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, write to 27 * the Free Software Foundation, 59 Temple Place - Suite 330, 28 * Boston, MA 02111-1307, USA. 29 * 30 * Please send any bug reports or fixes you make to the 31 * email address(es): 32 * lksctp developers <linux-sctp@vger.kernel.org> 33 * 34 * Written or modified by: 35 * La Monte H.P. Yarroll <piggy@acm.org> 36 * Karl Knutson <karl@athena.chicago.il.us> 37 * C. Robin <chris@hundredacre.ac.uk> 38 * Jon Grimm <jgrimm@us.ibm.com> 39 * Xingang Guo <xingang.guo@intel.com> 40 * Dajiang Zhang <dajiang.zhang@nokia.com> 41 * Sridhar Samudrala <sri@us.ibm.com> 42 * Daisy Chang <daisyc@us.ibm.com> 43 * Ardelle Fan <ardelle.fan@intel.com> 44 * Kevin Gao <kevin.gao@intel.com> 45 */ 46 47 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 48 49 #include <linux/types.h> 50 #include <linux/kernel.h> 51 #include <linux/ip.h> 52 #include <linux/ipv6.h> 53 #include <linux/net.h> 54 #include <linux/inet.h> 55 #include <linux/scatterlist.h> 56 #include <linux/crypto.h> 57 #include <linux/slab.h> 58 #include <net/sock.h> 59 60 #include <linux/skbuff.h> 61 #include <linux/random.h> /* for get_random_bytes */ 62 #include <net/sctp/sctp.h> 63 #include <net/sctp/sm.h> 64 65 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 66 __u8 type, __u8 flags, int paylen); 67 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 68 __u8 flags, int paylen); 69 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 70 __u8 type, __u8 flags, int paylen); 71 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, 72 const struct sctp_association *asoc, 73 const struct sctp_chunk *init_chunk, 74 int *cookie_len, 75 const __u8 *raw_addrs, int addrs_len); 76 static int sctp_process_param(struct sctp_association *asoc, 77 union sctp_params param, 78 const union sctp_addr *peer_addr, 79 gfp_t gfp); 80 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 81 const void *data); 82 83 /* Control chunk destructor */ 84 static void sctp_control_release_owner(struct sk_buff *skb) 85 { 86 /*TODO: do memory release */ 87 } 88 89 static void sctp_control_set_owner_w(struct sctp_chunk *chunk) 90 { 91 struct sctp_association *asoc = chunk->asoc; 92 struct sk_buff *skb = chunk->skb; 93 94 /* TODO: properly account for control chunks. 95 * To do it right we'll need: 96 * 1) endpoint if association isn't known. 97 * 2) proper memory accounting. 98 * 99 * For now don't do anything for now. 100 */ 101 skb->sk = asoc ? asoc->base.sk : NULL; 102 skb->destructor = sctp_control_release_owner; 103 } 104 105 /* What was the inbound interface for this chunk? */ 106 int sctp_chunk_iif(const struct sctp_chunk *chunk) 107 { 108 struct sctp_af *af; 109 int iif = 0; 110 111 af = sctp_get_af_specific(ipver2af(ip_hdr(chunk->skb)->version)); 112 if (af) 113 iif = af->skb_iif(chunk->skb); 114 115 return iif; 116 } 117 118 /* RFC 2960 3.3.2 Initiation (INIT) (1) 119 * 120 * Note 2: The ECN capable field is reserved for future use of 121 * Explicit Congestion Notification. 122 */ 123 static const struct sctp_paramhdr ecap_param = { 124 SCTP_PARAM_ECN_CAPABLE, 125 cpu_to_be16(sizeof(struct sctp_paramhdr)), 126 }; 127 static const struct sctp_paramhdr prsctp_param = { 128 SCTP_PARAM_FWD_TSN_SUPPORT, 129 cpu_to_be16(sizeof(struct sctp_paramhdr)), 130 }; 131 132 /* A helper to initialize an op error inside a 133 * provided chunk, as most cause codes will be embedded inside an 134 * abort chunk. 135 */ 136 void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, 137 size_t paylen) 138 { 139 sctp_errhdr_t err; 140 __u16 len; 141 142 /* Cause code constants are now defined in network order. */ 143 err.cause = cause_code; 144 len = sizeof(sctp_errhdr_t) + paylen; 145 err.length = htons(len); 146 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err); 147 } 148 149 /* A helper to initialize an op error inside a 150 * provided chunk, as most cause codes will be embedded inside an 151 * abort chunk. Differs from sctp_init_cause in that it won't oops 152 * if there isn't enough space in the op error chunk 153 */ 154 static int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code, 155 size_t paylen) 156 { 157 sctp_errhdr_t err; 158 __u16 len; 159 160 /* Cause code constants are now defined in network order. */ 161 err.cause = cause_code; 162 len = sizeof(sctp_errhdr_t) + paylen; 163 err.length = htons(len); 164 165 if (skb_tailroom(chunk->skb) < len) 166 return -ENOSPC; 167 chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk, 168 sizeof(sctp_errhdr_t), 169 &err); 170 return 0; 171 } 172 /* 3.3.2 Initiation (INIT) (1) 173 * 174 * This chunk is used to initiate a SCTP association between two 175 * endpoints. The format of the INIT chunk is shown below: 176 * 177 * 0 1 2 3 178 * 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 1 179 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 180 * | Type = 1 | Chunk Flags | Chunk Length | 181 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 182 * | Initiate Tag | 183 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 184 * | Advertised Receiver Window Credit (a_rwnd) | 185 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 186 * | Number of Outbound Streams | Number of Inbound Streams | 187 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 188 * | Initial TSN | 189 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 190 * \ \ 191 * / Optional/Variable-Length Parameters / 192 * \ \ 193 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 194 * 195 * 196 * The INIT chunk contains the following parameters. Unless otherwise 197 * noted, each parameter MUST only be included once in the INIT chunk. 198 * 199 * Fixed Parameters Status 200 * ---------------------------------------------- 201 * Initiate Tag Mandatory 202 * Advertised Receiver Window Credit Mandatory 203 * Number of Outbound Streams Mandatory 204 * Number of Inbound Streams Mandatory 205 * Initial TSN Mandatory 206 * 207 * Variable Parameters Status Type Value 208 * ------------------------------------------------------------- 209 * IPv4 Address (Note 1) Optional 5 210 * IPv6 Address (Note 1) Optional 6 211 * Cookie Preservative Optional 9 212 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000) 213 * Host Name Address (Note 3) Optional 11 214 * Supported Address Types (Note 4) Optional 12 215 */ 216 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc, 217 const struct sctp_bind_addr *bp, 218 gfp_t gfp, int vparam_len) 219 { 220 struct net *net = sock_net(asoc->base.sk); 221 sctp_inithdr_t init; 222 union sctp_params addrs; 223 size_t chunksize; 224 struct sctp_chunk *retval = NULL; 225 int num_types, addrs_len = 0; 226 struct sctp_sock *sp; 227 sctp_supported_addrs_param_t sat; 228 __be16 types[2]; 229 sctp_adaptation_ind_param_t aiparam; 230 sctp_supported_ext_param_t ext_param; 231 int num_ext = 0; 232 __u8 extensions[3]; 233 sctp_paramhdr_t *auth_chunks = NULL, 234 *auth_hmacs = NULL; 235 236 /* RFC 2960 3.3.2 Initiation (INIT) (1) 237 * 238 * Note 1: The INIT chunks can contain multiple addresses that 239 * can be IPv4 and/or IPv6 in any combination. 240 */ 241 retval = NULL; 242 243 /* Convert the provided bind address list to raw format. */ 244 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp); 245 246 init.init_tag = htonl(asoc->c.my_vtag); 247 init.a_rwnd = htonl(asoc->rwnd); 248 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 249 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 250 init.initial_tsn = htonl(asoc->c.initial_tsn); 251 252 /* How many address types are needed? */ 253 sp = sctp_sk(asoc->base.sk); 254 num_types = sp->pf->supported_addrs(sp, types); 255 256 chunksize = sizeof(init) + addrs_len; 257 chunksize += WORD_ROUND(SCTP_SAT_LEN(num_types)); 258 chunksize += sizeof(ecap_param); 259 260 if (net->sctp.prsctp_enable) 261 chunksize += sizeof(prsctp_param); 262 263 /* ADDIP: Section 4.2.7: 264 * An implementation supporting this extension [ADDIP] MUST list 265 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and 266 * INIT-ACK parameters. 267 */ 268 if (net->sctp.addip_enable) { 269 extensions[num_ext] = SCTP_CID_ASCONF; 270 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 271 num_ext += 2; 272 } 273 274 if (sp->adaptation_ind) 275 chunksize += sizeof(aiparam); 276 277 chunksize += vparam_len; 278 279 /* Account for AUTH related parameters */ 280 if (net->sctp.auth_enable) { 281 /* Add random parameter length*/ 282 chunksize += sizeof(asoc->c.auth_random); 283 284 /* Add HMACS parameter length if any were defined */ 285 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs; 286 if (auth_hmacs->length) 287 chunksize += WORD_ROUND(ntohs(auth_hmacs->length)); 288 else 289 auth_hmacs = NULL; 290 291 /* Add CHUNKS parameter length */ 292 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks; 293 if (auth_chunks->length) 294 chunksize += WORD_ROUND(ntohs(auth_chunks->length)); 295 else 296 auth_chunks = NULL; 297 298 extensions[num_ext] = SCTP_CID_AUTH; 299 num_ext += 1; 300 } 301 302 /* If we have any extensions to report, account for that */ 303 if (num_ext) 304 chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) + 305 num_ext); 306 307 /* RFC 2960 3.3.2 Initiation (INIT) (1) 308 * 309 * Note 3: An INIT chunk MUST NOT contain more than one Host 310 * Name address parameter. Moreover, the sender of the INIT 311 * MUST NOT combine any other address types with the Host Name 312 * address in the INIT. The receiver of INIT MUST ignore any 313 * other address types if the Host Name address parameter is 314 * present in the received INIT chunk. 315 * 316 * PLEASE DO NOT FIXME [This version does not support Host Name.] 317 */ 318 319 retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize); 320 if (!retval) 321 goto nodata; 322 323 retval->subh.init_hdr = 324 sctp_addto_chunk(retval, sizeof(init), &init); 325 retval->param_hdr.v = 326 sctp_addto_chunk(retval, addrs_len, addrs.v); 327 328 /* RFC 2960 3.3.2 Initiation (INIT) (1) 329 * 330 * Note 4: This parameter, when present, specifies all the 331 * address types the sending endpoint can support. The absence 332 * of this parameter indicates that the sending endpoint can 333 * support any address type. 334 */ 335 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES; 336 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types)); 337 sctp_addto_chunk(retval, sizeof(sat), &sat); 338 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types); 339 340 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 341 342 /* Add the supported extensions parameter. Be nice and add this 343 * fist before addiding the parameters for the extensions themselves 344 */ 345 if (num_ext) { 346 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 347 ext_param.param_hdr.length = 348 htons(sizeof(sctp_supported_ext_param_t) + num_ext); 349 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t), 350 &ext_param); 351 sctp_addto_param(retval, num_ext, extensions); 352 } 353 354 if (net->sctp.prsctp_enable) 355 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 356 357 if (sp->adaptation_ind) { 358 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 359 aiparam.param_hdr.length = htons(sizeof(aiparam)); 360 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 361 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 362 } 363 364 /* Add SCTP-AUTH chunks to the parameter list */ 365 if (net->sctp.auth_enable) { 366 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random), 367 asoc->c.auth_random); 368 if (auth_hmacs) 369 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 370 auth_hmacs); 371 if (auth_chunks) 372 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 373 auth_chunks); 374 } 375 nodata: 376 kfree(addrs.v); 377 return retval; 378 } 379 380 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, 381 const struct sctp_chunk *chunk, 382 gfp_t gfp, int unkparam_len) 383 { 384 sctp_inithdr_t initack; 385 struct sctp_chunk *retval; 386 union sctp_params addrs; 387 struct sctp_sock *sp; 388 int addrs_len; 389 sctp_cookie_param_t *cookie; 390 int cookie_len; 391 size_t chunksize; 392 sctp_adaptation_ind_param_t aiparam; 393 sctp_supported_ext_param_t ext_param; 394 int num_ext = 0; 395 __u8 extensions[3]; 396 sctp_paramhdr_t *auth_chunks = NULL, 397 *auth_hmacs = NULL, 398 *auth_random = NULL; 399 400 retval = NULL; 401 402 /* Note: there may be no addresses to embed. */ 403 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp); 404 405 initack.init_tag = htonl(asoc->c.my_vtag); 406 initack.a_rwnd = htonl(asoc->rwnd); 407 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 408 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 409 initack.initial_tsn = htonl(asoc->c.initial_tsn); 410 411 /* FIXME: We really ought to build the cookie right 412 * into the packet instead of allocating more fresh memory. 413 */ 414 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len, 415 addrs.v, addrs_len); 416 if (!cookie) 417 goto nomem_cookie; 418 419 /* Calculate the total size of allocation, include the reserved 420 * space for reporting unknown parameters if it is specified. 421 */ 422 sp = sctp_sk(asoc->base.sk); 423 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len; 424 425 /* Tell peer that we'll do ECN only if peer advertised such cap. */ 426 if (asoc->peer.ecn_capable) 427 chunksize += sizeof(ecap_param); 428 429 if (asoc->peer.prsctp_capable) 430 chunksize += sizeof(prsctp_param); 431 432 if (asoc->peer.asconf_capable) { 433 extensions[num_ext] = SCTP_CID_ASCONF; 434 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 435 num_ext += 2; 436 } 437 438 if (sp->adaptation_ind) 439 chunksize += sizeof(aiparam); 440 441 if (asoc->peer.auth_capable) { 442 auth_random = (sctp_paramhdr_t *)asoc->c.auth_random; 443 chunksize += ntohs(auth_random->length); 444 445 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs; 446 if (auth_hmacs->length) 447 chunksize += WORD_ROUND(ntohs(auth_hmacs->length)); 448 else 449 auth_hmacs = NULL; 450 451 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks; 452 if (auth_chunks->length) 453 chunksize += WORD_ROUND(ntohs(auth_chunks->length)); 454 else 455 auth_chunks = NULL; 456 457 extensions[num_ext] = SCTP_CID_AUTH; 458 num_ext += 1; 459 } 460 461 if (num_ext) 462 chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) + 463 num_ext); 464 465 /* Now allocate and fill out the chunk. */ 466 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize); 467 if (!retval) 468 goto nomem_chunk; 469 470 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 471 * 472 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 473 * HEARTBEAT ACK, * etc.) to the same destination transport 474 * address from which it received the DATA or control chunk 475 * to which it is replying. 476 * 477 * [INIT ACK back to where the INIT came from.] 478 */ 479 retval->transport = chunk->transport; 480 481 retval->subh.init_hdr = 482 sctp_addto_chunk(retval, sizeof(initack), &initack); 483 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); 484 sctp_addto_chunk(retval, cookie_len, cookie); 485 if (asoc->peer.ecn_capable) 486 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 487 if (num_ext) { 488 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 489 ext_param.param_hdr.length = 490 htons(sizeof(sctp_supported_ext_param_t) + num_ext); 491 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t), 492 &ext_param); 493 sctp_addto_param(retval, num_ext, extensions); 494 } 495 if (asoc->peer.prsctp_capable) 496 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 497 498 if (sp->adaptation_ind) { 499 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 500 aiparam.param_hdr.length = htons(sizeof(aiparam)); 501 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 502 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 503 } 504 505 if (asoc->peer.auth_capable) { 506 sctp_addto_chunk(retval, ntohs(auth_random->length), 507 auth_random); 508 if (auth_hmacs) 509 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 510 auth_hmacs); 511 if (auth_chunks) 512 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 513 auth_chunks); 514 } 515 516 /* We need to remove the const qualifier at this point. */ 517 retval->asoc = (struct sctp_association *) asoc; 518 519 nomem_chunk: 520 kfree(cookie); 521 nomem_cookie: 522 kfree(addrs.v); 523 return retval; 524 } 525 526 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10): 527 * 528 * This chunk is used only during the initialization of an association. 529 * It is sent by the initiator of an association to its peer to complete 530 * the initialization process. This chunk MUST precede any DATA chunk 531 * sent within the association, but MAY be bundled with one or more DATA 532 * chunks in the same packet. 533 * 534 * 0 1 2 3 535 * 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 1 536 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 537 * | Type = 10 |Chunk Flags | Length | 538 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 539 * / Cookie / 540 * \ \ 541 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 542 * 543 * Chunk Flags: 8 bit 544 * 545 * Set to zero on transmit and ignored on receipt. 546 * 547 * Length: 16 bits (unsigned integer) 548 * 549 * Set to the size of the chunk in bytes, including the 4 bytes of 550 * the chunk header and the size of the Cookie. 551 * 552 * Cookie: variable size 553 * 554 * This field must contain the exact cookie received in the 555 * State Cookie parameter from the previous INIT ACK. 556 * 557 * An implementation SHOULD make the cookie as small as possible 558 * to insure interoperability. 559 */ 560 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, 561 const struct sctp_chunk *chunk) 562 { 563 struct sctp_chunk *retval; 564 void *cookie; 565 int cookie_len; 566 567 cookie = asoc->peer.cookie; 568 cookie_len = asoc->peer.cookie_len; 569 570 /* Build a cookie echo chunk. */ 571 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0, cookie_len); 572 if (!retval) 573 goto nodata; 574 retval->subh.cookie_hdr = 575 sctp_addto_chunk(retval, cookie_len, cookie); 576 577 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 578 * 579 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 580 * HEARTBEAT ACK, * etc.) to the same destination transport 581 * address from which it * received the DATA or control chunk 582 * to which it is replying. 583 * 584 * [COOKIE ECHO back to where the INIT ACK came from.] 585 */ 586 if (chunk) 587 retval->transport = chunk->transport; 588 589 nodata: 590 return retval; 591 } 592 593 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11): 594 * 595 * This chunk is used only during the initialization of an 596 * association. It is used to acknowledge the receipt of a COOKIE 597 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent 598 * within the association, but MAY be bundled with one or more DATA 599 * chunks or SACK chunk in the same SCTP packet. 600 * 601 * 0 1 2 3 602 * 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 1 603 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 604 * | Type = 11 |Chunk Flags | Length = 4 | 605 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 606 * 607 * Chunk Flags: 8 bits 608 * 609 * Set to zero on transmit and ignored on receipt. 610 */ 611 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, 612 const struct sctp_chunk *chunk) 613 { 614 struct sctp_chunk *retval; 615 616 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0); 617 618 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 619 * 620 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 621 * HEARTBEAT ACK, * etc.) to the same destination transport 622 * address from which it * received the DATA or control chunk 623 * to which it is replying. 624 * 625 * [COOKIE ACK back to where the COOKIE ECHO came from.] 626 */ 627 if (retval && chunk) 628 retval->transport = chunk->transport; 629 630 return retval; 631 } 632 633 /* 634 * Appendix A: Explicit Congestion Notification: 635 * CWR: 636 * 637 * RFC 2481 details a specific bit for a sender to send in the header of 638 * its next outbound TCP segment to indicate to its peer that it has 639 * reduced its congestion window. This is termed the CWR bit. For 640 * SCTP the same indication is made by including the CWR chunk. 641 * This chunk contains one data element, i.e. the TSN number that 642 * was sent in the ECNE chunk. This element represents the lowest 643 * TSN number in the datagram that was originally marked with the 644 * CE bit. 645 * 646 * 0 1 2 3 647 * 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 1 648 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 649 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 | 650 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 651 * | Lowest TSN Number | 652 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 653 * 654 * Note: The CWR is considered a Control chunk. 655 */ 656 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, 657 const __u32 lowest_tsn, 658 const struct sctp_chunk *chunk) 659 { 660 struct sctp_chunk *retval; 661 sctp_cwrhdr_t cwr; 662 663 cwr.lowest_tsn = htonl(lowest_tsn); 664 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0, 665 sizeof(sctp_cwrhdr_t)); 666 667 if (!retval) 668 goto nodata; 669 670 retval->subh.ecn_cwr_hdr = 671 sctp_addto_chunk(retval, sizeof(cwr), &cwr); 672 673 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 674 * 675 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 676 * HEARTBEAT ACK, * etc.) to the same destination transport 677 * address from which it * received the DATA or control chunk 678 * to which it is replying. 679 * 680 * [Report a reduced congestion window back to where the ECNE 681 * came from.] 682 */ 683 if (chunk) 684 retval->transport = chunk->transport; 685 686 nodata: 687 return retval; 688 } 689 690 /* Make an ECNE chunk. This is a congestion experienced report. */ 691 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, 692 const __u32 lowest_tsn) 693 { 694 struct sctp_chunk *retval; 695 sctp_ecnehdr_t ecne; 696 697 ecne.lowest_tsn = htonl(lowest_tsn); 698 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0, 699 sizeof(sctp_ecnehdr_t)); 700 if (!retval) 701 goto nodata; 702 retval->subh.ecne_hdr = 703 sctp_addto_chunk(retval, sizeof(ecne), &ecne); 704 705 nodata: 706 return retval; 707 } 708 709 /* Make a DATA chunk for the given association from the provided 710 * parameters. However, do not populate the data payload. 711 */ 712 struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc, 713 const struct sctp_sndrcvinfo *sinfo, 714 int data_len, __u8 flags, __u16 ssn) 715 { 716 struct sctp_chunk *retval; 717 struct sctp_datahdr dp; 718 int chunk_len; 719 720 /* We assign the TSN as LATE as possible, not here when 721 * creating the chunk. 722 */ 723 dp.tsn = 0; 724 dp.stream = htons(sinfo->sinfo_stream); 725 dp.ppid = sinfo->sinfo_ppid; 726 727 /* Set the flags for an unordered send. */ 728 if (sinfo->sinfo_flags & SCTP_UNORDERED) { 729 flags |= SCTP_DATA_UNORDERED; 730 dp.ssn = 0; 731 } else 732 dp.ssn = htons(ssn); 733 734 chunk_len = sizeof(dp) + data_len; 735 retval = sctp_make_data(asoc, flags, chunk_len); 736 if (!retval) 737 goto nodata; 738 739 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp); 740 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo)); 741 742 nodata: 743 return retval; 744 } 745 746 /* Create a selective ackowledgement (SACK) for the given 747 * association. This reports on which TSN's we've seen to date, 748 * including duplicates and gaps. 749 */ 750 struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc) 751 { 752 struct sctp_chunk *retval; 753 struct sctp_sackhdr sack; 754 int len; 755 __u32 ctsn; 756 __u16 num_gabs, num_dup_tsns; 757 struct sctp_association *aptr = (struct sctp_association *)asoc; 758 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; 759 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; 760 struct sctp_transport *trans; 761 762 memset(gabs, 0, sizeof(gabs)); 763 ctsn = sctp_tsnmap_get_ctsn(map); 764 765 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn); 766 767 /* How much room is needed in the chunk? */ 768 num_gabs = sctp_tsnmap_num_gabs(map, gabs); 769 num_dup_tsns = sctp_tsnmap_num_dups(map); 770 771 /* Initialize the SACK header. */ 772 sack.cum_tsn_ack = htonl(ctsn); 773 sack.a_rwnd = htonl(asoc->a_rwnd); 774 sack.num_gap_ack_blocks = htons(num_gabs); 775 sack.num_dup_tsns = htons(num_dup_tsns); 776 777 len = sizeof(sack) 778 + sizeof(struct sctp_gap_ack_block) * num_gabs 779 + sizeof(__u32) * num_dup_tsns; 780 781 /* Create the chunk. */ 782 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len); 783 if (!retval) 784 goto nodata; 785 786 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 787 * 788 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 789 * HEARTBEAT ACK, etc.) to the same destination transport 790 * address from which it received the DATA or control chunk to 791 * which it is replying. This rule should also be followed if 792 * the endpoint is bundling DATA chunks together with the 793 * reply chunk. 794 * 795 * However, when acknowledging multiple DATA chunks received 796 * in packets from different source addresses in a single 797 * SACK, the SACK chunk may be transmitted to one of the 798 * destination transport addresses from which the DATA or 799 * control chunks being acknowledged were received. 800 * 801 * [BUG: We do not implement the following paragraph. 802 * Perhaps we should remember the last transport we used for a 803 * SACK and avoid that (if possible) if we have seen any 804 * duplicates. --piggy] 805 * 806 * When a receiver of a duplicate DATA chunk sends a SACK to a 807 * multi- homed endpoint it MAY be beneficial to vary the 808 * destination address and not use the source address of the 809 * DATA chunk. The reason being that receiving a duplicate 810 * from a multi-homed endpoint might indicate that the return 811 * path (as specified in the source address of the DATA chunk) 812 * for the SACK is broken. 813 * 814 * [Send to the address from which we last received a DATA chunk.] 815 */ 816 retval->transport = asoc->peer.last_data_from; 817 818 retval->subh.sack_hdr = 819 sctp_addto_chunk(retval, sizeof(sack), &sack); 820 821 /* Add the gap ack block information. */ 822 if (num_gabs) 823 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, 824 gabs); 825 826 /* Add the duplicate TSN information. */ 827 if (num_dup_tsns) { 828 aptr->stats.idupchunks += num_dup_tsns; 829 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, 830 sctp_tsnmap_get_dups(map)); 831 } 832 /* Once we have a sack generated, check to see what our sack 833 * generation is, if its 0, reset the transports to 0, and reset 834 * the association generation to 1 835 * 836 * The idea is that zero is never used as a valid generation for the 837 * association so no transport will match after a wrap event like this, 838 * Until the next sack 839 */ 840 if (++aptr->peer.sack_generation == 0) { 841 list_for_each_entry(trans, &asoc->peer.transport_addr_list, 842 transports) 843 trans->sack_generation = 0; 844 aptr->peer.sack_generation = 1; 845 } 846 nodata: 847 return retval; 848 } 849 850 /* Make a SHUTDOWN chunk. */ 851 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 852 const struct sctp_chunk *chunk) 853 { 854 struct sctp_chunk *retval; 855 sctp_shutdownhdr_t shut; 856 __u32 ctsn; 857 858 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 859 shut.cum_tsn_ack = htonl(ctsn); 860 861 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0, 862 sizeof(sctp_shutdownhdr_t)); 863 if (!retval) 864 goto nodata; 865 866 retval->subh.shutdown_hdr = 867 sctp_addto_chunk(retval, sizeof(shut), &shut); 868 869 if (chunk) 870 retval->transport = chunk->transport; 871 nodata: 872 return retval; 873 } 874 875 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 876 const struct sctp_chunk *chunk) 877 { 878 struct sctp_chunk *retval; 879 880 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0); 881 882 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 883 * 884 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 885 * HEARTBEAT ACK, * etc.) to the same destination transport 886 * address from which it * received the DATA or control chunk 887 * to which it is replying. 888 * 889 * [ACK back to where the SHUTDOWN came from.] 890 */ 891 if (retval && chunk) 892 retval->transport = chunk->transport; 893 894 return retval; 895 } 896 897 struct sctp_chunk *sctp_make_shutdown_complete( 898 const struct sctp_association *asoc, 899 const struct sctp_chunk *chunk) 900 { 901 struct sctp_chunk *retval; 902 __u8 flags = 0; 903 904 /* Set the T-bit if we have no association (vtag will be 905 * reflected) 906 */ 907 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; 908 909 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0); 910 911 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 912 * 913 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 914 * HEARTBEAT ACK, * etc.) to the same destination transport 915 * address from which it * received the DATA or control chunk 916 * to which it is replying. 917 * 918 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK 919 * came from.] 920 */ 921 if (retval && chunk) 922 retval->transport = chunk->transport; 923 924 return retval; 925 } 926 927 /* Create an ABORT. Note that we set the T bit if we have no 928 * association, except when responding to an INIT (sctpimpguide 2.41). 929 */ 930 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 931 const struct sctp_chunk *chunk, 932 const size_t hint) 933 { 934 struct sctp_chunk *retval; 935 __u8 flags = 0; 936 937 /* Set the T-bit if we have no association and 'chunk' is not 938 * an INIT (vtag will be reflected). 939 */ 940 if (!asoc) { 941 if (chunk && chunk->chunk_hdr && 942 chunk->chunk_hdr->type == SCTP_CID_INIT) 943 flags = 0; 944 else 945 flags = SCTP_CHUNK_FLAG_T; 946 } 947 948 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint); 949 950 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 951 * 952 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 953 * HEARTBEAT ACK, * etc.) to the same destination transport 954 * address from which it * received the DATA or control chunk 955 * to which it is replying. 956 * 957 * [ABORT back to where the offender came from.] 958 */ 959 if (retval && chunk) 960 retval->transport = chunk->transport; 961 962 return retval; 963 } 964 965 /* Helper to create ABORT with a NO_USER_DATA error. */ 966 struct sctp_chunk *sctp_make_abort_no_data( 967 const struct sctp_association *asoc, 968 const struct sctp_chunk *chunk, __u32 tsn) 969 { 970 struct sctp_chunk *retval; 971 __be32 payload; 972 973 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) 974 + sizeof(tsn)); 975 976 if (!retval) 977 goto no_mem; 978 979 /* Put the tsn back into network byte order. */ 980 payload = htonl(tsn); 981 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload)); 982 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload); 983 984 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 985 * 986 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 987 * HEARTBEAT ACK, * etc.) to the same destination transport 988 * address from which it * received the DATA or control chunk 989 * to which it is replying. 990 * 991 * [ABORT back to where the offender came from.] 992 */ 993 if (chunk) 994 retval->transport = chunk->transport; 995 996 no_mem: 997 return retval; 998 } 999 1000 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ 1001 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 1002 const struct msghdr *msg, 1003 size_t paylen) 1004 { 1005 struct sctp_chunk *retval; 1006 void *payload = NULL; 1007 int err; 1008 1009 retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen); 1010 if (!retval) 1011 goto err_chunk; 1012 1013 if (paylen) { 1014 /* Put the msg_iov together into payload. */ 1015 payload = kmalloc(paylen, GFP_KERNEL); 1016 if (!payload) 1017 goto err_payload; 1018 1019 err = memcpy_fromiovec(payload, msg->msg_iov, paylen); 1020 if (err < 0) 1021 goto err_copy; 1022 } 1023 1024 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); 1025 sctp_addto_chunk(retval, paylen, payload); 1026 1027 if (paylen) 1028 kfree(payload); 1029 1030 return retval; 1031 1032 err_copy: 1033 kfree(payload); 1034 err_payload: 1035 sctp_chunk_free(retval); 1036 retval = NULL; 1037 err_chunk: 1038 return retval; 1039 } 1040 1041 /* Append bytes to the end of a parameter. Will panic if chunk is not big 1042 * enough. 1043 */ 1044 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 1045 const void *data) 1046 { 1047 void *target; 1048 int chunklen = ntohs(chunk->chunk_hdr->length); 1049 1050 target = skb_put(chunk->skb, len); 1051 1052 if (data) 1053 memcpy(target, data, len); 1054 else 1055 memset(target, 0, len); 1056 1057 /* Adjust the chunk length field. */ 1058 chunk->chunk_hdr->length = htons(chunklen + len); 1059 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1060 1061 return target; 1062 } 1063 1064 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ 1065 struct sctp_chunk *sctp_make_abort_violation( 1066 const struct sctp_association *asoc, 1067 const struct sctp_chunk *chunk, 1068 const __u8 *payload, 1069 const size_t paylen) 1070 { 1071 struct sctp_chunk *retval; 1072 struct sctp_paramhdr phdr; 1073 1074 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen 1075 + sizeof(sctp_paramhdr_t)); 1076 if (!retval) 1077 goto end; 1078 1079 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen 1080 + sizeof(sctp_paramhdr_t)); 1081 1082 phdr.type = htons(chunk->chunk_hdr->type); 1083 phdr.length = chunk->chunk_hdr->length; 1084 sctp_addto_chunk(retval, paylen, payload); 1085 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr); 1086 1087 end: 1088 return retval; 1089 } 1090 1091 struct sctp_chunk *sctp_make_violation_paramlen( 1092 const struct sctp_association *asoc, 1093 const struct sctp_chunk *chunk, 1094 struct sctp_paramhdr *param) 1095 { 1096 struct sctp_chunk *retval; 1097 static const char error[] = "The following parameter had invalid length:"; 1098 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t) + 1099 sizeof(sctp_paramhdr_t); 1100 1101 retval = sctp_make_abort(asoc, chunk, payload_len); 1102 if (!retval) 1103 goto nodata; 1104 1105 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, 1106 sizeof(error) + sizeof(sctp_paramhdr_t)); 1107 sctp_addto_chunk(retval, sizeof(error), error); 1108 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), param); 1109 1110 nodata: 1111 return retval; 1112 } 1113 1114 struct sctp_chunk *sctp_make_violation_max_retrans( 1115 const struct sctp_association *asoc, 1116 const struct sctp_chunk *chunk) 1117 { 1118 struct sctp_chunk *retval; 1119 static const char error[] = "Association exceeded its max_retans count"; 1120 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t); 1121 1122 retval = sctp_make_abort(asoc, chunk, payload_len); 1123 if (!retval) 1124 goto nodata; 1125 1126 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error)); 1127 sctp_addto_chunk(retval, sizeof(error), error); 1128 1129 nodata: 1130 return retval; 1131 } 1132 1133 /* Make a HEARTBEAT chunk. */ 1134 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1135 const struct sctp_transport *transport) 1136 { 1137 struct sctp_chunk *retval; 1138 sctp_sender_hb_info_t hbinfo; 1139 1140 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, sizeof(hbinfo)); 1141 1142 if (!retval) 1143 goto nodata; 1144 1145 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; 1146 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t)); 1147 hbinfo.daddr = transport->ipaddr; 1148 hbinfo.sent_at = jiffies; 1149 hbinfo.hb_nonce = transport->hb_nonce; 1150 1151 /* Cast away the 'const', as this is just telling the chunk 1152 * what transport it belongs to. 1153 */ 1154 retval->transport = (struct sctp_transport *) transport; 1155 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo), 1156 &hbinfo); 1157 1158 nodata: 1159 return retval; 1160 } 1161 1162 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1163 const struct sctp_chunk *chunk, 1164 const void *payload, const size_t paylen) 1165 { 1166 struct sctp_chunk *retval; 1167 1168 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen); 1169 if (!retval) 1170 goto nodata; 1171 1172 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1173 1174 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1175 * 1176 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1177 * HEARTBEAT ACK, * etc.) to the same destination transport 1178 * address from which it * received the DATA or control chunk 1179 * to which it is replying. 1180 * 1181 * [HBACK back to where the HEARTBEAT came from.] 1182 */ 1183 if (chunk) 1184 retval->transport = chunk->transport; 1185 1186 nodata: 1187 return retval; 1188 } 1189 1190 /* Create an Operation Error chunk with the specified space reserved. 1191 * This routine can be used for containing multiple causes in the chunk. 1192 */ 1193 static struct sctp_chunk *sctp_make_op_error_space( 1194 const struct sctp_association *asoc, 1195 const struct sctp_chunk *chunk, 1196 size_t size) 1197 { 1198 struct sctp_chunk *retval; 1199 1200 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0, 1201 sizeof(sctp_errhdr_t) + size); 1202 if (!retval) 1203 goto nodata; 1204 1205 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1206 * 1207 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1208 * HEARTBEAT ACK, etc.) to the same destination transport 1209 * address from which it received the DATA or control chunk 1210 * to which it is replying. 1211 * 1212 */ 1213 if (chunk) 1214 retval->transport = chunk->transport; 1215 1216 nodata: 1217 return retval; 1218 } 1219 1220 /* Create an Operation Error chunk of a fixed size, 1221 * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) 1222 * This is a helper function to allocate an error chunk for 1223 * for those invalid parameter codes in which we may not want 1224 * to report all the errors, if the incoming chunk is large 1225 */ 1226 static inline struct sctp_chunk *sctp_make_op_error_fixed( 1227 const struct sctp_association *asoc, 1228 const struct sctp_chunk *chunk) 1229 { 1230 size_t size = asoc ? asoc->pathmtu : 0; 1231 1232 if (!size) 1233 size = SCTP_DEFAULT_MAXSEGMENT; 1234 1235 return sctp_make_op_error_space(asoc, chunk, size); 1236 } 1237 1238 /* Create an Operation Error chunk. */ 1239 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1240 const struct sctp_chunk *chunk, 1241 __be16 cause_code, const void *payload, 1242 size_t paylen, size_t reserve_tail) 1243 { 1244 struct sctp_chunk *retval; 1245 1246 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); 1247 if (!retval) 1248 goto nodata; 1249 1250 sctp_init_cause(retval, cause_code, paylen + reserve_tail); 1251 sctp_addto_chunk(retval, paylen, payload); 1252 if (reserve_tail) 1253 sctp_addto_param(retval, reserve_tail, NULL); 1254 1255 nodata: 1256 return retval; 1257 } 1258 1259 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc) 1260 { 1261 struct sctp_chunk *retval; 1262 struct sctp_hmac *hmac_desc; 1263 struct sctp_authhdr auth_hdr; 1264 __u8 *hmac; 1265 1266 /* Get the first hmac that the peer told us to use */ 1267 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1268 if (unlikely(!hmac_desc)) 1269 return NULL; 1270 1271 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0, 1272 hmac_desc->hmac_len + sizeof(sctp_authhdr_t)); 1273 if (!retval) 1274 return NULL; 1275 1276 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1277 auth_hdr.shkey_id = htons(asoc->active_key_id); 1278 1279 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t), 1280 &auth_hdr); 1281 1282 hmac = skb_put(retval->skb, hmac_desc->hmac_len); 1283 memset(hmac, 0, hmac_desc->hmac_len); 1284 1285 /* Adjust the chunk header to include the empty MAC */ 1286 retval->chunk_hdr->length = 1287 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1288 retval->chunk_end = skb_tail_pointer(retval->skb); 1289 1290 return retval; 1291 } 1292 1293 1294 /******************************************************************** 1295 * 2nd Level Abstractions 1296 ********************************************************************/ 1297 1298 /* Turn an skb into a chunk. 1299 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1300 * 1301 * sctpimpguide-05.txt Section 2.8.2 1302 * M1) Each time a new DATA chunk is transmitted 1303 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1304 * 'TSN.Missing.Report' count will be used to determine missing chunks 1305 * and when to fast retransmit. 1306 * 1307 */ 1308 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1309 const struct sctp_association *asoc, 1310 struct sock *sk) 1311 { 1312 struct sctp_chunk *retval; 1313 1314 retval = kmem_cache_zalloc(sctp_chunk_cachep, GFP_ATOMIC); 1315 1316 if (!retval) 1317 goto nodata; 1318 if (!sk) 1319 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb); 1320 1321 INIT_LIST_HEAD(&retval->list); 1322 retval->skb = skb; 1323 retval->asoc = (struct sctp_association *)asoc; 1324 retval->singleton = 1; 1325 1326 retval->fast_retransmit = SCTP_CAN_FRTX; 1327 1328 /* Polish the bead hole. */ 1329 INIT_LIST_HEAD(&retval->transmitted_list); 1330 INIT_LIST_HEAD(&retval->frag_list); 1331 SCTP_DBG_OBJCNT_INC(chunk); 1332 atomic_set(&retval->refcnt, 1); 1333 1334 nodata: 1335 return retval; 1336 } 1337 1338 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1339 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1340 union sctp_addr *dest) 1341 { 1342 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1343 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1344 } 1345 1346 /* Extract the source address from a chunk. */ 1347 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1348 { 1349 /* If we have a known transport, use that. */ 1350 if (chunk->transport) { 1351 return &chunk->transport->ipaddr; 1352 } else { 1353 /* Otherwise, extract it from the IP header. */ 1354 return &chunk->source; 1355 } 1356 } 1357 1358 /* Create a new chunk, setting the type and flags headers from the 1359 * arguments, reserving enough space for a 'paylen' byte payload. 1360 */ 1361 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 1362 __u8 type, __u8 flags, int paylen) 1363 { 1364 struct sctp_chunk *retval; 1365 sctp_chunkhdr_t *chunk_hdr; 1366 struct sk_buff *skb; 1367 struct sock *sk; 1368 1369 /* No need to allocate LL here, as this is only a chunk. */ 1370 skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen), 1371 GFP_ATOMIC); 1372 if (!skb) 1373 goto nodata; 1374 1375 /* Make room for the chunk header. */ 1376 chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t)); 1377 chunk_hdr->type = type; 1378 chunk_hdr->flags = flags; 1379 chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t)); 1380 1381 sk = asoc ? asoc->base.sk : NULL; 1382 retval = sctp_chunkify(skb, asoc, sk); 1383 if (!retval) { 1384 kfree_skb(skb); 1385 goto nodata; 1386 } 1387 1388 retval->chunk_hdr = chunk_hdr; 1389 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr); 1390 1391 /* Determine if the chunk needs to be authenticated */ 1392 if (sctp_auth_send_cid(type, asoc)) 1393 retval->auth = 1; 1394 1395 return retval; 1396 nodata: 1397 return NULL; 1398 } 1399 1400 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 1401 __u8 flags, int paylen) 1402 { 1403 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen); 1404 } 1405 1406 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 1407 __u8 type, __u8 flags, int paylen) 1408 { 1409 struct sctp_chunk *chunk = _sctp_make_chunk(asoc, type, flags, paylen); 1410 1411 if (chunk) 1412 sctp_control_set_owner_w(chunk); 1413 1414 return chunk; 1415 } 1416 1417 /* Release the memory occupied by a chunk. */ 1418 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1419 { 1420 BUG_ON(!list_empty(&chunk->list)); 1421 list_del_init(&chunk->transmitted_list); 1422 1423 /* Free the chunk skb data and the SCTP_chunk stub itself. */ 1424 dev_kfree_skb(chunk->skb); 1425 1426 SCTP_DBG_OBJCNT_DEC(chunk); 1427 kmem_cache_free(sctp_chunk_cachep, chunk); 1428 } 1429 1430 /* Possibly, free the chunk. */ 1431 void sctp_chunk_free(struct sctp_chunk *chunk) 1432 { 1433 /* Release our reference on the message tracker. */ 1434 if (chunk->msg) 1435 sctp_datamsg_put(chunk->msg); 1436 1437 sctp_chunk_put(chunk); 1438 } 1439 1440 /* Grab a reference to the chunk. */ 1441 void sctp_chunk_hold(struct sctp_chunk *ch) 1442 { 1443 atomic_inc(&ch->refcnt); 1444 } 1445 1446 /* Release a reference to the chunk. */ 1447 void sctp_chunk_put(struct sctp_chunk *ch) 1448 { 1449 if (atomic_dec_and_test(&ch->refcnt)) 1450 sctp_chunk_destroy(ch); 1451 } 1452 1453 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1454 * enough. 1455 */ 1456 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1457 { 1458 void *target; 1459 void *padding; 1460 int chunklen = ntohs(chunk->chunk_hdr->length); 1461 int padlen = WORD_ROUND(chunklen) - chunklen; 1462 1463 padding = skb_put(chunk->skb, padlen); 1464 target = skb_put(chunk->skb, len); 1465 1466 memset(padding, 0, padlen); 1467 memcpy(target, data, len); 1468 1469 /* Adjust the chunk length field. */ 1470 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1471 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1472 1473 return target; 1474 } 1475 1476 /* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient 1477 * space in the chunk 1478 */ 1479 void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk, 1480 int len, const void *data) 1481 { 1482 if (skb_tailroom(chunk->skb) >= len) 1483 return sctp_addto_chunk(chunk, len, data); 1484 else 1485 return NULL; 1486 } 1487 1488 /* Append bytes from user space to the end of a chunk. Will panic if 1489 * chunk is not big enough. 1490 * Returns a kernel err value. 1491 */ 1492 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len, 1493 struct iovec *data) 1494 { 1495 __u8 *target; 1496 int err = 0; 1497 1498 /* Make room in chunk for data. */ 1499 target = skb_put(chunk->skb, len); 1500 1501 /* Copy data (whole iovec) into chunk */ 1502 if ((err = memcpy_fromiovecend(target, data, off, len))) 1503 goto out; 1504 1505 /* Adjust the chunk length field. */ 1506 chunk->chunk_hdr->length = 1507 htons(ntohs(chunk->chunk_hdr->length) + len); 1508 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1509 1510 out: 1511 return err; 1512 } 1513 1514 /* Helper function to assign a TSN if needed. This assumes that both 1515 * the data_hdr and association have already been assigned. 1516 */ 1517 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1518 { 1519 struct sctp_datamsg *msg; 1520 struct sctp_chunk *lchunk; 1521 struct sctp_stream *stream; 1522 __u16 ssn; 1523 __u16 sid; 1524 1525 if (chunk->has_ssn) 1526 return; 1527 1528 /* All fragments will be on the same stream */ 1529 sid = ntohs(chunk->subh.data_hdr->stream); 1530 stream = &chunk->asoc->ssnmap->out; 1531 1532 /* Now assign the sequence number to the entire message. 1533 * All fragments must have the same stream sequence number. 1534 */ 1535 msg = chunk->msg; 1536 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1537 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1538 ssn = 0; 1539 } else { 1540 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1541 ssn = sctp_ssn_next(stream, sid); 1542 else 1543 ssn = sctp_ssn_peek(stream, sid); 1544 } 1545 1546 lchunk->subh.data_hdr->ssn = htons(ssn); 1547 lchunk->has_ssn = 1; 1548 } 1549 } 1550 1551 /* Helper function to assign a TSN if needed. This assumes that both 1552 * the data_hdr and association have already been assigned. 1553 */ 1554 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1555 { 1556 if (!chunk->has_tsn) { 1557 /* This is the last possible instant to 1558 * assign a TSN. 1559 */ 1560 chunk->subh.data_hdr->tsn = 1561 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1562 chunk->has_tsn = 1; 1563 } 1564 } 1565 1566 /* Create a CLOSED association to use with an incoming packet. */ 1567 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1568 struct sctp_chunk *chunk, 1569 gfp_t gfp) 1570 { 1571 struct sctp_association *asoc; 1572 struct sk_buff *skb; 1573 sctp_scope_t scope; 1574 struct sctp_af *af; 1575 1576 /* Create the bare association. */ 1577 scope = sctp_scope(sctp_source(chunk)); 1578 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1579 if (!asoc) 1580 goto nodata; 1581 asoc->temp = 1; 1582 skb = chunk->skb; 1583 /* Create an entry for the source address of the packet. */ 1584 af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version)); 1585 if (unlikely(!af)) 1586 goto fail; 1587 af->from_skb(&asoc->c.peer_addr, skb, 1); 1588 nodata: 1589 return asoc; 1590 1591 fail: 1592 sctp_association_free(asoc); 1593 return NULL; 1594 } 1595 1596 /* Build a cookie representing asoc. 1597 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1598 */ 1599 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, 1600 const struct sctp_association *asoc, 1601 const struct sctp_chunk *init_chunk, 1602 int *cookie_len, 1603 const __u8 *raw_addrs, int addrs_len) 1604 { 1605 sctp_cookie_param_t *retval; 1606 struct sctp_signed_cookie *cookie; 1607 struct scatterlist sg; 1608 int headersize, bodysize; 1609 1610 /* Header size is static data prior to the actual cookie, including 1611 * any padding. 1612 */ 1613 headersize = sizeof(sctp_paramhdr_t) + 1614 (sizeof(struct sctp_signed_cookie) - 1615 sizeof(struct sctp_cookie)); 1616 bodysize = sizeof(struct sctp_cookie) 1617 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1618 1619 /* Pad out the cookie to a multiple to make the signature 1620 * functions simpler to write. 1621 */ 1622 if (bodysize % SCTP_COOKIE_MULTIPLE) 1623 bodysize += SCTP_COOKIE_MULTIPLE 1624 - (bodysize % SCTP_COOKIE_MULTIPLE); 1625 *cookie_len = headersize + bodysize; 1626 1627 /* Clear this memory since we are sending this data structure 1628 * out on the network. 1629 */ 1630 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1631 if (!retval) 1632 goto nodata; 1633 1634 cookie = (struct sctp_signed_cookie *) retval->body; 1635 1636 /* Set up the parameter header. */ 1637 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1638 retval->p.length = htons(*cookie_len); 1639 1640 /* Copy the cookie part of the association itself. */ 1641 cookie->c = asoc->c; 1642 /* Save the raw address list length in the cookie. */ 1643 cookie->c.raw_addr_list_len = addrs_len; 1644 1645 /* Remember PR-SCTP capability. */ 1646 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1647 1648 /* Save adaptation indication in the cookie. */ 1649 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1650 1651 /* Set an expiration time for the cookie. */ 1652 cookie->c.expiration = ktime_add(asoc->cookie_life, 1653 ktime_get()); 1654 1655 /* Copy the peer's init packet. */ 1656 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr, 1657 ntohs(init_chunk->chunk_hdr->length)); 1658 1659 /* Copy the raw local address list of the association. */ 1660 memcpy((__u8 *)&cookie->c.peer_init[0] + 1661 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1662 1663 if (sctp_sk(ep->base.sk)->hmac) { 1664 struct hash_desc desc; 1665 1666 /* Sign the message. */ 1667 sg_init_one(&sg, &cookie->c, bodysize); 1668 desc.tfm = sctp_sk(ep->base.sk)->hmac; 1669 desc.flags = 0; 1670 1671 if (crypto_hash_setkey(desc.tfm, ep->secret_key, 1672 sizeof(ep->secret_key)) || 1673 crypto_hash_digest(&desc, &sg, bodysize, cookie->signature)) 1674 goto free_cookie; 1675 } 1676 1677 return retval; 1678 1679 free_cookie: 1680 kfree(retval); 1681 nodata: 1682 *cookie_len = 0; 1683 return NULL; 1684 } 1685 1686 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1687 struct sctp_association *sctp_unpack_cookie( 1688 const struct sctp_endpoint *ep, 1689 const struct sctp_association *asoc, 1690 struct sctp_chunk *chunk, gfp_t gfp, 1691 int *error, struct sctp_chunk **errp) 1692 { 1693 struct sctp_association *retval = NULL; 1694 struct sctp_signed_cookie *cookie; 1695 struct sctp_cookie *bear_cookie; 1696 int headersize, bodysize, fixed_size; 1697 __u8 *digest = ep->digest; 1698 struct scatterlist sg; 1699 unsigned int len; 1700 sctp_scope_t scope; 1701 struct sk_buff *skb = chunk->skb; 1702 ktime_t kt; 1703 struct hash_desc desc; 1704 1705 /* Header size is static data prior to the actual cookie, including 1706 * any padding. 1707 */ 1708 headersize = sizeof(sctp_chunkhdr_t) + 1709 (sizeof(struct sctp_signed_cookie) - 1710 sizeof(struct sctp_cookie)); 1711 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1712 fixed_size = headersize + sizeof(struct sctp_cookie); 1713 1714 /* Verify that the chunk looks like it even has a cookie. 1715 * There must be enough room for our cookie and our peer's 1716 * INIT chunk. 1717 */ 1718 len = ntohs(chunk->chunk_hdr->length); 1719 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1720 goto malformed; 1721 1722 /* Verify that the cookie has been padded out. */ 1723 if (bodysize % SCTP_COOKIE_MULTIPLE) 1724 goto malformed; 1725 1726 /* Process the cookie. */ 1727 cookie = chunk->subh.cookie_hdr; 1728 bear_cookie = &cookie->c; 1729 1730 if (!sctp_sk(ep->base.sk)->hmac) 1731 goto no_hmac; 1732 1733 /* Check the signature. */ 1734 sg_init_one(&sg, bear_cookie, bodysize); 1735 desc.tfm = sctp_sk(ep->base.sk)->hmac; 1736 desc.flags = 0; 1737 1738 memset(digest, 0x00, SCTP_SIGNATURE_SIZE); 1739 if (crypto_hash_setkey(desc.tfm, ep->secret_key, 1740 sizeof(ep->secret_key)) || 1741 crypto_hash_digest(&desc, &sg, bodysize, digest)) { 1742 *error = -SCTP_IERROR_NOMEM; 1743 goto fail; 1744 } 1745 1746 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1747 *error = -SCTP_IERROR_BAD_SIG; 1748 goto fail; 1749 } 1750 1751 no_hmac: 1752 /* IG Section 2.35.2: 1753 * 3) Compare the port numbers and the verification tag contained 1754 * within the COOKIE ECHO chunk to the actual port numbers and the 1755 * verification tag within the SCTP common header of the received 1756 * packet. If these values do not match the packet MUST be silently 1757 * discarded, 1758 */ 1759 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1760 *error = -SCTP_IERROR_BAD_TAG; 1761 goto fail; 1762 } 1763 1764 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1765 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1766 *error = -SCTP_IERROR_BAD_PORTS; 1767 goto fail; 1768 } 1769 1770 /* Check to see if the cookie is stale. If there is already 1771 * an association, there is no need to check cookie's expiration 1772 * for init collision case of lost COOKIE ACK. 1773 * If skb has been timestamped, then use the stamp, otherwise 1774 * use current time. This introduces a small possibility that 1775 * that a cookie may be considered expired, but his would only slow 1776 * down the new association establishment instead of every packet. 1777 */ 1778 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1779 kt = skb_get_ktime(skb); 1780 else 1781 kt = ktime_get(); 1782 1783 if (!asoc && ktime_compare(bear_cookie->expiration, kt) < 0) { 1784 /* 1785 * Section 3.3.10.3 Stale Cookie Error (3) 1786 * 1787 * Cause of error 1788 * --------------- 1789 * Stale Cookie Error: Indicates the receipt of a valid State 1790 * Cookie that has expired. 1791 */ 1792 len = ntohs(chunk->chunk_hdr->length); 1793 *errp = sctp_make_op_error_space(asoc, chunk, len); 1794 if (*errp) { 1795 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); 1796 __be32 n = htonl(usecs); 1797 1798 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE, 1799 sizeof(n)); 1800 sctp_addto_chunk(*errp, sizeof(n), &n); 1801 *error = -SCTP_IERROR_STALE_COOKIE; 1802 } else 1803 *error = -SCTP_IERROR_NOMEM; 1804 1805 goto fail; 1806 } 1807 1808 /* Make a new base association. */ 1809 scope = sctp_scope(sctp_source(chunk)); 1810 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1811 if (!retval) { 1812 *error = -SCTP_IERROR_NOMEM; 1813 goto fail; 1814 } 1815 1816 /* Set up our peer's port number. */ 1817 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1818 1819 /* Populate the association from the cookie. */ 1820 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1821 1822 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1823 GFP_ATOMIC) < 0) { 1824 *error = -SCTP_IERROR_NOMEM; 1825 goto fail; 1826 } 1827 1828 /* Also, add the destination address. */ 1829 if (list_empty(&retval->base.bind_addr.address_list)) { 1830 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1831 SCTP_ADDR_SRC, GFP_ATOMIC); 1832 } 1833 1834 retval->next_tsn = retval->c.initial_tsn; 1835 retval->ctsn_ack_point = retval->next_tsn - 1; 1836 retval->addip_serial = retval->c.initial_tsn; 1837 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1838 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1839 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1840 1841 /* The INIT stuff will be done by the side effects. */ 1842 return retval; 1843 1844 fail: 1845 if (retval) 1846 sctp_association_free(retval); 1847 1848 return NULL; 1849 1850 malformed: 1851 /* Yikes! The packet is either corrupt or deliberately 1852 * malformed. 1853 */ 1854 *error = -SCTP_IERROR_MALFORMED; 1855 goto fail; 1856 } 1857 1858 /******************************************************************** 1859 * 3rd Level Abstractions 1860 ********************************************************************/ 1861 1862 struct __sctp_missing { 1863 __be32 num_missing; 1864 __be16 type; 1865 } __packed; 1866 1867 /* 1868 * Report a missing mandatory parameter. 1869 */ 1870 static int sctp_process_missing_param(const struct sctp_association *asoc, 1871 sctp_param_t paramtype, 1872 struct sctp_chunk *chunk, 1873 struct sctp_chunk **errp) 1874 { 1875 struct __sctp_missing report; 1876 __u16 len; 1877 1878 len = WORD_ROUND(sizeof(report)); 1879 1880 /* Make an ERROR chunk, preparing enough room for 1881 * returning multiple unknown parameters. 1882 */ 1883 if (!*errp) 1884 *errp = sctp_make_op_error_space(asoc, chunk, len); 1885 1886 if (*errp) { 1887 report.num_missing = htonl(1); 1888 report.type = paramtype; 1889 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1890 sizeof(report)); 1891 sctp_addto_chunk(*errp, sizeof(report), &report); 1892 } 1893 1894 /* Stop processing this chunk. */ 1895 return 0; 1896 } 1897 1898 /* Report an Invalid Mandatory Parameter. */ 1899 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1900 struct sctp_chunk *chunk, 1901 struct sctp_chunk **errp) 1902 { 1903 /* Invalid Mandatory Parameter Error has no payload. */ 1904 1905 if (!*errp) 1906 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1907 1908 if (*errp) 1909 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1910 1911 /* Stop processing this chunk. */ 1912 return 0; 1913 } 1914 1915 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1916 struct sctp_paramhdr *param, 1917 const struct sctp_chunk *chunk, 1918 struct sctp_chunk **errp) 1919 { 1920 /* This is a fatal error. Any accumulated non-fatal errors are 1921 * not reported. 1922 */ 1923 if (*errp) 1924 sctp_chunk_free(*errp); 1925 1926 /* Create an error chunk and fill it in with our payload. */ 1927 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1928 1929 return 0; 1930 } 1931 1932 1933 /* Do not attempt to handle the HOST_NAME parm. However, do 1934 * send back an indicator to the peer. 1935 */ 1936 static int sctp_process_hn_param(const struct sctp_association *asoc, 1937 union sctp_params param, 1938 struct sctp_chunk *chunk, 1939 struct sctp_chunk **errp) 1940 { 1941 __u16 len = ntohs(param.p->length); 1942 1943 /* Processing of the HOST_NAME parameter will generate an 1944 * ABORT. If we've accumulated any non-fatal errors, they 1945 * would be unrecognized parameters and we should not include 1946 * them in the ABORT. 1947 */ 1948 if (*errp) 1949 sctp_chunk_free(*errp); 1950 1951 *errp = sctp_make_op_error_space(asoc, chunk, len); 1952 1953 if (*errp) { 1954 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len); 1955 sctp_addto_chunk(*errp, len, param.v); 1956 } 1957 1958 /* Stop processing this chunk. */ 1959 return 0; 1960 } 1961 1962 static int sctp_verify_ext_param(struct net *net, union sctp_params param) 1963 { 1964 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 1965 int have_auth = 0; 1966 int have_asconf = 0; 1967 int i; 1968 1969 for (i = 0; i < num_ext; i++) { 1970 switch (param.ext->chunks[i]) { 1971 case SCTP_CID_AUTH: 1972 have_auth = 1; 1973 break; 1974 case SCTP_CID_ASCONF: 1975 case SCTP_CID_ASCONF_ACK: 1976 have_asconf = 1; 1977 break; 1978 } 1979 } 1980 1981 /* ADD-IP Security: The draft requires us to ABORT or ignore the 1982 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 1983 * only if ADD-IP is turned on and we are not backward-compatible 1984 * mode. 1985 */ 1986 if (net->sctp.addip_noauth) 1987 return 1; 1988 1989 if (net->sctp.addip_enable && !have_auth && have_asconf) 1990 return 0; 1991 1992 return 1; 1993 } 1994 1995 static void sctp_process_ext_param(struct sctp_association *asoc, 1996 union sctp_params param) 1997 { 1998 struct net *net = sock_net(asoc->base.sk); 1999 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2000 int i; 2001 2002 for (i = 0; i < num_ext; i++) { 2003 switch (param.ext->chunks[i]) { 2004 case SCTP_CID_FWD_TSN: 2005 if (net->sctp.prsctp_enable && 2006 !asoc->peer.prsctp_capable) 2007 asoc->peer.prsctp_capable = 1; 2008 break; 2009 case SCTP_CID_AUTH: 2010 /* if the peer reports AUTH, assume that he 2011 * supports AUTH. 2012 */ 2013 if (net->sctp.auth_enable) 2014 asoc->peer.auth_capable = 1; 2015 break; 2016 case SCTP_CID_ASCONF: 2017 case SCTP_CID_ASCONF_ACK: 2018 if (net->sctp.addip_enable) 2019 asoc->peer.asconf_capable = 1; 2020 break; 2021 default: 2022 break; 2023 } 2024 } 2025 } 2026 2027 /* RFC 3.2.1 & the Implementers Guide 2.2. 2028 * 2029 * The Parameter Types are encoded such that the 2030 * highest-order two bits specify the action that must be 2031 * taken if the processing endpoint does not recognize the 2032 * Parameter Type. 2033 * 2034 * 00 - Stop processing this parameter; do not process any further 2035 * parameters within this chunk 2036 * 2037 * 01 - Stop processing this parameter, do not process any further 2038 * parameters within this chunk, and report the unrecognized 2039 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2040 * 2041 * 10 - Skip this parameter and continue processing. 2042 * 2043 * 11 - Skip this parameter and continue processing but 2044 * report the unrecognized parameter in an 2045 * 'Unrecognized Parameter' ERROR chunk. 2046 * 2047 * Return value: 2048 * SCTP_IERROR_NO_ERROR - continue with the chunk 2049 * SCTP_IERROR_ERROR - stop and report an error. 2050 * SCTP_IERROR_NOMEME - out of memory. 2051 */ 2052 static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc, 2053 union sctp_params param, 2054 struct sctp_chunk *chunk, 2055 struct sctp_chunk **errp) 2056 { 2057 int retval = SCTP_IERROR_NO_ERROR; 2058 2059 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2060 case SCTP_PARAM_ACTION_DISCARD: 2061 retval = SCTP_IERROR_ERROR; 2062 break; 2063 case SCTP_PARAM_ACTION_SKIP: 2064 break; 2065 case SCTP_PARAM_ACTION_DISCARD_ERR: 2066 retval = SCTP_IERROR_ERROR; 2067 /* Fall through */ 2068 case SCTP_PARAM_ACTION_SKIP_ERR: 2069 /* Make an ERROR chunk, preparing enough room for 2070 * returning multiple unknown parameters. 2071 */ 2072 if (NULL == *errp) 2073 *errp = sctp_make_op_error_fixed(asoc, chunk); 2074 2075 if (*errp) { 2076 if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2077 WORD_ROUND(ntohs(param.p->length)))) 2078 sctp_addto_chunk_fixed(*errp, 2079 WORD_ROUND(ntohs(param.p->length)), 2080 param.v); 2081 } else { 2082 /* If there is no memory for generating the ERROR 2083 * report as specified, an ABORT will be triggered 2084 * to the peer and the association won't be 2085 * established. 2086 */ 2087 retval = SCTP_IERROR_NOMEM; 2088 } 2089 break; 2090 default: 2091 break; 2092 } 2093 2094 return retval; 2095 } 2096 2097 /* Verify variable length parameters 2098 * Return values: 2099 * SCTP_IERROR_ABORT - trigger an ABORT 2100 * SCTP_IERROR_NOMEM - out of memory (abort) 2101 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2102 * SCTP_IERROR_NO_ERROR - continue with the chunk 2103 */ 2104 static sctp_ierror_t sctp_verify_param(struct net *net, 2105 const struct sctp_association *asoc, 2106 union sctp_params param, 2107 sctp_cid_t cid, 2108 struct sctp_chunk *chunk, 2109 struct sctp_chunk **err_chunk) 2110 { 2111 struct sctp_hmac_algo_param *hmacs; 2112 int retval = SCTP_IERROR_NO_ERROR; 2113 __u16 n_elt, id = 0; 2114 int i; 2115 2116 /* FIXME - This routine is not looking at each parameter per the 2117 * chunk type, i.e., unrecognized parameters should be further 2118 * identified based on the chunk id. 2119 */ 2120 2121 switch (param.p->type) { 2122 case SCTP_PARAM_IPV4_ADDRESS: 2123 case SCTP_PARAM_IPV6_ADDRESS: 2124 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2125 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2126 case SCTP_PARAM_STATE_COOKIE: 2127 case SCTP_PARAM_HEARTBEAT_INFO: 2128 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2129 case SCTP_PARAM_ECN_CAPABLE: 2130 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2131 break; 2132 2133 case SCTP_PARAM_SUPPORTED_EXT: 2134 if (!sctp_verify_ext_param(net, param)) 2135 return SCTP_IERROR_ABORT; 2136 break; 2137 2138 case SCTP_PARAM_SET_PRIMARY: 2139 if (net->sctp.addip_enable) 2140 break; 2141 goto fallthrough; 2142 2143 case SCTP_PARAM_HOST_NAME_ADDRESS: 2144 /* Tell the peer, we won't support this param. */ 2145 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2146 retval = SCTP_IERROR_ABORT; 2147 break; 2148 2149 case SCTP_PARAM_FWD_TSN_SUPPORT: 2150 if (net->sctp.prsctp_enable) 2151 break; 2152 goto fallthrough; 2153 2154 case SCTP_PARAM_RANDOM: 2155 if (!net->sctp.auth_enable) 2156 goto fallthrough; 2157 2158 /* SCTP-AUTH: Secion 6.1 2159 * If the random number is not 32 byte long the association 2160 * MUST be aborted. The ABORT chunk SHOULD contain the error 2161 * cause 'Protocol Violation'. 2162 */ 2163 if (SCTP_AUTH_RANDOM_LENGTH != 2164 ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) { 2165 sctp_process_inv_paramlength(asoc, param.p, 2166 chunk, err_chunk); 2167 retval = SCTP_IERROR_ABORT; 2168 } 2169 break; 2170 2171 case SCTP_PARAM_CHUNKS: 2172 if (!net->sctp.auth_enable) 2173 goto fallthrough; 2174 2175 /* SCTP-AUTH: Section 3.2 2176 * The CHUNKS parameter MUST be included once in the INIT or 2177 * INIT-ACK chunk if the sender wants to receive authenticated 2178 * chunks. Its maximum length is 260 bytes. 2179 */ 2180 if (260 < ntohs(param.p->length)) { 2181 sctp_process_inv_paramlength(asoc, param.p, 2182 chunk, err_chunk); 2183 retval = SCTP_IERROR_ABORT; 2184 } 2185 break; 2186 2187 case SCTP_PARAM_HMAC_ALGO: 2188 if (!net->sctp.auth_enable) 2189 goto fallthrough; 2190 2191 hmacs = (struct sctp_hmac_algo_param *)param.p; 2192 n_elt = (ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) >> 1; 2193 2194 /* SCTP-AUTH: Section 6.1 2195 * The HMAC algorithm based on SHA-1 MUST be supported and 2196 * included in the HMAC-ALGO parameter. 2197 */ 2198 for (i = 0; i < n_elt; i++) { 2199 id = ntohs(hmacs->hmac_ids[i]); 2200 2201 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2202 break; 2203 } 2204 2205 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2206 sctp_process_inv_paramlength(asoc, param.p, chunk, 2207 err_chunk); 2208 retval = SCTP_IERROR_ABORT; 2209 } 2210 break; 2211 fallthrough: 2212 default: 2213 pr_debug("%s: unrecognized param:%d for chunk:%d\n", 2214 __func__, ntohs(param.p->type), cid); 2215 2216 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2217 break; 2218 } 2219 return retval; 2220 } 2221 2222 /* Verify the INIT packet before we process it. */ 2223 int sctp_verify_init(struct net *net, const struct sctp_association *asoc, 2224 sctp_cid_t cid, 2225 sctp_init_chunk_t *peer_init, 2226 struct sctp_chunk *chunk, 2227 struct sctp_chunk **errp) 2228 { 2229 union sctp_params param; 2230 bool has_cookie = false; 2231 int result; 2232 2233 /* Check for missing mandatory parameters. Note: Initial TSN is 2234 * also mandatory, but is not checked here since the valid range 2235 * is 0..2**32-1. RFC4960, section 3.3.3. 2236 */ 2237 if (peer_init->init_hdr.num_outbound_streams == 0 || 2238 peer_init->init_hdr.num_inbound_streams == 0 || 2239 peer_init->init_hdr.init_tag == 0 || 2240 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) 2241 return sctp_process_inv_mandatory(asoc, chunk, errp); 2242 2243 sctp_walk_params(param, peer_init, init_hdr.params) { 2244 if (param.p->type == SCTP_PARAM_STATE_COOKIE) 2245 has_cookie = true; 2246 } 2247 2248 /* There is a possibility that a parameter length was bad and 2249 * in that case we would have stoped walking the parameters. 2250 * The current param.p would point at the bad one. 2251 * Current consensus on the mailing list is to generate a PROTOCOL 2252 * VIOLATION error. We build the ERROR chunk here and let the normal 2253 * error handling code build and send the packet. 2254 */ 2255 if (param.v != (void*)chunk->chunk_end) 2256 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2257 2258 /* The only missing mandatory param possible today is 2259 * the state cookie for an INIT-ACK chunk. 2260 */ 2261 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2262 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2263 chunk, errp); 2264 2265 /* Verify all the variable length parameters */ 2266 sctp_walk_params(param, peer_init, init_hdr.params) { 2267 2268 result = sctp_verify_param(net, asoc, param, cid, chunk, errp); 2269 switch (result) { 2270 case SCTP_IERROR_ABORT: 2271 case SCTP_IERROR_NOMEM: 2272 return 0; 2273 case SCTP_IERROR_ERROR: 2274 return 1; 2275 case SCTP_IERROR_NO_ERROR: 2276 default: 2277 break; 2278 } 2279 2280 } /* for (loop through all parameters) */ 2281 2282 return 1; 2283 } 2284 2285 /* Unpack the parameters in an INIT packet into an association. 2286 * Returns 0 on failure, else success. 2287 * FIXME: This is an association method. 2288 */ 2289 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2290 const union sctp_addr *peer_addr, 2291 sctp_init_chunk_t *peer_init, gfp_t gfp) 2292 { 2293 struct net *net = sock_net(asoc->base.sk); 2294 union sctp_params param; 2295 struct sctp_transport *transport; 2296 struct list_head *pos, *temp; 2297 struct sctp_af *af; 2298 union sctp_addr addr; 2299 char *cookie; 2300 int src_match = 0; 2301 2302 /* We must include the address that the INIT packet came from. 2303 * This is the only address that matters for an INIT packet. 2304 * When processing a COOKIE ECHO, we retrieve the from address 2305 * of the INIT from the cookie. 2306 */ 2307 2308 /* This implementation defaults to making the first transport 2309 * added as the primary transport. The source address seems to 2310 * be a a better choice than any of the embedded addresses. 2311 */ 2312 if(!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2313 goto nomem; 2314 2315 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2316 src_match = 1; 2317 2318 /* Process the initialization parameters. */ 2319 sctp_walk_params(param, peer_init, init_hdr.params) { 2320 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2321 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2322 af = sctp_get_af_specific(param_type2af(param.p->type)); 2323 af->from_addr_param(&addr, param.addr, 2324 chunk->sctp_hdr->source, 0); 2325 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2326 src_match = 1; 2327 } 2328 2329 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2330 goto clean_up; 2331 } 2332 2333 /* source address of chunk may not match any valid address */ 2334 if (!src_match) 2335 goto clean_up; 2336 2337 /* AUTH: After processing the parameters, make sure that we 2338 * have all the required info to potentially do authentications. 2339 */ 2340 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2341 !asoc->peer.peer_hmacs)) 2342 asoc->peer.auth_capable = 0; 2343 2344 /* In a non-backward compatible mode, if the peer claims 2345 * support for ADD-IP but not AUTH, the ADD-IP spec states 2346 * that we MUST ABORT the association. Section 6. The section 2347 * also give us an option to silently ignore the packet, which 2348 * is what we'll do here. 2349 */ 2350 if (!net->sctp.addip_noauth && 2351 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2352 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2353 SCTP_PARAM_DEL_IP | 2354 SCTP_PARAM_SET_PRIMARY); 2355 asoc->peer.asconf_capable = 0; 2356 goto clean_up; 2357 } 2358 2359 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2360 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2361 transport = list_entry(pos, struct sctp_transport, transports); 2362 if (transport->state == SCTP_UNKNOWN) { 2363 sctp_assoc_rm_peer(asoc, transport); 2364 } 2365 } 2366 2367 /* The fixed INIT headers are always in network byte 2368 * order. 2369 */ 2370 asoc->peer.i.init_tag = 2371 ntohl(peer_init->init_hdr.init_tag); 2372 asoc->peer.i.a_rwnd = 2373 ntohl(peer_init->init_hdr.a_rwnd); 2374 asoc->peer.i.num_outbound_streams = 2375 ntohs(peer_init->init_hdr.num_outbound_streams); 2376 asoc->peer.i.num_inbound_streams = 2377 ntohs(peer_init->init_hdr.num_inbound_streams); 2378 asoc->peer.i.initial_tsn = 2379 ntohl(peer_init->init_hdr.initial_tsn); 2380 2381 /* Apply the upper bounds for output streams based on peer's 2382 * number of inbound streams. 2383 */ 2384 if (asoc->c.sinit_num_ostreams > 2385 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2386 asoc->c.sinit_num_ostreams = 2387 ntohs(peer_init->init_hdr.num_inbound_streams); 2388 } 2389 2390 if (asoc->c.sinit_max_instreams > 2391 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2392 asoc->c.sinit_max_instreams = 2393 ntohs(peer_init->init_hdr.num_outbound_streams); 2394 } 2395 2396 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2397 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2398 2399 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2400 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2401 2402 /* Copy cookie in case we need to resend COOKIE-ECHO. */ 2403 cookie = asoc->peer.cookie; 2404 if (cookie) { 2405 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp); 2406 if (!asoc->peer.cookie) 2407 goto clean_up; 2408 } 2409 2410 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2411 * high (for example, implementations MAY use the size of the receiver 2412 * advertised window). 2413 */ 2414 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2415 transports) { 2416 transport->ssthresh = asoc->peer.i.a_rwnd; 2417 } 2418 2419 /* Set up the TSN tracking pieces. */ 2420 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2421 asoc->peer.i.initial_tsn, gfp)) 2422 goto clean_up; 2423 2424 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2425 * 2426 * The stream sequence number in all the streams shall start 2427 * from 0 when the association is established. Also, when the 2428 * stream sequence number reaches the value 65535 the next 2429 * stream sequence number shall be set to 0. 2430 */ 2431 2432 /* Allocate storage for the negotiated streams if it is not a temporary 2433 * association. 2434 */ 2435 if (!asoc->temp) { 2436 int error; 2437 2438 asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams, 2439 asoc->c.sinit_num_ostreams, gfp); 2440 if (!asoc->ssnmap) 2441 goto clean_up; 2442 2443 error = sctp_assoc_set_id(asoc, gfp); 2444 if (error) 2445 goto clean_up; 2446 } 2447 2448 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2449 * 2450 * When an endpoint has an ASCONF signaled change to be sent to the 2451 * remote endpoint it should do the following: 2452 * ... 2453 * A2) A serial number should be assigned to the Chunk. The serial 2454 * number should be a monotonically increasing number. All serial 2455 * numbers are defined to be initialized at the start of the 2456 * association to the same value as the Initial TSN. 2457 */ 2458 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2459 return 1; 2460 2461 clean_up: 2462 /* Release the transport structures. */ 2463 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2464 transport = list_entry(pos, struct sctp_transport, transports); 2465 if (transport->state != SCTP_ACTIVE) 2466 sctp_assoc_rm_peer(asoc, transport); 2467 } 2468 2469 nomem: 2470 return 0; 2471 } 2472 2473 2474 /* Update asoc with the option described in param. 2475 * 2476 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2477 * 2478 * asoc is the association to update. 2479 * param is the variable length parameter to use for update. 2480 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2481 * If the current packet is an INIT we want to minimize the amount of 2482 * work we do. In particular, we should not build transport 2483 * structures for the addresses. 2484 */ 2485 static int sctp_process_param(struct sctp_association *asoc, 2486 union sctp_params param, 2487 const union sctp_addr *peer_addr, 2488 gfp_t gfp) 2489 { 2490 struct net *net = sock_net(asoc->base.sk); 2491 union sctp_addr addr; 2492 int i; 2493 __u16 sat; 2494 int retval = 1; 2495 sctp_scope_t scope; 2496 time_t stale; 2497 struct sctp_af *af; 2498 union sctp_addr_param *addr_param; 2499 struct sctp_transport *t; 2500 2501 /* We maintain all INIT parameters in network byte order all the 2502 * time. This allows us to not worry about whether the parameters 2503 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2504 */ 2505 switch (param.p->type) { 2506 case SCTP_PARAM_IPV6_ADDRESS: 2507 if (PF_INET6 != asoc->base.sk->sk_family) 2508 break; 2509 goto do_addr_param; 2510 2511 case SCTP_PARAM_IPV4_ADDRESS: 2512 /* v4 addresses are not allowed on v6-only socket */ 2513 if (ipv6_only_sock(asoc->base.sk)) 2514 break; 2515 do_addr_param: 2516 af = sctp_get_af_specific(param_type2af(param.p->type)); 2517 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); 2518 scope = sctp_scope(peer_addr); 2519 if (sctp_in_scope(net, &addr, scope)) 2520 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2521 return 0; 2522 break; 2523 2524 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2525 if (!net->sctp.cookie_preserve_enable) 2526 break; 2527 2528 stale = ntohl(param.life->lifespan_increment); 2529 2530 /* Suggested Cookie Life span increment's unit is msec, 2531 * (1/1000sec). 2532 */ 2533 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale); 2534 break; 2535 2536 case SCTP_PARAM_HOST_NAME_ADDRESS: 2537 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__); 2538 break; 2539 2540 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2541 /* Turn off the default values first so we'll know which 2542 * ones are really set by the peer. 2543 */ 2544 asoc->peer.ipv4_address = 0; 2545 asoc->peer.ipv6_address = 0; 2546 2547 /* Assume that peer supports the address family 2548 * by which it sends a packet. 2549 */ 2550 if (peer_addr->sa.sa_family == AF_INET6) 2551 asoc->peer.ipv6_address = 1; 2552 else if (peer_addr->sa.sa_family == AF_INET) 2553 asoc->peer.ipv4_address = 1; 2554 2555 /* Cycle through address types; avoid divide by 0. */ 2556 sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2557 if (sat) 2558 sat /= sizeof(__u16); 2559 2560 for (i = 0; i < sat; ++i) { 2561 switch (param.sat->types[i]) { 2562 case SCTP_PARAM_IPV4_ADDRESS: 2563 asoc->peer.ipv4_address = 1; 2564 break; 2565 2566 case SCTP_PARAM_IPV6_ADDRESS: 2567 if (PF_INET6 == asoc->base.sk->sk_family) 2568 asoc->peer.ipv6_address = 1; 2569 break; 2570 2571 case SCTP_PARAM_HOST_NAME_ADDRESS: 2572 asoc->peer.hostname_address = 1; 2573 break; 2574 2575 default: /* Just ignore anything else. */ 2576 break; 2577 } 2578 } 2579 break; 2580 2581 case SCTP_PARAM_STATE_COOKIE: 2582 asoc->peer.cookie_len = 2583 ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2584 asoc->peer.cookie = param.cookie->body; 2585 break; 2586 2587 case SCTP_PARAM_HEARTBEAT_INFO: 2588 /* Would be odd to receive, but it causes no problems. */ 2589 break; 2590 2591 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2592 /* Rejected during verify stage. */ 2593 break; 2594 2595 case SCTP_PARAM_ECN_CAPABLE: 2596 asoc->peer.ecn_capable = 1; 2597 break; 2598 2599 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2600 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2601 break; 2602 2603 case SCTP_PARAM_SET_PRIMARY: 2604 if (!net->sctp.addip_enable) 2605 goto fall_through; 2606 2607 addr_param = param.v + sizeof(sctp_addip_param_t); 2608 2609 af = sctp_get_af_specific(param_type2af(param.p->type)); 2610 af->from_addr_param(&addr, addr_param, 2611 htons(asoc->peer.port), 0); 2612 2613 /* if the address is invalid, we can't process it. 2614 * XXX: see spec for what to do. 2615 */ 2616 if (!af->addr_valid(&addr, NULL, NULL)) 2617 break; 2618 2619 t = sctp_assoc_lookup_paddr(asoc, &addr); 2620 if (!t) 2621 break; 2622 2623 sctp_assoc_set_primary(asoc, t); 2624 break; 2625 2626 case SCTP_PARAM_SUPPORTED_EXT: 2627 sctp_process_ext_param(asoc, param); 2628 break; 2629 2630 case SCTP_PARAM_FWD_TSN_SUPPORT: 2631 if (net->sctp.prsctp_enable) { 2632 asoc->peer.prsctp_capable = 1; 2633 break; 2634 } 2635 /* Fall Through */ 2636 goto fall_through; 2637 2638 case SCTP_PARAM_RANDOM: 2639 if (!net->sctp.auth_enable) 2640 goto fall_through; 2641 2642 /* Save peer's random parameter */ 2643 asoc->peer.peer_random = kmemdup(param.p, 2644 ntohs(param.p->length), gfp); 2645 if (!asoc->peer.peer_random) { 2646 retval = 0; 2647 break; 2648 } 2649 break; 2650 2651 case SCTP_PARAM_HMAC_ALGO: 2652 if (!net->sctp.auth_enable) 2653 goto fall_through; 2654 2655 /* Save peer's HMAC list */ 2656 asoc->peer.peer_hmacs = kmemdup(param.p, 2657 ntohs(param.p->length), gfp); 2658 if (!asoc->peer.peer_hmacs) { 2659 retval = 0; 2660 break; 2661 } 2662 2663 /* Set the default HMAC the peer requested*/ 2664 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2665 break; 2666 2667 case SCTP_PARAM_CHUNKS: 2668 if (!net->sctp.auth_enable) 2669 goto fall_through; 2670 2671 asoc->peer.peer_chunks = kmemdup(param.p, 2672 ntohs(param.p->length), gfp); 2673 if (!asoc->peer.peer_chunks) 2674 retval = 0; 2675 break; 2676 fall_through: 2677 default: 2678 /* Any unrecognized parameters should have been caught 2679 * and handled by sctp_verify_param() which should be 2680 * called prior to this routine. Simply log the error 2681 * here. 2682 */ 2683 pr_debug("%s: ignoring param:%d for association:%p.\n", 2684 __func__, ntohs(param.p->type), asoc); 2685 break; 2686 } 2687 2688 return retval; 2689 } 2690 2691 /* Select a new verification tag. */ 2692 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2693 { 2694 /* I believe that this random number generator complies with RFC1750. 2695 * A tag of 0 is reserved for special cases (e.g. INIT). 2696 */ 2697 __u32 x; 2698 2699 do { 2700 get_random_bytes(&x, sizeof(__u32)); 2701 } while (x == 0); 2702 2703 return x; 2704 } 2705 2706 /* Select an initial TSN to send during startup. */ 2707 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2708 { 2709 __u32 retval; 2710 2711 get_random_bytes(&retval, sizeof(__u32)); 2712 return retval; 2713 } 2714 2715 /* 2716 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2717 * 0 1 2 3 2718 * 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 2719 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2720 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2721 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2722 * | Serial Number | 2723 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2724 * | Address Parameter | 2725 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2726 * | ASCONF Parameter #1 | 2727 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2728 * \ \ 2729 * / .... / 2730 * \ \ 2731 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2732 * | ASCONF Parameter #N | 2733 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2734 * 2735 * Address Parameter and other parameter will not be wrapped in this function 2736 */ 2737 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2738 union sctp_addr *addr, 2739 int vparam_len) 2740 { 2741 sctp_addiphdr_t asconf; 2742 struct sctp_chunk *retval; 2743 int length = sizeof(asconf) + vparam_len; 2744 union sctp_addr_param addrparam; 2745 int addrlen; 2746 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2747 2748 addrlen = af->to_addr_param(addr, &addrparam); 2749 if (!addrlen) 2750 return NULL; 2751 length += addrlen; 2752 2753 /* Create the chunk. */ 2754 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length); 2755 if (!retval) 2756 return NULL; 2757 2758 asconf.serial = htonl(asoc->addip_serial++); 2759 2760 retval->subh.addip_hdr = 2761 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2762 retval->param_hdr.v = 2763 sctp_addto_chunk(retval, addrlen, &addrparam); 2764 2765 return retval; 2766 } 2767 2768 /* ADDIP 2769 * 3.2.1 Add IP Address 2770 * 0 1 2 3 2771 * 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 2772 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2773 * | Type = 0xC001 | Length = Variable | 2774 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2775 * | ASCONF-Request Correlation ID | 2776 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2777 * | Address Parameter | 2778 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2779 * 2780 * 3.2.2 Delete IP Address 2781 * 0 1 2 3 2782 * 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 2783 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2784 * | Type = 0xC002 | Length = Variable | 2785 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2786 * | ASCONF-Request Correlation ID | 2787 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2788 * | Address Parameter | 2789 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2790 * 2791 */ 2792 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2793 union sctp_addr *laddr, 2794 struct sockaddr *addrs, 2795 int addrcnt, 2796 __be16 flags) 2797 { 2798 sctp_addip_param_t param; 2799 struct sctp_chunk *retval; 2800 union sctp_addr_param addr_param; 2801 union sctp_addr *addr; 2802 void *addr_buf; 2803 struct sctp_af *af; 2804 int paramlen = sizeof(param); 2805 int addr_param_len = 0; 2806 int totallen = 0; 2807 int i; 2808 int del_pickup = 0; 2809 2810 /* Get total length of all the address parameters. */ 2811 addr_buf = addrs; 2812 for (i = 0; i < addrcnt; i++) { 2813 addr = addr_buf; 2814 af = sctp_get_af_specific(addr->v4.sin_family); 2815 addr_param_len = af->to_addr_param(addr, &addr_param); 2816 2817 totallen += paramlen; 2818 totallen += addr_param_len; 2819 2820 addr_buf += af->sockaddr_len; 2821 if (asoc->asconf_addr_del_pending && !del_pickup) { 2822 /* reuse the parameter length from the same scope one */ 2823 totallen += paramlen; 2824 totallen += addr_param_len; 2825 del_pickup = 1; 2826 2827 pr_debug("%s: picked same-scope del_pending addr, " 2828 "totallen for all addresses is %d\n", 2829 __func__, totallen); 2830 } 2831 } 2832 2833 /* Create an asconf chunk with the required length. */ 2834 retval = sctp_make_asconf(asoc, laddr, totallen); 2835 if (!retval) 2836 return NULL; 2837 2838 /* Add the address parameters to the asconf chunk. */ 2839 addr_buf = addrs; 2840 for (i = 0; i < addrcnt; i++) { 2841 addr = addr_buf; 2842 af = sctp_get_af_specific(addr->v4.sin_family); 2843 addr_param_len = af->to_addr_param(addr, &addr_param); 2844 param.param_hdr.type = flags; 2845 param.param_hdr.length = htons(paramlen + addr_param_len); 2846 param.crr_id = i; 2847 2848 sctp_addto_chunk(retval, paramlen, ¶m); 2849 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2850 2851 addr_buf += af->sockaddr_len; 2852 } 2853 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2854 addr = asoc->asconf_addr_del_pending; 2855 af = sctp_get_af_specific(addr->v4.sin_family); 2856 addr_param_len = af->to_addr_param(addr, &addr_param); 2857 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2858 param.param_hdr.length = htons(paramlen + addr_param_len); 2859 param.crr_id = i; 2860 2861 sctp_addto_chunk(retval, paramlen, ¶m); 2862 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2863 } 2864 return retval; 2865 } 2866 2867 /* ADDIP 2868 * 3.2.4 Set Primary IP Address 2869 * 0 1 2 3 2870 * 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 2871 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2872 * | Type =0xC004 | Length = Variable | 2873 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2874 * | ASCONF-Request Correlation ID | 2875 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2876 * | Address Parameter | 2877 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2878 * 2879 * Create an ASCONF chunk with Set Primary IP address parameter. 2880 */ 2881 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2882 union sctp_addr *addr) 2883 { 2884 sctp_addip_param_t param; 2885 struct sctp_chunk *retval; 2886 int len = sizeof(param); 2887 union sctp_addr_param addrparam; 2888 int addrlen; 2889 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2890 2891 addrlen = af->to_addr_param(addr, &addrparam); 2892 if (!addrlen) 2893 return NULL; 2894 len += addrlen; 2895 2896 /* Create the chunk and make asconf header. */ 2897 retval = sctp_make_asconf(asoc, addr, len); 2898 if (!retval) 2899 return NULL; 2900 2901 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2902 param.param_hdr.length = htons(len); 2903 param.crr_id = 0; 2904 2905 sctp_addto_chunk(retval, sizeof(param), ¶m); 2906 sctp_addto_chunk(retval, addrlen, &addrparam); 2907 2908 return retval; 2909 } 2910 2911 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2912 * 0 1 2 3 2913 * 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 2914 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2915 * | Type = 0x80 | Chunk Flags | Chunk Length | 2916 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2917 * | Serial Number | 2918 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2919 * | ASCONF Parameter Response#1 | 2920 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2921 * \ \ 2922 * / .... / 2923 * \ \ 2924 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2925 * | ASCONF Parameter Response#N | 2926 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2927 * 2928 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2929 */ 2930 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2931 __u32 serial, int vparam_len) 2932 { 2933 sctp_addiphdr_t asconf; 2934 struct sctp_chunk *retval; 2935 int length = sizeof(asconf) + vparam_len; 2936 2937 /* Create the chunk. */ 2938 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length); 2939 if (!retval) 2940 return NULL; 2941 2942 asconf.serial = htonl(serial); 2943 2944 retval->subh.addip_hdr = 2945 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2946 2947 return retval; 2948 } 2949 2950 /* Add response parameters to an ASCONF_ACK chunk. */ 2951 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2952 __be16 err_code, sctp_addip_param_t *asconf_param) 2953 { 2954 sctp_addip_param_t ack_param; 2955 sctp_errhdr_t err_param; 2956 int asconf_param_len = 0; 2957 int err_param_len = 0; 2958 __be16 response_type; 2959 2960 if (SCTP_ERROR_NO_ERROR == err_code) { 2961 response_type = SCTP_PARAM_SUCCESS_REPORT; 2962 } else { 2963 response_type = SCTP_PARAM_ERR_CAUSE; 2964 err_param_len = sizeof(err_param); 2965 if (asconf_param) 2966 asconf_param_len = 2967 ntohs(asconf_param->param_hdr.length); 2968 } 2969 2970 /* Add Success Indication or Error Cause Indication parameter. */ 2971 ack_param.param_hdr.type = response_type; 2972 ack_param.param_hdr.length = htons(sizeof(ack_param) + 2973 err_param_len + 2974 asconf_param_len); 2975 ack_param.crr_id = crr_id; 2976 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 2977 2978 if (SCTP_ERROR_NO_ERROR == err_code) 2979 return; 2980 2981 /* Add Error Cause parameter. */ 2982 err_param.cause = err_code; 2983 err_param.length = htons(err_param_len + asconf_param_len); 2984 sctp_addto_chunk(chunk, err_param_len, &err_param); 2985 2986 /* Add the failed TLV copied from ASCONF chunk. */ 2987 if (asconf_param) 2988 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 2989 } 2990 2991 /* Process a asconf parameter. */ 2992 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 2993 struct sctp_chunk *asconf, 2994 sctp_addip_param_t *asconf_param) 2995 { 2996 struct sctp_transport *peer; 2997 struct sctp_af *af; 2998 union sctp_addr addr; 2999 union sctp_addr_param *addr_param; 3000 3001 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t); 3002 3003 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 3004 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 3005 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 3006 return SCTP_ERROR_UNKNOWN_PARAM; 3007 3008 switch (addr_param->p.type) { 3009 case SCTP_PARAM_IPV6_ADDRESS: 3010 if (!asoc->peer.ipv6_address) 3011 return SCTP_ERROR_DNS_FAILED; 3012 break; 3013 case SCTP_PARAM_IPV4_ADDRESS: 3014 if (!asoc->peer.ipv4_address) 3015 return SCTP_ERROR_DNS_FAILED; 3016 break; 3017 default: 3018 return SCTP_ERROR_DNS_FAILED; 3019 } 3020 3021 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3022 if (unlikely(!af)) 3023 return SCTP_ERROR_DNS_FAILED; 3024 3025 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); 3026 3027 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3028 * or multicast address. 3029 * (note: wildcard is permitted and requires special handling so 3030 * make sure we check for that) 3031 */ 3032 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3033 return SCTP_ERROR_DNS_FAILED; 3034 3035 switch (asconf_param->param_hdr.type) { 3036 case SCTP_PARAM_ADD_IP: 3037 /* Section 4.2.1: 3038 * If the address 0.0.0.0 or ::0 is provided, the source 3039 * address of the packet MUST be added. 3040 */ 3041 if (af->is_any(&addr)) 3042 memcpy(&addr, &asconf->source, sizeof(addr)); 3043 3044 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3045 * request and does not have the local resources to add this 3046 * new address to the association, it MUST return an Error 3047 * Cause TLV set to the new error code 'Operation Refused 3048 * Due to Resource Shortage'. 3049 */ 3050 3051 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3052 if (!peer) 3053 return SCTP_ERROR_RSRC_LOW; 3054 3055 /* Start the heartbeat timer. */ 3056 if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer))) 3057 sctp_transport_hold(peer); 3058 asoc->new_transport = peer; 3059 break; 3060 case SCTP_PARAM_DEL_IP: 3061 /* ADDIP 4.3 D7) If a request is received to delete the 3062 * last remaining IP address of a peer endpoint, the receiver 3063 * MUST send an Error Cause TLV with the error cause set to the 3064 * new error code 'Request to Delete Last Remaining IP Address'. 3065 */ 3066 if (asoc->peer.transport_count == 1) 3067 return SCTP_ERROR_DEL_LAST_IP; 3068 3069 /* ADDIP 4.3 D8) If a request is received to delete an IP 3070 * address which is also the source address of the IP packet 3071 * which contained the ASCONF chunk, the receiver MUST reject 3072 * this request. To reject the request the receiver MUST send 3073 * an Error Cause TLV set to the new error code 'Request to 3074 * Delete Source IP Address' 3075 */ 3076 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3077 return SCTP_ERROR_DEL_SRC_IP; 3078 3079 /* Section 4.2.2 3080 * If the address 0.0.0.0 or ::0 is provided, all 3081 * addresses of the peer except the source address of the 3082 * packet MUST be deleted. 3083 */ 3084 if (af->is_any(&addr)) { 3085 sctp_assoc_set_primary(asoc, asconf->transport); 3086 sctp_assoc_del_nonprimary_peers(asoc, 3087 asconf->transport); 3088 } else 3089 sctp_assoc_del_peer(asoc, &addr); 3090 break; 3091 case SCTP_PARAM_SET_PRIMARY: 3092 /* ADDIP Section 4.2.4 3093 * If the address 0.0.0.0 or ::0 is provided, the receiver 3094 * MAY mark the source address of the packet as its 3095 * primary. 3096 */ 3097 if (af->is_any(&addr)) 3098 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr)); 3099 3100 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3101 if (!peer) 3102 return SCTP_ERROR_DNS_FAILED; 3103 3104 sctp_assoc_set_primary(asoc, peer); 3105 break; 3106 } 3107 3108 return SCTP_ERROR_NO_ERROR; 3109 } 3110 3111 /* Verify the ASCONF packet before we process it. */ 3112 int sctp_verify_asconf(const struct sctp_association *asoc, 3113 struct sctp_paramhdr *param_hdr, void *chunk_end, 3114 struct sctp_paramhdr **errp) { 3115 sctp_addip_param_t *asconf_param; 3116 union sctp_params param; 3117 int length, plen; 3118 3119 param.v = (sctp_paramhdr_t *) param_hdr; 3120 while (param.v <= chunk_end - sizeof(sctp_paramhdr_t)) { 3121 length = ntohs(param.p->length); 3122 *errp = param.p; 3123 3124 if (param.v > chunk_end - length || 3125 length < sizeof(sctp_paramhdr_t)) 3126 return 0; 3127 3128 switch (param.p->type) { 3129 case SCTP_PARAM_ADD_IP: 3130 case SCTP_PARAM_DEL_IP: 3131 case SCTP_PARAM_SET_PRIMARY: 3132 asconf_param = (sctp_addip_param_t *)param.v; 3133 plen = ntohs(asconf_param->param_hdr.length); 3134 if (plen < sizeof(sctp_addip_param_t) + 3135 sizeof(sctp_paramhdr_t)) 3136 return 0; 3137 break; 3138 case SCTP_PARAM_SUCCESS_REPORT: 3139 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3140 if (length != sizeof(sctp_addip_param_t)) 3141 return 0; 3142 3143 break; 3144 default: 3145 break; 3146 } 3147 3148 param.v += WORD_ROUND(length); 3149 } 3150 3151 if (param.v != chunk_end) 3152 return 0; 3153 3154 return 1; 3155 } 3156 3157 /* Process an incoming ASCONF chunk with the next expected serial no. and 3158 * return an ASCONF_ACK chunk to be sent in response. 3159 */ 3160 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3161 struct sctp_chunk *asconf) 3162 { 3163 sctp_addiphdr_t *hdr; 3164 union sctp_addr_param *addr_param; 3165 sctp_addip_param_t *asconf_param; 3166 struct sctp_chunk *asconf_ack; 3167 3168 __be16 err_code; 3169 int length = 0; 3170 int chunk_len; 3171 __u32 serial; 3172 int all_param_pass = 1; 3173 3174 chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t); 3175 hdr = (sctp_addiphdr_t *)asconf->skb->data; 3176 serial = ntohl(hdr->serial); 3177 3178 /* Skip the addiphdr and store a pointer to address parameter. */ 3179 length = sizeof(sctp_addiphdr_t); 3180 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3181 chunk_len -= length; 3182 3183 /* Skip the address parameter and store a pointer to the first 3184 * asconf parameter. 3185 */ 3186 length = ntohs(addr_param->p.length); 3187 asconf_param = (void *)addr_param + length; 3188 chunk_len -= length; 3189 3190 /* create an ASCONF_ACK chunk. 3191 * Based on the definitions of parameters, we know that the size of 3192 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3193 * parameters. 3194 */ 3195 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3196 if (!asconf_ack) 3197 goto done; 3198 3199 /* Process the TLVs contained within the ASCONF chunk. */ 3200 while (chunk_len > 0) { 3201 err_code = sctp_process_asconf_param(asoc, asconf, 3202 asconf_param); 3203 /* ADDIP 4.1 A7) 3204 * If an error response is received for a TLV parameter, 3205 * all TLVs with no response before the failed TLV are 3206 * considered successful if not reported. All TLVs after 3207 * the failed response are considered unsuccessful unless 3208 * a specific success indication is present for the parameter. 3209 */ 3210 if (SCTP_ERROR_NO_ERROR != err_code) 3211 all_param_pass = 0; 3212 3213 if (!all_param_pass) 3214 sctp_add_asconf_response(asconf_ack, 3215 asconf_param->crr_id, err_code, 3216 asconf_param); 3217 3218 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3219 * an IP address sends an 'Out of Resource' in its response, it 3220 * MUST also fail any subsequent add or delete requests bundled 3221 * in the ASCONF. 3222 */ 3223 if (SCTP_ERROR_RSRC_LOW == err_code) 3224 goto done; 3225 3226 /* Move to the next ASCONF param. */ 3227 length = ntohs(asconf_param->param_hdr.length); 3228 asconf_param = (void *)asconf_param + length; 3229 chunk_len -= length; 3230 } 3231 3232 done: 3233 asoc->peer.addip_serial++; 3234 3235 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3236 * after freeing the reference to old asconf ack if any. 3237 */ 3238 if (asconf_ack) { 3239 sctp_chunk_hold(asconf_ack); 3240 list_add_tail(&asconf_ack->transmitted_list, 3241 &asoc->asconf_ack_list); 3242 } 3243 3244 return asconf_ack; 3245 } 3246 3247 /* Process a asconf parameter that is successfully acked. */ 3248 static void sctp_asconf_param_success(struct sctp_association *asoc, 3249 sctp_addip_param_t *asconf_param) 3250 { 3251 struct sctp_af *af; 3252 union sctp_addr addr; 3253 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3254 union sctp_addr_param *addr_param; 3255 struct sctp_transport *transport; 3256 struct sctp_sockaddr_entry *saddr; 3257 3258 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t); 3259 3260 /* We have checked the packet before, so we do not check again. */ 3261 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3262 af->from_addr_param(&addr, addr_param, htons(bp->port), 0); 3263 3264 switch (asconf_param->param_hdr.type) { 3265 case SCTP_PARAM_ADD_IP: 3266 /* This is always done in BH context with a socket lock 3267 * held, so the list can not change. 3268 */ 3269 local_bh_disable(); 3270 list_for_each_entry(saddr, &bp->address_list, list) { 3271 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3272 saddr->state = SCTP_ADDR_SRC; 3273 } 3274 local_bh_enable(); 3275 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3276 transports) { 3277 dst_release(transport->dst); 3278 transport->dst = NULL; 3279 } 3280 break; 3281 case SCTP_PARAM_DEL_IP: 3282 local_bh_disable(); 3283 sctp_del_bind_addr(bp, &addr); 3284 if (asoc->asconf_addr_del_pending != NULL && 3285 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3286 kfree(asoc->asconf_addr_del_pending); 3287 asoc->asconf_addr_del_pending = NULL; 3288 } 3289 local_bh_enable(); 3290 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3291 transports) { 3292 dst_release(transport->dst); 3293 transport->dst = NULL; 3294 } 3295 break; 3296 default: 3297 break; 3298 } 3299 } 3300 3301 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3302 * for the given asconf parameter. If there is no response for this parameter, 3303 * return the error code based on the third argument 'no_err'. 3304 * ADDIP 4.1 3305 * A7) If an error response is received for a TLV parameter, all TLVs with no 3306 * response before the failed TLV are considered successful if not reported. 3307 * All TLVs after the failed response are considered unsuccessful unless a 3308 * specific success indication is present for the parameter. 3309 */ 3310 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3311 sctp_addip_param_t *asconf_param, 3312 int no_err) 3313 { 3314 sctp_addip_param_t *asconf_ack_param; 3315 sctp_errhdr_t *err_param; 3316 int length; 3317 int asconf_ack_len; 3318 __be16 err_code; 3319 3320 if (no_err) 3321 err_code = SCTP_ERROR_NO_ERROR; 3322 else 3323 err_code = SCTP_ERROR_REQ_REFUSED; 3324 3325 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3326 sizeof(sctp_chunkhdr_t); 3327 3328 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3329 * the first asconf_ack parameter. 3330 */ 3331 length = sizeof(sctp_addiphdr_t); 3332 asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data + 3333 length); 3334 asconf_ack_len -= length; 3335 3336 while (asconf_ack_len > 0) { 3337 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3338 switch(asconf_ack_param->param_hdr.type) { 3339 case SCTP_PARAM_SUCCESS_REPORT: 3340 return SCTP_ERROR_NO_ERROR; 3341 case SCTP_PARAM_ERR_CAUSE: 3342 length = sizeof(sctp_addip_param_t); 3343 err_param = (void *)asconf_ack_param + length; 3344 asconf_ack_len -= length; 3345 if (asconf_ack_len > 0) 3346 return err_param->cause; 3347 else 3348 return SCTP_ERROR_INV_PARAM; 3349 break; 3350 default: 3351 return SCTP_ERROR_INV_PARAM; 3352 } 3353 } 3354 3355 length = ntohs(asconf_ack_param->param_hdr.length); 3356 asconf_ack_param = (void *)asconf_ack_param + length; 3357 asconf_ack_len -= length; 3358 } 3359 3360 return err_code; 3361 } 3362 3363 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3364 int sctp_process_asconf_ack(struct sctp_association *asoc, 3365 struct sctp_chunk *asconf_ack) 3366 { 3367 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3368 union sctp_addr_param *addr_param; 3369 sctp_addip_param_t *asconf_param; 3370 int length = 0; 3371 int asconf_len = asconf->skb->len; 3372 int all_param_pass = 0; 3373 int no_err = 1; 3374 int retval = 0; 3375 __be16 err_code = SCTP_ERROR_NO_ERROR; 3376 3377 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3378 * a pointer to address parameter. 3379 */ 3380 length = sizeof(sctp_addip_chunk_t); 3381 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3382 asconf_len -= length; 3383 3384 /* Skip the address parameter in the last asconf sent and store a 3385 * pointer to the first asconf parameter. 3386 */ 3387 length = ntohs(addr_param->p.length); 3388 asconf_param = (void *)addr_param + length; 3389 asconf_len -= length; 3390 3391 /* ADDIP 4.1 3392 * A8) If there is no response(s) to specific TLV parameter(s), and no 3393 * failures are indicated, then all request(s) are considered 3394 * successful. 3395 */ 3396 if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t)) 3397 all_param_pass = 1; 3398 3399 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3400 while (asconf_len > 0) { 3401 if (all_param_pass) 3402 err_code = SCTP_ERROR_NO_ERROR; 3403 else { 3404 err_code = sctp_get_asconf_response(asconf_ack, 3405 asconf_param, 3406 no_err); 3407 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3408 no_err = 0; 3409 } 3410 3411 switch (err_code) { 3412 case SCTP_ERROR_NO_ERROR: 3413 sctp_asconf_param_success(asoc, asconf_param); 3414 break; 3415 3416 case SCTP_ERROR_RSRC_LOW: 3417 retval = 1; 3418 break; 3419 3420 case SCTP_ERROR_UNKNOWN_PARAM: 3421 /* Disable sending this type of asconf parameter in 3422 * future. 3423 */ 3424 asoc->peer.addip_disabled_mask |= 3425 asconf_param->param_hdr.type; 3426 break; 3427 3428 case SCTP_ERROR_REQ_REFUSED: 3429 case SCTP_ERROR_DEL_LAST_IP: 3430 case SCTP_ERROR_DEL_SRC_IP: 3431 default: 3432 break; 3433 } 3434 3435 /* Skip the processed asconf parameter and move to the next 3436 * one. 3437 */ 3438 length = ntohs(asconf_param->param_hdr.length); 3439 asconf_param = (void *)asconf_param + length; 3440 asconf_len -= length; 3441 } 3442 3443 if (no_err && asoc->src_out_of_asoc_ok) { 3444 asoc->src_out_of_asoc_ok = 0; 3445 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3446 } 3447 3448 /* Free the cached last sent asconf chunk. */ 3449 list_del_init(&asconf->transmitted_list); 3450 sctp_chunk_free(asconf); 3451 asoc->addip_last_asconf = NULL; 3452 3453 return retval; 3454 } 3455 3456 /* Make a FWD TSN chunk. */ 3457 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3458 __u32 new_cum_tsn, size_t nstreams, 3459 struct sctp_fwdtsn_skip *skiplist) 3460 { 3461 struct sctp_chunk *retval = NULL; 3462 struct sctp_fwdtsn_hdr ftsn_hdr; 3463 struct sctp_fwdtsn_skip skip; 3464 size_t hint; 3465 int i; 3466 3467 hint = (nstreams + 1) * sizeof(__u32); 3468 3469 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint); 3470 3471 if (!retval) 3472 return NULL; 3473 3474 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3475 retval->subh.fwdtsn_hdr = 3476 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3477 3478 for (i = 0; i < nstreams; i++) { 3479 skip.stream = skiplist[i].stream; 3480 skip.ssn = skiplist[i].ssn; 3481 sctp_addto_chunk(retval, sizeof(skip), &skip); 3482 } 3483 3484 return retval; 3485 } 3486