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/hash.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 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 goto nodata; 1679 1680 cookie = (struct sctp_signed_cookie *) retval->body; 1681 1682 /* Set up the parameter header. */ 1683 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1684 retval->p.length = htons(*cookie_len); 1685 1686 /* Copy the cookie part of the association itself. */ 1687 cookie->c = asoc->c; 1688 /* Save the raw address list length in the cookie. */ 1689 cookie->c.raw_addr_list_len = addrs_len; 1690 1691 /* Remember PR-SCTP capability. */ 1692 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1693 1694 /* Save adaptation indication in the cookie. */ 1695 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1696 1697 /* Set an expiration time for the cookie. */ 1698 cookie->c.expiration = ktime_add(asoc->cookie_life, 1699 ktime_get_real()); 1700 1701 /* Copy the peer's init packet. */ 1702 memcpy(cookie + 1, init_chunk->chunk_hdr, 1703 ntohs(init_chunk->chunk_hdr->length)); 1704 1705 /* Copy the raw local address list of the association. */ 1706 memcpy((__u8 *)(cookie + 1) + 1707 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1708 1709 if (sctp_sk(ep->base.sk)->hmac) { 1710 struct crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac; 1711 int err; 1712 1713 /* Sign the message. */ 1714 err = crypto_shash_setkey(tfm, ep->secret_key, 1715 sizeof(ep->secret_key)) ?: 1716 crypto_shash_tfm_digest(tfm, (u8 *)&cookie->c, bodysize, 1717 cookie->signature); 1718 if (err) 1719 goto free_cookie; 1720 } 1721 1722 return retval; 1723 1724 free_cookie: 1725 kfree(retval); 1726 nodata: 1727 *cookie_len = 0; 1728 return NULL; 1729 } 1730 1731 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1732 struct sctp_association *sctp_unpack_cookie( 1733 const struct sctp_endpoint *ep, 1734 const struct sctp_association *asoc, 1735 struct sctp_chunk *chunk, gfp_t gfp, 1736 int *error, struct sctp_chunk **errp) 1737 { 1738 struct sctp_association *retval = NULL; 1739 int headersize, bodysize, fixed_size; 1740 struct sctp_signed_cookie *cookie; 1741 struct sk_buff *skb = chunk->skb; 1742 struct sctp_cookie *bear_cookie; 1743 __u8 *digest = ep->digest; 1744 enum sctp_scope scope; 1745 unsigned int len; 1746 ktime_t kt; 1747 1748 /* Header size is static data prior to the actual cookie, including 1749 * any padding. 1750 */ 1751 headersize = sizeof(struct sctp_chunkhdr) + 1752 (sizeof(struct sctp_signed_cookie) - 1753 sizeof(struct sctp_cookie)); 1754 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1755 fixed_size = headersize + sizeof(struct sctp_cookie); 1756 1757 /* Verify that the chunk looks like it even has a cookie. 1758 * There must be enough room for our cookie and our peer's 1759 * INIT chunk. 1760 */ 1761 len = ntohs(chunk->chunk_hdr->length); 1762 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1763 goto malformed; 1764 1765 /* Verify that the cookie has been padded out. */ 1766 if (bodysize % SCTP_COOKIE_MULTIPLE) 1767 goto malformed; 1768 1769 /* Process the cookie. */ 1770 cookie = chunk->subh.cookie_hdr; 1771 bear_cookie = &cookie->c; 1772 1773 if (!sctp_sk(ep->base.sk)->hmac) 1774 goto no_hmac; 1775 1776 /* Check the signature. */ 1777 { 1778 struct crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac; 1779 int err; 1780 1781 err = crypto_shash_setkey(tfm, ep->secret_key, 1782 sizeof(ep->secret_key)) ?: 1783 crypto_shash_tfm_digest(tfm, (u8 *)bear_cookie, bodysize, 1784 digest); 1785 if (err) { 1786 *error = -SCTP_IERROR_NOMEM; 1787 goto fail; 1788 } 1789 } 1790 1791 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1792 *error = -SCTP_IERROR_BAD_SIG; 1793 goto fail; 1794 } 1795 1796 no_hmac: 1797 /* IG Section 2.35.2: 1798 * 3) Compare the port numbers and the verification tag contained 1799 * within the COOKIE ECHO chunk to the actual port numbers and the 1800 * verification tag within the SCTP common header of the received 1801 * packet. If these values do not match the packet MUST be silently 1802 * discarded, 1803 */ 1804 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1805 *error = -SCTP_IERROR_BAD_TAG; 1806 goto fail; 1807 } 1808 1809 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1810 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1811 *error = -SCTP_IERROR_BAD_PORTS; 1812 goto fail; 1813 } 1814 1815 /* Check to see if the cookie is stale. If there is already 1816 * an association, there is no need to check cookie's expiration 1817 * for init collision case of lost COOKIE ACK. 1818 * If skb has been timestamped, then use the stamp, otherwise 1819 * use current time. This introduces a small possibility that 1820 * a cookie may be considered expired, but this would only slow 1821 * down the new association establishment instead of every packet. 1822 */ 1823 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1824 kt = skb_get_ktime(skb); 1825 else 1826 kt = ktime_get_real(); 1827 1828 if (!asoc && ktime_before(bear_cookie->expiration, kt)) { 1829 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); 1830 __be32 n = htonl(usecs); 1831 1832 /* 1833 * Section 3.3.10.3 Stale Cookie Error (3) 1834 * 1835 * Cause of error 1836 * --------------- 1837 * Stale Cookie Error: Indicates the receipt of a valid State 1838 * Cookie that has expired. 1839 */ 1840 *errp = sctp_make_op_error(asoc, chunk, 1841 SCTP_ERROR_STALE_COOKIE, &n, 1842 sizeof(n), 0); 1843 if (*errp) 1844 *error = -SCTP_IERROR_STALE_COOKIE; 1845 else 1846 *error = -SCTP_IERROR_NOMEM; 1847 1848 goto fail; 1849 } 1850 1851 /* Make a new base association. */ 1852 scope = sctp_scope(sctp_source(chunk)); 1853 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1854 if (!retval) { 1855 *error = -SCTP_IERROR_NOMEM; 1856 goto fail; 1857 } 1858 1859 /* Set up our peer's port number. */ 1860 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1861 1862 /* Populate the association from the cookie. */ 1863 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1864 1865 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1866 GFP_ATOMIC) < 0) { 1867 *error = -SCTP_IERROR_NOMEM; 1868 goto fail; 1869 } 1870 1871 /* Also, add the destination address. */ 1872 if (list_empty(&retval->base.bind_addr.address_list)) { 1873 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1874 sizeof(chunk->dest), SCTP_ADDR_SRC, 1875 GFP_ATOMIC); 1876 } 1877 1878 retval->next_tsn = retval->c.initial_tsn; 1879 retval->ctsn_ack_point = retval->next_tsn - 1; 1880 retval->addip_serial = retval->c.initial_tsn; 1881 retval->strreset_outseq = retval->c.initial_tsn; 1882 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1883 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1884 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1885 1886 /* The INIT stuff will be done by the side effects. */ 1887 return retval; 1888 1889 fail: 1890 if (retval) 1891 sctp_association_free(retval); 1892 1893 return NULL; 1894 1895 malformed: 1896 /* Yikes! The packet is either corrupt or deliberately 1897 * malformed. 1898 */ 1899 *error = -SCTP_IERROR_MALFORMED; 1900 goto fail; 1901 } 1902 1903 /******************************************************************** 1904 * 3rd Level Abstractions 1905 ********************************************************************/ 1906 1907 struct __sctp_missing { 1908 __be32 num_missing; 1909 __be16 type; 1910 } __packed; 1911 1912 /* 1913 * Report a missing mandatory parameter. 1914 */ 1915 static int sctp_process_missing_param(const struct sctp_association *asoc, 1916 enum sctp_param paramtype, 1917 struct sctp_chunk *chunk, 1918 struct sctp_chunk **errp) 1919 { 1920 struct __sctp_missing report; 1921 __u16 len; 1922 1923 len = SCTP_PAD4(sizeof(report)); 1924 1925 /* Make an ERROR chunk, preparing enough room for 1926 * returning multiple unknown parameters. 1927 */ 1928 if (!*errp) 1929 *errp = sctp_make_op_error_space(asoc, chunk, len); 1930 1931 if (*errp) { 1932 report.num_missing = htonl(1); 1933 report.type = paramtype; 1934 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1935 sizeof(report)); 1936 sctp_addto_chunk(*errp, sizeof(report), &report); 1937 } 1938 1939 /* Stop processing this chunk. */ 1940 return 0; 1941 } 1942 1943 /* Report an Invalid Mandatory Parameter. */ 1944 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1945 struct sctp_chunk *chunk, 1946 struct sctp_chunk **errp) 1947 { 1948 /* Invalid Mandatory Parameter Error has no payload. */ 1949 1950 if (!*errp) 1951 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1952 1953 if (*errp) 1954 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1955 1956 /* Stop processing this chunk. */ 1957 return 0; 1958 } 1959 1960 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1961 struct sctp_paramhdr *param, 1962 const struct sctp_chunk *chunk, 1963 struct sctp_chunk **errp) 1964 { 1965 /* This is a fatal error. Any accumulated non-fatal errors are 1966 * not reported. 1967 */ 1968 if (*errp) 1969 sctp_chunk_free(*errp); 1970 1971 /* Create an error chunk and fill it in with our payload. */ 1972 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1973 1974 return 0; 1975 } 1976 1977 1978 /* Do not attempt to handle the HOST_NAME parm. However, do 1979 * send back an indicator to the peer. 1980 */ 1981 static int sctp_process_hn_param(const struct sctp_association *asoc, 1982 union sctp_params param, 1983 struct sctp_chunk *chunk, 1984 struct sctp_chunk **errp) 1985 { 1986 __u16 len = ntohs(param.p->length); 1987 1988 /* Processing of the HOST_NAME parameter will generate an 1989 * ABORT. If we've accumulated any non-fatal errors, they 1990 * would be unrecognized parameters and we should not include 1991 * them in the ABORT. 1992 */ 1993 if (*errp) 1994 sctp_chunk_free(*errp); 1995 1996 *errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_DNS_FAILED, 1997 param.v, len, 0); 1998 1999 /* Stop processing this chunk. */ 2000 return 0; 2001 } 2002 2003 static int sctp_verify_ext_param(struct net *net, 2004 const struct sctp_endpoint *ep, 2005 union sctp_params param) 2006 { 2007 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2008 int have_asconf = 0; 2009 int have_auth = 0; 2010 int i; 2011 2012 for (i = 0; i < num_ext; i++) { 2013 switch (param.ext->chunks[i]) { 2014 case SCTP_CID_AUTH: 2015 have_auth = 1; 2016 break; 2017 case SCTP_CID_ASCONF: 2018 case SCTP_CID_ASCONF_ACK: 2019 have_asconf = 1; 2020 break; 2021 } 2022 } 2023 2024 /* ADD-IP Security: The draft requires us to ABORT or ignore the 2025 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 2026 * only if ADD-IP is turned on and we are not backward-compatible 2027 * mode. 2028 */ 2029 if (net->sctp.addip_noauth) 2030 return 1; 2031 2032 if (ep->asconf_enable && !have_auth && have_asconf) 2033 return 0; 2034 2035 return 1; 2036 } 2037 2038 static void sctp_process_ext_param(struct sctp_association *asoc, 2039 union sctp_params param) 2040 { 2041 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2042 int i; 2043 2044 for (i = 0; i < num_ext; i++) { 2045 switch (param.ext->chunks[i]) { 2046 case SCTP_CID_RECONF: 2047 if (asoc->ep->reconf_enable) 2048 asoc->peer.reconf_capable = 1; 2049 break; 2050 case SCTP_CID_FWD_TSN: 2051 if (asoc->ep->prsctp_enable) 2052 asoc->peer.prsctp_capable = 1; 2053 break; 2054 case SCTP_CID_AUTH: 2055 /* if the peer reports AUTH, assume that he 2056 * supports AUTH. 2057 */ 2058 if (asoc->ep->auth_enable) 2059 asoc->peer.auth_capable = 1; 2060 break; 2061 case SCTP_CID_ASCONF: 2062 case SCTP_CID_ASCONF_ACK: 2063 if (asoc->ep->asconf_enable) 2064 asoc->peer.asconf_capable = 1; 2065 break; 2066 case SCTP_CID_I_DATA: 2067 if (asoc->ep->intl_enable) 2068 asoc->peer.intl_capable = 1; 2069 break; 2070 default: 2071 break; 2072 } 2073 } 2074 } 2075 2076 /* RFC 3.2.1 & the Implementers Guide 2.2. 2077 * 2078 * The Parameter Types are encoded such that the 2079 * highest-order two bits specify the action that must be 2080 * taken if the processing endpoint does not recognize the 2081 * Parameter Type. 2082 * 2083 * 00 - Stop processing this parameter; do not process any further 2084 * parameters within this chunk 2085 * 2086 * 01 - Stop processing this parameter, do not process any further 2087 * parameters within this chunk, and report the unrecognized 2088 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2089 * 2090 * 10 - Skip this parameter and continue processing. 2091 * 2092 * 11 - Skip this parameter and continue processing but 2093 * report the unrecognized parameter in an 2094 * 'Unrecognized Parameter' ERROR chunk. 2095 * 2096 * Return value: 2097 * SCTP_IERROR_NO_ERROR - continue with the chunk 2098 * SCTP_IERROR_ERROR - stop and report an error. 2099 * SCTP_IERROR_NOMEME - out of memory. 2100 */ 2101 static enum sctp_ierror sctp_process_unk_param( 2102 const struct sctp_association *asoc, 2103 union sctp_params param, 2104 struct sctp_chunk *chunk, 2105 struct sctp_chunk **errp) 2106 { 2107 int retval = SCTP_IERROR_NO_ERROR; 2108 2109 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2110 case SCTP_PARAM_ACTION_DISCARD: 2111 retval = SCTP_IERROR_ERROR; 2112 break; 2113 case SCTP_PARAM_ACTION_SKIP: 2114 break; 2115 case SCTP_PARAM_ACTION_DISCARD_ERR: 2116 retval = SCTP_IERROR_ERROR; 2117 fallthrough; 2118 case SCTP_PARAM_ACTION_SKIP_ERR: 2119 /* Make an ERROR chunk, preparing enough room for 2120 * returning multiple unknown parameters. 2121 */ 2122 if (!*errp) { 2123 *errp = sctp_make_op_error_limited(asoc, chunk); 2124 if (!*errp) { 2125 /* If there is no memory for generating the 2126 * ERROR report as specified, an ABORT will be 2127 * triggered to the peer and the association 2128 * won't be established. 2129 */ 2130 retval = SCTP_IERROR_NOMEM; 2131 break; 2132 } 2133 } 2134 2135 if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2136 ntohs(param.p->length))) 2137 sctp_addto_chunk(*errp, ntohs(param.p->length), 2138 param.v); 2139 break; 2140 default: 2141 break; 2142 } 2143 2144 return retval; 2145 } 2146 2147 /* Verify variable length parameters 2148 * Return values: 2149 * SCTP_IERROR_ABORT - trigger an ABORT 2150 * SCTP_IERROR_NOMEM - out of memory (abort) 2151 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2152 * SCTP_IERROR_NO_ERROR - continue with the chunk 2153 */ 2154 static enum sctp_ierror sctp_verify_param(struct net *net, 2155 const struct sctp_endpoint *ep, 2156 const struct sctp_association *asoc, 2157 union sctp_params param, 2158 enum sctp_cid cid, 2159 struct sctp_chunk *chunk, 2160 struct sctp_chunk **err_chunk) 2161 { 2162 struct sctp_hmac_algo_param *hmacs; 2163 int retval = SCTP_IERROR_NO_ERROR; 2164 __u16 n_elt, id = 0; 2165 int i; 2166 2167 /* FIXME - This routine is not looking at each parameter per the 2168 * chunk type, i.e., unrecognized parameters should be further 2169 * identified based on the chunk id. 2170 */ 2171 2172 switch (param.p->type) { 2173 case SCTP_PARAM_IPV4_ADDRESS: 2174 case SCTP_PARAM_IPV6_ADDRESS: 2175 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2176 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2177 case SCTP_PARAM_STATE_COOKIE: 2178 case SCTP_PARAM_HEARTBEAT_INFO: 2179 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2180 case SCTP_PARAM_ECN_CAPABLE: 2181 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2182 break; 2183 2184 case SCTP_PARAM_SUPPORTED_EXT: 2185 if (!sctp_verify_ext_param(net, ep, param)) 2186 return SCTP_IERROR_ABORT; 2187 break; 2188 2189 case SCTP_PARAM_SET_PRIMARY: 2190 if (!ep->asconf_enable) 2191 goto unhandled; 2192 2193 if (ntohs(param.p->length) < sizeof(struct sctp_addip_param) + 2194 sizeof(struct sctp_paramhdr)) { 2195 sctp_process_inv_paramlength(asoc, param.p, 2196 chunk, err_chunk); 2197 retval = SCTP_IERROR_ABORT; 2198 } 2199 break; 2200 2201 case SCTP_PARAM_HOST_NAME_ADDRESS: 2202 /* This param has been Deprecated, send ABORT. */ 2203 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2204 retval = SCTP_IERROR_ABORT; 2205 break; 2206 2207 case SCTP_PARAM_FWD_TSN_SUPPORT: 2208 if (ep->prsctp_enable) 2209 break; 2210 goto unhandled; 2211 2212 case SCTP_PARAM_RANDOM: 2213 if (!ep->auth_enable) 2214 goto unhandled; 2215 2216 /* SCTP-AUTH: Secion 6.1 2217 * If the random number is not 32 byte long the association 2218 * MUST be aborted. The ABORT chunk SHOULD contain the error 2219 * cause 'Protocol Violation'. 2220 */ 2221 if (SCTP_AUTH_RANDOM_LENGTH != ntohs(param.p->length) - 2222 sizeof(struct sctp_paramhdr)) { 2223 sctp_process_inv_paramlength(asoc, param.p, 2224 chunk, err_chunk); 2225 retval = SCTP_IERROR_ABORT; 2226 } 2227 break; 2228 2229 case SCTP_PARAM_CHUNKS: 2230 if (!ep->auth_enable) 2231 goto unhandled; 2232 2233 /* SCTP-AUTH: Section 3.2 2234 * The CHUNKS parameter MUST be included once in the INIT or 2235 * INIT-ACK chunk if the sender wants to receive authenticated 2236 * chunks. Its maximum length is 260 bytes. 2237 */ 2238 if (260 < ntohs(param.p->length)) { 2239 sctp_process_inv_paramlength(asoc, param.p, 2240 chunk, err_chunk); 2241 retval = SCTP_IERROR_ABORT; 2242 } 2243 break; 2244 2245 case SCTP_PARAM_HMAC_ALGO: 2246 if (!ep->auth_enable) 2247 goto unhandled; 2248 2249 hmacs = (struct sctp_hmac_algo_param *)param.p; 2250 n_elt = (ntohs(param.p->length) - 2251 sizeof(struct sctp_paramhdr)) >> 1; 2252 2253 /* SCTP-AUTH: Section 6.1 2254 * The HMAC algorithm based on SHA-1 MUST be supported and 2255 * included in the HMAC-ALGO parameter. 2256 */ 2257 for (i = 0; i < n_elt; i++) { 2258 id = ntohs(hmacs->hmac_ids[i]); 2259 2260 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2261 break; 2262 } 2263 2264 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2265 sctp_process_inv_paramlength(asoc, param.p, chunk, 2266 err_chunk); 2267 retval = SCTP_IERROR_ABORT; 2268 } 2269 break; 2270 unhandled: 2271 default: 2272 pr_debug("%s: unrecognized param:%d for chunk:%d\n", 2273 __func__, ntohs(param.p->type), cid); 2274 2275 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2276 break; 2277 } 2278 return retval; 2279 } 2280 2281 /* Verify the INIT packet before we process it. */ 2282 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 2283 const struct sctp_association *asoc, enum sctp_cid cid, 2284 struct sctp_init_chunk *peer_init, 2285 struct sctp_chunk *chunk, struct sctp_chunk **errp) 2286 { 2287 union sctp_params param; 2288 bool has_cookie = false; 2289 int result; 2290 2291 /* Check for missing mandatory parameters. Note: Initial TSN is 2292 * also mandatory, but is not checked here since the valid range 2293 * is 0..2**32-1. RFC4960, section 3.3.3. 2294 */ 2295 if (peer_init->init_hdr.num_outbound_streams == 0 || 2296 peer_init->init_hdr.num_inbound_streams == 0 || 2297 peer_init->init_hdr.init_tag == 0 || 2298 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) 2299 return sctp_process_inv_mandatory(asoc, chunk, errp); 2300 2301 sctp_walk_params(param, peer_init) { 2302 if (param.p->type == SCTP_PARAM_STATE_COOKIE) 2303 has_cookie = true; 2304 } 2305 2306 /* There is a possibility that a parameter length was bad and 2307 * in that case we would have stoped walking the parameters. 2308 * The current param.p would point at the bad one. 2309 * Current consensus on the mailing list is to generate a PROTOCOL 2310 * VIOLATION error. We build the ERROR chunk here and let the normal 2311 * error handling code build and send the packet. 2312 */ 2313 if (param.v != (void *)chunk->chunk_end) 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 2657 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 2658 if (!af) 2659 break; 2660 2661 if (!af->from_addr_param(&addr, addr_param, 2662 htons(asoc->peer.port), 0)) 2663 break; 2664 2665 if (!af->addr_valid(&addr, NULL, NULL)) 2666 break; 2667 2668 t = sctp_assoc_lookup_paddr(asoc, &addr); 2669 if (!t) 2670 break; 2671 2672 sctp_assoc_set_primary(asoc, t); 2673 break; 2674 2675 case SCTP_PARAM_SUPPORTED_EXT: 2676 sctp_process_ext_param(asoc, param); 2677 break; 2678 2679 case SCTP_PARAM_FWD_TSN_SUPPORT: 2680 if (asoc->ep->prsctp_enable) { 2681 asoc->peer.prsctp_capable = 1; 2682 break; 2683 } 2684 /* Fall Through */ 2685 goto fall_through; 2686 2687 case SCTP_PARAM_RANDOM: 2688 if (!ep->auth_enable) 2689 goto fall_through; 2690 2691 /* Save peer's random parameter */ 2692 kfree(asoc->peer.peer_random); 2693 asoc->peer.peer_random = kmemdup(param.p, 2694 ntohs(param.p->length), gfp); 2695 if (!asoc->peer.peer_random) { 2696 retval = 0; 2697 break; 2698 } 2699 break; 2700 2701 case SCTP_PARAM_HMAC_ALGO: 2702 if (!ep->auth_enable) 2703 goto fall_through; 2704 2705 /* Save peer's HMAC list */ 2706 kfree(asoc->peer.peer_hmacs); 2707 asoc->peer.peer_hmacs = kmemdup(param.p, 2708 ntohs(param.p->length), gfp); 2709 if (!asoc->peer.peer_hmacs) { 2710 retval = 0; 2711 break; 2712 } 2713 2714 /* Set the default HMAC the peer requested*/ 2715 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2716 break; 2717 2718 case SCTP_PARAM_CHUNKS: 2719 if (!ep->auth_enable) 2720 goto fall_through; 2721 2722 kfree(asoc->peer.peer_chunks); 2723 asoc->peer.peer_chunks = kmemdup(param.p, 2724 ntohs(param.p->length), gfp); 2725 if (!asoc->peer.peer_chunks) 2726 retval = 0; 2727 break; 2728 fall_through: 2729 default: 2730 /* Any unrecognized parameters should have been caught 2731 * and handled by sctp_verify_param() which should be 2732 * called prior to this routine. Simply log the error 2733 * here. 2734 */ 2735 pr_debug("%s: ignoring param:%d for association:%p.\n", 2736 __func__, ntohs(param.p->type), asoc); 2737 break; 2738 } 2739 2740 return retval; 2741 } 2742 2743 /* Select a new verification tag. */ 2744 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2745 { 2746 /* I believe that this random number generator complies with RFC1750. 2747 * A tag of 0 is reserved for special cases (e.g. INIT). 2748 */ 2749 __u32 x; 2750 2751 do { 2752 get_random_bytes(&x, sizeof(__u32)); 2753 } while (x == 0); 2754 2755 return x; 2756 } 2757 2758 /* Select an initial TSN to send during startup. */ 2759 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2760 { 2761 __u32 retval; 2762 2763 get_random_bytes(&retval, sizeof(__u32)); 2764 return retval; 2765 } 2766 2767 /* 2768 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2769 * 0 1 2 3 2770 * 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 2771 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2772 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2773 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2774 * | Serial Number | 2775 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2776 * | Address Parameter | 2777 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2778 * | ASCONF Parameter #1 | 2779 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2780 * \ \ 2781 * / .... / 2782 * \ \ 2783 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2784 * | ASCONF Parameter #N | 2785 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2786 * 2787 * Address Parameter and other parameter will not be wrapped in this function 2788 */ 2789 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2790 union sctp_addr *addr, 2791 int vparam_len) 2792 { 2793 struct sctp_addiphdr asconf; 2794 struct sctp_chunk *retval; 2795 int length = sizeof(asconf) + vparam_len; 2796 union sctp_addr_param addrparam; 2797 int addrlen; 2798 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2799 2800 addrlen = af->to_addr_param(addr, &addrparam); 2801 if (!addrlen) 2802 return NULL; 2803 length += addrlen; 2804 2805 /* Create the chunk. */ 2806 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length, 2807 GFP_ATOMIC); 2808 if (!retval) 2809 return NULL; 2810 2811 asconf.serial = htonl(asoc->addip_serial++); 2812 2813 retval->subh.addip_hdr = 2814 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2815 retval->param_hdr.v = 2816 sctp_addto_chunk(retval, addrlen, &addrparam); 2817 2818 return retval; 2819 } 2820 2821 /* ADDIP 2822 * 3.2.1 Add IP Address 2823 * 0 1 2 3 2824 * 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 2825 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2826 * | Type = 0xC001 | Length = Variable | 2827 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2828 * | ASCONF-Request Correlation ID | 2829 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2830 * | Address Parameter | 2831 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2832 * 2833 * 3.2.2 Delete IP Address 2834 * 0 1 2 3 2835 * 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 2836 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2837 * | Type = 0xC002 | Length = Variable | 2838 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2839 * | ASCONF-Request Correlation ID | 2840 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2841 * | Address Parameter | 2842 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2843 * 2844 */ 2845 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2846 union sctp_addr *laddr, 2847 struct sockaddr *addrs, 2848 int addrcnt, __be16 flags) 2849 { 2850 union sctp_addr_param addr_param; 2851 struct sctp_addip_param param; 2852 int paramlen = sizeof(param); 2853 struct sctp_chunk *retval; 2854 int addr_param_len = 0; 2855 union sctp_addr *addr; 2856 int totallen = 0, i; 2857 int del_pickup = 0; 2858 struct sctp_af *af; 2859 void *addr_buf; 2860 2861 /* Get total length of all the address parameters. */ 2862 addr_buf = addrs; 2863 for (i = 0; i < addrcnt; i++) { 2864 addr = addr_buf; 2865 af = sctp_get_af_specific(addr->v4.sin_family); 2866 addr_param_len = af->to_addr_param(addr, &addr_param); 2867 2868 totallen += paramlen; 2869 totallen += addr_param_len; 2870 2871 addr_buf += af->sockaddr_len; 2872 if (asoc->asconf_addr_del_pending && !del_pickup) { 2873 /* reuse the parameter length from the same scope one */ 2874 totallen += paramlen; 2875 totallen += addr_param_len; 2876 del_pickup = 1; 2877 2878 pr_debug("%s: picked same-scope del_pending addr, " 2879 "totallen for all addresses is %d\n", 2880 __func__, totallen); 2881 } 2882 } 2883 2884 /* Create an asconf chunk with the required length. */ 2885 retval = sctp_make_asconf(asoc, laddr, totallen); 2886 if (!retval) 2887 return NULL; 2888 2889 /* Add the address parameters to the asconf chunk. */ 2890 addr_buf = addrs; 2891 for (i = 0; i < addrcnt; i++) { 2892 addr = addr_buf; 2893 af = sctp_get_af_specific(addr->v4.sin_family); 2894 addr_param_len = af->to_addr_param(addr, &addr_param); 2895 param.param_hdr.type = flags; 2896 param.param_hdr.length = htons(paramlen + addr_param_len); 2897 param.crr_id = htonl(i); 2898 2899 sctp_addto_chunk(retval, paramlen, ¶m); 2900 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2901 2902 addr_buf += af->sockaddr_len; 2903 } 2904 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2905 addr = asoc->asconf_addr_del_pending; 2906 af = sctp_get_af_specific(addr->v4.sin_family); 2907 addr_param_len = af->to_addr_param(addr, &addr_param); 2908 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2909 param.param_hdr.length = htons(paramlen + addr_param_len); 2910 param.crr_id = htonl(i); 2911 2912 sctp_addto_chunk(retval, paramlen, ¶m); 2913 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2914 } 2915 return retval; 2916 } 2917 2918 /* ADDIP 2919 * 3.2.4 Set Primary IP Address 2920 * 0 1 2 3 2921 * 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 2922 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2923 * | Type =0xC004 | Length = Variable | 2924 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2925 * | ASCONF-Request Correlation ID | 2926 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2927 * | Address Parameter | 2928 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2929 * 2930 * Create an ASCONF chunk with Set Primary IP address parameter. 2931 */ 2932 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2933 union sctp_addr *addr) 2934 { 2935 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2936 union sctp_addr_param addrparam; 2937 struct sctp_addip_param param; 2938 struct sctp_chunk *retval; 2939 int len = sizeof(param); 2940 int addrlen; 2941 2942 addrlen = af->to_addr_param(addr, &addrparam); 2943 if (!addrlen) 2944 return NULL; 2945 len += addrlen; 2946 2947 /* Create the chunk and make asconf header. */ 2948 retval = sctp_make_asconf(asoc, addr, len); 2949 if (!retval) 2950 return NULL; 2951 2952 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2953 param.param_hdr.length = htons(len); 2954 param.crr_id = 0; 2955 2956 sctp_addto_chunk(retval, sizeof(param), ¶m); 2957 sctp_addto_chunk(retval, addrlen, &addrparam); 2958 2959 return retval; 2960 } 2961 2962 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2963 * 0 1 2 3 2964 * 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 2965 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2966 * | Type = 0x80 | Chunk Flags | Chunk Length | 2967 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2968 * | Serial Number | 2969 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2970 * | ASCONF Parameter Response#1 | 2971 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2972 * \ \ 2973 * / .... / 2974 * \ \ 2975 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2976 * | ASCONF Parameter Response#N | 2977 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2978 * 2979 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2980 */ 2981 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2982 __u32 serial, int vparam_len) 2983 { 2984 struct sctp_addiphdr asconf; 2985 struct sctp_chunk *retval; 2986 int length = sizeof(asconf) + vparam_len; 2987 2988 /* Create the chunk. */ 2989 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length, 2990 GFP_ATOMIC); 2991 if (!retval) 2992 return NULL; 2993 2994 asconf.serial = htonl(serial); 2995 2996 retval->subh.addip_hdr = 2997 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2998 2999 return retval; 3000 } 3001 3002 /* Add response parameters to an ASCONF_ACK chunk. */ 3003 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 3004 __be16 err_code, 3005 struct sctp_addip_param *asconf_param) 3006 { 3007 struct sctp_addip_param ack_param; 3008 struct sctp_errhdr err_param; 3009 int asconf_param_len = 0; 3010 int err_param_len = 0; 3011 __be16 response_type; 3012 3013 if (SCTP_ERROR_NO_ERROR == err_code) { 3014 response_type = SCTP_PARAM_SUCCESS_REPORT; 3015 } else { 3016 response_type = SCTP_PARAM_ERR_CAUSE; 3017 err_param_len = sizeof(err_param); 3018 if (asconf_param) 3019 asconf_param_len = 3020 ntohs(asconf_param->param_hdr.length); 3021 } 3022 3023 /* Add Success Indication or Error Cause Indication parameter. */ 3024 ack_param.param_hdr.type = response_type; 3025 ack_param.param_hdr.length = htons(sizeof(ack_param) + 3026 err_param_len + 3027 asconf_param_len); 3028 ack_param.crr_id = crr_id; 3029 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 3030 3031 if (SCTP_ERROR_NO_ERROR == err_code) 3032 return; 3033 3034 /* Add Error Cause parameter. */ 3035 err_param.cause = err_code; 3036 err_param.length = htons(err_param_len + asconf_param_len); 3037 sctp_addto_chunk(chunk, err_param_len, &err_param); 3038 3039 /* Add the failed TLV copied from ASCONF chunk. */ 3040 if (asconf_param) 3041 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 3042 } 3043 3044 /* Process a asconf parameter. */ 3045 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 3046 struct sctp_chunk *asconf, 3047 struct sctp_addip_param *asconf_param) 3048 { 3049 union sctp_addr_param *addr_param; 3050 struct sctp_transport *peer; 3051 union sctp_addr addr; 3052 struct sctp_af *af; 3053 3054 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3055 3056 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 3057 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 3058 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 3059 return SCTP_ERROR_UNKNOWN_PARAM; 3060 3061 switch (addr_param->p.type) { 3062 case SCTP_PARAM_IPV6_ADDRESS: 3063 if (!asoc->peer.ipv6_address) 3064 return SCTP_ERROR_DNS_FAILED; 3065 break; 3066 case SCTP_PARAM_IPV4_ADDRESS: 3067 if (!asoc->peer.ipv4_address) 3068 return SCTP_ERROR_DNS_FAILED; 3069 break; 3070 default: 3071 return SCTP_ERROR_DNS_FAILED; 3072 } 3073 3074 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3075 if (unlikely(!af)) 3076 return SCTP_ERROR_DNS_FAILED; 3077 3078 if (!af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0)) 3079 return SCTP_ERROR_DNS_FAILED; 3080 3081 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3082 * or multicast address. 3083 * (note: wildcard is permitted and requires special handling so 3084 * make sure we check for that) 3085 */ 3086 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3087 return SCTP_ERROR_DNS_FAILED; 3088 3089 switch (asconf_param->param_hdr.type) { 3090 case SCTP_PARAM_ADD_IP: 3091 /* Section 4.2.1: 3092 * If the address 0.0.0.0 or ::0 is provided, the source 3093 * address of the packet MUST be added. 3094 */ 3095 if (af->is_any(&addr)) 3096 memcpy(&addr, &asconf->source, sizeof(addr)); 3097 3098 if (security_sctp_bind_connect(asoc->ep->base.sk, 3099 SCTP_PARAM_ADD_IP, 3100 (struct sockaddr *)&addr, 3101 af->sockaddr_len)) 3102 return SCTP_ERROR_REQ_REFUSED; 3103 3104 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3105 * request and does not have the local resources to add this 3106 * new address to the association, it MUST return an Error 3107 * Cause TLV set to the new error code 'Operation Refused 3108 * Due to Resource Shortage'. 3109 */ 3110 3111 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3112 if (!peer) 3113 return SCTP_ERROR_RSRC_LOW; 3114 3115 /* Start the heartbeat timer. */ 3116 sctp_transport_reset_hb_timer(peer); 3117 asoc->new_transport = peer; 3118 break; 3119 case SCTP_PARAM_DEL_IP: 3120 /* ADDIP 4.3 D7) If a request is received to delete the 3121 * last remaining IP address of a peer endpoint, the receiver 3122 * MUST send an Error Cause TLV with the error cause set to the 3123 * new error code 'Request to Delete Last Remaining IP Address'. 3124 */ 3125 if (asoc->peer.transport_count == 1) 3126 return SCTP_ERROR_DEL_LAST_IP; 3127 3128 /* ADDIP 4.3 D8) If a request is received to delete an IP 3129 * address which is also the source address of the IP packet 3130 * which contained the ASCONF chunk, the receiver MUST reject 3131 * this request. To reject the request the receiver MUST send 3132 * an Error Cause TLV set to the new error code 'Request to 3133 * Delete Source IP Address' 3134 */ 3135 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3136 return SCTP_ERROR_DEL_SRC_IP; 3137 3138 /* Section 4.2.2 3139 * If the address 0.0.0.0 or ::0 is provided, all 3140 * addresses of the peer except the source address of the 3141 * packet MUST be deleted. 3142 */ 3143 if (af->is_any(&addr)) { 3144 sctp_assoc_set_primary(asoc, asconf->transport); 3145 sctp_assoc_del_nonprimary_peers(asoc, 3146 asconf->transport); 3147 return SCTP_ERROR_NO_ERROR; 3148 } 3149 3150 /* If the address is not part of the association, the 3151 * ASCONF-ACK with Error Cause Indication Parameter 3152 * which including cause of Unresolvable Address should 3153 * be sent. 3154 */ 3155 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3156 if (!peer) 3157 return SCTP_ERROR_DNS_FAILED; 3158 3159 sctp_assoc_rm_peer(asoc, peer); 3160 break; 3161 case SCTP_PARAM_SET_PRIMARY: 3162 /* ADDIP Section 4.2.4 3163 * If the address 0.0.0.0 or ::0 is provided, the receiver 3164 * MAY mark the source address of the packet as its 3165 * primary. 3166 */ 3167 if (af->is_any(&addr)) 3168 memcpy(&addr, sctp_source(asconf), sizeof(addr)); 3169 3170 if (security_sctp_bind_connect(asoc->ep->base.sk, 3171 SCTP_PARAM_SET_PRIMARY, 3172 (struct sockaddr *)&addr, 3173 af->sockaddr_len)) 3174 return SCTP_ERROR_REQ_REFUSED; 3175 3176 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3177 if (!peer) 3178 return SCTP_ERROR_DNS_FAILED; 3179 3180 sctp_assoc_set_primary(asoc, peer); 3181 break; 3182 } 3183 3184 return SCTP_ERROR_NO_ERROR; 3185 } 3186 3187 /* Verify the ASCONF packet before we process it. */ 3188 bool sctp_verify_asconf(const struct sctp_association *asoc, 3189 struct sctp_chunk *chunk, bool addr_param_needed, 3190 struct sctp_paramhdr **errp) 3191 { 3192 struct sctp_addip_chunk *addip; 3193 bool addr_param_seen = false; 3194 union sctp_params param; 3195 3196 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr; 3197 sctp_walk_params(param, addip) { 3198 size_t length = ntohs(param.p->length); 3199 3200 *errp = param.p; 3201 switch (param.p->type) { 3202 case SCTP_PARAM_ERR_CAUSE: 3203 break; 3204 case SCTP_PARAM_IPV4_ADDRESS: 3205 if (length != sizeof(struct sctp_ipv4addr_param)) 3206 return false; 3207 /* ensure there is only one addr param and it's in the 3208 * beginning of addip_hdr params, or we reject it. 3209 */ 3210 if (param.v != (addip + 1)) 3211 return false; 3212 addr_param_seen = true; 3213 break; 3214 case SCTP_PARAM_IPV6_ADDRESS: 3215 if (length != sizeof(struct sctp_ipv6addr_param)) 3216 return false; 3217 if (param.v != (addip + 1)) 3218 return false; 3219 addr_param_seen = true; 3220 break; 3221 case SCTP_PARAM_ADD_IP: 3222 case SCTP_PARAM_DEL_IP: 3223 case SCTP_PARAM_SET_PRIMARY: 3224 /* In ASCONF chunks, these need to be first. */ 3225 if (addr_param_needed && !addr_param_seen) 3226 return false; 3227 length = ntohs(param.addip->param_hdr.length); 3228 if (length < sizeof(struct sctp_addip_param) + 3229 sizeof(**errp)) 3230 return false; 3231 break; 3232 case SCTP_PARAM_SUCCESS_REPORT: 3233 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3234 if (length != sizeof(struct sctp_addip_param)) 3235 return false; 3236 break; 3237 default: 3238 /* This is unknown to us, reject! */ 3239 return false; 3240 } 3241 } 3242 3243 /* Remaining sanity checks. */ 3244 if (addr_param_needed && !addr_param_seen) 3245 return false; 3246 if (!addr_param_needed && addr_param_seen) 3247 return false; 3248 if (param.v != chunk->chunk_end) 3249 return false; 3250 3251 return true; 3252 } 3253 3254 /* Process an incoming ASCONF chunk with the next expected serial no. and 3255 * return an ASCONF_ACK chunk to be sent in response. 3256 */ 3257 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3258 struct sctp_chunk *asconf) 3259 { 3260 union sctp_addr_param *addr_param; 3261 struct sctp_addip_chunk *addip; 3262 struct sctp_chunk *asconf_ack; 3263 bool all_param_pass = true; 3264 struct sctp_addiphdr *hdr; 3265 int length = 0, chunk_len; 3266 union sctp_params param; 3267 __be16 err_code; 3268 __u32 serial; 3269 3270 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr; 3271 chunk_len = ntohs(asconf->chunk_hdr->length) - 3272 sizeof(struct sctp_chunkhdr); 3273 hdr = (struct sctp_addiphdr *)asconf->skb->data; 3274 serial = ntohl(hdr->serial); 3275 3276 /* Skip the addiphdr and store a pointer to address parameter. */ 3277 length = sizeof(*hdr); 3278 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3279 chunk_len -= length; 3280 3281 /* Skip the address parameter and store a pointer to the first 3282 * asconf parameter. 3283 */ 3284 length = ntohs(addr_param->p.length); 3285 chunk_len -= length; 3286 3287 /* create an ASCONF_ACK chunk. 3288 * Based on the definitions of parameters, we know that the size of 3289 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3290 * parameters. 3291 */ 3292 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3293 if (!asconf_ack) 3294 goto done; 3295 3296 /* Process the TLVs contained within the ASCONF chunk. */ 3297 sctp_walk_params(param, addip) { 3298 /* Skip preceding address parameters. */ 3299 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 3300 param.p->type == SCTP_PARAM_IPV6_ADDRESS) 3301 continue; 3302 3303 err_code = sctp_process_asconf_param(asoc, asconf, 3304 param.addip); 3305 /* ADDIP 4.1 A7) 3306 * If an error response is received for a TLV parameter, 3307 * all TLVs with no response before the failed TLV are 3308 * considered successful if not reported. All TLVs after 3309 * the failed response are considered unsuccessful unless 3310 * a specific success indication is present for the parameter. 3311 */ 3312 if (err_code != SCTP_ERROR_NO_ERROR) 3313 all_param_pass = false; 3314 if (!all_param_pass) 3315 sctp_add_asconf_response(asconf_ack, param.addip->crr_id, 3316 err_code, param.addip); 3317 3318 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3319 * an IP address sends an 'Out of Resource' in its response, it 3320 * MUST also fail any subsequent add or delete requests bundled 3321 * in the ASCONF. 3322 */ 3323 if (err_code == SCTP_ERROR_RSRC_LOW) 3324 goto done; 3325 } 3326 done: 3327 asoc->peer.addip_serial++; 3328 3329 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3330 * after freeing the reference to old asconf ack if any. 3331 */ 3332 if (asconf_ack) { 3333 sctp_chunk_hold(asconf_ack); 3334 list_add_tail(&asconf_ack->transmitted_list, 3335 &asoc->asconf_ack_list); 3336 } 3337 3338 return asconf_ack; 3339 } 3340 3341 /* Process a asconf parameter that is successfully acked. */ 3342 static void sctp_asconf_param_success(struct sctp_association *asoc, 3343 struct sctp_addip_param *asconf_param) 3344 { 3345 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3346 union sctp_addr_param *addr_param; 3347 struct sctp_sockaddr_entry *saddr; 3348 struct sctp_transport *transport; 3349 union sctp_addr addr; 3350 struct sctp_af *af; 3351 3352 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3353 3354 /* We have checked the packet before, so we do not check again. */ 3355 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3356 if (!af->from_addr_param(&addr, addr_param, htons(bp->port), 0)) 3357 return; 3358 3359 switch (asconf_param->param_hdr.type) { 3360 case SCTP_PARAM_ADD_IP: 3361 /* This is always done in BH context with a socket lock 3362 * held, so the list can not change. 3363 */ 3364 local_bh_disable(); 3365 list_for_each_entry(saddr, &bp->address_list, list) { 3366 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3367 saddr->state = SCTP_ADDR_SRC; 3368 } 3369 local_bh_enable(); 3370 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3371 transports) { 3372 sctp_transport_dst_release(transport); 3373 } 3374 break; 3375 case SCTP_PARAM_DEL_IP: 3376 local_bh_disable(); 3377 sctp_del_bind_addr(bp, &addr); 3378 if (asoc->asconf_addr_del_pending != NULL && 3379 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3380 kfree(asoc->asconf_addr_del_pending); 3381 asoc->asconf_addr_del_pending = NULL; 3382 } 3383 local_bh_enable(); 3384 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3385 transports) { 3386 sctp_transport_dst_release(transport); 3387 } 3388 break; 3389 default: 3390 break; 3391 } 3392 } 3393 3394 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3395 * for the given asconf parameter. If there is no response for this parameter, 3396 * return the error code based on the third argument 'no_err'. 3397 * ADDIP 4.1 3398 * A7) If an error response is received for a TLV parameter, all TLVs with no 3399 * response before the failed TLV are considered successful if not reported. 3400 * All TLVs after the failed response are considered unsuccessful unless a 3401 * specific success indication is present for the parameter. 3402 */ 3403 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3404 struct sctp_addip_param *asconf_param, 3405 int no_err) 3406 { 3407 struct sctp_addip_param *asconf_ack_param; 3408 struct sctp_errhdr *err_param; 3409 int asconf_ack_len; 3410 __be16 err_code; 3411 int length; 3412 3413 if (no_err) 3414 err_code = SCTP_ERROR_NO_ERROR; 3415 else 3416 err_code = SCTP_ERROR_REQ_REFUSED; 3417 3418 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3419 sizeof(struct sctp_chunkhdr); 3420 3421 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3422 * the first asconf_ack parameter. 3423 */ 3424 length = sizeof(struct sctp_addiphdr); 3425 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data + 3426 length); 3427 asconf_ack_len -= length; 3428 3429 while (asconf_ack_len > 0) { 3430 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3431 switch (asconf_ack_param->param_hdr.type) { 3432 case SCTP_PARAM_SUCCESS_REPORT: 3433 return SCTP_ERROR_NO_ERROR; 3434 case SCTP_PARAM_ERR_CAUSE: 3435 length = sizeof(*asconf_ack_param); 3436 err_param = (void *)asconf_ack_param + length; 3437 asconf_ack_len -= length; 3438 if (asconf_ack_len > 0) 3439 return err_param->cause; 3440 else 3441 return SCTP_ERROR_INV_PARAM; 3442 break; 3443 default: 3444 return SCTP_ERROR_INV_PARAM; 3445 } 3446 } 3447 3448 length = ntohs(asconf_ack_param->param_hdr.length); 3449 asconf_ack_param = (void *)asconf_ack_param + length; 3450 asconf_ack_len -= length; 3451 } 3452 3453 return err_code; 3454 } 3455 3456 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3457 int sctp_process_asconf_ack(struct sctp_association *asoc, 3458 struct sctp_chunk *asconf_ack) 3459 { 3460 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3461 struct sctp_addip_param *asconf_param; 3462 __be16 err_code = SCTP_ERROR_NO_ERROR; 3463 union sctp_addr_param *addr_param; 3464 int asconf_len = asconf->skb->len; 3465 int all_param_pass = 0; 3466 int length = 0; 3467 int no_err = 1; 3468 int retval = 0; 3469 3470 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3471 * a pointer to address parameter. 3472 */ 3473 length = sizeof(struct sctp_addip_chunk); 3474 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3475 asconf_len -= length; 3476 3477 /* Skip the address parameter in the last asconf sent and store a 3478 * pointer to the first asconf parameter. 3479 */ 3480 length = ntohs(addr_param->p.length); 3481 asconf_param = (void *)addr_param + length; 3482 asconf_len -= length; 3483 3484 /* ADDIP 4.1 3485 * A8) If there is no response(s) to specific TLV parameter(s), and no 3486 * failures are indicated, then all request(s) are considered 3487 * successful. 3488 */ 3489 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr)) 3490 all_param_pass = 1; 3491 3492 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3493 while (asconf_len > 0) { 3494 if (all_param_pass) 3495 err_code = SCTP_ERROR_NO_ERROR; 3496 else { 3497 err_code = sctp_get_asconf_response(asconf_ack, 3498 asconf_param, 3499 no_err); 3500 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3501 no_err = 0; 3502 } 3503 3504 switch (err_code) { 3505 case SCTP_ERROR_NO_ERROR: 3506 sctp_asconf_param_success(asoc, asconf_param); 3507 break; 3508 3509 case SCTP_ERROR_RSRC_LOW: 3510 retval = 1; 3511 break; 3512 3513 case SCTP_ERROR_UNKNOWN_PARAM: 3514 /* Disable sending this type of asconf parameter in 3515 * future. 3516 */ 3517 asoc->peer.addip_disabled_mask |= 3518 asconf_param->param_hdr.type; 3519 break; 3520 3521 case SCTP_ERROR_REQ_REFUSED: 3522 case SCTP_ERROR_DEL_LAST_IP: 3523 case SCTP_ERROR_DEL_SRC_IP: 3524 default: 3525 break; 3526 } 3527 3528 /* Skip the processed asconf parameter and move to the next 3529 * one. 3530 */ 3531 length = ntohs(asconf_param->param_hdr.length); 3532 asconf_param = (void *)asconf_param + length; 3533 asconf_len -= length; 3534 } 3535 3536 if (no_err && asoc->src_out_of_asoc_ok) { 3537 asoc->src_out_of_asoc_ok = 0; 3538 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3539 } 3540 3541 /* Free the cached last sent asconf chunk. */ 3542 list_del_init(&asconf->transmitted_list); 3543 sctp_chunk_free(asconf); 3544 asoc->addip_last_asconf = NULL; 3545 3546 return retval; 3547 } 3548 3549 /* Make a FWD TSN chunk. */ 3550 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3551 __u32 new_cum_tsn, size_t nstreams, 3552 struct sctp_fwdtsn_skip *skiplist) 3553 { 3554 struct sctp_chunk *retval = NULL; 3555 struct sctp_fwdtsn_hdr ftsn_hdr; 3556 struct sctp_fwdtsn_skip skip; 3557 size_t hint; 3558 int i; 3559 3560 hint = (nstreams + 1) * sizeof(__u32); 3561 3562 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC); 3563 3564 if (!retval) 3565 return NULL; 3566 3567 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3568 retval->subh.fwdtsn_hdr = 3569 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3570 3571 for (i = 0; i < nstreams; i++) { 3572 skip.stream = skiplist[i].stream; 3573 skip.ssn = skiplist[i].ssn; 3574 sctp_addto_chunk(retval, sizeof(skip), &skip); 3575 } 3576 3577 return retval; 3578 } 3579 3580 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc, 3581 __u32 new_cum_tsn, size_t nstreams, 3582 struct sctp_ifwdtsn_skip *skiplist) 3583 { 3584 struct sctp_chunk *retval = NULL; 3585 struct sctp_ifwdtsn_hdr ftsn_hdr; 3586 size_t hint; 3587 3588 hint = (nstreams + 1) * sizeof(__u32); 3589 3590 retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint, 3591 GFP_ATOMIC); 3592 if (!retval) 3593 return NULL; 3594 3595 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3596 retval->subh.ifwdtsn_hdr = 3597 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3598 3599 sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist); 3600 3601 return retval; 3602 } 3603 3604 /* RE-CONFIG 3.1 (RE-CONFIG chunk) 3605 * 0 1 2 3 3606 * 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 3607 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3608 * | Type = 130 | Chunk Flags | Chunk Length | 3609 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3610 * \ \ 3611 * / Re-configuration Parameter / 3612 * \ \ 3613 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3614 * \ \ 3615 * / Re-configuration Parameter (optional) / 3616 * \ \ 3617 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3618 */ 3619 static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc, 3620 int length) 3621 { 3622 struct sctp_reconf_chunk *reconf; 3623 struct sctp_chunk *retval; 3624 3625 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length, 3626 GFP_ATOMIC); 3627 if (!retval) 3628 return NULL; 3629 3630 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr; 3631 retval->param_hdr.v = (u8 *)(reconf + 1); 3632 3633 return retval; 3634 } 3635 3636 /* RE-CONFIG 4.1 (STREAM OUT RESET) 3637 * 0 1 2 3 3638 * 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 3639 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3640 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N | 3641 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3642 * | Re-configuration Request Sequence Number | 3643 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3644 * | Re-configuration Response Sequence Number | 3645 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3646 * | Sender's Last Assigned TSN | 3647 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3648 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3649 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3650 * / ...... / 3651 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3652 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3653 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3654 * 3655 * RE-CONFIG 4.2 (STREAM IN RESET) 3656 * 0 1 2 3 3657 * 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 3658 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3659 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N | 3660 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3661 * | Re-configuration Request Sequence Number | 3662 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3663 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3664 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3665 * / ...... / 3666 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3667 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3668 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3669 */ 3670 struct sctp_chunk *sctp_make_strreset_req( 3671 const struct sctp_association *asoc, 3672 __u16 stream_num, __be16 *stream_list, 3673 bool out, bool in) 3674 { 3675 __u16 stream_len = stream_num * sizeof(__u16); 3676 struct sctp_strreset_outreq outreq; 3677 struct sctp_strreset_inreq inreq; 3678 struct sctp_chunk *retval; 3679 __u16 outlen, inlen; 3680 3681 outlen = (sizeof(outreq) + stream_len) * out; 3682 inlen = (sizeof(inreq) + stream_len) * in; 3683 3684 retval = sctp_make_reconf(asoc, SCTP_PAD4(outlen) + SCTP_PAD4(inlen)); 3685 if (!retval) 3686 return NULL; 3687 3688 if (outlen) { 3689 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST; 3690 outreq.param_hdr.length = htons(outlen); 3691 outreq.request_seq = htonl(asoc->strreset_outseq); 3692 outreq.response_seq = htonl(asoc->strreset_inseq - 1); 3693 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1); 3694 3695 sctp_addto_chunk(retval, sizeof(outreq), &outreq); 3696 3697 if (stream_len) 3698 sctp_addto_chunk(retval, stream_len, stream_list); 3699 } 3700 3701 if (inlen) { 3702 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST; 3703 inreq.param_hdr.length = htons(inlen); 3704 inreq.request_seq = htonl(asoc->strreset_outseq + out); 3705 3706 sctp_addto_chunk(retval, sizeof(inreq), &inreq); 3707 3708 if (stream_len) 3709 sctp_addto_chunk(retval, stream_len, stream_list); 3710 } 3711 3712 return retval; 3713 } 3714 3715 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL) 3716 * 0 1 2 3 3717 * 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 3718 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3719 * | Parameter Type = 15 | Parameter Length = 8 | 3720 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3721 * | Re-configuration Request Sequence Number | 3722 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3723 */ 3724 struct sctp_chunk *sctp_make_strreset_tsnreq( 3725 const struct sctp_association *asoc) 3726 { 3727 struct sctp_strreset_tsnreq tsnreq; 3728 __u16 length = sizeof(tsnreq); 3729 struct sctp_chunk *retval; 3730 3731 retval = sctp_make_reconf(asoc, length); 3732 if (!retval) 3733 return NULL; 3734 3735 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST; 3736 tsnreq.param_hdr.length = htons(length); 3737 tsnreq.request_seq = htonl(asoc->strreset_outseq); 3738 3739 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq); 3740 3741 return retval; 3742 } 3743 3744 /* RE-CONFIG 4.5/4.6 (ADD STREAM) 3745 * 0 1 2 3 3746 * 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 3747 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3748 * | Parameter Type = 17 | Parameter Length = 12 | 3749 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3750 * | Re-configuration Request Sequence Number | 3751 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3752 * | Number of new streams | Reserved | 3753 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3754 */ 3755 struct sctp_chunk *sctp_make_strreset_addstrm( 3756 const struct sctp_association *asoc, 3757 __u16 out, __u16 in) 3758 { 3759 struct sctp_strreset_addstrm addstrm; 3760 __u16 size = sizeof(addstrm); 3761 struct sctp_chunk *retval; 3762 3763 retval = sctp_make_reconf(asoc, (!!out + !!in) * size); 3764 if (!retval) 3765 return NULL; 3766 3767 if (out) { 3768 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS; 3769 addstrm.param_hdr.length = htons(size); 3770 addstrm.number_of_streams = htons(out); 3771 addstrm.request_seq = htonl(asoc->strreset_outseq); 3772 addstrm.reserved = 0; 3773 3774 sctp_addto_chunk(retval, size, &addstrm); 3775 } 3776 3777 if (in) { 3778 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS; 3779 addstrm.param_hdr.length = htons(size); 3780 addstrm.number_of_streams = htons(in); 3781 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out); 3782 addstrm.reserved = 0; 3783 3784 sctp_addto_chunk(retval, size, &addstrm); 3785 } 3786 3787 return retval; 3788 } 3789 3790 /* RE-CONFIG 4.4 (RESP) 3791 * 0 1 2 3 3792 * 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 3793 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3794 * | Parameter Type = 16 | Parameter Length | 3795 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3796 * | Re-configuration Response Sequence Number | 3797 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3798 * | Result | 3799 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3800 */ 3801 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc, 3802 __u32 result, __u32 sn) 3803 { 3804 struct sctp_strreset_resp resp; 3805 __u16 length = sizeof(resp); 3806 struct sctp_chunk *retval; 3807 3808 retval = sctp_make_reconf(asoc, length); 3809 if (!retval) 3810 return NULL; 3811 3812 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3813 resp.param_hdr.length = htons(length); 3814 resp.response_seq = htonl(sn); 3815 resp.result = htonl(result); 3816 3817 sctp_addto_chunk(retval, sizeof(resp), &resp); 3818 3819 return retval; 3820 } 3821 3822 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP) 3823 * 0 1 2 3 3824 * 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 3825 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3826 * | Parameter Type = 16 | Parameter Length | 3827 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3828 * | Re-configuration Response Sequence Number | 3829 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3830 * | Result | 3831 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3832 * | Sender's Next TSN (optional) | 3833 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3834 * | Receiver's Next TSN (optional) | 3835 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3836 */ 3837 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc, 3838 __u32 result, __u32 sn, 3839 __u32 sender_tsn, 3840 __u32 receiver_tsn) 3841 { 3842 struct sctp_strreset_resptsn tsnresp; 3843 __u16 length = sizeof(tsnresp); 3844 struct sctp_chunk *retval; 3845 3846 retval = sctp_make_reconf(asoc, length); 3847 if (!retval) 3848 return NULL; 3849 3850 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3851 tsnresp.param_hdr.length = htons(length); 3852 3853 tsnresp.response_seq = htonl(sn); 3854 tsnresp.result = htonl(result); 3855 tsnresp.senders_next_tsn = htonl(sender_tsn); 3856 tsnresp.receivers_next_tsn = htonl(receiver_tsn); 3857 3858 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp); 3859 3860 return retval; 3861 } 3862 3863 bool sctp_verify_reconf(const struct sctp_association *asoc, 3864 struct sctp_chunk *chunk, 3865 struct sctp_paramhdr **errp) 3866 { 3867 struct sctp_reconf_chunk *hdr; 3868 union sctp_params param; 3869 __be16 last = 0; 3870 __u16 cnt = 0; 3871 3872 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; 3873 sctp_walk_params(param, hdr) { 3874 __u16 length = ntohs(param.p->length); 3875 3876 *errp = param.p; 3877 if (cnt++ > 2) 3878 return false; 3879 switch (param.p->type) { 3880 case SCTP_PARAM_RESET_OUT_REQUEST: 3881 if (length < sizeof(struct sctp_strreset_outreq) || 3882 (last && last != SCTP_PARAM_RESET_RESPONSE && 3883 last != SCTP_PARAM_RESET_IN_REQUEST)) 3884 return false; 3885 break; 3886 case SCTP_PARAM_RESET_IN_REQUEST: 3887 if (length < sizeof(struct sctp_strreset_inreq) || 3888 (last && last != SCTP_PARAM_RESET_OUT_REQUEST)) 3889 return false; 3890 break; 3891 case SCTP_PARAM_RESET_RESPONSE: 3892 if ((length != sizeof(struct sctp_strreset_resp) && 3893 length != sizeof(struct sctp_strreset_resptsn)) || 3894 (last && last != SCTP_PARAM_RESET_RESPONSE && 3895 last != SCTP_PARAM_RESET_OUT_REQUEST)) 3896 return false; 3897 break; 3898 case SCTP_PARAM_RESET_TSN_REQUEST: 3899 if (length != 3900 sizeof(struct sctp_strreset_tsnreq) || last) 3901 return false; 3902 break; 3903 case SCTP_PARAM_RESET_ADD_IN_STREAMS: 3904 if (length != sizeof(struct sctp_strreset_addstrm) || 3905 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS)) 3906 return false; 3907 break; 3908 case SCTP_PARAM_RESET_ADD_OUT_STREAMS: 3909 if (length != sizeof(struct sctp_strreset_addstrm) || 3910 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS)) 3911 return false; 3912 break; 3913 default: 3914 return false; 3915 } 3916 3917 last = param.p->type; 3918 } 3919 3920 return true; 3921 } 3922