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