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 struct crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac; 1670 int err; 1671 1672 /* Sign the message. */ 1673 err = crypto_shash_setkey(tfm, ep->secret_key, 1674 sizeof(ep->secret_key)) ?: 1675 crypto_shash_tfm_digest(tfm, (u8 *)&cookie->c, bodysize, 1676 cookie->signature); 1677 if (err) 1678 goto free_cookie; 1679 } 1680 1681 return retval; 1682 1683 free_cookie: 1684 kfree(retval); 1685 nodata: 1686 *cookie_len = 0; 1687 return NULL; 1688 } 1689 1690 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1691 struct sctp_association *sctp_unpack_cookie( 1692 const struct sctp_endpoint *ep, 1693 const struct sctp_association *asoc, 1694 struct sctp_chunk *chunk, gfp_t gfp, 1695 int *error, struct sctp_chunk **errp) 1696 { 1697 struct sctp_association *retval = NULL; 1698 int headersize, bodysize, fixed_size; 1699 struct sctp_signed_cookie *cookie; 1700 struct sk_buff *skb = chunk->skb; 1701 struct sctp_cookie *bear_cookie; 1702 __u8 *digest = ep->digest; 1703 enum sctp_scope scope; 1704 unsigned int len; 1705 ktime_t kt; 1706 1707 /* Header size is static data prior to the actual cookie, including 1708 * any padding. 1709 */ 1710 headersize = sizeof(struct sctp_chunkhdr) + 1711 (sizeof(struct sctp_signed_cookie) - 1712 sizeof(struct sctp_cookie)); 1713 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1714 fixed_size = headersize + sizeof(struct sctp_cookie); 1715 1716 /* Verify that the chunk looks like it even has a cookie. 1717 * There must be enough room for our cookie and our peer's 1718 * INIT chunk. 1719 */ 1720 len = ntohs(chunk->chunk_hdr->length); 1721 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1722 goto malformed; 1723 1724 /* Verify that the cookie has been padded out. */ 1725 if (bodysize % SCTP_COOKIE_MULTIPLE) 1726 goto malformed; 1727 1728 /* Process the cookie. */ 1729 cookie = chunk->subh.cookie_hdr; 1730 bear_cookie = &cookie->c; 1731 1732 if (!sctp_sk(ep->base.sk)->hmac) 1733 goto no_hmac; 1734 1735 /* Check the signature. */ 1736 { 1737 struct crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac; 1738 int err; 1739 1740 err = crypto_shash_setkey(tfm, ep->secret_key, 1741 sizeof(ep->secret_key)) ?: 1742 crypto_shash_tfm_digest(tfm, (u8 *)bear_cookie, bodysize, 1743 digest); 1744 if (err) { 1745 *error = -SCTP_IERROR_NOMEM; 1746 goto fail; 1747 } 1748 } 1749 1750 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1751 *error = -SCTP_IERROR_BAD_SIG; 1752 goto fail; 1753 } 1754 1755 no_hmac: 1756 /* IG Section 2.35.2: 1757 * 3) Compare the port numbers and the verification tag contained 1758 * within the COOKIE ECHO chunk to the actual port numbers and the 1759 * verification tag within the SCTP common header of the received 1760 * packet. If these values do not match the packet MUST be silently 1761 * discarded, 1762 */ 1763 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1764 *error = -SCTP_IERROR_BAD_TAG; 1765 goto fail; 1766 } 1767 1768 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1769 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1770 *error = -SCTP_IERROR_BAD_PORTS; 1771 goto fail; 1772 } 1773 1774 /* Check to see if the cookie is stale. If there is already 1775 * an association, there is no need to check cookie's expiration 1776 * for init collision case of lost COOKIE ACK. 1777 * If skb has been timestamped, then use the stamp, otherwise 1778 * use current time. This introduces a small possibility that 1779 * that a cookie may be considered expired, but his would only slow 1780 * down the new association establishment instead of every packet. 1781 */ 1782 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1783 kt = skb_get_ktime(skb); 1784 else 1785 kt = ktime_get_real(); 1786 1787 if (!asoc && ktime_before(bear_cookie->expiration, kt)) { 1788 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); 1789 __be32 n = htonl(usecs); 1790 1791 /* 1792 * Section 3.3.10.3 Stale Cookie Error (3) 1793 * 1794 * Cause of error 1795 * --------------- 1796 * Stale Cookie Error: Indicates the receipt of a valid State 1797 * Cookie that has expired. 1798 */ 1799 *errp = sctp_make_op_error(asoc, chunk, 1800 SCTP_ERROR_STALE_COOKIE, &n, 1801 sizeof(n), 0); 1802 if (*errp) 1803 *error = -SCTP_IERROR_STALE_COOKIE; 1804 else 1805 *error = -SCTP_IERROR_NOMEM; 1806 1807 goto fail; 1808 } 1809 1810 /* Make a new base association. */ 1811 scope = sctp_scope(sctp_source(chunk)); 1812 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1813 if (!retval) { 1814 *error = -SCTP_IERROR_NOMEM; 1815 goto fail; 1816 } 1817 1818 /* Set up our peer's port number. */ 1819 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1820 1821 /* Populate the association from the cookie. */ 1822 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1823 1824 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1825 GFP_ATOMIC) < 0) { 1826 *error = -SCTP_IERROR_NOMEM; 1827 goto fail; 1828 } 1829 1830 /* Also, add the destination address. */ 1831 if (list_empty(&retval->base.bind_addr.address_list)) { 1832 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1833 sizeof(chunk->dest), SCTP_ADDR_SRC, 1834 GFP_ATOMIC); 1835 } 1836 1837 retval->next_tsn = retval->c.initial_tsn; 1838 retval->ctsn_ack_point = retval->next_tsn - 1; 1839 retval->addip_serial = retval->c.initial_tsn; 1840 retval->strreset_outseq = retval->c.initial_tsn; 1841 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1842 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1843 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1844 1845 /* The INIT stuff will be done by the side effects. */ 1846 return retval; 1847 1848 fail: 1849 if (retval) 1850 sctp_association_free(retval); 1851 1852 return NULL; 1853 1854 malformed: 1855 /* Yikes! The packet is either corrupt or deliberately 1856 * malformed. 1857 */ 1858 *error = -SCTP_IERROR_MALFORMED; 1859 goto fail; 1860 } 1861 1862 /******************************************************************** 1863 * 3rd Level Abstractions 1864 ********************************************************************/ 1865 1866 struct __sctp_missing { 1867 __be32 num_missing; 1868 __be16 type; 1869 } __packed; 1870 1871 /* 1872 * Report a missing mandatory parameter. 1873 */ 1874 static int sctp_process_missing_param(const struct sctp_association *asoc, 1875 enum sctp_param paramtype, 1876 struct sctp_chunk *chunk, 1877 struct sctp_chunk **errp) 1878 { 1879 struct __sctp_missing report; 1880 __u16 len; 1881 1882 len = SCTP_PAD4(sizeof(report)); 1883 1884 /* Make an ERROR chunk, preparing enough room for 1885 * returning multiple unknown parameters. 1886 */ 1887 if (!*errp) 1888 *errp = sctp_make_op_error_space(asoc, chunk, len); 1889 1890 if (*errp) { 1891 report.num_missing = htonl(1); 1892 report.type = paramtype; 1893 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1894 sizeof(report)); 1895 sctp_addto_chunk(*errp, sizeof(report), &report); 1896 } 1897 1898 /* Stop processing this chunk. */ 1899 return 0; 1900 } 1901 1902 /* Report an Invalid Mandatory Parameter. */ 1903 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1904 struct sctp_chunk *chunk, 1905 struct sctp_chunk **errp) 1906 { 1907 /* Invalid Mandatory Parameter Error has no payload. */ 1908 1909 if (!*errp) 1910 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1911 1912 if (*errp) 1913 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1914 1915 /* Stop processing this chunk. */ 1916 return 0; 1917 } 1918 1919 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1920 struct sctp_paramhdr *param, 1921 const struct sctp_chunk *chunk, 1922 struct sctp_chunk **errp) 1923 { 1924 /* This is a fatal error. Any accumulated non-fatal errors are 1925 * not reported. 1926 */ 1927 if (*errp) 1928 sctp_chunk_free(*errp); 1929 1930 /* Create an error chunk and fill it in with our payload. */ 1931 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1932 1933 return 0; 1934 } 1935 1936 1937 /* Do not attempt to handle the HOST_NAME parm. However, do 1938 * send back an indicator to the peer. 1939 */ 1940 static int sctp_process_hn_param(const struct sctp_association *asoc, 1941 union sctp_params param, 1942 struct sctp_chunk *chunk, 1943 struct sctp_chunk **errp) 1944 { 1945 __u16 len = ntohs(param.p->length); 1946 1947 /* Processing of the HOST_NAME parameter will generate an 1948 * ABORT. If we've accumulated any non-fatal errors, they 1949 * would be unrecognized parameters and we should not include 1950 * them in the ABORT. 1951 */ 1952 if (*errp) 1953 sctp_chunk_free(*errp); 1954 1955 *errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_DNS_FAILED, 1956 param.v, len, 0); 1957 1958 /* Stop processing this chunk. */ 1959 return 0; 1960 } 1961 1962 static int sctp_verify_ext_param(struct net *net, 1963 const struct sctp_endpoint *ep, 1964 union sctp_params param) 1965 { 1966 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 1967 int have_asconf = 0; 1968 int have_auth = 0; 1969 int i; 1970 1971 for (i = 0; i < num_ext; i++) { 1972 switch (param.ext->chunks[i]) { 1973 case SCTP_CID_AUTH: 1974 have_auth = 1; 1975 break; 1976 case SCTP_CID_ASCONF: 1977 case SCTP_CID_ASCONF_ACK: 1978 have_asconf = 1; 1979 break; 1980 } 1981 } 1982 1983 /* ADD-IP Security: The draft requires us to ABORT or ignore the 1984 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 1985 * only if ADD-IP is turned on and we are not backward-compatible 1986 * mode. 1987 */ 1988 if (net->sctp.addip_noauth) 1989 return 1; 1990 1991 if (ep->asconf_enable && !have_auth && have_asconf) 1992 return 0; 1993 1994 return 1; 1995 } 1996 1997 static void sctp_process_ext_param(struct sctp_association *asoc, 1998 union sctp_params param) 1999 { 2000 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2001 int i; 2002 2003 for (i = 0; i < num_ext; i++) { 2004 switch (param.ext->chunks[i]) { 2005 case SCTP_CID_RECONF: 2006 if (asoc->ep->reconf_enable) 2007 asoc->peer.reconf_capable = 1; 2008 break; 2009 case SCTP_CID_FWD_TSN: 2010 if (asoc->ep->prsctp_enable) 2011 asoc->peer.prsctp_capable = 1; 2012 break; 2013 case SCTP_CID_AUTH: 2014 /* if the peer reports AUTH, assume that he 2015 * supports AUTH. 2016 */ 2017 if (asoc->ep->auth_enable) 2018 asoc->peer.auth_capable = 1; 2019 break; 2020 case SCTP_CID_ASCONF: 2021 case SCTP_CID_ASCONF_ACK: 2022 if (asoc->ep->asconf_enable) 2023 asoc->peer.asconf_capable = 1; 2024 break; 2025 case SCTP_CID_I_DATA: 2026 if (asoc->ep->intl_enable) 2027 asoc->peer.intl_capable = 1; 2028 break; 2029 default: 2030 break; 2031 } 2032 } 2033 } 2034 2035 /* RFC 3.2.1 & the Implementers Guide 2.2. 2036 * 2037 * The Parameter Types are encoded such that the 2038 * highest-order two bits specify the action that must be 2039 * taken if the processing endpoint does not recognize the 2040 * Parameter Type. 2041 * 2042 * 00 - Stop processing this parameter; do not process any further 2043 * parameters within this chunk 2044 * 2045 * 01 - Stop processing this parameter, do not process any further 2046 * parameters within this chunk, and report the unrecognized 2047 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2048 * 2049 * 10 - Skip this parameter and continue processing. 2050 * 2051 * 11 - Skip this parameter and continue processing but 2052 * report the unrecognized parameter in an 2053 * 'Unrecognized Parameter' ERROR chunk. 2054 * 2055 * Return value: 2056 * SCTP_IERROR_NO_ERROR - continue with the chunk 2057 * SCTP_IERROR_ERROR - stop and report an error. 2058 * SCTP_IERROR_NOMEME - out of memory. 2059 */ 2060 static enum sctp_ierror sctp_process_unk_param( 2061 const struct sctp_association *asoc, 2062 union sctp_params param, 2063 struct sctp_chunk *chunk, 2064 struct sctp_chunk **errp) 2065 { 2066 int retval = SCTP_IERROR_NO_ERROR; 2067 2068 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2069 case SCTP_PARAM_ACTION_DISCARD: 2070 retval = SCTP_IERROR_ERROR; 2071 break; 2072 case SCTP_PARAM_ACTION_SKIP: 2073 break; 2074 case SCTP_PARAM_ACTION_DISCARD_ERR: 2075 retval = SCTP_IERROR_ERROR; 2076 /* Fall through */ 2077 case SCTP_PARAM_ACTION_SKIP_ERR: 2078 /* Make an ERROR chunk, preparing enough room for 2079 * returning multiple unknown parameters. 2080 */ 2081 if (!*errp) { 2082 *errp = sctp_make_op_error_limited(asoc, chunk); 2083 if (!*errp) { 2084 /* If there is no memory for generating the 2085 * ERROR report as specified, an ABORT will be 2086 * triggered to the peer and the association 2087 * won't be established. 2088 */ 2089 retval = SCTP_IERROR_NOMEM; 2090 break; 2091 } 2092 } 2093 2094 if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2095 ntohs(param.p->length))) 2096 sctp_addto_chunk(*errp, ntohs(param.p->length), 2097 param.v); 2098 break; 2099 default: 2100 break; 2101 } 2102 2103 return retval; 2104 } 2105 2106 /* Verify variable length parameters 2107 * Return values: 2108 * SCTP_IERROR_ABORT - trigger an ABORT 2109 * SCTP_IERROR_NOMEM - out of memory (abort) 2110 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2111 * SCTP_IERROR_NO_ERROR - continue with the chunk 2112 */ 2113 static enum sctp_ierror sctp_verify_param(struct net *net, 2114 const struct sctp_endpoint *ep, 2115 const struct sctp_association *asoc, 2116 union sctp_params param, 2117 enum sctp_cid cid, 2118 struct sctp_chunk *chunk, 2119 struct sctp_chunk **err_chunk) 2120 { 2121 struct sctp_hmac_algo_param *hmacs; 2122 int retval = SCTP_IERROR_NO_ERROR; 2123 __u16 n_elt, id = 0; 2124 int i; 2125 2126 /* FIXME - This routine is not looking at each parameter per the 2127 * chunk type, i.e., unrecognized parameters should be further 2128 * identified based on the chunk id. 2129 */ 2130 2131 switch (param.p->type) { 2132 case SCTP_PARAM_IPV4_ADDRESS: 2133 case SCTP_PARAM_IPV6_ADDRESS: 2134 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2135 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2136 case SCTP_PARAM_STATE_COOKIE: 2137 case SCTP_PARAM_HEARTBEAT_INFO: 2138 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2139 case SCTP_PARAM_ECN_CAPABLE: 2140 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2141 break; 2142 2143 case SCTP_PARAM_SUPPORTED_EXT: 2144 if (!sctp_verify_ext_param(net, ep, param)) 2145 return SCTP_IERROR_ABORT; 2146 break; 2147 2148 case SCTP_PARAM_SET_PRIMARY: 2149 if (ep->asconf_enable) 2150 break; 2151 goto unhandled; 2152 2153 case SCTP_PARAM_HOST_NAME_ADDRESS: 2154 /* Tell the peer, we won't support this param. */ 2155 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2156 retval = SCTP_IERROR_ABORT; 2157 break; 2158 2159 case SCTP_PARAM_FWD_TSN_SUPPORT: 2160 if (ep->prsctp_enable) 2161 break; 2162 goto unhandled; 2163 2164 case SCTP_PARAM_RANDOM: 2165 if (!ep->auth_enable) 2166 goto unhandled; 2167 2168 /* SCTP-AUTH: Secion 6.1 2169 * If the random number is not 32 byte long the association 2170 * MUST be aborted. The ABORT chunk SHOULD contain the error 2171 * cause 'Protocol Violation'. 2172 */ 2173 if (SCTP_AUTH_RANDOM_LENGTH != ntohs(param.p->length) - 2174 sizeof(struct sctp_paramhdr)) { 2175 sctp_process_inv_paramlength(asoc, param.p, 2176 chunk, err_chunk); 2177 retval = SCTP_IERROR_ABORT; 2178 } 2179 break; 2180 2181 case SCTP_PARAM_CHUNKS: 2182 if (!ep->auth_enable) 2183 goto unhandled; 2184 2185 /* SCTP-AUTH: Section 3.2 2186 * The CHUNKS parameter MUST be included once in the INIT or 2187 * INIT-ACK chunk if the sender wants to receive authenticated 2188 * chunks. Its maximum length is 260 bytes. 2189 */ 2190 if (260 < ntohs(param.p->length)) { 2191 sctp_process_inv_paramlength(asoc, param.p, 2192 chunk, err_chunk); 2193 retval = SCTP_IERROR_ABORT; 2194 } 2195 break; 2196 2197 case SCTP_PARAM_HMAC_ALGO: 2198 if (!ep->auth_enable) 2199 goto unhandled; 2200 2201 hmacs = (struct sctp_hmac_algo_param *)param.p; 2202 n_elt = (ntohs(param.p->length) - 2203 sizeof(struct sctp_paramhdr)) >> 1; 2204 2205 /* SCTP-AUTH: Section 6.1 2206 * The HMAC algorithm based on SHA-1 MUST be supported and 2207 * included in the HMAC-ALGO parameter. 2208 */ 2209 for (i = 0; i < n_elt; i++) { 2210 id = ntohs(hmacs->hmac_ids[i]); 2211 2212 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2213 break; 2214 } 2215 2216 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2217 sctp_process_inv_paramlength(asoc, param.p, chunk, 2218 err_chunk); 2219 retval = SCTP_IERROR_ABORT; 2220 } 2221 break; 2222 unhandled: 2223 default: 2224 pr_debug("%s: unrecognized param:%d for chunk:%d\n", 2225 __func__, ntohs(param.p->type), cid); 2226 2227 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2228 break; 2229 } 2230 return retval; 2231 } 2232 2233 /* Verify the INIT packet before we process it. */ 2234 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 2235 const struct sctp_association *asoc, enum sctp_cid cid, 2236 struct sctp_init_chunk *peer_init, 2237 struct sctp_chunk *chunk, struct sctp_chunk **errp) 2238 { 2239 union sctp_params param; 2240 bool has_cookie = false; 2241 int result; 2242 2243 /* Check for missing mandatory parameters. Note: Initial TSN is 2244 * also mandatory, but is not checked here since the valid range 2245 * is 0..2**32-1. RFC4960, section 3.3.3. 2246 */ 2247 if (peer_init->init_hdr.num_outbound_streams == 0 || 2248 peer_init->init_hdr.num_inbound_streams == 0 || 2249 peer_init->init_hdr.init_tag == 0 || 2250 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) 2251 return sctp_process_inv_mandatory(asoc, chunk, errp); 2252 2253 sctp_walk_params(param, peer_init, init_hdr.params) { 2254 if (param.p->type == SCTP_PARAM_STATE_COOKIE) 2255 has_cookie = true; 2256 } 2257 2258 /* There is a possibility that a parameter length was bad and 2259 * in that case we would have stoped walking the parameters. 2260 * The current param.p would point at the bad one. 2261 * Current consensus on the mailing list is to generate a PROTOCOL 2262 * VIOLATION error. We build the ERROR chunk here and let the normal 2263 * error handling code build and send the packet. 2264 */ 2265 if (param.v != (void *)chunk->chunk_end) 2266 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2267 2268 /* The only missing mandatory param possible today is 2269 * the state cookie for an INIT-ACK chunk. 2270 */ 2271 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2272 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2273 chunk, errp); 2274 2275 /* Verify all the variable length parameters */ 2276 sctp_walk_params(param, peer_init, init_hdr.params) { 2277 result = sctp_verify_param(net, ep, asoc, param, cid, 2278 chunk, errp); 2279 switch (result) { 2280 case SCTP_IERROR_ABORT: 2281 case SCTP_IERROR_NOMEM: 2282 return 0; 2283 case SCTP_IERROR_ERROR: 2284 return 1; 2285 case SCTP_IERROR_NO_ERROR: 2286 default: 2287 break; 2288 } 2289 2290 } /* for (loop through all parameters) */ 2291 2292 return 1; 2293 } 2294 2295 /* Unpack the parameters in an INIT packet into an association. 2296 * Returns 0 on failure, else success. 2297 * FIXME: This is an association method. 2298 */ 2299 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2300 const union sctp_addr *peer_addr, 2301 struct sctp_init_chunk *peer_init, gfp_t gfp) 2302 { 2303 struct sctp_transport *transport; 2304 struct list_head *pos, *temp; 2305 union sctp_params param; 2306 union sctp_addr addr; 2307 struct sctp_af *af; 2308 int src_match = 0; 2309 2310 /* We must include the address that the INIT packet came from. 2311 * This is the only address that matters for an INIT packet. 2312 * When processing a COOKIE ECHO, we retrieve the from address 2313 * of the INIT from the cookie. 2314 */ 2315 2316 /* This implementation defaults to making the first transport 2317 * added as the primary transport. The source address seems to 2318 * be a a better choice than any of the embedded addresses. 2319 */ 2320 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2321 goto nomem; 2322 2323 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2324 src_match = 1; 2325 2326 /* Process the initialization parameters. */ 2327 sctp_walk_params(param, peer_init, init_hdr.params) { 2328 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2329 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2330 af = sctp_get_af_specific(param_type2af(param.p->type)); 2331 af->from_addr_param(&addr, param.addr, 2332 chunk->sctp_hdr->source, 0); 2333 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2334 src_match = 1; 2335 } 2336 2337 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2338 goto clean_up; 2339 } 2340 2341 /* source address of chunk may not match any valid address */ 2342 if (!src_match) 2343 goto clean_up; 2344 2345 /* AUTH: After processing the parameters, make sure that we 2346 * have all the required info to potentially do authentications. 2347 */ 2348 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2349 !asoc->peer.peer_hmacs)) 2350 asoc->peer.auth_capable = 0; 2351 2352 /* In a non-backward compatible mode, if the peer claims 2353 * support for ADD-IP but not AUTH, the ADD-IP spec states 2354 * that we MUST ABORT the association. Section 6. The section 2355 * also give us an option to silently ignore the packet, which 2356 * is what we'll do here. 2357 */ 2358 if (!asoc->base.net->sctp.addip_noauth && 2359 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2360 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2361 SCTP_PARAM_DEL_IP | 2362 SCTP_PARAM_SET_PRIMARY); 2363 asoc->peer.asconf_capable = 0; 2364 goto clean_up; 2365 } 2366 2367 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2368 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2369 transport = list_entry(pos, struct sctp_transport, transports); 2370 if (transport->state == SCTP_UNKNOWN) { 2371 sctp_assoc_rm_peer(asoc, transport); 2372 } 2373 } 2374 2375 /* The fixed INIT headers are always in network byte 2376 * order. 2377 */ 2378 asoc->peer.i.init_tag = 2379 ntohl(peer_init->init_hdr.init_tag); 2380 asoc->peer.i.a_rwnd = 2381 ntohl(peer_init->init_hdr.a_rwnd); 2382 asoc->peer.i.num_outbound_streams = 2383 ntohs(peer_init->init_hdr.num_outbound_streams); 2384 asoc->peer.i.num_inbound_streams = 2385 ntohs(peer_init->init_hdr.num_inbound_streams); 2386 asoc->peer.i.initial_tsn = 2387 ntohl(peer_init->init_hdr.initial_tsn); 2388 2389 asoc->strreset_inseq = asoc->peer.i.initial_tsn; 2390 2391 /* Apply the upper bounds for output streams based on peer's 2392 * number of inbound streams. 2393 */ 2394 if (asoc->c.sinit_num_ostreams > 2395 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2396 asoc->c.sinit_num_ostreams = 2397 ntohs(peer_init->init_hdr.num_inbound_streams); 2398 } 2399 2400 if (asoc->c.sinit_max_instreams > 2401 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2402 asoc->c.sinit_max_instreams = 2403 ntohs(peer_init->init_hdr.num_outbound_streams); 2404 } 2405 2406 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2407 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2408 2409 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2410 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2411 2412 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2413 * high (for example, implementations MAY use the size of the receiver 2414 * advertised window). 2415 */ 2416 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2417 transports) { 2418 transport->ssthresh = asoc->peer.i.a_rwnd; 2419 } 2420 2421 /* Set up the TSN tracking pieces. */ 2422 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2423 asoc->peer.i.initial_tsn, gfp)) 2424 goto clean_up; 2425 2426 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2427 * 2428 * The stream sequence number in all the streams shall start 2429 * from 0 when the association is established. Also, when the 2430 * stream sequence number reaches the value 65535 the next 2431 * stream sequence number shall be set to 0. 2432 */ 2433 2434 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams, 2435 asoc->c.sinit_max_instreams, gfp)) 2436 goto clean_up; 2437 2438 /* Update frag_point when stream_interleave may get changed. */ 2439 sctp_assoc_update_frag_point(asoc); 2440 2441 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp)) 2442 goto clean_up; 2443 2444 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2445 * 2446 * When an endpoint has an ASCONF signaled change to be sent to the 2447 * remote endpoint it should do the following: 2448 * ... 2449 * A2) A serial number should be assigned to the Chunk. The serial 2450 * number should be a monotonically increasing number. All serial 2451 * numbers are defined to be initialized at the start of the 2452 * association to the same value as the Initial TSN. 2453 */ 2454 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2455 return 1; 2456 2457 clean_up: 2458 /* Release the transport structures. */ 2459 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2460 transport = list_entry(pos, struct sctp_transport, transports); 2461 if (transport->state != SCTP_ACTIVE) 2462 sctp_assoc_rm_peer(asoc, transport); 2463 } 2464 2465 nomem: 2466 return 0; 2467 } 2468 2469 2470 /* Update asoc with the option described in param. 2471 * 2472 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2473 * 2474 * asoc is the association to update. 2475 * param is the variable length parameter to use for update. 2476 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2477 * If the current packet is an INIT we want to minimize the amount of 2478 * work we do. In particular, we should not build transport 2479 * structures for the addresses. 2480 */ 2481 static int sctp_process_param(struct sctp_association *asoc, 2482 union sctp_params param, 2483 const union sctp_addr *peer_addr, 2484 gfp_t gfp) 2485 { 2486 struct sctp_endpoint *ep = asoc->ep; 2487 union sctp_addr_param *addr_param; 2488 struct net *net = asoc->base.net; 2489 struct sctp_transport *t; 2490 enum sctp_scope scope; 2491 union sctp_addr addr; 2492 struct sctp_af *af; 2493 int retval = 1, i; 2494 u32 stale; 2495 __u16 sat; 2496 2497 /* We maintain all INIT parameters in network byte order all the 2498 * time. This allows us to not worry about whether the parameters 2499 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2500 */ 2501 switch (param.p->type) { 2502 case SCTP_PARAM_IPV6_ADDRESS: 2503 if (PF_INET6 != asoc->base.sk->sk_family) 2504 break; 2505 goto do_addr_param; 2506 2507 case SCTP_PARAM_IPV4_ADDRESS: 2508 /* v4 addresses are not allowed on v6-only socket */ 2509 if (ipv6_only_sock(asoc->base.sk)) 2510 break; 2511 do_addr_param: 2512 af = sctp_get_af_specific(param_type2af(param.p->type)); 2513 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); 2514 scope = sctp_scope(peer_addr); 2515 if (sctp_in_scope(net, &addr, scope)) 2516 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2517 return 0; 2518 break; 2519 2520 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2521 if (!net->sctp.cookie_preserve_enable) 2522 break; 2523 2524 stale = ntohl(param.life->lifespan_increment); 2525 2526 /* Suggested Cookie Life span increment's unit is msec, 2527 * (1/1000sec). 2528 */ 2529 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale); 2530 break; 2531 2532 case SCTP_PARAM_HOST_NAME_ADDRESS: 2533 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__); 2534 break; 2535 2536 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2537 /* Turn off the default values first so we'll know which 2538 * ones are really set by the peer. 2539 */ 2540 asoc->peer.ipv4_address = 0; 2541 asoc->peer.ipv6_address = 0; 2542 2543 /* Assume that peer supports the address family 2544 * by which it sends a packet. 2545 */ 2546 if (peer_addr->sa.sa_family == AF_INET6) 2547 asoc->peer.ipv6_address = 1; 2548 else if (peer_addr->sa.sa_family == AF_INET) 2549 asoc->peer.ipv4_address = 1; 2550 2551 /* Cycle through address types; avoid divide by 0. */ 2552 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2553 if (sat) 2554 sat /= sizeof(__u16); 2555 2556 for (i = 0; i < sat; ++i) { 2557 switch (param.sat->types[i]) { 2558 case SCTP_PARAM_IPV4_ADDRESS: 2559 asoc->peer.ipv4_address = 1; 2560 break; 2561 2562 case SCTP_PARAM_IPV6_ADDRESS: 2563 if (PF_INET6 == asoc->base.sk->sk_family) 2564 asoc->peer.ipv6_address = 1; 2565 break; 2566 2567 case SCTP_PARAM_HOST_NAME_ADDRESS: 2568 asoc->peer.hostname_address = 1; 2569 break; 2570 2571 default: /* Just ignore anything else. */ 2572 break; 2573 } 2574 } 2575 break; 2576 2577 case SCTP_PARAM_STATE_COOKIE: 2578 asoc->peer.cookie_len = 2579 ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2580 kfree(asoc->peer.cookie); 2581 asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp); 2582 if (!asoc->peer.cookie) 2583 retval = 0; 2584 break; 2585 2586 case SCTP_PARAM_HEARTBEAT_INFO: 2587 /* Would be odd to receive, but it causes no problems. */ 2588 break; 2589 2590 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2591 /* Rejected during verify stage. */ 2592 break; 2593 2594 case SCTP_PARAM_ECN_CAPABLE: 2595 if (asoc->ep->ecn_enable) { 2596 asoc->peer.ecn_capable = 1; 2597 break; 2598 } 2599 /* Fall Through */ 2600 goto fall_through; 2601 2602 2603 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2604 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2605 break; 2606 2607 case SCTP_PARAM_SET_PRIMARY: 2608 if (!ep->asconf_enable) 2609 goto fall_through; 2610 2611 addr_param = param.v + sizeof(struct sctp_addip_param); 2612 2613 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 2614 if (af == NULL) 2615 break; 2616 2617 af->from_addr_param(&addr, addr_param, 2618 htons(asoc->peer.port), 0); 2619 2620 /* if the address is invalid, we can't process it. 2621 * XXX: see spec for what to do. 2622 */ 2623 if (!af->addr_valid(&addr, NULL, NULL)) 2624 break; 2625 2626 t = sctp_assoc_lookup_paddr(asoc, &addr); 2627 if (!t) 2628 break; 2629 2630 sctp_assoc_set_primary(asoc, t); 2631 break; 2632 2633 case SCTP_PARAM_SUPPORTED_EXT: 2634 sctp_process_ext_param(asoc, param); 2635 break; 2636 2637 case SCTP_PARAM_FWD_TSN_SUPPORT: 2638 if (asoc->ep->prsctp_enable) { 2639 asoc->peer.prsctp_capable = 1; 2640 break; 2641 } 2642 /* Fall Through */ 2643 goto fall_through; 2644 2645 case SCTP_PARAM_RANDOM: 2646 if (!ep->auth_enable) 2647 goto fall_through; 2648 2649 /* Save peer's random parameter */ 2650 kfree(asoc->peer.peer_random); 2651 asoc->peer.peer_random = kmemdup(param.p, 2652 ntohs(param.p->length), gfp); 2653 if (!asoc->peer.peer_random) { 2654 retval = 0; 2655 break; 2656 } 2657 break; 2658 2659 case SCTP_PARAM_HMAC_ALGO: 2660 if (!ep->auth_enable) 2661 goto fall_through; 2662 2663 /* Save peer's HMAC list */ 2664 kfree(asoc->peer.peer_hmacs); 2665 asoc->peer.peer_hmacs = kmemdup(param.p, 2666 ntohs(param.p->length), gfp); 2667 if (!asoc->peer.peer_hmacs) { 2668 retval = 0; 2669 break; 2670 } 2671 2672 /* Set the default HMAC the peer requested*/ 2673 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2674 break; 2675 2676 case SCTP_PARAM_CHUNKS: 2677 if (!ep->auth_enable) 2678 goto fall_through; 2679 2680 kfree(asoc->peer.peer_chunks); 2681 asoc->peer.peer_chunks = kmemdup(param.p, 2682 ntohs(param.p->length), gfp); 2683 if (!asoc->peer.peer_chunks) 2684 retval = 0; 2685 break; 2686 fall_through: 2687 default: 2688 /* Any unrecognized parameters should have been caught 2689 * and handled by sctp_verify_param() which should be 2690 * called prior to this routine. Simply log the error 2691 * here. 2692 */ 2693 pr_debug("%s: ignoring param:%d for association:%p.\n", 2694 __func__, ntohs(param.p->type), asoc); 2695 break; 2696 } 2697 2698 return retval; 2699 } 2700 2701 /* Select a new verification tag. */ 2702 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2703 { 2704 /* I believe that this random number generator complies with RFC1750. 2705 * A tag of 0 is reserved for special cases (e.g. INIT). 2706 */ 2707 __u32 x; 2708 2709 do { 2710 get_random_bytes(&x, sizeof(__u32)); 2711 } while (x == 0); 2712 2713 return x; 2714 } 2715 2716 /* Select an initial TSN to send during startup. */ 2717 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2718 { 2719 __u32 retval; 2720 2721 get_random_bytes(&retval, sizeof(__u32)); 2722 return retval; 2723 } 2724 2725 /* 2726 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2727 * 0 1 2 3 2728 * 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 2729 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2730 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2731 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2732 * | Serial Number | 2733 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2734 * | Address Parameter | 2735 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2736 * | ASCONF Parameter #1 | 2737 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2738 * \ \ 2739 * / .... / 2740 * \ \ 2741 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2742 * | ASCONF Parameter #N | 2743 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2744 * 2745 * Address Parameter and other parameter will not be wrapped in this function 2746 */ 2747 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2748 union sctp_addr *addr, 2749 int vparam_len) 2750 { 2751 struct sctp_addiphdr asconf; 2752 struct sctp_chunk *retval; 2753 int length = sizeof(asconf) + vparam_len; 2754 union sctp_addr_param addrparam; 2755 int addrlen; 2756 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2757 2758 addrlen = af->to_addr_param(addr, &addrparam); 2759 if (!addrlen) 2760 return NULL; 2761 length += addrlen; 2762 2763 /* Create the chunk. */ 2764 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length, 2765 GFP_ATOMIC); 2766 if (!retval) 2767 return NULL; 2768 2769 asconf.serial = htonl(asoc->addip_serial++); 2770 2771 retval->subh.addip_hdr = 2772 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2773 retval->param_hdr.v = 2774 sctp_addto_chunk(retval, addrlen, &addrparam); 2775 2776 return retval; 2777 } 2778 2779 /* ADDIP 2780 * 3.2.1 Add IP Address 2781 * 0 1 2 3 2782 * 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 2783 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2784 * | Type = 0xC001 | Length = Variable | 2785 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2786 * | ASCONF-Request Correlation ID | 2787 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2788 * | Address Parameter | 2789 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2790 * 2791 * 3.2.2 Delete IP Address 2792 * 0 1 2 3 2793 * 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 2794 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2795 * | Type = 0xC002 | Length = Variable | 2796 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2797 * | ASCONF-Request Correlation ID | 2798 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2799 * | Address Parameter | 2800 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2801 * 2802 */ 2803 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2804 union sctp_addr *laddr, 2805 struct sockaddr *addrs, 2806 int addrcnt, __be16 flags) 2807 { 2808 union sctp_addr_param addr_param; 2809 struct sctp_addip_param param; 2810 int paramlen = sizeof(param); 2811 struct sctp_chunk *retval; 2812 int addr_param_len = 0; 2813 union sctp_addr *addr; 2814 int totallen = 0, i; 2815 int del_pickup = 0; 2816 struct sctp_af *af; 2817 void *addr_buf; 2818 2819 /* Get total length of all the address parameters. */ 2820 addr_buf = addrs; 2821 for (i = 0; i < addrcnt; i++) { 2822 addr = addr_buf; 2823 af = sctp_get_af_specific(addr->v4.sin_family); 2824 addr_param_len = af->to_addr_param(addr, &addr_param); 2825 2826 totallen += paramlen; 2827 totallen += addr_param_len; 2828 2829 addr_buf += af->sockaddr_len; 2830 if (asoc->asconf_addr_del_pending && !del_pickup) { 2831 /* reuse the parameter length from the same scope one */ 2832 totallen += paramlen; 2833 totallen += addr_param_len; 2834 del_pickup = 1; 2835 2836 pr_debug("%s: picked same-scope del_pending addr, " 2837 "totallen for all addresses is %d\n", 2838 __func__, totallen); 2839 } 2840 } 2841 2842 /* Create an asconf chunk with the required length. */ 2843 retval = sctp_make_asconf(asoc, laddr, totallen); 2844 if (!retval) 2845 return NULL; 2846 2847 /* Add the address parameters to the asconf chunk. */ 2848 addr_buf = addrs; 2849 for (i = 0; i < addrcnt; i++) { 2850 addr = addr_buf; 2851 af = sctp_get_af_specific(addr->v4.sin_family); 2852 addr_param_len = af->to_addr_param(addr, &addr_param); 2853 param.param_hdr.type = flags; 2854 param.param_hdr.length = htons(paramlen + addr_param_len); 2855 param.crr_id = htonl(i); 2856 2857 sctp_addto_chunk(retval, paramlen, ¶m); 2858 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2859 2860 addr_buf += af->sockaddr_len; 2861 } 2862 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2863 addr = asoc->asconf_addr_del_pending; 2864 af = sctp_get_af_specific(addr->v4.sin_family); 2865 addr_param_len = af->to_addr_param(addr, &addr_param); 2866 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2867 param.param_hdr.length = htons(paramlen + addr_param_len); 2868 param.crr_id = htonl(i); 2869 2870 sctp_addto_chunk(retval, paramlen, ¶m); 2871 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2872 } 2873 return retval; 2874 } 2875 2876 /* ADDIP 2877 * 3.2.4 Set Primary IP Address 2878 * 0 1 2 3 2879 * 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 2880 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2881 * | Type =0xC004 | Length = Variable | 2882 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2883 * | ASCONF-Request Correlation ID | 2884 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2885 * | Address Parameter | 2886 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2887 * 2888 * Create an ASCONF chunk with Set Primary IP address parameter. 2889 */ 2890 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2891 union sctp_addr *addr) 2892 { 2893 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2894 union sctp_addr_param addrparam; 2895 struct sctp_addip_param param; 2896 struct sctp_chunk *retval; 2897 int len = sizeof(param); 2898 int addrlen; 2899 2900 addrlen = af->to_addr_param(addr, &addrparam); 2901 if (!addrlen) 2902 return NULL; 2903 len += addrlen; 2904 2905 /* Create the chunk and make asconf header. */ 2906 retval = sctp_make_asconf(asoc, addr, len); 2907 if (!retval) 2908 return NULL; 2909 2910 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2911 param.param_hdr.length = htons(len); 2912 param.crr_id = 0; 2913 2914 sctp_addto_chunk(retval, sizeof(param), ¶m); 2915 sctp_addto_chunk(retval, addrlen, &addrparam); 2916 2917 return retval; 2918 } 2919 2920 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2921 * 0 1 2 3 2922 * 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 2923 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2924 * | Type = 0x80 | Chunk Flags | Chunk Length | 2925 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2926 * | Serial Number | 2927 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2928 * | ASCONF Parameter Response#1 | 2929 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2930 * \ \ 2931 * / .... / 2932 * \ \ 2933 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2934 * | ASCONF Parameter Response#N | 2935 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2936 * 2937 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2938 */ 2939 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2940 __u32 serial, int vparam_len) 2941 { 2942 struct sctp_addiphdr asconf; 2943 struct sctp_chunk *retval; 2944 int length = sizeof(asconf) + vparam_len; 2945 2946 /* Create the chunk. */ 2947 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length, 2948 GFP_ATOMIC); 2949 if (!retval) 2950 return NULL; 2951 2952 asconf.serial = htonl(serial); 2953 2954 retval->subh.addip_hdr = 2955 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2956 2957 return retval; 2958 } 2959 2960 /* Add response parameters to an ASCONF_ACK chunk. */ 2961 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2962 __be16 err_code, 2963 struct sctp_addip_param *asconf_param) 2964 { 2965 struct sctp_addip_param ack_param; 2966 struct sctp_errhdr err_param; 2967 int asconf_param_len = 0; 2968 int err_param_len = 0; 2969 __be16 response_type; 2970 2971 if (SCTP_ERROR_NO_ERROR == err_code) { 2972 response_type = SCTP_PARAM_SUCCESS_REPORT; 2973 } else { 2974 response_type = SCTP_PARAM_ERR_CAUSE; 2975 err_param_len = sizeof(err_param); 2976 if (asconf_param) 2977 asconf_param_len = 2978 ntohs(asconf_param->param_hdr.length); 2979 } 2980 2981 /* Add Success Indication or Error Cause Indication parameter. */ 2982 ack_param.param_hdr.type = response_type; 2983 ack_param.param_hdr.length = htons(sizeof(ack_param) + 2984 err_param_len + 2985 asconf_param_len); 2986 ack_param.crr_id = crr_id; 2987 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 2988 2989 if (SCTP_ERROR_NO_ERROR == err_code) 2990 return; 2991 2992 /* Add Error Cause parameter. */ 2993 err_param.cause = err_code; 2994 err_param.length = htons(err_param_len + asconf_param_len); 2995 sctp_addto_chunk(chunk, err_param_len, &err_param); 2996 2997 /* Add the failed TLV copied from ASCONF chunk. */ 2998 if (asconf_param) 2999 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 3000 } 3001 3002 /* Process a asconf parameter. */ 3003 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 3004 struct sctp_chunk *asconf, 3005 struct sctp_addip_param *asconf_param) 3006 { 3007 union sctp_addr_param *addr_param; 3008 struct sctp_transport *peer; 3009 union sctp_addr addr; 3010 struct sctp_af *af; 3011 3012 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3013 3014 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 3015 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 3016 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 3017 return SCTP_ERROR_UNKNOWN_PARAM; 3018 3019 switch (addr_param->p.type) { 3020 case SCTP_PARAM_IPV6_ADDRESS: 3021 if (!asoc->peer.ipv6_address) 3022 return SCTP_ERROR_DNS_FAILED; 3023 break; 3024 case SCTP_PARAM_IPV4_ADDRESS: 3025 if (!asoc->peer.ipv4_address) 3026 return SCTP_ERROR_DNS_FAILED; 3027 break; 3028 default: 3029 return SCTP_ERROR_DNS_FAILED; 3030 } 3031 3032 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3033 if (unlikely(!af)) 3034 return SCTP_ERROR_DNS_FAILED; 3035 3036 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); 3037 3038 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3039 * or multicast address. 3040 * (note: wildcard is permitted and requires special handling so 3041 * make sure we check for that) 3042 */ 3043 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3044 return SCTP_ERROR_DNS_FAILED; 3045 3046 switch (asconf_param->param_hdr.type) { 3047 case SCTP_PARAM_ADD_IP: 3048 /* Section 4.2.1: 3049 * If the address 0.0.0.0 or ::0 is provided, the source 3050 * address of the packet MUST be added. 3051 */ 3052 if (af->is_any(&addr)) 3053 memcpy(&addr, &asconf->source, sizeof(addr)); 3054 3055 if (security_sctp_bind_connect(asoc->ep->base.sk, 3056 SCTP_PARAM_ADD_IP, 3057 (struct sockaddr *)&addr, 3058 af->sockaddr_len)) 3059 return SCTP_ERROR_REQ_REFUSED; 3060 3061 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3062 * request and does not have the local resources to add this 3063 * new address to the association, it MUST return an Error 3064 * Cause TLV set to the new error code 'Operation Refused 3065 * Due to Resource Shortage'. 3066 */ 3067 3068 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3069 if (!peer) 3070 return SCTP_ERROR_RSRC_LOW; 3071 3072 /* Start the heartbeat timer. */ 3073 sctp_transport_reset_hb_timer(peer); 3074 asoc->new_transport = peer; 3075 break; 3076 case SCTP_PARAM_DEL_IP: 3077 /* ADDIP 4.3 D7) If a request is received to delete the 3078 * last remaining IP address of a peer endpoint, the receiver 3079 * MUST send an Error Cause TLV with the error cause set to the 3080 * new error code 'Request to Delete Last Remaining IP Address'. 3081 */ 3082 if (asoc->peer.transport_count == 1) 3083 return SCTP_ERROR_DEL_LAST_IP; 3084 3085 /* ADDIP 4.3 D8) If a request is received to delete an IP 3086 * address which is also the source address of the IP packet 3087 * which contained the ASCONF chunk, the receiver MUST reject 3088 * this request. To reject the request the receiver MUST send 3089 * an Error Cause TLV set to the new error code 'Request to 3090 * Delete Source IP Address' 3091 */ 3092 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3093 return SCTP_ERROR_DEL_SRC_IP; 3094 3095 /* Section 4.2.2 3096 * If the address 0.0.0.0 or ::0 is provided, all 3097 * addresses of the peer except the source address of the 3098 * packet MUST be deleted. 3099 */ 3100 if (af->is_any(&addr)) { 3101 sctp_assoc_set_primary(asoc, asconf->transport); 3102 sctp_assoc_del_nonprimary_peers(asoc, 3103 asconf->transport); 3104 return SCTP_ERROR_NO_ERROR; 3105 } 3106 3107 /* If the address is not part of the association, the 3108 * ASCONF-ACK with Error Cause Indication Parameter 3109 * which including cause of Unresolvable Address should 3110 * be sent. 3111 */ 3112 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3113 if (!peer) 3114 return SCTP_ERROR_DNS_FAILED; 3115 3116 sctp_assoc_rm_peer(asoc, peer); 3117 break; 3118 case SCTP_PARAM_SET_PRIMARY: 3119 /* ADDIP Section 4.2.4 3120 * If the address 0.0.0.0 or ::0 is provided, the receiver 3121 * MAY mark the source address of the packet as its 3122 * primary. 3123 */ 3124 if (af->is_any(&addr)) 3125 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr)); 3126 3127 if (security_sctp_bind_connect(asoc->ep->base.sk, 3128 SCTP_PARAM_SET_PRIMARY, 3129 (struct sockaddr *)&addr, 3130 af->sockaddr_len)) 3131 return SCTP_ERROR_REQ_REFUSED; 3132 3133 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3134 if (!peer) 3135 return SCTP_ERROR_DNS_FAILED; 3136 3137 sctp_assoc_set_primary(asoc, peer); 3138 break; 3139 } 3140 3141 return SCTP_ERROR_NO_ERROR; 3142 } 3143 3144 /* Verify the ASCONF packet before we process it. */ 3145 bool sctp_verify_asconf(const struct sctp_association *asoc, 3146 struct sctp_chunk *chunk, bool addr_param_needed, 3147 struct sctp_paramhdr **errp) 3148 { 3149 struct sctp_addip_chunk *addip; 3150 bool addr_param_seen = false; 3151 union sctp_params param; 3152 3153 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr; 3154 sctp_walk_params(param, addip, addip_hdr.params) { 3155 size_t length = ntohs(param.p->length); 3156 3157 *errp = param.p; 3158 switch (param.p->type) { 3159 case SCTP_PARAM_ERR_CAUSE: 3160 break; 3161 case SCTP_PARAM_IPV4_ADDRESS: 3162 if (length != sizeof(struct sctp_ipv4addr_param)) 3163 return false; 3164 /* ensure there is only one addr param and it's in the 3165 * beginning of addip_hdr params, or we reject it. 3166 */ 3167 if (param.v != addip->addip_hdr.params) 3168 return false; 3169 addr_param_seen = true; 3170 break; 3171 case SCTP_PARAM_IPV6_ADDRESS: 3172 if (length != sizeof(struct sctp_ipv6addr_param)) 3173 return false; 3174 if (param.v != addip->addip_hdr.params) 3175 return false; 3176 addr_param_seen = true; 3177 break; 3178 case SCTP_PARAM_ADD_IP: 3179 case SCTP_PARAM_DEL_IP: 3180 case SCTP_PARAM_SET_PRIMARY: 3181 /* In ASCONF chunks, these need to be first. */ 3182 if (addr_param_needed && !addr_param_seen) 3183 return false; 3184 length = ntohs(param.addip->param_hdr.length); 3185 if (length < sizeof(struct sctp_addip_param) + 3186 sizeof(**errp)) 3187 return false; 3188 break; 3189 case SCTP_PARAM_SUCCESS_REPORT: 3190 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3191 if (length != sizeof(struct sctp_addip_param)) 3192 return false; 3193 break; 3194 default: 3195 /* This is unkown to us, reject! */ 3196 return false; 3197 } 3198 } 3199 3200 /* Remaining sanity checks. */ 3201 if (addr_param_needed && !addr_param_seen) 3202 return false; 3203 if (!addr_param_needed && addr_param_seen) 3204 return false; 3205 if (param.v != chunk->chunk_end) 3206 return false; 3207 3208 return true; 3209 } 3210 3211 /* Process an incoming ASCONF chunk with the next expected serial no. and 3212 * return an ASCONF_ACK chunk to be sent in response. 3213 */ 3214 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3215 struct sctp_chunk *asconf) 3216 { 3217 union sctp_addr_param *addr_param; 3218 struct sctp_addip_chunk *addip; 3219 struct sctp_chunk *asconf_ack; 3220 bool all_param_pass = true; 3221 struct sctp_addiphdr *hdr; 3222 int length = 0, chunk_len; 3223 union sctp_params param; 3224 __be16 err_code; 3225 __u32 serial; 3226 3227 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr; 3228 chunk_len = ntohs(asconf->chunk_hdr->length) - 3229 sizeof(struct sctp_chunkhdr); 3230 hdr = (struct sctp_addiphdr *)asconf->skb->data; 3231 serial = ntohl(hdr->serial); 3232 3233 /* Skip the addiphdr and store a pointer to address parameter. */ 3234 length = sizeof(*hdr); 3235 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3236 chunk_len -= length; 3237 3238 /* Skip the address parameter and store a pointer to the first 3239 * asconf parameter. 3240 */ 3241 length = ntohs(addr_param->p.length); 3242 chunk_len -= length; 3243 3244 /* create an ASCONF_ACK chunk. 3245 * Based on the definitions of parameters, we know that the size of 3246 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3247 * parameters. 3248 */ 3249 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3250 if (!asconf_ack) 3251 goto done; 3252 3253 /* Process the TLVs contained within the ASCONF chunk. */ 3254 sctp_walk_params(param, addip, addip_hdr.params) { 3255 /* Skip preceeding address parameters. */ 3256 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 3257 param.p->type == SCTP_PARAM_IPV6_ADDRESS) 3258 continue; 3259 3260 err_code = sctp_process_asconf_param(asoc, asconf, 3261 param.addip); 3262 /* ADDIP 4.1 A7) 3263 * If an error response is received for a TLV parameter, 3264 * all TLVs with no response before the failed TLV are 3265 * considered successful if not reported. All TLVs after 3266 * the failed response are considered unsuccessful unless 3267 * a specific success indication is present for the parameter. 3268 */ 3269 if (err_code != SCTP_ERROR_NO_ERROR) 3270 all_param_pass = false; 3271 if (!all_param_pass) 3272 sctp_add_asconf_response(asconf_ack, param.addip->crr_id, 3273 err_code, param.addip); 3274 3275 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3276 * an IP address sends an 'Out of Resource' in its response, it 3277 * MUST also fail any subsequent add or delete requests bundled 3278 * in the ASCONF. 3279 */ 3280 if (err_code == SCTP_ERROR_RSRC_LOW) 3281 goto done; 3282 } 3283 done: 3284 asoc->peer.addip_serial++; 3285 3286 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3287 * after freeing the reference to old asconf ack if any. 3288 */ 3289 if (asconf_ack) { 3290 sctp_chunk_hold(asconf_ack); 3291 list_add_tail(&asconf_ack->transmitted_list, 3292 &asoc->asconf_ack_list); 3293 } 3294 3295 return asconf_ack; 3296 } 3297 3298 /* Process a asconf parameter that is successfully acked. */ 3299 static void sctp_asconf_param_success(struct sctp_association *asoc, 3300 struct sctp_addip_param *asconf_param) 3301 { 3302 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3303 union sctp_addr_param *addr_param; 3304 struct sctp_sockaddr_entry *saddr; 3305 struct sctp_transport *transport; 3306 union sctp_addr addr; 3307 struct sctp_af *af; 3308 3309 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3310 3311 /* We have checked the packet before, so we do not check again. */ 3312 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3313 af->from_addr_param(&addr, addr_param, htons(bp->port), 0); 3314 3315 switch (asconf_param->param_hdr.type) { 3316 case SCTP_PARAM_ADD_IP: 3317 /* This is always done in BH context with a socket lock 3318 * held, so the list can not change. 3319 */ 3320 local_bh_disable(); 3321 list_for_each_entry(saddr, &bp->address_list, list) { 3322 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3323 saddr->state = SCTP_ADDR_SRC; 3324 } 3325 local_bh_enable(); 3326 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3327 transports) { 3328 sctp_transport_dst_release(transport); 3329 } 3330 break; 3331 case SCTP_PARAM_DEL_IP: 3332 local_bh_disable(); 3333 sctp_del_bind_addr(bp, &addr); 3334 if (asoc->asconf_addr_del_pending != NULL && 3335 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3336 kfree(asoc->asconf_addr_del_pending); 3337 asoc->asconf_addr_del_pending = NULL; 3338 } 3339 local_bh_enable(); 3340 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3341 transports) { 3342 sctp_transport_dst_release(transport); 3343 } 3344 break; 3345 default: 3346 break; 3347 } 3348 } 3349 3350 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3351 * for the given asconf parameter. If there is no response for this parameter, 3352 * return the error code based on the third argument 'no_err'. 3353 * ADDIP 4.1 3354 * A7) If an error response is received for a TLV parameter, all TLVs with no 3355 * response before the failed TLV are considered successful if not reported. 3356 * All TLVs after the failed response are considered unsuccessful unless a 3357 * specific success indication is present for the parameter. 3358 */ 3359 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3360 struct sctp_addip_param *asconf_param, 3361 int no_err) 3362 { 3363 struct sctp_addip_param *asconf_ack_param; 3364 struct sctp_errhdr *err_param; 3365 int asconf_ack_len; 3366 __be16 err_code; 3367 int length; 3368 3369 if (no_err) 3370 err_code = SCTP_ERROR_NO_ERROR; 3371 else 3372 err_code = SCTP_ERROR_REQ_REFUSED; 3373 3374 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3375 sizeof(struct sctp_chunkhdr); 3376 3377 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3378 * the first asconf_ack parameter. 3379 */ 3380 length = sizeof(struct sctp_addiphdr); 3381 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data + 3382 length); 3383 asconf_ack_len -= length; 3384 3385 while (asconf_ack_len > 0) { 3386 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3387 switch (asconf_ack_param->param_hdr.type) { 3388 case SCTP_PARAM_SUCCESS_REPORT: 3389 return SCTP_ERROR_NO_ERROR; 3390 case SCTP_PARAM_ERR_CAUSE: 3391 length = sizeof(*asconf_ack_param); 3392 err_param = (void *)asconf_ack_param + length; 3393 asconf_ack_len -= length; 3394 if (asconf_ack_len > 0) 3395 return err_param->cause; 3396 else 3397 return SCTP_ERROR_INV_PARAM; 3398 break; 3399 default: 3400 return SCTP_ERROR_INV_PARAM; 3401 } 3402 } 3403 3404 length = ntohs(asconf_ack_param->param_hdr.length); 3405 asconf_ack_param = (void *)asconf_ack_param + length; 3406 asconf_ack_len -= length; 3407 } 3408 3409 return err_code; 3410 } 3411 3412 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3413 int sctp_process_asconf_ack(struct sctp_association *asoc, 3414 struct sctp_chunk *asconf_ack) 3415 { 3416 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3417 struct sctp_addip_param *asconf_param; 3418 __be16 err_code = SCTP_ERROR_NO_ERROR; 3419 union sctp_addr_param *addr_param; 3420 int asconf_len = asconf->skb->len; 3421 int all_param_pass = 0; 3422 int length = 0; 3423 int no_err = 1; 3424 int retval = 0; 3425 3426 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3427 * a pointer to address parameter. 3428 */ 3429 length = sizeof(struct sctp_addip_chunk); 3430 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3431 asconf_len -= length; 3432 3433 /* Skip the address parameter in the last asconf sent and store a 3434 * pointer to the first asconf parameter. 3435 */ 3436 length = ntohs(addr_param->p.length); 3437 asconf_param = (void *)addr_param + length; 3438 asconf_len -= length; 3439 3440 /* ADDIP 4.1 3441 * A8) If there is no response(s) to specific TLV parameter(s), and no 3442 * failures are indicated, then all request(s) are considered 3443 * successful. 3444 */ 3445 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr)) 3446 all_param_pass = 1; 3447 3448 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3449 while (asconf_len > 0) { 3450 if (all_param_pass) 3451 err_code = SCTP_ERROR_NO_ERROR; 3452 else { 3453 err_code = sctp_get_asconf_response(asconf_ack, 3454 asconf_param, 3455 no_err); 3456 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3457 no_err = 0; 3458 } 3459 3460 switch (err_code) { 3461 case SCTP_ERROR_NO_ERROR: 3462 sctp_asconf_param_success(asoc, asconf_param); 3463 break; 3464 3465 case SCTP_ERROR_RSRC_LOW: 3466 retval = 1; 3467 break; 3468 3469 case SCTP_ERROR_UNKNOWN_PARAM: 3470 /* Disable sending this type of asconf parameter in 3471 * future. 3472 */ 3473 asoc->peer.addip_disabled_mask |= 3474 asconf_param->param_hdr.type; 3475 break; 3476 3477 case SCTP_ERROR_REQ_REFUSED: 3478 case SCTP_ERROR_DEL_LAST_IP: 3479 case SCTP_ERROR_DEL_SRC_IP: 3480 default: 3481 break; 3482 } 3483 3484 /* Skip the processed asconf parameter and move to the next 3485 * one. 3486 */ 3487 length = ntohs(asconf_param->param_hdr.length); 3488 asconf_param = (void *)asconf_param + length; 3489 asconf_len -= length; 3490 } 3491 3492 if (no_err && asoc->src_out_of_asoc_ok) { 3493 asoc->src_out_of_asoc_ok = 0; 3494 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3495 } 3496 3497 /* Free the cached last sent asconf chunk. */ 3498 list_del_init(&asconf->transmitted_list); 3499 sctp_chunk_free(asconf); 3500 asoc->addip_last_asconf = NULL; 3501 3502 return retval; 3503 } 3504 3505 /* Make a FWD TSN chunk. */ 3506 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3507 __u32 new_cum_tsn, size_t nstreams, 3508 struct sctp_fwdtsn_skip *skiplist) 3509 { 3510 struct sctp_chunk *retval = NULL; 3511 struct sctp_fwdtsn_hdr ftsn_hdr; 3512 struct sctp_fwdtsn_skip skip; 3513 size_t hint; 3514 int i; 3515 3516 hint = (nstreams + 1) * sizeof(__u32); 3517 3518 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC); 3519 3520 if (!retval) 3521 return NULL; 3522 3523 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3524 retval->subh.fwdtsn_hdr = 3525 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3526 3527 for (i = 0; i < nstreams; i++) { 3528 skip.stream = skiplist[i].stream; 3529 skip.ssn = skiplist[i].ssn; 3530 sctp_addto_chunk(retval, sizeof(skip), &skip); 3531 } 3532 3533 return retval; 3534 } 3535 3536 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc, 3537 __u32 new_cum_tsn, size_t nstreams, 3538 struct sctp_ifwdtsn_skip *skiplist) 3539 { 3540 struct sctp_chunk *retval = NULL; 3541 struct sctp_ifwdtsn_hdr ftsn_hdr; 3542 size_t hint; 3543 3544 hint = (nstreams + 1) * sizeof(__u32); 3545 3546 retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint, 3547 GFP_ATOMIC); 3548 if (!retval) 3549 return NULL; 3550 3551 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3552 retval->subh.ifwdtsn_hdr = 3553 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3554 3555 sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist); 3556 3557 return retval; 3558 } 3559 3560 /* RE-CONFIG 3.1 (RE-CONFIG chunk) 3561 * 0 1 2 3 3562 * 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 3563 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3564 * | Type = 130 | Chunk Flags | Chunk Length | 3565 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3566 * \ \ 3567 * / Re-configuration Parameter / 3568 * \ \ 3569 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3570 * \ \ 3571 * / Re-configuration Parameter (optional) / 3572 * \ \ 3573 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3574 */ 3575 static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc, 3576 int length) 3577 { 3578 struct sctp_reconf_chunk *reconf; 3579 struct sctp_chunk *retval; 3580 3581 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length, 3582 GFP_ATOMIC); 3583 if (!retval) 3584 return NULL; 3585 3586 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr; 3587 retval->param_hdr.v = reconf->params; 3588 3589 return retval; 3590 } 3591 3592 /* RE-CONFIG 4.1 (STREAM OUT RESET) 3593 * 0 1 2 3 3594 * 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 3595 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3596 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N | 3597 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3598 * | Re-configuration Request Sequence Number | 3599 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3600 * | Re-configuration Response Sequence Number | 3601 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3602 * | Sender's Last Assigned TSN | 3603 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3604 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3605 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3606 * / ...... / 3607 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3608 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3609 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3610 * 3611 * RE-CONFIG 4.2 (STREAM IN RESET) 3612 * 0 1 2 3 3613 * 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 3614 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3615 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N | 3616 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3617 * | Re-configuration Request Sequence Number | 3618 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3619 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3620 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3621 * / ...... / 3622 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3623 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3624 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3625 */ 3626 struct sctp_chunk *sctp_make_strreset_req( 3627 const struct sctp_association *asoc, 3628 __u16 stream_num, __be16 *stream_list, 3629 bool out, bool in) 3630 { 3631 __u16 stream_len = stream_num * sizeof(__u16); 3632 struct sctp_strreset_outreq outreq; 3633 struct sctp_strreset_inreq inreq; 3634 struct sctp_chunk *retval; 3635 __u16 outlen, inlen; 3636 3637 outlen = (sizeof(outreq) + stream_len) * out; 3638 inlen = (sizeof(inreq) + stream_len) * in; 3639 3640 retval = sctp_make_reconf(asoc, outlen + inlen); 3641 if (!retval) 3642 return NULL; 3643 3644 if (outlen) { 3645 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST; 3646 outreq.param_hdr.length = htons(outlen); 3647 outreq.request_seq = htonl(asoc->strreset_outseq); 3648 outreq.response_seq = htonl(asoc->strreset_inseq - 1); 3649 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1); 3650 3651 sctp_addto_chunk(retval, sizeof(outreq), &outreq); 3652 3653 if (stream_len) 3654 sctp_addto_chunk(retval, stream_len, stream_list); 3655 } 3656 3657 if (inlen) { 3658 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST; 3659 inreq.param_hdr.length = htons(inlen); 3660 inreq.request_seq = htonl(asoc->strreset_outseq + out); 3661 3662 sctp_addto_chunk(retval, sizeof(inreq), &inreq); 3663 3664 if (stream_len) 3665 sctp_addto_chunk(retval, stream_len, stream_list); 3666 } 3667 3668 return retval; 3669 } 3670 3671 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL) 3672 * 0 1 2 3 3673 * 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 3674 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3675 * | Parameter Type = 15 | Parameter Length = 8 | 3676 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3677 * | Re-configuration Request Sequence Number | 3678 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3679 */ 3680 struct sctp_chunk *sctp_make_strreset_tsnreq( 3681 const struct sctp_association *asoc) 3682 { 3683 struct sctp_strreset_tsnreq tsnreq; 3684 __u16 length = sizeof(tsnreq); 3685 struct sctp_chunk *retval; 3686 3687 retval = sctp_make_reconf(asoc, length); 3688 if (!retval) 3689 return NULL; 3690 3691 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST; 3692 tsnreq.param_hdr.length = htons(length); 3693 tsnreq.request_seq = htonl(asoc->strreset_outseq); 3694 3695 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq); 3696 3697 return retval; 3698 } 3699 3700 /* RE-CONFIG 4.5/4.6 (ADD STREAM) 3701 * 0 1 2 3 3702 * 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 3703 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3704 * | Parameter Type = 17 | Parameter Length = 12 | 3705 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3706 * | Re-configuration Request Sequence Number | 3707 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3708 * | Number of new streams | Reserved | 3709 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3710 */ 3711 struct sctp_chunk *sctp_make_strreset_addstrm( 3712 const struct sctp_association *asoc, 3713 __u16 out, __u16 in) 3714 { 3715 struct sctp_strreset_addstrm addstrm; 3716 __u16 size = sizeof(addstrm); 3717 struct sctp_chunk *retval; 3718 3719 retval = sctp_make_reconf(asoc, (!!out + !!in) * size); 3720 if (!retval) 3721 return NULL; 3722 3723 if (out) { 3724 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS; 3725 addstrm.param_hdr.length = htons(size); 3726 addstrm.number_of_streams = htons(out); 3727 addstrm.request_seq = htonl(asoc->strreset_outseq); 3728 addstrm.reserved = 0; 3729 3730 sctp_addto_chunk(retval, size, &addstrm); 3731 } 3732 3733 if (in) { 3734 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS; 3735 addstrm.param_hdr.length = htons(size); 3736 addstrm.number_of_streams = htons(in); 3737 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out); 3738 addstrm.reserved = 0; 3739 3740 sctp_addto_chunk(retval, size, &addstrm); 3741 } 3742 3743 return retval; 3744 } 3745 3746 /* RE-CONFIG 4.4 (RESP) 3747 * 0 1 2 3 3748 * 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 3749 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3750 * | Parameter Type = 16 | Parameter Length | 3751 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3752 * | Re-configuration Response Sequence Number | 3753 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3754 * | Result | 3755 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3756 */ 3757 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc, 3758 __u32 result, __u32 sn) 3759 { 3760 struct sctp_strreset_resp resp; 3761 __u16 length = sizeof(resp); 3762 struct sctp_chunk *retval; 3763 3764 retval = sctp_make_reconf(asoc, length); 3765 if (!retval) 3766 return NULL; 3767 3768 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3769 resp.param_hdr.length = htons(length); 3770 resp.response_seq = htonl(sn); 3771 resp.result = htonl(result); 3772 3773 sctp_addto_chunk(retval, sizeof(resp), &resp); 3774 3775 return retval; 3776 } 3777 3778 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP) 3779 * 0 1 2 3 3780 * 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 3781 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3782 * | Parameter Type = 16 | Parameter Length | 3783 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3784 * | Re-configuration Response Sequence Number | 3785 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3786 * | Result | 3787 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3788 * | Sender's Next TSN (optional) | 3789 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3790 * | Receiver's Next TSN (optional) | 3791 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3792 */ 3793 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc, 3794 __u32 result, __u32 sn, 3795 __u32 sender_tsn, 3796 __u32 receiver_tsn) 3797 { 3798 struct sctp_strreset_resptsn tsnresp; 3799 __u16 length = sizeof(tsnresp); 3800 struct sctp_chunk *retval; 3801 3802 retval = sctp_make_reconf(asoc, length); 3803 if (!retval) 3804 return NULL; 3805 3806 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3807 tsnresp.param_hdr.length = htons(length); 3808 3809 tsnresp.response_seq = htonl(sn); 3810 tsnresp.result = htonl(result); 3811 tsnresp.senders_next_tsn = htonl(sender_tsn); 3812 tsnresp.receivers_next_tsn = htonl(receiver_tsn); 3813 3814 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp); 3815 3816 return retval; 3817 } 3818 3819 bool sctp_verify_reconf(const struct sctp_association *asoc, 3820 struct sctp_chunk *chunk, 3821 struct sctp_paramhdr **errp) 3822 { 3823 struct sctp_reconf_chunk *hdr; 3824 union sctp_params param; 3825 __be16 last = 0; 3826 __u16 cnt = 0; 3827 3828 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; 3829 sctp_walk_params(param, hdr, params) { 3830 __u16 length = ntohs(param.p->length); 3831 3832 *errp = param.p; 3833 if (cnt++ > 2) 3834 return false; 3835 switch (param.p->type) { 3836 case SCTP_PARAM_RESET_OUT_REQUEST: 3837 if (length < sizeof(struct sctp_strreset_outreq) || 3838 (last && last != SCTP_PARAM_RESET_RESPONSE && 3839 last != SCTP_PARAM_RESET_IN_REQUEST)) 3840 return false; 3841 break; 3842 case SCTP_PARAM_RESET_IN_REQUEST: 3843 if (length < sizeof(struct sctp_strreset_inreq) || 3844 (last && last != SCTP_PARAM_RESET_OUT_REQUEST)) 3845 return false; 3846 break; 3847 case SCTP_PARAM_RESET_RESPONSE: 3848 if ((length != sizeof(struct sctp_strreset_resp) && 3849 length != sizeof(struct sctp_strreset_resptsn)) || 3850 (last && last != SCTP_PARAM_RESET_RESPONSE && 3851 last != SCTP_PARAM_RESET_OUT_REQUEST)) 3852 return false; 3853 break; 3854 case SCTP_PARAM_RESET_TSN_REQUEST: 3855 if (length != 3856 sizeof(struct sctp_strreset_tsnreq) || last) 3857 return false; 3858 break; 3859 case SCTP_PARAM_RESET_ADD_IN_STREAMS: 3860 if (length != sizeof(struct sctp_strreset_addstrm) || 3861 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS)) 3862 return false; 3863 break; 3864 case SCTP_PARAM_RESET_ADD_OUT_STREAMS: 3865 if (length != sizeof(struct sctp_strreset_addstrm) || 3866 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS)) 3867 return false; 3868 break; 3869 default: 3870 return false; 3871 } 3872 3873 last = param.p->type; 3874 } 3875 3876 return true; 3877 } 3878