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/utils.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 /* RFC 2960 3.3.2 Initiation (INIT) (1) 119 * 120 * Note 2: The ECN capable field is reserved for future use of 121 * Explicit Congestion Notification. 122 */ 123 static const struct sctp_paramhdr ecap_param = { 124 SCTP_PARAM_ECN_CAPABLE, 125 cpu_to_be16(sizeof(struct sctp_paramhdr)), 126 }; 127 static const struct sctp_paramhdr prsctp_param = { 128 SCTP_PARAM_FWD_TSN_SUPPORT, 129 cpu_to_be16(sizeof(struct sctp_paramhdr)), 130 }; 131 132 /* A helper to initialize an op error inside a provided chunk, as most 133 * cause codes will be embedded inside an abort chunk. 134 */ 135 int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, 136 size_t paylen) 137 { 138 struct sctp_errhdr err; 139 __u16 len; 140 141 /* Cause code constants are now defined in network order. */ 142 err.cause = cause_code; 143 len = sizeof(err) + paylen; 144 err.length = htons(len); 145 146 if (skb_tailroom(chunk->skb) < len) 147 return -ENOSPC; 148 149 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(err), &err); 150 151 return 0; 152 } 153 154 /* 3.3.2 Initiation (INIT) (1) 155 * 156 * This chunk is used to initiate a SCTP association between two 157 * endpoints. The format of the INIT chunk is shown below: 158 * 159 * 0 1 2 3 160 * 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 1 161 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 162 * | Type = 1 | Chunk Flags | Chunk Length | 163 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 164 * | Initiate Tag | 165 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 166 * | Advertised Receiver Window Credit (a_rwnd) | 167 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 168 * | Number of Outbound Streams | Number of Inbound Streams | 169 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 170 * | Initial TSN | 171 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 172 * \ \ 173 * / Optional/Variable-Length Parameters / 174 * \ \ 175 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 176 * 177 * 178 * The INIT chunk contains the following parameters. Unless otherwise 179 * noted, each parameter MUST only be included once in the INIT chunk. 180 * 181 * Fixed Parameters Status 182 * ---------------------------------------------- 183 * Initiate Tag Mandatory 184 * Advertised Receiver Window Credit Mandatory 185 * Number of Outbound Streams Mandatory 186 * Number of Inbound Streams Mandatory 187 * Initial TSN Mandatory 188 * 189 * Variable Parameters Status Type Value 190 * ------------------------------------------------------------- 191 * IPv4 Address (Note 1) Optional 5 192 * IPv6 Address (Note 1) Optional 6 193 * Cookie Preservative Optional 9 194 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000) 195 * Host Name Address (Note 3) Optional 11 196 * Supported Address Types (Note 4) Optional 12 197 */ 198 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc, 199 const struct sctp_bind_addr *bp, 200 gfp_t gfp, int vparam_len) 201 { 202 struct sctp_supported_ext_param ext_param; 203 struct sctp_adaptation_ind_param aiparam; 204 struct sctp_paramhdr *auth_chunks = NULL; 205 struct sctp_paramhdr *auth_hmacs = NULL; 206 struct sctp_supported_addrs_param sat; 207 struct sctp_endpoint *ep = asoc->ep; 208 struct sctp_chunk *retval = NULL; 209 int num_types, addrs_len = 0; 210 struct sctp_inithdr init; 211 union sctp_params addrs; 212 struct sctp_sock *sp; 213 __u8 extensions[5]; 214 size_t chunksize; 215 __be16 types[2]; 216 int num_ext = 0; 217 218 /* RFC 2960 3.3.2 Initiation (INIT) (1) 219 * 220 * Note 1: The INIT chunks can contain multiple addresses that 221 * can be IPv4 and/or IPv6 in any combination. 222 */ 223 224 /* Convert the provided bind address list to raw format. */ 225 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp); 226 227 init.init_tag = htonl(asoc->c.my_vtag); 228 init.a_rwnd = htonl(asoc->rwnd); 229 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 230 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 231 init.initial_tsn = htonl(asoc->c.initial_tsn); 232 233 /* How many address types are needed? */ 234 sp = sctp_sk(asoc->base.sk); 235 num_types = sp->pf->supported_addrs(sp, types); 236 237 chunksize = sizeof(init) + addrs_len; 238 chunksize += SCTP_PAD4(SCTP_SAT_LEN(num_types)); 239 240 if (asoc->ep->ecn_enable) 241 chunksize += sizeof(ecap_param); 242 243 if (asoc->ep->prsctp_enable) 244 chunksize += sizeof(prsctp_param); 245 246 /* ADDIP: Section 4.2.7: 247 * An implementation supporting this extension [ADDIP] MUST list 248 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and 249 * INIT-ACK parameters. 250 */ 251 if (asoc->ep->asconf_enable) { 252 extensions[num_ext] = SCTP_CID_ASCONF; 253 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 254 num_ext += 2; 255 } 256 257 if (asoc->ep->reconf_enable) { 258 extensions[num_ext] = SCTP_CID_RECONF; 259 num_ext += 1; 260 } 261 262 if (sp->adaptation_ind) 263 chunksize += sizeof(aiparam); 264 265 if (asoc->ep->intl_enable) { 266 extensions[num_ext] = SCTP_CID_I_DATA; 267 num_ext += 1; 268 } 269 270 chunksize += vparam_len; 271 272 /* Account for AUTH related parameters */ 273 if (ep->auth_enable) { 274 /* Add random parameter length*/ 275 chunksize += sizeof(asoc->c.auth_random); 276 277 /* Add HMACS parameter length if any were defined */ 278 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; 279 if (auth_hmacs->length) 280 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 281 else 282 auth_hmacs = NULL; 283 284 /* Add CHUNKS parameter length */ 285 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; 286 if (auth_chunks->length) 287 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 288 else 289 auth_chunks = NULL; 290 291 extensions[num_ext] = SCTP_CID_AUTH; 292 num_ext += 1; 293 } 294 295 /* If we have any extensions to report, account for that */ 296 if (num_ext) 297 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext); 298 299 /* RFC 2960 3.3.2 Initiation (INIT) (1) 300 * 301 * Note 3: An INIT chunk MUST NOT contain more than one Host 302 * Name address parameter. Moreover, the sender of the INIT 303 * MUST NOT combine any other address types with the Host Name 304 * address in the INIT. The receiver of INIT MUST ignore any 305 * other address types if the Host Name address parameter is 306 * present in the received INIT chunk. 307 * 308 * PLEASE DO NOT FIXME [This version does not support Host Name.] 309 */ 310 311 retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp); 312 if (!retval) 313 goto nodata; 314 315 retval->subh.init_hdr = 316 sctp_addto_chunk(retval, sizeof(init), &init); 317 retval->param_hdr.v = 318 sctp_addto_chunk(retval, addrs_len, addrs.v); 319 320 /* RFC 2960 3.3.2 Initiation (INIT) (1) 321 * 322 * Note 4: This parameter, when present, specifies all the 323 * address types the sending endpoint can support. The absence 324 * of this parameter indicates that the sending endpoint can 325 * support any address type. 326 */ 327 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES; 328 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types)); 329 sctp_addto_chunk(retval, sizeof(sat), &sat); 330 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types); 331 332 if (asoc->ep->ecn_enable) 333 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 334 335 /* Add the supported extensions parameter. Be nice and add this 336 * fist before addiding the parameters for the extensions themselves 337 */ 338 if (num_ext) { 339 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 340 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext); 341 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); 342 sctp_addto_param(retval, num_ext, extensions); 343 } 344 345 if (asoc->ep->prsctp_enable) 346 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 347 348 if (sp->adaptation_ind) { 349 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 350 aiparam.param_hdr.length = htons(sizeof(aiparam)); 351 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 352 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 353 } 354 355 /* Add SCTP-AUTH chunks to the parameter list */ 356 if (ep->auth_enable) { 357 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random), 358 asoc->c.auth_random); 359 if (auth_hmacs) 360 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 361 auth_hmacs); 362 if (auth_chunks) 363 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 364 auth_chunks); 365 } 366 nodata: 367 kfree(addrs.v); 368 return retval; 369 } 370 371 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, 372 const struct sctp_chunk *chunk, 373 gfp_t gfp, int unkparam_len) 374 { 375 struct sctp_supported_ext_param ext_param; 376 struct sctp_adaptation_ind_param aiparam; 377 struct sctp_paramhdr *auth_chunks = NULL; 378 struct sctp_paramhdr *auth_random = NULL; 379 struct sctp_paramhdr *auth_hmacs = NULL; 380 struct sctp_chunk *retval = NULL; 381 struct sctp_cookie_param *cookie; 382 struct sctp_inithdr initack; 383 union sctp_params addrs; 384 struct sctp_sock *sp; 385 __u8 extensions[5]; 386 size_t chunksize; 387 int num_ext = 0; 388 int cookie_len; 389 int addrs_len; 390 391 /* Note: there may be no addresses to embed. */ 392 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp); 393 394 initack.init_tag = htonl(asoc->c.my_vtag); 395 initack.a_rwnd = htonl(asoc->rwnd); 396 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 397 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 398 initack.initial_tsn = htonl(asoc->c.initial_tsn); 399 400 /* FIXME: We really ought to build the cookie right 401 * into the packet instead of allocating more fresh memory. 402 */ 403 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len, 404 addrs.v, addrs_len); 405 if (!cookie) 406 goto nomem_cookie; 407 408 /* Calculate the total size of allocation, include the reserved 409 * space for reporting unknown parameters if it is specified. 410 */ 411 sp = sctp_sk(asoc->base.sk); 412 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len; 413 414 /* Tell peer that we'll do ECN only if peer advertised such cap. */ 415 if (asoc->peer.ecn_capable) 416 chunksize += sizeof(ecap_param); 417 418 if (asoc->peer.prsctp_capable) 419 chunksize += sizeof(prsctp_param); 420 421 if (asoc->peer.asconf_capable) { 422 extensions[num_ext] = SCTP_CID_ASCONF; 423 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 424 num_ext += 2; 425 } 426 427 if (asoc->peer.reconf_capable) { 428 extensions[num_ext] = SCTP_CID_RECONF; 429 num_ext += 1; 430 } 431 432 if (sp->adaptation_ind) 433 chunksize += sizeof(aiparam); 434 435 if (asoc->peer.intl_capable) { 436 extensions[num_ext] = SCTP_CID_I_DATA; 437 num_ext += 1; 438 } 439 440 if (asoc->peer.auth_capable) { 441 auth_random = (struct sctp_paramhdr *)asoc->c.auth_random; 442 chunksize += ntohs(auth_random->length); 443 444 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; 445 if (auth_hmacs->length) 446 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 447 else 448 auth_hmacs = NULL; 449 450 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; 451 if (auth_chunks->length) 452 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 453 else 454 auth_chunks = NULL; 455 456 extensions[num_ext] = SCTP_CID_AUTH; 457 num_ext += 1; 458 } 459 460 if (num_ext) 461 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext); 462 463 /* Now allocate and fill out the chunk. */ 464 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp); 465 if (!retval) 466 goto nomem_chunk; 467 468 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 469 * 470 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 471 * HEARTBEAT ACK, * etc.) to the same destination transport 472 * address from which it received the DATA or control chunk 473 * to which it is replying. 474 * 475 * [INIT ACK back to where the INIT came from.] 476 */ 477 if (chunk->transport) 478 retval->transport = 479 sctp_assoc_lookup_paddr(asoc, 480 &chunk->transport->ipaddr); 481 482 retval->subh.init_hdr = 483 sctp_addto_chunk(retval, sizeof(initack), &initack); 484 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); 485 sctp_addto_chunk(retval, cookie_len, cookie); 486 if (asoc->peer.ecn_capable) 487 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 488 if (num_ext) { 489 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 490 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext); 491 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); 492 sctp_addto_param(retval, num_ext, extensions); 493 } 494 if (asoc->peer.prsctp_capable) 495 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 496 497 if (sp->adaptation_ind) { 498 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 499 aiparam.param_hdr.length = htons(sizeof(aiparam)); 500 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 501 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 502 } 503 504 if (asoc->peer.auth_capable) { 505 sctp_addto_chunk(retval, ntohs(auth_random->length), 506 auth_random); 507 if (auth_hmacs) 508 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 509 auth_hmacs); 510 if (auth_chunks) 511 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 512 auth_chunks); 513 } 514 515 /* We need to remove the const qualifier at this point. */ 516 retval->asoc = (struct sctp_association *) asoc; 517 518 nomem_chunk: 519 kfree(cookie); 520 nomem_cookie: 521 kfree(addrs.v); 522 return retval; 523 } 524 525 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10): 526 * 527 * This chunk is used only during the initialization of an association. 528 * It is sent by the initiator of an association to its peer to complete 529 * the initialization process. This chunk MUST precede any DATA chunk 530 * sent within the association, but MAY be bundled with one or more DATA 531 * chunks in the same packet. 532 * 533 * 0 1 2 3 534 * 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 1 535 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 536 * | Type = 10 |Chunk Flags | Length | 537 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 538 * / Cookie / 539 * \ \ 540 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 541 * 542 * Chunk Flags: 8 bit 543 * 544 * Set to zero on transmit and ignored on receipt. 545 * 546 * Length: 16 bits (unsigned integer) 547 * 548 * Set to the size of the chunk in bytes, including the 4 bytes of 549 * the chunk header and the size of the Cookie. 550 * 551 * Cookie: variable size 552 * 553 * This field must contain the exact cookie received in the 554 * State Cookie parameter from the previous INIT ACK. 555 * 556 * An implementation SHOULD make the cookie as small as possible 557 * to insure interoperability. 558 */ 559 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, 560 const struct sctp_chunk *chunk) 561 { 562 struct sctp_chunk *retval; 563 int cookie_len; 564 void *cookie; 565 566 cookie = asoc->peer.cookie; 567 cookie_len = asoc->peer.cookie_len; 568 569 /* Build a cookie echo chunk. */ 570 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0, 571 cookie_len, GFP_ATOMIC); 572 if (!retval) 573 goto nodata; 574 retval->subh.cookie_hdr = 575 sctp_addto_chunk(retval, cookie_len, cookie); 576 577 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 578 * 579 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 580 * HEARTBEAT ACK, * etc.) to the same destination transport 581 * address from which it * received the DATA or control chunk 582 * to which it is replying. 583 * 584 * [COOKIE ECHO back to where the INIT ACK came from.] 585 */ 586 if (chunk) 587 retval->transport = chunk->transport; 588 589 nodata: 590 return retval; 591 } 592 593 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11): 594 * 595 * This chunk is used only during the initialization of an 596 * association. It is used to acknowledge the receipt of a COOKIE 597 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent 598 * within the association, but MAY be bundled with one or more DATA 599 * chunks or SACK chunk in the same SCTP packet. 600 * 601 * 0 1 2 3 602 * 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 1 603 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 604 * | Type = 11 |Chunk Flags | Length = 4 | 605 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 606 * 607 * Chunk Flags: 8 bits 608 * 609 * Set to zero on transmit and ignored on receipt. 610 */ 611 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, 612 const struct sctp_chunk *chunk) 613 { 614 struct sctp_chunk *retval; 615 616 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC); 617 618 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 619 * 620 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 621 * HEARTBEAT ACK, * etc.) to the same destination transport 622 * address from which it * received the DATA or control chunk 623 * to which it is replying. 624 * 625 * [COOKIE ACK back to where the COOKIE ECHO came from.] 626 */ 627 if (retval && chunk && chunk->transport) 628 retval->transport = 629 sctp_assoc_lookup_paddr(asoc, 630 &chunk->transport->ipaddr); 631 632 return retval; 633 } 634 635 /* 636 * Appendix A: Explicit Congestion Notification: 637 * CWR: 638 * 639 * RFC 2481 details a specific bit for a sender to send in the header of 640 * its next outbound TCP segment to indicate to its peer that it has 641 * reduced its congestion window. This is termed the CWR bit. For 642 * SCTP the same indication is made by including the CWR chunk. 643 * This chunk contains one data element, i.e. the TSN number that 644 * was sent in the ECNE chunk. This element represents the lowest 645 * TSN number in the datagram that was originally marked with the 646 * CE bit. 647 * 648 * 0 1 2 3 649 * 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 1 650 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 651 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 | 652 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 653 * | Lowest TSN Number | 654 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 655 * 656 * Note: The CWR is considered a Control chunk. 657 */ 658 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, 659 const __u32 lowest_tsn, 660 const struct sctp_chunk *chunk) 661 { 662 struct sctp_chunk *retval; 663 struct sctp_cwrhdr cwr; 664 665 cwr.lowest_tsn = htonl(lowest_tsn); 666 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0, 667 sizeof(cwr), GFP_ATOMIC); 668 669 if (!retval) 670 goto nodata; 671 672 retval->subh.ecn_cwr_hdr = 673 sctp_addto_chunk(retval, sizeof(cwr), &cwr); 674 675 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 676 * 677 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 678 * HEARTBEAT ACK, * etc.) to the same destination transport 679 * address from which it * received the DATA or control chunk 680 * to which it is replying. 681 * 682 * [Report a reduced congestion window back to where the ECNE 683 * came from.] 684 */ 685 if (chunk) 686 retval->transport = chunk->transport; 687 688 nodata: 689 return retval; 690 } 691 692 /* Make an ECNE chunk. This is a congestion experienced report. */ 693 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, 694 const __u32 lowest_tsn) 695 { 696 struct sctp_chunk *retval; 697 struct sctp_ecnehdr ecne; 698 699 ecne.lowest_tsn = htonl(lowest_tsn); 700 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0, 701 sizeof(ecne), GFP_ATOMIC); 702 if (!retval) 703 goto nodata; 704 retval->subh.ecne_hdr = 705 sctp_addto_chunk(retval, sizeof(ecne), &ecne); 706 707 nodata: 708 return retval; 709 } 710 711 /* Make a DATA chunk for the given association from the provided 712 * parameters. However, do not populate the data payload. 713 */ 714 struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc, 715 const struct sctp_sndrcvinfo *sinfo, 716 int len, __u8 flags, gfp_t gfp) 717 { 718 struct sctp_chunk *retval; 719 struct sctp_datahdr dp; 720 721 /* We assign the TSN as LATE as possible, not here when 722 * creating the chunk. 723 */ 724 memset(&dp, 0, sizeof(dp)); 725 dp.ppid = sinfo->sinfo_ppid; 726 dp.stream = htons(sinfo->sinfo_stream); 727 728 /* Set the flags for an unordered send. */ 729 if (sinfo->sinfo_flags & SCTP_UNORDERED) 730 flags |= SCTP_DATA_UNORDERED; 731 732 retval = sctp_make_data(asoc, flags, sizeof(dp) + len, gfp); 733 if (!retval) 734 return NULL; 735 736 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp); 737 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo)); 738 739 return retval; 740 } 741 742 /* Create a selective ackowledgement (SACK) for the given 743 * association. This reports on which TSN's we've seen to date, 744 * including duplicates and gaps. 745 */ 746 struct sctp_chunk *sctp_make_sack(struct sctp_association *asoc) 747 { 748 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; 749 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; 750 __u16 num_gabs, num_dup_tsns; 751 struct sctp_transport *trans; 752 struct sctp_chunk *retval; 753 struct sctp_sackhdr sack; 754 __u32 ctsn; 755 int len; 756 757 memset(gabs, 0, sizeof(gabs)); 758 ctsn = sctp_tsnmap_get_ctsn(map); 759 760 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn); 761 762 /* How much room is needed in the chunk? */ 763 num_gabs = sctp_tsnmap_num_gabs(map, gabs); 764 num_dup_tsns = sctp_tsnmap_num_dups(map); 765 766 /* Initialize the SACK header. */ 767 sack.cum_tsn_ack = htonl(ctsn); 768 sack.a_rwnd = htonl(asoc->a_rwnd); 769 sack.num_gap_ack_blocks = htons(num_gabs); 770 sack.num_dup_tsns = htons(num_dup_tsns); 771 772 len = sizeof(sack) 773 + sizeof(struct sctp_gap_ack_block) * num_gabs 774 + sizeof(__u32) * num_dup_tsns; 775 776 /* Create the chunk. */ 777 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC); 778 if (!retval) 779 goto nodata; 780 781 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 782 * 783 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 784 * HEARTBEAT ACK, etc.) to the same destination transport 785 * address from which it received the DATA or control chunk to 786 * which it is replying. This rule should also be followed if 787 * the endpoint is bundling DATA chunks together with the 788 * reply chunk. 789 * 790 * However, when acknowledging multiple DATA chunks received 791 * in packets from different source addresses in a single 792 * SACK, the SACK chunk may be transmitted to one of the 793 * destination transport addresses from which the DATA or 794 * control chunks being acknowledged were received. 795 * 796 * [BUG: We do not implement the following paragraph. 797 * Perhaps we should remember the last transport we used for a 798 * SACK and avoid that (if possible) if we have seen any 799 * duplicates. --piggy] 800 * 801 * When a receiver of a duplicate DATA chunk sends a SACK to a 802 * multi- homed endpoint it MAY be beneficial to vary the 803 * destination address and not use the source address of the 804 * DATA chunk. The reason being that receiving a duplicate 805 * from a multi-homed endpoint might indicate that the return 806 * path (as specified in the source address of the DATA chunk) 807 * for the SACK is broken. 808 * 809 * [Send to the address from which we last received a DATA chunk.] 810 */ 811 retval->transport = asoc->peer.last_data_from; 812 813 retval->subh.sack_hdr = 814 sctp_addto_chunk(retval, sizeof(sack), &sack); 815 816 /* Add the gap ack block information. */ 817 if (num_gabs) 818 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, 819 gabs); 820 821 /* Add the duplicate TSN information. */ 822 if (num_dup_tsns) { 823 asoc->stats.idupchunks += num_dup_tsns; 824 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, 825 sctp_tsnmap_get_dups(map)); 826 } 827 /* Once we have a sack generated, check to see what our sack 828 * generation is, if its 0, reset the transports to 0, and reset 829 * the association generation to 1 830 * 831 * The idea is that zero is never used as a valid generation for the 832 * association so no transport will match after a wrap event like this, 833 * Until the next sack 834 */ 835 if (++asoc->peer.sack_generation == 0) { 836 list_for_each_entry(trans, &asoc->peer.transport_addr_list, 837 transports) 838 trans->sack_generation = 0; 839 asoc->peer.sack_generation = 1; 840 } 841 nodata: 842 return retval; 843 } 844 845 /* Make a SHUTDOWN chunk. */ 846 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 847 const struct sctp_chunk *chunk) 848 { 849 struct sctp_shutdownhdr shut; 850 struct sctp_chunk *retval; 851 __u32 ctsn; 852 853 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 854 shut.cum_tsn_ack = htonl(ctsn); 855 856 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0, 857 sizeof(shut), GFP_ATOMIC); 858 if (!retval) 859 goto nodata; 860 861 retval->subh.shutdown_hdr = 862 sctp_addto_chunk(retval, sizeof(shut), &shut); 863 864 if (chunk) 865 retval->transport = chunk->transport; 866 nodata: 867 return retval; 868 } 869 870 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 871 const struct sctp_chunk *chunk) 872 { 873 struct sctp_chunk *retval; 874 875 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0, 876 GFP_ATOMIC); 877 878 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 879 * 880 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 881 * HEARTBEAT ACK, * etc.) to the same destination transport 882 * address from which it * received the DATA or control chunk 883 * to which it is replying. 884 * 885 * [ACK back to where the SHUTDOWN came from.] 886 */ 887 if (retval && chunk) 888 retval->transport = chunk->transport; 889 890 return retval; 891 } 892 893 struct sctp_chunk *sctp_make_shutdown_complete( 894 const struct sctp_association *asoc, 895 const struct sctp_chunk *chunk) 896 { 897 struct sctp_chunk *retval; 898 __u8 flags = 0; 899 900 /* Set the T-bit if we have no association (vtag will be 901 * reflected) 902 */ 903 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; 904 905 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 906 0, GFP_ATOMIC); 907 908 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 909 * 910 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 911 * HEARTBEAT ACK, * etc.) to the same destination transport 912 * address from which it * received the DATA or control chunk 913 * to which it is replying. 914 * 915 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK 916 * came from.] 917 */ 918 if (retval && chunk) 919 retval->transport = chunk->transport; 920 921 return retval; 922 } 923 924 /* Create an ABORT. Note that we set the T bit if we have no 925 * association, except when responding to an INIT (sctpimpguide 2.41). 926 */ 927 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 928 const struct sctp_chunk *chunk, 929 const size_t hint) 930 { 931 struct sctp_chunk *retval; 932 __u8 flags = 0; 933 934 /* Set the T-bit if we have no association and 'chunk' is not 935 * an INIT (vtag will be reflected). 936 */ 937 if (!asoc) { 938 if (chunk && chunk->chunk_hdr && 939 chunk->chunk_hdr->type == SCTP_CID_INIT) 940 flags = 0; 941 else 942 flags = SCTP_CHUNK_FLAG_T; 943 } 944 945 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint, 946 GFP_ATOMIC); 947 948 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 949 * 950 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 951 * HEARTBEAT ACK, * etc.) to the same destination transport 952 * address from which it * received the DATA or control chunk 953 * to which it is replying. 954 * 955 * [ABORT back to where the offender came from.] 956 */ 957 if (retval && chunk) 958 retval->transport = chunk->transport; 959 960 return retval; 961 } 962 963 /* Helper to create ABORT with a NO_USER_DATA error. */ 964 struct sctp_chunk *sctp_make_abort_no_data( 965 const struct sctp_association *asoc, 966 const struct sctp_chunk *chunk, 967 __u32 tsn) 968 { 969 struct sctp_chunk *retval; 970 __be32 payload; 971 972 retval = sctp_make_abort(asoc, chunk, 973 sizeof(struct sctp_errhdr) + sizeof(tsn)); 974 975 if (!retval) 976 goto no_mem; 977 978 /* Put the tsn back into network byte order. */ 979 payload = htonl(tsn); 980 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload)); 981 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload); 982 983 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 984 * 985 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 986 * HEARTBEAT ACK, * etc.) to the same destination transport 987 * address from which it * received the DATA or control chunk 988 * to which it is replying. 989 * 990 * [ABORT back to where the offender came from.] 991 */ 992 if (chunk) 993 retval->transport = chunk->transport; 994 995 no_mem: 996 return retval; 997 } 998 999 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ 1000 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 1001 struct msghdr *msg, 1002 size_t paylen) 1003 { 1004 struct sctp_chunk *retval; 1005 void *payload = NULL; 1006 int err; 1007 1008 retval = sctp_make_abort(asoc, NULL, 1009 sizeof(struct sctp_errhdr) + paylen); 1010 if (!retval) 1011 goto err_chunk; 1012 1013 if (paylen) { 1014 /* Put the msg_iov together into payload. */ 1015 payload = kmalloc(paylen, GFP_KERNEL); 1016 if (!payload) 1017 goto err_payload; 1018 1019 err = memcpy_from_msg(payload, msg, paylen); 1020 if (err < 0) 1021 goto err_copy; 1022 } 1023 1024 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); 1025 sctp_addto_chunk(retval, paylen, payload); 1026 1027 if (paylen) 1028 kfree(payload); 1029 1030 return retval; 1031 1032 err_copy: 1033 kfree(payload); 1034 err_payload: 1035 sctp_chunk_free(retval); 1036 retval = NULL; 1037 err_chunk: 1038 return retval; 1039 } 1040 1041 /* Append bytes to the end of a parameter. Will panic if chunk is not big 1042 * enough. 1043 */ 1044 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 1045 const void *data) 1046 { 1047 int chunklen = ntohs(chunk->chunk_hdr->length); 1048 void *target; 1049 1050 target = skb_put(chunk->skb, len); 1051 1052 if (data) 1053 memcpy(target, data, len); 1054 else 1055 memset(target, 0, len); 1056 1057 /* Adjust the chunk length field. */ 1058 chunk->chunk_hdr->length = htons(chunklen + len); 1059 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1060 1061 return target; 1062 } 1063 1064 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ 1065 struct sctp_chunk *sctp_make_abort_violation( 1066 const struct sctp_association *asoc, 1067 const struct sctp_chunk *chunk, 1068 const __u8 *payload, 1069 const size_t paylen) 1070 { 1071 struct sctp_chunk *retval; 1072 struct sctp_paramhdr phdr; 1073 1074 retval = sctp_make_abort(asoc, chunk, sizeof(struct sctp_errhdr) + 1075 paylen + sizeof(phdr)); 1076 if (!retval) 1077 goto end; 1078 1079 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen + 1080 sizeof(phdr)); 1081 1082 phdr.type = htons(chunk->chunk_hdr->type); 1083 phdr.length = chunk->chunk_hdr->length; 1084 sctp_addto_chunk(retval, paylen, payload); 1085 sctp_addto_param(retval, sizeof(phdr), &phdr); 1086 1087 end: 1088 return retval; 1089 } 1090 1091 struct sctp_chunk *sctp_make_violation_paramlen( 1092 const struct sctp_association *asoc, 1093 const struct sctp_chunk *chunk, 1094 struct sctp_paramhdr *param) 1095 { 1096 static const char error[] = "The following parameter had invalid length:"; 1097 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr) + 1098 sizeof(*param); 1099 struct sctp_chunk *retval; 1100 1101 retval = sctp_make_abort(asoc, chunk, payload_len); 1102 if (!retval) 1103 goto nodata; 1104 1105 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, 1106 sizeof(error) + sizeof(*param)); 1107 sctp_addto_chunk(retval, sizeof(error), error); 1108 sctp_addto_param(retval, sizeof(*param), param); 1109 1110 nodata: 1111 return retval; 1112 } 1113 1114 struct sctp_chunk *sctp_make_violation_max_retrans( 1115 const struct sctp_association *asoc, 1116 const struct sctp_chunk *chunk) 1117 { 1118 static const char error[] = "Association exceeded its max_retrans count"; 1119 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr); 1120 struct sctp_chunk *retval; 1121 1122 retval = sctp_make_abort(asoc, chunk, payload_len); 1123 if (!retval) 1124 goto nodata; 1125 1126 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error)); 1127 sctp_addto_chunk(retval, sizeof(error), error); 1128 1129 nodata: 1130 return retval; 1131 } 1132 1133 struct sctp_chunk *sctp_make_new_encap_port(const struct sctp_association *asoc, 1134 const struct sctp_chunk *chunk) 1135 { 1136 struct sctp_new_encap_port_hdr nep; 1137 struct sctp_chunk *retval; 1138 1139 retval = sctp_make_abort(asoc, chunk, 1140 sizeof(struct sctp_errhdr) + sizeof(nep)); 1141 if (!retval) 1142 goto nodata; 1143 1144 sctp_init_cause(retval, SCTP_ERROR_NEW_ENCAP_PORT, sizeof(nep)); 1145 nep.cur_port = SCTP_INPUT_CB(chunk->skb)->encap_port; 1146 nep.new_port = chunk->transport->encap_port; 1147 sctp_addto_chunk(retval, sizeof(nep), &nep); 1148 1149 nodata: 1150 return retval; 1151 } 1152 1153 /* Make a HEARTBEAT chunk. */ 1154 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1155 const struct sctp_transport *transport, 1156 __u32 probe_size) 1157 { 1158 struct sctp_sender_hb_info hbinfo = {}; 1159 struct sctp_chunk *retval; 1160 1161 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, 1162 sizeof(hbinfo), GFP_ATOMIC); 1163 1164 if (!retval) 1165 goto nodata; 1166 1167 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; 1168 hbinfo.param_hdr.length = htons(sizeof(hbinfo)); 1169 hbinfo.daddr = transport->ipaddr; 1170 hbinfo.sent_at = jiffies; 1171 hbinfo.hb_nonce = transport->hb_nonce; 1172 hbinfo.probe_size = probe_size; 1173 1174 /* Cast away the 'const', as this is just telling the chunk 1175 * what transport it belongs to. 1176 */ 1177 retval->transport = (struct sctp_transport *) transport; 1178 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo), 1179 &hbinfo); 1180 retval->pmtu_probe = !!probe_size; 1181 1182 nodata: 1183 return retval; 1184 } 1185 1186 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1187 const struct sctp_chunk *chunk, 1188 const void *payload, 1189 const size_t paylen) 1190 { 1191 struct sctp_chunk *retval; 1192 1193 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen, 1194 GFP_ATOMIC); 1195 if (!retval) 1196 goto nodata; 1197 1198 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1199 1200 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1201 * 1202 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1203 * HEARTBEAT ACK, * etc.) to the same destination transport 1204 * address from which it * received the DATA or control chunk 1205 * to which it is replying. 1206 * 1207 * [HBACK back to where the HEARTBEAT came from.] 1208 */ 1209 if (chunk) 1210 retval->transport = chunk->transport; 1211 1212 nodata: 1213 return retval; 1214 } 1215 1216 /* RFC4820 3. Padding Chunk (PAD) 1217 * 0 1 2 3 1218 * 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 1219 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1220 * | Type = 0x84 | Flags=0 | Length | 1221 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1222 * | | 1223 * \ Padding Data / 1224 * / \ 1225 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1226 */ 1227 struct sctp_chunk *sctp_make_pad(const struct sctp_association *asoc, int len) 1228 { 1229 struct sctp_chunk *retval; 1230 1231 retval = sctp_make_control(asoc, SCTP_CID_PAD, 0, len, GFP_ATOMIC); 1232 if (!retval) 1233 return NULL; 1234 1235 skb_put_zero(retval->skb, len); 1236 retval->chunk_hdr->length = htons(ntohs(retval->chunk_hdr->length) + len); 1237 retval->chunk_end = skb_tail_pointer(retval->skb); 1238 1239 return retval; 1240 } 1241 1242 /* Create an Operation Error chunk with the specified space reserved. 1243 * This routine can be used for containing multiple causes in the chunk. 1244 */ 1245 static struct sctp_chunk *sctp_make_op_error_space( 1246 const struct sctp_association *asoc, 1247 const struct sctp_chunk *chunk, 1248 size_t size) 1249 { 1250 struct sctp_chunk *retval; 1251 1252 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0, 1253 sizeof(struct sctp_errhdr) + size, 1254 GFP_ATOMIC); 1255 if (!retval) 1256 goto nodata; 1257 1258 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1259 * 1260 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1261 * HEARTBEAT ACK, etc.) to the same destination transport 1262 * address from which it received the DATA or control chunk 1263 * to which it is replying. 1264 * 1265 */ 1266 if (chunk) 1267 retval->transport = chunk->transport; 1268 1269 nodata: 1270 return retval; 1271 } 1272 1273 /* Create an Operation Error chunk of a fixed size, specifically, 1274 * min(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) - overheads. 1275 * This is a helper function to allocate an error chunk for those 1276 * invalid parameter codes in which we may not want to report all the 1277 * errors, if the incoming chunk is large. If it can't fit in a single 1278 * packet, we ignore it. 1279 */ 1280 static inline struct sctp_chunk *sctp_make_op_error_limited( 1281 const struct sctp_association *asoc, 1282 const struct sctp_chunk *chunk) 1283 { 1284 size_t size = SCTP_DEFAULT_MAXSEGMENT; 1285 struct sctp_sock *sp = NULL; 1286 1287 if (asoc) { 1288 size = min_t(size_t, size, asoc->pathmtu); 1289 sp = sctp_sk(asoc->base.sk); 1290 } 1291 1292 size = sctp_mtu_payload(sp, size, sizeof(struct sctp_errhdr)); 1293 1294 return sctp_make_op_error_space(asoc, chunk, size); 1295 } 1296 1297 /* Create an Operation Error chunk. */ 1298 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1299 const struct sctp_chunk *chunk, 1300 __be16 cause_code, const void *payload, 1301 size_t paylen, size_t reserve_tail) 1302 { 1303 struct sctp_chunk *retval; 1304 1305 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); 1306 if (!retval) 1307 goto nodata; 1308 1309 sctp_init_cause(retval, cause_code, paylen + reserve_tail); 1310 sctp_addto_chunk(retval, paylen, payload); 1311 if (reserve_tail) 1312 sctp_addto_param(retval, reserve_tail, NULL); 1313 1314 nodata: 1315 return retval; 1316 } 1317 1318 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc, 1319 __u16 key_id) 1320 { 1321 struct sctp_authhdr auth_hdr; 1322 const struct sctp_hmac *hmac_desc; 1323 struct sctp_chunk *retval; 1324 1325 /* Get the first hmac that the peer told us to use */ 1326 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1327 if (unlikely(!hmac_desc)) 1328 return NULL; 1329 1330 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0, 1331 hmac_desc->hmac_len + sizeof(auth_hdr), 1332 GFP_ATOMIC); 1333 if (!retval) 1334 return NULL; 1335 1336 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1337 auth_hdr.shkey_id = htons(key_id); 1338 1339 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr), 1340 &auth_hdr); 1341 1342 skb_put_zero(retval->skb, hmac_desc->hmac_len); 1343 1344 /* Adjust the chunk header to include the empty MAC */ 1345 retval->chunk_hdr->length = 1346 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1347 retval->chunk_end = skb_tail_pointer(retval->skb); 1348 1349 return retval; 1350 } 1351 1352 1353 /******************************************************************** 1354 * 2nd Level Abstractions 1355 ********************************************************************/ 1356 1357 /* Turn an skb into a chunk. 1358 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1359 * 1360 * sctpimpguide-05.txt Section 2.8.2 1361 * M1) Each time a new DATA chunk is transmitted 1362 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1363 * 'TSN.Missing.Report' count will be used to determine missing chunks 1364 * and when to fast retransmit. 1365 * 1366 */ 1367 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1368 const struct sctp_association *asoc, 1369 struct sock *sk, gfp_t gfp) 1370 { 1371 struct sctp_chunk *retval; 1372 1373 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp); 1374 1375 if (!retval) 1376 goto nodata; 1377 if (!sk) 1378 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb); 1379 1380 INIT_LIST_HEAD(&retval->list); 1381 retval->skb = skb; 1382 retval->asoc = (struct sctp_association *)asoc; 1383 retval->singleton = 1; 1384 1385 retval->fast_retransmit = SCTP_CAN_FRTX; 1386 1387 /* Polish the bead hole. */ 1388 INIT_LIST_HEAD(&retval->transmitted_list); 1389 INIT_LIST_HEAD(&retval->frag_list); 1390 SCTP_DBG_OBJCNT_INC(chunk); 1391 refcount_set(&retval->refcnt, 1); 1392 1393 nodata: 1394 return retval; 1395 } 1396 1397 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1398 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1399 union sctp_addr *dest) 1400 { 1401 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1402 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1403 } 1404 1405 /* Extract the source address from a chunk. */ 1406 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1407 { 1408 /* If we have a known transport, use that. */ 1409 if (chunk->transport) { 1410 return &chunk->transport->ipaddr; 1411 } else { 1412 /* Otherwise, extract it from the IP header. */ 1413 return &chunk->source; 1414 } 1415 } 1416 1417 /* Create a new chunk, setting the type and flags headers from the 1418 * arguments, reserving enough space for a 'paylen' byte payload. 1419 */ 1420 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 1421 __u8 type, __u8 flags, int paylen, 1422 gfp_t gfp) 1423 { 1424 struct sctp_chunkhdr *chunk_hdr; 1425 struct sctp_chunk *retval; 1426 struct sk_buff *skb; 1427 struct sock *sk; 1428 int chunklen; 1429 1430 chunklen = SCTP_PAD4(sizeof(*chunk_hdr) + paylen); 1431 if (chunklen > SCTP_MAX_CHUNK_LEN) 1432 goto nodata; 1433 1434 /* No need to allocate LL here, as this is only a chunk. */ 1435 skb = alloc_skb(chunklen, gfp); 1436 if (!skb) 1437 goto nodata; 1438 1439 /* Make room for the chunk header. */ 1440 chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr)); 1441 chunk_hdr->type = type; 1442 chunk_hdr->flags = flags; 1443 chunk_hdr->length = htons(sizeof(*chunk_hdr)); 1444 1445 sk = asoc ? asoc->base.sk : NULL; 1446 retval = sctp_chunkify(skb, asoc, sk, gfp); 1447 if (!retval) { 1448 kfree_skb(skb); 1449 goto nodata; 1450 } 1451 1452 retval->chunk_hdr = chunk_hdr; 1453 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr); 1454 1455 /* Determine if the chunk needs to be authenticated */ 1456 if (sctp_auth_send_cid(type, asoc)) 1457 retval->auth = 1; 1458 1459 return retval; 1460 nodata: 1461 return NULL; 1462 } 1463 1464 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 1465 __u8 flags, int paylen, gfp_t gfp) 1466 { 1467 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp); 1468 } 1469 1470 struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc, 1471 __u8 flags, int paylen, gfp_t gfp) 1472 { 1473 return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp); 1474 } 1475 1476 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 1477 __u8 type, __u8 flags, int paylen, 1478 gfp_t gfp) 1479 { 1480 struct sctp_chunk *chunk; 1481 1482 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp); 1483 if (chunk) 1484 sctp_control_set_owner_w(chunk); 1485 1486 return chunk; 1487 } 1488 1489 /* Release the memory occupied by a chunk. */ 1490 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1491 { 1492 BUG_ON(!list_empty(&chunk->list)); 1493 list_del_init(&chunk->transmitted_list); 1494 1495 consume_skb(chunk->skb); 1496 consume_skb(chunk->auth_chunk); 1497 1498 SCTP_DBG_OBJCNT_DEC(chunk); 1499 kmem_cache_free(sctp_chunk_cachep, chunk); 1500 } 1501 1502 /* Possibly, free the chunk. */ 1503 void sctp_chunk_free(struct sctp_chunk *chunk) 1504 { 1505 /* Release our reference on the message tracker. */ 1506 if (chunk->msg) 1507 sctp_datamsg_put(chunk->msg); 1508 1509 sctp_chunk_put(chunk); 1510 } 1511 1512 /* Grab a reference to the chunk. */ 1513 void sctp_chunk_hold(struct sctp_chunk *ch) 1514 { 1515 refcount_inc(&ch->refcnt); 1516 } 1517 1518 /* Release a reference to the chunk. */ 1519 void sctp_chunk_put(struct sctp_chunk *ch) 1520 { 1521 if (refcount_dec_and_test(&ch->refcnt)) 1522 sctp_chunk_destroy(ch); 1523 } 1524 1525 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1526 * enough. 1527 */ 1528 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1529 { 1530 int chunklen = ntohs(chunk->chunk_hdr->length); 1531 int padlen = SCTP_PAD4(chunklen) - chunklen; 1532 void *target; 1533 1534 skb_put_zero(chunk->skb, padlen); 1535 target = skb_put_data(chunk->skb, data, len); 1536 1537 /* Adjust the chunk length field. */ 1538 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1539 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1540 1541 return target; 1542 } 1543 1544 /* Append bytes from user space to the end of a chunk. Will panic if 1545 * chunk is not big enough. 1546 * Returns a kernel err value. 1547 */ 1548 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len, 1549 struct iov_iter *from) 1550 { 1551 void *target; 1552 1553 /* Make room in chunk for data. */ 1554 target = skb_put(chunk->skb, len); 1555 1556 /* Copy data (whole iovec) into chunk */ 1557 if (!copy_from_iter_full(target, len, from)) 1558 return -EFAULT; 1559 1560 /* Adjust the chunk length field. */ 1561 chunk->chunk_hdr->length = 1562 htons(ntohs(chunk->chunk_hdr->length) + len); 1563 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1564 1565 return 0; 1566 } 1567 1568 /* Helper function to assign a TSN if needed. This assumes that both 1569 * the data_hdr and association have already been assigned. 1570 */ 1571 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1572 { 1573 struct sctp_stream *stream; 1574 struct sctp_chunk *lchunk; 1575 struct sctp_datamsg *msg; 1576 __u16 ssn, sid; 1577 1578 if (chunk->has_ssn) 1579 return; 1580 1581 /* All fragments will be on the same stream */ 1582 sid = ntohs(chunk->subh.data_hdr->stream); 1583 stream = &chunk->asoc->stream; 1584 1585 /* Now assign the sequence number to the entire message. 1586 * All fragments must have the same stream sequence number. 1587 */ 1588 msg = chunk->msg; 1589 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1590 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1591 ssn = 0; 1592 } else { 1593 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1594 ssn = sctp_ssn_next(stream, out, sid); 1595 else 1596 ssn = sctp_ssn_peek(stream, out, sid); 1597 } 1598 1599 lchunk->subh.data_hdr->ssn = htons(ssn); 1600 lchunk->has_ssn = 1; 1601 } 1602 } 1603 1604 /* Helper function to assign a TSN if needed. This assumes that both 1605 * the data_hdr and association have already been assigned. 1606 */ 1607 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1608 { 1609 if (!chunk->has_tsn) { 1610 /* This is the last possible instant to 1611 * assign a TSN. 1612 */ 1613 chunk->subh.data_hdr->tsn = 1614 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1615 chunk->has_tsn = 1; 1616 } 1617 } 1618 1619 /* Create a CLOSED association to use with an incoming packet. */ 1620 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1621 struct sctp_chunk *chunk, 1622 gfp_t gfp) 1623 { 1624 struct sctp_association *asoc; 1625 enum sctp_scope scope; 1626 struct sk_buff *skb; 1627 1628 /* Create the bare association. */ 1629 scope = sctp_scope(sctp_source(chunk)); 1630 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1631 if (!asoc) 1632 goto nodata; 1633 asoc->temp = 1; 1634 skb = chunk->skb; 1635 /* Create an entry for the source address of the packet. */ 1636 SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1); 1637 1638 nodata: 1639 return asoc; 1640 } 1641 1642 /* Build a cookie representing asoc. 1643 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1644 */ 1645 static struct sctp_cookie_param *sctp_pack_cookie( 1646 const struct sctp_endpoint *ep, 1647 const struct sctp_association *asoc, 1648 const struct sctp_chunk *init_chunk, 1649 int *cookie_len, const __u8 *raw_addrs, 1650 int addrs_len) 1651 { 1652 struct sctp_signed_cookie *cookie; 1653 struct sctp_cookie_param *retval; 1654 int headersize, bodysize; 1655 1656 /* Header size is static data prior to the actual cookie, including 1657 * any padding. 1658 */ 1659 headersize = sizeof(struct sctp_paramhdr) + 1660 (sizeof(struct sctp_signed_cookie) - 1661 sizeof(struct sctp_cookie)); 1662 bodysize = sizeof(struct sctp_cookie) 1663 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1664 1665 /* Pad out the cookie to a multiple to make the signature 1666 * functions simpler to write. 1667 */ 1668 if (bodysize % SCTP_COOKIE_MULTIPLE) 1669 bodysize += SCTP_COOKIE_MULTIPLE 1670 - (bodysize % SCTP_COOKIE_MULTIPLE); 1671 *cookie_len = headersize + bodysize; 1672 1673 /* Clear this memory since we are sending this data structure 1674 * out on the network. 1675 */ 1676 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1677 if (!retval) { 1678 *cookie_len = 0; 1679 return NULL; 1680 } 1681 1682 cookie = (struct sctp_signed_cookie *) retval->body; 1683 1684 /* Set up the parameter header. */ 1685 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1686 retval->p.length = htons(*cookie_len); 1687 1688 /* Copy the cookie part of the association itself. */ 1689 cookie->c = asoc->c; 1690 /* Save the raw address list length in the cookie. */ 1691 cookie->c.raw_addr_list_len = addrs_len; 1692 1693 /* Remember PR-SCTP capability. */ 1694 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1695 1696 /* Save adaptation indication in the cookie. */ 1697 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1698 1699 /* Set an expiration time for the cookie. */ 1700 cookie->c.expiration = ktime_add(asoc->cookie_life, 1701 ktime_get_real()); 1702 1703 /* Copy the peer's init packet. */ 1704 memcpy(cookie + 1, init_chunk->chunk_hdr, 1705 ntohs(init_chunk->chunk_hdr->length)); 1706 1707 /* Copy the raw local address list of the association. */ 1708 memcpy((__u8 *)(cookie + 1) + 1709 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1710 1711 /* Sign the cookie, if cookie authentication is enabled. */ 1712 if (sctp_sk(ep->base.sk)->cookie_auth_enable) { 1713 static_assert(sizeof(cookie->mac) == SHA256_DIGEST_SIZE); 1714 hmac_sha256(&ep->cookie_auth_key, (const u8 *)&cookie->c, 1715 bodysize, cookie->mac); 1716 } 1717 1718 return retval; 1719 } 1720 1721 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1722 struct sctp_association *sctp_unpack_cookie( 1723 const struct sctp_endpoint *ep, 1724 const struct sctp_association *asoc, 1725 struct sctp_chunk *chunk, gfp_t gfp, 1726 int *error, struct sctp_chunk **errp) 1727 { 1728 struct sctp_association *retval = NULL; 1729 int headersize, bodysize, fixed_size; 1730 struct sctp_signed_cookie *cookie; 1731 struct sk_buff *skb = chunk->skb; 1732 struct sctp_cookie *bear_cookie; 1733 struct sctp_chunkhdr *ch; 1734 unsigned int len, chlen; 1735 enum sctp_scope scope; 1736 ktime_t kt; 1737 1738 /* Header size is static data prior to the actual cookie, including 1739 * any padding. 1740 */ 1741 headersize = sizeof(struct sctp_chunkhdr) + 1742 (sizeof(struct sctp_signed_cookie) - 1743 sizeof(struct sctp_cookie)); 1744 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1745 fixed_size = headersize + sizeof(struct sctp_cookie); 1746 1747 /* Verify that the chunk looks like it even has a cookie. 1748 * There must be enough room for our cookie and our peer's 1749 * INIT chunk. 1750 */ 1751 len = ntohs(chunk->chunk_hdr->length); 1752 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1753 goto malformed; 1754 1755 /* Verify that the cookie has been padded out. */ 1756 if (bodysize % SCTP_COOKIE_MULTIPLE) 1757 goto malformed; 1758 1759 /* Process the cookie. */ 1760 cookie = chunk->subh.cookie_hdr; 1761 bear_cookie = &cookie->c; 1762 1763 ch = (struct sctp_chunkhdr *)(bear_cookie + 1); 1764 chlen = ntohs(ch->length); 1765 if (chlen < sizeof(struct sctp_init_chunk)) 1766 goto malformed; 1767 if (chlen > len - fixed_size) 1768 goto malformed; 1769 if (bear_cookie->raw_addr_list_len > len - fixed_size - chlen) 1770 goto malformed; 1771 1772 /* Verify the cookie's MAC, if cookie authentication is enabled. */ 1773 if (sctp_sk(ep->base.sk)->cookie_auth_enable) { 1774 u8 mac[SHA256_DIGEST_SIZE]; 1775 1776 hmac_sha256(&ep->cookie_auth_key, (const u8 *)bear_cookie, 1777 bodysize, mac); 1778 static_assert(sizeof(cookie->mac) == sizeof(mac)); 1779 if (crypto_memneq(mac, cookie->mac, sizeof(mac))) { 1780 *error = -SCTP_IERROR_BAD_SIG; 1781 goto fail; 1782 } 1783 } 1784 1785 /* IG Section 2.35.2: 1786 * 3) Compare the port numbers and the verification tag contained 1787 * within the COOKIE ECHO chunk to the actual port numbers and the 1788 * verification tag within the SCTP common header of the received 1789 * packet. If these values do not match the packet MUST be silently 1790 * discarded, 1791 */ 1792 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1793 *error = -SCTP_IERROR_BAD_TAG; 1794 goto fail; 1795 } 1796 1797 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1798 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1799 *error = -SCTP_IERROR_BAD_PORTS; 1800 goto fail; 1801 } 1802 1803 /* Check to see if the cookie is stale. If there is already 1804 * an association, there is no need to check cookie's expiration 1805 * for init collision case of lost COOKIE ACK. 1806 * If skb has been timestamped, then use the stamp, otherwise 1807 * use current time. This introduces a small possibility that 1808 * a cookie may be considered expired, but this would only slow 1809 * down the new association establishment instead of every packet. 1810 */ 1811 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1812 kt = skb_get_ktime(skb); 1813 else 1814 kt = ktime_get_real(); 1815 1816 if (!asoc && ktime_before(bear_cookie->expiration, kt)) { 1817 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); 1818 __be32 n = htonl(usecs); 1819 1820 /* 1821 * Section 3.3.10.3 Stale Cookie Error (3) 1822 * 1823 * Cause of error 1824 * --------------- 1825 * Stale Cookie Error: Indicates the receipt of a valid State 1826 * Cookie that has expired. 1827 */ 1828 *errp = sctp_make_op_error(asoc, chunk, 1829 SCTP_ERROR_STALE_COOKIE, &n, 1830 sizeof(n), 0); 1831 if (*errp) 1832 *error = -SCTP_IERROR_STALE_COOKIE; 1833 else 1834 *error = -SCTP_IERROR_NOMEM; 1835 1836 goto fail; 1837 } 1838 1839 /* Make a new base association. */ 1840 scope = sctp_scope(sctp_source(chunk)); 1841 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1842 if (!retval) { 1843 *error = -SCTP_IERROR_NOMEM; 1844 goto fail; 1845 } 1846 1847 /* Set up our peer's port number. */ 1848 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1849 1850 /* Populate the association from the cookie. */ 1851 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1852 1853 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1854 GFP_ATOMIC) < 0) { 1855 *error = -SCTP_IERROR_NOMEM; 1856 goto fail; 1857 } 1858 1859 /* Also, add the destination address. */ 1860 if (list_empty(&retval->base.bind_addr.address_list)) { 1861 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1862 sizeof(chunk->dest), SCTP_ADDR_SRC, 1863 GFP_ATOMIC); 1864 } 1865 1866 retval->next_tsn = retval->c.initial_tsn; 1867 retval->ctsn_ack_point = retval->next_tsn - 1; 1868 retval->addip_serial = retval->c.initial_tsn; 1869 retval->strreset_outseq = retval->c.initial_tsn; 1870 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1871 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1872 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1873 1874 /* The INIT stuff will be done by the side effects. */ 1875 return retval; 1876 1877 fail: 1878 if (retval) 1879 sctp_association_free(retval); 1880 1881 return NULL; 1882 1883 malformed: 1884 /* Yikes! The packet is either corrupt or deliberately 1885 * malformed. 1886 */ 1887 *error = -SCTP_IERROR_MALFORMED; 1888 goto fail; 1889 } 1890 1891 /******************************************************************** 1892 * 3rd Level Abstractions 1893 ********************************************************************/ 1894 1895 struct __sctp_missing { 1896 __be32 num_missing; 1897 __be16 type; 1898 } __packed; 1899 1900 /* 1901 * Report a missing mandatory parameter. 1902 */ 1903 static int sctp_process_missing_param(const struct sctp_association *asoc, 1904 enum sctp_param paramtype, 1905 struct sctp_chunk *chunk, 1906 struct sctp_chunk **errp) 1907 { 1908 struct __sctp_missing report; 1909 __u16 len; 1910 1911 len = SCTP_PAD4(sizeof(report)); 1912 1913 /* Make an ERROR chunk, preparing enough room for 1914 * returning multiple unknown parameters. 1915 */ 1916 if (!*errp) 1917 *errp = sctp_make_op_error_space(asoc, chunk, len); 1918 1919 if (*errp) { 1920 report.num_missing = htonl(1); 1921 report.type = paramtype; 1922 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1923 sizeof(report)); 1924 sctp_addto_chunk(*errp, sizeof(report), &report); 1925 } 1926 1927 /* Stop processing this chunk. */ 1928 return 0; 1929 } 1930 1931 /* Report an Invalid Mandatory Parameter. */ 1932 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1933 struct sctp_chunk *chunk, 1934 struct sctp_chunk **errp) 1935 { 1936 /* Invalid Mandatory Parameter Error has no payload. */ 1937 1938 if (!*errp) 1939 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1940 1941 if (*errp) 1942 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1943 1944 /* Stop processing this chunk. */ 1945 return 0; 1946 } 1947 1948 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1949 struct sctp_paramhdr *param, 1950 const struct sctp_chunk *chunk, 1951 struct sctp_chunk **errp) 1952 { 1953 /* This is a fatal error. Any accumulated non-fatal errors are 1954 * not reported. 1955 */ 1956 if (*errp) 1957 sctp_chunk_free(*errp); 1958 1959 /* Create an error chunk and fill it in with our payload. */ 1960 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1961 1962 return 0; 1963 } 1964 1965 1966 /* Do not attempt to handle the HOST_NAME parm. However, do 1967 * send back an indicator to the peer. 1968 */ 1969 static int sctp_process_hn_param(const struct sctp_association *asoc, 1970 union sctp_params param, 1971 struct sctp_chunk *chunk, 1972 struct sctp_chunk **errp) 1973 { 1974 __u16 len = ntohs(param.p->length); 1975 1976 /* Processing of the HOST_NAME parameter will generate an 1977 * ABORT. If we've accumulated any non-fatal errors, they 1978 * would be unrecognized parameters and we should not include 1979 * them in the ABORT. 1980 */ 1981 if (*errp) 1982 sctp_chunk_free(*errp); 1983 1984 *errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_DNS_FAILED, 1985 param.v, len, 0); 1986 1987 /* Stop processing this chunk. */ 1988 return 0; 1989 } 1990 1991 static int sctp_verify_ext_param(struct net *net, 1992 const struct sctp_endpoint *ep, 1993 union sctp_params param) 1994 { 1995 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 1996 int have_asconf = 0; 1997 int have_auth = 0; 1998 int i; 1999 2000 for (i = 0; i < num_ext; i++) { 2001 switch (param.ext->chunks[i]) { 2002 case SCTP_CID_AUTH: 2003 have_auth = 1; 2004 break; 2005 case SCTP_CID_ASCONF: 2006 case SCTP_CID_ASCONF_ACK: 2007 have_asconf = 1; 2008 break; 2009 } 2010 } 2011 2012 /* ADD-IP Security: The draft requires us to ABORT or ignore the 2013 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 2014 * only if ADD-IP is turned on and we are not backward-compatible 2015 * mode. 2016 */ 2017 if (net->sctp.addip_noauth) 2018 return 1; 2019 2020 if (ep->asconf_enable && !have_auth && have_asconf) 2021 return 0; 2022 2023 return 1; 2024 } 2025 2026 static void sctp_process_ext_param(struct sctp_association *asoc, 2027 union sctp_params param) 2028 { 2029 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2030 int i; 2031 2032 for (i = 0; i < num_ext; i++) { 2033 switch (param.ext->chunks[i]) { 2034 case SCTP_CID_RECONF: 2035 if (asoc->ep->reconf_enable) 2036 asoc->peer.reconf_capable = 1; 2037 break; 2038 case SCTP_CID_FWD_TSN: 2039 if (asoc->ep->prsctp_enable) 2040 asoc->peer.prsctp_capable = 1; 2041 break; 2042 case SCTP_CID_AUTH: 2043 /* if the peer reports AUTH, assume that he 2044 * supports AUTH. 2045 */ 2046 if (asoc->ep->auth_enable) 2047 asoc->peer.auth_capable = 1; 2048 break; 2049 case SCTP_CID_ASCONF: 2050 case SCTP_CID_ASCONF_ACK: 2051 if (asoc->ep->asconf_enable) 2052 asoc->peer.asconf_capable = 1; 2053 break; 2054 case SCTP_CID_I_DATA: 2055 if (asoc->ep->intl_enable) 2056 asoc->peer.intl_capable = 1; 2057 break; 2058 default: 2059 break; 2060 } 2061 } 2062 } 2063 2064 /* RFC 3.2.1 & the Implementers Guide 2.2. 2065 * 2066 * The Parameter Types are encoded such that the 2067 * highest-order two bits specify the action that must be 2068 * taken if the processing endpoint does not recognize the 2069 * Parameter Type. 2070 * 2071 * 00 - Stop processing this parameter; do not process any further 2072 * parameters within this chunk 2073 * 2074 * 01 - Stop processing this parameter, do not process any further 2075 * parameters within this chunk, and report the unrecognized 2076 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2077 * 2078 * 10 - Skip this parameter and continue processing. 2079 * 2080 * 11 - Skip this parameter and continue processing but 2081 * report the unrecognized parameter in an 2082 * 'Unrecognized Parameter' ERROR chunk. 2083 * 2084 * Return value: 2085 * SCTP_IERROR_NO_ERROR - continue with the chunk 2086 * SCTP_IERROR_ERROR - stop and report an error. 2087 * SCTP_IERROR_NOMEME - out of memory. 2088 */ 2089 static enum sctp_ierror sctp_process_unk_param( 2090 const struct sctp_association *asoc, 2091 union sctp_params param, 2092 struct sctp_chunk *chunk, 2093 struct sctp_chunk **errp) 2094 { 2095 int retval = SCTP_IERROR_NO_ERROR; 2096 2097 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2098 case SCTP_PARAM_ACTION_DISCARD: 2099 retval = SCTP_IERROR_ERROR; 2100 break; 2101 case SCTP_PARAM_ACTION_SKIP: 2102 break; 2103 case SCTP_PARAM_ACTION_DISCARD_ERR: 2104 retval = SCTP_IERROR_ERROR; 2105 fallthrough; 2106 case SCTP_PARAM_ACTION_SKIP_ERR: 2107 /* Make an ERROR chunk, preparing enough room for 2108 * returning multiple unknown parameters. 2109 */ 2110 if (!*errp) { 2111 *errp = sctp_make_op_error_limited(asoc, chunk); 2112 if (!*errp) { 2113 /* If there is no memory for generating the 2114 * ERROR report as specified, an ABORT will be 2115 * triggered to the peer and the association 2116 * won't be established. 2117 */ 2118 retval = SCTP_IERROR_NOMEM; 2119 break; 2120 } 2121 } 2122 2123 if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2124 ntohs(param.p->length))) 2125 sctp_addto_chunk(*errp, ntohs(param.p->length), 2126 param.v); 2127 break; 2128 default: 2129 break; 2130 } 2131 2132 return retval; 2133 } 2134 2135 /* Verify variable length parameters 2136 * Return values: 2137 * SCTP_IERROR_ABORT - trigger an ABORT 2138 * SCTP_IERROR_NOMEM - out of memory (abort) 2139 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2140 * SCTP_IERROR_NO_ERROR - continue with the chunk 2141 */ 2142 static enum sctp_ierror sctp_verify_param(struct net *net, 2143 const struct sctp_endpoint *ep, 2144 const struct sctp_association *asoc, 2145 union sctp_params param, 2146 enum sctp_cid cid, 2147 struct sctp_chunk *chunk, 2148 struct sctp_chunk **err_chunk) 2149 { 2150 struct sctp_hmac_algo_param *hmacs; 2151 int retval = SCTP_IERROR_NO_ERROR; 2152 __u16 n_elt, id = 0; 2153 int i; 2154 2155 /* FIXME - This routine is not looking at each parameter per the 2156 * chunk type, i.e., unrecognized parameters should be further 2157 * identified based on the chunk id. 2158 */ 2159 2160 switch (param.p->type) { 2161 case SCTP_PARAM_IPV4_ADDRESS: 2162 case SCTP_PARAM_IPV6_ADDRESS: 2163 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2164 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2165 case SCTP_PARAM_STATE_COOKIE: 2166 case SCTP_PARAM_HEARTBEAT_INFO: 2167 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2168 case SCTP_PARAM_ECN_CAPABLE: 2169 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2170 break; 2171 2172 case SCTP_PARAM_SUPPORTED_EXT: 2173 if (!sctp_verify_ext_param(net, ep, param)) 2174 return SCTP_IERROR_ABORT; 2175 break; 2176 2177 case SCTP_PARAM_SET_PRIMARY: 2178 if (!ep->asconf_enable) 2179 goto unhandled; 2180 2181 if (ntohs(param.p->length) < sizeof(struct sctp_addip_param) + 2182 sizeof(struct sctp_paramhdr)) { 2183 sctp_process_inv_paramlength(asoc, param.p, 2184 chunk, err_chunk); 2185 retval = SCTP_IERROR_ABORT; 2186 } 2187 break; 2188 2189 case SCTP_PARAM_HOST_NAME_ADDRESS: 2190 /* This param has been Deprecated, send ABORT. */ 2191 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2192 retval = SCTP_IERROR_ABORT; 2193 break; 2194 2195 case SCTP_PARAM_FWD_TSN_SUPPORT: 2196 if (ep->prsctp_enable) 2197 break; 2198 goto unhandled; 2199 2200 case SCTP_PARAM_RANDOM: 2201 if (!ep->auth_enable) 2202 goto unhandled; 2203 2204 /* SCTP-AUTH: Secion 6.1 2205 * If the random number is not 32 byte long the association 2206 * MUST be aborted. The ABORT chunk SHOULD contain the error 2207 * cause 'Protocol Violation'. 2208 */ 2209 if (SCTP_AUTH_RANDOM_LENGTH != ntohs(param.p->length) - 2210 sizeof(struct sctp_paramhdr)) { 2211 sctp_process_inv_paramlength(asoc, param.p, 2212 chunk, err_chunk); 2213 retval = SCTP_IERROR_ABORT; 2214 } 2215 break; 2216 2217 case SCTP_PARAM_CHUNKS: 2218 if (!ep->auth_enable) 2219 goto unhandled; 2220 2221 /* SCTP-AUTH: Section 3.2 2222 * The CHUNKS parameter MUST be included once in the INIT or 2223 * INIT-ACK chunk if the sender wants to receive authenticated 2224 * chunks. Its maximum length is 260 bytes. 2225 */ 2226 if (260 < ntohs(param.p->length)) { 2227 sctp_process_inv_paramlength(asoc, param.p, 2228 chunk, err_chunk); 2229 retval = SCTP_IERROR_ABORT; 2230 } 2231 break; 2232 2233 case SCTP_PARAM_HMAC_ALGO: 2234 if (!ep->auth_enable) 2235 goto unhandled; 2236 2237 hmacs = (struct sctp_hmac_algo_param *)param.p; 2238 n_elt = (ntohs(param.p->length) - 2239 sizeof(struct sctp_paramhdr)) >> 1; 2240 2241 /* SCTP-AUTH: Section 6.1 2242 * The HMAC algorithm based on SHA-1 MUST be supported and 2243 * included in the HMAC-ALGO parameter. 2244 */ 2245 for (i = 0; i < n_elt; i++) { 2246 id = ntohs(hmacs->hmac_ids[i]); 2247 2248 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2249 break; 2250 } 2251 2252 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2253 sctp_process_inv_paramlength(asoc, param.p, chunk, 2254 err_chunk); 2255 retval = SCTP_IERROR_ABORT; 2256 } 2257 break; 2258 unhandled: 2259 default: 2260 pr_debug("%s: unrecognized param:%d for chunk:%d\n", 2261 __func__, ntohs(param.p->type), cid); 2262 2263 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2264 break; 2265 } 2266 return retval; 2267 } 2268 2269 /* Verify the INIT packet before we process it. */ 2270 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 2271 const struct sctp_association *asoc, enum sctp_cid cid, 2272 struct sctp_init_chunk *peer_init, 2273 struct sctp_chunk *chunk, struct sctp_chunk **errp) 2274 { 2275 union sctp_params param; 2276 bool has_cookie = false; 2277 int result; 2278 2279 /* Check for missing mandatory parameters. Note: Initial TSN is 2280 * also mandatory, but is not checked here since the valid range 2281 * is 0..2**32-1. RFC4960, section 3.3.3. 2282 */ 2283 if (peer_init->init_hdr.num_outbound_streams == 0 || 2284 peer_init->init_hdr.num_inbound_streams == 0 || 2285 peer_init->init_hdr.init_tag == 0 || 2286 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) 2287 return sctp_process_inv_mandatory(asoc, chunk, errp); 2288 2289 sctp_walk_params(param, peer_init) { 2290 if (param.p->type == SCTP_PARAM_STATE_COOKIE) 2291 has_cookie = true; 2292 } 2293 2294 /* There is a possibility that a parameter length was bad and 2295 * in that case we would have stoped walking the parameters. 2296 * The current param.p would point at the bad one. 2297 * Current consensus on the mailing list is to generate a PROTOCOL 2298 * VIOLATION error. We build the ERROR chunk here and let the normal 2299 * error handling code build and send the packet. 2300 */ 2301 if (param.v != (void *)chunk->chunk_end) 2302 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2303 2304 /* The only missing mandatory param possible today is 2305 * the state cookie for an INIT-ACK chunk. 2306 */ 2307 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2308 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2309 chunk, errp); 2310 2311 /* Verify all the variable length parameters */ 2312 sctp_walk_params(param, peer_init) { 2313 result = sctp_verify_param(net, ep, asoc, param, cid, 2314 chunk, errp); 2315 switch (result) { 2316 case SCTP_IERROR_ABORT: 2317 case SCTP_IERROR_NOMEM: 2318 return 0; 2319 case SCTP_IERROR_ERROR: 2320 return 1; 2321 case SCTP_IERROR_NO_ERROR: 2322 default: 2323 break; 2324 } 2325 2326 } /* for (loop through all parameters) */ 2327 2328 return 1; 2329 } 2330 2331 /* Unpack the parameters in an INIT packet into an association. 2332 * Returns 0 on failure, else success. 2333 * FIXME: This is an association method. 2334 */ 2335 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2336 const union sctp_addr *peer_addr, 2337 struct sctp_init_chunk *peer_init, gfp_t gfp) 2338 { 2339 struct sctp_transport *transport; 2340 struct list_head *pos, *temp; 2341 union sctp_params param; 2342 union sctp_addr addr; 2343 struct sctp_af *af; 2344 int src_match = 0; 2345 2346 /* We must include the address that the INIT packet came from. 2347 * This is the only address that matters for an INIT packet. 2348 * When processing a COOKIE ECHO, we retrieve the from address 2349 * of the INIT from the cookie. 2350 */ 2351 2352 /* This implementation defaults to making the first transport 2353 * added as the primary transport. The source address seems to 2354 * be a better choice than any of the embedded addresses. 2355 */ 2356 asoc->encap_port = SCTP_INPUT_CB(chunk->skb)->encap_port; 2357 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2358 goto nomem; 2359 2360 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2361 src_match = 1; 2362 2363 /* Process the initialization parameters. */ 2364 sctp_walk_params(param, peer_init) { 2365 if (!src_match && 2366 (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2367 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2368 af = sctp_get_af_specific(param_type2af(param.p->type)); 2369 if (!af->from_addr_param(&addr, param.addr, 2370 chunk->sctp_hdr->source, 0)) 2371 continue; 2372 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2373 src_match = 1; 2374 } 2375 2376 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2377 goto clean_up; 2378 } 2379 2380 /* source address of chunk may not match any valid address */ 2381 if (!src_match) 2382 goto clean_up; 2383 2384 /* AUTH: After processing the parameters, make sure that we 2385 * have all the required info to potentially do authentications. 2386 */ 2387 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2388 !asoc->peer.peer_hmacs)) 2389 asoc->peer.auth_capable = 0; 2390 2391 /* In a non-backward compatible mode, if the peer claims 2392 * support for ADD-IP but not AUTH, the ADD-IP spec states 2393 * that we MUST ABORT the association. Section 6. The section 2394 * also give us an option to silently ignore the packet, which 2395 * is what we'll do here. 2396 */ 2397 if (!asoc->base.net->sctp.addip_noauth && 2398 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2399 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2400 SCTP_PARAM_DEL_IP | 2401 SCTP_PARAM_SET_PRIMARY); 2402 asoc->peer.asconf_capable = 0; 2403 goto clean_up; 2404 } 2405 2406 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2407 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2408 transport = list_entry(pos, struct sctp_transport, transports); 2409 if (transport->state == SCTP_UNKNOWN) { 2410 sctp_assoc_rm_peer(asoc, transport); 2411 } 2412 } 2413 2414 /* The fixed INIT headers are always in network byte 2415 * order. 2416 */ 2417 asoc->peer.i.init_tag = 2418 ntohl(peer_init->init_hdr.init_tag); 2419 asoc->peer.i.a_rwnd = 2420 ntohl(peer_init->init_hdr.a_rwnd); 2421 asoc->peer.i.num_outbound_streams = 2422 ntohs(peer_init->init_hdr.num_outbound_streams); 2423 asoc->peer.i.num_inbound_streams = 2424 ntohs(peer_init->init_hdr.num_inbound_streams); 2425 asoc->peer.i.initial_tsn = 2426 ntohl(peer_init->init_hdr.initial_tsn); 2427 2428 asoc->strreset_inseq = asoc->peer.i.initial_tsn; 2429 2430 /* Apply the upper bounds for output streams based on peer's 2431 * number of inbound streams. 2432 */ 2433 if (asoc->c.sinit_num_ostreams > 2434 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2435 asoc->c.sinit_num_ostreams = 2436 ntohs(peer_init->init_hdr.num_inbound_streams); 2437 } 2438 2439 if (asoc->c.sinit_max_instreams > 2440 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2441 asoc->c.sinit_max_instreams = 2442 ntohs(peer_init->init_hdr.num_outbound_streams); 2443 } 2444 2445 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2446 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2447 2448 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2449 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2450 2451 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2452 * high (for example, implementations MAY use the size of the receiver 2453 * advertised window). 2454 */ 2455 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2456 transports) { 2457 transport->ssthresh = asoc->peer.i.a_rwnd; 2458 } 2459 2460 /* Set up the TSN tracking pieces. */ 2461 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2462 asoc->peer.i.initial_tsn, gfp)) 2463 goto clean_up; 2464 2465 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2466 * 2467 * The stream sequence number in all the streams shall start 2468 * from 0 when the association is established. Also, when the 2469 * stream sequence number reaches the value 65535 the next 2470 * stream sequence number shall be set to 0. 2471 */ 2472 2473 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams, 2474 asoc->c.sinit_max_instreams, gfp)) 2475 goto clean_up; 2476 2477 /* Update frag_point when stream_interleave may get changed. */ 2478 sctp_assoc_update_frag_point(asoc); 2479 2480 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp)) 2481 goto clean_up; 2482 2483 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2484 * 2485 * When an endpoint has an ASCONF signaled change to be sent to the 2486 * remote endpoint it should do the following: 2487 * ... 2488 * A2) A serial number should be assigned to the Chunk. The serial 2489 * number should be a monotonically increasing number. All serial 2490 * numbers are defined to be initialized at the start of the 2491 * association to the same value as the Initial TSN. 2492 */ 2493 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2494 return 1; 2495 2496 clean_up: 2497 /* Release the transport structures. */ 2498 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2499 transport = list_entry(pos, struct sctp_transport, transports); 2500 if (transport->state != SCTP_ACTIVE) 2501 sctp_assoc_rm_peer(asoc, transport); 2502 } 2503 2504 nomem: 2505 return 0; 2506 } 2507 2508 2509 /* Update asoc with the option described in param. 2510 * 2511 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2512 * 2513 * asoc is the association to update. 2514 * param is the variable length parameter to use for update. 2515 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2516 * If the current packet is an INIT we want to minimize the amount of 2517 * work we do. In particular, we should not build transport 2518 * structures for the addresses. 2519 */ 2520 static int sctp_process_param(struct sctp_association *asoc, 2521 union sctp_params param, 2522 const union sctp_addr *peer_addr, 2523 gfp_t gfp) 2524 { 2525 struct sctp_endpoint *ep = asoc->ep; 2526 union sctp_addr_param *addr_param; 2527 struct net *net = asoc->base.net; 2528 struct sctp_transport *t; 2529 enum sctp_scope scope; 2530 union sctp_addr addr; 2531 struct sctp_af *af; 2532 int retval = 1, i; 2533 u32 stale; 2534 __u16 sat; 2535 2536 /* We maintain all INIT parameters in network byte order all the 2537 * time. This allows us to not worry about whether the parameters 2538 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2539 */ 2540 switch (param.p->type) { 2541 case SCTP_PARAM_IPV6_ADDRESS: 2542 if (PF_INET6 != asoc->base.sk->sk_family) 2543 break; 2544 goto do_addr_param; 2545 2546 case SCTP_PARAM_IPV4_ADDRESS: 2547 /* v4 addresses are not allowed on v6-only socket */ 2548 if (ipv6_only_sock(asoc->base.sk)) 2549 break; 2550 do_addr_param: 2551 af = sctp_get_af_specific(param_type2af(param.p->type)); 2552 if (!af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0)) 2553 break; 2554 scope = sctp_scope(peer_addr); 2555 if (sctp_in_scope(net, &addr, scope)) 2556 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2557 return 0; 2558 break; 2559 2560 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2561 if (!net->sctp.cookie_preserve_enable) 2562 break; 2563 2564 stale = ntohl(param.life->lifespan_increment); 2565 2566 /* Suggested Cookie Life span increment's unit is msec, 2567 * (1/1000sec). 2568 */ 2569 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale); 2570 break; 2571 2572 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2573 /* Turn off the default values first so we'll know which 2574 * ones are really set by the peer. 2575 */ 2576 asoc->peer.ipv4_address = 0; 2577 asoc->peer.ipv6_address = 0; 2578 2579 /* Assume that peer supports the address family 2580 * by which it sends a packet. 2581 */ 2582 if (peer_addr->sa.sa_family == AF_INET6) 2583 asoc->peer.ipv6_address = 1; 2584 else if (peer_addr->sa.sa_family == AF_INET) 2585 asoc->peer.ipv4_address = 1; 2586 2587 /* Cycle through address types; avoid divide by 0. */ 2588 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2589 if (sat) 2590 sat /= sizeof(__u16); 2591 2592 for (i = 0; i < sat; ++i) { 2593 switch (param.sat->types[i]) { 2594 case SCTP_PARAM_IPV4_ADDRESS: 2595 asoc->peer.ipv4_address = 1; 2596 break; 2597 2598 case SCTP_PARAM_IPV6_ADDRESS: 2599 if (PF_INET6 == asoc->base.sk->sk_family) 2600 asoc->peer.ipv6_address = 1; 2601 break; 2602 2603 default: /* Just ignore anything else. */ 2604 break; 2605 } 2606 } 2607 break; 2608 2609 case SCTP_PARAM_STATE_COOKIE: 2610 asoc->peer.cookie_len = 2611 ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2612 kfree(asoc->peer.cookie); 2613 asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp); 2614 if (!asoc->peer.cookie) 2615 retval = 0; 2616 break; 2617 2618 case SCTP_PARAM_HEARTBEAT_INFO: 2619 /* Would be odd to receive, but it causes no problems. */ 2620 break; 2621 2622 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2623 /* Rejected during verify stage. */ 2624 break; 2625 2626 case SCTP_PARAM_ECN_CAPABLE: 2627 if (asoc->ep->ecn_enable) { 2628 asoc->peer.ecn_capable = 1; 2629 break; 2630 } 2631 /* Fall Through */ 2632 goto fall_through; 2633 2634 2635 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2636 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2637 break; 2638 2639 case SCTP_PARAM_SET_PRIMARY: 2640 if (!ep->asconf_enable) 2641 goto fall_through; 2642 2643 addr_param = param.v + sizeof(struct sctp_addip_param); 2644 if (ntohs(addr_param->p.length) > 2645 ntohs(param.p->length) - sizeof(struct sctp_addip_param)) 2646 break; 2647 2648 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 2649 if (!af) 2650 break; 2651 2652 if (!af->from_addr_param(&addr, addr_param, 2653 htons(asoc->peer.port), 0)) 2654 break; 2655 2656 if (!af->addr_valid(&addr, NULL, NULL)) 2657 break; 2658 2659 t = sctp_assoc_lookup_paddr(asoc, &addr); 2660 if (!t) 2661 break; 2662 2663 sctp_assoc_set_primary(asoc, t); 2664 break; 2665 2666 case SCTP_PARAM_SUPPORTED_EXT: 2667 sctp_process_ext_param(asoc, param); 2668 break; 2669 2670 case SCTP_PARAM_FWD_TSN_SUPPORT: 2671 if (asoc->ep->prsctp_enable) { 2672 asoc->peer.prsctp_capable = 1; 2673 break; 2674 } 2675 /* Fall Through */ 2676 goto fall_through; 2677 2678 case SCTP_PARAM_RANDOM: 2679 if (!ep->auth_enable) 2680 goto fall_through; 2681 2682 /* Save peer's random parameter */ 2683 kfree(asoc->peer.peer_random); 2684 asoc->peer.peer_random = kmemdup(param.p, 2685 ntohs(param.p->length), gfp); 2686 if (!asoc->peer.peer_random) { 2687 retval = 0; 2688 break; 2689 } 2690 break; 2691 2692 case SCTP_PARAM_HMAC_ALGO: 2693 if (!ep->auth_enable) 2694 goto fall_through; 2695 2696 /* Save peer's HMAC list */ 2697 kfree(asoc->peer.peer_hmacs); 2698 asoc->peer.peer_hmacs = kmemdup(param.p, 2699 ntohs(param.p->length), gfp); 2700 if (!asoc->peer.peer_hmacs) { 2701 retval = 0; 2702 break; 2703 } 2704 2705 /* Set the default HMAC the peer requested*/ 2706 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2707 break; 2708 2709 case SCTP_PARAM_CHUNKS: 2710 if (!ep->auth_enable) 2711 goto fall_through; 2712 2713 kfree(asoc->peer.peer_chunks); 2714 asoc->peer.peer_chunks = kmemdup(param.p, 2715 ntohs(param.p->length), gfp); 2716 if (!asoc->peer.peer_chunks) 2717 retval = 0; 2718 break; 2719 fall_through: 2720 default: 2721 /* Any unrecognized parameters should have been caught 2722 * and handled by sctp_verify_param() which should be 2723 * called prior to this routine. Simply log the error 2724 * here. 2725 */ 2726 pr_debug("%s: ignoring param:%d for association:%p.\n", 2727 __func__, ntohs(param.p->type), asoc); 2728 break; 2729 } 2730 2731 return retval; 2732 } 2733 2734 /* Select a new verification tag. */ 2735 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2736 { 2737 /* I believe that this random number generator complies with RFC1750. 2738 * A tag of 0 is reserved for special cases (e.g. INIT). 2739 */ 2740 __u32 x; 2741 2742 do { 2743 x = get_random_u32(); 2744 } while (x == 0); 2745 2746 return x; 2747 } 2748 2749 /* Select an initial TSN to send during startup. */ 2750 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2751 { 2752 __u32 retval; 2753 2754 retval = get_random_u32(); 2755 return retval; 2756 } 2757 2758 /* 2759 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2760 * 0 1 2 3 2761 * 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 2762 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2763 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2764 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2765 * | Serial Number | 2766 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2767 * | Address Parameter | 2768 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2769 * | ASCONF Parameter #1 | 2770 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2771 * \ \ 2772 * / .... / 2773 * \ \ 2774 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2775 * | ASCONF Parameter #N | 2776 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2777 * 2778 * Address Parameter and other parameter will not be wrapped in this function 2779 */ 2780 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2781 union sctp_addr *addr, 2782 int vparam_len) 2783 { 2784 struct sctp_addiphdr asconf; 2785 struct sctp_chunk *retval; 2786 int length = sizeof(asconf) + vparam_len; 2787 union sctp_addr_param addrparam; 2788 int addrlen; 2789 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2790 2791 addrlen = af->to_addr_param(addr, &addrparam); 2792 if (!addrlen) 2793 return NULL; 2794 length += addrlen; 2795 2796 /* Create the chunk. */ 2797 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length, 2798 GFP_ATOMIC); 2799 if (!retval) 2800 return NULL; 2801 2802 asconf.serial = htonl(asoc->addip_serial++); 2803 2804 retval->subh.addip_hdr = 2805 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2806 retval->param_hdr.v = 2807 sctp_addto_chunk(retval, addrlen, &addrparam); 2808 2809 return retval; 2810 } 2811 2812 /* ADDIP 2813 * 3.2.1 Add IP Address 2814 * 0 1 2 3 2815 * 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 2816 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2817 * | Type = 0xC001 | Length = Variable | 2818 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2819 * | ASCONF-Request Correlation ID | 2820 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2821 * | Address Parameter | 2822 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2823 * 2824 * 3.2.2 Delete IP Address 2825 * 0 1 2 3 2826 * 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 2827 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2828 * | Type = 0xC002 | Length = Variable | 2829 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2830 * | ASCONF-Request Correlation ID | 2831 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2832 * | Address Parameter | 2833 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2834 * 2835 */ 2836 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2837 union sctp_addr *laddr, 2838 struct sockaddr *addrs, 2839 int addrcnt, __be16 flags) 2840 { 2841 union sctp_addr_param addr_param; 2842 struct sctp_addip_param param; 2843 int paramlen = sizeof(param); 2844 struct sctp_chunk *retval; 2845 int addr_param_len = 0; 2846 union sctp_addr *addr; 2847 int totallen = 0, i; 2848 int del_pickup = 0; 2849 struct sctp_af *af; 2850 void *addr_buf; 2851 2852 /* Get total length of all the address parameters. */ 2853 addr_buf = addrs; 2854 for (i = 0; i < addrcnt; i++) { 2855 addr = addr_buf; 2856 af = sctp_get_af_specific(addr->v4.sin_family); 2857 addr_param_len = af->to_addr_param(addr, &addr_param); 2858 2859 totallen += paramlen; 2860 totallen += addr_param_len; 2861 2862 addr_buf += af->sockaddr_len; 2863 if (asoc->asconf_addr_del_pending && !del_pickup) { 2864 /* reuse the parameter length from the same scope one */ 2865 totallen += paramlen; 2866 totallen += addr_param_len; 2867 del_pickup = 1; 2868 2869 pr_debug("%s: picked same-scope del_pending addr, " 2870 "totallen for all addresses is %d\n", 2871 __func__, totallen); 2872 } 2873 } 2874 2875 /* Create an asconf chunk with the required length. */ 2876 retval = sctp_make_asconf(asoc, laddr, totallen); 2877 if (!retval) 2878 return NULL; 2879 2880 /* Add the address parameters to the asconf chunk. */ 2881 addr_buf = addrs; 2882 for (i = 0; i < addrcnt; i++) { 2883 addr = addr_buf; 2884 af = sctp_get_af_specific(addr->v4.sin_family); 2885 addr_param_len = af->to_addr_param(addr, &addr_param); 2886 param.param_hdr.type = flags; 2887 param.param_hdr.length = htons(paramlen + addr_param_len); 2888 param.crr_id = htonl(i); 2889 2890 sctp_addto_chunk(retval, paramlen, ¶m); 2891 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2892 2893 addr_buf += af->sockaddr_len; 2894 } 2895 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2896 addr = asoc->asconf_addr_del_pending; 2897 af = sctp_get_af_specific(addr->v4.sin_family); 2898 addr_param_len = af->to_addr_param(addr, &addr_param); 2899 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2900 param.param_hdr.length = htons(paramlen + addr_param_len); 2901 param.crr_id = htonl(i); 2902 2903 sctp_addto_chunk(retval, paramlen, ¶m); 2904 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2905 } 2906 return retval; 2907 } 2908 2909 /* ADDIP 2910 * 3.2.4 Set Primary IP Address 2911 * 0 1 2 3 2912 * 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 2913 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2914 * | Type =0xC004 | Length = Variable | 2915 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2916 * | ASCONF-Request Correlation ID | 2917 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2918 * | Address Parameter | 2919 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2920 * 2921 * Create an ASCONF chunk with Set Primary IP address parameter. 2922 */ 2923 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2924 union sctp_addr *addr) 2925 { 2926 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2927 union sctp_addr_param addrparam; 2928 struct sctp_addip_param param; 2929 struct sctp_chunk *retval; 2930 int len = sizeof(param); 2931 int addrlen; 2932 2933 addrlen = af->to_addr_param(addr, &addrparam); 2934 if (!addrlen) 2935 return NULL; 2936 len += addrlen; 2937 2938 /* Create the chunk and make asconf header. */ 2939 retval = sctp_make_asconf(asoc, addr, len); 2940 if (!retval) 2941 return NULL; 2942 2943 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2944 param.param_hdr.length = htons(len); 2945 param.crr_id = 0; 2946 2947 sctp_addto_chunk(retval, sizeof(param), ¶m); 2948 sctp_addto_chunk(retval, addrlen, &addrparam); 2949 2950 return retval; 2951 } 2952 2953 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2954 * 0 1 2 3 2955 * 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 2956 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2957 * | Type = 0x80 | Chunk Flags | Chunk Length | 2958 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2959 * | Serial Number | 2960 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2961 * | ASCONF Parameter Response#1 | 2962 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2963 * \ \ 2964 * / .... / 2965 * \ \ 2966 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2967 * | ASCONF Parameter Response#N | 2968 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2969 * 2970 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2971 */ 2972 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2973 __u32 serial, int vparam_len) 2974 { 2975 struct sctp_addiphdr asconf; 2976 struct sctp_chunk *retval; 2977 int length = sizeof(asconf) + vparam_len; 2978 2979 /* Create the chunk. */ 2980 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length, 2981 GFP_ATOMIC); 2982 if (!retval) 2983 return NULL; 2984 2985 asconf.serial = htonl(serial); 2986 2987 retval->subh.addip_hdr = 2988 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2989 2990 return retval; 2991 } 2992 2993 /* Add response parameters to an ASCONF_ACK chunk. */ 2994 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2995 __be16 err_code, 2996 struct sctp_addip_param *asconf_param) 2997 { 2998 struct sctp_addip_param ack_param; 2999 struct sctp_errhdr err_param; 3000 int asconf_param_len = 0; 3001 int err_param_len = 0; 3002 __be16 response_type; 3003 3004 if (SCTP_ERROR_NO_ERROR == err_code) { 3005 response_type = SCTP_PARAM_SUCCESS_REPORT; 3006 } else { 3007 response_type = SCTP_PARAM_ERR_CAUSE; 3008 err_param_len = sizeof(err_param); 3009 if (asconf_param) 3010 asconf_param_len = 3011 ntohs(asconf_param->param_hdr.length); 3012 } 3013 3014 /* Add Success Indication or Error Cause Indication parameter. */ 3015 ack_param.param_hdr.type = response_type; 3016 ack_param.param_hdr.length = htons(sizeof(ack_param) + 3017 err_param_len + 3018 asconf_param_len); 3019 ack_param.crr_id = crr_id; 3020 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 3021 3022 if (SCTP_ERROR_NO_ERROR == err_code) 3023 return; 3024 3025 /* Add Error Cause parameter. */ 3026 err_param.cause = err_code; 3027 err_param.length = htons(err_param_len + asconf_param_len); 3028 sctp_addto_chunk(chunk, err_param_len, &err_param); 3029 3030 /* Add the failed TLV copied from ASCONF chunk. */ 3031 if (asconf_param) 3032 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 3033 } 3034 3035 /* Process a asconf parameter. */ 3036 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 3037 struct sctp_chunk *asconf, 3038 struct sctp_addip_param *asconf_param) 3039 { 3040 union sctp_addr_param *addr_param; 3041 struct sctp_transport *peer; 3042 union sctp_addr addr; 3043 struct sctp_af *af; 3044 3045 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 3046 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 3047 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 3048 return SCTP_ERROR_UNKNOWN_PARAM; 3049 3050 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3051 if (ntohs(addr_param->p.length) > 3052 ntohs(asconf_param->param_hdr.length) - sizeof(*asconf_param)) 3053 return SCTP_ERROR_PROTO_VIOLATION; 3054 3055 switch (addr_param->p.type) { 3056 case SCTP_PARAM_IPV6_ADDRESS: 3057 if (!asoc->peer.ipv6_address) 3058 return SCTP_ERROR_DNS_FAILED; 3059 break; 3060 case SCTP_PARAM_IPV4_ADDRESS: 3061 if (!asoc->peer.ipv4_address) 3062 return SCTP_ERROR_DNS_FAILED; 3063 break; 3064 default: 3065 return SCTP_ERROR_DNS_FAILED; 3066 } 3067 3068 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3069 if (unlikely(!af)) 3070 return SCTP_ERROR_DNS_FAILED; 3071 3072 if (!af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0)) 3073 return SCTP_ERROR_DNS_FAILED; 3074 3075 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3076 * or multicast address. 3077 * (note: wildcard is permitted and requires special handling so 3078 * make sure we check for that) 3079 */ 3080 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3081 return SCTP_ERROR_DNS_FAILED; 3082 3083 switch (asconf_param->param_hdr.type) { 3084 case SCTP_PARAM_ADD_IP: 3085 /* Section 4.2.1: 3086 * If the address 0.0.0.0 or ::0 is provided, the source 3087 * address of the packet MUST be added. 3088 */ 3089 if (af->is_any(&addr)) 3090 memcpy(&addr, &asconf->source, sizeof(addr)); 3091 3092 if (security_sctp_bind_connect(asoc->ep->base.sk, 3093 SCTP_PARAM_ADD_IP, 3094 (struct sockaddr *)&addr, 3095 af->sockaddr_len)) 3096 return SCTP_ERROR_REQ_REFUSED; 3097 3098 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3099 * request and does not have the local resources to add this 3100 * new address to the association, it MUST return an Error 3101 * Cause TLV set to the new error code 'Operation Refused 3102 * Due to Resource Shortage'. 3103 */ 3104 3105 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3106 if (!peer) 3107 return SCTP_ERROR_RSRC_LOW; 3108 3109 /* Start the heartbeat timer. */ 3110 sctp_transport_reset_hb_timer(peer); 3111 asoc->new_transport = peer; 3112 break; 3113 case SCTP_PARAM_DEL_IP: 3114 /* ADDIP 4.3 D7) If a request is received to delete the 3115 * last remaining IP address of a peer endpoint, the receiver 3116 * MUST send an Error Cause TLV with the error cause set to the 3117 * new error code 'Request to Delete Last Remaining IP Address'. 3118 */ 3119 if (asoc->peer.transport_count == 1) 3120 return SCTP_ERROR_DEL_LAST_IP; 3121 3122 /* ADDIP 4.3 D8) If a request is received to delete an IP 3123 * address which is also the source address of the IP packet 3124 * which contained the ASCONF chunk, the receiver MUST reject 3125 * this request. To reject the request the receiver MUST send 3126 * an Error Cause TLV set to the new error code 'Request to 3127 * Delete Source IP Address' 3128 */ 3129 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3130 return SCTP_ERROR_DEL_SRC_IP; 3131 3132 /* Section 4.2.2 3133 * If the address 0.0.0.0 or ::0 is provided, all 3134 * addresses of the peer except the source address of the 3135 * packet MUST be deleted. 3136 */ 3137 if (af->is_any(&addr)) { 3138 sctp_assoc_set_primary(asoc, asconf->transport); 3139 sctp_assoc_del_nonprimary_peers(asoc, 3140 asconf->transport); 3141 return SCTP_ERROR_NO_ERROR; 3142 } 3143 3144 /* If the address is not part of the association, the 3145 * ASCONF-ACK with Error Cause Indication Parameter 3146 * which including cause of Unresolvable Address should 3147 * be sent. 3148 */ 3149 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3150 if (!peer) 3151 return SCTP_ERROR_DNS_FAILED; 3152 3153 sctp_assoc_rm_peer(asoc, peer); 3154 break; 3155 case SCTP_PARAM_SET_PRIMARY: 3156 /* ADDIP Section 4.2.4 3157 * If the address 0.0.0.0 or ::0 is provided, the receiver 3158 * MAY mark the source address of the packet as its 3159 * primary. 3160 */ 3161 if (af->is_any(&addr)) 3162 memcpy(&addr, sctp_source(asconf), sizeof(addr)); 3163 3164 if (security_sctp_bind_connect(asoc->ep->base.sk, 3165 SCTP_PARAM_SET_PRIMARY, 3166 (struct sockaddr *)&addr, 3167 af->sockaddr_len)) 3168 return SCTP_ERROR_REQ_REFUSED; 3169 3170 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3171 if (!peer) 3172 return SCTP_ERROR_DNS_FAILED; 3173 3174 sctp_assoc_set_primary(asoc, peer); 3175 break; 3176 } 3177 3178 return SCTP_ERROR_NO_ERROR; 3179 } 3180 3181 /* Verify the ASCONF packet before we process it. */ 3182 bool sctp_verify_asconf(const struct sctp_association *asoc, 3183 struct sctp_chunk *chunk, bool addr_param_needed, 3184 struct sctp_paramhdr **errp) 3185 { 3186 struct sctp_addip_chunk *addip; 3187 bool addr_param_seen = false; 3188 union sctp_params param; 3189 3190 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr; 3191 sctp_walk_params(param, addip) { 3192 size_t length = ntohs(param.p->length); 3193 3194 *errp = param.p; 3195 switch (param.p->type) { 3196 case SCTP_PARAM_ERR_CAUSE: 3197 break; 3198 case SCTP_PARAM_IPV4_ADDRESS: 3199 if (length != sizeof(struct sctp_ipv4addr_param)) 3200 return false; 3201 /* ensure there is only one addr param and it's in the 3202 * beginning of addip_hdr params, or we reject it. 3203 */ 3204 if (param.v != (addip + 1)) 3205 return false; 3206 addr_param_seen = true; 3207 break; 3208 case SCTP_PARAM_IPV6_ADDRESS: 3209 if (length != sizeof(struct sctp_ipv6addr_param)) 3210 return false; 3211 if (param.v != (addip + 1)) 3212 return false; 3213 addr_param_seen = true; 3214 break; 3215 case SCTP_PARAM_ADD_IP: 3216 case SCTP_PARAM_DEL_IP: 3217 case SCTP_PARAM_SET_PRIMARY: 3218 /* In ASCONF chunks, these need to be first. */ 3219 if (addr_param_needed && !addr_param_seen) 3220 return false; 3221 length = ntohs(param.addip->param_hdr.length); 3222 if (length < sizeof(struct sctp_addip_param) + 3223 sizeof(**errp)) 3224 return false; 3225 break; 3226 case SCTP_PARAM_SUCCESS_REPORT: 3227 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3228 if (length != sizeof(struct sctp_addip_param)) 3229 return false; 3230 break; 3231 default: 3232 /* This is unknown to us, reject! */ 3233 return false; 3234 } 3235 } 3236 3237 /* Remaining sanity checks. */ 3238 if (addr_param_needed && !addr_param_seen) 3239 return false; 3240 if (!addr_param_needed && addr_param_seen) 3241 return false; 3242 if (param.v != chunk->chunk_end) 3243 return false; 3244 3245 return true; 3246 } 3247 3248 /* Process an incoming ASCONF chunk with the next expected serial no. and 3249 * return an ASCONF_ACK chunk to be sent in response. 3250 */ 3251 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3252 struct sctp_chunk *asconf) 3253 { 3254 union sctp_addr_param *addr_param; 3255 struct sctp_addip_chunk *addip; 3256 struct sctp_chunk *asconf_ack; 3257 bool all_param_pass = true; 3258 struct sctp_addiphdr *hdr; 3259 int length = 0, chunk_len; 3260 union sctp_params param; 3261 __be16 err_code; 3262 __u32 serial; 3263 3264 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr; 3265 chunk_len = ntohs(asconf->chunk_hdr->length) - 3266 sizeof(struct sctp_chunkhdr); 3267 hdr = (struct sctp_addiphdr *)asconf->skb->data; 3268 serial = ntohl(hdr->serial); 3269 3270 /* Skip the addiphdr and store a pointer to address parameter. */ 3271 length = sizeof(*hdr); 3272 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3273 chunk_len -= length; 3274 3275 /* Skip the address parameter and store a pointer to the first 3276 * asconf parameter. 3277 */ 3278 length = ntohs(addr_param->p.length); 3279 chunk_len -= length; 3280 3281 /* create an ASCONF_ACK chunk. 3282 * Based on the definitions of parameters, we know that the size of 3283 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3284 * parameters. 3285 */ 3286 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3287 if (!asconf_ack) 3288 goto done; 3289 3290 /* Process the TLVs contained within the ASCONF chunk. */ 3291 sctp_walk_params(param, addip) { 3292 /* Skip preceding address parameters. */ 3293 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 3294 param.p->type == SCTP_PARAM_IPV6_ADDRESS) 3295 continue; 3296 3297 err_code = sctp_process_asconf_param(asoc, asconf, 3298 param.addip); 3299 /* ADDIP 4.1 A7) 3300 * If an error response is received for a TLV parameter, 3301 * all TLVs with no response before the failed TLV are 3302 * considered successful if not reported. All TLVs after 3303 * the failed response are considered unsuccessful unless 3304 * a specific success indication is present for the parameter. 3305 */ 3306 if (err_code != SCTP_ERROR_NO_ERROR) 3307 all_param_pass = false; 3308 if (!all_param_pass) 3309 sctp_add_asconf_response(asconf_ack, param.addip->crr_id, 3310 err_code, param.addip); 3311 3312 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3313 * an IP address sends an 'Out of Resource' in its response, it 3314 * MUST also fail any subsequent add or delete requests bundled 3315 * in the ASCONF. 3316 */ 3317 if (err_code == SCTP_ERROR_RSRC_LOW) 3318 goto done; 3319 } 3320 done: 3321 asoc->peer.addip_serial++; 3322 3323 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3324 * after freeing the reference to old asconf ack if any. 3325 */ 3326 if (asconf_ack) { 3327 sctp_chunk_hold(asconf_ack); 3328 list_add_tail(&asconf_ack->transmitted_list, 3329 &asoc->asconf_ack_list); 3330 } 3331 3332 return asconf_ack; 3333 } 3334 3335 /* Process a asconf parameter that is successfully acked. */ 3336 static void sctp_asconf_param_success(struct sctp_association *asoc, 3337 struct sctp_addip_param *asconf_param) 3338 { 3339 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3340 union sctp_addr_param *addr_param; 3341 struct sctp_sockaddr_entry *saddr; 3342 struct sctp_transport *transport; 3343 union sctp_addr addr; 3344 struct sctp_af *af; 3345 3346 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3347 3348 /* We have checked the packet before, so we do not check again. */ 3349 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3350 if (!af->from_addr_param(&addr, addr_param, htons(bp->port), 0)) 3351 return; 3352 3353 switch (asconf_param->param_hdr.type) { 3354 case SCTP_PARAM_ADD_IP: 3355 /* This is always done in BH context with a socket lock 3356 * held, so the list can not change. 3357 */ 3358 local_bh_disable(); 3359 list_for_each_entry(saddr, &bp->address_list, list) { 3360 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3361 saddr->state = SCTP_ADDR_SRC; 3362 } 3363 local_bh_enable(); 3364 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3365 transports) { 3366 sctp_transport_dst_release(transport); 3367 } 3368 break; 3369 case SCTP_PARAM_DEL_IP: 3370 local_bh_disable(); 3371 sctp_del_bind_addr(bp, &addr); 3372 if (asoc->asconf_addr_del_pending != NULL && 3373 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3374 kfree(asoc->asconf_addr_del_pending); 3375 asoc->asconf_addr_del_pending = NULL; 3376 } 3377 local_bh_enable(); 3378 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3379 transports) { 3380 sctp_transport_dst_release(transport); 3381 } 3382 break; 3383 default: 3384 break; 3385 } 3386 } 3387 3388 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3389 * for the given asconf parameter. If there is no response for this parameter, 3390 * return the error code based on the third argument 'no_err'. 3391 * ADDIP 4.1 3392 * A7) If an error response is received for a TLV parameter, all TLVs with no 3393 * response before the failed TLV are considered successful if not reported. 3394 * All TLVs after the failed response are considered unsuccessful unless a 3395 * specific success indication is present for the parameter. 3396 */ 3397 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3398 struct sctp_addip_param *asconf_param, 3399 int no_err) 3400 { 3401 struct sctp_addip_param *asconf_ack_param; 3402 struct sctp_errhdr *err_param; 3403 int asconf_ack_len; 3404 __be16 err_code; 3405 int length; 3406 3407 if (no_err) 3408 err_code = SCTP_ERROR_NO_ERROR; 3409 else 3410 err_code = SCTP_ERROR_REQ_REFUSED; 3411 3412 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3413 sizeof(struct sctp_chunkhdr); 3414 3415 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3416 * the first asconf_ack parameter. 3417 */ 3418 length = sizeof(struct sctp_addiphdr); 3419 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data + 3420 length); 3421 asconf_ack_len -= length; 3422 3423 while (asconf_ack_len > 0) { 3424 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3425 switch (asconf_ack_param->param_hdr.type) { 3426 case SCTP_PARAM_SUCCESS_REPORT: 3427 return SCTP_ERROR_NO_ERROR; 3428 case SCTP_PARAM_ERR_CAUSE: 3429 length = sizeof(*asconf_ack_param); 3430 err_param = (void *)asconf_ack_param + length; 3431 asconf_ack_len -= length; 3432 if (asconf_ack_len > 0) 3433 return err_param->cause; 3434 else 3435 return SCTP_ERROR_INV_PARAM; 3436 break; 3437 default: 3438 return SCTP_ERROR_INV_PARAM; 3439 } 3440 } 3441 3442 length = ntohs(asconf_ack_param->param_hdr.length); 3443 asconf_ack_param = (void *)asconf_ack_param + length; 3444 asconf_ack_len -= length; 3445 } 3446 3447 return err_code; 3448 } 3449 3450 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3451 int sctp_process_asconf_ack(struct sctp_association *asoc, 3452 struct sctp_chunk *asconf_ack) 3453 { 3454 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3455 struct sctp_addip_param *asconf_param; 3456 __be16 err_code = SCTP_ERROR_NO_ERROR; 3457 union sctp_addr_param *addr_param; 3458 int asconf_len = asconf->skb->len; 3459 int all_param_pass = 0; 3460 int length = 0; 3461 int no_err = 1; 3462 int retval = 0; 3463 3464 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3465 * a pointer to address parameter. 3466 */ 3467 length = sizeof(struct sctp_addip_chunk); 3468 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3469 asconf_len -= length; 3470 3471 /* Skip the address parameter in the last asconf sent and store a 3472 * pointer to the first asconf parameter. 3473 */ 3474 length = ntohs(addr_param->p.length); 3475 asconf_param = (void *)addr_param + length; 3476 asconf_len -= length; 3477 3478 /* ADDIP 4.1 3479 * A8) If there is no response(s) to specific TLV parameter(s), and no 3480 * failures are indicated, then all request(s) are considered 3481 * successful. 3482 */ 3483 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr)) 3484 all_param_pass = 1; 3485 3486 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3487 while (asconf_len > 0) { 3488 if (all_param_pass) 3489 err_code = SCTP_ERROR_NO_ERROR; 3490 else { 3491 err_code = sctp_get_asconf_response(asconf_ack, 3492 asconf_param, 3493 no_err); 3494 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3495 no_err = 0; 3496 } 3497 3498 switch (err_code) { 3499 case SCTP_ERROR_NO_ERROR: 3500 sctp_asconf_param_success(asoc, asconf_param); 3501 break; 3502 3503 case SCTP_ERROR_RSRC_LOW: 3504 retval = 1; 3505 break; 3506 3507 case SCTP_ERROR_UNKNOWN_PARAM: 3508 /* Disable sending this type of asconf parameter in 3509 * future. 3510 */ 3511 asoc->peer.addip_disabled_mask |= 3512 asconf_param->param_hdr.type; 3513 break; 3514 3515 case SCTP_ERROR_REQ_REFUSED: 3516 case SCTP_ERROR_DEL_LAST_IP: 3517 case SCTP_ERROR_DEL_SRC_IP: 3518 default: 3519 break; 3520 } 3521 3522 /* Skip the processed asconf parameter and move to the next 3523 * one. 3524 */ 3525 length = ntohs(asconf_param->param_hdr.length); 3526 asconf_param = (void *)asconf_param + length; 3527 asconf_len -= length; 3528 } 3529 3530 if (no_err && asoc->src_out_of_asoc_ok) { 3531 asoc->src_out_of_asoc_ok = 0; 3532 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3533 } 3534 3535 /* Free the cached last sent asconf chunk. */ 3536 list_del_init(&asconf->transmitted_list); 3537 sctp_chunk_free(asconf); 3538 asoc->addip_last_asconf = NULL; 3539 3540 return retval; 3541 } 3542 3543 /* Make a FWD TSN chunk. */ 3544 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3545 __u32 new_cum_tsn, size_t nstreams, 3546 struct sctp_fwdtsn_skip *skiplist) 3547 { 3548 struct sctp_chunk *retval = NULL; 3549 struct sctp_fwdtsn_hdr ftsn_hdr; 3550 struct sctp_fwdtsn_skip skip; 3551 size_t hint; 3552 int i; 3553 3554 hint = (nstreams + 1) * sizeof(__u32); 3555 3556 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC); 3557 3558 if (!retval) 3559 return NULL; 3560 3561 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3562 retval->subh.fwdtsn_hdr = 3563 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3564 3565 for (i = 0; i < nstreams; i++) { 3566 skip.stream = skiplist[i].stream; 3567 skip.ssn = skiplist[i].ssn; 3568 sctp_addto_chunk(retval, sizeof(skip), &skip); 3569 } 3570 3571 return retval; 3572 } 3573 3574 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc, 3575 __u32 new_cum_tsn, size_t nstreams, 3576 struct sctp_ifwdtsn_skip *skiplist) 3577 { 3578 struct sctp_chunk *retval = NULL; 3579 struct sctp_ifwdtsn_hdr ftsn_hdr; 3580 size_t hint; 3581 3582 hint = (nstreams + 1) * sizeof(__u32); 3583 3584 retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint, 3585 GFP_ATOMIC); 3586 if (!retval) 3587 return NULL; 3588 3589 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3590 retval->subh.ifwdtsn_hdr = 3591 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3592 3593 sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist); 3594 3595 return retval; 3596 } 3597 3598 /* RE-CONFIG 3.1 (RE-CONFIG chunk) 3599 * 0 1 2 3 3600 * 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 3601 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3602 * | Type = 130 | Chunk Flags | Chunk Length | 3603 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3604 * \ \ 3605 * / Re-configuration Parameter / 3606 * \ \ 3607 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3608 * \ \ 3609 * / Re-configuration Parameter (optional) / 3610 * \ \ 3611 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3612 */ 3613 static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc, 3614 int length) 3615 { 3616 struct sctp_reconf_chunk *reconf; 3617 struct sctp_chunk *retval; 3618 3619 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length, 3620 GFP_ATOMIC); 3621 if (!retval) 3622 return NULL; 3623 3624 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr; 3625 retval->param_hdr.v = (u8 *)(reconf + 1); 3626 3627 return retval; 3628 } 3629 3630 /* RE-CONFIG 4.1 (STREAM OUT RESET) 3631 * 0 1 2 3 3632 * 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 3633 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3634 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N | 3635 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3636 * | Re-configuration Request Sequence Number | 3637 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3638 * | Re-configuration Response Sequence Number | 3639 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3640 * | Sender's Last Assigned TSN | 3641 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3642 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3643 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3644 * / ...... / 3645 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3646 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3647 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3648 * 3649 * RE-CONFIG 4.2 (STREAM IN RESET) 3650 * 0 1 2 3 3651 * 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 3652 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3653 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N | 3654 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3655 * | Re-configuration Request Sequence Number | 3656 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3657 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3658 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3659 * / ...... / 3660 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3661 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3662 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3663 */ 3664 struct sctp_chunk *sctp_make_strreset_req( 3665 const struct sctp_association *asoc, 3666 __u16 stream_num, __be16 *stream_list, 3667 bool out, bool in) 3668 { 3669 __u16 stream_len = stream_num * sizeof(__u16); 3670 struct sctp_strreset_outreq outreq; 3671 struct sctp_strreset_inreq inreq; 3672 struct sctp_chunk *retval; 3673 __u16 outlen, inlen; 3674 3675 outlen = (sizeof(outreq) + stream_len) * out; 3676 inlen = (sizeof(inreq) + stream_len) * in; 3677 3678 retval = sctp_make_reconf(asoc, SCTP_PAD4(outlen) + SCTP_PAD4(inlen)); 3679 if (!retval) 3680 return NULL; 3681 3682 if (outlen) { 3683 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST; 3684 outreq.param_hdr.length = htons(outlen); 3685 outreq.request_seq = htonl(asoc->strreset_outseq); 3686 outreq.response_seq = htonl(asoc->strreset_inseq - 1); 3687 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1); 3688 3689 sctp_addto_chunk(retval, sizeof(outreq), &outreq); 3690 3691 if (stream_len) 3692 sctp_addto_chunk(retval, stream_len, stream_list); 3693 } 3694 3695 if (inlen) { 3696 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST; 3697 inreq.param_hdr.length = htons(inlen); 3698 inreq.request_seq = htonl(asoc->strreset_outseq + out); 3699 3700 sctp_addto_chunk(retval, sizeof(inreq), &inreq); 3701 3702 if (stream_len) 3703 sctp_addto_chunk(retval, stream_len, stream_list); 3704 } 3705 3706 return retval; 3707 } 3708 3709 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL) 3710 * 0 1 2 3 3711 * 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 3712 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3713 * | Parameter Type = 15 | Parameter Length = 8 | 3714 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3715 * | Re-configuration Request Sequence Number | 3716 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3717 */ 3718 struct sctp_chunk *sctp_make_strreset_tsnreq( 3719 const struct sctp_association *asoc) 3720 { 3721 struct sctp_strreset_tsnreq tsnreq; 3722 __u16 length = sizeof(tsnreq); 3723 struct sctp_chunk *retval; 3724 3725 retval = sctp_make_reconf(asoc, length); 3726 if (!retval) 3727 return NULL; 3728 3729 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST; 3730 tsnreq.param_hdr.length = htons(length); 3731 tsnreq.request_seq = htonl(asoc->strreset_outseq); 3732 3733 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq); 3734 3735 return retval; 3736 } 3737 3738 /* RE-CONFIG 4.5/4.6 (ADD STREAM) 3739 * 0 1 2 3 3740 * 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 3741 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3742 * | Parameter Type = 17 | Parameter Length = 12 | 3743 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3744 * | Re-configuration Request Sequence Number | 3745 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3746 * | Number of new streams | Reserved | 3747 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3748 */ 3749 struct sctp_chunk *sctp_make_strreset_addstrm( 3750 const struct sctp_association *asoc, 3751 __u16 out, __u16 in) 3752 { 3753 struct sctp_strreset_addstrm addstrm; 3754 __u16 size = sizeof(addstrm); 3755 struct sctp_chunk *retval; 3756 3757 retval = sctp_make_reconf(asoc, (!!out + !!in) * size); 3758 if (!retval) 3759 return NULL; 3760 3761 if (out) { 3762 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS; 3763 addstrm.param_hdr.length = htons(size); 3764 addstrm.number_of_streams = htons(out); 3765 addstrm.request_seq = htonl(asoc->strreset_outseq); 3766 addstrm.reserved = 0; 3767 3768 sctp_addto_chunk(retval, size, &addstrm); 3769 } 3770 3771 if (in) { 3772 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS; 3773 addstrm.param_hdr.length = htons(size); 3774 addstrm.number_of_streams = htons(in); 3775 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out); 3776 addstrm.reserved = 0; 3777 3778 sctp_addto_chunk(retval, size, &addstrm); 3779 } 3780 3781 return retval; 3782 } 3783 3784 /* RE-CONFIG 4.4 (RESP) 3785 * 0 1 2 3 3786 * 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 3787 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3788 * | Parameter Type = 16 | Parameter Length | 3789 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3790 * | Re-configuration Response Sequence Number | 3791 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3792 * | Result | 3793 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3794 */ 3795 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc, 3796 __u32 result, __u32 sn) 3797 { 3798 struct sctp_strreset_resp resp; 3799 __u16 length = sizeof(resp); 3800 struct sctp_chunk *retval; 3801 3802 retval = sctp_make_reconf(asoc, length); 3803 if (!retval) 3804 return NULL; 3805 3806 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3807 resp.param_hdr.length = htons(length); 3808 resp.response_seq = htonl(sn); 3809 resp.result = htonl(result); 3810 3811 sctp_addto_chunk(retval, sizeof(resp), &resp); 3812 3813 return retval; 3814 } 3815 3816 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP) 3817 * 0 1 2 3 3818 * 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 3819 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3820 * | Parameter Type = 16 | Parameter Length | 3821 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3822 * | Re-configuration Response Sequence Number | 3823 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3824 * | Result | 3825 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3826 * | Sender's Next TSN (optional) | 3827 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3828 * | Receiver's Next TSN (optional) | 3829 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3830 */ 3831 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc, 3832 __u32 result, __u32 sn, 3833 __u32 sender_tsn, 3834 __u32 receiver_tsn) 3835 { 3836 struct sctp_strreset_resptsn tsnresp; 3837 __u16 length = sizeof(tsnresp); 3838 struct sctp_chunk *retval; 3839 3840 retval = sctp_make_reconf(asoc, length); 3841 if (!retval) 3842 return NULL; 3843 3844 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3845 tsnresp.param_hdr.length = htons(length); 3846 3847 tsnresp.response_seq = htonl(sn); 3848 tsnresp.result = htonl(result); 3849 tsnresp.senders_next_tsn = htonl(sender_tsn); 3850 tsnresp.receivers_next_tsn = htonl(receiver_tsn); 3851 3852 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp); 3853 3854 return retval; 3855 } 3856 3857 bool sctp_verify_reconf(const struct sctp_association *asoc, 3858 struct sctp_chunk *chunk, 3859 struct sctp_paramhdr **errp) 3860 { 3861 struct sctp_reconf_chunk *hdr; 3862 union sctp_params param; 3863 __be16 last = 0; 3864 __u16 cnt = 0; 3865 3866 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; 3867 sctp_walk_params(param, hdr) { 3868 __u16 length = ntohs(param.p->length); 3869 3870 *errp = param.p; 3871 if (cnt++ > 2) 3872 return false; 3873 switch (param.p->type) { 3874 case SCTP_PARAM_RESET_OUT_REQUEST: 3875 if (length < sizeof(struct sctp_strreset_outreq) || 3876 (last && last != SCTP_PARAM_RESET_RESPONSE && 3877 last != SCTP_PARAM_RESET_IN_REQUEST)) 3878 return false; 3879 break; 3880 case SCTP_PARAM_RESET_IN_REQUEST: 3881 if (length < sizeof(struct sctp_strreset_inreq) || 3882 (last && last != SCTP_PARAM_RESET_OUT_REQUEST)) 3883 return false; 3884 break; 3885 case SCTP_PARAM_RESET_RESPONSE: 3886 if ((length != sizeof(struct sctp_strreset_resp) && 3887 length != sizeof(struct sctp_strreset_resptsn)) || 3888 (last && last != SCTP_PARAM_RESET_RESPONSE && 3889 last != SCTP_PARAM_RESET_OUT_REQUEST)) 3890 return false; 3891 break; 3892 case SCTP_PARAM_RESET_TSN_REQUEST: 3893 if (length != 3894 sizeof(struct sctp_strreset_tsnreq) || last) 3895 return false; 3896 break; 3897 case SCTP_PARAM_RESET_ADD_IN_STREAMS: 3898 if (length != sizeof(struct sctp_strreset_addstrm) || 3899 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS)) 3900 return false; 3901 break; 3902 case SCTP_PARAM_RESET_ADD_OUT_STREAMS: 3903 if (length != sizeof(struct sctp_strreset_addstrm) || 3904 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS)) 3905 return false; 3906 break; 3907 default: 3908 return false; 3909 } 3910 3911 last = param.p->type; 3912 } 3913 3914 return true; 3915 } 3916