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, see 27 * <http://www.gnu.org/licenses/>. 28 * 29 * Please send any bug reports or fixes you make to the 30 * email address(es): 31 * lksctp developers <linux-sctp@vger.kernel.org> 32 * 33 * Written or modified by: 34 * La Monte H.P. Yarroll <piggy@acm.org> 35 * Karl Knutson <karl@athena.chicago.il.us> 36 * C. Robin <chris@hundredacre.ac.uk> 37 * Jon Grimm <jgrimm@us.ibm.com> 38 * Xingang Guo <xingang.guo@intel.com> 39 * Dajiang Zhang <dajiang.zhang@nokia.com> 40 * Sridhar Samudrala <sri@us.ibm.com> 41 * Daisy Chang <daisyc@us.ibm.com> 42 * Ardelle Fan <ardelle.fan@intel.com> 43 * Kevin Gao <kevin.gao@intel.com> 44 */ 45 46 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 47 48 #include <crypto/hash.h> 49 #include <linux/types.h> 50 #include <linux/kernel.h> 51 #include <linux/ip.h> 52 #include <linux/ipv6.h> 53 #include <linux/net.h> 54 #include <linux/inet.h> 55 #include <linux/scatterlist.h> 56 #include <linux/slab.h> 57 #include <net/sock.h> 58 59 #include <linux/skbuff.h> 60 #include <linux/random.h> /* for get_random_bytes */ 61 #include <net/sctp/sctp.h> 62 #include <net/sctp/sm.h> 63 64 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 65 __u8 type, __u8 flags, int paylen, 66 gfp_t gfp); 67 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 68 __u8 flags, int paylen, gfp_t gfp); 69 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 70 __u8 type, __u8 flags, int paylen, 71 gfp_t gfp); 72 static struct sctp_cookie_param *sctp_pack_cookie( 73 const struct sctp_endpoint *ep, 74 const struct sctp_association *asoc, 75 const struct sctp_chunk *init_chunk, 76 int *cookie_len, 77 const __u8 *raw_addrs, int addrs_len); 78 static int sctp_process_param(struct sctp_association *asoc, 79 union sctp_params param, 80 const union sctp_addr *peer_addr, 81 gfp_t gfp); 82 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 83 const void *data); 84 static void *sctp_addto_chunk_fixed(struct sctp_chunk *, int len, 85 const void *data); 86 87 /* Control chunk destructor */ 88 static void sctp_control_release_owner(struct sk_buff *skb) 89 { 90 /*TODO: do memory release */ 91 } 92 93 static void sctp_control_set_owner_w(struct sctp_chunk *chunk) 94 { 95 struct sctp_association *asoc = chunk->asoc; 96 struct sk_buff *skb = chunk->skb; 97 98 /* TODO: properly account for control chunks. 99 * To do it right we'll need: 100 * 1) endpoint if association isn't known. 101 * 2) proper memory accounting. 102 * 103 * For now don't do anything for now. 104 */ 105 skb->sk = asoc ? asoc->base.sk : NULL; 106 skb->destructor = sctp_control_release_owner; 107 } 108 109 /* What was the inbound interface for this chunk? */ 110 int sctp_chunk_iif(const struct sctp_chunk *chunk) 111 { 112 struct sk_buff *skb = chunk->skb; 113 114 return SCTP_INPUT_CB(skb)->af->skb_iif(skb); 115 } 116 117 /* RFC 2960 3.3.2 Initiation (INIT) (1) 118 * 119 * Note 2: The ECN capable field is reserved for future use of 120 * Explicit Congestion Notification. 121 */ 122 static const struct sctp_paramhdr ecap_param = { 123 SCTP_PARAM_ECN_CAPABLE, 124 cpu_to_be16(sizeof(struct sctp_paramhdr)), 125 }; 126 static const struct sctp_paramhdr prsctp_param = { 127 SCTP_PARAM_FWD_TSN_SUPPORT, 128 cpu_to_be16(sizeof(struct sctp_paramhdr)), 129 }; 130 131 /* A helper to initialize an op error inside a 132 * provided chunk, as most cause codes will be embedded inside an 133 * abort chunk. 134 */ 135 void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, 136 size_t paylen) 137 { 138 struct sctp_errhdr err; 139 __u16 len; 140 141 /* Cause code constants are now defined in network order. */ 142 err.cause = cause_code; 143 len = sizeof(err) + paylen; 144 err.length = htons(len); 145 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(err), &err); 146 } 147 148 /* A helper to initialize an op error inside a 149 * provided chunk, as most cause codes will be embedded inside an 150 * abort chunk. Differs from sctp_init_cause in that it won't oops 151 * if there isn't enough space in the op error chunk 152 */ 153 static int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code, 154 size_t paylen) 155 { 156 struct sctp_errhdr err; 157 __u16 len; 158 159 /* Cause code constants are now defined in network order. */ 160 err.cause = cause_code; 161 len = sizeof(err) + paylen; 162 err.length = htons(len); 163 164 if (skb_tailroom(chunk->skb) < len) 165 return -ENOSPC; 166 167 chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk, sizeof(err), &err); 168 169 return 0; 170 } 171 /* 3.3.2 Initiation (INIT) (1) 172 * 173 * This chunk is used to initiate a SCTP association between two 174 * endpoints. The format of the INIT chunk is shown below: 175 * 176 * 0 1 2 3 177 * 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 1 178 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 179 * | Type = 1 | Chunk Flags | Chunk Length | 180 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 181 * | Initiate Tag | 182 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 183 * | Advertised Receiver Window Credit (a_rwnd) | 184 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 185 * | Number of Outbound Streams | Number of Inbound Streams | 186 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 187 * | Initial TSN | 188 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 189 * \ \ 190 * / Optional/Variable-Length Parameters / 191 * \ \ 192 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 193 * 194 * 195 * The INIT chunk contains the following parameters. Unless otherwise 196 * noted, each parameter MUST only be included once in the INIT chunk. 197 * 198 * Fixed Parameters Status 199 * ---------------------------------------------- 200 * Initiate Tag Mandatory 201 * Advertised Receiver Window Credit Mandatory 202 * Number of Outbound Streams Mandatory 203 * Number of Inbound Streams Mandatory 204 * Initial TSN Mandatory 205 * 206 * Variable Parameters Status Type Value 207 * ------------------------------------------------------------- 208 * IPv4 Address (Note 1) Optional 5 209 * IPv6 Address (Note 1) Optional 6 210 * Cookie Preservative Optional 9 211 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000) 212 * Host Name Address (Note 3) Optional 11 213 * Supported Address Types (Note 4) Optional 12 214 */ 215 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc, 216 const struct sctp_bind_addr *bp, 217 gfp_t gfp, int vparam_len) 218 { 219 struct net *net = sock_net(asoc->base.sk); 220 struct sctp_supported_ext_param ext_param; 221 struct sctp_adaptation_ind_param aiparam; 222 struct sctp_paramhdr *auth_chunks = NULL; 223 struct sctp_paramhdr *auth_hmacs = NULL; 224 struct sctp_supported_addrs_param sat; 225 struct sctp_endpoint *ep = asoc->ep; 226 struct sctp_chunk *retval = NULL; 227 int num_types, addrs_len = 0; 228 struct sctp_inithdr init; 229 union sctp_params addrs; 230 struct sctp_sock *sp; 231 __u8 extensions[5]; 232 size_t chunksize; 233 __be16 types[2]; 234 int num_ext = 0; 235 236 /* RFC 2960 3.3.2 Initiation (INIT) (1) 237 * 238 * Note 1: The INIT chunks can contain multiple addresses that 239 * can be IPv4 and/or IPv6 in any combination. 240 */ 241 242 /* Convert the provided bind address list to raw format. */ 243 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp); 244 245 init.init_tag = htonl(asoc->c.my_vtag); 246 init.a_rwnd = htonl(asoc->rwnd); 247 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 248 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 249 init.initial_tsn = htonl(asoc->c.initial_tsn); 250 251 /* How many address types are needed? */ 252 sp = sctp_sk(asoc->base.sk); 253 num_types = sp->pf->supported_addrs(sp, types); 254 255 chunksize = sizeof(init) + addrs_len; 256 chunksize += SCTP_PAD4(SCTP_SAT_LEN(num_types)); 257 chunksize += sizeof(ecap_param); 258 259 if (asoc->prsctp_enable) 260 chunksize += sizeof(prsctp_param); 261 262 /* ADDIP: Section 4.2.7: 263 * An implementation supporting this extension [ADDIP] MUST list 264 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and 265 * INIT-ACK parameters. 266 */ 267 if (net->sctp.addip_enable) { 268 extensions[num_ext] = SCTP_CID_ASCONF; 269 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 270 num_ext += 2; 271 } 272 273 if (asoc->reconf_enable) { 274 extensions[num_ext] = SCTP_CID_RECONF; 275 num_ext += 1; 276 } 277 278 if (sp->adaptation_ind) 279 chunksize += sizeof(aiparam); 280 281 if (sp->strm_interleave) { 282 extensions[num_ext] = SCTP_CID_I_DATA; 283 num_ext += 1; 284 } 285 286 chunksize += vparam_len; 287 288 /* Account for AUTH related parameters */ 289 if (ep->auth_enable) { 290 /* Add random parameter length*/ 291 chunksize += sizeof(asoc->c.auth_random); 292 293 /* Add HMACS parameter length if any were defined */ 294 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; 295 if (auth_hmacs->length) 296 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 297 else 298 auth_hmacs = NULL; 299 300 /* Add CHUNKS parameter length */ 301 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; 302 if (auth_chunks->length) 303 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 304 else 305 auth_chunks = NULL; 306 307 extensions[num_ext] = SCTP_CID_AUTH; 308 num_ext += 1; 309 } 310 311 /* If we have any extensions to report, account for that */ 312 if (num_ext) 313 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext); 314 315 /* RFC 2960 3.3.2 Initiation (INIT) (1) 316 * 317 * Note 3: An INIT chunk MUST NOT contain more than one Host 318 * Name address parameter. Moreover, the sender of the INIT 319 * MUST NOT combine any other address types with the Host Name 320 * address in the INIT. The receiver of INIT MUST ignore any 321 * other address types if the Host Name address parameter is 322 * present in the received INIT chunk. 323 * 324 * PLEASE DO NOT FIXME [This version does not support Host Name.] 325 */ 326 327 retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp); 328 if (!retval) 329 goto nodata; 330 331 retval->subh.init_hdr = 332 sctp_addto_chunk(retval, sizeof(init), &init); 333 retval->param_hdr.v = 334 sctp_addto_chunk(retval, addrs_len, addrs.v); 335 336 /* RFC 2960 3.3.2 Initiation (INIT) (1) 337 * 338 * Note 4: This parameter, when present, specifies all the 339 * address types the sending endpoint can support. The absence 340 * of this parameter indicates that the sending endpoint can 341 * support any address type. 342 */ 343 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES; 344 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types)); 345 sctp_addto_chunk(retval, sizeof(sat), &sat); 346 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types); 347 348 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 349 350 /* Add the supported extensions parameter. Be nice and add this 351 * fist before addiding the parameters for the extensions themselves 352 */ 353 if (num_ext) { 354 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 355 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext); 356 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); 357 sctp_addto_param(retval, num_ext, extensions); 358 } 359 360 if (asoc->prsctp_enable) 361 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 362 363 if (sp->adaptation_ind) { 364 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 365 aiparam.param_hdr.length = htons(sizeof(aiparam)); 366 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 367 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 368 } 369 370 /* Add SCTP-AUTH chunks to the parameter list */ 371 if (ep->auth_enable) { 372 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random), 373 asoc->c.auth_random); 374 if (auth_hmacs) 375 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 376 auth_hmacs); 377 if (auth_chunks) 378 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 379 auth_chunks); 380 } 381 nodata: 382 kfree(addrs.v); 383 return retval; 384 } 385 386 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, 387 const struct sctp_chunk *chunk, 388 gfp_t gfp, int unkparam_len) 389 { 390 struct sctp_supported_ext_param ext_param; 391 struct sctp_adaptation_ind_param aiparam; 392 struct sctp_paramhdr *auth_chunks = NULL; 393 struct sctp_paramhdr *auth_random = NULL; 394 struct sctp_paramhdr *auth_hmacs = NULL; 395 struct sctp_chunk *retval = NULL; 396 struct sctp_cookie_param *cookie; 397 struct sctp_inithdr initack; 398 union sctp_params addrs; 399 struct sctp_sock *sp; 400 __u8 extensions[5]; 401 size_t chunksize; 402 int num_ext = 0; 403 int cookie_len; 404 int addrs_len; 405 406 /* Note: there may be no addresses to embed. */ 407 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp); 408 409 initack.init_tag = htonl(asoc->c.my_vtag); 410 initack.a_rwnd = htonl(asoc->rwnd); 411 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 412 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 413 initack.initial_tsn = htonl(asoc->c.initial_tsn); 414 415 /* FIXME: We really ought to build the cookie right 416 * into the packet instead of allocating more fresh memory. 417 */ 418 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len, 419 addrs.v, addrs_len); 420 if (!cookie) 421 goto nomem_cookie; 422 423 /* Calculate the total size of allocation, include the reserved 424 * space for reporting unknown parameters if it is specified. 425 */ 426 sp = sctp_sk(asoc->base.sk); 427 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len; 428 429 /* Tell peer that we'll do ECN only if peer advertised such cap. */ 430 if (asoc->peer.ecn_capable) 431 chunksize += sizeof(ecap_param); 432 433 if (asoc->peer.prsctp_capable) 434 chunksize += sizeof(prsctp_param); 435 436 if (asoc->peer.asconf_capable) { 437 extensions[num_ext] = SCTP_CID_ASCONF; 438 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 439 num_ext += 2; 440 } 441 442 if (asoc->peer.reconf_capable) { 443 extensions[num_ext] = SCTP_CID_RECONF; 444 num_ext += 1; 445 } 446 447 if (sp->adaptation_ind) 448 chunksize += sizeof(aiparam); 449 450 if (asoc->intl_enable) { 451 extensions[num_ext] = SCTP_CID_I_DATA; 452 num_ext += 1; 453 } 454 455 if (asoc->peer.auth_capable) { 456 auth_random = (struct sctp_paramhdr *)asoc->c.auth_random; 457 chunksize += ntohs(auth_random->length); 458 459 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; 460 if (auth_hmacs->length) 461 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 462 else 463 auth_hmacs = NULL; 464 465 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; 466 if (auth_chunks->length) 467 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 468 else 469 auth_chunks = NULL; 470 471 extensions[num_ext] = SCTP_CID_AUTH; 472 num_ext += 1; 473 } 474 475 if (num_ext) 476 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext); 477 478 /* Now allocate and fill out the chunk. */ 479 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp); 480 if (!retval) 481 goto nomem_chunk; 482 483 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 484 * 485 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 486 * HEARTBEAT ACK, * etc.) to the same destination transport 487 * address from which it received the DATA or control chunk 488 * to which it is replying. 489 * 490 * [INIT ACK back to where the INIT came from.] 491 */ 492 retval->transport = chunk->transport; 493 494 retval->subh.init_hdr = 495 sctp_addto_chunk(retval, sizeof(initack), &initack); 496 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); 497 sctp_addto_chunk(retval, cookie_len, cookie); 498 if (asoc->peer.ecn_capable) 499 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 500 if (num_ext) { 501 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 502 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext); 503 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); 504 sctp_addto_param(retval, num_ext, extensions); 505 } 506 if (asoc->peer.prsctp_capable) 507 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 508 509 if (sp->adaptation_ind) { 510 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 511 aiparam.param_hdr.length = htons(sizeof(aiparam)); 512 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 513 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 514 } 515 516 if (asoc->peer.auth_capable) { 517 sctp_addto_chunk(retval, ntohs(auth_random->length), 518 auth_random); 519 if (auth_hmacs) 520 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 521 auth_hmacs); 522 if (auth_chunks) 523 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 524 auth_chunks); 525 } 526 527 /* We need to remove the const qualifier at this point. */ 528 retval->asoc = (struct sctp_association *) asoc; 529 530 nomem_chunk: 531 kfree(cookie); 532 nomem_cookie: 533 kfree(addrs.v); 534 return retval; 535 } 536 537 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10): 538 * 539 * This chunk is used only during the initialization of an association. 540 * It is sent by the initiator of an association to its peer to complete 541 * the initialization process. This chunk MUST precede any DATA chunk 542 * sent within the association, but MAY be bundled with one or more DATA 543 * chunks in the same packet. 544 * 545 * 0 1 2 3 546 * 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 1 547 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 548 * | Type = 10 |Chunk Flags | Length | 549 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 550 * / Cookie / 551 * \ \ 552 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 553 * 554 * Chunk Flags: 8 bit 555 * 556 * Set to zero on transmit and ignored on receipt. 557 * 558 * Length: 16 bits (unsigned integer) 559 * 560 * Set to the size of the chunk in bytes, including the 4 bytes of 561 * the chunk header and the size of the Cookie. 562 * 563 * Cookie: variable size 564 * 565 * This field must contain the exact cookie received in the 566 * State Cookie parameter from the previous INIT ACK. 567 * 568 * An implementation SHOULD make the cookie as small as possible 569 * to insure interoperability. 570 */ 571 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, 572 const struct sctp_chunk *chunk) 573 { 574 struct sctp_chunk *retval; 575 int cookie_len; 576 void *cookie; 577 578 cookie = asoc->peer.cookie; 579 cookie_len = asoc->peer.cookie_len; 580 581 /* Build a cookie echo chunk. */ 582 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0, 583 cookie_len, GFP_ATOMIC); 584 if (!retval) 585 goto nodata; 586 retval->subh.cookie_hdr = 587 sctp_addto_chunk(retval, cookie_len, cookie); 588 589 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 590 * 591 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 592 * HEARTBEAT ACK, * etc.) to the same destination transport 593 * address from which it * received the DATA or control chunk 594 * to which it is replying. 595 * 596 * [COOKIE ECHO back to where the INIT ACK came from.] 597 */ 598 if (chunk) 599 retval->transport = chunk->transport; 600 601 nodata: 602 return retval; 603 } 604 605 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11): 606 * 607 * This chunk is used only during the initialization of an 608 * association. It is used to acknowledge the receipt of a COOKIE 609 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent 610 * within the association, but MAY be bundled with one or more DATA 611 * chunks or SACK chunk in the same SCTP packet. 612 * 613 * 0 1 2 3 614 * 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 1 615 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 616 * | Type = 11 |Chunk Flags | Length = 4 | 617 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 618 * 619 * Chunk Flags: 8 bits 620 * 621 * Set to zero on transmit and ignored on receipt. 622 */ 623 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, 624 const struct sctp_chunk *chunk) 625 { 626 struct sctp_chunk *retval; 627 628 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC); 629 630 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 631 * 632 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 633 * HEARTBEAT ACK, * etc.) to the same destination transport 634 * address from which it * received the DATA or control chunk 635 * to which it is replying. 636 * 637 * [COOKIE ACK back to where the COOKIE ECHO came from.] 638 */ 639 if (retval && chunk) 640 retval->transport = chunk->transport; 641 642 return retval; 643 } 644 645 /* 646 * Appendix A: Explicit Congestion Notification: 647 * CWR: 648 * 649 * RFC 2481 details a specific bit for a sender to send in the header of 650 * its next outbound TCP segment to indicate to its peer that it has 651 * reduced its congestion window. This is termed the CWR bit. For 652 * SCTP the same indication is made by including the CWR chunk. 653 * This chunk contains one data element, i.e. the TSN number that 654 * was sent in the ECNE chunk. This element represents the lowest 655 * TSN number in the datagram that was originally marked with the 656 * CE bit. 657 * 658 * 0 1 2 3 659 * 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 1 660 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 661 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 | 662 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 663 * | Lowest TSN Number | 664 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 665 * 666 * Note: The CWR is considered a Control chunk. 667 */ 668 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, 669 const __u32 lowest_tsn, 670 const struct sctp_chunk *chunk) 671 { 672 struct sctp_chunk *retval; 673 struct sctp_cwrhdr cwr; 674 675 cwr.lowest_tsn = htonl(lowest_tsn); 676 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0, 677 sizeof(cwr), GFP_ATOMIC); 678 679 if (!retval) 680 goto nodata; 681 682 retval->subh.ecn_cwr_hdr = 683 sctp_addto_chunk(retval, sizeof(cwr), &cwr); 684 685 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 686 * 687 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 688 * HEARTBEAT ACK, * etc.) to the same destination transport 689 * address from which it * received the DATA or control chunk 690 * to which it is replying. 691 * 692 * [Report a reduced congestion window back to where the ECNE 693 * came from.] 694 */ 695 if (chunk) 696 retval->transport = chunk->transport; 697 698 nodata: 699 return retval; 700 } 701 702 /* Make an ECNE chunk. This is a congestion experienced report. */ 703 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, 704 const __u32 lowest_tsn) 705 { 706 struct sctp_chunk *retval; 707 struct sctp_ecnehdr ecne; 708 709 ecne.lowest_tsn = htonl(lowest_tsn); 710 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0, 711 sizeof(ecne), GFP_ATOMIC); 712 if (!retval) 713 goto nodata; 714 retval->subh.ecne_hdr = 715 sctp_addto_chunk(retval, sizeof(ecne), &ecne); 716 717 nodata: 718 return retval; 719 } 720 721 /* Make a DATA chunk for the given association from the provided 722 * parameters. However, do not populate the data payload. 723 */ 724 struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc, 725 const struct sctp_sndrcvinfo *sinfo, 726 int len, __u8 flags, gfp_t gfp) 727 { 728 struct sctp_chunk *retval; 729 struct sctp_datahdr dp; 730 731 /* We assign the TSN as LATE as possible, not here when 732 * creating the chunk. 733 */ 734 memset(&dp, 0, sizeof(dp)); 735 dp.ppid = sinfo->sinfo_ppid; 736 dp.stream = htons(sinfo->sinfo_stream); 737 738 /* Set the flags for an unordered send. */ 739 if (sinfo->sinfo_flags & SCTP_UNORDERED) 740 flags |= SCTP_DATA_UNORDERED; 741 742 retval = sctp_make_data(asoc, flags, sizeof(dp) + len, gfp); 743 if (!retval) 744 return NULL; 745 746 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp); 747 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo)); 748 749 return retval; 750 } 751 752 /* Create a selective ackowledgement (SACK) for the given 753 * association. This reports on which TSN's we've seen to date, 754 * including duplicates and gaps. 755 */ 756 struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc) 757 { 758 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; 759 struct sctp_association *aptr = (struct sctp_association *)asoc; 760 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; 761 __u16 num_gabs, num_dup_tsns; 762 struct sctp_transport *trans; 763 struct sctp_chunk *retval; 764 struct sctp_sackhdr sack; 765 __u32 ctsn; 766 int len; 767 768 memset(gabs, 0, sizeof(gabs)); 769 ctsn = sctp_tsnmap_get_ctsn(map); 770 771 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn); 772 773 /* How much room is needed in the chunk? */ 774 num_gabs = sctp_tsnmap_num_gabs(map, gabs); 775 num_dup_tsns = sctp_tsnmap_num_dups(map); 776 777 /* Initialize the SACK header. */ 778 sack.cum_tsn_ack = htonl(ctsn); 779 sack.a_rwnd = htonl(asoc->a_rwnd); 780 sack.num_gap_ack_blocks = htons(num_gabs); 781 sack.num_dup_tsns = htons(num_dup_tsns); 782 783 len = sizeof(sack) 784 + sizeof(struct sctp_gap_ack_block) * num_gabs 785 + sizeof(__u32) * num_dup_tsns; 786 787 /* Create the chunk. */ 788 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC); 789 if (!retval) 790 goto nodata; 791 792 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 793 * 794 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 795 * HEARTBEAT ACK, etc.) to the same destination transport 796 * address from which it received the DATA or control chunk to 797 * which it is replying. This rule should also be followed if 798 * the endpoint is bundling DATA chunks together with the 799 * reply chunk. 800 * 801 * However, when acknowledging multiple DATA chunks received 802 * in packets from different source addresses in a single 803 * SACK, the SACK chunk may be transmitted to one of the 804 * destination transport addresses from which the DATA or 805 * control chunks being acknowledged were received. 806 * 807 * [BUG: We do not implement the following paragraph. 808 * Perhaps we should remember the last transport we used for a 809 * SACK and avoid that (if possible) if we have seen any 810 * duplicates. --piggy] 811 * 812 * When a receiver of a duplicate DATA chunk sends a SACK to a 813 * multi- homed endpoint it MAY be beneficial to vary the 814 * destination address and not use the source address of the 815 * DATA chunk. The reason being that receiving a duplicate 816 * from a multi-homed endpoint might indicate that the return 817 * path (as specified in the source address of the DATA chunk) 818 * for the SACK is broken. 819 * 820 * [Send to the address from which we last received a DATA chunk.] 821 */ 822 retval->transport = asoc->peer.last_data_from; 823 824 retval->subh.sack_hdr = 825 sctp_addto_chunk(retval, sizeof(sack), &sack); 826 827 /* Add the gap ack block information. */ 828 if (num_gabs) 829 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, 830 gabs); 831 832 /* Add the duplicate TSN information. */ 833 if (num_dup_tsns) { 834 aptr->stats.idupchunks += num_dup_tsns; 835 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, 836 sctp_tsnmap_get_dups(map)); 837 } 838 /* Once we have a sack generated, check to see what our sack 839 * generation is, if its 0, reset the transports to 0, and reset 840 * the association generation to 1 841 * 842 * The idea is that zero is never used as a valid generation for the 843 * association so no transport will match after a wrap event like this, 844 * Until the next sack 845 */ 846 if (++aptr->peer.sack_generation == 0) { 847 list_for_each_entry(trans, &asoc->peer.transport_addr_list, 848 transports) 849 trans->sack_generation = 0; 850 aptr->peer.sack_generation = 1; 851 } 852 nodata: 853 return retval; 854 } 855 856 /* Make a SHUTDOWN chunk. */ 857 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 858 const struct sctp_chunk *chunk) 859 { 860 struct sctp_shutdownhdr shut; 861 struct sctp_chunk *retval; 862 __u32 ctsn; 863 864 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 865 shut.cum_tsn_ack = htonl(ctsn); 866 867 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0, 868 sizeof(shut), GFP_ATOMIC); 869 if (!retval) 870 goto nodata; 871 872 retval->subh.shutdown_hdr = 873 sctp_addto_chunk(retval, sizeof(shut), &shut); 874 875 if (chunk) 876 retval->transport = chunk->transport; 877 nodata: 878 return retval; 879 } 880 881 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 882 const struct sctp_chunk *chunk) 883 { 884 struct sctp_chunk *retval; 885 886 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0, 887 GFP_ATOMIC); 888 889 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 890 * 891 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 892 * HEARTBEAT ACK, * etc.) to the same destination transport 893 * address from which it * received the DATA or control chunk 894 * to which it is replying. 895 * 896 * [ACK back to where the SHUTDOWN came from.] 897 */ 898 if (retval && chunk) 899 retval->transport = chunk->transport; 900 901 return retval; 902 } 903 904 struct sctp_chunk *sctp_make_shutdown_complete( 905 const struct sctp_association *asoc, 906 const struct sctp_chunk *chunk) 907 { 908 struct sctp_chunk *retval; 909 __u8 flags = 0; 910 911 /* Set the T-bit if we have no association (vtag will be 912 * reflected) 913 */ 914 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; 915 916 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 917 0, GFP_ATOMIC); 918 919 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 920 * 921 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 922 * HEARTBEAT ACK, * etc.) to the same destination transport 923 * address from which it * received the DATA or control chunk 924 * to which it is replying. 925 * 926 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK 927 * came from.] 928 */ 929 if (retval && chunk) 930 retval->transport = chunk->transport; 931 932 return retval; 933 } 934 935 /* Create an ABORT. Note that we set the T bit if we have no 936 * association, except when responding to an INIT (sctpimpguide 2.41). 937 */ 938 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 939 const struct sctp_chunk *chunk, 940 const size_t hint) 941 { 942 struct sctp_chunk *retval; 943 __u8 flags = 0; 944 945 /* Set the T-bit if we have no association and 'chunk' is not 946 * an INIT (vtag will be reflected). 947 */ 948 if (!asoc) { 949 if (chunk && chunk->chunk_hdr && 950 chunk->chunk_hdr->type == SCTP_CID_INIT) 951 flags = 0; 952 else 953 flags = SCTP_CHUNK_FLAG_T; 954 } 955 956 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint, 957 GFP_ATOMIC); 958 959 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 960 * 961 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 962 * HEARTBEAT ACK, * etc.) to the same destination transport 963 * address from which it * received the DATA or control chunk 964 * to which it is replying. 965 * 966 * [ABORT back to where the offender came from.] 967 */ 968 if (retval && chunk) 969 retval->transport = chunk->transport; 970 971 return retval; 972 } 973 974 /* Helper to create ABORT with a NO_USER_DATA error. */ 975 struct sctp_chunk *sctp_make_abort_no_data( 976 const struct sctp_association *asoc, 977 const struct sctp_chunk *chunk, 978 __u32 tsn) 979 { 980 struct sctp_chunk *retval; 981 __be32 payload; 982 983 retval = sctp_make_abort(asoc, chunk, 984 sizeof(struct sctp_errhdr) + sizeof(tsn)); 985 986 if (!retval) 987 goto no_mem; 988 989 /* Put the tsn back into network byte order. */ 990 payload = htonl(tsn); 991 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload)); 992 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload); 993 994 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 995 * 996 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 997 * HEARTBEAT ACK, * etc.) to the same destination transport 998 * address from which it * received the DATA or control chunk 999 * to which it is replying. 1000 * 1001 * [ABORT back to where the offender came from.] 1002 */ 1003 if (chunk) 1004 retval->transport = chunk->transport; 1005 1006 no_mem: 1007 return retval; 1008 } 1009 1010 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ 1011 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 1012 struct msghdr *msg, 1013 size_t paylen) 1014 { 1015 struct sctp_chunk *retval; 1016 void *payload = NULL; 1017 int err; 1018 1019 retval = sctp_make_abort(asoc, NULL, 1020 sizeof(struct sctp_errhdr) + paylen); 1021 if (!retval) 1022 goto err_chunk; 1023 1024 if (paylen) { 1025 /* Put the msg_iov together into payload. */ 1026 payload = kmalloc(paylen, GFP_KERNEL); 1027 if (!payload) 1028 goto err_payload; 1029 1030 err = memcpy_from_msg(payload, msg, paylen); 1031 if (err < 0) 1032 goto err_copy; 1033 } 1034 1035 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); 1036 sctp_addto_chunk(retval, paylen, payload); 1037 1038 if (paylen) 1039 kfree(payload); 1040 1041 return retval; 1042 1043 err_copy: 1044 kfree(payload); 1045 err_payload: 1046 sctp_chunk_free(retval); 1047 retval = NULL; 1048 err_chunk: 1049 return retval; 1050 } 1051 1052 /* Append bytes to the end of a parameter. Will panic if chunk is not big 1053 * enough. 1054 */ 1055 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 1056 const void *data) 1057 { 1058 int chunklen = ntohs(chunk->chunk_hdr->length); 1059 void *target; 1060 1061 target = skb_put(chunk->skb, len); 1062 1063 if (data) 1064 memcpy(target, data, len); 1065 else 1066 memset(target, 0, len); 1067 1068 /* Adjust the chunk length field. */ 1069 chunk->chunk_hdr->length = htons(chunklen + len); 1070 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1071 1072 return target; 1073 } 1074 1075 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ 1076 struct sctp_chunk *sctp_make_abort_violation( 1077 const struct sctp_association *asoc, 1078 const struct sctp_chunk *chunk, 1079 const __u8 *payload, 1080 const size_t paylen) 1081 { 1082 struct sctp_chunk *retval; 1083 struct sctp_paramhdr phdr; 1084 1085 retval = sctp_make_abort(asoc, chunk, sizeof(struct sctp_errhdr) + 1086 paylen + sizeof(phdr)); 1087 if (!retval) 1088 goto end; 1089 1090 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen + 1091 sizeof(phdr)); 1092 1093 phdr.type = htons(chunk->chunk_hdr->type); 1094 phdr.length = chunk->chunk_hdr->length; 1095 sctp_addto_chunk(retval, paylen, payload); 1096 sctp_addto_param(retval, sizeof(phdr), &phdr); 1097 1098 end: 1099 return retval; 1100 } 1101 1102 struct sctp_chunk *sctp_make_violation_paramlen( 1103 const struct sctp_association *asoc, 1104 const struct sctp_chunk *chunk, 1105 struct sctp_paramhdr *param) 1106 { 1107 static const char error[] = "The following parameter had invalid length:"; 1108 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr) + 1109 sizeof(*param); 1110 struct sctp_chunk *retval; 1111 1112 retval = sctp_make_abort(asoc, chunk, payload_len); 1113 if (!retval) 1114 goto nodata; 1115 1116 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, 1117 sizeof(error) + sizeof(*param)); 1118 sctp_addto_chunk(retval, sizeof(error), error); 1119 sctp_addto_param(retval, sizeof(*param), param); 1120 1121 nodata: 1122 return retval; 1123 } 1124 1125 struct sctp_chunk *sctp_make_violation_max_retrans( 1126 const struct sctp_association *asoc, 1127 const struct sctp_chunk *chunk) 1128 { 1129 static const char error[] = "Association exceeded its max_retans count"; 1130 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr); 1131 struct sctp_chunk *retval; 1132 1133 retval = sctp_make_abort(asoc, chunk, payload_len); 1134 if (!retval) 1135 goto nodata; 1136 1137 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error)); 1138 sctp_addto_chunk(retval, sizeof(error), error); 1139 1140 nodata: 1141 return retval; 1142 } 1143 1144 /* Make a HEARTBEAT chunk. */ 1145 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1146 const struct sctp_transport *transport) 1147 { 1148 struct sctp_sender_hb_info hbinfo; 1149 struct sctp_chunk *retval; 1150 1151 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, 1152 sizeof(hbinfo), GFP_ATOMIC); 1153 1154 if (!retval) 1155 goto nodata; 1156 1157 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; 1158 hbinfo.param_hdr.length = htons(sizeof(hbinfo)); 1159 hbinfo.daddr = transport->ipaddr; 1160 hbinfo.sent_at = jiffies; 1161 hbinfo.hb_nonce = transport->hb_nonce; 1162 1163 /* Cast away the 'const', as this is just telling the chunk 1164 * what transport it belongs to. 1165 */ 1166 retval->transport = (struct sctp_transport *) transport; 1167 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo), 1168 &hbinfo); 1169 1170 nodata: 1171 return retval; 1172 } 1173 1174 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1175 const struct sctp_chunk *chunk, 1176 const void *payload, 1177 const size_t paylen) 1178 { 1179 struct sctp_chunk *retval; 1180 1181 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen, 1182 GFP_ATOMIC); 1183 if (!retval) 1184 goto nodata; 1185 1186 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1187 1188 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1189 * 1190 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1191 * HEARTBEAT ACK, * etc.) to the same destination transport 1192 * address from which it * received the DATA or control chunk 1193 * to which it is replying. 1194 * 1195 * [HBACK back to where the HEARTBEAT came from.] 1196 */ 1197 if (chunk) 1198 retval->transport = chunk->transport; 1199 1200 nodata: 1201 return retval; 1202 } 1203 1204 /* Create an Operation Error chunk with the specified space reserved. 1205 * This routine can be used for containing multiple causes in the chunk. 1206 */ 1207 static struct sctp_chunk *sctp_make_op_error_space( 1208 const struct sctp_association *asoc, 1209 const struct sctp_chunk *chunk, 1210 size_t size) 1211 { 1212 struct sctp_chunk *retval; 1213 1214 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0, 1215 sizeof(struct sctp_errhdr) + size, 1216 GFP_ATOMIC); 1217 if (!retval) 1218 goto nodata; 1219 1220 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1221 * 1222 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1223 * HEARTBEAT ACK, etc.) to the same destination transport 1224 * address from which it received the DATA or control chunk 1225 * to which it is replying. 1226 * 1227 */ 1228 if (chunk) 1229 retval->transport = chunk->transport; 1230 1231 nodata: 1232 return retval; 1233 } 1234 1235 /* Create an Operation Error chunk of a fixed size, 1236 * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) 1237 * This is a helper function to allocate an error chunk for 1238 * for those invalid parameter codes in which we may not want 1239 * to report all the errors, if the incoming chunk is large 1240 */ 1241 static inline struct sctp_chunk *sctp_make_op_error_fixed( 1242 const struct sctp_association *asoc, 1243 const struct sctp_chunk *chunk) 1244 { 1245 size_t size = asoc ? asoc->pathmtu : 0; 1246 1247 if (!size) 1248 size = SCTP_DEFAULT_MAXSEGMENT; 1249 1250 return sctp_make_op_error_space(asoc, chunk, size); 1251 } 1252 1253 /* Create an Operation Error chunk. */ 1254 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1255 const struct sctp_chunk *chunk, 1256 __be16 cause_code, const void *payload, 1257 size_t paylen, size_t reserve_tail) 1258 { 1259 struct sctp_chunk *retval; 1260 1261 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); 1262 if (!retval) 1263 goto nodata; 1264 1265 sctp_init_cause(retval, cause_code, paylen + reserve_tail); 1266 sctp_addto_chunk(retval, paylen, payload); 1267 if (reserve_tail) 1268 sctp_addto_param(retval, reserve_tail, NULL); 1269 1270 nodata: 1271 return retval; 1272 } 1273 1274 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc) 1275 { 1276 struct sctp_authhdr auth_hdr; 1277 struct sctp_hmac *hmac_desc; 1278 struct sctp_chunk *retval; 1279 1280 /* Get the first hmac that the peer told us to use */ 1281 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1282 if (unlikely(!hmac_desc)) 1283 return NULL; 1284 1285 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0, 1286 hmac_desc->hmac_len + sizeof(auth_hdr), 1287 GFP_ATOMIC); 1288 if (!retval) 1289 return NULL; 1290 1291 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1292 auth_hdr.shkey_id = htons(asoc->active_key_id); 1293 1294 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr), 1295 &auth_hdr); 1296 1297 skb_put_zero(retval->skb, hmac_desc->hmac_len); 1298 1299 /* Adjust the chunk header to include the empty MAC */ 1300 retval->chunk_hdr->length = 1301 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1302 retval->chunk_end = skb_tail_pointer(retval->skb); 1303 1304 return retval; 1305 } 1306 1307 1308 /******************************************************************** 1309 * 2nd Level Abstractions 1310 ********************************************************************/ 1311 1312 /* Turn an skb into a chunk. 1313 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1314 * 1315 * sctpimpguide-05.txt Section 2.8.2 1316 * M1) Each time a new DATA chunk is transmitted 1317 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1318 * 'TSN.Missing.Report' count will be used to determine missing chunks 1319 * and when to fast retransmit. 1320 * 1321 */ 1322 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1323 const struct sctp_association *asoc, 1324 struct sock *sk, gfp_t gfp) 1325 { 1326 struct sctp_chunk *retval; 1327 1328 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp); 1329 1330 if (!retval) 1331 goto nodata; 1332 if (!sk) 1333 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb); 1334 1335 INIT_LIST_HEAD(&retval->list); 1336 retval->skb = skb; 1337 retval->asoc = (struct sctp_association *)asoc; 1338 retval->singleton = 1; 1339 1340 retval->fast_retransmit = SCTP_CAN_FRTX; 1341 1342 /* Polish the bead hole. */ 1343 INIT_LIST_HEAD(&retval->transmitted_list); 1344 INIT_LIST_HEAD(&retval->frag_list); 1345 SCTP_DBG_OBJCNT_INC(chunk); 1346 refcount_set(&retval->refcnt, 1); 1347 1348 nodata: 1349 return retval; 1350 } 1351 1352 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1353 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1354 union sctp_addr *dest) 1355 { 1356 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1357 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1358 } 1359 1360 /* Extract the source address from a chunk. */ 1361 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1362 { 1363 /* If we have a known transport, use that. */ 1364 if (chunk->transport) { 1365 return &chunk->transport->ipaddr; 1366 } else { 1367 /* Otherwise, extract it from the IP header. */ 1368 return &chunk->source; 1369 } 1370 } 1371 1372 /* Create a new chunk, setting the type and flags headers from the 1373 * arguments, reserving enough space for a 'paylen' byte payload. 1374 */ 1375 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 1376 __u8 type, __u8 flags, int paylen, 1377 gfp_t gfp) 1378 { 1379 struct sctp_chunkhdr *chunk_hdr; 1380 struct sctp_chunk *retval; 1381 struct sk_buff *skb; 1382 struct sock *sk; 1383 int chunklen; 1384 1385 chunklen = SCTP_PAD4(sizeof(*chunk_hdr) + paylen); 1386 if (chunklen > SCTP_MAX_CHUNK_LEN) 1387 goto nodata; 1388 1389 /* No need to allocate LL here, as this is only a chunk. */ 1390 skb = alloc_skb(chunklen, gfp); 1391 if (!skb) 1392 goto nodata; 1393 1394 /* Make room for the chunk header. */ 1395 chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr)); 1396 chunk_hdr->type = type; 1397 chunk_hdr->flags = flags; 1398 chunk_hdr->length = htons(sizeof(*chunk_hdr)); 1399 1400 sk = asoc ? asoc->base.sk : NULL; 1401 retval = sctp_chunkify(skb, asoc, sk, gfp); 1402 if (!retval) { 1403 kfree_skb(skb); 1404 goto nodata; 1405 } 1406 1407 retval->chunk_hdr = chunk_hdr; 1408 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr); 1409 1410 /* Determine if the chunk needs to be authenticated */ 1411 if (sctp_auth_send_cid(type, asoc)) 1412 retval->auth = 1; 1413 1414 return retval; 1415 nodata: 1416 return NULL; 1417 } 1418 1419 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 1420 __u8 flags, int paylen, gfp_t gfp) 1421 { 1422 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp); 1423 } 1424 1425 struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc, 1426 __u8 flags, int paylen, gfp_t gfp) 1427 { 1428 return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp); 1429 } 1430 1431 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 1432 __u8 type, __u8 flags, int paylen, 1433 gfp_t gfp) 1434 { 1435 struct sctp_chunk *chunk; 1436 1437 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp); 1438 if (chunk) 1439 sctp_control_set_owner_w(chunk); 1440 1441 return chunk; 1442 } 1443 1444 /* Release the memory occupied by a chunk. */ 1445 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1446 { 1447 BUG_ON(!list_empty(&chunk->list)); 1448 list_del_init(&chunk->transmitted_list); 1449 1450 consume_skb(chunk->skb); 1451 consume_skb(chunk->auth_chunk); 1452 1453 SCTP_DBG_OBJCNT_DEC(chunk); 1454 kmem_cache_free(sctp_chunk_cachep, chunk); 1455 } 1456 1457 /* Possibly, free the chunk. */ 1458 void sctp_chunk_free(struct sctp_chunk *chunk) 1459 { 1460 /* Release our reference on the message tracker. */ 1461 if (chunk->msg) 1462 sctp_datamsg_put(chunk->msg); 1463 1464 sctp_chunk_put(chunk); 1465 } 1466 1467 /* Grab a reference to the chunk. */ 1468 void sctp_chunk_hold(struct sctp_chunk *ch) 1469 { 1470 refcount_inc(&ch->refcnt); 1471 } 1472 1473 /* Release a reference to the chunk. */ 1474 void sctp_chunk_put(struct sctp_chunk *ch) 1475 { 1476 if (refcount_dec_and_test(&ch->refcnt)) 1477 sctp_chunk_destroy(ch); 1478 } 1479 1480 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1481 * enough. 1482 */ 1483 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1484 { 1485 int chunklen = ntohs(chunk->chunk_hdr->length); 1486 int padlen = SCTP_PAD4(chunklen) - chunklen; 1487 void *target; 1488 1489 skb_put_zero(chunk->skb, padlen); 1490 target = skb_put_data(chunk->skb, data, len); 1491 1492 /* Adjust the chunk length field. */ 1493 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1494 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1495 1496 return target; 1497 } 1498 1499 /* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient 1500 * space in the chunk 1501 */ 1502 static void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk, 1503 int len, const void *data) 1504 { 1505 if (skb_tailroom(chunk->skb) >= len) 1506 return sctp_addto_chunk(chunk, len, data); 1507 else 1508 return NULL; 1509 } 1510 1511 /* Append bytes from user space to the end of a chunk. Will panic if 1512 * chunk is not big enough. 1513 * Returns a kernel err value. 1514 */ 1515 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len, 1516 struct iov_iter *from) 1517 { 1518 void *target; 1519 1520 /* Make room in chunk for data. */ 1521 target = skb_put(chunk->skb, len); 1522 1523 /* Copy data (whole iovec) into chunk */ 1524 if (!copy_from_iter_full(target, len, from)) 1525 return -EFAULT; 1526 1527 /* Adjust the chunk length field. */ 1528 chunk->chunk_hdr->length = 1529 htons(ntohs(chunk->chunk_hdr->length) + len); 1530 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1531 1532 return 0; 1533 } 1534 1535 /* Helper function to assign a TSN if needed. This assumes that both 1536 * the data_hdr and association have already been assigned. 1537 */ 1538 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1539 { 1540 struct sctp_stream *stream; 1541 struct sctp_chunk *lchunk; 1542 struct sctp_datamsg *msg; 1543 __u16 ssn, sid; 1544 1545 if (chunk->has_ssn) 1546 return; 1547 1548 /* All fragments will be on the same stream */ 1549 sid = ntohs(chunk->subh.data_hdr->stream); 1550 stream = &chunk->asoc->stream; 1551 1552 /* Now assign the sequence number to the entire message. 1553 * All fragments must have the same stream sequence number. 1554 */ 1555 msg = chunk->msg; 1556 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1557 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1558 ssn = 0; 1559 } else { 1560 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1561 ssn = sctp_ssn_next(stream, out, sid); 1562 else 1563 ssn = sctp_ssn_peek(stream, out, sid); 1564 } 1565 1566 lchunk->subh.data_hdr->ssn = htons(ssn); 1567 lchunk->has_ssn = 1; 1568 } 1569 } 1570 1571 /* Helper function to assign a TSN if needed. This assumes that both 1572 * the data_hdr and association have already been assigned. 1573 */ 1574 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1575 { 1576 if (!chunk->has_tsn) { 1577 /* This is the last possible instant to 1578 * assign a TSN. 1579 */ 1580 chunk->subh.data_hdr->tsn = 1581 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1582 chunk->has_tsn = 1; 1583 } 1584 } 1585 1586 /* Create a CLOSED association to use with an incoming packet. */ 1587 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1588 struct sctp_chunk *chunk, 1589 gfp_t gfp) 1590 { 1591 struct sctp_association *asoc; 1592 enum sctp_scope scope; 1593 struct sk_buff *skb; 1594 1595 /* Create the bare association. */ 1596 scope = sctp_scope(sctp_source(chunk)); 1597 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1598 if (!asoc) 1599 goto nodata; 1600 asoc->temp = 1; 1601 skb = chunk->skb; 1602 /* Create an entry for the source address of the packet. */ 1603 SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1); 1604 1605 nodata: 1606 return asoc; 1607 } 1608 1609 /* Build a cookie representing asoc. 1610 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1611 */ 1612 static struct sctp_cookie_param *sctp_pack_cookie( 1613 const struct sctp_endpoint *ep, 1614 const struct sctp_association *asoc, 1615 const struct sctp_chunk *init_chunk, 1616 int *cookie_len, const __u8 *raw_addrs, 1617 int addrs_len) 1618 { 1619 struct sctp_signed_cookie *cookie; 1620 struct sctp_cookie_param *retval; 1621 int headersize, bodysize; 1622 1623 /* Header size is static data prior to the actual cookie, including 1624 * any padding. 1625 */ 1626 headersize = sizeof(struct sctp_paramhdr) + 1627 (sizeof(struct sctp_signed_cookie) - 1628 sizeof(struct sctp_cookie)); 1629 bodysize = sizeof(struct sctp_cookie) 1630 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1631 1632 /* Pad out the cookie to a multiple to make the signature 1633 * functions simpler to write. 1634 */ 1635 if (bodysize % SCTP_COOKIE_MULTIPLE) 1636 bodysize += SCTP_COOKIE_MULTIPLE 1637 - (bodysize % SCTP_COOKIE_MULTIPLE); 1638 *cookie_len = headersize + bodysize; 1639 1640 /* Clear this memory since we are sending this data structure 1641 * out on the network. 1642 */ 1643 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1644 if (!retval) 1645 goto nodata; 1646 1647 cookie = (struct sctp_signed_cookie *) retval->body; 1648 1649 /* Set up the parameter header. */ 1650 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1651 retval->p.length = htons(*cookie_len); 1652 1653 /* Copy the cookie part of the association itself. */ 1654 cookie->c = asoc->c; 1655 /* Save the raw address list length in the cookie. */ 1656 cookie->c.raw_addr_list_len = addrs_len; 1657 1658 /* Remember PR-SCTP capability. */ 1659 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1660 1661 /* Save adaptation indication in the cookie. */ 1662 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1663 1664 /* Set an expiration time for the cookie. */ 1665 cookie->c.expiration = ktime_add(asoc->cookie_life, 1666 ktime_get_real()); 1667 1668 /* Copy the peer's init packet. */ 1669 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr, 1670 ntohs(init_chunk->chunk_hdr->length)); 1671 1672 /* Copy the raw local address list of the association. */ 1673 memcpy((__u8 *)&cookie->c.peer_init[0] + 1674 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1675 1676 if (sctp_sk(ep->base.sk)->hmac) { 1677 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac); 1678 int err; 1679 1680 /* Sign the message. */ 1681 desc->tfm = sctp_sk(ep->base.sk)->hmac; 1682 desc->flags = 0; 1683 1684 err = crypto_shash_setkey(desc->tfm, ep->secret_key, 1685 sizeof(ep->secret_key)) ?: 1686 crypto_shash_digest(desc, (u8 *)&cookie->c, bodysize, 1687 cookie->signature); 1688 shash_desc_zero(desc); 1689 if (err) 1690 goto free_cookie; 1691 } 1692 1693 return retval; 1694 1695 free_cookie: 1696 kfree(retval); 1697 nodata: 1698 *cookie_len = 0; 1699 return NULL; 1700 } 1701 1702 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1703 struct sctp_association *sctp_unpack_cookie( 1704 const struct sctp_endpoint *ep, 1705 const struct sctp_association *asoc, 1706 struct sctp_chunk *chunk, gfp_t gfp, 1707 int *error, struct sctp_chunk **errp) 1708 { 1709 struct sctp_association *retval = NULL; 1710 int headersize, bodysize, fixed_size; 1711 struct sctp_signed_cookie *cookie; 1712 struct sk_buff *skb = chunk->skb; 1713 struct sctp_cookie *bear_cookie; 1714 __u8 *digest = ep->digest; 1715 enum sctp_scope scope; 1716 unsigned int len; 1717 ktime_t kt; 1718 1719 /* Header size is static data prior to the actual cookie, including 1720 * any padding. 1721 */ 1722 headersize = sizeof(struct sctp_chunkhdr) + 1723 (sizeof(struct sctp_signed_cookie) - 1724 sizeof(struct sctp_cookie)); 1725 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1726 fixed_size = headersize + sizeof(struct sctp_cookie); 1727 1728 /* Verify that the chunk looks like it even has a cookie. 1729 * There must be enough room for our cookie and our peer's 1730 * INIT chunk. 1731 */ 1732 len = ntohs(chunk->chunk_hdr->length); 1733 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1734 goto malformed; 1735 1736 /* Verify that the cookie has been padded out. */ 1737 if (bodysize % SCTP_COOKIE_MULTIPLE) 1738 goto malformed; 1739 1740 /* Process the cookie. */ 1741 cookie = chunk->subh.cookie_hdr; 1742 bear_cookie = &cookie->c; 1743 1744 if (!sctp_sk(ep->base.sk)->hmac) 1745 goto no_hmac; 1746 1747 /* Check the signature. */ 1748 { 1749 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac); 1750 int err; 1751 1752 desc->tfm = sctp_sk(ep->base.sk)->hmac; 1753 desc->flags = 0; 1754 1755 err = crypto_shash_setkey(desc->tfm, ep->secret_key, 1756 sizeof(ep->secret_key)) ?: 1757 crypto_shash_digest(desc, (u8 *)bear_cookie, bodysize, 1758 digest); 1759 shash_desc_zero(desc); 1760 1761 if (err) { 1762 *error = -SCTP_IERROR_NOMEM; 1763 goto fail; 1764 } 1765 } 1766 1767 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1768 *error = -SCTP_IERROR_BAD_SIG; 1769 goto fail; 1770 } 1771 1772 no_hmac: 1773 /* IG Section 2.35.2: 1774 * 3) Compare the port numbers and the verification tag contained 1775 * within the COOKIE ECHO chunk to the actual port numbers and the 1776 * verification tag within the SCTP common header of the received 1777 * packet. If these values do not match the packet MUST be silently 1778 * discarded, 1779 */ 1780 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1781 *error = -SCTP_IERROR_BAD_TAG; 1782 goto fail; 1783 } 1784 1785 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1786 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1787 *error = -SCTP_IERROR_BAD_PORTS; 1788 goto fail; 1789 } 1790 1791 /* Check to see if the cookie is stale. If there is already 1792 * an association, there is no need to check cookie's expiration 1793 * for init collision case of lost COOKIE ACK. 1794 * If skb has been timestamped, then use the stamp, otherwise 1795 * use current time. This introduces a small possibility that 1796 * that a cookie may be considered expired, but his would only slow 1797 * down the new association establishment instead of every packet. 1798 */ 1799 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1800 kt = skb_get_ktime(skb); 1801 else 1802 kt = ktime_get_real(); 1803 1804 if (!asoc && ktime_before(bear_cookie->expiration, kt)) { 1805 /* 1806 * Section 3.3.10.3 Stale Cookie Error (3) 1807 * 1808 * Cause of error 1809 * --------------- 1810 * Stale Cookie Error: Indicates the receipt of a valid State 1811 * Cookie that has expired. 1812 */ 1813 len = ntohs(chunk->chunk_hdr->length); 1814 *errp = sctp_make_op_error_space(asoc, chunk, len); 1815 if (*errp) { 1816 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); 1817 __be32 n = htonl(usecs); 1818 1819 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE, 1820 sizeof(n)); 1821 sctp_addto_chunk(*errp, sizeof(n), &n); 1822 *error = -SCTP_IERROR_STALE_COOKIE; 1823 } else 1824 *error = -SCTP_IERROR_NOMEM; 1825 1826 goto fail; 1827 } 1828 1829 /* Make a new base association. */ 1830 scope = sctp_scope(sctp_source(chunk)); 1831 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1832 if (!retval) { 1833 *error = -SCTP_IERROR_NOMEM; 1834 goto fail; 1835 } 1836 1837 /* Set up our peer's port number. */ 1838 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1839 1840 /* Populate the association from the cookie. */ 1841 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1842 1843 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1844 GFP_ATOMIC) < 0) { 1845 *error = -SCTP_IERROR_NOMEM; 1846 goto fail; 1847 } 1848 1849 /* Also, add the destination address. */ 1850 if (list_empty(&retval->base.bind_addr.address_list)) { 1851 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1852 sizeof(chunk->dest), SCTP_ADDR_SRC, 1853 GFP_ATOMIC); 1854 } 1855 1856 retval->next_tsn = retval->c.initial_tsn; 1857 retval->ctsn_ack_point = retval->next_tsn - 1; 1858 retval->addip_serial = retval->c.initial_tsn; 1859 retval->strreset_outseq = retval->c.initial_tsn; 1860 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1861 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1862 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1863 1864 /* The INIT stuff will be done by the side effects. */ 1865 return retval; 1866 1867 fail: 1868 if (retval) 1869 sctp_association_free(retval); 1870 1871 return NULL; 1872 1873 malformed: 1874 /* Yikes! The packet is either corrupt or deliberately 1875 * malformed. 1876 */ 1877 *error = -SCTP_IERROR_MALFORMED; 1878 goto fail; 1879 } 1880 1881 /******************************************************************** 1882 * 3rd Level Abstractions 1883 ********************************************************************/ 1884 1885 struct __sctp_missing { 1886 __be32 num_missing; 1887 __be16 type; 1888 } __packed; 1889 1890 /* 1891 * Report a missing mandatory parameter. 1892 */ 1893 static int sctp_process_missing_param(const struct sctp_association *asoc, 1894 enum sctp_param paramtype, 1895 struct sctp_chunk *chunk, 1896 struct sctp_chunk **errp) 1897 { 1898 struct __sctp_missing report; 1899 __u16 len; 1900 1901 len = SCTP_PAD4(sizeof(report)); 1902 1903 /* Make an ERROR chunk, preparing enough room for 1904 * returning multiple unknown parameters. 1905 */ 1906 if (!*errp) 1907 *errp = sctp_make_op_error_space(asoc, chunk, len); 1908 1909 if (*errp) { 1910 report.num_missing = htonl(1); 1911 report.type = paramtype; 1912 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1913 sizeof(report)); 1914 sctp_addto_chunk(*errp, sizeof(report), &report); 1915 } 1916 1917 /* Stop processing this chunk. */ 1918 return 0; 1919 } 1920 1921 /* Report an Invalid Mandatory Parameter. */ 1922 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1923 struct sctp_chunk *chunk, 1924 struct sctp_chunk **errp) 1925 { 1926 /* Invalid Mandatory Parameter Error has no payload. */ 1927 1928 if (!*errp) 1929 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1930 1931 if (*errp) 1932 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1933 1934 /* Stop processing this chunk. */ 1935 return 0; 1936 } 1937 1938 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1939 struct sctp_paramhdr *param, 1940 const struct sctp_chunk *chunk, 1941 struct sctp_chunk **errp) 1942 { 1943 /* This is a fatal error. Any accumulated non-fatal errors are 1944 * not reported. 1945 */ 1946 if (*errp) 1947 sctp_chunk_free(*errp); 1948 1949 /* Create an error chunk and fill it in with our payload. */ 1950 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1951 1952 return 0; 1953 } 1954 1955 1956 /* Do not attempt to handle the HOST_NAME parm. However, do 1957 * send back an indicator to the peer. 1958 */ 1959 static int sctp_process_hn_param(const struct sctp_association *asoc, 1960 union sctp_params param, 1961 struct sctp_chunk *chunk, 1962 struct sctp_chunk **errp) 1963 { 1964 __u16 len = ntohs(param.p->length); 1965 1966 /* Processing of the HOST_NAME parameter will generate an 1967 * ABORT. If we've accumulated any non-fatal errors, they 1968 * would be unrecognized parameters and we should not include 1969 * them in the ABORT. 1970 */ 1971 if (*errp) 1972 sctp_chunk_free(*errp); 1973 1974 *errp = sctp_make_op_error_space(asoc, chunk, len); 1975 1976 if (*errp) { 1977 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len); 1978 sctp_addto_chunk(*errp, len, param.v); 1979 } 1980 1981 /* Stop processing this chunk. */ 1982 return 0; 1983 } 1984 1985 static int sctp_verify_ext_param(struct net *net, union sctp_params param) 1986 { 1987 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 1988 int have_asconf = 0; 1989 int have_auth = 0; 1990 int i; 1991 1992 for (i = 0; i < num_ext; i++) { 1993 switch (param.ext->chunks[i]) { 1994 case SCTP_CID_AUTH: 1995 have_auth = 1; 1996 break; 1997 case SCTP_CID_ASCONF: 1998 case SCTP_CID_ASCONF_ACK: 1999 have_asconf = 1; 2000 break; 2001 } 2002 } 2003 2004 /* ADD-IP Security: The draft requires us to ABORT or ignore the 2005 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 2006 * only if ADD-IP is turned on and we are not backward-compatible 2007 * mode. 2008 */ 2009 if (net->sctp.addip_noauth) 2010 return 1; 2011 2012 if (net->sctp.addip_enable && !have_auth && have_asconf) 2013 return 0; 2014 2015 return 1; 2016 } 2017 2018 static void sctp_process_ext_param(struct sctp_association *asoc, 2019 union sctp_params param) 2020 { 2021 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2022 struct net *net = sock_net(asoc->base.sk); 2023 int i; 2024 2025 for (i = 0; i < num_ext; i++) { 2026 switch (param.ext->chunks[i]) { 2027 case SCTP_CID_RECONF: 2028 if (asoc->reconf_enable && 2029 !asoc->peer.reconf_capable) 2030 asoc->peer.reconf_capable = 1; 2031 break; 2032 case SCTP_CID_FWD_TSN: 2033 if (asoc->prsctp_enable && !asoc->peer.prsctp_capable) 2034 asoc->peer.prsctp_capable = 1; 2035 break; 2036 case SCTP_CID_AUTH: 2037 /* if the peer reports AUTH, assume that he 2038 * supports AUTH. 2039 */ 2040 if (asoc->ep->auth_enable) 2041 asoc->peer.auth_capable = 1; 2042 break; 2043 case SCTP_CID_ASCONF: 2044 case SCTP_CID_ASCONF_ACK: 2045 if (net->sctp.addip_enable) 2046 asoc->peer.asconf_capable = 1; 2047 break; 2048 case SCTP_CID_I_DATA: 2049 if (sctp_sk(asoc->base.sk)->strm_interleave) 2050 asoc->intl_enable = 1; 2051 break; 2052 default: 2053 break; 2054 } 2055 } 2056 } 2057 2058 /* RFC 3.2.1 & the Implementers Guide 2.2. 2059 * 2060 * The Parameter Types are encoded such that the 2061 * highest-order two bits specify the action that must be 2062 * taken if the processing endpoint does not recognize the 2063 * Parameter Type. 2064 * 2065 * 00 - Stop processing this parameter; do not process any further 2066 * parameters within this chunk 2067 * 2068 * 01 - Stop processing this parameter, do not process any further 2069 * parameters within this chunk, and report the unrecognized 2070 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2071 * 2072 * 10 - Skip this parameter and continue processing. 2073 * 2074 * 11 - Skip this parameter and continue processing but 2075 * report the unrecognized parameter in an 2076 * 'Unrecognized Parameter' ERROR chunk. 2077 * 2078 * Return value: 2079 * SCTP_IERROR_NO_ERROR - continue with the chunk 2080 * SCTP_IERROR_ERROR - stop and report an error. 2081 * SCTP_IERROR_NOMEME - out of memory. 2082 */ 2083 static enum sctp_ierror sctp_process_unk_param( 2084 const struct sctp_association *asoc, 2085 union sctp_params param, 2086 struct sctp_chunk *chunk, 2087 struct sctp_chunk **errp) 2088 { 2089 int retval = SCTP_IERROR_NO_ERROR; 2090 2091 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2092 case SCTP_PARAM_ACTION_DISCARD: 2093 retval = SCTP_IERROR_ERROR; 2094 break; 2095 case SCTP_PARAM_ACTION_SKIP: 2096 break; 2097 case SCTP_PARAM_ACTION_DISCARD_ERR: 2098 retval = SCTP_IERROR_ERROR; 2099 /* Fall through */ 2100 case SCTP_PARAM_ACTION_SKIP_ERR: 2101 /* Make an ERROR chunk, preparing enough room for 2102 * returning multiple unknown parameters. 2103 */ 2104 if (NULL == *errp) 2105 *errp = sctp_make_op_error_fixed(asoc, chunk); 2106 2107 if (*errp) { 2108 if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2109 SCTP_PAD4(ntohs(param.p->length)))) 2110 sctp_addto_chunk_fixed(*errp, 2111 SCTP_PAD4(ntohs(param.p->length)), 2112 param.v); 2113 } else { 2114 /* If there is no memory for generating the ERROR 2115 * report as specified, an ABORT will be triggered 2116 * to the peer and the association won't be 2117 * established. 2118 */ 2119 retval = SCTP_IERROR_NOMEM; 2120 } 2121 break; 2122 default: 2123 break; 2124 } 2125 2126 return retval; 2127 } 2128 2129 /* Verify variable length parameters 2130 * Return values: 2131 * SCTP_IERROR_ABORT - trigger an ABORT 2132 * SCTP_IERROR_NOMEM - out of memory (abort) 2133 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2134 * SCTP_IERROR_NO_ERROR - continue with the chunk 2135 */ 2136 static enum sctp_ierror sctp_verify_param(struct net *net, 2137 const struct sctp_endpoint *ep, 2138 const struct sctp_association *asoc, 2139 union sctp_params param, 2140 enum sctp_cid cid, 2141 struct sctp_chunk *chunk, 2142 struct sctp_chunk **err_chunk) 2143 { 2144 struct sctp_hmac_algo_param *hmacs; 2145 int retval = SCTP_IERROR_NO_ERROR; 2146 __u16 n_elt, id = 0; 2147 int i; 2148 2149 /* FIXME - This routine is not looking at each parameter per the 2150 * chunk type, i.e., unrecognized parameters should be further 2151 * identified based on the chunk id. 2152 */ 2153 2154 switch (param.p->type) { 2155 case SCTP_PARAM_IPV4_ADDRESS: 2156 case SCTP_PARAM_IPV6_ADDRESS: 2157 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2158 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2159 case SCTP_PARAM_STATE_COOKIE: 2160 case SCTP_PARAM_HEARTBEAT_INFO: 2161 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2162 case SCTP_PARAM_ECN_CAPABLE: 2163 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2164 break; 2165 2166 case SCTP_PARAM_SUPPORTED_EXT: 2167 if (!sctp_verify_ext_param(net, param)) 2168 return SCTP_IERROR_ABORT; 2169 break; 2170 2171 case SCTP_PARAM_SET_PRIMARY: 2172 if (net->sctp.addip_enable) 2173 break; 2174 goto fallthrough; 2175 2176 case SCTP_PARAM_HOST_NAME_ADDRESS: 2177 /* Tell the peer, we won't support this param. */ 2178 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2179 retval = SCTP_IERROR_ABORT; 2180 break; 2181 2182 case SCTP_PARAM_FWD_TSN_SUPPORT: 2183 if (ep->prsctp_enable) 2184 break; 2185 goto fallthrough; 2186 2187 case SCTP_PARAM_RANDOM: 2188 if (!ep->auth_enable) 2189 goto fallthrough; 2190 2191 /* SCTP-AUTH: Secion 6.1 2192 * If the random number is not 32 byte long the association 2193 * MUST be aborted. The ABORT chunk SHOULD contain the error 2194 * cause 'Protocol Violation'. 2195 */ 2196 if (SCTP_AUTH_RANDOM_LENGTH != 2197 ntohs(param.p->length) - sizeof(struct sctp_paramhdr)) { 2198 sctp_process_inv_paramlength(asoc, param.p, 2199 chunk, err_chunk); 2200 retval = SCTP_IERROR_ABORT; 2201 } 2202 break; 2203 2204 case SCTP_PARAM_CHUNKS: 2205 if (!ep->auth_enable) 2206 goto fallthrough; 2207 2208 /* SCTP-AUTH: Section 3.2 2209 * The CHUNKS parameter MUST be included once in the INIT or 2210 * INIT-ACK chunk if the sender wants to receive authenticated 2211 * chunks. Its maximum length is 260 bytes. 2212 */ 2213 if (260 < ntohs(param.p->length)) { 2214 sctp_process_inv_paramlength(asoc, param.p, 2215 chunk, err_chunk); 2216 retval = SCTP_IERROR_ABORT; 2217 } 2218 break; 2219 2220 case SCTP_PARAM_HMAC_ALGO: 2221 if (!ep->auth_enable) 2222 goto fallthrough; 2223 2224 hmacs = (struct sctp_hmac_algo_param *)param.p; 2225 n_elt = (ntohs(param.p->length) - 2226 sizeof(struct sctp_paramhdr)) >> 1; 2227 2228 /* SCTP-AUTH: Section 6.1 2229 * The HMAC algorithm based on SHA-1 MUST be supported and 2230 * included in the HMAC-ALGO parameter. 2231 */ 2232 for (i = 0; i < n_elt; i++) { 2233 id = ntohs(hmacs->hmac_ids[i]); 2234 2235 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2236 break; 2237 } 2238 2239 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2240 sctp_process_inv_paramlength(asoc, param.p, chunk, 2241 err_chunk); 2242 retval = SCTP_IERROR_ABORT; 2243 } 2244 break; 2245 fallthrough: 2246 default: 2247 pr_debug("%s: unrecognized param:%d for chunk:%d\n", 2248 __func__, ntohs(param.p->type), cid); 2249 2250 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2251 break; 2252 } 2253 return retval; 2254 } 2255 2256 /* Verify the INIT packet before we process it. */ 2257 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 2258 const struct sctp_association *asoc, enum sctp_cid cid, 2259 struct sctp_init_chunk *peer_init, 2260 struct sctp_chunk *chunk, struct sctp_chunk **errp) 2261 { 2262 union sctp_params param; 2263 bool has_cookie = false; 2264 int result; 2265 2266 /* Check for missing mandatory parameters. Note: Initial TSN is 2267 * also mandatory, but is not checked here since the valid range 2268 * is 0..2**32-1. RFC4960, section 3.3.3. 2269 */ 2270 if (peer_init->init_hdr.num_outbound_streams == 0 || 2271 peer_init->init_hdr.num_inbound_streams == 0 || 2272 peer_init->init_hdr.init_tag == 0 || 2273 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) 2274 return sctp_process_inv_mandatory(asoc, chunk, errp); 2275 2276 sctp_walk_params(param, peer_init, init_hdr.params) { 2277 if (param.p->type == SCTP_PARAM_STATE_COOKIE) 2278 has_cookie = true; 2279 } 2280 2281 /* There is a possibility that a parameter length was bad and 2282 * in that case we would have stoped walking the parameters. 2283 * The current param.p would point at the bad one. 2284 * Current consensus on the mailing list is to generate a PROTOCOL 2285 * VIOLATION error. We build the ERROR chunk here and let the normal 2286 * error handling code build and send the packet. 2287 */ 2288 if (param.v != (void *)chunk->chunk_end) 2289 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2290 2291 /* The only missing mandatory param possible today is 2292 * the state cookie for an INIT-ACK chunk. 2293 */ 2294 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2295 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2296 chunk, errp); 2297 2298 /* Verify all the variable length parameters */ 2299 sctp_walk_params(param, peer_init, init_hdr.params) { 2300 result = sctp_verify_param(net, ep, asoc, param, cid, 2301 chunk, errp); 2302 switch (result) { 2303 case SCTP_IERROR_ABORT: 2304 case SCTP_IERROR_NOMEM: 2305 return 0; 2306 case SCTP_IERROR_ERROR: 2307 return 1; 2308 case SCTP_IERROR_NO_ERROR: 2309 default: 2310 break; 2311 } 2312 2313 } /* for (loop through all parameters) */ 2314 2315 return 1; 2316 } 2317 2318 /* Unpack the parameters in an INIT packet into an association. 2319 * Returns 0 on failure, else success. 2320 * FIXME: This is an association method. 2321 */ 2322 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2323 const union sctp_addr *peer_addr, 2324 struct sctp_init_chunk *peer_init, gfp_t gfp) 2325 { 2326 struct net *net = sock_net(asoc->base.sk); 2327 struct sctp_transport *transport; 2328 struct list_head *pos, *temp; 2329 union sctp_params param; 2330 union sctp_addr addr; 2331 struct sctp_af *af; 2332 int src_match = 0; 2333 char *cookie; 2334 2335 /* We must include the address that the INIT packet came from. 2336 * This is the only address that matters for an INIT packet. 2337 * When processing a COOKIE ECHO, we retrieve the from address 2338 * of the INIT from the cookie. 2339 */ 2340 2341 /* This implementation defaults to making the first transport 2342 * added as the primary transport. The source address seems to 2343 * be a a better choice than any of the embedded addresses. 2344 */ 2345 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2346 goto nomem; 2347 2348 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2349 src_match = 1; 2350 2351 /* Process the initialization parameters. */ 2352 sctp_walk_params(param, peer_init, init_hdr.params) { 2353 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2354 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2355 af = sctp_get_af_specific(param_type2af(param.p->type)); 2356 af->from_addr_param(&addr, param.addr, 2357 chunk->sctp_hdr->source, 0); 2358 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2359 src_match = 1; 2360 } 2361 2362 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2363 goto clean_up; 2364 } 2365 2366 /* source address of chunk may not match any valid address */ 2367 if (!src_match) 2368 goto clean_up; 2369 2370 /* AUTH: After processing the parameters, make sure that we 2371 * have all the required info to potentially do authentications. 2372 */ 2373 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2374 !asoc->peer.peer_hmacs)) 2375 asoc->peer.auth_capable = 0; 2376 2377 /* In a non-backward compatible mode, if the peer claims 2378 * support for ADD-IP but not AUTH, the ADD-IP spec states 2379 * that we MUST ABORT the association. Section 6. The section 2380 * also give us an option to silently ignore the packet, which 2381 * is what we'll do here. 2382 */ 2383 if (!net->sctp.addip_noauth && 2384 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2385 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2386 SCTP_PARAM_DEL_IP | 2387 SCTP_PARAM_SET_PRIMARY); 2388 asoc->peer.asconf_capable = 0; 2389 goto clean_up; 2390 } 2391 2392 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2393 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2394 transport = list_entry(pos, struct sctp_transport, transports); 2395 if (transport->state == SCTP_UNKNOWN) { 2396 sctp_assoc_rm_peer(asoc, transport); 2397 } 2398 } 2399 2400 /* The fixed INIT headers are always in network byte 2401 * order. 2402 */ 2403 asoc->peer.i.init_tag = 2404 ntohl(peer_init->init_hdr.init_tag); 2405 asoc->peer.i.a_rwnd = 2406 ntohl(peer_init->init_hdr.a_rwnd); 2407 asoc->peer.i.num_outbound_streams = 2408 ntohs(peer_init->init_hdr.num_outbound_streams); 2409 asoc->peer.i.num_inbound_streams = 2410 ntohs(peer_init->init_hdr.num_inbound_streams); 2411 asoc->peer.i.initial_tsn = 2412 ntohl(peer_init->init_hdr.initial_tsn); 2413 2414 asoc->strreset_inseq = asoc->peer.i.initial_tsn; 2415 2416 /* Apply the upper bounds for output streams based on peer's 2417 * number of inbound streams. 2418 */ 2419 if (asoc->c.sinit_num_ostreams > 2420 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2421 asoc->c.sinit_num_ostreams = 2422 ntohs(peer_init->init_hdr.num_inbound_streams); 2423 } 2424 2425 if (asoc->c.sinit_max_instreams > 2426 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2427 asoc->c.sinit_max_instreams = 2428 ntohs(peer_init->init_hdr.num_outbound_streams); 2429 } 2430 2431 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2432 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2433 2434 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2435 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2436 2437 /* Copy cookie in case we need to resend COOKIE-ECHO. */ 2438 cookie = asoc->peer.cookie; 2439 if (cookie) { 2440 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp); 2441 if (!asoc->peer.cookie) 2442 goto clean_up; 2443 } 2444 2445 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2446 * high (for example, implementations MAY use the size of the receiver 2447 * advertised window). 2448 */ 2449 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2450 transports) { 2451 transport->ssthresh = asoc->peer.i.a_rwnd; 2452 } 2453 2454 /* Set up the TSN tracking pieces. */ 2455 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2456 asoc->peer.i.initial_tsn, gfp)) 2457 goto clean_up; 2458 2459 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2460 * 2461 * The stream sequence number in all the streams shall start 2462 * from 0 when the association is established. Also, when the 2463 * stream sequence number reaches the value 65535 the next 2464 * stream sequence number shall be set to 0. 2465 */ 2466 2467 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams, 2468 asoc->c.sinit_max_instreams, gfp)) 2469 goto clean_up; 2470 2471 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp)) 2472 goto clean_up; 2473 2474 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2475 * 2476 * When an endpoint has an ASCONF signaled change to be sent to the 2477 * remote endpoint it should do the following: 2478 * ... 2479 * A2) A serial number should be assigned to the Chunk. The serial 2480 * number should be a monotonically increasing number. All serial 2481 * numbers are defined to be initialized at the start of the 2482 * association to the same value as the Initial TSN. 2483 */ 2484 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2485 return 1; 2486 2487 clean_up: 2488 /* Release the transport structures. */ 2489 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2490 transport = list_entry(pos, struct sctp_transport, transports); 2491 if (transport->state != SCTP_ACTIVE) 2492 sctp_assoc_rm_peer(asoc, transport); 2493 } 2494 2495 nomem: 2496 return 0; 2497 } 2498 2499 2500 /* Update asoc with the option described in param. 2501 * 2502 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2503 * 2504 * asoc is the association to update. 2505 * param is the variable length parameter to use for update. 2506 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2507 * If the current packet is an INIT we want to minimize the amount of 2508 * work we do. In particular, we should not build transport 2509 * structures for the addresses. 2510 */ 2511 static int sctp_process_param(struct sctp_association *asoc, 2512 union sctp_params param, 2513 const union sctp_addr *peer_addr, 2514 gfp_t gfp) 2515 { 2516 struct net *net = sock_net(asoc->base.sk); 2517 struct sctp_endpoint *ep = asoc->ep; 2518 union sctp_addr_param *addr_param; 2519 struct sctp_transport *t; 2520 enum sctp_scope scope; 2521 union sctp_addr addr; 2522 struct sctp_af *af; 2523 int retval = 1, i; 2524 u32 stale; 2525 __u16 sat; 2526 2527 /* We maintain all INIT parameters in network byte order all the 2528 * time. This allows us to not worry about whether the parameters 2529 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2530 */ 2531 switch (param.p->type) { 2532 case SCTP_PARAM_IPV6_ADDRESS: 2533 if (PF_INET6 != asoc->base.sk->sk_family) 2534 break; 2535 goto do_addr_param; 2536 2537 case SCTP_PARAM_IPV4_ADDRESS: 2538 /* v4 addresses are not allowed on v6-only socket */ 2539 if (ipv6_only_sock(asoc->base.sk)) 2540 break; 2541 do_addr_param: 2542 af = sctp_get_af_specific(param_type2af(param.p->type)); 2543 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); 2544 scope = sctp_scope(peer_addr); 2545 if (sctp_in_scope(net, &addr, scope)) 2546 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2547 return 0; 2548 break; 2549 2550 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2551 if (!net->sctp.cookie_preserve_enable) 2552 break; 2553 2554 stale = ntohl(param.life->lifespan_increment); 2555 2556 /* Suggested Cookie Life span increment's unit is msec, 2557 * (1/1000sec). 2558 */ 2559 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale); 2560 break; 2561 2562 case SCTP_PARAM_HOST_NAME_ADDRESS: 2563 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__); 2564 break; 2565 2566 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2567 /* Turn off the default values first so we'll know which 2568 * ones are really set by the peer. 2569 */ 2570 asoc->peer.ipv4_address = 0; 2571 asoc->peer.ipv6_address = 0; 2572 2573 /* Assume that peer supports the address family 2574 * by which it sends a packet. 2575 */ 2576 if (peer_addr->sa.sa_family == AF_INET6) 2577 asoc->peer.ipv6_address = 1; 2578 else if (peer_addr->sa.sa_family == AF_INET) 2579 asoc->peer.ipv4_address = 1; 2580 2581 /* Cycle through address types; avoid divide by 0. */ 2582 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2583 if (sat) 2584 sat /= sizeof(__u16); 2585 2586 for (i = 0; i < sat; ++i) { 2587 switch (param.sat->types[i]) { 2588 case SCTP_PARAM_IPV4_ADDRESS: 2589 asoc->peer.ipv4_address = 1; 2590 break; 2591 2592 case SCTP_PARAM_IPV6_ADDRESS: 2593 if (PF_INET6 == asoc->base.sk->sk_family) 2594 asoc->peer.ipv6_address = 1; 2595 break; 2596 2597 case SCTP_PARAM_HOST_NAME_ADDRESS: 2598 asoc->peer.hostname_address = 1; 2599 break; 2600 2601 default: /* Just ignore anything else. */ 2602 break; 2603 } 2604 } 2605 break; 2606 2607 case SCTP_PARAM_STATE_COOKIE: 2608 asoc->peer.cookie_len = 2609 ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2610 asoc->peer.cookie = param.cookie->body; 2611 break; 2612 2613 case SCTP_PARAM_HEARTBEAT_INFO: 2614 /* Would be odd to receive, but it causes no problems. */ 2615 break; 2616 2617 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2618 /* Rejected during verify stage. */ 2619 break; 2620 2621 case SCTP_PARAM_ECN_CAPABLE: 2622 asoc->peer.ecn_capable = 1; 2623 break; 2624 2625 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2626 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2627 break; 2628 2629 case SCTP_PARAM_SET_PRIMARY: 2630 if (!net->sctp.addip_enable) 2631 goto fall_through; 2632 2633 addr_param = param.v + sizeof(struct sctp_addip_param); 2634 2635 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 2636 if (af == NULL) 2637 break; 2638 2639 af->from_addr_param(&addr, addr_param, 2640 htons(asoc->peer.port), 0); 2641 2642 /* if the address is invalid, we can't process it. 2643 * XXX: see spec for what to do. 2644 */ 2645 if (!af->addr_valid(&addr, NULL, NULL)) 2646 break; 2647 2648 t = sctp_assoc_lookup_paddr(asoc, &addr); 2649 if (!t) 2650 break; 2651 2652 sctp_assoc_set_primary(asoc, t); 2653 break; 2654 2655 case SCTP_PARAM_SUPPORTED_EXT: 2656 sctp_process_ext_param(asoc, param); 2657 break; 2658 2659 case SCTP_PARAM_FWD_TSN_SUPPORT: 2660 if (asoc->prsctp_enable) { 2661 asoc->peer.prsctp_capable = 1; 2662 break; 2663 } 2664 /* Fall Through */ 2665 goto fall_through; 2666 2667 case SCTP_PARAM_RANDOM: 2668 if (!ep->auth_enable) 2669 goto fall_through; 2670 2671 /* Save peer's random parameter */ 2672 asoc->peer.peer_random = kmemdup(param.p, 2673 ntohs(param.p->length), gfp); 2674 if (!asoc->peer.peer_random) { 2675 retval = 0; 2676 break; 2677 } 2678 break; 2679 2680 case SCTP_PARAM_HMAC_ALGO: 2681 if (!ep->auth_enable) 2682 goto fall_through; 2683 2684 /* Save peer's HMAC list */ 2685 asoc->peer.peer_hmacs = kmemdup(param.p, 2686 ntohs(param.p->length), gfp); 2687 if (!asoc->peer.peer_hmacs) { 2688 retval = 0; 2689 break; 2690 } 2691 2692 /* Set the default HMAC the peer requested*/ 2693 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2694 break; 2695 2696 case SCTP_PARAM_CHUNKS: 2697 if (!ep->auth_enable) 2698 goto fall_through; 2699 2700 asoc->peer.peer_chunks = kmemdup(param.p, 2701 ntohs(param.p->length), gfp); 2702 if (!asoc->peer.peer_chunks) 2703 retval = 0; 2704 break; 2705 fall_through: 2706 default: 2707 /* Any unrecognized parameters should have been caught 2708 * and handled by sctp_verify_param() which should be 2709 * called prior to this routine. Simply log the error 2710 * here. 2711 */ 2712 pr_debug("%s: ignoring param:%d for association:%p.\n", 2713 __func__, ntohs(param.p->type), asoc); 2714 break; 2715 } 2716 2717 return retval; 2718 } 2719 2720 /* Select a new verification tag. */ 2721 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2722 { 2723 /* I believe that this random number generator complies with RFC1750. 2724 * A tag of 0 is reserved for special cases (e.g. INIT). 2725 */ 2726 __u32 x; 2727 2728 do { 2729 get_random_bytes(&x, sizeof(__u32)); 2730 } while (x == 0); 2731 2732 return x; 2733 } 2734 2735 /* Select an initial TSN to send during startup. */ 2736 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2737 { 2738 __u32 retval; 2739 2740 get_random_bytes(&retval, sizeof(__u32)); 2741 return retval; 2742 } 2743 2744 /* 2745 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2746 * 0 1 2 3 2747 * 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 2748 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2749 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2750 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2751 * | Serial Number | 2752 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2753 * | Address Parameter | 2754 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2755 * | ASCONF Parameter #1 | 2756 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2757 * \ \ 2758 * / .... / 2759 * \ \ 2760 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2761 * | ASCONF Parameter #N | 2762 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2763 * 2764 * Address Parameter and other parameter will not be wrapped in this function 2765 */ 2766 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2767 union sctp_addr *addr, 2768 int vparam_len) 2769 { 2770 struct sctp_addiphdr asconf; 2771 struct sctp_chunk *retval; 2772 int length = sizeof(asconf) + vparam_len; 2773 union sctp_addr_param addrparam; 2774 int addrlen; 2775 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2776 2777 addrlen = af->to_addr_param(addr, &addrparam); 2778 if (!addrlen) 2779 return NULL; 2780 length += addrlen; 2781 2782 /* Create the chunk. */ 2783 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length, 2784 GFP_ATOMIC); 2785 if (!retval) 2786 return NULL; 2787 2788 asconf.serial = htonl(asoc->addip_serial++); 2789 2790 retval->subh.addip_hdr = 2791 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2792 retval->param_hdr.v = 2793 sctp_addto_chunk(retval, addrlen, &addrparam); 2794 2795 return retval; 2796 } 2797 2798 /* ADDIP 2799 * 3.2.1 Add IP Address 2800 * 0 1 2 3 2801 * 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 2802 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2803 * | Type = 0xC001 | Length = Variable | 2804 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2805 * | ASCONF-Request Correlation ID | 2806 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2807 * | Address Parameter | 2808 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2809 * 2810 * 3.2.2 Delete IP Address 2811 * 0 1 2 3 2812 * 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 2813 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2814 * | Type = 0xC002 | Length = Variable | 2815 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2816 * | ASCONF-Request Correlation ID | 2817 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2818 * | Address Parameter | 2819 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2820 * 2821 */ 2822 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2823 union sctp_addr *laddr, 2824 struct sockaddr *addrs, 2825 int addrcnt, __be16 flags) 2826 { 2827 union sctp_addr_param addr_param; 2828 struct sctp_addip_param param; 2829 int paramlen = sizeof(param); 2830 struct sctp_chunk *retval; 2831 int addr_param_len = 0; 2832 union sctp_addr *addr; 2833 int totallen = 0, i; 2834 int del_pickup = 0; 2835 struct sctp_af *af; 2836 void *addr_buf; 2837 2838 /* Get total length of all the address parameters. */ 2839 addr_buf = addrs; 2840 for (i = 0; i < addrcnt; i++) { 2841 addr = addr_buf; 2842 af = sctp_get_af_specific(addr->v4.sin_family); 2843 addr_param_len = af->to_addr_param(addr, &addr_param); 2844 2845 totallen += paramlen; 2846 totallen += addr_param_len; 2847 2848 addr_buf += af->sockaddr_len; 2849 if (asoc->asconf_addr_del_pending && !del_pickup) { 2850 /* reuse the parameter length from the same scope one */ 2851 totallen += paramlen; 2852 totallen += addr_param_len; 2853 del_pickup = 1; 2854 2855 pr_debug("%s: picked same-scope del_pending addr, " 2856 "totallen for all addresses is %d\n", 2857 __func__, totallen); 2858 } 2859 } 2860 2861 /* Create an asconf chunk with the required length. */ 2862 retval = sctp_make_asconf(asoc, laddr, totallen); 2863 if (!retval) 2864 return NULL; 2865 2866 /* Add the address parameters to the asconf chunk. */ 2867 addr_buf = addrs; 2868 for (i = 0; i < addrcnt; i++) { 2869 addr = addr_buf; 2870 af = sctp_get_af_specific(addr->v4.sin_family); 2871 addr_param_len = af->to_addr_param(addr, &addr_param); 2872 param.param_hdr.type = flags; 2873 param.param_hdr.length = htons(paramlen + addr_param_len); 2874 param.crr_id = htonl(i); 2875 2876 sctp_addto_chunk(retval, paramlen, ¶m); 2877 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2878 2879 addr_buf += af->sockaddr_len; 2880 } 2881 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2882 addr = asoc->asconf_addr_del_pending; 2883 af = sctp_get_af_specific(addr->v4.sin_family); 2884 addr_param_len = af->to_addr_param(addr, &addr_param); 2885 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2886 param.param_hdr.length = htons(paramlen + addr_param_len); 2887 param.crr_id = htonl(i); 2888 2889 sctp_addto_chunk(retval, paramlen, ¶m); 2890 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2891 } 2892 return retval; 2893 } 2894 2895 /* ADDIP 2896 * 3.2.4 Set Primary IP Address 2897 * 0 1 2 3 2898 * 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 2899 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2900 * | Type =0xC004 | Length = Variable | 2901 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2902 * | ASCONF-Request Correlation ID | 2903 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2904 * | Address Parameter | 2905 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2906 * 2907 * Create an ASCONF chunk with Set Primary IP address parameter. 2908 */ 2909 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2910 union sctp_addr *addr) 2911 { 2912 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2913 union sctp_addr_param addrparam; 2914 struct sctp_addip_param param; 2915 struct sctp_chunk *retval; 2916 int len = sizeof(param); 2917 int addrlen; 2918 2919 addrlen = af->to_addr_param(addr, &addrparam); 2920 if (!addrlen) 2921 return NULL; 2922 len += addrlen; 2923 2924 /* Create the chunk and make asconf header. */ 2925 retval = sctp_make_asconf(asoc, addr, len); 2926 if (!retval) 2927 return NULL; 2928 2929 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2930 param.param_hdr.length = htons(len); 2931 param.crr_id = 0; 2932 2933 sctp_addto_chunk(retval, sizeof(param), ¶m); 2934 sctp_addto_chunk(retval, addrlen, &addrparam); 2935 2936 return retval; 2937 } 2938 2939 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2940 * 0 1 2 3 2941 * 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 2942 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2943 * | Type = 0x80 | Chunk Flags | Chunk Length | 2944 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2945 * | Serial Number | 2946 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2947 * | ASCONF Parameter Response#1 | 2948 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2949 * \ \ 2950 * / .... / 2951 * \ \ 2952 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2953 * | ASCONF Parameter Response#N | 2954 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2955 * 2956 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2957 */ 2958 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2959 __u32 serial, int vparam_len) 2960 { 2961 struct sctp_addiphdr asconf; 2962 struct sctp_chunk *retval; 2963 int length = sizeof(asconf) + vparam_len; 2964 2965 /* Create the chunk. */ 2966 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length, 2967 GFP_ATOMIC); 2968 if (!retval) 2969 return NULL; 2970 2971 asconf.serial = htonl(serial); 2972 2973 retval->subh.addip_hdr = 2974 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2975 2976 return retval; 2977 } 2978 2979 /* Add response parameters to an ASCONF_ACK chunk. */ 2980 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2981 __be16 err_code, 2982 struct sctp_addip_param *asconf_param) 2983 { 2984 struct sctp_addip_param ack_param; 2985 struct sctp_errhdr err_param; 2986 int asconf_param_len = 0; 2987 int err_param_len = 0; 2988 __be16 response_type; 2989 2990 if (SCTP_ERROR_NO_ERROR == err_code) { 2991 response_type = SCTP_PARAM_SUCCESS_REPORT; 2992 } else { 2993 response_type = SCTP_PARAM_ERR_CAUSE; 2994 err_param_len = sizeof(err_param); 2995 if (asconf_param) 2996 asconf_param_len = 2997 ntohs(asconf_param->param_hdr.length); 2998 } 2999 3000 /* Add Success Indication or Error Cause Indication parameter. */ 3001 ack_param.param_hdr.type = response_type; 3002 ack_param.param_hdr.length = htons(sizeof(ack_param) + 3003 err_param_len + 3004 asconf_param_len); 3005 ack_param.crr_id = crr_id; 3006 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 3007 3008 if (SCTP_ERROR_NO_ERROR == err_code) 3009 return; 3010 3011 /* Add Error Cause parameter. */ 3012 err_param.cause = err_code; 3013 err_param.length = htons(err_param_len + asconf_param_len); 3014 sctp_addto_chunk(chunk, err_param_len, &err_param); 3015 3016 /* Add the failed TLV copied from ASCONF chunk. */ 3017 if (asconf_param) 3018 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 3019 } 3020 3021 /* Process a asconf parameter. */ 3022 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 3023 struct sctp_chunk *asconf, 3024 struct sctp_addip_param *asconf_param) 3025 { 3026 union sctp_addr_param *addr_param; 3027 struct sctp_transport *peer; 3028 union sctp_addr addr; 3029 struct sctp_af *af; 3030 3031 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3032 3033 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 3034 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 3035 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 3036 return SCTP_ERROR_UNKNOWN_PARAM; 3037 3038 switch (addr_param->p.type) { 3039 case SCTP_PARAM_IPV6_ADDRESS: 3040 if (!asoc->peer.ipv6_address) 3041 return SCTP_ERROR_DNS_FAILED; 3042 break; 3043 case SCTP_PARAM_IPV4_ADDRESS: 3044 if (!asoc->peer.ipv4_address) 3045 return SCTP_ERROR_DNS_FAILED; 3046 break; 3047 default: 3048 return SCTP_ERROR_DNS_FAILED; 3049 } 3050 3051 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3052 if (unlikely(!af)) 3053 return SCTP_ERROR_DNS_FAILED; 3054 3055 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); 3056 3057 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3058 * or multicast address. 3059 * (note: wildcard is permitted and requires special handling so 3060 * make sure we check for that) 3061 */ 3062 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3063 return SCTP_ERROR_DNS_FAILED; 3064 3065 switch (asconf_param->param_hdr.type) { 3066 case SCTP_PARAM_ADD_IP: 3067 /* Section 4.2.1: 3068 * If the address 0.0.0.0 or ::0 is provided, the source 3069 * address of the packet MUST be added. 3070 */ 3071 if (af->is_any(&addr)) 3072 memcpy(&addr, &asconf->source, sizeof(addr)); 3073 3074 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3075 * request and does not have the local resources to add this 3076 * new address to the association, it MUST return an Error 3077 * Cause TLV set to the new error code 'Operation Refused 3078 * Due to Resource Shortage'. 3079 */ 3080 3081 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3082 if (!peer) 3083 return SCTP_ERROR_RSRC_LOW; 3084 3085 /* Start the heartbeat timer. */ 3086 sctp_transport_reset_hb_timer(peer); 3087 asoc->new_transport = peer; 3088 break; 3089 case SCTP_PARAM_DEL_IP: 3090 /* ADDIP 4.3 D7) If a request is received to delete the 3091 * last remaining IP address of a peer endpoint, the receiver 3092 * MUST send an Error Cause TLV with the error cause set to the 3093 * new error code 'Request to Delete Last Remaining IP Address'. 3094 */ 3095 if (asoc->peer.transport_count == 1) 3096 return SCTP_ERROR_DEL_LAST_IP; 3097 3098 /* ADDIP 4.3 D8) If a request is received to delete an IP 3099 * address which is also the source address of the IP packet 3100 * which contained the ASCONF chunk, the receiver MUST reject 3101 * this request. To reject the request the receiver MUST send 3102 * an Error Cause TLV set to the new error code 'Request to 3103 * Delete Source IP Address' 3104 */ 3105 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3106 return SCTP_ERROR_DEL_SRC_IP; 3107 3108 /* Section 4.2.2 3109 * If the address 0.0.0.0 or ::0 is provided, all 3110 * addresses of the peer except the source address of the 3111 * packet MUST be deleted. 3112 */ 3113 if (af->is_any(&addr)) { 3114 sctp_assoc_set_primary(asoc, asconf->transport); 3115 sctp_assoc_del_nonprimary_peers(asoc, 3116 asconf->transport); 3117 return SCTP_ERROR_NO_ERROR; 3118 } 3119 3120 /* If the address is not part of the association, the 3121 * ASCONF-ACK with Error Cause Indication Parameter 3122 * which including cause of Unresolvable Address should 3123 * be sent. 3124 */ 3125 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3126 if (!peer) 3127 return SCTP_ERROR_DNS_FAILED; 3128 3129 sctp_assoc_rm_peer(asoc, peer); 3130 break; 3131 case SCTP_PARAM_SET_PRIMARY: 3132 /* ADDIP Section 4.2.4 3133 * If the address 0.0.0.0 or ::0 is provided, the receiver 3134 * MAY mark the source address of the packet as its 3135 * primary. 3136 */ 3137 if (af->is_any(&addr)) 3138 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr)); 3139 3140 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3141 if (!peer) 3142 return SCTP_ERROR_DNS_FAILED; 3143 3144 sctp_assoc_set_primary(asoc, peer); 3145 break; 3146 } 3147 3148 return SCTP_ERROR_NO_ERROR; 3149 } 3150 3151 /* Verify the ASCONF packet before we process it. */ 3152 bool sctp_verify_asconf(const struct sctp_association *asoc, 3153 struct sctp_chunk *chunk, bool addr_param_needed, 3154 struct sctp_paramhdr **errp) 3155 { 3156 struct sctp_addip_chunk *addip; 3157 bool addr_param_seen = false; 3158 union sctp_params param; 3159 3160 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr; 3161 sctp_walk_params(param, addip, addip_hdr.params) { 3162 size_t length = ntohs(param.p->length); 3163 3164 *errp = param.p; 3165 switch (param.p->type) { 3166 case SCTP_PARAM_ERR_CAUSE: 3167 break; 3168 case SCTP_PARAM_IPV4_ADDRESS: 3169 if (length != sizeof(struct sctp_ipv4addr_param)) 3170 return false; 3171 /* ensure there is only one addr param and it's in the 3172 * beginning of addip_hdr params, or we reject it. 3173 */ 3174 if (param.v != addip->addip_hdr.params) 3175 return false; 3176 addr_param_seen = true; 3177 break; 3178 case SCTP_PARAM_IPV6_ADDRESS: 3179 if (length != sizeof(struct sctp_ipv6addr_param)) 3180 return false; 3181 if (param.v != addip->addip_hdr.params) 3182 return false; 3183 addr_param_seen = true; 3184 break; 3185 case SCTP_PARAM_ADD_IP: 3186 case SCTP_PARAM_DEL_IP: 3187 case SCTP_PARAM_SET_PRIMARY: 3188 /* In ASCONF chunks, these need to be first. */ 3189 if (addr_param_needed && !addr_param_seen) 3190 return false; 3191 length = ntohs(param.addip->param_hdr.length); 3192 if (length < sizeof(struct sctp_addip_param) + 3193 sizeof(**errp)) 3194 return false; 3195 break; 3196 case SCTP_PARAM_SUCCESS_REPORT: 3197 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3198 if (length != sizeof(struct sctp_addip_param)) 3199 return false; 3200 break; 3201 default: 3202 /* This is unkown to us, reject! */ 3203 return false; 3204 } 3205 } 3206 3207 /* Remaining sanity checks. */ 3208 if (addr_param_needed && !addr_param_seen) 3209 return false; 3210 if (!addr_param_needed && addr_param_seen) 3211 return false; 3212 if (param.v != chunk->chunk_end) 3213 return false; 3214 3215 return true; 3216 } 3217 3218 /* Process an incoming ASCONF chunk with the next expected serial no. and 3219 * return an ASCONF_ACK chunk to be sent in response. 3220 */ 3221 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3222 struct sctp_chunk *asconf) 3223 { 3224 union sctp_addr_param *addr_param; 3225 struct sctp_addip_chunk *addip; 3226 struct sctp_chunk *asconf_ack; 3227 bool all_param_pass = true; 3228 struct sctp_addiphdr *hdr; 3229 int length = 0, chunk_len; 3230 union sctp_params param; 3231 __be16 err_code; 3232 __u32 serial; 3233 3234 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr; 3235 chunk_len = ntohs(asconf->chunk_hdr->length) - 3236 sizeof(struct sctp_chunkhdr); 3237 hdr = (struct sctp_addiphdr *)asconf->skb->data; 3238 serial = ntohl(hdr->serial); 3239 3240 /* Skip the addiphdr and store a pointer to address parameter. */ 3241 length = sizeof(*hdr); 3242 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3243 chunk_len -= length; 3244 3245 /* Skip the address parameter and store a pointer to the first 3246 * asconf parameter. 3247 */ 3248 length = ntohs(addr_param->p.length); 3249 chunk_len -= length; 3250 3251 /* create an ASCONF_ACK chunk. 3252 * Based on the definitions of parameters, we know that the size of 3253 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3254 * parameters. 3255 */ 3256 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3257 if (!asconf_ack) 3258 goto done; 3259 3260 /* Process the TLVs contained within the ASCONF chunk. */ 3261 sctp_walk_params(param, addip, addip_hdr.params) { 3262 /* Skip preceeding address parameters. */ 3263 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 3264 param.p->type == SCTP_PARAM_IPV6_ADDRESS) 3265 continue; 3266 3267 err_code = sctp_process_asconf_param(asoc, asconf, 3268 param.addip); 3269 /* ADDIP 4.1 A7) 3270 * If an error response is received for a TLV parameter, 3271 * all TLVs with no response before the failed TLV are 3272 * considered successful if not reported. All TLVs after 3273 * the failed response are considered unsuccessful unless 3274 * a specific success indication is present for the parameter. 3275 */ 3276 if (err_code != SCTP_ERROR_NO_ERROR) 3277 all_param_pass = false; 3278 if (!all_param_pass) 3279 sctp_add_asconf_response(asconf_ack, param.addip->crr_id, 3280 err_code, param.addip); 3281 3282 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3283 * an IP address sends an 'Out of Resource' in its response, it 3284 * MUST also fail any subsequent add or delete requests bundled 3285 * in the ASCONF. 3286 */ 3287 if (err_code == SCTP_ERROR_RSRC_LOW) 3288 goto done; 3289 } 3290 done: 3291 asoc->peer.addip_serial++; 3292 3293 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3294 * after freeing the reference to old asconf ack if any. 3295 */ 3296 if (asconf_ack) { 3297 sctp_chunk_hold(asconf_ack); 3298 list_add_tail(&asconf_ack->transmitted_list, 3299 &asoc->asconf_ack_list); 3300 } 3301 3302 return asconf_ack; 3303 } 3304 3305 /* Process a asconf parameter that is successfully acked. */ 3306 static void sctp_asconf_param_success(struct sctp_association *asoc, 3307 struct sctp_addip_param *asconf_param) 3308 { 3309 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3310 union sctp_addr_param *addr_param; 3311 struct sctp_sockaddr_entry *saddr; 3312 struct sctp_transport *transport; 3313 union sctp_addr addr; 3314 struct sctp_af *af; 3315 3316 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3317 3318 /* We have checked the packet before, so we do not check again. */ 3319 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3320 af->from_addr_param(&addr, addr_param, htons(bp->port), 0); 3321 3322 switch (asconf_param->param_hdr.type) { 3323 case SCTP_PARAM_ADD_IP: 3324 /* This is always done in BH context with a socket lock 3325 * held, so the list can not change. 3326 */ 3327 local_bh_disable(); 3328 list_for_each_entry(saddr, &bp->address_list, list) { 3329 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3330 saddr->state = SCTP_ADDR_SRC; 3331 } 3332 local_bh_enable(); 3333 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3334 transports) { 3335 sctp_transport_dst_release(transport); 3336 } 3337 break; 3338 case SCTP_PARAM_DEL_IP: 3339 local_bh_disable(); 3340 sctp_del_bind_addr(bp, &addr); 3341 if (asoc->asconf_addr_del_pending != NULL && 3342 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3343 kfree(asoc->asconf_addr_del_pending); 3344 asoc->asconf_addr_del_pending = NULL; 3345 } 3346 local_bh_enable(); 3347 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3348 transports) { 3349 sctp_transport_dst_release(transport); 3350 } 3351 break; 3352 default: 3353 break; 3354 } 3355 } 3356 3357 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3358 * for the given asconf parameter. If there is no response for this parameter, 3359 * return the error code based on the third argument 'no_err'. 3360 * ADDIP 4.1 3361 * A7) If an error response is received for a TLV parameter, all TLVs with no 3362 * response before the failed TLV are considered successful if not reported. 3363 * All TLVs after the failed response are considered unsuccessful unless a 3364 * specific success indication is present for the parameter. 3365 */ 3366 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3367 struct sctp_addip_param *asconf_param, 3368 int no_err) 3369 { 3370 struct sctp_addip_param *asconf_ack_param; 3371 struct sctp_errhdr *err_param; 3372 int asconf_ack_len; 3373 __be16 err_code; 3374 int length; 3375 3376 if (no_err) 3377 err_code = SCTP_ERROR_NO_ERROR; 3378 else 3379 err_code = SCTP_ERROR_REQ_REFUSED; 3380 3381 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3382 sizeof(struct sctp_chunkhdr); 3383 3384 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3385 * the first asconf_ack parameter. 3386 */ 3387 length = sizeof(struct sctp_addiphdr); 3388 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data + 3389 length); 3390 asconf_ack_len -= length; 3391 3392 while (asconf_ack_len > 0) { 3393 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3394 switch (asconf_ack_param->param_hdr.type) { 3395 case SCTP_PARAM_SUCCESS_REPORT: 3396 return SCTP_ERROR_NO_ERROR; 3397 case SCTP_PARAM_ERR_CAUSE: 3398 length = sizeof(*asconf_ack_param); 3399 err_param = (void *)asconf_ack_param + length; 3400 asconf_ack_len -= length; 3401 if (asconf_ack_len > 0) 3402 return err_param->cause; 3403 else 3404 return SCTP_ERROR_INV_PARAM; 3405 break; 3406 default: 3407 return SCTP_ERROR_INV_PARAM; 3408 } 3409 } 3410 3411 length = ntohs(asconf_ack_param->param_hdr.length); 3412 asconf_ack_param = (void *)asconf_ack_param + length; 3413 asconf_ack_len -= length; 3414 } 3415 3416 return err_code; 3417 } 3418 3419 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3420 int sctp_process_asconf_ack(struct sctp_association *asoc, 3421 struct sctp_chunk *asconf_ack) 3422 { 3423 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3424 struct sctp_addip_param *asconf_param; 3425 __be16 err_code = SCTP_ERROR_NO_ERROR; 3426 union sctp_addr_param *addr_param; 3427 int asconf_len = asconf->skb->len; 3428 int all_param_pass = 0; 3429 int length = 0; 3430 int no_err = 1; 3431 int retval = 0; 3432 3433 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3434 * a pointer to address parameter. 3435 */ 3436 length = sizeof(struct sctp_addip_chunk); 3437 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3438 asconf_len -= length; 3439 3440 /* Skip the address parameter in the last asconf sent and store a 3441 * pointer to the first asconf parameter. 3442 */ 3443 length = ntohs(addr_param->p.length); 3444 asconf_param = (void *)addr_param + length; 3445 asconf_len -= length; 3446 3447 /* ADDIP 4.1 3448 * A8) If there is no response(s) to specific TLV parameter(s), and no 3449 * failures are indicated, then all request(s) are considered 3450 * successful. 3451 */ 3452 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr)) 3453 all_param_pass = 1; 3454 3455 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3456 while (asconf_len > 0) { 3457 if (all_param_pass) 3458 err_code = SCTP_ERROR_NO_ERROR; 3459 else { 3460 err_code = sctp_get_asconf_response(asconf_ack, 3461 asconf_param, 3462 no_err); 3463 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3464 no_err = 0; 3465 } 3466 3467 switch (err_code) { 3468 case SCTP_ERROR_NO_ERROR: 3469 sctp_asconf_param_success(asoc, asconf_param); 3470 break; 3471 3472 case SCTP_ERROR_RSRC_LOW: 3473 retval = 1; 3474 break; 3475 3476 case SCTP_ERROR_UNKNOWN_PARAM: 3477 /* Disable sending this type of asconf parameter in 3478 * future. 3479 */ 3480 asoc->peer.addip_disabled_mask |= 3481 asconf_param->param_hdr.type; 3482 break; 3483 3484 case SCTP_ERROR_REQ_REFUSED: 3485 case SCTP_ERROR_DEL_LAST_IP: 3486 case SCTP_ERROR_DEL_SRC_IP: 3487 default: 3488 break; 3489 } 3490 3491 /* Skip the processed asconf parameter and move to the next 3492 * one. 3493 */ 3494 length = ntohs(asconf_param->param_hdr.length); 3495 asconf_param = (void *)asconf_param + length; 3496 asconf_len -= length; 3497 } 3498 3499 if (no_err && asoc->src_out_of_asoc_ok) { 3500 asoc->src_out_of_asoc_ok = 0; 3501 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3502 } 3503 3504 /* Free the cached last sent asconf chunk. */ 3505 list_del_init(&asconf->transmitted_list); 3506 sctp_chunk_free(asconf); 3507 asoc->addip_last_asconf = NULL; 3508 3509 return retval; 3510 } 3511 3512 /* Make a FWD TSN chunk. */ 3513 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3514 __u32 new_cum_tsn, size_t nstreams, 3515 struct sctp_fwdtsn_skip *skiplist) 3516 { 3517 struct sctp_chunk *retval = NULL; 3518 struct sctp_fwdtsn_hdr ftsn_hdr; 3519 struct sctp_fwdtsn_skip skip; 3520 size_t hint; 3521 int i; 3522 3523 hint = (nstreams + 1) * sizeof(__u32); 3524 3525 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC); 3526 3527 if (!retval) 3528 return NULL; 3529 3530 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3531 retval->subh.fwdtsn_hdr = 3532 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3533 3534 for (i = 0; i < nstreams; i++) { 3535 skip.stream = skiplist[i].stream; 3536 skip.ssn = skiplist[i].ssn; 3537 sctp_addto_chunk(retval, sizeof(skip), &skip); 3538 } 3539 3540 return retval; 3541 } 3542 3543 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc, 3544 __u32 new_cum_tsn, size_t nstreams, 3545 struct sctp_ifwdtsn_skip *skiplist) 3546 { 3547 struct sctp_chunk *retval = NULL; 3548 struct sctp_ifwdtsn_hdr ftsn_hdr; 3549 size_t hint; 3550 3551 hint = (nstreams + 1) * sizeof(__u32); 3552 3553 retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint, 3554 GFP_ATOMIC); 3555 if (!retval) 3556 return NULL; 3557 3558 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3559 retval->subh.ifwdtsn_hdr = 3560 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3561 3562 sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist); 3563 3564 return retval; 3565 } 3566 3567 /* RE-CONFIG 3.1 (RE-CONFIG chunk) 3568 * 0 1 2 3 3569 * 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 3570 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3571 * | Type = 130 | Chunk Flags | Chunk Length | 3572 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3573 * \ \ 3574 * / Re-configuration Parameter / 3575 * \ \ 3576 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3577 * \ \ 3578 * / Re-configuration Parameter (optional) / 3579 * \ \ 3580 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3581 */ 3582 static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc, 3583 int length) 3584 { 3585 struct sctp_reconf_chunk *reconf; 3586 struct sctp_chunk *retval; 3587 3588 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length, 3589 GFP_ATOMIC); 3590 if (!retval) 3591 return NULL; 3592 3593 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr; 3594 retval->param_hdr.v = reconf->params; 3595 3596 return retval; 3597 } 3598 3599 /* RE-CONFIG 4.1 (STREAM OUT RESET) 3600 * 0 1 2 3 3601 * 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 3602 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3603 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N | 3604 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3605 * | Re-configuration Request Sequence Number | 3606 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3607 * | Re-configuration Response Sequence Number | 3608 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3609 * | Sender's Last Assigned TSN | 3610 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3611 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3612 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3613 * / ...... / 3614 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3615 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3616 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3617 * 3618 * RE-CONFIG 4.2 (STREAM IN RESET) 3619 * 0 1 2 3 3620 * 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 3621 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3622 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N | 3623 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3624 * | Re-configuration Request Sequence Number | 3625 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3626 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3627 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3628 * / ...... / 3629 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3630 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3631 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3632 */ 3633 struct sctp_chunk *sctp_make_strreset_req( 3634 const struct sctp_association *asoc, 3635 __u16 stream_num, __be16 *stream_list, 3636 bool out, bool in) 3637 { 3638 __u16 stream_len = stream_num * sizeof(__u16); 3639 struct sctp_strreset_outreq outreq; 3640 struct sctp_strreset_inreq inreq; 3641 struct sctp_chunk *retval; 3642 __u16 outlen, inlen; 3643 3644 outlen = (sizeof(outreq) + stream_len) * out; 3645 inlen = (sizeof(inreq) + stream_len) * in; 3646 3647 retval = sctp_make_reconf(asoc, outlen + inlen); 3648 if (!retval) 3649 return NULL; 3650 3651 if (outlen) { 3652 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST; 3653 outreq.param_hdr.length = htons(outlen); 3654 outreq.request_seq = htonl(asoc->strreset_outseq); 3655 outreq.response_seq = htonl(asoc->strreset_inseq - 1); 3656 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1); 3657 3658 sctp_addto_chunk(retval, sizeof(outreq), &outreq); 3659 3660 if (stream_len) 3661 sctp_addto_chunk(retval, stream_len, stream_list); 3662 } 3663 3664 if (inlen) { 3665 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST; 3666 inreq.param_hdr.length = htons(inlen); 3667 inreq.request_seq = htonl(asoc->strreset_outseq + out); 3668 3669 sctp_addto_chunk(retval, sizeof(inreq), &inreq); 3670 3671 if (stream_len) 3672 sctp_addto_chunk(retval, stream_len, stream_list); 3673 } 3674 3675 return retval; 3676 } 3677 3678 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL) 3679 * 0 1 2 3 3680 * 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 3681 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3682 * | Parameter Type = 15 | Parameter Length = 8 | 3683 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3684 * | Re-configuration Request Sequence Number | 3685 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3686 */ 3687 struct sctp_chunk *sctp_make_strreset_tsnreq( 3688 const struct sctp_association *asoc) 3689 { 3690 struct sctp_strreset_tsnreq tsnreq; 3691 __u16 length = sizeof(tsnreq); 3692 struct sctp_chunk *retval; 3693 3694 retval = sctp_make_reconf(asoc, length); 3695 if (!retval) 3696 return NULL; 3697 3698 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST; 3699 tsnreq.param_hdr.length = htons(length); 3700 tsnreq.request_seq = htonl(asoc->strreset_outseq); 3701 3702 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq); 3703 3704 return retval; 3705 } 3706 3707 /* RE-CONFIG 4.5/4.6 (ADD STREAM) 3708 * 0 1 2 3 3709 * 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 3710 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3711 * | Parameter Type = 17 | Parameter Length = 12 | 3712 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3713 * | Re-configuration Request Sequence Number | 3714 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3715 * | Number of new streams | Reserved | 3716 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3717 */ 3718 struct sctp_chunk *sctp_make_strreset_addstrm( 3719 const struct sctp_association *asoc, 3720 __u16 out, __u16 in) 3721 { 3722 struct sctp_strreset_addstrm addstrm; 3723 __u16 size = sizeof(addstrm); 3724 struct sctp_chunk *retval; 3725 3726 retval = sctp_make_reconf(asoc, (!!out + !!in) * size); 3727 if (!retval) 3728 return NULL; 3729 3730 if (out) { 3731 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS; 3732 addstrm.param_hdr.length = htons(size); 3733 addstrm.number_of_streams = htons(out); 3734 addstrm.request_seq = htonl(asoc->strreset_outseq); 3735 addstrm.reserved = 0; 3736 3737 sctp_addto_chunk(retval, size, &addstrm); 3738 } 3739 3740 if (in) { 3741 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS; 3742 addstrm.param_hdr.length = htons(size); 3743 addstrm.number_of_streams = htons(in); 3744 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out); 3745 addstrm.reserved = 0; 3746 3747 sctp_addto_chunk(retval, size, &addstrm); 3748 } 3749 3750 return retval; 3751 } 3752 3753 /* RE-CONFIG 4.4 (RESP) 3754 * 0 1 2 3 3755 * 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 3756 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3757 * | Parameter Type = 16 | Parameter Length | 3758 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3759 * | Re-configuration Response Sequence Number | 3760 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3761 * | Result | 3762 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3763 */ 3764 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc, 3765 __u32 result, __u32 sn) 3766 { 3767 struct sctp_strreset_resp resp; 3768 __u16 length = sizeof(resp); 3769 struct sctp_chunk *retval; 3770 3771 retval = sctp_make_reconf(asoc, length); 3772 if (!retval) 3773 return NULL; 3774 3775 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3776 resp.param_hdr.length = htons(length); 3777 resp.response_seq = htonl(sn); 3778 resp.result = htonl(result); 3779 3780 sctp_addto_chunk(retval, sizeof(resp), &resp); 3781 3782 return retval; 3783 } 3784 3785 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP) 3786 * 0 1 2 3 3787 * 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 3788 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3789 * | Parameter Type = 16 | Parameter Length | 3790 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3791 * | Re-configuration Response Sequence Number | 3792 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3793 * | Result | 3794 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3795 * | Sender's Next TSN (optional) | 3796 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3797 * | Receiver's Next TSN (optional) | 3798 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3799 */ 3800 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc, 3801 __u32 result, __u32 sn, 3802 __u32 sender_tsn, 3803 __u32 receiver_tsn) 3804 { 3805 struct sctp_strreset_resptsn tsnresp; 3806 __u16 length = sizeof(tsnresp); 3807 struct sctp_chunk *retval; 3808 3809 retval = sctp_make_reconf(asoc, length); 3810 if (!retval) 3811 return NULL; 3812 3813 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3814 tsnresp.param_hdr.length = htons(length); 3815 3816 tsnresp.response_seq = htonl(sn); 3817 tsnresp.result = htonl(result); 3818 tsnresp.senders_next_tsn = htonl(sender_tsn); 3819 tsnresp.receivers_next_tsn = htonl(receiver_tsn); 3820 3821 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp); 3822 3823 return retval; 3824 } 3825 3826 bool sctp_verify_reconf(const struct sctp_association *asoc, 3827 struct sctp_chunk *chunk, 3828 struct sctp_paramhdr **errp) 3829 { 3830 struct sctp_reconf_chunk *hdr; 3831 union sctp_params param; 3832 __be16 last = 0; 3833 __u16 cnt = 0; 3834 3835 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; 3836 sctp_walk_params(param, hdr, params) { 3837 __u16 length = ntohs(param.p->length); 3838 3839 *errp = param.p; 3840 if (cnt++ > 2) 3841 return false; 3842 switch (param.p->type) { 3843 case SCTP_PARAM_RESET_OUT_REQUEST: 3844 if (length < sizeof(struct sctp_strreset_outreq) || 3845 (last && last != SCTP_PARAM_RESET_RESPONSE && 3846 last != SCTP_PARAM_RESET_IN_REQUEST)) 3847 return false; 3848 break; 3849 case SCTP_PARAM_RESET_IN_REQUEST: 3850 if (length < sizeof(struct sctp_strreset_inreq) || 3851 (last && last != SCTP_PARAM_RESET_OUT_REQUEST)) 3852 return false; 3853 break; 3854 case SCTP_PARAM_RESET_RESPONSE: 3855 if ((length != sizeof(struct sctp_strreset_resp) && 3856 length != sizeof(struct sctp_strreset_resptsn)) || 3857 (last && last != SCTP_PARAM_RESET_RESPONSE && 3858 last != SCTP_PARAM_RESET_OUT_REQUEST)) 3859 return false; 3860 break; 3861 case SCTP_PARAM_RESET_TSN_REQUEST: 3862 if (length != 3863 sizeof(struct sctp_strreset_tsnreq) || last) 3864 return false; 3865 break; 3866 case SCTP_PARAM_RESET_ADD_IN_STREAMS: 3867 if (length != sizeof(struct sctp_strreset_addstrm) || 3868 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS)) 3869 return false; 3870 break; 3871 case SCTP_PARAM_RESET_ADD_OUT_STREAMS: 3872 if (length != sizeof(struct sctp_strreset_addstrm) || 3873 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS)) 3874 return false; 3875 break; 3876 default: 3877 return false; 3878 } 3879 3880 last = param.p->type; 3881 } 3882 3883 return true; 3884 } 3885