1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* SCTP kernel implementation 3 * (C) Copyright IBM Corp. 2001, 2004 4 * Copyright (c) 1999-2000 Cisco, Inc. 5 * Copyright (c) 1999-2001 Motorola, Inc. 6 * Copyright (c) 2001-2002 Intel Corp. 7 * 8 * This file is part of the SCTP kernel implementation 9 * 10 * These functions work with the state functions in sctp_sm_statefuns.c 11 * to implement the state operations. These functions implement the 12 * steps which require modifying existing data structures. 13 * 14 * Please send any bug reports or fixes you make to the 15 * email address(es): 16 * lksctp developers <linux-sctp@vger.kernel.org> 17 * 18 * Written or modified by: 19 * La Monte H.P. Yarroll <piggy@acm.org> 20 * Karl Knutson <karl@athena.chicago.il.us> 21 * C. Robin <chris@hundredacre.ac.uk> 22 * Jon Grimm <jgrimm@us.ibm.com> 23 * Xingang Guo <xingang.guo@intel.com> 24 * Dajiang Zhang <dajiang.zhang@nokia.com> 25 * Sridhar Samudrala <sri@us.ibm.com> 26 * Daisy Chang <daisyc@us.ibm.com> 27 * Ardelle Fan <ardelle.fan@intel.com> 28 * Kevin Gao <kevin.gao@intel.com> 29 */ 30 31 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 32 33 #include <crypto/hash.h> 34 #include <linux/types.h> 35 #include <linux/kernel.h> 36 #include <linux/ip.h> 37 #include <linux/ipv6.h> 38 #include <linux/net.h> 39 #include <linux/inet.h> 40 #include <linux/scatterlist.h> 41 #include <linux/slab.h> 42 #include <net/sock.h> 43 44 #include <linux/skbuff.h> 45 #include <linux/random.h> /* for get_random_bytes */ 46 #include <net/sctp/sctp.h> 47 #include <net/sctp/sm.h> 48 49 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 50 __u8 type, __u8 flags, int paylen, 51 gfp_t gfp); 52 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 53 __u8 flags, int paylen, gfp_t gfp); 54 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 55 __u8 type, __u8 flags, int paylen, 56 gfp_t gfp); 57 static struct sctp_cookie_param *sctp_pack_cookie( 58 const struct sctp_endpoint *ep, 59 const struct sctp_association *asoc, 60 const struct sctp_chunk *init_chunk, 61 int *cookie_len, 62 const __u8 *raw_addrs, int addrs_len); 63 static int sctp_process_param(struct sctp_association *asoc, 64 union sctp_params param, 65 const union sctp_addr *peer_addr, 66 gfp_t gfp); 67 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 68 const void *data); 69 70 /* Control chunk destructor */ 71 static void sctp_control_release_owner(struct sk_buff *skb) 72 { 73 struct sctp_chunk *chunk = skb_shinfo(skb)->destructor_arg; 74 75 if (chunk->shkey) { 76 struct sctp_shared_key *shkey = chunk->shkey; 77 struct sctp_association *asoc = chunk->asoc; 78 79 /* refcnt == 2 and !list_empty mean after this release, it's 80 * not being used anywhere, and it's time to notify userland 81 * that this shkey can be freed if it's been deactivated. 82 */ 83 if (shkey->deactivated && !list_empty(&shkey->key_list) && 84 refcount_read(&shkey->refcnt) == 2) { 85 struct sctp_ulpevent *ev; 86 87 ev = sctp_ulpevent_make_authkey(asoc, shkey->key_id, 88 SCTP_AUTH_FREE_KEY, 89 GFP_KERNEL); 90 if (ev) 91 asoc->stream.si->enqueue_event(&asoc->ulpq, ev); 92 } 93 sctp_auth_shkey_release(chunk->shkey); 94 } 95 } 96 97 static void sctp_control_set_owner_w(struct sctp_chunk *chunk) 98 { 99 struct sctp_association *asoc = chunk->asoc; 100 struct sk_buff *skb = chunk->skb; 101 102 /* TODO: properly account for control chunks. 103 * To do it right we'll need: 104 * 1) endpoint if association isn't known. 105 * 2) proper memory accounting. 106 * 107 * For now don't do anything for now. 108 */ 109 if (chunk->auth) { 110 chunk->shkey = asoc->shkey; 111 sctp_auth_shkey_hold(chunk->shkey); 112 } 113 skb->sk = asoc ? asoc->base.sk : NULL; 114 skb_shinfo(skb)->destructor_arg = chunk; 115 skb->destructor = sctp_control_release_owner; 116 } 117 118 /* What was the inbound interface for this chunk? */ 119 int sctp_chunk_iif(const struct sctp_chunk *chunk) 120 { 121 struct sk_buff *skb = chunk->skb; 122 123 return SCTP_INPUT_CB(skb)->af->skb_iif(skb); 124 } 125 126 /* RFC 2960 3.3.2 Initiation (INIT) (1) 127 * 128 * Note 2: The ECN capable field is reserved for future use of 129 * Explicit Congestion Notification. 130 */ 131 static const struct sctp_paramhdr ecap_param = { 132 SCTP_PARAM_ECN_CAPABLE, 133 cpu_to_be16(sizeof(struct sctp_paramhdr)), 134 }; 135 static const struct sctp_paramhdr prsctp_param = { 136 SCTP_PARAM_FWD_TSN_SUPPORT, 137 cpu_to_be16(sizeof(struct sctp_paramhdr)), 138 }; 139 140 /* A helper to initialize an op error inside a provided chunk, as most 141 * cause codes will be embedded inside an abort chunk. 142 */ 143 int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, 144 size_t paylen) 145 { 146 struct sctp_errhdr err; 147 __u16 len; 148 149 /* Cause code constants are now defined in network order. */ 150 err.cause = cause_code; 151 len = sizeof(err) + paylen; 152 err.length = htons(len); 153 154 if (skb_tailroom(chunk->skb) < len) 155 return -ENOSPC; 156 157 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(err), &err); 158 159 return 0; 160 } 161 162 /* 3.3.2 Initiation (INIT) (1) 163 * 164 * This chunk is used to initiate a SCTP association between two 165 * endpoints. The format of the INIT chunk is shown below: 166 * 167 * 0 1 2 3 168 * 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 1 169 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 170 * | Type = 1 | Chunk Flags | Chunk Length | 171 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 172 * | Initiate Tag | 173 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 174 * | Advertised Receiver Window Credit (a_rwnd) | 175 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 176 * | Number of Outbound Streams | Number of Inbound Streams | 177 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 178 * | Initial TSN | 179 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 180 * \ \ 181 * / Optional/Variable-Length Parameters / 182 * \ \ 183 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 184 * 185 * 186 * The INIT chunk contains the following parameters. Unless otherwise 187 * noted, each parameter MUST only be included once in the INIT chunk. 188 * 189 * Fixed Parameters Status 190 * ---------------------------------------------- 191 * Initiate Tag Mandatory 192 * Advertised Receiver Window Credit Mandatory 193 * Number of Outbound Streams Mandatory 194 * Number of Inbound Streams Mandatory 195 * Initial TSN Mandatory 196 * 197 * Variable Parameters Status Type Value 198 * ------------------------------------------------------------- 199 * IPv4 Address (Note 1) Optional 5 200 * IPv6 Address (Note 1) Optional 6 201 * Cookie Preservative Optional 9 202 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000) 203 * Host Name Address (Note 3) Optional 11 204 * Supported Address Types (Note 4) Optional 12 205 */ 206 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc, 207 const struct sctp_bind_addr *bp, 208 gfp_t gfp, int vparam_len) 209 { 210 struct sctp_supported_ext_param ext_param; 211 struct sctp_adaptation_ind_param aiparam; 212 struct sctp_paramhdr *auth_chunks = NULL; 213 struct sctp_paramhdr *auth_hmacs = NULL; 214 struct sctp_supported_addrs_param sat; 215 struct sctp_endpoint *ep = asoc->ep; 216 struct sctp_chunk *retval = NULL; 217 int num_types, addrs_len = 0; 218 struct sctp_inithdr init; 219 union sctp_params addrs; 220 struct sctp_sock *sp; 221 __u8 extensions[5]; 222 size_t chunksize; 223 __be16 types[2]; 224 int num_ext = 0; 225 226 /* RFC 2960 3.3.2 Initiation (INIT) (1) 227 * 228 * Note 1: The INIT chunks can contain multiple addresses that 229 * can be IPv4 and/or IPv6 in any combination. 230 */ 231 232 /* Convert the provided bind address list to raw format. */ 233 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp); 234 235 init.init_tag = htonl(asoc->c.my_vtag); 236 init.a_rwnd = htonl(asoc->rwnd); 237 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 238 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 239 init.initial_tsn = htonl(asoc->c.initial_tsn); 240 241 /* How many address types are needed? */ 242 sp = sctp_sk(asoc->base.sk); 243 num_types = sp->pf->supported_addrs(sp, types); 244 245 chunksize = sizeof(init) + addrs_len; 246 chunksize += SCTP_PAD4(SCTP_SAT_LEN(num_types)); 247 248 if (asoc->ep->ecn_enable) 249 chunksize += sizeof(ecap_param); 250 251 if (asoc->ep->prsctp_enable) 252 chunksize += sizeof(prsctp_param); 253 254 /* ADDIP: Section 4.2.7: 255 * An implementation supporting this extension [ADDIP] MUST list 256 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and 257 * INIT-ACK parameters. 258 */ 259 if (asoc->ep->asconf_enable) { 260 extensions[num_ext] = SCTP_CID_ASCONF; 261 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 262 num_ext += 2; 263 } 264 265 if (asoc->ep->reconf_enable) { 266 extensions[num_ext] = SCTP_CID_RECONF; 267 num_ext += 1; 268 } 269 270 if (sp->adaptation_ind) 271 chunksize += sizeof(aiparam); 272 273 if (asoc->ep->intl_enable) { 274 extensions[num_ext] = SCTP_CID_I_DATA; 275 num_ext += 1; 276 } 277 278 chunksize += vparam_len; 279 280 /* Account for AUTH related parameters */ 281 if (ep->auth_enable) { 282 /* Add random parameter length*/ 283 chunksize += sizeof(asoc->c.auth_random); 284 285 /* Add HMACS parameter length if any were defined */ 286 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; 287 if (auth_hmacs->length) 288 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 289 else 290 auth_hmacs = NULL; 291 292 /* Add CHUNKS parameter length */ 293 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; 294 if (auth_chunks->length) 295 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 296 else 297 auth_chunks = NULL; 298 299 extensions[num_ext] = SCTP_CID_AUTH; 300 num_ext += 1; 301 } 302 303 /* If we have any extensions to report, account for that */ 304 if (num_ext) 305 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext); 306 307 /* RFC 2960 3.3.2 Initiation (INIT) (1) 308 * 309 * Note 3: An INIT chunk MUST NOT contain more than one Host 310 * Name address parameter. Moreover, the sender of the INIT 311 * MUST NOT combine any other address types with the Host Name 312 * address in the INIT. The receiver of INIT MUST ignore any 313 * other address types if the Host Name address parameter is 314 * present in the received INIT chunk. 315 * 316 * PLEASE DO NOT FIXME [This version does not support Host Name.] 317 */ 318 319 retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp); 320 if (!retval) 321 goto nodata; 322 323 retval->subh.init_hdr = 324 sctp_addto_chunk(retval, sizeof(init), &init); 325 retval->param_hdr.v = 326 sctp_addto_chunk(retval, addrs_len, addrs.v); 327 328 /* RFC 2960 3.3.2 Initiation (INIT) (1) 329 * 330 * Note 4: This parameter, when present, specifies all the 331 * address types the sending endpoint can support. The absence 332 * of this parameter indicates that the sending endpoint can 333 * support any address type. 334 */ 335 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES; 336 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types)); 337 sctp_addto_chunk(retval, sizeof(sat), &sat); 338 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types); 339 340 if (asoc->ep->ecn_enable) 341 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 342 343 /* Add the supported extensions parameter. Be nice and add this 344 * fist before addiding the parameters for the extensions themselves 345 */ 346 if (num_ext) { 347 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 348 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext); 349 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); 350 sctp_addto_param(retval, num_ext, extensions); 351 } 352 353 if (asoc->ep->prsctp_enable) 354 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 355 356 if (sp->adaptation_ind) { 357 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 358 aiparam.param_hdr.length = htons(sizeof(aiparam)); 359 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 360 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 361 } 362 363 /* Add SCTP-AUTH chunks to the parameter list */ 364 if (ep->auth_enable) { 365 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random), 366 asoc->c.auth_random); 367 if (auth_hmacs) 368 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 369 auth_hmacs); 370 if (auth_chunks) 371 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 372 auth_chunks); 373 } 374 nodata: 375 kfree(addrs.v); 376 return retval; 377 } 378 379 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, 380 const struct sctp_chunk *chunk, 381 gfp_t gfp, int unkparam_len) 382 { 383 struct sctp_supported_ext_param ext_param; 384 struct sctp_adaptation_ind_param aiparam; 385 struct sctp_paramhdr *auth_chunks = NULL; 386 struct sctp_paramhdr *auth_random = NULL; 387 struct sctp_paramhdr *auth_hmacs = NULL; 388 struct sctp_chunk *retval = NULL; 389 struct sctp_cookie_param *cookie; 390 struct sctp_inithdr initack; 391 union sctp_params addrs; 392 struct sctp_sock *sp; 393 __u8 extensions[5]; 394 size_t chunksize; 395 int num_ext = 0; 396 int cookie_len; 397 int addrs_len; 398 399 /* Note: there may be no addresses to embed. */ 400 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp); 401 402 initack.init_tag = htonl(asoc->c.my_vtag); 403 initack.a_rwnd = htonl(asoc->rwnd); 404 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 405 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 406 initack.initial_tsn = htonl(asoc->c.initial_tsn); 407 408 /* FIXME: We really ought to build the cookie right 409 * into the packet instead of allocating more fresh memory. 410 */ 411 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len, 412 addrs.v, addrs_len); 413 if (!cookie) 414 goto nomem_cookie; 415 416 /* Calculate the total size of allocation, include the reserved 417 * space for reporting unknown parameters if it is specified. 418 */ 419 sp = sctp_sk(asoc->base.sk); 420 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len; 421 422 /* Tell peer that we'll do ECN only if peer advertised such cap. */ 423 if (asoc->peer.ecn_capable) 424 chunksize += sizeof(ecap_param); 425 426 if (asoc->peer.prsctp_capable) 427 chunksize += sizeof(prsctp_param); 428 429 if (asoc->peer.asconf_capable) { 430 extensions[num_ext] = SCTP_CID_ASCONF; 431 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 432 num_ext += 2; 433 } 434 435 if (asoc->peer.reconf_capable) { 436 extensions[num_ext] = SCTP_CID_RECONF; 437 num_ext += 1; 438 } 439 440 if (sp->adaptation_ind) 441 chunksize += sizeof(aiparam); 442 443 if (asoc->peer.intl_capable) { 444 extensions[num_ext] = SCTP_CID_I_DATA; 445 num_ext += 1; 446 } 447 448 if (asoc->peer.auth_capable) { 449 auth_random = (struct sctp_paramhdr *)asoc->c.auth_random; 450 chunksize += ntohs(auth_random->length); 451 452 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; 453 if (auth_hmacs->length) 454 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 455 else 456 auth_hmacs = NULL; 457 458 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; 459 if (auth_chunks->length) 460 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 461 else 462 auth_chunks = NULL; 463 464 extensions[num_ext] = SCTP_CID_AUTH; 465 num_ext += 1; 466 } 467 468 if (num_ext) 469 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext); 470 471 /* Now allocate and fill out the chunk. */ 472 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp); 473 if (!retval) 474 goto nomem_chunk; 475 476 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 477 * 478 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 479 * HEARTBEAT ACK, * etc.) to the same destination transport 480 * address from which it received the DATA or control chunk 481 * to which it is replying. 482 * 483 * [INIT ACK back to where the INIT came from.] 484 */ 485 if (chunk->transport) 486 retval->transport = 487 sctp_assoc_lookup_paddr(asoc, 488 &chunk->transport->ipaddr); 489 490 retval->subh.init_hdr = 491 sctp_addto_chunk(retval, sizeof(initack), &initack); 492 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); 493 sctp_addto_chunk(retval, cookie_len, cookie); 494 if (asoc->peer.ecn_capable) 495 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 496 if (num_ext) { 497 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 498 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext); 499 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); 500 sctp_addto_param(retval, num_ext, extensions); 501 } 502 if (asoc->peer.prsctp_capable) 503 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 504 505 if (sp->adaptation_ind) { 506 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 507 aiparam.param_hdr.length = htons(sizeof(aiparam)); 508 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 509 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 510 } 511 512 if (asoc->peer.auth_capable) { 513 sctp_addto_chunk(retval, ntohs(auth_random->length), 514 auth_random); 515 if (auth_hmacs) 516 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 517 auth_hmacs); 518 if (auth_chunks) 519 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 520 auth_chunks); 521 } 522 523 /* We need to remove the const qualifier at this point. */ 524 retval->asoc = (struct sctp_association *) asoc; 525 526 nomem_chunk: 527 kfree(cookie); 528 nomem_cookie: 529 kfree(addrs.v); 530 return retval; 531 } 532 533 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10): 534 * 535 * This chunk is used only during the initialization of an association. 536 * It is sent by the initiator of an association to its peer to complete 537 * the initialization process. This chunk MUST precede any DATA chunk 538 * sent within the association, but MAY be bundled with one or more DATA 539 * chunks in the same packet. 540 * 541 * 0 1 2 3 542 * 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 1 543 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 544 * | Type = 10 |Chunk Flags | Length | 545 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 546 * / Cookie / 547 * \ \ 548 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 549 * 550 * Chunk Flags: 8 bit 551 * 552 * Set to zero on transmit and ignored on receipt. 553 * 554 * Length: 16 bits (unsigned integer) 555 * 556 * Set to the size of the chunk in bytes, including the 4 bytes of 557 * the chunk header and the size of the Cookie. 558 * 559 * Cookie: variable size 560 * 561 * This field must contain the exact cookie received in the 562 * State Cookie parameter from the previous INIT ACK. 563 * 564 * An implementation SHOULD make the cookie as small as possible 565 * to insure interoperability. 566 */ 567 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, 568 const struct sctp_chunk *chunk) 569 { 570 struct sctp_chunk *retval; 571 int cookie_len; 572 void *cookie; 573 574 cookie = asoc->peer.cookie; 575 cookie_len = asoc->peer.cookie_len; 576 577 /* Build a cookie echo chunk. */ 578 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0, 579 cookie_len, GFP_ATOMIC); 580 if (!retval) 581 goto nodata; 582 retval->subh.cookie_hdr = 583 sctp_addto_chunk(retval, cookie_len, cookie); 584 585 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 586 * 587 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 588 * HEARTBEAT ACK, * etc.) to the same destination transport 589 * address from which it * received the DATA or control chunk 590 * to which it is replying. 591 * 592 * [COOKIE ECHO back to where the INIT ACK came from.] 593 */ 594 if (chunk) 595 retval->transport = chunk->transport; 596 597 nodata: 598 return retval; 599 } 600 601 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11): 602 * 603 * This chunk is used only during the initialization of an 604 * association. It is used to acknowledge the receipt of a COOKIE 605 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent 606 * within the association, but MAY be bundled with one or more DATA 607 * chunks or SACK chunk in the same SCTP packet. 608 * 609 * 0 1 2 3 610 * 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 1 611 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 612 * | Type = 11 |Chunk Flags | Length = 4 | 613 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 614 * 615 * Chunk Flags: 8 bits 616 * 617 * Set to zero on transmit and ignored on receipt. 618 */ 619 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, 620 const struct sctp_chunk *chunk) 621 { 622 struct sctp_chunk *retval; 623 624 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC); 625 626 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 627 * 628 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 629 * HEARTBEAT ACK, * etc.) to the same destination transport 630 * address from which it * received the DATA or control chunk 631 * to which it is replying. 632 * 633 * [COOKIE ACK back to where the COOKIE ECHO came from.] 634 */ 635 if (retval && chunk && chunk->transport) 636 retval->transport = 637 sctp_assoc_lookup_paddr(asoc, 638 &chunk->transport->ipaddr); 639 640 return retval; 641 } 642 643 /* 644 * Appendix A: Explicit Congestion Notification: 645 * CWR: 646 * 647 * RFC 2481 details a specific bit for a sender to send in the header of 648 * its next outbound TCP segment to indicate to its peer that it has 649 * reduced its congestion window. This is termed the CWR bit. For 650 * SCTP the same indication is made by including the CWR chunk. 651 * This chunk contains one data element, i.e. the TSN number that 652 * was sent in the ECNE chunk. This element represents the lowest 653 * TSN number in the datagram that was originally marked with the 654 * CE bit. 655 * 656 * 0 1 2 3 657 * 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 1 658 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 659 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 | 660 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 661 * | Lowest TSN Number | 662 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 663 * 664 * Note: The CWR is considered a Control chunk. 665 */ 666 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, 667 const __u32 lowest_tsn, 668 const struct sctp_chunk *chunk) 669 { 670 struct sctp_chunk *retval; 671 struct sctp_cwrhdr cwr; 672 673 cwr.lowest_tsn = htonl(lowest_tsn); 674 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0, 675 sizeof(cwr), GFP_ATOMIC); 676 677 if (!retval) 678 goto nodata; 679 680 retval->subh.ecn_cwr_hdr = 681 sctp_addto_chunk(retval, sizeof(cwr), &cwr); 682 683 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 684 * 685 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 686 * HEARTBEAT ACK, * etc.) to the same destination transport 687 * address from which it * received the DATA or control chunk 688 * to which it is replying. 689 * 690 * [Report a reduced congestion window back to where the ECNE 691 * came from.] 692 */ 693 if (chunk) 694 retval->transport = chunk->transport; 695 696 nodata: 697 return retval; 698 } 699 700 /* Make an ECNE chunk. This is a congestion experienced report. */ 701 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, 702 const __u32 lowest_tsn) 703 { 704 struct sctp_chunk *retval; 705 struct sctp_ecnehdr ecne; 706 707 ecne.lowest_tsn = htonl(lowest_tsn); 708 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0, 709 sizeof(ecne), GFP_ATOMIC); 710 if (!retval) 711 goto nodata; 712 retval->subh.ecne_hdr = 713 sctp_addto_chunk(retval, sizeof(ecne), &ecne); 714 715 nodata: 716 return retval; 717 } 718 719 /* Make a DATA chunk for the given association from the provided 720 * parameters. However, do not populate the data payload. 721 */ 722 struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc, 723 const struct sctp_sndrcvinfo *sinfo, 724 int len, __u8 flags, gfp_t gfp) 725 { 726 struct sctp_chunk *retval; 727 struct sctp_datahdr dp; 728 729 /* We assign the TSN as LATE as possible, not here when 730 * creating the chunk. 731 */ 732 memset(&dp, 0, sizeof(dp)); 733 dp.ppid = sinfo->sinfo_ppid; 734 dp.stream = htons(sinfo->sinfo_stream); 735 736 /* Set the flags for an unordered send. */ 737 if (sinfo->sinfo_flags & SCTP_UNORDERED) 738 flags |= SCTP_DATA_UNORDERED; 739 740 retval = sctp_make_data(asoc, flags, sizeof(dp) + len, gfp); 741 if (!retval) 742 return NULL; 743 744 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp); 745 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo)); 746 747 return retval; 748 } 749 750 /* Create a selective ackowledgement (SACK) for the given 751 * association. This reports on which TSN's we've seen to date, 752 * including duplicates and gaps. 753 */ 754 struct sctp_chunk *sctp_make_sack(struct sctp_association *asoc) 755 { 756 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; 757 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; 758 __u16 num_gabs, num_dup_tsns; 759 struct sctp_transport *trans; 760 struct sctp_chunk *retval; 761 struct sctp_sackhdr sack; 762 __u32 ctsn; 763 int len; 764 765 memset(gabs, 0, sizeof(gabs)); 766 ctsn = sctp_tsnmap_get_ctsn(map); 767 768 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn); 769 770 /* How much room is needed in the chunk? */ 771 num_gabs = sctp_tsnmap_num_gabs(map, gabs); 772 num_dup_tsns = sctp_tsnmap_num_dups(map); 773 774 /* Initialize the SACK header. */ 775 sack.cum_tsn_ack = htonl(ctsn); 776 sack.a_rwnd = htonl(asoc->a_rwnd); 777 sack.num_gap_ack_blocks = htons(num_gabs); 778 sack.num_dup_tsns = htons(num_dup_tsns); 779 780 len = sizeof(sack) 781 + sizeof(struct sctp_gap_ack_block) * num_gabs 782 + sizeof(__u32) * num_dup_tsns; 783 784 /* Create the chunk. */ 785 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC); 786 if (!retval) 787 goto nodata; 788 789 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 790 * 791 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 792 * HEARTBEAT ACK, etc.) to the same destination transport 793 * address from which it received the DATA or control chunk to 794 * which it is replying. This rule should also be followed if 795 * the endpoint is bundling DATA chunks together with the 796 * reply chunk. 797 * 798 * However, when acknowledging multiple DATA chunks received 799 * in packets from different source addresses in a single 800 * SACK, the SACK chunk may be transmitted to one of the 801 * destination transport addresses from which the DATA or 802 * control chunks being acknowledged were received. 803 * 804 * [BUG: We do not implement the following paragraph. 805 * Perhaps we should remember the last transport we used for a 806 * SACK and avoid that (if possible) if we have seen any 807 * duplicates. --piggy] 808 * 809 * When a receiver of a duplicate DATA chunk sends a SACK to a 810 * multi- homed endpoint it MAY be beneficial to vary the 811 * destination address and not use the source address of the 812 * DATA chunk. The reason being that receiving a duplicate 813 * from a multi-homed endpoint might indicate that the return 814 * path (as specified in the source address of the DATA chunk) 815 * for the SACK is broken. 816 * 817 * [Send to the address from which we last received a DATA chunk.] 818 */ 819 retval->transport = asoc->peer.last_data_from; 820 821 retval->subh.sack_hdr = 822 sctp_addto_chunk(retval, sizeof(sack), &sack); 823 824 /* Add the gap ack block information. */ 825 if (num_gabs) 826 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, 827 gabs); 828 829 /* Add the duplicate TSN information. */ 830 if (num_dup_tsns) { 831 asoc->stats.idupchunks += num_dup_tsns; 832 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, 833 sctp_tsnmap_get_dups(map)); 834 } 835 /* Once we have a sack generated, check to see what our sack 836 * generation is, if its 0, reset the transports to 0, and reset 837 * the association generation to 1 838 * 839 * The idea is that zero is never used as a valid generation for the 840 * association so no transport will match after a wrap event like this, 841 * Until the next sack 842 */ 843 if (++asoc->peer.sack_generation == 0) { 844 list_for_each_entry(trans, &asoc->peer.transport_addr_list, 845 transports) 846 trans->sack_generation = 0; 847 asoc->peer.sack_generation = 1; 848 } 849 nodata: 850 return retval; 851 } 852 853 /* Make a SHUTDOWN chunk. */ 854 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 855 const struct sctp_chunk *chunk) 856 { 857 struct sctp_shutdownhdr shut; 858 struct sctp_chunk *retval; 859 __u32 ctsn; 860 861 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 862 shut.cum_tsn_ack = htonl(ctsn); 863 864 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0, 865 sizeof(shut), GFP_ATOMIC); 866 if (!retval) 867 goto nodata; 868 869 retval->subh.shutdown_hdr = 870 sctp_addto_chunk(retval, sizeof(shut), &shut); 871 872 if (chunk) 873 retval->transport = chunk->transport; 874 nodata: 875 return retval; 876 } 877 878 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 879 const struct sctp_chunk *chunk) 880 { 881 struct sctp_chunk *retval; 882 883 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0, 884 GFP_ATOMIC); 885 886 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 887 * 888 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 889 * HEARTBEAT ACK, * etc.) to the same destination transport 890 * address from which it * received the DATA or control chunk 891 * to which it is replying. 892 * 893 * [ACK back to where the SHUTDOWN came from.] 894 */ 895 if (retval && chunk) 896 retval->transport = chunk->transport; 897 898 return retval; 899 } 900 901 struct sctp_chunk *sctp_make_shutdown_complete( 902 const struct sctp_association *asoc, 903 const struct sctp_chunk *chunk) 904 { 905 struct sctp_chunk *retval; 906 __u8 flags = 0; 907 908 /* Set the T-bit if we have no association (vtag will be 909 * reflected) 910 */ 911 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; 912 913 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 914 0, GFP_ATOMIC); 915 916 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 917 * 918 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 919 * HEARTBEAT ACK, * etc.) to the same destination transport 920 * address from which it * received the DATA or control chunk 921 * to which it is replying. 922 * 923 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK 924 * came from.] 925 */ 926 if (retval && chunk) 927 retval->transport = chunk->transport; 928 929 return retval; 930 } 931 932 /* Create an ABORT. Note that we set the T bit if we have no 933 * association, except when responding to an INIT (sctpimpguide 2.41). 934 */ 935 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 936 const struct sctp_chunk *chunk, 937 const size_t hint) 938 { 939 struct sctp_chunk *retval; 940 __u8 flags = 0; 941 942 /* Set the T-bit if we have no association and 'chunk' is not 943 * an INIT (vtag will be reflected). 944 */ 945 if (!asoc) { 946 if (chunk && chunk->chunk_hdr && 947 chunk->chunk_hdr->type == SCTP_CID_INIT) 948 flags = 0; 949 else 950 flags = SCTP_CHUNK_FLAG_T; 951 } 952 953 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint, 954 GFP_ATOMIC); 955 956 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 957 * 958 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 959 * HEARTBEAT ACK, * etc.) to the same destination transport 960 * address from which it * received the DATA or control chunk 961 * to which it is replying. 962 * 963 * [ABORT back to where the offender came from.] 964 */ 965 if (retval && chunk) 966 retval->transport = chunk->transport; 967 968 return retval; 969 } 970 971 /* Helper to create ABORT with a NO_USER_DATA error. */ 972 struct sctp_chunk *sctp_make_abort_no_data( 973 const struct sctp_association *asoc, 974 const struct sctp_chunk *chunk, 975 __u32 tsn) 976 { 977 struct sctp_chunk *retval; 978 __be32 payload; 979 980 retval = sctp_make_abort(asoc, chunk, 981 sizeof(struct sctp_errhdr) + sizeof(tsn)); 982 983 if (!retval) 984 goto no_mem; 985 986 /* Put the tsn back into network byte order. */ 987 payload = htonl(tsn); 988 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload)); 989 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload); 990 991 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 992 * 993 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 994 * HEARTBEAT ACK, * etc.) to the same destination transport 995 * address from which it * received the DATA or control chunk 996 * to which it is replying. 997 * 998 * [ABORT back to where the offender came from.] 999 */ 1000 if (chunk) 1001 retval->transport = chunk->transport; 1002 1003 no_mem: 1004 return retval; 1005 } 1006 1007 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ 1008 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 1009 struct msghdr *msg, 1010 size_t paylen) 1011 { 1012 struct sctp_chunk *retval; 1013 void *payload = NULL; 1014 int err; 1015 1016 retval = sctp_make_abort(asoc, NULL, 1017 sizeof(struct sctp_errhdr) + paylen); 1018 if (!retval) 1019 goto err_chunk; 1020 1021 if (paylen) { 1022 /* Put the msg_iov together into payload. */ 1023 payload = kmalloc(paylen, GFP_KERNEL); 1024 if (!payload) 1025 goto err_payload; 1026 1027 err = memcpy_from_msg(payload, msg, paylen); 1028 if (err < 0) 1029 goto err_copy; 1030 } 1031 1032 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); 1033 sctp_addto_chunk(retval, paylen, payload); 1034 1035 if (paylen) 1036 kfree(payload); 1037 1038 return retval; 1039 1040 err_copy: 1041 kfree(payload); 1042 err_payload: 1043 sctp_chunk_free(retval); 1044 retval = NULL; 1045 err_chunk: 1046 return retval; 1047 } 1048 1049 /* Append bytes to the end of a parameter. Will panic if chunk is not big 1050 * enough. 1051 */ 1052 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 1053 const void *data) 1054 { 1055 int chunklen = ntohs(chunk->chunk_hdr->length); 1056 void *target; 1057 1058 target = skb_put(chunk->skb, len); 1059 1060 if (data) 1061 memcpy(target, data, len); 1062 else 1063 memset(target, 0, len); 1064 1065 /* Adjust the chunk length field. */ 1066 chunk->chunk_hdr->length = htons(chunklen + len); 1067 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1068 1069 return target; 1070 } 1071 1072 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ 1073 struct sctp_chunk *sctp_make_abort_violation( 1074 const struct sctp_association *asoc, 1075 const struct sctp_chunk *chunk, 1076 const __u8 *payload, 1077 const size_t paylen) 1078 { 1079 struct sctp_chunk *retval; 1080 struct sctp_paramhdr phdr; 1081 1082 retval = sctp_make_abort(asoc, chunk, sizeof(struct sctp_errhdr) + 1083 paylen + sizeof(phdr)); 1084 if (!retval) 1085 goto end; 1086 1087 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen + 1088 sizeof(phdr)); 1089 1090 phdr.type = htons(chunk->chunk_hdr->type); 1091 phdr.length = chunk->chunk_hdr->length; 1092 sctp_addto_chunk(retval, paylen, payload); 1093 sctp_addto_param(retval, sizeof(phdr), &phdr); 1094 1095 end: 1096 return retval; 1097 } 1098 1099 struct sctp_chunk *sctp_make_violation_paramlen( 1100 const struct sctp_association *asoc, 1101 const struct sctp_chunk *chunk, 1102 struct sctp_paramhdr *param) 1103 { 1104 static const char error[] = "The following parameter had invalid length:"; 1105 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr) + 1106 sizeof(*param); 1107 struct sctp_chunk *retval; 1108 1109 retval = sctp_make_abort(asoc, chunk, payload_len); 1110 if (!retval) 1111 goto nodata; 1112 1113 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, 1114 sizeof(error) + sizeof(*param)); 1115 sctp_addto_chunk(retval, sizeof(error), error); 1116 sctp_addto_param(retval, sizeof(*param), param); 1117 1118 nodata: 1119 return retval; 1120 } 1121 1122 struct sctp_chunk *sctp_make_violation_max_retrans( 1123 const struct sctp_association *asoc, 1124 const struct sctp_chunk *chunk) 1125 { 1126 static const char error[] = "Association exceeded its max_retrans count"; 1127 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr); 1128 struct sctp_chunk *retval; 1129 1130 retval = sctp_make_abort(asoc, chunk, payload_len); 1131 if (!retval) 1132 goto nodata; 1133 1134 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error)); 1135 sctp_addto_chunk(retval, sizeof(error), error); 1136 1137 nodata: 1138 return retval; 1139 } 1140 1141 /* Make a HEARTBEAT chunk. */ 1142 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1143 const struct sctp_transport *transport) 1144 { 1145 struct sctp_sender_hb_info hbinfo; 1146 struct sctp_chunk *retval; 1147 1148 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, 1149 sizeof(hbinfo), GFP_ATOMIC); 1150 1151 if (!retval) 1152 goto nodata; 1153 1154 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; 1155 hbinfo.param_hdr.length = htons(sizeof(hbinfo)); 1156 hbinfo.daddr = transport->ipaddr; 1157 hbinfo.sent_at = jiffies; 1158 hbinfo.hb_nonce = transport->hb_nonce; 1159 1160 /* Cast away the 'const', as this is just telling the chunk 1161 * what transport it belongs to. 1162 */ 1163 retval->transport = (struct sctp_transport *) transport; 1164 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo), 1165 &hbinfo); 1166 1167 nodata: 1168 return retval; 1169 } 1170 1171 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1172 const struct sctp_chunk *chunk, 1173 const void *payload, 1174 const size_t paylen) 1175 { 1176 struct sctp_chunk *retval; 1177 1178 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen, 1179 GFP_ATOMIC); 1180 if (!retval) 1181 goto nodata; 1182 1183 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1184 1185 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1186 * 1187 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1188 * HEARTBEAT ACK, * etc.) to the same destination transport 1189 * address from which it * received the DATA or control chunk 1190 * to which it is replying. 1191 * 1192 * [HBACK back to where the HEARTBEAT came from.] 1193 */ 1194 if (chunk) 1195 retval->transport = chunk->transport; 1196 1197 nodata: 1198 return retval; 1199 } 1200 1201 /* Create an Operation Error chunk with the specified space reserved. 1202 * This routine can be used for containing multiple causes in the chunk. 1203 */ 1204 static struct sctp_chunk *sctp_make_op_error_space( 1205 const struct sctp_association *asoc, 1206 const struct sctp_chunk *chunk, 1207 size_t size) 1208 { 1209 struct sctp_chunk *retval; 1210 1211 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0, 1212 sizeof(struct sctp_errhdr) + size, 1213 GFP_ATOMIC); 1214 if (!retval) 1215 goto nodata; 1216 1217 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1218 * 1219 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1220 * HEARTBEAT ACK, etc.) to the same destination transport 1221 * address from which it received the DATA or control chunk 1222 * to which it is replying. 1223 * 1224 */ 1225 if (chunk) 1226 retval->transport = chunk->transport; 1227 1228 nodata: 1229 return retval; 1230 } 1231 1232 /* Create an Operation Error chunk of a fixed size, specifically, 1233 * min(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) - overheads. 1234 * This is a helper function to allocate an error chunk for for those 1235 * invalid parameter codes in which we may not want to report all the 1236 * errors, if the incoming chunk is large. If it can't fit in a single 1237 * packet, we ignore it. 1238 */ 1239 static inline struct sctp_chunk *sctp_make_op_error_limited( 1240 const struct sctp_association *asoc, 1241 const struct sctp_chunk *chunk) 1242 { 1243 size_t size = SCTP_DEFAULT_MAXSEGMENT; 1244 struct sctp_sock *sp = NULL; 1245 1246 if (asoc) { 1247 size = min_t(size_t, size, asoc->pathmtu); 1248 sp = sctp_sk(asoc->base.sk); 1249 } 1250 1251 size = sctp_mtu_payload(sp, size, sizeof(struct sctp_errhdr)); 1252 1253 return sctp_make_op_error_space(asoc, chunk, size); 1254 } 1255 1256 /* Create an Operation Error chunk. */ 1257 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1258 const struct sctp_chunk *chunk, 1259 __be16 cause_code, const void *payload, 1260 size_t paylen, size_t reserve_tail) 1261 { 1262 struct sctp_chunk *retval; 1263 1264 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); 1265 if (!retval) 1266 goto nodata; 1267 1268 sctp_init_cause(retval, cause_code, paylen + reserve_tail); 1269 sctp_addto_chunk(retval, paylen, payload); 1270 if (reserve_tail) 1271 sctp_addto_param(retval, reserve_tail, NULL); 1272 1273 nodata: 1274 return retval; 1275 } 1276 1277 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc, 1278 __u16 key_id) 1279 { 1280 struct sctp_authhdr auth_hdr; 1281 struct sctp_hmac *hmac_desc; 1282 struct sctp_chunk *retval; 1283 1284 /* Get the first hmac that the peer told us to use */ 1285 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1286 if (unlikely(!hmac_desc)) 1287 return NULL; 1288 1289 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0, 1290 hmac_desc->hmac_len + sizeof(auth_hdr), 1291 GFP_ATOMIC); 1292 if (!retval) 1293 return NULL; 1294 1295 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1296 auth_hdr.shkey_id = htons(key_id); 1297 1298 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr), 1299 &auth_hdr); 1300 1301 skb_put_zero(retval->skb, hmac_desc->hmac_len); 1302 1303 /* Adjust the chunk header to include the empty MAC */ 1304 retval->chunk_hdr->length = 1305 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1306 retval->chunk_end = skb_tail_pointer(retval->skb); 1307 1308 return retval; 1309 } 1310 1311 1312 /******************************************************************** 1313 * 2nd Level Abstractions 1314 ********************************************************************/ 1315 1316 /* Turn an skb into a chunk. 1317 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1318 * 1319 * sctpimpguide-05.txt Section 2.8.2 1320 * M1) Each time a new DATA chunk is transmitted 1321 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1322 * 'TSN.Missing.Report' count will be used to determine missing chunks 1323 * and when to fast retransmit. 1324 * 1325 */ 1326 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1327 const struct sctp_association *asoc, 1328 struct sock *sk, gfp_t gfp) 1329 { 1330 struct sctp_chunk *retval; 1331 1332 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp); 1333 1334 if (!retval) 1335 goto nodata; 1336 if (!sk) 1337 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb); 1338 1339 INIT_LIST_HEAD(&retval->list); 1340 retval->skb = skb; 1341 retval->asoc = (struct sctp_association *)asoc; 1342 retval->singleton = 1; 1343 1344 retval->fast_retransmit = SCTP_CAN_FRTX; 1345 1346 /* Polish the bead hole. */ 1347 INIT_LIST_HEAD(&retval->transmitted_list); 1348 INIT_LIST_HEAD(&retval->frag_list); 1349 SCTP_DBG_OBJCNT_INC(chunk); 1350 refcount_set(&retval->refcnt, 1); 1351 1352 nodata: 1353 return retval; 1354 } 1355 1356 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1357 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1358 union sctp_addr *dest) 1359 { 1360 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1361 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1362 } 1363 1364 /* Extract the source address from a chunk. */ 1365 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1366 { 1367 /* If we have a known transport, use that. */ 1368 if (chunk->transport) { 1369 return &chunk->transport->ipaddr; 1370 } else { 1371 /* Otherwise, extract it from the IP header. */ 1372 return &chunk->source; 1373 } 1374 } 1375 1376 /* Create a new chunk, setting the type and flags headers from the 1377 * arguments, reserving enough space for a 'paylen' byte payload. 1378 */ 1379 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 1380 __u8 type, __u8 flags, int paylen, 1381 gfp_t gfp) 1382 { 1383 struct sctp_chunkhdr *chunk_hdr; 1384 struct sctp_chunk *retval; 1385 struct sk_buff *skb; 1386 struct sock *sk; 1387 int chunklen; 1388 1389 chunklen = SCTP_PAD4(sizeof(*chunk_hdr) + paylen); 1390 if (chunklen > SCTP_MAX_CHUNK_LEN) 1391 goto nodata; 1392 1393 /* No need to allocate LL here, as this is only a chunk. */ 1394 skb = alloc_skb(chunklen, gfp); 1395 if (!skb) 1396 goto nodata; 1397 1398 /* Make room for the chunk header. */ 1399 chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr)); 1400 chunk_hdr->type = type; 1401 chunk_hdr->flags = flags; 1402 chunk_hdr->length = htons(sizeof(*chunk_hdr)); 1403 1404 sk = asoc ? asoc->base.sk : NULL; 1405 retval = sctp_chunkify(skb, asoc, sk, gfp); 1406 if (!retval) { 1407 kfree_skb(skb); 1408 goto nodata; 1409 } 1410 1411 retval->chunk_hdr = chunk_hdr; 1412 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr); 1413 1414 /* Determine if the chunk needs to be authenticated */ 1415 if (sctp_auth_send_cid(type, asoc)) 1416 retval->auth = 1; 1417 1418 return retval; 1419 nodata: 1420 return NULL; 1421 } 1422 1423 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 1424 __u8 flags, int paylen, gfp_t gfp) 1425 { 1426 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp); 1427 } 1428 1429 struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc, 1430 __u8 flags, int paylen, gfp_t gfp) 1431 { 1432 return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp); 1433 } 1434 1435 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 1436 __u8 type, __u8 flags, int paylen, 1437 gfp_t gfp) 1438 { 1439 struct sctp_chunk *chunk; 1440 1441 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp); 1442 if (chunk) 1443 sctp_control_set_owner_w(chunk); 1444 1445 return chunk; 1446 } 1447 1448 /* Release the memory occupied by a chunk. */ 1449 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1450 { 1451 BUG_ON(!list_empty(&chunk->list)); 1452 list_del_init(&chunk->transmitted_list); 1453 1454 consume_skb(chunk->skb); 1455 consume_skb(chunk->auth_chunk); 1456 1457 SCTP_DBG_OBJCNT_DEC(chunk); 1458 kmem_cache_free(sctp_chunk_cachep, chunk); 1459 } 1460 1461 /* Possibly, free the chunk. */ 1462 void sctp_chunk_free(struct sctp_chunk *chunk) 1463 { 1464 /* Release our reference on the message tracker. */ 1465 if (chunk->msg) 1466 sctp_datamsg_put(chunk->msg); 1467 1468 sctp_chunk_put(chunk); 1469 } 1470 1471 /* Grab a reference to the chunk. */ 1472 void sctp_chunk_hold(struct sctp_chunk *ch) 1473 { 1474 refcount_inc(&ch->refcnt); 1475 } 1476 1477 /* Release a reference to the chunk. */ 1478 void sctp_chunk_put(struct sctp_chunk *ch) 1479 { 1480 if (refcount_dec_and_test(&ch->refcnt)) 1481 sctp_chunk_destroy(ch); 1482 } 1483 1484 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1485 * enough. 1486 */ 1487 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1488 { 1489 int chunklen = ntohs(chunk->chunk_hdr->length); 1490 int padlen = SCTP_PAD4(chunklen) - chunklen; 1491 void *target; 1492 1493 skb_put_zero(chunk->skb, padlen); 1494 target = skb_put_data(chunk->skb, data, len); 1495 1496 /* Adjust the chunk length field. */ 1497 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1498 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1499 1500 return target; 1501 } 1502 1503 /* Append bytes from user space to the end of a chunk. Will panic if 1504 * chunk is not big enough. 1505 * Returns a kernel err value. 1506 */ 1507 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len, 1508 struct iov_iter *from) 1509 { 1510 void *target; 1511 1512 /* Make room in chunk for data. */ 1513 target = skb_put(chunk->skb, len); 1514 1515 /* Copy data (whole iovec) into chunk */ 1516 if (!copy_from_iter_full(target, len, from)) 1517 return -EFAULT; 1518 1519 /* Adjust the chunk length field. */ 1520 chunk->chunk_hdr->length = 1521 htons(ntohs(chunk->chunk_hdr->length) + len); 1522 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1523 1524 return 0; 1525 } 1526 1527 /* Helper function to assign a TSN if needed. This assumes that both 1528 * the data_hdr and association have already been assigned. 1529 */ 1530 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1531 { 1532 struct sctp_stream *stream; 1533 struct sctp_chunk *lchunk; 1534 struct sctp_datamsg *msg; 1535 __u16 ssn, sid; 1536 1537 if (chunk->has_ssn) 1538 return; 1539 1540 /* All fragments will be on the same stream */ 1541 sid = ntohs(chunk->subh.data_hdr->stream); 1542 stream = &chunk->asoc->stream; 1543 1544 /* Now assign the sequence number to the entire message. 1545 * All fragments must have the same stream sequence number. 1546 */ 1547 msg = chunk->msg; 1548 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1549 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1550 ssn = 0; 1551 } else { 1552 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1553 ssn = sctp_ssn_next(stream, out, sid); 1554 else 1555 ssn = sctp_ssn_peek(stream, out, sid); 1556 } 1557 1558 lchunk->subh.data_hdr->ssn = htons(ssn); 1559 lchunk->has_ssn = 1; 1560 } 1561 } 1562 1563 /* Helper function to assign a TSN if needed. This assumes that both 1564 * the data_hdr and association have already been assigned. 1565 */ 1566 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1567 { 1568 if (!chunk->has_tsn) { 1569 /* This is the last possible instant to 1570 * assign a TSN. 1571 */ 1572 chunk->subh.data_hdr->tsn = 1573 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1574 chunk->has_tsn = 1; 1575 } 1576 } 1577 1578 /* Create a CLOSED association to use with an incoming packet. */ 1579 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1580 struct sctp_chunk *chunk, 1581 gfp_t gfp) 1582 { 1583 struct sctp_association *asoc; 1584 enum sctp_scope scope; 1585 struct sk_buff *skb; 1586 1587 /* Create the bare association. */ 1588 scope = sctp_scope(sctp_source(chunk)); 1589 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1590 if (!asoc) 1591 goto nodata; 1592 asoc->temp = 1; 1593 skb = chunk->skb; 1594 /* Create an entry for the source address of the packet. */ 1595 SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1); 1596 1597 nodata: 1598 return asoc; 1599 } 1600 1601 /* Build a cookie representing asoc. 1602 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1603 */ 1604 static struct sctp_cookie_param *sctp_pack_cookie( 1605 const struct sctp_endpoint *ep, 1606 const struct sctp_association *asoc, 1607 const struct sctp_chunk *init_chunk, 1608 int *cookie_len, const __u8 *raw_addrs, 1609 int addrs_len) 1610 { 1611 struct sctp_signed_cookie *cookie; 1612 struct sctp_cookie_param *retval; 1613 int headersize, bodysize; 1614 1615 /* Header size is static data prior to the actual cookie, including 1616 * any padding. 1617 */ 1618 headersize = sizeof(struct sctp_paramhdr) + 1619 (sizeof(struct sctp_signed_cookie) - 1620 sizeof(struct sctp_cookie)); 1621 bodysize = sizeof(struct sctp_cookie) 1622 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1623 1624 /* Pad out the cookie to a multiple to make the signature 1625 * functions simpler to write. 1626 */ 1627 if (bodysize % SCTP_COOKIE_MULTIPLE) 1628 bodysize += SCTP_COOKIE_MULTIPLE 1629 - (bodysize % SCTP_COOKIE_MULTIPLE); 1630 *cookie_len = headersize + bodysize; 1631 1632 /* Clear this memory since we are sending this data structure 1633 * out on the network. 1634 */ 1635 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1636 if (!retval) 1637 goto nodata; 1638 1639 cookie = (struct sctp_signed_cookie *) retval->body; 1640 1641 /* Set up the parameter header. */ 1642 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1643 retval->p.length = htons(*cookie_len); 1644 1645 /* Copy the cookie part of the association itself. */ 1646 cookie->c = asoc->c; 1647 /* Save the raw address list length in the cookie. */ 1648 cookie->c.raw_addr_list_len = addrs_len; 1649 1650 /* Remember PR-SCTP capability. */ 1651 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1652 1653 /* Save adaptation indication in the cookie. */ 1654 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1655 1656 /* Set an expiration time for the cookie. */ 1657 cookie->c.expiration = ktime_add(asoc->cookie_life, 1658 ktime_get_real()); 1659 1660 /* Copy the peer's init packet. */ 1661 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr, 1662 ntohs(init_chunk->chunk_hdr->length)); 1663 1664 /* Copy the raw local address list of the association. */ 1665 memcpy((__u8 *)&cookie->c.peer_init[0] + 1666 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1667 1668 if (sctp_sk(ep->base.sk)->hmac) { 1669 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac); 1670 int err; 1671 1672 /* Sign the message. */ 1673 desc->tfm = sctp_sk(ep->base.sk)->hmac; 1674 1675 err = crypto_shash_setkey(desc->tfm, ep->secret_key, 1676 sizeof(ep->secret_key)) ?: 1677 crypto_shash_digest(desc, (u8 *)&cookie->c, bodysize, 1678 cookie->signature); 1679 shash_desc_zero(desc); 1680 if (err) 1681 goto free_cookie; 1682 } 1683 1684 return retval; 1685 1686 free_cookie: 1687 kfree(retval); 1688 nodata: 1689 *cookie_len = 0; 1690 return NULL; 1691 } 1692 1693 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1694 struct sctp_association *sctp_unpack_cookie( 1695 const struct sctp_endpoint *ep, 1696 const struct sctp_association *asoc, 1697 struct sctp_chunk *chunk, gfp_t gfp, 1698 int *error, struct sctp_chunk **errp) 1699 { 1700 struct sctp_association *retval = NULL; 1701 int headersize, bodysize, fixed_size; 1702 struct sctp_signed_cookie *cookie; 1703 struct sk_buff *skb = chunk->skb; 1704 struct sctp_cookie *bear_cookie; 1705 __u8 *digest = ep->digest; 1706 enum sctp_scope scope; 1707 unsigned int len; 1708 ktime_t kt; 1709 1710 /* Header size is static data prior to the actual cookie, including 1711 * any padding. 1712 */ 1713 headersize = sizeof(struct sctp_chunkhdr) + 1714 (sizeof(struct sctp_signed_cookie) - 1715 sizeof(struct sctp_cookie)); 1716 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1717 fixed_size = headersize + sizeof(struct sctp_cookie); 1718 1719 /* Verify that the chunk looks like it even has a cookie. 1720 * There must be enough room for our cookie and our peer's 1721 * INIT chunk. 1722 */ 1723 len = ntohs(chunk->chunk_hdr->length); 1724 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1725 goto malformed; 1726 1727 /* Verify that the cookie has been padded out. */ 1728 if (bodysize % SCTP_COOKIE_MULTIPLE) 1729 goto malformed; 1730 1731 /* Process the cookie. */ 1732 cookie = chunk->subh.cookie_hdr; 1733 bear_cookie = &cookie->c; 1734 1735 if (!sctp_sk(ep->base.sk)->hmac) 1736 goto no_hmac; 1737 1738 /* Check the signature. */ 1739 { 1740 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac); 1741 int err; 1742 1743 desc->tfm = sctp_sk(ep->base.sk)->hmac; 1744 1745 err = crypto_shash_setkey(desc->tfm, ep->secret_key, 1746 sizeof(ep->secret_key)) ?: 1747 crypto_shash_digest(desc, (u8 *)bear_cookie, bodysize, 1748 digest); 1749 shash_desc_zero(desc); 1750 1751 if (err) { 1752 *error = -SCTP_IERROR_NOMEM; 1753 goto fail; 1754 } 1755 } 1756 1757 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1758 *error = -SCTP_IERROR_BAD_SIG; 1759 goto fail; 1760 } 1761 1762 no_hmac: 1763 /* IG Section 2.35.2: 1764 * 3) Compare the port numbers and the verification tag contained 1765 * within the COOKIE ECHO chunk to the actual port numbers and the 1766 * verification tag within the SCTP common header of the received 1767 * packet. If these values do not match the packet MUST be silently 1768 * discarded, 1769 */ 1770 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1771 *error = -SCTP_IERROR_BAD_TAG; 1772 goto fail; 1773 } 1774 1775 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1776 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1777 *error = -SCTP_IERROR_BAD_PORTS; 1778 goto fail; 1779 } 1780 1781 /* Check to see if the cookie is stale. If there is already 1782 * an association, there is no need to check cookie's expiration 1783 * for init collision case of lost COOKIE ACK. 1784 * If skb has been timestamped, then use the stamp, otherwise 1785 * use current time. This introduces a small possibility that 1786 * that a cookie may be considered expired, but his would only slow 1787 * down the new association establishment instead of every packet. 1788 */ 1789 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1790 kt = skb_get_ktime(skb); 1791 else 1792 kt = ktime_get_real(); 1793 1794 if (!asoc && ktime_before(bear_cookie->expiration, kt)) { 1795 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); 1796 __be32 n = htonl(usecs); 1797 1798 /* 1799 * Section 3.3.10.3 Stale Cookie Error (3) 1800 * 1801 * Cause of error 1802 * --------------- 1803 * Stale Cookie Error: Indicates the receipt of a valid State 1804 * Cookie that has expired. 1805 */ 1806 *errp = sctp_make_op_error(asoc, chunk, 1807 SCTP_ERROR_STALE_COOKIE, &n, 1808 sizeof(n), 0); 1809 if (*errp) 1810 *error = -SCTP_IERROR_STALE_COOKIE; 1811 else 1812 *error = -SCTP_IERROR_NOMEM; 1813 1814 goto fail; 1815 } 1816 1817 /* Make a new base association. */ 1818 scope = sctp_scope(sctp_source(chunk)); 1819 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1820 if (!retval) { 1821 *error = -SCTP_IERROR_NOMEM; 1822 goto fail; 1823 } 1824 1825 /* Set up our peer's port number. */ 1826 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1827 1828 /* Populate the association from the cookie. */ 1829 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1830 1831 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1832 GFP_ATOMIC) < 0) { 1833 *error = -SCTP_IERROR_NOMEM; 1834 goto fail; 1835 } 1836 1837 /* Also, add the destination address. */ 1838 if (list_empty(&retval->base.bind_addr.address_list)) { 1839 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1840 sizeof(chunk->dest), SCTP_ADDR_SRC, 1841 GFP_ATOMIC); 1842 } 1843 1844 retval->next_tsn = retval->c.initial_tsn; 1845 retval->ctsn_ack_point = retval->next_tsn - 1; 1846 retval->addip_serial = retval->c.initial_tsn; 1847 retval->strreset_outseq = retval->c.initial_tsn; 1848 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1849 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1850 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1851 1852 /* The INIT stuff will be done by the side effects. */ 1853 return retval; 1854 1855 fail: 1856 if (retval) 1857 sctp_association_free(retval); 1858 1859 return NULL; 1860 1861 malformed: 1862 /* Yikes! The packet is either corrupt or deliberately 1863 * malformed. 1864 */ 1865 *error = -SCTP_IERROR_MALFORMED; 1866 goto fail; 1867 } 1868 1869 /******************************************************************** 1870 * 3rd Level Abstractions 1871 ********************************************************************/ 1872 1873 struct __sctp_missing { 1874 __be32 num_missing; 1875 __be16 type; 1876 } __packed; 1877 1878 /* 1879 * Report a missing mandatory parameter. 1880 */ 1881 static int sctp_process_missing_param(const struct sctp_association *asoc, 1882 enum sctp_param paramtype, 1883 struct sctp_chunk *chunk, 1884 struct sctp_chunk **errp) 1885 { 1886 struct __sctp_missing report; 1887 __u16 len; 1888 1889 len = SCTP_PAD4(sizeof(report)); 1890 1891 /* Make an ERROR chunk, preparing enough room for 1892 * returning multiple unknown parameters. 1893 */ 1894 if (!*errp) 1895 *errp = sctp_make_op_error_space(asoc, chunk, len); 1896 1897 if (*errp) { 1898 report.num_missing = htonl(1); 1899 report.type = paramtype; 1900 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1901 sizeof(report)); 1902 sctp_addto_chunk(*errp, sizeof(report), &report); 1903 } 1904 1905 /* Stop processing this chunk. */ 1906 return 0; 1907 } 1908 1909 /* Report an Invalid Mandatory Parameter. */ 1910 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1911 struct sctp_chunk *chunk, 1912 struct sctp_chunk **errp) 1913 { 1914 /* Invalid Mandatory Parameter Error has no payload. */ 1915 1916 if (!*errp) 1917 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1918 1919 if (*errp) 1920 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1921 1922 /* Stop processing this chunk. */ 1923 return 0; 1924 } 1925 1926 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1927 struct sctp_paramhdr *param, 1928 const struct sctp_chunk *chunk, 1929 struct sctp_chunk **errp) 1930 { 1931 /* This is a fatal error. Any accumulated non-fatal errors are 1932 * not reported. 1933 */ 1934 if (*errp) 1935 sctp_chunk_free(*errp); 1936 1937 /* Create an error chunk and fill it in with our payload. */ 1938 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1939 1940 return 0; 1941 } 1942 1943 1944 /* Do not attempt to handle the HOST_NAME parm. However, do 1945 * send back an indicator to the peer. 1946 */ 1947 static int sctp_process_hn_param(const struct sctp_association *asoc, 1948 union sctp_params param, 1949 struct sctp_chunk *chunk, 1950 struct sctp_chunk **errp) 1951 { 1952 __u16 len = ntohs(param.p->length); 1953 1954 /* Processing of the HOST_NAME parameter will generate an 1955 * ABORT. If we've accumulated any non-fatal errors, they 1956 * would be unrecognized parameters and we should not include 1957 * them in the ABORT. 1958 */ 1959 if (*errp) 1960 sctp_chunk_free(*errp); 1961 1962 *errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_DNS_FAILED, 1963 param.v, len, 0); 1964 1965 /* Stop processing this chunk. */ 1966 return 0; 1967 } 1968 1969 static int sctp_verify_ext_param(struct net *net, 1970 const struct sctp_endpoint *ep, 1971 union sctp_params param) 1972 { 1973 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 1974 int have_asconf = 0; 1975 int have_auth = 0; 1976 int i; 1977 1978 for (i = 0; i < num_ext; i++) { 1979 switch (param.ext->chunks[i]) { 1980 case SCTP_CID_AUTH: 1981 have_auth = 1; 1982 break; 1983 case SCTP_CID_ASCONF: 1984 case SCTP_CID_ASCONF_ACK: 1985 have_asconf = 1; 1986 break; 1987 } 1988 } 1989 1990 /* ADD-IP Security: The draft requires us to ABORT or ignore the 1991 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 1992 * only if ADD-IP is turned on and we are not backward-compatible 1993 * mode. 1994 */ 1995 if (net->sctp.addip_noauth) 1996 return 1; 1997 1998 if (ep->asconf_enable && !have_auth && have_asconf) 1999 return 0; 2000 2001 return 1; 2002 } 2003 2004 static void sctp_process_ext_param(struct sctp_association *asoc, 2005 union sctp_params param) 2006 { 2007 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2008 int i; 2009 2010 for (i = 0; i < num_ext; i++) { 2011 switch (param.ext->chunks[i]) { 2012 case SCTP_CID_RECONF: 2013 if (asoc->ep->reconf_enable) 2014 asoc->peer.reconf_capable = 1; 2015 break; 2016 case SCTP_CID_FWD_TSN: 2017 if (asoc->ep->prsctp_enable) 2018 asoc->peer.prsctp_capable = 1; 2019 break; 2020 case SCTP_CID_AUTH: 2021 /* if the peer reports AUTH, assume that he 2022 * supports AUTH. 2023 */ 2024 if (asoc->ep->auth_enable) 2025 asoc->peer.auth_capable = 1; 2026 break; 2027 case SCTP_CID_ASCONF: 2028 case SCTP_CID_ASCONF_ACK: 2029 if (asoc->ep->asconf_enable) 2030 asoc->peer.asconf_capable = 1; 2031 break; 2032 case SCTP_CID_I_DATA: 2033 if (asoc->ep->intl_enable) 2034 asoc->peer.intl_capable = 1; 2035 break; 2036 default: 2037 break; 2038 } 2039 } 2040 } 2041 2042 /* RFC 3.2.1 & the Implementers Guide 2.2. 2043 * 2044 * The Parameter Types are encoded such that the 2045 * highest-order two bits specify the action that must be 2046 * taken if the processing endpoint does not recognize the 2047 * Parameter Type. 2048 * 2049 * 00 - Stop processing this parameter; do not process any further 2050 * parameters within this chunk 2051 * 2052 * 01 - Stop processing this parameter, do not process any further 2053 * parameters within this chunk, and report the unrecognized 2054 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2055 * 2056 * 10 - Skip this parameter and continue processing. 2057 * 2058 * 11 - Skip this parameter and continue processing but 2059 * report the unrecognized parameter in an 2060 * 'Unrecognized Parameter' ERROR chunk. 2061 * 2062 * Return value: 2063 * SCTP_IERROR_NO_ERROR - continue with the chunk 2064 * SCTP_IERROR_ERROR - stop and report an error. 2065 * SCTP_IERROR_NOMEME - out of memory. 2066 */ 2067 static enum sctp_ierror sctp_process_unk_param( 2068 const struct sctp_association *asoc, 2069 union sctp_params param, 2070 struct sctp_chunk *chunk, 2071 struct sctp_chunk **errp) 2072 { 2073 int retval = SCTP_IERROR_NO_ERROR; 2074 2075 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2076 case SCTP_PARAM_ACTION_DISCARD: 2077 retval = SCTP_IERROR_ERROR; 2078 break; 2079 case SCTP_PARAM_ACTION_SKIP: 2080 break; 2081 case SCTP_PARAM_ACTION_DISCARD_ERR: 2082 retval = SCTP_IERROR_ERROR; 2083 /* Fall through */ 2084 case SCTP_PARAM_ACTION_SKIP_ERR: 2085 /* Make an ERROR chunk, preparing enough room for 2086 * returning multiple unknown parameters. 2087 */ 2088 if (!*errp) { 2089 *errp = sctp_make_op_error_limited(asoc, chunk); 2090 if (!*errp) { 2091 /* If there is no memory for generating the 2092 * ERROR report as specified, an ABORT will be 2093 * triggered to the peer and the association 2094 * won't be established. 2095 */ 2096 retval = SCTP_IERROR_NOMEM; 2097 break; 2098 } 2099 } 2100 2101 if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2102 ntohs(param.p->length))) 2103 sctp_addto_chunk(*errp, ntohs(param.p->length), 2104 param.v); 2105 break; 2106 default: 2107 break; 2108 } 2109 2110 return retval; 2111 } 2112 2113 /* Verify variable length parameters 2114 * Return values: 2115 * SCTP_IERROR_ABORT - trigger an ABORT 2116 * SCTP_IERROR_NOMEM - out of memory (abort) 2117 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2118 * SCTP_IERROR_NO_ERROR - continue with the chunk 2119 */ 2120 static enum sctp_ierror sctp_verify_param(struct net *net, 2121 const struct sctp_endpoint *ep, 2122 const struct sctp_association *asoc, 2123 union sctp_params param, 2124 enum sctp_cid cid, 2125 struct sctp_chunk *chunk, 2126 struct sctp_chunk **err_chunk) 2127 { 2128 struct sctp_hmac_algo_param *hmacs; 2129 int retval = SCTP_IERROR_NO_ERROR; 2130 __u16 n_elt, id = 0; 2131 int i; 2132 2133 /* FIXME - This routine is not looking at each parameter per the 2134 * chunk type, i.e., unrecognized parameters should be further 2135 * identified based on the chunk id. 2136 */ 2137 2138 switch (param.p->type) { 2139 case SCTP_PARAM_IPV4_ADDRESS: 2140 case SCTP_PARAM_IPV6_ADDRESS: 2141 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2142 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2143 case SCTP_PARAM_STATE_COOKIE: 2144 case SCTP_PARAM_HEARTBEAT_INFO: 2145 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2146 case SCTP_PARAM_ECN_CAPABLE: 2147 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2148 break; 2149 2150 case SCTP_PARAM_SUPPORTED_EXT: 2151 if (!sctp_verify_ext_param(net, ep, param)) 2152 return SCTP_IERROR_ABORT; 2153 break; 2154 2155 case SCTP_PARAM_SET_PRIMARY: 2156 if (ep->asconf_enable) 2157 break; 2158 goto fallthrough; 2159 2160 case SCTP_PARAM_HOST_NAME_ADDRESS: 2161 /* Tell the peer, we won't support this param. */ 2162 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2163 retval = SCTP_IERROR_ABORT; 2164 break; 2165 2166 case SCTP_PARAM_FWD_TSN_SUPPORT: 2167 if (ep->prsctp_enable) 2168 break; 2169 goto fallthrough; 2170 2171 case SCTP_PARAM_RANDOM: 2172 if (!ep->auth_enable) 2173 goto fallthrough; 2174 2175 /* SCTP-AUTH: Secion 6.1 2176 * If the random number is not 32 byte long the association 2177 * MUST be aborted. The ABORT chunk SHOULD contain the error 2178 * cause 'Protocol Violation'. 2179 */ 2180 if (SCTP_AUTH_RANDOM_LENGTH != ntohs(param.p->length) - 2181 sizeof(struct sctp_paramhdr)) { 2182 sctp_process_inv_paramlength(asoc, param.p, 2183 chunk, err_chunk); 2184 retval = SCTP_IERROR_ABORT; 2185 } 2186 break; 2187 2188 case SCTP_PARAM_CHUNKS: 2189 if (!ep->auth_enable) 2190 goto fallthrough; 2191 2192 /* SCTP-AUTH: Section 3.2 2193 * The CHUNKS parameter MUST be included once in the INIT or 2194 * INIT-ACK chunk if the sender wants to receive authenticated 2195 * chunks. Its maximum length is 260 bytes. 2196 */ 2197 if (260 < ntohs(param.p->length)) { 2198 sctp_process_inv_paramlength(asoc, param.p, 2199 chunk, err_chunk); 2200 retval = SCTP_IERROR_ABORT; 2201 } 2202 break; 2203 2204 case SCTP_PARAM_HMAC_ALGO: 2205 if (!ep->auth_enable) 2206 goto fallthrough; 2207 2208 hmacs = (struct sctp_hmac_algo_param *)param.p; 2209 n_elt = (ntohs(param.p->length) - 2210 sizeof(struct sctp_paramhdr)) >> 1; 2211 2212 /* SCTP-AUTH: Section 6.1 2213 * The HMAC algorithm based on SHA-1 MUST be supported and 2214 * included in the HMAC-ALGO parameter. 2215 */ 2216 for (i = 0; i < n_elt; i++) { 2217 id = ntohs(hmacs->hmac_ids[i]); 2218 2219 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2220 break; 2221 } 2222 2223 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2224 sctp_process_inv_paramlength(asoc, param.p, chunk, 2225 err_chunk); 2226 retval = SCTP_IERROR_ABORT; 2227 } 2228 break; 2229 fallthrough: 2230 default: 2231 pr_debug("%s: unrecognized param:%d for chunk:%d\n", 2232 __func__, ntohs(param.p->type), cid); 2233 2234 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2235 break; 2236 } 2237 return retval; 2238 } 2239 2240 /* Verify the INIT packet before we process it. */ 2241 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 2242 const struct sctp_association *asoc, enum sctp_cid cid, 2243 struct sctp_init_chunk *peer_init, 2244 struct sctp_chunk *chunk, struct sctp_chunk **errp) 2245 { 2246 union sctp_params param; 2247 bool has_cookie = false; 2248 int result; 2249 2250 /* Check for missing mandatory parameters. Note: Initial TSN is 2251 * also mandatory, but is not checked here since the valid range 2252 * is 0..2**32-1. RFC4960, section 3.3.3. 2253 */ 2254 if (peer_init->init_hdr.num_outbound_streams == 0 || 2255 peer_init->init_hdr.num_inbound_streams == 0 || 2256 peer_init->init_hdr.init_tag == 0 || 2257 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) 2258 return sctp_process_inv_mandatory(asoc, chunk, errp); 2259 2260 sctp_walk_params(param, peer_init, init_hdr.params) { 2261 if (param.p->type == SCTP_PARAM_STATE_COOKIE) 2262 has_cookie = true; 2263 } 2264 2265 /* There is a possibility that a parameter length was bad and 2266 * in that case we would have stoped walking the parameters. 2267 * The current param.p would point at the bad one. 2268 * Current consensus on the mailing list is to generate a PROTOCOL 2269 * VIOLATION error. We build the ERROR chunk here and let the normal 2270 * error handling code build and send the packet. 2271 */ 2272 if (param.v != (void *)chunk->chunk_end) 2273 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2274 2275 /* The only missing mandatory param possible today is 2276 * the state cookie for an INIT-ACK chunk. 2277 */ 2278 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2279 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2280 chunk, errp); 2281 2282 /* Verify all the variable length parameters */ 2283 sctp_walk_params(param, peer_init, init_hdr.params) { 2284 result = sctp_verify_param(net, ep, asoc, param, cid, 2285 chunk, errp); 2286 switch (result) { 2287 case SCTP_IERROR_ABORT: 2288 case SCTP_IERROR_NOMEM: 2289 return 0; 2290 case SCTP_IERROR_ERROR: 2291 return 1; 2292 case SCTP_IERROR_NO_ERROR: 2293 default: 2294 break; 2295 } 2296 2297 } /* for (loop through all parameters) */ 2298 2299 return 1; 2300 } 2301 2302 /* Unpack the parameters in an INIT packet into an association. 2303 * Returns 0 on failure, else success. 2304 * FIXME: This is an association method. 2305 */ 2306 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2307 const union sctp_addr *peer_addr, 2308 struct sctp_init_chunk *peer_init, gfp_t gfp) 2309 { 2310 struct net *net = sock_net(asoc->base.sk); 2311 struct sctp_transport *transport; 2312 struct list_head *pos, *temp; 2313 union sctp_params param; 2314 union sctp_addr addr; 2315 struct sctp_af *af; 2316 int src_match = 0; 2317 2318 /* We must include the address that the INIT packet came from. 2319 * This is the only address that matters for an INIT packet. 2320 * When processing a COOKIE ECHO, we retrieve the from address 2321 * of the INIT from the cookie. 2322 */ 2323 2324 /* This implementation defaults to making the first transport 2325 * added as the primary transport. The source address seems to 2326 * be a a better choice than any of the embedded addresses. 2327 */ 2328 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2329 goto nomem; 2330 2331 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2332 src_match = 1; 2333 2334 /* Process the initialization parameters. */ 2335 sctp_walk_params(param, peer_init, init_hdr.params) { 2336 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2337 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2338 af = sctp_get_af_specific(param_type2af(param.p->type)); 2339 af->from_addr_param(&addr, param.addr, 2340 chunk->sctp_hdr->source, 0); 2341 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2342 src_match = 1; 2343 } 2344 2345 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2346 goto clean_up; 2347 } 2348 2349 /* source address of chunk may not match any valid address */ 2350 if (!src_match) 2351 goto clean_up; 2352 2353 /* AUTH: After processing the parameters, make sure that we 2354 * have all the required info to potentially do authentications. 2355 */ 2356 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2357 !asoc->peer.peer_hmacs)) 2358 asoc->peer.auth_capable = 0; 2359 2360 /* In a non-backward compatible mode, if the peer claims 2361 * support for ADD-IP but not AUTH, the ADD-IP spec states 2362 * that we MUST ABORT the association. Section 6. The section 2363 * also give us an option to silently ignore the packet, which 2364 * is what we'll do here. 2365 */ 2366 if (!net->sctp.addip_noauth && 2367 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2368 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2369 SCTP_PARAM_DEL_IP | 2370 SCTP_PARAM_SET_PRIMARY); 2371 asoc->peer.asconf_capable = 0; 2372 goto clean_up; 2373 } 2374 2375 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2376 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2377 transport = list_entry(pos, struct sctp_transport, transports); 2378 if (transport->state == SCTP_UNKNOWN) { 2379 sctp_assoc_rm_peer(asoc, transport); 2380 } 2381 } 2382 2383 /* The fixed INIT headers are always in network byte 2384 * order. 2385 */ 2386 asoc->peer.i.init_tag = 2387 ntohl(peer_init->init_hdr.init_tag); 2388 asoc->peer.i.a_rwnd = 2389 ntohl(peer_init->init_hdr.a_rwnd); 2390 asoc->peer.i.num_outbound_streams = 2391 ntohs(peer_init->init_hdr.num_outbound_streams); 2392 asoc->peer.i.num_inbound_streams = 2393 ntohs(peer_init->init_hdr.num_inbound_streams); 2394 asoc->peer.i.initial_tsn = 2395 ntohl(peer_init->init_hdr.initial_tsn); 2396 2397 asoc->strreset_inseq = asoc->peer.i.initial_tsn; 2398 2399 /* Apply the upper bounds for output streams based on peer's 2400 * number of inbound streams. 2401 */ 2402 if (asoc->c.sinit_num_ostreams > 2403 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2404 asoc->c.sinit_num_ostreams = 2405 ntohs(peer_init->init_hdr.num_inbound_streams); 2406 } 2407 2408 if (asoc->c.sinit_max_instreams > 2409 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2410 asoc->c.sinit_max_instreams = 2411 ntohs(peer_init->init_hdr.num_outbound_streams); 2412 } 2413 2414 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2415 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2416 2417 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2418 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2419 2420 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2421 * high (for example, implementations MAY use the size of the receiver 2422 * advertised window). 2423 */ 2424 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2425 transports) { 2426 transport->ssthresh = asoc->peer.i.a_rwnd; 2427 } 2428 2429 /* Set up the TSN tracking pieces. */ 2430 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2431 asoc->peer.i.initial_tsn, gfp)) 2432 goto clean_up; 2433 2434 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2435 * 2436 * The stream sequence number in all the streams shall start 2437 * from 0 when the association is established. Also, when the 2438 * stream sequence number reaches the value 65535 the next 2439 * stream sequence number shall be set to 0. 2440 */ 2441 2442 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams, 2443 asoc->c.sinit_max_instreams, gfp)) 2444 goto clean_up; 2445 2446 /* Update frag_point when stream_interleave may get changed. */ 2447 sctp_assoc_update_frag_point(asoc); 2448 2449 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp)) 2450 goto clean_up; 2451 2452 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2453 * 2454 * When an endpoint has an ASCONF signaled change to be sent to the 2455 * remote endpoint it should do the following: 2456 * ... 2457 * A2) A serial number should be assigned to the Chunk. The serial 2458 * number should be a monotonically increasing number. All serial 2459 * numbers are defined to be initialized at the start of the 2460 * association to the same value as the Initial TSN. 2461 */ 2462 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2463 return 1; 2464 2465 clean_up: 2466 /* Release the transport structures. */ 2467 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2468 transport = list_entry(pos, struct sctp_transport, transports); 2469 if (transport->state != SCTP_ACTIVE) 2470 sctp_assoc_rm_peer(asoc, transport); 2471 } 2472 2473 nomem: 2474 return 0; 2475 } 2476 2477 2478 /* Update asoc with the option described in param. 2479 * 2480 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2481 * 2482 * asoc is the association to update. 2483 * param is the variable length parameter to use for update. 2484 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2485 * If the current packet is an INIT we want to minimize the amount of 2486 * work we do. In particular, we should not build transport 2487 * structures for the addresses. 2488 */ 2489 static int sctp_process_param(struct sctp_association *asoc, 2490 union sctp_params param, 2491 const union sctp_addr *peer_addr, 2492 gfp_t gfp) 2493 { 2494 struct net *net = sock_net(asoc->base.sk); 2495 struct sctp_endpoint *ep = asoc->ep; 2496 union sctp_addr_param *addr_param; 2497 struct sctp_transport *t; 2498 enum sctp_scope scope; 2499 union sctp_addr addr; 2500 struct sctp_af *af; 2501 int retval = 1, i; 2502 u32 stale; 2503 __u16 sat; 2504 2505 /* We maintain all INIT parameters in network byte order all the 2506 * time. This allows us to not worry about whether the parameters 2507 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2508 */ 2509 switch (param.p->type) { 2510 case SCTP_PARAM_IPV6_ADDRESS: 2511 if (PF_INET6 != asoc->base.sk->sk_family) 2512 break; 2513 goto do_addr_param; 2514 2515 case SCTP_PARAM_IPV4_ADDRESS: 2516 /* v4 addresses are not allowed on v6-only socket */ 2517 if (ipv6_only_sock(asoc->base.sk)) 2518 break; 2519 do_addr_param: 2520 af = sctp_get_af_specific(param_type2af(param.p->type)); 2521 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); 2522 scope = sctp_scope(peer_addr); 2523 if (sctp_in_scope(net, &addr, scope)) 2524 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2525 return 0; 2526 break; 2527 2528 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2529 if (!net->sctp.cookie_preserve_enable) 2530 break; 2531 2532 stale = ntohl(param.life->lifespan_increment); 2533 2534 /* Suggested Cookie Life span increment's unit is msec, 2535 * (1/1000sec). 2536 */ 2537 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale); 2538 break; 2539 2540 case SCTP_PARAM_HOST_NAME_ADDRESS: 2541 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__); 2542 break; 2543 2544 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2545 /* Turn off the default values first so we'll know which 2546 * ones are really set by the peer. 2547 */ 2548 asoc->peer.ipv4_address = 0; 2549 asoc->peer.ipv6_address = 0; 2550 2551 /* Assume that peer supports the address family 2552 * by which it sends a packet. 2553 */ 2554 if (peer_addr->sa.sa_family == AF_INET6) 2555 asoc->peer.ipv6_address = 1; 2556 else if (peer_addr->sa.sa_family == AF_INET) 2557 asoc->peer.ipv4_address = 1; 2558 2559 /* Cycle through address types; avoid divide by 0. */ 2560 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2561 if (sat) 2562 sat /= sizeof(__u16); 2563 2564 for (i = 0; i < sat; ++i) { 2565 switch (param.sat->types[i]) { 2566 case SCTP_PARAM_IPV4_ADDRESS: 2567 asoc->peer.ipv4_address = 1; 2568 break; 2569 2570 case SCTP_PARAM_IPV6_ADDRESS: 2571 if (PF_INET6 == asoc->base.sk->sk_family) 2572 asoc->peer.ipv6_address = 1; 2573 break; 2574 2575 case SCTP_PARAM_HOST_NAME_ADDRESS: 2576 asoc->peer.hostname_address = 1; 2577 break; 2578 2579 default: /* Just ignore anything else. */ 2580 break; 2581 } 2582 } 2583 break; 2584 2585 case SCTP_PARAM_STATE_COOKIE: 2586 asoc->peer.cookie_len = 2587 ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2588 kfree(asoc->peer.cookie); 2589 asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp); 2590 if (!asoc->peer.cookie) 2591 retval = 0; 2592 break; 2593 2594 case SCTP_PARAM_HEARTBEAT_INFO: 2595 /* Would be odd to receive, but it causes no problems. */ 2596 break; 2597 2598 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2599 /* Rejected during verify stage. */ 2600 break; 2601 2602 case SCTP_PARAM_ECN_CAPABLE: 2603 if (asoc->ep->ecn_enable) { 2604 asoc->peer.ecn_capable = 1; 2605 break; 2606 } 2607 /* Fall Through */ 2608 goto fall_through; 2609 2610 2611 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2612 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2613 break; 2614 2615 case SCTP_PARAM_SET_PRIMARY: 2616 if (!ep->asconf_enable) 2617 goto fall_through; 2618 2619 addr_param = param.v + sizeof(struct sctp_addip_param); 2620 2621 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 2622 if (af == NULL) 2623 break; 2624 2625 af->from_addr_param(&addr, addr_param, 2626 htons(asoc->peer.port), 0); 2627 2628 /* if the address is invalid, we can't process it. 2629 * XXX: see spec for what to do. 2630 */ 2631 if (!af->addr_valid(&addr, NULL, NULL)) 2632 break; 2633 2634 t = sctp_assoc_lookup_paddr(asoc, &addr); 2635 if (!t) 2636 break; 2637 2638 sctp_assoc_set_primary(asoc, t); 2639 break; 2640 2641 case SCTP_PARAM_SUPPORTED_EXT: 2642 sctp_process_ext_param(asoc, param); 2643 break; 2644 2645 case SCTP_PARAM_FWD_TSN_SUPPORT: 2646 if (asoc->ep->prsctp_enable) { 2647 asoc->peer.prsctp_capable = 1; 2648 break; 2649 } 2650 /* Fall Through */ 2651 goto fall_through; 2652 2653 case SCTP_PARAM_RANDOM: 2654 if (!ep->auth_enable) 2655 goto fall_through; 2656 2657 /* Save peer's random parameter */ 2658 kfree(asoc->peer.peer_random); 2659 asoc->peer.peer_random = kmemdup(param.p, 2660 ntohs(param.p->length), gfp); 2661 if (!asoc->peer.peer_random) { 2662 retval = 0; 2663 break; 2664 } 2665 break; 2666 2667 case SCTP_PARAM_HMAC_ALGO: 2668 if (!ep->auth_enable) 2669 goto fall_through; 2670 2671 /* Save peer's HMAC list */ 2672 kfree(asoc->peer.peer_hmacs); 2673 asoc->peer.peer_hmacs = kmemdup(param.p, 2674 ntohs(param.p->length), gfp); 2675 if (!asoc->peer.peer_hmacs) { 2676 retval = 0; 2677 break; 2678 } 2679 2680 /* Set the default HMAC the peer requested*/ 2681 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2682 break; 2683 2684 case SCTP_PARAM_CHUNKS: 2685 if (!ep->auth_enable) 2686 goto fall_through; 2687 2688 kfree(asoc->peer.peer_chunks); 2689 asoc->peer.peer_chunks = kmemdup(param.p, 2690 ntohs(param.p->length), gfp); 2691 if (!asoc->peer.peer_chunks) 2692 retval = 0; 2693 break; 2694 fall_through: 2695 default: 2696 /* Any unrecognized parameters should have been caught 2697 * and handled by sctp_verify_param() which should be 2698 * called prior to this routine. Simply log the error 2699 * here. 2700 */ 2701 pr_debug("%s: ignoring param:%d for association:%p.\n", 2702 __func__, ntohs(param.p->type), asoc); 2703 break; 2704 } 2705 2706 return retval; 2707 } 2708 2709 /* Select a new verification tag. */ 2710 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2711 { 2712 /* I believe that this random number generator complies with RFC1750. 2713 * A tag of 0 is reserved for special cases (e.g. INIT). 2714 */ 2715 __u32 x; 2716 2717 do { 2718 get_random_bytes(&x, sizeof(__u32)); 2719 } while (x == 0); 2720 2721 return x; 2722 } 2723 2724 /* Select an initial TSN to send during startup. */ 2725 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2726 { 2727 __u32 retval; 2728 2729 get_random_bytes(&retval, sizeof(__u32)); 2730 return retval; 2731 } 2732 2733 /* 2734 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2735 * 0 1 2 3 2736 * 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 2737 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2738 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2739 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2740 * | Serial Number | 2741 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2742 * | Address Parameter | 2743 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2744 * | ASCONF Parameter #1 | 2745 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2746 * \ \ 2747 * / .... / 2748 * \ \ 2749 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2750 * | ASCONF Parameter #N | 2751 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2752 * 2753 * Address Parameter and other parameter will not be wrapped in this function 2754 */ 2755 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2756 union sctp_addr *addr, 2757 int vparam_len) 2758 { 2759 struct sctp_addiphdr asconf; 2760 struct sctp_chunk *retval; 2761 int length = sizeof(asconf) + vparam_len; 2762 union sctp_addr_param addrparam; 2763 int addrlen; 2764 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2765 2766 addrlen = af->to_addr_param(addr, &addrparam); 2767 if (!addrlen) 2768 return NULL; 2769 length += addrlen; 2770 2771 /* Create the chunk. */ 2772 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length, 2773 GFP_ATOMIC); 2774 if (!retval) 2775 return NULL; 2776 2777 asconf.serial = htonl(asoc->addip_serial++); 2778 2779 retval->subh.addip_hdr = 2780 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2781 retval->param_hdr.v = 2782 sctp_addto_chunk(retval, addrlen, &addrparam); 2783 2784 return retval; 2785 } 2786 2787 /* ADDIP 2788 * 3.2.1 Add IP Address 2789 * 0 1 2 3 2790 * 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 2791 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2792 * | Type = 0xC001 | Length = Variable | 2793 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2794 * | ASCONF-Request Correlation ID | 2795 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2796 * | Address Parameter | 2797 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2798 * 2799 * 3.2.2 Delete IP Address 2800 * 0 1 2 3 2801 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2802 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2803 * | Type = 0xC002 | Length = Variable | 2804 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2805 * | ASCONF-Request Correlation ID | 2806 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2807 * | Address Parameter | 2808 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2809 * 2810 */ 2811 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2812 union sctp_addr *laddr, 2813 struct sockaddr *addrs, 2814 int addrcnt, __be16 flags) 2815 { 2816 union sctp_addr_param addr_param; 2817 struct sctp_addip_param param; 2818 int paramlen = sizeof(param); 2819 struct sctp_chunk *retval; 2820 int addr_param_len = 0; 2821 union sctp_addr *addr; 2822 int totallen = 0, i; 2823 int del_pickup = 0; 2824 struct sctp_af *af; 2825 void *addr_buf; 2826 2827 /* Get total length of all the address parameters. */ 2828 addr_buf = addrs; 2829 for (i = 0; i < addrcnt; i++) { 2830 addr = addr_buf; 2831 af = sctp_get_af_specific(addr->v4.sin_family); 2832 addr_param_len = af->to_addr_param(addr, &addr_param); 2833 2834 totallen += paramlen; 2835 totallen += addr_param_len; 2836 2837 addr_buf += af->sockaddr_len; 2838 if (asoc->asconf_addr_del_pending && !del_pickup) { 2839 /* reuse the parameter length from the same scope one */ 2840 totallen += paramlen; 2841 totallen += addr_param_len; 2842 del_pickup = 1; 2843 2844 pr_debug("%s: picked same-scope del_pending addr, " 2845 "totallen for all addresses is %d\n", 2846 __func__, totallen); 2847 } 2848 } 2849 2850 /* Create an asconf chunk with the required length. */ 2851 retval = sctp_make_asconf(asoc, laddr, totallen); 2852 if (!retval) 2853 return NULL; 2854 2855 /* Add the address parameters to the asconf chunk. */ 2856 addr_buf = addrs; 2857 for (i = 0; i < addrcnt; i++) { 2858 addr = addr_buf; 2859 af = sctp_get_af_specific(addr->v4.sin_family); 2860 addr_param_len = af->to_addr_param(addr, &addr_param); 2861 param.param_hdr.type = flags; 2862 param.param_hdr.length = htons(paramlen + addr_param_len); 2863 param.crr_id = htonl(i); 2864 2865 sctp_addto_chunk(retval, paramlen, ¶m); 2866 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2867 2868 addr_buf += af->sockaddr_len; 2869 } 2870 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2871 addr = asoc->asconf_addr_del_pending; 2872 af = sctp_get_af_specific(addr->v4.sin_family); 2873 addr_param_len = af->to_addr_param(addr, &addr_param); 2874 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2875 param.param_hdr.length = htons(paramlen + addr_param_len); 2876 param.crr_id = htonl(i); 2877 2878 sctp_addto_chunk(retval, paramlen, ¶m); 2879 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2880 } 2881 return retval; 2882 } 2883 2884 /* ADDIP 2885 * 3.2.4 Set Primary IP Address 2886 * 0 1 2 3 2887 * 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 2888 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2889 * | Type =0xC004 | Length = Variable | 2890 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2891 * | ASCONF-Request Correlation ID | 2892 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2893 * | Address Parameter | 2894 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2895 * 2896 * Create an ASCONF chunk with Set Primary IP address parameter. 2897 */ 2898 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2899 union sctp_addr *addr) 2900 { 2901 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2902 union sctp_addr_param addrparam; 2903 struct sctp_addip_param param; 2904 struct sctp_chunk *retval; 2905 int len = sizeof(param); 2906 int addrlen; 2907 2908 addrlen = af->to_addr_param(addr, &addrparam); 2909 if (!addrlen) 2910 return NULL; 2911 len += addrlen; 2912 2913 /* Create the chunk and make asconf header. */ 2914 retval = sctp_make_asconf(asoc, addr, len); 2915 if (!retval) 2916 return NULL; 2917 2918 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2919 param.param_hdr.length = htons(len); 2920 param.crr_id = 0; 2921 2922 sctp_addto_chunk(retval, sizeof(param), ¶m); 2923 sctp_addto_chunk(retval, addrlen, &addrparam); 2924 2925 return retval; 2926 } 2927 2928 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2929 * 0 1 2 3 2930 * 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 2931 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2932 * | Type = 0x80 | Chunk Flags | Chunk Length | 2933 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2934 * | Serial Number | 2935 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2936 * | ASCONF Parameter Response#1 | 2937 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2938 * \ \ 2939 * / .... / 2940 * \ \ 2941 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2942 * | ASCONF Parameter Response#N | 2943 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2944 * 2945 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2946 */ 2947 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2948 __u32 serial, int vparam_len) 2949 { 2950 struct sctp_addiphdr asconf; 2951 struct sctp_chunk *retval; 2952 int length = sizeof(asconf) + vparam_len; 2953 2954 /* Create the chunk. */ 2955 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length, 2956 GFP_ATOMIC); 2957 if (!retval) 2958 return NULL; 2959 2960 asconf.serial = htonl(serial); 2961 2962 retval->subh.addip_hdr = 2963 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2964 2965 return retval; 2966 } 2967 2968 /* Add response parameters to an ASCONF_ACK chunk. */ 2969 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2970 __be16 err_code, 2971 struct sctp_addip_param *asconf_param) 2972 { 2973 struct sctp_addip_param ack_param; 2974 struct sctp_errhdr err_param; 2975 int asconf_param_len = 0; 2976 int err_param_len = 0; 2977 __be16 response_type; 2978 2979 if (SCTP_ERROR_NO_ERROR == err_code) { 2980 response_type = SCTP_PARAM_SUCCESS_REPORT; 2981 } else { 2982 response_type = SCTP_PARAM_ERR_CAUSE; 2983 err_param_len = sizeof(err_param); 2984 if (asconf_param) 2985 asconf_param_len = 2986 ntohs(asconf_param->param_hdr.length); 2987 } 2988 2989 /* Add Success Indication or Error Cause Indication parameter. */ 2990 ack_param.param_hdr.type = response_type; 2991 ack_param.param_hdr.length = htons(sizeof(ack_param) + 2992 err_param_len + 2993 asconf_param_len); 2994 ack_param.crr_id = crr_id; 2995 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 2996 2997 if (SCTP_ERROR_NO_ERROR == err_code) 2998 return; 2999 3000 /* Add Error Cause parameter. */ 3001 err_param.cause = err_code; 3002 err_param.length = htons(err_param_len + asconf_param_len); 3003 sctp_addto_chunk(chunk, err_param_len, &err_param); 3004 3005 /* Add the failed TLV copied from ASCONF chunk. */ 3006 if (asconf_param) 3007 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 3008 } 3009 3010 /* Process a asconf parameter. */ 3011 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 3012 struct sctp_chunk *asconf, 3013 struct sctp_addip_param *asconf_param) 3014 { 3015 union sctp_addr_param *addr_param; 3016 struct sctp_transport *peer; 3017 union sctp_addr addr; 3018 struct sctp_af *af; 3019 3020 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3021 3022 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 3023 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 3024 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 3025 return SCTP_ERROR_UNKNOWN_PARAM; 3026 3027 switch (addr_param->p.type) { 3028 case SCTP_PARAM_IPV6_ADDRESS: 3029 if (!asoc->peer.ipv6_address) 3030 return SCTP_ERROR_DNS_FAILED; 3031 break; 3032 case SCTP_PARAM_IPV4_ADDRESS: 3033 if (!asoc->peer.ipv4_address) 3034 return SCTP_ERROR_DNS_FAILED; 3035 break; 3036 default: 3037 return SCTP_ERROR_DNS_FAILED; 3038 } 3039 3040 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3041 if (unlikely(!af)) 3042 return SCTP_ERROR_DNS_FAILED; 3043 3044 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); 3045 3046 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3047 * or multicast address. 3048 * (note: wildcard is permitted and requires special handling so 3049 * make sure we check for that) 3050 */ 3051 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3052 return SCTP_ERROR_DNS_FAILED; 3053 3054 switch (asconf_param->param_hdr.type) { 3055 case SCTP_PARAM_ADD_IP: 3056 /* Section 4.2.1: 3057 * If the address 0.0.0.0 or ::0 is provided, the source 3058 * address of the packet MUST be added. 3059 */ 3060 if (af->is_any(&addr)) 3061 memcpy(&addr, &asconf->source, sizeof(addr)); 3062 3063 if (security_sctp_bind_connect(asoc->ep->base.sk, 3064 SCTP_PARAM_ADD_IP, 3065 (struct sockaddr *)&addr, 3066 af->sockaddr_len)) 3067 return SCTP_ERROR_REQ_REFUSED; 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 if (security_sctp_bind_connect(asoc->ep->base.sk, 3136 SCTP_PARAM_SET_PRIMARY, 3137 (struct sockaddr *)&addr, 3138 af->sockaddr_len)) 3139 return SCTP_ERROR_REQ_REFUSED; 3140 3141 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3142 if (!peer) 3143 return SCTP_ERROR_DNS_FAILED; 3144 3145 sctp_assoc_set_primary(asoc, peer); 3146 break; 3147 } 3148 3149 return SCTP_ERROR_NO_ERROR; 3150 } 3151 3152 /* Verify the ASCONF packet before we process it. */ 3153 bool sctp_verify_asconf(const struct sctp_association *asoc, 3154 struct sctp_chunk *chunk, bool addr_param_needed, 3155 struct sctp_paramhdr **errp) 3156 { 3157 struct sctp_addip_chunk *addip; 3158 bool addr_param_seen = false; 3159 union sctp_params param; 3160 3161 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr; 3162 sctp_walk_params(param, addip, addip_hdr.params) { 3163 size_t length = ntohs(param.p->length); 3164 3165 *errp = param.p; 3166 switch (param.p->type) { 3167 case SCTP_PARAM_ERR_CAUSE: 3168 break; 3169 case SCTP_PARAM_IPV4_ADDRESS: 3170 if (length != sizeof(struct sctp_ipv4addr_param)) 3171 return false; 3172 /* ensure there is only one addr param and it's in the 3173 * beginning of addip_hdr params, or we reject it. 3174 */ 3175 if (param.v != addip->addip_hdr.params) 3176 return false; 3177 addr_param_seen = true; 3178 break; 3179 case SCTP_PARAM_IPV6_ADDRESS: 3180 if (length != sizeof(struct sctp_ipv6addr_param)) 3181 return false; 3182 if (param.v != addip->addip_hdr.params) 3183 return false; 3184 addr_param_seen = true; 3185 break; 3186 case SCTP_PARAM_ADD_IP: 3187 case SCTP_PARAM_DEL_IP: 3188 case SCTP_PARAM_SET_PRIMARY: 3189 /* In ASCONF chunks, these need to be first. */ 3190 if (addr_param_needed && !addr_param_seen) 3191 return false; 3192 length = ntohs(param.addip->param_hdr.length); 3193 if (length < sizeof(struct sctp_addip_param) + 3194 sizeof(**errp)) 3195 return false; 3196 break; 3197 case SCTP_PARAM_SUCCESS_REPORT: 3198 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3199 if (length != sizeof(struct sctp_addip_param)) 3200 return false; 3201 break; 3202 default: 3203 /* This is unkown to us, reject! */ 3204 return false; 3205 } 3206 } 3207 3208 /* Remaining sanity checks. */ 3209 if (addr_param_needed && !addr_param_seen) 3210 return false; 3211 if (!addr_param_needed && addr_param_seen) 3212 return false; 3213 if (param.v != chunk->chunk_end) 3214 return false; 3215 3216 return true; 3217 } 3218 3219 /* Process an incoming ASCONF chunk with the next expected serial no. and 3220 * return an ASCONF_ACK chunk to be sent in response. 3221 */ 3222 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3223 struct sctp_chunk *asconf) 3224 { 3225 union sctp_addr_param *addr_param; 3226 struct sctp_addip_chunk *addip; 3227 struct sctp_chunk *asconf_ack; 3228 bool all_param_pass = true; 3229 struct sctp_addiphdr *hdr; 3230 int length = 0, chunk_len; 3231 union sctp_params param; 3232 __be16 err_code; 3233 __u32 serial; 3234 3235 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr; 3236 chunk_len = ntohs(asconf->chunk_hdr->length) - 3237 sizeof(struct sctp_chunkhdr); 3238 hdr = (struct sctp_addiphdr *)asconf->skb->data; 3239 serial = ntohl(hdr->serial); 3240 3241 /* Skip the addiphdr and store a pointer to address parameter. */ 3242 length = sizeof(*hdr); 3243 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3244 chunk_len -= length; 3245 3246 /* Skip the address parameter and store a pointer to the first 3247 * asconf parameter. 3248 */ 3249 length = ntohs(addr_param->p.length); 3250 chunk_len -= length; 3251 3252 /* create an ASCONF_ACK chunk. 3253 * Based on the definitions of parameters, we know that the size of 3254 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3255 * parameters. 3256 */ 3257 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3258 if (!asconf_ack) 3259 goto done; 3260 3261 /* Process the TLVs contained within the ASCONF chunk. */ 3262 sctp_walk_params(param, addip, addip_hdr.params) { 3263 /* Skip preceeding address parameters. */ 3264 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 3265 param.p->type == SCTP_PARAM_IPV6_ADDRESS) 3266 continue; 3267 3268 err_code = sctp_process_asconf_param(asoc, asconf, 3269 param.addip); 3270 /* ADDIP 4.1 A7) 3271 * If an error response is received for a TLV parameter, 3272 * all TLVs with no response before the failed TLV are 3273 * considered successful if not reported. All TLVs after 3274 * the failed response are considered unsuccessful unless 3275 * a specific success indication is present for the parameter. 3276 */ 3277 if (err_code != SCTP_ERROR_NO_ERROR) 3278 all_param_pass = false; 3279 if (!all_param_pass) 3280 sctp_add_asconf_response(asconf_ack, param.addip->crr_id, 3281 err_code, param.addip); 3282 3283 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3284 * an IP address sends an 'Out of Resource' in its response, it 3285 * MUST also fail any subsequent add or delete requests bundled 3286 * in the ASCONF. 3287 */ 3288 if (err_code == SCTP_ERROR_RSRC_LOW) 3289 goto done; 3290 } 3291 done: 3292 asoc->peer.addip_serial++; 3293 3294 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3295 * after freeing the reference to old asconf ack if any. 3296 */ 3297 if (asconf_ack) { 3298 sctp_chunk_hold(asconf_ack); 3299 list_add_tail(&asconf_ack->transmitted_list, 3300 &asoc->asconf_ack_list); 3301 } 3302 3303 return asconf_ack; 3304 } 3305 3306 /* Process a asconf parameter that is successfully acked. */ 3307 static void sctp_asconf_param_success(struct sctp_association *asoc, 3308 struct sctp_addip_param *asconf_param) 3309 { 3310 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3311 union sctp_addr_param *addr_param; 3312 struct sctp_sockaddr_entry *saddr; 3313 struct sctp_transport *transport; 3314 union sctp_addr addr; 3315 struct sctp_af *af; 3316 3317 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3318 3319 /* We have checked the packet before, so we do not check again. */ 3320 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3321 af->from_addr_param(&addr, addr_param, htons(bp->port), 0); 3322 3323 switch (asconf_param->param_hdr.type) { 3324 case SCTP_PARAM_ADD_IP: 3325 /* This is always done in BH context with a socket lock 3326 * held, so the list can not change. 3327 */ 3328 local_bh_disable(); 3329 list_for_each_entry(saddr, &bp->address_list, list) { 3330 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3331 saddr->state = SCTP_ADDR_SRC; 3332 } 3333 local_bh_enable(); 3334 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3335 transports) { 3336 sctp_transport_dst_release(transport); 3337 } 3338 break; 3339 case SCTP_PARAM_DEL_IP: 3340 local_bh_disable(); 3341 sctp_del_bind_addr(bp, &addr); 3342 if (asoc->asconf_addr_del_pending != NULL && 3343 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3344 kfree(asoc->asconf_addr_del_pending); 3345 asoc->asconf_addr_del_pending = NULL; 3346 } 3347 local_bh_enable(); 3348 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3349 transports) { 3350 sctp_transport_dst_release(transport); 3351 } 3352 break; 3353 default: 3354 break; 3355 } 3356 } 3357 3358 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3359 * for the given asconf parameter. If there is no response for this parameter, 3360 * return the error code based on the third argument 'no_err'. 3361 * ADDIP 4.1 3362 * A7) If an error response is received for a TLV parameter, all TLVs with no 3363 * response before the failed TLV are considered successful if not reported. 3364 * All TLVs after the failed response are considered unsuccessful unless a 3365 * specific success indication is present for the parameter. 3366 */ 3367 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3368 struct sctp_addip_param *asconf_param, 3369 int no_err) 3370 { 3371 struct sctp_addip_param *asconf_ack_param; 3372 struct sctp_errhdr *err_param; 3373 int asconf_ack_len; 3374 __be16 err_code; 3375 int length; 3376 3377 if (no_err) 3378 err_code = SCTP_ERROR_NO_ERROR; 3379 else 3380 err_code = SCTP_ERROR_REQ_REFUSED; 3381 3382 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3383 sizeof(struct sctp_chunkhdr); 3384 3385 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3386 * the first asconf_ack parameter. 3387 */ 3388 length = sizeof(struct sctp_addiphdr); 3389 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data + 3390 length); 3391 asconf_ack_len -= length; 3392 3393 while (asconf_ack_len > 0) { 3394 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3395 switch (asconf_ack_param->param_hdr.type) { 3396 case SCTP_PARAM_SUCCESS_REPORT: 3397 return SCTP_ERROR_NO_ERROR; 3398 case SCTP_PARAM_ERR_CAUSE: 3399 length = sizeof(*asconf_ack_param); 3400 err_param = (void *)asconf_ack_param + length; 3401 asconf_ack_len -= length; 3402 if (asconf_ack_len > 0) 3403 return err_param->cause; 3404 else 3405 return SCTP_ERROR_INV_PARAM; 3406 break; 3407 default: 3408 return SCTP_ERROR_INV_PARAM; 3409 } 3410 } 3411 3412 length = ntohs(asconf_ack_param->param_hdr.length); 3413 asconf_ack_param = (void *)asconf_ack_param + length; 3414 asconf_ack_len -= length; 3415 } 3416 3417 return err_code; 3418 } 3419 3420 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3421 int sctp_process_asconf_ack(struct sctp_association *asoc, 3422 struct sctp_chunk *asconf_ack) 3423 { 3424 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3425 struct sctp_addip_param *asconf_param; 3426 __be16 err_code = SCTP_ERROR_NO_ERROR; 3427 union sctp_addr_param *addr_param; 3428 int asconf_len = asconf->skb->len; 3429 int all_param_pass = 0; 3430 int length = 0; 3431 int no_err = 1; 3432 int retval = 0; 3433 3434 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3435 * a pointer to address parameter. 3436 */ 3437 length = sizeof(struct sctp_addip_chunk); 3438 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3439 asconf_len -= length; 3440 3441 /* Skip the address parameter in the last asconf sent and store a 3442 * pointer to the first asconf parameter. 3443 */ 3444 length = ntohs(addr_param->p.length); 3445 asconf_param = (void *)addr_param + length; 3446 asconf_len -= length; 3447 3448 /* ADDIP 4.1 3449 * A8) If there is no response(s) to specific TLV parameter(s), and no 3450 * failures are indicated, then all request(s) are considered 3451 * successful. 3452 */ 3453 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr)) 3454 all_param_pass = 1; 3455 3456 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3457 while (asconf_len > 0) { 3458 if (all_param_pass) 3459 err_code = SCTP_ERROR_NO_ERROR; 3460 else { 3461 err_code = sctp_get_asconf_response(asconf_ack, 3462 asconf_param, 3463 no_err); 3464 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3465 no_err = 0; 3466 } 3467 3468 switch (err_code) { 3469 case SCTP_ERROR_NO_ERROR: 3470 sctp_asconf_param_success(asoc, asconf_param); 3471 break; 3472 3473 case SCTP_ERROR_RSRC_LOW: 3474 retval = 1; 3475 break; 3476 3477 case SCTP_ERROR_UNKNOWN_PARAM: 3478 /* Disable sending this type of asconf parameter in 3479 * future. 3480 */ 3481 asoc->peer.addip_disabled_mask |= 3482 asconf_param->param_hdr.type; 3483 break; 3484 3485 case SCTP_ERROR_REQ_REFUSED: 3486 case SCTP_ERROR_DEL_LAST_IP: 3487 case SCTP_ERROR_DEL_SRC_IP: 3488 default: 3489 break; 3490 } 3491 3492 /* Skip the processed asconf parameter and move to the next 3493 * one. 3494 */ 3495 length = ntohs(asconf_param->param_hdr.length); 3496 asconf_param = (void *)asconf_param + length; 3497 asconf_len -= length; 3498 } 3499 3500 if (no_err && asoc->src_out_of_asoc_ok) { 3501 asoc->src_out_of_asoc_ok = 0; 3502 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3503 } 3504 3505 /* Free the cached last sent asconf chunk. */ 3506 list_del_init(&asconf->transmitted_list); 3507 sctp_chunk_free(asconf); 3508 asoc->addip_last_asconf = NULL; 3509 3510 return retval; 3511 } 3512 3513 /* Make a FWD TSN chunk. */ 3514 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3515 __u32 new_cum_tsn, size_t nstreams, 3516 struct sctp_fwdtsn_skip *skiplist) 3517 { 3518 struct sctp_chunk *retval = NULL; 3519 struct sctp_fwdtsn_hdr ftsn_hdr; 3520 struct sctp_fwdtsn_skip skip; 3521 size_t hint; 3522 int i; 3523 3524 hint = (nstreams + 1) * sizeof(__u32); 3525 3526 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC); 3527 3528 if (!retval) 3529 return NULL; 3530 3531 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3532 retval->subh.fwdtsn_hdr = 3533 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3534 3535 for (i = 0; i < nstreams; i++) { 3536 skip.stream = skiplist[i].stream; 3537 skip.ssn = skiplist[i].ssn; 3538 sctp_addto_chunk(retval, sizeof(skip), &skip); 3539 } 3540 3541 return retval; 3542 } 3543 3544 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc, 3545 __u32 new_cum_tsn, size_t nstreams, 3546 struct sctp_ifwdtsn_skip *skiplist) 3547 { 3548 struct sctp_chunk *retval = NULL; 3549 struct sctp_ifwdtsn_hdr ftsn_hdr; 3550 size_t hint; 3551 3552 hint = (nstreams + 1) * sizeof(__u32); 3553 3554 retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint, 3555 GFP_ATOMIC); 3556 if (!retval) 3557 return NULL; 3558 3559 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3560 retval->subh.ifwdtsn_hdr = 3561 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3562 3563 sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist); 3564 3565 return retval; 3566 } 3567 3568 /* RE-CONFIG 3.1 (RE-CONFIG chunk) 3569 * 0 1 2 3 3570 * 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 3571 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3572 * | Type = 130 | Chunk Flags | Chunk Length | 3573 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3574 * \ \ 3575 * / Re-configuration Parameter / 3576 * \ \ 3577 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3578 * \ \ 3579 * / Re-configuration Parameter (optional) / 3580 * \ \ 3581 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3582 */ 3583 static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc, 3584 int length) 3585 { 3586 struct sctp_reconf_chunk *reconf; 3587 struct sctp_chunk *retval; 3588 3589 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length, 3590 GFP_ATOMIC); 3591 if (!retval) 3592 return NULL; 3593 3594 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr; 3595 retval->param_hdr.v = reconf->params; 3596 3597 return retval; 3598 } 3599 3600 /* RE-CONFIG 4.1 (STREAM OUT RESET) 3601 * 0 1 2 3 3602 * 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 3603 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3604 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N | 3605 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3606 * | Re-configuration Request Sequence Number | 3607 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3608 * | Re-configuration Response Sequence Number | 3609 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3610 * | Sender's Last Assigned TSN | 3611 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3612 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3613 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3614 * / ...... / 3615 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3616 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3617 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3618 * 3619 * RE-CONFIG 4.2 (STREAM IN RESET) 3620 * 0 1 2 3 3621 * 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 3622 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3623 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N | 3624 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3625 * | Re-configuration Request Sequence Number | 3626 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3627 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3628 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3629 * / ...... / 3630 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3631 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3632 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3633 */ 3634 struct sctp_chunk *sctp_make_strreset_req( 3635 const struct sctp_association *asoc, 3636 __u16 stream_num, __be16 *stream_list, 3637 bool out, bool in) 3638 { 3639 __u16 stream_len = stream_num * sizeof(__u16); 3640 struct sctp_strreset_outreq outreq; 3641 struct sctp_strreset_inreq inreq; 3642 struct sctp_chunk *retval; 3643 __u16 outlen, inlen; 3644 3645 outlen = (sizeof(outreq) + stream_len) * out; 3646 inlen = (sizeof(inreq) + stream_len) * in; 3647 3648 retval = sctp_make_reconf(asoc, outlen + inlen); 3649 if (!retval) 3650 return NULL; 3651 3652 if (outlen) { 3653 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST; 3654 outreq.param_hdr.length = htons(outlen); 3655 outreq.request_seq = htonl(asoc->strreset_outseq); 3656 outreq.response_seq = htonl(asoc->strreset_inseq - 1); 3657 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1); 3658 3659 sctp_addto_chunk(retval, sizeof(outreq), &outreq); 3660 3661 if (stream_len) 3662 sctp_addto_chunk(retval, stream_len, stream_list); 3663 } 3664 3665 if (inlen) { 3666 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST; 3667 inreq.param_hdr.length = htons(inlen); 3668 inreq.request_seq = htonl(asoc->strreset_outseq + out); 3669 3670 sctp_addto_chunk(retval, sizeof(inreq), &inreq); 3671 3672 if (stream_len) 3673 sctp_addto_chunk(retval, stream_len, stream_list); 3674 } 3675 3676 return retval; 3677 } 3678 3679 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL) 3680 * 0 1 2 3 3681 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 3682 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3683 * | Parameter Type = 15 | Parameter Length = 8 | 3684 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3685 * | Re-configuration Request Sequence Number | 3686 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3687 */ 3688 struct sctp_chunk *sctp_make_strreset_tsnreq( 3689 const struct sctp_association *asoc) 3690 { 3691 struct sctp_strreset_tsnreq tsnreq; 3692 __u16 length = sizeof(tsnreq); 3693 struct sctp_chunk *retval; 3694 3695 retval = sctp_make_reconf(asoc, length); 3696 if (!retval) 3697 return NULL; 3698 3699 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST; 3700 tsnreq.param_hdr.length = htons(length); 3701 tsnreq.request_seq = htonl(asoc->strreset_outseq); 3702 3703 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq); 3704 3705 return retval; 3706 } 3707 3708 /* RE-CONFIG 4.5/4.6 (ADD STREAM) 3709 * 0 1 2 3 3710 * 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 3711 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3712 * | Parameter Type = 17 | Parameter Length = 12 | 3713 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3714 * | Re-configuration Request Sequence Number | 3715 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3716 * | Number of new streams | Reserved | 3717 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3718 */ 3719 struct sctp_chunk *sctp_make_strreset_addstrm( 3720 const struct sctp_association *asoc, 3721 __u16 out, __u16 in) 3722 { 3723 struct sctp_strreset_addstrm addstrm; 3724 __u16 size = sizeof(addstrm); 3725 struct sctp_chunk *retval; 3726 3727 retval = sctp_make_reconf(asoc, (!!out + !!in) * size); 3728 if (!retval) 3729 return NULL; 3730 3731 if (out) { 3732 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS; 3733 addstrm.param_hdr.length = htons(size); 3734 addstrm.number_of_streams = htons(out); 3735 addstrm.request_seq = htonl(asoc->strreset_outseq); 3736 addstrm.reserved = 0; 3737 3738 sctp_addto_chunk(retval, size, &addstrm); 3739 } 3740 3741 if (in) { 3742 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS; 3743 addstrm.param_hdr.length = htons(size); 3744 addstrm.number_of_streams = htons(in); 3745 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out); 3746 addstrm.reserved = 0; 3747 3748 sctp_addto_chunk(retval, size, &addstrm); 3749 } 3750 3751 return retval; 3752 } 3753 3754 /* RE-CONFIG 4.4 (RESP) 3755 * 0 1 2 3 3756 * 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 3757 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3758 * | Parameter Type = 16 | Parameter Length | 3759 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3760 * | Re-configuration Response Sequence Number | 3761 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3762 * | Result | 3763 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3764 */ 3765 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc, 3766 __u32 result, __u32 sn) 3767 { 3768 struct sctp_strreset_resp resp; 3769 __u16 length = sizeof(resp); 3770 struct sctp_chunk *retval; 3771 3772 retval = sctp_make_reconf(asoc, length); 3773 if (!retval) 3774 return NULL; 3775 3776 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3777 resp.param_hdr.length = htons(length); 3778 resp.response_seq = htonl(sn); 3779 resp.result = htonl(result); 3780 3781 sctp_addto_chunk(retval, sizeof(resp), &resp); 3782 3783 return retval; 3784 } 3785 3786 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP) 3787 * 0 1 2 3 3788 * 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 3789 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3790 * | Parameter Type = 16 | Parameter Length | 3791 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3792 * | Re-configuration Response Sequence Number | 3793 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3794 * | Result | 3795 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3796 * | Sender's Next TSN (optional) | 3797 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3798 * | Receiver's Next TSN (optional) | 3799 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3800 */ 3801 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc, 3802 __u32 result, __u32 sn, 3803 __u32 sender_tsn, 3804 __u32 receiver_tsn) 3805 { 3806 struct sctp_strreset_resptsn tsnresp; 3807 __u16 length = sizeof(tsnresp); 3808 struct sctp_chunk *retval; 3809 3810 retval = sctp_make_reconf(asoc, length); 3811 if (!retval) 3812 return NULL; 3813 3814 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3815 tsnresp.param_hdr.length = htons(length); 3816 3817 tsnresp.response_seq = htonl(sn); 3818 tsnresp.result = htonl(result); 3819 tsnresp.senders_next_tsn = htonl(sender_tsn); 3820 tsnresp.receivers_next_tsn = htonl(receiver_tsn); 3821 3822 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp); 3823 3824 return retval; 3825 } 3826 3827 bool sctp_verify_reconf(const struct sctp_association *asoc, 3828 struct sctp_chunk *chunk, 3829 struct sctp_paramhdr **errp) 3830 { 3831 struct sctp_reconf_chunk *hdr; 3832 union sctp_params param; 3833 __be16 last = 0; 3834 __u16 cnt = 0; 3835 3836 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; 3837 sctp_walk_params(param, hdr, params) { 3838 __u16 length = ntohs(param.p->length); 3839 3840 *errp = param.p; 3841 if (cnt++ > 2) 3842 return false; 3843 switch (param.p->type) { 3844 case SCTP_PARAM_RESET_OUT_REQUEST: 3845 if (length < sizeof(struct sctp_strreset_outreq) || 3846 (last && last != SCTP_PARAM_RESET_RESPONSE && 3847 last != SCTP_PARAM_RESET_IN_REQUEST)) 3848 return false; 3849 break; 3850 case SCTP_PARAM_RESET_IN_REQUEST: 3851 if (length < sizeof(struct sctp_strreset_inreq) || 3852 (last && last != SCTP_PARAM_RESET_OUT_REQUEST)) 3853 return false; 3854 break; 3855 case SCTP_PARAM_RESET_RESPONSE: 3856 if ((length != sizeof(struct sctp_strreset_resp) && 3857 length != sizeof(struct sctp_strreset_resptsn)) || 3858 (last && last != SCTP_PARAM_RESET_RESPONSE && 3859 last != SCTP_PARAM_RESET_OUT_REQUEST)) 3860 return false; 3861 break; 3862 case SCTP_PARAM_RESET_TSN_REQUEST: 3863 if (length != 3864 sizeof(struct sctp_strreset_tsnreq) || last) 3865 return false; 3866 break; 3867 case SCTP_PARAM_RESET_ADD_IN_STREAMS: 3868 if (length != sizeof(struct sctp_strreset_addstrm) || 3869 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS)) 3870 return false; 3871 break; 3872 case SCTP_PARAM_RESET_ADD_OUT_STREAMS: 3873 if (length != sizeof(struct sctp_strreset_addstrm) || 3874 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS)) 3875 return false; 3876 break; 3877 default: 3878 return false; 3879 } 3880 3881 last = param.p->type; 3882 } 3883 3884 return true; 3885 } 3886