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