1 /* SCTP kernel implementation 2 * (C) Copyright IBM Corp. 2001, 2004 3 * Copyright (c) 1999-2000 Cisco, Inc. 4 * Copyright (c) 1999-2001 Motorola, Inc. 5 * Copyright (c) 2001-2002 Intel Corp. 6 * 7 * This file is part of the SCTP kernel implementation 8 * 9 * These functions work with the state functions in sctp_sm_statefuns.c 10 * to implement the state operations. These functions implement the 11 * steps which require modifying existing data structures. 12 * 13 * This SCTP implementation is free software; 14 * you can redistribute it and/or modify it under the terms of 15 * the GNU General Public License as published by 16 * the Free Software Foundation; either version 2, or (at your option) 17 * any later version. 18 * 19 * This SCTP implementation is distributed in the hope that it 20 * will be useful, but WITHOUT ANY WARRANTY; without even the implied 21 * ************************ 22 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 23 * See the GNU General Public License for more details. 24 * 25 * You should have received a copy of the GNU General Public License 26 * along with GNU CC; see the file COPYING. If not, see 27 * <http://www.gnu.org/licenses/>. 28 * 29 * Please send any bug reports or fixes you make to the 30 * email address(es): 31 * lksctp developers <linux-sctp@vger.kernel.org> 32 * 33 * Written or modified by: 34 * La Monte H.P. Yarroll <piggy@acm.org> 35 * Karl Knutson <karl@athena.chicago.il.us> 36 * C. Robin <chris@hundredacre.ac.uk> 37 * Jon Grimm <jgrimm@us.ibm.com> 38 * Xingang Guo <xingang.guo@intel.com> 39 * Dajiang Zhang <dajiang.zhang@nokia.com> 40 * Sridhar Samudrala <sri@us.ibm.com> 41 * Daisy Chang <daisyc@us.ibm.com> 42 * Ardelle Fan <ardelle.fan@intel.com> 43 * Kevin Gao <kevin.gao@intel.com> 44 */ 45 46 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 47 48 #include <crypto/hash.h> 49 #include <linux/types.h> 50 #include <linux/kernel.h> 51 #include <linux/ip.h> 52 #include <linux/ipv6.h> 53 #include <linux/net.h> 54 #include <linux/inet.h> 55 #include <linux/scatterlist.h> 56 #include <linux/slab.h> 57 #include <net/sock.h> 58 59 #include <linux/skbuff.h> 60 #include <linux/random.h> /* for get_random_bytes */ 61 #include <net/sctp/sctp.h> 62 #include <net/sctp/sm.h> 63 64 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 65 __u8 type, __u8 flags, int paylen, 66 gfp_t gfp); 67 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 68 __u8 flags, int paylen, gfp_t gfp); 69 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 70 __u8 type, __u8 flags, int paylen, 71 gfp_t gfp); 72 static struct sctp_cookie_param *sctp_pack_cookie( 73 const struct sctp_endpoint *ep, 74 const struct sctp_association *asoc, 75 const struct sctp_chunk *init_chunk, 76 int *cookie_len, 77 const __u8 *raw_addrs, int addrs_len); 78 static int sctp_process_param(struct sctp_association *asoc, 79 union sctp_params param, 80 const union sctp_addr *peer_addr, 81 gfp_t gfp); 82 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 83 const void *data); 84 static void *sctp_addto_chunk_fixed(struct sctp_chunk *, int len, 85 const void *data); 86 87 /* Control chunk destructor */ 88 static void sctp_control_release_owner(struct sk_buff *skb) 89 { 90 /*TODO: do memory release */ 91 } 92 93 static void sctp_control_set_owner_w(struct sctp_chunk *chunk) 94 { 95 struct sctp_association *asoc = chunk->asoc; 96 struct sk_buff *skb = chunk->skb; 97 98 /* TODO: properly account for control chunks. 99 * To do it right we'll need: 100 * 1) endpoint if association isn't known. 101 * 2) proper memory accounting. 102 * 103 * For now don't do anything for now. 104 */ 105 skb->sk = asoc ? asoc->base.sk : NULL; 106 skb->destructor = sctp_control_release_owner; 107 } 108 109 /* What was the inbound interface for this chunk? */ 110 int sctp_chunk_iif(const struct sctp_chunk *chunk) 111 { 112 struct sk_buff *skb = chunk->skb; 113 114 return SCTP_INPUT_CB(skb)->af->skb_iif(skb); 115 } 116 117 /* RFC 2960 3.3.2 Initiation (INIT) (1) 118 * 119 * Note 2: The ECN capable field is reserved for future use of 120 * Explicit Congestion Notification. 121 */ 122 static const struct sctp_paramhdr ecap_param = { 123 SCTP_PARAM_ECN_CAPABLE, 124 cpu_to_be16(sizeof(struct sctp_paramhdr)), 125 }; 126 static const struct sctp_paramhdr prsctp_param = { 127 SCTP_PARAM_FWD_TSN_SUPPORT, 128 cpu_to_be16(sizeof(struct sctp_paramhdr)), 129 }; 130 131 /* A helper to initialize an op error inside a 132 * provided chunk, as most cause codes will be embedded inside an 133 * abort chunk. 134 */ 135 void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, 136 size_t paylen) 137 { 138 struct sctp_errhdr err; 139 __u16 len; 140 141 /* Cause code constants are now defined in network order. */ 142 err.cause = cause_code; 143 len = sizeof(err) + paylen; 144 err.length = htons(len); 145 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(err), &err); 146 } 147 148 /* A helper to initialize an op error inside a 149 * provided chunk, as most cause codes will be embedded inside an 150 * abort chunk. Differs from sctp_init_cause in that it won't oops 151 * if there isn't enough space in the op error chunk 152 */ 153 static int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code, 154 size_t paylen) 155 { 156 struct sctp_errhdr err; 157 __u16 len; 158 159 /* Cause code constants are now defined in network order. */ 160 err.cause = cause_code; 161 len = sizeof(err) + paylen; 162 err.length = htons(len); 163 164 if (skb_tailroom(chunk->skb) < len) 165 return -ENOSPC; 166 167 chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk, sizeof(err), &err); 168 169 return 0; 170 } 171 /* 3.3.2 Initiation (INIT) (1) 172 * 173 * This chunk is used to initiate a SCTP association between two 174 * endpoints. The format of the INIT chunk is shown below: 175 * 176 * 0 1 2 3 177 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 178 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 179 * | Type = 1 | Chunk Flags | Chunk Length | 180 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 181 * | Initiate Tag | 182 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 183 * | Advertised Receiver Window Credit (a_rwnd) | 184 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 185 * | Number of Outbound Streams | Number of Inbound Streams | 186 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 187 * | Initial TSN | 188 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 189 * \ \ 190 * / Optional/Variable-Length Parameters / 191 * \ \ 192 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 193 * 194 * 195 * The INIT chunk contains the following parameters. Unless otherwise 196 * noted, each parameter MUST only be included once in the INIT chunk. 197 * 198 * Fixed Parameters Status 199 * ---------------------------------------------- 200 * Initiate Tag Mandatory 201 * Advertised Receiver Window Credit Mandatory 202 * Number of Outbound Streams Mandatory 203 * Number of Inbound Streams Mandatory 204 * Initial TSN Mandatory 205 * 206 * Variable Parameters Status Type Value 207 * ------------------------------------------------------------- 208 * IPv4 Address (Note 1) Optional 5 209 * IPv6 Address (Note 1) Optional 6 210 * Cookie Preservative Optional 9 211 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000) 212 * Host Name Address (Note 3) Optional 11 213 * Supported Address Types (Note 4) Optional 12 214 */ 215 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc, 216 const struct sctp_bind_addr *bp, 217 gfp_t gfp, int vparam_len) 218 { 219 struct net *net = sock_net(asoc->base.sk); 220 struct sctp_supported_ext_param ext_param; 221 struct sctp_adaptation_ind_param aiparam; 222 struct sctp_paramhdr *auth_chunks = NULL; 223 struct sctp_paramhdr *auth_hmacs = NULL; 224 struct sctp_supported_addrs_param sat; 225 struct sctp_endpoint *ep = asoc->ep; 226 struct sctp_chunk *retval = NULL; 227 int num_types, addrs_len = 0; 228 struct sctp_inithdr init; 229 union sctp_params addrs; 230 struct sctp_sock *sp; 231 __u8 extensions[5]; 232 size_t chunksize; 233 __be16 types[2]; 234 int num_ext = 0; 235 236 /* RFC 2960 3.3.2 Initiation (INIT) (1) 237 * 238 * Note 1: The INIT chunks can contain multiple addresses that 239 * can be IPv4 and/or IPv6 in any combination. 240 */ 241 242 /* Convert the provided bind address list to raw format. */ 243 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp); 244 245 init.init_tag = htonl(asoc->c.my_vtag); 246 init.a_rwnd = htonl(asoc->rwnd); 247 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 248 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 249 init.initial_tsn = htonl(asoc->c.initial_tsn); 250 251 /* How many address types are needed? */ 252 sp = sctp_sk(asoc->base.sk); 253 num_types = sp->pf->supported_addrs(sp, types); 254 255 chunksize = sizeof(init) + addrs_len; 256 chunksize += SCTP_PAD4(SCTP_SAT_LEN(num_types)); 257 chunksize += sizeof(ecap_param); 258 259 if (asoc->prsctp_enable) 260 chunksize += sizeof(prsctp_param); 261 262 /* ADDIP: Section 4.2.7: 263 * An implementation supporting this extension [ADDIP] MUST list 264 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and 265 * INIT-ACK parameters. 266 */ 267 if (net->sctp.addip_enable) { 268 extensions[num_ext] = SCTP_CID_ASCONF; 269 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 270 num_ext += 2; 271 } 272 273 if (asoc->reconf_enable) { 274 extensions[num_ext] = SCTP_CID_RECONF; 275 num_ext += 1; 276 } 277 278 if (sp->adaptation_ind) 279 chunksize += sizeof(aiparam); 280 281 if (sp->strm_interleave) { 282 extensions[num_ext] = SCTP_CID_I_DATA; 283 num_ext += 1; 284 } 285 286 chunksize += vparam_len; 287 288 /* Account for AUTH related parameters */ 289 if (ep->auth_enable) { 290 /* Add random parameter length*/ 291 chunksize += sizeof(asoc->c.auth_random); 292 293 /* Add HMACS parameter length if any were defined */ 294 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; 295 if (auth_hmacs->length) 296 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 297 else 298 auth_hmacs = NULL; 299 300 /* Add CHUNKS parameter length */ 301 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; 302 if (auth_chunks->length) 303 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 304 else 305 auth_chunks = NULL; 306 307 extensions[num_ext] = SCTP_CID_AUTH; 308 num_ext += 1; 309 } 310 311 /* If we have any extensions to report, account for that */ 312 if (num_ext) 313 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext); 314 315 /* RFC 2960 3.3.2 Initiation (INIT) (1) 316 * 317 * Note 3: An INIT chunk MUST NOT contain more than one Host 318 * Name address parameter. Moreover, the sender of the INIT 319 * MUST NOT combine any other address types with the Host Name 320 * address in the INIT. The receiver of INIT MUST ignore any 321 * other address types if the Host Name address parameter is 322 * present in the received INIT chunk. 323 * 324 * PLEASE DO NOT FIXME [This version does not support Host Name.] 325 */ 326 327 retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp); 328 if (!retval) 329 goto nodata; 330 331 retval->subh.init_hdr = 332 sctp_addto_chunk(retval, sizeof(init), &init); 333 retval->param_hdr.v = 334 sctp_addto_chunk(retval, addrs_len, addrs.v); 335 336 /* RFC 2960 3.3.2 Initiation (INIT) (1) 337 * 338 * Note 4: This parameter, when present, specifies all the 339 * address types the sending endpoint can support. The absence 340 * of this parameter indicates that the sending endpoint can 341 * support any address type. 342 */ 343 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES; 344 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types)); 345 sctp_addto_chunk(retval, sizeof(sat), &sat); 346 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types); 347 348 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 349 350 /* Add the supported extensions parameter. Be nice and add this 351 * fist before addiding the parameters for the extensions themselves 352 */ 353 if (num_ext) { 354 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 355 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext); 356 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); 357 sctp_addto_param(retval, num_ext, extensions); 358 } 359 360 if (asoc->prsctp_enable) 361 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 362 363 if (sp->adaptation_ind) { 364 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 365 aiparam.param_hdr.length = htons(sizeof(aiparam)); 366 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 367 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 368 } 369 370 /* Add SCTP-AUTH chunks to the parameter list */ 371 if (ep->auth_enable) { 372 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random), 373 asoc->c.auth_random); 374 if (auth_hmacs) 375 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 376 auth_hmacs); 377 if (auth_chunks) 378 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 379 auth_chunks); 380 } 381 nodata: 382 kfree(addrs.v); 383 return retval; 384 } 385 386 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, 387 const struct sctp_chunk *chunk, 388 gfp_t gfp, int unkparam_len) 389 { 390 struct sctp_supported_ext_param ext_param; 391 struct sctp_adaptation_ind_param aiparam; 392 struct sctp_paramhdr *auth_chunks = NULL; 393 struct sctp_paramhdr *auth_random = NULL; 394 struct sctp_paramhdr *auth_hmacs = NULL; 395 struct sctp_chunk *retval = NULL; 396 struct sctp_cookie_param *cookie; 397 struct sctp_inithdr initack; 398 union sctp_params addrs; 399 struct sctp_sock *sp; 400 __u8 extensions[5]; 401 size_t chunksize; 402 int num_ext = 0; 403 int cookie_len; 404 int addrs_len; 405 406 /* Note: there may be no addresses to embed. */ 407 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp); 408 409 initack.init_tag = htonl(asoc->c.my_vtag); 410 initack.a_rwnd = htonl(asoc->rwnd); 411 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 412 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 413 initack.initial_tsn = htonl(asoc->c.initial_tsn); 414 415 /* FIXME: We really ought to build the cookie right 416 * into the packet instead of allocating more fresh memory. 417 */ 418 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len, 419 addrs.v, addrs_len); 420 if (!cookie) 421 goto nomem_cookie; 422 423 /* Calculate the total size of allocation, include the reserved 424 * space for reporting unknown parameters if it is specified. 425 */ 426 sp = sctp_sk(asoc->base.sk); 427 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len; 428 429 /* Tell peer that we'll do ECN only if peer advertised such cap. */ 430 if (asoc->peer.ecn_capable) 431 chunksize += sizeof(ecap_param); 432 433 if (asoc->peer.prsctp_capable) 434 chunksize += sizeof(prsctp_param); 435 436 if (asoc->peer.asconf_capable) { 437 extensions[num_ext] = SCTP_CID_ASCONF; 438 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 439 num_ext += 2; 440 } 441 442 if (asoc->peer.reconf_capable) { 443 extensions[num_ext] = SCTP_CID_RECONF; 444 num_ext += 1; 445 } 446 447 if (sp->adaptation_ind) 448 chunksize += sizeof(aiparam); 449 450 if (asoc->intl_enable) { 451 extensions[num_ext] = SCTP_CID_I_DATA; 452 num_ext += 1; 453 } 454 455 if (asoc->peer.auth_capable) { 456 auth_random = (struct sctp_paramhdr *)asoc->c.auth_random; 457 chunksize += ntohs(auth_random->length); 458 459 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; 460 if (auth_hmacs->length) 461 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 462 else 463 auth_hmacs = NULL; 464 465 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; 466 if (auth_chunks->length) 467 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 468 else 469 auth_chunks = NULL; 470 471 extensions[num_ext] = SCTP_CID_AUTH; 472 num_ext += 1; 473 } 474 475 if (num_ext) 476 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext); 477 478 /* Now allocate and fill out the chunk. */ 479 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp); 480 if (!retval) 481 goto nomem_chunk; 482 483 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 484 * 485 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 486 * HEARTBEAT ACK, * etc.) to the same destination transport 487 * address from which it received the DATA or control chunk 488 * to which it is replying. 489 * 490 * [INIT ACK back to where the INIT came from.] 491 */ 492 retval->transport = chunk->transport; 493 494 retval->subh.init_hdr = 495 sctp_addto_chunk(retval, sizeof(initack), &initack); 496 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); 497 sctp_addto_chunk(retval, cookie_len, cookie); 498 if (asoc->peer.ecn_capable) 499 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 500 if (num_ext) { 501 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 502 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext); 503 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); 504 sctp_addto_param(retval, num_ext, extensions); 505 } 506 if (asoc->peer.prsctp_capable) 507 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 508 509 if (sp->adaptation_ind) { 510 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 511 aiparam.param_hdr.length = htons(sizeof(aiparam)); 512 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 513 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 514 } 515 516 if (asoc->peer.auth_capable) { 517 sctp_addto_chunk(retval, ntohs(auth_random->length), 518 auth_random); 519 if (auth_hmacs) 520 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 521 auth_hmacs); 522 if (auth_chunks) 523 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 524 auth_chunks); 525 } 526 527 /* We need to remove the const qualifier at this point. */ 528 retval->asoc = (struct sctp_association *) asoc; 529 530 nomem_chunk: 531 kfree(cookie); 532 nomem_cookie: 533 kfree(addrs.v); 534 return retval; 535 } 536 537 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10): 538 * 539 * This chunk is used only during the initialization of an association. 540 * It is sent by the initiator of an association to its peer to complete 541 * the initialization process. This chunk MUST precede any DATA chunk 542 * sent within the association, but MAY be bundled with one or more DATA 543 * chunks in the same packet. 544 * 545 * 0 1 2 3 546 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 547 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 548 * | Type = 10 |Chunk Flags | Length | 549 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 550 * / Cookie / 551 * \ \ 552 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 553 * 554 * Chunk Flags: 8 bit 555 * 556 * Set to zero on transmit and ignored on receipt. 557 * 558 * Length: 16 bits (unsigned integer) 559 * 560 * Set to the size of the chunk in bytes, including the 4 bytes of 561 * the chunk header and the size of the Cookie. 562 * 563 * Cookie: variable size 564 * 565 * This field must contain the exact cookie received in the 566 * State Cookie parameter from the previous INIT ACK. 567 * 568 * An implementation SHOULD make the cookie as small as possible 569 * to insure interoperability. 570 */ 571 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, 572 const struct sctp_chunk *chunk) 573 { 574 struct sctp_chunk *retval; 575 int cookie_len; 576 void *cookie; 577 578 cookie = asoc->peer.cookie; 579 cookie_len = asoc->peer.cookie_len; 580 581 /* Build a cookie echo chunk. */ 582 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0, 583 cookie_len, GFP_ATOMIC); 584 if (!retval) 585 goto nodata; 586 retval->subh.cookie_hdr = 587 sctp_addto_chunk(retval, cookie_len, cookie); 588 589 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 590 * 591 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 592 * HEARTBEAT ACK, * etc.) to the same destination transport 593 * address from which it * received the DATA or control chunk 594 * to which it is replying. 595 * 596 * [COOKIE ECHO back to where the INIT ACK came from.] 597 */ 598 if (chunk) 599 retval->transport = chunk->transport; 600 601 nodata: 602 return retval; 603 } 604 605 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11): 606 * 607 * This chunk is used only during the initialization of an 608 * association. It is used to acknowledge the receipt of a COOKIE 609 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent 610 * within the association, but MAY be bundled with one or more DATA 611 * chunks or SACK chunk in the same SCTP packet. 612 * 613 * 0 1 2 3 614 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 615 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 616 * | Type = 11 |Chunk Flags | Length = 4 | 617 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 618 * 619 * Chunk Flags: 8 bits 620 * 621 * Set to zero on transmit and ignored on receipt. 622 */ 623 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, 624 const struct sctp_chunk *chunk) 625 { 626 struct sctp_chunk *retval; 627 628 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC); 629 630 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 631 * 632 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 633 * HEARTBEAT ACK, * etc.) to the same destination transport 634 * address from which it * received the DATA or control chunk 635 * to which it is replying. 636 * 637 * [COOKIE ACK back to where the COOKIE ECHO came from.] 638 */ 639 if (retval && chunk) 640 retval->transport = chunk->transport; 641 642 return retval; 643 } 644 645 /* 646 * Appendix A: Explicit Congestion Notification: 647 * CWR: 648 * 649 * RFC 2481 details a specific bit for a sender to send in the header of 650 * its next outbound TCP segment to indicate to its peer that it has 651 * reduced its congestion window. This is termed the CWR bit. For 652 * SCTP the same indication is made by including the CWR chunk. 653 * This chunk contains one data element, i.e. the TSN number that 654 * was sent in the ECNE chunk. This element represents the lowest 655 * TSN number in the datagram that was originally marked with the 656 * CE bit. 657 * 658 * 0 1 2 3 659 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 660 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 661 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 | 662 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 663 * | Lowest TSN Number | 664 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 665 * 666 * Note: The CWR is considered a Control chunk. 667 */ 668 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, 669 const __u32 lowest_tsn, 670 const struct sctp_chunk *chunk) 671 { 672 struct sctp_chunk *retval; 673 struct sctp_cwrhdr cwr; 674 675 cwr.lowest_tsn = htonl(lowest_tsn); 676 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0, 677 sizeof(cwr), GFP_ATOMIC); 678 679 if (!retval) 680 goto nodata; 681 682 retval->subh.ecn_cwr_hdr = 683 sctp_addto_chunk(retval, sizeof(cwr), &cwr); 684 685 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 686 * 687 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 688 * HEARTBEAT ACK, * etc.) to the same destination transport 689 * address from which it * received the DATA or control chunk 690 * to which it is replying. 691 * 692 * [Report a reduced congestion window back to where the ECNE 693 * came from.] 694 */ 695 if (chunk) 696 retval->transport = chunk->transport; 697 698 nodata: 699 return retval; 700 } 701 702 /* Make an ECNE chunk. This is a congestion experienced report. */ 703 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, 704 const __u32 lowest_tsn) 705 { 706 struct sctp_chunk *retval; 707 struct sctp_ecnehdr ecne; 708 709 ecne.lowest_tsn = htonl(lowest_tsn); 710 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0, 711 sizeof(ecne), GFP_ATOMIC); 712 if (!retval) 713 goto nodata; 714 retval->subh.ecne_hdr = 715 sctp_addto_chunk(retval, sizeof(ecne), &ecne); 716 717 nodata: 718 return retval; 719 } 720 721 /* Make a DATA chunk for the given association from the provided 722 * parameters. However, do not populate the data payload. 723 */ 724 struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc, 725 const struct sctp_sndrcvinfo *sinfo, 726 int len, __u8 flags, gfp_t gfp) 727 { 728 struct sctp_chunk *retval; 729 struct sctp_datahdr dp; 730 731 /* We assign the TSN as LATE as possible, not here when 732 * creating the chunk. 733 */ 734 memset(&dp, 0, sizeof(dp)); 735 dp.ppid = sinfo->sinfo_ppid; 736 dp.stream = htons(sinfo->sinfo_stream); 737 738 /* Set the flags for an unordered send. */ 739 if (sinfo->sinfo_flags & SCTP_UNORDERED) 740 flags |= SCTP_DATA_UNORDERED; 741 742 retval = sctp_make_data(asoc, flags, sizeof(dp) + len, gfp); 743 if (!retval) 744 return NULL; 745 746 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp); 747 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo)); 748 749 return retval; 750 } 751 752 /* Create a selective ackowledgement (SACK) for the given 753 * association. This reports on which TSN's we've seen to date, 754 * including duplicates and gaps. 755 */ 756 struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc) 757 { 758 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; 759 struct sctp_association *aptr = (struct sctp_association *)asoc; 760 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; 761 __u16 num_gabs, num_dup_tsns; 762 struct sctp_transport *trans; 763 struct sctp_chunk *retval; 764 struct sctp_sackhdr sack; 765 __u32 ctsn; 766 int len; 767 768 memset(gabs, 0, sizeof(gabs)); 769 ctsn = sctp_tsnmap_get_ctsn(map); 770 771 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn); 772 773 /* How much room is needed in the chunk? */ 774 num_gabs = sctp_tsnmap_num_gabs(map, gabs); 775 num_dup_tsns = sctp_tsnmap_num_dups(map); 776 777 /* Initialize the SACK header. */ 778 sack.cum_tsn_ack = htonl(ctsn); 779 sack.a_rwnd = htonl(asoc->a_rwnd); 780 sack.num_gap_ack_blocks = htons(num_gabs); 781 sack.num_dup_tsns = htons(num_dup_tsns); 782 783 len = sizeof(sack) 784 + sizeof(struct sctp_gap_ack_block) * num_gabs 785 + sizeof(__u32) * num_dup_tsns; 786 787 /* Create the chunk. */ 788 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC); 789 if (!retval) 790 goto nodata; 791 792 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 793 * 794 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 795 * HEARTBEAT ACK, etc.) to the same destination transport 796 * address from which it received the DATA or control chunk to 797 * which it is replying. This rule should also be followed if 798 * the endpoint is bundling DATA chunks together with the 799 * reply chunk. 800 * 801 * However, when acknowledging multiple DATA chunks received 802 * in packets from different source addresses in a single 803 * SACK, the SACK chunk may be transmitted to one of the 804 * destination transport addresses from which the DATA or 805 * control chunks being acknowledged were received. 806 * 807 * [BUG: We do not implement the following paragraph. 808 * Perhaps we should remember the last transport we used for a 809 * SACK and avoid that (if possible) if we have seen any 810 * duplicates. --piggy] 811 * 812 * When a receiver of a duplicate DATA chunk sends a SACK to a 813 * multi- homed endpoint it MAY be beneficial to vary the 814 * destination address and not use the source address of the 815 * DATA chunk. The reason being that receiving a duplicate 816 * from a multi-homed endpoint might indicate that the return 817 * path (as specified in the source address of the DATA chunk) 818 * for the SACK is broken. 819 * 820 * [Send to the address from which we last received a DATA chunk.] 821 */ 822 retval->transport = asoc->peer.last_data_from; 823 824 retval->subh.sack_hdr = 825 sctp_addto_chunk(retval, sizeof(sack), &sack); 826 827 /* Add the gap ack block information. */ 828 if (num_gabs) 829 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, 830 gabs); 831 832 /* Add the duplicate TSN information. */ 833 if (num_dup_tsns) { 834 aptr->stats.idupchunks += num_dup_tsns; 835 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, 836 sctp_tsnmap_get_dups(map)); 837 } 838 /* Once we have a sack generated, check to see what our sack 839 * generation is, if its 0, reset the transports to 0, and reset 840 * the association generation to 1 841 * 842 * The idea is that zero is never used as a valid generation for the 843 * association so no transport will match after a wrap event like this, 844 * Until the next sack 845 */ 846 if (++aptr->peer.sack_generation == 0) { 847 list_for_each_entry(trans, &asoc->peer.transport_addr_list, 848 transports) 849 trans->sack_generation = 0; 850 aptr->peer.sack_generation = 1; 851 } 852 nodata: 853 return retval; 854 } 855 856 /* Make a SHUTDOWN chunk. */ 857 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 858 const struct sctp_chunk *chunk) 859 { 860 struct sctp_shutdownhdr shut; 861 struct sctp_chunk *retval; 862 __u32 ctsn; 863 864 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 865 shut.cum_tsn_ack = htonl(ctsn); 866 867 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0, 868 sizeof(shut), GFP_ATOMIC); 869 if (!retval) 870 goto nodata; 871 872 retval->subh.shutdown_hdr = 873 sctp_addto_chunk(retval, sizeof(shut), &shut); 874 875 if (chunk) 876 retval->transport = chunk->transport; 877 nodata: 878 return retval; 879 } 880 881 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 882 const struct sctp_chunk *chunk) 883 { 884 struct sctp_chunk *retval; 885 886 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0, 887 GFP_ATOMIC); 888 889 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 890 * 891 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 892 * HEARTBEAT ACK, * etc.) to the same destination transport 893 * address from which it * received the DATA or control chunk 894 * to which it is replying. 895 * 896 * [ACK back to where the SHUTDOWN came from.] 897 */ 898 if (retval && chunk) 899 retval->transport = chunk->transport; 900 901 return retval; 902 } 903 904 struct sctp_chunk *sctp_make_shutdown_complete( 905 const struct sctp_association *asoc, 906 const struct sctp_chunk *chunk) 907 { 908 struct sctp_chunk *retval; 909 __u8 flags = 0; 910 911 /* Set the T-bit if we have no association (vtag will be 912 * reflected) 913 */ 914 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; 915 916 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 917 0, GFP_ATOMIC); 918 919 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 920 * 921 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 922 * HEARTBEAT ACK, * etc.) to the same destination transport 923 * address from which it * received the DATA or control chunk 924 * to which it is replying. 925 * 926 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK 927 * came from.] 928 */ 929 if (retval && chunk) 930 retval->transport = chunk->transport; 931 932 return retval; 933 } 934 935 /* Create an ABORT. Note that we set the T bit if we have no 936 * association, except when responding to an INIT (sctpimpguide 2.41). 937 */ 938 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 939 const struct sctp_chunk *chunk, 940 const size_t hint) 941 { 942 struct sctp_chunk *retval; 943 __u8 flags = 0; 944 945 /* Set the T-bit if we have no association and 'chunk' is not 946 * an INIT (vtag will be reflected). 947 */ 948 if (!asoc) { 949 if (chunk && chunk->chunk_hdr && 950 chunk->chunk_hdr->type == SCTP_CID_INIT) 951 flags = 0; 952 else 953 flags = SCTP_CHUNK_FLAG_T; 954 } 955 956 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint, 957 GFP_ATOMIC); 958 959 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 960 * 961 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 962 * HEARTBEAT ACK, * etc.) to the same destination transport 963 * address from which it * received the DATA or control chunk 964 * to which it is replying. 965 * 966 * [ABORT back to where the offender came from.] 967 */ 968 if (retval && chunk) 969 retval->transport = chunk->transport; 970 971 return retval; 972 } 973 974 /* Helper to create ABORT with a NO_USER_DATA error. */ 975 struct sctp_chunk *sctp_make_abort_no_data( 976 const struct sctp_association *asoc, 977 const struct sctp_chunk *chunk, 978 __u32 tsn) 979 { 980 struct sctp_chunk *retval; 981 __be32 payload; 982 983 retval = sctp_make_abort(asoc, chunk, 984 sizeof(struct sctp_errhdr) + sizeof(tsn)); 985 986 if (!retval) 987 goto no_mem; 988 989 /* Put the tsn back into network byte order. */ 990 payload = htonl(tsn); 991 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload)); 992 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload); 993 994 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 995 * 996 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 997 * HEARTBEAT ACK, * etc.) to the same destination transport 998 * address from which it * received the DATA or control chunk 999 * to which it is replying. 1000 * 1001 * [ABORT back to where the offender came from.] 1002 */ 1003 if (chunk) 1004 retval->transport = chunk->transport; 1005 1006 no_mem: 1007 return retval; 1008 } 1009 1010 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ 1011 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 1012 struct msghdr *msg, 1013 size_t paylen) 1014 { 1015 struct sctp_chunk *retval; 1016 void *payload = NULL; 1017 int err; 1018 1019 retval = sctp_make_abort(asoc, NULL, 1020 sizeof(struct sctp_errhdr) + paylen); 1021 if (!retval) 1022 goto err_chunk; 1023 1024 if (paylen) { 1025 /* Put the msg_iov together into payload. */ 1026 payload = kmalloc(paylen, GFP_KERNEL); 1027 if (!payload) 1028 goto err_payload; 1029 1030 err = memcpy_from_msg(payload, msg, paylen); 1031 if (err < 0) 1032 goto err_copy; 1033 } 1034 1035 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); 1036 sctp_addto_chunk(retval, paylen, payload); 1037 1038 if (paylen) 1039 kfree(payload); 1040 1041 return retval; 1042 1043 err_copy: 1044 kfree(payload); 1045 err_payload: 1046 sctp_chunk_free(retval); 1047 retval = NULL; 1048 err_chunk: 1049 return retval; 1050 } 1051 1052 /* Append bytes to the end of a parameter. Will panic if chunk is not big 1053 * enough. 1054 */ 1055 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 1056 const void *data) 1057 { 1058 int chunklen = ntohs(chunk->chunk_hdr->length); 1059 void *target; 1060 1061 target = skb_put(chunk->skb, len); 1062 1063 if (data) 1064 memcpy(target, data, len); 1065 else 1066 memset(target, 0, len); 1067 1068 /* Adjust the chunk length field. */ 1069 chunk->chunk_hdr->length = htons(chunklen + len); 1070 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1071 1072 return target; 1073 } 1074 1075 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ 1076 struct sctp_chunk *sctp_make_abort_violation( 1077 const struct sctp_association *asoc, 1078 const struct sctp_chunk *chunk, 1079 const __u8 *payload, 1080 const size_t paylen) 1081 { 1082 struct sctp_chunk *retval; 1083 struct sctp_paramhdr phdr; 1084 1085 retval = sctp_make_abort(asoc, chunk, sizeof(struct sctp_errhdr) + 1086 paylen + sizeof(phdr)); 1087 if (!retval) 1088 goto end; 1089 1090 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen + 1091 sizeof(phdr)); 1092 1093 phdr.type = htons(chunk->chunk_hdr->type); 1094 phdr.length = chunk->chunk_hdr->length; 1095 sctp_addto_chunk(retval, paylen, payload); 1096 sctp_addto_param(retval, sizeof(phdr), &phdr); 1097 1098 end: 1099 return retval; 1100 } 1101 1102 struct sctp_chunk *sctp_make_violation_paramlen( 1103 const struct sctp_association *asoc, 1104 const struct sctp_chunk *chunk, 1105 struct sctp_paramhdr *param) 1106 { 1107 static const char error[] = "The following parameter had invalid length:"; 1108 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr) + 1109 sizeof(*param); 1110 struct sctp_chunk *retval; 1111 1112 retval = sctp_make_abort(asoc, chunk, payload_len); 1113 if (!retval) 1114 goto nodata; 1115 1116 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, 1117 sizeof(error) + sizeof(*param)); 1118 sctp_addto_chunk(retval, sizeof(error), error); 1119 sctp_addto_param(retval, sizeof(*param), param); 1120 1121 nodata: 1122 return retval; 1123 } 1124 1125 struct sctp_chunk *sctp_make_violation_max_retrans( 1126 const struct sctp_association *asoc, 1127 const struct sctp_chunk *chunk) 1128 { 1129 static const char error[] = "Association exceeded its max_retans count"; 1130 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr); 1131 struct sctp_chunk *retval; 1132 1133 retval = sctp_make_abort(asoc, chunk, payload_len); 1134 if (!retval) 1135 goto nodata; 1136 1137 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error)); 1138 sctp_addto_chunk(retval, sizeof(error), error); 1139 1140 nodata: 1141 return retval; 1142 } 1143 1144 /* Make a HEARTBEAT chunk. */ 1145 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1146 const struct sctp_transport *transport) 1147 { 1148 struct sctp_sender_hb_info hbinfo; 1149 struct sctp_chunk *retval; 1150 1151 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, 1152 sizeof(hbinfo), GFP_ATOMIC); 1153 1154 if (!retval) 1155 goto nodata; 1156 1157 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; 1158 hbinfo.param_hdr.length = htons(sizeof(hbinfo)); 1159 hbinfo.daddr = transport->ipaddr; 1160 hbinfo.sent_at = jiffies; 1161 hbinfo.hb_nonce = transport->hb_nonce; 1162 1163 /* Cast away the 'const', as this is just telling the chunk 1164 * what transport it belongs to. 1165 */ 1166 retval->transport = (struct sctp_transport *) transport; 1167 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo), 1168 &hbinfo); 1169 1170 nodata: 1171 return retval; 1172 } 1173 1174 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1175 const struct sctp_chunk *chunk, 1176 const void *payload, 1177 const size_t paylen) 1178 { 1179 struct sctp_chunk *retval; 1180 1181 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen, 1182 GFP_ATOMIC); 1183 if (!retval) 1184 goto nodata; 1185 1186 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1187 1188 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1189 * 1190 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1191 * HEARTBEAT ACK, * etc.) to the same destination transport 1192 * address from which it * received the DATA or control chunk 1193 * to which it is replying. 1194 * 1195 * [HBACK back to where the HEARTBEAT came from.] 1196 */ 1197 if (chunk) 1198 retval->transport = chunk->transport; 1199 1200 nodata: 1201 return retval; 1202 } 1203 1204 /* Create an Operation Error chunk with the specified space reserved. 1205 * This routine can be used for containing multiple causes in the chunk. 1206 */ 1207 static struct sctp_chunk *sctp_make_op_error_space( 1208 const struct sctp_association *asoc, 1209 const struct sctp_chunk *chunk, 1210 size_t size) 1211 { 1212 struct sctp_chunk *retval; 1213 1214 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0, 1215 sizeof(struct sctp_errhdr) + size, 1216 GFP_ATOMIC); 1217 if (!retval) 1218 goto nodata; 1219 1220 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1221 * 1222 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1223 * HEARTBEAT ACK, etc.) to the same destination transport 1224 * address from which it received the DATA or control chunk 1225 * to which it is replying. 1226 * 1227 */ 1228 if (chunk) 1229 retval->transport = chunk->transport; 1230 1231 nodata: 1232 return retval; 1233 } 1234 1235 /* Create an Operation Error chunk of a fixed size, 1236 * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) 1237 * This is a helper function to allocate an error chunk for 1238 * for those invalid parameter codes in which we may not want 1239 * to report all the errors, if the incoming chunk is large 1240 */ 1241 static inline struct sctp_chunk *sctp_make_op_error_fixed( 1242 const struct sctp_association *asoc, 1243 const struct sctp_chunk *chunk) 1244 { 1245 size_t size = asoc ? asoc->pathmtu : 0; 1246 1247 if (!size) 1248 size = SCTP_DEFAULT_MAXSEGMENT; 1249 1250 return sctp_make_op_error_space(asoc, chunk, size); 1251 } 1252 1253 /* Create an Operation Error chunk. */ 1254 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1255 const struct sctp_chunk *chunk, 1256 __be16 cause_code, const void *payload, 1257 size_t paylen, size_t reserve_tail) 1258 { 1259 struct sctp_chunk *retval; 1260 1261 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); 1262 if (!retval) 1263 goto nodata; 1264 1265 sctp_init_cause(retval, cause_code, paylen + reserve_tail); 1266 sctp_addto_chunk(retval, paylen, payload); 1267 if (reserve_tail) 1268 sctp_addto_param(retval, reserve_tail, NULL); 1269 1270 nodata: 1271 return retval; 1272 } 1273 1274 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc) 1275 { 1276 struct sctp_authhdr auth_hdr; 1277 struct sctp_hmac *hmac_desc; 1278 struct sctp_chunk *retval; 1279 1280 /* Get the first hmac that the peer told us to use */ 1281 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1282 if (unlikely(!hmac_desc)) 1283 return NULL; 1284 1285 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0, 1286 hmac_desc->hmac_len + sizeof(auth_hdr), 1287 GFP_ATOMIC); 1288 if (!retval) 1289 return NULL; 1290 1291 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1292 auth_hdr.shkey_id = htons(asoc->active_key_id); 1293 1294 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr), 1295 &auth_hdr); 1296 1297 skb_put_zero(retval->skb, hmac_desc->hmac_len); 1298 1299 /* Adjust the chunk header to include the empty MAC */ 1300 retval->chunk_hdr->length = 1301 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1302 retval->chunk_end = skb_tail_pointer(retval->skb); 1303 1304 return retval; 1305 } 1306 1307 1308 /******************************************************************** 1309 * 2nd Level Abstractions 1310 ********************************************************************/ 1311 1312 /* Turn an skb into a chunk. 1313 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1314 * 1315 * sctpimpguide-05.txt Section 2.8.2 1316 * M1) Each time a new DATA chunk is transmitted 1317 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1318 * 'TSN.Missing.Report' count will be used to determine missing chunks 1319 * and when to fast retransmit. 1320 * 1321 */ 1322 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1323 const struct sctp_association *asoc, 1324 struct sock *sk, gfp_t gfp) 1325 { 1326 struct sctp_chunk *retval; 1327 1328 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp); 1329 1330 if (!retval) 1331 goto nodata; 1332 if (!sk) 1333 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb); 1334 1335 INIT_LIST_HEAD(&retval->list); 1336 retval->skb = skb; 1337 retval->asoc = (struct sctp_association *)asoc; 1338 retval->singleton = 1; 1339 1340 retval->fast_retransmit = SCTP_CAN_FRTX; 1341 1342 /* Polish the bead hole. */ 1343 INIT_LIST_HEAD(&retval->transmitted_list); 1344 INIT_LIST_HEAD(&retval->frag_list); 1345 SCTP_DBG_OBJCNT_INC(chunk); 1346 refcount_set(&retval->refcnt, 1); 1347 1348 nodata: 1349 return retval; 1350 } 1351 1352 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1353 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1354 union sctp_addr *dest) 1355 { 1356 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1357 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1358 } 1359 1360 /* Extract the source address from a chunk. */ 1361 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1362 { 1363 /* If we have a known transport, use that. */ 1364 if (chunk->transport) { 1365 return &chunk->transport->ipaddr; 1366 } else { 1367 /* Otherwise, extract it from the IP header. */ 1368 return &chunk->source; 1369 } 1370 } 1371 1372 /* Create a new chunk, setting the type and flags headers from the 1373 * arguments, reserving enough space for a 'paylen' byte payload. 1374 */ 1375 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 1376 __u8 type, __u8 flags, int paylen, 1377 gfp_t gfp) 1378 { 1379 struct sctp_chunkhdr *chunk_hdr; 1380 struct sctp_chunk *retval; 1381 struct sk_buff *skb; 1382 struct sock *sk; 1383 1384 /* No need to allocate LL here, as this is only a chunk. */ 1385 skb = alloc_skb(SCTP_PAD4(sizeof(*chunk_hdr) + paylen), gfp); 1386 if (!skb) 1387 goto nodata; 1388 1389 /* Make room for the chunk header. */ 1390 chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr)); 1391 chunk_hdr->type = type; 1392 chunk_hdr->flags = flags; 1393 chunk_hdr->length = htons(sizeof(*chunk_hdr)); 1394 1395 sk = asoc ? asoc->base.sk : NULL; 1396 retval = sctp_chunkify(skb, asoc, sk, gfp); 1397 if (!retval) { 1398 kfree_skb(skb); 1399 goto nodata; 1400 } 1401 1402 retval->chunk_hdr = chunk_hdr; 1403 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr); 1404 1405 /* Determine if the chunk needs to be authenticated */ 1406 if (sctp_auth_send_cid(type, asoc)) 1407 retval->auth = 1; 1408 1409 return retval; 1410 nodata: 1411 return NULL; 1412 } 1413 1414 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 1415 __u8 flags, int paylen, gfp_t gfp) 1416 { 1417 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp); 1418 } 1419 1420 struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc, 1421 __u8 flags, int paylen, gfp_t gfp) 1422 { 1423 return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp); 1424 } 1425 1426 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 1427 __u8 type, __u8 flags, int paylen, 1428 gfp_t gfp) 1429 { 1430 struct sctp_chunk *chunk; 1431 1432 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp); 1433 if (chunk) 1434 sctp_control_set_owner_w(chunk); 1435 1436 return chunk; 1437 } 1438 1439 /* Release the memory occupied by a chunk. */ 1440 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1441 { 1442 BUG_ON(!list_empty(&chunk->list)); 1443 list_del_init(&chunk->transmitted_list); 1444 1445 consume_skb(chunk->skb); 1446 consume_skb(chunk->auth_chunk); 1447 1448 SCTP_DBG_OBJCNT_DEC(chunk); 1449 kmem_cache_free(sctp_chunk_cachep, chunk); 1450 } 1451 1452 /* Possibly, free the chunk. */ 1453 void sctp_chunk_free(struct sctp_chunk *chunk) 1454 { 1455 /* Release our reference on the message tracker. */ 1456 if (chunk->msg) 1457 sctp_datamsg_put(chunk->msg); 1458 1459 sctp_chunk_put(chunk); 1460 } 1461 1462 /* Grab a reference to the chunk. */ 1463 void sctp_chunk_hold(struct sctp_chunk *ch) 1464 { 1465 refcount_inc(&ch->refcnt); 1466 } 1467 1468 /* Release a reference to the chunk. */ 1469 void sctp_chunk_put(struct sctp_chunk *ch) 1470 { 1471 if (refcount_dec_and_test(&ch->refcnt)) 1472 sctp_chunk_destroy(ch); 1473 } 1474 1475 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1476 * enough. 1477 */ 1478 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1479 { 1480 int chunklen = ntohs(chunk->chunk_hdr->length); 1481 int padlen = SCTP_PAD4(chunklen) - chunklen; 1482 void *target; 1483 1484 skb_put_zero(chunk->skb, padlen); 1485 target = skb_put_data(chunk->skb, data, len); 1486 1487 /* Adjust the chunk length field. */ 1488 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1489 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1490 1491 return target; 1492 } 1493 1494 /* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient 1495 * space in the chunk 1496 */ 1497 static void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk, 1498 int len, const void *data) 1499 { 1500 if (skb_tailroom(chunk->skb) >= len) 1501 return sctp_addto_chunk(chunk, len, data); 1502 else 1503 return NULL; 1504 } 1505 1506 /* Append bytes from user space to the end of a chunk. Will panic if 1507 * chunk is not big enough. 1508 * Returns a kernel err value. 1509 */ 1510 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len, 1511 struct iov_iter *from) 1512 { 1513 void *target; 1514 1515 /* Make room in chunk for data. */ 1516 target = skb_put(chunk->skb, len); 1517 1518 /* Copy data (whole iovec) into chunk */ 1519 if (!copy_from_iter_full(target, len, from)) 1520 return -EFAULT; 1521 1522 /* Adjust the chunk length field. */ 1523 chunk->chunk_hdr->length = 1524 htons(ntohs(chunk->chunk_hdr->length) + len); 1525 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1526 1527 return 0; 1528 } 1529 1530 /* Helper function to assign a TSN if needed. This assumes that both 1531 * the data_hdr and association have already been assigned. 1532 */ 1533 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1534 { 1535 struct sctp_stream *stream; 1536 struct sctp_chunk *lchunk; 1537 struct sctp_datamsg *msg; 1538 __u16 ssn, sid; 1539 1540 if (chunk->has_ssn) 1541 return; 1542 1543 /* All fragments will be on the same stream */ 1544 sid = ntohs(chunk->subh.data_hdr->stream); 1545 stream = &chunk->asoc->stream; 1546 1547 /* Now assign the sequence number to the entire message. 1548 * All fragments must have the same stream sequence number. 1549 */ 1550 msg = chunk->msg; 1551 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1552 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1553 ssn = 0; 1554 } else { 1555 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1556 ssn = sctp_ssn_next(stream, out, sid); 1557 else 1558 ssn = sctp_ssn_peek(stream, out, sid); 1559 } 1560 1561 lchunk->subh.data_hdr->ssn = htons(ssn); 1562 lchunk->has_ssn = 1; 1563 } 1564 } 1565 1566 /* Helper function to assign a TSN if needed. This assumes that both 1567 * the data_hdr and association have already been assigned. 1568 */ 1569 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1570 { 1571 if (!chunk->has_tsn) { 1572 /* This is the last possible instant to 1573 * assign a TSN. 1574 */ 1575 chunk->subh.data_hdr->tsn = 1576 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1577 chunk->has_tsn = 1; 1578 } 1579 } 1580 1581 /* Create a CLOSED association to use with an incoming packet. */ 1582 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1583 struct sctp_chunk *chunk, 1584 gfp_t gfp) 1585 { 1586 struct sctp_association *asoc; 1587 enum sctp_scope scope; 1588 struct sk_buff *skb; 1589 1590 /* Create the bare association. */ 1591 scope = sctp_scope(sctp_source(chunk)); 1592 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1593 if (!asoc) 1594 goto nodata; 1595 asoc->temp = 1; 1596 skb = chunk->skb; 1597 /* Create an entry for the source address of the packet. */ 1598 SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1); 1599 1600 nodata: 1601 return asoc; 1602 } 1603 1604 /* Build a cookie representing asoc. 1605 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1606 */ 1607 static struct sctp_cookie_param *sctp_pack_cookie( 1608 const struct sctp_endpoint *ep, 1609 const struct sctp_association *asoc, 1610 const struct sctp_chunk *init_chunk, 1611 int *cookie_len, const __u8 *raw_addrs, 1612 int addrs_len) 1613 { 1614 struct sctp_signed_cookie *cookie; 1615 struct sctp_cookie_param *retval; 1616 int headersize, bodysize; 1617 1618 /* Header size is static data prior to the actual cookie, including 1619 * any padding. 1620 */ 1621 headersize = sizeof(struct sctp_paramhdr) + 1622 (sizeof(struct sctp_signed_cookie) - 1623 sizeof(struct sctp_cookie)); 1624 bodysize = sizeof(struct sctp_cookie) 1625 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1626 1627 /* Pad out the cookie to a multiple to make the signature 1628 * functions simpler to write. 1629 */ 1630 if (bodysize % SCTP_COOKIE_MULTIPLE) 1631 bodysize += SCTP_COOKIE_MULTIPLE 1632 - (bodysize % SCTP_COOKIE_MULTIPLE); 1633 *cookie_len = headersize + bodysize; 1634 1635 /* Clear this memory since we are sending this data structure 1636 * out on the network. 1637 */ 1638 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1639 if (!retval) 1640 goto nodata; 1641 1642 cookie = (struct sctp_signed_cookie *) retval->body; 1643 1644 /* Set up the parameter header. */ 1645 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1646 retval->p.length = htons(*cookie_len); 1647 1648 /* Copy the cookie part of the association itself. */ 1649 cookie->c = asoc->c; 1650 /* Save the raw address list length in the cookie. */ 1651 cookie->c.raw_addr_list_len = addrs_len; 1652 1653 /* Remember PR-SCTP capability. */ 1654 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1655 1656 /* Save adaptation indication in the cookie. */ 1657 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1658 1659 /* Set an expiration time for the cookie. */ 1660 cookie->c.expiration = ktime_add(asoc->cookie_life, 1661 ktime_get_real()); 1662 1663 /* Copy the peer's init packet. */ 1664 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr, 1665 ntohs(init_chunk->chunk_hdr->length)); 1666 1667 /* Copy the raw local address list of the association. */ 1668 memcpy((__u8 *)&cookie->c.peer_init[0] + 1669 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1670 1671 if (sctp_sk(ep->base.sk)->hmac) { 1672 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac); 1673 int err; 1674 1675 /* Sign the message. */ 1676 desc->tfm = sctp_sk(ep->base.sk)->hmac; 1677 desc->flags = 0; 1678 1679 err = crypto_shash_setkey(desc->tfm, ep->secret_key, 1680 sizeof(ep->secret_key)) ?: 1681 crypto_shash_digest(desc, (u8 *)&cookie->c, bodysize, 1682 cookie->signature); 1683 shash_desc_zero(desc); 1684 if (err) 1685 goto free_cookie; 1686 } 1687 1688 return retval; 1689 1690 free_cookie: 1691 kfree(retval); 1692 nodata: 1693 *cookie_len = 0; 1694 return NULL; 1695 } 1696 1697 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1698 struct sctp_association *sctp_unpack_cookie( 1699 const struct sctp_endpoint *ep, 1700 const struct sctp_association *asoc, 1701 struct sctp_chunk *chunk, gfp_t gfp, 1702 int *error, struct sctp_chunk **errp) 1703 { 1704 struct sctp_association *retval = NULL; 1705 int headersize, bodysize, fixed_size; 1706 struct sctp_signed_cookie *cookie; 1707 struct sk_buff *skb = chunk->skb; 1708 struct sctp_cookie *bear_cookie; 1709 __u8 *digest = ep->digest; 1710 enum sctp_scope scope; 1711 unsigned int len; 1712 ktime_t kt; 1713 1714 /* Header size is static data prior to the actual cookie, including 1715 * any padding. 1716 */ 1717 headersize = sizeof(struct sctp_chunkhdr) + 1718 (sizeof(struct sctp_signed_cookie) - 1719 sizeof(struct sctp_cookie)); 1720 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1721 fixed_size = headersize + sizeof(struct sctp_cookie); 1722 1723 /* Verify that the chunk looks like it even has a cookie. 1724 * There must be enough room for our cookie and our peer's 1725 * INIT chunk. 1726 */ 1727 len = ntohs(chunk->chunk_hdr->length); 1728 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1729 goto malformed; 1730 1731 /* Verify that the cookie has been padded out. */ 1732 if (bodysize % SCTP_COOKIE_MULTIPLE) 1733 goto malformed; 1734 1735 /* Process the cookie. */ 1736 cookie = chunk->subh.cookie_hdr; 1737 bear_cookie = &cookie->c; 1738 1739 if (!sctp_sk(ep->base.sk)->hmac) 1740 goto no_hmac; 1741 1742 /* Check the signature. */ 1743 { 1744 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac); 1745 int err; 1746 1747 desc->tfm = sctp_sk(ep->base.sk)->hmac; 1748 desc->flags = 0; 1749 1750 err = crypto_shash_setkey(desc->tfm, ep->secret_key, 1751 sizeof(ep->secret_key)) ?: 1752 crypto_shash_digest(desc, (u8 *)bear_cookie, bodysize, 1753 digest); 1754 shash_desc_zero(desc); 1755 1756 if (err) { 1757 *error = -SCTP_IERROR_NOMEM; 1758 goto fail; 1759 } 1760 } 1761 1762 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1763 *error = -SCTP_IERROR_BAD_SIG; 1764 goto fail; 1765 } 1766 1767 no_hmac: 1768 /* IG Section 2.35.2: 1769 * 3) Compare the port numbers and the verification tag contained 1770 * within the COOKIE ECHO chunk to the actual port numbers and the 1771 * verification tag within the SCTP common header of the received 1772 * packet. If these values do not match the packet MUST be silently 1773 * discarded, 1774 */ 1775 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1776 *error = -SCTP_IERROR_BAD_TAG; 1777 goto fail; 1778 } 1779 1780 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1781 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1782 *error = -SCTP_IERROR_BAD_PORTS; 1783 goto fail; 1784 } 1785 1786 /* Check to see if the cookie is stale. If there is already 1787 * an association, there is no need to check cookie's expiration 1788 * for init collision case of lost COOKIE ACK. 1789 * If skb has been timestamped, then use the stamp, otherwise 1790 * use current time. This introduces a small possibility that 1791 * that a cookie may be considered expired, but his would only slow 1792 * down the new association establishment instead of every packet. 1793 */ 1794 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1795 kt = skb_get_ktime(skb); 1796 else 1797 kt = ktime_get_real(); 1798 1799 if (!asoc && ktime_before(bear_cookie->expiration, kt)) { 1800 /* 1801 * Section 3.3.10.3 Stale Cookie Error (3) 1802 * 1803 * Cause of error 1804 * --------------- 1805 * Stale Cookie Error: Indicates the receipt of a valid State 1806 * Cookie that has expired. 1807 */ 1808 len = ntohs(chunk->chunk_hdr->length); 1809 *errp = sctp_make_op_error_space(asoc, chunk, len); 1810 if (*errp) { 1811 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); 1812 __be32 n = htonl(usecs); 1813 1814 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE, 1815 sizeof(n)); 1816 sctp_addto_chunk(*errp, sizeof(n), &n); 1817 *error = -SCTP_IERROR_STALE_COOKIE; 1818 } else 1819 *error = -SCTP_IERROR_NOMEM; 1820 1821 goto fail; 1822 } 1823 1824 /* Make a new base association. */ 1825 scope = sctp_scope(sctp_source(chunk)); 1826 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1827 if (!retval) { 1828 *error = -SCTP_IERROR_NOMEM; 1829 goto fail; 1830 } 1831 1832 /* Set up our peer's port number. */ 1833 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1834 1835 /* Populate the association from the cookie. */ 1836 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1837 1838 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1839 GFP_ATOMIC) < 0) { 1840 *error = -SCTP_IERROR_NOMEM; 1841 goto fail; 1842 } 1843 1844 /* Also, add the destination address. */ 1845 if (list_empty(&retval->base.bind_addr.address_list)) { 1846 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1847 sizeof(chunk->dest), SCTP_ADDR_SRC, 1848 GFP_ATOMIC); 1849 } 1850 1851 retval->next_tsn = retval->c.initial_tsn; 1852 retval->ctsn_ack_point = retval->next_tsn - 1; 1853 retval->addip_serial = retval->c.initial_tsn; 1854 retval->strreset_outseq = retval->c.initial_tsn; 1855 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1856 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1857 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1858 1859 /* The INIT stuff will be done by the side effects. */ 1860 return retval; 1861 1862 fail: 1863 if (retval) 1864 sctp_association_free(retval); 1865 1866 return NULL; 1867 1868 malformed: 1869 /* Yikes! The packet is either corrupt or deliberately 1870 * malformed. 1871 */ 1872 *error = -SCTP_IERROR_MALFORMED; 1873 goto fail; 1874 } 1875 1876 /******************************************************************** 1877 * 3rd Level Abstractions 1878 ********************************************************************/ 1879 1880 struct __sctp_missing { 1881 __be32 num_missing; 1882 __be16 type; 1883 } __packed; 1884 1885 /* 1886 * Report a missing mandatory parameter. 1887 */ 1888 static int sctp_process_missing_param(const struct sctp_association *asoc, 1889 enum sctp_param paramtype, 1890 struct sctp_chunk *chunk, 1891 struct sctp_chunk **errp) 1892 { 1893 struct __sctp_missing report; 1894 __u16 len; 1895 1896 len = SCTP_PAD4(sizeof(report)); 1897 1898 /* Make an ERROR chunk, preparing enough room for 1899 * returning multiple unknown parameters. 1900 */ 1901 if (!*errp) 1902 *errp = sctp_make_op_error_space(asoc, chunk, len); 1903 1904 if (*errp) { 1905 report.num_missing = htonl(1); 1906 report.type = paramtype; 1907 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1908 sizeof(report)); 1909 sctp_addto_chunk(*errp, sizeof(report), &report); 1910 } 1911 1912 /* Stop processing this chunk. */ 1913 return 0; 1914 } 1915 1916 /* Report an Invalid Mandatory Parameter. */ 1917 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1918 struct sctp_chunk *chunk, 1919 struct sctp_chunk **errp) 1920 { 1921 /* Invalid Mandatory Parameter Error has no payload. */ 1922 1923 if (!*errp) 1924 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1925 1926 if (*errp) 1927 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1928 1929 /* Stop processing this chunk. */ 1930 return 0; 1931 } 1932 1933 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1934 struct sctp_paramhdr *param, 1935 const struct sctp_chunk *chunk, 1936 struct sctp_chunk **errp) 1937 { 1938 /* This is a fatal error. Any accumulated non-fatal errors are 1939 * not reported. 1940 */ 1941 if (*errp) 1942 sctp_chunk_free(*errp); 1943 1944 /* Create an error chunk and fill it in with our payload. */ 1945 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1946 1947 return 0; 1948 } 1949 1950 1951 /* Do not attempt to handle the HOST_NAME parm. However, do 1952 * send back an indicator to the peer. 1953 */ 1954 static int sctp_process_hn_param(const struct sctp_association *asoc, 1955 union sctp_params param, 1956 struct sctp_chunk *chunk, 1957 struct sctp_chunk **errp) 1958 { 1959 __u16 len = ntohs(param.p->length); 1960 1961 /* Processing of the HOST_NAME parameter will generate an 1962 * ABORT. If we've accumulated any non-fatal errors, they 1963 * would be unrecognized parameters and we should not include 1964 * them in the ABORT. 1965 */ 1966 if (*errp) 1967 sctp_chunk_free(*errp); 1968 1969 *errp = sctp_make_op_error_space(asoc, chunk, len); 1970 1971 if (*errp) { 1972 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len); 1973 sctp_addto_chunk(*errp, len, param.v); 1974 } 1975 1976 /* Stop processing this chunk. */ 1977 return 0; 1978 } 1979 1980 static int sctp_verify_ext_param(struct net *net, union sctp_params param) 1981 { 1982 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 1983 int have_asconf = 0; 1984 int have_auth = 0; 1985 int i; 1986 1987 for (i = 0; i < num_ext; i++) { 1988 switch (param.ext->chunks[i]) { 1989 case SCTP_CID_AUTH: 1990 have_auth = 1; 1991 break; 1992 case SCTP_CID_ASCONF: 1993 case SCTP_CID_ASCONF_ACK: 1994 have_asconf = 1; 1995 break; 1996 } 1997 } 1998 1999 /* ADD-IP Security: The draft requires us to ABORT or ignore the 2000 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 2001 * only if ADD-IP is turned on and we are not backward-compatible 2002 * mode. 2003 */ 2004 if (net->sctp.addip_noauth) 2005 return 1; 2006 2007 if (net->sctp.addip_enable && !have_auth && have_asconf) 2008 return 0; 2009 2010 return 1; 2011 } 2012 2013 static void sctp_process_ext_param(struct sctp_association *asoc, 2014 union sctp_params param) 2015 { 2016 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2017 struct net *net = sock_net(asoc->base.sk); 2018 int i; 2019 2020 for (i = 0; i < num_ext; i++) { 2021 switch (param.ext->chunks[i]) { 2022 case SCTP_CID_RECONF: 2023 if (asoc->reconf_enable && 2024 !asoc->peer.reconf_capable) 2025 asoc->peer.reconf_capable = 1; 2026 break; 2027 case SCTP_CID_FWD_TSN: 2028 if (asoc->prsctp_enable && !asoc->peer.prsctp_capable) 2029 asoc->peer.prsctp_capable = 1; 2030 break; 2031 case SCTP_CID_AUTH: 2032 /* if the peer reports AUTH, assume that he 2033 * supports AUTH. 2034 */ 2035 if (asoc->ep->auth_enable) 2036 asoc->peer.auth_capable = 1; 2037 break; 2038 case SCTP_CID_ASCONF: 2039 case SCTP_CID_ASCONF_ACK: 2040 if (net->sctp.addip_enable) 2041 asoc->peer.asconf_capable = 1; 2042 break; 2043 case SCTP_CID_I_DATA: 2044 if (sctp_sk(asoc->base.sk)->strm_interleave) 2045 asoc->intl_enable = 1; 2046 break; 2047 default: 2048 break; 2049 } 2050 } 2051 } 2052 2053 /* RFC 3.2.1 & the Implementers Guide 2.2. 2054 * 2055 * The Parameter Types are encoded such that the 2056 * highest-order two bits specify the action that must be 2057 * taken if the processing endpoint does not recognize the 2058 * Parameter Type. 2059 * 2060 * 00 - Stop processing this parameter; do not process any further 2061 * parameters within this chunk 2062 * 2063 * 01 - Stop processing this parameter, do not process any further 2064 * parameters within this chunk, and report the unrecognized 2065 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2066 * 2067 * 10 - Skip this parameter and continue processing. 2068 * 2069 * 11 - Skip this parameter and continue processing but 2070 * report the unrecognized parameter in an 2071 * 'Unrecognized Parameter' ERROR chunk. 2072 * 2073 * Return value: 2074 * SCTP_IERROR_NO_ERROR - continue with the chunk 2075 * SCTP_IERROR_ERROR - stop and report an error. 2076 * SCTP_IERROR_NOMEME - out of memory. 2077 */ 2078 static enum sctp_ierror sctp_process_unk_param( 2079 const struct sctp_association *asoc, 2080 union sctp_params param, 2081 struct sctp_chunk *chunk, 2082 struct sctp_chunk **errp) 2083 { 2084 int retval = SCTP_IERROR_NO_ERROR; 2085 2086 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2087 case SCTP_PARAM_ACTION_DISCARD: 2088 retval = SCTP_IERROR_ERROR; 2089 break; 2090 case SCTP_PARAM_ACTION_SKIP: 2091 break; 2092 case SCTP_PARAM_ACTION_DISCARD_ERR: 2093 retval = SCTP_IERROR_ERROR; 2094 /* Fall through */ 2095 case SCTP_PARAM_ACTION_SKIP_ERR: 2096 /* Make an ERROR chunk, preparing enough room for 2097 * returning multiple unknown parameters. 2098 */ 2099 if (NULL == *errp) 2100 *errp = sctp_make_op_error_fixed(asoc, chunk); 2101 2102 if (*errp) { 2103 if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2104 SCTP_PAD4(ntohs(param.p->length)))) 2105 sctp_addto_chunk_fixed(*errp, 2106 SCTP_PAD4(ntohs(param.p->length)), 2107 param.v); 2108 } else { 2109 /* If there is no memory for generating the ERROR 2110 * report as specified, an ABORT will be triggered 2111 * to the peer and the association won't be 2112 * established. 2113 */ 2114 retval = SCTP_IERROR_NOMEM; 2115 } 2116 break; 2117 default: 2118 break; 2119 } 2120 2121 return retval; 2122 } 2123 2124 /* Verify variable length parameters 2125 * Return values: 2126 * SCTP_IERROR_ABORT - trigger an ABORT 2127 * SCTP_IERROR_NOMEM - out of memory (abort) 2128 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2129 * SCTP_IERROR_NO_ERROR - continue with the chunk 2130 */ 2131 static enum sctp_ierror sctp_verify_param(struct net *net, 2132 const struct sctp_endpoint *ep, 2133 const struct sctp_association *asoc, 2134 union sctp_params param, 2135 enum sctp_cid cid, 2136 struct sctp_chunk *chunk, 2137 struct sctp_chunk **err_chunk) 2138 { 2139 struct sctp_hmac_algo_param *hmacs; 2140 int retval = SCTP_IERROR_NO_ERROR; 2141 __u16 n_elt, id = 0; 2142 int i; 2143 2144 /* FIXME - This routine is not looking at each parameter per the 2145 * chunk type, i.e., unrecognized parameters should be further 2146 * identified based on the chunk id. 2147 */ 2148 2149 switch (param.p->type) { 2150 case SCTP_PARAM_IPV4_ADDRESS: 2151 case SCTP_PARAM_IPV6_ADDRESS: 2152 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2153 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2154 case SCTP_PARAM_STATE_COOKIE: 2155 case SCTP_PARAM_HEARTBEAT_INFO: 2156 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2157 case SCTP_PARAM_ECN_CAPABLE: 2158 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2159 break; 2160 2161 case SCTP_PARAM_SUPPORTED_EXT: 2162 if (!sctp_verify_ext_param(net, param)) 2163 return SCTP_IERROR_ABORT; 2164 break; 2165 2166 case SCTP_PARAM_SET_PRIMARY: 2167 if (net->sctp.addip_enable) 2168 break; 2169 goto fallthrough; 2170 2171 case SCTP_PARAM_HOST_NAME_ADDRESS: 2172 /* Tell the peer, we won't support this param. */ 2173 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2174 retval = SCTP_IERROR_ABORT; 2175 break; 2176 2177 case SCTP_PARAM_FWD_TSN_SUPPORT: 2178 if (ep->prsctp_enable) 2179 break; 2180 goto fallthrough; 2181 2182 case SCTP_PARAM_RANDOM: 2183 if (!ep->auth_enable) 2184 goto fallthrough; 2185 2186 /* SCTP-AUTH: Secion 6.1 2187 * If the random number is not 32 byte long the association 2188 * MUST be aborted. The ABORT chunk SHOULD contain the error 2189 * cause 'Protocol Violation'. 2190 */ 2191 if (SCTP_AUTH_RANDOM_LENGTH != 2192 ntohs(param.p->length) - sizeof(struct sctp_paramhdr)) { 2193 sctp_process_inv_paramlength(asoc, param.p, 2194 chunk, err_chunk); 2195 retval = SCTP_IERROR_ABORT; 2196 } 2197 break; 2198 2199 case SCTP_PARAM_CHUNKS: 2200 if (!ep->auth_enable) 2201 goto fallthrough; 2202 2203 /* SCTP-AUTH: Section 3.2 2204 * The CHUNKS parameter MUST be included once in the INIT or 2205 * INIT-ACK chunk if the sender wants to receive authenticated 2206 * chunks. Its maximum length is 260 bytes. 2207 */ 2208 if (260 < ntohs(param.p->length)) { 2209 sctp_process_inv_paramlength(asoc, param.p, 2210 chunk, err_chunk); 2211 retval = SCTP_IERROR_ABORT; 2212 } 2213 break; 2214 2215 case SCTP_PARAM_HMAC_ALGO: 2216 if (!ep->auth_enable) 2217 goto fallthrough; 2218 2219 hmacs = (struct sctp_hmac_algo_param *)param.p; 2220 n_elt = (ntohs(param.p->length) - 2221 sizeof(struct sctp_paramhdr)) >> 1; 2222 2223 /* SCTP-AUTH: Section 6.1 2224 * The HMAC algorithm based on SHA-1 MUST be supported and 2225 * included in the HMAC-ALGO parameter. 2226 */ 2227 for (i = 0; i < n_elt; i++) { 2228 id = ntohs(hmacs->hmac_ids[i]); 2229 2230 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2231 break; 2232 } 2233 2234 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2235 sctp_process_inv_paramlength(asoc, param.p, chunk, 2236 err_chunk); 2237 retval = SCTP_IERROR_ABORT; 2238 } 2239 break; 2240 fallthrough: 2241 default: 2242 pr_debug("%s: unrecognized param:%d for chunk:%d\n", 2243 __func__, ntohs(param.p->type), cid); 2244 2245 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2246 break; 2247 } 2248 return retval; 2249 } 2250 2251 /* Verify the INIT packet before we process it. */ 2252 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 2253 const struct sctp_association *asoc, enum sctp_cid cid, 2254 struct sctp_init_chunk *peer_init, 2255 struct sctp_chunk *chunk, struct sctp_chunk **errp) 2256 { 2257 union sctp_params param; 2258 bool has_cookie = false; 2259 int result; 2260 2261 /* Check for missing mandatory parameters. Note: Initial TSN is 2262 * also mandatory, but is not checked here since the valid range 2263 * is 0..2**32-1. RFC4960, section 3.3.3. 2264 */ 2265 if (peer_init->init_hdr.num_outbound_streams == 0 || 2266 peer_init->init_hdr.num_inbound_streams == 0 || 2267 peer_init->init_hdr.init_tag == 0 || 2268 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) 2269 return sctp_process_inv_mandatory(asoc, chunk, errp); 2270 2271 sctp_walk_params(param, peer_init, init_hdr.params) { 2272 if (param.p->type == SCTP_PARAM_STATE_COOKIE) 2273 has_cookie = true; 2274 } 2275 2276 /* There is a possibility that a parameter length was bad and 2277 * in that case we would have stoped walking the parameters. 2278 * The current param.p would point at the bad one. 2279 * Current consensus on the mailing list is to generate a PROTOCOL 2280 * VIOLATION error. We build the ERROR chunk here and let the normal 2281 * error handling code build and send the packet. 2282 */ 2283 if (param.v != (void *)chunk->chunk_end) 2284 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2285 2286 /* The only missing mandatory param possible today is 2287 * the state cookie for an INIT-ACK chunk. 2288 */ 2289 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2290 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2291 chunk, errp); 2292 2293 /* Verify all the variable length parameters */ 2294 sctp_walk_params(param, peer_init, init_hdr.params) { 2295 result = sctp_verify_param(net, ep, asoc, param, cid, 2296 chunk, errp); 2297 switch (result) { 2298 case SCTP_IERROR_ABORT: 2299 case SCTP_IERROR_NOMEM: 2300 return 0; 2301 case SCTP_IERROR_ERROR: 2302 return 1; 2303 case SCTP_IERROR_NO_ERROR: 2304 default: 2305 break; 2306 } 2307 2308 } /* for (loop through all parameters) */ 2309 2310 return 1; 2311 } 2312 2313 /* Unpack the parameters in an INIT packet into an association. 2314 * Returns 0 on failure, else success. 2315 * FIXME: This is an association method. 2316 */ 2317 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2318 const union sctp_addr *peer_addr, 2319 struct sctp_init_chunk *peer_init, gfp_t gfp) 2320 { 2321 struct net *net = sock_net(asoc->base.sk); 2322 struct sctp_transport *transport; 2323 struct list_head *pos, *temp; 2324 union sctp_params param; 2325 union sctp_addr addr; 2326 struct sctp_af *af; 2327 int src_match = 0; 2328 char *cookie; 2329 2330 /* We must include the address that the INIT packet came from. 2331 * This is the only address that matters for an INIT packet. 2332 * When processing a COOKIE ECHO, we retrieve the from address 2333 * of the INIT from the cookie. 2334 */ 2335 2336 /* This implementation defaults to making the first transport 2337 * added as the primary transport. The source address seems to 2338 * be a a better choice than any of the embedded addresses. 2339 */ 2340 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2341 goto nomem; 2342 2343 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2344 src_match = 1; 2345 2346 /* Process the initialization parameters. */ 2347 sctp_walk_params(param, peer_init, init_hdr.params) { 2348 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2349 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2350 af = sctp_get_af_specific(param_type2af(param.p->type)); 2351 af->from_addr_param(&addr, param.addr, 2352 chunk->sctp_hdr->source, 0); 2353 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2354 src_match = 1; 2355 } 2356 2357 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2358 goto clean_up; 2359 } 2360 2361 /* source address of chunk may not match any valid address */ 2362 if (!src_match) 2363 goto clean_up; 2364 2365 /* AUTH: After processing the parameters, make sure that we 2366 * have all the required info to potentially do authentications. 2367 */ 2368 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2369 !asoc->peer.peer_hmacs)) 2370 asoc->peer.auth_capable = 0; 2371 2372 /* In a non-backward compatible mode, if the peer claims 2373 * support for ADD-IP but not AUTH, the ADD-IP spec states 2374 * that we MUST ABORT the association. Section 6. The section 2375 * also give us an option to silently ignore the packet, which 2376 * is what we'll do here. 2377 */ 2378 if (!net->sctp.addip_noauth && 2379 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2380 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2381 SCTP_PARAM_DEL_IP | 2382 SCTP_PARAM_SET_PRIMARY); 2383 asoc->peer.asconf_capable = 0; 2384 goto clean_up; 2385 } 2386 2387 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2388 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2389 transport = list_entry(pos, struct sctp_transport, transports); 2390 if (transport->state == SCTP_UNKNOWN) { 2391 sctp_assoc_rm_peer(asoc, transport); 2392 } 2393 } 2394 2395 /* The fixed INIT headers are always in network byte 2396 * order. 2397 */ 2398 asoc->peer.i.init_tag = 2399 ntohl(peer_init->init_hdr.init_tag); 2400 asoc->peer.i.a_rwnd = 2401 ntohl(peer_init->init_hdr.a_rwnd); 2402 asoc->peer.i.num_outbound_streams = 2403 ntohs(peer_init->init_hdr.num_outbound_streams); 2404 asoc->peer.i.num_inbound_streams = 2405 ntohs(peer_init->init_hdr.num_inbound_streams); 2406 asoc->peer.i.initial_tsn = 2407 ntohl(peer_init->init_hdr.initial_tsn); 2408 2409 asoc->strreset_inseq = asoc->peer.i.initial_tsn; 2410 2411 /* Apply the upper bounds for output streams based on peer's 2412 * number of inbound streams. 2413 */ 2414 if (asoc->c.sinit_num_ostreams > 2415 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2416 asoc->c.sinit_num_ostreams = 2417 ntohs(peer_init->init_hdr.num_inbound_streams); 2418 } 2419 2420 if (asoc->c.sinit_max_instreams > 2421 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2422 asoc->c.sinit_max_instreams = 2423 ntohs(peer_init->init_hdr.num_outbound_streams); 2424 } 2425 2426 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2427 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2428 2429 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2430 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2431 2432 /* Copy cookie in case we need to resend COOKIE-ECHO. */ 2433 cookie = asoc->peer.cookie; 2434 if (cookie) { 2435 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp); 2436 if (!asoc->peer.cookie) 2437 goto clean_up; 2438 } 2439 2440 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2441 * high (for example, implementations MAY use the size of the receiver 2442 * advertised window). 2443 */ 2444 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2445 transports) { 2446 transport->ssthresh = asoc->peer.i.a_rwnd; 2447 } 2448 2449 /* Set up the TSN tracking pieces. */ 2450 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2451 asoc->peer.i.initial_tsn, gfp)) 2452 goto clean_up; 2453 2454 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2455 * 2456 * The stream sequence number in all the streams shall start 2457 * from 0 when the association is established. Also, when the 2458 * stream sequence number reaches the value 65535 the next 2459 * stream sequence number shall be set to 0. 2460 */ 2461 2462 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams, 2463 asoc->c.sinit_max_instreams, gfp)) 2464 goto clean_up; 2465 2466 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp)) 2467 goto clean_up; 2468 2469 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2470 * 2471 * When an endpoint has an ASCONF signaled change to be sent to the 2472 * remote endpoint it should do the following: 2473 * ... 2474 * A2) A serial number should be assigned to the Chunk. The serial 2475 * number should be a monotonically increasing number. All serial 2476 * numbers are defined to be initialized at the start of the 2477 * association to the same value as the Initial TSN. 2478 */ 2479 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2480 return 1; 2481 2482 clean_up: 2483 /* Release the transport structures. */ 2484 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2485 transport = list_entry(pos, struct sctp_transport, transports); 2486 if (transport->state != SCTP_ACTIVE) 2487 sctp_assoc_rm_peer(asoc, transport); 2488 } 2489 2490 nomem: 2491 return 0; 2492 } 2493 2494 2495 /* Update asoc with the option described in param. 2496 * 2497 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2498 * 2499 * asoc is the association to update. 2500 * param is the variable length parameter to use for update. 2501 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2502 * If the current packet is an INIT we want to minimize the amount of 2503 * work we do. In particular, we should not build transport 2504 * structures for the addresses. 2505 */ 2506 static int sctp_process_param(struct sctp_association *asoc, 2507 union sctp_params param, 2508 const union sctp_addr *peer_addr, 2509 gfp_t gfp) 2510 { 2511 struct net *net = sock_net(asoc->base.sk); 2512 struct sctp_endpoint *ep = asoc->ep; 2513 union sctp_addr_param *addr_param; 2514 struct sctp_transport *t; 2515 enum sctp_scope scope; 2516 union sctp_addr addr; 2517 struct sctp_af *af; 2518 int retval = 1, i; 2519 u32 stale; 2520 __u16 sat; 2521 2522 /* We maintain all INIT parameters in network byte order all the 2523 * time. This allows us to not worry about whether the parameters 2524 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2525 */ 2526 switch (param.p->type) { 2527 case SCTP_PARAM_IPV6_ADDRESS: 2528 if (PF_INET6 != asoc->base.sk->sk_family) 2529 break; 2530 goto do_addr_param; 2531 2532 case SCTP_PARAM_IPV4_ADDRESS: 2533 /* v4 addresses are not allowed on v6-only socket */ 2534 if (ipv6_only_sock(asoc->base.sk)) 2535 break; 2536 do_addr_param: 2537 af = sctp_get_af_specific(param_type2af(param.p->type)); 2538 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); 2539 scope = sctp_scope(peer_addr); 2540 if (sctp_in_scope(net, &addr, scope)) 2541 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2542 return 0; 2543 break; 2544 2545 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2546 if (!net->sctp.cookie_preserve_enable) 2547 break; 2548 2549 stale = ntohl(param.life->lifespan_increment); 2550 2551 /* Suggested Cookie Life span increment's unit is msec, 2552 * (1/1000sec). 2553 */ 2554 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale); 2555 break; 2556 2557 case SCTP_PARAM_HOST_NAME_ADDRESS: 2558 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__); 2559 break; 2560 2561 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2562 /* Turn off the default values first so we'll know which 2563 * ones are really set by the peer. 2564 */ 2565 asoc->peer.ipv4_address = 0; 2566 asoc->peer.ipv6_address = 0; 2567 2568 /* Assume that peer supports the address family 2569 * by which it sends a packet. 2570 */ 2571 if (peer_addr->sa.sa_family == AF_INET6) 2572 asoc->peer.ipv6_address = 1; 2573 else if (peer_addr->sa.sa_family == AF_INET) 2574 asoc->peer.ipv4_address = 1; 2575 2576 /* Cycle through address types; avoid divide by 0. */ 2577 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2578 if (sat) 2579 sat /= sizeof(__u16); 2580 2581 for (i = 0; i < sat; ++i) { 2582 switch (param.sat->types[i]) { 2583 case SCTP_PARAM_IPV4_ADDRESS: 2584 asoc->peer.ipv4_address = 1; 2585 break; 2586 2587 case SCTP_PARAM_IPV6_ADDRESS: 2588 if (PF_INET6 == asoc->base.sk->sk_family) 2589 asoc->peer.ipv6_address = 1; 2590 break; 2591 2592 case SCTP_PARAM_HOST_NAME_ADDRESS: 2593 asoc->peer.hostname_address = 1; 2594 break; 2595 2596 default: /* Just ignore anything else. */ 2597 break; 2598 } 2599 } 2600 break; 2601 2602 case SCTP_PARAM_STATE_COOKIE: 2603 asoc->peer.cookie_len = 2604 ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2605 asoc->peer.cookie = param.cookie->body; 2606 break; 2607 2608 case SCTP_PARAM_HEARTBEAT_INFO: 2609 /* Would be odd to receive, but it causes no problems. */ 2610 break; 2611 2612 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2613 /* Rejected during verify stage. */ 2614 break; 2615 2616 case SCTP_PARAM_ECN_CAPABLE: 2617 asoc->peer.ecn_capable = 1; 2618 break; 2619 2620 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2621 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2622 break; 2623 2624 case SCTP_PARAM_SET_PRIMARY: 2625 if (!net->sctp.addip_enable) 2626 goto fall_through; 2627 2628 addr_param = param.v + sizeof(struct sctp_addip_param); 2629 2630 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 2631 if (af == NULL) 2632 break; 2633 2634 af->from_addr_param(&addr, addr_param, 2635 htons(asoc->peer.port), 0); 2636 2637 /* if the address is invalid, we can't process it. 2638 * XXX: see spec for what to do. 2639 */ 2640 if (!af->addr_valid(&addr, NULL, NULL)) 2641 break; 2642 2643 t = sctp_assoc_lookup_paddr(asoc, &addr); 2644 if (!t) 2645 break; 2646 2647 sctp_assoc_set_primary(asoc, t); 2648 break; 2649 2650 case SCTP_PARAM_SUPPORTED_EXT: 2651 sctp_process_ext_param(asoc, param); 2652 break; 2653 2654 case SCTP_PARAM_FWD_TSN_SUPPORT: 2655 if (asoc->prsctp_enable) { 2656 asoc->peer.prsctp_capable = 1; 2657 break; 2658 } 2659 /* Fall Through */ 2660 goto fall_through; 2661 2662 case SCTP_PARAM_RANDOM: 2663 if (!ep->auth_enable) 2664 goto fall_through; 2665 2666 /* Save peer's random parameter */ 2667 asoc->peer.peer_random = kmemdup(param.p, 2668 ntohs(param.p->length), gfp); 2669 if (!asoc->peer.peer_random) { 2670 retval = 0; 2671 break; 2672 } 2673 break; 2674 2675 case SCTP_PARAM_HMAC_ALGO: 2676 if (!ep->auth_enable) 2677 goto fall_through; 2678 2679 /* Save peer's HMAC list */ 2680 asoc->peer.peer_hmacs = kmemdup(param.p, 2681 ntohs(param.p->length), gfp); 2682 if (!asoc->peer.peer_hmacs) { 2683 retval = 0; 2684 break; 2685 } 2686 2687 /* Set the default HMAC the peer requested*/ 2688 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2689 break; 2690 2691 case SCTP_PARAM_CHUNKS: 2692 if (!ep->auth_enable) 2693 goto fall_through; 2694 2695 asoc->peer.peer_chunks = kmemdup(param.p, 2696 ntohs(param.p->length), gfp); 2697 if (!asoc->peer.peer_chunks) 2698 retval = 0; 2699 break; 2700 fall_through: 2701 default: 2702 /* Any unrecognized parameters should have been caught 2703 * and handled by sctp_verify_param() which should be 2704 * called prior to this routine. Simply log the error 2705 * here. 2706 */ 2707 pr_debug("%s: ignoring param:%d for association:%p.\n", 2708 __func__, ntohs(param.p->type), asoc); 2709 break; 2710 } 2711 2712 return retval; 2713 } 2714 2715 /* Select a new verification tag. */ 2716 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2717 { 2718 /* I believe that this random number generator complies with RFC1750. 2719 * A tag of 0 is reserved for special cases (e.g. INIT). 2720 */ 2721 __u32 x; 2722 2723 do { 2724 get_random_bytes(&x, sizeof(__u32)); 2725 } while (x == 0); 2726 2727 return x; 2728 } 2729 2730 /* Select an initial TSN to send during startup. */ 2731 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2732 { 2733 __u32 retval; 2734 2735 get_random_bytes(&retval, sizeof(__u32)); 2736 return retval; 2737 } 2738 2739 /* 2740 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2741 * 0 1 2 3 2742 * 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 2743 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2744 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2745 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2746 * | Serial Number | 2747 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2748 * | Address Parameter | 2749 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2750 * | ASCONF Parameter #1 | 2751 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2752 * \ \ 2753 * / .... / 2754 * \ \ 2755 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2756 * | ASCONF Parameter #N | 2757 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2758 * 2759 * Address Parameter and other parameter will not be wrapped in this function 2760 */ 2761 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2762 union sctp_addr *addr, 2763 int vparam_len) 2764 { 2765 struct sctp_addiphdr asconf; 2766 struct sctp_chunk *retval; 2767 int length = sizeof(asconf) + vparam_len; 2768 union sctp_addr_param addrparam; 2769 int addrlen; 2770 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2771 2772 addrlen = af->to_addr_param(addr, &addrparam); 2773 if (!addrlen) 2774 return NULL; 2775 length += addrlen; 2776 2777 /* Create the chunk. */ 2778 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length, 2779 GFP_ATOMIC); 2780 if (!retval) 2781 return NULL; 2782 2783 asconf.serial = htonl(asoc->addip_serial++); 2784 2785 retval->subh.addip_hdr = 2786 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2787 retval->param_hdr.v = 2788 sctp_addto_chunk(retval, addrlen, &addrparam); 2789 2790 return retval; 2791 } 2792 2793 /* ADDIP 2794 * 3.2.1 Add IP Address 2795 * 0 1 2 3 2796 * 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 2797 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2798 * | Type = 0xC001 | Length = Variable | 2799 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2800 * | ASCONF-Request Correlation ID | 2801 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2802 * | Address Parameter | 2803 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2804 * 2805 * 3.2.2 Delete IP Address 2806 * 0 1 2 3 2807 * 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 2808 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2809 * | Type = 0xC002 | Length = Variable | 2810 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2811 * | ASCONF-Request Correlation ID | 2812 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2813 * | Address Parameter | 2814 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2815 * 2816 */ 2817 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2818 union sctp_addr *laddr, 2819 struct sockaddr *addrs, 2820 int addrcnt, __be16 flags) 2821 { 2822 union sctp_addr_param addr_param; 2823 struct sctp_addip_param param; 2824 int paramlen = sizeof(param); 2825 struct sctp_chunk *retval; 2826 int addr_param_len = 0; 2827 union sctp_addr *addr; 2828 int totallen = 0, i; 2829 int del_pickup = 0; 2830 struct sctp_af *af; 2831 void *addr_buf; 2832 2833 /* Get total length of all the address parameters. */ 2834 addr_buf = addrs; 2835 for (i = 0; i < addrcnt; i++) { 2836 addr = addr_buf; 2837 af = sctp_get_af_specific(addr->v4.sin_family); 2838 addr_param_len = af->to_addr_param(addr, &addr_param); 2839 2840 totallen += paramlen; 2841 totallen += addr_param_len; 2842 2843 addr_buf += af->sockaddr_len; 2844 if (asoc->asconf_addr_del_pending && !del_pickup) { 2845 /* reuse the parameter length from the same scope one */ 2846 totallen += paramlen; 2847 totallen += addr_param_len; 2848 del_pickup = 1; 2849 2850 pr_debug("%s: picked same-scope del_pending addr, " 2851 "totallen for all addresses is %d\n", 2852 __func__, totallen); 2853 } 2854 } 2855 2856 /* Create an asconf chunk with the required length. */ 2857 retval = sctp_make_asconf(asoc, laddr, totallen); 2858 if (!retval) 2859 return NULL; 2860 2861 /* Add the address parameters to the asconf chunk. */ 2862 addr_buf = addrs; 2863 for (i = 0; i < addrcnt; i++) { 2864 addr = addr_buf; 2865 af = sctp_get_af_specific(addr->v4.sin_family); 2866 addr_param_len = af->to_addr_param(addr, &addr_param); 2867 param.param_hdr.type = flags; 2868 param.param_hdr.length = htons(paramlen + addr_param_len); 2869 param.crr_id = htonl(i); 2870 2871 sctp_addto_chunk(retval, paramlen, ¶m); 2872 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2873 2874 addr_buf += af->sockaddr_len; 2875 } 2876 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2877 addr = asoc->asconf_addr_del_pending; 2878 af = sctp_get_af_specific(addr->v4.sin_family); 2879 addr_param_len = af->to_addr_param(addr, &addr_param); 2880 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2881 param.param_hdr.length = htons(paramlen + addr_param_len); 2882 param.crr_id = htonl(i); 2883 2884 sctp_addto_chunk(retval, paramlen, ¶m); 2885 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2886 } 2887 return retval; 2888 } 2889 2890 /* ADDIP 2891 * 3.2.4 Set Primary IP Address 2892 * 0 1 2 3 2893 * 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 2894 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2895 * | Type =0xC004 | Length = Variable | 2896 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2897 * | ASCONF-Request Correlation ID | 2898 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2899 * | Address Parameter | 2900 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2901 * 2902 * Create an ASCONF chunk with Set Primary IP address parameter. 2903 */ 2904 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2905 union sctp_addr *addr) 2906 { 2907 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2908 union sctp_addr_param addrparam; 2909 struct sctp_addip_param param; 2910 struct sctp_chunk *retval; 2911 int len = sizeof(param); 2912 int addrlen; 2913 2914 addrlen = af->to_addr_param(addr, &addrparam); 2915 if (!addrlen) 2916 return NULL; 2917 len += addrlen; 2918 2919 /* Create the chunk and make asconf header. */ 2920 retval = sctp_make_asconf(asoc, addr, len); 2921 if (!retval) 2922 return NULL; 2923 2924 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2925 param.param_hdr.length = htons(len); 2926 param.crr_id = 0; 2927 2928 sctp_addto_chunk(retval, sizeof(param), ¶m); 2929 sctp_addto_chunk(retval, addrlen, &addrparam); 2930 2931 return retval; 2932 } 2933 2934 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2935 * 0 1 2 3 2936 * 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 2937 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2938 * | Type = 0x80 | Chunk Flags | Chunk Length | 2939 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2940 * | Serial Number | 2941 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2942 * | ASCONF Parameter Response#1 | 2943 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2944 * \ \ 2945 * / .... / 2946 * \ \ 2947 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2948 * | ASCONF Parameter Response#N | 2949 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2950 * 2951 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2952 */ 2953 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2954 __u32 serial, int vparam_len) 2955 { 2956 struct sctp_addiphdr asconf; 2957 struct sctp_chunk *retval; 2958 int length = sizeof(asconf) + vparam_len; 2959 2960 /* Create the chunk. */ 2961 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length, 2962 GFP_ATOMIC); 2963 if (!retval) 2964 return NULL; 2965 2966 asconf.serial = htonl(serial); 2967 2968 retval->subh.addip_hdr = 2969 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2970 2971 return retval; 2972 } 2973 2974 /* Add response parameters to an ASCONF_ACK chunk. */ 2975 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2976 __be16 err_code, 2977 struct sctp_addip_param *asconf_param) 2978 { 2979 struct sctp_addip_param ack_param; 2980 struct sctp_errhdr err_param; 2981 int asconf_param_len = 0; 2982 int err_param_len = 0; 2983 __be16 response_type; 2984 2985 if (SCTP_ERROR_NO_ERROR == err_code) { 2986 response_type = SCTP_PARAM_SUCCESS_REPORT; 2987 } else { 2988 response_type = SCTP_PARAM_ERR_CAUSE; 2989 err_param_len = sizeof(err_param); 2990 if (asconf_param) 2991 asconf_param_len = 2992 ntohs(asconf_param->param_hdr.length); 2993 } 2994 2995 /* Add Success Indication or Error Cause Indication parameter. */ 2996 ack_param.param_hdr.type = response_type; 2997 ack_param.param_hdr.length = htons(sizeof(ack_param) + 2998 err_param_len + 2999 asconf_param_len); 3000 ack_param.crr_id = crr_id; 3001 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 3002 3003 if (SCTP_ERROR_NO_ERROR == err_code) 3004 return; 3005 3006 /* Add Error Cause parameter. */ 3007 err_param.cause = err_code; 3008 err_param.length = htons(err_param_len + asconf_param_len); 3009 sctp_addto_chunk(chunk, err_param_len, &err_param); 3010 3011 /* Add the failed TLV copied from ASCONF chunk. */ 3012 if (asconf_param) 3013 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 3014 } 3015 3016 /* Process a asconf parameter. */ 3017 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 3018 struct sctp_chunk *asconf, 3019 struct sctp_addip_param *asconf_param) 3020 { 3021 union sctp_addr_param *addr_param; 3022 struct sctp_transport *peer; 3023 union sctp_addr addr; 3024 struct sctp_af *af; 3025 3026 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3027 3028 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 3029 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 3030 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 3031 return SCTP_ERROR_UNKNOWN_PARAM; 3032 3033 switch (addr_param->p.type) { 3034 case SCTP_PARAM_IPV6_ADDRESS: 3035 if (!asoc->peer.ipv6_address) 3036 return SCTP_ERROR_DNS_FAILED; 3037 break; 3038 case SCTP_PARAM_IPV4_ADDRESS: 3039 if (!asoc->peer.ipv4_address) 3040 return SCTP_ERROR_DNS_FAILED; 3041 break; 3042 default: 3043 return SCTP_ERROR_DNS_FAILED; 3044 } 3045 3046 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3047 if (unlikely(!af)) 3048 return SCTP_ERROR_DNS_FAILED; 3049 3050 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); 3051 3052 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3053 * or multicast address. 3054 * (note: wildcard is permitted and requires special handling so 3055 * make sure we check for that) 3056 */ 3057 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3058 return SCTP_ERROR_DNS_FAILED; 3059 3060 switch (asconf_param->param_hdr.type) { 3061 case SCTP_PARAM_ADD_IP: 3062 /* Section 4.2.1: 3063 * If the address 0.0.0.0 or ::0 is provided, the source 3064 * address of the packet MUST be added. 3065 */ 3066 if (af->is_any(&addr)) 3067 memcpy(&addr, &asconf->source, sizeof(addr)); 3068 3069 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3070 * request and does not have the local resources to add this 3071 * new address to the association, it MUST return an Error 3072 * Cause TLV set to the new error code 'Operation Refused 3073 * Due to Resource Shortage'. 3074 */ 3075 3076 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3077 if (!peer) 3078 return SCTP_ERROR_RSRC_LOW; 3079 3080 /* Start the heartbeat timer. */ 3081 sctp_transport_reset_hb_timer(peer); 3082 asoc->new_transport = peer; 3083 break; 3084 case SCTP_PARAM_DEL_IP: 3085 /* ADDIP 4.3 D7) If a request is received to delete the 3086 * last remaining IP address of a peer endpoint, the receiver 3087 * MUST send an Error Cause TLV with the error cause set to the 3088 * new error code 'Request to Delete Last Remaining IP Address'. 3089 */ 3090 if (asoc->peer.transport_count == 1) 3091 return SCTP_ERROR_DEL_LAST_IP; 3092 3093 /* ADDIP 4.3 D8) If a request is received to delete an IP 3094 * address which is also the source address of the IP packet 3095 * which contained the ASCONF chunk, the receiver MUST reject 3096 * this request. To reject the request the receiver MUST send 3097 * an Error Cause TLV set to the new error code 'Request to 3098 * Delete Source IP Address' 3099 */ 3100 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3101 return SCTP_ERROR_DEL_SRC_IP; 3102 3103 /* Section 4.2.2 3104 * If the address 0.0.0.0 or ::0 is provided, all 3105 * addresses of the peer except the source address of the 3106 * packet MUST be deleted. 3107 */ 3108 if (af->is_any(&addr)) { 3109 sctp_assoc_set_primary(asoc, asconf->transport); 3110 sctp_assoc_del_nonprimary_peers(asoc, 3111 asconf->transport); 3112 return SCTP_ERROR_NO_ERROR; 3113 } 3114 3115 /* If the address is not part of the association, the 3116 * ASCONF-ACK with Error Cause Indication Parameter 3117 * which including cause of Unresolvable Address should 3118 * be sent. 3119 */ 3120 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3121 if (!peer) 3122 return SCTP_ERROR_DNS_FAILED; 3123 3124 sctp_assoc_rm_peer(asoc, peer); 3125 break; 3126 case SCTP_PARAM_SET_PRIMARY: 3127 /* ADDIP Section 4.2.4 3128 * If the address 0.0.0.0 or ::0 is provided, the receiver 3129 * MAY mark the source address of the packet as its 3130 * primary. 3131 */ 3132 if (af->is_any(&addr)) 3133 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr)); 3134 3135 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3136 if (!peer) 3137 return SCTP_ERROR_DNS_FAILED; 3138 3139 sctp_assoc_set_primary(asoc, peer); 3140 break; 3141 } 3142 3143 return SCTP_ERROR_NO_ERROR; 3144 } 3145 3146 /* Verify the ASCONF packet before we process it. */ 3147 bool sctp_verify_asconf(const struct sctp_association *asoc, 3148 struct sctp_chunk *chunk, bool addr_param_needed, 3149 struct sctp_paramhdr **errp) 3150 { 3151 struct sctp_addip_chunk *addip; 3152 bool addr_param_seen = false; 3153 union sctp_params param; 3154 3155 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr; 3156 sctp_walk_params(param, addip, addip_hdr.params) { 3157 size_t length = ntohs(param.p->length); 3158 3159 *errp = param.p; 3160 switch (param.p->type) { 3161 case SCTP_PARAM_ERR_CAUSE: 3162 break; 3163 case SCTP_PARAM_IPV4_ADDRESS: 3164 if (length != sizeof(struct sctp_ipv4addr_param)) 3165 return false; 3166 /* ensure there is only one addr param and it's in the 3167 * beginning of addip_hdr params, or we reject it. 3168 */ 3169 if (param.v != addip->addip_hdr.params) 3170 return false; 3171 addr_param_seen = true; 3172 break; 3173 case SCTP_PARAM_IPV6_ADDRESS: 3174 if (length != sizeof(struct sctp_ipv6addr_param)) 3175 return false; 3176 if (param.v != addip->addip_hdr.params) 3177 return false; 3178 addr_param_seen = true; 3179 break; 3180 case SCTP_PARAM_ADD_IP: 3181 case SCTP_PARAM_DEL_IP: 3182 case SCTP_PARAM_SET_PRIMARY: 3183 /* In ASCONF chunks, these need to be first. */ 3184 if (addr_param_needed && !addr_param_seen) 3185 return false; 3186 length = ntohs(param.addip->param_hdr.length); 3187 if (length < sizeof(struct sctp_addip_param) + 3188 sizeof(**errp)) 3189 return false; 3190 break; 3191 case SCTP_PARAM_SUCCESS_REPORT: 3192 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3193 if (length != sizeof(struct sctp_addip_param)) 3194 return false; 3195 break; 3196 default: 3197 /* This is unkown to us, reject! */ 3198 return false; 3199 } 3200 } 3201 3202 /* Remaining sanity checks. */ 3203 if (addr_param_needed && !addr_param_seen) 3204 return false; 3205 if (!addr_param_needed && addr_param_seen) 3206 return false; 3207 if (param.v != chunk->chunk_end) 3208 return false; 3209 3210 return true; 3211 } 3212 3213 /* Process an incoming ASCONF chunk with the next expected serial no. and 3214 * return an ASCONF_ACK chunk to be sent in response. 3215 */ 3216 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3217 struct sctp_chunk *asconf) 3218 { 3219 union sctp_addr_param *addr_param; 3220 struct sctp_addip_chunk *addip; 3221 struct sctp_chunk *asconf_ack; 3222 bool all_param_pass = true; 3223 struct sctp_addiphdr *hdr; 3224 int length = 0, chunk_len; 3225 union sctp_params param; 3226 __be16 err_code; 3227 __u32 serial; 3228 3229 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr; 3230 chunk_len = ntohs(asconf->chunk_hdr->length) - 3231 sizeof(struct sctp_chunkhdr); 3232 hdr = (struct sctp_addiphdr *)asconf->skb->data; 3233 serial = ntohl(hdr->serial); 3234 3235 /* Skip the addiphdr and store a pointer to address parameter. */ 3236 length = sizeof(*hdr); 3237 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3238 chunk_len -= length; 3239 3240 /* Skip the address parameter and store a pointer to the first 3241 * asconf parameter. 3242 */ 3243 length = ntohs(addr_param->p.length); 3244 chunk_len -= length; 3245 3246 /* create an ASCONF_ACK chunk. 3247 * Based on the definitions of parameters, we know that the size of 3248 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3249 * parameters. 3250 */ 3251 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3252 if (!asconf_ack) 3253 goto done; 3254 3255 /* Process the TLVs contained within the ASCONF chunk. */ 3256 sctp_walk_params(param, addip, addip_hdr.params) { 3257 /* Skip preceeding address parameters. */ 3258 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 3259 param.p->type == SCTP_PARAM_IPV6_ADDRESS) 3260 continue; 3261 3262 err_code = sctp_process_asconf_param(asoc, asconf, 3263 param.addip); 3264 /* ADDIP 4.1 A7) 3265 * If an error response is received for a TLV parameter, 3266 * all TLVs with no response before the failed TLV are 3267 * considered successful if not reported. All TLVs after 3268 * the failed response are considered unsuccessful unless 3269 * a specific success indication is present for the parameter. 3270 */ 3271 if (err_code != SCTP_ERROR_NO_ERROR) 3272 all_param_pass = false; 3273 if (!all_param_pass) 3274 sctp_add_asconf_response(asconf_ack, param.addip->crr_id, 3275 err_code, param.addip); 3276 3277 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3278 * an IP address sends an 'Out of Resource' in its response, it 3279 * MUST also fail any subsequent add or delete requests bundled 3280 * in the ASCONF. 3281 */ 3282 if (err_code == SCTP_ERROR_RSRC_LOW) 3283 goto done; 3284 } 3285 done: 3286 asoc->peer.addip_serial++; 3287 3288 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3289 * after freeing the reference to old asconf ack if any. 3290 */ 3291 if (asconf_ack) { 3292 sctp_chunk_hold(asconf_ack); 3293 list_add_tail(&asconf_ack->transmitted_list, 3294 &asoc->asconf_ack_list); 3295 } 3296 3297 return asconf_ack; 3298 } 3299 3300 /* Process a asconf parameter that is successfully acked. */ 3301 static void sctp_asconf_param_success(struct sctp_association *asoc, 3302 struct sctp_addip_param *asconf_param) 3303 { 3304 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3305 union sctp_addr_param *addr_param; 3306 struct sctp_sockaddr_entry *saddr; 3307 struct sctp_transport *transport; 3308 union sctp_addr addr; 3309 struct sctp_af *af; 3310 3311 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3312 3313 /* We have checked the packet before, so we do not check again. */ 3314 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3315 af->from_addr_param(&addr, addr_param, htons(bp->port), 0); 3316 3317 switch (asconf_param->param_hdr.type) { 3318 case SCTP_PARAM_ADD_IP: 3319 /* This is always done in BH context with a socket lock 3320 * held, so the list can not change. 3321 */ 3322 local_bh_disable(); 3323 list_for_each_entry(saddr, &bp->address_list, list) { 3324 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3325 saddr->state = SCTP_ADDR_SRC; 3326 } 3327 local_bh_enable(); 3328 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3329 transports) { 3330 sctp_transport_dst_release(transport); 3331 } 3332 break; 3333 case SCTP_PARAM_DEL_IP: 3334 local_bh_disable(); 3335 sctp_del_bind_addr(bp, &addr); 3336 if (asoc->asconf_addr_del_pending != NULL && 3337 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3338 kfree(asoc->asconf_addr_del_pending); 3339 asoc->asconf_addr_del_pending = NULL; 3340 } 3341 local_bh_enable(); 3342 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3343 transports) { 3344 sctp_transport_dst_release(transport); 3345 } 3346 break; 3347 default: 3348 break; 3349 } 3350 } 3351 3352 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3353 * for the given asconf parameter. If there is no response for this parameter, 3354 * return the error code based on the third argument 'no_err'. 3355 * ADDIP 4.1 3356 * A7) If an error response is received for a TLV parameter, all TLVs with no 3357 * response before the failed TLV are considered successful if not reported. 3358 * All TLVs after the failed response are considered unsuccessful unless a 3359 * specific success indication is present for the parameter. 3360 */ 3361 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3362 struct sctp_addip_param *asconf_param, 3363 int no_err) 3364 { 3365 struct sctp_addip_param *asconf_ack_param; 3366 struct sctp_errhdr *err_param; 3367 int asconf_ack_len; 3368 __be16 err_code; 3369 int length; 3370 3371 if (no_err) 3372 err_code = SCTP_ERROR_NO_ERROR; 3373 else 3374 err_code = SCTP_ERROR_REQ_REFUSED; 3375 3376 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3377 sizeof(struct sctp_chunkhdr); 3378 3379 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3380 * the first asconf_ack parameter. 3381 */ 3382 length = sizeof(struct sctp_addiphdr); 3383 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data + 3384 length); 3385 asconf_ack_len -= length; 3386 3387 while (asconf_ack_len > 0) { 3388 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3389 switch (asconf_ack_param->param_hdr.type) { 3390 case SCTP_PARAM_SUCCESS_REPORT: 3391 return SCTP_ERROR_NO_ERROR; 3392 case SCTP_PARAM_ERR_CAUSE: 3393 length = sizeof(*asconf_ack_param); 3394 err_param = (void *)asconf_ack_param + length; 3395 asconf_ack_len -= length; 3396 if (asconf_ack_len > 0) 3397 return err_param->cause; 3398 else 3399 return SCTP_ERROR_INV_PARAM; 3400 break; 3401 default: 3402 return SCTP_ERROR_INV_PARAM; 3403 } 3404 } 3405 3406 length = ntohs(asconf_ack_param->param_hdr.length); 3407 asconf_ack_param = (void *)asconf_ack_param + length; 3408 asconf_ack_len -= length; 3409 } 3410 3411 return err_code; 3412 } 3413 3414 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3415 int sctp_process_asconf_ack(struct sctp_association *asoc, 3416 struct sctp_chunk *asconf_ack) 3417 { 3418 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3419 struct sctp_addip_param *asconf_param; 3420 __be16 err_code = SCTP_ERROR_NO_ERROR; 3421 union sctp_addr_param *addr_param; 3422 int asconf_len = asconf->skb->len; 3423 int all_param_pass = 0; 3424 int length = 0; 3425 int no_err = 1; 3426 int retval = 0; 3427 3428 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3429 * a pointer to address parameter. 3430 */ 3431 length = sizeof(struct sctp_addip_chunk); 3432 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3433 asconf_len -= length; 3434 3435 /* Skip the address parameter in the last asconf sent and store a 3436 * pointer to the first asconf parameter. 3437 */ 3438 length = ntohs(addr_param->p.length); 3439 asconf_param = (void *)addr_param + length; 3440 asconf_len -= length; 3441 3442 /* ADDIP 4.1 3443 * A8) If there is no response(s) to specific TLV parameter(s), and no 3444 * failures are indicated, then all request(s) are considered 3445 * successful. 3446 */ 3447 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr)) 3448 all_param_pass = 1; 3449 3450 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3451 while (asconf_len > 0) { 3452 if (all_param_pass) 3453 err_code = SCTP_ERROR_NO_ERROR; 3454 else { 3455 err_code = sctp_get_asconf_response(asconf_ack, 3456 asconf_param, 3457 no_err); 3458 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3459 no_err = 0; 3460 } 3461 3462 switch (err_code) { 3463 case SCTP_ERROR_NO_ERROR: 3464 sctp_asconf_param_success(asoc, asconf_param); 3465 break; 3466 3467 case SCTP_ERROR_RSRC_LOW: 3468 retval = 1; 3469 break; 3470 3471 case SCTP_ERROR_UNKNOWN_PARAM: 3472 /* Disable sending this type of asconf parameter in 3473 * future. 3474 */ 3475 asoc->peer.addip_disabled_mask |= 3476 asconf_param->param_hdr.type; 3477 break; 3478 3479 case SCTP_ERROR_REQ_REFUSED: 3480 case SCTP_ERROR_DEL_LAST_IP: 3481 case SCTP_ERROR_DEL_SRC_IP: 3482 default: 3483 break; 3484 } 3485 3486 /* Skip the processed asconf parameter and move to the next 3487 * one. 3488 */ 3489 length = ntohs(asconf_param->param_hdr.length); 3490 asconf_param = (void *)asconf_param + length; 3491 asconf_len -= length; 3492 } 3493 3494 if (no_err && asoc->src_out_of_asoc_ok) { 3495 asoc->src_out_of_asoc_ok = 0; 3496 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3497 } 3498 3499 /* Free the cached last sent asconf chunk. */ 3500 list_del_init(&asconf->transmitted_list); 3501 sctp_chunk_free(asconf); 3502 asoc->addip_last_asconf = NULL; 3503 3504 return retval; 3505 } 3506 3507 /* Make a FWD TSN chunk. */ 3508 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3509 __u32 new_cum_tsn, size_t nstreams, 3510 struct sctp_fwdtsn_skip *skiplist) 3511 { 3512 struct sctp_chunk *retval = NULL; 3513 struct sctp_fwdtsn_hdr ftsn_hdr; 3514 struct sctp_fwdtsn_skip skip; 3515 size_t hint; 3516 int i; 3517 3518 hint = (nstreams + 1) * sizeof(__u32); 3519 3520 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC); 3521 3522 if (!retval) 3523 return NULL; 3524 3525 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3526 retval->subh.fwdtsn_hdr = 3527 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3528 3529 for (i = 0; i < nstreams; i++) { 3530 skip.stream = skiplist[i].stream; 3531 skip.ssn = skiplist[i].ssn; 3532 sctp_addto_chunk(retval, sizeof(skip), &skip); 3533 } 3534 3535 return retval; 3536 } 3537 3538 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc, 3539 __u32 new_cum_tsn, size_t nstreams, 3540 struct sctp_ifwdtsn_skip *skiplist) 3541 { 3542 struct sctp_chunk *retval = NULL; 3543 struct sctp_ifwdtsn_hdr ftsn_hdr; 3544 size_t hint; 3545 3546 hint = (nstreams + 1) * sizeof(__u32); 3547 3548 retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint, 3549 GFP_ATOMIC); 3550 if (!retval) 3551 return NULL; 3552 3553 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3554 retval->subh.ifwdtsn_hdr = 3555 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3556 3557 sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist); 3558 3559 return retval; 3560 } 3561 3562 /* RE-CONFIG 3.1 (RE-CONFIG chunk) 3563 * 0 1 2 3 3564 * 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 3565 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3566 * | Type = 130 | Chunk Flags | Chunk Length | 3567 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3568 * \ \ 3569 * / Re-configuration Parameter / 3570 * \ \ 3571 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3572 * \ \ 3573 * / Re-configuration Parameter (optional) / 3574 * \ \ 3575 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3576 */ 3577 static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc, 3578 int length) 3579 { 3580 struct sctp_reconf_chunk *reconf; 3581 struct sctp_chunk *retval; 3582 3583 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length, 3584 GFP_ATOMIC); 3585 if (!retval) 3586 return NULL; 3587 3588 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr; 3589 retval->param_hdr.v = reconf->params; 3590 3591 return retval; 3592 } 3593 3594 /* RE-CONFIG 4.1 (STREAM OUT RESET) 3595 * 0 1 2 3 3596 * 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 3597 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3598 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N | 3599 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3600 * | Re-configuration Request Sequence Number | 3601 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3602 * | Re-configuration Response Sequence Number | 3603 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3604 * | Sender's Last Assigned TSN | 3605 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3606 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3607 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3608 * / ...... / 3609 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3610 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3611 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3612 * 3613 * RE-CONFIG 4.2 (STREAM IN RESET) 3614 * 0 1 2 3 3615 * 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 3616 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3617 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N | 3618 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3619 * | Re-configuration Request Sequence Number | 3620 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3621 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3622 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3623 * / ...... / 3624 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3625 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3626 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3627 */ 3628 struct sctp_chunk *sctp_make_strreset_req( 3629 const struct sctp_association *asoc, 3630 __u16 stream_num, __be16 *stream_list, 3631 bool out, bool in) 3632 { 3633 __u16 stream_len = stream_num * sizeof(__u16); 3634 struct sctp_strreset_outreq outreq; 3635 struct sctp_strreset_inreq inreq; 3636 struct sctp_chunk *retval; 3637 __u16 outlen, inlen; 3638 3639 outlen = (sizeof(outreq) + stream_len) * out; 3640 inlen = (sizeof(inreq) + stream_len) * in; 3641 3642 retval = sctp_make_reconf(asoc, outlen + inlen); 3643 if (!retval) 3644 return NULL; 3645 3646 if (outlen) { 3647 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST; 3648 outreq.param_hdr.length = htons(outlen); 3649 outreq.request_seq = htonl(asoc->strreset_outseq); 3650 outreq.response_seq = htonl(asoc->strreset_inseq - 1); 3651 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1); 3652 3653 sctp_addto_chunk(retval, sizeof(outreq), &outreq); 3654 3655 if (stream_len) 3656 sctp_addto_chunk(retval, stream_len, stream_list); 3657 } 3658 3659 if (inlen) { 3660 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST; 3661 inreq.param_hdr.length = htons(inlen); 3662 inreq.request_seq = htonl(asoc->strreset_outseq + out); 3663 3664 sctp_addto_chunk(retval, sizeof(inreq), &inreq); 3665 3666 if (stream_len) 3667 sctp_addto_chunk(retval, stream_len, stream_list); 3668 } 3669 3670 return retval; 3671 } 3672 3673 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL) 3674 * 0 1 2 3 3675 * 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 3676 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3677 * | Parameter Type = 15 | Parameter Length = 8 | 3678 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3679 * | Re-configuration Request Sequence Number | 3680 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3681 */ 3682 struct sctp_chunk *sctp_make_strreset_tsnreq( 3683 const struct sctp_association *asoc) 3684 { 3685 struct sctp_strreset_tsnreq tsnreq; 3686 __u16 length = sizeof(tsnreq); 3687 struct sctp_chunk *retval; 3688 3689 retval = sctp_make_reconf(asoc, length); 3690 if (!retval) 3691 return NULL; 3692 3693 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST; 3694 tsnreq.param_hdr.length = htons(length); 3695 tsnreq.request_seq = htonl(asoc->strreset_outseq); 3696 3697 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq); 3698 3699 return retval; 3700 } 3701 3702 /* RE-CONFIG 4.5/4.6 (ADD STREAM) 3703 * 0 1 2 3 3704 * 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 3705 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3706 * | Parameter Type = 17 | Parameter Length = 12 | 3707 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3708 * | Re-configuration Request Sequence Number | 3709 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3710 * | Number of new streams | Reserved | 3711 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3712 */ 3713 struct sctp_chunk *sctp_make_strreset_addstrm( 3714 const struct sctp_association *asoc, 3715 __u16 out, __u16 in) 3716 { 3717 struct sctp_strreset_addstrm addstrm; 3718 __u16 size = sizeof(addstrm); 3719 struct sctp_chunk *retval; 3720 3721 retval = sctp_make_reconf(asoc, (!!out + !!in) * size); 3722 if (!retval) 3723 return NULL; 3724 3725 if (out) { 3726 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS; 3727 addstrm.param_hdr.length = htons(size); 3728 addstrm.number_of_streams = htons(out); 3729 addstrm.request_seq = htonl(asoc->strreset_outseq); 3730 addstrm.reserved = 0; 3731 3732 sctp_addto_chunk(retval, size, &addstrm); 3733 } 3734 3735 if (in) { 3736 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS; 3737 addstrm.param_hdr.length = htons(size); 3738 addstrm.number_of_streams = htons(in); 3739 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out); 3740 addstrm.reserved = 0; 3741 3742 sctp_addto_chunk(retval, size, &addstrm); 3743 } 3744 3745 return retval; 3746 } 3747 3748 /* RE-CONFIG 4.4 (RESP) 3749 * 0 1 2 3 3750 * 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 3751 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3752 * | Parameter Type = 16 | Parameter Length | 3753 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3754 * | Re-configuration Response Sequence Number | 3755 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3756 * | Result | 3757 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3758 */ 3759 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc, 3760 __u32 result, __u32 sn) 3761 { 3762 struct sctp_strreset_resp resp; 3763 __u16 length = sizeof(resp); 3764 struct sctp_chunk *retval; 3765 3766 retval = sctp_make_reconf(asoc, length); 3767 if (!retval) 3768 return NULL; 3769 3770 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3771 resp.param_hdr.length = htons(length); 3772 resp.response_seq = htonl(sn); 3773 resp.result = htonl(result); 3774 3775 sctp_addto_chunk(retval, sizeof(resp), &resp); 3776 3777 return retval; 3778 } 3779 3780 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP) 3781 * 0 1 2 3 3782 * 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 3783 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3784 * | Parameter Type = 16 | Parameter Length | 3785 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3786 * | Re-configuration Response Sequence Number | 3787 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3788 * | Result | 3789 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3790 * | Sender's Next TSN (optional) | 3791 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3792 * | Receiver's Next TSN (optional) | 3793 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3794 */ 3795 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc, 3796 __u32 result, __u32 sn, 3797 __u32 sender_tsn, 3798 __u32 receiver_tsn) 3799 { 3800 struct sctp_strreset_resptsn tsnresp; 3801 __u16 length = sizeof(tsnresp); 3802 struct sctp_chunk *retval; 3803 3804 retval = sctp_make_reconf(asoc, length); 3805 if (!retval) 3806 return NULL; 3807 3808 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3809 tsnresp.param_hdr.length = htons(length); 3810 3811 tsnresp.response_seq = htonl(sn); 3812 tsnresp.result = htonl(result); 3813 tsnresp.senders_next_tsn = htonl(sender_tsn); 3814 tsnresp.receivers_next_tsn = htonl(receiver_tsn); 3815 3816 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp); 3817 3818 return retval; 3819 } 3820 3821 bool sctp_verify_reconf(const struct sctp_association *asoc, 3822 struct sctp_chunk *chunk, 3823 struct sctp_paramhdr **errp) 3824 { 3825 struct sctp_reconf_chunk *hdr; 3826 union sctp_params param; 3827 __be16 last = 0; 3828 __u16 cnt = 0; 3829 3830 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; 3831 sctp_walk_params(param, hdr, params) { 3832 __u16 length = ntohs(param.p->length); 3833 3834 *errp = param.p; 3835 if (cnt++ > 2) 3836 return false; 3837 switch (param.p->type) { 3838 case SCTP_PARAM_RESET_OUT_REQUEST: 3839 if (length < sizeof(struct sctp_strreset_outreq) || 3840 (last && last != SCTP_PARAM_RESET_RESPONSE && 3841 last != SCTP_PARAM_RESET_IN_REQUEST)) 3842 return false; 3843 break; 3844 case SCTP_PARAM_RESET_IN_REQUEST: 3845 if (length < sizeof(struct sctp_strreset_inreq) || 3846 (last && last != SCTP_PARAM_RESET_OUT_REQUEST)) 3847 return false; 3848 break; 3849 case SCTP_PARAM_RESET_RESPONSE: 3850 if ((length != sizeof(struct sctp_strreset_resp) && 3851 length != sizeof(struct sctp_strreset_resptsn)) || 3852 (last && last != SCTP_PARAM_RESET_RESPONSE && 3853 last != SCTP_PARAM_RESET_OUT_REQUEST)) 3854 return false; 3855 break; 3856 case SCTP_PARAM_RESET_TSN_REQUEST: 3857 if (length != 3858 sizeof(struct sctp_strreset_tsnreq) || last) 3859 return false; 3860 break; 3861 case SCTP_PARAM_RESET_ADD_IN_STREAMS: 3862 if (length != sizeof(struct sctp_strreset_addstrm) || 3863 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS)) 3864 return false; 3865 break; 3866 case SCTP_PARAM_RESET_ADD_OUT_STREAMS: 3867 if (length != sizeof(struct sctp_strreset_addstrm) || 3868 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS)) 3869 return false; 3870 break; 3871 default: 3872 return false; 3873 } 3874 3875 last = param.p->type; 3876 } 3877 3878 return true; 3879 } 3880