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 struct sctp_chunk *sctp_make_new_encap_port(const struct sctp_association *asoc, 1146 const struct sctp_chunk *chunk) 1147 { 1148 struct sctp_new_encap_port_hdr nep; 1149 struct sctp_chunk *retval; 1150 1151 retval = sctp_make_abort(asoc, chunk, 1152 sizeof(struct sctp_errhdr) + sizeof(nep)); 1153 if (!retval) 1154 goto nodata; 1155 1156 sctp_init_cause(retval, SCTP_ERROR_NEW_ENCAP_PORT, sizeof(nep)); 1157 nep.cur_port = SCTP_INPUT_CB(chunk->skb)->encap_port; 1158 nep.new_port = chunk->transport->encap_port; 1159 sctp_addto_chunk(retval, sizeof(nep), &nep); 1160 1161 nodata: 1162 return retval; 1163 } 1164 1165 /* Make a HEARTBEAT chunk. */ 1166 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1167 const struct sctp_transport *transport) 1168 { 1169 struct sctp_sender_hb_info hbinfo; 1170 struct sctp_chunk *retval; 1171 1172 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, 1173 sizeof(hbinfo), GFP_ATOMIC); 1174 1175 if (!retval) 1176 goto nodata; 1177 1178 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; 1179 hbinfo.param_hdr.length = htons(sizeof(hbinfo)); 1180 hbinfo.daddr = transport->ipaddr; 1181 hbinfo.sent_at = jiffies; 1182 hbinfo.hb_nonce = transport->hb_nonce; 1183 1184 /* Cast away the 'const', as this is just telling the chunk 1185 * what transport it belongs to. 1186 */ 1187 retval->transport = (struct sctp_transport *) transport; 1188 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo), 1189 &hbinfo); 1190 1191 nodata: 1192 return retval; 1193 } 1194 1195 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1196 const struct sctp_chunk *chunk, 1197 const void *payload, 1198 const size_t paylen) 1199 { 1200 struct sctp_chunk *retval; 1201 1202 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen, 1203 GFP_ATOMIC); 1204 if (!retval) 1205 goto nodata; 1206 1207 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1208 1209 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1210 * 1211 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1212 * HEARTBEAT ACK, * etc.) to the same destination transport 1213 * address from which it * received the DATA or control chunk 1214 * to which it is replying. 1215 * 1216 * [HBACK back to where the HEARTBEAT came from.] 1217 */ 1218 if (chunk) 1219 retval->transport = chunk->transport; 1220 1221 nodata: 1222 return retval; 1223 } 1224 1225 /* Create an Operation Error chunk with the specified space reserved. 1226 * This routine can be used for containing multiple causes in the chunk. 1227 */ 1228 static struct sctp_chunk *sctp_make_op_error_space( 1229 const struct sctp_association *asoc, 1230 const struct sctp_chunk *chunk, 1231 size_t size) 1232 { 1233 struct sctp_chunk *retval; 1234 1235 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0, 1236 sizeof(struct sctp_errhdr) + size, 1237 GFP_ATOMIC); 1238 if (!retval) 1239 goto nodata; 1240 1241 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1242 * 1243 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1244 * HEARTBEAT ACK, etc.) to the same destination transport 1245 * address from which it received the DATA or control chunk 1246 * to which it is replying. 1247 * 1248 */ 1249 if (chunk) 1250 retval->transport = chunk->transport; 1251 1252 nodata: 1253 return retval; 1254 } 1255 1256 /* Create an Operation Error chunk of a fixed size, specifically, 1257 * min(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) - overheads. 1258 * This is a helper function to allocate an error chunk for those 1259 * invalid parameter codes in which we may not want to report all the 1260 * errors, if the incoming chunk is large. If it can't fit in a single 1261 * packet, we ignore it. 1262 */ 1263 static inline struct sctp_chunk *sctp_make_op_error_limited( 1264 const struct sctp_association *asoc, 1265 const struct sctp_chunk *chunk) 1266 { 1267 size_t size = SCTP_DEFAULT_MAXSEGMENT; 1268 struct sctp_sock *sp = NULL; 1269 1270 if (asoc) { 1271 size = min_t(size_t, size, asoc->pathmtu); 1272 sp = sctp_sk(asoc->base.sk); 1273 } 1274 1275 size = sctp_mtu_payload(sp, size, sizeof(struct sctp_errhdr)); 1276 1277 return sctp_make_op_error_space(asoc, chunk, size); 1278 } 1279 1280 /* Create an Operation Error chunk. */ 1281 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1282 const struct sctp_chunk *chunk, 1283 __be16 cause_code, const void *payload, 1284 size_t paylen, size_t reserve_tail) 1285 { 1286 struct sctp_chunk *retval; 1287 1288 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); 1289 if (!retval) 1290 goto nodata; 1291 1292 sctp_init_cause(retval, cause_code, paylen + reserve_tail); 1293 sctp_addto_chunk(retval, paylen, payload); 1294 if (reserve_tail) 1295 sctp_addto_param(retval, reserve_tail, NULL); 1296 1297 nodata: 1298 return retval; 1299 } 1300 1301 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc, 1302 __u16 key_id) 1303 { 1304 struct sctp_authhdr auth_hdr; 1305 struct sctp_hmac *hmac_desc; 1306 struct sctp_chunk *retval; 1307 1308 /* Get the first hmac that the peer told us to use */ 1309 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1310 if (unlikely(!hmac_desc)) 1311 return NULL; 1312 1313 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0, 1314 hmac_desc->hmac_len + sizeof(auth_hdr), 1315 GFP_ATOMIC); 1316 if (!retval) 1317 return NULL; 1318 1319 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1320 auth_hdr.shkey_id = htons(key_id); 1321 1322 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr), 1323 &auth_hdr); 1324 1325 skb_put_zero(retval->skb, hmac_desc->hmac_len); 1326 1327 /* Adjust the chunk header to include the empty MAC */ 1328 retval->chunk_hdr->length = 1329 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1330 retval->chunk_end = skb_tail_pointer(retval->skb); 1331 1332 return retval; 1333 } 1334 1335 1336 /******************************************************************** 1337 * 2nd Level Abstractions 1338 ********************************************************************/ 1339 1340 /* Turn an skb into a chunk. 1341 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1342 * 1343 * sctpimpguide-05.txt Section 2.8.2 1344 * M1) Each time a new DATA chunk is transmitted 1345 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1346 * 'TSN.Missing.Report' count will be used to determine missing chunks 1347 * and when to fast retransmit. 1348 * 1349 */ 1350 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1351 const struct sctp_association *asoc, 1352 struct sock *sk, gfp_t gfp) 1353 { 1354 struct sctp_chunk *retval; 1355 1356 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp); 1357 1358 if (!retval) 1359 goto nodata; 1360 if (!sk) 1361 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb); 1362 1363 INIT_LIST_HEAD(&retval->list); 1364 retval->skb = skb; 1365 retval->asoc = (struct sctp_association *)asoc; 1366 retval->singleton = 1; 1367 1368 retval->fast_retransmit = SCTP_CAN_FRTX; 1369 1370 /* Polish the bead hole. */ 1371 INIT_LIST_HEAD(&retval->transmitted_list); 1372 INIT_LIST_HEAD(&retval->frag_list); 1373 SCTP_DBG_OBJCNT_INC(chunk); 1374 refcount_set(&retval->refcnt, 1); 1375 1376 nodata: 1377 return retval; 1378 } 1379 1380 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1381 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1382 union sctp_addr *dest) 1383 { 1384 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1385 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1386 } 1387 1388 /* Extract the source address from a chunk. */ 1389 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1390 { 1391 /* If we have a known transport, use that. */ 1392 if (chunk->transport) { 1393 return &chunk->transport->ipaddr; 1394 } else { 1395 /* Otherwise, extract it from the IP header. */ 1396 return &chunk->source; 1397 } 1398 } 1399 1400 /* Create a new chunk, setting the type and flags headers from the 1401 * arguments, reserving enough space for a 'paylen' byte payload. 1402 */ 1403 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 1404 __u8 type, __u8 flags, int paylen, 1405 gfp_t gfp) 1406 { 1407 struct sctp_chunkhdr *chunk_hdr; 1408 struct sctp_chunk *retval; 1409 struct sk_buff *skb; 1410 struct sock *sk; 1411 int chunklen; 1412 1413 chunklen = SCTP_PAD4(sizeof(*chunk_hdr) + paylen); 1414 if (chunklen > SCTP_MAX_CHUNK_LEN) 1415 goto nodata; 1416 1417 /* No need to allocate LL here, as this is only a chunk. */ 1418 skb = alloc_skb(chunklen, gfp); 1419 if (!skb) 1420 goto nodata; 1421 1422 /* Make room for the chunk header. */ 1423 chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr)); 1424 chunk_hdr->type = type; 1425 chunk_hdr->flags = flags; 1426 chunk_hdr->length = htons(sizeof(*chunk_hdr)); 1427 1428 sk = asoc ? asoc->base.sk : NULL; 1429 retval = sctp_chunkify(skb, asoc, sk, gfp); 1430 if (!retval) { 1431 kfree_skb(skb); 1432 goto nodata; 1433 } 1434 1435 retval->chunk_hdr = chunk_hdr; 1436 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr); 1437 1438 /* Determine if the chunk needs to be authenticated */ 1439 if (sctp_auth_send_cid(type, asoc)) 1440 retval->auth = 1; 1441 1442 return retval; 1443 nodata: 1444 return NULL; 1445 } 1446 1447 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 1448 __u8 flags, int paylen, gfp_t gfp) 1449 { 1450 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp); 1451 } 1452 1453 struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc, 1454 __u8 flags, int paylen, gfp_t gfp) 1455 { 1456 return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp); 1457 } 1458 1459 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 1460 __u8 type, __u8 flags, int paylen, 1461 gfp_t gfp) 1462 { 1463 struct sctp_chunk *chunk; 1464 1465 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp); 1466 if (chunk) 1467 sctp_control_set_owner_w(chunk); 1468 1469 return chunk; 1470 } 1471 1472 /* Release the memory occupied by a chunk. */ 1473 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1474 { 1475 BUG_ON(!list_empty(&chunk->list)); 1476 list_del_init(&chunk->transmitted_list); 1477 1478 consume_skb(chunk->skb); 1479 consume_skb(chunk->auth_chunk); 1480 1481 SCTP_DBG_OBJCNT_DEC(chunk); 1482 kmem_cache_free(sctp_chunk_cachep, chunk); 1483 } 1484 1485 /* Possibly, free the chunk. */ 1486 void sctp_chunk_free(struct sctp_chunk *chunk) 1487 { 1488 /* Release our reference on the message tracker. */ 1489 if (chunk->msg) 1490 sctp_datamsg_put(chunk->msg); 1491 1492 sctp_chunk_put(chunk); 1493 } 1494 1495 /* Grab a reference to the chunk. */ 1496 void sctp_chunk_hold(struct sctp_chunk *ch) 1497 { 1498 refcount_inc(&ch->refcnt); 1499 } 1500 1501 /* Release a reference to the chunk. */ 1502 void sctp_chunk_put(struct sctp_chunk *ch) 1503 { 1504 if (refcount_dec_and_test(&ch->refcnt)) 1505 sctp_chunk_destroy(ch); 1506 } 1507 1508 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1509 * enough. 1510 */ 1511 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1512 { 1513 int chunklen = ntohs(chunk->chunk_hdr->length); 1514 int padlen = SCTP_PAD4(chunklen) - chunklen; 1515 void *target; 1516 1517 skb_put_zero(chunk->skb, padlen); 1518 target = skb_put_data(chunk->skb, data, len); 1519 1520 /* Adjust the chunk length field. */ 1521 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1522 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1523 1524 return target; 1525 } 1526 1527 /* Append bytes from user space to the end of a chunk. Will panic if 1528 * chunk is not big enough. 1529 * Returns a kernel err value. 1530 */ 1531 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len, 1532 struct iov_iter *from) 1533 { 1534 void *target; 1535 1536 /* Make room in chunk for data. */ 1537 target = skb_put(chunk->skb, len); 1538 1539 /* Copy data (whole iovec) into chunk */ 1540 if (!copy_from_iter_full(target, len, from)) 1541 return -EFAULT; 1542 1543 /* Adjust the chunk length field. */ 1544 chunk->chunk_hdr->length = 1545 htons(ntohs(chunk->chunk_hdr->length) + len); 1546 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1547 1548 return 0; 1549 } 1550 1551 /* Helper function to assign a TSN if needed. This assumes that both 1552 * the data_hdr and association have already been assigned. 1553 */ 1554 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1555 { 1556 struct sctp_stream *stream; 1557 struct sctp_chunk *lchunk; 1558 struct sctp_datamsg *msg; 1559 __u16 ssn, sid; 1560 1561 if (chunk->has_ssn) 1562 return; 1563 1564 /* All fragments will be on the same stream */ 1565 sid = ntohs(chunk->subh.data_hdr->stream); 1566 stream = &chunk->asoc->stream; 1567 1568 /* Now assign the sequence number to the entire message. 1569 * All fragments must have the same stream sequence number. 1570 */ 1571 msg = chunk->msg; 1572 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1573 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1574 ssn = 0; 1575 } else { 1576 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1577 ssn = sctp_ssn_next(stream, out, sid); 1578 else 1579 ssn = sctp_ssn_peek(stream, out, sid); 1580 } 1581 1582 lchunk->subh.data_hdr->ssn = htons(ssn); 1583 lchunk->has_ssn = 1; 1584 } 1585 } 1586 1587 /* Helper function to assign a TSN if needed. This assumes that both 1588 * the data_hdr and association have already been assigned. 1589 */ 1590 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1591 { 1592 if (!chunk->has_tsn) { 1593 /* This is the last possible instant to 1594 * assign a TSN. 1595 */ 1596 chunk->subh.data_hdr->tsn = 1597 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1598 chunk->has_tsn = 1; 1599 } 1600 } 1601 1602 /* Create a CLOSED association to use with an incoming packet. */ 1603 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1604 struct sctp_chunk *chunk, 1605 gfp_t gfp) 1606 { 1607 struct sctp_association *asoc; 1608 enum sctp_scope scope; 1609 struct sk_buff *skb; 1610 1611 /* Create the bare association. */ 1612 scope = sctp_scope(sctp_source(chunk)); 1613 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1614 if (!asoc) 1615 goto nodata; 1616 asoc->temp = 1; 1617 skb = chunk->skb; 1618 /* Create an entry for the source address of the packet. */ 1619 SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1); 1620 1621 nodata: 1622 return asoc; 1623 } 1624 1625 /* Build a cookie representing asoc. 1626 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1627 */ 1628 static struct sctp_cookie_param *sctp_pack_cookie( 1629 const struct sctp_endpoint *ep, 1630 const struct sctp_association *asoc, 1631 const struct sctp_chunk *init_chunk, 1632 int *cookie_len, const __u8 *raw_addrs, 1633 int addrs_len) 1634 { 1635 struct sctp_signed_cookie *cookie; 1636 struct sctp_cookie_param *retval; 1637 int headersize, bodysize; 1638 1639 /* Header size is static data prior to the actual cookie, including 1640 * any padding. 1641 */ 1642 headersize = sizeof(struct sctp_paramhdr) + 1643 (sizeof(struct sctp_signed_cookie) - 1644 sizeof(struct sctp_cookie)); 1645 bodysize = sizeof(struct sctp_cookie) 1646 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1647 1648 /* Pad out the cookie to a multiple to make the signature 1649 * functions simpler to write. 1650 */ 1651 if (bodysize % SCTP_COOKIE_MULTIPLE) 1652 bodysize += SCTP_COOKIE_MULTIPLE 1653 - (bodysize % SCTP_COOKIE_MULTIPLE); 1654 *cookie_len = headersize + bodysize; 1655 1656 /* Clear this memory since we are sending this data structure 1657 * out on the network. 1658 */ 1659 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1660 if (!retval) 1661 goto nodata; 1662 1663 cookie = (struct sctp_signed_cookie *) retval->body; 1664 1665 /* Set up the parameter header. */ 1666 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1667 retval->p.length = htons(*cookie_len); 1668 1669 /* Copy the cookie part of the association itself. */ 1670 cookie->c = asoc->c; 1671 /* Save the raw address list length in the cookie. */ 1672 cookie->c.raw_addr_list_len = addrs_len; 1673 1674 /* Remember PR-SCTP capability. */ 1675 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1676 1677 /* Save adaptation indication in the cookie. */ 1678 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1679 1680 /* Set an expiration time for the cookie. */ 1681 cookie->c.expiration = ktime_add(asoc->cookie_life, 1682 ktime_get_real()); 1683 1684 /* Copy the peer's init packet. */ 1685 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr, 1686 ntohs(init_chunk->chunk_hdr->length)); 1687 1688 /* Copy the raw local address list of the association. */ 1689 memcpy((__u8 *)&cookie->c.peer_init[0] + 1690 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1691 1692 if (sctp_sk(ep->base.sk)->hmac) { 1693 struct crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac; 1694 int err; 1695 1696 /* Sign the message. */ 1697 err = crypto_shash_setkey(tfm, ep->secret_key, 1698 sizeof(ep->secret_key)) ?: 1699 crypto_shash_tfm_digest(tfm, (u8 *)&cookie->c, bodysize, 1700 cookie->signature); 1701 if (err) 1702 goto free_cookie; 1703 } 1704 1705 return retval; 1706 1707 free_cookie: 1708 kfree(retval); 1709 nodata: 1710 *cookie_len = 0; 1711 return NULL; 1712 } 1713 1714 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1715 struct sctp_association *sctp_unpack_cookie( 1716 const struct sctp_endpoint *ep, 1717 const struct sctp_association *asoc, 1718 struct sctp_chunk *chunk, gfp_t gfp, 1719 int *error, struct sctp_chunk **errp) 1720 { 1721 struct sctp_association *retval = NULL; 1722 int headersize, bodysize, fixed_size; 1723 struct sctp_signed_cookie *cookie; 1724 struct sk_buff *skb = chunk->skb; 1725 struct sctp_cookie *bear_cookie; 1726 __u8 *digest = ep->digest; 1727 enum sctp_scope scope; 1728 unsigned int len; 1729 ktime_t kt; 1730 1731 /* Header size is static data prior to the actual cookie, including 1732 * any padding. 1733 */ 1734 headersize = sizeof(struct sctp_chunkhdr) + 1735 (sizeof(struct sctp_signed_cookie) - 1736 sizeof(struct sctp_cookie)); 1737 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1738 fixed_size = headersize + sizeof(struct sctp_cookie); 1739 1740 /* Verify that the chunk looks like it even has a cookie. 1741 * There must be enough room for our cookie and our peer's 1742 * INIT chunk. 1743 */ 1744 len = ntohs(chunk->chunk_hdr->length); 1745 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1746 goto malformed; 1747 1748 /* Verify that the cookie has been padded out. */ 1749 if (bodysize % SCTP_COOKIE_MULTIPLE) 1750 goto malformed; 1751 1752 /* Process the cookie. */ 1753 cookie = chunk->subh.cookie_hdr; 1754 bear_cookie = &cookie->c; 1755 1756 if (!sctp_sk(ep->base.sk)->hmac) 1757 goto no_hmac; 1758 1759 /* Check the signature. */ 1760 { 1761 struct crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac; 1762 int err; 1763 1764 err = crypto_shash_setkey(tfm, ep->secret_key, 1765 sizeof(ep->secret_key)) ?: 1766 crypto_shash_tfm_digest(tfm, (u8 *)bear_cookie, bodysize, 1767 digest); 1768 if (err) { 1769 *error = -SCTP_IERROR_NOMEM; 1770 goto fail; 1771 } 1772 } 1773 1774 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1775 *error = -SCTP_IERROR_BAD_SIG; 1776 goto fail; 1777 } 1778 1779 no_hmac: 1780 /* IG Section 2.35.2: 1781 * 3) Compare the port numbers and the verification tag contained 1782 * within the COOKIE ECHO chunk to the actual port numbers and the 1783 * verification tag within the SCTP common header of the received 1784 * packet. If these values do not match the packet MUST be silently 1785 * discarded, 1786 */ 1787 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1788 *error = -SCTP_IERROR_BAD_TAG; 1789 goto fail; 1790 } 1791 1792 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1793 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1794 *error = -SCTP_IERROR_BAD_PORTS; 1795 goto fail; 1796 } 1797 1798 /* Check to see if the cookie is stale. If there is already 1799 * an association, there is no need to check cookie's expiration 1800 * for init collision case of lost COOKIE ACK. 1801 * If skb has been timestamped, then use the stamp, otherwise 1802 * use current time. This introduces a small possibility that 1803 * a cookie may be considered expired, but this would only slow 1804 * down the new association establishment instead of every packet. 1805 */ 1806 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1807 kt = skb_get_ktime(skb); 1808 else 1809 kt = ktime_get_real(); 1810 1811 if (!asoc && ktime_before(bear_cookie->expiration, kt)) { 1812 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); 1813 __be32 n = htonl(usecs); 1814 1815 /* 1816 * Section 3.3.10.3 Stale Cookie Error (3) 1817 * 1818 * Cause of error 1819 * --------------- 1820 * Stale Cookie Error: Indicates the receipt of a valid State 1821 * Cookie that has expired. 1822 */ 1823 *errp = sctp_make_op_error(asoc, chunk, 1824 SCTP_ERROR_STALE_COOKIE, &n, 1825 sizeof(n), 0); 1826 if (*errp) 1827 *error = -SCTP_IERROR_STALE_COOKIE; 1828 else 1829 *error = -SCTP_IERROR_NOMEM; 1830 1831 goto fail; 1832 } 1833 1834 /* Make a new base association. */ 1835 scope = sctp_scope(sctp_source(chunk)); 1836 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1837 if (!retval) { 1838 *error = -SCTP_IERROR_NOMEM; 1839 goto fail; 1840 } 1841 1842 /* Set up our peer's port number. */ 1843 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1844 1845 /* Populate the association from the cookie. */ 1846 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1847 1848 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1849 GFP_ATOMIC) < 0) { 1850 *error = -SCTP_IERROR_NOMEM; 1851 goto fail; 1852 } 1853 1854 /* Also, add the destination address. */ 1855 if (list_empty(&retval->base.bind_addr.address_list)) { 1856 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1857 sizeof(chunk->dest), SCTP_ADDR_SRC, 1858 GFP_ATOMIC); 1859 } 1860 1861 retval->next_tsn = retval->c.initial_tsn; 1862 retval->ctsn_ack_point = retval->next_tsn - 1; 1863 retval->addip_serial = retval->c.initial_tsn; 1864 retval->strreset_outseq = retval->c.initial_tsn; 1865 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1866 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1867 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1868 1869 /* The INIT stuff will be done by the side effects. */ 1870 return retval; 1871 1872 fail: 1873 if (retval) 1874 sctp_association_free(retval); 1875 1876 return NULL; 1877 1878 malformed: 1879 /* Yikes! The packet is either corrupt or deliberately 1880 * malformed. 1881 */ 1882 *error = -SCTP_IERROR_MALFORMED; 1883 goto fail; 1884 } 1885 1886 /******************************************************************** 1887 * 3rd Level Abstractions 1888 ********************************************************************/ 1889 1890 struct __sctp_missing { 1891 __be32 num_missing; 1892 __be16 type; 1893 } __packed; 1894 1895 /* 1896 * Report a missing mandatory parameter. 1897 */ 1898 static int sctp_process_missing_param(const struct sctp_association *asoc, 1899 enum sctp_param paramtype, 1900 struct sctp_chunk *chunk, 1901 struct sctp_chunk **errp) 1902 { 1903 struct __sctp_missing report; 1904 __u16 len; 1905 1906 len = SCTP_PAD4(sizeof(report)); 1907 1908 /* Make an ERROR chunk, preparing enough room for 1909 * returning multiple unknown parameters. 1910 */ 1911 if (!*errp) 1912 *errp = sctp_make_op_error_space(asoc, chunk, len); 1913 1914 if (*errp) { 1915 report.num_missing = htonl(1); 1916 report.type = paramtype; 1917 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1918 sizeof(report)); 1919 sctp_addto_chunk(*errp, sizeof(report), &report); 1920 } 1921 1922 /* Stop processing this chunk. */ 1923 return 0; 1924 } 1925 1926 /* Report an Invalid Mandatory Parameter. */ 1927 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1928 struct sctp_chunk *chunk, 1929 struct sctp_chunk **errp) 1930 { 1931 /* Invalid Mandatory Parameter Error has no payload. */ 1932 1933 if (!*errp) 1934 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1935 1936 if (*errp) 1937 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1938 1939 /* Stop processing this chunk. */ 1940 return 0; 1941 } 1942 1943 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1944 struct sctp_paramhdr *param, 1945 const struct sctp_chunk *chunk, 1946 struct sctp_chunk **errp) 1947 { 1948 /* This is a fatal error. Any accumulated non-fatal errors are 1949 * not reported. 1950 */ 1951 if (*errp) 1952 sctp_chunk_free(*errp); 1953 1954 /* Create an error chunk and fill it in with our payload. */ 1955 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1956 1957 return 0; 1958 } 1959 1960 1961 /* Do not attempt to handle the HOST_NAME parm. However, do 1962 * send back an indicator to the peer. 1963 */ 1964 static int sctp_process_hn_param(const struct sctp_association *asoc, 1965 union sctp_params param, 1966 struct sctp_chunk *chunk, 1967 struct sctp_chunk **errp) 1968 { 1969 __u16 len = ntohs(param.p->length); 1970 1971 /* Processing of the HOST_NAME parameter will generate an 1972 * ABORT. If we've accumulated any non-fatal errors, they 1973 * would be unrecognized parameters and we should not include 1974 * them in the ABORT. 1975 */ 1976 if (*errp) 1977 sctp_chunk_free(*errp); 1978 1979 *errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_DNS_FAILED, 1980 param.v, len, 0); 1981 1982 /* Stop processing this chunk. */ 1983 return 0; 1984 } 1985 1986 static int sctp_verify_ext_param(struct net *net, 1987 const struct sctp_endpoint *ep, 1988 union sctp_params param) 1989 { 1990 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 1991 int have_asconf = 0; 1992 int have_auth = 0; 1993 int i; 1994 1995 for (i = 0; i < num_ext; i++) { 1996 switch (param.ext->chunks[i]) { 1997 case SCTP_CID_AUTH: 1998 have_auth = 1; 1999 break; 2000 case SCTP_CID_ASCONF: 2001 case SCTP_CID_ASCONF_ACK: 2002 have_asconf = 1; 2003 break; 2004 } 2005 } 2006 2007 /* ADD-IP Security: The draft requires us to ABORT or ignore the 2008 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 2009 * only if ADD-IP is turned on and we are not backward-compatible 2010 * mode. 2011 */ 2012 if (net->sctp.addip_noauth) 2013 return 1; 2014 2015 if (ep->asconf_enable && !have_auth && have_asconf) 2016 return 0; 2017 2018 return 1; 2019 } 2020 2021 static void sctp_process_ext_param(struct sctp_association *asoc, 2022 union sctp_params param) 2023 { 2024 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2025 int i; 2026 2027 for (i = 0; i < num_ext; i++) { 2028 switch (param.ext->chunks[i]) { 2029 case SCTP_CID_RECONF: 2030 if (asoc->ep->reconf_enable) 2031 asoc->peer.reconf_capable = 1; 2032 break; 2033 case SCTP_CID_FWD_TSN: 2034 if (asoc->ep->prsctp_enable) 2035 asoc->peer.prsctp_capable = 1; 2036 break; 2037 case SCTP_CID_AUTH: 2038 /* if the peer reports AUTH, assume that he 2039 * supports AUTH. 2040 */ 2041 if (asoc->ep->auth_enable) 2042 asoc->peer.auth_capable = 1; 2043 break; 2044 case SCTP_CID_ASCONF: 2045 case SCTP_CID_ASCONF_ACK: 2046 if (asoc->ep->asconf_enable) 2047 asoc->peer.asconf_capable = 1; 2048 break; 2049 case SCTP_CID_I_DATA: 2050 if (asoc->ep->intl_enable) 2051 asoc->peer.intl_capable = 1; 2052 break; 2053 default: 2054 break; 2055 } 2056 } 2057 } 2058 2059 /* RFC 3.2.1 & the Implementers Guide 2.2. 2060 * 2061 * The Parameter Types are encoded such that the 2062 * highest-order two bits specify the action that must be 2063 * taken if the processing endpoint does not recognize the 2064 * Parameter Type. 2065 * 2066 * 00 - Stop processing this parameter; do not process any further 2067 * parameters within this chunk 2068 * 2069 * 01 - Stop processing this parameter, do not process any further 2070 * parameters within this chunk, and report the unrecognized 2071 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2072 * 2073 * 10 - Skip this parameter and continue processing. 2074 * 2075 * 11 - Skip this parameter and continue processing but 2076 * report the unrecognized parameter in an 2077 * 'Unrecognized Parameter' ERROR chunk. 2078 * 2079 * Return value: 2080 * SCTP_IERROR_NO_ERROR - continue with the chunk 2081 * SCTP_IERROR_ERROR - stop and report an error. 2082 * SCTP_IERROR_NOMEME - out of memory. 2083 */ 2084 static enum sctp_ierror sctp_process_unk_param( 2085 const struct sctp_association *asoc, 2086 union sctp_params param, 2087 struct sctp_chunk *chunk, 2088 struct sctp_chunk **errp) 2089 { 2090 int retval = SCTP_IERROR_NO_ERROR; 2091 2092 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2093 case SCTP_PARAM_ACTION_DISCARD: 2094 retval = SCTP_IERROR_ERROR; 2095 break; 2096 case SCTP_PARAM_ACTION_SKIP: 2097 break; 2098 case SCTP_PARAM_ACTION_DISCARD_ERR: 2099 retval = SCTP_IERROR_ERROR; 2100 fallthrough; 2101 case SCTP_PARAM_ACTION_SKIP_ERR: 2102 /* Make an ERROR chunk, preparing enough room for 2103 * returning multiple unknown parameters. 2104 */ 2105 if (!*errp) { 2106 *errp = sctp_make_op_error_limited(asoc, chunk); 2107 if (!*errp) { 2108 /* If there is no memory for generating the 2109 * ERROR report as specified, an ABORT will be 2110 * triggered to the peer and the association 2111 * won't be established. 2112 */ 2113 retval = SCTP_IERROR_NOMEM; 2114 break; 2115 } 2116 } 2117 2118 if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2119 ntohs(param.p->length))) 2120 sctp_addto_chunk(*errp, ntohs(param.p->length), 2121 param.v); 2122 break; 2123 default: 2124 break; 2125 } 2126 2127 return retval; 2128 } 2129 2130 /* Verify variable length parameters 2131 * Return values: 2132 * SCTP_IERROR_ABORT - trigger an ABORT 2133 * SCTP_IERROR_NOMEM - out of memory (abort) 2134 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2135 * SCTP_IERROR_NO_ERROR - continue with the chunk 2136 */ 2137 static enum sctp_ierror sctp_verify_param(struct net *net, 2138 const struct sctp_endpoint *ep, 2139 const struct sctp_association *asoc, 2140 union sctp_params param, 2141 enum sctp_cid cid, 2142 struct sctp_chunk *chunk, 2143 struct sctp_chunk **err_chunk) 2144 { 2145 struct sctp_hmac_algo_param *hmacs; 2146 int retval = SCTP_IERROR_NO_ERROR; 2147 __u16 n_elt, id = 0; 2148 int i; 2149 2150 /* FIXME - This routine is not looking at each parameter per the 2151 * chunk type, i.e., unrecognized parameters should be further 2152 * identified based on the chunk id. 2153 */ 2154 2155 switch (param.p->type) { 2156 case SCTP_PARAM_IPV4_ADDRESS: 2157 case SCTP_PARAM_IPV6_ADDRESS: 2158 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2159 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2160 case SCTP_PARAM_STATE_COOKIE: 2161 case SCTP_PARAM_HEARTBEAT_INFO: 2162 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2163 case SCTP_PARAM_ECN_CAPABLE: 2164 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2165 break; 2166 2167 case SCTP_PARAM_SUPPORTED_EXT: 2168 if (!sctp_verify_ext_param(net, ep, param)) 2169 return SCTP_IERROR_ABORT; 2170 break; 2171 2172 case SCTP_PARAM_SET_PRIMARY: 2173 if (ep->asconf_enable) 2174 break; 2175 goto unhandled; 2176 2177 case SCTP_PARAM_HOST_NAME_ADDRESS: 2178 /* Tell the peer, we won't support this param. */ 2179 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2180 retval = SCTP_IERROR_ABORT; 2181 break; 2182 2183 case SCTP_PARAM_FWD_TSN_SUPPORT: 2184 if (ep->prsctp_enable) 2185 break; 2186 goto unhandled; 2187 2188 case SCTP_PARAM_RANDOM: 2189 if (!ep->auth_enable) 2190 goto unhandled; 2191 2192 /* SCTP-AUTH: Secion 6.1 2193 * If the random number is not 32 byte long the association 2194 * MUST be aborted. The ABORT chunk SHOULD contain the error 2195 * cause 'Protocol Violation'. 2196 */ 2197 if (SCTP_AUTH_RANDOM_LENGTH != ntohs(param.p->length) - 2198 sizeof(struct sctp_paramhdr)) { 2199 sctp_process_inv_paramlength(asoc, param.p, 2200 chunk, err_chunk); 2201 retval = SCTP_IERROR_ABORT; 2202 } 2203 break; 2204 2205 case SCTP_PARAM_CHUNKS: 2206 if (!ep->auth_enable) 2207 goto unhandled; 2208 2209 /* SCTP-AUTH: Section 3.2 2210 * The CHUNKS parameter MUST be included once in the INIT or 2211 * INIT-ACK chunk if the sender wants to receive authenticated 2212 * chunks. Its maximum length is 260 bytes. 2213 */ 2214 if (260 < ntohs(param.p->length)) { 2215 sctp_process_inv_paramlength(asoc, param.p, 2216 chunk, err_chunk); 2217 retval = SCTP_IERROR_ABORT; 2218 } 2219 break; 2220 2221 case SCTP_PARAM_HMAC_ALGO: 2222 if (!ep->auth_enable) 2223 goto unhandled; 2224 2225 hmacs = (struct sctp_hmac_algo_param *)param.p; 2226 n_elt = (ntohs(param.p->length) - 2227 sizeof(struct sctp_paramhdr)) >> 1; 2228 2229 /* SCTP-AUTH: Section 6.1 2230 * The HMAC algorithm based on SHA-1 MUST be supported and 2231 * included in the HMAC-ALGO parameter. 2232 */ 2233 for (i = 0; i < n_elt; i++) { 2234 id = ntohs(hmacs->hmac_ids[i]); 2235 2236 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2237 break; 2238 } 2239 2240 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2241 sctp_process_inv_paramlength(asoc, param.p, chunk, 2242 err_chunk); 2243 retval = SCTP_IERROR_ABORT; 2244 } 2245 break; 2246 unhandled: 2247 default: 2248 pr_debug("%s: unrecognized param:%d for chunk:%d\n", 2249 __func__, ntohs(param.p->type), cid); 2250 2251 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2252 break; 2253 } 2254 return retval; 2255 } 2256 2257 /* Verify the INIT packet before we process it. */ 2258 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 2259 const struct sctp_association *asoc, enum sctp_cid cid, 2260 struct sctp_init_chunk *peer_init, 2261 struct sctp_chunk *chunk, struct sctp_chunk **errp) 2262 { 2263 union sctp_params param; 2264 bool has_cookie = false; 2265 int result; 2266 2267 /* Check for missing mandatory parameters. Note: Initial TSN is 2268 * also mandatory, but is not checked here since the valid range 2269 * is 0..2**32-1. RFC4960, section 3.3.3. 2270 */ 2271 if (peer_init->init_hdr.num_outbound_streams == 0 || 2272 peer_init->init_hdr.num_inbound_streams == 0 || 2273 peer_init->init_hdr.init_tag == 0 || 2274 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) 2275 return sctp_process_inv_mandatory(asoc, chunk, errp); 2276 2277 sctp_walk_params(param, peer_init, init_hdr.params) { 2278 if (param.p->type == SCTP_PARAM_STATE_COOKIE) 2279 has_cookie = true; 2280 } 2281 2282 /* There is a possibility that a parameter length was bad and 2283 * in that case we would have stoped walking the parameters. 2284 * The current param.p would point at the bad one. 2285 * Current consensus on the mailing list is to generate a PROTOCOL 2286 * VIOLATION error. We build the ERROR chunk here and let the normal 2287 * error handling code build and send the packet. 2288 */ 2289 if (param.v != (void *)chunk->chunk_end) 2290 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2291 2292 /* The only missing mandatory param possible today is 2293 * the state cookie for an INIT-ACK chunk. 2294 */ 2295 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2296 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2297 chunk, errp); 2298 2299 /* Verify all the variable length parameters */ 2300 sctp_walk_params(param, peer_init, init_hdr.params) { 2301 result = sctp_verify_param(net, ep, asoc, param, cid, 2302 chunk, errp); 2303 switch (result) { 2304 case SCTP_IERROR_ABORT: 2305 case SCTP_IERROR_NOMEM: 2306 return 0; 2307 case SCTP_IERROR_ERROR: 2308 return 1; 2309 case SCTP_IERROR_NO_ERROR: 2310 default: 2311 break; 2312 } 2313 2314 } /* for (loop through all parameters) */ 2315 2316 return 1; 2317 } 2318 2319 /* Unpack the parameters in an INIT packet into an association. 2320 * Returns 0 on failure, else success. 2321 * FIXME: This is an association method. 2322 */ 2323 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2324 const union sctp_addr *peer_addr, 2325 struct sctp_init_chunk *peer_init, gfp_t gfp) 2326 { 2327 struct sctp_transport *transport; 2328 struct list_head *pos, *temp; 2329 union sctp_params param; 2330 union sctp_addr addr; 2331 struct sctp_af *af; 2332 int src_match = 0; 2333 2334 /* We must include the address that the INIT packet came from. 2335 * This is the only address that matters for an INIT packet. 2336 * When processing a COOKIE ECHO, we retrieve the from address 2337 * of the INIT from the cookie. 2338 */ 2339 2340 /* This implementation defaults to making the first transport 2341 * added as the primary transport. The source address seems to 2342 * be a better choice than any of the embedded addresses. 2343 */ 2344 asoc->encap_port = SCTP_INPUT_CB(chunk->skb)->encap_port; 2345 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2346 goto nomem; 2347 2348 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2349 src_match = 1; 2350 2351 /* Process the initialization parameters. */ 2352 sctp_walk_params(param, peer_init, init_hdr.params) { 2353 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2354 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2355 af = sctp_get_af_specific(param_type2af(param.p->type)); 2356 af->from_addr_param(&addr, param.addr, 2357 chunk->sctp_hdr->source, 0); 2358 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2359 src_match = 1; 2360 } 2361 2362 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2363 goto clean_up; 2364 } 2365 2366 /* source address of chunk may not match any valid address */ 2367 if (!src_match) 2368 goto clean_up; 2369 2370 /* AUTH: After processing the parameters, make sure that we 2371 * have all the required info to potentially do authentications. 2372 */ 2373 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2374 !asoc->peer.peer_hmacs)) 2375 asoc->peer.auth_capable = 0; 2376 2377 /* In a non-backward compatible mode, if the peer claims 2378 * support for ADD-IP but not AUTH, the ADD-IP spec states 2379 * that we MUST ABORT the association. Section 6. The section 2380 * also give us an option to silently ignore the packet, which 2381 * is what we'll do here. 2382 */ 2383 if (!asoc->base.net->sctp.addip_noauth && 2384 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2385 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2386 SCTP_PARAM_DEL_IP | 2387 SCTP_PARAM_SET_PRIMARY); 2388 asoc->peer.asconf_capable = 0; 2389 goto clean_up; 2390 } 2391 2392 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2393 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2394 transport = list_entry(pos, struct sctp_transport, transports); 2395 if (transport->state == SCTP_UNKNOWN) { 2396 sctp_assoc_rm_peer(asoc, transport); 2397 } 2398 } 2399 2400 /* The fixed INIT headers are always in network byte 2401 * order. 2402 */ 2403 asoc->peer.i.init_tag = 2404 ntohl(peer_init->init_hdr.init_tag); 2405 asoc->peer.i.a_rwnd = 2406 ntohl(peer_init->init_hdr.a_rwnd); 2407 asoc->peer.i.num_outbound_streams = 2408 ntohs(peer_init->init_hdr.num_outbound_streams); 2409 asoc->peer.i.num_inbound_streams = 2410 ntohs(peer_init->init_hdr.num_inbound_streams); 2411 asoc->peer.i.initial_tsn = 2412 ntohl(peer_init->init_hdr.initial_tsn); 2413 2414 asoc->strreset_inseq = asoc->peer.i.initial_tsn; 2415 2416 /* Apply the upper bounds for output streams based on peer's 2417 * number of inbound streams. 2418 */ 2419 if (asoc->c.sinit_num_ostreams > 2420 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2421 asoc->c.sinit_num_ostreams = 2422 ntohs(peer_init->init_hdr.num_inbound_streams); 2423 } 2424 2425 if (asoc->c.sinit_max_instreams > 2426 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2427 asoc->c.sinit_max_instreams = 2428 ntohs(peer_init->init_hdr.num_outbound_streams); 2429 } 2430 2431 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2432 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2433 2434 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2435 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2436 2437 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2438 * high (for example, implementations MAY use the size of the receiver 2439 * advertised window). 2440 */ 2441 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2442 transports) { 2443 transport->ssthresh = asoc->peer.i.a_rwnd; 2444 } 2445 2446 /* Set up the TSN tracking pieces. */ 2447 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2448 asoc->peer.i.initial_tsn, gfp)) 2449 goto clean_up; 2450 2451 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2452 * 2453 * The stream sequence number in all the streams shall start 2454 * from 0 when the association is established. Also, when the 2455 * stream sequence number reaches the value 65535 the next 2456 * stream sequence number shall be set to 0. 2457 */ 2458 2459 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams, 2460 asoc->c.sinit_max_instreams, gfp)) 2461 goto clean_up; 2462 2463 /* Update frag_point when stream_interleave may get changed. */ 2464 sctp_assoc_update_frag_point(asoc); 2465 2466 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp)) 2467 goto clean_up; 2468 2469 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2470 * 2471 * When an endpoint has an ASCONF signaled change to be sent to the 2472 * remote endpoint it should do the following: 2473 * ... 2474 * A2) A serial number should be assigned to the Chunk. The serial 2475 * number should be a monotonically increasing number. All serial 2476 * numbers are defined to be initialized at the start of the 2477 * association to the same value as the Initial TSN. 2478 */ 2479 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2480 return 1; 2481 2482 clean_up: 2483 /* Release the transport structures. */ 2484 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2485 transport = list_entry(pos, struct sctp_transport, transports); 2486 if (transport->state != SCTP_ACTIVE) 2487 sctp_assoc_rm_peer(asoc, transport); 2488 } 2489 2490 nomem: 2491 return 0; 2492 } 2493 2494 2495 /* Update asoc with the option described in param. 2496 * 2497 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2498 * 2499 * asoc is the association to update. 2500 * param is the variable length parameter to use for update. 2501 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2502 * If the current packet is an INIT we want to minimize the amount of 2503 * work we do. In particular, we should not build transport 2504 * structures for the addresses. 2505 */ 2506 static int sctp_process_param(struct sctp_association *asoc, 2507 union sctp_params param, 2508 const union sctp_addr *peer_addr, 2509 gfp_t gfp) 2510 { 2511 struct sctp_endpoint *ep = asoc->ep; 2512 union sctp_addr_param *addr_param; 2513 struct net *net = asoc->base.net; 2514 struct sctp_transport *t; 2515 enum sctp_scope scope; 2516 union sctp_addr addr; 2517 struct sctp_af *af; 2518 int retval = 1, i; 2519 u32 stale; 2520 __u16 sat; 2521 2522 /* We maintain all INIT parameters in network byte order all the 2523 * time. This allows us to not worry about whether the parameters 2524 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2525 */ 2526 switch (param.p->type) { 2527 case SCTP_PARAM_IPV6_ADDRESS: 2528 if (PF_INET6 != asoc->base.sk->sk_family) 2529 break; 2530 goto do_addr_param; 2531 2532 case SCTP_PARAM_IPV4_ADDRESS: 2533 /* v4 addresses are not allowed on v6-only socket */ 2534 if (ipv6_only_sock(asoc->base.sk)) 2535 break; 2536 do_addr_param: 2537 af = sctp_get_af_specific(param_type2af(param.p->type)); 2538 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); 2539 scope = sctp_scope(peer_addr); 2540 if (sctp_in_scope(net, &addr, scope)) 2541 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2542 return 0; 2543 break; 2544 2545 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2546 if (!net->sctp.cookie_preserve_enable) 2547 break; 2548 2549 stale = ntohl(param.life->lifespan_increment); 2550 2551 /* Suggested Cookie Life span increment's unit is msec, 2552 * (1/1000sec). 2553 */ 2554 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale); 2555 break; 2556 2557 case SCTP_PARAM_HOST_NAME_ADDRESS: 2558 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__); 2559 break; 2560 2561 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2562 /* Turn off the default values first so we'll know which 2563 * ones are really set by the peer. 2564 */ 2565 asoc->peer.ipv4_address = 0; 2566 asoc->peer.ipv6_address = 0; 2567 2568 /* Assume that peer supports the address family 2569 * by which it sends a packet. 2570 */ 2571 if (peer_addr->sa.sa_family == AF_INET6) 2572 asoc->peer.ipv6_address = 1; 2573 else if (peer_addr->sa.sa_family == AF_INET) 2574 asoc->peer.ipv4_address = 1; 2575 2576 /* Cycle through address types; avoid divide by 0. */ 2577 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2578 if (sat) 2579 sat /= sizeof(__u16); 2580 2581 for (i = 0; i < sat; ++i) { 2582 switch (param.sat->types[i]) { 2583 case SCTP_PARAM_IPV4_ADDRESS: 2584 asoc->peer.ipv4_address = 1; 2585 break; 2586 2587 case SCTP_PARAM_IPV6_ADDRESS: 2588 if (PF_INET6 == asoc->base.sk->sk_family) 2589 asoc->peer.ipv6_address = 1; 2590 break; 2591 2592 case SCTP_PARAM_HOST_NAME_ADDRESS: 2593 asoc->peer.hostname_address = 1; 2594 break; 2595 2596 default: /* Just ignore anything else. */ 2597 break; 2598 } 2599 } 2600 break; 2601 2602 case SCTP_PARAM_STATE_COOKIE: 2603 asoc->peer.cookie_len = 2604 ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2605 kfree(asoc->peer.cookie); 2606 asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp); 2607 if (!asoc->peer.cookie) 2608 retval = 0; 2609 break; 2610 2611 case SCTP_PARAM_HEARTBEAT_INFO: 2612 /* Would be odd to receive, but it causes no problems. */ 2613 break; 2614 2615 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2616 /* Rejected during verify stage. */ 2617 break; 2618 2619 case SCTP_PARAM_ECN_CAPABLE: 2620 if (asoc->ep->ecn_enable) { 2621 asoc->peer.ecn_capable = 1; 2622 break; 2623 } 2624 /* Fall Through */ 2625 goto fall_through; 2626 2627 2628 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2629 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2630 break; 2631 2632 case SCTP_PARAM_SET_PRIMARY: 2633 if (!ep->asconf_enable) 2634 goto fall_through; 2635 2636 addr_param = param.v + sizeof(struct sctp_addip_param); 2637 2638 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 2639 if (af == NULL) 2640 break; 2641 2642 af->from_addr_param(&addr, addr_param, 2643 htons(asoc->peer.port), 0); 2644 2645 /* if the address is invalid, we can't process it. 2646 * XXX: see spec for what to do. 2647 */ 2648 if (!af->addr_valid(&addr, NULL, NULL)) 2649 break; 2650 2651 t = sctp_assoc_lookup_paddr(asoc, &addr); 2652 if (!t) 2653 break; 2654 2655 sctp_assoc_set_primary(asoc, t); 2656 break; 2657 2658 case SCTP_PARAM_SUPPORTED_EXT: 2659 sctp_process_ext_param(asoc, param); 2660 break; 2661 2662 case SCTP_PARAM_FWD_TSN_SUPPORT: 2663 if (asoc->ep->prsctp_enable) { 2664 asoc->peer.prsctp_capable = 1; 2665 break; 2666 } 2667 /* Fall Through */ 2668 goto fall_through; 2669 2670 case SCTP_PARAM_RANDOM: 2671 if (!ep->auth_enable) 2672 goto fall_through; 2673 2674 /* Save peer's random parameter */ 2675 kfree(asoc->peer.peer_random); 2676 asoc->peer.peer_random = kmemdup(param.p, 2677 ntohs(param.p->length), gfp); 2678 if (!asoc->peer.peer_random) { 2679 retval = 0; 2680 break; 2681 } 2682 break; 2683 2684 case SCTP_PARAM_HMAC_ALGO: 2685 if (!ep->auth_enable) 2686 goto fall_through; 2687 2688 /* Save peer's HMAC list */ 2689 kfree(asoc->peer.peer_hmacs); 2690 asoc->peer.peer_hmacs = kmemdup(param.p, 2691 ntohs(param.p->length), gfp); 2692 if (!asoc->peer.peer_hmacs) { 2693 retval = 0; 2694 break; 2695 } 2696 2697 /* Set the default HMAC the peer requested*/ 2698 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2699 break; 2700 2701 case SCTP_PARAM_CHUNKS: 2702 if (!ep->auth_enable) 2703 goto fall_through; 2704 2705 kfree(asoc->peer.peer_chunks); 2706 asoc->peer.peer_chunks = kmemdup(param.p, 2707 ntohs(param.p->length), gfp); 2708 if (!asoc->peer.peer_chunks) 2709 retval = 0; 2710 break; 2711 fall_through: 2712 default: 2713 /* Any unrecognized parameters should have been caught 2714 * and handled by sctp_verify_param() which should be 2715 * called prior to this routine. Simply log the error 2716 * here. 2717 */ 2718 pr_debug("%s: ignoring param:%d for association:%p.\n", 2719 __func__, ntohs(param.p->type), asoc); 2720 break; 2721 } 2722 2723 return retval; 2724 } 2725 2726 /* Select a new verification tag. */ 2727 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2728 { 2729 /* I believe that this random number generator complies with RFC1750. 2730 * A tag of 0 is reserved for special cases (e.g. INIT). 2731 */ 2732 __u32 x; 2733 2734 do { 2735 get_random_bytes(&x, sizeof(__u32)); 2736 } while (x == 0); 2737 2738 return x; 2739 } 2740 2741 /* Select an initial TSN to send during startup. */ 2742 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2743 { 2744 __u32 retval; 2745 2746 get_random_bytes(&retval, sizeof(__u32)); 2747 return retval; 2748 } 2749 2750 /* 2751 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2752 * 0 1 2 3 2753 * 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 2754 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2755 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2756 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2757 * | Serial Number | 2758 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2759 * | Address Parameter | 2760 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2761 * | ASCONF Parameter #1 | 2762 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2763 * \ \ 2764 * / .... / 2765 * \ \ 2766 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2767 * | ASCONF Parameter #N | 2768 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2769 * 2770 * Address Parameter and other parameter will not be wrapped in this function 2771 */ 2772 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2773 union sctp_addr *addr, 2774 int vparam_len) 2775 { 2776 struct sctp_addiphdr asconf; 2777 struct sctp_chunk *retval; 2778 int length = sizeof(asconf) + vparam_len; 2779 union sctp_addr_param addrparam; 2780 int addrlen; 2781 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2782 2783 addrlen = af->to_addr_param(addr, &addrparam); 2784 if (!addrlen) 2785 return NULL; 2786 length += addrlen; 2787 2788 /* Create the chunk. */ 2789 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length, 2790 GFP_ATOMIC); 2791 if (!retval) 2792 return NULL; 2793 2794 asconf.serial = htonl(asoc->addip_serial++); 2795 2796 retval->subh.addip_hdr = 2797 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2798 retval->param_hdr.v = 2799 sctp_addto_chunk(retval, addrlen, &addrparam); 2800 2801 return retval; 2802 } 2803 2804 /* ADDIP 2805 * 3.2.1 Add IP Address 2806 * 0 1 2 3 2807 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2808 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2809 * | Type = 0xC001 | Length = Variable | 2810 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2811 * | ASCONF-Request Correlation ID | 2812 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2813 * | Address Parameter | 2814 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2815 * 2816 * 3.2.2 Delete IP Address 2817 * 0 1 2 3 2818 * 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 2819 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2820 * | Type = 0xC002 | Length = Variable | 2821 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2822 * | ASCONF-Request Correlation ID | 2823 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2824 * | Address Parameter | 2825 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2826 * 2827 */ 2828 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2829 union sctp_addr *laddr, 2830 struct sockaddr *addrs, 2831 int addrcnt, __be16 flags) 2832 { 2833 union sctp_addr_param addr_param; 2834 struct sctp_addip_param param; 2835 int paramlen = sizeof(param); 2836 struct sctp_chunk *retval; 2837 int addr_param_len = 0; 2838 union sctp_addr *addr; 2839 int totallen = 0, i; 2840 int del_pickup = 0; 2841 struct sctp_af *af; 2842 void *addr_buf; 2843 2844 /* Get total length of all the address parameters. */ 2845 addr_buf = addrs; 2846 for (i = 0; i < addrcnt; i++) { 2847 addr = addr_buf; 2848 af = sctp_get_af_specific(addr->v4.sin_family); 2849 addr_param_len = af->to_addr_param(addr, &addr_param); 2850 2851 totallen += paramlen; 2852 totallen += addr_param_len; 2853 2854 addr_buf += af->sockaddr_len; 2855 if (asoc->asconf_addr_del_pending && !del_pickup) { 2856 /* reuse the parameter length from the same scope one */ 2857 totallen += paramlen; 2858 totallen += addr_param_len; 2859 del_pickup = 1; 2860 2861 pr_debug("%s: picked same-scope del_pending addr, " 2862 "totallen for all addresses is %d\n", 2863 __func__, totallen); 2864 } 2865 } 2866 2867 /* Create an asconf chunk with the required length. */ 2868 retval = sctp_make_asconf(asoc, laddr, totallen); 2869 if (!retval) 2870 return NULL; 2871 2872 /* Add the address parameters to the asconf chunk. */ 2873 addr_buf = addrs; 2874 for (i = 0; i < addrcnt; i++) { 2875 addr = addr_buf; 2876 af = sctp_get_af_specific(addr->v4.sin_family); 2877 addr_param_len = af->to_addr_param(addr, &addr_param); 2878 param.param_hdr.type = flags; 2879 param.param_hdr.length = htons(paramlen + addr_param_len); 2880 param.crr_id = htonl(i); 2881 2882 sctp_addto_chunk(retval, paramlen, ¶m); 2883 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2884 2885 addr_buf += af->sockaddr_len; 2886 } 2887 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2888 addr = asoc->asconf_addr_del_pending; 2889 af = sctp_get_af_specific(addr->v4.sin_family); 2890 addr_param_len = af->to_addr_param(addr, &addr_param); 2891 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2892 param.param_hdr.length = htons(paramlen + addr_param_len); 2893 param.crr_id = htonl(i); 2894 2895 sctp_addto_chunk(retval, paramlen, ¶m); 2896 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2897 } 2898 return retval; 2899 } 2900 2901 /* ADDIP 2902 * 3.2.4 Set Primary IP Address 2903 * 0 1 2 3 2904 * 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 2905 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2906 * | Type =0xC004 | Length = Variable | 2907 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2908 * | ASCONF-Request Correlation ID | 2909 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2910 * | Address Parameter | 2911 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2912 * 2913 * Create an ASCONF chunk with Set Primary IP address parameter. 2914 */ 2915 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2916 union sctp_addr *addr) 2917 { 2918 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2919 union sctp_addr_param addrparam; 2920 struct sctp_addip_param param; 2921 struct sctp_chunk *retval; 2922 int len = sizeof(param); 2923 int addrlen; 2924 2925 addrlen = af->to_addr_param(addr, &addrparam); 2926 if (!addrlen) 2927 return NULL; 2928 len += addrlen; 2929 2930 /* Create the chunk and make asconf header. */ 2931 retval = sctp_make_asconf(asoc, addr, len); 2932 if (!retval) 2933 return NULL; 2934 2935 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2936 param.param_hdr.length = htons(len); 2937 param.crr_id = 0; 2938 2939 sctp_addto_chunk(retval, sizeof(param), ¶m); 2940 sctp_addto_chunk(retval, addrlen, &addrparam); 2941 2942 return retval; 2943 } 2944 2945 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2946 * 0 1 2 3 2947 * 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 2948 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2949 * | Type = 0x80 | Chunk Flags | Chunk Length | 2950 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2951 * | Serial Number | 2952 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2953 * | ASCONF Parameter Response#1 | 2954 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2955 * \ \ 2956 * / .... / 2957 * \ \ 2958 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2959 * | ASCONF Parameter Response#N | 2960 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2961 * 2962 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2963 */ 2964 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2965 __u32 serial, int vparam_len) 2966 { 2967 struct sctp_addiphdr asconf; 2968 struct sctp_chunk *retval; 2969 int length = sizeof(asconf) + vparam_len; 2970 2971 /* Create the chunk. */ 2972 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length, 2973 GFP_ATOMIC); 2974 if (!retval) 2975 return NULL; 2976 2977 asconf.serial = htonl(serial); 2978 2979 retval->subh.addip_hdr = 2980 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2981 2982 return retval; 2983 } 2984 2985 /* Add response parameters to an ASCONF_ACK chunk. */ 2986 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2987 __be16 err_code, 2988 struct sctp_addip_param *asconf_param) 2989 { 2990 struct sctp_addip_param ack_param; 2991 struct sctp_errhdr err_param; 2992 int asconf_param_len = 0; 2993 int err_param_len = 0; 2994 __be16 response_type; 2995 2996 if (SCTP_ERROR_NO_ERROR == err_code) { 2997 response_type = SCTP_PARAM_SUCCESS_REPORT; 2998 } else { 2999 response_type = SCTP_PARAM_ERR_CAUSE; 3000 err_param_len = sizeof(err_param); 3001 if (asconf_param) 3002 asconf_param_len = 3003 ntohs(asconf_param->param_hdr.length); 3004 } 3005 3006 /* Add Success Indication or Error Cause Indication parameter. */ 3007 ack_param.param_hdr.type = response_type; 3008 ack_param.param_hdr.length = htons(sizeof(ack_param) + 3009 err_param_len + 3010 asconf_param_len); 3011 ack_param.crr_id = crr_id; 3012 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 3013 3014 if (SCTP_ERROR_NO_ERROR == err_code) 3015 return; 3016 3017 /* Add Error Cause parameter. */ 3018 err_param.cause = err_code; 3019 err_param.length = htons(err_param_len + asconf_param_len); 3020 sctp_addto_chunk(chunk, err_param_len, &err_param); 3021 3022 /* Add the failed TLV copied from ASCONF chunk. */ 3023 if (asconf_param) 3024 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 3025 } 3026 3027 /* Process a asconf parameter. */ 3028 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 3029 struct sctp_chunk *asconf, 3030 struct sctp_addip_param *asconf_param) 3031 { 3032 union sctp_addr_param *addr_param; 3033 struct sctp_transport *peer; 3034 union sctp_addr addr; 3035 struct sctp_af *af; 3036 3037 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3038 3039 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 3040 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 3041 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 3042 return SCTP_ERROR_UNKNOWN_PARAM; 3043 3044 switch (addr_param->p.type) { 3045 case SCTP_PARAM_IPV6_ADDRESS: 3046 if (!asoc->peer.ipv6_address) 3047 return SCTP_ERROR_DNS_FAILED; 3048 break; 3049 case SCTP_PARAM_IPV4_ADDRESS: 3050 if (!asoc->peer.ipv4_address) 3051 return SCTP_ERROR_DNS_FAILED; 3052 break; 3053 default: 3054 return SCTP_ERROR_DNS_FAILED; 3055 } 3056 3057 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3058 if (unlikely(!af)) 3059 return SCTP_ERROR_DNS_FAILED; 3060 3061 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); 3062 3063 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3064 * or multicast address. 3065 * (note: wildcard is permitted and requires special handling so 3066 * make sure we check for that) 3067 */ 3068 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3069 return SCTP_ERROR_DNS_FAILED; 3070 3071 switch (asconf_param->param_hdr.type) { 3072 case SCTP_PARAM_ADD_IP: 3073 /* Section 4.2.1: 3074 * If the address 0.0.0.0 or ::0 is provided, the source 3075 * address of the packet MUST be added. 3076 */ 3077 if (af->is_any(&addr)) 3078 memcpy(&addr, &asconf->source, sizeof(addr)); 3079 3080 if (security_sctp_bind_connect(asoc->ep->base.sk, 3081 SCTP_PARAM_ADD_IP, 3082 (struct sockaddr *)&addr, 3083 af->sockaddr_len)) 3084 return SCTP_ERROR_REQ_REFUSED; 3085 3086 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3087 * request and does not have the local resources to add this 3088 * new address to the association, it MUST return an Error 3089 * Cause TLV set to the new error code 'Operation Refused 3090 * Due to Resource Shortage'. 3091 */ 3092 3093 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3094 if (!peer) 3095 return SCTP_ERROR_RSRC_LOW; 3096 3097 /* Start the heartbeat timer. */ 3098 sctp_transport_reset_hb_timer(peer); 3099 asoc->new_transport = peer; 3100 break; 3101 case SCTP_PARAM_DEL_IP: 3102 /* ADDIP 4.3 D7) If a request is received to delete the 3103 * last remaining IP address of a peer endpoint, the receiver 3104 * MUST send an Error Cause TLV with the error cause set to the 3105 * new error code 'Request to Delete Last Remaining IP Address'. 3106 */ 3107 if (asoc->peer.transport_count == 1) 3108 return SCTP_ERROR_DEL_LAST_IP; 3109 3110 /* ADDIP 4.3 D8) If a request is received to delete an IP 3111 * address which is also the source address of the IP packet 3112 * which contained the ASCONF chunk, the receiver MUST reject 3113 * this request. To reject the request the receiver MUST send 3114 * an Error Cause TLV set to the new error code 'Request to 3115 * Delete Source IP Address' 3116 */ 3117 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3118 return SCTP_ERROR_DEL_SRC_IP; 3119 3120 /* Section 4.2.2 3121 * If the address 0.0.0.0 or ::0 is provided, all 3122 * addresses of the peer except the source address of the 3123 * packet MUST be deleted. 3124 */ 3125 if (af->is_any(&addr)) { 3126 sctp_assoc_set_primary(asoc, asconf->transport); 3127 sctp_assoc_del_nonprimary_peers(asoc, 3128 asconf->transport); 3129 return SCTP_ERROR_NO_ERROR; 3130 } 3131 3132 /* If the address is not part of the association, the 3133 * ASCONF-ACK with Error Cause Indication Parameter 3134 * which including cause of Unresolvable Address should 3135 * be sent. 3136 */ 3137 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3138 if (!peer) 3139 return SCTP_ERROR_DNS_FAILED; 3140 3141 sctp_assoc_rm_peer(asoc, peer); 3142 break; 3143 case SCTP_PARAM_SET_PRIMARY: 3144 /* ADDIP Section 4.2.4 3145 * If the address 0.0.0.0 or ::0 is provided, the receiver 3146 * MAY mark the source address of the packet as its 3147 * primary. 3148 */ 3149 if (af->is_any(&addr)) 3150 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr)); 3151 3152 if (security_sctp_bind_connect(asoc->ep->base.sk, 3153 SCTP_PARAM_SET_PRIMARY, 3154 (struct sockaddr *)&addr, 3155 af->sockaddr_len)) 3156 return SCTP_ERROR_REQ_REFUSED; 3157 3158 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3159 if (!peer) 3160 return SCTP_ERROR_DNS_FAILED; 3161 3162 sctp_assoc_set_primary(asoc, peer); 3163 break; 3164 } 3165 3166 return SCTP_ERROR_NO_ERROR; 3167 } 3168 3169 /* Verify the ASCONF packet before we process it. */ 3170 bool sctp_verify_asconf(const struct sctp_association *asoc, 3171 struct sctp_chunk *chunk, bool addr_param_needed, 3172 struct sctp_paramhdr **errp) 3173 { 3174 struct sctp_addip_chunk *addip; 3175 bool addr_param_seen = false; 3176 union sctp_params param; 3177 3178 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr; 3179 sctp_walk_params(param, addip, addip_hdr.params) { 3180 size_t length = ntohs(param.p->length); 3181 3182 *errp = param.p; 3183 switch (param.p->type) { 3184 case SCTP_PARAM_ERR_CAUSE: 3185 break; 3186 case SCTP_PARAM_IPV4_ADDRESS: 3187 if (length != sizeof(struct sctp_ipv4addr_param)) 3188 return false; 3189 /* ensure there is only one addr param and it's in the 3190 * beginning of addip_hdr params, or we reject it. 3191 */ 3192 if (param.v != addip->addip_hdr.params) 3193 return false; 3194 addr_param_seen = true; 3195 break; 3196 case SCTP_PARAM_IPV6_ADDRESS: 3197 if (length != sizeof(struct sctp_ipv6addr_param)) 3198 return false; 3199 if (param.v != addip->addip_hdr.params) 3200 return false; 3201 addr_param_seen = true; 3202 break; 3203 case SCTP_PARAM_ADD_IP: 3204 case SCTP_PARAM_DEL_IP: 3205 case SCTP_PARAM_SET_PRIMARY: 3206 /* In ASCONF chunks, these need to be first. */ 3207 if (addr_param_needed && !addr_param_seen) 3208 return false; 3209 length = ntohs(param.addip->param_hdr.length); 3210 if (length < sizeof(struct sctp_addip_param) + 3211 sizeof(**errp)) 3212 return false; 3213 break; 3214 case SCTP_PARAM_SUCCESS_REPORT: 3215 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3216 if (length != sizeof(struct sctp_addip_param)) 3217 return false; 3218 break; 3219 default: 3220 /* This is unkown to us, reject! */ 3221 return false; 3222 } 3223 } 3224 3225 /* Remaining sanity checks. */ 3226 if (addr_param_needed && !addr_param_seen) 3227 return false; 3228 if (!addr_param_needed && addr_param_seen) 3229 return false; 3230 if (param.v != chunk->chunk_end) 3231 return false; 3232 3233 return true; 3234 } 3235 3236 /* Process an incoming ASCONF chunk with the next expected serial no. and 3237 * return an ASCONF_ACK chunk to be sent in response. 3238 */ 3239 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3240 struct sctp_chunk *asconf) 3241 { 3242 union sctp_addr_param *addr_param; 3243 struct sctp_addip_chunk *addip; 3244 struct sctp_chunk *asconf_ack; 3245 bool all_param_pass = true; 3246 struct sctp_addiphdr *hdr; 3247 int length = 0, chunk_len; 3248 union sctp_params param; 3249 __be16 err_code; 3250 __u32 serial; 3251 3252 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr; 3253 chunk_len = ntohs(asconf->chunk_hdr->length) - 3254 sizeof(struct sctp_chunkhdr); 3255 hdr = (struct sctp_addiphdr *)asconf->skb->data; 3256 serial = ntohl(hdr->serial); 3257 3258 /* Skip the addiphdr and store a pointer to address parameter. */ 3259 length = sizeof(*hdr); 3260 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3261 chunk_len -= length; 3262 3263 /* Skip the address parameter and store a pointer to the first 3264 * asconf parameter. 3265 */ 3266 length = ntohs(addr_param->p.length); 3267 chunk_len -= length; 3268 3269 /* create an ASCONF_ACK chunk. 3270 * Based on the definitions of parameters, we know that the size of 3271 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3272 * parameters. 3273 */ 3274 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3275 if (!asconf_ack) 3276 goto done; 3277 3278 /* Process the TLVs contained within the ASCONF chunk. */ 3279 sctp_walk_params(param, addip, addip_hdr.params) { 3280 /* Skip preceeding address parameters. */ 3281 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 3282 param.p->type == SCTP_PARAM_IPV6_ADDRESS) 3283 continue; 3284 3285 err_code = sctp_process_asconf_param(asoc, asconf, 3286 param.addip); 3287 /* ADDIP 4.1 A7) 3288 * If an error response is received for a TLV parameter, 3289 * all TLVs with no response before the failed TLV are 3290 * considered successful if not reported. All TLVs after 3291 * the failed response are considered unsuccessful unless 3292 * a specific success indication is present for the parameter. 3293 */ 3294 if (err_code != SCTP_ERROR_NO_ERROR) 3295 all_param_pass = false; 3296 if (!all_param_pass) 3297 sctp_add_asconf_response(asconf_ack, param.addip->crr_id, 3298 err_code, param.addip); 3299 3300 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3301 * an IP address sends an 'Out of Resource' in its response, it 3302 * MUST also fail any subsequent add or delete requests bundled 3303 * in the ASCONF. 3304 */ 3305 if (err_code == SCTP_ERROR_RSRC_LOW) 3306 goto done; 3307 } 3308 done: 3309 asoc->peer.addip_serial++; 3310 3311 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3312 * after freeing the reference to old asconf ack if any. 3313 */ 3314 if (asconf_ack) { 3315 sctp_chunk_hold(asconf_ack); 3316 list_add_tail(&asconf_ack->transmitted_list, 3317 &asoc->asconf_ack_list); 3318 } 3319 3320 return asconf_ack; 3321 } 3322 3323 /* Process a asconf parameter that is successfully acked. */ 3324 static void sctp_asconf_param_success(struct sctp_association *asoc, 3325 struct sctp_addip_param *asconf_param) 3326 { 3327 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3328 union sctp_addr_param *addr_param; 3329 struct sctp_sockaddr_entry *saddr; 3330 struct sctp_transport *transport; 3331 union sctp_addr addr; 3332 struct sctp_af *af; 3333 3334 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3335 3336 /* We have checked the packet before, so we do not check again. */ 3337 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3338 af->from_addr_param(&addr, addr_param, htons(bp->port), 0); 3339 3340 switch (asconf_param->param_hdr.type) { 3341 case SCTP_PARAM_ADD_IP: 3342 /* This is always done in BH context with a socket lock 3343 * held, so the list can not change. 3344 */ 3345 local_bh_disable(); 3346 list_for_each_entry(saddr, &bp->address_list, list) { 3347 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3348 saddr->state = SCTP_ADDR_SRC; 3349 } 3350 local_bh_enable(); 3351 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3352 transports) { 3353 sctp_transport_dst_release(transport); 3354 } 3355 break; 3356 case SCTP_PARAM_DEL_IP: 3357 local_bh_disable(); 3358 sctp_del_bind_addr(bp, &addr); 3359 if (asoc->asconf_addr_del_pending != NULL && 3360 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3361 kfree(asoc->asconf_addr_del_pending); 3362 asoc->asconf_addr_del_pending = NULL; 3363 } 3364 local_bh_enable(); 3365 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3366 transports) { 3367 sctp_transport_dst_release(transport); 3368 } 3369 break; 3370 default: 3371 break; 3372 } 3373 } 3374 3375 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3376 * for the given asconf parameter. If there is no response for this parameter, 3377 * return the error code based on the third argument 'no_err'. 3378 * ADDIP 4.1 3379 * A7) If an error response is received for a TLV parameter, all TLVs with no 3380 * response before the failed TLV are considered successful if not reported. 3381 * All TLVs after the failed response are considered unsuccessful unless a 3382 * specific success indication is present for the parameter. 3383 */ 3384 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3385 struct sctp_addip_param *asconf_param, 3386 int no_err) 3387 { 3388 struct sctp_addip_param *asconf_ack_param; 3389 struct sctp_errhdr *err_param; 3390 int asconf_ack_len; 3391 __be16 err_code; 3392 int length; 3393 3394 if (no_err) 3395 err_code = SCTP_ERROR_NO_ERROR; 3396 else 3397 err_code = SCTP_ERROR_REQ_REFUSED; 3398 3399 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3400 sizeof(struct sctp_chunkhdr); 3401 3402 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3403 * the first asconf_ack parameter. 3404 */ 3405 length = sizeof(struct sctp_addiphdr); 3406 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data + 3407 length); 3408 asconf_ack_len -= length; 3409 3410 while (asconf_ack_len > 0) { 3411 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3412 switch (asconf_ack_param->param_hdr.type) { 3413 case SCTP_PARAM_SUCCESS_REPORT: 3414 return SCTP_ERROR_NO_ERROR; 3415 case SCTP_PARAM_ERR_CAUSE: 3416 length = sizeof(*asconf_ack_param); 3417 err_param = (void *)asconf_ack_param + length; 3418 asconf_ack_len -= length; 3419 if (asconf_ack_len > 0) 3420 return err_param->cause; 3421 else 3422 return SCTP_ERROR_INV_PARAM; 3423 break; 3424 default: 3425 return SCTP_ERROR_INV_PARAM; 3426 } 3427 } 3428 3429 length = ntohs(asconf_ack_param->param_hdr.length); 3430 asconf_ack_param = (void *)asconf_ack_param + length; 3431 asconf_ack_len -= length; 3432 } 3433 3434 return err_code; 3435 } 3436 3437 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3438 int sctp_process_asconf_ack(struct sctp_association *asoc, 3439 struct sctp_chunk *asconf_ack) 3440 { 3441 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3442 struct sctp_addip_param *asconf_param; 3443 __be16 err_code = SCTP_ERROR_NO_ERROR; 3444 union sctp_addr_param *addr_param; 3445 int asconf_len = asconf->skb->len; 3446 int all_param_pass = 0; 3447 int length = 0; 3448 int no_err = 1; 3449 int retval = 0; 3450 3451 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3452 * a pointer to address parameter. 3453 */ 3454 length = sizeof(struct sctp_addip_chunk); 3455 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3456 asconf_len -= length; 3457 3458 /* Skip the address parameter in the last asconf sent and store a 3459 * pointer to the first asconf parameter. 3460 */ 3461 length = ntohs(addr_param->p.length); 3462 asconf_param = (void *)addr_param + length; 3463 asconf_len -= length; 3464 3465 /* ADDIP 4.1 3466 * A8) If there is no response(s) to specific TLV parameter(s), and no 3467 * failures are indicated, then all request(s) are considered 3468 * successful. 3469 */ 3470 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr)) 3471 all_param_pass = 1; 3472 3473 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3474 while (asconf_len > 0) { 3475 if (all_param_pass) 3476 err_code = SCTP_ERROR_NO_ERROR; 3477 else { 3478 err_code = sctp_get_asconf_response(asconf_ack, 3479 asconf_param, 3480 no_err); 3481 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3482 no_err = 0; 3483 } 3484 3485 switch (err_code) { 3486 case SCTP_ERROR_NO_ERROR: 3487 sctp_asconf_param_success(asoc, asconf_param); 3488 break; 3489 3490 case SCTP_ERROR_RSRC_LOW: 3491 retval = 1; 3492 break; 3493 3494 case SCTP_ERROR_UNKNOWN_PARAM: 3495 /* Disable sending this type of asconf parameter in 3496 * future. 3497 */ 3498 asoc->peer.addip_disabled_mask |= 3499 asconf_param->param_hdr.type; 3500 break; 3501 3502 case SCTP_ERROR_REQ_REFUSED: 3503 case SCTP_ERROR_DEL_LAST_IP: 3504 case SCTP_ERROR_DEL_SRC_IP: 3505 default: 3506 break; 3507 } 3508 3509 /* Skip the processed asconf parameter and move to the next 3510 * one. 3511 */ 3512 length = ntohs(asconf_param->param_hdr.length); 3513 asconf_param = (void *)asconf_param + length; 3514 asconf_len -= length; 3515 } 3516 3517 if (no_err && asoc->src_out_of_asoc_ok) { 3518 asoc->src_out_of_asoc_ok = 0; 3519 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3520 } 3521 3522 /* Free the cached last sent asconf chunk. */ 3523 list_del_init(&asconf->transmitted_list); 3524 sctp_chunk_free(asconf); 3525 asoc->addip_last_asconf = NULL; 3526 3527 return retval; 3528 } 3529 3530 /* Make a FWD TSN chunk. */ 3531 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3532 __u32 new_cum_tsn, size_t nstreams, 3533 struct sctp_fwdtsn_skip *skiplist) 3534 { 3535 struct sctp_chunk *retval = NULL; 3536 struct sctp_fwdtsn_hdr ftsn_hdr; 3537 struct sctp_fwdtsn_skip skip; 3538 size_t hint; 3539 int i; 3540 3541 hint = (nstreams + 1) * sizeof(__u32); 3542 3543 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC); 3544 3545 if (!retval) 3546 return NULL; 3547 3548 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3549 retval->subh.fwdtsn_hdr = 3550 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3551 3552 for (i = 0; i < nstreams; i++) { 3553 skip.stream = skiplist[i].stream; 3554 skip.ssn = skiplist[i].ssn; 3555 sctp_addto_chunk(retval, sizeof(skip), &skip); 3556 } 3557 3558 return retval; 3559 } 3560 3561 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc, 3562 __u32 new_cum_tsn, size_t nstreams, 3563 struct sctp_ifwdtsn_skip *skiplist) 3564 { 3565 struct sctp_chunk *retval = NULL; 3566 struct sctp_ifwdtsn_hdr ftsn_hdr; 3567 size_t hint; 3568 3569 hint = (nstreams + 1) * sizeof(__u32); 3570 3571 retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint, 3572 GFP_ATOMIC); 3573 if (!retval) 3574 return NULL; 3575 3576 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3577 retval->subh.ifwdtsn_hdr = 3578 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3579 3580 sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist); 3581 3582 return retval; 3583 } 3584 3585 /* RE-CONFIG 3.1 (RE-CONFIG chunk) 3586 * 0 1 2 3 3587 * 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 3588 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3589 * | Type = 130 | Chunk Flags | Chunk Length | 3590 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3591 * \ \ 3592 * / Re-configuration Parameter / 3593 * \ \ 3594 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3595 * \ \ 3596 * / Re-configuration Parameter (optional) / 3597 * \ \ 3598 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3599 */ 3600 static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc, 3601 int length) 3602 { 3603 struct sctp_reconf_chunk *reconf; 3604 struct sctp_chunk *retval; 3605 3606 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length, 3607 GFP_ATOMIC); 3608 if (!retval) 3609 return NULL; 3610 3611 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr; 3612 retval->param_hdr.v = reconf->params; 3613 3614 return retval; 3615 } 3616 3617 /* RE-CONFIG 4.1 (STREAM OUT RESET) 3618 * 0 1 2 3 3619 * 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 3620 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3621 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N | 3622 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3623 * | Re-configuration Request Sequence Number | 3624 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3625 * | Re-configuration Response Sequence Number | 3626 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3627 * | Sender's Last Assigned TSN | 3628 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3629 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3630 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3631 * / ...... / 3632 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3633 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3634 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3635 * 3636 * RE-CONFIG 4.2 (STREAM IN RESET) 3637 * 0 1 2 3 3638 * 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 3639 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3640 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N | 3641 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3642 * | Re-configuration Request Sequence Number | 3643 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3644 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3645 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3646 * / ...... / 3647 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3648 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3649 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3650 */ 3651 struct sctp_chunk *sctp_make_strreset_req( 3652 const struct sctp_association *asoc, 3653 __u16 stream_num, __be16 *stream_list, 3654 bool out, bool in) 3655 { 3656 __u16 stream_len = stream_num * sizeof(__u16); 3657 struct sctp_strreset_outreq outreq; 3658 struct sctp_strreset_inreq inreq; 3659 struct sctp_chunk *retval; 3660 __u16 outlen, inlen; 3661 3662 outlen = (sizeof(outreq) + stream_len) * out; 3663 inlen = (sizeof(inreq) + stream_len) * in; 3664 3665 retval = sctp_make_reconf(asoc, outlen + inlen); 3666 if (!retval) 3667 return NULL; 3668 3669 if (outlen) { 3670 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST; 3671 outreq.param_hdr.length = htons(outlen); 3672 outreq.request_seq = htonl(asoc->strreset_outseq); 3673 outreq.response_seq = htonl(asoc->strreset_inseq - 1); 3674 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1); 3675 3676 sctp_addto_chunk(retval, sizeof(outreq), &outreq); 3677 3678 if (stream_len) 3679 sctp_addto_chunk(retval, stream_len, stream_list); 3680 } 3681 3682 if (inlen) { 3683 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST; 3684 inreq.param_hdr.length = htons(inlen); 3685 inreq.request_seq = htonl(asoc->strreset_outseq + out); 3686 3687 sctp_addto_chunk(retval, sizeof(inreq), &inreq); 3688 3689 if (stream_len) 3690 sctp_addto_chunk(retval, stream_len, stream_list); 3691 } 3692 3693 return retval; 3694 } 3695 3696 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL) 3697 * 0 1 2 3 3698 * 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 3699 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3700 * | Parameter Type = 15 | Parameter Length = 8 | 3701 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3702 * | Re-configuration Request Sequence Number | 3703 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3704 */ 3705 struct sctp_chunk *sctp_make_strreset_tsnreq( 3706 const struct sctp_association *asoc) 3707 { 3708 struct sctp_strreset_tsnreq tsnreq; 3709 __u16 length = sizeof(tsnreq); 3710 struct sctp_chunk *retval; 3711 3712 retval = sctp_make_reconf(asoc, length); 3713 if (!retval) 3714 return NULL; 3715 3716 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST; 3717 tsnreq.param_hdr.length = htons(length); 3718 tsnreq.request_seq = htonl(asoc->strreset_outseq); 3719 3720 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq); 3721 3722 return retval; 3723 } 3724 3725 /* RE-CONFIG 4.5/4.6 (ADD STREAM) 3726 * 0 1 2 3 3727 * 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 3728 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3729 * | Parameter Type = 17 | Parameter Length = 12 | 3730 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3731 * | Re-configuration Request Sequence Number | 3732 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3733 * | Number of new streams | Reserved | 3734 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3735 */ 3736 struct sctp_chunk *sctp_make_strreset_addstrm( 3737 const struct sctp_association *asoc, 3738 __u16 out, __u16 in) 3739 { 3740 struct sctp_strreset_addstrm addstrm; 3741 __u16 size = sizeof(addstrm); 3742 struct sctp_chunk *retval; 3743 3744 retval = sctp_make_reconf(asoc, (!!out + !!in) * size); 3745 if (!retval) 3746 return NULL; 3747 3748 if (out) { 3749 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS; 3750 addstrm.param_hdr.length = htons(size); 3751 addstrm.number_of_streams = htons(out); 3752 addstrm.request_seq = htonl(asoc->strreset_outseq); 3753 addstrm.reserved = 0; 3754 3755 sctp_addto_chunk(retval, size, &addstrm); 3756 } 3757 3758 if (in) { 3759 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS; 3760 addstrm.param_hdr.length = htons(size); 3761 addstrm.number_of_streams = htons(in); 3762 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out); 3763 addstrm.reserved = 0; 3764 3765 sctp_addto_chunk(retval, size, &addstrm); 3766 } 3767 3768 return retval; 3769 } 3770 3771 /* RE-CONFIG 4.4 (RESP) 3772 * 0 1 2 3 3773 * 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 3774 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3775 * | Parameter Type = 16 | Parameter Length | 3776 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3777 * | Re-configuration Response Sequence Number | 3778 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3779 * | Result | 3780 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3781 */ 3782 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc, 3783 __u32 result, __u32 sn) 3784 { 3785 struct sctp_strreset_resp resp; 3786 __u16 length = sizeof(resp); 3787 struct sctp_chunk *retval; 3788 3789 retval = sctp_make_reconf(asoc, length); 3790 if (!retval) 3791 return NULL; 3792 3793 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3794 resp.param_hdr.length = htons(length); 3795 resp.response_seq = htonl(sn); 3796 resp.result = htonl(result); 3797 3798 sctp_addto_chunk(retval, sizeof(resp), &resp); 3799 3800 return retval; 3801 } 3802 3803 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP) 3804 * 0 1 2 3 3805 * 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 3806 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3807 * | Parameter Type = 16 | Parameter Length | 3808 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3809 * | Re-configuration Response Sequence Number | 3810 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3811 * | Result | 3812 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3813 * | Sender's Next TSN (optional) | 3814 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3815 * | Receiver's Next TSN (optional) | 3816 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3817 */ 3818 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc, 3819 __u32 result, __u32 sn, 3820 __u32 sender_tsn, 3821 __u32 receiver_tsn) 3822 { 3823 struct sctp_strreset_resptsn tsnresp; 3824 __u16 length = sizeof(tsnresp); 3825 struct sctp_chunk *retval; 3826 3827 retval = sctp_make_reconf(asoc, length); 3828 if (!retval) 3829 return NULL; 3830 3831 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3832 tsnresp.param_hdr.length = htons(length); 3833 3834 tsnresp.response_seq = htonl(sn); 3835 tsnresp.result = htonl(result); 3836 tsnresp.senders_next_tsn = htonl(sender_tsn); 3837 tsnresp.receivers_next_tsn = htonl(receiver_tsn); 3838 3839 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp); 3840 3841 return retval; 3842 } 3843 3844 bool sctp_verify_reconf(const struct sctp_association *asoc, 3845 struct sctp_chunk *chunk, 3846 struct sctp_paramhdr **errp) 3847 { 3848 struct sctp_reconf_chunk *hdr; 3849 union sctp_params param; 3850 __be16 last = 0; 3851 __u16 cnt = 0; 3852 3853 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; 3854 sctp_walk_params(param, hdr, params) { 3855 __u16 length = ntohs(param.p->length); 3856 3857 *errp = param.p; 3858 if (cnt++ > 2) 3859 return false; 3860 switch (param.p->type) { 3861 case SCTP_PARAM_RESET_OUT_REQUEST: 3862 if (length < sizeof(struct sctp_strreset_outreq) || 3863 (last && last != SCTP_PARAM_RESET_RESPONSE && 3864 last != SCTP_PARAM_RESET_IN_REQUEST)) 3865 return false; 3866 break; 3867 case SCTP_PARAM_RESET_IN_REQUEST: 3868 if (length < sizeof(struct sctp_strreset_inreq) || 3869 (last && last != SCTP_PARAM_RESET_OUT_REQUEST)) 3870 return false; 3871 break; 3872 case SCTP_PARAM_RESET_RESPONSE: 3873 if ((length != sizeof(struct sctp_strreset_resp) && 3874 length != sizeof(struct sctp_strreset_resptsn)) || 3875 (last && last != SCTP_PARAM_RESET_RESPONSE && 3876 last != SCTP_PARAM_RESET_OUT_REQUEST)) 3877 return false; 3878 break; 3879 case SCTP_PARAM_RESET_TSN_REQUEST: 3880 if (length != 3881 sizeof(struct sctp_strreset_tsnreq) || last) 3882 return false; 3883 break; 3884 case SCTP_PARAM_RESET_ADD_IN_STREAMS: 3885 if (length != sizeof(struct sctp_strreset_addstrm) || 3886 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS)) 3887 return false; 3888 break; 3889 case SCTP_PARAM_RESET_ADD_OUT_STREAMS: 3890 if (length != sizeof(struct sctp_strreset_addstrm) || 3891 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS)) 3892 return false; 3893 break; 3894 default: 3895 return false; 3896 } 3897 3898 last = param.p->type; 3899 } 3900 3901 return true; 3902 } 3903