1 /* SCTP kernel implementation 2 * (C) Copyright IBM Corp. 2001, 2004 3 * Copyright (c) 1999-2000 Cisco, Inc. 4 * Copyright (c) 1999-2001 Motorola, Inc. 5 * Copyright (c) 2001-2002 Intel Corp. 6 * 7 * This file is part of the SCTP kernel implementation 8 * 9 * These functions work with the state functions in sctp_sm_statefuns.c 10 * to implement the state operations. These functions implement the 11 * steps which require modifying existing data structures. 12 * 13 * This SCTP implementation is free software; 14 * you can redistribute it and/or modify it under the terms of 15 * the GNU General Public License as published by 16 * the Free Software Foundation; either version 2, or (at your option) 17 * any later version. 18 * 19 * This SCTP implementation is distributed in the hope that it 20 * will be useful, but WITHOUT ANY WARRANTY; without even the implied 21 * ************************ 22 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 23 * See the GNU General Public License for more details. 24 * 25 * You should have received a copy of the GNU General Public License 26 * along with GNU CC; see the file COPYING. If not, see 27 * <http://www.gnu.org/licenses/>. 28 * 29 * Please send any bug reports or fixes you make to the 30 * email address(es): 31 * lksctp developers <linux-sctp@vger.kernel.org> 32 * 33 * Written or modified by: 34 * La Monte H.P. Yarroll <piggy@acm.org> 35 * Karl Knutson <karl@athena.chicago.il.us> 36 * C. Robin <chris@hundredacre.ac.uk> 37 * Jon Grimm <jgrimm@us.ibm.com> 38 * Xingang Guo <xingang.guo@intel.com> 39 * Dajiang Zhang <dajiang.zhang@nokia.com> 40 * Sridhar Samudrala <sri@us.ibm.com> 41 * Daisy Chang <daisyc@us.ibm.com> 42 * Ardelle Fan <ardelle.fan@intel.com> 43 * Kevin Gao <kevin.gao@intel.com> 44 */ 45 46 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 47 48 #include <crypto/hash.h> 49 #include <linux/types.h> 50 #include <linux/kernel.h> 51 #include <linux/ip.h> 52 #include <linux/ipv6.h> 53 #include <linux/net.h> 54 #include <linux/inet.h> 55 #include <linux/scatterlist.h> 56 #include <linux/slab.h> 57 #include <net/sock.h> 58 59 #include <linux/skbuff.h> 60 #include <linux/random.h> /* for get_random_bytes */ 61 #include <net/sctp/sctp.h> 62 #include <net/sctp/sm.h> 63 64 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 65 __u8 type, __u8 flags, int paylen, 66 gfp_t gfp); 67 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 68 __u8 flags, int paylen, gfp_t gfp); 69 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 70 __u8 type, __u8 flags, int paylen, 71 gfp_t gfp); 72 static struct sctp_cookie_param *sctp_pack_cookie( 73 const struct sctp_endpoint *ep, 74 const struct sctp_association *asoc, 75 const struct sctp_chunk *init_chunk, 76 int *cookie_len, 77 const __u8 *raw_addrs, int addrs_len); 78 static int sctp_process_param(struct sctp_association *asoc, 79 union sctp_params param, 80 const union sctp_addr *peer_addr, 81 gfp_t gfp); 82 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 83 const void *data); 84 static void *sctp_addto_chunk_fixed(struct sctp_chunk *, int len, 85 const void *data); 86 87 /* Control chunk destructor */ 88 static void sctp_control_release_owner(struct sk_buff *skb) 89 { 90 /*TODO: do memory release */ 91 } 92 93 static void sctp_control_set_owner_w(struct sctp_chunk *chunk) 94 { 95 struct sctp_association *asoc = chunk->asoc; 96 struct sk_buff *skb = chunk->skb; 97 98 /* TODO: properly account for control chunks. 99 * To do it right we'll need: 100 * 1) endpoint if association isn't known. 101 * 2) proper memory accounting. 102 * 103 * For now don't do anything for now. 104 */ 105 skb->sk = asoc ? asoc->base.sk : NULL; 106 skb->destructor = sctp_control_release_owner; 107 } 108 109 /* What was the inbound interface for this chunk? */ 110 int sctp_chunk_iif(const struct sctp_chunk *chunk) 111 { 112 struct sk_buff *skb = chunk->skb; 113 114 return SCTP_INPUT_CB(skb)->af->skb_iif(skb); 115 } 116 117 /* RFC 2960 3.3.2 Initiation (INIT) (1) 118 * 119 * Note 2: The ECN capable field is reserved for future use of 120 * Explicit Congestion Notification. 121 */ 122 static const struct sctp_paramhdr ecap_param = { 123 SCTP_PARAM_ECN_CAPABLE, 124 cpu_to_be16(sizeof(struct sctp_paramhdr)), 125 }; 126 static const struct sctp_paramhdr prsctp_param = { 127 SCTP_PARAM_FWD_TSN_SUPPORT, 128 cpu_to_be16(sizeof(struct sctp_paramhdr)), 129 }; 130 131 /* A helper to initialize an op error inside a 132 * provided chunk, as most cause codes will be embedded inside an 133 * abort chunk. 134 */ 135 void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, 136 size_t paylen) 137 { 138 struct sctp_errhdr err; 139 __u16 len; 140 141 /* Cause code constants are now defined in network order. */ 142 err.cause = cause_code; 143 len = sizeof(err) + paylen; 144 err.length = htons(len); 145 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(err), &err); 146 } 147 148 /* A helper to initialize an op error inside a 149 * provided chunk, as most cause codes will be embedded inside an 150 * abort chunk. Differs from sctp_init_cause in that it won't oops 151 * if there isn't enough space in the op error chunk 152 */ 153 static int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code, 154 size_t paylen) 155 { 156 struct sctp_errhdr err; 157 __u16 len; 158 159 /* Cause code constants are now defined in network order. */ 160 err.cause = cause_code; 161 len = sizeof(err) + paylen; 162 err.length = htons(len); 163 164 if (skb_tailroom(chunk->skb) < len) 165 return -ENOSPC; 166 167 chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk, sizeof(err), &err); 168 169 return 0; 170 } 171 /* 3.3.2 Initiation (INIT) (1) 172 * 173 * This chunk is used to initiate a SCTP association between two 174 * endpoints. The format of the INIT chunk is shown below: 175 * 176 * 0 1 2 3 177 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 178 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 179 * | Type = 1 | Chunk Flags | Chunk Length | 180 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 181 * | Initiate Tag | 182 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 183 * | Advertised Receiver Window Credit (a_rwnd) | 184 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 185 * | Number of Outbound Streams | Number of Inbound Streams | 186 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 187 * | Initial TSN | 188 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 189 * \ \ 190 * / Optional/Variable-Length Parameters / 191 * \ \ 192 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 193 * 194 * 195 * The INIT chunk contains the following parameters. Unless otherwise 196 * noted, each parameter MUST only be included once in the INIT chunk. 197 * 198 * Fixed Parameters Status 199 * ---------------------------------------------- 200 * Initiate Tag Mandatory 201 * Advertised Receiver Window Credit Mandatory 202 * Number of Outbound Streams Mandatory 203 * Number of Inbound Streams Mandatory 204 * Initial TSN Mandatory 205 * 206 * Variable Parameters Status Type Value 207 * ------------------------------------------------------------- 208 * IPv4 Address (Note 1) Optional 5 209 * IPv6 Address (Note 1) Optional 6 210 * Cookie Preservative Optional 9 211 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000) 212 * Host Name Address (Note 3) Optional 11 213 * Supported Address Types (Note 4) Optional 12 214 */ 215 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc, 216 const struct sctp_bind_addr *bp, 217 gfp_t gfp, int vparam_len) 218 { 219 struct net *net = sock_net(asoc->base.sk); 220 struct sctp_supported_ext_param ext_param; 221 struct sctp_adaptation_ind_param aiparam; 222 struct sctp_paramhdr *auth_chunks = NULL; 223 struct sctp_paramhdr *auth_hmacs = NULL; 224 struct sctp_supported_addrs_param sat; 225 struct sctp_endpoint *ep = asoc->ep; 226 struct sctp_chunk *retval = NULL; 227 int num_types, addrs_len = 0; 228 struct sctp_inithdr init; 229 union sctp_params addrs; 230 struct sctp_sock *sp; 231 __u8 extensions[5]; 232 size_t chunksize; 233 __be16 types[2]; 234 int num_ext = 0; 235 236 /* RFC 2960 3.3.2 Initiation (INIT) (1) 237 * 238 * Note 1: The INIT chunks can contain multiple addresses that 239 * can be IPv4 and/or IPv6 in any combination. 240 */ 241 242 /* Convert the provided bind address list to raw format. */ 243 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp); 244 245 init.init_tag = htonl(asoc->c.my_vtag); 246 init.a_rwnd = htonl(asoc->rwnd); 247 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 248 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 249 init.initial_tsn = htonl(asoc->c.initial_tsn); 250 251 /* How many address types are needed? */ 252 sp = sctp_sk(asoc->base.sk); 253 num_types = sp->pf->supported_addrs(sp, types); 254 255 chunksize = sizeof(init) + addrs_len; 256 chunksize += SCTP_PAD4(SCTP_SAT_LEN(num_types)); 257 chunksize += sizeof(ecap_param); 258 259 if (asoc->prsctp_enable) 260 chunksize += sizeof(prsctp_param); 261 262 /* ADDIP: Section 4.2.7: 263 * An implementation supporting this extension [ADDIP] MUST list 264 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and 265 * INIT-ACK parameters. 266 */ 267 if (net->sctp.addip_enable) { 268 extensions[num_ext] = SCTP_CID_ASCONF; 269 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 270 num_ext += 2; 271 } 272 273 if (asoc->reconf_enable) { 274 extensions[num_ext] = SCTP_CID_RECONF; 275 num_ext += 1; 276 } 277 278 if (sp->adaptation_ind) 279 chunksize += sizeof(aiparam); 280 281 if (sp->strm_interleave) { 282 extensions[num_ext] = SCTP_CID_I_DATA; 283 num_ext += 1; 284 } 285 286 chunksize += vparam_len; 287 288 /* Account for AUTH related parameters */ 289 if (ep->auth_enable) { 290 /* Add random parameter length*/ 291 chunksize += sizeof(asoc->c.auth_random); 292 293 /* Add HMACS parameter length if any were defined */ 294 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; 295 if (auth_hmacs->length) 296 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 297 else 298 auth_hmacs = NULL; 299 300 /* Add CHUNKS parameter length */ 301 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; 302 if (auth_chunks->length) 303 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 304 else 305 auth_chunks = NULL; 306 307 extensions[num_ext] = SCTP_CID_AUTH; 308 num_ext += 1; 309 } 310 311 /* If we have any extensions to report, account for that */ 312 if (num_ext) 313 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext); 314 315 /* RFC 2960 3.3.2 Initiation (INIT) (1) 316 * 317 * Note 3: An INIT chunk MUST NOT contain more than one Host 318 * Name address parameter. Moreover, the sender of the INIT 319 * MUST NOT combine any other address types with the Host Name 320 * address in the INIT. The receiver of INIT MUST ignore any 321 * other address types if the Host Name address parameter is 322 * present in the received INIT chunk. 323 * 324 * PLEASE DO NOT FIXME [This version does not support Host Name.] 325 */ 326 327 retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp); 328 if (!retval) 329 goto nodata; 330 331 retval->subh.init_hdr = 332 sctp_addto_chunk(retval, sizeof(init), &init); 333 retval->param_hdr.v = 334 sctp_addto_chunk(retval, addrs_len, addrs.v); 335 336 /* RFC 2960 3.3.2 Initiation (INIT) (1) 337 * 338 * Note 4: This parameter, when present, specifies all the 339 * address types the sending endpoint can support. The absence 340 * of this parameter indicates that the sending endpoint can 341 * support any address type. 342 */ 343 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES; 344 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types)); 345 sctp_addto_chunk(retval, sizeof(sat), &sat); 346 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types); 347 348 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 349 350 /* Add the supported extensions parameter. Be nice and add this 351 * fist before addiding the parameters for the extensions themselves 352 */ 353 if (num_ext) { 354 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 355 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext); 356 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); 357 sctp_addto_param(retval, num_ext, extensions); 358 } 359 360 if (asoc->prsctp_enable) 361 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 362 363 if (sp->adaptation_ind) { 364 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 365 aiparam.param_hdr.length = htons(sizeof(aiparam)); 366 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 367 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 368 } 369 370 /* Add SCTP-AUTH chunks to the parameter list */ 371 if (ep->auth_enable) { 372 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random), 373 asoc->c.auth_random); 374 if (auth_hmacs) 375 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 376 auth_hmacs); 377 if (auth_chunks) 378 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 379 auth_chunks); 380 } 381 nodata: 382 kfree(addrs.v); 383 return retval; 384 } 385 386 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, 387 const struct sctp_chunk *chunk, 388 gfp_t gfp, int unkparam_len) 389 { 390 struct sctp_supported_ext_param ext_param; 391 struct sctp_adaptation_ind_param aiparam; 392 struct sctp_paramhdr *auth_chunks = NULL; 393 struct sctp_paramhdr *auth_random = NULL; 394 struct sctp_paramhdr *auth_hmacs = NULL; 395 struct sctp_chunk *retval = NULL; 396 struct sctp_cookie_param *cookie; 397 struct sctp_inithdr initack; 398 union sctp_params addrs; 399 struct sctp_sock *sp; 400 __u8 extensions[5]; 401 size_t chunksize; 402 int num_ext = 0; 403 int cookie_len; 404 int addrs_len; 405 406 /* Note: there may be no addresses to embed. */ 407 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp); 408 409 initack.init_tag = htonl(asoc->c.my_vtag); 410 initack.a_rwnd = htonl(asoc->rwnd); 411 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 412 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 413 initack.initial_tsn = htonl(asoc->c.initial_tsn); 414 415 /* FIXME: We really ought to build the cookie right 416 * into the packet instead of allocating more fresh memory. 417 */ 418 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len, 419 addrs.v, addrs_len); 420 if (!cookie) 421 goto nomem_cookie; 422 423 /* Calculate the total size of allocation, include the reserved 424 * space for reporting unknown parameters if it is specified. 425 */ 426 sp = sctp_sk(asoc->base.sk); 427 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len; 428 429 /* Tell peer that we'll do ECN only if peer advertised such cap. */ 430 if (asoc->peer.ecn_capable) 431 chunksize += sizeof(ecap_param); 432 433 if (asoc->peer.prsctp_capable) 434 chunksize += sizeof(prsctp_param); 435 436 if (asoc->peer.asconf_capable) { 437 extensions[num_ext] = SCTP_CID_ASCONF; 438 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 439 num_ext += 2; 440 } 441 442 if (asoc->peer.reconf_capable) { 443 extensions[num_ext] = SCTP_CID_RECONF; 444 num_ext += 1; 445 } 446 447 if (sp->adaptation_ind) 448 chunksize += sizeof(aiparam); 449 450 if (asoc->intl_enable) { 451 extensions[num_ext] = SCTP_CID_I_DATA; 452 num_ext += 1; 453 } 454 455 if (asoc->peer.auth_capable) { 456 auth_random = (struct sctp_paramhdr *)asoc->c.auth_random; 457 chunksize += ntohs(auth_random->length); 458 459 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; 460 if (auth_hmacs->length) 461 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 462 else 463 auth_hmacs = NULL; 464 465 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; 466 if (auth_chunks->length) 467 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 468 else 469 auth_chunks = NULL; 470 471 extensions[num_ext] = SCTP_CID_AUTH; 472 num_ext += 1; 473 } 474 475 if (num_ext) 476 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext); 477 478 /* Now allocate and fill out the chunk. */ 479 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp); 480 if (!retval) 481 goto nomem_chunk; 482 483 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 484 * 485 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 486 * HEARTBEAT ACK, * etc.) to the same destination transport 487 * address from which it received the DATA or control chunk 488 * to which it is replying. 489 * 490 * [INIT ACK back to where the INIT came from.] 491 */ 492 retval->transport = chunk->transport; 493 494 retval->subh.init_hdr = 495 sctp_addto_chunk(retval, sizeof(initack), &initack); 496 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); 497 sctp_addto_chunk(retval, cookie_len, cookie); 498 if (asoc->peer.ecn_capable) 499 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 500 if (num_ext) { 501 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 502 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext); 503 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); 504 sctp_addto_param(retval, num_ext, extensions); 505 } 506 if (asoc->peer.prsctp_capable) 507 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 508 509 if (sp->adaptation_ind) { 510 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 511 aiparam.param_hdr.length = htons(sizeof(aiparam)); 512 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 513 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 514 } 515 516 if (asoc->peer.auth_capable) { 517 sctp_addto_chunk(retval, ntohs(auth_random->length), 518 auth_random); 519 if (auth_hmacs) 520 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 521 auth_hmacs); 522 if (auth_chunks) 523 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 524 auth_chunks); 525 } 526 527 /* We need to remove the const qualifier at this point. */ 528 retval->asoc = (struct sctp_association *) asoc; 529 530 nomem_chunk: 531 kfree(cookie); 532 nomem_cookie: 533 kfree(addrs.v); 534 return retval; 535 } 536 537 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10): 538 * 539 * This chunk is used only during the initialization of an association. 540 * It is sent by the initiator of an association to its peer to complete 541 * the initialization process. This chunk MUST precede any DATA chunk 542 * sent within the association, but MAY be bundled with one or more DATA 543 * chunks in the same packet. 544 * 545 * 0 1 2 3 546 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 547 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 548 * | Type = 10 |Chunk Flags | Length | 549 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 550 * / Cookie / 551 * \ \ 552 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 553 * 554 * Chunk Flags: 8 bit 555 * 556 * Set to zero on transmit and ignored on receipt. 557 * 558 * Length: 16 bits (unsigned integer) 559 * 560 * Set to the size of the chunk in bytes, including the 4 bytes of 561 * the chunk header and the size of the Cookie. 562 * 563 * Cookie: variable size 564 * 565 * This field must contain the exact cookie received in the 566 * State Cookie parameter from the previous INIT ACK. 567 * 568 * An implementation SHOULD make the cookie as small as possible 569 * to insure interoperability. 570 */ 571 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, 572 const struct sctp_chunk *chunk) 573 { 574 struct sctp_chunk *retval; 575 int cookie_len; 576 void *cookie; 577 578 cookie = asoc->peer.cookie; 579 cookie_len = asoc->peer.cookie_len; 580 581 /* Build a cookie echo chunk. */ 582 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0, 583 cookie_len, GFP_ATOMIC); 584 if (!retval) 585 goto nodata; 586 retval->subh.cookie_hdr = 587 sctp_addto_chunk(retval, cookie_len, cookie); 588 589 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 590 * 591 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 592 * HEARTBEAT ACK, * etc.) to the same destination transport 593 * address from which it * received the DATA or control chunk 594 * to which it is replying. 595 * 596 * [COOKIE ECHO back to where the INIT ACK came from.] 597 */ 598 if (chunk) 599 retval->transport = chunk->transport; 600 601 nodata: 602 return retval; 603 } 604 605 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11): 606 * 607 * This chunk is used only during the initialization of an 608 * association. It is used to acknowledge the receipt of a COOKIE 609 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent 610 * within the association, but MAY be bundled with one or more DATA 611 * chunks or SACK chunk in the same SCTP packet. 612 * 613 * 0 1 2 3 614 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 615 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 616 * | Type = 11 |Chunk Flags | Length = 4 | 617 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 618 * 619 * Chunk Flags: 8 bits 620 * 621 * Set to zero on transmit and ignored on receipt. 622 */ 623 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, 624 const struct sctp_chunk *chunk) 625 { 626 struct sctp_chunk *retval; 627 628 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC); 629 630 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 631 * 632 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 633 * HEARTBEAT ACK, * etc.) to the same destination transport 634 * address from which it * received the DATA or control chunk 635 * to which it is replying. 636 * 637 * [COOKIE ACK back to where the COOKIE ECHO came from.] 638 */ 639 if (retval && chunk) 640 retval->transport = chunk->transport; 641 642 return retval; 643 } 644 645 /* 646 * Appendix A: Explicit Congestion Notification: 647 * CWR: 648 * 649 * RFC 2481 details a specific bit for a sender to send in the header of 650 * its next outbound TCP segment to indicate to its peer that it has 651 * reduced its congestion window. This is termed the CWR bit. For 652 * SCTP the same indication is made by including the CWR chunk. 653 * This chunk contains one data element, i.e. the TSN number that 654 * was sent in the ECNE chunk. This element represents the lowest 655 * TSN number in the datagram that was originally marked with the 656 * CE bit. 657 * 658 * 0 1 2 3 659 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 660 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 661 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 | 662 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 663 * | Lowest TSN Number | 664 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 665 * 666 * Note: The CWR is considered a Control chunk. 667 */ 668 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, 669 const __u32 lowest_tsn, 670 const struct sctp_chunk *chunk) 671 { 672 struct sctp_chunk *retval; 673 struct sctp_cwrhdr cwr; 674 675 cwr.lowest_tsn = htonl(lowest_tsn); 676 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0, 677 sizeof(cwr), GFP_ATOMIC); 678 679 if (!retval) 680 goto nodata; 681 682 retval->subh.ecn_cwr_hdr = 683 sctp_addto_chunk(retval, sizeof(cwr), &cwr); 684 685 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 686 * 687 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 688 * HEARTBEAT ACK, * etc.) to the same destination transport 689 * address from which it * received the DATA or control chunk 690 * to which it is replying. 691 * 692 * [Report a reduced congestion window back to where the ECNE 693 * came from.] 694 */ 695 if (chunk) 696 retval->transport = chunk->transport; 697 698 nodata: 699 return retval; 700 } 701 702 /* Make an ECNE chunk. This is a congestion experienced report. */ 703 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, 704 const __u32 lowest_tsn) 705 { 706 struct sctp_chunk *retval; 707 struct sctp_ecnehdr ecne; 708 709 ecne.lowest_tsn = htonl(lowest_tsn); 710 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0, 711 sizeof(ecne), GFP_ATOMIC); 712 if (!retval) 713 goto nodata; 714 retval->subh.ecne_hdr = 715 sctp_addto_chunk(retval, sizeof(ecne), &ecne); 716 717 nodata: 718 return retval; 719 } 720 721 /* Make a DATA chunk for the given association from the provided 722 * parameters. However, do not populate the data payload. 723 */ 724 struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc, 725 const struct sctp_sndrcvinfo *sinfo, 726 int len, __u8 flags, gfp_t gfp) 727 { 728 struct sctp_chunk *retval; 729 struct sctp_datahdr dp; 730 731 /* We assign the TSN as LATE as possible, not here when 732 * creating the chunk. 733 */ 734 memset(&dp, 0, sizeof(dp)); 735 dp.ppid = sinfo->sinfo_ppid; 736 dp.stream = htons(sinfo->sinfo_stream); 737 738 /* Set the flags for an unordered send. */ 739 if (sinfo->sinfo_flags & SCTP_UNORDERED) 740 flags |= SCTP_DATA_UNORDERED; 741 742 retval = sctp_make_data(asoc, flags, sizeof(dp) + len, gfp); 743 if (!retval) 744 return NULL; 745 746 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp); 747 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo)); 748 749 return retval; 750 } 751 752 /* Create a selective ackowledgement (SACK) for the given 753 * association. This reports on which TSN's we've seen to date, 754 * including duplicates and gaps. 755 */ 756 struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc) 757 { 758 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; 759 struct sctp_association *aptr = (struct sctp_association *)asoc; 760 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; 761 __u16 num_gabs, num_dup_tsns; 762 struct sctp_transport *trans; 763 struct sctp_chunk *retval; 764 struct sctp_sackhdr sack; 765 __u32 ctsn; 766 int len; 767 768 memset(gabs, 0, sizeof(gabs)); 769 ctsn = sctp_tsnmap_get_ctsn(map); 770 771 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn); 772 773 /* How much room is needed in the chunk? */ 774 num_gabs = sctp_tsnmap_num_gabs(map, gabs); 775 num_dup_tsns = sctp_tsnmap_num_dups(map); 776 777 /* Initialize the SACK header. */ 778 sack.cum_tsn_ack = htonl(ctsn); 779 sack.a_rwnd = htonl(asoc->a_rwnd); 780 sack.num_gap_ack_blocks = htons(num_gabs); 781 sack.num_dup_tsns = htons(num_dup_tsns); 782 783 len = sizeof(sack) 784 + sizeof(struct sctp_gap_ack_block) * num_gabs 785 + sizeof(__u32) * num_dup_tsns; 786 787 /* Create the chunk. */ 788 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC); 789 if (!retval) 790 goto nodata; 791 792 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 793 * 794 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 795 * HEARTBEAT ACK, etc.) to the same destination transport 796 * address from which it received the DATA or control chunk to 797 * which it is replying. This rule should also be followed if 798 * the endpoint is bundling DATA chunks together with the 799 * reply chunk. 800 * 801 * However, when acknowledging multiple DATA chunks received 802 * in packets from different source addresses in a single 803 * SACK, the SACK chunk may be transmitted to one of the 804 * destination transport addresses from which the DATA or 805 * control chunks being acknowledged were received. 806 * 807 * [BUG: We do not implement the following paragraph. 808 * Perhaps we should remember the last transport we used for a 809 * SACK and avoid that (if possible) if we have seen any 810 * duplicates. --piggy] 811 * 812 * When a receiver of a duplicate DATA chunk sends a SACK to a 813 * multi- homed endpoint it MAY be beneficial to vary the 814 * destination address and not use the source address of the 815 * DATA chunk. The reason being that receiving a duplicate 816 * from a multi-homed endpoint might indicate that the return 817 * path (as specified in the source address of the DATA chunk) 818 * for the SACK is broken. 819 * 820 * [Send to the address from which we last received a DATA chunk.] 821 */ 822 retval->transport = asoc->peer.last_data_from; 823 824 retval->subh.sack_hdr = 825 sctp_addto_chunk(retval, sizeof(sack), &sack); 826 827 /* Add the gap ack block information. */ 828 if (num_gabs) 829 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, 830 gabs); 831 832 /* Add the duplicate TSN information. */ 833 if (num_dup_tsns) { 834 aptr->stats.idupchunks += num_dup_tsns; 835 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, 836 sctp_tsnmap_get_dups(map)); 837 } 838 /* Once we have a sack generated, check to see what our sack 839 * generation is, if its 0, reset the transports to 0, and reset 840 * the association generation to 1 841 * 842 * The idea is that zero is never used as a valid generation for the 843 * association so no transport will match after a wrap event like this, 844 * Until the next sack 845 */ 846 if (++aptr->peer.sack_generation == 0) { 847 list_for_each_entry(trans, &asoc->peer.transport_addr_list, 848 transports) 849 trans->sack_generation = 0; 850 aptr->peer.sack_generation = 1; 851 } 852 nodata: 853 return retval; 854 } 855 856 /* Make a SHUTDOWN chunk. */ 857 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 858 const struct sctp_chunk *chunk) 859 { 860 struct sctp_shutdownhdr shut; 861 struct sctp_chunk *retval; 862 __u32 ctsn; 863 864 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 865 shut.cum_tsn_ack = htonl(ctsn); 866 867 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0, 868 sizeof(shut), GFP_ATOMIC); 869 if (!retval) 870 goto nodata; 871 872 retval->subh.shutdown_hdr = 873 sctp_addto_chunk(retval, sizeof(shut), &shut); 874 875 if (chunk) 876 retval->transport = chunk->transport; 877 nodata: 878 return retval; 879 } 880 881 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 882 const struct sctp_chunk *chunk) 883 { 884 struct sctp_chunk *retval; 885 886 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0, 887 GFP_ATOMIC); 888 889 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 890 * 891 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 892 * HEARTBEAT ACK, * etc.) to the same destination transport 893 * address from which it * received the DATA or control chunk 894 * to which it is replying. 895 * 896 * [ACK back to where the SHUTDOWN came from.] 897 */ 898 if (retval && chunk) 899 retval->transport = chunk->transport; 900 901 return retval; 902 } 903 904 struct sctp_chunk *sctp_make_shutdown_complete( 905 const struct sctp_association *asoc, 906 const struct sctp_chunk *chunk) 907 { 908 struct sctp_chunk *retval; 909 __u8 flags = 0; 910 911 /* Set the T-bit if we have no association (vtag will be 912 * reflected) 913 */ 914 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; 915 916 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 917 0, GFP_ATOMIC); 918 919 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 920 * 921 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 922 * HEARTBEAT ACK, * etc.) to the same destination transport 923 * address from which it * received the DATA or control chunk 924 * to which it is replying. 925 * 926 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK 927 * came from.] 928 */ 929 if (retval && chunk) 930 retval->transport = chunk->transport; 931 932 return retval; 933 } 934 935 /* Create an ABORT. Note that we set the T bit if we have no 936 * association, except when responding to an INIT (sctpimpguide 2.41). 937 */ 938 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 939 const struct sctp_chunk *chunk, 940 const size_t hint) 941 { 942 struct sctp_chunk *retval; 943 __u8 flags = 0; 944 945 /* Set the T-bit if we have no association and 'chunk' is not 946 * an INIT (vtag will be reflected). 947 */ 948 if (!asoc) { 949 if (chunk && chunk->chunk_hdr && 950 chunk->chunk_hdr->type == SCTP_CID_INIT) 951 flags = 0; 952 else 953 flags = SCTP_CHUNK_FLAG_T; 954 } 955 956 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint, 957 GFP_ATOMIC); 958 959 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 960 * 961 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 962 * HEARTBEAT ACK, * etc.) to the same destination transport 963 * address from which it * received the DATA or control chunk 964 * to which it is replying. 965 * 966 * [ABORT back to where the offender came from.] 967 */ 968 if (retval && chunk) 969 retval->transport = chunk->transport; 970 971 return retval; 972 } 973 974 /* Helper to create ABORT with a NO_USER_DATA error. */ 975 struct sctp_chunk *sctp_make_abort_no_data( 976 const struct sctp_association *asoc, 977 const struct sctp_chunk *chunk, 978 __u32 tsn) 979 { 980 struct sctp_chunk *retval; 981 __be32 payload; 982 983 retval = sctp_make_abort(asoc, chunk, 984 sizeof(struct sctp_errhdr) + sizeof(tsn)); 985 986 if (!retval) 987 goto no_mem; 988 989 /* Put the tsn back into network byte order. */ 990 payload = htonl(tsn); 991 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload)); 992 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload); 993 994 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 995 * 996 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 997 * HEARTBEAT ACK, * etc.) to the same destination transport 998 * address from which it * received the DATA or control chunk 999 * to which it is replying. 1000 * 1001 * [ABORT back to where the offender came from.] 1002 */ 1003 if (chunk) 1004 retval->transport = chunk->transport; 1005 1006 no_mem: 1007 return retval; 1008 } 1009 1010 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ 1011 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 1012 struct msghdr *msg, 1013 size_t paylen) 1014 { 1015 struct sctp_chunk *retval; 1016 void *payload = NULL; 1017 int err; 1018 1019 retval = sctp_make_abort(asoc, NULL, 1020 sizeof(struct sctp_errhdr) + paylen); 1021 if (!retval) 1022 goto err_chunk; 1023 1024 if (paylen) { 1025 /* Put the msg_iov together into payload. */ 1026 payload = kmalloc(paylen, GFP_KERNEL); 1027 if (!payload) 1028 goto err_payload; 1029 1030 err = memcpy_from_msg(payload, msg, paylen); 1031 if (err < 0) 1032 goto err_copy; 1033 } 1034 1035 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); 1036 sctp_addto_chunk(retval, paylen, payload); 1037 1038 if (paylen) 1039 kfree(payload); 1040 1041 return retval; 1042 1043 err_copy: 1044 kfree(payload); 1045 err_payload: 1046 sctp_chunk_free(retval); 1047 retval = NULL; 1048 err_chunk: 1049 return retval; 1050 } 1051 1052 /* Append bytes to the end of a parameter. Will panic if chunk is not big 1053 * enough. 1054 */ 1055 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 1056 const void *data) 1057 { 1058 int chunklen = ntohs(chunk->chunk_hdr->length); 1059 void *target; 1060 1061 target = skb_put(chunk->skb, len); 1062 1063 if (data) 1064 memcpy(target, data, len); 1065 else 1066 memset(target, 0, len); 1067 1068 /* Adjust the chunk length field. */ 1069 chunk->chunk_hdr->length = htons(chunklen + len); 1070 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1071 1072 return target; 1073 } 1074 1075 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ 1076 struct sctp_chunk *sctp_make_abort_violation( 1077 const struct sctp_association *asoc, 1078 const struct sctp_chunk *chunk, 1079 const __u8 *payload, 1080 const size_t paylen) 1081 { 1082 struct sctp_chunk *retval; 1083 struct sctp_paramhdr phdr; 1084 1085 retval = sctp_make_abort(asoc, chunk, sizeof(struct sctp_errhdr) + 1086 paylen + sizeof(phdr)); 1087 if (!retval) 1088 goto end; 1089 1090 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen + 1091 sizeof(phdr)); 1092 1093 phdr.type = htons(chunk->chunk_hdr->type); 1094 phdr.length = chunk->chunk_hdr->length; 1095 sctp_addto_chunk(retval, paylen, payload); 1096 sctp_addto_param(retval, sizeof(phdr), &phdr); 1097 1098 end: 1099 return retval; 1100 } 1101 1102 struct sctp_chunk *sctp_make_violation_paramlen( 1103 const struct sctp_association *asoc, 1104 const struct sctp_chunk *chunk, 1105 struct sctp_paramhdr *param) 1106 { 1107 static const char error[] = "The following parameter had invalid length:"; 1108 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr) + 1109 sizeof(*param); 1110 struct sctp_chunk *retval; 1111 1112 retval = sctp_make_abort(asoc, chunk, payload_len); 1113 if (!retval) 1114 goto nodata; 1115 1116 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, 1117 sizeof(error) + sizeof(*param)); 1118 sctp_addto_chunk(retval, sizeof(error), error); 1119 sctp_addto_param(retval, sizeof(*param), param); 1120 1121 nodata: 1122 return retval; 1123 } 1124 1125 struct sctp_chunk *sctp_make_violation_max_retrans( 1126 const struct sctp_association *asoc, 1127 const struct sctp_chunk *chunk) 1128 { 1129 static const char error[] = "Association exceeded its max_retans count"; 1130 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr); 1131 struct sctp_chunk *retval; 1132 1133 retval = sctp_make_abort(asoc, chunk, payload_len); 1134 if (!retval) 1135 goto nodata; 1136 1137 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error)); 1138 sctp_addto_chunk(retval, sizeof(error), error); 1139 1140 nodata: 1141 return retval; 1142 } 1143 1144 /* Make a HEARTBEAT chunk. */ 1145 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1146 const struct sctp_transport *transport) 1147 { 1148 struct sctp_sender_hb_info hbinfo; 1149 struct sctp_chunk *retval; 1150 1151 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, 1152 sizeof(hbinfo), GFP_ATOMIC); 1153 1154 if (!retval) 1155 goto nodata; 1156 1157 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; 1158 hbinfo.param_hdr.length = htons(sizeof(hbinfo)); 1159 hbinfo.daddr = transport->ipaddr; 1160 hbinfo.sent_at = jiffies; 1161 hbinfo.hb_nonce = transport->hb_nonce; 1162 1163 /* Cast away the 'const', as this is just telling the chunk 1164 * what transport it belongs to. 1165 */ 1166 retval->transport = (struct sctp_transport *) transport; 1167 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo), 1168 &hbinfo); 1169 1170 nodata: 1171 return retval; 1172 } 1173 1174 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1175 const struct sctp_chunk *chunk, 1176 const void *payload, 1177 const size_t paylen) 1178 { 1179 struct sctp_chunk *retval; 1180 1181 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen, 1182 GFP_ATOMIC); 1183 if (!retval) 1184 goto nodata; 1185 1186 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1187 1188 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1189 * 1190 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1191 * HEARTBEAT ACK, * etc.) to the same destination transport 1192 * address from which it * received the DATA or control chunk 1193 * to which it is replying. 1194 * 1195 * [HBACK back to where the HEARTBEAT came from.] 1196 */ 1197 if (chunk) 1198 retval->transport = chunk->transport; 1199 1200 nodata: 1201 return retval; 1202 } 1203 1204 /* Create an Operation Error chunk with the specified space reserved. 1205 * This routine can be used for containing multiple causes in the chunk. 1206 */ 1207 static struct sctp_chunk *sctp_make_op_error_space( 1208 const struct sctp_association *asoc, 1209 const struct sctp_chunk *chunk, 1210 size_t size) 1211 { 1212 struct sctp_chunk *retval; 1213 1214 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0, 1215 sizeof(struct sctp_errhdr) + size, 1216 GFP_ATOMIC); 1217 if (!retval) 1218 goto nodata; 1219 1220 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1221 * 1222 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1223 * HEARTBEAT ACK, etc.) to the same destination transport 1224 * address from which it received the DATA or control chunk 1225 * to which it is replying. 1226 * 1227 */ 1228 if (chunk) 1229 retval->transport = chunk->transport; 1230 1231 nodata: 1232 return retval; 1233 } 1234 1235 /* Create an Operation Error chunk of a fixed size, 1236 * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) 1237 * This is a helper function to allocate an error chunk for 1238 * for those invalid parameter codes in which we may not want 1239 * to report all the errors, if the incoming chunk is large 1240 */ 1241 static inline struct sctp_chunk *sctp_make_op_error_fixed( 1242 const struct sctp_association *asoc, 1243 const struct sctp_chunk *chunk) 1244 { 1245 size_t size = asoc ? asoc->pathmtu : 0; 1246 1247 if (!size) 1248 size = SCTP_DEFAULT_MAXSEGMENT; 1249 1250 return sctp_make_op_error_space(asoc, chunk, size); 1251 } 1252 1253 /* Create an Operation Error chunk. */ 1254 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1255 const struct sctp_chunk *chunk, 1256 __be16 cause_code, const void *payload, 1257 size_t paylen, size_t reserve_tail) 1258 { 1259 struct sctp_chunk *retval; 1260 1261 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); 1262 if (!retval) 1263 goto nodata; 1264 1265 sctp_init_cause(retval, cause_code, paylen + reserve_tail); 1266 sctp_addto_chunk(retval, paylen, payload); 1267 if (reserve_tail) 1268 sctp_addto_param(retval, reserve_tail, NULL); 1269 1270 nodata: 1271 return retval; 1272 } 1273 1274 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc) 1275 { 1276 struct sctp_authhdr auth_hdr; 1277 struct sctp_hmac *hmac_desc; 1278 struct sctp_chunk *retval; 1279 __u8 *hmac; 1280 1281 /* Get the first hmac that the peer told us to use */ 1282 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1283 if (unlikely(!hmac_desc)) 1284 return NULL; 1285 1286 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0, 1287 hmac_desc->hmac_len + sizeof(auth_hdr), 1288 GFP_ATOMIC); 1289 if (!retval) 1290 return NULL; 1291 1292 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1293 auth_hdr.shkey_id = htons(asoc->active_key_id); 1294 1295 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr), 1296 &auth_hdr); 1297 1298 hmac = skb_put_zero(retval->skb, hmac_desc->hmac_len); 1299 1300 /* Adjust the chunk header to include the empty MAC */ 1301 retval->chunk_hdr->length = 1302 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1303 retval->chunk_end = skb_tail_pointer(retval->skb); 1304 1305 return retval; 1306 } 1307 1308 1309 /******************************************************************** 1310 * 2nd Level Abstractions 1311 ********************************************************************/ 1312 1313 /* Turn an skb into a chunk. 1314 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1315 * 1316 * sctpimpguide-05.txt Section 2.8.2 1317 * M1) Each time a new DATA chunk is transmitted 1318 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1319 * 'TSN.Missing.Report' count will be used to determine missing chunks 1320 * and when to fast retransmit. 1321 * 1322 */ 1323 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1324 const struct sctp_association *asoc, 1325 struct sock *sk, gfp_t gfp) 1326 { 1327 struct sctp_chunk *retval; 1328 1329 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp); 1330 1331 if (!retval) 1332 goto nodata; 1333 if (!sk) 1334 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb); 1335 1336 INIT_LIST_HEAD(&retval->list); 1337 retval->skb = skb; 1338 retval->asoc = (struct sctp_association *)asoc; 1339 retval->singleton = 1; 1340 1341 retval->fast_retransmit = SCTP_CAN_FRTX; 1342 1343 /* Polish the bead hole. */ 1344 INIT_LIST_HEAD(&retval->transmitted_list); 1345 INIT_LIST_HEAD(&retval->frag_list); 1346 SCTP_DBG_OBJCNT_INC(chunk); 1347 refcount_set(&retval->refcnt, 1); 1348 1349 nodata: 1350 return retval; 1351 } 1352 1353 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1354 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1355 union sctp_addr *dest) 1356 { 1357 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1358 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1359 } 1360 1361 /* Extract the source address from a chunk. */ 1362 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1363 { 1364 /* If we have a known transport, use that. */ 1365 if (chunk->transport) { 1366 return &chunk->transport->ipaddr; 1367 } else { 1368 /* Otherwise, extract it from the IP header. */ 1369 return &chunk->source; 1370 } 1371 } 1372 1373 /* Create a new chunk, setting the type and flags headers from the 1374 * arguments, reserving enough space for a 'paylen' byte payload. 1375 */ 1376 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 1377 __u8 type, __u8 flags, int paylen, 1378 gfp_t gfp) 1379 { 1380 struct sctp_chunkhdr *chunk_hdr; 1381 struct sctp_chunk *retval; 1382 struct sk_buff *skb; 1383 struct sock *sk; 1384 1385 /* No need to allocate LL here, as this is only a chunk. */ 1386 skb = alloc_skb(SCTP_PAD4(sizeof(*chunk_hdr) + paylen), gfp); 1387 if (!skb) 1388 goto nodata; 1389 1390 /* Make room for the chunk header. */ 1391 chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr)); 1392 chunk_hdr->type = type; 1393 chunk_hdr->flags = flags; 1394 chunk_hdr->length = htons(sizeof(*chunk_hdr)); 1395 1396 sk = asoc ? asoc->base.sk : NULL; 1397 retval = sctp_chunkify(skb, asoc, sk, gfp); 1398 if (!retval) { 1399 kfree_skb(skb); 1400 goto nodata; 1401 } 1402 1403 retval->chunk_hdr = chunk_hdr; 1404 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr); 1405 1406 /* Determine if the chunk needs to be authenticated */ 1407 if (sctp_auth_send_cid(type, asoc)) 1408 retval->auth = 1; 1409 1410 return retval; 1411 nodata: 1412 return NULL; 1413 } 1414 1415 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 1416 __u8 flags, int paylen, gfp_t gfp) 1417 { 1418 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp); 1419 } 1420 1421 struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc, 1422 __u8 flags, int paylen, gfp_t gfp) 1423 { 1424 return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp); 1425 } 1426 1427 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 1428 __u8 type, __u8 flags, int paylen, 1429 gfp_t gfp) 1430 { 1431 struct sctp_chunk *chunk; 1432 1433 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp); 1434 if (chunk) 1435 sctp_control_set_owner_w(chunk); 1436 1437 return chunk; 1438 } 1439 1440 /* Release the memory occupied by a chunk. */ 1441 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1442 { 1443 BUG_ON(!list_empty(&chunk->list)); 1444 list_del_init(&chunk->transmitted_list); 1445 1446 consume_skb(chunk->skb); 1447 consume_skb(chunk->auth_chunk); 1448 1449 SCTP_DBG_OBJCNT_DEC(chunk); 1450 kmem_cache_free(sctp_chunk_cachep, chunk); 1451 } 1452 1453 /* Possibly, free the chunk. */ 1454 void sctp_chunk_free(struct sctp_chunk *chunk) 1455 { 1456 /* Release our reference on the message tracker. */ 1457 if (chunk->msg) 1458 sctp_datamsg_put(chunk->msg); 1459 1460 sctp_chunk_put(chunk); 1461 } 1462 1463 /* Grab a reference to the chunk. */ 1464 void sctp_chunk_hold(struct sctp_chunk *ch) 1465 { 1466 refcount_inc(&ch->refcnt); 1467 } 1468 1469 /* Release a reference to the chunk. */ 1470 void sctp_chunk_put(struct sctp_chunk *ch) 1471 { 1472 if (refcount_dec_and_test(&ch->refcnt)) 1473 sctp_chunk_destroy(ch); 1474 } 1475 1476 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1477 * enough. 1478 */ 1479 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1480 { 1481 int chunklen = ntohs(chunk->chunk_hdr->length); 1482 int padlen = SCTP_PAD4(chunklen) - chunklen; 1483 void *target; 1484 1485 skb_put_zero(chunk->skb, padlen); 1486 target = skb_put_data(chunk->skb, data, len); 1487 1488 /* Adjust the chunk length field. */ 1489 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1490 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1491 1492 return target; 1493 } 1494 1495 /* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient 1496 * space in the chunk 1497 */ 1498 static void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk, 1499 int len, const void *data) 1500 { 1501 if (skb_tailroom(chunk->skb) >= len) 1502 return sctp_addto_chunk(chunk, len, data); 1503 else 1504 return NULL; 1505 } 1506 1507 /* Append bytes from user space to the end of a chunk. Will panic if 1508 * chunk is not big enough. 1509 * Returns a kernel err value. 1510 */ 1511 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len, 1512 struct iov_iter *from) 1513 { 1514 void *target; 1515 1516 /* Make room in chunk for data. */ 1517 target = skb_put(chunk->skb, len); 1518 1519 /* Copy data (whole iovec) into chunk */ 1520 if (!copy_from_iter_full(target, len, from)) 1521 return -EFAULT; 1522 1523 /* Adjust the chunk length field. */ 1524 chunk->chunk_hdr->length = 1525 htons(ntohs(chunk->chunk_hdr->length) + len); 1526 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1527 1528 return 0; 1529 } 1530 1531 /* Helper function to assign a TSN if needed. This assumes that both 1532 * the data_hdr and association have already been assigned. 1533 */ 1534 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1535 { 1536 struct sctp_stream *stream; 1537 struct sctp_chunk *lchunk; 1538 struct sctp_datamsg *msg; 1539 __u16 ssn, sid; 1540 1541 if (chunk->has_ssn) 1542 return; 1543 1544 /* All fragments will be on the same stream */ 1545 sid = ntohs(chunk->subh.data_hdr->stream); 1546 stream = &chunk->asoc->stream; 1547 1548 /* Now assign the sequence number to the entire message. 1549 * All fragments must have the same stream sequence number. 1550 */ 1551 msg = chunk->msg; 1552 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1553 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1554 ssn = 0; 1555 } else { 1556 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1557 ssn = sctp_ssn_next(stream, out, sid); 1558 else 1559 ssn = sctp_ssn_peek(stream, out, sid); 1560 } 1561 1562 lchunk->subh.data_hdr->ssn = htons(ssn); 1563 lchunk->has_ssn = 1; 1564 } 1565 } 1566 1567 /* Helper function to assign a TSN if needed. This assumes that both 1568 * the data_hdr and association have already been assigned. 1569 */ 1570 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1571 { 1572 if (!chunk->has_tsn) { 1573 /* This is the last possible instant to 1574 * assign a TSN. 1575 */ 1576 chunk->subh.data_hdr->tsn = 1577 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1578 chunk->has_tsn = 1; 1579 } 1580 } 1581 1582 /* Create a CLOSED association to use with an incoming packet. */ 1583 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1584 struct sctp_chunk *chunk, 1585 gfp_t gfp) 1586 { 1587 struct sctp_association *asoc; 1588 enum sctp_scope scope; 1589 struct sk_buff *skb; 1590 1591 /* Create the bare association. */ 1592 scope = sctp_scope(sctp_source(chunk)); 1593 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1594 if (!asoc) 1595 goto nodata; 1596 asoc->temp = 1; 1597 skb = chunk->skb; 1598 /* Create an entry for the source address of the packet. */ 1599 SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1); 1600 1601 nodata: 1602 return asoc; 1603 } 1604 1605 /* Build a cookie representing asoc. 1606 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1607 */ 1608 static struct sctp_cookie_param *sctp_pack_cookie( 1609 const struct sctp_endpoint *ep, 1610 const struct sctp_association *asoc, 1611 const struct sctp_chunk *init_chunk, 1612 int *cookie_len, const __u8 *raw_addrs, 1613 int addrs_len) 1614 { 1615 struct sctp_signed_cookie *cookie; 1616 struct sctp_cookie_param *retval; 1617 int headersize, bodysize; 1618 1619 /* Header size is static data prior to the actual cookie, including 1620 * any padding. 1621 */ 1622 headersize = sizeof(struct sctp_paramhdr) + 1623 (sizeof(struct sctp_signed_cookie) - 1624 sizeof(struct sctp_cookie)); 1625 bodysize = sizeof(struct sctp_cookie) 1626 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1627 1628 /* Pad out the cookie to a multiple to make the signature 1629 * functions simpler to write. 1630 */ 1631 if (bodysize % SCTP_COOKIE_MULTIPLE) 1632 bodysize += SCTP_COOKIE_MULTIPLE 1633 - (bodysize % SCTP_COOKIE_MULTIPLE); 1634 *cookie_len = headersize + bodysize; 1635 1636 /* Clear this memory since we are sending this data structure 1637 * out on the network. 1638 */ 1639 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1640 if (!retval) 1641 goto nodata; 1642 1643 cookie = (struct sctp_signed_cookie *) retval->body; 1644 1645 /* Set up the parameter header. */ 1646 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1647 retval->p.length = htons(*cookie_len); 1648 1649 /* Copy the cookie part of the association itself. */ 1650 cookie->c = asoc->c; 1651 /* Save the raw address list length in the cookie. */ 1652 cookie->c.raw_addr_list_len = addrs_len; 1653 1654 /* Remember PR-SCTP capability. */ 1655 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1656 1657 /* Save adaptation indication in the cookie. */ 1658 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1659 1660 /* Set an expiration time for the cookie. */ 1661 cookie->c.expiration = ktime_add(asoc->cookie_life, 1662 ktime_get_real()); 1663 1664 /* Copy the peer's init packet. */ 1665 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr, 1666 ntohs(init_chunk->chunk_hdr->length)); 1667 1668 /* Copy the raw local address list of the association. */ 1669 memcpy((__u8 *)&cookie->c.peer_init[0] + 1670 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1671 1672 if (sctp_sk(ep->base.sk)->hmac) { 1673 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac); 1674 int err; 1675 1676 /* Sign the message. */ 1677 desc->tfm = sctp_sk(ep->base.sk)->hmac; 1678 desc->flags = 0; 1679 1680 err = crypto_shash_setkey(desc->tfm, ep->secret_key, 1681 sizeof(ep->secret_key)) ?: 1682 crypto_shash_digest(desc, (u8 *)&cookie->c, bodysize, 1683 cookie->signature); 1684 shash_desc_zero(desc); 1685 if (err) 1686 goto free_cookie; 1687 } 1688 1689 return retval; 1690 1691 free_cookie: 1692 kfree(retval); 1693 nodata: 1694 *cookie_len = 0; 1695 return NULL; 1696 } 1697 1698 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1699 struct sctp_association *sctp_unpack_cookie( 1700 const struct sctp_endpoint *ep, 1701 const struct sctp_association *asoc, 1702 struct sctp_chunk *chunk, gfp_t gfp, 1703 int *error, struct sctp_chunk **errp) 1704 { 1705 struct sctp_association *retval = NULL; 1706 int headersize, bodysize, fixed_size; 1707 struct sctp_signed_cookie *cookie; 1708 struct sk_buff *skb = chunk->skb; 1709 struct sctp_cookie *bear_cookie; 1710 __u8 *digest = ep->digest; 1711 enum sctp_scope scope; 1712 unsigned int len; 1713 ktime_t kt; 1714 1715 /* Header size is static data prior to the actual cookie, including 1716 * any padding. 1717 */ 1718 headersize = sizeof(struct sctp_chunkhdr) + 1719 (sizeof(struct sctp_signed_cookie) - 1720 sizeof(struct sctp_cookie)); 1721 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1722 fixed_size = headersize + sizeof(struct sctp_cookie); 1723 1724 /* Verify that the chunk looks like it even has a cookie. 1725 * There must be enough room for our cookie and our peer's 1726 * INIT chunk. 1727 */ 1728 len = ntohs(chunk->chunk_hdr->length); 1729 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1730 goto malformed; 1731 1732 /* Verify that the cookie has been padded out. */ 1733 if (bodysize % SCTP_COOKIE_MULTIPLE) 1734 goto malformed; 1735 1736 /* Process the cookie. */ 1737 cookie = chunk->subh.cookie_hdr; 1738 bear_cookie = &cookie->c; 1739 1740 if (!sctp_sk(ep->base.sk)->hmac) 1741 goto no_hmac; 1742 1743 /* Check the signature. */ 1744 { 1745 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac); 1746 int err; 1747 1748 desc->tfm = sctp_sk(ep->base.sk)->hmac; 1749 desc->flags = 0; 1750 1751 err = crypto_shash_setkey(desc->tfm, ep->secret_key, 1752 sizeof(ep->secret_key)) ?: 1753 crypto_shash_digest(desc, (u8 *)bear_cookie, bodysize, 1754 digest); 1755 shash_desc_zero(desc); 1756 1757 if (err) { 1758 *error = -SCTP_IERROR_NOMEM; 1759 goto fail; 1760 } 1761 } 1762 1763 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1764 *error = -SCTP_IERROR_BAD_SIG; 1765 goto fail; 1766 } 1767 1768 no_hmac: 1769 /* IG Section 2.35.2: 1770 * 3) Compare the port numbers and the verification tag contained 1771 * within the COOKIE ECHO chunk to the actual port numbers and the 1772 * verification tag within the SCTP common header of the received 1773 * packet. If these values do not match the packet MUST be silently 1774 * discarded, 1775 */ 1776 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1777 *error = -SCTP_IERROR_BAD_TAG; 1778 goto fail; 1779 } 1780 1781 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1782 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1783 *error = -SCTP_IERROR_BAD_PORTS; 1784 goto fail; 1785 } 1786 1787 /* Check to see if the cookie is stale. If there is already 1788 * an association, there is no need to check cookie's expiration 1789 * for init collision case of lost COOKIE ACK. 1790 * If skb has been timestamped, then use the stamp, otherwise 1791 * use current time. This introduces a small possibility that 1792 * that a cookie may be considered expired, but his would only slow 1793 * down the new association establishment instead of every packet. 1794 */ 1795 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1796 kt = skb_get_ktime(skb); 1797 else 1798 kt = ktime_get_real(); 1799 1800 if (!asoc && ktime_before(bear_cookie->expiration, kt)) { 1801 /* 1802 * Section 3.3.10.3 Stale Cookie Error (3) 1803 * 1804 * Cause of error 1805 * --------------- 1806 * Stale Cookie Error: Indicates the receipt of a valid State 1807 * Cookie that has expired. 1808 */ 1809 len = ntohs(chunk->chunk_hdr->length); 1810 *errp = sctp_make_op_error_space(asoc, chunk, len); 1811 if (*errp) { 1812 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); 1813 __be32 n = htonl(usecs); 1814 1815 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE, 1816 sizeof(n)); 1817 sctp_addto_chunk(*errp, sizeof(n), &n); 1818 *error = -SCTP_IERROR_STALE_COOKIE; 1819 } else 1820 *error = -SCTP_IERROR_NOMEM; 1821 1822 goto fail; 1823 } 1824 1825 /* Make a new base association. */ 1826 scope = sctp_scope(sctp_source(chunk)); 1827 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1828 if (!retval) { 1829 *error = -SCTP_IERROR_NOMEM; 1830 goto fail; 1831 } 1832 1833 /* Set up our peer's port number. */ 1834 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1835 1836 /* Populate the association from the cookie. */ 1837 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1838 1839 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1840 GFP_ATOMIC) < 0) { 1841 *error = -SCTP_IERROR_NOMEM; 1842 goto fail; 1843 } 1844 1845 /* Also, add the destination address. */ 1846 if (list_empty(&retval->base.bind_addr.address_list)) { 1847 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1848 sizeof(chunk->dest), SCTP_ADDR_SRC, 1849 GFP_ATOMIC); 1850 } 1851 1852 retval->next_tsn = retval->c.initial_tsn; 1853 retval->ctsn_ack_point = retval->next_tsn - 1; 1854 retval->addip_serial = retval->c.initial_tsn; 1855 retval->strreset_outseq = retval->c.initial_tsn; 1856 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1857 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1858 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1859 1860 /* The INIT stuff will be done by the side effects. */ 1861 return retval; 1862 1863 fail: 1864 if (retval) 1865 sctp_association_free(retval); 1866 1867 return NULL; 1868 1869 malformed: 1870 /* Yikes! The packet is either corrupt or deliberately 1871 * malformed. 1872 */ 1873 *error = -SCTP_IERROR_MALFORMED; 1874 goto fail; 1875 } 1876 1877 /******************************************************************** 1878 * 3rd Level Abstractions 1879 ********************************************************************/ 1880 1881 struct __sctp_missing { 1882 __be32 num_missing; 1883 __be16 type; 1884 } __packed; 1885 1886 /* 1887 * Report a missing mandatory parameter. 1888 */ 1889 static int sctp_process_missing_param(const struct sctp_association *asoc, 1890 enum sctp_param paramtype, 1891 struct sctp_chunk *chunk, 1892 struct sctp_chunk **errp) 1893 { 1894 struct __sctp_missing report; 1895 __u16 len; 1896 1897 len = SCTP_PAD4(sizeof(report)); 1898 1899 /* Make an ERROR chunk, preparing enough room for 1900 * returning multiple unknown parameters. 1901 */ 1902 if (!*errp) 1903 *errp = sctp_make_op_error_space(asoc, chunk, len); 1904 1905 if (*errp) { 1906 report.num_missing = htonl(1); 1907 report.type = paramtype; 1908 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1909 sizeof(report)); 1910 sctp_addto_chunk(*errp, sizeof(report), &report); 1911 } 1912 1913 /* Stop processing this chunk. */ 1914 return 0; 1915 } 1916 1917 /* Report an Invalid Mandatory Parameter. */ 1918 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1919 struct sctp_chunk *chunk, 1920 struct sctp_chunk **errp) 1921 { 1922 /* Invalid Mandatory Parameter Error has no payload. */ 1923 1924 if (!*errp) 1925 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1926 1927 if (*errp) 1928 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1929 1930 /* Stop processing this chunk. */ 1931 return 0; 1932 } 1933 1934 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1935 struct sctp_paramhdr *param, 1936 const struct sctp_chunk *chunk, 1937 struct sctp_chunk **errp) 1938 { 1939 /* This is a fatal error. Any accumulated non-fatal errors are 1940 * not reported. 1941 */ 1942 if (*errp) 1943 sctp_chunk_free(*errp); 1944 1945 /* Create an error chunk and fill it in with our payload. */ 1946 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1947 1948 return 0; 1949 } 1950 1951 1952 /* Do not attempt to handle the HOST_NAME parm. However, do 1953 * send back an indicator to the peer. 1954 */ 1955 static int sctp_process_hn_param(const struct sctp_association *asoc, 1956 union sctp_params param, 1957 struct sctp_chunk *chunk, 1958 struct sctp_chunk **errp) 1959 { 1960 __u16 len = ntohs(param.p->length); 1961 1962 /* Processing of the HOST_NAME parameter will generate an 1963 * ABORT. If we've accumulated any non-fatal errors, they 1964 * would be unrecognized parameters and we should not include 1965 * them in the ABORT. 1966 */ 1967 if (*errp) 1968 sctp_chunk_free(*errp); 1969 1970 *errp = sctp_make_op_error_space(asoc, chunk, len); 1971 1972 if (*errp) { 1973 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len); 1974 sctp_addto_chunk(*errp, len, param.v); 1975 } 1976 1977 /* Stop processing this chunk. */ 1978 return 0; 1979 } 1980 1981 static int sctp_verify_ext_param(struct net *net, union sctp_params param) 1982 { 1983 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 1984 int have_asconf = 0; 1985 int have_auth = 0; 1986 int i; 1987 1988 for (i = 0; i < num_ext; i++) { 1989 switch (param.ext->chunks[i]) { 1990 case SCTP_CID_AUTH: 1991 have_auth = 1; 1992 break; 1993 case SCTP_CID_ASCONF: 1994 case SCTP_CID_ASCONF_ACK: 1995 have_asconf = 1; 1996 break; 1997 } 1998 } 1999 2000 /* ADD-IP Security: The draft requires us to ABORT or ignore the 2001 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 2002 * only if ADD-IP is turned on and we are not backward-compatible 2003 * mode. 2004 */ 2005 if (net->sctp.addip_noauth) 2006 return 1; 2007 2008 if (net->sctp.addip_enable && !have_auth && have_asconf) 2009 return 0; 2010 2011 return 1; 2012 } 2013 2014 static void sctp_process_ext_param(struct sctp_association *asoc, 2015 union sctp_params param) 2016 { 2017 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2018 struct net *net = sock_net(asoc->base.sk); 2019 int i; 2020 2021 for (i = 0; i < num_ext; i++) { 2022 switch (param.ext->chunks[i]) { 2023 case SCTP_CID_RECONF: 2024 if (asoc->reconf_enable && 2025 !asoc->peer.reconf_capable) 2026 asoc->peer.reconf_capable = 1; 2027 break; 2028 case SCTP_CID_FWD_TSN: 2029 if (asoc->prsctp_enable && !asoc->peer.prsctp_capable) 2030 asoc->peer.prsctp_capable = 1; 2031 break; 2032 case SCTP_CID_AUTH: 2033 /* if the peer reports AUTH, assume that he 2034 * supports AUTH. 2035 */ 2036 if (asoc->ep->auth_enable) 2037 asoc->peer.auth_capable = 1; 2038 break; 2039 case SCTP_CID_ASCONF: 2040 case SCTP_CID_ASCONF_ACK: 2041 if (net->sctp.addip_enable) 2042 asoc->peer.asconf_capable = 1; 2043 break; 2044 case SCTP_CID_I_DATA: 2045 if (sctp_sk(asoc->base.sk)->strm_interleave) 2046 asoc->intl_enable = 1; 2047 break; 2048 default: 2049 break; 2050 } 2051 } 2052 } 2053 2054 /* RFC 3.2.1 & the Implementers Guide 2.2. 2055 * 2056 * The Parameter Types are encoded such that the 2057 * highest-order two bits specify the action that must be 2058 * taken if the processing endpoint does not recognize the 2059 * Parameter Type. 2060 * 2061 * 00 - Stop processing this parameter; do not process any further 2062 * parameters within this chunk 2063 * 2064 * 01 - Stop processing this parameter, do not process any further 2065 * parameters within this chunk, and report the unrecognized 2066 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2067 * 2068 * 10 - Skip this parameter and continue processing. 2069 * 2070 * 11 - Skip this parameter and continue processing but 2071 * report the unrecognized parameter in an 2072 * 'Unrecognized Parameter' ERROR chunk. 2073 * 2074 * Return value: 2075 * SCTP_IERROR_NO_ERROR - continue with the chunk 2076 * SCTP_IERROR_ERROR - stop and report an error. 2077 * SCTP_IERROR_NOMEME - out of memory. 2078 */ 2079 static enum sctp_ierror sctp_process_unk_param( 2080 const struct sctp_association *asoc, 2081 union sctp_params param, 2082 struct sctp_chunk *chunk, 2083 struct sctp_chunk **errp) 2084 { 2085 int retval = SCTP_IERROR_NO_ERROR; 2086 2087 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2088 case SCTP_PARAM_ACTION_DISCARD: 2089 retval = SCTP_IERROR_ERROR; 2090 break; 2091 case SCTP_PARAM_ACTION_SKIP: 2092 break; 2093 case SCTP_PARAM_ACTION_DISCARD_ERR: 2094 retval = SCTP_IERROR_ERROR; 2095 /* Fall through */ 2096 case SCTP_PARAM_ACTION_SKIP_ERR: 2097 /* Make an ERROR chunk, preparing enough room for 2098 * returning multiple unknown parameters. 2099 */ 2100 if (NULL == *errp) 2101 *errp = sctp_make_op_error_fixed(asoc, chunk); 2102 2103 if (*errp) { 2104 if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2105 SCTP_PAD4(ntohs(param.p->length)))) 2106 sctp_addto_chunk_fixed(*errp, 2107 SCTP_PAD4(ntohs(param.p->length)), 2108 param.v); 2109 } else { 2110 /* If there is no memory for generating the ERROR 2111 * report as specified, an ABORT will be triggered 2112 * to the peer and the association won't be 2113 * established. 2114 */ 2115 retval = SCTP_IERROR_NOMEM; 2116 } 2117 break; 2118 default: 2119 break; 2120 } 2121 2122 return retval; 2123 } 2124 2125 /* Verify variable length parameters 2126 * Return values: 2127 * SCTP_IERROR_ABORT - trigger an ABORT 2128 * SCTP_IERROR_NOMEM - out of memory (abort) 2129 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2130 * SCTP_IERROR_NO_ERROR - continue with the chunk 2131 */ 2132 static enum sctp_ierror sctp_verify_param(struct net *net, 2133 const struct sctp_endpoint *ep, 2134 const struct sctp_association *asoc, 2135 union sctp_params param, 2136 enum sctp_cid cid, 2137 struct sctp_chunk *chunk, 2138 struct sctp_chunk **err_chunk) 2139 { 2140 struct sctp_hmac_algo_param *hmacs; 2141 int retval = SCTP_IERROR_NO_ERROR; 2142 __u16 n_elt, id = 0; 2143 int i; 2144 2145 /* FIXME - This routine is not looking at each parameter per the 2146 * chunk type, i.e., unrecognized parameters should be further 2147 * identified based on the chunk id. 2148 */ 2149 2150 switch (param.p->type) { 2151 case SCTP_PARAM_IPV4_ADDRESS: 2152 case SCTP_PARAM_IPV6_ADDRESS: 2153 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2154 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2155 case SCTP_PARAM_STATE_COOKIE: 2156 case SCTP_PARAM_HEARTBEAT_INFO: 2157 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2158 case SCTP_PARAM_ECN_CAPABLE: 2159 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2160 break; 2161 2162 case SCTP_PARAM_SUPPORTED_EXT: 2163 if (!sctp_verify_ext_param(net, param)) 2164 return SCTP_IERROR_ABORT; 2165 break; 2166 2167 case SCTP_PARAM_SET_PRIMARY: 2168 if (net->sctp.addip_enable) 2169 break; 2170 goto fallthrough; 2171 2172 case SCTP_PARAM_HOST_NAME_ADDRESS: 2173 /* Tell the peer, we won't support this param. */ 2174 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2175 retval = SCTP_IERROR_ABORT; 2176 break; 2177 2178 case SCTP_PARAM_FWD_TSN_SUPPORT: 2179 if (ep->prsctp_enable) 2180 break; 2181 goto fallthrough; 2182 2183 case SCTP_PARAM_RANDOM: 2184 if (!ep->auth_enable) 2185 goto fallthrough; 2186 2187 /* SCTP-AUTH: Secion 6.1 2188 * If the random number is not 32 byte long the association 2189 * MUST be aborted. The ABORT chunk SHOULD contain the error 2190 * cause 'Protocol Violation'. 2191 */ 2192 if (SCTP_AUTH_RANDOM_LENGTH != 2193 ntohs(param.p->length) - sizeof(struct sctp_paramhdr)) { 2194 sctp_process_inv_paramlength(asoc, param.p, 2195 chunk, err_chunk); 2196 retval = SCTP_IERROR_ABORT; 2197 } 2198 break; 2199 2200 case SCTP_PARAM_CHUNKS: 2201 if (!ep->auth_enable) 2202 goto fallthrough; 2203 2204 /* SCTP-AUTH: Section 3.2 2205 * The CHUNKS parameter MUST be included once in the INIT or 2206 * INIT-ACK chunk if the sender wants to receive authenticated 2207 * chunks. Its maximum length is 260 bytes. 2208 */ 2209 if (260 < ntohs(param.p->length)) { 2210 sctp_process_inv_paramlength(asoc, param.p, 2211 chunk, err_chunk); 2212 retval = SCTP_IERROR_ABORT; 2213 } 2214 break; 2215 2216 case SCTP_PARAM_HMAC_ALGO: 2217 if (!ep->auth_enable) 2218 goto fallthrough; 2219 2220 hmacs = (struct sctp_hmac_algo_param *)param.p; 2221 n_elt = (ntohs(param.p->length) - 2222 sizeof(struct sctp_paramhdr)) >> 1; 2223 2224 /* SCTP-AUTH: Section 6.1 2225 * The HMAC algorithm based on SHA-1 MUST be supported and 2226 * included in the HMAC-ALGO parameter. 2227 */ 2228 for (i = 0; i < n_elt; i++) { 2229 id = ntohs(hmacs->hmac_ids[i]); 2230 2231 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2232 break; 2233 } 2234 2235 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2236 sctp_process_inv_paramlength(asoc, param.p, chunk, 2237 err_chunk); 2238 retval = SCTP_IERROR_ABORT; 2239 } 2240 break; 2241 fallthrough: 2242 default: 2243 pr_debug("%s: unrecognized param:%d for chunk:%d\n", 2244 __func__, ntohs(param.p->type), cid); 2245 2246 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2247 break; 2248 } 2249 return retval; 2250 } 2251 2252 /* Verify the INIT packet before we process it. */ 2253 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 2254 const struct sctp_association *asoc, enum sctp_cid cid, 2255 struct sctp_init_chunk *peer_init, 2256 struct sctp_chunk *chunk, struct sctp_chunk **errp) 2257 { 2258 union sctp_params param; 2259 bool has_cookie = false; 2260 int result; 2261 2262 /* Check for missing mandatory parameters. Note: Initial TSN is 2263 * also mandatory, but is not checked here since the valid range 2264 * is 0..2**32-1. RFC4960, section 3.3.3. 2265 */ 2266 if (peer_init->init_hdr.num_outbound_streams == 0 || 2267 peer_init->init_hdr.num_inbound_streams == 0 || 2268 peer_init->init_hdr.init_tag == 0 || 2269 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) 2270 return sctp_process_inv_mandatory(asoc, chunk, errp); 2271 2272 sctp_walk_params(param, peer_init, init_hdr.params) { 2273 if (param.p->type == SCTP_PARAM_STATE_COOKIE) 2274 has_cookie = true; 2275 } 2276 2277 /* There is a possibility that a parameter length was bad and 2278 * in that case we would have stoped walking the parameters. 2279 * The current param.p would point at the bad one. 2280 * Current consensus on the mailing list is to generate a PROTOCOL 2281 * VIOLATION error. We build the ERROR chunk here and let the normal 2282 * error handling code build and send the packet. 2283 */ 2284 if (param.v != (void *)chunk->chunk_end) 2285 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2286 2287 /* The only missing mandatory param possible today is 2288 * the state cookie for an INIT-ACK chunk. 2289 */ 2290 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2291 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2292 chunk, errp); 2293 2294 /* Verify all the variable length parameters */ 2295 sctp_walk_params(param, peer_init, init_hdr.params) { 2296 result = sctp_verify_param(net, ep, asoc, param, cid, 2297 chunk, errp); 2298 switch (result) { 2299 case SCTP_IERROR_ABORT: 2300 case SCTP_IERROR_NOMEM: 2301 return 0; 2302 case SCTP_IERROR_ERROR: 2303 return 1; 2304 case SCTP_IERROR_NO_ERROR: 2305 default: 2306 break; 2307 } 2308 2309 } /* for (loop through all parameters) */ 2310 2311 return 1; 2312 } 2313 2314 /* Unpack the parameters in an INIT packet into an association. 2315 * Returns 0 on failure, else success. 2316 * FIXME: This is an association method. 2317 */ 2318 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2319 const union sctp_addr *peer_addr, 2320 struct sctp_init_chunk *peer_init, gfp_t gfp) 2321 { 2322 struct net *net = sock_net(asoc->base.sk); 2323 struct sctp_transport *transport; 2324 struct list_head *pos, *temp; 2325 union sctp_params param; 2326 union sctp_addr addr; 2327 struct sctp_af *af; 2328 int src_match = 0; 2329 char *cookie; 2330 2331 /* We must include the address that the INIT packet came from. 2332 * This is the only address that matters for an INIT packet. 2333 * When processing a COOKIE ECHO, we retrieve the from address 2334 * of the INIT from the cookie. 2335 */ 2336 2337 /* This implementation defaults to making the first transport 2338 * added as the primary transport. The source address seems to 2339 * be a a better choice than any of the embedded addresses. 2340 */ 2341 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2342 goto nomem; 2343 2344 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2345 src_match = 1; 2346 2347 /* Process the initialization parameters. */ 2348 sctp_walk_params(param, peer_init, init_hdr.params) { 2349 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2350 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2351 af = sctp_get_af_specific(param_type2af(param.p->type)); 2352 af->from_addr_param(&addr, param.addr, 2353 chunk->sctp_hdr->source, 0); 2354 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2355 src_match = 1; 2356 } 2357 2358 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2359 goto clean_up; 2360 } 2361 2362 /* source address of chunk may not match any valid address */ 2363 if (!src_match) 2364 goto clean_up; 2365 2366 /* AUTH: After processing the parameters, make sure that we 2367 * have all the required info to potentially do authentications. 2368 */ 2369 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2370 !asoc->peer.peer_hmacs)) 2371 asoc->peer.auth_capable = 0; 2372 2373 /* In a non-backward compatible mode, if the peer claims 2374 * support for ADD-IP but not AUTH, the ADD-IP spec states 2375 * that we MUST ABORT the association. Section 6. The section 2376 * also give us an option to silently ignore the packet, which 2377 * is what we'll do here. 2378 */ 2379 if (!net->sctp.addip_noauth && 2380 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2381 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2382 SCTP_PARAM_DEL_IP | 2383 SCTP_PARAM_SET_PRIMARY); 2384 asoc->peer.asconf_capable = 0; 2385 goto clean_up; 2386 } 2387 2388 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2389 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2390 transport = list_entry(pos, struct sctp_transport, transports); 2391 if (transport->state == SCTP_UNKNOWN) { 2392 sctp_assoc_rm_peer(asoc, transport); 2393 } 2394 } 2395 2396 /* The fixed INIT headers are always in network byte 2397 * order. 2398 */ 2399 asoc->peer.i.init_tag = 2400 ntohl(peer_init->init_hdr.init_tag); 2401 asoc->peer.i.a_rwnd = 2402 ntohl(peer_init->init_hdr.a_rwnd); 2403 asoc->peer.i.num_outbound_streams = 2404 ntohs(peer_init->init_hdr.num_outbound_streams); 2405 asoc->peer.i.num_inbound_streams = 2406 ntohs(peer_init->init_hdr.num_inbound_streams); 2407 asoc->peer.i.initial_tsn = 2408 ntohl(peer_init->init_hdr.initial_tsn); 2409 2410 asoc->strreset_inseq = asoc->peer.i.initial_tsn; 2411 2412 /* Apply the upper bounds for output streams based on peer's 2413 * number of inbound streams. 2414 */ 2415 if (asoc->c.sinit_num_ostreams > 2416 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2417 asoc->c.sinit_num_ostreams = 2418 ntohs(peer_init->init_hdr.num_inbound_streams); 2419 } 2420 2421 if (asoc->c.sinit_max_instreams > 2422 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2423 asoc->c.sinit_max_instreams = 2424 ntohs(peer_init->init_hdr.num_outbound_streams); 2425 } 2426 2427 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2428 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2429 2430 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2431 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2432 2433 /* Copy cookie in case we need to resend COOKIE-ECHO. */ 2434 cookie = asoc->peer.cookie; 2435 if (cookie) { 2436 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp); 2437 if (!asoc->peer.cookie) 2438 goto clean_up; 2439 } 2440 2441 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2442 * high (for example, implementations MAY use the size of the receiver 2443 * advertised window). 2444 */ 2445 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2446 transports) { 2447 transport->ssthresh = asoc->peer.i.a_rwnd; 2448 } 2449 2450 /* Set up the TSN tracking pieces. */ 2451 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2452 asoc->peer.i.initial_tsn, gfp)) 2453 goto clean_up; 2454 2455 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2456 * 2457 * The stream sequence number in all the streams shall start 2458 * from 0 when the association is established. Also, when the 2459 * stream sequence number reaches the value 65535 the next 2460 * stream sequence number shall be set to 0. 2461 */ 2462 2463 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams, 2464 asoc->c.sinit_max_instreams, gfp)) 2465 goto clean_up; 2466 2467 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp)) 2468 goto clean_up; 2469 2470 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2471 * 2472 * When an endpoint has an ASCONF signaled change to be sent to the 2473 * remote endpoint it should do the following: 2474 * ... 2475 * A2) A serial number should be assigned to the Chunk. The serial 2476 * number should be a monotonically increasing number. All serial 2477 * numbers are defined to be initialized at the start of the 2478 * association to the same value as the Initial TSN. 2479 */ 2480 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2481 return 1; 2482 2483 clean_up: 2484 /* Release the transport structures. */ 2485 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2486 transport = list_entry(pos, struct sctp_transport, transports); 2487 if (transport->state != SCTP_ACTIVE) 2488 sctp_assoc_rm_peer(asoc, transport); 2489 } 2490 2491 nomem: 2492 return 0; 2493 } 2494 2495 2496 /* Update asoc with the option described in param. 2497 * 2498 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2499 * 2500 * asoc is the association to update. 2501 * param is the variable length parameter to use for update. 2502 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2503 * If the current packet is an INIT we want to minimize the amount of 2504 * work we do. In particular, we should not build transport 2505 * structures for the addresses. 2506 */ 2507 static int sctp_process_param(struct sctp_association *asoc, 2508 union sctp_params param, 2509 const union sctp_addr *peer_addr, 2510 gfp_t gfp) 2511 { 2512 struct net *net = sock_net(asoc->base.sk); 2513 struct sctp_endpoint *ep = asoc->ep; 2514 union sctp_addr_param *addr_param; 2515 struct sctp_transport *t; 2516 enum sctp_scope scope; 2517 union sctp_addr addr; 2518 struct sctp_af *af; 2519 int retval = 1, i; 2520 u32 stale; 2521 __u16 sat; 2522 2523 /* We maintain all INIT parameters in network byte order all the 2524 * time. This allows us to not worry about whether the parameters 2525 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2526 */ 2527 switch (param.p->type) { 2528 case SCTP_PARAM_IPV6_ADDRESS: 2529 if (PF_INET6 != asoc->base.sk->sk_family) 2530 break; 2531 goto do_addr_param; 2532 2533 case SCTP_PARAM_IPV4_ADDRESS: 2534 /* v4 addresses are not allowed on v6-only socket */ 2535 if (ipv6_only_sock(asoc->base.sk)) 2536 break; 2537 do_addr_param: 2538 af = sctp_get_af_specific(param_type2af(param.p->type)); 2539 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); 2540 scope = sctp_scope(peer_addr); 2541 if (sctp_in_scope(net, &addr, scope)) 2542 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2543 return 0; 2544 break; 2545 2546 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2547 if (!net->sctp.cookie_preserve_enable) 2548 break; 2549 2550 stale = ntohl(param.life->lifespan_increment); 2551 2552 /* Suggested Cookie Life span increment's unit is msec, 2553 * (1/1000sec). 2554 */ 2555 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale); 2556 break; 2557 2558 case SCTP_PARAM_HOST_NAME_ADDRESS: 2559 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__); 2560 break; 2561 2562 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2563 /* Turn off the default values first so we'll know which 2564 * ones are really set by the peer. 2565 */ 2566 asoc->peer.ipv4_address = 0; 2567 asoc->peer.ipv6_address = 0; 2568 2569 /* Assume that peer supports the address family 2570 * by which it sends a packet. 2571 */ 2572 if (peer_addr->sa.sa_family == AF_INET6) 2573 asoc->peer.ipv6_address = 1; 2574 else if (peer_addr->sa.sa_family == AF_INET) 2575 asoc->peer.ipv4_address = 1; 2576 2577 /* Cycle through address types; avoid divide by 0. */ 2578 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2579 if (sat) 2580 sat /= sizeof(__u16); 2581 2582 for (i = 0; i < sat; ++i) { 2583 switch (param.sat->types[i]) { 2584 case SCTP_PARAM_IPV4_ADDRESS: 2585 asoc->peer.ipv4_address = 1; 2586 break; 2587 2588 case SCTP_PARAM_IPV6_ADDRESS: 2589 if (PF_INET6 == asoc->base.sk->sk_family) 2590 asoc->peer.ipv6_address = 1; 2591 break; 2592 2593 case SCTP_PARAM_HOST_NAME_ADDRESS: 2594 asoc->peer.hostname_address = 1; 2595 break; 2596 2597 default: /* Just ignore anything else. */ 2598 break; 2599 } 2600 } 2601 break; 2602 2603 case SCTP_PARAM_STATE_COOKIE: 2604 asoc->peer.cookie_len = 2605 ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2606 asoc->peer.cookie = param.cookie->body; 2607 break; 2608 2609 case SCTP_PARAM_HEARTBEAT_INFO: 2610 /* Would be odd to receive, but it causes no problems. */ 2611 break; 2612 2613 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2614 /* Rejected during verify stage. */ 2615 break; 2616 2617 case SCTP_PARAM_ECN_CAPABLE: 2618 asoc->peer.ecn_capable = 1; 2619 break; 2620 2621 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2622 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2623 break; 2624 2625 case SCTP_PARAM_SET_PRIMARY: 2626 if (!net->sctp.addip_enable) 2627 goto fall_through; 2628 2629 addr_param = param.v + sizeof(struct sctp_addip_param); 2630 2631 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 2632 if (af == NULL) 2633 break; 2634 2635 af->from_addr_param(&addr, addr_param, 2636 htons(asoc->peer.port), 0); 2637 2638 /* if the address is invalid, we can't process it. 2639 * XXX: see spec for what to do. 2640 */ 2641 if (!af->addr_valid(&addr, NULL, NULL)) 2642 break; 2643 2644 t = sctp_assoc_lookup_paddr(asoc, &addr); 2645 if (!t) 2646 break; 2647 2648 sctp_assoc_set_primary(asoc, t); 2649 break; 2650 2651 case SCTP_PARAM_SUPPORTED_EXT: 2652 sctp_process_ext_param(asoc, param); 2653 break; 2654 2655 case SCTP_PARAM_FWD_TSN_SUPPORT: 2656 if (asoc->prsctp_enable) { 2657 asoc->peer.prsctp_capable = 1; 2658 break; 2659 } 2660 /* Fall Through */ 2661 goto fall_through; 2662 2663 case SCTP_PARAM_RANDOM: 2664 if (!ep->auth_enable) 2665 goto fall_through; 2666 2667 /* Save peer's random parameter */ 2668 asoc->peer.peer_random = kmemdup(param.p, 2669 ntohs(param.p->length), gfp); 2670 if (!asoc->peer.peer_random) { 2671 retval = 0; 2672 break; 2673 } 2674 break; 2675 2676 case SCTP_PARAM_HMAC_ALGO: 2677 if (!ep->auth_enable) 2678 goto fall_through; 2679 2680 /* Save peer's HMAC list */ 2681 asoc->peer.peer_hmacs = kmemdup(param.p, 2682 ntohs(param.p->length), gfp); 2683 if (!asoc->peer.peer_hmacs) { 2684 retval = 0; 2685 break; 2686 } 2687 2688 /* Set the default HMAC the peer requested*/ 2689 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2690 break; 2691 2692 case SCTP_PARAM_CHUNKS: 2693 if (!ep->auth_enable) 2694 goto fall_through; 2695 2696 asoc->peer.peer_chunks = kmemdup(param.p, 2697 ntohs(param.p->length), gfp); 2698 if (!asoc->peer.peer_chunks) 2699 retval = 0; 2700 break; 2701 fall_through: 2702 default: 2703 /* Any unrecognized parameters should have been caught 2704 * and handled by sctp_verify_param() which should be 2705 * called prior to this routine. Simply log the error 2706 * here. 2707 */ 2708 pr_debug("%s: ignoring param:%d for association:%p.\n", 2709 __func__, ntohs(param.p->type), asoc); 2710 break; 2711 } 2712 2713 return retval; 2714 } 2715 2716 /* Select a new verification tag. */ 2717 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2718 { 2719 /* I believe that this random number generator complies with RFC1750. 2720 * A tag of 0 is reserved for special cases (e.g. INIT). 2721 */ 2722 __u32 x; 2723 2724 do { 2725 get_random_bytes(&x, sizeof(__u32)); 2726 } while (x == 0); 2727 2728 return x; 2729 } 2730 2731 /* Select an initial TSN to send during startup. */ 2732 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2733 { 2734 __u32 retval; 2735 2736 get_random_bytes(&retval, sizeof(__u32)); 2737 return retval; 2738 } 2739 2740 /* 2741 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2742 * 0 1 2 3 2743 * 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 2744 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2745 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2746 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2747 * | Serial Number | 2748 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2749 * | Address Parameter | 2750 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2751 * | ASCONF Parameter #1 | 2752 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2753 * \ \ 2754 * / .... / 2755 * \ \ 2756 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2757 * | ASCONF Parameter #N | 2758 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2759 * 2760 * Address Parameter and other parameter will not be wrapped in this function 2761 */ 2762 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2763 union sctp_addr *addr, 2764 int vparam_len) 2765 { 2766 struct sctp_addiphdr asconf; 2767 struct sctp_chunk *retval; 2768 int length = sizeof(asconf) + vparam_len; 2769 union sctp_addr_param addrparam; 2770 int addrlen; 2771 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2772 2773 addrlen = af->to_addr_param(addr, &addrparam); 2774 if (!addrlen) 2775 return NULL; 2776 length += addrlen; 2777 2778 /* Create the chunk. */ 2779 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length, 2780 GFP_ATOMIC); 2781 if (!retval) 2782 return NULL; 2783 2784 asconf.serial = htonl(asoc->addip_serial++); 2785 2786 retval->subh.addip_hdr = 2787 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2788 retval->param_hdr.v = 2789 sctp_addto_chunk(retval, addrlen, &addrparam); 2790 2791 return retval; 2792 } 2793 2794 /* ADDIP 2795 * 3.2.1 Add IP Address 2796 * 0 1 2 3 2797 * 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 2798 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2799 * | Type = 0xC001 | Length = Variable | 2800 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2801 * | ASCONF-Request Correlation ID | 2802 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2803 * | Address Parameter | 2804 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2805 * 2806 * 3.2.2 Delete IP Address 2807 * 0 1 2 3 2808 * 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 2809 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2810 * | Type = 0xC002 | Length = Variable | 2811 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2812 * | ASCONF-Request Correlation ID | 2813 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2814 * | Address Parameter | 2815 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2816 * 2817 */ 2818 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2819 union sctp_addr *laddr, 2820 struct sockaddr *addrs, 2821 int addrcnt, __be16 flags) 2822 { 2823 union sctp_addr_param addr_param; 2824 struct sctp_addip_param param; 2825 int paramlen = sizeof(param); 2826 struct sctp_chunk *retval; 2827 int addr_param_len = 0; 2828 union sctp_addr *addr; 2829 int totallen = 0, i; 2830 int del_pickup = 0; 2831 struct sctp_af *af; 2832 void *addr_buf; 2833 2834 /* Get total length of all the address parameters. */ 2835 addr_buf = addrs; 2836 for (i = 0; i < addrcnt; i++) { 2837 addr = addr_buf; 2838 af = sctp_get_af_specific(addr->v4.sin_family); 2839 addr_param_len = af->to_addr_param(addr, &addr_param); 2840 2841 totallen += paramlen; 2842 totallen += addr_param_len; 2843 2844 addr_buf += af->sockaddr_len; 2845 if (asoc->asconf_addr_del_pending && !del_pickup) { 2846 /* reuse the parameter length from the same scope one */ 2847 totallen += paramlen; 2848 totallen += addr_param_len; 2849 del_pickup = 1; 2850 2851 pr_debug("%s: picked same-scope del_pending addr, " 2852 "totallen for all addresses is %d\n", 2853 __func__, totallen); 2854 } 2855 } 2856 2857 /* Create an asconf chunk with the required length. */ 2858 retval = sctp_make_asconf(asoc, laddr, totallen); 2859 if (!retval) 2860 return NULL; 2861 2862 /* Add the address parameters to the asconf chunk. */ 2863 addr_buf = addrs; 2864 for (i = 0; i < addrcnt; i++) { 2865 addr = addr_buf; 2866 af = sctp_get_af_specific(addr->v4.sin_family); 2867 addr_param_len = af->to_addr_param(addr, &addr_param); 2868 param.param_hdr.type = flags; 2869 param.param_hdr.length = htons(paramlen + addr_param_len); 2870 param.crr_id = htonl(i); 2871 2872 sctp_addto_chunk(retval, paramlen, ¶m); 2873 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2874 2875 addr_buf += af->sockaddr_len; 2876 } 2877 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2878 addr = asoc->asconf_addr_del_pending; 2879 af = sctp_get_af_specific(addr->v4.sin_family); 2880 addr_param_len = af->to_addr_param(addr, &addr_param); 2881 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2882 param.param_hdr.length = htons(paramlen + addr_param_len); 2883 param.crr_id = htonl(i); 2884 2885 sctp_addto_chunk(retval, paramlen, ¶m); 2886 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2887 } 2888 return retval; 2889 } 2890 2891 /* ADDIP 2892 * 3.2.4 Set Primary IP Address 2893 * 0 1 2 3 2894 * 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 2895 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2896 * | Type =0xC004 | Length = Variable | 2897 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2898 * | ASCONF-Request Correlation ID | 2899 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2900 * | Address Parameter | 2901 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2902 * 2903 * Create an ASCONF chunk with Set Primary IP address parameter. 2904 */ 2905 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2906 union sctp_addr *addr) 2907 { 2908 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2909 union sctp_addr_param addrparam; 2910 struct sctp_addip_param param; 2911 struct sctp_chunk *retval; 2912 int len = sizeof(param); 2913 int addrlen; 2914 2915 addrlen = af->to_addr_param(addr, &addrparam); 2916 if (!addrlen) 2917 return NULL; 2918 len += addrlen; 2919 2920 /* Create the chunk and make asconf header. */ 2921 retval = sctp_make_asconf(asoc, addr, len); 2922 if (!retval) 2923 return NULL; 2924 2925 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2926 param.param_hdr.length = htons(len); 2927 param.crr_id = 0; 2928 2929 sctp_addto_chunk(retval, sizeof(param), ¶m); 2930 sctp_addto_chunk(retval, addrlen, &addrparam); 2931 2932 return retval; 2933 } 2934 2935 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2936 * 0 1 2 3 2937 * 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 2938 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2939 * | Type = 0x80 | Chunk Flags | Chunk Length | 2940 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2941 * | Serial Number | 2942 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2943 * | ASCONF Parameter Response#1 | 2944 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2945 * \ \ 2946 * / .... / 2947 * \ \ 2948 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2949 * | ASCONF Parameter Response#N | 2950 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2951 * 2952 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2953 */ 2954 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2955 __u32 serial, int vparam_len) 2956 { 2957 struct sctp_addiphdr asconf; 2958 struct sctp_chunk *retval; 2959 int length = sizeof(asconf) + vparam_len; 2960 2961 /* Create the chunk. */ 2962 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length, 2963 GFP_ATOMIC); 2964 if (!retval) 2965 return NULL; 2966 2967 asconf.serial = htonl(serial); 2968 2969 retval->subh.addip_hdr = 2970 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2971 2972 return retval; 2973 } 2974 2975 /* Add response parameters to an ASCONF_ACK chunk. */ 2976 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2977 __be16 err_code, 2978 struct sctp_addip_param *asconf_param) 2979 { 2980 struct sctp_addip_param ack_param; 2981 struct sctp_errhdr err_param; 2982 int asconf_param_len = 0; 2983 int err_param_len = 0; 2984 __be16 response_type; 2985 2986 if (SCTP_ERROR_NO_ERROR == err_code) { 2987 response_type = SCTP_PARAM_SUCCESS_REPORT; 2988 } else { 2989 response_type = SCTP_PARAM_ERR_CAUSE; 2990 err_param_len = sizeof(err_param); 2991 if (asconf_param) 2992 asconf_param_len = 2993 ntohs(asconf_param->param_hdr.length); 2994 } 2995 2996 /* Add Success Indication or Error Cause Indication parameter. */ 2997 ack_param.param_hdr.type = response_type; 2998 ack_param.param_hdr.length = htons(sizeof(ack_param) + 2999 err_param_len + 3000 asconf_param_len); 3001 ack_param.crr_id = crr_id; 3002 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 3003 3004 if (SCTP_ERROR_NO_ERROR == err_code) 3005 return; 3006 3007 /* Add Error Cause parameter. */ 3008 err_param.cause = err_code; 3009 err_param.length = htons(err_param_len + asconf_param_len); 3010 sctp_addto_chunk(chunk, err_param_len, &err_param); 3011 3012 /* Add the failed TLV copied from ASCONF chunk. */ 3013 if (asconf_param) 3014 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 3015 } 3016 3017 /* Process a asconf parameter. */ 3018 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 3019 struct sctp_chunk *asconf, 3020 struct sctp_addip_param *asconf_param) 3021 { 3022 union sctp_addr_param *addr_param; 3023 struct sctp_transport *peer; 3024 union sctp_addr addr; 3025 struct sctp_af *af; 3026 3027 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3028 3029 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 3030 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 3031 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 3032 return SCTP_ERROR_UNKNOWN_PARAM; 3033 3034 switch (addr_param->p.type) { 3035 case SCTP_PARAM_IPV6_ADDRESS: 3036 if (!asoc->peer.ipv6_address) 3037 return SCTP_ERROR_DNS_FAILED; 3038 break; 3039 case SCTP_PARAM_IPV4_ADDRESS: 3040 if (!asoc->peer.ipv4_address) 3041 return SCTP_ERROR_DNS_FAILED; 3042 break; 3043 default: 3044 return SCTP_ERROR_DNS_FAILED; 3045 } 3046 3047 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3048 if (unlikely(!af)) 3049 return SCTP_ERROR_DNS_FAILED; 3050 3051 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); 3052 3053 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3054 * or multicast address. 3055 * (note: wildcard is permitted and requires special handling so 3056 * make sure we check for that) 3057 */ 3058 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3059 return SCTP_ERROR_DNS_FAILED; 3060 3061 switch (asconf_param->param_hdr.type) { 3062 case SCTP_PARAM_ADD_IP: 3063 /* Section 4.2.1: 3064 * If the address 0.0.0.0 or ::0 is provided, the source 3065 * address of the packet MUST be added. 3066 */ 3067 if (af->is_any(&addr)) 3068 memcpy(&addr, &asconf->source, sizeof(addr)); 3069 3070 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3071 * request and does not have the local resources to add this 3072 * new address to the association, it MUST return an Error 3073 * Cause TLV set to the new error code 'Operation Refused 3074 * Due to Resource Shortage'. 3075 */ 3076 3077 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3078 if (!peer) 3079 return SCTP_ERROR_RSRC_LOW; 3080 3081 /* Start the heartbeat timer. */ 3082 sctp_transport_reset_hb_timer(peer); 3083 asoc->new_transport = peer; 3084 break; 3085 case SCTP_PARAM_DEL_IP: 3086 /* ADDIP 4.3 D7) If a request is received to delete the 3087 * last remaining IP address of a peer endpoint, the receiver 3088 * MUST send an Error Cause TLV with the error cause set to the 3089 * new error code 'Request to Delete Last Remaining IP Address'. 3090 */ 3091 if (asoc->peer.transport_count == 1) 3092 return SCTP_ERROR_DEL_LAST_IP; 3093 3094 /* ADDIP 4.3 D8) If a request is received to delete an IP 3095 * address which is also the source address of the IP packet 3096 * which contained the ASCONF chunk, the receiver MUST reject 3097 * this request. To reject the request the receiver MUST send 3098 * an Error Cause TLV set to the new error code 'Request to 3099 * Delete Source IP Address' 3100 */ 3101 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3102 return SCTP_ERROR_DEL_SRC_IP; 3103 3104 /* Section 4.2.2 3105 * If the address 0.0.0.0 or ::0 is provided, all 3106 * addresses of the peer except the source address of the 3107 * packet MUST be deleted. 3108 */ 3109 if (af->is_any(&addr)) { 3110 sctp_assoc_set_primary(asoc, asconf->transport); 3111 sctp_assoc_del_nonprimary_peers(asoc, 3112 asconf->transport); 3113 return SCTP_ERROR_NO_ERROR; 3114 } 3115 3116 /* If the address is not part of the association, the 3117 * ASCONF-ACK with Error Cause Indication Parameter 3118 * which including cause of Unresolvable Address should 3119 * be sent. 3120 */ 3121 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3122 if (!peer) 3123 return SCTP_ERROR_DNS_FAILED; 3124 3125 sctp_assoc_rm_peer(asoc, peer); 3126 break; 3127 case SCTP_PARAM_SET_PRIMARY: 3128 /* ADDIP Section 4.2.4 3129 * If the address 0.0.0.0 or ::0 is provided, the receiver 3130 * MAY mark the source address of the packet as its 3131 * primary. 3132 */ 3133 if (af->is_any(&addr)) 3134 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr)); 3135 3136 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3137 if (!peer) 3138 return SCTP_ERROR_DNS_FAILED; 3139 3140 sctp_assoc_set_primary(asoc, peer); 3141 break; 3142 } 3143 3144 return SCTP_ERROR_NO_ERROR; 3145 } 3146 3147 /* Verify the ASCONF packet before we process it. */ 3148 bool sctp_verify_asconf(const struct sctp_association *asoc, 3149 struct sctp_chunk *chunk, bool addr_param_needed, 3150 struct sctp_paramhdr **errp) 3151 { 3152 struct sctp_addip_chunk *addip; 3153 bool addr_param_seen = false; 3154 union sctp_params param; 3155 3156 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr; 3157 sctp_walk_params(param, addip, addip_hdr.params) { 3158 size_t length = ntohs(param.p->length); 3159 3160 *errp = param.p; 3161 switch (param.p->type) { 3162 case SCTP_PARAM_ERR_CAUSE: 3163 break; 3164 case SCTP_PARAM_IPV4_ADDRESS: 3165 if (length != sizeof(struct sctp_ipv4addr_param)) 3166 return false; 3167 /* ensure there is only one addr param and it's in the 3168 * beginning of addip_hdr params, or we reject it. 3169 */ 3170 if (param.v != addip->addip_hdr.params) 3171 return false; 3172 addr_param_seen = true; 3173 break; 3174 case SCTP_PARAM_IPV6_ADDRESS: 3175 if (length != sizeof(struct sctp_ipv6addr_param)) 3176 return false; 3177 if (param.v != addip->addip_hdr.params) 3178 return false; 3179 addr_param_seen = true; 3180 break; 3181 case SCTP_PARAM_ADD_IP: 3182 case SCTP_PARAM_DEL_IP: 3183 case SCTP_PARAM_SET_PRIMARY: 3184 /* In ASCONF chunks, these need to be first. */ 3185 if (addr_param_needed && !addr_param_seen) 3186 return false; 3187 length = ntohs(param.addip->param_hdr.length); 3188 if (length < sizeof(struct sctp_addip_param) + 3189 sizeof(**errp)) 3190 return false; 3191 break; 3192 case SCTP_PARAM_SUCCESS_REPORT: 3193 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3194 if (length != sizeof(struct sctp_addip_param)) 3195 return false; 3196 break; 3197 default: 3198 /* This is unkown to us, reject! */ 3199 return false; 3200 } 3201 } 3202 3203 /* Remaining sanity checks. */ 3204 if (addr_param_needed && !addr_param_seen) 3205 return false; 3206 if (!addr_param_needed && addr_param_seen) 3207 return false; 3208 if (param.v != chunk->chunk_end) 3209 return false; 3210 3211 return true; 3212 } 3213 3214 /* Process an incoming ASCONF chunk with the next expected serial no. and 3215 * return an ASCONF_ACK chunk to be sent in response. 3216 */ 3217 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3218 struct sctp_chunk *asconf) 3219 { 3220 union sctp_addr_param *addr_param; 3221 struct sctp_addip_chunk *addip; 3222 struct sctp_chunk *asconf_ack; 3223 bool all_param_pass = true; 3224 struct sctp_addiphdr *hdr; 3225 int length = 0, chunk_len; 3226 union sctp_params param; 3227 __be16 err_code; 3228 __u32 serial; 3229 3230 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr; 3231 chunk_len = ntohs(asconf->chunk_hdr->length) - 3232 sizeof(struct sctp_chunkhdr); 3233 hdr = (struct sctp_addiphdr *)asconf->skb->data; 3234 serial = ntohl(hdr->serial); 3235 3236 /* Skip the addiphdr and store a pointer to address parameter. */ 3237 length = sizeof(*hdr); 3238 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3239 chunk_len -= length; 3240 3241 /* Skip the address parameter and store a pointer to the first 3242 * asconf parameter. 3243 */ 3244 length = ntohs(addr_param->p.length); 3245 chunk_len -= length; 3246 3247 /* create an ASCONF_ACK chunk. 3248 * Based on the definitions of parameters, we know that the size of 3249 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3250 * parameters. 3251 */ 3252 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3253 if (!asconf_ack) 3254 goto done; 3255 3256 /* Process the TLVs contained within the ASCONF chunk. */ 3257 sctp_walk_params(param, addip, addip_hdr.params) { 3258 /* Skip preceeding address parameters. */ 3259 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 3260 param.p->type == SCTP_PARAM_IPV6_ADDRESS) 3261 continue; 3262 3263 err_code = sctp_process_asconf_param(asoc, asconf, 3264 param.addip); 3265 /* ADDIP 4.1 A7) 3266 * If an error response is received for a TLV parameter, 3267 * all TLVs with no response before the failed TLV are 3268 * considered successful if not reported. All TLVs after 3269 * the failed response are considered unsuccessful unless 3270 * a specific success indication is present for the parameter. 3271 */ 3272 if (err_code != SCTP_ERROR_NO_ERROR) 3273 all_param_pass = false; 3274 if (!all_param_pass) 3275 sctp_add_asconf_response(asconf_ack, param.addip->crr_id, 3276 err_code, param.addip); 3277 3278 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3279 * an IP address sends an 'Out of Resource' in its response, it 3280 * MUST also fail any subsequent add or delete requests bundled 3281 * in the ASCONF. 3282 */ 3283 if (err_code == SCTP_ERROR_RSRC_LOW) 3284 goto done; 3285 } 3286 done: 3287 asoc->peer.addip_serial++; 3288 3289 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3290 * after freeing the reference to old asconf ack if any. 3291 */ 3292 if (asconf_ack) { 3293 sctp_chunk_hold(asconf_ack); 3294 list_add_tail(&asconf_ack->transmitted_list, 3295 &asoc->asconf_ack_list); 3296 } 3297 3298 return asconf_ack; 3299 } 3300 3301 /* Process a asconf parameter that is successfully acked. */ 3302 static void sctp_asconf_param_success(struct sctp_association *asoc, 3303 struct sctp_addip_param *asconf_param) 3304 { 3305 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3306 union sctp_addr_param *addr_param; 3307 struct sctp_sockaddr_entry *saddr; 3308 struct sctp_transport *transport; 3309 union sctp_addr addr; 3310 struct sctp_af *af; 3311 3312 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3313 3314 /* We have checked the packet before, so we do not check again. */ 3315 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3316 af->from_addr_param(&addr, addr_param, htons(bp->port), 0); 3317 3318 switch (asconf_param->param_hdr.type) { 3319 case SCTP_PARAM_ADD_IP: 3320 /* This is always done in BH context with a socket lock 3321 * held, so the list can not change. 3322 */ 3323 local_bh_disable(); 3324 list_for_each_entry(saddr, &bp->address_list, list) { 3325 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3326 saddr->state = SCTP_ADDR_SRC; 3327 } 3328 local_bh_enable(); 3329 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3330 transports) { 3331 sctp_transport_dst_release(transport); 3332 } 3333 break; 3334 case SCTP_PARAM_DEL_IP: 3335 local_bh_disable(); 3336 sctp_del_bind_addr(bp, &addr); 3337 if (asoc->asconf_addr_del_pending != NULL && 3338 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3339 kfree(asoc->asconf_addr_del_pending); 3340 asoc->asconf_addr_del_pending = NULL; 3341 } 3342 local_bh_enable(); 3343 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3344 transports) { 3345 sctp_transport_dst_release(transport); 3346 } 3347 break; 3348 default: 3349 break; 3350 } 3351 } 3352 3353 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3354 * for the given asconf parameter. If there is no response for this parameter, 3355 * return the error code based on the third argument 'no_err'. 3356 * ADDIP 4.1 3357 * A7) If an error response is received for a TLV parameter, all TLVs with no 3358 * response before the failed TLV are considered successful if not reported. 3359 * All TLVs after the failed response are considered unsuccessful unless a 3360 * specific success indication is present for the parameter. 3361 */ 3362 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3363 struct sctp_addip_param *asconf_param, 3364 int no_err) 3365 { 3366 struct sctp_addip_param *asconf_ack_param; 3367 struct sctp_errhdr *err_param; 3368 int asconf_ack_len; 3369 __be16 err_code; 3370 int length; 3371 3372 if (no_err) 3373 err_code = SCTP_ERROR_NO_ERROR; 3374 else 3375 err_code = SCTP_ERROR_REQ_REFUSED; 3376 3377 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3378 sizeof(struct sctp_chunkhdr); 3379 3380 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3381 * the first asconf_ack parameter. 3382 */ 3383 length = sizeof(struct sctp_addiphdr); 3384 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data + 3385 length); 3386 asconf_ack_len -= length; 3387 3388 while (asconf_ack_len > 0) { 3389 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3390 switch (asconf_ack_param->param_hdr.type) { 3391 case SCTP_PARAM_SUCCESS_REPORT: 3392 return SCTP_ERROR_NO_ERROR; 3393 case SCTP_PARAM_ERR_CAUSE: 3394 length = sizeof(*asconf_ack_param); 3395 err_param = (void *)asconf_ack_param + length; 3396 asconf_ack_len -= length; 3397 if (asconf_ack_len > 0) 3398 return err_param->cause; 3399 else 3400 return SCTP_ERROR_INV_PARAM; 3401 break; 3402 default: 3403 return SCTP_ERROR_INV_PARAM; 3404 } 3405 } 3406 3407 length = ntohs(asconf_ack_param->param_hdr.length); 3408 asconf_ack_param = (void *)asconf_ack_param + length; 3409 asconf_ack_len -= length; 3410 } 3411 3412 return err_code; 3413 } 3414 3415 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3416 int sctp_process_asconf_ack(struct sctp_association *asoc, 3417 struct sctp_chunk *asconf_ack) 3418 { 3419 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3420 struct sctp_addip_param *asconf_param; 3421 __be16 err_code = SCTP_ERROR_NO_ERROR; 3422 union sctp_addr_param *addr_param; 3423 int asconf_len = asconf->skb->len; 3424 int all_param_pass = 0; 3425 int length = 0; 3426 int no_err = 1; 3427 int retval = 0; 3428 3429 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3430 * a pointer to address parameter. 3431 */ 3432 length = sizeof(struct sctp_addip_chunk); 3433 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3434 asconf_len -= length; 3435 3436 /* Skip the address parameter in the last asconf sent and store a 3437 * pointer to the first asconf parameter. 3438 */ 3439 length = ntohs(addr_param->p.length); 3440 asconf_param = (void *)addr_param + length; 3441 asconf_len -= length; 3442 3443 /* ADDIP 4.1 3444 * A8) If there is no response(s) to specific TLV parameter(s), and no 3445 * failures are indicated, then all request(s) are considered 3446 * successful. 3447 */ 3448 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr)) 3449 all_param_pass = 1; 3450 3451 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3452 while (asconf_len > 0) { 3453 if (all_param_pass) 3454 err_code = SCTP_ERROR_NO_ERROR; 3455 else { 3456 err_code = sctp_get_asconf_response(asconf_ack, 3457 asconf_param, 3458 no_err); 3459 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3460 no_err = 0; 3461 } 3462 3463 switch (err_code) { 3464 case SCTP_ERROR_NO_ERROR: 3465 sctp_asconf_param_success(asoc, asconf_param); 3466 break; 3467 3468 case SCTP_ERROR_RSRC_LOW: 3469 retval = 1; 3470 break; 3471 3472 case SCTP_ERROR_UNKNOWN_PARAM: 3473 /* Disable sending this type of asconf parameter in 3474 * future. 3475 */ 3476 asoc->peer.addip_disabled_mask |= 3477 asconf_param->param_hdr.type; 3478 break; 3479 3480 case SCTP_ERROR_REQ_REFUSED: 3481 case SCTP_ERROR_DEL_LAST_IP: 3482 case SCTP_ERROR_DEL_SRC_IP: 3483 default: 3484 break; 3485 } 3486 3487 /* Skip the processed asconf parameter and move to the next 3488 * one. 3489 */ 3490 length = ntohs(asconf_param->param_hdr.length); 3491 asconf_param = (void *)asconf_param + length; 3492 asconf_len -= length; 3493 } 3494 3495 if (no_err && asoc->src_out_of_asoc_ok) { 3496 asoc->src_out_of_asoc_ok = 0; 3497 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3498 } 3499 3500 /* Free the cached last sent asconf chunk. */ 3501 list_del_init(&asconf->transmitted_list); 3502 sctp_chunk_free(asconf); 3503 asoc->addip_last_asconf = NULL; 3504 3505 return retval; 3506 } 3507 3508 /* Make a FWD TSN chunk. */ 3509 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3510 __u32 new_cum_tsn, size_t nstreams, 3511 struct sctp_fwdtsn_skip *skiplist) 3512 { 3513 struct sctp_chunk *retval = NULL; 3514 struct sctp_fwdtsn_hdr ftsn_hdr; 3515 struct sctp_fwdtsn_skip skip; 3516 size_t hint; 3517 int i; 3518 3519 hint = (nstreams + 1) * sizeof(__u32); 3520 3521 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC); 3522 3523 if (!retval) 3524 return NULL; 3525 3526 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3527 retval->subh.fwdtsn_hdr = 3528 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3529 3530 for (i = 0; i < nstreams; i++) { 3531 skip.stream = skiplist[i].stream; 3532 skip.ssn = skiplist[i].ssn; 3533 sctp_addto_chunk(retval, sizeof(skip), &skip); 3534 } 3535 3536 return retval; 3537 } 3538 3539 /* RE-CONFIG 3.1 (RE-CONFIG chunk) 3540 * 0 1 2 3 3541 * 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 3542 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3543 * | Type = 130 | Chunk Flags | Chunk Length | 3544 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3545 * \ \ 3546 * / Re-configuration Parameter / 3547 * \ \ 3548 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3549 * \ \ 3550 * / Re-configuration Parameter (optional) / 3551 * \ \ 3552 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3553 */ 3554 static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc, 3555 int length) 3556 { 3557 struct sctp_reconf_chunk *reconf; 3558 struct sctp_chunk *retval; 3559 3560 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length, 3561 GFP_ATOMIC); 3562 if (!retval) 3563 return NULL; 3564 3565 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr; 3566 retval->param_hdr.v = reconf->params; 3567 3568 return retval; 3569 } 3570 3571 /* RE-CONFIG 4.1 (STREAM OUT RESET) 3572 * 0 1 2 3 3573 * 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 3574 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3575 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N | 3576 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3577 * | Re-configuration Request Sequence Number | 3578 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3579 * | Re-configuration Response Sequence Number | 3580 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3581 * | Sender's Last Assigned TSN | 3582 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3583 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3584 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3585 * / ...... / 3586 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3587 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3588 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3589 * 3590 * RE-CONFIG 4.2 (STREAM IN RESET) 3591 * 0 1 2 3 3592 * 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 3593 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3594 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N | 3595 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3596 * | Re-configuration Request Sequence Number | 3597 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3598 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3599 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3600 * / ...... / 3601 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3602 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3603 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3604 */ 3605 struct sctp_chunk *sctp_make_strreset_req( 3606 const struct sctp_association *asoc, 3607 __u16 stream_num, __be16 *stream_list, 3608 bool out, bool in) 3609 { 3610 __u16 stream_len = stream_num * sizeof(__u16); 3611 struct sctp_strreset_outreq outreq; 3612 struct sctp_strreset_inreq inreq; 3613 struct sctp_chunk *retval; 3614 __u16 outlen, inlen; 3615 3616 outlen = (sizeof(outreq) + stream_len) * out; 3617 inlen = (sizeof(inreq) + stream_len) * in; 3618 3619 retval = sctp_make_reconf(asoc, outlen + inlen); 3620 if (!retval) 3621 return NULL; 3622 3623 if (outlen) { 3624 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST; 3625 outreq.param_hdr.length = htons(outlen); 3626 outreq.request_seq = htonl(asoc->strreset_outseq); 3627 outreq.response_seq = htonl(asoc->strreset_inseq - 1); 3628 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1); 3629 3630 sctp_addto_chunk(retval, sizeof(outreq), &outreq); 3631 3632 if (stream_len) 3633 sctp_addto_chunk(retval, stream_len, stream_list); 3634 } 3635 3636 if (inlen) { 3637 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST; 3638 inreq.param_hdr.length = htons(inlen); 3639 inreq.request_seq = htonl(asoc->strreset_outseq + out); 3640 3641 sctp_addto_chunk(retval, sizeof(inreq), &inreq); 3642 3643 if (stream_len) 3644 sctp_addto_chunk(retval, stream_len, stream_list); 3645 } 3646 3647 return retval; 3648 } 3649 3650 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL) 3651 * 0 1 2 3 3652 * 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 3653 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3654 * | Parameter Type = 15 | Parameter Length = 8 | 3655 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3656 * | Re-configuration Request Sequence Number | 3657 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3658 */ 3659 struct sctp_chunk *sctp_make_strreset_tsnreq( 3660 const struct sctp_association *asoc) 3661 { 3662 struct sctp_strreset_tsnreq tsnreq; 3663 __u16 length = sizeof(tsnreq); 3664 struct sctp_chunk *retval; 3665 3666 retval = sctp_make_reconf(asoc, length); 3667 if (!retval) 3668 return NULL; 3669 3670 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST; 3671 tsnreq.param_hdr.length = htons(length); 3672 tsnreq.request_seq = htonl(asoc->strreset_outseq); 3673 3674 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq); 3675 3676 return retval; 3677 } 3678 3679 /* RE-CONFIG 4.5/4.6 (ADD STREAM) 3680 * 0 1 2 3 3681 * 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 3682 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3683 * | Parameter Type = 17 | Parameter Length = 12 | 3684 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3685 * | Re-configuration Request Sequence Number | 3686 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3687 * | Number of new streams | Reserved | 3688 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3689 */ 3690 struct sctp_chunk *sctp_make_strreset_addstrm( 3691 const struct sctp_association *asoc, 3692 __u16 out, __u16 in) 3693 { 3694 struct sctp_strreset_addstrm addstrm; 3695 __u16 size = sizeof(addstrm); 3696 struct sctp_chunk *retval; 3697 3698 retval = sctp_make_reconf(asoc, (!!out + !!in) * size); 3699 if (!retval) 3700 return NULL; 3701 3702 if (out) { 3703 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS; 3704 addstrm.param_hdr.length = htons(size); 3705 addstrm.number_of_streams = htons(out); 3706 addstrm.request_seq = htonl(asoc->strreset_outseq); 3707 addstrm.reserved = 0; 3708 3709 sctp_addto_chunk(retval, size, &addstrm); 3710 } 3711 3712 if (in) { 3713 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS; 3714 addstrm.param_hdr.length = htons(size); 3715 addstrm.number_of_streams = htons(in); 3716 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out); 3717 addstrm.reserved = 0; 3718 3719 sctp_addto_chunk(retval, size, &addstrm); 3720 } 3721 3722 return retval; 3723 } 3724 3725 /* RE-CONFIG 4.4 (RESP) 3726 * 0 1 2 3 3727 * 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 3728 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3729 * | Parameter Type = 16 | Parameter Length | 3730 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3731 * | Re-configuration Response Sequence Number | 3732 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3733 * | Result | 3734 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3735 */ 3736 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc, 3737 __u32 result, __u32 sn) 3738 { 3739 struct sctp_strreset_resp resp; 3740 __u16 length = sizeof(resp); 3741 struct sctp_chunk *retval; 3742 3743 retval = sctp_make_reconf(asoc, length); 3744 if (!retval) 3745 return NULL; 3746 3747 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3748 resp.param_hdr.length = htons(length); 3749 resp.response_seq = htonl(sn); 3750 resp.result = htonl(result); 3751 3752 sctp_addto_chunk(retval, sizeof(resp), &resp); 3753 3754 return retval; 3755 } 3756 3757 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP) 3758 * 0 1 2 3 3759 * 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 3760 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3761 * | Parameter Type = 16 | Parameter Length | 3762 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3763 * | Re-configuration Response Sequence Number | 3764 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3765 * | Result | 3766 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3767 * | Sender's Next TSN (optional) | 3768 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3769 * | Receiver's Next TSN (optional) | 3770 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3771 */ 3772 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc, 3773 __u32 result, __u32 sn, 3774 __u32 sender_tsn, 3775 __u32 receiver_tsn) 3776 { 3777 struct sctp_strreset_resptsn tsnresp; 3778 __u16 length = sizeof(tsnresp); 3779 struct sctp_chunk *retval; 3780 3781 retval = sctp_make_reconf(asoc, length); 3782 if (!retval) 3783 return NULL; 3784 3785 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3786 tsnresp.param_hdr.length = htons(length); 3787 3788 tsnresp.response_seq = htonl(sn); 3789 tsnresp.result = htonl(result); 3790 tsnresp.senders_next_tsn = htonl(sender_tsn); 3791 tsnresp.receivers_next_tsn = htonl(receiver_tsn); 3792 3793 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp); 3794 3795 return retval; 3796 } 3797 3798 bool sctp_verify_reconf(const struct sctp_association *asoc, 3799 struct sctp_chunk *chunk, 3800 struct sctp_paramhdr **errp) 3801 { 3802 struct sctp_reconf_chunk *hdr; 3803 union sctp_params param; 3804 __be16 last = 0; 3805 __u16 cnt = 0; 3806 3807 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; 3808 sctp_walk_params(param, hdr, params) { 3809 __u16 length = ntohs(param.p->length); 3810 3811 *errp = param.p; 3812 if (cnt++ > 2) 3813 return false; 3814 switch (param.p->type) { 3815 case SCTP_PARAM_RESET_OUT_REQUEST: 3816 if (length < sizeof(struct sctp_strreset_outreq) || 3817 (last && last != SCTP_PARAM_RESET_RESPONSE && 3818 last != SCTP_PARAM_RESET_IN_REQUEST)) 3819 return false; 3820 break; 3821 case SCTP_PARAM_RESET_IN_REQUEST: 3822 if (length < sizeof(struct sctp_strreset_inreq) || 3823 (last && last != SCTP_PARAM_RESET_OUT_REQUEST)) 3824 return false; 3825 break; 3826 case SCTP_PARAM_RESET_RESPONSE: 3827 if ((length != sizeof(struct sctp_strreset_resp) && 3828 length != sizeof(struct sctp_strreset_resptsn)) || 3829 (last && last != SCTP_PARAM_RESET_RESPONSE && 3830 last != SCTP_PARAM_RESET_OUT_REQUEST)) 3831 return false; 3832 break; 3833 case SCTP_PARAM_RESET_TSN_REQUEST: 3834 if (length != 3835 sizeof(struct sctp_strreset_tsnreq) || last) 3836 return false; 3837 break; 3838 case SCTP_PARAM_RESET_ADD_IN_STREAMS: 3839 if (length != sizeof(struct sctp_strreset_addstrm) || 3840 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS)) 3841 return false; 3842 break; 3843 case SCTP_PARAM_RESET_ADD_OUT_STREAMS: 3844 if (length != sizeof(struct sctp_strreset_addstrm) || 3845 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS)) 3846 return false; 3847 break; 3848 default: 3849 return false; 3850 } 3851 3852 last = param.p->type; 3853 } 3854 3855 return true; 3856 } 3857