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 struct sctp_chunk *sctp_make_violation_paramlen( 1016 const struct sctp_association *asoc, 1017 const struct sctp_chunk *chunk, 1018 struct sctp_paramhdr *param) 1019 { 1020 struct sctp_chunk *retval; 1021 static const char error[] = "The following parameter had invalid length:"; 1022 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t) + 1023 sizeof(sctp_paramhdr_t); 1024 1025 retval = sctp_make_abort(asoc, chunk, payload_len); 1026 if (!retval) 1027 goto nodata; 1028 1029 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, 1030 sizeof(error) + sizeof(sctp_paramhdr_t)); 1031 sctp_addto_chunk(retval, sizeof(error), error); 1032 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), param); 1033 1034 nodata: 1035 return retval; 1036 } 1037 1038 /* Make a HEARTBEAT chunk. */ 1039 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1040 const struct sctp_transport *transport, 1041 const void *payload, const size_t paylen) 1042 { 1043 struct sctp_chunk *retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT, 1044 0, paylen); 1045 1046 if (!retval) 1047 goto nodata; 1048 1049 /* Cast away the 'const', as this is just telling the chunk 1050 * what transport it belongs to. 1051 */ 1052 retval->transport = (struct sctp_transport *) transport; 1053 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1054 1055 nodata: 1056 return retval; 1057 } 1058 1059 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1060 const struct sctp_chunk *chunk, 1061 const void *payload, const size_t paylen) 1062 { 1063 struct sctp_chunk *retval; 1064 1065 retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen); 1066 if (!retval) 1067 goto nodata; 1068 1069 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1070 1071 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1072 * 1073 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1074 * HEARTBEAT ACK, * etc.) to the same destination transport 1075 * address from which it * received the DATA or control chunk 1076 * to which it is replying. 1077 * 1078 * [HBACK back to where the HEARTBEAT came from.] 1079 */ 1080 if (chunk) 1081 retval->transport = chunk->transport; 1082 1083 nodata: 1084 return retval; 1085 } 1086 1087 /* Create an Operation Error chunk with the specified space reserved. 1088 * This routine can be used for containing multiple causes in the chunk. 1089 */ 1090 static struct sctp_chunk *sctp_make_op_error_space( 1091 const struct sctp_association *asoc, 1092 const struct sctp_chunk *chunk, 1093 size_t size) 1094 { 1095 struct sctp_chunk *retval; 1096 1097 retval = sctp_make_chunk(asoc, SCTP_CID_ERROR, 0, 1098 sizeof(sctp_errhdr_t) + size); 1099 if (!retval) 1100 goto nodata; 1101 1102 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1103 * 1104 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1105 * HEARTBEAT ACK, etc.) to the same destination transport 1106 * address from which it received the DATA or control chunk 1107 * to which it is replying. 1108 * 1109 */ 1110 if (chunk) 1111 retval->transport = chunk->transport; 1112 1113 nodata: 1114 return retval; 1115 } 1116 1117 /* Create an Operation Error chunk. */ 1118 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1119 const struct sctp_chunk *chunk, 1120 __be16 cause_code, const void *payload, 1121 size_t paylen) 1122 { 1123 struct sctp_chunk *retval; 1124 1125 retval = sctp_make_op_error_space(asoc, chunk, paylen); 1126 if (!retval) 1127 goto nodata; 1128 1129 sctp_init_cause(retval, cause_code, paylen); 1130 sctp_addto_chunk(retval, paylen, payload); 1131 1132 nodata: 1133 return retval; 1134 } 1135 1136 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc) 1137 { 1138 struct sctp_chunk *retval; 1139 struct sctp_hmac *hmac_desc; 1140 struct sctp_authhdr auth_hdr; 1141 __u8 *hmac; 1142 1143 /* Get the first hmac that the peer told us to use */ 1144 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1145 if (unlikely(!hmac_desc)) 1146 return NULL; 1147 1148 retval = sctp_make_chunk(asoc, SCTP_CID_AUTH, 0, 1149 hmac_desc->hmac_len + sizeof(sctp_authhdr_t)); 1150 if (!retval) 1151 return NULL; 1152 1153 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1154 auth_hdr.shkey_id = htons(asoc->active_key_id); 1155 1156 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t), 1157 &auth_hdr); 1158 1159 hmac = skb_put(retval->skb, hmac_desc->hmac_len); 1160 memset(hmac, 0, hmac_desc->hmac_len); 1161 1162 /* Adjust the chunk header to include the empty MAC */ 1163 retval->chunk_hdr->length = 1164 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1165 retval->chunk_end = skb_tail_pointer(retval->skb); 1166 1167 return retval; 1168 } 1169 1170 1171 /******************************************************************** 1172 * 2nd Level Abstractions 1173 ********************************************************************/ 1174 1175 /* Turn an skb into a chunk. 1176 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1177 */ 1178 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1179 const struct sctp_association *asoc, 1180 struct sock *sk) 1181 { 1182 struct sctp_chunk *retval; 1183 1184 retval = kmem_cache_zalloc(sctp_chunk_cachep, GFP_ATOMIC); 1185 1186 if (!retval) 1187 goto nodata; 1188 1189 if (!sk) { 1190 SCTP_DEBUG_PRINTK("chunkifying skb %p w/o an sk\n", skb); 1191 } 1192 1193 INIT_LIST_HEAD(&retval->list); 1194 retval->skb = skb; 1195 retval->asoc = (struct sctp_association *)asoc; 1196 retval->resent = 0; 1197 retval->has_tsn = 0; 1198 retval->has_ssn = 0; 1199 retval->rtt_in_progress = 0; 1200 retval->sent_at = 0; 1201 retval->singleton = 1; 1202 retval->end_of_packet = 0; 1203 retval->ecn_ce_done = 0; 1204 retval->pdiscard = 0; 1205 1206 /* sctpimpguide-05.txt Section 2.8.2 1207 * M1) Each time a new DATA chunk is transmitted 1208 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1209 * 'TSN.Missing.Report' count will be used to determine missing chunks 1210 * and when to fast retransmit. 1211 */ 1212 retval->tsn_missing_report = 0; 1213 retval->tsn_gap_acked = 0; 1214 retval->fast_retransmit = 0; 1215 1216 /* If this is a fragmented message, track all fragments 1217 * of the message (for SEND_FAILED). 1218 */ 1219 retval->msg = NULL; 1220 1221 /* Polish the bead hole. */ 1222 INIT_LIST_HEAD(&retval->transmitted_list); 1223 INIT_LIST_HEAD(&retval->frag_list); 1224 SCTP_DBG_OBJCNT_INC(chunk); 1225 atomic_set(&retval->refcnt, 1); 1226 1227 nodata: 1228 return retval; 1229 } 1230 1231 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1232 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1233 union sctp_addr *dest) 1234 { 1235 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1236 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1237 } 1238 1239 /* Extract the source address from a chunk. */ 1240 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1241 { 1242 /* If we have a known transport, use that. */ 1243 if (chunk->transport) { 1244 return &chunk->transport->ipaddr; 1245 } else { 1246 /* Otherwise, extract it from the IP header. */ 1247 return &chunk->source; 1248 } 1249 } 1250 1251 /* Create a new chunk, setting the type and flags headers from the 1252 * arguments, reserving enough space for a 'paylen' byte payload. 1253 */ 1254 SCTP_STATIC 1255 struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc, 1256 __u8 type, __u8 flags, int paylen) 1257 { 1258 struct sctp_chunk *retval; 1259 sctp_chunkhdr_t *chunk_hdr; 1260 struct sk_buff *skb; 1261 struct sock *sk; 1262 1263 /* No need to allocate LL here, as this is only a chunk. */ 1264 skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen), 1265 GFP_ATOMIC); 1266 if (!skb) 1267 goto nodata; 1268 1269 /* Make room for the chunk header. */ 1270 chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t)); 1271 chunk_hdr->type = type; 1272 chunk_hdr->flags = flags; 1273 chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t)); 1274 1275 sk = asoc ? asoc->base.sk : NULL; 1276 retval = sctp_chunkify(skb, asoc, sk); 1277 if (!retval) { 1278 kfree_skb(skb); 1279 goto nodata; 1280 } 1281 1282 retval->chunk_hdr = chunk_hdr; 1283 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr); 1284 1285 /* Determine if the chunk needs to be authenticated */ 1286 if (sctp_auth_send_cid(type, asoc)) 1287 retval->auth = 1; 1288 1289 /* Set the skb to the belonging sock for accounting. */ 1290 skb->sk = sk; 1291 1292 return retval; 1293 nodata: 1294 return NULL; 1295 } 1296 1297 1298 /* Release the memory occupied by a chunk. */ 1299 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1300 { 1301 BUG_ON(!list_empty(&chunk->list)); 1302 list_del_init(&chunk->transmitted_list); 1303 1304 /* Free the chunk skb data and the SCTP_chunk stub itself. */ 1305 dev_kfree_skb(chunk->skb); 1306 1307 SCTP_DBG_OBJCNT_DEC(chunk); 1308 kmem_cache_free(sctp_chunk_cachep, chunk); 1309 } 1310 1311 /* Possibly, free the chunk. */ 1312 void sctp_chunk_free(struct sctp_chunk *chunk) 1313 { 1314 /* Release our reference on the message tracker. */ 1315 if (chunk->msg) 1316 sctp_datamsg_put(chunk->msg); 1317 1318 sctp_chunk_put(chunk); 1319 } 1320 1321 /* Grab a reference to the chunk. */ 1322 void sctp_chunk_hold(struct sctp_chunk *ch) 1323 { 1324 atomic_inc(&ch->refcnt); 1325 } 1326 1327 /* Release a reference to the chunk. */ 1328 void sctp_chunk_put(struct sctp_chunk *ch) 1329 { 1330 if (atomic_dec_and_test(&ch->refcnt)) 1331 sctp_chunk_destroy(ch); 1332 } 1333 1334 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1335 * enough. 1336 */ 1337 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1338 { 1339 void *target; 1340 void *padding; 1341 int chunklen = ntohs(chunk->chunk_hdr->length); 1342 int padlen = WORD_ROUND(chunklen) - chunklen; 1343 1344 padding = skb_put(chunk->skb, padlen); 1345 target = skb_put(chunk->skb, len); 1346 1347 memset(padding, 0, padlen); 1348 memcpy(target, data, len); 1349 1350 /* Adjust the chunk length field. */ 1351 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1352 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1353 1354 return target; 1355 } 1356 1357 /* Append bytes from user space to the end of a chunk. Will panic if 1358 * chunk is not big enough. 1359 * Returns a kernel err value. 1360 */ 1361 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len, 1362 struct iovec *data) 1363 { 1364 __u8 *target; 1365 int err = 0; 1366 1367 /* Make room in chunk for data. */ 1368 target = skb_put(chunk->skb, len); 1369 1370 /* Copy data (whole iovec) into chunk */ 1371 if ((err = memcpy_fromiovecend(target, data, off, len))) 1372 goto out; 1373 1374 /* Adjust the chunk length field. */ 1375 chunk->chunk_hdr->length = 1376 htons(ntohs(chunk->chunk_hdr->length) + len); 1377 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1378 1379 out: 1380 return err; 1381 } 1382 1383 /* Helper function to assign a TSN if needed. This assumes that both 1384 * the data_hdr and association have already been assigned. 1385 */ 1386 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1387 { 1388 struct sctp_datamsg *msg; 1389 struct sctp_chunk *lchunk; 1390 struct sctp_stream *stream; 1391 __u16 ssn; 1392 __u16 sid; 1393 1394 if (chunk->has_ssn) 1395 return; 1396 1397 /* All fragments will be on the same stream */ 1398 sid = ntohs(chunk->subh.data_hdr->stream); 1399 stream = &chunk->asoc->ssnmap->out; 1400 1401 /* Now assign the sequence number to the entire message. 1402 * All fragments must have the same stream sequence number. 1403 */ 1404 msg = chunk->msg; 1405 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1406 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1407 ssn = 0; 1408 } else { 1409 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1410 ssn = sctp_ssn_next(stream, sid); 1411 else 1412 ssn = sctp_ssn_peek(stream, sid); 1413 } 1414 1415 lchunk->subh.data_hdr->ssn = htons(ssn); 1416 lchunk->has_ssn = 1; 1417 } 1418 } 1419 1420 /* Helper function to assign a TSN if needed. This assumes that both 1421 * the data_hdr and association have already been assigned. 1422 */ 1423 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1424 { 1425 if (!chunk->has_tsn) { 1426 /* This is the last possible instant to 1427 * assign a TSN. 1428 */ 1429 chunk->subh.data_hdr->tsn = 1430 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1431 chunk->has_tsn = 1; 1432 } 1433 } 1434 1435 /* Create a CLOSED association to use with an incoming packet. */ 1436 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1437 struct sctp_chunk *chunk, 1438 gfp_t gfp) 1439 { 1440 struct sctp_association *asoc; 1441 struct sk_buff *skb; 1442 sctp_scope_t scope; 1443 struct sctp_af *af; 1444 1445 /* Create the bare association. */ 1446 scope = sctp_scope(sctp_source(chunk)); 1447 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1448 if (!asoc) 1449 goto nodata; 1450 asoc->temp = 1; 1451 skb = chunk->skb; 1452 /* Create an entry for the source address of the packet. */ 1453 af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version)); 1454 if (unlikely(!af)) 1455 goto fail; 1456 af->from_skb(&asoc->c.peer_addr, skb, 1); 1457 nodata: 1458 return asoc; 1459 1460 fail: 1461 sctp_association_free(asoc); 1462 return NULL; 1463 } 1464 1465 /* Build a cookie representing asoc. 1466 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1467 */ 1468 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, 1469 const struct sctp_association *asoc, 1470 const struct sctp_chunk *init_chunk, 1471 int *cookie_len, 1472 const __u8 *raw_addrs, int addrs_len) 1473 { 1474 sctp_cookie_param_t *retval; 1475 struct sctp_signed_cookie *cookie; 1476 struct scatterlist sg; 1477 int headersize, bodysize; 1478 unsigned int keylen; 1479 char *key; 1480 1481 /* Header size is static data prior to the actual cookie, including 1482 * any padding. 1483 */ 1484 headersize = sizeof(sctp_paramhdr_t) + 1485 (sizeof(struct sctp_signed_cookie) - 1486 sizeof(struct sctp_cookie)); 1487 bodysize = sizeof(struct sctp_cookie) 1488 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1489 1490 /* Pad out the cookie to a multiple to make the signature 1491 * functions simpler to write. 1492 */ 1493 if (bodysize % SCTP_COOKIE_MULTIPLE) 1494 bodysize += SCTP_COOKIE_MULTIPLE 1495 - (bodysize % SCTP_COOKIE_MULTIPLE); 1496 *cookie_len = headersize + bodysize; 1497 1498 /* Clear this memory since we are sending this data structure 1499 * out on the network. 1500 */ 1501 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1502 if (!retval) 1503 goto nodata; 1504 1505 cookie = (struct sctp_signed_cookie *) retval->body; 1506 1507 /* Set up the parameter header. */ 1508 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1509 retval->p.length = htons(*cookie_len); 1510 1511 /* Copy the cookie part of the association itself. */ 1512 cookie->c = asoc->c; 1513 /* Save the raw address list length in the cookie. */ 1514 cookie->c.raw_addr_list_len = addrs_len; 1515 1516 /* Remember PR-SCTP capability. */ 1517 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1518 1519 /* Save adaptation indication in the cookie. */ 1520 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1521 1522 /* Set an expiration time for the cookie. */ 1523 do_gettimeofday(&cookie->c.expiration); 1524 TIMEVAL_ADD(asoc->cookie_life, cookie->c.expiration); 1525 1526 /* Copy the peer's init packet. */ 1527 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr, 1528 ntohs(init_chunk->chunk_hdr->length)); 1529 1530 /* Copy the raw local address list of the association. */ 1531 memcpy((__u8 *)&cookie->c.peer_init[0] + 1532 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1533 1534 if (sctp_sk(ep->base.sk)->hmac) { 1535 struct hash_desc desc; 1536 1537 /* Sign the message. */ 1538 sg_init_one(&sg, &cookie->c, bodysize); 1539 keylen = SCTP_SECRET_SIZE; 1540 key = (char *)ep->secret_key[ep->current_key]; 1541 desc.tfm = sctp_sk(ep->base.sk)->hmac; 1542 desc.flags = 0; 1543 1544 if (crypto_hash_setkey(desc.tfm, key, keylen) || 1545 crypto_hash_digest(&desc, &sg, bodysize, cookie->signature)) 1546 goto free_cookie; 1547 } 1548 1549 return retval; 1550 1551 free_cookie: 1552 kfree(retval); 1553 nodata: 1554 *cookie_len = 0; 1555 return NULL; 1556 } 1557 1558 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1559 struct sctp_association *sctp_unpack_cookie( 1560 const struct sctp_endpoint *ep, 1561 const struct sctp_association *asoc, 1562 struct sctp_chunk *chunk, gfp_t gfp, 1563 int *error, struct sctp_chunk **errp) 1564 { 1565 struct sctp_association *retval = NULL; 1566 struct sctp_signed_cookie *cookie; 1567 struct sctp_cookie *bear_cookie; 1568 int headersize, bodysize, fixed_size; 1569 __u8 *digest = ep->digest; 1570 struct scatterlist sg; 1571 unsigned int keylen, len; 1572 char *key; 1573 sctp_scope_t scope; 1574 struct sk_buff *skb = chunk->skb; 1575 struct timeval tv; 1576 struct hash_desc desc; 1577 1578 /* Header size is static data prior to the actual cookie, including 1579 * any padding. 1580 */ 1581 headersize = sizeof(sctp_chunkhdr_t) + 1582 (sizeof(struct sctp_signed_cookie) - 1583 sizeof(struct sctp_cookie)); 1584 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1585 fixed_size = headersize + sizeof(struct sctp_cookie); 1586 1587 /* Verify that the chunk looks like it even has a cookie. 1588 * There must be enough room for our cookie and our peer's 1589 * INIT chunk. 1590 */ 1591 len = ntohs(chunk->chunk_hdr->length); 1592 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1593 goto malformed; 1594 1595 /* Verify that the cookie has been padded out. */ 1596 if (bodysize % SCTP_COOKIE_MULTIPLE) 1597 goto malformed; 1598 1599 /* Process the cookie. */ 1600 cookie = chunk->subh.cookie_hdr; 1601 bear_cookie = &cookie->c; 1602 1603 if (!sctp_sk(ep->base.sk)->hmac) 1604 goto no_hmac; 1605 1606 /* Check the signature. */ 1607 keylen = SCTP_SECRET_SIZE; 1608 sg_init_one(&sg, bear_cookie, bodysize); 1609 key = (char *)ep->secret_key[ep->current_key]; 1610 desc.tfm = sctp_sk(ep->base.sk)->hmac; 1611 desc.flags = 0; 1612 1613 memset(digest, 0x00, SCTP_SIGNATURE_SIZE); 1614 if (crypto_hash_setkey(desc.tfm, key, keylen) || 1615 crypto_hash_digest(&desc, &sg, bodysize, digest)) { 1616 *error = -SCTP_IERROR_NOMEM; 1617 goto fail; 1618 } 1619 1620 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1621 /* Try the previous key. */ 1622 key = (char *)ep->secret_key[ep->last_key]; 1623 memset(digest, 0x00, SCTP_SIGNATURE_SIZE); 1624 if (crypto_hash_setkey(desc.tfm, key, keylen) || 1625 crypto_hash_digest(&desc, &sg, bodysize, digest)) { 1626 *error = -SCTP_IERROR_NOMEM; 1627 goto fail; 1628 } 1629 1630 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1631 /* Yikes! Still bad signature! */ 1632 *error = -SCTP_IERROR_BAD_SIG; 1633 goto fail; 1634 } 1635 } 1636 1637 no_hmac: 1638 /* IG Section 2.35.2: 1639 * 3) Compare the port numbers and the verification tag contained 1640 * within the COOKIE ECHO chunk to the actual port numbers and the 1641 * verification tag within the SCTP common header of the received 1642 * packet. If these values do not match the packet MUST be silently 1643 * discarded, 1644 */ 1645 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1646 *error = -SCTP_IERROR_BAD_TAG; 1647 goto fail; 1648 } 1649 1650 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1651 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1652 *error = -SCTP_IERROR_BAD_PORTS; 1653 goto fail; 1654 } 1655 1656 /* Check to see if the cookie is stale. If there is already 1657 * an association, there is no need to check cookie's expiration 1658 * for init collision case of lost COOKIE ACK. 1659 * If skb has been timestamped, then use the stamp, otherwise 1660 * use current time. This introduces a small possibility that 1661 * that a cookie may be considered expired, but his would only slow 1662 * down the new association establishment instead of every packet. 1663 */ 1664 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1665 skb_get_timestamp(skb, &tv); 1666 else 1667 do_gettimeofday(&tv); 1668 1669 if (!asoc && tv_lt(bear_cookie->expiration, tv)) { 1670 /* 1671 * Section 3.3.10.3 Stale Cookie Error (3) 1672 * 1673 * Cause of error 1674 * --------------- 1675 * Stale Cookie Error: Indicates the receipt of a valid State 1676 * Cookie that has expired. 1677 */ 1678 len = ntohs(chunk->chunk_hdr->length); 1679 *errp = sctp_make_op_error_space(asoc, chunk, len); 1680 if (*errp) { 1681 suseconds_t usecs = (tv.tv_sec - 1682 bear_cookie->expiration.tv_sec) * 1000000L + 1683 tv.tv_usec - bear_cookie->expiration.tv_usec; 1684 __be32 n = htonl(usecs); 1685 1686 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE, 1687 sizeof(n)); 1688 sctp_addto_chunk(*errp, sizeof(n), &n); 1689 *error = -SCTP_IERROR_STALE_COOKIE; 1690 } else 1691 *error = -SCTP_IERROR_NOMEM; 1692 1693 goto fail; 1694 } 1695 1696 /* Make a new base association. */ 1697 scope = sctp_scope(sctp_source(chunk)); 1698 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1699 if (!retval) { 1700 *error = -SCTP_IERROR_NOMEM; 1701 goto fail; 1702 } 1703 1704 /* Set up our peer's port number. */ 1705 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1706 1707 /* Populate the association from the cookie. */ 1708 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1709 1710 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1711 GFP_ATOMIC) < 0) { 1712 *error = -SCTP_IERROR_NOMEM; 1713 goto fail; 1714 } 1715 1716 /* Also, add the destination address. */ 1717 if (list_empty(&retval->base.bind_addr.address_list)) { 1718 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1719 SCTP_ADDR_SRC, GFP_ATOMIC); 1720 } 1721 1722 retval->next_tsn = retval->c.initial_tsn; 1723 retval->ctsn_ack_point = retval->next_tsn - 1; 1724 retval->addip_serial = retval->c.initial_tsn; 1725 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1726 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1727 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1728 1729 /* The INIT stuff will be done by the side effects. */ 1730 return retval; 1731 1732 fail: 1733 if (retval) 1734 sctp_association_free(retval); 1735 1736 return NULL; 1737 1738 malformed: 1739 /* Yikes! The packet is either corrupt or deliberately 1740 * malformed. 1741 */ 1742 *error = -SCTP_IERROR_MALFORMED; 1743 goto fail; 1744 } 1745 1746 /******************************************************************** 1747 * 3rd Level Abstractions 1748 ********************************************************************/ 1749 1750 struct __sctp_missing { 1751 __be32 num_missing; 1752 __be16 type; 1753 } __attribute__((packed)); 1754 1755 /* 1756 * Report a missing mandatory parameter. 1757 */ 1758 static int sctp_process_missing_param(const struct sctp_association *asoc, 1759 sctp_param_t paramtype, 1760 struct sctp_chunk *chunk, 1761 struct sctp_chunk **errp) 1762 { 1763 struct __sctp_missing report; 1764 __u16 len; 1765 1766 len = WORD_ROUND(sizeof(report)); 1767 1768 /* Make an ERROR chunk, preparing enough room for 1769 * returning multiple unknown parameters. 1770 */ 1771 if (!*errp) 1772 *errp = sctp_make_op_error_space(asoc, chunk, len); 1773 1774 if (*errp) { 1775 report.num_missing = htonl(1); 1776 report.type = paramtype; 1777 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1778 sizeof(report)); 1779 sctp_addto_chunk(*errp, sizeof(report), &report); 1780 } 1781 1782 /* Stop processing this chunk. */ 1783 return 0; 1784 } 1785 1786 /* Report an Invalid Mandatory Parameter. */ 1787 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1788 struct sctp_chunk *chunk, 1789 struct sctp_chunk **errp) 1790 { 1791 /* Invalid Mandatory Parameter Error has no payload. */ 1792 1793 if (!*errp) 1794 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1795 1796 if (*errp) 1797 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1798 1799 /* Stop processing this chunk. */ 1800 return 0; 1801 } 1802 1803 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1804 struct sctp_paramhdr *param, 1805 const struct sctp_chunk *chunk, 1806 struct sctp_chunk **errp) 1807 { 1808 /* This is a fatal error. Any accumulated non-fatal errors are 1809 * not reported. 1810 */ 1811 if (*errp) 1812 sctp_chunk_free(*errp); 1813 1814 /* Create an error chunk and fill it in with our payload. */ 1815 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1816 1817 return 0; 1818 } 1819 1820 1821 /* Do not attempt to handle the HOST_NAME parm. However, do 1822 * send back an indicator to the peer. 1823 */ 1824 static int sctp_process_hn_param(const struct sctp_association *asoc, 1825 union sctp_params param, 1826 struct sctp_chunk *chunk, 1827 struct sctp_chunk **errp) 1828 { 1829 __u16 len = ntohs(param.p->length); 1830 1831 /* Processing of the HOST_NAME parameter will generate an 1832 * ABORT. If we've accumulated any non-fatal errors, they 1833 * would be unrecognized parameters and we should not include 1834 * them in the ABORT. 1835 */ 1836 if (*errp) 1837 sctp_chunk_free(*errp); 1838 1839 *errp = sctp_make_op_error_space(asoc, chunk, len); 1840 1841 if (*errp) { 1842 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len); 1843 sctp_addto_chunk(*errp, len, param.v); 1844 } 1845 1846 /* Stop processing this chunk. */ 1847 return 0; 1848 } 1849 1850 static int sctp_verify_ext_param(union sctp_params param) 1851 { 1852 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 1853 int have_auth = 0; 1854 int have_asconf = 0; 1855 int i; 1856 1857 for (i = 0; i < num_ext; i++) { 1858 switch (param.ext->chunks[i]) { 1859 case SCTP_CID_AUTH: 1860 have_auth = 1; 1861 break; 1862 case SCTP_CID_ASCONF: 1863 case SCTP_CID_ASCONF_ACK: 1864 have_asconf = 1; 1865 break; 1866 } 1867 } 1868 1869 /* ADD-IP Security: The draft requires us to ABORT or ignore the 1870 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 1871 * only if ADD-IP is turned on and we are not backward-compatible 1872 * mode. 1873 */ 1874 if (sctp_addip_noauth) 1875 return 1; 1876 1877 if (sctp_addip_enable && !have_auth && have_asconf) 1878 return 0; 1879 1880 return 1; 1881 } 1882 1883 static void sctp_process_ext_param(struct sctp_association *asoc, 1884 union sctp_params param) 1885 { 1886 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 1887 int i; 1888 1889 for (i = 0; i < num_ext; i++) { 1890 switch (param.ext->chunks[i]) { 1891 case SCTP_CID_FWD_TSN: 1892 if (sctp_prsctp_enable && 1893 !asoc->peer.prsctp_capable) 1894 asoc->peer.prsctp_capable = 1; 1895 break; 1896 case SCTP_CID_AUTH: 1897 /* if the peer reports AUTH, assume that he 1898 * supports AUTH. 1899 */ 1900 if (sctp_auth_enable) 1901 asoc->peer.auth_capable = 1; 1902 break; 1903 case SCTP_CID_ASCONF: 1904 case SCTP_CID_ASCONF_ACK: 1905 if (sctp_addip_enable) 1906 asoc->peer.asconf_capable = 1; 1907 break; 1908 default: 1909 break; 1910 } 1911 } 1912 } 1913 1914 /* RFC 3.2.1 & the Implementers Guide 2.2. 1915 * 1916 * The Parameter Types are encoded such that the 1917 * highest-order two bits specify the action that must be 1918 * taken if the processing endpoint does not recognize the 1919 * Parameter Type. 1920 * 1921 * 00 - Stop processing this parameter; do not process any further 1922 * parameters within this chunk 1923 * 1924 * 01 - Stop processing this parameter, do not process any further 1925 * parameters within this chunk, and report the unrecognized 1926 * parameter in an 'Unrecognized Parameter' ERROR chunk. 1927 * 1928 * 10 - Skip this parameter and continue processing. 1929 * 1930 * 11 - Skip this parameter and continue processing but 1931 * report the unrecognized parameter in an 1932 * 'Unrecognized Parameter' ERROR chunk. 1933 * 1934 * Return value: 1935 * SCTP_IERROR_NO_ERROR - continue with the chunk 1936 * SCTP_IERROR_ERROR - stop and report an error. 1937 * SCTP_IERROR_NOMEME - out of memory. 1938 */ 1939 static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc, 1940 union sctp_params param, 1941 struct sctp_chunk *chunk, 1942 struct sctp_chunk **errp) 1943 { 1944 int retval = SCTP_IERROR_NO_ERROR; 1945 1946 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 1947 case SCTP_PARAM_ACTION_DISCARD: 1948 retval = SCTP_IERROR_ERROR; 1949 break; 1950 case SCTP_PARAM_ACTION_SKIP: 1951 break; 1952 case SCTP_PARAM_ACTION_DISCARD_ERR: 1953 retval = SCTP_IERROR_ERROR; 1954 /* Fall through */ 1955 case SCTP_PARAM_ACTION_SKIP_ERR: 1956 /* Make an ERROR chunk, preparing enough room for 1957 * returning multiple unknown parameters. 1958 */ 1959 if (NULL == *errp) 1960 *errp = sctp_make_op_error_space(asoc, chunk, 1961 ntohs(chunk->chunk_hdr->length)); 1962 1963 if (*errp) { 1964 sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, 1965 WORD_ROUND(ntohs(param.p->length))); 1966 sctp_addto_chunk(*errp, 1967 WORD_ROUND(ntohs(param.p->length)), 1968 param.v); 1969 } else { 1970 /* If there is no memory for generating the ERROR 1971 * report as specified, an ABORT will be triggered 1972 * to the peer and the association won't be 1973 * established. 1974 */ 1975 retval = SCTP_IERROR_NOMEM; 1976 } 1977 break; 1978 default: 1979 break; 1980 } 1981 1982 return retval; 1983 } 1984 1985 /* Verify variable length parameters 1986 * Return values: 1987 * SCTP_IERROR_ABORT - trigger an ABORT 1988 * SCTP_IERROR_NOMEM - out of memory (abort) 1989 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 1990 * SCTP_IERROR_NO_ERROR - continue with the chunk 1991 */ 1992 static sctp_ierror_t sctp_verify_param(const struct sctp_association *asoc, 1993 union sctp_params param, 1994 sctp_cid_t cid, 1995 struct sctp_chunk *chunk, 1996 struct sctp_chunk **err_chunk) 1997 { 1998 struct sctp_hmac_algo_param *hmacs; 1999 int retval = SCTP_IERROR_NO_ERROR; 2000 __u16 n_elt, id = 0; 2001 int i; 2002 2003 /* FIXME - This routine is not looking at each parameter per the 2004 * chunk type, i.e., unrecognized parameters should be further 2005 * identified based on the chunk id. 2006 */ 2007 2008 switch (param.p->type) { 2009 case SCTP_PARAM_IPV4_ADDRESS: 2010 case SCTP_PARAM_IPV6_ADDRESS: 2011 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2012 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2013 case SCTP_PARAM_STATE_COOKIE: 2014 case SCTP_PARAM_HEARTBEAT_INFO: 2015 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2016 case SCTP_PARAM_ECN_CAPABLE: 2017 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2018 break; 2019 2020 case SCTP_PARAM_SUPPORTED_EXT: 2021 if (!sctp_verify_ext_param(param)) 2022 return SCTP_IERROR_ABORT; 2023 break; 2024 2025 case SCTP_PARAM_SET_PRIMARY: 2026 if (sctp_addip_enable) 2027 break; 2028 goto fallthrough; 2029 2030 case SCTP_PARAM_HOST_NAME_ADDRESS: 2031 /* Tell the peer, we won't support this param. */ 2032 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2033 retval = SCTP_IERROR_ABORT; 2034 break; 2035 2036 case SCTP_PARAM_FWD_TSN_SUPPORT: 2037 if (sctp_prsctp_enable) 2038 break; 2039 goto fallthrough; 2040 2041 case SCTP_PARAM_RANDOM: 2042 if (!sctp_auth_enable) 2043 goto fallthrough; 2044 2045 /* SCTP-AUTH: Secion 6.1 2046 * If the random number is not 32 byte long the association 2047 * MUST be aborted. The ABORT chunk SHOULD contain the error 2048 * cause 'Protocol Violation'. 2049 */ 2050 if (SCTP_AUTH_RANDOM_LENGTH != 2051 ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) { 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_CHUNKS: 2059 if (!sctp_auth_enable) 2060 goto fallthrough; 2061 2062 /* SCTP-AUTH: Section 3.2 2063 * The CHUNKS parameter MUST be included once in the INIT or 2064 * INIT-ACK chunk if the sender wants to receive authenticated 2065 * chunks. Its maximum length is 260 bytes. 2066 */ 2067 if (260 < ntohs(param.p->length)) { 2068 sctp_process_inv_paramlength(asoc, param.p, 2069 chunk, err_chunk); 2070 retval = SCTP_IERROR_ABORT; 2071 } 2072 break; 2073 2074 case SCTP_PARAM_HMAC_ALGO: 2075 if (!sctp_auth_enable) 2076 goto fallthrough; 2077 2078 hmacs = (struct sctp_hmac_algo_param *)param.p; 2079 n_elt = (ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) >> 1; 2080 2081 /* SCTP-AUTH: Section 6.1 2082 * The HMAC algorithm based on SHA-1 MUST be supported and 2083 * included in the HMAC-ALGO parameter. 2084 */ 2085 for (i = 0; i < n_elt; i++) { 2086 id = ntohs(hmacs->hmac_ids[i]); 2087 2088 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2089 break; 2090 } 2091 2092 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2093 sctp_process_inv_paramlength(asoc, param.p, chunk, 2094 err_chunk); 2095 retval = SCTP_IERROR_ABORT; 2096 } 2097 break; 2098 fallthrough: 2099 default: 2100 SCTP_DEBUG_PRINTK("Unrecognized param: %d for chunk %d.\n", 2101 ntohs(param.p->type), cid); 2102 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2103 break; 2104 } 2105 return retval; 2106 } 2107 2108 /* Verify the INIT packet before we process it. */ 2109 int sctp_verify_init(const struct sctp_association *asoc, 2110 sctp_cid_t cid, 2111 sctp_init_chunk_t *peer_init, 2112 struct sctp_chunk *chunk, 2113 struct sctp_chunk **errp) 2114 { 2115 union sctp_params param; 2116 int has_cookie = 0; 2117 int result; 2118 2119 /* Verify stream values are non-zero. */ 2120 if ((0 == peer_init->init_hdr.num_outbound_streams) || 2121 (0 == peer_init->init_hdr.num_inbound_streams) || 2122 (0 == peer_init->init_hdr.init_tag) || 2123 (SCTP_DEFAULT_MINWINDOW > ntohl(peer_init->init_hdr.a_rwnd))) { 2124 2125 return sctp_process_inv_mandatory(asoc, chunk, errp); 2126 } 2127 2128 /* Check for missing mandatory parameters. */ 2129 sctp_walk_params(param, peer_init, init_hdr.params) { 2130 2131 if (SCTP_PARAM_STATE_COOKIE == param.p->type) 2132 has_cookie = 1; 2133 2134 } /* for (loop through all parameters) */ 2135 2136 /* There is a possibility that a parameter length was bad and 2137 * in that case we would have stoped walking the parameters. 2138 * The current param.p would point at the bad one. 2139 * Current consensus on the mailing list is to generate a PROTOCOL 2140 * VIOLATION error. We build the ERROR chunk here and let the normal 2141 * error handling code build and send the packet. 2142 */ 2143 if (param.v != (void*)chunk->chunk_end) 2144 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2145 2146 /* The only missing mandatory param possible today is 2147 * the state cookie for an INIT-ACK chunk. 2148 */ 2149 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2150 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2151 chunk, errp); 2152 2153 /* Verify all the variable length parameters */ 2154 sctp_walk_params(param, peer_init, init_hdr.params) { 2155 2156 result = sctp_verify_param(asoc, param, cid, chunk, errp); 2157 switch (result) { 2158 case SCTP_IERROR_ABORT: 2159 case SCTP_IERROR_NOMEM: 2160 return 0; 2161 case SCTP_IERROR_ERROR: 2162 return 1; 2163 case SCTP_IERROR_NO_ERROR: 2164 default: 2165 break; 2166 } 2167 2168 } /* for (loop through all parameters) */ 2169 2170 return 1; 2171 } 2172 2173 /* Unpack the parameters in an INIT packet into an association. 2174 * Returns 0 on failure, else success. 2175 * FIXME: This is an association method. 2176 */ 2177 int sctp_process_init(struct sctp_association *asoc, sctp_cid_t cid, 2178 const union sctp_addr *peer_addr, 2179 sctp_init_chunk_t *peer_init, gfp_t gfp) 2180 { 2181 union sctp_params param; 2182 struct sctp_transport *transport; 2183 struct list_head *pos, *temp; 2184 char *cookie; 2185 2186 /* We must include the address that the INIT packet came from. 2187 * This is the only address that matters for an INIT packet. 2188 * When processing a COOKIE ECHO, we retrieve the from address 2189 * of the INIT from the cookie. 2190 */ 2191 2192 /* This implementation defaults to making the first transport 2193 * added as the primary transport. The source address seems to 2194 * be a a better choice than any of the embedded addresses. 2195 */ 2196 if (peer_addr) { 2197 if(!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2198 goto nomem; 2199 } 2200 2201 /* Process the initialization parameters. */ 2202 sctp_walk_params(param, peer_init, init_hdr.params) { 2203 2204 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2205 goto clean_up; 2206 } 2207 2208 /* AUTH: After processing the parameters, make sure that we 2209 * have all the required info to potentially do authentications. 2210 */ 2211 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2212 !asoc->peer.peer_hmacs)) 2213 asoc->peer.auth_capable = 0; 2214 2215 /* In a non-backward compatible mode, if the peer claims 2216 * support for ADD-IP but not AUTH, the ADD-IP spec states 2217 * that we MUST ABORT the association. Section 6. The section 2218 * also give us an option to silently ignore the packet, which 2219 * is what we'll do here. 2220 */ 2221 if (!sctp_addip_noauth && 2222 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2223 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2224 SCTP_PARAM_DEL_IP | 2225 SCTP_PARAM_SET_PRIMARY); 2226 asoc->peer.asconf_capable = 0; 2227 goto clean_up; 2228 } 2229 2230 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2231 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2232 transport = list_entry(pos, struct sctp_transport, transports); 2233 if (transport->state == SCTP_UNKNOWN) { 2234 sctp_assoc_rm_peer(asoc, transport); 2235 } 2236 } 2237 2238 /* The fixed INIT headers are always in network byte 2239 * order. 2240 */ 2241 asoc->peer.i.init_tag = 2242 ntohl(peer_init->init_hdr.init_tag); 2243 asoc->peer.i.a_rwnd = 2244 ntohl(peer_init->init_hdr.a_rwnd); 2245 asoc->peer.i.num_outbound_streams = 2246 ntohs(peer_init->init_hdr.num_outbound_streams); 2247 asoc->peer.i.num_inbound_streams = 2248 ntohs(peer_init->init_hdr.num_inbound_streams); 2249 asoc->peer.i.initial_tsn = 2250 ntohl(peer_init->init_hdr.initial_tsn); 2251 2252 /* Apply the upper bounds for output streams based on peer's 2253 * number of inbound streams. 2254 */ 2255 if (asoc->c.sinit_num_ostreams > 2256 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2257 asoc->c.sinit_num_ostreams = 2258 ntohs(peer_init->init_hdr.num_inbound_streams); 2259 } 2260 2261 if (asoc->c.sinit_max_instreams > 2262 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2263 asoc->c.sinit_max_instreams = 2264 ntohs(peer_init->init_hdr.num_outbound_streams); 2265 } 2266 2267 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2268 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2269 2270 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2271 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2272 2273 /* Copy cookie in case we need to resend COOKIE-ECHO. */ 2274 cookie = asoc->peer.cookie; 2275 if (cookie) { 2276 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp); 2277 if (!asoc->peer.cookie) 2278 goto clean_up; 2279 } 2280 2281 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2282 * high (for example, implementations MAY use the size of the receiver 2283 * advertised window). 2284 */ 2285 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2286 transports) { 2287 transport->ssthresh = asoc->peer.i.a_rwnd; 2288 } 2289 2290 /* Set up the TSN tracking pieces. */ 2291 sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE, 2292 asoc->peer.i.initial_tsn); 2293 2294 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2295 * 2296 * The stream sequence number in all the streams shall start 2297 * from 0 when the association is established. Also, when the 2298 * stream sequence number reaches the value 65535 the next 2299 * stream sequence number shall be set to 0. 2300 */ 2301 2302 /* Allocate storage for the negotiated streams if it is not a temporary 2303 * association. 2304 */ 2305 if (!asoc->temp) { 2306 int error; 2307 2308 asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams, 2309 asoc->c.sinit_num_ostreams, gfp); 2310 if (!asoc->ssnmap) 2311 goto clean_up; 2312 2313 error = sctp_assoc_set_id(asoc, gfp); 2314 if (error) 2315 goto clean_up; 2316 } 2317 2318 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2319 * 2320 * When an endpoint has an ASCONF signaled change to be sent to the 2321 * remote endpoint it should do the following: 2322 * ... 2323 * A2) A serial number should be assigned to the Chunk. The serial 2324 * number should be a monotonically increasing number. All serial 2325 * numbers are defined to be initialized at the start of the 2326 * association to the same value as the Initial TSN. 2327 */ 2328 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2329 return 1; 2330 2331 clean_up: 2332 /* Release the transport structures. */ 2333 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2334 transport = list_entry(pos, struct sctp_transport, transports); 2335 if (transport->state != SCTP_ACTIVE) 2336 sctp_assoc_rm_peer(asoc, transport); 2337 } 2338 2339 nomem: 2340 return 0; 2341 } 2342 2343 2344 /* Update asoc with the option described in param. 2345 * 2346 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2347 * 2348 * asoc is the association to update. 2349 * param is the variable length parameter to use for update. 2350 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2351 * If the current packet is an INIT we want to minimize the amount of 2352 * work we do. In particular, we should not build transport 2353 * structures for the addresses. 2354 */ 2355 static int sctp_process_param(struct sctp_association *asoc, 2356 union sctp_params param, 2357 const union sctp_addr *peer_addr, 2358 gfp_t gfp) 2359 { 2360 union sctp_addr addr; 2361 int i; 2362 __u16 sat; 2363 int retval = 1; 2364 sctp_scope_t scope; 2365 time_t stale; 2366 struct sctp_af *af; 2367 union sctp_addr_param *addr_param; 2368 struct sctp_transport *t; 2369 2370 /* We maintain all INIT parameters in network byte order all the 2371 * time. This allows us to not worry about whether the parameters 2372 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2373 */ 2374 switch (param.p->type) { 2375 case SCTP_PARAM_IPV6_ADDRESS: 2376 if (PF_INET6 != asoc->base.sk->sk_family) 2377 break; 2378 goto do_addr_param; 2379 2380 case SCTP_PARAM_IPV4_ADDRESS: 2381 /* v4 addresses are not allowed on v6-only socket */ 2382 if (ipv6_only_sock(asoc->base.sk)) 2383 break; 2384 do_addr_param: 2385 af = sctp_get_af_specific(param_type2af(param.p->type)); 2386 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); 2387 scope = sctp_scope(peer_addr); 2388 if (sctp_in_scope(&addr, scope)) 2389 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2390 return 0; 2391 break; 2392 2393 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2394 if (!sctp_cookie_preserve_enable) 2395 break; 2396 2397 stale = ntohl(param.life->lifespan_increment); 2398 2399 /* Suggested Cookie Life span increment's unit is msec, 2400 * (1/1000sec). 2401 */ 2402 asoc->cookie_life.tv_sec += stale / 1000; 2403 asoc->cookie_life.tv_usec += (stale % 1000) * 1000; 2404 break; 2405 2406 case SCTP_PARAM_HOST_NAME_ADDRESS: 2407 SCTP_DEBUG_PRINTK("unimplemented SCTP_HOST_NAME_ADDRESS\n"); 2408 break; 2409 2410 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2411 /* Turn off the default values first so we'll know which 2412 * ones are really set by the peer. 2413 */ 2414 asoc->peer.ipv4_address = 0; 2415 asoc->peer.ipv6_address = 0; 2416 2417 /* Assume that peer supports the address family 2418 * by which it sends a packet. 2419 */ 2420 if (peer_addr->sa.sa_family == AF_INET6) 2421 asoc->peer.ipv6_address = 1; 2422 else if (peer_addr->sa.sa_family == AF_INET) 2423 asoc->peer.ipv4_address = 1; 2424 2425 /* Cycle through address types; avoid divide by 0. */ 2426 sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2427 if (sat) 2428 sat /= sizeof(__u16); 2429 2430 for (i = 0; i < sat; ++i) { 2431 switch (param.sat->types[i]) { 2432 case SCTP_PARAM_IPV4_ADDRESS: 2433 asoc->peer.ipv4_address = 1; 2434 break; 2435 2436 case SCTP_PARAM_IPV6_ADDRESS: 2437 if (PF_INET6 == asoc->base.sk->sk_family) 2438 asoc->peer.ipv6_address = 1; 2439 break; 2440 2441 case SCTP_PARAM_HOST_NAME_ADDRESS: 2442 asoc->peer.hostname_address = 1; 2443 break; 2444 2445 default: /* Just ignore anything else. */ 2446 break; 2447 } 2448 } 2449 break; 2450 2451 case SCTP_PARAM_STATE_COOKIE: 2452 asoc->peer.cookie_len = 2453 ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2454 asoc->peer.cookie = param.cookie->body; 2455 break; 2456 2457 case SCTP_PARAM_HEARTBEAT_INFO: 2458 /* Would be odd to receive, but it causes no problems. */ 2459 break; 2460 2461 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2462 /* Rejected during verify stage. */ 2463 break; 2464 2465 case SCTP_PARAM_ECN_CAPABLE: 2466 asoc->peer.ecn_capable = 1; 2467 break; 2468 2469 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2470 asoc->peer.adaptation_ind = param.aind->adaptation_ind; 2471 break; 2472 2473 case SCTP_PARAM_SET_PRIMARY: 2474 if (!sctp_addip_enable) 2475 goto fall_through; 2476 2477 addr_param = param.v + sizeof(sctp_addip_param_t); 2478 2479 af = sctp_get_af_specific(param_type2af(param.p->type)); 2480 af->from_addr_param(&addr, addr_param, 2481 htons(asoc->peer.port), 0); 2482 2483 /* if the address is invalid, we can't process it. 2484 * XXX: see spec for what to do. 2485 */ 2486 if (!af->addr_valid(&addr, NULL, NULL)) 2487 break; 2488 2489 t = sctp_assoc_lookup_paddr(asoc, &addr); 2490 if (!t) 2491 break; 2492 2493 sctp_assoc_set_primary(asoc, t); 2494 break; 2495 2496 case SCTP_PARAM_SUPPORTED_EXT: 2497 sctp_process_ext_param(asoc, param); 2498 break; 2499 2500 case SCTP_PARAM_FWD_TSN_SUPPORT: 2501 if (sctp_prsctp_enable) { 2502 asoc->peer.prsctp_capable = 1; 2503 break; 2504 } 2505 /* Fall Through */ 2506 goto fall_through; 2507 2508 case SCTP_PARAM_RANDOM: 2509 if (!sctp_auth_enable) 2510 goto fall_through; 2511 2512 /* Save peer's random parameter */ 2513 asoc->peer.peer_random = kmemdup(param.p, 2514 ntohs(param.p->length), gfp); 2515 if (!asoc->peer.peer_random) { 2516 retval = 0; 2517 break; 2518 } 2519 break; 2520 2521 case SCTP_PARAM_HMAC_ALGO: 2522 if (!sctp_auth_enable) 2523 goto fall_through; 2524 2525 /* Save peer's HMAC list */ 2526 asoc->peer.peer_hmacs = kmemdup(param.p, 2527 ntohs(param.p->length), gfp); 2528 if (!asoc->peer.peer_hmacs) { 2529 retval = 0; 2530 break; 2531 } 2532 2533 /* Set the default HMAC the peer requested*/ 2534 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2535 break; 2536 2537 case SCTP_PARAM_CHUNKS: 2538 if (!sctp_auth_enable) 2539 goto fall_through; 2540 2541 asoc->peer.peer_chunks = kmemdup(param.p, 2542 ntohs(param.p->length), gfp); 2543 if (!asoc->peer.peer_chunks) 2544 retval = 0; 2545 break; 2546 fall_through: 2547 default: 2548 /* Any unrecognized parameters should have been caught 2549 * and handled by sctp_verify_param() which should be 2550 * called prior to this routine. Simply log the error 2551 * here. 2552 */ 2553 SCTP_DEBUG_PRINTK("Ignoring param: %d for association %p.\n", 2554 ntohs(param.p->type), asoc); 2555 break; 2556 } 2557 2558 return retval; 2559 } 2560 2561 /* Select a new verification tag. */ 2562 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2563 { 2564 /* I believe that this random number generator complies with RFC1750. 2565 * A tag of 0 is reserved for special cases (e.g. INIT). 2566 */ 2567 __u32 x; 2568 2569 do { 2570 get_random_bytes(&x, sizeof(__u32)); 2571 } while (x == 0); 2572 2573 return x; 2574 } 2575 2576 /* Select an initial TSN to send during startup. */ 2577 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2578 { 2579 __u32 retval; 2580 2581 get_random_bytes(&retval, sizeof(__u32)); 2582 return retval; 2583 } 2584 2585 /* 2586 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2587 * 0 1 2 3 2588 * 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 2589 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2590 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2591 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2592 * | Serial Number | 2593 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2594 * | Address Parameter | 2595 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2596 * | ASCONF Parameter #1 | 2597 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2598 * \ \ 2599 * / .... / 2600 * \ \ 2601 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2602 * | ASCONF Parameter #N | 2603 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2604 * 2605 * Address Parameter and other parameter will not be wrapped in this function 2606 */ 2607 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2608 union sctp_addr *addr, 2609 int vparam_len) 2610 { 2611 sctp_addiphdr_t asconf; 2612 struct sctp_chunk *retval; 2613 int length = sizeof(asconf) + vparam_len; 2614 union sctp_addr_param addrparam; 2615 int addrlen; 2616 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2617 2618 addrlen = af->to_addr_param(addr, &addrparam); 2619 if (!addrlen) 2620 return NULL; 2621 length += addrlen; 2622 2623 /* Create the chunk. */ 2624 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF, 0, length); 2625 if (!retval) 2626 return NULL; 2627 2628 asconf.serial = htonl(asoc->addip_serial++); 2629 2630 retval->subh.addip_hdr = 2631 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2632 retval->param_hdr.v = 2633 sctp_addto_chunk(retval, addrlen, &addrparam); 2634 2635 return retval; 2636 } 2637 2638 /* ADDIP 2639 * 3.2.1 Add IP Address 2640 * 0 1 2 3 2641 * 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 2642 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2643 * | Type = 0xC001 | Length = Variable | 2644 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2645 * | ASCONF-Request Correlation ID | 2646 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2647 * | Address Parameter | 2648 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2649 * 2650 * 3.2.2 Delete IP Address 2651 * 0 1 2 3 2652 * 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 2653 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2654 * | Type = 0xC002 | Length = Variable | 2655 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2656 * | ASCONF-Request Correlation ID | 2657 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2658 * | Address Parameter | 2659 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2660 * 2661 */ 2662 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2663 union sctp_addr *laddr, 2664 struct sockaddr *addrs, 2665 int addrcnt, 2666 __be16 flags) 2667 { 2668 sctp_addip_param_t param; 2669 struct sctp_chunk *retval; 2670 union sctp_addr_param addr_param; 2671 union sctp_addr *addr; 2672 void *addr_buf; 2673 struct sctp_af *af; 2674 int paramlen = sizeof(param); 2675 int addr_param_len = 0; 2676 int totallen = 0; 2677 int i; 2678 2679 /* Get total length of all the address parameters. */ 2680 addr_buf = addrs; 2681 for (i = 0; i < addrcnt; i++) { 2682 addr = (union sctp_addr *)addr_buf; 2683 af = sctp_get_af_specific(addr->v4.sin_family); 2684 addr_param_len = af->to_addr_param(addr, &addr_param); 2685 2686 totallen += paramlen; 2687 totallen += addr_param_len; 2688 2689 addr_buf += af->sockaddr_len; 2690 } 2691 2692 /* Create an asconf chunk with the required length. */ 2693 retval = sctp_make_asconf(asoc, laddr, totallen); 2694 if (!retval) 2695 return NULL; 2696 2697 /* Add the address parameters to the asconf chunk. */ 2698 addr_buf = addrs; 2699 for (i = 0; i < addrcnt; i++) { 2700 addr = (union sctp_addr *)addr_buf; 2701 af = sctp_get_af_specific(addr->v4.sin_family); 2702 addr_param_len = af->to_addr_param(addr, &addr_param); 2703 param.param_hdr.type = flags; 2704 param.param_hdr.length = htons(paramlen + addr_param_len); 2705 param.crr_id = i; 2706 2707 sctp_addto_chunk(retval, paramlen, ¶m); 2708 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2709 2710 addr_buf += af->sockaddr_len; 2711 } 2712 return retval; 2713 } 2714 2715 /* ADDIP 2716 * 3.2.4 Set Primary IP Address 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 =0xC004 | Length = Variable | 2721 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2722 * | ASCONF-Request Correlation ID | 2723 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2724 * | Address Parameter | 2725 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2726 * 2727 * Create an ASCONF chunk with Set Primary IP address parameter. 2728 */ 2729 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2730 union sctp_addr *addr) 2731 { 2732 sctp_addip_param_t param; 2733 struct sctp_chunk *retval; 2734 int len = sizeof(param); 2735 union sctp_addr_param addrparam; 2736 int addrlen; 2737 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2738 2739 addrlen = af->to_addr_param(addr, &addrparam); 2740 if (!addrlen) 2741 return NULL; 2742 len += addrlen; 2743 2744 /* Create the chunk and make asconf header. */ 2745 retval = sctp_make_asconf(asoc, addr, len); 2746 if (!retval) 2747 return NULL; 2748 2749 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2750 param.param_hdr.length = htons(len); 2751 param.crr_id = 0; 2752 2753 sctp_addto_chunk(retval, sizeof(param), ¶m); 2754 sctp_addto_chunk(retval, addrlen, &addrparam); 2755 2756 return retval; 2757 } 2758 2759 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2760 * 0 1 2 3 2761 * 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 2762 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2763 * | Type = 0x80 | Chunk Flags | Chunk Length | 2764 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2765 * | Serial Number | 2766 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2767 * | ASCONF Parameter Response#1 | 2768 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2769 * \ \ 2770 * / .... / 2771 * \ \ 2772 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2773 * | ASCONF Parameter Response#N | 2774 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2775 * 2776 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2777 */ 2778 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2779 __u32 serial, int vparam_len) 2780 { 2781 sctp_addiphdr_t asconf; 2782 struct sctp_chunk *retval; 2783 int length = sizeof(asconf) + vparam_len; 2784 2785 /* Create the chunk. */ 2786 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF_ACK, 0, length); 2787 if (!retval) 2788 return NULL; 2789 2790 asconf.serial = htonl(serial); 2791 2792 retval->subh.addip_hdr = 2793 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2794 2795 return retval; 2796 } 2797 2798 /* Add response parameters to an ASCONF_ACK chunk. */ 2799 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2800 __be16 err_code, sctp_addip_param_t *asconf_param) 2801 { 2802 sctp_addip_param_t ack_param; 2803 sctp_errhdr_t err_param; 2804 int asconf_param_len = 0; 2805 int err_param_len = 0; 2806 __be16 response_type; 2807 2808 if (SCTP_ERROR_NO_ERROR == err_code) { 2809 response_type = SCTP_PARAM_SUCCESS_REPORT; 2810 } else { 2811 response_type = SCTP_PARAM_ERR_CAUSE; 2812 err_param_len = sizeof(err_param); 2813 if (asconf_param) 2814 asconf_param_len = 2815 ntohs(asconf_param->param_hdr.length); 2816 } 2817 2818 /* Add Success Indication or Error Cause Indication parameter. */ 2819 ack_param.param_hdr.type = response_type; 2820 ack_param.param_hdr.length = htons(sizeof(ack_param) + 2821 err_param_len + 2822 asconf_param_len); 2823 ack_param.crr_id = crr_id; 2824 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 2825 2826 if (SCTP_ERROR_NO_ERROR == err_code) 2827 return; 2828 2829 /* Add Error Cause parameter. */ 2830 err_param.cause = err_code; 2831 err_param.length = htons(err_param_len + asconf_param_len); 2832 sctp_addto_chunk(chunk, err_param_len, &err_param); 2833 2834 /* Add the failed TLV copied from ASCONF chunk. */ 2835 if (asconf_param) 2836 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 2837 } 2838 2839 /* Process a asconf parameter. */ 2840 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 2841 struct sctp_chunk *asconf, 2842 sctp_addip_param_t *asconf_param) 2843 { 2844 struct sctp_transport *peer; 2845 struct sctp_af *af; 2846 union sctp_addr addr; 2847 union sctp_addr_param *addr_param; 2848 2849 addr_param = (union sctp_addr_param *) 2850 ((void *)asconf_param + sizeof(sctp_addip_param_t)); 2851 2852 switch (addr_param->v4.param_hdr.type) { 2853 case SCTP_PARAM_IPV6_ADDRESS: 2854 if (!asoc->peer.ipv6_address) 2855 return SCTP_ERROR_INV_PARAM; 2856 break; 2857 case SCTP_PARAM_IPV4_ADDRESS: 2858 if (!asoc->peer.ipv4_address) 2859 return SCTP_ERROR_INV_PARAM; 2860 break; 2861 default: 2862 return SCTP_ERROR_INV_PARAM; 2863 } 2864 2865 af = sctp_get_af_specific(param_type2af(addr_param->v4.param_hdr.type)); 2866 if (unlikely(!af)) 2867 return SCTP_ERROR_INV_PARAM; 2868 2869 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); 2870 2871 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 2872 * or multicast address. 2873 * (note: wildcard is permitted and requires special handling so 2874 * make sure we check for that) 2875 */ 2876 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 2877 return SCTP_ERROR_INV_PARAM; 2878 2879 switch (asconf_param->param_hdr.type) { 2880 case SCTP_PARAM_ADD_IP: 2881 /* Section 4.2.1: 2882 * If the address 0.0.0.0 or ::0 is provided, the source 2883 * address of the packet MUST be added. 2884 */ 2885 if (af->is_any(&addr)) 2886 memcpy(&addr, &asconf->source, sizeof(addr)); 2887 2888 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 2889 * request and does not have the local resources to add this 2890 * new address to the association, it MUST return an Error 2891 * Cause TLV set to the new error code 'Operation Refused 2892 * Due to Resource Shortage'. 2893 */ 2894 2895 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 2896 if (!peer) 2897 return SCTP_ERROR_RSRC_LOW; 2898 2899 /* Start the heartbeat timer. */ 2900 if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer))) 2901 sctp_transport_hold(peer); 2902 break; 2903 case SCTP_PARAM_DEL_IP: 2904 /* ADDIP 4.3 D7) If a request is received to delete the 2905 * last remaining IP address of a peer endpoint, the receiver 2906 * MUST send an Error Cause TLV with the error cause set to the 2907 * new error code 'Request to Delete Last Remaining IP Address'. 2908 */ 2909 if (asoc->peer.transport_count == 1) 2910 return SCTP_ERROR_DEL_LAST_IP; 2911 2912 /* ADDIP 4.3 D8) If a request is received to delete an IP 2913 * address which is also the source address of the IP packet 2914 * which contained the ASCONF chunk, the receiver MUST reject 2915 * this request. To reject the request the receiver MUST send 2916 * an Error Cause TLV set to the new error code 'Request to 2917 * Delete Source IP Address' 2918 */ 2919 if (sctp_cmp_addr_exact(sctp_source(asconf), &addr)) 2920 return SCTP_ERROR_DEL_SRC_IP; 2921 2922 /* Section 4.2.2 2923 * If the address 0.0.0.0 or ::0 is provided, all 2924 * addresses of the peer except the source address of the 2925 * packet MUST be deleted. 2926 */ 2927 if (af->is_any(&addr)) { 2928 sctp_assoc_set_primary(asoc, asconf->transport); 2929 sctp_assoc_del_nonprimary_peers(asoc, 2930 asconf->transport); 2931 } else 2932 sctp_assoc_del_peer(asoc, &addr); 2933 break; 2934 case SCTP_PARAM_SET_PRIMARY: 2935 /* ADDIP Section 4.2.4 2936 * If the address 0.0.0.0 or ::0 is provided, the receiver 2937 * MAY mark the source address of the packet as its 2938 * primary. 2939 */ 2940 if (af->is_any(&addr)) 2941 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr)); 2942 2943 peer = sctp_assoc_lookup_paddr(asoc, &addr); 2944 if (!peer) 2945 return SCTP_ERROR_INV_PARAM; 2946 2947 sctp_assoc_set_primary(asoc, peer); 2948 break; 2949 default: 2950 return SCTP_ERROR_INV_PARAM; 2951 break; 2952 } 2953 2954 return SCTP_ERROR_NO_ERROR; 2955 } 2956 2957 /* Verify the ASCONF packet before we process it. */ 2958 int sctp_verify_asconf(const struct sctp_association *asoc, 2959 struct sctp_paramhdr *param_hdr, void *chunk_end, 2960 struct sctp_paramhdr **errp) { 2961 sctp_addip_param_t *asconf_param; 2962 union sctp_params param; 2963 int length, plen; 2964 2965 param.v = (sctp_paramhdr_t *) param_hdr; 2966 while (param.v <= chunk_end - sizeof(sctp_paramhdr_t)) { 2967 length = ntohs(param.p->length); 2968 *errp = param.p; 2969 2970 if (param.v > chunk_end - length || 2971 length < sizeof(sctp_paramhdr_t)) 2972 return 0; 2973 2974 switch (param.p->type) { 2975 case SCTP_PARAM_ADD_IP: 2976 case SCTP_PARAM_DEL_IP: 2977 case SCTP_PARAM_SET_PRIMARY: 2978 asconf_param = (sctp_addip_param_t *)param.v; 2979 plen = ntohs(asconf_param->param_hdr.length); 2980 if (plen < sizeof(sctp_addip_param_t) + 2981 sizeof(sctp_paramhdr_t)) 2982 return 0; 2983 break; 2984 case SCTP_PARAM_SUCCESS_REPORT: 2985 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2986 if (length != sizeof(sctp_addip_param_t)) 2987 return 0; 2988 2989 break; 2990 default: 2991 break; 2992 } 2993 2994 param.v += WORD_ROUND(length); 2995 } 2996 2997 if (param.v != chunk_end) 2998 return 0; 2999 3000 return 1; 3001 } 3002 3003 /* Process an incoming ASCONF chunk with the next expected serial no. and 3004 * return an ASCONF_ACK chunk to be sent in response. 3005 */ 3006 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3007 struct sctp_chunk *asconf) 3008 { 3009 sctp_addiphdr_t *hdr; 3010 union sctp_addr_param *addr_param; 3011 sctp_addip_param_t *asconf_param; 3012 struct sctp_chunk *asconf_ack; 3013 3014 __be16 err_code; 3015 int length = 0; 3016 int chunk_len; 3017 __u32 serial; 3018 int all_param_pass = 1; 3019 3020 chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t); 3021 hdr = (sctp_addiphdr_t *)asconf->skb->data; 3022 serial = ntohl(hdr->serial); 3023 3024 /* Skip the addiphdr and store a pointer to address parameter. */ 3025 length = sizeof(sctp_addiphdr_t); 3026 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3027 chunk_len -= length; 3028 3029 /* Skip the address parameter and store a pointer to the first 3030 * asconf parameter. 3031 */ 3032 length = ntohs(addr_param->v4.param_hdr.length); 3033 asconf_param = (sctp_addip_param_t *)((void *)addr_param + length); 3034 chunk_len -= length; 3035 3036 /* create an ASCONF_ACK chunk. 3037 * Based on the definitions of parameters, we know that the size of 3038 * ASCONF_ACK parameters are less than or equal to the twice of ASCONF 3039 * parameters. 3040 */ 3041 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 2); 3042 if (!asconf_ack) 3043 goto done; 3044 3045 /* Process the TLVs contained within the ASCONF chunk. */ 3046 while (chunk_len > 0) { 3047 err_code = sctp_process_asconf_param(asoc, asconf, 3048 asconf_param); 3049 /* ADDIP 4.1 A7) 3050 * If an error response is received for a TLV parameter, 3051 * all TLVs with no response before the failed TLV are 3052 * considered successful if not reported. All TLVs after 3053 * the failed response are considered unsuccessful unless 3054 * a specific success indication is present for the parameter. 3055 */ 3056 if (SCTP_ERROR_NO_ERROR != err_code) 3057 all_param_pass = 0; 3058 3059 if (!all_param_pass) 3060 sctp_add_asconf_response(asconf_ack, 3061 asconf_param->crr_id, err_code, 3062 asconf_param); 3063 3064 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3065 * an IP address sends an 'Out of Resource' in its response, it 3066 * MUST also fail any subsequent add or delete requests bundled 3067 * in the ASCONF. 3068 */ 3069 if (SCTP_ERROR_RSRC_LOW == err_code) 3070 goto done; 3071 3072 /* Move to the next ASCONF param. */ 3073 length = ntohs(asconf_param->param_hdr.length); 3074 asconf_param = (sctp_addip_param_t *)((void *)asconf_param + 3075 length); 3076 chunk_len -= length; 3077 } 3078 3079 done: 3080 asoc->peer.addip_serial++; 3081 3082 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3083 * after freeing the reference to old asconf ack if any. 3084 */ 3085 if (asconf_ack) { 3086 sctp_chunk_hold(asconf_ack); 3087 list_add_tail(&asconf_ack->transmitted_list, 3088 &asoc->asconf_ack_list); 3089 } 3090 3091 return asconf_ack; 3092 } 3093 3094 /* Process a asconf parameter that is successfully acked. */ 3095 static int sctp_asconf_param_success(struct sctp_association *asoc, 3096 sctp_addip_param_t *asconf_param) 3097 { 3098 struct sctp_af *af; 3099 union sctp_addr addr; 3100 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3101 union sctp_addr_param *addr_param; 3102 struct sctp_transport *transport; 3103 struct sctp_sockaddr_entry *saddr; 3104 int retval = 0; 3105 3106 addr_param = (union sctp_addr_param *) 3107 ((void *)asconf_param + sizeof(sctp_addip_param_t)); 3108 3109 /* We have checked the packet before, so we do not check again. */ 3110 af = sctp_get_af_specific(param_type2af(addr_param->v4.param_hdr.type)); 3111 af->from_addr_param(&addr, addr_param, htons(bp->port), 0); 3112 3113 switch (asconf_param->param_hdr.type) { 3114 case SCTP_PARAM_ADD_IP: 3115 /* This is always done in BH context with a socket lock 3116 * held, so the list can not change. 3117 */ 3118 local_bh_disable(); 3119 list_for_each_entry(saddr, &bp->address_list, list) { 3120 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3121 saddr->state = SCTP_ADDR_SRC; 3122 } 3123 local_bh_enable(); 3124 break; 3125 case SCTP_PARAM_DEL_IP: 3126 local_bh_disable(); 3127 retval = sctp_del_bind_addr(bp, &addr); 3128 local_bh_enable(); 3129 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3130 transports) { 3131 dst_release(transport->dst); 3132 sctp_transport_route(transport, NULL, 3133 sctp_sk(asoc->base.sk)); 3134 } 3135 break; 3136 default: 3137 break; 3138 } 3139 3140 return retval; 3141 } 3142 3143 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3144 * for the given asconf parameter. If there is no response for this parameter, 3145 * return the error code based on the third argument 'no_err'. 3146 * ADDIP 4.1 3147 * A7) If an error response is received for a TLV parameter, all TLVs with no 3148 * response before the failed TLV are considered successful if not reported. 3149 * All TLVs after the failed response are considered unsuccessful unless a 3150 * specific success indication is present for the parameter. 3151 */ 3152 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3153 sctp_addip_param_t *asconf_param, 3154 int no_err) 3155 { 3156 sctp_addip_param_t *asconf_ack_param; 3157 sctp_errhdr_t *err_param; 3158 int length; 3159 int asconf_ack_len; 3160 __be16 err_code; 3161 3162 if (no_err) 3163 err_code = SCTP_ERROR_NO_ERROR; 3164 else 3165 err_code = SCTP_ERROR_REQ_REFUSED; 3166 3167 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3168 sizeof(sctp_chunkhdr_t); 3169 3170 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3171 * the first asconf_ack parameter. 3172 */ 3173 length = sizeof(sctp_addiphdr_t); 3174 asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data + 3175 length); 3176 asconf_ack_len -= length; 3177 3178 while (asconf_ack_len > 0) { 3179 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3180 switch(asconf_ack_param->param_hdr.type) { 3181 case SCTP_PARAM_SUCCESS_REPORT: 3182 return SCTP_ERROR_NO_ERROR; 3183 case SCTP_PARAM_ERR_CAUSE: 3184 length = sizeof(sctp_addip_param_t); 3185 err_param = (sctp_errhdr_t *) 3186 ((void *)asconf_ack_param + length); 3187 asconf_ack_len -= length; 3188 if (asconf_ack_len > 0) 3189 return err_param->cause; 3190 else 3191 return SCTP_ERROR_INV_PARAM; 3192 break; 3193 default: 3194 return SCTP_ERROR_INV_PARAM; 3195 } 3196 } 3197 3198 length = ntohs(asconf_ack_param->param_hdr.length); 3199 asconf_ack_param = (sctp_addip_param_t *) 3200 ((void *)asconf_ack_param + length); 3201 asconf_ack_len -= length; 3202 } 3203 3204 return err_code; 3205 } 3206 3207 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3208 int sctp_process_asconf_ack(struct sctp_association *asoc, 3209 struct sctp_chunk *asconf_ack) 3210 { 3211 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3212 union sctp_addr_param *addr_param; 3213 sctp_addip_param_t *asconf_param; 3214 int length = 0; 3215 int asconf_len = asconf->skb->len; 3216 int all_param_pass = 0; 3217 int no_err = 1; 3218 int retval = 0; 3219 __be16 err_code = SCTP_ERROR_NO_ERROR; 3220 3221 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3222 * a pointer to address parameter. 3223 */ 3224 length = sizeof(sctp_addip_chunk_t); 3225 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3226 asconf_len -= length; 3227 3228 /* Skip the address parameter in the last asconf sent and store a 3229 * pointer to the first asconf parameter. 3230 */ 3231 length = ntohs(addr_param->v4.param_hdr.length); 3232 asconf_param = (sctp_addip_param_t *)((void *)addr_param + length); 3233 asconf_len -= length; 3234 3235 /* ADDIP 4.1 3236 * A8) If there is no response(s) to specific TLV parameter(s), and no 3237 * failures are indicated, then all request(s) are considered 3238 * successful. 3239 */ 3240 if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t)) 3241 all_param_pass = 1; 3242 3243 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3244 while (asconf_len > 0) { 3245 if (all_param_pass) 3246 err_code = SCTP_ERROR_NO_ERROR; 3247 else { 3248 err_code = sctp_get_asconf_response(asconf_ack, 3249 asconf_param, 3250 no_err); 3251 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3252 no_err = 0; 3253 } 3254 3255 switch (err_code) { 3256 case SCTP_ERROR_NO_ERROR: 3257 retval = sctp_asconf_param_success(asoc, asconf_param); 3258 break; 3259 3260 case SCTP_ERROR_RSRC_LOW: 3261 retval = 1; 3262 break; 3263 3264 case SCTP_ERROR_INV_PARAM: 3265 /* Disable sending this type of asconf parameter in 3266 * future. 3267 */ 3268 asoc->peer.addip_disabled_mask |= 3269 asconf_param->param_hdr.type; 3270 break; 3271 3272 case SCTP_ERROR_REQ_REFUSED: 3273 case SCTP_ERROR_DEL_LAST_IP: 3274 case SCTP_ERROR_DEL_SRC_IP: 3275 default: 3276 break; 3277 } 3278 3279 /* Skip the processed asconf parameter and move to the next 3280 * one. 3281 */ 3282 length = ntohs(asconf_param->param_hdr.length); 3283 asconf_param = (sctp_addip_param_t *)((void *)asconf_param + 3284 length); 3285 asconf_len -= length; 3286 } 3287 3288 /* Free the cached last sent asconf chunk. */ 3289 list_del_init(&asconf->transmitted_list); 3290 sctp_chunk_free(asconf); 3291 asoc->addip_last_asconf = NULL; 3292 3293 /* Send the next asconf chunk from the addip chunk queue. */ 3294 if (!list_empty(&asoc->addip_chunk_list)) { 3295 struct list_head *entry = asoc->addip_chunk_list.next; 3296 asconf = list_entry(entry, struct sctp_chunk, list); 3297 3298 list_del_init(entry); 3299 3300 /* Hold the chunk until an ASCONF_ACK is received. */ 3301 sctp_chunk_hold(asconf); 3302 if (sctp_primitive_ASCONF(asoc, asconf)) 3303 sctp_chunk_free(asconf); 3304 else 3305 asoc->addip_last_asconf = asconf; 3306 } 3307 3308 return retval; 3309 } 3310 3311 /* Make a FWD TSN chunk. */ 3312 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3313 __u32 new_cum_tsn, size_t nstreams, 3314 struct sctp_fwdtsn_skip *skiplist) 3315 { 3316 struct sctp_chunk *retval = NULL; 3317 struct sctp_fwdtsn_chunk *ftsn_chunk; 3318 struct sctp_fwdtsn_hdr ftsn_hdr; 3319 struct sctp_fwdtsn_skip skip; 3320 size_t hint; 3321 int i; 3322 3323 hint = (nstreams + 1) * sizeof(__u32); 3324 3325 retval = sctp_make_chunk(asoc, SCTP_CID_FWD_TSN, 0, hint); 3326 3327 if (!retval) 3328 return NULL; 3329 3330 ftsn_chunk = (struct sctp_fwdtsn_chunk *)retval->subh.fwdtsn_hdr; 3331 3332 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3333 retval->subh.fwdtsn_hdr = 3334 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3335 3336 for (i = 0; i < nstreams; i++) { 3337 skip.stream = skiplist[i].stream; 3338 skip.ssn = skiplist[i].ssn; 3339 sctp_addto_chunk(retval, sizeof(skip), &skip); 3340 } 3341 3342 return retval; 3343 } 3344