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 enum sctp_scope scope; 1737 ktime_t kt; 1738 1739 /* Header size is static data prior to the actual cookie, including 1740 * any padding. 1741 */ 1742 headersize = sizeof(struct sctp_chunkhdr) + 1743 (sizeof(struct sctp_signed_cookie) - 1744 sizeof(struct sctp_cookie)); 1745 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1746 fixed_size = headersize + sizeof(struct sctp_cookie); 1747 1748 /* Verify that the chunk looks like it even has a cookie. 1749 * There must be enough room for our cookie and our peer's 1750 * INIT chunk. 1751 */ 1752 len = ntohs(chunk->chunk_hdr->length); 1753 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1754 goto malformed; 1755 1756 /* Verify that the cookie has been padded out. */ 1757 if (bodysize % SCTP_COOKIE_MULTIPLE) 1758 goto malformed; 1759 1760 /* Process the cookie. */ 1761 cookie = chunk->subh.cookie_hdr; 1762 bear_cookie = &cookie->c; 1763 1764 ch = (struct sctp_chunkhdr *)(bear_cookie + 1); 1765 if (ch->type != SCTP_CID_INIT) 1766 goto malformed; 1767 chlen = ntohs(ch->length); 1768 if (chlen < sizeof(struct sctp_init_chunk)) 1769 goto malformed; 1770 if (chlen > len - fixed_size) 1771 goto malformed; 1772 if (bear_cookie->raw_addr_list_len > len - fixed_size - chlen) 1773 goto malformed; 1774 1775 /* Verify the cookie's MAC, if cookie authentication is enabled. */ 1776 if (sctp_sk(ep->base.sk)->cookie_auth_enable) { 1777 u8 mac[SHA256_DIGEST_SIZE]; 1778 1779 hmac_sha256(&ep->cookie_auth_key, (const u8 *)bear_cookie, 1780 bodysize, mac); 1781 static_assert(sizeof(cookie->mac) == sizeof(mac)); 1782 if (crypto_memneq(mac, cookie->mac, sizeof(mac))) { 1783 *error = -SCTP_IERROR_BAD_SIG; 1784 goto fail; 1785 } 1786 } 1787 1788 /* IG Section 2.35.2: 1789 * 3) Compare the port numbers and the verification tag contained 1790 * within the COOKIE ECHO chunk to the actual port numbers and the 1791 * verification tag within the SCTP common header of the received 1792 * packet. If these values do not match the packet MUST be silently 1793 * discarded, 1794 */ 1795 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1796 *error = -SCTP_IERROR_BAD_TAG; 1797 goto fail; 1798 } 1799 1800 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1801 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1802 *error = -SCTP_IERROR_BAD_PORTS; 1803 goto fail; 1804 } 1805 1806 /* Check to see if the cookie is stale. RFC 9260 Section 5.2.4 1807 * exempts an expired cookie only when both Verification Tags match 1808 * the current association. 1809 * If skb has been timestamped, then use the stamp, otherwise 1810 * use current time. This introduces a small possibility that 1811 * a cookie may be considered expired, but this would only slow 1812 * down the new association establishment instead of every packet. 1813 */ 1814 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1815 kt = skb_get_ktime(skb); 1816 else 1817 kt = ktime_get_real(); 1818 1819 if ((!asoc || 1820 asoc->c.my_vtag != bear_cookie->my_vtag || 1821 asoc->c.peer_vtag != bear_cookie->peer_vtag) && 1822 ktime_before(bear_cookie->expiration, kt)) { 1823 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); 1824 __be32 n = htonl(usecs); 1825 1826 /* 1827 * Section 3.3.10.3 Stale Cookie Error (3) 1828 * 1829 * Cause of error 1830 * --------------- 1831 * Stale Cookie Error: Indicates the receipt of a valid State 1832 * Cookie that has expired. 1833 */ 1834 *errp = sctp_make_op_error(asoc, chunk, 1835 SCTP_ERROR_STALE_COOKIE, &n, 1836 sizeof(n), 0); 1837 if (*errp) 1838 *error = -SCTP_IERROR_STALE_COOKIE; 1839 else 1840 *error = -SCTP_IERROR_NOMEM; 1841 1842 goto fail; 1843 } 1844 1845 /* Make a new base association. */ 1846 scope = sctp_scope(sctp_source(chunk)); 1847 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1848 if (!retval) { 1849 *error = -SCTP_IERROR_NOMEM; 1850 goto fail; 1851 } 1852 1853 /* Set up our peer's port number. */ 1854 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1855 1856 if (!sctp_auth_verify_cookie_params(ep, bear_cookie)) 1857 goto malformed; 1858 1859 /* Populate the association from the cookie. */ 1860 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1861 1862 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1863 GFP_ATOMIC) < 0) { 1864 *error = -SCTP_IERROR_NOMEM; 1865 goto fail; 1866 } 1867 1868 /* Also, add the destination address. */ 1869 if (list_empty(&retval->base.bind_addr.address_list)) { 1870 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1871 sizeof(chunk->dest), SCTP_ADDR_SRC, 1872 GFP_ATOMIC); 1873 } 1874 1875 retval->next_tsn = retval->c.initial_tsn; 1876 retval->ctsn_ack_point = retval->next_tsn - 1; 1877 retval->addip_serial = retval->c.initial_tsn; 1878 retval->strreset_outseq = retval->c.initial_tsn; 1879 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1880 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1881 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1882 1883 /* The INIT stuff will be done by the side effects. */ 1884 return retval; 1885 1886 fail: 1887 if (retval) 1888 sctp_association_free(retval); 1889 1890 return NULL; 1891 1892 malformed: 1893 /* Yikes! The packet is either corrupt or deliberately 1894 * malformed. 1895 */ 1896 *error = -SCTP_IERROR_MALFORMED; 1897 goto fail; 1898 } 1899 1900 /******************************************************************** 1901 * 3rd Level Abstractions 1902 ********************************************************************/ 1903 1904 struct __sctp_missing { 1905 __be32 num_missing; 1906 __be16 type; 1907 } __packed; 1908 1909 /* 1910 * Report a missing mandatory parameter. 1911 */ 1912 static int sctp_process_missing_param(const struct sctp_association *asoc, 1913 enum sctp_param paramtype, 1914 struct sctp_chunk *chunk, 1915 struct sctp_chunk **errp) 1916 { 1917 struct __sctp_missing report; 1918 __u16 len; 1919 1920 len = SCTP_PAD4(sizeof(report)); 1921 1922 /* Make an ERROR chunk, preparing enough room for 1923 * returning multiple unknown parameters. 1924 */ 1925 if (!*errp) 1926 *errp = sctp_make_op_error_space(asoc, chunk, len); 1927 1928 if (*errp) { 1929 report.num_missing = htonl(1); 1930 report.type = paramtype; 1931 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1932 sizeof(report)); 1933 sctp_addto_chunk(*errp, sizeof(report), &report); 1934 } 1935 1936 /* Stop processing this chunk. */ 1937 return 0; 1938 } 1939 1940 /* Report an Invalid Mandatory Parameter. */ 1941 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1942 struct sctp_chunk *chunk, 1943 struct sctp_chunk **errp) 1944 { 1945 /* Invalid Mandatory Parameter Error has no payload. */ 1946 1947 if (!*errp) 1948 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1949 1950 if (*errp) 1951 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1952 1953 /* Stop processing this chunk. */ 1954 return 0; 1955 } 1956 1957 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1958 struct sctp_paramhdr *param, 1959 const struct sctp_chunk *chunk, 1960 struct sctp_chunk **errp) 1961 { 1962 /* This is a fatal error. Any accumulated non-fatal errors are 1963 * not reported. 1964 */ 1965 if (*errp) 1966 sctp_chunk_free(*errp); 1967 1968 /* Create an error chunk and fill it in with our payload. */ 1969 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1970 1971 return 0; 1972 } 1973 1974 1975 /* Do not attempt to handle the HOST_NAME parm. However, do 1976 * send back an indicator to the peer. 1977 */ 1978 static int sctp_process_hn_param(const struct sctp_association *asoc, 1979 union sctp_params param, 1980 struct sctp_chunk *chunk, 1981 struct sctp_chunk **errp) 1982 { 1983 __u16 len = ntohs(param.p->length); 1984 1985 /* Processing of the HOST_NAME parameter will generate an 1986 * ABORT. If we've accumulated any non-fatal errors, they 1987 * would be unrecognized parameters and we should not include 1988 * them in the ABORT. 1989 */ 1990 if (*errp) 1991 sctp_chunk_free(*errp); 1992 1993 *errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_DNS_FAILED, 1994 param.v, len, 0); 1995 1996 /* Stop processing this chunk. */ 1997 return 0; 1998 } 1999 2000 static int sctp_verify_ext_param(struct net *net, 2001 const struct sctp_endpoint *ep, 2002 union sctp_params param) 2003 { 2004 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2005 int have_asconf = 0; 2006 int have_auth = 0; 2007 int i; 2008 2009 for (i = 0; i < num_ext; i++) { 2010 switch (param.ext->chunks[i]) { 2011 case SCTP_CID_AUTH: 2012 have_auth = 1; 2013 break; 2014 case SCTP_CID_ASCONF: 2015 case SCTP_CID_ASCONF_ACK: 2016 have_asconf = 1; 2017 break; 2018 } 2019 } 2020 2021 /* ADD-IP Security: The draft requires us to ABORT or ignore the 2022 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 2023 * only if ADD-IP is turned on and we are not backward-compatible 2024 * mode. 2025 */ 2026 if (net->sctp.addip_noauth) 2027 return 1; 2028 2029 if (ep->asconf_enable && !have_auth && have_asconf) 2030 return 0; 2031 2032 return 1; 2033 } 2034 2035 static void sctp_process_ext_param(struct sctp_association *asoc, 2036 union sctp_params param) 2037 { 2038 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2039 int i; 2040 2041 for (i = 0; i < num_ext; i++) { 2042 switch (param.ext->chunks[i]) { 2043 case SCTP_CID_RECONF: 2044 if (asoc->ep->reconf_enable) 2045 asoc->peer.reconf_capable = 1; 2046 break; 2047 case SCTP_CID_FWD_TSN: 2048 if (asoc->ep->prsctp_enable) 2049 asoc->peer.prsctp_capable = 1; 2050 break; 2051 case SCTP_CID_AUTH: 2052 /* if the peer reports AUTH, assume that he 2053 * supports AUTH. 2054 */ 2055 if (asoc->ep->auth_enable) 2056 asoc->peer.auth_capable = 1; 2057 break; 2058 case SCTP_CID_ASCONF: 2059 case SCTP_CID_ASCONF_ACK: 2060 if (asoc->ep->asconf_enable) 2061 asoc->peer.asconf_capable = 1; 2062 break; 2063 case SCTP_CID_I_DATA: 2064 if (asoc->ep->intl_enable) 2065 asoc->peer.intl_capable = 1; 2066 break; 2067 default: 2068 break; 2069 } 2070 } 2071 } 2072 2073 /* RFC 3.2.1 & the Implementers Guide 2.2. 2074 * 2075 * The Parameter Types are encoded such that the 2076 * highest-order two bits specify the action that must be 2077 * taken if the processing endpoint does not recognize the 2078 * Parameter Type. 2079 * 2080 * 00 - Stop processing this parameter; do not process any further 2081 * parameters within this chunk 2082 * 2083 * 01 - Stop processing this parameter, do not process any further 2084 * parameters within this chunk, and report the unrecognized 2085 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2086 * 2087 * 10 - Skip this parameter and continue processing. 2088 * 2089 * 11 - Skip this parameter and continue processing but 2090 * report the unrecognized parameter in an 2091 * 'Unrecognized Parameter' ERROR chunk. 2092 * 2093 * Return value: 2094 * SCTP_IERROR_NO_ERROR - continue with the chunk 2095 * SCTP_IERROR_ERROR - stop and report an error. 2096 * SCTP_IERROR_NOMEME - out of memory. 2097 */ 2098 static enum sctp_ierror sctp_process_unk_param( 2099 const struct sctp_association *asoc, 2100 union sctp_params param, 2101 struct sctp_chunk *chunk, 2102 struct sctp_chunk **errp) 2103 { 2104 int retval = SCTP_IERROR_NO_ERROR; 2105 2106 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2107 case SCTP_PARAM_ACTION_DISCARD: 2108 retval = SCTP_IERROR_ERROR; 2109 break; 2110 case SCTP_PARAM_ACTION_SKIP: 2111 break; 2112 case SCTP_PARAM_ACTION_DISCARD_ERR: 2113 retval = SCTP_IERROR_ERROR; 2114 fallthrough; 2115 case SCTP_PARAM_ACTION_SKIP_ERR: 2116 /* Make an ERROR chunk, preparing enough room for 2117 * returning multiple unknown parameters. 2118 */ 2119 if (!*errp) { 2120 *errp = sctp_make_op_error_limited(asoc, chunk); 2121 if (!*errp) { 2122 /* If there is no memory for generating the 2123 * ERROR report as specified, an ABORT will be 2124 * triggered to the peer and the association 2125 * won't be established. 2126 */ 2127 retval = SCTP_IERROR_NOMEM; 2128 break; 2129 } 2130 } 2131 2132 if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2133 ntohs(param.p->length))) 2134 sctp_addto_chunk(*errp, ntohs(param.p->length), 2135 param.v); 2136 break; 2137 default: 2138 break; 2139 } 2140 2141 return retval; 2142 } 2143 2144 /* Verify variable length parameters 2145 * Return values: 2146 * SCTP_IERROR_ABORT - trigger an ABORT 2147 * SCTP_IERROR_NOMEM - out of memory (abort) 2148 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2149 * SCTP_IERROR_NO_ERROR - continue with the chunk 2150 */ 2151 static enum sctp_ierror sctp_verify_param(struct net *net, 2152 const struct sctp_endpoint *ep, 2153 const struct sctp_association *asoc, 2154 union sctp_params param, 2155 enum sctp_cid cid, 2156 struct sctp_chunk *chunk, 2157 struct sctp_chunk **err_chunk) 2158 { 2159 struct sctp_hmac_algo_param *hmacs; 2160 int retval = SCTP_IERROR_NO_ERROR; 2161 __u16 n_elt, id = 0; 2162 int i; 2163 2164 /* FIXME - This routine is not looking at each parameter per the 2165 * chunk type, i.e., unrecognized parameters should be further 2166 * identified based on the chunk id. 2167 */ 2168 2169 switch (param.p->type) { 2170 case SCTP_PARAM_IPV4_ADDRESS: 2171 case SCTP_PARAM_IPV6_ADDRESS: 2172 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2173 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2174 case SCTP_PARAM_STATE_COOKIE: 2175 case SCTP_PARAM_HEARTBEAT_INFO: 2176 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2177 case SCTP_PARAM_ECN_CAPABLE: 2178 break; 2179 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2180 if (ntohs(param.p->length) != sizeof(*param.aind)) { 2181 sctp_process_inv_paramlength(asoc, param.p, 2182 chunk, err_chunk); 2183 retval = SCTP_IERROR_ABORT; 2184 } 2185 break; 2186 2187 case SCTP_PARAM_SUPPORTED_EXT: 2188 if (!sctp_verify_ext_param(net, ep, param)) 2189 return SCTP_IERROR_ABORT; 2190 break; 2191 2192 case SCTP_PARAM_SET_PRIMARY: 2193 if (!ep->asconf_enable) 2194 goto unhandled; 2195 2196 if (ntohs(param.p->length) < sizeof(struct sctp_addip_param) + 2197 sizeof(struct sctp_paramhdr)) { 2198 sctp_process_inv_paramlength(asoc, param.p, 2199 chunk, err_chunk); 2200 retval = SCTP_IERROR_ABORT; 2201 } 2202 break; 2203 2204 case SCTP_PARAM_HOST_NAME_ADDRESS: 2205 /* This param has been Deprecated, send ABORT. */ 2206 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2207 retval = SCTP_IERROR_ABORT; 2208 break; 2209 2210 case SCTP_PARAM_FWD_TSN_SUPPORT: 2211 if (ep->prsctp_enable) 2212 break; 2213 goto unhandled; 2214 2215 case SCTP_PARAM_RANDOM: 2216 if (!ep->auth_enable) 2217 goto unhandled; 2218 2219 /* SCTP-AUTH: Secion 6.1 2220 * If the random number is not 32 byte long the association 2221 * MUST be aborted. The ABORT chunk SHOULD contain the error 2222 * cause 'Protocol Violation'. 2223 */ 2224 if (SCTP_AUTH_RANDOM_LENGTH != ntohs(param.p->length) - 2225 sizeof(struct sctp_paramhdr)) { 2226 sctp_process_inv_paramlength(asoc, param.p, 2227 chunk, err_chunk); 2228 retval = SCTP_IERROR_ABORT; 2229 } 2230 break; 2231 2232 case SCTP_PARAM_CHUNKS: 2233 if (!ep->auth_enable) 2234 goto unhandled; 2235 2236 /* SCTP-AUTH: Section 3.2 2237 * The CHUNKS parameter MUST be included once in the INIT or 2238 * INIT-ACK chunk if the sender wants to receive authenticated 2239 * chunks. Its maximum length is 260 bytes. 2240 */ 2241 if (260 < ntohs(param.p->length)) { 2242 sctp_process_inv_paramlength(asoc, param.p, 2243 chunk, err_chunk); 2244 retval = SCTP_IERROR_ABORT; 2245 } 2246 break; 2247 2248 case SCTP_PARAM_HMAC_ALGO: 2249 if (!ep->auth_enable) 2250 goto unhandled; 2251 2252 hmacs = (struct sctp_hmac_algo_param *)param.p; 2253 n_elt = (ntohs(param.p->length) - 2254 sizeof(struct sctp_paramhdr)) >> 1; 2255 2256 /* SCTP-AUTH: Section 6.1 2257 * The HMAC algorithm based on SHA-1 MUST be supported and 2258 * included in the HMAC-ALGO parameter. 2259 */ 2260 for (i = 0; i < n_elt; i++) { 2261 id = ntohs(hmacs->hmac_ids[i]); 2262 2263 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2264 break; 2265 } 2266 2267 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2268 sctp_process_inv_paramlength(asoc, param.p, chunk, 2269 err_chunk); 2270 retval = SCTP_IERROR_ABORT; 2271 } 2272 break; 2273 unhandled: 2274 default: 2275 pr_debug("%s: unrecognized param:%d for chunk:%d\n", 2276 __func__, ntohs(param.p->type), cid); 2277 2278 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2279 break; 2280 } 2281 return retval; 2282 } 2283 2284 /* Verify the INIT packet before we process it. */ 2285 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 2286 const struct sctp_association *asoc, enum sctp_cid cid, 2287 struct sctp_init_chunk *peer_init, 2288 struct sctp_chunk *chunk, struct sctp_chunk **errp) 2289 { 2290 union sctp_params param; 2291 bool has_cookie = false; 2292 int result; 2293 2294 /* Check for missing mandatory parameters. Note: Initial TSN is 2295 * also mandatory, but is not checked here since the valid range 2296 * is 0..2**32-1. RFC4960, section 3.3.3. 2297 */ 2298 if (peer_init->init_hdr.num_outbound_streams == 0 || 2299 peer_init->init_hdr.num_inbound_streams == 0 || 2300 peer_init->init_hdr.init_tag == 0 || 2301 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) 2302 return sctp_process_inv_mandatory(asoc, chunk, errp); 2303 2304 sctp_walk_params(param, peer_init) { 2305 if (param.p->type == SCTP_PARAM_STATE_COOKIE) 2306 has_cookie = true; 2307 } 2308 2309 /* There is a possibility that a parameter length was bad and 2310 * in that case we would have stoped walking the parameters. 2311 * The current param.p would point at the bad one. 2312 * Current consensus on the mailing list is to generate a PROTOCOL 2313 * VIOLATION error. We build the ERROR chunk here and let the normal 2314 * error handling code build and send the packet. 2315 */ 2316 if (param.v != (void *)peer_init + 2317 SCTP_PAD4(ntohs(peer_init->chunk_hdr.length))) 2318 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2319 2320 /* The only missing mandatory param possible today is 2321 * the state cookie for an INIT-ACK chunk. 2322 */ 2323 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2324 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2325 chunk, errp); 2326 2327 /* Verify all the variable length parameters */ 2328 sctp_walk_params(param, peer_init) { 2329 result = sctp_verify_param(net, ep, asoc, param, cid, 2330 chunk, errp); 2331 switch (result) { 2332 case SCTP_IERROR_ABORT: 2333 case SCTP_IERROR_NOMEM: 2334 return 0; 2335 case SCTP_IERROR_ERROR: 2336 return 1; 2337 case SCTP_IERROR_NO_ERROR: 2338 default: 2339 break; 2340 } 2341 2342 } /* for (loop through all parameters) */ 2343 2344 return 1; 2345 } 2346 2347 /* Unpack the parameters in an INIT packet into an association. 2348 * Returns 0 on failure, else success. 2349 * FIXME: This is an association method. 2350 */ 2351 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2352 const union sctp_addr *peer_addr, 2353 struct sctp_init_chunk *peer_init, gfp_t gfp) 2354 { 2355 struct sctp_transport *transport; 2356 struct list_head *pos, *temp; 2357 union sctp_params param; 2358 union sctp_addr addr; 2359 struct sctp_af *af; 2360 int src_match = 0; 2361 2362 /* We must include the address that the INIT packet came from. 2363 * This is the only address that matters for an INIT packet. 2364 * When processing a COOKIE ECHO, we retrieve the from address 2365 * of the INIT from the cookie. 2366 */ 2367 2368 /* This implementation defaults to making the first transport 2369 * added as the primary transport. The source address seems to 2370 * be a better choice than any of the embedded addresses. 2371 */ 2372 asoc->encap_port = SCTP_INPUT_CB(chunk->skb)->encap_port; 2373 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2374 goto nomem; 2375 2376 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2377 src_match = 1; 2378 2379 /* Process the initialization parameters. */ 2380 sctp_walk_params(param, peer_init) { 2381 if (!src_match && 2382 (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2383 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2384 af = sctp_get_af_specific(param_type2af(param.p->type)); 2385 if (!af->from_addr_param(&addr, param.addr, 2386 chunk->sctp_hdr->source, 0)) 2387 continue; 2388 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2389 src_match = 1; 2390 } 2391 2392 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2393 goto clean_up; 2394 } 2395 2396 /* source address of chunk may not match any valid address */ 2397 if (!src_match) 2398 goto clean_up; 2399 2400 /* AUTH: After processing the parameters, make sure that we 2401 * have all the required info to potentially do authentications. 2402 */ 2403 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2404 !asoc->peer.peer_hmacs)) 2405 asoc->peer.auth_capable = 0; 2406 2407 /* In a non-backward compatible mode, if the peer claims 2408 * support for ADD-IP but not AUTH, the ADD-IP spec states 2409 * that we MUST ABORT the association. Section 6. The section 2410 * also give us an option to silently ignore the packet, which 2411 * is what we'll do here. 2412 */ 2413 if (!asoc->base.net->sctp.addip_noauth && 2414 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2415 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2416 SCTP_PARAM_DEL_IP | 2417 SCTP_PARAM_SET_PRIMARY); 2418 asoc->peer.asconf_capable = 0; 2419 goto clean_up; 2420 } 2421 2422 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2423 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2424 transport = list_entry(pos, struct sctp_transport, transports); 2425 if (transport->state == SCTP_UNKNOWN) { 2426 sctp_assoc_rm_peer(asoc, transport); 2427 } 2428 } 2429 2430 /* The fixed INIT headers are always in network byte 2431 * order. 2432 */ 2433 asoc->peer.i.init_tag = 2434 ntohl(peer_init->init_hdr.init_tag); 2435 asoc->peer.i.a_rwnd = 2436 ntohl(peer_init->init_hdr.a_rwnd); 2437 asoc->peer.i.num_outbound_streams = 2438 ntohs(peer_init->init_hdr.num_outbound_streams); 2439 asoc->peer.i.num_inbound_streams = 2440 ntohs(peer_init->init_hdr.num_inbound_streams); 2441 asoc->peer.i.initial_tsn = 2442 ntohl(peer_init->init_hdr.initial_tsn); 2443 2444 asoc->strreset_inseq = asoc->peer.i.initial_tsn; 2445 2446 /* Apply the upper bounds for output streams based on peer's 2447 * number of inbound streams. 2448 */ 2449 if (asoc->c.sinit_num_ostreams > 2450 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2451 asoc->c.sinit_num_ostreams = 2452 ntohs(peer_init->init_hdr.num_inbound_streams); 2453 } 2454 2455 if (asoc->c.sinit_max_instreams > 2456 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2457 asoc->c.sinit_max_instreams = 2458 ntohs(peer_init->init_hdr.num_outbound_streams); 2459 } 2460 2461 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2462 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2463 2464 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2465 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2466 2467 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2468 * high (for example, implementations MAY use the size of the receiver 2469 * advertised window). 2470 */ 2471 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2472 transports) { 2473 transport->ssthresh = asoc->peer.i.a_rwnd; 2474 } 2475 2476 /* Set up the TSN tracking pieces. */ 2477 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2478 asoc->peer.i.initial_tsn, gfp)) 2479 goto clean_up; 2480 2481 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2482 * 2483 * The stream sequence number in all the streams shall start 2484 * from 0 when the association is established. Also, when the 2485 * stream sequence number reaches the value 65535 the next 2486 * stream sequence number shall be set to 0. 2487 */ 2488 2489 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams, 2490 asoc->c.sinit_max_instreams, gfp)) 2491 goto clean_up; 2492 2493 /* Update frag_point when stream_interleave may get changed. */ 2494 sctp_assoc_update_frag_point(asoc); 2495 2496 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp)) 2497 goto clean_up; 2498 2499 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2500 * 2501 * When an endpoint has an ASCONF signaled change to be sent to the 2502 * remote endpoint it should do the following: 2503 * ... 2504 * A2) A serial number should be assigned to the Chunk. The serial 2505 * number should be a monotonically increasing number. All serial 2506 * numbers are defined to be initialized at the start of the 2507 * association to the same value as the Initial TSN. 2508 */ 2509 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2510 return 1; 2511 2512 clean_up: 2513 /* Release the transport structures. */ 2514 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2515 transport = list_entry(pos, struct sctp_transport, transports); 2516 if (transport->state != SCTP_ACTIVE) 2517 sctp_assoc_rm_peer(asoc, transport); 2518 } 2519 2520 nomem: 2521 return 0; 2522 } 2523 2524 2525 /* Update asoc with the option described in param. 2526 * 2527 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2528 * 2529 * asoc is the association to update. 2530 * param is the variable length parameter to use for update. 2531 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2532 * If the current packet is an INIT we want to minimize the amount of 2533 * work we do. In particular, we should not build transport 2534 * structures for the addresses. 2535 */ 2536 static int sctp_process_param(struct sctp_association *asoc, 2537 union sctp_params param, 2538 const union sctp_addr *peer_addr, 2539 gfp_t gfp) 2540 { 2541 struct sctp_endpoint *ep = asoc->ep; 2542 union sctp_addr_param *addr_param; 2543 struct net *net = asoc->base.net; 2544 struct sctp_transport *t; 2545 enum sctp_scope scope; 2546 union sctp_addr addr; 2547 struct sctp_af *af; 2548 int retval = 1, i; 2549 u32 stale; 2550 __u16 sat; 2551 2552 /* We maintain all INIT parameters in network byte order all the 2553 * time. This allows us to not worry about whether the parameters 2554 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2555 */ 2556 switch (param.p->type) { 2557 case SCTP_PARAM_IPV6_ADDRESS: 2558 if (PF_INET6 != asoc->base.sk->sk_family) 2559 break; 2560 goto do_addr_param; 2561 2562 case SCTP_PARAM_IPV4_ADDRESS: 2563 /* v4 addresses are not allowed on v6-only socket */ 2564 if (ipv6_only_sock(asoc->base.sk)) 2565 break; 2566 do_addr_param: 2567 af = sctp_get_af_specific(param_type2af(param.p->type)); 2568 if (!af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0)) 2569 break; 2570 scope = sctp_scope(peer_addr); 2571 if (sctp_in_scope(net, &addr, scope)) 2572 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2573 return 0; 2574 break; 2575 2576 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2577 if (!net->sctp.cookie_preserve_enable) 2578 break; 2579 2580 stale = ntohl(param.life->lifespan_increment); 2581 2582 /* Suggested Cookie Life span increment's unit is msec, 2583 * (1/1000sec). 2584 */ 2585 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale); 2586 break; 2587 2588 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2589 /* Turn off the default values first so we'll know which 2590 * ones are really set by the peer. 2591 */ 2592 asoc->peer.ipv4_address = 0; 2593 asoc->peer.ipv6_address = 0; 2594 2595 /* Assume that peer supports the address family 2596 * by which it sends a packet. 2597 */ 2598 if (peer_addr->sa.sa_family == AF_INET6) 2599 asoc->peer.ipv6_address = 1; 2600 else if (peer_addr->sa.sa_family == AF_INET) 2601 asoc->peer.ipv4_address = 1; 2602 2603 /* Cycle through address types; avoid divide by 0. */ 2604 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2605 if (sat) 2606 sat /= sizeof(__u16); 2607 2608 for (i = 0; i < sat; ++i) { 2609 switch (param.sat->types[i]) { 2610 case SCTP_PARAM_IPV4_ADDRESS: 2611 asoc->peer.ipv4_address = 1; 2612 break; 2613 2614 case SCTP_PARAM_IPV6_ADDRESS: 2615 if (PF_INET6 == asoc->base.sk->sk_family) 2616 asoc->peer.ipv6_address = 1; 2617 break; 2618 2619 default: /* Just ignore anything else. */ 2620 break; 2621 } 2622 } 2623 break; 2624 2625 case SCTP_PARAM_STATE_COOKIE: 2626 asoc->peer.cookie_len = 2627 ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2628 kfree(asoc->peer.cookie); 2629 asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp); 2630 if (!asoc->peer.cookie) 2631 retval = 0; 2632 break; 2633 2634 case SCTP_PARAM_HEARTBEAT_INFO: 2635 /* Would be odd to receive, but it causes no problems. */ 2636 break; 2637 2638 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2639 /* Rejected during verify stage. */ 2640 break; 2641 2642 case SCTP_PARAM_ECN_CAPABLE: 2643 if (asoc->ep->ecn_enable) { 2644 asoc->peer.ecn_capable = 1; 2645 break; 2646 } 2647 /* Fall Through */ 2648 goto fall_through; 2649 2650 2651 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2652 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2653 break; 2654 2655 case SCTP_PARAM_SET_PRIMARY: 2656 if (!ep->asconf_enable) 2657 goto fall_through; 2658 2659 addr_param = param.v + sizeof(struct sctp_addip_param); 2660 if (ntohs(addr_param->p.length) > 2661 ntohs(param.p->length) - sizeof(struct sctp_addip_param)) 2662 break; 2663 2664 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 2665 if (!af) 2666 break; 2667 2668 if (!af->from_addr_param(&addr, addr_param, 2669 htons(asoc->peer.port), 0)) 2670 break; 2671 2672 if (!af->addr_valid(&addr, NULL, NULL)) 2673 break; 2674 2675 t = sctp_assoc_lookup_paddr(asoc, &addr); 2676 if (!t) 2677 break; 2678 2679 sctp_assoc_set_primary(asoc, t); 2680 break; 2681 2682 case SCTP_PARAM_SUPPORTED_EXT: 2683 sctp_process_ext_param(asoc, param); 2684 break; 2685 2686 case SCTP_PARAM_FWD_TSN_SUPPORT: 2687 if (asoc->ep->prsctp_enable) { 2688 asoc->peer.prsctp_capable = 1; 2689 break; 2690 } 2691 /* Fall Through */ 2692 goto fall_through; 2693 2694 case SCTP_PARAM_RANDOM: 2695 if (!ep->auth_enable) 2696 goto fall_through; 2697 2698 /* Save peer's random parameter */ 2699 kfree(asoc->peer.peer_random); 2700 asoc->peer.peer_random = kmemdup(param.p, 2701 ntohs(param.p->length), gfp); 2702 if (!asoc->peer.peer_random) { 2703 retval = 0; 2704 break; 2705 } 2706 break; 2707 2708 case SCTP_PARAM_HMAC_ALGO: 2709 if (!ep->auth_enable) 2710 goto fall_through; 2711 2712 /* Save peer's HMAC list */ 2713 kfree(asoc->peer.peer_hmacs); 2714 asoc->peer.peer_hmacs = kmemdup(param.p, 2715 ntohs(param.p->length), gfp); 2716 if (!asoc->peer.peer_hmacs) { 2717 retval = 0; 2718 break; 2719 } 2720 2721 /* Set the default HMAC the peer requested*/ 2722 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2723 break; 2724 2725 case SCTP_PARAM_CHUNKS: 2726 if (!ep->auth_enable) 2727 goto fall_through; 2728 2729 kfree(asoc->peer.peer_chunks); 2730 asoc->peer.peer_chunks = kmemdup(param.p, 2731 ntohs(param.p->length), gfp); 2732 if (!asoc->peer.peer_chunks) 2733 retval = 0; 2734 break; 2735 fall_through: 2736 default: 2737 /* Any unrecognized parameters should have been caught 2738 * and handled by sctp_verify_param() which should be 2739 * called prior to this routine. Simply log the error 2740 * here. 2741 */ 2742 pr_debug("%s: ignoring param:%d for association:%p.\n", 2743 __func__, ntohs(param.p->type), asoc); 2744 break; 2745 } 2746 2747 return retval; 2748 } 2749 2750 /* Select a new verification tag. */ 2751 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2752 { 2753 /* I believe that this random number generator complies with RFC1750. 2754 * A tag of 0 is reserved for special cases (e.g. INIT). 2755 */ 2756 __u32 x; 2757 2758 do { 2759 x = get_random_u32(); 2760 } while (x == 0); 2761 2762 return x; 2763 } 2764 2765 /* Select an initial TSN to send during startup. */ 2766 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2767 { 2768 __u32 retval; 2769 2770 retval = get_random_u32(); 2771 return retval; 2772 } 2773 2774 /* 2775 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2776 * 0 1 2 3 2777 * 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 2778 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2779 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2780 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2781 * | Serial Number | 2782 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2783 * | Address Parameter | 2784 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2785 * | ASCONF Parameter #1 | 2786 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2787 * \ \ 2788 * / .... / 2789 * \ \ 2790 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2791 * | ASCONF Parameter #N | 2792 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2793 * 2794 * Address Parameter and other parameter will not be wrapped in this function 2795 */ 2796 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2797 union sctp_addr *addr, 2798 int vparam_len) 2799 { 2800 struct sctp_addiphdr asconf; 2801 struct sctp_chunk *retval; 2802 int length = sizeof(asconf) + vparam_len; 2803 union sctp_addr_param addrparam; 2804 int addrlen; 2805 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2806 2807 addrlen = af->to_addr_param(addr, &addrparam); 2808 if (!addrlen) 2809 return NULL; 2810 length += addrlen; 2811 2812 /* Create the chunk. */ 2813 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length, 2814 GFP_ATOMIC); 2815 if (!retval) 2816 return NULL; 2817 2818 asconf.serial = htonl(asoc->addip_serial++); 2819 2820 retval->subh.addip_hdr = 2821 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2822 retval->param_hdr.v = 2823 sctp_addto_chunk(retval, addrlen, &addrparam); 2824 2825 return retval; 2826 } 2827 2828 /* ADDIP 2829 * 3.2.1 Add IP Address 2830 * 0 1 2 3 2831 * 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 2832 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2833 * | Type = 0xC001 | Length = Variable | 2834 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2835 * | ASCONF-Request Correlation ID | 2836 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2837 * | Address Parameter | 2838 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2839 * 2840 * 3.2.2 Delete IP Address 2841 * 0 1 2 3 2842 * 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 2843 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2844 * | Type = 0xC002 | Length = Variable | 2845 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2846 * | ASCONF-Request Correlation ID | 2847 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2848 * | Address Parameter | 2849 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2850 * 2851 */ 2852 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2853 union sctp_addr *laddr, 2854 struct sockaddr *addrs, 2855 int addrcnt, __be16 flags) 2856 { 2857 union sctp_addr_param addr_param; 2858 struct sctp_addip_param param; 2859 int paramlen = sizeof(param); 2860 struct sctp_chunk *retval; 2861 int addr_param_len = 0; 2862 union sctp_addr *addr; 2863 int totallen = 0, i; 2864 int del_pickup = 0; 2865 struct sctp_af *af; 2866 void *addr_buf; 2867 2868 /* Get total length of all the address parameters. */ 2869 addr_buf = addrs; 2870 for (i = 0; i < addrcnt; i++) { 2871 addr = addr_buf; 2872 af = sctp_get_af_specific(addr->v4.sin_family); 2873 addr_param_len = af->to_addr_param(addr, &addr_param); 2874 2875 totallen += paramlen; 2876 totallen += addr_param_len; 2877 2878 addr_buf += af->sockaddr_len; 2879 if (asoc->asconf_addr_del_pending && !del_pickup) { 2880 /* reuse the parameter length from the same scope one */ 2881 totallen += paramlen; 2882 totallen += addr_param_len; 2883 del_pickup = 1; 2884 2885 pr_debug("%s: picked same-scope del_pending addr, " 2886 "totallen for all addresses is %d\n", 2887 __func__, totallen); 2888 } 2889 } 2890 2891 /* Create an asconf chunk with the required length. */ 2892 retval = sctp_make_asconf(asoc, laddr, totallen); 2893 if (!retval) 2894 return NULL; 2895 2896 /* Add the address parameters to the asconf chunk. */ 2897 addr_buf = addrs; 2898 for (i = 0; i < addrcnt; i++) { 2899 addr = addr_buf; 2900 af = sctp_get_af_specific(addr->v4.sin_family); 2901 addr_param_len = af->to_addr_param(addr, &addr_param); 2902 param.param_hdr.type = flags; 2903 param.param_hdr.length = htons(paramlen + addr_param_len); 2904 param.crr_id = htonl(i); 2905 2906 sctp_addto_chunk(retval, paramlen, ¶m); 2907 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2908 2909 addr_buf += af->sockaddr_len; 2910 } 2911 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2912 addr = asoc->asconf_addr_del_pending; 2913 af = sctp_get_af_specific(addr->v4.sin_family); 2914 addr_param_len = af->to_addr_param(addr, &addr_param); 2915 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2916 param.param_hdr.length = htons(paramlen + addr_param_len); 2917 param.crr_id = htonl(i); 2918 2919 sctp_addto_chunk(retval, paramlen, ¶m); 2920 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2921 } 2922 return retval; 2923 } 2924 2925 /* ADDIP 2926 * 3.2.4 Set Primary IP Address 2927 * 0 1 2 3 2928 * 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 2929 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2930 * | Type =0xC004 | Length = Variable | 2931 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2932 * | ASCONF-Request Correlation ID | 2933 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2934 * | Address Parameter | 2935 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2936 * 2937 * Create an ASCONF chunk with Set Primary IP address parameter. 2938 */ 2939 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2940 union sctp_addr *addr) 2941 { 2942 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2943 union sctp_addr_param addrparam; 2944 struct sctp_addip_param param; 2945 struct sctp_chunk *retval; 2946 int len = sizeof(param); 2947 int addrlen; 2948 2949 addrlen = af->to_addr_param(addr, &addrparam); 2950 if (!addrlen) 2951 return NULL; 2952 len += addrlen; 2953 2954 /* Create the chunk and make asconf header. */ 2955 retval = sctp_make_asconf(asoc, addr, len); 2956 if (!retval) 2957 return NULL; 2958 2959 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2960 param.param_hdr.length = htons(len); 2961 param.crr_id = 0; 2962 2963 sctp_addto_chunk(retval, sizeof(param), ¶m); 2964 sctp_addto_chunk(retval, addrlen, &addrparam); 2965 2966 return retval; 2967 } 2968 2969 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2970 * 0 1 2 3 2971 * 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 2972 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2973 * | Type = 0x80 | Chunk Flags | Chunk Length | 2974 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2975 * | Serial Number | 2976 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2977 * | ASCONF Parameter Response#1 | 2978 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2979 * \ \ 2980 * / .... / 2981 * \ \ 2982 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2983 * | ASCONF Parameter Response#N | 2984 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2985 * 2986 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2987 */ 2988 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2989 __u32 serial, int vparam_len) 2990 { 2991 struct sctp_addiphdr asconf; 2992 struct sctp_chunk *retval; 2993 int length = sizeof(asconf) + vparam_len; 2994 2995 /* Create the chunk. */ 2996 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length, 2997 GFP_ATOMIC); 2998 if (!retval) 2999 return NULL; 3000 3001 asconf.serial = htonl(serial); 3002 3003 retval->subh.addip_hdr = 3004 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 3005 3006 return retval; 3007 } 3008 3009 /* Add response parameters to an ASCONF_ACK chunk. */ 3010 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 3011 __be16 err_code, 3012 struct sctp_addip_param *asconf_param) 3013 { 3014 struct sctp_addip_param ack_param; 3015 struct sctp_errhdr err_param; 3016 int asconf_param_len = 0; 3017 int err_param_len = 0; 3018 __be16 response_type; 3019 3020 if (SCTP_ERROR_NO_ERROR == err_code) { 3021 response_type = SCTP_PARAM_SUCCESS_REPORT; 3022 } else { 3023 response_type = SCTP_PARAM_ERR_CAUSE; 3024 err_param_len = sizeof(err_param); 3025 if (asconf_param) 3026 asconf_param_len = 3027 ntohs(asconf_param->param_hdr.length); 3028 } 3029 3030 /* Add Success Indication or Error Cause Indication parameter. */ 3031 ack_param.param_hdr.type = response_type; 3032 ack_param.param_hdr.length = htons(sizeof(ack_param) + 3033 err_param_len + 3034 asconf_param_len); 3035 ack_param.crr_id = crr_id; 3036 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 3037 3038 if (SCTP_ERROR_NO_ERROR == err_code) 3039 return; 3040 3041 /* Add Error Cause parameter. */ 3042 err_param.cause = err_code; 3043 err_param.length = htons(err_param_len + asconf_param_len); 3044 sctp_addto_chunk(chunk, err_param_len, &err_param); 3045 3046 /* Add the failed TLV copied from ASCONF chunk. */ 3047 if (asconf_param) 3048 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 3049 } 3050 3051 /* Process a asconf parameter. */ 3052 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 3053 struct sctp_chunk *asconf, 3054 struct sctp_addip_param *asconf_param) 3055 { 3056 union sctp_addr_param *addr_param; 3057 struct sctp_transport *peer; 3058 union sctp_addr addr; 3059 struct sctp_af *af; 3060 3061 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 3062 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 3063 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 3064 return SCTP_ERROR_UNKNOWN_PARAM; 3065 3066 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3067 if (ntohs(addr_param->p.length) > 3068 ntohs(asconf_param->param_hdr.length) - sizeof(*asconf_param)) 3069 return SCTP_ERROR_PROTO_VIOLATION; 3070 3071 switch (addr_param->p.type) { 3072 case SCTP_PARAM_IPV6_ADDRESS: 3073 if (!asoc->peer.ipv6_address) 3074 return SCTP_ERROR_DNS_FAILED; 3075 break; 3076 case SCTP_PARAM_IPV4_ADDRESS: 3077 if (!asoc->peer.ipv4_address) 3078 return SCTP_ERROR_DNS_FAILED; 3079 break; 3080 default: 3081 return SCTP_ERROR_DNS_FAILED; 3082 } 3083 3084 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3085 if (unlikely(!af)) 3086 return SCTP_ERROR_DNS_FAILED; 3087 3088 if (!af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0)) 3089 return SCTP_ERROR_DNS_FAILED; 3090 3091 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3092 * or multicast address. 3093 * (note: wildcard is permitted and requires special handling so 3094 * make sure we check for that) 3095 */ 3096 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3097 return SCTP_ERROR_DNS_FAILED; 3098 3099 switch (asconf_param->param_hdr.type) { 3100 case SCTP_PARAM_ADD_IP: 3101 /* Section 4.2.1: 3102 * If the address 0.0.0.0 or ::0 is provided, the source 3103 * address of the packet MUST be added. 3104 */ 3105 if (af->is_any(&addr)) 3106 memcpy(&addr, &asconf->source, sizeof(addr)); 3107 3108 if (security_sctp_bind_connect(asoc->ep->base.sk, 3109 SCTP_PARAM_ADD_IP, 3110 (struct sockaddr *)&addr, 3111 af->sockaddr_len)) 3112 return SCTP_ERROR_REQ_REFUSED; 3113 3114 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3115 * request and does not have the local resources to add this 3116 * new address to the association, it MUST return an Error 3117 * Cause TLV set to the new error code 'Operation Refused 3118 * Due to Resource Shortage'. 3119 */ 3120 3121 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3122 if (!peer) 3123 return SCTP_ERROR_RSRC_LOW; 3124 3125 /* Start the heartbeat timer. */ 3126 sctp_transport_reset_hb_timer(peer); 3127 asoc->new_transport = peer; 3128 break; 3129 case SCTP_PARAM_DEL_IP: 3130 /* ADDIP 4.3 D7) If a request is received to delete the 3131 * last remaining IP address of a peer endpoint, the receiver 3132 * MUST send an Error Cause TLV with the error cause set to the 3133 * new error code 'Request to Delete Last Remaining IP Address'. 3134 */ 3135 if (asoc->peer.transport_count == 1) 3136 return SCTP_ERROR_DEL_LAST_IP; 3137 3138 /* ADDIP 4.3 D8) If a request is received to delete an IP 3139 * address which is also the source address of the IP packet 3140 * which contained the ASCONF chunk, the receiver MUST reject 3141 * this request. To reject the request the receiver MUST send 3142 * an Error Cause TLV set to the new error code 'Request to 3143 * Delete Source IP Address' 3144 */ 3145 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3146 return SCTP_ERROR_DEL_SRC_IP; 3147 3148 /* Section 4.2.2 3149 * If the address 0.0.0.0 or ::0 is provided, all 3150 * addresses of the peer except the source address of the 3151 * packet MUST be deleted. 3152 */ 3153 if (af->is_any(&addr)) { 3154 sctp_assoc_set_primary(asoc, asconf->transport); 3155 sctp_assoc_del_nonprimary_peers(asoc, 3156 asconf->transport); 3157 return SCTP_ERROR_NO_ERROR; 3158 } 3159 3160 /* If the address is not part of the association, the 3161 * ASCONF-ACK with Error Cause Indication Parameter 3162 * which including cause of Unresolvable Address should 3163 * be sent. 3164 */ 3165 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3166 if (!peer) 3167 return SCTP_ERROR_DNS_FAILED; 3168 3169 /* Don't free asconf->transport; a later wildcard DEL-IP 3170 * parameter reuses it. 3171 */ 3172 if (peer == asconf->transport) 3173 return SCTP_ERROR_REQ_REFUSED; 3174 3175 sctp_assoc_rm_peer(asoc, peer); 3176 break; 3177 case SCTP_PARAM_SET_PRIMARY: 3178 /* ADDIP Section 4.2.4 3179 * If the address 0.0.0.0 or ::0 is provided, the receiver 3180 * MAY mark the source address of the packet as its 3181 * primary. 3182 */ 3183 if (af->is_any(&addr)) 3184 memcpy(&addr, sctp_source(asconf), sizeof(addr)); 3185 3186 if (security_sctp_bind_connect(asoc->ep->base.sk, 3187 SCTP_PARAM_SET_PRIMARY, 3188 (struct sockaddr *)&addr, 3189 af->sockaddr_len)) 3190 return SCTP_ERROR_REQ_REFUSED; 3191 3192 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3193 if (!peer) 3194 return SCTP_ERROR_DNS_FAILED; 3195 3196 sctp_assoc_set_primary(asoc, peer); 3197 break; 3198 } 3199 3200 return SCTP_ERROR_NO_ERROR; 3201 } 3202 3203 /* Verify the ASCONF packet before we process it. */ 3204 bool sctp_verify_asconf(const struct sctp_association *asoc, 3205 struct sctp_chunk *chunk, bool addr_param_needed, 3206 struct sctp_paramhdr **errp) 3207 { 3208 struct sctp_addip_chunk *addip; 3209 bool addr_param_seen = false; 3210 union sctp_params param; 3211 3212 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr; 3213 sctp_walk_params(param, addip) { 3214 size_t length = ntohs(param.p->length); 3215 3216 *errp = param.p; 3217 switch (param.p->type) { 3218 case SCTP_PARAM_ERR_CAUSE: 3219 if (length < sizeof(struct sctp_addip_param) + 3220 sizeof(struct sctp_errhdr)) 3221 return false; 3222 break; 3223 case SCTP_PARAM_IPV4_ADDRESS: 3224 if (length != sizeof(struct sctp_ipv4addr_param)) 3225 return false; 3226 /* ensure there is only one addr param and it's in the 3227 * beginning of addip_hdr params, or we reject it. 3228 */ 3229 if (param.v != (addip + 1)) 3230 return false; 3231 addr_param_seen = true; 3232 break; 3233 case SCTP_PARAM_IPV6_ADDRESS: 3234 if (length != sizeof(struct sctp_ipv6addr_param)) 3235 return false; 3236 if (param.v != (addip + 1)) 3237 return false; 3238 addr_param_seen = true; 3239 break; 3240 case SCTP_PARAM_ADD_IP: 3241 case SCTP_PARAM_DEL_IP: 3242 case SCTP_PARAM_SET_PRIMARY: 3243 /* In ASCONF chunks, these need to be first. */ 3244 if (addr_param_needed && !addr_param_seen) 3245 return false; 3246 length = ntohs(param.addip->param_hdr.length); 3247 if (length < sizeof(struct sctp_addip_param) + 3248 sizeof(**errp)) 3249 return false; 3250 break; 3251 case SCTP_PARAM_SUCCESS_REPORT: 3252 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3253 if (length != sizeof(struct sctp_addip_param)) 3254 return false; 3255 break; 3256 default: 3257 /* This is unknown to us, reject! */ 3258 return false; 3259 } 3260 } 3261 3262 /* Remaining sanity checks. */ 3263 if (addr_param_needed && !addr_param_seen) 3264 return false; 3265 if (!addr_param_needed && addr_param_seen) 3266 return false; 3267 if (param.v != chunk->chunk_end) 3268 return false; 3269 3270 return true; 3271 } 3272 3273 /* Process an incoming ASCONF chunk with the next expected serial no. and 3274 * return an ASCONF_ACK chunk to be sent in response. 3275 */ 3276 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3277 struct sctp_chunk *asconf) 3278 { 3279 union sctp_addr_param *addr_param; 3280 struct sctp_addip_chunk *addip; 3281 struct sctp_chunk *asconf_ack; 3282 bool all_param_pass = true; 3283 struct sctp_addiphdr *hdr; 3284 int length = 0, chunk_len; 3285 union sctp_params param; 3286 __be16 err_code; 3287 __u32 serial; 3288 3289 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr; 3290 chunk_len = ntohs(asconf->chunk_hdr->length) - 3291 sizeof(struct sctp_chunkhdr); 3292 hdr = (struct sctp_addiphdr *)asconf->skb->data; 3293 serial = ntohl(hdr->serial); 3294 3295 /* Skip the addiphdr and store a pointer to address parameter. */ 3296 length = sizeof(*hdr); 3297 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3298 chunk_len -= length; 3299 3300 /* Skip the address parameter and store a pointer to the first 3301 * asconf parameter. 3302 */ 3303 length = ntohs(addr_param->p.length); 3304 chunk_len -= length; 3305 3306 /* create an ASCONF_ACK chunk. 3307 * Based on the definitions of parameters, we know that the size of 3308 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3309 * parameters. 3310 */ 3311 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3312 if (!asconf_ack) 3313 goto done; 3314 3315 /* Process the TLVs contained within the ASCONF chunk. */ 3316 sctp_walk_params(param, addip) { 3317 /* Skip preceding address parameters. */ 3318 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 3319 param.p->type == SCTP_PARAM_IPV6_ADDRESS) 3320 continue; 3321 3322 err_code = sctp_process_asconf_param(asoc, asconf, 3323 param.addip); 3324 /* ADDIP 4.1 A7) 3325 * If an error response is received for a TLV parameter, 3326 * all TLVs with no response before the failed TLV are 3327 * considered successful if not reported. All TLVs after 3328 * the failed response are considered unsuccessful unless 3329 * a specific success indication is present for the parameter. 3330 */ 3331 if (err_code != SCTP_ERROR_NO_ERROR) 3332 all_param_pass = false; 3333 if (!all_param_pass) 3334 sctp_add_asconf_response(asconf_ack, param.addip->crr_id, 3335 err_code, param.addip); 3336 3337 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3338 * an IP address sends an 'Out of Resource' in its response, it 3339 * MUST also fail any subsequent add or delete requests bundled 3340 * in the ASCONF. 3341 */ 3342 if (err_code == SCTP_ERROR_RSRC_LOW) 3343 goto done; 3344 } 3345 done: 3346 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3347 * after freeing the reference to old asconf ack if any. 3348 */ 3349 if (asconf_ack) { 3350 asoc->peer.addip_serial++; 3351 sctp_chunk_hold(asconf_ack); 3352 list_add_tail(&asconf_ack->transmitted_list, 3353 &asoc->asconf_ack_list); 3354 } 3355 3356 return asconf_ack; 3357 } 3358 3359 /* Process a asconf parameter that is successfully acked. */ 3360 static void sctp_asconf_param_success(struct sctp_association *asoc, 3361 struct sctp_addip_param *asconf_param) 3362 { 3363 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3364 union sctp_addr_param *addr_param; 3365 struct sctp_sockaddr_entry *saddr; 3366 struct sctp_transport *transport; 3367 union sctp_addr addr; 3368 struct sctp_af *af; 3369 3370 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3371 3372 /* We have checked the packet before, so we do not check again. */ 3373 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3374 if (!af->from_addr_param(&addr, addr_param, htons(bp->port), 0)) 3375 return; 3376 3377 switch (asconf_param->param_hdr.type) { 3378 case SCTP_PARAM_ADD_IP: 3379 /* This is always done in BH context with a socket lock 3380 * held, so the list can not change. 3381 */ 3382 local_bh_disable(); 3383 list_for_each_entry(saddr, &bp->address_list, list) { 3384 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3385 saddr->state = SCTP_ADDR_SRC; 3386 } 3387 local_bh_enable(); 3388 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3389 transports) { 3390 sctp_transport_dst_release(transport); 3391 } 3392 break; 3393 case SCTP_PARAM_DEL_IP: 3394 local_bh_disable(); 3395 sctp_del_bind_addr(bp, &addr); 3396 if (asoc->asconf_addr_del_pending != NULL && 3397 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3398 kfree(asoc->asconf_addr_del_pending); 3399 asoc->asconf_addr_del_pending = NULL; 3400 } 3401 local_bh_enable(); 3402 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3403 transports) { 3404 sctp_transport_dst_release(transport); 3405 } 3406 break; 3407 default: 3408 break; 3409 } 3410 } 3411 3412 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3413 * for the given asconf parameter. If there is no response for this parameter, 3414 * return the error code based on the third argument 'no_err'. 3415 * ADDIP 4.1 3416 * A7) If an error response is received for a TLV parameter, all TLVs with no 3417 * response before the failed TLV are considered successful if not reported. 3418 * All TLVs after the failed response are considered unsuccessful unless a 3419 * specific success indication is present for the parameter. 3420 */ 3421 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3422 struct sctp_addip_param *asconf_param, 3423 int no_err) 3424 { 3425 struct sctp_addip_param *asconf_ack_param; 3426 struct sctp_errhdr *err_param; 3427 int asconf_ack_len; 3428 __be16 err_code; 3429 int length; 3430 3431 if (no_err) 3432 err_code = SCTP_ERROR_NO_ERROR; 3433 else 3434 err_code = SCTP_ERROR_REQ_REFUSED; 3435 3436 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3437 sizeof(struct sctp_chunkhdr); 3438 3439 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3440 * the first asconf_ack parameter. 3441 */ 3442 length = sizeof(struct sctp_addiphdr); 3443 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data + 3444 length); 3445 asconf_ack_len -= length; 3446 3447 while (asconf_ack_len > 0) { 3448 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3449 switch (asconf_ack_param->param_hdr.type) { 3450 case SCTP_PARAM_SUCCESS_REPORT: 3451 return SCTP_ERROR_NO_ERROR; 3452 case SCTP_PARAM_ERR_CAUSE: 3453 length = sizeof(*asconf_ack_param); 3454 err_param = (void *)asconf_ack_param + length; 3455 return err_param->cause; 3456 default: 3457 return SCTP_ERROR_INV_PARAM; 3458 } 3459 } 3460 3461 length = ntohs(asconf_ack_param->param_hdr.length); 3462 asconf_ack_param = (void *)asconf_ack_param + SCTP_PAD4(length); 3463 asconf_ack_len -= SCTP_PAD4(length); 3464 } 3465 3466 return err_code; 3467 } 3468 3469 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3470 int sctp_process_asconf_ack(struct sctp_association *asoc, 3471 struct sctp_chunk *asconf_ack) 3472 { 3473 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3474 struct sctp_addip_param *asconf_param; 3475 __be16 err_code = SCTP_ERROR_NO_ERROR; 3476 union sctp_addr_param *addr_param; 3477 int asconf_len = asconf->skb->len; 3478 int all_param_pass = 0; 3479 int length = 0; 3480 int no_err = 1; 3481 int retval = 0; 3482 3483 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3484 * a pointer to address parameter. 3485 */ 3486 length = sizeof(struct sctp_addip_chunk); 3487 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3488 asconf_len -= length; 3489 3490 /* Skip the address parameter in the last asconf sent and store a 3491 * pointer to the first asconf parameter. 3492 */ 3493 length = ntohs(addr_param->p.length); 3494 asconf_param = (void *)addr_param + length; 3495 asconf_len -= length; 3496 3497 /* ADDIP 4.1 3498 * A8) If there is no response(s) to specific TLV parameter(s), and no 3499 * failures are indicated, then all request(s) are considered 3500 * successful. 3501 */ 3502 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr)) 3503 all_param_pass = 1; 3504 3505 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3506 while (asconf_len > 0) { 3507 if (all_param_pass) 3508 err_code = SCTP_ERROR_NO_ERROR; 3509 else { 3510 err_code = sctp_get_asconf_response(asconf_ack, 3511 asconf_param, 3512 no_err); 3513 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3514 no_err = 0; 3515 } 3516 3517 switch (err_code) { 3518 case SCTP_ERROR_NO_ERROR: 3519 sctp_asconf_param_success(asoc, asconf_param); 3520 break; 3521 3522 case SCTP_ERROR_RSRC_LOW: 3523 retval = 1; 3524 break; 3525 3526 case SCTP_ERROR_UNKNOWN_PARAM: 3527 /* Disable sending this type of asconf parameter in 3528 * future. 3529 */ 3530 asoc->peer.addip_disabled_mask |= 3531 asconf_param->param_hdr.type; 3532 break; 3533 3534 case SCTP_ERROR_REQ_REFUSED: 3535 case SCTP_ERROR_DEL_LAST_IP: 3536 case SCTP_ERROR_DEL_SRC_IP: 3537 default: 3538 break; 3539 } 3540 3541 /* Skip the processed asconf parameter and move to the next 3542 * one. 3543 */ 3544 length = ntohs(asconf_param->param_hdr.length); 3545 asconf_param = (void *)asconf_param + length; 3546 asconf_len -= length; 3547 } 3548 3549 if (no_err && asoc->src_out_of_asoc_ok) { 3550 asoc->src_out_of_asoc_ok = 0; 3551 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3552 } 3553 3554 /* Free the cached last sent asconf chunk. */ 3555 list_del_init(&asconf->transmitted_list); 3556 sctp_chunk_free(asconf); 3557 asoc->addip_last_asconf = NULL; 3558 3559 return retval; 3560 } 3561 3562 /* Make a FWD TSN chunk. */ 3563 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3564 __u32 new_cum_tsn, size_t nstreams, 3565 struct sctp_fwdtsn_skip *skiplist) 3566 { 3567 struct sctp_chunk *retval = NULL; 3568 struct sctp_fwdtsn_hdr ftsn_hdr; 3569 struct sctp_fwdtsn_skip skip; 3570 size_t hint; 3571 int i; 3572 3573 hint = (nstreams + 1) * sizeof(__u32); 3574 3575 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC); 3576 3577 if (!retval) 3578 return NULL; 3579 3580 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3581 retval->subh.fwdtsn_hdr = 3582 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3583 3584 for (i = 0; i < nstreams; i++) { 3585 skip.stream = skiplist[i].stream; 3586 skip.ssn = skiplist[i].ssn; 3587 sctp_addto_chunk(retval, sizeof(skip), &skip); 3588 } 3589 3590 return retval; 3591 } 3592 3593 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc, 3594 __u32 new_cum_tsn, size_t nstreams, 3595 struct sctp_ifwdtsn_skip *skiplist) 3596 { 3597 struct sctp_chunk *retval = NULL; 3598 struct sctp_ifwdtsn_hdr ftsn_hdr; 3599 size_t hint; 3600 3601 hint = (nstreams + 1) * sizeof(__u32); 3602 3603 retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint, 3604 GFP_ATOMIC); 3605 if (!retval) 3606 return NULL; 3607 3608 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3609 retval->subh.ifwdtsn_hdr = 3610 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3611 3612 sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist); 3613 3614 return retval; 3615 } 3616 3617 /* RE-CONFIG 3.1 (RE-CONFIG chunk) 3618 * 0 1 2 3 3619 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 3620 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3621 * | Type = 130 | Chunk Flags | Chunk Length | 3622 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3623 * \ \ 3624 * / Re-configuration Parameter / 3625 * \ \ 3626 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3627 * \ \ 3628 * / Re-configuration Parameter (optional) / 3629 * \ \ 3630 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3631 */ 3632 static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc, 3633 int length) 3634 { 3635 struct sctp_reconf_chunk *reconf; 3636 struct sctp_chunk *retval; 3637 3638 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length, 3639 GFP_ATOMIC); 3640 if (!retval) 3641 return NULL; 3642 3643 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr; 3644 retval->param_hdr.v = (u8 *)(reconf + 1); 3645 3646 return retval; 3647 } 3648 3649 /* RE-CONFIG 4.1 (STREAM OUT RESET) 3650 * 0 1 2 3 3651 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 3652 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3653 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N | 3654 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3655 * | Re-configuration Request Sequence Number | 3656 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3657 * | Re-configuration Response Sequence Number | 3658 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3659 * | Sender's Last Assigned TSN | 3660 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3661 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3662 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3663 * / ...... / 3664 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3665 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3666 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3667 * 3668 * RE-CONFIG 4.2 (STREAM IN RESET) 3669 * 0 1 2 3 3670 * 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 3671 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3672 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N | 3673 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3674 * | Re-configuration Request Sequence Number | 3675 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3676 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3677 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3678 * / ...... / 3679 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3680 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3681 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3682 */ 3683 struct sctp_chunk *sctp_make_strreset_req( 3684 const struct sctp_association *asoc, 3685 __u16 stream_num, __be16 *stream_list, 3686 bool out, bool in) 3687 { 3688 __u16 stream_len = stream_num * sizeof(__u16); 3689 struct sctp_strreset_outreq outreq; 3690 struct sctp_strreset_inreq inreq; 3691 struct sctp_chunk *retval; 3692 __u16 outlen, inlen; 3693 3694 outlen = (sizeof(outreq) + stream_len) * out; 3695 inlen = (sizeof(inreq) + stream_len) * in; 3696 3697 retval = sctp_make_reconf(asoc, SCTP_PAD4(outlen) + SCTP_PAD4(inlen)); 3698 if (!retval) 3699 return NULL; 3700 3701 if (outlen) { 3702 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST; 3703 outreq.param_hdr.length = htons(outlen); 3704 outreq.request_seq = htonl(asoc->strreset_outseq); 3705 outreq.response_seq = htonl(asoc->strreset_inseq - 1); 3706 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1); 3707 3708 sctp_addto_chunk(retval, sizeof(outreq), &outreq); 3709 3710 if (stream_len) 3711 sctp_addto_chunk(retval, stream_len, stream_list); 3712 } 3713 3714 if (inlen) { 3715 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST; 3716 inreq.param_hdr.length = htons(inlen); 3717 inreq.request_seq = htonl(asoc->strreset_outseq + out); 3718 3719 sctp_addto_chunk(retval, sizeof(inreq), &inreq); 3720 3721 if (stream_len) 3722 sctp_addto_chunk(retval, stream_len, stream_list); 3723 } 3724 3725 return retval; 3726 } 3727 3728 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL) 3729 * 0 1 2 3 3730 * 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 3731 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3732 * | Parameter Type = 15 | Parameter Length = 8 | 3733 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3734 * | Re-configuration Request Sequence Number | 3735 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3736 */ 3737 struct sctp_chunk *sctp_make_strreset_tsnreq( 3738 const struct sctp_association *asoc) 3739 { 3740 struct sctp_strreset_tsnreq tsnreq; 3741 __u16 length = sizeof(tsnreq); 3742 struct sctp_chunk *retval; 3743 3744 retval = sctp_make_reconf(asoc, length); 3745 if (!retval) 3746 return NULL; 3747 3748 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST; 3749 tsnreq.param_hdr.length = htons(length); 3750 tsnreq.request_seq = htonl(asoc->strreset_outseq); 3751 3752 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq); 3753 3754 return retval; 3755 } 3756 3757 /* RE-CONFIG 4.5/4.6 (ADD STREAM) 3758 * 0 1 2 3 3759 * 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 3760 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3761 * | Parameter Type = 17 | Parameter Length = 12 | 3762 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3763 * | Re-configuration Request Sequence Number | 3764 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3765 * | Number of new streams | Reserved | 3766 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3767 */ 3768 struct sctp_chunk *sctp_make_strreset_addstrm( 3769 const struct sctp_association *asoc, 3770 __u16 out, __u16 in) 3771 { 3772 struct sctp_strreset_addstrm addstrm; 3773 __u16 size = sizeof(addstrm); 3774 struct sctp_chunk *retval; 3775 3776 retval = sctp_make_reconf(asoc, (!!out + !!in) * size); 3777 if (!retval) 3778 return NULL; 3779 3780 if (out) { 3781 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS; 3782 addstrm.param_hdr.length = htons(size); 3783 addstrm.number_of_streams = htons(out); 3784 addstrm.request_seq = htonl(asoc->strreset_outseq); 3785 addstrm.reserved = 0; 3786 3787 sctp_addto_chunk(retval, size, &addstrm); 3788 } 3789 3790 if (in) { 3791 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS; 3792 addstrm.param_hdr.length = htons(size); 3793 addstrm.number_of_streams = htons(in); 3794 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out); 3795 addstrm.reserved = 0; 3796 3797 sctp_addto_chunk(retval, size, &addstrm); 3798 } 3799 3800 return retval; 3801 } 3802 3803 /* RE-CONFIG 4.4 (RESP) 3804 * 0 1 2 3 3805 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 3806 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3807 * | Parameter Type = 16 | Parameter Length | 3808 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3809 * | Re-configuration Response Sequence Number | 3810 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3811 * | Result | 3812 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3813 */ 3814 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc, 3815 __u32 result, __u32 sn) 3816 { 3817 struct sctp_strreset_resp resp; 3818 __u16 length = sizeof(resp); 3819 struct sctp_chunk *retval; 3820 3821 retval = sctp_make_reconf(asoc, length); 3822 if (!retval) 3823 return NULL; 3824 3825 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3826 resp.param_hdr.length = htons(length); 3827 resp.response_seq = htonl(sn); 3828 resp.result = htonl(result); 3829 3830 sctp_addto_chunk(retval, sizeof(resp), &resp); 3831 3832 return retval; 3833 } 3834 3835 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP) 3836 * 0 1 2 3 3837 * 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 3838 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3839 * | Parameter Type = 16 | Parameter Length | 3840 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3841 * | Re-configuration Response Sequence Number | 3842 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3843 * | Result | 3844 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3845 * | Sender's Next TSN (optional) | 3846 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3847 * | Receiver's Next TSN (optional) | 3848 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3849 */ 3850 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc, 3851 __u32 result, __u32 sn, 3852 __u32 sender_tsn, 3853 __u32 receiver_tsn) 3854 { 3855 struct sctp_strreset_resptsn tsnresp; 3856 __u16 length = sizeof(tsnresp); 3857 struct sctp_chunk *retval; 3858 3859 retval = sctp_make_reconf(asoc, length); 3860 if (!retval) 3861 return NULL; 3862 3863 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3864 tsnresp.param_hdr.length = htons(length); 3865 3866 tsnresp.response_seq = htonl(sn); 3867 tsnresp.result = htonl(result); 3868 tsnresp.senders_next_tsn = htonl(sender_tsn); 3869 tsnresp.receivers_next_tsn = htonl(receiver_tsn); 3870 3871 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp); 3872 3873 return retval; 3874 } 3875 3876 bool sctp_verify_reconf(const struct sctp_association *asoc, 3877 struct sctp_chunk *chunk, 3878 struct sctp_paramhdr **errp) 3879 { 3880 struct sctp_reconf_chunk *hdr; 3881 union sctp_params param; 3882 __be16 last = 0; 3883 __u16 cnt = 0; 3884 3885 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; 3886 sctp_walk_params(param, hdr) { 3887 __u16 length = ntohs(param.p->length); 3888 3889 *errp = param.p; 3890 if (cnt++ > 2) 3891 return false; 3892 switch (param.p->type) { 3893 case SCTP_PARAM_RESET_OUT_REQUEST: 3894 if (length < sizeof(struct sctp_strreset_outreq) || 3895 (last && last != SCTP_PARAM_RESET_RESPONSE && 3896 last != SCTP_PARAM_RESET_IN_REQUEST)) 3897 return false; 3898 break; 3899 case SCTP_PARAM_RESET_IN_REQUEST: 3900 if (length < sizeof(struct sctp_strreset_inreq) || 3901 (last && last != SCTP_PARAM_RESET_OUT_REQUEST)) 3902 return false; 3903 break; 3904 case SCTP_PARAM_RESET_RESPONSE: 3905 if ((length != sizeof(struct sctp_strreset_resp) && 3906 length != sizeof(struct sctp_strreset_resptsn)) || 3907 (last && last != SCTP_PARAM_RESET_RESPONSE && 3908 last != SCTP_PARAM_RESET_OUT_REQUEST)) 3909 return false; 3910 break; 3911 case SCTP_PARAM_RESET_TSN_REQUEST: 3912 if (length != 3913 sizeof(struct sctp_strreset_tsnreq) || last) 3914 return false; 3915 break; 3916 case SCTP_PARAM_RESET_ADD_IN_STREAMS: 3917 if (length != sizeof(struct sctp_strreset_addstrm) || 3918 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS)) 3919 return false; 3920 break; 3921 case SCTP_PARAM_RESET_ADD_OUT_STREAMS: 3922 if (length != sizeof(struct sctp_strreset_addstrm) || 3923 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS)) 3924 return false; 3925 break; 3926 default: 3927 return false; 3928 } 3929 3930 last = param.p->type; 3931 } 3932 3933 return true; 3934 } 3935