1 /* SCTP kernel implementation 2 * (C) Copyright IBM Corp. 2001, 2004 3 * Copyright (c) 1999-2000 Cisco, Inc. 4 * Copyright (c) 1999-2001 Motorola, Inc. 5 * Copyright (c) 2001-2002 Intel Corp. 6 * 7 * This file is part of the SCTP kernel implementation 8 * 9 * These functions work with the state functions in sctp_sm_statefuns.c 10 * to implement the state operations. These functions implement the 11 * steps which require modifying existing data structures. 12 * 13 * This SCTP implementation is free software; 14 * you can redistribute it and/or modify it under the terms of 15 * the GNU General Public License as published by 16 * the Free Software Foundation; either version 2, or (at your option) 17 * any later version. 18 * 19 * This SCTP implementation is distributed in the hope that it 20 * will be useful, but WITHOUT ANY WARRANTY; without even the implied 21 * ************************ 22 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 23 * See the GNU General Public License for more details. 24 * 25 * You should have received a copy of the GNU General Public License 26 * along with GNU CC; see the file COPYING. If not, see 27 * <http://www.gnu.org/licenses/>. 28 * 29 * Please send any bug reports or fixes you make to the 30 * email address(es): 31 * lksctp developers <linux-sctp@vger.kernel.org> 32 * 33 * Written or modified by: 34 * La Monte H.P. Yarroll <piggy@acm.org> 35 * Karl Knutson <karl@athena.chicago.il.us> 36 * C. Robin <chris@hundredacre.ac.uk> 37 * Jon Grimm <jgrimm@us.ibm.com> 38 * Xingang Guo <xingang.guo@intel.com> 39 * Dajiang Zhang <dajiang.zhang@nokia.com> 40 * Sridhar Samudrala <sri@us.ibm.com> 41 * Daisy Chang <daisyc@us.ibm.com> 42 * Ardelle Fan <ardelle.fan@intel.com> 43 * Kevin Gao <kevin.gao@intel.com> 44 */ 45 46 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 47 48 #include <crypto/hash.h> 49 #include <linux/types.h> 50 #include <linux/kernel.h> 51 #include <linux/ip.h> 52 #include <linux/ipv6.h> 53 #include <linux/net.h> 54 #include <linux/inet.h> 55 #include <linux/scatterlist.h> 56 #include <linux/slab.h> 57 #include <net/sock.h> 58 59 #include <linux/skbuff.h> 60 #include <linux/random.h> /* for get_random_bytes */ 61 #include <net/sctp/sctp.h> 62 #include <net/sctp/sm.h> 63 64 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 65 __u8 type, __u8 flags, int paylen, 66 gfp_t gfp); 67 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 68 __u8 flags, int paylen, gfp_t gfp); 69 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 70 __u8 type, __u8 flags, int paylen, 71 gfp_t gfp); 72 static struct sctp_cookie_param *sctp_pack_cookie( 73 const struct sctp_endpoint *ep, 74 const struct sctp_association *asoc, 75 const struct sctp_chunk *init_chunk, 76 int *cookie_len, 77 const __u8 *raw_addrs, int addrs_len); 78 static int sctp_process_param(struct sctp_association *asoc, 79 union sctp_params param, 80 const union sctp_addr *peer_addr, 81 gfp_t gfp); 82 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 83 const void *data); 84 static void *sctp_addto_chunk_fixed(struct sctp_chunk *, int len, 85 const void *data); 86 87 /* Control chunk destructor */ 88 static void sctp_control_release_owner(struct sk_buff *skb) 89 { 90 /*TODO: do memory release */ 91 } 92 93 static void sctp_control_set_owner_w(struct sctp_chunk *chunk) 94 { 95 struct sctp_association *asoc = chunk->asoc; 96 struct sk_buff *skb = chunk->skb; 97 98 /* TODO: properly account for control chunks. 99 * To do it right we'll need: 100 * 1) endpoint if association isn't known. 101 * 2) proper memory accounting. 102 * 103 * For now don't do anything for now. 104 */ 105 skb->sk = asoc ? asoc->base.sk : NULL; 106 skb->destructor = sctp_control_release_owner; 107 } 108 109 /* What was the inbound interface for this chunk? */ 110 int sctp_chunk_iif(const struct sctp_chunk *chunk) 111 { 112 struct sk_buff *skb = chunk->skb; 113 114 return SCTP_INPUT_CB(skb)->af->skb_iif(skb); 115 } 116 117 /* RFC 2960 3.3.2 Initiation (INIT) (1) 118 * 119 * Note 2: The ECN capable field is reserved for future use of 120 * Explicit Congestion Notification. 121 */ 122 static const struct sctp_paramhdr ecap_param = { 123 SCTP_PARAM_ECN_CAPABLE, 124 cpu_to_be16(sizeof(struct sctp_paramhdr)), 125 }; 126 static const struct sctp_paramhdr prsctp_param = { 127 SCTP_PARAM_FWD_TSN_SUPPORT, 128 cpu_to_be16(sizeof(struct sctp_paramhdr)), 129 }; 130 131 /* A helper to initialize an op error inside a 132 * provided chunk, as most cause codes will be embedded inside an 133 * abort chunk. 134 */ 135 void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, 136 size_t paylen) 137 { 138 struct sctp_errhdr err; 139 __u16 len; 140 141 /* Cause code constants are now defined in network order. */ 142 err.cause = cause_code; 143 len = sizeof(err) + paylen; 144 err.length = htons(len); 145 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(err), &err); 146 } 147 148 /* A helper to initialize an op error inside a 149 * provided chunk, as most cause codes will be embedded inside an 150 * abort chunk. Differs from sctp_init_cause in that it won't oops 151 * if there isn't enough space in the op error chunk 152 */ 153 static int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code, 154 size_t paylen) 155 { 156 struct sctp_errhdr err; 157 __u16 len; 158 159 /* Cause code constants are now defined in network order. */ 160 err.cause = cause_code; 161 len = sizeof(err) + paylen; 162 err.length = htons(len); 163 164 if (skb_tailroom(chunk->skb) < len) 165 return -ENOSPC; 166 167 chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk, sizeof(err), &err); 168 169 return 0; 170 } 171 /* 3.3.2 Initiation (INIT) (1) 172 * 173 * This chunk is used to initiate a SCTP association between two 174 * endpoints. The format of the INIT chunk is shown below: 175 * 176 * 0 1 2 3 177 * 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 1 178 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 179 * | Type = 1 | Chunk Flags | Chunk Length | 180 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 181 * | Initiate Tag | 182 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 183 * | Advertised Receiver Window Credit (a_rwnd) | 184 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 185 * | Number of Outbound Streams | Number of Inbound Streams | 186 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 187 * | Initial TSN | 188 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 189 * \ \ 190 * / Optional/Variable-Length Parameters / 191 * \ \ 192 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 193 * 194 * 195 * The INIT chunk contains the following parameters. Unless otherwise 196 * noted, each parameter MUST only be included once in the INIT chunk. 197 * 198 * Fixed Parameters Status 199 * ---------------------------------------------- 200 * Initiate Tag Mandatory 201 * Advertised Receiver Window Credit Mandatory 202 * Number of Outbound Streams Mandatory 203 * Number of Inbound Streams Mandatory 204 * Initial TSN Mandatory 205 * 206 * Variable Parameters Status Type Value 207 * ------------------------------------------------------------- 208 * IPv4 Address (Note 1) Optional 5 209 * IPv6 Address (Note 1) Optional 6 210 * Cookie Preservative Optional 9 211 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000) 212 * Host Name Address (Note 3) Optional 11 213 * Supported Address Types (Note 4) Optional 12 214 */ 215 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc, 216 const struct sctp_bind_addr *bp, 217 gfp_t gfp, int vparam_len) 218 { 219 struct net *net = sock_net(asoc->base.sk); 220 struct sctp_endpoint *ep = asoc->ep; 221 struct sctp_inithdr init; 222 union sctp_params addrs; 223 size_t chunksize; 224 struct sctp_chunk *retval = NULL; 225 int num_types, addrs_len = 0; 226 struct sctp_sock *sp; 227 struct sctp_supported_addrs_param sat; 228 __be16 types[2]; 229 struct sctp_adaptation_ind_param aiparam; 230 struct sctp_supported_ext_param ext_param; 231 int num_ext = 0; 232 __u8 extensions[4]; 233 struct sctp_paramhdr *auth_chunks = NULL, 234 *auth_hmacs = NULL; 235 236 /* RFC 2960 3.3.2 Initiation (INIT) (1) 237 * 238 * Note 1: The INIT chunks can contain multiple addresses that 239 * can be IPv4 and/or IPv6 in any combination. 240 */ 241 retval = NULL; 242 243 /* Convert the provided bind address list to raw format. */ 244 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp); 245 246 init.init_tag = htonl(asoc->c.my_vtag); 247 init.a_rwnd = htonl(asoc->rwnd); 248 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 249 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 250 init.initial_tsn = htonl(asoc->c.initial_tsn); 251 252 /* How many address types are needed? */ 253 sp = sctp_sk(asoc->base.sk); 254 num_types = sp->pf->supported_addrs(sp, types); 255 256 chunksize = sizeof(init) + addrs_len; 257 chunksize += SCTP_PAD4(SCTP_SAT_LEN(num_types)); 258 chunksize += sizeof(ecap_param); 259 260 if (asoc->prsctp_enable) 261 chunksize += sizeof(prsctp_param); 262 263 /* ADDIP: Section 4.2.7: 264 * An implementation supporting this extension [ADDIP] MUST list 265 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and 266 * INIT-ACK parameters. 267 */ 268 if (net->sctp.addip_enable) { 269 extensions[num_ext] = SCTP_CID_ASCONF; 270 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 271 num_ext += 2; 272 } 273 274 if (asoc->reconf_enable) { 275 extensions[num_ext] = SCTP_CID_RECONF; 276 num_ext += 1; 277 } 278 279 if (sp->adaptation_ind) 280 chunksize += sizeof(aiparam); 281 282 chunksize += vparam_len; 283 284 /* Account for AUTH related parameters */ 285 if (ep->auth_enable) { 286 /* Add random parameter length*/ 287 chunksize += sizeof(asoc->c.auth_random); 288 289 /* Add HMACS parameter length if any were defined */ 290 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; 291 if (auth_hmacs->length) 292 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 293 else 294 auth_hmacs = NULL; 295 296 /* Add CHUNKS parameter length */ 297 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; 298 if (auth_chunks->length) 299 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 300 else 301 auth_chunks = NULL; 302 303 extensions[num_ext] = SCTP_CID_AUTH; 304 num_ext += 1; 305 } 306 307 /* If we have any extensions to report, account for that */ 308 if (num_ext) 309 chunksize += SCTP_PAD4(sizeof(ext_param) + 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 = htons(sizeof(ext_param) + num_ext); 352 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); 353 sctp_addto_param(retval, num_ext, extensions); 354 } 355 356 if (asoc->prsctp_enable) 357 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 358 359 if (sp->adaptation_ind) { 360 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 361 aiparam.param_hdr.length = htons(sizeof(aiparam)); 362 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 363 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 364 } 365 366 /* Add SCTP-AUTH chunks to the parameter list */ 367 if (ep->auth_enable) { 368 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random), 369 asoc->c.auth_random); 370 if (auth_hmacs) 371 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 372 auth_hmacs); 373 if (auth_chunks) 374 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 375 auth_chunks); 376 } 377 nodata: 378 kfree(addrs.v); 379 return retval; 380 } 381 382 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, 383 const struct sctp_chunk *chunk, 384 gfp_t gfp, int unkparam_len) 385 { 386 struct sctp_inithdr initack; 387 struct sctp_chunk *retval; 388 union sctp_params addrs; 389 struct sctp_sock *sp; 390 int addrs_len; 391 struct sctp_cookie_param *cookie; 392 int cookie_len; 393 size_t chunksize; 394 struct sctp_adaptation_ind_param aiparam; 395 struct sctp_supported_ext_param ext_param; 396 int num_ext = 0; 397 __u8 extensions[4]; 398 struct sctp_paramhdr *auth_chunks = NULL, 399 *auth_hmacs = NULL, 400 *auth_random = NULL; 401 402 retval = NULL; 403 404 /* Note: there may be no addresses to embed. */ 405 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp); 406 407 initack.init_tag = htonl(asoc->c.my_vtag); 408 initack.a_rwnd = htonl(asoc->rwnd); 409 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 410 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 411 initack.initial_tsn = htonl(asoc->c.initial_tsn); 412 413 /* FIXME: We really ought to build the cookie right 414 * into the packet instead of allocating more fresh memory. 415 */ 416 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len, 417 addrs.v, addrs_len); 418 if (!cookie) 419 goto nomem_cookie; 420 421 /* Calculate the total size of allocation, include the reserved 422 * space for reporting unknown parameters if it is specified. 423 */ 424 sp = sctp_sk(asoc->base.sk); 425 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len; 426 427 /* Tell peer that we'll do ECN only if peer advertised such cap. */ 428 if (asoc->peer.ecn_capable) 429 chunksize += sizeof(ecap_param); 430 431 if (asoc->peer.prsctp_capable) 432 chunksize += sizeof(prsctp_param); 433 434 if (asoc->peer.asconf_capable) { 435 extensions[num_ext] = SCTP_CID_ASCONF; 436 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 437 num_ext += 2; 438 } 439 440 if (asoc->peer.reconf_capable) { 441 extensions[num_ext] = SCTP_CID_RECONF; 442 num_ext += 1; 443 } 444 445 if (sp->adaptation_ind) 446 chunksize += sizeof(aiparam); 447 448 if (asoc->peer.auth_capable) { 449 auth_random = (struct sctp_paramhdr *)asoc->c.auth_random; 450 chunksize += ntohs(auth_random->length); 451 452 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; 453 if (auth_hmacs->length) 454 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 455 else 456 auth_hmacs = NULL; 457 458 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; 459 if (auth_chunks->length) 460 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 461 else 462 auth_chunks = NULL; 463 464 extensions[num_ext] = SCTP_CID_AUTH; 465 num_ext += 1; 466 } 467 468 if (num_ext) 469 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext); 470 471 /* Now allocate and fill out the chunk. */ 472 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp); 473 if (!retval) 474 goto nomem_chunk; 475 476 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 477 * 478 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 479 * HEARTBEAT ACK, * etc.) to the same destination transport 480 * address from which it received the DATA or control chunk 481 * to which it is replying. 482 * 483 * [INIT ACK back to where the INIT came from.] 484 */ 485 retval->transport = chunk->transport; 486 487 retval->subh.init_hdr = 488 sctp_addto_chunk(retval, sizeof(initack), &initack); 489 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); 490 sctp_addto_chunk(retval, cookie_len, cookie); 491 if (asoc->peer.ecn_capable) 492 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 493 if (num_ext) { 494 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 495 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext); 496 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); 497 sctp_addto_param(retval, num_ext, extensions); 498 } 499 if (asoc->peer.prsctp_capable) 500 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 501 502 if (sp->adaptation_ind) { 503 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 504 aiparam.param_hdr.length = htons(sizeof(aiparam)); 505 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 506 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 507 } 508 509 if (asoc->peer.auth_capable) { 510 sctp_addto_chunk(retval, ntohs(auth_random->length), 511 auth_random); 512 if (auth_hmacs) 513 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 514 auth_hmacs); 515 if (auth_chunks) 516 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 517 auth_chunks); 518 } 519 520 /* We need to remove the const qualifier at this point. */ 521 retval->asoc = (struct sctp_association *) asoc; 522 523 nomem_chunk: 524 kfree(cookie); 525 nomem_cookie: 526 kfree(addrs.v); 527 return retval; 528 } 529 530 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10): 531 * 532 * This chunk is used only during the initialization of an association. 533 * It is sent by the initiator of an association to its peer to complete 534 * the initialization process. This chunk MUST precede any DATA chunk 535 * sent within the association, but MAY be bundled with one or more DATA 536 * chunks in the same packet. 537 * 538 * 0 1 2 3 539 * 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 1 540 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 541 * | Type = 10 |Chunk Flags | Length | 542 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 543 * / Cookie / 544 * \ \ 545 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 546 * 547 * Chunk Flags: 8 bit 548 * 549 * Set to zero on transmit and ignored on receipt. 550 * 551 * Length: 16 bits (unsigned integer) 552 * 553 * Set to the size of the chunk in bytes, including the 4 bytes of 554 * the chunk header and the size of the Cookie. 555 * 556 * Cookie: variable size 557 * 558 * This field must contain the exact cookie received in the 559 * State Cookie parameter from the previous INIT ACK. 560 * 561 * An implementation SHOULD make the cookie as small as possible 562 * to insure interoperability. 563 */ 564 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, 565 const struct sctp_chunk *chunk) 566 { 567 struct sctp_chunk *retval; 568 void *cookie; 569 int cookie_len; 570 571 cookie = asoc->peer.cookie; 572 cookie_len = asoc->peer.cookie_len; 573 574 /* Build a cookie echo chunk. */ 575 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0, 576 cookie_len, GFP_ATOMIC); 577 if (!retval) 578 goto nodata; 579 retval->subh.cookie_hdr = 580 sctp_addto_chunk(retval, cookie_len, cookie); 581 582 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 583 * 584 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 585 * HEARTBEAT ACK, * etc.) to the same destination transport 586 * address from which it * received the DATA or control chunk 587 * to which it is replying. 588 * 589 * [COOKIE ECHO back to where the INIT ACK came from.] 590 */ 591 if (chunk) 592 retval->transport = chunk->transport; 593 594 nodata: 595 return retval; 596 } 597 598 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11): 599 * 600 * This chunk is used only during the initialization of an 601 * association. It is used to acknowledge the receipt of a COOKIE 602 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent 603 * within the association, but MAY be bundled with one or more DATA 604 * chunks or SACK chunk in the same SCTP packet. 605 * 606 * 0 1 2 3 607 * 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 1 608 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 609 * | Type = 11 |Chunk Flags | Length = 4 | 610 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 611 * 612 * Chunk Flags: 8 bits 613 * 614 * Set to zero on transmit and ignored on receipt. 615 */ 616 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, 617 const struct sctp_chunk *chunk) 618 { 619 struct sctp_chunk *retval; 620 621 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC); 622 623 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 624 * 625 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 626 * HEARTBEAT ACK, * etc.) to the same destination transport 627 * address from which it * received the DATA or control chunk 628 * to which it is replying. 629 * 630 * [COOKIE ACK back to where the COOKIE ECHO came from.] 631 */ 632 if (retval && chunk) 633 retval->transport = chunk->transport; 634 635 return retval; 636 } 637 638 /* 639 * Appendix A: Explicit Congestion Notification: 640 * CWR: 641 * 642 * RFC 2481 details a specific bit for a sender to send in the header of 643 * its next outbound TCP segment to indicate to its peer that it has 644 * reduced its congestion window. This is termed the CWR bit. For 645 * SCTP the same indication is made by including the CWR chunk. 646 * This chunk contains one data element, i.e. the TSN number that 647 * was sent in the ECNE chunk. This element represents the lowest 648 * TSN number in the datagram that was originally marked with the 649 * CE bit. 650 * 651 * 0 1 2 3 652 * 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 1 653 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 654 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 | 655 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 656 * | Lowest TSN Number | 657 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 658 * 659 * Note: The CWR is considered a Control chunk. 660 */ 661 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, 662 const __u32 lowest_tsn, 663 const struct sctp_chunk *chunk) 664 { 665 struct sctp_chunk *retval; 666 struct sctp_cwrhdr cwr; 667 668 cwr.lowest_tsn = htonl(lowest_tsn); 669 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0, 670 sizeof(cwr), GFP_ATOMIC); 671 672 if (!retval) 673 goto nodata; 674 675 retval->subh.ecn_cwr_hdr = 676 sctp_addto_chunk(retval, sizeof(cwr), &cwr); 677 678 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 679 * 680 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 681 * HEARTBEAT ACK, * etc.) to the same destination transport 682 * address from which it * received the DATA or control chunk 683 * to which it is replying. 684 * 685 * [Report a reduced congestion window back to where the ECNE 686 * came from.] 687 */ 688 if (chunk) 689 retval->transport = chunk->transport; 690 691 nodata: 692 return retval; 693 } 694 695 /* Make an ECNE chunk. This is a congestion experienced report. */ 696 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, 697 const __u32 lowest_tsn) 698 { 699 struct sctp_chunk *retval; 700 struct sctp_ecnehdr ecne; 701 702 ecne.lowest_tsn = htonl(lowest_tsn); 703 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0, 704 sizeof(ecne), GFP_ATOMIC); 705 if (!retval) 706 goto nodata; 707 retval->subh.ecne_hdr = 708 sctp_addto_chunk(retval, sizeof(ecne), &ecne); 709 710 nodata: 711 return retval; 712 } 713 714 /* Make a DATA chunk for the given association from the provided 715 * parameters. However, do not populate the data payload. 716 */ 717 struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc, 718 const struct sctp_sndrcvinfo *sinfo, 719 int data_len, __u8 flags, __u16 ssn, 720 gfp_t gfp) 721 { 722 struct sctp_chunk *retval; 723 struct sctp_datahdr dp; 724 int chunk_len; 725 726 /* We assign the TSN as LATE as possible, not here when 727 * creating the chunk. 728 */ 729 dp.tsn = 0; 730 dp.stream = htons(sinfo->sinfo_stream); 731 dp.ppid = sinfo->sinfo_ppid; 732 733 /* Set the flags for an unordered send. */ 734 if (sinfo->sinfo_flags & SCTP_UNORDERED) { 735 flags |= SCTP_DATA_UNORDERED; 736 dp.ssn = 0; 737 } else 738 dp.ssn = htons(ssn); 739 740 chunk_len = sizeof(dp) + data_len; 741 retval = sctp_make_data(asoc, flags, chunk_len, gfp); 742 if (!retval) 743 goto nodata; 744 745 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp); 746 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo)); 747 748 nodata: 749 return retval; 750 } 751 752 /* Create a selective ackowledgement (SACK) for the given 753 * association. This reports on which TSN's we've seen to date, 754 * including duplicates and gaps. 755 */ 756 struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc) 757 { 758 struct sctp_chunk *retval; 759 struct sctp_sackhdr sack; 760 int len; 761 __u32 ctsn; 762 __u16 num_gabs, num_dup_tsns; 763 struct sctp_association *aptr = (struct sctp_association *)asoc; 764 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; 765 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; 766 struct sctp_transport *trans; 767 768 memset(gabs, 0, sizeof(gabs)); 769 ctsn = sctp_tsnmap_get_ctsn(map); 770 771 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn); 772 773 /* How much room is needed in the chunk? */ 774 num_gabs = sctp_tsnmap_num_gabs(map, gabs); 775 num_dup_tsns = sctp_tsnmap_num_dups(map); 776 777 /* Initialize the SACK header. */ 778 sack.cum_tsn_ack = htonl(ctsn); 779 sack.a_rwnd = htonl(asoc->a_rwnd); 780 sack.num_gap_ack_blocks = htons(num_gabs); 781 sack.num_dup_tsns = htons(num_dup_tsns); 782 783 len = sizeof(sack) 784 + sizeof(struct sctp_gap_ack_block) * num_gabs 785 + sizeof(__u32) * num_dup_tsns; 786 787 /* Create the chunk. */ 788 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC); 789 if (!retval) 790 goto nodata; 791 792 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 793 * 794 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 795 * HEARTBEAT ACK, etc.) to the same destination transport 796 * address from which it received the DATA or control chunk to 797 * which it is replying. This rule should also be followed if 798 * the endpoint is bundling DATA chunks together with the 799 * reply chunk. 800 * 801 * However, when acknowledging multiple DATA chunks received 802 * in packets from different source addresses in a single 803 * SACK, the SACK chunk may be transmitted to one of the 804 * destination transport addresses from which the DATA or 805 * control chunks being acknowledged were received. 806 * 807 * [BUG: We do not implement the following paragraph. 808 * Perhaps we should remember the last transport we used for a 809 * SACK and avoid that (if possible) if we have seen any 810 * duplicates. --piggy] 811 * 812 * When a receiver of a duplicate DATA chunk sends a SACK to a 813 * multi- homed endpoint it MAY be beneficial to vary the 814 * destination address and not use the source address of the 815 * DATA chunk. The reason being that receiving a duplicate 816 * from a multi-homed endpoint might indicate that the return 817 * path (as specified in the source address of the DATA chunk) 818 * for the SACK is broken. 819 * 820 * [Send to the address from which we last received a DATA chunk.] 821 */ 822 retval->transport = asoc->peer.last_data_from; 823 824 retval->subh.sack_hdr = 825 sctp_addto_chunk(retval, sizeof(sack), &sack); 826 827 /* Add the gap ack block information. */ 828 if (num_gabs) 829 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, 830 gabs); 831 832 /* Add the duplicate TSN information. */ 833 if (num_dup_tsns) { 834 aptr->stats.idupchunks += num_dup_tsns; 835 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, 836 sctp_tsnmap_get_dups(map)); 837 } 838 /* Once we have a sack generated, check to see what our sack 839 * generation is, if its 0, reset the transports to 0, and reset 840 * the association generation to 1 841 * 842 * The idea is that zero is never used as a valid generation for the 843 * association so no transport will match after a wrap event like this, 844 * Until the next sack 845 */ 846 if (++aptr->peer.sack_generation == 0) { 847 list_for_each_entry(trans, &asoc->peer.transport_addr_list, 848 transports) 849 trans->sack_generation = 0; 850 aptr->peer.sack_generation = 1; 851 } 852 nodata: 853 return retval; 854 } 855 856 /* Make a SHUTDOWN chunk. */ 857 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 858 const struct sctp_chunk *chunk) 859 { 860 struct sctp_shutdownhdr shut; 861 struct sctp_chunk *retval; 862 __u32 ctsn; 863 864 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 865 shut.cum_tsn_ack = htonl(ctsn); 866 867 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0, 868 sizeof(shut), GFP_ATOMIC); 869 if (!retval) 870 goto nodata; 871 872 retval->subh.shutdown_hdr = 873 sctp_addto_chunk(retval, sizeof(shut), &shut); 874 875 if (chunk) 876 retval->transport = chunk->transport; 877 nodata: 878 return retval; 879 } 880 881 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 882 const struct sctp_chunk *chunk) 883 { 884 struct sctp_chunk *retval; 885 886 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0, 887 GFP_ATOMIC); 888 889 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 890 * 891 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 892 * HEARTBEAT ACK, * etc.) to the same destination transport 893 * address from which it * received the DATA or control chunk 894 * to which it is replying. 895 * 896 * [ACK back to where the SHUTDOWN came from.] 897 */ 898 if (retval && chunk) 899 retval->transport = chunk->transport; 900 901 return retval; 902 } 903 904 struct sctp_chunk *sctp_make_shutdown_complete( 905 const struct sctp_association *asoc, 906 const struct sctp_chunk *chunk) 907 { 908 struct sctp_chunk *retval; 909 __u8 flags = 0; 910 911 /* Set the T-bit if we have no association (vtag will be 912 * reflected) 913 */ 914 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; 915 916 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 917 0, GFP_ATOMIC); 918 919 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 920 * 921 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 922 * HEARTBEAT ACK, * etc.) to the same destination transport 923 * address from which it * received the DATA or control chunk 924 * to which it is replying. 925 * 926 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK 927 * came from.] 928 */ 929 if (retval && chunk) 930 retval->transport = chunk->transport; 931 932 return retval; 933 } 934 935 /* Create an ABORT. Note that we set the T bit if we have no 936 * association, except when responding to an INIT (sctpimpguide 2.41). 937 */ 938 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 939 const struct sctp_chunk *chunk, 940 const size_t hint) 941 { 942 struct sctp_chunk *retval; 943 __u8 flags = 0; 944 945 /* Set the T-bit if we have no association and 'chunk' is not 946 * an INIT (vtag will be reflected). 947 */ 948 if (!asoc) { 949 if (chunk && chunk->chunk_hdr && 950 chunk->chunk_hdr->type == SCTP_CID_INIT) 951 flags = 0; 952 else 953 flags = SCTP_CHUNK_FLAG_T; 954 } 955 956 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint, 957 GFP_ATOMIC); 958 959 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 960 * 961 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 962 * HEARTBEAT ACK, * etc.) to the same destination transport 963 * address from which it * received the DATA or control chunk 964 * to which it is replying. 965 * 966 * [ABORT back to where the offender came from.] 967 */ 968 if (retval && chunk) 969 retval->transport = chunk->transport; 970 971 return retval; 972 } 973 974 /* Helper to create ABORT with a NO_USER_DATA error. */ 975 struct sctp_chunk *sctp_make_abort_no_data( 976 const struct sctp_association *asoc, 977 const struct sctp_chunk *chunk, __u32 tsn) 978 { 979 struct sctp_chunk *retval; 980 __be32 payload; 981 982 retval = sctp_make_abort(asoc, chunk, 983 sizeof(struct sctp_errhdr) + sizeof(tsn)); 984 985 if (!retval) 986 goto no_mem; 987 988 /* Put the tsn back into network byte order. */ 989 payload = htonl(tsn); 990 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload)); 991 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload); 992 993 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 994 * 995 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 996 * HEARTBEAT ACK, * etc.) to the same destination transport 997 * address from which it * received the DATA or control chunk 998 * to which it is replying. 999 * 1000 * [ABORT back to where the offender came from.] 1001 */ 1002 if (chunk) 1003 retval->transport = chunk->transport; 1004 1005 no_mem: 1006 return retval; 1007 } 1008 1009 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ 1010 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 1011 struct msghdr *msg, 1012 size_t paylen) 1013 { 1014 struct sctp_chunk *retval; 1015 void *payload = NULL; 1016 int err; 1017 1018 retval = sctp_make_abort(asoc, NULL, 1019 sizeof(struct sctp_errhdr) + paylen); 1020 if (!retval) 1021 goto err_chunk; 1022 1023 if (paylen) { 1024 /* Put the msg_iov together into payload. */ 1025 payload = kmalloc(paylen, GFP_KERNEL); 1026 if (!payload) 1027 goto err_payload; 1028 1029 err = memcpy_from_msg(payload, msg, paylen); 1030 if (err < 0) 1031 goto err_copy; 1032 } 1033 1034 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); 1035 sctp_addto_chunk(retval, paylen, payload); 1036 1037 if (paylen) 1038 kfree(payload); 1039 1040 return retval; 1041 1042 err_copy: 1043 kfree(payload); 1044 err_payload: 1045 sctp_chunk_free(retval); 1046 retval = NULL; 1047 err_chunk: 1048 return retval; 1049 } 1050 1051 /* Append bytes to the end of a parameter. Will panic if chunk is not big 1052 * enough. 1053 */ 1054 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 1055 const void *data) 1056 { 1057 void *target; 1058 int chunklen = ntohs(chunk->chunk_hdr->length); 1059 1060 target = skb_put(chunk->skb, len); 1061 1062 if (data) 1063 memcpy(target, data, len); 1064 else 1065 memset(target, 0, len); 1066 1067 /* Adjust the chunk length field. */ 1068 chunk->chunk_hdr->length = htons(chunklen + len); 1069 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1070 1071 return target; 1072 } 1073 1074 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ 1075 struct sctp_chunk *sctp_make_abort_violation( 1076 const struct sctp_association *asoc, 1077 const struct sctp_chunk *chunk, 1078 const __u8 *payload, 1079 const size_t paylen) 1080 { 1081 struct sctp_chunk *retval; 1082 struct sctp_paramhdr phdr; 1083 1084 retval = sctp_make_abort(asoc, chunk, sizeof(struct sctp_errhdr) + 1085 paylen + sizeof(phdr)); 1086 if (!retval) 1087 goto end; 1088 1089 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen + 1090 sizeof(phdr)); 1091 1092 phdr.type = htons(chunk->chunk_hdr->type); 1093 phdr.length = chunk->chunk_hdr->length; 1094 sctp_addto_chunk(retval, paylen, payload); 1095 sctp_addto_param(retval, sizeof(phdr), &phdr); 1096 1097 end: 1098 return retval; 1099 } 1100 1101 struct sctp_chunk *sctp_make_violation_paramlen( 1102 const struct sctp_association *asoc, 1103 const struct sctp_chunk *chunk, 1104 struct sctp_paramhdr *param) 1105 { 1106 struct sctp_chunk *retval; 1107 static const char error[] = "The following parameter had invalid length:"; 1108 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr) + 1109 sizeof(*param); 1110 1111 retval = sctp_make_abort(asoc, chunk, payload_len); 1112 if (!retval) 1113 goto nodata; 1114 1115 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, 1116 sizeof(error) + sizeof(*param)); 1117 sctp_addto_chunk(retval, sizeof(error), error); 1118 sctp_addto_param(retval, sizeof(*param), param); 1119 1120 nodata: 1121 return retval; 1122 } 1123 1124 struct sctp_chunk *sctp_make_violation_max_retrans( 1125 const struct sctp_association *asoc, 1126 const struct sctp_chunk *chunk) 1127 { 1128 struct sctp_chunk *retval; 1129 static const char error[] = "Association exceeded its max_retans count"; 1130 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr); 1131 1132 retval = sctp_make_abort(asoc, chunk, payload_len); 1133 if (!retval) 1134 goto nodata; 1135 1136 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error)); 1137 sctp_addto_chunk(retval, sizeof(error), error); 1138 1139 nodata: 1140 return retval; 1141 } 1142 1143 /* Make a HEARTBEAT chunk. */ 1144 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1145 const struct sctp_transport *transport) 1146 { 1147 struct sctp_chunk *retval; 1148 sctp_sender_hb_info_t hbinfo; 1149 1150 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, 1151 sizeof(hbinfo), GFP_ATOMIC); 1152 1153 if (!retval) 1154 goto nodata; 1155 1156 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; 1157 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t)); 1158 hbinfo.daddr = transport->ipaddr; 1159 hbinfo.sent_at = jiffies; 1160 hbinfo.hb_nonce = transport->hb_nonce; 1161 1162 /* Cast away the 'const', as this is just telling the chunk 1163 * what transport it belongs to. 1164 */ 1165 retval->transport = (struct sctp_transport *) transport; 1166 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo), 1167 &hbinfo); 1168 1169 nodata: 1170 return retval; 1171 } 1172 1173 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1174 const struct sctp_chunk *chunk, 1175 const void *payload, const size_t paylen) 1176 { 1177 struct sctp_chunk *retval; 1178 1179 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen, 1180 GFP_ATOMIC); 1181 if (!retval) 1182 goto nodata; 1183 1184 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1185 1186 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1187 * 1188 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1189 * HEARTBEAT ACK, * etc.) to the same destination transport 1190 * address from which it * received the DATA or control chunk 1191 * to which it is replying. 1192 * 1193 * [HBACK back to where the HEARTBEAT came from.] 1194 */ 1195 if (chunk) 1196 retval->transport = chunk->transport; 1197 1198 nodata: 1199 return retval; 1200 } 1201 1202 /* Create an Operation Error chunk with the specified space reserved. 1203 * This routine can be used for containing multiple causes in the chunk. 1204 */ 1205 static struct sctp_chunk *sctp_make_op_error_space( 1206 const struct sctp_association *asoc, 1207 const struct sctp_chunk *chunk, 1208 size_t size) 1209 { 1210 struct sctp_chunk *retval; 1211 1212 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0, 1213 sizeof(struct sctp_errhdr) + size, 1214 GFP_ATOMIC); 1215 if (!retval) 1216 goto nodata; 1217 1218 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1219 * 1220 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1221 * HEARTBEAT ACK, etc.) to the same destination transport 1222 * address from which it received the DATA or control chunk 1223 * to which it is replying. 1224 * 1225 */ 1226 if (chunk) 1227 retval->transport = chunk->transport; 1228 1229 nodata: 1230 return retval; 1231 } 1232 1233 /* Create an Operation Error chunk of a fixed size, 1234 * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) 1235 * This is a helper function to allocate an error chunk for 1236 * for those invalid parameter codes in which we may not want 1237 * to report all the errors, if the incoming chunk is large 1238 */ 1239 static inline struct sctp_chunk *sctp_make_op_error_fixed( 1240 const struct sctp_association *asoc, 1241 const struct sctp_chunk *chunk) 1242 { 1243 size_t size = asoc ? asoc->pathmtu : 0; 1244 1245 if (!size) 1246 size = SCTP_DEFAULT_MAXSEGMENT; 1247 1248 return sctp_make_op_error_space(asoc, chunk, size); 1249 } 1250 1251 /* Create an Operation Error chunk. */ 1252 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1253 const struct sctp_chunk *chunk, 1254 __be16 cause_code, const void *payload, 1255 size_t paylen, size_t reserve_tail) 1256 { 1257 struct sctp_chunk *retval; 1258 1259 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); 1260 if (!retval) 1261 goto nodata; 1262 1263 sctp_init_cause(retval, cause_code, paylen + reserve_tail); 1264 sctp_addto_chunk(retval, paylen, payload); 1265 if (reserve_tail) 1266 sctp_addto_param(retval, reserve_tail, NULL); 1267 1268 nodata: 1269 return retval; 1270 } 1271 1272 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc) 1273 { 1274 struct sctp_chunk *retval; 1275 struct sctp_hmac *hmac_desc; 1276 struct sctp_authhdr auth_hdr; 1277 __u8 *hmac; 1278 1279 /* Get the first hmac that the peer told us to use */ 1280 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1281 if (unlikely(!hmac_desc)) 1282 return NULL; 1283 1284 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0, 1285 hmac_desc->hmac_len + sizeof(auth_hdr), 1286 GFP_ATOMIC); 1287 if (!retval) 1288 return NULL; 1289 1290 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1291 auth_hdr.shkey_id = htons(asoc->active_key_id); 1292 1293 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr), 1294 &auth_hdr); 1295 1296 hmac = skb_put_zero(retval->skb, hmac_desc->hmac_len); 1297 1298 /* Adjust the chunk header to include the empty MAC */ 1299 retval->chunk_hdr->length = 1300 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1301 retval->chunk_end = skb_tail_pointer(retval->skb); 1302 1303 return retval; 1304 } 1305 1306 1307 /******************************************************************** 1308 * 2nd Level Abstractions 1309 ********************************************************************/ 1310 1311 /* Turn an skb into a chunk. 1312 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1313 * 1314 * sctpimpguide-05.txt Section 2.8.2 1315 * M1) Each time a new DATA chunk is transmitted 1316 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1317 * 'TSN.Missing.Report' count will be used to determine missing chunks 1318 * and when to fast retransmit. 1319 * 1320 */ 1321 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1322 const struct sctp_association *asoc, 1323 struct sock *sk, gfp_t gfp) 1324 { 1325 struct sctp_chunk *retval; 1326 1327 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp); 1328 1329 if (!retval) 1330 goto nodata; 1331 if (!sk) 1332 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb); 1333 1334 INIT_LIST_HEAD(&retval->list); 1335 retval->skb = skb; 1336 retval->asoc = (struct sctp_association *)asoc; 1337 retval->singleton = 1; 1338 1339 retval->fast_retransmit = SCTP_CAN_FRTX; 1340 1341 /* Polish the bead hole. */ 1342 INIT_LIST_HEAD(&retval->transmitted_list); 1343 INIT_LIST_HEAD(&retval->frag_list); 1344 SCTP_DBG_OBJCNT_INC(chunk); 1345 refcount_set(&retval->refcnt, 1); 1346 1347 nodata: 1348 return retval; 1349 } 1350 1351 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1352 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1353 union sctp_addr *dest) 1354 { 1355 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1356 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1357 } 1358 1359 /* Extract the source address from a chunk. */ 1360 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1361 { 1362 /* If we have a known transport, use that. */ 1363 if (chunk->transport) { 1364 return &chunk->transport->ipaddr; 1365 } else { 1366 /* Otherwise, extract it from the IP header. */ 1367 return &chunk->source; 1368 } 1369 } 1370 1371 /* Create a new chunk, setting the type and flags headers from the 1372 * arguments, reserving enough space for a 'paylen' byte payload. 1373 */ 1374 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 1375 __u8 type, __u8 flags, int paylen, 1376 gfp_t gfp) 1377 { 1378 struct sctp_chunk *retval; 1379 struct sctp_chunkhdr *chunk_hdr; 1380 struct sk_buff *skb; 1381 struct sock *sk; 1382 1383 /* No need to allocate LL here, as this is only a chunk. */ 1384 skb = alloc_skb(SCTP_PAD4(sizeof(*chunk_hdr) + paylen), gfp); 1385 if (!skb) 1386 goto nodata; 1387 1388 /* Make room for the chunk header. */ 1389 chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr)); 1390 chunk_hdr->type = type; 1391 chunk_hdr->flags = flags; 1392 chunk_hdr->length = htons(sizeof(*chunk_hdr)); 1393 1394 sk = asoc ? asoc->base.sk : NULL; 1395 retval = sctp_chunkify(skb, asoc, sk, gfp); 1396 if (!retval) { 1397 kfree_skb(skb); 1398 goto nodata; 1399 } 1400 1401 retval->chunk_hdr = chunk_hdr; 1402 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr); 1403 1404 /* Determine if the chunk needs to be authenticated */ 1405 if (sctp_auth_send_cid(type, asoc)) 1406 retval->auth = 1; 1407 1408 return retval; 1409 nodata: 1410 return NULL; 1411 } 1412 1413 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 1414 __u8 flags, int paylen, gfp_t gfp) 1415 { 1416 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp); 1417 } 1418 1419 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 1420 __u8 type, __u8 flags, int paylen, 1421 gfp_t gfp) 1422 { 1423 struct sctp_chunk *chunk; 1424 1425 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp); 1426 if (chunk) 1427 sctp_control_set_owner_w(chunk); 1428 1429 return chunk; 1430 } 1431 1432 /* Release the memory occupied by a chunk. */ 1433 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1434 { 1435 BUG_ON(!list_empty(&chunk->list)); 1436 list_del_init(&chunk->transmitted_list); 1437 1438 consume_skb(chunk->skb); 1439 consume_skb(chunk->auth_chunk); 1440 1441 SCTP_DBG_OBJCNT_DEC(chunk); 1442 kmem_cache_free(sctp_chunk_cachep, chunk); 1443 } 1444 1445 /* Possibly, free the chunk. */ 1446 void sctp_chunk_free(struct sctp_chunk *chunk) 1447 { 1448 /* Release our reference on the message tracker. */ 1449 if (chunk->msg) 1450 sctp_datamsg_put(chunk->msg); 1451 1452 sctp_chunk_put(chunk); 1453 } 1454 1455 /* Grab a reference to the chunk. */ 1456 void sctp_chunk_hold(struct sctp_chunk *ch) 1457 { 1458 refcount_inc(&ch->refcnt); 1459 } 1460 1461 /* Release a reference to the chunk. */ 1462 void sctp_chunk_put(struct sctp_chunk *ch) 1463 { 1464 if (refcount_dec_and_test(&ch->refcnt)) 1465 sctp_chunk_destroy(ch); 1466 } 1467 1468 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1469 * enough. 1470 */ 1471 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1472 { 1473 void *target; 1474 int chunklen = ntohs(chunk->chunk_hdr->length); 1475 int padlen = SCTP_PAD4(chunklen) - chunklen; 1476 1477 skb_put_zero(chunk->skb, padlen); 1478 target = skb_put_data(chunk->skb, data, len); 1479 1480 /* Adjust the chunk length field. */ 1481 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1482 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1483 1484 return target; 1485 } 1486 1487 /* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient 1488 * space in the chunk 1489 */ 1490 static void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk, 1491 int len, const void *data) 1492 { 1493 if (skb_tailroom(chunk->skb) >= len) 1494 return sctp_addto_chunk(chunk, len, data); 1495 else 1496 return NULL; 1497 } 1498 1499 /* Append bytes from user space to the end of a chunk. Will panic if 1500 * chunk is not big enough. 1501 * Returns a kernel err value. 1502 */ 1503 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len, 1504 struct iov_iter *from) 1505 { 1506 void *target; 1507 1508 /* Make room in chunk for data. */ 1509 target = skb_put(chunk->skb, len); 1510 1511 /* Copy data (whole iovec) into chunk */ 1512 if (!copy_from_iter_full(target, len, from)) 1513 return -EFAULT; 1514 1515 /* Adjust the chunk length field. */ 1516 chunk->chunk_hdr->length = 1517 htons(ntohs(chunk->chunk_hdr->length) + len); 1518 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1519 1520 return 0; 1521 } 1522 1523 /* Helper function to assign a TSN if needed. This assumes that both 1524 * the data_hdr and association have already been assigned. 1525 */ 1526 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1527 { 1528 struct sctp_datamsg *msg; 1529 struct sctp_chunk *lchunk; 1530 struct sctp_stream *stream; 1531 __u16 ssn; 1532 __u16 sid; 1533 1534 if (chunk->has_ssn) 1535 return; 1536 1537 /* All fragments will be on the same stream */ 1538 sid = ntohs(chunk->subh.data_hdr->stream); 1539 stream = &chunk->asoc->stream; 1540 1541 /* Now assign the sequence number to the entire message. 1542 * All fragments must have the same stream sequence number. 1543 */ 1544 msg = chunk->msg; 1545 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1546 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1547 ssn = 0; 1548 } else { 1549 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1550 ssn = sctp_ssn_next(stream, out, sid); 1551 else 1552 ssn = sctp_ssn_peek(stream, out, sid); 1553 } 1554 1555 lchunk->subh.data_hdr->ssn = htons(ssn); 1556 lchunk->has_ssn = 1; 1557 } 1558 } 1559 1560 /* Helper function to assign a TSN if needed. This assumes that both 1561 * the data_hdr and association have already been assigned. 1562 */ 1563 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1564 { 1565 if (!chunk->has_tsn) { 1566 /* This is the last possible instant to 1567 * assign a TSN. 1568 */ 1569 chunk->subh.data_hdr->tsn = 1570 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1571 chunk->has_tsn = 1; 1572 } 1573 } 1574 1575 /* Create a CLOSED association to use with an incoming packet. */ 1576 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1577 struct sctp_chunk *chunk, 1578 gfp_t gfp) 1579 { 1580 struct sctp_association *asoc; 1581 struct sk_buff *skb; 1582 sctp_scope_t scope; 1583 1584 /* Create the bare association. */ 1585 scope = sctp_scope(sctp_source(chunk)); 1586 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1587 if (!asoc) 1588 goto nodata; 1589 asoc->temp = 1; 1590 skb = chunk->skb; 1591 /* Create an entry for the source address of the packet. */ 1592 SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1); 1593 1594 nodata: 1595 return asoc; 1596 } 1597 1598 /* Build a cookie representing asoc. 1599 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1600 */ 1601 static struct sctp_cookie_param *sctp_pack_cookie( 1602 const struct sctp_endpoint *ep, 1603 const struct sctp_association *asoc, 1604 const struct sctp_chunk *init_chunk, 1605 int *cookie_len, 1606 const __u8 *raw_addrs, int addrs_len) 1607 { 1608 struct sctp_signed_cookie *cookie; 1609 struct sctp_cookie_param *retval; 1610 int headersize, bodysize; 1611 1612 /* Header size is static data prior to the actual cookie, including 1613 * any padding. 1614 */ 1615 headersize = sizeof(struct sctp_paramhdr) + 1616 (sizeof(struct sctp_signed_cookie) - 1617 sizeof(struct sctp_cookie)); 1618 bodysize = sizeof(struct sctp_cookie) 1619 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1620 1621 /* Pad out the cookie to a multiple to make the signature 1622 * functions simpler to write. 1623 */ 1624 if (bodysize % SCTP_COOKIE_MULTIPLE) 1625 bodysize += SCTP_COOKIE_MULTIPLE 1626 - (bodysize % SCTP_COOKIE_MULTIPLE); 1627 *cookie_len = headersize + bodysize; 1628 1629 /* Clear this memory since we are sending this data structure 1630 * out on the network. 1631 */ 1632 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1633 if (!retval) 1634 goto nodata; 1635 1636 cookie = (struct sctp_signed_cookie *) retval->body; 1637 1638 /* Set up the parameter header. */ 1639 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1640 retval->p.length = htons(*cookie_len); 1641 1642 /* Copy the cookie part of the association itself. */ 1643 cookie->c = asoc->c; 1644 /* Save the raw address list length in the cookie. */ 1645 cookie->c.raw_addr_list_len = addrs_len; 1646 1647 /* Remember PR-SCTP capability. */ 1648 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1649 1650 /* Save adaptation indication in the cookie. */ 1651 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1652 1653 /* Set an expiration time for the cookie. */ 1654 cookie->c.expiration = ktime_add(asoc->cookie_life, 1655 ktime_get_real()); 1656 1657 /* Copy the peer's init packet. */ 1658 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr, 1659 ntohs(init_chunk->chunk_hdr->length)); 1660 1661 /* Copy the raw local address list of the association. */ 1662 memcpy((__u8 *)&cookie->c.peer_init[0] + 1663 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1664 1665 if (sctp_sk(ep->base.sk)->hmac) { 1666 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac); 1667 int err; 1668 1669 /* Sign the message. */ 1670 desc->tfm = sctp_sk(ep->base.sk)->hmac; 1671 desc->flags = 0; 1672 1673 err = crypto_shash_setkey(desc->tfm, ep->secret_key, 1674 sizeof(ep->secret_key)) ?: 1675 crypto_shash_digest(desc, (u8 *)&cookie->c, bodysize, 1676 cookie->signature); 1677 shash_desc_zero(desc); 1678 if (err) 1679 goto free_cookie; 1680 } 1681 1682 return retval; 1683 1684 free_cookie: 1685 kfree(retval); 1686 nodata: 1687 *cookie_len = 0; 1688 return NULL; 1689 } 1690 1691 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1692 struct sctp_association *sctp_unpack_cookie( 1693 const struct sctp_endpoint *ep, 1694 const struct sctp_association *asoc, 1695 struct sctp_chunk *chunk, gfp_t gfp, 1696 int *error, struct sctp_chunk **errp) 1697 { 1698 struct sctp_association *retval = NULL; 1699 struct sctp_signed_cookie *cookie; 1700 struct sctp_cookie *bear_cookie; 1701 int headersize, bodysize, fixed_size; 1702 __u8 *digest = ep->digest; 1703 unsigned int len; 1704 sctp_scope_t scope; 1705 struct sk_buff *skb = chunk->skb; 1706 ktime_t kt; 1707 1708 /* Header size is static data prior to the actual cookie, including 1709 * any padding. 1710 */ 1711 headersize = sizeof(struct sctp_chunkhdr) + 1712 (sizeof(struct sctp_signed_cookie) - 1713 sizeof(struct sctp_cookie)); 1714 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1715 fixed_size = headersize + sizeof(struct sctp_cookie); 1716 1717 /* Verify that the chunk looks like it even has a cookie. 1718 * There must be enough room for our cookie and our peer's 1719 * INIT chunk. 1720 */ 1721 len = ntohs(chunk->chunk_hdr->length); 1722 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1723 goto malformed; 1724 1725 /* Verify that the cookie has been padded out. */ 1726 if (bodysize % SCTP_COOKIE_MULTIPLE) 1727 goto malformed; 1728 1729 /* Process the cookie. */ 1730 cookie = chunk->subh.cookie_hdr; 1731 bear_cookie = &cookie->c; 1732 1733 if (!sctp_sk(ep->base.sk)->hmac) 1734 goto no_hmac; 1735 1736 /* Check the signature. */ 1737 { 1738 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac); 1739 int err; 1740 1741 desc->tfm = sctp_sk(ep->base.sk)->hmac; 1742 desc->flags = 0; 1743 1744 err = crypto_shash_setkey(desc->tfm, ep->secret_key, 1745 sizeof(ep->secret_key)) ?: 1746 crypto_shash_digest(desc, (u8 *)bear_cookie, bodysize, 1747 digest); 1748 shash_desc_zero(desc); 1749 1750 if (err) { 1751 *error = -SCTP_IERROR_NOMEM; 1752 goto fail; 1753 } 1754 } 1755 1756 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1757 *error = -SCTP_IERROR_BAD_SIG; 1758 goto fail; 1759 } 1760 1761 no_hmac: 1762 /* IG Section 2.35.2: 1763 * 3) Compare the port numbers and the verification tag contained 1764 * within the COOKIE ECHO chunk to the actual port numbers and the 1765 * verification tag within the SCTP common header of the received 1766 * packet. If these values do not match the packet MUST be silently 1767 * discarded, 1768 */ 1769 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1770 *error = -SCTP_IERROR_BAD_TAG; 1771 goto fail; 1772 } 1773 1774 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1775 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1776 *error = -SCTP_IERROR_BAD_PORTS; 1777 goto fail; 1778 } 1779 1780 /* Check to see if the cookie is stale. If there is already 1781 * an association, there is no need to check cookie's expiration 1782 * for init collision case of lost COOKIE ACK. 1783 * If skb has been timestamped, then use the stamp, otherwise 1784 * use current time. This introduces a small possibility that 1785 * that a cookie may be considered expired, but his would only slow 1786 * down the new association establishment instead of every packet. 1787 */ 1788 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1789 kt = skb_get_ktime(skb); 1790 else 1791 kt = ktime_get_real(); 1792 1793 if (!asoc && ktime_before(bear_cookie->expiration, kt)) { 1794 /* 1795 * Section 3.3.10.3 Stale Cookie Error (3) 1796 * 1797 * Cause of error 1798 * --------------- 1799 * Stale Cookie Error: Indicates the receipt of a valid State 1800 * Cookie that has expired. 1801 */ 1802 len = ntohs(chunk->chunk_hdr->length); 1803 *errp = sctp_make_op_error_space(asoc, chunk, len); 1804 if (*errp) { 1805 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); 1806 __be32 n = htonl(usecs); 1807 1808 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE, 1809 sizeof(n)); 1810 sctp_addto_chunk(*errp, sizeof(n), &n); 1811 *error = -SCTP_IERROR_STALE_COOKIE; 1812 } else 1813 *error = -SCTP_IERROR_NOMEM; 1814 1815 goto fail; 1816 } 1817 1818 /* Make a new base association. */ 1819 scope = sctp_scope(sctp_source(chunk)); 1820 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1821 if (!retval) { 1822 *error = -SCTP_IERROR_NOMEM; 1823 goto fail; 1824 } 1825 1826 /* Set up our peer's port number. */ 1827 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1828 1829 /* Populate the association from the cookie. */ 1830 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1831 1832 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1833 GFP_ATOMIC) < 0) { 1834 *error = -SCTP_IERROR_NOMEM; 1835 goto fail; 1836 } 1837 1838 /* Also, add the destination address. */ 1839 if (list_empty(&retval->base.bind_addr.address_list)) { 1840 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1841 sizeof(chunk->dest), SCTP_ADDR_SRC, 1842 GFP_ATOMIC); 1843 } 1844 1845 retval->next_tsn = retval->c.initial_tsn; 1846 retval->ctsn_ack_point = retval->next_tsn - 1; 1847 retval->addip_serial = retval->c.initial_tsn; 1848 retval->strreset_outseq = retval->c.initial_tsn; 1849 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1850 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1851 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1852 1853 /* The INIT stuff will be done by the side effects. */ 1854 return retval; 1855 1856 fail: 1857 if (retval) 1858 sctp_association_free(retval); 1859 1860 return NULL; 1861 1862 malformed: 1863 /* Yikes! The packet is either corrupt or deliberately 1864 * malformed. 1865 */ 1866 *error = -SCTP_IERROR_MALFORMED; 1867 goto fail; 1868 } 1869 1870 /******************************************************************** 1871 * 3rd Level Abstractions 1872 ********************************************************************/ 1873 1874 struct __sctp_missing { 1875 __be32 num_missing; 1876 __be16 type; 1877 } __packed; 1878 1879 /* 1880 * Report a missing mandatory parameter. 1881 */ 1882 static int sctp_process_missing_param(const struct sctp_association *asoc, 1883 enum sctp_param paramtype, 1884 struct sctp_chunk *chunk, 1885 struct sctp_chunk **errp) 1886 { 1887 struct __sctp_missing report; 1888 __u16 len; 1889 1890 len = SCTP_PAD4(sizeof(report)); 1891 1892 /* Make an ERROR chunk, preparing enough room for 1893 * returning multiple unknown parameters. 1894 */ 1895 if (!*errp) 1896 *errp = sctp_make_op_error_space(asoc, chunk, len); 1897 1898 if (*errp) { 1899 report.num_missing = htonl(1); 1900 report.type = paramtype; 1901 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1902 sizeof(report)); 1903 sctp_addto_chunk(*errp, sizeof(report), &report); 1904 } 1905 1906 /* Stop processing this chunk. */ 1907 return 0; 1908 } 1909 1910 /* Report an Invalid Mandatory Parameter. */ 1911 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1912 struct sctp_chunk *chunk, 1913 struct sctp_chunk **errp) 1914 { 1915 /* Invalid Mandatory Parameter Error has no payload. */ 1916 1917 if (!*errp) 1918 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1919 1920 if (*errp) 1921 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1922 1923 /* Stop processing this chunk. */ 1924 return 0; 1925 } 1926 1927 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1928 struct sctp_paramhdr *param, 1929 const struct sctp_chunk *chunk, 1930 struct sctp_chunk **errp) 1931 { 1932 /* This is a fatal error. Any accumulated non-fatal errors are 1933 * not reported. 1934 */ 1935 if (*errp) 1936 sctp_chunk_free(*errp); 1937 1938 /* Create an error chunk and fill it in with our payload. */ 1939 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1940 1941 return 0; 1942 } 1943 1944 1945 /* Do not attempt to handle the HOST_NAME parm. However, do 1946 * send back an indicator to the peer. 1947 */ 1948 static int sctp_process_hn_param(const struct sctp_association *asoc, 1949 union sctp_params param, 1950 struct sctp_chunk *chunk, 1951 struct sctp_chunk **errp) 1952 { 1953 __u16 len = ntohs(param.p->length); 1954 1955 /* Processing of the HOST_NAME parameter will generate an 1956 * ABORT. If we've accumulated any non-fatal errors, they 1957 * would be unrecognized parameters and we should not include 1958 * them in the ABORT. 1959 */ 1960 if (*errp) 1961 sctp_chunk_free(*errp); 1962 1963 *errp = sctp_make_op_error_space(asoc, chunk, len); 1964 1965 if (*errp) { 1966 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len); 1967 sctp_addto_chunk(*errp, len, param.v); 1968 } 1969 1970 /* Stop processing this chunk. */ 1971 return 0; 1972 } 1973 1974 static int sctp_verify_ext_param(struct net *net, union sctp_params param) 1975 { 1976 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 1977 int have_auth = 0; 1978 int have_asconf = 0; 1979 int i; 1980 1981 for (i = 0; i < num_ext; i++) { 1982 switch (param.ext->chunks[i]) { 1983 case SCTP_CID_AUTH: 1984 have_auth = 1; 1985 break; 1986 case SCTP_CID_ASCONF: 1987 case SCTP_CID_ASCONF_ACK: 1988 have_asconf = 1; 1989 break; 1990 } 1991 } 1992 1993 /* ADD-IP Security: The draft requires us to ABORT or ignore the 1994 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 1995 * only if ADD-IP is turned on and we are not backward-compatible 1996 * mode. 1997 */ 1998 if (net->sctp.addip_noauth) 1999 return 1; 2000 2001 if (net->sctp.addip_enable && !have_auth && have_asconf) 2002 return 0; 2003 2004 return 1; 2005 } 2006 2007 static void sctp_process_ext_param(struct sctp_association *asoc, 2008 union sctp_params param) 2009 { 2010 struct net *net = sock_net(asoc->base.sk); 2011 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2012 int i; 2013 2014 for (i = 0; i < num_ext; i++) { 2015 switch (param.ext->chunks[i]) { 2016 case SCTP_CID_RECONF: 2017 if (asoc->reconf_enable && 2018 !asoc->peer.reconf_capable) 2019 asoc->peer.reconf_capable = 1; 2020 break; 2021 case SCTP_CID_FWD_TSN: 2022 if (asoc->prsctp_enable && !asoc->peer.prsctp_capable) 2023 asoc->peer.prsctp_capable = 1; 2024 break; 2025 case SCTP_CID_AUTH: 2026 /* if the peer reports AUTH, assume that he 2027 * supports AUTH. 2028 */ 2029 if (asoc->ep->auth_enable) 2030 asoc->peer.auth_capable = 1; 2031 break; 2032 case SCTP_CID_ASCONF: 2033 case SCTP_CID_ASCONF_ACK: 2034 if (net->sctp.addip_enable) 2035 asoc->peer.asconf_capable = 1; 2036 break; 2037 default: 2038 break; 2039 } 2040 } 2041 } 2042 2043 /* RFC 3.2.1 & the Implementers Guide 2.2. 2044 * 2045 * The Parameter Types are encoded such that the 2046 * highest-order two bits specify the action that must be 2047 * taken if the processing endpoint does not recognize the 2048 * Parameter Type. 2049 * 2050 * 00 - Stop processing this parameter; do not process any further 2051 * parameters within this chunk 2052 * 2053 * 01 - Stop processing this parameter, do not process any further 2054 * parameters within this chunk, and report the unrecognized 2055 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2056 * 2057 * 10 - Skip this parameter and continue processing. 2058 * 2059 * 11 - Skip this parameter and continue processing but 2060 * report the unrecognized parameter in an 2061 * 'Unrecognized Parameter' ERROR chunk. 2062 * 2063 * Return value: 2064 * SCTP_IERROR_NO_ERROR - continue with the chunk 2065 * SCTP_IERROR_ERROR - stop and report an error. 2066 * SCTP_IERROR_NOMEME - out of memory. 2067 */ 2068 static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc, 2069 union sctp_params param, 2070 struct sctp_chunk *chunk, 2071 struct sctp_chunk **errp) 2072 { 2073 int retval = SCTP_IERROR_NO_ERROR; 2074 2075 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2076 case SCTP_PARAM_ACTION_DISCARD: 2077 retval = SCTP_IERROR_ERROR; 2078 break; 2079 case SCTP_PARAM_ACTION_SKIP: 2080 break; 2081 case SCTP_PARAM_ACTION_DISCARD_ERR: 2082 retval = SCTP_IERROR_ERROR; 2083 /* Fall through */ 2084 case SCTP_PARAM_ACTION_SKIP_ERR: 2085 /* Make an ERROR chunk, preparing enough room for 2086 * returning multiple unknown parameters. 2087 */ 2088 if (NULL == *errp) 2089 *errp = sctp_make_op_error_fixed(asoc, chunk); 2090 2091 if (*errp) { 2092 if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2093 SCTP_PAD4(ntohs(param.p->length)))) 2094 sctp_addto_chunk_fixed(*errp, 2095 SCTP_PAD4(ntohs(param.p->length)), 2096 param.v); 2097 } else { 2098 /* If there is no memory for generating the ERROR 2099 * report as specified, an ABORT will be triggered 2100 * to the peer and the association won't be 2101 * established. 2102 */ 2103 retval = SCTP_IERROR_NOMEM; 2104 } 2105 break; 2106 default: 2107 break; 2108 } 2109 2110 return retval; 2111 } 2112 2113 /* Verify variable length parameters 2114 * Return values: 2115 * SCTP_IERROR_ABORT - trigger an ABORT 2116 * SCTP_IERROR_NOMEM - out of memory (abort) 2117 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2118 * SCTP_IERROR_NO_ERROR - continue with the chunk 2119 */ 2120 static sctp_ierror_t sctp_verify_param(struct net *net, 2121 const struct sctp_endpoint *ep, 2122 const struct sctp_association *asoc, 2123 union sctp_params param, 2124 enum sctp_cid cid, 2125 struct sctp_chunk *chunk, 2126 struct sctp_chunk **err_chunk) 2127 { 2128 struct sctp_hmac_algo_param *hmacs; 2129 int retval = SCTP_IERROR_NO_ERROR; 2130 __u16 n_elt, id = 0; 2131 int i; 2132 2133 /* FIXME - This routine is not looking at each parameter per the 2134 * chunk type, i.e., unrecognized parameters should be further 2135 * identified based on the chunk id. 2136 */ 2137 2138 switch (param.p->type) { 2139 case SCTP_PARAM_IPV4_ADDRESS: 2140 case SCTP_PARAM_IPV6_ADDRESS: 2141 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2142 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2143 case SCTP_PARAM_STATE_COOKIE: 2144 case SCTP_PARAM_HEARTBEAT_INFO: 2145 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2146 case SCTP_PARAM_ECN_CAPABLE: 2147 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2148 break; 2149 2150 case SCTP_PARAM_SUPPORTED_EXT: 2151 if (!sctp_verify_ext_param(net, param)) 2152 return SCTP_IERROR_ABORT; 2153 break; 2154 2155 case SCTP_PARAM_SET_PRIMARY: 2156 if (net->sctp.addip_enable) 2157 break; 2158 goto fallthrough; 2159 2160 case SCTP_PARAM_HOST_NAME_ADDRESS: 2161 /* Tell the peer, we won't support this param. */ 2162 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2163 retval = SCTP_IERROR_ABORT; 2164 break; 2165 2166 case SCTP_PARAM_FWD_TSN_SUPPORT: 2167 if (ep->prsctp_enable) 2168 break; 2169 goto fallthrough; 2170 2171 case SCTP_PARAM_RANDOM: 2172 if (!ep->auth_enable) 2173 goto fallthrough; 2174 2175 /* SCTP-AUTH: Secion 6.1 2176 * If the random number is not 32 byte long the association 2177 * MUST be aborted. The ABORT chunk SHOULD contain the error 2178 * cause 'Protocol Violation'. 2179 */ 2180 if (SCTP_AUTH_RANDOM_LENGTH != 2181 ntohs(param.p->length) - sizeof(struct sctp_paramhdr)) { 2182 sctp_process_inv_paramlength(asoc, param.p, 2183 chunk, err_chunk); 2184 retval = SCTP_IERROR_ABORT; 2185 } 2186 break; 2187 2188 case SCTP_PARAM_CHUNKS: 2189 if (!ep->auth_enable) 2190 goto fallthrough; 2191 2192 /* SCTP-AUTH: Section 3.2 2193 * The CHUNKS parameter MUST be included once in the INIT or 2194 * INIT-ACK chunk if the sender wants to receive authenticated 2195 * chunks. Its maximum length is 260 bytes. 2196 */ 2197 if (260 < ntohs(param.p->length)) { 2198 sctp_process_inv_paramlength(asoc, param.p, 2199 chunk, err_chunk); 2200 retval = SCTP_IERROR_ABORT; 2201 } 2202 break; 2203 2204 case SCTP_PARAM_HMAC_ALGO: 2205 if (!ep->auth_enable) 2206 goto fallthrough; 2207 2208 hmacs = (struct sctp_hmac_algo_param *)param.p; 2209 n_elt = (ntohs(param.p->length) - 2210 sizeof(struct sctp_paramhdr)) >> 1; 2211 2212 /* SCTP-AUTH: Section 6.1 2213 * The HMAC algorithm based on SHA-1 MUST be supported and 2214 * included in the HMAC-ALGO parameter. 2215 */ 2216 for (i = 0; i < n_elt; i++) { 2217 id = ntohs(hmacs->hmac_ids[i]); 2218 2219 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2220 break; 2221 } 2222 2223 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2224 sctp_process_inv_paramlength(asoc, param.p, chunk, 2225 err_chunk); 2226 retval = SCTP_IERROR_ABORT; 2227 } 2228 break; 2229 fallthrough: 2230 default: 2231 pr_debug("%s: unrecognized param:%d for chunk:%d\n", 2232 __func__, ntohs(param.p->type), cid); 2233 2234 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2235 break; 2236 } 2237 return retval; 2238 } 2239 2240 /* Verify the INIT packet before we process it. */ 2241 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 2242 const struct sctp_association *asoc, enum sctp_cid cid, 2243 struct sctp_init_chunk *peer_init, 2244 struct sctp_chunk *chunk, struct sctp_chunk **errp) 2245 { 2246 union sctp_params param; 2247 bool has_cookie = false; 2248 int result; 2249 2250 /* Check for missing mandatory parameters. Note: Initial TSN is 2251 * also mandatory, but is not checked here since the valid range 2252 * is 0..2**32-1. RFC4960, section 3.3.3. 2253 */ 2254 if (peer_init->init_hdr.num_outbound_streams == 0 || 2255 peer_init->init_hdr.num_inbound_streams == 0 || 2256 peer_init->init_hdr.init_tag == 0 || 2257 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) 2258 return sctp_process_inv_mandatory(asoc, chunk, errp); 2259 2260 sctp_walk_params(param, peer_init, init_hdr.params) { 2261 if (param.p->type == SCTP_PARAM_STATE_COOKIE) 2262 has_cookie = true; 2263 } 2264 2265 /* There is a possibility that a parameter length was bad and 2266 * in that case we would have stoped walking the parameters. 2267 * The current param.p would point at the bad one. 2268 * Current consensus on the mailing list is to generate a PROTOCOL 2269 * VIOLATION error. We build the ERROR chunk here and let the normal 2270 * error handling code build and send the packet. 2271 */ 2272 if (param.v != (void *)chunk->chunk_end) 2273 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2274 2275 /* The only missing mandatory param possible today is 2276 * the state cookie for an INIT-ACK chunk. 2277 */ 2278 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2279 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2280 chunk, errp); 2281 2282 /* Verify all the variable length parameters */ 2283 sctp_walk_params(param, peer_init, init_hdr.params) { 2284 result = sctp_verify_param(net, ep, asoc, param, cid, 2285 chunk, errp); 2286 switch (result) { 2287 case SCTP_IERROR_ABORT: 2288 case SCTP_IERROR_NOMEM: 2289 return 0; 2290 case SCTP_IERROR_ERROR: 2291 return 1; 2292 case SCTP_IERROR_NO_ERROR: 2293 default: 2294 break; 2295 } 2296 2297 } /* for (loop through all parameters) */ 2298 2299 return 1; 2300 } 2301 2302 /* Unpack the parameters in an INIT packet into an association. 2303 * Returns 0 on failure, else success. 2304 * FIXME: This is an association method. 2305 */ 2306 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2307 const union sctp_addr *peer_addr, 2308 struct sctp_init_chunk *peer_init, gfp_t gfp) 2309 { 2310 struct net *net = sock_net(asoc->base.sk); 2311 union sctp_params param; 2312 struct sctp_transport *transport; 2313 struct list_head *pos, *temp; 2314 struct sctp_af *af; 2315 union sctp_addr addr; 2316 char *cookie; 2317 int src_match = 0; 2318 2319 /* We must include the address that the INIT packet came from. 2320 * This is the only address that matters for an INIT packet. 2321 * When processing a COOKIE ECHO, we retrieve the from address 2322 * of the INIT from the cookie. 2323 */ 2324 2325 /* This implementation defaults to making the first transport 2326 * added as the primary transport. The source address seems to 2327 * be a a better choice than any of the embedded addresses. 2328 */ 2329 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2330 goto nomem; 2331 2332 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2333 src_match = 1; 2334 2335 /* Process the initialization parameters. */ 2336 sctp_walk_params(param, peer_init, init_hdr.params) { 2337 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2338 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2339 af = sctp_get_af_specific(param_type2af(param.p->type)); 2340 af->from_addr_param(&addr, param.addr, 2341 chunk->sctp_hdr->source, 0); 2342 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2343 src_match = 1; 2344 } 2345 2346 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2347 goto clean_up; 2348 } 2349 2350 /* source address of chunk may not match any valid address */ 2351 if (!src_match) 2352 goto clean_up; 2353 2354 /* AUTH: After processing the parameters, make sure that we 2355 * have all the required info to potentially do authentications. 2356 */ 2357 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2358 !asoc->peer.peer_hmacs)) 2359 asoc->peer.auth_capable = 0; 2360 2361 /* In a non-backward compatible mode, if the peer claims 2362 * support for ADD-IP but not AUTH, the ADD-IP spec states 2363 * that we MUST ABORT the association. Section 6. The section 2364 * also give us an option to silently ignore the packet, which 2365 * is what we'll do here. 2366 */ 2367 if (!net->sctp.addip_noauth && 2368 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2369 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2370 SCTP_PARAM_DEL_IP | 2371 SCTP_PARAM_SET_PRIMARY); 2372 asoc->peer.asconf_capable = 0; 2373 goto clean_up; 2374 } 2375 2376 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2377 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2378 transport = list_entry(pos, struct sctp_transport, transports); 2379 if (transport->state == SCTP_UNKNOWN) { 2380 sctp_assoc_rm_peer(asoc, transport); 2381 } 2382 } 2383 2384 /* The fixed INIT headers are always in network byte 2385 * order. 2386 */ 2387 asoc->peer.i.init_tag = 2388 ntohl(peer_init->init_hdr.init_tag); 2389 asoc->peer.i.a_rwnd = 2390 ntohl(peer_init->init_hdr.a_rwnd); 2391 asoc->peer.i.num_outbound_streams = 2392 ntohs(peer_init->init_hdr.num_outbound_streams); 2393 asoc->peer.i.num_inbound_streams = 2394 ntohs(peer_init->init_hdr.num_inbound_streams); 2395 asoc->peer.i.initial_tsn = 2396 ntohl(peer_init->init_hdr.initial_tsn); 2397 2398 asoc->strreset_inseq = asoc->peer.i.initial_tsn; 2399 2400 /* Apply the upper bounds for output streams based on peer's 2401 * number of inbound streams. 2402 */ 2403 if (asoc->c.sinit_num_ostreams > 2404 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2405 asoc->c.sinit_num_ostreams = 2406 ntohs(peer_init->init_hdr.num_inbound_streams); 2407 } 2408 2409 if (asoc->c.sinit_max_instreams > 2410 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2411 asoc->c.sinit_max_instreams = 2412 ntohs(peer_init->init_hdr.num_outbound_streams); 2413 } 2414 2415 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2416 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2417 2418 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2419 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2420 2421 /* Copy cookie in case we need to resend COOKIE-ECHO. */ 2422 cookie = asoc->peer.cookie; 2423 if (cookie) { 2424 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp); 2425 if (!asoc->peer.cookie) 2426 goto clean_up; 2427 } 2428 2429 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2430 * high (for example, implementations MAY use the size of the receiver 2431 * advertised window). 2432 */ 2433 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2434 transports) { 2435 transport->ssthresh = asoc->peer.i.a_rwnd; 2436 } 2437 2438 /* Set up the TSN tracking pieces. */ 2439 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2440 asoc->peer.i.initial_tsn, gfp)) 2441 goto clean_up; 2442 2443 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2444 * 2445 * The stream sequence number in all the streams shall start 2446 * from 0 when the association is established. Also, when the 2447 * stream sequence number reaches the value 65535 the next 2448 * stream sequence number shall be set to 0. 2449 */ 2450 2451 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams, 2452 asoc->c.sinit_max_instreams, gfp)) 2453 goto clean_up; 2454 2455 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp)) 2456 goto clean_up; 2457 2458 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2459 * 2460 * When an endpoint has an ASCONF signaled change to be sent to the 2461 * remote endpoint it should do the following: 2462 * ... 2463 * A2) A serial number should be assigned to the Chunk. The serial 2464 * number should be a monotonically increasing number. All serial 2465 * numbers are defined to be initialized at the start of the 2466 * association to the same value as the Initial TSN. 2467 */ 2468 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2469 return 1; 2470 2471 clean_up: 2472 /* Release the transport structures. */ 2473 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2474 transport = list_entry(pos, struct sctp_transport, transports); 2475 if (transport->state != SCTP_ACTIVE) 2476 sctp_assoc_rm_peer(asoc, transport); 2477 } 2478 2479 nomem: 2480 return 0; 2481 } 2482 2483 2484 /* Update asoc with the option described in param. 2485 * 2486 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2487 * 2488 * asoc is the association to update. 2489 * param is the variable length parameter to use for update. 2490 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2491 * If the current packet is an INIT we want to minimize the amount of 2492 * work we do. In particular, we should not build transport 2493 * structures for the addresses. 2494 */ 2495 static int sctp_process_param(struct sctp_association *asoc, 2496 union sctp_params param, 2497 const union sctp_addr *peer_addr, 2498 gfp_t gfp) 2499 { 2500 struct net *net = sock_net(asoc->base.sk); 2501 union sctp_addr addr; 2502 int i; 2503 __u16 sat; 2504 int retval = 1; 2505 sctp_scope_t scope; 2506 u32 stale; 2507 struct sctp_af *af; 2508 union sctp_addr_param *addr_param; 2509 struct sctp_transport *t; 2510 struct sctp_endpoint *ep = asoc->ep; 2511 2512 /* We maintain all INIT parameters in network byte order all the 2513 * time. This allows us to not worry about whether the parameters 2514 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2515 */ 2516 switch (param.p->type) { 2517 case SCTP_PARAM_IPV6_ADDRESS: 2518 if (PF_INET6 != asoc->base.sk->sk_family) 2519 break; 2520 goto do_addr_param; 2521 2522 case SCTP_PARAM_IPV4_ADDRESS: 2523 /* v4 addresses are not allowed on v6-only socket */ 2524 if (ipv6_only_sock(asoc->base.sk)) 2525 break; 2526 do_addr_param: 2527 af = sctp_get_af_specific(param_type2af(param.p->type)); 2528 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); 2529 scope = sctp_scope(peer_addr); 2530 if (sctp_in_scope(net, &addr, scope)) 2531 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2532 return 0; 2533 break; 2534 2535 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2536 if (!net->sctp.cookie_preserve_enable) 2537 break; 2538 2539 stale = ntohl(param.life->lifespan_increment); 2540 2541 /* Suggested Cookie Life span increment's unit is msec, 2542 * (1/1000sec). 2543 */ 2544 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale); 2545 break; 2546 2547 case SCTP_PARAM_HOST_NAME_ADDRESS: 2548 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__); 2549 break; 2550 2551 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2552 /* Turn off the default values first so we'll know which 2553 * ones are really set by the peer. 2554 */ 2555 asoc->peer.ipv4_address = 0; 2556 asoc->peer.ipv6_address = 0; 2557 2558 /* Assume that peer supports the address family 2559 * by which it sends a packet. 2560 */ 2561 if (peer_addr->sa.sa_family == AF_INET6) 2562 asoc->peer.ipv6_address = 1; 2563 else if (peer_addr->sa.sa_family == AF_INET) 2564 asoc->peer.ipv4_address = 1; 2565 2566 /* Cycle through address types; avoid divide by 0. */ 2567 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2568 if (sat) 2569 sat /= sizeof(__u16); 2570 2571 for (i = 0; i < sat; ++i) { 2572 switch (param.sat->types[i]) { 2573 case SCTP_PARAM_IPV4_ADDRESS: 2574 asoc->peer.ipv4_address = 1; 2575 break; 2576 2577 case SCTP_PARAM_IPV6_ADDRESS: 2578 if (PF_INET6 == asoc->base.sk->sk_family) 2579 asoc->peer.ipv6_address = 1; 2580 break; 2581 2582 case SCTP_PARAM_HOST_NAME_ADDRESS: 2583 asoc->peer.hostname_address = 1; 2584 break; 2585 2586 default: /* Just ignore anything else. */ 2587 break; 2588 } 2589 } 2590 break; 2591 2592 case SCTP_PARAM_STATE_COOKIE: 2593 asoc->peer.cookie_len = 2594 ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2595 asoc->peer.cookie = param.cookie->body; 2596 break; 2597 2598 case SCTP_PARAM_HEARTBEAT_INFO: 2599 /* Would be odd to receive, but it causes no problems. */ 2600 break; 2601 2602 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2603 /* Rejected during verify stage. */ 2604 break; 2605 2606 case SCTP_PARAM_ECN_CAPABLE: 2607 asoc->peer.ecn_capable = 1; 2608 break; 2609 2610 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2611 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2612 break; 2613 2614 case SCTP_PARAM_SET_PRIMARY: 2615 if (!net->sctp.addip_enable) 2616 goto fall_through; 2617 2618 addr_param = param.v + sizeof(struct sctp_addip_param); 2619 2620 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 2621 if (af == NULL) 2622 break; 2623 2624 af->from_addr_param(&addr, addr_param, 2625 htons(asoc->peer.port), 0); 2626 2627 /* if the address is invalid, we can't process it. 2628 * XXX: see spec for what to do. 2629 */ 2630 if (!af->addr_valid(&addr, NULL, NULL)) 2631 break; 2632 2633 t = sctp_assoc_lookup_paddr(asoc, &addr); 2634 if (!t) 2635 break; 2636 2637 sctp_assoc_set_primary(asoc, t); 2638 break; 2639 2640 case SCTP_PARAM_SUPPORTED_EXT: 2641 sctp_process_ext_param(asoc, param); 2642 break; 2643 2644 case SCTP_PARAM_FWD_TSN_SUPPORT: 2645 if (asoc->prsctp_enable) { 2646 asoc->peer.prsctp_capable = 1; 2647 break; 2648 } 2649 /* Fall Through */ 2650 goto fall_through; 2651 2652 case SCTP_PARAM_RANDOM: 2653 if (!ep->auth_enable) 2654 goto fall_through; 2655 2656 /* Save peer's random parameter */ 2657 asoc->peer.peer_random = kmemdup(param.p, 2658 ntohs(param.p->length), gfp); 2659 if (!asoc->peer.peer_random) { 2660 retval = 0; 2661 break; 2662 } 2663 break; 2664 2665 case SCTP_PARAM_HMAC_ALGO: 2666 if (!ep->auth_enable) 2667 goto fall_through; 2668 2669 /* Save peer's HMAC list */ 2670 asoc->peer.peer_hmacs = kmemdup(param.p, 2671 ntohs(param.p->length), gfp); 2672 if (!asoc->peer.peer_hmacs) { 2673 retval = 0; 2674 break; 2675 } 2676 2677 /* Set the default HMAC the peer requested*/ 2678 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2679 break; 2680 2681 case SCTP_PARAM_CHUNKS: 2682 if (!ep->auth_enable) 2683 goto fall_through; 2684 2685 asoc->peer.peer_chunks = kmemdup(param.p, 2686 ntohs(param.p->length), gfp); 2687 if (!asoc->peer.peer_chunks) 2688 retval = 0; 2689 break; 2690 fall_through: 2691 default: 2692 /* Any unrecognized parameters should have been caught 2693 * and handled by sctp_verify_param() which should be 2694 * called prior to this routine. Simply log the error 2695 * here. 2696 */ 2697 pr_debug("%s: ignoring param:%d for association:%p.\n", 2698 __func__, ntohs(param.p->type), asoc); 2699 break; 2700 } 2701 2702 return retval; 2703 } 2704 2705 /* Select a new verification tag. */ 2706 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2707 { 2708 /* I believe that this random number generator complies with RFC1750. 2709 * A tag of 0 is reserved for special cases (e.g. INIT). 2710 */ 2711 __u32 x; 2712 2713 do { 2714 get_random_bytes(&x, sizeof(__u32)); 2715 } while (x == 0); 2716 2717 return x; 2718 } 2719 2720 /* Select an initial TSN to send during startup. */ 2721 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2722 { 2723 __u32 retval; 2724 2725 get_random_bytes(&retval, sizeof(__u32)); 2726 return retval; 2727 } 2728 2729 /* 2730 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2731 * 0 1 2 3 2732 * 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 2733 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2734 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2735 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2736 * | Serial Number | 2737 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2738 * | Address Parameter | 2739 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2740 * | ASCONF Parameter #1 | 2741 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2742 * \ \ 2743 * / .... / 2744 * \ \ 2745 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2746 * | ASCONF Parameter #N | 2747 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2748 * 2749 * Address Parameter and other parameter will not be wrapped in this function 2750 */ 2751 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2752 union sctp_addr *addr, 2753 int vparam_len) 2754 { 2755 struct sctp_addiphdr asconf; 2756 struct sctp_chunk *retval; 2757 int length = sizeof(asconf) + vparam_len; 2758 union sctp_addr_param addrparam; 2759 int addrlen; 2760 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2761 2762 addrlen = af->to_addr_param(addr, &addrparam); 2763 if (!addrlen) 2764 return NULL; 2765 length += addrlen; 2766 2767 /* Create the chunk. */ 2768 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length, 2769 GFP_ATOMIC); 2770 if (!retval) 2771 return NULL; 2772 2773 asconf.serial = htonl(asoc->addip_serial++); 2774 2775 retval->subh.addip_hdr = 2776 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2777 retval->param_hdr.v = 2778 sctp_addto_chunk(retval, addrlen, &addrparam); 2779 2780 return retval; 2781 } 2782 2783 /* ADDIP 2784 * 3.2.1 Add IP Address 2785 * 0 1 2 3 2786 * 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 2787 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2788 * | Type = 0xC001 | Length = Variable | 2789 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2790 * | ASCONF-Request Correlation ID | 2791 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2792 * | Address Parameter | 2793 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2794 * 2795 * 3.2.2 Delete IP Address 2796 * 0 1 2 3 2797 * 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 2798 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2799 * | Type = 0xC002 | Length = Variable | 2800 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2801 * | ASCONF-Request Correlation ID | 2802 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2803 * | Address Parameter | 2804 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2805 * 2806 */ 2807 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2808 union sctp_addr *laddr, 2809 struct sockaddr *addrs, 2810 int addrcnt, 2811 __be16 flags) 2812 { 2813 struct sctp_addip_param param; 2814 struct sctp_chunk *retval; 2815 union sctp_addr_param addr_param; 2816 union sctp_addr *addr; 2817 void *addr_buf; 2818 struct sctp_af *af; 2819 int paramlen = sizeof(param); 2820 int addr_param_len = 0; 2821 int totallen = 0; 2822 int i; 2823 int del_pickup = 0; 2824 2825 /* Get total length of all the address parameters. */ 2826 addr_buf = addrs; 2827 for (i = 0; i < addrcnt; i++) { 2828 addr = addr_buf; 2829 af = sctp_get_af_specific(addr->v4.sin_family); 2830 addr_param_len = af->to_addr_param(addr, &addr_param); 2831 2832 totallen += paramlen; 2833 totallen += addr_param_len; 2834 2835 addr_buf += af->sockaddr_len; 2836 if (asoc->asconf_addr_del_pending && !del_pickup) { 2837 /* reuse the parameter length from the same scope one */ 2838 totallen += paramlen; 2839 totallen += addr_param_len; 2840 del_pickup = 1; 2841 2842 pr_debug("%s: picked same-scope del_pending addr, " 2843 "totallen for all addresses is %d\n", 2844 __func__, totallen); 2845 } 2846 } 2847 2848 /* Create an asconf chunk with the required length. */ 2849 retval = sctp_make_asconf(asoc, laddr, totallen); 2850 if (!retval) 2851 return NULL; 2852 2853 /* Add the address parameters to the asconf chunk. */ 2854 addr_buf = addrs; 2855 for (i = 0; i < addrcnt; i++) { 2856 addr = addr_buf; 2857 af = sctp_get_af_specific(addr->v4.sin_family); 2858 addr_param_len = af->to_addr_param(addr, &addr_param); 2859 param.param_hdr.type = flags; 2860 param.param_hdr.length = htons(paramlen + addr_param_len); 2861 param.crr_id = i; 2862 2863 sctp_addto_chunk(retval, paramlen, ¶m); 2864 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2865 2866 addr_buf += af->sockaddr_len; 2867 } 2868 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2869 addr = asoc->asconf_addr_del_pending; 2870 af = sctp_get_af_specific(addr->v4.sin_family); 2871 addr_param_len = af->to_addr_param(addr, &addr_param); 2872 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2873 param.param_hdr.length = htons(paramlen + addr_param_len); 2874 param.crr_id = i; 2875 2876 sctp_addto_chunk(retval, paramlen, ¶m); 2877 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2878 } 2879 return retval; 2880 } 2881 2882 /* ADDIP 2883 * 3.2.4 Set Primary IP Address 2884 * 0 1 2 3 2885 * 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 2886 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2887 * | Type =0xC004 | Length = Variable | 2888 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2889 * | ASCONF-Request Correlation ID | 2890 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2891 * | Address Parameter | 2892 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2893 * 2894 * Create an ASCONF chunk with Set Primary IP address parameter. 2895 */ 2896 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2897 union sctp_addr *addr) 2898 { 2899 struct sctp_addip_param param; 2900 struct sctp_chunk *retval; 2901 int len = sizeof(param); 2902 union sctp_addr_param addrparam; 2903 int addrlen; 2904 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2905 2906 addrlen = af->to_addr_param(addr, &addrparam); 2907 if (!addrlen) 2908 return NULL; 2909 len += addrlen; 2910 2911 /* Create the chunk and make asconf header. */ 2912 retval = sctp_make_asconf(asoc, addr, len); 2913 if (!retval) 2914 return NULL; 2915 2916 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2917 param.param_hdr.length = htons(len); 2918 param.crr_id = 0; 2919 2920 sctp_addto_chunk(retval, sizeof(param), ¶m); 2921 sctp_addto_chunk(retval, addrlen, &addrparam); 2922 2923 return retval; 2924 } 2925 2926 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2927 * 0 1 2 3 2928 * 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 2929 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2930 * | Type = 0x80 | Chunk Flags | Chunk Length | 2931 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2932 * | Serial Number | 2933 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2934 * | ASCONF Parameter Response#1 | 2935 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2936 * \ \ 2937 * / .... / 2938 * \ \ 2939 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2940 * | ASCONF Parameter Response#N | 2941 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2942 * 2943 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2944 */ 2945 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2946 __u32 serial, int vparam_len) 2947 { 2948 struct sctp_addiphdr asconf; 2949 struct sctp_chunk *retval; 2950 int length = sizeof(asconf) + vparam_len; 2951 2952 /* Create the chunk. */ 2953 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length, 2954 GFP_ATOMIC); 2955 if (!retval) 2956 return NULL; 2957 2958 asconf.serial = htonl(serial); 2959 2960 retval->subh.addip_hdr = 2961 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2962 2963 return retval; 2964 } 2965 2966 /* Add response parameters to an ASCONF_ACK chunk. */ 2967 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2968 __be16 err_code, 2969 struct sctp_addip_param *asconf_param) 2970 { 2971 struct sctp_addip_param ack_param; 2972 struct sctp_errhdr err_param; 2973 int asconf_param_len = 0; 2974 int err_param_len = 0; 2975 __be16 response_type; 2976 2977 if (SCTP_ERROR_NO_ERROR == err_code) { 2978 response_type = SCTP_PARAM_SUCCESS_REPORT; 2979 } else { 2980 response_type = SCTP_PARAM_ERR_CAUSE; 2981 err_param_len = sizeof(err_param); 2982 if (asconf_param) 2983 asconf_param_len = 2984 ntohs(asconf_param->param_hdr.length); 2985 } 2986 2987 /* Add Success Indication or Error Cause Indication parameter. */ 2988 ack_param.param_hdr.type = response_type; 2989 ack_param.param_hdr.length = htons(sizeof(ack_param) + 2990 err_param_len + 2991 asconf_param_len); 2992 ack_param.crr_id = crr_id; 2993 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 2994 2995 if (SCTP_ERROR_NO_ERROR == err_code) 2996 return; 2997 2998 /* Add Error Cause parameter. */ 2999 err_param.cause = err_code; 3000 err_param.length = htons(err_param_len + asconf_param_len); 3001 sctp_addto_chunk(chunk, err_param_len, &err_param); 3002 3003 /* Add the failed TLV copied from ASCONF chunk. */ 3004 if (asconf_param) 3005 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 3006 } 3007 3008 /* Process a asconf parameter. */ 3009 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 3010 struct sctp_chunk *asconf, 3011 struct sctp_addip_param *asconf_param) 3012 { 3013 struct sctp_transport *peer; 3014 struct sctp_af *af; 3015 union sctp_addr addr; 3016 union sctp_addr_param *addr_param; 3017 3018 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3019 3020 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 3021 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 3022 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 3023 return SCTP_ERROR_UNKNOWN_PARAM; 3024 3025 switch (addr_param->p.type) { 3026 case SCTP_PARAM_IPV6_ADDRESS: 3027 if (!asoc->peer.ipv6_address) 3028 return SCTP_ERROR_DNS_FAILED; 3029 break; 3030 case SCTP_PARAM_IPV4_ADDRESS: 3031 if (!asoc->peer.ipv4_address) 3032 return SCTP_ERROR_DNS_FAILED; 3033 break; 3034 default: 3035 return SCTP_ERROR_DNS_FAILED; 3036 } 3037 3038 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3039 if (unlikely(!af)) 3040 return SCTP_ERROR_DNS_FAILED; 3041 3042 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); 3043 3044 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3045 * or multicast address. 3046 * (note: wildcard is permitted and requires special handling so 3047 * make sure we check for that) 3048 */ 3049 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3050 return SCTP_ERROR_DNS_FAILED; 3051 3052 switch (asconf_param->param_hdr.type) { 3053 case SCTP_PARAM_ADD_IP: 3054 /* Section 4.2.1: 3055 * If the address 0.0.0.0 or ::0 is provided, the source 3056 * address of the packet MUST be added. 3057 */ 3058 if (af->is_any(&addr)) 3059 memcpy(&addr, &asconf->source, sizeof(addr)); 3060 3061 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3062 * request and does not have the local resources to add this 3063 * new address to the association, it MUST return an Error 3064 * Cause TLV set to the new error code 'Operation Refused 3065 * Due to Resource Shortage'. 3066 */ 3067 3068 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3069 if (!peer) 3070 return SCTP_ERROR_RSRC_LOW; 3071 3072 /* Start the heartbeat timer. */ 3073 sctp_transport_reset_hb_timer(peer); 3074 asoc->new_transport = peer; 3075 break; 3076 case SCTP_PARAM_DEL_IP: 3077 /* ADDIP 4.3 D7) If a request is received to delete the 3078 * last remaining IP address of a peer endpoint, the receiver 3079 * MUST send an Error Cause TLV with the error cause set to the 3080 * new error code 'Request to Delete Last Remaining IP Address'. 3081 */ 3082 if (asoc->peer.transport_count == 1) 3083 return SCTP_ERROR_DEL_LAST_IP; 3084 3085 /* ADDIP 4.3 D8) If a request is received to delete an IP 3086 * address which is also the source address of the IP packet 3087 * which contained the ASCONF chunk, the receiver MUST reject 3088 * this request. To reject the request the receiver MUST send 3089 * an Error Cause TLV set to the new error code 'Request to 3090 * Delete Source IP Address' 3091 */ 3092 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3093 return SCTP_ERROR_DEL_SRC_IP; 3094 3095 /* Section 4.2.2 3096 * If the address 0.0.0.0 or ::0 is provided, all 3097 * addresses of the peer except the source address of the 3098 * packet MUST be deleted. 3099 */ 3100 if (af->is_any(&addr)) { 3101 sctp_assoc_set_primary(asoc, asconf->transport); 3102 sctp_assoc_del_nonprimary_peers(asoc, 3103 asconf->transport); 3104 return SCTP_ERROR_NO_ERROR; 3105 } 3106 3107 /* If the address is not part of the association, the 3108 * ASCONF-ACK with Error Cause Indication Parameter 3109 * which including cause of Unresolvable Address should 3110 * be sent. 3111 */ 3112 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3113 if (!peer) 3114 return SCTP_ERROR_DNS_FAILED; 3115 3116 sctp_assoc_rm_peer(asoc, peer); 3117 break; 3118 case SCTP_PARAM_SET_PRIMARY: 3119 /* ADDIP Section 4.2.4 3120 * If the address 0.0.0.0 or ::0 is provided, the receiver 3121 * MAY mark the source address of the packet as its 3122 * primary. 3123 */ 3124 if (af->is_any(&addr)) 3125 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr)); 3126 3127 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3128 if (!peer) 3129 return SCTP_ERROR_DNS_FAILED; 3130 3131 sctp_assoc_set_primary(asoc, peer); 3132 break; 3133 } 3134 3135 return SCTP_ERROR_NO_ERROR; 3136 } 3137 3138 /* Verify the ASCONF packet before we process it. */ 3139 bool sctp_verify_asconf(const struct sctp_association *asoc, 3140 struct sctp_chunk *chunk, bool addr_param_needed, 3141 struct sctp_paramhdr **errp) 3142 { 3143 struct sctp_addip_chunk *addip; 3144 union sctp_params param; 3145 bool addr_param_seen = false; 3146 3147 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr; 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(struct sctp_ipv4addr_param)) 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(struct sctp_ipv6addr_param)) 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(struct sctp_addip_param) + 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(struct sctp_addip_param)) 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 struct sctp_addip_chunk *addip; 3212 bool all_param_pass = true; 3213 union sctp_params param; 3214 struct sctp_addiphdr *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 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr; 3223 chunk_len = ntohs(asconf->chunk_hdr->length) - 3224 sizeof(struct sctp_chunkhdr); 3225 hdr = (struct sctp_addiphdr *)asconf->skb->data; 3226 serial = ntohl(hdr->serial); 3227 3228 /* Skip the addiphdr and store a pointer to address parameter. */ 3229 length = sizeof(*hdr); 3230 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3231 chunk_len -= length; 3232 3233 /* Skip the address parameter and store a pointer to the first 3234 * asconf parameter. 3235 */ 3236 length = ntohs(addr_param->p.length); 3237 chunk_len -= length; 3238 3239 /* create an ASCONF_ACK chunk. 3240 * Based on the definitions of parameters, we know that the size of 3241 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3242 * parameters. 3243 */ 3244 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3245 if (!asconf_ack) 3246 goto done; 3247 3248 /* Process the TLVs contained within the ASCONF chunk. */ 3249 sctp_walk_params(param, addip, addip_hdr.params) { 3250 /* Skip preceeding address parameters. */ 3251 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 3252 param.p->type == SCTP_PARAM_IPV6_ADDRESS) 3253 continue; 3254 3255 err_code = sctp_process_asconf_param(asoc, asconf, 3256 param.addip); 3257 /* ADDIP 4.1 A7) 3258 * If an error response is received for a TLV parameter, 3259 * all TLVs with no response before the failed TLV are 3260 * considered successful if not reported. All TLVs after 3261 * the failed response are considered unsuccessful unless 3262 * a specific success indication is present for the parameter. 3263 */ 3264 if (err_code != SCTP_ERROR_NO_ERROR) 3265 all_param_pass = false; 3266 if (!all_param_pass) 3267 sctp_add_asconf_response(asconf_ack, param.addip->crr_id, 3268 err_code, param.addip); 3269 3270 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3271 * an IP address sends an 'Out of Resource' in its response, it 3272 * MUST also fail any subsequent add or delete requests bundled 3273 * in the ASCONF. 3274 */ 3275 if (err_code == SCTP_ERROR_RSRC_LOW) 3276 goto done; 3277 } 3278 done: 3279 asoc->peer.addip_serial++; 3280 3281 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3282 * after freeing the reference to old asconf ack if any. 3283 */ 3284 if (asconf_ack) { 3285 sctp_chunk_hold(asconf_ack); 3286 list_add_tail(&asconf_ack->transmitted_list, 3287 &asoc->asconf_ack_list); 3288 } 3289 3290 return asconf_ack; 3291 } 3292 3293 /* Process a asconf parameter that is successfully acked. */ 3294 static void sctp_asconf_param_success(struct sctp_association *asoc, 3295 struct sctp_addip_param *asconf_param) 3296 { 3297 struct sctp_af *af; 3298 union sctp_addr addr; 3299 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3300 union sctp_addr_param *addr_param; 3301 struct sctp_transport *transport; 3302 struct sctp_sockaddr_entry *saddr; 3303 3304 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3305 3306 /* We have checked the packet before, so we do not check again. */ 3307 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3308 af->from_addr_param(&addr, addr_param, htons(bp->port), 0); 3309 3310 switch (asconf_param->param_hdr.type) { 3311 case SCTP_PARAM_ADD_IP: 3312 /* This is always done in BH context with a socket lock 3313 * held, so the list can not change. 3314 */ 3315 local_bh_disable(); 3316 list_for_each_entry(saddr, &bp->address_list, list) { 3317 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3318 saddr->state = SCTP_ADDR_SRC; 3319 } 3320 local_bh_enable(); 3321 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3322 transports) { 3323 sctp_transport_dst_release(transport); 3324 } 3325 break; 3326 case SCTP_PARAM_DEL_IP: 3327 local_bh_disable(); 3328 sctp_del_bind_addr(bp, &addr); 3329 if (asoc->asconf_addr_del_pending != NULL && 3330 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3331 kfree(asoc->asconf_addr_del_pending); 3332 asoc->asconf_addr_del_pending = NULL; 3333 } 3334 local_bh_enable(); 3335 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3336 transports) { 3337 sctp_transport_dst_release(transport); 3338 } 3339 break; 3340 default: 3341 break; 3342 } 3343 } 3344 3345 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3346 * for the given asconf parameter. If there is no response for this parameter, 3347 * return the error code based on the third argument 'no_err'. 3348 * ADDIP 4.1 3349 * A7) If an error response is received for a TLV parameter, all TLVs with no 3350 * response before the failed TLV are considered successful if not reported. 3351 * All TLVs after the failed response are considered unsuccessful unless a 3352 * specific success indication is present for the parameter. 3353 */ 3354 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3355 struct sctp_addip_param *asconf_param, 3356 int no_err) 3357 { 3358 struct sctp_addip_param *asconf_ack_param; 3359 struct sctp_errhdr *err_param; 3360 int length; 3361 int asconf_ack_len; 3362 __be16 err_code; 3363 3364 if (no_err) 3365 err_code = SCTP_ERROR_NO_ERROR; 3366 else 3367 err_code = SCTP_ERROR_REQ_REFUSED; 3368 3369 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3370 sizeof(struct sctp_chunkhdr); 3371 3372 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3373 * the first asconf_ack parameter. 3374 */ 3375 length = sizeof(struct sctp_addiphdr); 3376 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data + 3377 length); 3378 asconf_ack_len -= length; 3379 3380 while (asconf_ack_len > 0) { 3381 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3382 switch (asconf_ack_param->param_hdr.type) { 3383 case SCTP_PARAM_SUCCESS_REPORT: 3384 return SCTP_ERROR_NO_ERROR; 3385 case SCTP_PARAM_ERR_CAUSE: 3386 length = sizeof(*asconf_ack_param); 3387 err_param = (void *)asconf_ack_param + length; 3388 asconf_ack_len -= length; 3389 if (asconf_ack_len > 0) 3390 return err_param->cause; 3391 else 3392 return SCTP_ERROR_INV_PARAM; 3393 break; 3394 default: 3395 return SCTP_ERROR_INV_PARAM; 3396 } 3397 } 3398 3399 length = ntohs(asconf_ack_param->param_hdr.length); 3400 asconf_ack_param = (void *)asconf_ack_param + length; 3401 asconf_ack_len -= length; 3402 } 3403 3404 return err_code; 3405 } 3406 3407 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3408 int sctp_process_asconf_ack(struct sctp_association *asoc, 3409 struct sctp_chunk *asconf_ack) 3410 { 3411 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3412 union sctp_addr_param *addr_param; 3413 struct sctp_addip_param *asconf_param; 3414 int length = 0; 3415 int asconf_len = asconf->skb->len; 3416 int all_param_pass = 0; 3417 int no_err = 1; 3418 int retval = 0; 3419 __be16 err_code = SCTP_ERROR_NO_ERROR; 3420 3421 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3422 * a pointer to address parameter. 3423 */ 3424 length = sizeof(struct sctp_addip_chunk); 3425 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3426 asconf_len -= length; 3427 3428 /* Skip the address parameter in the last asconf sent and store a 3429 * pointer to the first asconf parameter. 3430 */ 3431 length = ntohs(addr_param->p.length); 3432 asconf_param = (void *)addr_param + length; 3433 asconf_len -= length; 3434 3435 /* ADDIP 4.1 3436 * A8) If there is no response(s) to specific TLV parameter(s), and no 3437 * failures are indicated, then all request(s) are considered 3438 * successful. 3439 */ 3440 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr)) 3441 all_param_pass = 1; 3442 3443 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3444 while (asconf_len > 0) { 3445 if (all_param_pass) 3446 err_code = SCTP_ERROR_NO_ERROR; 3447 else { 3448 err_code = sctp_get_asconf_response(asconf_ack, 3449 asconf_param, 3450 no_err); 3451 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3452 no_err = 0; 3453 } 3454 3455 switch (err_code) { 3456 case SCTP_ERROR_NO_ERROR: 3457 sctp_asconf_param_success(asoc, asconf_param); 3458 break; 3459 3460 case SCTP_ERROR_RSRC_LOW: 3461 retval = 1; 3462 break; 3463 3464 case SCTP_ERROR_UNKNOWN_PARAM: 3465 /* Disable sending this type of asconf parameter in 3466 * future. 3467 */ 3468 asoc->peer.addip_disabled_mask |= 3469 asconf_param->param_hdr.type; 3470 break; 3471 3472 case SCTP_ERROR_REQ_REFUSED: 3473 case SCTP_ERROR_DEL_LAST_IP: 3474 case SCTP_ERROR_DEL_SRC_IP: 3475 default: 3476 break; 3477 } 3478 3479 /* Skip the processed asconf parameter and move to the next 3480 * one. 3481 */ 3482 length = ntohs(asconf_param->param_hdr.length); 3483 asconf_param = (void *)asconf_param + length; 3484 asconf_len -= length; 3485 } 3486 3487 if (no_err && asoc->src_out_of_asoc_ok) { 3488 asoc->src_out_of_asoc_ok = 0; 3489 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3490 } 3491 3492 /* Free the cached last sent asconf chunk. */ 3493 list_del_init(&asconf->transmitted_list); 3494 sctp_chunk_free(asconf); 3495 asoc->addip_last_asconf = NULL; 3496 3497 return retval; 3498 } 3499 3500 /* Make a FWD TSN chunk. */ 3501 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3502 __u32 new_cum_tsn, size_t nstreams, 3503 struct sctp_fwdtsn_skip *skiplist) 3504 { 3505 struct sctp_chunk *retval = NULL; 3506 struct sctp_fwdtsn_hdr ftsn_hdr; 3507 struct sctp_fwdtsn_skip skip; 3508 size_t hint; 3509 int i; 3510 3511 hint = (nstreams + 1) * sizeof(__u32); 3512 3513 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC); 3514 3515 if (!retval) 3516 return NULL; 3517 3518 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3519 retval->subh.fwdtsn_hdr = 3520 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3521 3522 for (i = 0; i < nstreams; i++) { 3523 skip.stream = skiplist[i].stream; 3524 skip.ssn = skiplist[i].ssn; 3525 sctp_addto_chunk(retval, sizeof(skip), &skip); 3526 } 3527 3528 return retval; 3529 } 3530 3531 /* RE-CONFIG 3.1 (RE-CONFIG chunk) 3532 * 0 1 2 3 3533 * 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 3534 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3535 * | Type = 130 | Chunk Flags | Chunk Length | 3536 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3537 * \ \ 3538 * / Re-configuration Parameter / 3539 * \ \ 3540 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3541 * \ \ 3542 * / Re-configuration Parameter (optional) / 3543 * \ \ 3544 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3545 */ 3546 static struct sctp_chunk *sctp_make_reconf( 3547 const struct sctp_association *asoc, 3548 int length) 3549 { 3550 struct sctp_reconf_chunk *reconf; 3551 struct sctp_chunk *retval; 3552 3553 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length, 3554 GFP_ATOMIC); 3555 if (!retval) 3556 return NULL; 3557 3558 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr; 3559 retval->param_hdr.v = reconf->params; 3560 3561 return retval; 3562 } 3563 3564 /* RE-CONFIG 4.1 (STREAM OUT RESET) 3565 * 0 1 2 3 3566 * 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 3567 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3568 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N | 3569 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3570 * | Re-configuration Request Sequence Number | 3571 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3572 * | Re-configuration Response Sequence Number | 3573 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3574 * | Sender's Last Assigned TSN | 3575 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3576 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3577 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3578 * / ...... / 3579 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3580 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3581 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3582 * 3583 * RE-CONFIG 4.2 (STREAM IN RESET) 3584 * 0 1 2 3 3585 * 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 3586 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3587 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N | 3588 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3589 * | Re-configuration Request Sequence Number | 3590 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3591 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3592 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3593 * / ...... / 3594 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3595 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3596 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3597 */ 3598 struct sctp_chunk *sctp_make_strreset_req( 3599 const struct sctp_association *asoc, 3600 __u16 stream_num, __u16 *stream_list, 3601 bool out, bool in) 3602 { 3603 struct sctp_strreset_outreq outreq; 3604 __u16 stream_len = stream_num * 2; 3605 struct sctp_strreset_inreq inreq; 3606 struct sctp_chunk *retval; 3607 __u16 outlen, inlen; 3608 3609 outlen = (sizeof(outreq) + stream_len) * out; 3610 inlen = (sizeof(inreq) + stream_len) * in; 3611 3612 retval = sctp_make_reconf(asoc, outlen + inlen); 3613 if (!retval) 3614 return NULL; 3615 3616 if (outlen) { 3617 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST; 3618 outreq.param_hdr.length = htons(outlen); 3619 outreq.request_seq = htonl(asoc->strreset_outseq); 3620 outreq.response_seq = htonl(asoc->strreset_inseq - 1); 3621 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1); 3622 3623 sctp_addto_chunk(retval, sizeof(outreq), &outreq); 3624 3625 if (stream_len) 3626 sctp_addto_chunk(retval, stream_len, stream_list); 3627 } 3628 3629 if (inlen) { 3630 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST; 3631 inreq.param_hdr.length = htons(inlen); 3632 inreq.request_seq = htonl(asoc->strreset_outseq + out); 3633 3634 sctp_addto_chunk(retval, sizeof(inreq), &inreq); 3635 3636 if (stream_len) 3637 sctp_addto_chunk(retval, stream_len, stream_list); 3638 } 3639 3640 return retval; 3641 } 3642 3643 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL) 3644 * 0 1 2 3 3645 * 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 3646 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3647 * | Parameter Type = 15 | Parameter Length = 8 | 3648 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3649 * | Re-configuration Request Sequence Number | 3650 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3651 */ 3652 struct sctp_chunk *sctp_make_strreset_tsnreq( 3653 const struct sctp_association *asoc) 3654 { 3655 struct sctp_strreset_tsnreq tsnreq; 3656 __u16 length = sizeof(tsnreq); 3657 struct sctp_chunk *retval; 3658 3659 retval = sctp_make_reconf(asoc, length); 3660 if (!retval) 3661 return NULL; 3662 3663 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST; 3664 tsnreq.param_hdr.length = htons(length); 3665 tsnreq.request_seq = htonl(asoc->strreset_outseq); 3666 3667 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq); 3668 3669 return retval; 3670 } 3671 3672 /* RE-CONFIG 4.5/4.6 (ADD STREAM) 3673 * 0 1 2 3 3674 * 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 3675 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3676 * | Parameter Type = 17 | Parameter Length = 12 | 3677 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3678 * | Re-configuration Request Sequence Number | 3679 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3680 * | Number of new streams | Reserved | 3681 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3682 */ 3683 struct sctp_chunk *sctp_make_strreset_addstrm( 3684 const struct sctp_association *asoc, 3685 __u16 out, __u16 in) 3686 { 3687 struct sctp_strreset_addstrm addstrm; 3688 __u16 size = sizeof(addstrm); 3689 struct sctp_chunk *retval; 3690 3691 retval = sctp_make_reconf(asoc, (!!out + !!in) * size); 3692 if (!retval) 3693 return NULL; 3694 3695 if (out) { 3696 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS; 3697 addstrm.param_hdr.length = htons(size); 3698 addstrm.number_of_streams = htons(out); 3699 addstrm.request_seq = htonl(asoc->strreset_outseq); 3700 addstrm.reserved = 0; 3701 3702 sctp_addto_chunk(retval, size, &addstrm); 3703 } 3704 3705 if (in) { 3706 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS; 3707 addstrm.param_hdr.length = htons(size); 3708 addstrm.number_of_streams = htons(in); 3709 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out); 3710 addstrm.reserved = 0; 3711 3712 sctp_addto_chunk(retval, size, &addstrm); 3713 } 3714 3715 return retval; 3716 } 3717 3718 /* RE-CONFIG 4.4 (RESP) 3719 * 0 1 2 3 3720 * 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 3721 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3722 * | Parameter Type = 16 | Parameter Length | 3723 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3724 * | Re-configuration Response Sequence Number | 3725 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3726 * | Result | 3727 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3728 */ 3729 struct sctp_chunk *sctp_make_strreset_resp( 3730 const struct sctp_association *asoc, 3731 __u32 result, __u32 sn) 3732 { 3733 struct sctp_strreset_resp resp; 3734 __u16 length = sizeof(resp); 3735 struct sctp_chunk *retval; 3736 3737 retval = sctp_make_reconf(asoc, length); 3738 if (!retval) 3739 return NULL; 3740 3741 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3742 resp.param_hdr.length = htons(length); 3743 resp.response_seq = htonl(sn); 3744 resp.result = htonl(result); 3745 3746 sctp_addto_chunk(retval, sizeof(resp), &resp); 3747 3748 return retval; 3749 } 3750 3751 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP) 3752 * 0 1 2 3 3753 * 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 3754 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3755 * | Parameter Type = 16 | Parameter Length | 3756 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3757 * | Re-configuration Response Sequence Number | 3758 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3759 * | Result | 3760 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3761 * | Sender's Next TSN (optional) | 3762 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3763 * | Receiver's Next TSN (optional) | 3764 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3765 */ 3766 struct sctp_chunk *sctp_make_strreset_tsnresp( 3767 struct sctp_association *asoc, 3768 __u32 result, __u32 sn, 3769 __u32 sender_tsn, __u32 receiver_tsn) 3770 { 3771 struct sctp_strreset_resptsn tsnresp; 3772 __u16 length = sizeof(tsnresp); 3773 struct sctp_chunk *retval; 3774 3775 retval = sctp_make_reconf(asoc, length); 3776 if (!retval) 3777 return NULL; 3778 3779 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3780 tsnresp.param_hdr.length = htons(length); 3781 3782 tsnresp.response_seq = htonl(sn); 3783 tsnresp.result = htonl(result); 3784 tsnresp.senders_next_tsn = htonl(sender_tsn); 3785 tsnresp.receivers_next_tsn = htonl(receiver_tsn); 3786 3787 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp); 3788 3789 return retval; 3790 } 3791 3792 bool sctp_verify_reconf(const struct sctp_association *asoc, 3793 struct sctp_chunk *chunk, 3794 struct sctp_paramhdr **errp) 3795 { 3796 struct sctp_reconf_chunk *hdr; 3797 union sctp_params param; 3798 __u16 last = 0, cnt = 0; 3799 3800 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; 3801 sctp_walk_params(param, hdr, params) { 3802 __u16 length = ntohs(param.p->length); 3803 3804 *errp = param.p; 3805 if (cnt++ > 2) 3806 return false; 3807 switch (param.p->type) { 3808 case SCTP_PARAM_RESET_OUT_REQUEST: 3809 if (length < sizeof(struct sctp_strreset_outreq) || 3810 (last && last != SCTP_PARAM_RESET_RESPONSE && 3811 last != SCTP_PARAM_RESET_IN_REQUEST)) 3812 return false; 3813 break; 3814 case SCTP_PARAM_RESET_IN_REQUEST: 3815 if (length < sizeof(struct sctp_strreset_inreq) || 3816 (last && last != SCTP_PARAM_RESET_OUT_REQUEST)) 3817 return false; 3818 break; 3819 case SCTP_PARAM_RESET_RESPONSE: 3820 if ((length != sizeof(struct sctp_strreset_resp) && 3821 length != sizeof(struct sctp_strreset_resptsn)) || 3822 (last && last != SCTP_PARAM_RESET_RESPONSE && 3823 last != SCTP_PARAM_RESET_OUT_REQUEST)) 3824 return false; 3825 break; 3826 case SCTP_PARAM_RESET_TSN_REQUEST: 3827 if (length != 3828 sizeof(struct sctp_strreset_tsnreq) || last) 3829 return false; 3830 break; 3831 case SCTP_PARAM_RESET_ADD_IN_STREAMS: 3832 if (length != sizeof(struct sctp_strreset_addstrm) || 3833 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS)) 3834 return false; 3835 break; 3836 case SCTP_PARAM_RESET_ADD_OUT_STREAMS: 3837 if (length != sizeof(struct sctp_strreset_addstrm) || 3838 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS)) 3839 return false; 3840 break; 3841 default: 3842 return false; 3843 } 3844 3845 last = param.p->type; 3846 } 3847 3848 return true; 3849 } 3850