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 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 sctp_inithdr_t init; 202 union sctp_params addrs; 203 size_t chunksize; 204 struct sctp_chunk *retval = NULL; 205 int num_types, addrs_len = 0; 206 struct sctp_sock *sp; 207 sctp_supported_addrs_param_t sat; 208 __be16 types[2]; 209 sctp_adaptation_ind_param_t aiparam; 210 sctp_supported_ext_param_t ext_param; 211 int num_ext = 0; 212 __u8 extensions[3]; 213 sctp_paramhdr_t *auth_chunks = NULL, 214 *auth_hmacs = NULL; 215 216 /* RFC 2960 3.3.2 Initiation (INIT) (1) 217 * 218 * Note 1: The INIT chunks can contain multiple addresses that 219 * can be IPv4 and/or IPv6 in any combination. 220 */ 221 retval = NULL; 222 223 /* Convert the provided bind address list to raw format. */ 224 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp); 225 226 init.init_tag = htonl(asoc->c.my_vtag); 227 init.a_rwnd = htonl(asoc->rwnd); 228 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 229 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 230 init.initial_tsn = htonl(asoc->c.initial_tsn); 231 232 /* How many address types are needed? */ 233 sp = sctp_sk(asoc->base.sk); 234 num_types = sp->pf->supported_addrs(sp, types); 235 236 chunksize = sizeof(init) + addrs_len; 237 chunksize += WORD_ROUND(SCTP_SAT_LEN(num_types)); 238 chunksize += sizeof(ecap_param); 239 240 if (sctp_prsctp_enable) 241 chunksize += sizeof(prsctp_param); 242 243 /* ADDIP: Section 4.2.7: 244 * An implementation supporting this extension [ADDIP] MUST list 245 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and 246 * INIT-ACK parameters. 247 */ 248 if (sctp_addip_enable) { 249 extensions[num_ext] = SCTP_CID_ASCONF; 250 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 251 num_ext += 2; 252 } 253 254 if (sp->adaptation_ind) 255 chunksize += sizeof(aiparam); 256 257 chunksize += vparam_len; 258 259 /* Account for AUTH related parameters */ 260 if (sctp_auth_enable) { 261 /* Add random parameter length*/ 262 chunksize += sizeof(asoc->c.auth_random); 263 264 /* Add HMACS parameter length if any were defined */ 265 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs; 266 if (auth_hmacs->length) 267 chunksize += WORD_ROUND(ntohs(auth_hmacs->length)); 268 else 269 auth_hmacs = NULL; 270 271 /* Add CHUNKS parameter length */ 272 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks; 273 if (auth_chunks->length) 274 chunksize += WORD_ROUND(ntohs(auth_chunks->length)); 275 else 276 auth_chunks = NULL; 277 278 extensions[num_ext] = SCTP_CID_AUTH; 279 num_ext += 1; 280 } 281 282 /* If we have any extensions to report, account for that */ 283 if (num_ext) 284 chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) + 285 num_ext); 286 287 /* RFC 2960 3.3.2 Initiation (INIT) (1) 288 * 289 * Note 3: An INIT chunk MUST NOT contain more than one Host 290 * Name address parameter. Moreover, the sender of the INIT 291 * MUST NOT combine any other address types with the Host Name 292 * address in the INIT. The receiver of INIT MUST ignore any 293 * other address types if the Host Name address parameter is 294 * present in the received INIT chunk. 295 * 296 * PLEASE DO NOT FIXME [This version does not support Host Name.] 297 */ 298 299 retval = sctp_make_chunk(asoc, SCTP_CID_INIT, 0, chunksize); 300 if (!retval) 301 goto nodata; 302 303 retval->subh.init_hdr = 304 sctp_addto_chunk(retval, sizeof(init), &init); 305 retval->param_hdr.v = 306 sctp_addto_chunk(retval, addrs_len, addrs.v); 307 308 /* RFC 2960 3.3.2 Initiation (INIT) (1) 309 * 310 * Note 4: This parameter, when present, specifies all the 311 * address types the sending endpoint can support. The absence 312 * of this parameter indicates that the sending endpoint can 313 * support any address type. 314 */ 315 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES; 316 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types)); 317 sctp_addto_chunk(retval, sizeof(sat), &sat); 318 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types); 319 320 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 321 322 /* Add the supported extensions parameter. Be nice and add this 323 * fist before addiding the parameters for the extensions themselves 324 */ 325 if (num_ext) { 326 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 327 ext_param.param_hdr.length = 328 htons(sizeof(sctp_supported_ext_param_t) + num_ext); 329 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t), 330 &ext_param); 331 sctp_addto_param(retval, num_ext, extensions); 332 } 333 334 if (sctp_prsctp_enable) 335 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 336 337 if (sp->adaptation_ind) { 338 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 339 aiparam.param_hdr.length = htons(sizeof(aiparam)); 340 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 341 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 342 } 343 344 /* Add SCTP-AUTH chunks to the parameter list */ 345 if (sctp_auth_enable) { 346 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random), 347 asoc->c.auth_random); 348 if (auth_hmacs) 349 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 350 auth_hmacs); 351 if (auth_chunks) 352 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 353 auth_chunks); 354 } 355 nodata: 356 kfree(addrs.v); 357 return retval; 358 } 359 360 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, 361 const struct sctp_chunk *chunk, 362 gfp_t gfp, int unkparam_len) 363 { 364 sctp_inithdr_t initack; 365 struct sctp_chunk *retval; 366 union sctp_params addrs; 367 struct sctp_sock *sp; 368 int addrs_len; 369 sctp_cookie_param_t *cookie; 370 int cookie_len; 371 size_t chunksize; 372 sctp_adaptation_ind_param_t aiparam; 373 sctp_supported_ext_param_t ext_param; 374 int num_ext = 0; 375 __u8 extensions[3]; 376 sctp_paramhdr_t *auth_chunks = NULL, 377 *auth_hmacs = NULL, 378 *auth_random = NULL; 379 380 retval = NULL; 381 382 /* Note: there may be no addresses to embed. */ 383 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp); 384 385 initack.init_tag = htonl(asoc->c.my_vtag); 386 initack.a_rwnd = htonl(asoc->rwnd); 387 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 388 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 389 initack.initial_tsn = htonl(asoc->c.initial_tsn); 390 391 /* FIXME: We really ought to build the cookie right 392 * into the packet instead of allocating more fresh memory. 393 */ 394 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len, 395 addrs.v, addrs_len); 396 if (!cookie) 397 goto nomem_cookie; 398 399 /* Calculate the total size of allocation, include the reserved 400 * space for reporting unknown parameters if it is specified. 401 */ 402 sp = sctp_sk(asoc->base.sk); 403 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len; 404 405 /* Tell peer that we'll do ECN only if peer advertised such cap. */ 406 if (asoc->peer.ecn_capable) 407 chunksize += sizeof(ecap_param); 408 409 if (asoc->peer.prsctp_capable) 410 chunksize += sizeof(prsctp_param); 411 412 if (asoc->peer.asconf_capable) { 413 extensions[num_ext] = SCTP_CID_ASCONF; 414 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 415 num_ext += 2; 416 } 417 418 if (sp->adaptation_ind) 419 chunksize += sizeof(aiparam); 420 421 if (asoc->peer.auth_capable) { 422 auth_random = (sctp_paramhdr_t *)asoc->c.auth_random; 423 chunksize += ntohs(auth_random->length); 424 425 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs; 426 if (auth_hmacs->length) 427 chunksize += WORD_ROUND(ntohs(auth_hmacs->length)); 428 else 429 auth_hmacs = NULL; 430 431 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks; 432 if (auth_chunks->length) 433 chunksize += WORD_ROUND(ntohs(auth_chunks->length)); 434 else 435 auth_chunks = NULL; 436 437 extensions[num_ext] = SCTP_CID_AUTH; 438 num_ext += 1; 439 } 440 441 if (num_ext) 442 chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) + 443 num_ext); 444 445 /* Now allocate and fill out the chunk. */ 446 retval = sctp_make_chunk(asoc, SCTP_CID_INIT_ACK, 0, chunksize); 447 if (!retval) 448 goto nomem_chunk; 449 450 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 451 * 452 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 453 * HEARTBEAT ACK, * etc.) to the same destination transport 454 * address from which it received the DATA or control chunk 455 * to which it is replying. 456 * 457 * [INIT ACK back to where the INIT came from.] 458 */ 459 retval->transport = chunk->transport; 460 461 retval->subh.init_hdr = 462 sctp_addto_chunk(retval, sizeof(initack), &initack); 463 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); 464 sctp_addto_chunk(retval, cookie_len, cookie); 465 if (asoc->peer.ecn_capable) 466 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 467 if (num_ext) { 468 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 469 ext_param.param_hdr.length = 470 htons(sizeof(sctp_supported_ext_param_t) + num_ext); 471 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t), 472 &ext_param); 473 sctp_addto_param(retval, num_ext, extensions); 474 } 475 if (asoc->peer.prsctp_capable) 476 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 477 478 if (sp->adaptation_ind) { 479 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 480 aiparam.param_hdr.length = htons(sizeof(aiparam)); 481 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 482 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 483 } 484 485 if (asoc->peer.auth_capable) { 486 sctp_addto_chunk(retval, ntohs(auth_random->length), 487 auth_random); 488 if (auth_hmacs) 489 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 490 auth_hmacs); 491 if (auth_chunks) 492 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 493 auth_chunks); 494 } 495 496 /* We need to remove the const qualifier at this point. */ 497 retval->asoc = (struct sctp_association *) asoc; 498 499 nomem_chunk: 500 kfree(cookie); 501 nomem_cookie: 502 kfree(addrs.v); 503 return retval; 504 } 505 506 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10): 507 * 508 * This chunk is used only during the initialization of an association. 509 * It is sent by the initiator of an association to its peer to complete 510 * the initialization process. This chunk MUST precede any DATA chunk 511 * sent within the association, but MAY be bundled with one or more DATA 512 * chunks in the same packet. 513 * 514 * 0 1 2 3 515 * 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 1 516 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 517 * | Type = 10 |Chunk Flags | Length | 518 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 519 * / Cookie / 520 * \ \ 521 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 522 * 523 * Chunk Flags: 8 bit 524 * 525 * Set to zero on transmit and ignored on receipt. 526 * 527 * Length: 16 bits (unsigned integer) 528 * 529 * Set to the size of the chunk in bytes, including the 4 bytes of 530 * the chunk header and the size of the Cookie. 531 * 532 * Cookie: variable size 533 * 534 * This field must contain the exact cookie received in the 535 * State Cookie parameter from the previous INIT ACK. 536 * 537 * An implementation SHOULD make the cookie as small as possible 538 * to insure interoperability. 539 */ 540 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, 541 const struct sctp_chunk *chunk) 542 { 543 struct sctp_chunk *retval; 544 void *cookie; 545 int cookie_len; 546 547 cookie = asoc->peer.cookie; 548 cookie_len = asoc->peer.cookie_len; 549 550 /* Build a cookie echo chunk. */ 551 retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ECHO, 0, cookie_len); 552 if (!retval) 553 goto nodata; 554 retval->subh.cookie_hdr = 555 sctp_addto_chunk(retval, cookie_len, cookie); 556 557 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 558 * 559 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 560 * HEARTBEAT ACK, * etc.) to the same destination transport 561 * address from which it * received the DATA or control chunk 562 * to which it is replying. 563 * 564 * [COOKIE ECHO back to where the INIT ACK came from.] 565 */ 566 if (chunk) 567 retval->transport = chunk->transport; 568 569 nodata: 570 return retval; 571 } 572 573 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11): 574 * 575 * This chunk is used only during the initialization of an 576 * association. It is used to acknowledge the receipt of a COOKIE 577 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent 578 * within the association, but MAY be bundled with one or more DATA 579 * chunks or SACK chunk in the same SCTP packet. 580 * 581 * 0 1 2 3 582 * 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 1 583 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 584 * | Type = 11 |Chunk Flags | Length = 4 | 585 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 586 * 587 * Chunk Flags: 8 bits 588 * 589 * Set to zero on transmit and ignored on receipt. 590 */ 591 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, 592 const struct sctp_chunk *chunk) 593 { 594 struct sctp_chunk *retval; 595 596 retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ACK, 0, 0); 597 598 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 599 * 600 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 601 * HEARTBEAT ACK, * etc.) to the same destination transport 602 * address from which it * received the DATA or control chunk 603 * to which it is replying. 604 * 605 * [COOKIE ACK back to where the COOKIE ECHO came from.] 606 */ 607 if (retval && chunk) 608 retval->transport = chunk->transport; 609 610 return retval; 611 } 612 613 /* 614 * Appendix A: Explicit Congestion Notification: 615 * CWR: 616 * 617 * RFC 2481 details a specific bit for a sender to send in the header of 618 * its next outbound TCP segment to indicate to its peer that it has 619 * reduced its congestion window. This is termed the CWR bit. For 620 * SCTP the same indication is made by including the CWR chunk. 621 * This chunk contains one data element, i.e. the TSN number that 622 * was sent in the ECNE chunk. This element represents the lowest 623 * TSN number in the datagram that was originally marked with the 624 * CE bit. 625 * 626 * 0 1 2 3 627 * 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 1 628 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 629 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 | 630 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 631 * | Lowest TSN Number | 632 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 633 * 634 * Note: The CWR is considered a Control chunk. 635 */ 636 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, 637 const __u32 lowest_tsn, 638 const struct sctp_chunk *chunk) 639 { 640 struct sctp_chunk *retval; 641 sctp_cwrhdr_t cwr; 642 643 cwr.lowest_tsn = htonl(lowest_tsn); 644 retval = sctp_make_chunk(asoc, SCTP_CID_ECN_CWR, 0, 645 sizeof(sctp_cwrhdr_t)); 646 647 if (!retval) 648 goto nodata; 649 650 retval->subh.ecn_cwr_hdr = 651 sctp_addto_chunk(retval, sizeof(cwr), &cwr); 652 653 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 654 * 655 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 656 * HEARTBEAT ACK, * etc.) to the same destination transport 657 * address from which it * received the DATA or control chunk 658 * to which it is replying. 659 * 660 * [Report a reduced congestion window back to where the ECNE 661 * came from.] 662 */ 663 if (chunk) 664 retval->transport = chunk->transport; 665 666 nodata: 667 return retval; 668 } 669 670 /* Make an ECNE chunk. This is a congestion experienced report. */ 671 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, 672 const __u32 lowest_tsn) 673 { 674 struct sctp_chunk *retval; 675 sctp_ecnehdr_t ecne; 676 677 ecne.lowest_tsn = htonl(lowest_tsn); 678 retval = sctp_make_chunk(asoc, SCTP_CID_ECN_ECNE, 0, 679 sizeof(sctp_ecnehdr_t)); 680 if (!retval) 681 goto nodata; 682 retval->subh.ecne_hdr = 683 sctp_addto_chunk(retval, sizeof(ecne), &ecne); 684 685 nodata: 686 return retval; 687 } 688 689 /* Make a DATA chunk for the given association from the provided 690 * parameters. However, do not populate the data payload. 691 */ 692 struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc, 693 const struct sctp_sndrcvinfo *sinfo, 694 int data_len, __u8 flags, __u16 ssn) 695 { 696 struct sctp_chunk *retval; 697 struct sctp_datahdr dp; 698 int chunk_len; 699 700 /* We assign the TSN as LATE as possible, not here when 701 * creating the chunk. 702 */ 703 dp.tsn = 0; 704 dp.stream = htons(sinfo->sinfo_stream); 705 dp.ppid = sinfo->sinfo_ppid; 706 707 /* Set the flags for an unordered send. */ 708 if (sinfo->sinfo_flags & SCTP_UNORDERED) { 709 flags |= SCTP_DATA_UNORDERED; 710 dp.ssn = 0; 711 } else 712 dp.ssn = htons(ssn); 713 714 chunk_len = sizeof(dp) + data_len; 715 retval = sctp_make_chunk(asoc, SCTP_CID_DATA, flags, chunk_len); 716 if (!retval) 717 goto nodata; 718 719 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp); 720 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo)); 721 722 nodata: 723 return retval; 724 } 725 726 /* Create a selective ackowledgement (SACK) for the given 727 * association. This reports on which TSN's we've seen to date, 728 * including duplicates and gaps. 729 */ 730 struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc) 731 { 732 struct sctp_chunk *retval; 733 struct sctp_sackhdr sack; 734 int len; 735 __u32 ctsn; 736 __u16 num_gabs, num_dup_tsns; 737 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; 738 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; 739 740 memset(gabs, 0, sizeof(gabs)); 741 ctsn = sctp_tsnmap_get_ctsn(map); 742 SCTP_DEBUG_PRINTK("sackCTSNAck sent: 0x%x.\n", ctsn); 743 744 /* How much room is needed in the chunk? */ 745 num_gabs = sctp_tsnmap_num_gabs(map, gabs); 746 num_dup_tsns = sctp_tsnmap_num_dups(map); 747 748 /* Initialize the SACK header. */ 749 sack.cum_tsn_ack = htonl(ctsn); 750 sack.a_rwnd = htonl(asoc->a_rwnd); 751 sack.num_gap_ack_blocks = htons(num_gabs); 752 sack.num_dup_tsns = htons(num_dup_tsns); 753 754 len = sizeof(sack) 755 + sizeof(struct sctp_gap_ack_block) * num_gabs 756 + sizeof(__u32) * num_dup_tsns; 757 758 /* Create the chunk. */ 759 retval = sctp_make_chunk(asoc, SCTP_CID_SACK, 0, len); 760 if (!retval) 761 goto nodata; 762 763 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 764 * 765 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 766 * HEARTBEAT ACK, etc.) to the same destination transport 767 * address from which it received the DATA or control chunk to 768 * which it is replying. This rule should also be followed if 769 * the endpoint is bundling DATA chunks together with the 770 * reply chunk. 771 * 772 * However, when acknowledging multiple DATA chunks received 773 * in packets from different source addresses in a single 774 * SACK, the SACK chunk may be transmitted to one of the 775 * destination transport addresses from which the DATA or 776 * control chunks being acknowledged were received. 777 * 778 * [BUG: We do not implement the following paragraph. 779 * Perhaps we should remember the last transport we used for a 780 * SACK and avoid that (if possible) if we have seen any 781 * duplicates. --piggy] 782 * 783 * When a receiver of a duplicate DATA chunk sends a SACK to a 784 * multi- homed endpoint it MAY be beneficial to vary the 785 * destination address and not use the source address of the 786 * DATA chunk. The reason being that receiving a duplicate 787 * from a multi-homed endpoint might indicate that the return 788 * path (as specified in the source address of the DATA chunk) 789 * for the SACK is broken. 790 * 791 * [Send to the address from which we last received a DATA chunk.] 792 */ 793 retval->transport = asoc->peer.last_data_from; 794 795 retval->subh.sack_hdr = 796 sctp_addto_chunk(retval, sizeof(sack), &sack); 797 798 /* Add the gap ack block information. */ 799 if (num_gabs) 800 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, 801 gabs); 802 803 /* Add the duplicate TSN information. */ 804 if (num_dup_tsns) 805 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, 806 sctp_tsnmap_get_dups(map)); 807 808 nodata: 809 return retval; 810 } 811 812 /* Make a SHUTDOWN chunk. */ 813 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 814 const struct sctp_chunk *chunk) 815 { 816 struct sctp_chunk *retval; 817 sctp_shutdownhdr_t shut; 818 __u32 ctsn; 819 820 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 821 shut.cum_tsn_ack = htonl(ctsn); 822 823 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN, 0, 824 sizeof(sctp_shutdownhdr_t)); 825 if (!retval) 826 goto nodata; 827 828 retval->subh.shutdown_hdr = 829 sctp_addto_chunk(retval, sizeof(shut), &shut); 830 831 if (chunk) 832 retval->transport = chunk->transport; 833 nodata: 834 return retval; 835 } 836 837 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 838 const struct sctp_chunk *chunk) 839 { 840 struct sctp_chunk *retval; 841 842 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0); 843 844 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 845 * 846 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 847 * HEARTBEAT ACK, * etc.) to the same destination transport 848 * address from which it * received the DATA or control chunk 849 * to which it is replying. 850 * 851 * [ACK back to where the SHUTDOWN came from.] 852 */ 853 if (retval && chunk) 854 retval->transport = chunk->transport; 855 856 return retval; 857 } 858 859 struct sctp_chunk *sctp_make_shutdown_complete( 860 const struct sctp_association *asoc, 861 const struct sctp_chunk *chunk) 862 { 863 struct sctp_chunk *retval; 864 __u8 flags = 0; 865 866 /* Set the T-bit if we have no association (vtag will be 867 * reflected) 868 */ 869 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; 870 871 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0); 872 873 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 874 * 875 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 876 * HEARTBEAT ACK, * etc.) to the same destination transport 877 * address from which it * received the DATA or control chunk 878 * to which it is replying. 879 * 880 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK 881 * came from.] 882 */ 883 if (retval && chunk) 884 retval->transport = chunk->transport; 885 886 return retval; 887 } 888 889 /* Create an ABORT. Note that we set the T bit if we have no 890 * association, except when responding to an INIT (sctpimpguide 2.41). 891 */ 892 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 893 const struct sctp_chunk *chunk, 894 const size_t hint) 895 { 896 struct sctp_chunk *retval; 897 __u8 flags = 0; 898 899 /* Set the T-bit if we have no association and 'chunk' is not 900 * an INIT (vtag will be reflected). 901 */ 902 if (!asoc) { 903 if (chunk && chunk->chunk_hdr && 904 chunk->chunk_hdr->type == SCTP_CID_INIT) 905 flags = 0; 906 else 907 flags = SCTP_CHUNK_FLAG_T; 908 } 909 910 retval = sctp_make_chunk(asoc, SCTP_CID_ABORT, flags, hint); 911 912 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 913 * 914 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 915 * HEARTBEAT ACK, * etc.) to the same destination transport 916 * address from which it * received the DATA or control chunk 917 * to which it is replying. 918 * 919 * [ABORT back to where the offender came from.] 920 */ 921 if (retval && chunk) 922 retval->transport = chunk->transport; 923 924 return retval; 925 } 926 927 /* Helper to create ABORT with a NO_USER_DATA error. */ 928 struct sctp_chunk *sctp_make_abort_no_data( 929 const struct sctp_association *asoc, 930 const struct sctp_chunk *chunk, __u32 tsn) 931 { 932 struct sctp_chunk *retval; 933 __be32 payload; 934 935 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) 936 + sizeof(tsn)); 937 938 if (!retval) 939 goto no_mem; 940 941 /* Put the tsn back into network byte order. */ 942 payload = htonl(tsn); 943 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload)); 944 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload); 945 946 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 947 * 948 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 949 * HEARTBEAT ACK, * etc.) to the same destination transport 950 * address from which it * received the DATA or control chunk 951 * to which it is replying. 952 * 953 * [ABORT back to where the offender came from.] 954 */ 955 if (chunk) 956 retval->transport = chunk->transport; 957 958 no_mem: 959 return retval; 960 } 961 962 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ 963 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 964 const struct msghdr *msg, 965 size_t paylen) 966 { 967 struct sctp_chunk *retval; 968 void *payload = NULL; 969 int err; 970 971 retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen); 972 if (!retval) 973 goto err_chunk; 974 975 if (paylen) { 976 /* Put the msg_iov together into payload. */ 977 payload = kmalloc(paylen, GFP_KERNEL); 978 if (!payload) 979 goto err_payload; 980 981 err = memcpy_fromiovec(payload, msg->msg_iov, paylen); 982 if (err < 0) 983 goto err_copy; 984 } 985 986 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); 987 sctp_addto_chunk(retval, paylen, payload); 988 989 if (paylen) 990 kfree(payload); 991 992 return retval; 993 994 err_copy: 995 kfree(payload); 996 err_payload: 997 sctp_chunk_free(retval); 998 retval = NULL; 999 err_chunk: 1000 return retval; 1001 } 1002 1003 /* Append bytes to the end of a parameter. Will panic if chunk is not big 1004 * enough. 1005 */ 1006 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 1007 const void *data) 1008 { 1009 void *target; 1010 int chunklen = ntohs(chunk->chunk_hdr->length); 1011 1012 target = skb_put(chunk->skb, len); 1013 1014 if (data) 1015 memcpy(target, data, len); 1016 else 1017 memset(target, 0, len); 1018 1019 /* Adjust the chunk length field. */ 1020 chunk->chunk_hdr->length = htons(chunklen + len); 1021 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1022 1023 return target; 1024 } 1025 1026 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ 1027 struct sctp_chunk *sctp_make_abort_violation( 1028 const struct sctp_association *asoc, 1029 const struct sctp_chunk *chunk, 1030 const __u8 *payload, 1031 const size_t paylen) 1032 { 1033 struct sctp_chunk *retval; 1034 struct sctp_paramhdr phdr; 1035 1036 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen 1037 + sizeof(sctp_paramhdr_t)); 1038 if (!retval) 1039 goto end; 1040 1041 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen 1042 + sizeof(sctp_paramhdr_t)); 1043 1044 phdr.type = htons(chunk->chunk_hdr->type); 1045 phdr.length = chunk->chunk_hdr->length; 1046 sctp_addto_chunk(retval, paylen, payload); 1047 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr); 1048 1049 end: 1050 return retval; 1051 } 1052 1053 struct sctp_chunk *sctp_make_violation_paramlen( 1054 const struct sctp_association *asoc, 1055 const struct sctp_chunk *chunk, 1056 struct sctp_paramhdr *param) 1057 { 1058 struct sctp_chunk *retval; 1059 static const char error[] = "The following parameter had invalid length:"; 1060 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t) + 1061 sizeof(sctp_paramhdr_t); 1062 1063 retval = sctp_make_abort(asoc, chunk, payload_len); 1064 if (!retval) 1065 goto nodata; 1066 1067 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, 1068 sizeof(error) + sizeof(sctp_paramhdr_t)); 1069 sctp_addto_chunk(retval, sizeof(error), error); 1070 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), param); 1071 1072 nodata: 1073 return retval; 1074 } 1075 1076 /* Make a HEARTBEAT chunk. */ 1077 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1078 const struct sctp_transport *transport) 1079 { 1080 struct sctp_chunk *retval; 1081 sctp_sender_hb_info_t hbinfo; 1082 1083 retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT, 0, sizeof(hbinfo)); 1084 1085 if (!retval) 1086 goto nodata; 1087 1088 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; 1089 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t)); 1090 hbinfo.daddr = transport->ipaddr; 1091 hbinfo.sent_at = jiffies; 1092 hbinfo.hb_nonce = transport->hb_nonce; 1093 1094 /* Cast away the 'const', as this is just telling the chunk 1095 * what transport it belongs to. 1096 */ 1097 retval->transport = (struct sctp_transport *) transport; 1098 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo), 1099 &hbinfo); 1100 1101 nodata: 1102 return retval; 1103 } 1104 1105 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1106 const struct sctp_chunk *chunk, 1107 const void *payload, const size_t paylen) 1108 { 1109 struct sctp_chunk *retval; 1110 1111 retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen); 1112 if (!retval) 1113 goto nodata; 1114 1115 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1116 1117 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1118 * 1119 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1120 * HEARTBEAT ACK, * etc.) to the same destination transport 1121 * address from which it * received the DATA or control chunk 1122 * to which it is replying. 1123 * 1124 * [HBACK back to where the HEARTBEAT came from.] 1125 */ 1126 if (chunk) 1127 retval->transport = chunk->transport; 1128 1129 nodata: 1130 return retval; 1131 } 1132 1133 /* Create an Operation Error chunk with the specified space reserved. 1134 * This routine can be used for containing multiple causes in the chunk. 1135 */ 1136 static struct sctp_chunk *sctp_make_op_error_space( 1137 const struct sctp_association *asoc, 1138 const struct sctp_chunk *chunk, 1139 size_t size) 1140 { 1141 struct sctp_chunk *retval; 1142 1143 retval = sctp_make_chunk(asoc, SCTP_CID_ERROR, 0, 1144 sizeof(sctp_errhdr_t) + size); 1145 if (!retval) 1146 goto nodata; 1147 1148 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1149 * 1150 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1151 * HEARTBEAT ACK, etc.) to the same destination transport 1152 * address from which it received the DATA or control chunk 1153 * to which it is replying. 1154 * 1155 */ 1156 if (chunk) 1157 retval->transport = chunk->transport; 1158 1159 nodata: 1160 return retval; 1161 } 1162 1163 /* Create an Operation Error chunk of a fixed size, 1164 * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) 1165 * This is a helper function to allocate an error chunk for 1166 * for those invalid parameter codes in which we may not want 1167 * to report all the errors, if the incomming chunk is large 1168 */ 1169 static inline struct sctp_chunk *sctp_make_op_error_fixed( 1170 const struct sctp_association *asoc, 1171 const struct sctp_chunk *chunk) 1172 { 1173 size_t size = asoc ? asoc->pathmtu : 0; 1174 1175 if (!size) 1176 size = SCTP_DEFAULT_MAXSEGMENT; 1177 1178 return sctp_make_op_error_space(asoc, chunk, size); 1179 } 1180 1181 /* Create an Operation Error chunk. */ 1182 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1183 const struct sctp_chunk *chunk, 1184 __be16 cause_code, const void *payload, 1185 size_t paylen, size_t reserve_tail) 1186 { 1187 struct sctp_chunk *retval; 1188 1189 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); 1190 if (!retval) 1191 goto nodata; 1192 1193 sctp_init_cause(retval, cause_code, paylen + reserve_tail); 1194 sctp_addto_chunk(retval, paylen, payload); 1195 if (reserve_tail) 1196 sctp_addto_param(retval, reserve_tail, NULL); 1197 1198 nodata: 1199 return retval; 1200 } 1201 1202 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc) 1203 { 1204 struct sctp_chunk *retval; 1205 struct sctp_hmac *hmac_desc; 1206 struct sctp_authhdr auth_hdr; 1207 __u8 *hmac; 1208 1209 /* Get the first hmac that the peer told us to use */ 1210 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1211 if (unlikely(!hmac_desc)) 1212 return NULL; 1213 1214 retval = sctp_make_chunk(asoc, SCTP_CID_AUTH, 0, 1215 hmac_desc->hmac_len + sizeof(sctp_authhdr_t)); 1216 if (!retval) 1217 return NULL; 1218 1219 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1220 auth_hdr.shkey_id = htons(asoc->active_key_id); 1221 1222 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t), 1223 &auth_hdr); 1224 1225 hmac = skb_put(retval->skb, hmac_desc->hmac_len); 1226 memset(hmac, 0, hmac_desc->hmac_len); 1227 1228 /* Adjust the chunk header to include the empty MAC */ 1229 retval->chunk_hdr->length = 1230 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1231 retval->chunk_end = skb_tail_pointer(retval->skb); 1232 1233 return retval; 1234 } 1235 1236 1237 /******************************************************************** 1238 * 2nd Level Abstractions 1239 ********************************************************************/ 1240 1241 /* Turn an skb into a chunk. 1242 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1243 */ 1244 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1245 const struct sctp_association *asoc, 1246 struct sock *sk) 1247 { 1248 struct sctp_chunk *retval; 1249 1250 retval = kmem_cache_zalloc(sctp_chunk_cachep, GFP_ATOMIC); 1251 1252 if (!retval) 1253 goto nodata; 1254 1255 if (!sk) { 1256 SCTP_DEBUG_PRINTK("chunkifying skb %p w/o an sk\n", skb); 1257 } 1258 1259 INIT_LIST_HEAD(&retval->list); 1260 retval->skb = skb; 1261 retval->asoc = (struct sctp_association *)asoc; 1262 retval->has_tsn = 0; 1263 retval->has_ssn = 0; 1264 retval->rtt_in_progress = 0; 1265 retval->sent_at = 0; 1266 retval->singleton = 1; 1267 retval->end_of_packet = 0; 1268 retval->ecn_ce_done = 0; 1269 retval->pdiscard = 0; 1270 1271 /* sctpimpguide-05.txt Section 2.8.2 1272 * M1) Each time a new DATA chunk is transmitted 1273 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1274 * 'TSN.Missing.Report' count will be used to determine missing chunks 1275 * and when to fast retransmit. 1276 */ 1277 retval->tsn_missing_report = 0; 1278 retval->tsn_gap_acked = 0; 1279 retval->fast_retransmit = SCTP_CAN_FRTX; 1280 1281 /* If this is a fragmented message, track all fragments 1282 * of the message (for SEND_FAILED). 1283 */ 1284 retval->msg = NULL; 1285 1286 /* Polish the bead hole. */ 1287 INIT_LIST_HEAD(&retval->transmitted_list); 1288 INIT_LIST_HEAD(&retval->frag_list); 1289 SCTP_DBG_OBJCNT_INC(chunk); 1290 atomic_set(&retval->refcnt, 1); 1291 1292 nodata: 1293 return retval; 1294 } 1295 1296 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1297 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1298 union sctp_addr *dest) 1299 { 1300 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1301 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1302 } 1303 1304 /* Extract the source address from a chunk. */ 1305 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1306 { 1307 /* If we have a known transport, use that. */ 1308 if (chunk->transport) { 1309 return &chunk->transport->ipaddr; 1310 } else { 1311 /* Otherwise, extract it from the IP header. */ 1312 return &chunk->source; 1313 } 1314 } 1315 1316 /* Create a new chunk, setting the type and flags headers from the 1317 * arguments, reserving enough space for a 'paylen' byte payload. 1318 */ 1319 SCTP_STATIC 1320 struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc, 1321 __u8 type, __u8 flags, int paylen) 1322 { 1323 struct sctp_chunk *retval; 1324 sctp_chunkhdr_t *chunk_hdr; 1325 struct sk_buff *skb; 1326 struct sock *sk; 1327 1328 /* No need to allocate LL here, as this is only a chunk. */ 1329 skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen), 1330 GFP_ATOMIC); 1331 if (!skb) 1332 goto nodata; 1333 1334 /* Make room for the chunk header. */ 1335 chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t)); 1336 chunk_hdr->type = type; 1337 chunk_hdr->flags = flags; 1338 chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t)); 1339 1340 sk = asoc ? asoc->base.sk : NULL; 1341 retval = sctp_chunkify(skb, asoc, sk); 1342 if (!retval) { 1343 kfree_skb(skb); 1344 goto nodata; 1345 } 1346 1347 retval->chunk_hdr = chunk_hdr; 1348 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr); 1349 1350 /* Determine if the chunk needs to be authenticated */ 1351 if (sctp_auth_send_cid(type, asoc)) 1352 retval->auth = 1; 1353 1354 /* Set the skb to the belonging sock for accounting. */ 1355 skb->sk = sk; 1356 1357 return retval; 1358 nodata: 1359 return NULL; 1360 } 1361 1362 1363 /* Release the memory occupied by a chunk. */ 1364 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1365 { 1366 BUG_ON(!list_empty(&chunk->list)); 1367 list_del_init(&chunk->transmitted_list); 1368 1369 /* Free the chunk skb data and the SCTP_chunk stub itself. */ 1370 dev_kfree_skb(chunk->skb); 1371 1372 SCTP_DBG_OBJCNT_DEC(chunk); 1373 kmem_cache_free(sctp_chunk_cachep, chunk); 1374 } 1375 1376 /* Possibly, free the chunk. */ 1377 void sctp_chunk_free(struct sctp_chunk *chunk) 1378 { 1379 /* Release our reference on the message tracker. */ 1380 if (chunk->msg) 1381 sctp_datamsg_put(chunk->msg); 1382 1383 sctp_chunk_put(chunk); 1384 } 1385 1386 /* Grab a reference to the chunk. */ 1387 void sctp_chunk_hold(struct sctp_chunk *ch) 1388 { 1389 atomic_inc(&ch->refcnt); 1390 } 1391 1392 /* Release a reference to the chunk. */ 1393 void sctp_chunk_put(struct sctp_chunk *ch) 1394 { 1395 if (atomic_dec_and_test(&ch->refcnt)) 1396 sctp_chunk_destroy(ch); 1397 } 1398 1399 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1400 * enough. 1401 */ 1402 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1403 { 1404 void *target; 1405 void *padding; 1406 int chunklen = ntohs(chunk->chunk_hdr->length); 1407 int padlen = WORD_ROUND(chunklen) - chunklen; 1408 1409 padding = skb_put(chunk->skb, padlen); 1410 target = skb_put(chunk->skb, len); 1411 1412 memset(padding, 0, padlen); 1413 memcpy(target, data, len); 1414 1415 /* Adjust the chunk length field. */ 1416 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1417 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1418 1419 return target; 1420 } 1421 1422 /* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient 1423 * space in the chunk 1424 */ 1425 void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk, 1426 int len, const void *data) 1427 { 1428 if (skb_tailroom(chunk->skb) >= len) 1429 return sctp_addto_chunk(chunk, len, data); 1430 else 1431 return NULL; 1432 } 1433 1434 /* Append bytes from user space to the end of a chunk. Will panic if 1435 * chunk is not big enough. 1436 * Returns a kernel err value. 1437 */ 1438 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len, 1439 struct iovec *data) 1440 { 1441 __u8 *target; 1442 int err = 0; 1443 1444 /* Make room in chunk for data. */ 1445 target = skb_put(chunk->skb, len); 1446 1447 /* Copy data (whole iovec) into chunk */ 1448 if ((err = memcpy_fromiovecend(target, data, off, len))) 1449 goto out; 1450 1451 /* Adjust the chunk length field. */ 1452 chunk->chunk_hdr->length = 1453 htons(ntohs(chunk->chunk_hdr->length) + len); 1454 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1455 1456 out: 1457 return err; 1458 } 1459 1460 /* Helper function to assign a TSN if needed. This assumes that both 1461 * the data_hdr and association have already been assigned. 1462 */ 1463 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1464 { 1465 struct sctp_datamsg *msg; 1466 struct sctp_chunk *lchunk; 1467 struct sctp_stream *stream; 1468 __u16 ssn; 1469 __u16 sid; 1470 1471 if (chunk->has_ssn) 1472 return; 1473 1474 /* All fragments will be on the same stream */ 1475 sid = ntohs(chunk->subh.data_hdr->stream); 1476 stream = &chunk->asoc->ssnmap->out; 1477 1478 /* Now assign the sequence number to the entire message. 1479 * All fragments must have the same stream sequence number. 1480 */ 1481 msg = chunk->msg; 1482 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1483 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1484 ssn = 0; 1485 } else { 1486 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1487 ssn = sctp_ssn_next(stream, sid); 1488 else 1489 ssn = sctp_ssn_peek(stream, sid); 1490 } 1491 1492 lchunk->subh.data_hdr->ssn = htons(ssn); 1493 lchunk->has_ssn = 1; 1494 } 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_tsn(struct sctp_chunk *chunk) 1501 { 1502 if (!chunk->has_tsn) { 1503 /* This is the last possible instant to 1504 * assign a TSN. 1505 */ 1506 chunk->subh.data_hdr->tsn = 1507 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1508 chunk->has_tsn = 1; 1509 } 1510 } 1511 1512 /* Create a CLOSED association to use with an incoming packet. */ 1513 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1514 struct sctp_chunk *chunk, 1515 gfp_t gfp) 1516 { 1517 struct sctp_association *asoc; 1518 struct sk_buff *skb; 1519 sctp_scope_t scope; 1520 struct sctp_af *af; 1521 1522 /* Create the bare association. */ 1523 scope = sctp_scope(sctp_source(chunk)); 1524 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1525 if (!asoc) 1526 goto nodata; 1527 asoc->temp = 1; 1528 skb = chunk->skb; 1529 /* Create an entry for the source address of the packet. */ 1530 af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version)); 1531 if (unlikely(!af)) 1532 goto fail; 1533 af->from_skb(&asoc->c.peer_addr, skb, 1); 1534 nodata: 1535 return asoc; 1536 1537 fail: 1538 sctp_association_free(asoc); 1539 return NULL; 1540 } 1541 1542 /* Build a cookie representing asoc. 1543 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1544 */ 1545 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, 1546 const struct sctp_association *asoc, 1547 const struct sctp_chunk *init_chunk, 1548 int *cookie_len, 1549 const __u8 *raw_addrs, int addrs_len) 1550 { 1551 sctp_cookie_param_t *retval; 1552 struct sctp_signed_cookie *cookie; 1553 struct scatterlist sg; 1554 int headersize, bodysize; 1555 unsigned int keylen; 1556 char *key; 1557 1558 /* Header size is static data prior to the actual cookie, including 1559 * any padding. 1560 */ 1561 headersize = sizeof(sctp_paramhdr_t) + 1562 (sizeof(struct sctp_signed_cookie) - 1563 sizeof(struct sctp_cookie)); 1564 bodysize = sizeof(struct sctp_cookie) 1565 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1566 1567 /* Pad out the cookie to a multiple to make the signature 1568 * functions simpler to write. 1569 */ 1570 if (bodysize % SCTP_COOKIE_MULTIPLE) 1571 bodysize += SCTP_COOKIE_MULTIPLE 1572 - (bodysize % SCTP_COOKIE_MULTIPLE); 1573 *cookie_len = headersize + bodysize; 1574 1575 /* Clear this memory since we are sending this data structure 1576 * out on the network. 1577 */ 1578 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1579 if (!retval) 1580 goto nodata; 1581 1582 cookie = (struct sctp_signed_cookie *) retval->body; 1583 1584 /* Set up the parameter header. */ 1585 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1586 retval->p.length = htons(*cookie_len); 1587 1588 /* Copy the cookie part of the association itself. */ 1589 cookie->c = asoc->c; 1590 /* Save the raw address list length in the cookie. */ 1591 cookie->c.raw_addr_list_len = addrs_len; 1592 1593 /* Remember PR-SCTP capability. */ 1594 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1595 1596 /* Save adaptation indication in the cookie. */ 1597 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1598 1599 /* Set an expiration time for the cookie. */ 1600 do_gettimeofday(&cookie->c.expiration); 1601 TIMEVAL_ADD(asoc->cookie_life, cookie->c.expiration); 1602 1603 /* Copy the peer's init packet. */ 1604 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr, 1605 ntohs(init_chunk->chunk_hdr->length)); 1606 1607 /* Copy the raw local address list of the association. */ 1608 memcpy((__u8 *)&cookie->c.peer_init[0] + 1609 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1610 1611 if (sctp_sk(ep->base.sk)->hmac) { 1612 struct hash_desc desc; 1613 1614 /* Sign the message. */ 1615 sg_init_one(&sg, &cookie->c, bodysize); 1616 keylen = SCTP_SECRET_SIZE; 1617 key = (char *)ep->secret_key[ep->current_key]; 1618 desc.tfm = sctp_sk(ep->base.sk)->hmac; 1619 desc.flags = 0; 1620 1621 if (crypto_hash_setkey(desc.tfm, key, keylen) || 1622 crypto_hash_digest(&desc, &sg, bodysize, cookie->signature)) 1623 goto free_cookie; 1624 } 1625 1626 return retval; 1627 1628 free_cookie: 1629 kfree(retval); 1630 nodata: 1631 *cookie_len = 0; 1632 return NULL; 1633 } 1634 1635 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1636 struct sctp_association *sctp_unpack_cookie( 1637 const struct sctp_endpoint *ep, 1638 const struct sctp_association *asoc, 1639 struct sctp_chunk *chunk, gfp_t gfp, 1640 int *error, struct sctp_chunk **errp) 1641 { 1642 struct sctp_association *retval = NULL; 1643 struct sctp_signed_cookie *cookie; 1644 struct sctp_cookie *bear_cookie; 1645 int headersize, bodysize, fixed_size; 1646 __u8 *digest = ep->digest; 1647 struct scatterlist sg; 1648 unsigned int keylen, len; 1649 char *key; 1650 sctp_scope_t scope; 1651 struct sk_buff *skb = chunk->skb; 1652 struct timeval tv; 1653 struct hash_desc desc; 1654 1655 /* Header size is static data prior to the actual cookie, including 1656 * any padding. 1657 */ 1658 headersize = sizeof(sctp_chunkhdr_t) + 1659 (sizeof(struct sctp_signed_cookie) - 1660 sizeof(struct sctp_cookie)); 1661 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1662 fixed_size = headersize + sizeof(struct sctp_cookie); 1663 1664 /* Verify that the chunk looks like it even has a cookie. 1665 * There must be enough room for our cookie and our peer's 1666 * INIT chunk. 1667 */ 1668 len = ntohs(chunk->chunk_hdr->length); 1669 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1670 goto malformed; 1671 1672 /* Verify that the cookie has been padded out. */ 1673 if (bodysize % SCTP_COOKIE_MULTIPLE) 1674 goto malformed; 1675 1676 /* Process the cookie. */ 1677 cookie = chunk->subh.cookie_hdr; 1678 bear_cookie = &cookie->c; 1679 1680 if (!sctp_sk(ep->base.sk)->hmac) 1681 goto no_hmac; 1682 1683 /* Check the signature. */ 1684 keylen = SCTP_SECRET_SIZE; 1685 sg_init_one(&sg, bear_cookie, bodysize); 1686 key = (char *)ep->secret_key[ep->current_key]; 1687 desc.tfm = sctp_sk(ep->base.sk)->hmac; 1688 desc.flags = 0; 1689 1690 memset(digest, 0x00, SCTP_SIGNATURE_SIZE); 1691 if (crypto_hash_setkey(desc.tfm, key, keylen) || 1692 crypto_hash_digest(&desc, &sg, bodysize, digest)) { 1693 *error = -SCTP_IERROR_NOMEM; 1694 goto fail; 1695 } 1696 1697 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1698 /* Try the previous key. */ 1699 key = (char *)ep->secret_key[ep->last_key]; 1700 memset(digest, 0x00, SCTP_SIGNATURE_SIZE); 1701 if (crypto_hash_setkey(desc.tfm, key, keylen) || 1702 crypto_hash_digest(&desc, &sg, bodysize, digest)) { 1703 *error = -SCTP_IERROR_NOMEM; 1704 goto fail; 1705 } 1706 1707 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1708 /* Yikes! Still bad signature! */ 1709 *error = -SCTP_IERROR_BAD_SIG; 1710 goto fail; 1711 } 1712 } 1713 1714 no_hmac: 1715 /* IG Section 2.35.2: 1716 * 3) Compare the port numbers and the verification tag contained 1717 * within the COOKIE ECHO chunk to the actual port numbers and the 1718 * verification tag within the SCTP common header of the received 1719 * packet. If these values do not match the packet MUST be silently 1720 * discarded, 1721 */ 1722 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1723 *error = -SCTP_IERROR_BAD_TAG; 1724 goto fail; 1725 } 1726 1727 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1728 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1729 *error = -SCTP_IERROR_BAD_PORTS; 1730 goto fail; 1731 } 1732 1733 /* Check to see if the cookie is stale. If there is already 1734 * an association, there is no need to check cookie's expiration 1735 * for init collision case of lost COOKIE ACK. 1736 * If skb has been timestamped, then use the stamp, otherwise 1737 * use current time. This introduces a small possibility that 1738 * that a cookie may be considered expired, but his would only slow 1739 * down the new association establishment instead of every packet. 1740 */ 1741 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1742 skb_get_timestamp(skb, &tv); 1743 else 1744 do_gettimeofday(&tv); 1745 1746 if (!asoc && tv_lt(bear_cookie->expiration, tv)) { 1747 /* 1748 * Section 3.3.10.3 Stale Cookie Error (3) 1749 * 1750 * Cause of error 1751 * --------------- 1752 * Stale Cookie Error: Indicates the receipt of a valid State 1753 * Cookie that has expired. 1754 */ 1755 len = ntohs(chunk->chunk_hdr->length); 1756 *errp = sctp_make_op_error_space(asoc, chunk, len); 1757 if (*errp) { 1758 suseconds_t usecs = (tv.tv_sec - 1759 bear_cookie->expiration.tv_sec) * 1000000L + 1760 tv.tv_usec - bear_cookie->expiration.tv_usec; 1761 __be32 n = htonl(usecs); 1762 1763 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE, 1764 sizeof(n)); 1765 sctp_addto_chunk(*errp, sizeof(n), &n); 1766 *error = -SCTP_IERROR_STALE_COOKIE; 1767 } else 1768 *error = -SCTP_IERROR_NOMEM; 1769 1770 goto fail; 1771 } 1772 1773 /* Make a new base association. */ 1774 scope = sctp_scope(sctp_source(chunk)); 1775 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1776 if (!retval) { 1777 *error = -SCTP_IERROR_NOMEM; 1778 goto fail; 1779 } 1780 1781 /* Set up our peer's port number. */ 1782 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1783 1784 /* Populate the association from the cookie. */ 1785 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1786 1787 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1788 GFP_ATOMIC) < 0) { 1789 *error = -SCTP_IERROR_NOMEM; 1790 goto fail; 1791 } 1792 1793 /* Also, add the destination address. */ 1794 if (list_empty(&retval->base.bind_addr.address_list)) { 1795 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1796 SCTP_ADDR_SRC, GFP_ATOMIC); 1797 } 1798 1799 retval->next_tsn = retval->c.initial_tsn; 1800 retval->ctsn_ack_point = retval->next_tsn - 1; 1801 retval->addip_serial = retval->c.initial_tsn; 1802 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1803 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1804 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1805 1806 /* The INIT stuff will be done by the side effects. */ 1807 return retval; 1808 1809 fail: 1810 if (retval) 1811 sctp_association_free(retval); 1812 1813 return NULL; 1814 1815 malformed: 1816 /* Yikes! The packet is either corrupt or deliberately 1817 * malformed. 1818 */ 1819 *error = -SCTP_IERROR_MALFORMED; 1820 goto fail; 1821 } 1822 1823 /******************************************************************** 1824 * 3rd Level Abstractions 1825 ********************************************************************/ 1826 1827 struct __sctp_missing { 1828 __be32 num_missing; 1829 __be16 type; 1830 } __packed; 1831 1832 /* 1833 * Report a missing mandatory parameter. 1834 */ 1835 static int sctp_process_missing_param(const struct sctp_association *asoc, 1836 sctp_param_t paramtype, 1837 struct sctp_chunk *chunk, 1838 struct sctp_chunk **errp) 1839 { 1840 struct __sctp_missing report; 1841 __u16 len; 1842 1843 len = WORD_ROUND(sizeof(report)); 1844 1845 /* Make an ERROR chunk, preparing enough room for 1846 * returning multiple unknown parameters. 1847 */ 1848 if (!*errp) 1849 *errp = sctp_make_op_error_space(asoc, chunk, len); 1850 1851 if (*errp) { 1852 report.num_missing = htonl(1); 1853 report.type = paramtype; 1854 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1855 sizeof(report)); 1856 sctp_addto_chunk(*errp, sizeof(report), &report); 1857 } 1858 1859 /* Stop processing this chunk. */ 1860 return 0; 1861 } 1862 1863 /* Report an Invalid Mandatory Parameter. */ 1864 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1865 struct sctp_chunk *chunk, 1866 struct sctp_chunk **errp) 1867 { 1868 /* Invalid Mandatory Parameter Error has no payload. */ 1869 1870 if (!*errp) 1871 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1872 1873 if (*errp) 1874 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1875 1876 /* Stop processing this chunk. */ 1877 return 0; 1878 } 1879 1880 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1881 struct sctp_paramhdr *param, 1882 const struct sctp_chunk *chunk, 1883 struct sctp_chunk **errp) 1884 { 1885 /* This is a fatal error. Any accumulated non-fatal errors are 1886 * not reported. 1887 */ 1888 if (*errp) 1889 sctp_chunk_free(*errp); 1890 1891 /* Create an error chunk and fill it in with our payload. */ 1892 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1893 1894 return 0; 1895 } 1896 1897 1898 /* Do not attempt to handle the HOST_NAME parm. However, do 1899 * send back an indicator to the peer. 1900 */ 1901 static int sctp_process_hn_param(const struct sctp_association *asoc, 1902 union sctp_params param, 1903 struct sctp_chunk *chunk, 1904 struct sctp_chunk **errp) 1905 { 1906 __u16 len = ntohs(param.p->length); 1907 1908 /* Processing of the HOST_NAME parameter will generate an 1909 * ABORT. If we've accumulated any non-fatal errors, they 1910 * would be unrecognized parameters and we should not include 1911 * them in the ABORT. 1912 */ 1913 if (*errp) 1914 sctp_chunk_free(*errp); 1915 1916 *errp = sctp_make_op_error_space(asoc, chunk, len); 1917 1918 if (*errp) { 1919 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len); 1920 sctp_addto_chunk(*errp, len, param.v); 1921 } 1922 1923 /* Stop processing this chunk. */ 1924 return 0; 1925 } 1926 1927 static int sctp_verify_ext_param(union sctp_params param) 1928 { 1929 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 1930 int have_auth = 0; 1931 int have_asconf = 0; 1932 int i; 1933 1934 for (i = 0; i < num_ext; i++) { 1935 switch (param.ext->chunks[i]) { 1936 case SCTP_CID_AUTH: 1937 have_auth = 1; 1938 break; 1939 case SCTP_CID_ASCONF: 1940 case SCTP_CID_ASCONF_ACK: 1941 have_asconf = 1; 1942 break; 1943 } 1944 } 1945 1946 /* ADD-IP Security: The draft requires us to ABORT or ignore the 1947 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 1948 * only if ADD-IP is turned on and we are not backward-compatible 1949 * mode. 1950 */ 1951 if (sctp_addip_noauth) 1952 return 1; 1953 1954 if (sctp_addip_enable && !have_auth && have_asconf) 1955 return 0; 1956 1957 return 1; 1958 } 1959 1960 static void sctp_process_ext_param(struct sctp_association *asoc, 1961 union sctp_params param) 1962 { 1963 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 1964 int i; 1965 1966 for (i = 0; i < num_ext; i++) { 1967 switch (param.ext->chunks[i]) { 1968 case SCTP_CID_FWD_TSN: 1969 if (sctp_prsctp_enable && 1970 !asoc->peer.prsctp_capable) 1971 asoc->peer.prsctp_capable = 1; 1972 break; 1973 case SCTP_CID_AUTH: 1974 /* if the peer reports AUTH, assume that he 1975 * supports AUTH. 1976 */ 1977 if (sctp_auth_enable) 1978 asoc->peer.auth_capable = 1; 1979 break; 1980 case SCTP_CID_ASCONF: 1981 case SCTP_CID_ASCONF_ACK: 1982 if (sctp_addip_enable) 1983 asoc->peer.asconf_capable = 1; 1984 break; 1985 default: 1986 break; 1987 } 1988 } 1989 } 1990 1991 /* RFC 3.2.1 & the Implementers Guide 2.2. 1992 * 1993 * The Parameter Types are encoded such that the 1994 * highest-order two bits specify the action that must be 1995 * taken if the processing endpoint does not recognize the 1996 * Parameter Type. 1997 * 1998 * 00 - Stop processing this parameter; do not process any further 1999 * parameters within this chunk 2000 * 2001 * 01 - Stop processing this parameter, do not process any further 2002 * parameters within this chunk, and report the unrecognized 2003 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2004 * 2005 * 10 - Skip this parameter and continue processing. 2006 * 2007 * 11 - Skip this parameter and continue processing but 2008 * report the unrecognized parameter in an 2009 * 'Unrecognized Parameter' ERROR chunk. 2010 * 2011 * Return value: 2012 * SCTP_IERROR_NO_ERROR - continue with the chunk 2013 * SCTP_IERROR_ERROR - stop and report an error. 2014 * SCTP_IERROR_NOMEME - out of memory. 2015 */ 2016 static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc, 2017 union sctp_params param, 2018 struct sctp_chunk *chunk, 2019 struct sctp_chunk **errp) 2020 { 2021 int retval = SCTP_IERROR_NO_ERROR; 2022 2023 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2024 case SCTP_PARAM_ACTION_DISCARD: 2025 retval = SCTP_IERROR_ERROR; 2026 break; 2027 case SCTP_PARAM_ACTION_SKIP: 2028 break; 2029 case SCTP_PARAM_ACTION_DISCARD_ERR: 2030 retval = SCTP_IERROR_ERROR; 2031 /* Fall through */ 2032 case SCTP_PARAM_ACTION_SKIP_ERR: 2033 /* Make an ERROR chunk, preparing enough room for 2034 * returning multiple unknown parameters. 2035 */ 2036 if (NULL == *errp) 2037 *errp = sctp_make_op_error_fixed(asoc, chunk); 2038 2039 if (*errp) { 2040 if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2041 WORD_ROUND(ntohs(param.p->length)))) 2042 sctp_addto_chunk_fixed(*errp, 2043 WORD_ROUND(ntohs(param.p->length)), 2044 param.v); 2045 } else { 2046 /* If there is no memory for generating the ERROR 2047 * report as specified, an ABORT will be triggered 2048 * to the peer and the association won't be 2049 * established. 2050 */ 2051 retval = SCTP_IERROR_NOMEM; 2052 } 2053 break; 2054 default: 2055 break; 2056 } 2057 2058 return retval; 2059 } 2060 2061 /* Verify variable length parameters 2062 * Return values: 2063 * SCTP_IERROR_ABORT - trigger an ABORT 2064 * SCTP_IERROR_NOMEM - out of memory (abort) 2065 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2066 * SCTP_IERROR_NO_ERROR - continue with the chunk 2067 */ 2068 static sctp_ierror_t sctp_verify_param(const struct sctp_association *asoc, 2069 union sctp_params param, 2070 sctp_cid_t cid, 2071 struct sctp_chunk *chunk, 2072 struct sctp_chunk **err_chunk) 2073 { 2074 struct sctp_hmac_algo_param *hmacs; 2075 int retval = SCTP_IERROR_NO_ERROR; 2076 __u16 n_elt, id = 0; 2077 int i; 2078 2079 /* FIXME - This routine is not looking at each parameter per the 2080 * chunk type, i.e., unrecognized parameters should be further 2081 * identified based on the chunk id. 2082 */ 2083 2084 switch (param.p->type) { 2085 case SCTP_PARAM_IPV4_ADDRESS: 2086 case SCTP_PARAM_IPV6_ADDRESS: 2087 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2088 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2089 case SCTP_PARAM_STATE_COOKIE: 2090 case SCTP_PARAM_HEARTBEAT_INFO: 2091 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2092 case SCTP_PARAM_ECN_CAPABLE: 2093 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2094 break; 2095 2096 case SCTP_PARAM_SUPPORTED_EXT: 2097 if (!sctp_verify_ext_param(param)) 2098 return SCTP_IERROR_ABORT; 2099 break; 2100 2101 case SCTP_PARAM_SET_PRIMARY: 2102 if (sctp_addip_enable) 2103 break; 2104 goto fallthrough; 2105 2106 case SCTP_PARAM_HOST_NAME_ADDRESS: 2107 /* Tell the peer, we won't support this param. */ 2108 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2109 retval = SCTP_IERROR_ABORT; 2110 break; 2111 2112 case SCTP_PARAM_FWD_TSN_SUPPORT: 2113 if (sctp_prsctp_enable) 2114 break; 2115 goto fallthrough; 2116 2117 case SCTP_PARAM_RANDOM: 2118 if (!sctp_auth_enable) 2119 goto fallthrough; 2120 2121 /* SCTP-AUTH: Secion 6.1 2122 * If the random number is not 32 byte long the association 2123 * MUST be aborted. The ABORT chunk SHOULD contain the error 2124 * cause 'Protocol Violation'. 2125 */ 2126 if (SCTP_AUTH_RANDOM_LENGTH != 2127 ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) { 2128 sctp_process_inv_paramlength(asoc, param.p, 2129 chunk, err_chunk); 2130 retval = SCTP_IERROR_ABORT; 2131 } 2132 break; 2133 2134 case SCTP_PARAM_CHUNKS: 2135 if (!sctp_auth_enable) 2136 goto fallthrough; 2137 2138 /* SCTP-AUTH: Section 3.2 2139 * The CHUNKS parameter MUST be included once in the INIT or 2140 * INIT-ACK chunk if the sender wants to receive authenticated 2141 * chunks. Its maximum length is 260 bytes. 2142 */ 2143 if (260 < ntohs(param.p->length)) { 2144 sctp_process_inv_paramlength(asoc, param.p, 2145 chunk, err_chunk); 2146 retval = SCTP_IERROR_ABORT; 2147 } 2148 break; 2149 2150 case SCTP_PARAM_HMAC_ALGO: 2151 if (!sctp_auth_enable) 2152 goto fallthrough; 2153 2154 hmacs = (struct sctp_hmac_algo_param *)param.p; 2155 n_elt = (ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) >> 1; 2156 2157 /* SCTP-AUTH: Section 6.1 2158 * The HMAC algorithm based on SHA-1 MUST be supported and 2159 * included in the HMAC-ALGO parameter. 2160 */ 2161 for (i = 0; i < n_elt; i++) { 2162 id = ntohs(hmacs->hmac_ids[i]); 2163 2164 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2165 break; 2166 } 2167 2168 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2169 sctp_process_inv_paramlength(asoc, param.p, chunk, 2170 err_chunk); 2171 retval = SCTP_IERROR_ABORT; 2172 } 2173 break; 2174 fallthrough: 2175 default: 2176 SCTP_DEBUG_PRINTK("Unrecognized param: %d for chunk %d.\n", 2177 ntohs(param.p->type), cid); 2178 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2179 break; 2180 } 2181 return retval; 2182 } 2183 2184 /* Verify the INIT packet before we process it. */ 2185 int sctp_verify_init(const struct sctp_association *asoc, 2186 sctp_cid_t cid, 2187 sctp_init_chunk_t *peer_init, 2188 struct sctp_chunk *chunk, 2189 struct sctp_chunk **errp) 2190 { 2191 union sctp_params param; 2192 int has_cookie = 0; 2193 int result; 2194 2195 /* Verify stream values are non-zero. */ 2196 if ((0 == peer_init->init_hdr.num_outbound_streams) || 2197 (0 == peer_init->init_hdr.num_inbound_streams) || 2198 (0 == peer_init->init_hdr.init_tag) || 2199 (SCTP_DEFAULT_MINWINDOW > ntohl(peer_init->init_hdr.a_rwnd))) { 2200 2201 return sctp_process_inv_mandatory(asoc, chunk, errp); 2202 } 2203 2204 /* Check for missing mandatory parameters. */ 2205 sctp_walk_params(param, peer_init, init_hdr.params) { 2206 2207 if (SCTP_PARAM_STATE_COOKIE == param.p->type) 2208 has_cookie = 1; 2209 2210 } /* for (loop through all parameters) */ 2211 2212 /* There is a possibility that a parameter length was bad and 2213 * in that case we would have stoped walking the parameters. 2214 * The current param.p would point at the bad one. 2215 * Current consensus on the mailing list is to generate a PROTOCOL 2216 * VIOLATION error. We build the ERROR chunk here and let the normal 2217 * error handling code build and send the packet. 2218 */ 2219 if (param.v != (void*)chunk->chunk_end) 2220 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2221 2222 /* The only missing mandatory param possible today is 2223 * the state cookie for an INIT-ACK chunk. 2224 */ 2225 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2226 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2227 chunk, errp); 2228 2229 /* Verify all the variable length parameters */ 2230 sctp_walk_params(param, peer_init, init_hdr.params) { 2231 2232 result = sctp_verify_param(asoc, param, cid, chunk, errp); 2233 switch (result) { 2234 case SCTP_IERROR_ABORT: 2235 case SCTP_IERROR_NOMEM: 2236 return 0; 2237 case SCTP_IERROR_ERROR: 2238 return 1; 2239 case SCTP_IERROR_NO_ERROR: 2240 default: 2241 break; 2242 } 2243 2244 } /* for (loop through all parameters) */ 2245 2246 return 1; 2247 } 2248 2249 /* Unpack the parameters in an INIT packet into an association. 2250 * Returns 0 on failure, else success. 2251 * FIXME: This is an association method. 2252 */ 2253 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2254 const union sctp_addr *peer_addr, 2255 sctp_init_chunk_t *peer_init, gfp_t gfp) 2256 { 2257 union sctp_params param; 2258 struct sctp_transport *transport; 2259 struct list_head *pos, *temp; 2260 struct sctp_af *af; 2261 union sctp_addr addr; 2262 char *cookie; 2263 int src_match = 0; 2264 2265 /* We must include the address that the INIT packet came from. 2266 * This is the only address that matters for an INIT packet. 2267 * When processing a COOKIE ECHO, we retrieve the from address 2268 * of the INIT from the cookie. 2269 */ 2270 2271 /* This implementation defaults to making the first transport 2272 * added as the primary transport. The source address seems to 2273 * be a a better choice than any of the embedded addresses. 2274 */ 2275 if(!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2276 goto nomem; 2277 2278 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2279 src_match = 1; 2280 2281 /* Process the initialization parameters. */ 2282 sctp_walk_params(param, peer_init, init_hdr.params) { 2283 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2284 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2285 af = sctp_get_af_specific(param_type2af(param.p->type)); 2286 af->from_addr_param(&addr, param.addr, 2287 chunk->sctp_hdr->source, 0); 2288 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2289 src_match = 1; 2290 } 2291 2292 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2293 goto clean_up; 2294 } 2295 2296 /* source address of chunk may not match any valid address */ 2297 if (!src_match) 2298 goto clean_up; 2299 2300 /* AUTH: After processing the parameters, make sure that we 2301 * have all the required info to potentially do authentications. 2302 */ 2303 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2304 !asoc->peer.peer_hmacs)) 2305 asoc->peer.auth_capable = 0; 2306 2307 /* In a non-backward compatible mode, if the peer claims 2308 * support for ADD-IP but not AUTH, the ADD-IP spec states 2309 * that we MUST ABORT the association. Section 6. The section 2310 * also give us an option to silently ignore the packet, which 2311 * is what we'll do here. 2312 */ 2313 if (!sctp_addip_noauth && 2314 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2315 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2316 SCTP_PARAM_DEL_IP | 2317 SCTP_PARAM_SET_PRIMARY); 2318 asoc->peer.asconf_capable = 0; 2319 goto clean_up; 2320 } 2321 2322 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2323 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2324 transport = list_entry(pos, struct sctp_transport, transports); 2325 if (transport->state == SCTP_UNKNOWN) { 2326 sctp_assoc_rm_peer(asoc, transport); 2327 } 2328 } 2329 2330 /* The fixed INIT headers are always in network byte 2331 * order. 2332 */ 2333 asoc->peer.i.init_tag = 2334 ntohl(peer_init->init_hdr.init_tag); 2335 asoc->peer.i.a_rwnd = 2336 ntohl(peer_init->init_hdr.a_rwnd); 2337 asoc->peer.i.num_outbound_streams = 2338 ntohs(peer_init->init_hdr.num_outbound_streams); 2339 asoc->peer.i.num_inbound_streams = 2340 ntohs(peer_init->init_hdr.num_inbound_streams); 2341 asoc->peer.i.initial_tsn = 2342 ntohl(peer_init->init_hdr.initial_tsn); 2343 2344 /* Apply the upper bounds for output streams based on peer's 2345 * number of inbound streams. 2346 */ 2347 if (asoc->c.sinit_num_ostreams > 2348 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2349 asoc->c.sinit_num_ostreams = 2350 ntohs(peer_init->init_hdr.num_inbound_streams); 2351 } 2352 2353 if (asoc->c.sinit_max_instreams > 2354 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2355 asoc->c.sinit_max_instreams = 2356 ntohs(peer_init->init_hdr.num_outbound_streams); 2357 } 2358 2359 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2360 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2361 2362 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2363 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2364 2365 /* Copy cookie in case we need to resend COOKIE-ECHO. */ 2366 cookie = asoc->peer.cookie; 2367 if (cookie) { 2368 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp); 2369 if (!asoc->peer.cookie) 2370 goto clean_up; 2371 } 2372 2373 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2374 * high (for example, implementations MAY use the size of the receiver 2375 * advertised window). 2376 */ 2377 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2378 transports) { 2379 transport->ssthresh = asoc->peer.i.a_rwnd; 2380 } 2381 2382 /* Set up the TSN tracking pieces. */ 2383 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2384 asoc->peer.i.initial_tsn, gfp)) 2385 goto clean_up; 2386 2387 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2388 * 2389 * The stream sequence number in all the streams shall start 2390 * from 0 when the association is established. Also, when the 2391 * stream sequence number reaches the value 65535 the next 2392 * stream sequence number shall be set to 0. 2393 */ 2394 2395 /* Allocate storage for the negotiated streams if it is not a temporary 2396 * association. 2397 */ 2398 if (!asoc->temp) { 2399 int error; 2400 2401 asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams, 2402 asoc->c.sinit_num_ostreams, gfp); 2403 if (!asoc->ssnmap) 2404 goto clean_up; 2405 2406 error = sctp_assoc_set_id(asoc, gfp); 2407 if (error) 2408 goto clean_up; 2409 } 2410 2411 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2412 * 2413 * When an endpoint has an ASCONF signaled change to be sent to the 2414 * remote endpoint it should do the following: 2415 * ... 2416 * A2) A serial number should be assigned to the Chunk. The serial 2417 * number should be a monotonically increasing number. All serial 2418 * numbers are defined to be initialized at the start of the 2419 * association to the same value as the Initial TSN. 2420 */ 2421 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2422 return 1; 2423 2424 clean_up: 2425 /* Release the transport structures. */ 2426 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2427 transport = list_entry(pos, struct sctp_transport, transports); 2428 if (transport->state != SCTP_ACTIVE) 2429 sctp_assoc_rm_peer(asoc, transport); 2430 } 2431 2432 nomem: 2433 return 0; 2434 } 2435 2436 2437 /* Update asoc with the option described in param. 2438 * 2439 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2440 * 2441 * asoc is the association to update. 2442 * param is the variable length parameter to use for update. 2443 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2444 * If the current packet is an INIT we want to minimize the amount of 2445 * work we do. In particular, we should not build transport 2446 * structures for the addresses. 2447 */ 2448 static int sctp_process_param(struct sctp_association *asoc, 2449 union sctp_params param, 2450 const union sctp_addr *peer_addr, 2451 gfp_t gfp) 2452 { 2453 union sctp_addr addr; 2454 int i; 2455 __u16 sat; 2456 int retval = 1; 2457 sctp_scope_t scope; 2458 time_t stale; 2459 struct sctp_af *af; 2460 union sctp_addr_param *addr_param; 2461 struct sctp_transport *t; 2462 2463 /* We maintain all INIT parameters in network byte order all the 2464 * time. This allows us to not worry about whether the parameters 2465 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2466 */ 2467 switch (param.p->type) { 2468 case SCTP_PARAM_IPV6_ADDRESS: 2469 if (PF_INET6 != asoc->base.sk->sk_family) 2470 break; 2471 goto do_addr_param; 2472 2473 case SCTP_PARAM_IPV4_ADDRESS: 2474 /* v4 addresses are not allowed on v6-only socket */ 2475 if (ipv6_only_sock(asoc->base.sk)) 2476 break; 2477 do_addr_param: 2478 af = sctp_get_af_specific(param_type2af(param.p->type)); 2479 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); 2480 scope = sctp_scope(peer_addr); 2481 if (sctp_in_scope(&addr, scope)) 2482 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2483 return 0; 2484 break; 2485 2486 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2487 if (!sctp_cookie_preserve_enable) 2488 break; 2489 2490 stale = ntohl(param.life->lifespan_increment); 2491 2492 /* Suggested Cookie Life span increment's unit is msec, 2493 * (1/1000sec). 2494 */ 2495 asoc->cookie_life.tv_sec += stale / 1000; 2496 asoc->cookie_life.tv_usec += (stale % 1000) * 1000; 2497 break; 2498 2499 case SCTP_PARAM_HOST_NAME_ADDRESS: 2500 SCTP_DEBUG_PRINTK("unimplemented SCTP_HOST_NAME_ADDRESS\n"); 2501 break; 2502 2503 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2504 /* Turn off the default values first so we'll know which 2505 * ones are really set by the peer. 2506 */ 2507 asoc->peer.ipv4_address = 0; 2508 asoc->peer.ipv6_address = 0; 2509 2510 /* Assume that peer supports the address family 2511 * by which it sends a packet. 2512 */ 2513 if (peer_addr->sa.sa_family == AF_INET6) 2514 asoc->peer.ipv6_address = 1; 2515 else if (peer_addr->sa.sa_family == AF_INET) 2516 asoc->peer.ipv4_address = 1; 2517 2518 /* Cycle through address types; avoid divide by 0. */ 2519 sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2520 if (sat) 2521 sat /= sizeof(__u16); 2522 2523 for (i = 0; i < sat; ++i) { 2524 switch (param.sat->types[i]) { 2525 case SCTP_PARAM_IPV4_ADDRESS: 2526 asoc->peer.ipv4_address = 1; 2527 break; 2528 2529 case SCTP_PARAM_IPV6_ADDRESS: 2530 if (PF_INET6 == asoc->base.sk->sk_family) 2531 asoc->peer.ipv6_address = 1; 2532 break; 2533 2534 case SCTP_PARAM_HOST_NAME_ADDRESS: 2535 asoc->peer.hostname_address = 1; 2536 break; 2537 2538 default: /* Just ignore anything else. */ 2539 break; 2540 } 2541 } 2542 break; 2543 2544 case SCTP_PARAM_STATE_COOKIE: 2545 asoc->peer.cookie_len = 2546 ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2547 asoc->peer.cookie = param.cookie->body; 2548 break; 2549 2550 case SCTP_PARAM_HEARTBEAT_INFO: 2551 /* Would be odd to receive, but it causes no problems. */ 2552 break; 2553 2554 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2555 /* Rejected during verify stage. */ 2556 break; 2557 2558 case SCTP_PARAM_ECN_CAPABLE: 2559 asoc->peer.ecn_capable = 1; 2560 break; 2561 2562 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2563 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2564 break; 2565 2566 case SCTP_PARAM_SET_PRIMARY: 2567 if (!sctp_addip_enable) 2568 goto fall_through; 2569 2570 addr_param = param.v + sizeof(sctp_addip_param_t); 2571 2572 af = sctp_get_af_specific(param_type2af(param.p->type)); 2573 af->from_addr_param(&addr, addr_param, 2574 htons(asoc->peer.port), 0); 2575 2576 /* if the address is invalid, we can't process it. 2577 * XXX: see spec for what to do. 2578 */ 2579 if (!af->addr_valid(&addr, NULL, NULL)) 2580 break; 2581 2582 t = sctp_assoc_lookup_paddr(asoc, &addr); 2583 if (!t) 2584 break; 2585 2586 sctp_assoc_set_primary(asoc, t); 2587 break; 2588 2589 case SCTP_PARAM_SUPPORTED_EXT: 2590 sctp_process_ext_param(asoc, param); 2591 break; 2592 2593 case SCTP_PARAM_FWD_TSN_SUPPORT: 2594 if (sctp_prsctp_enable) { 2595 asoc->peer.prsctp_capable = 1; 2596 break; 2597 } 2598 /* Fall Through */ 2599 goto fall_through; 2600 2601 case SCTP_PARAM_RANDOM: 2602 if (!sctp_auth_enable) 2603 goto fall_through; 2604 2605 /* Save peer's random parameter */ 2606 asoc->peer.peer_random = kmemdup(param.p, 2607 ntohs(param.p->length), gfp); 2608 if (!asoc->peer.peer_random) { 2609 retval = 0; 2610 break; 2611 } 2612 break; 2613 2614 case SCTP_PARAM_HMAC_ALGO: 2615 if (!sctp_auth_enable) 2616 goto fall_through; 2617 2618 /* Save peer's HMAC list */ 2619 asoc->peer.peer_hmacs = kmemdup(param.p, 2620 ntohs(param.p->length), gfp); 2621 if (!asoc->peer.peer_hmacs) { 2622 retval = 0; 2623 break; 2624 } 2625 2626 /* Set the default HMAC the peer requested*/ 2627 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2628 break; 2629 2630 case SCTP_PARAM_CHUNKS: 2631 if (!sctp_auth_enable) 2632 goto fall_through; 2633 2634 asoc->peer.peer_chunks = kmemdup(param.p, 2635 ntohs(param.p->length), gfp); 2636 if (!asoc->peer.peer_chunks) 2637 retval = 0; 2638 break; 2639 fall_through: 2640 default: 2641 /* Any unrecognized parameters should have been caught 2642 * and handled by sctp_verify_param() which should be 2643 * called prior to this routine. Simply log the error 2644 * here. 2645 */ 2646 SCTP_DEBUG_PRINTK("Ignoring param: %d for association %p.\n", 2647 ntohs(param.p->type), asoc); 2648 break; 2649 } 2650 2651 return retval; 2652 } 2653 2654 /* Select a new verification tag. */ 2655 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2656 { 2657 /* I believe that this random number generator complies with RFC1750. 2658 * A tag of 0 is reserved for special cases (e.g. INIT). 2659 */ 2660 __u32 x; 2661 2662 do { 2663 get_random_bytes(&x, sizeof(__u32)); 2664 } while (x == 0); 2665 2666 return x; 2667 } 2668 2669 /* Select an initial TSN to send during startup. */ 2670 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2671 { 2672 __u32 retval; 2673 2674 get_random_bytes(&retval, sizeof(__u32)); 2675 return retval; 2676 } 2677 2678 /* 2679 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2680 * 0 1 2 3 2681 * 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 2682 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2683 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2684 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2685 * | Serial Number | 2686 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2687 * | Address Parameter | 2688 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2689 * | ASCONF Parameter #1 | 2690 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2691 * \ \ 2692 * / .... / 2693 * \ \ 2694 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2695 * | ASCONF Parameter #N | 2696 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2697 * 2698 * Address Parameter and other parameter will not be wrapped in this function 2699 */ 2700 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2701 union sctp_addr *addr, 2702 int vparam_len) 2703 { 2704 sctp_addiphdr_t asconf; 2705 struct sctp_chunk *retval; 2706 int length = sizeof(asconf) + vparam_len; 2707 union sctp_addr_param addrparam; 2708 int addrlen; 2709 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2710 2711 addrlen = af->to_addr_param(addr, &addrparam); 2712 if (!addrlen) 2713 return NULL; 2714 length += addrlen; 2715 2716 /* Create the chunk. */ 2717 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF, 0, length); 2718 if (!retval) 2719 return NULL; 2720 2721 asconf.serial = htonl(asoc->addip_serial++); 2722 2723 retval->subh.addip_hdr = 2724 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2725 retval->param_hdr.v = 2726 sctp_addto_chunk(retval, addrlen, &addrparam); 2727 2728 return retval; 2729 } 2730 2731 /* ADDIP 2732 * 3.2.1 Add IP Address 2733 * 0 1 2 3 2734 * 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 2735 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2736 * | Type = 0xC001 | Length = Variable | 2737 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2738 * | ASCONF-Request Correlation ID | 2739 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2740 * | Address Parameter | 2741 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2742 * 2743 * 3.2.2 Delete IP Address 2744 * 0 1 2 3 2745 * 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 2746 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2747 * | Type = 0xC002 | Length = Variable | 2748 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2749 * | ASCONF-Request Correlation ID | 2750 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2751 * | Address Parameter | 2752 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2753 * 2754 */ 2755 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2756 union sctp_addr *laddr, 2757 struct sockaddr *addrs, 2758 int addrcnt, 2759 __be16 flags) 2760 { 2761 sctp_addip_param_t param; 2762 struct sctp_chunk *retval; 2763 union sctp_addr_param addr_param; 2764 union sctp_addr *addr; 2765 void *addr_buf; 2766 struct sctp_af *af; 2767 int paramlen = sizeof(param); 2768 int addr_param_len = 0; 2769 int totallen = 0; 2770 int i; 2771 int del_pickup = 0; 2772 2773 /* Get total length of all the address parameters. */ 2774 addr_buf = addrs; 2775 for (i = 0; i < addrcnt; i++) { 2776 addr = addr_buf; 2777 af = sctp_get_af_specific(addr->v4.sin_family); 2778 addr_param_len = af->to_addr_param(addr, &addr_param); 2779 2780 totallen += paramlen; 2781 totallen += addr_param_len; 2782 2783 addr_buf += af->sockaddr_len; 2784 if (asoc->asconf_addr_del_pending && !del_pickup) { 2785 /* reuse the parameter length from the same scope one */ 2786 totallen += paramlen; 2787 totallen += addr_param_len; 2788 del_pickup = 1; 2789 SCTP_DEBUG_PRINTK("mkasconf_update_ip: picked same-scope del_pending addr, totallen for all addresses is %d\n", totallen); 2790 } 2791 } 2792 2793 /* Create an asconf chunk with the required length. */ 2794 retval = sctp_make_asconf(asoc, laddr, totallen); 2795 if (!retval) 2796 return NULL; 2797 2798 /* Add the address parameters to the asconf chunk. */ 2799 addr_buf = addrs; 2800 for (i = 0; i < addrcnt; i++) { 2801 addr = addr_buf; 2802 af = sctp_get_af_specific(addr->v4.sin_family); 2803 addr_param_len = af->to_addr_param(addr, &addr_param); 2804 param.param_hdr.type = flags; 2805 param.param_hdr.length = htons(paramlen + addr_param_len); 2806 param.crr_id = i; 2807 2808 sctp_addto_chunk(retval, paramlen, ¶m); 2809 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2810 2811 addr_buf += af->sockaddr_len; 2812 } 2813 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2814 addr = asoc->asconf_addr_del_pending; 2815 af = sctp_get_af_specific(addr->v4.sin_family); 2816 addr_param_len = af->to_addr_param(addr, &addr_param); 2817 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2818 param.param_hdr.length = htons(paramlen + addr_param_len); 2819 param.crr_id = i; 2820 2821 sctp_addto_chunk(retval, paramlen, ¶m); 2822 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2823 } 2824 return retval; 2825 } 2826 2827 /* ADDIP 2828 * 3.2.4 Set Primary IP Address 2829 * 0 1 2 3 2830 * 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 2831 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2832 * | Type =0xC004 | Length = Variable | 2833 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2834 * | ASCONF-Request Correlation ID | 2835 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2836 * | Address Parameter | 2837 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2838 * 2839 * Create an ASCONF chunk with Set Primary IP address parameter. 2840 */ 2841 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2842 union sctp_addr *addr) 2843 { 2844 sctp_addip_param_t param; 2845 struct sctp_chunk *retval; 2846 int len = sizeof(param); 2847 union sctp_addr_param addrparam; 2848 int addrlen; 2849 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2850 2851 addrlen = af->to_addr_param(addr, &addrparam); 2852 if (!addrlen) 2853 return NULL; 2854 len += addrlen; 2855 2856 /* Create the chunk and make asconf header. */ 2857 retval = sctp_make_asconf(asoc, addr, len); 2858 if (!retval) 2859 return NULL; 2860 2861 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2862 param.param_hdr.length = htons(len); 2863 param.crr_id = 0; 2864 2865 sctp_addto_chunk(retval, sizeof(param), ¶m); 2866 sctp_addto_chunk(retval, addrlen, &addrparam); 2867 2868 return retval; 2869 } 2870 2871 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2872 * 0 1 2 3 2873 * 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 2874 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2875 * | Type = 0x80 | Chunk Flags | Chunk Length | 2876 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2877 * | Serial Number | 2878 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2879 * | ASCONF Parameter Response#1 | 2880 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2881 * \ \ 2882 * / .... / 2883 * \ \ 2884 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2885 * | ASCONF Parameter Response#N | 2886 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2887 * 2888 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2889 */ 2890 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2891 __u32 serial, int vparam_len) 2892 { 2893 sctp_addiphdr_t asconf; 2894 struct sctp_chunk *retval; 2895 int length = sizeof(asconf) + vparam_len; 2896 2897 /* Create the chunk. */ 2898 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF_ACK, 0, length); 2899 if (!retval) 2900 return NULL; 2901 2902 asconf.serial = htonl(serial); 2903 2904 retval->subh.addip_hdr = 2905 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2906 2907 return retval; 2908 } 2909 2910 /* Add response parameters to an ASCONF_ACK chunk. */ 2911 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2912 __be16 err_code, sctp_addip_param_t *asconf_param) 2913 { 2914 sctp_addip_param_t ack_param; 2915 sctp_errhdr_t err_param; 2916 int asconf_param_len = 0; 2917 int err_param_len = 0; 2918 __be16 response_type; 2919 2920 if (SCTP_ERROR_NO_ERROR == err_code) { 2921 response_type = SCTP_PARAM_SUCCESS_REPORT; 2922 } else { 2923 response_type = SCTP_PARAM_ERR_CAUSE; 2924 err_param_len = sizeof(err_param); 2925 if (asconf_param) 2926 asconf_param_len = 2927 ntohs(asconf_param->param_hdr.length); 2928 } 2929 2930 /* Add Success Indication or Error Cause Indication parameter. */ 2931 ack_param.param_hdr.type = response_type; 2932 ack_param.param_hdr.length = htons(sizeof(ack_param) + 2933 err_param_len + 2934 asconf_param_len); 2935 ack_param.crr_id = crr_id; 2936 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 2937 2938 if (SCTP_ERROR_NO_ERROR == err_code) 2939 return; 2940 2941 /* Add Error Cause parameter. */ 2942 err_param.cause = err_code; 2943 err_param.length = htons(err_param_len + asconf_param_len); 2944 sctp_addto_chunk(chunk, err_param_len, &err_param); 2945 2946 /* Add the failed TLV copied from ASCONF chunk. */ 2947 if (asconf_param) 2948 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 2949 } 2950 2951 /* Process a asconf parameter. */ 2952 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 2953 struct sctp_chunk *asconf, 2954 sctp_addip_param_t *asconf_param) 2955 { 2956 struct sctp_transport *peer; 2957 struct sctp_af *af; 2958 union sctp_addr addr; 2959 union sctp_addr_param *addr_param; 2960 2961 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t); 2962 2963 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 2964 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 2965 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 2966 return SCTP_ERROR_UNKNOWN_PARAM; 2967 2968 switch (addr_param->p.type) { 2969 case SCTP_PARAM_IPV6_ADDRESS: 2970 if (!asoc->peer.ipv6_address) 2971 return SCTP_ERROR_DNS_FAILED; 2972 break; 2973 case SCTP_PARAM_IPV4_ADDRESS: 2974 if (!asoc->peer.ipv4_address) 2975 return SCTP_ERROR_DNS_FAILED; 2976 break; 2977 default: 2978 return SCTP_ERROR_DNS_FAILED; 2979 } 2980 2981 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 2982 if (unlikely(!af)) 2983 return SCTP_ERROR_DNS_FAILED; 2984 2985 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); 2986 2987 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 2988 * or multicast address. 2989 * (note: wildcard is permitted and requires special handling so 2990 * make sure we check for that) 2991 */ 2992 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 2993 return SCTP_ERROR_DNS_FAILED; 2994 2995 switch (asconf_param->param_hdr.type) { 2996 case SCTP_PARAM_ADD_IP: 2997 /* Section 4.2.1: 2998 * If the address 0.0.0.0 or ::0 is provided, the source 2999 * address of the packet MUST be added. 3000 */ 3001 if (af->is_any(&addr)) 3002 memcpy(&addr, &asconf->source, sizeof(addr)); 3003 3004 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3005 * request and does not have the local resources to add this 3006 * new address to the association, it MUST return an Error 3007 * Cause TLV set to the new error code 'Operation Refused 3008 * Due to Resource Shortage'. 3009 */ 3010 3011 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3012 if (!peer) 3013 return SCTP_ERROR_RSRC_LOW; 3014 3015 /* Start the heartbeat timer. */ 3016 if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer))) 3017 sctp_transport_hold(peer); 3018 asoc->new_transport = peer; 3019 break; 3020 case SCTP_PARAM_DEL_IP: 3021 /* ADDIP 4.3 D7) If a request is received to delete the 3022 * last remaining IP address of a peer endpoint, the receiver 3023 * MUST send an Error Cause TLV with the error cause set to the 3024 * new error code 'Request to Delete Last Remaining IP Address'. 3025 */ 3026 if (asoc->peer.transport_count == 1) 3027 return SCTP_ERROR_DEL_LAST_IP; 3028 3029 /* ADDIP 4.3 D8) If a request is received to delete an IP 3030 * address which is also the source address of the IP packet 3031 * which contained the ASCONF chunk, the receiver MUST reject 3032 * this request. To reject the request the receiver MUST send 3033 * an Error Cause TLV set to the new error code 'Request to 3034 * Delete Source IP Address' 3035 */ 3036 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3037 return SCTP_ERROR_DEL_SRC_IP; 3038 3039 /* Section 4.2.2 3040 * If the address 0.0.0.0 or ::0 is provided, all 3041 * addresses of the peer except the source address of the 3042 * packet MUST be deleted. 3043 */ 3044 if (af->is_any(&addr)) { 3045 sctp_assoc_set_primary(asoc, asconf->transport); 3046 sctp_assoc_del_nonprimary_peers(asoc, 3047 asconf->transport); 3048 } else 3049 sctp_assoc_del_peer(asoc, &addr); 3050 break; 3051 case SCTP_PARAM_SET_PRIMARY: 3052 /* ADDIP Section 4.2.4 3053 * If the address 0.0.0.0 or ::0 is provided, the receiver 3054 * MAY mark the source address of the packet as its 3055 * primary. 3056 */ 3057 if (af->is_any(&addr)) 3058 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr)); 3059 3060 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3061 if (!peer) 3062 return SCTP_ERROR_DNS_FAILED; 3063 3064 sctp_assoc_set_primary(asoc, peer); 3065 break; 3066 } 3067 3068 return SCTP_ERROR_NO_ERROR; 3069 } 3070 3071 /* Verify the ASCONF packet before we process it. */ 3072 int sctp_verify_asconf(const struct sctp_association *asoc, 3073 struct sctp_paramhdr *param_hdr, void *chunk_end, 3074 struct sctp_paramhdr **errp) { 3075 sctp_addip_param_t *asconf_param; 3076 union sctp_params param; 3077 int length, plen; 3078 3079 param.v = (sctp_paramhdr_t *) param_hdr; 3080 while (param.v <= chunk_end - sizeof(sctp_paramhdr_t)) { 3081 length = ntohs(param.p->length); 3082 *errp = param.p; 3083 3084 if (param.v > chunk_end - length || 3085 length < sizeof(sctp_paramhdr_t)) 3086 return 0; 3087 3088 switch (param.p->type) { 3089 case SCTP_PARAM_ADD_IP: 3090 case SCTP_PARAM_DEL_IP: 3091 case SCTP_PARAM_SET_PRIMARY: 3092 asconf_param = (sctp_addip_param_t *)param.v; 3093 plen = ntohs(asconf_param->param_hdr.length); 3094 if (plen < sizeof(sctp_addip_param_t) + 3095 sizeof(sctp_paramhdr_t)) 3096 return 0; 3097 break; 3098 case SCTP_PARAM_SUCCESS_REPORT: 3099 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3100 if (length != sizeof(sctp_addip_param_t)) 3101 return 0; 3102 3103 break; 3104 default: 3105 break; 3106 } 3107 3108 param.v += WORD_ROUND(length); 3109 } 3110 3111 if (param.v != chunk_end) 3112 return 0; 3113 3114 return 1; 3115 } 3116 3117 /* Process an incoming ASCONF chunk with the next expected serial no. and 3118 * return an ASCONF_ACK chunk to be sent in response. 3119 */ 3120 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3121 struct sctp_chunk *asconf) 3122 { 3123 sctp_addiphdr_t *hdr; 3124 union sctp_addr_param *addr_param; 3125 sctp_addip_param_t *asconf_param; 3126 struct sctp_chunk *asconf_ack; 3127 3128 __be16 err_code; 3129 int length = 0; 3130 int chunk_len; 3131 __u32 serial; 3132 int all_param_pass = 1; 3133 3134 chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t); 3135 hdr = (sctp_addiphdr_t *)asconf->skb->data; 3136 serial = ntohl(hdr->serial); 3137 3138 /* Skip the addiphdr and store a pointer to address parameter. */ 3139 length = sizeof(sctp_addiphdr_t); 3140 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3141 chunk_len -= length; 3142 3143 /* Skip the address parameter and store a pointer to the first 3144 * asconf parameter. 3145 */ 3146 length = ntohs(addr_param->p.length); 3147 asconf_param = (void *)addr_param + length; 3148 chunk_len -= length; 3149 3150 /* create an ASCONF_ACK chunk. 3151 * Based on the definitions of parameters, we know that the size of 3152 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3153 * parameters. 3154 */ 3155 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3156 if (!asconf_ack) 3157 goto done; 3158 3159 /* Process the TLVs contained within the ASCONF chunk. */ 3160 while (chunk_len > 0) { 3161 err_code = sctp_process_asconf_param(asoc, asconf, 3162 asconf_param); 3163 /* ADDIP 4.1 A7) 3164 * If an error response is received for a TLV parameter, 3165 * all TLVs with no response before the failed TLV are 3166 * considered successful if not reported. All TLVs after 3167 * the failed response are considered unsuccessful unless 3168 * a specific success indication is present for the parameter. 3169 */ 3170 if (SCTP_ERROR_NO_ERROR != err_code) 3171 all_param_pass = 0; 3172 3173 if (!all_param_pass) 3174 sctp_add_asconf_response(asconf_ack, 3175 asconf_param->crr_id, err_code, 3176 asconf_param); 3177 3178 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3179 * an IP address sends an 'Out of Resource' in its response, it 3180 * MUST also fail any subsequent add or delete requests bundled 3181 * in the ASCONF. 3182 */ 3183 if (SCTP_ERROR_RSRC_LOW == err_code) 3184 goto done; 3185 3186 /* Move to the next ASCONF param. */ 3187 length = ntohs(asconf_param->param_hdr.length); 3188 asconf_param = (void *)asconf_param + length; 3189 chunk_len -= length; 3190 } 3191 3192 done: 3193 asoc->peer.addip_serial++; 3194 3195 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3196 * after freeing the reference to old asconf ack if any. 3197 */ 3198 if (asconf_ack) { 3199 sctp_chunk_hold(asconf_ack); 3200 list_add_tail(&asconf_ack->transmitted_list, 3201 &asoc->asconf_ack_list); 3202 } 3203 3204 return asconf_ack; 3205 } 3206 3207 /* Process a asconf parameter that is successfully acked. */ 3208 static void sctp_asconf_param_success(struct sctp_association *asoc, 3209 sctp_addip_param_t *asconf_param) 3210 { 3211 struct sctp_af *af; 3212 union sctp_addr addr; 3213 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3214 union sctp_addr_param *addr_param; 3215 struct sctp_transport *transport; 3216 struct sctp_sockaddr_entry *saddr; 3217 3218 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t); 3219 3220 /* We have checked the packet before, so we do not check again. */ 3221 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3222 af->from_addr_param(&addr, addr_param, htons(bp->port), 0); 3223 3224 switch (asconf_param->param_hdr.type) { 3225 case SCTP_PARAM_ADD_IP: 3226 /* This is always done in BH context with a socket lock 3227 * held, so the list can not change. 3228 */ 3229 local_bh_disable(); 3230 list_for_each_entry(saddr, &bp->address_list, list) { 3231 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3232 saddr->state = SCTP_ADDR_SRC; 3233 } 3234 local_bh_enable(); 3235 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3236 transports) { 3237 dst_release(transport->dst); 3238 transport->dst = NULL; 3239 } 3240 break; 3241 case SCTP_PARAM_DEL_IP: 3242 local_bh_disable(); 3243 sctp_del_bind_addr(bp, &addr); 3244 if (asoc->asconf_addr_del_pending != NULL && 3245 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3246 kfree(asoc->asconf_addr_del_pending); 3247 asoc->asconf_addr_del_pending = NULL; 3248 } 3249 local_bh_enable(); 3250 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3251 transports) { 3252 dst_release(transport->dst); 3253 transport->dst = NULL; 3254 } 3255 break; 3256 default: 3257 break; 3258 } 3259 } 3260 3261 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3262 * for the given asconf parameter. If there is no response for this parameter, 3263 * return the error code based on the third argument 'no_err'. 3264 * ADDIP 4.1 3265 * A7) If an error response is received for a TLV parameter, all TLVs with no 3266 * response before the failed TLV are considered successful if not reported. 3267 * All TLVs after the failed response are considered unsuccessful unless a 3268 * specific success indication is present for the parameter. 3269 */ 3270 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3271 sctp_addip_param_t *asconf_param, 3272 int no_err) 3273 { 3274 sctp_addip_param_t *asconf_ack_param; 3275 sctp_errhdr_t *err_param; 3276 int length; 3277 int asconf_ack_len; 3278 __be16 err_code; 3279 3280 if (no_err) 3281 err_code = SCTP_ERROR_NO_ERROR; 3282 else 3283 err_code = SCTP_ERROR_REQ_REFUSED; 3284 3285 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3286 sizeof(sctp_chunkhdr_t); 3287 3288 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3289 * the first asconf_ack parameter. 3290 */ 3291 length = sizeof(sctp_addiphdr_t); 3292 asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data + 3293 length); 3294 asconf_ack_len -= length; 3295 3296 while (asconf_ack_len > 0) { 3297 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3298 switch(asconf_ack_param->param_hdr.type) { 3299 case SCTP_PARAM_SUCCESS_REPORT: 3300 return SCTP_ERROR_NO_ERROR; 3301 case SCTP_PARAM_ERR_CAUSE: 3302 length = sizeof(sctp_addip_param_t); 3303 err_param = (void *)asconf_ack_param + length; 3304 asconf_ack_len -= length; 3305 if (asconf_ack_len > 0) 3306 return err_param->cause; 3307 else 3308 return SCTP_ERROR_INV_PARAM; 3309 break; 3310 default: 3311 return SCTP_ERROR_INV_PARAM; 3312 } 3313 } 3314 3315 length = ntohs(asconf_ack_param->param_hdr.length); 3316 asconf_ack_param = (void *)asconf_ack_param + length; 3317 asconf_ack_len -= length; 3318 } 3319 3320 return err_code; 3321 } 3322 3323 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3324 int sctp_process_asconf_ack(struct sctp_association *asoc, 3325 struct sctp_chunk *asconf_ack) 3326 { 3327 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3328 union sctp_addr_param *addr_param; 3329 sctp_addip_param_t *asconf_param; 3330 int length = 0; 3331 int asconf_len = asconf->skb->len; 3332 int all_param_pass = 0; 3333 int no_err = 1; 3334 int retval = 0; 3335 __be16 err_code = SCTP_ERROR_NO_ERROR; 3336 3337 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3338 * a pointer to address parameter. 3339 */ 3340 length = sizeof(sctp_addip_chunk_t); 3341 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3342 asconf_len -= length; 3343 3344 /* Skip the address parameter in the last asconf sent and store a 3345 * pointer to the first asconf parameter. 3346 */ 3347 length = ntohs(addr_param->p.length); 3348 asconf_param = (void *)addr_param + length; 3349 asconf_len -= length; 3350 3351 /* ADDIP 4.1 3352 * A8) If there is no response(s) to specific TLV parameter(s), and no 3353 * failures are indicated, then all request(s) are considered 3354 * successful. 3355 */ 3356 if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t)) 3357 all_param_pass = 1; 3358 3359 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3360 while (asconf_len > 0) { 3361 if (all_param_pass) 3362 err_code = SCTP_ERROR_NO_ERROR; 3363 else { 3364 err_code = sctp_get_asconf_response(asconf_ack, 3365 asconf_param, 3366 no_err); 3367 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3368 no_err = 0; 3369 } 3370 3371 switch (err_code) { 3372 case SCTP_ERROR_NO_ERROR: 3373 sctp_asconf_param_success(asoc, asconf_param); 3374 break; 3375 3376 case SCTP_ERROR_RSRC_LOW: 3377 retval = 1; 3378 break; 3379 3380 case SCTP_ERROR_UNKNOWN_PARAM: 3381 /* Disable sending this type of asconf parameter in 3382 * future. 3383 */ 3384 asoc->peer.addip_disabled_mask |= 3385 asconf_param->param_hdr.type; 3386 break; 3387 3388 case SCTP_ERROR_REQ_REFUSED: 3389 case SCTP_ERROR_DEL_LAST_IP: 3390 case SCTP_ERROR_DEL_SRC_IP: 3391 default: 3392 break; 3393 } 3394 3395 /* Skip the processed asconf parameter and move to the next 3396 * one. 3397 */ 3398 length = ntohs(asconf_param->param_hdr.length); 3399 asconf_param = (void *)asconf_param + length; 3400 asconf_len -= length; 3401 } 3402 3403 if (no_err && asoc->src_out_of_asoc_ok) { 3404 asoc->src_out_of_asoc_ok = 0; 3405 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3406 } 3407 3408 /* Free the cached last sent asconf chunk. */ 3409 list_del_init(&asconf->transmitted_list); 3410 sctp_chunk_free(asconf); 3411 asoc->addip_last_asconf = NULL; 3412 3413 return retval; 3414 } 3415 3416 /* Make a FWD TSN chunk. */ 3417 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3418 __u32 new_cum_tsn, size_t nstreams, 3419 struct sctp_fwdtsn_skip *skiplist) 3420 { 3421 struct sctp_chunk *retval = NULL; 3422 struct sctp_fwdtsn_hdr ftsn_hdr; 3423 struct sctp_fwdtsn_skip skip; 3424 size_t hint; 3425 int i; 3426 3427 hint = (nstreams + 1) * sizeof(__u32); 3428 3429 retval = sctp_make_chunk(asoc, SCTP_CID_FWD_TSN, 0, hint); 3430 3431 if (!retval) 3432 return NULL; 3433 3434 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3435 retval->subh.fwdtsn_hdr = 3436 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3437 3438 for (i = 0; i < nstreams; i++) { 3439 skip.stream = skiplist[i].stream; 3440 skip.ssn = skiplist[i].ssn; 3441 sctp_addto_chunk(retval, sizeof(skip), &skip); 3442 } 3443 3444 return retval; 3445 } 3446