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 sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, 73 const struct sctp_association *asoc, 74 const struct sctp_chunk *init_chunk, 75 int *cookie_len, 76 const __u8 *raw_addrs, int addrs_len); 77 static int sctp_process_param(struct sctp_association *asoc, 78 union sctp_params param, 79 const union sctp_addr *peer_addr, 80 gfp_t gfp); 81 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 82 const void *data); 83 static void *sctp_addto_chunk_fixed(struct sctp_chunk *, int len, 84 const void *data); 85 86 /* Control chunk destructor */ 87 static void sctp_control_release_owner(struct sk_buff *skb) 88 { 89 /*TODO: do memory release */ 90 } 91 92 static void sctp_control_set_owner_w(struct sctp_chunk *chunk) 93 { 94 struct sctp_association *asoc = chunk->asoc; 95 struct sk_buff *skb = chunk->skb; 96 97 /* TODO: properly account for control chunks. 98 * To do it right we'll need: 99 * 1) endpoint if association isn't known. 100 * 2) proper memory accounting. 101 * 102 * For now don't do anything for now. 103 */ 104 skb->sk = asoc ? asoc->base.sk : NULL; 105 skb->destructor = sctp_control_release_owner; 106 } 107 108 /* What was the inbound interface for this chunk? */ 109 int sctp_chunk_iif(const struct sctp_chunk *chunk) 110 { 111 struct sk_buff *skb = chunk->skb; 112 113 return SCTP_INPUT_CB(skb)->af->skb_iif(skb); 114 } 115 116 /* RFC 2960 3.3.2 Initiation (INIT) (1) 117 * 118 * Note 2: The ECN capable field is reserved for future use of 119 * Explicit Congestion Notification. 120 */ 121 static const struct sctp_paramhdr ecap_param = { 122 SCTP_PARAM_ECN_CAPABLE, 123 cpu_to_be16(sizeof(struct sctp_paramhdr)), 124 }; 125 static const struct sctp_paramhdr prsctp_param = { 126 SCTP_PARAM_FWD_TSN_SUPPORT, 127 cpu_to_be16(sizeof(struct sctp_paramhdr)), 128 }; 129 130 /* A helper to initialize an op error inside a 131 * provided chunk, as most cause codes will be embedded inside an 132 * abort chunk. 133 */ 134 void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, 135 size_t paylen) 136 { 137 sctp_errhdr_t err; 138 __u16 len; 139 140 /* Cause code constants are now defined in network order. */ 141 err.cause = cause_code; 142 len = sizeof(sctp_errhdr_t) + paylen; 143 err.length = htons(len); 144 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err); 145 } 146 147 /* A helper to initialize an op error inside a 148 * provided chunk, as most cause codes will be embedded inside an 149 * abort chunk. Differs from sctp_init_cause in that it won't oops 150 * if there isn't enough space in the op error chunk 151 */ 152 static int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code, 153 size_t paylen) 154 { 155 sctp_errhdr_t err; 156 __u16 len; 157 158 /* Cause code constants are now defined in network order. */ 159 err.cause = cause_code; 160 len = sizeof(sctp_errhdr_t) + paylen; 161 err.length = htons(len); 162 163 if (skb_tailroom(chunk->skb) < len) 164 return -ENOSPC; 165 chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk, 166 sizeof(sctp_errhdr_t), 167 &err); 168 return 0; 169 } 170 /* 3.3.2 Initiation (INIT) (1) 171 * 172 * This chunk is used to initiate a SCTP association between two 173 * endpoints. The format of the INIT chunk is shown below: 174 * 175 * 0 1 2 3 176 * 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 1 177 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 178 * | Type = 1 | Chunk Flags | Chunk Length | 179 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 180 * | Initiate Tag | 181 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 182 * | Advertised Receiver Window Credit (a_rwnd) | 183 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 184 * | Number of Outbound Streams | Number of Inbound Streams | 185 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 186 * | Initial TSN | 187 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 188 * \ \ 189 * / Optional/Variable-Length Parameters / 190 * \ \ 191 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 192 * 193 * 194 * The INIT chunk contains the following parameters. Unless otherwise 195 * noted, each parameter MUST only be included once in the INIT chunk. 196 * 197 * Fixed Parameters Status 198 * ---------------------------------------------- 199 * Initiate Tag Mandatory 200 * Advertised Receiver Window Credit Mandatory 201 * Number of Outbound Streams Mandatory 202 * Number of Inbound Streams Mandatory 203 * Initial TSN Mandatory 204 * 205 * Variable Parameters Status Type Value 206 * ------------------------------------------------------------- 207 * IPv4 Address (Note 1) Optional 5 208 * IPv6 Address (Note 1) Optional 6 209 * Cookie Preservative Optional 9 210 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000) 211 * Host Name Address (Note 3) Optional 11 212 * Supported Address Types (Note 4) Optional 12 213 */ 214 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc, 215 const struct sctp_bind_addr *bp, 216 gfp_t gfp, int vparam_len) 217 { 218 struct net *net = sock_net(asoc->base.sk); 219 struct sctp_endpoint *ep = asoc->ep; 220 sctp_inithdr_t init; 221 union sctp_params addrs; 222 size_t chunksize; 223 struct sctp_chunk *retval = NULL; 224 int num_types, addrs_len = 0; 225 struct sctp_sock *sp; 226 sctp_supported_addrs_param_t sat; 227 __be16 types[2]; 228 sctp_adaptation_ind_param_t aiparam; 229 sctp_supported_ext_param_t ext_param; 230 int num_ext = 0; 231 __u8 extensions[3]; 232 sctp_paramhdr_t *auth_chunks = NULL, 233 *auth_hmacs = NULL; 234 235 /* RFC 2960 3.3.2 Initiation (INIT) (1) 236 * 237 * Note 1: The INIT chunks can contain multiple addresses that 238 * can be IPv4 and/or IPv6 in any combination. 239 */ 240 retval = NULL; 241 242 /* Convert the provided bind address list to raw format. */ 243 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp); 244 245 init.init_tag = htonl(asoc->c.my_vtag); 246 init.a_rwnd = htonl(asoc->rwnd); 247 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 248 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 249 init.initial_tsn = htonl(asoc->c.initial_tsn); 250 251 /* How many address types are needed? */ 252 sp = sctp_sk(asoc->base.sk); 253 num_types = sp->pf->supported_addrs(sp, types); 254 255 chunksize = sizeof(init) + addrs_len; 256 chunksize += SCTP_PAD4(SCTP_SAT_LEN(num_types)); 257 chunksize += sizeof(ecap_param); 258 259 if (asoc->prsctp_enable) 260 chunksize += sizeof(prsctp_param); 261 262 /* ADDIP: Section 4.2.7: 263 * An implementation supporting this extension [ADDIP] MUST list 264 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and 265 * INIT-ACK parameters. 266 */ 267 if (net->sctp.addip_enable) { 268 extensions[num_ext] = SCTP_CID_ASCONF; 269 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 270 num_ext += 2; 271 } 272 273 if (asoc->reconf_enable) { 274 extensions[num_ext] = SCTP_CID_RECONF; 275 num_ext += 1; 276 } 277 278 if (sp->adaptation_ind) 279 chunksize += sizeof(aiparam); 280 281 chunksize += vparam_len; 282 283 /* Account for AUTH related parameters */ 284 if (ep->auth_enable) { 285 /* Add random parameter length*/ 286 chunksize += sizeof(asoc->c.auth_random); 287 288 /* Add HMACS parameter length if any were defined */ 289 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs; 290 if (auth_hmacs->length) 291 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 292 else 293 auth_hmacs = NULL; 294 295 /* Add CHUNKS parameter length */ 296 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks; 297 if (auth_chunks->length) 298 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 299 else 300 auth_chunks = NULL; 301 302 extensions[num_ext] = SCTP_CID_AUTH; 303 num_ext += 1; 304 } 305 306 /* If we have any extensions to report, account for that */ 307 if (num_ext) 308 chunksize += SCTP_PAD4(sizeof(sctp_supported_ext_param_t) + 309 num_ext); 310 311 /* RFC 2960 3.3.2 Initiation (INIT) (1) 312 * 313 * Note 3: An INIT chunk MUST NOT contain more than one Host 314 * Name address parameter. Moreover, the sender of the INIT 315 * MUST NOT combine any other address types with the Host Name 316 * address in the INIT. The receiver of INIT MUST ignore any 317 * other address types if the Host Name address parameter is 318 * present in the received INIT chunk. 319 * 320 * PLEASE DO NOT FIXME [This version does not support Host Name.] 321 */ 322 323 retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp); 324 if (!retval) 325 goto nodata; 326 327 retval->subh.init_hdr = 328 sctp_addto_chunk(retval, sizeof(init), &init); 329 retval->param_hdr.v = 330 sctp_addto_chunk(retval, addrs_len, addrs.v); 331 332 /* RFC 2960 3.3.2 Initiation (INIT) (1) 333 * 334 * Note 4: This parameter, when present, specifies all the 335 * address types the sending endpoint can support. The absence 336 * of this parameter indicates that the sending endpoint can 337 * support any address type. 338 */ 339 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES; 340 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types)); 341 sctp_addto_chunk(retval, sizeof(sat), &sat); 342 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types); 343 344 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 345 346 /* Add the supported extensions parameter. Be nice and add this 347 * fist before addiding the parameters for the extensions themselves 348 */ 349 if (num_ext) { 350 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 351 ext_param.param_hdr.length = 352 htons(sizeof(sctp_supported_ext_param_t) + num_ext); 353 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t), 354 &ext_param); 355 sctp_addto_param(retval, num_ext, extensions); 356 } 357 358 if (asoc->prsctp_enable) 359 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 360 361 if (sp->adaptation_ind) { 362 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 363 aiparam.param_hdr.length = htons(sizeof(aiparam)); 364 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 365 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 366 } 367 368 /* Add SCTP-AUTH chunks to the parameter list */ 369 if (ep->auth_enable) { 370 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random), 371 asoc->c.auth_random); 372 if (auth_hmacs) 373 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 374 auth_hmacs); 375 if (auth_chunks) 376 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 377 auth_chunks); 378 } 379 nodata: 380 kfree(addrs.v); 381 return retval; 382 } 383 384 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, 385 const struct sctp_chunk *chunk, 386 gfp_t gfp, int unkparam_len) 387 { 388 sctp_inithdr_t initack; 389 struct sctp_chunk *retval; 390 union sctp_params addrs; 391 struct sctp_sock *sp; 392 int addrs_len; 393 sctp_cookie_param_t *cookie; 394 int cookie_len; 395 size_t chunksize; 396 sctp_adaptation_ind_param_t aiparam; 397 sctp_supported_ext_param_t ext_param; 398 int num_ext = 0; 399 __u8 extensions[3]; 400 sctp_paramhdr_t *auth_chunks = NULL, 401 *auth_hmacs = NULL, 402 *auth_random = NULL; 403 404 retval = NULL; 405 406 /* Note: there may be no addresses to embed. */ 407 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp); 408 409 initack.init_tag = htonl(asoc->c.my_vtag); 410 initack.a_rwnd = htonl(asoc->rwnd); 411 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 412 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 413 initack.initial_tsn = htonl(asoc->c.initial_tsn); 414 415 /* FIXME: We really ought to build the cookie right 416 * into the packet instead of allocating more fresh memory. 417 */ 418 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len, 419 addrs.v, addrs_len); 420 if (!cookie) 421 goto nomem_cookie; 422 423 /* Calculate the total size of allocation, include the reserved 424 * space for reporting unknown parameters if it is specified. 425 */ 426 sp = sctp_sk(asoc->base.sk); 427 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len; 428 429 /* Tell peer that we'll do ECN only if peer advertised such cap. */ 430 if (asoc->peer.ecn_capable) 431 chunksize += sizeof(ecap_param); 432 433 if (asoc->peer.prsctp_capable) 434 chunksize += sizeof(prsctp_param); 435 436 if (asoc->peer.asconf_capable) { 437 extensions[num_ext] = SCTP_CID_ASCONF; 438 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 439 num_ext += 2; 440 } 441 442 if (asoc->peer.reconf_capable) { 443 extensions[num_ext] = SCTP_CID_RECONF; 444 num_ext += 1; 445 } 446 447 if (sp->adaptation_ind) 448 chunksize += sizeof(aiparam); 449 450 if (asoc->peer.auth_capable) { 451 auth_random = (sctp_paramhdr_t *)asoc->c.auth_random; 452 chunksize += ntohs(auth_random->length); 453 454 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs; 455 if (auth_hmacs->length) 456 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 457 else 458 auth_hmacs = NULL; 459 460 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks; 461 if (auth_chunks->length) 462 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 463 else 464 auth_chunks = NULL; 465 466 extensions[num_ext] = SCTP_CID_AUTH; 467 num_ext += 1; 468 } 469 470 if (num_ext) 471 chunksize += SCTP_PAD4(sizeof(sctp_supported_ext_param_t) + 472 num_ext); 473 474 /* Now allocate and fill out the chunk. */ 475 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp); 476 if (!retval) 477 goto nomem_chunk; 478 479 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 480 * 481 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 482 * HEARTBEAT ACK, * etc.) to the same destination transport 483 * address from which it received the DATA or control chunk 484 * to which it is replying. 485 * 486 * [INIT ACK back to where the INIT came from.] 487 */ 488 retval->transport = chunk->transport; 489 490 retval->subh.init_hdr = 491 sctp_addto_chunk(retval, sizeof(initack), &initack); 492 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); 493 sctp_addto_chunk(retval, cookie_len, cookie); 494 if (asoc->peer.ecn_capable) 495 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 496 if (num_ext) { 497 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 498 ext_param.param_hdr.length = 499 htons(sizeof(sctp_supported_ext_param_t) + num_ext); 500 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t), 501 &ext_param); 502 sctp_addto_param(retval, num_ext, extensions); 503 } 504 if (asoc->peer.prsctp_capable) 505 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 506 507 if (sp->adaptation_ind) { 508 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 509 aiparam.param_hdr.length = htons(sizeof(aiparam)); 510 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 511 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 512 } 513 514 if (asoc->peer.auth_capable) { 515 sctp_addto_chunk(retval, ntohs(auth_random->length), 516 auth_random); 517 if (auth_hmacs) 518 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 519 auth_hmacs); 520 if (auth_chunks) 521 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 522 auth_chunks); 523 } 524 525 /* We need to remove the const qualifier at this point. */ 526 retval->asoc = (struct sctp_association *) asoc; 527 528 nomem_chunk: 529 kfree(cookie); 530 nomem_cookie: 531 kfree(addrs.v); 532 return retval; 533 } 534 535 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10): 536 * 537 * This chunk is used only during the initialization of an association. 538 * It is sent by the initiator of an association to its peer to complete 539 * the initialization process. This chunk MUST precede any DATA chunk 540 * sent within the association, but MAY be bundled with one or more DATA 541 * chunks in the same packet. 542 * 543 * 0 1 2 3 544 * 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 1 545 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 546 * | Type = 10 |Chunk Flags | Length | 547 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 548 * / Cookie / 549 * \ \ 550 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 551 * 552 * Chunk Flags: 8 bit 553 * 554 * Set to zero on transmit and ignored on receipt. 555 * 556 * Length: 16 bits (unsigned integer) 557 * 558 * Set to the size of the chunk in bytes, including the 4 bytes of 559 * the chunk header and the size of the Cookie. 560 * 561 * Cookie: variable size 562 * 563 * This field must contain the exact cookie received in the 564 * State Cookie parameter from the previous INIT ACK. 565 * 566 * An implementation SHOULD make the cookie as small as possible 567 * to insure interoperability. 568 */ 569 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, 570 const struct sctp_chunk *chunk) 571 { 572 struct sctp_chunk *retval; 573 void *cookie; 574 int cookie_len; 575 576 cookie = asoc->peer.cookie; 577 cookie_len = asoc->peer.cookie_len; 578 579 /* Build a cookie echo chunk. */ 580 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0, 581 cookie_len, GFP_ATOMIC); 582 if (!retval) 583 goto nodata; 584 retval->subh.cookie_hdr = 585 sctp_addto_chunk(retval, cookie_len, cookie); 586 587 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 588 * 589 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 590 * HEARTBEAT ACK, * etc.) to the same destination transport 591 * address from which it * received the DATA or control chunk 592 * to which it is replying. 593 * 594 * [COOKIE ECHO back to where the INIT ACK came from.] 595 */ 596 if (chunk) 597 retval->transport = chunk->transport; 598 599 nodata: 600 return retval; 601 } 602 603 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11): 604 * 605 * This chunk is used only during the initialization of an 606 * association. It is used to acknowledge the receipt of a COOKIE 607 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent 608 * within the association, but MAY be bundled with one or more DATA 609 * chunks or SACK chunk in the same SCTP packet. 610 * 611 * 0 1 2 3 612 * 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 1 613 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 614 * | Type = 11 |Chunk Flags | Length = 4 | 615 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 616 * 617 * Chunk Flags: 8 bits 618 * 619 * Set to zero on transmit and ignored on receipt. 620 */ 621 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, 622 const struct sctp_chunk *chunk) 623 { 624 struct sctp_chunk *retval; 625 626 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC); 627 628 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 629 * 630 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 631 * HEARTBEAT ACK, * etc.) to the same destination transport 632 * address from which it * received the DATA or control chunk 633 * to which it is replying. 634 * 635 * [COOKIE ACK back to where the COOKIE ECHO came from.] 636 */ 637 if (retval && chunk) 638 retval->transport = chunk->transport; 639 640 return retval; 641 } 642 643 /* 644 * Appendix A: Explicit Congestion Notification: 645 * CWR: 646 * 647 * RFC 2481 details a specific bit for a sender to send in the header of 648 * its next outbound TCP segment to indicate to its peer that it has 649 * reduced its congestion window. This is termed the CWR bit. For 650 * SCTP the same indication is made by including the CWR chunk. 651 * This chunk contains one data element, i.e. the TSN number that 652 * was sent in the ECNE chunk. This element represents the lowest 653 * TSN number in the datagram that was originally marked with the 654 * CE bit. 655 * 656 * 0 1 2 3 657 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 658 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 659 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 | 660 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 661 * | Lowest TSN Number | 662 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 663 * 664 * Note: The CWR is considered a Control chunk. 665 */ 666 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, 667 const __u32 lowest_tsn, 668 const struct sctp_chunk *chunk) 669 { 670 struct sctp_chunk *retval; 671 sctp_cwrhdr_t cwr; 672 673 cwr.lowest_tsn = htonl(lowest_tsn); 674 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0, 675 sizeof(sctp_cwrhdr_t), GFP_ATOMIC); 676 677 if (!retval) 678 goto nodata; 679 680 retval->subh.ecn_cwr_hdr = 681 sctp_addto_chunk(retval, sizeof(cwr), &cwr); 682 683 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 684 * 685 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 686 * HEARTBEAT ACK, * etc.) to the same destination transport 687 * address from which it * received the DATA or control chunk 688 * to which it is replying. 689 * 690 * [Report a reduced congestion window back to where the ECNE 691 * came from.] 692 */ 693 if (chunk) 694 retval->transport = chunk->transport; 695 696 nodata: 697 return retval; 698 } 699 700 /* Make an ECNE chunk. This is a congestion experienced report. */ 701 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, 702 const __u32 lowest_tsn) 703 { 704 struct sctp_chunk *retval; 705 sctp_ecnehdr_t ecne; 706 707 ecne.lowest_tsn = htonl(lowest_tsn); 708 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0, 709 sizeof(sctp_ecnehdr_t), GFP_ATOMIC); 710 if (!retval) 711 goto nodata; 712 retval->subh.ecne_hdr = 713 sctp_addto_chunk(retval, sizeof(ecne), &ecne); 714 715 nodata: 716 return retval; 717 } 718 719 /* Make a DATA chunk for the given association from the provided 720 * parameters. However, do not populate the data payload. 721 */ 722 struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc, 723 const struct sctp_sndrcvinfo *sinfo, 724 int data_len, __u8 flags, __u16 ssn, 725 gfp_t gfp) 726 { 727 struct sctp_chunk *retval; 728 struct sctp_datahdr dp; 729 int chunk_len; 730 731 /* We assign the TSN as LATE as possible, not here when 732 * creating the chunk. 733 */ 734 dp.tsn = 0; 735 dp.stream = htons(sinfo->sinfo_stream); 736 dp.ppid = sinfo->sinfo_ppid; 737 738 /* Set the flags for an unordered send. */ 739 if (sinfo->sinfo_flags & SCTP_UNORDERED) { 740 flags |= SCTP_DATA_UNORDERED; 741 dp.ssn = 0; 742 } else 743 dp.ssn = htons(ssn); 744 745 chunk_len = sizeof(dp) + data_len; 746 retval = sctp_make_data(asoc, flags, chunk_len, gfp); 747 if (!retval) 748 goto nodata; 749 750 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp); 751 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo)); 752 753 nodata: 754 return retval; 755 } 756 757 /* Create a selective ackowledgement (SACK) for the given 758 * association. This reports on which TSN's we've seen to date, 759 * including duplicates and gaps. 760 */ 761 struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc) 762 { 763 struct sctp_chunk *retval; 764 struct sctp_sackhdr sack; 765 int len; 766 __u32 ctsn; 767 __u16 num_gabs, num_dup_tsns; 768 struct sctp_association *aptr = (struct sctp_association *)asoc; 769 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; 770 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; 771 struct sctp_transport *trans; 772 773 memset(gabs, 0, sizeof(gabs)); 774 ctsn = sctp_tsnmap_get_ctsn(map); 775 776 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn); 777 778 /* How much room is needed in the chunk? */ 779 num_gabs = sctp_tsnmap_num_gabs(map, gabs); 780 num_dup_tsns = sctp_tsnmap_num_dups(map); 781 782 /* Initialize the SACK header. */ 783 sack.cum_tsn_ack = htonl(ctsn); 784 sack.a_rwnd = htonl(asoc->a_rwnd); 785 sack.num_gap_ack_blocks = htons(num_gabs); 786 sack.num_dup_tsns = htons(num_dup_tsns); 787 788 len = sizeof(sack) 789 + sizeof(struct sctp_gap_ack_block) * num_gabs 790 + sizeof(__u32) * num_dup_tsns; 791 792 /* Create the chunk. */ 793 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC); 794 if (!retval) 795 goto nodata; 796 797 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 798 * 799 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 800 * HEARTBEAT ACK, etc.) to the same destination transport 801 * address from which it received the DATA or control chunk to 802 * which it is replying. This rule should also be followed if 803 * the endpoint is bundling DATA chunks together with the 804 * reply chunk. 805 * 806 * However, when acknowledging multiple DATA chunks received 807 * in packets from different source addresses in a single 808 * SACK, the SACK chunk may be transmitted to one of the 809 * destination transport addresses from which the DATA or 810 * control chunks being acknowledged were received. 811 * 812 * [BUG: We do not implement the following paragraph. 813 * Perhaps we should remember the last transport we used for a 814 * SACK and avoid that (if possible) if we have seen any 815 * duplicates. --piggy] 816 * 817 * When a receiver of a duplicate DATA chunk sends a SACK to a 818 * multi- homed endpoint it MAY be beneficial to vary the 819 * destination address and not use the source address of the 820 * DATA chunk. The reason being that receiving a duplicate 821 * from a multi-homed endpoint might indicate that the return 822 * path (as specified in the source address of the DATA chunk) 823 * for the SACK is broken. 824 * 825 * [Send to the address from which we last received a DATA chunk.] 826 */ 827 retval->transport = asoc->peer.last_data_from; 828 829 retval->subh.sack_hdr = 830 sctp_addto_chunk(retval, sizeof(sack), &sack); 831 832 /* Add the gap ack block information. */ 833 if (num_gabs) 834 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, 835 gabs); 836 837 /* Add the duplicate TSN information. */ 838 if (num_dup_tsns) { 839 aptr->stats.idupchunks += num_dup_tsns; 840 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, 841 sctp_tsnmap_get_dups(map)); 842 } 843 /* Once we have a sack generated, check to see what our sack 844 * generation is, if its 0, reset the transports to 0, and reset 845 * the association generation to 1 846 * 847 * The idea is that zero is never used as a valid generation for the 848 * association so no transport will match after a wrap event like this, 849 * Until the next sack 850 */ 851 if (++aptr->peer.sack_generation == 0) { 852 list_for_each_entry(trans, &asoc->peer.transport_addr_list, 853 transports) 854 trans->sack_generation = 0; 855 aptr->peer.sack_generation = 1; 856 } 857 nodata: 858 return retval; 859 } 860 861 /* Make a SHUTDOWN chunk. */ 862 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 863 const struct sctp_chunk *chunk) 864 { 865 struct sctp_chunk *retval; 866 sctp_shutdownhdr_t shut; 867 __u32 ctsn; 868 869 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 870 shut.cum_tsn_ack = htonl(ctsn); 871 872 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0, 873 sizeof(sctp_shutdownhdr_t), GFP_ATOMIC); 874 if (!retval) 875 goto nodata; 876 877 retval->subh.shutdown_hdr = 878 sctp_addto_chunk(retval, sizeof(shut), &shut); 879 880 if (chunk) 881 retval->transport = chunk->transport; 882 nodata: 883 return retval; 884 } 885 886 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 887 const struct sctp_chunk *chunk) 888 { 889 struct sctp_chunk *retval; 890 891 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0, 892 GFP_ATOMIC); 893 894 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 895 * 896 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 897 * HEARTBEAT ACK, * etc.) to the same destination transport 898 * address from which it * received the DATA or control chunk 899 * to which it is replying. 900 * 901 * [ACK back to where the SHUTDOWN came from.] 902 */ 903 if (retval && chunk) 904 retval->transport = chunk->transport; 905 906 return retval; 907 } 908 909 struct sctp_chunk *sctp_make_shutdown_complete( 910 const struct sctp_association *asoc, 911 const struct sctp_chunk *chunk) 912 { 913 struct sctp_chunk *retval; 914 __u8 flags = 0; 915 916 /* Set the T-bit if we have no association (vtag will be 917 * reflected) 918 */ 919 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; 920 921 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 922 0, GFP_ATOMIC); 923 924 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 925 * 926 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 927 * HEARTBEAT ACK, * etc.) to the same destination transport 928 * address from which it * received the DATA or control chunk 929 * to which it is replying. 930 * 931 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK 932 * came from.] 933 */ 934 if (retval && chunk) 935 retval->transport = chunk->transport; 936 937 return retval; 938 } 939 940 /* Create an ABORT. Note that we set the T bit if we have no 941 * association, except when responding to an INIT (sctpimpguide 2.41). 942 */ 943 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 944 const struct sctp_chunk *chunk, 945 const size_t hint) 946 { 947 struct sctp_chunk *retval; 948 __u8 flags = 0; 949 950 /* Set the T-bit if we have no association and 'chunk' is not 951 * an INIT (vtag will be reflected). 952 */ 953 if (!asoc) { 954 if (chunk && chunk->chunk_hdr && 955 chunk->chunk_hdr->type == SCTP_CID_INIT) 956 flags = 0; 957 else 958 flags = SCTP_CHUNK_FLAG_T; 959 } 960 961 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint, 962 GFP_ATOMIC); 963 964 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 965 * 966 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 967 * HEARTBEAT ACK, * etc.) to the same destination transport 968 * address from which it * received the DATA or control chunk 969 * to which it is replying. 970 * 971 * [ABORT back to where the offender came from.] 972 */ 973 if (retval && chunk) 974 retval->transport = chunk->transport; 975 976 return retval; 977 } 978 979 /* Helper to create ABORT with a NO_USER_DATA error. */ 980 struct sctp_chunk *sctp_make_abort_no_data( 981 const struct sctp_association *asoc, 982 const struct sctp_chunk *chunk, __u32 tsn) 983 { 984 struct sctp_chunk *retval; 985 __be32 payload; 986 987 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) 988 + sizeof(tsn)); 989 990 if (!retval) 991 goto no_mem; 992 993 /* Put the tsn back into network byte order. */ 994 payload = htonl(tsn); 995 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload)); 996 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload); 997 998 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 999 * 1000 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1001 * HEARTBEAT ACK, * etc.) to the same destination transport 1002 * address from which it * received the DATA or control chunk 1003 * to which it is replying. 1004 * 1005 * [ABORT back to where the offender came from.] 1006 */ 1007 if (chunk) 1008 retval->transport = chunk->transport; 1009 1010 no_mem: 1011 return retval; 1012 } 1013 1014 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ 1015 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 1016 struct msghdr *msg, 1017 size_t paylen) 1018 { 1019 struct sctp_chunk *retval; 1020 void *payload = NULL; 1021 int err; 1022 1023 retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen); 1024 if (!retval) 1025 goto err_chunk; 1026 1027 if (paylen) { 1028 /* Put the msg_iov together into payload. */ 1029 payload = kmalloc(paylen, GFP_KERNEL); 1030 if (!payload) 1031 goto err_payload; 1032 1033 err = memcpy_from_msg(payload, msg, paylen); 1034 if (err < 0) 1035 goto err_copy; 1036 } 1037 1038 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); 1039 sctp_addto_chunk(retval, paylen, payload); 1040 1041 if (paylen) 1042 kfree(payload); 1043 1044 return retval; 1045 1046 err_copy: 1047 kfree(payload); 1048 err_payload: 1049 sctp_chunk_free(retval); 1050 retval = NULL; 1051 err_chunk: 1052 return retval; 1053 } 1054 1055 /* Append bytes to the end of a parameter. Will panic if chunk is not big 1056 * enough. 1057 */ 1058 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 1059 const void *data) 1060 { 1061 void *target; 1062 int chunklen = ntohs(chunk->chunk_hdr->length); 1063 1064 target = skb_put(chunk->skb, len); 1065 1066 if (data) 1067 memcpy(target, data, len); 1068 else 1069 memset(target, 0, len); 1070 1071 /* Adjust the chunk length field. */ 1072 chunk->chunk_hdr->length = htons(chunklen + len); 1073 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1074 1075 return target; 1076 } 1077 1078 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ 1079 struct sctp_chunk *sctp_make_abort_violation( 1080 const struct sctp_association *asoc, 1081 const struct sctp_chunk *chunk, 1082 const __u8 *payload, 1083 const size_t paylen) 1084 { 1085 struct sctp_chunk *retval; 1086 struct sctp_paramhdr phdr; 1087 1088 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen 1089 + sizeof(sctp_paramhdr_t)); 1090 if (!retval) 1091 goto end; 1092 1093 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen 1094 + sizeof(sctp_paramhdr_t)); 1095 1096 phdr.type = htons(chunk->chunk_hdr->type); 1097 phdr.length = chunk->chunk_hdr->length; 1098 sctp_addto_chunk(retval, paylen, payload); 1099 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr); 1100 1101 end: 1102 return retval; 1103 } 1104 1105 struct sctp_chunk *sctp_make_violation_paramlen( 1106 const struct sctp_association *asoc, 1107 const struct sctp_chunk *chunk, 1108 struct sctp_paramhdr *param) 1109 { 1110 struct sctp_chunk *retval; 1111 static const char error[] = "The following parameter had invalid length:"; 1112 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t) + 1113 sizeof(sctp_paramhdr_t); 1114 1115 retval = sctp_make_abort(asoc, chunk, payload_len); 1116 if (!retval) 1117 goto nodata; 1118 1119 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, 1120 sizeof(error) + sizeof(sctp_paramhdr_t)); 1121 sctp_addto_chunk(retval, sizeof(error), error); 1122 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), param); 1123 1124 nodata: 1125 return retval; 1126 } 1127 1128 struct sctp_chunk *sctp_make_violation_max_retrans( 1129 const struct sctp_association *asoc, 1130 const struct sctp_chunk *chunk) 1131 { 1132 struct sctp_chunk *retval; 1133 static const char error[] = "Association exceeded its max_retans count"; 1134 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t); 1135 1136 retval = sctp_make_abort(asoc, chunk, payload_len); 1137 if (!retval) 1138 goto nodata; 1139 1140 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error)); 1141 sctp_addto_chunk(retval, sizeof(error), error); 1142 1143 nodata: 1144 return retval; 1145 } 1146 1147 /* Make a HEARTBEAT chunk. */ 1148 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1149 const struct sctp_transport *transport) 1150 { 1151 struct sctp_chunk *retval; 1152 sctp_sender_hb_info_t hbinfo; 1153 1154 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, 1155 sizeof(hbinfo), GFP_ATOMIC); 1156 1157 if (!retval) 1158 goto nodata; 1159 1160 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; 1161 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t)); 1162 hbinfo.daddr = transport->ipaddr; 1163 hbinfo.sent_at = jiffies; 1164 hbinfo.hb_nonce = transport->hb_nonce; 1165 1166 /* Cast away the 'const', as this is just telling the chunk 1167 * what transport it belongs to. 1168 */ 1169 retval->transport = (struct sctp_transport *) transport; 1170 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo), 1171 &hbinfo); 1172 1173 nodata: 1174 return retval; 1175 } 1176 1177 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1178 const struct sctp_chunk *chunk, 1179 const void *payload, const size_t paylen) 1180 { 1181 struct sctp_chunk *retval; 1182 1183 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen, 1184 GFP_ATOMIC); 1185 if (!retval) 1186 goto nodata; 1187 1188 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1189 1190 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1191 * 1192 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1193 * HEARTBEAT ACK, * etc.) to the same destination transport 1194 * address from which it * received the DATA or control chunk 1195 * to which it is replying. 1196 * 1197 * [HBACK back to where the HEARTBEAT came from.] 1198 */ 1199 if (chunk) 1200 retval->transport = chunk->transport; 1201 1202 nodata: 1203 return retval; 1204 } 1205 1206 /* Create an Operation Error chunk with the specified space reserved. 1207 * This routine can be used for containing multiple causes in the chunk. 1208 */ 1209 static struct sctp_chunk *sctp_make_op_error_space( 1210 const struct sctp_association *asoc, 1211 const struct sctp_chunk *chunk, 1212 size_t size) 1213 { 1214 struct sctp_chunk *retval; 1215 1216 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0, 1217 sizeof(sctp_errhdr_t) + size, GFP_ATOMIC); 1218 if (!retval) 1219 goto nodata; 1220 1221 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1222 * 1223 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1224 * HEARTBEAT ACK, etc.) to the same destination transport 1225 * address from which it received the DATA or control chunk 1226 * to which it is replying. 1227 * 1228 */ 1229 if (chunk) 1230 retval->transport = chunk->transport; 1231 1232 nodata: 1233 return retval; 1234 } 1235 1236 /* Create an Operation Error chunk of a fixed size, 1237 * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) 1238 * This is a helper function to allocate an error chunk for 1239 * for those invalid parameter codes in which we may not want 1240 * to report all the errors, if the incoming chunk is large 1241 */ 1242 static inline struct sctp_chunk *sctp_make_op_error_fixed( 1243 const struct sctp_association *asoc, 1244 const struct sctp_chunk *chunk) 1245 { 1246 size_t size = asoc ? asoc->pathmtu : 0; 1247 1248 if (!size) 1249 size = SCTP_DEFAULT_MAXSEGMENT; 1250 1251 return sctp_make_op_error_space(asoc, chunk, size); 1252 } 1253 1254 /* Create an Operation Error chunk. */ 1255 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1256 const struct sctp_chunk *chunk, 1257 __be16 cause_code, const void *payload, 1258 size_t paylen, size_t reserve_tail) 1259 { 1260 struct sctp_chunk *retval; 1261 1262 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); 1263 if (!retval) 1264 goto nodata; 1265 1266 sctp_init_cause(retval, cause_code, paylen + reserve_tail); 1267 sctp_addto_chunk(retval, paylen, payload); 1268 if (reserve_tail) 1269 sctp_addto_param(retval, reserve_tail, NULL); 1270 1271 nodata: 1272 return retval; 1273 } 1274 1275 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc) 1276 { 1277 struct sctp_chunk *retval; 1278 struct sctp_hmac *hmac_desc; 1279 struct sctp_authhdr auth_hdr; 1280 __u8 *hmac; 1281 1282 /* Get the first hmac that the peer told us to use */ 1283 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1284 if (unlikely(!hmac_desc)) 1285 return NULL; 1286 1287 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0, 1288 hmac_desc->hmac_len + sizeof(sctp_authhdr_t), 1289 GFP_ATOMIC); 1290 if (!retval) 1291 return NULL; 1292 1293 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1294 auth_hdr.shkey_id = htons(asoc->active_key_id); 1295 1296 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t), 1297 &auth_hdr); 1298 1299 hmac = skb_put(retval->skb, hmac_desc->hmac_len); 1300 memset(hmac, 0, hmac_desc->hmac_len); 1301 1302 /* Adjust the chunk header to include the empty MAC */ 1303 retval->chunk_hdr->length = 1304 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1305 retval->chunk_end = skb_tail_pointer(retval->skb); 1306 1307 return retval; 1308 } 1309 1310 1311 /******************************************************************** 1312 * 2nd Level Abstractions 1313 ********************************************************************/ 1314 1315 /* Turn an skb into a chunk. 1316 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1317 * 1318 * sctpimpguide-05.txt Section 2.8.2 1319 * M1) Each time a new DATA chunk is transmitted 1320 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1321 * 'TSN.Missing.Report' count will be used to determine missing chunks 1322 * and when to fast retransmit. 1323 * 1324 */ 1325 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1326 const struct sctp_association *asoc, 1327 struct sock *sk, gfp_t gfp) 1328 { 1329 struct sctp_chunk *retval; 1330 1331 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp); 1332 1333 if (!retval) 1334 goto nodata; 1335 if (!sk) 1336 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb); 1337 1338 INIT_LIST_HEAD(&retval->list); 1339 retval->skb = skb; 1340 retval->asoc = (struct sctp_association *)asoc; 1341 retval->singleton = 1; 1342 1343 retval->fast_retransmit = SCTP_CAN_FRTX; 1344 1345 /* Polish the bead hole. */ 1346 INIT_LIST_HEAD(&retval->transmitted_list); 1347 INIT_LIST_HEAD(&retval->frag_list); 1348 SCTP_DBG_OBJCNT_INC(chunk); 1349 atomic_set(&retval->refcnt, 1); 1350 1351 nodata: 1352 return retval; 1353 } 1354 1355 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1356 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1357 union sctp_addr *dest) 1358 { 1359 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1360 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1361 } 1362 1363 /* Extract the source address from a chunk. */ 1364 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1365 { 1366 /* If we have a known transport, use that. */ 1367 if (chunk->transport) { 1368 return &chunk->transport->ipaddr; 1369 } else { 1370 /* Otherwise, extract it from the IP header. */ 1371 return &chunk->source; 1372 } 1373 } 1374 1375 /* Create a new chunk, setting the type and flags headers from the 1376 * arguments, reserving enough space for a 'paylen' byte payload. 1377 */ 1378 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 1379 __u8 type, __u8 flags, int paylen, 1380 gfp_t gfp) 1381 { 1382 struct sctp_chunk *retval; 1383 sctp_chunkhdr_t *chunk_hdr; 1384 struct sk_buff *skb; 1385 struct sock *sk; 1386 1387 /* No need to allocate LL here, as this is only a chunk. */ 1388 skb = alloc_skb(SCTP_PAD4(sizeof(sctp_chunkhdr_t) + paylen), gfp); 1389 if (!skb) 1390 goto nodata; 1391 1392 /* Make room for the chunk header. */ 1393 chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t)); 1394 chunk_hdr->type = type; 1395 chunk_hdr->flags = flags; 1396 chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t)); 1397 1398 sk = asoc ? asoc->base.sk : NULL; 1399 retval = sctp_chunkify(skb, asoc, sk, gfp); 1400 if (!retval) { 1401 kfree_skb(skb); 1402 goto nodata; 1403 } 1404 1405 retval->chunk_hdr = chunk_hdr; 1406 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr); 1407 1408 /* Determine if the chunk needs to be authenticated */ 1409 if (sctp_auth_send_cid(type, asoc)) 1410 retval->auth = 1; 1411 1412 return retval; 1413 nodata: 1414 return NULL; 1415 } 1416 1417 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 1418 __u8 flags, int paylen, gfp_t gfp) 1419 { 1420 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp); 1421 } 1422 1423 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 1424 __u8 type, __u8 flags, int paylen, 1425 gfp_t gfp) 1426 { 1427 struct sctp_chunk *chunk; 1428 1429 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp); 1430 if (chunk) 1431 sctp_control_set_owner_w(chunk); 1432 1433 return chunk; 1434 } 1435 1436 /* Release the memory occupied by a chunk. */ 1437 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1438 { 1439 BUG_ON(!list_empty(&chunk->list)); 1440 list_del_init(&chunk->transmitted_list); 1441 1442 consume_skb(chunk->skb); 1443 consume_skb(chunk->auth_chunk); 1444 1445 SCTP_DBG_OBJCNT_DEC(chunk); 1446 kmem_cache_free(sctp_chunk_cachep, chunk); 1447 } 1448 1449 /* Possibly, free the chunk. */ 1450 void sctp_chunk_free(struct sctp_chunk *chunk) 1451 { 1452 /* Release our reference on the message tracker. */ 1453 if (chunk->msg) 1454 sctp_datamsg_put(chunk->msg); 1455 1456 sctp_chunk_put(chunk); 1457 } 1458 1459 /* Grab a reference to the chunk. */ 1460 void sctp_chunk_hold(struct sctp_chunk *ch) 1461 { 1462 atomic_inc(&ch->refcnt); 1463 } 1464 1465 /* Release a reference to the chunk. */ 1466 void sctp_chunk_put(struct sctp_chunk *ch) 1467 { 1468 if (atomic_dec_and_test(&ch->refcnt)) 1469 sctp_chunk_destroy(ch); 1470 } 1471 1472 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1473 * enough. 1474 */ 1475 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1476 { 1477 void *target; 1478 void *padding; 1479 int chunklen = ntohs(chunk->chunk_hdr->length); 1480 int padlen = SCTP_PAD4(chunklen) - chunklen; 1481 1482 padding = skb_put(chunk->skb, padlen); 1483 target = skb_put(chunk->skb, len); 1484 1485 memset(padding, 0, padlen); 1486 memcpy(target, data, len); 1487 1488 /* Adjust the chunk length field. */ 1489 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1490 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1491 1492 return target; 1493 } 1494 1495 /* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient 1496 * space in the chunk 1497 */ 1498 static void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk, 1499 int len, const void *data) 1500 { 1501 if (skb_tailroom(chunk->skb) >= len) 1502 return sctp_addto_chunk(chunk, len, data); 1503 else 1504 return NULL; 1505 } 1506 1507 /* Append bytes from user space to the end of a chunk. Will panic if 1508 * chunk is not big enough. 1509 * Returns a kernel err value. 1510 */ 1511 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len, 1512 struct iov_iter *from) 1513 { 1514 void *target; 1515 ssize_t copied; 1516 1517 /* Make room in chunk for data. */ 1518 target = skb_put(chunk->skb, len); 1519 1520 /* Copy data (whole iovec) into chunk */ 1521 copied = copy_from_iter(target, len, from); 1522 if (copied != len) 1523 return -EFAULT; 1524 1525 /* Adjust the chunk length field. */ 1526 chunk->chunk_hdr->length = 1527 htons(ntohs(chunk->chunk_hdr->length) + len); 1528 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1529 1530 return 0; 1531 } 1532 1533 /* Helper function to assign a TSN if needed. This assumes that both 1534 * the data_hdr and association have already been assigned. 1535 */ 1536 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1537 { 1538 struct sctp_datamsg *msg; 1539 struct sctp_chunk *lchunk; 1540 struct sctp_stream *stream; 1541 __u16 ssn; 1542 __u16 sid; 1543 1544 if (chunk->has_ssn) 1545 return; 1546 1547 /* All fragments will be on the same stream */ 1548 sid = ntohs(chunk->subh.data_hdr->stream); 1549 stream = chunk->asoc->stream; 1550 1551 /* Now assign the sequence number to the entire message. 1552 * All fragments must have the same stream sequence number. 1553 */ 1554 msg = chunk->msg; 1555 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1556 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1557 ssn = 0; 1558 } else { 1559 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1560 ssn = sctp_ssn_next(stream, out, sid); 1561 else 1562 ssn = sctp_ssn_peek(stream, out, sid); 1563 } 1564 1565 lchunk->subh.data_hdr->ssn = htons(ssn); 1566 lchunk->has_ssn = 1; 1567 } 1568 } 1569 1570 /* Helper function to assign a TSN if needed. This assumes that both 1571 * the data_hdr and association have already been assigned. 1572 */ 1573 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1574 { 1575 if (!chunk->has_tsn) { 1576 /* This is the last possible instant to 1577 * assign a TSN. 1578 */ 1579 chunk->subh.data_hdr->tsn = 1580 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1581 chunk->has_tsn = 1; 1582 } 1583 } 1584 1585 /* Create a CLOSED association to use with an incoming packet. */ 1586 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1587 struct sctp_chunk *chunk, 1588 gfp_t gfp) 1589 { 1590 struct sctp_association *asoc; 1591 struct sk_buff *skb; 1592 sctp_scope_t scope; 1593 1594 /* Create the bare association. */ 1595 scope = sctp_scope(sctp_source(chunk)); 1596 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1597 if (!asoc) 1598 goto nodata; 1599 asoc->temp = 1; 1600 skb = chunk->skb; 1601 /* Create an entry for the source address of the packet. */ 1602 SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1); 1603 1604 nodata: 1605 return asoc; 1606 } 1607 1608 /* Build a cookie representing asoc. 1609 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1610 */ 1611 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, 1612 const struct sctp_association *asoc, 1613 const struct sctp_chunk *init_chunk, 1614 int *cookie_len, 1615 const __u8 *raw_addrs, int addrs_len) 1616 { 1617 sctp_cookie_param_t *retval; 1618 struct sctp_signed_cookie *cookie; 1619 int headersize, bodysize; 1620 1621 /* Header size is static data prior to the actual cookie, including 1622 * any padding. 1623 */ 1624 headersize = sizeof(sctp_paramhdr_t) + 1625 (sizeof(struct sctp_signed_cookie) - 1626 sizeof(struct sctp_cookie)); 1627 bodysize = sizeof(struct sctp_cookie) 1628 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1629 1630 /* Pad out the cookie to a multiple to make the signature 1631 * functions simpler to write. 1632 */ 1633 if (bodysize % SCTP_COOKIE_MULTIPLE) 1634 bodysize += SCTP_COOKIE_MULTIPLE 1635 - (bodysize % SCTP_COOKIE_MULTIPLE); 1636 *cookie_len = headersize + bodysize; 1637 1638 /* Clear this memory since we are sending this data structure 1639 * out on the network. 1640 */ 1641 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1642 if (!retval) 1643 goto nodata; 1644 1645 cookie = (struct sctp_signed_cookie *) retval->body; 1646 1647 /* Set up the parameter header. */ 1648 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1649 retval->p.length = htons(*cookie_len); 1650 1651 /* Copy the cookie part of the association itself. */ 1652 cookie->c = asoc->c; 1653 /* Save the raw address list length in the cookie. */ 1654 cookie->c.raw_addr_list_len = addrs_len; 1655 1656 /* Remember PR-SCTP capability. */ 1657 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1658 1659 /* Save adaptation indication in the cookie. */ 1660 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1661 1662 /* Set an expiration time for the cookie. */ 1663 cookie->c.expiration = ktime_add(asoc->cookie_life, 1664 ktime_get_real()); 1665 1666 /* Copy the peer's init packet. */ 1667 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr, 1668 ntohs(init_chunk->chunk_hdr->length)); 1669 1670 /* Copy the raw local address list of the association. */ 1671 memcpy((__u8 *)&cookie->c.peer_init[0] + 1672 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1673 1674 if (sctp_sk(ep->base.sk)->hmac) { 1675 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac); 1676 int err; 1677 1678 /* Sign the message. */ 1679 desc->tfm = sctp_sk(ep->base.sk)->hmac; 1680 desc->flags = 0; 1681 1682 err = crypto_shash_setkey(desc->tfm, ep->secret_key, 1683 sizeof(ep->secret_key)) ?: 1684 crypto_shash_digest(desc, (u8 *)&cookie->c, bodysize, 1685 cookie->signature); 1686 shash_desc_zero(desc); 1687 if (err) 1688 goto free_cookie; 1689 } 1690 1691 return retval; 1692 1693 free_cookie: 1694 kfree(retval); 1695 nodata: 1696 *cookie_len = 0; 1697 return NULL; 1698 } 1699 1700 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1701 struct sctp_association *sctp_unpack_cookie( 1702 const struct sctp_endpoint *ep, 1703 const struct sctp_association *asoc, 1704 struct sctp_chunk *chunk, gfp_t gfp, 1705 int *error, struct sctp_chunk **errp) 1706 { 1707 struct sctp_association *retval = NULL; 1708 struct sctp_signed_cookie *cookie; 1709 struct sctp_cookie *bear_cookie; 1710 int headersize, bodysize, fixed_size; 1711 __u8 *digest = ep->digest; 1712 unsigned int len; 1713 sctp_scope_t scope; 1714 struct sk_buff *skb = chunk->skb; 1715 ktime_t kt; 1716 1717 /* Header size is static data prior to the actual cookie, including 1718 * any padding. 1719 */ 1720 headersize = sizeof(sctp_chunkhdr_t) + 1721 (sizeof(struct sctp_signed_cookie) - 1722 sizeof(struct sctp_cookie)); 1723 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1724 fixed_size = headersize + sizeof(struct sctp_cookie); 1725 1726 /* Verify that the chunk looks like it even has a cookie. 1727 * There must be enough room for our cookie and our peer's 1728 * INIT chunk. 1729 */ 1730 len = ntohs(chunk->chunk_hdr->length); 1731 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1732 goto malformed; 1733 1734 /* Verify that the cookie has been padded out. */ 1735 if (bodysize % SCTP_COOKIE_MULTIPLE) 1736 goto malformed; 1737 1738 /* Process the cookie. */ 1739 cookie = chunk->subh.cookie_hdr; 1740 bear_cookie = &cookie->c; 1741 1742 if (!sctp_sk(ep->base.sk)->hmac) 1743 goto no_hmac; 1744 1745 /* Check the signature. */ 1746 { 1747 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac); 1748 int err; 1749 1750 desc->tfm = sctp_sk(ep->base.sk)->hmac; 1751 desc->flags = 0; 1752 1753 err = crypto_shash_setkey(desc->tfm, ep->secret_key, 1754 sizeof(ep->secret_key)) ?: 1755 crypto_shash_digest(desc, (u8 *)bear_cookie, bodysize, 1756 digest); 1757 shash_desc_zero(desc); 1758 1759 if (err) { 1760 *error = -SCTP_IERROR_NOMEM; 1761 goto fail; 1762 } 1763 } 1764 1765 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1766 *error = -SCTP_IERROR_BAD_SIG; 1767 goto fail; 1768 } 1769 1770 no_hmac: 1771 /* IG Section 2.35.2: 1772 * 3) Compare the port numbers and the verification tag contained 1773 * within the COOKIE ECHO chunk to the actual port numbers and the 1774 * verification tag within the SCTP common header of the received 1775 * packet. If these values do not match the packet MUST be silently 1776 * discarded, 1777 */ 1778 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1779 *error = -SCTP_IERROR_BAD_TAG; 1780 goto fail; 1781 } 1782 1783 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1784 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1785 *error = -SCTP_IERROR_BAD_PORTS; 1786 goto fail; 1787 } 1788 1789 /* Check to see if the cookie is stale. If there is already 1790 * an association, there is no need to check cookie's expiration 1791 * for init collision case of lost COOKIE ACK. 1792 * If skb has been timestamped, then use the stamp, otherwise 1793 * use current time. This introduces a small possibility that 1794 * that a cookie may be considered expired, but his would only slow 1795 * down the new association establishment instead of every packet. 1796 */ 1797 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1798 kt = skb_get_ktime(skb); 1799 else 1800 kt = ktime_get_real(); 1801 1802 if (!asoc && ktime_before(bear_cookie->expiration, kt)) { 1803 /* 1804 * Section 3.3.10.3 Stale Cookie Error (3) 1805 * 1806 * Cause of error 1807 * --------------- 1808 * Stale Cookie Error: Indicates the receipt of a valid State 1809 * Cookie that has expired. 1810 */ 1811 len = ntohs(chunk->chunk_hdr->length); 1812 *errp = sctp_make_op_error_space(asoc, chunk, len); 1813 if (*errp) { 1814 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); 1815 __be32 n = htonl(usecs); 1816 1817 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE, 1818 sizeof(n)); 1819 sctp_addto_chunk(*errp, sizeof(n), &n); 1820 *error = -SCTP_IERROR_STALE_COOKIE; 1821 } else 1822 *error = -SCTP_IERROR_NOMEM; 1823 1824 goto fail; 1825 } 1826 1827 /* Make a new base association. */ 1828 scope = sctp_scope(sctp_source(chunk)); 1829 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1830 if (!retval) { 1831 *error = -SCTP_IERROR_NOMEM; 1832 goto fail; 1833 } 1834 1835 /* Set up our peer's port number. */ 1836 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1837 1838 /* Populate the association from the cookie. */ 1839 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1840 1841 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1842 GFP_ATOMIC) < 0) { 1843 *error = -SCTP_IERROR_NOMEM; 1844 goto fail; 1845 } 1846 1847 /* Also, add the destination address. */ 1848 if (list_empty(&retval->base.bind_addr.address_list)) { 1849 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1850 sizeof(chunk->dest), SCTP_ADDR_SRC, 1851 GFP_ATOMIC); 1852 } 1853 1854 retval->next_tsn = retval->c.initial_tsn; 1855 retval->ctsn_ack_point = retval->next_tsn - 1; 1856 retval->addip_serial = retval->c.initial_tsn; 1857 retval->strreset_outseq = retval->c.initial_tsn; 1858 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1859 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1860 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1861 1862 /* The INIT stuff will be done by the side effects. */ 1863 return retval; 1864 1865 fail: 1866 if (retval) 1867 sctp_association_free(retval); 1868 1869 return NULL; 1870 1871 malformed: 1872 /* Yikes! The packet is either corrupt or deliberately 1873 * malformed. 1874 */ 1875 *error = -SCTP_IERROR_MALFORMED; 1876 goto fail; 1877 } 1878 1879 /******************************************************************** 1880 * 3rd Level Abstractions 1881 ********************************************************************/ 1882 1883 struct __sctp_missing { 1884 __be32 num_missing; 1885 __be16 type; 1886 } __packed; 1887 1888 /* 1889 * Report a missing mandatory parameter. 1890 */ 1891 static int sctp_process_missing_param(const struct sctp_association *asoc, 1892 sctp_param_t paramtype, 1893 struct sctp_chunk *chunk, 1894 struct sctp_chunk **errp) 1895 { 1896 struct __sctp_missing report; 1897 __u16 len; 1898 1899 len = SCTP_PAD4(sizeof(report)); 1900 1901 /* Make an ERROR chunk, preparing enough room for 1902 * returning multiple unknown parameters. 1903 */ 1904 if (!*errp) 1905 *errp = sctp_make_op_error_space(asoc, chunk, len); 1906 1907 if (*errp) { 1908 report.num_missing = htonl(1); 1909 report.type = paramtype; 1910 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1911 sizeof(report)); 1912 sctp_addto_chunk(*errp, sizeof(report), &report); 1913 } 1914 1915 /* Stop processing this chunk. */ 1916 return 0; 1917 } 1918 1919 /* Report an Invalid Mandatory Parameter. */ 1920 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1921 struct sctp_chunk *chunk, 1922 struct sctp_chunk **errp) 1923 { 1924 /* Invalid Mandatory Parameter Error has no payload. */ 1925 1926 if (!*errp) 1927 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1928 1929 if (*errp) 1930 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1931 1932 /* Stop processing this chunk. */ 1933 return 0; 1934 } 1935 1936 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1937 struct sctp_paramhdr *param, 1938 const struct sctp_chunk *chunk, 1939 struct sctp_chunk **errp) 1940 { 1941 /* This is a fatal error. Any accumulated non-fatal errors are 1942 * not reported. 1943 */ 1944 if (*errp) 1945 sctp_chunk_free(*errp); 1946 1947 /* Create an error chunk and fill it in with our payload. */ 1948 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1949 1950 return 0; 1951 } 1952 1953 1954 /* Do not attempt to handle the HOST_NAME parm. However, do 1955 * send back an indicator to the peer. 1956 */ 1957 static int sctp_process_hn_param(const struct sctp_association *asoc, 1958 union sctp_params param, 1959 struct sctp_chunk *chunk, 1960 struct sctp_chunk **errp) 1961 { 1962 __u16 len = ntohs(param.p->length); 1963 1964 /* Processing of the HOST_NAME parameter will generate an 1965 * ABORT. If we've accumulated any non-fatal errors, they 1966 * would be unrecognized parameters and we should not include 1967 * them in the ABORT. 1968 */ 1969 if (*errp) 1970 sctp_chunk_free(*errp); 1971 1972 *errp = sctp_make_op_error_space(asoc, chunk, len); 1973 1974 if (*errp) { 1975 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len); 1976 sctp_addto_chunk(*errp, len, param.v); 1977 } 1978 1979 /* Stop processing this chunk. */ 1980 return 0; 1981 } 1982 1983 static int sctp_verify_ext_param(struct net *net, union sctp_params param) 1984 { 1985 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 1986 int have_auth = 0; 1987 int have_asconf = 0; 1988 int i; 1989 1990 for (i = 0; i < num_ext; i++) { 1991 switch (param.ext->chunks[i]) { 1992 case SCTP_CID_AUTH: 1993 have_auth = 1; 1994 break; 1995 case SCTP_CID_ASCONF: 1996 case SCTP_CID_ASCONF_ACK: 1997 have_asconf = 1; 1998 break; 1999 } 2000 } 2001 2002 /* ADD-IP Security: The draft requires us to ABORT or ignore the 2003 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 2004 * only if ADD-IP is turned on and we are not backward-compatible 2005 * mode. 2006 */ 2007 if (net->sctp.addip_noauth) 2008 return 1; 2009 2010 if (net->sctp.addip_enable && !have_auth && have_asconf) 2011 return 0; 2012 2013 return 1; 2014 } 2015 2016 static void sctp_process_ext_param(struct sctp_association *asoc, 2017 union sctp_params param) 2018 { 2019 struct net *net = sock_net(asoc->base.sk); 2020 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2021 int i; 2022 2023 for (i = 0; i < num_ext; i++) { 2024 switch (param.ext->chunks[i]) { 2025 case SCTP_CID_RECONF: 2026 if (asoc->reconf_enable && 2027 !asoc->peer.reconf_capable) 2028 asoc->peer.reconf_capable = 1; 2029 break; 2030 case SCTP_CID_FWD_TSN: 2031 if (asoc->prsctp_enable && !asoc->peer.prsctp_capable) 2032 asoc->peer.prsctp_capable = 1; 2033 break; 2034 case SCTP_CID_AUTH: 2035 /* if the peer reports AUTH, assume that he 2036 * supports AUTH. 2037 */ 2038 if (asoc->ep->auth_enable) 2039 asoc->peer.auth_capable = 1; 2040 break; 2041 case SCTP_CID_ASCONF: 2042 case SCTP_CID_ASCONF_ACK: 2043 if (net->sctp.addip_enable) 2044 asoc->peer.asconf_capable = 1; 2045 break; 2046 default: 2047 break; 2048 } 2049 } 2050 } 2051 2052 /* RFC 3.2.1 & the Implementers Guide 2.2. 2053 * 2054 * The Parameter Types are encoded such that the 2055 * highest-order two bits specify the action that must be 2056 * taken if the processing endpoint does not recognize the 2057 * Parameter Type. 2058 * 2059 * 00 - Stop processing this parameter; do not process any further 2060 * parameters within this chunk 2061 * 2062 * 01 - Stop processing this parameter, do not process any further 2063 * parameters within this chunk, and report the unrecognized 2064 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2065 * 2066 * 10 - Skip this parameter and continue processing. 2067 * 2068 * 11 - Skip this parameter and continue processing but 2069 * report the unrecognized parameter in an 2070 * 'Unrecognized Parameter' ERROR chunk. 2071 * 2072 * Return value: 2073 * SCTP_IERROR_NO_ERROR - continue with the chunk 2074 * SCTP_IERROR_ERROR - stop and report an error. 2075 * SCTP_IERROR_NOMEME - out of memory. 2076 */ 2077 static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc, 2078 union sctp_params param, 2079 struct sctp_chunk *chunk, 2080 struct sctp_chunk **errp) 2081 { 2082 int retval = SCTP_IERROR_NO_ERROR; 2083 2084 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2085 case SCTP_PARAM_ACTION_DISCARD: 2086 retval = SCTP_IERROR_ERROR; 2087 break; 2088 case SCTP_PARAM_ACTION_SKIP: 2089 break; 2090 case SCTP_PARAM_ACTION_DISCARD_ERR: 2091 retval = SCTP_IERROR_ERROR; 2092 /* Fall through */ 2093 case SCTP_PARAM_ACTION_SKIP_ERR: 2094 /* Make an ERROR chunk, preparing enough room for 2095 * returning multiple unknown parameters. 2096 */ 2097 if (NULL == *errp) 2098 *errp = sctp_make_op_error_fixed(asoc, chunk); 2099 2100 if (*errp) { 2101 if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2102 SCTP_PAD4(ntohs(param.p->length)))) 2103 sctp_addto_chunk_fixed(*errp, 2104 SCTP_PAD4(ntohs(param.p->length)), 2105 param.v); 2106 } else { 2107 /* If there is no memory for generating the ERROR 2108 * report as specified, an ABORT will be triggered 2109 * to the peer and the association won't be 2110 * established. 2111 */ 2112 retval = SCTP_IERROR_NOMEM; 2113 } 2114 break; 2115 default: 2116 break; 2117 } 2118 2119 return retval; 2120 } 2121 2122 /* Verify variable length parameters 2123 * Return values: 2124 * SCTP_IERROR_ABORT - trigger an ABORT 2125 * SCTP_IERROR_NOMEM - out of memory (abort) 2126 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2127 * SCTP_IERROR_NO_ERROR - continue with the chunk 2128 */ 2129 static sctp_ierror_t sctp_verify_param(struct net *net, 2130 const struct sctp_endpoint *ep, 2131 const struct sctp_association *asoc, 2132 union sctp_params param, 2133 sctp_cid_t cid, 2134 struct sctp_chunk *chunk, 2135 struct sctp_chunk **err_chunk) 2136 { 2137 struct sctp_hmac_algo_param *hmacs; 2138 int retval = SCTP_IERROR_NO_ERROR; 2139 __u16 n_elt, id = 0; 2140 int i; 2141 2142 /* FIXME - This routine is not looking at each parameter per the 2143 * chunk type, i.e., unrecognized parameters should be further 2144 * identified based on the chunk id. 2145 */ 2146 2147 switch (param.p->type) { 2148 case SCTP_PARAM_IPV4_ADDRESS: 2149 case SCTP_PARAM_IPV6_ADDRESS: 2150 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2151 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2152 case SCTP_PARAM_STATE_COOKIE: 2153 case SCTP_PARAM_HEARTBEAT_INFO: 2154 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2155 case SCTP_PARAM_ECN_CAPABLE: 2156 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2157 break; 2158 2159 case SCTP_PARAM_SUPPORTED_EXT: 2160 if (!sctp_verify_ext_param(net, param)) 2161 return SCTP_IERROR_ABORT; 2162 break; 2163 2164 case SCTP_PARAM_SET_PRIMARY: 2165 if (net->sctp.addip_enable) 2166 break; 2167 goto fallthrough; 2168 2169 case SCTP_PARAM_HOST_NAME_ADDRESS: 2170 /* Tell the peer, we won't support this param. */ 2171 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2172 retval = SCTP_IERROR_ABORT; 2173 break; 2174 2175 case SCTP_PARAM_FWD_TSN_SUPPORT: 2176 if (ep->prsctp_enable) 2177 break; 2178 goto fallthrough; 2179 2180 case SCTP_PARAM_RANDOM: 2181 if (!ep->auth_enable) 2182 goto fallthrough; 2183 2184 /* SCTP-AUTH: Secion 6.1 2185 * If the random number is not 32 byte long the association 2186 * MUST be aborted. The ABORT chunk SHOULD contain the error 2187 * cause 'Protocol Violation'. 2188 */ 2189 if (SCTP_AUTH_RANDOM_LENGTH != 2190 ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) { 2191 sctp_process_inv_paramlength(asoc, param.p, 2192 chunk, err_chunk); 2193 retval = SCTP_IERROR_ABORT; 2194 } 2195 break; 2196 2197 case SCTP_PARAM_CHUNKS: 2198 if (!ep->auth_enable) 2199 goto fallthrough; 2200 2201 /* SCTP-AUTH: Section 3.2 2202 * The CHUNKS parameter MUST be included once in the INIT or 2203 * INIT-ACK chunk if the sender wants to receive authenticated 2204 * chunks. Its maximum length is 260 bytes. 2205 */ 2206 if (260 < ntohs(param.p->length)) { 2207 sctp_process_inv_paramlength(asoc, param.p, 2208 chunk, err_chunk); 2209 retval = SCTP_IERROR_ABORT; 2210 } 2211 break; 2212 2213 case SCTP_PARAM_HMAC_ALGO: 2214 if (!ep->auth_enable) 2215 goto fallthrough; 2216 2217 hmacs = (struct sctp_hmac_algo_param *)param.p; 2218 n_elt = (ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) >> 1; 2219 2220 /* SCTP-AUTH: Section 6.1 2221 * The HMAC algorithm based on SHA-1 MUST be supported and 2222 * included in the HMAC-ALGO parameter. 2223 */ 2224 for (i = 0; i < n_elt; i++) { 2225 id = ntohs(hmacs->hmac_ids[i]); 2226 2227 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2228 break; 2229 } 2230 2231 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2232 sctp_process_inv_paramlength(asoc, param.p, chunk, 2233 err_chunk); 2234 retval = SCTP_IERROR_ABORT; 2235 } 2236 break; 2237 fallthrough: 2238 default: 2239 pr_debug("%s: unrecognized param:%d for chunk:%d\n", 2240 __func__, ntohs(param.p->type), cid); 2241 2242 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2243 break; 2244 } 2245 return retval; 2246 } 2247 2248 /* Verify the INIT packet before we process it. */ 2249 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 2250 const struct sctp_association *asoc, sctp_cid_t cid, 2251 sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk, 2252 struct sctp_chunk **errp) 2253 { 2254 union sctp_params param; 2255 bool has_cookie = false; 2256 int result; 2257 2258 /* Check for missing mandatory parameters. Note: Initial TSN is 2259 * also mandatory, but is not checked here since the valid range 2260 * is 0..2**32-1. RFC4960, section 3.3.3. 2261 */ 2262 if (peer_init->init_hdr.num_outbound_streams == 0 || 2263 peer_init->init_hdr.num_inbound_streams == 0 || 2264 peer_init->init_hdr.init_tag == 0 || 2265 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) 2266 return sctp_process_inv_mandatory(asoc, chunk, errp); 2267 2268 sctp_walk_params(param, peer_init, init_hdr.params) { 2269 if (param.p->type == SCTP_PARAM_STATE_COOKIE) 2270 has_cookie = true; 2271 } 2272 2273 /* There is a possibility that a parameter length was bad and 2274 * in that case we would have stoped walking the parameters. 2275 * The current param.p would point at the bad one. 2276 * Current consensus on the mailing list is to generate a PROTOCOL 2277 * VIOLATION error. We build the ERROR chunk here and let the normal 2278 * error handling code build and send the packet. 2279 */ 2280 if (param.v != (void *)chunk->chunk_end) 2281 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2282 2283 /* The only missing mandatory param possible today is 2284 * the state cookie for an INIT-ACK chunk. 2285 */ 2286 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2287 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2288 chunk, errp); 2289 2290 /* Verify all the variable length parameters */ 2291 sctp_walk_params(param, peer_init, init_hdr.params) { 2292 result = sctp_verify_param(net, ep, asoc, param, cid, 2293 chunk, errp); 2294 switch (result) { 2295 case SCTP_IERROR_ABORT: 2296 case SCTP_IERROR_NOMEM: 2297 return 0; 2298 case SCTP_IERROR_ERROR: 2299 return 1; 2300 case SCTP_IERROR_NO_ERROR: 2301 default: 2302 break; 2303 } 2304 2305 } /* for (loop through all parameters) */ 2306 2307 return 1; 2308 } 2309 2310 /* Unpack the parameters in an INIT packet into an association. 2311 * Returns 0 on failure, else success. 2312 * FIXME: This is an association method. 2313 */ 2314 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2315 const union sctp_addr *peer_addr, 2316 sctp_init_chunk_t *peer_init, gfp_t gfp) 2317 { 2318 struct net *net = sock_net(asoc->base.sk); 2319 union sctp_params param; 2320 struct sctp_transport *transport; 2321 struct list_head *pos, *temp; 2322 struct sctp_af *af; 2323 union sctp_addr addr; 2324 char *cookie; 2325 int src_match = 0; 2326 2327 /* We must include the address that the INIT packet came from. 2328 * This is the only address that matters for an INIT packet. 2329 * When processing a COOKIE ECHO, we retrieve the from address 2330 * of the INIT from the cookie. 2331 */ 2332 2333 /* This implementation defaults to making the first transport 2334 * added as the primary transport. The source address seems to 2335 * be a a better choice than any of the embedded addresses. 2336 */ 2337 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2338 goto nomem; 2339 2340 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2341 src_match = 1; 2342 2343 /* Process the initialization parameters. */ 2344 sctp_walk_params(param, peer_init, init_hdr.params) { 2345 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2346 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2347 af = sctp_get_af_specific(param_type2af(param.p->type)); 2348 af->from_addr_param(&addr, param.addr, 2349 chunk->sctp_hdr->source, 0); 2350 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2351 src_match = 1; 2352 } 2353 2354 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2355 goto clean_up; 2356 } 2357 2358 /* source address of chunk may not match any valid address */ 2359 if (!src_match) 2360 goto clean_up; 2361 2362 /* AUTH: After processing the parameters, make sure that we 2363 * have all the required info to potentially do authentications. 2364 */ 2365 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2366 !asoc->peer.peer_hmacs)) 2367 asoc->peer.auth_capable = 0; 2368 2369 /* In a non-backward compatible mode, if the peer claims 2370 * support for ADD-IP but not AUTH, the ADD-IP spec states 2371 * that we MUST ABORT the association. Section 6. The section 2372 * also give us an option to silently ignore the packet, which 2373 * is what we'll do here. 2374 */ 2375 if (!net->sctp.addip_noauth && 2376 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2377 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2378 SCTP_PARAM_DEL_IP | 2379 SCTP_PARAM_SET_PRIMARY); 2380 asoc->peer.asconf_capable = 0; 2381 goto clean_up; 2382 } 2383 2384 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2385 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2386 transport = list_entry(pos, struct sctp_transport, transports); 2387 if (transport->state == SCTP_UNKNOWN) { 2388 sctp_assoc_rm_peer(asoc, transport); 2389 } 2390 } 2391 2392 /* The fixed INIT headers are always in network byte 2393 * order. 2394 */ 2395 asoc->peer.i.init_tag = 2396 ntohl(peer_init->init_hdr.init_tag); 2397 asoc->peer.i.a_rwnd = 2398 ntohl(peer_init->init_hdr.a_rwnd); 2399 asoc->peer.i.num_outbound_streams = 2400 ntohs(peer_init->init_hdr.num_outbound_streams); 2401 asoc->peer.i.num_inbound_streams = 2402 ntohs(peer_init->init_hdr.num_inbound_streams); 2403 asoc->peer.i.initial_tsn = 2404 ntohl(peer_init->init_hdr.initial_tsn); 2405 2406 asoc->strreset_inseq = asoc->peer.i.initial_tsn; 2407 2408 /* Apply the upper bounds for output streams based on peer's 2409 * number of inbound streams. 2410 */ 2411 if (asoc->c.sinit_num_ostreams > 2412 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2413 asoc->c.sinit_num_ostreams = 2414 ntohs(peer_init->init_hdr.num_inbound_streams); 2415 } 2416 2417 if (asoc->c.sinit_max_instreams > 2418 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2419 asoc->c.sinit_max_instreams = 2420 ntohs(peer_init->init_hdr.num_outbound_streams); 2421 } 2422 2423 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2424 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2425 2426 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2427 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2428 2429 /* Copy cookie in case we need to resend COOKIE-ECHO. */ 2430 cookie = asoc->peer.cookie; 2431 if (cookie) { 2432 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp); 2433 if (!asoc->peer.cookie) 2434 goto clean_up; 2435 } 2436 2437 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2438 * high (for example, implementations MAY use the size of the receiver 2439 * advertised window). 2440 */ 2441 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2442 transports) { 2443 transport->ssthresh = asoc->peer.i.a_rwnd; 2444 } 2445 2446 /* Set up the TSN tracking pieces. */ 2447 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2448 asoc->peer.i.initial_tsn, gfp)) 2449 goto clean_up; 2450 2451 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2452 * 2453 * The stream sequence number in all the streams shall start 2454 * from 0 when the association is established. Also, when the 2455 * stream sequence number reaches the value 65535 the next 2456 * stream sequence number shall be set to 0. 2457 */ 2458 2459 /* Allocate storage for the negotiated streams if it is not a temporary 2460 * association. 2461 */ 2462 if (!asoc->temp) { 2463 int error; 2464 2465 asoc->stream = sctp_stream_new(asoc->c.sinit_max_instreams, 2466 asoc->c.sinit_num_ostreams, gfp); 2467 if (!asoc->stream) 2468 goto clean_up; 2469 2470 error = sctp_assoc_set_id(asoc, gfp); 2471 if (error) 2472 goto clean_up; 2473 } 2474 2475 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2476 * 2477 * When an endpoint has an ASCONF signaled change to be sent to the 2478 * remote endpoint it should do the following: 2479 * ... 2480 * A2) A serial number should be assigned to the Chunk. The serial 2481 * number should be a monotonically increasing number. All serial 2482 * numbers are defined to be initialized at the start of the 2483 * association to the same value as the Initial TSN. 2484 */ 2485 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2486 return 1; 2487 2488 clean_up: 2489 /* Release the transport structures. */ 2490 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2491 transport = list_entry(pos, struct sctp_transport, transports); 2492 if (transport->state != SCTP_ACTIVE) 2493 sctp_assoc_rm_peer(asoc, transport); 2494 } 2495 2496 nomem: 2497 return 0; 2498 } 2499 2500 2501 /* Update asoc with the option described in param. 2502 * 2503 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2504 * 2505 * asoc is the association to update. 2506 * param is the variable length parameter to use for update. 2507 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2508 * If the current packet is an INIT we want to minimize the amount of 2509 * work we do. In particular, we should not build transport 2510 * structures for the addresses. 2511 */ 2512 static int sctp_process_param(struct sctp_association *asoc, 2513 union sctp_params param, 2514 const union sctp_addr *peer_addr, 2515 gfp_t gfp) 2516 { 2517 struct net *net = sock_net(asoc->base.sk); 2518 union sctp_addr addr; 2519 int i; 2520 __u16 sat; 2521 int retval = 1; 2522 sctp_scope_t scope; 2523 u32 stale; 2524 struct sctp_af *af; 2525 union sctp_addr_param *addr_param; 2526 struct sctp_transport *t; 2527 struct sctp_endpoint *ep = asoc->ep; 2528 2529 /* We maintain all INIT parameters in network byte order all the 2530 * time. This allows us to not worry about whether the parameters 2531 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2532 */ 2533 switch (param.p->type) { 2534 case SCTP_PARAM_IPV6_ADDRESS: 2535 if (PF_INET6 != asoc->base.sk->sk_family) 2536 break; 2537 goto do_addr_param; 2538 2539 case SCTP_PARAM_IPV4_ADDRESS: 2540 /* v4 addresses are not allowed on v6-only socket */ 2541 if (ipv6_only_sock(asoc->base.sk)) 2542 break; 2543 do_addr_param: 2544 af = sctp_get_af_specific(param_type2af(param.p->type)); 2545 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); 2546 scope = sctp_scope(peer_addr); 2547 if (sctp_in_scope(net, &addr, scope)) 2548 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2549 return 0; 2550 break; 2551 2552 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2553 if (!net->sctp.cookie_preserve_enable) 2554 break; 2555 2556 stale = ntohl(param.life->lifespan_increment); 2557 2558 /* Suggested Cookie Life span increment's unit is msec, 2559 * (1/1000sec). 2560 */ 2561 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale); 2562 break; 2563 2564 case SCTP_PARAM_HOST_NAME_ADDRESS: 2565 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__); 2566 break; 2567 2568 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2569 /* Turn off the default values first so we'll know which 2570 * ones are really set by the peer. 2571 */ 2572 asoc->peer.ipv4_address = 0; 2573 asoc->peer.ipv6_address = 0; 2574 2575 /* Assume that peer supports the address family 2576 * by which it sends a packet. 2577 */ 2578 if (peer_addr->sa.sa_family == AF_INET6) 2579 asoc->peer.ipv6_address = 1; 2580 else if (peer_addr->sa.sa_family == AF_INET) 2581 asoc->peer.ipv4_address = 1; 2582 2583 /* Cycle through address types; avoid divide by 0. */ 2584 sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2585 if (sat) 2586 sat /= sizeof(__u16); 2587 2588 for (i = 0; i < sat; ++i) { 2589 switch (param.sat->types[i]) { 2590 case SCTP_PARAM_IPV4_ADDRESS: 2591 asoc->peer.ipv4_address = 1; 2592 break; 2593 2594 case SCTP_PARAM_IPV6_ADDRESS: 2595 if (PF_INET6 == asoc->base.sk->sk_family) 2596 asoc->peer.ipv6_address = 1; 2597 break; 2598 2599 case SCTP_PARAM_HOST_NAME_ADDRESS: 2600 asoc->peer.hostname_address = 1; 2601 break; 2602 2603 default: /* Just ignore anything else. */ 2604 break; 2605 } 2606 } 2607 break; 2608 2609 case SCTP_PARAM_STATE_COOKIE: 2610 asoc->peer.cookie_len = 2611 ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2612 asoc->peer.cookie = param.cookie->body; 2613 break; 2614 2615 case SCTP_PARAM_HEARTBEAT_INFO: 2616 /* Would be odd to receive, but it causes no problems. */ 2617 break; 2618 2619 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2620 /* Rejected during verify stage. */ 2621 break; 2622 2623 case SCTP_PARAM_ECN_CAPABLE: 2624 asoc->peer.ecn_capable = 1; 2625 break; 2626 2627 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2628 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2629 break; 2630 2631 case SCTP_PARAM_SET_PRIMARY: 2632 if (!net->sctp.addip_enable) 2633 goto fall_through; 2634 2635 addr_param = param.v + sizeof(sctp_addip_param_t); 2636 2637 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 2638 if (af == NULL) 2639 break; 2640 2641 af->from_addr_param(&addr, addr_param, 2642 htons(asoc->peer.port), 0); 2643 2644 /* if the address is invalid, we can't process it. 2645 * XXX: see spec for what to do. 2646 */ 2647 if (!af->addr_valid(&addr, NULL, NULL)) 2648 break; 2649 2650 t = sctp_assoc_lookup_paddr(asoc, &addr); 2651 if (!t) 2652 break; 2653 2654 sctp_assoc_set_primary(asoc, t); 2655 break; 2656 2657 case SCTP_PARAM_SUPPORTED_EXT: 2658 sctp_process_ext_param(asoc, param); 2659 break; 2660 2661 case SCTP_PARAM_FWD_TSN_SUPPORT: 2662 if (asoc->prsctp_enable) { 2663 asoc->peer.prsctp_capable = 1; 2664 break; 2665 } 2666 /* Fall Through */ 2667 goto fall_through; 2668 2669 case SCTP_PARAM_RANDOM: 2670 if (!ep->auth_enable) 2671 goto fall_through; 2672 2673 /* Save peer's random parameter */ 2674 asoc->peer.peer_random = kmemdup(param.p, 2675 ntohs(param.p->length), gfp); 2676 if (!asoc->peer.peer_random) { 2677 retval = 0; 2678 break; 2679 } 2680 break; 2681 2682 case SCTP_PARAM_HMAC_ALGO: 2683 if (!ep->auth_enable) 2684 goto fall_through; 2685 2686 /* Save peer's HMAC list */ 2687 asoc->peer.peer_hmacs = kmemdup(param.p, 2688 ntohs(param.p->length), gfp); 2689 if (!asoc->peer.peer_hmacs) { 2690 retval = 0; 2691 break; 2692 } 2693 2694 /* Set the default HMAC the peer requested*/ 2695 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2696 break; 2697 2698 case SCTP_PARAM_CHUNKS: 2699 if (!ep->auth_enable) 2700 goto fall_through; 2701 2702 asoc->peer.peer_chunks = kmemdup(param.p, 2703 ntohs(param.p->length), gfp); 2704 if (!asoc->peer.peer_chunks) 2705 retval = 0; 2706 break; 2707 fall_through: 2708 default: 2709 /* Any unrecognized parameters should have been caught 2710 * and handled by sctp_verify_param() which should be 2711 * called prior to this routine. Simply log the error 2712 * here. 2713 */ 2714 pr_debug("%s: ignoring param:%d for association:%p.\n", 2715 __func__, ntohs(param.p->type), asoc); 2716 break; 2717 } 2718 2719 return retval; 2720 } 2721 2722 /* Select a new verification tag. */ 2723 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2724 { 2725 /* I believe that this random number generator complies with RFC1750. 2726 * A tag of 0 is reserved for special cases (e.g. INIT). 2727 */ 2728 __u32 x; 2729 2730 do { 2731 get_random_bytes(&x, sizeof(__u32)); 2732 } while (x == 0); 2733 2734 return x; 2735 } 2736 2737 /* Select an initial TSN to send during startup. */ 2738 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2739 { 2740 __u32 retval; 2741 2742 get_random_bytes(&retval, sizeof(__u32)); 2743 return retval; 2744 } 2745 2746 /* 2747 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2748 * 0 1 2 3 2749 * 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 2750 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2751 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2752 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2753 * | Serial Number | 2754 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2755 * | Address Parameter | 2756 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2757 * | ASCONF Parameter #1 | 2758 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2759 * \ \ 2760 * / .... / 2761 * \ \ 2762 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2763 * | ASCONF Parameter #N | 2764 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2765 * 2766 * Address Parameter and other parameter will not be wrapped in this function 2767 */ 2768 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2769 union sctp_addr *addr, 2770 int vparam_len) 2771 { 2772 sctp_addiphdr_t asconf; 2773 struct sctp_chunk *retval; 2774 int length = sizeof(asconf) + vparam_len; 2775 union sctp_addr_param addrparam; 2776 int addrlen; 2777 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2778 2779 addrlen = af->to_addr_param(addr, &addrparam); 2780 if (!addrlen) 2781 return NULL; 2782 length += addrlen; 2783 2784 /* Create the chunk. */ 2785 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length, 2786 GFP_ATOMIC); 2787 if (!retval) 2788 return NULL; 2789 2790 asconf.serial = htonl(asoc->addip_serial++); 2791 2792 retval->subh.addip_hdr = 2793 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2794 retval->param_hdr.v = 2795 sctp_addto_chunk(retval, addrlen, &addrparam); 2796 2797 return retval; 2798 } 2799 2800 /* ADDIP 2801 * 3.2.1 Add IP Address 2802 * 0 1 2 3 2803 * 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 2804 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2805 * | Type = 0xC001 | Length = Variable | 2806 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2807 * | ASCONF-Request Correlation ID | 2808 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2809 * | Address Parameter | 2810 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2811 * 2812 * 3.2.2 Delete IP Address 2813 * 0 1 2 3 2814 * 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 2815 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2816 * | Type = 0xC002 | Length = Variable | 2817 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2818 * | ASCONF-Request Correlation ID | 2819 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2820 * | Address Parameter | 2821 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2822 * 2823 */ 2824 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2825 union sctp_addr *laddr, 2826 struct sockaddr *addrs, 2827 int addrcnt, 2828 __be16 flags) 2829 { 2830 sctp_addip_param_t param; 2831 struct sctp_chunk *retval; 2832 union sctp_addr_param addr_param; 2833 union sctp_addr *addr; 2834 void *addr_buf; 2835 struct sctp_af *af; 2836 int paramlen = sizeof(param); 2837 int addr_param_len = 0; 2838 int totallen = 0; 2839 int i; 2840 int del_pickup = 0; 2841 2842 /* Get total length of all the address parameters. */ 2843 addr_buf = addrs; 2844 for (i = 0; i < addrcnt; i++) { 2845 addr = addr_buf; 2846 af = sctp_get_af_specific(addr->v4.sin_family); 2847 addr_param_len = af->to_addr_param(addr, &addr_param); 2848 2849 totallen += paramlen; 2850 totallen += addr_param_len; 2851 2852 addr_buf += af->sockaddr_len; 2853 if (asoc->asconf_addr_del_pending && !del_pickup) { 2854 /* reuse the parameter length from the same scope one */ 2855 totallen += paramlen; 2856 totallen += addr_param_len; 2857 del_pickup = 1; 2858 2859 pr_debug("%s: picked same-scope del_pending addr, " 2860 "totallen for all addresses is %d\n", 2861 __func__, totallen); 2862 } 2863 } 2864 2865 /* Create an asconf chunk with the required length. */ 2866 retval = sctp_make_asconf(asoc, laddr, totallen); 2867 if (!retval) 2868 return NULL; 2869 2870 /* Add the address parameters to the asconf chunk. */ 2871 addr_buf = addrs; 2872 for (i = 0; i < addrcnt; i++) { 2873 addr = addr_buf; 2874 af = sctp_get_af_specific(addr->v4.sin_family); 2875 addr_param_len = af->to_addr_param(addr, &addr_param); 2876 param.param_hdr.type = flags; 2877 param.param_hdr.length = htons(paramlen + addr_param_len); 2878 param.crr_id = i; 2879 2880 sctp_addto_chunk(retval, paramlen, ¶m); 2881 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2882 2883 addr_buf += af->sockaddr_len; 2884 } 2885 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2886 addr = asoc->asconf_addr_del_pending; 2887 af = sctp_get_af_specific(addr->v4.sin_family); 2888 addr_param_len = af->to_addr_param(addr, &addr_param); 2889 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2890 param.param_hdr.length = htons(paramlen + addr_param_len); 2891 param.crr_id = i; 2892 2893 sctp_addto_chunk(retval, paramlen, ¶m); 2894 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2895 } 2896 return retval; 2897 } 2898 2899 /* ADDIP 2900 * 3.2.4 Set Primary IP Address 2901 * 0 1 2 3 2902 * 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 2903 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2904 * | Type =0xC004 | Length = Variable | 2905 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2906 * | ASCONF-Request Correlation ID | 2907 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2908 * | Address Parameter | 2909 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2910 * 2911 * Create an ASCONF chunk with Set Primary IP address parameter. 2912 */ 2913 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2914 union sctp_addr *addr) 2915 { 2916 sctp_addip_param_t param; 2917 struct sctp_chunk *retval; 2918 int len = sizeof(param); 2919 union sctp_addr_param addrparam; 2920 int addrlen; 2921 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2922 2923 addrlen = af->to_addr_param(addr, &addrparam); 2924 if (!addrlen) 2925 return NULL; 2926 len += addrlen; 2927 2928 /* Create the chunk and make asconf header. */ 2929 retval = sctp_make_asconf(asoc, addr, len); 2930 if (!retval) 2931 return NULL; 2932 2933 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2934 param.param_hdr.length = htons(len); 2935 param.crr_id = 0; 2936 2937 sctp_addto_chunk(retval, sizeof(param), ¶m); 2938 sctp_addto_chunk(retval, addrlen, &addrparam); 2939 2940 return retval; 2941 } 2942 2943 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2944 * 0 1 2 3 2945 * 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 2946 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2947 * | Type = 0x80 | Chunk Flags | Chunk Length | 2948 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2949 * | Serial Number | 2950 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2951 * | ASCONF Parameter Response#1 | 2952 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2953 * \ \ 2954 * / .... / 2955 * \ \ 2956 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2957 * | ASCONF Parameter Response#N | 2958 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2959 * 2960 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2961 */ 2962 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2963 __u32 serial, int vparam_len) 2964 { 2965 sctp_addiphdr_t asconf; 2966 struct sctp_chunk *retval; 2967 int length = sizeof(asconf) + vparam_len; 2968 2969 /* Create the chunk. */ 2970 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length, 2971 GFP_ATOMIC); 2972 if (!retval) 2973 return NULL; 2974 2975 asconf.serial = htonl(serial); 2976 2977 retval->subh.addip_hdr = 2978 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2979 2980 return retval; 2981 } 2982 2983 /* Add response parameters to an ASCONF_ACK chunk. */ 2984 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2985 __be16 err_code, sctp_addip_param_t *asconf_param) 2986 { 2987 sctp_addip_param_t ack_param; 2988 sctp_errhdr_t err_param; 2989 int asconf_param_len = 0; 2990 int err_param_len = 0; 2991 __be16 response_type; 2992 2993 if (SCTP_ERROR_NO_ERROR == err_code) { 2994 response_type = SCTP_PARAM_SUCCESS_REPORT; 2995 } else { 2996 response_type = SCTP_PARAM_ERR_CAUSE; 2997 err_param_len = sizeof(err_param); 2998 if (asconf_param) 2999 asconf_param_len = 3000 ntohs(asconf_param->param_hdr.length); 3001 } 3002 3003 /* Add Success Indication or Error Cause Indication parameter. */ 3004 ack_param.param_hdr.type = response_type; 3005 ack_param.param_hdr.length = htons(sizeof(ack_param) + 3006 err_param_len + 3007 asconf_param_len); 3008 ack_param.crr_id = crr_id; 3009 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 3010 3011 if (SCTP_ERROR_NO_ERROR == err_code) 3012 return; 3013 3014 /* Add Error Cause parameter. */ 3015 err_param.cause = err_code; 3016 err_param.length = htons(err_param_len + asconf_param_len); 3017 sctp_addto_chunk(chunk, err_param_len, &err_param); 3018 3019 /* Add the failed TLV copied from ASCONF chunk. */ 3020 if (asconf_param) 3021 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 3022 } 3023 3024 /* Process a asconf parameter. */ 3025 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 3026 struct sctp_chunk *asconf, 3027 sctp_addip_param_t *asconf_param) 3028 { 3029 struct sctp_transport *peer; 3030 struct sctp_af *af; 3031 union sctp_addr addr; 3032 union sctp_addr_param *addr_param; 3033 3034 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t); 3035 3036 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 3037 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 3038 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 3039 return SCTP_ERROR_UNKNOWN_PARAM; 3040 3041 switch (addr_param->p.type) { 3042 case SCTP_PARAM_IPV6_ADDRESS: 3043 if (!asoc->peer.ipv6_address) 3044 return SCTP_ERROR_DNS_FAILED; 3045 break; 3046 case SCTP_PARAM_IPV4_ADDRESS: 3047 if (!asoc->peer.ipv4_address) 3048 return SCTP_ERROR_DNS_FAILED; 3049 break; 3050 default: 3051 return SCTP_ERROR_DNS_FAILED; 3052 } 3053 3054 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3055 if (unlikely(!af)) 3056 return SCTP_ERROR_DNS_FAILED; 3057 3058 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); 3059 3060 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3061 * or multicast address. 3062 * (note: wildcard is permitted and requires special handling so 3063 * make sure we check for that) 3064 */ 3065 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3066 return SCTP_ERROR_DNS_FAILED; 3067 3068 switch (asconf_param->param_hdr.type) { 3069 case SCTP_PARAM_ADD_IP: 3070 /* Section 4.2.1: 3071 * If the address 0.0.0.0 or ::0 is provided, the source 3072 * address of the packet MUST be added. 3073 */ 3074 if (af->is_any(&addr)) 3075 memcpy(&addr, &asconf->source, sizeof(addr)); 3076 3077 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3078 * request and does not have the local resources to add this 3079 * new address to the association, it MUST return an Error 3080 * Cause TLV set to the new error code 'Operation Refused 3081 * Due to Resource Shortage'. 3082 */ 3083 3084 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3085 if (!peer) 3086 return SCTP_ERROR_RSRC_LOW; 3087 3088 /* Start the heartbeat timer. */ 3089 sctp_transport_reset_hb_timer(peer); 3090 asoc->new_transport = peer; 3091 break; 3092 case SCTP_PARAM_DEL_IP: 3093 /* ADDIP 4.3 D7) If a request is received to delete the 3094 * last remaining IP address of a peer endpoint, the receiver 3095 * MUST send an Error Cause TLV with the error cause set to the 3096 * new error code 'Request to Delete Last Remaining IP Address'. 3097 */ 3098 if (asoc->peer.transport_count == 1) 3099 return SCTP_ERROR_DEL_LAST_IP; 3100 3101 /* ADDIP 4.3 D8) If a request is received to delete an IP 3102 * address which is also the source address of the IP packet 3103 * which contained the ASCONF chunk, the receiver MUST reject 3104 * this request. To reject the request the receiver MUST send 3105 * an Error Cause TLV set to the new error code 'Request to 3106 * Delete Source IP Address' 3107 */ 3108 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3109 return SCTP_ERROR_DEL_SRC_IP; 3110 3111 /* Section 4.2.2 3112 * If the address 0.0.0.0 or ::0 is provided, all 3113 * addresses of the peer except the source address of the 3114 * packet MUST be deleted. 3115 */ 3116 if (af->is_any(&addr)) { 3117 sctp_assoc_set_primary(asoc, asconf->transport); 3118 sctp_assoc_del_nonprimary_peers(asoc, 3119 asconf->transport); 3120 return SCTP_ERROR_NO_ERROR; 3121 } 3122 3123 /* If the address is not part of the association, the 3124 * ASCONF-ACK with Error Cause Indication Parameter 3125 * which including cause of Unresolvable Address should 3126 * be sent. 3127 */ 3128 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3129 if (!peer) 3130 return SCTP_ERROR_DNS_FAILED; 3131 3132 sctp_assoc_rm_peer(asoc, peer); 3133 break; 3134 case SCTP_PARAM_SET_PRIMARY: 3135 /* ADDIP Section 4.2.4 3136 * If the address 0.0.0.0 or ::0 is provided, the receiver 3137 * MAY mark the source address of the packet as its 3138 * primary. 3139 */ 3140 if (af->is_any(&addr)) 3141 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr)); 3142 3143 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3144 if (!peer) 3145 return SCTP_ERROR_DNS_FAILED; 3146 3147 sctp_assoc_set_primary(asoc, peer); 3148 break; 3149 } 3150 3151 return SCTP_ERROR_NO_ERROR; 3152 } 3153 3154 /* Verify the ASCONF packet before we process it. */ 3155 bool sctp_verify_asconf(const struct sctp_association *asoc, 3156 struct sctp_chunk *chunk, bool addr_param_needed, 3157 struct sctp_paramhdr **errp) 3158 { 3159 sctp_addip_chunk_t *addip = (sctp_addip_chunk_t *) chunk->chunk_hdr; 3160 union sctp_params param; 3161 bool addr_param_seen = false; 3162 3163 sctp_walk_params(param, addip, addip_hdr.params) { 3164 size_t length = ntohs(param.p->length); 3165 3166 *errp = param.p; 3167 switch (param.p->type) { 3168 case SCTP_PARAM_ERR_CAUSE: 3169 break; 3170 case SCTP_PARAM_IPV4_ADDRESS: 3171 if (length != sizeof(sctp_ipv4addr_param_t)) 3172 return false; 3173 /* ensure there is only one addr param and it's in the 3174 * beginning of addip_hdr params, or we reject it. 3175 */ 3176 if (param.v != addip->addip_hdr.params) 3177 return false; 3178 addr_param_seen = true; 3179 break; 3180 case SCTP_PARAM_IPV6_ADDRESS: 3181 if (length != sizeof(sctp_ipv6addr_param_t)) 3182 return false; 3183 if (param.v != addip->addip_hdr.params) 3184 return false; 3185 addr_param_seen = true; 3186 break; 3187 case SCTP_PARAM_ADD_IP: 3188 case SCTP_PARAM_DEL_IP: 3189 case SCTP_PARAM_SET_PRIMARY: 3190 /* In ASCONF chunks, these need to be first. */ 3191 if (addr_param_needed && !addr_param_seen) 3192 return false; 3193 length = ntohs(param.addip->param_hdr.length); 3194 if (length < sizeof(sctp_addip_param_t) + 3195 sizeof(sctp_paramhdr_t)) 3196 return false; 3197 break; 3198 case SCTP_PARAM_SUCCESS_REPORT: 3199 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3200 if (length != sizeof(sctp_addip_param_t)) 3201 return false; 3202 break; 3203 default: 3204 /* This is unkown to us, reject! */ 3205 return false; 3206 } 3207 } 3208 3209 /* Remaining sanity checks. */ 3210 if (addr_param_needed && !addr_param_seen) 3211 return false; 3212 if (!addr_param_needed && addr_param_seen) 3213 return false; 3214 if (param.v != chunk->chunk_end) 3215 return false; 3216 3217 return true; 3218 } 3219 3220 /* Process an incoming ASCONF chunk with the next expected serial no. and 3221 * return an ASCONF_ACK chunk to be sent in response. 3222 */ 3223 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3224 struct sctp_chunk *asconf) 3225 { 3226 sctp_addip_chunk_t *addip = (sctp_addip_chunk_t *) asconf->chunk_hdr; 3227 bool all_param_pass = true; 3228 union sctp_params param; 3229 sctp_addiphdr_t *hdr; 3230 union sctp_addr_param *addr_param; 3231 struct sctp_chunk *asconf_ack; 3232 __be16 err_code; 3233 int length = 0; 3234 int chunk_len; 3235 __u32 serial; 3236 3237 chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t); 3238 hdr = (sctp_addiphdr_t *)asconf->skb->data; 3239 serial = ntohl(hdr->serial); 3240 3241 /* Skip the addiphdr and store a pointer to address parameter. */ 3242 length = sizeof(sctp_addiphdr_t); 3243 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3244 chunk_len -= length; 3245 3246 /* Skip the address parameter and store a pointer to the first 3247 * asconf parameter. 3248 */ 3249 length = ntohs(addr_param->p.length); 3250 chunk_len -= length; 3251 3252 /* create an ASCONF_ACK chunk. 3253 * Based on the definitions of parameters, we know that the size of 3254 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3255 * parameters. 3256 */ 3257 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3258 if (!asconf_ack) 3259 goto done; 3260 3261 /* Process the TLVs contained within the ASCONF chunk. */ 3262 sctp_walk_params(param, addip, addip_hdr.params) { 3263 /* Skip preceeding address parameters. */ 3264 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 3265 param.p->type == SCTP_PARAM_IPV6_ADDRESS) 3266 continue; 3267 3268 err_code = sctp_process_asconf_param(asoc, asconf, 3269 param.addip); 3270 /* ADDIP 4.1 A7) 3271 * If an error response is received for a TLV parameter, 3272 * all TLVs with no response before the failed TLV are 3273 * considered successful if not reported. All TLVs after 3274 * the failed response are considered unsuccessful unless 3275 * a specific success indication is present for the parameter. 3276 */ 3277 if (err_code != SCTP_ERROR_NO_ERROR) 3278 all_param_pass = false; 3279 if (!all_param_pass) 3280 sctp_add_asconf_response(asconf_ack, param.addip->crr_id, 3281 err_code, param.addip); 3282 3283 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3284 * an IP address sends an 'Out of Resource' in its response, it 3285 * MUST also fail any subsequent add or delete requests bundled 3286 * in the ASCONF. 3287 */ 3288 if (err_code == SCTP_ERROR_RSRC_LOW) 3289 goto done; 3290 } 3291 done: 3292 asoc->peer.addip_serial++; 3293 3294 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3295 * after freeing the reference to old asconf ack if any. 3296 */ 3297 if (asconf_ack) { 3298 sctp_chunk_hold(asconf_ack); 3299 list_add_tail(&asconf_ack->transmitted_list, 3300 &asoc->asconf_ack_list); 3301 } 3302 3303 return asconf_ack; 3304 } 3305 3306 /* Process a asconf parameter that is successfully acked. */ 3307 static void sctp_asconf_param_success(struct sctp_association *asoc, 3308 sctp_addip_param_t *asconf_param) 3309 { 3310 struct sctp_af *af; 3311 union sctp_addr addr; 3312 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3313 union sctp_addr_param *addr_param; 3314 struct sctp_transport *transport; 3315 struct sctp_sockaddr_entry *saddr; 3316 3317 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t); 3318 3319 /* We have checked the packet before, so we do not check again. */ 3320 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3321 af->from_addr_param(&addr, addr_param, htons(bp->port), 0); 3322 3323 switch (asconf_param->param_hdr.type) { 3324 case SCTP_PARAM_ADD_IP: 3325 /* This is always done in BH context with a socket lock 3326 * held, so the list can not change. 3327 */ 3328 local_bh_disable(); 3329 list_for_each_entry(saddr, &bp->address_list, list) { 3330 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3331 saddr->state = SCTP_ADDR_SRC; 3332 } 3333 local_bh_enable(); 3334 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3335 transports) { 3336 sctp_transport_dst_release(transport); 3337 } 3338 break; 3339 case SCTP_PARAM_DEL_IP: 3340 local_bh_disable(); 3341 sctp_del_bind_addr(bp, &addr); 3342 if (asoc->asconf_addr_del_pending != NULL && 3343 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3344 kfree(asoc->asconf_addr_del_pending); 3345 asoc->asconf_addr_del_pending = NULL; 3346 } 3347 local_bh_enable(); 3348 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3349 transports) { 3350 sctp_transport_dst_release(transport); 3351 } 3352 break; 3353 default: 3354 break; 3355 } 3356 } 3357 3358 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3359 * for the given asconf parameter. If there is no response for this parameter, 3360 * return the error code based on the third argument 'no_err'. 3361 * ADDIP 4.1 3362 * A7) If an error response is received for a TLV parameter, all TLVs with no 3363 * response before the failed TLV are considered successful if not reported. 3364 * All TLVs after the failed response are considered unsuccessful unless a 3365 * specific success indication is present for the parameter. 3366 */ 3367 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3368 sctp_addip_param_t *asconf_param, 3369 int no_err) 3370 { 3371 sctp_addip_param_t *asconf_ack_param; 3372 sctp_errhdr_t *err_param; 3373 int length; 3374 int asconf_ack_len; 3375 __be16 err_code; 3376 3377 if (no_err) 3378 err_code = SCTP_ERROR_NO_ERROR; 3379 else 3380 err_code = SCTP_ERROR_REQ_REFUSED; 3381 3382 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3383 sizeof(sctp_chunkhdr_t); 3384 3385 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3386 * the first asconf_ack parameter. 3387 */ 3388 length = sizeof(sctp_addiphdr_t); 3389 asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data + 3390 length); 3391 asconf_ack_len -= length; 3392 3393 while (asconf_ack_len > 0) { 3394 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3395 switch (asconf_ack_param->param_hdr.type) { 3396 case SCTP_PARAM_SUCCESS_REPORT: 3397 return SCTP_ERROR_NO_ERROR; 3398 case SCTP_PARAM_ERR_CAUSE: 3399 length = sizeof(sctp_addip_param_t); 3400 err_param = (void *)asconf_ack_param + length; 3401 asconf_ack_len -= length; 3402 if (asconf_ack_len > 0) 3403 return err_param->cause; 3404 else 3405 return SCTP_ERROR_INV_PARAM; 3406 break; 3407 default: 3408 return SCTP_ERROR_INV_PARAM; 3409 } 3410 } 3411 3412 length = ntohs(asconf_ack_param->param_hdr.length); 3413 asconf_ack_param = (void *)asconf_ack_param + length; 3414 asconf_ack_len -= length; 3415 } 3416 3417 return err_code; 3418 } 3419 3420 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3421 int sctp_process_asconf_ack(struct sctp_association *asoc, 3422 struct sctp_chunk *asconf_ack) 3423 { 3424 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3425 union sctp_addr_param *addr_param; 3426 sctp_addip_param_t *asconf_param; 3427 int length = 0; 3428 int asconf_len = asconf->skb->len; 3429 int all_param_pass = 0; 3430 int no_err = 1; 3431 int retval = 0; 3432 __be16 err_code = SCTP_ERROR_NO_ERROR; 3433 3434 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3435 * a pointer to address parameter. 3436 */ 3437 length = sizeof(sctp_addip_chunk_t); 3438 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3439 asconf_len -= length; 3440 3441 /* Skip the address parameter in the last asconf sent and store a 3442 * pointer to the first asconf parameter. 3443 */ 3444 length = ntohs(addr_param->p.length); 3445 asconf_param = (void *)addr_param + length; 3446 asconf_len -= length; 3447 3448 /* ADDIP 4.1 3449 * A8) If there is no response(s) to specific TLV parameter(s), and no 3450 * failures are indicated, then all request(s) are considered 3451 * successful. 3452 */ 3453 if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t)) 3454 all_param_pass = 1; 3455 3456 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3457 while (asconf_len > 0) { 3458 if (all_param_pass) 3459 err_code = SCTP_ERROR_NO_ERROR; 3460 else { 3461 err_code = sctp_get_asconf_response(asconf_ack, 3462 asconf_param, 3463 no_err); 3464 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3465 no_err = 0; 3466 } 3467 3468 switch (err_code) { 3469 case SCTP_ERROR_NO_ERROR: 3470 sctp_asconf_param_success(asoc, asconf_param); 3471 break; 3472 3473 case SCTP_ERROR_RSRC_LOW: 3474 retval = 1; 3475 break; 3476 3477 case SCTP_ERROR_UNKNOWN_PARAM: 3478 /* Disable sending this type of asconf parameter in 3479 * future. 3480 */ 3481 asoc->peer.addip_disabled_mask |= 3482 asconf_param->param_hdr.type; 3483 break; 3484 3485 case SCTP_ERROR_REQ_REFUSED: 3486 case SCTP_ERROR_DEL_LAST_IP: 3487 case SCTP_ERROR_DEL_SRC_IP: 3488 default: 3489 break; 3490 } 3491 3492 /* Skip the processed asconf parameter and move to the next 3493 * one. 3494 */ 3495 length = ntohs(asconf_param->param_hdr.length); 3496 asconf_param = (void *)asconf_param + length; 3497 asconf_len -= length; 3498 } 3499 3500 if (no_err && asoc->src_out_of_asoc_ok) { 3501 asoc->src_out_of_asoc_ok = 0; 3502 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3503 } 3504 3505 /* Free the cached last sent asconf chunk. */ 3506 list_del_init(&asconf->transmitted_list); 3507 sctp_chunk_free(asconf); 3508 asoc->addip_last_asconf = NULL; 3509 3510 return retval; 3511 } 3512 3513 /* Make a FWD TSN chunk. */ 3514 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3515 __u32 new_cum_tsn, size_t nstreams, 3516 struct sctp_fwdtsn_skip *skiplist) 3517 { 3518 struct sctp_chunk *retval = NULL; 3519 struct sctp_fwdtsn_hdr ftsn_hdr; 3520 struct sctp_fwdtsn_skip skip; 3521 size_t hint; 3522 int i; 3523 3524 hint = (nstreams + 1) * sizeof(__u32); 3525 3526 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC); 3527 3528 if (!retval) 3529 return NULL; 3530 3531 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3532 retval->subh.fwdtsn_hdr = 3533 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3534 3535 for (i = 0; i < nstreams; i++) { 3536 skip.stream = skiplist[i].stream; 3537 skip.ssn = skiplist[i].ssn; 3538 sctp_addto_chunk(retval, sizeof(skip), &skip); 3539 } 3540 3541 return retval; 3542 } 3543 3544 /* RE-CONFIG 3.1 (RE-CONFIG chunk) 3545 * 0 1 2 3 3546 * 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 3547 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3548 * | Type = 130 | Chunk Flags | Chunk Length | 3549 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3550 * \ \ 3551 * / Re-configuration Parameter / 3552 * \ \ 3553 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3554 * \ \ 3555 * / Re-configuration Parameter (optional) / 3556 * \ \ 3557 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3558 */ 3559 static struct sctp_chunk *sctp_make_reconf( 3560 const struct sctp_association *asoc, 3561 int length) 3562 { 3563 struct sctp_reconf_chunk *reconf; 3564 struct sctp_chunk *retval; 3565 3566 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length, 3567 GFP_ATOMIC); 3568 if (!retval) 3569 return NULL; 3570 3571 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr; 3572 retval->param_hdr.v = reconf->params; 3573 3574 return retval; 3575 } 3576 3577 /* RE-CONFIG 4.1 (STREAM OUT RESET) 3578 * 0 1 2 3 3579 * 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 3580 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3581 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N | 3582 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3583 * | Re-configuration Request Sequence Number | 3584 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3585 * | Re-configuration Response Sequence Number | 3586 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3587 * | Sender's Last Assigned TSN | 3588 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3589 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3590 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3591 * / ...... / 3592 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3593 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3594 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3595 * 3596 * RE-CONFIG 4.2 (STREAM IN RESET) 3597 * 0 1 2 3 3598 * 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 3599 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3600 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N | 3601 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3602 * | Re-configuration Request Sequence Number | 3603 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3604 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3605 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3606 * / ...... / 3607 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3608 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3609 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3610 */ 3611 struct sctp_chunk *sctp_make_strreset_req( 3612 const struct sctp_association *asoc, 3613 __u16 stream_num, __u16 *stream_list, 3614 bool out, bool in) 3615 { 3616 struct sctp_strreset_outreq outreq; 3617 __u16 stream_len = stream_num * 2; 3618 struct sctp_strreset_inreq inreq; 3619 struct sctp_chunk *retval; 3620 __u16 outlen, inlen; 3621 3622 outlen = (sizeof(outreq) + stream_len) * out; 3623 inlen = (sizeof(inreq) + stream_len) * in; 3624 3625 retval = sctp_make_reconf(asoc, outlen + inlen); 3626 if (!retval) 3627 return NULL; 3628 3629 if (outlen) { 3630 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST; 3631 outreq.param_hdr.length = htons(outlen); 3632 outreq.request_seq = htonl(asoc->strreset_outseq); 3633 outreq.response_seq = htonl(asoc->strreset_inseq - 1); 3634 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1); 3635 3636 sctp_addto_chunk(retval, sizeof(outreq), &outreq); 3637 3638 if (stream_len) 3639 sctp_addto_chunk(retval, stream_len, stream_list); 3640 } 3641 3642 if (inlen) { 3643 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST; 3644 inreq.param_hdr.length = htons(inlen); 3645 inreq.request_seq = htonl(asoc->strreset_outseq + out); 3646 3647 sctp_addto_chunk(retval, sizeof(inreq), &inreq); 3648 3649 if (stream_len) 3650 sctp_addto_chunk(retval, stream_len, stream_list); 3651 } 3652 3653 return retval; 3654 } 3655 3656 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL) 3657 * 0 1 2 3 3658 * 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 3659 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3660 * | Parameter Type = 15 | Parameter Length = 8 | 3661 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3662 * | Re-configuration Request Sequence Number | 3663 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3664 */ 3665 struct sctp_chunk *sctp_make_strreset_tsnreq( 3666 const struct sctp_association *asoc) 3667 { 3668 struct sctp_strreset_tsnreq tsnreq; 3669 __u16 length = sizeof(tsnreq); 3670 struct sctp_chunk *retval; 3671 3672 retval = sctp_make_reconf(asoc, length); 3673 if (!retval) 3674 return NULL; 3675 3676 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST; 3677 tsnreq.param_hdr.length = htons(length); 3678 tsnreq.request_seq = htonl(asoc->strreset_outseq); 3679 3680 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq); 3681 3682 return retval; 3683 } 3684 3685 /* RE-CONFIG 4.5/4.6 (ADD STREAM) 3686 * 0 1 2 3 3687 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 3688 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3689 * | Parameter Type = 17 | Parameter Length = 12 | 3690 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3691 * | Re-configuration Request Sequence Number | 3692 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3693 * | Number of new streams | Reserved | 3694 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3695 */ 3696 struct sctp_chunk *sctp_make_strreset_addstrm( 3697 const struct sctp_association *asoc, 3698 __u16 out, __u16 in) 3699 { 3700 struct sctp_strreset_addstrm addstrm; 3701 __u16 size = sizeof(addstrm); 3702 struct sctp_chunk *retval; 3703 3704 retval = sctp_make_reconf(asoc, (!!out + !!in) * size); 3705 if (!retval) 3706 return NULL; 3707 3708 if (out) { 3709 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS; 3710 addstrm.param_hdr.length = htons(size); 3711 addstrm.number_of_streams = htons(out); 3712 addstrm.request_seq = htonl(asoc->strreset_outseq); 3713 addstrm.reserved = 0; 3714 3715 sctp_addto_chunk(retval, size, &addstrm); 3716 } 3717 3718 if (in) { 3719 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS; 3720 addstrm.param_hdr.length = htons(size); 3721 addstrm.number_of_streams = htons(in); 3722 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out); 3723 addstrm.reserved = 0; 3724 3725 sctp_addto_chunk(retval, size, &addstrm); 3726 } 3727 3728 return retval; 3729 } 3730 3731 /* RE-CONFIG 4.4 (RESP) 3732 * 0 1 2 3 3733 * 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 3734 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3735 * | Parameter Type = 16 | Parameter Length | 3736 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3737 * | Re-configuration Response Sequence Number | 3738 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3739 * | Result | 3740 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3741 */ 3742 struct sctp_chunk *sctp_make_strreset_resp( 3743 const struct sctp_association *asoc, 3744 __u32 result, __u32 sn) 3745 { 3746 struct sctp_strreset_resp resp; 3747 __u16 length = sizeof(resp); 3748 struct sctp_chunk *retval; 3749 3750 retval = sctp_make_reconf(asoc, length); 3751 if (!retval) 3752 return NULL; 3753 3754 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3755 resp.param_hdr.length = htons(length); 3756 resp.response_seq = htonl(sn); 3757 resp.result = htonl(result); 3758 3759 sctp_addto_chunk(retval, sizeof(resp), &resp); 3760 3761 return retval; 3762 } 3763 3764 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP) 3765 * 0 1 2 3 3766 * 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 3767 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3768 * | Parameter Type = 16 | Parameter Length | 3769 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3770 * | Re-configuration Response Sequence Number | 3771 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3772 * | Result | 3773 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3774 * | Sender's Next TSN (optional) | 3775 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3776 * | Receiver's Next TSN (optional) | 3777 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3778 */ 3779 struct sctp_chunk *sctp_make_strreset_tsnresp( 3780 struct sctp_association *asoc, 3781 __u32 result, __u32 sn, 3782 __u32 sender_tsn, __u32 receiver_tsn) 3783 { 3784 struct sctp_strreset_resptsn tsnresp; 3785 __u16 length = sizeof(tsnresp); 3786 struct sctp_chunk *retval; 3787 3788 retval = sctp_make_reconf(asoc, length); 3789 if (!retval) 3790 return NULL; 3791 3792 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3793 tsnresp.param_hdr.length = htons(length); 3794 3795 tsnresp.response_seq = htonl(sn); 3796 tsnresp.result = htonl(result); 3797 tsnresp.senders_next_tsn = htonl(sender_tsn); 3798 tsnresp.receivers_next_tsn = htonl(receiver_tsn); 3799 3800 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp); 3801 3802 return retval; 3803 } 3804 3805 bool sctp_verify_reconf(const struct sctp_association *asoc, 3806 struct sctp_chunk *chunk, 3807 struct sctp_paramhdr **errp) 3808 { 3809 struct sctp_reconf_chunk *hdr; 3810 union sctp_params param; 3811 __u16 last = 0, cnt = 0; 3812 3813 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; 3814 sctp_walk_params(param, hdr, params) { 3815 __u16 length = ntohs(param.p->length); 3816 3817 *errp = param.p; 3818 if (cnt++ > 2) 3819 return false; 3820 switch (param.p->type) { 3821 case SCTP_PARAM_RESET_OUT_REQUEST: 3822 if (length < sizeof(struct sctp_strreset_outreq) || 3823 (last && last != SCTP_PARAM_RESET_RESPONSE && 3824 last != SCTP_PARAM_RESET_IN_REQUEST)) 3825 return false; 3826 break; 3827 case SCTP_PARAM_RESET_IN_REQUEST: 3828 if (length < sizeof(struct sctp_strreset_inreq) || 3829 (last && last != SCTP_PARAM_RESET_OUT_REQUEST)) 3830 return false; 3831 break; 3832 case SCTP_PARAM_RESET_RESPONSE: 3833 if ((length != sizeof(struct sctp_strreset_resp) && 3834 length != sizeof(struct sctp_strreset_resptsn)) || 3835 (last && last != SCTP_PARAM_RESET_RESPONSE && 3836 last != SCTP_PARAM_RESET_OUT_REQUEST)) 3837 return false; 3838 break; 3839 case SCTP_PARAM_RESET_TSN_REQUEST: 3840 if (length != 3841 sizeof(struct sctp_strreset_tsnreq) || last) 3842 return false; 3843 break; 3844 case SCTP_PARAM_RESET_ADD_IN_STREAMS: 3845 if (length != sizeof(struct sctp_strreset_addstrm) || 3846 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS)) 3847 return false; 3848 break; 3849 case SCTP_PARAM_RESET_ADD_OUT_STREAMS: 3850 if (length != sizeof(struct sctp_strreset_addstrm) || 3851 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS)) 3852 return false; 3853 break; 3854 default: 3855 return false; 3856 } 3857 3858 last = param.p->type; 3859 } 3860 3861 return true; 3862 } 3863