1 /* SCTP kernel implementation 2 * (C) Copyright IBM Corp. 2001, 2004 3 * Copyright (c) 1999-2000 Cisco, Inc. 4 * Copyright (c) 1999-2001 Motorola, Inc. 5 * Copyright (c) 2001-2002 Intel Corp. 6 * 7 * This file is part of the SCTP kernel implementation 8 * 9 * These functions work with the state functions in sctp_sm_statefuns.c 10 * to implement the state operations. These functions implement the 11 * steps which require modifying existing data structures. 12 * 13 * This SCTP implementation is free software; 14 * you can redistribute it and/or modify it under the terms of 15 * the GNU General Public License as published by 16 * the Free Software Foundation; either version 2, or (at your option) 17 * any later version. 18 * 19 * This SCTP implementation is distributed in the hope that it 20 * will be useful, but WITHOUT ANY WARRANTY; without even the implied 21 * ************************ 22 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 23 * See the GNU General Public License for more details. 24 * 25 * You should have received a copy of the GNU General Public License 26 * along with GNU CC; see the file COPYING. If not, write to 27 * the Free Software Foundation, 59 Temple Place - Suite 330, 28 * Boston, MA 02111-1307, USA. 29 * 30 * Please send any bug reports or fixes you make to the 31 * email address(es): 32 * lksctp developers <lksctp-developers@lists.sourceforge.net> 33 * 34 * Or submit a bug report through the following website: 35 * http://www.sf.net/projects/lksctp 36 * 37 * Written or modified by: 38 * La Monte H.P. Yarroll <piggy@acm.org> 39 * Karl Knutson <karl@athena.chicago.il.us> 40 * C. Robin <chris@hundredacre.ac.uk> 41 * Jon Grimm <jgrimm@us.ibm.com> 42 * Xingang Guo <xingang.guo@intel.com> 43 * Dajiang Zhang <dajiang.zhang@nokia.com> 44 * Sridhar Samudrala <sri@us.ibm.com> 45 * Daisy Chang <daisyc@us.ibm.com> 46 * Ardelle Fan <ardelle.fan@intel.com> 47 * Kevin Gao <kevin.gao@intel.com> 48 * 49 * Any bugs reported given to us we will try to fix... any fixes shared will 50 * be incorporated into the next SCTP release. 51 */ 52 53 #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 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 81 const void *data); 82 83 /* What was the inbound interface for this chunk? */ 84 int sctp_chunk_iif(const struct sctp_chunk *chunk) 85 { 86 struct sctp_af *af; 87 int iif = 0; 88 89 af = sctp_get_af_specific(ipver2af(ip_hdr(chunk->skb)->version)); 90 if (af) 91 iif = af->skb_iif(chunk->skb); 92 93 return iif; 94 } 95 96 /* RFC 2960 3.3.2 Initiation (INIT) (1) 97 * 98 * Note 2: The ECN capable field is reserved for future use of 99 * Explicit Congestion Notification. 100 */ 101 static const struct sctp_paramhdr ecap_param = { 102 SCTP_PARAM_ECN_CAPABLE, 103 __constant_htons(sizeof(struct sctp_paramhdr)), 104 }; 105 static const struct sctp_paramhdr prsctp_param = { 106 SCTP_PARAM_FWD_TSN_SUPPORT, 107 __constant_htons(sizeof(struct sctp_paramhdr)), 108 }; 109 110 /* A helper to initialize to initialize an op error inside a 111 * provided chunk, as most cause codes will be embedded inside an 112 * abort chunk. 113 */ 114 void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, 115 size_t paylen) 116 { 117 sctp_errhdr_t err; 118 __u16 len; 119 120 /* Cause code constants are now defined in network order. */ 121 err.cause = cause_code; 122 len = sizeof(sctp_errhdr_t) + paylen; 123 err.length = htons(len); 124 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err); 125 } 126 127 /* 3.3.2 Initiation (INIT) (1) 128 * 129 * This chunk is used to initiate a SCTP association between two 130 * endpoints. The format of the INIT chunk is shown below: 131 * 132 * 0 1 2 3 133 * 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 1 134 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 135 * | Type = 1 | Chunk Flags | Chunk Length | 136 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 137 * | Initiate Tag | 138 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 139 * | Advertised Receiver Window Credit (a_rwnd) | 140 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 141 * | Number of Outbound Streams | Number of Inbound Streams | 142 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 143 * | Initial TSN | 144 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 145 * \ \ 146 * / Optional/Variable-Length Parameters / 147 * \ \ 148 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 149 * 150 * 151 * The INIT chunk contains the following parameters. Unless otherwise 152 * noted, each parameter MUST only be included once in the INIT chunk. 153 * 154 * Fixed Parameters Status 155 * ---------------------------------------------- 156 * Initiate Tag Mandatory 157 * Advertised Receiver Window Credit Mandatory 158 * Number of Outbound Streams Mandatory 159 * Number of Inbound Streams Mandatory 160 * Initial TSN Mandatory 161 * 162 * Variable Parameters Status Type Value 163 * ------------------------------------------------------------- 164 * IPv4 Address (Note 1) Optional 5 165 * IPv6 Address (Note 1) Optional 6 166 * Cookie Preservative Optional 9 167 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000) 168 * Host Name Address (Note 3) Optional 11 169 * Supported Address Types (Note 4) Optional 12 170 */ 171 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc, 172 const struct sctp_bind_addr *bp, 173 gfp_t gfp, int vparam_len) 174 { 175 sctp_inithdr_t init; 176 union sctp_params addrs; 177 size_t chunksize; 178 struct sctp_chunk *retval = NULL; 179 int num_types, addrs_len = 0; 180 struct sctp_sock *sp; 181 sctp_supported_addrs_param_t sat; 182 __be16 types[2]; 183 sctp_adaptation_ind_param_t aiparam; 184 sctp_supported_ext_param_t ext_param; 185 int num_ext = 0; 186 __u8 extensions[3]; 187 sctp_paramhdr_t *auth_chunks = NULL, 188 *auth_hmacs = NULL; 189 190 /* RFC 2960 3.3.2 Initiation (INIT) (1) 191 * 192 * Note 1: The INIT chunks can contain multiple addresses that 193 * can be IPv4 and/or IPv6 in any combination. 194 */ 195 retval = NULL; 196 197 /* Convert the provided bind address list to raw format. */ 198 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp); 199 200 init.init_tag = htonl(asoc->c.my_vtag); 201 init.a_rwnd = htonl(asoc->rwnd); 202 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 203 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 204 init.initial_tsn = htonl(asoc->c.initial_tsn); 205 206 /* How many address types are needed? */ 207 sp = sctp_sk(asoc->base.sk); 208 num_types = sp->pf->supported_addrs(sp, types); 209 210 chunksize = sizeof(init) + addrs_len + SCTP_SAT_LEN(num_types); 211 chunksize += sizeof(ecap_param); 212 213 if (sctp_prsctp_enable) 214 chunksize += sizeof(prsctp_param); 215 216 /* ADDIP: Section 4.2.7: 217 * An implementation supporting this extension [ADDIP] MUST list 218 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and 219 * INIT-ACK parameters. 220 */ 221 if (sctp_addip_enable) { 222 extensions[num_ext] = SCTP_CID_ASCONF; 223 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 224 num_ext += 2; 225 } 226 227 chunksize += sizeof(aiparam); 228 chunksize += vparam_len; 229 230 /* Account for AUTH related parameters */ 231 if (sctp_auth_enable) { 232 /* Add random parameter length*/ 233 chunksize += sizeof(asoc->c.auth_random); 234 235 /* Add HMACS parameter length if any were defined */ 236 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs; 237 if (auth_hmacs->length) 238 chunksize += ntohs(auth_hmacs->length); 239 else 240 auth_hmacs = NULL; 241 242 /* Add CHUNKS parameter length */ 243 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks; 244 if (auth_chunks->length) 245 chunksize += ntohs(auth_chunks->length); 246 else 247 auth_chunks = NULL; 248 249 extensions[num_ext] = SCTP_CID_AUTH; 250 num_ext += 1; 251 } 252 253 /* If we have any extensions to report, account for that */ 254 if (num_ext) 255 chunksize += sizeof(sctp_supported_ext_param_t) + num_ext; 256 257 /* RFC 2960 3.3.2 Initiation (INIT) (1) 258 * 259 * Note 3: An INIT chunk MUST NOT contain more than one Host 260 * Name address parameter. Moreover, the sender of the INIT 261 * MUST NOT combine any other address types with the Host Name 262 * address in the INIT. The receiver of INIT MUST ignore any 263 * other address types if the Host Name address parameter is 264 * present in the received INIT chunk. 265 * 266 * PLEASE DO NOT FIXME [This version does not support Host Name.] 267 */ 268 269 retval = sctp_make_chunk(asoc, SCTP_CID_INIT, 0, chunksize); 270 if (!retval) 271 goto nodata; 272 273 retval->subh.init_hdr = 274 sctp_addto_chunk(retval, sizeof(init), &init); 275 retval->param_hdr.v = 276 sctp_addto_chunk(retval, addrs_len, addrs.v); 277 278 /* RFC 2960 3.3.2 Initiation (INIT) (1) 279 * 280 * Note 4: This parameter, when present, specifies all the 281 * address types the sending endpoint can support. The absence 282 * of this parameter indicates that the sending endpoint can 283 * support any address type. 284 */ 285 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES; 286 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types)); 287 sctp_addto_chunk(retval, sizeof(sat), &sat); 288 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types); 289 290 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 291 292 /* Add the supported extensions parameter. Be nice and add this 293 * fist before addiding the parameters for the extensions themselves 294 */ 295 if (num_ext) { 296 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 297 ext_param.param_hdr.length = 298 htons(sizeof(sctp_supported_ext_param_t) + num_ext); 299 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t), 300 &ext_param); 301 sctp_addto_param(retval, num_ext, extensions); 302 } 303 304 if (sctp_prsctp_enable) 305 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 306 307 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 308 aiparam.param_hdr.length = htons(sizeof(aiparam)); 309 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 310 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 311 312 /* Add SCTP-AUTH chunks to the parameter list */ 313 if (sctp_auth_enable) { 314 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random), 315 asoc->c.auth_random); 316 if (auth_hmacs) 317 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 318 auth_hmacs); 319 if (auth_chunks) 320 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 321 auth_chunks); 322 } 323 nodata: 324 kfree(addrs.v); 325 return retval; 326 } 327 328 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, 329 const struct sctp_chunk *chunk, 330 gfp_t gfp, int unkparam_len) 331 { 332 sctp_inithdr_t initack; 333 struct sctp_chunk *retval; 334 union sctp_params addrs; 335 int addrs_len; 336 sctp_cookie_param_t *cookie; 337 int cookie_len; 338 size_t chunksize; 339 sctp_adaptation_ind_param_t aiparam; 340 sctp_supported_ext_param_t ext_param; 341 int num_ext = 0; 342 __u8 extensions[3]; 343 sctp_paramhdr_t *auth_chunks = NULL, 344 *auth_hmacs = NULL, 345 *auth_random = NULL; 346 347 retval = NULL; 348 349 /* Note: there may be no addresses to embed. */ 350 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp); 351 352 initack.init_tag = htonl(asoc->c.my_vtag); 353 initack.a_rwnd = htonl(asoc->rwnd); 354 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 355 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 356 initack.initial_tsn = htonl(asoc->c.initial_tsn); 357 358 /* FIXME: We really ought to build the cookie right 359 * into the packet instead of allocating more fresh memory. 360 */ 361 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len, 362 addrs.v, addrs_len); 363 if (!cookie) 364 goto nomem_cookie; 365 366 /* Calculate the total size of allocation, include the reserved 367 * space for reporting unknown parameters if it is specified. 368 */ 369 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len; 370 371 /* Tell peer that we'll do ECN only if peer advertised such cap. */ 372 if (asoc->peer.ecn_capable) 373 chunksize += sizeof(ecap_param); 374 375 if (sctp_prsctp_enable) 376 chunksize += sizeof(prsctp_param); 377 378 if (sctp_addip_enable) { 379 extensions[num_ext] = SCTP_CID_ASCONF; 380 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 381 num_ext += 2; 382 } 383 384 chunksize += sizeof(aiparam); 385 386 if (asoc->peer.auth_capable) { 387 auth_random = (sctp_paramhdr_t *)asoc->c.auth_random; 388 chunksize += ntohs(auth_random->length); 389 390 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs; 391 if (auth_hmacs->length) 392 chunksize += ntohs(auth_hmacs->length); 393 else 394 auth_hmacs = NULL; 395 396 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks; 397 if (auth_chunks->length) 398 chunksize += ntohs(auth_chunks->length); 399 else 400 auth_chunks = NULL; 401 402 extensions[num_ext] = SCTP_CID_AUTH; 403 num_ext += 1; 404 } 405 406 if (num_ext) 407 chunksize += sizeof(sctp_supported_ext_param_t) + num_ext; 408 409 /* Now allocate and fill out the chunk. */ 410 retval = sctp_make_chunk(asoc, SCTP_CID_INIT_ACK, 0, chunksize); 411 if (!retval) 412 goto nomem_chunk; 413 414 /* Per the advice in RFC 2960 6.4, send this reply to 415 * the source of the INIT packet. 416 */ 417 retval->transport = chunk->transport; 418 retval->subh.init_hdr = 419 sctp_addto_chunk(retval, sizeof(initack), &initack); 420 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); 421 sctp_addto_chunk(retval, cookie_len, cookie); 422 if (asoc->peer.ecn_capable) 423 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 424 if (num_ext) { 425 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 426 ext_param.param_hdr.length = 427 htons(sizeof(sctp_supported_ext_param_t) + num_ext); 428 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t), 429 &ext_param); 430 sctp_addto_param(retval, num_ext, extensions); 431 } 432 if (asoc->peer.prsctp_capable) 433 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 434 435 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 436 aiparam.param_hdr.length = htons(sizeof(aiparam)); 437 aiparam.adaptation_ind = htonl(sctp_sk(asoc->base.sk)->adaptation_ind); 438 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 439 440 if (asoc->peer.auth_capable) { 441 sctp_addto_chunk(retval, ntohs(auth_random->length), 442 auth_random); 443 if (auth_hmacs) 444 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 445 auth_hmacs); 446 if (auth_chunks) 447 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 448 auth_chunks); 449 } 450 451 /* We need to remove the const qualifier at this point. */ 452 retval->asoc = (struct sctp_association *) asoc; 453 454 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 455 * 456 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 457 * HEARTBEAT ACK, * etc.) to the same destination transport 458 * address from which it received the DATA or control chunk 459 * to which it is replying. 460 * 461 * [INIT ACK back to where the INIT came from.] 462 */ 463 if (chunk) 464 retval->transport = chunk->transport; 465 466 nomem_chunk: 467 kfree(cookie); 468 nomem_cookie: 469 kfree(addrs.v); 470 return retval; 471 } 472 473 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10): 474 * 475 * This chunk is used only during the initialization of an association. 476 * It is sent by the initiator of an association to its peer to complete 477 * the initialization process. This chunk MUST precede any DATA chunk 478 * sent within the association, but MAY be bundled with one or more DATA 479 * chunks in the same packet. 480 * 481 * 0 1 2 3 482 * 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 1 483 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 484 * | Type = 10 |Chunk Flags | Length | 485 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 486 * / Cookie / 487 * \ \ 488 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 489 * 490 * Chunk Flags: 8 bit 491 * 492 * Set to zero on transmit and ignored on receipt. 493 * 494 * Length: 16 bits (unsigned integer) 495 * 496 * Set to the size of the chunk in bytes, including the 4 bytes of 497 * the chunk header and the size of the Cookie. 498 * 499 * Cookie: variable size 500 * 501 * This field must contain the exact cookie received in the 502 * State Cookie parameter from the previous INIT ACK. 503 * 504 * An implementation SHOULD make the cookie as small as possible 505 * to insure interoperability. 506 */ 507 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, 508 const struct sctp_chunk *chunk) 509 { 510 struct sctp_chunk *retval; 511 void *cookie; 512 int cookie_len; 513 514 cookie = asoc->peer.cookie; 515 cookie_len = asoc->peer.cookie_len; 516 517 /* Build a cookie echo chunk. */ 518 retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ECHO, 0, cookie_len); 519 if (!retval) 520 goto nodata; 521 retval->subh.cookie_hdr = 522 sctp_addto_chunk(retval, cookie_len, cookie); 523 524 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 525 * 526 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 527 * HEARTBEAT ACK, * etc.) to the same destination transport 528 * address from which it * received the DATA or control chunk 529 * to which it is replying. 530 * 531 * [COOKIE ECHO back to where the INIT ACK came from.] 532 */ 533 if (chunk) 534 retval->transport = chunk->transport; 535 536 nodata: 537 return retval; 538 } 539 540 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11): 541 * 542 * This chunk is used only during the initialization of an 543 * association. It is used to acknowledge the receipt of a COOKIE 544 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent 545 * within the association, but MAY be bundled with one or more DATA 546 * chunks or SACK chunk in the same SCTP packet. 547 * 548 * 0 1 2 3 549 * 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 1 550 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 551 * | Type = 11 |Chunk Flags | Length = 4 | 552 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 553 * 554 * Chunk Flags: 8 bits 555 * 556 * Set to zero on transmit and ignored on receipt. 557 */ 558 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, 559 const struct sctp_chunk *chunk) 560 { 561 struct sctp_chunk *retval; 562 563 retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ACK, 0, 0); 564 565 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 566 * 567 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 568 * HEARTBEAT ACK, * etc.) to the same destination transport 569 * address from which it * received the DATA or control chunk 570 * to which it is replying. 571 * 572 * [COOKIE ACK back to where the COOKIE ECHO came from.] 573 */ 574 if (retval && chunk) 575 retval->transport = chunk->transport; 576 577 return retval; 578 } 579 580 /* 581 * Appendix A: Explicit Congestion Notification: 582 * CWR: 583 * 584 * RFC 2481 details a specific bit for a sender to send in the header of 585 * its next outbound TCP segment to indicate to its peer that it has 586 * reduced its congestion window. This is termed the CWR bit. For 587 * SCTP the same indication is made by including the CWR chunk. 588 * This chunk contains one data element, i.e. the TSN number that 589 * was sent in the ECNE chunk. This element represents the lowest 590 * TSN number in the datagram that was originally marked with the 591 * CE bit. 592 * 593 * 0 1 2 3 594 * 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 1 595 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 596 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 | 597 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 598 * | Lowest TSN Number | 599 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 600 * 601 * Note: The CWR is considered a Control chunk. 602 */ 603 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, 604 const __u32 lowest_tsn, 605 const struct sctp_chunk *chunk) 606 { 607 struct sctp_chunk *retval; 608 sctp_cwrhdr_t cwr; 609 610 cwr.lowest_tsn = htonl(lowest_tsn); 611 retval = sctp_make_chunk(asoc, SCTP_CID_ECN_CWR, 0, 612 sizeof(sctp_cwrhdr_t)); 613 614 if (!retval) 615 goto nodata; 616 617 retval->subh.ecn_cwr_hdr = 618 sctp_addto_chunk(retval, sizeof(cwr), &cwr); 619 620 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 621 * 622 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 623 * HEARTBEAT ACK, * etc.) to the same destination transport 624 * address from which it * received the DATA or control chunk 625 * to which it is replying. 626 * 627 * [Report a reduced congestion window back to where the ECNE 628 * came from.] 629 */ 630 if (chunk) 631 retval->transport = chunk->transport; 632 633 nodata: 634 return retval; 635 } 636 637 /* Make an ECNE chunk. This is a congestion experienced report. */ 638 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, 639 const __u32 lowest_tsn) 640 { 641 struct sctp_chunk *retval; 642 sctp_ecnehdr_t ecne; 643 644 ecne.lowest_tsn = htonl(lowest_tsn); 645 retval = sctp_make_chunk(asoc, SCTP_CID_ECN_ECNE, 0, 646 sizeof(sctp_ecnehdr_t)); 647 if (!retval) 648 goto nodata; 649 retval->subh.ecne_hdr = 650 sctp_addto_chunk(retval, sizeof(ecne), &ecne); 651 652 nodata: 653 return retval; 654 } 655 656 /* Make a DATA chunk for the given association from the provided 657 * parameters. However, do not populate the data payload. 658 */ 659 struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc, 660 const struct sctp_sndrcvinfo *sinfo, 661 int data_len, __u8 flags, __u16 ssn) 662 { 663 struct sctp_chunk *retval; 664 struct sctp_datahdr dp; 665 int chunk_len; 666 667 /* We assign the TSN as LATE as possible, not here when 668 * creating the chunk. 669 */ 670 dp.tsn = 0; 671 dp.stream = htons(sinfo->sinfo_stream); 672 dp.ppid = sinfo->sinfo_ppid; 673 674 /* Set the flags for an unordered send. */ 675 if (sinfo->sinfo_flags & SCTP_UNORDERED) { 676 flags |= SCTP_DATA_UNORDERED; 677 dp.ssn = 0; 678 } else 679 dp.ssn = htons(ssn); 680 681 chunk_len = sizeof(dp) + data_len; 682 retval = sctp_make_chunk(asoc, SCTP_CID_DATA, flags, chunk_len); 683 if (!retval) 684 goto nodata; 685 686 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp); 687 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo)); 688 689 nodata: 690 return retval; 691 } 692 693 /* Create a selective ackowledgement (SACK) for the given 694 * association. This reports on which TSN's we've seen to date, 695 * including duplicates and gaps. 696 */ 697 struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc) 698 { 699 struct sctp_chunk *retval; 700 struct sctp_sackhdr sack; 701 int len; 702 __u32 ctsn; 703 __u16 num_gabs, num_dup_tsns; 704 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; 705 706 ctsn = sctp_tsnmap_get_ctsn(map); 707 SCTP_DEBUG_PRINTK("sackCTSNAck sent: 0x%x.\n", ctsn); 708 709 /* How much room is needed in the chunk? */ 710 num_gabs = sctp_tsnmap_num_gabs(map); 711 num_dup_tsns = sctp_tsnmap_num_dups(map); 712 713 /* Initialize the SACK header. */ 714 sack.cum_tsn_ack = htonl(ctsn); 715 sack.a_rwnd = htonl(asoc->a_rwnd); 716 sack.num_gap_ack_blocks = htons(num_gabs); 717 sack.num_dup_tsns = htons(num_dup_tsns); 718 719 len = sizeof(sack) 720 + sizeof(struct sctp_gap_ack_block) * num_gabs 721 + sizeof(__u32) * num_dup_tsns; 722 723 /* Create the chunk. */ 724 retval = sctp_make_chunk(asoc, SCTP_CID_SACK, 0, len); 725 if (!retval) 726 goto nodata; 727 728 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 729 * 730 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 731 * HEARTBEAT ACK, etc.) to the same destination transport 732 * address from which it received the DATA or control chunk to 733 * which it is replying. This rule should also be followed if 734 * the endpoint is bundling DATA chunks together with the 735 * reply chunk. 736 * 737 * However, when acknowledging multiple DATA chunks received 738 * in packets from different source addresses in a single 739 * SACK, the SACK chunk may be transmitted to one of the 740 * destination transport addresses from which the DATA or 741 * control chunks being acknowledged were received. 742 * 743 * [BUG: We do not implement the following paragraph. 744 * Perhaps we should remember the last transport we used for a 745 * SACK and avoid that (if possible) if we have seen any 746 * duplicates. --piggy] 747 * 748 * When a receiver of a duplicate DATA chunk sends a SACK to a 749 * multi- homed endpoint it MAY be beneficial to vary the 750 * destination address and not use the source address of the 751 * DATA chunk. The reason being that receiving a duplicate 752 * from a multi-homed endpoint might indicate that the return 753 * path (as specified in the source address of the DATA chunk) 754 * for the SACK is broken. 755 * 756 * [Send to the address from which we last received a DATA chunk.] 757 */ 758 retval->transport = asoc->peer.last_data_from; 759 760 retval->subh.sack_hdr = 761 sctp_addto_chunk(retval, sizeof(sack), &sack); 762 763 /* Add the gap ack block information. */ 764 if (num_gabs) 765 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, 766 sctp_tsnmap_get_gabs(map)); 767 768 /* Add the duplicate TSN information. */ 769 if (num_dup_tsns) 770 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, 771 sctp_tsnmap_get_dups(map)); 772 773 nodata: 774 return retval; 775 } 776 777 /* Make a SHUTDOWN chunk. */ 778 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 779 const struct sctp_chunk *chunk) 780 { 781 struct sctp_chunk *retval; 782 sctp_shutdownhdr_t shut; 783 __u32 ctsn; 784 785 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 786 shut.cum_tsn_ack = htonl(ctsn); 787 788 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN, 0, 789 sizeof(sctp_shutdownhdr_t)); 790 if (!retval) 791 goto nodata; 792 793 retval->subh.shutdown_hdr = 794 sctp_addto_chunk(retval, sizeof(shut), &shut); 795 796 if (chunk) 797 retval->transport = chunk->transport; 798 nodata: 799 return retval; 800 } 801 802 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 803 const struct sctp_chunk *chunk) 804 { 805 struct sctp_chunk *retval; 806 807 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0); 808 809 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 810 * 811 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 812 * HEARTBEAT ACK, * etc.) to the same destination transport 813 * address from which it * received the DATA or control chunk 814 * to which it is replying. 815 * 816 * [ACK back to where the SHUTDOWN came from.] 817 */ 818 if (retval && chunk) 819 retval->transport = chunk->transport; 820 821 return retval; 822 } 823 824 struct sctp_chunk *sctp_make_shutdown_complete( 825 const struct sctp_association *asoc, 826 const struct sctp_chunk *chunk) 827 { 828 struct sctp_chunk *retval; 829 __u8 flags = 0; 830 831 /* Set the T-bit if we have no association (vtag will be 832 * reflected) 833 */ 834 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; 835 836 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0); 837 838 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 839 * 840 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 841 * HEARTBEAT ACK, * etc.) to the same destination transport 842 * address from which it * received the DATA or control chunk 843 * to which it is replying. 844 * 845 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK 846 * came from.] 847 */ 848 if (retval && chunk) 849 retval->transport = chunk->transport; 850 851 return retval; 852 } 853 854 /* Create an ABORT. Note that we set the T bit if we have no 855 * association, except when responding to an INIT (sctpimpguide 2.41). 856 */ 857 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 858 const struct sctp_chunk *chunk, 859 const size_t hint) 860 { 861 struct sctp_chunk *retval; 862 __u8 flags = 0; 863 864 /* Set the T-bit if we have no association and 'chunk' is not 865 * an INIT (vtag will be reflected). 866 */ 867 if (!asoc) { 868 if (chunk && chunk->chunk_hdr && 869 chunk->chunk_hdr->type == SCTP_CID_INIT) 870 flags = 0; 871 else 872 flags = SCTP_CHUNK_FLAG_T; 873 } 874 875 retval = sctp_make_chunk(asoc, SCTP_CID_ABORT, flags, hint); 876 877 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 878 * 879 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 880 * HEARTBEAT ACK, * etc.) to the same destination transport 881 * address from which it * received the DATA or control chunk 882 * to which it is replying. 883 * 884 * [ABORT back to where the offender came from.] 885 */ 886 if (retval && chunk) 887 retval->transport = chunk->transport; 888 889 return retval; 890 } 891 892 /* Helper to create ABORT with a NO_USER_DATA error. */ 893 struct sctp_chunk *sctp_make_abort_no_data( 894 const struct sctp_association *asoc, 895 const struct sctp_chunk *chunk, __u32 tsn) 896 { 897 struct sctp_chunk *retval; 898 __be32 payload; 899 900 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) 901 + sizeof(tsn)); 902 903 if (!retval) 904 goto no_mem; 905 906 /* Put the tsn back into network byte order. */ 907 payload = htonl(tsn); 908 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload)); 909 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload); 910 911 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 912 * 913 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 914 * HEARTBEAT ACK, * etc.) to the same destination transport 915 * address from which it * received the DATA or control chunk 916 * to which it is replying. 917 * 918 * [ABORT back to where the offender came from.] 919 */ 920 if (chunk) 921 retval->transport = chunk->transport; 922 923 no_mem: 924 return retval; 925 } 926 927 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ 928 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 929 const struct msghdr *msg, 930 size_t paylen) 931 { 932 struct sctp_chunk *retval; 933 void *payload = NULL; 934 int err; 935 936 retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen); 937 if (!retval) 938 goto err_chunk; 939 940 if (paylen) { 941 /* Put the msg_iov together into payload. */ 942 payload = kmalloc(paylen, GFP_KERNEL); 943 if (!payload) 944 goto err_payload; 945 946 err = memcpy_fromiovec(payload, msg->msg_iov, paylen); 947 if (err < 0) 948 goto err_copy; 949 } 950 951 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); 952 sctp_addto_chunk(retval, paylen, payload); 953 954 if (paylen) 955 kfree(payload); 956 957 return retval; 958 959 err_copy: 960 kfree(payload); 961 err_payload: 962 sctp_chunk_free(retval); 963 retval = NULL; 964 err_chunk: 965 return retval; 966 } 967 968 /* Append bytes to the end of a parameter. Will panic if chunk is not big 969 * enough. 970 */ 971 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 972 const void *data) 973 { 974 void *target; 975 int chunklen = ntohs(chunk->chunk_hdr->length); 976 977 target = skb_put(chunk->skb, len); 978 979 memcpy(target, data, len); 980 981 /* Adjust the chunk length field. */ 982 chunk->chunk_hdr->length = htons(chunklen + len); 983 chunk->chunk_end = skb_tail_pointer(chunk->skb); 984 985 return target; 986 } 987 988 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ 989 struct sctp_chunk *sctp_make_abort_violation( 990 const struct sctp_association *asoc, 991 const struct sctp_chunk *chunk, 992 const __u8 *payload, 993 const size_t paylen) 994 { 995 struct sctp_chunk *retval; 996 struct sctp_paramhdr phdr; 997 998 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen 999 + sizeof(sctp_paramhdr_t)); 1000 if (!retval) 1001 goto end; 1002 1003 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen 1004 + sizeof(sctp_paramhdr_t)); 1005 1006 phdr.type = htons(chunk->chunk_hdr->type); 1007 phdr.length = chunk->chunk_hdr->length; 1008 sctp_addto_chunk(retval, paylen, payload); 1009 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr); 1010 1011 end: 1012 return retval; 1013 } 1014 1015 /* Make a HEARTBEAT chunk. */ 1016 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1017 const struct sctp_transport *transport, 1018 const void *payload, const size_t paylen) 1019 { 1020 struct sctp_chunk *retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT, 1021 0, paylen); 1022 1023 if (!retval) 1024 goto nodata; 1025 1026 /* Cast away the 'const', as this is just telling the chunk 1027 * what transport it belongs to. 1028 */ 1029 retval->transport = (struct sctp_transport *) transport; 1030 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1031 1032 nodata: 1033 return retval; 1034 } 1035 1036 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1037 const struct sctp_chunk *chunk, 1038 const void *payload, const size_t paylen) 1039 { 1040 struct sctp_chunk *retval; 1041 1042 retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen); 1043 if (!retval) 1044 goto nodata; 1045 1046 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1047 1048 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1049 * 1050 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1051 * HEARTBEAT ACK, * etc.) to the same destination transport 1052 * address from which it * received the DATA or control chunk 1053 * to which it is replying. 1054 * 1055 * [HBACK back to where the HEARTBEAT came from.] 1056 */ 1057 if (chunk) 1058 retval->transport = chunk->transport; 1059 1060 nodata: 1061 return retval; 1062 } 1063 1064 /* Create an Operation Error chunk with the specified space reserved. 1065 * This routine can be used for containing multiple causes in the chunk. 1066 */ 1067 static struct sctp_chunk *sctp_make_op_error_space( 1068 const struct sctp_association *asoc, 1069 const struct sctp_chunk *chunk, 1070 size_t size) 1071 { 1072 struct sctp_chunk *retval; 1073 1074 retval = sctp_make_chunk(asoc, SCTP_CID_ERROR, 0, 1075 sizeof(sctp_errhdr_t) + size); 1076 if (!retval) 1077 goto nodata; 1078 1079 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1080 * 1081 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1082 * HEARTBEAT ACK, etc.) to the same destination transport 1083 * address from which it received the DATA or control chunk 1084 * to which it is replying. 1085 * 1086 */ 1087 if (chunk) 1088 retval->transport = chunk->transport; 1089 1090 nodata: 1091 return retval; 1092 } 1093 1094 /* Create an Operation Error chunk. */ 1095 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1096 const struct sctp_chunk *chunk, 1097 __be16 cause_code, const void *payload, 1098 size_t paylen) 1099 { 1100 struct sctp_chunk *retval; 1101 1102 retval = sctp_make_op_error_space(asoc, chunk, paylen); 1103 if (!retval) 1104 goto nodata; 1105 1106 sctp_init_cause(retval, cause_code, paylen); 1107 sctp_addto_chunk(retval, paylen, payload); 1108 1109 nodata: 1110 return retval; 1111 } 1112 1113 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc) 1114 { 1115 struct sctp_chunk *retval; 1116 struct sctp_hmac *hmac_desc; 1117 struct sctp_authhdr auth_hdr; 1118 __u8 *hmac; 1119 1120 /* Get the first hmac that the peer told us to use */ 1121 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1122 if (unlikely(!hmac_desc)) 1123 return NULL; 1124 1125 retval = sctp_make_chunk(asoc, SCTP_CID_AUTH, 0, 1126 hmac_desc->hmac_len + sizeof(sctp_authhdr_t)); 1127 if (!retval) 1128 return NULL; 1129 1130 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1131 auth_hdr.shkey_id = htons(asoc->active_key_id); 1132 1133 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t), 1134 &auth_hdr); 1135 1136 hmac = skb_put(retval->skb, hmac_desc->hmac_len); 1137 memset(hmac, 0, hmac_desc->hmac_len); 1138 1139 /* Adjust the chunk header to include the empty MAC */ 1140 retval->chunk_hdr->length = 1141 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1142 retval->chunk_end = skb_tail_pointer(retval->skb); 1143 1144 return retval; 1145 } 1146 1147 1148 /******************************************************************** 1149 * 2nd Level Abstractions 1150 ********************************************************************/ 1151 1152 /* Turn an skb into a chunk. 1153 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1154 */ 1155 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1156 const struct sctp_association *asoc, 1157 struct sock *sk) 1158 { 1159 struct sctp_chunk *retval; 1160 1161 retval = kmem_cache_zalloc(sctp_chunk_cachep, GFP_ATOMIC); 1162 1163 if (!retval) 1164 goto nodata; 1165 1166 if (!sk) { 1167 SCTP_DEBUG_PRINTK("chunkifying skb %p w/o an sk\n", skb); 1168 } 1169 1170 INIT_LIST_HEAD(&retval->list); 1171 retval->skb = skb; 1172 retval->asoc = (struct sctp_association *)asoc; 1173 retval->resent = 0; 1174 retval->has_tsn = 0; 1175 retval->has_ssn = 0; 1176 retval->rtt_in_progress = 0; 1177 retval->sent_at = 0; 1178 retval->singleton = 1; 1179 retval->end_of_packet = 0; 1180 retval->ecn_ce_done = 0; 1181 retval->pdiscard = 0; 1182 1183 /* sctpimpguide-05.txt Section 2.8.2 1184 * M1) Each time a new DATA chunk is transmitted 1185 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1186 * 'TSN.Missing.Report' count will be used to determine missing chunks 1187 * and when to fast retransmit. 1188 */ 1189 retval->tsn_missing_report = 0; 1190 retval->tsn_gap_acked = 0; 1191 retval->fast_retransmit = 0; 1192 1193 /* If this is a fragmented message, track all fragments 1194 * of the message (for SEND_FAILED). 1195 */ 1196 retval->msg = NULL; 1197 1198 /* Polish the bead hole. */ 1199 INIT_LIST_HEAD(&retval->transmitted_list); 1200 INIT_LIST_HEAD(&retval->frag_list); 1201 SCTP_DBG_OBJCNT_INC(chunk); 1202 atomic_set(&retval->refcnt, 1); 1203 1204 nodata: 1205 return retval; 1206 } 1207 1208 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1209 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1210 union sctp_addr *dest) 1211 { 1212 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1213 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1214 } 1215 1216 /* Extract the source address from a chunk. */ 1217 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1218 { 1219 /* If we have a known transport, use that. */ 1220 if (chunk->transport) { 1221 return &chunk->transport->ipaddr; 1222 } else { 1223 /* Otherwise, extract it from the IP header. */ 1224 return &chunk->source; 1225 } 1226 } 1227 1228 /* Create a new chunk, setting the type and flags headers from the 1229 * arguments, reserving enough space for a 'paylen' byte payload. 1230 */ 1231 SCTP_STATIC 1232 struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc, 1233 __u8 type, __u8 flags, int paylen) 1234 { 1235 struct sctp_chunk *retval; 1236 sctp_chunkhdr_t *chunk_hdr; 1237 struct sk_buff *skb; 1238 struct sock *sk; 1239 1240 /* No need to allocate LL here, as this is only a chunk. */ 1241 skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen), 1242 GFP_ATOMIC); 1243 if (!skb) 1244 goto nodata; 1245 1246 /* Make room for the chunk header. */ 1247 chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t)); 1248 chunk_hdr->type = type; 1249 chunk_hdr->flags = flags; 1250 chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t)); 1251 1252 sk = asoc ? asoc->base.sk : NULL; 1253 retval = sctp_chunkify(skb, asoc, sk); 1254 if (!retval) { 1255 kfree_skb(skb); 1256 goto nodata; 1257 } 1258 1259 retval->chunk_hdr = chunk_hdr; 1260 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr); 1261 1262 /* Determine if the chunk needs to be authenticated */ 1263 if (sctp_auth_send_cid(type, asoc)) 1264 retval->auth = 1; 1265 1266 /* Set the skb to the belonging sock for accounting. */ 1267 skb->sk = sk; 1268 1269 return retval; 1270 nodata: 1271 return NULL; 1272 } 1273 1274 1275 /* Release the memory occupied by a chunk. */ 1276 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1277 { 1278 BUG_ON(!list_empty(&chunk->list)); 1279 list_del_init(&chunk->transmitted_list); 1280 1281 /* Free the chunk skb data and the SCTP_chunk stub itself. */ 1282 dev_kfree_skb(chunk->skb); 1283 1284 SCTP_DBG_OBJCNT_DEC(chunk); 1285 kmem_cache_free(sctp_chunk_cachep, chunk); 1286 } 1287 1288 /* Possibly, free the chunk. */ 1289 void sctp_chunk_free(struct sctp_chunk *chunk) 1290 { 1291 /* Release our reference on the message tracker. */ 1292 if (chunk->msg) 1293 sctp_datamsg_put(chunk->msg); 1294 1295 sctp_chunk_put(chunk); 1296 } 1297 1298 /* Grab a reference to the chunk. */ 1299 void sctp_chunk_hold(struct sctp_chunk *ch) 1300 { 1301 atomic_inc(&ch->refcnt); 1302 } 1303 1304 /* Release a reference to the chunk. */ 1305 void sctp_chunk_put(struct sctp_chunk *ch) 1306 { 1307 if (atomic_dec_and_test(&ch->refcnt)) 1308 sctp_chunk_destroy(ch); 1309 } 1310 1311 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1312 * enough. 1313 */ 1314 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1315 { 1316 void *target; 1317 void *padding; 1318 int chunklen = ntohs(chunk->chunk_hdr->length); 1319 int padlen = WORD_ROUND(chunklen) - chunklen; 1320 1321 padding = skb_put(chunk->skb, padlen); 1322 target = skb_put(chunk->skb, len); 1323 1324 memset(padding, 0, padlen); 1325 memcpy(target, data, len); 1326 1327 /* Adjust the chunk length field. */ 1328 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1329 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1330 1331 return target; 1332 } 1333 1334 /* Append bytes from user space to the end of a chunk. Will panic if 1335 * chunk is not big enough. 1336 * Returns a kernel err value. 1337 */ 1338 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len, 1339 struct iovec *data) 1340 { 1341 __u8 *target; 1342 int err = 0; 1343 1344 /* Make room in chunk for data. */ 1345 target = skb_put(chunk->skb, len); 1346 1347 /* Copy data (whole iovec) into chunk */ 1348 if ((err = memcpy_fromiovecend(target, data, off, len))) 1349 goto out; 1350 1351 /* Adjust the chunk length field. */ 1352 chunk->chunk_hdr->length = 1353 htons(ntohs(chunk->chunk_hdr->length) + len); 1354 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1355 1356 out: 1357 return err; 1358 } 1359 1360 /* Helper function to assign a TSN if needed. This assumes that both 1361 * the data_hdr and association have already been assigned. 1362 */ 1363 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1364 { 1365 struct sctp_datamsg *msg; 1366 struct sctp_chunk *lchunk; 1367 struct sctp_stream *stream; 1368 __u16 ssn; 1369 __u16 sid; 1370 1371 if (chunk->has_ssn) 1372 return; 1373 1374 /* All fragments will be on the same stream */ 1375 sid = ntohs(chunk->subh.data_hdr->stream); 1376 stream = &chunk->asoc->ssnmap->out; 1377 1378 /* Now assign the sequence number to the entire message. 1379 * All fragments must have the same stream sequence number. 1380 */ 1381 msg = chunk->msg; 1382 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1383 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1384 ssn = 0; 1385 } else { 1386 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1387 ssn = sctp_ssn_next(stream, sid); 1388 else 1389 ssn = sctp_ssn_peek(stream, sid); 1390 } 1391 1392 lchunk->subh.data_hdr->ssn = htons(ssn); 1393 lchunk->has_ssn = 1; 1394 } 1395 } 1396 1397 /* Helper function to assign a TSN if needed. This assumes that both 1398 * the data_hdr and association have already been assigned. 1399 */ 1400 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1401 { 1402 if (!chunk->has_tsn) { 1403 /* This is the last possible instant to 1404 * assign a TSN. 1405 */ 1406 chunk->subh.data_hdr->tsn = 1407 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1408 chunk->has_tsn = 1; 1409 } 1410 } 1411 1412 /* Create a CLOSED association to use with an incoming packet. */ 1413 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1414 struct sctp_chunk *chunk, 1415 gfp_t gfp) 1416 { 1417 struct sctp_association *asoc; 1418 struct sk_buff *skb; 1419 sctp_scope_t scope; 1420 struct sctp_af *af; 1421 1422 /* Create the bare association. */ 1423 scope = sctp_scope(sctp_source(chunk)); 1424 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1425 if (!asoc) 1426 goto nodata; 1427 asoc->temp = 1; 1428 skb = chunk->skb; 1429 /* Create an entry for the source address of the packet. */ 1430 af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version)); 1431 if (unlikely(!af)) 1432 goto fail; 1433 af->from_skb(&asoc->c.peer_addr, skb, 1); 1434 nodata: 1435 return asoc; 1436 1437 fail: 1438 sctp_association_free(asoc); 1439 return NULL; 1440 } 1441 1442 /* Build a cookie representing asoc. 1443 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1444 */ 1445 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, 1446 const struct sctp_association *asoc, 1447 const struct sctp_chunk *init_chunk, 1448 int *cookie_len, 1449 const __u8 *raw_addrs, int addrs_len) 1450 { 1451 sctp_cookie_param_t *retval; 1452 struct sctp_signed_cookie *cookie; 1453 struct scatterlist sg; 1454 int headersize, bodysize; 1455 unsigned int keylen; 1456 char *key; 1457 1458 /* Header size is static data prior to the actual cookie, including 1459 * any padding. 1460 */ 1461 headersize = sizeof(sctp_paramhdr_t) + 1462 (sizeof(struct sctp_signed_cookie) - 1463 sizeof(struct sctp_cookie)); 1464 bodysize = sizeof(struct sctp_cookie) 1465 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1466 1467 /* Pad out the cookie to a multiple to make the signature 1468 * functions simpler to write. 1469 */ 1470 if (bodysize % SCTP_COOKIE_MULTIPLE) 1471 bodysize += SCTP_COOKIE_MULTIPLE 1472 - (bodysize % SCTP_COOKIE_MULTIPLE); 1473 *cookie_len = headersize + bodysize; 1474 1475 /* Clear this memory since we are sending this data structure 1476 * out on the network. 1477 */ 1478 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1479 if (!retval) 1480 goto nodata; 1481 1482 cookie = (struct sctp_signed_cookie *) retval->body; 1483 1484 /* Set up the parameter header. */ 1485 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1486 retval->p.length = htons(*cookie_len); 1487 1488 /* Copy the cookie part of the association itself. */ 1489 cookie->c = asoc->c; 1490 /* Save the raw address list length in the cookie. */ 1491 cookie->c.raw_addr_list_len = addrs_len; 1492 1493 /* Remember PR-SCTP capability. */ 1494 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1495 1496 /* Save adaptation indication in the cookie. */ 1497 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1498 1499 /* Set an expiration time for the cookie. */ 1500 do_gettimeofday(&cookie->c.expiration); 1501 TIMEVAL_ADD(asoc->cookie_life, cookie->c.expiration); 1502 1503 /* Copy the peer's init packet. */ 1504 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr, 1505 ntohs(init_chunk->chunk_hdr->length)); 1506 1507 /* Copy the raw local address list of the association. */ 1508 memcpy((__u8 *)&cookie->c.peer_init[0] + 1509 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1510 1511 if (sctp_sk(ep->base.sk)->hmac) { 1512 struct hash_desc desc; 1513 1514 /* Sign the message. */ 1515 sg_init_one(&sg, &cookie->c, bodysize); 1516 keylen = SCTP_SECRET_SIZE; 1517 key = (char *)ep->secret_key[ep->current_key]; 1518 desc.tfm = sctp_sk(ep->base.sk)->hmac; 1519 desc.flags = 0; 1520 1521 if (crypto_hash_setkey(desc.tfm, key, keylen) || 1522 crypto_hash_digest(&desc, &sg, bodysize, cookie->signature)) 1523 goto free_cookie; 1524 } 1525 1526 return retval; 1527 1528 free_cookie: 1529 kfree(retval); 1530 nodata: 1531 *cookie_len = 0; 1532 return NULL; 1533 } 1534 1535 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1536 struct sctp_association *sctp_unpack_cookie( 1537 const struct sctp_endpoint *ep, 1538 const struct sctp_association *asoc, 1539 struct sctp_chunk *chunk, gfp_t gfp, 1540 int *error, struct sctp_chunk **errp) 1541 { 1542 struct sctp_association *retval = NULL; 1543 struct sctp_signed_cookie *cookie; 1544 struct sctp_cookie *bear_cookie; 1545 int headersize, bodysize, fixed_size; 1546 __u8 *digest = ep->digest; 1547 struct scatterlist sg; 1548 unsigned int keylen, len; 1549 char *key; 1550 sctp_scope_t scope; 1551 struct sk_buff *skb = chunk->skb; 1552 struct timeval tv; 1553 struct hash_desc desc; 1554 1555 /* Header size is static data prior to the actual cookie, including 1556 * any padding. 1557 */ 1558 headersize = sizeof(sctp_chunkhdr_t) + 1559 (sizeof(struct sctp_signed_cookie) - 1560 sizeof(struct sctp_cookie)); 1561 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1562 fixed_size = headersize + sizeof(struct sctp_cookie); 1563 1564 /* Verify that the chunk looks like it even has a cookie. 1565 * There must be enough room for our cookie and our peer's 1566 * INIT chunk. 1567 */ 1568 len = ntohs(chunk->chunk_hdr->length); 1569 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1570 goto malformed; 1571 1572 /* Verify that the cookie has been padded out. */ 1573 if (bodysize % SCTP_COOKIE_MULTIPLE) 1574 goto malformed; 1575 1576 /* Process the cookie. */ 1577 cookie = chunk->subh.cookie_hdr; 1578 bear_cookie = &cookie->c; 1579 1580 if (!sctp_sk(ep->base.sk)->hmac) 1581 goto no_hmac; 1582 1583 /* Check the signature. */ 1584 keylen = SCTP_SECRET_SIZE; 1585 sg_init_one(&sg, bear_cookie, bodysize); 1586 key = (char *)ep->secret_key[ep->current_key]; 1587 desc.tfm = sctp_sk(ep->base.sk)->hmac; 1588 desc.flags = 0; 1589 1590 memset(digest, 0x00, SCTP_SIGNATURE_SIZE); 1591 if (crypto_hash_setkey(desc.tfm, key, keylen) || 1592 crypto_hash_digest(&desc, &sg, bodysize, digest)) { 1593 *error = -SCTP_IERROR_NOMEM; 1594 goto fail; 1595 } 1596 1597 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1598 /* Try the previous key. */ 1599 key = (char *)ep->secret_key[ep->last_key]; 1600 memset(digest, 0x00, SCTP_SIGNATURE_SIZE); 1601 if (crypto_hash_setkey(desc.tfm, key, keylen) || 1602 crypto_hash_digest(&desc, &sg, bodysize, digest)) { 1603 *error = -SCTP_IERROR_NOMEM; 1604 goto fail; 1605 } 1606 1607 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1608 /* Yikes! Still bad signature! */ 1609 *error = -SCTP_IERROR_BAD_SIG; 1610 goto fail; 1611 } 1612 } 1613 1614 no_hmac: 1615 /* IG Section 2.35.2: 1616 * 3) Compare the port numbers and the verification tag contained 1617 * within the COOKIE ECHO chunk to the actual port numbers and the 1618 * verification tag within the SCTP common header of the received 1619 * packet. If these values do not match the packet MUST be silently 1620 * discarded, 1621 */ 1622 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1623 *error = -SCTP_IERROR_BAD_TAG; 1624 goto fail; 1625 } 1626 1627 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1628 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1629 *error = -SCTP_IERROR_BAD_PORTS; 1630 goto fail; 1631 } 1632 1633 /* Check to see if the cookie is stale. If there is already 1634 * an association, there is no need to check cookie's expiration 1635 * for init collision case of lost COOKIE ACK. 1636 * If skb has been timestamped, then use the stamp, otherwise 1637 * use current time. This introduces a small possibility that 1638 * that a cookie may be considered expired, but his would only slow 1639 * down the new association establishment instead of every packet. 1640 */ 1641 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1642 skb_get_timestamp(skb, &tv); 1643 else 1644 do_gettimeofday(&tv); 1645 1646 if (!asoc && tv_lt(bear_cookie->expiration, tv)) { 1647 /* 1648 * Section 3.3.10.3 Stale Cookie Error (3) 1649 * 1650 * Cause of error 1651 * --------------- 1652 * Stale Cookie Error: Indicates the receipt of a valid State 1653 * Cookie that has expired. 1654 */ 1655 len = ntohs(chunk->chunk_hdr->length); 1656 *errp = sctp_make_op_error_space(asoc, chunk, len); 1657 if (*errp) { 1658 suseconds_t usecs = (tv.tv_sec - 1659 bear_cookie->expiration.tv_sec) * 1000000L + 1660 tv.tv_usec - bear_cookie->expiration.tv_usec; 1661 __be32 n = htonl(usecs); 1662 1663 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE, 1664 sizeof(n)); 1665 sctp_addto_chunk(*errp, sizeof(n), &n); 1666 *error = -SCTP_IERROR_STALE_COOKIE; 1667 } else 1668 *error = -SCTP_IERROR_NOMEM; 1669 1670 goto fail; 1671 } 1672 1673 /* Make a new base association. */ 1674 scope = sctp_scope(sctp_source(chunk)); 1675 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1676 if (!retval) { 1677 *error = -SCTP_IERROR_NOMEM; 1678 goto fail; 1679 } 1680 1681 /* Set up our peer's port number. */ 1682 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1683 1684 /* Populate the association from the cookie. */ 1685 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1686 1687 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1688 GFP_ATOMIC) < 0) { 1689 *error = -SCTP_IERROR_NOMEM; 1690 goto fail; 1691 } 1692 1693 /* Also, add the destination address. */ 1694 if (list_empty(&retval->base.bind_addr.address_list)) { 1695 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1696 SCTP_ADDR_SRC, GFP_ATOMIC); 1697 } 1698 1699 retval->next_tsn = retval->c.initial_tsn; 1700 retval->ctsn_ack_point = retval->next_tsn - 1; 1701 retval->addip_serial = retval->c.initial_tsn; 1702 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1703 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1704 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1705 1706 /* The INIT stuff will be done by the side effects. */ 1707 return retval; 1708 1709 fail: 1710 if (retval) 1711 sctp_association_free(retval); 1712 1713 return NULL; 1714 1715 malformed: 1716 /* Yikes! The packet is either corrupt or deliberately 1717 * malformed. 1718 */ 1719 *error = -SCTP_IERROR_MALFORMED; 1720 goto fail; 1721 } 1722 1723 /******************************************************************** 1724 * 3rd Level Abstractions 1725 ********************************************************************/ 1726 1727 struct __sctp_missing { 1728 __be32 num_missing; 1729 __be16 type; 1730 } __attribute__((packed)); 1731 1732 /* 1733 * Report a missing mandatory parameter. 1734 */ 1735 static int sctp_process_missing_param(const struct sctp_association *asoc, 1736 sctp_param_t paramtype, 1737 struct sctp_chunk *chunk, 1738 struct sctp_chunk **errp) 1739 { 1740 struct __sctp_missing report; 1741 __u16 len; 1742 1743 len = WORD_ROUND(sizeof(report)); 1744 1745 /* Make an ERROR chunk, preparing enough room for 1746 * returning multiple unknown parameters. 1747 */ 1748 if (!*errp) 1749 *errp = sctp_make_op_error_space(asoc, chunk, len); 1750 1751 if (*errp) { 1752 report.num_missing = htonl(1); 1753 report.type = paramtype; 1754 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1755 sizeof(report)); 1756 sctp_addto_chunk(*errp, sizeof(report), &report); 1757 } 1758 1759 /* Stop processing this chunk. */ 1760 return 0; 1761 } 1762 1763 /* Report an Invalid Mandatory Parameter. */ 1764 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1765 struct sctp_chunk *chunk, 1766 struct sctp_chunk **errp) 1767 { 1768 /* Invalid Mandatory Parameter Error has no payload. */ 1769 1770 if (!*errp) 1771 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1772 1773 if (*errp) 1774 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1775 1776 /* Stop processing this chunk. */ 1777 return 0; 1778 } 1779 1780 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1781 struct sctp_paramhdr *param, 1782 const struct sctp_chunk *chunk, 1783 struct sctp_chunk **errp) 1784 { 1785 char error[] = "The following parameter had invalid length:"; 1786 size_t payload_len = WORD_ROUND(sizeof(error)) + 1787 sizeof(sctp_paramhdr_t); 1788 1789 1790 /* This is a fatal error. Any accumulated non-fatal errors are 1791 * not reported. 1792 */ 1793 if (*errp) 1794 sctp_chunk_free(*errp); 1795 1796 /* Create an error chunk and fill it in with our payload. */ 1797 *errp = sctp_make_op_error_space(asoc, chunk, payload_len); 1798 1799 if (*errp) { 1800 sctp_init_cause(*errp, SCTP_ERROR_PROTO_VIOLATION, 1801 sizeof(error) + sizeof(sctp_paramhdr_t)); 1802 sctp_addto_chunk(*errp, sizeof(error), error); 1803 sctp_addto_param(*errp, sizeof(sctp_paramhdr_t), param); 1804 } 1805 1806 return 0; 1807 } 1808 1809 1810 /* Do not attempt to handle the HOST_NAME parm. However, do 1811 * send back an indicator to the peer. 1812 */ 1813 static int sctp_process_hn_param(const struct sctp_association *asoc, 1814 union sctp_params param, 1815 struct sctp_chunk *chunk, 1816 struct sctp_chunk **errp) 1817 { 1818 __u16 len = ntohs(param.p->length); 1819 1820 /* Processing of the HOST_NAME parameter will generate an 1821 * ABORT. If we've accumulated any non-fatal errors, they 1822 * would be unrecognized parameters and we should not include 1823 * them in the ABORT. 1824 */ 1825 if (*errp) 1826 sctp_chunk_free(*errp); 1827 1828 *errp = sctp_make_op_error_space(asoc, chunk, len); 1829 1830 if (*errp) { 1831 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len); 1832 sctp_addto_chunk(*errp, len, param.v); 1833 } 1834 1835 /* Stop processing this chunk. */ 1836 return 0; 1837 } 1838 1839 static int sctp_verify_ext_param(union sctp_params param) 1840 { 1841 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 1842 int have_auth = 0; 1843 int have_asconf = 0; 1844 int i; 1845 1846 for (i = 0; i < num_ext; i++) { 1847 switch (param.ext->chunks[i]) { 1848 case SCTP_CID_AUTH: 1849 have_auth = 1; 1850 break; 1851 case SCTP_CID_ASCONF: 1852 case SCTP_CID_ASCONF_ACK: 1853 have_asconf = 1; 1854 break; 1855 } 1856 } 1857 1858 /* ADD-IP Security: The draft requires us to ABORT or ignore the 1859 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 1860 * only if ADD-IP is turned on and we are not backward-compatible 1861 * mode. 1862 */ 1863 if (sctp_addip_noauth) 1864 return 1; 1865 1866 if (sctp_addip_enable && !have_auth && have_asconf) 1867 return 0; 1868 1869 return 1; 1870 } 1871 1872 static void sctp_process_ext_param(struct sctp_association *asoc, 1873 union sctp_params param) 1874 { 1875 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 1876 int i; 1877 1878 for (i = 0; i < num_ext; i++) { 1879 switch (param.ext->chunks[i]) { 1880 case SCTP_CID_FWD_TSN: 1881 if (sctp_prsctp_enable && 1882 !asoc->peer.prsctp_capable) 1883 asoc->peer.prsctp_capable = 1; 1884 break; 1885 case SCTP_CID_AUTH: 1886 /* if the peer reports AUTH, assume that he 1887 * supports AUTH. 1888 */ 1889 asoc->peer.auth_capable = 1; 1890 break; 1891 case SCTP_CID_ASCONF: 1892 case SCTP_CID_ASCONF_ACK: 1893 asoc->peer.asconf_capable = 1; 1894 break; 1895 default: 1896 break; 1897 } 1898 } 1899 } 1900 1901 /* RFC 3.2.1 & the Implementers Guide 2.2. 1902 * 1903 * The Parameter Types are encoded such that the 1904 * highest-order two bits specify the action that must be 1905 * taken if the processing endpoint does not recognize the 1906 * Parameter Type. 1907 * 1908 * 00 - Stop processing this parameter; do not process any further 1909 * parameters within this chunk 1910 * 1911 * 01 - Stop processing this parameter, do not process any further 1912 * parameters within this chunk, and report the unrecognized 1913 * parameter in an 'Unrecognized Parameter' ERROR chunk. 1914 * 1915 * 10 - Skip this parameter and continue processing. 1916 * 1917 * 11 - Skip this parameter and continue processing but 1918 * report the unrecognized parameter in an 1919 * 'Unrecognized Parameter' ERROR chunk. 1920 * 1921 * Return value: 1922 * SCTP_IERROR_NO_ERROR - continue with the chunk 1923 * SCTP_IERROR_ERROR - stop and report an error. 1924 * SCTP_IERROR_NOMEME - out of memory. 1925 */ 1926 static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc, 1927 union sctp_params param, 1928 struct sctp_chunk *chunk, 1929 struct sctp_chunk **errp) 1930 { 1931 int retval = SCTP_IERROR_NO_ERROR; 1932 1933 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 1934 case SCTP_PARAM_ACTION_DISCARD: 1935 retval = SCTP_IERROR_ERROR; 1936 break; 1937 case SCTP_PARAM_ACTION_SKIP: 1938 break; 1939 case SCTP_PARAM_ACTION_DISCARD_ERR: 1940 retval = SCTP_IERROR_ERROR; 1941 /* Fall through */ 1942 case SCTP_PARAM_ACTION_SKIP_ERR: 1943 /* Make an ERROR chunk, preparing enough room for 1944 * returning multiple unknown parameters. 1945 */ 1946 if (NULL == *errp) 1947 *errp = sctp_make_op_error_space(asoc, chunk, 1948 ntohs(chunk->chunk_hdr->length)); 1949 1950 if (*errp) { 1951 sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, 1952 WORD_ROUND(ntohs(param.p->length))); 1953 sctp_addto_chunk(*errp, 1954 WORD_ROUND(ntohs(param.p->length)), 1955 param.v); 1956 } else { 1957 /* If there is no memory for generating the ERROR 1958 * report as specified, an ABORT will be triggered 1959 * to the peer and the association won't be 1960 * established. 1961 */ 1962 retval = SCTP_IERROR_NOMEM; 1963 } 1964 break; 1965 default: 1966 break; 1967 } 1968 1969 return retval; 1970 } 1971 1972 /* Verify variable length parameters 1973 * Return values: 1974 * SCTP_IERROR_ABORT - trigger an ABORT 1975 * SCTP_IERROR_NOMEM - out of memory (abort) 1976 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 1977 * SCTP_IERROR_NO_ERROR - continue with the chunk 1978 */ 1979 static sctp_ierror_t sctp_verify_param(const struct sctp_association *asoc, 1980 union sctp_params param, 1981 sctp_cid_t cid, 1982 struct sctp_chunk *chunk, 1983 struct sctp_chunk **err_chunk) 1984 { 1985 int retval = SCTP_IERROR_NO_ERROR; 1986 1987 /* FIXME - This routine is not looking at each parameter per the 1988 * chunk type, i.e., unrecognized parameters should be further 1989 * identified based on the chunk id. 1990 */ 1991 1992 switch (param.p->type) { 1993 case SCTP_PARAM_IPV4_ADDRESS: 1994 case SCTP_PARAM_IPV6_ADDRESS: 1995 case SCTP_PARAM_COOKIE_PRESERVATIVE: 1996 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 1997 case SCTP_PARAM_STATE_COOKIE: 1998 case SCTP_PARAM_HEARTBEAT_INFO: 1999 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2000 case SCTP_PARAM_ECN_CAPABLE: 2001 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2002 break; 2003 2004 case SCTP_PARAM_SUPPORTED_EXT: 2005 if (!sctp_verify_ext_param(param)) 2006 return SCTP_IERROR_ABORT; 2007 break; 2008 2009 case SCTP_PARAM_SET_PRIMARY: 2010 if (sctp_addip_enable) 2011 break; 2012 goto fallthrough; 2013 2014 case SCTP_PARAM_HOST_NAME_ADDRESS: 2015 /* Tell the peer, we won't support this param. */ 2016 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2017 retval = SCTP_IERROR_ABORT; 2018 break; 2019 2020 case SCTP_PARAM_FWD_TSN_SUPPORT: 2021 if (sctp_prsctp_enable) 2022 break; 2023 goto fallthrough; 2024 2025 case SCTP_PARAM_RANDOM: 2026 if (!sctp_auth_enable) 2027 goto fallthrough; 2028 2029 /* SCTP-AUTH: Secion 6.1 2030 * If the random number is not 32 byte long the association 2031 * MUST be aborted. The ABORT chunk SHOULD contain the error 2032 * cause 'Protocol Violation'. 2033 */ 2034 if (SCTP_AUTH_RANDOM_LENGTH != 2035 ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) { 2036 sctp_process_inv_paramlength(asoc, param.p, 2037 chunk, err_chunk); 2038 retval = SCTP_IERROR_ABORT; 2039 } 2040 break; 2041 2042 case SCTP_PARAM_CHUNKS: 2043 if (!sctp_auth_enable) 2044 goto fallthrough; 2045 2046 /* SCTP-AUTH: Section 3.2 2047 * The CHUNKS parameter MUST be included once in the INIT or 2048 * INIT-ACK chunk if the sender wants to receive authenticated 2049 * chunks. Its maximum length is 260 bytes. 2050 */ 2051 if (260 < ntohs(param.p->length)) { 2052 sctp_process_inv_paramlength(asoc, param.p, 2053 chunk, err_chunk); 2054 retval = SCTP_IERROR_ABORT; 2055 } 2056 break; 2057 2058 case SCTP_PARAM_HMAC_ALGO: 2059 if (sctp_auth_enable) 2060 break; 2061 /* Fall Through */ 2062 fallthrough: 2063 default: 2064 SCTP_DEBUG_PRINTK("Unrecognized param: %d for chunk %d.\n", 2065 ntohs(param.p->type), cid); 2066 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2067 break; 2068 } 2069 return retval; 2070 } 2071 2072 /* Verify the INIT packet before we process it. */ 2073 int sctp_verify_init(const struct sctp_association *asoc, 2074 sctp_cid_t cid, 2075 sctp_init_chunk_t *peer_init, 2076 struct sctp_chunk *chunk, 2077 struct sctp_chunk **errp) 2078 { 2079 union sctp_params param; 2080 int has_cookie = 0; 2081 int result; 2082 2083 /* Verify stream values are non-zero. */ 2084 if ((0 == peer_init->init_hdr.num_outbound_streams) || 2085 (0 == peer_init->init_hdr.num_inbound_streams) || 2086 (0 == peer_init->init_hdr.init_tag) || 2087 (SCTP_DEFAULT_MINWINDOW > ntohl(peer_init->init_hdr.a_rwnd))) { 2088 2089 return sctp_process_inv_mandatory(asoc, chunk, errp); 2090 } 2091 2092 /* Check for missing mandatory parameters. */ 2093 sctp_walk_params(param, peer_init, init_hdr.params) { 2094 2095 if (SCTP_PARAM_STATE_COOKIE == param.p->type) 2096 has_cookie = 1; 2097 2098 } /* for (loop through all parameters) */ 2099 2100 /* There is a possibility that a parameter length was bad and 2101 * in that case we would have stoped walking the parameters. 2102 * The current param.p would point at the bad one. 2103 * Current consensus on the mailing list is to generate a PROTOCOL 2104 * VIOLATION error. We build the ERROR chunk here and let the normal 2105 * error handling code build and send the packet. 2106 */ 2107 if (param.v != (void*)chunk->chunk_end) 2108 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2109 2110 /* The only missing mandatory param possible today is 2111 * the state cookie for an INIT-ACK chunk. 2112 */ 2113 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2114 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2115 chunk, errp); 2116 2117 /* Verify all the variable length parameters */ 2118 sctp_walk_params(param, peer_init, init_hdr.params) { 2119 2120 result = sctp_verify_param(asoc, param, cid, chunk, errp); 2121 switch (result) { 2122 case SCTP_IERROR_ABORT: 2123 case SCTP_IERROR_NOMEM: 2124 return 0; 2125 case SCTP_IERROR_ERROR: 2126 return 1; 2127 case SCTP_IERROR_NO_ERROR: 2128 default: 2129 break; 2130 } 2131 2132 } /* for (loop through all parameters) */ 2133 2134 return 1; 2135 } 2136 2137 /* Unpack the parameters in an INIT packet into an association. 2138 * Returns 0 on failure, else success. 2139 * FIXME: This is an association method. 2140 */ 2141 int sctp_process_init(struct sctp_association *asoc, sctp_cid_t cid, 2142 const union sctp_addr *peer_addr, 2143 sctp_init_chunk_t *peer_init, gfp_t gfp) 2144 { 2145 union sctp_params param; 2146 struct sctp_transport *transport; 2147 struct list_head *pos, *temp; 2148 char *cookie; 2149 2150 /* We must include the address that the INIT packet came from. 2151 * This is the only address that matters for an INIT packet. 2152 * When processing a COOKIE ECHO, we retrieve the from address 2153 * of the INIT from the cookie. 2154 */ 2155 2156 /* This implementation defaults to making the first transport 2157 * added as the primary transport. The source address seems to 2158 * be a a better choice than any of the embedded addresses. 2159 */ 2160 if (peer_addr) { 2161 if(!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2162 goto nomem; 2163 } 2164 2165 /* Process the initialization parameters. */ 2166 sctp_walk_params(param, peer_init, init_hdr.params) { 2167 2168 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2169 goto clean_up; 2170 } 2171 2172 /* AUTH: After processing the parameters, make sure that we 2173 * have all the required info to potentially do authentications. 2174 */ 2175 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2176 !asoc->peer.peer_hmacs)) 2177 asoc->peer.auth_capable = 0; 2178 2179 /* In a non-backward compatible mode, if the peer claims 2180 * support for ADD-IP but not AUTH, the ADD-IP spec states 2181 * that we MUST ABORT the association. Section 6. The section 2182 * also give us an option to silently ignore the packet, which 2183 * is what we'll do here. 2184 */ 2185 if (!sctp_addip_noauth && 2186 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2187 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2188 SCTP_PARAM_DEL_IP | 2189 SCTP_PARAM_SET_PRIMARY); 2190 asoc->peer.asconf_capable = 0; 2191 goto clean_up; 2192 } 2193 2194 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2195 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2196 transport = list_entry(pos, struct sctp_transport, transports); 2197 if (transport->state == SCTP_UNKNOWN) { 2198 sctp_assoc_rm_peer(asoc, transport); 2199 } 2200 } 2201 2202 /* The fixed INIT headers are always in network byte 2203 * order. 2204 */ 2205 asoc->peer.i.init_tag = 2206 ntohl(peer_init->init_hdr.init_tag); 2207 asoc->peer.i.a_rwnd = 2208 ntohl(peer_init->init_hdr.a_rwnd); 2209 asoc->peer.i.num_outbound_streams = 2210 ntohs(peer_init->init_hdr.num_outbound_streams); 2211 asoc->peer.i.num_inbound_streams = 2212 ntohs(peer_init->init_hdr.num_inbound_streams); 2213 asoc->peer.i.initial_tsn = 2214 ntohl(peer_init->init_hdr.initial_tsn); 2215 2216 /* Apply the upper bounds for output streams based on peer's 2217 * number of inbound streams. 2218 */ 2219 if (asoc->c.sinit_num_ostreams > 2220 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2221 asoc->c.sinit_num_ostreams = 2222 ntohs(peer_init->init_hdr.num_inbound_streams); 2223 } 2224 2225 if (asoc->c.sinit_max_instreams > 2226 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2227 asoc->c.sinit_max_instreams = 2228 ntohs(peer_init->init_hdr.num_outbound_streams); 2229 } 2230 2231 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2232 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2233 2234 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2235 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2236 2237 /* Copy cookie in case we need to resend COOKIE-ECHO. */ 2238 cookie = asoc->peer.cookie; 2239 if (cookie) { 2240 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp); 2241 if (!asoc->peer.cookie) 2242 goto clean_up; 2243 } 2244 2245 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2246 * high (for example, implementations MAY use the size of the receiver 2247 * advertised window). 2248 */ 2249 list_for_each(pos, &asoc->peer.transport_addr_list) { 2250 transport = list_entry(pos, struct sctp_transport, transports); 2251 transport->ssthresh = asoc->peer.i.a_rwnd; 2252 } 2253 2254 /* Set up the TSN tracking pieces. */ 2255 sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE, 2256 asoc->peer.i.initial_tsn); 2257 2258 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2259 * 2260 * The stream sequence number in all the streams shall start 2261 * from 0 when the association is established. Also, when the 2262 * stream sequence number reaches the value 65535 the next 2263 * stream sequence number shall be set to 0. 2264 */ 2265 2266 /* Allocate storage for the negotiated streams if it is not a temporary 2267 * association. 2268 */ 2269 if (!asoc->temp) { 2270 int error; 2271 2272 asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams, 2273 asoc->c.sinit_num_ostreams, gfp); 2274 if (!asoc->ssnmap) 2275 goto clean_up; 2276 2277 error = sctp_assoc_set_id(asoc, gfp); 2278 if (error) 2279 goto clean_up; 2280 } 2281 2282 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2283 * 2284 * When an endpoint has an ASCONF signaled change to be sent to the 2285 * remote endpoint it should do the following: 2286 * ... 2287 * A2) A serial number should be assigned to the Chunk. The serial 2288 * number should be a monotonically increasing number. All serial 2289 * numbers are defined to be initialized at the start of the 2290 * association to the same value as the Initial TSN. 2291 */ 2292 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2293 return 1; 2294 2295 clean_up: 2296 /* Release the transport structures. */ 2297 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2298 transport = list_entry(pos, struct sctp_transport, transports); 2299 list_del_init(pos); 2300 sctp_transport_free(transport); 2301 } 2302 2303 asoc->peer.transport_count = 0; 2304 2305 nomem: 2306 return 0; 2307 } 2308 2309 2310 /* Update asoc with the option described in param. 2311 * 2312 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2313 * 2314 * asoc is the association to update. 2315 * param is the variable length parameter to use for update. 2316 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2317 * If the current packet is an INIT we want to minimize the amount of 2318 * work we do. In particular, we should not build transport 2319 * structures for the addresses. 2320 */ 2321 static int sctp_process_param(struct sctp_association *asoc, 2322 union sctp_params param, 2323 const union sctp_addr *peer_addr, 2324 gfp_t gfp) 2325 { 2326 union sctp_addr addr; 2327 int i; 2328 __u16 sat; 2329 int retval = 1; 2330 sctp_scope_t scope; 2331 time_t stale; 2332 struct sctp_af *af; 2333 union sctp_addr_param *addr_param; 2334 struct sctp_transport *t; 2335 2336 /* We maintain all INIT parameters in network byte order all the 2337 * time. This allows us to not worry about whether the parameters 2338 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2339 */ 2340 switch (param.p->type) { 2341 case SCTP_PARAM_IPV6_ADDRESS: 2342 if (PF_INET6 != asoc->base.sk->sk_family) 2343 break; 2344 /* Fall through. */ 2345 case SCTP_PARAM_IPV4_ADDRESS: 2346 af = sctp_get_af_specific(param_type2af(param.p->type)); 2347 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); 2348 scope = sctp_scope(peer_addr); 2349 if (sctp_in_scope(&addr, scope)) 2350 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2351 return 0; 2352 break; 2353 2354 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2355 if (!sctp_cookie_preserve_enable) 2356 break; 2357 2358 stale = ntohl(param.life->lifespan_increment); 2359 2360 /* Suggested Cookie Life span increment's unit is msec, 2361 * (1/1000sec). 2362 */ 2363 asoc->cookie_life.tv_sec += stale / 1000; 2364 asoc->cookie_life.tv_usec += (stale % 1000) * 1000; 2365 break; 2366 2367 case SCTP_PARAM_HOST_NAME_ADDRESS: 2368 SCTP_DEBUG_PRINTK("unimplemented SCTP_HOST_NAME_ADDRESS\n"); 2369 break; 2370 2371 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2372 /* Turn off the default values first so we'll know which 2373 * ones are really set by the peer. 2374 */ 2375 asoc->peer.ipv4_address = 0; 2376 asoc->peer.ipv6_address = 0; 2377 2378 /* Assume that peer supports the address family 2379 * by which it sends a packet. 2380 */ 2381 if (peer_addr->sa.sa_family == AF_INET6) 2382 asoc->peer.ipv6_address = 1; 2383 else if (peer_addr->sa.sa_family == AF_INET) 2384 asoc->peer.ipv4_address = 1; 2385 2386 /* Cycle through address types; avoid divide by 0. */ 2387 sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2388 if (sat) 2389 sat /= sizeof(__u16); 2390 2391 for (i = 0; i < sat; ++i) { 2392 switch (param.sat->types[i]) { 2393 case SCTP_PARAM_IPV4_ADDRESS: 2394 asoc->peer.ipv4_address = 1; 2395 break; 2396 2397 case SCTP_PARAM_IPV6_ADDRESS: 2398 asoc->peer.ipv6_address = 1; 2399 break; 2400 2401 case SCTP_PARAM_HOST_NAME_ADDRESS: 2402 asoc->peer.hostname_address = 1; 2403 break; 2404 2405 default: /* Just ignore anything else. */ 2406 break; 2407 } 2408 } 2409 break; 2410 2411 case SCTP_PARAM_STATE_COOKIE: 2412 asoc->peer.cookie_len = 2413 ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2414 asoc->peer.cookie = param.cookie->body; 2415 break; 2416 2417 case SCTP_PARAM_HEARTBEAT_INFO: 2418 /* Would be odd to receive, but it causes no problems. */ 2419 break; 2420 2421 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2422 /* Rejected during verify stage. */ 2423 break; 2424 2425 case SCTP_PARAM_ECN_CAPABLE: 2426 asoc->peer.ecn_capable = 1; 2427 break; 2428 2429 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2430 asoc->peer.adaptation_ind = param.aind->adaptation_ind; 2431 break; 2432 2433 case SCTP_PARAM_SET_PRIMARY: 2434 addr_param = param.v + sizeof(sctp_addip_param_t); 2435 2436 af = sctp_get_af_specific(param_type2af(param.p->type)); 2437 af->from_addr_param(&addr, addr_param, 2438 htons(asoc->peer.port), 0); 2439 2440 /* if the address is invalid, we can't process it. 2441 * XXX: see spec for what to do. 2442 */ 2443 if (!af->addr_valid(&addr, NULL, NULL)) 2444 break; 2445 2446 t = sctp_assoc_lookup_paddr(asoc, &addr); 2447 if (!t) 2448 break; 2449 2450 sctp_assoc_set_primary(asoc, t); 2451 break; 2452 2453 case SCTP_PARAM_SUPPORTED_EXT: 2454 sctp_process_ext_param(asoc, param); 2455 break; 2456 2457 case SCTP_PARAM_FWD_TSN_SUPPORT: 2458 if (sctp_prsctp_enable) { 2459 asoc->peer.prsctp_capable = 1; 2460 break; 2461 } 2462 /* Fall Through */ 2463 goto fall_through; 2464 2465 case SCTP_PARAM_RANDOM: 2466 if (!sctp_auth_enable) 2467 goto fall_through; 2468 2469 /* Save peer's random parameter */ 2470 asoc->peer.peer_random = kmemdup(param.p, 2471 ntohs(param.p->length), gfp); 2472 if (!asoc->peer.peer_random) { 2473 retval = 0; 2474 break; 2475 } 2476 break; 2477 2478 case SCTP_PARAM_HMAC_ALGO: 2479 if (!sctp_auth_enable) 2480 goto fall_through; 2481 2482 /* Save peer's HMAC list */ 2483 asoc->peer.peer_hmacs = kmemdup(param.p, 2484 ntohs(param.p->length), gfp); 2485 if (!asoc->peer.peer_hmacs) { 2486 retval = 0; 2487 break; 2488 } 2489 2490 /* Set the default HMAC the peer requested*/ 2491 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2492 break; 2493 2494 case SCTP_PARAM_CHUNKS: 2495 if (!sctp_auth_enable) 2496 goto fall_through; 2497 2498 asoc->peer.peer_chunks = kmemdup(param.p, 2499 ntohs(param.p->length), gfp); 2500 if (!asoc->peer.peer_chunks) 2501 retval = 0; 2502 break; 2503 fall_through: 2504 default: 2505 /* Any unrecognized parameters should have been caught 2506 * and handled by sctp_verify_param() which should be 2507 * called prior to this routine. Simply log the error 2508 * here. 2509 */ 2510 SCTP_DEBUG_PRINTK("Ignoring param: %d for association %p.\n", 2511 ntohs(param.p->type), asoc); 2512 break; 2513 } 2514 2515 return retval; 2516 } 2517 2518 /* Select a new verification tag. */ 2519 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2520 { 2521 /* I believe that this random number generator complies with RFC1750. 2522 * A tag of 0 is reserved for special cases (e.g. INIT). 2523 */ 2524 __u32 x; 2525 2526 do { 2527 get_random_bytes(&x, sizeof(__u32)); 2528 } while (x == 0); 2529 2530 return x; 2531 } 2532 2533 /* Select an initial TSN to send during startup. */ 2534 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2535 { 2536 __u32 retval; 2537 2538 get_random_bytes(&retval, sizeof(__u32)); 2539 return retval; 2540 } 2541 2542 /* 2543 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2544 * 0 1 2 3 2545 * 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 2546 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2547 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2548 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2549 * | Serial Number | 2550 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2551 * | Address Parameter | 2552 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2553 * | ASCONF Parameter #1 | 2554 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2555 * \ \ 2556 * / .... / 2557 * \ \ 2558 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2559 * | ASCONF Parameter #N | 2560 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2561 * 2562 * Address Parameter and other parameter will not be wrapped in this function 2563 */ 2564 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2565 union sctp_addr *addr, 2566 int vparam_len) 2567 { 2568 sctp_addiphdr_t asconf; 2569 struct sctp_chunk *retval; 2570 int length = sizeof(asconf) + vparam_len; 2571 union sctp_addr_param addrparam; 2572 int addrlen; 2573 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2574 2575 addrlen = af->to_addr_param(addr, &addrparam); 2576 if (!addrlen) 2577 return NULL; 2578 length += addrlen; 2579 2580 /* Create the chunk. */ 2581 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF, 0, length); 2582 if (!retval) 2583 return NULL; 2584 2585 asconf.serial = htonl(asoc->addip_serial++); 2586 2587 retval->subh.addip_hdr = 2588 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2589 retval->param_hdr.v = 2590 sctp_addto_chunk(retval, addrlen, &addrparam); 2591 2592 return retval; 2593 } 2594 2595 /* ADDIP 2596 * 3.2.1 Add IP Address 2597 * 0 1 2 3 2598 * 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 2599 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2600 * | Type = 0xC001 | Length = Variable | 2601 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2602 * | ASCONF-Request Correlation ID | 2603 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2604 * | Address Parameter | 2605 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2606 * 2607 * 3.2.2 Delete IP Address 2608 * 0 1 2 3 2609 * 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 2610 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2611 * | Type = 0xC002 | Length = Variable | 2612 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2613 * | ASCONF-Request Correlation ID | 2614 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2615 * | Address Parameter | 2616 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2617 * 2618 */ 2619 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2620 union sctp_addr *laddr, 2621 struct sockaddr *addrs, 2622 int addrcnt, 2623 __be16 flags) 2624 { 2625 sctp_addip_param_t param; 2626 struct sctp_chunk *retval; 2627 union sctp_addr_param addr_param; 2628 union sctp_addr *addr; 2629 void *addr_buf; 2630 struct sctp_af *af; 2631 int paramlen = sizeof(param); 2632 int addr_param_len = 0; 2633 int totallen = 0; 2634 int i; 2635 2636 /* Get total length of all the address parameters. */ 2637 addr_buf = addrs; 2638 for (i = 0; i < addrcnt; i++) { 2639 addr = (union sctp_addr *)addr_buf; 2640 af = sctp_get_af_specific(addr->v4.sin_family); 2641 addr_param_len = af->to_addr_param(addr, &addr_param); 2642 2643 totallen += paramlen; 2644 totallen += addr_param_len; 2645 2646 addr_buf += af->sockaddr_len; 2647 } 2648 2649 /* Create an asconf chunk with the required length. */ 2650 retval = sctp_make_asconf(asoc, laddr, totallen); 2651 if (!retval) 2652 return NULL; 2653 2654 /* Add the address parameters to the asconf chunk. */ 2655 addr_buf = addrs; 2656 for (i = 0; i < addrcnt; i++) { 2657 addr = (union sctp_addr *)addr_buf; 2658 af = sctp_get_af_specific(addr->v4.sin_family); 2659 addr_param_len = af->to_addr_param(addr, &addr_param); 2660 param.param_hdr.type = flags; 2661 param.param_hdr.length = htons(paramlen + addr_param_len); 2662 param.crr_id = i; 2663 2664 sctp_addto_chunk(retval, paramlen, ¶m); 2665 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2666 2667 addr_buf += af->sockaddr_len; 2668 } 2669 return retval; 2670 } 2671 2672 /* ADDIP 2673 * 3.2.4 Set Primary IP Address 2674 * 0 1 2 3 2675 * 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 2676 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2677 * | Type =0xC004 | Length = Variable | 2678 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2679 * | ASCONF-Request Correlation ID | 2680 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2681 * | Address Parameter | 2682 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2683 * 2684 * Create an ASCONF chunk with Set Primary IP address parameter. 2685 */ 2686 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2687 union sctp_addr *addr) 2688 { 2689 sctp_addip_param_t param; 2690 struct sctp_chunk *retval; 2691 int len = sizeof(param); 2692 union sctp_addr_param addrparam; 2693 int addrlen; 2694 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2695 2696 addrlen = af->to_addr_param(addr, &addrparam); 2697 if (!addrlen) 2698 return NULL; 2699 len += addrlen; 2700 2701 /* Create the chunk and make asconf header. */ 2702 retval = sctp_make_asconf(asoc, addr, len); 2703 if (!retval) 2704 return NULL; 2705 2706 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2707 param.param_hdr.length = htons(len); 2708 param.crr_id = 0; 2709 2710 sctp_addto_chunk(retval, sizeof(param), ¶m); 2711 sctp_addto_chunk(retval, addrlen, &addrparam); 2712 2713 return retval; 2714 } 2715 2716 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2717 * 0 1 2 3 2718 * 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 2719 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2720 * | Type = 0x80 | Chunk Flags | Chunk Length | 2721 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2722 * | Serial Number | 2723 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2724 * | ASCONF Parameter Response#1 | 2725 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2726 * \ \ 2727 * / .... / 2728 * \ \ 2729 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2730 * | ASCONF Parameter Response#N | 2731 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2732 * 2733 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2734 */ 2735 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2736 __u32 serial, int vparam_len) 2737 { 2738 sctp_addiphdr_t asconf; 2739 struct sctp_chunk *retval; 2740 int length = sizeof(asconf) + vparam_len; 2741 2742 /* Create the chunk. */ 2743 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF_ACK, 0, length); 2744 if (!retval) 2745 return NULL; 2746 2747 asconf.serial = htonl(serial); 2748 2749 retval->subh.addip_hdr = 2750 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2751 2752 return retval; 2753 } 2754 2755 /* Add response parameters to an ASCONF_ACK chunk. */ 2756 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2757 __be16 err_code, sctp_addip_param_t *asconf_param) 2758 { 2759 sctp_addip_param_t ack_param; 2760 sctp_errhdr_t err_param; 2761 int asconf_param_len = 0; 2762 int err_param_len = 0; 2763 __be16 response_type; 2764 2765 if (SCTP_ERROR_NO_ERROR == err_code) { 2766 response_type = SCTP_PARAM_SUCCESS_REPORT; 2767 } else { 2768 response_type = SCTP_PARAM_ERR_CAUSE; 2769 err_param_len = sizeof(err_param); 2770 if (asconf_param) 2771 asconf_param_len = 2772 ntohs(asconf_param->param_hdr.length); 2773 } 2774 2775 /* Add Success Indication or Error Cause Indication parameter. */ 2776 ack_param.param_hdr.type = response_type; 2777 ack_param.param_hdr.length = htons(sizeof(ack_param) + 2778 err_param_len + 2779 asconf_param_len); 2780 ack_param.crr_id = crr_id; 2781 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 2782 2783 if (SCTP_ERROR_NO_ERROR == err_code) 2784 return; 2785 2786 /* Add Error Cause parameter. */ 2787 err_param.cause = err_code; 2788 err_param.length = htons(err_param_len + asconf_param_len); 2789 sctp_addto_chunk(chunk, err_param_len, &err_param); 2790 2791 /* Add the failed TLV copied from ASCONF chunk. */ 2792 if (asconf_param) 2793 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 2794 } 2795 2796 /* Process a asconf parameter. */ 2797 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 2798 struct sctp_chunk *asconf, 2799 sctp_addip_param_t *asconf_param) 2800 { 2801 struct sctp_transport *peer; 2802 struct sctp_af *af; 2803 union sctp_addr addr; 2804 union sctp_addr_param *addr_param; 2805 2806 addr_param = (union sctp_addr_param *) 2807 ((void *)asconf_param + sizeof(sctp_addip_param_t)); 2808 2809 af = sctp_get_af_specific(param_type2af(addr_param->v4.param_hdr.type)); 2810 if (unlikely(!af)) 2811 return SCTP_ERROR_INV_PARAM; 2812 2813 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); 2814 2815 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 2816 * or multicast address. 2817 * (note: wildcard is permitted and requires special handling so 2818 * make sure we check for that) 2819 */ 2820 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 2821 return SCTP_ERROR_INV_PARAM; 2822 2823 switch (asconf_param->param_hdr.type) { 2824 case SCTP_PARAM_ADD_IP: 2825 /* Section 4.2.1: 2826 * If the address 0.0.0.0 or ::0 is provided, the source 2827 * address of the packet MUST be added. 2828 */ 2829 if (af->is_any(&addr)) 2830 memcpy(&addr, &asconf->source, sizeof(addr)); 2831 2832 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 2833 * request and does not have the local resources to add this 2834 * new address to the association, it MUST return an Error 2835 * Cause TLV set to the new error code 'Operation Refused 2836 * Due to Resource Shortage'. 2837 */ 2838 2839 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 2840 if (!peer) 2841 return SCTP_ERROR_RSRC_LOW; 2842 2843 /* Start the heartbeat timer. */ 2844 if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer))) 2845 sctp_transport_hold(peer); 2846 break; 2847 case SCTP_PARAM_DEL_IP: 2848 /* ADDIP 4.3 D7) If a request is received to delete the 2849 * last remaining IP address of a peer endpoint, the receiver 2850 * MUST send an Error Cause TLV with the error cause set to the 2851 * new error code 'Request to Delete Last Remaining IP Address'. 2852 */ 2853 if (asoc->peer.transport_count == 1) 2854 return SCTP_ERROR_DEL_LAST_IP; 2855 2856 /* ADDIP 4.3 D8) If a request is received to delete an IP 2857 * address which is also the source address of the IP packet 2858 * which contained the ASCONF chunk, the receiver MUST reject 2859 * this request. To reject the request the receiver MUST send 2860 * an Error Cause TLV set to the new error code 'Request to 2861 * Delete Source IP Address' 2862 */ 2863 if (sctp_cmp_addr_exact(sctp_source(asconf), &addr)) 2864 return SCTP_ERROR_DEL_SRC_IP; 2865 2866 /* Section 4.2.2 2867 * If the address 0.0.0.0 or ::0 is provided, all 2868 * addresses of the peer except the source address of the 2869 * packet MUST be deleted. 2870 */ 2871 if (af->is_any(&addr)) { 2872 sctp_assoc_set_primary(asoc, asconf->transport); 2873 sctp_assoc_del_nonprimary_peers(asoc, 2874 asconf->transport); 2875 } else 2876 sctp_assoc_del_peer(asoc, &addr); 2877 break; 2878 case SCTP_PARAM_SET_PRIMARY: 2879 /* ADDIP Section 4.2.4 2880 * If the address 0.0.0.0 or ::0 is provided, the receiver 2881 * MAY mark the source address of the packet as its 2882 * primary. 2883 */ 2884 if (af->is_any(&addr)) 2885 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr)); 2886 2887 peer = sctp_assoc_lookup_paddr(asoc, &addr); 2888 if (!peer) 2889 return SCTP_ERROR_INV_PARAM; 2890 2891 sctp_assoc_set_primary(asoc, peer); 2892 break; 2893 default: 2894 return SCTP_ERROR_INV_PARAM; 2895 break; 2896 } 2897 2898 return SCTP_ERROR_NO_ERROR; 2899 } 2900 2901 /* Verify the ASCONF packet before we process it. */ 2902 int sctp_verify_asconf(const struct sctp_association *asoc, 2903 struct sctp_paramhdr *param_hdr, void *chunk_end, 2904 struct sctp_paramhdr **errp) { 2905 sctp_addip_param_t *asconf_param; 2906 union sctp_params param; 2907 int length, plen; 2908 2909 param.v = (sctp_paramhdr_t *) param_hdr; 2910 while (param.v <= chunk_end - sizeof(sctp_paramhdr_t)) { 2911 length = ntohs(param.p->length); 2912 *errp = param.p; 2913 2914 if (param.v > chunk_end - length || 2915 length < sizeof(sctp_paramhdr_t)) 2916 return 0; 2917 2918 switch (param.p->type) { 2919 case SCTP_PARAM_ADD_IP: 2920 case SCTP_PARAM_DEL_IP: 2921 case SCTP_PARAM_SET_PRIMARY: 2922 asconf_param = (sctp_addip_param_t *)param.v; 2923 plen = ntohs(asconf_param->param_hdr.length); 2924 if (plen < sizeof(sctp_addip_param_t) + 2925 sizeof(sctp_paramhdr_t)) 2926 return 0; 2927 break; 2928 case SCTP_PARAM_SUCCESS_REPORT: 2929 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2930 if (length != sizeof(sctp_addip_param_t)) 2931 return 0; 2932 2933 break; 2934 default: 2935 break; 2936 } 2937 2938 param.v += WORD_ROUND(length); 2939 } 2940 2941 if (param.v != chunk_end) 2942 return 0; 2943 2944 return 1; 2945 } 2946 2947 /* Process an incoming ASCONF chunk with the next expected serial no. and 2948 * return an ASCONF_ACK chunk to be sent in response. 2949 */ 2950 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 2951 struct sctp_chunk *asconf) 2952 { 2953 sctp_addiphdr_t *hdr; 2954 union sctp_addr_param *addr_param; 2955 sctp_addip_param_t *asconf_param; 2956 struct sctp_chunk *asconf_ack; 2957 2958 __be16 err_code; 2959 int length = 0; 2960 int chunk_len; 2961 __u32 serial; 2962 int all_param_pass = 1; 2963 2964 chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t); 2965 hdr = (sctp_addiphdr_t *)asconf->skb->data; 2966 serial = ntohl(hdr->serial); 2967 2968 /* Skip the addiphdr and store a pointer to address parameter. */ 2969 length = sizeof(sctp_addiphdr_t); 2970 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 2971 chunk_len -= length; 2972 2973 /* Skip the address parameter and store a pointer to the first 2974 * asconf parameter. 2975 */ 2976 length = ntohs(addr_param->v4.param_hdr.length); 2977 asconf_param = (sctp_addip_param_t *)((void *)addr_param + length); 2978 chunk_len -= length; 2979 2980 /* create an ASCONF_ACK chunk. 2981 * Based on the definitions of parameters, we know that the size of 2982 * ASCONF_ACK parameters are less than or equal to the twice of ASCONF 2983 * parameters. 2984 */ 2985 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 2); 2986 if (!asconf_ack) 2987 goto done; 2988 2989 /* Process the TLVs contained within the ASCONF chunk. */ 2990 while (chunk_len > 0) { 2991 err_code = sctp_process_asconf_param(asoc, asconf, 2992 asconf_param); 2993 /* ADDIP 4.1 A7) 2994 * If an error response is received for a TLV parameter, 2995 * all TLVs with no response before the failed TLV are 2996 * considered successful if not reported. All TLVs after 2997 * the failed response are considered unsuccessful unless 2998 * a specific success indication is present for the parameter. 2999 */ 3000 if (SCTP_ERROR_NO_ERROR != err_code) 3001 all_param_pass = 0; 3002 3003 if (!all_param_pass) 3004 sctp_add_asconf_response(asconf_ack, 3005 asconf_param->crr_id, err_code, 3006 asconf_param); 3007 3008 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3009 * an IP address sends an 'Out of Resource' in its response, it 3010 * MUST also fail any subsequent add or delete requests bundled 3011 * in the ASCONF. 3012 */ 3013 if (SCTP_ERROR_RSRC_LOW == err_code) 3014 goto done; 3015 3016 /* Move to the next ASCONF param. */ 3017 length = ntohs(asconf_param->param_hdr.length); 3018 asconf_param = (sctp_addip_param_t *)((void *)asconf_param + 3019 length); 3020 chunk_len -= length; 3021 } 3022 3023 done: 3024 asoc->peer.addip_serial++; 3025 3026 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3027 * after freeing the reference to old asconf ack if any. 3028 */ 3029 if (asconf_ack) { 3030 sctp_chunk_hold(asconf_ack); 3031 list_add_tail(&asconf_ack->transmitted_list, 3032 &asoc->asconf_ack_list); 3033 } 3034 3035 return asconf_ack; 3036 } 3037 3038 /* Process a asconf parameter that is successfully acked. */ 3039 static int sctp_asconf_param_success(struct sctp_association *asoc, 3040 sctp_addip_param_t *asconf_param) 3041 { 3042 struct sctp_af *af; 3043 union sctp_addr addr; 3044 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3045 union sctp_addr_param *addr_param; 3046 struct list_head *pos; 3047 struct sctp_transport *transport; 3048 struct sctp_sockaddr_entry *saddr; 3049 int retval = 0; 3050 3051 addr_param = (union sctp_addr_param *) 3052 ((void *)asconf_param + sizeof(sctp_addip_param_t)); 3053 3054 /* We have checked the packet before, so we do not check again. */ 3055 af = sctp_get_af_specific(param_type2af(addr_param->v4.param_hdr.type)); 3056 af->from_addr_param(&addr, addr_param, htons(bp->port), 0); 3057 3058 switch (asconf_param->param_hdr.type) { 3059 case SCTP_PARAM_ADD_IP: 3060 /* This is always done in BH context with a socket lock 3061 * held, so the list can not change. 3062 */ 3063 local_bh_disable(); 3064 list_for_each_entry(saddr, &bp->address_list, list) { 3065 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3066 saddr->state = SCTP_ADDR_SRC; 3067 } 3068 local_bh_enable(); 3069 break; 3070 case SCTP_PARAM_DEL_IP: 3071 local_bh_disable(); 3072 retval = sctp_del_bind_addr(bp, &addr); 3073 local_bh_enable(); 3074 list_for_each(pos, &asoc->peer.transport_addr_list) { 3075 transport = list_entry(pos, struct sctp_transport, 3076 transports); 3077 dst_release(transport->dst); 3078 sctp_transport_route(transport, NULL, 3079 sctp_sk(asoc->base.sk)); 3080 } 3081 break; 3082 default: 3083 break; 3084 } 3085 3086 return retval; 3087 } 3088 3089 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3090 * for the given asconf parameter. If there is no response for this parameter, 3091 * return the error code based on the third argument 'no_err'. 3092 * ADDIP 4.1 3093 * A7) If an error response is received for a TLV parameter, all TLVs with no 3094 * response before the failed TLV are considered successful if not reported. 3095 * All TLVs after the failed response are considered unsuccessful unless a 3096 * specific success indication is present for the parameter. 3097 */ 3098 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3099 sctp_addip_param_t *asconf_param, 3100 int no_err) 3101 { 3102 sctp_addip_param_t *asconf_ack_param; 3103 sctp_errhdr_t *err_param; 3104 int length; 3105 int asconf_ack_len; 3106 __be16 err_code; 3107 3108 if (no_err) 3109 err_code = SCTP_ERROR_NO_ERROR; 3110 else 3111 err_code = SCTP_ERROR_REQ_REFUSED; 3112 3113 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3114 sizeof(sctp_chunkhdr_t); 3115 3116 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3117 * the first asconf_ack parameter. 3118 */ 3119 length = sizeof(sctp_addiphdr_t); 3120 asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data + 3121 length); 3122 asconf_ack_len -= length; 3123 3124 while (asconf_ack_len > 0) { 3125 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3126 switch(asconf_ack_param->param_hdr.type) { 3127 case SCTP_PARAM_SUCCESS_REPORT: 3128 return SCTP_ERROR_NO_ERROR; 3129 case SCTP_PARAM_ERR_CAUSE: 3130 length = sizeof(sctp_addip_param_t); 3131 err_param = (sctp_errhdr_t *) 3132 ((void *)asconf_ack_param + length); 3133 asconf_ack_len -= length; 3134 if (asconf_ack_len > 0) 3135 return err_param->cause; 3136 else 3137 return SCTP_ERROR_INV_PARAM; 3138 break; 3139 default: 3140 return SCTP_ERROR_INV_PARAM; 3141 } 3142 } 3143 3144 length = ntohs(asconf_ack_param->param_hdr.length); 3145 asconf_ack_param = (sctp_addip_param_t *) 3146 ((void *)asconf_ack_param + length); 3147 asconf_ack_len -= length; 3148 } 3149 3150 return err_code; 3151 } 3152 3153 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3154 int sctp_process_asconf_ack(struct sctp_association *asoc, 3155 struct sctp_chunk *asconf_ack) 3156 { 3157 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3158 union sctp_addr_param *addr_param; 3159 sctp_addip_param_t *asconf_param; 3160 int length = 0; 3161 int asconf_len = asconf->skb->len; 3162 int all_param_pass = 0; 3163 int no_err = 1; 3164 int retval = 0; 3165 __be16 err_code = SCTP_ERROR_NO_ERROR; 3166 3167 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3168 * a pointer to address parameter. 3169 */ 3170 length = sizeof(sctp_addip_chunk_t); 3171 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3172 asconf_len -= length; 3173 3174 /* Skip the address parameter in the last asconf sent and store a 3175 * pointer to the first asconf parameter. 3176 */ 3177 length = ntohs(addr_param->v4.param_hdr.length); 3178 asconf_param = (sctp_addip_param_t *)((void *)addr_param + length); 3179 asconf_len -= length; 3180 3181 /* ADDIP 4.1 3182 * A8) If there is no response(s) to specific TLV parameter(s), and no 3183 * failures are indicated, then all request(s) are considered 3184 * successful. 3185 */ 3186 if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t)) 3187 all_param_pass = 1; 3188 3189 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3190 while (asconf_len > 0) { 3191 if (all_param_pass) 3192 err_code = SCTP_ERROR_NO_ERROR; 3193 else { 3194 err_code = sctp_get_asconf_response(asconf_ack, 3195 asconf_param, 3196 no_err); 3197 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3198 no_err = 0; 3199 } 3200 3201 switch (err_code) { 3202 case SCTP_ERROR_NO_ERROR: 3203 retval = sctp_asconf_param_success(asoc, asconf_param); 3204 break; 3205 3206 case SCTP_ERROR_RSRC_LOW: 3207 retval = 1; 3208 break; 3209 3210 case SCTP_ERROR_INV_PARAM: 3211 /* Disable sending this type of asconf parameter in 3212 * future. 3213 */ 3214 asoc->peer.addip_disabled_mask |= 3215 asconf_param->param_hdr.type; 3216 break; 3217 3218 case SCTP_ERROR_REQ_REFUSED: 3219 case SCTP_ERROR_DEL_LAST_IP: 3220 case SCTP_ERROR_DEL_SRC_IP: 3221 default: 3222 break; 3223 } 3224 3225 /* Skip the processed asconf parameter and move to the next 3226 * one. 3227 */ 3228 length = ntohs(asconf_param->param_hdr.length); 3229 asconf_param = (sctp_addip_param_t *)((void *)asconf_param + 3230 length); 3231 asconf_len -= length; 3232 } 3233 3234 /* Free the cached last sent asconf chunk. */ 3235 list_del_init(&asconf->transmitted_list); 3236 sctp_chunk_free(asconf); 3237 asoc->addip_last_asconf = NULL; 3238 3239 /* Send the next asconf chunk from the addip chunk queue. */ 3240 if (!list_empty(&asoc->addip_chunk_list)) { 3241 struct list_head *entry = asoc->addip_chunk_list.next; 3242 asconf = list_entry(entry, struct sctp_chunk, list); 3243 3244 list_del_init(entry); 3245 3246 /* Hold the chunk until an ASCONF_ACK is received. */ 3247 sctp_chunk_hold(asconf); 3248 if (sctp_primitive_ASCONF(asoc, asconf)) 3249 sctp_chunk_free(asconf); 3250 else 3251 asoc->addip_last_asconf = asconf; 3252 } 3253 3254 return retval; 3255 } 3256 3257 /* Make a FWD TSN chunk. */ 3258 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3259 __u32 new_cum_tsn, size_t nstreams, 3260 struct sctp_fwdtsn_skip *skiplist) 3261 { 3262 struct sctp_chunk *retval = NULL; 3263 struct sctp_fwdtsn_chunk *ftsn_chunk; 3264 struct sctp_fwdtsn_hdr ftsn_hdr; 3265 struct sctp_fwdtsn_skip skip; 3266 size_t hint; 3267 int i; 3268 3269 hint = (nstreams + 1) * sizeof(__u32); 3270 3271 retval = sctp_make_chunk(asoc, SCTP_CID_FWD_TSN, 0, hint); 3272 3273 if (!retval) 3274 return NULL; 3275 3276 ftsn_chunk = (struct sctp_fwdtsn_chunk *)retval->subh.fwdtsn_hdr; 3277 3278 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3279 retval->subh.fwdtsn_hdr = 3280 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3281 3282 for (i = 0; i < nstreams; i++) { 3283 skip.stream = skiplist[i].stream; 3284 skip.ssn = skiplist[i].ssn; 3285 sctp_addto_chunk(retval, sizeof(skip), &skip); 3286 } 3287 3288 return retval; 3289 } 3290