1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* SCTP kernel implementation 3 * (C) Copyright IBM Corp. 2001, 2004 4 * Copyright (c) 1999-2000 Cisco, Inc. 5 * Copyright (c) 1999-2001 Motorola, Inc. 6 * Copyright (c) 2001-2002 Intel Corp. 7 * 8 * This file is part of the SCTP kernel implementation 9 * 10 * These functions work with the state functions in sctp_sm_statefuns.c 11 * to implement the state operations. These functions implement the 12 * steps which require modifying existing data structures. 13 * 14 * Please send any bug reports or fixes you make to the 15 * email address(es): 16 * lksctp developers <linux-sctp@vger.kernel.org> 17 * 18 * Written or modified by: 19 * La Monte H.P. Yarroll <piggy@acm.org> 20 * Karl Knutson <karl@athena.chicago.il.us> 21 * C. Robin <chris@hundredacre.ac.uk> 22 * Jon Grimm <jgrimm@us.ibm.com> 23 * Xingang Guo <xingang.guo@intel.com> 24 * Dajiang Zhang <dajiang.zhang@nokia.com> 25 * Sridhar Samudrala <sri@us.ibm.com> 26 * Daisy Chang <daisyc@us.ibm.com> 27 * Ardelle Fan <ardelle.fan@intel.com> 28 * Kevin Gao <kevin.gao@intel.com> 29 */ 30 31 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 32 33 #include <crypto/utils.h> 34 #include <linux/types.h> 35 #include <linux/kernel.h> 36 #include <linux/ip.h> 37 #include <linux/ipv6.h> 38 #include <linux/net.h> 39 #include <linux/inet.h> 40 #include <linux/scatterlist.h> 41 #include <linux/slab.h> 42 #include <net/sock.h> 43 44 #include <linux/skbuff.h> 45 #include <linux/random.h> /* for get_random_bytes */ 46 #include <net/sctp/sctp.h> 47 #include <net/sctp/sm.h> 48 49 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 50 __u8 type, __u8 flags, int paylen, 51 gfp_t gfp); 52 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 53 __u8 flags, int paylen, gfp_t gfp); 54 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 55 __u8 type, __u8 flags, int paylen, 56 gfp_t gfp); 57 static struct sctp_cookie_param *sctp_pack_cookie( 58 const struct sctp_endpoint *ep, 59 const struct sctp_association *asoc, 60 const struct sctp_chunk *init_chunk, 61 int *cookie_len, 62 const __u8 *raw_addrs, int addrs_len); 63 static int sctp_process_param(struct sctp_association *asoc, 64 union sctp_params param, 65 const union sctp_addr *peer_addr, 66 gfp_t gfp); 67 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 68 const void *data); 69 70 /* Control chunk destructor */ 71 static void sctp_control_release_owner(struct sk_buff *skb) 72 { 73 struct sctp_chunk *chunk = skb_shinfo(skb)->destructor_arg; 74 75 if (chunk->shkey) { 76 struct sctp_shared_key *shkey = chunk->shkey; 77 struct sctp_association *asoc = chunk->asoc; 78 79 /* refcnt == 2 and !list_empty mean after this release, it's 80 * not being used anywhere, and it's time to notify userland 81 * that this shkey can be freed if it's been deactivated. 82 */ 83 if (shkey->deactivated && !list_empty(&shkey->key_list) && 84 refcount_read(&shkey->refcnt) == 2) { 85 struct sctp_ulpevent *ev; 86 87 ev = sctp_ulpevent_make_authkey(asoc, shkey->key_id, 88 SCTP_AUTH_FREE_KEY, 89 GFP_KERNEL); 90 if (ev) 91 asoc->stream.si->enqueue_event(&asoc->ulpq, ev); 92 } 93 sctp_auth_shkey_release(chunk->shkey); 94 } 95 } 96 97 static void sctp_control_set_owner_w(struct sctp_chunk *chunk) 98 { 99 struct sctp_association *asoc = chunk->asoc; 100 struct sk_buff *skb = chunk->skb; 101 102 /* TODO: properly account for control chunks. 103 * To do it right we'll need: 104 * 1) endpoint if association isn't known. 105 * 2) proper memory accounting. 106 * 107 * For now don't do anything for now. 108 */ 109 if (chunk->auth) { 110 chunk->shkey = asoc->shkey; 111 sctp_auth_shkey_hold(chunk->shkey); 112 } 113 skb->sk = asoc ? asoc->base.sk : NULL; 114 skb_shinfo(skb)->destructor_arg = chunk; 115 skb->destructor = sctp_control_release_owner; 116 } 117 118 /* RFC 2960 3.3.2 Initiation (INIT) (1) 119 * 120 * Note 2: The ECN capable field is reserved for future use of 121 * Explicit Congestion Notification. 122 */ 123 static const struct sctp_paramhdr ecap_param = { 124 SCTP_PARAM_ECN_CAPABLE, 125 cpu_to_be16(sizeof(struct sctp_paramhdr)), 126 }; 127 static const struct sctp_paramhdr prsctp_param = { 128 SCTP_PARAM_FWD_TSN_SUPPORT, 129 cpu_to_be16(sizeof(struct sctp_paramhdr)), 130 }; 131 132 /* A helper to initialize an op error inside a provided chunk, as most 133 * cause codes will be embedded inside an abort chunk. 134 */ 135 int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, 136 size_t paylen) 137 { 138 struct sctp_errhdr err; 139 __u16 len; 140 141 /* Cause code constants are now defined in network order. */ 142 err.cause = cause_code; 143 len = sizeof(err) + paylen; 144 err.length = htons(len); 145 146 if (skb_tailroom(chunk->skb) < len) 147 return -ENOSPC; 148 149 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(err), &err); 150 151 return 0; 152 } 153 154 /* 3.3.2 Initiation (INIT) (1) 155 * 156 * This chunk is used to initiate a SCTP association between two 157 * endpoints. The format of the INIT chunk is shown below: 158 * 159 * 0 1 2 3 160 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 161 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 162 * | Type = 1 | Chunk Flags | Chunk Length | 163 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 164 * | Initiate Tag | 165 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 166 * | Advertised Receiver Window Credit (a_rwnd) | 167 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 168 * | Number of Outbound Streams | Number of Inbound Streams | 169 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 170 * | Initial TSN | 171 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 172 * \ \ 173 * / Optional/Variable-Length Parameters / 174 * \ \ 175 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 176 * 177 * 178 * The INIT chunk contains the following parameters. Unless otherwise 179 * noted, each parameter MUST only be included once in the INIT chunk. 180 * 181 * Fixed Parameters Status 182 * ---------------------------------------------- 183 * Initiate Tag Mandatory 184 * Advertised Receiver Window Credit Mandatory 185 * Number of Outbound Streams Mandatory 186 * Number of Inbound Streams Mandatory 187 * Initial TSN Mandatory 188 * 189 * Variable Parameters Status Type Value 190 * ------------------------------------------------------------- 191 * IPv4 Address (Note 1) Optional 5 192 * IPv6 Address (Note 1) Optional 6 193 * Cookie Preservative Optional 9 194 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000) 195 * Host Name Address (Note 3) Optional 11 196 * Supported Address Types (Note 4) Optional 12 197 */ 198 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc, 199 const struct sctp_bind_addr *bp, 200 gfp_t gfp, int vparam_len) 201 { 202 struct sctp_supported_ext_param ext_param; 203 struct sctp_adaptation_ind_param aiparam; 204 struct sctp_paramhdr *auth_chunks = NULL; 205 struct sctp_paramhdr *auth_hmacs = NULL; 206 struct sctp_supported_addrs_param sat; 207 struct sctp_endpoint *ep = asoc->ep; 208 struct sctp_chunk *retval = NULL; 209 int num_types, addrs_len = 0; 210 struct sctp_inithdr init; 211 union sctp_params addrs; 212 struct sctp_sock *sp; 213 __u8 extensions[5]; 214 size_t chunksize; 215 __be16 types[2]; 216 int num_ext = 0; 217 218 /* RFC 2960 3.3.2 Initiation (INIT) (1) 219 * 220 * Note 1: The INIT chunks can contain multiple addresses that 221 * can be IPv4 and/or IPv6 in any combination. 222 */ 223 224 /* Convert the provided bind address list to raw format. */ 225 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp); 226 227 init.init_tag = htonl(asoc->c.my_vtag); 228 init.a_rwnd = htonl(asoc->rwnd); 229 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 230 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 231 init.initial_tsn = htonl(asoc->c.initial_tsn); 232 233 /* How many address types are needed? */ 234 sp = sctp_sk(asoc->base.sk); 235 num_types = sp->pf->supported_addrs(sp, types); 236 237 chunksize = sizeof(init) + addrs_len; 238 chunksize += SCTP_PAD4(SCTP_SAT_LEN(num_types)); 239 240 if (asoc->ep->ecn_enable) 241 chunksize += sizeof(ecap_param); 242 243 if (asoc->ep->prsctp_enable) 244 chunksize += sizeof(prsctp_param); 245 246 /* ADDIP: Section 4.2.7: 247 * An implementation supporting this extension [ADDIP] MUST list 248 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and 249 * INIT-ACK parameters. 250 */ 251 if (asoc->ep->asconf_enable) { 252 extensions[num_ext] = SCTP_CID_ASCONF; 253 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 254 num_ext += 2; 255 } 256 257 if (asoc->ep->reconf_enable) { 258 extensions[num_ext] = SCTP_CID_RECONF; 259 num_ext += 1; 260 } 261 262 if (sp->adaptation_ind) 263 chunksize += sizeof(aiparam); 264 265 if (asoc->ep->intl_enable) { 266 extensions[num_ext] = SCTP_CID_I_DATA; 267 num_ext += 1; 268 } 269 270 chunksize += vparam_len; 271 272 /* Account for AUTH related parameters */ 273 if (ep->auth_enable) { 274 /* Add random parameter length*/ 275 chunksize += sizeof(asoc->c.auth_random); 276 277 /* Add HMACS parameter length if any were defined */ 278 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; 279 if (auth_hmacs->length) 280 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 281 else 282 auth_hmacs = NULL; 283 284 /* Add CHUNKS parameter length */ 285 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; 286 if (auth_chunks->length) 287 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 288 else 289 auth_chunks = NULL; 290 291 extensions[num_ext] = SCTP_CID_AUTH; 292 num_ext += 1; 293 } 294 295 /* If we have any extensions to report, account for that */ 296 if (num_ext) 297 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext); 298 299 /* RFC 2960 3.3.2 Initiation (INIT) (1) 300 * 301 * Note 3: An INIT chunk MUST NOT contain more than one Host 302 * Name address parameter. Moreover, the sender of the INIT 303 * MUST NOT combine any other address types with the Host Name 304 * address in the INIT. The receiver of INIT MUST ignore any 305 * other address types if the Host Name address parameter is 306 * present in the received INIT chunk. 307 * 308 * PLEASE DO NOT FIXME [This version does not support Host Name.] 309 */ 310 311 retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp); 312 if (!retval) 313 goto nodata; 314 315 retval->subh.init_hdr = 316 sctp_addto_chunk(retval, sizeof(init), &init); 317 retval->param_hdr.v = 318 sctp_addto_chunk(retval, addrs_len, addrs.v); 319 320 /* RFC 2960 3.3.2 Initiation (INIT) (1) 321 * 322 * Note 4: This parameter, when present, specifies all the 323 * address types the sending endpoint can support. The absence 324 * of this parameter indicates that the sending endpoint can 325 * support any address type. 326 */ 327 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES; 328 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types)); 329 sctp_addto_chunk(retval, sizeof(sat), &sat); 330 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types); 331 332 if (asoc->ep->ecn_enable) 333 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 334 335 /* Add the supported extensions parameter. Be nice and add this 336 * fist before addiding the parameters for the extensions themselves 337 */ 338 if (num_ext) { 339 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 340 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext); 341 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); 342 sctp_addto_param(retval, num_ext, extensions); 343 } 344 345 if (asoc->ep->prsctp_enable) 346 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 347 348 if (sp->adaptation_ind) { 349 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 350 aiparam.param_hdr.length = htons(sizeof(aiparam)); 351 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 352 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 353 } 354 355 /* Add SCTP-AUTH chunks to the parameter list */ 356 if (ep->auth_enable) { 357 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random), 358 asoc->c.auth_random); 359 if (auth_hmacs) 360 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 361 auth_hmacs); 362 if (auth_chunks) 363 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 364 auth_chunks); 365 } 366 nodata: 367 kfree(addrs.v); 368 return retval; 369 } 370 371 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, 372 const struct sctp_chunk *chunk, 373 gfp_t gfp, int unkparam_len) 374 { 375 struct sctp_supported_ext_param ext_param; 376 struct sctp_adaptation_ind_param aiparam; 377 struct sctp_paramhdr *auth_chunks = NULL; 378 struct sctp_paramhdr *auth_random = NULL; 379 struct sctp_paramhdr *auth_hmacs = NULL; 380 struct sctp_chunk *retval = NULL; 381 struct sctp_cookie_param *cookie; 382 struct sctp_inithdr initack; 383 union sctp_params addrs; 384 struct sctp_sock *sp; 385 __u8 extensions[5]; 386 size_t chunksize; 387 int num_ext = 0; 388 int cookie_len; 389 int addrs_len; 390 391 /* Note: there may be no addresses to embed. */ 392 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp); 393 394 initack.init_tag = htonl(asoc->c.my_vtag); 395 initack.a_rwnd = htonl(asoc->rwnd); 396 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 397 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 398 initack.initial_tsn = htonl(asoc->c.initial_tsn); 399 400 /* FIXME: We really ought to build the cookie right 401 * into the packet instead of allocating more fresh memory. 402 */ 403 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len, 404 addrs.v, addrs_len); 405 if (!cookie) 406 goto nomem_cookie; 407 408 /* Calculate the total size of allocation, include the reserved 409 * space for reporting unknown parameters if it is specified. 410 */ 411 sp = sctp_sk(asoc->base.sk); 412 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len; 413 414 /* Tell peer that we'll do ECN only if peer advertised such cap. */ 415 if (asoc->peer.ecn_capable) 416 chunksize += sizeof(ecap_param); 417 418 if (asoc->peer.prsctp_capable) 419 chunksize += sizeof(prsctp_param); 420 421 if (asoc->peer.asconf_capable) { 422 extensions[num_ext] = SCTP_CID_ASCONF; 423 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 424 num_ext += 2; 425 } 426 427 if (asoc->peer.reconf_capable) { 428 extensions[num_ext] = SCTP_CID_RECONF; 429 num_ext += 1; 430 } 431 432 if (sp->adaptation_ind) 433 chunksize += sizeof(aiparam); 434 435 if (asoc->peer.intl_capable) { 436 extensions[num_ext] = SCTP_CID_I_DATA; 437 num_ext += 1; 438 } 439 440 if (asoc->peer.auth_capable) { 441 auth_random = (struct sctp_paramhdr *)asoc->c.auth_random; 442 chunksize += ntohs(auth_random->length); 443 444 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs; 445 if (auth_hmacs->length) 446 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length)); 447 else 448 auth_hmacs = NULL; 449 450 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks; 451 if (auth_chunks->length) 452 chunksize += SCTP_PAD4(ntohs(auth_chunks->length)); 453 else 454 auth_chunks = NULL; 455 456 extensions[num_ext] = SCTP_CID_AUTH; 457 num_ext += 1; 458 } 459 460 if (num_ext) 461 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext); 462 463 /* Now allocate and fill out the chunk. */ 464 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp); 465 if (!retval) 466 goto nomem_chunk; 467 468 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 469 * 470 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 471 * HEARTBEAT ACK, * etc.) to the same destination transport 472 * address from which it received the DATA or control chunk 473 * to which it is replying. 474 * 475 * [INIT ACK back to where the INIT came from.] 476 */ 477 if (chunk->transport) 478 retval->transport = 479 sctp_assoc_lookup_paddr(asoc, 480 &chunk->transport->ipaddr); 481 482 retval->subh.init_hdr = 483 sctp_addto_chunk(retval, sizeof(initack), &initack); 484 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); 485 sctp_addto_chunk(retval, cookie_len, cookie); 486 if (asoc->peer.ecn_capable) 487 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 488 if (num_ext) { 489 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 490 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext); 491 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param); 492 sctp_addto_param(retval, num_ext, extensions); 493 } 494 if (asoc->peer.prsctp_capable) 495 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 496 497 if (sp->adaptation_ind) { 498 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 499 aiparam.param_hdr.length = htons(sizeof(aiparam)); 500 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 501 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 502 } 503 504 if (asoc->peer.auth_capable) { 505 sctp_addto_chunk(retval, ntohs(auth_random->length), 506 auth_random); 507 if (auth_hmacs) 508 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 509 auth_hmacs); 510 if (auth_chunks) 511 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 512 auth_chunks); 513 } 514 515 /* We need to remove the const qualifier at this point. */ 516 retval->asoc = (struct sctp_association *) asoc; 517 518 nomem_chunk: 519 kfree(cookie); 520 nomem_cookie: 521 kfree(addrs.v); 522 return retval; 523 } 524 525 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10): 526 * 527 * This chunk is used only during the initialization of an association. 528 * It is sent by the initiator of an association to its peer to complete 529 * the initialization process. This chunk MUST precede any DATA chunk 530 * sent within the association, but MAY be bundled with one or more DATA 531 * chunks in the same packet. 532 * 533 * 0 1 2 3 534 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 535 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 536 * | Type = 10 |Chunk Flags | Length | 537 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 538 * / Cookie / 539 * \ \ 540 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 541 * 542 * Chunk Flags: 8 bit 543 * 544 * Set to zero on transmit and ignored on receipt. 545 * 546 * Length: 16 bits (unsigned integer) 547 * 548 * Set to the size of the chunk in bytes, including the 4 bytes of 549 * the chunk header and the size of the Cookie. 550 * 551 * Cookie: variable size 552 * 553 * This field must contain the exact cookie received in the 554 * State Cookie parameter from the previous INIT ACK. 555 * 556 * An implementation SHOULD make the cookie as small as possible 557 * to insure interoperability. 558 */ 559 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, 560 const struct sctp_chunk *chunk) 561 { 562 struct sctp_chunk *retval; 563 int cookie_len; 564 void *cookie; 565 566 cookie = asoc->peer.cookie; 567 cookie_len = asoc->peer.cookie_len; 568 569 /* Build a cookie echo chunk. */ 570 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0, 571 cookie_len, GFP_ATOMIC); 572 if (!retval) 573 goto nodata; 574 retval->subh.cookie_hdr = 575 sctp_addto_chunk(retval, cookie_len, cookie); 576 577 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 578 * 579 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 580 * HEARTBEAT ACK, * etc.) to the same destination transport 581 * address from which it * received the DATA or control chunk 582 * to which it is replying. 583 * 584 * [COOKIE ECHO back to where the INIT ACK came from.] 585 */ 586 if (chunk) 587 retval->transport = chunk->transport; 588 589 nodata: 590 return retval; 591 } 592 593 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11): 594 * 595 * This chunk is used only during the initialization of an 596 * association. It is used to acknowledge the receipt of a COOKIE 597 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent 598 * within the association, but MAY be bundled with one or more DATA 599 * chunks or SACK chunk in the same SCTP packet. 600 * 601 * 0 1 2 3 602 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 603 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 604 * | Type = 11 |Chunk Flags | Length = 4 | 605 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 606 * 607 * Chunk Flags: 8 bits 608 * 609 * Set to zero on transmit and ignored on receipt. 610 */ 611 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, 612 const struct sctp_chunk *chunk) 613 { 614 struct sctp_chunk *retval; 615 616 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC); 617 618 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 619 * 620 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 621 * HEARTBEAT ACK, * etc.) to the same destination transport 622 * address from which it * received the DATA or control chunk 623 * to which it is replying. 624 * 625 * [COOKIE ACK back to where the COOKIE ECHO came from.] 626 */ 627 if (retval && chunk && chunk->transport) 628 retval->transport = 629 sctp_assoc_lookup_paddr(asoc, 630 &chunk->transport->ipaddr); 631 632 return retval; 633 } 634 635 /* 636 * Appendix A: Explicit Congestion Notification: 637 * CWR: 638 * 639 * RFC 2481 details a specific bit for a sender to send in the header of 640 * its next outbound TCP segment to indicate to its peer that it has 641 * reduced its congestion window. This is termed the CWR bit. For 642 * SCTP the same indication is made by including the CWR chunk. 643 * This chunk contains one data element, i.e. the TSN number that 644 * was sent in the ECNE chunk. This element represents the lowest 645 * TSN number in the datagram that was originally marked with the 646 * CE bit. 647 * 648 * 0 1 2 3 649 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 650 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 651 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 | 652 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 653 * | Lowest TSN Number | 654 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 655 * 656 * Note: The CWR is considered a Control chunk. 657 */ 658 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, 659 const __u32 lowest_tsn, 660 const struct sctp_chunk *chunk) 661 { 662 struct sctp_chunk *retval; 663 struct sctp_cwrhdr cwr; 664 665 cwr.lowest_tsn = htonl(lowest_tsn); 666 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0, 667 sizeof(cwr), GFP_ATOMIC); 668 669 if (!retval) 670 goto nodata; 671 672 retval->subh.ecn_cwr_hdr = 673 sctp_addto_chunk(retval, sizeof(cwr), &cwr); 674 675 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 676 * 677 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 678 * HEARTBEAT ACK, * etc.) to the same destination transport 679 * address from which it * received the DATA or control chunk 680 * to which it is replying. 681 * 682 * [Report a reduced congestion window back to where the ECNE 683 * came from.] 684 */ 685 if (chunk) 686 retval->transport = chunk->transport; 687 688 nodata: 689 return retval; 690 } 691 692 /* Make an ECNE chunk. This is a congestion experienced report. */ 693 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, 694 const __u32 lowest_tsn) 695 { 696 struct sctp_chunk *retval; 697 struct sctp_ecnehdr ecne; 698 699 ecne.lowest_tsn = htonl(lowest_tsn); 700 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0, 701 sizeof(ecne), GFP_ATOMIC); 702 if (!retval) 703 goto nodata; 704 retval->subh.ecne_hdr = 705 sctp_addto_chunk(retval, sizeof(ecne), &ecne); 706 707 nodata: 708 return retval; 709 } 710 711 /* Make a DATA chunk for the given association from the provided 712 * parameters. However, do not populate the data payload. 713 */ 714 struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc, 715 const struct sctp_sndrcvinfo *sinfo, 716 int len, __u8 flags, gfp_t gfp) 717 { 718 struct sctp_chunk *retval; 719 struct sctp_datahdr dp; 720 721 /* We assign the TSN as LATE as possible, not here when 722 * creating the chunk. 723 */ 724 memset(&dp, 0, sizeof(dp)); 725 dp.ppid = sinfo->sinfo_ppid; 726 dp.stream = htons(sinfo->sinfo_stream); 727 728 /* Set the flags for an unordered send. */ 729 if (sinfo->sinfo_flags & SCTP_UNORDERED) 730 flags |= SCTP_DATA_UNORDERED; 731 732 retval = sctp_make_data(asoc, flags, sizeof(dp) + len, gfp); 733 if (!retval) 734 return NULL; 735 736 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp); 737 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo)); 738 739 return retval; 740 } 741 742 /* Create a selective ackowledgement (SACK) for the given 743 * association. This reports on which TSN's we've seen to date, 744 * including duplicates and gaps. 745 */ 746 struct sctp_chunk *sctp_make_sack(struct sctp_association *asoc) 747 { 748 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; 749 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; 750 __u16 num_gabs, num_dup_tsns; 751 struct sctp_transport *trans; 752 struct sctp_chunk *retval; 753 struct sctp_sackhdr sack; 754 __u32 ctsn; 755 int len; 756 757 memset(gabs, 0, sizeof(gabs)); 758 ctsn = sctp_tsnmap_get_ctsn(map); 759 760 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn); 761 762 /* How much room is needed in the chunk? */ 763 num_gabs = sctp_tsnmap_num_gabs(map, gabs); 764 num_dup_tsns = sctp_tsnmap_num_dups(map); 765 766 /* Initialize the SACK header. */ 767 sack.cum_tsn_ack = htonl(ctsn); 768 sack.a_rwnd = htonl(asoc->a_rwnd); 769 sack.num_gap_ack_blocks = htons(num_gabs); 770 sack.num_dup_tsns = htons(num_dup_tsns); 771 772 len = sizeof(sack) 773 + sizeof(struct sctp_gap_ack_block) * num_gabs 774 + sizeof(__u32) * num_dup_tsns; 775 776 /* Create the chunk. */ 777 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC); 778 if (!retval) 779 goto nodata; 780 781 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 782 * 783 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 784 * HEARTBEAT ACK, etc.) to the same destination transport 785 * address from which it received the DATA or control chunk to 786 * which it is replying. This rule should also be followed if 787 * the endpoint is bundling DATA chunks together with the 788 * reply chunk. 789 * 790 * However, when acknowledging multiple DATA chunks received 791 * in packets from different source addresses in a single 792 * SACK, the SACK chunk may be transmitted to one of the 793 * destination transport addresses from which the DATA or 794 * control chunks being acknowledged were received. 795 * 796 * [BUG: We do not implement the following paragraph. 797 * Perhaps we should remember the last transport we used for a 798 * SACK and avoid that (if possible) if we have seen any 799 * duplicates. --piggy] 800 * 801 * When a receiver of a duplicate DATA chunk sends a SACK to a 802 * multi- homed endpoint it MAY be beneficial to vary the 803 * destination address and not use the source address of the 804 * DATA chunk. The reason being that receiving a duplicate 805 * from a multi-homed endpoint might indicate that the return 806 * path (as specified in the source address of the DATA chunk) 807 * for the SACK is broken. 808 * 809 * [Send to the address from which we last received a DATA chunk.] 810 */ 811 retval->transport = asoc->peer.last_data_from; 812 813 retval->subh.sack_hdr = 814 sctp_addto_chunk(retval, sizeof(sack), &sack); 815 816 /* Add the gap ack block information. */ 817 if (num_gabs) 818 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, 819 gabs); 820 821 /* Add the duplicate TSN information. */ 822 if (num_dup_tsns) { 823 asoc->stats.idupchunks += num_dup_tsns; 824 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, 825 sctp_tsnmap_get_dups(map)); 826 } 827 /* Once we have a sack generated, check to see what our sack 828 * generation is, if its 0, reset the transports to 0, and reset 829 * the association generation to 1 830 * 831 * The idea is that zero is never used as a valid generation for the 832 * association so no transport will match after a wrap event like this, 833 * Until the next sack 834 */ 835 if (++asoc->peer.sack_generation == 0) { 836 list_for_each_entry(trans, &asoc->peer.transport_addr_list, 837 transports) 838 trans->sack_generation = 0; 839 asoc->peer.sack_generation = 1; 840 } 841 nodata: 842 return retval; 843 } 844 845 /* Make a SHUTDOWN chunk. */ 846 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 847 const struct sctp_chunk *chunk) 848 { 849 struct sctp_shutdownhdr shut; 850 struct sctp_chunk *retval; 851 __u32 ctsn; 852 853 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 854 shut.cum_tsn_ack = htonl(ctsn); 855 856 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0, 857 sizeof(shut), GFP_ATOMIC); 858 if (!retval) 859 goto nodata; 860 861 retval->subh.shutdown_hdr = 862 sctp_addto_chunk(retval, sizeof(shut), &shut); 863 864 if (chunk) 865 retval->transport = chunk->transport; 866 nodata: 867 return retval; 868 } 869 870 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 871 const struct sctp_chunk *chunk) 872 { 873 struct sctp_chunk *retval; 874 875 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0, 876 GFP_ATOMIC); 877 878 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 879 * 880 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 881 * HEARTBEAT ACK, * etc.) to the same destination transport 882 * address from which it * received the DATA or control chunk 883 * to which it is replying. 884 * 885 * [ACK back to where the SHUTDOWN came from.] 886 */ 887 if (retval && chunk) 888 retval->transport = chunk->transport; 889 890 return retval; 891 } 892 893 struct sctp_chunk *sctp_make_shutdown_complete( 894 const struct sctp_association *asoc, 895 const struct sctp_chunk *chunk) 896 { 897 struct sctp_chunk *retval; 898 __u8 flags = 0; 899 900 /* Set the T-bit if we have no association (vtag will be 901 * reflected) 902 */ 903 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; 904 905 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 906 0, GFP_ATOMIC); 907 908 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 909 * 910 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 911 * HEARTBEAT ACK, * etc.) to the same destination transport 912 * address from which it * received the DATA or control chunk 913 * to which it is replying. 914 * 915 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK 916 * came from.] 917 */ 918 if (retval && chunk) 919 retval->transport = chunk->transport; 920 921 return retval; 922 } 923 924 /* Create an ABORT. Note that we set the T bit if we have no 925 * association, except when responding to an INIT (sctpimpguide 2.41). 926 */ 927 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 928 const struct sctp_chunk *chunk, 929 const size_t hint) 930 { 931 struct sctp_chunk *retval; 932 __u8 flags = 0; 933 934 /* Set the T-bit if we have no association and 'chunk' is not 935 * an INIT (vtag will be reflected). 936 */ 937 if (!asoc) { 938 if (chunk && chunk->chunk_hdr && 939 chunk->chunk_hdr->type == SCTP_CID_INIT) 940 flags = 0; 941 else 942 flags = SCTP_CHUNK_FLAG_T; 943 } 944 945 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint, 946 GFP_ATOMIC); 947 948 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 949 * 950 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 951 * HEARTBEAT ACK, * etc.) to the same destination transport 952 * address from which it * received the DATA or control chunk 953 * to which it is replying. 954 * 955 * [ABORT back to where the offender came from.] 956 */ 957 if (retval && chunk) 958 retval->transport = chunk->transport; 959 960 return retval; 961 } 962 963 /* Helper to create ABORT with a NO_USER_DATA error. */ 964 struct sctp_chunk *sctp_make_abort_no_data( 965 const struct sctp_association *asoc, 966 const struct sctp_chunk *chunk, 967 __u32 tsn) 968 { 969 struct sctp_chunk *retval; 970 __be32 payload; 971 972 retval = sctp_make_abort(asoc, chunk, 973 sizeof(struct sctp_errhdr) + sizeof(tsn)); 974 975 if (!retval) 976 goto no_mem; 977 978 /* Put the tsn back into network byte order. */ 979 payload = htonl(tsn); 980 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload)); 981 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload); 982 983 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 984 * 985 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 986 * HEARTBEAT ACK, * etc.) to the same destination transport 987 * address from which it * received the DATA or control chunk 988 * to which it is replying. 989 * 990 * [ABORT back to where the offender came from.] 991 */ 992 if (chunk) 993 retval->transport = chunk->transport; 994 995 no_mem: 996 return retval; 997 } 998 999 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ 1000 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 1001 struct msghdr *msg, 1002 size_t paylen) 1003 { 1004 struct sctp_chunk *retval; 1005 void *payload = NULL; 1006 int err; 1007 1008 retval = sctp_make_abort(asoc, NULL, 1009 sizeof(struct sctp_errhdr) + paylen); 1010 if (!retval) 1011 goto err_chunk; 1012 1013 if (paylen) { 1014 /* Put the msg_iov together into payload. */ 1015 payload = kmalloc(paylen, GFP_KERNEL); 1016 if (!payload) 1017 goto err_payload; 1018 1019 err = memcpy_from_msg(payload, msg, paylen); 1020 if (err < 0) 1021 goto err_copy; 1022 } 1023 1024 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); 1025 sctp_addto_chunk(retval, paylen, payload); 1026 1027 if (paylen) 1028 kfree(payload); 1029 1030 return retval; 1031 1032 err_copy: 1033 kfree(payload); 1034 err_payload: 1035 sctp_chunk_free(retval); 1036 retval = NULL; 1037 err_chunk: 1038 return retval; 1039 } 1040 1041 /* Append bytes to the end of a parameter. Will panic if chunk is not big 1042 * enough. 1043 */ 1044 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 1045 const void *data) 1046 { 1047 int chunklen = ntohs(chunk->chunk_hdr->length); 1048 void *target; 1049 1050 target = skb_put(chunk->skb, len); 1051 1052 if (data) 1053 memcpy(target, data, len); 1054 else 1055 memset(target, 0, len); 1056 1057 /* Adjust the chunk length field. */ 1058 chunk->chunk_hdr->length = htons(chunklen + len); 1059 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1060 1061 return target; 1062 } 1063 1064 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ 1065 struct sctp_chunk *sctp_make_abort_violation( 1066 const struct sctp_association *asoc, 1067 const struct sctp_chunk *chunk, 1068 const __u8 *payload, 1069 const size_t paylen) 1070 { 1071 struct sctp_chunk *retval; 1072 struct sctp_paramhdr phdr; 1073 1074 retval = sctp_make_abort(asoc, chunk, sizeof(struct sctp_errhdr) + 1075 paylen + sizeof(phdr)); 1076 if (!retval) 1077 goto end; 1078 1079 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen + 1080 sizeof(phdr)); 1081 1082 phdr.type = htons(chunk->chunk_hdr->type); 1083 phdr.length = chunk->chunk_hdr->length; 1084 sctp_addto_chunk(retval, paylen, payload); 1085 sctp_addto_param(retval, sizeof(phdr), &phdr); 1086 1087 end: 1088 return retval; 1089 } 1090 1091 struct sctp_chunk *sctp_make_violation_paramlen( 1092 const struct sctp_association *asoc, 1093 const struct sctp_chunk *chunk, 1094 struct sctp_paramhdr *param) 1095 { 1096 static const char error[] = "The following parameter had invalid length:"; 1097 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr) + 1098 sizeof(*param); 1099 struct sctp_chunk *retval; 1100 1101 retval = sctp_make_abort(asoc, chunk, payload_len); 1102 if (!retval) 1103 goto nodata; 1104 1105 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, 1106 sizeof(error) + sizeof(*param)); 1107 sctp_addto_chunk(retval, sizeof(error), error); 1108 sctp_addto_param(retval, sizeof(*param), param); 1109 1110 nodata: 1111 return retval; 1112 } 1113 1114 struct sctp_chunk *sctp_make_violation_max_retrans( 1115 const struct sctp_association *asoc, 1116 const struct sctp_chunk *chunk) 1117 { 1118 static const char error[] = "Association exceeded its max_retrans count"; 1119 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr); 1120 struct sctp_chunk *retval; 1121 1122 retval = sctp_make_abort(asoc, chunk, payload_len); 1123 if (!retval) 1124 goto nodata; 1125 1126 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error)); 1127 sctp_addto_chunk(retval, sizeof(error), error); 1128 1129 nodata: 1130 return retval; 1131 } 1132 1133 struct sctp_chunk *sctp_make_new_encap_port(const struct sctp_association *asoc, 1134 const struct sctp_chunk *chunk) 1135 { 1136 struct sctp_new_encap_port_hdr nep; 1137 struct sctp_chunk *retval; 1138 1139 retval = sctp_make_abort(asoc, chunk, 1140 sizeof(struct sctp_errhdr) + sizeof(nep)); 1141 if (!retval) 1142 goto nodata; 1143 1144 sctp_init_cause(retval, SCTP_ERROR_NEW_ENCAP_PORT, sizeof(nep)); 1145 nep.cur_port = SCTP_INPUT_CB(chunk->skb)->encap_port; 1146 nep.new_port = chunk->transport->encap_port; 1147 sctp_addto_chunk(retval, sizeof(nep), &nep); 1148 1149 nodata: 1150 return retval; 1151 } 1152 1153 /* Make a HEARTBEAT chunk. */ 1154 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1155 const struct sctp_transport *transport, 1156 __u32 probe_size) 1157 { 1158 struct sctp_sender_hb_info hbinfo = {}; 1159 struct sctp_chunk *retval; 1160 1161 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, 1162 sizeof(hbinfo), GFP_ATOMIC); 1163 1164 if (!retval) 1165 goto nodata; 1166 1167 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; 1168 hbinfo.param_hdr.length = htons(sizeof(hbinfo)); 1169 hbinfo.daddr = transport->ipaddr; 1170 hbinfo.sent_at = jiffies; 1171 hbinfo.hb_nonce = transport->hb_nonce; 1172 hbinfo.probe_size = probe_size; 1173 1174 /* Cast away the 'const', as this is just telling the chunk 1175 * what transport it belongs to. 1176 */ 1177 retval->transport = (struct sctp_transport *) transport; 1178 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo), 1179 &hbinfo); 1180 retval->pmtu_probe = !!probe_size; 1181 1182 nodata: 1183 return retval; 1184 } 1185 1186 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1187 const struct sctp_chunk *chunk, 1188 const void *payload, 1189 const size_t paylen) 1190 { 1191 struct sctp_chunk *retval; 1192 1193 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen, 1194 GFP_ATOMIC); 1195 if (!retval) 1196 goto nodata; 1197 1198 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1199 1200 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1201 * 1202 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1203 * HEARTBEAT ACK, * etc.) to the same destination transport 1204 * address from which it * received the DATA or control chunk 1205 * to which it is replying. 1206 * 1207 * [HBACK back to where the HEARTBEAT came from.] 1208 */ 1209 if (chunk) 1210 retval->transport = chunk->transport; 1211 1212 nodata: 1213 return retval; 1214 } 1215 1216 /* RFC4820 3. Padding Chunk (PAD) 1217 * 0 1 2 3 1218 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 1219 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1220 * | Type = 0x84 | Flags=0 | Length | 1221 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1222 * | | 1223 * \ Padding Data / 1224 * / \ 1225 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1226 */ 1227 struct sctp_chunk *sctp_make_pad(const struct sctp_association *asoc, int len) 1228 { 1229 struct sctp_chunk *retval; 1230 1231 retval = sctp_make_control(asoc, SCTP_CID_PAD, 0, len, GFP_ATOMIC); 1232 if (!retval) 1233 return NULL; 1234 1235 skb_put_zero(retval->skb, len); 1236 retval->chunk_hdr->length = htons(ntohs(retval->chunk_hdr->length) + len); 1237 retval->chunk_end = skb_tail_pointer(retval->skb); 1238 1239 return retval; 1240 } 1241 1242 /* Create an Operation Error chunk with the specified space reserved. 1243 * This routine can be used for containing multiple causes in the chunk. 1244 */ 1245 static struct sctp_chunk *sctp_make_op_error_space( 1246 const struct sctp_association *asoc, 1247 const struct sctp_chunk *chunk, 1248 size_t size) 1249 { 1250 struct sctp_chunk *retval; 1251 1252 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0, 1253 sizeof(struct sctp_errhdr) + size, 1254 GFP_ATOMIC); 1255 if (!retval) 1256 goto nodata; 1257 1258 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1259 * 1260 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1261 * HEARTBEAT ACK, etc.) to the same destination transport 1262 * address from which it received the DATA or control chunk 1263 * to which it is replying. 1264 * 1265 */ 1266 if (chunk) 1267 retval->transport = chunk->transport; 1268 1269 nodata: 1270 return retval; 1271 } 1272 1273 /* Create an Operation Error chunk of a fixed size, specifically, 1274 * min(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) - overheads. 1275 * This is a helper function to allocate an error chunk for those 1276 * invalid parameter codes in which we may not want to report all the 1277 * errors, if the incoming chunk is large. If it can't fit in a single 1278 * packet, we ignore it. 1279 */ 1280 static inline struct sctp_chunk *sctp_make_op_error_limited( 1281 const struct sctp_association *asoc, 1282 const struct sctp_chunk *chunk) 1283 { 1284 size_t size = SCTP_DEFAULT_MAXSEGMENT; 1285 struct sctp_sock *sp = NULL; 1286 1287 if (asoc) { 1288 size = min_t(size_t, size, asoc->pathmtu); 1289 sp = sctp_sk(asoc->base.sk); 1290 } 1291 1292 size = sctp_mtu_payload(sp, size, sizeof(struct sctp_errhdr)); 1293 1294 return sctp_make_op_error_space(asoc, chunk, size); 1295 } 1296 1297 /* Create an Operation Error chunk. */ 1298 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1299 const struct sctp_chunk *chunk, 1300 __be16 cause_code, const void *payload, 1301 size_t paylen, size_t reserve_tail) 1302 { 1303 struct sctp_chunk *retval; 1304 1305 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); 1306 if (!retval) 1307 goto nodata; 1308 1309 sctp_init_cause(retval, cause_code, paylen + reserve_tail); 1310 sctp_addto_chunk(retval, paylen, payload); 1311 if (reserve_tail) 1312 sctp_addto_param(retval, reserve_tail, NULL); 1313 1314 nodata: 1315 return retval; 1316 } 1317 1318 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc, 1319 __u16 key_id) 1320 { 1321 struct sctp_authhdr auth_hdr; 1322 const struct sctp_hmac *hmac_desc; 1323 struct sctp_chunk *retval; 1324 1325 /* Get the first hmac that the peer told us to use */ 1326 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1327 if (unlikely(!hmac_desc)) 1328 return NULL; 1329 1330 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0, 1331 hmac_desc->hmac_len + sizeof(auth_hdr), 1332 GFP_ATOMIC); 1333 if (!retval) 1334 return NULL; 1335 1336 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1337 auth_hdr.shkey_id = htons(key_id); 1338 1339 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr), 1340 &auth_hdr); 1341 1342 skb_put_zero(retval->skb, hmac_desc->hmac_len); 1343 1344 /* Adjust the chunk header to include the empty MAC */ 1345 retval->chunk_hdr->length = 1346 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1347 retval->chunk_end = skb_tail_pointer(retval->skb); 1348 1349 return retval; 1350 } 1351 1352 1353 /******************************************************************** 1354 * 2nd Level Abstractions 1355 ********************************************************************/ 1356 1357 /* Turn an skb into a chunk. 1358 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1359 * 1360 * sctpimpguide-05.txt Section 2.8.2 1361 * M1) Each time a new DATA chunk is transmitted 1362 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1363 * 'TSN.Missing.Report' count will be used to determine missing chunks 1364 * and when to fast retransmit. 1365 * 1366 */ 1367 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1368 const struct sctp_association *asoc, 1369 struct sock *sk, gfp_t gfp) 1370 { 1371 struct sctp_chunk *retval; 1372 1373 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp); 1374 1375 if (!retval) 1376 goto nodata; 1377 if (!sk) 1378 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb); 1379 1380 INIT_LIST_HEAD(&retval->list); 1381 retval->skb = skb; 1382 retval->asoc = (struct sctp_association *)asoc; 1383 retval->singleton = 1; 1384 1385 retval->fast_retransmit = SCTP_CAN_FRTX; 1386 1387 /* Polish the bead hole. */ 1388 INIT_LIST_HEAD(&retval->transmitted_list); 1389 INIT_LIST_HEAD(&retval->frag_list); 1390 SCTP_DBG_OBJCNT_INC(chunk); 1391 refcount_set(&retval->refcnt, 1); 1392 1393 nodata: 1394 return retval; 1395 } 1396 1397 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1398 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1399 union sctp_addr *dest) 1400 { 1401 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1402 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1403 } 1404 1405 /* Extract the source address from a chunk. */ 1406 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1407 { 1408 /* If we have a known transport, use that. */ 1409 if (chunk->transport) { 1410 return &chunk->transport->ipaddr; 1411 } else { 1412 /* Otherwise, extract it from the IP header. */ 1413 return &chunk->source; 1414 } 1415 } 1416 1417 /* Create a new chunk, setting the type and flags headers from the 1418 * arguments, reserving enough space for a 'paylen' byte payload. 1419 */ 1420 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 1421 __u8 type, __u8 flags, int paylen, 1422 gfp_t gfp) 1423 { 1424 struct sctp_chunkhdr *chunk_hdr; 1425 struct sctp_chunk *retval; 1426 struct sk_buff *skb; 1427 struct sock *sk; 1428 int chunklen; 1429 1430 chunklen = SCTP_PAD4(sizeof(*chunk_hdr) + paylen); 1431 if (chunklen > SCTP_MAX_CHUNK_LEN) 1432 goto nodata; 1433 1434 /* No need to allocate LL here, as this is only a chunk. */ 1435 skb = alloc_skb(chunklen, gfp); 1436 if (!skb) 1437 goto nodata; 1438 1439 /* Make room for the chunk header. */ 1440 chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr)); 1441 chunk_hdr->type = type; 1442 chunk_hdr->flags = flags; 1443 chunk_hdr->length = htons(sizeof(*chunk_hdr)); 1444 1445 sk = asoc ? asoc->base.sk : NULL; 1446 retval = sctp_chunkify(skb, asoc, sk, gfp); 1447 if (!retval) { 1448 kfree_skb(skb); 1449 goto nodata; 1450 } 1451 1452 retval->chunk_hdr = chunk_hdr; 1453 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr); 1454 1455 /* Determine if the chunk needs to be authenticated */ 1456 if (sctp_auth_send_cid(type, asoc)) 1457 retval->auth = 1; 1458 1459 return retval; 1460 nodata: 1461 return NULL; 1462 } 1463 1464 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 1465 __u8 flags, int paylen, gfp_t gfp) 1466 { 1467 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp); 1468 } 1469 1470 struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc, 1471 __u8 flags, int paylen, gfp_t gfp) 1472 { 1473 return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp); 1474 } 1475 1476 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 1477 __u8 type, __u8 flags, int paylen, 1478 gfp_t gfp) 1479 { 1480 struct sctp_chunk *chunk; 1481 1482 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp); 1483 if (chunk) 1484 sctp_control_set_owner_w(chunk); 1485 1486 return chunk; 1487 } 1488 1489 /* Release the memory occupied by a chunk. */ 1490 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1491 { 1492 BUG_ON(!list_empty(&chunk->list)); 1493 list_del_init(&chunk->transmitted_list); 1494 1495 consume_skb(chunk->skb); 1496 consume_skb(chunk->auth_chunk); 1497 1498 SCTP_DBG_OBJCNT_DEC(chunk); 1499 kmem_cache_free(sctp_chunk_cachep, chunk); 1500 } 1501 1502 /* Possibly, free the chunk. */ 1503 void sctp_chunk_free(struct sctp_chunk *chunk) 1504 { 1505 /* Release our reference on the message tracker. */ 1506 if (chunk->msg) 1507 sctp_datamsg_put(chunk->msg); 1508 1509 sctp_chunk_put(chunk); 1510 } 1511 1512 /* Grab a reference to the chunk. */ 1513 void sctp_chunk_hold(struct sctp_chunk *ch) 1514 { 1515 refcount_inc(&ch->refcnt); 1516 } 1517 1518 /* Release a reference to the chunk. */ 1519 void sctp_chunk_put(struct sctp_chunk *ch) 1520 { 1521 if (refcount_dec_and_test(&ch->refcnt)) 1522 sctp_chunk_destroy(ch); 1523 } 1524 1525 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1526 * enough. 1527 */ 1528 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1529 { 1530 int chunklen = ntohs(chunk->chunk_hdr->length); 1531 int padlen = SCTP_PAD4(chunklen) - chunklen; 1532 void *target; 1533 1534 skb_put_zero(chunk->skb, padlen); 1535 target = skb_put_data(chunk->skb, data, len); 1536 1537 /* Adjust the chunk length field. */ 1538 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1539 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1540 1541 return target; 1542 } 1543 1544 /* Append bytes from user space to the end of a chunk. Will panic if 1545 * chunk is not big enough. 1546 * Returns a kernel err value. 1547 */ 1548 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len, 1549 struct iov_iter *from) 1550 { 1551 void *target; 1552 1553 /* Make room in chunk for data. */ 1554 target = skb_put(chunk->skb, len); 1555 1556 /* Copy data (whole iovec) into chunk */ 1557 if (!copy_from_iter_full(target, len, from)) 1558 return -EFAULT; 1559 1560 /* Adjust the chunk length field. */ 1561 chunk->chunk_hdr->length = 1562 htons(ntohs(chunk->chunk_hdr->length) + len); 1563 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1564 1565 return 0; 1566 } 1567 1568 /* Helper function to assign a TSN if needed. This assumes that both 1569 * the data_hdr and association have already been assigned. 1570 */ 1571 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1572 { 1573 struct sctp_stream *stream; 1574 struct sctp_chunk *lchunk; 1575 struct sctp_datamsg *msg; 1576 __u16 ssn, sid; 1577 1578 if (chunk->has_ssn) 1579 return; 1580 1581 /* All fragments will be on the same stream */ 1582 sid = ntohs(chunk->subh.data_hdr->stream); 1583 stream = &chunk->asoc->stream; 1584 1585 /* Now assign the sequence number to the entire message. 1586 * All fragments must have the same stream sequence number. 1587 */ 1588 msg = chunk->msg; 1589 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1590 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1591 ssn = 0; 1592 } else { 1593 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1594 ssn = sctp_ssn_next(stream, out, sid); 1595 else 1596 ssn = sctp_ssn_peek(stream, out, sid); 1597 } 1598 1599 lchunk->subh.data_hdr->ssn = htons(ssn); 1600 lchunk->has_ssn = 1; 1601 } 1602 } 1603 1604 /* Helper function to assign a TSN if needed. This assumes that both 1605 * the data_hdr and association have already been assigned. 1606 */ 1607 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1608 { 1609 if (!chunk->has_tsn) { 1610 /* This is the last possible instant to 1611 * assign a TSN. 1612 */ 1613 chunk->subh.data_hdr->tsn = 1614 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1615 chunk->has_tsn = 1; 1616 } 1617 } 1618 1619 /* Create a CLOSED association to use with an incoming packet. */ 1620 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1621 struct sctp_chunk *chunk, 1622 gfp_t gfp) 1623 { 1624 struct sctp_association *asoc; 1625 enum sctp_scope scope; 1626 struct sk_buff *skb; 1627 1628 /* Create the bare association. */ 1629 scope = sctp_scope(sctp_source(chunk)); 1630 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1631 if (!asoc) 1632 goto nodata; 1633 asoc->temp = 1; 1634 skb = chunk->skb; 1635 /* Create an entry for the source address of the packet. */ 1636 SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1); 1637 1638 nodata: 1639 return asoc; 1640 } 1641 1642 /* Build a cookie representing asoc. 1643 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1644 */ 1645 static struct sctp_cookie_param *sctp_pack_cookie( 1646 const struct sctp_endpoint *ep, 1647 const struct sctp_association *asoc, 1648 const struct sctp_chunk *init_chunk, 1649 int *cookie_len, const __u8 *raw_addrs, 1650 int addrs_len) 1651 { 1652 struct sctp_signed_cookie *cookie; 1653 struct sctp_cookie_param *retval; 1654 int headersize, bodysize; 1655 1656 /* Header size is static data prior to the actual cookie, including 1657 * any padding. 1658 */ 1659 headersize = sizeof(struct sctp_paramhdr) + 1660 (sizeof(struct sctp_signed_cookie) - 1661 sizeof(struct sctp_cookie)); 1662 bodysize = sizeof(struct sctp_cookie) 1663 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1664 1665 /* Pad out the cookie to a multiple to make the signature 1666 * functions simpler to write. 1667 */ 1668 if (bodysize % SCTP_COOKIE_MULTIPLE) 1669 bodysize += SCTP_COOKIE_MULTIPLE 1670 - (bodysize % SCTP_COOKIE_MULTIPLE); 1671 *cookie_len = headersize + bodysize; 1672 1673 /* Clear this memory since we are sending this data structure 1674 * out on the network. 1675 */ 1676 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1677 if (!retval) { 1678 *cookie_len = 0; 1679 return NULL; 1680 } 1681 1682 cookie = (struct sctp_signed_cookie *) retval->body; 1683 1684 /* Set up the parameter header. */ 1685 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1686 retval->p.length = htons(*cookie_len); 1687 1688 /* Copy the cookie part of the association itself. */ 1689 cookie->c = asoc->c; 1690 /* Save the raw address list length in the cookie. */ 1691 cookie->c.raw_addr_list_len = addrs_len; 1692 1693 /* Remember PR-SCTP capability. */ 1694 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1695 1696 /* Save adaptation indication in the cookie. */ 1697 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1698 1699 /* Set an expiration time for the cookie. */ 1700 cookie->c.expiration = ktime_add(asoc->cookie_life, 1701 ktime_get_real()); 1702 1703 /* Copy the peer's init packet. */ 1704 memcpy(cookie + 1, init_chunk->chunk_hdr, 1705 ntohs(init_chunk->chunk_hdr->length)); 1706 1707 /* Copy the raw local address list of the association. */ 1708 memcpy((__u8 *)(cookie + 1) + 1709 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1710 1711 /* Sign the cookie, if cookie authentication is enabled. */ 1712 if (sctp_sk(ep->base.sk)->cookie_auth_enable) { 1713 static_assert(sizeof(cookie->mac) == SHA256_DIGEST_SIZE); 1714 hmac_sha256(&ep->cookie_auth_key, (const u8 *)&cookie->c, 1715 bodysize, cookie->mac); 1716 } 1717 1718 return retval; 1719 } 1720 1721 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1722 struct sctp_association *sctp_unpack_cookie( 1723 const struct sctp_endpoint *ep, 1724 const struct sctp_association *asoc, 1725 struct sctp_chunk *chunk, gfp_t gfp, 1726 int *error, struct sctp_chunk **errp) 1727 { 1728 struct sctp_association *retval = NULL; 1729 int headersize, bodysize, fixed_size; 1730 struct sctp_signed_cookie *cookie; 1731 struct sk_buff *skb = chunk->skb; 1732 struct sctp_cookie *bear_cookie; 1733 struct sctp_chunkhdr *ch; 1734 unsigned int len, chlen; 1735 enum sctp_scope scope; 1736 ktime_t kt; 1737 1738 /* Header size is static data prior to the actual cookie, including 1739 * any padding. 1740 */ 1741 headersize = sizeof(struct sctp_chunkhdr) + 1742 (sizeof(struct sctp_signed_cookie) - 1743 sizeof(struct sctp_cookie)); 1744 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1745 fixed_size = headersize + sizeof(struct sctp_cookie); 1746 1747 /* Verify that the chunk looks like it even has a cookie. 1748 * There must be enough room for our cookie and our peer's 1749 * INIT chunk. 1750 */ 1751 len = ntohs(chunk->chunk_hdr->length); 1752 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1753 goto malformed; 1754 1755 /* Verify that the cookie has been padded out. */ 1756 if (bodysize % SCTP_COOKIE_MULTIPLE) 1757 goto malformed; 1758 1759 /* Process the cookie. */ 1760 cookie = chunk->subh.cookie_hdr; 1761 bear_cookie = &cookie->c; 1762 1763 ch = (struct sctp_chunkhdr *)(bear_cookie + 1); 1764 if (ch->type != SCTP_CID_INIT) 1765 goto malformed; 1766 chlen = ntohs(ch->length); 1767 if (chlen < sizeof(struct sctp_init_chunk)) 1768 goto malformed; 1769 if (chlen > len - fixed_size) 1770 goto malformed; 1771 if (bear_cookie->raw_addr_list_len > len - fixed_size - chlen) 1772 goto malformed; 1773 1774 /* Verify the cookie's MAC, if cookie authentication is enabled. */ 1775 if (sctp_sk(ep->base.sk)->cookie_auth_enable) { 1776 u8 mac[SHA256_DIGEST_SIZE]; 1777 1778 hmac_sha256(&ep->cookie_auth_key, (const u8 *)bear_cookie, 1779 bodysize, mac); 1780 static_assert(sizeof(cookie->mac) == sizeof(mac)); 1781 if (crypto_memneq(mac, cookie->mac, sizeof(mac))) { 1782 *error = -SCTP_IERROR_BAD_SIG; 1783 goto fail; 1784 } 1785 } 1786 1787 /* IG Section 2.35.2: 1788 * 3) Compare the port numbers and the verification tag contained 1789 * within the COOKIE ECHO chunk to the actual port numbers and the 1790 * verification tag within the SCTP common header of the received 1791 * packet. If these values do not match the packet MUST be silently 1792 * discarded, 1793 */ 1794 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1795 *error = -SCTP_IERROR_BAD_TAG; 1796 goto fail; 1797 } 1798 1799 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1800 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1801 *error = -SCTP_IERROR_BAD_PORTS; 1802 goto fail; 1803 } 1804 1805 /* Check to see if the cookie is stale. RFC 9260 Section 5.2.4 1806 * exempts an expired cookie only when both Verification Tags match 1807 * the current association. 1808 * If skb has been timestamped, then use the stamp, otherwise 1809 * use current time. This introduces a small possibility that 1810 * a cookie may be considered expired, but this would only slow 1811 * down the new association establishment instead of every packet. 1812 */ 1813 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1814 kt = skb_get_ktime(skb); 1815 else 1816 kt = ktime_get_real(); 1817 1818 if ((!asoc || 1819 asoc->c.my_vtag != bear_cookie->my_vtag || 1820 asoc->c.peer_vtag != bear_cookie->peer_vtag) && 1821 ktime_before(bear_cookie->expiration, kt)) { 1822 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); 1823 __be32 n = htonl(usecs); 1824 1825 /* 1826 * Section 3.3.10.3 Stale Cookie Error (3) 1827 * 1828 * Cause of error 1829 * --------------- 1830 * Stale Cookie Error: Indicates the receipt of a valid State 1831 * Cookie that has expired. 1832 */ 1833 *errp = sctp_make_op_error(asoc, chunk, 1834 SCTP_ERROR_STALE_COOKIE, &n, 1835 sizeof(n), 0); 1836 if (*errp) 1837 *error = -SCTP_IERROR_STALE_COOKIE; 1838 else 1839 *error = -SCTP_IERROR_NOMEM; 1840 1841 goto fail; 1842 } 1843 1844 /* Make a new base association. */ 1845 scope = sctp_scope(sctp_source(chunk)); 1846 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1847 if (!retval) { 1848 *error = -SCTP_IERROR_NOMEM; 1849 goto fail; 1850 } 1851 1852 /* Set up our peer's port number. */ 1853 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1854 1855 if (!sctp_auth_verify_cookie_params(ep, bear_cookie)) 1856 goto malformed; 1857 1858 /* Populate the association from the cookie. */ 1859 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1860 1861 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1862 GFP_ATOMIC) < 0) { 1863 *error = -SCTP_IERROR_NOMEM; 1864 goto fail; 1865 } 1866 1867 /* Also, add the destination address. */ 1868 if (list_empty(&retval->base.bind_addr.address_list)) { 1869 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1870 sizeof(chunk->dest), SCTP_ADDR_SRC, 1871 GFP_ATOMIC); 1872 } 1873 1874 retval->next_tsn = retval->c.initial_tsn; 1875 retval->ctsn_ack_point = retval->next_tsn - 1; 1876 retval->addip_serial = retval->c.initial_tsn; 1877 retval->strreset_outseq = retval->c.initial_tsn; 1878 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1879 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1880 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1881 1882 /* The INIT stuff will be done by the side effects. */ 1883 return retval; 1884 1885 fail: 1886 if (retval) 1887 sctp_association_free(retval); 1888 1889 return NULL; 1890 1891 malformed: 1892 /* Yikes! The packet is either corrupt or deliberately 1893 * malformed. 1894 */ 1895 *error = -SCTP_IERROR_MALFORMED; 1896 goto fail; 1897 } 1898 1899 /******************************************************************** 1900 * 3rd Level Abstractions 1901 ********************************************************************/ 1902 1903 struct __sctp_missing { 1904 __be32 num_missing; 1905 __be16 type; 1906 } __packed; 1907 1908 /* 1909 * Report a missing mandatory parameter. 1910 */ 1911 static int sctp_process_missing_param(const struct sctp_association *asoc, 1912 enum sctp_param paramtype, 1913 struct sctp_chunk *chunk, 1914 struct sctp_chunk **errp) 1915 { 1916 struct __sctp_missing report; 1917 __u16 len; 1918 1919 len = SCTP_PAD4(sizeof(report)); 1920 1921 /* Make an ERROR chunk, preparing enough room for 1922 * returning multiple unknown parameters. 1923 */ 1924 if (!*errp) 1925 *errp = sctp_make_op_error_space(asoc, chunk, len); 1926 1927 if (*errp) { 1928 report.num_missing = htonl(1); 1929 report.type = paramtype; 1930 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1931 sizeof(report)); 1932 sctp_addto_chunk(*errp, sizeof(report), &report); 1933 } 1934 1935 /* Stop processing this chunk. */ 1936 return 0; 1937 } 1938 1939 /* Report an Invalid Mandatory Parameter. */ 1940 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1941 struct sctp_chunk *chunk, 1942 struct sctp_chunk **errp) 1943 { 1944 /* Invalid Mandatory Parameter Error has no payload. */ 1945 1946 if (!*errp) 1947 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1948 1949 if (*errp) 1950 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1951 1952 /* Stop processing this chunk. */ 1953 return 0; 1954 } 1955 1956 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1957 struct sctp_paramhdr *param, 1958 const struct sctp_chunk *chunk, 1959 struct sctp_chunk **errp) 1960 { 1961 /* This is a fatal error. Any accumulated non-fatal errors are 1962 * not reported. 1963 */ 1964 if (*errp) 1965 sctp_chunk_free(*errp); 1966 1967 /* Create an error chunk and fill it in with our payload. */ 1968 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1969 1970 return 0; 1971 } 1972 1973 1974 /* Do not attempt to handle the HOST_NAME parm. However, do 1975 * send back an indicator to the peer. 1976 */ 1977 static int sctp_process_hn_param(const struct sctp_association *asoc, 1978 union sctp_params param, 1979 struct sctp_chunk *chunk, 1980 struct sctp_chunk **errp) 1981 { 1982 __u16 len = ntohs(param.p->length); 1983 1984 /* Processing of the HOST_NAME parameter will generate an 1985 * ABORT. If we've accumulated any non-fatal errors, they 1986 * would be unrecognized parameters and we should not include 1987 * them in the ABORT. 1988 */ 1989 if (*errp) 1990 sctp_chunk_free(*errp); 1991 1992 *errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_DNS_FAILED, 1993 param.v, len, 0); 1994 1995 /* Stop processing this chunk. */ 1996 return 0; 1997 } 1998 1999 static int sctp_verify_ext_param(struct net *net, 2000 const struct sctp_endpoint *ep, 2001 union sctp_params param) 2002 { 2003 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2004 int have_asconf = 0; 2005 int have_auth = 0; 2006 int i; 2007 2008 for (i = 0; i < num_ext; i++) { 2009 switch (param.ext->chunks[i]) { 2010 case SCTP_CID_AUTH: 2011 have_auth = 1; 2012 break; 2013 case SCTP_CID_ASCONF: 2014 case SCTP_CID_ASCONF_ACK: 2015 have_asconf = 1; 2016 break; 2017 } 2018 } 2019 2020 /* ADD-IP Security: The draft requires us to ABORT or ignore the 2021 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 2022 * only if ADD-IP is turned on and we are not backward-compatible 2023 * mode. 2024 */ 2025 if (net->sctp.addip_noauth) 2026 return 1; 2027 2028 if (ep->asconf_enable && !have_auth && have_asconf) 2029 return 0; 2030 2031 return 1; 2032 } 2033 2034 static void sctp_process_ext_param(struct sctp_association *asoc, 2035 union sctp_params param) 2036 { 2037 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2038 int i; 2039 2040 for (i = 0; i < num_ext; i++) { 2041 switch (param.ext->chunks[i]) { 2042 case SCTP_CID_RECONF: 2043 if (asoc->ep->reconf_enable) 2044 asoc->peer.reconf_capable = 1; 2045 break; 2046 case SCTP_CID_FWD_TSN: 2047 if (asoc->ep->prsctp_enable) 2048 asoc->peer.prsctp_capable = 1; 2049 break; 2050 case SCTP_CID_AUTH: 2051 /* if the peer reports AUTH, assume that he 2052 * supports AUTH. 2053 */ 2054 if (asoc->ep->auth_enable) 2055 asoc->peer.auth_capable = 1; 2056 break; 2057 case SCTP_CID_ASCONF: 2058 case SCTP_CID_ASCONF_ACK: 2059 if (asoc->ep->asconf_enable) 2060 asoc->peer.asconf_capable = 1; 2061 break; 2062 case SCTP_CID_I_DATA: 2063 if (asoc->ep->intl_enable) 2064 asoc->peer.intl_capable = 1; 2065 break; 2066 default: 2067 break; 2068 } 2069 } 2070 } 2071 2072 /* RFC 3.2.1 & the Implementers Guide 2.2. 2073 * 2074 * The Parameter Types are encoded such that the 2075 * highest-order two bits specify the action that must be 2076 * taken if the processing endpoint does not recognize the 2077 * Parameter Type. 2078 * 2079 * 00 - Stop processing this parameter; do not process any further 2080 * parameters within this chunk 2081 * 2082 * 01 - Stop processing this parameter, do not process any further 2083 * parameters within this chunk, and report the unrecognized 2084 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2085 * 2086 * 10 - Skip this parameter and continue processing. 2087 * 2088 * 11 - Skip this parameter and continue processing but 2089 * report the unrecognized parameter in an 2090 * 'Unrecognized Parameter' ERROR chunk. 2091 * 2092 * Return value: 2093 * SCTP_IERROR_NO_ERROR - continue with the chunk 2094 * SCTP_IERROR_ERROR - stop and report an error. 2095 * SCTP_IERROR_NOMEME - out of memory. 2096 */ 2097 static enum sctp_ierror sctp_process_unk_param( 2098 const struct sctp_association *asoc, 2099 union sctp_params param, 2100 struct sctp_chunk *chunk, 2101 struct sctp_chunk **errp) 2102 { 2103 int retval = SCTP_IERROR_NO_ERROR; 2104 2105 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2106 case SCTP_PARAM_ACTION_DISCARD: 2107 retval = SCTP_IERROR_ERROR; 2108 break; 2109 case SCTP_PARAM_ACTION_SKIP: 2110 break; 2111 case SCTP_PARAM_ACTION_DISCARD_ERR: 2112 retval = SCTP_IERROR_ERROR; 2113 fallthrough; 2114 case SCTP_PARAM_ACTION_SKIP_ERR: 2115 /* Make an ERROR chunk, preparing enough room for 2116 * returning multiple unknown parameters. 2117 */ 2118 if (!*errp) { 2119 *errp = sctp_make_op_error_limited(asoc, chunk); 2120 if (!*errp) { 2121 /* If there is no memory for generating the 2122 * ERROR report as specified, an ABORT will be 2123 * triggered to the peer and the association 2124 * won't be established. 2125 */ 2126 retval = SCTP_IERROR_NOMEM; 2127 break; 2128 } 2129 } 2130 2131 if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2132 ntohs(param.p->length))) 2133 sctp_addto_chunk(*errp, ntohs(param.p->length), 2134 param.v); 2135 break; 2136 default: 2137 break; 2138 } 2139 2140 return retval; 2141 } 2142 2143 /* Verify variable length parameters 2144 * Return values: 2145 * SCTP_IERROR_ABORT - trigger an ABORT 2146 * SCTP_IERROR_NOMEM - out of memory (abort) 2147 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2148 * SCTP_IERROR_NO_ERROR - continue with the chunk 2149 */ 2150 static enum sctp_ierror sctp_verify_param(struct net *net, 2151 const struct sctp_endpoint *ep, 2152 const struct sctp_association *asoc, 2153 union sctp_params param, 2154 enum sctp_cid cid, 2155 struct sctp_chunk *chunk, 2156 struct sctp_chunk **err_chunk) 2157 { 2158 struct sctp_hmac_algo_param *hmacs; 2159 int retval = SCTP_IERROR_NO_ERROR; 2160 __u16 n_elt, id = 0; 2161 int i; 2162 2163 /* FIXME - This routine is not looking at each parameter per the 2164 * chunk type, i.e., unrecognized parameters should be further 2165 * identified based on the chunk id. 2166 */ 2167 2168 switch (param.p->type) { 2169 case SCTP_PARAM_IPV4_ADDRESS: 2170 case SCTP_PARAM_IPV6_ADDRESS: 2171 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2172 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2173 case SCTP_PARAM_STATE_COOKIE: 2174 case SCTP_PARAM_HEARTBEAT_INFO: 2175 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2176 case SCTP_PARAM_ECN_CAPABLE: 2177 break; 2178 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2179 if (ntohs(param.p->length) != sizeof(*param.aind)) { 2180 sctp_process_inv_paramlength(asoc, param.p, 2181 chunk, err_chunk); 2182 retval = SCTP_IERROR_ABORT; 2183 } 2184 break; 2185 2186 case SCTP_PARAM_SUPPORTED_EXT: 2187 if (!sctp_verify_ext_param(net, ep, param)) 2188 return SCTP_IERROR_ABORT; 2189 break; 2190 2191 case SCTP_PARAM_SET_PRIMARY: 2192 if (!ep->asconf_enable) 2193 goto unhandled; 2194 2195 if (ntohs(param.p->length) < sizeof(struct sctp_addip_param) + 2196 sizeof(struct sctp_paramhdr)) { 2197 sctp_process_inv_paramlength(asoc, param.p, 2198 chunk, err_chunk); 2199 retval = SCTP_IERROR_ABORT; 2200 } 2201 break; 2202 2203 case SCTP_PARAM_HOST_NAME_ADDRESS: 2204 /* This param has been Deprecated, send ABORT. */ 2205 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2206 retval = SCTP_IERROR_ABORT; 2207 break; 2208 2209 case SCTP_PARAM_FWD_TSN_SUPPORT: 2210 if (ep->prsctp_enable) 2211 break; 2212 goto unhandled; 2213 2214 case SCTP_PARAM_RANDOM: 2215 if (!ep->auth_enable) 2216 goto unhandled; 2217 2218 /* SCTP-AUTH: Secion 6.1 2219 * If the random number is not 32 byte long the association 2220 * MUST be aborted. The ABORT chunk SHOULD contain the error 2221 * cause 'Protocol Violation'. 2222 */ 2223 if (SCTP_AUTH_RANDOM_LENGTH != ntohs(param.p->length) - 2224 sizeof(struct sctp_paramhdr)) { 2225 sctp_process_inv_paramlength(asoc, param.p, 2226 chunk, err_chunk); 2227 retval = SCTP_IERROR_ABORT; 2228 } 2229 break; 2230 2231 case SCTP_PARAM_CHUNKS: 2232 if (!ep->auth_enable) 2233 goto unhandled; 2234 2235 /* SCTP-AUTH: Section 3.2 2236 * The CHUNKS parameter MUST be included once in the INIT or 2237 * INIT-ACK chunk if the sender wants to receive authenticated 2238 * chunks. Its maximum length is 260 bytes. 2239 */ 2240 if (260 < ntohs(param.p->length)) { 2241 sctp_process_inv_paramlength(asoc, param.p, 2242 chunk, err_chunk); 2243 retval = SCTP_IERROR_ABORT; 2244 } 2245 break; 2246 2247 case SCTP_PARAM_HMAC_ALGO: 2248 if (!ep->auth_enable) 2249 goto unhandled; 2250 2251 hmacs = (struct sctp_hmac_algo_param *)param.p; 2252 n_elt = (ntohs(param.p->length) - 2253 sizeof(struct sctp_paramhdr)) >> 1; 2254 2255 /* SCTP-AUTH: Section 6.1 2256 * The HMAC algorithm based on SHA-1 MUST be supported and 2257 * included in the HMAC-ALGO parameter. 2258 */ 2259 for (i = 0; i < n_elt; i++) { 2260 id = ntohs(hmacs->hmac_ids[i]); 2261 2262 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2263 break; 2264 } 2265 2266 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2267 sctp_process_inv_paramlength(asoc, param.p, chunk, 2268 err_chunk); 2269 retval = SCTP_IERROR_ABORT; 2270 } 2271 break; 2272 unhandled: 2273 default: 2274 pr_debug("%s: unrecognized param:%d for chunk:%d\n", 2275 __func__, ntohs(param.p->type), cid); 2276 2277 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2278 break; 2279 } 2280 return retval; 2281 } 2282 2283 /* Verify the INIT packet before we process it. */ 2284 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 2285 const struct sctp_association *asoc, enum sctp_cid cid, 2286 struct sctp_init_chunk *peer_init, 2287 struct sctp_chunk *chunk, struct sctp_chunk **errp) 2288 { 2289 union sctp_params param; 2290 bool has_cookie = false; 2291 int result; 2292 2293 /* Check for missing mandatory parameters. Note: Initial TSN is 2294 * also mandatory, but is not checked here since the valid range 2295 * is 0..2**32-1. RFC4960, section 3.3.3. 2296 */ 2297 if (peer_init->init_hdr.num_outbound_streams == 0 || 2298 peer_init->init_hdr.num_inbound_streams == 0 || 2299 peer_init->init_hdr.init_tag == 0 || 2300 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) 2301 return sctp_process_inv_mandatory(asoc, chunk, errp); 2302 2303 sctp_walk_params(param, peer_init) { 2304 if (param.p->type == SCTP_PARAM_STATE_COOKIE) 2305 has_cookie = true; 2306 } 2307 2308 /* There is a possibility that a parameter length was bad and 2309 * in that case we would have stoped walking the parameters. 2310 * The current param.p would point at the bad one. 2311 * Current consensus on the mailing list is to generate a PROTOCOL 2312 * VIOLATION error. We build the ERROR chunk here and let the normal 2313 * error handling code build and send the packet. 2314 */ 2315 if (param.v != (void *)peer_init + 2316 SCTP_PAD4(ntohs(peer_init->chunk_hdr.length))) 2317 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2318 2319 /* The only missing mandatory param possible today is 2320 * the state cookie for an INIT-ACK chunk. 2321 */ 2322 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2323 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2324 chunk, errp); 2325 2326 /* Verify all the variable length parameters */ 2327 sctp_walk_params(param, peer_init) { 2328 result = sctp_verify_param(net, ep, asoc, param, cid, 2329 chunk, errp); 2330 switch (result) { 2331 case SCTP_IERROR_ABORT: 2332 case SCTP_IERROR_NOMEM: 2333 return 0; 2334 case SCTP_IERROR_ERROR: 2335 return 1; 2336 case SCTP_IERROR_NO_ERROR: 2337 default: 2338 break; 2339 } 2340 2341 } /* for (loop through all parameters) */ 2342 2343 return 1; 2344 } 2345 2346 /* Unpack the parameters in an INIT packet into an association. 2347 * Returns 0 on failure, else success. 2348 * FIXME: This is an association method. 2349 */ 2350 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2351 const union sctp_addr *peer_addr, 2352 struct sctp_init_chunk *peer_init, gfp_t gfp) 2353 { 2354 struct sctp_transport *transport; 2355 struct list_head *pos, *temp; 2356 union sctp_params param; 2357 union sctp_addr addr; 2358 struct sctp_af *af; 2359 int src_match = 0; 2360 2361 /* We must include the address that the INIT packet came from. 2362 * This is the only address that matters for an INIT packet. 2363 * When processing a COOKIE ECHO, we retrieve the from address 2364 * of the INIT from the cookie. 2365 */ 2366 2367 /* This implementation defaults to making the first transport 2368 * added as the primary transport. The source address seems to 2369 * be a better choice than any of the embedded addresses. 2370 */ 2371 asoc->encap_port = SCTP_INPUT_CB(chunk->skb)->encap_port; 2372 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2373 goto nomem; 2374 2375 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2376 src_match = 1; 2377 2378 /* Process the initialization parameters. */ 2379 sctp_walk_params(param, peer_init) { 2380 if (!src_match && 2381 (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2382 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2383 af = sctp_get_af_specific(param_type2af(param.p->type)); 2384 if (!af->from_addr_param(&addr, param.addr, 2385 chunk->sctp_hdr->source, 0)) 2386 continue; 2387 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2388 src_match = 1; 2389 } 2390 2391 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2392 goto clean_up; 2393 } 2394 2395 /* source address of chunk may not match any valid address */ 2396 if (!src_match) 2397 goto clean_up; 2398 2399 /* AUTH: After processing the parameters, make sure that we 2400 * have all the required info to potentially do authentications. 2401 */ 2402 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2403 !asoc->peer.peer_hmacs)) 2404 asoc->peer.auth_capable = 0; 2405 2406 /* In a non-backward compatible mode, if the peer claims 2407 * support for ADD-IP but not AUTH, the ADD-IP spec states 2408 * that we MUST ABORT the association. Section 6. The section 2409 * also give us an option to silently ignore the packet, which 2410 * is what we'll do here. 2411 */ 2412 if (!asoc->base.net->sctp.addip_noauth && 2413 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2414 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2415 SCTP_PARAM_DEL_IP | 2416 SCTP_PARAM_SET_PRIMARY); 2417 asoc->peer.asconf_capable = 0; 2418 goto clean_up; 2419 } 2420 2421 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2422 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2423 transport = list_entry(pos, struct sctp_transport, transports); 2424 if (transport->state == SCTP_UNKNOWN) { 2425 sctp_assoc_rm_peer(asoc, transport); 2426 } 2427 } 2428 2429 /* The fixed INIT headers are always in network byte 2430 * order. 2431 */ 2432 asoc->peer.i.init_tag = 2433 ntohl(peer_init->init_hdr.init_tag); 2434 asoc->peer.i.a_rwnd = 2435 ntohl(peer_init->init_hdr.a_rwnd); 2436 asoc->peer.i.num_outbound_streams = 2437 ntohs(peer_init->init_hdr.num_outbound_streams); 2438 asoc->peer.i.num_inbound_streams = 2439 ntohs(peer_init->init_hdr.num_inbound_streams); 2440 asoc->peer.i.initial_tsn = 2441 ntohl(peer_init->init_hdr.initial_tsn); 2442 2443 asoc->strreset_inseq = asoc->peer.i.initial_tsn; 2444 2445 /* Apply the upper bounds for output streams based on peer's 2446 * number of inbound streams. 2447 */ 2448 if (asoc->c.sinit_num_ostreams > 2449 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2450 asoc->c.sinit_num_ostreams = 2451 ntohs(peer_init->init_hdr.num_inbound_streams); 2452 } 2453 2454 if (asoc->c.sinit_max_instreams > 2455 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2456 asoc->c.sinit_max_instreams = 2457 ntohs(peer_init->init_hdr.num_outbound_streams); 2458 } 2459 2460 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2461 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2462 2463 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2464 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2465 2466 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2467 * high (for example, implementations MAY use the size of the receiver 2468 * advertised window). 2469 */ 2470 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2471 transports) { 2472 transport->ssthresh = asoc->peer.i.a_rwnd; 2473 } 2474 2475 /* Set up the TSN tracking pieces. */ 2476 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2477 asoc->peer.i.initial_tsn, gfp)) 2478 goto clean_up; 2479 2480 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2481 * 2482 * The stream sequence number in all the streams shall start 2483 * from 0 when the association is established. Also, when the 2484 * stream sequence number reaches the value 65535 the next 2485 * stream sequence number shall be set to 0. 2486 */ 2487 2488 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams, 2489 asoc->c.sinit_max_instreams, gfp)) 2490 goto clean_up; 2491 2492 /* Update frag_point when stream_interleave may get changed. */ 2493 sctp_assoc_update_frag_point(asoc); 2494 2495 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp)) 2496 goto clean_up; 2497 2498 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2499 * 2500 * When an endpoint has an ASCONF signaled change to be sent to the 2501 * remote endpoint it should do the following: 2502 * ... 2503 * A2) A serial number should be assigned to the Chunk. The serial 2504 * number should be a monotonically increasing number. All serial 2505 * numbers are defined to be initialized at the start of the 2506 * association to the same value as the Initial TSN. 2507 */ 2508 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2509 return 1; 2510 2511 clean_up: 2512 /* Release the transport structures. */ 2513 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2514 transport = list_entry(pos, struct sctp_transport, transports); 2515 if (transport->state != SCTP_ACTIVE) 2516 sctp_assoc_rm_peer(asoc, transport); 2517 } 2518 2519 nomem: 2520 return 0; 2521 } 2522 2523 2524 /* Update asoc with the option described in param. 2525 * 2526 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2527 * 2528 * asoc is the association to update. 2529 * param is the variable length parameter to use for update. 2530 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2531 * If the current packet is an INIT we want to minimize the amount of 2532 * work we do. In particular, we should not build transport 2533 * structures for the addresses. 2534 */ 2535 static int sctp_process_param(struct sctp_association *asoc, 2536 union sctp_params param, 2537 const union sctp_addr *peer_addr, 2538 gfp_t gfp) 2539 { 2540 struct sctp_endpoint *ep = asoc->ep; 2541 union sctp_addr_param *addr_param; 2542 struct net *net = asoc->base.net; 2543 struct sctp_transport *t; 2544 enum sctp_scope scope; 2545 union sctp_addr addr; 2546 struct sctp_af *af; 2547 int retval = 1, i; 2548 u32 stale; 2549 __u16 sat; 2550 2551 /* We maintain all INIT parameters in network byte order all the 2552 * time. This allows us to not worry about whether the parameters 2553 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2554 */ 2555 switch (param.p->type) { 2556 case SCTP_PARAM_IPV6_ADDRESS: 2557 if (PF_INET6 != asoc->base.sk->sk_family) 2558 break; 2559 goto do_addr_param; 2560 2561 case SCTP_PARAM_IPV4_ADDRESS: 2562 /* v4 addresses are not allowed on v6-only socket */ 2563 if (ipv6_only_sock(asoc->base.sk)) 2564 break; 2565 do_addr_param: 2566 af = sctp_get_af_specific(param_type2af(param.p->type)); 2567 if (!af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0)) 2568 break; 2569 scope = sctp_scope(peer_addr); 2570 if (sctp_in_scope(net, &addr, scope)) 2571 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2572 return 0; 2573 break; 2574 2575 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2576 if (!net->sctp.cookie_preserve_enable) 2577 break; 2578 2579 stale = ntohl(param.life->lifespan_increment); 2580 2581 /* Suggested Cookie Life span increment's unit is msec, 2582 * (1/1000sec). 2583 */ 2584 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale); 2585 break; 2586 2587 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2588 /* Turn off the default values first so we'll know which 2589 * ones are really set by the peer. 2590 */ 2591 asoc->peer.ipv4_address = 0; 2592 asoc->peer.ipv6_address = 0; 2593 2594 /* Assume that peer supports the address family 2595 * by which it sends a packet. 2596 */ 2597 if (peer_addr->sa.sa_family == AF_INET6) 2598 asoc->peer.ipv6_address = 1; 2599 else if (peer_addr->sa.sa_family == AF_INET) 2600 asoc->peer.ipv4_address = 1; 2601 2602 /* Cycle through address types; avoid divide by 0. */ 2603 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2604 if (sat) 2605 sat /= sizeof(__u16); 2606 2607 for (i = 0; i < sat; ++i) { 2608 switch (param.sat->types[i]) { 2609 case SCTP_PARAM_IPV4_ADDRESS: 2610 asoc->peer.ipv4_address = 1; 2611 break; 2612 2613 case SCTP_PARAM_IPV6_ADDRESS: 2614 if (PF_INET6 == asoc->base.sk->sk_family) 2615 asoc->peer.ipv6_address = 1; 2616 break; 2617 2618 default: /* Just ignore anything else. */ 2619 break; 2620 } 2621 } 2622 break; 2623 2624 case SCTP_PARAM_STATE_COOKIE: 2625 asoc->peer.cookie_len = 2626 ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2627 kfree(asoc->peer.cookie); 2628 asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp); 2629 if (!asoc->peer.cookie) 2630 retval = 0; 2631 break; 2632 2633 case SCTP_PARAM_HEARTBEAT_INFO: 2634 /* Would be odd to receive, but it causes no problems. */ 2635 break; 2636 2637 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2638 /* Rejected during verify stage. */ 2639 break; 2640 2641 case SCTP_PARAM_ECN_CAPABLE: 2642 if (asoc->ep->ecn_enable) { 2643 asoc->peer.ecn_capable = 1; 2644 break; 2645 } 2646 /* Fall Through */ 2647 goto fall_through; 2648 2649 2650 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2651 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2652 break; 2653 2654 case SCTP_PARAM_SET_PRIMARY: 2655 if (!ep->asconf_enable) 2656 goto fall_through; 2657 2658 addr_param = param.v + sizeof(struct sctp_addip_param); 2659 if (ntohs(addr_param->p.length) > 2660 ntohs(param.p->length) - sizeof(struct sctp_addip_param)) 2661 break; 2662 2663 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 2664 if (!af) 2665 break; 2666 2667 if (!af->from_addr_param(&addr, addr_param, 2668 htons(asoc->peer.port), 0)) 2669 break; 2670 2671 if (!af->addr_valid(&addr, NULL, NULL)) 2672 break; 2673 2674 t = sctp_assoc_lookup_paddr(asoc, &addr); 2675 if (!t) 2676 break; 2677 2678 sctp_assoc_set_primary(asoc, t); 2679 break; 2680 2681 case SCTP_PARAM_SUPPORTED_EXT: 2682 sctp_process_ext_param(asoc, param); 2683 break; 2684 2685 case SCTP_PARAM_FWD_TSN_SUPPORT: 2686 if (asoc->ep->prsctp_enable) { 2687 asoc->peer.prsctp_capable = 1; 2688 break; 2689 } 2690 /* Fall Through */ 2691 goto fall_through; 2692 2693 case SCTP_PARAM_RANDOM: 2694 if (!ep->auth_enable) 2695 goto fall_through; 2696 2697 /* Save peer's random parameter */ 2698 kfree(asoc->peer.peer_random); 2699 asoc->peer.peer_random = kmemdup(param.p, 2700 ntohs(param.p->length), gfp); 2701 if (!asoc->peer.peer_random) { 2702 retval = 0; 2703 break; 2704 } 2705 break; 2706 2707 case SCTP_PARAM_HMAC_ALGO: 2708 if (!ep->auth_enable) 2709 goto fall_through; 2710 2711 /* Save peer's HMAC list */ 2712 kfree(asoc->peer.peer_hmacs); 2713 asoc->peer.peer_hmacs = kmemdup(param.p, 2714 ntohs(param.p->length), gfp); 2715 if (!asoc->peer.peer_hmacs) { 2716 retval = 0; 2717 break; 2718 } 2719 2720 /* Set the default HMAC the peer requested*/ 2721 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2722 break; 2723 2724 case SCTP_PARAM_CHUNKS: 2725 if (!ep->auth_enable) 2726 goto fall_through; 2727 2728 kfree(asoc->peer.peer_chunks); 2729 asoc->peer.peer_chunks = kmemdup(param.p, 2730 ntohs(param.p->length), gfp); 2731 if (!asoc->peer.peer_chunks) 2732 retval = 0; 2733 break; 2734 fall_through: 2735 default: 2736 /* Any unrecognized parameters should have been caught 2737 * and handled by sctp_verify_param() which should be 2738 * called prior to this routine. Simply log the error 2739 * here. 2740 */ 2741 pr_debug("%s: ignoring param:%d for association:%p.\n", 2742 __func__, ntohs(param.p->type), asoc); 2743 break; 2744 } 2745 2746 return retval; 2747 } 2748 2749 /* Select a new verification tag. */ 2750 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2751 { 2752 /* I believe that this random number generator complies with RFC1750. 2753 * A tag of 0 is reserved for special cases (e.g. INIT). 2754 */ 2755 __u32 x; 2756 2757 do { 2758 x = get_random_u32(); 2759 } while (x == 0); 2760 2761 return x; 2762 } 2763 2764 /* Select an initial TSN to send during startup. */ 2765 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2766 { 2767 __u32 retval; 2768 2769 retval = get_random_u32(); 2770 return retval; 2771 } 2772 2773 /* 2774 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2775 * 0 1 2 3 2776 * 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 2777 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2778 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2779 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2780 * | Serial Number | 2781 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2782 * | Address Parameter | 2783 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2784 * | ASCONF Parameter #1 | 2785 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2786 * \ \ 2787 * / .... / 2788 * \ \ 2789 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2790 * | ASCONF Parameter #N | 2791 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2792 * 2793 * Address Parameter and other parameter will not be wrapped in this function 2794 */ 2795 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2796 union sctp_addr *addr, 2797 int vparam_len) 2798 { 2799 struct sctp_addiphdr asconf; 2800 struct sctp_chunk *retval; 2801 int length = sizeof(asconf) + vparam_len; 2802 union sctp_addr_param addrparam; 2803 int addrlen; 2804 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2805 2806 addrlen = af->to_addr_param(addr, &addrparam); 2807 if (!addrlen) 2808 return NULL; 2809 length += addrlen; 2810 2811 /* Create the chunk. */ 2812 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length, 2813 GFP_ATOMIC); 2814 if (!retval) 2815 return NULL; 2816 2817 asconf.serial = htonl(asoc->addip_serial++); 2818 2819 retval->subh.addip_hdr = 2820 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2821 retval->param_hdr.v = 2822 sctp_addto_chunk(retval, addrlen, &addrparam); 2823 2824 return retval; 2825 } 2826 2827 /* ADDIP 2828 * 3.2.1 Add IP Address 2829 * 0 1 2 3 2830 * 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 2831 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2832 * | Type = 0xC001 | Length = Variable | 2833 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2834 * | ASCONF-Request Correlation ID | 2835 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2836 * | Address Parameter | 2837 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2838 * 2839 * 3.2.2 Delete IP Address 2840 * 0 1 2 3 2841 * 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 2842 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2843 * | Type = 0xC002 | Length = Variable | 2844 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2845 * | ASCONF-Request Correlation ID | 2846 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2847 * | Address Parameter | 2848 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2849 * 2850 */ 2851 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2852 union sctp_addr *laddr, 2853 struct sockaddr *addrs, 2854 int addrcnt, __be16 flags) 2855 { 2856 union sctp_addr_param addr_param; 2857 struct sctp_addip_param param; 2858 int paramlen = sizeof(param); 2859 struct sctp_chunk *retval; 2860 int addr_param_len = 0; 2861 union sctp_addr *addr; 2862 int totallen = 0, i; 2863 int del_pickup = 0; 2864 struct sctp_af *af; 2865 void *addr_buf; 2866 2867 /* Get total length of all the address parameters. */ 2868 addr_buf = addrs; 2869 for (i = 0; i < addrcnt; i++) { 2870 addr = addr_buf; 2871 af = sctp_get_af_specific(addr->v4.sin_family); 2872 addr_param_len = af->to_addr_param(addr, &addr_param); 2873 2874 totallen += paramlen; 2875 totallen += addr_param_len; 2876 2877 addr_buf += af->sockaddr_len; 2878 if (asoc->asconf_addr_del_pending && !del_pickup) { 2879 /* reuse the parameter length from the same scope one */ 2880 totallen += paramlen; 2881 totallen += addr_param_len; 2882 del_pickup = 1; 2883 2884 pr_debug("%s: picked same-scope del_pending addr, " 2885 "totallen for all addresses is %d\n", 2886 __func__, totallen); 2887 } 2888 } 2889 2890 /* Create an asconf chunk with the required length. */ 2891 retval = sctp_make_asconf(asoc, laddr, totallen); 2892 if (!retval) 2893 return NULL; 2894 2895 /* Add the address parameters to the asconf chunk. */ 2896 addr_buf = addrs; 2897 for (i = 0; i < addrcnt; i++) { 2898 addr = addr_buf; 2899 af = sctp_get_af_specific(addr->v4.sin_family); 2900 addr_param_len = af->to_addr_param(addr, &addr_param); 2901 param.param_hdr.type = flags; 2902 param.param_hdr.length = htons(paramlen + addr_param_len); 2903 param.crr_id = htonl(i); 2904 2905 sctp_addto_chunk(retval, paramlen, ¶m); 2906 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2907 2908 addr_buf += af->sockaddr_len; 2909 } 2910 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2911 addr = asoc->asconf_addr_del_pending; 2912 af = sctp_get_af_specific(addr->v4.sin_family); 2913 addr_param_len = af->to_addr_param(addr, &addr_param); 2914 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2915 param.param_hdr.length = htons(paramlen + addr_param_len); 2916 param.crr_id = htonl(i); 2917 2918 sctp_addto_chunk(retval, paramlen, ¶m); 2919 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2920 } 2921 return retval; 2922 } 2923 2924 /* ADDIP 2925 * 3.2.4 Set Primary IP Address 2926 * 0 1 2 3 2927 * 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 2928 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2929 * | Type =0xC004 | Length = Variable | 2930 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2931 * | ASCONF-Request Correlation ID | 2932 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2933 * | Address Parameter | 2934 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2935 * 2936 * Create an ASCONF chunk with Set Primary IP address parameter. 2937 */ 2938 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2939 union sctp_addr *addr) 2940 { 2941 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2942 union sctp_addr_param addrparam; 2943 struct sctp_addip_param param; 2944 struct sctp_chunk *retval; 2945 int len = sizeof(param); 2946 int addrlen; 2947 2948 addrlen = af->to_addr_param(addr, &addrparam); 2949 if (!addrlen) 2950 return NULL; 2951 len += addrlen; 2952 2953 /* Create the chunk and make asconf header. */ 2954 retval = sctp_make_asconf(asoc, addr, len); 2955 if (!retval) 2956 return NULL; 2957 2958 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2959 param.param_hdr.length = htons(len); 2960 param.crr_id = 0; 2961 2962 sctp_addto_chunk(retval, sizeof(param), ¶m); 2963 sctp_addto_chunk(retval, addrlen, &addrparam); 2964 2965 return retval; 2966 } 2967 2968 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2969 * 0 1 2 3 2970 * 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 2971 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2972 * | Type = 0x80 | Chunk Flags | Chunk Length | 2973 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2974 * | Serial Number | 2975 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2976 * | ASCONF Parameter Response#1 | 2977 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2978 * \ \ 2979 * / .... / 2980 * \ \ 2981 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2982 * | ASCONF Parameter Response#N | 2983 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2984 * 2985 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2986 */ 2987 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2988 __u32 serial, int vparam_len) 2989 { 2990 struct sctp_addiphdr asconf; 2991 struct sctp_chunk *retval; 2992 int length = sizeof(asconf) + vparam_len; 2993 2994 /* Create the chunk. */ 2995 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length, 2996 GFP_ATOMIC); 2997 if (!retval) 2998 return NULL; 2999 3000 asconf.serial = htonl(serial); 3001 3002 retval->subh.addip_hdr = 3003 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 3004 3005 return retval; 3006 } 3007 3008 /* Add response parameters to an ASCONF_ACK chunk. */ 3009 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 3010 __be16 err_code, 3011 struct sctp_addip_param *asconf_param) 3012 { 3013 struct sctp_addip_param ack_param; 3014 struct sctp_errhdr err_param; 3015 int asconf_param_len = 0; 3016 int err_param_len = 0; 3017 __be16 response_type; 3018 3019 if (SCTP_ERROR_NO_ERROR == err_code) { 3020 response_type = SCTP_PARAM_SUCCESS_REPORT; 3021 } else { 3022 response_type = SCTP_PARAM_ERR_CAUSE; 3023 err_param_len = sizeof(err_param); 3024 if (asconf_param) 3025 asconf_param_len = 3026 ntohs(asconf_param->param_hdr.length); 3027 } 3028 3029 /* Add Success Indication or Error Cause Indication parameter. */ 3030 ack_param.param_hdr.type = response_type; 3031 ack_param.param_hdr.length = htons(sizeof(ack_param) + 3032 err_param_len + 3033 asconf_param_len); 3034 ack_param.crr_id = crr_id; 3035 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 3036 3037 if (SCTP_ERROR_NO_ERROR == err_code) 3038 return; 3039 3040 /* Add Error Cause parameter. */ 3041 err_param.cause = err_code; 3042 err_param.length = htons(err_param_len + asconf_param_len); 3043 sctp_addto_chunk(chunk, err_param_len, &err_param); 3044 3045 /* Add the failed TLV copied from ASCONF chunk. */ 3046 if (asconf_param) 3047 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 3048 } 3049 3050 /* Process a asconf parameter. */ 3051 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 3052 struct sctp_chunk *asconf, 3053 struct sctp_addip_param *asconf_param) 3054 { 3055 union sctp_addr_param *addr_param; 3056 struct sctp_transport *peer; 3057 union sctp_addr addr; 3058 struct sctp_af *af; 3059 3060 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 3061 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 3062 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 3063 return SCTP_ERROR_UNKNOWN_PARAM; 3064 3065 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3066 if (ntohs(addr_param->p.length) > 3067 ntohs(asconf_param->param_hdr.length) - sizeof(*asconf_param)) 3068 return SCTP_ERROR_PROTO_VIOLATION; 3069 3070 switch (addr_param->p.type) { 3071 case SCTP_PARAM_IPV6_ADDRESS: 3072 if (!asoc->peer.ipv6_address) 3073 return SCTP_ERROR_DNS_FAILED; 3074 break; 3075 case SCTP_PARAM_IPV4_ADDRESS: 3076 if (!asoc->peer.ipv4_address) 3077 return SCTP_ERROR_DNS_FAILED; 3078 break; 3079 default: 3080 return SCTP_ERROR_DNS_FAILED; 3081 } 3082 3083 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3084 if (unlikely(!af)) 3085 return SCTP_ERROR_DNS_FAILED; 3086 3087 if (!af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0)) 3088 return SCTP_ERROR_DNS_FAILED; 3089 3090 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3091 * or multicast address. 3092 * (note: wildcard is permitted and requires special handling so 3093 * make sure we check for that) 3094 */ 3095 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3096 return SCTP_ERROR_DNS_FAILED; 3097 3098 switch (asconf_param->param_hdr.type) { 3099 case SCTP_PARAM_ADD_IP: 3100 /* Section 4.2.1: 3101 * If the address 0.0.0.0 or ::0 is provided, the source 3102 * address of the packet MUST be added. 3103 */ 3104 if (af->is_any(&addr)) 3105 memcpy(&addr, &asconf->source, sizeof(addr)); 3106 3107 if (security_sctp_bind_connect(asoc->ep->base.sk, 3108 SCTP_PARAM_ADD_IP, 3109 (struct sockaddr *)&addr, 3110 af->sockaddr_len)) 3111 return SCTP_ERROR_REQ_REFUSED; 3112 3113 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3114 * request and does not have the local resources to add this 3115 * new address to the association, it MUST return an Error 3116 * Cause TLV set to the new error code 'Operation Refused 3117 * Due to Resource Shortage'. 3118 */ 3119 3120 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3121 if (!peer) 3122 return SCTP_ERROR_RSRC_LOW; 3123 3124 /* Start the heartbeat timer. */ 3125 sctp_transport_reset_hb_timer(peer); 3126 asoc->new_transport = peer; 3127 break; 3128 case SCTP_PARAM_DEL_IP: 3129 /* ADDIP 4.3 D7) If a request is received to delete the 3130 * last remaining IP address of a peer endpoint, the receiver 3131 * MUST send an Error Cause TLV with the error cause set to the 3132 * new error code 'Request to Delete Last Remaining IP Address'. 3133 */ 3134 if (asoc->peer.transport_count == 1) 3135 return SCTP_ERROR_DEL_LAST_IP; 3136 3137 /* ADDIP 4.3 D8) If a request is received to delete an IP 3138 * address which is also the source address of the IP packet 3139 * which contained the ASCONF chunk, the receiver MUST reject 3140 * this request. To reject the request the receiver MUST send 3141 * an Error Cause TLV set to the new error code 'Request to 3142 * Delete Source IP Address' 3143 */ 3144 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3145 return SCTP_ERROR_DEL_SRC_IP; 3146 3147 /* Section 4.2.2 3148 * If the address 0.0.0.0 or ::0 is provided, all 3149 * addresses of the peer except the source address of the 3150 * packet MUST be deleted. 3151 */ 3152 if (af->is_any(&addr)) { 3153 sctp_assoc_set_primary(asoc, asconf->transport); 3154 sctp_assoc_del_nonprimary_peers(asoc, 3155 asconf->transport); 3156 return SCTP_ERROR_NO_ERROR; 3157 } 3158 3159 /* If the address is not part of the association, the 3160 * ASCONF-ACK with Error Cause Indication Parameter 3161 * which including cause of Unresolvable Address should 3162 * be sent. 3163 */ 3164 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3165 if (!peer) 3166 return SCTP_ERROR_DNS_FAILED; 3167 3168 /* Don't free asconf->transport; a later wildcard DEL-IP 3169 * parameter reuses it. 3170 */ 3171 if (peer == asconf->transport) 3172 return SCTP_ERROR_REQ_REFUSED; 3173 3174 sctp_assoc_rm_peer(asoc, peer); 3175 break; 3176 case SCTP_PARAM_SET_PRIMARY: 3177 /* ADDIP Section 4.2.4 3178 * If the address 0.0.0.0 or ::0 is provided, the receiver 3179 * MAY mark the source address of the packet as its 3180 * primary. 3181 */ 3182 if (af->is_any(&addr)) 3183 memcpy(&addr, sctp_source(asconf), sizeof(addr)); 3184 3185 if (security_sctp_bind_connect(asoc->ep->base.sk, 3186 SCTP_PARAM_SET_PRIMARY, 3187 (struct sockaddr *)&addr, 3188 af->sockaddr_len)) 3189 return SCTP_ERROR_REQ_REFUSED; 3190 3191 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3192 if (!peer) 3193 return SCTP_ERROR_DNS_FAILED; 3194 3195 sctp_assoc_set_primary(asoc, peer); 3196 break; 3197 } 3198 3199 return SCTP_ERROR_NO_ERROR; 3200 } 3201 3202 /* Verify the ASCONF packet before we process it. */ 3203 bool sctp_verify_asconf(const struct sctp_association *asoc, 3204 struct sctp_chunk *chunk, bool addr_param_needed, 3205 struct sctp_paramhdr **errp) 3206 { 3207 struct sctp_addip_chunk *addip; 3208 bool addr_param_seen = false; 3209 union sctp_params param; 3210 3211 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr; 3212 sctp_walk_params(param, addip) { 3213 size_t length = ntohs(param.p->length); 3214 3215 *errp = param.p; 3216 switch (param.p->type) { 3217 case SCTP_PARAM_ERR_CAUSE: 3218 if (length < sizeof(struct sctp_addip_param) + 3219 sizeof(struct sctp_errhdr)) 3220 return false; 3221 break; 3222 case SCTP_PARAM_IPV4_ADDRESS: 3223 if (length != sizeof(struct sctp_ipv4addr_param)) 3224 return false; 3225 /* ensure there is only one addr param and it's in the 3226 * beginning of addip_hdr params, or we reject it. 3227 */ 3228 if (param.v != (addip + 1)) 3229 return false; 3230 addr_param_seen = true; 3231 break; 3232 case SCTP_PARAM_IPV6_ADDRESS: 3233 if (length != sizeof(struct sctp_ipv6addr_param)) 3234 return false; 3235 if (param.v != (addip + 1)) 3236 return false; 3237 addr_param_seen = true; 3238 break; 3239 case SCTP_PARAM_ADD_IP: 3240 case SCTP_PARAM_DEL_IP: 3241 case SCTP_PARAM_SET_PRIMARY: 3242 /* In ASCONF chunks, these need to be first. */ 3243 if (addr_param_needed && !addr_param_seen) 3244 return false; 3245 length = ntohs(param.addip->param_hdr.length); 3246 if (length < sizeof(struct sctp_addip_param) + 3247 sizeof(**errp)) 3248 return false; 3249 break; 3250 case SCTP_PARAM_SUCCESS_REPORT: 3251 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3252 if (length != sizeof(struct sctp_addip_param)) 3253 return false; 3254 break; 3255 default: 3256 /* This is unknown to us, reject! */ 3257 return false; 3258 } 3259 } 3260 3261 /* Remaining sanity checks. */ 3262 if (addr_param_needed && !addr_param_seen) 3263 return false; 3264 if (!addr_param_needed && addr_param_seen) 3265 return false; 3266 if (param.v != chunk->chunk_end) 3267 return false; 3268 3269 return true; 3270 } 3271 3272 /* Process an incoming ASCONF chunk with the next expected serial no. and 3273 * return an ASCONF_ACK chunk to be sent in response. 3274 */ 3275 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3276 struct sctp_chunk *asconf) 3277 { 3278 union sctp_addr_param *addr_param; 3279 struct sctp_addip_chunk *addip; 3280 struct sctp_chunk *asconf_ack; 3281 bool all_param_pass = true; 3282 struct sctp_addiphdr *hdr; 3283 int length = 0, chunk_len; 3284 union sctp_params param; 3285 __be16 err_code; 3286 __u32 serial; 3287 3288 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr; 3289 chunk_len = ntohs(asconf->chunk_hdr->length) - 3290 sizeof(struct sctp_chunkhdr); 3291 hdr = (struct sctp_addiphdr *)asconf->skb->data; 3292 serial = ntohl(hdr->serial); 3293 3294 /* Skip the addiphdr and store a pointer to address parameter. */ 3295 length = sizeof(*hdr); 3296 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3297 chunk_len -= length; 3298 3299 /* Skip the address parameter and store a pointer to the first 3300 * asconf parameter. 3301 */ 3302 length = ntohs(addr_param->p.length); 3303 chunk_len -= length; 3304 3305 /* create an ASCONF_ACK chunk. 3306 * Based on the definitions of parameters, we know that the size of 3307 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3308 * parameters. 3309 */ 3310 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3311 if (!asconf_ack) 3312 goto done; 3313 3314 /* Process the TLVs contained within the ASCONF chunk. */ 3315 sctp_walk_params(param, addip) { 3316 /* Skip preceding address parameters. */ 3317 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 3318 param.p->type == SCTP_PARAM_IPV6_ADDRESS) 3319 continue; 3320 3321 err_code = sctp_process_asconf_param(asoc, asconf, 3322 param.addip); 3323 /* ADDIP 4.1 A7) 3324 * If an error response is received for a TLV parameter, 3325 * all TLVs with no response before the failed TLV are 3326 * considered successful if not reported. All TLVs after 3327 * the failed response are considered unsuccessful unless 3328 * a specific success indication is present for the parameter. 3329 */ 3330 if (err_code != SCTP_ERROR_NO_ERROR) 3331 all_param_pass = false; 3332 if (!all_param_pass) 3333 sctp_add_asconf_response(asconf_ack, param.addip->crr_id, 3334 err_code, param.addip); 3335 3336 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3337 * an IP address sends an 'Out of Resource' in its response, it 3338 * MUST also fail any subsequent add or delete requests bundled 3339 * in the ASCONF. 3340 */ 3341 if (err_code == SCTP_ERROR_RSRC_LOW) 3342 goto done; 3343 } 3344 done: 3345 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3346 * after freeing the reference to old asconf ack if any. 3347 */ 3348 if (asconf_ack) { 3349 asoc->peer.addip_serial++; 3350 sctp_chunk_hold(asconf_ack); 3351 list_add_tail(&asconf_ack->transmitted_list, 3352 &asoc->asconf_ack_list); 3353 } 3354 3355 return asconf_ack; 3356 } 3357 3358 /* Process a asconf parameter that is successfully acked. */ 3359 static void sctp_asconf_param_success(struct sctp_association *asoc, 3360 struct sctp_addip_param *asconf_param) 3361 { 3362 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3363 union sctp_addr_param *addr_param; 3364 struct sctp_sockaddr_entry *saddr; 3365 struct sctp_transport *transport; 3366 union sctp_addr addr; 3367 struct sctp_af *af; 3368 3369 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3370 3371 /* We have checked the packet before, so we do not check again. */ 3372 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3373 if (!af->from_addr_param(&addr, addr_param, htons(bp->port), 0)) 3374 return; 3375 3376 switch (asconf_param->param_hdr.type) { 3377 case SCTP_PARAM_ADD_IP: 3378 /* This is always done in BH context with a socket lock 3379 * held, so the list can not change. 3380 */ 3381 local_bh_disable(); 3382 list_for_each_entry(saddr, &bp->address_list, list) { 3383 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3384 saddr->state = SCTP_ADDR_SRC; 3385 } 3386 local_bh_enable(); 3387 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3388 transports) { 3389 sctp_transport_dst_release(transport); 3390 } 3391 break; 3392 case SCTP_PARAM_DEL_IP: 3393 local_bh_disable(); 3394 sctp_del_bind_addr(bp, &addr); 3395 if (asoc->asconf_addr_del_pending != NULL && 3396 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3397 kfree(asoc->asconf_addr_del_pending); 3398 asoc->asconf_addr_del_pending = NULL; 3399 } 3400 local_bh_enable(); 3401 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3402 transports) { 3403 sctp_transport_dst_release(transport); 3404 } 3405 break; 3406 default: 3407 break; 3408 } 3409 } 3410 3411 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3412 * for the given asconf parameter. If there is no response for this parameter, 3413 * return the error code based on the third argument 'no_err'. 3414 * ADDIP 4.1 3415 * A7) If an error response is received for a TLV parameter, all TLVs with no 3416 * response before the failed TLV are considered successful if not reported. 3417 * All TLVs after the failed response are considered unsuccessful unless a 3418 * specific success indication is present for the parameter. 3419 */ 3420 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3421 struct sctp_addip_param *asconf_param, 3422 int no_err) 3423 { 3424 struct sctp_addip_param *asconf_ack_param; 3425 struct sctp_errhdr *err_param; 3426 int asconf_ack_len; 3427 __be16 err_code; 3428 int length; 3429 3430 if (no_err) 3431 err_code = SCTP_ERROR_NO_ERROR; 3432 else 3433 err_code = SCTP_ERROR_REQ_REFUSED; 3434 3435 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3436 sizeof(struct sctp_chunkhdr); 3437 3438 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3439 * the first asconf_ack parameter. 3440 */ 3441 length = sizeof(struct sctp_addiphdr); 3442 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data + 3443 length); 3444 asconf_ack_len -= length; 3445 3446 while (asconf_ack_len > 0) { 3447 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3448 switch (asconf_ack_param->param_hdr.type) { 3449 case SCTP_PARAM_SUCCESS_REPORT: 3450 return SCTP_ERROR_NO_ERROR; 3451 case SCTP_PARAM_ERR_CAUSE: 3452 length = sizeof(*asconf_ack_param); 3453 err_param = (void *)asconf_ack_param + length; 3454 return err_param->cause; 3455 default: 3456 return SCTP_ERROR_INV_PARAM; 3457 } 3458 } 3459 3460 length = ntohs(asconf_ack_param->param_hdr.length); 3461 asconf_ack_param = (void *)asconf_ack_param + SCTP_PAD4(length); 3462 asconf_ack_len -= SCTP_PAD4(length); 3463 } 3464 3465 return err_code; 3466 } 3467 3468 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3469 int sctp_process_asconf_ack(struct sctp_association *asoc, 3470 struct sctp_chunk *asconf_ack) 3471 { 3472 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3473 struct sctp_addip_param *asconf_param; 3474 __be16 err_code = SCTP_ERROR_NO_ERROR; 3475 union sctp_addr_param *addr_param; 3476 int asconf_len = asconf->skb->len; 3477 int all_param_pass = 0; 3478 int length = 0; 3479 int no_err = 1; 3480 int retval = 0; 3481 3482 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3483 * a pointer to address parameter. 3484 */ 3485 length = sizeof(struct sctp_addip_chunk); 3486 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3487 asconf_len -= length; 3488 3489 /* Skip the address parameter in the last asconf sent and store a 3490 * pointer to the first asconf parameter. 3491 */ 3492 length = ntohs(addr_param->p.length); 3493 asconf_param = (void *)addr_param + length; 3494 asconf_len -= length; 3495 3496 /* ADDIP 4.1 3497 * A8) If there is no response(s) to specific TLV parameter(s), and no 3498 * failures are indicated, then all request(s) are considered 3499 * successful. 3500 */ 3501 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr)) 3502 all_param_pass = 1; 3503 3504 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3505 while (asconf_len > 0) { 3506 if (all_param_pass) 3507 err_code = SCTP_ERROR_NO_ERROR; 3508 else { 3509 err_code = sctp_get_asconf_response(asconf_ack, 3510 asconf_param, 3511 no_err); 3512 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3513 no_err = 0; 3514 } 3515 3516 switch (err_code) { 3517 case SCTP_ERROR_NO_ERROR: 3518 sctp_asconf_param_success(asoc, asconf_param); 3519 break; 3520 3521 case SCTP_ERROR_RSRC_LOW: 3522 retval = 1; 3523 break; 3524 3525 case SCTP_ERROR_UNKNOWN_PARAM: 3526 /* Disable sending this type of asconf parameter in 3527 * future. 3528 */ 3529 asoc->peer.addip_disabled_mask |= 3530 asconf_param->param_hdr.type; 3531 break; 3532 3533 case SCTP_ERROR_REQ_REFUSED: 3534 case SCTP_ERROR_DEL_LAST_IP: 3535 case SCTP_ERROR_DEL_SRC_IP: 3536 default: 3537 break; 3538 } 3539 3540 /* Skip the processed asconf parameter and move to the next 3541 * one. 3542 */ 3543 length = ntohs(asconf_param->param_hdr.length); 3544 asconf_param = (void *)asconf_param + length; 3545 asconf_len -= length; 3546 } 3547 3548 if (no_err && asoc->src_out_of_asoc_ok) { 3549 asoc->src_out_of_asoc_ok = 0; 3550 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3551 } 3552 3553 /* Free the cached last sent asconf chunk. */ 3554 list_del_init(&asconf->transmitted_list); 3555 sctp_chunk_free(asconf); 3556 asoc->addip_last_asconf = NULL; 3557 3558 return retval; 3559 } 3560 3561 /* Make a FWD TSN chunk. */ 3562 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3563 __u32 new_cum_tsn, size_t nstreams, 3564 struct sctp_fwdtsn_skip *skiplist) 3565 { 3566 struct sctp_chunk *retval = NULL; 3567 struct sctp_fwdtsn_hdr ftsn_hdr; 3568 struct sctp_fwdtsn_skip skip; 3569 size_t hint; 3570 int i; 3571 3572 hint = (nstreams + 1) * sizeof(__u32); 3573 3574 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC); 3575 3576 if (!retval) 3577 return NULL; 3578 3579 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3580 retval->subh.fwdtsn_hdr = 3581 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3582 3583 for (i = 0; i < nstreams; i++) { 3584 skip.stream = skiplist[i].stream; 3585 skip.ssn = skiplist[i].ssn; 3586 sctp_addto_chunk(retval, sizeof(skip), &skip); 3587 } 3588 3589 return retval; 3590 } 3591 3592 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc, 3593 __u32 new_cum_tsn, size_t nstreams, 3594 struct sctp_ifwdtsn_skip *skiplist) 3595 { 3596 struct sctp_chunk *retval = NULL; 3597 struct sctp_ifwdtsn_hdr ftsn_hdr; 3598 size_t hint; 3599 3600 hint = (nstreams + 1) * sizeof(__u32); 3601 3602 retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint, 3603 GFP_ATOMIC); 3604 if (!retval) 3605 return NULL; 3606 3607 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3608 retval->subh.ifwdtsn_hdr = 3609 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3610 3611 sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist); 3612 3613 return retval; 3614 } 3615 3616 /* RE-CONFIG 3.1 (RE-CONFIG chunk) 3617 * 0 1 2 3 3618 * 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 3619 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3620 * | Type = 130 | Chunk Flags | Chunk Length | 3621 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3622 * \ \ 3623 * / Re-configuration Parameter / 3624 * \ \ 3625 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3626 * \ \ 3627 * / Re-configuration Parameter (optional) / 3628 * \ \ 3629 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3630 */ 3631 static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc, 3632 int length) 3633 { 3634 struct sctp_reconf_chunk *reconf; 3635 struct sctp_chunk *retval; 3636 3637 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length, 3638 GFP_ATOMIC); 3639 if (!retval) 3640 return NULL; 3641 3642 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr; 3643 retval->param_hdr.v = (u8 *)(reconf + 1); 3644 3645 return retval; 3646 } 3647 3648 /* RE-CONFIG 4.1 (STREAM OUT RESET) 3649 * 0 1 2 3 3650 * 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 3651 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3652 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N | 3653 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3654 * | Re-configuration Request Sequence Number | 3655 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3656 * | Re-configuration Response Sequence Number | 3657 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3658 * | Sender's Last Assigned TSN | 3659 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3660 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3661 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3662 * / ...... / 3663 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3664 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3665 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3666 * 3667 * RE-CONFIG 4.2 (STREAM IN RESET) 3668 * 0 1 2 3 3669 * 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 3670 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3671 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N | 3672 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3673 * | Re-configuration Request Sequence Number | 3674 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3675 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3676 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3677 * / ...... / 3678 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3679 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3680 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3681 */ 3682 struct sctp_chunk *sctp_make_strreset_req( 3683 const struct sctp_association *asoc, 3684 __u16 stream_num, __be16 *stream_list, 3685 bool out, bool in) 3686 { 3687 __u16 stream_len = stream_num * sizeof(__u16); 3688 struct sctp_strreset_outreq outreq; 3689 struct sctp_strreset_inreq inreq; 3690 struct sctp_chunk *retval; 3691 __u16 outlen, inlen; 3692 3693 outlen = (sizeof(outreq) + stream_len) * out; 3694 inlen = (sizeof(inreq) + stream_len) * in; 3695 3696 retval = sctp_make_reconf(asoc, SCTP_PAD4(outlen) + SCTP_PAD4(inlen)); 3697 if (!retval) 3698 return NULL; 3699 3700 if (outlen) { 3701 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST; 3702 outreq.param_hdr.length = htons(outlen); 3703 outreq.request_seq = htonl(asoc->strreset_outseq); 3704 outreq.response_seq = htonl(asoc->strreset_inseq - 1); 3705 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1); 3706 3707 sctp_addto_chunk(retval, sizeof(outreq), &outreq); 3708 3709 if (stream_len) 3710 sctp_addto_chunk(retval, stream_len, stream_list); 3711 } 3712 3713 if (inlen) { 3714 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST; 3715 inreq.param_hdr.length = htons(inlen); 3716 inreq.request_seq = htonl(asoc->strreset_outseq + out); 3717 3718 sctp_addto_chunk(retval, sizeof(inreq), &inreq); 3719 3720 if (stream_len) 3721 sctp_addto_chunk(retval, stream_len, stream_list); 3722 } 3723 3724 return retval; 3725 } 3726 3727 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL) 3728 * 0 1 2 3 3729 * 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 3730 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3731 * | Parameter Type = 15 | Parameter Length = 8 | 3732 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3733 * | Re-configuration Request Sequence Number | 3734 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3735 */ 3736 struct sctp_chunk *sctp_make_strreset_tsnreq( 3737 const struct sctp_association *asoc) 3738 { 3739 struct sctp_strreset_tsnreq tsnreq; 3740 __u16 length = sizeof(tsnreq); 3741 struct sctp_chunk *retval; 3742 3743 retval = sctp_make_reconf(asoc, length); 3744 if (!retval) 3745 return NULL; 3746 3747 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST; 3748 tsnreq.param_hdr.length = htons(length); 3749 tsnreq.request_seq = htonl(asoc->strreset_outseq); 3750 3751 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq); 3752 3753 return retval; 3754 } 3755 3756 /* RE-CONFIG 4.5/4.6 (ADD STREAM) 3757 * 0 1 2 3 3758 * 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 3759 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3760 * | Parameter Type = 17 | Parameter Length = 12 | 3761 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3762 * | Re-configuration Request Sequence Number | 3763 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3764 * | Number of new streams | Reserved | 3765 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3766 */ 3767 struct sctp_chunk *sctp_make_strreset_addstrm( 3768 const struct sctp_association *asoc, 3769 __u16 out, __u16 in) 3770 { 3771 struct sctp_strreset_addstrm addstrm; 3772 __u16 size = sizeof(addstrm); 3773 struct sctp_chunk *retval; 3774 3775 retval = sctp_make_reconf(asoc, (!!out + !!in) * size); 3776 if (!retval) 3777 return NULL; 3778 3779 if (out) { 3780 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS; 3781 addstrm.param_hdr.length = htons(size); 3782 addstrm.number_of_streams = htons(out); 3783 addstrm.request_seq = htonl(asoc->strreset_outseq); 3784 addstrm.reserved = 0; 3785 3786 sctp_addto_chunk(retval, size, &addstrm); 3787 } 3788 3789 if (in) { 3790 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS; 3791 addstrm.param_hdr.length = htons(size); 3792 addstrm.number_of_streams = htons(in); 3793 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out); 3794 addstrm.reserved = 0; 3795 3796 sctp_addto_chunk(retval, size, &addstrm); 3797 } 3798 3799 return retval; 3800 } 3801 3802 /* RE-CONFIG 4.4 (RESP) 3803 * 0 1 2 3 3804 * 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 3805 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3806 * | Parameter Type = 16 | Parameter Length | 3807 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3808 * | Re-configuration Response Sequence Number | 3809 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3810 * | Result | 3811 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3812 */ 3813 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc, 3814 __u32 result, __u32 sn) 3815 { 3816 struct sctp_strreset_resp resp; 3817 __u16 length = sizeof(resp); 3818 struct sctp_chunk *retval; 3819 3820 retval = sctp_make_reconf(asoc, length); 3821 if (!retval) 3822 return NULL; 3823 3824 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3825 resp.param_hdr.length = htons(length); 3826 resp.response_seq = htonl(sn); 3827 resp.result = htonl(result); 3828 3829 sctp_addto_chunk(retval, sizeof(resp), &resp); 3830 3831 return retval; 3832 } 3833 3834 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP) 3835 * 0 1 2 3 3836 * 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 3837 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3838 * | Parameter Type = 16 | Parameter Length | 3839 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3840 * | Re-configuration Response Sequence Number | 3841 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3842 * | Result | 3843 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3844 * | Sender's Next TSN (optional) | 3845 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3846 * | Receiver's Next TSN (optional) | 3847 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3848 */ 3849 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc, 3850 __u32 result, __u32 sn, 3851 __u32 sender_tsn, 3852 __u32 receiver_tsn) 3853 { 3854 struct sctp_strreset_resptsn tsnresp; 3855 __u16 length = sizeof(tsnresp); 3856 struct sctp_chunk *retval; 3857 3858 retval = sctp_make_reconf(asoc, length); 3859 if (!retval) 3860 return NULL; 3861 3862 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3863 tsnresp.param_hdr.length = htons(length); 3864 3865 tsnresp.response_seq = htonl(sn); 3866 tsnresp.result = htonl(result); 3867 tsnresp.senders_next_tsn = htonl(sender_tsn); 3868 tsnresp.receivers_next_tsn = htonl(receiver_tsn); 3869 3870 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp); 3871 3872 return retval; 3873 } 3874 3875 bool sctp_verify_reconf(const struct sctp_association *asoc, 3876 struct sctp_chunk *chunk, 3877 struct sctp_paramhdr **errp) 3878 { 3879 struct sctp_reconf_chunk *hdr; 3880 union sctp_params param; 3881 __be16 last = 0; 3882 __u16 cnt = 0; 3883 3884 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; 3885 sctp_walk_params(param, hdr) { 3886 __u16 length = ntohs(param.p->length); 3887 3888 *errp = param.p; 3889 if (cnt++ > 2) 3890 return false; 3891 switch (param.p->type) { 3892 case SCTP_PARAM_RESET_OUT_REQUEST: 3893 if (length < sizeof(struct sctp_strreset_outreq) || 3894 (last && last != SCTP_PARAM_RESET_RESPONSE && 3895 last != SCTP_PARAM_RESET_IN_REQUEST)) 3896 return false; 3897 break; 3898 case SCTP_PARAM_RESET_IN_REQUEST: 3899 if (length < sizeof(struct sctp_strreset_inreq) || 3900 (last && last != SCTP_PARAM_RESET_OUT_REQUEST)) 3901 return false; 3902 break; 3903 case SCTP_PARAM_RESET_RESPONSE: 3904 if ((length != sizeof(struct sctp_strreset_resp) && 3905 length != sizeof(struct sctp_strreset_resptsn)) || 3906 (last && last != SCTP_PARAM_RESET_RESPONSE && 3907 last != SCTP_PARAM_RESET_OUT_REQUEST)) 3908 return false; 3909 break; 3910 case SCTP_PARAM_RESET_TSN_REQUEST: 3911 if (length != 3912 sizeof(struct sctp_strreset_tsnreq) || last) 3913 return false; 3914 break; 3915 case SCTP_PARAM_RESET_ADD_IN_STREAMS: 3916 if (length != sizeof(struct sctp_strreset_addstrm) || 3917 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS)) 3918 return false; 3919 break; 3920 case SCTP_PARAM_RESET_ADD_OUT_STREAMS: 3921 if (length != sizeof(struct sctp_strreset_addstrm) || 3922 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS)) 3923 return false; 3924 break; 3925 default: 3926 return false; 3927 } 3928 3929 last = param.p->type; 3930 } 3931 3932 return true; 3933 } 3934