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sm_make_chunk.c
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linux-6.19.14/net/sctp/sm_make_chunk.c
1// SPDX-License-Identifier: GPL-2.0-or-later 2/* SCTP kernel implementation 3 * (C) Copyright IBM Corp. 2001, 2004 4 * Copyright (c) 1999-2000 Cisco, Inc. 5 * Copyright (c) 1999-2001 Motorola, Inc. 6 * Copyright (c) 2001-2002 Intel Corp. 7 * 8 * This file is part of the SCTP kernel implementation 9 * 10 * These functions work with the state functions in sctp_sm_statefuns.c 11 * to implement the state operations. These functions implement the 12 * steps which require modifying existing data structures. 13 * 14 * Please send any bug reports or fixes you make to the 15 * email address(es): 16 * lksctp developers <linux-sctp@vger.kernel.org> 17 * 18 * Written or modified by: 19 * La Monte H.P. Yarroll <piggy@acm.org> 20 * Karl Knutson <karl@athena.chicago.il.us> 21 * C. Robin <chris@hundredacre.ac.uk> 22 * Jon Grimm <jgrimm@us.ibm.com> 23 * Xingang Guo <xingang.guo@intel.com> 24 * Dajiang Zhang <dajiang.zhang@nokia.com> 25 * Sridhar Samudrala <sri@us.ibm.com> 26 * Daisy Chang <daisyc@us.ibm.com> 27 * Ardelle Fan <ardelle.fan@intel.com> 28 * Kevin Gao <kevin.gao@intel.com> 29 */ 30 31#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 32 33#include <crypto/utils.h> 34#include <linux/types.h> 35#include <linux/kernel.h> 36#include <linux/ip.h> 37#include <linux/ipv6.h> 38#include <linux/net.h> 39#include <linux/inet.h> 40#include <linux/scatterlist.h> 41#include <linux/slab.h> 42#include <net/sock.h> 43 44#include <linux/skbuff.h> 45#include <linux/random.h> /* for get_random_bytes */ 46#include <net/sctp/sctp.h> 47#include <net/sctp/sm.h> 48 49static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 50 __u8 type, __u8 flags, int paylen, 51 gfp_t gfp); 52static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 53 __u8 flags, int paylen, gfp_t gfp); 54static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 55 __u8 type, __u8 flags, int paylen, 56 gfp_t gfp); 57static struct sctp_cookie_param *sctp_pack_cookie( 58 const struct sctp_endpoint *ep, 59 const struct sctp_association *asoc, 60 const struct sctp_chunk *init_chunk, 61 int *cookie_len, 62 const __u8 *raw_addrs, int addrs_len); 63static int sctp_process_param(struct sctp_association *asoc, 64 union sctp_params param, 65 const union sctp_addr *peer_addr, 66 gfp_t gfp); 67static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 68 const void *data); 69 70/* Control chunk destructor */ 71static void sctp_control_release_owner(struct sk_buff *skb) 72{ 73 struct sctp_chunk *chunk = skb_shinfo(skb)->destructor_arg; 74 75 if (chunk->shkey) { 76 struct sctp_shared_key *shkey = chunk->shkey; 77 struct sctp_association *asoc = chunk->asoc; 78 79 /* refcnt == 2 and !list_empty mean after this release, it's 80 * not being used anywhere, and it's time to notify userland 81 * that this shkey can be freed if it's been deactivated. 82 */ 83 if (shkey->deactivated && !list_empty(&shkey->key_list) && 84 refcount_read(&shkey->refcnt) == 2) { 85 struct sctp_ulpevent *ev; 86 87 ev = sctp_ulpevent_make_authkey(asoc, shkey->key_id, 88 SCTP_AUTH_FREE_KEY, 89 GFP_KERNEL); 90 if (ev) 91 asoc->stream.si->enqueue_event(&asoc->ulpq, ev); 92 } 93 sctp_auth_shkey_release(chunk->shkey); 94 } 95} 96 97static void sctp_control_set_owner_w(struct sctp_chunk *chunk) 98{ 99 struct sctp_association *asoc = chunk->asoc; 100 struct sk_buff *skb = chunk->skb; 101 102 /* TODO: properly account for control chunks. 103 * To do it right we'll need: 104 * 1) endpoint if association isn't known. 105 * 2) proper memory accounting. 106 * 107 * For now don't do anything for now. 108 */ 109 if (chunk->auth) { 110 chunk->shkey = asoc->shkey; 111 sctp_auth_shkey_hold(chunk->shkey); 112 } 113 skb->sk = asoc ? asoc->base.sk : NULL; 114 skb_shinfo(skb)->destructor_arg = chunk; 115 skb->destructor = sctp_control_release_owner; 116} 117 118/* RFC 2960 3.3.2 Initiation (INIT) (1) 119 * 120 * Note 2: The ECN capable field is reserved for future use of 121 * Explicit Congestion Notification. 122 */ 123static const struct sctp_paramhdr ecap_param = { 124 SCTP_PARAM_ECN_CAPABLE, 125 cpu_to_be16(sizeof(struct sctp_paramhdr)), 126}; 127static const struct sctp_paramhdr prsctp_param = { 128 SCTP_PARAM_FWD_TSN_SUPPORT, 129 cpu_to_be16(sizeof(struct sctp_paramhdr)), 130}; 131 132/* A helper to initialize an op error inside a provided chunk, as most 133 * cause codes will be embedded inside an abort chunk. 134 */ 135int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, 136 size_t paylen) 137{ 138 struct sctp_errhdr err; 139 __u16 len; 140 141 /* Cause code constants are now defined in network order. */ 142 err.cause = cause_code; 143 len = sizeof(err) + paylen; 144 err.length = htons(len); 145 146 if (skb_tailroom(chunk->skb) < len) 147 return -ENOSPC; 148 149 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(err), &err); 150 151 return 0; 152} 153 154/* 3.3.2 Initiation (INIT) (1) 155 * 156 * This chunk is used to initiate a SCTP association between two 157 * endpoints. The format of the INIT chunk is shown below: 158 * 159 * 0 1 2 3 160 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 161 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 162 * | Type = 1 | Chunk Flags | Chunk Length | 163 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 164 * | Initiate Tag | 165 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 166 * | Advertised Receiver Window Credit (a_rwnd) | 167 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 168 * | Number of Outbound Streams | Number of Inbound Streams | 169 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 170 * | Initial TSN | 171 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 172 * \ \ 173 * / Optional/Variable-Length Parameters / 174 * \ \ 175 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 176 * 177 * 178 * The INIT chunk contains the following parameters. Unless otherwise 179 * noted, each parameter MUST only be included once in the INIT chunk. 180 * 181 * Fixed Parameters Status 182 * ---------------------------------------------- 183 * Initiate Tag Mandatory 184 * Advertised Receiver Window Credit Mandatory 185 * Number of Outbound Streams Mandatory 186 * Number of Inbound Streams Mandatory 187 * Initial TSN Mandatory 188 * 189 * Variable Parameters Status Type Value 190 * ------------------------------------------------------------- 191 * IPv4 Address (Note 1) Optional 5 192 * IPv6 Address (Note 1) Optional 6 193 * Cookie Preservative Optional 9 194 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000) 195 * Host Name Address (Note 3) Optional 11 196 * Supported Address Types (Note 4) Optional 12 197 */ 198struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc, 199 const struct sctp_bind_addr *bp, 200 gfp_t gfp, int vparam_len) 201{ 202 struct sctp_supported_ext_param ext_param; 203 struct sctp_adaptation_ind_param aiparam; 204 struct sctp_paramhdr *auth_chunks = NULL; 205 struct sctp_paramhdr *auth_hmacs = NULL; 206 struct sctp_supported_addrs_param sat; 207 struct sctp_endpoint *ep = asoc->ep; 208 struct sctp_chunk *retval = NULL; 209 int num_types, addrs_len = 0; 210 struct sctp_inithdr init; 211 union sctp_params addrs; 212 struct sctp_sock *sp; 213 __u8 extensions[5]; 214 size_t chunksize; 215 __be16 types[2]; 216 int num_ext = 0; 217 218 /* RFC 2960 3.3.2 Initiation (INIT) (1) 219 * 220 * Note 1: The INIT chunks can contain multiple addresses that 221 * can be IPv4 and/or IPv6 in any combination. 222 */ 223 224 /* Convert the provided bind address list to raw format. */ 225 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp); 226 227 init.init_tag = htonl(asoc->c.my_vtag); 228 init.a_rwnd = htonl(asoc->rwnd); 229 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 230 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 231 init.initial_tsn = htonl(asoc->c.initial_tsn); 232 233 /* How many address types are needed? */ 234 sp = sctp_sk(asoc->base.sk); 235 num_types = sp->pf->supported_addrs(sp, types); 236 237 chunksize = sizeof(init) + addrs_len; 238 chunksize += SCTP_PAD4(SCTP_SAT_LEN(num_types)); 239 240 if (asoc->ep->ecn_enable) 241 chunksize += sizeof(ecap_param); 242 243 if (asoc->ep->prsctp_enable) 244 chunksize += sizeof(prsctp_param); 245 246 /* ADDIP: Section 4.2.7: 247 * An implementation supporting this extension [ADDIP] MUST list 248 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and 249 * INIT-ACK parameters. 250 */ 251 if (asoc->ep->asconf_enable) { 252 extensions[num_ext] = SCTP_CID_ASCONF; 253 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 254 num_ext += 2; 255 } 256 257 if (asoc->ep->reconf_enable) { 258 extensions[num_ext] = SCTP_CID_RECONF; 259 num_ext += 1; 260 } 261 262 if (sp->adaptation_ind) 263 chunksize += sizeof(aiparam); 264 265 if (asoc->ep->intl_enable) { 266 extensions[num_ext] = SCTP_CID_I_DATA; 267 num_ext += 1; 268 } 269 270 chunksize += vparam_len; 271 272 /* Account for AUTH related parameters */ 273 if (ep->auth_enable) { 274 /* Add random parameter length*/ 275 chunksize += sizeof(asoc->c.auth_random); 276 277 /* Add HMACS parameter length if any were defined */ 278 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; 279 if (auth_hmacs->length) 280 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 281 else 282 auth_hmacs = NULL; 283 284 /* Add CHUNKS parameter length */ 285 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; 286 if (auth_chunks->length) 287 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 288 else 289 auth_chunks = NULL; 290 291 extensions[num_ext] = SCTP_CID_AUTH; 292 num_ext += 1; 293 } 294 295 /* If we have any extensions to report, account for that */ 296 if (num_ext) 297 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext); 298 299 /* RFC 2960 3.3.2 Initiation (INIT) (1) 300 * 301 * Note 3: An INIT chunk MUST NOT contain more than one Host 302 * Name address parameter. Moreover, the sender of the INIT 303 * MUST NOT combine any other address types with the Host Name 304 * address in the INIT. The receiver of INIT MUST ignore any 305 * other address types if the Host Name address parameter is 306 * present in the received INIT chunk. 307 * 308 * PLEASE DO NOT FIXME [This version does not support Host Name.] 309 */ 310 311 retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp); 312 if (!retval) 313 goto nodata; 314 315 retval->subh.init_hdr = 316 sctp_addto_chunk(retval, sizeof(init), &init); 317 retval->param_hdr.v = 318 sctp_addto_chunk(retval, addrs_len, addrs.v); 319 320 /* RFC 2960 3.3.2 Initiation (INIT) (1) 321 * 322 * Note 4: This parameter, when present, specifies all the 323 * address types the sending endpoint can support. The absence 324 * of this parameter indicates that the sending endpoint can 325 * support any address type. 326 */ 327 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES; 328 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types)); 329 sctp_addto_chunk(retval, sizeof(sat), &sat); 330 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types); 331 332 if (asoc->ep->ecn_enable) 333 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 334 335 /* Add the supported extensions parameter. Be nice and add this 336 * fist before addiding the parameters for the extensions themselves 337 */ 338 if (num_ext) { 339 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 340 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext); 341 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); 342 sctp_addto_param(retval, num_ext, extensions); 343 } 344 345 if (asoc->ep->prsctp_enable) 346 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 347 348 if (sp->adaptation_ind) { 349 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 350 aiparam.param_hdr.length = htons(sizeof(aiparam)); 351 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 352 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 353 } 354 355 /* Add SCTP-AUTH chunks to the parameter list */ 356 if (ep->auth_enable) { 357 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random), 358 asoc->c.auth_random); 359 if (auth_hmacs) 360 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 361 auth_hmacs); 362 if (auth_chunks) 363 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 364 auth_chunks); 365 } 366nodata: 367 kfree(addrs.v); 368 return retval; 369} 370 371struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, 372 const struct sctp_chunk *chunk, 373 gfp_t gfp, int unkparam_len) 374{ 375 struct sctp_supported_ext_param ext_param; 376 struct sctp_adaptation_ind_param aiparam; 377 struct sctp_paramhdr *auth_chunks = NULL; 378 struct sctp_paramhdr *auth_random = NULL; 379 struct sctp_paramhdr *auth_hmacs = NULL; 380 struct sctp_chunk *retval = NULL; 381 struct sctp_cookie_param *cookie; 382 struct sctp_inithdr initack; 383 union sctp_params addrs; 384 struct sctp_sock *sp; 385 __u8 extensions[5]; 386 size_t chunksize; 387 int num_ext = 0; 388 int cookie_len; 389 int addrs_len; 390 391 /* Note: there may be no addresses to embed. */ 392 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp); 393 394 initack.init_tag = htonl(asoc->c.my_vtag); 395 initack.a_rwnd = htonl(asoc->rwnd); 396 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 397 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 398 initack.initial_tsn = htonl(asoc->c.initial_tsn); 399 400 /* FIXME: We really ought to build the cookie right 401 * into the packet instead of allocating more fresh memory. 402 */ 403 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len, 404 addrs.v, addrs_len); 405 if (!cookie) 406 goto nomem_cookie; 407 408 /* Calculate the total size of allocation, include the reserved 409 * space for reporting unknown parameters if it is specified. 410 */ 411 sp = sctp_sk(asoc->base.sk); 412 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len; 413 414 /* Tell peer that we'll do ECN only if peer advertised such cap. */ 415 if (asoc->peer.ecn_capable) 416 chunksize += sizeof(ecap_param); 417 418 if (asoc->peer.prsctp_capable) 419 chunksize += sizeof(prsctp_param); 420 421 if (asoc->peer.asconf_capable) { 422 extensions[num_ext] = SCTP_CID_ASCONF; 423 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 424 num_ext += 2; 425 } 426 427 if (asoc->peer.reconf_capable) { 428 extensions[num_ext] = SCTP_CID_RECONF; 429 num_ext += 1; 430 } 431 432 if (sp->adaptation_ind) 433 chunksize += sizeof(aiparam); 434 435 if (asoc->peer.intl_capable) { 436 extensions[num_ext] = SCTP_CID_I_DATA; 437 num_ext += 1; 438 } 439 440 if (asoc->peer.auth_capable) { 441 auth_random = (struct sctp_paramhdr *)asoc->c.auth_random; 442 chunksize += ntohs(auth_random->length); 443 444 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; 445 if (auth_hmacs->length) 446 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 447 else 448 auth_hmacs = NULL; 449 450 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; 451 if (auth_chunks->length) 452 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 453 else 454 auth_chunks = NULL; 455 456 extensions[num_ext] = SCTP_CID_AUTH; 457 num_ext += 1; 458 } 459 460 if (num_ext) 461 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext); 462 463 /* Now allocate and fill out the chunk. */ 464 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp); 465 if (!retval) 466 goto nomem_chunk; 467 468 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 469 * 470 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 471 * HEARTBEAT ACK, * etc.) to the same destination transport 472 * address from which it received the DATA or control chunk 473 * to which it is replying. 474 * 475 * [INIT ACK back to where the INIT came from.] 476 */ 477 if (chunk->transport) 478 retval->transport = 479 sctp_assoc_lookup_paddr(asoc, 480 &chunk->transport->ipaddr); 481 482 retval->subh.init_hdr = 483 sctp_addto_chunk(retval, sizeof(initack), &initack); 484 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); 485 sctp_addto_chunk(retval, cookie_len, cookie); 486 if (asoc->peer.ecn_capable) 487 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 488 if (num_ext) { 489 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 490 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext); 491 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); 492 sctp_addto_param(retval, num_ext, extensions); 493 } 494 if (asoc->peer.prsctp_capable) 495 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 496 497 if (sp->adaptation_ind) { 498 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 499 aiparam.param_hdr.length = htons(sizeof(aiparam)); 500 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 501 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 502 } 503 504 if (asoc->peer.auth_capable) { 505 sctp_addto_chunk(retval, ntohs(auth_random->length), 506 auth_random); 507 if (auth_hmacs) 508 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 509 auth_hmacs); 510 if (auth_chunks) 511 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 512 auth_chunks); 513 } 514 515 /* We need to remove the const qualifier at this point. */ 516 retval->asoc = (struct sctp_association *) asoc; 517 518nomem_chunk: 519 kfree(cookie); 520nomem_cookie: 521 kfree(addrs.v); 522 return retval; 523} 524 525/* 3.3.11 Cookie Echo (COOKIE ECHO) (10): 526 * 527 * This chunk is used only during the initialization of an association. 528 * It is sent by the initiator of an association to its peer to complete 529 * the initialization process. This chunk MUST precede any DATA chunk 530 * sent within the association, but MAY be bundled with one or more DATA 531 * chunks in the same packet. 532 * 533 * 0 1 2 3 534 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 535 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 536 * | Type = 10 |Chunk Flags | Length | 537 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 538 * / Cookie / 539 * \ \ 540 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 541 * 542 * Chunk Flags: 8 bit 543 * 544 * Set to zero on transmit and ignored on receipt. 545 * 546 * Length: 16 bits (unsigned integer) 547 * 548 * Set to the size of the chunk in bytes, including the 4 bytes of 549 * the chunk header and the size of the Cookie. 550 * 551 * Cookie: variable size 552 * 553 * This field must contain the exact cookie received in the 554 * State Cookie parameter from the previous INIT ACK. 555 * 556 * An implementation SHOULD make the cookie as small as possible 557 * to insure interoperability. 558 */ 559struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, 560 const struct sctp_chunk *chunk) 561{ 562 struct sctp_chunk *retval; 563 int cookie_len; 564 void *cookie; 565 566 cookie = asoc->peer.cookie; 567 cookie_len = asoc->peer.cookie_len; 568 569 /* Build a cookie echo chunk. */ 570 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0, 571 cookie_len, GFP_ATOMIC); 572 if (!retval) 573 goto nodata; 574 retval->subh.cookie_hdr = 575 sctp_addto_chunk(retval, cookie_len, cookie); 576 577 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 578 * 579 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 580 * HEARTBEAT ACK, * etc.) to the same destination transport 581 * address from which it * received the DATA or control chunk 582 * to which it is replying. 583 * 584 * [COOKIE ECHO back to where the INIT ACK came from.] 585 */ 586 if (chunk) 587 retval->transport = chunk->transport; 588 589nodata: 590 return retval; 591} 592 593/* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11): 594 * 595 * This chunk is used only during the initialization of an 596 * association. It is used to acknowledge the receipt of a COOKIE 597 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent 598 * within the association, but MAY be bundled with one or more DATA 599 * chunks or SACK chunk in the same SCTP packet. 600 * 601 * 0 1 2 3 602 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 603 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 604 * | Type = 11 |Chunk Flags | Length = 4 | 605 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 606 * 607 * Chunk Flags: 8 bits 608 * 609 * Set to zero on transmit and ignored on receipt. 610 */ 611struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, 612 const struct sctp_chunk *chunk) 613{ 614 struct sctp_chunk *retval; 615 616 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC); 617 618 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 619 * 620 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 621 * HEARTBEAT ACK, * etc.) to the same destination transport 622 * address from which it * received the DATA or control chunk 623 * to which it is replying. 624 * 625 * [COOKIE ACK back to where the COOKIE ECHO came from.] 626 */ 627 if (retval && chunk && chunk->transport) 628 retval->transport = 629 sctp_assoc_lookup_paddr(asoc, 630 &chunk->transport->ipaddr); 631 632 return retval; 633} 634 635/* 636 * Appendix A: Explicit Congestion Notification: 637 * CWR: 638 * 639 * RFC 2481 details a specific bit for a sender to send in the header of 640 * its next outbound TCP segment to indicate to its peer that it has 641 * reduced its congestion window. This is termed the CWR bit. For 642 * SCTP the same indication is made by including the CWR chunk. 643 * This chunk contains one data element, i.e. the TSN number that 644 * was sent in the ECNE chunk. This element represents the lowest 645 * TSN number in the datagram that was originally marked with the 646 * CE bit. 647 * 648 * 0 1 2 3 649 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 650 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 651 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 | 652 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 653 * | Lowest TSN Number | 654 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 655 * 656 * Note: The CWR is considered a Control chunk. 657 */ 658struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, 659 const __u32 lowest_tsn, 660 const struct sctp_chunk *chunk) 661{ 662 struct sctp_chunk *retval; 663 struct sctp_cwrhdr cwr; 664 665 cwr.lowest_tsn = htonl(lowest_tsn); 666 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0, 667 sizeof(cwr), GFP_ATOMIC); 668 669 if (!retval) 670 goto nodata; 671 672 retval->subh.ecn_cwr_hdr = 673 sctp_addto_chunk(retval, sizeof(cwr), &cwr); 674 675 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 676 * 677 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 678 * HEARTBEAT ACK, * etc.) to the same destination transport 679 * address from which it * received the DATA or control chunk 680 * to which it is replying. 681 * 682 * [Report a reduced congestion window back to where the ECNE 683 * came from.] 684 */ 685 if (chunk) 686 retval->transport = chunk->transport; 687 688nodata: 689 return retval; 690} 691 692/* Make an ECNE chunk. This is a congestion experienced report. */ 693struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, 694 const __u32 lowest_tsn) 695{ 696 struct sctp_chunk *retval; 697 struct sctp_ecnehdr ecne; 698 699 ecne.lowest_tsn = htonl(lowest_tsn); 700 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0, 701 sizeof(ecne), GFP_ATOMIC); 702 if (!retval) 703 goto nodata; 704 retval->subh.ecne_hdr = 705 sctp_addto_chunk(retval, sizeof(ecne), &ecne); 706 707nodata: 708 return retval; 709} 710 711/* Make a DATA chunk for the given association from the provided 712 * parameters. However, do not populate the data payload. 713 */ 714struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc, 715 const struct sctp_sndrcvinfo *sinfo, 716 int len, __u8 flags, gfp_t gfp) 717{ 718 struct sctp_chunk *retval; 719 struct sctp_datahdr dp; 720 721 /* We assign the TSN as LATE as possible, not here when 722 * creating the chunk. 723 */ 724 memset(&dp, 0, sizeof(dp)); 725 dp.ppid = sinfo->sinfo_ppid; 726 dp.stream = htons(sinfo->sinfo_stream); 727 728 /* Set the flags for an unordered send. */ 729 if (sinfo->sinfo_flags & SCTP_UNORDERED) 730 flags |= SCTP_DATA_UNORDERED; 731 732 retval = sctp_make_data(asoc, flags, sizeof(dp) + len, gfp); 733 if (!retval) 734 return NULL; 735 736 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp); 737 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo)); 738 739 return retval; 740} 741 742/* Create a selective ackowledgement (SACK) for the given 743 * association. This reports on which TSN's we've seen to date, 744 * including duplicates and gaps. 745 */ 746struct sctp_chunk *sctp_make_sack(struct sctp_association *asoc) 747{ 748 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; 749 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; 750 __u16 num_gabs, num_dup_tsns; 751 struct sctp_transport *trans; 752 struct sctp_chunk *retval; 753 struct sctp_sackhdr sack; 754 __u32 ctsn; 755 int len; 756 757 memset(gabs, 0, sizeof(gabs)); 758 ctsn = sctp_tsnmap_get_ctsn(map); 759 760 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn); 761 762 /* How much room is needed in the chunk? */ 763 num_gabs = sctp_tsnmap_num_gabs(map, gabs); 764 num_dup_tsns = sctp_tsnmap_num_dups(map); 765 766 /* Initialize the SACK header. */ 767 sack.cum_tsn_ack = htonl(ctsn); 768 sack.a_rwnd = htonl(asoc->a_rwnd); 769 sack.num_gap_ack_blocks = htons(num_gabs); 770 sack.num_dup_tsns = htons(num_dup_tsns); 771 772 len = sizeof(sack) 773 + sizeof(struct sctp_gap_ack_block) * num_gabs 774 + sizeof(__u32) * num_dup_tsns; 775 776 /* Create the chunk. */ 777 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC); 778 if (!retval) 779 goto nodata; 780 781 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 782 * 783 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 784 * HEARTBEAT ACK, etc.) to the same destination transport 785 * address from which it received the DATA or control chunk to 786 * which it is replying. This rule should also be followed if 787 * the endpoint is bundling DATA chunks together with the 788 * reply chunk. 789 * 790 * However, when acknowledging multiple DATA chunks received 791 * in packets from different source addresses in a single 792 * SACK, the SACK chunk may be transmitted to one of the 793 * destination transport addresses from which the DATA or 794 * control chunks being acknowledged were received. 795 * 796 * [BUG: We do not implement the following paragraph. 797 * Perhaps we should remember the last transport we used for a 798 * SACK and avoid that (if possible) if we have seen any 799 * duplicates. --piggy] 800 * 801 * When a receiver of a duplicate DATA chunk sends a SACK to a 802 * multi- homed endpoint it MAY be beneficial to vary the 803 * destination address and not use the source address of the 804 * DATA chunk. The reason being that receiving a duplicate 805 * from a multi-homed endpoint might indicate that the return 806 * path (as specified in the source address of the DATA chunk) 807 * for the SACK is broken. 808 * 809 * [Send to the address from which we last received a DATA chunk.] 810 */ 811 retval->transport = asoc->peer.last_data_from; 812 813 retval->subh.sack_hdr = 814 sctp_addto_chunk(retval, sizeof(sack), &sack); 815 816 /* Add the gap ack block information. */ 817 if (num_gabs) 818 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, 819 gabs); 820 821 /* Add the duplicate TSN information. */ 822 if (num_dup_tsns) { 823 asoc->stats.idupchunks += num_dup_tsns; 824 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, 825 sctp_tsnmap_get_dups(map)); 826 } 827 /* Once we have a sack generated, check to see what our sack 828 * generation is, if its 0, reset the transports to 0, and reset 829 * the association generation to 1 830 * 831 * The idea is that zero is never used as a valid generation for the 832 * association so no transport will match after a wrap event like this, 833 * Until the next sack 834 */ 835 if (++asoc->peer.sack_generation == 0) { 836 list_for_each_entry(trans, &asoc->peer.transport_addr_list, 837 transports) 838 trans->sack_generation = 0; 839 asoc->peer.sack_generation = 1; 840 } 841nodata: 842 return retval; 843} 844 845/* Make a SHUTDOWN chunk. */ 846struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 847 const struct sctp_chunk *chunk) 848{ 849 struct sctp_shutdownhdr shut; 850 struct sctp_chunk *retval; 851 __u32 ctsn; 852 853 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 854 shut.cum_tsn_ack = htonl(ctsn); 855 856 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0, 857 sizeof(shut), GFP_ATOMIC); 858 if (!retval) 859 goto nodata; 860 861 retval->subh.shutdown_hdr = 862 sctp_addto_chunk(retval, sizeof(shut), &shut); 863 864 if (chunk) 865 retval->transport = chunk->transport; 866nodata: 867 return retval; 868} 869 870struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 871 const struct sctp_chunk *chunk) 872{ 873 struct sctp_chunk *retval; 874 875 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0, 876 GFP_ATOMIC); 877 878 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 879 * 880 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 881 * HEARTBEAT ACK, * etc.) to the same destination transport 882 * address from which it * received the DATA or control chunk 883 * to which it is replying. 884 * 885 * [ACK back to where the SHUTDOWN came from.] 886 */ 887 if (retval && chunk) 888 retval->transport = chunk->transport; 889 890 return retval; 891} 892 893struct sctp_chunk *sctp_make_shutdown_complete( 894 const struct sctp_association *asoc, 895 const struct sctp_chunk *chunk) 896{ 897 struct sctp_chunk *retval; 898 __u8 flags = 0; 899 900 /* Set the T-bit if we have no association (vtag will be 901 * reflected) 902 */ 903 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; 904 905 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 906 0, GFP_ATOMIC); 907 908 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 909 * 910 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 911 * HEARTBEAT ACK, * etc.) to the same destination transport 912 * address from which it * received the DATA or control chunk 913 * to which it is replying. 914 * 915 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK 916 * came from.] 917 */ 918 if (retval && chunk) 919 retval->transport = chunk->transport; 920 921 return retval; 922} 923 924/* Create an ABORT. Note that we set the T bit if we have no 925 * association, except when responding to an INIT (sctpimpguide 2.41). 926 */ 927struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 928 const struct sctp_chunk *chunk, 929 const size_t hint) 930{ 931 struct sctp_chunk *retval; 932 __u8 flags = 0; 933 934 /* Set the T-bit if we have no association and 'chunk' is not 935 * an INIT (vtag will be reflected). 936 */ 937 if (!asoc) { 938 if (chunk && chunk->chunk_hdr && 939 chunk->chunk_hdr->type == SCTP_CID_INIT) 940 flags = 0; 941 else 942 flags = SCTP_CHUNK_FLAG_T; 943 } 944 945 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint, 946 GFP_ATOMIC); 947 948 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 949 * 950 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 951 * HEARTBEAT ACK, * etc.) to the same destination transport 952 * address from which it * received the DATA or control chunk 953 * to which it is replying. 954 * 955 * [ABORT back to where the offender came from.] 956 */ 957 if (retval && chunk) 958 retval->transport = chunk->transport; 959 960 return retval; 961} 962 963/* Helper to create ABORT with a NO_USER_DATA error. */ 964struct sctp_chunk *sctp_make_abort_no_data( 965 const struct sctp_association *asoc, 966 const struct sctp_chunk *chunk, 967 __u32 tsn) 968{ 969 struct sctp_chunk *retval; 970 __be32 payload; 971 972 retval = sctp_make_abort(asoc, chunk, 973 sizeof(struct sctp_errhdr) + sizeof(tsn)); 974 975 if (!retval) 976 goto no_mem; 977 978 /* Put the tsn back into network byte order. */ 979 payload = htonl(tsn); 980 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload)); 981 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload); 982 983 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 984 * 985 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 986 * HEARTBEAT ACK, * etc.) to the same destination transport 987 * address from which it * received the DATA or control chunk 988 * to which it is replying. 989 * 990 * [ABORT back to where the offender came from.] 991 */ 992 if (chunk) 993 retval->transport = chunk->transport; 994 995no_mem: 996 return retval; 997} 998 999/* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ 1000struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 1001 struct msghdr *msg, 1002 size_t paylen) 1003{ 1004 struct sctp_chunk *retval; 1005 void *payload = NULL; 1006 int err; 1007 1008 retval = sctp_make_abort(asoc, NULL, 1009 sizeof(struct sctp_errhdr) + paylen); 1010 if (!retval) 1011 goto err_chunk; 1012 1013 if (paylen) { 1014 /* Put the msg_iov together into payload. */ 1015 payload = kmalloc(paylen, GFP_KERNEL); 1016 if (!payload) 1017 goto err_payload; 1018 1019 err = memcpy_from_msg(payload, msg, paylen); 1020 if (err < 0) 1021 goto err_copy; 1022 } 1023 1024 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); 1025 sctp_addto_chunk(retval, paylen, payload); 1026 1027 if (paylen) 1028 kfree(payload); 1029 1030 return retval; 1031 1032err_copy: 1033 kfree(payload); 1034err_payload: 1035 sctp_chunk_free(retval); 1036 retval = NULL; 1037err_chunk: 1038 return retval; 1039} 1040 1041/* Append bytes to the end of a parameter. Will panic if chunk is not big 1042 * enough. 1043 */ 1044static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 1045 const void *data) 1046{ 1047 int chunklen = ntohs(chunk->chunk_hdr->length); 1048 void *target; 1049 1050 target = skb_put(chunk->skb, len); 1051 1052 if (data) 1053 memcpy(target, data, len); 1054 else 1055 memset(target, 0, len); 1056 1057 /* Adjust the chunk length field. */ 1058 chunk->chunk_hdr->length = htons(chunklen + len); 1059 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1060 1061 return target; 1062} 1063 1064/* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ 1065struct sctp_chunk *sctp_make_abort_violation( 1066 const struct sctp_association *asoc, 1067 const struct sctp_chunk *chunk, 1068 const __u8 *payload, 1069 const size_t paylen) 1070{ 1071 struct sctp_chunk *retval; 1072 struct sctp_paramhdr phdr; 1073 1074 retval = sctp_make_abort(asoc, chunk, sizeof(struct sctp_errhdr) + 1075 paylen + sizeof(phdr)); 1076 if (!retval) 1077 goto end; 1078 1079 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen + 1080 sizeof(phdr)); 1081 1082 phdr.type = htons(chunk->chunk_hdr->type); 1083 phdr.length = chunk->chunk_hdr->length; 1084 sctp_addto_chunk(retval, paylen, payload); 1085 sctp_addto_param(retval, sizeof(phdr), &phdr); 1086 1087end: 1088 return retval; 1089} 1090 1091struct sctp_chunk *sctp_make_violation_paramlen( 1092 const struct sctp_association *asoc, 1093 const struct sctp_chunk *chunk, 1094 struct sctp_paramhdr *param) 1095{ 1096 static const char error[] = "The following parameter had invalid length:"; 1097 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr) + 1098 sizeof(*param); 1099 struct sctp_chunk *retval; 1100 1101 retval = sctp_make_abort(asoc, chunk, payload_len); 1102 if (!retval) 1103 goto nodata; 1104 1105 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, 1106 sizeof(error) + sizeof(*param)); 1107 sctp_addto_chunk(retval, sizeof(error), error); 1108 sctp_addto_param(retval, sizeof(*param), param); 1109 1110nodata: 1111 return retval; 1112} 1113 1114struct sctp_chunk *sctp_make_violation_max_retrans( 1115 const struct sctp_association *asoc, 1116 const struct sctp_chunk *chunk) 1117{ 1118 static const char error[] = "Association exceeded its max_retrans count"; 1119 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr); 1120 struct sctp_chunk *retval; 1121 1122 retval = sctp_make_abort(asoc, chunk, payload_len); 1123 if (!retval) 1124 goto nodata; 1125 1126 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error)); 1127 sctp_addto_chunk(retval, sizeof(error), error); 1128 1129nodata: 1130 return retval; 1131} 1132 1133struct sctp_chunk *sctp_make_new_encap_port(const struct sctp_association *asoc, 1134 const struct sctp_chunk *chunk) 1135{ 1136 struct sctp_new_encap_port_hdr nep; 1137 struct sctp_chunk *retval; 1138 1139 retval = sctp_make_abort(asoc, chunk, 1140 sizeof(struct sctp_errhdr) + sizeof(nep)); 1141 if (!retval) 1142 goto nodata; 1143 1144 sctp_init_cause(retval, SCTP_ERROR_NEW_ENCAP_PORT, sizeof(nep)); 1145 nep.cur_port = SCTP_INPUT_CB(chunk->skb)->encap_port; 1146 nep.new_port = chunk->transport->encap_port; 1147 sctp_addto_chunk(retval, sizeof(nep), &nep); 1148 1149nodata: 1150 return retval; 1151} 1152 1153/* Make a HEARTBEAT chunk. */ 1154struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1155 const struct sctp_transport *transport, 1156 __u32 probe_size) 1157{ 1158 struct sctp_sender_hb_info hbinfo = {}; 1159 struct sctp_chunk *retval; 1160 1161 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, 1162 sizeof(hbinfo), GFP_ATOMIC); 1163 1164 if (!retval) 1165 goto nodata; 1166 1167 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; 1168 hbinfo.param_hdr.length = htons(sizeof(hbinfo)); 1169 hbinfo.daddr = transport->ipaddr; 1170 hbinfo.sent_at = jiffies; 1171 hbinfo.hb_nonce = transport->hb_nonce; 1172 hbinfo.probe_size = probe_size; 1173 1174 /* Cast away the 'const', as this is just telling the chunk 1175 * what transport it belongs to. 1176 */ 1177 retval->transport = (struct sctp_transport *) transport; 1178 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo), 1179 &hbinfo); 1180 retval->pmtu_probe = !!probe_size; 1181 1182nodata: 1183 return retval; 1184} 1185 1186struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1187 const struct sctp_chunk *chunk, 1188 const void *payload, 1189 const size_t paylen) 1190{ 1191 struct sctp_chunk *retval; 1192 1193 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen, 1194 GFP_ATOMIC); 1195 if (!retval) 1196 goto nodata; 1197 1198 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1199 1200 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1201 * 1202 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1203 * HEARTBEAT ACK, * etc.) to the same destination transport 1204 * address from which it * received the DATA or control chunk 1205 * to which it is replying. 1206 * 1207 * [HBACK back to where the HEARTBEAT came from.] 1208 */ 1209 if (chunk) 1210 retval->transport = chunk->transport; 1211 1212nodata: 1213 return retval; 1214} 1215 1216/* RFC4820 3. Padding Chunk (PAD) 1217 * 0 1 2 3 1218 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 1219 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1220 * | Type = 0x84 | Flags=0 | Length | 1221 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1222 * | | 1223 * \ Padding Data / 1224 * / \ 1225 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1226 */ 1227struct sctp_chunk *sctp_make_pad(const struct sctp_association *asoc, int len) 1228{ 1229 struct sctp_chunk *retval; 1230 1231 retval = sctp_make_control(asoc, SCTP_CID_PAD, 0, len, GFP_ATOMIC); 1232 if (!retval) 1233 return NULL; 1234 1235 skb_put_zero(retval->skb, len); 1236 retval->chunk_hdr->length = htons(ntohs(retval->chunk_hdr->length) + len); 1237 retval->chunk_end = skb_tail_pointer(retval->skb); 1238 1239 return retval; 1240} 1241 1242/* Create an Operation Error chunk with the specified space reserved. 1243 * This routine can be used for containing multiple causes in the chunk. 1244 */ 1245static struct sctp_chunk *sctp_make_op_error_space( 1246 const struct sctp_association *asoc, 1247 const struct sctp_chunk *chunk, 1248 size_t size) 1249{ 1250 struct sctp_chunk *retval; 1251 1252 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0, 1253 sizeof(struct sctp_errhdr) + size, 1254 GFP_ATOMIC); 1255 if (!retval) 1256 goto nodata; 1257 1258 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1259 * 1260 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1261 * HEARTBEAT ACK, etc.) to the same destination transport 1262 * address from which it received the DATA or control chunk 1263 * to which it is replying. 1264 * 1265 */ 1266 if (chunk) 1267 retval->transport = chunk->transport; 1268 1269nodata: 1270 return retval; 1271} 1272 1273/* Create an Operation Error chunk of a fixed size, specifically, 1274 * min(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) - overheads. 1275 * This is a helper function to allocate an error chunk for those 1276 * invalid parameter codes in which we may not want to report all the 1277 * errors, if the incoming chunk is large. If it can't fit in a single 1278 * packet, we ignore it. 1279 */ 1280static inline struct sctp_chunk *sctp_make_op_error_limited( 1281 const struct sctp_association *asoc, 1282 const struct sctp_chunk *chunk) 1283{ 1284 size_t size = SCTP_DEFAULT_MAXSEGMENT; 1285 struct sctp_sock *sp = NULL; 1286 1287 if (asoc) { 1288 size = min_t(size_t, size, asoc->pathmtu); 1289 sp = sctp_sk(asoc->base.sk); 1290 } 1291 1292 size = sctp_mtu_payload(sp, size, sizeof(struct sctp_errhdr)); 1293 1294 return sctp_make_op_error_space(asoc, chunk, size); 1295} 1296 1297/* Create an Operation Error chunk. */ 1298struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1299 const struct sctp_chunk *chunk, 1300 __be16 cause_code, const void *payload, 1301 size_t paylen, size_t reserve_tail) 1302{ 1303 struct sctp_chunk *retval; 1304 1305 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); 1306 if (!retval) 1307 goto nodata; 1308 1309 sctp_init_cause(retval, cause_code, paylen + reserve_tail); 1310 sctp_addto_chunk(retval, paylen, payload); 1311 if (reserve_tail) 1312 sctp_addto_param(retval, reserve_tail, NULL); 1313 1314nodata: 1315 return retval; 1316} 1317 1318struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc, 1319 __u16 key_id) 1320{ 1321 struct sctp_authhdr auth_hdr; 1322 const struct sctp_hmac *hmac_desc; 1323 struct sctp_chunk *retval; 1324 1325 /* Get the first hmac that the peer told us to use */ 1326 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1327 if (unlikely(!hmac_desc)) 1328 return NULL; 1329 1330 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0, 1331 hmac_desc->hmac_len + sizeof(auth_hdr), 1332 GFP_ATOMIC); 1333 if (!retval) 1334 return NULL; 1335 1336 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1337 auth_hdr.shkey_id = htons(key_id); 1338 1339 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr), 1340 &auth_hdr); 1341 1342 skb_put_zero(retval->skb, hmac_desc->hmac_len); 1343 1344 /* Adjust the chunk header to include the empty MAC */ 1345 retval->chunk_hdr->length = 1346 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1347 retval->chunk_end = skb_tail_pointer(retval->skb); 1348 1349 return retval; 1350} 1351 1352 1353/******************************************************************** 1354 * 2nd Level Abstractions 1355 ********************************************************************/ 1356 1357/* Turn an skb into a chunk. 1358 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1359 * 1360 * sctpimpguide-05.txt Section 2.8.2 1361 * M1) Each time a new DATA chunk is transmitted 1362 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1363 * 'TSN.Missing.Report' count will be used to determine missing chunks 1364 * and when to fast retransmit. 1365 * 1366 */ 1367struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1368 const struct sctp_association *asoc, 1369 struct sock *sk, gfp_t gfp) 1370{ 1371 struct sctp_chunk *retval; 1372 1373 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp); 1374 1375 if (!retval) 1376 goto nodata; 1377 if (!sk) 1378 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb); 1379 1380 INIT_LIST_HEAD(&retval->list); 1381 retval->skb = skb; 1382 retval->asoc = (struct sctp_association *)asoc; 1383 retval->singleton = 1; 1384 1385 retval->fast_retransmit = SCTP_CAN_FRTX; 1386 1387 /* Polish the bead hole. */ 1388 INIT_LIST_HEAD(&retval->transmitted_list); 1389 INIT_LIST_HEAD(&retval->frag_list); 1390 SCTP_DBG_OBJCNT_INC(chunk); 1391 refcount_set(&retval->refcnt, 1); 1392 1393nodata: 1394 return retval; 1395} 1396 1397/* Set chunk->source and dest based on the IP header in chunk->skb. */ 1398void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1399 union sctp_addr *dest) 1400{ 1401 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1402 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1403} 1404 1405/* Extract the source address from a chunk. */ 1406const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1407{ 1408 /* If we have a known transport, use that. */ 1409 if (chunk->transport) { 1410 return &chunk->transport->ipaddr; 1411 } else { 1412 /* Otherwise, extract it from the IP header. */ 1413 return &chunk->source; 1414 } 1415} 1416 1417/* Create a new chunk, setting the type and flags headers from the 1418 * arguments, reserving enough space for a 'paylen' byte payload. 1419 */ 1420static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 1421 __u8 type, __u8 flags, int paylen, 1422 gfp_t gfp) 1423{ 1424 struct sctp_chunkhdr *chunk_hdr; 1425 struct sctp_chunk *retval; 1426 struct sk_buff *skb; 1427 struct sock *sk; 1428 int chunklen; 1429 1430 chunklen = SCTP_PAD4(sizeof(*chunk_hdr) + paylen); 1431 if (chunklen > SCTP_MAX_CHUNK_LEN) 1432 goto nodata; 1433 1434 /* No need to allocate LL here, as this is only a chunk. */ 1435 skb = alloc_skb(chunklen, gfp); 1436 if (!skb) 1437 goto nodata; 1438 1439 /* Make room for the chunk header. */ 1440 chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr)); 1441 chunk_hdr->type = type; 1442 chunk_hdr->flags = flags; 1443 chunk_hdr->length = htons(sizeof(*chunk_hdr)); 1444 1445 sk = asoc ? asoc->base.sk : NULL; 1446 retval = sctp_chunkify(skb, asoc, sk, gfp); 1447 if (!retval) { 1448 kfree_skb(skb); 1449 goto nodata; 1450 } 1451 1452 retval->chunk_hdr = chunk_hdr; 1453 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr); 1454 1455 /* Determine if the chunk needs to be authenticated */ 1456 if (sctp_auth_send_cid(type, asoc)) 1457 retval->auth = 1; 1458 1459 return retval; 1460nodata: 1461 return NULL; 1462} 1463 1464static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 1465 __u8 flags, int paylen, gfp_t gfp) 1466{ 1467 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp); 1468} 1469 1470struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc, 1471 __u8 flags, int paylen, gfp_t gfp) 1472{ 1473 return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp); 1474} 1475 1476static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 1477 __u8 type, __u8 flags, int paylen, 1478 gfp_t gfp) 1479{ 1480 struct sctp_chunk *chunk; 1481 1482 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp); 1483 if (chunk) 1484 sctp_control_set_owner_w(chunk); 1485 1486 return chunk; 1487} 1488 1489/* Release the memory occupied by a chunk. */ 1490static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1491{ 1492 BUG_ON(!list_empty(&chunk->list)); 1493 list_del_init(&chunk->transmitted_list); 1494 1495 consume_skb(chunk->skb); 1496 consume_skb(chunk->auth_chunk); 1497 1498 SCTP_DBG_OBJCNT_DEC(chunk); 1499 kmem_cache_free(sctp_chunk_cachep, chunk); 1500} 1501 1502/* Possibly, free the chunk. */ 1503void sctp_chunk_free(struct sctp_chunk *chunk) 1504{ 1505 /* Release our reference on the message tracker. */ 1506 if (chunk->msg) 1507 sctp_datamsg_put(chunk->msg); 1508 1509 sctp_chunk_put(chunk); 1510} 1511 1512/* Grab a reference to the chunk. */ 1513void sctp_chunk_hold(struct sctp_chunk *ch) 1514{ 1515 refcount_inc(&ch->refcnt); 1516} 1517 1518/* Release a reference to the chunk. */ 1519void sctp_chunk_put(struct sctp_chunk *ch) 1520{ 1521 if (refcount_dec_and_test(&ch->refcnt)) 1522 sctp_chunk_destroy(ch); 1523} 1524 1525/* Append bytes to the end of a chunk. Will panic if chunk is not big 1526 * enough. 1527 */ 1528void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1529{ 1530 int chunklen = ntohs(chunk->chunk_hdr->length); 1531 int padlen = SCTP_PAD4(chunklen) - chunklen; 1532 void *target; 1533 1534 skb_put_zero(chunk->skb, padlen); 1535 target = skb_put_data(chunk->skb, data, len); 1536 1537 /* Adjust the chunk length field. */ 1538 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1539 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1540 1541 return target; 1542} 1543 1544/* Append bytes from user space to the end of a chunk. Will panic if 1545 * chunk is not big enough. 1546 * Returns a kernel err value. 1547 */ 1548int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len, 1549 struct iov_iter *from) 1550{ 1551 void *target; 1552 1553 /* Make room in chunk for data. */ 1554 target = skb_put(chunk->skb, len); 1555 1556 /* Copy data (whole iovec) into chunk */ 1557 if (!copy_from_iter_full(target, len, from)) 1558 return -EFAULT; 1559 1560 /* Adjust the chunk length field. */ 1561 chunk->chunk_hdr->length = 1562 htons(ntohs(chunk->chunk_hdr->length) + len); 1563 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1564 1565 return 0; 1566} 1567 1568/* Helper function to assign a TSN if needed. This assumes that both 1569 * the data_hdr and association have already been assigned. 1570 */ 1571void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1572{ 1573 struct sctp_stream *stream; 1574 struct sctp_chunk *lchunk; 1575 struct sctp_datamsg *msg; 1576 __u16 ssn, sid; 1577 1578 if (chunk->has_ssn) 1579 return; 1580 1581 /* All fragments will be on the same stream */ 1582 sid = ntohs(chunk->subh.data_hdr->stream); 1583 stream = &chunk->asoc->stream; 1584 1585 /* Now assign the sequence number to the entire message. 1586 * All fragments must have the same stream sequence number. 1587 */ 1588 msg = chunk->msg; 1589 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1590 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1591 ssn = 0; 1592 } else { 1593 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1594 ssn = sctp_ssn_next(stream, out, sid); 1595 else 1596 ssn = sctp_ssn_peek(stream, out, sid); 1597 } 1598 1599 lchunk->subh.data_hdr->ssn = htons(ssn); 1600 lchunk->has_ssn = 1; 1601 } 1602} 1603 1604/* Helper function to assign a TSN if needed. This assumes that both 1605 * the data_hdr and association have already been assigned. 1606 */ 1607void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1608{ 1609 if (!chunk->has_tsn) { 1610 /* This is the last possible instant to 1611 * assign a TSN. 1612 */ 1613 chunk->subh.data_hdr->tsn = 1614 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1615 chunk->has_tsn = 1; 1616 } 1617} 1618 1619/* Create a CLOSED association to use with an incoming packet. */ 1620struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1621 struct sctp_chunk *chunk, 1622 gfp_t gfp) 1623{ 1624 struct sctp_association *asoc; 1625 enum sctp_scope scope; 1626 struct sk_buff *skb; 1627 1628 /* Create the bare association. */ 1629 scope = sctp_scope(sctp_source(chunk)); 1630 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1631 if (!asoc) 1632 goto nodata; 1633 asoc->temp = 1; 1634 skb = chunk->skb; 1635 /* Create an entry for the source address of the packet. */ 1636 SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1); 1637 1638nodata: 1639 return asoc; 1640} 1641 1642/* Build a cookie representing asoc. 1643 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1644 */ 1645static struct sctp_cookie_param *sctp_pack_cookie( 1646 const struct sctp_endpoint *ep, 1647 const struct sctp_association *asoc, 1648 const struct sctp_chunk *init_chunk, 1649 int *cookie_len, const __u8 *raw_addrs, 1650 int addrs_len) 1651{ 1652 struct sctp_signed_cookie *cookie; 1653 struct sctp_cookie_param *retval; 1654 int headersize, bodysize; 1655 1656 /* Header size is static data prior to the actual cookie, including 1657 * any padding. 1658 */ 1659 headersize = sizeof(struct sctp_paramhdr) + 1660 (sizeof(struct sctp_signed_cookie) - 1661 sizeof(struct sctp_cookie)); 1662 bodysize = sizeof(struct sctp_cookie) 1663 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1664 1665 /* Pad out the cookie to a multiple to make the signature 1666 * functions simpler to write. 1667 */ 1668 if (bodysize % SCTP_COOKIE_MULTIPLE) 1669 bodysize += SCTP_COOKIE_MULTIPLE 1670 - (bodysize % SCTP_COOKIE_MULTIPLE); 1671 *cookie_len = headersize + bodysize; 1672 1673 /* Clear this memory since we are sending this data structure 1674 * out on the network. 1675 */ 1676 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1677 if (!retval) { 1678 *cookie_len = 0; 1679 return NULL; 1680 } 1681 1682 cookie = (struct sctp_signed_cookie *) retval->body; 1683 1684 /* Set up the parameter header. */ 1685 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1686 retval->p.length = htons(*cookie_len); 1687 1688 /* Copy the cookie part of the association itself. */ 1689 cookie->c = asoc->c; 1690 /* Save the raw address list length in the cookie. */ 1691 cookie->c.raw_addr_list_len = addrs_len; 1692 1693 /* Remember PR-SCTP capability. */ 1694 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1695 1696 /* Save adaptation indication in the cookie. */ 1697 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1698 1699 /* Set an expiration time for the cookie. */ 1700 cookie->c.expiration = ktime_add(asoc->cookie_life, 1701 ktime_get_real()); 1702 1703 /* Copy the peer's init packet. */ 1704 memcpy(cookie + 1, init_chunk->chunk_hdr, 1705 ntohs(init_chunk->chunk_hdr->length)); 1706 1707 /* Copy the raw local address list of the association. */ 1708 memcpy((__u8 *)(cookie + 1) + 1709 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1710 1711 /* Sign the cookie, if cookie authentication is enabled. */ 1712 if (sctp_sk(ep->base.sk)->cookie_auth_enable) { 1713 static_assert(sizeof(cookie->mac) == SHA256_DIGEST_SIZE); 1714 hmac_sha256(&ep->cookie_auth_key, (const u8 *)&cookie->c, 1715 bodysize, cookie->mac); 1716 } 1717 1718 return retval; 1719} 1720 1721/* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1722struct sctp_association *sctp_unpack_cookie( 1723 const struct sctp_endpoint *ep, 1724 const struct sctp_association *asoc, 1725 struct sctp_chunk *chunk, gfp_t gfp, 1726 int *error, struct sctp_chunk **errp) 1727{ 1728 struct sctp_association *retval = NULL; 1729 int headersize, bodysize, fixed_size; 1730 struct sctp_signed_cookie *cookie; 1731 struct sk_buff *skb = chunk->skb; 1732 struct sctp_cookie *bear_cookie; 1733 enum sctp_scope scope; 1734 unsigned int len; 1735 ktime_t kt; 1736 1737 /* Header size is static data prior to the actual cookie, including 1738 * any padding. 1739 */ 1740 headersize = sizeof(struct sctp_chunkhdr) + 1741 (sizeof(struct sctp_signed_cookie) - 1742 sizeof(struct sctp_cookie)); 1743 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1744 fixed_size = headersize + sizeof(struct sctp_cookie); 1745 1746 /* Verify that the chunk looks like it even has a cookie. 1747 * There must be enough room for our cookie and our peer's 1748 * INIT chunk. 1749 */ 1750 len = ntohs(chunk->chunk_hdr->length); 1751 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1752 goto malformed; 1753 1754 /* Verify that the cookie has been padded out. */ 1755 if (bodysize % SCTP_COOKIE_MULTIPLE) 1756 goto malformed; 1757 1758 /* Process the cookie. */ 1759 cookie = chunk->subh.cookie_hdr; 1760 bear_cookie = &cookie->c; 1761 1762 /* Verify the cookie's MAC, if cookie authentication is enabled. */ 1763 if (sctp_sk(ep->base.sk)->cookie_auth_enable) { 1764 u8 mac[SHA256_DIGEST_SIZE]; 1765 1766 hmac_sha256(&ep->cookie_auth_key, (const u8 *)bear_cookie, 1767 bodysize, mac); 1768 static_assert(sizeof(cookie->mac) == sizeof(mac)); 1769 if (crypto_memneq(mac, cookie->mac, sizeof(mac))) { 1770 *error = -SCTP_IERROR_BAD_SIG; 1771 goto fail; 1772 } 1773 } 1774 1775 /* IG Section 2.35.2: 1776 * 3) Compare the port numbers and the verification tag contained 1777 * within the COOKIE ECHO chunk to the actual port numbers and the 1778 * verification tag within the SCTP common header of the received 1779 * packet. If these values do not match the packet MUST be silently 1780 * discarded, 1781 */ 1782 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1783 *error = -SCTP_IERROR_BAD_TAG; 1784 goto fail; 1785 } 1786 1787 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1788 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1789 *error = -SCTP_IERROR_BAD_PORTS; 1790 goto fail; 1791 } 1792 1793 /* Check to see if the cookie is stale. If there is already 1794 * an association, there is no need to check cookie's expiration 1795 * for init collision case of lost COOKIE ACK. 1796 * If skb has been timestamped, then use the stamp, otherwise 1797 * use current time. This introduces a small possibility that 1798 * a cookie may be considered expired, but this would only slow 1799 * down the new association establishment instead of every packet. 1800 */ 1801 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1802 kt = skb_get_ktime(skb); 1803 else 1804 kt = ktime_get_real(); 1805 1806 if (!asoc && ktime_before(bear_cookie->expiration, kt)) { 1807 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); 1808 __be32 n = htonl(usecs); 1809 1810 /* 1811 * Section 3.3.10.3 Stale Cookie Error (3) 1812 * 1813 * Cause of error 1814 * --------------- 1815 * Stale Cookie Error: Indicates the receipt of a valid State 1816 * Cookie that has expired. 1817 */ 1818 *errp = sctp_make_op_error(asoc, chunk, 1819 SCTP_ERROR_STALE_COOKIE, &n, 1820 sizeof(n), 0); 1821 if (*errp) 1822 *error = -SCTP_IERROR_STALE_COOKIE; 1823 else 1824 *error = -SCTP_IERROR_NOMEM; 1825 1826 goto fail; 1827 } 1828 1829 /* Make a new base association. */ 1830 scope = sctp_scope(sctp_source(chunk)); 1831 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1832 if (!retval) { 1833 *error = -SCTP_IERROR_NOMEM; 1834 goto fail; 1835 } 1836 1837 /* Set up our peer's port number. */ 1838 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1839 1840 /* Populate the association from the cookie. */ 1841 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1842 1843 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1844 GFP_ATOMIC) < 0) { 1845 *error = -SCTP_IERROR_NOMEM; 1846 goto fail; 1847 } 1848 1849 /* Also, add the destination address. */ 1850 if (list_empty(&retval->base.bind_addr.address_list)) { 1851 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1852 sizeof(chunk->dest), SCTP_ADDR_SRC, 1853 GFP_ATOMIC); 1854 } 1855 1856 retval->next_tsn = retval->c.initial_tsn; 1857 retval->ctsn_ack_point = retval->next_tsn - 1; 1858 retval->addip_serial = retval->c.initial_tsn; 1859 retval->strreset_outseq = retval->c.initial_tsn; 1860 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1861 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1862 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1863 1864 /* The INIT stuff will be done by the side effects. */ 1865 return retval; 1866 1867fail: 1868 if (retval) 1869 sctp_association_free(retval); 1870 1871 return NULL; 1872 1873malformed: 1874 /* Yikes! The packet is either corrupt or deliberately 1875 * malformed. 1876 */ 1877 *error = -SCTP_IERROR_MALFORMED; 1878 goto fail; 1879} 1880 1881/******************************************************************** 1882 * 3rd Level Abstractions 1883 ********************************************************************/ 1884 1885struct __sctp_missing { 1886 __be32 num_missing; 1887 __be16 type; 1888} __packed; 1889 1890/* 1891 * Report a missing mandatory parameter. 1892 */ 1893static int sctp_process_missing_param(const struct sctp_association *asoc, 1894 enum sctp_param paramtype, 1895 struct sctp_chunk *chunk, 1896 struct sctp_chunk **errp) 1897{ 1898 struct __sctp_missing report; 1899 __u16 len; 1900 1901 len = SCTP_PAD4(sizeof(report)); 1902 1903 /* Make an ERROR chunk, preparing enough room for 1904 * returning multiple unknown parameters. 1905 */ 1906 if (!*errp) 1907 *errp = sctp_make_op_error_space(asoc, chunk, len); 1908 1909 if (*errp) { 1910 report.num_missing = htonl(1); 1911 report.type = paramtype; 1912 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1913 sizeof(report)); 1914 sctp_addto_chunk(*errp, sizeof(report), &report); 1915 } 1916 1917 /* Stop processing this chunk. */ 1918 return 0; 1919} 1920 1921/* Report an Invalid Mandatory Parameter. */ 1922static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1923 struct sctp_chunk *chunk, 1924 struct sctp_chunk **errp) 1925{ 1926 /* Invalid Mandatory Parameter Error has no payload. */ 1927 1928 if (!*errp) 1929 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1930 1931 if (*errp) 1932 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1933 1934 /* Stop processing this chunk. */ 1935 return 0; 1936} 1937 1938static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1939 struct sctp_paramhdr *param, 1940 const struct sctp_chunk *chunk, 1941 struct sctp_chunk **errp) 1942{ 1943 /* This is a fatal error. Any accumulated non-fatal errors are 1944 * not reported. 1945 */ 1946 if (*errp) 1947 sctp_chunk_free(*errp); 1948 1949 /* Create an error chunk and fill it in with our payload. */ 1950 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1951 1952 return 0; 1953} 1954 1955 1956/* Do not attempt to handle the HOST_NAME parm. However, do 1957 * send back an indicator to the peer. 1958 */ 1959static int sctp_process_hn_param(const struct sctp_association *asoc, 1960 union sctp_params param, 1961 struct sctp_chunk *chunk, 1962 struct sctp_chunk **errp) 1963{ 1964 __u16 len = ntohs(param.p->length); 1965 1966 /* Processing of the HOST_NAME parameter will generate an 1967 * ABORT. If we've accumulated any non-fatal errors, they 1968 * would be unrecognized parameters and we should not include 1969 * them in the ABORT. 1970 */ 1971 if (*errp) 1972 sctp_chunk_free(*errp); 1973 1974 *errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_DNS_FAILED, 1975 param.v, len, 0); 1976 1977 /* Stop processing this chunk. */ 1978 return 0; 1979} 1980 1981static int sctp_verify_ext_param(struct net *net, 1982 const struct sctp_endpoint *ep, 1983 union sctp_params param) 1984{ 1985 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 1986 int have_asconf = 0; 1987 int have_auth = 0; 1988 int i; 1989 1990 for (i = 0; i < num_ext; i++) { 1991 switch (param.ext->chunks[i]) { 1992 case SCTP_CID_AUTH: 1993 have_auth = 1; 1994 break; 1995 case SCTP_CID_ASCONF: 1996 case SCTP_CID_ASCONF_ACK: 1997 have_asconf = 1; 1998 break; 1999 } 2000 } 2001 2002 /* ADD-IP Security: The draft requires us to ABORT or ignore the 2003 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 2004 * only if ADD-IP is turned on and we are not backward-compatible 2005 * mode. 2006 */ 2007 if (net->sctp.addip_noauth) 2008 return 1; 2009 2010 if (ep->asconf_enable && !have_auth && have_asconf) 2011 return 0; 2012 2013 return 1; 2014} 2015 2016static void sctp_process_ext_param(struct sctp_association *asoc, 2017 union sctp_params param) 2018{ 2019 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2020 int i; 2021 2022 for (i = 0; i < num_ext; i++) { 2023 switch (param.ext->chunks[i]) { 2024 case SCTP_CID_RECONF: 2025 if (asoc->ep->reconf_enable) 2026 asoc->peer.reconf_capable = 1; 2027 break; 2028 case SCTP_CID_FWD_TSN: 2029 if (asoc->ep->prsctp_enable) 2030 asoc->peer.prsctp_capable = 1; 2031 break; 2032 case SCTP_CID_AUTH: 2033 /* if the peer reports AUTH, assume that he 2034 * supports AUTH. 2035 */ 2036 if (asoc->ep->auth_enable) 2037 asoc->peer.auth_capable = 1; 2038 break; 2039 case SCTP_CID_ASCONF: 2040 case SCTP_CID_ASCONF_ACK: 2041 if (asoc->ep->asconf_enable) 2042 asoc->peer.asconf_capable = 1; 2043 break; 2044 case SCTP_CID_I_DATA: 2045 if (asoc->ep->intl_enable) 2046 asoc->peer.intl_capable = 1; 2047 break; 2048 default: 2049 break; 2050 } 2051 } 2052} 2053 2054/* RFC 3.2.1 & the Implementers Guide 2.2. 2055 * 2056 * The Parameter Types are encoded such that the 2057 * highest-order two bits specify the action that must be 2058 * taken if the processing endpoint does not recognize the 2059 * Parameter Type. 2060 * 2061 * 00 - Stop processing this parameter; do not process any further 2062 * parameters within this chunk 2063 * 2064 * 01 - Stop processing this parameter, do not process any further 2065 * parameters within this chunk, and report the unrecognized 2066 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2067 * 2068 * 10 - Skip this parameter and continue processing. 2069 * 2070 * 11 - Skip this parameter and continue processing but 2071 * report the unrecognized parameter in an 2072 * 'Unrecognized Parameter' ERROR chunk. 2073 * 2074 * Return value: 2075 * SCTP_IERROR_NO_ERROR - continue with the chunk 2076 * SCTP_IERROR_ERROR - stop and report an error. 2077 * SCTP_IERROR_NOMEME - out of memory. 2078 */ 2079static enum sctp_ierror sctp_process_unk_param( 2080 const struct sctp_association *asoc, 2081 union sctp_params param, 2082 struct sctp_chunk *chunk, 2083 struct sctp_chunk **errp) 2084{ 2085 int retval = SCTP_IERROR_NO_ERROR; 2086 2087 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2088 case SCTP_PARAM_ACTION_DISCARD: 2089 retval = SCTP_IERROR_ERROR; 2090 break; 2091 case SCTP_PARAM_ACTION_SKIP: 2092 break; 2093 case SCTP_PARAM_ACTION_DISCARD_ERR: 2094 retval = SCTP_IERROR_ERROR; 2095 fallthrough; 2096 case SCTP_PARAM_ACTION_SKIP_ERR: 2097 /* Make an ERROR chunk, preparing enough room for 2098 * returning multiple unknown parameters. 2099 */ 2100 if (!*errp) { 2101 *errp = sctp_make_op_error_limited(asoc, chunk); 2102 if (!*errp) { 2103 /* If there is no memory for generating the 2104 * ERROR report as specified, an ABORT will be 2105 * triggered to the peer and the association 2106 * won't be established. 2107 */ 2108 retval = SCTP_IERROR_NOMEM; 2109 break; 2110 } 2111 } 2112 2113 if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2114 ntohs(param.p->length))) 2115 sctp_addto_chunk(*errp, ntohs(param.p->length), 2116 param.v); 2117 break; 2118 default: 2119 break; 2120 } 2121 2122 return retval; 2123} 2124 2125/* Verify variable length parameters 2126 * Return values: 2127 * SCTP_IERROR_ABORT - trigger an ABORT 2128 * SCTP_IERROR_NOMEM - out of memory (abort) 2129 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2130 * SCTP_IERROR_NO_ERROR - continue with the chunk 2131 */ 2132static enum sctp_ierror sctp_verify_param(struct net *net, 2133 const struct sctp_endpoint *ep, 2134 const struct sctp_association *asoc, 2135 union sctp_params param, 2136 enum sctp_cid cid, 2137 struct sctp_chunk *chunk, 2138 struct sctp_chunk **err_chunk) 2139{ 2140 struct sctp_hmac_algo_param *hmacs; 2141 int retval = SCTP_IERROR_NO_ERROR; 2142 __u16 n_elt, id = 0; 2143 int i; 2144 2145 /* FIXME - This routine is not looking at each parameter per the 2146 * chunk type, i.e., unrecognized parameters should be further 2147 * identified based on the chunk id. 2148 */ 2149 2150 switch (param.p->type) { 2151 case SCTP_PARAM_IPV4_ADDRESS: 2152 case SCTP_PARAM_IPV6_ADDRESS: 2153 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2154 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2155 case SCTP_PARAM_STATE_COOKIE: 2156 case SCTP_PARAM_HEARTBEAT_INFO: 2157 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2158 case SCTP_PARAM_ECN_CAPABLE: 2159 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2160 break; 2161 2162 case SCTP_PARAM_SUPPORTED_EXT: 2163 if (!sctp_verify_ext_param(net, ep, param)) 2164 return SCTP_IERROR_ABORT; 2165 break; 2166 2167 case SCTP_PARAM_SET_PRIMARY: 2168 if (!ep->asconf_enable) 2169 goto unhandled; 2170 2171 if (ntohs(param.p->length) < sizeof(struct sctp_addip_param) + 2172 sizeof(struct sctp_paramhdr)) { 2173 sctp_process_inv_paramlength(asoc, param.p, 2174 chunk, err_chunk); 2175 retval = SCTP_IERROR_ABORT; 2176 } 2177 break; 2178 2179 case SCTP_PARAM_HOST_NAME_ADDRESS: 2180 /* This param has been Deprecated, send ABORT. */ 2181 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2182 retval = SCTP_IERROR_ABORT; 2183 break; 2184 2185 case SCTP_PARAM_FWD_TSN_SUPPORT: 2186 if (ep->prsctp_enable) 2187 break; 2188 goto unhandled; 2189 2190 case SCTP_PARAM_RANDOM: 2191 if (!ep->auth_enable) 2192 goto unhandled; 2193 2194 /* SCTP-AUTH: Secion 6.1 2195 * If the random number is not 32 byte long the association 2196 * MUST be aborted. The ABORT chunk SHOULD contain the error 2197 * cause 'Protocol Violation'. 2198 */ 2199 if (SCTP_AUTH_RANDOM_LENGTH != ntohs(param.p->length) - 2200 sizeof(struct sctp_paramhdr)) { 2201 sctp_process_inv_paramlength(asoc, param.p, 2202 chunk, err_chunk); 2203 retval = SCTP_IERROR_ABORT; 2204 } 2205 break; 2206 2207 case SCTP_PARAM_CHUNKS: 2208 if (!ep->auth_enable) 2209 goto unhandled; 2210 2211 /* SCTP-AUTH: Section 3.2 2212 * The CHUNKS parameter MUST be included once in the INIT or 2213 * INIT-ACK chunk if the sender wants to receive authenticated 2214 * chunks. Its maximum length is 260 bytes. 2215 */ 2216 if (260 < ntohs(param.p->length)) { 2217 sctp_process_inv_paramlength(asoc, param.p, 2218 chunk, err_chunk); 2219 retval = SCTP_IERROR_ABORT; 2220 } 2221 break; 2222 2223 case SCTP_PARAM_HMAC_ALGO: 2224 if (!ep->auth_enable) 2225 goto unhandled; 2226 2227 hmacs = (struct sctp_hmac_algo_param *)param.p; 2228 n_elt = (ntohs(param.p->length) - 2229 sizeof(struct sctp_paramhdr)) >> 1; 2230 2231 /* SCTP-AUTH: Section 6.1 2232 * The HMAC algorithm based on SHA-1 MUST be supported and 2233 * included in the HMAC-ALGO parameter. 2234 */ 2235 for (i = 0; i < n_elt; i++) { 2236 id = ntohs(hmacs->hmac_ids[i]); 2237 2238 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2239 break; 2240 } 2241 2242 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2243 sctp_process_inv_paramlength(asoc, param.p, chunk, 2244 err_chunk); 2245 retval = SCTP_IERROR_ABORT; 2246 } 2247 break; 2248unhandled: 2249 default: 2250 pr_debug("%s: unrecognized param:%d for chunk:%d\n", 2251 __func__, ntohs(param.p->type), cid); 2252 2253 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2254 break; 2255 } 2256 return retval; 2257} 2258 2259/* Verify the INIT packet before we process it. */ 2260int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 2261 const struct sctp_association *asoc, enum sctp_cid cid, 2262 struct sctp_init_chunk *peer_init, 2263 struct sctp_chunk *chunk, struct sctp_chunk **errp) 2264{ 2265 union sctp_params param; 2266 bool has_cookie = false; 2267 int result; 2268 2269 /* Check for missing mandatory parameters. Note: Initial TSN is 2270 * also mandatory, but is not checked here since the valid range 2271 * is 0..2**32-1. RFC4960, section 3.3.3. 2272 */ 2273 if (peer_init->init_hdr.num_outbound_streams == 0 || 2274 peer_init->init_hdr.num_inbound_streams == 0 || 2275 peer_init->init_hdr.init_tag == 0 || 2276 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) 2277 return sctp_process_inv_mandatory(asoc, chunk, errp); 2278 2279 sctp_walk_params(param, peer_init) { 2280 if (param.p->type == SCTP_PARAM_STATE_COOKIE) 2281 has_cookie = true; 2282 } 2283 2284 /* There is a possibility that a parameter length was bad and 2285 * in that case we would have stoped walking the parameters. 2286 * The current param.p would point at the bad one. 2287 * Current consensus on the mailing list is to generate a PROTOCOL 2288 * VIOLATION error. We build the ERROR chunk here and let the normal 2289 * error handling code build and send the packet. 2290 */ 2291 if (param.v != (void *)chunk->chunk_end) 2292 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2293 2294 /* The only missing mandatory param possible today is 2295 * the state cookie for an INIT-ACK chunk. 2296 */ 2297 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2298 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2299 chunk, errp); 2300 2301 /* Verify all the variable length parameters */ 2302 sctp_walk_params(param, peer_init) { 2303 result = sctp_verify_param(net, ep, asoc, param, cid, 2304 chunk, errp); 2305 switch (result) { 2306 case SCTP_IERROR_ABORT: 2307 case SCTP_IERROR_NOMEM: 2308 return 0; 2309 case SCTP_IERROR_ERROR: 2310 return 1; 2311 case SCTP_IERROR_NO_ERROR: 2312 default: 2313 break; 2314 } 2315 2316 } /* for (loop through all parameters) */ 2317 2318 return 1; 2319} 2320 2321/* Unpack the parameters in an INIT packet into an association. 2322 * Returns 0 on failure, else success. 2323 * FIXME: This is an association method. 2324 */ 2325int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2326 const union sctp_addr *peer_addr, 2327 struct sctp_init_chunk *peer_init, gfp_t gfp) 2328{ 2329 struct sctp_transport *transport; 2330 struct list_head *pos, *temp; 2331 union sctp_params param; 2332 union sctp_addr addr; 2333 struct sctp_af *af; 2334 int src_match = 0; 2335 2336 /* We must include the address that the INIT packet came from. 2337 * This is the only address that matters for an INIT packet. 2338 * When processing a COOKIE ECHO, we retrieve the from address 2339 * of the INIT from the cookie. 2340 */ 2341 2342 /* This implementation defaults to making the first transport 2343 * added as the primary transport. The source address seems to 2344 * be a better choice than any of the embedded addresses. 2345 */ 2346 asoc->encap_port = SCTP_INPUT_CB(chunk->skb)->encap_port; 2347 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2348 goto nomem; 2349 2350 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2351 src_match = 1; 2352 2353 /* Process the initialization parameters. */ 2354 sctp_walk_params(param, peer_init) { 2355 if (!src_match && 2356 (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2357 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2358 af = sctp_get_af_specific(param_type2af(param.p->type)); 2359 if (!af->from_addr_param(&addr, param.addr, 2360 chunk->sctp_hdr->source, 0)) 2361 continue; 2362 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2363 src_match = 1; 2364 } 2365 2366 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2367 goto clean_up; 2368 } 2369 2370 /* source address of chunk may not match any valid address */ 2371 if (!src_match) 2372 goto clean_up; 2373 2374 /* AUTH: After processing the parameters, make sure that we 2375 * have all the required info to potentially do authentications. 2376 */ 2377 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2378 !asoc->peer.peer_hmacs)) 2379 asoc->peer.auth_capable = 0; 2380 2381 /* In a non-backward compatible mode, if the peer claims 2382 * support for ADD-IP but not AUTH, the ADD-IP spec states 2383 * that we MUST ABORT the association. Section 6. The section 2384 * also give us an option to silently ignore the packet, which 2385 * is what we'll do here. 2386 */ 2387 if (!asoc->base.net->sctp.addip_noauth && 2388 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2389 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2390 SCTP_PARAM_DEL_IP | 2391 SCTP_PARAM_SET_PRIMARY); 2392 asoc->peer.asconf_capable = 0; 2393 goto clean_up; 2394 } 2395 2396 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2397 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2398 transport = list_entry(pos, struct sctp_transport, transports); 2399 if (transport->state == SCTP_UNKNOWN) { 2400 sctp_assoc_rm_peer(asoc, transport); 2401 } 2402 } 2403 2404 /* The fixed INIT headers are always in network byte 2405 * order. 2406 */ 2407 asoc->peer.i.init_tag = 2408 ntohl(peer_init->init_hdr.init_tag); 2409 asoc->peer.i.a_rwnd = 2410 ntohl(peer_init->init_hdr.a_rwnd); 2411 asoc->peer.i.num_outbound_streams = 2412 ntohs(peer_init->init_hdr.num_outbound_streams); 2413 asoc->peer.i.num_inbound_streams = 2414 ntohs(peer_init->init_hdr.num_inbound_streams); 2415 asoc->peer.i.initial_tsn = 2416 ntohl(peer_init->init_hdr.initial_tsn); 2417 2418 asoc->strreset_inseq = asoc->peer.i.initial_tsn; 2419 2420 /* Apply the upper bounds for output streams based on peer's 2421 * number of inbound streams. 2422 */ 2423 if (asoc->c.sinit_num_ostreams > 2424 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2425 asoc->c.sinit_num_ostreams = 2426 ntohs(peer_init->init_hdr.num_inbound_streams); 2427 } 2428 2429 if (asoc->c.sinit_max_instreams > 2430 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2431 asoc->c.sinit_max_instreams = 2432 ntohs(peer_init->init_hdr.num_outbound_streams); 2433 } 2434 2435 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2436 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2437 2438 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2439 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2440 2441 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2442 * high (for example, implementations MAY use the size of the receiver 2443 * advertised window). 2444 */ 2445 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2446 transports) { 2447 transport->ssthresh = asoc->peer.i.a_rwnd; 2448 } 2449 2450 /* Set up the TSN tracking pieces. */ 2451 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2452 asoc->peer.i.initial_tsn, gfp)) 2453 goto clean_up; 2454 2455 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2456 * 2457 * The stream sequence number in all the streams shall start 2458 * from 0 when the association is established. Also, when the 2459 * stream sequence number reaches the value 65535 the next 2460 * stream sequence number shall be set to 0. 2461 */ 2462 2463 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams, 2464 asoc->c.sinit_max_instreams, gfp)) 2465 goto clean_up; 2466 2467 /* Update frag_point when stream_interleave may get changed. */ 2468 sctp_assoc_update_frag_point(asoc); 2469 2470 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp)) 2471 goto clean_up; 2472 2473 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2474 * 2475 * When an endpoint has an ASCONF signaled change to be sent to the 2476 * remote endpoint it should do the following: 2477 * ... 2478 * A2) A serial number should be assigned to the Chunk. The serial 2479 * number should be a monotonically increasing number. All serial 2480 * numbers are defined to be initialized at the start of the 2481 * association to the same value as the Initial TSN. 2482 */ 2483 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2484 return 1; 2485 2486clean_up: 2487 /* Release the transport structures. */ 2488 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2489 transport = list_entry(pos, struct sctp_transport, transports); 2490 if (transport->state != SCTP_ACTIVE) 2491 sctp_assoc_rm_peer(asoc, transport); 2492 } 2493 2494nomem: 2495 return 0; 2496} 2497 2498 2499/* Update asoc with the option described in param. 2500 * 2501 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2502 * 2503 * asoc is the association to update. 2504 * param is the variable length parameter to use for update. 2505 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2506 * If the current packet is an INIT we want to minimize the amount of 2507 * work we do. In particular, we should not build transport 2508 * structures for the addresses. 2509 */ 2510static int sctp_process_param(struct sctp_association *asoc, 2511 union sctp_params param, 2512 const union sctp_addr *peer_addr, 2513 gfp_t gfp) 2514{ 2515 struct sctp_endpoint *ep = asoc->ep; 2516 union sctp_addr_param *addr_param; 2517 struct net *net = asoc->base.net; 2518 struct sctp_transport *t; 2519 enum sctp_scope scope; 2520 union sctp_addr addr; 2521 struct sctp_af *af; 2522 int retval = 1, i; 2523 u32 stale; 2524 __u16 sat; 2525 2526 /* We maintain all INIT parameters in network byte order all the 2527 * time. This allows us to not worry about whether the parameters 2528 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2529 */ 2530 switch (param.p->type) { 2531 case SCTP_PARAM_IPV6_ADDRESS: 2532 if (PF_INET6 != asoc->base.sk->sk_family) 2533 break; 2534 goto do_addr_param; 2535 2536 case SCTP_PARAM_IPV4_ADDRESS: 2537 /* v4 addresses are not allowed on v6-only socket */ 2538 if (ipv6_only_sock(asoc->base.sk)) 2539 break; 2540do_addr_param: 2541 af = sctp_get_af_specific(param_type2af(param.p->type)); 2542 if (!af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0)) 2543 break; 2544 scope = sctp_scope(peer_addr); 2545 if (sctp_in_scope(net, &addr, scope)) 2546 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2547 return 0; 2548 break; 2549 2550 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2551 if (!net->sctp.cookie_preserve_enable) 2552 break; 2553 2554 stale = ntohl(param.life->lifespan_increment); 2555 2556 /* Suggested Cookie Life span increment's unit is msec, 2557 * (1/1000sec). 2558 */ 2559 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale); 2560 break; 2561 2562 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2563 /* Turn off the default values first so we'll know which 2564 * ones are really set by the peer. 2565 */ 2566 asoc->peer.ipv4_address = 0; 2567 asoc->peer.ipv6_address = 0; 2568 2569 /* Assume that peer supports the address family 2570 * by which it sends a packet. 2571 */ 2572 if (peer_addr->sa.sa_family == AF_INET6) 2573 asoc->peer.ipv6_address = 1; 2574 else if (peer_addr->sa.sa_family == AF_INET) 2575 asoc->peer.ipv4_address = 1; 2576 2577 /* Cycle through address types; avoid divide by 0. */ 2578 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2579 if (sat) 2580 sat /= sizeof(__u16); 2581 2582 for (i = 0; i < sat; ++i) { 2583 switch (param.sat->types[i]) { 2584 case SCTP_PARAM_IPV4_ADDRESS: 2585 asoc->peer.ipv4_address = 1; 2586 break; 2587 2588 case SCTP_PARAM_IPV6_ADDRESS: 2589 if (PF_INET6 == asoc->base.sk->sk_family) 2590 asoc->peer.ipv6_address = 1; 2591 break; 2592 2593 default: /* Just ignore anything else. */ 2594 break; 2595 } 2596 } 2597 break; 2598 2599 case SCTP_PARAM_STATE_COOKIE: 2600 asoc->peer.cookie_len = 2601 ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2602 kfree(asoc->peer.cookie); 2603 asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp); 2604 if (!asoc->peer.cookie) 2605 retval = 0; 2606 break; 2607 2608 case SCTP_PARAM_HEARTBEAT_INFO: 2609 /* Would be odd to receive, but it causes no problems. */ 2610 break; 2611 2612 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2613 /* Rejected during verify stage. */ 2614 break; 2615 2616 case SCTP_PARAM_ECN_CAPABLE: 2617 if (asoc->ep->ecn_enable) { 2618 asoc->peer.ecn_capable = 1; 2619 break; 2620 } 2621 /* Fall Through */ 2622 goto fall_through; 2623 2624 2625 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2626 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2627 break; 2628 2629 case SCTP_PARAM_SET_PRIMARY: 2630 if (!ep->asconf_enable) 2631 goto fall_through; 2632 2633 addr_param = param.v + sizeof(struct sctp_addip_param); 2634 2635 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 2636 if (!af) 2637 break; 2638 2639 if (!af->from_addr_param(&addr, addr_param, 2640 htons(asoc->peer.port), 0)) 2641 break; 2642 2643 if (!af->addr_valid(&addr, NULL, NULL)) 2644 break; 2645 2646 t = sctp_assoc_lookup_paddr(asoc, &addr); 2647 if (!t) 2648 break; 2649 2650 sctp_assoc_set_primary(asoc, t); 2651 break; 2652 2653 case SCTP_PARAM_SUPPORTED_EXT: 2654 sctp_process_ext_param(asoc, param); 2655 break; 2656 2657 case SCTP_PARAM_FWD_TSN_SUPPORT: 2658 if (asoc->ep->prsctp_enable) { 2659 asoc->peer.prsctp_capable = 1; 2660 break; 2661 } 2662 /* Fall Through */ 2663 goto fall_through; 2664 2665 case SCTP_PARAM_RANDOM: 2666 if (!ep->auth_enable) 2667 goto fall_through; 2668 2669 /* Save peer's random parameter */ 2670 kfree(asoc->peer.peer_random); 2671 asoc->peer.peer_random = kmemdup(param.p, 2672 ntohs(param.p->length), gfp); 2673 if (!asoc->peer.peer_random) { 2674 retval = 0; 2675 break; 2676 } 2677 break; 2678 2679 case SCTP_PARAM_HMAC_ALGO: 2680 if (!ep->auth_enable) 2681 goto fall_through; 2682 2683 /* Save peer's HMAC list */ 2684 kfree(asoc->peer.peer_hmacs); 2685 asoc->peer.peer_hmacs = kmemdup(param.p, 2686 ntohs(param.p->length), gfp); 2687 if (!asoc->peer.peer_hmacs) { 2688 retval = 0; 2689 break; 2690 } 2691 2692 /* Set the default HMAC the peer requested*/ 2693 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2694 break; 2695 2696 case SCTP_PARAM_CHUNKS: 2697 if (!ep->auth_enable) 2698 goto fall_through; 2699 2700 kfree(asoc->peer.peer_chunks); 2701 asoc->peer.peer_chunks = kmemdup(param.p, 2702 ntohs(param.p->length), gfp); 2703 if (!asoc->peer.peer_chunks) 2704 retval = 0; 2705 break; 2706fall_through: 2707 default: 2708 /* Any unrecognized parameters should have been caught 2709 * and handled by sctp_verify_param() which should be 2710 * called prior to this routine. Simply log the error 2711 * here. 2712 */ 2713 pr_debug("%s: ignoring param:%d for association:%p.\n", 2714 __func__, ntohs(param.p->type), asoc); 2715 break; 2716 } 2717 2718 return retval; 2719} 2720 2721/* Select a new verification tag. */ 2722__u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2723{ 2724 /* I believe that this random number generator complies with RFC1750. 2725 * A tag of 0 is reserved for special cases (e.g. INIT). 2726 */ 2727 __u32 x; 2728 2729 do { 2730 get_random_bytes(&x, sizeof(__u32)); 2731 } while (x == 0); 2732 2733 return x; 2734} 2735 2736/* Select an initial TSN to send during startup. */ 2737__u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2738{ 2739 __u32 retval; 2740 2741 get_random_bytes(&retval, sizeof(__u32)); 2742 return retval; 2743} 2744 2745/* 2746 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2747 * 0 1 2 3 2748 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2749 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2750 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2751 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2752 * | Serial Number | 2753 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2754 * | Address Parameter | 2755 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2756 * | ASCONF Parameter #1 | 2757 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2758 * \ \ 2759 * / .... / 2760 * \ \ 2761 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2762 * | ASCONF Parameter #N | 2763 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2764 * 2765 * Address Parameter and other parameter will not be wrapped in this function 2766 */ 2767static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2768 union sctp_addr *addr, 2769 int vparam_len) 2770{ 2771 struct sctp_addiphdr asconf; 2772 struct sctp_chunk *retval; 2773 int length = sizeof(asconf) + vparam_len; 2774 union sctp_addr_param addrparam; 2775 int addrlen; 2776 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2777 2778 addrlen = af->to_addr_param(addr, &addrparam); 2779 if (!addrlen) 2780 return NULL; 2781 length += addrlen; 2782 2783 /* Create the chunk. */ 2784 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length, 2785 GFP_ATOMIC); 2786 if (!retval) 2787 return NULL; 2788 2789 asconf.serial = htonl(asoc->addip_serial++); 2790 2791 retval->subh.addip_hdr = 2792 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2793 retval->param_hdr.v = 2794 sctp_addto_chunk(retval, addrlen, &addrparam); 2795 2796 return retval; 2797} 2798 2799/* ADDIP 2800 * 3.2.1 Add IP Address 2801 * 0 1 2 3 2802 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2803 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2804 * | Type = 0xC001 | Length = Variable | 2805 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2806 * | ASCONF-Request Correlation ID | 2807 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2808 * | Address Parameter | 2809 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2810 * 2811 * 3.2.2 Delete IP Address 2812 * 0 1 2 3 2813 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2814 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2815 * | Type = 0xC002 | Length = Variable | 2816 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2817 * | ASCONF-Request Correlation ID | 2818 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2819 * | Address Parameter | 2820 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2821 * 2822 */ 2823struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2824 union sctp_addr *laddr, 2825 struct sockaddr *addrs, 2826 int addrcnt, __be16 flags) 2827{ 2828 union sctp_addr_param addr_param; 2829 struct sctp_addip_param param; 2830 int paramlen = sizeof(param); 2831 struct sctp_chunk *retval; 2832 int addr_param_len = 0; 2833 union sctp_addr *addr; 2834 int totallen = 0, i; 2835 int del_pickup = 0; 2836 struct sctp_af *af; 2837 void *addr_buf; 2838 2839 /* Get total length of all the address parameters. */ 2840 addr_buf = addrs; 2841 for (i = 0; i < addrcnt; i++) { 2842 addr = addr_buf; 2843 af = sctp_get_af_specific(addr->v4.sin_family); 2844 addr_param_len = af->to_addr_param(addr, &addr_param); 2845 2846 totallen += paramlen; 2847 totallen += addr_param_len; 2848 2849 addr_buf += af->sockaddr_len; 2850 if (asoc->asconf_addr_del_pending && !del_pickup) { 2851 /* reuse the parameter length from the same scope one */ 2852 totallen += paramlen; 2853 totallen += addr_param_len; 2854 del_pickup = 1; 2855 2856 pr_debug("%s: picked same-scope del_pending addr, " 2857 "totallen for all addresses is %d\n", 2858 __func__, totallen); 2859 } 2860 } 2861 2862 /* Create an asconf chunk with the required length. */ 2863 retval = sctp_make_asconf(asoc, laddr, totallen); 2864 if (!retval) 2865 return NULL; 2866 2867 /* Add the address parameters to the asconf chunk. */ 2868 addr_buf = addrs; 2869 for (i = 0; i < addrcnt; i++) { 2870 addr = addr_buf; 2871 af = sctp_get_af_specific(addr->v4.sin_family); 2872 addr_param_len = af->to_addr_param(addr, &addr_param); 2873 param.param_hdr.type = flags; 2874 param.param_hdr.length = htons(paramlen + addr_param_len); 2875 param.crr_id = htonl(i); 2876 2877 sctp_addto_chunk(retval, paramlen, ¶m); 2878 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2879 2880 addr_buf += af->sockaddr_len; 2881 } 2882 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2883 addr = asoc->asconf_addr_del_pending; 2884 af = sctp_get_af_specific(addr->v4.sin_family); 2885 addr_param_len = af->to_addr_param(addr, &addr_param); 2886 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2887 param.param_hdr.length = htons(paramlen + addr_param_len); 2888 param.crr_id = htonl(i); 2889 2890 sctp_addto_chunk(retval, paramlen, ¶m); 2891 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2892 } 2893 return retval; 2894} 2895 2896/* ADDIP 2897 * 3.2.4 Set Primary IP Address 2898 * 0 1 2 3 2899 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2900 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2901 * | Type =0xC004 | Length = Variable | 2902 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2903 * | ASCONF-Request Correlation ID | 2904 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2905 * | Address Parameter | 2906 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2907 * 2908 * Create an ASCONF chunk with Set Primary IP address parameter. 2909 */ 2910struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2911 union sctp_addr *addr) 2912{ 2913 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2914 union sctp_addr_param addrparam; 2915 struct sctp_addip_param param; 2916 struct sctp_chunk *retval; 2917 int len = sizeof(param); 2918 int addrlen; 2919 2920 addrlen = af->to_addr_param(addr, &addrparam); 2921 if (!addrlen) 2922 return NULL; 2923 len += addrlen; 2924 2925 /* Create the chunk and make asconf header. */ 2926 retval = sctp_make_asconf(asoc, addr, len); 2927 if (!retval) 2928 return NULL; 2929 2930 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2931 param.param_hdr.length = htons(len); 2932 param.crr_id = 0; 2933 2934 sctp_addto_chunk(retval, sizeof(param), ¶m); 2935 sctp_addto_chunk(retval, addrlen, &addrparam); 2936 2937 return retval; 2938} 2939 2940/* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2941 * 0 1 2 3 2942 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2943 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2944 * | Type = 0x80 | Chunk Flags | Chunk Length | 2945 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2946 * | Serial Number | 2947 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2948 * | ASCONF Parameter Response#1 | 2949 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2950 * \ \ 2951 * / .... / 2952 * \ \ 2953 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2954 * | ASCONF Parameter Response#N | 2955 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2956 * 2957 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2958 */ 2959static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2960 __u32 serial, int vparam_len) 2961{ 2962 struct sctp_addiphdr asconf; 2963 struct sctp_chunk *retval; 2964 int length = sizeof(asconf) + vparam_len; 2965 2966 /* Create the chunk. */ 2967 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length, 2968 GFP_ATOMIC); 2969 if (!retval) 2970 return NULL; 2971 2972 asconf.serial = htonl(serial); 2973 2974 retval->subh.addip_hdr = 2975 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2976 2977 return retval; 2978} 2979 2980/* Add response parameters to an ASCONF_ACK chunk. */ 2981static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2982 __be16 err_code, 2983 struct sctp_addip_param *asconf_param) 2984{ 2985 struct sctp_addip_param ack_param; 2986 struct sctp_errhdr err_param; 2987 int asconf_param_len = 0; 2988 int err_param_len = 0; 2989 __be16 response_type; 2990 2991 if (SCTP_ERROR_NO_ERROR == err_code) { 2992 response_type = SCTP_PARAM_SUCCESS_REPORT; 2993 } else { 2994 response_type = SCTP_PARAM_ERR_CAUSE; 2995 err_param_len = sizeof(err_param); 2996 if (asconf_param) 2997 asconf_param_len = 2998 ntohs(asconf_param->param_hdr.length); 2999 } 3000 3001 /* Add Success Indication or Error Cause Indication parameter. */ 3002 ack_param.param_hdr.type = response_type; 3003 ack_param.param_hdr.length = htons(sizeof(ack_param) + 3004 err_param_len + 3005 asconf_param_len); 3006 ack_param.crr_id = crr_id; 3007 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 3008 3009 if (SCTP_ERROR_NO_ERROR == err_code) 3010 return; 3011 3012 /* Add Error Cause parameter. */ 3013 err_param.cause = err_code; 3014 err_param.length = htons(err_param_len + asconf_param_len); 3015 sctp_addto_chunk(chunk, err_param_len, &err_param); 3016 3017 /* Add the failed TLV copied from ASCONF chunk. */ 3018 if (asconf_param) 3019 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 3020} 3021 3022/* Process a asconf parameter. */ 3023static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 3024 struct sctp_chunk *asconf, 3025 struct sctp_addip_param *asconf_param) 3026{ 3027 union sctp_addr_param *addr_param; 3028 struct sctp_transport *peer; 3029 union sctp_addr addr; 3030 struct sctp_af *af; 3031 3032 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3033 3034 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 3035 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 3036 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 3037 return SCTP_ERROR_UNKNOWN_PARAM; 3038 3039 switch (addr_param->p.type) { 3040 case SCTP_PARAM_IPV6_ADDRESS: 3041 if (!asoc->peer.ipv6_address) 3042 return SCTP_ERROR_DNS_FAILED; 3043 break; 3044 case SCTP_PARAM_IPV4_ADDRESS: 3045 if (!asoc->peer.ipv4_address) 3046 return SCTP_ERROR_DNS_FAILED; 3047 break; 3048 default: 3049 return SCTP_ERROR_DNS_FAILED; 3050 } 3051 3052 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3053 if (unlikely(!af)) 3054 return SCTP_ERROR_DNS_FAILED; 3055 3056 if (!af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0)) 3057 return SCTP_ERROR_DNS_FAILED; 3058 3059 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3060 * or multicast address. 3061 * (note: wildcard is permitted and requires special handling so 3062 * make sure we check for that) 3063 */ 3064 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3065 return SCTP_ERROR_DNS_FAILED; 3066 3067 switch (asconf_param->param_hdr.type) { 3068 case SCTP_PARAM_ADD_IP: 3069 /* Section 4.2.1: 3070 * If the address 0.0.0.0 or ::0 is provided, the source 3071 * address of the packet MUST be added. 3072 */ 3073 if (af->is_any(&addr)) 3074 memcpy(&addr, &asconf->source, sizeof(addr)); 3075 3076 if (security_sctp_bind_connect(asoc->ep->base.sk, 3077 SCTP_PARAM_ADD_IP, 3078 (struct sockaddr *)&addr, 3079 af->sockaddr_len)) 3080 return SCTP_ERROR_REQ_REFUSED; 3081 3082 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3083 * request and does not have the local resources to add this 3084 * new address to the association, it MUST return an Error 3085 * Cause TLV set to the new error code 'Operation Refused 3086 * Due to Resource Shortage'. 3087 */ 3088 3089 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3090 if (!peer) 3091 return SCTP_ERROR_RSRC_LOW; 3092 3093 /* Start the heartbeat timer. */ 3094 sctp_transport_reset_hb_timer(peer); 3095 asoc->new_transport = peer; 3096 break; 3097 case SCTP_PARAM_DEL_IP: 3098 /* ADDIP 4.3 D7) If a request is received to delete the 3099 * last remaining IP address of a peer endpoint, the receiver 3100 * MUST send an Error Cause TLV with the error cause set to the 3101 * new error code 'Request to Delete Last Remaining IP Address'. 3102 */ 3103 if (asoc->peer.transport_count == 1) 3104 return SCTP_ERROR_DEL_LAST_IP; 3105 3106 /* ADDIP 4.3 D8) If a request is received to delete an IP 3107 * address which is also the source address of the IP packet 3108 * which contained the ASCONF chunk, the receiver MUST reject 3109 * this request. To reject the request the receiver MUST send 3110 * an Error Cause TLV set to the new error code 'Request to 3111 * Delete Source IP Address' 3112 */ 3113 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3114 return SCTP_ERROR_DEL_SRC_IP; 3115 3116 /* Section 4.2.2 3117 * If the address 0.0.0.0 or ::0 is provided, all 3118 * addresses of the peer except the source address of the 3119 * packet MUST be deleted. 3120 */ 3121 if (af->is_any(&addr)) { 3122 sctp_assoc_set_primary(asoc, asconf->transport); 3123 sctp_assoc_del_nonprimary_peers(asoc, 3124 asconf->transport); 3125 return SCTP_ERROR_NO_ERROR; 3126 } 3127 3128 /* If the address is not part of the association, the 3129 * ASCONF-ACK with Error Cause Indication Parameter 3130 * which including cause of Unresolvable Address should 3131 * be sent. 3132 */ 3133 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3134 if (!peer) 3135 return SCTP_ERROR_DNS_FAILED; 3136 3137 sctp_assoc_rm_peer(asoc, peer); 3138 break; 3139 case SCTP_PARAM_SET_PRIMARY: 3140 /* ADDIP Section 4.2.4 3141 * If the address 0.0.0.0 or ::0 is provided, the receiver 3142 * MAY mark the source address of the packet as its 3143 * primary. 3144 */ 3145 if (af->is_any(&addr)) 3146 memcpy(&addr, sctp_source(asconf), sizeof(addr)); 3147 3148 if (security_sctp_bind_connect(asoc->ep->base.sk, 3149 SCTP_PARAM_SET_PRIMARY, 3150 (struct sockaddr *)&addr, 3151 af->sockaddr_len)) 3152 return SCTP_ERROR_REQ_REFUSED; 3153 3154 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3155 if (!peer) 3156 return SCTP_ERROR_DNS_FAILED; 3157 3158 sctp_assoc_set_primary(asoc, peer); 3159 break; 3160 } 3161 3162 return SCTP_ERROR_NO_ERROR; 3163} 3164 3165/* Verify the ASCONF packet before we process it. */ 3166bool sctp_verify_asconf(const struct sctp_association *asoc, 3167 struct sctp_chunk *chunk, bool addr_param_needed, 3168 struct sctp_paramhdr **errp) 3169{ 3170 struct sctp_addip_chunk *addip; 3171 bool addr_param_seen = false; 3172 union sctp_params param; 3173 3174 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr; 3175 sctp_walk_params(param, addip) { 3176 size_t length = ntohs(param.p->length); 3177 3178 *errp = param.p; 3179 switch (param.p->type) { 3180 case SCTP_PARAM_ERR_CAUSE: 3181 break; 3182 case SCTP_PARAM_IPV4_ADDRESS: 3183 if (length != sizeof(struct sctp_ipv4addr_param)) 3184 return false; 3185 /* ensure there is only one addr param and it's in the 3186 * beginning of addip_hdr params, or we reject it. 3187 */ 3188 if (param.v != (addip + 1)) 3189 return false; 3190 addr_param_seen = true; 3191 break; 3192 case SCTP_PARAM_IPV6_ADDRESS: 3193 if (length != sizeof(struct sctp_ipv6addr_param)) 3194 return false; 3195 if (param.v != (addip + 1)) 3196 return false; 3197 addr_param_seen = true; 3198 break; 3199 case SCTP_PARAM_ADD_IP: 3200 case SCTP_PARAM_DEL_IP: 3201 case SCTP_PARAM_SET_PRIMARY: 3202 /* In ASCONF chunks, these need to be first. */ 3203 if (addr_param_needed && !addr_param_seen) 3204 return false; 3205 length = ntohs(param.addip->param_hdr.length); 3206 if (length < sizeof(struct sctp_addip_param) + 3207 sizeof(**errp)) 3208 return false; 3209 break; 3210 case SCTP_PARAM_SUCCESS_REPORT: 3211 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3212 if (length != sizeof(struct sctp_addip_param)) 3213 return false; 3214 break; 3215 default: 3216 /* This is unknown to us, reject! */ 3217 return false; 3218 } 3219 } 3220 3221 /* Remaining sanity checks. */ 3222 if (addr_param_needed && !addr_param_seen) 3223 return false; 3224 if (!addr_param_needed && addr_param_seen) 3225 return false; 3226 if (param.v != chunk->chunk_end) 3227 return false; 3228 3229 return true; 3230} 3231 3232/* Process an incoming ASCONF chunk with the next expected serial no. and 3233 * return an ASCONF_ACK chunk to be sent in response. 3234 */ 3235struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3236 struct sctp_chunk *asconf) 3237{ 3238 union sctp_addr_param *addr_param; 3239 struct sctp_addip_chunk *addip; 3240 struct sctp_chunk *asconf_ack; 3241 bool all_param_pass = true; 3242 struct sctp_addiphdr *hdr; 3243 int length = 0, chunk_len; 3244 union sctp_params param; 3245 __be16 err_code; 3246 __u32 serial; 3247 3248 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr; 3249 chunk_len = ntohs(asconf->chunk_hdr->length) - 3250 sizeof(struct sctp_chunkhdr); 3251 hdr = (struct sctp_addiphdr *)asconf->skb->data; 3252 serial = ntohl(hdr->serial); 3253 3254 /* Skip the addiphdr and store a pointer to address parameter. */ 3255 length = sizeof(*hdr); 3256 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3257 chunk_len -= length; 3258 3259 /* Skip the address parameter and store a pointer to the first 3260 * asconf parameter. 3261 */ 3262 length = ntohs(addr_param->p.length); 3263 chunk_len -= length; 3264 3265 /* create an ASCONF_ACK chunk. 3266 * Based on the definitions of parameters, we know that the size of 3267 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3268 * parameters. 3269 */ 3270 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3271 if (!asconf_ack) 3272 goto done; 3273 3274 /* Process the TLVs contained within the ASCONF chunk. */ 3275 sctp_walk_params(param, addip) { 3276 /* Skip preceding address parameters. */ 3277 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 3278 param.p->type == SCTP_PARAM_IPV6_ADDRESS) 3279 continue; 3280 3281 err_code = sctp_process_asconf_param(asoc, asconf, 3282 param.addip); 3283 /* ADDIP 4.1 A7) 3284 * If an error response is received for a TLV parameter, 3285 * all TLVs with no response before the failed TLV are 3286 * considered successful if not reported. All TLVs after 3287 * the failed response are considered unsuccessful unless 3288 * a specific success indication is present for the parameter. 3289 */ 3290 if (err_code != SCTP_ERROR_NO_ERROR) 3291 all_param_pass = false; 3292 if (!all_param_pass) 3293 sctp_add_asconf_response(asconf_ack, param.addip->crr_id, 3294 err_code, param.addip); 3295 3296 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3297 * an IP address sends an 'Out of Resource' in its response, it 3298 * MUST also fail any subsequent add or delete requests bundled 3299 * in the ASCONF. 3300 */ 3301 if (err_code == SCTP_ERROR_RSRC_LOW) 3302 goto done; 3303 } 3304done: 3305 asoc->peer.addip_serial++; 3306 3307 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3308 * after freeing the reference to old asconf ack if any. 3309 */ 3310 if (asconf_ack) { 3311 sctp_chunk_hold(asconf_ack); 3312 list_add_tail(&asconf_ack->transmitted_list, 3313 &asoc->asconf_ack_list); 3314 } 3315 3316 return asconf_ack; 3317} 3318 3319/* Process a asconf parameter that is successfully acked. */ 3320static void sctp_asconf_param_success(struct sctp_association *asoc, 3321 struct sctp_addip_param *asconf_param) 3322{ 3323 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3324 union sctp_addr_param *addr_param; 3325 struct sctp_sockaddr_entry *saddr; 3326 struct sctp_transport *transport; 3327 union sctp_addr addr; 3328 struct sctp_af *af; 3329 3330 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3331 3332 /* We have checked the packet before, so we do not check again. */ 3333 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3334 if (!af->from_addr_param(&addr, addr_param, htons(bp->port), 0)) 3335 return; 3336 3337 switch (asconf_param->param_hdr.type) { 3338 case SCTP_PARAM_ADD_IP: 3339 /* This is always done in BH context with a socket lock 3340 * held, so the list can not change. 3341 */ 3342 local_bh_disable(); 3343 list_for_each_entry(saddr, &bp->address_list, list) { 3344 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3345 saddr->state = SCTP_ADDR_SRC; 3346 } 3347 local_bh_enable(); 3348 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3349 transports) { 3350 sctp_transport_dst_release(transport); 3351 } 3352 break; 3353 case SCTP_PARAM_DEL_IP: 3354 local_bh_disable(); 3355 sctp_del_bind_addr(bp, &addr); 3356 if (asoc->asconf_addr_del_pending != NULL && 3357 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3358 kfree(asoc->asconf_addr_del_pending); 3359 asoc->asconf_addr_del_pending = NULL; 3360 } 3361 local_bh_enable(); 3362 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3363 transports) { 3364 sctp_transport_dst_release(transport); 3365 } 3366 break; 3367 default: 3368 break; 3369 } 3370} 3371 3372/* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3373 * for the given asconf parameter. If there is no response for this parameter, 3374 * return the error code based on the third argument 'no_err'. 3375 * ADDIP 4.1 3376 * A7) If an error response is received for a TLV parameter, all TLVs with no 3377 * response before the failed TLV are considered successful if not reported. 3378 * All TLVs after the failed response are considered unsuccessful unless a 3379 * specific success indication is present for the parameter. 3380 */ 3381static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3382 struct sctp_addip_param *asconf_param, 3383 int no_err) 3384{ 3385 struct sctp_addip_param *asconf_ack_param; 3386 struct sctp_errhdr *err_param; 3387 int asconf_ack_len; 3388 __be16 err_code; 3389 int length; 3390 3391 if (no_err) 3392 err_code = SCTP_ERROR_NO_ERROR; 3393 else 3394 err_code = SCTP_ERROR_REQ_REFUSED; 3395 3396 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3397 sizeof(struct sctp_chunkhdr); 3398 3399 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3400 * the first asconf_ack parameter. 3401 */ 3402 length = sizeof(struct sctp_addiphdr); 3403 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data + 3404 length); 3405 asconf_ack_len -= length; 3406 3407 while (asconf_ack_len > 0) { 3408 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3409 switch (asconf_ack_param->param_hdr.type) { 3410 case SCTP_PARAM_SUCCESS_REPORT: 3411 return SCTP_ERROR_NO_ERROR; 3412 case SCTP_PARAM_ERR_CAUSE: 3413 length = sizeof(*asconf_ack_param); 3414 err_param = (void *)asconf_ack_param + length; 3415 asconf_ack_len -= length; 3416 if (asconf_ack_len > 0) 3417 return err_param->cause; 3418 else 3419 return SCTP_ERROR_INV_PARAM; 3420 break; 3421 default: 3422 return SCTP_ERROR_INV_PARAM; 3423 } 3424 } 3425 3426 length = ntohs(asconf_ack_param->param_hdr.length); 3427 asconf_ack_param = (void *)asconf_ack_param + length; 3428 asconf_ack_len -= length; 3429 } 3430 3431 return err_code; 3432} 3433 3434/* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3435int sctp_process_asconf_ack(struct sctp_association *asoc, 3436 struct sctp_chunk *asconf_ack) 3437{ 3438 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3439 struct sctp_addip_param *asconf_param; 3440 __be16 err_code = SCTP_ERROR_NO_ERROR; 3441 union sctp_addr_param *addr_param; 3442 int asconf_len = asconf->skb->len; 3443 int all_param_pass = 0; 3444 int length = 0; 3445 int no_err = 1; 3446 int retval = 0; 3447 3448 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3449 * a pointer to address parameter. 3450 */ 3451 length = sizeof(struct sctp_addip_chunk); 3452 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3453 asconf_len -= length; 3454 3455 /* Skip the address parameter in the last asconf sent and store a 3456 * pointer to the first asconf parameter. 3457 */ 3458 length = ntohs(addr_param->p.length); 3459 asconf_param = (void *)addr_param + length; 3460 asconf_len -= length; 3461 3462 /* ADDIP 4.1 3463 * A8) If there is no response(s) to specific TLV parameter(s), and no 3464 * failures are indicated, then all request(s) are considered 3465 * successful. 3466 */ 3467 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr)) 3468 all_param_pass = 1; 3469 3470 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3471 while (asconf_len > 0) { 3472 if (all_param_pass) 3473 err_code = SCTP_ERROR_NO_ERROR; 3474 else { 3475 err_code = sctp_get_asconf_response(asconf_ack, 3476 asconf_param, 3477 no_err); 3478 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3479 no_err = 0; 3480 } 3481 3482 switch (err_code) { 3483 case SCTP_ERROR_NO_ERROR: 3484 sctp_asconf_param_success(asoc, asconf_param); 3485 break; 3486 3487 case SCTP_ERROR_RSRC_LOW: 3488 retval = 1; 3489 break; 3490 3491 case SCTP_ERROR_UNKNOWN_PARAM: 3492 /* Disable sending this type of asconf parameter in 3493 * future. 3494 */ 3495 asoc->peer.addip_disabled_mask |= 3496 asconf_param->param_hdr.type; 3497 break; 3498 3499 case SCTP_ERROR_REQ_REFUSED: 3500 case SCTP_ERROR_DEL_LAST_IP: 3501 case SCTP_ERROR_DEL_SRC_IP: 3502 default: 3503 break; 3504 } 3505 3506 /* Skip the processed asconf parameter and move to the next 3507 * one. 3508 */ 3509 length = ntohs(asconf_param->param_hdr.length); 3510 asconf_param = (void *)asconf_param + length; 3511 asconf_len -= length; 3512 } 3513 3514 if (no_err && asoc->src_out_of_asoc_ok) { 3515 asoc->src_out_of_asoc_ok = 0; 3516 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3517 } 3518 3519 /* Free the cached last sent asconf chunk. */ 3520 list_del_init(&asconf->transmitted_list); 3521 sctp_chunk_free(asconf); 3522 asoc->addip_last_asconf = NULL; 3523 3524 return retval; 3525} 3526 3527/* Make a FWD TSN chunk. */ 3528struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3529 __u32 new_cum_tsn, size_t nstreams, 3530 struct sctp_fwdtsn_skip *skiplist) 3531{ 3532 struct sctp_chunk *retval = NULL; 3533 struct sctp_fwdtsn_hdr ftsn_hdr; 3534 struct sctp_fwdtsn_skip skip; 3535 size_t hint; 3536 int i; 3537 3538 hint = (nstreams + 1) * sizeof(__u32); 3539 3540 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC); 3541 3542 if (!retval) 3543 return NULL; 3544 3545 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3546 retval->subh.fwdtsn_hdr = 3547 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3548 3549 for (i = 0; i < nstreams; i++) { 3550 skip.stream = skiplist[i].stream; 3551 skip.ssn = skiplist[i].ssn; 3552 sctp_addto_chunk(retval, sizeof(skip), &skip); 3553 } 3554 3555 return retval; 3556} 3557 3558struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc, 3559 __u32 new_cum_tsn, size_t nstreams, 3560 struct sctp_ifwdtsn_skip *skiplist) 3561{ 3562 struct sctp_chunk *retval = NULL; 3563 struct sctp_ifwdtsn_hdr ftsn_hdr; 3564 size_t hint; 3565 3566 hint = (nstreams + 1) * sizeof(__u32); 3567 3568 retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint, 3569 GFP_ATOMIC); 3570 if (!retval) 3571 return NULL; 3572 3573 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3574 retval->subh.ifwdtsn_hdr = 3575 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3576 3577 sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist); 3578 3579 return retval; 3580} 3581 3582/* RE-CONFIG 3.1 (RE-CONFIG chunk) 3583 * 0 1 2 3 3584 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 3585 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3586 * | Type = 130 | Chunk Flags | Chunk Length | 3587 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3588 * \ \ 3589 * / Re-configuration Parameter / 3590 * \ \ 3591 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3592 * \ \ 3593 * / Re-configuration Parameter (optional) / 3594 * \ \ 3595 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3596 */ 3597static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc, 3598 int length) 3599{ 3600 struct sctp_reconf_chunk *reconf; 3601 struct sctp_chunk *retval; 3602 3603 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length, 3604 GFP_ATOMIC); 3605 if (!retval) 3606 return NULL; 3607 3608 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr; 3609 retval->param_hdr.v = (u8 *)(reconf + 1); 3610 3611 return retval; 3612} 3613 3614/* RE-CONFIG 4.1 (STREAM OUT RESET) 3615 * 0 1 2 3 3616 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 3617 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3618 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N | 3619 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3620 * | Re-configuration Request Sequence Number | 3621 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3622 * | Re-configuration Response Sequence Number | 3623 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3624 * | Sender's Last Assigned TSN | 3625 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3626 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3627 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3628 * / ...... / 3629 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3630 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3631 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3632 * 3633 * RE-CONFIG 4.2 (STREAM IN RESET) 3634 * 0 1 2 3 3635 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 3636 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3637 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N | 3638 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3639 * | Re-configuration Request Sequence Number | 3640 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3641 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3642 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3643 * / ...... / 3644 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3645 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3646 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3647 */ 3648struct sctp_chunk *sctp_make_strreset_req( 3649 const struct sctp_association *asoc, 3650 __u16 stream_num, __be16 *stream_list, 3651 bool out, bool in) 3652{ 3653 __u16 stream_len = stream_num * sizeof(__u16); 3654 struct sctp_strreset_outreq outreq; 3655 struct sctp_strreset_inreq inreq; 3656 struct sctp_chunk *retval; 3657 __u16 outlen, inlen; 3658 3659 outlen = (sizeof(outreq) + stream_len) * out; 3660 inlen = (sizeof(inreq) + stream_len) * in; 3661 3662 retval = sctp_make_reconf(asoc, SCTP_PAD4(outlen) + SCTP_PAD4(inlen)); 3663 if (!retval) 3664 return NULL; 3665 3666 if (outlen) { 3667 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST; 3668 outreq.param_hdr.length = htons(outlen); 3669 outreq.request_seq = htonl(asoc->strreset_outseq); 3670 outreq.response_seq = htonl(asoc->strreset_inseq - 1); 3671 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1); 3672 3673 sctp_addto_chunk(retval, sizeof(outreq), &outreq); 3674 3675 if (stream_len) 3676 sctp_addto_chunk(retval, stream_len, stream_list); 3677 } 3678 3679 if (inlen) { 3680 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST; 3681 inreq.param_hdr.length = htons(inlen); 3682 inreq.request_seq = htonl(asoc->strreset_outseq + out); 3683 3684 sctp_addto_chunk(retval, sizeof(inreq), &inreq); 3685 3686 if (stream_len) 3687 sctp_addto_chunk(retval, stream_len, stream_list); 3688 } 3689 3690 return retval; 3691} 3692 3693/* RE-CONFIG 4.3 (SSN/TSN RESET ALL) 3694 * 0 1 2 3 3695 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 3696 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3697 * | Parameter Type = 15 | Parameter Length = 8 | 3698 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3699 * | Re-configuration Request Sequence Number | 3700 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3701 */ 3702struct sctp_chunk *sctp_make_strreset_tsnreq( 3703 const struct sctp_association *asoc) 3704{ 3705 struct sctp_strreset_tsnreq tsnreq; 3706 __u16 length = sizeof(tsnreq); 3707 struct sctp_chunk *retval; 3708 3709 retval = sctp_make_reconf(asoc, length); 3710 if (!retval) 3711 return NULL; 3712 3713 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST; 3714 tsnreq.param_hdr.length = htons(length); 3715 tsnreq.request_seq = htonl(asoc->strreset_outseq); 3716 3717 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq); 3718 3719 return retval; 3720} 3721 3722/* RE-CONFIG 4.5/4.6 (ADD STREAM) 3723 * 0 1 2 3 3724 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 3725 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3726 * | Parameter Type = 17 | Parameter Length = 12 | 3727 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3728 * | Re-configuration Request Sequence Number | 3729 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3730 * | Number of new streams | Reserved | 3731 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3732 */ 3733struct sctp_chunk *sctp_make_strreset_addstrm( 3734 const struct sctp_association *asoc, 3735 __u16 out, __u16 in) 3736{ 3737 struct sctp_strreset_addstrm addstrm; 3738 __u16 size = sizeof(addstrm); 3739 struct sctp_chunk *retval; 3740 3741 retval = sctp_make_reconf(asoc, (!!out + !!in) * size); 3742 if (!retval) 3743 return NULL; 3744 3745 if (out) { 3746 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS; 3747 addstrm.param_hdr.length = htons(size); 3748 addstrm.number_of_streams = htons(out); 3749 addstrm.request_seq = htonl(asoc->strreset_outseq); 3750 addstrm.reserved = 0; 3751 3752 sctp_addto_chunk(retval, size, &addstrm); 3753 } 3754 3755 if (in) { 3756 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS; 3757 addstrm.param_hdr.length = htons(size); 3758 addstrm.number_of_streams = htons(in); 3759 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out); 3760 addstrm.reserved = 0; 3761 3762 sctp_addto_chunk(retval, size, &addstrm); 3763 } 3764 3765 return retval; 3766} 3767 3768/* RE-CONFIG 4.4 (RESP) 3769 * 0 1 2 3 3770 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 3771 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3772 * | Parameter Type = 16 | Parameter Length | 3773 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3774 * | Re-configuration Response Sequence Number | 3775 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3776 * | Result | 3777 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3778 */ 3779struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc, 3780 __u32 result, __u32 sn) 3781{ 3782 struct sctp_strreset_resp resp; 3783 __u16 length = sizeof(resp); 3784 struct sctp_chunk *retval; 3785 3786 retval = sctp_make_reconf(asoc, length); 3787 if (!retval) 3788 return NULL; 3789 3790 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3791 resp.param_hdr.length = htons(length); 3792 resp.response_seq = htonl(sn); 3793 resp.result = htonl(result); 3794 3795 sctp_addto_chunk(retval, sizeof(resp), &resp); 3796 3797 return retval; 3798} 3799 3800/* RE-CONFIG 4.4 OPTIONAL (TSNRESP) 3801 * 0 1 2 3 3802 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 3803 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3804 * | Parameter Type = 16 | Parameter Length | 3805 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3806 * | Re-configuration Response Sequence Number | 3807 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3808 * | Result | 3809 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3810 * | Sender's Next TSN (optional) | 3811 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3812 * | Receiver's Next TSN (optional) | 3813 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3814 */ 3815struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc, 3816 __u32 result, __u32 sn, 3817 __u32 sender_tsn, 3818 __u32 receiver_tsn) 3819{ 3820 struct sctp_strreset_resptsn tsnresp; 3821 __u16 length = sizeof(tsnresp); 3822 struct sctp_chunk *retval; 3823 3824 retval = sctp_make_reconf(asoc, length); 3825 if (!retval) 3826 return NULL; 3827 3828 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3829 tsnresp.param_hdr.length = htons(length); 3830 3831 tsnresp.response_seq = htonl(sn); 3832 tsnresp.result = htonl(result); 3833 tsnresp.senders_next_tsn = htonl(sender_tsn); 3834 tsnresp.receivers_next_tsn = htonl(receiver_tsn); 3835 3836 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp); 3837 3838 return retval; 3839} 3840 3841bool sctp_verify_reconf(const struct sctp_association *asoc, 3842 struct sctp_chunk *chunk, 3843 struct sctp_paramhdr **errp) 3844{ 3845 struct sctp_reconf_chunk *hdr; 3846 union sctp_params param; 3847 __be16 last = 0; 3848 __u16 cnt = 0; 3849 3850 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; 3851 sctp_walk_params(param, hdr) { 3852 __u16 length = ntohs(param.p->length); 3853 3854 *errp = param.p; 3855 if (cnt++ > 2) 3856 return false; 3857 switch (param.p->type) { 3858 case SCTP_PARAM_RESET_OUT_REQUEST: 3859 if (length < sizeof(struct sctp_strreset_outreq) || 3860 (last && last != SCTP_PARAM_RESET_RESPONSE && 3861 last != SCTP_PARAM_RESET_IN_REQUEST)) 3862 return false; 3863 break; 3864 case SCTP_PARAM_RESET_IN_REQUEST: 3865 if (length < sizeof(struct sctp_strreset_inreq) || 3866 (last && last != SCTP_PARAM_RESET_OUT_REQUEST)) 3867 return false; 3868 break; 3869 case SCTP_PARAM_RESET_RESPONSE: 3870 if ((length != sizeof(struct sctp_strreset_resp) && 3871 length != sizeof(struct sctp_strreset_resptsn)) || 3872 (last && last != SCTP_PARAM_RESET_RESPONSE && 3873 last != SCTP_PARAM_RESET_OUT_REQUEST)) 3874 return false; 3875 break; 3876 case SCTP_PARAM_RESET_TSN_REQUEST: 3877 if (length != 3878 sizeof(struct sctp_strreset_tsnreq) || last) 3879 return false; 3880 break; 3881 case SCTP_PARAM_RESET_ADD_IN_STREAMS: 3882 if (length != sizeof(struct sctp_strreset_addstrm) || 3883 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS)) 3884 return false; 3885 break; 3886 case SCTP_PARAM_RESET_ADD_OUT_STREAMS: 3887 if (length != sizeof(struct sctp_strreset_addstrm) || 3888 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS)) 3889 return false; 3890 break; 3891 default: 3892 return false; 3893 } 3894 3895 last = param.p->type; 3896 } 3897 3898 return true; 3899}
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