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 /* Create an Operation Error chunk with the specified space reserved. 1222 * This routine can be used for containing multiple causes in the chunk. 1223 */ 1224 static struct sctp_chunk *sctp_make_op_error_space( 1225 const struct sctp_association *asoc, 1226 const struct sctp_chunk *chunk, 1227 size_t size) 1228 { 1229 struct sctp_chunk *retval; 1230 1231 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0, 1232 sizeof(struct sctp_errhdr) + size, 1233 GFP_ATOMIC); 1234 if (!retval) 1235 goto nodata; 1236 1237 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1238 * 1239 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1240 * HEARTBEAT ACK, etc.) to the same destination transport 1241 * address from which it received the DATA or control chunk 1242 * to which it is replying. 1243 * 1244 */ 1245 if (chunk) 1246 retval->transport = chunk->transport; 1247 1248 nodata: 1249 return retval; 1250 } 1251 1252 /* Create an Operation Error chunk of a fixed size, specifically, 1253 * min(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) - overheads. 1254 * This is a helper function to allocate an error chunk for those 1255 * invalid parameter codes in which we may not want to report all the 1256 * errors, if the incoming chunk is large. If it can't fit in a single 1257 * packet, we ignore it. 1258 */ 1259 static inline struct sctp_chunk *sctp_make_op_error_limited( 1260 const struct sctp_association *asoc, 1261 const struct sctp_chunk *chunk) 1262 { 1263 size_t size = SCTP_DEFAULT_MAXSEGMENT; 1264 struct sctp_sock *sp = NULL; 1265 1266 if (asoc) { 1267 size = min_t(size_t, size, asoc->pathmtu); 1268 sp = sctp_sk(asoc->base.sk); 1269 } 1270 1271 size = sctp_mtu_payload(sp, size, sizeof(struct sctp_errhdr)); 1272 1273 return sctp_make_op_error_space(asoc, chunk, size); 1274 } 1275 1276 /* Create an Operation Error chunk. */ 1277 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1278 const struct sctp_chunk *chunk, 1279 __be16 cause_code, const void *payload, 1280 size_t paylen, size_t reserve_tail) 1281 { 1282 struct sctp_chunk *retval; 1283 1284 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); 1285 if (!retval) 1286 goto nodata; 1287 1288 sctp_init_cause(retval, cause_code, paylen + reserve_tail); 1289 sctp_addto_chunk(retval, paylen, payload); 1290 if (reserve_tail) 1291 sctp_addto_param(retval, reserve_tail, NULL); 1292 1293 nodata: 1294 return retval; 1295 } 1296 1297 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc, 1298 __u16 key_id) 1299 { 1300 struct sctp_authhdr auth_hdr; 1301 struct sctp_hmac *hmac_desc; 1302 struct sctp_chunk *retval; 1303 1304 /* Get the first hmac that the peer told us to use */ 1305 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1306 if (unlikely(!hmac_desc)) 1307 return NULL; 1308 1309 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0, 1310 hmac_desc->hmac_len + sizeof(auth_hdr), 1311 GFP_ATOMIC); 1312 if (!retval) 1313 return NULL; 1314 1315 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1316 auth_hdr.shkey_id = htons(key_id); 1317 1318 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr), 1319 &auth_hdr); 1320 1321 skb_put_zero(retval->skb, hmac_desc->hmac_len); 1322 1323 /* Adjust the chunk header to include the empty MAC */ 1324 retval->chunk_hdr->length = 1325 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1326 retval->chunk_end = skb_tail_pointer(retval->skb); 1327 1328 return retval; 1329 } 1330 1331 1332 /******************************************************************** 1333 * 2nd Level Abstractions 1334 ********************************************************************/ 1335 1336 /* Turn an skb into a chunk. 1337 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1338 * 1339 * sctpimpguide-05.txt Section 2.8.2 1340 * M1) Each time a new DATA chunk is transmitted 1341 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1342 * 'TSN.Missing.Report' count will be used to determine missing chunks 1343 * and when to fast retransmit. 1344 * 1345 */ 1346 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1347 const struct sctp_association *asoc, 1348 struct sock *sk, gfp_t gfp) 1349 { 1350 struct sctp_chunk *retval; 1351 1352 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp); 1353 1354 if (!retval) 1355 goto nodata; 1356 if (!sk) 1357 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb); 1358 1359 INIT_LIST_HEAD(&retval->list); 1360 retval->skb = skb; 1361 retval->asoc = (struct sctp_association *)asoc; 1362 retval->singleton = 1; 1363 1364 retval->fast_retransmit = SCTP_CAN_FRTX; 1365 1366 /* Polish the bead hole. */ 1367 INIT_LIST_HEAD(&retval->transmitted_list); 1368 INIT_LIST_HEAD(&retval->frag_list); 1369 SCTP_DBG_OBJCNT_INC(chunk); 1370 refcount_set(&retval->refcnt, 1); 1371 1372 nodata: 1373 return retval; 1374 } 1375 1376 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1377 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1378 union sctp_addr *dest) 1379 { 1380 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1381 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1382 } 1383 1384 /* Extract the source address from a chunk. */ 1385 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1386 { 1387 /* If we have a known transport, use that. */ 1388 if (chunk->transport) { 1389 return &chunk->transport->ipaddr; 1390 } else { 1391 /* Otherwise, extract it from the IP header. */ 1392 return &chunk->source; 1393 } 1394 } 1395 1396 /* Create a new chunk, setting the type and flags headers from the 1397 * arguments, reserving enough space for a 'paylen' byte payload. 1398 */ 1399 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 1400 __u8 type, __u8 flags, int paylen, 1401 gfp_t gfp) 1402 { 1403 struct sctp_chunkhdr *chunk_hdr; 1404 struct sctp_chunk *retval; 1405 struct sk_buff *skb; 1406 struct sock *sk; 1407 int chunklen; 1408 1409 chunklen = SCTP_PAD4(sizeof(*chunk_hdr) + paylen); 1410 if (chunklen > SCTP_MAX_CHUNK_LEN) 1411 goto nodata; 1412 1413 /* No need to allocate LL here, as this is only a chunk. */ 1414 skb = alloc_skb(chunklen, gfp); 1415 if (!skb) 1416 goto nodata; 1417 1418 /* Make room for the chunk header. */ 1419 chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr)); 1420 chunk_hdr->type = type; 1421 chunk_hdr->flags = flags; 1422 chunk_hdr->length = htons(sizeof(*chunk_hdr)); 1423 1424 sk = asoc ? asoc->base.sk : NULL; 1425 retval = sctp_chunkify(skb, asoc, sk, gfp); 1426 if (!retval) { 1427 kfree_skb(skb); 1428 goto nodata; 1429 } 1430 1431 retval->chunk_hdr = chunk_hdr; 1432 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr); 1433 1434 /* Determine if the chunk needs to be authenticated */ 1435 if (sctp_auth_send_cid(type, asoc)) 1436 retval->auth = 1; 1437 1438 return retval; 1439 nodata: 1440 return NULL; 1441 } 1442 1443 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 1444 __u8 flags, int paylen, gfp_t gfp) 1445 { 1446 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp); 1447 } 1448 1449 struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc, 1450 __u8 flags, int paylen, gfp_t gfp) 1451 { 1452 return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp); 1453 } 1454 1455 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 1456 __u8 type, __u8 flags, int paylen, 1457 gfp_t gfp) 1458 { 1459 struct sctp_chunk *chunk; 1460 1461 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp); 1462 if (chunk) 1463 sctp_control_set_owner_w(chunk); 1464 1465 return chunk; 1466 } 1467 1468 /* Release the memory occupied by a chunk. */ 1469 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1470 { 1471 BUG_ON(!list_empty(&chunk->list)); 1472 list_del_init(&chunk->transmitted_list); 1473 1474 consume_skb(chunk->skb); 1475 consume_skb(chunk->auth_chunk); 1476 1477 SCTP_DBG_OBJCNT_DEC(chunk); 1478 kmem_cache_free(sctp_chunk_cachep, chunk); 1479 } 1480 1481 /* Possibly, free the chunk. */ 1482 void sctp_chunk_free(struct sctp_chunk *chunk) 1483 { 1484 /* Release our reference on the message tracker. */ 1485 if (chunk->msg) 1486 sctp_datamsg_put(chunk->msg); 1487 1488 sctp_chunk_put(chunk); 1489 } 1490 1491 /* Grab a reference to the chunk. */ 1492 void sctp_chunk_hold(struct sctp_chunk *ch) 1493 { 1494 refcount_inc(&ch->refcnt); 1495 } 1496 1497 /* Release a reference to the chunk. */ 1498 void sctp_chunk_put(struct sctp_chunk *ch) 1499 { 1500 if (refcount_dec_and_test(&ch->refcnt)) 1501 sctp_chunk_destroy(ch); 1502 } 1503 1504 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1505 * enough. 1506 */ 1507 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1508 { 1509 int chunklen = ntohs(chunk->chunk_hdr->length); 1510 int padlen = SCTP_PAD4(chunklen) - chunklen; 1511 void *target; 1512 1513 skb_put_zero(chunk->skb, padlen); 1514 target = skb_put_data(chunk->skb, data, len); 1515 1516 /* Adjust the chunk length field. */ 1517 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1518 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1519 1520 return target; 1521 } 1522 1523 /* Append bytes from user space to the end of a chunk. Will panic if 1524 * chunk is not big enough. 1525 * Returns a kernel err value. 1526 */ 1527 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len, 1528 struct iov_iter *from) 1529 { 1530 void *target; 1531 1532 /* Make room in chunk for data. */ 1533 target = skb_put(chunk->skb, len); 1534 1535 /* Copy data (whole iovec) into chunk */ 1536 if (!copy_from_iter_full(target, len, from)) 1537 return -EFAULT; 1538 1539 /* Adjust the chunk length field. */ 1540 chunk->chunk_hdr->length = 1541 htons(ntohs(chunk->chunk_hdr->length) + len); 1542 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1543 1544 return 0; 1545 } 1546 1547 /* Helper function to assign a TSN if needed. This assumes that both 1548 * the data_hdr and association have already been assigned. 1549 */ 1550 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1551 { 1552 struct sctp_stream *stream; 1553 struct sctp_chunk *lchunk; 1554 struct sctp_datamsg *msg; 1555 __u16 ssn, sid; 1556 1557 if (chunk->has_ssn) 1558 return; 1559 1560 /* All fragments will be on the same stream */ 1561 sid = ntohs(chunk->subh.data_hdr->stream); 1562 stream = &chunk->asoc->stream; 1563 1564 /* Now assign the sequence number to the entire message. 1565 * All fragments must have the same stream sequence number. 1566 */ 1567 msg = chunk->msg; 1568 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1569 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1570 ssn = 0; 1571 } else { 1572 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1573 ssn = sctp_ssn_next(stream, out, sid); 1574 else 1575 ssn = sctp_ssn_peek(stream, out, sid); 1576 } 1577 1578 lchunk->subh.data_hdr->ssn = htons(ssn); 1579 lchunk->has_ssn = 1; 1580 } 1581 } 1582 1583 /* Helper function to assign a TSN if needed. This assumes that both 1584 * the data_hdr and association have already been assigned. 1585 */ 1586 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1587 { 1588 if (!chunk->has_tsn) { 1589 /* This is the last possible instant to 1590 * assign a TSN. 1591 */ 1592 chunk->subh.data_hdr->tsn = 1593 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1594 chunk->has_tsn = 1; 1595 } 1596 } 1597 1598 /* Create a CLOSED association to use with an incoming packet. */ 1599 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1600 struct sctp_chunk *chunk, 1601 gfp_t gfp) 1602 { 1603 struct sctp_association *asoc; 1604 enum sctp_scope scope; 1605 struct sk_buff *skb; 1606 1607 /* Create the bare association. */ 1608 scope = sctp_scope(sctp_source(chunk)); 1609 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1610 if (!asoc) 1611 goto nodata; 1612 asoc->temp = 1; 1613 skb = chunk->skb; 1614 /* Create an entry for the source address of the packet. */ 1615 SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1); 1616 1617 nodata: 1618 return asoc; 1619 } 1620 1621 /* Build a cookie representing asoc. 1622 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1623 */ 1624 static struct sctp_cookie_param *sctp_pack_cookie( 1625 const struct sctp_endpoint *ep, 1626 const struct sctp_association *asoc, 1627 const struct sctp_chunk *init_chunk, 1628 int *cookie_len, const __u8 *raw_addrs, 1629 int addrs_len) 1630 { 1631 struct sctp_signed_cookie *cookie; 1632 struct sctp_cookie_param *retval; 1633 int headersize, bodysize; 1634 1635 /* Header size is static data prior to the actual cookie, including 1636 * any padding. 1637 */ 1638 headersize = sizeof(struct sctp_paramhdr) + 1639 (sizeof(struct sctp_signed_cookie) - 1640 sizeof(struct sctp_cookie)); 1641 bodysize = sizeof(struct sctp_cookie) 1642 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1643 1644 /* Pad out the cookie to a multiple to make the signature 1645 * functions simpler to write. 1646 */ 1647 if (bodysize % SCTP_COOKIE_MULTIPLE) 1648 bodysize += SCTP_COOKIE_MULTIPLE 1649 - (bodysize % SCTP_COOKIE_MULTIPLE); 1650 *cookie_len = headersize + bodysize; 1651 1652 /* Clear this memory since we are sending this data structure 1653 * out on the network. 1654 */ 1655 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1656 if (!retval) 1657 goto nodata; 1658 1659 cookie = (struct sctp_signed_cookie *) retval->body; 1660 1661 /* Set up the parameter header. */ 1662 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1663 retval->p.length = htons(*cookie_len); 1664 1665 /* Copy the cookie part of the association itself. */ 1666 cookie->c = asoc->c; 1667 /* Save the raw address list length in the cookie. */ 1668 cookie->c.raw_addr_list_len = addrs_len; 1669 1670 /* Remember PR-SCTP capability. */ 1671 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1672 1673 /* Save adaptation indication in the cookie. */ 1674 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1675 1676 /* Set an expiration time for the cookie. */ 1677 cookie->c.expiration = ktime_add(asoc->cookie_life, 1678 ktime_get_real()); 1679 1680 /* Copy the peer's init packet. */ 1681 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr, 1682 ntohs(init_chunk->chunk_hdr->length)); 1683 1684 /* Copy the raw local address list of the association. */ 1685 memcpy((__u8 *)&cookie->c.peer_init[0] + 1686 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1687 1688 if (sctp_sk(ep->base.sk)->hmac) { 1689 struct crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac; 1690 int err; 1691 1692 /* Sign the message. */ 1693 err = crypto_shash_setkey(tfm, ep->secret_key, 1694 sizeof(ep->secret_key)) ?: 1695 crypto_shash_tfm_digest(tfm, (u8 *)&cookie->c, bodysize, 1696 cookie->signature); 1697 if (err) 1698 goto free_cookie; 1699 } 1700 1701 return retval; 1702 1703 free_cookie: 1704 kfree(retval); 1705 nodata: 1706 *cookie_len = 0; 1707 return NULL; 1708 } 1709 1710 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1711 struct sctp_association *sctp_unpack_cookie( 1712 const struct sctp_endpoint *ep, 1713 const struct sctp_association *asoc, 1714 struct sctp_chunk *chunk, gfp_t gfp, 1715 int *error, struct sctp_chunk **errp) 1716 { 1717 struct sctp_association *retval = NULL; 1718 int headersize, bodysize, fixed_size; 1719 struct sctp_signed_cookie *cookie; 1720 struct sk_buff *skb = chunk->skb; 1721 struct sctp_cookie *bear_cookie; 1722 __u8 *digest = ep->digest; 1723 enum sctp_scope scope; 1724 unsigned int len; 1725 ktime_t kt; 1726 1727 /* Header size is static data prior to the actual cookie, including 1728 * any padding. 1729 */ 1730 headersize = sizeof(struct sctp_chunkhdr) + 1731 (sizeof(struct sctp_signed_cookie) - 1732 sizeof(struct sctp_cookie)); 1733 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1734 fixed_size = headersize + sizeof(struct sctp_cookie); 1735 1736 /* Verify that the chunk looks like it even has a cookie. 1737 * There must be enough room for our cookie and our peer's 1738 * INIT chunk. 1739 */ 1740 len = ntohs(chunk->chunk_hdr->length); 1741 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1742 goto malformed; 1743 1744 /* Verify that the cookie has been padded out. */ 1745 if (bodysize % SCTP_COOKIE_MULTIPLE) 1746 goto malformed; 1747 1748 /* Process the cookie. */ 1749 cookie = chunk->subh.cookie_hdr; 1750 bear_cookie = &cookie->c; 1751 1752 if (!sctp_sk(ep->base.sk)->hmac) 1753 goto no_hmac; 1754 1755 /* Check the signature. */ 1756 { 1757 struct crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac; 1758 int err; 1759 1760 err = crypto_shash_setkey(tfm, ep->secret_key, 1761 sizeof(ep->secret_key)) ?: 1762 crypto_shash_tfm_digest(tfm, (u8 *)bear_cookie, bodysize, 1763 digest); 1764 if (err) { 1765 *error = -SCTP_IERROR_NOMEM; 1766 goto fail; 1767 } 1768 } 1769 1770 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1771 *error = -SCTP_IERROR_BAD_SIG; 1772 goto fail; 1773 } 1774 1775 no_hmac: 1776 /* IG Section 2.35.2: 1777 * 3) Compare the port numbers and the verification tag contained 1778 * within the COOKIE ECHO chunk to the actual port numbers and the 1779 * verification tag within the SCTP common header of the received 1780 * packet. If these values do not match the packet MUST be silently 1781 * discarded, 1782 */ 1783 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1784 *error = -SCTP_IERROR_BAD_TAG; 1785 goto fail; 1786 } 1787 1788 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1789 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1790 *error = -SCTP_IERROR_BAD_PORTS; 1791 goto fail; 1792 } 1793 1794 /* Check to see if the cookie is stale. If there is already 1795 * an association, there is no need to check cookie's expiration 1796 * for init collision case of lost COOKIE ACK. 1797 * If skb has been timestamped, then use the stamp, otherwise 1798 * use current time. This introduces a small possibility that 1799 * a cookie may be considered expired, but this would only slow 1800 * down the new association establishment instead of every packet. 1801 */ 1802 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1803 kt = skb_get_ktime(skb); 1804 else 1805 kt = ktime_get_real(); 1806 1807 if (!asoc && ktime_before(bear_cookie->expiration, kt)) { 1808 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); 1809 __be32 n = htonl(usecs); 1810 1811 /* 1812 * Section 3.3.10.3 Stale Cookie Error (3) 1813 * 1814 * Cause of error 1815 * --------------- 1816 * Stale Cookie Error: Indicates the receipt of a valid State 1817 * Cookie that has expired. 1818 */ 1819 *errp = sctp_make_op_error(asoc, chunk, 1820 SCTP_ERROR_STALE_COOKIE, &n, 1821 sizeof(n), 0); 1822 if (*errp) 1823 *error = -SCTP_IERROR_STALE_COOKIE; 1824 else 1825 *error = -SCTP_IERROR_NOMEM; 1826 1827 goto fail; 1828 } 1829 1830 /* Make a new base association. */ 1831 scope = sctp_scope(sctp_source(chunk)); 1832 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1833 if (!retval) { 1834 *error = -SCTP_IERROR_NOMEM; 1835 goto fail; 1836 } 1837 1838 /* Set up our peer's port number. */ 1839 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1840 1841 /* Populate the association from the cookie. */ 1842 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1843 1844 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1845 GFP_ATOMIC) < 0) { 1846 *error = -SCTP_IERROR_NOMEM; 1847 goto fail; 1848 } 1849 1850 /* Also, add the destination address. */ 1851 if (list_empty(&retval->base.bind_addr.address_list)) { 1852 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1853 sizeof(chunk->dest), SCTP_ADDR_SRC, 1854 GFP_ATOMIC); 1855 } 1856 1857 retval->next_tsn = retval->c.initial_tsn; 1858 retval->ctsn_ack_point = retval->next_tsn - 1; 1859 retval->addip_serial = retval->c.initial_tsn; 1860 retval->strreset_outseq = retval->c.initial_tsn; 1861 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1862 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1863 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1864 1865 /* The INIT stuff will be done by the side effects. */ 1866 return retval; 1867 1868 fail: 1869 if (retval) 1870 sctp_association_free(retval); 1871 1872 return NULL; 1873 1874 malformed: 1875 /* Yikes! The packet is either corrupt or deliberately 1876 * malformed. 1877 */ 1878 *error = -SCTP_IERROR_MALFORMED; 1879 goto fail; 1880 } 1881 1882 /******************************************************************** 1883 * 3rd Level Abstractions 1884 ********************************************************************/ 1885 1886 struct __sctp_missing { 1887 __be32 num_missing; 1888 __be16 type; 1889 } __packed; 1890 1891 /* 1892 * Report a missing mandatory parameter. 1893 */ 1894 static int sctp_process_missing_param(const struct sctp_association *asoc, 1895 enum sctp_param paramtype, 1896 struct sctp_chunk *chunk, 1897 struct sctp_chunk **errp) 1898 { 1899 struct __sctp_missing report; 1900 __u16 len; 1901 1902 len = SCTP_PAD4(sizeof(report)); 1903 1904 /* Make an ERROR chunk, preparing enough room for 1905 * returning multiple unknown parameters. 1906 */ 1907 if (!*errp) 1908 *errp = sctp_make_op_error_space(asoc, chunk, len); 1909 1910 if (*errp) { 1911 report.num_missing = htonl(1); 1912 report.type = paramtype; 1913 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1914 sizeof(report)); 1915 sctp_addto_chunk(*errp, sizeof(report), &report); 1916 } 1917 1918 /* Stop processing this chunk. */ 1919 return 0; 1920 } 1921 1922 /* Report an Invalid Mandatory Parameter. */ 1923 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1924 struct sctp_chunk *chunk, 1925 struct sctp_chunk **errp) 1926 { 1927 /* Invalid Mandatory Parameter Error has no payload. */ 1928 1929 if (!*errp) 1930 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1931 1932 if (*errp) 1933 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1934 1935 /* Stop processing this chunk. */ 1936 return 0; 1937 } 1938 1939 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1940 struct sctp_paramhdr *param, 1941 const struct sctp_chunk *chunk, 1942 struct sctp_chunk **errp) 1943 { 1944 /* This is a fatal error. Any accumulated non-fatal errors are 1945 * not reported. 1946 */ 1947 if (*errp) 1948 sctp_chunk_free(*errp); 1949 1950 /* Create an error chunk and fill it in with our payload. */ 1951 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1952 1953 return 0; 1954 } 1955 1956 1957 /* Do not attempt to handle the HOST_NAME parm. However, do 1958 * send back an indicator to the peer. 1959 */ 1960 static int sctp_process_hn_param(const struct sctp_association *asoc, 1961 union sctp_params param, 1962 struct sctp_chunk *chunk, 1963 struct sctp_chunk **errp) 1964 { 1965 __u16 len = ntohs(param.p->length); 1966 1967 /* Processing of the HOST_NAME parameter will generate an 1968 * ABORT. If we've accumulated any non-fatal errors, they 1969 * would be unrecognized parameters and we should not include 1970 * them in the ABORT. 1971 */ 1972 if (*errp) 1973 sctp_chunk_free(*errp); 1974 1975 *errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_DNS_FAILED, 1976 param.v, len, 0); 1977 1978 /* Stop processing this chunk. */ 1979 return 0; 1980 } 1981 1982 static int sctp_verify_ext_param(struct net *net, 1983 const struct sctp_endpoint *ep, 1984 union sctp_params param) 1985 { 1986 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 1987 int have_asconf = 0; 1988 int have_auth = 0; 1989 int i; 1990 1991 for (i = 0; i < num_ext; i++) { 1992 switch (param.ext->chunks[i]) { 1993 case SCTP_CID_AUTH: 1994 have_auth = 1; 1995 break; 1996 case SCTP_CID_ASCONF: 1997 case SCTP_CID_ASCONF_ACK: 1998 have_asconf = 1; 1999 break; 2000 } 2001 } 2002 2003 /* ADD-IP Security: The draft requires us to ABORT or ignore the 2004 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 2005 * only if ADD-IP is turned on and we are not backward-compatible 2006 * mode. 2007 */ 2008 if (net->sctp.addip_noauth) 2009 return 1; 2010 2011 if (ep->asconf_enable && !have_auth && have_asconf) 2012 return 0; 2013 2014 return 1; 2015 } 2016 2017 static void sctp_process_ext_param(struct sctp_association *asoc, 2018 union sctp_params param) 2019 { 2020 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2021 int i; 2022 2023 for (i = 0; i < num_ext; i++) { 2024 switch (param.ext->chunks[i]) { 2025 case SCTP_CID_RECONF: 2026 if (asoc->ep->reconf_enable) 2027 asoc->peer.reconf_capable = 1; 2028 break; 2029 case SCTP_CID_FWD_TSN: 2030 if (asoc->ep->prsctp_enable) 2031 asoc->peer.prsctp_capable = 1; 2032 break; 2033 case SCTP_CID_AUTH: 2034 /* if the peer reports AUTH, assume that he 2035 * supports AUTH. 2036 */ 2037 if (asoc->ep->auth_enable) 2038 asoc->peer.auth_capable = 1; 2039 break; 2040 case SCTP_CID_ASCONF: 2041 case SCTP_CID_ASCONF_ACK: 2042 if (asoc->ep->asconf_enable) 2043 asoc->peer.asconf_capable = 1; 2044 break; 2045 case SCTP_CID_I_DATA: 2046 if (asoc->ep->intl_enable) 2047 asoc->peer.intl_capable = 1; 2048 break; 2049 default: 2050 break; 2051 } 2052 } 2053 } 2054 2055 /* RFC 3.2.1 & the Implementers Guide 2.2. 2056 * 2057 * The Parameter Types are encoded such that the 2058 * highest-order two bits specify the action that must be 2059 * taken if the processing endpoint does not recognize the 2060 * Parameter Type. 2061 * 2062 * 00 - Stop processing this parameter; do not process any further 2063 * parameters within this chunk 2064 * 2065 * 01 - Stop processing this parameter, do not process any further 2066 * parameters within this chunk, and report the unrecognized 2067 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2068 * 2069 * 10 - Skip this parameter and continue processing. 2070 * 2071 * 11 - Skip this parameter and continue processing but 2072 * report the unrecognized parameter in an 2073 * 'Unrecognized Parameter' ERROR chunk. 2074 * 2075 * Return value: 2076 * SCTP_IERROR_NO_ERROR - continue with the chunk 2077 * SCTP_IERROR_ERROR - stop and report an error. 2078 * SCTP_IERROR_NOMEME - out of memory. 2079 */ 2080 static enum sctp_ierror sctp_process_unk_param( 2081 const struct sctp_association *asoc, 2082 union sctp_params param, 2083 struct sctp_chunk *chunk, 2084 struct sctp_chunk **errp) 2085 { 2086 int retval = SCTP_IERROR_NO_ERROR; 2087 2088 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2089 case SCTP_PARAM_ACTION_DISCARD: 2090 retval = SCTP_IERROR_ERROR; 2091 break; 2092 case SCTP_PARAM_ACTION_SKIP: 2093 break; 2094 case SCTP_PARAM_ACTION_DISCARD_ERR: 2095 retval = SCTP_IERROR_ERROR; 2096 fallthrough; 2097 case SCTP_PARAM_ACTION_SKIP_ERR: 2098 /* Make an ERROR chunk, preparing enough room for 2099 * returning multiple unknown parameters. 2100 */ 2101 if (!*errp) { 2102 *errp = sctp_make_op_error_limited(asoc, chunk); 2103 if (!*errp) { 2104 /* If there is no memory for generating the 2105 * ERROR report as specified, an ABORT will be 2106 * triggered to the peer and the association 2107 * won't be established. 2108 */ 2109 retval = SCTP_IERROR_NOMEM; 2110 break; 2111 } 2112 } 2113 2114 if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2115 ntohs(param.p->length))) 2116 sctp_addto_chunk(*errp, ntohs(param.p->length), 2117 param.v); 2118 break; 2119 default: 2120 break; 2121 } 2122 2123 return retval; 2124 } 2125 2126 /* Verify variable length parameters 2127 * Return values: 2128 * SCTP_IERROR_ABORT - trigger an ABORT 2129 * SCTP_IERROR_NOMEM - out of memory (abort) 2130 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2131 * SCTP_IERROR_NO_ERROR - continue with the chunk 2132 */ 2133 static enum sctp_ierror sctp_verify_param(struct net *net, 2134 const struct sctp_endpoint *ep, 2135 const struct sctp_association *asoc, 2136 union sctp_params param, 2137 enum sctp_cid cid, 2138 struct sctp_chunk *chunk, 2139 struct sctp_chunk **err_chunk) 2140 { 2141 struct sctp_hmac_algo_param *hmacs; 2142 int retval = SCTP_IERROR_NO_ERROR; 2143 __u16 n_elt, id = 0; 2144 int i; 2145 2146 /* FIXME - This routine is not looking at each parameter per the 2147 * chunk type, i.e., unrecognized parameters should be further 2148 * identified based on the chunk id. 2149 */ 2150 2151 switch (param.p->type) { 2152 case SCTP_PARAM_IPV4_ADDRESS: 2153 case SCTP_PARAM_IPV6_ADDRESS: 2154 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2155 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2156 case SCTP_PARAM_STATE_COOKIE: 2157 case SCTP_PARAM_HEARTBEAT_INFO: 2158 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2159 case SCTP_PARAM_ECN_CAPABLE: 2160 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2161 break; 2162 2163 case SCTP_PARAM_SUPPORTED_EXT: 2164 if (!sctp_verify_ext_param(net, ep, param)) 2165 return SCTP_IERROR_ABORT; 2166 break; 2167 2168 case SCTP_PARAM_SET_PRIMARY: 2169 if (ep->asconf_enable) 2170 break; 2171 goto unhandled; 2172 2173 case SCTP_PARAM_HOST_NAME_ADDRESS: 2174 /* Tell the peer, we won't support this param. */ 2175 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2176 retval = SCTP_IERROR_ABORT; 2177 break; 2178 2179 case SCTP_PARAM_FWD_TSN_SUPPORT: 2180 if (ep->prsctp_enable) 2181 break; 2182 goto unhandled; 2183 2184 case SCTP_PARAM_RANDOM: 2185 if (!ep->auth_enable) 2186 goto unhandled; 2187 2188 /* SCTP-AUTH: Secion 6.1 2189 * If the random number is not 32 byte long the association 2190 * MUST be aborted. The ABORT chunk SHOULD contain the error 2191 * cause 'Protocol Violation'. 2192 */ 2193 if (SCTP_AUTH_RANDOM_LENGTH != ntohs(param.p->length) - 2194 sizeof(struct sctp_paramhdr)) { 2195 sctp_process_inv_paramlength(asoc, param.p, 2196 chunk, err_chunk); 2197 retval = SCTP_IERROR_ABORT; 2198 } 2199 break; 2200 2201 case SCTP_PARAM_CHUNKS: 2202 if (!ep->auth_enable) 2203 goto unhandled; 2204 2205 /* SCTP-AUTH: Section 3.2 2206 * The CHUNKS parameter MUST be included once in the INIT or 2207 * INIT-ACK chunk if the sender wants to receive authenticated 2208 * chunks. Its maximum length is 260 bytes. 2209 */ 2210 if (260 < ntohs(param.p->length)) { 2211 sctp_process_inv_paramlength(asoc, param.p, 2212 chunk, err_chunk); 2213 retval = SCTP_IERROR_ABORT; 2214 } 2215 break; 2216 2217 case SCTP_PARAM_HMAC_ALGO: 2218 if (!ep->auth_enable) 2219 goto unhandled; 2220 2221 hmacs = (struct sctp_hmac_algo_param *)param.p; 2222 n_elt = (ntohs(param.p->length) - 2223 sizeof(struct sctp_paramhdr)) >> 1; 2224 2225 /* SCTP-AUTH: Section 6.1 2226 * The HMAC algorithm based on SHA-1 MUST be supported and 2227 * included in the HMAC-ALGO parameter. 2228 */ 2229 for (i = 0; i < n_elt; i++) { 2230 id = ntohs(hmacs->hmac_ids[i]); 2231 2232 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2233 break; 2234 } 2235 2236 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2237 sctp_process_inv_paramlength(asoc, param.p, chunk, 2238 err_chunk); 2239 retval = SCTP_IERROR_ABORT; 2240 } 2241 break; 2242 unhandled: 2243 default: 2244 pr_debug("%s: unrecognized param:%d for chunk:%d\n", 2245 __func__, ntohs(param.p->type), cid); 2246 2247 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2248 break; 2249 } 2250 return retval; 2251 } 2252 2253 /* Verify the INIT packet before we process it. */ 2254 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 2255 const struct sctp_association *asoc, enum sctp_cid cid, 2256 struct sctp_init_chunk *peer_init, 2257 struct sctp_chunk *chunk, struct sctp_chunk **errp) 2258 { 2259 union sctp_params param; 2260 bool has_cookie = false; 2261 int result; 2262 2263 /* Check for missing mandatory parameters. Note: Initial TSN is 2264 * also mandatory, but is not checked here since the valid range 2265 * is 0..2**32-1. RFC4960, section 3.3.3. 2266 */ 2267 if (peer_init->init_hdr.num_outbound_streams == 0 || 2268 peer_init->init_hdr.num_inbound_streams == 0 || 2269 peer_init->init_hdr.init_tag == 0 || 2270 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) 2271 return sctp_process_inv_mandatory(asoc, chunk, errp); 2272 2273 sctp_walk_params(param, peer_init, init_hdr.params) { 2274 if (param.p->type == SCTP_PARAM_STATE_COOKIE) 2275 has_cookie = true; 2276 } 2277 2278 /* There is a possibility that a parameter length was bad and 2279 * in that case we would have stoped walking the parameters. 2280 * The current param.p would point at the bad one. 2281 * Current consensus on the mailing list is to generate a PROTOCOL 2282 * VIOLATION error. We build the ERROR chunk here and let the normal 2283 * error handling code build and send the packet. 2284 */ 2285 if (param.v != (void *)chunk->chunk_end) 2286 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2287 2288 /* The only missing mandatory param possible today is 2289 * the state cookie for an INIT-ACK chunk. 2290 */ 2291 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2292 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2293 chunk, errp); 2294 2295 /* Verify all the variable length parameters */ 2296 sctp_walk_params(param, peer_init, init_hdr.params) { 2297 result = sctp_verify_param(net, ep, asoc, param, cid, 2298 chunk, errp); 2299 switch (result) { 2300 case SCTP_IERROR_ABORT: 2301 case SCTP_IERROR_NOMEM: 2302 return 0; 2303 case SCTP_IERROR_ERROR: 2304 return 1; 2305 case SCTP_IERROR_NO_ERROR: 2306 default: 2307 break; 2308 } 2309 2310 } /* for (loop through all parameters) */ 2311 2312 return 1; 2313 } 2314 2315 /* Unpack the parameters in an INIT packet into an association. 2316 * Returns 0 on failure, else success. 2317 * FIXME: This is an association method. 2318 */ 2319 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2320 const union sctp_addr *peer_addr, 2321 struct sctp_init_chunk *peer_init, gfp_t gfp) 2322 { 2323 struct sctp_transport *transport; 2324 struct list_head *pos, *temp; 2325 union sctp_params param; 2326 union sctp_addr addr; 2327 struct sctp_af *af; 2328 int src_match = 0; 2329 2330 /* We must include the address that the INIT packet came from. 2331 * This is the only address that matters for an INIT packet. 2332 * When processing a COOKIE ECHO, we retrieve the from address 2333 * of the INIT from the cookie. 2334 */ 2335 2336 /* This implementation defaults to making the first transport 2337 * added as the primary transport. The source address seems to 2338 * be a better choice than any of the embedded addresses. 2339 */ 2340 asoc->encap_port = SCTP_INPUT_CB(chunk->skb)->encap_port; 2341 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2342 goto nomem; 2343 2344 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2345 src_match = 1; 2346 2347 /* Process the initialization parameters. */ 2348 sctp_walk_params(param, peer_init, init_hdr.params) { 2349 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2350 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2351 af = sctp_get_af_specific(param_type2af(param.p->type)); 2352 af->from_addr_param(&addr, param.addr, 2353 chunk->sctp_hdr->source, 0); 2354 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2355 src_match = 1; 2356 } 2357 2358 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2359 goto clean_up; 2360 } 2361 2362 /* source address of chunk may not match any valid address */ 2363 if (!src_match) 2364 goto clean_up; 2365 2366 /* AUTH: After processing the parameters, make sure that we 2367 * have all the required info to potentially do authentications. 2368 */ 2369 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2370 !asoc->peer.peer_hmacs)) 2371 asoc->peer.auth_capable = 0; 2372 2373 /* In a non-backward compatible mode, if the peer claims 2374 * support for ADD-IP but not AUTH, the ADD-IP spec states 2375 * that we MUST ABORT the association. Section 6. The section 2376 * also give us an option to silently ignore the packet, which 2377 * is what we'll do here. 2378 */ 2379 if (!asoc->base.net->sctp.addip_noauth && 2380 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2381 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2382 SCTP_PARAM_DEL_IP | 2383 SCTP_PARAM_SET_PRIMARY); 2384 asoc->peer.asconf_capable = 0; 2385 goto clean_up; 2386 } 2387 2388 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2389 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2390 transport = list_entry(pos, struct sctp_transport, transports); 2391 if (transport->state == SCTP_UNKNOWN) { 2392 sctp_assoc_rm_peer(asoc, transport); 2393 } 2394 } 2395 2396 /* The fixed INIT headers are always in network byte 2397 * order. 2398 */ 2399 asoc->peer.i.init_tag = 2400 ntohl(peer_init->init_hdr.init_tag); 2401 asoc->peer.i.a_rwnd = 2402 ntohl(peer_init->init_hdr.a_rwnd); 2403 asoc->peer.i.num_outbound_streams = 2404 ntohs(peer_init->init_hdr.num_outbound_streams); 2405 asoc->peer.i.num_inbound_streams = 2406 ntohs(peer_init->init_hdr.num_inbound_streams); 2407 asoc->peer.i.initial_tsn = 2408 ntohl(peer_init->init_hdr.initial_tsn); 2409 2410 asoc->strreset_inseq = asoc->peer.i.initial_tsn; 2411 2412 /* Apply the upper bounds for output streams based on peer's 2413 * number of inbound streams. 2414 */ 2415 if (asoc->c.sinit_num_ostreams > 2416 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2417 asoc->c.sinit_num_ostreams = 2418 ntohs(peer_init->init_hdr.num_inbound_streams); 2419 } 2420 2421 if (asoc->c.sinit_max_instreams > 2422 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2423 asoc->c.sinit_max_instreams = 2424 ntohs(peer_init->init_hdr.num_outbound_streams); 2425 } 2426 2427 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2428 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2429 2430 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2431 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2432 2433 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2434 * high (for example, implementations MAY use the size of the receiver 2435 * advertised window). 2436 */ 2437 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2438 transports) { 2439 transport->ssthresh = asoc->peer.i.a_rwnd; 2440 } 2441 2442 /* Set up the TSN tracking pieces. */ 2443 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2444 asoc->peer.i.initial_tsn, gfp)) 2445 goto clean_up; 2446 2447 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2448 * 2449 * The stream sequence number in all the streams shall start 2450 * from 0 when the association is established. Also, when the 2451 * stream sequence number reaches the value 65535 the next 2452 * stream sequence number shall be set to 0. 2453 */ 2454 2455 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams, 2456 asoc->c.sinit_max_instreams, gfp)) 2457 goto clean_up; 2458 2459 /* Update frag_point when stream_interleave may get changed. */ 2460 sctp_assoc_update_frag_point(asoc); 2461 2462 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp)) 2463 goto clean_up; 2464 2465 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2466 * 2467 * When an endpoint has an ASCONF signaled change to be sent to the 2468 * remote endpoint it should do the following: 2469 * ... 2470 * A2) A serial number should be assigned to the Chunk. The serial 2471 * number should be a monotonically increasing number. All serial 2472 * numbers are defined to be initialized at the start of the 2473 * association to the same value as the Initial TSN. 2474 */ 2475 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2476 return 1; 2477 2478 clean_up: 2479 /* Release the transport structures. */ 2480 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2481 transport = list_entry(pos, struct sctp_transport, transports); 2482 if (transport->state != SCTP_ACTIVE) 2483 sctp_assoc_rm_peer(asoc, transport); 2484 } 2485 2486 nomem: 2487 return 0; 2488 } 2489 2490 2491 /* Update asoc with the option described in param. 2492 * 2493 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2494 * 2495 * asoc is the association to update. 2496 * param is the variable length parameter to use for update. 2497 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2498 * If the current packet is an INIT we want to minimize the amount of 2499 * work we do. In particular, we should not build transport 2500 * structures for the addresses. 2501 */ 2502 static int sctp_process_param(struct sctp_association *asoc, 2503 union sctp_params param, 2504 const union sctp_addr *peer_addr, 2505 gfp_t gfp) 2506 { 2507 struct sctp_endpoint *ep = asoc->ep; 2508 union sctp_addr_param *addr_param; 2509 struct net *net = asoc->base.net; 2510 struct sctp_transport *t; 2511 enum sctp_scope scope; 2512 union sctp_addr addr; 2513 struct sctp_af *af; 2514 int retval = 1, i; 2515 u32 stale; 2516 __u16 sat; 2517 2518 /* We maintain all INIT parameters in network byte order all the 2519 * time. This allows us to not worry about whether the parameters 2520 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2521 */ 2522 switch (param.p->type) { 2523 case SCTP_PARAM_IPV6_ADDRESS: 2524 if (PF_INET6 != asoc->base.sk->sk_family) 2525 break; 2526 goto do_addr_param; 2527 2528 case SCTP_PARAM_IPV4_ADDRESS: 2529 /* v4 addresses are not allowed on v6-only socket */ 2530 if (ipv6_only_sock(asoc->base.sk)) 2531 break; 2532 do_addr_param: 2533 af = sctp_get_af_specific(param_type2af(param.p->type)); 2534 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); 2535 scope = sctp_scope(peer_addr); 2536 if (sctp_in_scope(net, &addr, scope)) 2537 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2538 return 0; 2539 break; 2540 2541 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2542 if (!net->sctp.cookie_preserve_enable) 2543 break; 2544 2545 stale = ntohl(param.life->lifespan_increment); 2546 2547 /* Suggested Cookie Life span increment's unit is msec, 2548 * (1/1000sec). 2549 */ 2550 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale); 2551 break; 2552 2553 case SCTP_PARAM_HOST_NAME_ADDRESS: 2554 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__); 2555 break; 2556 2557 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2558 /* Turn off the default values first so we'll know which 2559 * ones are really set by the peer. 2560 */ 2561 asoc->peer.ipv4_address = 0; 2562 asoc->peer.ipv6_address = 0; 2563 2564 /* Assume that peer supports the address family 2565 * by which it sends a packet. 2566 */ 2567 if (peer_addr->sa.sa_family == AF_INET6) 2568 asoc->peer.ipv6_address = 1; 2569 else if (peer_addr->sa.sa_family == AF_INET) 2570 asoc->peer.ipv4_address = 1; 2571 2572 /* Cycle through address types; avoid divide by 0. */ 2573 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2574 if (sat) 2575 sat /= sizeof(__u16); 2576 2577 for (i = 0; i < sat; ++i) { 2578 switch (param.sat->types[i]) { 2579 case SCTP_PARAM_IPV4_ADDRESS: 2580 asoc->peer.ipv4_address = 1; 2581 break; 2582 2583 case SCTP_PARAM_IPV6_ADDRESS: 2584 if (PF_INET6 == asoc->base.sk->sk_family) 2585 asoc->peer.ipv6_address = 1; 2586 break; 2587 2588 case SCTP_PARAM_HOST_NAME_ADDRESS: 2589 asoc->peer.hostname_address = 1; 2590 break; 2591 2592 default: /* Just ignore anything else. */ 2593 break; 2594 } 2595 } 2596 break; 2597 2598 case SCTP_PARAM_STATE_COOKIE: 2599 asoc->peer.cookie_len = 2600 ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2601 kfree(asoc->peer.cookie); 2602 asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp); 2603 if (!asoc->peer.cookie) 2604 retval = 0; 2605 break; 2606 2607 case SCTP_PARAM_HEARTBEAT_INFO: 2608 /* Would be odd to receive, but it causes no problems. */ 2609 break; 2610 2611 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2612 /* Rejected during verify stage. */ 2613 break; 2614 2615 case SCTP_PARAM_ECN_CAPABLE: 2616 if (asoc->ep->ecn_enable) { 2617 asoc->peer.ecn_capable = 1; 2618 break; 2619 } 2620 /* Fall Through */ 2621 goto fall_through; 2622 2623 2624 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2625 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2626 break; 2627 2628 case SCTP_PARAM_SET_PRIMARY: 2629 if (!ep->asconf_enable) 2630 goto fall_through; 2631 2632 addr_param = param.v + sizeof(struct sctp_addip_param); 2633 2634 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 2635 if (af == NULL) 2636 break; 2637 2638 af->from_addr_param(&addr, addr_param, 2639 htons(asoc->peer.port), 0); 2640 2641 /* if the address is invalid, we can't process it. 2642 * XXX: see spec for what to do. 2643 */ 2644 if (!af->addr_valid(&addr, NULL, NULL)) 2645 break; 2646 2647 t = sctp_assoc_lookup_paddr(asoc, &addr); 2648 if (!t) 2649 break; 2650 2651 sctp_assoc_set_primary(asoc, t); 2652 break; 2653 2654 case SCTP_PARAM_SUPPORTED_EXT: 2655 sctp_process_ext_param(asoc, param); 2656 break; 2657 2658 case SCTP_PARAM_FWD_TSN_SUPPORT: 2659 if (asoc->ep->prsctp_enable) { 2660 asoc->peer.prsctp_capable = 1; 2661 break; 2662 } 2663 /* Fall Through */ 2664 goto fall_through; 2665 2666 case SCTP_PARAM_RANDOM: 2667 if (!ep->auth_enable) 2668 goto fall_through; 2669 2670 /* Save peer's random parameter */ 2671 kfree(asoc->peer.peer_random); 2672 asoc->peer.peer_random = kmemdup(param.p, 2673 ntohs(param.p->length), gfp); 2674 if (!asoc->peer.peer_random) { 2675 retval = 0; 2676 break; 2677 } 2678 break; 2679 2680 case SCTP_PARAM_HMAC_ALGO: 2681 if (!ep->auth_enable) 2682 goto fall_through; 2683 2684 /* Save peer's HMAC list */ 2685 kfree(asoc->peer.peer_hmacs); 2686 asoc->peer.peer_hmacs = kmemdup(param.p, 2687 ntohs(param.p->length), gfp); 2688 if (!asoc->peer.peer_hmacs) { 2689 retval = 0; 2690 break; 2691 } 2692 2693 /* Set the default HMAC the peer requested*/ 2694 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2695 break; 2696 2697 case SCTP_PARAM_CHUNKS: 2698 if (!ep->auth_enable) 2699 goto fall_through; 2700 2701 kfree(asoc->peer.peer_chunks); 2702 asoc->peer.peer_chunks = kmemdup(param.p, 2703 ntohs(param.p->length), gfp); 2704 if (!asoc->peer.peer_chunks) 2705 retval = 0; 2706 break; 2707 fall_through: 2708 default: 2709 /* Any unrecognized parameters should have been caught 2710 * and handled by sctp_verify_param() which should be 2711 * called prior to this routine. Simply log the error 2712 * here. 2713 */ 2714 pr_debug("%s: ignoring param:%d for association:%p.\n", 2715 __func__, ntohs(param.p->type), asoc); 2716 break; 2717 } 2718 2719 return retval; 2720 } 2721 2722 /* Select a new verification tag. */ 2723 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2724 { 2725 /* I believe that this random number generator complies with RFC1750. 2726 * A tag of 0 is reserved for special cases (e.g. INIT). 2727 */ 2728 __u32 x; 2729 2730 do { 2731 get_random_bytes(&x, sizeof(__u32)); 2732 } while (x == 0); 2733 2734 return x; 2735 } 2736 2737 /* Select an initial TSN to send during startup. */ 2738 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2739 { 2740 __u32 retval; 2741 2742 get_random_bytes(&retval, sizeof(__u32)); 2743 return retval; 2744 } 2745 2746 /* 2747 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2748 * 0 1 2 3 2749 * 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 2750 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2751 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2752 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2753 * | Serial Number | 2754 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2755 * | Address Parameter | 2756 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2757 * | ASCONF Parameter #1 | 2758 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2759 * \ \ 2760 * / .... / 2761 * \ \ 2762 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2763 * | ASCONF Parameter #N | 2764 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2765 * 2766 * Address Parameter and other parameter will not be wrapped in this function 2767 */ 2768 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2769 union sctp_addr *addr, 2770 int vparam_len) 2771 { 2772 struct sctp_addiphdr asconf; 2773 struct sctp_chunk *retval; 2774 int length = sizeof(asconf) + vparam_len; 2775 union sctp_addr_param addrparam; 2776 int addrlen; 2777 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2778 2779 addrlen = af->to_addr_param(addr, &addrparam); 2780 if (!addrlen) 2781 return NULL; 2782 length += addrlen; 2783 2784 /* Create the chunk. */ 2785 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length, 2786 GFP_ATOMIC); 2787 if (!retval) 2788 return NULL; 2789 2790 asconf.serial = htonl(asoc->addip_serial++); 2791 2792 retval->subh.addip_hdr = 2793 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2794 retval->param_hdr.v = 2795 sctp_addto_chunk(retval, addrlen, &addrparam); 2796 2797 return retval; 2798 } 2799 2800 /* ADDIP 2801 * 3.2.1 Add IP Address 2802 * 0 1 2 3 2803 * 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 2804 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2805 * | Type = 0xC001 | Length = Variable | 2806 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2807 * | ASCONF-Request Correlation ID | 2808 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2809 * | Address Parameter | 2810 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2811 * 2812 * 3.2.2 Delete IP Address 2813 * 0 1 2 3 2814 * 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 2815 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2816 * | Type = 0xC002 | Length = Variable | 2817 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2818 * | ASCONF-Request Correlation ID | 2819 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2820 * | Address Parameter | 2821 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2822 * 2823 */ 2824 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2825 union sctp_addr *laddr, 2826 struct sockaddr *addrs, 2827 int addrcnt, __be16 flags) 2828 { 2829 union sctp_addr_param addr_param; 2830 struct sctp_addip_param param; 2831 int paramlen = sizeof(param); 2832 struct sctp_chunk *retval; 2833 int addr_param_len = 0; 2834 union sctp_addr *addr; 2835 int totallen = 0, i; 2836 int del_pickup = 0; 2837 struct sctp_af *af; 2838 void *addr_buf; 2839 2840 /* Get total length of all the address parameters. */ 2841 addr_buf = addrs; 2842 for (i = 0; i < addrcnt; i++) { 2843 addr = addr_buf; 2844 af = sctp_get_af_specific(addr->v4.sin_family); 2845 addr_param_len = af->to_addr_param(addr, &addr_param); 2846 2847 totallen += paramlen; 2848 totallen += addr_param_len; 2849 2850 addr_buf += af->sockaddr_len; 2851 if (asoc->asconf_addr_del_pending && !del_pickup) { 2852 /* reuse the parameter length from the same scope one */ 2853 totallen += paramlen; 2854 totallen += addr_param_len; 2855 del_pickup = 1; 2856 2857 pr_debug("%s: picked same-scope del_pending addr, " 2858 "totallen for all addresses is %d\n", 2859 __func__, totallen); 2860 } 2861 } 2862 2863 /* Create an asconf chunk with the required length. */ 2864 retval = sctp_make_asconf(asoc, laddr, totallen); 2865 if (!retval) 2866 return NULL; 2867 2868 /* Add the address parameters to the asconf chunk. */ 2869 addr_buf = addrs; 2870 for (i = 0; i < addrcnt; i++) { 2871 addr = addr_buf; 2872 af = sctp_get_af_specific(addr->v4.sin_family); 2873 addr_param_len = af->to_addr_param(addr, &addr_param); 2874 param.param_hdr.type = flags; 2875 param.param_hdr.length = htons(paramlen + addr_param_len); 2876 param.crr_id = htonl(i); 2877 2878 sctp_addto_chunk(retval, paramlen, ¶m); 2879 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2880 2881 addr_buf += af->sockaddr_len; 2882 } 2883 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2884 addr = asoc->asconf_addr_del_pending; 2885 af = sctp_get_af_specific(addr->v4.sin_family); 2886 addr_param_len = af->to_addr_param(addr, &addr_param); 2887 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2888 param.param_hdr.length = htons(paramlen + addr_param_len); 2889 param.crr_id = htonl(i); 2890 2891 sctp_addto_chunk(retval, paramlen, ¶m); 2892 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2893 } 2894 return retval; 2895 } 2896 2897 /* ADDIP 2898 * 3.2.4 Set Primary IP Address 2899 * 0 1 2 3 2900 * 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 2901 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2902 * | Type =0xC004 | Length = Variable | 2903 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2904 * | ASCONF-Request Correlation ID | 2905 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2906 * | Address Parameter | 2907 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2908 * 2909 * Create an ASCONF chunk with Set Primary IP address parameter. 2910 */ 2911 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2912 union sctp_addr *addr) 2913 { 2914 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2915 union sctp_addr_param addrparam; 2916 struct sctp_addip_param param; 2917 struct sctp_chunk *retval; 2918 int len = sizeof(param); 2919 int addrlen; 2920 2921 addrlen = af->to_addr_param(addr, &addrparam); 2922 if (!addrlen) 2923 return NULL; 2924 len += addrlen; 2925 2926 /* Create the chunk and make asconf header. */ 2927 retval = sctp_make_asconf(asoc, addr, len); 2928 if (!retval) 2929 return NULL; 2930 2931 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2932 param.param_hdr.length = htons(len); 2933 param.crr_id = 0; 2934 2935 sctp_addto_chunk(retval, sizeof(param), ¶m); 2936 sctp_addto_chunk(retval, addrlen, &addrparam); 2937 2938 return retval; 2939 } 2940 2941 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2942 * 0 1 2 3 2943 * 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 2944 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2945 * | Type = 0x80 | Chunk Flags | Chunk Length | 2946 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2947 * | Serial Number | 2948 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2949 * | ASCONF Parameter Response#1 | 2950 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2951 * \ \ 2952 * / .... / 2953 * \ \ 2954 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2955 * | ASCONF Parameter Response#N | 2956 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2957 * 2958 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2959 */ 2960 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2961 __u32 serial, int vparam_len) 2962 { 2963 struct sctp_addiphdr asconf; 2964 struct sctp_chunk *retval; 2965 int length = sizeof(asconf) + vparam_len; 2966 2967 /* Create the chunk. */ 2968 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length, 2969 GFP_ATOMIC); 2970 if (!retval) 2971 return NULL; 2972 2973 asconf.serial = htonl(serial); 2974 2975 retval->subh.addip_hdr = 2976 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2977 2978 return retval; 2979 } 2980 2981 /* Add response parameters to an ASCONF_ACK chunk. */ 2982 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2983 __be16 err_code, 2984 struct sctp_addip_param *asconf_param) 2985 { 2986 struct sctp_addip_param ack_param; 2987 struct sctp_errhdr err_param; 2988 int asconf_param_len = 0; 2989 int err_param_len = 0; 2990 __be16 response_type; 2991 2992 if (SCTP_ERROR_NO_ERROR == err_code) { 2993 response_type = SCTP_PARAM_SUCCESS_REPORT; 2994 } else { 2995 response_type = SCTP_PARAM_ERR_CAUSE; 2996 err_param_len = sizeof(err_param); 2997 if (asconf_param) 2998 asconf_param_len = 2999 ntohs(asconf_param->param_hdr.length); 3000 } 3001 3002 /* Add Success Indication or Error Cause Indication parameter. */ 3003 ack_param.param_hdr.type = response_type; 3004 ack_param.param_hdr.length = htons(sizeof(ack_param) + 3005 err_param_len + 3006 asconf_param_len); 3007 ack_param.crr_id = crr_id; 3008 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 3009 3010 if (SCTP_ERROR_NO_ERROR == err_code) 3011 return; 3012 3013 /* Add Error Cause parameter. */ 3014 err_param.cause = err_code; 3015 err_param.length = htons(err_param_len + asconf_param_len); 3016 sctp_addto_chunk(chunk, err_param_len, &err_param); 3017 3018 /* Add the failed TLV copied from ASCONF chunk. */ 3019 if (asconf_param) 3020 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 3021 } 3022 3023 /* Process a asconf parameter. */ 3024 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 3025 struct sctp_chunk *asconf, 3026 struct sctp_addip_param *asconf_param) 3027 { 3028 union sctp_addr_param *addr_param; 3029 struct sctp_transport *peer; 3030 union sctp_addr addr; 3031 struct sctp_af *af; 3032 3033 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3034 3035 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 3036 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 3037 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 3038 return SCTP_ERROR_UNKNOWN_PARAM; 3039 3040 switch (addr_param->p.type) { 3041 case SCTP_PARAM_IPV6_ADDRESS: 3042 if (!asoc->peer.ipv6_address) 3043 return SCTP_ERROR_DNS_FAILED; 3044 break; 3045 case SCTP_PARAM_IPV4_ADDRESS: 3046 if (!asoc->peer.ipv4_address) 3047 return SCTP_ERROR_DNS_FAILED; 3048 break; 3049 default: 3050 return SCTP_ERROR_DNS_FAILED; 3051 } 3052 3053 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3054 if (unlikely(!af)) 3055 return SCTP_ERROR_DNS_FAILED; 3056 3057 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); 3058 3059 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3060 * or multicast address. 3061 * (note: wildcard is permitted and requires special handling so 3062 * make sure we check for that) 3063 */ 3064 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3065 return SCTP_ERROR_DNS_FAILED; 3066 3067 switch (asconf_param->param_hdr.type) { 3068 case SCTP_PARAM_ADD_IP: 3069 /* Section 4.2.1: 3070 * If the address 0.0.0.0 or ::0 is provided, the source 3071 * address of the packet MUST be added. 3072 */ 3073 if (af->is_any(&addr)) 3074 memcpy(&addr, &asconf->source, sizeof(addr)); 3075 3076 if (security_sctp_bind_connect(asoc->ep->base.sk, 3077 SCTP_PARAM_ADD_IP, 3078 (struct sockaddr *)&addr, 3079 af->sockaddr_len)) 3080 return SCTP_ERROR_REQ_REFUSED; 3081 3082 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3083 * request and does not have the local resources to add this 3084 * new address to the association, it MUST return an Error 3085 * Cause TLV set to the new error code 'Operation Refused 3086 * Due to Resource Shortage'. 3087 */ 3088 3089 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3090 if (!peer) 3091 return SCTP_ERROR_RSRC_LOW; 3092 3093 /* Start the heartbeat timer. */ 3094 sctp_transport_reset_hb_timer(peer); 3095 asoc->new_transport = peer; 3096 break; 3097 case SCTP_PARAM_DEL_IP: 3098 /* ADDIP 4.3 D7) If a request is received to delete the 3099 * last remaining IP address of a peer endpoint, the receiver 3100 * MUST send an Error Cause TLV with the error cause set to the 3101 * new error code 'Request to Delete Last Remaining IP Address'. 3102 */ 3103 if (asoc->peer.transport_count == 1) 3104 return SCTP_ERROR_DEL_LAST_IP; 3105 3106 /* ADDIP 4.3 D8) If a request is received to delete an IP 3107 * address which is also the source address of the IP packet 3108 * which contained the ASCONF chunk, the receiver MUST reject 3109 * this request. To reject the request the receiver MUST send 3110 * an Error Cause TLV set to the new error code 'Request to 3111 * Delete Source IP Address' 3112 */ 3113 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3114 return SCTP_ERROR_DEL_SRC_IP; 3115 3116 /* Section 4.2.2 3117 * If the address 0.0.0.0 or ::0 is provided, all 3118 * addresses of the peer except the source address of the 3119 * packet MUST be deleted. 3120 */ 3121 if (af->is_any(&addr)) { 3122 sctp_assoc_set_primary(asoc, asconf->transport); 3123 sctp_assoc_del_nonprimary_peers(asoc, 3124 asconf->transport); 3125 return SCTP_ERROR_NO_ERROR; 3126 } 3127 3128 /* If the address is not part of the association, the 3129 * ASCONF-ACK with Error Cause Indication Parameter 3130 * which including cause of Unresolvable Address should 3131 * be sent. 3132 */ 3133 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3134 if (!peer) 3135 return SCTP_ERROR_DNS_FAILED; 3136 3137 sctp_assoc_rm_peer(asoc, peer); 3138 break; 3139 case SCTP_PARAM_SET_PRIMARY: 3140 /* ADDIP Section 4.2.4 3141 * If the address 0.0.0.0 or ::0 is provided, the receiver 3142 * MAY mark the source address of the packet as its 3143 * primary. 3144 */ 3145 if (af->is_any(&addr)) 3146 memcpy(&addr, sctp_source(asconf), sizeof(addr)); 3147 3148 if (security_sctp_bind_connect(asoc->ep->base.sk, 3149 SCTP_PARAM_SET_PRIMARY, 3150 (struct sockaddr *)&addr, 3151 af->sockaddr_len)) 3152 return SCTP_ERROR_REQ_REFUSED; 3153 3154 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3155 if (!peer) 3156 return SCTP_ERROR_DNS_FAILED; 3157 3158 sctp_assoc_set_primary(asoc, peer); 3159 break; 3160 } 3161 3162 return SCTP_ERROR_NO_ERROR; 3163 } 3164 3165 /* Verify the ASCONF packet before we process it. */ 3166 bool sctp_verify_asconf(const struct sctp_association *asoc, 3167 struct sctp_chunk *chunk, bool addr_param_needed, 3168 struct sctp_paramhdr **errp) 3169 { 3170 struct sctp_addip_chunk *addip; 3171 bool addr_param_seen = false; 3172 union sctp_params param; 3173 3174 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr; 3175 sctp_walk_params(param, addip, addip_hdr.params) { 3176 size_t length = ntohs(param.p->length); 3177 3178 *errp = param.p; 3179 switch (param.p->type) { 3180 case SCTP_PARAM_ERR_CAUSE: 3181 break; 3182 case SCTP_PARAM_IPV4_ADDRESS: 3183 if (length != sizeof(struct sctp_ipv4addr_param)) 3184 return false; 3185 /* ensure there is only one addr param and it's in the 3186 * beginning of addip_hdr params, or we reject it. 3187 */ 3188 if (param.v != addip->addip_hdr.params) 3189 return false; 3190 addr_param_seen = true; 3191 break; 3192 case SCTP_PARAM_IPV6_ADDRESS: 3193 if (length != sizeof(struct sctp_ipv6addr_param)) 3194 return false; 3195 if (param.v != addip->addip_hdr.params) 3196 return false; 3197 addr_param_seen = true; 3198 break; 3199 case SCTP_PARAM_ADD_IP: 3200 case SCTP_PARAM_DEL_IP: 3201 case SCTP_PARAM_SET_PRIMARY: 3202 /* In ASCONF chunks, these need to be first. */ 3203 if (addr_param_needed && !addr_param_seen) 3204 return false; 3205 length = ntohs(param.addip->param_hdr.length); 3206 if (length < sizeof(struct sctp_addip_param) + 3207 sizeof(**errp)) 3208 return false; 3209 break; 3210 case SCTP_PARAM_SUCCESS_REPORT: 3211 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3212 if (length != sizeof(struct sctp_addip_param)) 3213 return false; 3214 break; 3215 default: 3216 /* This is unknown to us, reject! */ 3217 return false; 3218 } 3219 } 3220 3221 /* Remaining sanity checks. */ 3222 if (addr_param_needed && !addr_param_seen) 3223 return false; 3224 if (!addr_param_needed && addr_param_seen) 3225 return false; 3226 if (param.v != chunk->chunk_end) 3227 return false; 3228 3229 return true; 3230 } 3231 3232 /* Process an incoming ASCONF chunk with the next expected serial no. and 3233 * return an ASCONF_ACK chunk to be sent in response. 3234 */ 3235 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3236 struct sctp_chunk *asconf) 3237 { 3238 union sctp_addr_param *addr_param; 3239 struct sctp_addip_chunk *addip; 3240 struct sctp_chunk *asconf_ack; 3241 bool all_param_pass = true; 3242 struct sctp_addiphdr *hdr; 3243 int length = 0, chunk_len; 3244 union sctp_params param; 3245 __be16 err_code; 3246 __u32 serial; 3247 3248 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr; 3249 chunk_len = ntohs(asconf->chunk_hdr->length) - 3250 sizeof(struct sctp_chunkhdr); 3251 hdr = (struct sctp_addiphdr *)asconf->skb->data; 3252 serial = ntohl(hdr->serial); 3253 3254 /* Skip the addiphdr and store a pointer to address parameter. */ 3255 length = sizeof(*hdr); 3256 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3257 chunk_len -= length; 3258 3259 /* Skip the address parameter and store a pointer to the first 3260 * asconf parameter. 3261 */ 3262 length = ntohs(addr_param->p.length); 3263 chunk_len -= length; 3264 3265 /* create an ASCONF_ACK chunk. 3266 * Based on the definitions of parameters, we know that the size of 3267 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3268 * parameters. 3269 */ 3270 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3271 if (!asconf_ack) 3272 goto done; 3273 3274 /* Process the TLVs contained within the ASCONF chunk. */ 3275 sctp_walk_params(param, addip, addip_hdr.params) { 3276 /* Skip preceeding address parameters. */ 3277 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 3278 param.p->type == SCTP_PARAM_IPV6_ADDRESS) 3279 continue; 3280 3281 err_code = sctp_process_asconf_param(asoc, asconf, 3282 param.addip); 3283 /* ADDIP 4.1 A7) 3284 * If an error response is received for a TLV parameter, 3285 * all TLVs with no response before the failed TLV are 3286 * considered successful if not reported. All TLVs after 3287 * the failed response are considered unsuccessful unless 3288 * a specific success indication is present for the parameter. 3289 */ 3290 if (err_code != SCTP_ERROR_NO_ERROR) 3291 all_param_pass = false; 3292 if (!all_param_pass) 3293 sctp_add_asconf_response(asconf_ack, param.addip->crr_id, 3294 err_code, param.addip); 3295 3296 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3297 * an IP address sends an 'Out of Resource' in its response, it 3298 * MUST also fail any subsequent add or delete requests bundled 3299 * in the ASCONF. 3300 */ 3301 if (err_code == SCTP_ERROR_RSRC_LOW) 3302 goto done; 3303 } 3304 done: 3305 asoc->peer.addip_serial++; 3306 3307 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3308 * after freeing the reference to old asconf ack if any. 3309 */ 3310 if (asconf_ack) { 3311 sctp_chunk_hold(asconf_ack); 3312 list_add_tail(&asconf_ack->transmitted_list, 3313 &asoc->asconf_ack_list); 3314 } 3315 3316 return asconf_ack; 3317 } 3318 3319 /* Process a asconf parameter that is successfully acked. */ 3320 static void sctp_asconf_param_success(struct sctp_association *asoc, 3321 struct sctp_addip_param *asconf_param) 3322 { 3323 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3324 union sctp_addr_param *addr_param; 3325 struct sctp_sockaddr_entry *saddr; 3326 struct sctp_transport *transport; 3327 union sctp_addr addr; 3328 struct sctp_af *af; 3329 3330 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3331 3332 /* We have checked the packet before, so we do not check again. */ 3333 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3334 af->from_addr_param(&addr, addr_param, htons(bp->port), 0); 3335 3336 switch (asconf_param->param_hdr.type) { 3337 case SCTP_PARAM_ADD_IP: 3338 /* This is always done in BH context with a socket lock 3339 * held, so the list can not change. 3340 */ 3341 local_bh_disable(); 3342 list_for_each_entry(saddr, &bp->address_list, list) { 3343 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3344 saddr->state = SCTP_ADDR_SRC; 3345 } 3346 local_bh_enable(); 3347 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3348 transports) { 3349 sctp_transport_dst_release(transport); 3350 } 3351 break; 3352 case SCTP_PARAM_DEL_IP: 3353 local_bh_disable(); 3354 sctp_del_bind_addr(bp, &addr); 3355 if (asoc->asconf_addr_del_pending != NULL && 3356 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3357 kfree(asoc->asconf_addr_del_pending); 3358 asoc->asconf_addr_del_pending = NULL; 3359 } 3360 local_bh_enable(); 3361 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3362 transports) { 3363 sctp_transport_dst_release(transport); 3364 } 3365 break; 3366 default: 3367 break; 3368 } 3369 } 3370 3371 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3372 * for the given asconf parameter. If there is no response for this parameter, 3373 * return the error code based on the third argument 'no_err'. 3374 * ADDIP 4.1 3375 * A7) If an error response is received for a TLV parameter, all TLVs with no 3376 * response before the failed TLV are considered successful if not reported. 3377 * All TLVs after the failed response are considered unsuccessful unless a 3378 * specific success indication is present for the parameter. 3379 */ 3380 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3381 struct sctp_addip_param *asconf_param, 3382 int no_err) 3383 { 3384 struct sctp_addip_param *asconf_ack_param; 3385 struct sctp_errhdr *err_param; 3386 int asconf_ack_len; 3387 __be16 err_code; 3388 int length; 3389 3390 if (no_err) 3391 err_code = SCTP_ERROR_NO_ERROR; 3392 else 3393 err_code = SCTP_ERROR_REQ_REFUSED; 3394 3395 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3396 sizeof(struct sctp_chunkhdr); 3397 3398 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3399 * the first asconf_ack parameter. 3400 */ 3401 length = sizeof(struct sctp_addiphdr); 3402 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data + 3403 length); 3404 asconf_ack_len -= length; 3405 3406 while (asconf_ack_len > 0) { 3407 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3408 switch (asconf_ack_param->param_hdr.type) { 3409 case SCTP_PARAM_SUCCESS_REPORT: 3410 return SCTP_ERROR_NO_ERROR; 3411 case SCTP_PARAM_ERR_CAUSE: 3412 length = sizeof(*asconf_ack_param); 3413 err_param = (void *)asconf_ack_param + length; 3414 asconf_ack_len -= length; 3415 if (asconf_ack_len > 0) 3416 return err_param->cause; 3417 else 3418 return SCTP_ERROR_INV_PARAM; 3419 break; 3420 default: 3421 return SCTP_ERROR_INV_PARAM; 3422 } 3423 } 3424 3425 length = ntohs(asconf_ack_param->param_hdr.length); 3426 asconf_ack_param = (void *)asconf_ack_param + length; 3427 asconf_ack_len -= length; 3428 } 3429 3430 return err_code; 3431 } 3432 3433 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3434 int sctp_process_asconf_ack(struct sctp_association *asoc, 3435 struct sctp_chunk *asconf_ack) 3436 { 3437 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3438 struct sctp_addip_param *asconf_param; 3439 __be16 err_code = SCTP_ERROR_NO_ERROR; 3440 union sctp_addr_param *addr_param; 3441 int asconf_len = asconf->skb->len; 3442 int all_param_pass = 0; 3443 int length = 0; 3444 int no_err = 1; 3445 int retval = 0; 3446 3447 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3448 * a pointer to address parameter. 3449 */ 3450 length = sizeof(struct sctp_addip_chunk); 3451 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3452 asconf_len -= length; 3453 3454 /* Skip the address parameter in the last asconf sent and store a 3455 * pointer to the first asconf parameter. 3456 */ 3457 length = ntohs(addr_param->p.length); 3458 asconf_param = (void *)addr_param + length; 3459 asconf_len -= length; 3460 3461 /* ADDIP 4.1 3462 * A8) If there is no response(s) to specific TLV parameter(s), and no 3463 * failures are indicated, then all request(s) are considered 3464 * successful. 3465 */ 3466 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr)) 3467 all_param_pass = 1; 3468 3469 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3470 while (asconf_len > 0) { 3471 if (all_param_pass) 3472 err_code = SCTP_ERROR_NO_ERROR; 3473 else { 3474 err_code = sctp_get_asconf_response(asconf_ack, 3475 asconf_param, 3476 no_err); 3477 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3478 no_err = 0; 3479 } 3480 3481 switch (err_code) { 3482 case SCTP_ERROR_NO_ERROR: 3483 sctp_asconf_param_success(asoc, asconf_param); 3484 break; 3485 3486 case SCTP_ERROR_RSRC_LOW: 3487 retval = 1; 3488 break; 3489 3490 case SCTP_ERROR_UNKNOWN_PARAM: 3491 /* Disable sending this type of asconf parameter in 3492 * future. 3493 */ 3494 asoc->peer.addip_disabled_mask |= 3495 asconf_param->param_hdr.type; 3496 break; 3497 3498 case SCTP_ERROR_REQ_REFUSED: 3499 case SCTP_ERROR_DEL_LAST_IP: 3500 case SCTP_ERROR_DEL_SRC_IP: 3501 default: 3502 break; 3503 } 3504 3505 /* Skip the processed asconf parameter and move to the next 3506 * one. 3507 */ 3508 length = ntohs(asconf_param->param_hdr.length); 3509 asconf_param = (void *)asconf_param + length; 3510 asconf_len -= length; 3511 } 3512 3513 if (no_err && asoc->src_out_of_asoc_ok) { 3514 asoc->src_out_of_asoc_ok = 0; 3515 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3516 } 3517 3518 /* Free the cached last sent asconf chunk. */ 3519 list_del_init(&asconf->transmitted_list); 3520 sctp_chunk_free(asconf); 3521 asoc->addip_last_asconf = NULL; 3522 3523 return retval; 3524 } 3525 3526 /* Make a FWD TSN chunk. */ 3527 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3528 __u32 new_cum_tsn, size_t nstreams, 3529 struct sctp_fwdtsn_skip *skiplist) 3530 { 3531 struct sctp_chunk *retval = NULL; 3532 struct sctp_fwdtsn_hdr ftsn_hdr; 3533 struct sctp_fwdtsn_skip skip; 3534 size_t hint; 3535 int i; 3536 3537 hint = (nstreams + 1) * sizeof(__u32); 3538 3539 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC); 3540 3541 if (!retval) 3542 return NULL; 3543 3544 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3545 retval->subh.fwdtsn_hdr = 3546 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3547 3548 for (i = 0; i < nstreams; i++) { 3549 skip.stream = skiplist[i].stream; 3550 skip.ssn = skiplist[i].ssn; 3551 sctp_addto_chunk(retval, sizeof(skip), &skip); 3552 } 3553 3554 return retval; 3555 } 3556 3557 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc, 3558 __u32 new_cum_tsn, size_t nstreams, 3559 struct sctp_ifwdtsn_skip *skiplist) 3560 { 3561 struct sctp_chunk *retval = NULL; 3562 struct sctp_ifwdtsn_hdr ftsn_hdr; 3563 size_t hint; 3564 3565 hint = (nstreams + 1) * sizeof(__u32); 3566 3567 retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint, 3568 GFP_ATOMIC); 3569 if (!retval) 3570 return NULL; 3571 3572 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3573 retval->subh.ifwdtsn_hdr = 3574 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3575 3576 sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist); 3577 3578 return retval; 3579 } 3580 3581 /* RE-CONFIG 3.1 (RE-CONFIG chunk) 3582 * 0 1 2 3 3583 * 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 3584 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3585 * | Type = 130 | Chunk Flags | Chunk Length | 3586 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3587 * \ \ 3588 * / Re-configuration Parameter / 3589 * \ \ 3590 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3591 * \ \ 3592 * / Re-configuration Parameter (optional) / 3593 * \ \ 3594 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3595 */ 3596 static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc, 3597 int length) 3598 { 3599 struct sctp_reconf_chunk *reconf; 3600 struct sctp_chunk *retval; 3601 3602 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length, 3603 GFP_ATOMIC); 3604 if (!retval) 3605 return NULL; 3606 3607 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr; 3608 retval->param_hdr.v = reconf->params; 3609 3610 return retval; 3611 } 3612 3613 /* RE-CONFIG 4.1 (STREAM OUT RESET) 3614 * 0 1 2 3 3615 * 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 3616 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3617 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N | 3618 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3619 * | Re-configuration Request Sequence Number | 3620 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3621 * | Re-configuration Response Sequence Number | 3622 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3623 * | Sender's Last Assigned TSN | 3624 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3625 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3626 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3627 * / ...... / 3628 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3629 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3630 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3631 * 3632 * RE-CONFIG 4.2 (STREAM IN RESET) 3633 * 0 1 2 3 3634 * 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 3635 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3636 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N | 3637 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3638 * | Re-configuration Request Sequence Number | 3639 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3640 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3641 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3642 * / ...... / 3643 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3644 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3645 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3646 */ 3647 struct sctp_chunk *sctp_make_strreset_req( 3648 const struct sctp_association *asoc, 3649 __u16 stream_num, __be16 *stream_list, 3650 bool out, bool in) 3651 { 3652 __u16 stream_len = stream_num * sizeof(__u16); 3653 struct sctp_strreset_outreq outreq; 3654 struct sctp_strreset_inreq inreq; 3655 struct sctp_chunk *retval; 3656 __u16 outlen, inlen; 3657 3658 outlen = (sizeof(outreq) + stream_len) * out; 3659 inlen = (sizeof(inreq) + stream_len) * in; 3660 3661 retval = sctp_make_reconf(asoc, outlen + inlen); 3662 if (!retval) 3663 return NULL; 3664 3665 if (outlen) { 3666 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST; 3667 outreq.param_hdr.length = htons(outlen); 3668 outreq.request_seq = htonl(asoc->strreset_outseq); 3669 outreq.response_seq = htonl(asoc->strreset_inseq - 1); 3670 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1); 3671 3672 sctp_addto_chunk(retval, sizeof(outreq), &outreq); 3673 3674 if (stream_len) 3675 sctp_addto_chunk(retval, stream_len, stream_list); 3676 } 3677 3678 if (inlen) { 3679 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST; 3680 inreq.param_hdr.length = htons(inlen); 3681 inreq.request_seq = htonl(asoc->strreset_outseq + out); 3682 3683 sctp_addto_chunk(retval, sizeof(inreq), &inreq); 3684 3685 if (stream_len) 3686 sctp_addto_chunk(retval, stream_len, stream_list); 3687 } 3688 3689 return retval; 3690 } 3691 3692 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL) 3693 * 0 1 2 3 3694 * 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 3695 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3696 * | Parameter Type = 15 | Parameter Length = 8 | 3697 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3698 * | Re-configuration Request Sequence Number | 3699 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3700 */ 3701 struct sctp_chunk *sctp_make_strreset_tsnreq( 3702 const struct sctp_association *asoc) 3703 { 3704 struct sctp_strreset_tsnreq tsnreq; 3705 __u16 length = sizeof(tsnreq); 3706 struct sctp_chunk *retval; 3707 3708 retval = sctp_make_reconf(asoc, length); 3709 if (!retval) 3710 return NULL; 3711 3712 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST; 3713 tsnreq.param_hdr.length = htons(length); 3714 tsnreq.request_seq = htonl(asoc->strreset_outseq); 3715 3716 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq); 3717 3718 return retval; 3719 } 3720 3721 /* RE-CONFIG 4.5/4.6 (ADD STREAM) 3722 * 0 1 2 3 3723 * 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 3724 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3725 * | Parameter Type = 17 | Parameter Length = 12 | 3726 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3727 * | Re-configuration Request Sequence Number | 3728 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3729 * | Number of new streams | Reserved | 3730 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3731 */ 3732 struct sctp_chunk *sctp_make_strreset_addstrm( 3733 const struct sctp_association *asoc, 3734 __u16 out, __u16 in) 3735 { 3736 struct sctp_strreset_addstrm addstrm; 3737 __u16 size = sizeof(addstrm); 3738 struct sctp_chunk *retval; 3739 3740 retval = sctp_make_reconf(asoc, (!!out + !!in) * size); 3741 if (!retval) 3742 return NULL; 3743 3744 if (out) { 3745 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS; 3746 addstrm.param_hdr.length = htons(size); 3747 addstrm.number_of_streams = htons(out); 3748 addstrm.request_seq = htonl(asoc->strreset_outseq); 3749 addstrm.reserved = 0; 3750 3751 sctp_addto_chunk(retval, size, &addstrm); 3752 } 3753 3754 if (in) { 3755 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS; 3756 addstrm.param_hdr.length = htons(size); 3757 addstrm.number_of_streams = htons(in); 3758 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out); 3759 addstrm.reserved = 0; 3760 3761 sctp_addto_chunk(retval, size, &addstrm); 3762 } 3763 3764 return retval; 3765 } 3766 3767 /* RE-CONFIG 4.4 (RESP) 3768 * 0 1 2 3 3769 * 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 3770 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3771 * | Parameter Type = 16 | Parameter Length | 3772 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3773 * | Re-configuration Response Sequence Number | 3774 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3775 * | Result | 3776 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3777 */ 3778 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc, 3779 __u32 result, __u32 sn) 3780 { 3781 struct sctp_strreset_resp resp; 3782 __u16 length = sizeof(resp); 3783 struct sctp_chunk *retval; 3784 3785 retval = sctp_make_reconf(asoc, length); 3786 if (!retval) 3787 return NULL; 3788 3789 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3790 resp.param_hdr.length = htons(length); 3791 resp.response_seq = htonl(sn); 3792 resp.result = htonl(result); 3793 3794 sctp_addto_chunk(retval, sizeof(resp), &resp); 3795 3796 return retval; 3797 } 3798 3799 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP) 3800 * 0 1 2 3 3801 * 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 3802 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3803 * | Parameter Type = 16 | Parameter Length | 3804 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3805 * | Re-configuration Response Sequence Number | 3806 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3807 * | Result | 3808 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3809 * | Sender's Next TSN (optional) | 3810 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3811 * | Receiver's Next TSN (optional) | 3812 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3813 */ 3814 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc, 3815 __u32 result, __u32 sn, 3816 __u32 sender_tsn, 3817 __u32 receiver_tsn) 3818 { 3819 struct sctp_strreset_resptsn tsnresp; 3820 __u16 length = sizeof(tsnresp); 3821 struct sctp_chunk *retval; 3822 3823 retval = sctp_make_reconf(asoc, length); 3824 if (!retval) 3825 return NULL; 3826 3827 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3828 tsnresp.param_hdr.length = htons(length); 3829 3830 tsnresp.response_seq = htonl(sn); 3831 tsnresp.result = htonl(result); 3832 tsnresp.senders_next_tsn = htonl(sender_tsn); 3833 tsnresp.receivers_next_tsn = htonl(receiver_tsn); 3834 3835 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp); 3836 3837 return retval; 3838 } 3839 3840 bool sctp_verify_reconf(const struct sctp_association *asoc, 3841 struct sctp_chunk *chunk, 3842 struct sctp_paramhdr **errp) 3843 { 3844 struct sctp_reconf_chunk *hdr; 3845 union sctp_params param; 3846 __be16 last = 0; 3847 __u16 cnt = 0; 3848 3849 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; 3850 sctp_walk_params(param, hdr, params) { 3851 __u16 length = ntohs(param.p->length); 3852 3853 *errp = param.p; 3854 if (cnt++ > 2) 3855 return false; 3856 switch (param.p->type) { 3857 case SCTP_PARAM_RESET_OUT_REQUEST: 3858 if (length < sizeof(struct sctp_strreset_outreq) || 3859 (last && last != SCTP_PARAM_RESET_RESPONSE && 3860 last != SCTP_PARAM_RESET_IN_REQUEST)) 3861 return false; 3862 break; 3863 case SCTP_PARAM_RESET_IN_REQUEST: 3864 if (length < sizeof(struct sctp_strreset_inreq) || 3865 (last && last != SCTP_PARAM_RESET_OUT_REQUEST)) 3866 return false; 3867 break; 3868 case SCTP_PARAM_RESET_RESPONSE: 3869 if ((length != sizeof(struct sctp_strreset_resp) && 3870 length != sizeof(struct sctp_strreset_resptsn)) || 3871 (last && last != SCTP_PARAM_RESET_RESPONSE && 3872 last != SCTP_PARAM_RESET_OUT_REQUEST)) 3873 return false; 3874 break; 3875 case SCTP_PARAM_RESET_TSN_REQUEST: 3876 if (length != 3877 sizeof(struct sctp_strreset_tsnreq) || last) 3878 return false; 3879 break; 3880 case SCTP_PARAM_RESET_ADD_IN_STREAMS: 3881 if (length != sizeof(struct sctp_strreset_addstrm) || 3882 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS)) 3883 return false; 3884 break; 3885 case SCTP_PARAM_RESET_ADD_OUT_STREAMS: 3886 if (length != sizeof(struct sctp_strreset_addstrm) || 3887 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS)) 3888 return false; 3889 break; 3890 default: 3891 return false; 3892 } 3893 3894 last = param.p->type; 3895 } 3896 3897 return true; 3898 } 3899