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