1 /* SCTP kernel reference 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 reference 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 * The SCTP reference 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 * The SCTP reference 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 #include <linux/types.h> 54 #include <linux/kernel.h> 55 #include <linux/ip.h> 56 #include <linux/ipv6.h> 57 #include <linux/net.h> 58 #include <linux/inet.h> 59 #include <asm/scatterlist.h> 60 #include <linux/crypto.h> 61 #include <net/sock.h> 62 63 #include <linux/skbuff.h> 64 #include <linux/random.h> /* for get_random_bytes */ 65 #include <net/sctp/sctp.h> 66 #include <net/sctp/sm.h> 67 68 SCTP_STATIC 69 struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc, 70 __u8 type, __u8 flags, int paylen); 71 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, 72 const struct sctp_association *asoc, 73 const struct sctp_chunk *init_chunk, 74 int *cookie_len, 75 const __u8 *raw_addrs, int addrs_len); 76 static int sctp_process_param(struct sctp_association *asoc, 77 union sctp_params param, 78 const union sctp_addr *peer_addr, 79 gfp_t gfp); 80 81 /* What was the inbound interface for this chunk? */ 82 int sctp_chunk_iif(const struct sctp_chunk *chunk) 83 { 84 struct sctp_af *af; 85 int iif = 0; 86 87 af = sctp_get_af_specific(ipver2af(ip_hdr(chunk->skb)->version)); 88 if (af) 89 iif = af->skb_iif(chunk->skb); 90 91 return iif; 92 } 93 94 /* RFC 2960 3.3.2 Initiation (INIT) (1) 95 * 96 * Note 2: The ECN capable field is reserved for future use of 97 * Explicit Congestion Notification. 98 */ 99 static const struct sctp_paramhdr ecap_param = { 100 SCTP_PARAM_ECN_CAPABLE, 101 __constant_htons(sizeof(struct sctp_paramhdr)), 102 }; 103 static const struct sctp_paramhdr prsctp_param = { 104 SCTP_PARAM_FWD_TSN_SUPPORT, 105 __constant_htons(sizeof(struct sctp_paramhdr)), 106 }; 107 108 /* A helper to initialize to initialize an op error inside a 109 * provided chunk, as most cause codes will be embedded inside an 110 * abort chunk. 111 */ 112 void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, 113 size_t paylen) 114 { 115 sctp_errhdr_t err; 116 __u16 len; 117 118 /* Cause code constants are now defined in network order. */ 119 err.cause = cause_code; 120 len = sizeof(sctp_errhdr_t) + paylen; 121 err.length = htons(len); 122 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err); 123 } 124 125 /* 3.3.2 Initiation (INIT) (1) 126 * 127 * This chunk is used to initiate a SCTP association between two 128 * endpoints. The format of the INIT chunk is shown below: 129 * 130 * 0 1 2 3 131 * 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 1 132 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 133 * | Type = 1 | Chunk Flags | Chunk Length | 134 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 135 * | Initiate Tag | 136 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 137 * | Advertised Receiver Window Credit (a_rwnd) | 138 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 139 * | Number of Outbound Streams | Number of Inbound Streams | 140 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 141 * | Initial TSN | 142 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 143 * \ \ 144 * / Optional/Variable-Length Parameters / 145 * \ \ 146 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 147 * 148 * 149 * The INIT chunk contains the following parameters. Unless otherwise 150 * noted, each parameter MUST only be included once in the INIT chunk. 151 * 152 * Fixed Parameters Status 153 * ---------------------------------------------- 154 * Initiate Tag Mandatory 155 * Advertised Receiver Window Credit Mandatory 156 * Number of Outbound Streams Mandatory 157 * Number of Inbound Streams Mandatory 158 * Initial TSN Mandatory 159 * 160 * Variable Parameters Status Type Value 161 * ------------------------------------------------------------- 162 * IPv4 Address (Note 1) Optional 5 163 * IPv6 Address (Note 1) Optional 6 164 * Cookie Preservative Optional 9 165 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000) 166 * Host Name Address (Note 3) Optional 11 167 * Supported Address Types (Note 4) Optional 12 168 */ 169 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc, 170 const struct sctp_bind_addr *bp, 171 gfp_t gfp, int vparam_len) 172 { 173 sctp_inithdr_t init; 174 union sctp_params addrs; 175 size_t chunksize; 176 struct sctp_chunk *retval = NULL; 177 int num_types, addrs_len = 0; 178 struct sctp_sock *sp; 179 sctp_supported_addrs_param_t sat; 180 __be16 types[2]; 181 sctp_adaptation_ind_param_t aiparam; 182 183 /* RFC 2960 3.3.2 Initiation (INIT) (1) 184 * 185 * Note 1: The INIT chunks can contain multiple addresses that 186 * can be IPv4 and/or IPv6 in any combination. 187 */ 188 retval = NULL; 189 190 /* Convert the provided bind address list to raw format. */ 191 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp); 192 193 init.init_tag = htonl(asoc->c.my_vtag); 194 init.a_rwnd = htonl(asoc->rwnd); 195 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 196 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 197 init.initial_tsn = htonl(asoc->c.initial_tsn); 198 199 /* How many address types are needed? */ 200 sp = sctp_sk(asoc->base.sk); 201 num_types = sp->pf->supported_addrs(sp, types); 202 203 chunksize = sizeof(init) + addrs_len + SCTP_SAT_LEN(num_types); 204 chunksize += sizeof(ecap_param); 205 if (sctp_prsctp_enable) 206 chunksize += sizeof(prsctp_param); 207 chunksize += sizeof(aiparam); 208 chunksize += vparam_len; 209 210 /* RFC 2960 3.3.2 Initiation (INIT) (1) 211 * 212 * Note 3: An INIT chunk MUST NOT contain more than one Host 213 * Name address parameter. Moreover, the sender of the INIT 214 * MUST NOT combine any other address types with the Host Name 215 * address in the INIT. The receiver of INIT MUST ignore any 216 * other address types if the Host Name address parameter is 217 * present in the received INIT chunk. 218 * 219 * PLEASE DO NOT FIXME [This version does not support Host Name.] 220 */ 221 222 retval = sctp_make_chunk(asoc, SCTP_CID_INIT, 0, chunksize); 223 if (!retval) 224 goto nodata; 225 226 retval->subh.init_hdr = 227 sctp_addto_chunk(retval, sizeof(init), &init); 228 retval->param_hdr.v = 229 sctp_addto_chunk(retval, addrs_len, addrs.v); 230 231 /* RFC 2960 3.3.2 Initiation (INIT) (1) 232 * 233 * Note 4: This parameter, when present, specifies all the 234 * address types the sending endpoint can support. The absence 235 * of this parameter indicates that the sending endpoint can 236 * support any address type. 237 */ 238 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES; 239 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types)); 240 sctp_addto_chunk(retval, sizeof(sat), &sat); 241 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types); 242 243 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 244 if (sctp_prsctp_enable) 245 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 246 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 247 aiparam.param_hdr.length = htons(sizeof(aiparam)); 248 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 249 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 250 nodata: 251 kfree(addrs.v); 252 return retval; 253 } 254 255 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, 256 const struct sctp_chunk *chunk, 257 gfp_t gfp, int unkparam_len) 258 { 259 sctp_inithdr_t initack; 260 struct sctp_chunk *retval; 261 union sctp_params addrs; 262 int addrs_len; 263 sctp_cookie_param_t *cookie; 264 int cookie_len; 265 size_t chunksize; 266 sctp_adaptation_ind_param_t aiparam; 267 268 retval = NULL; 269 270 /* Note: there may be no addresses to embed. */ 271 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp); 272 273 initack.init_tag = htonl(asoc->c.my_vtag); 274 initack.a_rwnd = htonl(asoc->rwnd); 275 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 276 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 277 initack.initial_tsn = htonl(asoc->c.initial_tsn); 278 279 /* FIXME: We really ought to build the cookie right 280 * into the packet instead of allocating more fresh memory. 281 */ 282 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len, 283 addrs.v, addrs_len); 284 if (!cookie) 285 goto nomem_cookie; 286 287 /* Calculate the total size of allocation, include the reserved 288 * space for reporting unknown parameters if it is specified. 289 */ 290 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len; 291 292 /* Tell peer that we'll do ECN only if peer advertised such cap. */ 293 if (asoc->peer.ecn_capable) 294 chunksize += sizeof(ecap_param); 295 296 /* Tell peer that we'll do PR-SCTP only if peer advertised. */ 297 if (asoc->peer.prsctp_capable) 298 chunksize += sizeof(prsctp_param); 299 300 chunksize += sizeof(aiparam); 301 302 /* Now allocate and fill out the chunk. */ 303 retval = sctp_make_chunk(asoc, SCTP_CID_INIT_ACK, 0, chunksize); 304 if (!retval) 305 goto nomem_chunk; 306 307 /* Per the advice in RFC 2960 6.4, send this reply to 308 * the source of the INIT packet. 309 */ 310 retval->transport = chunk->transport; 311 retval->subh.init_hdr = 312 sctp_addto_chunk(retval, sizeof(initack), &initack); 313 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); 314 sctp_addto_chunk(retval, cookie_len, cookie); 315 if (asoc->peer.ecn_capable) 316 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 317 if (asoc->peer.prsctp_capable) 318 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 319 320 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 321 aiparam.param_hdr.length = htons(sizeof(aiparam)); 322 aiparam.adaptation_ind = htonl(sctp_sk(asoc->base.sk)->adaptation_ind); 323 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 324 325 /* We need to remove the const qualifier at this point. */ 326 retval->asoc = (struct sctp_association *) asoc; 327 328 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 329 * 330 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 331 * HEARTBEAT ACK, * etc.) to the same destination transport 332 * address from which it received the DATA or control chunk 333 * to which it is replying. 334 * 335 * [INIT ACK back to where the INIT came from.] 336 */ 337 if (chunk) 338 retval->transport = chunk->transport; 339 340 nomem_chunk: 341 kfree(cookie); 342 nomem_cookie: 343 kfree(addrs.v); 344 return retval; 345 } 346 347 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10): 348 * 349 * This chunk is used only during the initialization of an association. 350 * It is sent by the initiator of an association to its peer to complete 351 * the initialization process. This chunk MUST precede any DATA chunk 352 * sent within the association, but MAY be bundled with one or more DATA 353 * chunks in the same packet. 354 * 355 * 0 1 2 3 356 * 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 1 357 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 358 * | Type = 10 |Chunk Flags | Length | 359 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 360 * / Cookie / 361 * \ \ 362 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 363 * 364 * Chunk Flags: 8 bit 365 * 366 * Set to zero on transmit and ignored on receipt. 367 * 368 * Length: 16 bits (unsigned integer) 369 * 370 * Set to the size of the chunk in bytes, including the 4 bytes of 371 * the chunk header and the size of the Cookie. 372 * 373 * Cookie: variable size 374 * 375 * This field must contain the exact cookie received in the 376 * State Cookie parameter from the previous INIT ACK. 377 * 378 * An implementation SHOULD make the cookie as small as possible 379 * to insure interoperability. 380 */ 381 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, 382 const struct sctp_chunk *chunk) 383 { 384 struct sctp_chunk *retval; 385 void *cookie; 386 int cookie_len; 387 388 cookie = asoc->peer.cookie; 389 cookie_len = asoc->peer.cookie_len; 390 391 /* Build a cookie echo chunk. */ 392 retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ECHO, 0, cookie_len); 393 if (!retval) 394 goto nodata; 395 retval->subh.cookie_hdr = 396 sctp_addto_chunk(retval, cookie_len, cookie); 397 398 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 399 * 400 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 401 * HEARTBEAT ACK, * etc.) to the same destination transport 402 * address from which it * received the DATA or control chunk 403 * to which it is replying. 404 * 405 * [COOKIE ECHO back to where the INIT ACK came from.] 406 */ 407 if (chunk) 408 retval->transport = chunk->transport; 409 410 nodata: 411 return retval; 412 } 413 414 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11): 415 * 416 * This chunk is used only during the initialization of an 417 * association. It is used to acknowledge the receipt of a COOKIE 418 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent 419 * within the association, but MAY be bundled with one or more DATA 420 * chunks or SACK chunk in the same SCTP packet. 421 * 422 * 0 1 2 3 423 * 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 1 424 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 425 * | Type = 11 |Chunk Flags | Length = 4 | 426 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 427 * 428 * Chunk Flags: 8 bits 429 * 430 * Set to zero on transmit and ignored on receipt. 431 */ 432 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, 433 const struct sctp_chunk *chunk) 434 { 435 struct sctp_chunk *retval; 436 437 retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ACK, 0, 0); 438 439 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 440 * 441 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 442 * HEARTBEAT ACK, * etc.) to the same destination transport 443 * address from which it * received the DATA or control chunk 444 * to which it is replying. 445 * 446 * [COOKIE ACK back to where the COOKIE ECHO came from.] 447 */ 448 if (retval && chunk) 449 retval->transport = chunk->transport; 450 451 return retval; 452 } 453 454 /* 455 * Appendix A: Explicit Congestion Notification: 456 * CWR: 457 * 458 * RFC 2481 details a specific bit for a sender to send in the header of 459 * its next outbound TCP segment to indicate to its peer that it has 460 * reduced its congestion window. This is termed the CWR bit. For 461 * SCTP the same indication is made by including the CWR chunk. 462 * This chunk contains one data element, i.e. the TSN number that 463 * was sent in the ECNE chunk. This element represents the lowest 464 * TSN number in the datagram that was originally marked with the 465 * CE bit. 466 * 467 * 0 1 2 3 468 * 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 1 469 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 470 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 | 471 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 472 * | Lowest TSN Number | 473 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 474 * 475 * Note: The CWR is considered a Control chunk. 476 */ 477 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, 478 const __u32 lowest_tsn, 479 const struct sctp_chunk *chunk) 480 { 481 struct sctp_chunk *retval; 482 sctp_cwrhdr_t cwr; 483 484 cwr.lowest_tsn = htonl(lowest_tsn); 485 retval = sctp_make_chunk(asoc, SCTP_CID_ECN_CWR, 0, 486 sizeof(sctp_cwrhdr_t)); 487 488 if (!retval) 489 goto nodata; 490 491 retval->subh.ecn_cwr_hdr = 492 sctp_addto_chunk(retval, sizeof(cwr), &cwr); 493 494 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 495 * 496 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 497 * HEARTBEAT ACK, * etc.) to the same destination transport 498 * address from which it * received the DATA or control chunk 499 * to which it is replying. 500 * 501 * [Report a reduced congestion window back to where the ECNE 502 * came from.] 503 */ 504 if (chunk) 505 retval->transport = chunk->transport; 506 507 nodata: 508 return retval; 509 } 510 511 /* Make an ECNE chunk. This is a congestion experienced report. */ 512 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, 513 const __u32 lowest_tsn) 514 { 515 struct sctp_chunk *retval; 516 sctp_ecnehdr_t ecne; 517 518 ecne.lowest_tsn = htonl(lowest_tsn); 519 retval = sctp_make_chunk(asoc, SCTP_CID_ECN_ECNE, 0, 520 sizeof(sctp_ecnehdr_t)); 521 if (!retval) 522 goto nodata; 523 retval->subh.ecne_hdr = 524 sctp_addto_chunk(retval, sizeof(ecne), &ecne); 525 526 nodata: 527 return retval; 528 } 529 530 /* Make a DATA chunk for the given association from the provided 531 * parameters. However, do not populate the data payload. 532 */ 533 struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc, 534 const struct sctp_sndrcvinfo *sinfo, 535 int data_len, __u8 flags, __u16 ssn) 536 { 537 struct sctp_chunk *retval; 538 struct sctp_datahdr dp; 539 int chunk_len; 540 541 /* We assign the TSN as LATE as possible, not here when 542 * creating the chunk. 543 */ 544 dp.tsn = 0; 545 dp.stream = htons(sinfo->sinfo_stream); 546 dp.ppid = sinfo->sinfo_ppid; 547 548 /* Set the flags for an unordered send. */ 549 if (sinfo->sinfo_flags & SCTP_UNORDERED) { 550 flags |= SCTP_DATA_UNORDERED; 551 dp.ssn = 0; 552 } else 553 dp.ssn = htons(ssn); 554 555 chunk_len = sizeof(dp) + data_len; 556 retval = sctp_make_chunk(asoc, SCTP_CID_DATA, flags, chunk_len); 557 if (!retval) 558 goto nodata; 559 560 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp); 561 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo)); 562 563 nodata: 564 return retval; 565 } 566 567 /* Create a selective ackowledgement (SACK) for the given 568 * association. This reports on which TSN's we've seen to date, 569 * including duplicates and gaps. 570 */ 571 struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc) 572 { 573 struct sctp_chunk *retval; 574 struct sctp_sackhdr sack; 575 int len; 576 __u32 ctsn; 577 __u16 num_gabs, num_dup_tsns; 578 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; 579 580 ctsn = sctp_tsnmap_get_ctsn(map); 581 SCTP_DEBUG_PRINTK("sackCTSNAck sent: 0x%x.\n", ctsn); 582 583 /* How much room is needed in the chunk? */ 584 num_gabs = sctp_tsnmap_num_gabs(map); 585 num_dup_tsns = sctp_tsnmap_num_dups(map); 586 587 /* Initialize the SACK header. */ 588 sack.cum_tsn_ack = htonl(ctsn); 589 sack.a_rwnd = htonl(asoc->a_rwnd); 590 sack.num_gap_ack_blocks = htons(num_gabs); 591 sack.num_dup_tsns = htons(num_dup_tsns); 592 593 len = sizeof(sack) 594 + sizeof(struct sctp_gap_ack_block) * num_gabs 595 + sizeof(__u32) * num_dup_tsns; 596 597 /* Create the chunk. */ 598 retval = sctp_make_chunk(asoc, SCTP_CID_SACK, 0, len); 599 if (!retval) 600 goto nodata; 601 602 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 603 * 604 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 605 * HEARTBEAT ACK, etc.) to the same destination transport 606 * address from which it received the DATA or control chunk to 607 * which it is replying. This rule should also be followed if 608 * the endpoint is bundling DATA chunks together with the 609 * reply chunk. 610 * 611 * However, when acknowledging multiple DATA chunks received 612 * in packets from different source addresses in a single 613 * SACK, the SACK chunk may be transmitted to one of the 614 * destination transport addresses from which the DATA or 615 * control chunks being acknowledged were received. 616 * 617 * [BUG: We do not implement the following paragraph. 618 * Perhaps we should remember the last transport we used for a 619 * SACK and avoid that (if possible) if we have seen any 620 * duplicates. --piggy] 621 * 622 * When a receiver of a duplicate DATA chunk sends a SACK to a 623 * multi- homed endpoint it MAY be beneficial to vary the 624 * destination address and not use the source address of the 625 * DATA chunk. The reason being that receiving a duplicate 626 * from a multi-homed endpoint might indicate that the return 627 * path (as specified in the source address of the DATA chunk) 628 * for the SACK is broken. 629 * 630 * [Send to the address from which we last received a DATA chunk.] 631 */ 632 retval->transport = asoc->peer.last_data_from; 633 634 retval->subh.sack_hdr = 635 sctp_addto_chunk(retval, sizeof(sack), &sack); 636 637 /* Add the gap ack block information. */ 638 if (num_gabs) 639 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, 640 sctp_tsnmap_get_gabs(map)); 641 642 /* Add the duplicate TSN information. */ 643 if (num_dup_tsns) 644 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, 645 sctp_tsnmap_get_dups(map)); 646 647 nodata: 648 return retval; 649 } 650 651 /* Make a SHUTDOWN chunk. */ 652 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 653 const struct sctp_chunk *chunk) 654 { 655 struct sctp_chunk *retval; 656 sctp_shutdownhdr_t shut; 657 __u32 ctsn; 658 659 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 660 shut.cum_tsn_ack = htonl(ctsn); 661 662 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN, 0, 663 sizeof(sctp_shutdownhdr_t)); 664 if (!retval) 665 goto nodata; 666 667 retval->subh.shutdown_hdr = 668 sctp_addto_chunk(retval, sizeof(shut), &shut); 669 670 if (chunk) 671 retval->transport = chunk->transport; 672 nodata: 673 return retval; 674 } 675 676 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 677 const struct sctp_chunk *chunk) 678 { 679 struct sctp_chunk *retval; 680 681 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0); 682 683 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 684 * 685 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 686 * HEARTBEAT ACK, * etc.) to the same destination transport 687 * address from which it * received the DATA or control chunk 688 * to which it is replying. 689 * 690 * [ACK back to where the SHUTDOWN came from.] 691 */ 692 if (retval && chunk) 693 retval->transport = chunk->transport; 694 695 return retval; 696 } 697 698 struct sctp_chunk *sctp_make_shutdown_complete( 699 const struct sctp_association *asoc, 700 const struct sctp_chunk *chunk) 701 { 702 struct sctp_chunk *retval; 703 __u8 flags = 0; 704 705 /* Set the T-bit if we have no association (vtag will be 706 * reflected) 707 */ 708 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; 709 710 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0); 711 712 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 713 * 714 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 715 * HEARTBEAT ACK, * etc.) to the same destination transport 716 * address from which it * received the DATA or control chunk 717 * to which it is replying. 718 * 719 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK 720 * came from.] 721 */ 722 if (retval && chunk) 723 retval->transport = chunk->transport; 724 725 return retval; 726 } 727 728 /* Create an ABORT. Note that we set the T bit if we have no 729 * association, except when responding to an INIT (sctpimpguide 2.41). 730 */ 731 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 732 const struct sctp_chunk *chunk, 733 const size_t hint) 734 { 735 struct sctp_chunk *retval; 736 __u8 flags = 0; 737 738 /* Set the T-bit if we have no association and 'chunk' is not 739 * an INIT (vtag will be reflected). 740 */ 741 if (!asoc) { 742 if (chunk && chunk->chunk_hdr && 743 chunk->chunk_hdr->type == SCTP_CID_INIT) 744 flags = 0; 745 else 746 flags = SCTP_CHUNK_FLAG_T; 747 } 748 749 retval = sctp_make_chunk(asoc, SCTP_CID_ABORT, flags, hint); 750 751 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 752 * 753 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 754 * HEARTBEAT ACK, * etc.) to the same destination transport 755 * address from which it * received the DATA or control chunk 756 * to which it is replying. 757 * 758 * [ABORT back to where the offender came from.] 759 */ 760 if (retval && chunk) 761 retval->transport = chunk->transport; 762 763 return retval; 764 } 765 766 /* Helper to create ABORT with a NO_USER_DATA error. */ 767 struct sctp_chunk *sctp_make_abort_no_data( 768 const struct sctp_association *asoc, 769 const struct sctp_chunk *chunk, __u32 tsn) 770 { 771 struct sctp_chunk *retval; 772 __be32 payload; 773 774 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) 775 + sizeof(tsn)); 776 777 if (!retval) 778 goto no_mem; 779 780 /* Put the tsn back into network byte order. */ 781 payload = htonl(tsn); 782 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload)); 783 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload); 784 785 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 786 * 787 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 788 * HEARTBEAT ACK, * etc.) to the same destination transport 789 * address from which it * received the DATA or control chunk 790 * to which it is replying. 791 * 792 * [ABORT back to where the offender came from.] 793 */ 794 if (chunk) 795 retval->transport = chunk->transport; 796 797 no_mem: 798 return retval; 799 } 800 801 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ 802 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 803 const struct msghdr *msg, 804 size_t paylen) 805 { 806 struct sctp_chunk *retval; 807 void *payload = NULL; 808 int err; 809 810 retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen); 811 if (!retval) 812 goto err_chunk; 813 814 if (paylen) { 815 /* Put the msg_iov together into payload. */ 816 payload = kmalloc(paylen, GFP_KERNEL); 817 if (!payload) 818 goto err_payload; 819 820 err = memcpy_fromiovec(payload, msg->msg_iov, paylen); 821 if (err < 0) 822 goto err_copy; 823 } 824 825 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); 826 sctp_addto_chunk(retval, paylen, payload); 827 828 if (paylen) 829 kfree(payload); 830 831 return retval; 832 833 err_copy: 834 kfree(payload); 835 err_payload: 836 sctp_chunk_free(retval); 837 retval = NULL; 838 err_chunk: 839 return retval; 840 } 841 842 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ 843 struct sctp_chunk *sctp_make_abort_violation( 844 const struct sctp_association *asoc, 845 const struct sctp_chunk *chunk, 846 const __u8 *payload, 847 const size_t paylen) 848 { 849 struct sctp_chunk *retval; 850 struct sctp_paramhdr phdr; 851 852 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen 853 + sizeof(sctp_paramhdr_t)); 854 if (!retval) 855 goto end; 856 857 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen 858 + sizeof(sctp_paramhdr_t)); 859 860 phdr.type = htons(chunk->chunk_hdr->type); 861 phdr.length = chunk->chunk_hdr->length; 862 sctp_addto_chunk(retval, paylen, payload); 863 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr); 864 865 end: 866 return retval; 867 } 868 869 /* Make a HEARTBEAT chunk. */ 870 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 871 const struct sctp_transport *transport, 872 const void *payload, const size_t paylen) 873 { 874 struct sctp_chunk *retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT, 875 0, paylen); 876 877 if (!retval) 878 goto nodata; 879 880 /* Cast away the 'const', as this is just telling the chunk 881 * what transport it belongs to. 882 */ 883 retval->transport = (struct sctp_transport *) transport; 884 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 885 886 nodata: 887 return retval; 888 } 889 890 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 891 const struct sctp_chunk *chunk, 892 const void *payload, const size_t paylen) 893 { 894 struct sctp_chunk *retval; 895 896 retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen); 897 if (!retval) 898 goto nodata; 899 900 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 901 902 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 903 * 904 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 905 * HEARTBEAT ACK, * etc.) to the same destination transport 906 * address from which it * received the DATA or control chunk 907 * to which it is replying. 908 * 909 * [HBACK back to where the HEARTBEAT came from.] 910 */ 911 if (chunk) 912 retval->transport = chunk->transport; 913 914 nodata: 915 return retval; 916 } 917 918 /* Create an Operation Error chunk with the specified space reserved. 919 * This routine can be used for containing multiple causes in the chunk. 920 */ 921 static struct sctp_chunk *sctp_make_op_error_space( 922 const struct sctp_association *asoc, 923 const struct sctp_chunk *chunk, 924 size_t size) 925 { 926 struct sctp_chunk *retval; 927 928 retval = sctp_make_chunk(asoc, SCTP_CID_ERROR, 0, 929 sizeof(sctp_errhdr_t) + size); 930 if (!retval) 931 goto nodata; 932 933 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 934 * 935 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 936 * HEARTBEAT ACK, etc.) to the same destination transport 937 * address from which it received the DATA or control chunk 938 * to which it is replying. 939 * 940 */ 941 if (chunk) 942 retval->transport = chunk->transport; 943 944 nodata: 945 return retval; 946 } 947 948 /* Create an Operation Error chunk. */ 949 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 950 const struct sctp_chunk *chunk, 951 __be16 cause_code, const void *payload, 952 size_t paylen) 953 { 954 struct sctp_chunk *retval; 955 956 retval = sctp_make_op_error_space(asoc, chunk, paylen); 957 if (!retval) 958 goto nodata; 959 960 sctp_init_cause(retval, cause_code, paylen); 961 sctp_addto_chunk(retval, paylen, payload); 962 963 nodata: 964 return retval; 965 } 966 967 /******************************************************************** 968 * 2nd Level Abstractions 969 ********************************************************************/ 970 971 /* Turn an skb into a chunk. 972 * FIXME: Eventually move the structure directly inside the skb->cb[]. 973 */ 974 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 975 const struct sctp_association *asoc, 976 struct sock *sk) 977 { 978 struct sctp_chunk *retval; 979 980 retval = kmem_cache_zalloc(sctp_chunk_cachep, GFP_ATOMIC); 981 982 if (!retval) 983 goto nodata; 984 985 if (!sk) { 986 SCTP_DEBUG_PRINTK("chunkifying skb %p w/o an sk\n", skb); 987 } 988 989 INIT_LIST_HEAD(&retval->list); 990 retval->skb = skb; 991 retval->asoc = (struct sctp_association *)asoc; 992 retval->resent = 0; 993 retval->has_tsn = 0; 994 retval->has_ssn = 0; 995 retval->rtt_in_progress = 0; 996 retval->sent_at = 0; 997 retval->singleton = 1; 998 retval->end_of_packet = 0; 999 retval->ecn_ce_done = 0; 1000 retval->pdiscard = 0; 1001 1002 /* sctpimpguide-05.txt Section 2.8.2 1003 * M1) Each time a new DATA chunk is transmitted 1004 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1005 * 'TSN.Missing.Report' count will be used to determine missing chunks 1006 * and when to fast retransmit. 1007 */ 1008 retval->tsn_missing_report = 0; 1009 retval->tsn_gap_acked = 0; 1010 retval->fast_retransmit = 0; 1011 1012 /* If this is a fragmented message, track all fragments 1013 * of the message (for SEND_FAILED). 1014 */ 1015 retval->msg = NULL; 1016 1017 /* Polish the bead hole. */ 1018 INIT_LIST_HEAD(&retval->transmitted_list); 1019 INIT_LIST_HEAD(&retval->frag_list); 1020 SCTP_DBG_OBJCNT_INC(chunk); 1021 atomic_set(&retval->refcnt, 1); 1022 1023 nodata: 1024 return retval; 1025 } 1026 1027 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1028 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1029 union sctp_addr *dest) 1030 { 1031 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1032 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1033 } 1034 1035 /* Extract the source address from a chunk. */ 1036 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1037 { 1038 /* If we have a known transport, use that. */ 1039 if (chunk->transport) { 1040 return &chunk->transport->ipaddr; 1041 } else { 1042 /* Otherwise, extract it from the IP header. */ 1043 return &chunk->source; 1044 } 1045 } 1046 1047 /* Create a new chunk, setting the type and flags headers from the 1048 * arguments, reserving enough space for a 'paylen' byte payload. 1049 */ 1050 SCTP_STATIC 1051 struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc, 1052 __u8 type, __u8 flags, int paylen) 1053 { 1054 struct sctp_chunk *retval; 1055 sctp_chunkhdr_t *chunk_hdr; 1056 struct sk_buff *skb; 1057 struct sock *sk; 1058 1059 /* No need to allocate LL here, as this is only a chunk. */ 1060 skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen), 1061 GFP_ATOMIC); 1062 if (!skb) 1063 goto nodata; 1064 1065 /* Make room for the chunk header. */ 1066 chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t)); 1067 chunk_hdr->type = type; 1068 chunk_hdr->flags = flags; 1069 chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t)); 1070 1071 sk = asoc ? asoc->base.sk : NULL; 1072 retval = sctp_chunkify(skb, asoc, sk); 1073 if (!retval) { 1074 kfree_skb(skb); 1075 goto nodata; 1076 } 1077 1078 retval->chunk_hdr = chunk_hdr; 1079 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr); 1080 1081 /* Set the skb to the belonging sock for accounting. */ 1082 skb->sk = sk; 1083 1084 return retval; 1085 nodata: 1086 return NULL; 1087 } 1088 1089 1090 /* Release the memory occupied by a chunk. */ 1091 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1092 { 1093 /* Free the chunk skb data and the SCTP_chunk stub itself. */ 1094 dev_kfree_skb(chunk->skb); 1095 1096 SCTP_DBG_OBJCNT_DEC(chunk); 1097 kmem_cache_free(sctp_chunk_cachep, chunk); 1098 } 1099 1100 /* Possibly, free the chunk. */ 1101 void sctp_chunk_free(struct sctp_chunk *chunk) 1102 { 1103 BUG_ON(!list_empty(&chunk->list)); 1104 list_del_init(&chunk->transmitted_list); 1105 1106 /* Release our reference on the message tracker. */ 1107 if (chunk->msg) 1108 sctp_datamsg_put(chunk->msg); 1109 1110 sctp_chunk_put(chunk); 1111 } 1112 1113 /* Grab a reference to the chunk. */ 1114 void sctp_chunk_hold(struct sctp_chunk *ch) 1115 { 1116 atomic_inc(&ch->refcnt); 1117 } 1118 1119 /* Release a reference to the chunk. */ 1120 void sctp_chunk_put(struct sctp_chunk *ch) 1121 { 1122 if (atomic_dec_and_test(&ch->refcnt)) 1123 sctp_chunk_destroy(ch); 1124 } 1125 1126 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1127 * enough. 1128 */ 1129 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1130 { 1131 void *target; 1132 void *padding; 1133 int chunklen = ntohs(chunk->chunk_hdr->length); 1134 int padlen = WORD_ROUND(chunklen) - chunklen; 1135 1136 padding = skb_put(chunk->skb, padlen); 1137 target = skb_put(chunk->skb, len); 1138 1139 memset(padding, 0, padlen); 1140 memcpy(target, data, len); 1141 1142 /* Adjust the chunk length field. */ 1143 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1144 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1145 1146 return target; 1147 } 1148 1149 /* Append bytes to the end of a parameter. Will panic if chunk is not big 1150 * enough. 1151 */ 1152 void *sctp_addto_param(struct sctp_chunk *chunk, int len, const void *data) 1153 { 1154 void *target; 1155 int chunklen = ntohs(chunk->chunk_hdr->length); 1156 1157 target = skb_put(chunk->skb, len); 1158 1159 memcpy(target, data, len); 1160 1161 /* Adjust the chunk length field. */ 1162 chunk->chunk_hdr->length = htons(chunklen + len); 1163 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1164 1165 return target; 1166 } 1167 1168 /* Append bytes from user space to the end of a chunk. Will panic if 1169 * chunk is not big enough. 1170 * Returns a kernel err value. 1171 */ 1172 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len, 1173 struct iovec *data) 1174 { 1175 __u8 *target; 1176 int err = 0; 1177 1178 /* Make room in chunk for data. */ 1179 target = skb_put(chunk->skb, len); 1180 1181 /* Copy data (whole iovec) into chunk */ 1182 if ((err = memcpy_fromiovecend(target, data, off, len))) 1183 goto out; 1184 1185 /* Adjust the chunk length field. */ 1186 chunk->chunk_hdr->length = 1187 htons(ntohs(chunk->chunk_hdr->length) + len); 1188 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1189 1190 out: 1191 return err; 1192 } 1193 1194 /* Helper function to assign a TSN if needed. This assumes that both 1195 * the data_hdr and association have already been assigned. 1196 */ 1197 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1198 { 1199 struct sctp_datamsg *msg; 1200 struct sctp_chunk *lchunk; 1201 struct sctp_stream *stream; 1202 __u16 ssn; 1203 __u16 sid; 1204 1205 if (chunk->has_ssn) 1206 return; 1207 1208 /* All fragments will be on the same stream */ 1209 sid = ntohs(chunk->subh.data_hdr->stream); 1210 stream = &chunk->asoc->ssnmap->out; 1211 1212 /* Now assign the sequence number to the entire message. 1213 * All fragments must have the same stream sequence number. 1214 */ 1215 msg = chunk->msg; 1216 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1217 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1218 ssn = 0; 1219 } else { 1220 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1221 ssn = sctp_ssn_next(stream, sid); 1222 else 1223 ssn = sctp_ssn_peek(stream, sid); 1224 } 1225 1226 lchunk->subh.data_hdr->ssn = htons(ssn); 1227 lchunk->has_ssn = 1; 1228 } 1229 } 1230 1231 /* Helper function to assign a TSN if needed. This assumes that both 1232 * the data_hdr and association have already been assigned. 1233 */ 1234 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1235 { 1236 if (!chunk->has_tsn) { 1237 /* This is the last possible instant to 1238 * assign a TSN. 1239 */ 1240 chunk->subh.data_hdr->tsn = 1241 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1242 chunk->has_tsn = 1; 1243 } 1244 } 1245 1246 /* Create a CLOSED association to use with an incoming packet. */ 1247 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1248 struct sctp_chunk *chunk, 1249 gfp_t gfp) 1250 { 1251 struct sctp_association *asoc; 1252 struct sk_buff *skb; 1253 sctp_scope_t scope; 1254 struct sctp_af *af; 1255 1256 /* Create the bare association. */ 1257 scope = sctp_scope(sctp_source(chunk)); 1258 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1259 if (!asoc) 1260 goto nodata; 1261 asoc->temp = 1; 1262 skb = chunk->skb; 1263 /* Create an entry for the source address of the packet. */ 1264 af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version)); 1265 if (unlikely(!af)) 1266 goto fail; 1267 af->from_skb(&asoc->c.peer_addr, skb, 1); 1268 nodata: 1269 return asoc; 1270 1271 fail: 1272 sctp_association_free(asoc); 1273 return NULL; 1274 } 1275 1276 /* Build a cookie representing asoc. 1277 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1278 */ 1279 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, 1280 const struct sctp_association *asoc, 1281 const struct sctp_chunk *init_chunk, 1282 int *cookie_len, 1283 const __u8 *raw_addrs, int addrs_len) 1284 { 1285 sctp_cookie_param_t *retval; 1286 struct sctp_signed_cookie *cookie; 1287 struct scatterlist sg; 1288 int headersize, bodysize; 1289 unsigned int keylen; 1290 char *key; 1291 1292 /* Header size is static data prior to the actual cookie, including 1293 * any padding. 1294 */ 1295 headersize = sizeof(sctp_paramhdr_t) + 1296 (sizeof(struct sctp_signed_cookie) - 1297 sizeof(struct sctp_cookie)); 1298 bodysize = sizeof(struct sctp_cookie) 1299 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1300 1301 /* Pad out the cookie to a multiple to make the signature 1302 * functions simpler to write. 1303 */ 1304 if (bodysize % SCTP_COOKIE_MULTIPLE) 1305 bodysize += SCTP_COOKIE_MULTIPLE 1306 - (bodysize % SCTP_COOKIE_MULTIPLE); 1307 *cookie_len = headersize + bodysize; 1308 1309 /* Clear this memory since we are sending this data structure 1310 * out on the network. 1311 */ 1312 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1313 if (!retval) 1314 goto nodata; 1315 1316 cookie = (struct sctp_signed_cookie *) retval->body; 1317 1318 /* Set up the parameter header. */ 1319 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1320 retval->p.length = htons(*cookie_len); 1321 1322 /* Copy the cookie part of the association itself. */ 1323 cookie->c = asoc->c; 1324 /* Save the raw address list length in the cookie. */ 1325 cookie->c.raw_addr_list_len = addrs_len; 1326 1327 /* Remember PR-SCTP capability. */ 1328 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1329 1330 /* Save adaptation indication in the cookie. */ 1331 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1332 1333 /* Set an expiration time for the cookie. */ 1334 do_gettimeofday(&cookie->c.expiration); 1335 TIMEVAL_ADD(asoc->cookie_life, cookie->c.expiration); 1336 1337 /* Copy the peer's init packet. */ 1338 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr, 1339 ntohs(init_chunk->chunk_hdr->length)); 1340 1341 /* Copy the raw local address list of the association. */ 1342 memcpy((__u8 *)&cookie->c.peer_init[0] + 1343 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1344 1345 if (sctp_sk(ep->base.sk)->hmac) { 1346 struct hash_desc desc; 1347 1348 /* Sign the message. */ 1349 sg.page = virt_to_page(&cookie->c); 1350 sg.offset = (unsigned long)(&cookie->c) % PAGE_SIZE; 1351 sg.length = bodysize; 1352 keylen = SCTP_SECRET_SIZE; 1353 key = (char *)ep->secret_key[ep->current_key]; 1354 desc.tfm = sctp_sk(ep->base.sk)->hmac; 1355 desc.flags = 0; 1356 1357 if (crypto_hash_setkey(desc.tfm, key, keylen) || 1358 crypto_hash_digest(&desc, &sg, bodysize, cookie->signature)) 1359 goto free_cookie; 1360 } 1361 1362 return retval; 1363 1364 free_cookie: 1365 kfree(retval); 1366 nodata: 1367 *cookie_len = 0; 1368 return NULL; 1369 } 1370 1371 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1372 struct sctp_association *sctp_unpack_cookie( 1373 const struct sctp_endpoint *ep, 1374 const struct sctp_association *asoc, 1375 struct sctp_chunk *chunk, gfp_t gfp, 1376 int *error, struct sctp_chunk **errp) 1377 { 1378 struct sctp_association *retval = NULL; 1379 struct sctp_signed_cookie *cookie; 1380 struct sctp_cookie *bear_cookie; 1381 int headersize, bodysize, fixed_size; 1382 __u8 *digest = ep->digest; 1383 struct scatterlist sg; 1384 unsigned int keylen, len; 1385 char *key; 1386 sctp_scope_t scope; 1387 struct sk_buff *skb = chunk->skb; 1388 struct timeval tv; 1389 struct hash_desc desc; 1390 1391 /* Header size is static data prior to the actual cookie, including 1392 * any padding. 1393 */ 1394 headersize = sizeof(sctp_chunkhdr_t) + 1395 (sizeof(struct sctp_signed_cookie) - 1396 sizeof(struct sctp_cookie)); 1397 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1398 fixed_size = headersize + sizeof(struct sctp_cookie); 1399 1400 /* Verify that the chunk looks like it even has a cookie. 1401 * There must be enough room for our cookie and our peer's 1402 * INIT chunk. 1403 */ 1404 len = ntohs(chunk->chunk_hdr->length); 1405 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1406 goto malformed; 1407 1408 /* Verify that the cookie has been padded out. */ 1409 if (bodysize % SCTP_COOKIE_MULTIPLE) 1410 goto malformed; 1411 1412 /* Process the cookie. */ 1413 cookie = chunk->subh.cookie_hdr; 1414 bear_cookie = &cookie->c; 1415 1416 if (!sctp_sk(ep->base.sk)->hmac) 1417 goto no_hmac; 1418 1419 /* Check the signature. */ 1420 keylen = SCTP_SECRET_SIZE; 1421 sg.page = virt_to_page(bear_cookie); 1422 sg.offset = (unsigned long)(bear_cookie) % PAGE_SIZE; 1423 sg.length = bodysize; 1424 key = (char *)ep->secret_key[ep->current_key]; 1425 desc.tfm = sctp_sk(ep->base.sk)->hmac; 1426 desc.flags = 0; 1427 1428 memset(digest, 0x00, SCTP_SIGNATURE_SIZE); 1429 if (crypto_hash_setkey(desc.tfm, key, keylen) || 1430 crypto_hash_digest(&desc, &sg, bodysize, digest)) { 1431 *error = -SCTP_IERROR_NOMEM; 1432 goto fail; 1433 } 1434 1435 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1436 /* Try the previous key. */ 1437 key = (char *)ep->secret_key[ep->last_key]; 1438 memset(digest, 0x00, SCTP_SIGNATURE_SIZE); 1439 if (crypto_hash_setkey(desc.tfm, key, keylen) || 1440 crypto_hash_digest(&desc, &sg, bodysize, digest)) { 1441 *error = -SCTP_IERROR_NOMEM; 1442 goto fail; 1443 } 1444 1445 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1446 /* Yikes! Still bad signature! */ 1447 *error = -SCTP_IERROR_BAD_SIG; 1448 goto fail; 1449 } 1450 } 1451 1452 no_hmac: 1453 /* IG Section 2.35.2: 1454 * 3) Compare the port numbers and the verification tag contained 1455 * within the COOKIE ECHO chunk to the actual port numbers and the 1456 * verification tag within the SCTP common header of the received 1457 * packet. If these values do not match the packet MUST be silently 1458 * discarded, 1459 */ 1460 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1461 *error = -SCTP_IERROR_BAD_TAG; 1462 goto fail; 1463 } 1464 1465 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1466 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1467 *error = -SCTP_IERROR_BAD_PORTS; 1468 goto fail; 1469 } 1470 1471 /* Check to see if the cookie is stale. If there is already 1472 * an association, there is no need to check cookie's expiration 1473 * for init collision case of lost COOKIE ACK. 1474 * If skb has been timestamped, then use the stamp, otherwise 1475 * use current time. This introduces a small possibility that 1476 * that a cookie may be considered expired, but his would only slow 1477 * down the new association establishment instead of every packet. 1478 */ 1479 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1480 skb_get_timestamp(skb, &tv); 1481 else 1482 do_gettimeofday(&tv); 1483 1484 if (!asoc && tv_lt(bear_cookie->expiration, tv)) { 1485 /* 1486 * Section 3.3.10.3 Stale Cookie Error (3) 1487 * 1488 * Cause of error 1489 * --------------- 1490 * Stale Cookie Error: Indicates the receipt of a valid State 1491 * Cookie that has expired. 1492 */ 1493 len = ntohs(chunk->chunk_hdr->length); 1494 *errp = sctp_make_op_error_space(asoc, chunk, len); 1495 if (*errp) { 1496 suseconds_t usecs = (tv.tv_sec - 1497 bear_cookie->expiration.tv_sec) * 1000000L + 1498 tv.tv_usec - bear_cookie->expiration.tv_usec; 1499 __be32 n = htonl(usecs); 1500 1501 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE, 1502 sizeof(n)); 1503 sctp_addto_chunk(*errp, sizeof(n), &n); 1504 *error = -SCTP_IERROR_STALE_COOKIE; 1505 } else 1506 *error = -SCTP_IERROR_NOMEM; 1507 1508 goto fail; 1509 } 1510 1511 /* Make a new base association. */ 1512 scope = sctp_scope(sctp_source(chunk)); 1513 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1514 if (!retval) { 1515 *error = -SCTP_IERROR_NOMEM; 1516 goto fail; 1517 } 1518 1519 /* Set up our peer's port number. */ 1520 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1521 1522 /* Populate the association from the cookie. */ 1523 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1524 1525 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1526 GFP_ATOMIC) < 0) { 1527 *error = -SCTP_IERROR_NOMEM; 1528 goto fail; 1529 } 1530 1531 /* Also, add the destination address. */ 1532 if (list_empty(&retval->base.bind_addr.address_list)) { 1533 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1, 1534 GFP_ATOMIC); 1535 } 1536 1537 retval->next_tsn = retval->c.initial_tsn; 1538 retval->ctsn_ack_point = retval->next_tsn - 1; 1539 retval->addip_serial = retval->c.initial_tsn; 1540 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1541 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1542 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1543 1544 /* The INIT stuff will be done by the side effects. */ 1545 return retval; 1546 1547 fail: 1548 if (retval) 1549 sctp_association_free(retval); 1550 1551 return NULL; 1552 1553 malformed: 1554 /* Yikes! The packet is either corrupt or deliberately 1555 * malformed. 1556 */ 1557 *error = -SCTP_IERROR_MALFORMED; 1558 goto fail; 1559 } 1560 1561 /******************************************************************** 1562 * 3rd Level Abstractions 1563 ********************************************************************/ 1564 1565 struct __sctp_missing { 1566 __be32 num_missing; 1567 __be16 type; 1568 } __attribute__((packed)); 1569 1570 /* 1571 * Report a missing mandatory parameter. 1572 */ 1573 static int sctp_process_missing_param(const struct sctp_association *asoc, 1574 sctp_param_t paramtype, 1575 struct sctp_chunk *chunk, 1576 struct sctp_chunk **errp) 1577 { 1578 struct __sctp_missing report; 1579 __u16 len; 1580 1581 len = WORD_ROUND(sizeof(report)); 1582 1583 /* Make an ERROR chunk, preparing enough room for 1584 * returning multiple unknown parameters. 1585 */ 1586 if (!*errp) 1587 *errp = sctp_make_op_error_space(asoc, chunk, len); 1588 1589 if (*errp) { 1590 report.num_missing = htonl(1); 1591 report.type = paramtype; 1592 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1593 sizeof(report)); 1594 sctp_addto_chunk(*errp, sizeof(report), &report); 1595 } 1596 1597 /* Stop processing this chunk. */ 1598 return 0; 1599 } 1600 1601 /* Report an Invalid Mandatory Parameter. */ 1602 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1603 struct sctp_chunk *chunk, 1604 struct sctp_chunk **errp) 1605 { 1606 /* Invalid Mandatory Parameter Error has no payload. */ 1607 1608 if (!*errp) 1609 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1610 1611 if (*errp) 1612 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1613 1614 /* Stop processing this chunk. */ 1615 return 0; 1616 } 1617 1618 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1619 struct sctp_paramhdr *param, 1620 const struct sctp_chunk *chunk, 1621 struct sctp_chunk **errp) 1622 { 1623 char error[] = "The following parameter had invalid length:"; 1624 size_t payload_len = WORD_ROUND(sizeof(error)) + 1625 sizeof(sctp_paramhdr_t); 1626 1627 1628 /* Create an error chunk and fill it in with our payload. */ 1629 if (!*errp) 1630 *errp = sctp_make_op_error_space(asoc, chunk, payload_len); 1631 1632 if (*errp) { 1633 sctp_init_cause(*errp, SCTP_ERROR_PROTO_VIOLATION, 1634 sizeof(error) + sizeof(sctp_paramhdr_t)); 1635 sctp_addto_chunk(*errp, sizeof(error), error); 1636 sctp_addto_param(*errp, sizeof(sctp_paramhdr_t), param); 1637 } 1638 1639 return 0; 1640 } 1641 1642 1643 /* Do not attempt to handle the HOST_NAME parm. However, do 1644 * send back an indicator to the peer. 1645 */ 1646 static int sctp_process_hn_param(const struct sctp_association *asoc, 1647 union sctp_params param, 1648 struct sctp_chunk *chunk, 1649 struct sctp_chunk **errp) 1650 { 1651 __u16 len = ntohs(param.p->length); 1652 1653 /* Make an ERROR chunk. */ 1654 if (!*errp) 1655 *errp = sctp_make_op_error_space(asoc, chunk, len); 1656 1657 if (*errp) { 1658 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len); 1659 sctp_addto_chunk(*errp, len, param.v); 1660 } 1661 1662 /* Stop processing this chunk. */ 1663 return 0; 1664 } 1665 1666 /* RFC 3.2.1 & the Implementers Guide 2.2. 1667 * 1668 * The Parameter Types are encoded such that the 1669 * highest-order two bits specify the action that must be 1670 * taken if the processing endpoint does not recognize the 1671 * Parameter Type. 1672 * 1673 * 00 - Stop processing this SCTP chunk and discard it, 1674 * do not process any further chunks within it. 1675 * 1676 * 01 - Stop processing this SCTP chunk and discard it, 1677 * do not process any further chunks within it, and report 1678 * the unrecognized parameter in an 'Unrecognized 1679 * Parameter Type' (in either an ERROR or in the INIT ACK). 1680 * 1681 * 10 - Skip this parameter and continue processing. 1682 * 1683 * 11 - Skip this parameter and continue processing but 1684 * report the unrecognized parameter in an 1685 * 'Unrecognized Parameter Type' (in either an ERROR or in 1686 * the INIT ACK). 1687 * 1688 * Return value: 1689 * 0 - discard the chunk 1690 * 1 - continue with the chunk 1691 */ 1692 static int sctp_process_unk_param(const struct sctp_association *asoc, 1693 union sctp_params param, 1694 struct sctp_chunk *chunk, 1695 struct sctp_chunk **errp) 1696 { 1697 int retval = 1; 1698 1699 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 1700 case SCTP_PARAM_ACTION_DISCARD: 1701 retval = 0; 1702 break; 1703 case SCTP_PARAM_ACTION_DISCARD_ERR: 1704 retval = 0; 1705 /* Make an ERROR chunk, preparing enough room for 1706 * returning multiple unknown parameters. 1707 */ 1708 if (NULL == *errp) 1709 *errp = sctp_make_op_error_space(asoc, chunk, 1710 ntohs(chunk->chunk_hdr->length)); 1711 1712 if (*errp) { 1713 sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, 1714 WORD_ROUND(ntohs(param.p->length))); 1715 sctp_addto_chunk(*errp, 1716 WORD_ROUND(ntohs(param.p->length)), 1717 param.v); 1718 } 1719 1720 break; 1721 case SCTP_PARAM_ACTION_SKIP: 1722 break; 1723 case SCTP_PARAM_ACTION_SKIP_ERR: 1724 /* Make an ERROR chunk, preparing enough room for 1725 * returning multiple unknown parameters. 1726 */ 1727 if (NULL == *errp) 1728 *errp = sctp_make_op_error_space(asoc, chunk, 1729 ntohs(chunk->chunk_hdr->length)); 1730 1731 if (*errp) { 1732 sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, 1733 WORD_ROUND(ntohs(param.p->length))); 1734 sctp_addto_chunk(*errp, 1735 WORD_ROUND(ntohs(param.p->length)), 1736 param.v); 1737 } else { 1738 /* If there is no memory for generating the ERROR 1739 * report as specified, an ABORT will be triggered 1740 * to the peer and the association won't be 1741 * established. 1742 */ 1743 retval = 0; 1744 } 1745 1746 break; 1747 default: 1748 break; 1749 } 1750 1751 return retval; 1752 } 1753 1754 /* Find unrecognized parameters in the chunk. 1755 * Return values: 1756 * 0 - discard the chunk 1757 * 1 - continue with the chunk 1758 */ 1759 static int sctp_verify_param(const struct sctp_association *asoc, 1760 union sctp_params param, 1761 sctp_cid_t cid, 1762 struct sctp_chunk *chunk, 1763 struct sctp_chunk **err_chunk) 1764 { 1765 int retval = 1; 1766 1767 /* FIXME - This routine is not looking at each parameter per the 1768 * chunk type, i.e., unrecognized parameters should be further 1769 * identified based on the chunk id. 1770 */ 1771 1772 switch (param.p->type) { 1773 case SCTP_PARAM_IPV4_ADDRESS: 1774 case SCTP_PARAM_IPV6_ADDRESS: 1775 case SCTP_PARAM_COOKIE_PRESERVATIVE: 1776 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 1777 case SCTP_PARAM_STATE_COOKIE: 1778 case SCTP_PARAM_HEARTBEAT_INFO: 1779 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 1780 case SCTP_PARAM_ECN_CAPABLE: 1781 case SCTP_PARAM_ADAPTATION_LAYER_IND: 1782 break; 1783 1784 case SCTP_PARAM_HOST_NAME_ADDRESS: 1785 /* Tell the peer, we won't support this param. */ 1786 return sctp_process_hn_param(asoc, param, chunk, err_chunk); 1787 case SCTP_PARAM_FWD_TSN_SUPPORT: 1788 if (sctp_prsctp_enable) 1789 break; 1790 /* Fall Through */ 1791 default: 1792 SCTP_DEBUG_PRINTK("Unrecognized param: %d for chunk %d.\n", 1793 ntohs(param.p->type), cid); 1794 return sctp_process_unk_param(asoc, param, chunk, err_chunk); 1795 1796 break; 1797 } 1798 return retval; 1799 } 1800 1801 /* Verify the INIT packet before we process it. */ 1802 int sctp_verify_init(const struct sctp_association *asoc, 1803 sctp_cid_t cid, 1804 sctp_init_chunk_t *peer_init, 1805 struct sctp_chunk *chunk, 1806 struct sctp_chunk **errp) 1807 { 1808 union sctp_params param; 1809 int has_cookie = 0; 1810 1811 /* Verify stream values are non-zero. */ 1812 if ((0 == peer_init->init_hdr.num_outbound_streams) || 1813 (0 == peer_init->init_hdr.num_inbound_streams) || 1814 (0 == peer_init->init_hdr.init_tag) || 1815 (SCTP_DEFAULT_MINWINDOW > ntohl(peer_init->init_hdr.a_rwnd))) { 1816 1817 sctp_process_inv_mandatory(asoc, chunk, errp); 1818 return 0; 1819 } 1820 1821 /* Check for missing mandatory parameters. */ 1822 sctp_walk_params(param, peer_init, init_hdr.params) { 1823 1824 if (SCTP_PARAM_STATE_COOKIE == param.p->type) 1825 has_cookie = 1; 1826 1827 } /* for (loop through all parameters) */ 1828 1829 /* There is a possibility that a parameter length was bad and 1830 * in that case we would have stoped walking the parameters. 1831 * The current param.p would point at the bad one. 1832 * Current consensus on the mailing list is to generate a PROTOCOL 1833 * VIOLATION error. We build the ERROR chunk here and let the normal 1834 * error handling code build and send the packet. 1835 */ 1836 if (param.v != (void*)chunk->chunk_end) { 1837 sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 1838 return 0; 1839 } 1840 1841 /* The only missing mandatory param possible today is 1842 * the state cookie for an INIT-ACK chunk. 1843 */ 1844 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) { 1845 sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 1846 chunk, errp); 1847 return 0; 1848 } 1849 1850 /* Find unrecognized parameters. */ 1851 1852 sctp_walk_params(param, peer_init, init_hdr.params) { 1853 1854 if (!sctp_verify_param(asoc, param, cid, chunk, errp)) { 1855 if (SCTP_PARAM_HOST_NAME_ADDRESS == param.p->type) 1856 return 0; 1857 else 1858 return 1; 1859 } 1860 1861 } /* for (loop through all parameters) */ 1862 1863 return 1; 1864 } 1865 1866 /* Unpack the parameters in an INIT packet into an association. 1867 * Returns 0 on failure, else success. 1868 * FIXME: This is an association method. 1869 */ 1870 int sctp_process_init(struct sctp_association *asoc, sctp_cid_t cid, 1871 const union sctp_addr *peer_addr, 1872 sctp_init_chunk_t *peer_init, gfp_t gfp) 1873 { 1874 union sctp_params param; 1875 struct sctp_transport *transport; 1876 struct list_head *pos, *temp; 1877 char *cookie; 1878 1879 /* We must include the address that the INIT packet came from. 1880 * This is the only address that matters for an INIT packet. 1881 * When processing a COOKIE ECHO, we retrieve the from address 1882 * of the INIT from the cookie. 1883 */ 1884 1885 /* This implementation defaults to making the first transport 1886 * added as the primary transport. The source address seems to 1887 * be a a better choice than any of the embedded addresses. 1888 */ 1889 if (peer_addr) { 1890 if(!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 1891 goto nomem; 1892 } 1893 1894 /* Process the initialization parameters. */ 1895 1896 sctp_walk_params(param, peer_init, init_hdr.params) { 1897 1898 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 1899 goto clean_up; 1900 } 1901 1902 /* Walk list of transports, removing transports in the UNKNOWN state. */ 1903 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 1904 transport = list_entry(pos, struct sctp_transport, transports); 1905 if (transport->state == SCTP_UNKNOWN) { 1906 sctp_assoc_rm_peer(asoc, transport); 1907 } 1908 } 1909 1910 /* The fixed INIT headers are always in network byte 1911 * order. 1912 */ 1913 asoc->peer.i.init_tag = 1914 ntohl(peer_init->init_hdr.init_tag); 1915 asoc->peer.i.a_rwnd = 1916 ntohl(peer_init->init_hdr.a_rwnd); 1917 asoc->peer.i.num_outbound_streams = 1918 ntohs(peer_init->init_hdr.num_outbound_streams); 1919 asoc->peer.i.num_inbound_streams = 1920 ntohs(peer_init->init_hdr.num_inbound_streams); 1921 asoc->peer.i.initial_tsn = 1922 ntohl(peer_init->init_hdr.initial_tsn); 1923 1924 /* Apply the upper bounds for output streams based on peer's 1925 * number of inbound streams. 1926 */ 1927 if (asoc->c.sinit_num_ostreams > 1928 ntohs(peer_init->init_hdr.num_inbound_streams)) { 1929 asoc->c.sinit_num_ostreams = 1930 ntohs(peer_init->init_hdr.num_inbound_streams); 1931 } 1932 1933 if (asoc->c.sinit_max_instreams > 1934 ntohs(peer_init->init_hdr.num_outbound_streams)) { 1935 asoc->c.sinit_max_instreams = 1936 ntohs(peer_init->init_hdr.num_outbound_streams); 1937 } 1938 1939 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 1940 asoc->c.peer_vtag = asoc->peer.i.init_tag; 1941 1942 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 1943 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 1944 1945 /* Copy cookie in case we need to resend COOKIE-ECHO. */ 1946 cookie = asoc->peer.cookie; 1947 if (cookie) { 1948 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp); 1949 if (!asoc->peer.cookie) 1950 goto clean_up; 1951 } 1952 1953 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 1954 * high (for example, implementations MAY use the size of the receiver 1955 * advertised window). 1956 */ 1957 list_for_each(pos, &asoc->peer.transport_addr_list) { 1958 transport = list_entry(pos, struct sctp_transport, transports); 1959 transport->ssthresh = asoc->peer.i.a_rwnd; 1960 } 1961 1962 /* Set up the TSN tracking pieces. */ 1963 sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE, 1964 asoc->peer.i.initial_tsn); 1965 1966 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 1967 * 1968 * The stream sequence number in all the streams shall start 1969 * from 0 when the association is established. Also, when the 1970 * stream sequence number reaches the value 65535 the next 1971 * stream sequence number shall be set to 0. 1972 */ 1973 1974 /* Allocate storage for the negotiated streams if it is not a temporary 1975 * association. 1976 */ 1977 if (!asoc->temp) { 1978 int error; 1979 1980 asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams, 1981 asoc->c.sinit_num_ostreams, gfp); 1982 if (!asoc->ssnmap) 1983 goto clean_up; 1984 1985 error = sctp_assoc_set_id(asoc, gfp); 1986 if (error) 1987 goto clean_up; 1988 } 1989 1990 /* ADDIP Section 4.1 ASCONF Chunk Procedures 1991 * 1992 * When an endpoint has an ASCONF signaled change to be sent to the 1993 * remote endpoint it should do the following: 1994 * ... 1995 * A2) A serial number should be assigned to the Chunk. The serial 1996 * number should be a monotonically increasing number. All serial 1997 * numbers are defined to be initialized at the start of the 1998 * association to the same value as the Initial TSN. 1999 */ 2000 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2001 return 1; 2002 2003 clean_up: 2004 /* Release the transport structures. */ 2005 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2006 transport = list_entry(pos, struct sctp_transport, transports); 2007 list_del_init(pos); 2008 sctp_transport_free(transport); 2009 } 2010 2011 asoc->peer.transport_count = 0; 2012 2013 nomem: 2014 return 0; 2015 } 2016 2017 2018 /* Update asoc with the option described in param. 2019 * 2020 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2021 * 2022 * asoc is the association to update. 2023 * param is the variable length parameter to use for update. 2024 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2025 * If the current packet is an INIT we want to minimize the amount of 2026 * work we do. In particular, we should not build transport 2027 * structures for the addresses. 2028 */ 2029 static int sctp_process_param(struct sctp_association *asoc, 2030 union sctp_params param, 2031 const union sctp_addr *peer_addr, 2032 gfp_t gfp) 2033 { 2034 union sctp_addr addr; 2035 int i; 2036 __u16 sat; 2037 int retval = 1; 2038 sctp_scope_t scope; 2039 time_t stale; 2040 struct sctp_af *af; 2041 2042 /* We maintain all INIT parameters in network byte order all the 2043 * time. This allows us to not worry about whether the parameters 2044 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2045 */ 2046 switch (param.p->type) { 2047 case SCTP_PARAM_IPV6_ADDRESS: 2048 if (PF_INET6 != asoc->base.sk->sk_family) 2049 break; 2050 /* Fall through. */ 2051 case SCTP_PARAM_IPV4_ADDRESS: 2052 af = sctp_get_af_specific(param_type2af(param.p->type)); 2053 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); 2054 scope = sctp_scope(peer_addr); 2055 if (sctp_in_scope(&addr, scope)) 2056 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2057 return 0; 2058 break; 2059 2060 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2061 if (!sctp_cookie_preserve_enable) 2062 break; 2063 2064 stale = ntohl(param.life->lifespan_increment); 2065 2066 /* Suggested Cookie Life span increment's unit is msec, 2067 * (1/1000sec). 2068 */ 2069 asoc->cookie_life.tv_sec += stale / 1000; 2070 asoc->cookie_life.tv_usec += (stale % 1000) * 1000; 2071 break; 2072 2073 case SCTP_PARAM_HOST_NAME_ADDRESS: 2074 SCTP_DEBUG_PRINTK("unimplemented SCTP_HOST_NAME_ADDRESS\n"); 2075 break; 2076 2077 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2078 /* Turn off the default values first so we'll know which 2079 * ones are really set by the peer. 2080 */ 2081 asoc->peer.ipv4_address = 0; 2082 asoc->peer.ipv6_address = 0; 2083 2084 /* Cycle through address types; avoid divide by 0. */ 2085 sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2086 if (sat) 2087 sat /= sizeof(__u16); 2088 2089 for (i = 0; i < sat; ++i) { 2090 switch (param.sat->types[i]) { 2091 case SCTP_PARAM_IPV4_ADDRESS: 2092 asoc->peer.ipv4_address = 1; 2093 break; 2094 2095 case SCTP_PARAM_IPV6_ADDRESS: 2096 asoc->peer.ipv6_address = 1; 2097 break; 2098 2099 case SCTP_PARAM_HOST_NAME_ADDRESS: 2100 asoc->peer.hostname_address = 1; 2101 break; 2102 2103 default: /* Just ignore anything else. */ 2104 break; 2105 } 2106 } 2107 break; 2108 2109 case SCTP_PARAM_STATE_COOKIE: 2110 asoc->peer.cookie_len = 2111 ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2112 asoc->peer.cookie = param.cookie->body; 2113 break; 2114 2115 case SCTP_PARAM_HEARTBEAT_INFO: 2116 /* Would be odd to receive, but it causes no problems. */ 2117 break; 2118 2119 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2120 /* Rejected during verify stage. */ 2121 break; 2122 2123 case SCTP_PARAM_ECN_CAPABLE: 2124 asoc->peer.ecn_capable = 1; 2125 break; 2126 2127 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2128 asoc->peer.adaptation_ind = param.aind->adaptation_ind; 2129 break; 2130 2131 case SCTP_PARAM_FWD_TSN_SUPPORT: 2132 if (sctp_prsctp_enable) { 2133 asoc->peer.prsctp_capable = 1; 2134 break; 2135 } 2136 /* Fall Through */ 2137 default: 2138 /* Any unrecognized parameters should have been caught 2139 * and handled by sctp_verify_param() which should be 2140 * called prior to this routine. Simply log the error 2141 * here. 2142 */ 2143 SCTP_DEBUG_PRINTK("Ignoring param: %d for association %p.\n", 2144 ntohs(param.p->type), asoc); 2145 break; 2146 } 2147 2148 return retval; 2149 } 2150 2151 /* Select a new verification tag. */ 2152 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2153 { 2154 /* I believe that this random number generator complies with RFC1750. 2155 * A tag of 0 is reserved for special cases (e.g. INIT). 2156 */ 2157 __u32 x; 2158 2159 do { 2160 get_random_bytes(&x, sizeof(__u32)); 2161 } while (x == 0); 2162 2163 return x; 2164 } 2165 2166 /* Select an initial TSN to send during startup. */ 2167 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2168 { 2169 __u32 retval; 2170 2171 get_random_bytes(&retval, sizeof(__u32)); 2172 return retval; 2173 } 2174 2175 /* 2176 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2177 * 0 1 2 3 2178 * 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 2179 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2180 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2181 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2182 * | Serial Number | 2183 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2184 * | Address Parameter | 2185 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2186 * | ASCONF Parameter #1 | 2187 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2188 * \ \ 2189 * / .... / 2190 * \ \ 2191 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2192 * | ASCONF Parameter #N | 2193 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2194 * 2195 * Address Parameter and other parameter will not be wrapped in this function 2196 */ 2197 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2198 union sctp_addr *addr, 2199 int vparam_len) 2200 { 2201 sctp_addiphdr_t asconf; 2202 struct sctp_chunk *retval; 2203 int length = sizeof(asconf) + vparam_len; 2204 union sctp_addr_param addrparam; 2205 int addrlen; 2206 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2207 2208 addrlen = af->to_addr_param(addr, &addrparam); 2209 if (!addrlen) 2210 return NULL; 2211 length += addrlen; 2212 2213 /* Create the chunk. */ 2214 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF, 0, length); 2215 if (!retval) 2216 return NULL; 2217 2218 asconf.serial = htonl(asoc->addip_serial++); 2219 2220 retval->subh.addip_hdr = 2221 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2222 retval->param_hdr.v = 2223 sctp_addto_chunk(retval, addrlen, &addrparam); 2224 2225 return retval; 2226 } 2227 2228 /* ADDIP 2229 * 3.2.1 Add IP Address 2230 * 0 1 2 3 2231 * 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 2232 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2233 * | Type = 0xC001 | Length = Variable | 2234 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2235 * | ASCONF-Request Correlation ID | 2236 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2237 * | Address Parameter | 2238 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2239 * 2240 * 3.2.2 Delete IP Address 2241 * 0 1 2 3 2242 * 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 2243 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2244 * | Type = 0xC002 | Length = Variable | 2245 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2246 * | ASCONF-Request Correlation ID | 2247 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2248 * | Address Parameter | 2249 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2250 * 2251 */ 2252 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2253 union sctp_addr *laddr, 2254 struct sockaddr *addrs, 2255 int addrcnt, 2256 __be16 flags) 2257 { 2258 sctp_addip_param_t param; 2259 struct sctp_chunk *retval; 2260 union sctp_addr_param addr_param; 2261 union sctp_addr *addr; 2262 void *addr_buf; 2263 struct sctp_af *af; 2264 int paramlen = sizeof(param); 2265 int addr_param_len = 0; 2266 int totallen = 0; 2267 int i; 2268 2269 /* Get total length of all the address parameters. */ 2270 addr_buf = addrs; 2271 for (i = 0; i < addrcnt; i++) { 2272 addr = (union sctp_addr *)addr_buf; 2273 af = sctp_get_af_specific(addr->v4.sin_family); 2274 addr_param_len = af->to_addr_param(addr, &addr_param); 2275 2276 totallen += paramlen; 2277 totallen += addr_param_len; 2278 2279 addr_buf += af->sockaddr_len; 2280 } 2281 2282 /* Create an asconf chunk with the required length. */ 2283 retval = sctp_make_asconf(asoc, laddr, totallen); 2284 if (!retval) 2285 return NULL; 2286 2287 /* Add the address parameters to the asconf chunk. */ 2288 addr_buf = addrs; 2289 for (i = 0; i < addrcnt; i++) { 2290 addr = (union sctp_addr *)addr_buf; 2291 af = sctp_get_af_specific(addr->v4.sin_family); 2292 addr_param_len = af->to_addr_param(addr, &addr_param); 2293 param.param_hdr.type = flags; 2294 param.param_hdr.length = htons(paramlen + addr_param_len); 2295 param.crr_id = i; 2296 2297 sctp_addto_chunk(retval, paramlen, ¶m); 2298 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2299 2300 addr_buf += af->sockaddr_len; 2301 } 2302 return retval; 2303 } 2304 2305 /* ADDIP 2306 * 3.2.4 Set Primary IP Address 2307 * 0 1 2 3 2308 * 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 2309 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2310 * | Type =0xC004 | Length = Variable | 2311 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2312 * | ASCONF-Request Correlation ID | 2313 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2314 * | Address Parameter | 2315 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2316 * 2317 * Create an ASCONF chunk with Set Primary IP address parameter. 2318 */ 2319 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2320 union sctp_addr *addr) 2321 { 2322 sctp_addip_param_t param; 2323 struct sctp_chunk *retval; 2324 int len = sizeof(param); 2325 union sctp_addr_param addrparam; 2326 int addrlen; 2327 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2328 2329 addrlen = af->to_addr_param(addr, &addrparam); 2330 if (!addrlen) 2331 return NULL; 2332 len += addrlen; 2333 2334 /* Create the chunk and make asconf header. */ 2335 retval = sctp_make_asconf(asoc, addr, len); 2336 if (!retval) 2337 return NULL; 2338 2339 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2340 param.param_hdr.length = htons(len); 2341 param.crr_id = 0; 2342 2343 sctp_addto_chunk(retval, sizeof(param), ¶m); 2344 sctp_addto_chunk(retval, addrlen, &addrparam); 2345 2346 return retval; 2347 } 2348 2349 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2350 * 0 1 2 3 2351 * 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 2352 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2353 * | Type = 0x80 | Chunk Flags | Chunk Length | 2354 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2355 * | Serial Number | 2356 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2357 * | ASCONF Parameter Response#1 | 2358 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2359 * \ \ 2360 * / .... / 2361 * \ \ 2362 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2363 * | ASCONF Parameter Response#N | 2364 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2365 * 2366 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2367 */ 2368 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2369 __u32 serial, int vparam_len) 2370 { 2371 sctp_addiphdr_t asconf; 2372 struct sctp_chunk *retval; 2373 int length = sizeof(asconf) + vparam_len; 2374 2375 /* Create the chunk. */ 2376 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF_ACK, 0, length); 2377 if (!retval) 2378 return NULL; 2379 2380 asconf.serial = htonl(serial); 2381 2382 retval->subh.addip_hdr = 2383 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2384 2385 return retval; 2386 } 2387 2388 /* Add response parameters to an ASCONF_ACK chunk. */ 2389 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2390 __be16 err_code, sctp_addip_param_t *asconf_param) 2391 { 2392 sctp_addip_param_t ack_param; 2393 sctp_errhdr_t err_param; 2394 int asconf_param_len = 0; 2395 int err_param_len = 0; 2396 __be16 response_type; 2397 2398 if (SCTP_ERROR_NO_ERROR == err_code) { 2399 response_type = SCTP_PARAM_SUCCESS_REPORT; 2400 } else { 2401 response_type = SCTP_PARAM_ERR_CAUSE; 2402 err_param_len = sizeof(err_param); 2403 if (asconf_param) 2404 asconf_param_len = 2405 ntohs(asconf_param->param_hdr.length); 2406 } 2407 2408 /* Add Success Indication or Error Cause Indication parameter. */ 2409 ack_param.param_hdr.type = response_type; 2410 ack_param.param_hdr.length = htons(sizeof(ack_param) + 2411 err_param_len + 2412 asconf_param_len); 2413 ack_param.crr_id = crr_id; 2414 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 2415 2416 if (SCTP_ERROR_NO_ERROR == err_code) 2417 return; 2418 2419 /* Add Error Cause parameter. */ 2420 err_param.cause = err_code; 2421 err_param.length = htons(err_param_len + asconf_param_len); 2422 sctp_addto_chunk(chunk, err_param_len, &err_param); 2423 2424 /* Add the failed TLV copied from ASCONF chunk. */ 2425 if (asconf_param) 2426 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 2427 } 2428 2429 /* Process a asconf parameter. */ 2430 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 2431 struct sctp_chunk *asconf, 2432 sctp_addip_param_t *asconf_param) 2433 { 2434 struct sctp_transport *peer; 2435 struct sctp_af *af; 2436 union sctp_addr addr; 2437 struct list_head *pos; 2438 union sctp_addr_param *addr_param; 2439 2440 addr_param = (union sctp_addr_param *) 2441 ((void *)asconf_param + sizeof(sctp_addip_param_t)); 2442 2443 af = sctp_get_af_specific(param_type2af(addr_param->v4.param_hdr.type)); 2444 if (unlikely(!af)) 2445 return SCTP_ERROR_INV_PARAM; 2446 2447 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); 2448 switch (asconf_param->param_hdr.type) { 2449 case SCTP_PARAM_ADD_IP: 2450 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 2451 * request and does not have the local resources to add this 2452 * new address to the association, it MUST return an Error 2453 * Cause TLV set to the new error code 'Operation Refused 2454 * Due to Resource Shortage'. 2455 */ 2456 2457 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 2458 if (!peer) 2459 return SCTP_ERROR_RSRC_LOW; 2460 2461 /* Start the heartbeat timer. */ 2462 if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer))) 2463 sctp_transport_hold(peer); 2464 break; 2465 case SCTP_PARAM_DEL_IP: 2466 /* ADDIP 4.3 D7) If a request is received to delete the 2467 * last remaining IP address of a peer endpoint, the receiver 2468 * MUST send an Error Cause TLV with the error cause set to the 2469 * new error code 'Request to Delete Last Remaining IP Address'. 2470 */ 2471 pos = asoc->peer.transport_addr_list.next; 2472 if (pos->next == &asoc->peer.transport_addr_list) 2473 return SCTP_ERROR_DEL_LAST_IP; 2474 2475 /* ADDIP 4.3 D8) If a request is received to delete an IP 2476 * address which is also the source address of the IP packet 2477 * which contained the ASCONF chunk, the receiver MUST reject 2478 * this request. To reject the request the receiver MUST send 2479 * an Error Cause TLV set to the new error code 'Request to 2480 * Delete Source IP Address' 2481 */ 2482 if (sctp_cmp_addr_exact(sctp_source(asconf), &addr)) 2483 return SCTP_ERROR_DEL_SRC_IP; 2484 2485 sctp_assoc_del_peer(asoc, &addr); 2486 break; 2487 case SCTP_PARAM_SET_PRIMARY: 2488 peer = sctp_assoc_lookup_paddr(asoc, &addr); 2489 if (!peer) 2490 return SCTP_ERROR_INV_PARAM; 2491 2492 sctp_assoc_set_primary(asoc, peer); 2493 break; 2494 default: 2495 return SCTP_ERROR_INV_PARAM; 2496 break; 2497 } 2498 2499 return SCTP_ERROR_NO_ERROR; 2500 } 2501 2502 /* Process an incoming ASCONF chunk with the next expected serial no. and 2503 * return an ASCONF_ACK chunk to be sent in response. 2504 */ 2505 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 2506 struct sctp_chunk *asconf) 2507 { 2508 sctp_addiphdr_t *hdr; 2509 union sctp_addr_param *addr_param; 2510 sctp_addip_param_t *asconf_param; 2511 struct sctp_chunk *asconf_ack; 2512 2513 __be16 err_code; 2514 int length = 0; 2515 int chunk_len = asconf->skb->len; 2516 __u32 serial; 2517 int all_param_pass = 1; 2518 2519 hdr = (sctp_addiphdr_t *)asconf->skb->data; 2520 serial = ntohl(hdr->serial); 2521 2522 /* Skip the addiphdr and store a pointer to address parameter. */ 2523 length = sizeof(sctp_addiphdr_t); 2524 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 2525 chunk_len -= length; 2526 2527 /* Skip the address parameter and store a pointer to the first 2528 * asconf paramter. 2529 */ 2530 length = ntohs(addr_param->v4.param_hdr.length); 2531 asconf_param = (sctp_addip_param_t *)((void *)addr_param + length); 2532 chunk_len -= length; 2533 2534 /* create an ASCONF_ACK chunk. 2535 * Based on the definitions of parameters, we know that the size of 2536 * ASCONF_ACK parameters are less than or equal to the twice of ASCONF 2537 * paramters. 2538 */ 2539 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 2); 2540 if (!asconf_ack) 2541 goto done; 2542 2543 /* Process the TLVs contained within the ASCONF chunk. */ 2544 while (chunk_len > 0) { 2545 err_code = sctp_process_asconf_param(asoc, asconf, 2546 asconf_param); 2547 /* ADDIP 4.1 A7) 2548 * If an error response is received for a TLV parameter, 2549 * all TLVs with no response before the failed TLV are 2550 * considered successful if not reported. All TLVs after 2551 * the failed response are considered unsuccessful unless 2552 * a specific success indication is present for the parameter. 2553 */ 2554 if (SCTP_ERROR_NO_ERROR != err_code) 2555 all_param_pass = 0; 2556 2557 if (!all_param_pass) 2558 sctp_add_asconf_response(asconf_ack, 2559 asconf_param->crr_id, err_code, 2560 asconf_param); 2561 2562 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 2563 * an IP address sends an 'Out of Resource' in its response, it 2564 * MUST also fail any subsequent add or delete requests bundled 2565 * in the ASCONF. 2566 */ 2567 if (SCTP_ERROR_RSRC_LOW == err_code) 2568 goto done; 2569 2570 /* Move to the next ASCONF param. */ 2571 length = ntohs(asconf_param->param_hdr.length); 2572 asconf_param = (sctp_addip_param_t *)((void *)asconf_param + 2573 length); 2574 chunk_len -= length; 2575 } 2576 2577 done: 2578 asoc->peer.addip_serial++; 2579 2580 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 2581 * after freeing the reference to old asconf ack if any. 2582 */ 2583 if (asconf_ack) { 2584 if (asoc->addip_last_asconf_ack) 2585 sctp_chunk_free(asoc->addip_last_asconf_ack); 2586 2587 sctp_chunk_hold(asconf_ack); 2588 asoc->addip_last_asconf_ack = asconf_ack; 2589 } 2590 2591 return asconf_ack; 2592 } 2593 2594 /* Process a asconf parameter that is successfully acked. */ 2595 static int sctp_asconf_param_success(struct sctp_association *asoc, 2596 sctp_addip_param_t *asconf_param) 2597 { 2598 struct sctp_af *af; 2599 union sctp_addr addr; 2600 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 2601 union sctp_addr_param *addr_param; 2602 struct list_head *pos; 2603 struct sctp_transport *transport; 2604 struct sctp_sockaddr_entry *saddr; 2605 int retval = 0; 2606 2607 addr_param = (union sctp_addr_param *) 2608 ((void *)asconf_param + sizeof(sctp_addip_param_t)); 2609 2610 /* We have checked the packet before, so we do not check again. */ 2611 af = sctp_get_af_specific(param_type2af(addr_param->v4.param_hdr.type)); 2612 af->from_addr_param(&addr, addr_param, htons(bp->port), 0); 2613 2614 switch (asconf_param->param_hdr.type) { 2615 case SCTP_PARAM_ADD_IP: 2616 /* This is always done in BH context with a socket lock 2617 * held, so the list can not change. 2618 */ 2619 list_for_each_entry(saddr, &bp->address_list, list) { 2620 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 2621 saddr->use_as_src = 1; 2622 } 2623 break; 2624 case SCTP_PARAM_DEL_IP: 2625 retval = sctp_del_bind_addr(bp, &addr, call_rcu_bh); 2626 list_for_each(pos, &asoc->peer.transport_addr_list) { 2627 transport = list_entry(pos, struct sctp_transport, 2628 transports); 2629 dst_release(transport->dst); 2630 sctp_transport_route(transport, NULL, 2631 sctp_sk(asoc->base.sk)); 2632 } 2633 break; 2634 default: 2635 break; 2636 } 2637 2638 return retval; 2639 } 2640 2641 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 2642 * for the given asconf parameter. If there is no response for this parameter, 2643 * return the error code based on the third argument 'no_err'. 2644 * ADDIP 4.1 2645 * A7) If an error response is received for a TLV parameter, all TLVs with no 2646 * response before the failed TLV are considered successful if not reported. 2647 * All TLVs after the failed response are considered unsuccessful unless a 2648 * specific success indication is present for the parameter. 2649 */ 2650 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 2651 sctp_addip_param_t *asconf_param, 2652 int no_err) 2653 { 2654 sctp_addip_param_t *asconf_ack_param; 2655 sctp_errhdr_t *err_param; 2656 int length; 2657 int asconf_ack_len = asconf_ack->skb->len; 2658 __be16 err_code; 2659 2660 if (no_err) 2661 err_code = SCTP_ERROR_NO_ERROR; 2662 else 2663 err_code = SCTP_ERROR_REQ_REFUSED; 2664 2665 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 2666 * the first asconf_ack parameter. 2667 */ 2668 length = sizeof(sctp_addiphdr_t); 2669 asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data + 2670 length); 2671 asconf_ack_len -= length; 2672 2673 while (asconf_ack_len > 0) { 2674 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 2675 switch(asconf_ack_param->param_hdr.type) { 2676 case SCTP_PARAM_SUCCESS_REPORT: 2677 return SCTP_ERROR_NO_ERROR; 2678 case SCTP_PARAM_ERR_CAUSE: 2679 length = sizeof(sctp_addip_param_t); 2680 err_param = (sctp_errhdr_t *) 2681 ((void *)asconf_ack_param + length); 2682 asconf_ack_len -= length; 2683 if (asconf_ack_len > 0) 2684 return err_param->cause; 2685 else 2686 return SCTP_ERROR_INV_PARAM; 2687 break; 2688 default: 2689 return SCTP_ERROR_INV_PARAM; 2690 } 2691 } 2692 2693 length = ntohs(asconf_ack_param->param_hdr.length); 2694 asconf_ack_param = (sctp_addip_param_t *) 2695 ((void *)asconf_ack_param + length); 2696 asconf_ack_len -= length; 2697 } 2698 2699 return err_code; 2700 } 2701 2702 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 2703 int sctp_process_asconf_ack(struct sctp_association *asoc, 2704 struct sctp_chunk *asconf_ack) 2705 { 2706 struct sctp_chunk *asconf = asoc->addip_last_asconf; 2707 union sctp_addr_param *addr_param; 2708 sctp_addip_param_t *asconf_param; 2709 int length = 0; 2710 int asconf_len = asconf->skb->len; 2711 int all_param_pass = 0; 2712 int no_err = 1; 2713 int retval = 0; 2714 __be16 err_code = SCTP_ERROR_NO_ERROR; 2715 2716 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 2717 * a pointer to address parameter. 2718 */ 2719 length = sizeof(sctp_addip_chunk_t); 2720 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 2721 asconf_len -= length; 2722 2723 /* Skip the address parameter in the last asconf sent and store a 2724 * pointer to the first asconf paramter. 2725 */ 2726 length = ntohs(addr_param->v4.param_hdr.length); 2727 asconf_param = (sctp_addip_param_t *)((void *)addr_param + length); 2728 asconf_len -= length; 2729 2730 /* ADDIP 4.1 2731 * A8) If there is no response(s) to specific TLV parameter(s), and no 2732 * failures are indicated, then all request(s) are considered 2733 * successful. 2734 */ 2735 if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t)) 2736 all_param_pass = 1; 2737 2738 /* Process the TLVs contained in the last sent ASCONF chunk. */ 2739 while (asconf_len > 0) { 2740 if (all_param_pass) 2741 err_code = SCTP_ERROR_NO_ERROR; 2742 else { 2743 err_code = sctp_get_asconf_response(asconf_ack, 2744 asconf_param, 2745 no_err); 2746 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 2747 no_err = 0; 2748 } 2749 2750 switch (err_code) { 2751 case SCTP_ERROR_NO_ERROR: 2752 retval = sctp_asconf_param_success(asoc, asconf_param); 2753 break; 2754 2755 case SCTP_ERROR_RSRC_LOW: 2756 retval = 1; 2757 break; 2758 2759 case SCTP_ERROR_INV_PARAM: 2760 /* Disable sending this type of asconf parameter in 2761 * future. 2762 */ 2763 asoc->peer.addip_disabled_mask |= 2764 asconf_param->param_hdr.type; 2765 break; 2766 2767 case SCTP_ERROR_REQ_REFUSED: 2768 case SCTP_ERROR_DEL_LAST_IP: 2769 case SCTP_ERROR_DEL_SRC_IP: 2770 default: 2771 break; 2772 } 2773 2774 /* Skip the processed asconf parameter and move to the next 2775 * one. 2776 */ 2777 length = ntohs(asconf_param->param_hdr.length); 2778 asconf_param = (sctp_addip_param_t *)((void *)asconf_param + 2779 length); 2780 asconf_len -= length; 2781 } 2782 2783 /* Free the cached last sent asconf chunk. */ 2784 sctp_chunk_free(asconf); 2785 asoc->addip_last_asconf = NULL; 2786 2787 /* Send the next asconf chunk from the addip chunk queue. */ 2788 if (!list_empty(&asoc->addip_chunk_list)) { 2789 struct list_head *entry = asoc->addip_chunk_list.next; 2790 asconf = list_entry(entry, struct sctp_chunk, list); 2791 2792 list_del_init(entry); 2793 2794 /* Hold the chunk until an ASCONF_ACK is received. */ 2795 sctp_chunk_hold(asconf); 2796 if (sctp_primitive_ASCONF(asoc, asconf)) 2797 sctp_chunk_free(asconf); 2798 else 2799 asoc->addip_last_asconf = asconf; 2800 } 2801 2802 return retval; 2803 } 2804 2805 /* Make a FWD TSN chunk. */ 2806 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 2807 __u32 new_cum_tsn, size_t nstreams, 2808 struct sctp_fwdtsn_skip *skiplist) 2809 { 2810 struct sctp_chunk *retval = NULL; 2811 struct sctp_fwdtsn_chunk *ftsn_chunk; 2812 struct sctp_fwdtsn_hdr ftsn_hdr; 2813 struct sctp_fwdtsn_skip skip; 2814 size_t hint; 2815 int i; 2816 2817 hint = (nstreams + 1) * sizeof(__u32); 2818 2819 retval = sctp_make_chunk(asoc, SCTP_CID_FWD_TSN, 0, hint); 2820 2821 if (!retval) 2822 return NULL; 2823 2824 ftsn_chunk = (struct sctp_fwdtsn_chunk *)retval->subh.fwdtsn_hdr; 2825 2826 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 2827 retval->subh.fwdtsn_hdr = 2828 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 2829 2830 for (i = 0; i < nstreams; i++) { 2831 skip.stream = skiplist[i].stream; 2832 skip.ssn = skiplist[i].ssn; 2833 sctp_addto_chunk(retval, sizeof(skip), &skip); 2834 } 2835 2836 return retval; 2837 } 2838