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 struct sctp_inithdr 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[4]; 232 struct sctp_paramhdr *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 = (struct sctp_paramhdr *)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 = (struct sctp_paramhdr *)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 struct sctp_inithdr 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[4]; 400 struct sctp_paramhdr *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 = (struct sctp_paramhdr *)asoc->c.auth_random; 452 chunksize += ntohs(auth_random->length); 453 454 auth_hmacs = (struct sctp_paramhdr *)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 = (struct sctp_paramhdr *)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(phdr)); 1090 if (!retval) 1091 goto end; 1092 1093 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen + 1094 sizeof(phdr)); 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(phdr), &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(*param); 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(*param)); 1121 sctp_addto_chunk(retval, sizeof(error), error); 1122 sctp_addto_param(retval, sizeof(*param), 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_zero(retval->skb, hmac_desc->hmac_len); 1300 1301 /* Adjust the chunk header to include the empty MAC */ 1302 retval->chunk_hdr->length = 1303 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1304 retval->chunk_end = skb_tail_pointer(retval->skb); 1305 1306 return retval; 1307 } 1308 1309 1310 /******************************************************************** 1311 * 2nd Level Abstractions 1312 ********************************************************************/ 1313 1314 /* Turn an skb into a chunk. 1315 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1316 * 1317 * sctpimpguide-05.txt Section 2.8.2 1318 * M1) Each time a new DATA chunk is transmitted 1319 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1320 * 'TSN.Missing.Report' count will be used to determine missing chunks 1321 * and when to fast retransmit. 1322 * 1323 */ 1324 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1325 const struct sctp_association *asoc, 1326 struct sock *sk, gfp_t gfp) 1327 { 1328 struct sctp_chunk *retval; 1329 1330 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp); 1331 1332 if (!retval) 1333 goto nodata; 1334 if (!sk) 1335 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb); 1336 1337 INIT_LIST_HEAD(&retval->list); 1338 retval->skb = skb; 1339 retval->asoc = (struct sctp_association *)asoc; 1340 retval->singleton = 1; 1341 1342 retval->fast_retransmit = SCTP_CAN_FRTX; 1343 1344 /* Polish the bead hole. */ 1345 INIT_LIST_HEAD(&retval->transmitted_list); 1346 INIT_LIST_HEAD(&retval->frag_list); 1347 SCTP_DBG_OBJCNT_INC(chunk); 1348 refcount_set(&retval->refcnt, 1); 1349 1350 nodata: 1351 return retval; 1352 } 1353 1354 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1355 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1356 union sctp_addr *dest) 1357 { 1358 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1359 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1360 } 1361 1362 /* Extract the source address from a chunk. */ 1363 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1364 { 1365 /* If we have a known transport, use that. */ 1366 if (chunk->transport) { 1367 return &chunk->transport->ipaddr; 1368 } else { 1369 /* Otherwise, extract it from the IP header. */ 1370 return &chunk->source; 1371 } 1372 } 1373 1374 /* Create a new chunk, setting the type and flags headers from the 1375 * arguments, reserving enough space for a 'paylen' byte payload. 1376 */ 1377 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 1378 __u8 type, __u8 flags, int paylen, 1379 gfp_t gfp) 1380 { 1381 struct sctp_chunk *retval; 1382 struct sctp_chunkhdr *chunk_hdr; 1383 struct sk_buff *skb; 1384 struct sock *sk; 1385 1386 /* No need to allocate LL here, as this is only a chunk. */ 1387 skb = alloc_skb(SCTP_PAD4(sizeof(*chunk_hdr) + paylen), gfp); 1388 if (!skb) 1389 goto nodata; 1390 1391 /* Make room for the chunk header. */ 1392 chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr)); 1393 chunk_hdr->type = type; 1394 chunk_hdr->flags = flags; 1395 chunk_hdr->length = htons(sizeof(*chunk_hdr)); 1396 1397 sk = asoc ? asoc->base.sk : NULL; 1398 retval = sctp_chunkify(skb, asoc, sk, gfp); 1399 if (!retval) { 1400 kfree_skb(skb); 1401 goto nodata; 1402 } 1403 1404 retval->chunk_hdr = chunk_hdr; 1405 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr); 1406 1407 /* Determine if the chunk needs to be authenticated */ 1408 if (sctp_auth_send_cid(type, asoc)) 1409 retval->auth = 1; 1410 1411 return retval; 1412 nodata: 1413 return NULL; 1414 } 1415 1416 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 1417 __u8 flags, int paylen, gfp_t gfp) 1418 { 1419 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp); 1420 } 1421 1422 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 1423 __u8 type, __u8 flags, int paylen, 1424 gfp_t gfp) 1425 { 1426 struct sctp_chunk *chunk; 1427 1428 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp); 1429 if (chunk) 1430 sctp_control_set_owner_w(chunk); 1431 1432 return chunk; 1433 } 1434 1435 /* Release the memory occupied by a chunk. */ 1436 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1437 { 1438 BUG_ON(!list_empty(&chunk->list)); 1439 list_del_init(&chunk->transmitted_list); 1440 1441 consume_skb(chunk->skb); 1442 consume_skb(chunk->auth_chunk); 1443 1444 SCTP_DBG_OBJCNT_DEC(chunk); 1445 kmem_cache_free(sctp_chunk_cachep, chunk); 1446 } 1447 1448 /* Possibly, free the chunk. */ 1449 void sctp_chunk_free(struct sctp_chunk *chunk) 1450 { 1451 /* Release our reference on the message tracker. */ 1452 if (chunk->msg) 1453 sctp_datamsg_put(chunk->msg); 1454 1455 sctp_chunk_put(chunk); 1456 } 1457 1458 /* Grab a reference to the chunk. */ 1459 void sctp_chunk_hold(struct sctp_chunk *ch) 1460 { 1461 refcount_inc(&ch->refcnt); 1462 } 1463 1464 /* Release a reference to the chunk. */ 1465 void sctp_chunk_put(struct sctp_chunk *ch) 1466 { 1467 if (refcount_dec_and_test(&ch->refcnt)) 1468 sctp_chunk_destroy(ch); 1469 } 1470 1471 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1472 * enough. 1473 */ 1474 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1475 { 1476 void *target; 1477 int chunklen = ntohs(chunk->chunk_hdr->length); 1478 int padlen = SCTP_PAD4(chunklen) - chunklen; 1479 1480 skb_put_zero(chunk->skb, padlen); 1481 target = skb_put_data(chunk->skb, data, len); 1482 1483 /* Adjust the chunk length field. */ 1484 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1485 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1486 1487 return target; 1488 } 1489 1490 /* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient 1491 * space in the chunk 1492 */ 1493 static void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk, 1494 int len, const void *data) 1495 { 1496 if (skb_tailroom(chunk->skb) >= len) 1497 return sctp_addto_chunk(chunk, len, data); 1498 else 1499 return NULL; 1500 } 1501 1502 /* Append bytes from user space to the end of a chunk. Will panic if 1503 * chunk is not big enough. 1504 * Returns a kernel err value. 1505 */ 1506 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len, 1507 struct iov_iter *from) 1508 { 1509 void *target; 1510 1511 /* Make room in chunk for data. */ 1512 target = skb_put(chunk->skb, len); 1513 1514 /* Copy data (whole iovec) into chunk */ 1515 if (!copy_from_iter_full(target, len, from)) 1516 return -EFAULT; 1517 1518 /* Adjust the chunk length field. */ 1519 chunk->chunk_hdr->length = 1520 htons(ntohs(chunk->chunk_hdr->length) + len); 1521 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1522 1523 return 0; 1524 } 1525 1526 /* Helper function to assign a TSN if needed. This assumes that both 1527 * the data_hdr and association have already been assigned. 1528 */ 1529 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1530 { 1531 struct sctp_datamsg *msg; 1532 struct sctp_chunk *lchunk; 1533 struct sctp_stream *stream; 1534 __u16 ssn; 1535 __u16 sid; 1536 1537 if (chunk->has_ssn) 1538 return; 1539 1540 /* All fragments will be on the same stream */ 1541 sid = ntohs(chunk->subh.data_hdr->stream); 1542 stream = &chunk->asoc->stream; 1543 1544 /* Now assign the sequence number to the entire message. 1545 * All fragments must have the same stream sequence number. 1546 */ 1547 msg = chunk->msg; 1548 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1549 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1550 ssn = 0; 1551 } else { 1552 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1553 ssn = sctp_ssn_next(stream, out, sid); 1554 else 1555 ssn = sctp_ssn_peek(stream, out, sid); 1556 } 1557 1558 lchunk->subh.data_hdr->ssn = htons(ssn); 1559 lchunk->has_ssn = 1; 1560 } 1561 } 1562 1563 /* Helper function to assign a TSN if needed. This assumes that both 1564 * the data_hdr and association have already been assigned. 1565 */ 1566 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1567 { 1568 if (!chunk->has_tsn) { 1569 /* This is the last possible instant to 1570 * assign a TSN. 1571 */ 1572 chunk->subh.data_hdr->tsn = 1573 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1574 chunk->has_tsn = 1; 1575 } 1576 } 1577 1578 /* Create a CLOSED association to use with an incoming packet. */ 1579 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1580 struct sctp_chunk *chunk, 1581 gfp_t gfp) 1582 { 1583 struct sctp_association *asoc; 1584 struct sk_buff *skb; 1585 sctp_scope_t scope; 1586 1587 /* Create the bare association. */ 1588 scope = sctp_scope(sctp_source(chunk)); 1589 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1590 if (!asoc) 1591 goto nodata; 1592 asoc->temp = 1; 1593 skb = chunk->skb; 1594 /* Create an entry for the source address of the packet. */ 1595 SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1); 1596 1597 nodata: 1598 return asoc; 1599 } 1600 1601 /* Build a cookie representing asoc. 1602 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1603 */ 1604 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, 1605 const struct sctp_association *asoc, 1606 const struct sctp_chunk *init_chunk, 1607 int *cookie_len, 1608 const __u8 *raw_addrs, int addrs_len) 1609 { 1610 sctp_cookie_param_t *retval; 1611 struct sctp_signed_cookie *cookie; 1612 int headersize, bodysize; 1613 1614 /* Header size is static data prior to the actual cookie, including 1615 * any padding. 1616 */ 1617 headersize = sizeof(struct sctp_paramhdr) + 1618 (sizeof(struct sctp_signed_cookie) - 1619 sizeof(struct sctp_cookie)); 1620 bodysize = sizeof(struct sctp_cookie) 1621 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1622 1623 /* Pad out the cookie to a multiple to make the signature 1624 * functions simpler to write. 1625 */ 1626 if (bodysize % SCTP_COOKIE_MULTIPLE) 1627 bodysize += SCTP_COOKIE_MULTIPLE 1628 - (bodysize % SCTP_COOKIE_MULTIPLE); 1629 *cookie_len = headersize + bodysize; 1630 1631 /* Clear this memory since we are sending this data structure 1632 * out on the network. 1633 */ 1634 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1635 if (!retval) 1636 goto nodata; 1637 1638 cookie = (struct sctp_signed_cookie *) retval->body; 1639 1640 /* Set up the parameter header. */ 1641 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1642 retval->p.length = htons(*cookie_len); 1643 1644 /* Copy the cookie part of the association itself. */ 1645 cookie->c = asoc->c; 1646 /* Save the raw address list length in the cookie. */ 1647 cookie->c.raw_addr_list_len = addrs_len; 1648 1649 /* Remember PR-SCTP capability. */ 1650 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1651 1652 /* Save adaptation indication in the cookie. */ 1653 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1654 1655 /* Set an expiration time for the cookie. */ 1656 cookie->c.expiration = ktime_add(asoc->cookie_life, 1657 ktime_get_real()); 1658 1659 /* Copy the peer's init packet. */ 1660 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr, 1661 ntohs(init_chunk->chunk_hdr->length)); 1662 1663 /* Copy the raw local address list of the association. */ 1664 memcpy((__u8 *)&cookie->c.peer_init[0] + 1665 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1666 1667 if (sctp_sk(ep->base.sk)->hmac) { 1668 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac); 1669 int err; 1670 1671 /* Sign the message. */ 1672 desc->tfm = sctp_sk(ep->base.sk)->hmac; 1673 desc->flags = 0; 1674 1675 err = crypto_shash_setkey(desc->tfm, ep->secret_key, 1676 sizeof(ep->secret_key)) ?: 1677 crypto_shash_digest(desc, (u8 *)&cookie->c, bodysize, 1678 cookie->signature); 1679 shash_desc_zero(desc); 1680 if (err) 1681 goto free_cookie; 1682 } 1683 1684 return retval; 1685 1686 free_cookie: 1687 kfree(retval); 1688 nodata: 1689 *cookie_len = 0; 1690 return NULL; 1691 } 1692 1693 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1694 struct sctp_association *sctp_unpack_cookie( 1695 const struct sctp_endpoint *ep, 1696 const struct sctp_association *asoc, 1697 struct sctp_chunk *chunk, gfp_t gfp, 1698 int *error, struct sctp_chunk **errp) 1699 { 1700 struct sctp_association *retval = NULL; 1701 struct sctp_signed_cookie *cookie; 1702 struct sctp_cookie *bear_cookie; 1703 int headersize, bodysize, fixed_size; 1704 __u8 *digest = ep->digest; 1705 unsigned int len; 1706 sctp_scope_t scope; 1707 struct sk_buff *skb = chunk->skb; 1708 ktime_t kt; 1709 1710 /* Header size is static data prior to the actual cookie, including 1711 * any padding. 1712 */ 1713 headersize = sizeof(struct sctp_chunkhdr) + 1714 (sizeof(struct sctp_signed_cookie) - 1715 sizeof(struct sctp_cookie)); 1716 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1717 fixed_size = headersize + sizeof(struct sctp_cookie); 1718 1719 /* Verify that the chunk looks like it even has a cookie. 1720 * There must be enough room for our cookie and our peer's 1721 * INIT chunk. 1722 */ 1723 len = ntohs(chunk->chunk_hdr->length); 1724 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1725 goto malformed; 1726 1727 /* Verify that the cookie has been padded out. */ 1728 if (bodysize % SCTP_COOKIE_MULTIPLE) 1729 goto malformed; 1730 1731 /* Process the cookie. */ 1732 cookie = chunk->subh.cookie_hdr; 1733 bear_cookie = &cookie->c; 1734 1735 if (!sctp_sk(ep->base.sk)->hmac) 1736 goto no_hmac; 1737 1738 /* Check the signature. */ 1739 { 1740 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac); 1741 int err; 1742 1743 desc->tfm = sctp_sk(ep->base.sk)->hmac; 1744 desc->flags = 0; 1745 1746 err = crypto_shash_setkey(desc->tfm, ep->secret_key, 1747 sizeof(ep->secret_key)) ?: 1748 crypto_shash_digest(desc, (u8 *)bear_cookie, bodysize, 1749 digest); 1750 shash_desc_zero(desc); 1751 1752 if (err) { 1753 *error = -SCTP_IERROR_NOMEM; 1754 goto fail; 1755 } 1756 } 1757 1758 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1759 *error = -SCTP_IERROR_BAD_SIG; 1760 goto fail; 1761 } 1762 1763 no_hmac: 1764 /* IG Section 2.35.2: 1765 * 3) Compare the port numbers and the verification tag contained 1766 * within the COOKIE ECHO chunk to the actual port numbers and the 1767 * verification tag within the SCTP common header of the received 1768 * packet. If these values do not match the packet MUST be silently 1769 * discarded, 1770 */ 1771 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1772 *error = -SCTP_IERROR_BAD_TAG; 1773 goto fail; 1774 } 1775 1776 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1777 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1778 *error = -SCTP_IERROR_BAD_PORTS; 1779 goto fail; 1780 } 1781 1782 /* Check to see if the cookie is stale. If there is already 1783 * an association, there is no need to check cookie's expiration 1784 * for init collision case of lost COOKIE ACK. 1785 * If skb has been timestamped, then use the stamp, otherwise 1786 * use current time. This introduces a small possibility that 1787 * that a cookie may be considered expired, but his would only slow 1788 * down the new association establishment instead of every packet. 1789 */ 1790 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1791 kt = skb_get_ktime(skb); 1792 else 1793 kt = ktime_get_real(); 1794 1795 if (!asoc && ktime_before(bear_cookie->expiration, kt)) { 1796 /* 1797 * Section 3.3.10.3 Stale Cookie Error (3) 1798 * 1799 * Cause of error 1800 * --------------- 1801 * Stale Cookie Error: Indicates the receipt of a valid State 1802 * Cookie that has expired. 1803 */ 1804 len = ntohs(chunk->chunk_hdr->length); 1805 *errp = sctp_make_op_error_space(asoc, chunk, len); 1806 if (*errp) { 1807 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); 1808 __be32 n = htonl(usecs); 1809 1810 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE, 1811 sizeof(n)); 1812 sctp_addto_chunk(*errp, sizeof(n), &n); 1813 *error = -SCTP_IERROR_STALE_COOKIE; 1814 } else 1815 *error = -SCTP_IERROR_NOMEM; 1816 1817 goto fail; 1818 } 1819 1820 /* Make a new base association. */ 1821 scope = sctp_scope(sctp_source(chunk)); 1822 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1823 if (!retval) { 1824 *error = -SCTP_IERROR_NOMEM; 1825 goto fail; 1826 } 1827 1828 /* Set up our peer's port number. */ 1829 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1830 1831 /* Populate the association from the cookie. */ 1832 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1833 1834 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1835 GFP_ATOMIC) < 0) { 1836 *error = -SCTP_IERROR_NOMEM; 1837 goto fail; 1838 } 1839 1840 /* Also, add the destination address. */ 1841 if (list_empty(&retval->base.bind_addr.address_list)) { 1842 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1843 sizeof(chunk->dest), SCTP_ADDR_SRC, 1844 GFP_ATOMIC); 1845 } 1846 1847 retval->next_tsn = retval->c.initial_tsn; 1848 retval->ctsn_ack_point = retval->next_tsn - 1; 1849 retval->addip_serial = retval->c.initial_tsn; 1850 retval->strreset_outseq = retval->c.initial_tsn; 1851 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1852 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1853 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1854 1855 /* The INIT stuff will be done by the side effects. */ 1856 return retval; 1857 1858 fail: 1859 if (retval) 1860 sctp_association_free(retval); 1861 1862 return NULL; 1863 1864 malformed: 1865 /* Yikes! The packet is either corrupt or deliberately 1866 * malformed. 1867 */ 1868 *error = -SCTP_IERROR_MALFORMED; 1869 goto fail; 1870 } 1871 1872 /******************************************************************** 1873 * 3rd Level Abstractions 1874 ********************************************************************/ 1875 1876 struct __sctp_missing { 1877 __be32 num_missing; 1878 __be16 type; 1879 } __packed; 1880 1881 /* 1882 * Report a missing mandatory parameter. 1883 */ 1884 static int sctp_process_missing_param(const struct sctp_association *asoc, 1885 enum sctp_param paramtype, 1886 struct sctp_chunk *chunk, 1887 struct sctp_chunk **errp) 1888 { 1889 struct __sctp_missing report; 1890 __u16 len; 1891 1892 len = SCTP_PAD4(sizeof(report)); 1893 1894 /* Make an ERROR chunk, preparing enough room for 1895 * returning multiple unknown parameters. 1896 */ 1897 if (!*errp) 1898 *errp = sctp_make_op_error_space(asoc, chunk, len); 1899 1900 if (*errp) { 1901 report.num_missing = htonl(1); 1902 report.type = paramtype; 1903 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1904 sizeof(report)); 1905 sctp_addto_chunk(*errp, sizeof(report), &report); 1906 } 1907 1908 /* Stop processing this chunk. */ 1909 return 0; 1910 } 1911 1912 /* Report an Invalid Mandatory Parameter. */ 1913 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1914 struct sctp_chunk *chunk, 1915 struct sctp_chunk **errp) 1916 { 1917 /* Invalid Mandatory Parameter Error has no payload. */ 1918 1919 if (!*errp) 1920 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1921 1922 if (*errp) 1923 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1924 1925 /* Stop processing this chunk. */ 1926 return 0; 1927 } 1928 1929 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1930 struct sctp_paramhdr *param, 1931 const struct sctp_chunk *chunk, 1932 struct sctp_chunk **errp) 1933 { 1934 /* This is a fatal error. Any accumulated non-fatal errors are 1935 * not reported. 1936 */ 1937 if (*errp) 1938 sctp_chunk_free(*errp); 1939 1940 /* Create an error chunk and fill it in with our payload. */ 1941 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1942 1943 return 0; 1944 } 1945 1946 1947 /* Do not attempt to handle the HOST_NAME parm. However, do 1948 * send back an indicator to the peer. 1949 */ 1950 static int sctp_process_hn_param(const struct sctp_association *asoc, 1951 union sctp_params param, 1952 struct sctp_chunk *chunk, 1953 struct sctp_chunk **errp) 1954 { 1955 __u16 len = ntohs(param.p->length); 1956 1957 /* Processing of the HOST_NAME parameter will generate an 1958 * ABORT. If we've accumulated any non-fatal errors, they 1959 * would be unrecognized parameters and we should not include 1960 * them in the ABORT. 1961 */ 1962 if (*errp) 1963 sctp_chunk_free(*errp); 1964 1965 *errp = sctp_make_op_error_space(asoc, chunk, len); 1966 1967 if (*errp) { 1968 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len); 1969 sctp_addto_chunk(*errp, len, param.v); 1970 } 1971 1972 /* Stop processing this chunk. */ 1973 return 0; 1974 } 1975 1976 static int sctp_verify_ext_param(struct net *net, union sctp_params param) 1977 { 1978 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 1979 int have_auth = 0; 1980 int have_asconf = 0; 1981 int i; 1982 1983 for (i = 0; i < num_ext; i++) { 1984 switch (param.ext->chunks[i]) { 1985 case SCTP_CID_AUTH: 1986 have_auth = 1; 1987 break; 1988 case SCTP_CID_ASCONF: 1989 case SCTP_CID_ASCONF_ACK: 1990 have_asconf = 1; 1991 break; 1992 } 1993 } 1994 1995 /* ADD-IP Security: The draft requires us to ABORT or ignore the 1996 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 1997 * only if ADD-IP is turned on and we are not backward-compatible 1998 * mode. 1999 */ 2000 if (net->sctp.addip_noauth) 2001 return 1; 2002 2003 if (net->sctp.addip_enable && !have_auth && have_asconf) 2004 return 0; 2005 2006 return 1; 2007 } 2008 2009 static void sctp_process_ext_param(struct sctp_association *asoc, 2010 union sctp_params param) 2011 { 2012 struct net *net = sock_net(asoc->base.sk); 2013 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2014 int i; 2015 2016 for (i = 0; i < num_ext; i++) { 2017 switch (param.ext->chunks[i]) { 2018 case SCTP_CID_RECONF: 2019 if (asoc->reconf_enable && 2020 !asoc->peer.reconf_capable) 2021 asoc->peer.reconf_capable = 1; 2022 break; 2023 case SCTP_CID_FWD_TSN: 2024 if (asoc->prsctp_enable && !asoc->peer.prsctp_capable) 2025 asoc->peer.prsctp_capable = 1; 2026 break; 2027 case SCTP_CID_AUTH: 2028 /* if the peer reports AUTH, assume that he 2029 * supports AUTH. 2030 */ 2031 if (asoc->ep->auth_enable) 2032 asoc->peer.auth_capable = 1; 2033 break; 2034 case SCTP_CID_ASCONF: 2035 case SCTP_CID_ASCONF_ACK: 2036 if (net->sctp.addip_enable) 2037 asoc->peer.asconf_capable = 1; 2038 break; 2039 default: 2040 break; 2041 } 2042 } 2043 } 2044 2045 /* RFC 3.2.1 & the Implementers Guide 2.2. 2046 * 2047 * The Parameter Types are encoded such that the 2048 * highest-order two bits specify the action that must be 2049 * taken if the processing endpoint does not recognize the 2050 * Parameter Type. 2051 * 2052 * 00 - Stop processing this parameter; do not process any further 2053 * parameters within this chunk 2054 * 2055 * 01 - Stop processing this parameter, do not process any further 2056 * parameters within this chunk, and report the unrecognized 2057 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2058 * 2059 * 10 - Skip this parameter and continue processing. 2060 * 2061 * 11 - Skip this parameter and continue processing but 2062 * report the unrecognized parameter in an 2063 * 'Unrecognized Parameter' ERROR chunk. 2064 * 2065 * Return value: 2066 * SCTP_IERROR_NO_ERROR - continue with the chunk 2067 * SCTP_IERROR_ERROR - stop and report an error. 2068 * SCTP_IERROR_NOMEME - out of memory. 2069 */ 2070 static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc, 2071 union sctp_params param, 2072 struct sctp_chunk *chunk, 2073 struct sctp_chunk **errp) 2074 { 2075 int retval = SCTP_IERROR_NO_ERROR; 2076 2077 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2078 case SCTP_PARAM_ACTION_DISCARD: 2079 retval = SCTP_IERROR_ERROR; 2080 break; 2081 case SCTP_PARAM_ACTION_SKIP: 2082 break; 2083 case SCTP_PARAM_ACTION_DISCARD_ERR: 2084 retval = SCTP_IERROR_ERROR; 2085 /* Fall through */ 2086 case SCTP_PARAM_ACTION_SKIP_ERR: 2087 /* Make an ERROR chunk, preparing enough room for 2088 * returning multiple unknown parameters. 2089 */ 2090 if (NULL == *errp) 2091 *errp = sctp_make_op_error_fixed(asoc, chunk); 2092 2093 if (*errp) { 2094 if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2095 SCTP_PAD4(ntohs(param.p->length)))) 2096 sctp_addto_chunk_fixed(*errp, 2097 SCTP_PAD4(ntohs(param.p->length)), 2098 param.v); 2099 } else { 2100 /* If there is no memory for generating the ERROR 2101 * report as specified, an ABORT will be triggered 2102 * to the peer and the association won't be 2103 * established. 2104 */ 2105 retval = SCTP_IERROR_NOMEM; 2106 } 2107 break; 2108 default: 2109 break; 2110 } 2111 2112 return retval; 2113 } 2114 2115 /* Verify variable length parameters 2116 * Return values: 2117 * SCTP_IERROR_ABORT - trigger an ABORT 2118 * SCTP_IERROR_NOMEM - out of memory (abort) 2119 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2120 * SCTP_IERROR_NO_ERROR - continue with the chunk 2121 */ 2122 static sctp_ierror_t sctp_verify_param(struct net *net, 2123 const struct sctp_endpoint *ep, 2124 const struct sctp_association *asoc, 2125 union sctp_params param, 2126 enum sctp_cid cid, 2127 struct sctp_chunk *chunk, 2128 struct sctp_chunk **err_chunk) 2129 { 2130 struct sctp_hmac_algo_param *hmacs; 2131 int retval = SCTP_IERROR_NO_ERROR; 2132 __u16 n_elt, id = 0; 2133 int i; 2134 2135 /* FIXME - This routine is not looking at each parameter per the 2136 * chunk type, i.e., unrecognized parameters should be further 2137 * identified based on the chunk id. 2138 */ 2139 2140 switch (param.p->type) { 2141 case SCTP_PARAM_IPV4_ADDRESS: 2142 case SCTP_PARAM_IPV6_ADDRESS: 2143 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2144 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2145 case SCTP_PARAM_STATE_COOKIE: 2146 case SCTP_PARAM_HEARTBEAT_INFO: 2147 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2148 case SCTP_PARAM_ECN_CAPABLE: 2149 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2150 break; 2151 2152 case SCTP_PARAM_SUPPORTED_EXT: 2153 if (!sctp_verify_ext_param(net, param)) 2154 return SCTP_IERROR_ABORT; 2155 break; 2156 2157 case SCTP_PARAM_SET_PRIMARY: 2158 if (net->sctp.addip_enable) 2159 break; 2160 goto fallthrough; 2161 2162 case SCTP_PARAM_HOST_NAME_ADDRESS: 2163 /* Tell the peer, we won't support this param. */ 2164 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2165 retval = SCTP_IERROR_ABORT; 2166 break; 2167 2168 case SCTP_PARAM_FWD_TSN_SUPPORT: 2169 if (ep->prsctp_enable) 2170 break; 2171 goto fallthrough; 2172 2173 case SCTP_PARAM_RANDOM: 2174 if (!ep->auth_enable) 2175 goto fallthrough; 2176 2177 /* SCTP-AUTH: Secion 6.1 2178 * If the random number is not 32 byte long the association 2179 * MUST be aborted. The ABORT chunk SHOULD contain the error 2180 * cause 'Protocol Violation'. 2181 */ 2182 if (SCTP_AUTH_RANDOM_LENGTH != 2183 ntohs(param.p->length) - sizeof(struct sctp_paramhdr)) { 2184 sctp_process_inv_paramlength(asoc, param.p, 2185 chunk, err_chunk); 2186 retval = SCTP_IERROR_ABORT; 2187 } 2188 break; 2189 2190 case SCTP_PARAM_CHUNKS: 2191 if (!ep->auth_enable) 2192 goto fallthrough; 2193 2194 /* SCTP-AUTH: Section 3.2 2195 * The CHUNKS parameter MUST be included once in the INIT or 2196 * INIT-ACK chunk if the sender wants to receive authenticated 2197 * chunks. Its maximum length is 260 bytes. 2198 */ 2199 if (260 < ntohs(param.p->length)) { 2200 sctp_process_inv_paramlength(asoc, param.p, 2201 chunk, err_chunk); 2202 retval = SCTP_IERROR_ABORT; 2203 } 2204 break; 2205 2206 case SCTP_PARAM_HMAC_ALGO: 2207 if (!ep->auth_enable) 2208 goto fallthrough; 2209 2210 hmacs = (struct sctp_hmac_algo_param *)param.p; 2211 n_elt = (ntohs(param.p->length) - 2212 sizeof(struct sctp_paramhdr)) >> 1; 2213 2214 /* SCTP-AUTH: Section 6.1 2215 * The HMAC algorithm based on SHA-1 MUST be supported and 2216 * included in the HMAC-ALGO parameter. 2217 */ 2218 for (i = 0; i < n_elt; i++) { 2219 id = ntohs(hmacs->hmac_ids[i]); 2220 2221 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2222 break; 2223 } 2224 2225 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2226 sctp_process_inv_paramlength(asoc, param.p, chunk, 2227 err_chunk); 2228 retval = SCTP_IERROR_ABORT; 2229 } 2230 break; 2231 fallthrough: 2232 default: 2233 pr_debug("%s: unrecognized param:%d for chunk:%d\n", 2234 __func__, ntohs(param.p->type), cid); 2235 2236 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2237 break; 2238 } 2239 return retval; 2240 } 2241 2242 /* Verify the INIT packet before we process it. */ 2243 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 2244 const struct sctp_association *asoc, enum sctp_cid cid, 2245 struct sctp_init_chunk *peer_init, 2246 struct sctp_chunk *chunk, struct sctp_chunk **errp) 2247 { 2248 union sctp_params param; 2249 bool has_cookie = false; 2250 int result; 2251 2252 /* Check for missing mandatory parameters. Note: Initial TSN is 2253 * also mandatory, but is not checked here since the valid range 2254 * is 0..2**32-1. RFC4960, section 3.3.3. 2255 */ 2256 if (peer_init->init_hdr.num_outbound_streams == 0 || 2257 peer_init->init_hdr.num_inbound_streams == 0 || 2258 peer_init->init_hdr.init_tag == 0 || 2259 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) 2260 return sctp_process_inv_mandatory(asoc, chunk, errp); 2261 2262 sctp_walk_params(param, peer_init, init_hdr.params) { 2263 if (param.p->type == SCTP_PARAM_STATE_COOKIE) 2264 has_cookie = true; 2265 } 2266 2267 /* There is a possibility that a parameter length was bad and 2268 * in that case we would have stoped walking the parameters. 2269 * The current param.p would point at the bad one. 2270 * Current consensus on the mailing list is to generate a PROTOCOL 2271 * VIOLATION error. We build the ERROR chunk here and let the normal 2272 * error handling code build and send the packet. 2273 */ 2274 if (param.v != (void *)chunk->chunk_end) 2275 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2276 2277 /* The only missing mandatory param possible today is 2278 * the state cookie for an INIT-ACK chunk. 2279 */ 2280 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2281 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2282 chunk, errp); 2283 2284 /* Verify all the variable length parameters */ 2285 sctp_walk_params(param, peer_init, init_hdr.params) { 2286 result = sctp_verify_param(net, ep, asoc, param, cid, 2287 chunk, errp); 2288 switch (result) { 2289 case SCTP_IERROR_ABORT: 2290 case SCTP_IERROR_NOMEM: 2291 return 0; 2292 case SCTP_IERROR_ERROR: 2293 return 1; 2294 case SCTP_IERROR_NO_ERROR: 2295 default: 2296 break; 2297 } 2298 2299 } /* for (loop through all parameters) */ 2300 2301 return 1; 2302 } 2303 2304 /* Unpack the parameters in an INIT packet into an association. 2305 * Returns 0 on failure, else success. 2306 * FIXME: This is an association method. 2307 */ 2308 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2309 const union sctp_addr *peer_addr, 2310 struct sctp_init_chunk *peer_init, gfp_t gfp) 2311 { 2312 struct net *net = sock_net(asoc->base.sk); 2313 union sctp_params param; 2314 struct sctp_transport *transport; 2315 struct list_head *pos, *temp; 2316 struct sctp_af *af; 2317 union sctp_addr addr; 2318 char *cookie; 2319 int src_match = 0; 2320 2321 /* We must include the address that the INIT packet came from. 2322 * This is the only address that matters for an INIT packet. 2323 * When processing a COOKIE ECHO, we retrieve the from address 2324 * of the INIT from the cookie. 2325 */ 2326 2327 /* This implementation defaults to making the first transport 2328 * added as the primary transport. The source address seems to 2329 * be a a better choice than any of the embedded addresses. 2330 */ 2331 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2332 goto nomem; 2333 2334 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2335 src_match = 1; 2336 2337 /* Process the initialization parameters. */ 2338 sctp_walk_params(param, peer_init, init_hdr.params) { 2339 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2340 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2341 af = sctp_get_af_specific(param_type2af(param.p->type)); 2342 af->from_addr_param(&addr, param.addr, 2343 chunk->sctp_hdr->source, 0); 2344 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2345 src_match = 1; 2346 } 2347 2348 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2349 goto clean_up; 2350 } 2351 2352 /* source address of chunk may not match any valid address */ 2353 if (!src_match) 2354 goto clean_up; 2355 2356 /* AUTH: After processing the parameters, make sure that we 2357 * have all the required info to potentially do authentications. 2358 */ 2359 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2360 !asoc->peer.peer_hmacs)) 2361 asoc->peer.auth_capable = 0; 2362 2363 /* In a non-backward compatible mode, if the peer claims 2364 * support for ADD-IP but not AUTH, the ADD-IP spec states 2365 * that we MUST ABORT the association. Section 6. The section 2366 * also give us an option to silently ignore the packet, which 2367 * is what we'll do here. 2368 */ 2369 if (!net->sctp.addip_noauth && 2370 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2371 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2372 SCTP_PARAM_DEL_IP | 2373 SCTP_PARAM_SET_PRIMARY); 2374 asoc->peer.asconf_capable = 0; 2375 goto clean_up; 2376 } 2377 2378 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2379 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2380 transport = list_entry(pos, struct sctp_transport, transports); 2381 if (transport->state == SCTP_UNKNOWN) { 2382 sctp_assoc_rm_peer(asoc, transport); 2383 } 2384 } 2385 2386 /* The fixed INIT headers are always in network byte 2387 * order. 2388 */ 2389 asoc->peer.i.init_tag = 2390 ntohl(peer_init->init_hdr.init_tag); 2391 asoc->peer.i.a_rwnd = 2392 ntohl(peer_init->init_hdr.a_rwnd); 2393 asoc->peer.i.num_outbound_streams = 2394 ntohs(peer_init->init_hdr.num_outbound_streams); 2395 asoc->peer.i.num_inbound_streams = 2396 ntohs(peer_init->init_hdr.num_inbound_streams); 2397 asoc->peer.i.initial_tsn = 2398 ntohl(peer_init->init_hdr.initial_tsn); 2399 2400 asoc->strreset_inseq = asoc->peer.i.initial_tsn; 2401 2402 /* Apply the upper bounds for output streams based on peer's 2403 * number of inbound streams. 2404 */ 2405 if (asoc->c.sinit_num_ostreams > 2406 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2407 asoc->c.sinit_num_ostreams = 2408 ntohs(peer_init->init_hdr.num_inbound_streams); 2409 } 2410 2411 if (asoc->c.sinit_max_instreams > 2412 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2413 asoc->c.sinit_max_instreams = 2414 ntohs(peer_init->init_hdr.num_outbound_streams); 2415 } 2416 2417 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2418 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2419 2420 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2421 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2422 2423 /* Copy cookie in case we need to resend COOKIE-ECHO. */ 2424 cookie = asoc->peer.cookie; 2425 if (cookie) { 2426 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp); 2427 if (!asoc->peer.cookie) 2428 goto clean_up; 2429 } 2430 2431 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2432 * high (for example, implementations MAY use the size of the receiver 2433 * advertised window). 2434 */ 2435 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2436 transports) { 2437 transport->ssthresh = asoc->peer.i.a_rwnd; 2438 } 2439 2440 /* Set up the TSN tracking pieces. */ 2441 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2442 asoc->peer.i.initial_tsn, gfp)) 2443 goto clean_up; 2444 2445 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2446 * 2447 * The stream sequence number in all the streams shall start 2448 * from 0 when the association is established. Also, when the 2449 * stream sequence number reaches the value 65535 the next 2450 * stream sequence number shall be set to 0. 2451 */ 2452 2453 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams, 2454 asoc->c.sinit_max_instreams, gfp)) 2455 goto clean_up; 2456 2457 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp)) 2458 goto clean_up; 2459 2460 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2461 * 2462 * When an endpoint has an ASCONF signaled change to be sent to the 2463 * remote endpoint it should do the following: 2464 * ... 2465 * A2) A serial number should be assigned to the Chunk. The serial 2466 * number should be a monotonically increasing number. All serial 2467 * numbers are defined to be initialized at the start of the 2468 * association to the same value as the Initial TSN. 2469 */ 2470 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2471 return 1; 2472 2473 clean_up: 2474 /* Release the transport structures. */ 2475 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2476 transport = list_entry(pos, struct sctp_transport, transports); 2477 if (transport->state != SCTP_ACTIVE) 2478 sctp_assoc_rm_peer(asoc, transport); 2479 } 2480 2481 nomem: 2482 return 0; 2483 } 2484 2485 2486 /* Update asoc with the option described in param. 2487 * 2488 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2489 * 2490 * asoc is the association to update. 2491 * param is the variable length parameter to use for update. 2492 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2493 * If the current packet is an INIT we want to minimize the amount of 2494 * work we do. In particular, we should not build transport 2495 * structures for the addresses. 2496 */ 2497 static int sctp_process_param(struct sctp_association *asoc, 2498 union sctp_params param, 2499 const union sctp_addr *peer_addr, 2500 gfp_t gfp) 2501 { 2502 struct net *net = sock_net(asoc->base.sk); 2503 union sctp_addr addr; 2504 int i; 2505 __u16 sat; 2506 int retval = 1; 2507 sctp_scope_t scope; 2508 u32 stale; 2509 struct sctp_af *af; 2510 union sctp_addr_param *addr_param; 2511 struct sctp_transport *t; 2512 struct sctp_endpoint *ep = asoc->ep; 2513 2514 /* We maintain all INIT parameters in network byte order all the 2515 * time. This allows us to not worry about whether the parameters 2516 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2517 */ 2518 switch (param.p->type) { 2519 case SCTP_PARAM_IPV6_ADDRESS: 2520 if (PF_INET6 != asoc->base.sk->sk_family) 2521 break; 2522 goto do_addr_param; 2523 2524 case SCTP_PARAM_IPV4_ADDRESS: 2525 /* v4 addresses are not allowed on v6-only socket */ 2526 if (ipv6_only_sock(asoc->base.sk)) 2527 break; 2528 do_addr_param: 2529 af = sctp_get_af_specific(param_type2af(param.p->type)); 2530 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); 2531 scope = sctp_scope(peer_addr); 2532 if (sctp_in_scope(net, &addr, scope)) 2533 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2534 return 0; 2535 break; 2536 2537 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2538 if (!net->sctp.cookie_preserve_enable) 2539 break; 2540 2541 stale = ntohl(param.life->lifespan_increment); 2542 2543 /* Suggested Cookie Life span increment's unit is msec, 2544 * (1/1000sec). 2545 */ 2546 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale); 2547 break; 2548 2549 case SCTP_PARAM_HOST_NAME_ADDRESS: 2550 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__); 2551 break; 2552 2553 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2554 /* Turn off the default values first so we'll know which 2555 * ones are really set by the peer. 2556 */ 2557 asoc->peer.ipv4_address = 0; 2558 asoc->peer.ipv6_address = 0; 2559 2560 /* Assume that peer supports the address family 2561 * by which it sends a packet. 2562 */ 2563 if (peer_addr->sa.sa_family == AF_INET6) 2564 asoc->peer.ipv6_address = 1; 2565 else if (peer_addr->sa.sa_family == AF_INET) 2566 asoc->peer.ipv4_address = 1; 2567 2568 /* Cycle through address types; avoid divide by 0. */ 2569 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2570 if (sat) 2571 sat /= sizeof(__u16); 2572 2573 for (i = 0; i < sat; ++i) { 2574 switch (param.sat->types[i]) { 2575 case SCTP_PARAM_IPV4_ADDRESS: 2576 asoc->peer.ipv4_address = 1; 2577 break; 2578 2579 case SCTP_PARAM_IPV6_ADDRESS: 2580 if (PF_INET6 == asoc->base.sk->sk_family) 2581 asoc->peer.ipv6_address = 1; 2582 break; 2583 2584 case SCTP_PARAM_HOST_NAME_ADDRESS: 2585 asoc->peer.hostname_address = 1; 2586 break; 2587 2588 default: /* Just ignore anything else. */ 2589 break; 2590 } 2591 } 2592 break; 2593 2594 case SCTP_PARAM_STATE_COOKIE: 2595 asoc->peer.cookie_len = 2596 ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2597 asoc->peer.cookie = param.cookie->body; 2598 break; 2599 2600 case SCTP_PARAM_HEARTBEAT_INFO: 2601 /* Would be odd to receive, but it causes no problems. */ 2602 break; 2603 2604 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2605 /* Rejected during verify stage. */ 2606 break; 2607 2608 case SCTP_PARAM_ECN_CAPABLE: 2609 asoc->peer.ecn_capable = 1; 2610 break; 2611 2612 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2613 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2614 break; 2615 2616 case SCTP_PARAM_SET_PRIMARY: 2617 if (!net->sctp.addip_enable) 2618 goto fall_through; 2619 2620 addr_param = param.v + sizeof(sctp_addip_param_t); 2621 2622 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 2623 if (af == NULL) 2624 break; 2625 2626 af->from_addr_param(&addr, addr_param, 2627 htons(asoc->peer.port), 0); 2628 2629 /* if the address is invalid, we can't process it. 2630 * XXX: see spec for what to do. 2631 */ 2632 if (!af->addr_valid(&addr, NULL, NULL)) 2633 break; 2634 2635 t = sctp_assoc_lookup_paddr(asoc, &addr); 2636 if (!t) 2637 break; 2638 2639 sctp_assoc_set_primary(asoc, t); 2640 break; 2641 2642 case SCTP_PARAM_SUPPORTED_EXT: 2643 sctp_process_ext_param(asoc, param); 2644 break; 2645 2646 case SCTP_PARAM_FWD_TSN_SUPPORT: 2647 if (asoc->prsctp_enable) { 2648 asoc->peer.prsctp_capable = 1; 2649 break; 2650 } 2651 /* Fall Through */ 2652 goto fall_through; 2653 2654 case SCTP_PARAM_RANDOM: 2655 if (!ep->auth_enable) 2656 goto fall_through; 2657 2658 /* Save peer's random parameter */ 2659 asoc->peer.peer_random = kmemdup(param.p, 2660 ntohs(param.p->length), gfp); 2661 if (!asoc->peer.peer_random) { 2662 retval = 0; 2663 break; 2664 } 2665 break; 2666 2667 case SCTP_PARAM_HMAC_ALGO: 2668 if (!ep->auth_enable) 2669 goto fall_through; 2670 2671 /* Save peer's HMAC list */ 2672 asoc->peer.peer_hmacs = kmemdup(param.p, 2673 ntohs(param.p->length), gfp); 2674 if (!asoc->peer.peer_hmacs) { 2675 retval = 0; 2676 break; 2677 } 2678 2679 /* Set the default HMAC the peer requested*/ 2680 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2681 break; 2682 2683 case SCTP_PARAM_CHUNKS: 2684 if (!ep->auth_enable) 2685 goto fall_through; 2686 2687 asoc->peer.peer_chunks = kmemdup(param.p, 2688 ntohs(param.p->length), gfp); 2689 if (!asoc->peer.peer_chunks) 2690 retval = 0; 2691 break; 2692 fall_through: 2693 default: 2694 /* Any unrecognized parameters should have been caught 2695 * and handled by sctp_verify_param() which should be 2696 * called prior to this routine. Simply log the error 2697 * here. 2698 */ 2699 pr_debug("%s: ignoring param:%d for association:%p.\n", 2700 __func__, ntohs(param.p->type), asoc); 2701 break; 2702 } 2703 2704 return retval; 2705 } 2706 2707 /* Select a new verification tag. */ 2708 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2709 { 2710 /* I believe that this random number generator complies with RFC1750. 2711 * A tag of 0 is reserved for special cases (e.g. INIT). 2712 */ 2713 __u32 x; 2714 2715 do { 2716 get_random_bytes(&x, sizeof(__u32)); 2717 } while (x == 0); 2718 2719 return x; 2720 } 2721 2722 /* Select an initial TSN to send during startup. */ 2723 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2724 { 2725 __u32 retval; 2726 2727 get_random_bytes(&retval, sizeof(__u32)); 2728 return retval; 2729 } 2730 2731 /* 2732 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2733 * 0 1 2 3 2734 * 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 2735 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2736 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2737 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2738 * | Serial Number | 2739 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2740 * | Address Parameter | 2741 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2742 * | ASCONF Parameter #1 | 2743 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2744 * \ \ 2745 * / .... / 2746 * \ \ 2747 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2748 * | ASCONF Parameter #N | 2749 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2750 * 2751 * Address Parameter and other parameter will not be wrapped in this function 2752 */ 2753 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2754 union sctp_addr *addr, 2755 int vparam_len) 2756 { 2757 sctp_addiphdr_t asconf; 2758 struct sctp_chunk *retval; 2759 int length = sizeof(asconf) + vparam_len; 2760 union sctp_addr_param addrparam; 2761 int addrlen; 2762 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2763 2764 addrlen = af->to_addr_param(addr, &addrparam); 2765 if (!addrlen) 2766 return NULL; 2767 length += addrlen; 2768 2769 /* Create the chunk. */ 2770 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length, 2771 GFP_ATOMIC); 2772 if (!retval) 2773 return NULL; 2774 2775 asconf.serial = htonl(asoc->addip_serial++); 2776 2777 retval->subh.addip_hdr = 2778 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2779 retval->param_hdr.v = 2780 sctp_addto_chunk(retval, addrlen, &addrparam); 2781 2782 return retval; 2783 } 2784 2785 /* ADDIP 2786 * 3.2.1 Add IP Address 2787 * 0 1 2 3 2788 * 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 2789 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2790 * | Type = 0xC001 | Length = Variable | 2791 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2792 * | ASCONF-Request Correlation ID | 2793 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2794 * | Address Parameter | 2795 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2796 * 2797 * 3.2.2 Delete IP Address 2798 * 0 1 2 3 2799 * 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 2800 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2801 * | Type = 0xC002 | Length = Variable | 2802 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2803 * | ASCONF-Request Correlation ID | 2804 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2805 * | Address Parameter | 2806 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2807 * 2808 */ 2809 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2810 union sctp_addr *laddr, 2811 struct sockaddr *addrs, 2812 int addrcnt, 2813 __be16 flags) 2814 { 2815 sctp_addip_param_t param; 2816 struct sctp_chunk *retval; 2817 union sctp_addr_param addr_param; 2818 union sctp_addr *addr; 2819 void *addr_buf; 2820 struct sctp_af *af; 2821 int paramlen = sizeof(param); 2822 int addr_param_len = 0; 2823 int totallen = 0; 2824 int i; 2825 int del_pickup = 0; 2826 2827 /* Get total length of all the address parameters. */ 2828 addr_buf = addrs; 2829 for (i = 0; i < addrcnt; i++) { 2830 addr = addr_buf; 2831 af = sctp_get_af_specific(addr->v4.sin_family); 2832 addr_param_len = af->to_addr_param(addr, &addr_param); 2833 2834 totallen += paramlen; 2835 totallen += addr_param_len; 2836 2837 addr_buf += af->sockaddr_len; 2838 if (asoc->asconf_addr_del_pending && !del_pickup) { 2839 /* reuse the parameter length from the same scope one */ 2840 totallen += paramlen; 2841 totallen += addr_param_len; 2842 del_pickup = 1; 2843 2844 pr_debug("%s: picked same-scope del_pending addr, " 2845 "totallen for all addresses is %d\n", 2846 __func__, totallen); 2847 } 2848 } 2849 2850 /* Create an asconf chunk with the required length. */ 2851 retval = sctp_make_asconf(asoc, laddr, totallen); 2852 if (!retval) 2853 return NULL; 2854 2855 /* Add the address parameters to the asconf chunk. */ 2856 addr_buf = addrs; 2857 for (i = 0; i < addrcnt; i++) { 2858 addr = addr_buf; 2859 af = sctp_get_af_specific(addr->v4.sin_family); 2860 addr_param_len = af->to_addr_param(addr, &addr_param); 2861 param.param_hdr.type = flags; 2862 param.param_hdr.length = htons(paramlen + addr_param_len); 2863 param.crr_id = i; 2864 2865 sctp_addto_chunk(retval, paramlen, ¶m); 2866 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2867 2868 addr_buf += af->sockaddr_len; 2869 } 2870 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2871 addr = asoc->asconf_addr_del_pending; 2872 af = sctp_get_af_specific(addr->v4.sin_family); 2873 addr_param_len = af->to_addr_param(addr, &addr_param); 2874 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2875 param.param_hdr.length = htons(paramlen + addr_param_len); 2876 param.crr_id = i; 2877 2878 sctp_addto_chunk(retval, paramlen, ¶m); 2879 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2880 } 2881 return retval; 2882 } 2883 2884 /* ADDIP 2885 * 3.2.4 Set Primary IP Address 2886 * 0 1 2 3 2887 * 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 2888 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2889 * | Type =0xC004 | Length = Variable | 2890 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2891 * | ASCONF-Request Correlation ID | 2892 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2893 * | Address Parameter | 2894 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2895 * 2896 * Create an ASCONF chunk with Set Primary IP address parameter. 2897 */ 2898 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2899 union sctp_addr *addr) 2900 { 2901 sctp_addip_param_t param; 2902 struct sctp_chunk *retval; 2903 int len = sizeof(param); 2904 union sctp_addr_param addrparam; 2905 int addrlen; 2906 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2907 2908 addrlen = af->to_addr_param(addr, &addrparam); 2909 if (!addrlen) 2910 return NULL; 2911 len += addrlen; 2912 2913 /* Create the chunk and make asconf header. */ 2914 retval = sctp_make_asconf(asoc, addr, len); 2915 if (!retval) 2916 return NULL; 2917 2918 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2919 param.param_hdr.length = htons(len); 2920 param.crr_id = 0; 2921 2922 sctp_addto_chunk(retval, sizeof(param), ¶m); 2923 sctp_addto_chunk(retval, addrlen, &addrparam); 2924 2925 return retval; 2926 } 2927 2928 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2929 * 0 1 2 3 2930 * 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 2931 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2932 * | Type = 0x80 | Chunk Flags | Chunk Length | 2933 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2934 * | Serial Number | 2935 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2936 * | ASCONF Parameter Response#1 | 2937 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2938 * \ \ 2939 * / .... / 2940 * \ \ 2941 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2942 * | ASCONF Parameter Response#N | 2943 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2944 * 2945 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2946 */ 2947 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2948 __u32 serial, int vparam_len) 2949 { 2950 sctp_addiphdr_t asconf; 2951 struct sctp_chunk *retval; 2952 int length = sizeof(asconf) + vparam_len; 2953 2954 /* Create the chunk. */ 2955 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length, 2956 GFP_ATOMIC); 2957 if (!retval) 2958 return NULL; 2959 2960 asconf.serial = htonl(serial); 2961 2962 retval->subh.addip_hdr = 2963 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2964 2965 return retval; 2966 } 2967 2968 /* Add response parameters to an ASCONF_ACK chunk. */ 2969 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2970 __be16 err_code, sctp_addip_param_t *asconf_param) 2971 { 2972 sctp_addip_param_t ack_param; 2973 sctp_errhdr_t err_param; 2974 int asconf_param_len = 0; 2975 int err_param_len = 0; 2976 __be16 response_type; 2977 2978 if (SCTP_ERROR_NO_ERROR == err_code) { 2979 response_type = SCTP_PARAM_SUCCESS_REPORT; 2980 } else { 2981 response_type = SCTP_PARAM_ERR_CAUSE; 2982 err_param_len = sizeof(err_param); 2983 if (asconf_param) 2984 asconf_param_len = 2985 ntohs(asconf_param->param_hdr.length); 2986 } 2987 2988 /* Add Success Indication or Error Cause Indication parameter. */ 2989 ack_param.param_hdr.type = response_type; 2990 ack_param.param_hdr.length = htons(sizeof(ack_param) + 2991 err_param_len + 2992 asconf_param_len); 2993 ack_param.crr_id = crr_id; 2994 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 2995 2996 if (SCTP_ERROR_NO_ERROR == err_code) 2997 return; 2998 2999 /* Add Error Cause parameter. */ 3000 err_param.cause = err_code; 3001 err_param.length = htons(err_param_len + asconf_param_len); 3002 sctp_addto_chunk(chunk, err_param_len, &err_param); 3003 3004 /* Add the failed TLV copied from ASCONF chunk. */ 3005 if (asconf_param) 3006 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 3007 } 3008 3009 /* Process a asconf parameter. */ 3010 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 3011 struct sctp_chunk *asconf, 3012 sctp_addip_param_t *asconf_param) 3013 { 3014 struct sctp_transport *peer; 3015 struct sctp_af *af; 3016 union sctp_addr addr; 3017 union sctp_addr_param *addr_param; 3018 3019 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t); 3020 3021 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 3022 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 3023 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 3024 return SCTP_ERROR_UNKNOWN_PARAM; 3025 3026 switch (addr_param->p.type) { 3027 case SCTP_PARAM_IPV6_ADDRESS: 3028 if (!asoc->peer.ipv6_address) 3029 return SCTP_ERROR_DNS_FAILED; 3030 break; 3031 case SCTP_PARAM_IPV4_ADDRESS: 3032 if (!asoc->peer.ipv4_address) 3033 return SCTP_ERROR_DNS_FAILED; 3034 break; 3035 default: 3036 return SCTP_ERROR_DNS_FAILED; 3037 } 3038 3039 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3040 if (unlikely(!af)) 3041 return SCTP_ERROR_DNS_FAILED; 3042 3043 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); 3044 3045 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3046 * or multicast address. 3047 * (note: wildcard is permitted and requires special handling so 3048 * make sure we check for that) 3049 */ 3050 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3051 return SCTP_ERROR_DNS_FAILED; 3052 3053 switch (asconf_param->param_hdr.type) { 3054 case SCTP_PARAM_ADD_IP: 3055 /* Section 4.2.1: 3056 * If the address 0.0.0.0 or ::0 is provided, the source 3057 * address of the packet MUST be added. 3058 */ 3059 if (af->is_any(&addr)) 3060 memcpy(&addr, &asconf->source, sizeof(addr)); 3061 3062 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3063 * request and does not have the local resources to add this 3064 * new address to the association, it MUST return an Error 3065 * Cause TLV set to the new error code 'Operation Refused 3066 * Due to Resource Shortage'. 3067 */ 3068 3069 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3070 if (!peer) 3071 return SCTP_ERROR_RSRC_LOW; 3072 3073 /* Start the heartbeat timer. */ 3074 sctp_transport_reset_hb_timer(peer); 3075 asoc->new_transport = peer; 3076 break; 3077 case SCTP_PARAM_DEL_IP: 3078 /* ADDIP 4.3 D7) If a request is received to delete the 3079 * last remaining IP address of a peer endpoint, the receiver 3080 * MUST send an Error Cause TLV with the error cause set to the 3081 * new error code 'Request to Delete Last Remaining IP Address'. 3082 */ 3083 if (asoc->peer.transport_count == 1) 3084 return SCTP_ERROR_DEL_LAST_IP; 3085 3086 /* ADDIP 4.3 D8) If a request is received to delete an IP 3087 * address which is also the source address of the IP packet 3088 * which contained the ASCONF chunk, the receiver MUST reject 3089 * this request. To reject the request the receiver MUST send 3090 * an Error Cause TLV set to the new error code 'Request to 3091 * Delete Source IP Address' 3092 */ 3093 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3094 return SCTP_ERROR_DEL_SRC_IP; 3095 3096 /* Section 4.2.2 3097 * If the address 0.0.0.0 or ::0 is provided, all 3098 * addresses of the peer except the source address of the 3099 * packet MUST be deleted. 3100 */ 3101 if (af->is_any(&addr)) { 3102 sctp_assoc_set_primary(asoc, asconf->transport); 3103 sctp_assoc_del_nonprimary_peers(asoc, 3104 asconf->transport); 3105 return SCTP_ERROR_NO_ERROR; 3106 } 3107 3108 /* If the address is not part of the association, the 3109 * ASCONF-ACK with Error Cause Indication Parameter 3110 * which including cause of Unresolvable Address should 3111 * be sent. 3112 */ 3113 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3114 if (!peer) 3115 return SCTP_ERROR_DNS_FAILED; 3116 3117 sctp_assoc_rm_peer(asoc, peer); 3118 break; 3119 case SCTP_PARAM_SET_PRIMARY: 3120 /* ADDIP Section 4.2.4 3121 * If the address 0.0.0.0 or ::0 is provided, the receiver 3122 * MAY mark the source address of the packet as its 3123 * primary. 3124 */ 3125 if (af->is_any(&addr)) 3126 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr)); 3127 3128 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3129 if (!peer) 3130 return SCTP_ERROR_DNS_FAILED; 3131 3132 sctp_assoc_set_primary(asoc, peer); 3133 break; 3134 } 3135 3136 return SCTP_ERROR_NO_ERROR; 3137 } 3138 3139 /* Verify the ASCONF packet before we process it. */ 3140 bool sctp_verify_asconf(const struct sctp_association *asoc, 3141 struct sctp_chunk *chunk, bool addr_param_needed, 3142 struct sctp_paramhdr **errp) 3143 { 3144 sctp_addip_chunk_t *addip = (sctp_addip_chunk_t *) chunk->chunk_hdr; 3145 union sctp_params param; 3146 bool addr_param_seen = false; 3147 3148 sctp_walk_params(param, addip, addip_hdr.params) { 3149 size_t length = ntohs(param.p->length); 3150 3151 *errp = param.p; 3152 switch (param.p->type) { 3153 case SCTP_PARAM_ERR_CAUSE: 3154 break; 3155 case SCTP_PARAM_IPV4_ADDRESS: 3156 if (length != sizeof(sctp_ipv4addr_param_t)) 3157 return false; 3158 /* ensure there is only one addr param and it's in the 3159 * beginning of addip_hdr params, or we reject it. 3160 */ 3161 if (param.v != addip->addip_hdr.params) 3162 return false; 3163 addr_param_seen = true; 3164 break; 3165 case SCTP_PARAM_IPV6_ADDRESS: 3166 if (length != sizeof(sctp_ipv6addr_param_t)) 3167 return false; 3168 if (param.v != addip->addip_hdr.params) 3169 return false; 3170 addr_param_seen = true; 3171 break; 3172 case SCTP_PARAM_ADD_IP: 3173 case SCTP_PARAM_DEL_IP: 3174 case SCTP_PARAM_SET_PRIMARY: 3175 /* In ASCONF chunks, these need to be first. */ 3176 if (addr_param_needed && !addr_param_seen) 3177 return false; 3178 length = ntohs(param.addip->param_hdr.length); 3179 if (length < sizeof(sctp_addip_param_t) + 3180 sizeof(**errp)) 3181 return false; 3182 break; 3183 case SCTP_PARAM_SUCCESS_REPORT: 3184 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3185 if (length != sizeof(sctp_addip_param_t)) 3186 return false; 3187 break; 3188 default: 3189 /* This is unkown to us, reject! */ 3190 return false; 3191 } 3192 } 3193 3194 /* Remaining sanity checks. */ 3195 if (addr_param_needed && !addr_param_seen) 3196 return false; 3197 if (!addr_param_needed && addr_param_seen) 3198 return false; 3199 if (param.v != chunk->chunk_end) 3200 return false; 3201 3202 return true; 3203 } 3204 3205 /* Process an incoming ASCONF chunk with the next expected serial no. and 3206 * return an ASCONF_ACK chunk to be sent in response. 3207 */ 3208 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3209 struct sctp_chunk *asconf) 3210 { 3211 sctp_addip_chunk_t *addip = (sctp_addip_chunk_t *) asconf->chunk_hdr; 3212 bool all_param_pass = true; 3213 union sctp_params param; 3214 sctp_addiphdr_t *hdr; 3215 union sctp_addr_param *addr_param; 3216 struct sctp_chunk *asconf_ack; 3217 __be16 err_code; 3218 int length = 0; 3219 int chunk_len; 3220 __u32 serial; 3221 3222 chunk_len = ntohs(asconf->chunk_hdr->length) - 3223 sizeof(struct sctp_chunkhdr); 3224 hdr = (sctp_addiphdr_t *)asconf->skb->data; 3225 serial = ntohl(hdr->serial); 3226 3227 /* Skip the addiphdr and store a pointer to address parameter. */ 3228 length = sizeof(sctp_addiphdr_t); 3229 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3230 chunk_len -= length; 3231 3232 /* Skip the address parameter and store a pointer to the first 3233 * asconf parameter. 3234 */ 3235 length = ntohs(addr_param->p.length); 3236 chunk_len -= length; 3237 3238 /* create an ASCONF_ACK chunk. 3239 * Based on the definitions of parameters, we know that the size of 3240 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3241 * parameters. 3242 */ 3243 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3244 if (!asconf_ack) 3245 goto done; 3246 3247 /* Process the TLVs contained within the ASCONF chunk. */ 3248 sctp_walk_params(param, addip, addip_hdr.params) { 3249 /* Skip preceeding address parameters. */ 3250 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 3251 param.p->type == SCTP_PARAM_IPV6_ADDRESS) 3252 continue; 3253 3254 err_code = sctp_process_asconf_param(asoc, asconf, 3255 param.addip); 3256 /* ADDIP 4.1 A7) 3257 * If an error response is received for a TLV parameter, 3258 * all TLVs with no response before the failed TLV are 3259 * considered successful if not reported. All TLVs after 3260 * the failed response are considered unsuccessful unless 3261 * a specific success indication is present for the parameter. 3262 */ 3263 if (err_code != SCTP_ERROR_NO_ERROR) 3264 all_param_pass = false; 3265 if (!all_param_pass) 3266 sctp_add_asconf_response(asconf_ack, param.addip->crr_id, 3267 err_code, param.addip); 3268 3269 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3270 * an IP address sends an 'Out of Resource' in its response, it 3271 * MUST also fail any subsequent add or delete requests bundled 3272 * in the ASCONF. 3273 */ 3274 if (err_code == SCTP_ERROR_RSRC_LOW) 3275 goto done; 3276 } 3277 done: 3278 asoc->peer.addip_serial++; 3279 3280 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3281 * after freeing the reference to old asconf ack if any. 3282 */ 3283 if (asconf_ack) { 3284 sctp_chunk_hold(asconf_ack); 3285 list_add_tail(&asconf_ack->transmitted_list, 3286 &asoc->asconf_ack_list); 3287 } 3288 3289 return asconf_ack; 3290 } 3291 3292 /* Process a asconf parameter that is successfully acked. */ 3293 static void sctp_asconf_param_success(struct sctp_association *asoc, 3294 sctp_addip_param_t *asconf_param) 3295 { 3296 struct sctp_af *af; 3297 union sctp_addr addr; 3298 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3299 union sctp_addr_param *addr_param; 3300 struct sctp_transport *transport; 3301 struct sctp_sockaddr_entry *saddr; 3302 3303 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t); 3304 3305 /* We have checked the packet before, so we do not check again. */ 3306 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3307 af->from_addr_param(&addr, addr_param, htons(bp->port), 0); 3308 3309 switch (asconf_param->param_hdr.type) { 3310 case SCTP_PARAM_ADD_IP: 3311 /* This is always done in BH context with a socket lock 3312 * held, so the list can not change. 3313 */ 3314 local_bh_disable(); 3315 list_for_each_entry(saddr, &bp->address_list, list) { 3316 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3317 saddr->state = SCTP_ADDR_SRC; 3318 } 3319 local_bh_enable(); 3320 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3321 transports) { 3322 sctp_transport_dst_release(transport); 3323 } 3324 break; 3325 case SCTP_PARAM_DEL_IP: 3326 local_bh_disable(); 3327 sctp_del_bind_addr(bp, &addr); 3328 if (asoc->asconf_addr_del_pending != NULL && 3329 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3330 kfree(asoc->asconf_addr_del_pending); 3331 asoc->asconf_addr_del_pending = NULL; 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 default: 3340 break; 3341 } 3342 } 3343 3344 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3345 * for the given asconf parameter. If there is no response for this parameter, 3346 * return the error code based on the third argument 'no_err'. 3347 * ADDIP 4.1 3348 * A7) If an error response is received for a TLV parameter, all TLVs with no 3349 * response before the failed TLV are considered successful if not reported. 3350 * All TLVs after the failed response are considered unsuccessful unless a 3351 * specific success indication is present for the parameter. 3352 */ 3353 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3354 sctp_addip_param_t *asconf_param, 3355 int no_err) 3356 { 3357 sctp_addip_param_t *asconf_ack_param; 3358 sctp_errhdr_t *err_param; 3359 int length; 3360 int asconf_ack_len; 3361 __be16 err_code; 3362 3363 if (no_err) 3364 err_code = SCTP_ERROR_NO_ERROR; 3365 else 3366 err_code = SCTP_ERROR_REQ_REFUSED; 3367 3368 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3369 sizeof(struct sctp_chunkhdr); 3370 3371 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3372 * the first asconf_ack parameter. 3373 */ 3374 length = sizeof(sctp_addiphdr_t); 3375 asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data + 3376 length); 3377 asconf_ack_len -= length; 3378 3379 while (asconf_ack_len > 0) { 3380 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3381 switch (asconf_ack_param->param_hdr.type) { 3382 case SCTP_PARAM_SUCCESS_REPORT: 3383 return SCTP_ERROR_NO_ERROR; 3384 case SCTP_PARAM_ERR_CAUSE: 3385 length = sizeof(sctp_addip_param_t); 3386 err_param = (void *)asconf_ack_param + length; 3387 asconf_ack_len -= length; 3388 if (asconf_ack_len > 0) 3389 return err_param->cause; 3390 else 3391 return SCTP_ERROR_INV_PARAM; 3392 break; 3393 default: 3394 return SCTP_ERROR_INV_PARAM; 3395 } 3396 } 3397 3398 length = ntohs(asconf_ack_param->param_hdr.length); 3399 asconf_ack_param = (void *)asconf_ack_param + length; 3400 asconf_ack_len -= length; 3401 } 3402 3403 return err_code; 3404 } 3405 3406 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3407 int sctp_process_asconf_ack(struct sctp_association *asoc, 3408 struct sctp_chunk *asconf_ack) 3409 { 3410 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3411 union sctp_addr_param *addr_param; 3412 sctp_addip_param_t *asconf_param; 3413 int length = 0; 3414 int asconf_len = asconf->skb->len; 3415 int all_param_pass = 0; 3416 int no_err = 1; 3417 int retval = 0; 3418 __be16 err_code = SCTP_ERROR_NO_ERROR; 3419 3420 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3421 * a pointer to address parameter. 3422 */ 3423 length = sizeof(sctp_addip_chunk_t); 3424 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3425 asconf_len -= length; 3426 3427 /* Skip the address parameter in the last asconf sent and store a 3428 * pointer to the first asconf parameter. 3429 */ 3430 length = ntohs(addr_param->p.length); 3431 asconf_param = (void *)addr_param + length; 3432 asconf_len -= length; 3433 3434 /* ADDIP 4.1 3435 * A8) If there is no response(s) to specific TLV parameter(s), and no 3436 * failures are indicated, then all request(s) are considered 3437 * successful. 3438 */ 3439 if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t)) 3440 all_param_pass = 1; 3441 3442 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3443 while (asconf_len > 0) { 3444 if (all_param_pass) 3445 err_code = SCTP_ERROR_NO_ERROR; 3446 else { 3447 err_code = sctp_get_asconf_response(asconf_ack, 3448 asconf_param, 3449 no_err); 3450 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3451 no_err = 0; 3452 } 3453 3454 switch (err_code) { 3455 case SCTP_ERROR_NO_ERROR: 3456 sctp_asconf_param_success(asoc, asconf_param); 3457 break; 3458 3459 case SCTP_ERROR_RSRC_LOW: 3460 retval = 1; 3461 break; 3462 3463 case SCTP_ERROR_UNKNOWN_PARAM: 3464 /* Disable sending this type of asconf parameter in 3465 * future. 3466 */ 3467 asoc->peer.addip_disabled_mask |= 3468 asconf_param->param_hdr.type; 3469 break; 3470 3471 case SCTP_ERROR_REQ_REFUSED: 3472 case SCTP_ERROR_DEL_LAST_IP: 3473 case SCTP_ERROR_DEL_SRC_IP: 3474 default: 3475 break; 3476 } 3477 3478 /* Skip the processed asconf parameter and move to the next 3479 * one. 3480 */ 3481 length = ntohs(asconf_param->param_hdr.length); 3482 asconf_param = (void *)asconf_param + length; 3483 asconf_len -= length; 3484 } 3485 3486 if (no_err && asoc->src_out_of_asoc_ok) { 3487 asoc->src_out_of_asoc_ok = 0; 3488 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3489 } 3490 3491 /* Free the cached last sent asconf chunk. */ 3492 list_del_init(&asconf->transmitted_list); 3493 sctp_chunk_free(asconf); 3494 asoc->addip_last_asconf = NULL; 3495 3496 return retval; 3497 } 3498 3499 /* Make a FWD TSN chunk. */ 3500 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3501 __u32 new_cum_tsn, size_t nstreams, 3502 struct sctp_fwdtsn_skip *skiplist) 3503 { 3504 struct sctp_chunk *retval = NULL; 3505 struct sctp_fwdtsn_hdr ftsn_hdr; 3506 struct sctp_fwdtsn_skip skip; 3507 size_t hint; 3508 int i; 3509 3510 hint = (nstreams + 1) * sizeof(__u32); 3511 3512 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC); 3513 3514 if (!retval) 3515 return NULL; 3516 3517 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3518 retval->subh.fwdtsn_hdr = 3519 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3520 3521 for (i = 0; i < nstreams; i++) { 3522 skip.stream = skiplist[i].stream; 3523 skip.ssn = skiplist[i].ssn; 3524 sctp_addto_chunk(retval, sizeof(skip), &skip); 3525 } 3526 3527 return retval; 3528 } 3529 3530 /* RE-CONFIG 3.1 (RE-CONFIG chunk) 3531 * 0 1 2 3 3532 * 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 3533 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3534 * | Type = 130 | Chunk Flags | Chunk Length | 3535 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3536 * \ \ 3537 * / Re-configuration Parameter / 3538 * \ \ 3539 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3540 * \ \ 3541 * / Re-configuration Parameter (optional) / 3542 * \ \ 3543 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3544 */ 3545 static struct sctp_chunk *sctp_make_reconf( 3546 const struct sctp_association *asoc, 3547 int length) 3548 { 3549 struct sctp_reconf_chunk *reconf; 3550 struct sctp_chunk *retval; 3551 3552 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length, 3553 GFP_ATOMIC); 3554 if (!retval) 3555 return NULL; 3556 3557 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr; 3558 retval->param_hdr.v = reconf->params; 3559 3560 return retval; 3561 } 3562 3563 /* RE-CONFIG 4.1 (STREAM OUT RESET) 3564 * 0 1 2 3 3565 * 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 3566 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3567 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N | 3568 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3569 * | Re-configuration Request Sequence Number | 3570 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3571 * | Re-configuration Response Sequence Number | 3572 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3573 * | Sender's Last Assigned TSN | 3574 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3575 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3576 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3577 * / ...... / 3578 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3579 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3580 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3581 * 3582 * RE-CONFIG 4.2 (STREAM IN RESET) 3583 * 0 1 2 3 3584 * 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 3585 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3586 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N | 3587 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3588 * | Re-configuration Request Sequence Number | 3589 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3590 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3591 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3592 * / ...... / 3593 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3594 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3595 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3596 */ 3597 struct sctp_chunk *sctp_make_strreset_req( 3598 const struct sctp_association *asoc, 3599 __u16 stream_num, __u16 *stream_list, 3600 bool out, bool in) 3601 { 3602 struct sctp_strreset_outreq outreq; 3603 __u16 stream_len = stream_num * 2; 3604 struct sctp_strreset_inreq inreq; 3605 struct sctp_chunk *retval; 3606 __u16 outlen, inlen; 3607 3608 outlen = (sizeof(outreq) + stream_len) * out; 3609 inlen = (sizeof(inreq) + stream_len) * in; 3610 3611 retval = sctp_make_reconf(asoc, outlen + inlen); 3612 if (!retval) 3613 return NULL; 3614 3615 if (outlen) { 3616 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST; 3617 outreq.param_hdr.length = htons(outlen); 3618 outreq.request_seq = htonl(asoc->strreset_outseq); 3619 outreq.response_seq = htonl(asoc->strreset_inseq - 1); 3620 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1); 3621 3622 sctp_addto_chunk(retval, sizeof(outreq), &outreq); 3623 3624 if (stream_len) 3625 sctp_addto_chunk(retval, stream_len, stream_list); 3626 } 3627 3628 if (inlen) { 3629 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST; 3630 inreq.param_hdr.length = htons(inlen); 3631 inreq.request_seq = htonl(asoc->strreset_outseq + out); 3632 3633 sctp_addto_chunk(retval, sizeof(inreq), &inreq); 3634 3635 if (stream_len) 3636 sctp_addto_chunk(retval, stream_len, stream_list); 3637 } 3638 3639 return retval; 3640 } 3641 3642 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL) 3643 * 0 1 2 3 3644 * 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 3645 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3646 * | Parameter Type = 15 | Parameter Length = 8 | 3647 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3648 * | Re-configuration Request Sequence Number | 3649 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3650 */ 3651 struct sctp_chunk *sctp_make_strreset_tsnreq( 3652 const struct sctp_association *asoc) 3653 { 3654 struct sctp_strreset_tsnreq tsnreq; 3655 __u16 length = sizeof(tsnreq); 3656 struct sctp_chunk *retval; 3657 3658 retval = sctp_make_reconf(asoc, length); 3659 if (!retval) 3660 return NULL; 3661 3662 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST; 3663 tsnreq.param_hdr.length = htons(length); 3664 tsnreq.request_seq = htonl(asoc->strreset_outseq); 3665 3666 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq); 3667 3668 return retval; 3669 } 3670 3671 /* RE-CONFIG 4.5/4.6 (ADD STREAM) 3672 * 0 1 2 3 3673 * 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 3674 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3675 * | Parameter Type = 17 | Parameter Length = 12 | 3676 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3677 * | Re-configuration Request Sequence Number | 3678 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3679 * | Number of new streams | Reserved | 3680 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3681 */ 3682 struct sctp_chunk *sctp_make_strreset_addstrm( 3683 const struct sctp_association *asoc, 3684 __u16 out, __u16 in) 3685 { 3686 struct sctp_strreset_addstrm addstrm; 3687 __u16 size = sizeof(addstrm); 3688 struct sctp_chunk *retval; 3689 3690 retval = sctp_make_reconf(asoc, (!!out + !!in) * size); 3691 if (!retval) 3692 return NULL; 3693 3694 if (out) { 3695 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS; 3696 addstrm.param_hdr.length = htons(size); 3697 addstrm.number_of_streams = htons(out); 3698 addstrm.request_seq = htonl(asoc->strreset_outseq); 3699 addstrm.reserved = 0; 3700 3701 sctp_addto_chunk(retval, size, &addstrm); 3702 } 3703 3704 if (in) { 3705 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS; 3706 addstrm.param_hdr.length = htons(size); 3707 addstrm.number_of_streams = htons(in); 3708 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out); 3709 addstrm.reserved = 0; 3710 3711 sctp_addto_chunk(retval, size, &addstrm); 3712 } 3713 3714 return retval; 3715 } 3716 3717 /* RE-CONFIG 4.4 (RESP) 3718 * 0 1 2 3 3719 * 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 3720 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3721 * | Parameter Type = 16 | Parameter Length | 3722 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3723 * | Re-configuration Response Sequence Number | 3724 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3725 * | Result | 3726 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3727 */ 3728 struct sctp_chunk *sctp_make_strreset_resp( 3729 const struct sctp_association *asoc, 3730 __u32 result, __u32 sn) 3731 { 3732 struct sctp_strreset_resp resp; 3733 __u16 length = sizeof(resp); 3734 struct sctp_chunk *retval; 3735 3736 retval = sctp_make_reconf(asoc, length); 3737 if (!retval) 3738 return NULL; 3739 3740 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3741 resp.param_hdr.length = htons(length); 3742 resp.response_seq = htonl(sn); 3743 resp.result = htonl(result); 3744 3745 sctp_addto_chunk(retval, sizeof(resp), &resp); 3746 3747 return retval; 3748 } 3749 3750 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP) 3751 * 0 1 2 3 3752 * 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 3753 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3754 * | Parameter Type = 16 | Parameter Length | 3755 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3756 * | Re-configuration Response Sequence Number | 3757 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3758 * | Result | 3759 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3760 * | Sender's Next TSN (optional) | 3761 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3762 * | Receiver's Next TSN (optional) | 3763 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3764 */ 3765 struct sctp_chunk *sctp_make_strreset_tsnresp( 3766 struct sctp_association *asoc, 3767 __u32 result, __u32 sn, 3768 __u32 sender_tsn, __u32 receiver_tsn) 3769 { 3770 struct sctp_strreset_resptsn tsnresp; 3771 __u16 length = sizeof(tsnresp); 3772 struct sctp_chunk *retval; 3773 3774 retval = sctp_make_reconf(asoc, length); 3775 if (!retval) 3776 return NULL; 3777 3778 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3779 tsnresp.param_hdr.length = htons(length); 3780 3781 tsnresp.response_seq = htonl(sn); 3782 tsnresp.result = htonl(result); 3783 tsnresp.senders_next_tsn = htonl(sender_tsn); 3784 tsnresp.receivers_next_tsn = htonl(receiver_tsn); 3785 3786 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp); 3787 3788 return retval; 3789 } 3790 3791 bool sctp_verify_reconf(const struct sctp_association *asoc, 3792 struct sctp_chunk *chunk, 3793 struct sctp_paramhdr **errp) 3794 { 3795 struct sctp_reconf_chunk *hdr; 3796 union sctp_params param; 3797 __u16 last = 0, cnt = 0; 3798 3799 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; 3800 sctp_walk_params(param, hdr, params) { 3801 __u16 length = ntohs(param.p->length); 3802 3803 *errp = param.p; 3804 if (cnt++ > 2) 3805 return false; 3806 switch (param.p->type) { 3807 case SCTP_PARAM_RESET_OUT_REQUEST: 3808 if (length < sizeof(struct sctp_strreset_outreq) || 3809 (last && last != SCTP_PARAM_RESET_RESPONSE && 3810 last != SCTP_PARAM_RESET_IN_REQUEST)) 3811 return false; 3812 break; 3813 case SCTP_PARAM_RESET_IN_REQUEST: 3814 if (length < sizeof(struct sctp_strreset_inreq) || 3815 (last && last != SCTP_PARAM_RESET_OUT_REQUEST)) 3816 return false; 3817 break; 3818 case SCTP_PARAM_RESET_RESPONSE: 3819 if ((length != sizeof(struct sctp_strreset_resp) && 3820 length != sizeof(struct sctp_strreset_resptsn)) || 3821 (last && last != SCTP_PARAM_RESET_RESPONSE && 3822 last != SCTP_PARAM_RESET_OUT_REQUEST)) 3823 return false; 3824 break; 3825 case SCTP_PARAM_RESET_TSN_REQUEST: 3826 if (length != 3827 sizeof(struct sctp_strreset_tsnreq) || last) 3828 return false; 3829 break; 3830 case SCTP_PARAM_RESET_ADD_IN_STREAMS: 3831 if (length != sizeof(struct sctp_strreset_addstrm) || 3832 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS)) 3833 return false; 3834 break; 3835 case SCTP_PARAM_RESET_ADD_OUT_STREAMS: 3836 if (length != sizeof(struct sctp_strreset_addstrm) || 3837 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS)) 3838 return false; 3839 break; 3840 default: 3841 return false; 3842 } 3843 3844 last = param.p->type; 3845 } 3846 3847 return true; 3848 } 3849