F_TEST_RND_HI32	(1U << 2)
1268
1269/* The verifier internal test flag. Behavior is undefined */
1270#define BPF_F_TEST_STATE_FREQ	(1U << 3)
1271
1272/* If BPF_F_SLEEPABLE is used in BPF_PROG_LOAD command, the verifier will
1273 * restrict map and helper usage for such programs. Sleepable BPF programs can
1274 * only be attached to hooks where kernel execution context allows sleeping.
1275 * Such programs are allowed to use helpers that may sleep like
1276 * bpf_copy_from_user().
1277 */
1278#define BPF_F_SLEEPABLE		(1U << 4)
1279
1280/* If BPF_F_XDP_HAS_FRAGS is used in BPF_PROG_LOAD command, the loaded program
1281 * fully support xdp frags.
1282 */
1283#define BPF_F_XDP_HAS_FRAGS	(1U << 5)
1284
1285/* If BPF_F_XDP_DEV_BOUND_ONLY is used in BPF_PROG_LOAD command, the loaded
1286 * program becomes device-bound but can access XDP metadata.
1287 */
1288#define BPF_F_XDP_DEV_BOUND_ONLY	(1U << 6)
1289
1290/* The verifier internal test flag. Behavior is undefined */
1291#define BPF_F_TEST_REG_INVARIANTS	(1U << 7)
1292
1293/* link_create.kprobe_multi.flags used in LINK_CREATE command for
1294 * BPF_TRACE_KPROBE_MULTI attach type to create return probe.
1295 */
1296enum {
1297	BPF_F_KPROBE_MULTI_RETURN = (1U << 0)
1298};
1299
1300/* link_create.uprobe_multi.flags used in LINK_CREATE command for
1301 * BPF_TRACE_UPROBE_MULTI attach type to create return probe.
1302 */
1303enum {
1304	BPF_F_UPROBE_MULTI_RETURN = (1U << 0)
1305};
1306
1307/* link_create.netfilter.flags used in LINK_CREATE command for
1308 * BPF_PROG_TYPE_NETFILTER to enable IP packet defragmentation.
1309 */
1310#define BPF_F_NETFILTER_IP_DEFRAG (1U << 0)
1311
1312/* When BPF ldimm64's insn[0].src_reg != 0 then this can have
1313 * the following extensions:
1314 *
1315 * insn[0].src_reg:  BPF_PSEUDO_MAP_[FD|IDX]
1316 * insn[0].imm:      map fd or fd_idx
1317 * insn[1].imm:      0
1318 * insn[0].off:      0
1319 * insn[1].off:      0
1320 * ldimm64 rewrite:  address of map
1321 * verifier type:    CONST_PTR_TO_MAP
1322 */
1323#define BPF_PSEUDO_MAP_FD	1
1324#define BPF_PSEUDO_MAP_IDX	5
1325
1326/* insn[0].src_reg:  BPF_PSEUDO_MAP_[IDX_]VALUE
1327 * insn[0].imm:      map fd or fd_idx
1328 * insn[1].imm:      offset into value
1329 * insn[0].off:      0
1330 * insn[1].off:      0
1331 * ldimm64 rewrite:  address of map[0]+offset
1332 * verifier type:    PTR_TO_MAP_VALUE
1333 */
1334#define BPF_PSEUDO_MAP_VALUE		2
1335#define BPF_PSEUDO_MAP_IDX_VALUE	6
1336
1337/* insn[0].src_reg:  BPF_PSEUDO_BTF_ID
1338 * insn[0].imm:      kernel btd id of VAR
1339 * insn[1].imm:      0
1340 * insn[0].off:      0
1341 * insn[1].off:      0
1342 * ldimm64 rewrite:  address of the kernel variable
1343 * verifier type:    PTR_TO_BTF_ID or PTR_TO_MEM, depending on whether the var
1344 *                   is struct/union.
1345 */
1346#define BPF_PSEUDO_BTF_ID	3
1347/* insn[0].src_reg:  BPF_PSEUDO_FUNC
1348 * insn[0].imm:      insn offset to the func
1349 * insn[1].imm:      0
1350 * insn[0].off:      0
1351 * insn[1].off:      0
1352 * ldimm64 rewrite:  address of the function
1353 * verifier type:    PTR_TO_FUNC.
1354 */
1355#define BPF_PSEUDO_FUNC		4
1356
1357/* when bpf_call->src_reg == BPF_PSEUDO_CALL, bpf_call->imm == pc-relative
1358 * offset to another bpf function
1359 */
1360#define BPF_PSEUDO_CALL		1
1361/* when bpf_call->src_reg == BPF_PSEUDO_KFUNC_CALL,
1362 * bpf_call->imm == btf_id of a BTF_KIND_FUNC in the running kernel
1363 */
1364#define BPF_PSEUDO_KFUNC_CALL	2
1365
1366enum bpf_addr_space_cast {
1367	BPF_ADDR_SPACE_CAST = 1,
1368};
1369
1370/* flags for BPF_MAP_UPDATE_ELEM command */
1371enum {
1372	BPF_ANY		= 0, /* create new element or update existing */
1373	BPF_NOEXIST	= 1, /* create new element if it didn't exist */
1374	BPF_EXIST	= 2, /* update existing element */
1375	BPF_F_LOCK	= 4, /* spin_lock-ed map_lookup/map_update */
1376};
1377
1378/* flags for BPF_MAP_CREATE command */
1379enum {
1380	BPF_F_NO_PREALLOC	= (1U << 0),
1381/* Instead of having one common LRU list in the
1382 * BPF_MAP_TYPE_LRU_[PERCPU_]HASH map, use a percpu LRU list
1383 * which can scale and perform better.
1384 * Note, the LRU nodes (including free nodes) cannot be moved
1385 * across different LRU lists.
1386 */
1387	BPF_F_NO_COMMON_LRU	= (1U << 1),
1388/* Specify numa node during map creation */
1389	BPF_F_NUMA_NODE		= (1U << 2),
1390
1391/* Flags for accessing BPF object from syscall side. */
1392	BPF_F_RDONLY		= (1U << 3),
1393	BPF_F_WRONLY		= (1U << 4),
1394
1395/* Flag for stack_map, store build_id+offset instead of pointer */
1396	BPF_F_STACK_BUILD_ID	= (1U << 5),
1397
1398/* Zero-initialize hash function seed. This should only be used for testing. */
1399	BPF_F_ZERO_SEED		= (1U << 6),
1400
1401/* Flags for accessing BPF object from program side. */
1402	BPF_F_RDONLY_PROG	= (1U << 7),
1403	BPF_F_WRONLY_PROG	= (1U << 8),
1404
1405/* Clone map from listener for newly accepted socket */
1406	BPF_F_CLONE		= (1U << 9),
1407
1408/* Enable memory-mapping BPF map */
1409	BPF_F_MMAPABLE		= (1U << 10),
1410
1411/* Share perf_event among processes */
1412	BPF_F_PRESERVE_ELEMS	= (1U << 11),
1413
1414/* Create a map that is suitable to be an inner map with dynamic max entries */
1415	BPF_F_INNER_MAP		= (1U << 12),
1416
1417/* Create a map that will be registered/unregesitered by the backed bpf_link */
1418	BPF_F_LINK		= (1U << 13),
1419
1420/* Get path from provided FD in BPF_OBJ_PIN/BPF_OBJ_GET commands */
1421	BPF_F_PATH_FD		= (1U << 14),
1422
1423/* Flag for value_type_btf_obj_fd, the fd is available */
1424	BPF_F_VTYPE_BTF_OBJ_FD	= (1U << 15),
1425
1426/* BPF token FD is passed in a corresponding command's token_fd field */
1427	BPF_F_TOKEN_FD          = (1U << 16),
1428
1429/* When user space page faults in bpf_arena send SIGSEGV instead of inserting new page */
1430	BPF_F_SEGV_ON_FAULT	= (1U << 17),
1431
1432/* Do not translate kernel bpf_arena pointers to user pointers */
1433	BPF_F_NO_USER_CONV	= (1U << 18),
1434
1435/* Enable BPF ringbuf overwrite mode */
1436	BPF_F_RB_OVERWRITE	= (1U << 19),
1437};
1438
1439/* Flags for BPF_PROG_QUERY. */
1440
1441/* Query effective (directly attached + inherited from ancestor cgroups)
1442 * programs that will be executed for events within a cgroup.
1443 * attach_flags with this flag are always returned 0.
1444 */
1445#define BPF_F_QUERY_EFFECTIVE	(1U << 0)
1446
1447/* Flags for BPF_PROG_TEST_RUN */
1448
1449/* If set, run the test on the cpu specified by bpf_attr.test.cpu */
1450#define BPF_F_TEST_RUN_ON_CPU	(1U << 0)
1451/* If set, XDP frames will be transmitted after processing */
1452#define BPF_F_TEST_XDP_LIVE_FRAMES	(1U << 1)
1453/* If set, apply CHECKSUM_COMPLETE to skb and validate the checksum */
1454#define BPF_F_TEST_SKB_CHECKSUM_COMPLETE	(1U << 2)
1455
1456/* type for BPF_ENABLE_STATS */
1457enum bpf_stats_type {
1458	/* enabled run_time_ns and run_cnt */
1459	BPF_STATS_RUN_TIME = 0,
1460};
1461
1462enum bpf_stack_build_id_status {
1463	/* user space need an empty entry to identify end of a trace */
1464	BPF_STACK_BUILD_ID_EMPTY = 0,
1465	/* with valid build_id and offset */
1466	BPF_STACK_BUILD_ID_VALID = 1,
1467	/* couldn't get build_id, fallback to ip */
1468	BPF_STACK_BUILD_ID_IP = 2,
1469};
1470
1471#define BPF_BUILD_ID_SIZE 20
1472struct bpf_stack_build_id {
1473	__s32		status;
1474	unsigned char	build_id[BPF_BUILD_ID_SIZE];
1475	union {
1476		__u64	offset;
1477		__u64	ip;
1478	};
1479};
1480
1481#define BPF_OBJ_NAME_LEN 16U
1482
1483enum {
1484	BPF_STREAM_STDOUT = 1,
1485	BPF_STREAM_STDERR = 2,
1486};
1487
1488union bpf_attr {
1489	struct { /* anonymous struct used by BPF_MAP_CREATE command */
1490		__u32	map_type;	/* one of enum bpf_map_type */
1491		__u32	key_size;	/* size of key in bytes */
1492		__u32	value_size;	/* size of value in bytes */
1493		__u32	max_entries;	/* max number of entries in a map */
1494		__u32	map_flags;	/* BPF_MAP_CREATE related
1495					 * flags defined above.
1496					 */
1497		__u32	inner_map_fd;	/* fd pointing to the inner map */
1498		__u32	numa_node;	/* numa node (effective only if
1499					 * BPF_F_NUMA_NODE is set).
1500					 */
1501		char	map_name[BPF_OBJ_NAME_LEN];
1502		__u32	map_ifindex;	/* ifindex of netdev to create on */
1503		__u32	btf_fd;		/* fd pointing to a BTF type data */
1504		__u32	btf_key_type_id;	/* BTF type_id of the key */
1505		__u32	btf_value_type_id;	/* BTF type_id of the value */
1506		__u32	btf_vmlinux_value_type_id;/* BTF type_id of a kernel-
1507						   * struct stored as the
1508						   * map value
1509						   */
1510		/* Any per-map-type extra fields
1511		 *
1512		 * BPF_MAP_TYPE_BLOOM_FILTER - the lowest 4 bits indicate the
1513		 * number of hash functions (if 0, the bloom filter will default
1514		 * to using 5 hash functions).
1515		 *
1516		 * BPF_MAP_TYPE_ARENA - contains the address where user space
1517		 * is going to mmap() the arena. It has to be page aligned.
1518		 */
1519		__u64	map_extra;
1520
1521		__s32   value_type_btf_obj_fd;	/* fd pointing to a BTF
1522						 * type data for
1523						 * btf_vmlinux_value_type_id.
1524						 */
1525		/* BPF token FD to use with BPF_MAP_CREATE operation.
1526		 * If provided, map_flags should have BPF_F_TOKEN_FD flag set.
1527		 */
1528		__s32	map_token_fd;
1529
1530		/* Hash of the program that has exclusive access to the map.
1531		 */
1532		__aligned_u64 excl_prog_hash;
1533		/* Size of the passed excl_prog_hash. */
1534		__u32 excl_prog_hash_size;
1535	};
1536
1537	struct { /* anonymous struct used by BPF_MAP_*_ELEM and BPF_MAP_FREEZE commands */
1538		__u32		map_fd;
1539		__aligned_u64	key;
1540		union {
1541			__aligned_u64 value;
1542			__aligned_u64 next_key;
1543		};
1544		__u64		flags;
1545	};
1546
1547	struct { /* struct used by BPF_MAP_*_BATCH commands */
1548		__aligned_u64	in_batch;	/* start batch,
1549						 * NULL to start from beginning
1550						 */
1551		__aligned_u64	out_batch;	/* output: next start batch */
1552		__aligned_u64	keys;
1553		__aligned_u64	values;
1554		__u32		count;		/* input/output:
1555						 * input: # of key/value
1556						 * elements
1557						 * output: # of filled elements
1558						 */
1559		__u32		map_fd;
1560		__u64		elem_flags;
1561		__u64		flags;
1562	} batch;
1563
1564	struct { /* anonymous struct used by BPF_PROG_LOAD command */
1565		__u32		prog_type;	/* one of enum bpf_prog_type */
1566		__u32		insn_cnt;
1567		__aligned_u64	insns;
1568		__aligned_u64	license;
1569		__u32		log_level;	/* verbosity level of verifier */
1570		__u32		log_size;	/* size of user buffer */
1571		__aligned_u64	log_buf;	/* user supplied buffer */
1572		__u32		kern_version;	/* not used */
1573		__u32		prog_flags;
1574		char		prog_name[BPF_OBJ_NAME_LEN];
1575		__u32		prog_ifindex;	/* ifindex of netdev to prep for */
1576		/* For some prog types expected attach type must be known at
1577		 * load time to verify attach type specific parts of prog
1578		 * (context accesses, allowed helpers, etc).
1579		 */
1580		__u32		expected_attach_type;
1581		__u32		prog_btf_fd;	/* fd pointing to BTF type data */
1582		__u32		func_info_rec_size;	/* userspace bpf_func_info size */
1583		__aligned_u64	func_info;	/* func info */
1584		__u32		func_info_cnt;	/* number of bpf_func_info records */
1585		__u32		line_info_rec_size;	/* userspace bpf_line_info size */
1586		__aligned_u64	line_info;	/* line info */
1587		__u32		line_info_cnt;	/* number of bpf_line_info records */
1588		__u32		attach_btf_id;	/* in-kernel BTF type id to attach to */
1589		union {
1590			/* valid prog_fd to attach to bpf prog */
1591			__u32		attach_prog_fd;
1592			/* or valid module BTF object fd or 0 to attach to vmlinux */
1593			__u32		attach_btf_obj_fd;
1594		};
1595		__u32		core_relo_cnt;	/* number of bpf_core_relo */
1596		__aligned_u64	fd_array;	/* array of FDs */
1597		__aligned_u64	core_relos;
1598		__u32		core_relo_rec_size; /* sizeof(struct bpf_core_relo) */
1599		/* output: actual total log contents size (including termintaing zero).
1600		 * It could be both larger than original log_size (if log was
1601		 * truncated), or smaller (if log buffer wasn't filled completely).
1602		 */
1603		__u32		log_true_size;
1604		/* BPF token FD to use with BPF_PROG_LOAD operation.
1605		 * If provided, prog_flags should have BPF_F_TOKEN_FD flag set.
1606		 */
1607		__s32		prog_token_fd;
1608		/* The fd_array_cnt can be used to pass the length of the
1609		 * fd_array array. In this case all the [map] file descriptors
1610		 * passed in this array will be bound to the program, even if
1611		 * the maps are not referenced directly. The functionality is
1612		 * similar to the BPF_PROG_BIND_MAP syscall, but maps can be
1613		 * used by the verifier during the program load. If provided,
1614		 * then the fd_array[0,...,fd_array_cnt-1] is expected to be
1615		 * continuous.
1616		 */
1617		__u32		fd_array_cnt;
1618		/* Pointer to a buffer containing the signature of the BPF
1619		 * program.
1620		 */
1621		__aligned_u64   signature;
1622		/* Size of the signature buffer in bytes. */
1623		__u32 		signature_size;
1624		/* ID of the kernel keyring to be used for signature
1625		 * verification.
1626		 */
1627		__s32		keyring_id;
1628	};
1629
1630	struct { /* anonymous struct used by BPF_OBJ_* commands */
1631		__aligned_u64	pathname;
1632		__u32		bpf_fd;
1633		__u32		file_flags;
1634		/* Same as dirfd in openat() syscall; see openat(2)
1635		 * manpage for details of path FD and pathname semantics;
1636		 * path_fd should accompanied by BPF_F_PATH_FD flag set in
1637		 * file_flags field, otherwise it should be set to zero;
1638		 * if BPF_F_PATH_FD flag is not set, AT_FDCWD is assumed.
1639		 */
1640		__s32		path_fd;
1641	};
1642
1643	struct { /* anonymous struct used by BPF_PROG_ATTACH/DETACH commands */
1644		union {
1645			__u32	target_fd;	/* target object to attach to or ... */
1646			__u32	target_ifindex;	/* target ifindex */
1647		};
1648		__u32		attach_bpf_fd;
1649		__u32		attach_type;
1650		__u32		attach_flags;
1651		__u32		replace_bpf_fd;
1652		union {
1653			__u32	relative_fd;
1654			__u32	relative_id;
1655		};
1656		__u64		expected_revision;
1657	};
1658
1659	struct { /* anonymous struct used by BPF_PROG_TEST_RUN command */
1660		__u32		prog_fd;
1661		__u32		retval;
1662		__u32		data_size_in;	/* input: len of data_in */
1663		__u32		data_size_out;	/* input/output: len of data_out
1664						 *   returns ENOSPC if data_out
1665						 *   is too small.
1666						 */
1667		__aligned_u64	data_in;
1668		__aligned_u64	data_out;
1669		__u32		repeat;
1670		__u32		duration;
1671		__u32		ctx_size_in;	/* input: len of ctx_in */
1672		__u32		ctx_size_out;	/* input/output: len of ctx_out
1673						 *   returns ENOSPC if ctx_out
1674						 *   is too small.
1675						 */
1676		__aligned_u64	ctx_in;
1677		__aligned_u64	ctx_out;
1678		__u32		flags;
1679		__u32		cpu;
1680		__u32		batch_size;
1681	} test;
1682
1683	struct { /* anonymous struct used by BPF_*_GET_*_ID */
1684		union {
1685			__u32		start_id;
1686			__u32		prog_id;
1687			__u32		map_id;
1688			__u32		btf_id;
1689			__u32		link_id;
1690		};
1691		__u32		next_id;
1692		__u32		open_flags;
1693		__s32		fd_by_id_token_fd;
1694	};
1695
1696	struct { /* anonymous struct used by BPF_OBJ_GET_INFO_BY_FD */
1697		__u32		bpf_fd;
1698		__u32		info_len;
1699		__aligned_u64	info;
1700	} info;
1701
1702	struct { /* anonymous struct used by BPF_PROG_QUERY command */
1703		union {
1704			__u32	target_fd;	/* target object to query or ... */
1705			__u32	target_ifindex;	/* target ifindex */
1706		};
1707		__u32		attach_type;
1708		__u32		query_flags;
1709		__u32		attach_flags;
1710		__aligned_u64	prog_ids;
1711		union {
1712			__u32	prog_cnt;
1713			__u32	count;
1714		};
1715		__u32		:32;
1716		/* output: per-program attach_flags.
1717		 * not allowed to be set during effective query.
1718		 */
1719		__aligned_u64	prog_attach_flags;
1720		__aligned_u64	link_ids;
1721		__aligned_u64	link_attach_flags;
1722		__u64		revision;
1723	} query;
1724
1725	struct { /* anonymous struct used by BPF_RAW_TRACEPOINT_OPEN command */
1726		__u64		name;
1727		__u32		prog_fd;
1728		__u32		:32;
1729		__aligned_u64	cookie;
1730	} raw_tracepoint;
1731
1732	struct { /* anonymous struct for BPF_BTF_LOAD */
1733		__aligned_u64	btf;
1734		__aligned_u64	btf_log_buf;
1735		__u32		btf_size;
1736		__u32		btf_log_size;
1737		__u32		btf_log_level;
1738		/* output: actual total log contents size (including termintaing zero).
1739		 * It could be both larger than original log_size (if log was
1740		 * truncated), or smaller (if log buffer wasn't filled completely).
1741		 */
1742		__u32		btf_log_true_size;
1743		__u32		btf_flags;
1744		/* BPF token FD to use with BPF_BTF_LOAD operation.
1745		 * If provided, btf_flags should have BPF_F_TOKEN_FD flag set.
1746		 */
1747		__s32		btf_token_fd;
1748	};
1749
1750	struct {
1751		__u32		pid;		/* input: pid */
1752		__u32		fd;		/* input: fd */
1753		__u32		flags;		/* input: flags */
1754		__u32		buf_len;	/* input/output: buf len */
1755		__aligned_u64	buf;		/* input/output:
1756						 *   tp_name for tracepoint
1757						 *   symbol for kprobe
1758						 *   filename for uprobe
1759						 */
1760		__u32		prog_id;	/* output: prod_id */
1761		__u32		fd_type;	/* output: BPF_FD_TYPE_* */
1762		__u64		probe_offset;	/* output: probe_offset */
1763		__u64		probe_addr;	/* output: probe_addr */
1764	} task_fd_query;
1765
1766	struct { /* struct used by BPF_LINK_CREATE command */
1767		union {
1768			__u32		prog_fd;	/* eBPF program to attach */
1769			__u32		map_fd;		/* struct_ops to attach */
1770		};
1771		union {
1772			__u32	target_fd;	/* target object to attach to or ... */
1773			__u32	target_ifindex; /* target ifindex */
1774		};
1775		__u32		attach_type;	/* attach type */
1776		__u32		flags;		/* extra flags */
1777		union {
1778			__u32	target_btf_id;	/* btf_id of target to attach to */
1779			struct {
1780				__aligned_u64	iter_info;	/* extra bpf_iter_link_info */
1781				__u32		iter_info_len;	/* iter_info length */
1782			};
1783			struct {
1784				/* black box user-provided value passed through
1785				 * to BPF program at the execution time and
1786				 * accessible through bpf_get_attach_cookie() BPF helper
1787				 */
1788				__u64		bpf_cookie;
1789			} perf_event;
1790			struct {
1791				__u32		flags;
1792				__u32		cnt;
1793				__aligned_u64	syms;
1794				__aligned_u64	addrs;
1795				__aligned_u64	cookies;
1796			} kprobe_multi;
1797			struct {
1798				/* this is overlaid with the target_btf_id above. */
1799				__u32		target_btf_id;
1800				/* black box user-provided value passed through
1801				 * to BPF program at the execution time and
1802				 * accessible through bpf_get_attach_cookie() BPF helper
1803				 */
1804				__u64		cookie;
1805			} tracing;
1806			struct {
1807				__u32		pf;
1808				__u32		hooknum;
1809				__s32		priority;
1810				__u32		flags;
1811			} netfilter;
1812			struct {
1813				union {
1814					__u32	relative_fd;
1815					__u32	relative_id;
1816				};
1817				__u64		expected_revision;
1818			} tcx;
1819			struct {
1820				__aligned_u64	path;
1821				__aligned_u64	offsets;
1822				__aligned_u64	ref_ctr_offsets;
1823				__aligned_u64	cookies;
1824				__u32		cnt;
1825				__u32		flags;
1826				__u32		pid;
1827			} uprobe_multi;
1828			struct {
1829				union {
1830					__u32	relative_fd;
1831					__u32	relative_id;
1832				};
1833				__u64		expected_revision;
1834			} netkit;
1835			struct {
1836				union {
1837					__u32	relative_fd;
1838					__u32	relative_id;
1839				};
1840				__u64		expected_revision;
1841			} cgroup;
1842		};
1843	} link_create;
1844
1845	struct { /* struct used by BPF_LINK_UPDATE command */
1846		__u32		link_fd;	/* link fd */
1847		union {
1848			/* new program fd to update link with */
1849			__u32		new_prog_fd;
1850			/* new struct_ops map fd to update link with */
1851			__u32           new_map_fd;
1852		};
1853		__u32		flags;		/* extra flags */
1854		union {
1855			/* expected link's program fd; is specified only if
1856			 * BPF_F_REPLACE flag is set in flags.
1857			 */
1858			__u32		old_prog_fd;
1859			/* expected link's map fd; is specified only
1860			 * if BPF_F_REPLACE flag is set.
1861			 */
1862			__u32           old_map_fd;
1863		};
1864	} link_update;
1865
1866	struct {
1867		__u32		link_fd;
1868	} link_detach;
1869
1870	struct { /* struct used by BPF_ENABLE_STATS command */
1871		__u32		type;
1872	} enable_stats;
1873
1874	struct { /* struct used by BPF_ITER_CREATE command */
1875		__u32		link_fd;
1876		__u32		flags;
1877	} iter_create;
1878
1879	struct { /* struct used by BPF_PROG_BIND_MAP command */
1880		__u32		prog_fd;
1881		__u32		map_fd;
1882		__u32		flags;		/* extra flags */
1883	} prog_bind_map;
1884
1885	struct { /* struct used by BPF_TOKEN_CREATE command */
1886		__u32		flags;
1887		__u32		bpffs_fd;
1888	} token_create;
1889
1890	struct {
1891		__aligned_u64	stream_buf;
1892		__u32		stream_buf_len;
1893		__u32		stream_id;
1894		__u32		prog_fd;
1895	} prog_stream_read;
1896
1897} __attribute__((aligned(8)));
1898
1899/* The description below is an attempt at providing documentation to eBPF
1900 * developers about the multiple available eBPF helper functions. It can be
1901 * parsed and used to produce a manual page. The workflow is the following,
1902 * and requires the rst2man utility:
1903 *
1904 *     $ ./scripts/bpf_doc.py \
1905 *             --filename include/uapi/linux/bpf.h > /tmp/bpf-helpers.rst
1906 *     $ rst2man /tmp/bpf-helpers.rst > /tmp/bpf-helpers.7
1907 *     $ man /tmp/bpf-helpers.7
1908 *
1909 * Note that in order to produce this external documentation, some RST
1910 * formatting is used in the descriptions to get "bold" and "italics" in
1911 * manual pages. Also note that the few trailing white spaces are
1912 * intentional, removing them would break paragraphs for rst2man.
1913 *
1914 * Start of BPF helper function descriptions:
1915 *
1916 * void *bpf_map_lookup_elem(struct bpf_map *map, const void *key)
1917 * 	Description
1918 * 		Perform a lookup in *map* for an entry associated to *key*.
1919 * 	Return
1920 * 		Map value associated to *key*, or **NULL** if no entry was
1921 * 		found.
1922 *
1923 * long bpf_map_update_elem(struct bpf_map *map, const void *key, const void *value, u64 flags)
1924 * 	Description
1925 * 		Add or update the value of the entry associated to *key* in
1926 * 		*map* with *value*. *flags* is one of:
1927 *
1928 * 		**BPF_NOEXIST**
1929 * 			The entry for *key* must not exist in the map.
1930 * 		**BPF_EXIST**
1931 * 			The entry for *key* must already exist in the map.
1932 * 		**BPF_ANY**
1933 * 			No condition on the existence of the entry for *key*.
1934 *
1935 * 		Flag value **BPF_NOEXIST** cannot be used for maps of types
1936 * 		**BPF_MAP_TYPE_ARRAY** or **BPF_MAP_TYPE_PERCPU_ARRAY**  (all
1937 * 		elements always exist), the helper would return an error.
1938 * 	Return
1939 * 		0 on success, or a negative error in case of failure.
1940 *
1941 * long bpf_map_delete_elem(struct bpf_map *map, const void *key)
1942 * 	Description
1943 * 		Delete entry with *key* from *map*.
1944 * 	Return
1945 * 		0 on success, or a negative error in case of failure.
1946 *
1947 * long bpf_probe_read(void *dst, u32 size, const void *unsafe_ptr)
1948 * 	Description
1949 * 		For tracing programs, safely attempt to read *size* bytes from
1950 * 		kernel space address *unsafe_ptr* and store the data in *dst*.
1951 *
1952 * 		Generally, use **bpf_probe_read_user**\ () or
1953 * 		**bpf_probe_read_kernel**\ () instead.
1954 * 	Return
1955 * 		0 on success, or a negative error in case of failure.
1956 *
1957 * u64 bpf_ktime_get_ns(void)
1958 * 	Description
1959 * 		Return the time elapsed since system boot, in nanoseconds.
1960 * 		Does not include time the system was suspended.
1961 * 		See: **clock_gettime**\ (**CLOCK_MONOTONIC**)
1962 * 	Return
1963 * 		Current *ktime*.
1964 *
1965 * long bpf_trace_printk(const char *fmt, u32 fmt_size, ...)
1966 * 	Description
1967 * 		This helper is a "printk()-like" facility for debugging. It
1968 * 		prints a message defined by format *fmt* (of size *fmt_size*)
1969 * 		to file *\/sys/kernel/tracing/trace* from TraceFS, if
1970 * 		available. It can take up to three additional **u64**
1971 * 		arguments (as an eBPF helpers, the total number of arguments is
1972 * 		limited to five).
1973 *
1974 * 		Each time the helper is called, it appends a line to the trace.
1975 * 		Lines are discarded while *\/sys/kernel/tracing/trace* is
1976 * 		open, use *\/sys/kernel/tracing/trace_pipe* to avoid this.
1977 * 		The format of the trace is customizable, and the exact output
1978 * 		one will get depends on the options set in
1979 * 		*\/sys/kernel/tracing/trace_options* (see also the
1980 * 		*README* file under the same directory). However, it usually
1981 * 		defaults to something like:
1982 *
1983 * 		::
1984 *
1985 * 			telnet-470   [001] .N.. 419421.045894: 0x00000001: <formatted msg>
1986 *
1987 * 		In the above:
1988 *
1989 * 			* ``telnet`` is the name of the current task.
1990 * 			* ``470`` is the PID of the current task.
1991 * 			* ``001`` is the CPU number on which the task is
1992 * 			  running.
1993 * 			* In ``.N..``, each character refers to a set of
1994 * 			  options (whether irqs are enabled, scheduling
1995 * 			  options, whether hard/softirqs are running, level of
1996 * 			  preempt_disabled respectively). **N** means that
1997 * 			  **TIF_NEED_RESCHED** and **PREEMPT_NEED_RESCHED**
1998 * 			  are set.
1999 * 			* ``419421.045894`` is a timestamp.
2000 * 			* ``0x00000001`` is a fake value used by BPF for the
2001 * 			  instruction pointer register.
2002 * 			* ``<formatted msg>`` is the message formatted with
2003 * 			  *fmt*.
2004 *
2005 * 		The conversion specifiers supported by *fmt* are similar, but
2006 * 		more limited than for printk(). They are **%d**, **%i**,
2007 * 		**%u**, **%x**, **%ld**, **%li**, **%lu**, **%lx**, **%lld**,
2008 * 		**%lli**, **%llu**, **%llx**, **%p**, **%s**. No modifier (size
2009 * 		of field, padding with zeroes, etc.) is available, and the
2010 * 		helper will return **-EINVAL** (but print nothing) if it
2011 * 		encounters an unknown specifier.
2012 *
2013 * 		Also, note that **bpf_trace_printk**\ () is slow, and should
2014 * 		only be used for debugging purposes. For this reason, a notice
2015 * 		block (spanning several lines) is printed to kernel logs and
2016 * 		states that the helper should not be used "for production use"
2017 * 		the first time this helper is used (or more precisely, when
2018 * 		**trace_printk**\ () buffers are allocated). For passing values
2019 * 		to user space, perf events should be preferred.
2020 * 	Return
2021 * 		The number of bytes written to the buffer, or a negative error
2022 * 		in case of failure.
2023 *
2024 * u32 bpf_get_prandom_u32(void)
2025 * 	Description
2026 * 		Get a pseudo-random number.
2027 *
2028 * 		From a security point of view, this helper uses its own
2029 * 		pseudo-random internal state, and cannot be used to infer the
2030 * 		seed of other random functions in the kernel. However, it is
2031 * 		essential to note that the generator used by the helper is not
2032 * 		cryptographically secure.
2033 * 	Return
2034 * 		A random 32-bit unsigned value.
2035 *
2036 * u32 bpf_get_smp_processor_id(void)
2037 * 	Description
2038 * 		Get the SMP (symmetric multiprocessing) processor id. Note that
2039 * 		all programs run with migration disabled, which means that the
2040 * 		SMP processor id is stable during all the execution of the
2041 * 		program.
2042 * 	Return
2043 * 		The SMP id of the processor running the program.
2044 * 	Attributes
2045 * 		__bpf_fastcall
2046 *
2047 * long bpf_skb_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len, u64 flags)
2048 * 	Description
2049 * 		Store *len* bytes from address *from* into the packet
2050 * 		associated to *skb*, at *offset*. The *flags* are a combination
2051 * 		of the following values:
2052 *
2053 * 		**BPF_F_RECOMPUTE_CSUM**
2054 * 			Automatically update *skb*\ **->csum** after storing the
2055 * 			bytes.
2056 * 		**BPF_F_INVALIDATE_HASH**
2057 * 			Set *skb*\ **->hash**, *skb*\ **->swhash** and *skb*\
2058 * 			**->l4hash** to 0.
2059 *
2060 * 		A call to this helper is susceptible to change the underlying
2061 * 		packet buffer. Therefore, at load time, all checks on pointers
2062 * 		previously done by the verifier are invalidated and must be
2063 * 		performed again, if the helper is used in combination with
2064 * 		direct packet access.
2065 * 	Return
2066 * 		0 on success, or a negative error in case of failure.
2067 *
2068 * long bpf_l3_csum_replace(struct sk_buff *skb, u32 offset, u64 from, u64 to, u64 size)
2069 * 	Description
2070 * 		Recompute the layer 3 (e.g. IP) checksum for the packet
2071 * 		associated to *skb*. Computation is incremental, so the helper
2072 * 		must know the former value of the header field that was
2073 * 		modified (*from*), the new value of this field (*to*), and the
2074 * 		number of bytes (2 or 4) for this field, stored in *size*.
2075 * 		Alternatively, it is possible to store the difference between
2076 * 		the previous and the new values of the header field in *to*, by
2077 * 		setting *from* and *size* to 0. For both methods, *offset*
2078 * 		indicates the location of the IP checksum within the packet.
2079 *
2080 * 		This helper works in combination with **bpf_csum_diff**\ (),
2081 * 		which does not update the checksum in-place, but offers more
2082 * 		flexibility and can handle sizes larger than 2 or 4 for the
2083 * 		checksum to update.
2084 *
2085 * 		A call to this helper is susceptible to change the underlying
2086 * 		packet buffer. Therefore, at load time, all checks on pointers
2087 * 		previously done by the verifier are invalidated and must be
2088 * 		performed again, if the helper is used in combination with
2089 * 		direct packet access.
2090 * 	Return
2091 * 		0 on success, or a negative error in case of failure.
2092 *
2093 * long bpf_l4_csum_replace(struct sk_buff *skb, u32 offset, u64 from, u64 to, u64 flags)
2094 * 	Description
2095 * 		Recompute the layer 4 (e.g. TCP, UDP or ICMP) checksum for the
2096 * 		packet associated to *skb*. Computation is incremental, so the
2097 * 		helper must know the former value of the header field that was
2098 * 		modified (*from*), the new value of this field (*to*), and the
2099 * 		number of bytes (2 or 4) for this field, stored on the lowest
2100 * 		four bits of *flags*. Alternatively, it is possible to store
2101 * 		the difference between the previous and the new values of the
2102 * 		header field in *to*, by setting *from* and the four lowest
2103 * 		bits of *flags* to 0. For both methods, *offset* indicates the
2104 * 		location of the IP checksum within the packet. In addition to
2105 * 		the size of the field, *flags* can be added (bitwise OR) actual
2106 * 		flags. With **BPF_F_MARK_MANGLED_0**, a null checksum is left
2107 * 		untouched (unless **BPF_F_MARK_ENFORCE** is added as well), and
2108 * 		for updates resulting in a null checksum the value is set to
2109 * 		**CSUM_MANGLED_0** instead. Flag **BPF_F_PSEUDO_HDR** indicates
2110 * 		that the modified header field is part of the pseudo-header.
2111 * 		Flag **BPF_F_IPV6** should be set for IPv6 packets.
2112 *
2113 * 		This helper works in combination with **bpf_csum_diff**\ (),
2114 * 		which does not update the checksum in-place, but offers more
2115 * 		flexibility and can handle sizes larger than 2 or 4 for the
2116 * 		checksum to update.
2117 *
2118 * 		A call to this helper is susceptible to change the underlying
2119 * 		packet buffer. Therefore, at load time, all checks on pointers
2120 * 		previously done by the verifier are invalidated and must be
2121 * 		performed again, if the helper is used in combination with
2122 * 		direct packet access.
2123 * 	Return
2124 * 		0 on success, or a negative error in case of failure.
2125 *
2126 * long bpf_tail_call(void *ctx, struct bpf_map *prog_array_map, u32 index)
2127 * 	Description
2128 * 		This special helper is used to trigger a "tail call", or in
2129 * 		other words, to jump into another eBPF program. The same stack
2130 * 		frame is used (but values on stack and in registers for the
2131 * 		caller are not accessible to the callee). This mechanism allows
2132 * 		for program chaining, either for raising the maximum number of
2133 * 		available eBPF instructions, or to execute given programs in
2134 * 		conditional blocks. For security reasons, there is an upper
2135 * 		limit to the number of successive tail calls that can be
2136 * 		performed.
2137 *
2138 * 		Upon call of this helper, the program attempts to jump into a
2139 * 		program referenced at index *index* in *prog_array_map*, a
2140 * 		special map of type **BPF_MAP_TYPE_PROG_ARRAY**, and passes
2141 * 		*ctx*, a pointer to the context.
2142 *
2143 * 		If the call succeeds, the kernel immediately runs the first
2144 * 		instruction of the new program. This is not a function call,
2145 * 		and it never returns to the previous program. If the call
2146 * 		fails, then the helper has no effect, and the caller continues
2147 * 		to run its subsequent instructions. A call can fail if the
2148 * 		destination program for the jump does not exist (i.e. *index*
2149 * 		is superior to the number of entries in *prog_array_map*), or
2150 * 		if the maximum number of tail calls has been reached for this
2151 * 		chain of programs. This limit is defined in the kernel by the
2152 * 		macro **MAX_TAIL_CALL_CNT** (not accessible to user space),
2153 *		which is currently set to 33.
2154 * 	Return
2155 * 		0 on success, or a negative error in case of failure.
2156 *
2157 * long bpf_clone_redirect(struct sk_buff *skb, u32 ifindex, u64 flags)
2158 * 	Description
2159 * 		Clone and redirect the packet associated to *skb* to another
2160 * 		net device of index *ifindex*. Both ingress and egress
2161 * 		interfaces can be used for redirection. The **BPF_F_INGRESS**
2162 * 		value in *flags* is used to make the distinction (ingress path
2163 * 		is selected if the flag is present, egress path otherwise).
2164 * 		This is the only flag supported for now.
2165 *
2166 * 		In comparison with **bpf_redirect**\ () helper,
2167 * 		**bpf_clone_redirect**\ () has the associated cost of
2168 * 		duplicating the packet buffer, but this can be executed out of
2169 * 		the eBPF program. Conversely, **bpf_redirect**\ () is more
2170 * 		efficient, but it is handled through an action code where the
2171 * 		redirection happens only after the eBPF program has returned.
2172 *
2173 * 		A call to this helper is susceptible to change the underlying
2174 * 		packet buffer. Therefore, at load time, all checks on pointers
2175 * 		previously done by the verifier are invalidated and must be
2176 * 		performed again, if the helper is used in combination with
2177 * 		direct packet access.
2178 * 	Return
2179 * 		0 on success, or a negative error in case of failure. Positive
2180 * 		error indicates a potential drop or congestion in the target
2181 * 		device. The particular positive error codes are not defined.
2182 *
2183 * u64 bpf_get_current_pid_tgid(void)
2184 * 	Description
2185 * 		Get the current pid and tgid.
2186 * 	Return
2187 * 		A 64-bit integer containing the current tgid and pid, and
2188 * 		created as such:
2189 * 		*current_task*\ **->tgid << 32 \|**
2190 * 		*current_task*\ **->pid**.
2191 *
2192 * u64 bpf_get_current_uid_gid(void)
2193 * 	Description
2194 * 		Get the current uid and gid.
2195 * 	Return
2196 * 		A 64-bit integer containing the current GID and UID, and
2197 * 		created as such: *current_gid* **<< 32 \|** *current_uid*.
2198 *
2199 * long bpf_get_current_comm(void *buf, u32 size_of_buf)
2200 * 	Description
2201 * 		Copy the **comm** attribute of the current task into *buf* of
2202 * 		*size_of_buf*. The **comm** attribute contains the name of
2203 * 		the executable (excluding the path) for the current task. The
2204 * 		*size_of_buf* must be strictly positive. On success, the
2205 * 		helper makes sure that the *buf* is NUL-terminated. On failure,
2206 * 		it is filled with zeroes.
2207 * 	Return
2208 * 		0 on success, or a negative error in case of failure.
2209 *
2210 * u32 bpf_get_cgroup_classid(struct sk_buff *skb)
2211 * 	Description
2212 * 		Retrieve the classid for the current task, i.e. for the net_cls
2213 * 		cgroup to which *skb* belongs.
2214 *
2215 * 		This helper can be used on TC egress path, but not on ingress.
2216 *
2217 * 		The net_cls cgroup provides an interface to tag network packets
2218 * 		based on a user-provided identifier for all traffic coming from
2219 * 		the tasks belonging to the related cgroup. See also the related
2220 * 		kernel documentation, available from the Linux sources in file
2221 * 		*Documentation/admin-guide/cgroup-v1/net_cls.rst*.
2222 *
2223 * 		The Linux kernel has two versions for cgroups: there are
2224 * 		cgroups v1 and cgroups v2. Both are available to users, who can
2225 * 		use a mixture of them, but note that the net_cls cgroup is for
2226 * 		cgroup v1 only. This makes it incompatible with BPF programs
2227 * 		run on cgroups, which is a cgroup-v2-only feature (a socket can
2228 * 		only hold data for one version of cgroups at a time).
2229 *
2230 * 		This helper is only available is the kernel was compiled with
2231 * 		the **CONFIG_CGROUP_NET_CLASSID** configuration option set to
2232 * 		"**y**" or to "**m**".
2233 * 	Return
2234 * 		The classid, or 0 for the default unconfigured classid.
2235 *
2236 * long bpf_skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci)
2237 * 	Description
2238 * 		Push a *vlan_tci* (VLAN tag control information) of protocol
2239 * 		*vlan_proto* to the packet associated to *skb*, then update
2240 * 		the checksum. Note that if *vlan_proto* is different from
2241 * 		**ETH_P_8021Q** and **ETH_P_8021AD**, it is considered to
2242 * 		be **ETH_P_8021Q**.
2243 *
2244 * 		A call to this helper is susceptible to change the underlying
2245 * 		packet buffer. Therefore, at load time, all checks on pointers
2246 * 		previously done by the verifier are invalidated and must be
2247 * 		performed again, if the helper is used in combination with
2248 * 		direct packet access.
2249 * 	Return
2250 * 		0 on success, or a negative error in case of failure.
2251 *
2252 * long bpf_skb_vlan_pop(struct sk_buff *skb)
2253 * 	Description
2254 * 		Pop a VLAN header from the packet associated to *skb*.
2255 *
2256 * 		A call to this helper is susceptible to change the underlying
2257 * 		packet buffer. Therefore, at load time, all checks on pointers
2258 * 		previously done by the verifier are invalidated and must be
2259 * 		performed again, if the helper is used in combination with
2260 * 		direct packet access.
2261 * 	Return
2262 * 		0 on success, or a negative error in case of failure.
2263 *
2264 * long bpf_skb_get_tunnel_key(struct sk_buff *skb, struct bpf_tunnel_key *key, u32 size, u64 flags)
2265 * 	Description
2266 * 		Get tunnel metadata. This helper takes a pointer *key* to an
2267 * 		empty **struct bpf_tunnel_key** of **size**, that will be
2268 * 		filled with tunnel metadata for the packet associated to *skb*.
2269 * 		The *flags* can be set to **BPF_F_TUNINFO_IPV6**, which
2270 * 		indicates that the tunnel is based on IPv6 protocol instead of
2271 * 		IPv4.
2272 *
2273 * 		The **struct bpf_tunnel_key** is an object that generalizes the
2274 * 		principal parameters used by various tunneling protocols into a
2275 * 		single struct. This way, it can be used to easily make a
2276 * 		decision based on the contents of the encapsulation header,
2277 * 		"summarized" in this struct. In particular, it holds the IP
2278 * 		address of the remote end (IPv4 or IPv6, depending on the case)
2279 * 		in *key*\ **->remote_ipv4** or *key*\ **->remote_ipv6**. Also,
2280 * 		this struct exposes the *key*\ **->tunnel_id**, which is
2281 * 		generally mapped to a VNI (Virtual Network Identifier), making
2282 * 		it programmable together with the **bpf_skb_set_tunnel_key**\
2283 * 		() helper.
2284 *
2285 * 		Let's imagine that the following code is part of a program
2286 * 		attached to the TC ingress interface, on one end of a GRE
2287 * 		tunnel, and is supposed to filter out all messages coming from
2288 * 		remote ends with IPv4 address other than 10.0.0.1:
2289 *
2290 * 		::
2291 *
2292 * 			int ret;
2293 * 			struct bpf_tunnel_key key = {};
2294 *
2295 * 			ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
2296 * 			if (ret < 0)
2297 * 				return TC_ACT_SHOT;	// drop packet
2298 *
2299 * 			if (key.remote_ipv4 != 0x0a000001)
2300 * 				return TC_ACT_SHOT;	// drop packet
2301 *
2302 * 			return TC_ACT_OK;		// accept packet
2303 *
2304 * 		This interface can also be used with all encapsulation devices
2305 * 		that can operate in "collect metadata" mode: instead of having
2306 * 		one network device per specific configuration, the "collect
2307 * 		metadata" mode only requires a single device where the
2308 * 		configuration can be extracted from this helper.
2309 *
2310 * 		This can be used together with various tunnels such as VXLan,
2311 * 		Geneve, GRE or IP in IP (IPIP).
2312 * 	Return
2313 * 		0 on success, or a negative error in case of failure.
2314 *
2315 * long bpf_skb_set_tunnel_key(struct sk_buff *skb, struct bpf_tunnel_key *key, u32 size, u64 flags)
2316 * 	Description
2317 * 		Populate tunnel metadata for packet associated to *skb.* The
2318 * 		tunnel metadata is set to the contents of *key*, of *size*. The
2319 * 		*flags* can be set to a combination of the following values:
2320 *
2321 * 		**BPF_F_TUNINFO_IPV6**
2322 * 			Indicate that the tunnel is based on IPv6 protocol
2323 * 			instead of IPv4.
2324 * 		**BPF_F_ZERO_CSUM_TX**
2325 * 			For IPv4 packets, add a flag to tunnel metadata
2326 * 			indicating that checksum computation should be skipped
2327 * 			and checksum set to zeroes.
2328 * 		**BPF_F_DONT_FRAGMENT**
2329 * 			Add a flag to tunnel metadata indicating that the
2330 * 			packet should not be fragmented.
2331 * 		**BPF_F_SEQ_NUMBER**
2332 * 			Add a flag to tunnel metadata indicating that a
2333 * 			sequence number should be added to tunnel header before
2334 * 			sending the packet. This flag was added for GRE
2335 * 			encapsulation, but might be used with other protocols
2336 * 			as well in the future.
2337 * 		**BPF_F_NO_TUNNEL_KEY**
2338 * 			Add a flag to tunnel metadata indicating that no tunnel
2339 * 			key should be set in the resulting tunnel header.
2340 *
2341 * 		Here is a typical usage on the transmit path:
2342 *
2343 * 		::
2344 *
2345 * 			struct bpf_tunnel_key key;
2346 * 			     populate key ...
2347 * 			bpf_skb_set_tunnel_key(skb, &key, sizeof(key), 0);
2348 * 			bpf_clone_redirect(skb, vxlan_dev_ifindex, 0);
2349 *
2350 * 		See also the description of the **bpf_skb_get_tunnel_key**\ ()
2351 * 		helper for additional information.
2352 * 	Return
2353 * 		0 on success, or a negative error in case of failure.
2354 *
2355 * u64 bpf_perf_event_read(struct bpf_map *map, u64 flags)
2356 * 	Description
2357 * 		Read the value of a perf event counter. This helper relies on a
2358 * 		*map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of
2359 * 		the perf event counter is selected when *map* is updated with
2360 * 		perf event file descriptors. The *map* is an array whose size
2361 * 		is the number of available CPUs, and each cell contains a value
2362 * 		relative to one CPU. The value to retrieve is indicated by
2363 * 		*flags*, that contains the index of the CPU to look up, masked
2364 * 		with **BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to
2365 * 		**BPF_F_CURRENT_CPU** to indicate that the value for the
2366 * 		current CPU should be retrieved.
2367 *
2368 * 		Note that before Linux 4.13, only hardware perf event can be
2369 * 		retrieved.
2370 *
2371 * 		Also, be aware that the newer helper
2372 * 		**bpf_perf_event_read_value**\ () is recommended over
2373 * 		**bpf_perf_event_read**\ () in general. The latter has some ABI
2374 * 		quirks where error and counter value are used as a return code
2375 * 		(which is wrong to do since ranges may overlap). This issue is
2376 * 		fixed with **bpf_perf_event_read_value**\ (), which at the same
2377 * 		time provides more features over the **bpf_perf_event_read**\
2378 * 		() interface. Please refer to the description of
2379 * 		**bpf_perf_event_read_value**\ () for details.
2380 * 	Return
2381 * 		The value of the perf event counter read from the map, or a
2382 * 		negative error code in case of failure.
2383 *
2384 * long bpf_redirect(u32 ifindex, u64 flags)
2385 * 	Description
2386 * 		Redirect the packet to another net device of index *ifindex*.
2387 * 		This helper is somewhat similar to **bpf_clone_redirect**\
2388 * 		(), except that the packet is not cloned, which provides
2389 * 		increased performance.
2390 *
2391 * 		Except for XDP, both ingress and egress interfaces can be used
2392 * 		for redirection. The **BPF_F_INGRESS** value in *flags* is used
2393 * 		to make the distinction (ingress path is selected if the flag
2394 * 		is present, egress path otherwise). Currently, XDP only
2395 * 		supports redirection to the egress interface, and accepts no
2396 * 		flag at all.
2397 *
2398 * 		The same effect can also be attained with the more generic
2399 * 		**bpf_redirect_map**\ (), which uses a BPF map to store the
2400 * 		redirect target instead of providing it directly to the helper.
2401 * 	Return
2402 * 		For XDP, the helper returns **XDP_REDIRECT** on success or
2403 * 		**XDP_ABORTED** on error. For other program types, the values
2404 * 		are **TC_ACT_REDIRECT** on success or **TC_ACT_SHOT** on
2405 * 		error.
2406 *
2407 * u32 bpf_get_route_realm(struct sk_buff *skb)
2408 * 	Description
2409 * 		Retrieve the realm or the route, that is to say the
2410 * 		**tclassid** field of the destination for the *skb*. The
2411 * 		identifier retrieved is a user-provided tag, similar to the
2412 * 		one used with the net_cls cgroup (see description for
2413 * 		**bpf_get_cgroup_classid**\ () helper), but here this tag is
2414 * 		held by a route (a destination entry), not by a task.
2415 *
2416 * 		Retrieving this identifier works with the clsact TC egress hook
2417 * 		(see also **tc-bpf(8)**), or alternatively on conventional
2418 * 		classful egress qdiscs, but not on TC ingress path. In case of
2419 * 		clsact TC egress hook, this has the advantage that, internally,
2420 * 		the destination entry has not been dropped yet in the transmit
2421 * 		path. Therefore, the destination entry does not need to be
2422 * 		artificially held via **netif_keep_dst**\ () for a classful
2423 * 		qdisc until the *skb* is freed.
2424 *
2425 * 		This helper is available only if the kernel was compiled with
2426 * 		**CONFIG_IP_ROUTE_CLASSID** configuration option.
2427 * 	Return
2428 * 		The realm of the route for the packet associated to *skb*, or 0
2429 * 		if none was found.
2430 *
2431 * long bpf_perf_event_output(void *ctx, struct bpf_map *map, u64 flags, void *data, u64 size)
2432 * 	Description
2433 * 		Write raw *data* blob into a special BPF perf event held by
2434 * 		*map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf
2435 * 		event must have the following attributes: **PERF_SAMPLE_RAW**
2436 * 		as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and
2437 * 		**PERF_COUNT_SW_BPF_OUTPUT** as **config**.
2438 *
2439 * 		The *flags* are used to indicate the index in *map* for which
2440 * 		the value must be put, masked with **BPF_F_INDEX_MASK**.
2441 * 		Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU**
2442 * 		to indicate that the index of the current CPU core should be
2443 * 		used.
2444 *
2445 * 		The value to write, of *size*, is passed through eBPF stack and
2446 * 		pointed by *data*.
2447 *
2448 * 		The context of the program *ctx* needs also be passed to the
2449 * 		helper.
2450 *
2451 * 		On user space, a program willing to read the values needs to
2452 * 		call **perf_event_open**\ () on the perf event (either for
2453 * 		one or for all CPUs) and to store the file descriptor into the
2454 * 		*map*. This must be done before the eBPF program can send data
2455 * 		into it. An example is available in file
2456 * 		*samples/bpf/trace_output_user.c* in the Linux kernel source
2457 * 		tree (the eBPF program counterpart is in
2458 *		*samples/bpf/trace_output.bpf.c*).
2459 *
2460 * 		**bpf_perf_event_output**\ () achieves better performance
2461 * 		than **bpf_trace_printk**\ () for sharing data with user
2462 * 		space, and is much better suitable for streaming data from eBPF
2463 * 		programs.
2464 *
2465 * 		Note that this helper is not restricted to tracing use cases
2466 * 		and can be used with programs attached to TC or XDP as well,
2467 * 		where it allows for passing data to user space listeners. Data
2468 * 		can be:
2469 *
2470 * 		* Only custom structs,
2471 * 		* Only the packet payload, or
2472 * 		* A combination of both.
2473 * 	Return
2474 * 		0 on success, or a negative error in case of failure.
2475 *
2476 * long bpf_skb_load_bytes(const void *skb, u32 offset, void *to, u32 len)
2477 * 	Description
2478 * 		This helper was provided as an easy way to load data from a
2479 * 		packet. It can be used to load *len* bytes from *offset* from
2480 * 		the packet associated to *skb*, into the buffer pointed by
2481 * 		*to*.
2482 *
2483 * 		Since Linux 4.7, usage of this helper has mostly been replaced
2484 * 		by "direct packet access", enabling packet data to be
2485 * 		manipulated with *skb*\ **->data** and *skb*\ **->data_end**
2486 * 		pointing respectively to the first byte of packet data and to
2487 * 		the byte after the last byte of packet data. However, it
2488 * 		remains useful if one wishes to read large quantities of data
2489 * 		at once from a packet into the eBPF stack.
2490 * 	Return
2491 * 		0 on success, or a negative error in case of failure.
2492 *
2493 * long bpf_get_stackid(void *ctx, struct bpf_map *map, u64 flags)
2494 * 	Description
2495 * 		Walk a user or a kernel stack and return its id. To achieve
2496 * 		this, the helper needs *ctx*, which is a pointer to the context
2497 * 		on which the tracing program is executed, and a pointer to a
2498 * 		*map* of type **BPF_MAP_TYPE_STACK_TRACE**.
2499 *
2500 * 		The last argument, *flags*, holds the number of stack frames to
2501 * 		skip (from 0 to 255), masked with
2502 * 		**BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set
2503 * 		a combination of the following flags:
2504 *
2505 * 		**BPF_F_USER_STACK**
2506 * 			Collect a user space stack instead of a kernel stack.
2507 * 		**BPF_F_FAST_STACK_CMP**
2508 * 			Compare stacks by hash only.
2509 * 		**BPF_F_REUSE_STACKID**
2510 * 			If two different stacks hash into the same *stackid*,
2511 * 			discard the old one.
2512 *
2513 * 		The stack id retrieved is a 32 bit long integer handle which
2514 * 		can be further combined with other data (including other stack
2515 * 		ids) and used as a key into maps. This can be useful for
2516 * 		generating a variety of graphs (such as flame graphs or off-cpu
2517 * 		graphs).
2518 *
2519 * 		For walking a stack, this helper is an improvement over
2520 * 		**bpf_probe_read**\ (), which can be used with unrolled loops
2521 * 		but is not efficient and consumes a lot of eBPF instructions.
2522 * 		Instead, **bpf_get_stackid**\ () can collect up to
2523 * 		**PERF_MAX_STACK_DEPTH** both kernel and user frames. Note that
2524 * 		this limit can be controlled with the **sysctl** program, and
2525 * 		that it should be manually increased in order to profile long
2526 * 		user stacks (such as stacks for Java programs). To do so, use:
2527 *
2528 * 		::
2529 *
2530 * 			# sysctl kernel.perf_event_max_stack=<new value>
2531 * 	Return
2532 * 		The positive or null stack id on success, or a negative error
2533 * 		in case of failure.
2534 *
2535 * s64 bpf_csum_diff(__be32 *from, u32 from_size, __be32 *to, u32 to_size, __wsum seed)
2536 * 	Description
2537 * 		Compute a checksum difference, from the raw buffer pointed by
2538 * 		*from*, of length *from_size* (that must be a multiple of 4),
2539 * 		towards the raw buffer pointed by *to*, of size *to_size*
2540 * 		(same remark). An optional *seed* can be added to the value
2541 * 		(this can be cascaded, the seed may come from a previous call
2542 * 		to the helper).
2543 *
2544 * 		This is flexible enough to be used in several ways:
2545 *
2546 * 		* With *from_size* == 0, *to_size* > 0 and *seed* set to
2547 * 		  checksum, it can be used when pushing new data.
2548 * 		* With *from_size* > 0, *to_size* == 0 and *seed* set to
2549 * 		  checksum, it can be used when removing data from a packet.
2550 * 		* With *from_size* > 0, *to_size* > 0 and *seed* set to 0, it
2551 * 		  can be used to compute a diff. Note that *from_size* and
2552 * 		  *to_size* do not need to be equal.
2553 *
2554 * 		This helper can be used in combination with
2555 * 		**bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\ (), to
2556 * 		which one can feed in the difference computed with
2557 * 		**bpf_csum_diff**\ ().
2558 * 	Return
2559 * 		The checksum result, or a negative error code in case of
2560 * 		failure.
2561 *
2562 * long bpf_skb_get_tunnel_opt(struct sk_buff *skb, void *opt, u32 size)
2563 * 	Description
2564 * 		Retrieve tunnel options metadata for the packet associated to
2565 * 		*skb*, and store the raw tunnel option data to the buffer *opt*
2566 * 		of *size*.
2567 *
2568 * 		This helper can be used with encapsulation devices that can
2569 * 		operate in "collect metadata" mode (please refer to the related
2570 * 		note in the description of **bpf_skb_get_tunnel_key**\ () for
2571 * 		more details). A particular example where this can be used is
2572 * 		in combination with the Geneve encapsulation protocol, where it
2573 * 		allows for pushing (with **bpf_skb_get_tunnel_opt**\ () helper)
2574 * 		and retrieving arbitrary TLVs (Type-Length-Value headers) from
2575 * 		the eBPF program. This allows for full customization of these
2576 * 		headers.
2577 * 	Return
2578 * 		The size of the option data retrieved.
2579 *
2580 * long bpf_skb_set_tunnel_opt(struct sk_buff *skb, void *opt, u32 size)
2581 * 	Description
2582 * 		Set tunnel options metadata for the packet associated to *skb*
2583 * 		to the option data contained in the raw buffer *opt* of *size*.
2584 *
2585 * 		See also the description of the **bpf_skb_get_tunnel_opt**\ ()
2586 * 		helper for additional information.
2587 * 	Return
2588 * 		0 on success, or a negative error in case of failure.
2589 *
2590 * long bpf_skb_change_proto(struct sk_buff *skb, __be16 proto, u64 flags)
2591 * 	Description
2592 * 		Change the protocol of the *skb* to *proto*. Currently
2593 * 		supported are transition from IPv4 to IPv6, and from IPv6 to
2594 * 		IPv4. The helper takes care of the groundwork for the
2595 * 		transition, including resizing the socket buffer. The eBPF
2596 * 		program is expected to fill the new headers, if any, via
2597 * 		**skb_store_bytes**\ () and to recompute the checksums with
2598 * 		**bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\
2599 * 		(). The main case for this helper is to perform NAT64
2600 * 		operations out of an eBPF program.
2601 *
2602 * 		Internally, the GSO type is marked as dodgy so that headers are
2603 * 		checked and segments are recalculated by the GSO/GRO engine.
2604 * 		The size for GSO target is adapted as well.
2605 *
2606 * 		All values for *flags* are reserved for future usage, and must
2607 * 		be left at zero.
2608 *
2609 * 		A call to this helper is susceptible to change the underlying
2610 * 		packet buffer. Therefore, at load time, all checks on pointers
2611 * 		previously done by the verifier are invalidated and must be
2612 * 		performed again, if the helper is used in combination with
2613 * 		direct packet access.
2614 * 	Return
2615 * 		0 on success, or a negative error in case of failure.
2616 *
2617 * long bpf_skb_change_type(struct sk_buff *skb, u32 type)
2618 * 	Description
2619 * 		Change the packet type for the packet associated to *skb*. This
2620 * 		comes down to setting *skb*\ **->pkt_type** to *type*, except
2621 * 		the eBPF program does not have a write access to *skb*\
2622 * 		**->pkt_type** beside this helper. Using a helper here allows
2623 * 		for graceful handling of errors.
2624 *
2625 * 		The major use case is to change incoming *skb*s to
2626 * 		**PACKET_HOST** in a programmatic way instead of having to
2627 * 		recirculate via **redirect**\ (..., **BPF_F_INGRESS**), for
2628 * 		example.
2629 *
2630 * 		Note that *type* only allows certain values. At this time, they
2631 * 		are:
2632 *
2633 * 		**PACKET_HOST**
2634 * 			Packet is for us.
2635 * 		**PACKET_BROADCAST**
2636 * 			Send packet to all.
2637 * 		**PACKET_MULTICAST**
2638 * 			Send packet to group.
2639 * 		**PACKET_OTHERHOST**
2640 * 			Send packet to someone else.
2641 * 	Return
2642 * 		0 on success, or a negative error in case of failure.
2643 *
2644 * long bpf_skb_under_cgroup(struct sk_buff *skb, struct bpf_map *map, u32 index)
2645 * 	Description
2646 * 		Check whether *skb* is a descendant of the cgroup2 held by
2647 * 		*map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*.
2648 * 	Return
2649 * 		The return value depends on the result of the test, and can be:
2650 *
2651 * 		* 0, if the *skb* failed the cgroup2 descendant test.
2652 * 		* 1, if the *skb* succeeded the cgroup2 descendant test.
2653 * 		* A negative error code, if an error occurred.
2654 *
2655 * u32 bpf_get_hash_recalc(struct sk_buff *skb)
2656 * 	Description
2657 * 		Retrieve the hash of the packet, *skb*\ **->hash**. If it is
2658 * 		not set, in particular if the hash was cleared due to mangling,
2659 * 		recompute this hash. Later accesses to the hash can be done
2660 * 		directly with *skb*\ **->hash**.
2661 *
2662 * 		Calling **bpf_set_hash_invalid**\ (), changing a packet
2663 * 		prototype with **bpf_skb_change_proto**\ (), or calling
2664 * 		**bpf_skb_store_bytes**\ () with the
2665 * 		**BPF_F_INVALIDATE_HASH** are actions susceptible to clear
2666 * 		the hash and to trigger a new computation for the next call to
2667 * 		**bpf_get_hash_recalc**\ ().
2668 * 	Return
2669 * 		The 32-bit hash.
2670 *
2671 * u64 bpf_get_current_task(void)
2672 * 	Description
2673 * 		Get the current task.
2674 * 	Return
2675 * 		A pointer to the current task struct.
2676 *
2677 * long bpf_probe_write_user(void *dst, const void *src, u32 len)
2678 * 	Description
2679 * 		Attempt in a safe way to write *len* bytes from the buffer
2680 * 		*src* to *dst* in memory. It only works for threads that are in
2681 * 		user context, and *dst* must be a valid user space address.
2682 *
2683 * 		This helper should not be used to implement any kind of
2684 * 		security mechanism because of TOC-TOU attacks, but rather to
2685 * 		debug, divert, and manipulate execution of semi-cooperative
2686 * 		processes.
2687 *
2688 * 		Keep in mind that this feature is meant for experiments, and it
2689 * 		has a risk of crashing the system and running programs.
2690 * 		Therefore, when an eBPF program using this helper is attached,
2691 * 		a warning including PID and process name is printed to kernel
2692 * 		logs.
2693 * 	Return
2694 * 		0 on success, or a negative error in case of failure.
2695 *
2696 * long bpf_current_task_under_cgroup(struct bpf_map *map, u32 index)
2697 * 	Description
2698 * 		Check whether the probe is being run is the context of a given
2699 * 		subset of the cgroup2 hierarchy. The cgroup2 to test is held by
2700 * 		*map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*.
2701 * 	Return
2702 * 		The return value depends on the result of the test, and can be:
2703 *
2704 *		* 1, if current task belongs to the cgroup2.
2705 *		* 0, if current task does not belong to the cgroup2.
2706 * 		* A negative error code, if an error occurred.
2707 *
2708 * long bpf_skb_change_tail(struct sk_buff *skb, u32 len, u64 flags)
2709 * 	Description
2710 * 		Resize (trim or grow) the packet associated to *skb* to the
2711 * 		new *len*. The *flags* are reserved for future usage, and must
2712 * 		be left at zero.
2713 *
2714 * 		The basic idea is that the helper performs the needed work to
2715 * 		change the size of the packet, then the eBPF program rewrites
2716 * 		the rest via helpers like **bpf_skb_store_bytes**\ (),
2717 * 		**bpf_l3_csum_replace**\ (), **bpf_l3_csum_replace**\ ()
2718 * 		and others. This helper is a slow path utility intended for
2719 * 		replies with control messages. And because it is targeted for
2720 * 		slow path, the helper itself can afford to be slow: it
2721 * 		implicitly linearizes, unclones and drops offloads from the
2722 * 		*skb*.
2723 *
2724 * 		A call to this helper is susceptible to change the underlying
2725 * 		packet buffer. Therefore, at load time, all checks on pointers
2726 * 		previously done by the verifier are invalidated and must be
2727 * 		performed again, if the helper is used in combination with
2728 * 		direct packet access.
2729 * 	Return
2730 * 		0 on success, or a negative error in case of failure.
2731 *
2732 * long bpf_skb_pull_data(struct sk_buff *skb, u32 len)
2733 * 	Description
2734 * 		Pull in non-linear data in case the *skb* is non-linear and not
2735 * 		all of *len* are part of the linear section. Make *len* bytes
2736 * 		from *skb* readable and writable. If a zero value is passed for
2737 *		*len*, then all bytes in the linear part of *skb* will be made
2738 *		readable and writable.
2739 *
2740 * 		This helper is only needed for reading and writing with direct
2741 * 		packet access.
2742 *
2743 * 		For direct packet access, testing that offsets to access
2744 * 		are within packet boundaries (test on *skb*\ **->data_end**) is
2745 * 		susceptible to fail if offsets are invalid, or if the requested
2746 * 		data is in non-linear parts of the *skb*. On failure the
2747 * 		program can just bail out, or in the case of a non-linear
2748 * 		buffer, use a helper to make the data available. The
2749 * 		**bpf_skb_load_bytes**\ () helper is a first solution to access
2750 * 		the data. Another one consists in using **bpf_skb_pull_data**
2751 * 		to pull in once the non-linear parts, then retesting and
2752 * 		eventually access the data.
2753 *
2754 * 		At the same time, this also makes sure the *skb* is uncloned,
2755 * 		which is a necessary condition for direct write. As this needs
2756 * 		to be an invariant for the write part only, the verifier
2757 * 		detects writes and adds a prologue that is calling
2758 * 		**bpf_skb_pull_data()** to effectively unclone the *skb* from
2759 * 		the very beginning in case it is indeed cloned.
2760 *
2761 * 		A call to this helper is susceptible to change the underlying
2762 * 		packet buffer. Therefore, at load time, all checks on pointers
2763 * 		previously done by the verifier are invalidated and must be
2764 * 		performed again, if the helper is used in combination with
2765 * 		direct packet access.
2766 * 	Return
2767 * 		0 on success, or a negative error in case of failure.
2768 *
2769 * s64 bpf_csum_update(struct sk_buff *skb, __wsum csum)
2770 * 	Description
2771 * 		Add the checksum *csum* into *skb*\ **->csum** in case the
2772 * 		driver has supplied a checksum for the entire packet into that
2773 * 		field. Return an error otherwise. This helper is intended to be
2774 * 		used in combination with **bpf_csum_diff**\ (), in particular
2775 * 		when the checksum needs to be updated after data has been
2776 * 		written into the packet through direct packet access.
2777 * 	Return
2778 * 		The checksum on success, or a negative error code in case of
2779 * 		failure.
2780 *
2781 * void bpf_set_hash_invalid(struct sk_buff *skb)
2782 * 	Description
2783 * 		Invalidate the current *skb*\ **->hash**. It can be used after
2784 * 		mangling on headers through direct packet access, in order to
2785 * 		indicate that the hash is outdated and to trigger a
2786 * 		recalculation the next time the kernel tries to access this
2787 * 		hash or when the **bpf_get_hash_recalc**\ () helper is called.
2788 * 	Return
2789 * 		void.
2790 *
2791 * long bpf_get_numa_node_id(void)
2792 * 	Description
2793 * 		Return the id of the current NUMA node. The primary use case
2794 * 		for this helper is the selection of sockets for the local NUMA
2795 * 		node, when the program is attached to sockets using the
2796 * 		**SO_ATTACH_REUSEPORT_EBPF** option (see also **socket(7)**),
2797 * 		but the helper is also available to other eBPF program types,
2798 * 		similarly to **bpf_get_smp_processor_id**\ ().
2799 * 	Return
2800 * 		The id of current NUMA node.
2801 *
2802 * long bpf_skb_change_head(struct sk_buff *skb, u32 len, u64 flags)
2803 * 	Description
2804 * 		Grows headroom of packet associated to *skb* and adjusts the
2805 * 		offset of the MAC header accordingly, adding *len* bytes of
2806 * 		space. It automatically extends and reallocates memory as
2807 * 		required.
2808 *
2809 * 		This helper can be used on a layer 3 *skb* to push a MAC header
2810 * 		for redirection into a layer 2 device.
2811 *
2812 * 		All values for *flags* are reserved for future usage, and must
2813 * 		be left at zero.
2814 *
2815 * 		A call to this helper is susceptible to change the underlying
2816 * 		packet buffer. Therefore, at load time, all checks on pointers
2817 * 		previously done by the verifier are invalidated and must be
2818 * 		performed again, if the helper is used in combination with
2819 * 		direct packet access.
2820 * 	Return
2821 * 		0 on success, or a negative error in case of failure.
2822 *
2823 * long bpf_xdp_adjust_head(struct xdp_buff *xdp_md, int delta)
2824 * 	Description
2825 * 		Adjust (move) *xdp_md*\ **->data** by *delta* bytes. Note that
2826 * 		it is possible to use a negative value for *delta*. This helper
2827 * 		can be used to prepare the packet for pushing or popping
2828 * 		headers.
2829 *
2830 * 		A call to this helper is susceptible to change the underlying
2831 * 		packet buffer. Therefore, at load time, all checks on pointers
2832 * 		previously done by the verifier are invalidated and must be
2833 * 		performed again, if the helper is used in combination with
2834 * 		direct packet access.
2835 * 	Return
2836 * 		0 on success, or a negative error in case of failure.
2837 *
2838 * long bpf_probe_read_str(void *dst, u32 size, const void *unsafe_ptr)
2839 * 	Description
2840 * 		Copy a NUL terminated string from an unsafe kernel address
2841 * 		*unsafe_ptr* to *dst*. See **bpf_probe_read_kernel_str**\ () for
2842 * 		more details.
2843 *
2844 * 		Generally, use **bpf_probe_read_user_str**\ () or
2845 * 		**bpf_probe_read_kernel_str**\ () instead.
2846 * 	Return
2847 * 		On success, the strictly positive length of the string,
2848 * 		including the trailing NUL character. On error, a negative
2849 * 		value.
2850 *
2851 * u64 bpf_get_socket_cookie(struct sk_buff *skb)
2852 * 	Description
2853 * 		If the **struct sk_buff** pointed by *skb* has a known socket,
2854 * 		retrieve the cookie (generated by the kernel) of this socket.
2855 * 		If no cookie has been set yet, generate a new cookie. Once
2856 * 		generated, the socket cookie remains stable for the life of the
2857 * 		socket. This helper can be useful for monitoring per socket
2858 * 		networking traffic statistics as it provides a global socket
2859 * 		identifier that can be assumed unique.
2860 * 	Return
2861 * 		A 8-byte long unique number on success, or 0 if the socket
2862 * 		field is missing inside *skb*.
2863 *
2864 * u64 bpf_get_socket_cookie(struct bpf_sock_addr *ctx)
2865 * 	Description
2866 * 		Equivalent to bpf_get_socket_cookie() helper that accepts
2867 * 		*skb*, but gets socket from **struct bpf_sock_addr** context.
2868 * 	Return
2869 * 		A 8-byte long unique number.
2870 *
2871 * u64 bpf_get_socket_cookie(struct bpf_sock_ops *ctx)
2872 * 	Description
2873 * 		Equivalent to **bpf_get_socket_cookie**\ () helper that accepts
2874 * 		*skb*, but gets socket from **struct bpf_sock_ops** context.
2875 * 	Return
2876 * 		A 8-byte long unique number.
2877 *
2878 * u64 bpf_get_socket_cookie(struct sock *sk)
2879 * 	Description
2880 * 		Equivalent to **bpf_get_socket_cookie**\ () helper that accepts
2881 * 		*sk*, but gets socket from a BTF **struct sock**. This helper
2882 * 		also works for sleepable programs.
2883 * 	Return
2884 * 		A 8-byte long unique number or 0 if *sk* is NULL.
2885 *
2886 * u32 bpf_get_socket_uid(struct sk_buff *skb)
2887 * 	Description
2888 * 		Get the owner UID of the socked associated to *skb*.
2889 * 	Return
2890 * 		The owner UID of the socket associated to *skb*. If the socket
2891 * 		is **NULL**, or if it is not a full socket (i.e. if it is a
2892 * 		time-wait or a request socket instead), **overflowuid** value
2893 * 		is returned (note that **overflowuid** might also be the actual
2894 * 		UID value for the socket).
2895 *
2896 * long bpf_set_hash(struct sk_buff *skb, u32 hash)
2897 * 	Description
2898 * 		Set the full hash for *skb* (set the field *skb*\ **->hash**)
2899 * 		to value *hash*.
2900 * 	Return
2901 * 		0
2902 *
2903 * long bpf_setsockopt(void *bpf_socket, int level, int optname, void *optval, int optlen)
2904 * 	Description
2905 * 		Emulate a call to **setsockopt()** on the socket associated to
2906 * 		*bpf_socket*, which must be a full socket. The *level* at
2907 * 		which the option resides and the name *optname* of the option
2908 * 		must be specified, see **setsockopt(2)** for more information.
2909 * 		The option value of length *optlen* is pointed by *optval*.
2910 *
2911 * 		*bpf_socket* should be one of the following:
2912 *
2913 * 		* **struct bpf_sock_ops** for **BPF_PROG_TYPE_SOCK_OPS**.
2914 *		* **struct bpf_sock_addr** for **BPF_CGROUP_INET4_CONNECT**,
2915 *		  **BPF_CGROUP_INET6_CONNECT** and **BPF_CGROUP_UNIX_CONNECT**.
2916 *
2917 * 		This helper actually implements a subset of **setsockopt()**.
2918 * 		It supports the following *level*\ s:
2919 *
2920 * 		* **SOL_SOCKET**, which supports the following *optname*\ s:
2921 * 		  **SO_RCVBUF**, **SO_SNDBUF**, **SO_MAX_PACING_RATE**,
2922 * 		  **SO_PRIORITY**, **SO_RCVLOWAT**, **SO_MARK**,
2923 * 		  **SO_BINDTODEVICE**, **SO_KEEPALIVE**, **SO_REUSEADDR**,
2924 * 		  **SO_REUSEPORT**, **SO_BINDTOIFINDEX**, **SO_TXREHASH**.
2925 * 		* **IPPROTO_TCP**, which supports the following *optname*\ s:
2926 * 		  **TCP_CONGESTION**, **TCP_BPF_IW**,
2927 * 		  **TCP_BPF_SNDCWND_CLAMP**, **TCP_SAVE_SYN**,
2928 * 		  **TCP_KEEPIDLE**, **TCP_KEEPINTVL**, **TCP_KEEPCNT**,
2929 * 		  **TCP_SYNCNT**, **TCP_USER_TIMEOUT**, **TCP_NOTSENT_LOWAT**,
2930 * 		  **TCP_NODELAY**, **TCP_MAXSEG**, **TCP_WINDOW_CLAMP**,
2931 * 		  **TCP_THIN_LINEAR_TIMEOUTS**, **TCP_BPF_DELACK_MAX**,
2932 *		  **TCP_BPF_RTO_MIN**, **TCP_BPF_SOCK_OPS_CB_FLAGS**.
2933 * 		* **IPPROTO_IP**, which supports *optname* **IP_TOS**.
2934 * 		* **IPPROTO_IPV6**, which supports the following *optname*\ s:
2935 * 		  **IPV6_TCLASS**, **IPV6_AUTOFLOWLABEL**.
2936 * 	Return
2937 * 		0 on success, or a negative error in case of failure.
2938 *
2939 * long bpf_skb_adjust_room(struct sk_buff *skb, s32 len_diff, u32 mode, u64 flags)
2940 * 	Description
2941 * 		Grow or shrink the room for data in the packet associated to
2942 * 		*skb* by *len_diff*, and according to the selected *mode*.
2943 *
2944 * 		By default, the helper will reset any offloaded checksum
2945 * 		indicator of the skb to CHECKSUM_NONE. This can be avoided
2946 * 		by the following flag:
2947 *
2948 * 		* **BPF_F_ADJ_ROOM_NO_CSUM_RESET**: Do not reset offloaded
2949 * 		  checksum data of the skb to CHECKSUM_NONE.
2950 *
2951 *		There are two supported modes at this time:
2952 *
2953 *		* **BPF_ADJ_ROOM_MAC**: Adjust room at the mac layer
2954 * 		  (room space is added or removed between the layer 2 and
2955 * 		  layer 3 headers).
2956 *
2957 * 		* **BPF_ADJ_ROOM_NET**: Adjust room at the network layer
2958 * 		  (room space is added or removed between the layer 3 and
2959 * 		  layer 4 headers).
2960 *
2961 *		The following flags are supported at this time:
2962 *
2963 *		* **BPF_F_ADJ_ROOM_FIXED_GSO**: Do not adjust gso_size.
2964 *		  Adjusting mss in this way is not allowed for datagrams.
2965 *
2966 *		* **BPF_F_ADJ_ROOM_ENCAP_L3_IPV4**,
2967 *		  **BPF_F_ADJ_ROOM_ENCAP_L3_IPV6**:
2968 *		  Any new space is reserved to hold a tunnel header.
2969 *		  Configure skb offsets and other fields accordingly.
2970 *
2971 *		* **BPF_F_ADJ_ROOM_ENCAP_L4_GRE**,
2972 *		  **BPF_F_ADJ_ROOM_ENCAP_L4_UDP**:
2973 *		  Use with ENCAP_L3 flags to further specify the tunnel type.
2974 *
2975 *		* **BPF_F_ADJ_ROOM_ENCAP_L2**\ (*len*):
2976 *		  Use with ENCAP_L3/L4 flags to further specify the tunnel
2977 *		  type; *len* is the length of the inner MAC header.
2978 *
2979 *		* **BPF_F_ADJ_ROOM_ENCAP_L2_ETH**:
2980 *		  Use with BPF_F_ADJ_ROOM_ENCAP_L2 flag to further specify the
2981 *		  L2 type as Ethernet.
2982 *
2983 *		* **BPF_F_ADJ_ROOM_DECAP_L3_IPV4**,
2984 *		  **BPF_F_ADJ_ROOM_DECAP_L3_IPV6**:
2985 *		  Indicate the new IP header version after decapsulating the outer
2986 *		  IP header. Used when the inner and outer IP versions are different.
2987 *
2988 * 		A call to this helper is susceptible to change the underlying
2989 * 		packet buffer. Therefore, at load time, all checks on pointers
2990 * 		previously done by the verifier are invalidated and must be
2991 * 		performed again, if the helper is used in combination with
2992 * 		direct packet access.
2993 * 	Return
2994 * 		0 on success, or a negative error in case of failure.
2995 *
2996 * long bpf_redirect_map(struct bpf_map *map, u64 key, u64 flags)
2997 * 	Description
2998 * 		Redirect the packet to the endpoint referenced by *map* at
2999 * 		index *key*. Depending on its type, this *map* can contain
3000 * 		references to net devices (for forwarding packets through other
3001 * 		ports), or to CPUs (for redirecting XDP frames to another CPU;
3002 * 		but this is only implemented for native XDP (with driver
3003 * 		support) as of this writing).
3004 *
3005 * 		The lower two bits of *flags* are used as the return code if
3006 * 		the map lookup fails. This is so that the return value can be
3007 * 		one of the XDP program return codes up to **XDP_TX**, as chosen
3008 * 		by the caller. The higher bits of *flags* can be set to
3009 * 		BPF_F_BROADCAST or BPF_F_EXCLUDE_INGRESS as defined below.
3010 *
3011 * 		With BPF_F_BROADCAST the packet will be broadcasted to all the
3012 * 		interfaces in the map, with BPF_F_EXCLUDE_INGRESS the ingress
3013 * 		interface will be excluded when do broadcasting.
3014 *
3015 * 		See also **bpf_redirect**\ (), which only supports redirecting
3016 * 		to an ifindex, but doesn't require a map to do so.
3017 * 	Return
3018 * 		**XDP_REDIRECT** on success, or the value of the two lower bits
3019 * 		of the *flags* argument on error.
3020 *
3021 * long bpf_sk_redirect_map(struct sk_buff *skb, struct bpf_map *map, u32 key, u64 flags)
3022 * 	Description
3023 * 		Redirect the packet to the socket referenced by *map* (of type
3024 * 		**BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and
3025 * 		egress interfaces can be used for redirection. The
3026 * 		**BPF_F_INGRESS** value in *flags* is used to make the
3027 * 		distinction (ingress path is selected if the flag is present,
3028 * 		egress path otherwise). This is the only flag supported for now.
3029 * 	Return
3030 * 		**SK_PASS** on success, or **SK_DROP** on error.
3031 *
3032 * long bpf_sock_map_update(struct bpf_sock_ops *skops, struct bpf_map *map, void *key, u64 flags)
3033 * 	Description
3034 * 		Add an entry to, or update a *map* referencing sockets. The
3035 * 		*skops* is used as a new value for the entry associated to
3036 * 		*key*. *flags* is one of:
3037 *
3038 * 		**BPF_NOEXIST**
3039 * 			The entry for *key* must not exist in the map.
3040 * 		**BPF_EXIST**
3041 * 			The entry for *key* must already exist in the map.
3042 * 		**BPF_ANY**
3043 * 			No condition on the existence of the entry for *key*.
3044 *
3045 * 		If the *map* has eBPF programs (parser and verdict), those will
3046 * 		be inherited by the socket being added. If the socket is
3047 * 		already attached to eBPF programs, this results in an error.
3048 * 	Return
3049 * 		0 on success, or a negative error in case of failure.
3050 *
3051 * long bpf_xdp_adjust_meta(struct xdp_buff *xdp_md, int delta)
3052 * 	Description
3053 * 		Adjust the address pointed by *xdp_md*\ **->data_meta** by
3054 * 		*delta* (which can be positive or negative). Note that this
3055 * 		operation modifies the address stored in *xdp_md*\ **->data**,
3056 * 		so the latter must be loaded only after the helper has been
3057 * 		called.
3058 *
3059 * 		The use of *xdp_md*\ **->data_meta** is optional and programs
3060 * 		are not required to use it. The rationale is that when the
3061 * 		packet is processed with XDP (e.g. as DoS filter), it is
3062 * 		possible to push further meta data along with it before passing
3063 * 		to the stack, and to give the guarantee that an ingress eBPF
3064 * 		program attached as a TC classifier on the same device can pick
3065 * 		this up for further post-processing. Since TC works with socket
3066 * 		buffers, it remains possible to set from XDP the **mark** or
3067 * 		**priority** pointers, or other pointers for the socket buffer.
3068 * 		Having this scratch space generic and programmable allows for
3069 * 		more flexibility as the user is free to store whatever meta
3070 * 		data they need.
3071 *
3072 * 		A call to this helper is susceptible to change the underlying
3073 * 		packet buffer. Therefore, at load time, all checks on pointers
3074 * 		previously done by the verifier are invalidated and must be
3075 * 		performed again, if the helper is used in combination with
3076 * 		direct packet access.
3077 * 	Return
3078 * 		0 on success, or a negative error in case of failure.
3079 *
3080 * long bpf_perf_event_read_value(struct bpf_map *map, u64 flags, struct bpf_perf_event_value *buf, u32 buf_size)
3081 * 	Description
3082 * 		Read the value of a perf event counter, and store it into *buf*
3083 * 		of size *buf_size*. This helper relies on a *map* of type
3084 * 		**BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of the perf event
3085 * 		counter is selected when *map* is updated with perf event file
3086 * 		descriptors. The *map* is an array whose size is the number of
3087 * 		available CPUs, and each cell contains a value relative to one
3088 * 		CPU. The value to retrieve is indicated by *flags*, that
3089 * 		contains the index of the CPU to look up, masked with
3090 * 		**BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to
3091 * 		**BPF_F_CURRENT_CPU** to indicate that the value for the
3092 * 		current CPU should be retrieved.
3093 *
3094 * 		This helper behaves in a way close to
3095 * 		**bpf_perf_event_read**\ () helper, save that instead of
3096 * 		just returning the value observed, it fills the *buf*
3097 * 		structure. This allows for additional data to be retrieved: in
3098 * 		particular, the enabled and running times (in *buf*\
3099 * 		**->enabled** and *buf*\ **->running**, respectively) are
3100 * 		copied. In general, **bpf_perf_event_read_value**\ () is
3101 * 		recommended over **bpf_perf_event_read**\ (), which has some
3102 * 		ABI issues and provides fewer functionalities.
3103 *
3104 * 		These values are interesting, because hardware PMU (Performance
3105 * 		Monitoring Unit) counters are limited resources. When there are
3106 * 		more PMU based perf events opened than available counters,
3107 * 		kernel will multiplex these events so each event gets certain
3108 * 		percentage (but not all) of the PMU time. In case that
3109 * 		multiplexing happens, the number of samples or counter value
3110 * 		will not reflect the case compared to when no multiplexing
3111 * 		occurs. This makes comparison between different runs difficult.
3112 * 		Typically, the counter value should be normalized before
3113 * 		comparing to other experiments. The usual normalization is done
3114 * 		as follows.
3115 *
3116 * 		::
3117 *
3118 * 			normalized_counter = counter * t_enabled / t_running
3119 *
3120 * 		Where t_enabled is the time enabled for event and t_running is
3121 * 		the time running for event since last normalization. The
3122 * 		enabled and running times are accumulated since the perf event
3123 * 		open. To achieve scaling factor between two invocations of an
3124 * 		eBPF program, users can use CPU id as the key (which is
3125 * 		typical for perf array usage model) to remember the previous
3126 * 		value and do the calculation inside the eBPF program.
3127 * 	Return
3128 * 		0 on success, or a negative error in case of failure.
3129 *
3130 * long bpf_perf_prog_read_value(struct bpf_perf_event_data *ctx, struct bpf_perf_event_value *buf, u32 buf_size)
3131 * 	Description
3132 * 		For an eBPF program attached to a perf event, retrieve the
3133 * 		value of the event counter associated to *ctx* and store it in
3134 * 		the structure pointed by *buf* and of size *buf_size*. Enabled
3135 * 		and running times are also stored in the structure (see
3136 * 		description of helper **bpf_perf_event_read_value**\ () for
3137 * 		more details).
3138 * 	Return
3139 * 		0 on success, or a negative error in case of failure.
3140 *
3141 * long bpf_getsockopt(void *bpf_socket, int level, int optname, void *optval, int optlen)
3142 * 	Description
3143 * 		Emulate a call to **getsockopt()** on the socket associated to
3144 * 		*bpf_socket*, which must be a full socket. The *level* at
3145 * 		which the option resides and the name *optname* of the option
3146 * 		must be specified, see **getsockopt(2)** for more information.
3147 * 		The retrieved value is stored in the structure pointed by
3148 * 		*opval* and of length *optlen*.
3149 *
3150 * 		*bpf_socket* should be one of the following:
3151 *
3152 * 		* **struct bpf_sock_ops** for **BPF_PROG_TYPE_SOCK_OPS**.
3153 *		* **struct bpf_sock_addr** for **BPF_CGROUP_INET4_CONNECT**,
3154 *		  **BPF_CGROUP_INET6_CONNECT** and **BPF_CGROUP_UNIX_CONNECT**.
3155 *
3156 * 		This helper actually implements a subset of **getsockopt()**.
3157 * 		It supports the same set of *optname*\ s that is supported by
3158 * 		the **bpf_setsockopt**\ () helper.  The exceptions are
3159 * 		**TCP_BPF_*** is **bpf_setsockopt**\ () only and
3160 * 		**TCP_SAVED_SYN** is **bpf_getsockopt**\ () only.
3161 * 	Return
3162 * 		0 on success, or a negative error in case of failure.
3163 *
3164 * long bpf_override_return(struct pt_regs *regs, u64 rc)
3165 * 	Description
3166 * 		Used for error injection, this helper uses kprobes to override
3167 * 		the return value of the probed function, and to set it to *rc*.
3168 * 		The first argument is the context *regs* on which the kprobe
3169 * 		works.
3170 *
3171 * 		This helper works by setting the PC (program counter)
3172 * 		to an override function which is run in place of the original
3173 * 		probed function. This means the probed function is not run at
3174 * 		all. The replacement function just returns with the required
3175 * 		value.
3176 *
3177 * 		This helper has security implications, and thus is subject to
3178 * 		restrictions. It is only available if the kernel was compiled
3179 * 		with the **CONFIG_BPF_KPROBE_OVERRIDE** configuration
3180 * 		option, and in this case it only works on functions tagged with
3181 * 		**ALLOW_ERROR_INJECTION** in the kernel code.
3182 * 	Return
3183 * 		0
3184 *
3185 * long bpf_sock_ops_cb_flags_set(struct bpf_sock_ops *bpf_sock, int argval)
3186 * 	Description
3187 * 		Attempt to set the value of the **bpf_sock_ops_cb_flags** field
3188 * 		for the full TCP socket associated to *bpf_sock_ops* to
3189 * 		*argval*.
3190 *
3191 * 		The primary use of this field is to determine if there should
3192 * 		be calls to eBPF programs of type
3193 * 		**BPF_PROG_TYPE_SOCK_OPS** at various points in the TCP
3194 * 		code. A program of the same type can change its value, per
3195 * 		connection and as necessary, when the connection is
3196 * 		established. This field is directly accessible for reading, but
3197 * 		this helper must be used for updates in order to return an
3198 * 		error if an eBPF program tries to set a callback that is not
3199 * 		supported in the current kernel.
3200 *
3201 * 		*argval* is a flag array which can combine these flags:
3202 *
3203 * 		* **BPF_SOCK_OPS_RTO_CB_FLAG** (retransmission time out)
3204 * 		* **BPF_SOCK_OPS_RETRANS_CB_FLAG** (retransmission)
3205 * 		* **BPF_SOCK_OPS_STATE_CB_FLAG** (TCP state change)
3206 * 		* **BPF_SOCK_OPS_RTT_CB_FLAG** (every RTT)
3207 *
3208 * 		Therefore, this function can be used to clear a callback flag by
3209 * 		setting the appropriate bit to zero. e.g. to disable the RTO
3210 * 		callback:
3211 *
3212 * 		**bpf_sock_ops_cb_flags_set(bpf_sock,**
3213 * 			**bpf_sock->bpf_sock_ops_cb_flags & ~BPF_SOCK_OPS_RTO_CB_FLAG)**
3214 *
3215 * 		Here are some examples of where one could call such eBPF
3216 * 		program:
3217 *
3218 * 		* When RTO fires.
3219 * 		* When a packet is retransmitted.
3220 * 		* When the connection terminates.
3221 * 		* When a packet is sent.
3222 * 		* When a packet is received.
3223 * 	Return
3224 * 		Code **-EINVAL** if the socket is not a full TCP socket;
3225 * 		otherwise, a positive number containing the bits that could not
3226 * 		be set is returned (which comes down to 0 if all bits were set
3227 * 		as required).
3228 *
3229 * long bpf_msg_redirect_map(struct sk_msg_buff *msg, struct bpf_map *map, u32 key, u64 flags)
3230 * 	Description
3231 * 		This helper is used in programs implementing policies at the
3232 * 		socket level. If the message *msg* is allowed to pass (i.e. if
3233 * 		the verdict eBPF program returns **SK_PASS**), redirect it to
3234 * 		the socket referenced by *map* (of type
3235 * 		**BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and
3236 * 		egress interfaces can be used for redirection. The
3237 * 		**BPF_F_INGRESS** value in *flags* is used to make the
3238 * 		distinction (ingress path is selected if the flag is present,
3239 * 		egress path otherwise). This is the only flag supported for now.
3240 * 	Return
3241 * 		**SK_PASS** on success, or **SK_DROP** on error.
3242 *
3243 * long bpf_msg_apply_bytes(struct sk_msg_buff *msg, u32 bytes)
3244 * 	Description
3245 * 		For socket policies, apply the verdict of the eBPF program to
3246 * 		the next *bytes* (number of bytes) of message *msg*.
3247 *
3248 * 		For example, this helper can be used in the following cases:
3249 *
3250 * 		* A single **sendmsg**\ () or **sendfile**\ () system call
3251 * 		  contains multiple logical messages that the eBPF program is
3252 * 		  supposed to read and for which it should apply a verdict.
3253 * 		* An eBPF program only cares to read the first *bytes* of a
3254 * 		  *msg*. If the message has a large payload, then setting up
3255 * 		  and calling the eBPF program repeatedly for all bytes, even
3256 * 		  though the verdict is already known, would create unnecessary
3257 * 		  overhead.
3258 *
3259 * 		When called from within an eBPF program, the helper sets a
3260 * 		counter internal to the BPF infrastructure, that is used to
3261 * 		apply the last verdict to the next *bytes*. If *bytes* is
3262 * 		smaller than the current data being processed from a
3263 * 		**sendmsg**\ () or **sendfile**\ () system call, the first
3264 * 		*bytes* will be sent and the eBPF program will be re-run with
3265 * 		the pointer for start of data pointing to byte number *bytes*
3266 * 		**+ 1**. If *bytes* is larger than the current data being
3267 * 		processed, then the eBPF verdict will be applied to multiple
3268 * 		**sendmsg**\ () or **sendfile**\ () calls until *bytes* are
3269 * 		consumed.
3270 *
3271 * 		Note that if a socket closes with the internal counter holding
3272 * 		a non-zero value, this is not a problem because data is not
3273 * 		being buffered for *bytes* and is sent as it is received.
3274 * 	Return
3275 * 		0
3276 *
3277 * long bpf_msg_cork_bytes(struct sk_msg_buff *msg, u32 bytes)
3278 * 	Description
3279 * 		For socket policies, prevent the execution of the verdict eBPF
3280 * 		program for message *msg* until *bytes* (byte number) have been
3281 * 		accumulated.
3282 *
3283 * 		This can be used when one needs a specific number of bytes
3284 * 		before a verdict can be assigned, even if the data spans
3285 * 		multiple **sendmsg**\ () or **sendfile**\ () calls. The extreme
3286 * 		case would be a user calling **sendmsg**\ () repeatedly with
3287 * 		1-byte long message segments. Obviously, this is bad for
3288 * 		performance, but it is still valid. If the eBPF program needs
3289 * 		*bytes* bytes to validate a header, this helper can be used to
3290 * 		prevent the eBPF program to be called again until *bytes* have
3291 * 		been accumulated.
3292 * 	Return
3293 * 		0
3294 *
3295 * long bpf_msg_pull_data(struct sk_msg_buff *msg, u32 start, u32 end, u64 flags)
3296 * 	Description
3297 * 		For socket policies, pull in non-linear data from user space
3298 * 		for *msg* and set pointers *msg*\ **->data** and *msg*\
3299 * 		**->data_end** to *start* and *end* bytes offsets into *msg*,
3300 * 		respectively.
3301 *
3302 * 		If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a
3303 * 		*msg* it can only parse data that the (**data**, **data_end**)
3304 * 		pointers have already consumed. For **sendmsg**\ () hooks this
3305 * 		is likely the first scatterlist element. But for calls relying
3306 * 		on the **sendpage** handler (e.g. **sendfile**\ ()) this will
3307 * 		be the range (**0**, **0**) because the data is shared with
3308 * 		user space and by default the objective is to avoid allowing
3309 * 		user space to modify data while (or after) eBPF verdict is
3310 * 		being decided. This helper can be used to pull in data and to
3311 * 		set the start and end pointer to given values. Data will be
3312 * 		copied if necessary (i.e. if data was not linear and if start
3313 * 		and end pointers do not point to the same chunk).
3314 *
3315 * 		A call to this helper is susceptible to change the underlying
3316 * 		packet buffer. Therefore, at load time, all checks on pointers
3317 * 		previously done by the verifier are invalidated and must be
3318 * 		performed again, if the helper is used in combination with
3319 * 		direct packet access.
3320 *
3321 * 		All values for *flags* are reserved for future usage, and must
3322 * 		be left at zero.
3323 * 	Return
3324 * 		0 on success, or a negative error in case of failure.
3325 *
3326 * long bpf_bind(struct bpf_sock_addr *ctx, struct sockaddr *addr, int addr_len)
3327 * 	Description
3328 * 		Bind the socket associated to *ctx* to the address pointed by
3329 * 		*addr*, of length *addr_len*. This allows for making outgoing
3330 * 		connection from the desired IP address, which can be useful for
3331 * 		example when all processes inside a cgroup should use one
3332 * 		single IP address on a host that has multiple IP configured.
3333 *
3334 * 		This helper works for IPv4 and IPv6, TCP and UDP sockets. The
3335 * 		domain (*addr*\ **->sa_family**) must be **AF_INET** (or
3336 * 		**AF_INET6**). It's advised to pass zero port (**sin_port**
3337 * 		or **sin6_port**) which triggers IP_BIND_ADDRESS_NO_PORT-like
3338 * 		behavior and lets the kernel efficiently pick up an unused
3339 * 		port as long as 4-tuple is unique. Passing non-zero port might
3340 * 		lead to degraded performance.
3341 * 	Return
3342 * 		0 on success, or a negative error in case of failure.
3343 *
3344 * long bpf_xdp_adjust_tail(struct xdp_buff *xdp_md, int delta)
3345 * 	Description
3346 * 		Adjust (move) *xdp_md*\ **->data_end** by *delta* bytes. It is
3347 * 		possible to both shrink and grow the packet tail.
3348 * 		Shrink done via *delta* being a negative integer.
3349 *
3350 * 		A call to this helper is susceptible to change the underlying
3351 * 		packet buffer. Therefore, at load time, all checks on pointers
3352 * 		previously done by the verifier are invalidated and must be
3353 * 		performed again, if the helper is used in combination with
3354 * 		direct packet access.
3355 * 	Return
3356 * 		0 on success, or a negative error in case of failure.
3357 *
3358 * long bpf_skb_get_xfrm_state(struct sk_buff *skb, u32 index, struct bpf_xfrm_state *xfrm_state, u32 size, u64 flags)
3359 * 	Description
3360 * 		Retrieve the XFRM state (IP transform framework, see also
3361 * 		**ip-xfrm(8)**) at *index* in XFRM "security path" for *skb*.
3362 *
3363 * 		The retrieved value is stored in the **struct bpf_xfrm_state**
3364 * 		pointed by *xfrm_state* and of length *size*.
3365 *
3366 * 		All values for *flags* are reserved for future usage, and must
3367 * 		be left at zero.
3368 *
3369 * 		This helper is available only if the kernel was compiled with
3370 * 		**CONFIG_XFRM** configuration option.
3371 * 	Return
3372 * 		0 on success, or a negative error in case of failure.
3373 *
3374 * long bpf_get_stack(void *ctx, void *buf, u32 size, u64 flags)
3375 * 	Description
3376 * 		Return a user or a kernel stack in bpf program provided buffer.
3377 * 		To achieve this, the helper needs *ctx*, which is a pointer
3378 * 		to the context on which the tracing program is executed.
3379 * 		To store the stacktrace, the bpf program provides *buf* with
3380 * 		a nonnegative *size*.
3381 *
3382 * 		The last argument, *flags*, holds the number of stack frames to
3383 * 		skip (from 0 to 255), masked with
3384 * 		**BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set
3385 * 		the following flags:
3386 *
3387 * 		**BPF_F_USER_STACK**
3388 * 			Collect a user space stack instead of a kernel stack.
3389 * 		**BPF_F_USER_BUILD_ID**
3390 * 			Collect (build_id, file_offset) instead of ips for user
3391 * 			stack, only valid if **BPF_F_USER_STACK** is also
3392 * 			specified.
3393 *
3394 * 			*file_offset* is an offset relative to the beginning
3395 * 			of the executable or shared object file backing the vma
3396 * 			which the *ip* falls in. It is *not* an offset relative
3397 * 			to that object's base address. Accordingly, it must be
3398 * 			adjusted by adding (sh_addr - sh_offset), where
3399 * 			sh_{addr,offset} correspond to the executable section
3400 * 			containing *file_offset* in the object, for comparisons
3401 * 			to symbols' st_value to be valid.
3402 *
3403 * 		**bpf_get_stack**\ () can collect up to
3404 * 		**PERF_MAX_STACK_DEPTH** both kernel and user frames, subject
3405 * 		to sufficient large buffer size. Note that
3406 * 		this limit can be controlled with the **sysctl** program, and
3407 * 		that it should be manually increased in order to profile long
3408 * 		user stacks (such as stacks for Java programs). To do so, use:
3409 *
3410 * 		::
3411 *
3412 * 			# sysctl kernel.perf_event_max_stack=<new value>
3413 * 	Return
3414 * 		The non-negative copied *buf* length equal to or less than
3415 * 		*size* on success, or a negative error in case of failure.
3416 *
3417 * long bpf_skb_load_bytes_relative(const void *skb, u32 offset, void *to, u32 len, u32 start_header)
3418 * 	Description
3419 * 		This helper is similar to **bpf_skb_load_bytes**\ () in that
3420 * 		it provides an easy way to load *len* bytes from *offset*
3421 * 		from the packet associated to *skb*, into the buffer pointed
3422 * 		by *to*. The difference to **bpf_skb_load_bytes**\ () is that
3423 * 		a fifth argument *start_header* exists in order to select a
3424 * 		base offset to start from. *start_header* can be one of:
3425 *
3426 * 		**BPF_HDR_START_MAC**
3427 * 			Base offset to load data from is *skb*'s mac header.
3428 * 		**BPF_HDR_START_NET**
3429 * 			Base offset to load data from is *skb*'s network header.
3430 *
3431 * 		In general, "direct packet access" is the preferred method to
3432 * 		access packet data, however, this helper is in particular useful
3433 * 		in socket filters where *skb*\ **->data** does not always point
3434 * 		to the start of the mac header and where "direct packet access"
3435 * 		is not available.
3436 * 	Return
3437 * 		0 on success, or a negative error in case of failure.
3438 *
3439 * long bpf_fib_lookup(void *ctx, struct bpf_fib_lookup *params, int plen, u32 flags)
3440 *	Description
3441 *		Do FIB lookup in kernel tables using parameters in *params*.
3442 *		If lookup is successful and result shows packet is to be
3443 *		forwarded, the neighbor tables are searched for the nexthop.
3444 *		If successful (ie., FIB lookup shows forwarding and nexthop
3445 *		is resolved), the nexthop address is returned in ipv4_dst
3446 *		or ipv6_dst based on family, smac is set to mac address of
3447 *		egress device, dmac is set to nexthop mac address, rt_metric
3448 *		is set to metric from route (IPv4/IPv6 only), and ifindex
3449 *		is set to the device index of the nexthop from the FIB lookup.
3450 *
3451 *		*plen* argument is the size of the passed in struct.
3452 *		*flags* argument can be a combination of one or more of the
3453 *		following values:
3454 *
3455 *		**BPF_FIB_LOOKUP_DIRECT**
3456 *			Do a direct table lookup vs full lookup using FIB
3457 *			rules.
3458 *		**BPF_FIB_LOOKUP_TBID**
3459 *			Used with BPF_FIB_LOOKUP_DIRECT.
3460 *			Use the routing table ID present in *params*->tbid
3461 *			for the fib lookup.
3462 *		**BPF_FIB_LOOKUP_OUTPUT**
3463 *			Perform lookup from an egress perspective (default is
3464 *			ingress).
3465 *		**BPF_FIB_LOOKUP_SKIP_NEIGH**
3466 *			Skip the neighbour table lookup. *params*->dmac
3467 *			and *params*->smac will not be set as output. A common
3468 *			use case is to call **bpf_redirect_neigh**\ () after
3469 *			doing **bpf_fib_lookup**\ ().
3470 *		**BPF_FIB_LOOKUP_SRC**
3471 *			Derive and set source IP addr in *params*->ipv{4,6}_src
3472 *			for the nexthop. If the src addr cannot be derived,
3473 *			**BPF_FIB_LKUP_RET_NO_SRC_ADDR** is returned. In this
3474 *			case, *params*->dmac and *params*->smac are not set either.
3475 *		**BPF_FIB_LOOKUP_MARK**
3476 *			Use the mark present in *params*->mark for the fib lookup.
3477 *			This option should not be used with BPF_FIB_LOOKUP_DIRECT,
3478 *			as it only has meaning for full lookups.
3479 *
3480 *		*ctx* is either **struct xdp_md** for XDP programs or
3481 *		**struct sk_buff** tc cls_act programs.
3482 *	Return
3483 *		* < 0 if any input argument is invalid
3484 *		*   0 on success (packet is forwarded, nexthop neighbor exists)
3485 *		* > 0 one of **BPF_FIB_LKUP_RET_** codes explaining why the
3486 *		  packet is not forwarded or needs assist from full stack
3487 *
3488 *		If lookup fails with BPF_FIB_LKUP_RET_FRAG_NEEDED, then the MTU
3489 *		was exceeded and output params->mtu_result contains the MTU.
3490 *
3491 * long bpf_sock_hash_update(struct bpf_sock_ops *skops, struct bpf_map *map, void *key, u64 flags)
3492 *	Description
3493 *		Add an entry to, or update a sockhash *map* referencing sockets.
3494 *		The *skops* is used as a new value for the entry associated to
3495 *		*key*. *flags* is one of:
3496 *
3497 *		**BPF_NOEXIST**
3498 *			The entry for *key* must not exist in the map.
3499 *		**BPF_EXIST**
3500 *			The entry for *key* must already exist in the map.
3501 *		**BPF_ANY**
3502 *			No condition on the existence of the entry for *key*.
3503 *
3504 *		If the *map* has eBPF programs (parser and verdict), those will
3505 *		be inherited by the socket being added. If the socket is
3506 *		already attached to eBPF programs, this results in an error.
3507 *	Return
3508 *		0 on success, or a negative error in case of failure.
3509 *
3510 * long bpf_msg_redirect_hash(struct sk_msg_buff *msg, struct bpf_map *map, void *key, u64 flags)
3511 *	Description
3512 *		This helper is used in programs implementing policies at the
3513 *		socket level. If the message *msg* is allowed to pass (i.e. if
3514 *		the verdict eBPF program returns **SK_PASS**), redirect it to
3515 *		the socket referenced by *map* (of type
3516 *		**BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and
3517 *		egress interfaces can be used for redirection. The
3518 *		**BPF_F_INGRESS** value in *flags* is used to make the
3519 *		distinction (ingress path is selected if the flag is present,
3520 *		egress path otherwise). This is the only flag supported for now.
3521 *	Return
3522 *		**SK_PASS** on success, or **SK_DROP** on error.
3523 *
3524 * long bpf_sk_redirect_hash(struct sk_buff *skb, struct bpf_map *map, void *key, u64 flags)
3525 *	Description
3526 *		This helper is used in programs implementing policies at the
3527 *		skb socket level. If the sk_buff *skb* is allowed to pass (i.e.
3528 *		if the verdict eBPF program returns **SK_PASS**), redirect it
3529 *		to the socket referenced by *map* (of type
3530 *		**BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and
3531 *		egress interfaces can be used for redirection. The
3532 *		**BPF_F_INGRESS** value in *flags* is used to make the
3533 *		distinction (ingress path is selected if the flag is present,
3534 *		egress otherwise). This is the only flag supported for now.
3535 *	Return
3536 *		**SK_PASS** on success, or **SK_DROP** on error.
3537 *
3538 * long bpf_lwt_push_encap(struct sk_buff *skb, u32 type, void *hdr, u32 len)
3539 *	Description
3540 *		Encapsulate the packet associated to *skb* within a Layer 3
3541 *		protocol header. This header is provided in the buffer at
3542 *		address *hdr*, with *len* its size in bytes. *type* indicates
3543 *		the protocol of the header and can be one of:
3544 *
3545 *		**BPF_LWT_ENCAP_SEG6**
3546 *			IPv6 encapsulation with Segment Routing Header
3547 *			(**struct ipv6_sr_hdr**). *hdr* only contains the SRH,
3548 *			the IPv6 header is computed by the kernel.
3549 *		**BPF_LWT_ENCAP_SEG6_INLINE**
3550 *			Only works if *skb* contains an IPv6 packet. Insert a
3551 *			Segment Routing Header (**struct ipv6_sr_hdr**) inside
3552 *			the IPv6 header.
3553 *		**BPF_LWT_ENCAP_IP**
3554 *			IP encapsulation (GRE/GUE/IPIP/etc). The outer header
3555 *			must be IPv4 or IPv6, followed by zero or more
3556 *			additional headers, up to **LWT_BPF_MAX_HEADROOM**
3557 *			total bytes in all prepended headers. Please note that
3558 *			if **skb_is_gso**\ (*skb*) is true, no more than two
3559 *			headers can be prepended, and the inner header, if
3560 *			present, should be either GRE or UDP/GUE.
3561 *
3562 *		**BPF_LWT_ENCAP_SEG6**\ \* types can be called by BPF programs
3563 *		of type **BPF_PROG_TYPE_LWT_IN**; **BPF_LWT_ENCAP_IP** type can
3564 *		be called by bpf programs of types **BPF_PROG_TYPE_LWT_IN** and
3565 *		**BPF_PROG_TYPE_LWT_XMIT**.
3566 *
3567 * 		A call to this helper is susceptible to change the underlying
3568 * 		packet buffer. Therefore, at load time, all checks on pointers
3569 * 		previously done by the verifier are invalidated and must be
3570 * 		performed again, if the helper is used in combination with
3571 * 		direct packet access.
3572 *	Return
3573 * 		0 on success, or a negative error in case of failure.
3574 *
3575 * long bpf_lwt_seg6_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len)
3576 *	Description
3577 *		Store *len* bytes from address *from* into the packet
3578 *		associated to *skb*, at *offset*. Only the flags, tag and TLVs
3579 *		inside the outermost IPv6 Segment Routing Header can be
3580 *		modified through this helper.
3581 *
3582 * 		A call to this helper is susceptible to change the underlying
3583 * 		packet buffer. Therefore, at load time, all checks on pointers
3584 * 		previously done by the verifier are invalidated and must be
3585 * 		performed again, if the helper is used in combination with
3586 * 		direct packet access.
3587 *	Return
3588 * 		0 on success, or a negative error in case of failure.
3589 *
3590 * long bpf_lwt_seg6_adjust_srh(struct sk_buff *skb, u32 offset, s32 delta)
3591 *	Description
3592 *		Adjust the size allocated to TLVs in the outermost IPv6
3593 *		Segment Routing Header contained in the packet associated to
3594 *		*skb*, at position *offset* by *delta* bytes. Only offsets
3595 *		after the segments are accepted. *delta* can be as well
3596 *		positive (growing) as negative (shrinking).
3597 *
3598 * 		A call to this helper is susceptible to change the underlying
3599 * 		packet buffer. Therefore, at load time, all checks on pointers
3600 * 		previously done by the verifier are invalidated and must be
3601 * 		performed again, if the helper is used in combination with
3602 * 		direct packet access.
3603 *	Return
3604 * 		0 on success, or a negative error in case of failure.
3605 *
3606 * long bpf_lwt_seg6_action(struct sk_buff *skb, u32 action, void *param, u32 param_len)
3607 *	Description
3608 *		Apply an IPv6 Segment Routing action of type *action* to the
3609 *		packet associated to *skb*. Each action takes a parameter
3610 *		contained at address *param*, and of length *param_len* bytes.
3611 *		*action* can be one of:
3612 *
3613 *		**SEG6_LOCAL_ACTION_END_X**
3614 *			End.X action: Endpoint with Layer-3 cross-connect.
3615 *			Type of *param*: **struct in6_addr**.
3616 *		**SEG6_LOCAL_ACTION_END_T**
3617 *			End.T action: Endpoint with specific IPv6 table lookup.
3618 *			Type of *param*: **int**.
3619 *		**SEG6_LOCAL_ACTION_END_B6**
3620 *			End.B6 action: Endpoint bound to an SRv6 policy.
3621 *			Type of *param*: **struct ipv6_sr_hdr**.
3622 *		**SEG6_LOCAL_ACTION_END_B6_ENCAP**
3623 *			End.B6.Encap action: Endpoint bound to an SRv6
3624 *			encapsulation policy.
3625 *			Type of *param*: **struct ipv6_sr_hdr**.
3626 *
3627 * 		A call to this helper is susceptible to change the underlying
3628 * 		packet buffer. Therefore, at load time, all checks on pointers
3629 * 		previously done by the verifier are invalidated and must be
3630 * 		performed again, if the helper is used in combination with
3631 * 		direct packet access.
3632 *	Return
3633 * 		0 on success, or a negative error in case of failure.
3634 *
3635 * long bpf_rc_repeat(void *ctx)
3636 *	Description
3637 *		This helper is used in programs implementing IR decoding, to
3638 *		report a successfully decoded repeat key message. This delays
3639 *		the generation of a key up event for previously generated
3640 *		key down event.
3641 *
3642 *		Some IR protocols like NEC have a special IR message for
3643 *		repeating last button, for when a button is held down.
3644 *
3645 *		The *ctx* should point to the lirc sample as passed into
3646 *		the program.
3647 *
3648 *		This helper is only available is the kernel was compiled with
3649 *		the **CONFIG_BPF_LIRC_MODE2** configuration option set to
3650 *		"**y**".
3651 *	Return
3652 *		0
3653 *
3654 * long bpf_rc_keydown(void *ctx, u32 protocol, u64 scancode, u32 toggle)
3655 *	Description
3656 *		This helper is used in programs implementing IR decoding, to
3657 *		report a successfully decoded key press with *scancode*,
3658 *		*toggle* value in the given *protocol*. The scancode will be
3659 *		translated to a keycode using the rc keymap, and reported as
3660 *		an input key down event. After a period a key up event is
3661 *		generated. This period can be extended by calling either
3662 *		**bpf_rc_keydown**\ () again with the same values, or calling
3663 *		**bpf_rc_repeat**\ ().
3664 *
3665 *		Some protocols include a toggle bit, in case the button was
3666 *		released and pressed again between consecutive scancodes.
3667 *
3668 *		The *ctx* should point to the lirc sample as passed into
3669 *		the program.
3670 *
3671 *		The *protocol* is the decoded protocol number (see
3672 *		**enum rc_proto** for some predefined values).
3673 *
3674 *		This helper is only available is the kernel was compiled with
3675 *		the **CONFIG_BPF_LIRC_MODE2** configuration option set to
3676 *		"**y**".
3677 *	Return
3678 *		0
3679 *
3680 * u64 bpf_skb_cgroup_id(struct sk_buff *skb)
3681 * 	Description
3682 * 		Return the cgroup v2 id of the socket associated with the *skb*.
3683 * 		This is roughly similar to the **bpf_get_cgroup_classid**\ ()
3684 * 		helper for cgroup v1 by providing a tag resp. identifier that
3685 * 		can be matched on or used for map lookups e.g. to implement
3686 * 		policy. The cgroup v2 id of a given path in the hierarchy is
3687 * 		exposed in user space through the f_handle API in order to get
3688 * 		to the same 64-bit id.
3689 *
3690 * 		This helper can be used on TC egress path, but not on ingress,
3691 * 		and is available only if the kernel was compiled with the
3692 * 		**CONFIG_SOCK_CGROUP_DATA** configuration option.
3693 * 	Return
3694 * 		The id is returned or 0 in case the id could not be retrieved.
3695 *
3696 * u64 bpf_get_current_cgroup_id(void)
3697 * 	Description
3698 * 		Get the current cgroup id based on the cgroup within which
3699 * 		the current task is running.
3700 * 	Return
3701 * 		A 64-bit integer containing the current cgroup id based
3702 * 		on the cgroup within which the current task is running.
3703 *
3704 * void *bpf_get_local_storage(void *map, u64 flags)
3705 *	Description
3706 *		Get the pointer to the local storage area.
3707 *		The type and the size of the local storage is defined
3708 *		by the *map* argument.
3709 *		The *flags* meaning is specific for each map type,
3710 *		and has to be 0 for cgroup local storage.
3711 *
3712 *		Depending on the BPF program type, a local storage area
3713 *		can be shared between multiple instances of the BPF program,
3714 *		running simultaneously.
3715 *
3716 *		A user should care about the synchronization by himself.
3717 *		For example, by using the **BPF_ATOMIC** instructions to alter
3718 *		the shared data.
3719 *	Return
3720 *		A pointer to the local storage area.
3721 *
3722 * long bpf_sk_select_reuseport(struct sk_reuseport_md *reuse, struct bpf_map *map, void *key, u64 flags)
3723 *	Description
3724 *		Select a **SO_REUSEPORT** socket from a
3725 *		**BPF_MAP_TYPE_REUSEPORT_SOCKARRAY** *map*.
3726 *		It checks the selected socket is matching the incoming
3727 *		request in the socket buffer.
3728 *	Return
3729 *		0 on success, or a negative error in case of failure.
3730 *
3731 * u64 bpf_skb_ancestor_cgroup_id(struct sk_buff *skb, int ancestor_level)
3732 *	Description
3733 *		Return id of cgroup v2 that is ancestor of cgroup associated
3734 *		with the *skb* at the *ancestor_level*.  The root cgroup is at
3735 *		*ancestor_level* zero and each step down the hierarchy
3736 *		increments the level. If *ancestor_level* == level of cgroup
3737 *		associated with *skb*, then return value will be same as that
3738 *		of **bpf_skb_cgroup_id**\ ().
3739 *
3740 *		The helper is useful to implement policies based on cgroups
3741 *		that are upper in hierarchy than immediate cgroup associated
3742 *		with *skb*.
3743 *
3744 *		The format of returned id and helper limitations are same as in
3745 *		**bpf_skb_cgroup_id**\ ().
3746 *	Return
3747 *		The id is returned or 0 in case the id could not be retrieved.
3748 *
3749 * struct bpf_sock *bpf_sk_lookup_tcp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags)
3750 *	Description
3751 *		Look for TCP socket matching *tuple*, optionally in a child
3752 *		network namespace *netns*. The return value must be checked,
3753 *		and if non-**NULL**, released via **bpf_sk_release**\ ().
3754 *
3755 *		The *ctx* should point to the context of the program, such as
3756 *		the skb or socket (depending on the hook in use). This is used
3757 *		to determine the base network namespace for the lookup.
3758 *
3759 *		*tuple_size* must be one of:
3760 *
3761 *		**sizeof**\ (*tuple*\ **->ipv4**)
3762 *			Look for an IPv4 socket.
3763 *		**sizeof**\ (*tuple*\ **->ipv6**)
3764 *			Look for an IPv6 socket.
3765 *
3766 *		If the *netns* is a negative signed 32-bit integer, then the
3767 *		socket lookup table in the netns associated with the *ctx*
3768 *		will be used. For the TC hooks, this is the netns of the device
3769 *		in the skb. For socket hooks, this is the netns of the socket.
3770 *		If *netns* is any other signed 32-bit value greater than or
3771 *		equal to zero then it specifies the ID of the netns relative to
3772 *		the netns associated with the *ctx*. *netns* values beyond the
3773 *		range of 32-bit integers are reserved for future use.
3774 *
3775 *		All values for *flags* are reserved for future usage, and must
3776 *		be left at zero.
3777 *
3778 *		This helper is available only if the kernel was compiled with
3779 *		**CONFIG_NET** configuration option.
3780 *	Return
3781 *		Pointer to **struct bpf_sock**, or **NULL** in case of failure.
3782 *		For sockets with reuseport option, the **struct bpf_sock**
3783 *		result is from *reuse*\ **->socks**\ [] using the hash of the
3784 *		tuple.
3785 *
3786 * struct bpf_sock *bpf_sk_lookup_udp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags)
3787 *	Description
3788 *		Look for UDP socket matching *tuple*, optionally in a child
3789 *		network namespace *netns*. The return value must be checked,
3790 *		and if non-**NULL**, released via **bpf_sk_release**\ ().
3791 *
3792 *		The *ctx* should point to the context of the program, such as
3793 *		the skb or socket (depending on the hook in use). This is used
3794 *		to determine the base network namespace for the lookup.
3795 *
3796 *		*tuple_size* must be one of:
3797 *
3798 *		**sizeof**\ (*tuple*\ **->ipv4**)
3799 *			Look for an IPv4 socket.
3800 *		**sizeof**\ (*tuple*\ **->ipv6**)
3801 *			Look for an IPv6 socket.
3802 *
3803 *		If the *netns* is a negative signed 32-bit integer, then the
3804 *		socket lookup table in the netns associated with the *ctx*
3805 *		will be used. For the TC hooks, this is the netns of the device
3806 *		in the skb. For socket hooks, this is the netns of the socket.
3807 *		If *netns* is any other signed 32-bit value greater than or
3808 *		equal to zero then it specifies the ID of the netns relative to
3809 *		the netns associated with the *ctx*. *netns* values beyond the
3810 *		range of 32-bit integers are reserved for future use.
3811 *
3812 *		All values for *flags* are reserved for future usage, and must
3813 *		be left at zero.
3814 *
3815 *		This helper is available only if the kernel was compiled with
3816 *		**CONFIG_NET** configuration option.
3817 *	Return
3818 *		Pointer to **struct bpf_sock**, or **NULL** in case of failure.
3819 *		For sockets with reuseport option, the **struct bpf_sock**
3820 *		result is from *reuse*\ **->socks**\ [] using the hash of the
3821 *		tuple.
3822 *
3823 * long bpf_sk_release(void *sock)
3824 *	Description
3825 *		Release the reference held by *sock*. *sock* must be a
3826 *		non-**NULL** pointer that was returned from
3827 *		**bpf_sk_lookup_xxx**\ ().
3828 *	Return
3829 *		0 on success, or a negative error in case of failure.
3830 *
3831 * long bpf_map_push_elem(struct bpf_map *map, const void *value, u64 flags)
3832 * 	Description
3833 * 		Push an element *value* in *map*. *flags* is one of:
3834 *
3835 * 		**BPF_EXIST**
3836 * 			If the queue/stack is full, the oldest element is
3837 * 			removed to make room for this.
3838 * 	Return
3839 * 		0 on success, or a negative error in case of failure.
3840 *
3841 * long bpf_map_pop_elem(struct bpf_map *map, void *value)
3842 * 	Description
3843 * 		Pop an element from *map*.
3844 * 	Return
3845 * 		0 on success, or a negative error in case of failure.
3846 *
3847 * long bpf_map_peek_elem(struct bpf_map *map, void *value)
3848 * 	Description
3849 * 		Get an element from *map* without removing it.
3850 * 	Return
3851 * 		0 on success, or a negative error in case of failure.
3852 *
3853 * long bpf_msg_push_data(struct sk_msg_buff *msg, u32 start, u32 len, u64 flags)
3854 *	Description
3855 *		For socket policies, insert *len* bytes into *msg* at offset
3856 *		*start*.
3857 *
3858 *		If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a
3859 *		*msg* it may want to insert metadata or options into the *msg*.
3860 *		This can later be read and used by any of the lower layer BPF
3861 *		hooks.
3862 *
3863 *		This helper may fail if under memory pressure (a malloc
3864 *		fails) in these cases BPF programs will get an appropriate
3865 *		error and BPF programs will need to handle them.
3866 *	Return
3867 *		0 on success, or a negative error in case of failure.
3868 *
3869 * long bpf_msg_pop_data(struct sk_msg_buff *msg, u32 start, u32 len, u64 flags)
3870 *	Description
3871 *		Will remove *len* bytes from a *msg* starting at byte *start*.
3872 *		This may result in **ENOMEM** errors under certain situations if
3873 *		an allocation and copy are required due to a full ring buffer.
3874 *		However, the helper will try to avoid doing the allocation
3875 *		if possible. Other errors can occur if input parameters are
3876 *		invalid either due to *start* byte not being valid part of *msg*
3877 *		payload and/or *pop* value being to large.
3878 *	Return
3879 *		0 on success, or a negative error in case of failure.
3880 *
3881 * long bpf_rc_pointer_rel(void *ctx, s32 rel_x, s32 rel_y)
3882 *	Description
3883 *		This helper is used in programs implementing IR decoding, to
3884 *		report a successfully decoded pointer movement.
3885 *
3886 *		The *ctx* should point to the lirc sample as passed into
3887 *		the program.
3888 *
3889 *		This helper is only available is the kernel was compiled with
3890 *		the **CONFIG_BPF_LIRC_MODE2** configuration option set to
3891 *		"**y**".
3892 *	Return
3893 *		0
3894 *
3895 * long bpf_spin_lock(struct bpf_spin_lock *lock)
3896 *	Description
3897 *		Acquire a spinlock represented by the pointer *lock*, which is
3898 *		stored as part of a value of a map. Taking the lock allows to
3899 *		safely update the rest of the fields in that value. The
3900 *		spinlock can (and must) later be released with a call to
3901 *		**bpf_spin_unlock**\ (\ *lock*\ ).
3902 *
3903 *		Spinlocks in BPF programs come with a number of restrictions
3904 *		and constraints:
3905 *
3906 *		* **bpf_spin_lock** objects are only allowed inside maps of
3907 *		  types **BPF_MAP_TYPE_HASH** and **BPF_MAP_TYPE_ARRAY** (this
3908 *		  list could be extended in the future).
3909 *		* BTF description of the map is mandatory.
3910 *		* The BPF program can take ONE lock at a time, since taking two
3911 *		  or more could cause dead locks.
3912 *		* Only one **struct bpf_spin_lock** is allowed per map element.
3913 *		* When the lock is taken, calls (either BPF to BPF or helpers)
3914 *		  are not allowed.
3915 *		* The **BPF_LD_ABS** and **BPF_LD_IND** instructions are not
3916 *		  allowed inside a spinlock-ed region.
3917 *		* The BPF program MUST call **bpf_spin_unlock**\ () to release
3918 *		  the lock, on all execution paths, before it returns.
3919 *		* The BPF program can access **struct bpf_spin_lock** only via
3920 *		  the **bpf_spin_lock**\ () and **bpf_spin_unlock**\ ()
3921 *		  helpers. Loading or storing data into the **struct
3922 *		  bpf_spin_lock** *lock*\ **;** field of a map is not allowed.
3923 *		* To use the **bpf_spin_lock**\ () helper, the BTF description
3924 *		  of the map value must be a struct and have **struct
3925 *		  bpf_spin_lock** *anyname*\ **;** field at the top level.
3926 *		  Nested lock inside another struct is not allowed.
3927 *		* The **struct bpf_spin_lock** *lock* field in a map value must
3928 *		  be aligned on a multiple of 4 bytes in that value.
3929 *		* Syscall with command **BPF_MAP_LOOKUP_ELEM** does not copy
3930 *		  the **bpf_spin_lock** field to user space.
3931 *		* Syscall with command **BPF_MAP_UPDATE_ELEM**, or update from
3932 *		  a BPF program, do not update the **bpf_spin_lock** field.
3933 *		* **bpf_spin_lock** cannot be on the stack or inside a
3934 *		  networking packet (it can only be inside of a map values).
3935 *		* **bpf_spin_lock** is available to root only.
3936 *		* Tracing programs and socket filter programs cannot use
3937 *		  **bpf_spin_lock**\ () due to insufficient preemption checks
3938 *		  (but this may change in the future).
3939 *		* **bpf_spin_lock** is not allowed in inner maps of map-in-map.
3940 *	Return
3941 *		0
3942 *
3943 * long bpf_spin_unlock(struct bpf_spin_lock *lock)
3944 *	Description
3945 *		Release the *lock* previously locked by a call to
3946 *		**bpf_spin_lock**\ (\ *lock*\ ).
3947 *	Return
3948 *		0
3949 *
3950 * struct bpf_sock *bpf_sk_fullsock(struct bpf_sock *sk)
3951 *	Description
3952 *		This helper gets a **struct bpf_sock** pointer such
3953 *		that all the fields in this **bpf_sock** can be accessed.
3954 *	Return
3955 *		A **struct bpf_sock** pointer on success, or **NULL** in
3956 *		case of failure.
3957 *
3958 * struct bpf_tcp_sock *bpf_tcp_sock(struct bpf_sock *sk)
3959 *	Description
3960 *		This helper gets a **struct bpf_tcp_sock** pointer from a
3961 *		**struct bpf_sock** pointer.
3962 *	Return
3963 *		A **struct bpf_tcp_sock** pointer on success, or **NULL** in
3964 *		case of failure.
3965 *
3966 * long bpf_skb_ecn_set_ce(struct sk_buff *skb)
3967 *	Description
3968 *		Set ECN (Explicit Congestion Notification) field of IP header
3969 *		to **CE** (Congestion Encountered) if current value is **ECT**
3970 *		(ECN Capable Transport). Otherwise, do nothing. Works with IPv6
3971 *		and IPv4.
3972 *	Return
3973 *		1 if the **CE** flag is set (either by the current helper call
3974 *		or because it was already present), 0 if it is not set.
3975 *
3976 * struct bpf_sock *bpf_get_listener_sock(struct bpf_sock *sk)
3977 *	Description
3978 *		Return a **struct bpf_sock** pointer in **TCP_LISTEN** state.
3979 *		**bpf_sk_release**\ () is unnecessary and not allowed.
3980 *	Return
3981 *		A **struct bpf_sock** pointer on success, or **NULL** in
3982 *		case of failure.
3983 *
3984 * struct bpf_sock *bpf_skc_lookup_tcp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags)
3985 *	Description
3986 *		Look for TCP socket matching *tuple*, optionally in a child
3987 *		network namespace *netns*. The return value must be checked,
3988 *		and if non-**NULL**, released via **bpf_sk_release**\ ().
3989 *
3990 *		This function is identical to **bpf_sk_lookup_tcp**\ (), except
3991 *		that it also returns timewait or request sockets. Use
3992 *		**bpf_sk_fullsock**\ () or **bpf_tcp_sock**\ () to access the
3993 *		full structure.
3994 *
3995 *		This helper is available only if the kernel was compiled with
3996 *		**CONFIG_NET** configuration option.
3997 *	Return
3998 *		Pointer to **struct bpf_sock**, or **NULL** in case of failure.
3999 *		For sockets with reuseport option, the **struct bpf_sock**
4000 *		result is from *reuse*\ **->socks**\ [] using the hash of the
4001 *		tuple.
4002 *
4003 * long bpf_tcp_check_syncookie(void *sk, void *iph, u32 iph_len, struct tcphdr *th, u32 th_len)
4004 * 	Description
4005 * 		Check whether *iph* and *th* contain a valid SYN cookie ACK for
4006 * 		the listening socket in *sk*.
4007 *
4008 * 		*iph* points to the start of the IPv4 or IPv6 header, while
4009 * 		*iph_len* contains **sizeof**\ (**struct iphdr**) or
4010 * 		**sizeof**\ (**struct ipv6hdr**).
4011 *
4012 * 		*th* points to the start of the TCP header, while *th_len*
4013 *		contains the length of the TCP header (at least
4014 *		**sizeof**\ (**struct tcphdr**)).
4015 * 	Return
4016 * 		0 if *iph* and *th* are a valid SYN cookie ACK, or a negative
4017 * 		error otherwise.
4018 *
4019 * long bpf_sysctl_get_name(struct bpf_sysctl *ctx, char *buf, size_t buf_len, u64 flags)
4020 *	Description
4021 *		Get name of sysctl in /proc/sys/ and copy it into provided by
4022 *		program buffer *buf* of size *buf_len*.
4023 *
4024 *		The buffer is always NUL terminated, unless it's zero-sized.
4025 *
4026 *		If *flags* is zero, full name (e.g. "net/ipv4/tcp_mem") is
4027 *		copied. Use **BPF_F_SYSCTL_BASE_NAME** flag to copy base name
4028 *		only (e.g. "tcp_mem").
4029 *	Return
4030 *		Number of character copied (not including the trailing NUL).
4031 *
4032 *		**-E2BIG** if the buffer wasn't big enough (*buf* will contain
4033 *		truncated name in this case).
4034 *
4035 * long bpf_sysctl_get_current_value(struct bpf_sysctl *ctx, char *buf, size_t buf_len)
4036 *	Description
4037 *		Get current value of sysctl as it is presented in /proc/sys
4038 *		(incl. newline, etc), and copy it as a string into provided
4039 *		by program buffer *buf* of size *buf_len*.
4040 *
4041 *		The whole value is copied, no matter what file position user
4042 *		space issued e.g. sys_read at.
4043 *
4044 *		The buffer is always NUL terminated, unless it's zero-sized.
4045 *	Return
4046 *		Number of character copied (not including the trailing NUL).
4047 *
4048 *		**-E2BIG** if the buffer wasn't big enough (*buf* will contain
4049 *		truncated name in this case).
4050 *
4051 *		**-EINVAL** if current value was unavailable, e.g. because
4052 *		sysctl is uninitialized and read returns -EIO for it.
4053 *
4054 * long bpf_sysctl_get_new_value(struct bpf_sysctl *ctx, char *buf, size_t buf_len)
4055 *	Description
4056 *		Get new value being written by user space to sysctl (before
4057 *		the actual write happens) and copy it as a string into
4058 *		provided by program buffer *buf* of size *buf_len*.
4059 *
4060 *		User space may write new value at file position > 0.
4061 *
4062 *		The buffer is always NUL terminated, unless it's zero-sized.
4063 *	Return
4064 *		Number of character copied (not including the trailing NUL).
4065 *
4066 *		**-E2BIG** if the buffer wasn't big enough (*buf* will contain
4067 *		truncated name in this case).
4068 *
4069 *		**-EINVAL** if sysctl is being read.
4070 *
4071 * long bpf_sysctl_set_new_value(struct bpf_sysctl *ctx, const char *buf, size_t buf_len)
4072 *	Description
4073 *		Override new value being written by user space to sysctl with
4074 *		value provided by program in buffer *buf* of size *buf_len*.
4075 *
4076 *		*buf* should contain a string in same form as provided by user
4077 *		space on sysctl write.
4078 *
4079 *		User space may write new value at file position > 0. To override
4080 *		the whole sysctl value file position should be set to zero.
4081 *	Return
4082 *		0 on success.
4083 *
4084 *		**-E2BIG** if the *buf_len* is too big.
4085 *
4086 *		**-EINVAL** if sysctl is being read.
4087 *
4088 * long bpf_strtol(const char *buf, size_t buf_len, u64 flags, long *res)
4089 *	Description
4090 *		Convert the initial part of the string from buffer *buf* of
4091 *		size *buf_len* to a long integer according to the given base
4092 *		and save the result in *res*.
4093 *
4094 *		The string may begin with an arbitrary amount of white space
4095 *		(as determined by **isspace**\ (3)) followed by a single
4096 *		optional '**-**' sign.
4097 *
4098 *		Five least significant bits of *flags* encode base, other bits
4099 *		are currently unused.
4100 *
4101 *		Base must be either 8, 10, 16 or 0 to detect it automatically
4102 *		similar to user space **strtol**\ (3).
4103 *	Return
4104 *		Number of characters consumed on success. Must be positive but
4105 *		no more than *buf_len*.
4106 *
4107 *		**-EINVAL** if no valid digits were found or unsupported base
4108 *		was provided.
4109 *
4110 *		**-ERANGE** if resulting value was out of range.
4111 *
4112 * long bpf_strtoul(const char *buf, size_t buf_len, u64 flags, unsigned long *res)
4113 *	Description
4114 *		Convert the initial part of the string from buffer *buf* of
4115 *		size *buf_len* to an unsigned long integer according to the
4116 *		given base and save the result in *res*.
4117 *
4118 *		The string may begin with an arbitrary amount of white space
4119 *		(as determined by **isspace**\ (3)).
4120 *
4121 *		Five least significant bits of *flags* encode base, other bits
4122 *		are currently unused.
4123 *
4124 *		Base must be either 8, 10, 16 or 0 to detect it automatically
4125 *		similar to user space **strtoul**\ (3).
4126 *	Return
4127 *		Number of characters consumed on success. Must be positive but
4128 *		no more than *buf_len*.
4129 *
4130 *		**-EINVAL** if no valid digits were found or unsupported base
4131 *		was provided.
4132 *
4133 *		**-ERANGE** if resulting value was out of range.
4134 *
4135 * void *bpf_sk_storage_get(struct bpf_map *map, void *sk, void *value, u64 flags)
4136 *	Description
4137 *		Get a bpf-local-storage from a *sk*.
4138 *
4139 *		Logically, it could be thought of getting the value from
4140 *		a *map* with *sk* as the **key**.  From this
4141 *		perspective,  the usage is not much different from
4142 *		**bpf_map_lookup_elem**\ (*map*, **&**\ *sk*) except this
4143 *		helper enforces the key must be a full socket and the map must
4144 *		be a **BPF_MAP_TYPE_SK_STORAGE** also.
4145 *
4146 *		Underneath, the value is stored locally at *sk* instead of
4147 *		the *map*.  The *map* is used as the bpf-local-storage
4148 *		"type". The bpf-local-storage "type" (i.e. the *map*) is
4149 *		searched against all bpf-local-storages residing at *sk*.
4150 *
4151 *		*sk* is a kernel **struct sock** pointer for LSM program.
4152 *		*sk* is a **struct bpf_sock** pointer for other program types.
4153 *
4154 *		An optional *flags* (**BPF_SK_STORAGE_GET_F_CREATE**) can be
4155 *		used such that a new bpf-local-storage will be
4156 *		created if one does not exist.  *value* can be used
4157 *		together with **BPF_SK_STORAGE_GET_F_CREATE** to specify
4158 *		the initial value of a bpf-local-storage.  If *value* is
4159 *		**NULL**, the new bpf-local-storage will be zero initialized.
4160 *	Return
4161 *		A bpf-local-storage pointer is returned on success.
4162 *
4163 *		**NULL** if not found or there was an error in adding
4164 *		a new bpf-local-storage.
4165 *
4166 * long bpf_sk_storage_delete(struct bpf_map *map, void *sk)
4167 *	Description
4168 *		Delete a bpf-local-storage from a *sk*.
4169 *	Return
4170 *		0 on success.
4171 *
4172 *		**-ENOENT** if the bpf-local-storage cannot be found.
4173 *		**-EINVAL** if sk is not a fullsock (e.g. a request_sock).
4174 *
4175 * long bpf_send_signal(u32 sig)
4176 *	Description
4177 *		Send signal *sig* to the process of the current task.
4178 *		The signal may be delivered to any of this process's threads.
4179 *	Return
4180 *		0 on success or successfully queued.
4181 *
4182 *		**-EBUSY** if work queue under nmi is full.
4183 *
4184 *		**-EINVAL** if *sig* is invalid.
4185 *
4186 *		**-EPERM** if no permission to send the *sig*.
4187 *
4188 *		**-EAGAIN** if bpf program can try again.
4189 *
4190 * s64 bpf_tcp_gen_syncookie(void *sk, void *iph, u32 iph_len, struct tcphdr *th, u32 th_len)
4191 *	Description
4192 *		Try to issue a SYN cookie for the packet with corresponding
4193 *		IP/TCP headers, *iph* and *th*, on the listening socket in *sk*.
4194 *
4195 *		*iph* points to the start of the IPv4 or IPv6 header, while
4196 *		*iph_len* contains **sizeof**\ (**struct iphdr**) or
4197 *		**sizeof**\ (**struct ipv6hdr**).
4198 *
4199 *		*th* points to the start of the TCP header, while *th_len*
4200 *		contains the length of the TCP header with options (at least
4201 *		**sizeof**\ (**struct tcphdr**)).
4202 *	Return
4203 *		On success, lower 32 bits hold the generated SYN cookie in
4204 *		followed by 16 bits which hold the MSS value for that cookie,
4205 *		and the top 16 bits are unused.
4206 *
4207 *		On failure, the returned value is one of the following:
4208 *
4209 *		**-EINVAL** SYN cookie cannot be issued due to error
4210 *
4211 *		**-ENOENT** SYN cookie should not be issued (no SYN flood)
4212 *
4213 *		**-EOPNOTSUPP** kernel configuration does not enable SYN cookies
4214 *
4215 *		**-EPROTONOSUPPORT** IP packet version is not 4 or 6
4216 *
4217 * long bpf_skb_output(void *ctx, struct bpf_map *map, u64 flags, void *data, u64 size)
4218 * 	Description
4219 * 		Write raw *data* blob into a special BPF perf event held by
4220 * 		*map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf
4221 * 		event must have the following attributes: **PERF_SAMPLE_RAW**
4222 * 		as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and
4223 * 		**PERF_COUNT_SW_BPF_OUTPUT** as **config**.
4224 *
4225 * 		The *flags* are used to indicate the index in *map* for which
4226 * 		the value must be put, masked with **BPF_F_INDEX_MASK**.
4227 * 		Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU**
4228 * 		to indicate that the index of the current CPU core should be
4229 * 		used.
4230 *
4231 * 		The value to write, of *size*, is passed through eBPF stack and
4232 * 		pointed by *data*.
4233 *
4234 * 		*ctx* is a pointer to in-kernel struct sk_buff.
4235 *
4236 * 		This helper is similar to **bpf_perf_event_output**\ () but
4237 * 		restricted to raw_tracepoint bpf programs.
4238 * 	Return
4239 * 		0 on success, or a negative error in case of failure.
4240 *
4241 * long bpf_probe_read_user(void *dst, u32 size, const void *unsafe_ptr)
4242 * 	Description
4243 * 		Safely attempt to read *size* bytes from user space address
4244 * 		*unsafe_ptr* and store the data in *dst*.
4245 * 	Return
4246 * 		0 on success, or a negative error in case of failure.
4247 *
4248 * long bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr)
4249 * 	Description
4250 * 		Safely attempt to read *size* bytes from kernel space address
4251 * 		*unsafe_ptr* and store the data in *dst*.
4252 * 	Return
4253 * 		0 on success, or a negative error in case of failure.
4254 *
4255 * long bpf_probe_read_user_str(void *dst, u32 size, const void *unsafe_ptr)
4256 * 	Description
4257 * 		Copy a NUL terminated string from an unsafe user address
4258 * 		*unsafe_ptr* to *dst*. The *size* should include the
4259 * 		terminating NUL byte. In case the string length is smaller than
4260 * 		*size*, the target is not padded with further NUL bytes. If the
4261 * 		string length is larger than *size*, just *size*-1 bytes are
4262 * 		copied and the last byte is set to NUL.
4263 *
4264 * 		On success, returns the number of bytes that were written,
4265 * 		including the terminal NUL. This makes this helper useful in
4266 * 		tracing programs for reading strings, and more importantly to
4267 * 		get its length at runtime. See the following snippet:
4268 *
4269 * 		::
4270 *
4271 * 			SEC("kprobe/sys_open")
4272 * 			void bpf_sys_open(struct pt_regs *ctx)
4273 * 			{
4274 * 			        char buf[PATHLEN]; // PATHLEN is defined to 256
4275 * 			        int res = bpf_probe_read_user_str(buf, sizeof(buf),
4276 * 				                                  ctx->di);
4277 *
4278 * 				// Consume buf, for example push it to
4279 * 				// userspace via bpf_perf_event_output(); we
4280 * 				// can use res (the string length) as event
4281 * 				// size, after checking its boundaries.
4282 * 			}
4283 *
4284 * 		In comparison, using **bpf_probe_read_user**\ () helper here
4285 * 		instead to read the string would require to estimate the length
4286 * 		at compile time, and would often result in copying more memory
4287 * 		than necessary.
4288 *
4289 * 		Another useful use case is when parsing individual process
4290 * 		arguments or individual environment variables navigating
4291 * 		*current*\ **->mm->arg_start** and *current*\
4292 * 		**->mm->env_start**: using this helper and the return value,
4293 * 		one can quickly iterate at the right offset of the memory area.
4294 * 	Return
4295 * 		On success, the strictly positive length of the output string,
4296 * 		including the trailing NUL character. On error, a negative
4297 * 		value.
4298 *
4299 * long bpf_probe_read_kernel_str(void *dst, u32 size, const void *unsafe_ptr)
4300 * 	Description
4301 * 		Copy a NUL terminated string from an unsafe kernel address *unsafe_ptr*
4302 * 		to *dst*. Same semantics as with **bpf_probe_read_user_str**\ () apply.
4303 * 	Return
4304 * 		On success, the strictly positive length of the string, including
4305 * 		the trailing NUL character. On error, a negative value.
4306 *
4307 * long bpf_tcp_send_ack(void *tp, u32 rcv_nxt)
4308 *	Description
4309 *		Send out a tcp-ack. *tp* is the in-kernel struct **tcp_sock**.
4310 *		*rcv_nxt* is the ack_seq to be sent out.
4311 *	Return
4312 *		0 on success, or a negative error in case of failure.
4313 *
4314 * long bpf_send_signal_thread(u32 sig)
4315 *	Description
4316 *		Send signal *sig* to the thread corresponding to the current task.
4317 *	Return
4318 *		0 on success or successfully queued.
4319 *
4320 *		**-EBUSY** if work queue under nmi is full.
4321 *
4322 *		**-EINVAL** if *sig* is invalid.
4323 *
4324 *		**-EPERM** if no permission to send the *sig*.
4325 *
4326 *		**-EAGAIN** if bpf program can try again.
4327 *
4328 * u64 bpf_jiffies64(void)
4329 *	Description
4330 *		Obtain the 64bit jiffies
4331 *	Return
4332 *		The 64 bit jiffies
4333 *
4334 * long bpf_read_branch_records(struct bpf_perf_event_data *ctx, void *buf, u32 size, u64 flags)
4335 *	Description
4336 *		For an eBPF program attached to a perf event, retrieve the
4337 *		branch records (**struct perf_branch_entry**) associated to *ctx*
4338 *		and store it in the buffer pointed by *buf* up to size
4339 *		*size* bytes.
4340 *	Return
4341 *		On success, number of bytes written to *buf*. On error, a
4342 *		negative value.
4343 *
4344 *		The *flags* can be set to **BPF_F_GET_BRANCH_RECORDS_SIZE** to
4345 *		instead return the number of bytes required to store all the
4346 *		branch entries. If this flag is set, *buf* may be NULL.
4347 *
4348 *		**-EINVAL** if arguments invalid or **size** not a multiple
4349 *		of **sizeof**\ (**struct perf_branch_entry**\ ).
4350 *
4351 *		**-ENOENT** if architecture does not support branch records.
4352 *
4353 * long bpf_get_ns_current_pid_tgid(u64 dev, u64 ino, struct bpf_pidns_info *nsdata, u32 size)
4354 *	Description
4355 *		Returns 0 on success, values for *pid* and *tgid* as seen from the current
4356 *		*namespace* will be returned in *nsdata*.
4357 *	Return
4358 *		0 on success, or one of the following in case of failure:
4359 *
4360 *		**-EINVAL** if dev and inum supplied don't match dev_t and inode number
4361 *              with nsfs of current task, or if dev conversion to dev_t lost high bits.
4362 *
4363 *		**-ENOENT** if pidns does not exists for the current task.
4364 *
4365 * long bpf_xdp_output(void *ctx, struct bpf_map *map, u64 flags, void *data, u64 size)
4366 *	Description
4367 *		Write raw *data* blob into a special BPF perf event held by
4368 *		*map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf
4369 *		event must have the following attributes: **PERF_SAMPLE_RAW**
4370 *		as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and
4371 *		**PERF_COUNT_SW_BPF_OUTPUT** as **config**.
4372 *
4373 *		The *flags* are used to indicate the index in *map* for which
4374 *		the value must be put, masked with **BPF_F_INDEX_MASK**.
4375 *		Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU**
4376 *		to indicate that the index of the current CPU core should be
4377 *		used.
4378 *
4379 *		The value to write, of *size*, is passed through eBPF stack and
4380 *		pointed by *data*.
4381 *
4382 *		*ctx* is a pointer to in-kernel struct xdp_buff.
4383 *
4384 *		This helper is similar to **bpf_perf_eventoutput**\ () but
4385 *		restricted to raw_tracepoint bpf programs.
4386 *	Return
4387 *		0 on success, or a negative error in case of failure.
4388 *
4389 * u64 bpf_get_netns_cookie(void *ctx)
4390 * 	Description
4391 * 		Retrieve the cookie (generated by the kernel) of the network
4392 * 		namespace the input *ctx* is associated with. The network
4393 * 		namespace cookie remains stable for its lifetime and provides
4394 * 		a global identifier that can be assumed unique. If *ctx* is
4395 * 		NULL, then the helper returns the cookie for the initial
4396 * 		network namespace. The cookie itself is very similar to that
4397 * 		of **bpf_get_socket_cookie**\ () helper, but for network
4398 * 		namespaces instead of sockets.
4399 * 	Return
4400 * 		A 8-byte long opaque number.
4401 *
4402 * u64 bpf_get_current_ancestor_cgroup_id(int ancestor_level)
4403 * 	Description
4404 * 		Return id of cgroup v2 that is ancestor of the cgroup associated
4405 * 		with the current task at the *ancestor_level*. The root cgroup
4406 * 		is at *ancestor_level* zero and each step down the hierarchy
4407 * 		increments the level. If *ancestor_level* == level of cgroup
4408 * 		associated with the current task, then return value will be the
4409 * 		same as that of **bpf_get_current_cgroup_id**\ ().
4410 *
4411 * 		The helper is useful to implement policies based on cgroups
4412 * 		that are upper in hierarchy than immediate cgroup associated
4413 * 		with the current task.
4414 *
4415 * 		The format of returned id and helper limitations are same as in
4416 * 		**bpf_get_current_cgroup_id**\ ().
4417 * 	Return
4418 * 		The id is returned or 0 in case the id could not be retrieved.
4419 *
4420 * long bpf_sk_assign(struct sk_buff *skb, void *sk, u64 flags)
4421 *	Description
4422 *		Helper is overloaded depending on BPF program type. This
4423 *		description applies to **BPF_PROG_TYPE_SCHED_CLS** and
4424 *		**BPF_PROG_TYPE_SCHED_ACT** programs.
4425 *
4426 *		Assign the *sk* to the *skb*. When combined with appropriate
4427 *		routing configuration to receive the packet towards the socket,
4428 *		will cause *skb* to be delivered to the specified socket.
4429 *		Subsequent redirection of *skb* via  **bpf_redirect**\ (),
4430 *		**bpf_clone_redirect**\ () or other methods outside of BPF may
4431 *		interfere with successful delivery to the socket.
4432 *
4433 *		This operation is only valid from TC ingress path.
4434 *
4435 *		The *flags* argument must be zero.
4436 *	Return
4437 *		0 on success, or a negative error in case of failure:
4438 *
4439 *		**-EINVAL** if specified *flags* are not supported.
4440 *
4441 *		**-ENOENT** if the socket is unavailable for assignment.
4442 *
4443 *		**-ENETUNREACH** if the socket is unreachable (wrong netns).
4444 *
4445 *		**-EOPNOTSUPP** if the operation is not supported, for example
4446 *		a call from outside of TC ingress.
4447 *
4448 * long bpf_sk_assign(struct bpf_sk_lookup *ctx, struct bpf_sock *sk, u64 flags)
4449 *	Description
4450 *		Helper is overloaded depending on BPF program type. This
4451 *		description applies to **BPF_PROG_TYPE_SK_LOOKUP** programs.
4452 *
4453 *		Select the *sk* as a result of a socket lookup.
4454 *
4455 *		For the operation to succeed passed socket must be compatible
4456 *		with the packet description provided by the *ctx* object.
4457 *
4458 *		L4 protocol (**IPPROTO_TCP** or **IPPROTO_UDP**) must
4459 *		be an exact match. While IP family (**AF_INET** or
4460 *		**AF_INET6**) must be compatible, that is IPv6 sockets
4461 *		that are not v6-only can be selected for IPv4 packets.
4462 *
4463 *		Only TCP listeners and UDP unconnected sockets can be
4464 *		selected. *sk* can also be NULL to reset any previous
4465 *		selection.
4466 *
4467 *		*flags* argument can combination of following values:
4468 *
4469 *		* **BPF_SK_LOOKUP_F_REPLACE** to override the previous
4470 *		  socket selection, potentially done by a BPF program
4471 *		  that ran before us.
4472 *
4473 *		* **BPF_SK_LOOKUP_F_NO_REUSEPORT** to skip
4474 *		  load-balancing within reuseport group for the socket
4475 *		  being selected.
4476 *
4477 *		On success *ctx->sk* will point to the selected socket.
4478 *
4479 *	Return
4480 *		0 on success, or a negative errno in case of failure.
4481 *
4482 *		* **-EAFNOSUPPORT** if socket family (*sk->family*) is
4483 *		  not compatible with packet family (*ctx->family*).
4484 *
4485 *		* **-EEXIST** if socket has been already selected,
4486 *		  potentially by another program, and
4487 *		  **BPF_SK_LOOKUP_F_REPLACE** flag was not specified.
4488 *
4489 *		* **-EINVAL** if unsupported flags were specified.
4490 *
4491 *		* **-EPROTOTYPE** if socket L4 protocol
4492 *		  (*sk->protocol*) doesn't match packet protocol
4493 *		  (*ctx->protocol*).
4494 *
4495 *		* **-ESOCKTNOSUPPORT** if socket is not in allowed
4496 *		  state (TCP listening or UDP unconnected).
4497 *
4498 * u64 bpf_ktime_get_boot_ns(void)
4499 * 	Description
4500 * 		Return the time elapsed since system boot, in nanoseconds.
4501 * 		Does include the time the system was suspended.
4502 * 		See: **clock_gettime**\ (**CLOCK_BOOTTIME**)
4503 * 	Return
4504 * 		Current *ktime*.
4505 *
4506 * long bpf_seq_printf(struct seq_file *m, const char *fmt, u32 fmt_size, const void *data, u32 data_len)
4507 * 	Description
4508 * 		**bpf_seq_printf**\ () uses seq_file **seq_printf**\ () to print
4509 * 		out the format string.
4510 * 		The *m* represents the seq_file. The *fmt* and *fmt_size* are for
4511 * 		the format string itself. The *data* and *data_len* are format string
4512 * 		arguments. The *data* are a **u64** array and corresponding format string
4513 * 		values are stored in the array. For strings and pointers where pointees
4514 * 		are accessed, only the pointer values are stored in the *data* array.
4515 * 		The *data_len* is the size of *data* in bytes - must be a multiple of 8.
4516 *
4517 *		Formats **%s**, **%p{i,I}{4,6}** requires to read kernel memory.
4518 *		Reading kernel memory may fail due to either invalid address or
4519 *		valid address but requiring a major memory fault. If reading kernel memory
4520 *		fails, the string for **%s** will be an empty string, and the ip
4521 *		address for **%p{i,I}{4,6}** will be 0. Not returning error to
4522 *		bpf program is consistent with what **bpf_trace_printk**\ () does for now.
4523 * 	Return
4524 * 		0 on success, or a negative error in case of failure:
4525 *
4526 *		**-EBUSY** if per-CPU memory copy buffer is busy, can try again
4527 *		by returning 1 from bpf program.
4528 *
4529 *		**-EINVAL** if arguments are invalid, or if *fmt* is invalid/unsupported.
4530 *
4531 *		**-E2BIG** if *fmt* contains too many format specifiers.
4532 *
4533 *		**-EOVERFLOW** if an overflow happened: The same object will be tried again.
4534 *
4535 * long bpf_seq_write(struct seq_file *m, const void *data, u32 len)
4536 * 	Description
4537 * 		**bpf_seq_write**\ () uses seq_file **seq_write**\ () to write the data.
4538 * 		The *m* represents the seq_file. The *data* and *len* represent the
4539 * 		data to write in bytes.
4540 * 	Return
4541 * 		0 on success, or a negative error in case of failure:
4542 *
4543 *		**-EOVERFLOW** if an overflow happened: The same object will be tried again.
4544 *
4545 * u64 bpf_sk_cgroup_id(void *sk)
4546 *	Description
4547 *		Return the cgroup v2 id of the socket *sk*.
4548 *
4549 *		*sk* must be a non-**NULL** pointer to a socket, e.g. one
4550 *		returned from **bpf_sk_lookup_xxx**\ (),
4551 *		**bpf_sk_fullsock**\ (), etc. The format of returned id is
4552 *		same as in **bpf_skb_cgroup_id**\ ().
4553 *
4554 *		This helper is available only if the kernel was compiled with
4555 *		the **CONFIG_SOCK_CGROUP_DATA** configuration option.
4556 *	Return
4557 *		The id is returned or 0 in case the id could not be retrieved.
4558 *
4559 * u64 bpf_sk_ancestor_cgroup_id(void *sk, int ancestor_level)
4560 *	Description
4561 *		Return id of cgroup v2 that is ancestor of cgroup associated
4562 *		with the *sk* at the *ancestor_level*.  The root cgroup is at
4563 *		*ancestor_level* zero and each step down the hierarchy
4564 *		increments the level. If *ancestor_level* == level of cgroup
4565 *		associated with *sk*, then return value will be same as that
4566 *		of **bpf_sk_cgroup_id**\ ().
4567 *
4568 *		The helper is useful to implement policies based on cgroups
4569 *		that are upper in hierarchy than immediate cgroup associated
4570 *		with *sk*.
4571 *
4572 *		The format of returned id and helper limitations are same as in
4573 *		**bpf_sk_cgroup_id**\ ().
4574 *	Return
4575 *		The id is returned or 0 in case the id could not be retrieved.
4576 *
4577 * long bpf_ringbuf_output(void *ringbuf, void *data, u64 size, u64 flags)
4578 * 	Description
4579 * 		Copy *size* bytes from *data* into a ring buffer *ringbuf*.
4580 * 		If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification
4581 * 		of new data availability is sent.
4582 * 		If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification
4583 * 		of new data availability is sent unconditionally.
4584 * 		If **0** is specified in *flags*, an adaptive notification
4585 * 		of new data availability is sent.
4586 *
4587 * 		An adaptive notification is a notification sent whenever the user-space
4588 * 		process has caught up and consumed all available payloads. In case the user-space
4589 * 		process is still processing a previous payload, then no notification is needed
4590 * 		as it will process the newly added payload automatically.
4591 * 	Return
4592 * 		0 on success, or a negative error in case of failure.
4593 *
4594 * void *bpf_ringbuf_reserve(void *ringbuf, u64 size, u64 flags)
4595 * 	Description
4596 * 		Reserve *size* bytes of payload in a ring buffer *ringbuf*.
4597 * 		*flags* must be 0.
4598 * 	Return
4599 * 		Valid pointer with *size* bytes of memory available; NULL,
4600 * 		otherwise.
4601 *
4602 * void bpf_ringbuf_submit(void *data, u64 flags)
4603 * 	Description
4604 * 		Submit reserved ring buffer sample, pointed to by *data*.
4605 * 		If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification
4606 * 		of new data availability is sent.
4607 * 		If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification
4608 * 		of new data availability is sent unconditionally.
4609 * 		If **0** is specified in *flags*, an adaptive notification
4610 * 		of new data availability is sent.
4611 *
4612 * 		See 'bpf_ringbuf_output()' for the definition of adaptive notification.
4613 * 	Return
4614 * 		Nothing. Always succeeds.
4615 *
4616 * void bpf_ringbuf_discard(void *data, u64 flags)
4617 * 	Description
4618 * 		Discard reserved ring buffer sample, pointed to by *data*.
4619 * 		If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification
4620 * 		of new data availability is sent.
4621 * 		If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification
4622 * 		of new data availability is sent unconditionally.
4623 * 		If **0** is specified in *flags*, an adaptive notification
4624 * 		of new data availability is sent.
4625 *
4626 * 		See 'bpf_ringbuf_output()' for the definition of adaptive notification.
4627 * 	Return
4628 * 		Nothing. Always succeeds.
4629 *
4630 * u64 bpf_ringbuf_query(void *ringbuf, u64 flags)
4631 *	Description
4632 *		Query various characteristics of provided ring buffer. What
4633 *		exactly is queries is determined by *flags*:
4634 *
4635 *		* **BPF_RB_AVAIL_DATA**: Amount of data not yet consumed.
4636 *		* **BPF_RB_RING_SIZE**: The size of ring buffer.
4637 *		* **BPF_RB_CONS_POS**: Consumer position (can wrap around).
4638 *		* **BPF_RB_PROD_POS**: Producer(s) position (can wrap around).
4639 *
4640 *		Data returned is just a momentary snapshot of actual values
4641 *		and could be inaccurate, so this facility should be used to
4642 *		power heuristics and for reporting, not to make 100% correct
4643 *		calculation.
4644 *	Return
4645 *		Requested value, or 0, if *flags* are not recognized.
4646 *
4647 * long bpf_csum_level(struct sk_buff *skb, u64 level)
4648 * 	Description
4649 * 		Change the skbs checksum level by one layer up or down, or
4650 * 		reset it entirely to none in order to have the stack perform
4651 * 		checksum validation. The level is applicable to the following
4652 * 		protocols: TCP, UDP, GRE, SCTP, FCOE. For example, a decap of
4653 * 		| ETH | IP | UDP | GUE | IP | TCP | into | ETH | IP | TCP |
4654 * 		through **bpf_skb_adjust_room**\ () helper with passing in
4655 * 		**BPF_F_ADJ_ROOM_NO_CSUM_RESET** flag would require one	call
4656 * 		to **bpf_csum_level**\ () with **BPF_CSUM_LEVEL_DEC** since
4657 * 		the UDP header is removed. Similarly, an encap of the latter
4658 * 		into the former could be accompanied by a helper call to
4659 * 		**bpf_csum_level**\ () with **BPF_CSUM_LEVEL_INC** if the
4660 * 		skb is still intended to be processed in higher layers of the
4661 * 		stack instead of just egressing at tc.
4662 *
4663 * 		There are three supported level settings at this time:
4664 *
4665 * 		* **BPF_CSUM_LEVEL_INC**: Increases skb->csum_level for skbs
4666 * 		  with CHECKSUM_UNNECESSARY.
4667 * 		* **BPF_CSUM_LEVEL_DEC**: Decreases skb->csum_level for skbs
4668 * 		  with CHECKSUM_UNNECESSARY.
4669 * 		* **BPF_CSUM_LEVEL_RESET**: Resets skb->csum_level to 0 and
4670 * 		  sets CHECKSUM_NONE to force checksum validation by the stack.
4671 * 		* **BPF_CSUM_LEVEL_QUERY**: No-op, returns the current
4672 * 		  skb->csum_level.
4673 * 	Return
4674 * 		0 on success, or a negative error in case of failure. In the
4675 * 		case of **BPF_CSUM_LEVEL_QUERY**, the current skb->csum_level
4676 * 		is returned or the error code -EACCES in case the skb is not
4677 * 		subject to CHECKSUM_UNNECESSARY.
4678 *
4679 * struct tcp6_sock *bpf_skc_to_tcp6_sock(void *sk)
4680 *	Description
4681 *		Dynamically cast a *sk* pointer to a *tcp6_sock* pointer.
4682 *	Return
4683 *		*sk* if casting is valid, or **NULL** otherwise.
4684 *
4685 * struct tcp_sock *bpf_skc_to_tcp_sock(void *sk)
4686 *	Description
4687 *		Dynamically cast a *sk* pointer to a *tcp_sock* pointer.
4688 *	Return
4689 *		*sk* if casting is valid, or **NULL** otherwise.
4690 *
4691 * struct tcp_timewait_sock *bpf_skc_to_tcp_timewait_sock(void *sk)
4692 * 	Description
4693 *		Dynamically cast a *sk* pointer to a *tcp_timewait_sock* pointer.
4694 *	Return
4695 *		*sk* if casting is valid, or **NULL** otherwise.
4696 *
4697 * struct tcp_request_sock *bpf_skc_to_tcp_request_sock(void *sk)
4698 * 	Description
4699 *		Dynamically cast a *sk* pointer to a *tcp_request_sock* pointer.
4700 *	Return
4701 *		*sk* if casting is valid, or **NULL** otherwise.
4702 *
4703 * struct udp6_sock *bpf_skc_to_udp6_sock(void *sk)
4704 * 	Description
4705 *		Dynamically cast a *sk* pointer to a *udp6_sock* pointer.
4706 *	Return
4707 *		*sk* if casting is valid, or **NULL** otherwise.
4708 *
4709 * long bpf_get_task_stack(struct task_struct *task, void *buf, u32 size, u64 flags)
4710 *	Description
4711 *		Return a user or a kernel stack in bpf program provided buffer.
4712 *		Note: the user stack will only be populated if the *task* is
4713 *		the current task; all other tasks will return -EOPNOTSUPP.
4714 *		To achieve this, the helper needs *task*, which is a valid
4715 *		pointer to **struct task_struct**. To store the stacktrace, the
4716 *		bpf program provides *buf* with a nonnegative *size*.
4717 *
4718 *		The last argument, *flags*, holds the number of stack frames to
4719 *		skip (from 0 to 255), masked with
4720 *		**BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set
4721 *		the following flags:
4722 *
4723 *		**BPF_F_USER_STACK**
4724 *			Collect a user space stack instead of a kernel stack.
4725 *			The *task* must be the current task.
4726 *		**BPF_F_USER_BUILD_ID**
4727 *			Collect buildid+offset instead of ips for user stack,
4728 *			only valid if **BPF_F_USER_STACK** is also specified.
4729 *
4730 *		**bpf_get_task_stack**\ () can collect up to
4731 *		**PERF_MAX_STACK_DEPTH** both kernel and user frames, subject
4732 *		to sufficient large buffer size. Note that
4733 *		this limit can be controlled with the **sysctl** program, and
4734 *		that it should be manually increased in order to profile long
4735 *		user stacks (such as stacks for Java programs). To do so, use:
4736 *
4737 *		::
4738 *
4739 *			# sysctl kernel.perf_event_max_stack=<new value>
4740 *	Return
4741 * 		The non-negative copied *buf* length equal to or less than
4742 * 		*size* on success, or a negative error in case of failure.
4743 *
4744 * long bpf_load_hdr_opt(struct bpf_sock_ops *skops, void *searchby_res, u32 len, u64 flags)
4745 *	Description
4746 *		Load header option.  Support reading a particular TCP header
4747 *		option for bpf program (**BPF_PROG_TYPE_SOCK_OPS**).
4748 *
4749 *		If *flags* is 0, it will search the option from the
4750 *		*skops*\ **->skb_data**.  The comment in **struct bpf_sock_ops**
4751 *		has details on what skb_data contains under different
4752 *		*skops*\ **->op**.
4753 *
4754 *		The first byte of the *searchby_res* specifies the
4755 *		kind that it wants to search.
4756 *
4757 *		If the searching kind is an experimental kind
4758 *		(i.e. 253 or 254 according to RFC6994).  It also
4759 *		needs to specify the "magic" which is either
4760 *		2 bytes or 4 bytes.  It then also needs to
4761 *		specify the size of the magic by using
4762 *		the 2nd byte which is "kind-length" of a TCP
4763 *		header option and the "kind-length" also
4764 *		includes the first 2 bytes "kind" and "kind-length"
4765 *		itself as a normal TCP header option also does.
4766 *
4767 *		For example, to search experimental kind 254 with
4768 *		2 byte magic 0xeB9F, the searchby_res should be
4769 *		[ 254, 4, 0xeB, 0x9F, 0, 0, .... 0 ].
4770 *
4771 *		To search for the standard window scale option (3),
4772 *		the *searchby_res* should be [ 3, 0, 0, .... 0 ].
4773 *		Note, kind-length must be 0 for regular option.
4774 *
4775 *		Searching for No-Op (0) and End-of-Option-List (1) are
4776 *		not supported.
4777 *
4778 *		*len* must be at least 2 bytes which is the minimal size
4779 *		of a header option.
4780 *
4781 *		Supported flags:
4782 *
4783 *		* **BPF_LOAD_HDR_OPT_TCP_SYN** to search from the
4784 *		  saved_syn packet or the just-received syn packet.
4785 *
4786 *	Return
4787 *		> 0 when found, the header option is copied to *searchby_res*.
4788 *		The return value is the total length copied. On failure, a
4789 *		negative error code is returned:
4790 *
4791 *		**-EINVAL** if a parameter is invalid.
4792 *
4793 *		**-ENOMSG** if the option is not found.
4794 *
4795 *		**-ENOENT** if no syn packet is available when
4796 *		**BPF_LOAD_HDR_OPT_TCP_SYN** is used.
4797 *
4798 *		**-ENOSPC** if there is not enough space.  Only *len* number of
4799 *		bytes are copied.
4800 *
4801 *		**-EFAULT** on failure to parse the header options in the
4802 *		packet.
4803 *
4804 *		**-EPERM** if the helper cannot be used under the current
4805 *		*skops*\ **->op**.
4806 *
4807 * long bpf_store_hdr_opt(struct bpf_sock_ops *skops, const void *from, u32 len, u64 flags)
4808 *	Description
4809 *		Store header option.  The data will be copied
4810 *		from buffer *from* with length *len* to the TCP header.
4811 *
4812 *		The buffer *from* should have the whole option that
4813 *		includes the kind, kind-length, and the actual
4814 *		option data.  The *len* must be at least kind-length
4815 *		long.  The kind-length does not have to be 4 byte
4816 *		aligned.  The kernel will take care of the padding
4817 *		and setting the 4 bytes aligned value to th->doff.
4818 *
4819 *		This helper will check for duplicated option
4820 *		by searching the same option in the outgoing skb.
4821 *
4822 *		This helper can only be called during
4823 *		**BPF_SOCK_OPS_WRITE_HDR_OPT_CB**.
4824 *
4825 *	Return
4826 *		0 on success, or negative error in case of failure:
4827 *
4828 *		**-EINVAL** If param is invalid.
4829 *
4830 *		**-ENOSPC** if there is not enough space in the header.
4831 *		Nothing has been written
4832 *
4833 *		**-EEXIST** if the option already exists.
4834 *
4835 *		**-EFAULT** on failure to parse the existing header options.
4836 *
4837 *		**-EPERM** if the helper cannot be used under the current
4838 *		*skops*\ **->op**.
4839 *
4840 * long bpf_reserve_hdr_opt(struct bpf_sock_ops *skops, u32 len, u64 flags)
4841 *	Description
4842 *		Reserve *len* bytes for the bpf header option.  The
4843 *		space will be used by **bpf_store_hdr_opt**\ () later in
4844 *		**BPF_SOCK_OPS_WRITE_HDR_OPT_CB**.
4845 *
4846 *		If **bpf_reserve_hdr_opt**\ () is called multiple times,
4847 *		the total number of bytes will be reserved.
4848 *
4849 *		This helper can only be called during
4850 *		**BPF_SOCK_OPS_HDR_OPT_LEN_CB**.
4851 *
4852 *	Return
4853 *		0 on success, or negative error in case of failure:
4854 *
4855 *		**-EINVAL** if a parameter is invalid.
4856 *
4857 *		**-ENOSPC** if there is not enough space in the header.
4858 *
4859 *		**-EPERM** if the helper cannot be used under the current
4860 *		*skops*\ **->op**.
4861 *
4862 * void *bpf_inode_storage_get(struct bpf_map *map, void *inode, void *value, u64 flags)
4863 *	Description
4864 *		Get a bpf_local_storage from an *inode*.
4865 *
4866 *		Logically, it could be thought of as getting the value from
4867 *		a *map* with *inode* as the **key**.  From this
4868 *		perspective,  the usage is not much different from
4869 *		**bpf_map_lookup_elem**\ (*map*, **&**\ *inode*) except this
4870 *		helper enforces the key must be an inode and the map must also
4871 *		be a **BPF_MAP_TYPE_INODE_STORAGE**.
4872 *
4873 *		Underneath, the value is stored locally at *inode* instead of
4874 *		the *map*.  The *map* is used as the bpf-local-storage
4875 *		"type". The bpf-local-storage "type" (i.e. the *map*) is
4876 *		searched against all bpf_local_storage residing at *inode*.
4877 *
4878 *		An optional *flags* (**BPF_LOCAL_STORAGE_GET_F_CREATE**) can be
4879 *		used such that a new bpf_local_storage will be
4880 *		created if one does not exist.  *value* can be used
4881 *		together with **BPF_LOCAL_STORAGE_GET_F_CREATE** to specify
4882 *		the initial value of a bpf_local_storage.  If *value* is
4883 *		**NULL**, the new bpf_local_storage will be zero initialized.
4884 *	Return
4885 *		A bpf_local_storage pointer is returned on success.
4886 *
4887 *		**NULL** if not found or there was an error in adding
4888 *		a new bpf_local_storage.
4889 *
4890 * int bpf_inode_storage_delete(struct bpf_map *map, void *inode)
4891 *	Description
4892 *		Delete a bpf_local_storage from an *inode*.
4893 *	Return
4894 *		0 on success.
4895 *
4896 *		**-ENOENT** if the bpf_local_storage cannot be found.
4897 *
4898 * long bpf_d_path(const struct path *path, char *buf, u32 sz)
4899 *	Description
4900 *		Return full path for given **struct path** object, which
4901 *		needs to be the kernel BTF *path* object. The path is
4902 *		returned in the provided buffer *buf* of size *sz* and
4903 *		is zero terminated.
4904 *
4905 *	Return
4906 *		On success, the strictly positive length of the string,
4907 *		including the trailing NUL character. On error, a negative
4908 *		value.
4909 *
4910 * long bpf_copy_from_user(void *dst, u32 size, const void *user_ptr)
4911 * 	Description
4912 * 		Read *size* bytes from user space address *user_ptr* and store
4913 * 		the data in *dst*. This is a wrapper of **copy_from_user**\ ().
4914 * 	Return
4915 * 		0 on success, or a negative error in case of failure.
4916 *
4917 * long bpf_snprintf_btf(char *str, u32 str_size, struct btf_ptr *ptr, u32 btf_ptr_size, u64 flags)
4918 *	Description
4919 *		Use BTF to store a string representation of *ptr*->ptr in *str*,
4920 *		using *ptr*->type_id.  This value should specify the type
4921 *		that *ptr*->ptr points to. LLVM __builtin_btf_type_id(type, 1)
4922 *		can be used to look up vmlinux BTF type ids. Traversing the
4923 *		data structure using BTF, the type information and values are
4924 *		stored in the first *str_size* - 1 bytes of *str*.  Safe copy of
4925 *		the pointer data is carried out to avoid kernel crashes during
4926 *		operation.  Smaller types can use string space on the stack;
4927 *		larger programs can use map data to store the string
4928 *		representation.
4929 *
4930 *		The string can be subsequently shared with userspace via
4931 *		bpf_perf_event_output() or ring buffer interfaces.
4932 *		bpf_trace_printk() is to be avoided as it places too small
4933 *		a limit on string size to be useful.
4934 *
4935 *		*flags* is a combination of
4936 *
4937 *		**BTF_F_COMPACT**
4938 *			no formatting around type information
4939 *		**BTF_F_NONAME**
4940 *			no struct/union member names/types
4941 *		**BTF_F_PTR_RAW**
4942 *			show raw (unobfuscated) pointer values;
4943 *			equivalent to printk specifier %px.
4944 *		**BTF_F_ZERO**
4945 *			show zero-valued struct/union members; they
4946 *			are not displayed by default
4947 *
4948 *	Return
4949 *		The number of bytes that were written (or would have been
4950 *		written if output had to be truncated due to string size),
4951 *		or a negative error in cases of failure.
4952 *
4953 * long bpf_seq_printf_btf(struct seq_file *m, struct btf_ptr *ptr, u32 ptr_size, u64 flags)
4954 *	Description
4955 *		Use BTF to write to seq_write a string representation of
4956 *		*ptr*->ptr, using *ptr*->type_id as per bpf_snprintf_btf().
4957 *		*flags* are identical to those used for bpf_snprintf_btf.
4958 *	Return
4959 *		0 on success or a negative error in case of failure.
4960 *
4961 * u64 bpf_skb_cgroup_classid(struct sk_buff *skb)
4962 * 	Description
4963 * 		See **bpf_get_cgroup_classid**\ () for the main description.
4964 * 		This helper differs from **bpf_get_cgroup_classid**\ () in that
4965 * 		the cgroup v1 net_cls class is retrieved only from the *skb*'s
4966 * 		associated socket instead of the current process.
4967 * 	Return
4968 * 		The id is returned or 0 in case the id could not be retrieved.
4969 *
4970 * long bpf_redirect_neigh(u32 ifindex, struct bpf_redir_neigh *params, int plen, u64 flags)
4971 * 	Description
4972 * 		Redirect the packet to another net device of index *ifindex*
4973 * 		and fill in L2 addresses from neighboring subsystem. This helper
4974 * 		is somewhat similar to **bpf_redirect**\ (), except that it
4975 * 		populates L2 addresses as well, meaning, internally, the helper
4976 * 		relies on the neighbor lookup for the L2 address of the nexthop.
4977 *
4978 * 		The helper will perform a FIB lookup based on the skb's
4979 * 		networking header to get the address of the next hop, unless
4980 * 		this is supplied by the caller in the *params* argument. The
4981 * 		*plen* argument indicates the len of *params* and should be set
4982 * 		to 0 if *params* is NULL.
4983 *
4984 * 		The *flags* argument is reserved and must be 0. The helper is
4985 * 		currently only supported for tc BPF program types, and enabled
4986 * 		for IPv4 and IPv6 protocols.
4987 * 	Return
4988 * 		The helper returns **TC_ACT_REDIRECT** on success or
4989 * 		**TC_ACT_SHOT** on error.
4990 *
4991 * void *bpf_per_cpu_ptr(const void *percpu_ptr, u32 cpu)
4992 *     Description
4993 *             Take a pointer to a percpu ksym, *percpu_ptr*, and return a
4994 *             pointer to the percpu kernel variable on *cpu*. A ksym is an
4995 *             extern variable decorated with '__ksym'. For ksym, there is a
4996 *             global var (either static or global) defined of the same name
4997 *             in the kernel. The ksym is percpu if the global var is percpu.
4998 *             The returned pointer points to the global percpu var on *cpu*.
4999 *
5000 *             bpf_per_cpu_ptr() has the same semantic as per_cpu_ptr() in the
5001 *             kernel, except that bpf_per_cpu_ptr() may return NULL. This
5002 *             happens if *cpu* is larger than nr_cpu_ids. The caller of
5003 *             bpf_per_cpu_ptr() must check the returned value.
5004 *     Return
5005 *             A pointer pointing to the kernel percpu variable on *cpu*, or
5006 *             NULL, if *cpu* is invalid.
5007 *
5008 * void *bpf_this_cpu_ptr(const void *percpu_ptr)
5009 *	Description
5010 *		Take a pointer to a percpu ksym, *percpu_ptr*, and return a
5011 *		pointer to the percpu kernel variable on this cpu. See the
5012 *		description of 'ksym' in **bpf_per_cpu_ptr**\ ().
5013 *
5014 *		bpf_this_cpu_ptr() has the same semantic as this_cpu_ptr() in
5015 *		the kernel. Different from **bpf_per_cpu_ptr**\ (), it would
5016 *		never return NULL.
5017 *	Return
5018 *		A pointer pointing to the kernel percpu variable on this cpu.
5019 *
5020 * long bpf_redirect_peer(u32 ifindex, u64 flags)
5021 * 	Description
5022 * 		Redirect the packet to another net device of index *ifindex*.
5023 * 		This helper is somewhat similar to **bpf_redirect**\ (), except
5024 * 		that the redirection happens to the *ifindex*' peer device and
5025 * 		the netns switch takes place from ingress to ingress without
5026 * 		going through the CPU's backlog queue.
5027 *
5028 * 		*skb*\ **->mark** and *skb*\ **->tstamp** are not cleared during
5029 * 		the netns switch.
5030 *
5031 * 		The *flags* argument is reserved and must be 0. The helper is
5032 * 		currently only supported for tc BPF program types at the
5033 * 		ingress hook and for veth and netkit target device types. The
5034 * 		peer device must reside in a different network namespace.
5035 * 	Return
5036 * 		The helper returns **TC_ACT_REDIRECT** on success or
5037 * 		**TC_ACT_SHOT** on error.
5038 *
5039 * void *bpf_task_storage_get(struct bpf_map *map, struct task_struct *task, void *value, u64 flags)
5040 *	Description
5041 *		Get a bpf_local_storage from the *task*.
5042 *
5043 *		Logically, it could be thought of as getting the value from
5044 *		a *map* with *task* as the **key**.  From this
5045 *		perspective,  the usage is not much different from
5046 *		**bpf_map_lookup_elem**\ (*map*, **&**\ *task*) except this
5047 *		helper enforces the key must be a task_struct and the map must also
5048 *		be a **BPF_MAP_TYPE_TASK_STORAGE**.
5049 *
5050 *		Underneath, the value is stored locally at *task* instead of
5051 *		the *map*.  The *map* is used as the bpf-local-storage
5052 *		"type". The bpf-local-storage "type" (i.e. the *map*) is
5053 *		searched against all bpf_local_storage residing at *task*.
5054 *
5055 *		An optional *flags* (**BPF_LOCAL_STORAGE_GET_F_CREATE**) can be
5056 *		used such that a new bpf_local_storage will be
5057 *		created if one does not exist.  *value* can be used
5058 *		together with **BPF_LOCAL_STORAGE_GET_F_CREATE** to specify
5059 *		the initial value of a bpf_local_storage.  If *value* is
5060 *		**NULL**, the new bpf_local_storage will be zero initialized.
5061 *	Return
5062 *		A bpf_local_storage pointer is returned on success.
5063 *
5064 *		**NULL** if not found or there was an error in adding
5065 *		a new bpf_local_storage.
5066 *
5067 * long bpf_task_storage_delete(struct bpf_map *map, struct task_struct *task)
5068 *	Description
5069 *		Delete a bpf_local_storage from a *task*.
5070 *	Return
5071 *		0 on success.
5072 *
5073 *		**-ENOENT** if the bpf_local_storage cannot be found.
5074 *
5075 * struct task_struct *bpf_get_current_task_btf(void)
5076 *	Description
5077 *		Return a BTF pointer to the "current" task.
5078 *		This pointer can also be used in helpers that accept an
5079 *		*ARG_PTR_TO_BTF_ID* of type *task_struct*.
5080 *	Return
5081 *		Pointer to the current task.
5082 *
5083 * long bpf_bprm_opts_set(struct linux_binprm *bprm, u64 flags)
5084 *	Description
5085 *		Set or clear certain options on *bprm*:
5086 *
5087 *		**BPF_F_BPRM_SECUREEXEC** Set the secureexec bit
5088 *		which sets the **AT_SECURE** auxv for glibc. The bit
5089 *		is cleared if the flag is not specified.
5090 *	Return
5091 *		**-EINVAL** if invalid *flags* are passed, zero otherwise.
5092 *
5093 * u64 bpf_ktime_get_coarse_ns(void)
5094 * 	Description
5095 * 		Return a coarse-grained version of the time elapsed since
5096 * 		system boot, in nanoseconds. Does not include time the system
5097 * 		was suspended.
5098 *
5099 * 		See: **clock_gettime**\ (**CLOCK_MONOTONIC_COARSE**)
5100 * 	Return
5101 * 		Current *ktime*.
5102 *
5103 * long bpf_ima_inode_hash(struct inode *inode, void *dst, u32 size)
5104 *	Description
5105 *		Returns the stored IMA hash of the *inode* (if it's available).
5106 *		If the hash is larger than *size*, then only *size*
5107 *		bytes will be copied to *dst*
5108 *	Return
5109 *		The **hash_algo** is returned on success,
5110 *		**-EOPNOTSUPP** if IMA is disabled or **-EINVAL** if
5111 *		invalid arguments are passed.
5112 *
5113 * struct socket *bpf_sock_from_file(struct file *file)
5114 *	Description
5115 *		If the given file represents a socket, returns the associated
5116 *		socket.
5117 *	Return
5118 *		A pointer to a struct socket on success or NULL if the file is
5119 *		not a socket.
5120 *
5121 * long bpf_check_mtu(void *ctx, u32 ifindex, u32 *mtu_len, s32 len_diff, u64 flags)
5122 *	Description
5123 *		Check packet size against exceeding MTU of net device (based
5124 *		on *ifindex*).  This helper will likely be used in combination
5125 *		with helpers that adjust/change the packet size.
5126 *
5127 *		The argument *len_diff* can be used for querying with a planned
5128 *		size change. This allows to check MTU prior to changing packet
5129 *		ctx. Providing a *len_diff* adjustment that is larger than the
5130 *		actual packet size (resulting in negative packet size) will in
5131 *		principle not exceed the MTU, which is why it is not considered
5132 *		a failure.  Other BPF helpers are needed for performing the
5133 *		planned size change; therefore the responsibility for catching
5134 *		a negative packet size belongs in those helpers.
5135 *
5136 *		Specifying *ifindex* zero means the MTU check is performed
5137 *		against the current net device.  This is practical if this isn't
5138 *		used prior to redirect.
5139 *
5140 *		On input *mtu_len* must be a valid pointer, else verifier will
5141 *		reject BPF program.  If the value *mtu_len* is initialized to
5142 *		zero then the ctx packet size is use.  When value *mtu_len* is
5143 *		provided as input this specify the L3 length that the MTU check
5144 *		is done against. Remember XDP and TC length operate at L2, but
5145 *		this value is L3 as this correlate to MTU and IP-header tot_len
5146 *		values which are L3 (similar behavior as bpf_fib_lookup).
5147 *
5148 *		The Linux kernel route table can configure MTUs on a more
5149 *		specific per route level, which is not provided by this helper.
5150 *		For route level MTU checks use the **bpf_fib_lookup**\ ()
5151 *		helper.
5152 *
5153 *		*ctx* is either **struct xdp_md** for XDP programs or
5154 *		**struct sk_buff** for tc cls_act programs.
5155 *
5156 *		The *flags* argument can be a combination of one or more of the
5157 *		following values:
5158 *
5159 *		**BPF_MTU_CHK_SEGS**
5160 *			This flag will only works for *ctx* **struct sk_buff**.
5161 *			If packet context contains extra packet segment buffers
5162 *			(often knows as GSO skb), then MTU check is harder to
5163 *			check at this point, because in transmit path it is
5164 *			possible for the skb packet to get re-segmented
5165 *			(depending on net device features).  This could still be
5166 *			a MTU violation, so this flag enables performing MTU
5167 *			check against segments, with a different violation
5168 *			return code to tell it apart. Check cannot use len_diff.
5169 *
5170 *		On return *mtu_len* pointer contains the MTU value of the net
5171 *		device.  Remember the net device configured MTU is the L3 size,
5172 *		which is returned here and XDP and TC length operate at L2.
5173 *		Helper take this into account for you, but remember when using
5174 *		MTU value in your BPF-code.
5175 *
5176 *	Return
5177 *		* 0 on success, and populate MTU value in *mtu_len* pointer.
5178 *
5179 *		* < 0 if any input argument is invalid (*mtu_len* not updated)
5180 *
5181 *		MTU violations return positive values, but also populate MTU
5182 *		value in *mtu_len* pointer, as this can be needed for
5183 *		implementing PMTU handing:
5184 *
5185 *		* **BPF_MTU_CHK_RET_FRAG_NEEDED**
5186 *		* **BPF_MTU_CHK_RET_SEGS_TOOBIG**
5187 *
5188 * long bpf_for_each_map_elem(struct bpf_map *map, void *callback_fn, void *callback_ctx, u64 flags)
5189 *	Description
5190 *		For each element in **map**, call **callback_fn** function with
5191 *		**map**, **callback_ctx** and other map-specific parameters.
5192 *		The **callback_fn** should be a static function and
5193 *		the **callback_ctx** should be a pointer to the stack.
5194 *		The **flags** is used to control certain aspects of the helper.
5195 *		Currently, the **flags** must be 0.
5196 *
5197 *		The following are a list of supported map types and their
5198 *		respective expected callback signatures:
5199 *
5200 *		BPF_MAP_TYPE_HASH, BPF_MAP_TYPE_PERCPU_HASH,
5201 *		BPF_MAP_TYPE_LRU_HASH, BPF_MAP_TYPE_LRU_PERCPU_HASH,
5202 *		BPF_MAP_TYPE_ARRAY, BPF_MAP_TYPE_PERCPU_ARRAY
5203 *
5204 *		long (\*callback_fn)(struct bpf_map \*map, const void \*key, void \*value, void \*ctx);
5205 *
5206 *		For per_cpu maps, the map_value is the value on the cpu where the
5207 *		bpf_prog is running.
5208 *
5209 *		If **callback_fn** return 0, the helper will continue to the next
5210 *		element. If return value is 1, the helper will skip the rest of
5211 *		elements and return. Other return values are not used now.
5212 *
5213 *	Return
5214 *		The number of traversed map elements for success, **-EINVAL** for
5215 *		invalid **flags**.
5216 *
5217 * long bpf_snprintf(char *str, u32 str_size, const char *fmt, u64 *data, u32 data_len)
5218 *	Description
5219 *		Outputs a string into the **str** buffer of size **str_size**
5220 *		based on a format string stored in a read-only map pointed by
5221 *		**fmt**.
5222 *
5223 *		Each format specifier in **fmt** corresponds to one u64 element
5224 *		in the **data** array. For strings and pointers where pointees
5225 *		are accessed, only the pointer values are stored in the *data*
5226 *		array. The *data_len* is the size of *data* in bytes - must be
5227 *		a multiple of 8.
5228 *
5229 *		Formats **%s** and **%p{i,I}{4,6}** require to read kernel
5230 *		memory. Reading kernel memory may fail due to either invalid
5231 *		address or valid address but requiring a major memory fault. If
5232 *		reading kernel memory fails, the string for **%s** will be an
5233 *		empty string, and the ip address for **%p{i,I}{4,6}** will be 0.
5234 *		Not returning error to bpf program is consistent with what
5235 *		**bpf_trace_printk**\ () does for now.
5236 *
5237 *	Return
5238 *		The strictly positive length of the formatted string, including
5239 *		the trailing zero character. If the return value is greater than
5240 *		**str_size**, **str** contains a truncated string, guaranteed to
5241 *		be zero-terminated except when **str_size** is 0.
5242 *
5243 *		Or **-EBUSY** if the per-CPU memory copy buffer is busy.
5244 *
5245 * long bpf_sys_bpf(u32 cmd, void *attr, u32 attr_size)
5246 * 	Description
5247 * 		Execute bpf syscall with given arguments.
5248 * 	Return
5249 * 		A syscall result.
5250 *
5251 * long bpf_btf_find_by_name_kind(char *name, int name_sz, u32 kind, int flags)
5252 * 	Description
5253 * 		Find BTF type with given name and kind in vmlinux BTF or in module's BTFs.
5254 * 	Return
5255 * 		Returns btf_id and btf_obj_fd in lower and upper 32 bits.
5256 *
5257 * long bpf_sys_close(u32 fd)
5258 * 	Description
5259 * 		Execute close syscall for given FD.
5260 * 	Return
5261 * 		A syscall result.
5262 *
5263 * long bpf_timer_init(struct bpf_timer *timer, struct bpf_map *map, u64 flags)
5264 *	Description
5265 *		Initialize the timer.
5266 *		First 4 bits of *flags* specify clockid.
5267 *		Only CLOCK_MONOTONIC, CLOCK_REALTIME, CLOCK_BOOTTIME are allowed.
5268 *		All other bits of *flags* are reserved.
5269 *		The verifier will reject the program if *timer* is not from
5270 *		the same *map*.
5271 *	Return
5272 *		0 on success.
5273 *		**-EBUSY** if *timer* is already initialized.
5274 *		**-EINVAL** if invalid *flags* are passed.
5275 *		**-EPERM** if *timer* is in a map that doesn't have any user references.
5276 *		The user space should either hold a file descriptor to a map with timers
5277 *		or pin such map in bpffs. When map is unpinned or file descriptor is
5278 *		closed all timers in the map will be cancelled and freed.
5279 *
5280 * long bpf_timer_set_callback(struct bpf_timer *timer, void *callback_fn)
5281 *	Description
5282 *		Configure the timer to call *callback_fn* static function.
5283 *	Return
5284 *		0 on success.
5285 *		**-EINVAL** if *timer* was not initialized with bpf_timer_init() earlier.
5286 *		**-EPERM** if *timer* is in a map that doesn't have any user references.
5287 *		The user space should either hold a file descriptor to a map with timers
5288 *		or pin such map in bpffs. When map is unpinned or file descriptor is
5289 *		closed all timers in the map will be cancelled and freed.
5290 *
5291 * long bpf_timer_start(struct bpf_timer *timer, u64 nsecs, u64 flags)
5292 *	Description
5293 *		Set timer expiration N nanoseconds from the current time. The
5294 *		configured callback will be invoked in soft irq context on some cpu
5295 *		and will not repeat unless another bpf_timer_start() is made.
5296 *		In such case the next invocation can migrate to a different cpu.
5297 *		Since struct bpf_timer is a field inside map element the map
5298 *		owns the timer. The bpf_timer_set_callback() will increment refcnt
5299 *		of BPF program to make sure that callback_fn code stays valid.
5300 *		When user space reference to a map reaches zero all timers
5301 *		in a map are cancelled and corresponding program's refcnts are
5302 *		decremented. This is done to make sure that Ctrl-C of a user
5303 *		process doesn't leave any timers running. If map is pinned in
5304 *		bpffs the callback_fn can re-arm itself indefinitely.
5305 *		bpf_map_update/delete_elem() helpers and user space sys_bpf commands
5306 *		cancel and free the timer in the given map element.
5307 *		The map can contain timers that invoke callback_fn-s from different
5308 *		programs. The same callback_fn can serve different timers from
5309 *		different maps if key/value layout matches across maps.
5310 *		Every bpf_timer_set_callback() can have different callback_fn.
5311 *
5312 *		*flags* can be one of:
5313 *
5314 *		**BPF_F_TIMER_ABS**
5315 *			Start the timer in absolute expire value instead of the
5316 *			default relative one.
5317 *		**BPF_F_TIMER_CPU_PIN**
5318 *			Timer will be pinned to the CPU of the caller.
5319 *
5320 *	Return
5321 *		0 on success.
5322 *		**-EINVAL** if *timer* was not initialized with bpf_timer_init() earlier
5323 *		or invalid *flags* are passed.
5324 *
5325 * long bpf_timer_cancel(struct bpf_timer *timer)
5326 *	Description
5327 *		Cancel the timer and wait for callback_fn to finish if it was running.
5328 *	Return
5329 *		0 if the timer was not active.
5330 *		1 if the timer was active.
5331 *		**-EINVAL** if *timer* was not initialized with bpf_timer_init() earlier.
5332 *		**-EDEADLK** if callback_fn tried to call bpf_timer_cancel() on its
5333 *		own timer which would have led to a deadlock otherwise.
5334 *
5335 * u64 bpf_get_func_ip(void *ctx)
5336 * 	Description
5337 * 		Get address of the traced function (for tracing and kprobe programs).
5338 *
5339 * 		When called for kprobe program attached as uprobe it returns
5340 * 		probe address for both entry and return uprobe.
5341 *
5342 * 	Return
5343 * 		Address of the traced function for kprobe.
5344 * 		0 for kprobes placed within the function (not at the entry).
5345 * 		Address of the probe for uprobe and return uprobe.
5346 *
5347 * u64 bpf_get_attach_cookie(void *ctx)
5348 * 	Description
5349 * 		Get bpf_cookie value provided (optionally) during the program
5350 * 		attachment. It might be different for each individual
5351 * 		attachment, even if BPF program itself is the same.
5352 * 		Expects BPF program context *ctx* as a first argument.
5353 *
5354 * 		Supported for the following program types:
5355 *			- kprobe/uprobe;
5356 *			- tracepoint;
5357 *			- perf_event.
5358 * 	Return
5359 *		Value specified by user at BPF link creation/attachment time
5360 *		or 0, if it was not specified.
5361 *
5362 * long bpf_task_pt_regs(struct task_struct *task)
5363 *	Description
5364 *		Get the struct pt_regs associated with **task**.
5365 *	Return
5366 *		A pointer to struct pt_regs.
5367 *
5368 * long bpf_get_branch_snapshot(void *entries, u32 size, u64 flags)
5369 *	Description
5370 *		Get branch trace from hardware engines like Intel LBR. The
5371 *		hardware engine is stopped shortly after the helper is
5372 *		called. Therefore, the user need to filter branch entries
5373 *		based on the actual use case. To capture branch trace
5374 *		before the trigger point of the BPF program, the helper
5375 *		should be called at the beginning of the BPF program.
5376 *
5377 *		The data is stored as struct perf_branch_entry into output
5378 *		buffer *entries*. *size* is the size of *entries* in bytes.
5379 *		*flags* is reserved for now and must be zero.
5380 *
5381 *	Return
5382 *		On success, number of bytes written to *buf*. On error, a
5383 *		negative value.
5384 *
5385 *		**-EINVAL** if *flags* is not zero.
5386 *
5387 *		**-ENOENT** if architecture does not support branch records.
5388 *
5389 * long bpf_trace_vprintk(const char *fmt, u32 fmt_size, const void *data, u32 data_len)
5390 *	Description
5391 *		Behaves like **bpf_trace_printk**\ () helper, but takes an array of u64
5392 *		to format and can handle more format args as a result.
5393 *
5394 *		Arguments are to be used as in **bpf_seq_printf**\ () helper.
5395 *	Return
5396 *		The number of bytes written to the buffer, or a negative error
5397 *		in case of failure.
5398 *
5399 * struct unix_sock *bpf_skc_to_unix_sock(void *sk)
5400 * 	Description
5401 *		Dynamically cast a *sk* pointer to a *unix_sock* pointer.
5402 *	Return
5403 *		*sk* if casting is valid, or **NULL** otherwise.
5404 *
5405 * long bpf_kallsyms_lookup_name(const char *name, int name_sz, int flags, u64 *res)
5406 *	Description
5407 *		Get the address of a kernel symbol, returned in *res*. *res* is
5408 *		set to 0 if the symbol is not found.
5409 *	Return
5410 *		On success, zero. On error, a negative value.
5411 *
5412 *		**-EINVAL** if *flags* is not zero.
5413 *
5414 *		**-EINVAL** if string *name* is not the same size as *name_sz*.
5415 *
5416 *		**-ENOENT** if symbol is not found.
5417 *
5418 *		**-EPERM** if caller does not have permission to obtain kernel address.
5419 *
5420 * long bpf_find_vma(struct task_struct *task, u64 addr, void *callback_fn, void *callback_ctx, u64 flags)
5421 *	Description
5422 *		Find vma of *task* that contains *addr*, call *callback_fn*
5423 *		function with *task*, *vma*, and *callback_ctx*.
5424 *		The *callback_fn* should be a static function and
5425 *		the *callback_ctx* should be a pointer to the stack.
5426 *		The *flags* is used to control certain aspects of the helper.
5427 *		Currently, the *flags* must be 0.
5428 *
5429 *		The expected callback signature is
5430 *
5431 *		long (\*callback_fn)(struct task_struct \*task, struct vm_area_struct \*vma, void \*callback_ctx);
5432 *
5433 *	Return
5434 *		0 on success.
5435 *		**-ENOENT** if *task->mm* is NULL, or no vma contains *addr*.
5436 *		**-EBUSY** if failed to try lock mmap_lock.
5437 *		**-EINVAL** for invalid **flags**.
5438 *
5439 * long bpf_loop(u32 nr_loops, void *callback_fn, void *callback_ctx, u64 flags)
5440 *	Description
5441 *		For **nr_loops**, call **callback_fn** function
5442 *		with **callback_ctx** as the context parameter.
5443 *		The **callback_fn** should be a static function and
5444 *		the **callback_ctx** should be a pointer to the stack.
5445 *		The **flags** is used to control certain aspects of the helper.
5446 *		Currently, the **flags** must be 0. Currently, nr_loops is
5447 *		limited to 1 << 23 (~8 million) loops.
5448 *
5449 *		long (\*callback_fn)(u64 index, void \*ctx);
5450 *
5451 *		where **index** is the current index in the loop. The index
5452 *		is zero-indexed.
5453 *
5454 *		If **callback_fn** returns 0, the helper will continue to the next
5455 *		loop. If return value is 1, the helper will skip the rest of
5456 *		the loops and return. Other return values are not used now,
5457 *		and will be rejected by the verifier.
5458 *
5459 *	Return
5460 *		The number of loops performed, **-EINVAL** for invalid **flags**,
5461 *		**-E2BIG** if **nr_loops** exceeds the maximum number of loops.
5462 *
5463 * long bpf_strncmp(const char *s1, u32 s1_sz, const char *s2)
5464 *	Description
5465 *		Do strncmp() between **s1** and **s2**. **s1** doesn't need
5466 *		to be null-terminated and **s1_sz** is the maximum storage
5467 *		size of **s1**. **s2** must be a read-only string.
5468 *	Return
5469 *		An integer less than, equal to, or greater than zero
5470 *		if the first **s1_sz** bytes of **s1** is found to be
5471 *		less than, to match, or be greater than **s2**.
5472 *
5473 * long bpf_get_func_arg(void *ctx, u32 n, u64 *value)
5474 *	Description
5475 *		Get **n**-th argument register (zero based) of the traced function (for tracing programs)
5476 *		returned in **value**.
5477 *
5478 *	Return
5479 *		0 on success.
5480 *		**-EINVAL** if n >= argument register count of traced function.
5481 *
5482 * long bpf_get_func_ret(void *ctx, u64 *value)
5483 *	Description
5484 *		Get return value of the traced function (for tracing programs)
5485 *		in **value**.
5486 *
5487 *	Return
5488 *		0 on success.
5489 *		**-EOPNOTSUPP** for tracing programs other than BPF_TRACE_FEXIT or BPF_MODIFY_RETURN.
5490 *
5491 * long bpf_get_func_arg_cnt(void *ctx)
5492 *	Description
5493 *		Get number of registers of the traced function (for tracing programs) where
5494 *		function arguments are stored in these registers.
5495 *
5496 *	Return
5497 *		The number of argument registers of the traced function.
5498 *
5499 * int bpf_get_retval(void)
5500 *	Description
5501 *		Get the BPF program's return value that will be returned to the upper layers.
5502 *
5503 *		This helper is currently supported by cgroup programs and only by the hooks
5504 *		where BPF program's return value is returned to the userspace via errno.
5505 *	Return
5506 *		The BPF program's return value.
5507 *
5508 * int bpf_set_retval(int retval)
5509 *	Description
5510 *		Set the BPF program's return value that will be returned to the upper layers.
5511 *
5512 *		This helper is currently supported by cgroup programs and only by the hooks
5513 *		where BPF program's return value is returned to the userspace via errno.
5514 *
5515 *		Note that there is the following corner case where the program exports an error
5516 *		via bpf_set_retval but signals success via 'return 1':
5517 *
5518 *			bpf_set_retval(-EPERM);
5519 *			return 1;
5520 *
5521 *		In this case, the BPF program's return value will use helper's -EPERM. This
5522 *		still holds true for cgroup/bind{4,6} which supports extra 'return 3' success case.
5523 *
5524 *	Return
5525 *		0 on success, or a negative error in case of failure.
5526 *
5527 * u64 bpf_xdp_get_buff_len(struct xdp_buff *xdp_md)
5528 *	Description
5529 *		Get the total size of a given xdp buff (linear and paged area)
5530 *	Return
5531 *		The total size of a given xdp buffer.
5532 *
5533 * long bpf_xdp_load_bytes(struct xdp_buff *xdp_md, u32 offset, void *buf, u32 len)
5534 *	Description
5535 *		This helper is provided as an easy way to load data from a
5536 *		xdp buffer. It can be used to load *len* bytes from *offset* from
5537 *		the frame associated to *xdp_md*, into the buffer pointed by
5538 *		*buf*.
5539 *	Return
5540 *		0 on success, or a negative error in case of failure.
5541 *
5542 * long bpf_xdp_store_bytes(struct xdp_buff *xdp_md, u32 offset, void *buf, u32 len)
5543 *	Description
5544 *		Store *len* bytes from buffer *buf* into the frame
5545 *		associated to *xdp_md*, at *offset*.
5546 *	Return
5547 *		0 on success, or a negative error in case of failure.
5548 *
5549 * long bpf_copy_from_user_task(void *dst, u32 size, const void *user_ptr, struct task_struct *tsk, u64 flags)
5550 *	Description
5551 *		Read *size* bytes from user space address *user_ptr* in *tsk*'s
5552 *		address space, and stores the data in *dst*. *flags* is not
5553 *		used yet and is provided for future extensibility. This helper
5554 *		can only be used by sleepable programs.
5555 *	Return
5556 *		0 on success, or a negative error in case of failure. On error
5557 *		*dst* buffer is zeroed out.
5558 *
5559 * long bpf_skb_set_tstamp(struct sk_buff *skb, u64 tstamp, u32 tstamp_type)
5560 *	Description
5561 *		Change the __sk_buff->tstamp_type to *tstamp_type*
5562 *		and set *tstamp* to the __sk_buff->tstamp together.
5563 *
5564 *		If there is no need to change the __sk_buff->tstamp_type,
5565 *		the tstamp value can be directly written to __sk_buff->tstamp
5566 *		instead.
5567 *
5568 *		BPF_SKB_TSTAMP_DELIVERY_MONO is the only tstamp that
5569 *		will be kept during bpf_redirect_*().  A non zero
5570 *		*tstamp* must be used with the BPF_SKB_TSTAMP_DELIVERY_MONO
5571 *		*tstamp_type*.
5572 *
5573 *		A BPF_SKB_TSTAMP_UNSPEC *tstamp_type* can only be used
5574 *		with a zero *tstamp*.
5575 *
5576 *		Only IPv4 and IPv6 skb->protocol are supported.
5577 *
5578 *		This function is most useful when it needs to set a
5579 *		mono delivery time to __sk_buff->tstamp and then
5580 *		bpf_redirect_*() to the egress of an iface.  For example,
5581 *		changing the (rcv) timestamp in __sk_buff->tstamp at
5582 *		ingress to a mono delivery time and then bpf_redirect_*()
5583 *		to sch_fq@phy-dev.
5584 *	Return
5585 *		0 on success.
5586 *		**-EINVAL** for invalid input
5587 *		**-EOPNOTSUPP** for unsupported protocol
5588 *
5589 * long bpf_ima_file_hash(struct file *file, void *dst, u32 size)
5590 *	Description
5591 *		Returns a calculated IMA hash of the *file*.
5592 *		If the hash is larger than *size*, then only *size*
5593 *		bytes will be copied to *dst*
5594 *	Return
5595 *		The **hash_algo** is returned on success,
5596 *		**-EOPNOTSUPP** if the hash calculation failed or **-EINVAL** if
5597 *		invalid arguments are passed.
5598 *
5599 * void *bpf_kptr_xchg(void *dst, void *ptr)
5600 *	Description
5601 *		Exchange kptr at pointer *dst* with *ptr*, and return the old value.
5602 *		*dst* can be map value or local kptr. *ptr* can be NULL, otherwise
5603 *		it must be a referenced pointer which will be released when this helper
5604 *		is called.
5605 *	Return
5606 *		The old value of kptr (which can be NULL). The returned pointer
5607 *		if not NULL, is a reference which must be released using its
5608 *		corresponding release function, or moved into a BPF map before
5609 *		program exit.
5610 *
5611 * void *bpf_map_lookup_percpu_elem(struct bpf_map *map, const void *key, u32 cpu)
5612 * 	Description
5613 * 		Perform a lookup in *percpu map* for an entry associated to
5614 * 		*key* on *cpu*.
5615 * 	Return
5616 * 		Map value associated to *key* on *cpu*, or **NULL** if no entry
5617 * 		was found or *cpu* is invalid.
5618 *
5619 * struct mptcp_sock *bpf_skc_to_mptcp_sock(void *sk)
5620 *	Description
5621 *		Dynamically cast a *sk* pointer to a *mptcp_sock* pointer.
5622 *	Return
5623 *		*sk* if casting is valid, or **NULL** otherwise.
5624 *
5625 * long bpf_dynptr_from_mem(void *data, u64 size, u64 flags, struct bpf_dynptr *ptr)
5626 *	Description
5627 *		Get a dynptr to local memory *data*.
5628 *
5629 *		*data* must be a ptr to a map value.
5630 *		The maximum *size* supported is DYNPTR_MAX_SIZE.
5631 *		*flags* is currently unused.
5632 *	Return
5633 *		0 on success, -E2BIG if the size exceeds DYNPTR_MAX_SIZE,
5634 *		-EINVAL if flags is not 0.
5635 *
5636 * long bpf_ringbuf_reserve_dynptr(void *ringbuf, u32 size, u64 flags, struct bpf_dynptr *ptr)
5637 *	Description
5638 *		Reserve *size* bytes of payload in a ring buffer *ringbuf*
5639 *		through the dynptr interface. *flags* must be 0.
5640 *
5641 *		Please note that a corresponding bpf_ringbuf_submit_dynptr or
5642 *		bpf_ringbuf_discard_dynptr must be called on *ptr*, even if the
5643 *		reservation fails. This is enforced by the verifier.
5644 *	Return
5645 *		0 on success, or a negative error in case of failure.
5646 *
5647 * void bpf_ringbuf_submit_dynptr(struct bpf_dynptr *ptr, u64 flags)
5648 *	Description
5649 *		Submit reserved ring buffer sample, pointed to by *data*,
5650 *		through the dynptr interface. This is a no-op if the dynptr is
5651 *		invalid/null.
5652 *
5653 *		For more information on *flags*, please see
5654 *		'bpf_ringbuf_submit'.
5655 *	Return
5656 *		Nothing. Always succeeds.
5657 *
5658 * void bpf_ringbuf_discard_dynptr(struct bpf_dynptr *ptr, u64 flags)
5659 *	Description
5660 *		Discard reserved ring buffer sample through the dynptr
5661 *		interface. This is a no-op if the dynptr is invalid/null.
5662 *
5663 *		For more information on *flags*, please see
5664 *		'bpf_ringbuf_discard'.
5665 *	Return
5666 *		Nothing. Always succeeds.
5667 *
5668 * long bpf_dynptr_read(void *dst, u64 len, const struct bpf_dynptr *src, u64 offset, u64 flags)
5669 *	Description
5670 *		Read *len* bytes from *src* into *dst*, starting from *offset*
5671 *		into *src*.
5672 *		*flags* is currently unused.
5673 *	Return
5674 *		0 on success, -E2BIG if *offset* + *len* exceeds the length
5675 *		of *src*'s data, -EINVAL if *src* is an invalid dynptr or if
5676 *		*flags* is not 0.
5677 *
5678 * long bpf_dynptr_write(const struct bpf_dynptr *dst, u64 offset, void *src, u64 len, u64 flags)
5679 *	Description
5680 *		Write *len* bytes from *src* into *dst*, starting from *offset*
5681 *		into *dst*.
5682 *
5683 *		*flags* must be 0 except for skb-type dynptrs.
5684 *
5685 *		For skb-type dynptrs:
5686 *		    *  All data slices of the dynptr are automatically
5687 *		       invalidated after **bpf_dynptr_write**\ (). This is
5688 *		       because writing may pull the skb and change the
5689 *		       underlying packet buffer.
5690 *
5691 *		    *  For *flags*, please see the flags accepted by
5692 *		       **bpf_skb_store_bytes**\ ().
5693 *	Return
5694 *		0 on success, -E2BIG if *offset* + *len* exceeds the length
5695 *		of *dst*'s data, -EINVAL if *dst* is an invalid dynptr or if *dst*
5696 *		is a read-only dynptr or if *flags* is not correct. For skb-type dynptrs,
5697 *		other errors correspond to errors returned by **bpf_skb_store_bytes**\ ().
5698 *
5699 * void *bpf_dynptr_data(const struct bpf_dynptr *ptr, u64 offset, u64 len)
5700 *	Description
5701 *		Get a pointer to the underlying dynptr data.
5702 *
5703 *		*len* must be a statically known value. The returned data slice
5704 *		is invalidated whenever the dynptr is invalidated.
5705 *
5706 *		skb and xdp type dynptrs may not use bpf_dynptr_data. They should
5707 *		instead use bpf_dynptr_slice and bpf_dynptr_slice_rdwr.
5708 *	Return
5709 *		Pointer to the underlying dynptr data, NULL if the dynptr is
5710 *		read-only, if the dynptr is invalid, or if the offset and length
5711 *		is out of bounds.
5712 *
5713 * s64 bpf_tcp_raw_gen_syncookie_ipv4(struct iphdr *iph, struct tcphdr *th, u32 th_len)
5714 *	Description
5715 *		Try to issue a SYN cookie for the packet with corresponding
5716 *		IPv4/TCP headers, *iph* and *th*, without depending on a
5717 *		listening socket.
5718 *
5719 *		*iph* points to the IPv4 header.
5720 *
5721 *		*th* points to the start of the TCP header, while *th_len*
5722 *		contains the length of the TCP header (at least
5723 *		**sizeof**\ (**struct tcphdr**)).
5724 *	Return
5725 *		On success, lower 32 bits hold the generated SYN cookie in
5726 *		followed by 16 bits which hold the MSS value for that cookie,
5727 *		and the top 16 bits are unused.
5728 *
5729 *		On failure, the returned value is one of the following:
5730 *
5731 *		**-EINVAL** if *th_len* is invalid.
5732 *
5733 * s64 bpf_tcp_raw_gen_syncookie_ipv6(struct ipv6hdr *iph, struct tcphdr *th, u32 th_len)
5734 *	Description
5735 *		Try to issue a SYN cookie for the packet with corresponding
5736 *		IPv6/TCP headers, *iph* and *th*, without depending on a
5737 *		listening socket.
5738 *
5739 *		*iph* points to the IPv6 header.
5740 *
5741 *		*th* points to the start of the TCP header, while *th_len*
5742 *		contains the length of the TCP header (at least
5743 *		**sizeof**\ (**struct tcphdr**)).
5744 *	Return
5745 *		On success, lower 32 bits hold the generated SYN cookie in
5746 *		followed by 16 bits which hold the MSS value for that cookie,
5747 *		and the top 16 bits are unused.
5748 *
5749 *		On failure, the returned value is one of the following:
5750 *
5751 *		**-EINVAL** if *th_len* is invalid.
5752 *
5753 *		**-EPROTONOSUPPORT** if CONFIG_IPV6 is not builtin.
5754 *
5755 * long bpf_tcp_raw_check_syncookie_ipv4(struct iphdr *iph, struct tcphdr *th)
5756 *	Description
5757 *		Check whether *iph* and *th* contain a valid SYN cookie ACK
5758 *		without depending on a listening socket.
5759 *
5760 *		*iph* points to the IPv4 header.
5761 *
5762 *		*th* points to the TCP header.
5763 *	Return
5764 *		0 if *iph* and *th* are a valid SYN cookie ACK.
5765 *
5766 *		On failure, the returned value is one of the following:
5767 *
5768 *		**-EACCES** if the SYN cookie is not valid.
5769 *
5770 * long bpf_tcp_raw_check_syncookie_ipv6(struct ipv6hdr *iph, struct tcphdr *th)
5771 *	Description
5772 *		Check whether *iph* and *th* contain a valid SYN cookie ACK
5773 *		without depending on a listening socket.
5774 *
5775 *		*iph* points to the IPv6 header.
5776 *
5777 *		*th* points to the TCP header.
5778 *	Return
5779 *		0 if *iph* and *th* are a valid SYN cookie ACK.
5780 *
5781 *		On failure, the returned value is one of the following:
5782 *
5783 *		**-EACCES** if the SYN cookie is not valid.
5784 *
5785 *		**-EPROTONOSUPPORT** if CONFIG_IPV6 is not builtin.
5786 *
5787 * u64 bpf_ktime_get_tai_ns(void)
5788 *	Description
5789 *		A nonsettable system-wide clock derived from wall-clock time but
5790 *		ignoring leap seconds.  This clock does not experience
5791 *		discontinuities and backwards jumps caused by NTP inserting leap
5792 *		seconds as CLOCK_REALTIME does.
5793 *
5794 *		See: **clock_gettime**\ (**CLOCK_TAI**)
5795 *	Return
5796 *		Current *ktime*.
5797 *
5798 * long bpf_user_ringbuf_drain(struct bpf_map *map, void *callback_fn, void *ctx, u64 flags)
5799 *	Description
5800 *		Drain samples from the specified user ring buffer, and invoke
5801 *		the provided callback for each such sample:
5802 *
5803 *		long (\*callback_fn)(const struct bpf_dynptr \*dynptr, void \*ctx);
5804 *
5805 *		If **callback_fn** returns 0, the helper will continue to try
5806 *		and drain the next sample, up to a maximum of
5807 *		BPF_MAX_USER_RINGBUF_SAMPLES samples. If the return value is 1,
5808 *		the helper will skip the rest of the samples and return. Other
5809 *		return values are not used now, and will be rejected by the
5810 *		verifier.
5811 *	Return
5812 *		The number of drained samples if no error was encountered while
5813 *		draining samples, or 0 if no samples were present in the ring
5814 *		buffer. If a user-space producer was epoll-waiting on this map,
5815 *		and at least one sample was drained, they will receive an event
5816 *		notification notifying them of available space in the ring
5817 *		buffer. If the BPF_RB_NO_WAKEUP flag is passed to this
5818 *		function, no wakeup notification will be sent. If the
5819 *		BPF_RB_FORCE_WAKEUP flag is passed, a wakeup notification will
5820 *		be sent even if no sample was drained.
5821 *
5822 *		On failure, the returned value is one of the following:
5823 *
5824 *		**-EBUSY** if the ring buffer is contended, and another calling
5825 *		context was concurrently draining the ring buffer.
5826 *
5827 *		**-EINVAL** if user-space is not properly tracking the ring
5828 *		buffer due to the producer position not being aligned to 8
5829 *		bytes, a sample not being aligned to 8 bytes, or the producer
5830 *		position not matching the advertised length of a sample.
5831 *
5832 *		**-E2BIG** if user-space has tried to publish a sample which is
5833 *		larger than the size of the ring buffer, or which cannot fit
5834 *		within a struct bpf_dynptr.
5835 *
5836 * void *bpf_cgrp_storage_get(struct bpf_map *map, struct cgroup *cgroup, void *value, u64 flags)
5837 *	Description
5838 *		Get a bpf_local_storage from the *cgroup*.
5839 *
5840 *		Logically, it could be thought of as getting the value from
5841 *		a *map* with *cgroup* as the **key**.  From this
5842 *		perspective,  the usage is not much different from
5843 *		**bpf_map_lookup_elem**\ (*map*, **&**\ *cgroup*) except this
5844 *		helper enforces the key must be a cgroup struct and the map must also
5845 *		be a **BPF_MAP_TYPE_CGRP_STORAGE**.
5846 *
5847 *		In reality, the local-storage value is embedded directly inside of the
5848 *		*cgroup* object itself, rather than being located in the
5849 *		**BPF_MAP_TYPE_CGRP_STORAGE** map. When the local-storage value is
5850 *		queried for some *map* on a *cgroup* object, the kernel will perform an
5851 *		O(n) iteration over all of the live local-storage values for that
5852 *		*cgroup* object until the local-storage value for the *map* is found.
5853 *
5854 *		An optional *flags* (**BPF_LOCAL_STORAGE_GET_F_CREATE**) can be
5855 *		used such that a new bpf_local_storage will be
5856 *		created if one does not exist.  *value* can be used
5857 *		together with **BPF_LOCAL_STORAGE_GET_F_CREATE** to specify
5858 *		the initial value of a bpf_local_storage.  If *value* is
5859 *		**NULL**, the new bpf_local_storage will be zero initialized.
5860 *	Return
5861 *		A bpf_local_storage pointer is returned on success.
5862 *
5863 *		**NULL** if not found or there was an error in adding
5864 *		a new bpf_local_storage.
5865 *
5866 * long bpf_cgrp_storage_delete(struct bpf_map *map, struct cgroup *cgroup)
5867 *	Description
5868 *		Delete a bpf_local_storage from a *cgroup*.
5869 *	Return
5870 *		0 on success.
5871 *
5872 *		**-ENOENT** if the bpf_local_storage cannot be found.
5873 */
5874#define ___BPF_FUNC_MAPPER(FN, ctx...)			\
5875	FN(unspec, 0, ##ctx)				\
5876	FN(map_lookup_elem, 1, ##ctx)			\
5877	FN(map_update_elem, 2, ##ctx)			\
5878	FN(map_delete_elem, 3, ##ctx)			\
5879	FN(probe_read, 4, ##ctx)			\
5880	FN(ktime_get_ns, 5, ##ctx)			\
5881	FN(trace_printk, 6, ##ctx)			\
5882	FN(get_prandom_u32, 7, ##ctx)			\
5883	FN(get_smp_processor_id, 8, ##ctx)		\
5884	FN(skb_store_bytes, 9, ##ctx)			\
5885	FN(l3_csum_replace, 10, ##ctx)			\
5886	FN(l4_csum_replace, 11, ##ctx)			\
5887	FN(tail_call, 12, ##ctx)			\
5888	FN(clone_redirect, 13, ##ctx)			\
5889	FN(get_current_pid_tgid, 14, ##ctx)		\
5890	FN(get_current_uid_gid, 15, ##ctx)		\
5891	FN(get_current_comm, 16, ##ctx)			\
5892	FN(get_cgroup_classid, 17, ##ctx)		\
5893	FN(skb_vlan_push, 18, ##ctx)			\
5894	FN(skb_vlan_pop, 19, ##ctx)			\
5895	FN(skb_get_tunnel_key, 20, ##ctx)		\
5896	FN(skb_set_tunnel_key, 21, ##ctx)		\
5897	FN(perf_event_read, 22, ##ctx)			\
5898	FN(redirect, 23, ##ctx)				\
5899	FN(get_route_realm, 24, ##ctx)			\
5900	FN(perf_event_output, 25, ##ctx)		\
5901	FN(skb_load_bytes, 26, ##ctx)			\
5902	FN(get_stackid, 27, ##ctx)			\
5903	FN(csum_diff, 28, ##ctx)			\
5904	FN(skb_get_tunnel_opt, 29, ##ctx)		\
5905	FN(skb_set_tunnel_opt, 30, ##ctx)		\
5906	FN(skb_change_proto, 31, ##ctx)			\
5907	FN(skb_change_type, 32, ##ctx)			\
5908	FN(skb_under_cgroup, 33, ##ctx)			\
5909	FN(get_hash_recalc, 34, ##ctx)			\
5910	FN(get_current_task, 35, ##ctx)			\
5911	FN(probe_write_user, 36, ##ctx)			\
5912	FN(current_task_under_cgroup, 37, ##ctx)	\
5913	FN(skb_change_tail, 38, ##ctx)			\
5914	FN(skb_pull_data, 39, ##ctx)			\
5915	FN(csum_update, 40, ##ctx)			\
5916	FN(set_hash_invalid, 41, ##ctx)			\
5917	FN(get_numa_node_id, 42, ##ctx)			\
5918	FN(skb_change_head, 43, ##ctx)			\
5919	FN(xdp_adjust_head, 44, ##ctx)			\
5920	FN(probe_read_str, 45, ##ctx)			\
5921	FN(get_socket_cookie, 46, ##ctx)		\
5922	FN(get_socket_uid, 47, ##ctx)			\
5923	FN(set_hash, 48, ##ctx)				\
5924	FN(setsockopt, 49, ##ctx)			\
5925	FN(skb_adjust_room, 50, ##ctx)			\
5926	FN(redirect_map, 51, ##ctx)			\
5927	FN(sk_redirect_map, 52, ##ctx)			\
5928	FN(sock_map_update, 53, ##ctx)			\
5929	FN(xdp_adjust_meta, 54, ##ctx)			\
5930	FN(perf_event_read_value, 55, ##ctx)		\
5931	FN(perf_prog_read_value, 56, ##ctx)		\
5932	FN(getsockopt, 57, ##ctx)			\
5933	FN(override_return, 58, ##ctx)			\
5934	FN(sock_ops_cb_flags_set, 59, ##ctx)		\
5935	FN(msg_redirect_map, 60, ##ctx)			\
5936	FN(msg_apply_bytes, 61, ##ctx)			\
5937	FN(msg_cork_bytes, 62, ##ctx)			\
5938	FN(msg_pull_data, 63, ##ctx)			\
5939	FN(bind, 64, ##ctx)				\
5940	FN(xdp_adjust_tail, 65, ##ctx)			\
5941	FN(skb_get_xfrm_state, 66, ##ctx)		\
5942	FN(get_stack, 67, ##ctx)			\
5943	FN(skb_load_bytes_relative, 68, ##ctx)		\
5944	FN(fib_lookup, 69, ##ctx)			\
5945	FN(sock_hash_update, 70, ##ctx)			\
5946	FN(msg_redirect_hash, 71, ##ctx)		\
5947	FN(sk_redirect_hash, 72, ##ctx)			\
5948	FN(lwt_push_encap, 73, ##ctx)			\
5949	FN(lwt_seg6_store_bytes, 74, ##ctx)		\
5950	FN(lwt_seg6_adjust_srh, 75, ##ctx)		\
5951	FN(lwt_seg6_action, 76, ##ctx)			\
5952	FN(rc_repeat, 77, ##ctx)			\
5953	FN(rc_keydown, 78, ##ctx)			\
5954	FN(skb_cgroup_id, 79, ##ctx)			\
5955	FN(get_current_cgroup_id, 80, ##ctx)		\
5956	FN(get_local_storage, 81, ##ctx)		\
5957	FN(sk_select_reuseport, 82, ##ctx)		\
5958	FN(skb_ancestor_cgroup_id, 83, ##ctx)		\
5959	FN(sk_lookup_tcp, 84, ##ctx)			\
5960	FN(sk_lookup_udp, 85, ##ctx)			\
5961	FN(sk_release, 86, ##ctx)			\
5962	FN(map_push_elem, 87, ##ctx)			\
5963	FN(map_pop_elem, 88, ##ctx)			\
5964	FN(map_peek_elem, 89, ##ctx)			\
5965	FN(msg_push_data, 90, ##ctx)			\
5966	FN(msg_pop_data, 91, ##ctx)			\
5967	FN(rc_pointer_rel, 92, ##ctx)			\
5968	FN(spin_lock, 93, ##ctx)			\
5969	FN(spin_unlock, 94, ##ctx)			\
5970	FN(sk_fullsock, 95, ##ctx)			\
5971	FN(tcp_sock, 96, ##ctx)				\
5972	FN(skb_ecn_set_ce, 97, ##ctx)			\
5973	FN(get_listener_sock, 98, ##ctx)		\
5974	FN(skc_lookup_tcp, 99, ##ctx)			\
5975	FN(tcp_check_syncookie, 100, ##ctx)		\
5976	FN(sysctl_get_name, 101, ##ctx)			\
5977	FN(sysctl_get_current_value, 102, ##ctx)	\
5978	FN(sysctl_get_new_value, 103, ##ctx)		\
5979	FN(sysctl_set_new_value, 104, ##ctx)		\
5980	FN(strtol, 105, ##ctx)				\
5981	FN(strtoul, 106, ##ctx)				\
5982	FN(sk_storage_get, 107, ##ctx)			\
5983	FN(sk_storage_delete, 108, ##ctx)		\
5984	FN(send_signal, 109, ##ctx)			\
5985	FN(tcp_gen_syncookie, 110, ##ctx)		\
5986	FN(skb_output, 111, ##ctx)			\
5987	FN(probe_read_user, 112, ##ctx)			\
5988	FN(probe_read_kernel, 113, ##ctx)		\
5989	FN(probe_read_user_str, 114, ##ctx)		\
5990	FN(probe_read_kernel_str, 115, ##ctx)		\
5991	FN(tcp_send_ack, 116, ##ctx)			\
5992	FN(send_signal_thread, 117, ##ctx)		\
5993	FN(jiffies64, 118, ##ctx)			\
5994	FN(read_branch_records, 119, ##ctx)		\
5995	FN(get_ns_current_pid_tgid, 120, ##ctx)		\
5996	FN(xdp_output, 121, ##ctx)			\
5997	FN(get_netns_cookie, 122, ##ctx)		\
5998	FN(get_current_ancestor_cgroup_id, 123, ##ctx)	\
5999	FN(sk_assign, 124, ##ctx)			\
6000	FN(ktime_get_boot_ns, 125, ##ctx)		\
6001	FN(seq_printf, 126, ##ctx)			\
6002	FN(seq_write, 127, ##ctx)			\
6003	FN(sk_cgroup_id, 128, ##ctx)			\
6004	FN(sk_ancestor_cgroup_id, 129, ##ctx)		\
6005	FN(ringbuf_output, 130, ##ctx)			\
6006	FN(ringbuf_reserve, 131, ##ctx)			\
6007	FN(ringbuf_submit, 132, ##ctx)			\
6008	FN(ringbuf_discard, 133, ##ctx)			\
6009	FN(ringbuf_query, 134, ##ctx)			\
6010	FN(csum_level, 135, ##ctx)			\
6011	FN(skc_to_tcp6_sock, 136, ##ctx)		\
6012	FN(skc_to_tcp_sock, 137, ##ctx)			\
6013	FN(skc_to_tcp_timewait_sock, 138, ##ctx)	\
6014	FN(skc_to_tcp_request_sock, 139, ##ctx)		\
6015	FN(skc_to_udp6_sock, 140, ##ctx)		\
6016	FN(get_task_stack, 141, ##ctx)			\
6017	FN(load_hdr_opt, 142, ##ctx)			\
6018	FN(store_hdr_opt, 143, ##ctx)			\
6019	FN(reserve_hdr_opt, 144, ##ctx)			\
6020	FN(inode_storage_get, 145, ##ctx)		\
6021	FN(inode_storage_delete, 146, ##ctx)		\
6022	FN(d_path, 147, ##ctx)				\
6023	FN(copy_from_user, 148, ##ctx)			\
6024	FN(snprintf_btf, 149, ##ctx)			\
6025	FN(seq_printf_btf, 150, ##ctx)			\
6026	FN(skb_cgroup_classid, 151, ##ctx)		\
6027	FN(redirect_neigh, 152, ##ctx)			\
6028	FN(per_cpu_ptr, 153, ##ctx)			\
6029	FN(this_cpu_ptr, 154, ##ctx)			\
6030	FN(redirect_peer, 155, ##ctx)			\
6031	FN(task_storage_get, 156, ##ctx)		\
6032	FN(task_storage_delete, 157, ##ctx)		\
6033	FN(get_current_task_btf, 158, ##ctx)		\
6034	FN(bprm_opts_set, 159, ##ctx)			\
6035	FN(ktime_get_coarse_ns, 160, ##ctx)		\
6036	FN(ima_inode_hash, 161, ##ctx)			\
6037	FN(sock_from_file, 162, ##ctx)			\
6038	FN(check_mtu, 163, ##ctx)			\
6039	FN(for_each_map_elem, 164, ##ctx)		\
6040	FN(snprintf, 165, ##ctx)			\
6041	FN(sys_bpf, 166, ##ctx)				\
6042	FN(btf_find_by_name_kind, 167, ##ctx)		\
6043	FN(sys_close, 168, ##ctx)			\
6044	FN(timer_init, 169, ##ctx)			\
6045	FN(timer_set_callback, 170, ##ctx)		\
6046	FN(timer_start, 171, ##ctx)			\
6047	FN(timer_cancel, 172, ##ctx)			\
6048	FN(get_func_ip, 173, ##ctx)			\
6049	FN(get_attach_cookie, 174, ##ctx)		\
6050	FN(task_pt_regs, 175, ##ctx)			\
6051	FN(get_branch_snapshot, 176, ##ctx)		\
6052	FN(trace_vprintk, 177, ##ctx)			\
6053	FN(skc_to_unix_sock, 178, ##ctx)		\
6054	FN(kallsyms_lookup_name, 179, ##ctx)		\
6055	FN(find_vma, 180, ##ctx)			\
6056	FN(loop, 181, ##ctx)				\
6057	FN(strncmp, 182, ##ctx)				\
6058	FN(get_func_arg, 183, ##ctx)			\
6059	FN(get_func_ret, 184, ##ctx)			\
6060	FN(get_func_arg_cnt, 185, ##ctx)		\
6061	FN(get_retval, 186, ##ctx)			\
6062	FN(set_retval, 187, ##ctx)			\
6063	FN(xdp_get_buff_len, 188, ##ctx)		\
6064	FN(xdp_load_bytes, 189, ##ctx)			\
6065	FN(xdp_store_bytes, 190, ##ctx)			\
6066	FN(copy_from_user_task, 191, ##ctx)		\
6067	FN(skb_set_tstamp, 192, ##ctx)			\
6068	FN(ima_file_hash, 193, ##ctx)			\
6069	FN(kptr_xchg, 194, ##ctx)			\
6070	FN(map_lookup_percpu_elem, 195, ##ctx)		\
6071	FN(skc_to_mptcp_sock, 196, ##ctx)		\
6072	FN(dynptr_from_mem, 197, ##ctx)			\
6073	FN(ringbuf_reserve_dynptr, 198, ##ctx)		\
6074	FN(ringbuf_submit_dynptr, 199, ##ctx)		\
6075	FN(ringbuf_discard_dynptr, 200, ##ctx)		\
6076	FN(dynptr_read, 201, ##ctx)			\
6077	FN(dynptr_write, 202, ##ctx)			\
6078	FN(dynptr_data, 203, ##ctx)			\
6079	FN(tcp_raw_gen_syncookie_ipv4, 204, ##ctx)	\
6080	FN(tcp_raw_gen_syncookie_ipv6, 205, ##ctx)	\
6081	FN(tcp_raw_check_syncookie_ipv4, 206, ##ctx)	\
6082	FN(tcp_raw_check_syncookie_ipv6, 207, ##ctx)	\
6083	FN(ktime_get_tai_ns, 208, ##ctx)		\
6084	FN(user_ringbuf_drain, 209, ##ctx)		\
6085	FN(cgrp_storage_get, 210, ##ctx)		\
6086	FN(cgrp_storage_delete, 211, ##ctx)		\
6087	/* This helper list is effectively frozen. If you are trying to	\
6088	 * add a new helper, you should add a kfunc instead which has	\
6089	 * less stability guarantees. See Documentation/bpf/kfuncs.rst	\
6090	 */
6091
6092/* backwards-compatibility macros for users of __BPF_FUNC_MAPPER that don't
6093 * know or care about integer value that is now passed as second argument
6094 */
6095#define __BPF_FUNC_MAPPER_APPLY(name, value, FN) FN(name),
6096#define __BPF_FUNC_MAPPER(FN) ___BPF_FUNC_MAPPER(__BPF_FUNC_MAPPER_APPLY, FN)
6097
6098/* integer value in 'imm' field of BPF_CALL instruction selects which helper
6099 * function eBPF program intends to call
6100 */
6101#define __BPF_ENUM_FN(x, y) BPF_FUNC_ ## x = y,
6102enum bpf_func_id {
6103	___BPF_FUNC_MAPPER(__BPF_ENUM_FN)
6104	__BPF_FUNC_MAX_ID,
6105};
6106#undef __BPF_ENUM_FN
6107
6108/* All flags used by eBPF helper functions, placed here. */
6109
6110/* BPF_FUNC_skb_store_bytes flags. */
6111enum {
6112	BPF_F_RECOMPUTE_CSUM		= (1ULL << 0),
6113	BPF_F_INVALIDATE_HASH		= (1ULL << 1),
6114};
6115
6116/* BPF_FUNC_l3_csum_replace and BPF_FUNC_l4_csum_replace flags.
6117 * First 4 bits are for passing the header field size.
6118 */
6119enum {
6120	BPF_F_HDR_FIELD_MASK		= 0xfULL,
6121};
6122
6123/* BPF_FUNC_l4_csum_replace flags. */
6124enum {
6125	BPF_F_PSEUDO_HDR		= (1ULL << 4),
6126	BPF_F_MARK_MANGLED_0		= (1ULL << 5),
6127	BPF_F_MARK_ENFORCE		= (1ULL << 6),
6128	BPF_F_IPV6			= (1ULL << 7),
6129};
6130
6131/* BPF_FUNC_skb_set_tunnel_key and BPF_FUNC_skb_get_tunnel_key flags. */
6132enum {
6133	BPF_F_TUNINFO_IPV6		= (1ULL << 0),
6134};
6135
6136/* flags for both BPF_FUNC_get_stackid and BPF_FUNC_get_stack. */
6137enum {
6138	BPF_F_SKIP_FIELD_MASK		= 0xffULL,
6139	BPF_F_USER_STACK		= (1ULL << 8),
6140/* flags used by BPF_FUNC_get_stackid only. */
6141	BPF_F_FAST_STACK_CMP		= (1ULL << 9),
6142	BPF_F_REUSE_STACKID		= (1ULL << 10),
6143/* flags used by BPF_FUNC_get_stack only. */
6144	BPF_F_USER_BUILD_ID		= (1ULL << 11),
6145};
6146
6147/* BPF_FUNC_skb_set_tunnel_key flags. */
6148enum {
6149	BPF_F_ZERO_CSUM_TX		= (1ULL << 1),
6150	BPF_F_DONT_FRAGMENT		= (1ULL << 2),
6151	BPF_F_SEQ_NUMBER		= (1ULL << 3),
6152	BPF_F_NO_TUNNEL_KEY		= (1ULL << 4),
6153};
6154
6155/* BPF_FUNC_skb_get_tunnel_key flags. */
6156enum {
6157	BPF_F_TUNINFO_FLAGS		= (1ULL << 4),
6158};
6159
6160/* BPF_FUNC_perf_event_output, BPF_FUNC_perf_event_read and
6161 * BPF_FUNC_perf_event_read_value flags.
6162 */
6163enum {
6164	BPF_F_INDEX_MASK		= 0xffffffffULL,
6165	BPF_F_CURRENT_CPU		= BPF_F_INDEX_MASK,
6166/* BPF_FUNC_perf_event_output for sk_buff input context. */
6167	BPF_F_CTXLEN_MASK		= (0xfffffULL << 32),
6168};
6169
6170/* Current network namespace */
6171enum {
6172	BPF_F_CURRENT_NETNS		= (-1L),
6173};
6174
6175/* BPF_FUNC_csum_level level values. */
6176enum {
6177	BPF_CSUM_LEVEL_QUERY,
6178	BPF_CSUM_LEVEL_INC,
6179	BPF_CSUM_LEVEL_DEC,
6180	BPF_CSUM_LEVEL_RESET,
6181};
6182
6183/* BPF_FUNC_skb_adjust_room flags. */
6184enum {
6185	BPF_F_ADJ_ROOM_FIXED_GSO	= (1ULL << 0),
6186	BPF_F_ADJ_ROOM_ENCAP_L3_IPV4	= (1ULL << 1),
6187	BPF_F_ADJ_ROOM_ENCAP_L3_IPV6	= (1ULL << 2),
6188	BPF_F_ADJ_ROOM_ENCAP_L4_GRE	= (1ULL << 3),
6189	BPF_F_ADJ_ROOM_ENCAP_L4_UDP	= (1ULL << 4),
6190	BPF_F_ADJ_ROOM_NO_CSUM_RESET	= (1ULL << 5),
6191	BPF_F_ADJ_ROOM_ENCAP_L2_ETH	= (1ULL << 6),
6192	BPF_F_ADJ_ROOM_DECAP_L3_IPV4	= (1ULL << 7),
6193	BPF_F_ADJ_ROOM_DECAP_L3_IPV6	= (1ULL << 8),
6194};
6195
6196enum {
6197	BPF_ADJ_ROOM_ENCAP_L2_MASK	= 0xff,
6198	BPF_ADJ_ROOM_ENCAP_L2_SHIFT	= 56,
6199};
6200
6201#define BPF_F_ADJ_ROOM_ENCAP_L2(len)	(((__u64)len & \
6202					  BPF_ADJ_ROOM_ENCAP_L2_MASK) \
6203					 << BPF_ADJ_ROOM_ENCAP_L2_SHIFT)
6204
6205/* BPF_FUNC_sysctl_get_name flags. */
6206enum {
6207	BPF_F_SYSCTL_BASE_NAME		= (1ULL << 0),
6208};
6209
6210/* BPF_FUNC_<kernel_obj>_storage_get flags */
6211enum {
6212	BPF_LOCAL_STORAGE_GET_F_CREATE	= (1ULL << 0),
6213	/* BPF_SK_STORAGE_GET_F_CREATE is only kept for backward compatibility
6214	 * and BPF_LOCAL_STORAGE_GET_F_CREATE must be used instead.
6215	 */
6216	BPF_SK_STORAGE_GET_F_CREATE  = BPF_LOCAL_STORAGE_GET_F_CREATE,
6217};
6218
6219/* BPF_FUNC_read_branch_records flags. */
6220enum {
6221	BPF_F_GET_BRANCH_RECORDS_SIZE	= (1ULL << 0),
6222};
6223
6224/* BPF_FUNC_bpf_ringbuf_commit, BPF_FUNC_bpf_ringbuf_discard, and
6225 * BPF_FUNC_bpf_ringbuf_output flags.
6226 */
6227enum {
6228	BPF_RB_NO_WAKEUP		= (1ULL << 0),
6229	BPF_RB_FORCE_WAKEUP		= (1ULL << 1),
6230};
6231
6232/* BPF_FUNC_bpf_ringbuf_query flags */
6233enum {
6234	BPF_RB_AVAIL_DATA = 0,
6235	BPF_RB_RING_SIZE = 1,
6236	BPF_RB_CONS_POS = 2,
6237	BPF_RB_PROD_POS = 3,
6238	BPF_RB_OVERWRITE_POS = 4,
6239};
6240
6241/* BPF ring buffer constants */
6242enum {
6243	BPF_RINGBUF_BUSY_BIT		= (1U << 31),
6244	BPF_RINGBUF_DISCARD_BIT		= (1U << 30),
6245	BPF_RINGBUF_HDR_SZ		= 8,
6246};
6247
6248/* BPF_FUNC_sk_assign flags in bpf_sk_lookup context. */
6249enum {
6250	BPF_SK_LOOKUP_F_REPLACE		= (1ULL << 0),
6251	BPF_SK_LOOKUP_F_NO_REUSEPORT	= (1ULL << 1),
6252};
6253
6254/* Mode for BPF_FUNC_skb_adjust_room helper. */
6255enum bpf_adj_room_mode {
6256	BPF_ADJ_ROOM_NET,
6257	BPF_ADJ_ROOM_MAC,
6258};
6259
6260/* Mode for BPF_FUNC_skb_load_bytes_relative helper. */
6261enum bpf_hdr_start_off {
6262	BPF_HDR_START_MAC,
6263	BPF_HDR_START_NET,
6264};
6265
6266/* Encapsulation type for BPF_FUNC_lwt_push_encap helper. */
6267enum bpf_lwt_encap_mode {
6268	BPF_LWT_ENCAP_SEG6,
6269	BPF_LWT_ENCAP_SEG6_INLINE,
6270	BPF_LWT_ENCAP_IP,
6271};
6272
6273/* Flags for bpf_bprm_opts_set helper */
6274enum {
6275	BPF_F_BPRM_SECUREEXEC	= (1ULL << 0),
6276};
6277
6278/* Flags for bpf_redirect and bpf_redirect_map helpers */
6279enum {
6280	BPF_F_INGRESS		= (1ULL << 0), /* used for skb path */
6281	BPF_F_BROADCAST		= (1ULL << 3), /* used for XDP path */
6282	BPF_F_EXCLUDE_INGRESS	= (1ULL << 4), /* used for XDP path */
6283#define BPF_F_REDIRECT_FLAGS (BPF_F_INGRESS | BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS)
6284};
6285
6286#define __bpf_md_ptr(type, name)	\
6287union {					\
6288	type name;			\
6289	__u64 :64;			\
6290} __attribute__((aligned(8)))
6291
6292/* The enum used in skb->tstamp_type. It specifies the clock type
6293 * of the time stored in the skb->tstamp.
6294 */
6295enum {
6296	BPF_SKB_TSTAMP_UNSPEC = 0,		/* DEPRECATED */
6297	BPF_SKB_TSTAMP_DELIVERY_MONO = 1,	/* DEPRECATED */
6298	BPF_SKB_CLOCK_REALTIME = 0,
6299	BPF_SKB_CLOCK_MONOTONIC = 1,
6300	BPF_SKB_CLOCK_TAI = 2,
6301	/* For any future BPF_SKB_CLOCK_* that the bpf prog cannot handle,
6302	 * the bpf prog can try to deduce it by ingress/egress/skb->sk->sk_clockid.
6303	 */
6304};
6305
6306/* user accessible mirror of in-kernel sk_buff.
6307 * new fields can only be added to the end of this structure
6308 */
6309struct __sk_buff {
6310	__u32 len;
6311	__u32 pkt_type;
6312	__u32 mark;
6313	__u32 queue_mapping;
6314	__u32 protocol;
6315	__u32 vlan_present;
6316	__u32 vlan_tci;
6317	__u32 vlan_proto;
6318	__u32 priority;
6319	__u32 ingress_ifindex;
6320	__u32 ifindex;
6321	__u32 tc_index;
6322	__u32 cb[5];
6323	__u32 hash;
6324	__u32 tc_classid;
6325	__u32 data;
6326	__u32 data_end;
6327	__u32 napi_id;
6328
6329	/* Accessed by BPF_PROG_TYPE_sk_skb types from here to ... */
6330	__u32 family;
6331	__u32 remote_ip4;	/* Stored in network byte order */
6332	__u32 local_ip4;	/* Stored in network byte order */
6333	__u32 remote_ip6[4];	/* Stored in network byte order */
6334	__u32 local_ip6[4];	/* Stored in network byte order */
6335	__u32 remote_port;	/* Stored in network byte order */
6336	__u32 local_port;	/* stored in host byte order */
6337	/* ... here. */
6338
6339	__u32 data_meta;
6340	__bpf_md_ptr(struct bpf_flow_keys *, flow_keys);
6341	__u64 tstamp;
6342	__u32 wire_len;
6343	__u32 gso_segs;
6344	__bpf_md_ptr(struct bpf_sock *, sk);
6345	__u32 gso_size;
6346	__u8  tstamp_type;
6347	__u32 :24;		/* Padding, future use. */
6348	__u64 hwtstamp;
6349};
6350
6351struct bpf_tunnel_key {
6352	__u32 tunnel_id;
6353	union {
6354		__u32 remote_ipv4;
6355		__u32 remote_ipv6[4];
6356	};
6357	__u8 tunnel_tos;
6358	__u8 tunnel_ttl;
6359	union {
6360		__u16 tunnel_ext;	/* compat */
6361		__be16 tunnel_flags;
6362	};
6363	__u32 tunnel_label;
6364	union {
6365		__u32 local_ipv4;
6366		__u32 local_ipv6[4];
6367	};
6368};
6369
6370/* user accessible mirror of in-kernel xfrm_state.
6371 * new fields can only be added to the end of this structure
6372 */
6373struct bpf_xfrm_state {
6374	__u32 reqid;
6375	__u32 spi;	/* Stored in network byte order */
6376	__u16 family;
6377	__u16 ext;	/* Padding, future use. */
6378	union {
6379		__u32 remote_ipv4;	/* Stored in network byte order */
6380		__u32 remote_ipv6[4];	/* Stored in network byte order */
6381	};
6382};
6383
6384/* Generic BPF return codes which all BPF program types may support.
6385 * The values are binary compatible with their TC_ACT_* counter-part to
6386 * provide backwards compatibility with existing SCHED_CLS and SCHED_ACT
6387 * programs.
6388 *
6389 * XDP is handled seprately, see XDP_*.
6390 */
6391enum bpf_ret_code {
6392	BPF_OK = 0,
6393	/* 1 reserved */
6394	BPF_DROP = 2,
6395	/* 3-6 reserved */
6396	BPF_REDIRECT = 7,
6397	/* >127 are reserved for prog type specific return codes.
6398	 *
6399	 * BPF_LWT_REROUTE: used by BPF_PROG_TYPE_LWT_IN and
6400	 *    BPF_PROG_TYPE_LWT_XMIT to indicate that skb had been
6401	 *    changed and should be routed based on its new L3 header.
6402	 *    (This is an L3 redirect, as opposed to L2 redirect
6403	 *    represented by BPF_REDIRECT above).
6404	 */
6405	BPF_LWT_REROUTE = 128,
6406	/* BPF_FLOW_DISSECTOR_CONTINUE: used by BPF_PROG_TYPE_FLOW_DISSECTOR
6407	 *   to indicate that no custom dissection was performed, and
6408	 *   fallback to standard dissector is requested.
6409	 */
6410	BPF_FLOW_DISSECTOR_CONTINUE = 129,
6411};
6412
6413struct bpf_sock {
6414	__u32 bound_dev_if;
6415	__u32 family;
6416	__u32 type;
6417	__u32 protocol;
6418	__u32 mark;
6419	__u32 priority;
6420	/* IP address also allows 1 and 2 bytes access */
6421	__u32 src_ip4;
6422	__u32 src_ip6[4];
6423	__u32 src_port;		/* host byte order */
6424	__be16 dst_port;	/* network byte order */
6425	__u16 :16;		/* zero padding */
6426	__u32 dst_ip4;
6427	__u32 dst_ip6[4];
6428	__u32 state;
6429	__s32 rx_queue_mapping;
6430};
6431
6432struct bpf_tcp_sock {
6433	__u32 snd_cwnd;		/* Sending congestion window		*/
6434	__u32 srtt_us;		/* smoothed round trip time << 3 in usecs */
6435	__u32 rtt_min;
6436	__u32 snd_ssthresh;	/* Slow start size threshold		*/
6437	__u32 rcv_nxt;		/* What we want to receive next		*/
6438	__u32 snd_nxt;		/* Next sequence we send		*/
6439	__u32 snd_una;		/* First byte we want an ack for	*/
6440	__u32 mss_cache;	/* Cached effective mss, not including SACKS */
6441	__u32 ecn_flags;	/* ECN status bits.			*/
6442	__u32 rate_delivered;	/* saved rate sample: packets delivered */
6443	__u32 rate_interval_us;	/* saved rate sample: time elapsed */
6444	__u32 packets_out;	/* Packets which are "in flight"	*/
6445	__u32 retrans_out;	/* Retransmitted packets out		*/
6446	__u32 total_retrans;	/* Total retransmits for entire connection */
6447	__u32 segs_in;		/* RFC4898 tcpEStatsPerfSegsIn
6448				 * total number of segments in.
6449				 */
6450	__u32 data_segs_in;	/* RFC4898 tcpEStatsPerfDataSegsIn
6451				 * total number of data segments in.
6452				 */
6453	__u32 segs_out;		/* RFC4898 tcpEStatsPerfSegsOut
6454				 * The total number of segments sent.
6455				 */
6456	__u32 data_segs_out;	/* RFC4898 tcpEStatsPerfDataSegsOut
6457				 * total number of data segments sent.
6458				 */
6459	__u32 lost_out;		/* Lost packets			*/
6460	__u32 sacked_out;	/* SACK'd packets			*/
6461	__u64 bytes_received;	/* RFC4898 tcpEStatsAppHCThruOctetsReceived
6462				 * sum(delta(rcv_nxt)), or how many bytes
6463				 * were acked.
6464				 */
6465	__u64 bytes_acked;	/* RFC4898 tcpEStatsAppHCThruOctetsAcked
6466				 * sum(delta(snd_una)), or how many bytes
6467				 * were acked.
6468				 */
6469	__u32 dsack_dups;	/* RFC4898 tcpEStatsStackDSACKDups
6470				 * total number of DSACK blocks received
6471				 */
6472	__u32 delivered;	/* Total data packets delivered incl. rexmits */
6473	__u32 delivered_ce;	/* Like the above but only ECE marked packets */
6474	__u32 icsk_retransmits;	/* Number of unrecovered [RTO] timeouts */
6475};
6476
6477struct bpf_sock_tuple {
6478	union {
6479		struct {
6480			__be32 saddr;
6481			__be32 daddr;
6482			__be16 sport;
6483			__be16 dport;
6484		} ipv4;
6485		struct {
6486			__be32 saddr[4];
6487			__be32 daddr[4];
6488			__be16 sport;
6489			__be16 dport;
6490		} ipv6;
6491	};
6492};
6493
6494/* (Simplified) user return codes for tcx prog type.
6495 * A valid tcx program must return one of these defined values. All other
6496 * return codes are reserved for future use. Must remain compatible with
6497 * their TC_ACT_* counter-parts. For compatibility in behavior, unknown
6498 * return codes are mapped to TCX_NEXT.
6499 */
6500enum tcx_action_base {
6501	TCX_NEXT	= -1,
6502	TCX_PASS	= 0,
6503	TCX_DROP	= 2,
6504	TCX_REDIRECT	= 7,
6505};
6506
6507struct bpf_xdp_sock {
6508	__u32 queue_id;
6509};
6510
6511#define XDP_PACKET_HEADROOM 256
6512
6513/* User return codes for XDP prog type.
6514 * A valid XDP program must return one of these defined values. All other
6515 * return codes are reserved for future use. Unknown return codes will
6516 * result in packet drops and a warning via bpf_warn_invalid_xdp_action().
6517 */
6518enum xdp_action {
6519	XDP_ABORTED = 0,
6520	XDP_DROP,
6521	XDP_PASS,
6522	XDP_TX,
6523	XDP_REDIRECT,
6524};
6525
6526/* user accessible metadata for XDP packet hook
6527 * new fields must be added to the end of this structure
6528 */
6529struct xdp_md {
6530	__u32 data;
6531	__u32 data_end;
6532	__u32 data_meta;
6533	/* Below access go through struct xdp_rxq_info */
6534	__u32 ingress_ifindex; /* rxq->dev->ifindex */
6535	__u32 rx_queue_index;  /* rxq->queue_index  */
6536
6537	__u32 egress_ifindex;  /* txq->dev->ifindex */
6538};
6539
6540/* DEVMAP map-value layout
6541 *
6542 * The struct data-layout of map-value is a configuration interface.
6543 * New members can only be added to the end of this structure.
6544 */
6545struct bpf_devmap_val {
6546	__u32 ifindex;   /* device index */
6547	union {
6548		int   fd;  /* prog fd on map write */
6549		__u32 id;  /* prog id on map read */
6550	} bpf_prog;
6551};
6552
6553/* CPUMAP map-value layout
6554 *
6555 * The struct data-layout of map-value is a configuration interface.
6556 * New members can only be added to the end of this structure.
6557 */
6558struct bpf_cpumap_val {
6559	__u32 qsize;	/* queue size to remote target CPU */
6560	union {
6561		int   fd;	/* prog fd on map write */
6562		__u32 id;	/* prog id on map read */
6563	} bpf_prog;
6564};
6565
6566enum sk_action {
6567	SK_DROP = 0,
6568	SK_PASS,
6569};
6570
6571/* user accessible metadata for SK_MSG packet hook, new fields must
6572 * be added to the end of this structure
6573 */
6574struct sk_msg_md {
6575	__bpf_md_ptr(void *, data);
6576	__bpf_md_ptr(void *, data_end);
6577
6578	__u32 family;
6579	__u32 remote_ip4;	/* Stored in network byte order */
6580	__u32 local_ip4;	/* Stored in network byte order */
6581	__u32 remote_ip6[4];	/* Stored in network byte order */
6582	__u32 local_ip6[4];	/* Stored in network byte order */
6583	__u32 remote_port;	/* Stored in network byte order */
6584	__u32 local_port;	/* stored in host byte order */
6585	__u32 size;		/* Total size of sk_msg */
6586
6587	__bpf_md_ptr(struct bpf_sock *, sk); /* current socket */
6588};
6589
6590struct sk_reuseport_md {
6591	/*
6592	 * Start of directly accessible data. It begins from
6593	 * the tcp/udp header.
6594	 */
6595	__bpf_md_ptr(void *, data);
6596	/* End of directly accessible data */
6597	__bpf_md_ptr(void *, data_end);
6598	/*
6599	 * Total length of packet (starting from the tcp/udp header).
6600	 * Note that the directly accessible bytes (data_end - data)
6601	 * could be less than this "len".  Those bytes could be
6602	 * indirectly read by a helper "bpf_skb_load_bytes()".
6603	 */
6604	__u32 len;
6605	/*
6606	 * Eth protocol in the mac header (network byte order). e.g.
6607	 * ETH_P_IP(0x0800) and ETH_P_IPV6(0x86DD)
6608	 */
6609	__u32 eth_protocol;
6610	__u32 ip_protocol;	/* IP protocol. e.g. IPPROTO_TCP, IPPROTO_UDP */
6611	__u32 bind_inany;	/* Is sock bound to an INANY address? */
6612	__u32 hash;		/* A hash of the packet 4 tuples */
6613	/* When reuse->migrating_sk is NULL, it is selecting a sk for the
6614	 * new incoming connection request (e.g. selecting a listen sk for
6615	 * the received SYN in the TCP case).  reuse->sk is one of the sk
6616	 * in the reuseport group. The bpf prog can use reuse->sk to learn
6617	 * the local listening ip/port without looking into the skb.
6618	 *
6619	 * When reuse->migrating_sk is not NULL, reuse->sk is closed and
6620	 * reuse->migrating_sk is the socket that needs to be migrated
6621	 * to another listening socket.  migrating_sk could be a fullsock
6622	 * sk that is fully established or a reqsk that is in-the-middle
6623	 * of 3-way handshake.
6624	 */
6625	__bpf_md_ptr(struct bpf_sock *, sk);
6626	__bpf_md_ptr(struct bpf_sock *, migrating_sk);
6627};
6628
6629#define BPF_TAG_SIZE	8
6630
6631struct bpf_prog_info {
6632	__u32 type;
6633	__u32 id;
6634	__u8  tag[BPF_TAG_SIZE];
6635	__u32 jited_prog_len;
6636	__u32 xlated_prog_len;
6637	__aligned_u64 jited_prog_insns;
6638	__aligned_u64 xlated_prog_insns;
6639	__u64 load_time;	/* ns since boottime */
6640	__u32 created_by_uid;
6641	__u32 nr_map_ids;
6642	__aligned_u64 map_ids;
6643	char name[BPF_OBJ_NAME_LEN];
6644	__u32 ifindex;
6645	__u32 gpl_compatible:1;
6646	__u32 :31; /* alignment pad */
6647	__u64 netns_dev;
6648	__u64 netns_ino;
6649	__u32 nr_jited_ksyms;
6650	__u32 nr_jited_func_lens;
6651	__aligned_u64 jited_ksyms;
6652	__aligned_u64 jited_func_lens;
6653	__u32 btf_id;
6654	__u32 func_info_rec_size;
6655	__aligned_u64 func_info;
6656	__u32 nr_func_info;
6657	__u32 nr_line_info;
6658	__aligned_u64 line_info;
6659	__aligned_u64 jited_line_info;
6660	__u32 nr_jited_line_info;
6661	__u32 line_info_rec_size;
6662	__u32 jited_line_info_rec_size;
6663	__u32 nr_prog_tags;
6664	__aligned_u64 prog_tags;
6665	__u64 run_time_ns;
6666	__u64 run_cnt;
6667	__u64 recursion_misses;
6668	__u32 verified_insns;
6669	__u32 attach_btf_obj_id;
6670	__u32 attach_btf_id;
6671} __attribute__((aligned(8)));
6672
6673struct bpf_map_info {
6674	__u32 type;
6675	__u32 id;
6676	__u32 key_size;
6677	__u32 value_size;
6678	__u32 max_entries;
6679	__u32 map_flags;
6680	char  name[BPF_OBJ_NAME_LEN];
6681	__u32 ifindex;
6682	__u32 btf_vmlinux_value_type_id;
6683	__u64 netns_dev;
6684	__u64 netns_ino;
6685	__u32 btf_id;
6686	__u32 btf_key_type_id;
6687	__u32 btf_value_type_id;
6688	__u32 btf_vmlinux_id;
6689	__u64 map_extra;
6690	__aligned_u64 hash;
6691	__u32 hash_size;
6692} __attribute__((aligned(8)));
6693
6694struct bpf_btf_info {
6695	__aligned_u64 btf;
6696	__u32 btf_size;
6697	__u32 id;
6698	__aligned_u64 name;
6699	__u32 name_len;
6700	__u32 kernel_btf;
6701} __attribute__((aligned(8)));
6702
6703struct bpf_link_info {
6704	__u32 type;
6705	__u32 id;
6706	__u32 prog_id;
6707	union {
6708		struct {
6709			__aligned_u64 tp_name; /* in/out: tp_name buffer ptr */
6710			__u32 tp_name_len;     /* in/out: tp_name buffer len */
6711			__u32 :32;
6712			__u64 cookie;
6713		} raw_tracepoint;
6714		struct {
6715			__u32 attach_type;
6716			__u32 target_obj_id; /* prog_id for PROG_EXT, otherwise btf object id */
6717			__u32 target_btf_id; /* BTF type id inside the object */
6718			__u32 :32;
6719			__u64 cookie;
6720		} tracing;
6721		struct {
6722			__u64 cgroup_id;
6723			__u32 attach_type;
6724		} cgroup;
6725		struct {
6726			__aligned_u64 target_name; /* in/out: target_name buffer ptr */
6727			__u32 target_name_len;	   /* in/out: target_name buffer len */
6728
6729			/* If the iter specific field is 32 bits, it can be put
6730			 * in the first or second union. Otherwise it should be
6731			 * put in the second union.
6732			 */
6733			union {
6734				struct {
6735					__u32 map_id;
6736				} map;
6737			};
6738			union {
6739				struct {
6740					__u64 cgroup_id;
6741					__u32 order;
6742				} cgroup;
6743				struct {
6744					__u32 tid;
6745					__u32 pid;
6746				} task;
6747			};
6748		} iter;
6749		struct  {
6750			__u32 netns_ino;
6751			__u32 attach_type;
6752		} netns;
6753		struct {
6754			__u32 ifindex;
6755		} xdp;
6756		struct {
6757			__u32 map_id;
6758		} struct_ops;
6759		struct {
6760			__u32 pf;
6761			__u32 hooknum;
6762			__s32 priority;
6763			__u32 flags;
6764		} netfilter;
6765		struct {
6766			__aligned_u64 addrs;
6767			__u32 count; /* in/out: kprobe_multi function count */
6768			__u32 flags;
6769			__u64 missed;
6770			__aligned_u64 cookies;
6771		} kprobe_multi;
6772		struct {
6773			__aligned_u64 path;
6774			__aligned_u64 offsets;
6775			__aligned_u64 ref_ctr_offsets;
6776			__aligned_u64 cookies;
6777			__u32 path_size; /* in/out: real path size on success, including zero byte */
6778			__u32 count; /* in/out: uprobe_multi offsets/ref_ctr_offsets/cookies count */
6779			__u32 flags;
6780			__u32 pid;
6781		} uprobe_multi;
6782		struct {
6783			__u32 type; /* enum bpf_perf_event_type */
6784			__u32 :32;
6785			union {
6786				struct {
6787					__aligned_u64 file_name; /* in/out */
6788					__u32 name_len;
6789					__u32 offset; /* offset from file_name */
6790					__u64 cookie;
6791					__u64 ref_ctr_offset;
6792				} uprobe; /* BPF_PERF_EVENT_UPROBE, BPF_PERF_EVENT_URETPROBE */
6793				struct {
6794					__aligned_u64 func_name; /* in/out */
6795					__u32 name_len;
6796					__u32 offset; /* offset from func_name */
6797					__u64 addr;
6798					__u64 missed;
6799					__u64 cookie;
6800				} kprobe; /* BPF_PERF_EVENT_KPROBE, BPF_PERF_EVENT_KRETPROBE */
6801				struct {
6802					__aligned_u64 tp_name;   /* in/out */
6803					__u32 name_len;
6804					__u32 :32;
6805					__u64 cookie;
6806				} tracepoint; /* BPF_PERF_EVENT_TRACEPOINT */
6807				struct {
6808					__u64 config;
6809					__u32 type;
6810					__u32 :32;
6811					__u64 cookie;
6812				} event; /* BPF_PERF_EVENT_EVENT */
6813			};
6814		} perf_event;
6815		struct {
6816			__u32 ifindex;
6817			__u32 attach_type;
6818		} tcx;
6819		struct {
6820			__u32 ifindex;
6821			__u32 attach_type;
6822		} netkit;
6823		struct {
6824			__u32 map_id;
6825			__u32 attach_type;
6826		} sockmap;
6827	};
6828} __attribute__((aligned(8)));
6829
6830struct bpf_token_info {
6831	__u64 allowed_cmds;
6832	__u64 allowed_maps;
6833	__u64 allowed_progs;
6834	__u64 allowed_attachs;
6835} __attribute__((aligned(8)));
6836
6837/* User bpf_sock_addr struct to access socket fields and sockaddr struct passed
6838 * by user and intended to be used by socket (e.g. to bind to, depends on
6839 * attach type).
6840 */
6841struct bpf_sock_addr {
6842	__u32 user_family;	/* Allows 4-byte read, but no write. */
6843	__u32 user_ip4;		/* Allows 1,2,4-byte read and 4-byte write.
6844				 * Stored in network byte order.
6845				 */
6846	__u32 user_ip6[4];	/* Allows 1,2,4,8-byte read and 4,8-byte write.
6847				 * Stored in network byte order.
6848				 */
6849	__u32 user_port;	/* Allows 1,2,4-byte read and 4-byte write.
6850				 * Stored in network byte order
6851				 */
6852	__u32 family;		/* Allows 4-byte read, but no write */
6853	__u32 type;		/* Allows 4-byte read, but no write */
6854	__u32 protocol;		/* Allows 4-byte read, but no write */
6855	__u32 msg_src_ip4;	/* Allows 1,2,4-byte read and 4-byte write.
6856				 * Stored in network byte order.
6857				 */
6858	__u32 msg_src_ip6[4];	/* Allows 1,2,4,8-byte read and 4,8-byte write.
6859				 * Stored in network byte order.
6860				 */
6861	__bpf_md_ptr(struct bpf_sock *, sk);
6862};
6863
6864/* User bpf_sock_ops struct to access socket values and specify request ops
6865 * and their replies.
6866 * Some of this fields are in network (bigendian) byte order and may need
6867 * to be converted before use (bpf_ntohl() defined in samples/bpf/bpf_endian.h).
6868 * New fields can only be added at the end of this structure
6869 */
6870struct bpf_sock_ops {
6871	__u32 op;
6872	union {
6873		__u32 args[4];		/* Optionally passed to bpf program */
6874		__u32 reply;		/* Returned by bpf program	    */
6875		__u32 replylong[4];	/* Optionally returned by bpf prog  */
6876	};
6877	__u32 family;
6878	__u32 remote_ip4;	/* Stored in network byte order */
6879	__u32 local_ip4;	/* Stored in network byte order */
6880	__u32 remote_ip6[4];	/* Stored in network byte order */
6881	__u32 local_ip6[4];	/* Stored in network byte order */
6882	__u32 remote_port;	/* Stored in network byte order */
6883	__u32 local_port;	/* stored in host byte order */
6884	__u32 is_fullsock;	/* Some TCP fields are only valid if
6885				 * there is a full socket. If not, the
6886				 * fields read as zero.
6887				 */
6888	__u32 snd_cwnd;
6889	__u32 srtt_us;		/* Averaged RTT << 3 in usecs */
6890	__u32 bpf_sock_ops_cb_flags; /* flags defined in uapi/linux/tcp.h */
6891	__u32 state;
6892	__u32 rtt_min;
6893	__u32 snd_ssthresh;
6894	__u32 rcv_nxt;
6895	__u32 snd_nxt;
6896	__u32 snd_una;
6897	__u32 mss_cache;
6898	__u32 ecn_flags;
6899	__u32 rate_delivered;
6900	__u32 rate_interval_us;
6901	__u32 packets_out;
6902	__u32 retrans_out;
6903	__u32 total_retrans;
6904	__u32 segs_in;
6905	__u32 data_segs_in;
6906	__u32 segs_out;
6907	__u32 data_segs_out;
6908	__u32 lost_out;
6909	__u32 sacked_out;
6910	__u32 sk_txhash;
6911	__u64 bytes_received;
6912	__u64 bytes_acked;
6913	__bpf_md_ptr(struct bpf_sock *, sk);
6914	/* [skb_data, skb_data_end) covers the whole TCP header.
6915	 *
6916	 * BPF_SOCK_OPS_PARSE_HDR_OPT_CB: The packet received
6917	 * BPF_SOCK_OPS_HDR_OPT_LEN_CB:   Not useful because the
6918	 *                                header has not been written.
6919	 * BPF_SOCK_OPS_WRITE_HDR_OPT_CB: The header and options have
6920	 *				  been written so far.
6921	 * BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:  The SYNACK that concludes
6922	 *					the 3WHS.
6923	 * BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB: The ACK that concludes
6924	 *					the 3WHS.
6925	 *
6926	 * bpf_load_hdr_opt() can also be used to read a particular option.
6927	 */
6928	__bpf_md_ptr(void *, skb_data);
6929	__bpf_md_ptr(void *, skb_data_end);
6930	__u32 skb_len;		/* The total length of a packet.
6931				 * It includes the header, options,
6932				 * and payload.
6933				 */
6934	__u32 skb_tcp_flags;	/* tcp_flags of the header.  It provides
6935				 * an easy way to check for tcp_flags
6936				 * without parsing skb_data.
6937				 *
6938				 * In particular, the skb_tcp_flags
6939				 * will still be available in
6940				 * BPF_SOCK_OPS_HDR_OPT_LEN even though
6941				 * the outgoing header has not
6942				 * been written yet.
6943				 */
6944	__u64 skb_hwtstamp;
6945};
6946
6947/* Definitions for bpf_sock_ops_cb_flags */
6948enum {
6949	BPF_SOCK_OPS_RTO_CB_FLAG	= (1<<0),
6950	BPF_SOCK_OPS_RETRANS_CB_FLAG	= (1<<1),
6951	BPF_SOCK_OPS_STATE_CB_FLAG	= (1<<2),
6952	BPF_SOCK_OPS_RTT_CB_FLAG	= (1<<3),
6953	/* Call bpf for all received TCP headers.  The bpf prog will be
6954	 * called under sock_ops->op == BPF_SOCK_OPS_PARSE_HDR_OPT_CB
6955	 *
6956	 * Please refer to the comment in BPF_SOCK_OPS_PARSE_HDR_OPT_CB
6957	 * for the header option related helpers that will be useful
6958	 * to the bpf programs.
6959	 *
6960	 * It could be used at the client/active side (i.e. connect() side)
6961	 * when the server told it that the server was in syncookie
6962	 * mode and required the active side to resend the bpf-written
6963	 * options.  The active side can keep writing the bpf-options until
6964	 * it received a valid packet from the server side to confirm
6965	 * the earlier packet (and options) has been received.  The later
6966	 * example patch is using it like this at the active side when the
6967	 * server is in syncookie mode.
6968	 *
6969	 * The bpf prog will usually turn this off in the common cases.
6970	 */
6971	BPF_SOCK_OPS_PARSE_ALL_HDR_OPT_CB_FLAG	= (1<<4),
6972	/* Call bpf when kernel has received a header option that
6973	 * the kernel cannot handle.  The bpf prog will be called under
6974	 * sock_ops->op == BPF_SOCK_OPS_PARSE_HDR_OPT_CB.
6975	 *
6976	 * Please refer to the comment in BPF_SOCK_OPS_PARSE_HDR_OPT_CB
6977	 * for the header option related helpers that will be useful
6978	 * to the bpf programs.
6979	 */
6980	BPF_SOCK_OPS_PARSE_UNKNOWN_HDR_OPT_CB_FLAG = (1<<5),
6981	/* Call bpf when the kernel is writing header options for the
6982	 * outgoing packet.  The bpf prog will first be called
6983	 * to reserve space in a skb under
6984	 * sock_ops->op == BPF_SOCK_OPS_HDR_OPT_LEN_CB.  Then
6985	 * the bpf prog will be called to write the header option(s)
6986	 * under sock_ops->op == BPF_SOCK_OPS_WRITE_HDR_OPT_CB.
6987	 *
6988	 * Please refer to the comment in BPF_SOCK_OPS_HDR_OPT_LEN_CB
6989	 * and BPF_SOCK_OPS_WRITE_HDR_OPT_CB for the header option
6990	 * related helpers that will be useful to the bpf programs.
6991	 *
6992	 * The kernel gets its chance to reserve space and write
6993	 * options first before the BPF program does.
6994	 */
6995	BPF_SOCK_OPS_WRITE_HDR_OPT_CB_FLAG = (1<<6),
6996/* Mask of all currently supported cb flags */
6997	BPF_SOCK_OPS_ALL_CB_FLAGS       = 0x7F,
6998};
6999
7000enum {
7001	SK_BPF_CB_TX_TIMESTAMPING	= 1<<0,
7002	SK_BPF_CB_MASK			= (SK_BPF_CB_TX_TIMESTAMPING - 1) |
7003					   SK_BPF_CB_TX_TIMESTAMPING
7004};
7005
7006/* List of known BPF sock_ops operators.
7007 * New entries can only be added at the end
7008 */
7009enum {
7010	BPF_SOCK_OPS_VOID,
7011	BPF_SOCK_OPS_TIMEOUT_INIT,	/* Should return SYN-RTO value to use or
7012					 * -1 if default value should be used
7013					 */
7014	BPF_SOCK_OPS_RWND_INIT,		/* Should return initial advertized
7015					 * window (in packets) or -1 if default
7016					 * value should be used
7017					 */
7018	BPF_SOCK_OPS_TCP_CONNECT_CB,	/* Calls BPF program right before an
7019					 * active connection is initialized
7020					 */
7021	BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB,	/* Calls BPF program when an
7022						 * active connection is
7023						 * established
7024						 */
7025	BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB,	/* Calls BPF program when a
7026						 * passive connection is
7027						 * established
7028						 */
7029	BPF_SOCK_OPS_NEEDS_ECN,		/* If connection's congestion control
7030					 * needs ECN
7031					 */
7032	BPF_SOCK_OPS_BASE_RTT,		/* Get base RTT. The correct value is
7033					 * based on the path and may be
7034					 * dependent on the congestion control
7035					 * algorithm. In general it indicates
7036					 * a congestion threshold. RTTs above
7037					 * this indicate congestion
7038					 */
7039	BPF_SOCK_OPS_RTO_CB,		/* Called when an RTO has triggered.
7040					 * Arg1: value of icsk_retransmits
7041					 * Arg2: value of icsk_rto
7042					 * Arg3: whether RTO has expired
7043					 */
7044	BPF_SOCK_OPS_RETRANS_CB,	/* Called when skb is retransmitted.
7045					 * Arg1: sequence number of 1st byte
7046					 * Arg2: # segments
7047					 * Arg3: return value of
7048					 *       tcp_transmit_skb (0 => success)
7049					 */
7050	BPF_SOCK_OPS_STATE_CB,		/* Called when TCP changes state.
7051					 * Arg1: old_state
7052					 * Arg2: new_state
7053					 */
7054	BPF_SOCK_OPS_TCP_LISTEN_CB,	/* Called on listen(2), right after
7055					 * socket transition to LISTEN state.
7056					 */
7057	BPF_SOCK_OPS_RTT_CB,		/* Called on every RTT.
7058					 * Arg1: measured RTT input (mrtt)
7059					 * Arg2: updated srtt
7060					 */
7061	BPF_SOCK_OPS_PARSE_HDR_OPT_CB,	/* Parse the header option.
7062					 * It will be called to handle
7063					 * the packets received at
7064					 * an already established
7065					 * connection.
7066					 *
7067					 * sock_ops->skb_data:
7068					 * Referring to the received skb.
7069					 * It covers the TCP header only.
7070					 *
7071					 * bpf_load_hdr_opt() can also
7072					 * be used to search for a
7073					 * particular option.
7074					 */
7075	BPF_SOCK_OPS_HDR_OPT_LEN_CB,	/* Reserve space for writing the
7076					 * header option later in
7077					 * BPF_SOCK_OPS_WRITE_HDR_OPT_CB.
7078					 * Arg1: bool want_cookie. (in
7079					 *       writing SYNACK only)
7080					 *
7081					 * sock_ops->skb_data:
7082					 * Not available because no header has
7083					 * been	written yet.
7084					 *
7085					 * sock_ops->skb_tcp_flags:
7086					 * The tcp_flags of the
7087					 * outgoing skb. (e.g. SYN, ACK, FIN).
7088					 *
7089					 * bpf_reserve_hdr_opt() should
7090					 * be used to reserve space.
7091					 */
7092	BPF_SOCK_OPS_WRITE_HDR_OPT_CB,	/* Write the header options
7093					 * Arg1: bool want_cookie. (in
7094					 *       writing SYNACK only)
7095					 *
7096					 * sock_ops->skb_data:
7097					 * Referring to the outgoing skb.
7098					 * It covers the TCP header
7099					 * that has already been written
7100					 * by the kernel and the
7101					 * earlier bpf-progs.
7102					 *
7103					 * sock_ops->skb_tcp_flags:
7104					 * The tcp_flags of the outgoing
7105					 * skb. (e.g. SYN, ACK, FIN).
7106					 *
7107					 * bpf_store_hdr_opt() should
7108					 * be used to write the
7109					 * option.
7110					 *
7111					 * bpf_load_hdr_opt() can also
7112					 * be used to search for a
7113					 * particular option that
7114					 * has already been written
7115					 * by the kernel or the
7116					 * earlier bpf-progs.
7117					 */
7118	BPF_SOCK_OPS_TSTAMP_SCHED_CB,	/* Called when skb is passing
7119					 * through dev layer when
7120					 * SK_BPF_CB_TX_TIMESTAMPING
7121					 * feature is on.
7122					 */
7123	BPF_SOCK_OPS_TSTAMP_SND_SW_CB,	/* Called when skb is about to send
7124					 * to the nic when SK_BPF_CB_TX_TIMESTAMPING
7125					 * feature is on.
7126					 */
7127	BPF_SOCK_OPS_TSTAMP_SND_HW_CB,	/* Called in hardware phase when
7128					 * SK_BPF_CB_TX_TIMESTAMPING feature
7129					 * is on.
7130					 */
7131	BPF_SOCK_OPS_TSTAMP_ACK_CB,	/* Called when all the skbs in the
7132					 * same sendmsg call are acked
7133					 * when SK_BPF_CB_TX_TIMESTAMPING
7134					 * feature is on.
7135					 */
7136	BPF_SOCK_OPS_TSTAMP_SENDMSG_CB,	/* Called when every sendmsg syscall
7137					 * is triggered. It's used to correlate
7138					 * sendmsg timestamp with corresponding
7139					 * tskey.
7140					 */
7141};
7142
7143/* List of TCP states. There is a build check in net/ipv4/tcp.c to detect
7144 * changes between the TCP and BPF versions. Ideally this should never happen.
7145 * If it does, we need to add code to convert them before calling
7146 * the BPF sock_ops function.
7147 */
7148enum {
7149	BPF_TCP_ESTABLISHED = 1,
7150	BPF_TCP_SYN_SENT,
7151	BPF_TCP_SYN_RECV,
7152	BPF_TCP_FIN_WAIT1,
7153	BPF_TCP_FIN_WAIT2,
7154	BPF_TCP_TIME_WAIT,
7155	BPF_TCP_CLOSE,
7156	BPF_TCP_CLOSE_WAIT,
7157	BPF_TCP_LAST_ACK,
7158	BPF_TCP_LISTEN,
7159	BPF_TCP_CLOSING,	/* Now a valid state */
7160	BPF_TCP_NEW_SYN_RECV,
7161	BPF_TCP_BOUND_INACTIVE,
7162
7163	BPF_TCP_MAX_STATES	/* Leave at the end! */
7164};
7165
7166enum {
7167	TCP_BPF_IW		= 1001,	/* Set TCP initial congestion window */
7168	TCP_BPF_SNDCWND_CLAMP	= 1002,	/* Set sndcwnd_clamp */
7169	TCP_BPF_DELACK_MAX	= 1003, /* Max delay ack in usecs */
7170	TCP_BPF_RTO_MIN		= 1004, /* Min delay ack in usecs */
7171	/* Copy the SYN pkt to optval
7172	 *
7173	 * BPF_PROG_TYPE_SOCK_OPS only.  It is similar to the
7174	 * bpf_getsockopt(TCP_SAVED_SYN) but it does not limit
7175	 * to only getting from the saved_syn.  It can either get the
7176	 * syn packet from:
7177	 *
7178	 * 1. the just-received SYN packet (only available when writing the
7179	 *    SYNACK).  It will be useful when it is not necessary to
7180	 *    save the SYN packet for latter use.  It is also the only way
7181	 *    to get the SYN during syncookie mode because the syn
7182	 *    packet cannot be saved during syncookie.
7183	 *
7184	 * OR
7185	 *
7186	 * 2. the earlier saved syn which was done by
7187	 *    bpf_setsockopt(TCP_SAVE_SYN).
7188	 *
7189	 * The bpf_getsockopt(TCP_BPF_SYN*) option will hide where the
7190	 * SYN packet is obtained.
7191	 *
7192	 * If the bpf-prog does not need the IP[46] header,  the
7193	 * bpf-prog can avoid parsing the IP header by using
7194	 * TCP_BPF_SYN.  Otherwise, the bpf-prog can get both
7195	 * IP[46] and TCP header by using TCP_BPF_SYN_IP.
7196	 *
7197	 *      >0: Total number of bytes copied
7198	 * -ENOSPC: Not enough space in optval. Only optlen number of
7199	 *          bytes is copied.
7200	 * -ENOENT: The SYN skb is not available now and the earlier SYN pkt
7201	 *	    is not saved by setsockopt(TCP_SAVE_SYN).
7202	 */
7203	TCP_BPF_SYN		= 1005, /* Copy the TCP header */
7204	TCP_BPF_SYN_IP		= 1006, /* Copy the IP[46] and TCP header */
7205	TCP_BPF_SYN_MAC         = 1007, /* Copy the MAC, IP[46], and TCP header */
7206	TCP_BPF_SOCK_OPS_CB_FLAGS = 1008, /* Get or Set TCP sock ops flags */
7207	SK_BPF_CB_FLAGS		= 1009, /* Get or set sock ops flags in socket */
7208	SK_BPF_BYPASS_PROT_MEM	= 1010, /* Get or Set sk->sk_bypass_prot_mem */
7209};
7210
7211enum {
7212	BPF_LOAD_HDR_OPT_TCP_SYN = (1ULL << 0),
7213};
7214
7215/* args[0] value during BPF_SOCK_OPS_HDR_OPT_LEN_CB and
7216 * BPF_SOCK_OPS_WRITE_HDR_OPT_CB.
7217 */
7218enum {
7219	BPF_WRITE_HDR_TCP_CURRENT_MSS = 1,	/* Kernel is finding the
7220						 * total option spaces
7221						 * required for an established
7222						 * sk in order to calculate the
7223						 * MSS.  No skb is actually
7224						 * sent.
7225						 */
7226	BPF_WRITE_HDR_TCP_SYNACK_COOKIE = 2,	/* Kernel is in syncookie mode
7227						 * when sending a SYN.
7228						 */
7229};
7230
7231struct bpf_perf_event_value {
7232	__u64 counter;
7233	__u64 enabled;
7234	__u64 running;
7235};
7236
7237enum {
7238	BPF_DEVCG_ACC_MKNOD	= (1ULL << 0),
7239	BPF_DEVCG_ACC_READ	= (1ULL << 1),
7240	BPF_DEVCG_ACC_WRITE	= (1ULL << 2),
7241};
7242
7243enum {
7244	BPF_DEVCG_DEV_BLOCK	= (1ULL << 0),
7245	BPF_DEVCG_DEV_CHAR	= (1ULL << 1),
7246};
7247
7248struct bpf_cgroup_dev_ctx {
7249	/* access_type encoded as (BPF_DEVCG_ACC_* << 16) | BPF_DEVCG_DEV_* */
7250	__u32 access_type;
7251	__u32 major;
7252	__u32 minor;
7253};
7254
7255struct bpf_raw_tracepoint_args {
7256	__u64 args[0];
7257};
7258
7259/* DIRECT:  Skip the FIB rules and go to FIB table associated with device
7260 * OUTPUT:  Do lookup from egress perspective; default is ingress
7261 */
7262enum {
7263	BPF_FIB_LOOKUP_DIRECT  = (1U << 0),
7264	BPF_FIB_LOOKUP_OUTPUT  = (1U << 1),
7265	BPF_FIB_LOOKUP_SKIP_NEIGH = (1U << 2),
7266	BPF_FIB_LOOKUP_TBID    = (1U << 3),
7267	BPF_FIB_LOOKUP_SRC     = (1U << 4),
7268	BPF_FIB_LOOKUP_MARK    = (1U << 5),
7269};
7270
7271enum {
7272	BPF_FIB_LKUP_RET_SUCCESS,      /* lookup successful */
7273	BPF_FIB_LKUP_RET_BLACKHOLE,    /* dest is blackholed; can be dropped */
7274	BPF_FIB_LKUP_RET_UNREACHABLE,  /* dest is unreachable; can be dropped */
7275	BPF_FIB_LKUP_RET_PROHIBIT,     /* dest not allowed; can be dropped */
7276	BPF_FIB_LKUP_RET_NOT_FWDED,    /* packet is not forwarded */
7277	BPF_FIB_LKUP_RET_FWD_DISABLED, /* fwding is not enabled on ingress */
7278	BPF_FIB_LKUP_RET_UNSUPP_LWT,   /* fwd requires encapsulation */
7279	BPF_FIB_LKUP_RET_NO_NEIGH,     /* no neighbor entry for nh */
7280	BPF_FIB_LKUP_RET_FRAG_NEEDED,  /* fragmentation required to fwd */
7281	BPF_FIB_LKUP_RET_NO_SRC_ADDR,  /* failed to derive IP src addr */
7282};
7283
7284struct bpf_fib_lookup {
7285	/* input:  network family for lookup (AF_INET, AF_INET6)
7286	 * output: network family of egress nexthop
7287	 */
7288	__u8	family;
7289
7290	/* set if lookup is to consider L4 data - e.g., FIB rules */
7291	__u8	l4_protocol;
7292	__be16	sport;
7293	__be16	dport;
7294
7295	union {	/* used for MTU check */
7296		/* input to lookup */
7297		__u16	tot_len; /* L3 length from network hdr (iph->tot_len) */
7298
7299		/* output: MTU value */
7300		__u16	mtu_result;
7301	} __attribute__((packed, aligned(2)));
7302	/* input: L3 device index for lookup
7303	 * output: device index from FIB lookup
7304	 */
7305	__u32	ifindex;
7306
7307	union {
7308		/* inputs to lookup */
7309		__u8	tos;		/* AF_INET  */
7310		__be32	flowinfo;	/* AF_INET6, flow_label + priority */
7311
7312		/* output: metric of fib result (IPv4/IPv6 only) */
7313		__u32	rt_metric;
7314	};
7315
7316	/* input: source address to consider for lookup
7317	 * output: source address result from lookup
7318	 */
7319	union {
7320		__be32		ipv4_src;
7321		__u32		ipv6_src[4];  /* in6_addr; network order */
7322	};
7323
7324	/* input to bpf_fib_lookup, ipv{4,6}_dst is destination address in
7325	 * network header. output: bpf_fib_lookup sets to gateway address
7326	 * if FIB lookup returns gateway route
7327	 */
7328	union {
7329		__be32		ipv4_dst;
7330		__u32		ipv6_dst[4];  /* in6_addr; network order */
7331	};
7332
7333	union {
7334		struct {
7335			/* output */
7336			__be16	h_vlan_proto;
7337			__be16	h_vlan_TCI;
7338		};
7339		/* input: when accompanied with the
7340		 * 'BPF_FIB_LOOKUP_DIRECT | BPF_FIB_LOOKUP_TBID` flags, a
7341		 * specific routing table to use for the fib lookup.
7342		 */
7343		__u32	tbid;
7344	};
7345
7346	union {
7347		/* input */
7348		struct {
7349			__u32	mark;   /* policy routing */
7350			/* 2 4-byte holes for input */
7351		};
7352
7353		/* output: source and dest mac */
7354		struct {
7355			__u8	smac[6];	/* ETH_ALEN */
7356			__u8	dmac[6];	/* ETH_ALEN */
7357		};
7358	};
7359};
7360
7361struct bpf_redir_neigh {
7362	/* network family for lookup (AF_INET, AF_INET6) */
7363	__u32 nh_family;
7364	/* network address of nexthop; skips fib lookup to find gateway */
7365	union {
7366		__be32		ipv4_nh;
7367		__u32		ipv6_nh[4];  /* in6_addr; network order */
7368	};
7369};
7370
7371/* bpf_check_mtu flags*/
7372enum  bpf_check_mtu_flags {
7373	BPF_MTU_CHK_SEGS  = (1U << 0),
7374};
7375
7376enum bpf_check_mtu_ret {
7377	BPF_MTU_CHK_RET_SUCCESS,      /* check and lookup successful */
7378	BPF_MTU_CHK_RET_FRAG_NEEDED,  /* fragmentation required to fwd */
7379	BPF_MTU_CHK_RET_SEGS_TOOBIG,  /* GSO re-segmentation needed to fwd */
7380};
7381
7382enum bpf_task_fd_type {
7383	BPF_FD_TYPE_RAW_TRACEPOINT,	/* tp name */
7384	BPF_FD_TYPE_TRACEPOINT,		/* tp name */
7385	BPF_FD_TYPE_KPROBE,		/* (symbol + offset) or addr */
7386	BPF_FD_TYPE_KRETPROBE,		/* (symbol + offset) or addr */
7387	BPF_FD_TYPE_UPROBE,		/* filename + offset */
7388	BPF_FD_TYPE_URETPROBE,		/* filename + offset */
7389};
7390
7391enum {
7392	BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG		= (1U << 0),
7393	BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL		= (1U << 1),
7394	BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP		= (1U << 2),
7395};
7396
7397struct bpf_flow_keys {
7398	__u16	nhoff;
7399	__u16	thoff;
7400	__u16	addr_proto;			/* ETH_P_* of valid addrs */
7401	__u8	is_frag;
7402	__u8	is_first_frag;
7403	__u8	is_encap;
7404	__u8	ip_proto;
7405	__be16	n_proto;
7406	__be16	sport;
7407	__be16	dport;
7408	union {
7409		struct {
7410			__be32	ipv4_src;
7411			__be32	ipv4_dst;
7412		};
7413		struct {
7414			__u32	ipv6_src[4];	/* in6_addr; network order */
7415			__u32	ipv6_dst[4];	/* in6_addr; network order */
7416		};
7417	};
7418	__u32	flags;
7419	__be32	flow_label;
7420};
7421
7422struct bpf_func_info {
7423	__u32	insn_off;
7424	__u32	type_id;
7425};
7426
7427#define BPF_LINE_INFO_LINE_NUM(line_col)	((line_col) >> 10)
7428#define BPF_LINE_INFO_LINE_COL(line_col)	((line_col) & 0x3ff)
7429
7430struct bpf_line_info {
7431	__u32	insn_off;
7432	__u32	file_name_off;
7433	__u32	line_off;
7434	__u32	line_col;
7435};
7436
7437struct bpf_spin_lock {
7438	__u32	val;
7439};
7440
7441struct bpf_timer {
7442	__u64 __opaque[2];
7443} __attribute__((aligned(8)));
7444
7445struct bpf_task_work {
7446	__u64 __opaque;
7447} __attribute__((aligned(8)));
7448
7449struct bpf_wq {
7450	__u64 __opaque[2];
7451} __attribute__((aligned(8)));
7452
7453struct bpf_dynptr {
7454	__u64 __opaque[2];
7455} __attribute__((aligned(8)));
7456
7457struct bpf_list_head {
7458	__u64 __opaque[2];
7459} __attribute__((aligned(8)));
7460
7461struct bpf_list_node {
7462	__u64 __opaque[3];
7463} __attribute__((aligned(8)));
7464
7465struct bpf_rb_root {
7466	__u64 __opaque[2];
7467} __attribute__((aligned(8)));
7468
7469struct bpf_rb_node {
7470	__u64 __opaque[4];
7471} __attribute__((aligned(8)));
7472
7473struct bpf_refcount {
7474	__u32 __opaque[1];
7475} __attribute__((aligned(4)));
7476
7477struct bpf_sysctl {
7478	__u32	write;		/* Sysctl is being read (= 0) or written (= 1).
7479				 * Allows 1,2,4-byte read, but no write.
7480				 */
7481	__u32	file_pos;	/* Sysctl file position to read from, write to.
7482				 * Allows 1,2,4-byte read an 4-byte write.
7483				 */
7484};
7485
7486struct bpf_sockopt {
7487	__bpf_md_ptr(struct bpf_sock *, sk);
7488	__bpf_md_ptr(void *, optval);
7489	__bpf_md_ptr(void *, optval_end);
7490
7491	__s32	level;
7492	__s32	optname;
7493	__s32	optlen;
7494	__s32	retval;
7495};
7496
7497struct bpf_pidns_info {
7498	__u32 pid;
7499	__u32 tgid;
7500};
7501
7502/* User accessible data for SK_LOOKUP programs. Add new fields at the end. */
7503struct bpf_sk_lookup {
7504	union {
7505		__bpf_md_ptr(struct bpf_sock *, sk); /* Selected socket */
7506		__u64 cookie; /* Non-zero if socket was selected in PROG_TEST_RUN */
7507	};
7508
7509	__u32 family;		/* Protocol family (AF_INET, AF_INET6) */
7510	__u32 protocol;		/* IP protocol (IPPROTO_TCP, IPPROTO_UDP) */
7511	__u32 remote_ip4;	/* Network byte order */
7512	__u32 remote_ip6[4];	/* Network byte order */
7513	__be16 remote_port;	/* Network byte order */
7514	__u16 :16;		/* Zero padding */
7515	__u32 local_ip4;	/* Network byte order */
7516	__u32 local_ip6[4];	/* Network byte order */
7517	__u32 local_port;	/* Host byte order */
7518	__u32 ingress_ifindex;		/* The arriving interface. Determined by inet_iif. */
7519};
7520
7521/*
7522 * struct btf_ptr is used for typed pointer representation; the
7523 * type id is used to render the pointer data as the appropriate type
7524 * via the bpf_snprintf_btf() helper described above.  A flags field -
7525 * potentially to specify additional details about the BTF pointer
7526 * (rather than its mode of display) - is included for future use.
7527 * Display flags - BTF_F_* - are passed to bpf_snprintf_btf separately.
7528 */
7529struct btf_ptr {
7530	void *ptr;
7531	__u32 type_id;
7532	__u32 flags;		/* BTF ptr flags; unused at present. */
7533};
7534
7535/*
7536 * Flags to control bpf_snprintf_btf() behaviour.
7537 *     - BTF_F_COMPACT: no formatting around type information
7538 *     - BTF_F_NONAME: no struct/union member names/types
7539 *     - BTF_F_PTR_RAW: show raw (unobfuscated) pointer values;
7540 *       equivalent to %px.
7541 *     - BTF_F_ZERO: show zero-valued struct/union members; they
7542 *       are not displayed by default
7543 */
7544enum {
7545	BTF_F_COMPACT	=	(1ULL << 0),
7546	BTF_F_NONAME	=	(1ULL << 1),
7547	BTF_F_PTR_RAW	=	(1ULL << 2),
7548	BTF_F_ZERO	=	(1ULL << 3),
7549};
7550
7551/* bpf_core_relo_kind encodes which aspect of captured field/type/enum value
7552 * has to be adjusted by relocations. It is emitted by llvm and passed to
7553 * libbpf and later to the kernel.
7554 */
7555enum bpf_core_relo_kind {
7556	BPF_CORE_FIELD_BYTE_OFFSET = 0,      /* field byte offset */
7557	BPF_CORE_FIELD_BYTE_SIZE = 1,        /* field size in bytes */
7558	BPF_CORE_FIELD_EXISTS = 2,           /* field existence in target kernel */
7559	BPF_CORE_FIELD_SIGNED = 3,           /* field signedness (0 - unsigned, 1 - signed) */
7560	BPF_CORE_FIELD_LSHIFT_U64 = 4,       /* bitfield-specific left bitshift */
7561	BPF_CORE_FIELD_RSHIFT_U64 = 5,       /* bitfield-specific right bitshift */
7562	BPF_CORE_TYPE_ID_LOCAL = 6,          /* type ID in local BPF object */
7563	BPF_CORE_TYPE_ID_TARGET = 7,         /* type ID in target kernel */
7564	BPF_CORE_TYPE_EXISTS = 8,            /* type existence in target kernel */
7565	BPF_CORE_TYPE_SIZE = 9,              /* type size in bytes */
7566	BPF_CORE_ENUMVAL_EXISTS = 10,        /* enum value existence in target kernel */
7567	BPF_CORE_ENUMVAL_VALUE = 11,         /* enum value integer value */
7568	BPF_CORE_TYPE_MATCHES = 12,          /* type match in target kernel */
7569};
7570
7571/*
7572 * "struct bpf_core_relo" is used to pass relocation data form LLVM to libbpf
7573 * and from libbpf to the kernel.
7574 *
7575 * CO-RE relocation captures the following data:
7576 * - insn_off - instruction offset (in bytes) within a BPF program that needs
7577 *   its insn->imm field to be relocated with actual field info;
7578 * - type_id - BTF type ID of the "root" (containing) entity of a relocatable
7579 *   type or field;
7580 * - access_str_off - offset into corresponding .BTF string section. String
7581 *   interpretation depends on specific relocation kind:
7582 *     - for field-based relocations, string encodes an accessed field using
7583 *       a sequence of field and array indices, separated by colon (:). It's
7584 *       conceptually very close to LLVM's getelementptr ([0]) instruction's
7585 *       arguments for identifying offset to a field.
7586 *     - for type-based relocations, strings is expected to be just "0";
7587 *     - for enum value-based relocations, string contains an index of enum
7588 *       value within its enum type;
7589 * - kind - one of enum bpf_core_relo_kind;
7590 *
7591 * Example:
7592 *   struct sample {
7593 *       int a;
7594 *       struct {
7595 *           int b[10];
7596 *       };
7597 *   };
7598 *
7599 *   struct sample *s = ...;
7600 *   int *x = &s->a;     // encoded as "0:0" (a is field #0)
7601 *   int *y = &s->b[5];  // encoded as "0:1:0:5" (anon struct is field #1,
7602 *                       // b is field #0 inside anon struct, accessing elem #5)
7603 *   int *z = &s[10]->b; // encoded as "10:1" (ptr is used as an array)
7604 *
7605 * type_id for all relocs in this example will capture BTF type id of
7606 * `struct sample`.
7607 *
7608 * Such relocation is emitted when using __builtin_preserve_access_index()
7609 * Clang built-in, passing expression that captures field address, e.g.:
7610 *
7611 * bpf_probe_read(&dst, sizeof(dst),
7612 *		  __builtin_preserve_access_index(&src->a.b.c));
7613 *
7614 * In this case Clang will emit field relocation recording necessary data to
7615 * be able to find offset of embedded `a.b.c` field within `src` struct.
7616 *
7617 * [0] https://llvm.org/docs/LangRef.html#getelementptr-instruction
7618 */
7619struct bpf_core_relo {
7620	__u32 insn_off;
7621	__u32 type_id;
7622	__u32 access_str_off;
7623	enum bpf_core_relo_kind kind;
7624};
7625
7626/*
7627 * Flags to control bpf_timer_start() behaviour.
7628 *     - BPF_F_TIMER_ABS: Timeout passed is absolute time, by default it is
7629 *       relative to current time.
7630 *     - BPF_F_TIMER_CPU_PIN: Timer will be pinned to the CPU of the caller.
7631 */
7632enum {
7633	BPF_F_TIMER_ABS = (1ULL << 0),
7634	BPF_F_TIMER_CPU_PIN = (1ULL << 1),
7635};
7636
7637/* BPF numbers iterator state */
7638struct bpf_iter_num {
7639	/* opaque iterator state; having __u64 here allows to preserve correct
7640	 * alignment requirements in vmlinux.h, generated from BTF
7641	 */
7642	__u64 __opaque[1];
7643} __attribute__((aligned(8)));
7644
7645/*
7646 * Flags to control BPF kfunc behaviour.
7647 *     - BPF_F_PAD_ZEROS: Pad destination buffer with zeros. (See the respective
7648 *       helper documentation for details.)
7649 */
7650enum bpf_kfunc_flags {
7651	BPF_F_PAD_ZEROS = (1ULL << 0),
7652};
7653
7654/*
7655 * Values of a BPF_MAP_TYPE_INSN_ARRAY entry must be of this type.
7656 *
7657 * Before the map is used the orig_off field should point to an
7658 * instruction inside the program being loaded. The other fields
7659 * must be set to 0.
7660 *
7661 * After the program is loaded, the xlated_off will be adjusted
7662 * by the verifier to point to the index of the original instruction
7663 * in the xlated program. If the instruction is deleted, it will
7664 * be set to (u32)-1. The jitted_off will be set to the corresponding
7665 * offset in the jitted image of the program.
7666 */
7667struct bpf_insn_array_value {
7668	__u32 orig_off;
7669	__u32 xlated_off;
7670	__u32 jitted_off;
7671	__u32 :32;
7672};
7673
7674#endif /* _UAPI__LINUX_BPF_H__ */