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