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