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 <linux/types.h> 49 #include <linux/kernel.h> 50 #include <linux/ip.h> 51 #include <linux/ipv6.h> 52 #include <linux/net.h> 53 #include <linux/inet.h> 54 #include <linux/scatterlist.h> 55 #include <linux/crypto.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 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 67 __u8 flags, int paylen); 68 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 69 __u8 type, __u8 flags, int paylen); 70 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, 71 const struct sctp_association *asoc, 72 const struct sctp_chunk *init_chunk, 73 int *cookie_len, 74 const __u8 *raw_addrs, int addrs_len); 75 static int sctp_process_param(struct sctp_association *asoc, 76 union sctp_params param, 77 const union sctp_addr *peer_addr, 78 gfp_t gfp); 79 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 80 const void *data); 81 static void *sctp_addto_chunk_fixed(struct sctp_chunk *, int len, 82 const void *data); 83 84 /* Control chunk destructor */ 85 static void sctp_control_release_owner(struct sk_buff *skb) 86 { 87 /*TODO: do memory release */ 88 } 89 90 static void sctp_control_set_owner_w(struct sctp_chunk *chunk) 91 { 92 struct sctp_association *asoc = chunk->asoc; 93 struct sk_buff *skb = chunk->skb; 94 95 /* TODO: properly account for control chunks. 96 * To do it right we'll need: 97 * 1) endpoint if association isn't known. 98 * 2) proper memory accounting. 99 * 100 * For now don't do anything for now. 101 */ 102 skb->sk = asoc ? asoc->base.sk : NULL; 103 skb->destructor = sctp_control_release_owner; 104 } 105 106 /* What was the inbound interface for this chunk? */ 107 int sctp_chunk_iif(const struct sctp_chunk *chunk) 108 { 109 struct sctp_af *af; 110 int iif = 0; 111 112 af = sctp_get_af_specific(ipver2af(ip_hdr(chunk->skb)->version)); 113 if (af) 114 iif = af->skb_iif(chunk->skb); 115 116 return iif; 117 } 118 119 /* RFC 2960 3.3.2 Initiation (INIT) (1) 120 * 121 * Note 2: The ECN capable field is reserved for future use of 122 * Explicit Congestion Notification. 123 */ 124 static const struct sctp_paramhdr ecap_param = { 125 SCTP_PARAM_ECN_CAPABLE, 126 cpu_to_be16(sizeof(struct sctp_paramhdr)), 127 }; 128 static const struct sctp_paramhdr prsctp_param = { 129 SCTP_PARAM_FWD_TSN_SUPPORT, 130 cpu_to_be16(sizeof(struct sctp_paramhdr)), 131 }; 132 133 /* A helper to initialize an op error inside a 134 * provided chunk, as most cause codes will be embedded inside an 135 * abort chunk. 136 */ 137 void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, 138 size_t paylen) 139 { 140 sctp_errhdr_t err; 141 __u16 len; 142 143 /* Cause code constants are now defined in network order. */ 144 err.cause = cause_code; 145 len = sizeof(sctp_errhdr_t) + paylen; 146 err.length = htons(len); 147 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err); 148 } 149 150 /* A helper to initialize an op error inside a 151 * provided chunk, as most cause codes will be embedded inside an 152 * abort chunk. Differs from sctp_init_cause in that it won't oops 153 * if there isn't enough space in the op error chunk 154 */ 155 static int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code, 156 size_t paylen) 157 { 158 sctp_errhdr_t err; 159 __u16 len; 160 161 /* Cause code constants are now defined in network order. */ 162 err.cause = cause_code; 163 len = sizeof(sctp_errhdr_t) + paylen; 164 err.length = htons(len); 165 166 if (skb_tailroom(chunk->skb) < len) 167 return -ENOSPC; 168 chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk, 169 sizeof(sctp_errhdr_t), 170 &err); 171 return 0; 172 } 173 /* 3.3.2 Initiation (INIT) (1) 174 * 175 * This chunk is used to initiate a SCTP association between two 176 * endpoints. The format of the INIT chunk is shown below: 177 * 178 * 0 1 2 3 179 * 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 1 180 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 181 * | Type = 1 | Chunk Flags | Chunk Length | 182 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 183 * | Initiate Tag | 184 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 185 * | Advertised Receiver Window Credit (a_rwnd) | 186 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 187 * | Number of Outbound Streams | Number of Inbound Streams | 188 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 189 * | Initial TSN | 190 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 191 * \ \ 192 * / Optional/Variable-Length Parameters / 193 * \ \ 194 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 195 * 196 * 197 * The INIT chunk contains the following parameters. Unless otherwise 198 * noted, each parameter MUST only be included once in the INIT chunk. 199 * 200 * Fixed Parameters Status 201 * ---------------------------------------------- 202 * Initiate Tag Mandatory 203 * Advertised Receiver Window Credit Mandatory 204 * Number of Outbound Streams Mandatory 205 * Number of Inbound Streams Mandatory 206 * Initial TSN Mandatory 207 * 208 * Variable Parameters Status Type Value 209 * ------------------------------------------------------------- 210 * IPv4 Address (Note 1) Optional 5 211 * IPv6 Address (Note 1) Optional 6 212 * Cookie Preservative Optional 9 213 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000) 214 * Host Name Address (Note 3) Optional 11 215 * Supported Address Types (Note 4) Optional 12 216 */ 217 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc, 218 const struct sctp_bind_addr *bp, 219 gfp_t gfp, int vparam_len) 220 { 221 struct net *net = sock_net(asoc->base.sk); 222 struct sctp_endpoint *ep = asoc->ep; 223 sctp_inithdr_t init; 224 union sctp_params addrs; 225 size_t chunksize; 226 struct sctp_chunk *retval = NULL; 227 int num_types, addrs_len = 0; 228 struct sctp_sock *sp; 229 sctp_supported_addrs_param_t sat; 230 __be16 types[2]; 231 sctp_adaptation_ind_param_t aiparam; 232 sctp_supported_ext_param_t ext_param; 233 int num_ext = 0; 234 __u8 extensions[3]; 235 sctp_paramhdr_t *auth_chunks = NULL, 236 *auth_hmacs = NULL; 237 238 /* RFC 2960 3.3.2 Initiation (INIT) (1) 239 * 240 * Note 1: The INIT chunks can contain multiple addresses that 241 * can be IPv4 and/or IPv6 in any combination. 242 */ 243 retval = NULL; 244 245 /* Convert the provided bind address list to raw format. */ 246 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp); 247 248 init.init_tag = htonl(asoc->c.my_vtag); 249 init.a_rwnd = htonl(asoc->rwnd); 250 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 251 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 252 init.initial_tsn = htonl(asoc->c.initial_tsn); 253 254 /* How many address types are needed? */ 255 sp = sctp_sk(asoc->base.sk); 256 num_types = sp->pf->supported_addrs(sp, types); 257 258 chunksize = sizeof(init) + addrs_len; 259 chunksize += WORD_ROUND(SCTP_SAT_LEN(num_types)); 260 chunksize += sizeof(ecap_param); 261 262 if (net->sctp.prsctp_enable) 263 chunksize += sizeof(prsctp_param); 264 265 /* ADDIP: Section 4.2.7: 266 * An implementation supporting this extension [ADDIP] MUST list 267 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and 268 * INIT-ACK parameters. 269 */ 270 if (net->sctp.addip_enable) { 271 extensions[num_ext] = SCTP_CID_ASCONF; 272 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 273 num_ext += 2; 274 } 275 276 if (sp->adaptation_ind) 277 chunksize += sizeof(aiparam); 278 279 chunksize += vparam_len; 280 281 /* Account for AUTH related parameters */ 282 if (ep->auth_enable) { 283 /* Add random parameter length*/ 284 chunksize += sizeof(asoc->c.auth_random); 285 286 /* Add HMACS parameter length if any were defined */ 287 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs; 288 if (auth_hmacs->length) 289 chunksize += WORD_ROUND(ntohs(auth_hmacs->length)); 290 else 291 auth_hmacs = NULL; 292 293 /* Add CHUNKS parameter length */ 294 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks; 295 if (auth_chunks->length) 296 chunksize += WORD_ROUND(ntohs(auth_chunks->length)); 297 else 298 auth_chunks = NULL; 299 300 extensions[num_ext] = SCTP_CID_AUTH; 301 num_ext += 1; 302 } 303 304 /* If we have any extensions to report, account for that */ 305 if (num_ext) 306 chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) + 307 num_ext); 308 309 /* RFC 2960 3.3.2 Initiation (INIT) (1) 310 * 311 * Note 3: An INIT chunk MUST NOT contain more than one Host 312 * Name address parameter. Moreover, the sender of the INIT 313 * MUST NOT combine any other address types with the Host Name 314 * address in the INIT. The receiver of INIT MUST ignore any 315 * other address types if the Host Name address parameter is 316 * present in the received INIT chunk. 317 * 318 * PLEASE DO NOT FIXME [This version does not support Host Name.] 319 */ 320 321 retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize); 322 if (!retval) 323 goto nodata; 324 325 retval->subh.init_hdr = 326 sctp_addto_chunk(retval, sizeof(init), &init); 327 retval->param_hdr.v = 328 sctp_addto_chunk(retval, addrs_len, addrs.v); 329 330 /* RFC 2960 3.3.2 Initiation (INIT) (1) 331 * 332 * Note 4: This parameter, when present, specifies all the 333 * address types the sending endpoint can support. The absence 334 * of this parameter indicates that the sending endpoint can 335 * support any address type. 336 */ 337 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES; 338 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types)); 339 sctp_addto_chunk(retval, sizeof(sat), &sat); 340 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types); 341 342 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 343 344 /* Add the supported extensions parameter. Be nice and add this 345 * fist before addiding the parameters for the extensions themselves 346 */ 347 if (num_ext) { 348 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 349 ext_param.param_hdr.length = 350 htons(sizeof(sctp_supported_ext_param_t) + num_ext); 351 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t), 352 &ext_param); 353 sctp_addto_param(retval, num_ext, extensions); 354 } 355 356 if (net->sctp.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 sctp_inithdr_t initack; 387 struct sctp_chunk *retval; 388 union sctp_params addrs; 389 struct sctp_sock *sp; 390 int addrs_len; 391 sctp_cookie_param_t *cookie; 392 int cookie_len; 393 size_t chunksize; 394 sctp_adaptation_ind_param_t aiparam; 395 sctp_supported_ext_param_t ext_param; 396 int num_ext = 0; 397 __u8 extensions[3]; 398 sctp_paramhdr_t *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 (sp->adaptation_ind) 441 chunksize += sizeof(aiparam); 442 443 if (asoc->peer.auth_capable) { 444 auth_random = (sctp_paramhdr_t *)asoc->c.auth_random; 445 chunksize += ntohs(auth_random->length); 446 447 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs; 448 if (auth_hmacs->length) 449 chunksize += WORD_ROUND(ntohs(auth_hmacs->length)); 450 else 451 auth_hmacs = NULL; 452 453 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks; 454 if (auth_chunks->length) 455 chunksize += WORD_ROUND(ntohs(auth_chunks->length)); 456 else 457 auth_chunks = NULL; 458 459 extensions[num_ext] = SCTP_CID_AUTH; 460 num_ext += 1; 461 } 462 463 if (num_ext) 464 chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) + 465 num_ext); 466 467 /* Now allocate and fill out the chunk. */ 468 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize); 469 if (!retval) 470 goto nomem_chunk; 471 472 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 473 * 474 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 475 * HEARTBEAT ACK, * etc.) to the same destination transport 476 * address from which it received the DATA or control chunk 477 * to which it is replying. 478 * 479 * [INIT ACK back to where the INIT came from.] 480 */ 481 retval->transport = chunk->transport; 482 483 retval->subh.init_hdr = 484 sctp_addto_chunk(retval, sizeof(initack), &initack); 485 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); 486 sctp_addto_chunk(retval, cookie_len, cookie); 487 if (asoc->peer.ecn_capable) 488 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 489 if (num_ext) { 490 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 491 ext_param.param_hdr.length = 492 htons(sizeof(sctp_supported_ext_param_t) + num_ext); 493 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t), 494 &ext_param); 495 sctp_addto_param(retval, num_ext, extensions); 496 } 497 if (asoc->peer.prsctp_capable) 498 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 499 500 if (sp->adaptation_ind) { 501 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 502 aiparam.param_hdr.length = htons(sizeof(aiparam)); 503 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 504 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 505 } 506 507 if (asoc->peer.auth_capable) { 508 sctp_addto_chunk(retval, ntohs(auth_random->length), 509 auth_random); 510 if (auth_hmacs) 511 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 512 auth_hmacs); 513 if (auth_chunks) 514 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 515 auth_chunks); 516 } 517 518 /* We need to remove the const qualifier at this point. */ 519 retval->asoc = (struct sctp_association *) asoc; 520 521 nomem_chunk: 522 kfree(cookie); 523 nomem_cookie: 524 kfree(addrs.v); 525 return retval; 526 } 527 528 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10): 529 * 530 * This chunk is used only during the initialization of an association. 531 * It is sent by the initiator of an association to its peer to complete 532 * the initialization process. This chunk MUST precede any DATA chunk 533 * sent within the association, but MAY be bundled with one or more DATA 534 * chunks in the same packet. 535 * 536 * 0 1 2 3 537 * 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 1 538 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 539 * | Type = 10 |Chunk Flags | Length | 540 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 541 * / Cookie / 542 * \ \ 543 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 544 * 545 * Chunk Flags: 8 bit 546 * 547 * Set to zero on transmit and ignored on receipt. 548 * 549 * Length: 16 bits (unsigned integer) 550 * 551 * Set to the size of the chunk in bytes, including the 4 bytes of 552 * the chunk header and the size of the Cookie. 553 * 554 * Cookie: variable size 555 * 556 * This field must contain the exact cookie received in the 557 * State Cookie parameter from the previous INIT ACK. 558 * 559 * An implementation SHOULD make the cookie as small as possible 560 * to insure interoperability. 561 */ 562 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, 563 const struct sctp_chunk *chunk) 564 { 565 struct sctp_chunk *retval; 566 void *cookie; 567 int cookie_len; 568 569 cookie = asoc->peer.cookie; 570 cookie_len = asoc->peer.cookie_len; 571 572 /* Build a cookie echo chunk. */ 573 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0, cookie_len); 574 if (!retval) 575 goto nodata; 576 retval->subh.cookie_hdr = 577 sctp_addto_chunk(retval, cookie_len, cookie); 578 579 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 580 * 581 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 582 * HEARTBEAT ACK, * etc.) to the same destination transport 583 * address from which it * received the DATA or control chunk 584 * to which it is replying. 585 * 586 * [COOKIE ECHO back to where the INIT ACK came from.] 587 */ 588 if (chunk) 589 retval->transport = chunk->transport; 590 591 nodata: 592 return retval; 593 } 594 595 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11): 596 * 597 * This chunk is used only during the initialization of an 598 * association. It is used to acknowledge the receipt of a COOKIE 599 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent 600 * within the association, but MAY be bundled with one or more DATA 601 * chunks or SACK chunk in the same SCTP packet. 602 * 603 * 0 1 2 3 604 * 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 1 605 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 606 * | Type = 11 |Chunk Flags | Length = 4 | 607 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 608 * 609 * Chunk Flags: 8 bits 610 * 611 * Set to zero on transmit and ignored on receipt. 612 */ 613 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, 614 const struct sctp_chunk *chunk) 615 { 616 struct sctp_chunk *retval; 617 618 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0); 619 620 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 621 * 622 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 623 * HEARTBEAT ACK, * etc.) to the same destination transport 624 * address from which it * received the DATA or control chunk 625 * to which it is replying. 626 * 627 * [COOKIE ACK back to where the COOKIE ECHO came from.] 628 */ 629 if (retval && chunk) 630 retval->transport = chunk->transport; 631 632 return retval; 633 } 634 635 /* 636 * Appendix A: Explicit Congestion Notification: 637 * CWR: 638 * 639 * RFC 2481 details a specific bit for a sender to send in the header of 640 * its next outbound TCP segment to indicate to its peer that it has 641 * reduced its congestion window. This is termed the CWR bit. For 642 * SCTP the same indication is made by including the CWR chunk. 643 * This chunk contains one data element, i.e. the TSN number that 644 * was sent in the ECNE chunk. This element represents the lowest 645 * TSN number in the datagram that was originally marked with the 646 * CE bit. 647 * 648 * 0 1 2 3 649 * 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 1 650 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 651 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 | 652 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 653 * | Lowest TSN Number | 654 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 655 * 656 * Note: The CWR is considered a Control chunk. 657 */ 658 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, 659 const __u32 lowest_tsn, 660 const struct sctp_chunk *chunk) 661 { 662 struct sctp_chunk *retval; 663 sctp_cwrhdr_t cwr; 664 665 cwr.lowest_tsn = htonl(lowest_tsn); 666 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0, 667 sizeof(sctp_cwrhdr_t)); 668 669 if (!retval) 670 goto nodata; 671 672 retval->subh.ecn_cwr_hdr = 673 sctp_addto_chunk(retval, sizeof(cwr), &cwr); 674 675 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 676 * 677 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 678 * HEARTBEAT ACK, * etc.) to the same destination transport 679 * address from which it * received the DATA or control chunk 680 * to which it is replying. 681 * 682 * [Report a reduced congestion window back to where the ECNE 683 * came from.] 684 */ 685 if (chunk) 686 retval->transport = chunk->transport; 687 688 nodata: 689 return retval; 690 } 691 692 /* Make an ECNE chunk. This is a congestion experienced report. */ 693 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, 694 const __u32 lowest_tsn) 695 { 696 struct sctp_chunk *retval; 697 sctp_ecnehdr_t ecne; 698 699 ecne.lowest_tsn = htonl(lowest_tsn); 700 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0, 701 sizeof(sctp_ecnehdr_t)); 702 if (!retval) 703 goto nodata; 704 retval->subh.ecne_hdr = 705 sctp_addto_chunk(retval, sizeof(ecne), &ecne); 706 707 nodata: 708 return retval; 709 } 710 711 /* Make a DATA chunk for the given association from the provided 712 * parameters. However, do not populate the data payload. 713 */ 714 struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc, 715 const struct sctp_sndrcvinfo *sinfo, 716 int data_len, __u8 flags, __u16 ssn) 717 { 718 struct sctp_chunk *retval; 719 struct sctp_datahdr dp; 720 int chunk_len; 721 722 /* We assign the TSN as LATE as possible, not here when 723 * creating the chunk. 724 */ 725 dp.tsn = 0; 726 dp.stream = htons(sinfo->sinfo_stream); 727 dp.ppid = sinfo->sinfo_ppid; 728 729 /* Set the flags for an unordered send. */ 730 if (sinfo->sinfo_flags & SCTP_UNORDERED) { 731 flags |= SCTP_DATA_UNORDERED; 732 dp.ssn = 0; 733 } else 734 dp.ssn = htons(ssn); 735 736 chunk_len = sizeof(dp) + data_len; 737 retval = sctp_make_data(asoc, flags, chunk_len); 738 if (!retval) 739 goto nodata; 740 741 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp); 742 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo)); 743 744 nodata: 745 return retval; 746 } 747 748 /* Create a selective ackowledgement (SACK) for the given 749 * association. This reports on which TSN's we've seen to date, 750 * including duplicates and gaps. 751 */ 752 struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc) 753 { 754 struct sctp_chunk *retval; 755 struct sctp_sackhdr sack; 756 int len; 757 __u32 ctsn; 758 __u16 num_gabs, num_dup_tsns; 759 struct sctp_association *aptr = (struct sctp_association *)asoc; 760 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; 761 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; 762 struct sctp_transport *trans; 763 764 memset(gabs, 0, sizeof(gabs)); 765 ctsn = sctp_tsnmap_get_ctsn(map); 766 767 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn); 768 769 /* How much room is needed in the chunk? */ 770 num_gabs = sctp_tsnmap_num_gabs(map, gabs); 771 num_dup_tsns = sctp_tsnmap_num_dups(map); 772 773 /* Initialize the SACK header. */ 774 sack.cum_tsn_ack = htonl(ctsn); 775 sack.a_rwnd = htonl(asoc->a_rwnd); 776 sack.num_gap_ack_blocks = htons(num_gabs); 777 sack.num_dup_tsns = htons(num_dup_tsns); 778 779 len = sizeof(sack) 780 + sizeof(struct sctp_gap_ack_block) * num_gabs 781 + sizeof(__u32) * num_dup_tsns; 782 783 /* Create the chunk. */ 784 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len); 785 if (!retval) 786 goto nodata; 787 788 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 789 * 790 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 791 * HEARTBEAT ACK, etc.) to the same destination transport 792 * address from which it received the DATA or control chunk to 793 * which it is replying. This rule should also be followed if 794 * the endpoint is bundling DATA chunks together with the 795 * reply chunk. 796 * 797 * However, when acknowledging multiple DATA chunks received 798 * in packets from different source addresses in a single 799 * SACK, the SACK chunk may be transmitted to one of the 800 * destination transport addresses from which the DATA or 801 * control chunks being acknowledged were received. 802 * 803 * [BUG: We do not implement the following paragraph. 804 * Perhaps we should remember the last transport we used for a 805 * SACK and avoid that (if possible) if we have seen any 806 * duplicates. --piggy] 807 * 808 * When a receiver of a duplicate DATA chunk sends a SACK to a 809 * multi- homed endpoint it MAY be beneficial to vary the 810 * destination address and not use the source address of the 811 * DATA chunk. The reason being that receiving a duplicate 812 * from a multi-homed endpoint might indicate that the return 813 * path (as specified in the source address of the DATA chunk) 814 * for the SACK is broken. 815 * 816 * [Send to the address from which we last received a DATA chunk.] 817 */ 818 retval->transport = asoc->peer.last_data_from; 819 820 retval->subh.sack_hdr = 821 sctp_addto_chunk(retval, sizeof(sack), &sack); 822 823 /* Add the gap ack block information. */ 824 if (num_gabs) 825 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, 826 gabs); 827 828 /* Add the duplicate TSN information. */ 829 if (num_dup_tsns) { 830 aptr->stats.idupchunks += num_dup_tsns; 831 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, 832 sctp_tsnmap_get_dups(map)); 833 } 834 /* Once we have a sack generated, check to see what our sack 835 * generation is, if its 0, reset the transports to 0, and reset 836 * the association generation to 1 837 * 838 * The idea is that zero is never used as a valid generation for the 839 * association so no transport will match after a wrap event like this, 840 * Until the next sack 841 */ 842 if (++aptr->peer.sack_generation == 0) { 843 list_for_each_entry(trans, &asoc->peer.transport_addr_list, 844 transports) 845 trans->sack_generation = 0; 846 aptr->peer.sack_generation = 1; 847 } 848 nodata: 849 return retval; 850 } 851 852 /* Make a SHUTDOWN chunk. */ 853 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 854 const struct sctp_chunk *chunk) 855 { 856 struct sctp_chunk *retval; 857 sctp_shutdownhdr_t shut; 858 __u32 ctsn; 859 860 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 861 shut.cum_tsn_ack = htonl(ctsn); 862 863 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0, 864 sizeof(sctp_shutdownhdr_t)); 865 if (!retval) 866 goto nodata; 867 868 retval->subh.shutdown_hdr = 869 sctp_addto_chunk(retval, sizeof(shut), &shut); 870 871 if (chunk) 872 retval->transport = chunk->transport; 873 nodata: 874 return retval; 875 } 876 877 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 878 const struct sctp_chunk *chunk) 879 { 880 struct sctp_chunk *retval; 881 882 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0); 883 884 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 885 * 886 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 887 * HEARTBEAT ACK, * etc.) to the same destination transport 888 * address from which it * received the DATA or control chunk 889 * to which it is replying. 890 * 891 * [ACK back to where the SHUTDOWN came from.] 892 */ 893 if (retval && chunk) 894 retval->transport = chunk->transport; 895 896 return retval; 897 } 898 899 struct sctp_chunk *sctp_make_shutdown_complete( 900 const struct sctp_association *asoc, 901 const struct sctp_chunk *chunk) 902 { 903 struct sctp_chunk *retval; 904 __u8 flags = 0; 905 906 /* Set the T-bit if we have no association (vtag will be 907 * reflected) 908 */ 909 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; 910 911 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0); 912 913 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 914 * 915 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 916 * HEARTBEAT ACK, * etc.) to the same destination transport 917 * address from which it * received the DATA or control chunk 918 * to which it is replying. 919 * 920 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK 921 * came from.] 922 */ 923 if (retval && chunk) 924 retval->transport = chunk->transport; 925 926 return retval; 927 } 928 929 /* Create an ABORT. Note that we set the T bit if we have no 930 * association, except when responding to an INIT (sctpimpguide 2.41). 931 */ 932 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 933 const struct sctp_chunk *chunk, 934 const size_t hint) 935 { 936 struct sctp_chunk *retval; 937 __u8 flags = 0; 938 939 /* Set the T-bit if we have no association and 'chunk' is not 940 * an INIT (vtag will be reflected). 941 */ 942 if (!asoc) { 943 if (chunk && chunk->chunk_hdr && 944 chunk->chunk_hdr->type == SCTP_CID_INIT) 945 flags = 0; 946 else 947 flags = SCTP_CHUNK_FLAG_T; 948 } 949 950 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint); 951 952 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 953 * 954 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 955 * HEARTBEAT ACK, * etc.) to the same destination transport 956 * address from which it * received the DATA or control chunk 957 * to which it is replying. 958 * 959 * [ABORT back to where the offender came from.] 960 */ 961 if (retval && chunk) 962 retval->transport = chunk->transport; 963 964 return retval; 965 } 966 967 /* Helper to create ABORT with a NO_USER_DATA error. */ 968 struct sctp_chunk *sctp_make_abort_no_data( 969 const struct sctp_association *asoc, 970 const struct sctp_chunk *chunk, __u32 tsn) 971 { 972 struct sctp_chunk *retval; 973 __be32 payload; 974 975 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) 976 + sizeof(tsn)); 977 978 if (!retval) 979 goto no_mem; 980 981 /* Put the tsn back into network byte order. */ 982 payload = htonl(tsn); 983 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload)); 984 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload); 985 986 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 987 * 988 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 989 * HEARTBEAT ACK, * etc.) to the same destination transport 990 * address from which it * received the DATA or control chunk 991 * to which it is replying. 992 * 993 * [ABORT back to where the offender came from.] 994 */ 995 if (chunk) 996 retval->transport = chunk->transport; 997 998 no_mem: 999 return retval; 1000 } 1001 1002 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ 1003 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 1004 struct msghdr *msg, 1005 size_t paylen) 1006 { 1007 struct sctp_chunk *retval; 1008 void *payload = NULL; 1009 int err; 1010 1011 retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen); 1012 if (!retval) 1013 goto err_chunk; 1014 1015 if (paylen) { 1016 /* Put the msg_iov together into payload. */ 1017 payload = kmalloc(paylen, GFP_KERNEL); 1018 if (!payload) 1019 goto err_payload; 1020 1021 err = memcpy_from_msg(payload, msg, paylen); 1022 if (err < 0) 1023 goto err_copy; 1024 } 1025 1026 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); 1027 sctp_addto_chunk(retval, paylen, payload); 1028 1029 if (paylen) 1030 kfree(payload); 1031 1032 return retval; 1033 1034 err_copy: 1035 kfree(payload); 1036 err_payload: 1037 sctp_chunk_free(retval); 1038 retval = NULL; 1039 err_chunk: 1040 return retval; 1041 } 1042 1043 /* Append bytes to the end of a parameter. Will panic if chunk is not big 1044 * enough. 1045 */ 1046 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 1047 const void *data) 1048 { 1049 void *target; 1050 int chunklen = ntohs(chunk->chunk_hdr->length); 1051 1052 target = skb_put(chunk->skb, len); 1053 1054 if (data) 1055 memcpy(target, data, len); 1056 else 1057 memset(target, 0, len); 1058 1059 /* Adjust the chunk length field. */ 1060 chunk->chunk_hdr->length = htons(chunklen + len); 1061 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1062 1063 return target; 1064 } 1065 1066 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ 1067 struct sctp_chunk *sctp_make_abort_violation( 1068 const struct sctp_association *asoc, 1069 const struct sctp_chunk *chunk, 1070 const __u8 *payload, 1071 const size_t paylen) 1072 { 1073 struct sctp_chunk *retval; 1074 struct sctp_paramhdr phdr; 1075 1076 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen 1077 + sizeof(sctp_paramhdr_t)); 1078 if (!retval) 1079 goto end; 1080 1081 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen 1082 + sizeof(sctp_paramhdr_t)); 1083 1084 phdr.type = htons(chunk->chunk_hdr->type); 1085 phdr.length = chunk->chunk_hdr->length; 1086 sctp_addto_chunk(retval, paylen, payload); 1087 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr); 1088 1089 end: 1090 return retval; 1091 } 1092 1093 struct sctp_chunk *sctp_make_violation_paramlen( 1094 const struct sctp_association *asoc, 1095 const struct sctp_chunk *chunk, 1096 struct sctp_paramhdr *param) 1097 { 1098 struct sctp_chunk *retval; 1099 static const char error[] = "The following parameter had invalid length:"; 1100 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t) + 1101 sizeof(sctp_paramhdr_t); 1102 1103 retval = sctp_make_abort(asoc, chunk, payload_len); 1104 if (!retval) 1105 goto nodata; 1106 1107 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, 1108 sizeof(error) + sizeof(sctp_paramhdr_t)); 1109 sctp_addto_chunk(retval, sizeof(error), error); 1110 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), param); 1111 1112 nodata: 1113 return retval; 1114 } 1115 1116 struct sctp_chunk *sctp_make_violation_max_retrans( 1117 const struct sctp_association *asoc, 1118 const struct sctp_chunk *chunk) 1119 { 1120 struct sctp_chunk *retval; 1121 static const char error[] = "Association exceeded its max_retans count"; 1122 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t); 1123 1124 retval = sctp_make_abort(asoc, chunk, payload_len); 1125 if (!retval) 1126 goto nodata; 1127 1128 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error)); 1129 sctp_addto_chunk(retval, sizeof(error), error); 1130 1131 nodata: 1132 return retval; 1133 } 1134 1135 /* Make a HEARTBEAT chunk. */ 1136 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1137 const struct sctp_transport *transport) 1138 { 1139 struct sctp_chunk *retval; 1140 sctp_sender_hb_info_t hbinfo; 1141 1142 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, sizeof(hbinfo)); 1143 1144 if (!retval) 1145 goto nodata; 1146 1147 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; 1148 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t)); 1149 hbinfo.daddr = transport->ipaddr; 1150 hbinfo.sent_at = jiffies; 1151 hbinfo.hb_nonce = transport->hb_nonce; 1152 1153 /* Cast away the 'const', as this is just telling the chunk 1154 * what transport it belongs to. 1155 */ 1156 retval->transport = (struct sctp_transport *) transport; 1157 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo), 1158 &hbinfo); 1159 1160 nodata: 1161 return retval; 1162 } 1163 1164 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1165 const struct sctp_chunk *chunk, 1166 const void *payload, const size_t paylen) 1167 { 1168 struct sctp_chunk *retval; 1169 1170 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen); 1171 if (!retval) 1172 goto nodata; 1173 1174 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1175 1176 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1177 * 1178 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1179 * HEARTBEAT ACK, * etc.) to the same destination transport 1180 * address from which it * received the DATA or control chunk 1181 * to which it is replying. 1182 * 1183 * [HBACK back to where the HEARTBEAT came from.] 1184 */ 1185 if (chunk) 1186 retval->transport = chunk->transport; 1187 1188 nodata: 1189 return retval; 1190 } 1191 1192 /* Create an Operation Error chunk with the specified space reserved. 1193 * This routine can be used for containing multiple causes in the chunk. 1194 */ 1195 static struct sctp_chunk *sctp_make_op_error_space( 1196 const struct sctp_association *asoc, 1197 const struct sctp_chunk *chunk, 1198 size_t size) 1199 { 1200 struct sctp_chunk *retval; 1201 1202 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0, 1203 sizeof(sctp_errhdr_t) + size); 1204 if (!retval) 1205 goto nodata; 1206 1207 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1208 * 1209 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1210 * HEARTBEAT ACK, etc.) to the same destination transport 1211 * address from which it received the DATA or control chunk 1212 * to which it is replying. 1213 * 1214 */ 1215 if (chunk) 1216 retval->transport = chunk->transport; 1217 1218 nodata: 1219 return retval; 1220 } 1221 1222 /* Create an Operation Error chunk of a fixed size, 1223 * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) 1224 * This is a helper function to allocate an error chunk for 1225 * for those invalid parameter codes in which we may not want 1226 * to report all the errors, if the incoming chunk is large 1227 */ 1228 static inline struct sctp_chunk *sctp_make_op_error_fixed( 1229 const struct sctp_association *asoc, 1230 const struct sctp_chunk *chunk) 1231 { 1232 size_t size = asoc ? asoc->pathmtu : 0; 1233 1234 if (!size) 1235 size = SCTP_DEFAULT_MAXSEGMENT; 1236 1237 return sctp_make_op_error_space(asoc, chunk, size); 1238 } 1239 1240 /* Create an Operation Error chunk. */ 1241 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1242 const struct sctp_chunk *chunk, 1243 __be16 cause_code, const void *payload, 1244 size_t paylen, size_t reserve_tail) 1245 { 1246 struct sctp_chunk *retval; 1247 1248 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); 1249 if (!retval) 1250 goto nodata; 1251 1252 sctp_init_cause(retval, cause_code, paylen + reserve_tail); 1253 sctp_addto_chunk(retval, paylen, payload); 1254 if (reserve_tail) 1255 sctp_addto_param(retval, reserve_tail, NULL); 1256 1257 nodata: 1258 return retval; 1259 } 1260 1261 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc) 1262 { 1263 struct sctp_chunk *retval; 1264 struct sctp_hmac *hmac_desc; 1265 struct sctp_authhdr auth_hdr; 1266 __u8 *hmac; 1267 1268 /* Get the first hmac that the peer told us to use */ 1269 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1270 if (unlikely(!hmac_desc)) 1271 return NULL; 1272 1273 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0, 1274 hmac_desc->hmac_len + sizeof(sctp_authhdr_t)); 1275 if (!retval) 1276 return NULL; 1277 1278 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1279 auth_hdr.shkey_id = htons(asoc->active_key_id); 1280 1281 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t), 1282 &auth_hdr); 1283 1284 hmac = skb_put(retval->skb, hmac_desc->hmac_len); 1285 memset(hmac, 0, hmac_desc->hmac_len); 1286 1287 /* Adjust the chunk header to include the empty MAC */ 1288 retval->chunk_hdr->length = 1289 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1290 retval->chunk_end = skb_tail_pointer(retval->skb); 1291 1292 return retval; 1293 } 1294 1295 1296 /******************************************************************** 1297 * 2nd Level Abstractions 1298 ********************************************************************/ 1299 1300 /* Turn an skb into a chunk. 1301 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1302 * 1303 * sctpimpguide-05.txt Section 2.8.2 1304 * M1) Each time a new DATA chunk is transmitted 1305 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1306 * 'TSN.Missing.Report' count will be used to determine missing chunks 1307 * and when to fast retransmit. 1308 * 1309 */ 1310 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1311 const struct sctp_association *asoc, 1312 struct sock *sk) 1313 { 1314 struct sctp_chunk *retval; 1315 1316 retval = kmem_cache_zalloc(sctp_chunk_cachep, GFP_ATOMIC); 1317 1318 if (!retval) 1319 goto nodata; 1320 if (!sk) 1321 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb); 1322 1323 INIT_LIST_HEAD(&retval->list); 1324 retval->skb = skb; 1325 retval->asoc = (struct sctp_association *)asoc; 1326 retval->singleton = 1; 1327 1328 retval->fast_retransmit = SCTP_CAN_FRTX; 1329 1330 /* Polish the bead hole. */ 1331 INIT_LIST_HEAD(&retval->transmitted_list); 1332 INIT_LIST_HEAD(&retval->frag_list); 1333 SCTP_DBG_OBJCNT_INC(chunk); 1334 atomic_set(&retval->refcnt, 1); 1335 1336 nodata: 1337 return retval; 1338 } 1339 1340 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1341 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1342 union sctp_addr *dest) 1343 { 1344 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1345 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1346 } 1347 1348 /* Extract the source address from a chunk. */ 1349 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1350 { 1351 /* If we have a known transport, use that. */ 1352 if (chunk->transport) { 1353 return &chunk->transport->ipaddr; 1354 } else { 1355 /* Otherwise, extract it from the IP header. */ 1356 return &chunk->source; 1357 } 1358 } 1359 1360 /* Create a new chunk, setting the type and flags headers from the 1361 * arguments, reserving enough space for a 'paylen' byte payload. 1362 */ 1363 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 1364 __u8 type, __u8 flags, int paylen) 1365 { 1366 struct sctp_chunk *retval; 1367 sctp_chunkhdr_t *chunk_hdr; 1368 struct sk_buff *skb; 1369 struct sock *sk; 1370 1371 /* No need to allocate LL here, as this is only a chunk. */ 1372 skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen), 1373 GFP_ATOMIC); 1374 if (!skb) 1375 goto nodata; 1376 1377 /* Make room for the chunk header. */ 1378 chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t)); 1379 chunk_hdr->type = type; 1380 chunk_hdr->flags = flags; 1381 chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t)); 1382 1383 sk = asoc ? asoc->base.sk : NULL; 1384 retval = sctp_chunkify(skb, asoc, sk); 1385 if (!retval) { 1386 kfree_skb(skb); 1387 goto nodata; 1388 } 1389 1390 retval->chunk_hdr = chunk_hdr; 1391 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr); 1392 1393 /* Determine if the chunk needs to be authenticated */ 1394 if (sctp_auth_send_cid(type, asoc)) 1395 retval->auth = 1; 1396 1397 return retval; 1398 nodata: 1399 return NULL; 1400 } 1401 1402 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 1403 __u8 flags, int paylen) 1404 { 1405 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen); 1406 } 1407 1408 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 1409 __u8 type, __u8 flags, int paylen) 1410 { 1411 struct sctp_chunk *chunk = _sctp_make_chunk(asoc, type, flags, paylen); 1412 1413 if (chunk) 1414 sctp_control_set_owner_w(chunk); 1415 1416 return chunk; 1417 } 1418 1419 /* Release the memory occupied by a chunk. */ 1420 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1421 { 1422 BUG_ON(!list_empty(&chunk->list)); 1423 list_del_init(&chunk->transmitted_list); 1424 1425 consume_skb(chunk->skb); 1426 consume_skb(chunk->auth_chunk); 1427 1428 SCTP_DBG_OBJCNT_DEC(chunk); 1429 kmem_cache_free(sctp_chunk_cachep, chunk); 1430 } 1431 1432 /* Possibly, free the chunk. */ 1433 void sctp_chunk_free(struct sctp_chunk *chunk) 1434 { 1435 /* Release our reference on the message tracker. */ 1436 if (chunk->msg) 1437 sctp_datamsg_put(chunk->msg); 1438 1439 sctp_chunk_put(chunk); 1440 } 1441 1442 /* Grab a reference to the chunk. */ 1443 void sctp_chunk_hold(struct sctp_chunk *ch) 1444 { 1445 atomic_inc(&ch->refcnt); 1446 } 1447 1448 /* Release a reference to the chunk. */ 1449 void sctp_chunk_put(struct sctp_chunk *ch) 1450 { 1451 if (atomic_dec_and_test(&ch->refcnt)) 1452 sctp_chunk_destroy(ch); 1453 } 1454 1455 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1456 * enough. 1457 */ 1458 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1459 { 1460 void *target; 1461 void *padding; 1462 int chunklen = ntohs(chunk->chunk_hdr->length); 1463 int padlen = WORD_ROUND(chunklen) - chunklen; 1464 1465 padding = skb_put(chunk->skb, padlen); 1466 target = skb_put(chunk->skb, len); 1467 1468 memset(padding, 0, padlen); 1469 memcpy(target, data, len); 1470 1471 /* Adjust the chunk length field. */ 1472 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1473 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1474 1475 return target; 1476 } 1477 1478 /* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient 1479 * space in the chunk 1480 */ 1481 static void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk, 1482 int len, const void *data) 1483 { 1484 if (skb_tailroom(chunk->skb) >= len) 1485 return sctp_addto_chunk(chunk, len, data); 1486 else 1487 return NULL; 1488 } 1489 1490 /* Append bytes from user space to the end of a chunk. Will panic if 1491 * chunk is not big enough. 1492 * Returns a kernel err value. 1493 */ 1494 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len, 1495 struct iov_iter *from) 1496 { 1497 void *target; 1498 ssize_t copied; 1499 1500 /* Make room in chunk for data. */ 1501 target = skb_put(chunk->skb, len); 1502 1503 /* Copy data (whole iovec) into chunk */ 1504 copied = copy_from_iter(target, len, from); 1505 if (copied != len) 1506 return -EFAULT; 1507 1508 /* Adjust the chunk length field. */ 1509 chunk->chunk_hdr->length = 1510 htons(ntohs(chunk->chunk_hdr->length) + len); 1511 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1512 1513 return 0; 1514 } 1515 1516 /* Helper function to assign a TSN if needed. This assumes that both 1517 * the data_hdr and association have already been assigned. 1518 */ 1519 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1520 { 1521 struct sctp_datamsg *msg; 1522 struct sctp_chunk *lchunk; 1523 struct sctp_stream *stream; 1524 __u16 ssn; 1525 __u16 sid; 1526 1527 if (chunk->has_ssn) 1528 return; 1529 1530 /* All fragments will be on the same stream */ 1531 sid = ntohs(chunk->subh.data_hdr->stream); 1532 stream = &chunk->asoc->ssnmap->out; 1533 1534 /* Now assign the sequence number to the entire message. 1535 * All fragments must have the same stream sequence number. 1536 */ 1537 msg = chunk->msg; 1538 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1539 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1540 ssn = 0; 1541 } else { 1542 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1543 ssn = sctp_ssn_next(stream, sid); 1544 else 1545 ssn = sctp_ssn_peek(stream, sid); 1546 } 1547 1548 lchunk->subh.data_hdr->ssn = htons(ssn); 1549 lchunk->has_ssn = 1; 1550 } 1551 } 1552 1553 /* Helper function to assign a TSN if needed. This assumes that both 1554 * the data_hdr and association have already been assigned. 1555 */ 1556 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1557 { 1558 if (!chunk->has_tsn) { 1559 /* This is the last possible instant to 1560 * assign a TSN. 1561 */ 1562 chunk->subh.data_hdr->tsn = 1563 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1564 chunk->has_tsn = 1; 1565 } 1566 } 1567 1568 /* Create a CLOSED association to use with an incoming packet. */ 1569 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1570 struct sctp_chunk *chunk, 1571 gfp_t gfp) 1572 { 1573 struct sctp_association *asoc; 1574 struct sk_buff *skb; 1575 sctp_scope_t scope; 1576 struct sctp_af *af; 1577 1578 /* Create the bare association. */ 1579 scope = sctp_scope(sctp_source(chunk)); 1580 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1581 if (!asoc) 1582 goto nodata; 1583 asoc->temp = 1; 1584 skb = chunk->skb; 1585 /* Create an entry for the source address of the packet. */ 1586 af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version)); 1587 if (unlikely(!af)) 1588 goto fail; 1589 af->from_skb(&asoc->c.peer_addr, skb, 1); 1590 nodata: 1591 return asoc; 1592 1593 fail: 1594 sctp_association_free(asoc); 1595 return NULL; 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 sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, 1602 const struct sctp_association *asoc, 1603 const struct sctp_chunk *init_chunk, 1604 int *cookie_len, 1605 const __u8 *raw_addrs, int addrs_len) 1606 { 1607 sctp_cookie_param_t *retval; 1608 struct sctp_signed_cookie *cookie; 1609 struct scatterlist sg; 1610 int headersize, bodysize; 1611 1612 /* Header size is static data prior to the actual cookie, including 1613 * any padding. 1614 */ 1615 headersize = sizeof(sctp_paramhdr_t) + 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()); 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 struct hash_desc desc; 1667 1668 /* Sign the message. */ 1669 sg_init_one(&sg, &cookie->c, bodysize); 1670 desc.tfm = sctp_sk(ep->base.sk)->hmac; 1671 desc.flags = 0; 1672 1673 if (crypto_hash_setkey(desc.tfm, ep->secret_key, 1674 sizeof(ep->secret_key)) || 1675 crypto_hash_digest(&desc, &sg, bodysize, cookie->signature)) 1676 goto free_cookie; 1677 } 1678 1679 return retval; 1680 1681 free_cookie: 1682 kfree(retval); 1683 nodata: 1684 *cookie_len = 0; 1685 return NULL; 1686 } 1687 1688 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1689 struct sctp_association *sctp_unpack_cookie( 1690 const struct sctp_endpoint *ep, 1691 const struct sctp_association *asoc, 1692 struct sctp_chunk *chunk, gfp_t gfp, 1693 int *error, struct sctp_chunk **errp) 1694 { 1695 struct sctp_association *retval = NULL; 1696 struct sctp_signed_cookie *cookie; 1697 struct sctp_cookie *bear_cookie; 1698 int headersize, bodysize, fixed_size; 1699 __u8 *digest = ep->digest; 1700 struct scatterlist sg; 1701 unsigned int len; 1702 sctp_scope_t scope; 1703 struct sk_buff *skb = chunk->skb; 1704 ktime_t kt; 1705 struct hash_desc desc; 1706 1707 /* Header size is static data prior to the actual cookie, including 1708 * any padding. 1709 */ 1710 headersize = sizeof(sctp_chunkhdr_t) + 1711 (sizeof(struct sctp_signed_cookie) - 1712 sizeof(struct sctp_cookie)); 1713 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1714 fixed_size = headersize + sizeof(struct sctp_cookie); 1715 1716 /* Verify that the chunk looks like it even has a cookie. 1717 * There must be enough room for our cookie and our peer's 1718 * INIT chunk. 1719 */ 1720 len = ntohs(chunk->chunk_hdr->length); 1721 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1722 goto malformed; 1723 1724 /* Verify that the cookie has been padded out. */ 1725 if (bodysize % SCTP_COOKIE_MULTIPLE) 1726 goto malformed; 1727 1728 /* Process the cookie. */ 1729 cookie = chunk->subh.cookie_hdr; 1730 bear_cookie = &cookie->c; 1731 1732 if (!sctp_sk(ep->base.sk)->hmac) 1733 goto no_hmac; 1734 1735 /* Check the signature. */ 1736 sg_init_one(&sg, bear_cookie, bodysize); 1737 desc.tfm = sctp_sk(ep->base.sk)->hmac; 1738 desc.flags = 0; 1739 1740 memset(digest, 0x00, SCTP_SIGNATURE_SIZE); 1741 if (crypto_hash_setkey(desc.tfm, ep->secret_key, 1742 sizeof(ep->secret_key)) || 1743 crypto_hash_digest(&desc, &sg, bodysize, digest)) { 1744 *error = -SCTP_IERROR_NOMEM; 1745 goto fail; 1746 } 1747 1748 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1749 *error = -SCTP_IERROR_BAD_SIG; 1750 goto fail; 1751 } 1752 1753 no_hmac: 1754 /* IG Section 2.35.2: 1755 * 3) Compare the port numbers and the verification tag contained 1756 * within the COOKIE ECHO chunk to the actual port numbers and the 1757 * verification tag within the SCTP common header of the received 1758 * packet. If these values do not match the packet MUST be silently 1759 * discarded, 1760 */ 1761 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1762 *error = -SCTP_IERROR_BAD_TAG; 1763 goto fail; 1764 } 1765 1766 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1767 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1768 *error = -SCTP_IERROR_BAD_PORTS; 1769 goto fail; 1770 } 1771 1772 /* Check to see if the cookie is stale. If there is already 1773 * an association, there is no need to check cookie's expiration 1774 * for init collision case of lost COOKIE ACK. 1775 * If skb has been timestamped, then use the stamp, otherwise 1776 * use current time. This introduces a small possibility that 1777 * that a cookie may be considered expired, but his would only slow 1778 * down the new association establishment instead of every packet. 1779 */ 1780 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1781 kt = skb_get_ktime(skb); 1782 else 1783 kt = ktime_get(); 1784 1785 if (!asoc && ktime_before(bear_cookie->expiration, kt)) { 1786 /* 1787 * Section 3.3.10.3 Stale Cookie Error (3) 1788 * 1789 * Cause of error 1790 * --------------- 1791 * Stale Cookie Error: Indicates the receipt of a valid State 1792 * Cookie that has expired. 1793 */ 1794 len = ntohs(chunk->chunk_hdr->length); 1795 *errp = sctp_make_op_error_space(asoc, chunk, len); 1796 if (*errp) { 1797 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); 1798 __be32 n = htonl(usecs); 1799 1800 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE, 1801 sizeof(n)); 1802 sctp_addto_chunk(*errp, sizeof(n), &n); 1803 *error = -SCTP_IERROR_STALE_COOKIE; 1804 } else 1805 *error = -SCTP_IERROR_NOMEM; 1806 1807 goto fail; 1808 } 1809 1810 /* Make a new base association. */ 1811 scope = sctp_scope(sctp_source(chunk)); 1812 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1813 if (!retval) { 1814 *error = -SCTP_IERROR_NOMEM; 1815 goto fail; 1816 } 1817 1818 /* Set up our peer's port number. */ 1819 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1820 1821 /* Populate the association from the cookie. */ 1822 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1823 1824 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1825 GFP_ATOMIC) < 0) { 1826 *error = -SCTP_IERROR_NOMEM; 1827 goto fail; 1828 } 1829 1830 /* Also, add the destination address. */ 1831 if (list_empty(&retval->base.bind_addr.address_list)) { 1832 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1833 SCTP_ADDR_SRC, GFP_ATOMIC); 1834 } 1835 1836 retval->next_tsn = retval->c.initial_tsn; 1837 retval->ctsn_ack_point = retval->next_tsn - 1; 1838 retval->addip_serial = retval->c.initial_tsn; 1839 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1840 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1841 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1842 1843 /* The INIT stuff will be done by the side effects. */ 1844 return retval; 1845 1846 fail: 1847 if (retval) 1848 sctp_association_free(retval); 1849 1850 return NULL; 1851 1852 malformed: 1853 /* Yikes! The packet is either corrupt or deliberately 1854 * malformed. 1855 */ 1856 *error = -SCTP_IERROR_MALFORMED; 1857 goto fail; 1858 } 1859 1860 /******************************************************************** 1861 * 3rd Level Abstractions 1862 ********************************************************************/ 1863 1864 struct __sctp_missing { 1865 __be32 num_missing; 1866 __be16 type; 1867 } __packed; 1868 1869 /* 1870 * Report a missing mandatory parameter. 1871 */ 1872 static int sctp_process_missing_param(const struct sctp_association *asoc, 1873 sctp_param_t paramtype, 1874 struct sctp_chunk *chunk, 1875 struct sctp_chunk **errp) 1876 { 1877 struct __sctp_missing report; 1878 __u16 len; 1879 1880 len = WORD_ROUND(sizeof(report)); 1881 1882 /* Make an ERROR chunk, preparing enough room for 1883 * returning multiple unknown parameters. 1884 */ 1885 if (!*errp) 1886 *errp = sctp_make_op_error_space(asoc, chunk, len); 1887 1888 if (*errp) { 1889 report.num_missing = htonl(1); 1890 report.type = paramtype; 1891 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1892 sizeof(report)); 1893 sctp_addto_chunk(*errp, sizeof(report), &report); 1894 } 1895 1896 /* Stop processing this chunk. */ 1897 return 0; 1898 } 1899 1900 /* Report an Invalid Mandatory Parameter. */ 1901 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1902 struct sctp_chunk *chunk, 1903 struct sctp_chunk **errp) 1904 { 1905 /* Invalid Mandatory Parameter Error has no payload. */ 1906 1907 if (!*errp) 1908 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1909 1910 if (*errp) 1911 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1912 1913 /* Stop processing this chunk. */ 1914 return 0; 1915 } 1916 1917 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1918 struct sctp_paramhdr *param, 1919 const struct sctp_chunk *chunk, 1920 struct sctp_chunk **errp) 1921 { 1922 /* This is a fatal error. Any accumulated non-fatal errors are 1923 * not reported. 1924 */ 1925 if (*errp) 1926 sctp_chunk_free(*errp); 1927 1928 /* Create an error chunk and fill it in with our payload. */ 1929 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1930 1931 return 0; 1932 } 1933 1934 1935 /* Do not attempt to handle the HOST_NAME parm. However, do 1936 * send back an indicator to the peer. 1937 */ 1938 static int sctp_process_hn_param(const struct sctp_association *asoc, 1939 union sctp_params param, 1940 struct sctp_chunk *chunk, 1941 struct sctp_chunk **errp) 1942 { 1943 __u16 len = ntohs(param.p->length); 1944 1945 /* Processing of the HOST_NAME parameter will generate an 1946 * ABORT. If we've accumulated any non-fatal errors, they 1947 * would be unrecognized parameters and we should not include 1948 * them in the ABORT. 1949 */ 1950 if (*errp) 1951 sctp_chunk_free(*errp); 1952 1953 *errp = sctp_make_op_error_space(asoc, chunk, len); 1954 1955 if (*errp) { 1956 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len); 1957 sctp_addto_chunk(*errp, len, param.v); 1958 } 1959 1960 /* Stop processing this chunk. */ 1961 return 0; 1962 } 1963 1964 static int sctp_verify_ext_param(struct net *net, union sctp_params param) 1965 { 1966 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 1967 int have_auth = 0; 1968 int have_asconf = 0; 1969 int i; 1970 1971 for (i = 0; i < num_ext; i++) { 1972 switch (param.ext->chunks[i]) { 1973 case SCTP_CID_AUTH: 1974 have_auth = 1; 1975 break; 1976 case SCTP_CID_ASCONF: 1977 case SCTP_CID_ASCONF_ACK: 1978 have_asconf = 1; 1979 break; 1980 } 1981 } 1982 1983 /* ADD-IP Security: The draft requires us to ABORT or ignore the 1984 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 1985 * only if ADD-IP is turned on and we are not backward-compatible 1986 * mode. 1987 */ 1988 if (net->sctp.addip_noauth) 1989 return 1; 1990 1991 if (net->sctp.addip_enable && !have_auth && have_asconf) 1992 return 0; 1993 1994 return 1; 1995 } 1996 1997 static void sctp_process_ext_param(struct sctp_association *asoc, 1998 union sctp_params param) 1999 { 2000 struct net *net = sock_net(asoc->base.sk); 2001 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2002 int i; 2003 2004 for (i = 0; i < num_ext; i++) { 2005 switch (param.ext->chunks[i]) { 2006 case SCTP_CID_FWD_TSN: 2007 if (net->sctp.prsctp_enable && !asoc->peer.prsctp_capable) 2008 asoc->peer.prsctp_capable = 1; 2009 break; 2010 case SCTP_CID_AUTH: 2011 /* if the peer reports AUTH, assume that he 2012 * supports AUTH. 2013 */ 2014 if (asoc->ep->auth_enable) 2015 asoc->peer.auth_capable = 1; 2016 break; 2017 case SCTP_CID_ASCONF: 2018 case SCTP_CID_ASCONF_ACK: 2019 if (net->sctp.addip_enable) 2020 asoc->peer.asconf_capable = 1; 2021 break; 2022 default: 2023 break; 2024 } 2025 } 2026 } 2027 2028 /* RFC 3.2.1 & the Implementers Guide 2.2. 2029 * 2030 * The Parameter Types are encoded such that the 2031 * highest-order two bits specify the action that must be 2032 * taken if the processing endpoint does not recognize the 2033 * Parameter Type. 2034 * 2035 * 00 - Stop processing this parameter; do not process any further 2036 * parameters within this chunk 2037 * 2038 * 01 - Stop processing this parameter, do not process any further 2039 * parameters within this chunk, and report the unrecognized 2040 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2041 * 2042 * 10 - Skip this parameter and continue processing. 2043 * 2044 * 11 - Skip this parameter and continue processing but 2045 * report the unrecognized parameter in an 2046 * 'Unrecognized Parameter' ERROR chunk. 2047 * 2048 * Return value: 2049 * SCTP_IERROR_NO_ERROR - continue with the chunk 2050 * SCTP_IERROR_ERROR - stop and report an error. 2051 * SCTP_IERROR_NOMEME - out of memory. 2052 */ 2053 static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc, 2054 union sctp_params param, 2055 struct sctp_chunk *chunk, 2056 struct sctp_chunk **errp) 2057 { 2058 int retval = SCTP_IERROR_NO_ERROR; 2059 2060 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2061 case SCTP_PARAM_ACTION_DISCARD: 2062 retval = SCTP_IERROR_ERROR; 2063 break; 2064 case SCTP_PARAM_ACTION_SKIP: 2065 break; 2066 case SCTP_PARAM_ACTION_DISCARD_ERR: 2067 retval = SCTP_IERROR_ERROR; 2068 /* Fall through */ 2069 case SCTP_PARAM_ACTION_SKIP_ERR: 2070 /* Make an ERROR chunk, preparing enough room for 2071 * returning multiple unknown parameters. 2072 */ 2073 if (NULL == *errp) 2074 *errp = sctp_make_op_error_fixed(asoc, chunk); 2075 2076 if (*errp) { 2077 if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2078 WORD_ROUND(ntohs(param.p->length)))) 2079 sctp_addto_chunk_fixed(*errp, 2080 WORD_ROUND(ntohs(param.p->length)), 2081 param.v); 2082 } else { 2083 /* If there is no memory for generating the ERROR 2084 * report as specified, an ABORT will be triggered 2085 * to the peer and the association won't be 2086 * established. 2087 */ 2088 retval = SCTP_IERROR_NOMEM; 2089 } 2090 break; 2091 default: 2092 break; 2093 } 2094 2095 return retval; 2096 } 2097 2098 /* Verify variable length parameters 2099 * Return values: 2100 * SCTP_IERROR_ABORT - trigger an ABORT 2101 * SCTP_IERROR_NOMEM - out of memory (abort) 2102 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2103 * SCTP_IERROR_NO_ERROR - continue with the chunk 2104 */ 2105 static sctp_ierror_t sctp_verify_param(struct net *net, 2106 const struct sctp_endpoint *ep, 2107 const struct sctp_association *asoc, 2108 union sctp_params param, 2109 sctp_cid_t cid, 2110 struct sctp_chunk *chunk, 2111 struct sctp_chunk **err_chunk) 2112 { 2113 struct sctp_hmac_algo_param *hmacs; 2114 int retval = SCTP_IERROR_NO_ERROR; 2115 __u16 n_elt, id = 0; 2116 int i; 2117 2118 /* FIXME - This routine is not looking at each parameter per the 2119 * chunk type, i.e., unrecognized parameters should be further 2120 * identified based on the chunk id. 2121 */ 2122 2123 switch (param.p->type) { 2124 case SCTP_PARAM_IPV4_ADDRESS: 2125 case SCTP_PARAM_IPV6_ADDRESS: 2126 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2127 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2128 case SCTP_PARAM_STATE_COOKIE: 2129 case SCTP_PARAM_HEARTBEAT_INFO: 2130 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2131 case SCTP_PARAM_ECN_CAPABLE: 2132 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2133 break; 2134 2135 case SCTP_PARAM_SUPPORTED_EXT: 2136 if (!sctp_verify_ext_param(net, param)) 2137 return SCTP_IERROR_ABORT; 2138 break; 2139 2140 case SCTP_PARAM_SET_PRIMARY: 2141 if (net->sctp.addip_enable) 2142 break; 2143 goto fallthrough; 2144 2145 case SCTP_PARAM_HOST_NAME_ADDRESS: 2146 /* Tell the peer, we won't support this param. */ 2147 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2148 retval = SCTP_IERROR_ABORT; 2149 break; 2150 2151 case SCTP_PARAM_FWD_TSN_SUPPORT: 2152 if (net->sctp.prsctp_enable) 2153 break; 2154 goto fallthrough; 2155 2156 case SCTP_PARAM_RANDOM: 2157 if (!ep->auth_enable) 2158 goto fallthrough; 2159 2160 /* SCTP-AUTH: Secion 6.1 2161 * If the random number is not 32 byte long the association 2162 * MUST be aborted. The ABORT chunk SHOULD contain the error 2163 * cause 'Protocol Violation'. 2164 */ 2165 if (SCTP_AUTH_RANDOM_LENGTH != 2166 ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) { 2167 sctp_process_inv_paramlength(asoc, param.p, 2168 chunk, err_chunk); 2169 retval = SCTP_IERROR_ABORT; 2170 } 2171 break; 2172 2173 case SCTP_PARAM_CHUNKS: 2174 if (!ep->auth_enable) 2175 goto fallthrough; 2176 2177 /* SCTP-AUTH: Section 3.2 2178 * The CHUNKS parameter MUST be included once in the INIT or 2179 * INIT-ACK chunk if the sender wants to receive authenticated 2180 * chunks. Its maximum length is 260 bytes. 2181 */ 2182 if (260 < ntohs(param.p->length)) { 2183 sctp_process_inv_paramlength(asoc, param.p, 2184 chunk, err_chunk); 2185 retval = SCTP_IERROR_ABORT; 2186 } 2187 break; 2188 2189 case SCTP_PARAM_HMAC_ALGO: 2190 if (!ep->auth_enable) 2191 goto fallthrough; 2192 2193 hmacs = (struct sctp_hmac_algo_param *)param.p; 2194 n_elt = (ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) >> 1; 2195 2196 /* SCTP-AUTH: Section 6.1 2197 * The HMAC algorithm based on SHA-1 MUST be supported and 2198 * included in the HMAC-ALGO parameter. 2199 */ 2200 for (i = 0; i < n_elt; i++) { 2201 id = ntohs(hmacs->hmac_ids[i]); 2202 2203 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2204 break; 2205 } 2206 2207 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2208 sctp_process_inv_paramlength(asoc, param.p, chunk, 2209 err_chunk); 2210 retval = SCTP_IERROR_ABORT; 2211 } 2212 break; 2213 fallthrough: 2214 default: 2215 pr_debug("%s: unrecognized param:%d for chunk:%d\n", 2216 __func__, ntohs(param.p->type), cid); 2217 2218 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2219 break; 2220 } 2221 return retval; 2222 } 2223 2224 /* Verify the INIT packet before we process it. */ 2225 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 2226 const struct sctp_association *asoc, sctp_cid_t cid, 2227 sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk, 2228 struct sctp_chunk **errp) 2229 { 2230 union sctp_params param; 2231 bool has_cookie = false; 2232 int result; 2233 2234 /* Check for missing mandatory parameters. Note: Initial TSN is 2235 * also mandatory, but is not checked here since the valid range 2236 * is 0..2**32-1. RFC4960, section 3.3.3. 2237 */ 2238 if (peer_init->init_hdr.num_outbound_streams == 0 || 2239 peer_init->init_hdr.num_inbound_streams == 0 || 2240 peer_init->init_hdr.init_tag == 0 || 2241 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) 2242 return sctp_process_inv_mandatory(asoc, chunk, errp); 2243 2244 sctp_walk_params(param, peer_init, init_hdr.params) { 2245 if (param.p->type == SCTP_PARAM_STATE_COOKIE) 2246 has_cookie = true; 2247 } 2248 2249 /* There is a possibility that a parameter length was bad and 2250 * in that case we would have stoped walking the parameters. 2251 * The current param.p would point at the bad one. 2252 * Current consensus on the mailing list is to generate a PROTOCOL 2253 * VIOLATION error. We build the ERROR chunk here and let the normal 2254 * error handling code build and send the packet. 2255 */ 2256 if (param.v != (void *)chunk->chunk_end) 2257 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2258 2259 /* The only missing mandatory param possible today is 2260 * the state cookie for an INIT-ACK chunk. 2261 */ 2262 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2263 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2264 chunk, errp); 2265 2266 /* Verify all the variable length parameters */ 2267 sctp_walk_params(param, peer_init, init_hdr.params) { 2268 result = sctp_verify_param(net, ep, asoc, param, cid, 2269 chunk, errp); 2270 switch (result) { 2271 case SCTP_IERROR_ABORT: 2272 case SCTP_IERROR_NOMEM: 2273 return 0; 2274 case SCTP_IERROR_ERROR: 2275 return 1; 2276 case SCTP_IERROR_NO_ERROR: 2277 default: 2278 break; 2279 } 2280 2281 } /* for (loop through all parameters) */ 2282 2283 return 1; 2284 } 2285 2286 /* Unpack the parameters in an INIT packet into an association. 2287 * Returns 0 on failure, else success. 2288 * FIXME: This is an association method. 2289 */ 2290 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2291 const union sctp_addr *peer_addr, 2292 sctp_init_chunk_t *peer_init, gfp_t gfp) 2293 { 2294 struct net *net = sock_net(asoc->base.sk); 2295 union sctp_params param; 2296 struct sctp_transport *transport; 2297 struct list_head *pos, *temp; 2298 struct sctp_af *af; 2299 union sctp_addr addr; 2300 char *cookie; 2301 int src_match = 0; 2302 2303 /* We must include the address that the INIT packet came from. 2304 * This is the only address that matters for an INIT packet. 2305 * When processing a COOKIE ECHO, we retrieve the from address 2306 * of the INIT from the cookie. 2307 */ 2308 2309 /* This implementation defaults to making the first transport 2310 * added as the primary transport. The source address seems to 2311 * be a a better choice than any of the embedded addresses. 2312 */ 2313 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2314 goto nomem; 2315 2316 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2317 src_match = 1; 2318 2319 /* Process the initialization parameters. */ 2320 sctp_walk_params(param, peer_init, init_hdr.params) { 2321 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2322 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2323 af = sctp_get_af_specific(param_type2af(param.p->type)); 2324 af->from_addr_param(&addr, param.addr, 2325 chunk->sctp_hdr->source, 0); 2326 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2327 src_match = 1; 2328 } 2329 2330 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2331 goto clean_up; 2332 } 2333 2334 /* source address of chunk may not match any valid address */ 2335 if (!src_match) 2336 goto clean_up; 2337 2338 /* AUTH: After processing the parameters, make sure that we 2339 * have all the required info to potentially do authentications. 2340 */ 2341 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2342 !asoc->peer.peer_hmacs)) 2343 asoc->peer.auth_capable = 0; 2344 2345 /* In a non-backward compatible mode, if the peer claims 2346 * support for ADD-IP but not AUTH, the ADD-IP spec states 2347 * that we MUST ABORT the association. Section 6. The section 2348 * also give us an option to silently ignore the packet, which 2349 * is what we'll do here. 2350 */ 2351 if (!net->sctp.addip_noauth && 2352 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2353 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2354 SCTP_PARAM_DEL_IP | 2355 SCTP_PARAM_SET_PRIMARY); 2356 asoc->peer.asconf_capable = 0; 2357 goto clean_up; 2358 } 2359 2360 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2361 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2362 transport = list_entry(pos, struct sctp_transport, transports); 2363 if (transport->state == SCTP_UNKNOWN) { 2364 sctp_assoc_rm_peer(asoc, transport); 2365 } 2366 } 2367 2368 /* The fixed INIT headers are always in network byte 2369 * order. 2370 */ 2371 asoc->peer.i.init_tag = 2372 ntohl(peer_init->init_hdr.init_tag); 2373 asoc->peer.i.a_rwnd = 2374 ntohl(peer_init->init_hdr.a_rwnd); 2375 asoc->peer.i.num_outbound_streams = 2376 ntohs(peer_init->init_hdr.num_outbound_streams); 2377 asoc->peer.i.num_inbound_streams = 2378 ntohs(peer_init->init_hdr.num_inbound_streams); 2379 asoc->peer.i.initial_tsn = 2380 ntohl(peer_init->init_hdr.initial_tsn); 2381 2382 /* Apply the upper bounds for output streams based on peer's 2383 * number of inbound streams. 2384 */ 2385 if (asoc->c.sinit_num_ostreams > 2386 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2387 asoc->c.sinit_num_ostreams = 2388 ntohs(peer_init->init_hdr.num_inbound_streams); 2389 } 2390 2391 if (asoc->c.sinit_max_instreams > 2392 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2393 asoc->c.sinit_max_instreams = 2394 ntohs(peer_init->init_hdr.num_outbound_streams); 2395 } 2396 2397 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2398 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2399 2400 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2401 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2402 2403 /* Copy cookie in case we need to resend COOKIE-ECHO. */ 2404 cookie = asoc->peer.cookie; 2405 if (cookie) { 2406 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp); 2407 if (!asoc->peer.cookie) 2408 goto clean_up; 2409 } 2410 2411 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2412 * high (for example, implementations MAY use the size of the receiver 2413 * advertised window). 2414 */ 2415 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2416 transports) { 2417 transport->ssthresh = asoc->peer.i.a_rwnd; 2418 } 2419 2420 /* Set up the TSN tracking pieces. */ 2421 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2422 asoc->peer.i.initial_tsn, gfp)) 2423 goto clean_up; 2424 2425 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2426 * 2427 * The stream sequence number in all the streams shall start 2428 * from 0 when the association is established. Also, when the 2429 * stream sequence number reaches the value 65535 the next 2430 * stream sequence number shall be set to 0. 2431 */ 2432 2433 /* Allocate storage for the negotiated streams if it is not a temporary 2434 * association. 2435 */ 2436 if (!asoc->temp) { 2437 int error; 2438 2439 asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams, 2440 asoc->c.sinit_num_ostreams, gfp); 2441 if (!asoc->ssnmap) 2442 goto clean_up; 2443 2444 error = sctp_assoc_set_id(asoc, gfp); 2445 if (error) 2446 goto clean_up; 2447 } 2448 2449 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2450 * 2451 * When an endpoint has an ASCONF signaled change to be sent to the 2452 * remote endpoint it should do the following: 2453 * ... 2454 * A2) A serial number should be assigned to the Chunk. The serial 2455 * number should be a monotonically increasing number. All serial 2456 * numbers are defined to be initialized at the start of the 2457 * association to the same value as the Initial TSN. 2458 */ 2459 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2460 return 1; 2461 2462 clean_up: 2463 /* Release the transport structures. */ 2464 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2465 transport = list_entry(pos, struct sctp_transport, transports); 2466 if (transport->state != SCTP_ACTIVE) 2467 sctp_assoc_rm_peer(asoc, transport); 2468 } 2469 2470 nomem: 2471 return 0; 2472 } 2473 2474 2475 /* Update asoc with the option described in param. 2476 * 2477 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2478 * 2479 * asoc is the association to update. 2480 * param is the variable length parameter to use for update. 2481 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2482 * If the current packet is an INIT we want to minimize the amount of 2483 * work we do. In particular, we should not build transport 2484 * structures for the addresses. 2485 */ 2486 static int sctp_process_param(struct sctp_association *asoc, 2487 union sctp_params param, 2488 const union sctp_addr *peer_addr, 2489 gfp_t gfp) 2490 { 2491 struct net *net = sock_net(asoc->base.sk); 2492 union sctp_addr addr; 2493 int i; 2494 __u16 sat; 2495 int retval = 1; 2496 sctp_scope_t scope; 2497 u32 stale; 2498 struct sctp_af *af; 2499 union sctp_addr_param *addr_param; 2500 struct sctp_transport *t; 2501 struct sctp_endpoint *ep = asoc->ep; 2502 2503 /* We maintain all INIT parameters in network byte order all the 2504 * time. This allows us to not worry about whether the parameters 2505 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2506 */ 2507 switch (param.p->type) { 2508 case SCTP_PARAM_IPV6_ADDRESS: 2509 if (PF_INET6 != asoc->base.sk->sk_family) 2510 break; 2511 goto do_addr_param; 2512 2513 case SCTP_PARAM_IPV4_ADDRESS: 2514 /* v4 addresses are not allowed on v6-only socket */ 2515 if (ipv6_only_sock(asoc->base.sk)) 2516 break; 2517 do_addr_param: 2518 af = sctp_get_af_specific(param_type2af(param.p->type)); 2519 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); 2520 scope = sctp_scope(peer_addr); 2521 if (sctp_in_scope(net, &addr, scope)) 2522 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2523 return 0; 2524 break; 2525 2526 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2527 if (!net->sctp.cookie_preserve_enable) 2528 break; 2529 2530 stale = ntohl(param.life->lifespan_increment); 2531 2532 /* Suggested Cookie Life span increment's unit is msec, 2533 * (1/1000sec). 2534 */ 2535 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale); 2536 break; 2537 2538 case SCTP_PARAM_HOST_NAME_ADDRESS: 2539 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__); 2540 break; 2541 2542 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2543 /* Turn off the default values first so we'll know which 2544 * ones are really set by the peer. 2545 */ 2546 asoc->peer.ipv4_address = 0; 2547 asoc->peer.ipv6_address = 0; 2548 2549 /* Assume that peer supports the address family 2550 * by which it sends a packet. 2551 */ 2552 if (peer_addr->sa.sa_family == AF_INET6) 2553 asoc->peer.ipv6_address = 1; 2554 else if (peer_addr->sa.sa_family == AF_INET) 2555 asoc->peer.ipv4_address = 1; 2556 2557 /* Cycle through address types; avoid divide by 0. */ 2558 sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2559 if (sat) 2560 sat /= sizeof(__u16); 2561 2562 for (i = 0; i < sat; ++i) { 2563 switch (param.sat->types[i]) { 2564 case SCTP_PARAM_IPV4_ADDRESS: 2565 asoc->peer.ipv4_address = 1; 2566 break; 2567 2568 case SCTP_PARAM_IPV6_ADDRESS: 2569 if (PF_INET6 == asoc->base.sk->sk_family) 2570 asoc->peer.ipv6_address = 1; 2571 break; 2572 2573 case SCTP_PARAM_HOST_NAME_ADDRESS: 2574 asoc->peer.hostname_address = 1; 2575 break; 2576 2577 default: /* Just ignore anything else. */ 2578 break; 2579 } 2580 } 2581 break; 2582 2583 case SCTP_PARAM_STATE_COOKIE: 2584 asoc->peer.cookie_len = 2585 ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2586 asoc->peer.cookie = param.cookie->body; 2587 break; 2588 2589 case SCTP_PARAM_HEARTBEAT_INFO: 2590 /* Would be odd to receive, but it causes no problems. */ 2591 break; 2592 2593 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2594 /* Rejected during verify stage. */ 2595 break; 2596 2597 case SCTP_PARAM_ECN_CAPABLE: 2598 asoc->peer.ecn_capable = 1; 2599 break; 2600 2601 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2602 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2603 break; 2604 2605 case SCTP_PARAM_SET_PRIMARY: 2606 if (!net->sctp.addip_enable) 2607 goto fall_through; 2608 2609 addr_param = param.v + sizeof(sctp_addip_param_t); 2610 2611 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 2612 if (af == NULL) 2613 break; 2614 2615 af->from_addr_param(&addr, addr_param, 2616 htons(asoc->peer.port), 0); 2617 2618 /* if the address is invalid, we can't process it. 2619 * XXX: see spec for what to do. 2620 */ 2621 if (!af->addr_valid(&addr, NULL, NULL)) 2622 break; 2623 2624 t = sctp_assoc_lookup_paddr(asoc, &addr); 2625 if (!t) 2626 break; 2627 2628 sctp_assoc_set_primary(asoc, t); 2629 break; 2630 2631 case SCTP_PARAM_SUPPORTED_EXT: 2632 sctp_process_ext_param(asoc, param); 2633 break; 2634 2635 case SCTP_PARAM_FWD_TSN_SUPPORT: 2636 if (net->sctp.prsctp_enable) { 2637 asoc->peer.prsctp_capable = 1; 2638 break; 2639 } 2640 /* Fall Through */ 2641 goto fall_through; 2642 2643 case SCTP_PARAM_RANDOM: 2644 if (!ep->auth_enable) 2645 goto fall_through; 2646 2647 /* Save peer's random parameter */ 2648 asoc->peer.peer_random = kmemdup(param.p, 2649 ntohs(param.p->length), gfp); 2650 if (!asoc->peer.peer_random) { 2651 retval = 0; 2652 break; 2653 } 2654 break; 2655 2656 case SCTP_PARAM_HMAC_ALGO: 2657 if (!ep->auth_enable) 2658 goto fall_through; 2659 2660 /* Save peer's HMAC list */ 2661 asoc->peer.peer_hmacs = kmemdup(param.p, 2662 ntohs(param.p->length), gfp); 2663 if (!asoc->peer.peer_hmacs) { 2664 retval = 0; 2665 break; 2666 } 2667 2668 /* Set the default HMAC the peer requested*/ 2669 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2670 break; 2671 2672 case SCTP_PARAM_CHUNKS: 2673 if (!ep->auth_enable) 2674 goto fall_through; 2675 2676 asoc->peer.peer_chunks = kmemdup(param.p, 2677 ntohs(param.p->length), gfp); 2678 if (!asoc->peer.peer_chunks) 2679 retval = 0; 2680 break; 2681 fall_through: 2682 default: 2683 /* Any unrecognized parameters should have been caught 2684 * and handled by sctp_verify_param() which should be 2685 * called prior to this routine. Simply log the error 2686 * here. 2687 */ 2688 pr_debug("%s: ignoring param:%d for association:%p.\n", 2689 __func__, ntohs(param.p->type), asoc); 2690 break; 2691 } 2692 2693 return retval; 2694 } 2695 2696 /* Select a new verification tag. */ 2697 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2698 { 2699 /* I believe that this random number generator complies with RFC1750. 2700 * A tag of 0 is reserved for special cases (e.g. INIT). 2701 */ 2702 __u32 x; 2703 2704 do { 2705 get_random_bytes(&x, sizeof(__u32)); 2706 } while (x == 0); 2707 2708 return x; 2709 } 2710 2711 /* Select an initial TSN to send during startup. */ 2712 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2713 { 2714 __u32 retval; 2715 2716 get_random_bytes(&retval, sizeof(__u32)); 2717 return retval; 2718 } 2719 2720 /* 2721 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2722 * 0 1 2 3 2723 * 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 2724 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2725 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2726 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2727 * | Serial Number | 2728 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2729 * | Address Parameter | 2730 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2731 * | ASCONF Parameter #1 | 2732 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2733 * \ \ 2734 * / .... / 2735 * \ \ 2736 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2737 * | ASCONF Parameter #N | 2738 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2739 * 2740 * Address Parameter and other parameter will not be wrapped in this function 2741 */ 2742 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2743 union sctp_addr *addr, 2744 int vparam_len) 2745 { 2746 sctp_addiphdr_t asconf; 2747 struct sctp_chunk *retval; 2748 int length = sizeof(asconf) + vparam_len; 2749 union sctp_addr_param addrparam; 2750 int addrlen; 2751 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2752 2753 addrlen = af->to_addr_param(addr, &addrparam); 2754 if (!addrlen) 2755 return NULL; 2756 length += addrlen; 2757 2758 /* Create the chunk. */ 2759 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length); 2760 if (!retval) 2761 return NULL; 2762 2763 asconf.serial = htonl(asoc->addip_serial++); 2764 2765 retval->subh.addip_hdr = 2766 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2767 retval->param_hdr.v = 2768 sctp_addto_chunk(retval, addrlen, &addrparam); 2769 2770 return retval; 2771 } 2772 2773 /* ADDIP 2774 * 3.2.1 Add IP Address 2775 * 0 1 2 3 2776 * 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 2777 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2778 * | Type = 0xC001 | Length = Variable | 2779 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2780 * | ASCONF-Request Correlation ID | 2781 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2782 * | Address Parameter | 2783 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2784 * 2785 * 3.2.2 Delete IP Address 2786 * 0 1 2 3 2787 * 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 2788 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2789 * | Type = 0xC002 | Length = Variable | 2790 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2791 * | ASCONF-Request Correlation ID | 2792 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2793 * | Address Parameter | 2794 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2795 * 2796 */ 2797 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2798 union sctp_addr *laddr, 2799 struct sockaddr *addrs, 2800 int addrcnt, 2801 __be16 flags) 2802 { 2803 sctp_addip_param_t param; 2804 struct sctp_chunk *retval; 2805 union sctp_addr_param addr_param; 2806 union sctp_addr *addr; 2807 void *addr_buf; 2808 struct sctp_af *af; 2809 int paramlen = sizeof(param); 2810 int addr_param_len = 0; 2811 int totallen = 0; 2812 int i; 2813 int del_pickup = 0; 2814 2815 /* Get total length of all the address parameters. */ 2816 addr_buf = addrs; 2817 for (i = 0; i < addrcnt; i++) { 2818 addr = addr_buf; 2819 af = sctp_get_af_specific(addr->v4.sin_family); 2820 addr_param_len = af->to_addr_param(addr, &addr_param); 2821 2822 totallen += paramlen; 2823 totallen += addr_param_len; 2824 2825 addr_buf += af->sockaddr_len; 2826 if (asoc->asconf_addr_del_pending && !del_pickup) { 2827 /* reuse the parameter length from the same scope one */ 2828 totallen += paramlen; 2829 totallen += addr_param_len; 2830 del_pickup = 1; 2831 2832 pr_debug("%s: picked same-scope del_pending addr, " 2833 "totallen for all addresses is %d\n", 2834 __func__, totallen); 2835 } 2836 } 2837 2838 /* Create an asconf chunk with the required length. */ 2839 retval = sctp_make_asconf(asoc, laddr, totallen); 2840 if (!retval) 2841 return NULL; 2842 2843 /* Add the address parameters to the asconf chunk. */ 2844 addr_buf = addrs; 2845 for (i = 0; i < addrcnt; i++) { 2846 addr = addr_buf; 2847 af = sctp_get_af_specific(addr->v4.sin_family); 2848 addr_param_len = af->to_addr_param(addr, &addr_param); 2849 param.param_hdr.type = flags; 2850 param.param_hdr.length = htons(paramlen + addr_param_len); 2851 param.crr_id = i; 2852 2853 sctp_addto_chunk(retval, paramlen, ¶m); 2854 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2855 2856 addr_buf += af->sockaddr_len; 2857 } 2858 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2859 addr = asoc->asconf_addr_del_pending; 2860 af = sctp_get_af_specific(addr->v4.sin_family); 2861 addr_param_len = af->to_addr_param(addr, &addr_param); 2862 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2863 param.param_hdr.length = htons(paramlen + addr_param_len); 2864 param.crr_id = i; 2865 2866 sctp_addto_chunk(retval, paramlen, ¶m); 2867 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2868 } 2869 return retval; 2870 } 2871 2872 /* ADDIP 2873 * 3.2.4 Set Primary IP Address 2874 * 0 1 2 3 2875 * 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 2876 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2877 * | Type =0xC004 | Length = Variable | 2878 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2879 * | ASCONF-Request Correlation ID | 2880 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2881 * | Address Parameter | 2882 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2883 * 2884 * Create an ASCONF chunk with Set Primary IP address parameter. 2885 */ 2886 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2887 union sctp_addr *addr) 2888 { 2889 sctp_addip_param_t param; 2890 struct sctp_chunk *retval; 2891 int len = sizeof(param); 2892 union sctp_addr_param addrparam; 2893 int addrlen; 2894 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2895 2896 addrlen = af->to_addr_param(addr, &addrparam); 2897 if (!addrlen) 2898 return NULL; 2899 len += addrlen; 2900 2901 /* Create the chunk and make asconf header. */ 2902 retval = sctp_make_asconf(asoc, addr, len); 2903 if (!retval) 2904 return NULL; 2905 2906 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2907 param.param_hdr.length = htons(len); 2908 param.crr_id = 0; 2909 2910 sctp_addto_chunk(retval, sizeof(param), ¶m); 2911 sctp_addto_chunk(retval, addrlen, &addrparam); 2912 2913 return retval; 2914 } 2915 2916 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2917 * 0 1 2 3 2918 * 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 2919 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2920 * | Type = 0x80 | Chunk Flags | Chunk Length | 2921 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2922 * | Serial Number | 2923 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2924 * | ASCONF Parameter Response#1 | 2925 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2926 * \ \ 2927 * / .... / 2928 * \ \ 2929 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2930 * | ASCONF Parameter Response#N | 2931 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2932 * 2933 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2934 */ 2935 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2936 __u32 serial, int vparam_len) 2937 { 2938 sctp_addiphdr_t asconf; 2939 struct sctp_chunk *retval; 2940 int length = sizeof(asconf) + vparam_len; 2941 2942 /* Create the chunk. */ 2943 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length); 2944 if (!retval) 2945 return NULL; 2946 2947 asconf.serial = htonl(serial); 2948 2949 retval->subh.addip_hdr = 2950 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2951 2952 return retval; 2953 } 2954 2955 /* Add response parameters to an ASCONF_ACK chunk. */ 2956 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2957 __be16 err_code, sctp_addip_param_t *asconf_param) 2958 { 2959 sctp_addip_param_t ack_param; 2960 sctp_errhdr_t err_param; 2961 int asconf_param_len = 0; 2962 int err_param_len = 0; 2963 __be16 response_type; 2964 2965 if (SCTP_ERROR_NO_ERROR == err_code) { 2966 response_type = SCTP_PARAM_SUCCESS_REPORT; 2967 } else { 2968 response_type = SCTP_PARAM_ERR_CAUSE; 2969 err_param_len = sizeof(err_param); 2970 if (asconf_param) 2971 asconf_param_len = 2972 ntohs(asconf_param->param_hdr.length); 2973 } 2974 2975 /* Add Success Indication or Error Cause Indication parameter. */ 2976 ack_param.param_hdr.type = response_type; 2977 ack_param.param_hdr.length = htons(sizeof(ack_param) + 2978 err_param_len + 2979 asconf_param_len); 2980 ack_param.crr_id = crr_id; 2981 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 2982 2983 if (SCTP_ERROR_NO_ERROR == err_code) 2984 return; 2985 2986 /* Add Error Cause parameter. */ 2987 err_param.cause = err_code; 2988 err_param.length = htons(err_param_len + asconf_param_len); 2989 sctp_addto_chunk(chunk, err_param_len, &err_param); 2990 2991 /* Add the failed TLV copied from ASCONF chunk. */ 2992 if (asconf_param) 2993 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 2994 } 2995 2996 /* Process a asconf parameter. */ 2997 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 2998 struct sctp_chunk *asconf, 2999 sctp_addip_param_t *asconf_param) 3000 { 3001 struct sctp_transport *peer; 3002 struct sctp_af *af; 3003 union sctp_addr addr; 3004 union sctp_addr_param *addr_param; 3005 3006 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t); 3007 3008 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 3009 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 3010 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 3011 return SCTP_ERROR_UNKNOWN_PARAM; 3012 3013 switch (addr_param->p.type) { 3014 case SCTP_PARAM_IPV6_ADDRESS: 3015 if (!asoc->peer.ipv6_address) 3016 return SCTP_ERROR_DNS_FAILED; 3017 break; 3018 case SCTP_PARAM_IPV4_ADDRESS: 3019 if (!asoc->peer.ipv4_address) 3020 return SCTP_ERROR_DNS_FAILED; 3021 break; 3022 default: 3023 return SCTP_ERROR_DNS_FAILED; 3024 } 3025 3026 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3027 if (unlikely(!af)) 3028 return SCTP_ERROR_DNS_FAILED; 3029 3030 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); 3031 3032 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3033 * or multicast address. 3034 * (note: wildcard is permitted and requires special handling so 3035 * make sure we check for that) 3036 */ 3037 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3038 return SCTP_ERROR_DNS_FAILED; 3039 3040 switch (asconf_param->param_hdr.type) { 3041 case SCTP_PARAM_ADD_IP: 3042 /* Section 4.2.1: 3043 * If the address 0.0.0.0 or ::0 is provided, the source 3044 * address of the packet MUST be added. 3045 */ 3046 if (af->is_any(&addr)) 3047 memcpy(&addr, &asconf->source, sizeof(addr)); 3048 3049 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3050 * request and does not have the local resources to add this 3051 * new address to the association, it MUST return an Error 3052 * Cause TLV set to the new error code 'Operation Refused 3053 * Due to Resource Shortage'. 3054 */ 3055 3056 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3057 if (!peer) 3058 return SCTP_ERROR_RSRC_LOW; 3059 3060 /* Start the heartbeat timer. */ 3061 if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer))) 3062 sctp_transport_hold(peer); 3063 asoc->new_transport = peer; 3064 break; 3065 case SCTP_PARAM_DEL_IP: 3066 /* ADDIP 4.3 D7) If a request is received to delete the 3067 * last remaining IP address of a peer endpoint, the receiver 3068 * MUST send an Error Cause TLV with the error cause set to the 3069 * new error code 'Request to Delete Last Remaining IP Address'. 3070 */ 3071 if (asoc->peer.transport_count == 1) 3072 return SCTP_ERROR_DEL_LAST_IP; 3073 3074 /* ADDIP 4.3 D8) If a request is received to delete an IP 3075 * address which is also the source address of the IP packet 3076 * which contained the ASCONF chunk, the receiver MUST reject 3077 * this request. To reject the request the receiver MUST send 3078 * an Error Cause TLV set to the new error code 'Request to 3079 * Delete Source IP Address' 3080 */ 3081 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3082 return SCTP_ERROR_DEL_SRC_IP; 3083 3084 /* Section 4.2.2 3085 * If the address 0.0.0.0 or ::0 is provided, all 3086 * addresses of the peer except the source address of the 3087 * packet MUST be deleted. 3088 */ 3089 if (af->is_any(&addr)) { 3090 sctp_assoc_set_primary(asoc, asconf->transport); 3091 sctp_assoc_del_nonprimary_peers(asoc, 3092 asconf->transport); 3093 return SCTP_ERROR_NO_ERROR; 3094 } 3095 3096 /* If the address is not part of the association, the 3097 * ASCONF-ACK with Error Cause Indication Parameter 3098 * which including cause of Unresolvable Address should 3099 * be sent. 3100 */ 3101 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3102 if (!peer) 3103 return SCTP_ERROR_DNS_FAILED; 3104 3105 sctp_assoc_rm_peer(asoc, peer); 3106 break; 3107 case SCTP_PARAM_SET_PRIMARY: 3108 /* ADDIP Section 4.2.4 3109 * If the address 0.0.0.0 or ::0 is provided, the receiver 3110 * MAY mark the source address of the packet as its 3111 * primary. 3112 */ 3113 if (af->is_any(&addr)) 3114 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr)); 3115 3116 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3117 if (!peer) 3118 return SCTP_ERROR_DNS_FAILED; 3119 3120 sctp_assoc_set_primary(asoc, peer); 3121 break; 3122 } 3123 3124 return SCTP_ERROR_NO_ERROR; 3125 } 3126 3127 /* Verify the ASCONF packet before we process it. */ 3128 bool sctp_verify_asconf(const struct sctp_association *asoc, 3129 struct sctp_chunk *chunk, bool addr_param_needed, 3130 struct sctp_paramhdr **errp) 3131 { 3132 sctp_addip_chunk_t *addip = (sctp_addip_chunk_t *) chunk->chunk_hdr; 3133 union sctp_params param; 3134 bool addr_param_seen = false; 3135 3136 sctp_walk_params(param, addip, addip_hdr.params) { 3137 size_t length = ntohs(param.p->length); 3138 3139 *errp = param.p; 3140 switch (param.p->type) { 3141 case SCTP_PARAM_ERR_CAUSE: 3142 break; 3143 case SCTP_PARAM_IPV4_ADDRESS: 3144 if (length != sizeof(sctp_ipv4addr_param_t)) 3145 return false; 3146 /* ensure there is only one addr param and it's in the 3147 * beginning of addip_hdr params, or we reject it. 3148 */ 3149 if (param.v != addip->addip_hdr.params) 3150 return false; 3151 addr_param_seen = true; 3152 break; 3153 case SCTP_PARAM_IPV6_ADDRESS: 3154 if (length != sizeof(sctp_ipv6addr_param_t)) 3155 return false; 3156 if (param.v != addip->addip_hdr.params) 3157 return false; 3158 addr_param_seen = true; 3159 break; 3160 case SCTP_PARAM_ADD_IP: 3161 case SCTP_PARAM_DEL_IP: 3162 case SCTP_PARAM_SET_PRIMARY: 3163 /* In ASCONF chunks, these need to be first. */ 3164 if (addr_param_needed && !addr_param_seen) 3165 return false; 3166 length = ntohs(param.addip->param_hdr.length); 3167 if (length < sizeof(sctp_addip_param_t) + 3168 sizeof(sctp_paramhdr_t)) 3169 return false; 3170 break; 3171 case SCTP_PARAM_SUCCESS_REPORT: 3172 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3173 if (length != sizeof(sctp_addip_param_t)) 3174 return false; 3175 break; 3176 default: 3177 /* This is unkown to us, reject! */ 3178 return false; 3179 } 3180 } 3181 3182 /* Remaining sanity checks. */ 3183 if (addr_param_needed && !addr_param_seen) 3184 return false; 3185 if (!addr_param_needed && addr_param_seen) 3186 return false; 3187 if (param.v != chunk->chunk_end) 3188 return false; 3189 3190 return true; 3191 } 3192 3193 /* Process an incoming ASCONF chunk with the next expected serial no. and 3194 * return an ASCONF_ACK chunk to be sent in response. 3195 */ 3196 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3197 struct sctp_chunk *asconf) 3198 { 3199 sctp_addip_chunk_t *addip = (sctp_addip_chunk_t *) asconf->chunk_hdr; 3200 bool all_param_pass = true; 3201 union sctp_params param; 3202 sctp_addiphdr_t *hdr; 3203 union sctp_addr_param *addr_param; 3204 sctp_addip_param_t *asconf_param; 3205 struct sctp_chunk *asconf_ack; 3206 __be16 err_code; 3207 int length = 0; 3208 int chunk_len; 3209 __u32 serial; 3210 3211 chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t); 3212 hdr = (sctp_addiphdr_t *)asconf->skb->data; 3213 serial = ntohl(hdr->serial); 3214 3215 /* Skip the addiphdr and store a pointer to address parameter. */ 3216 length = sizeof(sctp_addiphdr_t); 3217 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3218 chunk_len -= length; 3219 3220 /* Skip the address parameter and store a pointer to the first 3221 * asconf parameter. 3222 */ 3223 length = ntohs(addr_param->p.length); 3224 asconf_param = (void *)addr_param + length; 3225 chunk_len -= length; 3226 3227 /* create an ASCONF_ACK chunk. 3228 * Based on the definitions of parameters, we know that the size of 3229 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3230 * parameters. 3231 */ 3232 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3233 if (!asconf_ack) 3234 goto done; 3235 3236 /* Process the TLVs contained within the ASCONF chunk. */ 3237 sctp_walk_params(param, addip, addip_hdr.params) { 3238 /* Skip preceeding address parameters. */ 3239 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 3240 param.p->type == SCTP_PARAM_IPV6_ADDRESS) 3241 continue; 3242 3243 err_code = sctp_process_asconf_param(asoc, asconf, 3244 param.addip); 3245 /* ADDIP 4.1 A7) 3246 * If an error response is received for a TLV parameter, 3247 * all TLVs with no response before the failed TLV are 3248 * considered successful if not reported. All TLVs after 3249 * the failed response are considered unsuccessful unless 3250 * a specific success indication is present for the parameter. 3251 */ 3252 if (err_code != SCTP_ERROR_NO_ERROR) 3253 all_param_pass = false; 3254 if (!all_param_pass) 3255 sctp_add_asconf_response(asconf_ack, param.addip->crr_id, 3256 err_code, param.addip); 3257 3258 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3259 * an IP address sends an 'Out of Resource' in its response, it 3260 * MUST also fail any subsequent add or delete requests bundled 3261 * in the ASCONF. 3262 */ 3263 if (err_code == SCTP_ERROR_RSRC_LOW) 3264 goto done; 3265 } 3266 done: 3267 asoc->peer.addip_serial++; 3268 3269 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3270 * after freeing the reference to old asconf ack if any. 3271 */ 3272 if (asconf_ack) { 3273 sctp_chunk_hold(asconf_ack); 3274 list_add_tail(&asconf_ack->transmitted_list, 3275 &asoc->asconf_ack_list); 3276 } 3277 3278 return asconf_ack; 3279 } 3280 3281 /* Process a asconf parameter that is successfully acked. */ 3282 static void sctp_asconf_param_success(struct sctp_association *asoc, 3283 sctp_addip_param_t *asconf_param) 3284 { 3285 struct sctp_af *af; 3286 union sctp_addr addr; 3287 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3288 union sctp_addr_param *addr_param; 3289 struct sctp_transport *transport; 3290 struct sctp_sockaddr_entry *saddr; 3291 3292 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t); 3293 3294 /* We have checked the packet before, so we do not check again. */ 3295 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3296 af->from_addr_param(&addr, addr_param, htons(bp->port), 0); 3297 3298 switch (asconf_param->param_hdr.type) { 3299 case SCTP_PARAM_ADD_IP: 3300 /* This is always done in BH context with a socket lock 3301 * held, so the list can not change. 3302 */ 3303 local_bh_disable(); 3304 list_for_each_entry(saddr, &bp->address_list, list) { 3305 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3306 saddr->state = SCTP_ADDR_SRC; 3307 } 3308 local_bh_enable(); 3309 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3310 transports) { 3311 dst_release(transport->dst); 3312 transport->dst = NULL; 3313 } 3314 break; 3315 case SCTP_PARAM_DEL_IP: 3316 local_bh_disable(); 3317 sctp_del_bind_addr(bp, &addr); 3318 if (asoc->asconf_addr_del_pending != NULL && 3319 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3320 kfree(asoc->asconf_addr_del_pending); 3321 asoc->asconf_addr_del_pending = NULL; 3322 } 3323 local_bh_enable(); 3324 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3325 transports) { 3326 dst_release(transport->dst); 3327 transport->dst = NULL; 3328 } 3329 break; 3330 default: 3331 break; 3332 } 3333 } 3334 3335 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3336 * for the given asconf parameter. If there is no response for this parameter, 3337 * return the error code based on the third argument 'no_err'. 3338 * ADDIP 4.1 3339 * A7) If an error response is received for a TLV parameter, all TLVs with no 3340 * response before the failed TLV are considered successful if not reported. 3341 * All TLVs after the failed response are considered unsuccessful unless a 3342 * specific success indication is present for the parameter. 3343 */ 3344 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3345 sctp_addip_param_t *asconf_param, 3346 int no_err) 3347 { 3348 sctp_addip_param_t *asconf_ack_param; 3349 sctp_errhdr_t *err_param; 3350 int length; 3351 int asconf_ack_len; 3352 __be16 err_code; 3353 3354 if (no_err) 3355 err_code = SCTP_ERROR_NO_ERROR; 3356 else 3357 err_code = SCTP_ERROR_REQ_REFUSED; 3358 3359 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3360 sizeof(sctp_chunkhdr_t); 3361 3362 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3363 * the first asconf_ack parameter. 3364 */ 3365 length = sizeof(sctp_addiphdr_t); 3366 asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data + 3367 length); 3368 asconf_ack_len -= length; 3369 3370 while (asconf_ack_len > 0) { 3371 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3372 switch (asconf_ack_param->param_hdr.type) { 3373 case SCTP_PARAM_SUCCESS_REPORT: 3374 return SCTP_ERROR_NO_ERROR; 3375 case SCTP_PARAM_ERR_CAUSE: 3376 length = sizeof(sctp_addip_param_t); 3377 err_param = (void *)asconf_ack_param + length; 3378 asconf_ack_len -= length; 3379 if (asconf_ack_len > 0) 3380 return err_param->cause; 3381 else 3382 return SCTP_ERROR_INV_PARAM; 3383 break; 3384 default: 3385 return SCTP_ERROR_INV_PARAM; 3386 } 3387 } 3388 3389 length = ntohs(asconf_ack_param->param_hdr.length); 3390 asconf_ack_param = (void *)asconf_ack_param + length; 3391 asconf_ack_len -= length; 3392 } 3393 3394 return err_code; 3395 } 3396 3397 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3398 int sctp_process_asconf_ack(struct sctp_association *asoc, 3399 struct sctp_chunk *asconf_ack) 3400 { 3401 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3402 union sctp_addr_param *addr_param; 3403 sctp_addip_param_t *asconf_param; 3404 int length = 0; 3405 int asconf_len = asconf->skb->len; 3406 int all_param_pass = 0; 3407 int no_err = 1; 3408 int retval = 0; 3409 __be16 err_code = SCTP_ERROR_NO_ERROR; 3410 3411 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3412 * a pointer to address parameter. 3413 */ 3414 length = sizeof(sctp_addip_chunk_t); 3415 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3416 asconf_len -= length; 3417 3418 /* Skip the address parameter in the last asconf sent and store a 3419 * pointer to the first asconf parameter. 3420 */ 3421 length = ntohs(addr_param->p.length); 3422 asconf_param = (void *)addr_param + length; 3423 asconf_len -= length; 3424 3425 /* ADDIP 4.1 3426 * A8) If there is no response(s) to specific TLV parameter(s), and no 3427 * failures are indicated, then all request(s) are considered 3428 * successful. 3429 */ 3430 if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t)) 3431 all_param_pass = 1; 3432 3433 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3434 while (asconf_len > 0) { 3435 if (all_param_pass) 3436 err_code = SCTP_ERROR_NO_ERROR; 3437 else { 3438 err_code = sctp_get_asconf_response(asconf_ack, 3439 asconf_param, 3440 no_err); 3441 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3442 no_err = 0; 3443 } 3444 3445 switch (err_code) { 3446 case SCTP_ERROR_NO_ERROR: 3447 sctp_asconf_param_success(asoc, asconf_param); 3448 break; 3449 3450 case SCTP_ERROR_RSRC_LOW: 3451 retval = 1; 3452 break; 3453 3454 case SCTP_ERROR_UNKNOWN_PARAM: 3455 /* Disable sending this type of asconf parameter in 3456 * future. 3457 */ 3458 asoc->peer.addip_disabled_mask |= 3459 asconf_param->param_hdr.type; 3460 break; 3461 3462 case SCTP_ERROR_REQ_REFUSED: 3463 case SCTP_ERROR_DEL_LAST_IP: 3464 case SCTP_ERROR_DEL_SRC_IP: 3465 default: 3466 break; 3467 } 3468 3469 /* Skip the processed asconf parameter and move to the next 3470 * one. 3471 */ 3472 length = ntohs(asconf_param->param_hdr.length); 3473 asconf_param = (void *)asconf_param + length; 3474 asconf_len -= length; 3475 } 3476 3477 if (no_err && asoc->src_out_of_asoc_ok) { 3478 asoc->src_out_of_asoc_ok = 0; 3479 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3480 } 3481 3482 /* Free the cached last sent asconf chunk. */ 3483 list_del_init(&asconf->transmitted_list); 3484 sctp_chunk_free(asconf); 3485 asoc->addip_last_asconf = NULL; 3486 3487 return retval; 3488 } 3489 3490 /* Make a FWD TSN chunk. */ 3491 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3492 __u32 new_cum_tsn, size_t nstreams, 3493 struct sctp_fwdtsn_skip *skiplist) 3494 { 3495 struct sctp_chunk *retval = NULL; 3496 struct sctp_fwdtsn_hdr ftsn_hdr; 3497 struct sctp_fwdtsn_skip skip; 3498 size_t hint; 3499 int i; 3500 3501 hint = (nstreams + 1) * sizeof(__u32); 3502 3503 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint); 3504 3505 if (!retval) 3506 return NULL; 3507 3508 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3509 retval->subh.fwdtsn_hdr = 3510 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3511 3512 for (i = 0; i < nstreams; i++) { 3513 skip.stream = skiplist[i].stream; 3514 skip.ssn = skiplist[i].ssn; 3515 sctp_addto_chunk(retval, sizeof(skip), &skip); 3516 } 3517 3518 return retval; 3519 } 3520