1 /* SCTP kernel implementation 2 * (C) Copyright IBM Corp. 2001, 2004 3 * Copyright (c) 1999-2000 Cisco, Inc. 4 * Copyright (c) 1999-2001 Motorola, Inc. 5 * Copyright (c) 2001-2002 Intel Corp. 6 * 7 * This file is part of the SCTP kernel implementation 8 * 9 * These functions work with the state functions in sctp_sm_statefuns.c 10 * to implement the state operations. These functions implement the 11 * steps which require modifying existing data structures. 12 * 13 * This SCTP implementation is free software; 14 * you can redistribute it and/or modify it under the terms of 15 * the GNU General Public License as published by 16 * the Free Software Foundation; either version 2, or (at your option) 17 * any later version. 18 * 19 * This SCTP implementation is distributed in the hope that it 20 * will be useful, but WITHOUT ANY WARRANTY; without even the implied 21 * ************************ 22 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 23 * See the GNU General Public License for more details. 24 * 25 * You should have received a copy of the GNU General Public License 26 * along with GNU CC; see the file COPYING. If not, write to 27 * the Free Software Foundation, 59 Temple Place - Suite 330, 28 * Boston, MA 02111-1307, USA. 29 * 30 * Please send any bug reports or fixes you make to the 31 * email address(es): 32 * lksctp developers <lksctp-developers@lists.sourceforge.net> 33 * 34 * Or submit a bug report through the following website: 35 * http://www.sf.net/projects/lksctp 36 * 37 * Written or modified by: 38 * La Monte H.P. Yarroll <piggy@acm.org> 39 * Karl Knutson <karl@athena.chicago.il.us> 40 * C. Robin <chris@hundredacre.ac.uk> 41 * Jon Grimm <jgrimm@us.ibm.com> 42 * Xingang Guo <xingang.guo@intel.com> 43 * Dajiang Zhang <dajiang.zhang@nokia.com> 44 * Sridhar Samudrala <sri@us.ibm.com> 45 * Daisy Chang <daisyc@us.ibm.com> 46 * Ardelle Fan <ardelle.fan@intel.com> 47 * Kevin Gao <kevin.gao@intel.com> 48 * 49 * Any bugs reported given to us we will try to fix... any fixes shared will 50 * be incorporated into the next SCTP release. 51 */ 52 53 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 54 55 #include <linux/types.h> 56 #include <linux/kernel.h> 57 #include <linux/ip.h> 58 #include <linux/ipv6.h> 59 #include <linux/net.h> 60 #include <linux/inet.h> 61 #include <linux/scatterlist.h> 62 #include <linux/crypto.h> 63 #include <linux/slab.h> 64 #include <net/sock.h> 65 66 #include <linux/skbuff.h> 67 #include <linux/random.h> /* for get_random_bytes */ 68 #include <net/sctp/sctp.h> 69 #include <net/sctp/sm.h> 70 71 SCTP_STATIC 72 struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc, 73 __u8 type, __u8 flags, int paylen); 74 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, 75 const struct sctp_association *asoc, 76 const struct sctp_chunk *init_chunk, 77 int *cookie_len, 78 const __u8 *raw_addrs, int addrs_len); 79 static int sctp_process_param(struct sctp_association *asoc, 80 union sctp_params param, 81 const union sctp_addr *peer_addr, 82 gfp_t gfp); 83 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 84 const void *data); 85 86 /* What was the inbound interface for this chunk? */ 87 int sctp_chunk_iif(const struct sctp_chunk *chunk) 88 { 89 struct sctp_af *af; 90 int iif = 0; 91 92 af = sctp_get_af_specific(ipver2af(ip_hdr(chunk->skb)->version)); 93 if (af) 94 iif = af->skb_iif(chunk->skb); 95 96 return iif; 97 } 98 99 /* RFC 2960 3.3.2 Initiation (INIT) (1) 100 * 101 * Note 2: The ECN capable field is reserved for future use of 102 * Explicit Congestion Notification. 103 */ 104 static const struct sctp_paramhdr ecap_param = { 105 SCTP_PARAM_ECN_CAPABLE, 106 cpu_to_be16(sizeof(struct sctp_paramhdr)), 107 }; 108 static const struct sctp_paramhdr prsctp_param = { 109 SCTP_PARAM_FWD_TSN_SUPPORT, 110 cpu_to_be16(sizeof(struct sctp_paramhdr)), 111 }; 112 113 /* A helper to initialize an op error inside a 114 * provided chunk, as most cause codes will be embedded inside an 115 * abort chunk. 116 */ 117 void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, 118 size_t paylen) 119 { 120 sctp_errhdr_t err; 121 __u16 len; 122 123 /* Cause code constants are now defined in network order. */ 124 err.cause = cause_code; 125 len = sizeof(sctp_errhdr_t) + paylen; 126 err.length = htons(len); 127 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err); 128 } 129 130 /* A helper to initialize an op error inside a 131 * provided chunk, as most cause codes will be embedded inside an 132 * abort chunk. Differs from sctp_init_cause in that it won't oops 133 * if there isn't enough space in the op error chunk 134 */ 135 static int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code, 136 size_t paylen) 137 { 138 sctp_errhdr_t err; 139 __u16 len; 140 141 /* Cause code constants are now defined in network order. */ 142 err.cause = cause_code; 143 len = sizeof(sctp_errhdr_t) + paylen; 144 err.length = htons(len); 145 146 if (skb_tailroom(chunk->skb) < len) 147 return -ENOSPC; 148 chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk, 149 sizeof(sctp_errhdr_t), 150 &err); 151 return 0; 152 } 153 /* 3.3.2 Initiation (INIT) (1) 154 * 155 * This chunk is used to initiate a SCTP association between two 156 * endpoints. The format of the INIT chunk is shown below: 157 * 158 * 0 1 2 3 159 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 160 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 161 * | Type = 1 | Chunk Flags | Chunk Length | 162 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 163 * | Initiate Tag | 164 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 165 * | Advertised Receiver Window Credit (a_rwnd) | 166 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 167 * | Number of Outbound Streams | Number of Inbound Streams | 168 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 169 * | Initial TSN | 170 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 171 * \ \ 172 * / Optional/Variable-Length Parameters / 173 * \ \ 174 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 175 * 176 * 177 * The INIT chunk contains the following parameters. Unless otherwise 178 * noted, each parameter MUST only be included once in the INIT chunk. 179 * 180 * Fixed Parameters Status 181 * ---------------------------------------------- 182 * Initiate Tag Mandatory 183 * Advertised Receiver Window Credit Mandatory 184 * Number of Outbound Streams Mandatory 185 * Number of Inbound Streams Mandatory 186 * Initial TSN Mandatory 187 * 188 * Variable Parameters Status Type Value 189 * ------------------------------------------------------------- 190 * IPv4 Address (Note 1) Optional 5 191 * IPv6 Address (Note 1) Optional 6 192 * Cookie Preservative Optional 9 193 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000) 194 * Host Name Address (Note 3) Optional 11 195 * Supported Address Types (Note 4) Optional 12 196 */ 197 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc, 198 const struct sctp_bind_addr *bp, 199 gfp_t gfp, int vparam_len) 200 { 201 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_association *aptr = (struct sctp_association *)asoc; 738 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; 739 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; 740 struct sctp_transport *trans; 741 742 memset(gabs, 0, sizeof(gabs)); 743 ctsn = sctp_tsnmap_get_ctsn(map); 744 SCTP_DEBUG_PRINTK("sackCTSNAck sent: 0x%x.\n", ctsn); 745 746 /* How much room is needed in the chunk? */ 747 num_gabs = sctp_tsnmap_num_gabs(map, gabs); 748 num_dup_tsns = sctp_tsnmap_num_dups(map); 749 750 /* Initialize the SACK header. */ 751 sack.cum_tsn_ack = htonl(ctsn); 752 sack.a_rwnd = htonl(asoc->a_rwnd); 753 sack.num_gap_ack_blocks = htons(num_gabs); 754 sack.num_dup_tsns = htons(num_dup_tsns); 755 756 len = sizeof(sack) 757 + sizeof(struct sctp_gap_ack_block) * num_gabs 758 + sizeof(__u32) * num_dup_tsns; 759 760 /* Create the chunk. */ 761 retval = sctp_make_chunk(asoc, SCTP_CID_SACK, 0, len); 762 if (!retval) 763 goto nodata; 764 765 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 766 * 767 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 768 * HEARTBEAT ACK, etc.) to the same destination transport 769 * address from which it received the DATA or control chunk to 770 * which it is replying. This rule should also be followed if 771 * the endpoint is bundling DATA chunks together with the 772 * reply chunk. 773 * 774 * However, when acknowledging multiple DATA chunks received 775 * in packets from different source addresses in a single 776 * SACK, the SACK chunk may be transmitted to one of the 777 * destination transport addresses from which the DATA or 778 * control chunks being acknowledged were received. 779 * 780 * [BUG: We do not implement the following paragraph. 781 * Perhaps we should remember the last transport we used for a 782 * SACK and avoid that (if possible) if we have seen any 783 * duplicates. --piggy] 784 * 785 * When a receiver of a duplicate DATA chunk sends a SACK to a 786 * multi- homed endpoint it MAY be beneficial to vary the 787 * destination address and not use the source address of the 788 * DATA chunk. The reason being that receiving a duplicate 789 * from a multi-homed endpoint might indicate that the return 790 * path (as specified in the source address of the DATA chunk) 791 * for the SACK is broken. 792 * 793 * [Send to the address from which we last received a DATA chunk.] 794 */ 795 retval->transport = asoc->peer.last_data_from; 796 797 retval->subh.sack_hdr = 798 sctp_addto_chunk(retval, sizeof(sack), &sack); 799 800 /* Add the gap ack block information. */ 801 if (num_gabs) 802 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, 803 gabs); 804 805 /* Add the duplicate TSN information. */ 806 if (num_dup_tsns) 807 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, 808 sctp_tsnmap_get_dups(map)); 809 810 /* Once we have a sack generated, check to see what our sack 811 * generation is, if its 0, reset the transports to 0, and reset 812 * the association generation to 1 813 * 814 * The idea is that zero is never used as a valid generation for the 815 * association so no transport will match after a wrap event like this, 816 * Until the next sack 817 */ 818 if (++aptr->peer.sack_generation == 0) { 819 list_for_each_entry(trans, &asoc->peer.transport_addr_list, 820 transports) 821 trans->sack_generation = 0; 822 aptr->peer.sack_generation = 1; 823 } 824 nodata: 825 return retval; 826 } 827 828 /* Make a SHUTDOWN chunk. */ 829 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 830 const struct sctp_chunk *chunk) 831 { 832 struct sctp_chunk *retval; 833 sctp_shutdownhdr_t shut; 834 __u32 ctsn; 835 836 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 837 shut.cum_tsn_ack = htonl(ctsn); 838 839 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN, 0, 840 sizeof(sctp_shutdownhdr_t)); 841 if (!retval) 842 goto nodata; 843 844 retval->subh.shutdown_hdr = 845 sctp_addto_chunk(retval, sizeof(shut), &shut); 846 847 if (chunk) 848 retval->transport = chunk->transport; 849 nodata: 850 return retval; 851 } 852 853 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 854 const struct sctp_chunk *chunk) 855 { 856 struct sctp_chunk *retval; 857 858 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0); 859 860 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 861 * 862 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 863 * HEARTBEAT ACK, * etc.) to the same destination transport 864 * address from which it * received the DATA or control chunk 865 * to which it is replying. 866 * 867 * [ACK back to where the SHUTDOWN came from.] 868 */ 869 if (retval && chunk) 870 retval->transport = chunk->transport; 871 872 return retval; 873 } 874 875 struct sctp_chunk *sctp_make_shutdown_complete( 876 const struct sctp_association *asoc, 877 const struct sctp_chunk *chunk) 878 { 879 struct sctp_chunk *retval; 880 __u8 flags = 0; 881 882 /* Set the T-bit if we have no association (vtag will be 883 * reflected) 884 */ 885 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; 886 887 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0); 888 889 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 890 * 891 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 892 * HEARTBEAT ACK, * etc.) to the same destination transport 893 * address from which it * received the DATA or control chunk 894 * to which it is replying. 895 * 896 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK 897 * came from.] 898 */ 899 if (retval && chunk) 900 retval->transport = chunk->transport; 901 902 return retval; 903 } 904 905 /* Create an ABORT. Note that we set the T bit if we have no 906 * association, except when responding to an INIT (sctpimpguide 2.41). 907 */ 908 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 909 const struct sctp_chunk *chunk, 910 const size_t hint) 911 { 912 struct sctp_chunk *retval; 913 __u8 flags = 0; 914 915 /* Set the T-bit if we have no association and 'chunk' is not 916 * an INIT (vtag will be reflected). 917 */ 918 if (!asoc) { 919 if (chunk && chunk->chunk_hdr && 920 chunk->chunk_hdr->type == SCTP_CID_INIT) 921 flags = 0; 922 else 923 flags = SCTP_CHUNK_FLAG_T; 924 } 925 926 retval = sctp_make_chunk(asoc, SCTP_CID_ABORT, flags, hint); 927 928 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 929 * 930 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 931 * HEARTBEAT ACK, * etc.) to the same destination transport 932 * address from which it * received the DATA or control chunk 933 * to which it is replying. 934 * 935 * [ABORT back to where the offender came from.] 936 */ 937 if (retval && chunk) 938 retval->transport = chunk->transport; 939 940 return retval; 941 } 942 943 /* Helper to create ABORT with a NO_USER_DATA error. */ 944 struct sctp_chunk *sctp_make_abort_no_data( 945 const struct sctp_association *asoc, 946 const struct sctp_chunk *chunk, __u32 tsn) 947 { 948 struct sctp_chunk *retval; 949 __be32 payload; 950 951 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) 952 + sizeof(tsn)); 953 954 if (!retval) 955 goto no_mem; 956 957 /* Put the tsn back into network byte order. */ 958 payload = htonl(tsn); 959 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload)); 960 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload); 961 962 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 963 * 964 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 965 * HEARTBEAT ACK, * etc.) to the same destination transport 966 * address from which it * received the DATA or control chunk 967 * to which it is replying. 968 * 969 * [ABORT back to where the offender came from.] 970 */ 971 if (chunk) 972 retval->transport = chunk->transport; 973 974 no_mem: 975 return retval; 976 } 977 978 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ 979 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 980 const struct msghdr *msg, 981 size_t paylen) 982 { 983 struct sctp_chunk *retval; 984 void *payload = NULL; 985 int err; 986 987 retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen); 988 if (!retval) 989 goto err_chunk; 990 991 if (paylen) { 992 /* Put the msg_iov together into payload. */ 993 payload = kmalloc(paylen, GFP_KERNEL); 994 if (!payload) 995 goto err_payload; 996 997 err = memcpy_fromiovec(payload, msg->msg_iov, paylen); 998 if (err < 0) 999 goto err_copy; 1000 } 1001 1002 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); 1003 sctp_addto_chunk(retval, paylen, payload); 1004 1005 if (paylen) 1006 kfree(payload); 1007 1008 return retval; 1009 1010 err_copy: 1011 kfree(payload); 1012 err_payload: 1013 sctp_chunk_free(retval); 1014 retval = NULL; 1015 err_chunk: 1016 return retval; 1017 } 1018 1019 /* Append bytes to the end of a parameter. Will panic if chunk is not big 1020 * enough. 1021 */ 1022 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 1023 const void *data) 1024 { 1025 void *target; 1026 int chunklen = ntohs(chunk->chunk_hdr->length); 1027 1028 target = skb_put(chunk->skb, len); 1029 1030 if (data) 1031 memcpy(target, data, len); 1032 else 1033 memset(target, 0, len); 1034 1035 /* Adjust the chunk length field. */ 1036 chunk->chunk_hdr->length = htons(chunklen + len); 1037 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1038 1039 return target; 1040 } 1041 1042 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ 1043 struct sctp_chunk *sctp_make_abort_violation( 1044 const struct sctp_association *asoc, 1045 const struct sctp_chunk *chunk, 1046 const __u8 *payload, 1047 const size_t paylen) 1048 { 1049 struct sctp_chunk *retval; 1050 struct sctp_paramhdr phdr; 1051 1052 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen 1053 + sizeof(sctp_paramhdr_t)); 1054 if (!retval) 1055 goto end; 1056 1057 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen 1058 + sizeof(sctp_paramhdr_t)); 1059 1060 phdr.type = htons(chunk->chunk_hdr->type); 1061 phdr.length = chunk->chunk_hdr->length; 1062 sctp_addto_chunk(retval, paylen, payload); 1063 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr); 1064 1065 end: 1066 return retval; 1067 } 1068 1069 struct sctp_chunk *sctp_make_violation_paramlen( 1070 const struct sctp_association *asoc, 1071 const struct sctp_chunk *chunk, 1072 struct sctp_paramhdr *param) 1073 { 1074 struct sctp_chunk *retval; 1075 static const char error[] = "The following parameter had invalid length:"; 1076 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t) + 1077 sizeof(sctp_paramhdr_t); 1078 1079 retval = sctp_make_abort(asoc, chunk, payload_len); 1080 if (!retval) 1081 goto nodata; 1082 1083 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, 1084 sizeof(error) + sizeof(sctp_paramhdr_t)); 1085 sctp_addto_chunk(retval, sizeof(error), error); 1086 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), param); 1087 1088 nodata: 1089 return retval; 1090 } 1091 1092 /* Make a HEARTBEAT chunk. */ 1093 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1094 const struct sctp_transport *transport) 1095 { 1096 struct sctp_chunk *retval; 1097 sctp_sender_hb_info_t hbinfo; 1098 1099 retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT, 0, sizeof(hbinfo)); 1100 1101 if (!retval) 1102 goto nodata; 1103 1104 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; 1105 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t)); 1106 hbinfo.daddr = transport->ipaddr; 1107 hbinfo.sent_at = jiffies; 1108 hbinfo.hb_nonce = transport->hb_nonce; 1109 1110 /* Cast away the 'const', as this is just telling the chunk 1111 * what transport it belongs to. 1112 */ 1113 retval->transport = (struct sctp_transport *) transport; 1114 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo), 1115 &hbinfo); 1116 1117 nodata: 1118 return retval; 1119 } 1120 1121 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1122 const struct sctp_chunk *chunk, 1123 const void *payload, const size_t paylen) 1124 { 1125 struct sctp_chunk *retval; 1126 1127 retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen); 1128 if (!retval) 1129 goto nodata; 1130 1131 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1132 1133 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1134 * 1135 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1136 * HEARTBEAT ACK, * etc.) to the same destination transport 1137 * address from which it * received the DATA or control chunk 1138 * to which it is replying. 1139 * 1140 * [HBACK back to where the HEARTBEAT came from.] 1141 */ 1142 if (chunk) 1143 retval->transport = chunk->transport; 1144 1145 nodata: 1146 return retval; 1147 } 1148 1149 /* Create an Operation Error chunk with the specified space reserved. 1150 * This routine can be used for containing multiple causes in the chunk. 1151 */ 1152 static struct sctp_chunk *sctp_make_op_error_space( 1153 const struct sctp_association *asoc, 1154 const struct sctp_chunk *chunk, 1155 size_t size) 1156 { 1157 struct sctp_chunk *retval; 1158 1159 retval = sctp_make_chunk(asoc, SCTP_CID_ERROR, 0, 1160 sizeof(sctp_errhdr_t) + size); 1161 if (!retval) 1162 goto nodata; 1163 1164 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1165 * 1166 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1167 * HEARTBEAT ACK, etc.) to the same destination transport 1168 * address from which it received the DATA or control chunk 1169 * to which it is replying. 1170 * 1171 */ 1172 if (chunk) 1173 retval->transport = chunk->transport; 1174 1175 nodata: 1176 return retval; 1177 } 1178 1179 /* Create an Operation Error chunk of a fixed size, 1180 * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) 1181 * This is a helper function to allocate an error chunk for 1182 * for those invalid parameter codes in which we may not want 1183 * to report all the errors, if the incomming chunk is large 1184 */ 1185 static inline struct sctp_chunk *sctp_make_op_error_fixed( 1186 const struct sctp_association *asoc, 1187 const struct sctp_chunk *chunk) 1188 { 1189 size_t size = asoc ? asoc->pathmtu : 0; 1190 1191 if (!size) 1192 size = SCTP_DEFAULT_MAXSEGMENT; 1193 1194 return sctp_make_op_error_space(asoc, chunk, size); 1195 } 1196 1197 /* Create an Operation Error chunk. */ 1198 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1199 const struct sctp_chunk *chunk, 1200 __be16 cause_code, const void *payload, 1201 size_t paylen, size_t reserve_tail) 1202 { 1203 struct sctp_chunk *retval; 1204 1205 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); 1206 if (!retval) 1207 goto nodata; 1208 1209 sctp_init_cause(retval, cause_code, paylen + reserve_tail); 1210 sctp_addto_chunk(retval, paylen, payload); 1211 if (reserve_tail) 1212 sctp_addto_param(retval, reserve_tail, NULL); 1213 1214 nodata: 1215 return retval; 1216 } 1217 1218 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc) 1219 { 1220 struct sctp_chunk *retval; 1221 struct sctp_hmac *hmac_desc; 1222 struct sctp_authhdr auth_hdr; 1223 __u8 *hmac; 1224 1225 /* Get the first hmac that the peer told us to use */ 1226 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1227 if (unlikely(!hmac_desc)) 1228 return NULL; 1229 1230 retval = sctp_make_chunk(asoc, SCTP_CID_AUTH, 0, 1231 hmac_desc->hmac_len + sizeof(sctp_authhdr_t)); 1232 if (!retval) 1233 return NULL; 1234 1235 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1236 auth_hdr.shkey_id = htons(asoc->active_key_id); 1237 1238 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t), 1239 &auth_hdr); 1240 1241 hmac = skb_put(retval->skb, hmac_desc->hmac_len); 1242 memset(hmac, 0, hmac_desc->hmac_len); 1243 1244 /* Adjust the chunk header to include the empty MAC */ 1245 retval->chunk_hdr->length = 1246 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1247 retval->chunk_end = skb_tail_pointer(retval->skb); 1248 1249 return retval; 1250 } 1251 1252 1253 /******************************************************************** 1254 * 2nd Level Abstractions 1255 ********************************************************************/ 1256 1257 /* Turn an skb into a chunk. 1258 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1259 */ 1260 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1261 const struct sctp_association *asoc, 1262 struct sock *sk) 1263 { 1264 struct sctp_chunk *retval; 1265 1266 retval = kmem_cache_zalloc(sctp_chunk_cachep, GFP_ATOMIC); 1267 1268 if (!retval) 1269 goto nodata; 1270 1271 if (!sk) { 1272 SCTP_DEBUG_PRINTK("chunkifying skb %p w/o an sk\n", skb); 1273 } 1274 1275 INIT_LIST_HEAD(&retval->list); 1276 retval->skb = skb; 1277 retval->asoc = (struct sctp_association *)asoc; 1278 retval->has_tsn = 0; 1279 retval->has_ssn = 0; 1280 retval->rtt_in_progress = 0; 1281 retval->sent_at = 0; 1282 retval->singleton = 1; 1283 retval->end_of_packet = 0; 1284 retval->ecn_ce_done = 0; 1285 retval->pdiscard = 0; 1286 1287 /* sctpimpguide-05.txt Section 2.8.2 1288 * M1) Each time a new DATA chunk is transmitted 1289 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1290 * 'TSN.Missing.Report' count will be used to determine missing chunks 1291 * and when to fast retransmit. 1292 */ 1293 retval->tsn_missing_report = 0; 1294 retval->tsn_gap_acked = 0; 1295 retval->fast_retransmit = SCTP_CAN_FRTX; 1296 1297 /* If this is a fragmented message, track all fragments 1298 * of the message (for SEND_FAILED). 1299 */ 1300 retval->msg = NULL; 1301 1302 /* Polish the bead hole. */ 1303 INIT_LIST_HEAD(&retval->transmitted_list); 1304 INIT_LIST_HEAD(&retval->frag_list); 1305 SCTP_DBG_OBJCNT_INC(chunk); 1306 atomic_set(&retval->refcnt, 1); 1307 1308 nodata: 1309 return retval; 1310 } 1311 1312 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1313 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1314 union sctp_addr *dest) 1315 { 1316 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1317 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1318 } 1319 1320 /* Extract the source address from a chunk. */ 1321 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1322 { 1323 /* If we have a known transport, use that. */ 1324 if (chunk->transport) { 1325 return &chunk->transport->ipaddr; 1326 } else { 1327 /* Otherwise, extract it from the IP header. */ 1328 return &chunk->source; 1329 } 1330 } 1331 1332 /* Create a new chunk, setting the type and flags headers from the 1333 * arguments, reserving enough space for a 'paylen' byte payload. 1334 */ 1335 SCTP_STATIC 1336 struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc, 1337 __u8 type, __u8 flags, int paylen) 1338 { 1339 struct sctp_chunk *retval; 1340 sctp_chunkhdr_t *chunk_hdr; 1341 struct sk_buff *skb; 1342 struct sock *sk; 1343 1344 /* No need to allocate LL here, as this is only a chunk. */ 1345 skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen), 1346 GFP_ATOMIC); 1347 if (!skb) 1348 goto nodata; 1349 1350 /* Make room for the chunk header. */ 1351 chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t)); 1352 chunk_hdr->type = type; 1353 chunk_hdr->flags = flags; 1354 chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t)); 1355 1356 sk = asoc ? asoc->base.sk : NULL; 1357 retval = sctp_chunkify(skb, asoc, sk); 1358 if (!retval) { 1359 kfree_skb(skb); 1360 goto nodata; 1361 } 1362 1363 retval->chunk_hdr = chunk_hdr; 1364 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr); 1365 1366 /* Determine if the chunk needs to be authenticated */ 1367 if (sctp_auth_send_cid(type, asoc)) 1368 retval->auth = 1; 1369 1370 /* Set the skb to the belonging sock for accounting. */ 1371 skb->sk = sk; 1372 1373 return retval; 1374 nodata: 1375 return NULL; 1376 } 1377 1378 1379 /* Release the memory occupied by a chunk. */ 1380 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1381 { 1382 BUG_ON(!list_empty(&chunk->list)); 1383 list_del_init(&chunk->transmitted_list); 1384 1385 /* Free the chunk skb data and the SCTP_chunk stub itself. */ 1386 dev_kfree_skb(chunk->skb); 1387 1388 SCTP_DBG_OBJCNT_DEC(chunk); 1389 kmem_cache_free(sctp_chunk_cachep, chunk); 1390 } 1391 1392 /* Possibly, free the chunk. */ 1393 void sctp_chunk_free(struct sctp_chunk *chunk) 1394 { 1395 /* Release our reference on the message tracker. */ 1396 if (chunk->msg) 1397 sctp_datamsg_put(chunk->msg); 1398 1399 sctp_chunk_put(chunk); 1400 } 1401 1402 /* Grab a reference to the chunk. */ 1403 void sctp_chunk_hold(struct sctp_chunk *ch) 1404 { 1405 atomic_inc(&ch->refcnt); 1406 } 1407 1408 /* Release a reference to the chunk. */ 1409 void sctp_chunk_put(struct sctp_chunk *ch) 1410 { 1411 if (atomic_dec_and_test(&ch->refcnt)) 1412 sctp_chunk_destroy(ch); 1413 } 1414 1415 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1416 * enough. 1417 */ 1418 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1419 { 1420 void *target; 1421 void *padding; 1422 int chunklen = ntohs(chunk->chunk_hdr->length); 1423 int padlen = WORD_ROUND(chunklen) - chunklen; 1424 1425 padding = skb_put(chunk->skb, padlen); 1426 target = skb_put(chunk->skb, len); 1427 1428 memset(padding, 0, padlen); 1429 memcpy(target, data, len); 1430 1431 /* Adjust the chunk length field. */ 1432 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1433 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1434 1435 return target; 1436 } 1437 1438 /* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient 1439 * space in the chunk 1440 */ 1441 void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk, 1442 int len, const void *data) 1443 { 1444 if (skb_tailroom(chunk->skb) >= len) 1445 return sctp_addto_chunk(chunk, len, data); 1446 else 1447 return NULL; 1448 } 1449 1450 /* Append bytes from user space to the end of a chunk. Will panic if 1451 * chunk is not big enough. 1452 * Returns a kernel err value. 1453 */ 1454 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len, 1455 struct iovec *data) 1456 { 1457 __u8 *target; 1458 int err = 0; 1459 1460 /* Make room in chunk for data. */ 1461 target = skb_put(chunk->skb, len); 1462 1463 /* Copy data (whole iovec) into chunk */ 1464 if ((err = memcpy_fromiovecend(target, data, off, len))) 1465 goto out; 1466 1467 /* Adjust the chunk length field. */ 1468 chunk->chunk_hdr->length = 1469 htons(ntohs(chunk->chunk_hdr->length) + len); 1470 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1471 1472 out: 1473 return err; 1474 } 1475 1476 /* Helper function to assign a TSN if needed. This assumes that both 1477 * the data_hdr and association have already been assigned. 1478 */ 1479 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1480 { 1481 struct sctp_datamsg *msg; 1482 struct sctp_chunk *lchunk; 1483 struct sctp_stream *stream; 1484 __u16 ssn; 1485 __u16 sid; 1486 1487 if (chunk->has_ssn) 1488 return; 1489 1490 /* All fragments will be on the same stream */ 1491 sid = ntohs(chunk->subh.data_hdr->stream); 1492 stream = &chunk->asoc->ssnmap->out; 1493 1494 /* Now assign the sequence number to the entire message. 1495 * All fragments must have the same stream sequence number. 1496 */ 1497 msg = chunk->msg; 1498 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1499 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1500 ssn = 0; 1501 } else { 1502 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1503 ssn = sctp_ssn_next(stream, sid); 1504 else 1505 ssn = sctp_ssn_peek(stream, sid); 1506 } 1507 1508 lchunk->subh.data_hdr->ssn = htons(ssn); 1509 lchunk->has_ssn = 1; 1510 } 1511 } 1512 1513 /* Helper function to assign a TSN if needed. This assumes that both 1514 * the data_hdr and association have already been assigned. 1515 */ 1516 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1517 { 1518 if (!chunk->has_tsn) { 1519 /* This is the last possible instant to 1520 * assign a TSN. 1521 */ 1522 chunk->subh.data_hdr->tsn = 1523 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1524 chunk->has_tsn = 1; 1525 } 1526 } 1527 1528 /* Create a CLOSED association to use with an incoming packet. */ 1529 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1530 struct sctp_chunk *chunk, 1531 gfp_t gfp) 1532 { 1533 struct sctp_association *asoc; 1534 struct sk_buff *skb; 1535 sctp_scope_t scope; 1536 struct sctp_af *af; 1537 1538 /* Create the bare association. */ 1539 scope = sctp_scope(sctp_source(chunk)); 1540 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1541 if (!asoc) 1542 goto nodata; 1543 asoc->temp = 1; 1544 skb = chunk->skb; 1545 /* Create an entry for the source address of the packet. */ 1546 af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version)); 1547 if (unlikely(!af)) 1548 goto fail; 1549 af->from_skb(&asoc->c.peer_addr, skb, 1); 1550 nodata: 1551 return asoc; 1552 1553 fail: 1554 sctp_association_free(asoc); 1555 return NULL; 1556 } 1557 1558 /* Build a cookie representing asoc. 1559 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1560 */ 1561 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, 1562 const struct sctp_association *asoc, 1563 const struct sctp_chunk *init_chunk, 1564 int *cookie_len, 1565 const __u8 *raw_addrs, int addrs_len) 1566 { 1567 sctp_cookie_param_t *retval; 1568 struct sctp_signed_cookie *cookie; 1569 struct scatterlist sg; 1570 int headersize, bodysize; 1571 unsigned int keylen; 1572 char *key; 1573 1574 /* Header size is static data prior to the actual cookie, including 1575 * any padding. 1576 */ 1577 headersize = sizeof(sctp_paramhdr_t) + 1578 (sizeof(struct sctp_signed_cookie) - 1579 sizeof(struct sctp_cookie)); 1580 bodysize = sizeof(struct sctp_cookie) 1581 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1582 1583 /* Pad out the cookie to a multiple to make the signature 1584 * functions simpler to write. 1585 */ 1586 if (bodysize % SCTP_COOKIE_MULTIPLE) 1587 bodysize += SCTP_COOKIE_MULTIPLE 1588 - (bodysize % SCTP_COOKIE_MULTIPLE); 1589 *cookie_len = headersize + bodysize; 1590 1591 /* Clear this memory since we are sending this data structure 1592 * out on the network. 1593 */ 1594 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1595 if (!retval) 1596 goto nodata; 1597 1598 cookie = (struct sctp_signed_cookie *) retval->body; 1599 1600 /* Set up the parameter header. */ 1601 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1602 retval->p.length = htons(*cookie_len); 1603 1604 /* Copy the cookie part of the association itself. */ 1605 cookie->c = asoc->c; 1606 /* Save the raw address list length in the cookie. */ 1607 cookie->c.raw_addr_list_len = addrs_len; 1608 1609 /* Remember PR-SCTP capability. */ 1610 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1611 1612 /* Save adaptation indication in the cookie. */ 1613 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1614 1615 /* Set an expiration time for the cookie. */ 1616 do_gettimeofday(&cookie->c.expiration); 1617 TIMEVAL_ADD(asoc->cookie_life, cookie->c.expiration); 1618 1619 /* Copy the peer's init packet. */ 1620 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr, 1621 ntohs(init_chunk->chunk_hdr->length)); 1622 1623 /* Copy the raw local address list of the association. */ 1624 memcpy((__u8 *)&cookie->c.peer_init[0] + 1625 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1626 1627 if (sctp_sk(ep->base.sk)->hmac) { 1628 struct hash_desc desc; 1629 1630 /* Sign the message. */ 1631 sg_init_one(&sg, &cookie->c, bodysize); 1632 keylen = SCTP_SECRET_SIZE; 1633 key = (char *)ep->secret_key[ep->current_key]; 1634 desc.tfm = sctp_sk(ep->base.sk)->hmac; 1635 desc.flags = 0; 1636 1637 if (crypto_hash_setkey(desc.tfm, key, keylen) || 1638 crypto_hash_digest(&desc, &sg, bodysize, cookie->signature)) 1639 goto free_cookie; 1640 } 1641 1642 return retval; 1643 1644 free_cookie: 1645 kfree(retval); 1646 nodata: 1647 *cookie_len = 0; 1648 return NULL; 1649 } 1650 1651 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1652 struct sctp_association *sctp_unpack_cookie( 1653 const struct sctp_endpoint *ep, 1654 const struct sctp_association *asoc, 1655 struct sctp_chunk *chunk, gfp_t gfp, 1656 int *error, struct sctp_chunk **errp) 1657 { 1658 struct sctp_association *retval = NULL; 1659 struct sctp_signed_cookie *cookie; 1660 struct sctp_cookie *bear_cookie; 1661 int headersize, bodysize, fixed_size; 1662 __u8 *digest = ep->digest; 1663 struct scatterlist sg; 1664 unsigned int keylen, len; 1665 char *key; 1666 sctp_scope_t scope; 1667 struct sk_buff *skb = chunk->skb; 1668 struct timeval tv; 1669 struct hash_desc desc; 1670 1671 /* Header size is static data prior to the actual cookie, including 1672 * any padding. 1673 */ 1674 headersize = sizeof(sctp_chunkhdr_t) + 1675 (sizeof(struct sctp_signed_cookie) - 1676 sizeof(struct sctp_cookie)); 1677 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1678 fixed_size = headersize + sizeof(struct sctp_cookie); 1679 1680 /* Verify that the chunk looks like it even has a cookie. 1681 * There must be enough room for our cookie and our peer's 1682 * INIT chunk. 1683 */ 1684 len = ntohs(chunk->chunk_hdr->length); 1685 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1686 goto malformed; 1687 1688 /* Verify that the cookie has been padded out. */ 1689 if (bodysize % SCTP_COOKIE_MULTIPLE) 1690 goto malformed; 1691 1692 /* Process the cookie. */ 1693 cookie = chunk->subh.cookie_hdr; 1694 bear_cookie = &cookie->c; 1695 1696 if (!sctp_sk(ep->base.sk)->hmac) 1697 goto no_hmac; 1698 1699 /* Check the signature. */ 1700 keylen = SCTP_SECRET_SIZE; 1701 sg_init_one(&sg, bear_cookie, bodysize); 1702 key = (char *)ep->secret_key[ep->current_key]; 1703 desc.tfm = sctp_sk(ep->base.sk)->hmac; 1704 desc.flags = 0; 1705 1706 memset(digest, 0x00, SCTP_SIGNATURE_SIZE); 1707 if (crypto_hash_setkey(desc.tfm, key, keylen) || 1708 crypto_hash_digest(&desc, &sg, bodysize, digest)) { 1709 *error = -SCTP_IERROR_NOMEM; 1710 goto fail; 1711 } 1712 1713 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1714 /* Try the previous key. */ 1715 key = (char *)ep->secret_key[ep->last_key]; 1716 memset(digest, 0x00, SCTP_SIGNATURE_SIZE); 1717 if (crypto_hash_setkey(desc.tfm, key, keylen) || 1718 crypto_hash_digest(&desc, &sg, bodysize, digest)) { 1719 *error = -SCTP_IERROR_NOMEM; 1720 goto fail; 1721 } 1722 1723 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1724 /* Yikes! Still bad signature! */ 1725 *error = -SCTP_IERROR_BAD_SIG; 1726 goto fail; 1727 } 1728 } 1729 1730 no_hmac: 1731 /* IG Section 2.35.2: 1732 * 3) Compare the port numbers and the verification tag contained 1733 * within the COOKIE ECHO chunk to the actual port numbers and the 1734 * verification tag within the SCTP common header of the received 1735 * packet. If these values do not match the packet MUST be silently 1736 * discarded, 1737 */ 1738 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1739 *error = -SCTP_IERROR_BAD_TAG; 1740 goto fail; 1741 } 1742 1743 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1744 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1745 *error = -SCTP_IERROR_BAD_PORTS; 1746 goto fail; 1747 } 1748 1749 /* Check to see if the cookie is stale. If there is already 1750 * an association, there is no need to check cookie's expiration 1751 * for init collision case of lost COOKIE ACK. 1752 * If skb has been timestamped, then use the stamp, otherwise 1753 * use current time. This introduces a small possibility that 1754 * that a cookie may be considered expired, but his would only slow 1755 * down the new association establishment instead of every packet. 1756 */ 1757 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1758 skb_get_timestamp(skb, &tv); 1759 else 1760 do_gettimeofday(&tv); 1761 1762 if (!asoc && tv_lt(bear_cookie->expiration, tv)) { 1763 /* 1764 * Section 3.3.10.3 Stale Cookie Error (3) 1765 * 1766 * Cause of error 1767 * --------------- 1768 * Stale Cookie Error: Indicates the receipt of a valid State 1769 * Cookie that has expired. 1770 */ 1771 len = ntohs(chunk->chunk_hdr->length); 1772 *errp = sctp_make_op_error_space(asoc, chunk, len); 1773 if (*errp) { 1774 suseconds_t usecs = (tv.tv_sec - 1775 bear_cookie->expiration.tv_sec) * 1000000L + 1776 tv.tv_usec - bear_cookie->expiration.tv_usec; 1777 __be32 n = htonl(usecs); 1778 1779 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE, 1780 sizeof(n)); 1781 sctp_addto_chunk(*errp, sizeof(n), &n); 1782 *error = -SCTP_IERROR_STALE_COOKIE; 1783 } else 1784 *error = -SCTP_IERROR_NOMEM; 1785 1786 goto fail; 1787 } 1788 1789 /* Make a new base association. */ 1790 scope = sctp_scope(sctp_source(chunk)); 1791 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1792 if (!retval) { 1793 *error = -SCTP_IERROR_NOMEM; 1794 goto fail; 1795 } 1796 1797 /* Set up our peer's port number. */ 1798 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1799 1800 /* Populate the association from the cookie. */ 1801 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1802 1803 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1804 GFP_ATOMIC) < 0) { 1805 *error = -SCTP_IERROR_NOMEM; 1806 goto fail; 1807 } 1808 1809 /* Also, add the destination address. */ 1810 if (list_empty(&retval->base.bind_addr.address_list)) { 1811 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1812 SCTP_ADDR_SRC, GFP_ATOMIC); 1813 } 1814 1815 retval->next_tsn = retval->c.initial_tsn; 1816 retval->ctsn_ack_point = retval->next_tsn - 1; 1817 retval->addip_serial = retval->c.initial_tsn; 1818 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1819 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1820 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1821 1822 /* The INIT stuff will be done by the side effects. */ 1823 return retval; 1824 1825 fail: 1826 if (retval) 1827 sctp_association_free(retval); 1828 1829 return NULL; 1830 1831 malformed: 1832 /* Yikes! The packet is either corrupt or deliberately 1833 * malformed. 1834 */ 1835 *error = -SCTP_IERROR_MALFORMED; 1836 goto fail; 1837 } 1838 1839 /******************************************************************** 1840 * 3rd Level Abstractions 1841 ********************************************************************/ 1842 1843 struct __sctp_missing { 1844 __be32 num_missing; 1845 __be16 type; 1846 } __packed; 1847 1848 /* 1849 * Report a missing mandatory parameter. 1850 */ 1851 static int sctp_process_missing_param(const struct sctp_association *asoc, 1852 sctp_param_t paramtype, 1853 struct sctp_chunk *chunk, 1854 struct sctp_chunk **errp) 1855 { 1856 struct __sctp_missing report; 1857 __u16 len; 1858 1859 len = WORD_ROUND(sizeof(report)); 1860 1861 /* Make an ERROR chunk, preparing enough room for 1862 * returning multiple unknown parameters. 1863 */ 1864 if (!*errp) 1865 *errp = sctp_make_op_error_space(asoc, chunk, len); 1866 1867 if (*errp) { 1868 report.num_missing = htonl(1); 1869 report.type = paramtype; 1870 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1871 sizeof(report)); 1872 sctp_addto_chunk(*errp, sizeof(report), &report); 1873 } 1874 1875 /* Stop processing this chunk. */ 1876 return 0; 1877 } 1878 1879 /* Report an Invalid Mandatory Parameter. */ 1880 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1881 struct sctp_chunk *chunk, 1882 struct sctp_chunk **errp) 1883 { 1884 /* Invalid Mandatory Parameter Error has no payload. */ 1885 1886 if (!*errp) 1887 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1888 1889 if (*errp) 1890 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1891 1892 /* Stop processing this chunk. */ 1893 return 0; 1894 } 1895 1896 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1897 struct sctp_paramhdr *param, 1898 const struct sctp_chunk *chunk, 1899 struct sctp_chunk **errp) 1900 { 1901 /* This is a fatal error. Any accumulated non-fatal errors are 1902 * not reported. 1903 */ 1904 if (*errp) 1905 sctp_chunk_free(*errp); 1906 1907 /* Create an error chunk and fill it in with our payload. */ 1908 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1909 1910 return 0; 1911 } 1912 1913 1914 /* Do not attempt to handle the HOST_NAME parm. However, do 1915 * send back an indicator to the peer. 1916 */ 1917 static int sctp_process_hn_param(const struct sctp_association *asoc, 1918 union sctp_params param, 1919 struct sctp_chunk *chunk, 1920 struct sctp_chunk **errp) 1921 { 1922 __u16 len = ntohs(param.p->length); 1923 1924 /* Processing of the HOST_NAME parameter will generate an 1925 * ABORT. If we've accumulated any non-fatal errors, they 1926 * would be unrecognized parameters and we should not include 1927 * them in the ABORT. 1928 */ 1929 if (*errp) 1930 sctp_chunk_free(*errp); 1931 1932 *errp = sctp_make_op_error_space(asoc, chunk, len); 1933 1934 if (*errp) { 1935 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len); 1936 sctp_addto_chunk(*errp, len, param.v); 1937 } 1938 1939 /* Stop processing this chunk. */ 1940 return 0; 1941 } 1942 1943 static int sctp_verify_ext_param(struct net *net, union sctp_params param) 1944 { 1945 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 1946 int have_auth = 0; 1947 int have_asconf = 0; 1948 int i; 1949 1950 for (i = 0; i < num_ext; i++) { 1951 switch (param.ext->chunks[i]) { 1952 case SCTP_CID_AUTH: 1953 have_auth = 1; 1954 break; 1955 case SCTP_CID_ASCONF: 1956 case SCTP_CID_ASCONF_ACK: 1957 have_asconf = 1; 1958 break; 1959 } 1960 } 1961 1962 /* ADD-IP Security: The draft requires us to ABORT or ignore the 1963 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 1964 * only if ADD-IP is turned on and we are not backward-compatible 1965 * mode. 1966 */ 1967 if (sctp_addip_noauth) 1968 return 1; 1969 1970 if (sctp_addip_enable && !have_auth && have_asconf) 1971 return 0; 1972 1973 return 1; 1974 } 1975 1976 static void sctp_process_ext_param(struct sctp_association *asoc, 1977 union sctp_params param) 1978 { 1979 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 1980 int i; 1981 1982 for (i = 0; i < num_ext; i++) { 1983 switch (param.ext->chunks[i]) { 1984 case SCTP_CID_FWD_TSN: 1985 if (sctp_prsctp_enable && 1986 !asoc->peer.prsctp_capable) 1987 asoc->peer.prsctp_capable = 1; 1988 break; 1989 case SCTP_CID_AUTH: 1990 /* if the peer reports AUTH, assume that he 1991 * supports AUTH. 1992 */ 1993 if (sctp_auth_enable) 1994 asoc->peer.auth_capable = 1; 1995 break; 1996 case SCTP_CID_ASCONF: 1997 case SCTP_CID_ASCONF_ACK: 1998 if (sctp_addip_enable) 1999 asoc->peer.asconf_capable = 1; 2000 break; 2001 default: 2002 break; 2003 } 2004 } 2005 } 2006 2007 /* RFC 3.2.1 & the Implementers Guide 2.2. 2008 * 2009 * The Parameter Types are encoded such that the 2010 * highest-order two bits specify the action that must be 2011 * taken if the processing endpoint does not recognize the 2012 * Parameter Type. 2013 * 2014 * 00 - Stop processing this parameter; do not process any further 2015 * parameters within this chunk 2016 * 2017 * 01 - Stop processing this parameter, do not process any further 2018 * parameters within this chunk, and report the unrecognized 2019 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2020 * 2021 * 10 - Skip this parameter and continue processing. 2022 * 2023 * 11 - Skip this parameter and continue processing but 2024 * report the unrecognized parameter in an 2025 * 'Unrecognized Parameter' ERROR chunk. 2026 * 2027 * Return value: 2028 * SCTP_IERROR_NO_ERROR - continue with the chunk 2029 * SCTP_IERROR_ERROR - stop and report an error. 2030 * SCTP_IERROR_NOMEME - out of memory. 2031 */ 2032 static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc, 2033 union sctp_params param, 2034 struct sctp_chunk *chunk, 2035 struct sctp_chunk **errp) 2036 { 2037 int retval = SCTP_IERROR_NO_ERROR; 2038 2039 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2040 case SCTP_PARAM_ACTION_DISCARD: 2041 retval = SCTP_IERROR_ERROR; 2042 break; 2043 case SCTP_PARAM_ACTION_SKIP: 2044 break; 2045 case SCTP_PARAM_ACTION_DISCARD_ERR: 2046 retval = SCTP_IERROR_ERROR; 2047 /* Fall through */ 2048 case SCTP_PARAM_ACTION_SKIP_ERR: 2049 /* Make an ERROR chunk, preparing enough room for 2050 * returning multiple unknown parameters. 2051 */ 2052 if (NULL == *errp) 2053 *errp = sctp_make_op_error_fixed(asoc, chunk); 2054 2055 if (*errp) { 2056 if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2057 WORD_ROUND(ntohs(param.p->length)))) 2058 sctp_addto_chunk_fixed(*errp, 2059 WORD_ROUND(ntohs(param.p->length)), 2060 param.v); 2061 } else { 2062 /* If there is no memory for generating the ERROR 2063 * report as specified, an ABORT will be triggered 2064 * to the peer and the association won't be 2065 * established. 2066 */ 2067 retval = SCTP_IERROR_NOMEM; 2068 } 2069 break; 2070 default: 2071 break; 2072 } 2073 2074 return retval; 2075 } 2076 2077 /* Verify variable length parameters 2078 * Return values: 2079 * SCTP_IERROR_ABORT - trigger an ABORT 2080 * SCTP_IERROR_NOMEM - out of memory (abort) 2081 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2082 * SCTP_IERROR_NO_ERROR - continue with the chunk 2083 */ 2084 static sctp_ierror_t sctp_verify_param(struct net *net, 2085 const struct sctp_association *asoc, 2086 union sctp_params param, 2087 sctp_cid_t cid, 2088 struct sctp_chunk *chunk, 2089 struct sctp_chunk **err_chunk) 2090 { 2091 struct sctp_hmac_algo_param *hmacs; 2092 int retval = SCTP_IERROR_NO_ERROR; 2093 __u16 n_elt, id = 0; 2094 int i; 2095 2096 /* FIXME - This routine is not looking at each parameter per the 2097 * chunk type, i.e., unrecognized parameters should be further 2098 * identified based on the chunk id. 2099 */ 2100 2101 switch (param.p->type) { 2102 case SCTP_PARAM_IPV4_ADDRESS: 2103 case SCTP_PARAM_IPV6_ADDRESS: 2104 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2105 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2106 case SCTP_PARAM_STATE_COOKIE: 2107 case SCTP_PARAM_HEARTBEAT_INFO: 2108 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2109 case SCTP_PARAM_ECN_CAPABLE: 2110 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2111 break; 2112 2113 case SCTP_PARAM_SUPPORTED_EXT: 2114 if (!sctp_verify_ext_param(net, param)) 2115 return SCTP_IERROR_ABORT; 2116 break; 2117 2118 case SCTP_PARAM_SET_PRIMARY: 2119 if (sctp_addip_enable) 2120 break; 2121 goto fallthrough; 2122 2123 case SCTP_PARAM_HOST_NAME_ADDRESS: 2124 /* Tell the peer, we won't support this param. */ 2125 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2126 retval = SCTP_IERROR_ABORT; 2127 break; 2128 2129 case SCTP_PARAM_FWD_TSN_SUPPORT: 2130 if (sctp_prsctp_enable) 2131 break; 2132 goto fallthrough; 2133 2134 case SCTP_PARAM_RANDOM: 2135 if (!sctp_auth_enable) 2136 goto fallthrough; 2137 2138 /* SCTP-AUTH: Secion 6.1 2139 * If the random number is not 32 byte long the association 2140 * MUST be aborted. The ABORT chunk SHOULD contain the error 2141 * cause 'Protocol Violation'. 2142 */ 2143 if (SCTP_AUTH_RANDOM_LENGTH != 2144 ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) { 2145 sctp_process_inv_paramlength(asoc, param.p, 2146 chunk, err_chunk); 2147 retval = SCTP_IERROR_ABORT; 2148 } 2149 break; 2150 2151 case SCTP_PARAM_CHUNKS: 2152 if (!sctp_auth_enable) 2153 goto fallthrough; 2154 2155 /* SCTP-AUTH: Section 3.2 2156 * The CHUNKS parameter MUST be included once in the INIT or 2157 * INIT-ACK chunk if the sender wants to receive authenticated 2158 * chunks. Its maximum length is 260 bytes. 2159 */ 2160 if (260 < ntohs(param.p->length)) { 2161 sctp_process_inv_paramlength(asoc, param.p, 2162 chunk, err_chunk); 2163 retval = SCTP_IERROR_ABORT; 2164 } 2165 break; 2166 2167 case SCTP_PARAM_HMAC_ALGO: 2168 if (!sctp_auth_enable) 2169 goto fallthrough; 2170 2171 hmacs = (struct sctp_hmac_algo_param *)param.p; 2172 n_elt = (ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) >> 1; 2173 2174 /* SCTP-AUTH: Section 6.1 2175 * The HMAC algorithm based on SHA-1 MUST be supported and 2176 * included in the HMAC-ALGO parameter. 2177 */ 2178 for (i = 0; i < n_elt; i++) { 2179 id = ntohs(hmacs->hmac_ids[i]); 2180 2181 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2182 break; 2183 } 2184 2185 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2186 sctp_process_inv_paramlength(asoc, param.p, chunk, 2187 err_chunk); 2188 retval = SCTP_IERROR_ABORT; 2189 } 2190 break; 2191 fallthrough: 2192 default: 2193 SCTP_DEBUG_PRINTK("Unrecognized param: %d for chunk %d.\n", 2194 ntohs(param.p->type), cid); 2195 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2196 break; 2197 } 2198 return retval; 2199 } 2200 2201 /* Verify the INIT packet before we process it. */ 2202 int sctp_verify_init(struct net *net, const struct sctp_association *asoc, 2203 sctp_cid_t cid, 2204 sctp_init_chunk_t *peer_init, 2205 struct sctp_chunk *chunk, 2206 struct sctp_chunk **errp) 2207 { 2208 union sctp_params param; 2209 int has_cookie = 0; 2210 int result; 2211 2212 /* Verify stream values are non-zero. */ 2213 if ((0 == peer_init->init_hdr.num_outbound_streams) || 2214 (0 == peer_init->init_hdr.num_inbound_streams) || 2215 (0 == peer_init->init_hdr.init_tag) || 2216 (SCTP_DEFAULT_MINWINDOW > ntohl(peer_init->init_hdr.a_rwnd))) { 2217 2218 return sctp_process_inv_mandatory(asoc, chunk, errp); 2219 } 2220 2221 /* Check for missing mandatory parameters. */ 2222 sctp_walk_params(param, peer_init, init_hdr.params) { 2223 2224 if (SCTP_PARAM_STATE_COOKIE == param.p->type) 2225 has_cookie = 1; 2226 2227 } /* for (loop through all parameters) */ 2228 2229 /* There is a possibility that a parameter length was bad and 2230 * in that case we would have stoped walking the parameters. 2231 * The current param.p would point at the bad one. 2232 * Current consensus on the mailing list is to generate a PROTOCOL 2233 * VIOLATION error. We build the ERROR chunk here and let the normal 2234 * error handling code build and send the packet. 2235 */ 2236 if (param.v != (void*)chunk->chunk_end) 2237 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2238 2239 /* The only missing mandatory param possible today is 2240 * the state cookie for an INIT-ACK chunk. 2241 */ 2242 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2243 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2244 chunk, errp); 2245 2246 /* Verify all the variable length parameters */ 2247 sctp_walk_params(param, peer_init, init_hdr.params) { 2248 2249 result = sctp_verify_param(net, asoc, param, cid, chunk, errp); 2250 switch (result) { 2251 case SCTP_IERROR_ABORT: 2252 case SCTP_IERROR_NOMEM: 2253 return 0; 2254 case SCTP_IERROR_ERROR: 2255 return 1; 2256 case SCTP_IERROR_NO_ERROR: 2257 default: 2258 break; 2259 } 2260 2261 } /* for (loop through all parameters) */ 2262 2263 return 1; 2264 } 2265 2266 /* Unpack the parameters in an INIT packet into an association. 2267 * Returns 0 on failure, else success. 2268 * FIXME: This is an association method. 2269 */ 2270 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2271 const union sctp_addr *peer_addr, 2272 sctp_init_chunk_t *peer_init, gfp_t gfp) 2273 { 2274 union sctp_params param; 2275 struct sctp_transport *transport; 2276 struct list_head *pos, *temp; 2277 struct sctp_af *af; 2278 union sctp_addr addr; 2279 char *cookie; 2280 int src_match = 0; 2281 2282 /* We must include the address that the INIT packet came from. 2283 * This is the only address that matters for an INIT packet. 2284 * When processing a COOKIE ECHO, we retrieve the from address 2285 * of the INIT from the cookie. 2286 */ 2287 2288 /* This implementation defaults to making the first transport 2289 * added as the primary transport. The source address seems to 2290 * be a a better choice than any of the embedded addresses. 2291 */ 2292 if(!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2293 goto nomem; 2294 2295 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2296 src_match = 1; 2297 2298 /* Process the initialization parameters. */ 2299 sctp_walk_params(param, peer_init, init_hdr.params) { 2300 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2301 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2302 af = sctp_get_af_specific(param_type2af(param.p->type)); 2303 af->from_addr_param(&addr, param.addr, 2304 chunk->sctp_hdr->source, 0); 2305 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2306 src_match = 1; 2307 } 2308 2309 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2310 goto clean_up; 2311 } 2312 2313 /* source address of chunk may not match any valid address */ 2314 if (!src_match) 2315 goto clean_up; 2316 2317 /* AUTH: After processing the parameters, make sure that we 2318 * have all the required info to potentially do authentications. 2319 */ 2320 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2321 !asoc->peer.peer_hmacs)) 2322 asoc->peer.auth_capable = 0; 2323 2324 /* In a non-backward compatible mode, if the peer claims 2325 * support for ADD-IP but not AUTH, the ADD-IP spec states 2326 * that we MUST ABORT the association. Section 6. The section 2327 * also give us an option to silently ignore the packet, which 2328 * is what we'll do here. 2329 */ 2330 if (!sctp_addip_noauth && 2331 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2332 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2333 SCTP_PARAM_DEL_IP | 2334 SCTP_PARAM_SET_PRIMARY); 2335 asoc->peer.asconf_capable = 0; 2336 goto clean_up; 2337 } 2338 2339 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2340 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2341 transport = list_entry(pos, struct sctp_transport, transports); 2342 if (transport->state == SCTP_UNKNOWN) { 2343 sctp_assoc_rm_peer(asoc, transport); 2344 } 2345 } 2346 2347 /* The fixed INIT headers are always in network byte 2348 * order. 2349 */ 2350 asoc->peer.i.init_tag = 2351 ntohl(peer_init->init_hdr.init_tag); 2352 asoc->peer.i.a_rwnd = 2353 ntohl(peer_init->init_hdr.a_rwnd); 2354 asoc->peer.i.num_outbound_streams = 2355 ntohs(peer_init->init_hdr.num_outbound_streams); 2356 asoc->peer.i.num_inbound_streams = 2357 ntohs(peer_init->init_hdr.num_inbound_streams); 2358 asoc->peer.i.initial_tsn = 2359 ntohl(peer_init->init_hdr.initial_tsn); 2360 2361 /* Apply the upper bounds for output streams based on peer's 2362 * number of inbound streams. 2363 */ 2364 if (asoc->c.sinit_num_ostreams > 2365 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2366 asoc->c.sinit_num_ostreams = 2367 ntohs(peer_init->init_hdr.num_inbound_streams); 2368 } 2369 2370 if (asoc->c.sinit_max_instreams > 2371 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2372 asoc->c.sinit_max_instreams = 2373 ntohs(peer_init->init_hdr.num_outbound_streams); 2374 } 2375 2376 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2377 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2378 2379 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2380 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2381 2382 /* Copy cookie in case we need to resend COOKIE-ECHO. */ 2383 cookie = asoc->peer.cookie; 2384 if (cookie) { 2385 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp); 2386 if (!asoc->peer.cookie) 2387 goto clean_up; 2388 } 2389 2390 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2391 * high (for example, implementations MAY use the size of the receiver 2392 * advertised window). 2393 */ 2394 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2395 transports) { 2396 transport->ssthresh = asoc->peer.i.a_rwnd; 2397 } 2398 2399 /* Set up the TSN tracking pieces. */ 2400 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2401 asoc->peer.i.initial_tsn, gfp)) 2402 goto clean_up; 2403 2404 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2405 * 2406 * The stream sequence number in all the streams shall start 2407 * from 0 when the association is established. Also, when the 2408 * stream sequence number reaches the value 65535 the next 2409 * stream sequence number shall be set to 0. 2410 */ 2411 2412 /* Allocate storage for the negotiated streams if it is not a temporary 2413 * association. 2414 */ 2415 if (!asoc->temp) { 2416 int error; 2417 2418 asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams, 2419 asoc->c.sinit_num_ostreams, gfp); 2420 if (!asoc->ssnmap) 2421 goto clean_up; 2422 2423 error = sctp_assoc_set_id(asoc, gfp); 2424 if (error) 2425 goto clean_up; 2426 } 2427 2428 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2429 * 2430 * When an endpoint has an ASCONF signaled change to be sent to the 2431 * remote endpoint it should do the following: 2432 * ... 2433 * A2) A serial number should be assigned to the Chunk. The serial 2434 * number should be a monotonically increasing number. All serial 2435 * numbers are defined to be initialized at the start of the 2436 * association to the same value as the Initial TSN. 2437 */ 2438 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2439 return 1; 2440 2441 clean_up: 2442 /* Release the transport structures. */ 2443 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2444 transport = list_entry(pos, struct sctp_transport, transports); 2445 if (transport->state != SCTP_ACTIVE) 2446 sctp_assoc_rm_peer(asoc, transport); 2447 } 2448 2449 nomem: 2450 return 0; 2451 } 2452 2453 2454 /* Update asoc with the option described in param. 2455 * 2456 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2457 * 2458 * asoc is the association to update. 2459 * param is the variable length parameter to use for update. 2460 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2461 * If the current packet is an INIT we want to minimize the amount of 2462 * work we do. In particular, we should not build transport 2463 * structures for the addresses. 2464 */ 2465 static int sctp_process_param(struct sctp_association *asoc, 2466 union sctp_params param, 2467 const union sctp_addr *peer_addr, 2468 gfp_t gfp) 2469 { 2470 struct net *net = sock_net(asoc->base.sk); 2471 union sctp_addr addr; 2472 int i; 2473 __u16 sat; 2474 int retval = 1; 2475 sctp_scope_t scope; 2476 time_t stale; 2477 struct sctp_af *af; 2478 union sctp_addr_param *addr_param; 2479 struct sctp_transport *t; 2480 2481 /* We maintain all INIT parameters in network byte order all the 2482 * time. This allows us to not worry about whether the parameters 2483 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2484 */ 2485 switch (param.p->type) { 2486 case SCTP_PARAM_IPV6_ADDRESS: 2487 if (PF_INET6 != asoc->base.sk->sk_family) 2488 break; 2489 goto do_addr_param; 2490 2491 case SCTP_PARAM_IPV4_ADDRESS: 2492 /* v4 addresses are not allowed on v6-only socket */ 2493 if (ipv6_only_sock(asoc->base.sk)) 2494 break; 2495 do_addr_param: 2496 af = sctp_get_af_specific(param_type2af(param.p->type)); 2497 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); 2498 scope = sctp_scope(peer_addr); 2499 if (sctp_in_scope(net, &addr, scope)) 2500 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2501 return 0; 2502 break; 2503 2504 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2505 if (!sctp_cookie_preserve_enable) 2506 break; 2507 2508 stale = ntohl(param.life->lifespan_increment); 2509 2510 /* Suggested Cookie Life span increment's unit is msec, 2511 * (1/1000sec). 2512 */ 2513 asoc->cookie_life.tv_sec += stale / 1000; 2514 asoc->cookie_life.tv_usec += (stale % 1000) * 1000; 2515 break; 2516 2517 case SCTP_PARAM_HOST_NAME_ADDRESS: 2518 SCTP_DEBUG_PRINTK("unimplemented SCTP_HOST_NAME_ADDRESS\n"); 2519 break; 2520 2521 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2522 /* Turn off the default values first so we'll know which 2523 * ones are really set by the peer. 2524 */ 2525 asoc->peer.ipv4_address = 0; 2526 asoc->peer.ipv6_address = 0; 2527 2528 /* Assume that peer supports the address family 2529 * by which it sends a packet. 2530 */ 2531 if (peer_addr->sa.sa_family == AF_INET6) 2532 asoc->peer.ipv6_address = 1; 2533 else if (peer_addr->sa.sa_family == AF_INET) 2534 asoc->peer.ipv4_address = 1; 2535 2536 /* Cycle through address types; avoid divide by 0. */ 2537 sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2538 if (sat) 2539 sat /= sizeof(__u16); 2540 2541 for (i = 0; i < sat; ++i) { 2542 switch (param.sat->types[i]) { 2543 case SCTP_PARAM_IPV4_ADDRESS: 2544 asoc->peer.ipv4_address = 1; 2545 break; 2546 2547 case SCTP_PARAM_IPV6_ADDRESS: 2548 if (PF_INET6 == asoc->base.sk->sk_family) 2549 asoc->peer.ipv6_address = 1; 2550 break; 2551 2552 case SCTP_PARAM_HOST_NAME_ADDRESS: 2553 asoc->peer.hostname_address = 1; 2554 break; 2555 2556 default: /* Just ignore anything else. */ 2557 break; 2558 } 2559 } 2560 break; 2561 2562 case SCTP_PARAM_STATE_COOKIE: 2563 asoc->peer.cookie_len = 2564 ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2565 asoc->peer.cookie = param.cookie->body; 2566 break; 2567 2568 case SCTP_PARAM_HEARTBEAT_INFO: 2569 /* Would be odd to receive, but it causes no problems. */ 2570 break; 2571 2572 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2573 /* Rejected during verify stage. */ 2574 break; 2575 2576 case SCTP_PARAM_ECN_CAPABLE: 2577 asoc->peer.ecn_capable = 1; 2578 break; 2579 2580 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2581 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2582 break; 2583 2584 case SCTP_PARAM_SET_PRIMARY: 2585 if (!sctp_addip_enable) 2586 goto fall_through; 2587 2588 addr_param = param.v + sizeof(sctp_addip_param_t); 2589 2590 af = sctp_get_af_specific(param_type2af(param.p->type)); 2591 af->from_addr_param(&addr, addr_param, 2592 htons(asoc->peer.port), 0); 2593 2594 /* if the address is invalid, we can't process it. 2595 * XXX: see spec for what to do. 2596 */ 2597 if (!af->addr_valid(&addr, NULL, NULL)) 2598 break; 2599 2600 t = sctp_assoc_lookup_paddr(asoc, &addr); 2601 if (!t) 2602 break; 2603 2604 sctp_assoc_set_primary(asoc, t); 2605 break; 2606 2607 case SCTP_PARAM_SUPPORTED_EXT: 2608 sctp_process_ext_param(asoc, param); 2609 break; 2610 2611 case SCTP_PARAM_FWD_TSN_SUPPORT: 2612 if (sctp_prsctp_enable) { 2613 asoc->peer.prsctp_capable = 1; 2614 break; 2615 } 2616 /* Fall Through */ 2617 goto fall_through; 2618 2619 case SCTP_PARAM_RANDOM: 2620 if (!sctp_auth_enable) 2621 goto fall_through; 2622 2623 /* Save peer's random parameter */ 2624 asoc->peer.peer_random = kmemdup(param.p, 2625 ntohs(param.p->length), gfp); 2626 if (!asoc->peer.peer_random) { 2627 retval = 0; 2628 break; 2629 } 2630 break; 2631 2632 case SCTP_PARAM_HMAC_ALGO: 2633 if (!sctp_auth_enable) 2634 goto fall_through; 2635 2636 /* Save peer's HMAC list */ 2637 asoc->peer.peer_hmacs = kmemdup(param.p, 2638 ntohs(param.p->length), gfp); 2639 if (!asoc->peer.peer_hmacs) { 2640 retval = 0; 2641 break; 2642 } 2643 2644 /* Set the default HMAC the peer requested*/ 2645 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2646 break; 2647 2648 case SCTP_PARAM_CHUNKS: 2649 if (!sctp_auth_enable) 2650 goto fall_through; 2651 2652 asoc->peer.peer_chunks = kmemdup(param.p, 2653 ntohs(param.p->length), gfp); 2654 if (!asoc->peer.peer_chunks) 2655 retval = 0; 2656 break; 2657 fall_through: 2658 default: 2659 /* Any unrecognized parameters should have been caught 2660 * and handled by sctp_verify_param() which should be 2661 * called prior to this routine. Simply log the error 2662 * here. 2663 */ 2664 SCTP_DEBUG_PRINTK("Ignoring param: %d for association %p.\n", 2665 ntohs(param.p->type), asoc); 2666 break; 2667 } 2668 2669 return retval; 2670 } 2671 2672 /* Select a new verification tag. */ 2673 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2674 { 2675 /* I believe that this random number generator complies with RFC1750. 2676 * A tag of 0 is reserved for special cases (e.g. INIT). 2677 */ 2678 __u32 x; 2679 2680 do { 2681 get_random_bytes(&x, sizeof(__u32)); 2682 } while (x == 0); 2683 2684 return x; 2685 } 2686 2687 /* Select an initial TSN to send during startup. */ 2688 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2689 { 2690 __u32 retval; 2691 2692 get_random_bytes(&retval, sizeof(__u32)); 2693 return retval; 2694 } 2695 2696 /* 2697 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2698 * 0 1 2 3 2699 * 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 2700 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2701 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2702 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2703 * | Serial Number | 2704 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2705 * | Address Parameter | 2706 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2707 * | ASCONF Parameter #1 | 2708 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2709 * \ \ 2710 * / .... / 2711 * \ \ 2712 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2713 * | ASCONF Parameter #N | 2714 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2715 * 2716 * Address Parameter and other parameter will not be wrapped in this function 2717 */ 2718 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2719 union sctp_addr *addr, 2720 int vparam_len) 2721 { 2722 sctp_addiphdr_t asconf; 2723 struct sctp_chunk *retval; 2724 int length = sizeof(asconf) + vparam_len; 2725 union sctp_addr_param addrparam; 2726 int addrlen; 2727 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2728 2729 addrlen = af->to_addr_param(addr, &addrparam); 2730 if (!addrlen) 2731 return NULL; 2732 length += addrlen; 2733 2734 /* Create the chunk. */ 2735 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF, 0, length); 2736 if (!retval) 2737 return NULL; 2738 2739 asconf.serial = htonl(asoc->addip_serial++); 2740 2741 retval->subh.addip_hdr = 2742 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2743 retval->param_hdr.v = 2744 sctp_addto_chunk(retval, addrlen, &addrparam); 2745 2746 return retval; 2747 } 2748 2749 /* ADDIP 2750 * 3.2.1 Add IP Address 2751 * 0 1 2 3 2752 * 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 2753 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2754 * | Type = 0xC001 | Length = Variable | 2755 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2756 * | ASCONF-Request Correlation ID | 2757 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2758 * | Address Parameter | 2759 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2760 * 2761 * 3.2.2 Delete IP Address 2762 * 0 1 2 3 2763 * 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 2764 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2765 * | Type = 0xC002 | Length = Variable | 2766 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2767 * | ASCONF-Request Correlation ID | 2768 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2769 * | Address Parameter | 2770 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2771 * 2772 */ 2773 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2774 union sctp_addr *laddr, 2775 struct sockaddr *addrs, 2776 int addrcnt, 2777 __be16 flags) 2778 { 2779 sctp_addip_param_t param; 2780 struct sctp_chunk *retval; 2781 union sctp_addr_param addr_param; 2782 union sctp_addr *addr; 2783 void *addr_buf; 2784 struct sctp_af *af; 2785 int paramlen = sizeof(param); 2786 int addr_param_len = 0; 2787 int totallen = 0; 2788 int i; 2789 int del_pickup = 0; 2790 2791 /* Get total length of all the address parameters. */ 2792 addr_buf = addrs; 2793 for (i = 0; i < addrcnt; i++) { 2794 addr = addr_buf; 2795 af = sctp_get_af_specific(addr->v4.sin_family); 2796 addr_param_len = af->to_addr_param(addr, &addr_param); 2797 2798 totallen += paramlen; 2799 totallen += addr_param_len; 2800 2801 addr_buf += af->sockaddr_len; 2802 if (asoc->asconf_addr_del_pending && !del_pickup) { 2803 /* reuse the parameter length from the same scope one */ 2804 totallen += paramlen; 2805 totallen += addr_param_len; 2806 del_pickup = 1; 2807 SCTP_DEBUG_PRINTK("mkasconf_update_ip: picked same-scope del_pending addr, totallen for all addresses is %d\n", totallen); 2808 } 2809 } 2810 2811 /* Create an asconf chunk with the required length. */ 2812 retval = sctp_make_asconf(asoc, laddr, totallen); 2813 if (!retval) 2814 return NULL; 2815 2816 /* Add the address parameters to the asconf chunk. */ 2817 addr_buf = addrs; 2818 for (i = 0; i < addrcnt; i++) { 2819 addr = addr_buf; 2820 af = sctp_get_af_specific(addr->v4.sin_family); 2821 addr_param_len = af->to_addr_param(addr, &addr_param); 2822 param.param_hdr.type = flags; 2823 param.param_hdr.length = htons(paramlen + addr_param_len); 2824 param.crr_id = i; 2825 2826 sctp_addto_chunk(retval, paramlen, ¶m); 2827 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2828 2829 addr_buf += af->sockaddr_len; 2830 } 2831 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2832 addr = asoc->asconf_addr_del_pending; 2833 af = sctp_get_af_specific(addr->v4.sin_family); 2834 addr_param_len = af->to_addr_param(addr, &addr_param); 2835 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2836 param.param_hdr.length = htons(paramlen + addr_param_len); 2837 param.crr_id = i; 2838 2839 sctp_addto_chunk(retval, paramlen, ¶m); 2840 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2841 } 2842 return retval; 2843 } 2844 2845 /* ADDIP 2846 * 3.2.4 Set Primary IP Address 2847 * 0 1 2 3 2848 * 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 2849 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2850 * | Type =0xC004 | Length = Variable | 2851 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2852 * | ASCONF-Request Correlation ID | 2853 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2854 * | Address Parameter | 2855 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2856 * 2857 * Create an ASCONF chunk with Set Primary IP address parameter. 2858 */ 2859 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2860 union sctp_addr *addr) 2861 { 2862 sctp_addip_param_t param; 2863 struct sctp_chunk *retval; 2864 int len = sizeof(param); 2865 union sctp_addr_param addrparam; 2866 int addrlen; 2867 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2868 2869 addrlen = af->to_addr_param(addr, &addrparam); 2870 if (!addrlen) 2871 return NULL; 2872 len += addrlen; 2873 2874 /* Create the chunk and make asconf header. */ 2875 retval = sctp_make_asconf(asoc, addr, len); 2876 if (!retval) 2877 return NULL; 2878 2879 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2880 param.param_hdr.length = htons(len); 2881 param.crr_id = 0; 2882 2883 sctp_addto_chunk(retval, sizeof(param), ¶m); 2884 sctp_addto_chunk(retval, addrlen, &addrparam); 2885 2886 return retval; 2887 } 2888 2889 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2890 * 0 1 2 3 2891 * 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 2892 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2893 * | Type = 0x80 | Chunk Flags | Chunk Length | 2894 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2895 * | Serial Number | 2896 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2897 * | ASCONF Parameter Response#1 | 2898 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2899 * \ \ 2900 * / .... / 2901 * \ \ 2902 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2903 * | ASCONF Parameter Response#N | 2904 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2905 * 2906 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2907 */ 2908 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2909 __u32 serial, int vparam_len) 2910 { 2911 sctp_addiphdr_t asconf; 2912 struct sctp_chunk *retval; 2913 int length = sizeof(asconf) + vparam_len; 2914 2915 /* Create the chunk. */ 2916 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF_ACK, 0, length); 2917 if (!retval) 2918 return NULL; 2919 2920 asconf.serial = htonl(serial); 2921 2922 retval->subh.addip_hdr = 2923 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2924 2925 return retval; 2926 } 2927 2928 /* Add response parameters to an ASCONF_ACK chunk. */ 2929 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2930 __be16 err_code, sctp_addip_param_t *asconf_param) 2931 { 2932 sctp_addip_param_t ack_param; 2933 sctp_errhdr_t err_param; 2934 int asconf_param_len = 0; 2935 int err_param_len = 0; 2936 __be16 response_type; 2937 2938 if (SCTP_ERROR_NO_ERROR == err_code) { 2939 response_type = SCTP_PARAM_SUCCESS_REPORT; 2940 } else { 2941 response_type = SCTP_PARAM_ERR_CAUSE; 2942 err_param_len = sizeof(err_param); 2943 if (asconf_param) 2944 asconf_param_len = 2945 ntohs(asconf_param->param_hdr.length); 2946 } 2947 2948 /* Add Success Indication or Error Cause Indication parameter. */ 2949 ack_param.param_hdr.type = response_type; 2950 ack_param.param_hdr.length = htons(sizeof(ack_param) + 2951 err_param_len + 2952 asconf_param_len); 2953 ack_param.crr_id = crr_id; 2954 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 2955 2956 if (SCTP_ERROR_NO_ERROR == err_code) 2957 return; 2958 2959 /* Add Error Cause parameter. */ 2960 err_param.cause = err_code; 2961 err_param.length = htons(err_param_len + asconf_param_len); 2962 sctp_addto_chunk(chunk, err_param_len, &err_param); 2963 2964 /* Add the failed TLV copied from ASCONF chunk. */ 2965 if (asconf_param) 2966 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 2967 } 2968 2969 /* Process a asconf parameter. */ 2970 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 2971 struct sctp_chunk *asconf, 2972 sctp_addip_param_t *asconf_param) 2973 { 2974 struct sctp_transport *peer; 2975 struct sctp_af *af; 2976 union sctp_addr addr; 2977 union sctp_addr_param *addr_param; 2978 2979 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t); 2980 2981 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 2982 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 2983 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 2984 return SCTP_ERROR_UNKNOWN_PARAM; 2985 2986 switch (addr_param->p.type) { 2987 case SCTP_PARAM_IPV6_ADDRESS: 2988 if (!asoc->peer.ipv6_address) 2989 return SCTP_ERROR_DNS_FAILED; 2990 break; 2991 case SCTP_PARAM_IPV4_ADDRESS: 2992 if (!asoc->peer.ipv4_address) 2993 return SCTP_ERROR_DNS_FAILED; 2994 break; 2995 default: 2996 return SCTP_ERROR_DNS_FAILED; 2997 } 2998 2999 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3000 if (unlikely(!af)) 3001 return SCTP_ERROR_DNS_FAILED; 3002 3003 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); 3004 3005 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3006 * or multicast address. 3007 * (note: wildcard is permitted and requires special handling so 3008 * make sure we check for that) 3009 */ 3010 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3011 return SCTP_ERROR_DNS_FAILED; 3012 3013 switch (asconf_param->param_hdr.type) { 3014 case SCTP_PARAM_ADD_IP: 3015 /* Section 4.2.1: 3016 * If the address 0.0.0.0 or ::0 is provided, the source 3017 * address of the packet MUST be added. 3018 */ 3019 if (af->is_any(&addr)) 3020 memcpy(&addr, &asconf->source, sizeof(addr)); 3021 3022 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3023 * request and does not have the local resources to add this 3024 * new address to the association, it MUST return an Error 3025 * Cause TLV set to the new error code 'Operation Refused 3026 * Due to Resource Shortage'. 3027 */ 3028 3029 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3030 if (!peer) 3031 return SCTP_ERROR_RSRC_LOW; 3032 3033 /* Start the heartbeat timer. */ 3034 if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer))) 3035 sctp_transport_hold(peer); 3036 asoc->new_transport = peer; 3037 break; 3038 case SCTP_PARAM_DEL_IP: 3039 /* ADDIP 4.3 D7) If a request is received to delete the 3040 * last remaining IP address of a peer endpoint, the receiver 3041 * MUST send an Error Cause TLV with the error cause set to the 3042 * new error code 'Request to Delete Last Remaining IP Address'. 3043 */ 3044 if (asoc->peer.transport_count == 1) 3045 return SCTP_ERROR_DEL_LAST_IP; 3046 3047 /* ADDIP 4.3 D8) If a request is received to delete an IP 3048 * address which is also the source address of the IP packet 3049 * which contained the ASCONF chunk, the receiver MUST reject 3050 * this request. To reject the request the receiver MUST send 3051 * an Error Cause TLV set to the new error code 'Request to 3052 * Delete Source IP Address' 3053 */ 3054 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3055 return SCTP_ERROR_DEL_SRC_IP; 3056 3057 /* Section 4.2.2 3058 * If the address 0.0.0.0 or ::0 is provided, all 3059 * addresses of the peer except the source address of the 3060 * packet MUST be deleted. 3061 */ 3062 if (af->is_any(&addr)) { 3063 sctp_assoc_set_primary(asoc, asconf->transport); 3064 sctp_assoc_del_nonprimary_peers(asoc, 3065 asconf->transport); 3066 } else 3067 sctp_assoc_del_peer(asoc, &addr); 3068 break; 3069 case SCTP_PARAM_SET_PRIMARY: 3070 /* ADDIP Section 4.2.4 3071 * If the address 0.0.0.0 or ::0 is provided, the receiver 3072 * MAY mark the source address of the packet as its 3073 * primary. 3074 */ 3075 if (af->is_any(&addr)) 3076 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr)); 3077 3078 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3079 if (!peer) 3080 return SCTP_ERROR_DNS_FAILED; 3081 3082 sctp_assoc_set_primary(asoc, peer); 3083 break; 3084 } 3085 3086 return SCTP_ERROR_NO_ERROR; 3087 } 3088 3089 /* Verify the ASCONF packet before we process it. */ 3090 int sctp_verify_asconf(const struct sctp_association *asoc, 3091 struct sctp_paramhdr *param_hdr, void *chunk_end, 3092 struct sctp_paramhdr **errp) { 3093 sctp_addip_param_t *asconf_param; 3094 union sctp_params param; 3095 int length, plen; 3096 3097 param.v = (sctp_paramhdr_t *) param_hdr; 3098 while (param.v <= chunk_end - sizeof(sctp_paramhdr_t)) { 3099 length = ntohs(param.p->length); 3100 *errp = param.p; 3101 3102 if (param.v > chunk_end - length || 3103 length < sizeof(sctp_paramhdr_t)) 3104 return 0; 3105 3106 switch (param.p->type) { 3107 case SCTP_PARAM_ADD_IP: 3108 case SCTP_PARAM_DEL_IP: 3109 case SCTP_PARAM_SET_PRIMARY: 3110 asconf_param = (sctp_addip_param_t *)param.v; 3111 plen = ntohs(asconf_param->param_hdr.length); 3112 if (plen < sizeof(sctp_addip_param_t) + 3113 sizeof(sctp_paramhdr_t)) 3114 return 0; 3115 break; 3116 case SCTP_PARAM_SUCCESS_REPORT: 3117 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3118 if (length != sizeof(sctp_addip_param_t)) 3119 return 0; 3120 3121 break; 3122 default: 3123 break; 3124 } 3125 3126 param.v += WORD_ROUND(length); 3127 } 3128 3129 if (param.v != chunk_end) 3130 return 0; 3131 3132 return 1; 3133 } 3134 3135 /* Process an incoming ASCONF chunk with the next expected serial no. and 3136 * return an ASCONF_ACK chunk to be sent in response. 3137 */ 3138 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3139 struct sctp_chunk *asconf) 3140 { 3141 sctp_addiphdr_t *hdr; 3142 union sctp_addr_param *addr_param; 3143 sctp_addip_param_t *asconf_param; 3144 struct sctp_chunk *asconf_ack; 3145 3146 __be16 err_code; 3147 int length = 0; 3148 int chunk_len; 3149 __u32 serial; 3150 int all_param_pass = 1; 3151 3152 chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t); 3153 hdr = (sctp_addiphdr_t *)asconf->skb->data; 3154 serial = ntohl(hdr->serial); 3155 3156 /* Skip the addiphdr and store a pointer to address parameter. */ 3157 length = sizeof(sctp_addiphdr_t); 3158 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3159 chunk_len -= length; 3160 3161 /* Skip the address parameter and store a pointer to the first 3162 * asconf parameter. 3163 */ 3164 length = ntohs(addr_param->p.length); 3165 asconf_param = (void *)addr_param + length; 3166 chunk_len -= length; 3167 3168 /* create an ASCONF_ACK chunk. 3169 * Based on the definitions of parameters, we know that the size of 3170 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3171 * parameters. 3172 */ 3173 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3174 if (!asconf_ack) 3175 goto done; 3176 3177 /* Process the TLVs contained within the ASCONF chunk. */ 3178 while (chunk_len > 0) { 3179 err_code = sctp_process_asconf_param(asoc, asconf, 3180 asconf_param); 3181 /* ADDIP 4.1 A7) 3182 * If an error response is received for a TLV parameter, 3183 * all TLVs with no response before the failed TLV are 3184 * considered successful if not reported. All TLVs after 3185 * the failed response are considered unsuccessful unless 3186 * a specific success indication is present for the parameter. 3187 */ 3188 if (SCTP_ERROR_NO_ERROR != err_code) 3189 all_param_pass = 0; 3190 3191 if (!all_param_pass) 3192 sctp_add_asconf_response(asconf_ack, 3193 asconf_param->crr_id, err_code, 3194 asconf_param); 3195 3196 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3197 * an IP address sends an 'Out of Resource' in its response, it 3198 * MUST also fail any subsequent add or delete requests bundled 3199 * in the ASCONF. 3200 */ 3201 if (SCTP_ERROR_RSRC_LOW == err_code) 3202 goto done; 3203 3204 /* Move to the next ASCONF param. */ 3205 length = ntohs(asconf_param->param_hdr.length); 3206 asconf_param = (void *)asconf_param + length; 3207 chunk_len -= length; 3208 } 3209 3210 done: 3211 asoc->peer.addip_serial++; 3212 3213 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3214 * after freeing the reference to old asconf ack if any. 3215 */ 3216 if (asconf_ack) { 3217 sctp_chunk_hold(asconf_ack); 3218 list_add_tail(&asconf_ack->transmitted_list, 3219 &asoc->asconf_ack_list); 3220 } 3221 3222 return asconf_ack; 3223 } 3224 3225 /* Process a asconf parameter that is successfully acked. */ 3226 static void sctp_asconf_param_success(struct sctp_association *asoc, 3227 sctp_addip_param_t *asconf_param) 3228 { 3229 struct sctp_af *af; 3230 union sctp_addr addr; 3231 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3232 union sctp_addr_param *addr_param; 3233 struct sctp_transport *transport; 3234 struct sctp_sockaddr_entry *saddr; 3235 3236 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t); 3237 3238 /* We have checked the packet before, so we do not check again. */ 3239 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3240 af->from_addr_param(&addr, addr_param, htons(bp->port), 0); 3241 3242 switch (asconf_param->param_hdr.type) { 3243 case SCTP_PARAM_ADD_IP: 3244 /* This is always done in BH context with a socket lock 3245 * held, so the list can not change. 3246 */ 3247 local_bh_disable(); 3248 list_for_each_entry(saddr, &bp->address_list, list) { 3249 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3250 saddr->state = SCTP_ADDR_SRC; 3251 } 3252 local_bh_enable(); 3253 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3254 transports) { 3255 dst_release(transport->dst); 3256 transport->dst = NULL; 3257 } 3258 break; 3259 case SCTP_PARAM_DEL_IP: 3260 local_bh_disable(); 3261 sctp_del_bind_addr(bp, &addr); 3262 if (asoc->asconf_addr_del_pending != NULL && 3263 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3264 kfree(asoc->asconf_addr_del_pending); 3265 asoc->asconf_addr_del_pending = NULL; 3266 } 3267 local_bh_enable(); 3268 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3269 transports) { 3270 dst_release(transport->dst); 3271 transport->dst = NULL; 3272 } 3273 break; 3274 default: 3275 break; 3276 } 3277 } 3278 3279 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3280 * for the given asconf parameter. If there is no response for this parameter, 3281 * return the error code based on the third argument 'no_err'. 3282 * ADDIP 4.1 3283 * A7) If an error response is received for a TLV parameter, all TLVs with no 3284 * response before the failed TLV are considered successful if not reported. 3285 * All TLVs after the failed response are considered unsuccessful unless a 3286 * specific success indication is present for the parameter. 3287 */ 3288 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3289 sctp_addip_param_t *asconf_param, 3290 int no_err) 3291 { 3292 sctp_addip_param_t *asconf_ack_param; 3293 sctp_errhdr_t *err_param; 3294 int length; 3295 int asconf_ack_len; 3296 __be16 err_code; 3297 3298 if (no_err) 3299 err_code = SCTP_ERROR_NO_ERROR; 3300 else 3301 err_code = SCTP_ERROR_REQ_REFUSED; 3302 3303 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3304 sizeof(sctp_chunkhdr_t); 3305 3306 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3307 * the first asconf_ack parameter. 3308 */ 3309 length = sizeof(sctp_addiphdr_t); 3310 asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data + 3311 length); 3312 asconf_ack_len -= length; 3313 3314 while (asconf_ack_len > 0) { 3315 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3316 switch(asconf_ack_param->param_hdr.type) { 3317 case SCTP_PARAM_SUCCESS_REPORT: 3318 return SCTP_ERROR_NO_ERROR; 3319 case SCTP_PARAM_ERR_CAUSE: 3320 length = sizeof(sctp_addip_param_t); 3321 err_param = (void *)asconf_ack_param + length; 3322 asconf_ack_len -= length; 3323 if (asconf_ack_len > 0) 3324 return err_param->cause; 3325 else 3326 return SCTP_ERROR_INV_PARAM; 3327 break; 3328 default: 3329 return SCTP_ERROR_INV_PARAM; 3330 } 3331 } 3332 3333 length = ntohs(asconf_ack_param->param_hdr.length); 3334 asconf_ack_param = (void *)asconf_ack_param + length; 3335 asconf_ack_len -= length; 3336 } 3337 3338 return err_code; 3339 } 3340 3341 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3342 int sctp_process_asconf_ack(struct sctp_association *asoc, 3343 struct sctp_chunk *asconf_ack) 3344 { 3345 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3346 union sctp_addr_param *addr_param; 3347 sctp_addip_param_t *asconf_param; 3348 int length = 0; 3349 int asconf_len = asconf->skb->len; 3350 int all_param_pass = 0; 3351 int no_err = 1; 3352 int retval = 0; 3353 __be16 err_code = SCTP_ERROR_NO_ERROR; 3354 3355 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3356 * a pointer to address parameter. 3357 */ 3358 length = sizeof(sctp_addip_chunk_t); 3359 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3360 asconf_len -= length; 3361 3362 /* Skip the address parameter in the last asconf sent and store a 3363 * pointer to the first asconf parameter. 3364 */ 3365 length = ntohs(addr_param->p.length); 3366 asconf_param = (void *)addr_param + length; 3367 asconf_len -= length; 3368 3369 /* ADDIP 4.1 3370 * A8) If there is no response(s) to specific TLV parameter(s), and no 3371 * failures are indicated, then all request(s) are considered 3372 * successful. 3373 */ 3374 if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t)) 3375 all_param_pass = 1; 3376 3377 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3378 while (asconf_len > 0) { 3379 if (all_param_pass) 3380 err_code = SCTP_ERROR_NO_ERROR; 3381 else { 3382 err_code = sctp_get_asconf_response(asconf_ack, 3383 asconf_param, 3384 no_err); 3385 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3386 no_err = 0; 3387 } 3388 3389 switch (err_code) { 3390 case SCTP_ERROR_NO_ERROR: 3391 sctp_asconf_param_success(asoc, asconf_param); 3392 break; 3393 3394 case SCTP_ERROR_RSRC_LOW: 3395 retval = 1; 3396 break; 3397 3398 case SCTP_ERROR_UNKNOWN_PARAM: 3399 /* Disable sending this type of asconf parameter in 3400 * future. 3401 */ 3402 asoc->peer.addip_disabled_mask |= 3403 asconf_param->param_hdr.type; 3404 break; 3405 3406 case SCTP_ERROR_REQ_REFUSED: 3407 case SCTP_ERROR_DEL_LAST_IP: 3408 case SCTP_ERROR_DEL_SRC_IP: 3409 default: 3410 break; 3411 } 3412 3413 /* Skip the processed asconf parameter and move to the next 3414 * one. 3415 */ 3416 length = ntohs(asconf_param->param_hdr.length); 3417 asconf_param = (void *)asconf_param + length; 3418 asconf_len -= length; 3419 } 3420 3421 if (no_err && asoc->src_out_of_asoc_ok) { 3422 asoc->src_out_of_asoc_ok = 0; 3423 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3424 } 3425 3426 /* Free the cached last sent asconf chunk. */ 3427 list_del_init(&asconf->transmitted_list); 3428 sctp_chunk_free(asconf); 3429 asoc->addip_last_asconf = NULL; 3430 3431 return retval; 3432 } 3433 3434 /* Make a FWD TSN chunk. */ 3435 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3436 __u32 new_cum_tsn, size_t nstreams, 3437 struct sctp_fwdtsn_skip *skiplist) 3438 { 3439 struct sctp_chunk *retval = NULL; 3440 struct sctp_fwdtsn_hdr ftsn_hdr; 3441 struct sctp_fwdtsn_skip skip; 3442 size_t hint; 3443 int i; 3444 3445 hint = (nstreams + 1) * sizeof(__u32); 3446 3447 retval = sctp_make_chunk(asoc, SCTP_CID_FWD_TSN, 0, hint); 3448 3449 if (!retval) 3450 return NULL; 3451 3452 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3453 retval->subh.fwdtsn_hdr = 3454 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3455 3456 for (i = 0; i < nstreams; i++) { 3457 skip.stream = skiplist[i].stream; 3458 skip.ssn = skiplist[i].ssn; 3459 sctp_addto_chunk(retval, sizeof(skip), &skip); 3460 } 3461 3462 return retval; 3463 } 3464