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 aptr->stats.idupchunks += num_dup_tsns; 809 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, 810 sctp_tsnmap_get_dups(map)); 811 } 812 /* Once we have a sack generated, check to see what our sack 813 * generation is, if its 0, reset the transports to 0, and reset 814 * the association generation to 1 815 * 816 * The idea is that zero is never used as a valid generation for the 817 * association so no transport will match after a wrap event like this, 818 * Until the next sack 819 */ 820 if (++aptr->peer.sack_generation == 0) { 821 list_for_each_entry(trans, &asoc->peer.transport_addr_list, 822 transports) 823 trans->sack_generation = 0; 824 aptr->peer.sack_generation = 1; 825 } 826 nodata: 827 return retval; 828 } 829 830 /* Make a SHUTDOWN chunk. */ 831 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 832 const struct sctp_chunk *chunk) 833 { 834 struct sctp_chunk *retval; 835 sctp_shutdownhdr_t shut; 836 __u32 ctsn; 837 838 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 839 shut.cum_tsn_ack = htonl(ctsn); 840 841 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN, 0, 842 sizeof(sctp_shutdownhdr_t)); 843 if (!retval) 844 goto nodata; 845 846 retval->subh.shutdown_hdr = 847 sctp_addto_chunk(retval, sizeof(shut), &shut); 848 849 if (chunk) 850 retval->transport = chunk->transport; 851 nodata: 852 return retval; 853 } 854 855 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 856 const struct sctp_chunk *chunk) 857 { 858 struct sctp_chunk *retval; 859 860 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0); 861 862 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 863 * 864 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 865 * HEARTBEAT ACK, * etc.) to the same destination transport 866 * address from which it * received the DATA or control chunk 867 * to which it is replying. 868 * 869 * [ACK back to where the SHUTDOWN came from.] 870 */ 871 if (retval && chunk) 872 retval->transport = chunk->transport; 873 874 return retval; 875 } 876 877 struct sctp_chunk *sctp_make_shutdown_complete( 878 const struct sctp_association *asoc, 879 const struct sctp_chunk *chunk) 880 { 881 struct sctp_chunk *retval; 882 __u8 flags = 0; 883 884 /* Set the T-bit if we have no association (vtag will be 885 * reflected) 886 */ 887 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; 888 889 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0); 890 891 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 892 * 893 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 894 * HEARTBEAT ACK, * etc.) to the same destination transport 895 * address from which it * received the DATA or control chunk 896 * to which it is replying. 897 * 898 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK 899 * came from.] 900 */ 901 if (retval && chunk) 902 retval->transport = chunk->transport; 903 904 return retval; 905 } 906 907 /* Create an ABORT. Note that we set the T bit if we have no 908 * association, except when responding to an INIT (sctpimpguide 2.41). 909 */ 910 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 911 const struct sctp_chunk *chunk, 912 const size_t hint) 913 { 914 struct sctp_chunk *retval; 915 __u8 flags = 0; 916 917 /* Set the T-bit if we have no association and 'chunk' is not 918 * an INIT (vtag will be reflected). 919 */ 920 if (!asoc) { 921 if (chunk && chunk->chunk_hdr && 922 chunk->chunk_hdr->type == SCTP_CID_INIT) 923 flags = 0; 924 else 925 flags = SCTP_CHUNK_FLAG_T; 926 } 927 928 retval = sctp_make_chunk(asoc, SCTP_CID_ABORT, flags, hint); 929 930 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 931 * 932 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 933 * HEARTBEAT ACK, * etc.) to the same destination transport 934 * address from which it * received the DATA or control chunk 935 * to which it is replying. 936 * 937 * [ABORT back to where the offender came from.] 938 */ 939 if (retval && chunk) 940 retval->transport = chunk->transport; 941 942 return retval; 943 } 944 945 /* Helper to create ABORT with a NO_USER_DATA error. */ 946 struct sctp_chunk *sctp_make_abort_no_data( 947 const struct sctp_association *asoc, 948 const struct sctp_chunk *chunk, __u32 tsn) 949 { 950 struct sctp_chunk *retval; 951 __be32 payload; 952 953 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) 954 + sizeof(tsn)); 955 956 if (!retval) 957 goto no_mem; 958 959 /* Put the tsn back into network byte order. */ 960 payload = htonl(tsn); 961 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload)); 962 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload); 963 964 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 965 * 966 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 967 * HEARTBEAT ACK, * etc.) to the same destination transport 968 * address from which it * received the DATA or control chunk 969 * to which it is replying. 970 * 971 * [ABORT back to where the offender came from.] 972 */ 973 if (chunk) 974 retval->transport = chunk->transport; 975 976 no_mem: 977 return retval; 978 } 979 980 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ 981 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 982 const struct msghdr *msg, 983 size_t paylen) 984 { 985 struct sctp_chunk *retval; 986 void *payload = NULL; 987 int err; 988 989 retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen); 990 if (!retval) 991 goto err_chunk; 992 993 if (paylen) { 994 /* Put the msg_iov together into payload. */ 995 payload = kmalloc(paylen, GFP_KERNEL); 996 if (!payload) 997 goto err_payload; 998 999 err = memcpy_fromiovec(payload, msg->msg_iov, paylen); 1000 if (err < 0) 1001 goto err_copy; 1002 } 1003 1004 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); 1005 sctp_addto_chunk(retval, paylen, payload); 1006 1007 if (paylen) 1008 kfree(payload); 1009 1010 return retval; 1011 1012 err_copy: 1013 kfree(payload); 1014 err_payload: 1015 sctp_chunk_free(retval); 1016 retval = NULL; 1017 err_chunk: 1018 return retval; 1019 } 1020 1021 /* Append bytes to the end of a parameter. Will panic if chunk is not big 1022 * enough. 1023 */ 1024 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 1025 const void *data) 1026 { 1027 void *target; 1028 int chunklen = ntohs(chunk->chunk_hdr->length); 1029 1030 target = skb_put(chunk->skb, len); 1031 1032 if (data) 1033 memcpy(target, data, len); 1034 else 1035 memset(target, 0, len); 1036 1037 /* Adjust the chunk length field. */ 1038 chunk->chunk_hdr->length = htons(chunklen + len); 1039 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1040 1041 return target; 1042 } 1043 1044 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ 1045 struct sctp_chunk *sctp_make_abort_violation( 1046 const struct sctp_association *asoc, 1047 const struct sctp_chunk *chunk, 1048 const __u8 *payload, 1049 const size_t paylen) 1050 { 1051 struct sctp_chunk *retval; 1052 struct sctp_paramhdr phdr; 1053 1054 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen 1055 + sizeof(sctp_paramhdr_t)); 1056 if (!retval) 1057 goto end; 1058 1059 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen 1060 + sizeof(sctp_paramhdr_t)); 1061 1062 phdr.type = htons(chunk->chunk_hdr->type); 1063 phdr.length = chunk->chunk_hdr->length; 1064 sctp_addto_chunk(retval, paylen, payload); 1065 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr); 1066 1067 end: 1068 return retval; 1069 } 1070 1071 struct sctp_chunk *sctp_make_violation_paramlen( 1072 const struct sctp_association *asoc, 1073 const struct sctp_chunk *chunk, 1074 struct sctp_paramhdr *param) 1075 { 1076 struct sctp_chunk *retval; 1077 static const char error[] = "The following parameter had invalid length:"; 1078 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t) + 1079 sizeof(sctp_paramhdr_t); 1080 1081 retval = sctp_make_abort(asoc, chunk, payload_len); 1082 if (!retval) 1083 goto nodata; 1084 1085 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, 1086 sizeof(error) + sizeof(sctp_paramhdr_t)); 1087 sctp_addto_chunk(retval, sizeof(error), error); 1088 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), param); 1089 1090 nodata: 1091 return retval; 1092 } 1093 1094 struct sctp_chunk *sctp_make_violation_max_retrans( 1095 const struct sctp_association *asoc, 1096 const struct sctp_chunk *chunk) 1097 { 1098 struct sctp_chunk *retval; 1099 static const char error[] = "Association exceeded its max_retans count"; 1100 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t); 1101 1102 retval = sctp_make_abort(asoc, chunk, payload_len); 1103 if (!retval) 1104 goto nodata; 1105 1106 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error)); 1107 sctp_addto_chunk(retval, sizeof(error), error); 1108 1109 nodata: 1110 return retval; 1111 } 1112 1113 /* Make a HEARTBEAT chunk. */ 1114 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1115 const struct sctp_transport *transport) 1116 { 1117 struct sctp_chunk *retval; 1118 sctp_sender_hb_info_t hbinfo; 1119 1120 retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT, 0, sizeof(hbinfo)); 1121 1122 if (!retval) 1123 goto nodata; 1124 1125 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; 1126 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t)); 1127 hbinfo.daddr = transport->ipaddr; 1128 hbinfo.sent_at = jiffies; 1129 hbinfo.hb_nonce = transport->hb_nonce; 1130 1131 /* Cast away the 'const', as this is just telling the chunk 1132 * what transport it belongs to. 1133 */ 1134 retval->transport = (struct sctp_transport *) transport; 1135 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo), 1136 &hbinfo); 1137 1138 nodata: 1139 return retval; 1140 } 1141 1142 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1143 const struct sctp_chunk *chunk, 1144 const void *payload, const size_t paylen) 1145 { 1146 struct sctp_chunk *retval; 1147 1148 retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen); 1149 if (!retval) 1150 goto nodata; 1151 1152 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1153 1154 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1155 * 1156 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1157 * HEARTBEAT ACK, * etc.) to the same destination transport 1158 * address from which it * received the DATA or control chunk 1159 * to which it is replying. 1160 * 1161 * [HBACK back to where the HEARTBEAT came from.] 1162 */ 1163 if (chunk) 1164 retval->transport = chunk->transport; 1165 1166 nodata: 1167 return retval; 1168 } 1169 1170 /* Create an Operation Error chunk with the specified space reserved. 1171 * This routine can be used for containing multiple causes in the chunk. 1172 */ 1173 static struct sctp_chunk *sctp_make_op_error_space( 1174 const struct sctp_association *asoc, 1175 const struct sctp_chunk *chunk, 1176 size_t size) 1177 { 1178 struct sctp_chunk *retval; 1179 1180 retval = sctp_make_chunk(asoc, SCTP_CID_ERROR, 0, 1181 sizeof(sctp_errhdr_t) + size); 1182 if (!retval) 1183 goto nodata; 1184 1185 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1186 * 1187 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1188 * HEARTBEAT ACK, etc.) to the same destination transport 1189 * address from which it received the DATA or control chunk 1190 * to which it is replying. 1191 * 1192 */ 1193 if (chunk) 1194 retval->transport = chunk->transport; 1195 1196 nodata: 1197 return retval; 1198 } 1199 1200 /* Create an Operation Error chunk of a fixed size, 1201 * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) 1202 * This is a helper function to allocate an error chunk for 1203 * for those invalid parameter codes in which we may not want 1204 * to report all the errors, if the incomming chunk is large 1205 */ 1206 static inline struct sctp_chunk *sctp_make_op_error_fixed( 1207 const struct sctp_association *asoc, 1208 const struct sctp_chunk *chunk) 1209 { 1210 size_t size = asoc ? asoc->pathmtu : 0; 1211 1212 if (!size) 1213 size = SCTP_DEFAULT_MAXSEGMENT; 1214 1215 return sctp_make_op_error_space(asoc, chunk, size); 1216 } 1217 1218 /* Create an Operation Error chunk. */ 1219 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1220 const struct sctp_chunk *chunk, 1221 __be16 cause_code, const void *payload, 1222 size_t paylen, size_t reserve_tail) 1223 { 1224 struct sctp_chunk *retval; 1225 1226 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); 1227 if (!retval) 1228 goto nodata; 1229 1230 sctp_init_cause(retval, cause_code, paylen + reserve_tail); 1231 sctp_addto_chunk(retval, paylen, payload); 1232 if (reserve_tail) 1233 sctp_addto_param(retval, reserve_tail, NULL); 1234 1235 nodata: 1236 return retval; 1237 } 1238 1239 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc) 1240 { 1241 struct sctp_chunk *retval; 1242 struct sctp_hmac *hmac_desc; 1243 struct sctp_authhdr auth_hdr; 1244 __u8 *hmac; 1245 1246 /* Get the first hmac that the peer told us to use */ 1247 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1248 if (unlikely(!hmac_desc)) 1249 return NULL; 1250 1251 retval = sctp_make_chunk(asoc, SCTP_CID_AUTH, 0, 1252 hmac_desc->hmac_len + sizeof(sctp_authhdr_t)); 1253 if (!retval) 1254 return NULL; 1255 1256 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1257 auth_hdr.shkey_id = htons(asoc->active_key_id); 1258 1259 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t), 1260 &auth_hdr); 1261 1262 hmac = skb_put(retval->skb, hmac_desc->hmac_len); 1263 memset(hmac, 0, hmac_desc->hmac_len); 1264 1265 /* Adjust the chunk header to include the empty MAC */ 1266 retval->chunk_hdr->length = 1267 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1268 retval->chunk_end = skb_tail_pointer(retval->skb); 1269 1270 return retval; 1271 } 1272 1273 1274 /******************************************************************** 1275 * 2nd Level Abstractions 1276 ********************************************************************/ 1277 1278 /* Turn an skb into a chunk. 1279 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1280 */ 1281 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1282 const struct sctp_association *asoc, 1283 struct sock *sk) 1284 { 1285 struct sctp_chunk *retval; 1286 1287 retval = kmem_cache_zalloc(sctp_chunk_cachep, GFP_ATOMIC); 1288 1289 if (!retval) 1290 goto nodata; 1291 1292 if (!sk) { 1293 SCTP_DEBUG_PRINTK("chunkifying skb %p w/o an sk\n", skb); 1294 } 1295 1296 INIT_LIST_HEAD(&retval->list); 1297 retval->skb = skb; 1298 retval->asoc = (struct sctp_association *)asoc; 1299 retval->has_tsn = 0; 1300 retval->has_ssn = 0; 1301 retval->rtt_in_progress = 0; 1302 retval->sent_at = 0; 1303 retval->singleton = 1; 1304 retval->end_of_packet = 0; 1305 retval->ecn_ce_done = 0; 1306 retval->pdiscard = 0; 1307 1308 /* sctpimpguide-05.txt Section 2.8.2 1309 * M1) Each time a new DATA chunk is transmitted 1310 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1311 * 'TSN.Missing.Report' count will be used to determine missing chunks 1312 * and when to fast retransmit. 1313 */ 1314 retval->tsn_missing_report = 0; 1315 retval->tsn_gap_acked = 0; 1316 retval->fast_retransmit = SCTP_CAN_FRTX; 1317 1318 /* If this is a fragmented message, track all fragments 1319 * of the message (for SEND_FAILED). 1320 */ 1321 retval->msg = NULL; 1322 1323 /* Polish the bead hole. */ 1324 INIT_LIST_HEAD(&retval->transmitted_list); 1325 INIT_LIST_HEAD(&retval->frag_list); 1326 SCTP_DBG_OBJCNT_INC(chunk); 1327 atomic_set(&retval->refcnt, 1); 1328 1329 nodata: 1330 return retval; 1331 } 1332 1333 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1334 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1335 union sctp_addr *dest) 1336 { 1337 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1338 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1339 } 1340 1341 /* Extract the source address from a chunk. */ 1342 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1343 { 1344 /* If we have a known transport, use that. */ 1345 if (chunk->transport) { 1346 return &chunk->transport->ipaddr; 1347 } else { 1348 /* Otherwise, extract it from the IP header. */ 1349 return &chunk->source; 1350 } 1351 } 1352 1353 /* Create a new chunk, setting the type and flags headers from the 1354 * arguments, reserving enough space for a 'paylen' byte payload. 1355 */ 1356 SCTP_STATIC 1357 struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc, 1358 __u8 type, __u8 flags, int paylen) 1359 { 1360 struct sctp_chunk *retval; 1361 sctp_chunkhdr_t *chunk_hdr; 1362 struct sk_buff *skb; 1363 struct sock *sk; 1364 1365 /* No need to allocate LL here, as this is only a chunk. */ 1366 skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen), 1367 GFP_ATOMIC); 1368 if (!skb) 1369 goto nodata; 1370 1371 /* Make room for the chunk header. */ 1372 chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t)); 1373 chunk_hdr->type = type; 1374 chunk_hdr->flags = flags; 1375 chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t)); 1376 1377 sk = asoc ? asoc->base.sk : NULL; 1378 retval = sctp_chunkify(skb, asoc, sk); 1379 if (!retval) { 1380 kfree_skb(skb); 1381 goto nodata; 1382 } 1383 1384 retval->chunk_hdr = chunk_hdr; 1385 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr); 1386 1387 /* Determine if the chunk needs to be authenticated */ 1388 if (sctp_auth_send_cid(type, asoc)) 1389 retval->auth = 1; 1390 1391 /* Set the skb to the belonging sock for accounting. */ 1392 skb->sk = sk; 1393 1394 return retval; 1395 nodata: 1396 return NULL; 1397 } 1398 1399 1400 /* Release the memory occupied by a chunk. */ 1401 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1402 { 1403 BUG_ON(!list_empty(&chunk->list)); 1404 list_del_init(&chunk->transmitted_list); 1405 1406 /* Free the chunk skb data and the SCTP_chunk stub itself. */ 1407 dev_kfree_skb(chunk->skb); 1408 1409 SCTP_DBG_OBJCNT_DEC(chunk); 1410 kmem_cache_free(sctp_chunk_cachep, chunk); 1411 } 1412 1413 /* Possibly, free the chunk. */ 1414 void sctp_chunk_free(struct sctp_chunk *chunk) 1415 { 1416 /* Release our reference on the message tracker. */ 1417 if (chunk->msg) 1418 sctp_datamsg_put(chunk->msg); 1419 1420 sctp_chunk_put(chunk); 1421 } 1422 1423 /* Grab a reference to the chunk. */ 1424 void sctp_chunk_hold(struct sctp_chunk *ch) 1425 { 1426 atomic_inc(&ch->refcnt); 1427 } 1428 1429 /* Release a reference to the chunk. */ 1430 void sctp_chunk_put(struct sctp_chunk *ch) 1431 { 1432 if (atomic_dec_and_test(&ch->refcnt)) 1433 sctp_chunk_destroy(ch); 1434 } 1435 1436 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1437 * enough. 1438 */ 1439 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1440 { 1441 void *target; 1442 void *padding; 1443 int chunklen = ntohs(chunk->chunk_hdr->length); 1444 int padlen = WORD_ROUND(chunklen) - chunklen; 1445 1446 padding = skb_put(chunk->skb, padlen); 1447 target = skb_put(chunk->skb, len); 1448 1449 memset(padding, 0, padlen); 1450 memcpy(target, data, len); 1451 1452 /* Adjust the chunk length field. */ 1453 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1454 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1455 1456 return target; 1457 } 1458 1459 /* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient 1460 * space in the chunk 1461 */ 1462 void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk, 1463 int len, const void *data) 1464 { 1465 if (skb_tailroom(chunk->skb) >= len) 1466 return sctp_addto_chunk(chunk, len, data); 1467 else 1468 return NULL; 1469 } 1470 1471 /* Append bytes from user space to the end of a chunk. Will panic if 1472 * chunk is not big enough. 1473 * Returns a kernel err value. 1474 */ 1475 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len, 1476 struct iovec *data) 1477 { 1478 __u8 *target; 1479 int err = 0; 1480 1481 /* Make room in chunk for data. */ 1482 target = skb_put(chunk->skb, len); 1483 1484 /* Copy data (whole iovec) into chunk */ 1485 if ((err = memcpy_fromiovecend(target, data, off, len))) 1486 goto out; 1487 1488 /* Adjust the chunk length field. */ 1489 chunk->chunk_hdr->length = 1490 htons(ntohs(chunk->chunk_hdr->length) + len); 1491 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1492 1493 out: 1494 return err; 1495 } 1496 1497 /* Helper function to assign a TSN if needed. This assumes that both 1498 * the data_hdr and association have already been assigned. 1499 */ 1500 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1501 { 1502 struct sctp_datamsg *msg; 1503 struct sctp_chunk *lchunk; 1504 struct sctp_stream *stream; 1505 __u16 ssn; 1506 __u16 sid; 1507 1508 if (chunk->has_ssn) 1509 return; 1510 1511 /* All fragments will be on the same stream */ 1512 sid = ntohs(chunk->subh.data_hdr->stream); 1513 stream = &chunk->asoc->ssnmap->out; 1514 1515 /* Now assign the sequence number to the entire message. 1516 * All fragments must have the same stream sequence number. 1517 */ 1518 msg = chunk->msg; 1519 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1520 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1521 ssn = 0; 1522 } else { 1523 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1524 ssn = sctp_ssn_next(stream, sid); 1525 else 1526 ssn = sctp_ssn_peek(stream, sid); 1527 } 1528 1529 lchunk->subh.data_hdr->ssn = htons(ssn); 1530 lchunk->has_ssn = 1; 1531 } 1532 } 1533 1534 /* Helper function to assign a TSN if needed. This assumes that both 1535 * the data_hdr and association have already been assigned. 1536 */ 1537 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1538 { 1539 if (!chunk->has_tsn) { 1540 /* This is the last possible instant to 1541 * assign a TSN. 1542 */ 1543 chunk->subh.data_hdr->tsn = 1544 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1545 chunk->has_tsn = 1; 1546 } 1547 } 1548 1549 /* Create a CLOSED association to use with an incoming packet. */ 1550 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1551 struct sctp_chunk *chunk, 1552 gfp_t gfp) 1553 { 1554 struct sctp_association *asoc; 1555 struct sk_buff *skb; 1556 sctp_scope_t scope; 1557 struct sctp_af *af; 1558 1559 /* Create the bare association. */ 1560 scope = sctp_scope(sctp_source(chunk)); 1561 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1562 if (!asoc) 1563 goto nodata; 1564 asoc->temp = 1; 1565 skb = chunk->skb; 1566 /* Create an entry for the source address of the packet. */ 1567 af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version)); 1568 if (unlikely(!af)) 1569 goto fail; 1570 af->from_skb(&asoc->c.peer_addr, skb, 1); 1571 nodata: 1572 return asoc; 1573 1574 fail: 1575 sctp_association_free(asoc); 1576 return NULL; 1577 } 1578 1579 /* Build a cookie representing asoc. 1580 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1581 */ 1582 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, 1583 const struct sctp_association *asoc, 1584 const struct sctp_chunk *init_chunk, 1585 int *cookie_len, 1586 const __u8 *raw_addrs, int addrs_len) 1587 { 1588 sctp_cookie_param_t *retval; 1589 struct sctp_signed_cookie *cookie; 1590 struct scatterlist sg; 1591 int headersize, bodysize; 1592 1593 /* Header size is static data prior to the actual cookie, including 1594 * any padding. 1595 */ 1596 headersize = sizeof(sctp_paramhdr_t) + 1597 (sizeof(struct sctp_signed_cookie) - 1598 sizeof(struct sctp_cookie)); 1599 bodysize = sizeof(struct sctp_cookie) 1600 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1601 1602 /* Pad out the cookie to a multiple to make the signature 1603 * functions simpler to write. 1604 */ 1605 if (bodysize % SCTP_COOKIE_MULTIPLE) 1606 bodysize += SCTP_COOKIE_MULTIPLE 1607 - (bodysize % SCTP_COOKIE_MULTIPLE); 1608 *cookie_len = headersize + bodysize; 1609 1610 /* Clear this memory since we are sending this data structure 1611 * out on the network. 1612 */ 1613 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1614 if (!retval) 1615 goto nodata; 1616 1617 cookie = (struct sctp_signed_cookie *) retval->body; 1618 1619 /* Set up the parameter header. */ 1620 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1621 retval->p.length = htons(*cookie_len); 1622 1623 /* Copy the cookie part of the association itself. */ 1624 cookie->c = asoc->c; 1625 /* Save the raw address list length in the cookie. */ 1626 cookie->c.raw_addr_list_len = addrs_len; 1627 1628 /* Remember PR-SCTP capability. */ 1629 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1630 1631 /* Save adaptation indication in the cookie. */ 1632 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1633 1634 /* Set an expiration time for the cookie. */ 1635 do_gettimeofday(&cookie->c.expiration); 1636 TIMEVAL_ADD(asoc->cookie_life, cookie->c.expiration); 1637 1638 /* Copy the peer's init packet. */ 1639 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr, 1640 ntohs(init_chunk->chunk_hdr->length)); 1641 1642 /* Copy the raw local address list of the association. */ 1643 memcpy((__u8 *)&cookie->c.peer_init[0] + 1644 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1645 1646 if (sctp_sk(ep->base.sk)->hmac) { 1647 struct hash_desc desc; 1648 1649 /* Sign the message. */ 1650 sg_init_one(&sg, &cookie->c, bodysize); 1651 desc.tfm = sctp_sk(ep->base.sk)->hmac; 1652 desc.flags = 0; 1653 1654 if (crypto_hash_setkey(desc.tfm, ep->secret_key, 1655 sizeof(ep->secret_key)) || 1656 crypto_hash_digest(&desc, &sg, bodysize, cookie->signature)) 1657 goto free_cookie; 1658 } 1659 1660 return retval; 1661 1662 free_cookie: 1663 kfree(retval); 1664 nodata: 1665 *cookie_len = 0; 1666 return NULL; 1667 } 1668 1669 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1670 struct sctp_association *sctp_unpack_cookie( 1671 const struct sctp_endpoint *ep, 1672 const struct sctp_association *asoc, 1673 struct sctp_chunk *chunk, gfp_t gfp, 1674 int *error, struct sctp_chunk **errp) 1675 { 1676 struct sctp_association *retval = NULL; 1677 struct sctp_signed_cookie *cookie; 1678 struct sctp_cookie *bear_cookie; 1679 int headersize, bodysize, fixed_size; 1680 __u8 *digest = ep->digest; 1681 struct scatterlist sg; 1682 unsigned int len; 1683 sctp_scope_t scope; 1684 struct sk_buff *skb = chunk->skb; 1685 struct timeval tv; 1686 struct hash_desc desc; 1687 1688 /* Header size is static data prior to the actual cookie, including 1689 * any padding. 1690 */ 1691 headersize = sizeof(sctp_chunkhdr_t) + 1692 (sizeof(struct sctp_signed_cookie) - 1693 sizeof(struct sctp_cookie)); 1694 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1695 fixed_size = headersize + sizeof(struct sctp_cookie); 1696 1697 /* Verify that the chunk looks like it even has a cookie. 1698 * There must be enough room for our cookie and our peer's 1699 * INIT chunk. 1700 */ 1701 len = ntohs(chunk->chunk_hdr->length); 1702 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1703 goto malformed; 1704 1705 /* Verify that the cookie has been padded out. */ 1706 if (bodysize % SCTP_COOKIE_MULTIPLE) 1707 goto malformed; 1708 1709 /* Process the cookie. */ 1710 cookie = chunk->subh.cookie_hdr; 1711 bear_cookie = &cookie->c; 1712 1713 if (!sctp_sk(ep->base.sk)->hmac) 1714 goto no_hmac; 1715 1716 /* Check the signature. */ 1717 sg_init_one(&sg, bear_cookie, bodysize); 1718 desc.tfm = sctp_sk(ep->base.sk)->hmac; 1719 desc.flags = 0; 1720 1721 memset(digest, 0x00, SCTP_SIGNATURE_SIZE); 1722 if (crypto_hash_setkey(desc.tfm, ep->secret_key, 1723 sizeof(ep->secret_key)) || 1724 crypto_hash_digest(&desc, &sg, bodysize, digest)) { 1725 *error = -SCTP_IERROR_NOMEM; 1726 goto fail; 1727 } 1728 1729 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1730 *error = -SCTP_IERROR_BAD_SIG; 1731 goto fail; 1732 } 1733 1734 no_hmac: 1735 /* IG Section 2.35.2: 1736 * 3) Compare the port numbers and the verification tag contained 1737 * within the COOKIE ECHO chunk to the actual port numbers and the 1738 * verification tag within the SCTP common header of the received 1739 * packet. If these values do not match the packet MUST be silently 1740 * discarded, 1741 */ 1742 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1743 *error = -SCTP_IERROR_BAD_TAG; 1744 goto fail; 1745 } 1746 1747 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1748 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1749 *error = -SCTP_IERROR_BAD_PORTS; 1750 goto fail; 1751 } 1752 1753 /* Check to see if the cookie is stale. If there is already 1754 * an association, there is no need to check cookie's expiration 1755 * for init collision case of lost COOKIE ACK. 1756 * If skb has been timestamped, then use the stamp, otherwise 1757 * use current time. This introduces a small possibility that 1758 * that a cookie may be considered expired, but his would only slow 1759 * down the new association establishment instead of every packet. 1760 */ 1761 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1762 skb_get_timestamp(skb, &tv); 1763 else 1764 do_gettimeofday(&tv); 1765 1766 if (!asoc && tv_lt(bear_cookie->expiration, tv)) { 1767 /* 1768 * Section 3.3.10.3 Stale Cookie Error (3) 1769 * 1770 * Cause of error 1771 * --------------- 1772 * Stale Cookie Error: Indicates the receipt of a valid State 1773 * Cookie that has expired. 1774 */ 1775 len = ntohs(chunk->chunk_hdr->length); 1776 *errp = sctp_make_op_error_space(asoc, chunk, len); 1777 if (*errp) { 1778 suseconds_t usecs = (tv.tv_sec - 1779 bear_cookie->expiration.tv_sec) * 1000000L + 1780 tv.tv_usec - bear_cookie->expiration.tv_usec; 1781 __be32 n = htonl(usecs); 1782 1783 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE, 1784 sizeof(n)); 1785 sctp_addto_chunk(*errp, sizeof(n), &n); 1786 *error = -SCTP_IERROR_STALE_COOKIE; 1787 } else 1788 *error = -SCTP_IERROR_NOMEM; 1789 1790 goto fail; 1791 } 1792 1793 /* Make a new base association. */ 1794 scope = sctp_scope(sctp_source(chunk)); 1795 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1796 if (!retval) { 1797 *error = -SCTP_IERROR_NOMEM; 1798 goto fail; 1799 } 1800 1801 /* Set up our peer's port number. */ 1802 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1803 1804 /* Populate the association from the cookie. */ 1805 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1806 1807 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1808 GFP_ATOMIC) < 0) { 1809 *error = -SCTP_IERROR_NOMEM; 1810 goto fail; 1811 } 1812 1813 /* Also, add the destination address. */ 1814 if (list_empty(&retval->base.bind_addr.address_list)) { 1815 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1816 SCTP_ADDR_SRC, GFP_ATOMIC); 1817 } 1818 1819 retval->next_tsn = retval->c.initial_tsn; 1820 retval->ctsn_ack_point = retval->next_tsn - 1; 1821 retval->addip_serial = retval->c.initial_tsn; 1822 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1823 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1824 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1825 1826 /* The INIT stuff will be done by the side effects. */ 1827 return retval; 1828 1829 fail: 1830 if (retval) 1831 sctp_association_free(retval); 1832 1833 return NULL; 1834 1835 malformed: 1836 /* Yikes! The packet is either corrupt or deliberately 1837 * malformed. 1838 */ 1839 *error = -SCTP_IERROR_MALFORMED; 1840 goto fail; 1841 } 1842 1843 /******************************************************************** 1844 * 3rd Level Abstractions 1845 ********************************************************************/ 1846 1847 struct __sctp_missing { 1848 __be32 num_missing; 1849 __be16 type; 1850 } __packed; 1851 1852 /* 1853 * Report a missing mandatory parameter. 1854 */ 1855 static int sctp_process_missing_param(const struct sctp_association *asoc, 1856 sctp_param_t paramtype, 1857 struct sctp_chunk *chunk, 1858 struct sctp_chunk **errp) 1859 { 1860 struct __sctp_missing report; 1861 __u16 len; 1862 1863 len = WORD_ROUND(sizeof(report)); 1864 1865 /* Make an ERROR chunk, preparing enough room for 1866 * returning multiple unknown parameters. 1867 */ 1868 if (!*errp) 1869 *errp = sctp_make_op_error_space(asoc, chunk, len); 1870 1871 if (*errp) { 1872 report.num_missing = htonl(1); 1873 report.type = paramtype; 1874 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1875 sizeof(report)); 1876 sctp_addto_chunk(*errp, sizeof(report), &report); 1877 } 1878 1879 /* Stop processing this chunk. */ 1880 return 0; 1881 } 1882 1883 /* Report an Invalid Mandatory Parameter. */ 1884 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1885 struct sctp_chunk *chunk, 1886 struct sctp_chunk **errp) 1887 { 1888 /* Invalid Mandatory Parameter Error has no payload. */ 1889 1890 if (!*errp) 1891 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1892 1893 if (*errp) 1894 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1895 1896 /* Stop processing this chunk. */ 1897 return 0; 1898 } 1899 1900 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1901 struct sctp_paramhdr *param, 1902 const struct sctp_chunk *chunk, 1903 struct sctp_chunk **errp) 1904 { 1905 /* This is a fatal error. Any accumulated non-fatal errors are 1906 * not reported. 1907 */ 1908 if (*errp) 1909 sctp_chunk_free(*errp); 1910 1911 /* Create an error chunk and fill it in with our payload. */ 1912 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1913 1914 return 0; 1915 } 1916 1917 1918 /* Do not attempt to handle the HOST_NAME parm. However, do 1919 * send back an indicator to the peer. 1920 */ 1921 static int sctp_process_hn_param(const struct sctp_association *asoc, 1922 union sctp_params param, 1923 struct sctp_chunk *chunk, 1924 struct sctp_chunk **errp) 1925 { 1926 __u16 len = ntohs(param.p->length); 1927 1928 /* Processing of the HOST_NAME parameter will generate an 1929 * ABORT. If we've accumulated any non-fatal errors, they 1930 * would be unrecognized parameters and we should not include 1931 * them in the ABORT. 1932 */ 1933 if (*errp) 1934 sctp_chunk_free(*errp); 1935 1936 *errp = sctp_make_op_error_space(asoc, chunk, len); 1937 1938 if (*errp) { 1939 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len); 1940 sctp_addto_chunk(*errp, len, param.v); 1941 } 1942 1943 /* Stop processing this chunk. */ 1944 return 0; 1945 } 1946 1947 static int sctp_verify_ext_param(struct net *net, union sctp_params param) 1948 { 1949 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 1950 int have_auth = 0; 1951 int have_asconf = 0; 1952 int i; 1953 1954 for (i = 0; i < num_ext; i++) { 1955 switch (param.ext->chunks[i]) { 1956 case SCTP_CID_AUTH: 1957 have_auth = 1; 1958 break; 1959 case SCTP_CID_ASCONF: 1960 case SCTP_CID_ASCONF_ACK: 1961 have_asconf = 1; 1962 break; 1963 } 1964 } 1965 1966 /* ADD-IP Security: The draft requires us to ABORT or ignore the 1967 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 1968 * only if ADD-IP is turned on and we are not backward-compatible 1969 * mode. 1970 */ 1971 if (net->sctp.addip_noauth) 1972 return 1; 1973 1974 if (net->sctp.addip_enable && !have_auth && have_asconf) 1975 return 0; 1976 1977 return 1; 1978 } 1979 1980 static void sctp_process_ext_param(struct sctp_association *asoc, 1981 union sctp_params param) 1982 { 1983 struct net *net = sock_net(asoc->base.sk); 1984 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 1985 int i; 1986 1987 for (i = 0; i < num_ext; i++) { 1988 switch (param.ext->chunks[i]) { 1989 case SCTP_CID_FWD_TSN: 1990 if (net->sctp.prsctp_enable && 1991 !asoc->peer.prsctp_capable) 1992 asoc->peer.prsctp_capable = 1; 1993 break; 1994 case SCTP_CID_AUTH: 1995 /* if the peer reports AUTH, assume that he 1996 * supports AUTH. 1997 */ 1998 if (net->sctp.auth_enable) 1999 asoc->peer.auth_capable = 1; 2000 break; 2001 case SCTP_CID_ASCONF: 2002 case SCTP_CID_ASCONF_ACK: 2003 if (net->sctp.addip_enable) 2004 asoc->peer.asconf_capable = 1; 2005 break; 2006 default: 2007 break; 2008 } 2009 } 2010 } 2011 2012 /* RFC 3.2.1 & the Implementers Guide 2.2. 2013 * 2014 * The Parameter Types are encoded such that the 2015 * highest-order two bits specify the action that must be 2016 * taken if the processing endpoint does not recognize the 2017 * Parameter Type. 2018 * 2019 * 00 - Stop processing this parameter; do not process any further 2020 * parameters within this chunk 2021 * 2022 * 01 - Stop processing this parameter, do not process any further 2023 * parameters within this chunk, and report the unrecognized 2024 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2025 * 2026 * 10 - Skip this parameter and continue processing. 2027 * 2028 * 11 - Skip this parameter and continue processing but 2029 * report the unrecognized parameter in an 2030 * 'Unrecognized Parameter' ERROR chunk. 2031 * 2032 * Return value: 2033 * SCTP_IERROR_NO_ERROR - continue with the chunk 2034 * SCTP_IERROR_ERROR - stop and report an error. 2035 * SCTP_IERROR_NOMEME - out of memory. 2036 */ 2037 static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc, 2038 union sctp_params param, 2039 struct sctp_chunk *chunk, 2040 struct sctp_chunk **errp) 2041 { 2042 int retval = SCTP_IERROR_NO_ERROR; 2043 2044 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2045 case SCTP_PARAM_ACTION_DISCARD: 2046 retval = SCTP_IERROR_ERROR; 2047 break; 2048 case SCTP_PARAM_ACTION_SKIP: 2049 break; 2050 case SCTP_PARAM_ACTION_DISCARD_ERR: 2051 retval = SCTP_IERROR_ERROR; 2052 /* Fall through */ 2053 case SCTP_PARAM_ACTION_SKIP_ERR: 2054 /* Make an ERROR chunk, preparing enough room for 2055 * returning multiple unknown parameters. 2056 */ 2057 if (NULL == *errp) 2058 *errp = sctp_make_op_error_fixed(asoc, chunk); 2059 2060 if (*errp) { 2061 if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2062 WORD_ROUND(ntohs(param.p->length)))) 2063 sctp_addto_chunk_fixed(*errp, 2064 WORD_ROUND(ntohs(param.p->length)), 2065 param.v); 2066 } else { 2067 /* If there is no memory for generating the ERROR 2068 * report as specified, an ABORT will be triggered 2069 * to the peer and the association won't be 2070 * established. 2071 */ 2072 retval = SCTP_IERROR_NOMEM; 2073 } 2074 break; 2075 default: 2076 break; 2077 } 2078 2079 return retval; 2080 } 2081 2082 /* Verify variable length parameters 2083 * Return values: 2084 * SCTP_IERROR_ABORT - trigger an ABORT 2085 * SCTP_IERROR_NOMEM - out of memory (abort) 2086 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2087 * SCTP_IERROR_NO_ERROR - continue with the chunk 2088 */ 2089 static sctp_ierror_t sctp_verify_param(struct net *net, 2090 const struct sctp_association *asoc, 2091 union sctp_params param, 2092 sctp_cid_t cid, 2093 struct sctp_chunk *chunk, 2094 struct sctp_chunk **err_chunk) 2095 { 2096 struct sctp_hmac_algo_param *hmacs; 2097 int retval = SCTP_IERROR_NO_ERROR; 2098 __u16 n_elt, id = 0; 2099 int i; 2100 2101 /* FIXME - This routine is not looking at each parameter per the 2102 * chunk type, i.e., unrecognized parameters should be further 2103 * identified based on the chunk id. 2104 */ 2105 2106 switch (param.p->type) { 2107 case SCTP_PARAM_IPV4_ADDRESS: 2108 case SCTP_PARAM_IPV6_ADDRESS: 2109 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2110 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2111 case SCTP_PARAM_STATE_COOKIE: 2112 case SCTP_PARAM_HEARTBEAT_INFO: 2113 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2114 case SCTP_PARAM_ECN_CAPABLE: 2115 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2116 break; 2117 2118 case SCTP_PARAM_SUPPORTED_EXT: 2119 if (!sctp_verify_ext_param(net, param)) 2120 return SCTP_IERROR_ABORT; 2121 break; 2122 2123 case SCTP_PARAM_SET_PRIMARY: 2124 if (net->sctp.addip_enable) 2125 break; 2126 goto fallthrough; 2127 2128 case SCTP_PARAM_HOST_NAME_ADDRESS: 2129 /* Tell the peer, we won't support this param. */ 2130 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2131 retval = SCTP_IERROR_ABORT; 2132 break; 2133 2134 case SCTP_PARAM_FWD_TSN_SUPPORT: 2135 if (net->sctp.prsctp_enable) 2136 break; 2137 goto fallthrough; 2138 2139 case SCTP_PARAM_RANDOM: 2140 if (!net->sctp.auth_enable) 2141 goto fallthrough; 2142 2143 /* SCTP-AUTH: Secion 6.1 2144 * If the random number is not 32 byte long the association 2145 * MUST be aborted. The ABORT chunk SHOULD contain the error 2146 * cause 'Protocol Violation'. 2147 */ 2148 if (SCTP_AUTH_RANDOM_LENGTH != 2149 ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) { 2150 sctp_process_inv_paramlength(asoc, param.p, 2151 chunk, err_chunk); 2152 retval = SCTP_IERROR_ABORT; 2153 } 2154 break; 2155 2156 case SCTP_PARAM_CHUNKS: 2157 if (!net->sctp.auth_enable) 2158 goto fallthrough; 2159 2160 /* SCTP-AUTH: Section 3.2 2161 * The CHUNKS parameter MUST be included once in the INIT or 2162 * INIT-ACK chunk if the sender wants to receive authenticated 2163 * chunks. Its maximum length is 260 bytes. 2164 */ 2165 if (260 < ntohs(param.p->length)) { 2166 sctp_process_inv_paramlength(asoc, param.p, 2167 chunk, err_chunk); 2168 retval = SCTP_IERROR_ABORT; 2169 } 2170 break; 2171 2172 case SCTP_PARAM_HMAC_ALGO: 2173 if (!net->sctp.auth_enable) 2174 goto fallthrough; 2175 2176 hmacs = (struct sctp_hmac_algo_param *)param.p; 2177 n_elt = (ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) >> 1; 2178 2179 /* SCTP-AUTH: Section 6.1 2180 * The HMAC algorithm based on SHA-1 MUST be supported and 2181 * included in the HMAC-ALGO parameter. 2182 */ 2183 for (i = 0; i < n_elt; i++) { 2184 id = ntohs(hmacs->hmac_ids[i]); 2185 2186 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2187 break; 2188 } 2189 2190 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2191 sctp_process_inv_paramlength(asoc, param.p, chunk, 2192 err_chunk); 2193 retval = SCTP_IERROR_ABORT; 2194 } 2195 break; 2196 fallthrough: 2197 default: 2198 SCTP_DEBUG_PRINTK("Unrecognized param: %d for chunk %d.\n", 2199 ntohs(param.p->type), cid); 2200 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2201 break; 2202 } 2203 return retval; 2204 } 2205 2206 /* Verify the INIT packet before we process it. */ 2207 int sctp_verify_init(struct net *net, const struct sctp_association *asoc, 2208 sctp_cid_t cid, 2209 sctp_init_chunk_t *peer_init, 2210 struct sctp_chunk *chunk, 2211 struct sctp_chunk **errp) 2212 { 2213 union sctp_params param; 2214 int has_cookie = 0; 2215 int result; 2216 2217 /* Verify stream values are non-zero. */ 2218 if ((0 == peer_init->init_hdr.num_outbound_streams) || 2219 (0 == peer_init->init_hdr.num_inbound_streams) || 2220 (0 == peer_init->init_hdr.init_tag) || 2221 (SCTP_DEFAULT_MINWINDOW > ntohl(peer_init->init_hdr.a_rwnd))) { 2222 2223 return sctp_process_inv_mandatory(asoc, chunk, errp); 2224 } 2225 2226 /* Check for missing mandatory parameters. */ 2227 sctp_walk_params(param, peer_init, init_hdr.params) { 2228 2229 if (SCTP_PARAM_STATE_COOKIE == param.p->type) 2230 has_cookie = 1; 2231 2232 } /* for (loop through all parameters) */ 2233 2234 /* There is a possibility that a parameter length was bad and 2235 * in that case we would have stoped walking the parameters. 2236 * The current param.p would point at the bad one. 2237 * Current consensus on the mailing list is to generate a PROTOCOL 2238 * VIOLATION error. We build the ERROR chunk here and let the normal 2239 * error handling code build and send the packet. 2240 */ 2241 if (param.v != (void*)chunk->chunk_end) 2242 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2243 2244 /* The only missing mandatory param possible today is 2245 * the state cookie for an INIT-ACK chunk. 2246 */ 2247 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2248 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2249 chunk, errp); 2250 2251 /* Verify all the variable length parameters */ 2252 sctp_walk_params(param, peer_init, init_hdr.params) { 2253 2254 result = sctp_verify_param(net, asoc, param, cid, chunk, errp); 2255 switch (result) { 2256 case SCTP_IERROR_ABORT: 2257 case SCTP_IERROR_NOMEM: 2258 return 0; 2259 case SCTP_IERROR_ERROR: 2260 return 1; 2261 case SCTP_IERROR_NO_ERROR: 2262 default: 2263 break; 2264 } 2265 2266 } /* for (loop through all parameters) */ 2267 2268 return 1; 2269 } 2270 2271 /* Unpack the parameters in an INIT packet into an association. 2272 * Returns 0 on failure, else success. 2273 * FIXME: This is an association method. 2274 */ 2275 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2276 const union sctp_addr *peer_addr, 2277 sctp_init_chunk_t *peer_init, gfp_t gfp) 2278 { 2279 struct net *net = sock_net(asoc->base.sk); 2280 union sctp_params param; 2281 struct sctp_transport *transport; 2282 struct list_head *pos, *temp; 2283 struct sctp_af *af; 2284 union sctp_addr addr; 2285 char *cookie; 2286 int src_match = 0; 2287 2288 /* We must include the address that the INIT packet came from. 2289 * This is the only address that matters for an INIT packet. 2290 * When processing a COOKIE ECHO, we retrieve the from address 2291 * of the INIT from the cookie. 2292 */ 2293 2294 /* This implementation defaults to making the first transport 2295 * added as the primary transport. The source address seems to 2296 * be a a better choice than any of the embedded addresses. 2297 */ 2298 if(!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2299 goto nomem; 2300 2301 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2302 src_match = 1; 2303 2304 /* Process the initialization parameters. */ 2305 sctp_walk_params(param, peer_init, init_hdr.params) { 2306 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2307 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2308 af = sctp_get_af_specific(param_type2af(param.p->type)); 2309 af->from_addr_param(&addr, param.addr, 2310 chunk->sctp_hdr->source, 0); 2311 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2312 src_match = 1; 2313 } 2314 2315 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2316 goto clean_up; 2317 } 2318 2319 /* source address of chunk may not match any valid address */ 2320 if (!src_match) 2321 goto clean_up; 2322 2323 /* AUTH: After processing the parameters, make sure that we 2324 * have all the required info to potentially do authentications. 2325 */ 2326 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2327 !asoc->peer.peer_hmacs)) 2328 asoc->peer.auth_capable = 0; 2329 2330 /* In a non-backward compatible mode, if the peer claims 2331 * support for ADD-IP but not AUTH, the ADD-IP spec states 2332 * that we MUST ABORT the association. Section 6. The section 2333 * also give us an option to silently ignore the packet, which 2334 * is what we'll do here. 2335 */ 2336 if (!net->sctp.addip_noauth && 2337 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2338 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2339 SCTP_PARAM_DEL_IP | 2340 SCTP_PARAM_SET_PRIMARY); 2341 asoc->peer.asconf_capable = 0; 2342 goto clean_up; 2343 } 2344 2345 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2346 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2347 transport = list_entry(pos, struct sctp_transport, transports); 2348 if (transport->state == SCTP_UNKNOWN) { 2349 sctp_assoc_rm_peer(asoc, transport); 2350 } 2351 } 2352 2353 /* The fixed INIT headers are always in network byte 2354 * order. 2355 */ 2356 asoc->peer.i.init_tag = 2357 ntohl(peer_init->init_hdr.init_tag); 2358 asoc->peer.i.a_rwnd = 2359 ntohl(peer_init->init_hdr.a_rwnd); 2360 asoc->peer.i.num_outbound_streams = 2361 ntohs(peer_init->init_hdr.num_outbound_streams); 2362 asoc->peer.i.num_inbound_streams = 2363 ntohs(peer_init->init_hdr.num_inbound_streams); 2364 asoc->peer.i.initial_tsn = 2365 ntohl(peer_init->init_hdr.initial_tsn); 2366 2367 /* Apply the upper bounds for output streams based on peer's 2368 * number of inbound streams. 2369 */ 2370 if (asoc->c.sinit_num_ostreams > 2371 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2372 asoc->c.sinit_num_ostreams = 2373 ntohs(peer_init->init_hdr.num_inbound_streams); 2374 } 2375 2376 if (asoc->c.sinit_max_instreams > 2377 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2378 asoc->c.sinit_max_instreams = 2379 ntohs(peer_init->init_hdr.num_outbound_streams); 2380 } 2381 2382 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2383 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2384 2385 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2386 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2387 2388 /* Copy cookie in case we need to resend COOKIE-ECHO. */ 2389 cookie = asoc->peer.cookie; 2390 if (cookie) { 2391 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp); 2392 if (!asoc->peer.cookie) 2393 goto clean_up; 2394 } 2395 2396 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2397 * high (for example, implementations MAY use the size of the receiver 2398 * advertised window). 2399 */ 2400 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2401 transports) { 2402 transport->ssthresh = asoc->peer.i.a_rwnd; 2403 } 2404 2405 /* Set up the TSN tracking pieces. */ 2406 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2407 asoc->peer.i.initial_tsn, gfp)) 2408 goto clean_up; 2409 2410 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2411 * 2412 * The stream sequence number in all the streams shall start 2413 * from 0 when the association is established. Also, when the 2414 * stream sequence number reaches the value 65535 the next 2415 * stream sequence number shall be set to 0. 2416 */ 2417 2418 /* Allocate storage for the negotiated streams if it is not a temporary 2419 * association. 2420 */ 2421 if (!asoc->temp) { 2422 int error; 2423 2424 asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams, 2425 asoc->c.sinit_num_ostreams, gfp); 2426 if (!asoc->ssnmap) 2427 goto clean_up; 2428 2429 error = sctp_assoc_set_id(asoc, gfp); 2430 if (error) 2431 goto clean_up; 2432 } 2433 2434 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2435 * 2436 * When an endpoint has an ASCONF signaled change to be sent to the 2437 * remote endpoint it should do the following: 2438 * ... 2439 * A2) A serial number should be assigned to the Chunk. The serial 2440 * number should be a monotonically increasing number. All serial 2441 * numbers are defined to be initialized at the start of the 2442 * association to the same value as the Initial TSN. 2443 */ 2444 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2445 return 1; 2446 2447 clean_up: 2448 /* Release the transport structures. */ 2449 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2450 transport = list_entry(pos, struct sctp_transport, transports); 2451 if (transport->state != SCTP_ACTIVE) 2452 sctp_assoc_rm_peer(asoc, transport); 2453 } 2454 2455 nomem: 2456 return 0; 2457 } 2458 2459 2460 /* Update asoc with the option described in param. 2461 * 2462 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2463 * 2464 * asoc is the association to update. 2465 * param is the variable length parameter to use for update. 2466 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2467 * If the current packet is an INIT we want to minimize the amount of 2468 * work we do. In particular, we should not build transport 2469 * structures for the addresses. 2470 */ 2471 static int sctp_process_param(struct sctp_association *asoc, 2472 union sctp_params param, 2473 const union sctp_addr *peer_addr, 2474 gfp_t gfp) 2475 { 2476 struct net *net = sock_net(asoc->base.sk); 2477 union sctp_addr addr; 2478 int i; 2479 __u16 sat; 2480 int retval = 1; 2481 sctp_scope_t scope; 2482 time_t stale; 2483 struct sctp_af *af; 2484 union sctp_addr_param *addr_param; 2485 struct sctp_transport *t; 2486 2487 /* We maintain all INIT parameters in network byte order all the 2488 * time. This allows us to not worry about whether the parameters 2489 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2490 */ 2491 switch (param.p->type) { 2492 case SCTP_PARAM_IPV6_ADDRESS: 2493 if (PF_INET6 != asoc->base.sk->sk_family) 2494 break; 2495 goto do_addr_param; 2496 2497 case SCTP_PARAM_IPV4_ADDRESS: 2498 /* v4 addresses are not allowed on v6-only socket */ 2499 if (ipv6_only_sock(asoc->base.sk)) 2500 break; 2501 do_addr_param: 2502 af = sctp_get_af_specific(param_type2af(param.p->type)); 2503 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); 2504 scope = sctp_scope(peer_addr); 2505 if (sctp_in_scope(net, &addr, scope)) 2506 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2507 return 0; 2508 break; 2509 2510 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2511 if (!net->sctp.cookie_preserve_enable) 2512 break; 2513 2514 stale = ntohl(param.life->lifespan_increment); 2515 2516 /* Suggested Cookie Life span increment's unit is msec, 2517 * (1/1000sec). 2518 */ 2519 asoc->cookie_life.tv_sec += stale / 1000; 2520 asoc->cookie_life.tv_usec += (stale % 1000) * 1000; 2521 break; 2522 2523 case SCTP_PARAM_HOST_NAME_ADDRESS: 2524 SCTP_DEBUG_PRINTK("unimplemented SCTP_HOST_NAME_ADDRESS\n"); 2525 break; 2526 2527 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2528 /* Turn off the default values first so we'll know which 2529 * ones are really set by the peer. 2530 */ 2531 asoc->peer.ipv4_address = 0; 2532 asoc->peer.ipv6_address = 0; 2533 2534 /* Assume that peer supports the address family 2535 * by which it sends a packet. 2536 */ 2537 if (peer_addr->sa.sa_family == AF_INET6) 2538 asoc->peer.ipv6_address = 1; 2539 else if (peer_addr->sa.sa_family == AF_INET) 2540 asoc->peer.ipv4_address = 1; 2541 2542 /* Cycle through address types; avoid divide by 0. */ 2543 sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2544 if (sat) 2545 sat /= sizeof(__u16); 2546 2547 for (i = 0; i < sat; ++i) { 2548 switch (param.sat->types[i]) { 2549 case SCTP_PARAM_IPV4_ADDRESS: 2550 asoc->peer.ipv4_address = 1; 2551 break; 2552 2553 case SCTP_PARAM_IPV6_ADDRESS: 2554 if (PF_INET6 == asoc->base.sk->sk_family) 2555 asoc->peer.ipv6_address = 1; 2556 break; 2557 2558 case SCTP_PARAM_HOST_NAME_ADDRESS: 2559 asoc->peer.hostname_address = 1; 2560 break; 2561 2562 default: /* Just ignore anything else. */ 2563 break; 2564 } 2565 } 2566 break; 2567 2568 case SCTP_PARAM_STATE_COOKIE: 2569 asoc->peer.cookie_len = 2570 ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2571 asoc->peer.cookie = param.cookie->body; 2572 break; 2573 2574 case SCTP_PARAM_HEARTBEAT_INFO: 2575 /* Would be odd to receive, but it causes no problems. */ 2576 break; 2577 2578 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2579 /* Rejected during verify stage. */ 2580 break; 2581 2582 case SCTP_PARAM_ECN_CAPABLE: 2583 asoc->peer.ecn_capable = 1; 2584 break; 2585 2586 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2587 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2588 break; 2589 2590 case SCTP_PARAM_SET_PRIMARY: 2591 if (!net->sctp.addip_enable) 2592 goto fall_through; 2593 2594 addr_param = param.v + sizeof(sctp_addip_param_t); 2595 2596 af = sctp_get_af_specific(param_type2af(param.p->type)); 2597 af->from_addr_param(&addr, addr_param, 2598 htons(asoc->peer.port), 0); 2599 2600 /* if the address is invalid, we can't process it. 2601 * XXX: see spec for what to do. 2602 */ 2603 if (!af->addr_valid(&addr, NULL, NULL)) 2604 break; 2605 2606 t = sctp_assoc_lookup_paddr(asoc, &addr); 2607 if (!t) 2608 break; 2609 2610 sctp_assoc_set_primary(asoc, t); 2611 break; 2612 2613 case SCTP_PARAM_SUPPORTED_EXT: 2614 sctp_process_ext_param(asoc, param); 2615 break; 2616 2617 case SCTP_PARAM_FWD_TSN_SUPPORT: 2618 if (net->sctp.prsctp_enable) { 2619 asoc->peer.prsctp_capable = 1; 2620 break; 2621 } 2622 /* Fall Through */ 2623 goto fall_through; 2624 2625 case SCTP_PARAM_RANDOM: 2626 if (!net->sctp.auth_enable) 2627 goto fall_through; 2628 2629 /* Save peer's random parameter */ 2630 asoc->peer.peer_random = kmemdup(param.p, 2631 ntohs(param.p->length), gfp); 2632 if (!asoc->peer.peer_random) { 2633 retval = 0; 2634 break; 2635 } 2636 break; 2637 2638 case SCTP_PARAM_HMAC_ALGO: 2639 if (!net->sctp.auth_enable) 2640 goto fall_through; 2641 2642 /* Save peer's HMAC list */ 2643 asoc->peer.peer_hmacs = kmemdup(param.p, 2644 ntohs(param.p->length), gfp); 2645 if (!asoc->peer.peer_hmacs) { 2646 retval = 0; 2647 break; 2648 } 2649 2650 /* Set the default HMAC the peer requested*/ 2651 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2652 break; 2653 2654 case SCTP_PARAM_CHUNKS: 2655 if (!net->sctp.auth_enable) 2656 goto fall_through; 2657 2658 asoc->peer.peer_chunks = kmemdup(param.p, 2659 ntohs(param.p->length), gfp); 2660 if (!asoc->peer.peer_chunks) 2661 retval = 0; 2662 break; 2663 fall_through: 2664 default: 2665 /* Any unrecognized parameters should have been caught 2666 * and handled by sctp_verify_param() which should be 2667 * called prior to this routine. Simply log the error 2668 * here. 2669 */ 2670 SCTP_DEBUG_PRINTK("Ignoring param: %d for association %p.\n", 2671 ntohs(param.p->type), asoc); 2672 break; 2673 } 2674 2675 return retval; 2676 } 2677 2678 /* Select a new verification tag. */ 2679 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2680 { 2681 /* I believe that this random number generator complies with RFC1750. 2682 * A tag of 0 is reserved for special cases (e.g. INIT). 2683 */ 2684 __u32 x; 2685 2686 do { 2687 get_random_bytes(&x, sizeof(__u32)); 2688 } while (x == 0); 2689 2690 return x; 2691 } 2692 2693 /* Select an initial TSN to send during startup. */ 2694 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2695 { 2696 __u32 retval; 2697 2698 get_random_bytes(&retval, sizeof(__u32)); 2699 return retval; 2700 } 2701 2702 /* 2703 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2704 * 0 1 2 3 2705 * 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 2706 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2707 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2708 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2709 * | Serial Number | 2710 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2711 * | Address Parameter | 2712 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2713 * | ASCONF Parameter #1 | 2714 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2715 * \ \ 2716 * / .... / 2717 * \ \ 2718 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2719 * | ASCONF Parameter #N | 2720 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2721 * 2722 * Address Parameter and other parameter will not be wrapped in this function 2723 */ 2724 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2725 union sctp_addr *addr, 2726 int vparam_len) 2727 { 2728 sctp_addiphdr_t asconf; 2729 struct sctp_chunk *retval; 2730 int length = sizeof(asconf) + vparam_len; 2731 union sctp_addr_param addrparam; 2732 int addrlen; 2733 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2734 2735 addrlen = af->to_addr_param(addr, &addrparam); 2736 if (!addrlen) 2737 return NULL; 2738 length += addrlen; 2739 2740 /* Create the chunk. */ 2741 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF, 0, length); 2742 if (!retval) 2743 return NULL; 2744 2745 asconf.serial = htonl(asoc->addip_serial++); 2746 2747 retval->subh.addip_hdr = 2748 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2749 retval->param_hdr.v = 2750 sctp_addto_chunk(retval, addrlen, &addrparam); 2751 2752 return retval; 2753 } 2754 2755 /* ADDIP 2756 * 3.2.1 Add IP Address 2757 * 0 1 2 3 2758 * 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 2759 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2760 * | Type = 0xC001 | Length = Variable | 2761 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2762 * | ASCONF-Request Correlation ID | 2763 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2764 * | Address Parameter | 2765 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2766 * 2767 * 3.2.2 Delete IP Address 2768 * 0 1 2 3 2769 * 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 2770 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2771 * | Type = 0xC002 | Length = Variable | 2772 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2773 * | ASCONF-Request Correlation ID | 2774 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2775 * | Address Parameter | 2776 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2777 * 2778 */ 2779 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2780 union sctp_addr *laddr, 2781 struct sockaddr *addrs, 2782 int addrcnt, 2783 __be16 flags) 2784 { 2785 sctp_addip_param_t param; 2786 struct sctp_chunk *retval; 2787 union sctp_addr_param addr_param; 2788 union sctp_addr *addr; 2789 void *addr_buf; 2790 struct sctp_af *af; 2791 int paramlen = sizeof(param); 2792 int addr_param_len = 0; 2793 int totallen = 0; 2794 int i; 2795 int del_pickup = 0; 2796 2797 /* Get total length of all the address parameters. */ 2798 addr_buf = addrs; 2799 for (i = 0; i < addrcnt; i++) { 2800 addr = addr_buf; 2801 af = sctp_get_af_specific(addr->v4.sin_family); 2802 addr_param_len = af->to_addr_param(addr, &addr_param); 2803 2804 totallen += paramlen; 2805 totallen += addr_param_len; 2806 2807 addr_buf += af->sockaddr_len; 2808 if (asoc->asconf_addr_del_pending && !del_pickup) { 2809 /* reuse the parameter length from the same scope one */ 2810 totallen += paramlen; 2811 totallen += addr_param_len; 2812 del_pickup = 1; 2813 SCTP_DEBUG_PRINTK("mkasconf_update_ip: picked same-scope del_pending addr, totallen for all addresses is %d\n", totallen); 2814 } 2815 } 2816 2817 /* Create an asconf chunk with the required length. */ 2818 retval = sctp_make_asconf(asoc, laddr, totallen); 2819 if (!retval) 2820 return NULL; 2821 2822 /* Add the address parameters to the asconf chunk. */ 2823 addr_buf = addrs; 2824 for (i = 0; i < addrcnt; i++) { 2825 addr = addr_buf; 2826 af = sctp_get_af_specific(addr->v4.sin_family); 2827 addr_param_len = af->to_addr_param(addr, &addr_param); 2828 param.param_hdr.type = flags; 2829 param.param_hdr.length = htons(paramlen + addr_param_len); 2830 param.crr_id = i; 2831 2832 sctp_addto_chunk(retval, paramlen, ¶m); 2833 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2834 2835 addr_buf += af->sockaddr_len; 2836 } 2837 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2838 addr = asoc->asconf_addr_del_pending; 2839 af = sctp_get_af_specific(addr->v4.sin_family); 2840 addr_param_len = af->to_addr_param(addr, &addr_param); 2841 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2842 param.param_hdr.length = htons(paramlen + addr_param_len); 2843 param.crr_id = i; 2844 2845 sctp_addto_chunk(retval, paramlen, ¶m); 2846 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2847 } 2848 return retval; 2849 } 2850 2851 /* ADDIP 2852 * 3.2.4 Set Primary IP Address 2853 * 0 1 2 3 2854 * 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 2855 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2856 * | Type =0xC004 | Length = Variable | 2857 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2858 * | ASCONF-Request Correlation ID | 2859 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2860 * | Address Parameter | 2861 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2862 * 2863 * Create an ASCONF chunk with Set Primary IP address parameter. 2864 */ 2865 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2866 union sctp_addr *addr) 2867 { 2868 sctp_addip_param_t param; 2869 struct sctp_chunk *retval; 2870 int len = sizeof(param); 2871 union sctp_addr_param addrparam; 2872 int addrlen; 2873 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2874 2875 addrlen = af->to_addr_param(addr, &addrparam); 2876 if (!addrlen) 2877 return NULL; 2878 len += addrlen; 2879 2880 /* Create the chunk and make asconf header. */ 2881 retval = sctp_make_asconf(asoc, addr, len); 2882 if (!retval) 2883 return NULL; 2884 2885 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2886 param.param_hdr.length = htons(len); 2887 param.crr_id = 0; 2888 2889 sctp_addto_chunk(retval, sizeof(param), ¶m); 2890 sctp_addto_chunk(retval, addrlen, &addrparam); 2891 2892 return retval; 2893 } 2894 2895 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2896 * 0 1 2 3 2897 * 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 2898 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2899 * | Type = 0x80 | Chunk Flags | Chunk Length | 2900 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2901 * | Serial Number | 2902 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2903 * | ASCONF Parameter Response#1 | 2904 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2905 * \ \ 2906 * / .... / 2907 * \ \ 2908 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2909 * | ASCONF Parameter Response#N | 2910 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2911 * 2912 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2913 */ 2914 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2915 __u32 serial, int vparam_len) 2916 { 2917 sctp_addiphdr_t asconf; 2918 struct sctp_chunk *retval; 2919 int length = sizeof(asconf) + vparam_len; 2920 2921 /* Create the chunk. */ 2922 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF_ACK, 0, length); 2923 if (!retval) 2924 return NULL; 2925 2926 asconf.serial = htonl(serial); 2927 2928 retval->subh.addip_hdr = 2929 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2930 2931 return retval; 2932 } 2933 2934 /* Add response parameters to an ASCONF_ACK chunk. */ 2935 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2936 __be16 err_code, sctp_addip_param_t *asconf_param) 2937 { 2938 sctp_addip_param_t ack_param; 2939 sctp_errhdr_t err_param; 2940 int asconf_param_len = 0; 2941 int err_param_len = 0; 2942 __be16 response_type; 2943 2944 if (SCTP_ERROR_NO_ERROR == err_code) { 2945 response_type = SCTP_PARAM_SUCCESS_REPORT; 2946 } else { 2947 response_type = SCTP_PARAM_ERR_CAUSE; 2948 err_param_len = sizeof(err_param); 2949 if (asconf_param) 2950 asconf_param_len = 2951 ntohs(asconf_param->param_hdr.length); 2952 } 2953 2954 /* Add Success Indication or Error Cause Indication parameter. */ 2955 ack_param.param_hdr.type = response_type; 2956 ack_param.param_hdr.length = htons(sizeof(ack_param) + 2957 err_param_len + 2958 asconf_param_len); 2959 ack_param.crr_id = crr_id; 2960 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 2961 2962 if (SCTP_ERROR_NO_ERROR == err_code) 2963 return; 2964 2965 /* Add Error Cause parameter. */ 2966 err_param.cause = err_code; 2967 err_param.length = htons(err_param_len + asconf_param_len); 2968 sctp_addto_chunk(chunk, err_param_len, &err_param); 2969 2970 /* Add the failed TLV copied from ASCONF chunk. */ 2971 if (asconf_param) 2972 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 2973 } 2974 2975 /* Process a asconf parameter. */ 2976 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 2977 struct sctp_chunk *asconf, 2978 sctp_addip_param_t *asconf_param) 2979 { 2980 struct sctp_transport *peer; 2981 struct sctp_af *af; 2982 union sctp_addr addr; 2983 union sctp_addr_param *addr_param; 2984 2985 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t); 2986 2987 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 2988 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 2989 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 2990 return SCTP_ERROR_UNKNOWN_PARAM; 2991 2992 switch (addr_param->p.type) { 2993 case SCTP_PARAM_IPV6_ADDRESS: 2994 if (!asoc->peer.ipv6_address) 2995 return SCTP_ERROR_DNS_FAILED; 2996 break; 2997 case SCTP_PARAM_IPV4_ADDRESS: 2998 if (!asoc->peer.ipv4_address) 2999 return SCTP_ERROR_DNS_FAILED; 3000 break; 3001 default: 3002 return SCTP_ERROR_DNS_FAILED; 3003 } 3004 3005 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3006 if (unlikely(!af)) 3007 return SCTP_ERROR_DNS_FAILED; 3008 3009 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); 3010 3011 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3012 * or multicast address. 3013 * (note: wildcard is permitted and requires special handling so 3014 * make sure we check for that) 3015 */ 3016 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3017 return SCTP_ERROR_DNS_FAILED; 3018 3019 switch (asconf_param->param_hdr.type) { 3020 case SCTP_PARAM_ADD_IP: 3021 /* Section 4.2.1: 3022 * If the address 0.0.0.0 or ::0 is provided, the source 3023 * address of the packet MUST be added. 3024 */ 3025 if (af->is_any(&addr)) 3026 memcpy(&addr, &asconf->source, sizeof(addr)); 3027 3028 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3029 * request and does not have the local resources to add this 3030 * new address to the association, it MUST return an Error 3031 * Cause TLV set to the new error code 'Operation Refused 3032 * Due to Resource Shortage'. 3033 */ 3034 3035 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3036 if (!peer) 3037 return SCTP_ERROR_RSRC_LOW; 3038 3039 /* Start the heartbeat timer. */ 3040 if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer))) 3041 sctp_transport_hold(peer); 3042 asoc->new_transport = peer; 3043 break; 3044 case SCTP_PARAM_DEL_IP: 3045 /* ADDIP 4.3 D7) If a request is received to delete the 3046 * last remaining IP address of a peer endpoint, the receiver 3047 * MUST send an Error Cause TLV with the error cause set to the 3048 * new error code 'Request to Delete Last Remaining IP Address'. 3049 */ 3050 if (asoc->peer.transport_count == 1) 3051 return SCTP_ERROR_DEL_LAST_IP; 3052 3053 /* ADDIP 4.3 D8) If a request is received to delete an IP 3054 * address which is also the source address of the IP packet 3055 * which contained the ASCONF chunk, the receiver MUST reject 3056 * this request. To reject the request the receiver MUST send 3057 * an Error Cause TLV set to the new error code 'Request to 3058 * Delete Source IP Address' 3059 */ 3060 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3061 return SCTP_ERROR_DEL_SRC_IP; 3062 3063 /* Section 4.2.2 3064 * If the address 0.0.0.0 or ::0 is provided, all 3065 * addresses of the peer except the source address of the 3066 * packet MUST be deleted. 3067 */ 3068 if (af->is_any(&addr)) { 3069 sctp_assoc_set_primary(asoc, asconf->transport); 3070 sctp_assoc_del_nonprimary_peers(asoc, 3071 asconf->transport); 3072 } else 3073 sctp_assoc_del_peer(asoc, &addr); 3074 break; 3075 case SCTP_PARAM_SET_PRIMARY: 3076 /* ADDIP Section 4.2.4 3077 * If the address 0.0.0.0 or ::0 is provided, the receiver 3078 * MAY mark the source address of the packet as its 3079 * primary. 3080 */ 3081 if (af->is_any(&addr)) 3082 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr)); 3083 3084 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3085 if (!peer) 3086 return SCTP_ERROR_DNS_FAILED; 3087 3088 sctp_assoc_set_primary(asoc, peer); 3089 break; 3090 } 3091 3092 return SCTP_ERROR_NO_ERROR; 3093 } 3094 3095 /* Verify the ASCONF packet before we process it. */ 3096 int sctp_verify_asconf(const struct sctp_association *asoc, 3097 struct sctp_paramhdr *param_hdr, void *chunk_end, 3098 struct sctp_paramhdr **errp) { 3099 sctp_addip_param_t *asconf_param; 3100 union sctp_params param; 3101 int length, plen; 3102 3103 param.v = (sctp_paramhdr_t *) param_hdr; 3104 while (param.v <= chunk_end - sizeof(sctp_paramhdr_t)) { 3105 length = ntohs(param.p->length); 3106 *errp = param.p; 3107 3108 if (param.v > chunk_end - length || 3109 length < sizeof(sctp_paramhdr_t)) 3110 return 0; 3111 3112 switch (param.p->type) { 3113 case SCTP_PARAM_ADD_IP: 3114 case SCTP_PARAM_DEL_IP: 3115 case SCTP_PARAM_SET_PRIMARY: 3116 asconf_param = (sctp_addip_param_t *)param.v; 3117 plen = ntohs(asconf_param->param_hdr.length); 3118 if (plen < sizeof(sctp_addip_param_t) + 3119 sizeof(sctp_paramhdr_t)) 3120 return 0; 3121 break; 3122 case SCTP_PARAM_SUCCESS_REPORT: 3123 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3124 if (length != sizeof(sctp_addip_param_t)) 3125 return 0; 3126 3127 break; 3128 default: 3129 break; 3130 } 3131 3132 param.v += WORD_ROUND(length); 3133 } 3134 3135 if (param.v != chunk_end) 3136 return 0; 3137 3138 return 1; 3139 } 3140 3141 /* Process an incoming ASCONF chunk with the next expected serial no. and 3142 * return an ASCONF_ACK chunk to be sent in response. 3143 */ 3144 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3145 struct sctp_chunk *asconf) 3146 { 3147 sctp_addiphdr_t *hdr; 3148 union sctp_addr_param *addr_param; 3149 sctp_addip_param_t *asconf_param; 3150 struct sctp_chunk *asconf_ack; 3151 3152 __be16 err_code; 3153 int length = 0; 3154 int chunk_len; 3155 __u32 serial; 3156 int all_param_pass = 1; 3157 3158 chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t); 3159 hdr = (sctp_addiphdr_t *)asconf->skb->data; 3160 serial = ntohl(hdr->serial); 3161 3162 /* Skip the addiphdr and store a pointer to address parameter. */ 3163 length = sizeof(sctp_addiphdr_t); 3164 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3165 chunk_len -= length; 3166 3167 /* Skip the address parameter and store a pointer to the first 3168 * asconf parameter. 3169 */ 3170 length = ntohs(addr_param->p.length); 3171 asconf_param = (void *)addr_param + length; 3172 chunk_len -= length; 3173 3174 /* create an ASCONF_ACK chunk. 3175 * Based on the definitions of parameters, we know that the size of 3176 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3177 * parameters. 3178 */ 3179 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3180 if (!asconf_ack) 3181 goto done; 3182 3183 /* Process the TLVs contained within the ASCONF chunk. */ 3184 while (chunk_len > 0) { 3185 err_code = sctp_process_asconf_param(asoc, asconf, 3186 asconf_param); 3187 /* ADDIP 4.1 A7) 3188 * If an error response is received for a TLV parameter, 3189 * all TLVs with no response before the failed TLV are 3190 * considered successful if not reported. All TLVs after 3191 * the failed response are considered unsuccessful unless 3192 * a specific success indication is present for the parameter. 3193 */ 3194 if (SCTP_ERROR_NO_ERROR != err_code) 3195 all_param_pass = 0; 3196 3197 if (!all_param_pass) 3198 sctp_add_asconf_response(asconf_ack, 3199 asconf_param->crr_id, err_code, 3200 asconf_param); 3201 3202 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3203 * an IP address sends an 'Out of Resource' in its response, it 3204 * MUST also fail any subsequent add or delete requests bundled 3205 * in the ASCONF. 3206 */ 3207 if (SCTP_ERROR_RSRC_LOW == err_code) 3208 goto done; 3209 3210 /* Move to the next ASCONF param. */ 3211 length = ntohs(asconf_param->param_hdr.length); 3212 asconf_param = (void *)asconf_param + length; 3213 chunk_len -= length; 3214 } 3215 3216 done: 3217 asoc->peer.addip_serial++; 3218 3219 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3220 * after freeing the reference to old asconf ack if any. 3221 */ 3222 if (asconf_ack) { 3223 sctp_chunk_hold(asconf_ack); 3224 list_add_tail(&asconf_ack->transmitted_list, 3225 &asoc->asconf_ack_list); 3226 } 3227 3228 return asconf_ack; 3229 } 3230 3231 /* Process a asconf parameter that is successfully acked. */ 3232 static void sctp_asconf_param_success(struct sctp_association *asoc, 3233 sctp_addip_param_t *asconf_param) 3234 { 3235 struct sctp_af *af; 3236 union sctp_addr addr; 3237 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3238 union sctp_addr_param *addr_param; 3239 struct sctp_transport *transport; 3240 struct sctp_sockaddr_entry *saddr; 3241 3242 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t); 3243 3244 /* We have checked the packet before, so we do not check again. */ 3245 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3246 af->from_addr_param(&addr, addr_param, htons(bp->port), 0); 3247 3248 switch (asconf_param->param_hdr.type) { 3249 case SCTP_PARAM_ADD_IP: 3250 /* This is always done in BH context with a socket lock 3251 * held, so the list can not change. 3252 */ 3253 local_bh_disable(); 3254 list_for_each_entry(saddr, &bp->address_list, list) { 3255 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3256 saddr->state = SCTP_ADDR_SRC; 3257 } 3258 local_bh_enable(); 3259 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3260 transports) { 3261 dst_release(transport->dst); 3262 transport->dst = NULL; 3263 } 3264 break; 3265 case SCTP_PARAM_DEL_IP: 3266 local_bh_disable(); 3267 sctp_del_bind_addr(bp, &addr); 3268 if (asoc->asconf_addr_del_pending != NULL && 3269 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3270 kfree(asoc->asconf_addr_del_pending); 3271 asoc->asconf_addr_del_pending = NULL; 3272 } 3273 local_bh_enable(); 3274 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3275 transports) { 3276 dst_release(transport->dst); 3277 transport->dst = NULL; 3278 } 3279 break; 3280 default: 3281 break; 3282 } 3283 } 3284 3285 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3286 * for the given asconf parameter. If there is no response for this parameter, 3287 * return the error code based on the third argument 'no_err'. 3288 * ADDIP 4.1 3289 * A7) If an error response is received for a TLV parameter, all TLVs with no 3290 * response before the failed TLV are considered successful if not reported. 3291 * All TLVs after the failed response are considered unsuccessful unless a 3292 * specific success indication is present for the parameter. 3293 */ 3294 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3295 sctp_addip_param_t *asconf_param, 3296 int no_err) 3297 { 3298 sctp_addip_param_t *asconf_ack_param; 3299 sctp_errhdr_t *err_param; 3300 int length; 3301 int asconf_ack_len; 3302 __be16 err_code; 3303 3304 if (no_err) 3305 err_code = SCTP_ERROR_NO_ERROR; 3306 else 3307 err_code = SCTP_ERROR_REQ_REFUSED; 3308 3309 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3310 sizeof(sctp_chunkhdr_t); 3311 3312 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3313 * the first asconf_ack parameter. 3314 */ 3315 length = sizeof(sctp_addiphdr_t); 3316 asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data + 3317 length); 3318 asconf_ack_len -= length; 3319 3320 while (asconf_ack_len > 0) { 3321 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3322 switch(asconf_ack_param->param_hdr.type) { 3323 case SCTP_PARAM_SUCCESS_REPORT: 3324 return SCTP_ERROR_NO_ERROR; 3325 case SCTP_PARAM_ERR_CAUSE: 3326 length = sizeof(sctp_addip_param_t); 3327 err_param = (void *)asconf_ack_param + length; 3328 asconf_ack_len -= length; 3329 if (asconf_ack_len > 0) 3330 return err_param->cause; 3331 else 3332 return SCTP_ERROR_INV_PARAM; 3333 break; 3334 default: 3335 return SCTP_ERROR_INV_PARAM; 3336 } 3337 } 3338 3339 length = ntohs(asconf_ack_param->param_hdr.length); 3340 asconf_ack_param = (void *)asconf_ack_param + length; 3341 asconf_ack_len -= length; 3342 } 3343 3344 return err_code; 3345 } 3346 3347 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3348 int sctp_process_asconf_ack(struct sctp_association *asoc, 3349 struct sctp_chunk *asconf_ack) 3350 { 3351 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3352 union sctp_addr_param *addr_param; 3353 sctp_addip_param_t *asconf_param; 3354 int length = 0; 3355 int asconf_len = asconf->skb->len; 3356 int all_param_pass = 0; 3357 int no_err = 1; 3358 int retval = 0; 3359 __be16 err_code = SCTP_ERROR_NO_ERROR; 3360 3361 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3362 * a pointer to address parameter. 3363 */ 3364 length = sizeof(sctp_addip_chunk_t); 3365 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3366 asconf_len -= length; 3367 3368 /* Skip the address parameter in the last asconf sent and store a 3369 * pointer to the first asconf parameter. 3370 */ 3371 length = ntohs(addr_param->p.length); 3372 asconf_param = (void *)addr_param + length; 3373 asconf_len -= length; 3374 3375 /* ADDIP 4.1 3376 * A8) If there is no response(s) to specific TLV parameter(s), and no 3377 * failures are indicated, then all request(s) are considered 3378 * successful. 3379 */ 3380 if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t)) 3381 all_param_pass = 1; 3382 3383 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3384 while (asconf_len > 0) { 3385 if (all_param_pass) 3386 err_code = SCTP_ERROR_NO_ERROR; 3387 else { 3388 err_code = sctp_get_asconf_response(asconf_ack, 3389 asconf_param, 3390 no_err); 3391 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3392 no_err = 0; 3393 } 3394 3395 switch (err_code) { 3396 case SCTP_ERROR_NO_ERROR: 3397 sctp_asconf_param_success(asoc, asconf_param); 3398 break; 3399 3400 case SCTP_ERROR_RSRC_LOW: 3401 retval = 1; 3402 break; 3403 3404 case SCTP_ERROR_UNKNOWN_PARAM: 3405 /* Disable sending this type of asconf parameter in 3406 * future. 3407 */ 3408 asoc->peer.addip_disabled_mask |= 3409 asconf_param->param_hdr.type; 3410 break; 3411 3412 case SCTP_ERROR_REQ_REFUSED: 3413 case SCTP_ERROR_DEL_LAST_IP: 3414 case SCTP_ERROR_DEL_SRC_IP: 3415 default: 3416 break; 3417 } 3418 3419 /* Skip the processed asconf parameter and move to the next 3420 * one. 3421 */ 3422 length = ntohs(asconf_param->param_hdr.length); 3423 asconf_param = (void *)asconf_param + length; 3424 asconf_len -= length; 3425 } 3426 3427 if (no_err && asoc->src_out_of_asoc_ok) { 3428 asoc->src_out_of_asoc_ok = 0; 3429 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3430 } 3431 3432 /* Free the cached last sent asconf chunk. */ 3433 list_del_init(&asconf->transmitted_list); 3434 sctp_chunk_free(asconf); 3435 asoc->addip_last_asconf = NULL; 3436 3437 return retval; 3438 } 3439 3440 /* Make a FWD TSN chunk. */ 3441 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3442 __u32 new_cum_tsn, size_t nstreams, 3443 struct sctp_fwdtsn_skip *skiplist) 3444 { 3445 struct sctp_chunk *retval = NULL; 3446 struct sctp_fwdtsn_hdr ftsn_hdr; 3447 struct sctp_fwdtsn_skip skip; 3448 size_t hint; 3449 int i; 3450 3451 hint = (nstreams + 1) * sizeof(__u32); 3452 3453 retval = sctp_make_chunk(asoc, SCTP_CID_FWD_TSN, 0, hint); 3454 3455 if (!retval) 3456 return NULL; 3457 3458 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3459 retval->subh.fwdtsn_hdr = 3460 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3461 3462 for (i = 0; i < nstreams; i++) { 3463 skip.stream = skiplist[i].stream; 3464 skip.ssn = skiplist[i].ssn; 3465 sctp_addto_chunk(retval, sizeof(skip), &skip); 3466 } 3467 3468 return retval; 3469 } 3470