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 if (chunk && chunk->asoc) 862 ctsn = sctp_tsnmap_get_ctsn(&chunk->asoc->peer.tsn_map); 863 else 864 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 865 866 shut.cum_tsn_ack = htonl(ctsn); 867 868 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0, 869 sizeof(shut), GFP_ATOMIC); 870 if (!retval) 871 goto nodata; 872 873 retval->subh.shutdown_hdr = 874 sctp_addto_chunk(retval, sizeof(shut), &shut); 875 876 if (chunk) 877 retval->transport = chunk->transport; 878 nodata: 879 return retval; 880 } 881 882 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 883 const struct sctp_chunk *chunk) 884 { 885 struct sctp_chunk *retval; 886 887 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0, 888 GFP_ATOMIC); 889 890 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 891 * 892 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 893 * HEARTBEAT ACK, * etc.) to the same destination transport 894 * address from which it * received the DATA or control chunk 895 * to which it is replying. 896 * 897 * [ACK back to where the SHUTDOWN came from.] 898 */ 899 if (retval && chunk) 900 retval->transport = chunk->transport; 901 902 return retval; 903 } 904 905 struct sctp_chunk *sctp_make_shutdown_complete( 906 const struct sctp_association *asoc, 907 const struct sctp_chunk *chunk) 908 { 909 struct sctp_chunk *retval; 910 __u8 flags = 0; 911 912 /* Set the T-bit if we have no association (vtag will be 913 * reflected) 914 */ 915 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; 916 917 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 918 0, GFP_ATOMIC); 919 920 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 921 * 922 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 923 * HEARTBEAT ACK, * etc.) to the same destination transport 924 * address from which it * received the DATA or control chunk 925 * to which it is replying. 926 * 927 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK 928 * came from.] 929 */ 930 if (retval && chunk) 931 retval->transport = chunk->transport; 932 933 return retval; 934 } 935 936 /* Create an ABORT. Note that we set the T bit if we have no 937 * association, except when responding to an INIT (sctpimpguide 2.41). 938 */ 939 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 940 const struct sctp_chunk *chunk, 941 const size_t hint) 942 { 943 struct sctp_chunk *retval; 944 __u8 flags = 0; 945 946 /* Set the T-bit if we have no association and 'chunk' is not 947 * an INIT (vtag will be reflected). 948 */ 949 if (!asoc) { 950 if (chunk && chunk->chunk_hdr && 951 chunk->chunk_hdr->type == SCTP_CID_INIT) 952 flags = 0; 953 else 954 flags = SCTP_CHUNK_FLAG_T; 955 } 956 957 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint, 958 GFP_ATOMIC); 959 960 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 961 * 962 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 963 * HEARTBEAT ACK, * etc.) to the same destination transport 964 * address from which it * received the DATA or control chunk 965 * to which it is replying. 966 * 967 * [ABORT back to where the offender came from.] 968 */ 969 if (retval && chunk) 970 retval->transport = chunk->transport; 971 972 return retval; 973 } 974 975 /* Helper to create ABORT with a NO_USER_DATA error. */ 976 struct sctp_chunk *sctp_make_abort_no_data( 977 const struct sctp_association *asoc, 978 const struct sctp_chunk *chunk, 979 __u32 tsn) 980 { 981 struct sctp_chunk *retval; 982 __be32 payload; 983 984 retval = sctp_make_abort(asoc, chunk, 985 sizeof(struct sctp_errhdr) + sizeof(tsn)); 986 987 if (!retval) 988 goto no_mem; 989 990 /* Put the tsn back into network byte order. */ 991 payload = htonl(tsn); 992 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload)); 993 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload); 994 995 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 996 * 997 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 998 * HEARTBEAT ACK, * etc.) to the same destination transport 999 * address from which it * received the DATA or control chunk 1000 * to which it is replying. 1001 * 1002 * [ABORT back to where the offender came from.] 1003 */ 1004 if (chunk) 1005 retval->transport = chunk->transport; 1006 1007 no_mem: 1008 return retval; 1009 } 1010 1011 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ 1012 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 1013 struct msghdr *msg, 1014 size_t paylen) 1015 { 1016 struct sctp_chunk *retval; 1017 void *payload = NULL; 1018 int err; 1019 1020 retval = sctp_make_abort(asoc, NULL, 1021 sizeof(struct sctp_errhdr) + paylen); 1022 if (!retval) 1023 goto err_chunk; 1024 1025 if (paylen) { 1026 /* Put the msg_iov together into payload. */ 1027 payload = kmalloc(paylen, GFP_KERNEL); 1028 if (!payload) 1029 goto err_payload; 1030 1031 err = memcpy_from_msg(payload, msg, paylen); 1032 if (err < 0) 1033 goto err_copy; 1034 } 1035 1036 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); 1037 sctp_addto_chunk(retval, paylen, payload); 1038 1039 if (paylen) 1040 kfree(payload); 1041 1042 return retval; 1043 1044 err_copy: 1045 kfree(payload); 1046 err_payload: 1047 sctp_chunk_free(retval); 1048 retval = NULL; 1049 err_chunk: 1050 return retval; 1051 } 1052 1053 /* Append bytes to the end of a parameter. Will panic if chunk is not big 1054 * enough. 1055 */ 1056 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 1057 const void *data) 1058 { 1059 int chunklen = ntohs(chunk->chunk_hdr->length); 1060 void *target; 1061 1062 target = skb_put(chunk->skb, len); 1063 1064 if (data) 1065 memcpy(target, data, len); 1066 else 1067 memset(target, 0, len); 1068 1069 /* Adjust the chunk length field. */ 1070 chunk->chunk_hdr->length = htons(chunklen + len); 1071 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1072 1073 return target; 1074 } 1075 1076 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ 1077 struct sctp_chunk *sctp_make_abort_violation( 1078 const struct sctp_association *asoc, 1079 const struct sctp_chunk *chunk, 1080 const __u8 *payload, 1081 const size_t paylen) 1082 { 1083 struct sctp_chunk *retval; 1084 struct sctp_paramhdr phdr; 1085 1086 retval = sctp_make_abort(asoc, chunk, sizeof(struct sctp_errhdr) + 1087 paylen + sizeof(phdr)); 1088 if (!retval) 1089 goto end; 1090 1091 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen + 1092 sizeof(phdr)); 1093 1094 phdr.type = htons(chunk->chunk_hdr->type); 1095 phdr.length = chunk->chunk_hdr->length; 1096 sctp_addto_chunk(retval, paylen, payload); 1097 sctp_addto_param(retval, sizeof(phdr), &phdr); 1098 1099 end: 1100 return retval; 1101 } 1102 1103 struct sctp_chunk *sctp_make_violation_paramlen( 1104 const struct sctp_association *asoc, 1105 const struct sctp_chunk *chunk, 1106 struct sctp_paramhdr *param) 1107 { 1108 static const char error[] = "The following parameter had invalid length:"; 1109 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr) + 1110 sizeof(*param); 1111 struct sctp_chunk *retval; 1112 1113 retval = sctp_make_abort(asoc, chunk, payload_len); 1114 if (!retval) 1115 goto nodata; 1116 1117 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, 1118 sizeof(error) + sizeof(*param)); 1119 sctp_addto_chunk(retval, sizeof(error), error); 1120 sctp_addto_param(retval, sizeof(*param), param); 1121 1122 nodata: 1123 return retval; 1124 } 1125 1126 struct sctp_chunk *sctp_make_violation_max_retrans( 1127 const struct sctp_association *asoc, 1128 const struct sctp_chunk *chunk) 1129 { 1130 static const char error[] = "Association exceeded its max_retrans count"; 1131 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr); 1132 struct sctp_chunk *retval; 1133 1134 retval = sctp_make_abort(asoc, chunk, payload_len); 1135 if (!retval) 1136 goto nodata; 1137 1138 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error)); 1139 sctp_addto_chunk(retval, sizeof(error), error); 1140 1141 nodata: 1142 return retval; 1143 } 1144 1145 /* Make a HEARTBEAT chunk. */ 1146 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1147 const struct sctp_transport *transport) 1148 { 1149 struct sctp_sender_hb_info hbinfo; 1150 struct sctp_chunk *retval; 1151 1152 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, 1153 sizeof(hbinfo), GFP_ATOMIC); 1154 1155 if (!retval) 1156 goto nodata; 1157 1158 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; 1159 hbinfo.param_hdr.length = htons(sizeof(hbinfo)); 1160 hbinfo.daddr = transport->ipaddr; 1161 hbinfo.sent_at = jiffies; 1162 hbinfo.hb_nonce = transport->hb_nonce; 1163 1164 /* Cast away the 'const', as this is just telling the chunk 1165 * what transport it belongs to. 1166 */ 1167 retval->transport = (struct sctp_transport *) transport; 1168 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo), 1169 &hbinfo); 1170 1171 nodata: 1172 return retval; 1173 } 1174 1175 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1176 const struct sctp_chunk *chunk, 1177 const void *payload, 1178 const size_t paylen) 1179 { 1180 struct sctp_chunk *retval; 1181 1182 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen, 1183 GFP_ATOMIC); 1184 if (!retval) 1185 goto nodata; 1186 1187 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1188 1189 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1190 * 1191 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1192 * HEARTBEAT ACK, * etc.) to the same destination transport 1193 * address from which it * received the DATA or control chunk 1194 * to which it is replying. 1195 * 1196 * [HBACK back to where the HEARTBEAT came from.] 1197 */ 1198 if (chunk) 1199 retval->transport = chunk->transport; 1200 1201 nodata: 1202 return retval; 1203 } 1204 1205 /* Create an Operation Error chunk with the specified space reserved. 1206 * This routine can be used for containing multiple causes in the chunk. 1207 */ 1208 static struct sctp_chunk *sctp_make_op_error_space( 1209 const struct sctp_association *asoc, 1210 const struct sctp_chunk *chunk, 1211 size_t size) 1212 { 1213 struct sctp_chunk *retval; 1214 1215 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0, 1216 sizeof(struct sctp_errhdr) + size, 1217 GFP_ATOMIC); 1218 if (!retval) 1219 goto nodata; 1220 1221 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1222 * 1223 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1224 * HEARTBEAT ACK, etc.) to the same destination transport 1225 * address from which it received the DATA or control chunk 1226 * to which it is replying. 1227 * 1228 */ 1229 if (chunk) 1230 retval->transport = chunk->transport; 1231 1232 nodata: 1233 return retval; 1234 } 1235 1236 /* Create an Operation Error chunk of a fixed size, specifically, 1237 * min(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) - overheads. 1238 * This is a helper function to allocate an error chunk for those 1239 * invalid parameter codes in which we may not want to report all the 1240 * errors, if the incoming chunk is large. If it can't fit in a single 1241 * packet, we ignore it. 1242 */ 1243 static inline struct sctp_chunk *sctp_make_op_error_limited( 1244 const struct sctp_association *asoc, 1245 const struct sctp_chunk *chunk) 1246 { 1247 size_t size = SCTP_DEFAULT_MAXSEGMENT; 1248 struct sctp_sock *sp = NULL; 1249 1250 if (asoc) { 1251 size = min_t(size_t, size, asoc->pathmtu); 1252 sp = sctp_sk(asoc->base.sk); 1253 } 1254 1255 size = sctp_mtu_payload(sp, size, sizeof(struct sctp_errhdr)); 1256 1257 return sctp_make_op_error_space(asoc, chunk, size); 1258 } 1259 1260 /* Create an Operation Error chunk. */ 1261 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1262 const struct sctp_chunk *chunk, 1263 __be16 cause_code, const void *payload, 1264 size_t paylen, size_t reserve_tail) 1265 { 1266 struct sctp_chunk *retval; 1267 1268 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); 1269 if (!retval) 1270 goto nodata; 1271 1272 sctp_init_cause(retval, cause_code, paylen + reserve_tail); 1273 sctp_addto_chunk(retval, paylen, payload); 1274 if (reserve_tail) 1275 sctp_addto_param(retval, reserve_tail, NULL); 1276 1277 nodata: 1278 return retval; 1279 } 1280 1281 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc, 1282 __u16 key_id) 1283 { 1284 struct sctp_authhdr auth_hdr; 1285 struct sctp_hmac *hmac_desc; 1286 struct sctp_chunk *retval; 1287 1288 /* Get the first hmac that the peer told us to use */ 1289 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1290 if (unlikely(!hmac_desc)) 1291 return NULL; 1292 1293 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0, 1294 hmac_desc->hmac_len + sizeof(auth_hdr), 1295 GFP_ATOMIC); 1296 if (!retval) 1297 return NULL; 1298 1299 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1300 auth_hdr.shkey_id = htons(key_id); 1301 1302 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr), 1303 &auth_hdr); 1304 1305 skb_put_zero(retval->skb, hmac_desc->hmac_len); 1306 1307 /* Adjust the chunk header to include the empty MAC */ 1308 retval->chunk_hdr->length = 1309 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1310 retval->chunk_end = skb_tail_pointer(retval->skb); 1311 1312 return retval; 1313 } 1314 1315 1316 /******************************************************************** 1317 * 2nd Level Abstractions 1318 ********************************************************************/ 1319 1320 /* Turn an skb into a chunk. 1321 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1322 * 1323 * sctpimpguide-05.txt Section 2.8.2 1324 * M1) Each time a new DATA chunk is transmitted 1325 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1326 * 'TSN.Missing.Report' count will be used to determine missing chunks 1327 * and when to fast retransmit. 1328 * 1329 */ 1330 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1331 const struct sctp_association *asoc, 1332 struct sock *sk, gfp_t gfp) 1333 { 1334 struct sctp_chunk *retval; 1335 1336 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp); 1337 1338 if (!retval) 1339 goto nodata; 1340 if (!sk) 1341 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb); 1342 1343 INIT_LIST_HEAD(&retval->list); 1344 retval->skb = skb; 1345 retval->asoc = (struct sctp_association *)asoc; 1346 retval->singleton = 1; 1347 1348 retval->fast_retransmit = SCTP_CAN_FRTX; 1349 1350 /* Polish the bead hole. */ 1351 INIT_LIST_HEAD(&retval->transmitted_list); 1352 INIT_LIST_HEAD(&retval->frag_list); 1353 SCTP_DBG_OBJCNT_INC(chunk); 1354 refcount_set(&retval->refcnt, 1); 1355 1356 nodata: 1357 return retval; 1358 } 1359 1360 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1361 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1362 union sctp_addr *dest) 1363 { 1364 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1365 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1366 } 1367 1368 /* Extract the source address from a chunk. */ 1369 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1370 { 1371 /* If we have a known transport, use that. */ 1372 if (chunk->transport) { 1373 return &chunk->transport->ipaddr; 1374 } else { 1375 /* Otherwise, extract it from the IP header. */ 1376 return &chunk->source; 1377 } 1378 } 1379 1380 /* Create a new chunk, setting the type and flags headers from the 1381 * arguments, reserving enough space for a 'paylen' byte payload. 1382 */ 1383 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 1384 __u8 type, __u8 flags, int paylen, 1385 gfp_t gfp) 1386 { 1387 struct sctp_chunkhdr *chunk_hdr; 1388 struct sctp_chunk *retval; 1389 struct sk_buff *skb; 1390 struct sock *sk; 1391 int chunklen; 1392 1393 chunklen = SCTP_PAD4(sizeof(*chunk_hdr) + paylen); 1394 if (chunklen > SCTP_MAX_CHUNK_LEN) 1395 goto nodata; 1396 1397 /* No need to allocate LL here, as this is only a chunk. */ 1398 skb = alloc_skb(chunklen, gfp); 1399 if (!skb) 1400 goto nodata; 1401 1402 /* Make room for the chunk header. */ 1403 chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr)); 1404 chunk_hdr->type = type; 1405 chunk_hdr->flags = flags; 1406 chunk_hdr->length = htons(sizeof(*chunk_hdr)); 1407 1408 sk = asoc ? asoc->base.sk : NULL; 1409 retval = sctp_chunkify(skb, asoc, sk, gfp); 1410 if (!retval) { 1411 kfree_skb(skb); 1412 goto nodata; 1413 } 1414 1415 retval->chunk_hdr = chunk_hdr; 1416 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr); 1417 1418 /* Determine if the chunk needs to be authenticated */ 1419 if (sctp_auth_send_cid(type, asoc)) 1420 retval->auth = 1; 1421 1422 return retval; 1423 nodata: 1424 return NULL; 1425 } 1426 1427 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 1428 __u8 flags, int paylen, gfp_t gfp) 1429 { 1430 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp); 1431 } 1432 1433 struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc, 1434 __u8 flags, int paylen, gfp_t gfp) 1435 { 1436 return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp); 1437 } 1438 1439 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 1440 __u8 type, __u8 flags, int paylen, 1441 gfp_t gfp) 1442 { 1443 struct sctp_chunk *chunk; 1444 1445 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp); 1446 if (chunk) 1447 sctp_control_set_owner_w(chunk); 1448 1449 return chunk; 1450 } 1451 1452 /* Release the memory occupied by a chunk. */ 1453 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1454 { 1455 BUG_ON(!list_empty(&chunk->list)); 1456 list_del_init(&chunk->transmitted_list); 1457 1458 consume_skb(chunk->skb); 1459 consume_skb(chunk->auth_chunk); 1460 1461 SCTP_DBG_OBJCNT_DEC(chunk); 1462 kmem_cache_free(sctp_chunk_cachep, chunk); 1463 } 1464 1465 /* Possibly, free the chunk. */ 1466 void sctp_chunk_free(struct sctp_chunk *chunk) 1467 { 1468 /* Release our reference on the message tracker. */ 1469 if (chunk->msg) 1470 sctp_datamsg_put(chunk->msg); 1471 1472 sctp_chunk_put(chunk); 1473 } 1474 1475 /* Grab a reference to the chunk. */ 1476 void sctp_chunk_hold(struct sctp_chunk *ch) 1477 { 1478 refcount_inc(&ch->refcnt); 1479 } 1480 1481 /* Release a reference to the chunk. */ 1482 void sctp_chunk_put(struct sctp_chunk *ch) 1483 { 1484 if (refcount_dec_and_test(&ch->refcnt)) 1485 sctp_chunk_destroy(ch); 1486 } 1487 1488 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1489 * enough. 1490 */ 1491 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1492 { 1493 int chunklen = ntohs(chunk->chunk_hdr->length); 1494 int padlen = SCTP_PAD4(chunklen) - chunklen; 1495 void *target; 1496 1497 skb_put_zero(chunk->skb, padlen); 1498 target = skb_put_data(chunk->skb, data, len); 1499 1500 /* Adjust the chunk length field. */ 1501 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1502 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1503 1504 return target; 1505 } 1506 1507 /* Append bytes from user space to the end of a chunk. Will panic if 1508 * chunk is not big enough. 1509 * Returns a kernel err value. 1510 */ 1511 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len, 1512 struct iov_iter *from) 1513 { 1514 void *target; 1515 1516 /* Make room in chunk for data. */ 1517 target = skb_put(chunk->skb, len); 1518 1519 /* Copy data (whole iovec) into chunk */ 1520 if (!copy_from_iter_full(target, len, from)) 1521 return -EFAULT; 1522 1523 /* Adjust the chunk length field. */ 1524 chunk->chunk_hdr->length = 1525 htons(ntohs(chunk->chunk_hdr->length) + len); 1526 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1527 1528 return 0; 1529 } 1530 1531 /* Helper function to assign a TSN if needed. This assumes that both 1532 * the data_hdr and association have already been assigned. 1533 */ 1534 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1535 { 1536 struct sctp_stream *stream; 1537 struct sctp_chunk *lchunk; 1538 struct sctp_datamsg *msg; 1539 __u16 ssn, sid; 1540 1541 if (chunk->has_ssn) 1542 return; 1543 1544 /* All fragments will be on the same stream */ 1545 sid = ntohs(chunk->subh.data_hdr->stream); 1546 stream = &chunk->asoc->stream; 1547 1548 /* Now assign the sequence number to the entire message. 1549 * All fragments must have the same stream sequence number. 1550 */ 1551 msg = chunk->msg; 1552 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1553 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1554 ssn = 0; 1555 } else { 1556 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1557 ssn = sctp_ssn_next(stream, out, sid); 1558 else 1559 ssn = sctp_ssn_peek(stream, out, sid); 1560 } 1561 1562 lchunk->subh.data_hdr->ssn = htons(ssn); 1563 lchunk->has_ssn = 1; 1564 } 1565 } 1566 1567 /* Helper function to assign a TSN if needed. This assumes that both 1568 * the data_hdr and association have already been assigned. 1569 */ 1570 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1571 { 1572 if (!chunk->has_tsn) { 1573 /* This is the last possible instant to 1574 * assign a TSN. 1575 */ 1576 chunk->subh.data_hdr->tsn = 1577 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1578 chunk->has_tsn = 1; 1579 } 1580 } 1581 1582 /* Create a CLOSED association to use with an incoming packet. */ 1583 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1584 struct sctp_chunk *chunk, 1585 gfp_t gfp) 1586 { 1587 struct sctp_association *asoc; 1588 enum sctp_scope scope; 1589 struct sk_buff *skb; 1590 1591 /* Create the bare association. */ 1592 scope = sctp_scope(sctp_source(chunk)); 1593 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1594 if (!asoc) 1595 goto nodata; 1596 asoc->temp = 1; 1597 skb = chunk->skb; 1598 /* Create an entry for the source address of the packet. */ 1599 SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1); 1600 1601 nodata: 1602 return asoc; 1603 } 1604 1605 /* Build a cookie representing asoc. 1606 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1607 */ 1608 static struct sctp_cookie_param *sctp_pack_cookie( 1609 const struct sctp_endpoint *ep, 1610 const struct sctp_association *asoc, 1611 const struct sctp_chunk *init_chunk, 1612 int *cookie_len, const __u8 *raw_addrs, 1613 int addrs_len) 1614 { 1615 struct sctp_signed_cookie *cookie; 1616 struct sctp_cookie_param *retval; 1617 int headersize, bodysize; 1618 1619 /* Header size is static data prior to the actual cookie, including 1620 * any padding. 1621 */ 1622 headersize = sizeof(struct sctp_paramhdr) + 1623 (sizeof(struct sctp_signed_cookie) - 1624 sizeof(struct sctp_cookie)); 1625 bodysize = sizeof(struct sctp_cookie) 1626 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1627 1628 /* Pad out the cookie to a multiple to make the signature 1629 * functions simpler to write. 1630 */ 1631 if (bodysize % SCTP_COOKIE_MULTIPLE) 1632 bodysize += SCTP_COOKIE_MULTIPLE 1633 - (bodysize % SCTP_COOKIE_MULTIPLE); 1634 *cookie_len = headersize + bodysize; 1635 1636 /* Clear this memory since we are sending this data structure 1637 * out on the network. 1638 */ 1639 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1640 if (!retval) 1641 goto nodata; 1642 1643 cookie = (struct sctp_signed_cookie *) retval->body; 1644 1645 /* Set up the parameter header. */ 1646 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1647 retval->p.length = htons(*cookie_len); 1648 1649 /* Copy the cookie part of the association itself. */ 1650 cookie->c = asoc->c; 1651 /* Save the raw address list length in the cookie. */ 1652 cookie->c.raw_addr_list_len = addrs_len; 1653 1654 /* Remember PR-SCTP capability. */ 1655 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1656 1657 /* Save adaptation indication in the cookie. */ 1658 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1659 1660 /* Set an expiration time for the cookie. */ 1661 cookie->c.expiration = ktime_add(asoc->cookie_life, 1662 ktime_get_real()); 1663 1664 /* Copy the peer's init packet. */ 1665 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr, 1666 ntohs(init_chunk->chunk_hdr->length)); 1667 1668 /* Copy the raw local address list of the association. */ 1669 memcpy((__u8 *)&cookie->c.peer_init[0] + 1670 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1671 1672 if (sctp_sk(ep->base.sk)->hmac) { 1673 struct crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac; 1674 int err; 1675 1676 /* Sign the message. */ 1677 err = crypto_shash_setkey(tfm, ep->secret_key, 1678 sizeof(ep->secret_key)) ?: 1679 crypto_shash_tfm_digest(tfm, (u8 *)&cookie->c, bodysize, 1680 cookie->signature); 1681 if (err) 1682 goto free_cookie; 1683 } 1684 1685 return retval; 1686 1687 free_cookie: 1688 kfree(retval); 1689 nodata: 1690 *cookie_len = 0; 1691 return NULL; 1692 } 1693 1694 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1695 struct sctp_association *sctp_unpack_cookie( 1696 const struct sctp_endpoint *ep, 1697 const struct sctp_association *asoc, 1698 struct sctp_chunk *chunk, gfp_t gfp, 1699 int *error, struct sctp_chunk **errp) 1700 { 1701 struct sctp_association *retval = NULL; 1702 int headersize, bodysize, fixed_size; 1703 struct sctp_signed_cookie *cookie; 1704 struct sk_buff *skb = chunk->skb; 1705 struct sctp_cookie *bear_cookie; 1706 __u8 *digest = ep->digest; 1707 enum sctp_scope scope; 1708 unsigned int len; 1709 ktime_t kt; 1710 1711 /* Header size is static data prior to the actual cookie, including 1712 * any padding. 1713 */ 1714 headersize = sizeof(struct sctp_chunkhdr) + 1715 (sizeof(struct sctp_signed_cookie) - 1716 sizeof(struct sctp_cookie)); 1717 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1718 fixed_size = headersize + sizeof(struct sctp_cookie); 1719 1720 /* Verify that the chunk looks like it even has a cookie. 1721 * There must be enough room for our cookie and our peer's 1722 * INIT chunk. 1723 */ 1724 len = ntohs(chunk->chunk_hdr->length); 1725 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1726 goto malformed; 1727 1728 /* Verify that the cookie has been padded out. */ 1729 if (bodysize % SCTP_COOKIE_MULTIPLE) 1730 goto malformed; 1731 1732 /* Process the cookie. */ 1733 cookie = chunk->subh.cookie_hdr; 1734 bear_cookie = &cookie->c; 1735 1736 if (!sctp_sk(ep->base.sk)->hmac) 1737 goto no_hmac; 1738 1739 /* Check the signature. */ 1740 { 1741 struct crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac; 1742 int err; 1743 1744 err = crypto_shash_setkey(tfm, ep->secret_key, 1745 sizeof(ep->secret_key)) ?: 1746 crypto_shash_tfm_digest(tfm, (u8 *)bear_cookie, bodysize, 1747 digest); 1748 if (err) { 1749 *error = -SCTP_IERROR_NOMEM; 1750 goto fail; 1751 } 1752 } 1753 1754 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1755 *error = -SCTP_IERROR_BAD_SIG; 1756 goto fail; 1757 } 1758 1759 no_hmac: 1760 /* IG Section 2.35.2: 1761 * 3) Compare the port numbers and the verification tag contained 1762 * within the COOKIE ECHO chunk to the actual port numbers and the 1763 * verification tag within the SCTP common header of the received 1764 * packet. If these values do not match the packet MUST be silently 1765 * discarded, 1766 */ 1767 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1768 *error = -SCTP_IERROR_BAD_TAG; 1769 goto fail; 1770 } 1771 1772 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1773 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1774 *error = -SCTP_IERROR_BAD_PORTS; 1775 goto fail; 1776 } 1777 1778 /* Check to see if the cookie is stale. If there is already 1779 * an association, there is no need to check cookie's expiration 1780 * for init collision case of lost COOKIE ACK. 1781 * If skb has been timestamped, then use the stamp, otherwise 1782 * use current time. This introduces a small possibility that 1783 * a cookie may be considered expired, but this would only slow 1784 * down the new association establishment instead of every packet. 1785 */ 1786 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1787 kt = skb_get_ktime(skb); 1788 else 1789 kt = ktime_get_real(); 1790 1791 if (!asoc && ktime_before(bear_cookie->expiration, kt)) { 1792 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); 1793 __be32 n = htonl(usecs); 1794 1795 /* 1796 * Section 3.3.10.3 Stale Cookie Error (3) 1797 * 1798 * Cause of error 1799 * --------------- 1800 * Stale Cookie Error: Indicates the receipt of a valid State 1801 * Cookie that has expired. 1802 */ 1803 *errp = sctp_make_op_error(asoc, chunk, 1804 SCTP_ERROR_STALE_COOKIE, &n, 1805 sizeof(n), 0); 1806 if (*errp) 1807 *error = -SCTP_IERROR_STALE_COOKIE; 1808 else 1809 *error = -SCTP_IERROR_NOMEM; 1810 1811 goto fail; 1812 } 1813 1814 /* Make a new base association. */ 1815 scope = sctp_scope(sctp_source(chunk)); 1816 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1817 if (!retval) { 1818 *error = -SCTP_IERROR_NOMEM; 1819 goto fail; 1820 } 1821 1822 /* Set up our peer's port number. */ 1823 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1824 1825 /* Populate the association from the cookie. */ 1826 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1827 1828 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1829 GFP_ATOMIC) < 0) { 1830 *error = -SCTP_IERROR_NOMEM; 1831 goto fail; 1832 } 1833 1834 /* Also, add the destination address. */ 1835 if (list_empty(&retval->base.bind_addr.address_list)) { 1836 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1837 sizeof(chunk->dest), SCTP_ADDR_SRC, 1838 GFP_ATOMIC); 1839 } 1840 1841 retval->next_tsn = retval->c.initial_tsn; 1842 retval->ctsn_ack_point = retval->next_tsn - 1; 1843 retval->addip_serial = retval->c.initial_tsn; 1844 retval->strreset_outseq = retval->c.initial_tsn; 1845 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1846 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1847 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1848 1849 /* The INIT stuff will be done by the side effects. */ 1850 return retval; 1851 1852 fail: 1853 if (retval) 1854 sctp_association_free(retval); 1855 1856 return NULL; 1857 1858 malformed: 1859 /* Yikes! The packet is either corrupt or deliberately 1860 * malformed. 1861 */ 1862 *error = -SCTP_IERROR_MALFORMED; 1863 goto fail; 1864 } 1865 1866 /******************************************************************** 1867 * 3rd Level Abstractions 1868 ********************************************************************/ 1869 1870 struct __sctp_missing { 1871 __be32 num_missing; 1872 __be16 type; 1873 } __packed; 1874 1875 /* 1876 * Report a missing mandatory parameter. 1877 */ 1878 static int sctp_process_missing_param(const struct sctp_association *asoc, 1879 enum sctp_param paramtype, 1880 struct sctp_chunk *chunk, 1881 struct sctp_chunk **errp) 1882 { 1883 struct __sctp_missing report; 1884 __u16 len; 1885 1886 len = SCTP_PAD4(sizeof(report)); 1887 1888 /* Make an ERROR chunk, preparing enough room for 1889 * returning multiple unknown parameters. 1890 */ 1891 if (!*errp) 1892 *errp = sctp_make_op_error_space(asoc, chunk, len); 1893 1894 if (*errp) { 1895 report.num_missing = htonl(1); 1896 report.type = paramtype; 1897 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1898 sizeof(report)); 1899 sctp_addto_chunk(*errp, sizeof(report), &report); 1900 } 1901 1902 /* Stop processing this chunk. */ 1903 return 0; 1904 } 1905 1906 /* Report an Invalid Mandatory Parameter. */ 1907 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1908 struct sctp_chunk *chunk, 1909 struct sctp_chunk **errp) 1910 { 1911 /* Invalid Mandatory Parameter Error has no payload. */ 1912 1913 if (!*errp) 1914 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1915 1916 if (*errp) 1917 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1918 1919 /* Stop processing this chunk. */ 1920 return 0; 1921 } 1922 1923 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1924 struct sctp_paramhdr *param, 1925 const struct sctp_chunk *chunk, 1926 struct sctp_chunk **errp) 1927 { 1928 /* This is a fatal error. Any accumulated non-fatal errors are 1929 * not reported. 1930 */ 1931 if (*errp) 1932 sctp_chunk_free(*errp); 1933 1934 /* Create an error chunk and fill it in with our payload. */ 1935 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1936 1937 return 0; 1938 } 1939 1940 1941 /* Do not attempt to handle the HOST_NAME parm. However, do 1942 * send back an indicator to the peer. 1943 */ 1944 static int sctp_process_hn_param(const struct sctp_association *asoc, 1945 union sctp_params param, 1946 struct sctp_chunk *chunk, 1947 struct sctp_chunk **errp) 1948 { 1949 __u16 len = ntohs(param.p->length); 1950 1951 /* Processing of the HOST_NAME parameter will generate an 1952 * ABORT. If we've accumulated any non-fatal errors, they 1953 * would be unrecognized parameters and we should not include 1954 * them in the ABORT. 1955 */ 1956 if (*errp) 1957 sctp_chunk_free(*errp); 1958 1959 *errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_DNS_FAILED, 1960 param.v, len, 0); 1961 1962 /* Stop processing this chunk. */ 1963 return 0; 1964 } 1965 1966 static int sctp_verify_ext_param(struct net *net, 1967 const struct sctp_endpoint *ep, 1968 union sctp_params param) 1969 { 1970 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 1971 int have_asconf = 0; 1972 int have_auth = 0; 1973 int i; 1974 1975 for (i = 0; i < num_ext; i++) { 1976 switch (param.ext->chunks[i]) { 1977 case SCTP_CID_AUTH: 1978 have_auth = 1; 1979 break; 1980 case SCTP_CID_ASCONF: 1981 case SCTP_CID_ASCONF_ACK: 1982 have_asconf = 1; 1983 break; 1984 } 1985 } 1986 1987 /* ADD-IP Security: The draft requires us to ABORT or ignore the 1988 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 1989 * only if ADD-IP is turned on and we are not backward-compatible 1990 * mode. 1991 */ 1992 if (net->sctp.addip_noauth) 1993 return 1; 1994 1995 if (ep->asconf_enable && !have_auth && have_asconf) 1996 return 0; 1997 1998 return 1; 1999 } 2000 2001 static void sctp_process_ext_param(struct sctp_association *asoc, 2002 union sctp_params param) 2003 { 2004 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2005 int i; 2006 2007 for (i = 0; i < num_ext; i++) { 2008 switch (param.ext->chunks[i]) { 2009 case SCTP_CID_RECONF: 2010 if (asoc->ep->reconf_enable) 2011 asoc->peer.reconf_capable = 1; 2012 break; 2013 case SCTP_CID_FWD_TSN: 2014 if (asoc->ep->prsctp_enable) 2015 asoc->peer.prsctp_capable = 1; 2016 break; 2017 case SCTP_CID_AUTH: 2018 /* if the peer reports AUTH, assume that he 2019 * supports AUTH. 2020 */ 2021 if (asoc->ep->auth_enable) 2022 asoc->peer.auth_capable = 1; 2023 break; 2024 case SCTP_CID_ASCONF: 2025 case SCTP_CID_ASCONF_ACK: 2026 if (asoc->ep->asconf_enable) 2027 asoc->peer.asconf_capable = 1; 2028 break; 2029 case SCTP_CID_I_DATA: 2030 if (asoc->ep->intl_enable) 2031 asoc->peer.intl_capable = 1; 2032 break; 2033 default: 2034 break; 2035 } 2036 } 2037 } 2038 2039 /* RFC 3.2.1 & the Implementers Guide 2.2. 2040 * 2041 * The Parameter Types are encoded such that the 2042 * highest-order two bits specify the action that must be 2043 * taken if the processing endpoint does not recognize the 2044 * Parameter Type. 2045 * 2046 * 00 - Stop processing this parameter; do not process any further 2047 * parameters within this chunk 2048 * 2049 * 01 - Stop processing this parameter, do not process any further 2050 * parameters within this chunk, and report the unrecognized 2051 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2052 * 2053 * 10 - Skip this parameter and continue processing. 2054 * 2055 * 11 - Skip this parameter and continue processing but 2056 * report the unrecognized parameter in an 2057 * 'Unrecognized Parameter' ERROR chunk. 2058 * 2059 * Return value: 2060 * SCTP_IERROR_NO_ERROR - continue with the chunk 2061 * SCTP_IERROR_ERROR - stop and report an error. 2062 * SCTP_IERROR_NOMEME - out of memory. 2063 */ 2064 static enum sctp_ierror sctp_process_unk_param( 2065 const struct sctp_association *asoc, 2066 union sctp_params param, 2067 struct sctp_chunk *chunk, 2068 struct sctp_chunk **errp) 2069 { 2070 int retval = SCTP_IERROR_NO_ERROR; 2071 2072 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2073 case SCTP_PARAM_ACTION_DISCARD: 2074 retval = SCTP_IERROR_ERROR; 2075 break; 2076 case SCTP_PARAM_ACTION_SKIP: 2077 break; 2078 case SCTP_PARAM_ACTION_DISCARD_ERR: 2079 retval = SCTP_IERROR_ERROR; 2080 /* Fall through */ 2081 case SCTP_PARAM_ACTION_SKIP_ERR: 2082 /* Make an ERROR chunk, preparing enough room for 2083 * returning multiple unknown parameters. 2084 */ 2085 if (!*errp) { 2086 *errp = sctp_make_op_error_limited(asoc, chunk); 2087 if (!*errp) { 2088 /* If there is no memory for generating the 2089 * ERROR report as specified, an ABORT will be 2090 * triggered to the peer and the association 2091 * won't be established. 2092 */ 2093 retval = SCTP_IERROR_NOMEM; 2094 break; 2095 } 2096 } 2097 2098 if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2099 ntohs(param.p->length))) 2100 sctp_addto_chunk(*errp, ntohs(param.p->length), 2101 param.v); 2102 break; 2103 default: 2104 break; 2105 } 2106 2107 return retval; 2108 } 2109 2110 /* Verify variable length parameters 2111 * Return values: 2112 * SCTP_IERROR_ABORT - trigger an ABORT 2113 * SCTP_IERROR_NOMEM - out of memory (abort) 2114 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2115 * SCTP_IERROR_NO_ERROR - continue with the chunk 2116 */ 2117 static enum sctp_ierror sctp_verify_param(struct net *net, 2118 const struct sctp_endpoint *ep, 2119 const struct sctp_association *asoc, 2120 union sctp_params param, 2121 enum sctp_cid cid, 2122 struct sctp_chunk *chunk, 2123 struct sctp_chunk **err_chunk) 2124 { 2125 struct sctp_hmac_algo_param *hmacs; 2126 int retval = SCTP_IERROR_NO_ERROR; 2127 __u16 n_elt, id = 0; 2128 int i; 2129 2130 /* FIXME - This routine is not looking at each parameter per the 2131 * chunk type, i.e., unrecognized parameters should be further 2132 * identified based on the chunk id. 2133 */ 2134 2135 switch (param.p->type) { 2136 case SCTP_PARAM_IPV4_ADDRESS: 2137 case SCTP_PARAM_IPV6_ADDRESS: 2138 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2139 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2140 case SCTP_PARAM_STATE_COOKIE: 2141 case SCTP_PARAM_HEARTBEAT_INFO: 2142 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2143 case SCTP_PARAM_ECN_CAPABLE: 2144 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2145 break; 2146 2147 case SCTP_PARAM_SUPPORTED_EXT: 2148 if (!sctp_verify_ext_param(net, ep, param)) 2149 return SCTP_IERROR_ABORT; 2150 break; 2151 2152 case SCTP_PARAM_SET_PRIMARY: 2153 if (ep->asconf_enable) 2154 break; 2155 goto unhandled; 2156 2157 case SCTP_PARAM_HOST_NAME_ADDRESS: 2158 /* Tell the peer, we won't support this param. */ 2159 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2160 retval = SCTP_IERROR_ABORT; 2161 break; 2162 2163 case SCTP_PARAM_FWD_TSN_SUPPORT: 2164 if (ep->prsctp_enable) 2165 break; 2166 goto unhandled; 2167 2168 case SCTP_PARAM_RANDOM: 2169 if (!ep->auth_enable) 2170 goto unhandled; 2171 2172 /* SCTP-AUTH: Secion 6.1 2173 * If the random number is not 32 byte long the association 2174 * MUST be aborted. The ABORT chunk SHOULD contain the error 2175 * cause 'Protocol Violation'. 2176 */ 2177 if (SCTP_AUTH_RANDOM_LENGTH != ntohs(param.p->length) - 2178 sizeof(struct sctp_paramhdr)) { 2179 sctp_process_inv_paramlength(asoc, param.p, 2180 chunk, err_chunk); 2181 retval = SCTP_IERROR_ABORT; 2182 } 2183 break; 2184 2185 case SCTP_PARAM_CHUNKS: 2186 if (!ep->auth_enable) 2187 goto unhandled; 2188 2189 /* SCTP-AUTH: Section 3.2 2190 * The CHUNKS parameter MUST be included once in the INIT or 2191 * INIT-ACK chunk if the sender wants to receive authenticated 2192 * chunks. Its maximum length is 260 bytes. 2193 */ 2194 if (260 < ntohs(param.p->length)) { 2195 sctp_process_inv_paramlength(asoc, param.p, 2196 chunk, err_chunk); 2197 retval = SCTP_IERROR_ABORT; 2198 } 2199 break; 2200 2201 case SCTP_PARAM_HMAC_ALGO: 2202 if (!ep->auth_enable) 2203 goto unhandled; 2204 2205 hmacs = (struct sctp_hmac_algo_param *)param.p; 2206 n_elt = (ntohs(param.p->length) - 2207 sizeof(struct sctp_paramhdr)) >> 1; 2208 2209 /* SCTP-AUTH: Section 6.1 2210 * The HMAC algorithm based on SHA-1 MUST be supported and 2211 * included in the HMAC-ALGO parameter. 2212 */ 2213 for (i = 0; i < n_elt; i++) { 2214 id = ntohs(hmacs->hmac_ids[i]); 2215 2216 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2217 break; 2218 } 2219 2220 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2221 sctp_process_inv_paramlength(asoc, param.p, chunk, 2222 err_chunk); 2223 retval = SCTP_IERROR_ABORT; 2224 } 2225 break; 2226 unhandled: 2227 default: 2228 pr_debug("%s: unrecognized param:%d for chunk:%d\n", 2229 __func__, ntohs(param.p->type), cid); 2230 2231 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2232 break; 2233 } 2234 return retval; 2235 } 2236 2237 /* Verify the INIT packet before we process it. */ 2238 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 2239 const struct sctp_association *asoc, enum sctp_cid cid, 2240 struct sctp_init_chunk *peer_init, 2241 struct sctp_chunk *chunk, struct sctp_chunk **errp) 2242 { 2243 union sctp_params param; 2244 bool has_cookie = false; 2245 int result; 2246 2247 /* Check for missing mandatory parameters. Note: Initial TSN is 2248 * also mandatory, but is not checked here since the valid range 2249 * is 0..2**32-1. RFC4960, section 3.3.3. 2250 */ 2251 if (peer_init->init_hdr.num_outbound_streams == 0 || 2252 peer_init->init_hdr.num_inbound_streams == 0 || 2253 peer_init->init_hdr.init_tag == 0 || 2254 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) 2255 return sctp_process_inv_mandatory(asoc, chunk, errp); 2256 2257 sctp_walk_params(param, peer_init, init_hdr.params) { 2258 if (param.p->type == SCTP_PARAM_STATE_COOKIE) 2259 has_cookie = true; 2260 } 2261 2262 /* There is a possibility that a parameter length was bad and 2263 * in that case we would have stoped walking the parameters. 2264 * The current param.p would point at the bad one. 2265 * Current consensus on the mailing list is to generate a PROTOCOL 2266 * VIOLATION error. We build the ERROR chunk here and let the normal 2267 * error handling code build and send the packet. 2268 */ 2269 if (param.v != (void *)chunk->chunk_end) 2270 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2271 2272 /* The only missing mandatory param possible today is 2273 * the state cookie for an INIT-ACK chunk. 2274 */ 2275 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2276 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2277 chunk, errp); 2278 2279 /* Verify all the variable length parameters */ 2280 sctp_walk_params(param, peer_init, init_hdr.params) { 2281 result = sctp_verify_param(net, ep, asoc, param, cid, 2282 chunk, errp); 2283 switch (result) { 2284 case SCTP_IERROR_ABORT: 2285 case SCTP_IERROR_NOMEM: 2286 return 0; 2287 case SCTP_IERROR_ERROR: 2288 return 1; 2289 case SCTP_IERROR_NO_ERROR: 2290 default: 2291 break; 2292 } 2293 2294 } /* for (loop through all parameters) */ 2295 2296 return 1; 2297 } 2298 2299 /* Unpack the parameters in an INIT packet into an association. 2300 * Returns 0 on failure, else success. 2301 * FIXME: This is an association method. 2302 */ 2303 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2304 const union sctp_addr *peer_addr, 2305 struct sctp_init_chunk *peer_init, gfp_t gfp) 2306 { 2307 struct sctp_transport *transport; 2308 struct list_head *pos, *temp; 2309 union sctp_params param; 2310 union sctp_addr addr; 2311 struct sctp_af *af; 2312 int src_match = 0; 2313 2314 /* We must include the address that the INIT packet came from. 2315 * This is the only address that matters for an INIT packet. 2316 * When processing a COOKIE ECHO, we retrieve the from address 2317 * of the INIT from the cookie. 2318 */ 2319 2320 /* This implementation defaults to making the first transport 2321 * added as the primary transport. The source address seems to 2322 * be a better choice than any of the embedded addresses. 2323 */ 2324 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2325 goto nomem; 2326 2327 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2328 src_match = 1; 2329 2330 /* Process the initialization parameters. */ 2331 sctp_walk_params(param, peer_init, init_hdr.params) { 2332 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2333 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2334 af = sctp_get_af_specific(param_type2af(param.p->type)); 2335 af->from_addr_param(&addr, param.addr, 2336 chunk->sctp_hdr->source, 0); 2337 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2338 src_match = 1; 2339 } 2340 2341 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2342 goto clean_up; 2343 } 2344 2345 /* source address of chunk may not match any valid address */ 2346 if (!src_match) 2347 goto clean_up; 2348 2349 /* AUTH: After processing the parameters, make sure that we 2350 * have all the required info to potentially do authentications. 2351 */ 2352 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2353 !asoc->peer.peer_hmacs)) 2354 asoc->peer.auth_capable = 0; 2355 2356 /* In a non-backward compatible mode, if the peer claims 2357 * support for ADD-IP but not AUTH, the ADD-IP spec states 2358 * that we MUST ABORT the association. Section 6. The section 2359 * also give us an option to silently ignore the packet, which 2360 * is what we'll do here. 2361 */ 2362 if (!asoc->base.net->sctp.addip_noauth && 2363 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2364 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2365 SCTP_PARAM_DEL_IP | 2366 SCTP_PARAM_SET_PRIMARY); 2367 asoc->peer.asconf_capable = 0; 2368 goto clean_up; 2369 } 2370 2371 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2372 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2373 transport = list_entry(pos, struct sctp_transport, transports); 2374 if (transport->state == SCTP_UNKNOWN) { 2375 sctp_assoc_rm_peer(asoc, transport); 2376 } 2377 } 2378 2379 /* The fixed INIT headers are always in network byte 2380 * order. 2381 */ 2382 asoc->peer.i.init_tag = 2383 ntohl(peer_init->init_hdr.init_tag); 2384 asoc->peer.i.a_rwnd = 2385 ntohl(peer_init->init_hdr.a_rwnd); 2386 asoc->peer.i.num_outbound_streams = 2387 ntohs(peer_init->init_hdr.num_outbound_streams); 2388 asoc->peer.i.num_inbound_streams = 2389 ntohs(peer_init->init_hdr.num_inbound_streams); 2390 asoc->peer.i.initial_tsn = 2391 ntohl(peer_init->init_hdr.initial_tsn); 2392 2393 asoc->strreset_inseq = asoc->peer.i.initial_tsn; 2394 2395 /* Apply the upper bounds for output streams based on peer's 2396 * number of inbound streams. 2397 */ 2398 if (asoc->c.sinit_num_ostreams > 2399 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2400 asoc->c.sinit_num_ostreams = 2401 ntohs(peer_init->init_hdr.num_inbound_streams); 2402 } 2403 2404 if (asoc->c.sinit_max_instreams > 2405 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2406 asoc->c.sinit_max_instreams = 2407 ntohs(peer_init->init_hdr.num_outbound_streams); 2408 } 2409 2410 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2411 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2412 2413 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2414 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2415 2416 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2417 * high (for example, implementations MAY use the size of the receiver 2418 * advertised window). 2419 */ 2420 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2421 transports) { 2422 transport->ssthresh = asoc->peer.i.a_rwnd; 2423 } 2424 2425 /* Set up the TSN tracking pieces. */ 2426 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2427 asoc->peer.i.initial_tsn, gfp)) 2428 goto clean_up; 2429 2430 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2431 * 2432 * The stream sequence number in all the streams shall start 2433 * from 0 when the association is established. Also, when the 2434 * stream sequence number reaches the value 65535 the next 2435 * stream sequence number shall be set to 0. 2436 */ 2437 2438 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams, 2439 asoc->c.sinit_max_instreams, gfp)) 2440 goto clean_up; 2441 2442 /* Update frag_point when stream_interleave may get changed. */ 2443 sctp_assoc_update_frag_point(asoc); 2444 2445 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp)) 2446 goto clean_up; 2447 2448 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2449 * 2450 * When an endpoint has an ASCONF signaled change to be sent to the 2451 * remote endpoint it should do the following: 2452 * ... 2453 * A2) A serial number should be assigned to the Chunk. The serial 2454 * number should be a monotonically increasing number. All serial 2455 * numbers are defined to be initialized at the start of the 2456 * association to the same value as the Initial TSN. 2457 */ 2458 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2459 return 1; 2460 2461 clean_up: 2462 /* Release the transport structures. */ 2463 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2464 transport = list_entry(pos, struct sctp_transport, transports); 2465 if (transport->state != SCTP_ACTIVE) 2466 sctp_assoc_rm_peer(asoc, transport); 2467 } 2468 2469 nomem: 2470 return 0; 2471 } 2472 2473 2474 /* Update asoc with the option described in param. 2475 * 2476 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2477 * 2478 * asoc is the association to update. 2479 * param is the variable length parameter to use for update. 2480 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2481 * If the current packet is an INIT we want to minimize the amount of 2482 * work we do. In particular, we should not build transport 2483 * structures for the addresses. 2484 */ 2485 static int sctp_process_param(struct sctp_association *asoc, 2486 union sctp_params param, 2487 const union sctp_addr *peer_addr, 2488 gfp_t gfp) 2489 { 2490 struct sctp_endpoint *ep = asoc->ep; 2491 union sctp_addr_param *addr_param; 2492 struct net *net = asoc->base.net; 2493 struct sctp_transport *t; 2494 enum sctp_scope scope; 2495 union sctp_addr addr; 2496 struct sctp_af *af; 2497 int retval = 1, i; 2498 u32 stale; 2499 __u16 sat; 2500 2501 /* We maintain all INIT parameters in network byte order all the 2502 * time. This allows us to not worry about whether the parameters 2503 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2504 */ 2505 switch (param.p->type) { 2506 case SCTP_PARAM_IPV6_ADDRESS: 2507 if (PF_INET6 != asoc->base.sk->sk_family) 2508 break; 2509 goto do_addr_param; 2510 2511 case SCTP_PARAM_IPV4_ADDRESS: 2512 /* v4 addresses are not allowed on v6-only socket */ 2513 if (ipv6_only_sock(asoc->base.sk)) 2514 break; 2515 do_addr_param: 2516 af = sctp_get_af_specific(param_type2af(param.p->type)); 2517 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); 2518 scope = sctp_scope(peer_addr); 2519 if (sctp_in_scope(net, &addr, scope)) 2520 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2521 return 0; 2522 break; 2523 2524 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2525 if (!net->sctp.cookie_preserve_enable) 2526 break; 2527 2528 stale = ntohl(param.life->lifespan_increment); 2529 2530 /* Suggested Cookie Life span increment's unit is msec, 2531 * (1/1000sec). 2532 */ 2533 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale); 2534 break; 2535 2536 case SCTP_PARAM_HOST_NAME_ADDRESS: 2537 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__); 2538 break; 2539 2540 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2541 /* Turn off the default values first so we'll know which 2542 * ones are really set by the peer. 2543 */ 2544 asoc->peer.ipv4_address = 0; 2545 asoc->peer.ipv6_address = 0; 2546 2547 /* Assume that peer supports the address family 2548 * by which it sends a packet. 2549 */ 2550 if (peer_addr->sa.sa_family == AF_INET6) 2551 asoc->peer.ipv6_address = 1; 2552 else if (peer_addr->sa.sa_family == AF_INET) 2553 asoc->peer.ipv4_address = 1; 2554 2555 /* Cycle through address types; avoid divide by 0. */ 2556 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2557 if (sat) 2558 sat /= sizeof(__u16); 2559 2560 for (i = 0; i < sat; ++i) { 2561 switch (param.sat->types[i]) { 2562 case SCTP_PARAM_IPV4_ADDRESS: 2563 asoc->peer.ipv4_address = 1; 2564 break; 2565 2566 case SCTP_PARAM_IPV6_ADDRESS: 2567 if (PF_INET6 == asoc->base.sk->sk_family) 2568 asoc->peer.ipv6_address = 1; 2569 break; 2570 2571 case SCTP_PARAM_HOST_NAME_ADDRESS: 2572 asoc->peer.hostname_address = 1; 2573 break; 2574 2575 default: /* Just ignore anything else. */ 2576 break; 2577 } 2578 } 2579 break; 2580 2581 case SCTP_PARAM_STATE_COOKIE: 2582 asoc->peer.cookie_len = 2583 ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2584 kfree(asoc->peer.cookie); 2585 asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp); 2586 if (!asoc->peer.cookie) 2587 retval = 0; 2588 break; 2589 2590 case SCTP_PARAM_HEARTBEAT_INFO: 2591 /* Would be odd to receive, but it causes no problems. */ 2592 break; 2593 2594 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2595 /* Rejected during verify stage. */ 2596 break; 2597 2598 case SCTP_PARAM_ECN_CAPABLE: 2599 if (asoc->ep->ecn_enable) { 2600 asoc->peer.ecn_capable = 1; 2601 break; 2602 } 2603 /* Fall Through */ 2604 goto fall_through; 2605 2606 2607 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2608 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2609 break; 2610 2611 case SCTP_PARAM_SET_PRIMARY: 2612 if (!ep->asconf_enable) 2613 goto fall_through; 2614 2615 addr_param = param.v + sizeof(struct sctp_addip_param); 2616 2617 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 2618 if (af == NULL) 2619 break; 2620 2621 af->from_addr_param(&addr, addr_param, 2622 htons(asoc->peer.port), 0); 2623 2624 /* if the address is invalid, we can't process it. 2625 * XXX: see spec for what to do. 2626 */ 2627 if (!af->addr_valid(&addr, NULL, NULL)) 2628 break; 2629 2630 t = sctp_assoc_lookup_paddr(asoc, &addr); 2631 if (!t) 2632 break; 2633 2634 sctp_assoc_set_primary(asoc, t); 2635 break; 2636 2637 case SCTP_PARAM_SUPPORTED_EXT: 2638 sctp_process_ext_param(asoc, param); 2639 break; 2640 2641 case SCTP_PARAM_FWD_TSN_SUPPORT: 2642 if (asoc->ep->prsctp_enable) { 2643 asoc->peer.prsctp_capable = 1; 2644 break; 2645 } 2646 /* Fall Through */ 2647 goto fall_through; 2648 2649 case SCTP_PARAM_RANDOM: 2650 if (!ep->auth_enable) 2651 goto fall_through; 2652 2653 /* Save peer's random parameter */ 2654 kfree(asoc->peer.peer_random); 2655 asoc->peer.peer_random = kmemdup(param.p, 2656 ntohs(param.p->length), gfp); 2657 if (!asoc->peer.peer_random) { 2658 retval = 0; 2659 break; 2660 } 2661 break; 2662 2663 case SCTP_PARAM_HMAC_ALGO: 2664 if (!ep->auth_enable) 2665 goto fall_through; 2666 2667 /* Save peer's HMAC list */ 2668 kfree(asoc->peer.peer_hmacs); 2669 asoc->peer.peer_hmacs = kmemdup(param.p, 2670 ntohs(param.p->length), gfp); 2671 if (!asoc->peer.peer_hmacs) { 2672 retval = 0; 2673 break; 2674 } 2675 2676 /* Set the default HMAC the peer requested*/ 2677 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2678 break; 2679 2680 case SCTP_PARAM_CHUNKS: 2681 if (!ep->auth_enable) 2682 goto fall_through; 2683 2684 kfree(asoc->peer.peer_chunks); 2685 asoc->peer.peer_chunks = kmemdup(param.p, 2686 ntohs(param.p->length), gfp); 2687 if (!asoc->peer.peer_chunks) 2688 retval = 0; 2689 break; 2690 fall_through: 2691 default: 2692 /* Any unrecognized parameters should have been caught 2693 * and handled by sctp_verify_param() which should be 2694 * called prior to this routine. Simply log the error 2695 * here. 2696 */ 2697 pr_debug("%s: ignoring param:%d for association:%p.\n", 2698 __func__, ntohs(param.p->type), asoc); 2699 break; 2700 } 2701 2702 return retval; 2703 } 2704 2705 /* Select a new verification tag. */ 2706 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2707 { 2708 /* I believe that this random number generator complies with RFC1750. 2709 * A tag of 0 is reserved for special cases (e.g. INIT). 2710 */ 2711 __u32 x; 2712 2713 do { 2714 get_random_bytes(&x, sizeof(__u32)); 2715 } while (x == 0); 2716 2717 return x; 2718 } 2719 2720 /* Select an initial TSN to send during startup. */ 2721 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2722 { 2723 __u32 retval; 2724 2725 get_random_bytes(&retval, sizeof(__u32)); 2726 return retval; 2727 } 2728 2729 /* 2730 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2731 * 0 1 2 3 2732 * 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 2733 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2734 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2735 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2736 * | Serial Number | 2737 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2738 * | Address Parameter | 2739 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2740 * | ASCONF Parameter #1 | 2741 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2742 * \ \ 2743 * / .... / 2744 * \ \ 2745 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2746 * | ASCONF Parameter #N | 2747 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2748 * 2749 * Address Parameter and other parameter will not be wrapped in this function 2750 */ 2751 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2752 union sctp_addr *addr, 2753 int vparam_len) 2754 { 2755 struct sctp_addiphdr asconf; 2756 struct sctp_chunk *retval; 2757 int length = sizeof(asconf) + vparam_len; 2758 union sctp_addr_param addrparam; 2759 int addrlen; 2760 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2761 2762 addrlen = af->to_addr_param(addr, &addrparam); 2763 if (!addrlen) 2764 return NULL; 2765 length += addrlen; 2766 2767 /* Create the chunk. */ 2768 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length, 2769 GFP_ATOMIC); 2770 if (!retval) 2771 return NULL; 2772 2773 asconf.serial = htonl(asoc->addip_serial++); 2774 2775 retval->subh.addip_hdr = 2776 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2777 retval->param_hdr.v = 2778 sctp_addto_chunk(retval, addrlen, &addrparam); 2779 2780 return retval; 2781 } 2782 2783 /* ADDIP 2784 * 3.2.1 Add IP Address 2785 * 0 1 2 3 2786 * 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 2787 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2788 * | Type = 0xC001 | Length = Variable | 2789 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2790 * | ASCONF-Request Correlation ID | 2791 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2792 * | Address Parameter | 2793 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2794 * 2795 * 3.2.2 Delete IP Address 2796 * 0 1 2 3 2797 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2798 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2799 * | Type = 0xC002 | Length = Variable | 2800 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2801 * | ASCONF-Request Correlation ID | 2802 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2803 * | Address Parameter | 2804 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2805 * 2806 */ 2807 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2808 union sctp_addr *laddr, 2809 struct sockaddr *addrs, 2810 int addrcnt, __be16 flags) 2811 { 2812 union sctp_addr_param addr_param; 2813 struct sctp_addip_param param; 2814 int paramlen = sizeof(param); 2815 struct sctp_chunk *retval; 2816 int addr_param_len = 0; 2817 union sctp_addr *addr; 2818 int totallen = 0, i; 2819 int del_pickup = 0; 2820 struct sctp_af *af; 2821 void *addr_buf; 2822 2823 /* Get total length of all the address parameters. */ 2824 addr_buf = addrs; 2825 for (i = 0; i < addrcnt; i++) { 2826 addr = addr_buf; 2827 af = sctp_get_af_specific(addr->v4.sin_family); 2828 addr_param_len = af->to_addr_param(addr, &addr_param); 2829 2830 totallen += paramlen; 2831 totallen += addr_param_len; 2832 2833 addr_buf += af->sockaddr_len; 2834 if (asoc->asconf_addr_del_pending && !del_pickup) { 2835 /* reuse the parameter length from the same scope one */ 2836 totallen += paramlen; 2837 totallen += addr_param_len; 2838 del_pickup = 1; 2839 2840 pr_debug("%s: picked same-scope del_pending addr, " 2841 "totallen for all addresses is %d\n", 2842 __func__, totallen); 2843 } 2844 } 2845 2846 /* Create an asconf chunk with the required length. */ 2847 retval = sctp_make_asconf(asoc, laddr, totallen); 2848 if (!retval) 2849 return NULL; 2850 2851 /* Add the address parameters to the asconf chunk. */ 2852 addr_buf = addrs; 2853 for (i = 0; i < addrcnt; i++) { 2854 addr = addr_buf; 2855 af = sctp_get_af_specific(addr->v4.sin_family); 2856 addr_param_len = af->to_addr_param(addr, &addr_param); 2857 param.param_hdr.type = flags; 2858 param.param_hdr.length = htons(paramlen + addr_param_len); 2859 param.crr_id = htonl(i); 2860 2861 sctp_addto_chunk(retval, paramlen, ¶m); 2862 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2863 2864 addr_buf += af->sockaddr_len; 2865 } 2866 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2867 addr = asoc->asconf_addr_del_pending; 2868 af = sctp_get_af_specific(addr->v4.sin_family); 2869 addr_param_len = af->to_addr_param(addr, &addr_param); 2870 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2871 param.param_hdr.length = htons(paramlen + addr_param_len); 2872 param.crr_id = htonl(i); 2873 2874 sctp_addto_chunk(retval, paramlen, ¶m); 2875 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2876 } 2877 return retval; 2878 } 2879 2880 /* ADDIP 2881 * 3.2.4 Set Primary IP Address 2882 * 0 1 2 3 2883 * 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 2884 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2885 * | Type =0xC004 | Length = Variable | 2886 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2887 * | ASCONF-Request Correlation ID | 2888 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2889 * | Address Parameter | 2890 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2891 * 2892 * Create an ASCONF chunk with Set Primary IP address parameter. 2893 */ 2894 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2895 union sctp_addr *addr) 2896 { 2897 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2898 union sctp_addr_param addrparam; 2899 struct sctp_addip_param param; 2900 struct sctp_chunk *retval; 2901 int len = sizeof(param); 2902 int addrlen; 2903 2904 addrlen = af->to_addr_param(addr, &addrparam); 2905 if (!addrlen) 2906 return NULL; 2907 len += addrlen; 2908 2909 /* Create the chunk and make asconf header. */ 2910 retval = sctp_make_asconf(asoc, addr, len); 2911 if (!retval) 2912 return NULL; 2913 2914 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2915 param.param_hdr.length = htons(len); 2916 param.crr_id = 0; 2917 2918 sctp_addto_chunk(retval, sizeof(param), ¶m); 2919 sctp_addto_chunk(retval, addrlen, &addrparam); 2920 2921 return retval; 2922 } 2923 2924 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2925 * 0 1 2 3 2926 * 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 2927 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2928 * | Type = 0x80 | Chunk Flags | Chunk Length | 2929 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2930 * | Serial Number | 2931 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2932 * | ASCONF Parameter Response#1 | 2933 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2934 * \ \ 2935 * / .... / 2936 * \ \ 2937 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2938 * | ASCONF Parameter Response#N | 2939 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2940 * 2941 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2942 */ 2943 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2944 __u32 serial, int vparam_len) 2945 { 2946 struct sctp_addiphdr asconf; 2947 struct sctp_chunk *retval; 2948 int length = sizeof(asconf) + vparam_len; 2949 2950 /* Create the chunk. */ 2951 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length, 2952 GFP_ATOMIC); 2953 if (!retval) 2954 return NULL; 2955 2956 asconf.serial = htonl(serial); 2957 2958 retval->subh.addip_hdr = 2959 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2960 2961 return retval; 2962 } 2963 2964 /* Add response parameters to an ASCONF_ACK chunk. */ 2965 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2966 __be16 err_code, 2967 struct sctp_addip_param *asconf_param) 2968 { 2969 struct sctp_addip_param ack_param; 2970 struct sctp_errhdr err_param; 2971 int asconf_param_len = 0; 2972 int err_param_len = 0; 2973 __be16 response_type; 2974 2975 if (SCTP_ERROR_NO_ERROR == err_code) { 2976 response_type = SCTP_PARAM_SUCCESS_REPORT; 2977 } else { 2978 response_type = SCTP_PARAM_ERR_CAUSE; 2979 err_param_len = sizeof(err_param); 2980 if (asconf_param) 2981 asconf_param_len = 2982 ntohs(asconf_param->param_hdr.length); 2983 } 2984 2985 /* Add Success Indication or Error Cause Indication parameter. */ 2986 ack_param.param_hdr.type = response_type; 2987 ack_param.param_hdr.length = htons(sizeof(ack_param) + 2988 err_param_len + 2989 asconf_param_len); 2990 ack_param.crr_id = crr_id; 2991 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 2992 2993 if (SCTP_ERROR_NO_ERROR == err_code) 2994 return; 2995 2996 /* Add Error Cause parameter. */ 2997 err_param.cause = err_code; 2998 err_param.length = htons(err_param_len + asconf_param_len); 2999 sctp_addto_chunk(chunk, err_param_len, &err_param); 3000 3001 /* Add the failed TLV copied from ASCONF chunk. */ 3002 if (asconf_param) 3003 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 3004 } 3005 3006 /* Process a asconf parameter. */ 3007 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 3008 struct sctp_chunk *asconf, 3009 struct sctp_addip_param *asconf_param) 3010 { 3011 union sctp_addr_param *addr_param; 3012 struct sctp_transport *peer; 3013 union sctp_addr addr; 3014 struct sctp_af *af; 3015 3016 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3017 3018 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 3019 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 3020 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 3021 return SCTP_ERROR_UNKNOWN_PARAM; 3022 3023 switch (addr_param->p.type) { 3024 case SCTP_PARAM_IPV6_ADDRESS: 3025 if (!asoc->peer.ipv6_address) 3026 return SCTP_ERROR_DNS_FAILED; 3027 break; 3028 case SCTP_PARAM_IPV4_ADDRESS: 3029 if (!asoc->peer.ipv4_address) 3030 return SCTP_ERROR_DNS_FAILED; 3031 break; 3032 default: 3033 return SCTP_ERROR_DNS_FAILED; 3034 } 3035 3036 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3037 if (unlikely(!af)) 3038 return SCTP_ERROR_DNS_FAILED; 3039 3040 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); 3041 3042 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3043 * or multicast address. 3044 * (note: wildcard is permitted and requires special handling so 3045 * make sure we check for that) 3046 */ 3047 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3048 return SCTP_ERROR_DNS_FAILED; 3049 3050 switch (asconf_param->param_hdr.type) { 3051 case SCTP_PARAM_ADD_IP: 3052 /* Section 4.2.1: 3053 * If the address 0.0.0.0 or ::0 is provided, the source 3054 * address of the packet MUST be added. 3055 */ 3056 if (af->is_any(&addr)) 3057 memcpy(&addr, &asconf->source, sizeof(addr)); 3058 3059 if (security_sctp_bind_connect(asoc->ep->base.sk, 3060 SCTP_PARAM_ADD_IP, 3061 (struct sockaddr *)&addr, 3062 af->sockaddr_len)) 3063 return SCTP_ERROR_REQ_REFUSED; 3064 3065 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3066 * request and does not have the local resources to add this 3067 * new address to the association, it MUST return an Error 3068 * Cause TLV set to the new error code 'Operation Refused 3069 * Due to Resource Shortage'. 3070 */ 3071 3072 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3073 if (!peer) 3074 return SCTP_ERROR_RSRC_LOW; 3075 3076 /* Start the heartbeat timer. */ 3077 sctp_transport_reset_hb_timer(peer); 3078 asoc->new_transport = peer; 3079 break; 3080 case SCTP_PARAM_DEL_IP: 3081 /* ADDIP 4.3 D7) If a request is received to delete the 3082 * last remaining IP address of a peer endpoint, the receiver 3083 * MUST send an Error Cause TLV with the error cause set to the 3084 * new error code 'Request to Delete Last Remaining IP Address'. 3085 */ 3086 if (asoc->peer.transport_count == 1) 3087 return SCTP_ERROR_DEL_LAST_IP; 3088 3089 /* ADDIP 4.3 D8) If a request is received to delete an IP 3090 * address which is also the source address of the IP packet 3091 * which contained the ASCONF chunk, the receiver MUST reject 3092 * this request. To reject the request the receiver MUST send 3093 * an Error Cause TLV set to the new error code 'Request to 3094 * Delete Source IP Address' 3095 */ 3096 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3097 return SCTP_ERROR_DEL_SRC_IP; 3098 3099 /* Section 4.2.2 3100 * If the address 0.0.0.0 or ::0 is provided, all 3101 * addresses of the peer except the source address of the 3102 * packet MUST be deleted. 3103 */ 3104 if (af->is_any(&addr)) { 3105 sctp_assoc_set_primary(asoc, asconf->transport); 3106 sctp_assoc_del_nonprimary_peers(asoc, 3107 asconf->transport); 3108 return SCTP_ERROR_NO_ERROR; 3109 } 3110 3111 /* If the address is not part of the association, the 3112 * ASCONF-ACK with Error Cause Indication Parameter 3113 * which including cause of Unresolvable Address should 3114 * be sent. 3115 */ 3116 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3117 if (!peer) 3118 return SCTP_ERROR_DNS_FAILED; 3119 3120 sctp_assoc_rm_peer(asoc, peer); 3121 break; 3122 case SCTP_PARAM_SET_PRIMARY: 3123 /* ADDIP Section 4.2.4 3124 * If the address 0.0.0.0 or ::0 is provided, the receiver 3125 * MAY mark the source address of the packet as its 3126 * primary. 3127 */ 3128 if (af->is_any(&addr)) 3129 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr)); 3130 3131 if (security_sctp_bind_connect(asoc->ep->base.sk, 3132 SCTP_PARAM_SET_PRIMARY, 3133 (struct sockaddr *)&addr, 3134 af->sockaddr_len)) 3135 return SCTP_ERROR_REQ_REFUSED; 3136 3137 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3138 if (!peer) 3139 return SCTP_ERROR_DNS_FAILED; 3140 3141 sctp_assoc_set_primary(asoc, peer); 3142 break; 3143 } 3144 3145 return SCTP_ERROR_NO_ERROR; 3146 } 3147 3148 /* Verify the ASCONF packet before we process it. */ 3149 bool sctp_verify_asconf(const struct sctp_association *asoc, 3150 struct sctp_chunk *chunk, bool addr_param_needed, 3151 struct sctp_paramhdr **errp) 3152 { 3153 struct sctp_addip_chunk *addip; 3154 bool addr_param_seen = false; 3155 union sctp_params param; 3156 3157 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr; 3158 sctp_walk_params(param, addip, addip_hdr.params) { 3159 size_t length = ntohs(param.p->length); 3160 3161 *errp = param.p; 3162 switch (param.p->type) { 3163 case SCTP_PARAM_ERR_CAUSE: 3164 break; 3165 case SCTP_PARAM_IPV4_ADDRESS: 3166 if (length != sizeof(struct sctp_ipv4addr_param)) 3167 return false; 3168 /* ensure there is only one addr param and it's in the 3169 * beginning of addip_hdr params, or we reject it. 3170 */ 3171 if (param.v != addip->addip_hdr.params) 3172 return false; 3173 addr_param_seen = true; 3174 break; 3175 case SCTP_PARAM_IPV6_ADDRESS: 3176 if (length != sizeof(struct sctp_ipv6addr_param)) 3177 return false; 3178 if (param.v != addip->addip_hdr.params) 3179 return false; 3180 addr_param_seen = true; 3181 break; 3182 case SCTP_PARAM_ADD_IP: 3183 case SCTP_PARAM_DEL_IP: 3184 case SCTP_PARAM_SET_PRIMARY: 3185 /* In ASCONF chunks, these need to be first. */ 3186 if (addr_param_needed && !addr_param_seen) 3187 return false; 3188 length = ntohs(param.addip->param_hdr.length); 3189 if (length < sizeof(struct sctp_addip_param) + 3190 sizeof(**errp)) 3191 return false; 3192 break; 3193 case SCTP_PARAM_SUCCESS_REPORT: 3194 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3195 if (length != sizeof(struct sctp_addip_param)) 3196 return false; 3197 break; 3198 default: 3199 /* This is unkown to us, reject! */ 3200 return false; 3201 } 3202 } 3203 3204 /* Remaining sanity checks. */ 3205 if (addr_param_needed && !addr_param_seen) 3206 return false; 3207 if (!addr_param_needed && addr_param_seen) 3208 return false; 3209 if (param.v != chunk->chunk_end) 3210 return false; 3211 3212 return true; 3213 } 3214 3215 /* Process an incoming ASCONF chunk with the next expected serial no. and 3216 * return an ASCONF_ACK chunk to be sent in response. 3217 */ 3218 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3219 struct sctp_chunk *asconf) 3220 { 3221 union sctp_addr_param *addr_param; 3222 struct sctp_addip_chunk *addip; 3223 struct sctp_chunk *asconf_ack; 3224 bool all_param_pass = true; 3225 struct sctp_addiphdr *hdr; 3226 int length = 0, chunk_len; 3227 union sctp_params param; 3228 __be16 err_code; 3229 __u32 serial; 3230 3231 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr; 3232 chunk_len = ntohs(asconf->chunk_hdr->length) - 3233 sizeof(struct sctp_chunkhdr); 3234 hdr = (struct sctp_addiphdr *)asconf->skb->data; 3235 serial = ntohl(hdr->serial); 3236 3237 /* Skip the addiphdr and store a pointer to address parameter. */ 3238 length = sizeof(*hdr); 3239 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3240 chunk_len -= length; 3241 3242 /* Skip the address parameter and store a pointer to the first 3243 * asconf parameter. 3244 */ 3245 length = ntohs(addr_param->p.length); 3246 chunk_len -= length; 3247 3248 /* create an ASCONF_ACK chunk. 3249 * Based on the definitions of parameters, we know that the size of 3250 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3251 * parameters. 3252 */ 3253 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3254 if (!asconf_ack) 3255 goto done; 3256 3257 /* Process the TLVs contained within the ASCONF chunk. */ 3258 sctp_walk_params(param, addip, addip_hdr.params) { 3259 /* Skip preceeding address parameters. */ 3260 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 3261 param.p->type == SCTP_PARAM_IPV6_ADDRESS) 3262 continue; 3263 3264 err_code = sctp_process_asconf_param(asoc, asconf, 3265 param.addip); 3266 /* ADDIP 4.1 A7) 3267 * If an error response is received for a TLV parameter, 3268 * all TLVs with no response before the failed TLV are 3269 * considered successful if not reported. All TLVs after 3270 * the failed response are considered unsuccessful unless 3271 * a specific success indication is present for the parameter. 3272 */ 3273 if (err_code != SCTP_ERROR_NO_ERROR) 3274 all_param_pass = false; 3275 if (!all_param_pass) 3276 sctp_add_asconf_response(asconf_ack, param.addip->crr_id, 3277 err_code, param.addip); 3278 3279 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3280 * an IP address sends an 'Out of Resource' in its response, it 3281 * MUST also fail any subsequent add or delete requests bundled 3282 * in the ASCONF. 3283 */ 3284 if (err_code == SCTP_ERROR_RSRC_LOW) 3285 goto done; 3286 } 3287 done: 3288 asoc->peer.addip_serial++; 3289 3290 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3291 * after freeing the reference to old asconf ack if any. 3292 */ 3293 if (asconf_ack) { 3294 sctp_chunk_hold(asconf_ack); 3295 list_add_tail(&asconf_ack->transmitted_list, 3296 &asoc->asconf_ack_list); 3297 } 3298 3299 return asconf_ack; 3300 } 3301 3302 /* Process a asconf parameter that is successfully acked. */ 3303 static void sctp_asconf_param_success(struct sctp_association *asoc, 3304 struct sctp_addip_param *asconf_param) 3305 { 3306 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3307 union sctp_addr_param *addr_param; 3308 struct sctp_sockaddr_entry *saddr; 3309 struct sctp_transport *transport; 3310 union sctp_addr addr; 3311 struct sctp_af *af; 3312 3313 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3314 3315 /* We have checked the packet before, so we do not check again. */ 3316 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3317 af->from_addr_param(&addr, addr_param, htons(bp->port), 0); 3318 3319 switch (asconf_param->param_hdr.type) { 3320 case SCTP_PARAM_ADD_IP: 3321 /* This is always done in BH context with a socket lock 3322 * held, so the list can not change. 3323 */ 3324 local_bh_disable(); 3325 list_for_each_entry(saddr, &bp->address_list, list) { 3326 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3327 saddr->state = SCTP_ADDR_SRC; 3328 } 3329 local_bh_enable(); 3330 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3331 transports) { 3332 sctp_transport_dst_release(transport); 3333 } 3334 break; 3335 case SCTP_PARAM_DEL_IP: 3336 local_bh_disable(); 3337 sctp_del_bind_addr(bp, &addr); 3338 if (asoc->asconf_addr_del_pending != NULL && 3339 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3340 kfree(asoc->asconf_addr_del_pending); 3341 asoc->asconf_addr_del_pending = NULL; 3342 } 3343 local_bh_enable(); 3344 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3345 transports) { 3346 sctp_transport_dst_release(transport); 3347 } 3348 break; 3349 default: 3350 break; 3351 } 3352 } 3353 3354 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3355 * for the given asconf parameter. If there is no response for this parameter, 3356 * return the error code based on the third argument 'no_err'. 3357 * ADDIP 4.1 3358 * A7) If an error response is received for a TLV parameter, all TLVs with no 3359 * response before the failed TLV are considered successful if not reported. 3360 * All TLVs after the failed response are considered unsuccessful unless a 3361 * specific success indication is present for the parameter. 3362 */ 3363 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3364 struct sctp_addip_param *asconf_param, 3365 int no_err) 3366 { 3367 struct sctp_addip_param *asconf_ack_param; 3368 struct sctp_errhdr *err_param; 3369 int asconf_ack_len; 3370 __be16 err_code; 3371 int length; 3372 3373 if (no_err) 3374 err_code = SCTP_ERROR_NO_ERROR; 3375 else 3376 err_code = SCTP_ERROR_REQ_REFUSED; 3377 3378 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3379 sizeof(struct sctp_chunkhdr); 3380 3381 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3382 * the first asconf_ack parameter. 3383 */ 3384 length = sizeof(struct sctp_addiphdr); 3385 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data + 3386 length); 3387 asconf_ack_len -= length; 3388 3389 while (asconf_ack_len > 0) { 3390 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3391 switch (asconf_ack_param->param_hdr.type) { 3392 case SCTP_PARAM_SUCCESS_REPORT: 3393 return SCTP_ERROR_NO_ERROR; 3394 case SCTP_PARAM_ERR_CAUSE: 3395 length = sizeof(*asconf_ack_param); 3396 err_param = (void *)asconf_ack_param + length; 3397 asconf_ack_len -= length; 3398 if (asconf_ack_len > 0) 3399 return err_param->cause; 3400 else 3401 return SCTP_ERROR_INV_PARAM; 3402 break; 3403 default: 3404 return SCTP_ERROR_INV_PARAM; 3405 } 3406 } 3407 3408 length = ntohs(asconf_ack_param->param_hdr.length); 3409 asconf_ack_param = (void *)asconf_ack_param + length; 3410 asconf_ack_len -= length; 3411 } 3412 3413 return err_code; 3414 } 3415 3416 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3417 int sctp_process_asconf_ack(struct sctp_association *asoc, 3418 struct sctp_chunk *asconf_ack) 3419 { 3420 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3421 struct sctp_addip_param *asconf_param; 3422 __be16 err_code = SCTP_ERROR_NO_ERROR; 3423 union sctp_addr_param *addr_param; 3424 int asconf_len = asconf->skb->len; 3425 int all_param_pass = 0; 3426 int length = 0; 3427 int no_err = 1; 3428 int retval = 0; 3429 3430 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3431 * a pointer to address parameter. 3432 */ 3433 length = sizeof(struct sctp_addip_chunk); 3434 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3435 asconf_len -= length; 3436 3437 /* Skip the address parameter in the last asconf sent and store a 3438 * pointer to the first asconf parameter. 3439 */ 3440 length = ntohs(addr_param->p.length); 3441 asconf_param = (void *)addr_param + length; 3442 asconf_len -= length; 3443 3444 /* ADDIP 4.1 3445 * A8) If there is no response(s) to specific TLV parameter(s), and no 3446 * failures are indicated, then all request(s) are considered 3447 * successful. 3448 */ 3449 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr)) 3450 all_param_pass = 1; 3451 3452 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3453 while (asconf_len > 0) { 3454 if (all_param_pass) 3455 err_code = SCTP_ERROR_NO_ERROR; 3456 else { 3457 err_code = sctp_get_asconf_response(asconf_ack, 3458 asconf_param, 3459 no_err); 3460 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3461 no_err = 0; 3462 } 3463 3464 switch (err_code) { 3465 case SCTP_ERROR_NO_ERROR: 3466 sctp_asconf_param_success(asoc, asconf_param); 3467 break; 3468 3469 case SCTP_ERROR_RSRC_LOW: 3470 retval = 1; 3471 break; 3472 3473 case SCTP_ERROR_UNKNOWN_PARAM: 3474 /* Disable sending this type of asconf parameter in 3475 * future. 3476 */ 3477 asoc->peer.addip_disabled_mask |= 3478 asconf_param->param_hdr.type; 3479 break; 3480 3481 case SCTP_ERROR_REQ_REFUSED: 3482 case SCTP_ERROR_DEL_LAST_IP: 3483 case SCTP_ERROR_DEL_SRC_IP: 3484 default: 3485 break; 3486 } 3487 3488 /* Skip the processed asconf parameter and move to the next 3489 * one. 3490 */ 3491 length = ntohs(asconf_param->param_hdr.length); 3492 asconf_param = (void *)asconf_param + length; 3493 asconf_len -= length; 3494 } 3495 3496 if (no_err && asoc->src_out_of_asoc_ok) { 3497 asoc->src_out_of_asoc_ok = 0; 3498 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3499 } 3500 3501 /* Free the cached last sent asconf chunk. */ 3502 list_del_init(&asconf->transmitted_list); 3503 sctp_chunk_free(asconf); 3504 asoc->addip_last_asconf = NULL; 3505 3506 return retval; 3507 } 3508 3509 /* Make a FWD TSN chunk. */ 3510 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3511 __u32 new_cum_tsn, size_t nstreams, 3512 struct sctp_fwdtsn_skip *skiplist) 3513 { 3514 struct sctp_chunk *retval = NULL; 3515 struct sctp_fwdtsn_hdr ftsn_hdr; 3516 struct sctp_fwdtsn_skip skip; 3517 size_t hint; 3518 int i; 3519 3520 hint = (nstreams + 1) * sizeof(__u32); 3521 3522 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC); 3523 3524 if (!retval) 3525 return NULL; 3526 3527 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3528 retval->subh.fwdtsn_hdr = 3529 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3530 3531 for (i = 0; i < nstreams; i++) { 3532 skip.stream = skiplist[i].stream; 3533 skip.ssn = skiplist[i].ssn; 3534 sctp_addto_chunk(retval, sizeof(skip), &skip); 3535 } 3536 3537 return retval; 3538 } 3539 3540 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc, 3541 __u32 new_cum_tsn, size_t nstreams, 3542 struct sctp_ifwdtsn_skip *skiplist) 3543 { 3544 struct sctp_chunk *retval = NULL; 3545 struct sctp_ifwdtsn_hdr ftsn_hdr; 3546 size_t hint; 3547 3548 hint = (nstreams + 1) * sizeof(__u32); 3549 3550 retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint, 3551 GFP_ATOMIC); 3552 if (!retval) 3553 return NULL; 3554 3555 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3556 retval->subh.ifwdtsn_hdr = 3557 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3558 3559 sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist); 3560 3561 return retval; 3562 } 3563 3564 /* RE-CONFIG 3.1 (RE-CONFIG chunk) 3565 * 0 1 2 3 3566 * 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 3567 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3568 * | Type = 130 | Chunk Flags | Chunk Length | 3569 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3570 * \ \ 3571 * / Re-configuration Parameter / 3572 * \ \ 3573 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3574 * \ \ 3575 * / Re-configuration Parameter (optional) / 3576 * \ \ 3577 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3578 */ 3579 static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc, 3580 int length) 3581 { 3582 struct sctp_reconf_chunk *reconf; 3583 struct sctp_chunk *retval; 3584 3585 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length, 3586 GFP_ATOMIC); 3587 if (!retval) 3588 return NULL; 3589 3590 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr; 3591 retval->param_hdr.v = reconf->params; 3592 3593 return retval; 3594 } 3595 3596 /* RE-CONFIG 4.1 (STREAM OUT RESET) 3597 * 0 1 2 3 3598 * 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 3599 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3600 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N | 3601 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3602 * | Re-configuration Request Sequence Number | 3603 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3604 * | Re-configuration Response Sequence Number | 3605 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3606 * | Sender's Last Assigned TSN | 3607 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3608 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3609 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3610 * / ...... / 3611 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3612 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3613 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3614 * 3615 * RE-CONFIG 4.2 (STREAM IN RESET) 3616 * 0 1 2 3 3617 * 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 3618 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3619 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N | 3620 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3621 * | Re-configuration Request Sequence Number | 3622 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3623 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3624 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3625 * / ...... / 3626 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3627 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3628 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3629 */ 3630 struct sctp_chunk *sctp_make_strreset_req( 3631 const struct sctp_association *asoc, 3632 __u16 stream_num, __be16 *stream_list, 3633 bool out, bool in) 3634 { 3635 __u16 stream_len = stream_num * sizeof(__u16); 3636 struct sctp_strreset_outreq outreq; 3637 struct sctp_strreset_inreq inreq; 3638 struct sctp_chunk *retval; 3639 __u16 outlen, inlen; 3640 3641 outlen = (sizeof(outreq) + stream_len) * out; 3642 inlen = (sizeof(inreq) + stream_len) * in; 3643 3644 retval = sctp_make_reconf(asoc, outlen + inlen); 3645 if (!retval) 3646 return NULL; 3647 3648 if (outlen) { 3649 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST; 3650 outreq.param_hdr.length = htons(outlen); 3651 outreq.request_seq = htonl(asoc->strreset_outseq); 3652 outreq.response_seq = htonl(asoc->strreset_inseq - 1); 3653 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1); 3654 3655 sctp_addto_chunk(retval, sizeof(outreq), &outreq); 3656 3657 if (stream_len) 3658 sctp_addto_chunk(retval, stream_len, stream_list); 3659 } 3660 3661 if (inlen) { 3662 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST; 3663 inreq.param_hdr.length = htons(inlen); 3664 inreq.request_seq = htonl(asoc->strreset_outseq + out); 3665 3666 sctp_addto_chunk(retval, sizeof(inreq), &inreq); 3667 3668 if (stream_len) 3669 sctp_addto_chunk(retval, stream_len, stream_list); 3670 } 3671 3672 return retval; 3673 } 3674 3675 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL) 3676 * 0 1 2 3 3677 * 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 3678 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3679 * | Parameter Type = 15 | Parameter Length = 8 | 3680 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3681 * | Re-configuration Request Sequence Number | 3682 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3683 */ 3684 struct sctp_chunk *sctp_make_strreset_tsnreq( 3685 const struct sctp_association *asoc) 3686 { 3687 struct sctp_strreset_tsnreq tsnreq; 3688 __u16 length = sizeof(tsnreq); 3689 struct sctp_chunk *retval; 3690 3691 retval = sctp_make_reconf(asoc, length); 3692 if (!retval) 3693 return NULL; 3694 3695 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST; 3696 tsnreq.param_hdr.length = htons(length); 3697 tsnreq.request_seq = htonl(asoc->strreset_outseq); 3698 3699 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq); 3700 3701 return retval; 3702 } 3703 3704 /* RE-CONFIG 4.5/4.6 (ADD STREAM) 3705 * 0 1 2 3 3706 * 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 3707 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3708 * | Parameter Type = 17 | Parameter Length = 12 | 3709 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3710 * | Re-configuration Request Sequence Number | 3711 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3712 * | Number of new streams | Reserved | 3713 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3714 */ 3715 struct sctp_chunk *sctp_make_strreset_addstrm( 3716 const struct sctp_association *asoc, 3717 __u16 out, __u16 in) 3718 { 3719 struct sctp_strreset_addstrm addstrm; 3720 __u16 size = sizeof(addstrm); 3721 struct sctp_chunk *retval; 3722 3723 retval = sctp_make_reconf(asoc, (!!out + !!in) * size); 3724 if (!retval) 3725 return NULL; 3726 3727 if (out) { 3728 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS; 3729 addstrm.param_hdr.length = htons(size); 3730 addstrm.number_of_streams = htons(out); 3731 addstrm.request_seq = htonl(asoc->strreset_outseq); 3732 addstrm.reserved = 0; 3733 3734 sctp_addto_chunk(retval, size, &addstrm); 3735 } 3736 3737 if (in) { 3738 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS; 3739 addstrm.param_hdr.length = htons(size); 3740 addstrm.number_of_streams = htons(in); 3741 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out); 3742 addstrm.reserved = 0; 3743 3744 sctp_addto_chunk(retval, size, &addstrm); 3745 } 3746 3747 return retval; 3748 } 3749 3750 /* RE-CONFIG 4.4 (RESP) 3751 * 0 1 2 3 3752 * 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 3753 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3754 * | Parameter Type = 16 | Parameter Length | 3755 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3756 * | Re-configuration Response Sequence Number | 3757 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3758 * | Result | 3759 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3760 */ 3761 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc, 3762 __u32 result, __u32 sn) 3763 { 3764 struct sctp_strreset_resp resp; 3765 __u16 length = sizeof(resp); 3766 struct sctp_chunk *retval; 3767 3768 retval = sctp_make_reconf(asoc, length); 3769 if (!retval) 3770 return NULL; 3771 3772 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3773 resp.param_hdr.length = htons(length); 3774 resp.response_seq = htonl(sn); 3775 resp.result = htonl(result); 3776 3777 sctp_addto_chunk(retval, sizeof(resp), &resp); 3778 3779 return retval; 3780 } 3781 3782 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP) 3783 * 0 1 2 3 3784 * 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 3785 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3786 * | Parameter Type = 16 | Parameter Length | 3787 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3788 * | Re-configuration Response Sequence Number | 3789 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3790 * | Result | 3791 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3792 * | Sender's Next TSN (optional) | 3793 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3794 * | Receiver's Next TSN (optional) | 3795 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3796 */ 3797 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc, 3798 __u32 result, __u32 sn, 3799 __u32 sender_tsn, 3800 __u32 receiver_tsn) 3801 { 3802 struct sctp_strreset_resptsn tsnresp; 3803 __u16 length = sizeof(tsnresp); 3804 struct sctp_chunk *retval; 3805 3806 retval = sctp_make_reconf(asoc, length); 3807 if (!retval) 3808 return NULL; 3809 3810 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3811 tsnresp.param_hdr.length = htons(length); 3812 3813 tsnresp.response_seq = htonl(sn); 3814 tsnresp.result = htonl(result); 3815 tsnresp.senders_next_tsn = htonl(sender_tsn); 3816 tsnresp.receivers_next_tsn = htonl(receiver_tsn); 3817 3818 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp); 3819 3820 return retval; 3821 } 3822 3823 bool sctp_verify_reconf(const struct sctp_association *asoc, 3824 struct sctp_chunk *chunk, 3825 struct sctp_paramhdr **errp) 3826 { 3827 struct sctp_reconf_chunk *hdr; 3828 union sctp_params param; 3829 __be16 last = 0; 3830 __u16 cnt = 0; 3831 3832 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; 3833 sctp_walk_params(param, hdr, params) { 3834 __u16 length = ntohs(param.p->length); 3835 3836 *errp = param.p; 3837 if (cnt++ > 2) 3838 return false; 3839 switch (param.p->type) { 3840 case SCTP_PARAM_RESET_OUT_REQUEST: 3841 if (length < sizeof(struct sctp_strreset_outreq) || 3842 (last && last != SCTP_PARAM_RESET_RESPONSE && 3843 last != SCTP_PARAM_RESET_IN_REQUEST)) 3844 return false; 3845 break; 3846 case SCTP_PARAM_RESET_IN_REQUEST: 3847 if (length < sizeof(struct sctp_strreset_inreq) || 3848 (last && last != SCTP_PARAM_RESET_OUT_REQUEST)) 3849 return false; 3850 break; 3851 case SCTP_PARAM_RESET_RESPONSE: 3852 if ((length != sizeof(struct sctp_strreset_resp) && 3853 length != sizeof(struct sctp_strreset_resptsn)) || 3854 (last && last != SCTP_PARAM_RESET_RESPONSE && 3855 last != SCTP_PARAM_RESET_OUT_REQUEST)) 3856 return false; 3857 break; 3858 case SCTP_PARAM_RESET_TSN_REQUEST: 3859 if (length != 3860 sizeof(struct sctp_strreset_tsnreq) || last) 3861 return false; 3862 break; 3863 case SCTP_PARAM_RESET_ADD_IN_STREAMS: 3864 if (length != sizeof(struct sctp_strreset_addstrm) || 3865 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS)) 3866 return false; 3867 break; 3868 case SCTP_PARAM_RESET_ADD_OUT_STREAMS: 3869 if (length != sizeof(struct sctp_strreset_addstrm) || 3870 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS)) 3871 return false; 3872 break; 3873 default: 3874 return false; 3875 } 3876 3877 last = param.p->type; 3878 } 3879 3880 return true; 3881 } 3882