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 <linux/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 sctp_supported_ext_param_t ext_param; 183 int num_ext = 0; 184 __u8 extensions[3]; 185 sctp_paramhdr_t *auth_chunks = NULL, 186 *auth_hmacs = NULL; 187 188 /* RFC 2960 3.3.2 Initiation (INIT) (1) 189 * 190 * Note 1: The INIT chunks can contain multiple addresses that 191 * can be IPv4 and/or IPv6 in any combination. 192 */ 193 retval = NULL; 194 195 /* Convert the provided bind address list to raw format. */ 196 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp); 197 198 init.init_tag = htonl(asoc->c.my_vtag); 199 init.a_rwnd = htonl(asoc->rwnd); 200 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 201 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 202 init.initial_tsn = htonl(asoc->c.initial_tsn); 203 204 /* How many address types are needed? */ 205 sp = sctp_sk(asoc->base.sk); 206 num_types = sp->pf->supported_addrs(sp, types); 207 208 chunksize = sizeof(init) + addrs_len + SCTP_SAT_LEN(num_types); 209 chunksize += sizeof(ecap_param); 210 if (sctp_prsctp_enable) { 211 chunksize += sizeof(prsctp_param); 212 extensions[num_ext] = SCTP_CID_FWD_TSN; 213 num_ext += 1; 214 } 215 /* ADDIP: Section 4.2.7: 216 * An implementation supporting this extension [ADDIP] MUST list 217 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and 218 * INIT-ACK parameters. 219 */ 220 if (sctp_addip_enable) { 221 extensions[num_ext] = SCTP_CID_ASCONF; 222 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 223 num_ext += 2; 224 } 225 226 chunksize += sizeof(aiparam); 227 chunksize += vparam_len; 228 229 /* Account for AUTH related parameters */ 230 if (sctp_auth_enable) { 231 /* Add random parameter length*/ 232 chunksize += sizeof(asoc->c.auth_random); 233 234 /* Add HMACS parameter length if any were defined */ 235 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs; 236 if (auth_hmacs->length) 237 chunksize += ntohs(auth_hmacs->length); 238 else 239 auth_hmacs = NULL; 240 241 /* Add CHUNKS parameter length */ 242 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks; 243 if (auth_chunks->length) 244 chunksize += ntohs(auth_chunks->length); 245 else 246 auth_hmacs = NULL; 247 248 extensions[num_ext] = SCTP_CID_AUTH; 249 num_ext += 1; 250 } 251 252 /* If we have any extensions to report, account for that */ 253 if (num_ext) 254 chunksize += sizeof(sctp_supported_ext_param_t) + num_ext; 255 256 /* RFC 2960 3.3.2 Initiation (INIT) (1) 257 * 258 * Note 3: An INIT chunk MUST NOT contain more than one Host 259 * Name address parameter. Moreover, the sender of the INIT 260 * MUST NOT combine any other address types with the Host Name 261 * address in the INIT. The receiver of INIT MUST ignore any 262 * other address types if the Host Name address parameter is 263 * present in the received INIT chunk. 264 * 265 * PLEASE DO NOT FIXME [This version does not support Host Name.] 266 */ 267 268 retval = sctp_make_chunk(asoc, SCTP_CID_INIT, 0, chunksize); 269 if (!retval) 270 goto nodata; 271 272 retval->subh.init_hdr = 273 sctp_addto_chunk(retval, sizeof(init), &init); 274 retval->param_hdr.v = 275 sctp_addto_chunk(retval, addrs_len, addrs.v); 276 277 /* RFC 2960 3.3.2 Initiation (INIT) (1) 278 * 279 * Note 4: This parameter, when present, specifies all the 280 * address types the sending endpoint can support. The absence 281 * of this parameter indicates that the sending endpoint can 282 * support any address type. 283 */ 284 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES; 285 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types)); 286 sctp_addto_chunk(retval, sizeof(sat), &sat); 287 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types); 288 289 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 290 291 /* Add the supported extensions paramter. Be nice and add this 292 * fist before addiding the parameters for the extensions themselves 293 */ 294 if (num_ext) { 295 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 296 ext_param.param_hdr.length = 297 htons(sizeof(sctp_supported_ext_param_t) + num_ext); 298 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t), 299 &ext_param); 300 sctp_addto_chunk(retval, num_ext, extensions); 301 } 302 303 if (sctp_prsctp_enable) 304 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 305 306 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 307 aiparam.param_hdr.length = htons(sizeof(aiparam)); 308 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 309 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 310 311 /* Add SCTP-AUTH chunks to the parameter list */ 312 if (sctp_auth_enable) { 313 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random), 314 asoc->c.auth_random); 315 if (auth_hmacs) 316 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 317 auth_hmacs); 318 if (auth_chunks) 319 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 320 auth_chunks); 321 } 322 nodata: 323 kfree(addrs.v); 324 return retval; 325 } 326 327 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, 328 const struct sctp_chunk *chunk, 329 gfp_t gfp, int unkparam_len) 330 { 331 sctp_inithdr_t initack; 332 struct sctp_chunk *retval; 333 union sctp_params addrs; 334 int addrs_len; 335 sctp_cookie_param_t *cookie; 336 int cookie_len; 337 size_t chunksize; 338 sctp_adaptation_ind_param_t aiparam; 339 sctp_supported_ext_param_t ext_param; 340 int num_ext = 0; 341 __u8 extensions[3]; 342 sctp_paramhdr_t *auth_chunks = NULL, 343 *auth_hmacs = NULL, 344 *auth_random = NULL; 345 346 retval = NULL; 347 348 /* Note: there may be no addresses to embed. */ 349 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp); 350 351 initack.init_tag = htonl(asoc->c.my_vtag); 352 initack.a_rwnd = htonl(asoc->rwnd); 353 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 354 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 355 initack.initial_tsn = htonl(asoc->c.initial_tsn); 356 357 /* FIXME: We really ought to build the cookie right 358 * into the packet instead of allocating more fresh memory. 359 */ 360 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len, 361 addrs.v, addrs_len); 362 if (!cookie) 363 goto nomem_cookie; 364 365 /* Calculate the total size of allocation, include the reserved 366 * space for reporting unknown parameters if it is specified. 367 */ 368 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len; 369 370 /* Tell peer that we'll do ECN only if peer advertised such cap. */ 371 if (asoc->peer.ecn_capable) 372 chunksize += sizeof(ecap_param); 373 374 /* Tell peer that we'll do PR-SCTP only if peer advertised. */ 375 if (asoc->peer.prsctp_capable) { 376 chunksize += sizeof(prsctp_param); 377 extensions[num_ext] = SCTP_CID_FWD_TSN; 378 num_ext += 1; 379 } 380 381 if (sctp_addip_enable) { 382 extensions[num_ext] = SCTP_CID_ASCONF; 383 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 384 num_ext += 2; 385 } 386 387 chunksize += sizeof(ext_param) + num_ext; 388 chunksize += sizeof(aiparam); 389 390 if (asoc->peer.auth_capable) { 391 auth_random = (sctp_paramhdr_t *)asoc->c.auth_random; 392 chunksize += ntohs(auth_random->length); 393 394 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs; 395 if (auth_hmacs->length) 396 chunksize += ntohs(auth_hmacs->length); 397 else 398 auth_hmacs = NULL; 399 400 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks; 401 if (auth_chunks->length) 402 chunksize += ntohs(auth_chunks->length); 403 else 404 auth_chunks = NULL; 405 406 extensions[num_ext] = SCTP_CID_AUTH; 407 num_ext += 1; 408 } 409 410 /* Now allocate and fill out the chunk. */ 411 retval = sctp_make_chunk(asoc, SCTP_CID_INIT_ACK, 0, chunksize); 412 if (!retval) 413 goto nomem_chunk; 414 415 /* Per the advice in RFC 2960 6.4, send this reply to 416 * the source of the INIT packet. 417 */ 418 retval->transport = chunk->transport; 419 retval->subh.init_hdr = 420 sctp_addto_chunk(retval, sizeof(initack), &initack); 421 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); 422 sctp_addto_chunk(retval, cookie_len, cookie); 423 if (asoc->peer.ecn_capable) 424 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 425 if (num_ext) { 426 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 427 ext_param.param_hdr.length = 428 htons(sizeof(sctp_supported_ext_param_t) + num_ext); 429 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t), 430 &ext_param); 431 sctp_addto_chunk(retval, num_ext, extensions); 432 } 433 if (asoc->peer.prsctp_capable) 434 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 435 436 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 437 aiparam.param_hdr.length = htons(sizeof(aiparam)); 438 aiparam.adaptation_ind = htonl(sctp_sk(asoc->base.sk)->adaptation_ind); 439 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 440 441 if (asoc->peer.auth_capable) { 442 sctp_addto_chunk(retval, ntohs(auth_random->length), 443 auth_random); 444 if (auth_hmacs) 445 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 446 auth_hmacs); 447 if (auth_chunks) 448 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 449 auth_chunks); 450 } 451 452 /* We need to remove the const qualifier at this point. */ 453 retval->asoc = (struct sctp_association *) asoc; 454 455 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 456 * 457 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 458 * HEARTBEAT ACK, * etc.) to the same destination transport 459 * address from which it received the DATA or control chunk 460 * to which it is replying. 461 * 462 * [INIT ACK back to where the INIT came from.] 463 */ 464 if (chunk) 465 retval->transport = chunk->transport; 466 467 nomem_chunk: 468 kfree(cookie); 469 nomem_cookie: 470 kfree(addrs.v); 471 return retval; 472 } 473 474 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10): 475 * 476 * This chunk is used only during the initialization of an association. 477 * It is sent by the initiator of an association to its peer to complete 478 * the initialization process. This chunk MUST precede any DATA chunk 479 * sent within the association, but MAY be bundled with one or more DATA 480 * chunks in the same packet. 481 * 482 * 0 1 2 3 483 * 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 1 484 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 485 * | Type = 10 |Chunk Flags | Length | 486 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 487 * / Cookie / 488 * \ \ 489 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 490 * 491 * Chunk Flags: 8 bit 492 * 493 * Set to zero on transmit and ignored on receipt. 494 * 495 * Length: 16 bits (unsigned integer) 496 * 497 * Set to the size of the chunk in bytes, including the 4 bytes of 498 * the chunk header and the size of the Cookie. 499 * 500 * Cookie: variable size 501 * 502 * This field must contain the exact cookie received in the 503 * State Cookie parameter from the previous INIT ACK. 504 * 505 * An implementation SHOULD make the cookie as small as possible 506 * to insure interoperability. 507 */ 508 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, 509 const struct sctp_chunk *chunk) 510 { 511 struct sctp_chunk *retval; 512 void *cookie; 513 int cookie_len; 514 515 cookie = asoc->peer.cookie; 516 cookie_len = asoc->peer.cookie_len; 517 518 /* Build a cookie echo chunk. */ 519 retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ECHO, 0, cookie_len); 520 if (!retval) 521 goto nodata; 522 retval->subh.cookie_hdr = 523 sctp_addto_chunk(retval, cookie_len, cookie); 524 525 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 526 * 527 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 528 * HEARTBEAT ACK, * etc.) to the same destination transport 529 * address from which it * received the DATA or control chunk 530 * to which it is replying. 531 * 532 * [COOKIE ECHO back to where the INIT ACK came from.] 533 */ 534 if (chunk) 535 retval->transport = chunk->transport; 536 537 nodata: 538 return retval; 539 } 540 541 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11): 542 * 543 * This chunk is used only during the initialization of an 544 * association. It is used to acknowledge the receipt of a COOKIE 545 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent 546 * within the association, but MAY be bundled with one or more DATA 547 * chunks or SACK chunk in the same SCTP packet. 548 * 549 * 0 1 2 3 550 * 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 1 551 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 552 * | Type = 11 |Chunk Flags | Length = 4 | 553 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 554 * 555 * Chunk Flags: 8 bits 556 * 557 * Set to zero on transmit and ignored on receipt. 558 */ 559 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, 560 const struct sctp_chunk *chunk) 561 { 562 struct sctp_chunk *retval; 563 564 retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ACK, 0, 0); 565 566 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 567 * 568 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 569 * HEARTBEAT ACK, * etc.) to the same destination transport 570 * address from which it * received the DATA or control chunk 571 * to which it is replying. 572 * 573 * [COOKIE ACK back to where the COOKIE ECHO came from.] 574 */ 575 if (retval && chunk) 576 retval->transport = chunk->transport; 577 578 return retval; 579 } 580 581 /* 582 * Appendix A: Explicit Congestion Notification: 583 * CWR: 584 * 585 * RFC 2481 details a specific bit for a sender to send in the header of 586 * its next outbound TCP segment to indicate to its peer that it has 587 * reduced its congestion window. This is termed the CWR bit. For 588 * SCTP the same indication is made by including the CWR chunk. 589 * This chunk contains one data element, i.e. the TSN number that 590 * was sent in the ECNE chunk. This element represents the lowest 591 * TSN number in the datagram that was originally marked with the 592 * CE bit. 593 * 594 * 0 1 2 3 595 * 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 1 596 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 597 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 | 598 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 599 * | Lowest TSN Number | 600 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 601 * 602 * Note: The CWR is considered a Control chunk. 603 */ 604 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, 605 const __u32 lowest_tsn, 606 const struct sctp_chunk *chunk) 607 { 608 struct sctp_chunk *retval; 609 sctp_cwrhdr_t cwr; 610 611 cwr.lowest_tsn = htonl(lowest_tsn); 612 retval = sctp_make_chunk(asoc, SCTP_CID_ECN_CWR, 0, 613 sizeof(sctp_cwrhdr_t)); 614 615 if (!retval) 616 goto nodata; 617 618 retval->subh.ecn_cwr_hdr = 619 sctp_addto_chunk(retval, sizeof(cwr), &cwr); 620 621 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 622 * 623 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 624 * HEARTBEAT ACK, * etc.) to the same destination transport 625 * address from which it * received the DATA or control chunk 626 * to which it is replying. 627 * 628 * [Report a reduced congestion window back to where the ECNE 629 * came from.] 630 */ 631 if (chunk) 632 retval->transport = chunk->transport; 633 634 nodata: 635 return retval; 636 } 637 638 /* Make an ECNE chunk. This is a congestion experienced report. */ 639 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, 640 const __u32 lowest_tsn) 641 { 642 struct sctp_chunk *retval; 643 sctp_ecnehdr_t ecne; 644 645 ecne.lowest_tsn = htonl(lowest_tsn); 646 retval = sctp_make_chunk(asoc, SCTP_CID_ECN_ECNE, 0, 647 sizeof(sctp_ecnehdr_t)); 648 if (!retval) 649 goto nodata; 650 retval->subh.ecne_hdr = 651 sctp_addto_chunk(retval, sizeof(ecne), &ecne); 652 653 nodata: 654 return retval; 655 } 656 657 /* Make a DATA chunk for the given association from the provided 658 * parameters. However, do not populate the data payload. 659 */ 660 struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc, 661 const struct sctp_sndrcvinfo *sinfo, 662 int data_len, __u8 flags, __u16 ssn) 663 { 664 struct sctp_chunk *retval; 665 struct sctp_datahdr dp; 666 int chunk_len; 667 668 /* We assign the TSN as LATE as possible, not here when 669 * creating the chunk. 670 */ 671 dp.tsn = 0; 672 dp.stream = htons(sinfo->sinfo_stream); 673 dp.ppid = sinfo->sinfo_ppid; 674 675 /* Set the flags for an unordered send. */ 676 if (sinfo->sinfo_flags & SCTP_UNORDERED) { 677 flags |= SCTP_DATA_UNORDERED; 678 dp.ssn = 0; 679 } else 680 dp.ssn = htons(ssn); 681 682 chunk_len = sizeof(dp) + data_len; 683 retval = sctp_make_chunk(asoc, SCTP_CID_DATA, flags, chunk_len); 684 if (!retval) 685 goto nodata; 686 687 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp); 688 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo)); 689 690 nodata: 691 return retval; 692 } 693 694 /* Create a selective ackowledgement (SACK) for the given 695 * association. This reports on which TSN's we've seen to date, 696 * including duplicates and gaps. 697 */ 698 struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc) 699 { 700 struct sctp_chunk *retval; 701 struct sctp_sackhdr sack; 702 int len; 703 __u32 ctsn; 704 __u16 num_gabs, num_dup_tsns; 705 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; 706 707 ctsn = sctp_tsnmap_get_ctsn(map); 708 SCTP_DEBUG_PRINTK("sackCTSNAck sent: 0x%x.\n", ctsn); 709 710 /* How much room is needed in the chunk? */ 711 num_gabs = sctp_tsnmap_num_gabs(map); 712 num_dup_tsns = sctp_tsnmap_num_dups(map); 713 714 /* Initialize the SACK header. */ 715 sack.cum_tsn_ack = htonl(ctsn); 716 sack.a_rwnd = htonl(asoc->a_rwnd); 717 sack.num_gap_ack_blocks = htons(num_gabs); 718 sack.num_dup_tsns = htons(num_dup_tsns); 719 720 len = sizeof(sack) 721 + sizeof(struct sctp_gap_ack_block) * num_gabs 722 + sizeof(__u32) * num_dup_tsns; 723 724 /* Create the chunk. */ 725 retval = sctp_make_chunk(asoc, SCTP_CID_SACK, 0, len); 726 if (!retval) 727 goto nodata; 728 729 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 730 * 731 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 732 * HEARTBEAT ACK, etc.) to the same destination transport 733 * address from which it received the DATA or control chunk to 734 * which it is replying. This rule should also be followed if 735 * the endpoint is bundling DATA chunks together with the 736 * reply chunk. 737 * 738 * However, when acknowledging multiple DATA chunks received 739 * in packets from different source addresses in a single 740 * SACK, the SACK chunk may be transmitted to one of the 741 * destination transport addresses from which the DATA or 742 * control chunks being acknowledged were received. 743 * 744 * [BUG: We do not implement the following paragraph. 745 * Perhaps we should remember the last transport we used for a 746 * SACK and avoid that (if possible) if we have seen any 747 * duplicates. --piggy] 748 * 749 * When a receiver of a duplicate DATA chunk sends a SACK to a 750 * multi- homed endpoint it MAY be beneficial to vary the 751 * destination address and not use the source address of the 752 * DATA chunk. The reason being that receiving a duplicate 753 * from a multi-homed endpoint might indicate that the return 754 * path (as specified in the source address of the DATA chunk) 755 * for the SACK is broken. 756 * 757 * [Send to the address from which we last received a DATA chunk.] 758 */ 759 retval->transport = asoc->peer.last_data_from; 760 761 retval->subh.sack_hdr = 762 sctp_addto_chunk(retval, sizeof(sack), &sack); 763 764 /* Add the gap ack block information. */ 765 if (num_gabs) 766 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, 767 sctp_tsnmap_get_gabs(map)); 768 769 /* Add the duplicate TSN information. */ 770 if (num_dup_tsns) 771 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, 772 sctp_tsnmap_get_dups(map)); 773 774 nodata: 775 return retval; 776 } 777 778 /* Make a SHUTDOWN chunk. */ 779 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 780 const struct sctp_chunk *chunk) 781 { 782 struct sctp_chunk *retval; 783 sctp_shutdownhdr_t shut; 784 __u32 ctsn; 785 786 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 787 shut.cum_tsn_ack = htonl(ctsn); 788 789 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN, 0, 790 sizeof(sctp_shutdownhdr_t)); 791 if (!retval) 792 goto nodata; 793 794 retval->subh.shutdown_hdr = 795 sctp_addto_chunk(retval, sizeof(shut), &shut); 796 797 if (chunk) 798 retval->transport = chunk->transport; 799 nodata: 800 return retval; 801 } 802 803 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 804 const struct sctp_chunk *chunk) 805 { 806 struct sctp_chunk *retval; 807 808 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0); 809 810 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 811 * 812 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 813 * HEARTBEAT ACK, * etc.) to the same destination transport 814 * address from which it * received the DATA or control chunk 815 * to which it is replying. 816 * 817 * [ACK back to where the SHUTDOWN came from.] 818 */ 819 if (retval && chunk) 820 retval->transport = chunk->transport; 821 822 return retval; 823 } 824 825 struct sctp_chunk *sctp_make_shutdown_complete( 826 const struct sctp_association *asoc, 827 const struct sctp_chunk *chunk) 828 { 829 struct sctp_chunk *retval; 830 __u8 flags = 0; 831 832 /* Set the T-bit if we have no association (vtag will be 833 * reflected) 834 */ 835 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; 836 837 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0); 838 839 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 840 * 841 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 842 * HEARTBEAT ACK, * etc.) to the same destination transport 843 * address from which it * received the DATA or control chunk 844 * to which it is replying. 845 * 846 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK 847 * came from.] 848 */ 849 if (retval && chunk) 850 retval->transport = chunk->transport; 851 852 return retval; 853 } 854 855 /* Create an ABORT. Note that we set the T bit if we have no 856 * association, except when responding to an INIT (sctpimpguide 2.41). 857 */ 858 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 859 const struct sctp_chunk *chunk, 860 const size_t hint) 861 { 862 struct sctp_chunk *retval; 863 __u8 flags = 0; 864 865 /* Set the T-bit if we have no association and 'chunk' is not 866 * an INIT (vtag will be reflected). 867 */ 868 if (!asoc) { 869 if (chunk && chunk->chunk_hdr && 870 chunk->chunk_hdr->type == SCTP_CID_INIT) 871 flags = 0; 872 else 873 flags = SCTP_CHUNK_FLAG_T; 874 } 875 876 retval = sctp_make_chunk(asoc, SCTP_CID_ABORT, flags, hint); 877 878 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 879 * 880 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 881 * HEARTBEAT ACK, * etc.) to the same destination transport 882 * address from which it * received the DATA or control chunk 883 * to which it is replying. 884 * 885 * [ABORT back to where the offender came from.] 886 */ 887 if (retval && chunk) 888 retval->transport = chunk->transport; 889 890 return retval; 891 } 892 893 /* Helper to create ABORT with a NO_USER_DATA error. */ 894 struct sctp_chunk *sctp_make_abort_no_data( 895 const struct sctp_association *asoc, 896 const struct sctp_chunk *chunk, __u32 tsn) 897 { 898 struct sctp_chunk *retval; 899 __be32 payload; 900 901 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) 902 + sizeof(tsn)); 903 904 if (!retval) 905 goto no_mem; 906 907 /* Put the tsn back into network byte order. */ 908 payload = htonl(tsn); 909 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload)); 910 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload); 911 912 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 913 * 914 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 915 * HEARTBEAT ACK, * etc.) to the same destination transport 916 * address from which it * received the DATA or control chunk 917 * to which it is replying. 918 * 919 * [ABORT back to where the offender came from.] 920 */ 921 if (chunk) 922 retval->transport = chunk->transport; 923 924 no_mem: 925 return retval; 926 } 927 928 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ 929 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 930 const struct msghdr *msg, 931 size_t paylen) 932 { 933 struct sctp_chunk *retval; 934 void *payload = NULL; 935 int err; 936 937 retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen); 938 if (!retval) 939 goto err_chunk; 940 941 if (paylen) { 942 /* Put the msg_iov together into payload. */ 943 payload = kmalloc(paylen, GFP_KERNEL); 944 if (!payload) 945 goto err_payload; 946 947 err = memcpy_fromiovec(payload, msg->msg_iov, paylen); 948 if (err < 0) 949 goto err_copy; 950 } 951 952 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); 953 sctp_addto_chunk(retval, paylen, payload); 954 955 if (paylen) 956 kfree(payload); 957 958 return retval; 959 960 err_copy: 961 kfree(payload); 962 err_payload: 963 sctp_chunk_free(retval); 964 retval = NULL; 965 err_chunk: 966 return retval; 967 } 968 969 /* Append bytes to the end of a parameter. Will panic if chunk is not big 970 * enough. 971 */ 972 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 973 const void *data) 974 { 975 void *target; 976 int chunklen = ntohs(chunk->chunk_hdr->length); 977 978 target = skb_put(chunk->skb, len); 979 980 memcpy(target, data, len); 981 982 /* Adjust the chunk length field. */ 983 chunk->chunk_hdr->length = htons(chunklen + len); 984 chunk->chunk_end = skb_tail_pointer(chunk->skb); 985 986 return target; 987 } 988 989 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ 990 struct sctp_chunk *sctp_make_abort_violation( 991 const struct sctp_association *asoc, 992 const struct sctp_chunk *chunk, 993 const __u8 *payload, 994 const size_t paylen) 995 { 996 struct sctp_chunk *retval; 997 struct sctp_paramhdr phdr; 998 999 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen 1000 + sizeof(sctp_paramhdr_t)); 1001 if (!retval) 1002 goto end; 1003 1004 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen 1005 + sizeof(sctp_paramhdr_t)); 1006 1007 phdr.type = htons(chunk->chunk_hdr->type); 1008 phdr.length = chunk->chunk_hdr->length; 1009 sctp_addto_chunk(retval, paylen, payload); 1010 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr); 1011 1012 end: 1013 return retval; 1014 } 1015 1016 /* Make a HEARTBEAT chunk. */ 1017 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1018 const struct sctp_transport *transport, 1019 const void *payload, const size_t paylen) 1020 { 1021 struct sctp_chunk *retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT, 1022 0, paylen); 1023 1024 if (!retval) 1025 goto nodata; 1026 1027 /* Cast away the 'const', as this is just telling the chunk 1028 * what transport it belongs to. 1029 */ 1030 retval->transport = (struct sctp_transport *) transport; 1031 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1032 1033 nodata: 1034 return retval; 1035 } 1036 1037 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1038 const struct sctp_chunk *chunk, 1039 const void *payload, const size_t paylen) 1040 { 1041 struct sctp_chunk *retval; 1042 1043 retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen); 1044 if (!retval) 1045 goto nodata; 1046 1047 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1048 1049 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1050 * 1051 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1052 * HEARTBEAT ACK, * etc.) to the same destination transport 1053 * address from which it * received the DATA or control chunk 1054 * to which it is replying. 1055 * 1056 * [HBACK back to where the HEARTBEAT came from.] 1057 */ 1058 if (chunk) 1059 retval->transport = chunk->transport; 1060 1061 nodata: 1062 return retval; 1063 } 1064 1065 /* Create an Operation Error chunk with the specified space reserved. 1066 * This routine can be used for containing multiple causes in the chunk. 1067 */ 1068 static struct sctp_chunk *sctp_make_op_error_space( 1069 const struct sctp_association *asoc, 1070 const struct sctp_chunk *chunk, 1071 size_t size) 1072 { 1073 struct sctp_chunk *retval; 1074 1075 retval = sctp_make_chunk(asoc, SCTP_CID_ERROR, 0, 1076 sizeof(sctp_errhdr_t) + size); 1077 if (!retval) 1078 goto nodata; 1079 1080 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1081 * 1082 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1083 * HEARTBEAT ACK, etc.) to the same destination transport 1084 * address from which it received the DATA or control chunk 1085 * to which it is replying. 1086 * 1087 */ 1088 if (chunk) 1089 retval->transport = chunk->transport; 1090 1091 nodata: 1092 return retval; 1093 } 1094 1095 /* Create an Operation Error chunk. */ 1096 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1097 const struct sctp_chunk *chunk, 1098 __be16 cause_code, const void *payload, 1099 size_t paylen) 1100 { 1101 struct sctp_chunk *retval; 1102 1103 retval = sctp_make_op_error_space(asoc, chunk, paylen); 1104 if (!retval) 1105 goto nodata; 1106 1107 sctp_init_cause(retval, cause_code, paylen); 1108 sctp_addto_chunk(retval, paylen, payload); 1109 1110 nodata: 1111 return retval; 1112 } 1113 1114 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc) 1115 { 1116 struct sctp_chunk *retval; 1117 struct sctp_hmac *hmac_desc; 1118 struct sctp_authhdr auth_hdr; 1119 __u8 *hmac; 1120 1121 /* Get the first hmac that the peer told us to use */ 1122 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1123 if (unlikely(!hmac_desc)) 1124 return NULL; 1125 1126 retval = sctp_make_chunk(asoc, SCTP_CID_AUTH, 0, 1127 hmac_desc->hmac_len + sizeof(sctp_authhdr_t)); 1128 if (!retval) 1129 return NULL; 1130 1131 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1132 auth_hdr.shkey_id = htons(asoc->active_key_id); 1133 1134 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t), 1135 &auth_hdr); 1136 1137 hmac = skb_put(retval->skb, hmac_desc->hmac_len); 1138 memset(hmac, 0, hmac_desc->hmac_len); 1139 1140 /* Adjust the chunk header to include the empty MAC */ 1141 retval->chunk_hdr->length = 1142 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1143 retval->chunk_end = skb_tail_pointer(retval->skb); 1144 1145 return retval; 1146 } 1147 1148 1149 /******************************************************************** 1150 * 2nd Level Abstractions 1151 ********************************************************************/ 1152 1153 /* Turn an skb into a chunk. 1154 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1155 */ 1156 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1157 const struct sctp_association *asoc, 1158 struct sock *sk) 1159 { 1160 struct sctp_chunk *retval; 1161 1162 retval = kmem_cache_zalloc(sctp_chunk_cachep, GFP_ATOMIC); 1163 1164 if (!retval) 1165 goto nodata; 1166 1167 if (!sk) { 1168 SCTP_DEBUG_PRINTK("chunkifying skb %p w/o an sk\n", skb); 1169 } 1170 1171 INIT_LIST_HEAD(&retval->list); 1172 retval->skb = skb; 1173 retval->asoc = (struct sctp_association *)asoc; 1174 retval->resent = 0; 1175 retval->has_tsn = 0; 1176 retval->has_ssn = 0; 1177 retval->rtt_in_progress = 0; 1178 retval->sent_at = 0; 1179 retval->singleton = 1; 1180 retval->end_of_packet = 0; 1181 retval->ecn_ce_done = 0; 1182 retval->pdiscard = 0; 1183 1184 /* sctpimpguide-05.txt Section 2.8.2 1185 * M1) Each time a new DATA chunk is transmitted 1186 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1187 * 'TSN.Missing.Report' count will be used to determine missing chunks 1188 * and when to fast retransmit. 1189 */ 1190 retval->tsn_missing_report = 0; 1191 retval->tsn_gap_acked = 0; 1192 retval->fast_retransmit = 0; 1193 1194 /* If this is a fragmented message, track all fragments 1195 * of the message (for SEND_FAILED). 1196 */ 1197 retval->msg = NULL; 1198 1199 /* Polish the bead hole. */ 1200 INIT_LIST_HEAD(&retval->transmitted_list); 1201 INIT_LIST_HEAD(&retval->frag_list); 1202 SCTP_DBG_OBJCNT_INC(chunk); 1203 atomic_set(&retval->refcnt, 1); 1204 1205 nodata: 1206 return retval; 1207 } 1208 1209 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1210 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1211 union sctp_addr *dest) 1212 { 1213 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1214 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1215 } 1216 1217 /* Extract the source address from a chunk. */ 1218 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1219 { 1220 /* If we have a known transport, use that. */ 1221 if (chunk->transport) { 1222 return &chunk->transport->ipaddr; 1223 } else { 1224 /* Otherwise, extract it from the IP header. */ 1225 return &chunk->source; 1226 } 1227 } 1228 1229 /* Create a new chunk, setting the type and flags headers from the 1230 * arguments, reserving enough space for a 'paylen' byte payload. 1231 */ 1232 SCTP_STATIC 1233 struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc, 1234 __u8 type, __u8 flags, int paylen) 1235 { 1236 struct sctp_chunk *retval; 1237 sctp_chunkhdr_t *chunk_hdr; 1238 struct sk_buff *skb; 1239 struct sock *sk; 1240 1241 /* No need to allocate LL here, as this is only a chunk. */ 1242 skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen), 1243 GFP_ATOMIC); 1244 if (!skb) 1245 goto nodata; 1246 1247 /* Make room for the chunk header. */ 1248 chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t)); 1249 chunk_hdr->type = type; 1250 chunk_hdr->flags = flags; 1251 chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t)); 1252 1253 sk = asoc ? asoc->base.sk : NULL; 1254 retval = sctp_chunkify(skb, asoc, sk); 1255 if (!retval) { 1256 kfree_skb(skb); 1257 goto nodata; 1258 } 1259 1260 retval->chunk_hdr = chunk_hdr; 1261 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr); 1262 1263 /* Determine if the chunk needs to be authenticated */ 1264 if (sctp_auth_send_cid(type, asoc)) 1265 retval->auth = 1; 1266 1267 /* Set the skb to the belonging sock for accounting. */ 1268 skb->sk = sk; 1269 1270 return retval; 1271 nodata: 1272 return NULL; 1273 } 1274 1275 1276 /* Release the memory occupied by a chunk. */ 1277 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1278 { 1279 /* Free the chunk skb data and the SCTP_chunk stub itself. */ 1280 dev_kfree_skb(chunk->skb); 1281 1282 SCTP_DBG_OBJCNT_DEC(chunk); 1283 kmem_cache_free(sctp_chunk_cachep, chunk); 1284 } 1285 1286 /* Possibly, free the chunk. */ 1287 void sctp_chunk_free(struct sctp_chunk *chunk) 1288 { 1289 BUG_ON(!list_empty(&chunk->list)); 1290 list_del_init(&chunk->transmitted_list); 1291 1292 /* Release our reference on the message tracker. */ 1293 if (chunk->msg) 1294 sctp_datamsg_put(chunk->msg); 1295 1296 sctp_chunk_put(chunk); 1297 } 1298 1299 /* Grab a reference to the chunk. */ 1300 void sctp_chunk_hold(struct sctp_chunk *ch) 1301 { 1302 atomic_inc(&ch->refcnt); 1303 } 1304 1305 /* Release a reference to the chunk. */ 1306 void sctp_chunk_put(struct sctp_chunk *ch) 1307 { 1308 if (atomic_dec_and_test(&ch->refcnt)) 1309 sctp_chunk_destroy(ch); 1310 } 1311 1312 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1313 * enough. 1314 */ 1315 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1316 { 1317 void *target; 1318 void *padding; 1319 int chunklen = ntohs(chunk->chunk_hdr->length); 1320 int padlen = WORD_ROUND(chunklen) - chunklen; 1321 1322 padding = skb_put(chunk->skb, padlen); 1323 target = skb_put(chunk->skb, len); 1324 1325 memset(padding, 0, padlen); 1326 memcpy(target, data, len); 1327 1328 /* Adjust the chunk length field. */ 1329 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1330 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1331 1332 return target; 1333 } 1334 1335 /* Append bytes from user space to the end of a chunk. Will panic if 1336 * chunk is not big enough. 1337 * Returns a kernel err value. 1338 */ 1339 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len, 1340 struct iovec *data) 1341 { 1342 __u8 *target; 1343 int err = 0; 1344 1345 /* Make room in chunk for data. */ 1346 target = skb_put(chunk->skb, len); 1347 1348 /* Copy data (whole iovec) into chunk */ 1349 if ((err = memcpy_fromiovecend(target, data, off, len))) 1350 goto out; 1351 1352 /* Adjust the chunk length field. */ 1353 chunk->chunk_hdr->length = 1354 htons(ntohs(chunk->chunk_hdr->length) + len); 1355 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1356 1357 out: 1358 return err; 1359 } 1360 1361 /* Helper function to assign a TSN if needed. This assumes that both 1362 * the data_hdr and association have already been assigned. 1363 */ 1364 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1365 { 1366 struct sctp_datamsg *msg; 1367 struct sctp_chunk *lchunk; 1368 struct sctp_stream *stream; 1369 __u16 ssn; 1370 __u16 sid; 1371 1372 if (chunk->has_ssn) 1373 return; 1374 1375 /* All fragments will be on the same stream */ 1376 sid = ntohs(chunk->subh.data_hdr->stream); 1377 stream = &chunk->asoc->ssnmap->out; 1378 1379 /* Now assign the sequence number to the entire message. 1380 * All fragments must have the same stream sequence number. 1381 */ 1382 msg = chunk->msg; 1383 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1384 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1385 ssn = 0; 1386 } else { 1387 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1388 ssn = sctp_ssn_next(stream, sid); 1389 else 1390 ssn = sctp_ssn_peek(stream, sid); 1391 } 1392 1393 lchunk->subh.data_hdr->ssn = htons(ssn); 1394 lchunk->has_ssn = 1; 1395 } 1396 } 1397 1398 /* Helper function to assign a TSN if needed. This assumes that both 1399 * the data_hdr and association have already been assigned. 1400 */ 1401 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1402 { 1403 if (!chunk->has_tsn) { 1404 /* This is the last possible instant to 1405 * assign a TSN. 1406 */ 1407 chunk->subh.data_hdr->tsn = 1408 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1409 chunk->has_tsn = 1; 1410 } 1411 } 1412 1413 /* Create a CLOSED association to use with an incoming packet. */ 1414 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1415 struct sctp_chunk *chunk, 1416 gfp_t gfp) 1417 { 1418 struct sctp_association *asoc; 1419 struct sk_buff *skb; 1420 sctp_scope_t scope; 1421 struct sctp_af *af; 1422 1423 /* Create the bare association. */ 1424 scope = sctp_scope(sctp_source(chunk)); 1425 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1426 if (!asoc) 1427 goto nodata; 1428 asoc->temp = 1; 1429 skb = chunk->skb; 1430 /* Create an entry for the source address of the packet. */ 1431 af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version)); 1432 if (unlikely(!af)) 1433 goto fail; 1434 af->from_skb(&asoc->c.peer_addr, skb, 1); 1435 nodata: 1436 return asoc; 1437 1438 fail: 1439 sctp_association_free(asoc); 1440 return NULL; 1441 } 1442 1443 /* Build a cookie representing asoc. 1444 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1445 */ 1446 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, 1447 const struct sctp_association *asoc, 1448 const struct sctp_chunk *init_chunk, 1449 int *cookie_len, 1450 const __u8 *raw_addrs, int addrs_len) 1451 { 1452 sctp_cookie_param_t *retval; 1453 struct sctp_signed_cookie *cookie; 1454 struct scatterlist sg; 1455 int headersize, bodysize; 1456 unsigned int keylen; 1457 char *key; 1458 1459 /* Header size is static data prior to the actual cookie, including 1460 * any padding. 1461 */ 1462 headersize = sizeof(sctp_paramhdr_t) + 1463 (sizeof(struct sctp_signed_cookie) - 1464 sizeof(struct sctp_cookie)); 1465 bodysize = sizeof(struct sctp_cookie) 1466 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1467 1468 /* Pad out the cookie to a multiple to make the signature 1469 * functions simpler to write. 1470 */ 1471 if (bodysize % SCTP_COOKIE_MULTIPLE) 1472 bodysize += SCTP_COOKIE_MULTIPLE 1473 - (bodysize % SCTP_COOKIE_MULTIPLE); 1474 *cookie_len = headersize + bodysize; 1475 1476 /* Clear this memory since we are sending this data structure 1477 * out on the network. 1478 */ 1479 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1480 if (!retval) 1481 goto nodata; 1482 1483 cookie = (struct sctp_signed_cookie *) retval->body; 1484 1485 /* Set up the parameter header. */ 1486 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1487 retval->p.length = htons(*cookie_len); 1488 1489 /* Copy the cookie part of the association itself. */ 1490 cookie->c = asoc->c; 1491 /* Save the raw address list length in the cookie. */ 1492 cookie->c.raw_addr_list_len = addrs_len; 1493 1494 /* Remember PR-SCTP capability. */ 1495 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1496 1497 /* Save adaptation indication in the cookie. */ 1498 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1499 1500 /* Set an expiration time for the cookie. */ 1501 do_gettimeofday(&cookie->c.expiration); 1502 TIMEVAL_ADD(asoc->cookie_life, cookie->c.expiration); 1503 1504 /* Copy the peer's init packet. */ 1505 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr, 1506 ntohs(init_chunk->chunk_hdr->length)); 1507 1508 /* Copy the raw local address list of the association. */ 1509 memcpy((__u8 *)&cookie->c.peer_init[0] + 1510 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1511 1512 if (sctp_sk(ep->base.sk)->hmac) { 1513 struct hash_desc desc; 1514 1515 /* Sign the message. */ 1516 sg_init_table(&sg, 1); 1517 sg_set_page(&sg, virt_to_page(&cookie->c)); 1518 sg.offset = (unsigned long)(&cookie->c) % PAGE_SIZE; 1519 sg.length = bodysize; 1520 keylen = SCTP_SECRET_SIZE; 1521 key = (char *)ep->secret_key[ep->current_key]; 1522 desc.tfm = sctp_sk(ep->base.sk)->hmac; 1523 desc.flags = 0; 1524 1525 if (crypto_hash_setkey(desc.tfm, key, keylen) || 1526 crypto_hash_digest(&desc, &sg, bodysize, cookie->signature)) 1527 goto free_cookie; 1528 } 1529 1530 return retval; 1531 1532 free_cookie: 1533 kfree(retval); 1534 nodata: 1535 *cookie_len = 0; 1536 return NULL; 1537 } 1538 1539 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1540 struct sctp_association *sctp_unpack_cookie( 1541 const struct sctp_endpoint *ep, 1542 const struct sctp_association *asoc, 1543 struct sctp_chunk *chunk, gfp_t gfp, 1544 int *error, struct sctp_chunk **errp) 1545 { 1546 struct sctp_association *retval = NULL; 1547 struct sctp_signed_cookie *cookie; 1548 struct sctp_cookie *bear_cookie; 1549 int headersize, bodysize, fixed_size; 1550 __u8 *digest = ep->digest; 1551 struct scatterlist sg; 1552 unsigned int keylen, len; 1553 char *key; 1554 sctp_scope_t scope; 1555 struct sk_buff *skb = chunk->skb; 1556 struct timeval tv; 1557 struct hash_desc desc; 1558 1559 /* Header size is static data prior to the actual cookie, including 1560 * any padding. 1561 */ 1562 headersize = sizeof(sctp_chunkhdr_t) + 1563 (sizeof(struct sctp_signed_cookie) - 1564 sizeof(struct sctp_cookie)); 1565 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1566 fixed_size = headersize + sizeof(struct sctp_cookie); 1567 1568 /* Verify that the chunk looks like it even has a cookie. 1569 * There must be enough room for our cookie and our peer's 1570 * INIT chunk. 1571 */ 1572 len = ntohs(chunk->chunk_hdr->length); 1573 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1574 goto malformed; 1575 1576 /* Verify that the cookie has been padded out. */ 1577 if (bodysize % SCTP_COOKIE_MULTIPLE) 1578 goto malformed; 1579 1580 /* Process the cookie. */ 1581 cookie = chunk->subh.cookie_hdr; 1582 bear_cookie = &cookie->c; 1583 1584 if (!sctp_sk(ep->base.sk)->hmac) 1585 goto no_hmac; 1586 1587 /* Check the signature. */ 1588 keylen = SCTP_SECRET_SIZE; 1589 sg_init_table(&sg, 1); 1590 sg_set_page(&sg, virt_to_page(bear_cookie)); 1591 sg.offset = (unsigned long)(bear_cookie) % PAGE_SIZE; 1592 sg.length = bodysize; 1593 key = (char *)ep->secret_key[ep->current_key]; 1594 desc.tfm = sctp_sk(ep->base.sk)->hmac; 1595 desc.flags = 0; 1596 1597 memset(digest, 0x00, SCTP_SIGNATURE_SIZE); 1598 if (crypto_hash_setkey(desc.tfm, key, keylen) || 1599 crypto_hash_digest(&desc, &sg, bodysize, digest)) { 1600 *error = -SCTP_IERROR_NOMEM; 1601 goto fail; 1602 } 1603 1604 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1605 /* Try the previous key. */ 1606 key = (char *)ep->secret_key[ep->last_key]; 1607 memset(digest, 0x00, SCTP_SIGNATURE_SIZE); 1608 if (crypto_hash_setkey(desc.tfm, key, keylen) || 1609 crypto_hash_digest(&desc, &sg, bodysize, digest)) { 1610 *error = -SCTP_IERROR_NOMEM; 1611 goto fail; 1612 } 1613 1614 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1615 /* Yikes! Still bad signature! */ 1616 *error = -SCTP_IERROR_BAD_SIG; 1617 goto fail; 1618 } 1619 } 1620 1621 no_hmac: 1622 /* IG Section 2.35.2: 1623 * 3) Compare the port numbers and the verification tag contained 1624 * within the COOKIE ECHO chunk to the actual port numbers and the 1625 * verification tag within the SCTP common header of the received 1626 * packet. If these values do not match the packet MUST be silently 1627 * discarded, 1628 */ 1629 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1630 *error = -SCTP_IERROR_BAD_TAG; 1631 goto fail; 1632 } 1633 1634 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1635 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1636 *error = -SCTP_IERROR_BAD_PORTS; 1637 goto fail; 1638 } 1639 1640 /* Check to see if the cookie is stale. If there is already 1641 * an association, there is no need to check cookie's expiration 1642 * for init collision case of lost COOKIE ACK. 1643 * If skb has been timestamped, then use the stamp, otherwise 1644 * use current time. This introduces a small possibility that 1645 * that a cookie may be considered expired, but his would only slow 1646 * down the new association establishment instead of every packet. 1647 */ 1648 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1649 skb_get_timestamp(skb, &tv); 1650 else 1651 do_gettimeofday(&tv); 1652 1653 if (!asoc && tv_lt(bear_cookie->expiration, tv)) { 1654 /* 1655 * Section 3.3.10.3 Stale Cookie Error (3) 1656 * 1657 * Cause of error 1658 * --------------- 1659 * Stale Cookie Error: Indicates the receipt of a valid State 1660 * Cookie that has expired. 1661 */ 1662 len = ntohs(chunk->chunk_hdr->length); 1663 *errp = sctp_make_op_error_space(asoc, chunk, len); 1664 if (*errp) { 1665 suseconds_t usecs = (tv.tv_sec - 1666 bear_cookie->expiration.tv_sec) * 1000000L + 1667 tv.tv_usec - bear_cookie->expiration.tv_usec; 1668 __be32 n = htonl(usecs); 1669 1670 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE, 1671 sizeof(n)); 1672 sctp_addto_chunk(*errp, sizeof(n), &n); 1673 *error = -SCTP_IERROR_STALE_COOKIE; 1674 } else 1675 *error = -SCTP_IERROR_NOMEM; 1676 1677 goto fail; 1678 } 1679 1680 /* Make a new base association. */ 1681 scope = sctp_scope(sctp_source(chunk)); 1682 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1683 if (!retval) { 1684 *error = -SCTP_IERROR_NOMEM; 1685 goto fail; 1686 } 1687 1688 /* Set up our peer's port number. */ 1689 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1690 1691 /* Populate the association from the cookie. */ 1692 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1693 1694 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1695 GFP_ATOMIC) < 0) { 1696 *error = -SCTP_IERROR_NOMEM; 1697 goto fail; 1698 } 1699 1700 /* Also, add the destination address. */ 1701 if (list_empty(&retval->base.bind_addr.address_list)) { 1702 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1, 1703 GFP_ATOMIC); 1704 } 1705 1706 retval->next_tsn = retval->c.initial_tsn; 1707 retval->ctsn_ack_point = retval->next_tsn - 1; 1708 retval->addip_serial = retval->c.initial_tsn; 1709 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1710 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1711 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1712 1713 /* The INIT stuff will be done by the side effects. */ 1714 return retval; 1715 1716 fail: 1717 if (retval) 1718 sctp_association_free(retval); 1719 1720 return NULL; 1721 1722 malformed: 1723 /* Yikes! The packet is either corrupt or deliberately 1724 * malformed. 1725 */ 1726 *error = -SCTP_IERROR_MALFORMED; 1727 goto fail; 1728 } 1729 1730 /******************************************************************** 1731 * 3rd Level Abstractions 1732 ********************************************************************/ 1733 1734 struct __sctp_missing { 1735 __be32 num_missing; 1736 __be16 type; 1737 } __attribute__((packed)); 1738 1739 /* 1740 * Report a missing mandatory parameter. 1741 */ 1742 static int sctp_process_missing_param(const struct sctp_association *asoc, 1743 sctp_param_t paramtype, 1744 struct sctp_chunk *chunk, 1745 struct sctp_chunk **errp) 1746 { 1747 struct __sctp_missing report; 1748 __u16 len; 1749 1750 len = WORD_ROUND(sizeof(report)); 1751 1752 /* Make an ERROR chunk, preparing enough room for 1753 * returning multiple unknown parameters. 1754 */ 1755 if (!*errp) 1756 *errp = sctp_make_op_error_space(asoc, chunk, len); 1757 1758 if (*errp) { 1759 report.num_missing = htonl(1); 1760 report.type = paramtype; 1761 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1762 sizeof(report)); 1763 sctp_addto_chunk(*errp, sizeof(report), &report); 1764 } 1765 1766 /* Stop processing this chunk. */ 1767 return 0; 1768 } 1769 1770 /* Report an Invalid Mandatory Parameter. */ 1771 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1772 struct sctp_chunk *chunk, 1773 struct sctp_chunk **errp) 1774 { 1775 /* Invalid Mandatory Parameter Error has no payload. */ 1776 1777 if (!*errp) 1778 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1779 1780 if (*errp) 1781 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1782 1783 /* Stop processing this chunk. */ 1784 return 0; 1785 } 1786 1787 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1788 struct sctp_paramhdr *param, 1789 const struct sctp_chunk *chunk, 1790 struct sctp_chunk **errp) 1791 { 1792 char error[] = "The following parameter had invalid length:"; 1793 size_t payload_len = WORD_ROUND(sizeof(error)) + 1794 sizeof(sctp_paramhdr_t); 1795 1796 1797 /* Create an error chunk and fill it in with our payload. */ 1798 if (!*errp) 1799 *errp = sctp_make_op_error_space(asoc, chunk, payload_len); 1800 1801 if (*errp) { 1802 sctp_init_cause(*errp, SCTP_ERROR_PROTO_VIOLATION, 1803 sizeof(error) + sizeof(sctp_paramhdr_t)); 1804 sctp_addto_chunk(*errp, sizeof(error), error); 1805 sctp_addto_param(*errp, sizeof(sctp_paramhdr_t), param); 1806 } 1807 1808 return 0; 1809 } 1810 1811 1812 /* Do not attempt to handle the HOST_NAME parm. However, do 1813 * send back an indicator to the peer. 1814 */ 1815 static int sctp_process_hn_param(const struct sctp_association *asoc, 1816 union sctp_params param, 1817 struct sctp_chunk *chunk, 1818 struct sctp_chunk **errp) 1819 { 1820 __u16 len = ntohs(param.p->length); 1821 1822 /* Make an ERROR chunk. */ 1823 if (!*errp) 1824 *errp = sctp_make_op_error_space(asoc, chunk, len); 1825 1826 if (*errp) { 1827 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len); 1828 sctp_addto_chunk(*errp, len, param.v); 1829 } 1830 1831 /* Stop processing this chunk. */ 1832 return 0; 1833 } 1834 1835 static void sctp_process_ext_param(struct sctp_association *asoc, 1836 union sctp_params param) 1837 { 1838 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 1839 int i; 1840 1841 for (i = 0; i < num_ext; i++) { 1842 switch (param.ext->chunks[i]) { 1843 case SCTP_CID_FWD_TSN: 1844 if (sctp_prsctp_enable && 1845 !asoc->peer.prsctp_capable) 1846 asoc->peer.prsctp_capable = 1; 1847 break; 1848 case SCTP_CID_AUTH: 1849 /* if the peer reports AUTH, assume that he 1850 * supports AUTH. 1851 */ 1852 asoc->peer.auth_capable = 1; 1853 break; 1854 case SCTP_CID_ASCONF: 1855 case SCTP_CID_ASCONF_ACK: 1856 asoc->peer.addip_capable = 1; 1857 break; 1858 default: 1859 break; 1860 } 1861 } 1862 } 1863 1864 /* RFC 3.2.1 & the Implementers Guide 2.2. 1865 * 1866 * The Parameter Types are encoded such that the 1867 * highest-order two bits specify the action that must be 1868 * taken if the processing endpoint does not recognize the 1869 * Parameter Type. 1870 * 1871 * 00 - Stop processing this SCTP chunk and discard it, 1872 * do not process any further chunks within it. 1873 * 1874 * 01 - Stop processing this SCTP chunk and discard it, 1875 * do not process any further chunks within it, and report 1876 * the unrecognized parameter in an 'Unrecognized 1877 * Parameter Type' (in either an ERROR or in the INIT ACK). 1878 * 1879 * 10 - Skip this parameter and continue processing. 1880 * 1881 * 11 - Skip this parameter and continue processing but 1882 * report the unrecognized parameter in an 1883 * 'Unrecognized Parameter Type' (in either an ERROR or in 1884 * the INIT ACK). 1885 * 1886 * Return value: 1887 * 0 - discard the chunk 1888 * 1 - continue with the chunk 1889 */ 1890 static int sctp_process_unk_param(const struct sctp_association *asoc, 1891 union sctp_params param, 1892 struct sctp_chunk *chunk, 1893 struct sctp_chunk **errp) 1894 { 1895 int retval = 1; 1896 1897 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 1898 case SCTP_PARAM_ACTION_DISCARD: 1899 retval = 0; 1900 break; 1901 case SCTP_PARAM_ACTION_DISCARD_ERR: 1902 retval = 0; 1903 /* Make an ERROR chunk, preparing enough room for 1904 * returning multiple unknown parameters. 1905 */ 1906 if (NULL == *errp) 1907 *errp = sctp_make_op_error_space(asoc, chunk, 1908 ntohs(chunk->chunk_hdr->length)); 1909 1910 if (*errp) { 1911 sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, 1912 WORD_ROUND(ntohs(param.p->length))); 1913 sctp_addto_chunk(*errp, 1914 WORD_ROUND(ntohs(param.p->length)), 1915 param.v); 1916 } 1917 1918 break; 1919 case SCTP_PARAM_ACTION_SKIP: 1920 break; 1921 case SCTP_PARAM_ACTION_SKIP_ERR: 1922 /* Make an ERROR chunk, preparing enough room for 1923 * returning multiple unknown parameters. 1924 */ 1925 if (NULL == *errp) 1926 *errp = sctp_make_op_error_space(asoc, chunk, 1927 ntohs(chunk->chunk_hdr->length)); 1928 1929 if (*errp) { 1930 sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, 1931 WORD_ROUND(ntohs(param.p->length))); 1932 sctp_addto_chunk(*errp, 1933 WORD_ROUND(ntohs(param.p->length)), 1934 param.v); 1935 } else { 1936 /* If there is no memory for generating the ERROR 1937 * report as specified, an ABORT will be triggered 1938 * to the peer and the association won't be 1939 * established. 1940 */ 1941 retval = 0; 1942 } 1943 1944 break; 1945 default: 1946 break; 1947 } 1948 1949 return retval; 1950 } 1951 1952 /* Find unrecognized parameters in the chunk. 1953 * Return values: 1954 * 0 - discard the chunk 1955 * 1 - continue with the chunk 1956 */ 1957 static int sctp_verify_param(const struct sctp_association *asoc, 1958 union sctp_params param, 1959 sctp_cid_t cid, 1960 struct sctp_chunk *chunk, 1961 struct sctp_chunk **err_chunk) 1962 { 1963 int retval = 1; 1964 1965 /* FIXME - This routine is not looking at each parameter per the 1966 * chunk type, i.e., unrecognized parameters should be further 1967 * identified based on the chunk id. 1968 */ 1969 1970 switch (param.p->type) { 1971 case SCTP_PARAM_IPV4_ADDRESS: 1972 case SCTP_PARAM_IPV6_ADDRESS: 1973 case SCTP_PARAM_COOKIE_PRESERVATIVE: 1974 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 1975 case SCTP_PARAM_STATE_COOKIE: 1976 case SCTP_PARAM_HEARTBEAT_INFO: 1977 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 1978 case SCTP_PARAM_ECN_CAPABLE: 1979 case SCTP_PARAM_ADAPTATION_LAYER_IND: 1980 case SCTP_PARAM_SUPPORTED_EXT: 1981 break; 1982 1983 case SCTP_PARAM_HOST_NAME_ADDRESS: 1984 /* Tell the peer, we won't support this param. */ 1985 return sctp_process_hn_param(asoc, param, chunk, err_chunk); 1986 1987 case SCTP_PARAM_FWD_TSN_SUPPORT: 1988 if (sctp_prsctp_enable) 1989 break; 1990 goto fallthrough; 1991 1992 case SCTP_PARAM_RANDOM: 1993 if (!sctp_auth_enable) 1994 goto fallthrough; 1995 1996 /* SCTP-AUTH: Secion 6.1 1997 * If the random number is not 32 byte long the association 1998 * MUST be aborted. The ABORT chunk SHOULD contain the error 1999 * cause 'Protocol Violation'. 2000 */ 2001 if (SCTP_AUTH_RANDOM_LENGTH != 2002 ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) 2003 return sctp_process_inv_paramlength(asoc, param.p, 2004 chunk, err_chunk); 2005 break; 2006 2007 case SCTP_PARAM_CHUNKS: 2008 if (!sctp_auth_enable) 2009 goto fallthrough; 2010 2011 /* SCTP-AUTH: Section 3.2 2012 * The CHUNKS parameter MUST be included once in the INIT or 2013 * INIT-ACK chunk if the sender wants to receive authenticated 2014 * chunks. Its maximum length is 260 bytes. 2015 */ 2016 if (260 < ntohs(param.p->length)) 2017 return sctp_process_inv_paramlength(asoc, param.p, 2018 chunk, err_chunk); 2019 break; 2020 2021 case SCTP_PARAM_HMAC_ALGO: 2022 if (!sctp_auth_enable) 2023 break; 2024 /* Fall Through */ 2025 fallthrough: 2026 default: 2027 SCTP_DEBUG_PRINTK("Unrecognized param: %d for chunk %d.\n", 2028 ntohs(param.p->type), cid); 2029 return sctp_process_unk_param(asoc, param, chunk, err_chunk); 2030 2031 break; 2032 } 2033 return retval; 2034 } 2035 2036 /* Verify the INIT packet before we process it. */ 2037 int sctp_verify_init(const struct sctp_association *asoc, 2038 sctp_cid_t cid, 2039 sctp_init_chunk_t *peer_init, 2040 struct sctp_chunk *chunk, 2041 struct sctp_chunk **errp) 2042 { 2043 union sctp_params param; 2044 int has_cookie = 0; 2045 2046 /* Verify stream values are non-zero. */ 2047 if ((0 == peer_init->init_hdr.num_outbound_streams) || 2048 (0 == peer_init->init_hdr.num_inbound_streams) || 2049 (0 == peer_init->init_hdr.init_tag) || 2050 (SCTP_DEFAULT_MINWINDOW > ntohl(peer_init->init_hdr.a_rwnd))) { 2051 2052 sctp_process_inv_mandatory(asoc, chunk, errp); 2053 return 0; 2054 } 2055 2056 /* Check for missing mandatory parameters. */ 2057 sctp_walk_params(param, peer_init, init_hdr.params) { 2058 2059 if (SCTP_PARAM_STATE_COOKIE == param.p->type) 2060 has_cookie = 1; 2061 2062 } /* for (loop through all parameters) */ 2063 2064 /* There is a possibility that a parameter length was bad and 2065 * in that case we would have stoped walking the parameters. 2066 * The current param.p would point at the bad one. 2067 * Current consensus on the mailing list is to generate a PROTOCOL 2068 * VIOLATION error. We build the ERROR chunk here and let the normal 2069 * error handling code build and send the packet. 2070 */ 2071 if (param.v != (void*)chunk->chunk_end) { 2072 sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2073 return 0; 2074 } 2075 2076 /* The only missing mandatory param possible today is 2077 * the state cookie for an INIT-ACK chunk. 2078 */ 2079 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) { 2080 sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2081 chunk, errp); 2082 return 0; 2083 } 2084 2085 /* Find unrecognized parameters. */ 2086 2087 sctp_walk_params(param, peer_init, init_hdr.params) { 2088 2089 if (!sctp_verify_param(asoc, param, cid, chunk, errp)) { 2090 if (SCTP_PARAM_HOST_NAME_ADDRESS == param.p->type) 2091 return 0; 2092 else 2093 return 1; 2094 } 2095 2096 } /* for (loop through all parameters) */ 2097 2098 return 1; 2099 } 2100 2101 /* Unpack the parameters in an INIT packet into an association. 2102 * Returns 0 on failure, else success. 2103 * FIXME: This is an association method. 2104 */ 2105 int sctp_process_init(struct sctp_association *asoc, sctp_cid_t cid, 2106 const union sctp_addr *peer_addr, 2107 sctp_init_chunk_t *peer_init, gfp_t gfp) 2108 { 2109 union sctp_params param; 2110 struct sctp_transport *transport; 2111 struct list_head *pos, *temp; 2112 char *cookie; 2113 2114 /* We must include the address that the INIT packet came from. 2115 * This is the only address that matters for an INIT packet. 2116 * When processing a COOKIE ECHO, we retrieve the from address 2117 * of the INIT from the cookie. 2118 */ 2119 2120 /* This implementation defaults to making the first transport 2121 * added as the primary transport. The source address seems to 2122 * be a a better choice than any of the embedded addresses. 2123 */ 2124 if (peer_addr) { 2125 if(!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2126 goto nomem; 2127 } 2128 2129 /* Process the initialization parameters. */ 2130 sctp_walk_params(param, peer_init, init_hdr.params) { 2131 2132 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2133 goto clean_up; 2134 } 2135 2136 /* AUTH: After processing the parameters, make sure that we 2137 * have all the required info to potentially do authentications. 2138 */ 2139 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2140 !asoc->peer.peer_hmacs)) 2141 asoc->peer.auth_capable = 0; 2142 2143 2144 /* If the peer claims support for ADD-IP without support 2145 * for AUTH, disable support for ADD-IP. 2146 */ 2147 if (asoc->peer.addip_capable && !asoc->peer.auth_capable) { 2148 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2149 SCTP_PARAM_DEL_IP | 2150 SCTP_PARAM_SET_PRIMARY); 2151 } 2152 2153 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2154 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2155 transport = list_entry(pos, struct sctp_transport, transports); 2156 if (transport->state == SCTP_UNKNOWN) { 2157 sctp_assoc_rm_peer(asoc, transport); 2158 } 2159 } 2160 2161 /* The fixed INIT headers are always in network byte 2162 * order. 2163 */ 2164 asoc->peer.i.init_tag = 2165 ntohl(peer_init->init_hdr.init_tag); 2166 asoc->peer.i.a_rwnd = 2167 ntohl(peer_init->init_hdr.a_rwnd); 2168 asoc->peer.i.num_outbound_streams = 2169 ntohs(peer_init->init_hdr.num_outbound_streams); 2170 asoc->peer.i.num_inbound_streams = 2171 ntohs(peer_init->init_hdr.num_inbound_streams); 2172 asoc->peer.i.initial_tsn = 2173 ntohl(peer_init->init_hdr.initial_tsn); 2174 2175 /* Apply the upper bounds for output streams based on peer's 2176 * number of inbound streams. 2177 */ 2178 if (asoc->c.sinit_num_ostreams > 2179 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2180 asoc->c.sinit_num_ostreams = 2181 ntohs(peer_init->init_hdr.num_inbound_streams); 2182 } 2183 2184 if (asoc->c.sinit_max_instreams > 2185 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2186 asoc->c.sinit_max_instreams = 2187 ntohs(peer_init->init_hdr.num_outbound_streams); 2188 } 2189 2190 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2191 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2192 2193 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2194 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2195 2196 /* Copy cookie in case we need to resend COOKIE-ECHO. */ 2197 cookie = asoc->peer.cookie; 2198 if (cookie) { 2199 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp); 2200 if (!asoc->peer.cookie) 2201 goto clean_up; 2202 } 2203 2204 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2205 * high (for example, implementations MAY use the size of the receiver 2206 * advertised window). 2207 */ 2208 list_for_each(pos, &asoc->peer.transport_addr_list) { 2209 transport = list_entry(pos, struct sctp_transport, transports); 2210 transport->ssthresh = asoc->peer.i.a_rwnd; 2211 } 2212 2213 /* Set up the TSN tracking pieces. */ 2214 sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE, 2215 asoc->peer.i.initial_tsn); 2216 2217 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2218 * 2219 * The stream sequence number in all the streams shall start 2220 * from 0 when the association is established. Also, when the 2221 * stream sequence number reaches the value 65535 the next 2222 * stream sequence number shall be set to 0. 2223 */ 2224 2225 /* Allocate storage for the negotiated streams if it is not a temporary 2226 * association. 2227 */ 2228 if (!asoc->temp) { 2229 int error; 2230 2231 asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams, 2232 asoc->c.sinit_num_ostreams, gfp); 2233 if (!asoc->ssnmap) 2234 goto clean_up; 2235 2236 error = sctp_assoc_set_id(asoc, gfp); 2237 if (error) 2238 goto clean_up; 2239 } 2240 2241 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2242 * 2243 * When an endpoint has an ASCONF signaled change to be sent to the 2244 * remote endpoint it should do the following: 2245 * ... 2246 * A2) A serial number should be assigned to the Chunk. The serial 2247 * number should be a monotonically increasing number. All serial 2248 * numbers are defined to be initialized at the start of the 2249 * association to the same value as the Initial TSN. 2250 */ 2251 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2252 return 1; 2253 2254 clean_up: 2255 /* Release the transport structures. */ 2256 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2257 transport = list_entry(pos, struct sctp_transport, transports); 2258 list_del_init(pos); 2259 sctp_transport_free(transport); 2260 } 2261 2262 asoc->peer.transport_count = 0; 2263 2264 nomem: 2265 return 0; 2266 } 2267 2268 2269 /* Update asoc with the option described in param. 2270 * 2271 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2272 * 2273 * asoc is the association to update. 2274 * param is the variable length parameter to use for update. 2275 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2276 * If the current packet is an INIT we want to minimize the amount of 2277 * work we do. In particular, we should not build transport 2278 * structures for the addresses. 2279 */ 2280 static int sctp_process_param(struct sctp_association *asoc, 2281 union sctp_params param, 2282 const union sctp_addr *peer_addr, 2283 gfp_t gfp) 2284 { 2285 union sctp_addr addr; 2286 int i; 2287 __u16 sat; 2288 int retval = 1; 2289 sctp_scope_t scope; 2290 time_t stale; 2291 struct sctp_af *af; 2292 2293 /* We maintain all INIT parameters in network byte order all the 2294 * time. This allows us to not worry about whether the parameters 2295 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2296 */ 2297 switch (param.p->type) { 2298 case SCTP_PARAM_IPV6_ADDRESS: 2299 if (PF_INET6 != asoc->base.sk->sk_family) 2300 break; 2301 /* Fall through. */ 2302 case SCTP_PARAM_IPV4_ADDRESS: 2303 af = sctp_get_af_specific(param_type2af(param.p->type)); 2304 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); 2305 scope = sctp_scope(peer_addr); 2306 if (sctp_in_scope(&addr, scope)) 2307 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2308 return 0; 2309 break; 2310 2311 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2312 if (!sctp_cookie_preserve_enable) 2313 break; 2314 2315 stale = ntohl(param.life->lifespan_increment); 2316 2317 /* Suggested Cookie Life span increment's unit is msec, 2318 * (1/1000sec). 2319 */ 2320 asoc->cookie_life.tv_sec += stale / 1000; 2321 asoc->cookie_life.tv_usec += (stale % 1000) * 1000; 2322 break; 2323 2324 case SCTP_PARAM_HOST_NAME_ADDRESS: 2325 SCTP_DEBUG_PRINTK("unimplemented SCTP_HOST_NAME_ADDRESS\n"); 2326 break; 2327 2328 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2329 /* Turn off the default values first so we'll know which 2330 * ones are really set by the peer. 2331 */ 2332 asoc->peer.ipv4_address = 0; 2333 asoc->peer.ipv6_address = 0; 2334 2335 /* Cycle through address types; avoid divide by 0. */ 2336 sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2337 if (sat) 2338 sat /= sizeof(__u16); 2339 2340 for (i = 0; i < sat; ++i) { 2341 switch (param.sat->types[i]) { 2342 case SCTP_PARAM_IPV4_ADDRESS: 2343 asoc->peer.ipv4_address = 1; 2344 break; 2345 2346 case SCTP_PARAM_IPV6_ADDRESS: 2347 asoc->peer.ipv6_address = 1; 2348 break; 2349 2350 case SCTP_PARAM_HOST_NAME_ADDRESS: 2351 asoc->peer.hostname_address = 1; 2352 break; 2353 2354 default: /* Just ignore anything else. */ 2355 break; 2356 } 2357 } 2358 break; 2359 2360 case SCTP_PARAM_STATE_COOKIE: 2361 asoc->peer.cookie_len = 2362 ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2363 asoc->peer.cookie = param.cookie->body; 2364 break; 2365 2366 case SCTP_PARAM_HEARTBEAT_INFO: 2367 /* Would be odd to receive, but it causes no problems. */ 2368 break; 2369 2370 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2371 /* Rejected during verify stage. */ 2372 break; 2373 2374 case SCTP_PARAM_ECN_CAPABLE: 2375 asoc->peer.ecn_capable = 1; 2376 break; 2377 2378 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2379 asoc->peer.adaptation_ind = param.aind->adaptation_ind; 2380 break; 2381 2382 case SCTP_PARAM_SUPPORTED_EXT: 2383 sctp_process_ext_param(asoc, param); 2384 break; 2385 2386 case SCTP_PARAM_FWD_TSN_SUPPORT: 2387 if (sctp_prsctp_enable) { 2388 asoc->peer.prsctp_capable = 1; 2389 break; 2390 } 2391 /* Fall Through */ 2392 goto fall_through; 2393 2394 case SCTP_PARAM_RANDOM: 2395 if (!sctp_auth_enable) 2396 goto fall_through; 2397 2398 /* Save peer's random parameter */ 2399 asoc->peer.peer_random = kmemdup(param.p, 2400 ntohs(param.p->length), gfp); 2401 if (!asoc->peer.peer_random) { 2402 retval = 0; 2403 break; 2404 } 2405 break; 2406 2407 case SCTP_PARAM_HMAC_ALGO: 2408 if (!sctp_auth_enable) 2409 goto fall_through; 2410 2411 /* Save peer's HMAC list */ 2412 asoc->peer.peer_hmacs = kmemdup(param.p, 2413 ntohs(param.p->length), gfp); 2414 if (!asoc->peer.peer_hmacs) { 2415 retval = 0; 2416 break; 2417 } 2418 2419 /* Set the default HMAC the peer requested*/ 2420 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2421 break; 2422 2423 case SCTP_PARAM_CHUNKS: 2424 if (!sctp_auth_enable) 2425 goto fall_through; 2426 2427 asoc->peer.peer_chunks = kmemdup(param.p, 2428 ntohs(param.p->length), gfp); 2429 if (!asoc->peer.peer_chunks) 2430 retval = 0; 2431 break; 2432 fall_through: 2433 default: 2434 /* Any unrecognized parameters should have been caught 2435 * and handled by sctp_verify_param() which should be 2436 * called prior to this routine. Simply log the error 2437 * here. 2438 */ 2439 SCTP_DEBUG_PRINTK("Ignoring param: %d for association %p.\n", 2440 ntohs(param.p->type), asoc); 2441 break; 2442 } 2443 2444 return retval; 2445 } 2446 2447 /* Select a new verification tag. */ 2448 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2449 { 2450 /* I believe that this random number generator complies with RFC1750. 2451 * A tag of 0 is reserved for special cases (e.g. INIT). 2452 */ 2453 __u32 x; 2454 2455 do { 2456 get_random_bytes(&x, sizeof(__u32)); 2457 } while (x == 0); 2458 2459 return x; 2460 } 2461 2462 /* Select an initial TSN to send during startup. */ 2463 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2464 { 2465 __u32 retval; 2466 2467 get_random_bytes(&retval, sizeof(__u32)); 2468 return retval; 2469 } 2470 2471 /* 2472 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2473 * 0 1 2 3 2474 * 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 2475 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2476 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2477 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2478 * | Serial Number | 2479 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2480 * | Address Parameter | 2481 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2482 * | ASCONF Parameter #1 | 2483 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2484 * \ \ 2485 * / .... / 2486 * \ \ 2487 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2488 * | ASCONF Parameter #N | 2489 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2490 * 2491 * Address Parameter and other parameter will not be wrapped in this function 2492 */ 2493 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2494 union sctp_addr *addr, 2495 int vparam_len) 2496 { 2497 sctp_addiphdr_t asconf; 2498 struct sctp_chunk *retval; 2499 int length = sizeof(asconf) + vparam_len; 2500 union sctp_addr_param addrparam; 2501 int addrlen; 2502 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2503 2504 addrlen = af->to_addr_param(addr, &addrparam); 2505 if (!addrlen) 2506 return NULL; 2507 length += addrlen; 2508 2509 /* Create the chunk. */ 2510 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF, 0, length); 2511 if (!retval) 2512 return NULL; 2513 2514 asconf.serial = htonl(asoc->addip_serial++); 2515 2516 retval->subh.addip_hdr = 2517 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2518 retval->param_hdr.v = 2519 sctp_addto_chunk(retval, addrlen, &addrparam); 2520 2521 return retval; 2522 } 2523 2524 /* ADDIP 2525 * 3.2.1 Add IP Address 2526 * 0 1 2 3 2527 * 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 2528 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2529 * | Type = 0xC001 | Length = Variable | 2530 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2531 * | ASCONF-Request Correlation ID | 2532 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2533 * | Address Parameter | 2534 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2535 * 2536 * 3.2.2 Delete IP Address 2537 * 0 1 2 3 2538 * 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 2539 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2540 * | Type = 0xC002 | Length = Variable | 2541 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2542 * | ASCONF-Request Correlation ID | 2543 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2544 * | Address Parameter | 2545 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2546 * 2547 */ 2548 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2549 union sctp_addr *laddr, 2550 struct sockaddr *addrs, 2551 int addrcnt, 2552 __be16 flags) 2553 { 2554 sctp_addip_param_t param; 2555 struct sctp_chunk *retval; 2556 union sctp_addr_param addr_param; 2557 union sctp_addr *addr; 2558 void *addr_buf; 2559 struct sctp_af *af; 2560 int paramlen = sizeof(param); 2561 int addr_param_len = 0; 2562 int totallen = 0; 2563 int i; 2564 2565 /* Get total length of all the address parameters. */ 2566 addr_buf = addrs; 2567 for (i = 0; i < addrcnt; i++) { 2568 addr = (union sctp_addr *)addr_buf; 2569 af = sctp_get_af_specific(addr->v4.sin_family); 2570 addr_param_len = af->to_addr_param(addr, &addr_param); 2571 2572 totallen += paramlen; 2573 totallen += addr_param_len; 2574 2575 addr_buf += af->sockaddr_len; 2576 } 2577 2578 /* Create an asconf chunk with the required length. */ 2579 retval = sctp_make_asconf(asoc, laddr, totallen); 2580 if (!retval) 2581 return NULL; 2582 2583 /* Add the address parameters to the asconf chunk. */ 2584 addr_buf = addrs; 2585 for (i = 0; i < addrcnt; i++) { 2586 addr = (union sctp_addr *)addr_buf; 2587 af = sctp_get_af_specific(addr->v4.sin_family); 2588 addr_param_len = af->to_addr_param(addr, &addr_param); 2589 param.param_hdr.type = flags; 2590 param.param_hdr.length = htons(paramlen + addr_param_len); 2591 param.crr_id = i; 2592 2593 sctp_addto_chunk(retval, paramlen, ¶m); 2594 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2595 2596 addr_buf += af->sockaddr_len; 2597 } 2598 return retval; 2599 } 2600 2601 /* ADDIP 2602 * 3.2.4 Set Primary IP Address 2603 * 0 1 2 3 2604 * 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 2605 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2606 * | Type =0xC004 | Length = Variable | 2607 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2608 * | ASCONF-Request Correlation ID | 2609 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2610 * | Address Parameter | 2611 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2612 * 2613 * Create an ASCONF chunk with Set Primary IP address parameter. 2614 */ 2615 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2616 union sctp_addr *addr) 2617 { 2618 sctp_addip_param_t param; 2619 struct sctp_chunk *retval; 2620 int len = sizeof(param); 2621 union sctp_addr_param addrparam; 2622 int addrlen; 2623 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2624 2625 addrlen = af->to_addr_param(addr, &addrparam); 2626 if (!addrlen) 2627 return NULL; 2628 len += addrlen; 2629 2630 /* Create the chunk and make asconf header. */ 2631 retval = sctp_make_asconf(asoc, addr, len); 2632 if (!retval) 2633 return NULL; 2634 2635 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2636 param.param_hdr.length = htons(len); 2637 param.crr_id = 0; 2638 2639 sctp_addto_chunk(retval, sizeof(param), ¶m); 2640 sctp_addto_chunk(retval, addrlen, &addrparam); 2641 2642 return retval; 2643 } 2644 2645 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2646 * 0 1 2 3 2647 * 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 2648 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2649 * | Type = 0x80 | Chunk Flags | Chunk Length | 2650 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2651 * | Serial Number | 2652 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2653 * | ASCONF Parameter Response#1 | 2654 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2655 * \ \ 2656 * / .... / 2657 * \ \ 2658 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2659 * | ASCONF Parameter Response#N | 2660 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2661 * 2662 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2663 */ 2664 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2665 __u32 serial, int vparam_len) 2666 { 2667 sctp_addiphdr_t asconf; 2668 struct sctp_chunk *retval; 2669 int length = sizeof(asconf) + vparam_len; 2670 2671 /* Create the chunk. */ 2672 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF_ACK, 0, length); 2673 if (!retval) 2674 return NULL; 2675 2676 asconf.serial = htonl(serial); 2677 2678 retval->subh.addip_hdr = 2679 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2680 2681 return retval; 2682 } 2683 2684 /* Add response parameters to an ASCONF_ACK chunk. */ 2685 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2686 __be16 err_code, sctp_addip_param_t *asconf_param) 2687 { 2688 sctp_addip_param_t ack_param; 2689 sctp_errhdr_t err_param; 2690 int asconf_param_len = 0; 2691 int err_param_len = 0; 2692 __be16 response_type; 2693 2694 if (SCTP_ERROR_NO_ERROR == err_code) { 2695 response_type = SCTP_PARAM_SUCCESS_REPORT; 2696 } else { 2697 response_type = SCTP_PARAM_ERR_CAUSE; 2698 err_param_len = sizeof(err_param); 2699 if (asconf_param) 2700 asconf_param_len = 2701 ntohs(asconf_param->param_hdr.length); 2702 } 2703 2704 /* Add Success Indication or Error Cause Indication parameter. */ 2705 ack_param.param_hdr.type = response_type; 2706 ack_param.param_hdr.length = htons(sizeof(ack_param) + 2707 err_param_len + 2708 asconf_param_len); 2709 ack_param.crr_id = crr_id; 2710 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 2711 2712 if (SCTP_ERROR_NO_ERROR == err_code) 2713 return; 2714 2715 /* Add Error Cause parameter. */ 2716 err_param.cause = err_code; 2717 err_param.length = htons(err_param_len + asconf_param_len); 2718 sctp_addto_chunk(chunk, err_param_len, &err_param); 2719 2720 /* Add the failed TLV copied from ASCONF chunk. */ 2721 if (asconf_param) 2722 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 2723 } 2724 2725 /* Process a asconf parameter. */ 2726 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 2727 struct sctp_chunk *asconf, 2728 sctp_addip_param_t *asconf_param) 2729 { 2730 struct sctp_transport *peer; 2731 struct sctp_af *af; 2732 union sctp_addr addr; 2733 struct list_head *pos; 2734 union sctp_addr_param *addr_param; 2735 2736 addr_param = (union sctp_addr_param *) 2737 ((void *)asconf_param + sizeof(sctp_addip_param_t)); 2738 2739 af = sctp_get_af_specific(param_type2af(addr_param->v4.param_hdr.type)); 2740 if (unlikely(!af)) 2741 return SCTP_ERROR_INV_PARAM; 2742 2743 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); 2744 switch (asconf_param->param_hdr.type) { 2745 case SCTP_PARAM_ADD_IP: 2746 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 2747 * request and does not have the local resources to add this 2748 * new address to the association, it MUST return an Error 2749 * Cause TLV set to the new error code 'Operation Refused 2750 * Due to Resource Shortage'. 2751 */ 2752 2753 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 2754 if (!peer) 2755 return SCTP_ERROR_RSRC_LOW; 2756 2757 /* Start the heartbeat timer. */ 2758 if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer))) 2759 sctp_transport_hold(peer); 2760 break; 2761 case SCTP_PARAM_DEL_IP: 2762 /* ADDIP 4.3 D7) If a request is received to delete the 2763 * last remaining IP address of a peer endpoint, the receiver 2764 * MUST send an Error Cause TLV with the error cause set to the 2765 * new error code 'Request to Delete Last Remaining IP Address'. 2766 */ 2767 pos = asoc->peer.transport_addr_list.next; 2768 if (pos->next == &asoc->peer.transport_addr_list) 2769 return SCTP_ERROR_DEL_LAST_IP; 2770 2771 /* ADDIP 4.3 D8) If a request is received to delete an IP 2772 * address which is also the source address of the IP packet 2773 * which contained the ASCONF chunk, the receiver MUST reject 2774 * this request. To reject the request the receiver MUST send 2775 * an Error Cause TLV set to the new error code 'Request to 2776 * Delete Source IP Address' 2777 */ 2778 if (sctp_cmp_addr_exact(sctp_source(asconf), &addr)) 2779 return SCTP_ERROR_DEL_SRC_IP; 2780 2781 sctp_assoc_del_peer(asoc, &addr); 2782 break; 2783 case SCTP_PARAM_SET_PRIMARY: 2784 peer = sctp_assoc_lookup_paddr(asoc, &addr); 2785 if (!peer) 2786 return SCTP_ERROR_INV_PARAM; 2787 2788 sctp_assoc_set_primary(asoc, peer); 2789 break; 2790 default: 2791 return SCTP_ERROR_INV_PARAM; 2792 break; 2793 } 2794 2795 return SCTP_ERROR_NO_ERROR; 2796 } 2797 2798 /* Verify the ASCONF packet before we process it. */ 2799 int sctp_verify_asconf(const struct sctp_association *asoc, 2800 struct sctp_paramhdr *param_hdr, void *chunk_end, 2801 struct sctp_paramhdr **errp) { 2802 sctp_addip_param_t *asconf_param; 2803 union sctp_params param; 2804 int length, plen; 2805 2806 param.v = (sctp_paramhdr_t *) param_hdr; 2807 while (param.v <= chunk_end - sizeof(sctp_paramhdr_t)) { 2808 length = ntohs(param.p->length); 2809 *errp = param.p; 2810 2811 if (param.v > chunk_end - length || 2812 length < sizeof(sctp_paramhdr_t)) 2813 return 0; 2814 2815 switch (param.p->type) { 2816 case SCTP_PARAM_ADD_IP: 2817 case SCTP_PARAM_DEL_IP: 2818 case SCTP_PARAM_SET_PRIMARY: 2819 asconf_param = (sctp_addip_param_t *)param.v; 2820 plen = ntohs(asconf_param->param_hdr.length); 2821 if (plen < sizeof(sctp_addip_param_t) + 2822 sizeof(sctp_paramhdr_t)) 2823 return 0; 2824 break; 2825 case SCTP_PARAM_SUCCESS_REPORT: 2826 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2827 if (length != sizeof(sctp_addip_param_t)) 2828 return 0; 2829 2830 break; 2831 default: 2832 break; 2833 } 2834 2835 param.v += WORD_ROUND(length); 2836 } 2837 2838 if (param.v != chunk_end) 2839 return 0; 2840 2841 return 1; 2842 } 2843 2844 /* Process an incoming ASCONF chunk with the next expected serial no. and 2845 * return an ASCONF_ACK chunk to be sent in response. 2846 */ 2847 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 2848 struct sctp_chunk *asconf) 2849 { 2850 sctp_addiphdr_t *hdr; 2851 union sctp_addr_param *addr_param; 2852 sctp_addip_param_t *asconf_param; 2853 struct sctp_chunk *asconf_ack; 2854 2855 __be16 err_code; 2856 int length = 0; 2857 int chunk_len = asconf->skb->len; 2858 __u32 serial; 2859 int all_param_pass = 1; 2860 2861 hdr = (sctp_addiphdr_t *)asconf->skb->data; 2862 serial = ntohl(hdr->serial); 2863 2864 /* Skip the addiphdr and store a pointer to address parameter. */ 2865 length = sizeof(sctp_addiphdr_t); 2866 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 2867 chunk_len -= length; 2868 2869 /* Skip the address parameter and store a pointer to the first 2870 * asconf paramter. 2871 */ 2872 length = ntohs(addr_param->v4.param_hdr.length); 2873 asconf_param = (sctp_addip_param_t *)((void *)addr_param + length); 2874 chunk_len -= length; 2875 2876 /* create an ASCONF_ACK chunk. 2877 * Based on the definitions of parameters, we know that the size of 2878 * ASCONF_ACK parameters are less than or equal to the twice of ASCONF 2879 * paramters. 2880 */ 2881 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 2); 2882 if (!asconf_ack) 2883 goto done; 2884 2885 /* Process the TLVs contained within the ASCONF chunk. */ 2886 while (chunk_len > 0) { 2887 err_code = sctp_process_asconf_param(asoc, asconf, 2888 asconf_param); 2889 /* ADDIP 4.1 A7) 2890 * If an error response is received for a TLV parameter, 2891 * all TLVs with no response before the failed TLV are 2892 * considered successful if not reported. All TLVs after 2893 * the failed response are considered unsuccessful unless 2894 * a specific success indication is present for the parameter. 2895 */ 2896 if (SCTP_ERROR_NO_ERROR != err_code) 2897 all_param_pass = 0; 2898 2899 if (!all_param_pass) 2900 sctp_add_asconf_response(asconf_ack, 2901 asconf_param->crr_id, err_code, 2902 asconf_param); 2903 2904 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 2905 * an IP address sends an 'Out of Resource' in its response, it 2906 * MUST also fail any subsequent add or delete requests bundled 2907 * in the ASCONF. 2908 */ 2909 if (SCTP_ERROR_RSRC_LOW == err_code) 2910 goto done; 2911 2912 /* Move to the next ASCONF param. */ 2913 length = ntohs(asconf_param->param_hdr.length); 2914 asconf_param = (sctp_addip_param_t *)((void *)asconf_param + 2915 length); 2916 chunk_len -= length; 2917 } 2918 2919 done: 2920 asoc->peer.addip_serial++; 2921 2922 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 2923 * after freeing the reference to old asconf ack if any. 2924 */ 2925 if (asconf_ack) { 2926 if (asoc->addip_last_asconf_ack) 2927 sctp_chunk_free(asoc->addip_last_asconf_ack); 2928 2929 sctp_chunk_hold(asconf_ack); 2930 asoc->addip_last_asconf_ack = asconf_ack; 2931 } 2932 2933 return asconf_ack; 2934 } 2935 2936 /* Process a asconf parameter that is successfully acked. */ 2937 static int sctp_asconf_param_success(struct sctp_association *asoc, 2938 sctp_addip_param_t *asconf_param) 2939 { 2940 struct sctp_af *af; 2941 union sctp_addr addr; 2942 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 2943 union sctp_addr_param *addr_param; 2944 struct list_head *pos; 2945 struct sctp_transport *transport; 2946 struct sctp_sockaddr_entry *saddr; 2947 int retval = 0; 2948 2949 addr_param = (union sctp_addr_param *) 2950 ((void *)asconf_param + sizeof(sctp_addip_param_t)); 2951 2952 /* We have checked the packet before, so we do not check again. */ 2953 af = sctp_get_af_specific(param_type2af(addr_param->v4.param_hdr.type)); 2954 af->from_addr_param(&addr, addr_param, htons(bp->port), 0); 2955 2956 switch (asconf_param->param_hdr.type) { 2957 case SCTP_PARAM_ADD_IP: 2958 /* This is always done in BH context with a socket lock 2959 * held, so the list can not change. 2960 */ 2961 list_for_each_entry(saddr, &bp->address_list, list) { 2962 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 2963 saddr->use_as_src = 1; 2964 } 2965 break; 2966 case SCTP_PARAM_DEL_IP: 2967 retval = sctp_del_bind_addr(bp, &addr, call_rcu_bh); 2968 list_for_each(pos, &asoc->peer.transport_addr_list) { 2969 transport = list_entry(pos, struct sctp_transport, 2970 transports); 2971 dst_release(transport->dst); 2972 sctp_transport_route(transport, NULL, 2973 sctp_sk(asoc->base.sk)); 2974 } 2975 break; 2976 default: 2977 break; 2978 } 2979 2980 return retval; 2981 } 2982 2983 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 2984 * for the given asconf parameter. If there is no response for this parameter, 2985 * return the error code based on the third argument 'no_err'. 2986 * ADDIP 4.1 2987 * A7) If an error response is received for a TLV parameter, all TLVs with no 2988 * response before the failed TLV are considered successful if not reported. 2989 * All TLVs after the failed response are considered unsuccessful unless a 2990 * specific success indication is present for the parameter. 2991 */ 2992 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 2993 sctp_addip_param_t *asconf_param, 2994 int no_err) 2995 { 2996 sctp_addip_param_t *asconf_ack_param; 2997 sctp_errhdr_t *err_param; 2998 int length; 2999 int asconf_ack_len = asconf_ack->skb->len; 3000 __be16 err_code; 3001 3002 if (no_err) 3003 err_code = SCTP_ERROR_NO_ERROR; 3004 else 3005 err_code = SCTP_ERROR_REQ_REFUSED; 3006 3007 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3008 * the first asconf_ack parameter. 3009 */ 3010 length = sizeof(sctp_addiphdr_t); 3011 asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data + 3012 length); 3013 asconf_ack_len -= length; 3014 3015 while (asconf_ack_len > 0) { 3016 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3017 switch(asconf_ack_param->param_hdr.type) { 3018 case SCTP_PARAM_SUCCESS_REPORT: 3019 return SCTP_ERROR_NO_ERROR; 3020 case SCTP_PARAM_ERR_CAUSE: 3021 length = sizeof(sctp_addip_param_t); 3022 err_param = (sctp_errhdr_t *) 3023 ((void *)asconf_ack_param + length); 3024 asconf_ack_len -= length; 3025 if (asconf_ack_len > 0) 3026 return err_param->cause; 3027 else 3028 return SCTP_ERROR_INV_PARAM; 3029 break; 3030 default: 3031 return SCTP_ERROR_INV_PARAM; 3032 } 3033 } 3034 3035 length = ntohs(asconf_ack_param->param_hdr.length); 3036 asconf_ack_param = (sctp_addip_param_t *) 3037 ((void *)asconf_ack_param + length); 3038 asconf_ack_len -= length; 3039 } 3040 3041 return err_code; 3042 } 3043 3044 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3045 int sctp_process_asconf_ack(struct sctp_association *asoc, 3046 struct sctp_chunk *asconf_ack) 3047 { 3048 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3049 union sctp_addr_param *addr_param; 3050 sctp_addip_param_t *asconf_param; 3051 int length = 0; 3052 int asconf_len = asconf->skb->len; 3053 int all_param_pass = 0; 3054 int no_err = 1; 3055 int retval = 0; 3056 __be16 err_code = SCTP_ERROR_NO_ERROR; 3057 3058 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3059 * a pointer to address parameter. 3060 */ 3061 length = sizeof(sctp_addip_chunk_t); 3062 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3063 asconf_len -= length; 3064 3065 /* Skip the address parameter in the last asconf sent and store a 3066 * pointer to the first asconf paramter. 3067 */ 3068 length = ntohs(addr_param->v4.param_hdr.length); 3069 asconf_param = (sctp_addip_param_t *)((void *)addr_param + length); 3070 asconf_len -= length; 3071 3072 /* ADDIP 4.1 3073 * A8) If there is no response(s) to specific TLV parameter(s), and no 3074 * failures are indicated, then all request(s) are considered 3075 * successful. 3076 */ 3077 if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t)) 3078 all_param_pass = 1; 3079 3080 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3081 while (asconf_len > 0) { 3082 if (all_param_pass) 3083 err_code = SCTP_ERROR_NO_ERROR; 3084 else { 3085 err_code = sctp_get_asconf_response(asconf_ack, 3086 asconf_param, 3087 no_err); 3088 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3089 no_err = 0; 3090 } 3091 3092 switch (err_code) { 3093 case SCTP_ERROR_NO_ERROR: 3094 retval = sctp_asconf_param_success(asoc, asconf_param); 3095 break; 3096 3097 case SCTP_ERROR_RSRC_LOW: 3098 retval = 1; 3099 break; 3100 3101 case SCTP_ERROR_INV_PARAM: 3102 /* Disable sending this type of asconf parameter in 3103 * future. 3104 */ 3105 asoc->peer.addip_disabled_mask |= 3106 asconf_param->param_hdr.type; 3107 break; 3108 3109 case SCTP_ERROR_REQ_REFUSED: 3110 case SCTP_ERROR_DEL_LAST_IP: 3111 case SCTP_ERROR_DEL_SRC_IP: 3112 default: 3113 break; 3114 } 3115 3116 /* Skip the processed asconf parameter and move to the next 3117 * one. 3118 */ 3119 length = ntohs(asconf_param->param_hdr.length); 3120 asconf_param = (sctp_addip_param_t *)((void *)asconf_param + 3121 length); 3122 asconf_len -= length; 3123 } 3124 3125 /* Free the cached last sent asconf chunk. */ 3126 sctp_chunk_free(asconf); 3127 asoc->addip_last_asconf = NULL; 3128 3129 /* Send the next asconf chunk from the addip chunk queue. */ 3130 if (!list_empty(&asoc->addip_chunk_list)) { 3131 struct list_head *entry = asoc->addip_chunk_list.next; 3132 asconf = list_entry(entry, struct sctp_chunk, list); 3133 3134 list_del_init(entry); 3135 3136 /* Hold the chunk until an ASCONF_ACK is received. */ 3137 sctp_chunk_hold(asconf); 3138 if (sctp_primitive_ASCONF(asoc, asconf)) 3139 sctp_chunk_free(asconf); 3140 else 3141 asoc->addip_last_asconf = asconf; 3142 } 3143 3144 return retval; 3145 } 3146 3147 /* Make a FWD TSN chunk. */ 3148 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3149 __u32 new_cum_tsn, size_t nstreams, 3150 struct sctp_fwdtsn_skip *skiplist) 3151 { 3152 struct sctp_chunk *retval = NULL; 3153 struct sctp_fwdtsn_chunk *ftsn_chunk; 3154 struct sctp_fwdtsn_hdr ftsn_hdr; 3155 struct sctp_fwdtsn_skip skip; 3156 size_t hint; 3157 int i; 3158 3159 hint = (nstreams + 1) * sizeof(__u32); 3160 3161 retval = sctp_make_chunk(asoc, SCTP_CID_FWD_TSN, 0, hint); 3162 3163 if (!retval) 3164 return NULL; 3165 3166 ftsn_chunk = (struct sctp_fwdtsn_chunk *)retval->subh.fwdtsn_hdr; 3167 3168 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3169 retval->subh.fwdtsn_hdr = 3170 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3171 3172 for (i = 0; i < nstreams; i++) { 3173 skip.stream = skiplist[i].stream; 3174 skip.ssn = skiplist[i].ssn; 3175 sctp_addto_chunk(retval, sizeof(skip), &skip); 3176 } 3177 3178 return retval; 3179 } 3180