protocol.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/* Multipath TCP
   3 *
   4 * Copyright (c) 2017 - 2019, Intel Corporation.
   5 */
   6
   7#ifndef __MPTCP_PROTOCOL_H
   8#define __MPTCP_PROTOCOL_H
   9
  10#include <linux/random.h>
  11#include <net/tcp.h>
  12#include <net/inet_connection_sock.h>
  13#include <uapi/linux/mptcp.h>
  14#include <net/genetlink.h>
  15#include <net/rstreason.h>
  16
  17#define MPTCP_SUPPORTED_VERSION	1
  18
  19/* MPTCP option bits */
  20#define OPTION_MPTCP_MPC_SYN	BIT(0)
  21#define OPTION_MPTCP_MPC_SYNACK	BIT(1)
  22#define OPTION_MPTCP_MPC_ACK	BIT(2)
  23#define OPTION_MPTCP_MPJ_SYN	BIT(3)
  24#define OPTION_MPTCP_MPJ_SYNACK	BIT(4)
  25#define OPTION_MPTCP_MPJ_ACK	BIT(5)
  26#define OPTION_MPTCP_ADD_ADDR	BIT(6)
  27#define OPTION_MPTCP_RM_ADDR	BIT(7)
  28#define OPTION_MPTCP_FASTCLOSE	BIT(8)
  29#define OPTION_MPTCP_PRIO	BIT(9)
  30#define OPTION_MPTCP_RST	BIT(10)
  31#define OPTION_MPTCP_DSS	BIT(11)
  32#define OPTION_MPTCP_FAIL	BIT(12)
  33
  34#define OPTION_MPTCP_CSUMREQD	BIT(13)
  35
  36#define OPTIONS_MPTCP_MPC	(OPTION_MPTCP_MPC_SYN | OPTION_MPTCP_MPC_SYNACK | \
  37				 OPTION_MPTCP_MPC_ACK)
  38#define OPTIONS_MPTCP_MPJ	(OPTION_MPTCP_MPJ_SYN | OPTION_MPTCP_MPJ_SYNACK | \
  39				 OPTION_MPTCP_MPJ_ACK)
  40
  41/* MPTCP option subtypes */
  42#define MPTCPOPT_MP_CAPABLE	0
  43#define MPTCPOPT_MP_JOIN	1
  44#define MPTCPOPT_DSS		2
  45#define MPTCPOPT_ADD_ADDR	3
  46#define MPTCPOPT_RM_ADDR	4
  47#define MPTCPOPT_MP_PRIO	5
  48#define MPTCPOPT_MP_FAIL	6
  49#define MPTCPOPT_MP_FASTCLOSE	7
  50#define MPTCPOPT_RST		8
  51
  52/* MPTCP suboption lengths */
  53#define TCPOLEN_MPTCP_MPC_SYN		4
  54#define TCPOLEN_MPTCP_MPC_SYNACK	12
  55#define TCPOLEN_MPTCP_MPC_ACK		20
  56#define TCPOLEN_MPTCP_MPC_ACK_DATA	22
  57#define TCPOLEN_MPTCP_MPJ_SYN		12
  58#define TCPOLEN_MPTCP_MPJ_SYNACK	16
  59#define TCPOLEN_MPTCP_MPJ_ACK		24
  60#define TCPOLEN_MPTCP_DSS_BASE		4
  61#define TCPOLEN_MPTCP_DSS_ACK32		4
  62#define TCPOLEN_MPTCP_DSS_ACK64		8
  63#define TCPOLEN_MPTCP_DSS_MAP32		10
  64#define TCPOLEN_MPTCP_DSS_MAP64		14
  65#define TCPOLEN_MPTCP_DSS_CHECKSUM	2
  66#define TCPOLEN_MPTCP_ADD_ADDR		16
  67#define TCPOLEN_MPTCP_ADD_ADDR_PORT	18
  68#define TCPOLEN_MPTCP_ADD_ADDR_BASE	8
  69#define TCPOLEN_MPTCP_ADD_ADDR_BASE_PORT	10
  70#define TCPOLEN_MPTCP_ADD_ADDR6		28
  71#define TCPOLEN_MPTCP_ADD_ADDR6_PORT	30
  72#define TCPOLEN_MPTCP_ADD_ADDR6_BASE	20
  73#define TCPOLEN_MPTCP_ADD_ADDR6_BASE_PORT	22
  74#define TCPOLEN_MPTCP_PORT_LEN		2
  75#define TCPOLEN_MPTCP_PORT_ALIGN	2
  76#define TCPOLEN_MPTCP_RM_ADDR_BASE	3
  77#define TCPOLEN_MPTCP_PRIO		3
  78#define TCPOLEN_MPTCP_PRIO_ALIGN	4
  79#define TCPOLEN_MPTCP_FASTCLOSE		12
  80#define TCPOLEN_MPTCP_RST		4
  81#define TCPOLEN_MPTCP_FAIL		12
  82
  83#define TCPOLEN_MPTCP_MPC_ACK_DATA_CSUM	(TCPOLEN_MPTCP_DSS_CHECKSUM + TCPOLEN_MPTCP_MPC_ACK_DATA)
  84
  85/* MPTCP MP_JOIN flags */
  86#define MPTCPOPT_BACKUP		BIT(0)
  87#define MPTCPOPT_THMAC_LEN	8
  88
  89/* MPTCP MP_CAPABLE flags */
  90#define MPTCP_VERSION_MASK	(0x0F)
  91#define MPTCP_CAP_CHECKSUM_REQD	BIT(7)
  92#define MPTCP_CAP_EXTENSIBILITY	BIT(6)
  93#define MPTCP_CAP_DENY_JOIN_ID0	BIT(5)
  94#define MPTCP_CAP_HMAC_SHA256	BIT(0)
  95#define MPTCP_CAP_FLAG_MASK	(0x1F)
  96
  97/* MPTCP DSS flags */
  98#define MPTCP_DSS_DATA_FIN	BIT(4)
  99#define MPTCP_DSS_DSN64		BIT(3)
 100#define MPTCP_DSS_HAS_MAP	BIT(2)
 101#define MPTCP_DSS_ACK64		BIT(1)
 102#define MPTCP_DSS_HAS_ACK	BIT(0)
 103#define MPTCP_DSS_FLAG_MASK	(0x1F)
 104
 105/* MPTCP ADD_ADDR flags */
 106#define MPTCP_ADDR_ECHO		BIT(0)
 107
 108/* MPTCP MP_PRIO flags */
 109#define MPTCP_PRIO_BKUP		BIT(0)
 110
 111/* MPTCP TCPRST flags */
 112#define MPTCP_RST_TRANSIENT	BIT(0)
 113
 114/* MPTCP socket atomic flags */
 115#define MPTCP_WORK_RTX		1
 116#define MPTCP_FALLBACK_DONE	2
 117#define MPTCP_WORK_CLOSE_SUBFLOW 3
 118
 119/* MPTCP socket release cb flags */
 120#define MPTCP_PUSH_PENDING	1
 121#define MPTCP_CLEAN_UNA		2
 122#define MPTCP_ERROR_REPORT	3
 123#define MPTCP_RETRANSMIT	4
 124#define MPTCP_FLUSH_JOIN_LIST	5
 125#define MPTCP_SYNC_STATE	6
 126#define MPTCP_SYNC_SNDBUF	7
 127
 128struct mptcp_skb_cb {
 129	u64 map_seq;
 130	u64 end_seq;
 131	u32 offset;
 132	u8  has_rxtstamp;
 133	u8  cant_coalesce;
 134};
 135
 136#define MPTCP_SKB_CB(__skb)	((struct mptcp_skb_cb *)&((__skb)->cb[0]))
 137
 138static inline bool before64(__u64 seq1, __u64 seq2)
 139{
 140	return (__s64)(seq1 - seq2) < 0;
 141}
 142
 143#define after64(seq2, seq1)	before64(seq1, seq2)
 144
 145struct mptcp_options_received {
 146	u64	sndr_key;
 147	u64	rcvr_key;
 148	u64	data_ack;
 149	u64	data_seq;
 150	u32	subflow_seq;
 151	u16	data_len;
 152	__sum16	csum;
 153	struct_group(status,
 154		u16 suboptions;
 155		u16 use_map:1,
 156		    dsn64:1,
 157		    data_fin:1,
 158		    use_ack:1,
 159		    ack64:1,
 160		    mpc_map:1,
 161		    reset_reason:4,
 162		    reset_transient:1,
 163		    echo:1,
 164		    backup:1,
 165		    deny_join_id0:1,
 166		    __unused:2;
 167	);
 168	u8	join_id;
 169	u32	token;
 170	u32	nonce;
 171	u64	thmac;
 172	u8	hmac[MPTCPOPT_HMAC_LEN];
 173	struct mptcp_addr_info addr;
 174	struct mptcp_rm_list rm_list;
 175	u64	ahmac;
 176	u64	fail_seq;
 177};
 178
 179static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field)
 180{
 181	return htonl((TCPOPT_MPTCP << 24) | (len << 16) | (subopt << 12) |
 182		     ((nib & 0xF) << 8) | field);
 183}
 184
 185enum mptcp_pm_status {
 186	MPTCP_PM_ADD_ADDR_RECEIVED,
 187	MPTCP_PM_ADD_ADDR_SEND_ACK,
 188	MPTCP_PM_RM_ADDR_RECEIVED,
 189	MPTCP_PM_ESTABLISHED,
 190	MPTCP_PM_SUBFLOW_ESTABLISHED,
 191	MPTCP_PM_ALREADY_ESTABLISHED,	/* persistent status, set after ESTABLISHED event */
 192	MPTCP_PM_MPC_ENDPOINT_ACCOUNTED /* persistent status, set after MPC local address is
 193					 * accounted int id_avail_bitmap
 194					 */
 195};
 196
 197enum mptcp_pm_type {
 198	MPTCP_PM_TYPE_KERNEL = 0,
 199	MPTCP_PM_TYPE_USERSPACE,
 200
 201	__MPTCP_PM_TYPE_NR,
 202	__MPTCP_PM_TYPE_MAX = __MPTCP_PM_TYPE_NR - 1,
 203};
 204
 205/* Status bits below MPTCP_PM_ALREADY_ESTABLISHED need pm worker actions */
 206#define MPTCP_PM_WORK_MASK ((1 << MPTCP_PM_ALREADY_ESTABLISHED) - 1)
 207
 208enum mptcp_addr_signal_status {
 209	MPTCP_ADD_ADDR_SIGNAL,
 210	MPTCP_ADD_ADDR_ECHO,
 211	MPTCP_RM_ADDR_SIGNAL,
 212};
 213
 214/* max value of mptcp_addr_info.id */
 215#define MPTCP_PM_MAX_ADDR_ID		U8_MAX
 216
 217struct mptcp_pm_data {
 218	struct mptcp_addr_info local;
 219	struct mptcp_addr_info remote;
 220	struct list_head anno_list;
 221	struct list_head userspace_pm_local_addr_list;
 222
 223	spinlock_t	lock;		/*protects the whole PM data */
 224
 225	struct_group(reset,
 226
 227	u8		addr_signal;
 228	bool		server_side;
 229	bool		work_pending;
 230	bool		accept_addr;
 231	bool		accept_subflow;
 232	bool		remote_deny_join_id0;
 233	u8		add_addr_signaled;
 234	u8		add_addr_accepted;
 235	u8		local_addr_used;
 236	u8		pm_type;
 237	u8		extra_subflows;
 238	u8		status;
 239
 240	);
 241
 242	DECLARE_BITMAP(id_avail_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
 243	struct mptcp_rm_list rm_list_tx;
 244	struct mptcp_rm_list rm_list_rx;
 245};
 246
 247struct mptcp_pm_local {
 248	struct mptcp_addr_info	addr;
 249	u8			flags;
 250	int			ifindex;
 251};
 252
 253struct mptcp_pm_addr_entry {
 254	struct list_head	list;
 255	struct mptcp_addr_info	addr;
 256	u8			flags;
 257	int			ifindex;
 258	struct socket		*lsk;
 259};
 260
 261struct mptcp_data_frag {
 262	struct list_head list;
 263	u64 data_seq;
 264	u16 data_len;
 265	u16 offset;
 266	u16 overhead;
 267	u16 already_sent;
 268	struct page *page;
 269};
 270
 271/* MPTCP connection sock */
 272struct mptcp_sock {
 273	/* inet_connection_sock must be the first member */
 274	struct inet_connection_sock sk;
 275	u64		local_key;		/* protected by the first subflow socket lock
 276						 * lockless access read
 277						 */
 278	u64		remote_key;		/* same as above */
 279	u64		write_seq;
 280	u64		bytes_sent;
 281	u64		snd_nxt;
 282	u64		bytes_received;
 283	u64		ack_seq;
 284	atomic64_t	rcv_wnd_sent;
 285	u64		rcv_data_fin_seq;
 286	u64		bytes_retrans;
 287	u64		bytes_consumed;
 288	int		snd_burst;
 289	int		old_wspace;
 290	u64		recovery_snd_nxt;	/* in recovery mode accept up to this seq;
 291						 * recovery related fields are under data_lock
 292						 * protection
 293						 */
 294	u64		bytes_acked;
 295	u64		snd_una;
 296	u64		wnd_end;
 297	u32		last_data_sent;
 298	u32		last_data_recv;
 299	u32		last_ack_recv;
 300	unsigned long	timer_ival;
 301	u32		token;
 302	unsigned long	flags;
 303	unsigned long	cb_flags;
 304	bool		recovery;		/* closing subflow write queue reinjected */
 305	bool		can_ack;
 306	bool		fully_established;
 307	bool		rcv_data_fin;
 308	bool		snd_data_fin_enable;
 309	bool		rcv_fastclose;
 310	bool		use_64bit_ack; /* Set when we received a 64-bit DSN */
 311	bool		csum_enabled;
 312	bool		allow_infinite_fallback;
 313	u8		pending_state; /* A subflow asked to set this sk_state,
 314					* protected by the msk data lock
 315					*/
 316	u8		mpc_endpoint_id;
 317	u8		recvmsg_inq:1,
 318			cork:1,
 319			nodelay:1,
 320			fastopening:1,
 321			in_accept_queue:1,
 322			free_first:1,
 323			rcvspace_init:1,
 324			fastclosing:1;
 325	u32		notsent_lowat;
 326	int		keepalive_cnt;
 327	int		keepalive_idle;
 328	int		keepalive_intvl;
 329	int		maxseg;
 330	struct work_struct work;
 331	struct sk_buff  *ooo_last_skb;
 332	struct rb_root  out_of_order_queue;
 333	struct list_head conn_list;
 334	struct list_head rtx_queue;
 335	struct mptcp_data_frag *first_pending;
 336	struct list_head join_list;
 337	struct sock	*first; /* The mptcp ops can safely dereference, using suitable
 338				 * ONCE annotation, the subflow outside the socket
 339				 * lock as such sock is freed after close().
 340				 */
 341	struct mptcp_pm_data	pm;
 342	struct mptcp_sched_ops	*sched;
 343	struct {
 344		int	space;	/* bytes copied in last measurement window */
 345		int	copied; /* bytes copied in this measurement window */
 346		u64	time;	/* start time of measurement window */
 347		u64	rtt_us; /* last maximum rtt of subflows */
 348	} rcvq_space;
 349	u8		scaling_ratio;
 350	bool		allow_subflows;
 351
 352	u32		subflow_id;
 353	u32		setsockopt_seq;
 354	char		ca_name[TCP_CA_NAME_MAX];
 355
 356	spinlock_t	fallback_lock;	/* protects fallback,
 357					 * allow_infinite_fallback and
 358					 * allow_join
 359					 */
 360
 361	struct list_head backlog_list;	/* protected by the data lock */
 362	u32		backlog_len;
 363	u32		backlog_unaccounted;
 364};
 365
 366#define mptcp_data_lock(sk) spin_lock_bh(&(sk)->sk_lock.slock)
 367#define mptcp_data_unlock(sk) spin_unlock_bh(&(sk)->sk_lock.slock)
 368
 369#define mptcp_for_each_subflow(__msk, __subflow)			\
 370	list_for_each_entry(__subflow, &((__msk)->conn_list), node)
 371#define mptcp_for_each_subflow_safe(__msk, __subflow, __tmp)			\
 372	list_for_each_entry_safe(__subflow, __tmp, &((__msk)->conn_list), node)
 373#define mptcp_next_subflow(__msk, __subflow)				\
 374	list_next_entry_circular(__subflow, &((__msk)->conn_list), node)
 375
 376extern struct genl_family mptcp_genl_family;
 377
 378static inline void msk_owned_by_me(const struct mptcp_sock *msk)
 379{
 380	sock_owned_by_me((const struct sock *)msk);
 381}
 382
 383#ifdef CONFIG_DEBUG_NET
 384/* MPTCP-specific: we might (indirectly) call this helper with the wrong sk */
 385#undef tcp_sk
 386#define tcp_sk(ptr) ({								\
 387	typeof(ptr) _ptr = (ptr);						\
 388	WARN_ON(_ptr->sk_protocol != IPPROTO_TCP);				\
 389	container_of_const(_ptr, struct tcp_sock, inet_conn.icsk_inet.sk);	\
 390})
 391#define mptcp_sk(ptr) ({						\
 392	typeof(ptr) _ptr = (ptr);					\
 393	WARN_ON(_ptr->sk_protocol != IPPROTO_MPTCP);			\
 394	container_of_const(_ptr, struct mptcp_sock, sk.icsk_inet.sk);	\
 395})
 396
 397#else /* !CONFIG_DEBUG_NET */
 398#define mptcp_sk(ptr) container_of_const(ptr, struct mptcp_sock, sk.icsk_inet.sk)
 399#endif
 400
 401static inline int mptcp_win_from_space(const struct sock *sk, int space)
 402{
 403	return __tcp_win_from_space(mptcp_sk(sk)->scaling_ratio, space);
 404}
 405
 406static inline int mptcp_space_from_win(const struct sock *sk, int win)
 407{
 408	return __tcp_space_from_win(mptcp_sk(sk)->scaling_ratio, win);
 409}
 410
 411static inline int __mptcp_space(const struct sock *sk)
 412{
 413	return mptcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf) -
 414				    READ_ONCE(mptcp_sk(sk)->backlog_len) -
 415				    sk_rmem_alloc_get(sk));
 416}
 417
 418static inline struct mptcp_data_frag *mptcp_send_head(const struct sock *sk)
 419{
 420	const struct mptcp_sock *msk = mptcp_sk(sk);
 421
 422	return msk->first_pending;
 423}
 424
 425static inline struct mptcp_data_frag *mptcp_send_next(struct sock *sk)
 426{
 427	struct mptcp_sock *msk = mptcp_sk(sk);
 428	struct mptcp_data_frag *cur;
 429
 430	cur = msk->first_pending;
 431	return list_is_last(&cur->list, &msk->rtx_queue) ? NULL :
 432						     list_next_entry(cur, list);
 433}
 434
 435static inline struct mptcp_data_frag *mptcp_pending_tail(const struct sock *sk)
 436{
 437	const struct mptcp_sock *msk = mptcp_sk(sk);
 438
 439	if (!msk->first_pending)
 440		return NULL;
 441
 442	if (WARN_ON_ONCE(list_empty(&msk->rtx_queue)))
 443		return NULL;
 444
 445	return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
 446}
 447
 448static inline struct mptcp_data_frag *mptcp_rtx_head(struct sock *sk)
 449{
 450	struct mptcp_sock *msk = mptcp_sk(sk);
 451
 452	if (msk->snd_una == msk->snd_nxt)
 453		return NULL;
 454
 455	return list_first_entry_or_null(&msk->rtx_queue, struct mptcp_data_frag, list);
 456}
 457
 458struct csum_pseudo_header {
 459	__be64 data_seq;
 460	__be32 subflow_seq;
 461	__be16 data_len;
 462	__sum16 csum;
 463};
 464
 465struct mptcp_subflow_request_sock {
 466	struct	tcp_request_sock sk;
 467	u16	mp_capable : 1,
 468		mp_join : 1,
 469		backup : 1,
 470		request_bkup : 1,
 471		csum_reqd : 1,
 472		allow_join_id0 : 1;
 473	u8	local_id;
 474	u8	remote_id;
 475	u64	local_key;
 476	u64	idsn;
 477	u32	token;
 478	u32	ssn_offset;
 479	u64	thmac;
 480	u32	local_nonce;
 481	u32	remote_nonce;
 482	struct mptcp_sock	*msk;
 483	struct hlist_nulls_node token_node;
 484};
 485
 486static inline struct mptcp_subflow_request_sock *
 487mptcp_subflow_rsk(const struct request_sock *rsk)
 488{
 489	return (struct mptcp_subflow_request_sock *)rsk;
 490}
 491
 492struct mptcp_delegated_action {
 493	struct napi_struct napi;
 494	local_lock_t bh_lock;
 495	struct list_head head;
 496};
 497
 498DECLARE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions);
 499
 500#define MPTCP_DELEGATE_SCHEDULED	0
 501#define MPTCP_DELEGATE_SEND		1
 502#define MPTCP_DELEGATE_ACK		2
 503#define MPTCP_DELEGATE_SNDBUF		3
 504
 505#define MPTCP_DELEGATE_ACTIONS_MASK	(~BIT(MPTCP_DELEGATE_SCHEDULED))
 506/* MPTCP subflow context */
 507struct mptcp_subflow_context {
 508	struct	list_head node;/* conn_list of subflows */
 509
 510	struct_group(reset,
 511
 512	unsigned long avg_pacing_rate; /* protected by msk socket lock */
 513	u64	local_key;
 514	u64	remote_key;
 515	u64	idsn;
 516	u64	map_seq;
 517	u64	rcv_wnd_sent;
 518	u32	snd_isn;
 519	u32	token;
 520	u32	rel_write_seq;
 521	u32	map_subflow_seq;
 522	u32	ssn_offset;
 523	u32	map_data_len;
 524	__wsum	map_data_csum;
 525	u32	map_csum_len;
 526	u32	request_mptcp : 1,  /* send MP_CAPABLE */
 527		request_join : 1,   /* send MP_JOIN */
 528		request_bkup : 1,
 529		mp_capable : 1,	    /* remote is MPTCP capable */
 530		mp_join : 1,	    /* remote is JOINing */
 531		pm_notified : 1,    /* PM hook called for established status */
 532		conn_finished : 1,
 533		map_valid : 1,
 534		map_csum_reqd : 1,
 535		map_data_fin : 1,
 536		mpc_map : 1,
 537		backup : 1,
 538		send_mp_prio : 1,
 539		send_mp_fail : 1,
 540		send_fastclose : 1,
 541		send_infinite_map : 1,
 542		remote_key_valid : 1,        /* received the peer key from */
 543		disposable : 1,	    /* ctx can be free at ulp release time */
 544		closing : 1,	    /* must not pass rx data to msk anymore */
 545		stale : 1,	    /* unable to snd/rcv data, do not use for xmit */
 546		valid_csum_seen : 1,        /* at least one csum validated */
 547		is_mptfo : 1,	    /* subflow is doing TFO */
 548		close_event_done : 1,       /* has done the post-closed part */
 549		mpc_drop : 1,	    /* the MPC option has been dropped in a rtx */
 550		__unused : 8;
 551	bool	data_avail;
 552	bool	scheduled;
 553	bool	pm_listener;	    /* a listener managed by the kernel PM? */
 554	bool	fully_established;  /* path validated */
 555	u32	lent_mem_frag;
 556	u32	remote_nonce;
 557	u64	thmac;
 558	u32	local_nonce;
 559	u32	remote_token;
 560	union {
 561		u8	hmac[MPTCPOPT_HMAC_LEN]; /* MPJ subflow only */
 562		u64	iasn;	    /* initial ack sequence number, MPC subflows only */
 563	};
 564	s16	local_id;	    /* if negative not initialized yet */
 565	u8	remote_id;
 566	u8	reset_seen:1;
 567	u8	reset_transient:1;
 568	u8	reset_reason:4;
 569	u8	stale_count;
 570
 571	u32	subflow_id;
 572
 573	long	delegated_status;
 574	unsigned long	fail_tout;
 575
 576	);
 577
 578	struct	list_head delegated_node;   /* link into delegated_action, protected by local BH */
 579
 580	u32	setsockopt_seq;
 581	u32	stale_rcv_tstamp;
 582	int     cached_sndbuf;	    /* sndbuf size when last synced with the msk sndbuf,
 583				     * protected by the msk socket lock
 584				     */
 585
 586	struct	sock *tcp_sock;	    /* tcp sk backpointer */
 587	struct	sock *conn;	    /* parent mptcp_sock */
 588	const	struct inet_connection_sock_af_ops *icsk_af_ops;
 589	void	(*tcp_state_change)(struct sock *sk);
 590	void	(*tcp_error_report)(struct sock *sk);
 591
 592	struct	rcu_head rcu;
 593};
 594
 595static inline struct mptcp_subflow_context *
 596mptcp_subflow_ctx(const struct sock *sk)
 597{
 598	const struct inet_connection_sock *icsk = inet_csk(sk);
 599
 600	/* Use RCU on icsk_ulp_data only for sock diag code */
 601	return (__force struct mptcp_subflow_context *)icsk->icsk_ulp_data;
 602}
 603
 604static inline struct sock *
 605mptcp_subflow_tcp_sock(const struct mptcp_subflow_context *subflow)
 606{
 607	return subflow->tcp_sock;
 608}
 609
 610static inline void
 611mptcp_subflow_ctx_reset(struct mptcp_subflow_context *subflow)
 612{
 613	memset(&subflow->reset, 0, sizeof(subflow->reset));
 614	subflow->request_mptcp = 1;
 615	WRITE_ONCE(subflow->local_id, -1);
 616}
 617
 618/* Convert reset reasons in MPTCP to enum sk_rst_reason type */
 619static inline enum sk_rst_reason
 620sk_rst_convert_mptcp_reason(u32 reason)
 621{
 622	switch (reason) {
 623	case MPTCP_RST_EUNSPEC:
 624		return SK_RST_REASON_MPTCP_RST_EUNSPEC;
 625	case MPTCP_RST_EMPTCP:
 626		return SK_RST_REASON_MPTCP_RST_EMPTCP;
 627	case MPTCP_RST_ERESOURCE:
 628		return SK_RST_REASON_MPTCP_RST_ERESOURCE;
 629	case MPTCP_RST_EPROHIBIT:
 630		return SK_RST_REASON_MPTCP_RST_EPROHIBIT;
 631	case MPTCP_RST_EWQ2BIG:
 632		return SK_RST_REASON_MPTCP_RST_EWQ2BIG;
 633	case MPTCP_RST_EBADPERF:
 634		return SK_RST_REASON_MPTCP_RST_EBADPERF;
 635	case MPTCP_RST_EMIDDLEBOX:
 636		return SK_RST_REASON_MPTCP_RST_EMIDDLEBOX;
 637	default:
 638		/* It should not happen, or else errors may occur
 639		 * in MPTCP layer
 640		 */
 641		return SK_RST_REASON_ERROR;
 642	}
 643}
 644
 645static inline void
 646mptcp_send_active_reset_reason(struct sock *sk)
 647{
 648	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
 649	enum sk_rst_reason reason;
 650
 651	reason = sk_rst_convert_mptcp_reason(subflow->reset_reason);
 652	tcp_send_active_reset(sk, GFP_ATOMIC, reason);
 653}
 654
 655/* Made the fwd mem carried by the given skb available to the msk,
 656 * To be paired with a previous mptcp_subflow_lend_fwdmem() before freeing
 657 * the skb or setting the skb ownership.
 658 */
 659static inline void mptcp_borrow_fwdmem(struct sock *sk, struct sk_buff *skb)
 660{
 661	struct sock *ssk = skb->sk;
 662
 663	/* The subflow just lend the skb fwd memory; if the subflow meanwhile
 664	 * closed, mptcp_close_ssk() already released the ssk rcv memory.
 665	 */
 666	DEBUG_NET_WARN_ON_ONCE(skb->destructor);
 667	sk_forward_alloc_add(sk, skb->truesize);
 668	if (!ssk)
 669		return;
 670
 671	atomic_sub(skb->truesize, &ssk->sk_rmem_alloc);
 672	skb->sk = NULL;
 673}
 674
 675static inline void
 676__mptcp_subflow_lend_fwdmem(struct mptcp_subflow_context *subflow, int size)
 677{
 678	int frag = (subflow->lent_mem_frag + size) & (PAGE_SIZE - 1);
 679
 680	subflow->lent_mem_frag = frag;
 681}
 682
 683static inline void
 684mptcp_subflow_lend_fwdmem(struct mptcp_subflow_context *subflow,
 685			  struct sk_buff *skb)
 686{
 687	__mptcp_subflow_lend_fwdmem(subflow, skb->truesize);
 688	skb->destructor = NULL;
 689}
 690
 691static inline u64
 692mptcp_subflow_get_map_offset(const struct mptcp_subflow_context *subflow)
 693{
 694	return tcp_sk(mptcp_subflow_tcp_sock(subflow))->copied_seq -
 695		      subflow->ssn_offset -
 696		      subflow->map_subflow_seq;
 697}
 698
 699static inline u64
 700mptcp_subflow_get_mapped_dsn(const struct mptcp_subflow_context *subflow)
 701{
 702	return subflow->map_seq + mptcp_subflow_get_map_offset(subflow);
 703}
 704
 705void mptcp_subflow_process_delegated(struct sock *ssk, long actions);
 706
 707static inline void mptcp_subflow_delegate(struct mptcp_subflow_context *subflow, int action)
 708{
 709	long old, set_bits = BIT(MPTCP_DELEGATE_SCHEDULED) | BIT(action);
 710	struct mptcp_delegated_action *delegated;
 711	bool schedule;
 712
 713	/* the caller held the subflow bh socket lock */
 714	lockdep_assert_in_softirq();
 715
 716	/* The implied barrier pairs with tcp_release_cb_override()
 717	 * mptcp_napi_poll(), and ensures the below list check sees list
 718	 * updates done prior to delegated status bits changes
 719	 */
 720	old = set_mask_bits(&subflow->delegated_status, 0, set_bits);
 721	if (!(old & BIT(MPTCP_DELEGATE_SCHEDULED))) {
 722		if (WARN_ON_ONCE(!list_empty(&subflow->delegated_node)))
 723			return;
 724
 725		local_lock_nested_bh(&mptcp_delegated_actions.bh_lock);
 726		delegated = this_cpu_ptr(&mptcp_delegated_actions);
 727		schedule = list_empty(&delegated->head);
 728		list_add_tail(&subflow->delegated_node, &delegated->head);
 729		local_unlock_nested_bh(&mptcp_delegated_actions.bh_lock);
 730		sock_hold(mptcp_subflow_tcp_sock(subflow));
 731		if (schedule)
 732			napi_schedule(&delegated->napi);
 733	}
 734}
 735
 736static inline struct mptcp_subflow_context *
 737mptcp_subflow_delegated_next(struct mptcp_delegated_action *delegated)
 738{
 739	struct mptcp_subflow_context *ret;
 740
 741	local_lock_nested_bh(&mptcp_delegated_actions.bh_lock);
 742	if (list_empty(&delegated->head)) {
 743		local_unlock_nested_bh(&mptcp_delegated_actions.bh_lock);
 744		return NULL;
 745	}
 746
 747	ret = list_first_entry(&delegated->head, struct mptcp_subflow_context, delegated_node);
 748	list_del_init(&ret->delegated_node);
 749	local_unlock_nested_bh(&mptcp_delegated_actions.bh_lock);
 750	return ret;
 751}
 752
 753void __mptcp_inherit_memcg(struct sock *sk, struct sock *ssk, gfp_t gfp);
 754void __mptcp_inherit_cgrp_data(struct sock *sk, struct sock *ssk);
 755
 756int mptcp_is_enabled(const struct net *net);
 757unsigned int mptcp_get_add_addr_timeout(const struct net *net);
 758int mptcp_is_checksum_enabled(const struct net *net);
 759int mptcp_allow_join_id0(const struct net *net);
 760unsigned int mptcp_stale_loss_cnt(const struct net *net);
 761unsigned int mptcp_close_timeout(const struct sock *sk);
 762int mptcp_get_pm_type(const struct net *net);
 763const char *mptcp_get_path_manager(const struct net *net);
 764const char *mptcp_get_scheduler(const struct net *net);
 765
 766void mptcp_active_disable(struct sock *sk);
 767bool mptcp_active_should_disable(struct sock *ssk);
 768void mptcp_active_enable(struct sock *sk);
 769
 770void mptcp_get_available_schedulers(char *buf, size_t maxlen);
 771void __mptcp_subflow_fully_established(struct mptcp_sock *msk,
 772				       struct mptcp_subflow_context *subflow,
 773				       const struct mptcp_options_received *mp_opt);
 774bool __mptcp_retransmit_pending_data(struct sock *sk);
 775void mptcp_check_and_set_pending(struct sock *sk);
 776void __mptcp_push_pending(struct sock *sk, unsigned int flags);
 777bool mptcp_subflow_data_available(struct sock *sk);
 778void __init mptcp_subflow_init(void);
 779void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how);
 780void mptcp_close_ssk(struct sock *sk, struct sock *ssk,
 781		     struct mptcp_subflow_context *subflow);
 782void __mptcp_subflow_send_ack(struct sock *ssk);
 783void mptcp_subflow_reset(struct sock *ssk);
 784void mptcp_subflow_queue_clean(struct sock *sk, struct sock *ssk);
 785void mptcp_sock_graft(struct sock *sk, struct socket *parent);
 786struct sock *__mptcp_nmpc_sk(struct mptcp_sock *msk);
 787bool __mptcp_close(struct sock *sk, long timeout);
 788void mptcp_cancel_work(struct sock *sk);
 789void __mptcp_unaccepted_force_close(struct sock *sk);
 790void mptcp_set_state(struct sock *sk, int state);
 791
 792bool mptcp_addresses_equal(const struct mptcp_addr_info *a,
 793			   const struct mptcp_addr_info *b, bool use_port);
 794void mptcp_local_address(const struct sock_common *skc,
 795			 struct mptcp_addr_info *addr);
 796void mptcp_remote_address(const struct sock_common *skc,
 797			  struct mptcp_addr_info *addr);
 798
 799/* called with sk socket lock held */
 800int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_pm_local *local,
 801			    const struct mptcp_addr_info *remote);
 802int mptcp_subflow_create_socket(struct sock *sk, unsigned short family,
 803				struct socket **new_sock);
 804void mptcp_info2sockaddr(const struct mptcp_addr_info *info,
 805			 struct sockaddr_storage *addr,
 806			 unsigned short family);
 807struct mptcp_sched_ops *mptcp_sched_find(const char *name);
 808int mptcp_validate_scheduler(struct mptcp_sched_ops *sched);
 809int mptcp_register_scheduler(struct mptcp_sched_ops *sched);
 810void mptcp_unregister_scheduler(struct mptcp_sched_ops *sched);
 811void mptcp_sched_init(void);
 812int mptcp_init_sched(struct mptcp_sock *msk,
 813		     struct mptcp_sched_ops *sched);
 814void mptcp_release_sched(struct mptcp_sock *msk);
 815void mptcp_subflow_set_scheduled(struct mptcp_subflow_context *subflow,
 816				 bool scheduled);
 817struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk);
 818struct sock *mptcp_subflow_get_retrans(struct mptcp_sock *msk);
 819int mptcp_sched_get_send(struct mptcp_sock *msk);
 820int mptcp_sched_get_retrans(struct mptcp_sock *msk);
 821
 822static inline u64 mptcp_data_avail(const struct mptcp_sock *msk)
 823{
 824	return READ_ONCE(msk->bytes_received) - READ_ONCE(msk->bytes_consumed);
 825}
 826
 827static inline bool mptcp_epollin_ready(const struct sock *sk)
 828{
 829	u64 data_avail = mptcp_data_avail(mptcp_sk(sk));
 830
 831	if (!data_avail)
 832		return false;
 833
 834	/* mptcp doesn't have to deal with small skbs in the receive queue,
 835	 * as it can always coalesce them
 836	 */
 837	return (data_avail >= sk->sk_rcvlowat) ||
 838		tcp_under_memory_pressure(sk);
 839}
 840
 841int mptcp_set_rcvlowat(struct sock *sk, int val);
 842
 843static inline bool __tcp_can_send(const struct sock *ssk)
 844{
 845	/* only send if our side has not closed yet */
 846	return ((1 << inet_sk_state_load(ssk)) & (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT));
 847}
 848
 849static inline bool __mptcp_subflow_active(struct mptcp_subflow_context *subflow)
 850{
 851	/* can't send if JOIN hasn't completed yet (i.e. is usable for mptcp) */
 852	if (subflow->request_join && !READ_ONCE(subflow->fully_established))
 853		return false;
 854
 855	return __tcp_can_send(mptcp_subflow_tcp_sock(subflow));
 856}
 857
 858void mptcp_subflow_set_active(struct mptcp_subflow_context *subflow);
 859
 860bool mptcp_subflow_active(struct mptcp_subflow_context *subflow);
 861
 862void mptcp_subflow_drop_ctx(struct sock *ssk);
 863
 864static inline void mptcp_subflow_tcp_fallback(struct sock *sk,
 865					      struct mptcp_subflow_context *ctx)
 866{
 867	sk->sk_data_ready = sock_def_readable;
 868	sk->sk_state_change = ctx->tcp_state_change;
 869	sk->sk_write_space = sk_stream_write_space;
 870	sk->sk_error_report = ctx->tcp_error_report;
 871
 872	inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops;
 873}
 874
 875void __init mptcp_proto_init(void);
 876#if IS_ENABLED(CONFIG_MPTCP_IPV6)
 877int __init mptcp_proto_v6_init(void);
 878void __init mptcp_subflow_v6_init(void);
 879#endif
 880
 881struct sock *mptcp_sk_clone_init(const struct sock *sk,
 882				 const struct mptcp_options_received *mp_opt,
 883				 struct sock *ssk,
 884				 struct request_sock *req);
 885void mptcp_get_options(const struct sk_buff *skb,
 886		       struct mptcp_options_received *mp_opt);
 887
 888void mptcp_finish_connect(struct sock *sk);
 889void __mptcp_sync_state(struct sock *sk, int state);
 890void mptcp_reset_tout_timer(struct mptcp_sock *msk, unsigned long fail_tout);
 891
 892static inline void mptcp_stop_tout_timer(struct sock *sk)
 893{
 894	if (!inet_csk(sk)->icsk_mtup.probe_timestamp)
 895		return;
 896
 897	sk_stop_timer(sk, &inet_csk(sk)->mptcp_tout_timer);
 898	inet_csk(sk)->icsk_mtup.probe_timestamp = 0;
 899}
 900
 901static inline void mptcp_set_close_tout(struct sock *sk, unsigned long tout)
 902{
 903	/* avoid 0 timestamp, as that means no close timeout */
 904	inet_csk(sk)->icsk_mtup.probe_timestamp = tout ? : 1;
 905}
 906
 907static inline void mptcp_start_tout_timer(struct sock *sk)
 908{
 909	mptcp_set_close_tout(sk, tcp_jiffies32);
 910	mptcp_reset_tout_timer(mptcp_sk(sk), 0);
 911}
 912
 913static inline bool mptcp_is_fully_established(struct sock *sk)
 914{
 915	return inet_sk_state_load(sk) == TCP_ESTABLISHED &&
 916	       READ_ONCE(mptcp_sk(sk)->fully_established);
 917}
 918
 919static inline u64 mptcp_stamp(void)
 920{
 921	return div_u64(tcp_clock_ns(), NSEC_PER_USEC);
 922}
 923
 924void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk);
 925void mptcp_data_ready(struct sock *sk, struct sock *ssk);
 926bool mptcp_finish_join(struct sock *sk);
 927bool mptcp_schedule_work(struct sock *sk);
 928int mptcp_setsockopt(struct sock *sk, int level, int optname,
 929		     sockptr_t optval, unsigned int optlen);
 930int mptcp_getsockopt(struct sock *sk, int level, int optname,
 931		     char __user *optval, int __user *option);
 932
 933u64 __mptcp_expand_seq(u64 old_seq, u64 cur_seq);
 934static inline u64 mptcp_expand_seq(u64 old_seq, u64 cur_seq, bool use_64bit)
 935{
 936	if (use_64bit)
 937		return cur_seq;
 938
 939	return __mptcp_expand_seq(old_seq, cur_seq);
 940}
 941void __mptcp_check_push(struct sock *sk, struct sock *ssk);
 942void __mptcp_data_acked(struct sock *sk);
 943void __mptcp_error_report(struct sock *sk);
 944bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq, bool use_64bit);
 945static inline bool mptcp_data_fin_enabled(const struct mptcp_sock *msk)
 946{
 947	return READ_ONCE(msk->snd_data_fin_enable) &&
 948	       READ_ONCE(msk->write_seq) == READ_ONCE(msk->snd_nxt);
 949}
 950
 951static inline u32 mptcp_notsent_lowat(const struct sock *sk)
 952{
 953	struct net *net = sock_net(sk);
 954	u32 val;
 955
 956	val = READ_ONCE(mptcp_sk(sk)->notsent_lowat);
 957	return val ?: READ_ONCE(net->ipv4.sysctl_tcp_notsent_lowat);
 958}
 959
 960static inline bool mptcp_stream_memory_free(const struct sock *sk, int wake)
 961{
 962	const struct mptcp_sock *msk = mptcp_sk(sk);
 963	u32 notsent_bytes;
 964
 965	notsent_bytes = READ_ONCE(msk->write_seq) - READ_ONCE(msk->snd_nxt);
 966	return (notsent_bytes << wake) < mptcp_notsent_lowat(sk);
 967}
 968
 969static inline bool __mptcp_stream_is_writeable(const struct sock *sk, int wake)
 970{
 971	return mptcp_stream_memory_free(sk, wake) &&
 972	       __sk_stream_is_writeable(sk, wake);
 973}
 974
 975static inline void mptcp_write_space(struct sock *sk)
 976{
 977	/* pairs with memory barrier in mptcp_poll */
 978	smp_mb();
 979	if (mptcp_stream_memory_free(sk, 1))
 980		sk_stream_write_space(sk);
 981}
 982
 983static inline void __mptcp_sync_sndbuf(struct sock *sk)
 984{
 985	struct mptcp_subflow_context *subflow;
 986	int ssk_sndbuf, new_sndbuf;
 987
 988	if (sk->sk_userlocks & SOCK_SNDBUF_LOCK)
 989		return;
 990
 991	new_sndbuf = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_wmem[0]);
 992	mptcp_for_each_subflow(mptcp_sk(sk), subflow) {
 993		ssk_sndbuf =  READ_ONCE(mptcp_subflow_tcp_sock(subflow)->sk_sndbuf);
 994
 995		subflow->cached_sndbuf = ssk_sndbuf;
 996		new_sndbuf += ssk_sndbuf;
 997	}
 998
 999	/* the msk max wmem limit is <nr_subflows> * tcp wmem[2] */
1000	WRITE_ONCE(sk->sk_sndbuf, new_sndbuf);
1001	mptcp_write_space(sk);
1002}
1003
1004/* The called held both the msk socket and the subflow socket locks,
1005 * possibly under BH
1006 */
1007static inline void __mptcp_propagate_sndbuf(struct sock *sk, struct sock *ssk)
1008{
1009	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
1010
1011	if (READ_ONCE(ssk->sk_sndbuf) != subflow->cached_sndbuf)
1012		__mptcp_sync_sndbuf(sk);
1013}
1014
1015/* the caller held only the subflow socket lock, either in process or
1016 * BH context. Additionally this can be called under the msk data lock,
1017 * so we can't acquire such lock here: let the delegate action acquires
1018 * the needed locks in suitable order.
1019 */
1020static inline void mptcp_propagate_sndbuf(struct sock *sk, struct sock *ssk)
1021{
1022	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
1023
1024	if (likely(READ_ONCE(ssk->sk_sndbuf) == subflow->cached_sndbuf))
1025		return;
1026
1027	local_bh_disable();
1028	mptcp_subflow_delegate(subflow, MPTCP_DELEGATE_SNDBUF);
1029	local_bh_enable();
1030}
1031
1032#define MPTCP_TOKEN_MAX_RETRIES	4
1033
1034void __init mptcp_token_init(void);
1035static inline void mptcp_token_init_request(struct request_sock *req)
1036{
1037	mptcp_subflow_rsk(req)->token_node.pprev = NULL;
1038}
1039
1040int mptcp_token_new_request(struct request_sock *req);
1041void mptcp_token_destroy_request(struct request_sock *req);
1042int mptcp_token_new_connect(struct sock *ssk);
1043void mptcp_token_accept(struct mptcp_subflow_request_sock *r,
1044			struct mptcp_sock *msk);
1045bool mptcp_token_exists(u32 token);
1046struct mptcp_sock *mptcp_token_get_sock(struct net *net, u32 token);
1047struct mptcp_sock *mptcp_token_iter_next(const struct net *net, long *s_slot,
1048					 long *s_num);
1049void mptcp_token_destroy(struct mptcp_sock *msk);
1050
1051void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
1052
1053void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
1054__sum16 __mptcp_make_csum(u64 data_seq, u32 subflow_seq, u16 data_len, __wsum sum);
1055
1056void __init mptcp_pm_init(void);
1057void mptcp_pm_data_init(struct mptcp_sock *msk);
1058void mptcp_pm_data_reset(struct mptcp_sock *msk);
1059void mptcp_pm_destroy(struct mptcp_sock *msk);
1060int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
1061			struct mptcp_addr_info *addr);
1062int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,
1063			 bool require_family,
1064			 struct mptcp_pm_addr_entry *entry);
1065bool mptcp_pm_addr_families_match(const struct sock *sk,
1066				  const struct mptcp_addr_info *loc,
1067				  const struct mptcp_addr_info *rem);
1068void mptcp_pm_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk);
1069void mptcp_pm_new_connection(struct mptcp_sock *msk, const struct sock *ssk, int server_side);
1070void mptcp_pm_fully_established(struct mptcp_sock *msk, const struct sock *ssk);
1071bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk);
1072void mptcp_pm_connection_closed(struct mptcp_sock *msk);
1073void mptcp_pm_subflow_established(struct mptcp_sock *msk);
1074bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk);
1075void mptcp_pm_subflow_check_next(struct mptcp_sock *msk,
1076				 const struct mptcp_subflow_context *subflow);
1077void mptcp_pm_add_addr_received(const struct sock *ssk,
1078				const struct mptcp_addr_info *addr);
1079void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
1080			      const struct mptcp_addr_info *addr);
1081void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk);
1082void mptcp_pm_send_ack(struct mptcp_sock *msk,
1083		       struct mptcp_subflow_context *subflow,
1084		       bool prio, bool backup);
1085void mptcp_pm_addr_send_ack(struct mptcp_sock *msk);
1086void mptcp_pm_nl_rm_addr(struct mptcp_sock *msk, u8 rm_id);
1087void mptcp_pm_rm_subflow(struct mptcp_sock *msk,
1088			 const struct mptcp_rm_list *rm_list);
1089void mptcp_pm_rm_addr_received(struct mptcp_sock *msk,
1090			       const struct mptcp_rm_list *rm_list);
1091void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup);
1092void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq);
1093int mptcp_pm_mp_prio_send_ack(struct mptcp_sock *msk,
1094			      struct mptcp_addr_info *addr,
1095			      struct mptcp_addr_info *rem,
1096			      u8 bkup);
1097bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
1098			      const struct mptcp_addr_info *addr);
1099bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk);
1100struct mptcp_pm_add_entry *
1101mptcp_pm_del_add_timer(struct mptcp_sock *msk,
1102		       const struct mptcp_addr_info *addr, bool check_id);
1103bool mptcp_lookup_subflow_by_saddr(const struct list_head *list,
1104				   const struct mptcp_addr_info *saddr);
1105bool mptcp_remove_anno_list_by_saddr(struct mptcp_sock *msk,
1106				     const struct mptcp_addr_info *addr);
1107int mptcp_pm_nl_set_flags(struct mptcp_pm_addr_entry *local,
1108			  struct genl_info *info);
1109int mptcp_userspace_pm_set_flags(struct mptcp_pm_addr_entry *local,
1110				 struct genl_info *info);
1111int mptcp_pm_announce_addr(struct mptcp_sock *msk,
1112			   const struct mptcp_addr_info *addr,
1113			   bool echo);
1114int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list);
1115void mptcp_pm_remove_addr_entry(struct mptcp_sock *msk,
1116				struct mptcp_pm_addr_entry *entry);
1117
1118/* the default path manager, used in mptcp_pm_unregister */
1119extern struct mptcp_pm_ops mptcp_pm_kernel;
1120
1121struct mptcp_pm_ops *mptcp_pm_find(const char *name);
1122int mptcp_pm_register(struct mptcp_pm_ops *pm_ops);
1123void mptcp_pm_unregister(struct mptcp_pm_ops *pm_ops);
1124int mptcp_pm_validate(struct mptcp_pm_ops *pm_ops);
1125void mptcp_pm_get_available(char *buf, size_t maxlen);
1126
1127void mptcp_userspace_pm_free_local_addr_list(struct mptcp_sock *msk);
1128
1129void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
1130		 const struct sock *ssk, gfp_t gfp);
1131void mptcp_event_addr_announced(const struct sock *ssk, const struct mptcp_addr_info *info);
1132void mptcp_event_addr_removed(const struct mptcp_sock *msk, u8 id);
1133void mptcp_event_pm_listener(const struct sock *ssk,
1134			     enum mptcp_event_type event);
1135bool mptcp_userspace_pm_active(const struct mptcp_sock *msk);
1136
1137void mptcp_fastopen_subflow_synack_set_params(struct mptcp_subflow_context *subflow,
1138					      struct request_sock *req);
1139int mptcp_pm_genl_fill_addr(struct sk_buff *msg,
1140			    struct netlink_callback *cb,
1141			    struct mptcp_pm_addr_entry *entry);
1142
1143static inline bool mptcp_pm_should_add_signal(struct mptcp_sock *msk)
1144{
1145	return READ_ONCE(msk->pm.addr_signal) &
1146		(BIT(MPTCP_ADD_ADDR_SIGNAL) | BIT(MPTCP_ADD_ADDR_ECHO));
1147}
1148
1149static inline bool mptcp_pm_should_add_signal_addr(struct mptcp_sock *msk)
1150{
1151	return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_SIGNAL);
1152}
1153
1154static inline bool mptcp_pm_should_add_signal_echo(struct mptcp_sock *msk)
1155{
1156	return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_ADD_ADDR_ECHO);
1157}
1158
1159static inline bool mptcp_pm_should_rm_signal(struct mptcp_sock *msk)
1160{
1161	return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_RM_ADDR_SIGNAL);
1162}
1163
1164static inline bool mptcp_pm_is_userspace(const struct mptcp_sock *msk)
1165{
1166	return READ_ONCE(msk->pm.pm_type) == MPTCP_PM_TYPE_USERSPACE;
1167}
1168
1169static inline bool mptcp_pm_is_kernel(const struct mptcp_sock *msk)
1170{
1171	return READ_ONCE(msk->pm.pm_type) == MPTCP_PM_TYPE_KERNEL;
1172}
1173
1174static inline unsigned int mptcp_add_addr_len(int family, bool echo, bool port)
1175{
1176	u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE;
1177
1178	if (family == AF_INET6)
1179		len = TCPOLEN_MPTCP_ADD_ADDR6_BASE;
1180	if (!echo)
1181		len += MPTCPOPT_THMAC_LEN;
1182	/* account for 2 trailing 'nop' options */
1183	if (port)
1184		len += TCPOLEN_MPTCP_PORT_LEN + TCPOLEN_MPTCP_PORT_ALIGN;
1185
1186	return len;
1187}
1188
1189static inline int mptcp_rm_addr_len(const struct mptcp_rm_list *rm_list)
1190{
1191	if (rm_list->nr == 0 || rm_list->nr > MPTCP_RM_IDS_MAX)
1192		return -EINVAL;
1193
1194	return TCPOLEN_MPTCP_RM_ADDR_BASE + roundup(rm_list->nr - 1, 4) + 1;
1195}
1196
1197bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
1198			      unsigned int opt_size, unsigned int remaining,
1199			      struct mptcp_addr_info *addr, bool *echo,
1200			      bool *drop_other_suboptions);
1201bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
1202			     struct mptcp_rm_list *rm_list);
1203int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);
1204int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk,
1205			     struct mptcp_pm_addr_entry *skc);
1206int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
1207				    struct mptcp_pm_addr_entry *skc);
1208bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc);
1209bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
1210bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc);
1211int mptcp_pm_nl_dump_addr(struct sk_buff *msg,
1212			  struct netlink_callback *cb);
1213int mptcp_userspace_pm_dump_addr(struct sk_buff *msg,
1214				 struct netlink_callback *cb);
1215int mptcp_pm_nl_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
1216			 struct genl_info *info);
1217int mptcp_userspace_pm_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
1218				struct genl_info *info);
1219
1220static inline u8 subflow_get_local_id(const struct mptcp_subflow_context *subflow)
1221{
1222	int local_id = READ_ONCE(subflow->local_id);
1223
1224	if (local_id < 0)
1225		return 0;
1226	return local_id;
1227}
1228
1229void __init mptcp_pm_kernel_register(void);
1230void __init mptcp_pm_userspace_register(void);
1231void __init mptcp_pm_nl_init(void);
1232void mptcp_pm_worker(struct mptcp_sock *msk);
1233void __mptcp_pm_kernel_worker(struct mptcp_sock *msk);
1234u8 mptcp_pm_get_endp_signal_max(const struct mptcp_sock *msk);
1235u8 mptcp_pm_get_endp_subflow_max(const struct mptcp_sock *msk);
1236u8 mptcp_pm_get_endp_laminar_max(const struct mptcp_sock *msk);
1237u8 mptcp_pm_get_endp_fullmesh_max(const struct mptcp_sock *msk);
1238u8 mptcp_pm_get_limit_add_addr_accepted(const struct mptcp_sock *msk);
1239u8 mptcp_pm_get_limit_extra_subflows(const struct mptcp_sock *msk);
1240
1241/* called under PM lock */
1242static inline void __mptcp_pm_close_subflow(struct mptcp_sock *msk)
1243{
1244	if (--msk->pm.extra_subflows < mptcp_pm_get_limit_extra_subflows(msk))
1245		WRITE_ONCE(msk->pm.accept_subflow, true);
1246}
1247
1248static inline void mptcp_pm_close_subflow(struct mptcp_sock *msk)
1249{
1250	spin_lock_bh(&msk->pm.lock);
1251	__mptcp_pm_close_subflow(msk);
1252	spin_unlock_bh(&msk->pm.lock);
1253}
1254
1255static inline bool mptcp_pm_add_addr_c_flag_case(struct mptcp_sock *msk)
1256{
1257	return READ_ONCE(msk->pm.remote_deny_join_id0) &&
1258	       msk->pm.local_addr_used == 0 &&
1259	       mptcp_pm_get_limit_add_addr_accepted(msk) == 0 &&
1260	       msk->pm.extra_subflows < mptcp_pm_get_limit_extra_subflows(msk);
1261}
1262
1263void mptcp_sockopt_sync_locked(struct mptcp_sock *msk, struct sock *ssk);
1264
1265static inline struct mptcp_ext *mptcp_get_ext(const struct sk_buff *skb)
1266{
1267	return (struct mptcp_ext *)skb_ext_find(skb, SKB_EXT_MPTCP);
1268}
1269
1270void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops);
1271
1272static inline bool __mptcp_check_fallback(const struct mptcp_sock *msk)
1273{
1274	return test_bit(MPTCP_FALLBACK_DONE, &msk->flags);
1275}
1276
1277static inline bool mptcp_check_fallback(const struct sock *sk)
1278{
1279	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
1280	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
1281
1282	return __mptcp_check_fallback(msk);
1283}
1284
1285static inline bool __mptcp_has_initial_subflow(const struct mptcp_sock *msk)
1286{
1287	struct sock *ssk = READ_ONCE(msk->first);
1288
1289	return ssk && ((1 << inet_sk_state_load(ssk)) &
1290		       (TCPF_ESTABLISHED | TCPF_SYN_SENT |
1291			TCPF_SYN_RECV | TCPF_LISTEN));
1292}
1293
1294bool __mptcp_try_fallback(struct mptcp_sock *msk, int fb_mib);
1295
1296static inline bool mptcp_try_fallback(struct sock *ssk, int fb_mib)
1297{
1298	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
1299	struct sock *sk = subflow->conn;
1300	struct mptcp_sock *msk;
1301
1302	msk = mptcp_sk(sk);
1303	if (!__mptcp_try_fallback(msk, fb_mib))
1304		return false;
1305	if (READ_ONCE(msk->snd_data_fin_enable) && !(ssk->sk_shutdown & SEND_SHUTDOWN)) {
1306		gfp_t saved_allocation = ssk->sk_allocation;
1307
1308		/* we are in a atomic (BH) scope, override ssk default for data
1309		 * fin allocation
1310		 */
1311		ssk->sk_allocation = GFP_ATOMIC;
1312		ssk->sk_shutdown |= SEND_SHUTDOWN;
1313		tcp_shutdown(ssk, SEND_SHUTDOWN);
1314		ssk->sk_allocation = saved_allocation;
1315	}
1316	return true;
1317}
1318
1319static inline void mptcp_early_fallback(struct mptcp_sock *msk,
1320					struct mptcp_subflow_context *subflow,
1321					int fb_mib)
1322{
1323	subflow->request_mptcp = 0;
1324	WARN_ON_ONCE(!__mptcp_try_fallback(msk, fb_mib));
1325}
1326
1327static inline bool mptcp_check_infinite_map(struct sk_buff *skb)
1328{
1329	struct mptcp_ext *mpext;
1330
1331	mpext = skb ? mptcp_get_ext(skb) : NULL;
1332	if (mpext && mpext->infinite_map)
1333		return true;
1334
1335	return false;
1336}
1337
1338static inline bool is_active_ssk(struct mptcp_subflow_context *subflow)
1339{
1340	return (subflow->request_mptcp || subflow->request_join);
1341}
1342
1343static inline bool subflow_simultaneous_connect(struct sock *sk)
1344{
1345	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
1346
1347	/* Note that the sk state implies !subflow->conn_finished. */
1348	return sk->sk_state == TCP_SYN_RECV && is_active_ssk(subflow);
1349}
1350
1351#ifdef CONFIG_SYN_COOKIES
1352void subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
1353				       struct sk_buff *skb);
1354bool mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
1355					struct sk_buff *skb);
1356void __init mptcp_join_cookie_init(void);
1357#else
1358static inline void
1359subflow_init_req_cookie_join_save(const struct mptcp_subflow_request_sock *subflow_req,
1360				  struct sk_buff *skb) {}
1361static inline bool
1362mptcp_token_join_cookie_init_state(struct mptcp_subflow_request_sock *subflow_req,
1363				   struct sk_buff *skb)
1364{
1365	return false;
1366}
1367
1368static inline void mptcp_join_cookie_init(void) {}
1369#endif
1370
1371#endif /* __MPTCP_PROTOCOL_H */