1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* SCTP kernel implementation 3 * (C) Copyright IBM Corp. 2001, 2004 4 * Copyright (c) 1999-2000 Cisco, Inc. 5 * Copyright (c) 1999-2001 Motorola, Inc. 6 * Copyright (c) 2001-2002 Intel Corp. 7 * 8 * This file is part of the SCTP kernel implementation 9 * 10 * These functions work with the state functions in sctp_sm_statefuns.c 11 * to implement the state operations. These functions implement the 12 * steps which require modifying existing data structures. 13 * 14 * Please send any bug reports or fixes you make to the 15 * email address(es): 16 * lksctp developers <linux-sctp@vger.kernel.org> 17 * 18 * Written or modified by: 19 * La Monte H.P. Yarroll <piggy@acm.org> 20 * Karl Knutson <karl@athena.chicago.il.us> 21 * C. Robin <chris@hundredacre.ac.uk> 22 * Jon Grimm <jgrimm@us.ibm.com> 23 * Xingang Guo <xingang.guo@intel.com> 24 * Dajiang Zhang <dajiang.zhang@nokia.com> 25 * Sridhar Samudrala <sri@us.ibm.com> 26 * Daisy Chang <daisyc@us.ibm.com> 27 * Ardelle Fan <ardelle.fan@intel.com> 28 * Kevin Gao <kevin.gao@intel.com> 29 */ 30 31 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 32 33 #include <crypto/utils.h> 34 #include <linux/types.h> 35 #include <linux/kernel.h> 36 #include <linux/ip.h> 37 #include <linux/ipv6.h> 38 #include <linux/net.h> 39 #include <linux/inet.h> 40 #include <linux/scatterlist.h> 41 #include <linux/slab.h> 42 #include <net/sock.h> 43 44 #include <linux/skbuff.h> 45 #include <linux/random.h> /* for get_random_bytes */ 46 #include <net/sctp/sctp.h> 47 #include <net/sctp/sm.h> 48 49 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 50 __u8 type, __u8 flags, int paylen, 51 gfp_t gfp); 52 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 53 __u8 flags, int paylen, gfp_t gfp); 54 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 55 __u8 type, __u8 flags, int paylen, 56 gfp_t gfp); 57 static 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); 63 static int sctp_process_param(struct sctp_association *asoc, 64 union sctp_params param, 65 const union sctp_addr *peer_addr, 66 gfp_t gfp); 67 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 68 const void *data); 69 70 /* Control chunk destructor */ 71 static 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 97 static void sctp_control_set_owner_w(struct sctp_chunk *chunk) 98 { 99 struct sctp_association *asoc = chunk->asoc; 100 struct sk_buff *skb = chunk->skb; 101 102 /* TODO: properly account for control chunks. 103 * To do it right we'll need: 104 * 1) endpoint if association isn't known. 105 * 2) proper memory accounting. 106 * 107 * For now don't do anything for now. 108 */ 109 if (chunk->auth) { 110 chunk->shkey = asoc->shkey; 111 sctp_auth_shkey_hold(chunk->shkey); 112 } 113 skb->sk = asoc ? asoc->base.sk : NULL; 114 skb_shinfo(skb)->destructor_arg = chunk; 115 skb->destructor = sctp_control_release_owner; 116 } 117 118 /* RFC 2960 3.3.2 Initiation (INIT) (1) 119 * 120 * Note 2: The ECN capable field is reserved for future use of 121 * Explicit Congestion Notification. 122 */ 123 static const struct sctp_paramhdr ecap_param = { 124 SCTP_PARAM_ECN_CAPABLE, 125 cpu_to_be16(sizeof(struct sctp_paramhdr)), 126 }; 127 static const struct sctp_paramhdr prsctp_param = { 128 SCTP_PARAM_FWD_TSN_SUPPORT, 129 cpu_to_be16(sizeof(struct sctp_paramhdr)), 130 }; 131 132 /* A helper to initialize an op error inside a provided chunk, as most 133 * cause codes will be embedded inside an abort chunk. 134 */ 135 int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, 136 size_t paylen) 137 { 138 struct sctp_errhdr err; 139 __u16 len; 140 141 /* Cause code constants are now defined in network order. */ 142 err.cause = cause_code; 143 len = sizeof(err) + paylen; 144 err.length = htons(len); 145 146 if (skb_tailroom(chunk->skb) < len) 147 return -ENOSPC; 148 149 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(err), &err); 150 151 return 0; 152 } 153 154 /* 3.3.2 Initiation (INIT) (1) 155 * 156 * This chunk is used to initiate a SCTP association between two 157 * endpoints. The format of the INIT chunk is shown below: 158 * 159 * 0 1 2 3 160 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 161 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 162 * | Type = 1 | Chunk Flags | Chunk Length | 163 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 164 * | Initiate Tag | 165 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 166 * | Advertised Receiver Window Credit (a_rwnd) | 167 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 168 * | Number of Outbound Streams | Number of Inbound Streams | 169 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 170 * | Initial TSN | 171 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 172 * \ \ 173 * / Optional/Variable-Length Parameters / 174 * \ \ 175 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 176 * 177 * 178 * The INIT chunk contains the following parameters. Unless otherwise 179 * noted, each parameter MUST only be included once in the INIT chunk. 180 * 181 * Fixed Parameters Status 182 * ---------------------------------------------- 183 * Initiate Tag Mandatory 184 * Advertised Receiver Window Credit Mandatory 185 * Number of Outbound Streams Mandatory 186 * Number of Inbound Streams Mandatory 187 * Initial TSN Mandatory 188 * 189 * Variable Parameters Status Type Value 190 * ------------------------------------------------------------- 191 * IPv4 Address (Note 1) Optional 5 192 * IPv6 Address (Note 1) Optional 6 193 * Cookie Preservative Optional 9 194 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000) 195 * Host Name Address (Note 3) Optional 11 196 * Supported Address Types (Note 4) Optional 12 197 */ 198 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc, 199 const struct sctp_bind_addr *bp, 200 gfp_t gfp, int vparam_len) 201 { 202 struct sctp_supported_ext_param ext_param; 203 struct sctp_adaptation_ind_param aiparam; 204 struct sctp_paramhdr *auth_chunks = NULL; 205 struct sctp_paramhdr *auth_hmacs = NULL; 206 struct sctp_supported_addrs_param sat; 207 struct sctp_endpoint *ep = asoc->ep; 208 struct sctp_chunk *retval = NULL; 209 int num_types, addrs_len = 0; 210 struct sctp_inithdr init; 211 union sctp_params addrs; 212 struct sctp_sock *sp; 213 __u8 extensions[5]; 214 size_t chunksize; 215 __be16 types[2]; 216 int num_ext = 0; 217 218 /* RFC 2960 3.3.2 Initiation (INIT) (1) 219 * 220 * Note 1: The INIT chunks can contain multiple addresses that 221 * can be IPv4 and/or IPv6 in any combination. 222 */ 223 224 /* Convert the provided bind address list to raw format. */ 225 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp); 226 227 init.init_tag = htonl(asoc->c.my_vtag); 228 init.a_rwnd = htonl(asoc->rwnd); 229 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 230 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 231 init.initial_tsn = htonl(asoc->c.initial_tsn); 232 233 /* How many address types are needed? */ 234 sp = sctp_sk(asoc->base.sk); 235 num_types = sp->pf->supported_addrs(sp, types); 236 237 chunksize = sizeof(init) + addrs_len; 238 chunksize += SCTP_PAD4(SCTP_SAT_LEN(num_types)); 239 240 if (asoc->ep->ecn_enable) 241 chunksize += sizeof(ecap_param); 242 243 if (asoc->ep->prsctp_enable) 244 chunksize += sizeof(prsctp_param); 245 246 /* ADDIP: Section 4.2.7: 247 * An implementation supporting this extension [ADDIP] MUST list 248 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and 249 * INIT-ACK parameters. 250 */ 251 if (asoc->ep->asconf_enable) { 252 extensions[num_ext] = SCTP_CID_ASCONF; 253 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 254 num_ext += 2; 255 } 256 257 if (asoc->ep->reconf_enable) { 258 extensions[num_ext] = SCTP_CID_RECONF; 259 num_ext += 1; 260 } 261 262 if (sp->adaptation_ind) 263 chunksize += sizeof(aiparam); 264 265 if (asoc->ep->intl_enable) { 266 extensions[num_ext] = SCTP_CID_I_DATA; 267 num_ext += 1; 268 } 269 270 chunksize += vparam_len; 271 272 /* Account for AUTH related parameters */ 273 if (ep->auth_enable) { 274 /* Add random parameter length*/ 275 chunksize += sizeof(asoc->c.auth_random); 276 277 /* Add HMACS parameter length if any were defined */ 278 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; 279 if (auth_hmacs->length) 280 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 281 else 282 auth_hmacs = NULL; 283 284 /* Add CHUNKS parameter length */ 285 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; 286 if (auth_chunks->length) 287 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 288 else 289 auth_chunks = NULL; 290 291 extensions[num_ext] = SCTP_CID_AUTH; 292 num_ext += 1; 293 } 294 295 /* If we have any extensions to report, account for that */ 296 if (num_ext) 297 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext); 298 299 /* RFC 2960 3.3.2 Initiation (INIT) (1) 300 * 301 * Note 3: An INIT chunk MUST NOT contain more than one Host 302 * Name address parameter. Moreover, the sender of the INIT 303 * MUST NOT combine any other address types with the Host Name 304 * address in the INIT. The receiver of INIT MUST ignore any 305 * other address types if the Host Name address parameter is 306 * present in the received INIT chunk. 307 * 308 * PLEASE DO NOT FIXME [This version does not support Host Name.] 309 */ 310 311 retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp); 312 if (!retval) 313 goto nodata; 314 315 retval->subh.init_hdr = 316 sctp_addto_chunk(retval, sizeof(init), &init); 317 retval->param_hdr.v = 318 sctp_addto_chunk(retval, addrs_len, addrs.v); 319 320 /* RFC 2960 3.3.2 Initiation (INIT) (1) 321 * 322 * Note 4: This parameter, when present, specifies all the 323 * address types the sending endpoint can support. The absence 324 * of this parameter indicates that the sending endpoint can 325 * support any address type. 326 */ 327 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES; 328 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types)); 329 sctp_addto_chunk(retval, sizeof(sat), &sat); 330 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types); 331 332 if (asoc->ep->ecn_enable) 333 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 334 335 /* Add the supported extensions parameter. Be nice and add this 336 * fist before addiding the parameters for the extensions themselves 337 */ 338 if (num_ext) { 339 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 340 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext); 341 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); 342 sctp_addto_param(retval, num_ext, extensions); 343 } 344 345 if (asoc->ep->prsctp_enable) 346 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 347 348 if (sp->adaptation_ind) { 349 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 350 aiparam.param_hdr.length = htons(sizeof(aiparam)); 351 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 352 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 353 } 354 355 /* Add SCTP-AUTH chunks to the parameter list */ 356 if (ep->auth_enable) { 357 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random), 358 asoc->c.auth_random); 359 if (auth_hmacs) 360 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 361 auth_hmacs); 362 if (auth_chunks) 363 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 364 auth_chunks); 365 } 366 nodata: 367 kfree(addrs.v); 368 return retval; 369 } 370 371 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, 372 const struct sctp_chunk *chunk, 373 gfp_t gfp, int unkparam_len) 374 { 375 struct sctp_supported_ext_param ext_param; 376 struct sctp_adaptation_ind_param aiparam; 377 struct sctp_paramhdr *auth_chunks = NULL; 378 struct sctp_paramhdr *auth_random = NULL; 379 struct sctp_paramhdr *auth_hmacs = NULL; 380 struct sctp_chunk *retval = NULL; 381 struct sctp_cookie_param *cookie; 382 struct sctp_inithdr initack; 383 union sctp_params addrs; 384 struct sctp_sock *sp; 385 __u8 extensions[5]; 386 size_t chunksize; 387 int num_ext = 0; 388 int cookie_len; 389 int addrs_len; 390 391 /* Note: there may be no addresses to embed. */ 392 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp); 393 394 initack.init_tag = htonl(asoc->c.my_vtag); 395 initack.a_rwnd = htonl(asoc->rwnd); 396 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 397 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 398 initack.initial_tsn = htonl(asoc->c.initial_tsn); 399 400 /* FIXME: We really ought to build the cookie right 401 * into the packet instead of allocating more fresh memory. 402 */ 403 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len, 404 addrs.v, addrs_len); 405 if (!cookie) 406 goto nomem_cookie; 407 408 /* Calculate the total size of allocation, include the reserved 409 * space for reporting unknown parameters if it is specified. 410 */ 411 sp = sctp_sk(asoc->base.sk); 412 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len; 413 414 /* Tell peer that we'll do ECN only if peer advertised such cap. */ 415 if (asoc->peer.ecn_capable) 416 chunksize += sizeof(ecap_param); 417 418 if (asoc->peer.prsctp_capable) 419 chunksize += sizeof(prsctp_param); 420 421 if (asoc->peer.asconf_capable) { 422 extensions[num_ext] = SCTP_CID_ASCONF; 423 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 424 num_ext += 2; 425 } 426 427 if (asoc->peer.reconf_capable) { 428 extensions[num_ext] = SCTP_CID_RECONF; 429 num_ext += 1; 430 } 431 432 if (sp->adaptation_ind) 433 chunksize += sizeof(aiparam); 434 435 if (asoc->peer.intl_capable) { 436 extensions[num_ext] = SCTP_CID_I_DATA; 437 num_ext += 1; 438 } 439 440 if (asoc->peer.auth_capable) { 441 auth_random = (struct sctp_paramhdr *)asoc->c.auth_random; 442 chunksize += ntohs(auth_random->length); 443 444 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; 445 if (auth_hmacs->length) 446 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 447 else 448 auth_hmacs = NULL; 449 450 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; 451 if (auth_chunks->length) 452 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 453 else 454 auth_chunks = NULL; 455 456 extensions[num_ext] = SCTP_CID_AUTH; 457 num_ext += 1; 458 } 459 460 if (num_ext) 461 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext); 462 463 /* Now allocate and fill out the chunk. */ 464 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp); 465 if (!retval) 466 goto nomem_chunk; 467 468 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 469 * 470 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 471 * HEARTBEAT ACK, * etc.) to the same destination transport 472 * address from which it received the DATA or control chunk 473 * to which it is replying. 474 * 475 * [INIT ACK back to where the INIT came from.] 476 */ 477 if (chunk->transport) 478 retval->transport = 479 sctp_assoc_lookup_paddr(asoc, 480 &chunk->transport->ipaddr); 481 482 retval->subh.init_hdr = 483 sctp_addto_chunk(retval, sizeof(initack), &initack); 484 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); 485 sctp_addto_chunk(retval, cookie_len, cookie); 486 if (asoc->peer.ecn_capable) 487 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 488 if (num_ext) { 489 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 490 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext); 491 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); 492 sctp_addto_param(retval, num_ext, extensions); 493 } 494 if (asoc->peer.prsctp_capable) 495 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 496 497 if (sp->adaptation_ind) { 498 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 499 aiparam.param_hdr.length = htons(sizeof(aiparam)); 500 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 501 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 502 } 503 504 if (asoc->peer.auth_capable) { 505 sctp_addto_chunk(retval, ntohs(auth_random->length), 506 auth_random); 507 if (auth_hmacs) 508 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 509 auth_hmacs); 510 if (auth_chunks) 511 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 512 auth_chunks); 513 } 514 515 /* We need to remove the const qualifier at this point. */ 516 retval->asoc = (struct sctp_association *) asoc; 517 518 nomem_chunk: 519 kfree(cookie); 520 nomem_cookie: 521 kfree(addrs.v); 522 return retval; 523 } 524 525 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10): 526 * 527 * This chunk is used only during the initialization of an association. 528 * It is sent by the initiator of an association to its peer to complete 529 * the initialization process. This chunk MUST precede any DATA chunk 530 * sent within the association, but MAY be bundled with one or more DATA 531 * chunks in the same packet. 532 * 533 * 0 1 2 3 534 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 535 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 536 * | Type = 10 |Chunk Flags | Length | 537 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 538 * / Cookie / 539 * \ \ 540 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 541 * 542 * Chunk Flags: 8 bit 543 * 544 * Set to zero on transmit and ignored on receipt. 545 * 546 * Length: 16 bits (unsigned integer) 547 * 548 * Set to the size of the chunk in bytes, including the 4 bytes of 549 * the chunk header and the size of the Cookie. 550 * 551 * Cookie: variable size 552 * 553 * This field must contain the exact cookie received in the 554 * State Cookie parameter from the previous INIT ACK. 555 * 556 * An implementation SHOULD make the cookie as small as possible 557 * to insure interoperability. 558 */ 559 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, 560 const struct sctp_chunk *chunk) 561 { 562 struct sctp_chunk *retval; 563 int cookie_len; 564 void *cookie; 565 566 cookie = asoc->peer.cookie; 567 cookie_len = asoc->peer.cookie_len; 568 569 /* Build a cookie echo chunk. */ 570 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0, 571 cookie_len, GFP_ATOMIC); 572 if (!retval) 573 goto nodata; 574 retval->subh.cookie_hdr = 575 sctp_addto_chunk(retval, cookie_len, cookie); 576 577 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 578 * 579 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 580 * HEARTBEAT ACK, * etc.) to the same destination transport 581 * address from which it * received the DATA or control chunk 582 * to which it is replying. 583 * 584 * [COOKIE ECHO back to where the INIT ACK came from.] 585 */ 586 if (chunk) 587 retval->transport = chunk->transport; 588 589 nodata: 590 return retval; 591 } 592 593 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11): 594 * 595 * This chunk is used only during the initialization of an 596 * association. It is used to acknowledge the receipt of a COOKIE 597 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent 598 * within the association, but MAY be bundled with one or more DATA 599 * chunks or SACK chunk in the same SCTP packet. 600 * 601 * 0 1 2 3 602 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 603 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 604 * | Type = 11 |Chunk Flags | Length = 4 | 605 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 606 * 607 * Chunk Flags: 8 bits 608 * 609 * Set to zero on transmit and ignored on receipt. 610 */ 611 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, 612 const struct sctp_chunk *chunk) 613 { 614 struct sctp_chunk *retval; 615 616 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC); 617 618 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 619 * 620 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 621 * HEARTBEAT ACK, * etc.) to the same destination transport 622 * address from which it * received the DATA or control chunk 623 * to which it is replying. 624 * 625 * [COOKIE ACK back to where the COOKIE ECHO came from.] 626 */ 627 if (retval && chunk && chunk->transport) 628 retval->transport = 629 sctp_assoc_lookup_paddr(asoc, 630 &chunk->transport->ipaddr); 631 632 return retval; 633 } 634 635 /* 636 * Appendix A: Explicit Congestion Notification: 637 * CWR: 638 * 639 * RFC 2481 details a specific bit for a sender to send in the header of 640 * its next outbound TCP segment to indicate to its peer that it has 641 * reduced its congestion window. This is termed the CWR bit. For 642 * SCTP the same indication is made by including the CWR chunk. 643 * This chunk contains one data element, i.e. the TSN number that 644 * was sent in the ECNE chunk. This element represents the lowest 645 * TSN number in the datagram that was originally marked with the 646 * CE bit. 647 * 648 * 0 1 2 3 649 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 650 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 651 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 | 652 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 653 * | Lowest TSN Number | 654 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 655 * 656 * Note: The CWR is considered a Control chunk. 657 */ 658 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, 659 const __u32 lowest_tsn, 660 const struct sctp_chunk *chunk) 661 { 662 struct sctp_chunk *retval; 663 struct sctp_cwrhdr cwr; 664 665 cwr.lowest_tsn = htonl(lowest_tsn); 666 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0, 667 sizeof(cwr), GFP_ATOMIC); 668 669 if (!retval) 670 goto nodata; 671 672 retval->subh.ecn_cwr_hdr = 673 sctp_addto_chunk(retval, sizeof(cwr), &cwr); 674 675 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 676 * 677 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 678 * HEARTBEAT ACK, * etc.) to the same destination transport 679 * address from which it * received the DATA or control chunk 680 * to which it is replying. 681 * 682 * [Report a reduced congestion window back to where the ECNE 683 * came from.] 684 */ 685 if (chunk) 686 retval->transport = chunk->transport; 687 688 nodata: 689 return retval; 690 } 691 692 /* Make an ECNE chunk. This is a congestion experienced report. */ 693 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, 694 const __u32 lowest_tsn) 695 { 696 struct sctp_chunk *retval; 697 struct sctp_ecnehdr ecne; 698 699 ecne.lowest_tsn = htonl(lowest_tsn); 700 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0, 701 sizeof(ecne), GFP_ATOMIC); 702 if (!retval) 703 goto nodata; 704 retval->subh.ecne_hdr = 705 sctp_addto_chunk(retval, sizeof(ecne), &ecne); 706 707 nodata: 708 return retval; 709 } 710 711 /* Make a DATA chunk for the given association from the provided 712 * parameters. However, do not populate the data payload. 713 */ 714 struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc, 715 const struct sctp_sndrcvinfo *sinfo, 716 int len, __u8 flags, gfp_t gfp) 717 { 718 struct sctp_chunk *retval; 719 struct sctp_datahdr dp; 720 721 /* We assign the TSN as LATE as possible, not here when 722 * creating the chunk. 723 */ 724 memset(&dp, 0, sizeof(dp)); 725 dp.ppid = sinfo->sinfo_ppid; 726 dp.stream = htons(sinfo->sinfo_stream); 727 728 /* Set the flags for an unordered send. */ 729 if (sinfo->sinfo_flags & SCTP_UNORDERED) 730 flags |= SCTP_DATA_UNORDERED; 731 732 retval = sctp_make_data(asoc, flags, sizeof(dp) + len, gfp); 733 if (!retval) 734 return NULL; 735 736 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp); 737 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo)); 738 739 return retval; 740 } 741 742 /* Create a selective ackowledgement (SACK) for the given 743 * association. This reports on which TSN's we've seen to date, 744 * including duplicates and gaps. 745 */ 746 struct sctp_chunk *sctp_make_sack(struct sctp_association *asoc) 747 { 748 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; 749 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; 750 __u16 num_gabs, num_dup_tsns; 751 struct sctp_transport *trans; 752 struct sctp_chunk *retval; 753 struct sctp_sackhdr sack; 754 __u32 ctsn; 755 int len; 756 757 memset(gabs, 0, sizeof(gabs)); 758 ctsn = sctp_tsnmap_get_ctsn(map); 759 760 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn); 761 762 /* How much room is needed in the chunk? */ 763 num_gabs = sctp_tsnmap_num_gabs(map, gabs); 764 num_dup_tsns = sctp_tsnmap_num_dups(map); 765 766 /* Initialize the SACK header. */ 767 sack.cum_tsn_ack = htonl(ctsn); 768 sack.a_rwnd = htonl(asoc->a_rwnd); 769 sack.num_gap_ack_blocks = htons(num_gabs); 770 sack.num_dup_tsns = htons(num_dup_tsns); 771 772 len = sizeof(sack) 773 + sizeof(struct sctp_gap_ack_block) * num_gabs 774 + sizeof(__u32) * num_dup_tsns; 775 776 /* Create the chunk. */ 777 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC); 778 if (!retval) 779 goto nodata; 780 781 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 782 * 783 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 784 * HEARTBEAT ACK, etc.) to the same destination transport 785 * address from which it received the DATA or control chunk to 786 * which it is replying. This rule should also be followed if 787 * the endpoint is bundling DATA chunks together with the 788 * reply chunk. 789 * 790 * However, when acknowledging multiple DATA chunks received 791 * in packets from different source addresses in a single 792 * SACK, the SACK chunk may be transmitted to one of the 793 * destination transport addresses from which the DATA or 794 * control chunks being acknowledged were received. 795 * 796 * [BUG: We do not implement the following paragraph. 797 * Perhaps we should remember the last transport we used for a 798 * SACK and avoid that (if possible) if we have seen any 799 * duplicates. --piggy] 800 * 801 * When a receiver of a duplicate DATA chunk sends a SACK to a 802 * multi- homed endpoint it MAY be beneficial to vary the 803 * destination address and not use the source address of the 804 * DATA chunk. The reason being that receiving a duplicate 805 * from a multi-homed endpoint might indicate that the return 806 * path (as specified in the source address of the DATA chunk) 807 * for the SACK is broken. 808 * 809 * [Send to the address from which we last received a DATA chunk.] 810 */ 811 retval->transport = asoc->peer.last_data_from; 812 813 retval->subh.sack_hdr = 814 sctp_addto_chunk(retval, sizeof(sack), &sack); 815 816 /* Add the gap ack block information. */ 817 if (num_gabs) 818 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, 819 gabs); 820 821 /* Add the duplicate TSN information. */ 822 if (num_dup_tsns) { 823 asoc->stats.idupchunks += num_dup_tsns; 824 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, 825 sctp_tsnmap_get_dups(map)); 826 } 827 /* Once we have a sack generated, check to see what our sack 828 * generation is, if its 0, reset the transports to 0, and reset 829 * the association generation to 1 830 * 831 * The idea is that zero is never used as a valid generation for the 832 * association so no transport will match after a wrap event like this, 833 * Until the next sack 834 */ 835 if (++asoc->peer.sack_generation == 0) { 836 list_for_each_entry(trans, &asoc->peer.transport_addr_list, 837 transports) 838 trans->sack_generation = 0; 839 asoc->peer.sack_generation = 1; 840 } 841 nodata: 842 return retval; 843 } 844 845 /* Make a SHUTDOWN chunk. */ 846 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 847 const struct sctp_chunk *chunk) 848 { 849 struct sctp_shutdownhdr shut; 850 struct sctp_chunk *retval; 851 __u32 ctsn; 852 853 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 854 shut.cum_tsn_ack = htonl(ctsn); 855 856 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0, 857 sizeof(shut), GFP_ATOMIC); 858 if (!retval) 859 goto nodata; 860 861 retval->subh.shutdown_hdr = 862 sctp_addto_chunk(retval, sizeof(shut), &shut); 863 864 if (chunk) 865 retval->transport = chunk->transport; 866 nodata: 867 return retval; 868 } 869 870 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 871 const struct sctp_chunk *chunk) 872 { 873 struct sctp_chunk *retval; 874 875 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0, 876 GFP_ATOMIC); 877 878 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 879 * 880 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 881 * HEARTBEAT ACK, * etc.) to the same destination transport 882 * address from which it * received the DATA or control chunk 883 * to which it is replying. 884 * 885 * [ACK back to where the SHUTDOWN came from.] 886 */ 887 if (retval && chunk) 888 retval->transport = chunk->transport; 889 890 return retval; 891 } 892 893 struct sctp_chunk *sctp_make_shutdown_complete( 894 const struct sctp_association *asoc, 895 const struct sctp_chunk *chunk) 896 { 897 struct sctp_chunk *retval; 898 __u8 flags = 0; 899 900 /* Set the T-bit if we have no association (vtag will be 901 * reflected) 902 */ 903 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; 904 905 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 906 0, GFP_ATOMIC); 907 908 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 909 * 910 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 911 * HEARTBEAT ACK, * etc.) to the same destination transport 912 * address from which it * received the DATA or control chunk 913 * to which it is replying. 914 * 915 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK 916 * came from.] 917 */ 918 if (retval && chunk) 919 retval->transport = chunk->transport; 920 921 return retval; 922 } 923 924 /* Create an ABORT. Note that we set the T bit if we have no 925 * association, except when responding to an INIT (sctpimpguide 2.41). 926 */ 927 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 928 const struct sctp_chunk *chunk, 929 const size_t hint) 930 { 931 struct sctp_chunk *retval; 932 __u8 flags = 0; 933 934 /* Set the T-bit if we have no association and 'chunk' is not 935 * an INIT (vtag will be reflected). 936 */ 937 if (!asoc) { 938 if (chunk && chunk->chunk_hdr && 939 chunk->chunk_hdr->type == SCTP_CID_INIT) 940 flags = 0; 941 else 942 flags = SCTP_CHUNK_FLAG_T; 943 } 944 945 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint, 946 GFP_ATOMIC); 947 948 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 949 * 950 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 951 * HEARTBEAT ACK, * etc.) to the same destination transport 952 * address from which it * received the DATA or control chunk 953 * to which it is replying. 954 * 955 * [ABORT back to where the offender came from.] 956 */ 957 if (retval && chunk) 958 retval->transport = chunk->transport; 959 960 return retval; 961 } 962 963 /* Helper to create ABORT with a NO_USER_DATA error. */ 964 struct sctp_chunk *sctp_make_abort_no_data( 965 const struct sctp_association *asoc, 966 const struct sctp_chunk *chunk, 967 __u32 tsn) 968 { 969 struct sctp_chunk *retval; 970 __be32 payload; 971 972 retval = sctp_make_abort(asoc, chunk, 973 sizeof(struct sctp_errhdr) + sizeof(tsn)); 974 975 if (!retval) 976 goto no_mem; 977 978 /* Put the tsn back into network byte order. */ 979 payload = htonl(tsn); 980 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload)); 981 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload); 982 983 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 984 * 985 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 986 * HEARTBEAT ACK, * etc.) to the same destination transport 987 * address from which it * received the DATA or control chunk 988 * to which it is replying. 989 * 990 * [ABORT back to where the offender came from.] 991 */ 992 if (chunk) 993 retval->transport = chunk->transport; 994 995 no_mem: 996 return retval; 997 } 998 999 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ 1000 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 1001 struct msghdr *msg, 1002 size_t paylen) 1003 { 1004 struct sctp_chunk *retval; 1005 void *payload = NULL; 1006 int err; 1007 1008 retval = sctp_make_abort(asoc, NULL, 1009 sizeof(struct sctp_errhdr) + paylen); 1010 if (!retval) 1011 goto err_chunk; 1012 1013 if (paylen) { 1014 /* Put the msg_iov together into payload. */ 1015 payload = kmalloc(paylen, GFP_KERNEL); 1016 if (!payload) 1017 goto err_payload; 1018 1019 err = memcpy_from_msg(payload, msg, paylen); 1020 if (err < 0) 1021 goto err_copy; 1022 } 1023 1024 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); 1025 sctp_addto_chunk(retval, paylen, payload); 1026 1027 if (paylen) 1028 kfree(payload); 1029 1030 return retval; 1031 1032 err_copy: 1033 kfree(payload); 1034 err_payload: 1035 sctp_chunk_free(retval); 1036 retval = NULL; 1037 err_chunk: 1038 return retval; 1039 } 1040 1041 /* Append bytes to the end of a parameter. Will panic if chunk is not big 1042 * enough. 1043 */ 1044 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 1045 const void *data) 1046 { 1047 int chunklen = ntohs(chunk->chunk_hdr->length); 1048 void *target; 1049 1050 target = skb_put(chunk->skb, len); 1051 1052 if (data) 1053 memcpy(target, data, len); 1054 else 1055 memset(target, 0, len); 1056 1057 /* Adjust the chunk length field. */ 1058 chunk->chunk_hdr->length = htons(chunklen + len); 1059 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1060 1061 return target; 1062 } 1063 1064 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ 1065 struct sctp_chunk *sctp_make_abort_violation( 1066 const struct sctp_association *asoc, 1067 const struct sctp_chunk *chunk, 1068 const __u8 *payload, 1069 const size_t paylen) 1070 { 1071 struct sctp_chunk *retval; 1072 struct sctp_paramhdr phdr; 1073 1074 retval = sctp_make_abort(asoc, chunk, sizeof(struct sctp_errhdr) + 1075 paylen + sizeof(phdr)); 1076 if (!retval) 1077 goto end; 1078 1079 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen + 1080 sizeof(phdr)); 1081 1082 phdr.type = htons(chunk->chunk_hdr->type); 1083 phdr.length = chunk->chunk_hdr->length; 1084 sctp_addto_chunk(retval, paylen, payload); 1085 sctp_addto_param(retval, sizeof(phdr), &phdr); 1086 1087 end: 1088 return retval; 1089 } 1090 1091 struct sctp_chunk *sctp_make_violation_paramlen( 1092 const struct sctp_association *asoc, 1093 const struct sctp_chunk *chunk, 1094 struct sctp_paramhdr *param) 1095 { 1096 static const char error[] = "The following parameter had invalid length:"; 1097 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr) + 1098 sizeof(*param); 1099 struct sctp_chunk *retval; 1100 1101 retval = sctp_make_abort(asoc, chunk, payload_len); 1102 if (!retval) 1103 goto nodata; 1104 1105 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, 1106 sizeof(error) + sizeof(*param)); 1107 sctp_addto_chunk(retval, sizeof(error), error); 1108 sctp_addto_param(retval, sizeof(*param), param); 1109 1110 nodata: 1111 return retval; 1112 } 1113 1114 struct sctp_chunk *sctp_make_violation_max_retrans( 1115 const struct sctp_association *asoc, 1116 const struct sctp_chunk *chunk) 1117 { 1118 static const char error[] = "Association exceeded its max_retrans count"; 1119 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr); 1120 struct sctp_chunk *retval; 1121 1122 retval = sctp_make_abort(asoc, chunk, payload_len); 1123 if (!retval) 1124 goto nodata; 1125 1126 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error)); 1127 sctp_addto_chunk(retval, sizeof(error), error); 1128 1129 nodata: 1130 return retval; 1131 } 1132 1133 struct sctp_chunk *sctp_make_new_encap_port(const struct sctp_association *asoc, 1134 const struct sctp_chunk *chunk) 1135 { 1136 struct sctp_new_encap_port_hdr nep; 1137 struct sctp_chunk *retval; 1138 1139 retval = sctp_make_abort(asoc, chunk, 1140 sizeof(struct sctp_errhdr) + sizeof(nep)); 1141 if (!retval) 1142 goto nodata; 1143 1144 sctp_init_cause(retval, SCTP_ERROR_NEW_ENCAP_PORT, sizeof(nep)); 1145 nep.cur_port = SCTP_INPUT_CB(chunk->skb)->encap_port; 1146 nep.new_port = chunk->transport->encap_port; 1147 sctp_addto_chunk(retval, sizeof(nep), &nep); 1148 1149 nodata: 1150 return retval; 1151 } 1152 1153 /* Make a HEARTBEAT chunk. */ 1154 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1155 const struct sctp_transport *transport, 1156 __u32 probe_size) 1157 { 1158 struct sctp_sender_hb_info hbinfo = {}; 1159 struct sctp_chunk *retval; 1160 1161 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, 1162 sizeof(hbinfo), GFP_ATOMIC); 1163 1164 if (!retval) 1165 goto nodata; 1166 1167 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; 1168 hbinfo.param_hdr.length = htons(sizeof(hbinfo)); 1169 hbinfo.daddr = transport->ipaddr; 1170 hbinfo.sent_at = jiffies; 1171 hbinfo.hb_nonce = transport->hb_nonce; 1172 hbinfo.probe_size = probe_size; 1173 1174 /* Cast away the 'const', as this is just telling the chunk 1175 * what transport it belongs to. 1176 */ 1177 retval->transport = (struct sctp_transport *) transport; 1178 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo), 1179 &hbinfo); 1180 retval->pmtu_probe = !!probe_size; 1181 1182 nodata: 1183 return retval; 1184 } 1185 1186 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1187 const struct sctp_chunk *chunk, 1188 const void *payload, 1189 const size_t paylen) 1190 { 1191 struct sctp_chunk *retval; 1192 1193 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen, 1194 GFP_ATOMIC); 1195 if (!retval) 1196 goto nodata; 1197 1198 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1199 1200 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1201 * 1202 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1203 * HEARTBEAT ACK, * etc.) to the same destination transport 1204 * address from which it * received the DATA or control chunk 1205 * to which it is replying. 1206 * 1207 * [HBACK back to where the HEARTBEAT came from.] 1208 */ 1209 if (chunk) 1210 retval->transport = chunk->transport; 1211 1212 nodata: 1213 return retval; 1214 } 1215 1216 /* RFC4820 3. Padding Chunk (PAD) 1217 * 0 1 2 3 1218 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 1219 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1220 * | Type = 0x84 | Flags=0 | Length | 1221 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1222 * | | 1223 * \ Padding Data / 1224 * / \ 1225 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1226 */ 1227 struct sctp_chunk *sctp_make_pad(const struct sctp_association *asoc, int len) 1228 { 1229 struct sctp_chunk *retval; 1230 1231 retval = sctp_make_control(asoc, SCTP_CID_PAD, 0, len, GFP_ATOMIC); 1232 if (!retval) 1233 return NULL; 1234 1235 skb_put_zero(retval->skb, len); 1236 retval->chunk_hdr->length = htons(ntohs(retval->chunk_hdr->length) + len); 1237 retval->chunk_end = skb_tail_pointer(retval->skb); 1238 1239 return retval; 1240 } 1241 1242 /* Create an Operation Error chunk with the specified space reserved. 1243 * This routine can be used for containing multiple causes in the chunk. 1244 */ 1245 static struct sctp_chunk *sctp_make_op_error_space( 1246 const struct sctp_association *asoc, 1247 const struct sctp_chunk *chunk, 1248 size_t size) 1249 { 1250 struct sctp_chunk *retval; 1251 1252 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0, 1253 sizeof(struct sctp_errhdr) + size, 1254 GFP_ATOMIC); 1255 if (!retval) 1256 goto nodata; 1257 1258 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1259 * 1260 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1261 * HEARTBEAT ACK, etc.) to the same destination transport 1262 * address from which it received the DATA or control chunk 1263 * to which it is replying. 1264 * 1265 */ 1266 if (chunk) 1267 retval->transport = chunk->transport; 1268 1269 nodata: 1270 return retval; 1271 } 1272 1273 /* Create an Operation Error chunk of a fixed size, specifically, 1274 * min(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) - overheads. 1275 * This is a helper function to allocate an error chunk for those 1276 * invalid parameter codes in which we may not want to report all the 1277 * errors, if the incoming chunk is large. If it can't fit in a single 1278 * packet, we ignore it. 1279 */ 1280 static inline struct sctp_chunk *sctp_make_op_error_limited( 1281 const struct sctp_association *asoc, 1282 const struct sctp_chunk *chunk) 1283 { 1284 size_t size = SCTP_DEFAULT_MAXSEGMENT; 1285 struct sctp_sock *sp = NULL; 1286 1287 if (asoc) { 1288 size = min_t(size_t, size, asoc->pathmtu); 1289 sp = sctp_sk(asoc->base.sk); 1290 } 1291 1292 size = sctp_mtu_payload(sp, size, sizeof(struct sctp_errhdr)); 1293 1294 return sctp_make_op_error_space(asoc, chunk, size); 1295 } 1296 1297 /* Create an Operation Error chunk. */ 1298 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1299 const struct sctp_chunk *chunk, 1300 __be16 cause_code, const void *payload, 1301 size_t paylen, size_t reserve_tail) 1302 { 1303 struct sctp_chunk *retval; 1304 1305 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); 1306 if (!retval) 1307 goto nodata; 1308 1309 sctp_init_cause(retval, cause_code, paylen + reserve_tail); 1310 sctp_addto_chunk(retval, paylen, payload); 1311 if (reserve_tail) 1312 sctp_addto_param(retval, reserve_tail, NULL); 1313 1314 nodata: 1315 return retval; 1316 } 1317 1318 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc, 1319 __u16 key_id) 1320 { 1321 struct sctp_authhdr auth_hdr; 1322 const struct sctp_hmac *hmac_desc; 1323 struct sctp_chunk *retval; 1324 1325 /* Get the first hmac that the peer told us to use */ 1326 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1327 if (unlikely(!hmac_desc)) 1328 return NULL; 1329 1330 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0, 1331 hmac_desc->hmac_len + sizeof(auth_hdr), 1332 GFP_ATOMIC); 1333 if (!retval) 1334 return NULL; 1335 1336 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1337 auth_hdr.shkey_id = htons(key_id); 1338 1339 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr), 1340 &auth_hdr); 1341 1342 skb_put_zero(retval->skb, hmac_desc->hmac_len); 1343 1344 /* Adjust the chunk header to include the empty MAC */ 1345 retval->chunk_hdr->length = 1346 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1347 retval->chunk_end = skb_tail_pointer(retval->skb); 1348 1349 return retval; 1350 } 1351 1352 1353 /******************************************************************** 1354 * 2nd Level Abstractions 1355 ********************************************************************/ 1356 1357 /* Turn an skb into a chunk. 1358 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1359 * 1360 * sctpimpguide-05.txt Section 2.8.2 1361 * M1) Each time a new DATA chunk is transmitted 1362 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1363 * 'TSN.Missing.Report' count will be used to determine missing chunks 1364 * and when to fast retransmit. 1365 * 1366 */ 1367 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1368 const struct sctp_association *asoc, 1369 struct sock *sk, gfp_t gfp) 1370 { 1371 struct sctp_chunk *retval; 1372 1373 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp); 1374 1375 if (!retval) 1376 goto nodata; 1377 if (!sk) 1378 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb); 1379 1380 INIT_LIST_HEAD(&retval->list); 1381 retval->skb = skb; 1382 retval->asoc = (struct sctp_association *)asoc; 1383 retval->singleton = 1; 1384 1385 retval->fast_retransmit = SCTP_CAN_FRTX; 1386 1387 /* Polish the bead hole. */ 1388 INIT_LIST_HEAD(&retval->transmitted_list); 1389 INIT_LIST_HEAD(&retval->frag_list); 1390 SCTP_DBG_OBJCNT_INC(chunk); 1391 refcount_set(&retval->refcnt, 1); 1392 1393 nodata: 1394 return retval; 1395 } 1396 1397 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1398 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1399 union sctp_addr *dest) 1400 { 1401 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1402 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1403 } 1404 1405 /* Extract the source address from a chunk. */ 1406 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1407 { 1408 /* If we have a known transport, use that. */ 1409 if (chunk->transport) { 1410 return &chunk->transport->ipaddr; 1411 } else { 1412 /* Otherwise, extract it from the IP header. */ 1413 return &chunk->source; 1414 } 1415 } 1416 1417 /* Create a new chunk, setting the type and flags headers from the 1418 * arguments, reserving enough space for a 'paylen' byte payload. 1419 */ 1420 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 1421 __u8 type, __u8 flags, int paylen, 1422 gfp_t gfp) 1423 { 1424 struct sctp_chunkhdr *chunk_hdr; 1425 struct sctp_chunk *retval; 1426 struct sk_buff *skb; 1427 struct sock *sk; 1428 int chunklen; 1429 1430 chunklen = SCTP_PAD4(sizeof(*chunk_hdr) + paylen); 1431 if (chunklen > SCTP_MAX_CHUNK_LEN) 1432 goto nodata; 1433 1434 /* No need to allocate LL here, as this is only a chunk. */ 1435 skb = alloc_skb(chunklen, gfp); 1436 if (!skb) 1437 goto nodata; 1438 1439 /* Make room for the chunk header. */ 1440 chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr)); 1441 chunk_hdr->type = type; 1442 chunk_hdr->flags = flags; 1443 chunk_hdr->length = htons(sizeof(*chunk_hdr)); 1444 1445 sk = asoc ? asoc->base.sk : NULL; 1446 retval = sctp_chunkify(skb, asoc, sk, gfp); 1447 if (!retval) { 1448 kfree_skb(skb); 1449 goto nodata; 1450 } 1451 1452 retval->chunk_hdr = chunk_hdr; 1453 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr); 1454 1455 /* Determine if the chunk needs to be authenticated */ 1456 if (sctp_auth_send_cid(type, asoc)) 1457 retval->auth = 1; 1458 1459 return retval; 1460 nodata: 1461 return NULL; 1462 } 1463 1464 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 1465 __u8 flags, int paylen, gfp_t gfp) 1466 { 1467 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp); 1468 } 1469 1470 struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc, 1471 __u8 flags, int paylen, gfp_t gfp) 1472 { 1473 return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp); 1474 } 1475 1476 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 1477 __u8 type, __u8 flags, int paylen, 1478 gfp_t gfp) 1479 { 1480 struct sctp_chunk *chunk; 1481 1482 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp); 1483 if (chunk) 1484 sctp_control_set_owner_w(chunk); 1485 1486 return chunk; 1487 } 1488 1489 /* Release the memory occupied by a chunk. */ 1490 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1491 { 1492 BUG_ON(!list_empty(&chunk->list)); 1493 list_del_init(&chunk->transmitted_list); 1494 1495 consume_skb(chunk->skb); 1496 consume_skb(chunk->auth_chunk); 1497 1498 SCTP_DBG_OBJCNT_DEC(chunk); 1499 kmem_cache_free(sctp_chunk_cachep, chunk); 1500 } 1501 1502 /* Possibly, free the chunk. */ 1503 void sctp_chunk_free(struct sctp_chunk *chunk) 1504 { 1505 /* Release our reference on the message tracker. */ 1506 if (chunk->msg) 1507 sctp_datamsg_put(chunk->msg); 1508 1509 sctp_chunk_put(chunk); 1510 } 1511 1512 /* Grab a reference to the chunk. */ 1513 void sctp_chunk_hold(struct sctp_chunk *ch) 1514 { 1515 refcount_inc(&ch->refcnt); 1516 } 1517 1518 /* Release a reference to the chunk. */ 1519 void sctp_chunk_put(struct sctp_chunk *ch) 1520 { 1521 if (refcount_dec_and_test(&ch->refcnt)) 1522 sctp_chunk_destroy(ch); 1523 } 1524 1525 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1526 * enough. 1527 */ 1528 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1529 { 1530 int chunklen = ntohs(chunk->chunk_hdr->length); 1531 int padlen = SCTP_PAD4(chunklen) - chunklen; 1532 void *target; 1533 1534 skb_put_zero(chunk->skb, padlen); 1535 target = skb_put_data(chunk->skb, data, len); 1536 1537 /* Adjust the chunk length field. */ 1538 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1539 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1540 1541 return target; 1542 } 1543 1544 /* Append bytes from user space to the end of a chunk. Will panic if 1545 * chunk is not big enough. 1546 * Returns a kernel err value. 1547 */ 1548 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len, 1549 struct iov_iter *from) 1550 { 1551 void *target; 1552 1553 /* Make room in chunk for data. */ 1554 target = skb_put(chunk->skb, len); 1555 1556 /* Copy data (whole iovec) into chunk */ 1557 if (!copy_from_iter_full(target, len, from)) 1558 return -EFAULT; 1559 1560 /* Adjust the chunk length field. */ 1561 chunk->chunk_hdr->length = 1562 htons(ntohs(chunk->chunk_hdr->length) + len); 1563 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1564 1565 return 0; 1566 } 1567 1568 /* Helper function to assign a TSN if needed. This assumes that both 1569 * the data_hdr and association have already been assigned. 1570 */ 1571 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1572 { 1573 struct sctp_stream *stream; 1574 struct sctp_chunk *lchunk; 1575 struct sctp_datamsg *msg; 1576 __u16 ssn, sid; 1577 1578 if (chunk->has_ssn) 1579 return; 1580 1581 /* All fragments will be on the same stream */ 1582 sid = ntohs(chunk->subh.data_hdr->stream); 1583 stream = &chunk->asoc->stream; 1584 1585 /* Now assign the sequence number to the entire message. 1586 * All fragments must have the same stream sequence number. 1587 */ 1588 msg = chunk->msg; 1589 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1590 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1591 ssn = 0; 1592 } else { 1593 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1594 ssn = sctp_ssn_next(stream, out, sid); 1595 else 1596 ssn = sctp_ssn_peek(stream, out, sid); 1597 } 1598 1599 lchunk->subh.data_hdr->ssn = htons(ssn); 1600 lchunk->has_ssn = 1; 1601 } 1602 } 1603 1604 /* Helper function to assign a TSN if needed. This assumes that both 1605 * the data_hdr and association have already been assigned. 1606 */ 1607 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1608 { 1609 if (!chunk->has_tsn) { 1610 /* This is the last possible instant to 1611 * assign a TSN. 1612 */ 1613 chunk->subh.data_hdr->tsn = 1614 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1615 chunk->has_tsn = 1; 1616 } 1617 } 1618 1619 /* Create a CLOSED association to use with an incoming packet. */ 1620 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1621 struct sctp_chunk *chunk, 1622 gfp_t gfp) 1623 { 1624 struct sctp_association *asoc; 1625 enum sctp_scope scope; 1626 struct sk_buff *skb; 1627 1628 /* Create the bare association. */ 1629 scope = sctp_scope(sctp_source(chunk)); 1630 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1631 if (!asoc) 1632 goto nodata; 1633 asoc->temp = 1; 1634 skb = chunk->skb; 1635 /* Create an entry for the source address of the packet. */ 1636 SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1); 1637 1638 nodata: 1639 return asoc; 1640 } 1641 1642 /* Build a cookie representing asoc. 1643 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1644 */ 1645 static struct sctp_cookie_param *sctp_pack_cookie( 1646 const struct sctp_endpoint *ep, 1647 const struct sctp_association *asoc, 1648 const struct sctp_chunk *init_chunk, 1649 int *cookie_len, const __u8 *raw_addrs, 1650 int addrs_len) 1651 { 1652 struct sctp_signed_cookie *cookie; 1653 struct sctp_cookie_param *retval; 1654 int headersize, bodysize; 1655 1656 /* Header size is static data prior to the actual cookie, including 1657 * any padding. 1658 */ 1659 headersize = sizeof(struct sctp_paramhdr) + 1660 (sizeof(struct sctp_signed_cookie) - 1661 sizeof(struct sctp_cookie)); 1662 bodysize = sizeof(struct sctp_cookie) 1663 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1664 1665 /* Pad out the cookie to a multiple to make the signature 1666 * functions simpler to write. 1667 */ 1668 if (bodysize % SCTP_COOKIE_MULTIPLE) 1669 bodysize += SCTP_COOKIE_MULTIPLE 1670 - (bodysize % SCTP_COOKIE_MULTIPLE); 1671 *cookie_len = headersize + bodysize; 1672 1673 /* Clear this memory since we are sending this data structure 1674 * out on the network. 1675 */ 1676 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1677 if (!retval) { 1678 *cookie_len = 0; 1679 return NULL; 1680 } 1681 1682 cookie = (struct sctp_signed_cookie *) retval->body; 1683 1684 /* Set up the parameter header. */ 1685 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1686 retval->p.length = htons(*cookie_len); 1687 1688 /* Copy the cookie part of the association itself. */ 1689 cookie->c = asoc->c; 1690 /* Save the raw address list length in the cookie. */ 1691 cookie->c.raw_addr_list_len = addrs_len; 1692 1693 /* Remember PR-SCTP capability. */ 1694 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1695 1696 /* Save adaptation indication in the cookie. */ 1697 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1698 1699 /* Set an expiration time for the cookie. */ 1700 cookie->c.expiration = ktime_add(asoc->cookie_life, 1701 ktime_get_real()); 1702 1703 /* Copy the peer's init packet. */ 1704 memcpy(cookie + 1, init_chunk->chunk_hdr, 1705 ntohs(init_chunk->chunk_hdr->length)); 1706 1707 /* Copy the raw local address list of the association. */ 1708 memcpy((__u8 *)(cookie + 1) + 1709 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1710 1711 /* Sign the cookie, if cookie authentication is enabled. */ 1712 if (sctp_sk(ep->base.sk)->cookie_auth_enable) { 1713 static_assert(sizeof(cookie->mac) == SHA256_DIGEST_SIZE); 1714 hmac_sha256(&ep->cookie_auth_key, (const u8 *)&cookie->c, 1715 bodysize, cookie->mac); 1716 } 1717 1718 return retval; 1719 } 1720 1721 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1722 struct sctp_association *sctp_unpack_cookie( 1723 const struct sctp_endpoint *ep, 1724 const struct sctp_association *asoc, 1725 struct sctp_chunk *chunk, gfp_t gfp, 1726 int *error, struct sctp_chunk **errp) 1727 { 1728 struct sctp_association *retval = NULL; 1729 int headersize, bodysize, fixed_size; 1730 struct sctp_signed_cookie *cookie; 1731 struct sk_buff *skb = chunk->skb; 1732 struct sctp_cookie *bear_cookie; 1733 struct sctp_chunkhdr *ch; 1734 enum sctp_scope scope; 1735 unsigned int len; 1736 ktime_t kt; 1737 1738 /* Header size is static data prior to the actual cookie, including 1739 * any padding. 1740 */ 1741 headersize = sizeof(struct sctp_chunkhdr) + 1742 (sizeof(struct sctp_signed_cookie) - 1743 sizeof(struct sctp_cookie)); 1744 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1745 fixed_size = headersize + sizeof(struct sctp_cookie); 1746 1747 /* Verify that the chunk looks like it even has a cookie. 1748 * There must be enough room for our cookie and our peer's 1749 * INIT chunk. 1750 */ 1751 len = ntohs(chunk->chunk_hdr->length); 1752 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1753 goto malformed; 1754 1755 /* Verify that the cookie has been padded out. */ 1756 if (bodysize % SCTP_COOKIE_MULTIPLE) 1757 goto malformed; 1758 1759 /* Process the cookie. */ 1760 cookie = chunk->subh.cookie_hdr; 1761 bear_cookie = &cookie->c; 1762 1763 ch = (struct sctp_chunkhdr *)(bear_cookie + 1); 1764 if (ntohs(ch->length) > len - fixed_size) 1765 goto malformed; 1766 1767 /* Verify the cookie's MAC, if cookie authentication is enabled. */ 1768 if (sctp_sk(ep->base.sk)->cookie_auth_enable) { 1769 u8 mac[SHA256_DIGEST_SIZE]; 1770 1771 hmac_sha256(&ep->cookie_auth_key, (const u8 *)bear_cookie, 1772 bodysize, mac); 1773 static_assert(sizeof(cookie->mac) == sizeof(mac)); 1774 if (crypto_memneq(mac, cookie->mac, sizeof(mac))) { 1775 *error = -SCTP_IERROR_BAD_SIG; 1776 goto fail; 1777 } 1778 } 1779 1780 /* IG Section 2.35.2: 1781 * 3) Compare the port numbers and the verification tag contained 1782 * within the COOKIE ECHO chunk to the actual port numbers and the 1783 * verification tag within the SCTP common header of the received 1784 * packet. If these values do not match the packet MUST be silently 1785 * discarded, 1786 */ 1787 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1788 *error = -SCTP_IERROR_BAD_TAG; 1789 goto fail; 1790 } 1791 1792 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1793 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1794 *error = -SCTP_IERROR_BAD_PORTS; 1795 goto fail; 1796 } 1797 1798 /* Check to see if the cookie is stale. If there is already 1799 * an association, there is no need to check cookie's expiration 1800 * for init collision case of lost COOKIE ACK. 1801 * If skb has been timestamped, then use the stamp, otherwise 1802 * use current time. This introduces a small possibility that 1803 * a cookie may be considered expired, but this would only slow 1804 * down the new association establishment instead of every packet. 1805 */ 1806 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1807 kt = skb_get_ktime(skb); 1808 else 1809 kt = ktime_get_real(); 1810 1811 if (!asoc && ktime_before(bear_cookie->expiration, kt)) { 1812 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); 1813 __be32 n = htonl(usecs); 1814 1815 /* 1816 * Section 3.3.10.3 Stale Cookie Error (3) 1817 * 1818 * Cause of error 1819 * --------------- 1820 * Stale Cookie Error: Indicates the receipt of a valid State 1821 * Cookie that has expired. 1822 */ 1823 *errp = sctp_make_op_error(asoc, chunk, 1824 SCTP_ERROR_STALE_COOKIE, &n, 1825 sizeof(n), 0); 1826 if (*errp) 1827 *error = -SCTP_IERROR_STALE_COOKIE; 1828 else 1829 *error = -SCTP_IERROR_NOMEM; 1830 1831 goto fail; 1832 } 1833 1834 /* Make a new base association. */ 1835 scope = sctp_scope(sctp_source(chunk)); 1836 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1837 if (!retval) { 1838 *error = -SCTP_IERROR_NOMEM; 1839 goto fail; 1840 } 1841 1842 /* Set up our peer's port number. */ 1843 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1844 1845 /* Populate the association from the cookie. */ 1846 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1847 1848 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1849 GFP_ATOMIC) < 0) { 1850 *error = -SCTP_IERROR_NOMEM; 1851 goto fail; 1852 } 1853 1854 /* Also, add the destination address. */ 1855 if (list_empty(&retval->base.bind_addr.address_list)) { 1856 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1857 sizeof(chunk->dest), SCTP_ADDR_SRC, 1858 GFP_ATOMIC); 1859 } 1860 1861 retval->next_tsn = retval->c.initial_tsn; 1862 retval->ctsn_ack_point = retval->next_tsn - 1; 1863 retval->addip_serial = retval->c.initial_tsn; 1864 retval->strreset_outseq = retval->c.initial_tsn; 1865 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1866 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1867 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1868 1869 /* The INIT stuff will be done by the side effects. */ 1870 return retval; 1871 1872 fail: 1873 if (retval) 1874 sctp_association_free(retval); 1875 1876 return NULL; 1877 1878 malformed: 1879 /* Yikes! The packet is either corrupt or deliberately 1880 * malformed. 1881 */ 1882 *error = -SCTP_IERROR_MALFORMED; 1883 goto fail; 1884 } 1885 1886 /******************************************************************** 1887 * 3rd Level Abstractions 1888 ********************************************************************/ 1889 1890 struct __sctp_missing { 1891 __be32 num_missing; 1892 __be16 type; 1893 } __packed; 1894 1895 /* 1896 * Report a missing mandatory parameter. 1897 */ 1898 static int sctp_process_missing_param(const struct sctp_association *asoc, 1899 enum sctp_param paramtype, 1900 struct sctp_chunk *chunk, 1901 struct sctp_chunk **errp) 1902 { 1903 struct __sctp_missing report; 1904 __u16 len; 1905 1906 len = SCTP_PAD4(sizeof(report)); 1907 1908 /* Make an ERROR chunk, preparing enough room for 1909 * returning multiple unknown parameters. 1910 */ 1911 if (!*errp) 1912 *errp = sctp_make_op_error_space(asoc, chunk, len); 1913 1914 if (*errp) { 1915 report.num_missing = htonl(1); 1916 report.type = paramtype; 1917 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1918 sizeof(report)); 1919 sctp_addto_chunk(*errp, sizeof(report), &report); 1920 } 1921 1922 /* Stop processing this chunk. */ 1923 return 0; 1924 } 1925 1926 /* Report an Invalid Mandatory Parameter. */ 1927 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1928 struct sctp_chunk *chunk, 1929 struct sctp_chunk **errp) 1930 { 1931 /* Invalid Mandatory Parameter Error has no payload. */ 1932 1933 if (!*errp) 1934 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1935 1936 if (*errp) 1937 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1938 1939 /* Stop processing this chunk. */ 1940 return 0; 1941 } 1942 1943 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1944 struct sctp_paramhdr *param, 1945 const struct sctp_chunk *chunk, 1946 struct sctp_chunk **errp) 1947 { 1948 /* This is a fatal error. Any accumulated non-fatal errors are 1949 * not reported. 1950 */ 1951 if (*errp) 1952 sctp_chunk_free(*errp); 1953 1954 /* Create an error chunk and fill it in with our payload. */ 1955 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1956 1957 return 0; 1958 } 1959 1960 1961 /* Do not attempt to handle the HOST_NAME parm. However, do 1962 * send back an indicator to the peer. 1963 */ 1964 static int sctp_process_hn_param(const struct sctp_association *asoc, 1965 union sctp_params param, 1966 struct sctp_chunk *chunk, 1967 struct sctp_chunk **errp) 1968 { 1969 __u16 len = ntohs(param.p->length); 1970 1971 /* Processing of the HOST_NAME parameter will generate an 1972 * ABORT. If we've accumulated any non-fatal errors, they 1973 * would be unrecognized parameters and we should not include 1974 * them in the ABORT. 1975 */ 1976 if (*errp) 1977 sctp_chunk_free(*errp); 1978 1979 *errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_DNS_FAILED, 1980 param.v, len, 0); 1981 1982 /* Stop processing this chunk. */ 1983 return 0; 1984 } 1985 1986 static int sctp_verify_ext_param(struct net *net, 1987 const struct sctp_endpoint *ep, 1988 union sctp_params param) 1989 { 1990 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 1991 int have_asconf = 0; 1992 int have_auth = 0; 1993 int i; 1994 1995 for (i = 0; i < num_ext; i++) { 1996 switch (param.ext->chunks[i]) { 1997 case SCTP_CID_AUTH: 1998 have_auth = 1; 1999 break; 2000 case SCTP_CID_ASCONF: 2001 case SCTP_CID_ASCONF_ACK: 2002 have_asconf = 1; 2003 break; 2004 } 2005 } 2006 2007 /* ADD-IP Security: The draft requires us to ABORT or ignore the 2008 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 2009 * only if ADD-IP is turned on and we are not backward-compatible 2010 * mode. 2011 */ 2012 if (net->sctp.addip_noauth) 2013 return 1; 2014 2015 if (ep->asconf_enable && !have_auth && have_asconf) 2016 return 0; 2017 2018 return 1; 2019 } 2020 2021 static void sctp_process_ext_param(struct sctp_association *asoc, 2022 union sctp_params param) 2023 { 2024 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2025 int i; 2026 2027 for (i = 0; i < num_ext; i++) { 2028 switch (param.ext->chunks[i]) { 2029 case SCTP_CID_RECONF: 2030 if (asoc->ep->reconf_enable) 2031 asoc->peer.reconf_capable = 1; 2032 break; 2033 case SCTP_CID_FWD_TSN: 2034 if (asoc->ep->prsctp_enable) 2035 asoc->peer.prsctp_capable = 1; 2036 break; 2037 case SCTP_CID_AUTH: 2038 /* if the peer reports AUTH, assume that he 2039 * supports AUTH. 2040 */ 2041 if (asoc->ep->auth_enable) 2042 asoc->peer.auth_capable = 1; 2043 break; 2044 case SCTP_CID_ASCONF: 2045 case SCTP_CID_ASCONF_ACK: 2046 if (asoc->ep->asconf_enable) 2047 asoc->peer.asconf_capable = 1; 2048 break; 2049 case SCTP_CID_I_DATA: 2050 if (asoc->ep->intl_enable) 2051 asoc->peer.intl_capable = 1; 2052 break; 2053 default: 2054 break; 2055 } 2056 } 2057 } 2058 2059 /* RFC 3.2.1 & the Implementers Guide 2.2. 2060 * 2061 * The Parameter Types are encoded such that the 2062 * highest-order two bits specify the action that must be 2063 * taken if the processing endpoint does not recognize the 2064 * Parameter Type. 2065 * 2066 * 00 - Stop processing this parameter; do not process any further 2067 * parameters within this chunk 2068 * 2069 * 01 - Stop processing this parameter, do not process any further 2070 * parameters within this chunk, and report the unrecognized 2071 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2072 * 2073 * 10 - Skip this parameter and continue processing. 2074 * 2075 * 11 - Skip this parameter and continue processing but 2076 * report the unrecognized parameter in an 2077 * 'Unrecognized Parameter' ERROR chunk. 2078 * 2079 * Return value: 2080 * SCTP_IERROR_NO_ERROR - continue with the chunk 2081 * SCTP_IERROR_ERROR - stop and report an error. 2082 * SCTP_IERROR_NOMEME - out of memory. 2083 */ 2084 static enum sctp_ierror sctp_process_unk_param( 2085 const struct sctp_association *asoc, 2086 union sctp_params param, 2087 struct sctp_chunk *chunk, 2088 struct sctp_chunk **errp) 2089 { 2090 int retval = SCTP_IERROR_NO_ERROR; 2091 2092 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2093 case SCTP_PARAM_ACTION_DISCARD: 2094 retval = SCTP_IERROR_ERROR; 2095 break; 2096 case SCTP_PARAM_ACTION_SKIP: 2097 break; 2098 case SCTP_PARAM_ACTION_DISCARD_ERR: 2099 retval = SCTP_IERROR_ERROR; 2100 fallthrough; 2101 case SCTP_PARAM_ACTION_SKIP_ERR: 2102 /* Make an ERROR chunk, preparing enough room for 2103 * returning multiple unknown parameters. 2104 */ 2105 if (!*errp) { 2106 *errp = sctp_make_op_error_limited(asoc, chunk); 2107 if (!*errp) { 2108 /* If there is no memory for generating the 2109 * ERROR report as specified, an ABORT will be 2110 * triggered to the peer and the association 2111 * won't be established. 2112 */ 2113 retval = SCTP_IERROR_NOMEM; 2114 break; 2115 } 2116 } 2117 2118 if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2119 ntohs(param.p->length))) 2120 sctp_addto_chunk(*errp, ntohs(param.p->length), 2121 param.v); 2122 break; 2123 default: 2124 break; 2125 } 2126 2127 return retval; 2128 } 2129 2130 /* Verify variable length parameters 2131 * Return values: 2132 * SCTP_IERROR_ABORT - trigger an ABORT 2133 * SCTP_IERROR_NOMEM - out of memory (abort) 2134 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2135 * SCTP_IERROR_NO_ERROR - continue with the chunk 2136 */ 2137 static enum sctp_ierror sctp_verify_param(struct net *net, 2138 const struct sctp_endpoint *ep, 2139 const struct sctp_association *asoc, 2140 union sctp_params param, 2141 enum sctp_cid cid, 2142 struct sctp_chunk *chunk, 2143 struct sctp_chunk **err_chunk) 2144 { 2145 struct sctp_hmac_algo_param *hmacs; 2146 int retval = SCTP_IERROR_NO_ERROR; 2147 __u16 n_elt, id = 0; 2148 int i; 2149 2150 /* FIXME - This routine is not looking at each parameter per the 2151 * chunk type, i.e., unrecognized parameters should be further 2152 * identified based on the chunk id. 2153 */ 2154 2155 switch (param.p->type) { 2156 case SCTP_PARAM_IPV4_ADDRESS: 2157 case SCTP_PARAM_IPV6_ADDRESS: 2158 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2159 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2160 case SCTP_PARAM_STATE_COOKIE: 2161 case SCTP_PARAM_HEARTBEAT_INFO: 2162 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2163 case SCTP_PARAM_ECN_CAPABLE: 2164 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2165 break; 2166 2167 case SCTP_PARAM_SUPPORTED_EXT: 2168 if (!sctp_verify_ext_param(net, ep, param)) 2169 return SCTP_IERROR_ABORT; 2170 break; 2171 2172 case SCTP_PARAM_SET_PRIMARY: 2173 if (!ep->asconf_enable) 2174 goto unhandled; 2175 2176 if (ntohs(param.p->length) < sizeof(struct sctp_addip_param) + 2177 sizeof(struct sctp_paramhdr)) { 2178 sctp_process_inv_paramlength(asoc, param.p, 2179 chunk, err_chunk); 2180 retval = SCTP_IERROR_ABORT; 2181 } 2182 break; 2183 2184 case SCTP_PARAM_HOST_NAME_ADDRESS: 2185 /* This param has been Deprecated, send ABORT. */ 2186 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2187 retval = SCTP_IERROR_ABORT; 2188 break; 2189 2190 case SCTP_PARAM_FWD_TSN_SUPPORT: 2191 if (ep->prsctp_enable) 2192 break; 2193 goto unhandled; 2194 2195 case SCTP_PARAM_RANDOM: 2196 if (!ep->auth_enable) 2197 goto unhandled; 2198 2199 /* SCTP-AUTH: Secion 6.1 2200 * If the random number is not 32 byte long the association 2201 * MUST be aborted. The ABORT chunk SHOULD contain the error 2202 * cause 'Protocol Violation'. 2203 */ 2204 if (SCTP_AUTH_RANDOM_LENGTH != ntohs(param.p->length) - 2205 sizeof(struct sctp_paramhdr)) { 2206 sctp_process_inv_paramlength(asoc, param.p, 2207 chunk, err_chunk); 2208 retval = SCTP_IERROR_ABORT; 2209 } 2210 break; 2211 2212 case SCTP_PARAM_CHUNKS: 2213 if (!ep->auth_enable) 2214 goto unhandled; 2215 2216 /* SCTP-AUTH: Section 3.2 2217 * The CHUNKS parameter MUST be included once in the INIT or 2218 * INIT-ACK chunk if the sender wants to receive authenticated 2219 * chunks. Its maximum length is 260 bytes. 2220 */ 2221 if (260 < ntohs(param.p->length)) { 2222 sctp_process_inv_paramlength(asoc, param.p, 2223 chunk, err_chunk); 2224 retval = SCTP_IERROR_ABORT; 2225 } 2226 break; 2227 2228 case SCTP_PARAM_HMAC_ALGO: 2229 if (!ep->auth_enable) 2230 goto unhandled; 2231 2232 hmacs = (struct sctp_hmac_algo_param *)param.p; 2233 n_elt = (ntohs(param.p->length) - 2234 sizeof(struct sctp_paramhdr)) >> 1; 2235 2236 /* SCTP-AUTH: Section 6.1 2237 * The HMAC algorithm based on SHA-1 MUST be supported and 2238 * included in the HMAC-ALGO parameter. 2239 */ 2240 for (i = 0; i < n_elt; i++) { 2241 id = ntohs(hmacs->hmac_ids[i]); 2242 2243 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2244 break; 2245 } 2246 2247 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2248 sctp_process_inv_paramlength(asoc, param.p, chunk, 2249 err_chunk); 2250 retval = SCTP_IERROR_ABORT; 2251 } 2252 break; 2253 unhandled: 2254 default: 2255 pr_debug("%s: unrecognized param:%d for chunk:%d\n", 2256 __func__, ntohs(param.p->type), cid); 2257 2258 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2259 break; 2260 } 2261 return retval; 2262 } 2263 2264 /* Verify the INIT packet before we process it. */ 2265 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 2266 const struct sctp_association *asoc, enum sctp_cid cid, 2267 struct sctp_init_chunk *peer_init, 2268 struct sctp_chunk *chunk, struct sctp_chunk **errp) 2269 { 2270 union sctp_params param; 2271 bool has_cookie = false; 2272 int result; 2273 2274 /* Check for missing mandatory parameters. Note: Initial TSN is 2275 * also mandatory, but is not checked here since the valid range 2276 * is 0..2**32-1. RFC4960, section 3.3.3. 2277 */ 2278 if (peer_init->init_hdr.num_outbound_streams == 0 || 2279 peer_init->init_hdr.num_inbound_streams == 0 || 2280 peer_init->init_hdr.init_tag == 0 || 2281 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) 2282 return sctp_process_inv_mandatory(asoc, chunk, errp); 2283 2284 sctp_walk_params(param, peer_init) { 2285 if (param.p->type == SCTP_PARAM_STATE_COOKIE) 2286 has_cookie = true; 2287 } 2288 2289 /* There is a possibility that a parameter length was bad and 2290 * in that case we would have stoped walking the parameters. 2291 * The current param.p would point at the bad one. 2292 * Current consensus on the mailing list is to generate a PROTOCOL 2293 * VIOLATION error. We build the ERROR chunk here and let the normal 2294 * error handling code build and send the packet. 2295 */ 2296 if (param.v != (void *)chunk->chunk_end) 2297 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2298 2299 /* The only missing mandatory param possible today is 2300 * the state cookie for an INIT-ACK chunk. 2301 */ 2302 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2303 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2304 chunk, errp); 2305 2306 /* Verify all the variable length parameters */ 2307 sctp_walk_params(param, peer_init) { 2308 result = sctp_verify_param(net, ep, asoc, param, cid, 2309 chunk, errp); 2310 switch (result) { 2311 case SCTP_IERROR_ABORT: 2312 case SCTP_IERROR_NOMEM: 2313 return 0; 2314 case SCTP_IERROR_ERROR: 2315 return 1; 2316 case SCTP_IERROR_NO_ERROR: 2317 default: 2318 break; 2319 } 2320 2321 } /* for (loop through all parameters) */ 2322 2323 return 1; 2324 } 2325 2326 /* Unpack the parameters in an INIT packet into an association. 2327 * Returns 0 on failure, else success. 2328 * FIXME: This is an association method. 2329 */ 2330 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2331 const union sctp_addr *peer_addr, 2332 struct sctp_init_chunk *peer_init, gfp_t gfp) 2333 { 2334 struct sctp_transport *transport; 2335 struct list_head *pos, *temp; 2336 union sctp_params param; 2337 union sctp_addr addr; 2338 struct sctp_af *af; 2339 int src_match = 0; 2340 2341 /* We must include the address that the INIT packet came from. 2342 * This is the only address that matters for an INIT packet. 2343 * When processing a COOKIE ECHO, we retrieve the from address 2344 * of the INIT from the cookie. 2345 */ 2346 2347 /* This implementation defaults to making the first transport 2348 * added as the primary transport. The source address seems to 2349 * be a better choice than any of the embedded addresses. 2350 */ 2351 asoc->encap_port = SCTP_INPUT_CB(chunk->skb)->encap_port; 2352 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2353 goto nomem; 2354 2355 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2356 src_match = 1; 2357 2358 /* Process the initialization parameters. */ 2359 sctp_walk_params(param, peer_init) { 2360 if (!src_match && 2361 (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2362 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2363 af = sctp_get_af_specific(param_type2af(param.p->type)); 2364 if (!af->from_addr_param(&addr, param.addr, 2365 chunk->sctp_hdr->source, 0)) 2366 continue; 2367 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2368 src_match = 1; 2369 } 2370 2371 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2372 goto clean_up; 2373 } 2374 2375 /* source address of chunk may not match any valid address */ 2376 if (!src_match) 2377 goto clean_up; 2378 2379 /* AUTH: After processing the parameters, make sure that we 2380 * have all the required info to potentially do authentications. 2381 */ 2382 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2383 !asoc->peer.peer_hmacs)) 2384 asoc->peer.auth_capable = 0; 2385 2386 /* In a non-backward compatible mode, if the peer claims 2387 * support for ADD-IP but not AUTH, the ADD-IP spec states 2388 * that we MUST ABORT the association. Section 6. The section 2389 * also give us an option to silently ignore the packet, which 2390 * is what we'll do here. 2391 */ 2392 if (!asoc->base.net->sctp.addip_noauth && 2393 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2394 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2395 SCTP_PARAM_DEL_IP | 2396 SCTP_PARAM_SET_PRIMARY); 2397 asoc->peer.asconf_capable = 0; 2398 goto clean_up; 2399 } 2400 2401 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2402 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2403 transport = list_entry(pos, struct sctp_transport, transports); 2404 if (transport->state == SCTP_UNKNOWN) { 2405 sctp_assoc_rm_peer(asoc, transport); 2406 } 2407 } 2408 2409 /* The fixed INIT headers are always in network byte 2410 * order. 2411 */ 2412 asoc->peer.i.init_tag = 2413 ntohl(peer_init->init_hdr.init_tag); 2414 asoc->peer.i.a_rwnd = 2415 ntohl(peer_init->init_hdr.a_rwnd); 2416 asoc->peer.i.num_outbound_streams = 2417 ntohs(peer_init->init_hdr.num_outbound_streams); 2418 asoc->peer.i.num_inbound_streams = 2419 ntohs(peer_init->init_hdr.num_inbound_streams); 2420 asoc->peer.i.initial_tsn = 2421 ntohl(peer_init->init_hdr.initial_tsn); 2422 2423 asoc->strreset_inseq = asoc->peer.i.initial_tsn; 2424 2425 /* Apply the upper bounds for output streams based on peer's 2426 * number of inbound streams. 2427 */ 2428 if (asoc->c.sinit_num_ostreams > 2429 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2430 asoc->c.sinit_num_ostreams = 2431 ntohs(peer_init->init_hdr.num_inbound_streams); 2432 } 2433 2434 if (asoc->c.sinit_max_instreams > 2435 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2436 asoc->c.sinit_max_instreams = 2437 ntohs(peer_init->init_hdr.num_outbound_streams); 2438 } 2439 2440 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2441 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2442 2443 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2444 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2445 2446 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2447 * high (for example, implementations MAY use the size of the receiver 2448 * advertised window). 2449 */ 2450 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2451 transports) { 2452 transport->ssthresh = asoc->peer.i.a_rwnd; 2453 } 2454 2455 /* Set up the TSN tracking pieces. */ 2456 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2457 asoc->peer.i.initial_tsn, gfp)) 2458 goto clean_up; 2459 2460 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2461 * 2462 * The stream sequence number in all the streams shall start 2463 * from 0 when the association is established. Also, when the 2464 * stream sequence number reaches the value 65535 the next 2465 * stream sequence number shall be set to 0. 2466 */ 2467 2468 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams, 2469 asoc->c.sinit_max_instreams, gfp)) 2470 goto clean_up; 2471 2472 /* Update frag_point when stream_interleave may get changed. */ 2473 sctp_assoc_update_frag_point(asoc); 2474 2475 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp)) 2476 goto clean_up; 2477 2478 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2479 * 2480 * When an endpoint has an ASCONF signaled change to be sent to the 2481 * remote endpoint it should do the following: 2482 * ... 2483 * A2) A serial number should be assigned to the Chunk. The serial 2484 * number should be a monotonically increasing number. All serial 2485 * numbers are defined to be initialized at the start of the 2486 * association to the same value as the Initial TSN. 2487 */ 2488 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2489 return 1; 2490 2491 clean_up: 2492 /* Release the transport structures. */ 2493 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2494 transport = list_entry(pos, struct sctp_transport, transports); 2495 if (transport->state != SCTP_ACTIVE) 2496 sctp_assoc_rm_peer(asoc, transport); 2497 } 2498 2499 nomem: 2500 return 0; 2501 } 2502 2503 2504 /* Update asoc with the option described in param. 2505 * 2506 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2507 * 2508 * asoc is the association to update. 2509 * param is the variable length parameter to use for update. 2510 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2511 * If the current packet is an INIT we want to minimize the amount of 2512 * work we do. In particular, we should not build transport 2513 * structures for the addresses. 2514 */ 2515 static int sctp_process_param(struct sctp_association *asoc, 2516 union sctp_params param, 2517 const union sctp_addr *peer_addr, 2518 gfp_t gfp) 2519 { 2520 struct sctp_endpoint *ep = asoc->ep; 2521 union sctp_addr_param *addr_param; 2522 struct net *net = asoc->base.net; 2523 struct sctp_transport *t; 2524 enum sctp_scope scope; 2525 union sctp_addr addr; 2526 struct sctp_af *af; 2527 int retval = 1, i; 2528 u32 stale; 2529 __u16 sat; 2530 2531 /* We maintain all INIT parameters in network byte order all the 2532 * time. This allows us to not worry about whether the parameters 2533 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2534 */ 2535 switch (param.p->type) { 2536 case SCTP_PARAM_IPV6_ADDRESS: 2537 if (PF_INET6 != asoc->base.sk->sk_family) 2538 break; 2539 goto do_addr_param; 2540 2541 case SCTP_PARAM_IPV4_ADDRESS: 2542 /* v4 addresses are not allowed on v6-only socket */ 2543 if (ipv6_only_sock(asoc->base.sk)) 2544 break; 2545 do_addr_param: 2546 af = sctp_get_af_specific(param_type2af(param.p->type)); 2547 if (!af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0)) 2548 break; 2549 scope = sctp_scope(peer_addr); 2550 if (sctp_in_scope(net, &addr, scope)) 2551 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2552 return 0; 2553 break; 2554 2555 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2556 if (!net->sctp.cookie_preserve_enable) 2557 break; 2558 2559 stale = ntohl(param.life->lifespan_increment); 2560 2561 /* Suggested Cookie Life span increment's unit is msec, 2562 * (1/1000sec). 2563 */ 2564 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale); 2565 break; 2566 2567 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2568 /* Turn off the default values first so we'll know which 2569 * ones are really set by the peer. 2570 */ 2571 asoc->peer.ipv4_address = 0; 2572 asoc->peer.ipv6_address = 0; 2573 2574 /* Assume that peer supports the address family 2575 * by which it sends a packet. 2576 */ 2577 if (peer_addr->sa.sa_family == AF_INET6) 2578 asoc->peer.ipv6_address = 1; 2579 else if (peer_addr->sa.sa_family == AF_INET) 2580 asoc->peer.ipv4_address = 1; 2581 2582 /* Cycle through address types; avoid divide by 0. */ 2583 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2584 if (sat) 2585 sat /= sizeof(__u16); 2586 2587 for (i = 0; i < sat; ++i) { 2588 switch (param.sat->types[i]) { 2589 case SCTP_PARAM_IPV4_ADDRESS: 2590 asoc->peer.ipv4_address = 1; 2591 break; 2592 2593 case SCTP_PARAM_IPV6_ADDRESS: 2594 if (PF_INET6 == asoc->base.sk->sk_family) 2595 asoc->peer.ipv6_address = 1; 2596 break; 2597 2598 default: /* Just ignore anything else. */ 2599 break; 2600 } 2601 } 2602 break; 2603 2604 case SCTP_PARAM_STATE_COOKIE: 2605 asoc->peer.cookie_len = 2606 ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2607 kfree(asoc->peer.cookie); 2608 asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp); 2609 if (!asoc->peer.cookie) 2610 retval = 0; 2611 break; 2612 2613 case SCTP_PARAM_HEARTBEAT_INFO: 2614 /* Would be odd to receive, but it causes no problems. */ 2615 break; 2616 2617 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2618 /* Rejected during verify stage. */ 2619 break; 2620 2621 case SCTP_PARAM_ECN_CAPABLE: 2622 if (asoc->ep->ecn_enable) { 2623 asoc->peer.ecn_capable = 1; 2624 break; 2625 } 2626 /* Fall Through */ 2627 goto fall_through; 2628 2629 2630 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2631 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2632 break; 2633 2634 case SCTP_PARAM_SET_PRIMARY: 2635 if (!ep->asconf_enable) 2636 goto fall_through; 2637 2638 addr_param = param.v + sizeof(struct sctp_addip_param); 2639 2640 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 2641 if (!af) 2642 break; 2643 2644 if (!af->from_addr_param(&addr, addr_param, 2645 htons(asoc->peer.port), 0)) 2646 break; 2647 2648 if (!af->addr_valid(&addr, NULL, NULL)) 2649 break; 2650 2651 t = sctp_assoc_lookup_paddr(asoc, &addr); 2652 if (!t) 2653 break; 2654 2655 sctp_assoc_set_primary(asoc, t); 2656 break; 2657 2658 case SCTP_PARAM_SUPPORTED_EXT: 2659 sctp_process_ext_param(asoc, param); 2660 break; 2661 2662 case SCTP_PARAM_FWD_TSN_SUPPORT: 2663 if (asoc->ep->prsctp_enable) { 2664 asoc->peer.prsctp_capable = 1; 2665 break; 2666 } 2667 /* Fall Through */ 2668 goto fall_through; 2669 2670 case SCTP_PARAM_RANDOM: 2671 if (!ep->auth_enable) 2672 goto fall_through; 2673 2674 /* Save peer's random parameter */ 2675 kfree(asoc->peer.peer_random); 2676 asoc->peer.peer_random = kmemdup(param.p, 2677 ntohs(param.p->length), gfp); 2678 if (!asoc->peer.peer_random) { 2679 retval = 0; 2680 break; 2681 } 2682 break; 2683 2684 case SCTP_PARAM_HMAC_ALGO: 2685 if (!ep->auth_enable) 2686 goto fall_through; 2687 2688 /* Save peer's HMAC list */ 2689 kfree(asoc->peer.peer_hmacs); 2690 asoc->peer.peer_hmacs = kmemdup(param.p, 2691 ntohs(param.p->length), gfp); 2692 if (!asoc->peer.peer_hmacs) { 2693 retval = 0; 2694 break; 2695 } 2696 2697 /* Set the default HMAC the peer requested*/ 2698 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2699 break; 2700 2701 case SCTP_PARAM_CHUNKS: 2702 if (!ep->auth_enable) 2703 goto fall_through; 2704 2705 kfree(asoc->peer.peer_chunks); 2706 asoc->peer.peer_chunks = kmemdup(param.p, 2707 ntohs(param.p->length), gfp); 2708 if (!asoc->peer.peer_chunks) 2709 retval = 0; 2710 break; 2711 fall_through: 2712 default: 2713 /* Any unrecognized parameters should have been caught 2714 * and handled by sctp_verify_param() which should be 2715 * called prior to this routine. Simply log the error 2716 * here. 2717 */ 2718 pr_debug("%s: ignoring param:%d for association:%p.\n", 2719 __func__, ntohs(param.p->type), asoc); 2720 break; 2721 } 2722 2723 return retval; 2724 } 2725 2726 /* Select a new verification tag. */ 2727 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2728 { 2729 /* I believe that this random number generator complies with RFC1750. 2730 * A tag of 0 is reserved for special cases (e.g. INIT). 2731 */ 2732 __u32 x; 2733 2734 do { 2735 x = get_random_u32(); 2736 } while (x == 0); 2737 2738 return x; 2739 } 2740 2741 /* Select an initial TSN to send during startup. */ 2742 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2743 { 2744 __u32 retval; 2745 2746 retval = get_random_u32(); 2747 return retval; 2748 } 2749 2750 /* 2751 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2752 * 0 1 2 3 2753 * 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 2754 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2755 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2756 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2757 * | Serial Number | 2758 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2759 * | Address Parameter | 2760 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2761 * | ASCONF Parameter #1 | 2762 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2763 * \ \ 2764 * / .... / 2765 * \ \ 2766 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2767 * | ASCONF Parameter #N | 2768 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2769 * 2770 * Address Parameter and other parameter will not be wrapped in this function 2771 */ 2772 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2773 union sctp_addr *addr, 2774 int vparam_len) 2775 { 2776 struct sctp_addiphdr asconf; 2777 struct sctp_chunk *retval; 2778 int length = sizeof(asconf) + vparam_len; 2779 union sctp_addr_param addrparam; 2780 int addrlen; 2781 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2782 2783 addrlen = af->to_addr_param(addr, &addrparam); 2784 if (!addrlen) 2785 return NULL; 2786 length += addrlen; 2787 2788 /* Create the chunk. */ 2789 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length, 2790 GFP_ATOMIC); 2791 if (!retval) 2792 return NULL; 2793 2794 asconf.serial = htonl(asoc->addip_serial++); 2795 2796 retval->subh.addip_hdr = 2797 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2798 retval->param_hdr.v = 2799 sctp_addto_chunk(retval, addrlen, &addrparam); 2800 2801 return retval; 2802 } 2803 2804 /* ADDIP 2805 * 3.2.1 Add IP Address 2806 * 0 1 2 3 2807 * 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 2808 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2809 * | Type = 0xC001 | Length = Variable | 2810 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2811 * | ASCONF-Request Correlation ID | 2812 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2813 * | Address Parameter | 2814 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2815 * 2816 * 3.2.2 Delete IP Address 2817 * 0 1 2 3 2818 * 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 2819 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2820 * | Type = 0xC002 | Length = Variable | 2821 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2822 * | ASCONF-Request Correlation ID | 2823 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2824 * | Address Parameter | 2825 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2826 * 2827 */ 2828 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2829 union sctp_addr *laddr, 2830 struct sockaddr *addrs, 2831 int addrcnt, __be16 flags) 2832 { 2833 union sctp_addr_param addr_param; 2834 struct sctp_addip_param param; 2835 int paramlen = sizeof(param); 2836 struct sctp_chunk *retval; 2837 int addr_param_len = 0; 2838 union sctp_addr *addr; 2839 int totallen = 0, i; 2840 int del_pickup = 0; 2841 struct sctp_af *af; 2842 void *addr_buf; 2843 2844 /* Get total length of all the address parameters. */ 2845 addr_buf = addrs; 2846 for (i = 0; i < addrcnt; i++) { 2847 addr = addr_buf; 2848 af = sctp_get_af_specific(addr->v4.sin_family); 2849 addr_param_len = af->to_addr_param(addr, &addr_param); 2850 2851 totallen += paramlen; 2852 totallen += addr_param_len; 2853 2854 addr_buf += af->sockaddr_len; 2855 if (asoc->asconf_addr_del_pending && !del_pickup) { 2856 /* reuse the parameter length from the same scope one */ 2857 totallen += paramlen; 2858 totallen += addr_param_len; 2859 del_pickup = 1; 2860 2861 pr_debug("%s: picked same-scope del_pending addr, " 2862 "totallen for all addresses is %d\n", 2863 __func__, totallen); 2864 } 2865 } 2866 2867 /* Create an asconf chunk with the required length. */ 2868 retval = sctp_make_asconf(asoc, laddr, totallen); 2869 if (!retval) 2870 return NULL; 2871 2872 /* Add the address parameters to the asconf chunk. */ 2873 addr_buf = addrs; 2874 for (i = 0; i < addrcnt; i++) { 2875 addr = addr_buf; 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 = flags; 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 addr_buf += af->sockaddr_len; 2886 } 2887 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2888 addr = asoc->asconf_addr_del_pending; 2889 af = sctp_get_af_specific(addr->v4.sin_family); 2890 addr_param_len = af->to_addr_param(addr, &addr_param); 2891 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2892 param.param_hdr.length = htons(paramlen + addr_param_len); 2893 param.crr_id = htonl(i); 2894 2895 sctp_addto_chunk(retval, paramlen, ¶m); 2896 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2897 } 2898 return retval; 2899 } 2900 2901 /* ADDIP 2902 * 3.2.4 Set Primary IP Address 2903 * 0 1 2 3 2904 * 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 2905 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2906 * | Type =0xC004 | Length = Variable | 2907 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2908 * | ASCONF-Request Correlation ID | 2909 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2910 * | Address Parameter | 2911 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2912 * 2913 * Create an ASCONF chunk with Set Primary IP address parameter. 2914 */ 2915 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2916 union sctp_addr *addr) 2917 { 2918 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2919 union sctp_addr_param addrparam; 2920 struct sctp_addip_param param; 2921 struct sctp_chunk *retval; 2922 int len = sizeof(param); 2923 int addrlen; 2924 2925 addrlen = af->to_addr_param(addr, &addrparam); 2926 if (!addrlen) 2927 return NULL; 2928 len += addrlen; 2929 2930 /* Create the chunk and make asconf header. */ 2931 retval = sctp_make_asconf(asoc, addr, len); 2932 if (!retval) 2933 return NULL; 2934 2935 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2936 param.param_hdr.length = htons(len); 2937 param.crr_id = 0; 2938 2939 sctp_addto_chunk(retval, sizeof(param), ¶m); 2940 sctp_addto_chunk(retval, addrlen, &addrparam); 2941 2942 return retval; 2943 } 2944 2945 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2946 * 0 1 2 3 2947 * 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 2948 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2949 * | Type = 0x80 | Chunk Flags | Chunk Length | 2950 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2951 * | Serial Number | 2952 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2953 * | ASCONF Parameter Response#1 | 2954 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2955 * \ \ 2956 * / .... / 2957 * \ \ 2958 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2959 * | ASCONF Parameter Response#N | 2960 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2961 * 2962 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2963 */ 2964 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2965 __u32 serial, int vparam_len) 2966 { 2967 struct sctp_addiphdr asconf; 2968 struct sctp_chunk *retval; 2969 int length = sizeof(asconf) + vparam_len; 2970 2971 /* Create the chunk. */ 2972 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length, 2973 GFP_ATOMIC); 2974 if (!retval) 2975 return NULL; 2976 2977 asconf.serial = htonl(serial); 2978 2979 retval->subh.addip_hdr = 2980 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2981 2982 return retval; 2983 } 2984 2985 /* Add response parameters to an ASCONF_ACK chunk. */ 2986 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2987 __be16 err_code, 2988 struct sctp_addip_param *asconf_param) 2989 { 2990 struct sctp_addip_param ack_param; 2991 struct sctp_errhdr err_param; 2992 int asconf_param_len = 0; 2993 int err_param_len = 0; 2994 __be16 response_type; 2995 2996 if (SCTP_ERROR_NO_ERROR == err_code) { 2997 response_type = SCTP_PARAM_SUCCESS_REPORT; 2998 } else { 2999 response_type = SCTP_PARAM_ERR_CAUSE; 3000 err_param_len = sizeof(err_param); 3001 if (asconf_param) 3002 asconf_param_len = 3003 ntohs(asconf_param->param_hdr.length); 3004 } 3005 3006 /* Add Success Indication or Error Cause Indication parameter. */ 3007 ack_param.param_hdr.type = response_type; 3008 ack_param.param_hdr.length = htons(sizeof(ack_param) + 3009 err_param_len + 3010 asconf_param_len); 3011 ack_param.crr_id = crr_id; 3012 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 3013 3014 if (SCTP_ERROR_NO_ERROR == err_code) 3015 return; 3016 3017 /* Add Error Cause parameter. */ 3018 err_param.cause = err_code; 3019 err_param.length = htons(err_param_len + asconf_param_len); 3020 sctp_addto_chunk(chunk, err_param_len, &err_param); 3021 3022 /* Add the failed TLV copied from ASCONF chunk. */ 3023 if (asconf_param) 3024 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 3025 } 3026 3027 /* Process a asconf parameter. */ 3028 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 3029 struct sctp_chunk *asconf, 3030 struct sctp_addip_param *asconf_param) 3031 { 3032 union sctp_addr_param *addr_param; 3033 struct sctp_transport *peer; 3034 union sctp_addr addr; 3035 struct sctp_af *af; 3036 3037 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3038 3039 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 3040 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 3041 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 3042 return SCTP_ERROR_UNKNOWN_PARAM; 3043 3044 switch (addr_param->p.type) { 3045 case SCTP_PARAM_IPV6_ADDRESS: 3046 if (!asoc->peer.ipv6_address) 3047 return SCTP_ERROR_DNS_FAILED; 3048 break; 3049 case SCTP_PARAM_IPV4_ADDRESS: 3050 if (!asoc->peer.ipv4_address) 3051 return SCTP_ERROR_DNS_FAILED; 3052 break; 3053 default: 3054 return SCTP_ERROR_DNS_FAILED; 3055 } 3056 3057 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3058 if (unlikely(!af)) 3059 return SCTP_ERROR_DNS_FAILED; 3060 3061 if (!af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0)) 3062 return SCTP_ERROR_DNS_FAILED; 3063 3064 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3065 * or multicast address. 3066 * (note: wildcard is permitted and requires special handling so 3067 * make sure we check for that) 3068 */ 3069 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3070 return SCTP_ERROR_DNS_FAILED; 3071 3072 switch (asconf_param->param_hdr.type) { 3073 case SCTP_PARAM_ADD_IP: 3074 /* Section 4.2.1: 3075 * If the address 0.0.0.0 or ::0 is provided, the source 3076 * address of the packet MUST be added. 3077 */ 3078 if (af->is_any(&addr)) 3079 memcpy(&addr, &asconf->source, sizeof(addr)); 3080 3081 if (security_sctp_bind_connect(asoc->ep->base.sk, 3082 SCTP_PARAM_ADD_IP, 3083 (struct sockaddr *)&addr, 3084 af->sockaddr_len)) 3085 return SCTP_ERROR_REQ_REFUSED; 3086 3087 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3088 * request and does not have the local resources to add this 3089 * new address to the association, it MUST return an Error 3090 * Cause TLV set to the new error code 'Operation Refused 3091 * Due to Resource Shortage'. 3092 */ 3093 3094 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3095 if (!peer) 3096 return SCTP_ERROR_RSRC_LOW; 3097 3098 /* Start the heartbeat timer. */ 3099 sctp_transport_reset_hb_timer(peer); 3100 asoc->new_transport = peer; 3101 break; 3102 case SCTP_PARAM_DEL_IP: 3103 /* ADDIP 4.3 D7) If a request is received to delete the 3104 * last remaining IP address of a peer endpoint, the receiver 3105 * MUST send an Error Cause TLV with the error cause set to the 3106 * new error code 'Request to Delete Last Remaining IP Address'. 3107 */ 3108 if (asoc->peer.transport_count == 1) 3109 return SCTP_ERROR_DEL_LAST_IP; 3110 3111 /* ADDIP 4.3 D8) If a request is received to delete an IP 3112 * address which is also the source address of the IP packet 3113 * which contained the ASCONF chunk, the receiver MUST reject 3114 * this request. To reject the request the receiver MUST send 3115 * an Error Cause TLV set to the new error code 'Request to 3116 * Delete Source IP Address' 3117 */ 3118 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3119 return SCTP_ERROR_DEL_SRC_IP; 3120 3121 /* Section 4.2.2 3122 * If the address 0.0.0.0 or ::0 is provided, all 3123 * addresses of the peer except the source address of the 3124 * packet MUST be deleted. 3125 */ 3126 if (af->is_any(&addr)) { 3127 sctp_assoc_set_primary(asoc, asconf->transport); 3128 sctp_assoc_del_nonprimary_peers(asoc, 3129 asconf->transport); 3130 return SCTP_ERROR_NO_ERROR; 3131 } 3132 3133 /* If the address is not part of the association, the 3134 * ASCONF-ACK with Error Cause Indication Parameter 3135 * which including cause of Unresolvable Address should 3136 * be sent. 3137 */ 3138 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3139 if (!peer) 3140 return SCTP_ERROR_DNS_FAILED; 3141 3142 sctp_assoc_rm_peer(asoc, peer); 3143 break; 3144 case SCTP_PARAM_SET_PRIMARY: 3145 /* ADDIP Section 4.2.4 3146 * If the address 0.0.0.0 or ::0 is provided, the receiver 3147 * MAY mark the source address of the packet as its 3148 * primary. 3149 */ 3150 if (af->is_any(&addr)) 3151 memcpy(&addr, sctp_source(asconf), sizeof(addr)); 3152 3153 if (security_sctp_bind_connect(asoc->ep->base.sk, 3154 SCTP_PARAM_SET_PRIMARY, 3155 (struct sockaddr *)&addr, 3156 af->sockaddr_len)) 3157 return SCTP_ERROR_REQ_REFUSED; 3158 3159 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3160 if (!peer) 3161 return SCTP_ERROR_DNS_FAILED; 3162 3163 sctp_assoc_set_primary(asoc, peer); 3164 break; 3165 } 3166 3167 return SCTP_ERROR_NO_ERROR; 3168 } 3169 3170 /* Verify the ASCONF packet before we process it. */ 3171 bool sctp_verify_asconf(const struct sctp_association *asoc, 3172 struct sctp_chunk *chunk, bool addr_param_needed, 3173 struct sctp_paramhdr **errp) 3174 { 3175 struct sctp_addip_chunk *addip; 3176 bool addr_param_seen = false; 3177 union sctp_params param; 3178 3179 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr; 3180 sctp_walk_params(param, addip) { 3181 size_t length = ntohs(param.p->length); 3182 3183 *errp = param.p; 3184 switch (param.p->type) { 3185 case SCTP_PARAM_ERR_CAUSE: 3186 break; 3187 case SCTP_PARAM_IPV4_ADDRESS: 3188 if (length != sizeof(struct sctp_ipv4addr_param)) 3189 return false; 3190 /* ensure there is only one addr param and it's in the 3191 * beginning of addip_hdr params, or we reject it. 3192 */ 3193 if (param.v != (addip + 1)) 3194 return false; 3195 addr_param_seen = true; 3196 break; 3197 case SCTP_PARAM_IPV6_ADDRESS: 3198 if (length != sizeof(struct sctp_ipv6addr_param)) 3199 return false; 3200 if (param.v != (addip + 1)) 3201 return false; 3202 addr_param_seen = true; 3203 break; 3204 case SCTP_PARAM_ADD_IP: 3205 case SCTP_PARAM_DEL_IP: 3206 case SCTP_PARAM_SET_PRIMARY: 3207 /* In ASCONF chunks, these need to be first. */ 3208 if (addr_param_needed && !addr_param_seen) 3209 return false; 3210 length = ntohs(param.addip->param_hdr.length); 3211 if (length < sizeof(struct sctp_addip_param) + 3212 sizeof(**errp)) 3213 return false; 3214 break; 3215 case SCTP_PARAM_SUCCESS_REPORT: 3216 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3217 if (length != sizeof(struct sctp_addip_param)) 3218 return false; 3219 break; 3220 default: 3221 /* This is unknown to us, reject! */ 3222 return false; 3223 } 3224 } 3225 3226 /* Remaining sanity checks. */ 3227 if (addr_param_needed && !addr_param_seen) 3228 return false; 3229 if (!addr_param_needed && addr_param_seen) 3230 return false; 3231 if (param.v != chunk->chunk_end) 3232 return false; 3233 3234 return true; 3235 } 3236 3237 /* Process an incoming ASCONF chunk with the next expected serial no. and 3238 * return an ASCONF_ACK chunk to be sent in response. 3239 */ 3240 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3241 struct sctp_chunk *asconf) 3242 { 3243 union sctp_addr_param *addr_param; 3244 struct sctp_addip_chunk *addip; 3245 struct sctp_chunk *asconf_ack; 3246 bool all_param_pass = true; 3247 struct sctp_addiphdr *hdr; 3248 int length = 0, chunk_len; 3249 union sctp_params param; 3250 __be16 err_code; 3251 __u32 serial; 3252 3253 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr; 3254 chunk_len = ntohs(asconf->chunk_hdr->length) - 3255 sizeof(struct sctp_chunkhdr); 3256 hdr = (struct sctp_addiphdr *)asconf->skb->data; 3257 serial = ntohl(hdr->serial); 3258 3259 /* Skip the addiphdr and store a pointer to address parameter. */ 3260 length = sizeof(*hdr); 3261 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3262 chunk_len -= length; 3263 3264 /* Skip the address parameter and store a pointer to the first 3265 * asconf parameter. 3266 */ 3267 length = ntohs(addr_param->p.length); 3268 chunk_len -= length; 3269 3270 /* create an ASCONF_ACK chunk. 3271 * Based on the definitions of parameters, we know that the size of 3272 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3273 * parameters. 3274 */ 3275 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3276 if (!asconf_ack) 3277 goto done; 3278 3279 /* Process the TLVs contained within the ASCONF chunk. */ 3280 sctp_walk_params(param, addip) { 3281 /* Skip preceding address parameters. */ 3282 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 3283 param.p->type == SCTP_PARAM_IPV6_ADDRESS) 3284 continue; 3285 3286 err_code = sctp_process_asconf_param(asoc, asconf, 3287 param.addip); 3288 /* ADDIP 4.1 A7) 3289 * If an error response is received for a TLV parameter, 3290 * all TLVs with no response before the failed TLV are 3291 * considered successful if not reported. All TLVs after 3292 * the failed response are considered unsuccessful unless 3293 * a specific success indication is present for the parameter. 3294 */ 3295 if (err_code != SCTP_ERROR_NO_ERROR) 3296 all_param_pass = false; 3297 if (!all_param_pass) 3298 sctp_add_asconf_response(asconf_ack, param.addip->crr_id, 3299 err_code, param.addip); 3300 3301 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3302 * an IP address sends an 'Out of Resource' in its response, it 3303 * MUST also fail any subsequent add or delete requests bundled 3304 * in the ASCONF. 3305 */ 3306 if (err_code == SCTP_ERROR_RSRC_LOW) 3307 goto done; 3308 } 3309 done: 3310 asoc->peer.addip_serial++; 3311 3312 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3313 * after freeing the reference to old asconf ack if any. 3314 */ 3315 if (asconf_ack) { 3316 sctp_chunk_hold(asconf_ack); 3317 list_add_tail(&asconf_ack->transmitted_list, 3318 &asoc->asconf_ack_list); 3319 } 3320 3321 return asconf_ack; 3322 } 3323 3324 /* Process a asconf parameter that is successfully acked. */ 3325 static void sctp_asconf_param_success(struct sctp_association *asoc, 3326 struct sctp_addip_param *asconf_param) 3327 { 3328 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3329 union sctp_addr_param *addr_param; 3330 struct sctp_sockaddr_entry *saddr; 3331 struct sctp_transport *transport; 3332 union sctp_addr addr; 3333 struct sctp_af *af; 3334 3335 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3336 3337 /* We have checked the packet before, so we do not check again. */ 3338 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3339 if (!af->from_addr_param(&addr, addr_param, htons(bp->port), 0)) 3340 return; 3341 3342 switch (asconf_param->param_hdr.type) { 3343 case SCTP_PARAM_ADD_IP: 3344 /* This is always done in BH context with a socket lock 3345 * held, so the list can not change. 3346 */ 3347 local_bh_disable(); 3348 list_for_each_entry(saddr, &bp->address_list, list) { 3349 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3350 saddr->state = SCTP_ADDR_SRC; 3351 } 3352 local_bh_enable(); 3353 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3354 transports) { 3355 sctp_transport_dst_release(transport); 3356 } 3357 break; 3358 case SCTP_PARAM_DEL_IP: 3359 local_bh_disable(); 3360 sctp_del_bind_addr(bp, &addr); 3361 if (asoc->asconf_addr_del_pending != NULL && 3362 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3363 kfree(asoc->asconf_addr_del_pending); 3364 asoc->asconf_addr_del_pending = NULL; 3365 } 3366 local_bh_enable(); 3367 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3368 transports) { 3369 sctp_transport_dst_release(transport); 3370 } 3371 break; 3372 default: 3373 break; 3374 } 3375 } 3376 3377 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3378 * for the given asconf parameter. If there is no response for this parameter, 3379 * return the error code based on the third argument 'no_err'. 3380 * ADDIP 4.1 3381 * A7) If an error response is received for a TLV parameter, all TLVs with no 3382 * response before the failed TLV are considered successful if not reported. 3383 * All TLVs after the failed response are considered unsuccessful unless a 3384 * specific success indication is present for the parameter. 3385 */ 3386 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3387 struct sctp_addip_param *asconf_param, 3388 int no_err) 3389 { 3390 struct sctp_addip_param *asconf_ack_param; 3391 struct sctp_errhdr *err_param; 3392 int asconf_ack_len; 3393 __be16 err_code; 3394 int length; 3395 3396 if (no_err) 3397 err_code = SCTP_ERROR_NO_ERROR; 3398 else 3399 err_code = SCTP_ERROR_REQ_REFUSED; 3400 3401 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3402 sizeof(struct sctp_chunkhdr); 3403 3404 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3405 * the first asconf_ack parameter. 3406 */ 3407 length = sizeof(struct sctp_addiphdr); 3408 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data + 3409 length); 3410 asconf_ack_len -= length; 3411 3412 while (asconf_ack_len > 0) { 3413 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3414 switch (asconf_ack_param->param_hdr.type) { 3415 case SCTP_PARAM_SUCCESS_REPORT: 3416 return SCTP_ERROR_NO_ERROR; 3417 case SCTP_PARAM_ERR_CAUSE: 3418 length = sizeof(*asconf_ack_param); 3419 err_param = (void *)asconf_ack_param + length; 3420 asconf_ack_len -= length; 3421 if (asconf_ack_len > 0) 3422 return err_param->cause; 3423 else 3424 return SCTP_ERROR_INV_PARAM; 3425 break; 3426 default: 3427 return SCTP_ERROR_INV_PARAM; 3428 } 3429 } 3430 3431 length = ntohs(asconf_ack_param->param_hdr.length); 3432 asconf_ack_param = (void *)asconf_ack_param + length; 3433 asconf_ack_len -= length; 3434 } 3435 3436 return err_code; 3437 } 3438 3439 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3440 int sctp_process_asconf_ack(struct sctp_association *asoc, 3441 struct sctp_chunk *asconf_ack) 3442 { 3443 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3444 struct sctp_addip_param *asconf_param; 3445 __be16 err_code = SCTP_ERROR_NO_ERROR; 3446 union sctp_addr_param *addr_param; 3447 int asconf_len = asconf->skb->len; 3448 int all_param_pass = 0; 3449 int length = 0; 3450 int no_err = 1; 3451 int retval = 0; 3452 3453 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3454 * a pointer to address parameter. 3455 */ 3456 length = sizeof(struct sctp_addip_chunk); 3457 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3458 asconf_len -= length; 3459 3460 /* Skip the address parameter in the last asconf sent and store a 3461 * pointer to the first asconf parameter. 3462 */ 3463 length = ntohs(addr_param->p.length); 3464 asconf_param = (void *)addr_param + length; 3465 asconf_len -= length; 3466 3467 /* ADDIP 4.1 3468 * A8) If there is no response(s) to specific TLV parameter(s), and no 3469 * failures are indicated, then all request(s) are considered 3470 * successful. 3471 */ 3472 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr)) 3473 all_param_pass = 1; 3474 3475 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3476 while (asconf_len > 0) { 3477 if (all_param_pass) 3478 err_code = SCTP_ERROR_NO_ERROR; 3479 else { 3480 err_code = sctp_get_asconf_response(asconf_ack, 3481 asconf_param, 3482 no_err); 3483 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3484 no_err = 0; 3485 } 3486 3487 switch (err_code) { 3488 case SCTP_ERROR_NO_ERROR: 3489 sctp_asconf_param_success(asoc, asconf_param); 3490 break; 3491 3492 case SCTP_ERROR_RSRC_LOW: 3493 retval = 1; 3494 break; 3495 3496 case SCTP_ERROR_UNKNOWN_PARAM: 3497 /* Disable sending this type of asconf parameter in 3498 * future. 3499 */ 3500 asoc->peer.addip_disabled_mask |= 3501 asconf_param->param_hdr.type; 3502 break; 3503 3504 case SCTP_ERROR_REQ_REFUSED: 3505 case SCTP_ERROR_DEL_LAST_IP: 3506 case SCTP_ERROR_DEL_SRC_IP: 3507 default: 3508 break; 3509 } 3510 3511 /* Skip the processed asconf parameter and move to the next 3512 * one. 3513 */ 3514 length = ntohs(asconf_param->param_hdr.length); 3515 asconf_param = (void *)asconf_param + length; 3516 asconf_len -= length; 3517 } 3518 3519 if (no_err && asoc->src_out_of_asoc_ok) { 3520 asoc->src_out_of_asoc_ok = 0; 3521 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3522 } 3523 3524 /* Free the cached last sent asconf chunk. */ 3525 list_del_init(&asconf->transmitted_list); 3526 sctp_chunk_free(asconf); 3527 asoc->addip_last_asconf = NULL; 3528 3529 return retval; 3530 } 3531 3532 /* Make a FWD TSN chunk. */ 3533 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3534 __u32 new_cum_tsn, size_t nstreams, 3535 struct sctp_fwdtsn_skip *skiplist) 3536 { 3537 struct sctp_chunk *retval = NULL; 3538 struct sctp_fwdtsn_hdr ftsn_hdr; 3539 struct sctp_fwdtsn_skip skip; 3540 size_t hint; 3541 int i; 3542 3543 hint = (nstreams + 1) * sizeof(__u32); 3544 3545 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC); 3546 3547 if (!retval) 3548 return NULL; 3549 3550 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3551 retval->subh.fwdtsn_hdr = 3552 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3553 3554 for (i = 0; i < nstreams; i++) { 3555 skip.stream = skiplist[i].stream; 3556 skip.ssn = skiplist[i].ssn; 3557 sctp_addto_chunk(retval, sizeof(skip), &skip); 3558 } 3559 3560 return retval; 3561 } 3562 3563 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc, 3564 __u32 new_cum_tsn, size_t nstreams, 3565 struct sctp_ifwdtsn_skip *skiplist) 3566 { 3567 struct sctp_chunk *retval = NULL; 3568 struct sctp_ifwdtsn_hdr ftsn_hdr; 3569 size_t hint; 3570 3571 hint = (nstreams + 1) * sizeof(__u32); 3572 3573 retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint, 3574 GFP_ATOMIC); 3575 if (!retval) 3576 return NULL; 3577 3578 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3579 retval->subh.ifwdtsn_hdr = 3580 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3581 3582 sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist); 3583 3584 return retval; 3585 } 3586 3587 /* RE-CONFIG 3.1 (RE-CONFIG chunk) 3588 * 0 1 2 3 3589 * 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 3590 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3591 * | Type = 130 | Chunk Flags | Chunk Length | 3592 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3593 * \ \ 3594 * / Re-configuration Parameter / 3595 * \ \ 3596 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3597 * \ \ 3598 * / Re-configuration Parameter (optional) / 3599 * \ \ 3600 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3601 */ 3602 static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc, 3603 int length) 3604 { 3605 struct sctp_reconf_chunk *reconf; 3606 struct sctp_chunk *retval; 3607 3608 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length, 3609 GFP_ATOMIC); 3610 if (!retval) 3611 return NULL; 3612 3613 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr; 3614 retval->param_hdr.v = (u8 *)(reconf + 1); 3615 3616 return retval; 3617 } 3618 3619 /* RE-CONFIG 4.1 (STREAM OUT RESET) 3620 * 0 1 2 3 3621 * 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 3622 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3623 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N | 3624 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3625 * | Re-configuration Request Sequence Number | 3626 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3627 * | Re-configuration Response Sequence Number | 3628 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3629 * | Sender's Last Assigned TSN | 3630 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3631 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3632 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3633 * / ...... / 3634 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3635 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3636 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3637 * 3638 * RE-CONFIG 4.2 (STREAM IN RESET) 3639 * 0 1 2 3 3640 * 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 3641 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3642 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N | 3643 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3644 * | Re-configuration Request Sequence Number | 3645 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3646 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3647 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3648 * / ...... / 3649 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3650 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3651 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3652 */ 3653 struct sctp_chunk *sctp_make_strreset_req( 3654 const struct sctp_association *asoc, 3655 __u16 stream_num, __be16 *stream_list, 3656 bool out, bool in) 3657 { 3658 __u16 stream_len = stream_num * sizeof(__u16); 3659 struct sctp_strreset_outreq outreq; 3660 struct sctp_strreset_inreq inreq; 3661 struct sctp_chunk *retval; 3662 __u16 outlen, inlen; 3663 3664 outlen = (sizeof(outreq) + stream_len) * out; 3665 inlen = (sizeof(inreq) + stream_len) * in; 3666 3667 retval = sctp_make_reconf(asoc, SCTP_PAD4(outlen) + SCTP_PAD4(inlen)); 3668 if (!retval) 3669 return NULL; 3670 3671 if (outlen) { 3672 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST; 3673 outreq.param_hdr.length = htons(outlen); 3674 outreq.request_seq = htonl(asoc->strreset_outseq); 3675 outreq.response_seq = htonl(asoc->strreset_inseq - 1); 3676 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1); 3677 3678 sctp_addto_chunk(retval, sizeof(outreq), &outreq); 3679 3680 if (stream_len) 3681 sctp_addto_chunk(retval, stream_len, stream_list); 3682 } 3683 3684 if (inlen) { 3685 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST; 3686 inreq.param_hdr.length = htons(inlen); 3687 inreq.request_seq = htonl(asoc->strreset_outseq + out); 3688 3689 sctp_addto_chunk(retval, sizeof(inreq), &inreq); 3690 3691 if (stream_len) 3692 sctp_addto_chunk(retval, stream_len, stream_list); 3693 } 3694 3695 return retval; 3696 } 3697 3698 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL) 3699 * 0 1 2 3 3700 * 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 3701 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3702 * | Parameter Type = 15 | Parameter Length = 8 | 3703 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3704 * | Re-configuration Request Sequence Number | 3705 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3706 */ 3707 struct sctp_chunk *sctp_make_strreset_tsnreq( 3708 const struct sctp_association *asoc) 3709 { 3710 struct sctp_strreset_tsnreq tsnreq; 3711 __u16 length = sizeof(tsnreq); 3712 struct sctp_chunk *retval; 3713 3714 retval = sctp_make_reconf(asoc, length); 3715 if (!retval) 3716 return NULL; 3717 3718 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST; 3719 tsnreq.param_hdr.length = htons(length); 3720 tsnreq.request_seq = htonl(asoc->strreset_outseq); 3721 3722 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq); 3723 3724 return retval; 3725 } 3726 3727 /* RE-CONFIG 4.5/4.6 (ADD STREAM) 3728 * 0 1 2 3 3729 * 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 3730 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3731 * | Parameter Type = 17 | Parameter Length = 12 | 3732 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3733 * | Re-configuration Request Sequence Number | 3734 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3735 * | Number of new streams | Reserved | 3736 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3737 */ 3738 struct sctp_chunk *sctp_make_strreset_addstrm( 3739 const struct sctp_association *asoc, 3740 __u16 out, __u16 in) 3741 { 3742 struct sctp_strreset_addstrm addstrm; 3743 __u16 size = sizeof(addstrm); 3744 struct sctp_chunk *retval; 3745 3746 retval = sctp_make_reconf(asoc, (!!out + !!in) * size); 3747 if (!retval) 3748 return NULL; 3749 3750 if (out) { 3751 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS; 3752 addstrm.param_hdr.length = htons(size); 3753 addstrm.number_of_streams = htons(out); 3754 addstrm.request_seq = htonl(asoc->strreset_outseq); 3755 addstrm.reserved = 0; 3756 3757 sctp_addto_chunk(retval, size, &addstrm); 3758 } 3759 3760 if (in) { 3761 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS; 3762 addstrm.param_hdr.length = htons(size); 3763 addstrm.number_of_streams = htons(in); 3764 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out); 3765 addstrm.reserved = 0; 3766 3767 sctp_addto_chunk(retval, size, &addstrm); 3768 } 3769 3770 return retval; 3771 } 3772 3773 /* RE-CONFIG 4.4 (RESP) 3774 * 0 1 2 3 3775 * 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 3776 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3777 * | Parameter Type = 16 | Parameter Length | 3778 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3779 * | Re-configuration Response Sequence Number | 3780 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3781 * | Result | 3782 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3783 */ 3784 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc, 3785 __u32 result, __u32 sn) 3786 { 3787 struct sctp_strreset_resp resp; 3788 __u16 length = sizeof(resp); 3789 struct sctp_chunk *retval; 3790 3791 retval = sctp_make_reconf(asoc, length); 3792 if (!retval) 3793 return NULL; 3794 3795 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3796 resp.param_hdr.length = htons(length); 3797 resp.response_seq = htonl(sn); 3798 resp.result = htonl(result); 3799 3800 sctp_addto_chunk(retval, sizeof(resp), &resp); 3801 3802 return retval; 3803 } 3804 3805 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP) 3806 * 0 1 2 3 3807 * 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 3808 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3809 * | Parameter Type = 16 | Parameter Length | 3810 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3811 * | Re-configuration Response Sequence Number | 3812 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3813 * | Result | 3814 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3815 * | Sender's Next TSN (optional) | 3816 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3817 * | Receiver's Next TSN (optional) | 3818 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3819 */ 3820 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc, 3821 __u32 result, __u32 sn, 3822 __u32 sender_tsn, 3823 __u32 receiver_tsn) 3824 { 3825 struct sctp_strreset_resptsn tsnresp; 3826 __u16 length = sizeof(tsnresp); 3827 struct sctp_chunk *retval; 3828 3829 retval = sctp_make_reconf(asoc, length); 3830 if (!retval) 3831 return NULL; 3832 3833 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3834 tsnresp.param_hdr.length = htons(length); 3835 3836 tsnresp.response_seq = htonl(sn); 3837 tsnresp.result = htonl(result); 3838 tsnresp.senders_next_tsn = htonl(sender_tsn); 3839 tsnresp.receivers_next_tsn = htonl(receiver_tsn); 3840 3841 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp); 3842 3843 return retval; 3844 } 3845 3846 bool sctp_verify_reconf(const struct sctp_association *asoc, 3847 struct sctp_chunk *chunk, 3848 struct sctp_paramhdr **errp) 3849 { 3850 struct sctp_reconf_chunk *hdr; 3851 union sctp_params param; 3852 __be16 last = 0; 3853 __u16 cnt = 0; 3854 3855 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; 3856 sctp_walk_params(param, hdr) { 3857 __u16 length = ntohs(param.p->length); 3858 3859 *errp = param.p; 3860 if (cnt++ > 2) 3861 return false; 3862 switch (param.p->type) { 3863 case SCTP_PARAM_RESET_OUT_REQUEST: 3864 if (length < sizeof(struct sctp_strreset_outreq) || 3865 (last && last != SCTP_PARAM_RESET_RESPONSE && 3866 last != SCTP_PARAM_RESET_IN_REQUEST)) 3867 return false; 3868 break; 3869 case SCTP_PARAM_RESET_IN_REQUEST: 3870 if (length < sizeof(struct sctp_strreset_inreq) || 3871 (last && last != SCTP_PARAM_RESET_OUT_REQUEST)) 3872 return false; 3873 break; 3874 case SCTP_PARAM_RESET_RESPONSE: 3875 if ((length != sizeof(struct sctp_strreset_resp) && 3876 length != sizeof(struct sctp_strreset_resptsn)) || 3877 (last && last != SCTP_PARAM_RESET_RESPONSE && 3878 last != SCTP_PARAM_RESET_OUT_REQUEST)) 3879 return false; 3880 break; 3881 case SCTP_PARAM_RESET_TSN_REQUEST: 3882 if (length != 3883 sizeof(struct sctp_strreset_tsnreq) || last) 3884 return false; 3885 break; 3886 case SCTP_PARAM_RESET_ADD_IN_STREAMS: 3887 if (length != sizeof(struct sctp_strreset_addstrm) || 3888 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS)) 3889 return false; 3890 break; 3891 case SCTP_PARAM_RESET_ADD_OUT_STREAMS: 3892 if (length != sizeof(struct sctp_strreset_addstrm) || 3893 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS)) 3894 return false; 3895 break; 3896 default: 3897 return false; 3898 } 3899 3900 last = param.p->type; 3901 } 3902 3903 return true; 3904 } 3905