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 <lksctp-developers@lists.sourceforge.net> 33 * 34 * Or submit a bug report through the following website: 35 * http://www.sf.net/projects/lksctp 36 * 37 * Written or modified by: 38 * La Monte H.P. Yarroll <piggy@acm.org> 39 * Karl Knutson <karl@athena.chicago.il.us> 40 * C. Robin <chris@hundredacre.ac.uk> 41 * Jon Grimm <jgrimm@us.ibm.com> 42 * Xingang Guo <xingang.guo@intel.com> 43 * Dajiang Zhang <dajiang.zhang@nokia.com> 44 * Sridhar Samudrala <sri@us.ibm.com> 45 * Daisy Chang <daisyc@us.ibm.com> 46 * Ardelle Fan <ardelle.fan@intel.com> 47 * Kevin Gao <kevin.gao@intel.com> 48 * 49 * Any bugs reported given to us we will try to fix... any fixes shared will 50 * be incorporated into the next SCTP release. 51 */ 52 53 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 54 55 #include <linux/types.h> 56 #include <linux/kernel.h> 57 #include <linux/ip.h> 58 #include <linux/ipv6.h> 59 #include <linux/net.h> 60 #include <linux/inet.h> 61 #include <linux/scatterlist.h> 62 #include <linux/crypto.h> 63 #include <linux/slab.h> 64 #include <net/sock.h> 65 66 #include <linux/skbuff.h> 67 #include <linux/random.h> /* for get_random_bytes */ 68 #include <net/sctp/sctp.h> 69 #include <net/sctp/sm.h> 70 71 SCTP_STATIC 72 struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc, 73 __u8 type, __u8 flags, int paylen); 74 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, 75 const struct sctp_association *asoc, 76 const struct sctp_chunk *init_chunk, 77 int *cookie_len, 78 const __u8 *raw_addrs, int addrs_len); 79 static int sctp_process_param(struct sctp_association *asoc, 80 union sctp_params param, 81 const union sctp_addr *peer_addr, 82 gfp_t gfp); 83 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 84 const void *data); 85 86 /* What was the inbound interface for this chunk? */ 87 int sctp_chunk_iif(const struct sctp_chunk *chunk) 88 { 89 struct sctp_af *af; 90 int iif = 0; 91 92 af = sctp_get_af_specific(ipver2af(ip_hdr(chunk->skb)->version)); 93 if (af) 94 iif = af->skb_iif(chunk->skb); 95 96 return iif; 97 } 98 99 /* RFC 2960 3.3.2 Initiation (INIT) (1) 100 * 101 * Note 2: The ECN capable field is reserved for future use of 102 * Explicit Congestion Notification. 103 */ 104 static const struct sctp_paramhdr ecap_param = { 105 SCTP_PARAM_ECN_CAPABLE, 106 cpu_to_be16(sizeof(struct sctp_paramhdr)), 107 }; 108 static const struct sctp_paramhdr prsctp_param = { 109 SCTP_PARAM_FWD_TSN_SUPPORT, 110 cpu_to_be16(sizeof(struct sctp_paramhdr)), 111 }; 112 113 /* A helper to initialize an op error inside a 114 * provided chunk, as most cause codes will be embedded inside an 115 * abort chunk. 116 */ 117 void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, 118 size_t paylen) 119 { 120 sctp_errhdr_t err; 121 __u16 len; 122 123 /* Cause code constants are now defined in network order. */ 124 err.cause = cause_code; 125 len = sizeof(sctp_errhdr_t) + paylen; 126 err.length = htons(len); 127 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err); 128 } 129 130 /* A helper to initialize an op error inside a 131 * provided chunk, as most cause codes will be embedded inside an 132 * abort chunk. Differs from sctp_init_cause in that it won't oops 133 * if there isn't enough space in the op error chunk 134 */ 135 static int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code, 136 size_t paylen) 137 { 138 sctp_errhdr_t err; 139 __u16 len; 140 141 /* Cause code constants are now defined in network order. */ 142 err.cause = cause_code; 143 len = sizeof(sctp_errhdr_t) + paylen; 144 err.length = htons(len); 145 146 if (skb_tailroom(chunk->skb) < len) 147 return -ENOSPC; 148 chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk, 149 sizeof(sctp_errhdr_t), 150 &err); 151 return 0; 152 } 153 /* 3.3.2 Initiation (INIT) (1) 154 * 155 * This chunk is used to initiate a SCTP association between two 156 * endpoints. The format of the INIT chunk is shown below: 157 * 158 * 0 1 2 3 159 * 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 1 160 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 161 * | Type = 1 | Chunk Flags | Chunk Length | 162 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 163 * | Initiate Tag | 164 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 165 * | Advertised Receiver Window Credit (a_rwnd) | 166 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 167 * | Number of Outbound Streams | Number of Inbound Streams | 168 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 169 * | Initial TSN | 170 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 171 * \ \ 172 * / Optional/Variable-Length Parameters / 173 * \ \ 174 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 175 * 176 * 177 * The INIT chunk contains the following parameters. Unless otherwise 178 * noted, each parameter MUST only be included once in the INIT chunk. 179 * 180 * Fixed Parameters Status 181 * ---------------------------------------------- 182 * Initiate Tag Mandatory 183 * Advertised Receiver Window Credit Mandatory 184 * Number of Outbound Streams Mandatory 185 * Number of Inbound Streams Mandatory 186 * Initial TSN Mandatory 187 * 188 * Variable Parameters Status Type Value 189 * ------------------------------------------------------------- 190 * IPv4 Address (Note 1) Optional 5 191 * IPv6 Address (Note 1) Optional 6 192 * Cookie Preservative Optional 9 193 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000) 194 * Host Name Address (Note 3) Optional 11 195 * Supported Address Types (Note 4) Optional 12 196 */ 197 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc, 198 const struct sctp_bind_addr *bp, 199 gfp_t gfp, int vparam_len) 200 { 201 struct net *net = sock_net(asoc->base.sk); 202 sctp_inithdr_t init; 203 union sctp_params addrs; 204 size_t chunksize; 205 struct sctp_chunk *retval = NULL; 206 int num_types, addrs_len = 0; 207 struct sctp_sock *sp; 208 sctp_supported_addrs_param_t sat; 209 __be16 types[2]; 210 sctp_adaptation_ind_param_t aiparam; 211 sctp_supported_ext_param_t ext_param; 212 int num_ext = 0; 213 __u8 extensions[3]; 214 sctp_paramhdr_t *auth_chunks = NULL, 215 *auth_hmacs = NULL; 216 217 /* RFC 2960 3.3.2 Initiation (INIT) (1) 218 * 219 * Note 1: The INIT chunks can contain multiple addresses that 220 * can be IPv4 and/or IPv6 in any combination. 221 */ 222 retval = NULL; 223 224 /* Convert the provided bind address list to raw format. */ 225 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp); 226 227 init.init_tag = htonl(asoc->c.my_vtag); 228 init.a_rwnd = htonl(asoc->rwnd); 229 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 230 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 231 init.initial_tsn = htonl(asoc->c.initial_tsn); 232 233 /* How many address types are needed? */ 234 sp = sctp_sk(asoc->base.sk); 235 num_types = sp->pf->supported_addrs(sp, types); 236 237 chunksize = sizeof(init) + addrs_len; 238 chunksize += WORD_ROUND(SCTP_SAT_LEN(num_types)); 239 chunksize += sizeof(ecap_param); 240 241 if (net->sctp.prsctp_enable) 242 chunksize += sizeof(prsctp_param); 243 244 /* ADDIP: Section 4.2.7: 245 * An implementation supporting this extension [ADDIP] MUST list 246 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and 247 * INIT-ACK parameters. 248 */ 249 if (net->sctp.addip_enable) { 250 extensions[num_ext] = SCTP_CID_ASCONF; 251 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 252 num_ext += 2; 253 } 254 255 if (sp->adaptation_ind) 256 chunksize += sizeof(aiparam); 257 258 chunksize += vparam_len; 259 260 /* Account for AUTH related parameters */ 261 if (net->sctp.auth_enable) { 262 /* Add random parameter length*/ 263 chunksize += sizeof(asoc->c.auth_random); 264 265 /* Add HMACS parameter length if any were defined */ 266 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs; 267 if (auth_hmacs->length) 268 chunksize += WORD_ROUND(ntohs(auth_hmacs->length)); 269 else 270 auth_hmacs = NULL; 271 272 /* Add CHUNKS parameter length */ 273 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks; 274 if (auth_chunks->length) 275 chunksize += WORD_ROUND(ntohs(auth_chunks->length)); 276 else 277 auth_chunks = NULL; 278 279 extensions[num_ext] = SCTP_CID_AUTH; 280 num_ext += 1; 281 } 282 283 /* If we have any extensions to report, account for that */ 284 if (num_ext) 285 chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) + 286 num_ext); 287 288 /* RFC 2960 3.3.2 Initiation (INIT) (1) 289 * 290 * Note 3: An INIT chunk MUST NOT contain more than one Host 291 * Name address parameter. Moreover, the sender of the INIT 292 * MUST NOT combine any other address types with the Host Name 293 * address in the INIT. The receiver of INIT MUST ignore any 294 * other address types if the Host Name address parameter is 295 * present in the received INIT chunk. 296 * 297 * PLEASE DO NOT FIXME [This version does not support Host Name.] 298 */ 299 300 retval = sctp_make_chunk(asoc, SCTP_CID_INIT, 0, chunksize); 301 if (!retval) 302 goto nodata; 303 304 retval->subh.init_hdr = 305 sctp_addto_chunk(retval, sizeof(init), &init); 306 retval->param_hdr.v = 307 sctp_addto_chunk(retval, addrs_len, addrs.v); 308 309 /* RFC 2960 3.3.2 Initiation (INIT) (1) 310 * 311 * Note 4: This parameter, when present, specifies all the 312 * address types the sending endpoint can support. The absence 313 * of this parameter indicates that the sending endpoint can 314 * support any address type. 315 */ 316 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES; 317 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types)); 318 sctp_addto_chunk(retval, sizeof(sat), &sat); 319 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types); 320 321 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 322 323 /* Add the supported extensions parameter. Be nice and add this 324 * fist before addiding the parameters for the extensions themselves 325 */ 326 if (num_ext) { 327 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 328 ext_param.param_hdr.length = 329 htons(sizeof(sctp_supported_ext_param_t) + num_ext); 330 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t), 331 &ext_param); 332 sctp_addto_param(retval, num_ext, extensions); 333 } 334 335 if (net->sctp.prsctp_enable) 336 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 337 338 if (sp->adaptation_ind) { 339 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 340 aiparam.param_hdr.length = htons(sizeof(aiparam)); 341 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 342 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 343 } 344 345 /* Add SCTP-AUTH chunks to the parameter list */ 346 if (net->sctp.auth_enable) { 347 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random), 348 asoc->c.auth_random); 349 if (auth_hmacs) 350 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 351 auth_hmacs); 352 if (auth_chunks) 353 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 354 auth_chunks); 355 } 356 nodata: 357 kfree(addrs.v); 358 return retval; 359 } 360 361 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, 362 const struct sctp_chunk *chunk, 363 gfp_t gfp, int unkparam_len) 364 { 365 sctp_inithdr_t initack; 366 struct sctp_chunk *retval; 367 union sctp_params addrs; 368 struct sctp_sock *sp; 369 int addrs_len; 370 sctp_cookie_param_t *cookie; 371 int cookie_len; 372 size_t chunksize; 373 sctp_adaptation_ind_param_t aiparam; 374 sctp_supported_ext_param_t ext_param; 375 int num_ext = 0; 376 __u8 extensions[3]; 377 sctp_paramhdr_t *auth_chunks = NULL, 378 *auth_hmacs = NULL, 379 *auth_random = NULL; 380 381 retval = NULL; 382 383 /* Note: there may be no addresses to embed. */ 384 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp); 385 386 initack.init_tag = htonl(asoc->c.my_vtag); 387 initack.a_rwnd = htonl(asoc->rwnd); 388 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 389 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 390 initack.initial_tsn = htonl(asoc->c.initial_tsn); 391 392 /* FIXME: We really ought to build the cookie right 393 * into the packet instead of allocating more fresh memory. 394 */ 395 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len, 396 addrs.v, addrs_len); 397 if (!cookie) 398 goto nomem_cookie; 399 400 /* Calculate the total size of allocation, include the reserved 401 * space for reporting unknown parameters if it is specified. 402 */ 403 sp = sctp_sk(asoc->base.sk); 404 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len; 405 406 /* Tell peer that we'll do ECN only if peer advertised such cap. */ 407 if (asoc->peer.ecn_capable) 408 chunksize += sizeof(ecap_param); 409 410 if (asoc->peer.prsctp_capable) 411 chunksize += sizeof(prsctp_param); 412 413 if (asoc->peer.asconf_capable) { 414 extensions[num_ext] = SCTP_CID_ASCONF; 415 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 416 num_ext += 2; 417 } 418 419 if (sp->adaptation_ind) 420 chunksize += sizeof(aiparam); 421 422 if (asoc->peer.auth_capable) { 423 auth_random = (sctp_paramhdr_t *)asoc->c.auth_random; 424 chunksize += ntohs(auth_random->length); 425 426 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs; 427 if (auth_hmacs->length) 428 chunksize += WORD_ROUND(ntohs(auth_hmacs->length)); 429 else 430 auth_hmacs = NULL; 431 432 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks; 433 if (auth_chunks->length) 434 chunksize += WORD_ROUND(ntohs(auth_chunks->length)); 435 else 436 auth_chunks = NULL; 437 438 extensions[num_ext] = SCTP_CID_AUTH; 439 num_ext += 1; 440 } 441 442 if (num_ext) 443 chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) + 444 num_ext); 445 446 /* Now allocate and fill out the chunk. */ 447 retval = sctp_make_chunk(asoc, SCTP_CID_INIT_ACK, 0, chunksize); 448 if (!retval) 449 goto nomem_chunk; 450 451 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 452 * 453 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 454 * HEARTBEAT ACK, * etc.) to the same destination transport 455 * address from which it received the DATA or control chunk 456 * to which it is replying. 457 * 458 * [INIT ACK back to where the INIT came from.] 459 */ 460 retval->transport = chunk->transport; 461 462 retval->subh.init_hdr = 463 sctp_addto_chunk(retval, sizeof(initack), &initack); 464 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); 465 sctp_addto_chunk(retval, cookie_len, cookie); 466 if (asoc->peer.ecn_capable) 467 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 468 if (num_ext) { 469 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 470 ext_param.param_hdr.length = 471 htons(sizeof(sctp_supported_ext_param_t) + num_ext); 472 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t), 473 &ext_param); 474 sctp_addto_param(retval, num_ext, extensions); 475 } 476 if (asoc->peer.prsctp_capable) 477 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 478 479 if (sp->adaptation_ind) { 480 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 481 aiparam.param_hdr.length = htons(sizeof(aiparam)); 482 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 483 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 484 } 485 486 if (asoc->peer.auth_capable) { 487 sctp_addto_chunk(retval, ntohs(auth_random->length), 488 auth_random); 489 if (auth_hmacs) 490 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 491 auth_hmacs); 492 if (auth_chunks) 493 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 494 auth_chunks); 495 } 496 497 /* We need to remove the const qualifier at this point. */ 498 retval->asoc = (struct sctp_association *) asoc; 499 500 nomem_chunk: 501 kfree(cookie); 502 nomem_cookie: 503 kfree(addrs.v); 504 return retval; 505 } 506 507 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10): 508 * 509 * This chunk is used only during the initialization of an association. 510 * It is sent by the initiator of an association to its peer to complete 511 * the initialization process. This chunk MUST precede any DATA chunk 512 * sent within the association, but MAY be bundled with one or more DATA 513 * chunks in the same packet. 514 * 515 * 0 1 2 3 516 * 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 1 517 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 518 * | Type = 10 |Chunk Flags | Length | 519 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 520 * / Cookie / 521 * \ \ 522 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 523 * 524 * Chunk Flags: 8 bit 525 * 526 * Set to zero on transmit and ignored on receipt. 527 * 528 * Length: 16 bits (unsigned integer) 529 * 530 * Set to the size of the chunk in bytes, including the 4 bytes of 531 * the chunk header and the size of the Cookie. 532 * 533 * Cookie: variable size 534 * 535 * This field must contain the exact cookie received in the 536 * State Cookie parameter from the previous INIT ACK. 537 * 538 * An implementation SHOULD make the cookie as small as possible 539 * to insure interoperability. 540 */ 541 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, 542 const struct sctp_chunk *chunk) 543 { 544 struct sctp_chunk *retval; 545 void *cookie; 546 int cookie_len; 547 548 cookie = asoc->peer.cookie; 549 cookie_len = asoc->peer.cookie_len; 550 551 /* Build a cookie echo chunk. */ 552 retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ECHO, 0, cookie_len); 553 if (!retval) 554 goto nodata; 555 retval->subh.cookie_hdr = 556 sctp_addto_chunk(retval, cookie_len, cookie); 557 558 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 559 * 560 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 561 * HEARTBEAT ACK, * etc.) to the same destination transport 562 * address from which it * received the DATA or control chunk 563 * to which it is replying. 564 * 565 * [COOKIE ECHO back to where the INIT ACK came from.] 566 */ 567 if (chunk) 568 retval->transport = chunk->transport; 569 570 nodata: 571 return retval; 572 } 573 574 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11): 575 * 576 * This chunk is used only during the initialization of an 577 * association. It is used to acknowledge the receipt of a COOKIE 578 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent 579 * within the association, but MAY be bundled with one or more DATA 580 * chunks or SACK chunk in the same SCTP packet. 581 * 582 * 0 1 2 3 583 * 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 1 584 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 585 * | Type = 11 |Chunk Flags | Length = 4 | 586 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 587 * 588 * Chunk Flags: 8 bits 589 * 590 * Set to zero on transmit and ignored on receipt. 591 */ 592 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, 593 const struct sctp_chunk *chunk) 594 { 595 struct sctp_chunk *retval; 596 597 retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ACK, 0, 0); 598 599 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 600 * 601 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 602 * HEARTBEAT ACK, * etc.) to the same destination transport 603 * address from which it * received the DATA or control chunk 604 * to which it is replying. 605 * 606 * [COOKIE ACK back to where the COOKIE ECHO came from.] 607 */ 608 if (retval && chunk) 609 retval->transport = chunk->transport; 610 611 return retval; 612 } 613 614 /* 615 * Appendix A: Explicit Congestion Notification: 616 * CWR: 617 * 618 * RFC 2481 details a specific bit for a sender to send in the header of 619 * its next outbound TCP segment to indicate to its peer that it has 620 * reduced its congestion window. This is termed the CWR bit. For 621 * SCTP the same indication is made by including the CWR chunk. 622 * This chunk contains one data element, i.e. the TSN number that 623 * was sent in the ECNE chunk. This element represents the lowest 624 * TSN number in the datagram that was originally marked with the 625 * CE bit. 626 * 627 * 0 1 2 3 628 * 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 1 629 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 630 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 | 631 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 632 * | Lowest TSN Number | 633 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 634 * 635 * Note: The CWR is considered a Control chunk. 636 */ 637 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, 638 const __u32 lowest_tsn, 639 const struct sctp_chunk *chunk) 640 { 641 struct sctp_chunk *retval; 642 sctp_cwrhdr_t cwr; 643 644 cwr.lowest_tsn = htonl(lowest_tsn); 645 retval = sctp_make_chunk(asoc, SCTP_CID_ECN_CWR, 0, 646 sizeof(sctp_cwrhdr_t)); 647 648 if (!retval) 649 goto nodata; 650 651 retval->subh.ecn_cwr_hdr = 652 sctp_addto_chunk(retval, sizeof(cwr), &cwr); 653 654 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 655 * 656 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 657 * HEARTBEAT ACK, * etc.) to the same destination transport 658 * address from which it * received the DATA or control chunk 659 * to which it is replying. 660 * 661 * [Report a reduced congestion window back to where the ECNE 662 * came from.] 663 */ 664 if (chunk) 665 retval->transport = chunk->transport; 666 667 nodata: 668 return retval; 669 } 670 671 /* Make an ECNE chunk. This is a congestion experienced report. */ 672 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, 673 const __u32 lowest_tsn) 674 { 675 struct sctp_chunk *retval; 676 sctp_ecnehdr_t ecne; 677 678 ecne.lowest_tsn = htonl(lowest_tsn); 679 retval = sctp_make_chunk(asoc, SCTP_CID_ECN_ECNE, 0, 680 sizeof(sctp_ecnehdr_t)); 681 if (!retval) 682 goto nodata; 683 retval->subh.ecne_hdr = 684 sctp_addto_chunk(retval, sizeof(ecne), &ecne); 685 686 nodata: 687 return retval; 688 } 689 690 /* Make a DATA chunk for the given association from the provided 691 * parameters. However, do not populate the data payload. 692 */ 693 struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc, 694 const struct sctp_sndrcvinfo *sinfo, 695 int data_len, __u8 flags, __u16 ssn) 696 { 697 struct sctp_chunk *retval; 698 struct sctp_datahdr dp; 699 int chunk_len; 700 701 /* We assign the TSN as LATE as possible, not here when 702 * creating the chunk. 703 */ 704 dp.tsn = 0; 705 dp.stream = htons(sinfo->sinfo_stream); 706 dp.ppid = sinfo->sinfo_ppid; 707 708 /* Set the flags for an unordered send. */ 709 if (sinfo->sinfo_flags & SCTP_UNORDERED) { 710 flags |= SCTP_DATA_UNORDERED; 711 dp.ssn = 0; 712 } else 713 dp.ssn = htons(ssn); 714 715 chunk_len = sizeof(dp) + data_len; 716 retval = sctp_make_chunk(asoc, SCTP_CID_DATA, flags, chunk_len); 717 if (!retval) 718 goto nodata; 719 720 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp); 721 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo)); 722 723 nodata: 724 return retval; 725 } 726 727 /* Create a selective ackowledgement (SACK) for the given 728 * association. This reports on which TSN's we've seen to date, 729 * including duplicates and gaps. 730 */ 731 struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc) 732 { 733 struct sctp_chunk *retval; 734 struct sctp_sackhdr sack; 735 int len; 736 __u32 ctsn; 737 __u16 num_gabs, num_dup_tsns; 738 struct sctp_association *aptr = (struct sctp_association *)asoc; 739 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; 740 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; 741 struct sctp_transport *trans; 742 743 memset(gabs, 0, sizeof(gabs)); 744 ctsn = sctp_tsnmap_get_ctsn(map); 745 SCTP_DEBUG_PRINTK("sackCTSNAck sent: 0x%x.\n", ctsn); 746 747 /* How much room is needed in the chunk? */ 748 num_gabs = sctp_tsnmap_num_gabs(map, gabs); 749 num_dup_tsns = sctp_tsnmap_num_dups(map); 750 751 /* Initialize the SACK header. */ 752 sack.cum_tsn_ack = htonl(ctsn); 753 sack.a_rwnd = htonl(asoc->a_rwnd); 754 sack.num_gap_ack_blocks = htons(num_gabs); 755 sack.num_dup_tsns = htons(num_dup_tsns); 756 757 len = sizeof(sack) 758 + sizeof(struct sctp_gap_ack_block) * num_gabs 759 + sizeof(__u32) * num_dup_tsns; 760 761 /* Create the chunk. */ 762 retval = sctp_make_chunk(asoc, SCTP_CID_SACK, 0, len); 763 if (!retval) 764 goto nodata; 765 766 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 767 * 768 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 769 * HEARTBEAT ACK, etc.) to the same destination transport 770 * address from which it received the DATA or control chunk to 771 * which it is replying. This rule should also be followed if 772 * the endpoint is bundling DATA chunks together with the 773 * reply chunk. 774 * 775 * However, when acknowledging multiple DATA chunks received 776 * in packets from different source addresses in a single 777 * SACK, the SACK chunk may be transmitted to one of the 778 * destination transport addresses from which the DATA or 779 * control chunks being acknowledged were received. 780 * 781 * [BUG: We do not implement the following paragraph. 782 * Perhaps we should remember the last transport we used for a 783 * SACK and avoid that (if possible) if we have seen any 784 * duplicates. --piggy] 785 * 786 * When a receiver of a duplicate DATA chunk sends a SACK to a 787 * multi- homed endpoint it MAY be beneficial to vary the 788 * destination address and not use the source address of the 789 * DATA chunk. The reason being that receiving a duplicate 790 * from a multi-homed endpoint might indicate that the return 791 * path (as specified in the source address of the DATA chunk) 792 * for the SACK is broken. 793 * 794 * [Send to the address from which we last received a DATA chunk.] 795 */ 796 retval->transport = asoc->peer.last_data_from; 797 798 retval->subh.sack_hdr = 799 sctp_addto_chunk(retval, sizeof(sack), &sack); 800 801 /* Add the gap ack block information. */ 802 if (num_gabs) 803 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, 804 gabs); 805 806 /* Add the duplicate TSN information. */ 807 if (num_dup_tsns) 808 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, 809 sctp_tsnmap_get_dups(map)); 810 811 /* Once we have a sack generated, check to see what our sack 812 * generation is, if its 0, reset the transports to 0, and reset 813 * the association generation to 1 814 * 815 * The idea is that zero is never used as a valid generation for the 816 * association so no transport will match after a wrap event like this, 817 * Until the next sack 818 */ 819 if (++aptr->peer.sack_generation == 0) { 820 list_for_each_entry(trans, &asoc->peer.transport_addr_list, 821 transports) 822 trans->sack_generation = 0; 823 aptr->peer.sack_generation = 1; 824 } 825 nodata: 826 return retval; 827 } 828 829 /* Make a SHUTDOWN chunk. */ 830 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 831 const struct sctp_chunk *chunk) 832 { 833 struct sctp_chunk *retval; 834 sctp_shutdownhdr_t shut; 835 __u32 ctsn; 836 837 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 838 shut.cum_tsn_ack = htonl(ctsn); 839 840 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN, 0, 841 sizeof(sctp_shutdownhdr_t)); 842 if (!retval) 843 goto nodata; 844 845 retval->subh.shutdown_hdr = 846 sctp_addto_chunk(retval, sizeof(shut), &shut); 847 848 if (chunk) 849 retval->transport = chunk->transport; 850 nodata: 851 return retval; 852 } 853 854 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 855 const struct sctp_chunk *chunk) 856 { 857 struct sctp_chunk *retval; 858 859 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0); 860 861 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 862 * 863 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 864 * HEARTBEAT ACK, * etc.) to the same destination transport 865 * address from which it * received the DATA or control chunk 866 * to which it is replying. 867 * 868 * [ACK back to where the SHUTDOWN came from.] 869 */ 870 if (retval && chunk) 871 retval->transport = chunk->transport; 872 873 return retval; 874 } 875 876 struct sctp_chunk *sctp_make_shutdown_complete( 877 const struct sctp_association *asoc, 878 const struct sctp_chunk *chunk) 879 { 880 struct sctp_chunk *retval; 881 __u8 flags = 0; 882 883 /* Set the T-bit if we have no association (vtag will be 884 * reflected) 885 */ 886 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; 887 888 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0); 889 890 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 891 * 892 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 893 * HEARTBEAT ACK, * etc.) to the same destination transport 894 * address from which it * received the DATA or control chunk 895 * to which it is replying. 896 * 897 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK 898 * came from.] 899 */ 900 if (retval && chunk) 901 retval->transport = chunk->transport; 902 903 return retval; 904 } 905 906 /* Create an ABORT. Note that we set the T bit if we have no 907 * association, except when responding to an INIT (sctpimpguide 2.41). 908 */ 909 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 910 const struct sctp_chunk *chunk, 911 const size_t hint) 912 { 913 struct sctp_chunk *retval; 914 __u8 flags = 0; 915 916 /* Set the T-bit if we have no association and 'chunk' is not 917 * an INIT (vtag will be reflected). 918 */ 919 if (!asoc) { 920 if (chunk && chunk->chunk_hdr && 921 chunk->chunk_hdr->type == SCTP_CID_INIT) 922 flags = 0; 923 else 924 flags = SCTP_CHUNK_FLAG_T; 925 } 926 927 retval = sctp_make_chunk(asoc, SCTP_CID_ABORT, flags, hint); 928 929 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 930 * 931 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 932 * HEARTBEAT ACK, * etc.) to the same destination transport 933 * address from which it * received the DATA or control chunk 934 * to which it is replying. 935 * 936 * [ABORT back to where the offender came from.] 937 */ 938 if (retval && chunk) 939 retval->transport = chunk->transport; 940 941 return retval; 942 } 943 944 /* Helper to create ABORT with a NO_USER_DATA error. */ 945 struct sctp_chunk *sctp_make_abort_no_data( 946 const struct sctp_association *asoc, 947 const struct sctp_chunk *chunk, __u32 tsn) 948 { 949 struct sctp_chunk *retval; 950 __be32 payload; 951 952 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) 953 + sizeof(tsn)); 954 955 if (!retval) 956 goto no_mem; 957 958 /* Put the tsn back into network byte order. */ 959 payload = htonl(tsn); 960 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload)); 961 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload); 962 963 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 964 * 965 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 966 * HEARTBEAT ACK, * etc.) to the same destination transport 967 * address from which it * received the DATA or control chunk 968 * to which it is replying. 969 * 970 * [ABORT back to where the offender came from.] 971 */ 972 if (chunk) 973 retval->transport = chunk->transport; 974 975 no_mem: 976 return retval; 977 } 978 979 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ 980 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 981 const struct msghdr *msg, 982 size_t paylen) 983 { 984 struct sctp_chunk *retval; 985 void *payload = NULL; 986 int err; 987 988 retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen); 989 if (!retval) 990 goto err_chunk; 991 992 if (paylen) { 993 /* Put the msg_iov together into payload. */ 994 payload = kmalloc(paylen, GFP_KERNEL); 995 if (!payload) 996 goto err_payload; 997 998 err = memcpy_fromiovec(payload, msg->msg_iov, paylen); 999 if (err < 0) 1000 goto err_copy; 1001 } 1002 1003 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); 1004 sctp_addto_chunk(retval, paylen, payload); 1005 1006 if (paylen) 1007 kfree(payload); 1008 1009 return retval; 1010 1011 err_copy: 1012 kfree(payload); 1013 err_payload: 1014 sctp_chunk_free(retval); 1015 retval = NULL; 1016 err_chunk: 1017 return retval; 1018 } 1019 1020 /* Append bytes to the end of a parameter. Will panic if chunk is not big 1021 * enough. 1022 */ 1023 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 1024 const void *data) 1025 { 1026 void *target; 1027 int chunklen = ntohs(chunk->chunk_hdr->length); 1028 1029 target = skb_put(chunk->skb, len); 1030 1031 if (data) 1032 memcpy(target, data, len); 1033 else 1034 memset(target, 0, len); 1035 1036 /* Adjust the chunk length field. */ 1037 chunk->chunk_hdr->length = htons(chunklen + len); 1038 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1039 1040 return target; 1041 } 1042 1043 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ 1044 struct sctp_chunk *sctp_make_abort_violation( 1045 const struct sctp_association *asoc, 1046 const struct sctp_chunk *chunk, 1047 const __u8 *payload, 1048 const size_t paylen) 1049 { 1050 struct sctp_chunk *retval; 1051 struct sctp_paramhdr phdr; 1052 1053 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen 1054 + sizeof(sctp_paramhdr_t)); 1055 if (!retval) 1056 goto end; 1057 1058 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen 1059 + sizeof(sctp_paramhdr_t)); 1060 1061 phdr.type = htons(chunk->chunk_hdr->type); 1062 phdr.length = chunk->chunk_hdr->length; 1063 sctp_addto_chunk(retval, paylen, payload); 1064 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr); 1065 1066 end: 1067 return retval; 1068 } 1069 1070 struct sctp_chunk *sctp_make_violation_paramlen( 1071 const struct sctp_association *asoc, 1072 const struct sctp_chunk *chunk, 1073 struct sctp_paramhdr *param) 1074 { 1075 struct sctp_chunk *retval; 1076 static const char error[] = "The following parameter had invalid length:"; 1077 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t) + 1078 sizeof(sctp_paramhdr_t); 1079 1080 retval = sctp_make_abort(asoc, chunk, payload_len); 1081 if (!retval) 1082 goto nodata; 1083 1084 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, 1085 sizeof(error) + sizeof(sctp_paramhdr_t)); 1086 sctp_addto_chunk(retval, sizeof(error), error); 1087 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), param); 1088 1089 nodata: 1090 return retval; 1091 } 1092 1093 /* Make a HEARTBEAT chunk. */ 1094 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1095 const struct sctp_transport *transport) 1096 { 1097 struct sctp_chunk *retval; 1098 sctp_sender_hb_info_t hbinfo; 1099 1100 retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT, 0, sizeof(hbinfo)); 1101 1102 if (!retval) 1103 goto nodata; 1104 1105 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; 1106 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t)); 1107 hbinfo.daddr = transport->ipaddr; 1108 hbinfo.sent_at = jiffies; 1109 hbinfo.hb_nonce = transport->hb_nonce; 1110 1111 /* Cast away the 'const', as this is just telling the chunk 1112 * what transport it belongs to. 1113 */ 1114 retval->transport = (struct sctp_transport *) transport; 1115 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo), 1116 &hbinfo); 1117 1118 nodata: 1119 return retval; 1120 } 1121 1122 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1123 const struct sctp_chunk *chunk, 1124 const void *payload, const size_t paylen) 1125 { 1126 struct sctp_chunk *retval; 1127 1128 retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen); 1129 if (!retval) 1130 goto nodata; 1131 1132 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1133 1134 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1135 * 1136 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1137 * HEARTBEAT ACK, * etc.) to the same destination transport 1138 * address from which it * received the DATA or control chunk 1139 * to which it is replying. 1140 * 1141 * [HBACK back to where the HEARTBEAT came from.] 1142 */ 1143 if (chunk) 1144 retval->transport = chunk->transport; 1145 1146 nodata: 1147 return retval; 1148 } 1149 1150 /* Create an Operation Error chunk with the specified space reserved. 1151 * This routine can be used for containing multiple causes in the chunk. 1152 */ 1153 static struct sctp_chunk *sctp_make_op_error_space( 1154 const struct sctp_association *asoc, 1155 const struct sctp_chunk *chunk, 1156 size_t size) 1157 { 1158 struct sctp_chunk *retval; 1159 1160 retval = sctp_make_chunk(asoc, SCTP_CID_ERROR, 0, 1161 sizeof(sctp_errhdr_t) + size); 1162 if (!retval) 1163 goto nodata; 1164 1165 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1166 * 1167 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1168 * HEARTBEAT ACK, etc.) to the same destination transport 1169 * address from which it received the DATA or control chunk 1170 * to which it is replying. 1171 * 1172 */ 1173 if (chunk) 1174 retval->transport = chunk->transport; 1175 1176 nodata: 1177 return retval; 1178 } 1179 1180 /* Create an Operation Error chunk of a fixed size, 1181 * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) 1182 * This is a helper function to allocate an error chunk for 1183 * for those invalid parameter codes in which we may not want 1184 * to report all the errors, if the incomming chunk is large 1185 */ 1186 static inline struct sctp_chunk *sctp_make_op_error_fixed( 1187 const struct sctp_association *asoc, 1188 const struct sctp_chunk *chunk) 1189 { 1190 size_t size = asoc ? asoc->pathmtu : 0; 1191 1192 if (!size) 1193 size = SCTP_DEFAULT_MAXSEGMENT; 1194 1195 return sctp_make_op_error_space(asoc, chunk, size); 1196 } 1197 1198 /* Create an Operation Error chunk. */ 1199 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1200 const struct sctp_chunk *chunk, 1201 __be16 cause_code, const void *payload, 1202 size_t paylen, size_t reserve_tail) 1203 { 1204 struct sctp_chunk *retval; 1205 1206 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); 1207 if (!retval) 1208 goto nodata; 1209 1210 sctp_init_cause(retval, cause_code, paylen + reserve_tail); 1211 sctp_addto_chunk(retval, paylen, payload); 1212 if (reserve_tail) 1213 sctp_addto_param(retval, reserve_tail, NULL); 1214 1215 nodata: 1216 return retval; 1217 } 1218 1219 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc) 1220 { 1221 struct sctp_chunk *retval; 1222 struct sctp_hmac *hmac_desc; 1223 struct sctp_authhdr auth_hdr; 1224 __u8 *hmac; 1225 1226 /* Get the first hmac that the peer told us to use */ 1227 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1228 if (unlikely(!hmac_desc)) 1229 return NULL; 1230 1231 retval = sctp_make_chunk(asoc, SCTP_CID_AUTH, 0, 1232 hmac_desc->hmac_len + sizeof(sctp_authhdr_t)); 1233 if (!retval) 1234 return NULL; 1235 1236 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1237 auth_hdr.shkey_id = htons(asoc->active_key_id); 1238 1239 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t), 1240 &auth_hdr); 1241 1242 hmac = skb_put(retval->skb, hmac_desc->hmac_len); 1243 memset(hmac, 0, hmac_desc->hmac_len); 1244 1245 /* Adjust the chunk header to include the empty MAC */ 1246 retval->chunk_hdr->length = 1247 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1248 retval->chunk_end = skb_tail_pointer(retval->skb); 1249 1250 return retval; 1251 } 1252 1253 1254 /******************************************************************** 1255 * 2nd Level Abstractions 1256 ********************************************************************/ 1257 1258 /* Turn an skb into a chunk. 1259 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1260 */ 1261 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1262 const struct sctp_association *asoc, 1263 struct sock *sk) 1264 { 1265 struct sctp_chunk *retval; 1266 1267 retval = kmem_cache_zalloc(sctp_chunk_cachep, GFP_ATOMIC); 1268 1269 if (!retval) 1270 goto nodata; 1271 1272 if (!sk) { 1273 SCTP_DEBUG_PRINTK("chunkifying skb %p w/o an sk\n", skb); 1274 } 1275 1276 INIT_LIST_HEAD(&retval->list); 1277 retval->skb = skb; 1278 retval->asoc = (struct sctp_association *)asoc; 1279 retval->has_tsn = 0; 1280 retval->has_ssn = 0; 1281 retval->rtt_in_progress = 0; 1282 retval->sent_at = 0; 1283 retval->singleton = 1; 1284 retval->end_of_packet = 0; 1285 retval->ecn_ce_done = 0; 1286 retval->pdiscard = 0; 1287 1288 /* sctpimpguide-05.txt Section 2.8.2 1289 * M1) Each time a new DATA chunk is transmitted 1290 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1291 * 'TSN.Missing.Report' count will be used to determine missing chunks 1292 * and when to fast retransmit. 1293 */ 1294 retval->tsn_missing_report = 0; 1295 retval->tsn_gap_acked = 0; 1296 retval->fast_retransmit = SCTP_CAN_FRTX; 1297 1298 /* If this is a fragmented message, track all fragments 1299 * of the message (for SEND_FAILED). 1300 */ 1301 retval->msg = NULL; 1302 1303 /* Polish the bead hole. */ 1304 INIT_LIST_HEAD(&retval->transmitted_list); 1305 INIT_LIST_HEAD(&retval->frag_list); 1306 SCTP_DBG_OBJCNT_INC(chunk); 1307 atomic_set(&retval->refcnt, 1); 1308 1309 nodata: 1310 return retval; 1311 } 1312 1313 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1314 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1315 union sctp_addr *dest) 1316 { 1317 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1318 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1319 } 1320 1321 /* Extract the source address from a chunk. */ 1322 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1323 { 1324 /* If we have a known transport, use that. */ 1325 if (chunk->transport) { 1326 return &chunk->transport->ipaddr; 1327 } else { 1328 /* Otherwise, extract it from the IP header. */ 1329 return &chunk->source; 1330 } 1331 } 1332 1333 /* Create a new chunk, setting the type and flags headers from the 1334 * arguments, reserving enough space for a 'paylen' byte payload. 1335 */ 1336 SCTP_STATIC 1337 struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc, 1338 __u8 type, __u8 flags, int paylen) 1339 { 1340 struct sctp_chunk *retval; 1341 sctp_chunkhdr_t *chunk_hdr; 1342 struct sk_buff *skb; 1343 struct sock *sk; 1344 1345 /* No need to allocate LL here, as this is only a chunk. */ 1346 skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen), 1347 GFP_ATOMIC); 1348 if (!skb) 1349 goto nodata; 1350 1351 /* Make room for the chunk header. */ 1352 chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t)); 1353 chunk_hdr->type = type; 1354 chunk_hdr->flags = flags; 1355 chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t)); 1356 1357 sk = asoc ? asoc->base.sk : NULL; 1358 retval = sctp_chunkify(skb, asoc, sk); 1359 if (!retval) { 1360 kfree_skb(skb); 1361 goto nodata; 1362 } 1363 1364 retval->chunk_hdr = chunk_hdr; 1365 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr); 1366 1367 /* Determine if the chunk needs to be authenticated */ 1368 if (sctp_auth_send_cid(type, asoc)) 1369 retval->auth = 1; 1370 1371 /* Set the skb to the belonging sock for accounting. */ 1372 skb->sk = sk; 1373 1374 return retval; 1375 nodata: 1376 return NULL; 1377 } 1378 1379 1380 /* Release the memory occupied by a chunk. */ 1381 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1382 { 1383 BUG_ON(!list_empty(&chunk->list)); 1384 list_del_init(&chunk->transmitted_list); 1385 1386 /* Free the chunk skb data and the SCTP_chunk stub itself. */ 1387 dev_kfree_skb(chunk->skb); 1388 1389 SCTP_DBG_OBJCNT_DEC(chunk); 1390 kmem_cache_free(sctp_chunk_cachep, chunk); 1391 } 1392 1393 /* Possibly, free the chunk. */ 1394 void sctp_chunk_free(struct sctp_chunk *chunk) 1395 { 1396 /* Release our reference on the message tracker. */ 1397 if (chunk->msg) 1398 sctp_datamsg_put(chunk->msg); 1399 1400 sctp_chunk_put(chunk); 1401 } 1402 1403 /* Grab a reference to the chunk. */ 1404 void sctp_chunk_hold(struct sctp_chunk *ch) 1405 { 1406 atomic_inc(&ch->refcnt); 1407 } 1408 1409 /* Release a reference to the chunk. */ 1410 void sctp_chunk_put(struct sctp_chunk *ch) 1411 { 1412 if (atomic_dec_and_test(&ch->refcnt)) 1413 sctp_chunk_destroy(ch); 1414 } 1415 1416 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1417 * enough. 1418 */ 1419 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1420 { 1421 void *target; 1422 void *padding; 1423 int chunklen = ntohs(chunk->chunk_hdr->length); 1424 int padlen = WORD_ROUND(chunklen) - chunklen; 1425 1426 padding = skb_put(chunk->skb, padlen); 1427 target = skb_put(chunk->skb, len); 1428 1429 memset(padding, 0, padlen); 1430 memcpy(target, data, len); 1431 1432 /* Adjust the chunk length field. */ 1433 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1434 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1435 1436 return target; 1437 } 1438 1439 /* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient 1440 * space in the chunk 1441 */ 1442 void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk, 1443 int len, const void *data) 1444 { 1445 if (skb_tailroom(chunk->skb) >= len) 1446 return sctp_addto_chunk(chunk, len, data); 1447 else 1448 return NULL; 1449 } 1450 1451 /* Append bytes from user space to the end of a chunk. Will panic if 1452 * chunk is not big enough. 1453 * Returns a kernel err value. 1454 */ 1455 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len, 1456 struct iovec *data) 1457 { 1458 __u8 *target; 1459 int err = 0; 1460 1461 /* Make room in chunk for data. */ 1462 target = skb_put(chunk->skb, len); 1463 1464 /* Copy data (whole iovec) into chunk */ 1465 if ((err = memcpy_fromiovecend(target, data, off, len))) 1466 goto out; 1467 1468 /* Adjust the chunk length field. */ 1469 chunk->chunk_hdr->length = 1470 htons(ntohs(chunk->chunk_hdr->length) + len); 1471 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1472 1473 out: 1474 return err; 1475 } 1476 1477 /* Helper function to assign a TSN if needed. This assumes that both 1478 * the data_hdr and association have already been assigned. 1479 */ 1480 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1481 { 1482 struct sctp_datamsg *msg; 1483 struct sctp_chunk *lchunk; 1484 struct sctp_stream *stream; 1485 __u16 ssn; 1486 __u16 sid; 1487 1488 if (chunk->has_ssn) 1489 return; 1490 1491 /* All fragments will be on the same stream */ 1492 sid = ntohs(chunk->subh.data_hdr->stream); 1493 stream = &chunk->asoc->ssnmap->out; 1494 1495 /* Now assign the sequence number to the entire message. 1496 * All fragments must have the same stream sequence number. 1497 */ 1498 msg = chunk->msg; 1499 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1500 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1501 ssn = 0; 1502 } else { 1503 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1504 ssn = sctp_ssn_next(stream, sid); 1505 else 1506 ssn = sctp_ssn_peek(stream, sid); 1507 } 1508 1509 lchunk->subh.data_hdr->ssn = htons(ssn); 1510 lchunk->has_ssn = 1; 1511 } 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_tsn(struct sctp_chunk *chunk) 1518 { 1519 if (!chunk->has_tsn) { 1520 /* This is the last possible instant to 1521 * assign a TSN. 1522 */ 1523 chunk->subh.data_hdr->tsn = 1524 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1525 chunk->has_tsn = 1; 1526 } 1527 } 1528 1529 /* Create a CLOSED association to use with an incoming packet. */ 1530 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1531 struct sctp_chunk *chunk, 1532 gfp_t gfp) 1533 { 1534 struct sctp_association *asoc; 1535 struct sk_buff *skb; 1536 sctp_scope_t scope; 1537 struct sctp_af *af; 1538 1539 /* Create the bare association. */ 1540 scope = sctp_scope(sctp_source(chunk)); 1541 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1542 if (!asoc) 1543 goto nodata; 1544 asoc->temp = 1; 1545 skb = chunk->skb; 1546 /* Create an entry for the source address of the packet. */ 1547 af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version)); 1548 if (unlikely(!af)) 1549 goto fail; 1550 af->from_skb(&asoc->c.peer_addr, skb, 1); 1551 nodata: 1552 return asoc; 1553 1554 fail: 1555 sctp_association_free(asoc); 1556 return NULL; 1557 } 1558 1559 /* Build a cookie representing asoc. 1560 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1561 */ 1562 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, 1563 const struct sctp_association *asoc, 1564 const struct sctp_chunk *init_chunk, 1565 int *cookie_len, 1566 const __u8 *raw_addrs, int addrs_len) 1567 { 1568 sctp_cookie_param_t *retval; 1569 struct sctp_signed_cookie *cookie; 1570 struct scatterlist sg; 1571 int headersize, bodysize; 1572 unsigned int keylen; 1573 char *key; 1574 1575 /* Header size is static data prior to the actual cookie, including 1576 * any padding. 1577 */ 1578 headersize = sizeof(sctp_paramhdr_t) + 1579 (sizeof(struct sctp_signed_cookie) - 1580 sizeof(struct sctp_cookie)); 1581 bodysize = sizeof(struct sctp_cookie) 1582 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1583 1584 /* Pad out the cookie to a multiple to make the signature 1585 * functions simpler to write. 1586 */ 1587 if (bodysize % SCTP_COOKIE_MULTIPLE) 1588 bodysize += SCTP_COOKIE_MULTIPLE 1589 - (bodysize % SCTP_COOKIE_MULTIPLE); 1590 *cookie_len = headersize + bodysize; 1591 1592 /* Clear this memory since we are sending this data structure 1593 * out on the network. 1594 */ 1595 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1596 if (!retval) 1597 goto nodata; 1598 1599 cookie = (struct sctp_signed_cookie *) retval->body; 1600 1601 /* Set up the parameter header. */ 1602 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1603 retval->p.length = htons(*cookie_len); 1604 1605 /* Copy the cookie part of the association itself. */ 1606 cookie->c = asoc->c; 1607 /* Save the raw address list length in the cookie. */ 1608 cookie->c.raw_addr_list_len = addrs_len; 1609 1610 /* Remember PR-SCTP capability. */ 1611 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1612 1613 /* Save adaptation indication in the cookie. */ 1614 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1615 1616 /* Set an expiration time for the cookie. */ 1617 do_gettimeofday(&cookie->c.expiration); 1618 TIMEVAL_ADD(asoc->cookie_life, cookie->c.expiration); 1619 1620 /* Copy the peer's init packet. */ 1621 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr, 1622 ntohs(init_chunk->chunk_hdr->length)); 1623 1624 /* Copy the raw local address list of the association. */ 1625 memcpy((__u8 *)&cookie->c.peer_init[0] + 1626 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1627 1628 if (sctp_sk(ep->base.sk)->hmac) { 1629 struct hash_desc desc; 1630 1631 /* Sign the message. */ 1632 sg_init_one(&sg, &cookie->c, bodysize); 1633 keylen = SCTP_SECRET_SIZE; 1634 key = (char *)ep->secret_key[ep->current_key]; 1635 desc.tfm = sctp_sk(ep->base.sk)->hmac; 1636 desc.flags = 0; 1637 1638 if (crypto_hash_setkey(desc.tfm, key, keylen) || 1639 crypto_hash_digest(&desc, &sg, bodysize, cookie->signature)) 1640 goto free_cookie; 1641 } 1642 1643 return retval; 1644 1645 free_cookie: 1646 kfree(retval); 1647 nodata: 1648 *cookie_len = 0; 1649 return NULL; 1650 } 1651 1652 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1653 struct sctp_association *sctp_unpack_cookie( 1654 const struct sctp_endpoint *ep, 1655 const struct sctp_association *asoc, 1656 struct sctp_chunk *chunk, gfp_t gfp, 1657 int *error, struct sctp_chunk **errp) 1658 { 1659 struct sctp_association *retval = NULL; 1660 struct sctp_signed_cookie *cookie; 1661 struct sctp_cookie *bear_cookie; 1662 int headersize, bodysize, fixed_size; 1663 __u8 *digest = ep->digest; 1664 struct scatterlist sg; 1665 unsigned int keylen, len; 1666 char *key; 1667 sctp_scope_t scope; 1668 struct sk_buff *skb = chunk->skb; 1669 struct timeval tv; 1670 struct hash_desc desc; 1671 1672 /* Header size is static data prior to the actual cookie, including 1673 * any padding. 1674 */ 1675 headersize = sizeof(sctp_chunkhdr_t) + 1676 (sizeof(struct sctp_signed_cookie) - 1677 sizeof(struct sctp_cookie)); 1678 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1679 fixed_size = headersize + sizeof(struct sctp_cookie); 1680 1681 /* Verify that the chunk looks like it even has a cookie. 1682 * There must be enough room for our cookie and our peer's 1683 * INIT chunk. 1684 */ 1685 len = ntohs(chunk->chunk_hdr->length); 1686 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1687 goto malformed; 1688 1689 /* Verify that the cookie has been padded out. */ 1690 if (bodysize % SCTP_COOKIE_MULTIPLE) 1691 goto malformed; 1692 1693 /* Process the cookie. */ 1694 cookie = chunk->subh.cookie_hdr; 1695 bear_cookie = &cookie->c; 1696 1697 if (!sctp_sk(ep->base.sk)->hmac) 1698 goto no_hmac; 1699 1700 /* Check the signature. */ 1701 keylen = SCTP_SECRET_SIZE; 1702 sg_init_one(&sg, bear_cookie, bodysize); 1703 key = (char *)ep->secret_key[ep->current_key]; 1704 desc.tfm = sctp_sk(ep->base.sk)->hmac; 1705 desc.flags = 0; 1706 1707 memset(digest, 0x00, SCTP_SIGNATURE_SIZE); 1708 if (crypto_hash_setkey(desc.tfm, key, keylen) || 1709 crypto_hash_digest(&desc, &sg, bodysize, digest)) { 1710 *error = -SCTP_IERROR_NOMEM; 1711 goto fail; 1712 } 1713 1714 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1715 /* Try the previous key. */ 1716 key = (char *)ep->secret_key[ep->last_key]; 1717 memset(digest, 0x00, SCTP_SIGNATURE_SIZE); 1718 if (crypto_hash_setkey(desc.tfm, key, keylen) || 1719 crypto_hash_digest(&desc, &sg, bodysize, digest)) { 1720 *error = -SCTP_IERROR_NOMEM; 1721 goto fail; 1722 } 1723 1724 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1725 /* Yikes! Still bad signature! */ 1726 *error = -SCTP_IERROR_BAD_SIG; 1727 goto fail; 1728 } 1729 } 1730 1731 no_hmac: 1732 /* IG Section 2.35.2: 1733 * 3) Compare the port numbers and the verification tag contained 1734 * within the COOKIE ECHO chunk to the actual port numbers and the 1735 * verification tag within the SCTP common header of the received 1736 * packet. If these values do not match the packet MUST be silently 1737 * discarded, 1738 */ 1739 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1740 *error = -SCTP_IERROR_BAD_TAG; 1741 goto fail; 1742 } 1743 1744 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1745 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1746 *error = -SCTP_IERROR_BAD_PORTS; 1747 goto fail; 1748 } 1749 1750 /* Check to see if the cookie is stale. If there is already 1751 * an association, there is no need to check cookie's expiration 1752 * for init collision case of lost COOKIE ACK. 1753 * If skb has been timestamped, then use the stamp, otherwise 1754 * use current time. This introduces a small possibility that 1755 * that a cookie may be considered expired, but his would only slow 1756 * down the new association establishment instead of every packet. 1757 */ 1758 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1759 skb_get_timestamp(skb, &tv); 1760 else 1761 do_gettimeofday(&tv); 1762 1763 if (!asoc && tv_lt(bear_cookie->expiration, tv)) { 1764 /* 1765 * Section 3.3.10.3 Stale Cookie Error (3) 1766 * 1767 * Cause of error 1768 * --------------- 1769 * Stale Cookie Error: Indicates the receipt of a valid State 1770 * Cookie that has expired. 1771 */ 1772 len = ntohs(chunk->chunk_hdr->length); 1773 *errp = sctp_make_op_error_space(asoc, chunk, len); 1774 if (*errp) { 1775 suseconds_t usecs = (tv.tv_sec - 1776 bear_cookie->expiration.tv_sec) * 1000000L + 1777 tv.tv_usec - bear_cookie->expiration.tv_usec; 1778 __be32 n = htonl(usecs); 1779 1780 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE, 1781 sizeof(n)); 1782 sctp_addto_chunk(*errp, sizeof(n), &n); 1783 *error = -SCTP_IERROR_STALE_COOKIE; 1784 } else 1785 *error = -SCTP_IERROR_NOMEM; 1786 1787 goto fail; 1788 } 1789 1790 /* Make a new base association. */ 1791 scope = sctp_scope(sctp_source(chunk)); 1792 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1793 if (!retval) { 1794 *error = -SCTP_IERROR_NOMEM; 1795 goto fail; 1796 } 1797 1798 /* Set up our peer's port number. */ 1799 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1800 1801 /* Populate the association from the cookie. */ 1802 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1803 1804 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1805 GFP_ATOMIC) < 0) { 1806 *error = -SCTP_IERROR_NOMEM; 1807 goto fail; 1808 } 1809 1810 /* Also, add the destination address. */ 1811 if (list_empty(&retval->base.bind_addr.address_list)) { 1812 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1813 SCTP_ADDR_SRC, GFP_ATOMIC); 1814 } 1815 1816 retval->next_tsn = retval->c.initial_tsn; 1817 retval->ctsn_ack_point = retval->next_tsn - 1; 1818 retval->addip_serial = retval->c.initial_tsn; 1819 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1820 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1821 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1822 1823 /* The INIT stuff will be done by the side effects. */ 1824 return retval; 1825 1826 fail: 1827 if (retval) 1828 sctp_association_free(retval); 1829 1830 return NULL; 1831 1832 malformed: 1833 /* Yikes! The packet is either corrupt or deliberately 1834 * malformed. 1835 */ 1836 *error = -SCTP_IERROR_MALFORMED; 1837 goto fail; 1838 } 1839 1840 /******************************************************************** 1841 * 3rd Level Abstractions 1842 ********************************************************************/ 1843 1844 struct __sctp_missing { 1845 __be32 num_missing; 1846 __be16 type; 1847 } __packed; 1848 1849 /* 1850 * Report a missing mandatory parameter. 1851 */ 1852 static int sctp_process_missing_param(const struct sctp_association *asoc, 1853 sctp_param_t paramtype, 1854 struct sctp_chunk *chunk, 1855 struct sctp_chunk **errp) 1856 { 1857 struct __sctp_missing report; 1858 __u16 len; 1859 1860 len = WORD_ROUND(sizeof(report)); 1861 1862 /* Make an ERROR chunk, preparing enough room for 1863 * returning multiple unknown parameters. 1864 */ 1865 if (!*errp) 1866 *errp = sctp_make_op_error_space(asoc, chunk, len); 1867 1868 if (*errp) { 1869 report.num_missing = htonl(1); 1870 report.type = paramtype; 1871 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1872 sizeof(report)); 1873 sctp_addto_chunk(*errp, sizeof(report), &report); 1874 } 1875 1876 /* Stop processing this chunk. */ 1877 return 0; 1878 } 1879 1880 /* Report an Invalid Mandatory Parameter. */ 1881 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1882 struct sctp_chunk *chunk, 1883 struct sctp_chunk **errp) 1884 { 1885 /* Invalid Mandatory Parameter Error has no payload. */ 1886 1887 if (!*errp) 1888 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1889 1890 if (*errp) 1891 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1892 1893 /* Stop processing this chunk. */ 1894 return 0; 1895 } 1896 1897 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1898 struct sctp_paramhdr *param, 1899 const struct sctp_chunk *chunk, 1900 struct sctp_chunk **errp) 1901 { 1902 /* This is a fatal error. Any accumulated non-fatal errors are 1903 * not reported. 1904 */ 1905 if (*errp) 1906 sctp_chunk_free(*errp); 1907 1908 /* Create an error chunk and fill it in with our payload. */ 1909 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1910 1911 return 0; 1912 } 1913 1914 1915 /* Do not attempt to handle the HOST_NAME parm. However, do 1916 * send back an indicator to the peer. 1917 */ 1918 static int sctp_process_hn_param(const struct sctp_association *asoc, 1919 union sctp_params param, 1920 struct sctp_chunk *chunk, 1921 struct sctp_chunk **errp) 1922 { 1923 __u16 len = ntohs(param.p->length); 1924 1925 /* Processing of the HOST_NAME parameter will generate an 1926 * ABORT. If we've accumulated any non-fatal errors, they 1927 * would be unrecognized parameters and we should not include 1928 * them in the ABORT. 1929 */ 1930 if (*errp) 1931 sctp_chunk_free(*errp); 1932 1933 *errp = sctp_make_op_error_space(asoc, chunk, len); 1934 1935 if (*errp) { 1936 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len); 1937 sctp_addto_chunk(*errp, len, param.v); 1938 } 1939 1940 /* Stop processing this chunk. */ 1941 return 0; 1942 } 1943 1944 static int sctp_verify_ext_param(struct net *net, union sctp_params param) 1945 { 1946 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 1947 int have_auth = 0; 1948 int have_asconf = 0; 1949 int i; 1950 1951 for (i = 0; i < num_ext; i++) { 1952 switch (param.ext->chunks[i]) { 1953 case SCTP_CID_AUTH: 1954 have_auth = 1; 1955 break; 1956 case SCTP_CID_ASCONF: 1957 case SCTP_CID_ASCONF_ACK: 1958 have_asconf = 1; 1959 break; 1960 } 1961 } 1962 1963 /* ADD-IP Security: The draft requires us to ABORT or ignore the 1964 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 1965 * only if ADD-IP is turned on and we are not backward-compatible 1966 * mode. 1967 */ 1968 if (net->sctp.addip_noauth) 1969 return 1; 1970 1971 if (net->sctp.addip_enable && !have_auth && have_asconf) 1972 return 0; 1973 1974 return 1; 1975 } 1976 1977 static void sctp_process_ext_param(struct sctp_association *asoc, 1978 union sctp_params param) 1979 { 1980 struct net *net = sock_net(asoc->base.sk); 1981 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 1982 int i; 1983 1984 for (i = 0; i < num_ext; i++) { 1985 switch (param.ext->chunks[i]) { 1986 case SCTP_CID_FWD_TSN: 1987 if (net->sctp.prsctp_enable && 1988 !asoc->peer.prsctp_capable) 1989 asoc->peer.prsctp_capable = 1; 1990 break; 1991 case SCTP_CID_AUTH: 1992 /* if the peer reports AUTH, assume that he 1993 * supports AUTH. 1994 */ 1995 if (net->sctp.auth_enable) 1996 asoc->peer.auth_capable = 1; 1997 break; 1998 case SCTP_CID_ASCONF: 1999 case SCTP_CID_ASCONF_ACK: 2000 if (net->sctp.addip_enable) 2001 asoc->peer.asconf_capable = 1; 2002 break; 2003 default: 2004 break; 2005 } 2006 } 2007 } 2008 2009 /* RFC 3.2.1 & the Implementers Guide 2.2. 2010 * 2011 * The Parameter Types are encoded such that the 2012 * highest-order two bits specify the action that must be 2013 * taken if the processing endpoint does not recognize the 2014 * Parameter Type. 2015 * 2016 * 00 - Stop processing this parameter; do not process any further 2017 * parameters within this chunk 2018 * 2019 * 01 - Stop processing this parameter, do not process any further 2020 * parameters within this chunk, and report the unrecognized 2021 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2022 * 2023 * 10 - Skip this parameter and continue processing. 2024 * 2025 * 11 - Skip this parameter and continue processing but 2026 * report the unrecognized parameter in an 2027 * 'Unrecognized Parameter' ERROR chunk. 2028 * 2029 * Return value: 2030 * SCTP_IERROR_NO_ERROR - continue with the chunk 2031 * SCTP_IERROR_ERROR - stop and report an error. 2032 * SCTP_IERROR_NOMEME - out of memory. 2033 */ 2034 static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc, 2035 union sctp_params param, 2036 struct sctp_chunk *chunk, 2037 struct sctp_chunk **errp) 2038 { 2039 int retval = SCTP_IERROR_NO_ERROR; 2040 2041 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2042 case SCTP_PARAM_ACTION_DISCARD: 2043 retval = SCTP_IERROR_ERROR; 2044 break; 2045 case SCTP_PARAM_ACTION_SKIP: 2046 break; 2047 case SCTP_PARAM_ACTION_DISCARD_ERR: 2048 retval = SCTP_IERROR_ERROR; 2049 /* Fall through */ 2050 case SCTP_PARAM_ACTION_SKIP_ERR: 2051 /* Make an ERROR chunk, preparing enough room for 2052 * returning multiple unknown parameters. 2053 */ 2054 if (NULL == *errp) 2055 *errp = sctp_make_op_error_fixed(asoc, chunk); 2056 2057 if (*errp) { 2058 if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2059 WORD_ROUND(ntohs(param.p->length)))) 2060 sctp_addto_chunk_fixed(*errp, 2061 WORD_ROUND(ntohs(param.p->length)), 2062 param.v); 2063 } else { 2064 /* If there is no memory for generating the ERROR 2065 * report as specified, an ABORT will be triggered 2066 * to the peer and the association won't be 2067 * established. 2068 */ 2069 retval = SCTP_IERROR_NOMEM; 2070 } 2071 break; 2072 default: 2073 break; 2074 } 2075 2076 return retval; 2077 } 2078 2079 /* Verify variable length parameters 2080 * Return values: 2081 * SCTP_IERROR_ABORT - trigger an ABORT 2082 * SCTP_IERROR_NOMEM - out of memory (abort) 2083 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2084 * SCTP_IERROR_NO_ERROR - continue with the chunk 2085 */ 2086 static sctp_ierror_t sctp_verify_param(struct net *net, 2087 const struct sctp_association *asoc, 2088 union sctp_params param, 2089 sctp_cid_t cid, 2090 struct sctp_chunk *chunk, 2091 struct sctp_chunk **err_chunk) 2092 { 2093 struct sctp_hmac_algo_param *hmacs; 2094 int retval = SCTP_IERROR_NO_ERROR; 2095 __u16 n_elt, id = 0; 2096 int i; 2097 2098 /* FIXME - This routine is not looking at each parameter per the 2099 * chunk type, i.e., unrecognized parameters should be further 2100 * identified based on the chunk id. 2101 */ 2102 2103 switch (param.p->type) { 2104 case SCTP_PARAM_IPV4_ADDRESS: 2105 case SCTP_PARAM_IPV6_ADDRESS: 2106 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2107 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2108 case SCTP_PARAM_STATE_COOKIE: 2109 case SCTP_PARAM_HEARTBEAT_INFO: 2110 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2111 case SCTP_PARAM_ECN_CAPABLE: 2112 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2113 break; 2114 2115 case SCTP_PARAM_SUPPORTED_EXT: 2116 if (!sctp_verify_ext_param(net, param)) 2117 return SCTP_IERROR_ABORT; 2118 break; 2119 2120 case SCTP_PARAM_SET_PRIMARY: 2121 if (net->sctp.addip_enable) 2122 break; 2123 goto fallthrough; 2124 2125 case SCTP_PARAM_HOST_NAME_ADDRESS: 2126 /* Tell the peer, we won't support this param. */ 2127 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2128 retval = SCTP_IERROR_ABORT; 2129 break; 2130 2131 case SCTP_PARAM_FWD_TSN_SUPPORT: 2132 if (net->sctp.prsctp_enable) 2133 break; 2134 goto fallthrough; 2135 2136 case SCTP_PARAM_RANDOM: 2137 if (!net->sctp.auth_enable) 2138 goto fallthrough; 2139 2140 /* SCTP-AUTH: Secion 6.1 2141 * If the random number is not 32 byte long the association 2142 * MUST be aborted. The ABORT chunk SHOULD contain the error 2143 * cause 'Protocol Violation'. 2144 */ 2145 if (SCTP_AUTH_RANDOM_LENGTH != 2146 ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) { 2147 sctp_process_inv_paramlength(asoc, param.p, 2148 chunk, err_chunk); 2149 retval = SCTP_IERROR_ABORT; 2150 } 2151 break; 2152 2153 case SCTP_PARAM_CHUNKS: 2154 if (!net->sctp.auth_enable) 2155 goto fallthrough; 2156 2157 /* SCTP-AUTH: Section 3.2 2158 * The CHUNKS parameter MUST be included once in the INIT or 2159 * INIT-ACK chunk if the sender wants to receive authenticated 2160 * chunks. Its maximum length is 260 bytes. 2161 */ 2162 if (260 < ntohs(param.p->length)) { 2163 sctp_process_inv_paramlength(asoc, param.p, 2164 chunk, err_chunk); 2165 retval = SCTP_IERROR_ABORT; 2166 } 2167 break; 2168 2169 case SCTP_PARAM_HMAC_ALGO: 2170 if (!net->sctp.auth_enable) 2171 goto fallthrough; 2172 2173 hmacs = (struct sctp_hmac_algo_param *)param.p; 2174 n_elt = (ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) >> 1; 2175 2176 /* SCTP-AUTH: Section 6.1 2177 * The HMAC algorithm based on SHA-1 MUST be supported and 2178 * included in the HMAC-ALGO parameter. 2179 */ 2180 for (i = 0; i < n_elt; i++) { 2181 id = ntohs(hmacs->hmac_ids[i]); 2182 2183 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2184 break; 2185 } 2186 2187 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2188 sctp_process_inv_paramlength(asoc, param.p, chunk, 2189 err_chunk); 2190 retval = SCTP_IERROR_ABORT; 2191 } 2192 break; 2193 fallthrough: 2194 default: 2195 SCTP_DEBUG_PRINTK("Unrecognized param: %d for chunk %d.\n", 2196 ntohs(param.p->type), cid); 2197 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2198 break; 2199 } 2200 return retval; 2201 } 2202 2203 /* Verify the INIT packet before we process it. */ 2204 int sctp_verify_init(struct net *net, const struct sctp_association *asoc, 2205 sctp_cid_t cid, 2206 sctp_init_chunk_t *peer_init, 2207 struct sctp_chunk *chunk, 2208 struct sctp_chunk **errp) 2209 { 2210 union sctp_params param; 2211 int has_cookie = 0; 2212 int result; 2213 2214 /* Verify stream values are non-zero. */ 2215 if ((0 == peer_init->init_hdr.num_outbound_streams) || 2216 (0 == peer_init->init_hdr.num_inbound_streams) || 2217 (0 == peer_init->init_hdr.init_tag) || 2218 (SCTP_DEFAULT_MINWINDOW > ntohl(peer_init->init_hdr.a_rwnd))) { 2219 2220 return sctp_process_inv_mandatory(asoc, chunk, errp); 2221 } 2222 2223 /* Check for missing mandatory parameters. */ 2224 sctp_walk_params(param, peer_init, init_hdr.params) { 2225 2226 if (SCTP_PARAM_STATE_COOKIE == param.p->type) 2227 has_cookie = 1; 2228 2229 } /* for (loop through all parameters) */ 2230 2231 /* There is a possibility that a parameter length was bad and 2232 * in that case we would have stoped walking the parameters. 2233 * The current param.p would point at the bad one. 2234 * Current consensus on the mailing list is to generate a PROTOCOL 2235 * VIOLATION error. We build the ERROR chunk here and let the normal 2236 * error handling code build and send the packet. 2237 */ 2238 if (param.v != (void*)chunk->chunk_end) 2239 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2240 2241 /* The only missing mandatory param possible today is 2242 * the state cookie for an INIT-ACK chunk. 2243 */ 2244 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2245 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2246 chunk, errp); 2247 2248 /* Verify all the variable length parameters */ 2249 sctp_walk_params(param, peer_init, init_hdr.params) { 2250 2251 result = sctp_verify_param(net, asoc, param, cid, chunk, errp); 2252 switch (result) { 2253 case SCTP_IERROR_ABORT: 2254 case SCTP_IERROR_NOMEM: 2255 return 0; 2256 case SCTP_IERROR_ERROR: 2257 return 1; 2258 case SCTP_IERROR_NO_ERROR: 2259 default: 2260 break; 2261 } 2262 2263 } /* for (loop through all parameters) */ 2264 2265 return 1; 2266 } 2267 2268 /* Unpack the parameters in an INIT packet into an association. 2269 * Returns 0 on failure, else success. 2270 * FIXME: This is an association method. 2271 */ 2272 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2273 const union sctp_addr *peer_addr, 2274 sctp_init_chunk_t *peer_init, gfp_t gfp) 2275 { 2276 struct net *net = sock_net(asoc->base.sk); 2277 union sctp_params param; 2278 struct sctp_transport *transport; 2279 struct list_head *pos, *temp; 2280 struct sctp_af *af; 2281 union sctp_addr addr; 2282 char *cookie; 2283 int src_match = 0; 2284 2285 /* We must include the address that the INIT packet came from. 2286 * This is the only address that matters for an INIT packet. 2287 * When processing a COOKIE ECHO, we retrieve the from address 2288 * of the INIT from the cookie. 2289 */ 2290 2291 /* This implementation defaults to making the first transport 2292 * added as the primary transport. The source address seems to 2293 * be a a better choice than any of the embedded addresses. 2294 */ 2295 if(!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2296 goto nomem; 2297 2298 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2299 src_match = 1; 2300 2301 /* Process the initialization parameters. */ 2302 sctp_walk_params(param, peer_init, init_hdr.params) { 2303 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2304 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2305 af = sctp_get_af_specific(param_type2af(param.p->type)); 2306 af->from_addr_param(&addr, param.addr, 2307 chunk->sctp_hdr->source, 0); 2308 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2309 src_match = 1; 2310 } 2311 2312 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2313 goto clean_up; 2314 } 2315 2316 /* source address of chunk may not match any valid address */ 2317 if (!src_match) 2318 goto clean_up; 2319 2320 /* AUTH: After processing the parameters, make sure that we 2321 * have all the required info to potentially do authentications. 2322 */ 2323 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2324 !asoc->peer.peer_hmacs)) 2325 asoc->peer.auth_capable = 0; 2326 2327 /* In a non-backward compatible mode, if the peer claims 2328 * support for ADD-IP but not AUTH, the ADD-IP spec states 2329 * that we MUST ABORT the association. Section 6. The section 2330 * also give us an option to silently ignore the packet, which 2331 * is what we'll do here. 2332 */ 2333 if (!net->sctp.addip_noauth && 2334 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2335 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2336 SCTP_PARAM_DEL_IP | 2337 SCTP_PARAM_SET_PRIMARY); 2338 asoc->peer.asconf_capable = 0; 2339 goto clean_up; 2340 } 2341 2342 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2343 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2344 transport = list_entry(pos, struct sctp_transport, transports); 2345 if (transport->state == SCTP_UNKNOWN) { 2346 sctp_assoc_rm_peer(asoc, transport); 2347 } 2348 } 2349 2350 /* The fixed INIT headers are always in network byte 2351 * order. 2352 */ 2353 asoc->peer.i.init_tag = 2354 ntohl(peer_init->init_hdr.init_tag); 2355 asoc->peer.i.a_rwnd = 2356 ntohl(peer_init->init_hdr.a_rwnd); 2357 asoc->peer.i.num_outbound_streams = 2358 ntohs(peer_init->init_hdr.num_outbound_streams); 2359 asoc->peer.i.num_inbound_streams = 2360 ntohs(peer_init->init_hdr.num_inbound_streams); 2361 asoc->peer.i.initial_tsn = 2362 ntohl(peer_init->init_hdr.initial_tsn); 2363 2364 /* Apply the upper bounds for output streams based on peer's 2365 * number of inbound streams. 2366 */ 2367 if (asoc->c.sinit_num_ostreams > 2368 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2369 asoc->c.sinit_num_ostreams = 2370 ntohs(peer_init->init_hdr.num_inbound_streams); 2371 } 2372 2373 if (asoc->c.sinit_max_instreams > 2374 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2375 asoc->c.sinit_max_instreams = 2376 ntohs(peer_init->init_hdr.num_outbound_streams); 2377 } 2378 2379 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2380 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2381 2382 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2383 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2384 2385 /* Copy cookie in case we need to resend COOKIE-ECHO. */ 2386 cookie = asoc->peer.cookie; 2387 if (cookie) { 2388 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp); 2389 if (!asoc->peer.cookie) 2390 goto clean_up; 2391 } 2392 2393 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2394 * high (for example, implementations MAY use the size of the receiver 2395 * advertised window). 2396 */ 2397 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2398 transports) { 2399 transport->ssthresh = asoc->peer.i.a_rwnd; 2400 } 2401 2402 /* Set up the TSN tracking pieces. */ 2403 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2404 asoc->peer.i.initial_tsn, gfp)) 2405 goto clean_up; 2406 2407 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2408 * 2409 * The stream sequence number in all the streams shall start 2410 * from 0 when the association is established. Also, when the 2411 * stream sequence number reaches the value 65535 the next 2412 * stream sequence number shall be set to 0. 2413 */ 2414 2415 /* Allocate storage for the negotiated streams if it is not a temporary 2416 * association. 2417 */ 2418 if (!asoc->temp) { 2419 int error; 2420 2421 asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams, 2422 asoc->c.sinit_num_ostreams, gfp); 2423 if (!asoc->ssnmap) 2424 goto clean_up; 2425 2426 error = sctp_assoc_set_id(asoc, gfp); 2427 if (error) 2428 goto clean_up; 2429 } 2430 2431 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2432 * 2433 * When an endpoint has an ASCONF signaled change to be sent to the 2434 * remote endpoint it should do the following: 2435 * ... 2436 * A2) A serial number should be assigned to the Chunk. The serial 2437 * number should be a monotonically increasing number. All serial 2438 * numbers are defined to be initialized at the start of the 2439 * association to the same value as the Initial TSN. 2440 */ 2441 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2442 return 1; 2443 2444 clean_up: 2445 /* Release the transport structures. */ 2446 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2447 transport = list_entry(pos, struct sctp_transport, transports); 2448 if (transport->state != SCTP_ACTIVE) 2449 sctp_assoc_rm_peer(asoc, transport); 2450 } 2451 2452 nomem: 2453 return 0; 2454 } 2455 2456 2457 /* Update asoc with the option described in param. 2458 * 2459 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2460 * 2461 * asoc is the association to update. 2462 * param is the variable length parameter to use for update. 2463 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2464 * If the current packet is an INIT we want to minimize the amount of 2465 * work we do. In particular, we should not build transport 2466 * structures for the addresses. 2467 */ 2468 static int sctp_process_param(struct sctp_association *asoc, 2469 union sctp_params param, 2470 const union sctp_addr *peer_addr, 2471 gfp_t gfp) 2472 { 2473 struct net *net = sock_net(asoc->base.sk); 2474 union sctp_addr addr; 2475 int i; 2476 __u16 sat; 2477 int retval = 1; 2478 sctp_scope_t scope; 2479 time_t stale; 2480 struct sctp_af *af; 2481 union sctp_addr_param *addr_param; 2482 struct sctp_transport *t; 2483 2484 /* We maintain all INIT parameters in network byte order all the 2485 * time. This allows us to not worry about whether the parameters 2486 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2487 */ 2488 switch (param.p->type) { 2489 case SCTP_PARAM_IPV6_ADDRESS: 2490 if (PF_INET6 != asoc->base.sk->sk_family) 2491 break; 2492 goto do_addr_param; 2493 2494 case SCTP_PARAM_IPV4_ADDRESS: 2495 /* v4 addresses are not allowed on v6-only socket */ 2496 if (ipv6_only_sock(asoc->base.sk)) 2497 break; 2498 do_addr_param: 2499 af = sctp_get_af_specific(param_type2af(param.p->type)); 2500 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); 2501 scope = sctp_scope(peer_addr); 2502 if (sctp_in_scope(net, &addr, scope)) 2503 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2504 return 0; 2505 break; 2506 2507 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2508 if (!net->sctp.cookie_preserve_enable) 2509 break; 2510 2511 stale = ntohl(param.life->lifespan_increment); 2512 2513 /* Suggested Cookie Life span increment's unit is msec, 2514 * (1/1000sec). 2515 */ 2516 asoc->cookie_life.tv_sec += stale / 1000; 2517 asoc->cookie_life.tv_usec += (stale % 1000) * 1000; 2518 break; 2519 2520 case SCTP_PARAM_HOST_NAME_ADDRESS: 2521 SCTP_DEBUG_PRINTK("unimplemented SCTP_HOST_NAME_ADDRESS\n"); 2522 break; 2523 2524 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2525 /* Turn off the default values first so we'll know which 2526 * ones are really set by the peer. 2527 */ 2528 asoc->peer.ipv4_address = 0; 2529 asoc->peer.ipv6_address = 0; 2530 2531 /* Assume that peer supports the address family 2532 * by which it sends a packet. 2533 */ 2534 if (peer_addr->sa.sa_family == AF_INET6) 2535 asoc->peer.ipv6_address = 1; 2536 else if (peer_addr->sa.sa_family == AF_INET) 2537 asoc->peer.ipv4_address = 1; 2538 2539 /* Cycle through address types; avoid divide by 0. */ 2540 sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2541 if (sat) 2542 sat /= sizeof(__u16); 2543 2544 for (i = 0; i < sat; ++i) { 2545 switch (param.sat->types[i]) { 2546 case SCTP_PARAM_IPV4_ADDRESS: 2547 asoc->peer.ipv4_address = 1; 2548 break; 2549 2550 case SCTP_PARAM_IPV6_ADDRESS: 2551 if (PF_INET6 == asoc->base.sk->sk_family) 2552 asoc->peer.ipv6_address = 1; 2553 break; 2554 2555 case SCTP_PARAM_HOST_NAME_ADDRESS: 2556 asoc->peer.hostname_address = 1; 2557 break; 2558 2559 default: /* Just ignore anything else. */ 2560 break; 2561 } 2562 } 2563 break; 2564 2565 case SCTP_PARAM_STATE_COOKIE: 2566 asoc->peer.cookie_len = 2567 ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2568 asoc->peer.cookie = param.cookie->body; 2569 break; 2570 2571 case SCTP_PARAM_HEARTBEAT_INFO: 2572 /* Would be odd to receive, but it causes no problems. */ 2573 break; 2574 2575 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2576 /* Rejected during verify stage. */ 2577 break; 2578 2579 case SCTP_PARAM_ECN_CAPABLE: 2580 asoc->peer.ecn_capable = 1; 2581 break; 2582 2583 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2584 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2585 break; 2586 2587 case SCTP_PARAM_SET_PRIMARY: 2588 if (!net->sctp.addip_enable) 2589 goto fall_through; 2590 2591 addr_param = param.v + sizeof(sctp_addip_param_t); 2592 2593 af = sctp_get_af_specific(param_type2af(param.p->type)); 2594 af->from_addr_param(&addr, addr_param, 2595 htons(asoc->peer.port), 0); 2596 2597 /* if the address is invalid, we can't process it. 2598 * XXX: see spec for what to do. 2599 */ 2600 if (!af->addr_valid(&addr, NULL, NULL)) 2601 break; 2602 2603 t = sctp_assoc_lookup_paddr(asoc, &addr); 2604 if (!t) 2605 break; 2606 2607 sctp_assoc_set_primary(asoc, t); 2608 break; 2609 2610 case SCTP_PARAM_SUPPORTED_EXT: 2611 sctp_process_ext_param(asoc, param); 2612 break; 2613 2614 case SCTP_PARAM_FWD_TSN_SUPPORT: 2615 if (net->sctp.prsctp_enable) { 2616 asoc->peer.prsctp_capable = 1; 2617 break; 2618 } 2619 /* Fall Through */ 2620 goto fall_through; 2621 2622 case SCTP_PARAM_RANDOM: 2623 if (!net->sctp.auth_enable) 2624 goto fall_through; 2625 2626 /* Save peer's random parameter */ 2627 asoc->peer.peer_random = kmemdup(param.p, 2628 ntohs(param.p->length), gfp); 2629 if (!asoc->peer.peer_random) { 2630 retval = 0; 2631 break; 2632 } 2633 break; 2634 2635 case SCTP_PARAM_HMAC_ALGO: 2636 if (!net->sctp.auth_enable) 2637 goto fall_through; 2638 2639 /* Save peer's HMAC list */ 2640 asoc->peer.peer_hmacs = kmemdup(param.p, 2641 ntohs(param.p->length), gfp); 2642 if (!asoc->peer.peer_hmacs) { 2643 retval = 0; 2644 break; 2645 } 2646 2647 /* Set the default HMAC the peer requested*/ 2648 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2649 break; 2650 2651 case SCTP_PARAM_CHUNKS: 2652 if (!net->sctp.auth_enable) 2653 goto fall_through; 2654 2655 asoc->peer.peer_chunks = kmemdup(param.p, 2656 ntohs(param.p->length), gfp); 2657 if (!asoc->peer.peer_chunks) 2658 retval = 0; 2659 break; 2660 fall_through: 2661 default: 2662 /* Any unrecognized parameters should have been caught 2663 * and handled by sctp_verify_param() which should be 2664 * called prior to this routine. Simply log the error 2665 * here. 2666 */ 2667 SCTP_DEBUG_PRINTK("Ignoring param: %d for association %p.\n", 2668 ntohs(param.p->type), asoc); 2669 break; 2670 } 2671 2672 return retval; 2673 } 2674 2675 /* Select a new verification tag. */ 2676 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2677 { 2678 /* I believe that this random number generator complies with RFC1750. 2679 * A tag of 0 is reserved for special cases (e.g. INIT). 2680 */ 2681 __u32 x; 2682 2683 do { 2684 get_random_bytes(&x, sizeof(__u32)); 2685 } while (x == 0); 2686 2687 return x; 2688 } 2689 2690 /* Select an initial TSN to send during startup. */ 2691 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2692 { 2693 __u32 retval; 2694 2695 get_random_bytes(&retval, sizeof(__u32)); 2696 return retval; 2697 } 2698 2699 /* 2700 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2701 * 0 1 2 3 2702 * 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 2703 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2704 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2705 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2706 * | Serial Number | 2707 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2708 * | Address Parameter | 2709 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2710 * | ASCONF Parameter #1 | 2711 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2712 * \ \ 2713 * / .... / 2714 * \ \ 2715 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2716 * | ASCONF Parameter #N | 2717 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2718 * 2719 * Address Parameter and other parameter will not be wrapped in this function 2720 */ 2721 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2722 union sctp_addr *addr, 2723 int vparam_len) 2724 { 2725 sctp_addiphdr_t asconf; 2726 struct sctp_chunk *retval; 2727 int length = sizeof(asconf) + vparam_len; 2728 union sctp_addr_param addrparam; 2729 int addrlen; 2730 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2731 2732 addrlen = af->to_addr_param(addr, &addrparam); 2733 if (!addrlen) 2734 return NULL; 2735 length += addrlen; 2736 2737 /* Create the chunk. */ 2738 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF, 0, length); 2739 if (!retval) 2740 return NULL; 2741 2742 asconf.serial = htonl(asoc->addip_serial++); 2743 2744 retval->subh.addip_hdr = 2745 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2746 retval->param_hdr.v = 2747 sctp_addto_chunk(retval, addrlen, &addrparam); 2748 2749 return retval; 2750 } 2751 2752 /* ADDIP 2753 * 3.2.1 Add IP Address 2754 * 0 1 2 3 2755 * 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 2756 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2757 * | Type = 0xC001 | Length = Variable | 2758 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2759 * | ASCONF-Request Correlation ID | 2760 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2761 * | Address Parameter | 2762 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2763 * 2764 * 3.2.2 Delete IP Address 2765 * 0 1 2 3 2766 * 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 2767 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2768 * | Type = 0xC002 | Length = Variable | 2769 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2770 * | ASCONF-Request Correlation ID | 2771 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2772 * | Address Parameter | 2773 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2774 * 2775 */ 2776 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2777 union sctp_addr *laddr, 2778 struct sockaddr *addrs, 2779 int addrcnt, 2780 __be16 flags) 2781 { 2782 sctp_addip_param_t param; 2783 struct sctp_chunk *retval; 2784 union sctp_addr_param addr_param; 2785 union sctp_addr *addr; 2786 void *addr_buf; 2787 struct sctp_af *af; 2788 int paramlen = sizeof(param); 2789 int addr_param_len = 0; 2790 int totallen = 0; 2791 int i; 2792 int del_pickup = 0; 2793 2794 /* Get total length of all the address parameters. */ 2795 addr_buf = addrs; 2796 for (i = 0; i < addrcnt; i++) { 2797 addr = addr_buf; 2798 af = sctp_get_af_specific(addr->v4.sin_family); 2799 addr_param_len = af->to_addr_param(addr, &addr_param); 2800 2801 totallen += paramlen; 2802 totallen += addr_param_len; 2803 2804 addr_buf += af->sockaddr_len; 2805 if (asoc->asconf_addr_del_pending && !del_pickup) { 2806 /* reuse the parameter length from the same scope one */ 2807 totallen += paramlen; 2808 totallen += addr_param_len; 2809 del_pickup = 1; 2810 SCTP_DEBUG_PRINTK("mkasconf_update_ip: picked same-scope del_pending addr, totallen for all addresses is %d\n", totallen); 2811 } 2812 } 2813 2814 /* Create an asconf chunk with the required length. */ 2815 retval = sctp_make_asconf(asoc, laddr, totallen); 2816 if (!retval) 2817 return NULL; 2818 2819 /* Add the address parameters to the asconf chunk. */ 2820 addr_buf = addrs; 2821 for (i = 0; i < addrcnt; i++) { 2822 addr = addr_buf; 2823 af = sctp_get_af_specific(addr->v4.sin_family); 2824 addr_param_len = af->to_addr_param(addr, &addr_param); 2825 param.param_hdr.type = flags; 2826 param.param_hdr.length = htons(paramlen + addr_param_len); 2827 param.crr_id = i; 2828 2829 sctp_addto_chunk(retval, paramlen, ¶m); 2830 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2831 2832 addr_buf += af->sockaddr_len; 2833 } 2834 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2835 addr = asoc->asconf_addr_del_pending; 2836 af = sctp_get_af_specific(addr->v4.sin_family); 2837 addr_param_len = af->to_addr_param(addr, &addr_param); 2838 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2839 param.param_hdr.length = htons(paramlen + addr_param_len); 2840 param.crr_id = i; 2841 2842 sctp_addto_chunk(retval, paramlen, ¶m); 2843 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2844 } 2845 return retval; 2846 } 2847 2848 /* ADDIP 2849 * 3.2.4 Set Primary IP Address 2850 * 0 1 2 3 2851 * 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 2852 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2853 * | Type =0xC004 | Length = Variable | 2854 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2855 * | ASCONF-Request Correlation ID | 2856 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2857 * | Address Parameter | 2858 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2859 * 2860 * Create an ASCONF chunk with Set Primary IP address parameter. 2861 */ 2862 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2863 union sctp_addr *addr) 2864 { 2865 sctp_addip_param_t param; 2866 struct sctp_chunk *retval; 2867 int len = sizeof(param); 2868 union sctp_addr_param addrparam; 2869 int addrlen; 2870 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2871 2872 addrlen = af->to_addr_param(addr, &addrparam); 2873 if (!addrlen) 2874 return NULL; 2875 len += addrlen; 2876 2877 /* Create the chunk and make asconf header. */ 2878 retval = sctp_make_asconf(asoc, addr, len); 2879 if (!retval) 2880 return NULL; 2881 2882 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2883 param.param_hdr.length = htons(len); 2884 param.crr_id = 0; 2885 2886 sctp_addto_chunk(retval, sizeof(param), ¶m); 2887 sctp_addto_chunk(retval, addrlen, &addrparam); 2888 2889 return retval; 2890 } 2891 2892 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2893 * 0 1 2 3 2894 * 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 2895 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2896 * | Type = 0x80 | Chunk Flags | Chunk Length | 2897 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2898 * | Serial Number | 2899 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2900 * | ASCONF Parameter Response#1 | 2901 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2902 * \ \ 2903 * / .... / 2904 * \ \ 2905 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2906 * | ASCONF Parameter Response#N | 2907 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2908 * 2909 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2910 */ 2911 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2912 __u32 serial, int vparam_len) 2913 { 2914 sctp_addiphdr_t asconf; 2915 struct sctp_chunk *retval; 2916 int length = sizeof(asconf) + vparam_len; 2917 2918 /* Create the chunk. */ 2919 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF_ACK, 0, length); 2920 if (!retval) 2921 return NULL; 2922 2923 asconf.serial = htonl(serial); 2924 2925 retval->subh.addip_hdr = 2926 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2927 2928 return retval; 2929 } 2930 2931 /* Add response parameters to an ASCONF_ACK chunk. */ 2932 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2933 __be16 err_code, sctp_addip_param_t *asconf_param) 2934 { 2935 sctp_addip_param_t ack_param; 2936 sctp_errhdr_t err_param; 2937 int asconf_param_len = 0; 2938 int err_param_len = 0; 2939 __be16 response_type; 2940 2941 if (SCTP_ERROR_NO_ERROR == err_code) { 2942 response_type = SCTP_PARAM_SUCCESS_REPORT; 2943 } else { 2944 response_type = SCTP_PARAM_ERR_CAUSE; 2945 err_param_len = sizeof(err_param); 2946 if (asconf_param) 2947 asconf_param_len = 2948 ntohs(asconf_param->param_hdr.length); 2949 } 2950 2951 /* Add Success Indication or Error Cause Indication parameter. */ 2952 ack_param.param_hdr.type = response_type; 2953 ack_param.param_hdr.length = htons(sizeof(ack_param) + 2954 err_param_len + 2955 asconf_param_len); 2956 ack_param.crr_id = crr_id; 2957 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 2958 2959 if (SCTP_ERROR_NO_ERROR == err_code) 2960 return; 2961 2962 /* Add Error Cause parameter. */ 2963 err_param.cause = err_code; 2964 err_param.length = htons(err_param_len + asconf_param_len); 2965 sctp_addto_chunk(chunk, err_param_len, &err_param); 2966 2967 /* Add the failed TLV copied from ASCONF chunk. */ 2968 if (asconf_param) 2969 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 2970 } 2971 2972 /* Process a asconf parameter. */ 2973 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 2974 struct sctp_chunk *asconf, 2975 sctp_addip_param_t *asconf_param) 2976 { 2977 struct sctp_transport *peer; 2978 struct sctp_af *af; 2979 union sctp_addr addr; 2980 union sctp_addr_param *addr_param; 2981 2982 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t); 2983 2984 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 2985 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 2986 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 2987 return SCTP_ERROR_UNKNOWN_PARAM; 2988 2989 switch (addr_param->p.type) { 2990 case SCTP_PARAM_IPV6_ADDRESS: 2991 if (!asoc->peer.ipv6_address) 2992 return SCTP_ERROR_DNS_FAILED; 2993 break; 2994 case SCTP_PARAM_IPV4_ADDRESS: 2995 if (!asoc->peer.ipv4_address) 2996 return SCTP_ERROR_DNS_FAILED; 2997 break; 2998 default: 2999 return SCTP_ERROR_DNS_FAILED; 3000 } 3001 3002 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3003 if (unlikely(!af)) 3004 return SCTP_ERROR_DNS_FAILED; 3005 3006 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); 3007 3008 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3009 * or multicast address. 3010 * (note: wildcard is permitted and requires special handling so 3011 * make sure we check for that) 3012 */ 3013 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3014 return SCTP_ERROR_DNS_FAILED; 3015 3016 switch (asconf_param->param_hdr.type) { 3017 case SCTP_PARAM_ADD_IP: 3018 /* Section 4.2.1: 3019 * If the address 0.0.0.0 or ::0 is provided, the source 3020 * address of the packet MUST be added. 3021 */ 3022 if (af->is_any(&addr)) 3023 memcpy(&addr, &asconf->source, sizeof(addr)); 3024 3025 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3026 * request and does not have the local resources to add this 3027 * new address to the association, it MUST return an Error 3028 * Cause TLV set to the new error code 'Operation Refused 3029 * Due to Resource Shortage'. 3030 */ 3031 3032 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3033 if (!peer) 3034 return SCTP_ERROR_RSRC_LOW; 3035 3036 /* Start the heartbeat timer. */ 3037 if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer))) 3038 sctp_transport_hold(peer); 3039 asoc->new_transport = peer; 3040 break; 3041 case SCTP_PARAM_DEL_IP: 3042 /* ADDIP 4.3 D7) If a request is received to delete the 3043 * last remaining IP address of a peer endpoint, the receiver 3044 * MUST send an Error Cause TLV with the error cause set to the 3045 * new error code 'Request to Delete Last Remaining IP Address'. 3046 */ 3047 if (asoc->peer.transport_count == 1) 3048 return SCTP_ERROR_DEL_LAST_IP; 3049 3050 /* ADDIP 4.3 D8) If a request is received to delete an IP 3051 * address which is also the source address of the IP packet 3052 * which contained the ASCONF chunk, the receiver MUST reject 3053 * this request. To reject the request the receiver MUST send 3054 * an Error Cause TLV set to the new error code 'Request to 3055 * Delete Source IP Address' 3056 */ 3057 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3058 return SCTP_ERROR_DEL_SRC_IP; 3059 3060 /* Section 4.2.2 3061 * If the address 0.0.0.0 or ::0 is provided, all 3062 * addresses of the peer except the source address of the 3063 * packet MUST be deleted. 3064 */ 3065 if (af->is_any(&addr)) { 3066 sctp_assoc_set_primary(asoc, asconf->transport); 3067 sctp_assoc_del_nonprimary_peers(asoc, 3068 asconf->transport); 3069 } else 3070 sctp_assoc_del_peer(asoc, &addr); 3071 break; 3072 case SCTP_PARAM_SET_PRIMARY: 3073 /* ADDIP Section 4.2.4 3074 * If the address 0.0.0.0 or ::0 is provided, the receiver 3075 * MAY mark the source address of the packet as its 3076 * primary. 3077 */ 3078 if (af->is_any(&addr)) 3079 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr)); 3080 3081 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3082 if (!peer) 3083 return SCTP_ERROR_DNS_FAILED; 3084 3085 sctp_assoc_set_primary(asoc, peer); 3086 break; 3087 } 3088 3089 return SCTP_ERROR_NO_ERROR; 3090 } 3091 3092 /* Verify the ASCONF packet before we process it. */ 3093 int sctp_verify_asconf(const struct sctp_association *asoc, 3094 struct sctp_paramhdr *param_hdr, void *chunk_end, 3095 struct sctp_paramhdr **errp) { 3096 sctp_addip_param_t *asconf_param; 3097 union sctp_params param; 3098 int length, plen; 3099 3100 param.v = (sctp_paramhdr_t *) param_hdr; 3101 while (param.v <= chunk_end - sizeof(sctp_paramhdr_t)) { 3102 length = ntohs(param.p->length); 3103 *errp = param.p; 3104 3105 if (param.v > chunk_end - length || 3106 length < sizeof(sctp_paramhdr_t)) 3107 return 0; 3108 3109 switch (param.p->type) { 3110 case SCTP_PARAM_ADD_IP: 3111 case SCTP_PARAM_DEL_IP: 3112 case SCTP_PARAM_SET_PRIMARY: 3113 asconf_param = (sctp_addip_param_t *)param.v; 3114 plen = ntohs(asconf_param->param_hdr.length); 3115 if (plen < sizeof(sctp_addip_param_t) + 3116 sizeof(sctp_paramhdr_t)) 3117 return 0; 3118 break; 3119 case SCTP_PARAM_SUCCESS_REPORT: 3120 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3121 if (length != sizeof(sctp_addip_param_t)) 3122 return 0; 3123 3124 break; 3125 default: 3126 break; 3127 } 3128 3129 param.v += WORD_ROUND(length); 3130 } 3131 3132 if (param.v != chunk_end) 3133 return 0; 3134 3135 return 1; 3136 } 3137 3138 /* Process an incoming ASCONF chunk with the next expected serial no. and 3139 * return an ASCONF_ACK chunk to be sent in response. 3140 */ 3141 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3142 struct sctp_chunk *asconf) 3143 { 3144 sctp_addiphdr_t *hdr; 3145 union sctp_addr_param *addr_param; 3146 sctp_addip_param_t *asconf_param; 3147 struct sctp_chunk *asconf_ack; 3148 3149 __be16 err_code; 3150 int length = 0; 3151 int chunk_len; 3152 __u32 serial; 3153 int all_param_pass = 1; 3154 3155 chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t); 3156 hdr = (sctp_addiphdr_t *)asconf->skb->data; 3157 serial = ntohl(hdr->serial); 3158 3159 /* Skip the addiphdr and store a pointer to address parameter. */ 3160 length = sizeof(sctp_addiphdr_t); 3161 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3162 chunk_len -= length; 3163 3164 /* Skip the address parameter and store a pointer to the first 3165 * asconf parameter. 3166 */ 3167 length = ntohs(addr_param->p.length); 3168 asconf_param = (void *)addr_param + length; 3169 chunk_len -= length; 3170 3171 /* create an ASCONF_ACK chunk. 3172 * Based on the definitions of parameters, we know that the size of 3173 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3174 * parameters. 3175 */ 3176 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3177 if (!asconf_ack) 3178 goto done; 3179 3180 /* Process the TLVs contained within the ASCONF chunk. */ 3181 while (chunk_len > 0) { 3182 err_code = sctp_process_asconf_param(asoc, asconf, 3183 asconf_param); 3184 /* ADDIP 4.1 A7) 3185 * If an error response is received for a TLV parameter, 3186 * all TLVs with no response before the failed TLV are 3187 * considered successful if not reported. All TLVs after 3188 * the failed response are considered unsuccessful unless 3189 * a specific success indication is present for the parameter. 3190 */ 3191 if (SCTP_ERROR_NO_ERROR != err_code) 3192 all_param_pass = 0; 3193 3194 if (!all_param_pass) 3195 sctp_add_asconf_response(asconf_ack, 3196 asconf_param->crr_id, err_code, 3197 asconf_param); 3198 3199 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3200 * an IP address sends an 'Out of Resource' in its response, it 3201 * MUST also fail any subsequent add or delete requests bundled 3202 * in the ASCONF. 3203 */ 3204 if (SCTP_ERROR_RSRC_LOW == err_code) 3205 goto done; 3206 3207 /* Move to the next ASCONF param. */ 3208 length = ntohs(asconf_param->param_hdr.length); 3209 asconf_param = (void *)asconf_param + length; 3210 chunk_len -= length; 3211 } 3212 3213 done: 3214 asoc->peer.addip_serial++; 3215 3216 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3217 * after freeing the reference to old asconf ack if any. 3218 */ 3219 if (asconf_ack) { 3220 sctp_chunk_hold(asconf_ack); 3221 list_add_tail(&asconf_ack->transmitted_list, 3222 &asoc->asconf_ack_list); 3223 } 3224 3225 return asconf_ack; 3226 } 3227 3228 /* Process a asconf parameter that is successfully acked. */ 3229 static void sctp_asconf_param_success(struct sctp_association *asoc, 3230 sctp_addip_param_t *asconf_param) 3231 { 3232 struct sctp_af *af; 3233 union sctp_addr addr; 3234 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3235 union sctp_addr_param *addr_param; 3236 struct sctp_transport *transport; 3237 struct sctp_sockaddr_entry *saddr; 3238 3239 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t); 3240 3241 /* We have checked the packet before, so we do not check again. */ 3242 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3243 af->from_addr_param(&addr, addr_param, htons(bp->port), 0); 3244 3245 switch (asconf_param->param_hdr.type) { 3246 case SCTP_PARAM_ADD_IP: 3247 /* This is always done in BH context with a socket lock 3248 * held, so the list can not change. 3249 */ 3250 local_bh_disable(); 3251 list_for_each_entry(saddr, &bp->address_list, list) { 3252 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3253 saddr->state = SCTP_ADDR_SRC; 3254 } 3255 local_bh_enable(); 3256 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3257 transports) { 3258 dst_release(transport->dst); 3259 transport->dst = NULL; 3260 } 3261 break; 3262 case SCTP_PARAM_DEL_IP: 3263 local_bh_disable(); 3264 sctp_del_bind_addr(bp, &addr); 3265 if (asoc->asconf_addr_del_pending != NULL && 3266 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3267 kfree(asoc->asconf_addr_del_pending); 3268 asoc->asconf_addr_del_pending = NULL; 3269 } 3270 local_bh_enable(); 3271 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3272 transports) { 3273 dst_release(transport->dst); 3274 transport->dst = NULL; 3275 } 3276 break; 3277 default: 3278 break; 3279 } 3280 } 3281 3282 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3283 * for the given asconf parameter. If there is no response for this parameter, 3284 * return the error code based on the third argument 'no_err'. 3285 * ADDIP 4.1 3286 * A7) If an error response is received for a TLV parameter, all TLVs with no 3287 * response before the failed TLV are considered successful if not reported. 3288 * All TLVs after the failed response are considered unsuccessful unless a 3289 * specific success indication is present for the parameter. 3290 */ 3291 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3292 sctp_addip_param_t *asconf_param, 3293 int no_err) 3294 { 3295 sctp_addip_param_t *asconf_ack_param; 3296 sctp_errhdr_t *err_param; 3297 int length; 3298 int asconf_ack_len; 3299 __be16 err_code; 3300 3301 if (no_err) 3302 err_code = SCTP_ERROR_NO_ERROR; 3303 else 3304 err_code = SCTP_ERROR_REQ_REFUSED; 3305 3306 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3307 sizeof(sctp_chunkhdr_t); 3308 3309 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3310 * the first asconf_ack parameter. 3311 */ 3312 length = sizeof(sctp_addiphdr_t); 3313 asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data + 3314 length); 3315 asconf_ack_len -= length; 3316 3317 while (asconf_ack_len > 0) { 3318 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3319 switch(asconf_ack_param->param_hdr.type) { 3320 case SCTP_PARAM_SUCCESS_REPORT: 3321 return SCTP_ERROR_NO_ERROR; 3322 case SCTP_PARAM_ERR_CAUSE: 3323 length = sizeof(sctp_addip_param_t); 3324 err_param = (void *)asconf_ack_param + length; 3325 asconf_ack_len -= length; 3326 if (asconf_ack_len > 0) 3327 return err_param->cause; 3328 else 3329 return SCTP_ERROR_INV_PARAM; 3330 break; 3331 default: 3332 return SCTP_ERROR_INV_PARAM; 3333 } 3334 } 3335 3336 length = ntohs(asconf_ack_param->param_hdr.length); 3337 asconf_ack_param = (void *)asconf_ack_param + length; 3338 asconf_ack_len -= length; 3339 } 3340 3341 return err_code; 3342 } 3343 3344 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3345 int sctp_process_asconf_ack(struct sctp_association *asoc, 3346 struct sctp_chunk *asconf_ack) 3347 { 3348 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3349 union sctp_addr_param *addr_param; 3350 sctp_addip_param_t *asconf_param; 3351 int length = 0; 3352 int asconf_len = asconf->skb->len; 3353 int all_param_pass = 0; 3354 int no_err = 1; 3355 int retval = 0; 3356 __be16 err_code = SCTP_ERROR_NO_ERROR; 3357 3358 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3359 * a pointer to address parameter. 3360 */ 3361 length = sizeof(sctp_addip_chunk_t); 3362 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3363 asconf_len -= length; 3364 3365 /* Skip the address parameter in the last asconf sent and store a 3366 * pointer to the first asconf parameter. 3367 */ 3368 length = ntohs(addr_param->p.length); 3369 asconf_param = (void *)addr_param + length; 3370 asconf_len -= length; 3371 3372 /* ADDIP 4.1 3373 * A8) If there is no response(s) to specific TLV parameter(s), and no 3374 * failures are indicated, then all request(s) are considered 3375 * successful. 3376 */ 3377 if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t)) 3378 all_param_pass = 1; 3379 3380 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3381 while (asconf_len > 0) { 3382 if (all_param_pass) 3383 err_code = SCTP_ERROR_NO_ERROR; 3384 else { 3385 err_code = sctp_get_asconf_response(asconf_ack, 3386 asconf_param, 3387 no_err); 3388 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3389 no_err = 0; 3390 } 3391 3392 switch (err_code) { 3393 case SCTP_ERROR_NO_ERROR: 3394 sctp_asconf_param_success(asoc, asconf_param); 3395 break; 3396 3397 case SCTP_ERROR_RSRC_LOW: 3398 retval = 1; 3399 break; 3400 3401 case SCTP_ERROR_UNKNOWN_PARAM: 3402 /* Disable sending this type of asconf parameter in 3403 * future. 3404 */ 3405 asoc->peer.addip_disabled_mask |= 3406 asconf_param->param_hdr.type; 3407 break; 3408 3409 case SCTP_ERROR_REQ_REFUSED: 3410 case SCTP_ERROR_DEL_LAST_IP: 3411 case SCTP_ERROR_DEL_SRC_IP: 3412 default: 3413 break; 3414 } 3415 3416 /* Skip the processed asconf parameter and move to the next 3417 * one. 3418 */ 3419 length = ntohs(asconf_param->param_hdr.length); 3420 asconf_param = (void *)asconf_param + length; 3421 asconf_len -= length; 3422 } 3423 3424 if (no_err && asoc->src_out_of_asoc_ok) { 3425 asoc->src_out_of_asoc_ok = 0; 3426 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3427 } 3428 3429 /* Free the cached last sent asconf chunk. */ 3430 list_del_init(&asconf->transmitted_list); 3431 sctp_chunk_free(asconf); 3432 asoc->addip_last_asconf = NULL; 3433 3434 return retval; 3435 } 3436 3437 /* Make a FWD TSN chunk. */ 3438 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3439 __u32 new_cum_tsn, size_t nstreams, 3440 struct sctp_fwdtsn_skip *skiplist) 3441 { 3442 struct sctp_chunk *retval = NULL; 3443 struct sctp_fwdtsn_hdr ftsn_hdr; 3444 struct sctp_fwdtsn_skip skip; 3445 size_t hint; 3446 int i; 3447 3448 hint = (nstreams + 1) * sizeof(__u32); 3449 3450 retval = sctp_make_chunk(asoc, SCTP_CID_FWD_TSN, 0, hint); 3451 3452 if (!retval) 3453 return NULL; 3454 3455 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3456 retval->subh.fwdtsn_hdr = 3457 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3458 3459 for (i = 0; i < nstreams; i++) { 3460 skip.stream = skiplist[i].stream; 3461 skip.ssn = skiplist[i].ssn; 3462 sctp_addto_chunk(retval, sizeof(skip), &skip); 3463 } 3464 3465 return retval; 3466 } 3467