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