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