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 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 if (!chunk->shkey) 111 chunk->shkey = asoc->shkey; 112 sctp_auth_shkey_hold(chunk->shkey); 113 } 114 skb->sk = asoc ? asoc->base.sk : NULL; 115 skb_shinfo(skb)->destructor_arg = chunk; 116 skb->destructor = sctp_control_release_owner; 117 } 118 119 /* RFC 2960 3.3.2 Initiation (INIT) (1) 120 * 121 * Note 2: The ECN capable field is reserved for future use of 122 * Explicit Congestion Notification. 123 */ 124 static const struct sctp_paramhdr ecap_param = { 125 SCTP_PARAM_ECN_CAPABLE, 126 cpu_to_be16(sizeof(struct sctp_paramhdr)), 127 }; 128 static const struct sctp_paramhdr prsctp_param = { 129 SCTP_PARAM_FWD_TSN_SUPPORT, 130 cpu_to_be16(sizeof(struct sctp_paramhdr)), 131 }; 132 133 /* A helper to initialize an op error inside a provided chunk, as most 134 * cause codes will be embedded inside an abort chunk. 135 */ 136 int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, 137 size_t paylen) 138 { 139 struct sctp_errhdr err; 140 __u16 len; 141 142 /* Cause code constants are now defined in network order. */ 143 err.cause = cause_code; 144 len = sizeof(err) + paylen; 145 err.length = htons(len); 146 147 if (skb_tailroom(chunk->skb) < len) 148 return -ENOSPC; 149 150 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(err), &err); 151 152 return 0; 153 } 154 155 /* 3.3.2 Initiation (INIT) (1) 156 * 157 * This chunk is used to initiate a SCTP association between two 158 * endpoints. The format of the INIT chunk is shown below: 159 * 160 * 0 1 2 3 161 * 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 1 162 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 163 * | Type = 1 | Chunk Flags | Chunk Length | 164 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 165 * | Initiate Tag | 166 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 167 * | Advertised Receiver Window Credit (a_rwnd) | 168 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 169 * | Number of Outbound Streams | Number of Inbound Streams | 170 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 171 * | Initial TSN | 172 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 173 * \ \ 174 * / Optional/Variable-Length Parameters / 175 * \ \ 176 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 177 * 178 * 179 * The INIT chunk contains the following parameters. Unless otherwise 180 * noted, each parameter MUST only be included once in the INIT chunk. 181 * 182 * Fixed Parameters Status 183 * ---------------------------------------------- 184 * Initiate Tag Mandatory 185 * Advertised Receiver Window Credit Mandatory 186 * Number of Outbound Streams Mandatory 187 * Number of Inbound Streams Mandatory 188 * Initial TSN Mandatory 189 * 190 * Variable Parameters Status Type Value 191 * ------------------------------------------------------------- 192 * IPv4 Address (Note 1) Optional 5 193 * IPv6 Address (Note 1) Optional 6 194 * Cookie Preservative Optional 9 195 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000) 196 * Host Name Address (Note 3) Optional 11 197 * Supported Address Types (Note 4) Optional 12 198 */ 199 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc, 200 const struct sctp_bind_addr *bp, 201 gfp_t gfp, int vparam_len) 202 { 203 struct sctp_supported_ext_param ext_param; 204 struct sctp_adaptation_ind_param aiparam; 205 struct sctp_paramhdr *auth_chunks = NULL; 206 struct sctp_paramhdr *auth_hmacs = NULL; 207 struct sctp_supported_addrs_param sat; 208 struct sctp_endpoint *ep = asoc->ep; 209 struct sctp_chunk *retval = NULL; 210 int num_types, addrs_len = 0; 211 struct sctp_inithdr init; 212 union sctp_params addrs; 213 struct sctp_sock *sp; 214 __u8 extensions[5]; 215 size_t chunksize; 216 __be16 types[2]; 217 int num_ext = 0; 218 219 /* RFC 2960 3.3.2 Initiation (INIT) (1) 220 * 221 * Note 1: The INIT chunks can contain multiple addresses that 222 * can be IPv4 and/or IPv6 in any combination. 223 */ 224 225 /* Convert the provided bind address list to raw format. */ 226 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp); 227 228 init.init_tag = htonl(asoc->c.my_vtag); 229 init.a_rwnd = htonl(asoc->rwnd); 230 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 231 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 232 init.initial_tsn = htonl(asoc->c.initial_tsn); 233 234 /* How many address types are needed? */ 235 sp = sctp_sk(asoc->base.sk); 236 num_types = sp->pf->supported_addrs(sp, types); 237 238 chunksize = sizeof(init) + addrs_len; 239 chunksize += SCTP_PAD4(SCTP_SAT_LEN(num_types)); 240 241 if (asoc->ep->ecn_enable) 242 chunksize += sizeof(ecap_param); 243 244 if (asoc->ep->prsctp_enable) 245 chunksize += sizeof(prsctp_param); 246 247 /* ADDIP: Section 4.2.7: 248 * An implementation supporting this extension [ADDIP] MUST list 249 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and 250 * INIT-ACK parameters. 251 */ 252 if (asoc->ep->asconf_enable) { 253 extensions[num_ext] = SCTP_CID_ASCONF; 254 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 255 num_ext += 2; 256 } 257 258 if (asoc->ep->reconf_enable) { 259 extensions[num_ext] = SCTP_CID_RECONF; 260 num_ext += 1; 261 } 262 263 if (sp->adaptation_ind) 264 chunksize += sizeof(aiparam); 265 266 if (asoc->ep->intl_enable) { 267 extensions[num_ext] = SCTP_CID_I_DATA; 268 num_ext += 1; 269 } 270 271 chunksize += vparam_len; 272 273 /* Account for AUTH related parameters */ 274 if (ep->auth_enable) { 275 /* Add random parameter length*/ 276 chunksize += sizeof(asoc->c.auth_random); 277 278 /* Add HMACS parameter length if any were defined */ 279 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; 280 if (auth_hmacs->length) 281 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 282 else 283 auth_hmacs = NULL; 284 285 /* Add CHUNKS parameter length */ 286 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; 287 if (auth_chunks->length) 288 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 289 else 290 auth_chunks = NULL; 291 292 extensions[num_ext] = SCTP_CID_AUTH; 293 num_ext += 1; 294 } 295 296 /* If we have any extensions to report, account for that */ 297 if (num_ext) 298 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext); 299 300 /* RFC 2960 3.3.2 Initiation (INIT) (1) 301 * 302 * Note 3: An INIT chunk MUST NOT contain more than one Host 303 * Name address parameter. Moreover, the sender of the INIT 304 * MUST NOT combine any other address types with the Host Name 305 * address in the INIT. The receiver of INIT MUST ignore any 306 * other address types if the Host Name address parameter is 307 * present in the received INIT chunk. 308 * 309 * PLEASE DO NOT FIXME [This version does not support Host Name.] 310 */ 311 312 retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp); 313 if (!retval) 314 goto nodata; 315 316 retval->subh.init_hdr = 317 sctp_addto_chunk(retval, sizeof(init), &init); 318 retval->param_hdr.v = 319 sctp_addto_chunk(retval, addrs_len, addrs.v); 320 321 /* RFC 2960 3.3.2 Initiation (INIT) (1) 322 * 323 * Note 4: This parameter, when present, specifies all the 324 * address types the sending endpoint can support. The absence 325 * of this parameter indicates that the sending endpoint can 326 * support any address type. 327 */ 328 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES; 329 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types)); 330 sctp_addto_chunk(retval, sizeof(sat), &sat); 331 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types); 332 333 if (asoc->ep->ecn_enable) 334 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 335 336 /* Add the supported extensions parameter. Be nice and add this 337 * fist before addiding the parameters for the extensions themselves 338 */ 339 if (num_ext) { 340 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 341 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext); 342 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); 343 sctp_addto_param(retval, num_ext, extensions); 344 } 345 346 if (asoc->ep->prsctp_enable) 347 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 348 349 if (sp->adaptation_ind) { 350 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 351 aiparam.param_hdr.length = htons(sizeof(aiparam)); 352 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 353 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 354 } 355 356 /* Add SCTP-AUTH chunks to the parameter list */ 357 if (ep->auth_enable) { 358 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random), 359 asoc->c.auth_random); 360 if (auth_hmacs) 361 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 362 auth_hmacs); 363 if (auth_chunks) 364 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 365 auth_chunks); 366 } 367 nodata: 368 kfree(addrs.v); 369 return retval; 370 } 371 372 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, 373 const struct sctp_chunk *chunk, 374 gfp_t gfp, int unkparam_len) 375 { 376 struct sctp_supported_ext_param ext_param; 377 struct sctp_adaptation_ind_param aiparam; 378 struct sctp_paramhdr *auth_chunks = NULL; 379 struct sctp_paramhdr *auth_random = NULL; 380 struct sctp_paramhdr *auth_hmacs = NULL; 381 struct sctp_chunk *retval = NULL; 382 struct sctp_cookie_param *cookie; 383 struct sctp_inithdr initack; 384 union sctp_params addrs; 385 struct sctp_sock *sp; 386 __u8 extensions[5]; 387 size_t chunksize; 388 int num_ext = 0; 389 int cookie_len; 390 int addrs_len; 391 392 /* Note: there may be no addresses to embed. */ 393 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp); 394 395 initack.init_tag = htonl(asoc->c.my_vtag); 396 initack.a_rwnd = htonl(asoc->rwnd); 397 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 398 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 399 initack.initial_tsn = htonl(asoc->c.initial_tsn); 400 401 /* FIXME: We really ought to build the cookie right 402 * into the packet instead of allocating more fresh memory. 403 */ 404 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len, 405 addrs.v, addrs_len); 406 if (!cookie) 407 goto nomem_cookie; 408 409 /* Calculate the total size of allocation, include the reserved 410 * space for reporting unknown parameters if it is specified. 411 */ 412 sp = sctp_sk(asoc->base.sk); 413 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len; 414 415 /* Tell peer that we'll do ECN only if peer advertised such cap. */ 416 if (asoc->peer.ecn_capable) 417 chunksize += sizeof(ecap_param); 418 419 if (asoc->peer.prsctp_capable) 420 chunksize += sizeof(prsctp_param); 421 422 if (asoc->peer.asconf_capable) { 423 extensions[num_ext] = SCTP_CID_ASCONF; 424 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 425 num_ext += 2; 426 } 427 428 if (asoc->peer.reconf_capable) { 429 extensions[num_ext] = SCTP_CID_RECONF; 430 num_ext += 1; 431 } 432 433 if (sp->adaptation_ind) 434 chunksize += sizeof(aiparam); 435 436 if (asoc->peer.intl_capable) { 437 extensions[num_ext] = SCTP_CID_I_DATA; 438 num_ext += 1; 439 } 440 441 if (asoc->peer.auth_capable) { 442 auth_random = (struct sctp_paramhdr *)asoc->c.auth_random; 443 chunksize += ntohs(auth_random->length); 444 445 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; 446 if (auth_hmacs->length) 447 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 448 else 449 auth_hmacs = NULL; 450 451 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; 452 if (auth_chunks->length) 453 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 454 else 455 auth_chunks = NULL; 456 457 extensions[num_ext] = SCTP_CID_AUTH; 458 num_ext += 1; 459 } 460 461 if (num_ext) 462 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext); 463 464 /* Now allocate and fill out the chunk. */ 465 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp); 466 if (!retval) 467 goto nomem_chunk; 468 469 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 470 * 471 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 472 * HEARTBEAT ACK, * etc.) to the same destination transport 473 * address from which it received the DATA or control chunk 474 * to which it is replying. 475 * 476 * [INIT ACK back to where the INIT came from.] 477 */ 478 if (chunk->transport) 479 retval->transport = 480 sctp_assoc_lookup_paddr(asoc, 481 &chunk->transport->ipaddr); 482 483 retval->subh.init_hdr = 484 sctp_addto_chunk(retval, sizeof(initack), &initack); 485 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); 486 sctp_addto_chunk(retval, cookie_len, cookie); 487 if (asoc->peer.ecn_capable) 488 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 489 if (num_ext) { 490 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 491 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext); 492 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); 493 sctp_addto_param(retval, num_ext, extensions); 494 } 495 if (asoc->peer.prsctp_capable) 496 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 497 498 if (sp->adaptation_ind) { 499 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 500 aiparam.param_hdr.length = htons(sizeof(aiparam)); 501 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 502 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 503 } 504 505 if (asoc->peer.auth_capable) { 506 sctp_addto_chunk(retval, ntohs(auth_random->length), 507 auth_random); 508 if (auth_hmacs) 509 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 510 auth_hmacs); 511 if (auth_chunks) 512 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 513 auth_chunks); 514 } 515 516 /* We need to remove the const qualifier at this point. */ 517 retval->asoc = (struct sctp_association *) asoc; 518 519 nomem_chunk: 520 kfree(cookie); 521 nomem_cookie: 522 kfree(addrs.v); 523 return retval; 524 } 525 526 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10): 527 * 528 * This chunk is used only during the initialization of an association. 529 * It is sent by the initiator of an association to its peer to complete 530 * the initialization process. This chunk MUST precede any DATA chunk 531 * sent within the association, but MAY be bundled with one or more DATA 532 * chunks in the same packet. 533 * 534 * 0 1 2 3 535 * 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 1 536 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 537 * | Type = 10 |Chunk Flags | Length | 538 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 539 * / Cookie / 540 * \ \ 541 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 542 * 543 * Chunk Flags: 8 bit 544 * 545 * Set to zero on transmit and ignored on receipt. 546 * 547 * Length: 16 bits (unsigned integer) 548 * 549 * Set to the size of the chunk in bytes, including the 4 bytes of 550 * the chunk header and the size of the Cookie. 551 * 552 * Cookie: variable size 553 * 554 * This field must contain the exact cookie received in the 555 * State Cookie parameter from the previous INIT ACK. 556 * 557 * An implementation SHOULD make the cookie as small as possible 558 * to insure interoperability. 559 */ 560 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, 561 const struct sctp_chunk *chunk) 562 { 563 struct sctp_chunk *retval; 564 int cookie_len; 565 void *cookie; 566 567 cookie = asoc->peer.cookie; 568 cookie_len = asoc->peer.cookie_len; 569 570 /* Build a cookie echo chunk. */ 571 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0, 572 cookie_len, GFP_ATOMIC); 573 if (!retval) 574 goto nodata; 575 retval->subh.cookie_hdr = 576 sctp_addto_chunk(retval, cookie_len, cookie); 577 578 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 579 * 580 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 581 * HEARTBEAT ACK, * etc.) to the same destination transport 582 * address from which it * received the DATA or control chunk 583 * to which it is replying. 584 * 585 * [COOKIE ECHO back to where the INIT ACK came from.] 586 */ 587 if (chunk) 588 retval->transport = chunk->transport; 589 590 nodata: 591 return retval; 592 } 593 594 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11): 595 * 596 * This chunk is used only during the initialization of an 597 * association. It is used to acknowledge the receipt of a COOKIE 598 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent 599 * within the association, but MAY be bundled with one or more DATA 600 * chunks or SACK chunk in the same SCTP packet. 601 * 602 * 0 1 2 3 603 * 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 1 604 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 605 * | Type = 11 |Chunk Flags | Length = 4 | 606 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 607 * 608 * Chunk Flags: 8 bits 609 * 610 * Set to zero on transmit and ignored on receipt. 611 */ 612 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, 613 const struct sctp_chunk *chunk) 614 { 615 struct sctp_chunk *retval; 616 617 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC); 618 619 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 620 * 621 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 622 * HEARTBEAT ACK, * etc.) to the same destination transport 623 * address from which it * received the DATA or control chunk 624 * to which it is replying. 625 * 626 * [COOKIE ACK back to where the COOKIE ECHO came from.] 627 */ 628 if (retval && chunk && chunk->transport) 629 retval->transport = 630 sctp_assoc_lookup_paddr(asoc, 631 &chunk->transport->ipaddr); 632 633 return retval; 634 } 635 636 /* 637 * Appendix A: Explicit Congestion Notification: 638 * CWR: 639 * 640 * RFC 2481 details a specific bit for a sender to send in the header of 641 * its next outbound TCP segment to indicate to its peer that it has 642 * reduced its congestion window. This is termed the CWR bit. For 643 * SCTP the same indication is made by including the CWR chunk. 644 * This chunk contains one data element, i.e. the TSN number that 645 * was sent in the ECNE chunk. This element represents the lowest 646 * TSN number in the datagram that was originally marked with the 647 * CE bit. 648 * 649 * 0 1 2 3 650 * 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 1 651 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 652 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 | 653 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 654 * | Lowest TSN Number | 655 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 656 * 657 * Note: The CWR is considered a Control chunk. 658 */ 659 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, 660 const __u32 lowest_tsn, 661 const struct sctp_chunk *chunk) 662 { 663 struct sctp_chunk *retval; 664 struct sctp_cwrhdr cwr; 665 666 cwr.lowest_tsn = htonl(lowest_tsn); 667 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0, 668 sizeof(cwr), GFP_ATOMIC); 669 670 if (!retval) 671 goto nodata; 672 673 retval->subh.ecn_cwr_hdr = 674 sctp_addto_chunk(retval, sizeof(cwr), &cwr); 675 676 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 677 * 678 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 679 * HEARTBEAT ACK, * etc.) to the same destination transport 680 * address from which it * received the DATA or control chunk 681 * to which it is replying. 682 * 683 * [Report a reduced congestion window back to where the ECNE 684 * came from.] 685 */ 686 if (chunk) 687 retval->transport = chunk->transport; 688 689 nodata: 690 return retval; 691 } 692 693 /* Make an ECNE chunk. This is a congestion experienced report. */ 694 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, 695 const __u32 lowest_tsn) 696 { 697 struct sctp_chunk *retval; 698 struct sctp_ecnehdr ecne; 699 700 ecne.lowest_tsn = htonl(lowest_tsn); 701 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0, 702 sizeof(ecne), GFP_ATOMIC); 703 if (!retval) 704 goto nodata; 705 retval->subh.ecne_hdr = 706 sctp_addto_chunk(retval, sizeof(ecne), &ecne); 707 708 nodata: 709 return retval; 710 } 711 712 /* Make a DATA chunk for the given association from the provided 713 * parameters. However, do not populate the data payload. 714 */ 715 struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc, 716 const struct sctp_sndrcvinfo *sinfo, 717 int len, __u8 flags, gfp_t gfp) 718 { 719 struct sctp_chunk *retval; 720 struct sctp_datahdr dp; 721 722 /* We assign the TSN as LATE as possible, not here when 723 * creating the chunk. 724 */ 725 memset(&dp, 0, sizeof(dp)); 726 dp.ppid = sinfo->sinfo_ppid; 727 dp.stream = htons(sinfo->sinfo_stream); 728 729 /* Set the flags for an unordered send. */ 730 if (sinfo->sinfo_flags & SCTP_UNORDERED) 731 flags |= SCTP_DATA_UNORDERED; 732 733 retval = sctp_make_data(asoc, flags, sizeof(dp) + len, gfp); 734 if (!retval) 735 return NULL; 736 737 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp); 738 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo)); 739 740 return retval; 741 } 742 743 /* Create a selective ackowledgement (SACK) for the given 744 * association. This reports on which TSN's we've seen to date, 745 * including duplicates and gaps. 746 */ 747 struct sctp_chunk *sctp_make_sack(struct sctp_association *asoc) 748 { 749 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; 750 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; 751 __u16 num_gabs, num_dup_tsns; 752 struct sctp_transport *trans; 753 struct sctp_chunk *retval; 754 struct sctp_sackhdr sack; 755 __u32 ctsn; 756 int len; 757 758 memset(gabs, 0, sizeof(gabs)); 759 ctsn = sctp_tsnmap_get_ctsn(map); 760 761 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn); 762 763 /* How much room is needed in the chunk? */ 764 num_gabs = sctp_tsnmap_num_gabs(map, gabs); 765 num_dup_tsns = sctp_tsnmap_num_dups(map); 766 767 /* Initialize the SACK header. */ 768 sack.cum_tsn_ack = htonl(ctsn); 769 sack.a_rwnd = htonl(asoc->a_rwnd); 770 sack.num_gap_ack_blocks = htons(num_gabs); 771 sack.num_dup_tsns = htons(num_dup_tsns); 772 773 len = sizeof(sack) 774 + sizeof(struct sctp_gap_ack_block) * num_gabs 775 + sizeof(__u32) * num_dup_tsns; 776 777 /* Create the chunk. */ 778 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC); 779 if (!retval) 780 goto nodata; 781 782 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 783 * 784 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 785 * HEARTBEAT ACK, etc.) to the same destination transport 786 * address from which it received the DATA or control chunk to 787 * which it is replying. This rule should also be followed if 788 * the endpoint is bundling DATA chunks together with the 789 * reply chunk. 790 * 791 * However, when acknowledging multiple DATA chunks received 792 * in packets from different source addresses in a single 793 * SACK, the SACK chunk may be transmitted to one of the 794 * destination transport addresses from which the DATA or 795 * control chunks being acknowledged were received. 796 * 797 * [BUG: We do not implement the following paragraph. 798 * Perhaps we should remember the last transport we used for a 799 * SACK and avoid that (if possible) if we have seen any 800 * duplicates. --piggy] 801 * 802 * When a receiver of a duplicate DATA chunk sends a SACK to a 803 * multi- homed endpoint it MAY be beneficial to vary the 804 * destination address and not use the source address of the 805 * DATA chunk. The reason being that receiving a duplicate 806 * from a multi-homed endpoint might indicate that the return 807 * path (as specified in the source address of the DATA chunk) 808 * for the SACK is broken. 809 * 810 * [Send to the address from which we last received a DATA chunk.] 811 */ 812 retval->transport = asoc->peer.last_data_from; 813 814 retval->subh.sack_hdr = 815 sctp_addto_chunk(retval, sizeof(sack), &sack); 816 817 /* Add the gap ack block information. */ 818 if (num_gabs) 819 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, 820 gabs); 821 822 /* Add the duplicate TSN information. */ 823 if (num_dup_tsns) { 824 asoc->stats.idupchunks += num_dup_tsns; 825 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, 826 sctp_tsnmap_get_dups(map)); 827 } 828 /* Once we have a sack generated, check to see what our sack 829 * generation is, if its 0, reset the transports to 0, and reset 830 * the association generation to 1 831 * 832 * The idea is that zero is never used as a valid generation for the 833 * association so no transport will match after a wrap event like this, 834 * Until the next sack 835 */ 836 if (++asoc->peer.sack_generation == 0) { 837 list_for_each_entry(trans, &asoc->peer.transport_addr_list, 838 transports) 839 trans->sack_generation = 0; 840 asoc->peer.sack_generation = 1; 841 } 842 nodata: 843 return retval; 844 } 845 846 /* Make a SHUTDOWN chunk. */ 847 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 848 const struct sctp_chunk *chunk) 849 { 850 struct sctp_shutdownhdr shut; 851 struct sctp_chunk *retval; 852 __u32 ctsn; 853 854 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 855 shut.cum_tsn_ack = htonl(ctsn); 856 857 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0, 858 sizeof(shut), GFP_ATOMIC); 859 if (!retval) 860 goto nodata; 861 862 retval->subh.shutdown_hdr = 863 sctp_addto_chunk(retval, sizeof(shut), &shut); 864 865 if (chunk) 866 retval->transport = chunk->transport; 867 nodata: 868 return retval; 869 } 870 871 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 872 const struct sctp_chunk *chunk) 873 { 874 struct sctp_chunk *retval; 875 876 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0, 877 GFP_ATOMIC); 878 879 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 880 * 881 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 882 * HEARTBEAT ACK, * etc.) to the same destination transport 883 * address from which it * received the DATA or control chunk 884 * to which it is replying. 885 * 886 * [ACK back to where the SHUTDOWN came from.] 887 */ 888 if (retval && chunk) 889 retval->transport = chunk->transport; 890 891 return retval; 892 } 893 894 struct sctp_chunk *sctp_make_shutdown_complete( 895 const struct sctp_association *asoc, 896 const struct sctp_chunk *chunk) 897 { 898 struct sctp_chunk *retval; 899 __u8 flags = 0; 900 901 /* Set the T-bit if we have no association (vtag will be 902 * reflected) 903 */ 904 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; 905 906 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 907 0, GFP_ATOMIC); 908 909 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 910 * 911 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 912 * HEARTBEAT ACK, * etc.) to the same destination transport 913 * address from which it * received the DATA or control chunk 914 * to which it is replying. 915 * 916 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK 917 * came from.] 918 */ 919 if (retval && chunk) 920 retval->transport = chunk->transport; 921 922 return retval; 923 } 924 925 /* Create an ABORT. Note that we set the T bit if we have no 926 * association, except when responding to an INIT (sctpimpguide 2.41). 927 */ 928 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 929 const struct sctp_chunk *chunk, 930 const size_t hint) 931 { 932 struct sctp_chunk *retval; 933 __u8 flags = 0; 934 935 /* Set the T-bit if we have no association and 'chunk' is not 936 * an INIT (vtag will be reflected). 937 */ 938 if (!asoc) { 939 if (chunk && chunk->chunk_hdr && 940 chunk->chunk_hdr->type == SCTP_CID_INIT) 941 flags = 0; 942 else 943 flags = SCTP_CHUNK_FLAG_T; 944 } 945 946 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint, 947 GFP_ATOMIC); 948 949 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 950 * 951 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 952 * HEARTBEAT ACK, * etc.) to the same destination transport 953 * address from which it * received the DATA or control chunk 954 * to which it is replying. 955 * 956 * [ABORT back to where the offender came from.] 957 */ 958 if (retval && chunk) 959 retval->transport = chunk->transport; 960 961 return retval; 962 } 963 964 /* Helper to create ABORT with a NO_USER_DATA error. */ 965 struct sctp_chunk *sctp_make_abort_no_data( 966 const struct sctp_association *asoc, 967 const struct sctp_chunk *chunk, 968 __u32 tsn) 969 { 970 struct sctp_chunk *retval; 971 __be32 payload; 972 973 retval = sctp_make_abort(asoc, chunk, 974 sizeof(struct sctp_errhdr) + sizeof(tsn)); 975 976 if (!retval) 977 goto no_mem; 978 979 /* Put the tsn back into network byte order. */ 980 payload = htonl(tsn); 981 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload)); 982 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload); 983 984 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 985 * 986 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 987 * HEARTBEAT ACK, * etc.) to the same destination transport 988 * address from which it * received the DATA or control chunk 989 * to which it is replying. 990 * 991 * [ABORT back to where the offender came from.] 992 */ 993 if (chunk) 994 retval->transport = chunk->transport; 995 996 no_mem: 997 return retval; 998 } 999 1000 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ 1001 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 1002 struct msghdr *msg, 1003 size_t paylen) 1004 { 1005 struct sctp_chunk *retval; 1006 void *payload = NULL; 1007 int err; 1008 1009 retval = sctp_make_abort(asoc, NULL, 1010 sizeof(struct sctp_errhdr) + paylen); 1011 if (!retval) 1012 goto err_chunk; 1013 1014 if (paylen) { 1015 /* Put the msg_iov together into payload. */ 1016 payload = kmalloc(paylen, GFP_KERNEL); 1017 if (!payload) 1018 goto err_payload; 1019 1020 err = memcpy_from_msg(payload, msg, paylen); 1021 if (err < 0) 1022 goto err_copy; 1023 } 1024 1025 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); 1026 sctp_addto_chunk(retval, paylen, payload); 1027 1028 if (paylen) 1029 kfree(payload); 1030 1031 return retval; 1032 1033 err_copy: 1034 kfree(payload); 1035 err_payload: 1036 sctp_chunk_free(retval); 1037 retval = NULL; 1038 err_chunk: 1039 return retval; 1040 } 1041 1042 /* Append bytes to the end of a parameter. Will panic if chunk is not big 1043 * enough. 1044 */ 1045 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 1046 const void *data) 1047 { 1048 int chunklen = ntohs(chunk->chunk_hdr->length); 1049 void *target; 1050 1051 target = skb_put(chunk->skb, len); 1052 1053 if (data) 1054 memcpy(target, data, len); 1055 else 1056 memset(target, 0, len); 1057 1058 /* Adjust the chunk length field. */ 1059 chunk->chunk_hdr->length = htons(chunklen + len); 1060 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1061 1062 return target; 1063 } 1064 1065 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ 1066 struct sctp_chunk *sctp_make_abort_violation( 1067 const struct sctp_association *asoc, 1068 const struct sctp_chunk *chunk, 1069 const __u8 *payload, 1070 const size_t paylen) 1071 { 1072 struct sctp_chunk *retval; 1073 struct sctp_paramhdr phdr; 1074 1075 retval = sctp_make_abort(asoc, chunk, sizeof(struct sctp_errhdr) + 1076 paylen + sizeof(phdr)); 1077 if (!retval) 1078 goto end; 1079 1080 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen + 1081 sizeof(phdr)); 1082 1083 phdr.type = htons(chunk->chunk_hdr->type); 1084 phdr.length = chunk->chunk_hdr->length; 1085 sctp_addto_chunk(retval, paylen, payload); 1086 sctp_addto_param(retval, sizeof(phdr), &phdr); 1087 1088 end: 1089 return retval; 1090 } 1091 1092 struct sctp_chunk *sctp_make_violation_paramlen( 1093 const struct sctp_association *asoc, 1094 const struct sctp_chunk *chunk, 1095 struct sctp_paramhdr *param) 1096 { 1097 static const char error[] = "The following parameter had invalid length:"; 1098 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr) + 1099 sizeof(*param); 1100 struct sctp_chunk *retval; 1101 1102 retval = sctp_make_abort(asoc, chunk, payload_len); 1103 if (!retval) 1104 goto nodata; 1105 1106 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, 1107 sizeof(error) + sizeof(*param)); 1108 sctp_addto_chunk(retval, sizeof(error), error); 1109 sctp_addto_param(retval, sizeof(*param), param); 1110 1111 nodata: 1112 return retval; 1113 } 1114 1115 struct sctp_chunk *sctp_make_violation_max_retrans( 1116 const struct sctp_association *asoc, 1117 const struct sctp_chunk *chunk) 1118 { 1119 static const char error[] = "Association exceeded its max_retrans count"; 1120 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr); 1121 struct sctp_chunk *retval; 1122 1123 retval = sctp_make_abort(asoc, chunk, payload_len); 1124 if (!retval) 1125 goto nodata; 1126 1127 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error)); 1128 sctp_addto_chunk(retval, sizeof(error), error); 1129 1130 nodata: 1131 return retval; 1132 } 1133 1134 struct sctp_chunk *sctp_make_new_encap_port(const struct sctp_association *asoc, 1135 const struct sctp_chunk *chunk) 1136 { 1137 struct sctp_new_encap_port_hdr nep; 1138 struct sctp_chunk *retval; 1139 1140 retval = sctp_make_abort(asoc, chunk, 1141 sizeof(struct sctp_errhdr) + sizeof(nep)); 1142 if (!retval) 1143 goto nodata; 1144 1145 sctp_init_cause(retval, SCTP_ERROR_NEW_ENCAP_PORT, sizeof(nep)); 1146 nep.cur_port = SCTP_INPUT_CB(chunk->skb)->encap_port; 1147 nep.new_port = chunk->transport->encap_port; 1148 sctp_addto_chunk(retval, sizeof(nep), &nep); 1149 1150 nodata: 1151 return retval; 1152 } 1153 1154 /* Make a HEARTBEAT chunk. */ 1155 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1156 const struct sctp_transport *transport, 1157 __u32 probe_size) 1158 { 1159 struct sctp_sender_hb_info hbinfo = {}; 1160 struct sctp_chunk *retval; 1161 1162 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, 1163 sizeof(hbinfo), GFP_ATOMIC); 1164 1165 if (!retval) 1166 goto nodata; 1167 1168 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; 1169 hbinfo.param_hdr.length = htons(sizeof(hbinfo)); 1170 hbinfo.daddr = transport->ipaddr; 1171 hbinfo.sent_at = jiffies; 1172 hbinfo.hb_nonce = transport->hb_nonce; 1173 hbinfo.probe_size = probe_size; 1174 1175 /* Cast away the 'const', as this is just telling the chunk 1176 * what transport it belongs to. 1177 */ 1178 retval->transport = (struct sctp_transport *) transport; 1179 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo), 1180 &hbinfo); 1181 retval->pmtu_probe = !!probe_size; 1182 1183 nodata: 1184 return retval; 1185 } 1186 1187 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1188 const struct sctp_chunk *chunk, 1189 const void *payload, 1190 const size_t paylen) 1191 { 1192 struct sctp_chunk *retval; 1193 1194 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen, 1195 GFP_ATOMIC); 1196 if (!retval) 1197 goto nodata; 1198 1199 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1200 1201 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1202 * 1203 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1204 * HEARTBEAT ACK, * etc.) to the same destination transport 1205 * address from which it * received the DATA or control chunk 1206 * to which it is replying. 1207 * 1208 * [HBACK back to where the HEARTBEAT came from.] 1209 */ 1210 if (chunk) 1211 retval->transport = chunk->transport; 1212 1213 nodata: 1214 return retval; 1215 } 1216 1217 /* RFC4820 3. Padding Chunk (PAD) 1218 * 0 1 2 3 1219 * 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 1220 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1221 * | Type = 0x84 | Flags=0 | Length | 1222 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1223 * | | 1224 * \ Padding Data / 1225 * / \ 1226 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1227 */ 1228 struct sctp_chunk *sctp_make_pad(const struct sctp_association *asoc, int len) 1229 { 1230 struct sctp_chunk *retval; 1231 1232 retval = sctp_make_control(asoc, SCTP_CID_PAD, 0, len, GFP_ATOMIC); 1233 if (!retval) 1234 return NULL; 1235 1236 skb_put_zero(retval->skb, len); 1237 retval->chunk_hdr->length = htons(ntohs(retval->chunk_hdr->length) + len); 1238 retval->chunk_end = skb_tail_pointer(retval->skb); 1239 1240 return retval; 1241 } 1242 1243 /* Create an Operation Error chunk with the specified space reserved. 1244 * This routine can be used for containing multiple causes in the chunk. 1245 */ 1246 static struct sctp_chunk *sctp_make_op_error_space( 1247 const struct sctp_association *asoc, 1248 const struct sctp_chunk *chunk, 1249 size_t size) 1250 { 1251 struct sctp_chunk *retval; 1252 1253 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0, 1254 sizeof(struct sctp_errhdr) + size, 1255 GFP_ATOMIC); 1256 if (!retval) 1257 goto nodata; 1258 1259 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1260 * 1261 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1262 * HEARTBEAT ACK, etc.) to the same destination transport 1263 * address from which it received the DATA or control chunk 1264 * to which it is replying. 1265 * 1266 */ 1267 if (chunk) 1268 retval->transport = chunk->transport; 1269 1270 nodata: 1271 return retval; 1272 } 1273 1274 /* Create an Operation Error chunk of a fixed size, specifically, 1275 * min(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) - overheads. 1276 * This is a helper function to allocate an error chunk for those 1277 * invalid parameter codes in which we may not want to report all the 1278 * errors, if the incoming chunk is large. If it can't fit in a single 1279 * packet, we ignore it. 1280 */ 1281 static inline struct sctp_chunk *sctp_make_op_error_limited( 1282 const struct sctp_association *asoc, 1283 const struct sctp_chunk *chunk) 1284 { 1285 size_t size = SCTP_DEFAULT_MAXSEGMENT; 1286 struct sctp_sock *sp = NULL; 1287 1288 if (asoc) { 1289 size = min_t(size_t, size, asoc->pathmtu); 1290 sp = sctp_sk(asoc->base.sk); 1291 } 1292 1293 size = sctp_mtu_payload(sp, size, sizeof(struct sctp_errhdr)); 1294 1295 return sctp_make_op_error_space(asoc, chunk, size); 1296 } 1297 1298 /* Create an Operation Error chunk. */ 1299 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1300 const struct sctp_chunk *chunk, 1301 __be16 cause_code, const void *payload, 1302 size_t paylen, size_t reserve_tail) 1303 { 1304 struct sctp_chunk *retval; 1305 1306 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); 1307 if (!retval) 1308 goto nodata; 1309 1310 sctp_init_cause(retval, cause_code, paylen + reserve_tail); 1311 sctp_addto_chunk(retval, paylen, payload); 1312 if (reserve_tail) 1313 sctp_addto_param(retval, reserve_tail, NULL); 1314 1315 nodata: 1316 return retval; 1317 } 1318 1319 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc, 1320 __u16 key_id) 1321 { 1322 struct sctp_authhdr auth_hdr; 1323 const struct sctp_hmac *hmac_desc; 1324 struct sctp_chunk *retval; 1325 1326 /* Get the first hmac that the peer told us to use */ 1327 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1328 if (unlikely(!hmac_desc)) 1329 return NULL; 1330 1331 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0, 1332 hmac_desc->hmac_len + sizeof(auth_hdr), 1333 GFP_ATOMIC); 1334 if (!retval) 1335 return NULL; 1336 1337 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1338 auth_hdr.shkey_id = htons(key_id); 1339 1340 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr), 1341 &auth_hdr); 1342 1343 skb_put_zero(retval->skb, hmac_desc->hmac_len); 1344 1345 /* Adjust the chunk header to include the empty MAC */ 1346 retval->chunk_hdr->length = 1347 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1348 retval->chunk_end = skb_tail_pointer(retval->skb); 1349 1350 return retval; 1351 } 1352 1353 1354 /******************************************************************** 1355 * 2nd Level Abstractions 1356 ********************************************************************/ 1357 1358 /* Turn an skb into a chunk. 1359 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1360 * 1361 * sctpimpguide-05.txt Section 2.8.2 1362 * M1) Each time a new DATA chunk is transmitted 1363 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1364 * 'TSN.Missing.Report' count will be used to determine missing chunks 1365 * and when to fast retransmit. 1366 * 1367 */ 1368 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1369 const struct sctp_association *asoc, 1370 struct sock *sk, gfp_t gfp) 1371 { 1372 struct sctp_chunk *retval; 1373 1374 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp); 1375 1376 if (!retval) 1377 goto nodata; 1378 if (!sk) 1379 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb); 1380 1381 INIT_LIST_HEAD(&retval->list); 1382 retval->skb = skb; 1383 retval->asoc = (struct sctp_association *)asoc; 1384 retval->singleton = 1; 1385 1386 retval->fast_retransmit = SCTP_CAN_FRTX; 1387 1388 /* Polish the bead hole. */ 1389 INIT_LIST_HEAD(&retval->transmitted_list); 1390 INIT_LIST_HEAD(&retval->frag_list); 1391 SCTP_DBG_OBJCNT_INC(chunk); 1392 refcount_set(&retval->refcnt, 1); 1393 1394 nodata: 1395 return retval; 1396 } 1397 1398 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1399 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1400 union sctp_addr *dest) 1401 { 1402 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1403 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1404 } 1405 1406 /* Extract the source address from a chunk. */ 1407 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1408 { 1409 /* If we have a known transport, use that. */ 1410 if (chunk->transport) { 1411 return &chunk->transport->ipaddr; 1412 } else { 1413 /* Otherwise, extract it from the IP header. */ 1414 return &chunk->source; 1415 } 1416 } 1417 1418 /* Create a new chunk, setting the type and flags headers from the 1419 * arguments, reserving enough space for a 'paylen' byte payload. 1420 */ 1421 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 1422 __u8 type, __u8 flags, int paylen, 1423 gfp_t gfp) 1424 { 1425 struct sctp_chunkhdr *chunk_hdr; 1426 struct sctp_chunk *retval; 1427 struct sk_buff *skb; 1428 struct sock *sk; 1429 int chunklen; 1430 1431 chunklen = SCTP_PAD4(sizeof(*chunk_hdr) + paylen); 1432 if (chunklen > SCTP_MAX_CHUNK_LEN) 1433 goto nodata; 1434 1435 /* No need to allocate LL here, as this is only a chunk. */ 1436 skb = alloc_skb(chunklen, gfp); 1437 if (!skb) 1438 goto nodata; 1439 1440 /* Make room for the chunk header. */ 1441 chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr)); 1442 chunk_hdr->type = type; 1443 chunk_hdr->flags = flags; 1444 chunk_hdr->length = htons(sizeof(*chunk_hdr)); 1445 1446 sk = asoc ? asoc->base.sk : NULL; 1447 retval = sctp_chunkify(skb, asoc, sk, gfp); 1448 if (!retval) { 1449 kfree_skb(skb); 1450 goto nodata; 1451 } 1452 1453 retval->chunk_hdr = chunk_hdr; 1454 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr); 1455 1456 /* Determine if the chunk needs to be authenticated */ 1457 if (sctp_auth_send_cid(type, asoc)) 1458 retval->auth = 1; 1459 1460 return retval; 1461 nodata: 1462 return NULL; 1463 } 1464 1465 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 1466 __u8 flags, int paylen, gfp_t gfp) 1467 { 1468 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp); 1469 } 1470 1471 struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc, 1472 __u8 flags, int paylen, gfp_t gfp) 1473 { 1474 return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp); 1475 } 1476 1477 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 1478 __u8 type, __u8 flags, int paylen, 1479 gfp_t gfp) 1480 { 1481 struct sctp_chunk *chunk; 1482 1483 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp); 1484 if (chunk) 1485 sctp_control_set_owner_w(chunk); 1486 1487 return chunk; 1488 } 1489 1490 /* Release the memory occupied by a chunk. */ 1491 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1492 { 1493 BUG_ON(!list_empty(&chunk->list)); 1494 list_del_init(&chunk->transmitted_list); 1495 1496 consume_skb(chunk->skb); 1497 consume_skb(chunk->auth_chunk); 1498 1499 SCTP_DBG_OBJCNT_DEC(chunk); 1500 kmem_cache_free(sctp_chunk_cachep, chunk); 1501 } 1502 1503 /* Possibly, free the chunk. */ 1504 void sctp_chunk_free(struct sctp_chunk *chunk) 1505 { 1506 /* Release our reference on the message tracker. */ 1507 if (chunk->msg) 1508 sctp_datamsg_put(chunk->msg); 1509 1510 sctp_chunk_put(chunk); 1511 } 1512 1513 /* Grab a reference to the chunk. */ 1514 void sctp_chunk_hold(struct sctp_chunk *ch) 1515 { 1516 refcount_inc(&ch->refcnt); 1517 } 1518 1519 /* Release a reference to the chunk. */ 1520 void sctp_chunk_put(struct sctp_chunk *ch) 1521 { 1522 if (refcount_dec_and_test(&ch->refcnt)) 1523 sctp_chunk_destroy(ch); 1524 } 1525 1526 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1527 * enough. 1528 */ 1529 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1530 { 1531 int chunklen = ntohs(chunk->chunk_hdr->length); 1532 int padlen = SCTP_PAD4(chunklen) - chunklen; 1533 void *target; 1534 1535 skb_put_zero(chunk->skb, padlen); 1536 target = skb_put_data(chunk->skb, data, len); 1537 1538 /* Adjust the chunk length field. */ 1539 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1540 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1541 1542 return target; 1543 } 1544 1545 /* Append bytes from user space to the end of a chunk. Will panic if 1546 * chunk is not big enough. 1547 * Returns a kernel err value. 1548 */ 1549 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len, 1550 struct iov_iter *from) 1551 { 1552 void *target; 1553 1554 /* Make room in chunk for data. */ 1555 target = skb_put(chunk->skb, len); 1556 1557 /* Copy data (whole iovec) into chunk */ 1558 if (!copy_from_iter_full(target, len, from)) 1559 return -EFAULT; 1560 1561 /* Adjust the chunk length field. */ 1562 chunk->chunk_hdr->length = 1563 htons(ntohs(chunk->chunk_hdr->length) + len); 1564 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1565 1566 return 0; 1567 } 1568 1569 /* Helper function to assign a TSN if needed. This assumes that both 1570 * the data_hdr and association have already been assigned. 1571 */ 1572 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1573 { 1574 struct sctp_stream *stream; 1575 struct sctp_chunk *lchunk; 1576 struct sctp_datamsg *msg; 1577 __u16 ssn, sid; 1578 1579 if (chunk->has_ssn) 1580 return; 1581 1582 /* All fragments will be on the same stream */ 1583 sid = ntohs(chunk->subh.data_hdr->stream); 1584 stream = &chunk->asoc->stream; 1585 1586 /* Now assign the sequence number to the entire message. 1587 * All fragments must have the same stream sequence number. 1588 */ 1589 msg = chunk->msg; 1590 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1591 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1592 ssn = 0; 1593 } else { 1594 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1595 ssn = sctp_ssn_next(stream, out, sid); 1596 else 1597 ssn = sctp_ssn_peek(stream, out, sid); 1598 } 1599 1600 lchunk->subh.data_hdr->ssn = htons(ssn); 1601 lchunk->has_ssn = 1; 1602 } 1603 } 1604 1605 /* Helper function to assign a TSN if needed. This assumes that both 1606 * the data_hdr and association have already been assigned. 1607 */ 1608 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1609 { 1610 if (!chunk->has_tsn) { 1611 /* This is the last possible instant to 1612 * assign a TSN. 1613 */ 1614 chunk->subh.data_hdr->tsn = 1615 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1616 chunk->has_tsn = 1; 1617 } 1618 } 1619 1620 /* Create a CLOSED association to use with an incoming packet. */ 1621 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1622 struct sctp_chunk *chunk, 1623 gfp_t gfp) 1624 { 1625 struct sctp_association *asoc; 1626 enum sctp_scope scope; 1627 struct sk_buff *skb; 1628 1629 /* Create the bare association. */ 1630 scope = sctp_scope(sctp_source(chunk)); 1631 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1632 if (!asoc) 1633 goto nodata; 1634 asoc->temp = 1; 1635 skb = chunk->skb; 1636 /* Create an entry for the source address of the packet. */ 1637 SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1); 1638 1639 nodata: 1640 return asoc; 1641 } 1642 1643 /* Build a cookie representing asoc. 1644 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1645 */ 1646 static struct sctp_cookie_param *sctp_pack_cookie( 1647 const struct sctp_endpoint *ep, 1648 const struct sctp_association *asoc, 1649 const struct sctp_chunk *init_chunk, 1650 int *cookie_len, const __u8 *raw_addrs, 1651 int addrs_len) 1652 { 1653 struct sctp_signed_cookie *cookie; 1654 struct sctp_cookie_param *retval; 1655 int headersize, bodysize; 1656 1657 /* Header size is static data prior to the actual cookie, including 1658 * any padding. 1659 */ 1660 headersize = sizeof(struct sctp_paramhdr) + 1661 (sizeof(struct sctp_signed_cookie) - 1662 sizeof(struct sctp_cookie)); 1663 bodysize = sizeof(struct sctp_cookie) 1664 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1665 1666 /* Pad out the cookie to a multiple to make the signature 1667 * functions simpler to write. 1668 */ 1669 if (bodysize % SCTP_COOKIE_MULTIPLE) 1670 bodysize += SCTP_COOKIE_MULTIPLE 1671 - (bodysize % SCTP_COOKIE_MULTIPLE); 1672 *cookie_len = headersize + bodysize; 1673 1674 /* Clear this memory since we are sending this data structure 1675 * out on the network. 1676 */ 1677 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1678 if (!retval) { 1679 *cookie_len = 0; 1680 return NULL; 1681 } 1682 1683 cookie = (struct sctp_signed_cookie *) retval->body; 1684 1685 /* Set up the parameter header. */ 1686 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1687 retval->p.length = htons(*cookie_len); 1688 1689 /* Copy the cookie part of the association itself. */ 1690 cookie->c = asoc->c; 1691 /* Save the raw address list length in the cookie. */ 1692 cookie->c.raw_addr_list_len = addrs_len; 1693 1694 /* Remember PR-SCTP capability. */ 1695 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1696 1697 /* Save adaptation indication in the cookie. */ 1698 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1699 1700 /* Set an expiration time for the cookie. */ 1701 cookie->c.expiration = ktime_add(asoc->cookie_life, 1702 ktime_get_real()); 1703 1704 /* Copy the peer's init packet. */ 1705 memcpy(cookie + 1, init_chunk->chunk_hdr, 1706 ntohs(init_chunk->chunk_hdr->length)); 1707 1708 /* Copy the raw local address list of the association. */ 1709 memcpy((__u8 *)(cookie + 1) + 1710 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1711 1712 /* Sign the cookie, if cookie authentication is enabled. */ 1713 if (sctp_sk(ep->base.sk)->cookie_auth_enable) { 1714 static_assert(sizeof(cookie->mac) == SHA256_DIGEST_SIZE); 1715 hmac_sha256(&ep->cookie_auth_key, (const u8 *)&cookie->c, 1716 bodysize, cookie->mac); 1717 } 1718 1719 return retval; 1720 } 1721 1722 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1723 struct sctp_association *sctp_unpack_cookie( 1724 const struct sctp_endpoint *ep, 1725 const struct sctp_association *asoc, 1726 struct sctp_chunk *chunk, gfp_t gfp, 1727 int *error, struct sctp_chunk **errp) 1728 { 1729 struct sctp_association *retval = NULL; 1730 int headersize, bodysize, fixed_size; 1731 struct sctp_signed_cookie *cookie; 1732 struct sk_buff *skb = chunk->skb; 1733 struct sctp_cookie *bear_cookie; 1734 struct sctp_chunkhdr *ch; 1735 unsigned int len, chlen; 1736 union sctp_addr paddr; 1737 enum sctp_scope scope; 1738 struct sctp_af *af; 1739 ktime_t kt; 1740 1741 /* Header size is static data prior to the actual cookie, including 1742 * any padding. 1743 */ 1744 headersize = sizeof(struct sctp_chunkhdr) + 1745 (sizeof(struct sctp_signed_cookie) - 1746 sizeof(struct sctp_cookie)); 1747 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1748 fixed_size = headersize + sizeof(struct sctp_cookie); 1749 1750 /* Verify that the chunk looks like it even has a cookie. 1751 * There must be enough room for our cookie and our peer's 1752 * INIT chunk. 1753 */ 1754 len = ntohs(chunk->chunk_hdr->length); 1755 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1756 goto malformed; 1757 1758 /* Verify that the cookie has been padded out. */ 1759 if (bodysize % SCTP_COOKIE_MULTIPLE) 1760 goto malformed; 1761 1762 /* Process the cookie. */ 1763 cookie = chunk->subh.cookie_hdr; 1764 bear_cookie = &cookie->c; 1765 1766 ch = (struct sctp_chunkhdr *)(bear_cookie + 1); 1767 if (ch->type != SCTP_CID_INIT) 1768 goto malformed; 1769 chlen = ntohs(ch->length); 1770 if (chlen < sizeof(struct sctp_init_chunk)) 1771 goto malformed; 1772 if (chlen > len - fixed_size) 1773 goto malformed; 1774 if (bear_cookie->raw_addr_list_len > len - fixed_size - chlen) 1775 goto malformed; 1776 1777 /* Verify the cookie's MAC, if cookie authentication is enabled. */ 1778 if (sctp_sk(ep->base.sk)->cookie_auth_enable) { 1779 u8 mac[SHA256_DIGEST_SIZE]; 1780 1781 hmac_sha256(&ep->cookie_auth_key, (const u8 *)bear_cookie, 1782 bodysize, mac); 1783 static_assert(sizeof(cookie->mac) == sizeof(mac)); 1784 if (crypto_memneq(mac, cookie->mac, sizeof(mac))) { 1785 *error = -SCTP_IERROR_BAD_SIG; 1786 goto fail; 1787 } 1788 } 1789 1790 /* IG Section 2.35.2: 1791 * 3) Compare the port numbers and the verification tag contained 1792 * within the COOKIE ECHO chunk to the actual port numbers and the 1793 * verification tag within the SCTP common header of the received 1794 * packet. If these values do not match the packet MUST be silently 1795 * discarded, 1796 */ 1797 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1798 *error = -SCTP_IERROR_BAD_TAG; 1799 goto fail; 1800 } 1801 1802 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1803 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1804 *error = -SCTP_IERROR_BAD_PORTS; 1805 goto fail; 1806 } 1807 1808 /* Check to see if the cookie is stale. RFC 9260 Section 5.2.4 1809 * exempts an expired cookie only when both Verification Tags match 1810 * the current association. 1811 * If skb has been timestamped, then use the stamp, otherwise 1812 * use current time. This introduces a small possibility that 1813 * a cookie may be considered expired, but this would only slow 1814 * down the new association establishment instead of every packet. 1815 */ 1816 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1817 kt = skb_get_ktime(skb); 1818 else 1819 kt = ktime_get_real(); 1820 1821 if ((!asoc || 1822 asoc->c.my_vtag != bear_cookie->my_vtag || 1823 asoc->c.peer_vtag != bear_cookie->peer_vtag) && 1824 ktime_before(bear_cookie->expiration, kt)) { 1825 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); 1826 __be32 n = htonl(usecs); 1827 1828 /* 1829 * Section 3.3.10.3 Stale Cookie Error (3) 1830 * 1831 * Cause of error 1832 * --------------- 1833 * Stale Cookie Error: Indicates the receipt of a valid State 1834 * Cookie that has expired. 1835 */ 1836 *errp = sctp_make_op_error(asoc, chunk, 1837 SCTP_ERROR_STALE_COOKIE, &n, 1838 sizeof(n), 0); 1839 if (*errp) 1840 *error = -SCTP_IERROR_STALE_COOKIE; 1841 else 1842 *error = -SCTP_IERROR_NOMEM; 1843 1844 goto fail; 1845 } 1846 1847 paddr = bear_cookie->peer_addr; 1848 af = sctp_get_af_specific(paddr.sa.sa_family); 1849 if (!af || !af->addr_valid(&paddr, sctp_sk(ep->base.sk), NULL)) 1850 goto malformed; 1851 1852 /* Make a new base association. */ 1853 scope = sctp_scope(sctp_source(chunk)); 1854 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1855 if (!retval) { 1856 *error = -SCTP_IERROR_NOMEM; 1857 goto fail; 1858 } 1859 1860 /* Set up our peer's port number. */ 1861 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1862 1863 if (!sctp_auth_verify_cookie_params(ep, bear_cookie)) 1864 goto malformed; 1865 1866 /* Populate the association from the cookie. */ 1867 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1868 retval->c.peer_addr = paddr; 1869 1870 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1871 GFP_ATOMIC) < 0) { 1872 *error = -SCTP_IERROR_NOMEM; 1873 goto fail; 1874 } 1875 1876 /* Also, add the destination address. */ 1877 if (list_empty(&retval->base.bind_addr.address_list)) { 1878 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1879 sizeof(chunk->dest), SCTP_ADDR_SRC, 1880 GFP_ATOMIC); 1881 } 1882 1883 retval->next_tsn = retval->c.initial_tsn; 1884 retval->ctsn_ack_point = retval->next_tsn - 1; 1885 retval->addip_serial = retval->c.initial_tsn; 1886 retval->strreset_outseq = retval->c.initial_tsn; 1887 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1888 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1889 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1890 1891 /* The INIT stuff will be done by the side effects. */ 1892 return retval; 1893 1894 fail: 1895 if (retval) 1896 sctp_association_free(retval); 1897 1898 return NULL; 1899 1900 malformed: 1901 /* Yikes! The packet is either corrupt or deliberately 1902 * malformed. 1903 */ 1904 *error = -SCTP_IERROR_MALFORMED; 1905 goto fail; 1906 } 1907 1908 /******************************************************************** 1909 * 3rd Level Abstractions 1910 ********************************************************************/ 1911 1912 struct __sctp_missing { 1913 __be32 num_missing; 1914 __be16 type; 1915 } __packed; 1916 1917 /* 1918 * Report a missing mandatory parameter. 1919 */ 1920 static int sctp_process_missing_param(const struct sctp_association *asoc, 1921 enum sctp_param paramtype, 1922 struct sctp_chunk *chunk, 1923 struct sctp_chunk **errp) 1924 { 1925 struct __sctp_missing report; 1926 __u16 len; 1927 1928 len = SCTP_PAD4(sizeof(report)); 1929 1930 /* Make an ERROR chunk, preparing enough room for 1931 * returning multiple unknown parameters. 1932 */ 1933 if (!*errp) 1934 *errp = sctp_make_op_error_space(asoc, chunk, len); 1935 1936 if (*errp) { 1937 report.num_missing = htonl(1); 1938 report.type = paramtype; 1939 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1940 sizeof(report)); 1941 sctp_addto_chunk(*errp, sizeof(report), &report); 1942 } 1943 1944 /* Stop processing this chunk. */ 1945 return 0; 1946 } 1947 1948 /* Report an Invalid Mandatory Parameter. */ 1949 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1950 struct sctp_chunk *chunk, 1951 struct sctp_chunk **errp) 1952 { 1953 /* Invalid Mandatory Parameter Error has no payload. */ 1954 1955 if (!*errp) 1956 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1957 1958 if (*errp) 1959 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1960 1961 /* Stop processing this chunk. */ 1962 return 0; 1963 } 1964 1965 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1966 struct sctp_paramhdr *param, 1967 const struct sctp_chunk *chunk, 1968 struct sctp_chunk **errp) 1969 { 1970 /* This is a fatal error. Any accumulated non-fatal errors are 1971 * not reported. 1972 */ 1973 if (*errp) 1974 sctp_chunk_free(*errp); 1975 1976 /* Create an error chunk and fill it in with our payload. */ 1977 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1978 1979 return 0; 1980 } 1981 1982 1983 /* Do not attempt to handle the HOST_NAME parm. However, do 1984 * send back an indicator to the peer. 1985 */ 1986 static int sctp_process_hn_param(const struct sctp_association *asoc, 1987 union sctp_params param, 1988 struct sctp_chunk *chunk, 1989 struct sctp_chunk **errp) 1990 { 1991 __u16 len = ntohs(param.p->length); 1992 1993 /* Processing of the HOST_NAME parameter will generate an 1994 * ABORT. If we've accumulated any non-fatal errors, they 1995 * would be unrecognized parameters and we should not include 1996 * them in the ABORT. 1997 */ 1998 if (*errp) 1999 sctp_chunk_free(*errp); 2000 2001 *errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_DNS_FAILED, 2002 param.v, len, 0); 2003 2004 /* Stop processing this chunk. */ 2005 return 0; 2006 } 2007 2008 static int sctp_verify_ext_param(struct net *net, 2009 const struct sctp_endpoint *ep, 2010 union sctp_params param) 2011 { 2012 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2013 int have_asconf = 0; 2014 int have_auth = 0; 2015 int i; 2016 2017 for (i = 0; i < num_ext; i++) { 2018 switch (param.ext->chunks[i]) { 2019 case SCTP_CID_AUTH: 2020 have_auth = 1; 2021 break; 2022 case SCTP_CID_ASCONF: 2023 case SCTP_CID_ASCONF_ACK: 2024 have_asconf = 1; 2025 break; 2026 } 2027 } 2028 2029 /* ADD-IP Security: The draft requires us to ABORT or ignore the 2030 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 2031 * only if ADD-IP is turned on and we are not backward-compatible 2032 * mode. 2033 */ 2034 if (net->sctp.addip_noauth) 2035 return 1; 2036 2037 if (ep->asconf_enable && !have_auth && have_asconf) 2038 return 0; 2039 2040 return 1; 2041 } 2042 2043 static void sctp_process_ext_param(struct sctp_association *asoc, 2044 union sctp_params param) 2045 { 2046 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2047 int i; 2048 2049 for (i = 0; i < num_ext; i++) { 2050 switch (param.ext->chunks[i]) { 2051 case SCTP_CID_RECONF: 2052 if (asoc->ep->reconf_enable) 2053 asoc->peer.reconf_capable = 1; 2054 break; 2055 case SCTP_CID_FWD_TSN: 2056 if (asoc->ep->prsctp_enable) 2057 asoc->peer.prsctp_capable = 1; 2058 break; 2059 case SCTP_CID_AUTH: 2060 /* if the peer reports AUTH, assume that he 2061 * supports AUTH. 2062 */ 2063 if (asoc->ep->auth_enable) 2064 asoc->peer.auth_capable = 1; 2065 break; 2066 case SCTP_CID_ASCONF: 2067 case SCTP_CID_ASCONF_ACK: 2068 if (asoc->ep->asconf_enable) 2069 asoc->peer.asconf_capable = 1; 2070 break; 2071 case SCTP_CID_I_DATA: 2072 if (asoc->ep->intl_enable) 2073 asoc->peer.intl_capable = 1; 2074 break; 2075 default: 2076 break; 2077 } 2078 } 2079 } 2080 2081 /* RFC 3.2.1 & the Implementers Guide 2.2. 2082 * 2083 * The Parameter Types are encoded such that the 2084 * highest-order two bits specify the action that must be 2085 * taken if the processing endpoint does not recognize the 2086 * Parameter Type. 2087 * 2088 * 00 - Stop processing this parameter; do not process any further 2089 * parameters within this chunk 2090 * 2091 * 01 - Stop processing this parameter, do not process any further 2092 * parameters within this chunk, and report the unrecognized 2093 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2094 * 2095 * 10 - Skip this parameter and continue processing. 2096 * 2097 * 11 - Skip this parameter and continue processing but 2098 * report the unrecognized parameter in an 2099 * 'Unrecognized Parameter' ERROR chunk. 2100 * 2101 * Return value: 2102 * SCTP_IERROR_NO_ERROR - continue with the chunk 2103 * SCTP_IERROR_ERROR - stop and report an error. 2104 * SCTP_IERROR_NOMEME - out of memory. 2105 */ 2106 static enum sctp_ierror sctp_process_unk_param( 2107 const struct sctp_association *asoc, 2108 union sctp_params param, 2109 struct sctp_chunk *chunk, 2110 struct sctp_chunk **errp) 2111 { 2112 int retval = SCTP_IERROR_NO_ERROR; 2113 2114 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2115 case SCTP_PARAM_ACTION_DISCARD: 2116 retval = SCTP_IERROR_ERROR; 2117 break; 2118 case SCTP_PARAM_ACTION_SKIP: 2119 break; 2120 case SCTP_PARAM_ACTION_DISCARD_ERR: 2121 retval = SCTP_IERROR_ERROR; 2122 fallthrough; 2123 case SCTP_PARAM_ACTION_SKIP_ERR: 2124 /* Make an ERROR chunk, preparing enough room for 2125 * returning multiple unknown parameters. 2126 */ 2127 if (!*errp) { 2128 *errp = sctp_make_op_error_limited(asoc, chunk); 2129 if (!*errp) { 2130 /* If there is no memory for generating the 2131 * ERROR report as specified, an ABORT will be 2132 * triggered to the peer and the association 2133 * won't be established. 2134 */ 2135 retval = SCTP_IERROR_NOMEM; 2136 break; 2137 } 2138 } 2139 2140 if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2141 ntohs(param.p->length))) 2142 sctp_addto_chunk(*errp, ntohs(param.p->length), 2143 param.v); 2144 break; 2145 default: 2146 break; 2147 } 2148 2149 return retval; 2150 } 2151 2152 /* Verify variable length parameters 2153 * Return values: 2154 * SCTP_IERROR_ABORT - trigger an ABORT 2155 * SCTP_IERROR_NOMEM - out of memory (abort) 2156 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2157 * SCTP_IERROR_NO_ERROR - continue with the chunk 2158 */ 2159 static enum sctp_ierror sctp_verify_param(struct net *net, 2160 const struct sctp_endpoint *ep, 2161 const struct sctp_association *asoc, 2162 union sctp_params param, 2163 enum sctp_cid cid, 2164 struct sctp_chunk *chunk, 2165 struct sctp_chunk **err_chunk) 2166 { 2167 struct sctp_hmac_algo_param *hmacs; 2168 int retval = SCTP_IERROR_NO_ERROR; 2169 __u16 n_elt, id = 0; 2170 int i; 2171 2172 /* FIXME - This routine is not looking at each parameter per the 2173 * chunk type, i.e., unrecognized parameters should be further 2174 * identified based on the chunk id. 2175 */ 2176 2177 switch (param.p->type) { 2178 case SCTP_PARAM_IPV4_ADDRESS: 2179 case SCTP_PARAM_IPV6_ADDRESS: 2180 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2181 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2182 case SCTP_PARAM_STATE_COOKIE: 2183 case SCTP_PARAM_HEARTBEAT_INFO: 2184 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2185 case SCTP_PARAM_ECN_CAPABLE: 2186 break; 2187 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2188 if (ntohs(param.p->length) != sizeof(*param.aind)) { 2189 sctp_process_inv_paramlength(asoc, param.p, 2190 chunk, err_chunk); 2191 retval = SCTP_IERROR_ABORT; 2192 } 2193 break; 2194 2195 case SCTP_PARAM_SUPPORTED_EXT: 2196 if (!sctp_verify_ext_param(net, ep, param)) 2197 return SCTP_IERROR_ABORT; 2198 break; 2199 2200 case SCTP_PARAM_SET_PRIMARY: 2201 if (!ep->asconf_enable) 2202 goto unhandled; 2203 2204 if (ntohs(param.p->length) < sizeof(struct sctp_addip_param) + 2205 sizeof(struct sctp_paramhdr)) { 2206 sctp_process_inv_paramlength(asoc, param.p, 2207 chunk, err_chunk); 2208 retval = SCTP_IERROR_ABORT; 2209 } 2210 break; 2211 2212 case SCTP_PARAM_HOST_NAME_ADDRESS: 2213 /* This param has been Deprecated, send ABORT. */ 2214 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2215 retval = SCTP_IERROR_ABORT; 2216 break; 2217 2218 case SCTP_PARAM_FWD_TSN_SUPPORT: 2219 if (ep->prsctp_enable) 2220 break; 2221 goto unhandled; 2222 2223 case SCTP_PARAM_RANDOM: 2224 if (!ep->auth_enable) 2225 goto unhandled; 2226 2227 /* SCTP-AUTH: Secion 6.1 2228 * If the random number is not 32 byte long the association 2229 * MUST be aborted. The ABORT chunk SHOULD contain the error 2230 * cause 'Protocol Violation'. 2231 */ 2232 if (SCTP_AUTH_RANDOM_LENGTH != ntohs(param.p->length) - 2233 sizeof(struct sctp_paramhdr)) { 2234 sctp_process_inv_paramlength(asoc, param.p, 2235 chunk, err_chunk); 2236 retval = SCTP_IERROR_ABORT; 2237 } 2238 break; 2239 2240 case SCTP_PARAM_CHUNKS: 2241 if (!ep->auth_enable) 2242 goto unhandled; 2243 2244 /* SCTP-AUTH: Section 3.2 2245 * The CHUNKS parameter MUST be included once in the INIT or 2246 * INIT-ACK chunk if the sender wants to receive authenticated 2247 * chunks. Its maximum length is 260 bytes. 2248 */ 2249 if (260 < ntohs(param.p->length)) { 2250 sctp_process_inv_paramlength(asoc, param.p, 2251 chunk, err_chunk); 2252 retval = SCTP_IERROR_ABORT; 2253 } 2254 break; 2255 2256 case SCTP_PARAM_HMAC_ALGO: 2257 if (!ep->auth_enable) 2258 goto unhandled; 2259 2260 hmacs = (struct sctp_hmac_algo_param *)param.p; 2261 n_elt = (ntohs(param.p->length) - 2262 sizeof(struct sctp_paramhdr)) >> 1; 2263 2264 /* SCTP-AUTH: Section 6.1 2265 * The HMAC algorithm based on SHA-1 MUST be supported and 2266 * included in the HMAC-ALGO parameter. 2267 */ 2268 for (i = 0; i < n_elt; i++) { 2269 id = ntohs(hmacs->hmac_ids[i]); 2270 2271 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2272 break; 2273 } 2274 2275 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2276 sctp_process_inv_paramlength(asoc, param.p, chunk, 2277 err_chunk); 2278 retval = SCTP_IERROR_ABORT; 2279 } 2280 break; 2281 unhandled: 2282 default: 2283 pr_debug("%s: unrecognized param:%d for chunk:%d\n", 2284 __func__, ntohs(param.p->type), cid); 2285 2286 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2287 break; 2288 } 2289 return retval; 2290 } 2291 2292 /* Verify the INIT packet before we process it. */ 2293 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 2294 const struct sctp_association *asoc, enum sctp_cid cid, 2295 struct sctp_init_chunk *peer_init, 2296 struct sctp_chunk *chunk, struct sctp_chunk **errp) 2297 { 2298 union sctp_params param; 2299 bool has_cookie = false; 2300 int result; 2301 2302 /* Check for missing mandatory parameters. Note: Initial TSN is 2303 * also mandatory, but is not checked here since the valid range 2304 * is 0..2**32-1. RFC4960, section 3.3.3. 2305 */ 2306 if (peer_init->init_hdr.num_outbound_streams == 0 || 2307 peer_init->init_hdr.num_inbound_streams == 0 || 2308 peer_init->init_hdr.init_tag == 0 || 2309 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) 2310 return sctp_process_inv_mandatory(asoc, chunk, errp); 2311 2312 sctp_walk_params(param, peer_init) { 2313 if (param.p->type == SCTP_PARAM_STATE_COOKIE) 2314 has_cookie = true; 2315 } 2316 2317 /* There is a possibility that a parameter length was bad and 2318 * in that case we would have stoped walking the parameters. 2319 * The current param.p would point at the bad one. 2320 * Current consensus on the mailing list is to generate a PROTOCOL 2321 * VIOLATION error. We build the ERROR chunk here and let the normal 2322 * error handling code build and send the packet. 2323 */ 2324 if (param.v != (void *)peer_init + 2325 SCTP_PAD4(ntohs(peer_init->chunk_hdr.length))) 2326 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2327 2328 /* The only missing mandatory param possible today is 2329 * the state cookie for an INIT-ACK chunk. 2330 */ 2331 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2332 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2333 chunk, errp); 2334 2335 /* Verify all the variable length parameters */ 2336 sctp_walk_params(param, peer_init) { 2337 result = sctp_verify_param(net, ep, asoc, param, cid, 2338 chunk, errp); 2339 switch (result) { 2340 case SCTP_IERROR_ABORT: 2341 case SCTP_IERROR_NOMEM: 2342 return 0; 2343 case SCTP_IERROR_ERROR: 2344 return 1; 2345 case SCTP_IERROR_NO_ERROR: 2346 default: 2347 break; 2348 } 2349 2350 } /* for (loop through all parameters) */ 2351 2352 return 1; 2353 } 2354 2355 /* Unpack the parameters in an INIT packet into an association. 2356 * Returns 0 on failure, else success. 2357 * FIXME: This is an association method. 2358 */ 2359 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2360 const union sctp_addr *peer_addr, 2361 struct sctp_init_chunk *peer_init, gfp_t gfp) 2362 { 2363 struct sctp_transport *transport; 2364 struct list_head *pos, *temp; 2365 union sctp_params param; 2366 union sctp_addr addr; 2367 struct sctp_af *af; 2368 int src_match = 0; 2369 2370 /* We must include the address that the INIT packet came from. 2371 * This is the only address that matters for an INIT packet. 2372 * When processing a COOKIE ECHO, we retrieve the from address 2373 * of the INIT from the cookie. 2374 */ 2375 2376 /* This implementation defaults to making the first transport 2377 * added as the primary transport. The source address seems to 2378 * be a better choice than any of the embedded addresses. 2379 */ 2380 asoc->encap_port = SCTP_INPUT_CB(chunk->skb)->encap_port; 2381 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2382 goto nomem; 2383 2384 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2385 src_match = 1; 2386 2387 /* Process the initialization parameters. */ 2388 sctp_walk_params(param, peer_init) { 2389 if (!src_match && 2390 (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2391 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2392 af = sctp_get_af_specific(param_type2af(param.p->type)); 2393 if (!af || !af->from_addr_param(&addr, param.addr, 2394 chunk->sctp_hdr->source, 0)) 2395 continue; 2396 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2397 src_match = 1; 2398 } 2399 2400 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2401 goto clean_up; 2402 } 2403 2404 /* source address of chunk may not match any valid address */ 2405 if (!src_match) 2406 goto clean_up; 2407 2408 /* AUTH: After processing the parameters, make sure that we 2409 * have all the required info to potentially do authentications. 2410 */ 2411 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2412 !asoc->peer.peer_hmacs)) 2413 asoc->peer.auth_capable = 0; 2414 2415 /* In a non-backward compatible mode, if the peer claims 2416 * support for ADD-IP but not AUTH, the ADD-IP spec states 2417 * that we MUST ABORT the association. Section 6. The section 2418 * also give us an option to silently ignore the packet, which 2419 * is what we'll do here. 2420 */ 2421 if (!asoc->base.net->sctp.addip_noauth && 2422 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2423 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2424 SCTP_PARAM_DEL_IP | 2425 SCTP_PARAM_SET_PRIMARY); 2426 asoc->peer.asconf_capable = 0; 2427 goto clean_up; 2428 } 2429 2430 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2431 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2432 transport = list_entry(pos, struct sctp_transport, transports); 2433 if (transport->state == SCTP_UNKNOWN) { 2434 sctp_assoc_rm_peer(asoc, transport); 2435 } 2436 } 2437 2438 /* The fixed INIT headers are always in network byte 2439 * order. 2440 */ 2441 asoc->peer.i.init_tag = 2442 ntohl(peer_init->init_hdr.init_tag); 2443 asoc->peer.i.a_rwnd = 2444 ntohl(peer_init->init_hdr.a_rwnd); 2445 asoc->peer.i.num_outbound_streams = 2446 ntohs(peer_init->init_hdr.num_outbound_streams); 2447 asoc->peer.i.num_inbound_streams = 2448 ntohs(peer_init->init_hdr.num_inbound_streams); 2449 asoc->peer.i.initial_tsn = 2450 ntohl(peer_init->init_hdr.initial_tsn); 2451 2452 asoc->strreset_inseq = asoc->peer.i.initial_tsn; 2453 2454 /* Apply the upper bounds for output streams based on peer's 2455 * number of inbound streams. 2456 */ 2457 if (asoc->c.sinit_num_ostreams > 2458 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2459 asoc->c.sinit_num_ostreams = 2460 ntohs(peer_init->init_hdr.num_inbound_streams); 2461 } 2462 2463 if (asoc->c.sinit_max_instreams > 2464 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2465 asoc->c.sinit_max_instreams = 2466 ntohs(peer_init->init_hdr.num_outbound_streams); 2467 } 2468 2469 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2470 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2471 2472 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2473 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2474 2475 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2476 * high (for example, implementations MAY use the size of the receiver 2477 * advertised window). 2478 */ 2479 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2480 transports) { 2481 transport->ssthresh = asoc->peer.i.a_rwnd; 2482 } 2483 2484 /* Set up the TSN tracking pieces. */ 2485 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2486 asoc->peer.i.initial_tsn, gfp)) 2487 goto clean_up; 2488 2489 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2490 * 2491 * The stream sequence number in all the streams shall start 2492 * from 0 when the association is established. Also, when the 2493 * stream sequence number reaches the value 65535 the next 2494 * stream sequence number shall be set to 0. 2495 */ 2496 2497 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams, 2498 asoc->c.sinit_max_instreams, gfp)) 2499 goto clean_up; 2500 2501 /* Update frag_point when stream_interleave may get changed. */ 2502 sctp_assoc_update_frag_point(asoc); 2503 2504 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp)) 2505 goto clean_up; 2506 2507 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2508 * 2509 * When an endpoint has an ASCONF signaled change to be sent to the 2510 * remote endpoint it should do the following: 2511 * ... 2512 * A2) A serial number should be assigned to the Chunk. The serial 2513 * number should be a monotonically increasing number. All serial 2514 * numbers are defined to be initialized at the start of the 2515 * association to the same value as the Initial TSN. 2516 */ 2517 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2518 return 1; 2519 2520 clean_up: 2521 /* Release the transport structures. */ 2522 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2523 transport = list_entry(pos, struct sctp_transport, transports); 2524 if (transport->state != SCTP_ACTIVE) 2525 sctp_assoc_rm_peer(asoc, transport); 2526 } 2527 2528 nomem: 2529 return 0; 2530 } 2531 2532 2533 /* Update asoc with the option described in param. 2534 * 2535 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2536 * 2537 * asoc is the association to update. 2538 * param is the variable length parameter to use for update. 2539 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2540 * If the current packet is an INIT we want to minimize the amount of 2541 * work we do. In particular, we should not build transport 2542 * structures for the addresses. 2543 */ 2544 static int sctp_process_param(struct sctp_association *asoc, 2545 union sctp_params param, 2546 const union sctp_addr *peer_addr, 2547 gfp_t gfp) 2548 { 2549 struct sctp_endpoint *ep = asoc->ep; 2550 union sctp_addr_param *addr_param; 2551 struct net *net = asoc->base.net; 2552 struct sctp_transport *t; 2553 enum sctp_scope scope; 2554 union sctp_addr addr; 2555 struct sctp_af *af; 2556 int retval = 1, i; 2557 u32 stale; 2558 __u16 sat; 2559 2560 /* We maintain all INIT parameters in network byte order all the 2561 * time. This allows us to not worry about whether the parameters 2562 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2563 */ 2564 switch (param.p->type) { 2565 case SCTP_PARAM_IPV6_ADDRESS: 2566 case SCTP_PARAM_IPV4_ADDRESS: 2567 af = sctp_get_af_specific(param_type2af(param.p->type)); 2568 if (!af || !af->from_addr_param(&addr, param.addr, 2569 htons(asoc->peer.port), 0) || 2570 !af->addr_valid(&addr, sctp_sk(asoc->base.sk), NULL)) 2571 break; 2572 scope = sctp_scope(peer_addr); 2573 if (sctp_in_scope(net, &addr, scope)) 2574 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2575 return 0; 2576 break; 2577 2578 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2579 if (!net->sctp.cookie_preserve_enable) 2580 break; 2581 2582 stale = ntohl(param.life->lifespan_increment); 2583 2584 /* Suggested Cookie Life span increment's unit is msec, 2585 * (1/1000sec). 2586 */ 2587 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale); 2588 break; 2589 2590 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2591 /* Turn off the default values first so we'll know which 2592 * ones are really set by the peer. 2593 */ 2594 asoc->peer.ipv4_address = 0; 2595 asoc->peer.ipv6_address = 0; 2596 2597 /* Assume that peer supports the address family 2598 * by which it sends a packet. 2599 */ 2600 if (peer_addr->sa.sa_family == AF_INET6) 2601 asoc->peer.ipv6_address = 1; 2602 else if (peer_addr->sa.sa_family == AF_INET) 2603 asoc->peer.ipv4_address = 1; 2604 2605 /* Cycle through address types; avoid divide by 0. */ 2606 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2607 if (sat) 2608 sat /= sizeof(__u16); 2609 2610 for (i = 0; i < sat; ++i) { 2611 switch (param.sat->types[i]) { 2612 case SCTP_PARAM_IPV4_ADDRESS: 2613 asoc->peer.ipv4_address = 1; 2614 break; 2615 2616 case SCTP_PARAM_IPV6_ADDRESS: 2617 if (PF_INET6 == asoc->base.sk->sk_family) 2618 asoc->peer.ipv6_address = 1; 2619 break; 2620 2621 default: /* Just ignore anything else. */ 2622 break; 2623 } 2624 } 2625 break; 2626 2627 case SCTP_PARAM_STATE_COOKIE: 2628 asoc->peer.cookie_len = 2629 ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2630 kfree(asoc->peer.cookie); 2631 asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp); 2632 if (!asoc->peer.cookie) 2633 retval = 0; 2634 break; 2635 2636 case SCTP_PARAM_HEARTBEAT_INFO: 2637 /* Would be odd to receive, but it causes no problems. */ 2638 break; 2639 2640 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2641 /* Rejected during verify stage. */ 2642 break; 2643 2644 case SCTP_PARAM_ECN_CAPABLE: 2645 if (asoc->ep->ecn_enable) { 2646 asoc->peer.ecn_capable = 1; 2647 break; 2648 } 2649 /* Fall Through */ 2650 goto fall_through; 2651 2652 2653 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2654 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2655 break; 2656 2657 case SCTP_PARAM_SET_PRIMARY: 2658 if (!ep->asconf_enable) 2659 goto fall_through; 2660 2661 addr_param = param.v + sizeof(struct sctp_addip_param); 2662 if (ntohs(addr_param->p.length) > 2663 ntohs(param.p->length) - sizeof(struct sctp_addip_param)) 2664 break; 2665 2666 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 2667 if (!af) 2668 break; 2669 2670 if (!af->from_addr_param(&addr, addr_param, 2671 htons(asoc->peer.port), 0)) 2672 break; 2673 2674 if (!af->addr_valid(&addr, NULL, NULL)) 2675 break; 2676 2677 t = sctp_assoc_lookup_paddr(asoc, &addr); 2678 if (!t) 2679 break; 2680 2681 sctp_assoc_set_primary(asoc, t); 2682 break; 2683 2684 case SCTP_PARAM_SUPPORTED_EXT: 2685 sctp_process_ext_param(asoc, param); 2686 break; 2687 2688 case SCTP_PARAM_FWD_TSN_SUPPORT: 2689 if (asoc->ep->prsctp_enable) { 2690 asoc->peer.prsctp_capable = 1; 2691 break; 2692 } 2693 /* Fall Through */ 2694 goto fall_through; 2695 2696 case SCTP_PARAM_RANDOM: 2697 if (!ep->auth_enable) 2698 goto fall_through; 2699 2700 /* Save peer's random parameter */ 2701 kfree(asoc->peer.peer_random); 2702 asoc->peer.peer_random = kmemdup(param.p, 2703 ntohs(param.p->length), gfp); 2704 if (!asoc->peer.peer_random) { 2705 retval = 0; 2706 break; 2707 } 2708 break; 2709 2710 case SCTP_PARAM_HMAC_ALGO: 2711 if (!ep->auth_enable) 2712 goto fall_through; 2713 2714 /* Save peer's HMAC list */ 2715 kfree(asoc->peer.peer_hmacs); 2716 asoc->peer.peer_hmacs = kmemdup(param.p, 2717 ntohs(param.p->length), gfp); 2718 if (!asoc->peer.peer_hmacs) { 2719 retval = 0; 2720 break; 2721 } 2722 2723 /* Set the default HMAC the peer requested*/ 2724 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2725 break; 2726 2727 case SCTP_PARAM_CHUNKS: 2728 if (!ep->auth_enable) 2729 goto fall_through; 2730 2731 kfree(asoc->peer.peer_chunks); 2732 asoc->peer.peer_chunks = kmemdup(param.p, 2733 ntohs(param.p->length), gfp); 2734 if (!asoc->peer.peer_chunks) 2735 retval = 0; 2736 break; 2737 fall_through: 2738 default: 2739 /* Any unrecognized parameters should have been caught 2740 * and handled by sctp_verify_param() which should be 2741 * called prior to this routine. Simply log the error 2742 * here. 2743 */ 2744 pr_debug("%s: ignoring param:%d for association:%p.\n", 2745 __func__, ntohs(param.p->type), asoc); 2746 break; 2747 } 2748 2749 return retval; 2750 } 2751 2752 /* Select a new verification tag. */ 2753 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2754 { 2755 /* I believe that this random number generator complies with RFC1750. 2756 * A tag of 0 is reserved for special cases (e.g. INIT). 2757 */ 2758 __u32 x; 2759 2760 do { 2761 x = get_random_u32(); 2762 } while (x == 0); 2763 2764 return x; 2765 } 2766 2767 /* Select an initial TSN to send during startup. */ 2768 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2769 { 2770 __u32 retval; 2771 2772 retval = get_random_u32(); 2773 return retval; 2774 } 2775 2776 /* 2777 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2778 * 0 1 2 3 2779 * 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 2780 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2781 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2782 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2783 * | Serial Number | 2784 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2785 * | Address Parameter | 2786 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2787 * | ASCONF Parameter #1 | 2788 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2789 * \ \ 2790 * / .... / 2791 * \ \ 2792 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2793 * | ASCONF Parameter #N | 2794 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2795 * 2796 * Address Parameter and other parameter will not be wrapped in this function 2797 */ 2798 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2799 union sctp_addr *addr, 2800 int vparam_len) 2801 { 2802 struct sctp_addiphdr asconf; 2803 struct sctp_chunk *retval; 2804 int length = sizeof(asconf) + vparam_len; 2805 union sctp_addr_param addrparam; 2806 int addrlen; 2807 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2808 2809 addrlen = af->to_addr_param(addr, &addrparam); 2810 if (!addrlen) 2811 return NULL; 2812 length += addrlen; 2813 2814 /* Create the chunk. */ 2815 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length, 2816 GFP_ATOMIC); 2817 if (!retval) 2818 return NULL; 2819 2820 asconf.serial = htonl(asoc->addip_serial++); 2821 2822 retval->subh.addip_hdr = 2823 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2824 retval->param_hdr.v = 2825 sctp_addto_chunk(retval, addrlen, &addrparam); 2826 2827 return retval; 2828 } 2829 2830 /* ADDIP 2831 * 3.2.1 Add IP Address 2832 * 0 1 2 3 2833 * 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 2834 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2835 * | Type = 0xC001 | Length = Variable | 2836 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2837 * | ASCONF-Request Correlation ID | 2838 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2839 * | Address Parameter | 2840 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2841 * 2842 * 3.2.2 Delete IP Address 2843 * 0 1 2 3 2844 * 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 2845 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2846 * | Type = 0xC002 | Length = Variable | 2847 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2848 * | ASCONF-Request Correlation ID | 2849 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2850 * | Address Parameter | 2851 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2852 * 2853 */ 2854 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2855 union sctp_addr *laddr, 2856 struct sockaddr *addrs, 2857 int addrcnt, __be16 flags) 2858 { 2859 union sctp_addr_param addr_param; 2860 struct sctp_addip_param param; 2861 int paramlen = sizeof(param); 2862 struct sctp_chunk *retval; 2863 int addr_param_len = 0; 2864 union sctp_addr *addr; 2865 int totallen = 0, i; 2866 int del_pickup = 0; 2867 struct sctp_af *af; 2868 void *addr_buf; 2869 2870 /* Get total length of all the address parameters. */ 2871 addr_buf = addrs; 2872 for (i = 0; i < addrcnt; i++) { 2873 addr = addr_buf; 2874 af = sctp_get_af_specific(addr->v4.sin_family); 2875 addr_param_len = af->to_addr_param(addr, &addr_param); 2876 2877 totallen += paramlen; 2878 totallen += addr_param_len; 2879 2880 addr_buf += af->sockaddr_len; 2881 if (asoc->asconf_addr_del_pending && !del_pickup) { 2882 /* reuse the parameter length from the same scope one */ 2883 totallen += paramlen; 2884 totallen += addr_param_len; 2885 del_pickup = 1; 2886 2887 pr_debug("%s: picked same-scope del_pending addr, " 2888 "totallen for all addresses is %d\n", 2889 __func__, totallen); 2890 } 2891 } 2892 2893 /* Create an asconf chunk with the required length. */ 2894 retval = sctp_make_asconf(asoc, laddr, totallen); 2895 if (!retval) 2896 return NULL; 2897 2898 /* Add the address parameters to the asconf chunk. */ 2899 addr_buf = addrs; 2900 for (i = 0; i < addrcnt; i++) { 2901 addr = addr_buf; 2902 af = sctp_get_af_specific(addr->v4.sin_family); 2903 addr_param_len = af->to_addr_param(addr, &addr_param); 2904 param.param_hdr.type = flags; 2905 param.param_hdr.length = htons(paramlen + addr_param_len); 2906 param.crr_id = htonl(i); 2907 2908 sctp_addto_chunk(retval, paramlen, ¶m); 2909 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2910 2911 addr_buf += af->sockaddr_len; 2912 } 2913 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2914 addr = asoc->asconf_addr_del_pending; 2915 af = sctp_get_af_specific(addr->v4.sin_family); 2916 addr_param_len = af->to_addr_param(addr, &addr_param); 2917 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2918 param.param_hdr.length = htons(paramlen + addr_param_len); 2919 param.crr_id = htonl(i); 2920 2921 sctp_addto_chunk(retval, paramlen, ¶m); 2922 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2923 } 2924 return retval; 2925 } 2926 2927 /* ADDIP 2928 * 3.2.4 Set Primary IP Address 2929 * 0 1 2 3 2930 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2931 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2932 * | Type =0xC004 | Length = Variable | 2933 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2934 * | ASCONF-Request Correlation ID | 2935 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2936 * | Address Parameter | 2937 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2938 * 2939 * Create an ASCONF chunk with Set Primary IP address parameter. 2940 */ 2941 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2942 union sctp_addr *addr) 2943 { 2944 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2945 union sctp_addr_param addrparam; 2946 struct sctp_addip_param param; 2947 struct sctp_chunk *retval; 2948 int len = sizeof(param); 2949 int addrlen; 2950 2951 addrlen = af->to_addr_param(addr, &addrparam); 2952 if (!addrlen) 2953 return NULL; 2954 len += addrlen; 2955 2956 /* Create the chunk and make asconf header. */ 2957 retval = sctp_make_asconf(asoc, addr, len); 2958 if (!retval) 2959 return NULL; 2960 2961 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2962 param.param_hdr.length = htons(len); 2963 param.crr_id = 0; 2964 2965 sctp_addto_chunk(retval, sizeof(param), ¶m); 2966 sctp_addto_chunk(retval, addrlen, &addrparam); 2967 2968 return retval; 2969 } 2970 2971 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2972 * 0 1 2 3 2973 * 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 2974 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2975 * | Type = 0x80 | Chunk Flags | Chunk Length | 2976 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2977 * | Serial Number | 2978 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2979 * | ASCONF Parameter Response#1 | 2980 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2981 * \ \ 2982 * / .... / 2983 * \ \ 2984 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2985 * | ASCONF Parameter Response#N | 2986 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2987 * 2988 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2989 */ 2990 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2991 __u32 serial, int vparam_len) 2992 { 2993 struct sctp_addiphdr asconf; 2994 struct sctp_chunk *retval; 2995 int length = sizeof(asconf) + vparam_len; 2996 2997 /* Create the chunk. */ 2998 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length, 2999 GFP_ATOMIC); 3000 if (!retval) 3001 return NULL; 3002 3003 asconf.serial = htonl(serial); 3004 3005 retval->subh.addip_hdr = 3006 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 3007 3008 return retval; 3009 } 3010 3011 /* Add response parameters to an ASCONF_ACK chunk. */ 3012 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 3013 __be16 err_code, 3014 struct sctp_addip_param *asconf_param) 3015 { 3016 struct sctp_addip_param ack_param; 3017 struct sctp_errhdr err_param; 3018 int asconf_param_len = 0; 3019 int err_param_len = 0; 3020 __be16 response_type; 3021 3022 if (SCTP_ERROR_NO_ERROR == err_code) { 3023 response_type = SCTP_PARAM_SUCCESS_REPORT; 3024 } else { 3025 response_type = SCTP_PARAM_ERR_CAUSE; 3026 err_param_len = sizeof(err_param); 3027 if (asconf_param) 3028 asconf_param_len = 3029 ntohs(asconf_param->param_hdr.length); 3030 } 3031 3032 /* Add Success Indication or Error Cause Indication parameter. */ 3033 ack_param.param_hdr.type = response_type; 3034 ack_param.param_hdr.length = htons(sizeof(ack_param) + 3035 err_param_len + 3036 asconf_param_len); 3037 ack_param.crr_id = crr_id; 3038 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 3039 3040 if (SCTP_ERROR_NO_ERROR == err_code) 3041 return; 3042 3043 /* Add Error Cause parameter. */ 3044 err_param.cause = err_code; 3045 err_param.length = htons(err_param_len + asconf_param_len); 3046 sctp_addto_chunk(chunk, err_param_len, &err_param); 3047 3048 /* Add the failed TLV copied from ASCONF chunk. */ 3049 if (asconf_param) 3050 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 3051 } 3052 3053 /* Process a asconf parameter. */ 3054 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 3055 struct sctp_chunk *asconf, 3056 struct sctp_addip_param *asconf_param) 3057 { 3058 union sctp_addr_param *addr_param; 3059 struct sctp_transport *peer; 3060 union sctp_addr addr; 3061 struct sctp_af *af; 3062 3063 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 3064 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 3065 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 3066 return SCTP_ERROR_UNKNOWN_PARAM; 3067 3068 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3069 if (ntohs(addr_param->p.length) > 3070 ntohs(asconf_param->param_hdr.length) - sizeof(*asconf_param)) 3071 return SCTP_ERROR_PROTO_VIOLATION; 3072 3073 switch (addr_param->p.type) { 3074 case SCTP_PARAM_IPV6_ADDRESS: 3075 if (!asoc->peer.ipv6_address) 3076 return SCTP_ERROR_DNS_FAILED; 3077 break; 3078 case SCTP_PARAM_IPV4_ADDRESS: 3079 if (!asoc->peer.ipv4_address) 3080 return SCTP_ERROR_DNS_FAILED; 3081 break; 3082 default: 3083 return SCTP_ERROR_DNS_FAILED; 3084 } 3085 3086 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3087 if (unlikely(!af)) 3088 return SCTP_ERROR_DNS_FAILED; 3089 3090 if (!af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0)) 3091 return SCTP_ERROR_DNS_FAILED; 3092 3093 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3094 * or multicast address. 3095 * (note: wildcard is permitted and requires special handling so 3096 * make sure we check for that) 3097 */ 3098 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3099 return SCTP_ERROR_DNS_FAILED; 3100 3101 switch (asconf_param->param_hdr.type) { 3102 case SCTP_PARAM_ADD_IP: 3103 /* Section 4.2.1: 3104 * If the address 0.0.0.0 or ::0 is provided, the source 3105 * address of the packet MUST be added. 3106 */ 3107 if (af->is_any(&addr)) 3108 memcpy(&addr, &asconf->source, sizeof(addr)); 3109 3110 if (security_sctp_bind_connect(asoc->ep->base.sk, 3111 SCTP_PARAM_ADD_IP, 3112 (struct sockaddr *)&addr, 3113 af->sockaddr_len)) 3114 return SCTP_ERROR_REQ_REFUSED; 3115 3116 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3117 * request and does not have the local resources to add this 3118 * new address to the association, it MUST return an Error 3119 * Cause TLV set to the new error code 'Operation Refused 3120 * Due to Resource Shortage'. 3121 */ 3122 3123 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3124 if (!peer) 3125 return SCTP_ERROR_RSRC_LOW; 3126 3127 /* Start the heartbeat timer. */ 3128 sctp_transport_reset_hb_timer(peer); 3129 asoc->new_transport = peer; 3130 break; 3131 case SCTP_PARAM_DEL_IP: 3132 /* ADDIP 4.3 D7) If a request is received to delete the 3133 * last remaining IP address of a peer endpoint, the receiver 3134 * MUST send an Error Cause TLV with the error cause set to the 3135 * new error code 'Request to Delete Last Remaining IP Address'. 3136 */ 3137 if (asoc->peer.transport_count == 1) 3138 return SCTP_ERROR_DEL_LAST_IP; 3139 3140 /* ADDIP 4.3 D8) If a request is received to delete an IP 3141 * address which is also the source address of the IP packet 3142 * which contained the ASCONF chunk, the receiver MUST reject 3143 * this request. To reject the request the receiver MUST send 3144 * an Error Cause TLV set to the new error code 'Request to 3145 * Delete Source IP Address' 3146 */ 3147 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3148 return SCTP_ERROR_DEL_SRC_IP; 3149 3150 /* Section 4.2.2 3151 * If the address 0.0.0.0 or ::0 is provided, all 3152 * addresses of the peer except the source address of the 3153 * packet MUST be deleted. 3154 */ 3155 if (af->is_any(&addr)) { 3156 sctp_assoc_set_primary(asoc, asconf->transport); 3157 sctp_assoc_del_nonprimary_peers(asoc, 3158 asconf->transport); 3159 return SCTP_ERROR_NO_ERROR; 3160 } 3161 3162 /* If the address is not part of the association, the 3163 * ASCONF-ACK with Error Cause Indication Parameter 3164 * which including cause of Unresolvable Address should 3165 * be sent. 3166 */ 3167 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3168 if (!peer) 3169 return SCTP_ERROR_DNS_FAILED; 3170 3171 /* Don't free asconf->transport; a later wildcard DEL-IP 3172 * parameter reuses it. 3173 */ 3174 if (peer == asconf->transport) 3175 return SCTP_ERROR_REQ_REFUSED; 3176 3177 sctp_assoc_rm_peer(asoc, peer); 3178 break; 3179 case SCTP_PARAM_SET_PRIMARY: 3180 /* ADDIP Section 4.2.4 3181 * If the address 0.0.0.0 or ::0 is provided, the receiver 3182 * MAY mark the source address of the packet as its 3183 * primary. 3184 */ 3185 if (af->is_any(&addr)) 3186 memcpy(&addr, sctp_source(asconf), sizeof(addr)); 3187 3188 if (security_sctp_bind_connect(asoc->ep->base.sk, 3189 SCTP_PARAM_SET_PRIMARY, 3190 (struct sockaddr *)&addr, 3191 af->sockaddr_len)) 3192 return SCTP_ERROR_REQ_REFUSED; 3193 3194 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3195 if (!peer) 3196 return SCTP_ERROR_DNS_FAILED; 3197 3198 sctp_assoc_set_primary(asoc, peer); 3199 break; 3200 } 3201 3202 return SCTP_ERROR_NO_ERROR; 3203 } 3204 3205 /* Verify the ASCONF packet before we process it. */ 3206 bool sctp_verify_asconf(const struct sctp_association *asoc, 3207 struct sctp_chunk *chunk, bool addr_param_needed, 3208 struct sctp_paramhdr **errp) 3209 { 3210 struct sctp_addip_chunk *addip; 3211 bool addr_param_seen = false; 3212 union sctp_params param; 3213 3214 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr; 3215 sctp_walk_params(param, addip) { 3216 size_t length = ntohs(param.p->length); 3217 3218 *errp = param.p; 3219 switch (param.p->type) { 3220 case SCTP_PARAM_ERR_CAUSE: 3221 if (length < sizeof(struct sctp_addip_param) + 3222 sizeof(struct sctp_errhdr)) 3223 return false; 3224 break; 3225 case SCTP_PARAM_IPV4_ADDRESS: 3226 if (length != sizeof(struct sctp_ipv4addr_param)) 3227 return false; 3228 /* ensure there is only one addr param and it's in the 3229 * beginning of addip_hdr params, or we reject it. 3230 */ 3231 if (param.v != (addip + 1)) 3232 return false; 3233 addr_param_seen = true; 3234 break; 3235 case SCTP_PARAM_IPV6_ADDRESS: 3236 if (length != sizeof(struct sctp_ipv6addr_param)) 3237 return false; 3238 if (param.v != (addip + 1)) 3239 return false; 3240 addr_param_seen = true; 3241 break; 3242 case SCTP_PARAM_ADD_IP: 3243 case SCTP_PARAM_DEL_IP: 3244 case SCTP_PARAM_SET_PRIMARY: 3245 /* In ASCONF chunks, these need to be first. */ 3246 if (addr_param_needed && !addr_param_seen) 3247 return false; 3248 length = ntohs(param.addip->param_hdr.length); 3249 if (length < sizeof(struct sctp_addip_param) + 3250 sizeof(**errp)) 3251 return false; 3252 break; 3253 case SCTP_PARAM_SUCCESS_REPORT: 3254 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3255 if (length != sizeof(struct sctp_addip_param)) 3256 return false; 3257 break; 3258 default: 3259 /* This is unknown to us, reject! */ 3260 return false; 3261 } 3262 } 3263 3264 /* Remaining sanity checks. */ 3265 if (addr_param_needed && !addr_param_seen) 3266 return false; 3267 if (!addr_param_needed && addr_param_seen) 3268 return false; 3269 if (param.v != chunk->chunk_end) 3270 return false; 3271 3272 return true; 3273 } 3274 3275 /* Process an incoming ASCONF chunk with the next expected serial no. and 3276 * return an ASCONF_ACK chunk to be sent in response. 3277 */ 3278 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3279 struct sctp_chunk *asconf) 3280 { 3281 union sctp_addr_param *addr_param; 3282 struct sctp_addip_chunk *addip; 3283 struct sctp_chunk *asconf_ack; 3284 bool all_param_pass = true; 3285 struct sctp_addiphdr *hdr; 3286 int length = 0, chunk_len; 3287 union sctp_params param; 3288 __be16 err_code; 3289 __u32 serial; 3290 3291 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr; 3292 chunk_len = ntohs(asconf->chunk_hdr->length) - 3293 sizeof(struct sctp_chunkhdr); 3294 hdr = (struct sctp_addiphdr *)asconf->skb->data; 3295 serial = ntohl(hdr->serial); 3296 3297 /* Skip the addiphdr and store a pointer to address parameter. */ 3298 length = sizeof(*hdr); 3299 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3300 chunk_len -= length; 3301 3302 /* Skip the address parameter and store a pointer to the first 3303 * asconf parameter. 3304 */ 3305 length = ntohs(addr_param->p.length); 3306 chunk_len -= length; 3307 3308 /* create an ASCONF_ACK chunk. 3309 * Based on the definitions of parameters, we know that the size of 3310 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3311 * parameters. 3312 */ 3313 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3314 if (!asconf_ack) 3315 goto done; 3316 3317 /* Process the TLVs contained within the ASCONF chunk. */ 3318 sctp_walk_params(param, addip) { 3319 /* Skip preceding address parameters. */ 3320 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 3321 param.p->type == SCTP_PARAM_IPV6_ADDRESS) 3322 continue; 3323 3324 err_code = sctp_process_asconf_param(asoc, asconf, 3325 param.addip); 3326 /* ADDIP 4.1 A7) 3327 * If an error response is received for a TLV parameter, 3328 * all TLVs with no response before the failed TLV are 3329 * considered successful if not reported. All TLVs after 3330 * the failed response are considered unsuccessful unless 3331 * a specific success indication is present for the parameter. 3332 */ 3333 if (err_code != SCTP_ERROR_NO_ERROR) 3334 all_param_pass = false; 3335 if (!all_param_pass) 3336 sctp_add_asconf_response(asconf_ack, param.addip->crr_id, 3337 err_code, param.addip); 3338 3339 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3340 * an IP address sends an 'Out of Resource' in its response, it 3341 * MUST also fail any subsequent add or delete requests bundled 3342 * in the ASCONF. 3343 */ 3344 if (err_code == SCTP_ERROR_RSRC_LOW) 3345 goto done; 3346 } 3347 done: 3348 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3349 * after freeing the reference to old asconf ack if any. 3350 */ 3351 if (asconf_ack) { 3352 asoc->peer.addip_serial++; 3353 sctp_chunk_hold(asconf_ack); 3354 list_add_tail(&asconf_ack->transmitted_list, 3355 &asoc->asconf_ack_list); 3356 } 3357 3358 return asconf_ack; 3359 } 3360 3361 /* Process a asconf parameter that is successfully acked. */ 3362 static void sctp_asconf_param_success(struct sctp_association *asoc, 3363 struct sctp_addip_param *asconf_param) 3364 { 3365 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3366 union sctp_addr_param *addr_param; 3367 struct sctp_sockaddr_entry *saddr; 3368 struct sctp_transport *transport; 3369 union sctp_addr addr; 3370 struct sctp_af *af; 3371 3372 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3373 3374 /* We have checked the packet before, so we do not check again. */ 3375 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3376 if (!af->from_addr_param(&addr, addr_param, htons(bp->port), 0)) 3377 return; 3378 3379 switch (asconf_param->param_hdr.type) { 3380 case SCTP_PARAM_ADD_IP: 3381 /* This is always done in BH context with a socket lock 3382 * held, so the list can not change. 3383 */ 3384 local_bh_disable(); 3385 list_for_each_entry(saddr, &bp->address_list, list) { 3386 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3387 saddr->state = SCTP_ADDR_SRC; 3388 } 3389 local_bh_enable(); 3390 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3391 transports) { 3392 sctp_transport_dst_release(transport); 3393 } 3394 break; 3395 case SCTP_PARAM_DEL_IP: 3396 local_bh_disable(); 3397 sctp_del_bind_addr(bp, &addr); 3398 if (asoc->asconf_addr_del_pending != NULL && 3399 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3400 kfree(asoc->asconf_addr_del_pending); 3401 asoc->asconf_addr_del_pending = NULL; 3402 } 3403 local_bh_enable(); 3404 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3405 transports) { 3406 sctp_transport_dst_release(transport); 3407 } 3408 break; 3409 default: 3410 break; 3411 } 3412 } 3413 3414 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3415 * for the given asconf parameter. If there is no response for this parameter, 3416 * return the error code based on the third argument 'no_err'. 3417 * ADDIP 4.1 3418 * A7) If an error response is received for a TLV parameter, all TLVs with no 3419 * response before the failed TLV are considered successful if not reported. 3420 * All TLVs after the failed response are considered unsuccessful unless a 3421 * specific success indication is present for the parameter. 3422 */ 3423 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3424 struct sctp_addip_param *asconf_param, 3425 int no_err) 3426 { 3427 struct sctp_addip_param *asconf_ack_param; 3428 struct sctp_errhdr *err_param; 3429 int asconf_ack_len; 3430 __be16 err_code; 3431 int length; 3432 3433 if (no_err) 3434 err_code = SCTP_ERROR_NO_ERROR; 3435 else 3436 err_code = SCTP_ERROR_REQ_REFUSED; 3437 3438 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3439 sizeof(struct sctp_chunkhdr); 3440 3441 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3442 * the first asconf_ack parameter. 3443 */ 3444 length = sizeof(struct sctp_addiphdr); 3445 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data + 3446 length); 3447 asconf_ack_len -= length; 3448 3449 while (asconf_ack_len > 0) { 3450 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3451 switch (asconf_ack_param->param_hdr.type) { 3452 case SCTP_PARAM_SUCCESS_REPORT: 3453 return SCTP_ERROR_NO_ERROR; 3454 case SCTP_PARAM_ERR_CAUSE: 3455 length = sizeof(*asconf_ack_param); 3456 err_param = (void *)asconf_ack_param + length; 3457 return err_param->cause; 3458 default: 3459 return SCTP_ERROR_INV_PARAM; 3460 } 3461 } 3462 3463 length = ntohs(asconf_ack_param->param_hdr.length); 3464 asconf_ack_param = (void *)asconf_ack_param + SCTP_PAD4(length); 3465 asconf_ack_len -= SCTP_PAD4(length); 3466 } 3467 3468 return err_code; 3469 } 3470 3471 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3472 int sctp_process_asconf_ack(struct sctp_association *asoc, 3473 struct sctp_chunk *asconf_ack) 3474 { 3475 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3476 struct sctp_addip_param *asconf_param; 3477 __be16 err_code = SCTP_ERROR_NO_ERROR; 3478 union sctp_addr_param *addr_param; 3479 int asconf_len = asconf->skb->len; 3480 int all_param_pass = 0; 3481 int length = 0; 3482 int no_err = 1; 3483 int retval = 0; 3484 3485 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3486 * a pointer to address parameter. 3487 */ 3488 length = sizeof(struct sctp_addip_chunk); 3489 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3490 asconf_len -= length; 3491 3492 /* Skip the address parameter in the last asconf sent and store a 3493 * pointer to the first asconf parameter. 3494 */ 3495 length = ntohs(addr_param->p.length); 3496 asconf_param = (void *)addr_param + length; 3497 asconf_len -= length; 3498 3499 /* ADDIP 4.1 3500 * A8) If there is no response(s) to specific TLV parameter(s), and no 3501 * failures are indicated, then all request(s) are considered 3502 * successful. 3503 */ 3504 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr)) 3505 all_param_pass = 1; 3506 3507 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3508 while (asconf_len > 0) { 3509 if (all_param_pass) 3510 err_code = SCTP_ERROR_NO_ERROR; 3511 else { 3512 err_code = sctp_get_asconf_response(asconf_ack, 3513 asconf_param, 3514 no_err); 3515 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3516 no_err = 0; 3517 } 3518 3519 switch (err_code) { 3520 case SCTP_ERROR_NO_ERROR: 3521 sctp_asconf_param_success(asoc, asconf_param); 3522 break; 3523 3524 case SCTP_ERROR_RSRC_LOW: 3525 retval = 1; 3526 break; 3527 3528 case SCTP_ERROR_UNKNOWN_PARAM: 3529 /* Disable sending this type of asconf parameter in 3530 * future. 3531 */ 3532 asoc->peer.addip_disabled_mask |= 3533 asconf_param->param_hdr.type; 3534 break; 3535 3536 case SCTP_ERROR_REQ_REFUSED: 3537 case SCTP_ERROR_DEL_LAST_IP: 3538 case SCTP_ERROR_DEL_SRC_IP: 3539 default: 3540 break; 3541 } 3542 3543 /* Skip the processed asconf parameter and move to the next 3544 * one. 3545 */ 3546 length = ntohs(asconf_param->param_hdr.length); 3547 asconf_param = (void *)asconf_param + length; 3548 asconf_len -= length; 3549 } 3550 3551 if (no_err && asoc->src_out_of_asoc_ok) { 3552 asoc->src_out_of_asoc_ok = 0; 3553 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3554 } 3555 3556 /* Free the cached last sent asconf chunk. */ 3557 list_del_init(&asconf->transmitted_list); 3558 sctp_chunk_free(asconf); 3559 asoc->addip_last_asconf = NULL; 3560 3561 return retval; 3562 } 3563 3564 /* Make a FWD TSN chunk. */ 3565 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3566 __u32 new_cum_tsn, size_t nstreams, 3567 struct sctp_fwdtsn_skip *skiplist) 3568 { 3569 struct sctp_chunk *retval = NULL; 3570 struct sctp_fwdtsn_hdr ftsn_hdr; 3571 struct sctp_fwdtsn_skip skip; 3572 size_t hint; 3573 int i; 3574 3575 hint = (nstreams + 1) * sizeof(__u32); 3576 3577 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC); 3578 3579 if (!retval) 3580 return NULL; 3581 3582 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3583 retval->subh.fwdtsn_hdr = 3584 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3585 3586 for (i = 0; i < nstreams; i++) { 3587 skip.stream = skiplist[i].stream; 3588 skip.ssn = skiplist[i].ssn; 3589 sctp_addto_chunk(retval, sizeof(skip), &skip); 3590 } 3591 3592 return retval; 3593 } 3594 3595 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc, 3596 __u32 new_cum_tsn, size_t nstreams, 3597 struct sctp_ifwdtsn_skip *skiplist) 3598 { 3599 struct sctp_chunk *retval = NULL; 3600 struct sctp_ifwdtsn_hdr ftsn_hdr; 3601 size_t hint; 3602 3603 hint = (nstreams + 1) * sizeof(__u32); 3604 3605 retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint, 3606 GFP_ATOMIC); 3607 if (!retval) 3608 return NULL; 3609 3610 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3611 retval->subh.ifwdtsn_hdr = 3612 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3613 3614 sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist); 3615 3616 return retval; 3617 } 3618 3619 /* RE-CONFIG 3.1 (RE-CONFIG chunk) 3620 * 0 1 2 3 3621 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 3622 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3623 * | Type = 130 | Chunk Flags | Chunk Length | 3624 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3625 * \ \ 3626 * / Re-configuration Parameter / 3627 * \ \ 3628 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3629 * \ \ 3630 * / Re-configuration Parameter (optional) / 3631 * \ \ 3632 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3633 */ 3634 static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc, 3635 int length) 3636 { 3637 struct sctp_reconf_chunk *reconf; 3638 struct sctp_chunk *retval; 3639 3640 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length, 3641 GFP_ATOMIC); 3642 if (!retval) 3643 return NULL; 3644 3645 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr; 3646 retval->param_hdr.v = (u8 *)(reconf + 1); 3647 3648 return retval; 3649 } 3650 3651 /* RE-CONFIG 4.1 (STREAM OUT RESET) 3652 * 0 1 2 3 3653 * 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 3654 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3655 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N | 3656 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3657 * | Re-configuration Request Sequence Number | 3658 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3659 * | Re-configuration Response Sequence Number | 3660 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3661 * | Sender's Last Assigned TSN | 3662 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3663 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3664 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3665 * / ...... / 3666 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3667 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3668 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3669 * 3670 * RE-CONFIG 4.2 (STREAM IN RESET) 3671 * 0 1 2 3 3672 * 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 3673 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3674 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N | 3675 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3676 * | Re-configuration Request Sequence Number | 3677 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3678 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3679 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3680 * / ...... / 3681 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3682 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3683 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3684 */ 3685 struct sctp_chunk *sctp_make_strreset_req( 3686 const struct sctp_association *asoc, 3687 __u16 stream_num, __be16 *stream_list, 3688 bool out, bool in) 3689 { 3690 __u16 stream_len = stream_num * sizeof(__u16); 3691 struct sctp_strreset_outreq outreq; 3692 struct sctp_strreset_inreq inreq; 3693 struct sctp_chunk *retval; 3694 __u16 outlen, inlen; 3695 3696 outlen = (sizeof(outreq) + stream_len) * out; 3697 inlen = (sizeof(inreq) + stream_len) * in; 3698 3699 retval = sctp_make_reconf(asoc, SCTP_PAD4(outlen) + SCTP_PAD4(inlen)); 3700 if (!retval) 3701 return NULL; 3702 3703 if (outlen) { 3704 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST; 3705 outreq.param_hdr.length = htons(outlen); 3706 outreq.request_seq = htonl(asoc->strreset_outseq); 3707 outreq.response_seq = htonl(asoc->strreset_inseq - 1); 3708 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1); 3709 3710 sctp_addto_chunk(retval, sizeof(outreq), &outreq); 3711 3712 if (stream_len) 3713 sctp_addto_chunk(retval, stream_len, stream_list); 3714 } 3715 3716 if (inlen) { 3717 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST; 3718 inreq.param_hdr.length = htons(inlen); 3719 inreq.request_seq = htonl(asoc->strreset_outseq + out); 3720 3721 sctp_addto_chunk(retval, sizeof(inreq), &inreq); 3722 3723 if (stream_len) 3724 sctp_addto_chunk(retval, stream_len, stream_list); 3725 } 3726 3727 return retval; 3728 } 3729 3730 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL) 3731 * 0 1 2 3 3732 * 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 3733 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3734 * | Parameter Type = 15 | Parameter Length = 8 | 3735 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3736 * | Re-configuration Request Sequence Number | 3737 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3738 */ 3739 struct sctp_chunk *sctp_make_strreset_tsnreq( 3740 const struct sctp_association *asoc) 3741 { 3742 struct sctp_strreset_tsnreq tsnreq; 3743 __u16 length = sizeof(tsnreq); 3744 struct sctp_chunk *retval; 3745 3746 retval = sctp_make_reconf(asoc, length); 3747 if (!retval) 3748 return NULL; 3749 3750 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST; 3751 tsnreq.param_hdr.length = htons(length); 3752 tsnreq.request_seq = htonl(asoc->strreset_outseq); 3753 3754 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq); 3755 3756 return retval; 3757 } 3758 3759 /* RE-CONFIG 4.5/4.6 (ADD STREAM) 3760 * 0 1 2 3 3761 * 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 3762 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3763 * | Parameter Type = 17 | Parameter Length = 12 | 3764 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3765 * | Re-configuration Request Sequence Number | 3766 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3767 * | Number of new streams | Reserved | 3768 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3769 */ 3770 struct sctp_chunk *sctp_make_strreset_addstrm( 3771 const struct sctp_association *asoc, 3772 __u16 out, __u16 in) 3773 { 3774 struct sctp_strreset_addstrm addstrm; 3775 __u16 size = sizeof(addstrm); 3776 struct sctp_chunk *retval; 3777 3778 retval = sctp_make_reconf(asoc, (!!out + !!in) * size); 3779 if (!retval) 3780 return NULL; 3781 3782 if (out) { 3783 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS; 3784 addstrm.param_hdr.length = htons(size); 3785 addstrm.number_of_streams = htons(out); 3786 addstrm.request_seq = htonl(asoc->strreset_outseq); 3787 addstrm.reserved = 0; 3788 3789 sctp_addto_chunk(retval, size, &addstrm); 3790 } 3791 3792 if (in) { 3793 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS; 3794 addstrm.param_hdr.length = htons(size); 3795 addstrm.number_of_streams = htons(in); 3796 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out); 3797 addstrm.reserved = 0; 3798 3799 sctp_addto_chunk(retval, size, &addstrm); 3800 } 3801 3802 return retval; 3803 } 3804 3805 /* RE-CONFIG 4.4 (RESP) 3806 * 0 1 2 3 3807 * 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 3808 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3809 * | Parameter Type = 16 | Parameter Length | 3810 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3811 * | Re-configuration Response Sequence Number | 3812 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3813 * | Result | 3814 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3815 */ 3816 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc, 3817 __u32 result, __u32 sn) 3818 { 3819 struct sctp_strreset_resp resp; 3820 __u16 length = sizeof(resp); 3821 struct sctp_chunk *retval; 3822 3823 retval = sctp_make_reconf(asoc, length); 3824 if (!retval) 3825 return NULL; 3826 3827 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3828 resp.param_hdr.length = htons(length); 3829 resp.response_seq = htonl(sn); 3830 resp.result = htonl(result); 3831 3832 sctp_addto_chunk(retval, sizeof(resp), &resp); 3833 3834 return retval; 3835 } 3836 3837 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP) 3838 * 0 1 2 3 3839 * 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 3840 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3841 * | Parameter Type = 16 | Parameter Length | 3842 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3843 * | Re-configuration Response Sequence Number | 3844 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3845 * | Result | 3846 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3847 * | Sender's Next TSN (optional) | 3848 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3849 * | Receiver's Next TSN (optional) | 3850 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3851 */ 3852 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc, 3853 __u32 result, __u32 sn, 3854 __u32 sender_tsn, 3855 __u32 receiver_tsn) 3856 { 3857 struct sctp_strreset_resptsn tsnresp; 3858 __u16 length = sizeof(tsnresp); 3859 struct sctp_chunk *retval; 3860 3861 retval = sctp_make_reconf(asoc, length); 3862 if (!retval) 3863 return NULL; 3864 3865 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3866 tsnresp.param_hdr.length = htons(length); 3867 3868 tsnresp.response_seq = htonl(sn); 3869 tsnresp.result = htonl(result); 3870 tsnresp.senders_next_tsn = htonl(sender_tsn); 3871 tsnresp.receivers_next_tsn = htonl(receiver_tsn); 3872 3873 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp); 3874 3875 return retval; 3876 } 3877 3878 bool sctp_verify_reconf(const struct sctp_association *asoc, 3879 struct sctp_chunk *chunk, 3880 struct sctp_paramhdr **errp) 3881 { 3882 struct sctp_reconf_chunk *hdr; 3883 union sctp_params param; 3884 __be16 last = 0; 3885 __u16 cnt = 0; 3886 3887 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; 3888 sctp_walk_params(param, hdr) { 3889 __u16 length = ntohs(param.p->length); 3890 3891 *errp = param.p; 3892 if (cnt++ > 2) 3893 return false; 3894 switch (param.p->type) { 3895 case SCTP_PARAM_RESET_OUT_REQUEST: 3896 if (length < sizeof(struct sctp_strreset_outreq) || 3897 (last && last != SCTP_PARAM_RESET_RESPONSE && 3898 last != SCTP_PARAM_RESET_IN_REQUEST)) 3899 return false; 3900 break; 3901 case SCTP_PARAM_RESET_IN_REQUEST: 3902 if (length < sizeof(struct sctp_strreset_inreq) || 3903 (last && last != SCTP_PARAM_RESET_OUT_REQUEST)) 3904 return false; 3905 break; 3906 case SCTP_PARAM_RESET_RESPONSE: 3907 if ((length != sizeof(struct sctp_strreset_resp) && 3908 length != sizeof(struct sctp_strreset_resptsn)) || 3909 (last && last != SCTP_PARAM_RESET_RESPONSE && 3910 last != SCTP_PARAM_RESET_OUT_REQUEST)) 3911 return false; 3912 break; 3913 case SCTP_PARAM_RESET_TSN_REQUEST: 3914 if (length != 3915 sizeof(struct sctp_strreset_tsnreq) || last) 3916 return false; 3917 break; 3918 case SCTP_PARAM_RESET_ADD_IN_STREAMS: 3919 if (length != sizeof(struct sctp_strreset_addstrm) || 3920 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS)) 3921 return false; 3922 break; 3923 case SCTP_PARAM_RESET_ADD_OUT_STREAMS: 3924 if (length != sizeof(struct sctp_strreset_addstrm) || 3925 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS)) 3926 return false; 3927 break; 3928 default: 3929 return false; 3930 } 3931 3932 last = param.p->type; 3933 } 3934 3935 return true; 3936 } 3937