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 static void *sctp_addto_chunk_fixed(struct sctp_chunk *, int len, 85 const void *data); 86 87 /* Control chunk destructor */ 88 static void sctp_control_release_owner(struct sk_buff *skb) 89 { 90 struct sctp_chunk *chunk = skb_shinfo(skb)->destructor_arg; 91 92 if (chunk->shkey) { 93 struct sctp_shared_key *shkey = chunk->shkey; 94 struct sctp_association *asoc = chunk->asoc; 95 96 /* refcnt == 2 and !list_empty mean after this release, it's 97 * not being used anywhere, and it's time to notify userland 98 * that this shkey can be freed if it's been deactivated. 99 */ 100 if (shkey->deactivated && !list_empty(&shkey->key_list) && 101 refcount_read(&shkey->refcnt) == 2) { 102 struct sctp_ulpevent *ev; 103 104 ev = sctp_ulpevent_make_authkey(asoc, shkey->key_id, 105 SCTP_AUTH_FREE_KEY, 106 GFP_KERNEL); 107 if (ev) 108 asoc->stream.si->enqueue_event(&asoc->ulpq, ev); 109 } 110 sctp_auth_shkey_release(chunk->shkey); 111 } 112 } 113 114 static void sctp_control_set_owner_w(struct sctp_chunk *chunk) 115 { 116 struct sctp_association *asoc = chunk->asoc; 117 struct sk_buff *skb = chunk->skb; 118 119 /* TODO: properly account for control chunks. 120 * To do it right we'll need: 121 * 1) endpoint if association isn't known. 122 * 2) proper memory accounting. 123 * 124 * For now don't do anything for now. 125 */ 126 if (chunk->auth) { 127 chunk->shkey = asoc->shkey; 128 sctp_auth_shkey_hold(chunk->shkey); 129 } 130 skb->sk = asoc ? asoc->base.sk : NULL; 131 skb_shinfo(skb)->destructor_arg = chunk; 132 skb->destructor = sctp_control_release_owner; 133 } 134 135 /* What was the inbound interface for this chunk? */ 136 int sctp_chunk_iif(const struct sctp_chunk *chunk) 137 { 138 struct sk_buff *skb = chunk->skb; 139 140 return SCTP_INPUT_CB(skb)->af->skb_iif(skb); 141 } 142 143 /* RFC 2960 3.3.2 Initiation (INIT) (1) 144 * 145 * Note 2: The ECN capable field is reserved for future use of 146 * Explicit Congestion Notification. 147 */ 148 static const struct sctp_paramhdr ecap_param = { 149 SCTP_PARAM_ECN_CAPABLE, 150 cpu_to_be16(sizeof(struct sctp_paramhdr)), 151 }; 152 static const struct sctp_paramhdr prsctp_param = { 153 SCTP_PARAM_FWD_TSN_SUPPORT, 154 cpu_to_be16(sizeof(struct sctp_paramhdr)), 155 }; 156 157 /* A helper to initialize an op error inside a 158 * provided chunk, as most cause codes will be embedded inside an 159 * abort chunk. 160 */ 161 void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, 162 size_t paylen) 163 { 164 struct sctp_errhdr err; 165 __u16 len; 166 167 /* Cause code constants are now defined in network order. */ 168 err.cause = cause_code; 169 len = sizeof(err) + paylen; 170 err.length = htons(len); 171 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(err), &err); 172 } 173 174 /* A helper to initialize an op error inside a 175 * provided chunk, as most cause codes will be embedded inside an 176 * abort chunk. Differs from sctp_init_cause in that it won't oops 177 * if there isn't enough space in the op error chunk 178 */ 179 static int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code, 180 size_t paylen) 181 { 182 struct sctp_errhdr err; 183 __u16 len; 184 185 /* Cause code constants are now defined in network order. */ 186 err.cause = cause_code; 187 len = sizeof(err) + paylen; 188 err.length = htons(len); 189 190 if (skb_tailroom(chunk->skb) < len) 191 return -ENOSPC; 192 193 chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk, sizeof(err), &err); 194 195 return 0; 196 } 197 /* 3.3.2 Initiation (INIT) (1) 198 * 199 * This chunk is used to initiate a SCTP association between two 200 * endpoints. The format of the INIT chunk is shown below: 201 * 202 * 0 1 2 3 203 * 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 1 204 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 205 * | Type = 1 | Chunk Flags | Chunk Length | 206 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 207 * | Initiate Tag | 208 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 209 * | Advertised Receiver Window Credit (a_rwnd) | 210 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 211 * | Number of Outbound Streams | Number of Inbound Streams | 212 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 213 * | Initial TSN | 214 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 215 * \ \ 216 * / Optional/Variable-Length Parameters / 217 * \ \ 218 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 219 * 220 * 221 * The INIT chunk contains the following parameters. Unless otherwise 222 * noted, each parameter MUST only be included once in the INIT chunk. 223 * 224 * Fixed Parameters Status 225 * ---------------------------------------------- 226 * Initiate Tag Mandatory 227 * Advertised Receiver Window Credit Mandatory 228 * Number of Outbound Streams Mandatory 229 * Number of Inbound Streams Mandatory 230 * Initial TSN Mandatory 231 * 232 * Variable Parameters Status Type Value 233 * ------------------------------------------------------------- 234 * IPv4 Address (Note 1) Optional 5 235 * IPv6 Address (Note 1) Optional 6 236 * Cookie Preservative Optional 9 237 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000) 238 * Host Name Address (Note 3) Optional 11 239 * Supported Address Types (Note 4) Optional 12 240 */ 241 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc, 242 const struct sctp_bind_addr *bp, 243 gfp_t gfp, int vparam_len) 244 { 245 struct net *net = sock_net(asoc->base.sk); 246 struct sctp_supported_ext_param ext_param; 247 struct sctp_adaptation_ind_param aiparam; 248 struct sctp_paramhdr *auth_chunks = NULL; 249 struct sctp_paramhdr *auth_hmacs = NULL; 250 struct sctp_supported_addrs_param sat; 251 struct sctp_endpoint *ep = asoc->ep; 252 struct sctp_chunk *retval = NULL; 253 int num_types, addrs_len = 0; 254 struct sctp_inithdr init; 255 union sctp_params addrs; 256 struct sctp_sock *sp; 257 __u8 extensions[5]; 258 size_t chunksize; 259 __be16 types[2]; 260 int num_ext = 0; 261 262 /* RFC 2960 3.3.2 Initiation (INIT) (1) 263 * 264 * Note 1: The INIT chunks can contain multiple addresses that 265 * can be IPv4 and/or IPv6 in any combination. 266 */ 267 268 /* Convert the provided bind address list to raw format. */ 269 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp); 270 271 init.init_tag = htonl(asoc->c.my_vtag); 272 init.a_rwnd = htonl(asoc->rwnd); 273 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 274 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 275 init.initial_tsn = htonl(asoc->c.initial_tsn); 276 277 /* How many address types are needed? */ 278 sp = sctp_sk(asoc->base.sk); 279 num_types = sp->pf->supported_addrs(sp, types); 280 281 chunksize = sizeof(init) + addrs_len; 282 chunksize += SCTP_PAD4(SCTP_SAT_LEN(num_types)); 283 chunksize += sizeof(ecap_param); 284 285 if (asoc->prsctp_enable) 286 chunksize += sizeof(prsctp_param); 287 288 /* ADDIP: Section 4.2.7: 289 * An implementation supporting this extension [ADDIP] MUST list 290 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and 291 * INIT-ACK parameters. 292 */ 293 if (net->sctp.addip_enable) { 294 extensions[num_ext] = SCTP_CID_ASCONF; 295 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 296 num_ext += 2; 297 } 298 299 if (asoc->reconf_enable) { 300 extensions[num_ext] = SCTP_CID_RECONF; 301 num_ext += 1; 302 } 303 304 if (sp->adaptation_ind) 305 chunksize += sizeof(aiparam); 306 307 if (sp->strm_interleave) { 308 extensions[num_ext] = SCTP_CID_I_DATA; 309 num_ext += 1; 310 } 311 312 chunksize += vparam_len; 313 314 /* Account for AUTH related parameters */ 315 if (ep->auth_enable) { 316 /* Add random parameter length*/ 317 chunksize += sizeof(asoc->c.auth_random); 318 319 /* Add HMACS parameter length if any were defined */ 320 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; 321 if (auth_hmacs->length) 322 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 323 else 324 auth_hmacs = NULL; 325 326 /* Add CHUNKS parameter length */ 327 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; 328 if (auth_chunks->length) 329 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 330 else 331 auth_chunks = NULL; 332 333 extensions[num_ext] = SCTP_CID_AUTH; 334 num_ext += 1; 335 } 336 337 /* If we have any extensions to report, account for that */ 338 if (num_ext) 339 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext); 340 341 /* RFC 2960 3.3.2 Initiation (INIT) (1) 342 * 343 * Note 3: An INIT chunk MUST NOT contain more than one Host 344 * Name address parameter. Moreover, the sender of the INIT 345 * MUST NOT combine any other address types with the Host Name 346 * address in the INIT. The receiver of INIT MUST ignore any 347 * other address types if the Host Name address parameter is 348 * present in the received INIT chunk. 349 * 350 * PLEASE DO NOT FIXME [This version does not support Host Name.] 351 */ 352 353 retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp); 354 if (!retval) 355 goto nodata; 356 357 retval->subh.init_hdr = 358 sctp_addto_chunk(retval, sizeof(init), &init); 359 retval->param_hdr.v = 360 sctp_addto_chunk(retval, addrs_len, addrs.v); 361 362 /* RFC 2960 3.3.2 Initiation (INIT) (1) 363 * 364 * Note 4: This parameter, when present, specifies all the 365 * address types the sending endpoint can support. The absence 366 * of this parameter indicates that the sending endpoint can 367 * support any address type. 368 */ 369 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES; 370 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types)); 371 sctp_addto_chunk(retval, sizeof(sat), &sat); 372 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types); 373 374 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 375 376 /* Add the supported extensions parameter. Be nice and add this 377 * fist before addiding the parameters for the extensions themselves 378 */ 379 if (num_ext) { 380 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 381 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext); 382 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); 383 sctp_addto_param(retval, num_ext, extensions); 384 } 385 386 if (asoc->prsctp_enable) 387 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 388 389 if (sp->adaptation_ind) { 390 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 391 aiparam.param_hdr.length = htons(sizeof(aiparam)); 392 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 393 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 394 } 395 396 /* Add SCTP-AUTH chunks to the parameter list */ 397 if (ep->auth_enable) { 398 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random), 399 asoc->c.auth_random); 400 if (auth_hmacs) 401 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 402 auth_hmacs); 403 if (auth_chunks) 404 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 405 auth_chunks); 406 } 407 nodata: 408 kfree(addrs.v); 409 return retval; 410 } 411 412 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, 413 const struct sctp_chunk *chunk, 414 gfp_t gfp, int unkparam_len) 415 { 416 struct sctp_supported_ext_param ext_param; 417 struct sctp_adaptation_ind_param aiparam; 418 struct sctp_paramhdr *auth_chunks = NULL; 419 struct sctp_paramhdr *auth_random = NULL; 420 struct sctp_paramhdr *auth_hmacs = NULL; 421 struct sctp_chunk *retval = NULL; 422 struct sctp_cookie_param *cookie; 423 struct sctp_inithdr initack; 424 union sctp_params addrs; 425 struct sctp_sock *sp; 426 __u8 extensions[5]; 427 size_t chunksize; 428 int num_ext = 0; 429 int cookie_len; 430 int addrs_len; 431 432 /* Note: there may be no addresses to embed. */ 433 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp); 434 435 initack.init_tag = htonl(asoc->c.my_vtag); 436 initack.a_rwnd = htonl(asoc->rwnd); 437 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 438 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 439 initack.initial_tsn = htonl(asoc->c.initial_tsn); 440 441 /* FIXME: We really ought to build the cookie right 442 * into the packet instead of allocating more fresh memory. 443 */ 444 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len, 445 addrs.v, addrs_len); 446 if (!cookie) 447 goto nomem_cookie; 448 449 /* Calculate the total size of allocation, include the reserved 450 * space for reporting unknown parameters if it is specified. 451 */ 452 sp = sctp_sk(asoc->base.sk); 453 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len; 454 455 /* Tell peer that we'll do ECN only if peer advertised such cap. */ 456 if (asoc->peer.ecn_capable) 457 chunksize += sizeof(ecap_param); 458 459 if (asoc->peer.prsctp_capable) 460 chunksize += sizeof(prsctp_param); 461 462 if (asoc->peer.asconf_capable) { 463 extensions[num_ext] = SCTP_CID_ASCONF; 464 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 465 num_ext += 2; 466 } 467 468 if (asoc->peer.reconf_capable) { 469 extensions[num_ext] = SCTP_CID_RECONF; 470 num_ext += 1; 471 } 472 473 if (sp->adaptation_ind) 474 chunksize += sizeof(aiparam); 475 476 if (asoc->intl_enable) { 477 extensions[num_ext] = SCTP_CID_I_DATA; 478 num_ext += 1; 479 } 480 481 if (asoc->peer.auth_capable) { 482 auth_random = (struct sctp_paramhdr *)asoc->c.auth_random; 483 chunksize += ntohs(auth_random->length); 484 485 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; 486 if (auth_hmacs->length) 487 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 488 else 489 auth_hmacs = NULL; 490 491 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; 492 if (auth_chunks->length) 493 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 494 else 495 auth_chunks = NULL; 496 497 extensions[num_ext] = SCTP_CID_AUTH; 498 num_ext += 1; 499 } 500 501 if (num_ext) 502 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext); 503 504 /* Now allocate and fill out the chunk. */ 505 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp); 506 if (!retval) 507 goto nomem_chunk; 508 509 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 510 * 511 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 512 * HEARTBEAT ACK, * etc.) to the same destination transport 513 * address from which it received the DATA or control chunk 514 * to which it is replying. 515 * 516 * [INIT ACK back to where the INIT came from.] 517 */ 518 retval->transport = chunk->transport; 519 520 retval->subh.init_hdr = 521 sctp_addto_chunk(retval, sizeof(initack), &initack); 522 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); 523 sctp_addto_chunk(retval, cookie_len, cookie); 524 if (asoc->peer.ecn_capable) 525 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 526 if (num_ext) { 527 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 528 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext); 529 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); 530 sctp_addto_param(retval, num_ext, extensions); 531 } 532 if (asoc->peer.prsctp_capable) 533 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 534 535 if (sp->adaptation_ind) { 536 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 537 aiparam.param_hdr.length = htons(sizeof(aiparam)); 538 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 539 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 540 } 541 542 if (asoc->peer.auth_capable) { 543 sctp_addto_chunk(retval, ntohs(auth_random->length), 544 auth_random); 545 if (auth_hmacs) 546 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 547 auth_hmacs); 548 if (auth_chunks) 549 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 550 auth_chunks); 551 } 552 553 /* We need to remove the const qualifier at this point. */ 554 retval->asoc = (struct sctp_association *) asoc; 555 556 nomem_chunk: 557 kfree(cookie); 558 nomem_cookie: 559 kfree(addrs.v); 560 return retval; 561 } 562 563 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10): 564 * 565 * This chunk is used only during the initialization of an association. 566 * It is sent by the initiator of an association to its peer to complete 567 * the initialization process. This chunk MUST precede any DATA chunk 568 * sent within the association, but MAY be bundled with one or more DATA 569 * chunks in the same packet. 570 * 571 * 0 1 2 3 572 * 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 1 573 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 574 * | Type = 10 |Chunk Flags | Length | 575 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 576 * / Cookie / 577 * \ \ 578 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 579 * 580 * Chunk Flags: 8 bit 581 * 582 * Set to zero on transmit and ignored on receipt. 583 * 584 * Length: 16 bits (unsigned integer) 585 * 586 * Set to the size of the chunk in bytes, including the 4 bytes of 587 * the chunk header and the size of the Cookie. 588 * 589 * Cookie: variable size 590 * 591 * This field must contain the exact cookie received in the 592 * State Cookie parameter from the previous INIT ACK. 593 * 594 * An implementation SHOULD make the cookie as small as possible 595 * to insure interoperability. 596 */ 597 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, 598 const struct sctp_chunk *chunk) 599 { 600 struct sctp_chunk *retval; 601 int cookie_len; 602 void *cookie; 603 604 cookie = asoc->peer.cookie; 605 cookie_len = asoc->peer.cookie_len; 606 607 /* Build a cookie echo chunk. */ 608 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0, 609 cookie_len, GFP_ATOMIC); 610 if (!retval) 611 goto nodata; 612 retval->subh.cookie_hdr = 613 sctp_addto_chunk(retval, cookie_len, cookie); 614 615 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 616 * 617 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 618 * HEARTBEAT ACK, * etc.) to the same destination transport 619 * address from which it * received the DATA or control chunk 620 * to which it is replying. 621 * 622 * [COOKIE ECHO back to where the INIT ACK came from.] 623 */ 624 if (chunk) 625 retval->transport = chunk->transport; 626 627 nodata: 628 return retval; 629 } 630 631 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11): 632 * 633 * This chunk is used only during the initialization of an 634 * association. It is used to acknowledge the receipt of a COOKIE 635 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent 636 * within the association, but MAY be bundled with one or more DATA 637 * chunks or SACK chunk in the same SCTP packet. 638 * 639 * 0 1 2 3 640 * 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 1 641 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 642 * | Type = 11 |Chunk Flags | Length = 4 | 643 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 644 * 645 * Chunk Flags: 8 bits 646 * 647 * Set to zero on transmit and ignored on receipt. 648 */ 649 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, 650 const struct sctp_chunk *chunk) 651 { 652 struct sctp_chunk *retval; 653 654 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC); 655 656 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 657 * 658 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 659 * HEARTBEAT ACK, * etc.) to the same destination transport 660 * address from which it * received the DATA or control chunk 661 * to which it is replying. 662 * 663 * [COOKIE ACK back to where the COOKIE ECHO came from.] 664 */ 665 if (retval && chunk) 666 retval->transport = chunk->transport; 667 668 return retval; 669 } 670 671 /* 672 * Appendix A: Explicit Congestion Notification: 673 * CWR: 674 * 675 * RFC 2481 details a specific bit for a sender to send in the header of 676 * its next outbound TCP segment to indicate to its peer that it has 677 * reduced its congestion window. This is termed the CWR bit. For 678 * SCTP the same indication is made by including the CWR chunk. 679 * This chunk contains one data element, i.e. the TSN number that 680 * was sent in the ECNE chunk. This element represents the lowest 681 * TSN number in the datagram that was originally marked with the 682 * CE bit. 683 * 684 * 0 1 2 3 685 * 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 1 686 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 687 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 | 688 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 689 * | Lowest TSN Number | 690 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 691 * 692 * Note: The CWR is considered a Control chunk. 693 */ 694 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, 695 const __u32 lowest_tsn, 696 const struct sctp_chunk *chunk) 697 { 698 struct sctp_chunk *retval; 699 struct sctp_cwrhdr cwr; 700 701 cwr.lowest_tsn = htonl(lowest_tsn); 702 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0, 703 sizeof(cwr), GFP_ATOMIC); 704 705 if (!retval) 706 goto nodata; 707 708 retval->subh.ecn_cwr_hdr = 709 sctp_addto_chunk(retval, sizeof(cwr), &cwr); 710 711 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 712 * 713 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 714 * HEARTBEAT ACK, * etc.) to the same destination transport 715 * address from which it * received the DATA or control chunk 716 * to which it is replying. 717 * 718 * [Report a reduced congestion window back to where the ECNE 719 * came from.] 720 */ 721 if (chunk) 722 retval->transport = chunk->transport; 723 724 nodata: 725 return retval; 726 } 727 728 /* Make an ECNE chunk. This is a congestion experienced report. */ 729 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, 730 const __u32 lowest_tsn) 731 { 732 struct sctp_chunk *retval; 733 struct sctp_ecnehdr ecne; 734 735 ecne.lowest_tsn = htonl(lowest_tsn); 736 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0, 737 sizeof(ecne), GFP_ATOMIC); 738 if (!retval) 739 goto nodata; 740 retval->subh.ecne_hdr = 741 sctp_addto_chunk(retval, sizeof(ecne), &ecne); 742 743 nodata: 744 return retval; 745 } 746 747 /* Make a DATA chunk for the given association from the provided 748 * parameters. However, do not populate the data payload. 749 */ 750 struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc, 751 const struct sctp_sndrcvinfo *sinfo, 752 int len, __u8 flags, gfp_t gfp) 753 { 754 struct sctp_chunk *retval; 755 struct sctp_datahdr dp; 756 757 /* We assign the TSN as LATE as possible, not here when 758 * creating the chunk. 759 */ 760 memset(&dp, 0, sizeof(dp)); 761 dp.ppid = sinfo->sinfo_ppid; 762 dp.stream = htons(sinfo->sinfo_stream); 763 764 /* Set the flags for an unordered send. */ 765 if (sinfo->sinfo_flags & SCTP_UNORDERED) 766 flags |= SCTP_DATA_UNORDERED; 767 768 retval = sctp_make_data(asoc, flags, sizeof(dp) + len, gfp); 769 if (!retval) 770 return NULL; 771 772 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp); 773 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo)); 774 775 return retval; 776 } 777 778 /* Create a selective ackowledgement (SACK) for the given 779 * association. This reports on which TSN's we've seen to date, 780 * including duplicates and gaps. 781 */ 782 struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc) 783 { 784 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; 785 struct sctp_association *aptr = (struct sctp_association *)asoc; 786 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; 787 __u16 num_gabs, num_dup_tsns; 788 struct sctp_transport *trans; 789 struct sctp_chunk *retval; 790 struct sctp_sackhdr sack; 791 __u32 ctsn; 792 int len; 793 794 memset(gabs, 0, sizeof(gabs)); 795 ctsn = sctp_tsnmap_get_ctsn(map); 796 797 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn); 798 799 /* How much room is needed in the chunk? */ 800 num_gabs = sctp_tsnmap_num_gabs(map, gabs); 801 num_dup_tsns = sctp_tsnmap_num_dups(map); 802 803 /* Initialize the SACK header. */ 804 sack.cum_tsn_ack = htonl(ctsn); 805 sack.a_rwnd = htonl(asoc->a_rwnd); 806 sack.num_gap_ack_blocks = htons(num_gabs); 807 sack.num_dup_tsns = htons(num_dup_tsns); 808 809 len = sizeof(sack) 810 + sizeof(struct sctp_gap_ack_block) * num_gabs 811 + sizeof(__u32) * num_dup_tsns; 812 813 /* Create the chunk. */ 814 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC); 815 if (!retval) 816 goto nodata; 817 818 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 819 * 820 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 821 * HEARTBEAT ACK, etc.) to the same destination transport 822 * address from which it received the DATA or control chunk to 823 * which it is replying. This rule should also be followed if 824 * the endpoint is bundling DATA chunks together with the 825 * reply chunk. 826 * 827 * However, when acknowledging multiple DATA chunks received 828 * in packets from different source addresses in a single 829 * SACK, the SACK chunk may be transmitted to one of the 830 * destination transport addresses from which the DATA or 831 * control chunks being acknowledged were received. 832 * 833 * [BUG: We do not implement the following paragraph. 834 * Perhaps we should remember the last transport we used for a 835 * SACK and avoid that (if possible) if we have seen any 836 * duplicates. --piggy] 837 * 838 * When a receiver of a duplicate DATA chunk sends a SACK to a 839 * multi- homed endpoint it MAY be beneficial to vary the 840 * destination address and not use the source address of the 841 * DATA chunk. The reason being that receiving a duplicate 842 * from a multi-homed endpoint might indicate that the return 843 * path (as specified in the source address of the DATA chunk) 844 * for the SACK is broken. 845 * 846 * [Send to the address from which we last received a DATA chunk.] 847 */ 848 retval->transport = asoc->peer.last_data_from; 849 850 retval->subh.sack_hdr = 851 sctp_addto_chunk(retval, sizeof(sack), &sack); 852 853 /* Add the gap ack block information. */ 854 if (num_gabs) 855 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, 856 gabs); 857 858 /* Add the duplicate TSN information. */ 859 if (num_dup_tsns) { 860 aptr->stats.idupchunks += num_dup_tsns; 861 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, 862 sctp_tsnmap_get_dups(map)); 863 } 864 /* Once we have a sack generated, check to see what our sack 865 * generation is, if its 0, reset the transports to 0, and reset 866 * the association generation to 1 867 * 868 * The idea is that zero is never used as a valid generation for the 869 * association so no transport will match after a wrap event like this, 870 * Until the next sack 871 */ 872 if (++aptr->peer.sack_generation == 0) { 873 list_for_each_entry(trans, &asoc->peer.transport_addr_list, 874 transports) 875 trans->sack_generation = 0; 876 aptr->peer.sack_generation = 1; 877 } 878 nodata: 879 return retval; 880 } 881 882 /* Make a SHUTDOWN chunk. */ 883 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 884 const struct sctp_chunk *chunk) 885 { 886 struct sctp_shutdownhdr shut; 887 struct sctp_chunk *retval; 888 __u32 ctsn; 889 890 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 891 shut.cum_tsn_ack = htonl(ctsn); 892 893 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0, 894 sizeof(shut), GFP_ATOMIC); 895 if (!retval) 896 goto nodata; 897 898 retval->subh.shutdown_hdr = 899 sctp_addto_chunk(retval, sizeof(shut), &shut); 900 901 if (chunk) 902 retval->transport = chunk->transport; 903 nodata: 904 return retval; 905 } 906 907 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 908 const struct sctp_chunk *chunk) 909 { 910 struct sctp_chunk *retval; 911 912 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0, 913 GFP_ATOMIC); 914 915 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 916 * 917 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 918 * HEARTBEAT ACK, * etc.) to the same destination transport 919 * address from which it * received the DATA or control chunk 920 * to which it is replying. 921 * 922 * [ACK back to where the SHUTDOWN came from.] 923 */ 924 if (retval && chunk) 925 retval->transport = chunk->transport; 926 927 return retval; 928 } 929 930 struct sctp_chunk *sctp_make_shutdown_complete( 931 const struct sctp_association *asoc, 932 const struct sctp_chunk *chunk) 933 { 934 struct sctp_chunk *retval; 935 __u8 flags = 0; 936 937 /* Set the T-bit if we have no association (vtag will be 938 * reflected) 939 */ 940 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; 941 942 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 943 0, GFP_ATOMIC); 944 945 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 946 * 947 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 948 * HEARTBEAT ACK, * etc.) to the same destination transport 949 * address from which it * received the DATA or control chunk 950 * to which it is replying. 951 * 952 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK 953 * came from.] 954 */ 955 if (retval && chunk) 956 retval->transport = chunk->transport; 957 958 return retval; 959 } 960 961 /* Create an ABORT. Note that we set the T bit if we have no 962 * association, except when responding to an INIT (sctpimpguide 2.41). 963 */ 964 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 965 const struct sctp_chunk *chunk, 966 const size_t hint) 967 { 968 struct sctp_chunk *retval; 969 __u8 flags = 0; 970 971 /* Set the T-bit if we have no association and 'chunk' is not 972 * an INIT (vtag will be reflected). 973 */ 974 if (!asoc) { 975 if (chunk && chunk->chunk_hdr && 976 chunk->chunk_hdr->type == SCTP_CID_INIT) 977 flags = 0; 978 else 979 flags = SCTP_CHUNK_FLAG_T; 980 } 981 982 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint, 983 GFP_ATOMIC); 984 985 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 986 * 987 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 988 * HEARTBEAT ACK, * etc.) to the same destination transport 989 * address from which it * received the DATA or control chunk 990 * to which it is replying. 991 * 992 * [ABORT back to where the offender came from.] 993 */ 994 if (retval && chunk) 995 retval->transport = chunk->transport; 996 997 return retval; 998 } 999 1000 /* Helper to create ABORT with a NO_USER_DATA error. */ 1001 struct sctp_chunk *sctp_make_abort_no_data( 1002 const struct sctp_association *asoc, 1003 const struct sctp_chunk *chunk, 1004 __u32 tsn) 1005 { 1006 struct sctp_chunk *retval; 1007 __be32 payload; 1008 1009 retval = sctp_make_abort(asoc, chunk, 1010 sizeof(struct sctp_errhdr) + sizeof(tsn)); 1011 1012 if (!retval) 1013 goto no_mem; 1014 1015 /* Put the tsn back into network byte order. */ 1016 payload = htonl(tsn); 1017 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload)); 1018 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload); 1019 1020 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1021 * 1022 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1023 * HEARTBEAT ACK, * etc.) to the same destination transport 1024 * address from which it * received the DATA or control chunk 1025 * to which it is replying. 1026 * 1027 * [ABORT back to where the offender came from.] 1028 */ 1029 if (chunk) 1030 retval->transport = chunk->transport; 1031 1032 no_mem: 1033 return retval; 1034 } 1035 1036 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ 1037 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 1038 struct msghdr *msg, 1039 size_t paylen) 1040 { 1041 struct sctp_chunk *retval; 1042 void *payload = NULL; 1043 int err; 1044 1045 retval = sctp_make_abort(asoc, NULL, 1046 sizeof(struct sctp_errhdr) + paylen); 1047 if (!retval) 1048 goto err_chunk; 1049 1050 if (paylen) { 1051 /* Put the msg_iov together into payload. */ 1052 payload = kmalloc(paylen, GFP_KERNEL); 1053 if (!payload) 1054 goto err_payload; 1055 1056 err = memcpy_from_msg(payload, msg, paylen); 1057 if (err < 0) 1058 goto err_copy; 1059 } 1060 1061 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); 1062 sctp_addto_chunk(retval, paylen, payload); 1063 1064 if (paylen) 1065 kfree(payload); 1066 1067 return retval; 1068 1069 err_copy: 1070 kfree(payload); 1071 err_payload: 1072 sctp_chunk_free(retval); 1073 retval = NULL; 1074 err_chunk: 1075 return retval; 1076 } 1077 1078 /* Append bytes to the end of a parameter. Will panic if chunk is not big 1079 * enough. 1080 */ 1081 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 1082 const void *data) 1083 { 1084 int chunklen = ntohs(chunk->chunk_hdr->length); 1085 void *target; 1086 1087 target = skb_put(chunk->skb, len); 1088 1089 if (data) 1090 memcpy(target, data, len); 1091 else 1092 memset(target, 0, len); 1093 1094 /* Adjust the chunk length field. */ 1095 chunk->chunk_hdr->length = htons(chunklen + len); 1096 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1097 1098 return target; 1099 } 1100 1101 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ 1102 struct sctp_chunk *sctp_make_abort_violation( 1103 const struct sctp_association *asoc, 1104 const struct sctp_chunk *chunk, 1105 const __u8 *payload, 1106 const size_t paylen) 1107 { 1108 struct sctp_chunk *retval; 1109 struct sctp_paramhdr phdr; 1110 1111 retval = sctp_make_abort(asoc, chunk, sizeof(struct sctp_errhdr) + 1112 paylen + sizeof(phdr)); 1113 if (!retval) 1114 goto end; 1115 1116 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen + 1117 sizeof(phdr)); 1118 1119 phdr.type = htons(chunk->chunk_hdr->type); 1120 phdr.length = chunk->chunk_hdr->length; 1121 sctp_addto_chunk(retval, paylen, payload); 1122 sctp_addto_param(retval, sizeof(phdr), &phdr); 1123 1124 end: 1125 return retval; 1126 } 1127 1128 struct sctp_chunk *sctp_make_violation_paramlen( 1129 const struct sctp_association *asoc, 1130 const struct sctp_chunk *chunk, 1131 struct sctp_paramhdr *param) 1132 { 1133 static const char error[] = "The following parameter had invalid length:"; 1134 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr) + 1135 sizeof(*param); 1136 struct sctp_chunk *retval; 1137 1138 retval = sctp_make_abort(asoc, chunk, payload_len); 1139 if (!retval) 1140 goto nodata; 1141 1142 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, 1143 sizeof(error) + sizeof(*param)); 1144 sctp_addto_chunk(retval, sizeof(error), error); 1145 sctp_addto_param(retval, sizeof(*param), param); 1146 1147 nodata: 1148 return retval; 1149 } 1150 1151 struct sctp_chunk *sctp_make_violation_max_retrans( 1152 const struct sctp_association *asoc, 1153 const struct sctp_chunk *chunk) 1154 { 1155 static const char error[] = "Association exceeded its max_retans count"; 1156 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr); 1157 struct sctp_chunk *retval; 1158 1159 retval = sctp_make_abort(asoc, chunk, payload_len); 1160 if (!retval) 1161 goto nodata; 1162 1163 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error)); 1164 sctp_addto_chunk(retval, sizeof(error), error); 1165 1166 nodata: 1167 return retval; 1168 } 1169 1170 /* Make a HEARTBEAT chunk. */ 1171 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1172 const struct sctp_transport *transport) 1173 { 1174 struct sctp_sender_hb_info hbinfo; 1175 struct sctp_chunk *retval; 1176 1177 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, 1178 sizeof(hbinfo), GFP_ATOMIC); 1179 1180 if (!retval) 1181 goto nodata; 1182 1183 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; 1184 hbinfo.param_hdr.length = htons(sizeof(hbinfo)); 1185 hbinfo.daddr = transport->ipaddr; 1186 hbinfo.sent_at = jiffies; 1187 hbinfo.hb_nonce = transport->hb_nonce; 1188 1189 /* Cast away the 'const', as this is just telling the chunk 1190 * what transport it belongs to. 1191 */ 1192 retval->transport = (struct sctp_transport *) transport; 1193 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo), 1194 &hbinfo); 1195 1196 nodata: 1197 return retval; 1198 } 1199 1200 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1201 const struct sctp_chunk *chunk, 1202 const void *payload, 1203 const size_t paylen) 1204 { 1205 struct sctp_chunk *retval; 1206 1207 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen, 1208 GFP_ATOMIC); 1209 if (!retval) 1210 goto nodata; 1211 1212 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1213 1214 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1215 * 1216 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1217 * HEARTBEAT ACK, * etc.) to the same destination transport 1218 * address from which it * received the DATA or control chunk 1219 * to which it is replying. 1220 * 1221 * [HBACK back to where the HEARTBEAT came from.] 1222 */ 1223 if (chunk) 1224 retval->transport = chunk->transport; 1225 1226 nodata: 1227 return retval; 1228 } 1229 1230 /* Create an Operation Error chunk with the specified space reserved. 1231 * This routine can be used for containing multiple causes in the chunk. 1232 */ 1233 static struct sctp_chunk *sctp_make_op_error_space( 1234 const struct sctp_association *asoc, 1235 const struct sctp_chunk *chunk, 1236 size_t size) 1237 { 1238 struct sctp_chunk *retval; 1239 1240 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0, 1241 sizeof(struct sctp_errhdr) + size, 1242 GFP_ATOMIC); 1243 if (!retval) 1244 goto nodata; 1245 1246 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1247 * 1248 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1249 * HEARTBEAT ACK, etc.) to the same destination transport 1250 * address from which it received the DATA or control chunk 1251 * to which it is replying. 1252 * 1253 */ 1254 if (chunk) 1255 retval->transport = chunk->transport; 1256 1257 nodata: 1258 return retval; 1259 } 1260 1261 /* Create an Operation Error chunk of a fixed size, 1262 * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) 1263 * This is a helper function to allocate an error chunk for 1264 * for those invalid parameter codes in which we may not want 1265 * to report all the errors, if the incoming chunk is large 1266 */ 1267 static inline struct sctp_chunk *sctp_make_op_error_fixed( 1268 const struct sctp_association *asoc, 1269 const struct sctp_chunk *chunk) 1270 { 1271 size_t size = asoc ? asoc->pathmtu : 0; 1272 1273 if (!size) 1274 size = SCTP_DEFAULT_MAXSEGMENT; 1275 1276 return sctp_make_op_error_space(asoc, chunk, size); 1277 } 1278 1279 /* Create an Operation Error chunk. */ 1280 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1281 const struct sctp_chunk *chunk, 1282 __be16 cause_code, const void *payload, 1283 size_t paylen, size_t reserve_tail) 1284 { 1285 struct sctp_chunk *retval; 1286 1287 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); 1288 if (!retval) 1289 goto nodata; 1290 1291 sctp_init_cause(retval, cause_code, paylen + reserve_tail); 1292 sctp_addto_chunk(retval, paylen, payload); 1293 if (reserve_tail) 1294 sctp_addto_param(retval, reserve_tail, NULL); 1295 1296 nodata: 1297 return retval; 1298 } 1299 1300 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc, 1301 __u16 key_id) 1302 { 1303 struct sctp_authhdr auth_hdr; 1304 struct sctp_hmac *hmac_desc; 1305 struct sctp_chunk *retval; 1306 1307 /* Get the first hmac that the peer told us to use */ 1308 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1309 if (unlikely(!hmac_desc)) 1310 return NULL; 1311 1312 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0, 1313 hmac_desc->hmac_len + sizeof(auth_hdr), 1314 GFP_ATOMIC); 1315 if (!retval) 1316 return NULL; 1317 1318 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1319 auth_hdr.shkey_id = htons(key_id); 1320 1321 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr), 1322 &auth_hdr); 1323 1324 skb_put_zero(retval->skb, hmac_desc->hmac_len); 1325 1326 /* Adjust the chunk header to include the empty MAC */ 1327 retval->chunk_hdr->length = 1328 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1329 retval->chunk_end = skb_tail_pointer(retval->skb); 1330 1331 return retval; 1332 } 1333 1334 1335 /******************************************************************** 1336 * 2nd Level Abstractions 1337 ********************************************************************/ 1338 1339 /* Turn an skb into a chunk. 1340 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1341 * 1342 * sctpimpguide-05.txt Section 2.8.2 1343 * M1) Each time a new DATA chunk is transmitted 1344 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1345 * 'TSN.Missing.Report' count will be used to determine missing chunks 1346 * and when to fast retransmit. 1347 * 1348 */ 1349 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1350 const struct sctp_association *asoc, 1351 struct sock *sk, gfp_t gfp) 1352 { 1353 struct sctp_chunk *retval; 1354 1355 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp); 1356 1357 if (!retval) 1358 goto nodata; 1359 if (!sk) 1360 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb); 1361 1362 INIT_LIST_HEAD(&retval->list); 1363 retval->skb = skb; 1364 retval->asoc = (struct sctp_association *)asoc; 1365 retval->singleton = 1; 1366 1367 retval->fast_retransmit = SCTP_CAN_FRTX; 1368 1369 /* Polish the bead hole. */ 1370 INIT_LIST_HEAD(&retval->transmitted_list); 1371 INIT_LIST_HEAD(&retval->frag_list); 1372 SCTP_DBG_OBJCNT_INC(chunk); 1373 refcount_set(&retval->refcnt, 1); 1374 1375 nodata: 1376 return retval; 1377 } 1378 1379 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1380 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1381 union sctp_addr *dest) 1382 { 1383 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1384 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1385 } 1386 1387 /* Extract the source address from a chunk. */ 1388 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1389 { 1390 /* If we have a known transport, use that. */ 1391 if (chunk->transport) { 1392 return &chunk->transport->ipaddr; 1393 } else { 1394 /* Otherwise, extract it from the IP header. */ 1395 return &chunk->source; 1396 } 1397 } 1398 1399 /* Create a new chunk, setting the type and flags headers from the 1400 * arguments, reserving enough space for a 'paylen' byte payload. 1401 */ 1402 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 1403 __u8 type, __u8 flags, int paylen, 1404 gfp_t gfp) 1405 { 1406 struct sctp_chunkhdr *chunk_hdr; 1407 struct sctp_chunk *retval; 1408 struct sk_buff *skb; 1409 struct sock *sk; 1410 int chunklen; 1411 1412 chunklen = SCTP_PAD4(sizeof(*chunk_hdr) + paylen); 1413 if (chunklen > SCTP_MAX_CHUNK_LEN) 1414 goto nodata; 1415 1416 /* No need to allocate LL here, as this is only a chunk. */ 1417 skb = alloc_skb(chunklen, gfp); 1418 if (!skb) 1419 goto nodata; 1420 1421 /* Make room for the chunk header. */ 1422 chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr)); 1423 chunk_hdr->type = type; 1424 chunk_hdr->flags = flags; 1425 chunk_hdr->length = htons(sizeof(*chunk_hdr)); 1426 1427 sk = asoc ? asoc->base.sk : NULL; 1428 retval = sctp_chunkify(skb, asoc, sk, gfp); 1429 if (!retval) { 1430 kfree_skb(skb); 1431 goto nodata; 1432 } 1433 1434 retval->chunk_hdr = chunk_hdr; 1435 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr); 1436 1437 /* Determine if the chunk needs to be authenticated */ 1438 if (sctp_auth_send_cid(type, asoc)) 1439 retval->auth = 1; 1440 1441 return retval; 1442 nodata: 1443 return NULL; 1444 } 1445 1446 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 1447 __u8 flags, int paylen, gfp_t gfp) 1448 { 1449 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp); 1450 } 1451 1452 struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc, 1453 __u8 flags, int paylen, gfp_t gfp) 1454 { 1455 return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp); 1456 } 1457 1458 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 1459 __u8 type, __u8 flags, int paylen, 1460 gfp_t gfp) 1461 { 1462 struct sctp_chunk *chunk; 1463 1464 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp); 1465 if (chunk) 1466 sctp_control_set_owner_w(chunk); 1467 1468 return chunk; 1469 } 1470 1471 /* Release the memory occupied by a chunk. */ 1472 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1473 { 1474 BUG_ON(!list_empty(&chunk->list)); 1475 list_del_init(&chunk->transmitted_list); 1476 1477 consume_skb(chunk->skb); 1478 consume_skb(chunk->auth_chunk); 1479 1480 SCTP_DBG_OBJCNT_DEC(chunk); 1481 kmem_cache_free(sctp_chunk_cachep, chunk); 1482 } 1483 1484 /* Possibly, free the chunk. */ 1485 void sctp_chunk_free(struct sctp_chunk *chunk) 1486 { 1487 /* Release our reference on the message tracker. */ 1488 if (chunk->msg) 1489 sctp_datamsg_put(chunk->msg); 1490 1491 sctp_chunk_put(chunk); 1492 } 1493 1494 /* Grab a reference to the chunk. */ 1495 void sctp_chunk_hold(struct sctp_chunk *ch) 1496 { 1497 refcount_inc(&ch->refcnt); 1498 } 1499 1500 /* Release a reference to the chunk. */ 1501 void sctp_chunk_put(struct sctp_chunk *ch) 1502 { 1503 if (refcount_dec_and_test(&ch->refcnt)) 1504 sctp_chunk_destroy(ch); 1505 } 1506 1507 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1508 * enough. 1509 */ 1510 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1511 { 1512 int chunklen = ntohs(chunk->chunk_hdr->length); 1513 int padlen = SCTP_PAD4(chunklen) - chunklen; 1514 void *target; 1515 1516 skb_put_zero(chunk->skb, padlen); 1517 target = skb_put_data(chunk->skb, data, len); 1518 1519 /* Adjust the chunk length field. */ 1520 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1521 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1522 1523 return target; 1524 } 1525 1526 /* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient 1527 * space in the chunk 1528 */ 1529 static void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk, 1530 int len, const void *data) 1531 { 1532 if (skb_tailroom(chunk->skb) >= len) 1533 return sctp_addto_chunk(chunk, len, data); 1534 else 1535 return NULL; 1536 } 1537 1538 /* Append bytes from user space to the end of a chunk. Will panic if 1539 * chunk is not big enough. 1540 * Returns a kernel err value. 1541 */ 1542 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len, 1543 struct iov_iter *from) 1544 { 1545 void *target; 1546 1547 /* Make room in chunk for data. */ 1548 target = skb_put(chunk->skb, len); 1549 1550 /* Copy data (whole iovec) into chunk */ 1551 if (!copy_from_iter_full(target, len, from)) 1552 return -EFAULT; 1553 1554 /* Adjust the chunk length field. */ 1555 chunk->chunk_hdr->length = 1556 htons(ntohs(chunk->chunk_hdr->length) + len); 1557 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1558 1559 return 0; 1560 } 1561 1562 /* Helper function to assign a TSN if needed. This assumes that both 1563 * the data_hdr and association have already been assigned. 1564 */ 1565 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1566 { 1567 struct sctp_stream *stream; 1568 struct sctp_chunk *lchunk; 1569 struct sctp_datamsg *msg; 1570 __u16 ssn, sid; 1571 1572 if (chunk->has_ssn) 1573 return; 1574 1575 /* All fragments will be on the same stream */ 1576 sid = ntohs(chunk->subh.data_hdr->stream); 1577 stream = &chunk->asoc->stream; 1578 1579 /* Now assign the sequence number to the entire message. 1580 * All fragments must have the same stream sequence number. 1581 */ 1582 msg = chunk->msg; 1583 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1584 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1585 ssn = 0; 1586 } else { 1587 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1588 ssn = sctp_ssn_next(stream, out, sid); 1589 else 1590 ssn = sctp_ssn_peek(stream, out, sid); 1591 } 1592 1593 lchunk->subh.data_hdr->ssn = htons(ssn); 1594 lchunk->has_ssn = 1; 1595 } 1596 } 1597 1598 /* Helper function to assign a TSN if needed. This assumes that both 1599 * the data_hdr and association have already been assigned. 1600 */ 1601 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1602 { 1603 if (!chunk->has_tsn) { 1604 /* This is the last possible instant to 1605 * assign a TSN. 1606 */ 1607 chunk->subh.data_hdr->tsn = 1608 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1609 chunk->has_tsn = 1; 1610 } 1611 } 1612 1613 /* Create a CLOSED association to use with an incoming packet. */ 1614 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1615 struct sctp_chunk *chunk, 1616 gfp_t gfp) 1617 { 1618 struct sctp_association *asoc; 1619 enum sctp_scope scope; 1620 struct sk_buff *skb; 1621 1622 /* Create the bare association. */ 1623 scope = sctp_scope(sctp_source(chunk)); 1624 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1625 if (!asoc) 1626 goto nodata; 1627 asoc->temp = 1; 1628 skb = chunk->skb; 1629 /* Create an entry for the source address of the packet. */ 1630 SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1); 1631 1632 nodata: 1633 return asoc; 1634 } 1635 1636 /* Build a cookie representing asoc. 1637 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1638 */ 1639 static struct sctp_cookie_param *sctp_pack_cookie( 1640 const struct sctp_endpoint *ep, 1641 const struct sctp_association *asoc, 1642 const struct sctp_chunk *init_chunk, 1643 int *cookie_len, const __u8 *raw_addrs, 1644 int addrs_len) 1645 { 1646 struct sctp_signed_cookie *cookie; 1647 struct sctp_cookie_param *retval; 1648 int headersize, bodysize; 1649 1650 /* Header size is static data prior to the actual cookie, including 1651 * any padding. 1652 */ 1653 headersize = sizeof(struct sctp_paramhdr) + 1654 (sizeof(struct sctp_signed_cookie) - 1655 sizeof(struct sctp_cookie)); 1656 bodysize = sizeof(struct sctp_cookie) 1657 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1658 1659 /* Pad out the cookie to a multiple to make the signature 1660 * functions simpler to write. 1661 */ 1662 if (bodysize % SCTP_COOKIE_MULTIPLE) 1663 bodysize += SCTP_COOKIE_MULTIPLE 1664 - (bodysize % SCTP_COOKIE_MULTIPLE); 1665 *cookie_len = headersize + bodysize; 1666 1667 /* Clear this memory since we are sending this data structure 1668 * out on the network. 1669 */ 1670 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1671 if (!retval) 1672 goto nodata; 1673 1674 cookie = (struct sctp_signed_cookie *) retval->body; 1675 1676 /* Set up the parameter header. */ 1677 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1678 retval->p.length = htons(*cookie_len); 1679 1680 /* Copy the cookie part of the association itself. */ 1681 cookie->c = asoc->c; 1682 /* Save the raw address list length in the cookie. */ 1683 cookie->c.raw_addr_list_len = addrs_len; 1684 1685 /* Remember PR-SCTP capability. */ 1686 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1687 1688 /* Save adaptation indication in the cookie. */ 1689 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1690 1691 /* Set an expiration time for the cookie. */ 1692 cookie->c.expiration = ktime_add(asoc->cookie_life, 1693 ktime_get_real()); 1694 1695 /* Copy the peer's init packet. */ 1696 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr, 1697 ntohs(init_chunk->chunk_hdr->length)); 1698 1699 /* Copy the raw local address list of the association. */ 1700 memcpy((__u8 *)&cookie->c.peer_init[0] + 1701 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1702 1703 if (sctp_sk(ep->base.sk)->hmac) { 1704 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac); 1705 int err; 1706 1707 /* Sign the message. */ 1708 desc->tfm = sctp_sk(ep->base.sk)->hmac; 1709 desc->flags = 0; 1710 1711 err = crypto_shash_setkey(desc->tfm, ep->secret_key, 1712 sizeof(ep->secret_key)) ?: 1713 crypto_shash_digest(desc, (u8 *)&cookie->c, bodysize, 1714 cookie->signature); 1715 shash_desc_zero(desc); 1716 if (err) 1717 goto free_cookie; 1718 } 1719 1720 return retval; 1721 1722 free_cookie: 1723 kfree(retval); 1724 nodata: 1725 *cookie_len = 0; 1726 return NULL; 1727 } 1728 1729 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1730 struct sctp_association *sctp_unpack_cookie( 1731 const struct sctp_endpoint *ep, 1732 const struct sctp_association *asoc, 1733 struct sctp_chunk *chunk, gfp_t gfp, 1734 int *error, struct sctp_chunk **errp) 1735 { 1736 struct sctp_association *retval = NULL; 1737 int headersize, bodysize, fixed_size; 1738 struct sctp_signed_cookie *cookie; 1739 struct sk_buff *skb = chunk->skb; 1740 struct sctp_cookie *bear_cookie; 1741 __u8 *digest = ep->digest; 1742 enum sctp_scope scope; 1743 unsigned int len; 1744 ktime_t kt; 1745 1746 /* Header size is static data prior to the actual cookie, including 1747 * any padding. 1748 */ 1749 headersize = sizeof(struct sctp_chunkhdr) + 1750 (sizeof(struct sctp_signed_cookie) - 1751 sizeof(struct sctp_cookie)); 1752 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1753 fixed_size = headersize + sizeof(struct sctp_cookie); 1754 1755 /* Verify that the chunk looks like it even has a cookie. 1756 * There must be enough room for our cookie and our peer's 1757 * INIT chunk. 1758 */ 1759 len = ntohs(chunk->chunk_hdr->length); 1760 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1761 goto malformed; 1762 1763 /* Verify that the cookie has been padded out. */ 1764 if (bodysize % SCTP_COOKIE_MULTIPLE) 1765 goto malformed; 1766 1767 /* Process the cookie. */ 1768 cookie = chunk->subh.cookie_hdr; 1769 bear_cookie = &cookie->c; 1770 1771 if (!sctp_sk(ep->base.sk)->hmac) 1772 goto no_hmac; 1773 1774 /* Check the signature. */ 1775 { 1776 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac); 1777 int err; 1778 1779 desc->tfm = sctp_sk(ep->base.sk)->hmac; 1780 desc->flags = 0; 1781 1782 err = crypto_shash_setkey(desc->tfm, ep->secret_key, 1783 sizeof(ep->secret_key)) ?: 1784 crypto_shash_digest(desc, (u8 *)bear_cookie, bodysize, 1785 digest); 1786 shash_desc_zero(desc); 1787 1788 if (err) { 1789 *error = -SCTP_IERROR_NOMEM; 1790 goto fail; 1791 } 1792 } 1793 1794 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1795 *error = -SCTP_IERROR_BAD_SIG; 1796 goto fail; 1797 } 1798 1799 no_hmac: 1800 /* IG Section 2.35.2: 1801 * 3) Compare the port numbers and the verification tag contained 1802 * within the COOKIE ECHO chunk to the actual port numbers and the 1803 * verification tag within the SCTP common header of the received 1804 * packet. If these values do not match the packet MUST be silently 1805 * discarded, 1806 */ 1807 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1808 *error = -SCTP_IERROR_BAD_TAG; 1809 goto fail; 1810 } 1811 1812 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1813 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1814 *error = -SCTP_IERROR_BAD_PORTS; 1815 goto fail; 1816 } 1817 1818 /* Check to see if the cookie is stale. If there is already 1819 * an association, there is no need to check cookie's expiration 1820 * for init collision case of lost COOKIE ACK. 1821 * If skb has been timestamped, then use the stamp, otherwise 1822 * use current time. This introduces a small possibility that 1823 * that a cookie may be considered expired, but his would only slow 1824 * down the new association establishment instead of every packet. 1825 */ 1826 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1827 kt = skb_get_ktime(skb); 1828 else 1829 kt = ktime_get_real(); 1830 1831 if (!asoc && ktime_before(bear_cookie->expiration, kt)) { 1832 /* 1833 * Section 3.3.10.3 Stale Cookie Error (3) 1834 * 1835 * Cause of error 1836 * --------------- 1837 * Stale Cookie Error: Indicates the receipt of a valid State 1838 * Cookie that has expired. 1839 */ 1840 len = ntohs(chunk->chunk_hdr->length); 1841 *errp = sctp_make_op_error_space(asoc, chunk, len); 1842 if (*errp) { 1843 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); 1844 __be32 n = htonl(usecs); 1845 1846 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE, 1847 sizeof(n)); 1848 sctp_addto_chunk(*errp, sizeof(n), &n); 1849 *error = -SCTP_IERROR_STALE_COOKIE; 1850 } else 1851 *error = -SCTP_IERROR_NOMEM; 1852 1853 goto fail; 1854 } 1855 1856 /* Make a new base association. */ 1857 scope = sctp_scope(sctp_source(chunk)); 1858 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1859 if (!retval) { 1860 *error = -SCTP_IERROR_NOMEM; 1861 goto fail; 1862 } 1863 1864 /* Set up our peer's port number. */ 1865 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1866 1867 /* Populate the association from the cookie. */ 1868 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1869 1870 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1871 GFP_ATOMIC) < 0) { 1872 *error = -SCTP_IERROR_NOMEM; 1873 goto fail; 1874 } 1875 1876 /* Also, add the destination address. */ 1877 if (list_empty(&retval->base.bind_addr.address_list)) { 1878 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1879 sizeof(chunk->dest), SCTP_ADDR_SRC, 1880 GFP_ATOMIC); 1881 } 1882 1883 retval->next_tsn = retval->c.initial_tsn; 1884 retval->ctsn_ack_point = retval->next_tsn - 1; 1885 retval->addip_serial = retval->c.initial_tsn; 1886 retval->strreset_outseq = retval->c.initial_tsn; 1887 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1888 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1889 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1890 1891 /* The INIT stuff will be done by the side effects. */ 1892 return retval; 1893 1894 fail: 1895 if (retval) 1896 sctp_association_free(retval); 1897 1898 return NULL; 1899 1900 malformed: 1901 /* Yikes! The packet is either corrupt or deliberately 1902 * malformed. 1903 */ 1904 *error = -SCTP_IERROR_MALFORMED; 1905 goto fail; 1906 } 1907 1908 /******************************************************************** 1909 * 3rd Level Abstractions 1910 ********************************************************************/ 1911 1912 struct __sctp_missing { 1913 __be32 num_missing; 1914 __be16 type; 1915 } __packed; 1916 1917 /* 1918 * Report a missing mandatory parameter. 1919 */ 1920 static int sctp_process_missing_param(const struct sctp_association *asoc, 1921 enum sctp_param paramtype, 1922 struct sctp_chunk *chunk, 1923 struct sctp_chunk **errp) 1924 { 1925 struct __sctp_missing report; 1926 __u16 len; 1927 1928 len = SCTP_PAD4(sizeof(report)); 1929 1930 /* Make an ERROR chunk, preparing enough room for 1931 * returning multiple unknown parameters. 1932 */ 1933 if (!*errp) 1934 *errp = sctp_make_op_error_space(asoc, chunk, len); 1935 1936 if (*errp) { 1937 report.num_missing = htonl(1); 1938 report.type = paramtype; 1939 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1940 sizeof(report)); 1941 sctp_addto_chunk(*errp, sizeof(report), &report); 1942 } 1943 1944 /* Stop processing this chunk. */ 1945 return 0; 1946 } 1947 1948 /* Report an Invalid Mandatory Parameter. */ 1949 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1950 struct sctp_chunk *chunk, 1951 struct sctp_chunk **errp) 1952 { 1953 /* Invalid Mandatory Parameter Error has no payload. */ 1954 1955 if (!*errp) 1956 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1957 1958 if (*errp) 1959 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1960 1961 /* Stop processing this chunk. */ 1962 return 0; 1963 } 1964 1965 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1966 struct sctp_paramhdr *param, 1967 const struct sctp_chunk *chunk, 1968 struct sctp_chunk **errp) 1969 { 1970 /* This is a fatal error. Any accumulated non-fatal errors are 1971 * not reported. 1972 */ 1973 if (*errp) 1974 sctp_chunk_free(*errp); 1975 1976 /* Create an error chunk and fill it in with our payload. */ 1977 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1978 1979 return 0; 1980 } 1981 1982 1983 /* Do not attempt to handle the HOST_NAME parm. However, do 1984 * send back an indicator to the peer. 1985 */ 1986 static int sctp_process_hn_param(const struct sctp_association *asoc, 1987 union sctp_params param, 1988 struct sctp_chunk *chunk, 1989 struct sctp_chunk **errp) 1990 { 1991 __u16 len = ntohs(param.p->length); 1992 1993 /* Processing of the HOST_NAME parameter will generate an 1994 * ABORT. If we've accumulated any non-fatal errors, they 1995 * would be unrecognized parameters and we should not include 1996 * them in the ABORT. 1997 */ 1998 if (*errp) 1999 sctp_chunk_free(*errp); 2000 2001 *errp = sctp_make_op_error_space(asoc, chunk, len); 2002 2003 if (*errp) { 2004 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len); 2005 sctp_addto_chunk(*errp, len, param.v); 2006 } 2007 2008 /* Stop processing this chunk. */ 2009 return 0; 2010 } 2011 2012 static int sctp_verify_ext_param(struct net *net, union sctp_params param) 2013 { 2014 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2015 int have_asconf = 0; 2016 int have_auth = 0; 2017 int i; 2018 2019 for (i = 0; i < num_ext; i++) { 2020 switch (param.ext->chunks[i]) { 2021 case SCTP_CID_AUTH: 2022 have_auth = 1; 2023 break; 2024 case SCTP_CID_ASCONF: 2025 case SCTP_CID_ASCONF_ACK: 2026 have_asconf = 1; 2027 break; 2028 } 2029 } 2030 2031 /* ADD-IP Security: The draft requires us to ABORT or ignore the 2032 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 2033 * only if ADD-IP is turned on and we are not backward-compatible 2034 * mode. 2035 */ 2036 if (net->sctp.addip_noauth) 2037 return 1; 2038 2039 if (net->sctp.addip_enable && !have_auth && have_asconf) 2040 return 0; 2041 2042 return 1; 2043 } 2044 2045 static void sctp_process_ext_param(struct sctp_association *asoc, 2046 union sctp_params param) 2047 { 2048 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2049 struct net *net = sock_net(asoc->base.sk); 2050 int i; 2051 2052 for (i = 0; i < num_ext; i++) { 2053 switch (param.ext->chunks[i]) { 2054 case SCTP_CID_RECONF: 2055 if (asoc->reconf_enable && 2056 !asoc->peer.reconf_capable) 2057 asoc->peer.reconf_capable = 1; 2058 break; 2059 case SCTP_CID_FWD_TSN: 2060 if (asoc->prsctp_enable && !asoc->peer.prsctp_capable) 2061 asoc->peer.prsctp_capable = 1; 2062 break; 2063 case SCTP_CID_AUTH: 2064 /* if the peer reports AUTH, assume that he 2065 * supports AUTH. 2066 */ 2067 if (asoc->ep->auth_enable) 2068 asoc->peer.auth_capable = 1; 2069 break; 2070 case SCTP_CID_ASCONF: 2071 case SCTP_CID_ASCONF_ACK: 2072 if (net->sctp.addip_enable) 2073 asoc->peer.asconf_capable = 1; 2074 break; 2075 case SCTP_CID_I_DATA: 2076 if (sctp_sk(asoc->base.sk)->strm_interleave) 2077 asoc->intl_enable = 1; 2078 break; 2079 default: 2080 break; 2081 } 2082 } 2083 } 2084 2085 /* RFC 3.2.1 & the Implementers Guide 2.2. 2086 * 2087 * The Parameter Types are encoded such that the 2088 * highest-order two bits specify the action that must be 2089 * taken if the processing endpoint does not recognize the 2090 * Parameter Type. 2091 * 2092 * 00 - Stop processing this parameter; do not process any further 2093 * parameters within this chunk 2094 * 2095 * 01 - Stop processing this parameter, do not process any further 2096 * parameters within this chunk, and report the unrecognized 2097 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2098 * 2099 * 10 - Skip this parameter and continue processing. 2100 * 2101 * 11 - Skip this parameter and continue processing but 2102 * report the unrecognized parameter in an 2103 * 'Unrecognized Parameter' ERROR chunk. 2104 * 2105 * Return value: 2106 * SCTP_IERROR_NO_ERROR - continue with the chunk 2107 * SCTP_IERROR_ERROR - stop and report an error. 2108 * SCTP_IERROR_NOMEME - out of memory. 2109 */ 2110 static enum sctp_ierror sctp_process_unk_param( 2111 const struct sctp_association *asoc, 2112 union sctp_params param, 2113 struct sctp_chunk *chunk, 2114 struct sctp_chunk **errp) 2115 { 2116 int retval = SCTP_IERROR_NO_ERROR; 2117 2118 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2119 case SCTP_PARAM_ACTION_DISCARD: 2120 retval = SCTP_IERROR_ERROR; 2121 break; 2122 case SCTP_PARAM_ACTION_SKIP: 2123 break; 2124 case SCTP_PARAM_ACTION_DISCARD_ERR: 2125 retval = SCTP_IERROR_ERROR; 2126 /* Fall through */ 2127 case SCTP_PARAM_ACTION_SKIP_ERR: 2128 /* Make an ERROR chunk, preparing enough room for 2129 * returning multiple unknown parameters. 2130 */ 2131 if (NULL == *errp) 2132 *errp = sctp_make_op_error_fixed(asoc, chunk); 2133 2134 if (*errp) { 2135 if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2136 SCTP_PAD4(ntohs(param.p->length)))) 2137 sctp_addto_chunk_fixed(*errp, 2138 SCTP_PAD4(ntohs(param.p->length)), 2139 param.v); 2140 } else { 2141 /* If there is no memory for generating the ERROR 2142 * report as specified, an ABORT will be triggered 2143 * to the peer and the association won't be 2144 * established. 2145 */ 2146 retval = SCTP_IERROR_NOMEM; 2147 } 2148 break; 2149 default: 2150 break; 2151 } 2152 2153 return retval; 2154 } 2155 2156 /* Verify variable length parameters 2157 * Return values: 2158 * SCTP_IERROR_ABORT - trigger an ABORT 2159 * SCTP_IERROR_NOMEM - out of memory (abort) 2160 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2161 * SCTP_IERROR_NO_ERROR - continue with the chunk 2162 */ 2163 static enum sctp_ierror sctp_verify_param(struct net *net, 2164 const struct sctp_endpoint *ep, 2165 const struct sctp_association *asoc, 2166 union sctp_params param, 2167 enum sctp_cid cid, 2168 struct sctp_chunk *chunk, 2169 struct sctp_chunk **err_chunk) 2170 { 2171 struct sctp_hmac_algo_param *hmacs; 2172 int retval = SCTP_IERROR_NO_ERROR; 2173 __u16 n_elt, id = 0; 2174 int i; 2175 2176 /* FIXME - This routine is not looking at each parameter per the 2177 * chunk type, i.e., unrecognized parameters should be further 2178 * identified based on the chunk id. 2179 */ 2180 2181 switch (param.p->type) { 2182 case SCTP_PARAM_IPV4_ADDRESS: 2183 case SCTP_PARAM_IPV6_ADDRESS: 2184 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2185 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2186 case SCTP_PARAM_STATE_COOKIE: 2187 case SCTP_PARAM_HEARTBEAT_INFO: 2188 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2189 case SCTP_PARAM_ECN_CAPABLE: 2190 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2191 break; 2192 2193 case SCTP_PARAM_SUPPORTED_EXT: 2194 if (!sctp_verify_ext_param(net, param)) 2195 return SCTP_IERROR_ABORT; 2196 break; 2197 2198 case SCTP_PARAM_SET_PRIMARY: 2199 if (net->sctp.addip_enable) 2200 break; 2201 goto fallthrough; 2202 2203 case SCTP_PARAM_HOST_NAME_ADDRESS: 2204 /* Tell the peer, we won't support this param. */ 2205 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2206 retval = SCTP_IERROR_ABORT; 2207 break; 2208 2209 case SCTP_PARAM_FWD_TSN_SUPPORT: 2210 if (ep->prsctp_enable) 2211 break; 2212 goto fallthrough; 2213 2214 case SCTP_PARAM_RANDOM: 2215 if (!ep->auth_enable) 2216 goto fallthrough; 2217 2218 /* SCTP-AUTH: Secion 6.1 2219 * If the random number is not 32 byte long the association 2220 * MUST be aborted. The ABORT chunk SHOULD contain the error 2221 * cause 'Protocol Violation'. 2222 */ 2223 if (SCTP_AUTH_RANDOM_LENGTH != 2224 ntohs(param.p->length) - sizeof(struct sctp_paramhdr)) { 2225 sctp_process_inv_paramlength(asoc, param.p, 2226 chunk, err_chunk); 2227 retval = SCTP_IERROR_ABORT; 2228 } 2229 break; 2230 2231 case SCTP_PARAM_CHUNKS: 2232 if (!ep->auth_enable) 2233 goto fallthrough; 2234 2235 /* SCTP-AUTH: Section 3.2 2236 * The CHUNKS parameter MUST be included once in the INIT or 2237 * INIT-ACK chunk if the sender wants to receive authenticated 2238 * chunks. Its maximum length is 260 bytes. 2239 */ 2240 if (260 < ntohs(param.p->length)) { 2241 sctp_process_inv_paramlength(asoc, param.p, 2242 chunk, err_chunk); 2243 retval = SCTP_IERROR_ABORT; 2244 } 2245 break; 2246 2247 case SCTP_PARAM_HMAC_ALGO: 2248 if (!ep->auth_enable) 2249 goto fallthrough; 2250 2251 hmacs = (struct sctp_hmac_algo_param *)param.p; 2252 n_elt = (ntohs(param.p->length) - 2253 sizeof(struct sctp_paramhdr)) >> 1; 2254 2255 /* SCTP-AUTH: Section 6.1 2256 * The HMAC algorithm based on SHA-1 MUST be supported and 2257 * included in the HMAC-ALGO parameter. 2258 */ 2259 for (i = 0; i < n_elt; i++) { 2260 id = ntohs(hmacs->hmac_ids[i]); 2261 2262 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2263 break; 2264 } 2265 2266 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2267 sctp_process_inv_paramlength(asoc, param.p, chunk, 2268 err_chunk); 2269 retval = SCTP_IERROR_ABORT; 2270 } 2271 break; 2272 fallthrough: 2273 default: 2274 pr_debug("%s: unrecognized param:%d for chunk:%d\n", 2275 __func__, ntohs(param.p->type), cid); 2276 2277 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2278 break; 2279 } 2280 return retval; 2281 } 2282 2283 /* Verify the INIT packet before we process it. */ 2284 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 2285 const struct sctp_association *asoc, enum sctp_cid cid, 2286 struct sctp_init_chunk *peer_init, 2287 struct sctp_chunk *chunk, struct sctp_chunk **errp) 2288 { 2289 union sctp_params param; 2290 bool has_cookie = false; 2291 int result; 2292 2293 /* Check for missing mandatory parameters. Note: Initial TSN is 2294 * also mandatory, but is not checked here since the valid range 2295 * is 0..2**32-1. RFC4960, section 3.3.3. 2296 */ 2297 if (peer_init->init_hdr.num_outbound_streams == 0 || 2298 peer_init->init_hdr.num_inbound_streams == 0 || 2299 peer_init->init_hdr.init_tag == 0 || 2300 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) 2301 return sctp_process_inv_mandatory(asoc, chunk, errp); 2302 2303 sctp_walk_params(param, peer_init, init_hdr.params) { 2304 if (param.p->type == SCTP_PARAM_STATE_COOKIE) 2305 has_cookie = true; 2306 } 2307 2308 /* There is a possibility that a parameter length was bad and 2309 * in that case we would have stoped walking the parameters. 2310 * The current param.p would point at the bad one. 2311 * Current consensus on the mailing list is to generate a PROTOCOL 2312 * VIOLATION error. We build the ERROR chunk here and let the normal 2313 * error handling code build and send the packet. 2314 */ 2315 if (param.v != (void *)chunk->chunk_end) 2316 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2317 2318 /* The only missing mandatory param possible today is 2319 * the state cookie for an INIT-ACK chunk. 2320 */ 2321 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2322 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2323 chunk, errp); 2324 2325 /* Verify all the variable length parameters */ 2326 sctp_walk_params(param, peer_init, init_hdr.params) { 2327 result = sctp_verify_param(net, ep, asoc, param, cid, 2328 chunk, errp); 2329 switch (result) { 2330 case SCTP_IERROR_ABORT: 2331 case SCTP_IERROR_NOMEM: 2332 return 0; 2333 case SCTP_IERROR_ERROR: 2334 return 1; 2335 case SCTP_IERROR_NO_ERROR: 2336 default: 2337 break; 2338 } 2339 2340 } /* for (loop through all parameters) */ 2341 2342 return 1; 2343 } 2344 2345 /* Unpack the parameters in an INIT packet into an association. 2346 * Returns 0 on failure, else success. 2347 * FIXME: This is an association method. 2348 */ 2349 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2350 const union sctp_addr *peer_addr, 2351 struct sctp_init_chunk *peer_init, gfp_t gfp) 2352 { 2353 struct net *net = sock_net(asoc->base.sk); 2354 struct sctp_transport *transport; 2355 struct list_head *pos, *temp; 2356 union sctp_params param; 2357 union sctp_addr addr; 2358 struct sctp_af *af; 2359 int src_match = 0; 2360 char *cookie; 2361 2362 /* We must include the address that the INIT packet came from. 2363 * This is the only address that matters for an INIT packet. 2364 * When processing a COOKIE ECHO, we retrieve the from address 2365 * of the INIT from the cookie. 2366 */ 2367 2368 /* This implementation defaults to making the first transport 2369 * added as the primary transport. The source address seems to 2370 * be a a better choice than any of the embedded addresses. 2371 */ 2372 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2373 goto nomem; 2374 2375 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2376 src_match = 1; 2377 2378 /* Process the initialization parameters. */ 2379 sctp_walk_params(param, peer_init, init_hdr.params) { 2380 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2381 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2382 af = sctp_get_af_specific(param_type2af(param.p->type)); 2383 af->from_addr_param(&addr, param.addr, 2384 chunk->sctp_hdr->source, 0); 2385 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2386 src_match = 1; 2387 } 2388 2389 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2390 goto clean_up; 2391 } 2392 2393 /* source address of chunk may not match any valid address */ 2394 if (!src_match) 2395 goto clean_up; 2396 2397 /* AUTH: After processing the parameters, make sure that we 2398 * have all the required info to potentially do authentications. 2399 */ 2400 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2401 !asoc->peer.peer_hmacs)) 2402 asoc->peer.auth_capable = 0; 2403 2404 /* In a non-backward compatible mode, if the peer claims 2405 * support for ADD-IP but not AUTH, the ADD-IP spec states 2406 * that we MUST ABORT the association. Section 6. The section 2407 * also give us an option to silently ignore the packet, which 2408 * is what we'll do here. 2409 */ 2410 if (!net->sctp.addip_noauth && 2411 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2412 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2413 SCTP_PARAM_DEL_IP | 2414 SCTP_PARAM_SET_PRIMARY); 2415 asoc->peer.asconf_capable = 0; 2416 goto clean_up; 2417 } 2418 2419 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2420 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2421 transport = list_entry(pos, struct sctp_transport, transports); 2422 if (transport->state == SCTP_UNKNOWN) { 2423 sctp_assoc_rm_peer(asoc, transport); 2424 } 2425 } 2426 2427 /* The fixed INIT headers are always in network byte 2428 * order. 2429 */ 2430 asoc->peer.i.init_tag = 2431 ntohl(peer_init->init_hdr.init_tag); 2432 asoc->peer.i.a_rwnd = 2433 ntohl(peer_init->init_hdr.a_rwnd); 2434 asoc->peer.i.num_outbound_streams = 2435 ntohs(peer_init->init_hdr.num_outbound_streams); 2436 asoc->peer.i.num_inbound_streams = 2437 ntohs(peer_init->init_hdr.num_inbound_streams); 2438 asoc->peer.i.initial_tsn = 2439 ntohl(peer_init->init_hdr.initial_tsn); 2440 2441 asoc->strreset_inseq = asoc->peer.i.initial_tsn; 2442 2443 /* Apply the upper bounds for output streams based on peer's 2444 * number of inbound streams. 2445 */ 2446 if (asoc->c.sinit_num_ostreams > 2447 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2448 asoc->c.sinit_num_ostreams = 2449 ntohs(peer_init->init_hdr.num_inbound_streams); 2450 } 2451 2452 if (asoc->c.sinit_max_instreams > 2453 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2454 asoc->c.sinit_max_instreams = 2455 ntohs(peer_init->init_hdr.num_outbound_streams); 2456 } 2457 2458 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2459 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2460 2461 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2462 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2463 2464 /* Copy cookie in case we need to resend COOKIE-ECHO. */ 2465 cookie = asoc->peer.cookie; 2466 if (cookie) { 2467 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp); 2468 if (!asoc->peer.cookie) 2469 goto clean_up; 2470 } 2471 2472 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2473 * high (for example, implementations MAY use the size of the receiver 2474 * advertised window). 2475 */ 2476 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2477 transports) { 2478 transport->ssthresh = asoc->peer.i.a_rwnd; 2479 } 2480 2481 /* Set up the TSN tracking pieces. */ 2482 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2483 asoc->peer.i.initial_tsn, gfp)) 2484 goto clean_up; 2485 2486 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2487 * 2488 * The stream sequence number in all the streams shall start 2489 * from 0 when the association is established. Also, when the 2490 * stream sequence number reaches the value 65535 the next 2491 * stream sequence number shall be set to 0. 2492 */ 2493 2494 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams, 2495 asoc->c.sinit_max_instreams, gfp)) 2496 goto clean_up; 2497 2498 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp)) 2499 goto clean_up; 2500 2501 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2502 * 2503 * When an endpoint has an ASCONF signaled change to be sent to the 2504 * remote endpoint it should do the following: 2505 * ... 2506 * A2) A serial number should be assigned to the Chunk. The serial 2507 * number should be a monotonically increasing number. All serial 2508 * numbers are defined to be initialized at the start of the 2509 * association to the same value as the Initial TSN. 2510 */ 2511 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2512 return 1; 2513 2514 clean_up: 2515 /* Release the transport structures. */ 2516 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2517 transport = list_entry(pos, struct sctp_transport, transports); 2518 if (transport->state != SCTP_ACTIVE) 2519 sctp_assoc_rm_peer(asoc, transport); 2520 } 2521 2522 nomem: 2523 return 0; 2524 } 2525 2526 2527 /* Update asoc with the option described in param. 2528 * 2529 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2530 * 2531 * asoc is the association to update. 2532 * param is the variable length parameter to use for update. 2533 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2534 * If the current packet is an INIT we want to minimize the amount of 2535 * work we do. In particular, we should not build transport 2536 * structures for the addresses. 2537 */ 2538 static int sctp_process_param(struct sctp_association *asoc, 2539 union sctp_params param, 2540 const union sctp_addr *peer_addr, 2541 gfp_t gfp) 2542 { 2543 struct net *net = sock_net(asoc->base.sk); 2544 struct sctp_endpoint *ep = asoc->ep; 2545 union sctp_addr_param *addr_param; 2546 struct sctp_transport *t; 2547 enum sctp_scope scope; 2548 union sctp_addr addr; 2549 struct sctp_af *af; 2550 int retval = 1, i; 2551 u32 stale; 2552 __u16 sat; 2553 2554 /* We maintain all INIT parameters in network byte order all the 2555 * time. This allows us to not worry about whether the parameters 2556 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2557 */ 2558 switch (param.p->type) { 2559 case SCTP_PARAM_IPV6_ADDRESS: 2560 if (PF_INET6 != asoc->base.sk->sk_family) 2561 break; 2562 goto do_addr_param; 2563 2564 case SCTP_PARAM_IPV4_ADDRESS: 2565 /* v4 addresses are not allowed on v6-only socket */ 2566 if (ipv6_only_sock(asoc->base.sk)) 2567 break; 2568 do_addr_param: 2569 af = sctp_get_af_specific(param_type2af(param.p->type)); 2570 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); 2571 scope = sctp_scope(peer_addr); 2572 if (sctp_in_scope(net, &addr, scope)) 2573 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2574 return 0; 2575 break; 2576 2577 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2578 if (!net->sctp.cookie_preserve_enable) 2579 break; 2580 2581 stale = ntohl(param.life->lifespan_increment); 2582 2583 /* Suggested Cookie Life span increment's unit is msec, 2584 * (1/1000sec). 2585 */ 2586 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale); 2587 break; 2588 2589 case SCTP_PARAM_HOST_NAME_ADDRESS: 2590 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__); 2591 break; 2592 2593 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2594 /* Turn off the default values first so we'll know which 2595 * ones are really set by the peer. 2596 */ 2597 asoc->peer.ipv4_address = 0; 2598 asoc->peer.ipv6_address = 0; 2599 2600 /* Assume that peer supports the address family 2601 * by which it sends a packet. 2602 */ 2603 if (peer_addr->sa.sa_family == AF_INET6) 2604 asoc->peer.ipv6_address = 1; 2605 else if (peer_addr->sa.sa_family == AF_INET) 2606 asoc->peer.ipv4_address = 1; 2607 2608 /* Cycle through address types; avoid divide by 0. */ 2609 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2610 if (sat) 2611 sat /= sizeof(__u16); 2612 2613 for (i = 0; i < sat; ++i) { 2614 switch (param.sat->types[i]) { 2615 case SCTP_PARAM_IPV4_ADDRESS: 2616 asoc->peer.ipv4_address = 1; 2617 break; 2618 2619 case SCTP_PARAM_IPV6_ADDRESS: 2620 if (PF_INET6 == asoc->base.sk->sk_family) 2621 asoc->peer.ipv6_address = 1; 2622 break; 2623 2624 case SCTP_PARAM_HOST_NAME_ADDRESS: 2625 asoc->peer.hostname_address = 1; 2626 break; 2627 2628 default: /* Just ignore anything else. */ 2629 break; 2630 } 2631 } 2632 break; 2633 2634 case SCTP_PARAM_STATE_COOKIE: 2635 asoc->peer.cookie_len = 2636 ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2637 asoc->peer.cookie = param.cookie->body; 2638 break; 2639 2640 case SCTP_PARAM_HEARTBEAT_INFO: 2641 /* Would be odd to receive, but it causes no problems. */ 2642 break; 2643 2644 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2645 /* Rejected during verify stage. */ 2646 break; 2647 2648 case SCTP_PARAM_ECN_CAPABLE: 2649 asoc->peer.ecn_capable = 1; 2650 break; 2651 2652 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2653 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2654 break; 2655 2656 case SCTP_PARAM_SET_PRIMARY: 2657 if (!net->sctp.addip_enable) 2658 goto fall_through; 2659 2660 addr_param = param.v + sizeof(struct sctp_addip_param); 2661 2662 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 2663 if (af == NULL) 2664 break; 2665 2666 af->from_addr_param(&addr, addr_param, 2667 htons(asoc->peer.port), 0); 2668 2669 /* if the address is invalid, we can't process it. 2670 * XXX: see spec for what to do. 2671 */ 2672 if (!af->addr_valid(&addr, NULL, NULL)) 2673 break; 2674 2675 t = sctp_assoc_lookup_paddr(asoc, &addr); 2676 if (!t) 2677 break; 2678 2679 sctp_assoc_set_primary(asoc, t); 2680 break; 2681 2682 case SCTP_PARAM_SUPPORTED_EXT: 2683 sctp_process_ext_param(asoc, param); 2684 break; 2685 2686 case SCTP_PARAM_FWD_TSN_SUPPORT: 2687 if (asoc->prsctp_enable) { 2688 asoc->peer.prsctp_capable = 1; 2689 break; 2690 } 2691 /* Fall Through */ 2692 goto fall_through; 2693 2694 case SCTP_PARAM_RANDOM: 2695 if (!ep->auth_enable) 2696 goto fall_through; 2697 2698 /* Save peer's random parameter */ 2699 asoc->peer.peer_random = kmemdup(param.p, 2700 ntohs(param.p->length), gfp); 2701 if (!asoc->peer.peer_random) { 2702 retval = 0; 2703 break; 2704 } 2705 break; 2706 2707 case SCTP_PARAM_HMAC_ALGO: 2708 if (!ep->auth_enable) 2709 goto fall_through; 2710 2711 /* Save peer's HMAC list */ 2712 asoc->peer.peer_hmacs = kmemdup(param.p, 2713 ntohs(param.p->length), gfp); 2714 if (!asoc->peer.peer_hmacs) { 2715 retval = 0; 2716 break; 2717 } 2718 2719 /* Set the default HMAC the peer requested*/ 2720 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2721 break; 2722 2723 case SCTP_PARAM_CHUNKS: 2724 if (!ep->auth_enable) 2725 goto fall_through; 2726 2727 asoc->peer.peer_chunks = kmemdup(param.p, 2728 ntohs(param.p->length), gfp); 2729 if (!asoc->peer.peer_chunks) 2730 retval = 0; 2731 break; 2732 fall_through: 2733 default: 2734 /* Any unrecognized parameters should have been caught 2735 * and handled by sctp_verify_param() which should be 2736 * called prior to this routine. Simply log the error 2737 * here. 2738 */ 2739 pr_debug("%s: ignoring param:%d for association:%p.\n", 2740 __func__, ntohs(param.p->type), asoc); 2741 break; 2742 } 2743 2744 return retval; 2745 } 2746 2747 /* Select a new verification tag. */ 2748 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2749 { 2750 /* I believe that this random number generator complies with RFC1750. 2751 * A tag of 0 is reserved for special cases (e.g. INIT). 2752 */ 2753 __u32 x; 2754 2755 do { 2756 get_random_bytes(&x, sizeof(__u32)); 2757 } while (x == 0); 2758 2759 return x; 2760 } 2761 2762 /* Select an initial TSN to send during startup. */ 2763 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2764 { 2765 __u32 retval; 2766 2767 get_random_bytes(&retval, sizeof(__u32)); 2768 return retval; 2769 } 2770 2771 /* 2772 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2773 * 0 1 2 3 2774 * 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 2775 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2776 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2777 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2778 * | Serial Number | 2779 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2780 * | Address Parameter | 2781 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2782 * | ASCONF Parameter #1 | 2783 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2784 * \ \ 2785 * / .... / 2786 * \ \ 2787 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2788 * | ASCONF Parameter #N | 2789 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2790 * 2791 * Address Parameter and other parameter will not be wrapped in this function 2792 */ 2793 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2794 union sctp_addr *addr, 2795 int vparam_len) 2796 { 2797 struct sctp_addiphdr asconf; 2798 struct sctp_chunk *retval; 2799 int length = sizeof(asconf) + vparam_len; 2800 union sctp_addr_param addrparam; 2801 int addrlen; 2802 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2803 2804 addrlen = af->to_addr_param(addr, &addrparam); 2805 if (!addrlen) 2806 return NULL; 2807 length += addrlen; 2808 2809 /* Create the chunk. */ 2810 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length, 2811 GFP_ATOMIC); 2812 if (!retval) 2813 return NULL; 2814 2815 asconf.serial = htonl(asoc->addip_serial++); 2816 2817 retval->subh.addip_hdr = 2818 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2819 retval->param_hdr.v = 2820 sctp_addto_chunk(retval, addrlen, &addrparam); 2821 2822 return retval; 2823 } 2824 2825 /* ADDIP 2826 * 3.2.1 Add IP Address 2827 * 0 1 2 3 2828 * 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 2829 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2830 * | Type = 0xC001 | Length = Variable | 2831 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2832 * | ASCONF-Request Correlation ID | 2833 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2834 * | Address Parameter | 2835 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2836 * 2837 * 3.2.2 Delete IP Address 2838 * 0 1 2 3 2839 * 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 2840 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2841 * | Type = 0xC002 | Length = Variable | 2842 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2843 * | ASCONF-Request Correlation ID | 2844 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2845 * | Address Parameter | 2846 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2847 * 2848 */ 2849 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2850 union sctp_addr *laddr, 2851 struct sockaddr *addrs, 2852 int addrcnt, __be16 flags) 2853 { 2854 union sctp_addr_param addr_param; 2855 struct sctp_addip_param param; 2856 int paramlen = sizeof(param); 2857 struct sctp_chunk *retval; 2858 int addr_param_len = 0; 2859 union sctp_addr *addr; 2860 int totallen = 0, i; 2861 int del_pickup = 0; 2862 struct sctp_af *af; 2863 void *addr_buf; 2864 2865 /* Get total length of all the address parameters. */ 2866 addr_buf = addrs; 2867 for (i = 0; i < addrcnt; i++) { 2868 addr = addr_buf; 2869 af = sctp_get_af_specific(addr->v4.sin_family); 2870 addr_param_len = af->to_addr_param(addr, &addr_param); 2871 2872 totallen += paramlen; 2873 totallen += addr_param_len; 2874 2875 addr_buf += af->sockaddr_len; 2876 if (asoc->asconf_addr_del_pending && !del_pickup) { 2877 /* reuse the parameter length from the same scope one */ 2878 totallen += paramlen; 2879 totallen += addr_param_len; 2880 del_pickup = 1; 2881 2882 pr_debug("%s: picked same-scope del_pending addr, " 2883 "totallen for all addresses is %d\n", 2884 __func__, totallen); 2885 } 2886 } 2887 2888 /* Create an asconf chunk with the required length. */ 2889 retval = sctp_make_asconf(asoc, laddr, totallen); 2890 if (!retval) 2891 return NULL; 2892 2893 /* Add the address parameters to the asconf chunk. */ 2894 addr_buf = addrs; 2895 for (i = 0; i < addrcnt; i++) { 2896 addr = addr_buf; 2897 af = sctp_get_af_specific(addr->v4.sin_family); 2898 addr_param_len = af->to_addr_param(addr, &addr_param); 2899 param.param_hdr.type = flags; 2900 param.param_hdr.length = htons(paramlen + addr_param_len); 2901 param.crr_id = htonl(i); 2902 2903 sctp_addto_chunk(retval, paramlen, ¶m); 2904 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2905 2906 addr_buf += af->sockaddr_len; 2907 } 2908 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2909 addr = asoc->asconf_addr_del_pending; 2910 af = sctp_get_af_specific(addr->v4.sin_family); 2911 addr_param_len = af->to_addr_param(addr, &addr_param); 2912 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2913 param.param_hdr.length = htons(paramlen + addr_param_len); 2914 param.crr_id = htonl(i); 2915 2916 sctp_addto_chunk(retval, paramlen, ¶m); 2917 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2918 } 2919 return retval; 2920 } 2921 2922 /* ADDIP 2923 * 3.2.4 Set Primary IP Address 2924 * 0 1 2 3 2925 * 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 2926 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2927 * | Type =0xC004 | Length = Variable | 2928 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2929 * | ASCONF-Request Correlation ID | 2930 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2931 * | Address Parameter | 2932 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2933 * 2934 * Create an ASCONF chunk with Set Primary IP address parameter. 2935 */ 2936 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2937 union sctp_addr *addr) 2938 { 2939 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2940 union sctp_addr_param addrparam; 2941 struct sctp_addip_param param; 2942 struct sctp_chunk *retval; 2943 int len = sizeof(param); 2944 int addrlen; 2945 2946 addrlen = af->to_addr_param(addr, &addrparam); 2947 if (!addrlen) 2948 return NULL; 2949 len += addrlen; 2950 2951 /* Create the chunk and make asconf header. */ 2952 retval = sctp_make_asconf(asoc, addr, len); 2953 if (!retval) 2954 return NULL; 2955 2956 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2957 param.param_hdr.length = htons(len); 2958 param.crr_id = 0; 2959 2960 sctp_addto_chunk(retval, sizeof(param), ¶m); 2961 sctp_addto_chunk(retval, addrlen, &addrparam); 2962 2963 return retval; 2964 } 2965 2966 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2967 * 0 1 2 3 2968 * 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 2969 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2970 * | Type = 0x80 | Chunk Flags | Chunk Length | 2971 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2972 * | Serial Number | 2973 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2974 * | ASCONF Parameter Response#1 | 2975 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2976 * \ \ 2977 * / .... / 2978 * \ \ 2979 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2980 * | ASCONF Parameter Response#N | 2981 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2982 * 2983 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2984 */ 2985 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2986 __u32 serial, int vparam_len) 2987 { 2988 struct sctp_addiphdr asconf; 2989 struct sctp_chunk *retval; 2990 int length = sizeof(asconf) + vparam_len; 2991 2992 /* Create the chunk. */ 2993 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length, 2994 GFP_ATOMIC); 2995 if (!retval) 2996 return NULL; 2997 2998 asconf.serial = htonl(serial); 2999 3000 retval->subh.addip_hdr = 3001 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 3002 3003 return retval; 3004 } 3005 3006 /* Add response parameters to an ASCONF_ACK chunk. */ 3007 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 3008 __be16 err_code, 3009 struct sctp_addip_param *asconf_param) 3010 { 3011 struct sctp_addip_param ack_param; 3012 struct sctp_errhdr err_param; 3013 int asconf_param_len = 0; 3014 int err_param_len = 0; 3015 __be16 response_type; 3016 3017 if (SCTP_ERROR_NO_ERROR == err_code) { 3018 response_type = SCTP_PARAM_SUCCESS_REPORT; 3019 } else { 3020 response_type = SCTP_PARAM_ERR_CAUSE; 3021 err_param_len = sizeof(err_param); 3022 if (asconf_param) 3023 asconf_param_len = 3024 ntohs(asconf_param->param_hdr.length); 3025 } 3026 3027 /* Add Success Indication or Error Cause Indication parameter. */ 3028 ack_param.param_hdr.type = response_type; 3029 ack_param.param_hdr.length = htons(sizeof(ack_param) + 3030 err_param_len + 3031 asconf_param_len); 3032 ack_param.crr_id = crr_id; 3033 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 3034 3035 if (SCTP_ERROR_NO_ERROR == err_code) 3036 return; 3037 3038 /* Add Error Cause parameter. */ 3039 err_param.cause = err_code; 3040 err_param.length = htons(err_param_len + asconf_param_len); 3041 sctp_addto_chunk(chunk, err_param_len, &err_param); 3042 3043 /* Add the failed TLV copied from ASCONF chunk. */ 3044 if (asconf_param) 3045 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 3046 } 3047 3048 /* Process a asconf parameter. */ 3049 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 3050 struct sctp_chunk *asconf, 3051 struct sctp_addip_param *asconf_param) 3052 { 3053 union sctp_addr_param *addr_param; 3054 struct sctp_transport *peer; 3055 union sctp_addr addr; 3056 struct sctp_af *af; 3057 3058 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3059 3060 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 3061 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 3062 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 3063 return SCTP_ERROR_UNKNOWN_PARAM; 3064 3065 switch (addr_param->p.type) { 3066 case SCTP_PARAM_IPV6_ADDRESS: 3067 if (!asoc->peer.ipv6_address) 3068 return SCTP_ERROR_DNS_FAILED; 3069 break; 3070 case SCTP_PARAM_IPV4_ADDRESS: 3071 if (!asoc->peer.ipv4_address) 3072 return SCTP_ERROR_DNS_FAILED; 3073 break; 3074 default: 3075 return SCTP_ERROR_DNS_FAILED; 3076 } 3077 3078 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3079 if (unlikely(!af)) 3080 return SCTP_ERROR_DNS_FAILED; 3081 3082 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); 3083 3084 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3085 * or multicast address. 3086 * (note: wildcard is permitted and requires special handling so 3087 * make sure we check for that) 3088 */ 3089 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3090 return SCTP_ERROR_DNS_FAILED; 3091 3092 switch (asconf_param->param_hdr.type) { 3093 case SCTP_PARAM_ADD_IP: 3094 /* Section 4.2.1: 3095 * If the address 0.0.0.0 or ::0 is provided, the source 3096 * address of the packet MUST be added. 3097 */ 3098 if (af->is_any(&addr)) 3099 memcpy(&addr, &asconf->source, sizeof(addr)); 3100 3101 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3102 * request and does not have the local resources to add this 3103 * new address to the association, it MUST return an Error 3104 * Cause TLV set to the new error code 'Operation Refused 3105 * Due to Resource Shortage'. 3106 */ 3107 3108 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3109 if (!peer) 3110 return SCTP_ERROR_RSRC_LOW; 3111 3112 /* Start the heartbeat timer. */ 3113 sctp_transport_reset_hb_timer(peer); 3114 asoc->new_transport = peer; 3115 break; 3116 case SCTP_PARAM_DEL_IP: 3117 /* ADDIP 4.3 D7) If a request is received to delete the 3118 * last remaining IP address of a peer endpoint, the receiver 3119 * MUST send an Error Cause TLV with the error cause set to the 3120 * new error code 'Request to Delete Last Remaining IP Address'. 3121 */ 3122 if (asoc->peer.transport_count == 1) 3123 return SCTP_ERROR_DEL_LAST_IP; 3124 3125 /* ADDIP 4.3 D8) If a request is received to delete an IP 3126 * address which is also the source address of the IP packet 3127 * which contained the ASCONF chunk, the receiver MUST reject 3128 * this request. To reject the request the receiver MUST send 3129 * an Error Cause TLV set to the new error code 'Request to 3130 * Delete Source IP Address' 3131 */ 3132 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3133 return SCTP_ERROR_DEL_SRC_IP; 3134 3135 /* Section 4.2.2 3136 * If the address 0.0.0.0 or ::0 is provided, all 3137 * addresses of the peer except the source address of the 3138 * packet MUST be deleted. 3139 */ 3140 if (af->is_any(&addr)) { 3141 sctp_assoc_set_primary(asoc, asconf->transport); 3142 sctp_assoc_del_nonprimary_peers(asoc, 3143 asconf->transport); 3144 return SCTP_ERROR_NO_ERROR; 3145 } 3146 3147 /* If the address is not part of the association, the 3148 * ASCONF-ACK with Error Cause Indication Parameter 3149 * which including cause of Unresolvable Address should 3150 * be sent. 3151 */ 3152 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3153 if (!peer) 3154 return SCTP_ERROR_DNS_FAILED; 3155 3156 sctp_assoc_rm_peer(asoc, peer); 3157 break; 3158 case SCTP_PARAM_SET_PRIMARY: 3159 /* ADDIP Section 4.2.4 3160 * If the address 0.0.0.0 or ::0 is provided, the receiver 3161 * MAY mark the source address of the packet as its 3162 * primary. 3163 */ 3164 if (af->is_any(&addr)) 3165 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr)); 3166 3167 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3168 if (!peer) 3169 return SCTP_ERROR_DNS_FAILED; 3170 3171 sctp_assoc_set_primary(asoc, peer); 3172 break; 3173 } 3174 3175 return SCTP_ERROR_NO_ERROR; 3176 } 3177 3178 /* Verify the ASCONF packet before we process it. */ 3179 bool sctp_verify_asconf(const struct sctp_association *asoc, 3180 struct sctp_chunk *chunk, bool addr_param_needed, 3181 struct sctp_paramhdr **errp) 3182 { 3183 struct sctp_addip_chunk *addip; 3184 bool addr_param_seen = false; 3185 union sctp_params param; 3186 3187 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr; 3188 sctp_walk_params(param, addip, addip_hdr.params) { 3189 size_t length = ntohs(param.p->length); 3190 3191 *errp = param.p; 3192 switch (param.p->type) { 3193 case SCTP_PARAM_ERR_CAUSE: 3194 break; 3195 case SCTP_PARAM_IPV4_ADDRESS: 3196 if (length != sizeof(struct sctp_ipv4addr_param)) 3197 return false; 3198 /* ensure there is only one addr param and it's in the 3199 * beginning of addip_hdr params, or we reject it. 3200 */ 3201 if (param.v != addip->addip_hdr.params) 3202 return false; 3203 addr_param_seen = true; 3204 break; 3205 case SCTP_PARAM_IPV6_ADDRESS: 3206 if (length != sizeof(struct sctp_ipv6addr_param)) 3207 return false; 3208 if (param.v != addip->addip_hdr.params) 3209 return false; 3210 addr_param_seen = true; 3211 break; 3212 case SCTP_PARAM_ADD_IP: 3213 case SCTP_PARAM_DEL_IP: 3214 case SCTP_PARAM_SET_PRIMARY: 3215 /* In ASCONF chunks, these need to be first. */ 3216 if (addr_param_needed && !addr_param_seen) 3217 return false; 3218 length = ntohs(param.addip->param_hdr.length); 3219 if (length < sizeof(struct sctp_addip_param) + 3220 sizeof(**errp)) 3221 return false; 3222 break; 3223 case SCTP_PARAM_SUCCESS_REPORT: 3224 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3225 if (length != sizeof(struct sctp_addip_param)) 3226 return false; 3227 break; 3228 default: 3229 /* This is unkown to us, reject! */ 3230 return false; 3231 } 3232 } 3233 3234 /* Remaining sanity checks. */ 3235 if (addr_param_needed && !addr_param_seen) 3236 return false; 3237 if (!addr_param_needed && addr_param_seen) 3238 return false; 3239 if (param.v != chunk->chunk_end) 3240 return false; 3241 3242 return true; 3243 } 3244 3245 /* Process an incoming ASCONF chunk with the next expected serial no. and 3246 * return an ASCONF_ACK chunk to be sent in response. 3247 */ 3248 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3249 struct sctp_chunk *asconf) 3250 { 3251 union sctp_addr_param *addr_param; 3252 struct sctp_addip_chunk *addip; 3253 struct sctp_chunk *asconf_ack; 3254 bool all_param_pass = true; 3255 struct sctp_addiphdr *hdr; 3256 int length = 0, chunk_len; 3257 union sctp_params param; 3258 __be16 err_code; 3259 __u32 serial; 3260 3261 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr; 3262 chunk_len = ntohs(asconf->chunk_hdr->length) - 3263 sizeof(struct sctp_chunkhdr); 3264 hdr = (struct sctp_addiphdr *)asconf->skb->data; 3265 serial = ntohl(hdr->serial); 3266 3267 /* Skip the addiphdr and store a pointer to address parameter. */ 3268 length = sizeof(*hdr); 3269 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3270 chunk_len -= length; 3271 3272 /* Skip the address parameter and store a pointer to the first 3273 * asconf parameter. 3274 */ 3275 length = ntohs(addr_param->p.length); 3276 chunk_len -= length; 3277 3278 /* create an ASCONF_ACK chunk. 3279 * Based on the definitions of parameters, we know that the size of 3280 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3281 * parameters. 3282 */ 3283 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3284 if (!asconf_ack) 3285 goto done; 3286 3287 /* Process the TLVs contained within the ASCONF chunk. */ 3288 sctp_walk_params(param, addip, addip_hdr.params) { 3289 /* Skip preceeding address parameters. */ 3290 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 3291 param.p->type == SCTP_PARAM_IPV6_ADDRESS) 3292 continue; 3293 3294 err_code = sctp_process_asconf_param(asoc, asconf, 3295 param.addip); 3296 /* ADDIP 4.1 A7) 3297 * If an error response is received for a TLV parameter, 3298 * all TLVs with no response before the failed TLV are 3299 * considered successful if not reported. All TLVs after 3300 * the failed response are considered unsuccessful unless 3301 * a specific success indication is present for the parameter. 3302 */ 3303 if (err_code != SCTP_ERROR_NO_ERROR) 3304 all_param_pass = false; 3305 if (!all_param_pass) 3306 sctp_add_asconf_response(asconf_ack, param.addip->crr_id, 3307 err_code, param.addip); 3308 3309 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3310 * an IP address sends an 'Out of Resource' in its response, it 3311 * MUST also fail any subsequent add or delete requests bundled 3312 * in the ASCONF. 3313 */ 3314 if (err_code == SCTP_ERROR_RSRC_LOW) 3315 goto done; 3316 } 3317 done: 3318 asoc->peer.addip_serial++; 3319 3320 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3321 * after freeing the reference to old asconf ack if any. 3322 */ 3323 if (asconf_ack) { 3324 sctp_chunk_hold(asconf_ack); 3325 list_add_tail(&asconf_ack->transmitted_list, 3326 &asoc->asconf_ack_list); 3327 } 3328 3329 return asconf_ack; 3330 } 3331 3332 /* Process a asconf parameter that is successfully acked. */ 3333 static void sctp_asconf_param_success(struct sctp_association *asoc, 3334 struct sctp_addip_param *asconf_param) 3335 { 3336 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3337 union sctp_addr_param *addr_param; 3338 struct sctp_sockaddr_entry *saddr; 3339 struct sctp_transport *transport; 3340 union sctp_addr addr; 3341 struct sctp_af *af; 3342 3343 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3344 3345 /* We have checked the packet before, so we do not check again. */ 3346 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3347 af->from_addr_param(&addr, addr_param, htons(bp->port), 0); 3348 3349 switch (asconf_param->param_hdr.type) { 3350 case SCTP_PARAM_ADD_IP: 3351 /* This is always done in BH context with a socket lock 3352 * held, so the list can not change. 3353 */ 3354 local_bh_disable(); 3355 list_for_each_entry(saddr, &bp->address_list, list) { 3356 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3357 saddr->state = SCTP_ADDR_SRC; 3358 } 3359 local_bh_enable(); 3360 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3361 transports) { 3362 sctp_transport_dst_release(transport); 3363 } 3364 break; 3365 case SCTP_PARAM_DEL_IP: 3366 local_bh_disable(); 3367 sctp_del_bind_addr(bp, &addr); 3368 if (asoc->asconf_addr_del_pending != NULL && 3369 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3370 kfree(asoc->asconf_addr_del_pending); 3371 asoc->asconf_addr_del_pending = NULL; 3372 } 3373 local_bh_enable(); 3374 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3375 transports) { 3376 sctp_transport_dst_release(transport); 3377 } 3378 break; 3379 default: 3380 break; 3381 } 3382 } 3383 3384 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3385 * for the given asconf parameter. If there is no response for this parameter, 3386 * return the error code based on the third argument 'no_err'. 3387 * ADDIP 4.1 3388 * A7) If an error response is received for a TLV parameter, all TLVs with no 3389 * response before the failed TLV are considered successful if not reported. 3390 * All TLVs after the failed response are considered unsuccessful unless a 3391 * specific success indication is present for the parameter. 3392 */ 3393 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3394 struct sctp_addip_param *asconf_param, 3395 int no_err) 3396 { 3397 struct sctp_addip_param *asconf_ack_param; 3398 struct sctp_errhdr *err_param; 3399 int asconf_ack_len; 3400 __be16 err_code; 3401 int length; 3402 3403 if (no_err) 3404 err_code = SCTP_ERROR_NO_ERROR; 3405 else 3406 err_code = SCTP_ERROR_REQ_REFUSED; 3407 3408 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3409 sizeof(struct sctp_chunkhdr); 3410 3411 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3412 * the first asconf_ack parameter. 3413 */ 3414 length = sizeof(struct sctp_addiphdr); 3415 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data + 3416 length); 3417 asconf_ack_len -= length; 3418 3419 while (asconf_ack_len > 0) { 3420 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3421 switch (asconf_ack_param->param_hdr.type) { 3422 case SCTP_PARAM_SUCCESS_REPORT: 3423 return SCTP_ERROR_NO_ERROR; 3424 case SCTP_PARAM_ERR_CAUSE: 3425 length = sizeof(*asconf_ack_param); 3426 err_param = (void *)asconf_ack_param + length; 3427 asconf_ack_len -= length; 3428 if (asconf_ack_len > 0) 3429 return err_param->cause; 3430 else 3431 return SCTP_ERROR_INV_PARAM; 3432 break; 3433 default: 3434 return SCTP_ERROR_INV_PARAM; 3435 } 3436 } 3437 3438 length = ntohs(asconf_ack_param->param_hdr.length); 3439 asconf_ack_param = (void *)asconf_ack_param + length; 3440 asconf_ack_len -= length; 3441 } 3442 3443 return err_code; 3444 } 3445 3446 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3447 int sctp_process_asconf_ack(struct sctp_association *asoc, 3448 struct sctp_chunk *asconf_ack) 3449 { 3450 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3451 struct sctp_addip_param *asconf_param; 3452 __be16 err_code = SCTP_ERROR_NO_ERROR; 3453 union sctp_addr_param *addr_param; 3454 int asconf_len = asconf->skb->len; 3455 int all_param_pass = 0; 3456 int length = 0; 3457 int no_err = 1; 3458 int retval = 0; 3459 3460 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3461 * a pointer to address parameter. 3462 */ 3463 length = sizeof(struct sctp_addip_chunk); 3464 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3465 asconf_len -= length; 3466 3467 /* Skip the address parameter in the last asconf sent and store a 3468 * pointer to the first asconf parameter. 3469 */ 3470 length = ntohs(addr_param->p.length); 3471 asconf_param = (void *)addr_param + length; 3472 asconf_len -= length; 3473 3474 /* ADDIP 4.1 3475 * A8) If there is no response(s) to specific TLV parameter(s), and no 3476 * failures are indicated, then all request(s) are considered 3477 * successful. 3478 */ 3479 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr)) 3480 all_param_pass = 1; 3481 3482 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3483 while (asconf_len > 0) { 3484 if (all_param_pass) 3485 err_code = SCTP_ERROR_NO_ERROR; 3486 else { 3487 err_code = sctp_get_asconf_response(asconf_ack, 3488 asconf_param, 3489 no_err); 3490 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3491 no_err = 0; 3492 } 3493 3494 switch (err_code) { 3495 case SCTP_ERROR_NO_ERROR: 3496 sctp_asconf_param_success(asoc, asconf_param); 3497 break; 3498 3499 case SCTP_ERROR_RSRC_LOW: 3500 retval = 1; 3501 break; 3502 3503 case SCTP_ERROR_UNKNOWN_PARAM: 3504 /* Disable sending this type of asconf parameter in 3505 * future. 3506 */ 3507 asoc->peer.addip_disabled_mask |= 3508 asconf_param->param_hdr.type; 3509 break; 3510 3511 case SCTP_ERROR_REQ_REFUSED: 3512 case SCTP_ERROR_DEL_LAST_IP: 3513 case SCTP_ERROR_DEL_SRC_IP: 3514 default: 3515 break; 3516 } 3517 3518 /* Skip the processed asconf parameter and move to the next 3519 * one. 3520 */ 3521 length = ntohs(asconf_param->param_hdr.length); 3522 asconf_param = (void *)asconf_param + length; 3523 asconf_len -= length; 3524 } 3525 3526 if (no_err && asoc->src_out_of_asoc_ok) { 3527 asoc->src_out_of_asoc_ok = 0; 3528 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3529 } 3530 3531 /* Free the cached last sent asconf chunk. */ 3532 list_del_init(&asconf->transmitted_list); 3533 sctp_chunk_free(asconf); 3534 asoc->addip_last_asconf = NULL; 3535 3536 return retval; 3537 } 3538 3539 /* Make a FWD TSN chunk. */ 3540 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3541 __u32 new_cum_tsn, size_t nstreams, 3542 struct sctp_fwdtsn_skip *skiplist) 3543 { 3544 struct sctp_chunk *retval = NULL; 3545 struct sctp_fwdtsn_hdr ftsn_hdr; 3546 struct sctp_fwdtsn_skip skip; 3547 size_t hint; 3548 int i; 3549 3550 hint = (nstreams + 1) * sizeof(__u32); 3551 3552 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC); 3553 3554 if (!retval) 3555 return NULL; 3556 3557 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3558 retval->subh.fwdtsn_hdr = 3559 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3560 3561 for (i = 0; i < nstreams; i++) { 3562 skip.stream = skiplist[i].stream; 3563 skip.ssn = skiplist[i].ssn; 3564 sctp_addto_chunk(retval, sizeof(skip), &skip); 3565 } 3566 3567 return retval; 3568 } 3569 3570 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc, 3571 __u32 new_cum_tsn, size_t nstreams, 3572 struct sctp_ifwdtsn_skip *skiplist) 3573 { 3574 struct sctp_chunk *retval = NULL; 3575 struct sctp_ifwdtsn_hdr ftsn_hdr; 3576 size_t hint; 3577 3578 hint = (nstreams + 1) * sizeof(__u32); 3579 3580 retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint, 3581 GFP_ATOMIC); 3582 if (!retval) 3583 return NULL; 3584 3585 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3586 retval->subh.ifwdtsn_hdr = 3587 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3588 3589 sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist); 3590 3591 return retval; 3592 } 3593 3594 /* RE-CONFIG 3.1 (RE-CONFIG chunk) 3595 * 0 1 2 3 3596 * 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 3597 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3598 * | Type = 130 | Chunk Flags | Chunk Length | 3599 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3600 * \ \ 3601 * / Re-configuration Parameter / 3602 * \ \ 3603 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3604 * \ \ 3605 * / Re-configuration Parameter (optional) / 3606 * \ \ 3607 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3608 */ 3609 static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc, 3610 int length) 3611 { 3612 struct sctp_reconf_chunk *reconf; 3613 struct sctp_chunk *retval; 3614 3615 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length, 3616 GFP_ATOMIC); 3617 if (!retval) 3618 return NULL; 3619 3620 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr; 3621 retval->param_hdr.v = reconf->params; 3622 3623 return retval; 3624 } 3625 3626 /* RE-CONFIG 4.1 (STREAM OUT RESET) 3627 * 0 1 2 3 3628 * 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 3629 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3630 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N | 3631 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3632 * | Re-configuration Request Sequence Number | 3633 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3634 * | Re-configuration Response Sequence Number | 3635 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3636 * | Sender's Last Assigned TSN | 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 * RE-CONFIG 4.2 (STREAM IN RESET) 3646 * 0 1 2 3 3647 * 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 3648 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3649 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N | 3650 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3651 * | Re-configuration Request Sequence Number | 3652 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3653 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3654 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3655 * / ...... / 3656 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3657 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3658 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3659 */ 3660 struct sctp_chunk *sctp_make_strreset_req( 3661 const struct sctp_association *asoc, 3662 __u16 stream_num, __be16 *stream_list, 3663 bool out, bool in) 3664 { 3665 __u16 stream_len = stream_num * sizeof(__u16); 3666 struct sctp_strreset_outreq outreq; 3667 struct sctp_strreset_inreq inreq; 3668 struct sctp_chunk *retval; 3669 __u16 outlen, inlen; 3670 3671 outlen = (sizeof(outreq) + stream_len) * out; 3672 inlen = (sizeof(inreq) + stream_len) * in; 3673 3674 retval = sctp_make_reconf(asoc, outlen + inlen); 3675 if (!retval) 3676 return NULL; 3677 3678 if (outlen) { 3679 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST; 3680 outreq.param_hdr.length = htons(outlen); 3681 outreq.request_seq = htonl(asoc->strreset_outseq); 3682 outreq.response_seq = htonl(asoc->strreset_inseq - 1); 3683 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1); 3684 3685 sctp_addto_chunk(retval, sizeof(outreq), &outreq); 3686 3687 if (stream_len) 3688 sctp_addto_chunk(retval, stream_len, stream_list); 3689 } 3690 3691 if (inlen) { 3692 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST; 3693 inreq.param_hdr.length = htons(inlen); 3694 inreq.request_seq = htonl(asoc->strreset_outseq + out); 3695 3696 sctp_addto_chunk(retval, sizeof(inreq), &inreq); 3697 3698 if (stream_len) 3699 sctp_addto_chunk(retval, stream_len, stream_list); 3700 } 3701 3702 return retval; 3703 } 3704 3705 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL) 3706 * 0 1 2 3 3707 * 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 3708 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3709 * | Parameter Type = 15 | Parameter Length = 8 | 3710 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3711 * | Re-configuration Request Sequence Number | 3712 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3713 */ 3714 struct sctp_chunk *sctp_make_strreset_tsnreq( 3715 const struct sctp_association *asoc) 3716 { 3717 struct sctp_strreset_tsnreq tsnreq; 3718 __u16 length = sizeof(tsnreq); 3719 struct sctp_chunk *retval; 3720 3721 retval = sctp_make_reconf(asoc, length); 3722 if (!retval) 3723 return NULL; 3724 3725 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST; 3726 tsnreq.param_hdr.length = htons(length); 3727 tsnreq.request_seq = htonl(asoc->strreset_outseq); 3728 3729 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq); 3730 3731 return retval; 3732 } 3733 3734 /* RE-CONFIG 4.5/4.6 (ADD STREAM) 3735 * 0 1 2 3 3736 * 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 3737 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3738 * | Parameter Type = 17 | Parameter Length = 12 | 3739 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3740 * | Re-configuration Request Sequence Number | 3741 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3742 * | Number of new streams | Reserved | 3743 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3744 */ 3745 struct sctp_chunk *sctp_make_strreset_addstrm( 3746 const struct sctp_association *asoc, 3747 __u16 out, __u16 in) 3748 { 3749 struct sctp_strreset_addstrm addstrm; 3750 __u16 size = sizeof(addstrm); 3751 struct sctp_chunk *retval; 3752 3753 retval = sctp_make_reconf(asoc, (!!out + !!in) * size); 3754 if (!retval) 3755 return NULL; 3756 3757 if (out) { 3758 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS; 3759 addstrm.param_hdr.length = htons(size); 3760 addstrm.number_of_streams = htons(out); 3761 addstrm.request_seq = htonl(asoc->strreset_outseq); 3762 addstrm.reserved = 0; 3763 3764 sctp_addto_chunk(retval, size, &addstrm); 3765 } 3766 3767 if (in) { 3768 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS; 3769 addstrm.param_hdr.length = htons(size); 3770 addstrm.number_of_streams = htons(in); 3771 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out); 3772 addstrm.reserved = 0; 3773 3774 sctp_addto_chunk(retval, size, &addstrm); 3775 } 3776 3777 return retval; 3778 } 3779 3780 /* RE-CONFIG 4.4 (RESP) 3781 * 0 1 2 3 3782 * 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 3783 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3784 * | Parameter Type = 16 | Parameter Length | 3785 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3786 * | Re-configuration Response Sequence Number | 3787 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3788 * | Result | 3789 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3790 */ 3791 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc, 3792 __u32 result, __u32 sn) 3793 { 3794 struct sctp_strreset_resp resp; 3795 __u16 length = sizeof(resp); 3796 struct sctp_chunk *retval; 3797 3798 retval = sctp_make_reconf(asoc, length); 3799 if (!retval) 3800 return NULL; 3801 3802 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3803 resp.param_hdr.length = htons(length); 3804 resp.response_seq = htonl(sn); 3805 resp.result = htonl(result); 3806 3807 sctp_addto_chunk(retval, sizeof(resp), &resp); 3808 3809 return retval; 3810 } 3811 3812 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP) 3813 * 0 1 2 3 3814 * 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 3815 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3816 * | Parameter Type = 16 | Parameter Length | 3817 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3818 * | Re-configuration Response Sequence Number | 3819 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3820 * | Result | 3821 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3822 * | Sender's Next TSN (optional) | 3823 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3824 * | Receiver's Next TSN (optional) | 3825 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3826 */ 3827 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc, 3828 __u32 result, __u32 sn, 3829 __u32 sender_tsn, 3830 __u32 receiver_tsn) 3831 { 3832 struct sctp_strreset_resptsn tsnresp; 3833 __u16 length = sizeof(tsnresp); 3834 struct sctp_chunk *retval; 3835 3836 retval = sctp_make_reconf(asoc, length); 3837 if (!retval) 3838 return NULL; 3839 3840 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3841 tsnresp.param_hdr.length = htons(length); 3842 3843 tsnresp.response_seq = htonl(sn); 3844 tsnresp.result = htonl(result); 3845 tsnresp.senders_next_tsn = htonl(sender_tsn); 3846 tsnresp.receivers_next_tsn = htonl(receiver_tsn); 3847 3848 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp); 3849 3850 return retval; 3851 } 3852 3853 bool sctp_verify_reconf(const struct sctp_association *asoc, 3854 struct sctp_chunk *chunk, 3855 struct sctp_paramhdr **errp) 3856 { 3857 struct sctp_reconf_chunk *hdr; 3858 union sctp_params param; 3859 __be16 last = 0; 3860 __u16 cnt = 0; 3861 3862 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; 3863 sctp_walk_params(param, hdr, params) { 3864 __u16 length = ntohs(param.p->length); 3865 3866 *errp = param.p; 3867 if (cnt++ > 2) 3868 return false; 3869 switch (param.p->type) { 3870 case SCTP_PARAM_RESET_OUT_REQUEST: 3871 if (length < sizeof(struct sctp_strreset_outreq) || 3872 (last && last != SCTP_PARAM_RESET_RESPONSE && 3873 last != SCTP_PARAM_RESET_IN_REQUEST)) 3874 return false; 3875 break; 3876 case SCTP_PARAM_RESET_IN_REQUEST: 3877 if (length < sizeof(struct sctp_strreset_inreq) || 3878 (last && last != SCTP_PARAM_RESET_OUT_REQUEST)) 3879 return false; 3880 break; 3881 case SCTP_PARAM_RESET_RESPONSE: 3882 if ((length != sizeof(struct sctp_strreset_resp) && 3883 length != sizeof(struct sctp_strreset_resptsn)) || 3884 (last && last != SCTP_PARAM_RESET_RESPONSE && 3885 last != SCTP_PARAM_RESET_OUT_REQUEST)) 3886 return false; 3887 break; 3888 case SCTP_PARAM_RESET_TSN_REQUEST: 3889 if (length != 3890 sizeof(struct sctp_strreset_tsnreq) || last) 3891 return false; 3892 break; 3893 case SCTP_PARAM_RESET_ADD_IN_STREAMS: 3894 if (length != sizeof(struct sctp_strreset_addstrm) || 3895 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS)) 3896 return false; 3897 break; 3898 case SCTP_PARAM_RESET_ADD_OUT_STREAMS: 3899 if (length != sizeof(struct sctp_strreset_addstrm) || 3900 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS)) 3901 return false; 3902 break; 3903 default: 3904 return false; 3905 } 3906 3907 last = param.p->type; 3908 } 3909 3910 return true; 3911 } 3912