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 */ sctp_control_release_owner(struct sk_buff * skb)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 sctp_control_set_owner_w(struct sctp_chunk * chunk)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? */ sctp_chunk_iif(const struct sctp_chunk * 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 */ sctp_init_cause(struct sctp_chunk * chunk,__be16 cause_code,size_t paylen)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 */ sctp_make_init(const struct sctp_association * asoc,const struct sctp_bind_addr * bp,gfp_t gfp,int vparam_len)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 sctp_make_init_ack(const struct sctp_association * asoc,const struct sctp_chunk * chunk,gfp_t gfp,int unkparam_len)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 */ sctp_make_cookie_echo(const struct sctp_association * asoc,const struct sctp_chunk * chunk)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 */ sctp_make_cookie_ack(const struct sctp_association * asoc,const struct sctp_chunk * chunk)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 */ sctp_make_cwr(const struct sctp_association * asoc,const __u32 lowest_tsn,const struct sctp_chunk * chunk)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. */ sctp_make_ecne(const struct sctp_association * asoc,const __u32 lowest_tsn)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 */ sctp_make_datafrag_empty(const struct sctp_association * asoc,const struct sctp_sndrcvinfo * sinfo,int len,__u8 flags,gfp_t gfp)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 */ sctp_make_sack(struct sctp_association * asoc)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. */ sctp_make_shutdown(const struct sctp_association * asoc,const struct sctp_chunk * 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 sctp_make_shutdown_ack(const struct sctp_association * asoc,const struct sctp_chunk * chunk)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 sctp_make_shutdown_complete(const struct sctp_association * asoc,const struct sctp_chunk * chunk)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 */ sctp_make_abort(const struct sctp_association * asoc,const struct sctp_chunk * chunk,const size_t hint)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. */ sctp_make_abort_no_data(const struct sctp_association * asoc,const struct sctp_chunk * chunk,__u32 tsn)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. */ sctp_make_abort_user(const struct sctp_association * asoc,struct msghdr * msg,size_t paylen)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 */ sctp_addto_param(struct sctp_chunk * chunk,int len,const void * data)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. */ sctp_make_abort_violation(const struct sctp_association * asoc,const struct sctp_chunk * chunk,const __u8 * payload,const size_t paylen)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 sctp_make_violation_paramlen(const struct sctp_association * asoc,const struct sctp_chunk * chunk,struct sctp_paramhdr * param)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 sctp_make_violation_max_retrans(const struct sctp_association * asoc,const struct sctp_chunk * chunk)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 sctp_make_new_encap_port(const struct sctp_association * asoc,const struct sctp_chunk * chunk)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. */ sctp_make_heartbeat(const struct sctp_association * asoc,const struct sctp_transport * transport,__u32 probe_size)1162 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1163 const struct sctp_transport *transport, 1164 __u32 probe_size) 1165 { 1166 struct sctp_sender_hb_info hbinfo = {}; 1167 struct sctp_chunk *retval; 1168 1169 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, 1170 sizeof(hbinfo), GFP_ATOMIC); 1171 1172 if (!retval) 1173 goto nodata; 1174 1175 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; 1176 hbinfo.param_hdr.length = htons(sizeof(hbinfo)); 1177 hbinfo.daddr = transport->ipaddr; 1178 hbinfo.sent_at = jiffies; 1179 hbinfo.hb_nonce = transport->hb_nonce; 1180 hbinfo.probe_size = probe_size; 1181 1182 /* Cast away the 'const', as this is just telling the chunk 1183 * what transport it belongs to. 1184 */ 1185 retval->transport = (struct sctp_transport *) transport; 1186 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo), 1187 &hbinfo); 1188 retval->pmtu_probe = !!probe_size; 1189 1190 nodata: 1191 return retval; 1192 } 1193 sctp_make_heartbeat_ack(const struct sctp_association * asoc,const struct sctp_chunk * chunk,const void * payload,const size_t paylen)1194 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1195 const struct sctp_chunk *chunk, 1196 const void *payload, 1197 const size_t paylen) 1198 { 1199 struct sctp_chunk *retval; 1200 1201 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen, 1202 GFP_ATOMIC); 1203 if (!retval) 1204 goto nodata; 1205 1206 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1207 1208 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1209 * 1210 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1211 * HEARTBEAT ACK, * etc.) to the same destination transport 1212 * address from which it * received the DATA or control chunk 1213 * to which it is replying. 1214 * 1215 * [HBACK back to where the HEARTBEAT came from.] 1216 */ 1217 if (chunk) 1218 retval->transport = chunk->transport; 1219 1220 nodata: 1221 return retval; 1222 } 1223 1224 /* RFC4820 3. Padding Chunk (PAD) 1225 * 0 1 2 3 1226 * 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 1227 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1228 * | Type = 0x84 | Flags=0 | Length | 1229 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1230 * | | 1231 * \ Padding Data / 1232 * / \ 1233 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1234 */ sctp_make_pad(const struct sctp_association * asoc,int len)1235 struct sctp_chunk *sctp_make_pad(const struct sctp_association *asoc, int len) 1236 { 1237 struct sctp_chunk *retval; 1238 1239 retval = sctp_make_control(asoc, SCTP_CID_PAD, 0, len, GFP_ATOMIC); 1240 if (!retval) 1241 return NULL; 1242 1243 skb_put_zero(retval->skb, len); 1244 retval->chunk_hdr->length = htons(ntohs(retval->chunk_hdr->length) + len); 1245 retval->chunk_end = skb_tail_pointer(retval->skb); 1246 1247 return retval; 1248 } 1249 1250 /* Create an Operation Error chunk with the specified space reserved. 1251 * This routine can be used for containing multiple causes in the chunk. 1252 */ sctp_make_op_error_space(const struct sctp_association * asoc,const struct sctp_chunk * chunk,size_t size)1253 static struct sctp_chunk *sctp_make_op_error_space( 1254 const struct sctp_association *asoc, 1255 const struct sctp_chunk *chunk, 1256 size_t size) 1257 { 1258 struct sctp_chunk *retval; 1259 1260 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0, 1261 sizeof(struct sctp_errhdr) + size, 1262 GFP_ATOMIC); 1263 if (!retval) 1264 goto nodata; 1265 1266 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1267 * 1268 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1269 * HEARTBEAT ACK, etc.) to the same destination transport 1270 * address from which it received the DATA or control chunk 1271 * to which it is replying. 1272 * 1273 */ 1274 if (chunk) 1275 retval->transport = chunk->transport; 1276 1277 nodata: 1278 return retval; 1279 } 1280 1281 /* Create an Operation Error chunk of a fixed size, specifically, 1282 * min(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) - overheads. 1283 * This is a helper function to allocate an error chunk for those 1284 * invalid parameter codes in which we may not want to report all the 1285 * errors, if the incoming chunk is large. If it can't fit in a single 1286 * packet, we ignore it. 1287 */ sctp_make_op_error_limited(const struct sctp_association * asoc,const struct sctp_chunk * chunk)1288 static inline struct sctp_chunk *sctp_make_op_error_limited( 1289 const struct sctp_association *asoc, 1290 const struct sctp_chunk *chunk) 1291 { 1292 size_t size = SCTP_DEFAULT_MAXSEGMENT; 1293 struct sctp_sock *sp = NULL; 1294 1295 if (asoc) { 1296 size = min_t(size_t, size, asoc->pathmtu); 1297 sp = sctp_sk(asoc->base.sk); 1298 } 1299 1300 size = sctp_mtu_payload(sp, size, sizeof(struct sctp_errhdr)); 1301 1302 return sctp_make_op_error_space(asoc, chunk, size); 1303 } 1304 1305 /* Create an Operation Error chunk. */ sctp_make_op_error(const struct sctp_association * asoc,const struct sctp_chunk * chunk,__be16 cause_code,const void * payload,size_t paylen,size_t reserve_tail)1306 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1307 const struct sctp_chunk *chunk, 1308 __be16 cause_code, const void *payload, 1309 size_t paylen, size_t reserve_tail) 1310 { 1311 struct sctp_chunk *retval; 1312 1313 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); 1314 if (!retval) 1315 goto nodata; 1316 1317 sctp_init_cause(retval, cause_code, paylen + reserve_tail); 1318 sctp_addto_chunk(retval, paylen, payload); 1319 if (reserve_tail) 1320 sctp_addto_param(retval, reserve_tail, NULL); 1321 1322 nodata: 1323 return retval; 1324 } 1325 sctp_make_auth(const struct sctp_association * asoc,__u16 key_id)1326 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc, 1327 __u16 key_id) 1328 { 1329 struct sctp_authhdr auth_hdr; 1330 struct sctp_hmac *hmac_desc; 1331 struct sctp_chunk *retval; 1332 1333 /* Get the first hmac that the peer told us to use */ 1334 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1335 if (unlikely(!hmac_desc)) 1336 return NULL; 1337 1338 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0, 1339 hmac_desc->hmac_len + sizeof(auth_hdr), 1340 GFP_ATOMIC); 1341 if (!retval) 1342 return NULL; 1343 1344 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1345 auth_hdr.shkey_id = htons(key_id); 1346 1347 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr), 1348 &auth_hdr); 1349 1350 skb_put_zero(retval->skb, hmac_desc->hmac_len); 1351 1352 /* Adjust the chunk header to include the empty MAC */ 1353 retval->chunk_hdr->length = 1354 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1355 retval->chunk_end = skb_tail_pointer(retval->skb); 1356 1357 return retval; 1358 } 1359 1360 1361 /******************************************************************** 1362 * 2nd Level Abstractions 1363 ********************************************************************/ 1364 1365 /* Turn an skb into a chunk. 1366 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1367 * 1368 * sctpimpguide-05.txt Section 2.8.2 1369 * M1) Each time a new DATA chunk is transmitted 1370 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1371 * 'TSN.Missing.Report' count will be used to determine missing chunks 1372 * and when to fast retransmit. 1373 * 1374 */ sctp_chunkify(struct sk_buff * skb,const struct sctp_association * asoc,struct sock * sk,gfp_t gfp)1375 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1376 const struct sctp_association *asoc, 1377 struct sock *sk, gfp_t gfp) 1378 { 1379 struct sctp_chunk *retval; 1380 1381 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp); 1382 1383 if (!retval) 1384 goto nodata; 1385 if (!sk) 1386 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb); 1387 1388 INIT_LIST_HEAD(&retval->list); 1389 retval->skb = skb; 1390 retval->asoc = (struct sctp_association *)asoc; 1391 retval->singleton = 1; 1392 1393 retval->fast_retransmit = SCTP_CAN_FRTX; 1394 1395 /* Polish the bead hole. */ 1396 INIT_LIST_HEAD(&retval->transmitted_list); 1397 INIT_LIST_HEAD(&retval->frag_list); 1398 SCTP_DBG_OBJCNT_INC(chunk); 1399 refcount_set(&retval->refcnt, 1); 1400 1401 nodata: 1402 return retval; 1403 } 1404 1405 /* Set chunk->source and dest based on the IP header in chunk->skb. */ sctp_init_addrs(struct sctp_chunk * chunk,union sctp_addr * src,union sctp_addr * dest)1406 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1407 union sctp_addr *dest) 1408 { 1409 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1410 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1411 } 1412 1413 /* Extract the source address from a chunk. */ sctp_source(const struct sctp_chunk * chunk)1414 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1415 { 1416 /* If we have a known transport, use that. */ 1417 if (chunk->transport) { 1418 return &chunk->transport->ipaddr; 1419 } else { 1420 /* Otherwise, extract it from the IP header. */ 1421 return &chunk->source; 1422 } 1423 } 1424 1425 /* Create a new chunk, setting the type and flags headers from the 1426 * arguments, reserving enough space for a 'paylen' byte payload. 1427 */ _sctp_make_chunk(const struct sctp_association * asoc,__u8 type,__u8 flags,int paylen,gfp_t gfp)1428 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 1429 __u8 type, __u8 flags, int paylen, 1430 gfp_t gfp) 1431 { 1432 struct sctp_chunkhdr *chunk_hdr; 1433 struct sctp_chunk *retval; 1434 struct sk_buff *skb; 1435 struct sock *sk; 1436 int chunklen; 1437 1438 chunklen = SCTP_PAD4(sizeof(*chunk_hdr) + paylen); 1439 if (chunklen > SCTP_MAX_CHUNK_LEN) 1440 goto nodata; 1441 1442 /* No need to allocate LL here, as this is only a chunk. */ 1443 skb = alloc_skb(chunklen, gfp); 1444 if (!skb) 1445 goto nodata; 1446 1447 /* Make room for the chunk header. */ 1448 chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr)); 1449 chunk_hdr->type = type; 1450 chunk_hdr->flags = flags; 1451 chunk_hdr->length = htons(sizeof(*chunk_hdr)); 1452 1453 sk = asoc ? asoc->base.sk : NULL; 1454 retval = sctp_chunkify(skb, asoc, sk, gfp); 1455 if (!retval) { 1456 kfree_skb(skb); 1457 goto nodata; 1458 } 1459 1460 retval->chunk_hdr = chunk_hdr; 1461 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr); 1462 1463 /* Determine if the chunk needs to be authenticated */ 1464 if (sctp_auth_send_cid(type, asoc)) 1465 retval->auth = 1; 1466 1467 return retval; 1468 nodata: 1469 return NULL; 1470 } 1471 sctp_make_data(const struct sctp_association * asoc,__u8 flags,int paylen,gfp_t gfp)1472 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 1473 __u8 flags, int paylen, gfp_t gfp) 1474 { 1475 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp); 1476 } 1477 sctp_make_idata(const struct sctp_association * asoc,__u8 flags,int paylen,gfp_t gfp)1478 struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc, 1479 __u8 flags, int paylen, gfp_t gfp) 1480 { 1481 return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp); 1482 } 1483 sctp_make_control(const struct sctp_association * asoc,__u8 type,__u8 flags,int paylen,gfp_t gfp)1484 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 1485 __u8 type, __u8 flags, int paylen, 1486 gfp_t gfp) 1487 { 1488 struct sctp_chunk *chunk; 1489 1490 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp); 1491 if (chunk) 1492 sctp_control_set_owner_w(chunk); 1493 1494 return chunk; 1495 } 1496 1497 /* Release the memory occupied by a chunk. */ sctp_chunk_destroy(struct sctp_chunk * chunk)1498 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1499 { 1500 BUG_ON(!list_empty(&chunk->list)); 1501 list_del_init(&chunk->transmitted_list); 1502 1503 consume_skb(chunk->skb); 1504 consume_skb(chunk->auth_chunk); 1505 1506 SCTP_DBG_OBJCNT_DEC(chunk); 1507 kmem_cache_free(sctp_chunk_cachep, chunk); 1508 } 1509 1510 /* Possibly, free the chunk. */ sctp_chunk_free(struct sctp_chunk * chunk)1511 void sctp_chunk_free(struct sctp_chunk *chunk) 1512 { 1513 /* Release our reference on the message tracker. */ 1514 if (chunk->msg) 1515 sctp_datamsg_put(chunk->msg); 1516 1517 sctp_chunk_put(chunk); 1518 } 1519 1520 /* Grab a reference to the chunk. */ sctp_chunk_hold(struct sctp_chunk * ch)1521 void sctp_chunk_hold(struct sctp_chunk *ch) 1522 { 1523 refcount_inc(&ch->refcnt); 1524 } 1525 1526 /* Release a reference to the chunk. */ sctp_chunk_put(struct sctp_chunk * ch)1527 void sctp_chunk_put(struct sctp_chunk *ch) 1528 { 1529 if (refcount_dec_and_test(&ch->refcnt)) 1530 sctp_chunk_destroy(ch); 1531 } 1532 1533 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1534 * enough. 1535 */ sctp_addto_chunk(struct sctp_chunk * chunk,int len,const void * data)1536 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1537 { 1538 int chunklen = ntohs(chunk->chunk_hdr->length); 1539 int padlen = SCTP_PAD4(chunklen) - chunklen; 1540 void *target; 1541 1542 skb_put_zero(chunk->skb, padlen); 1543 target = skb_put_data(chunk->skb, data, len); 1544 1545 /* Adjust the chunk length field. */ 1546 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1547 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1548 1549 return target; 1550 } 1551 1552 /* Append bytes from user space to the end of a chunk. Will panic if 1553 * chunk is not big enough. 1554 * Returns a kernel err value. 1555 */ sctp_user_addto_chunk(struct sctp_chunk * chunk,int len,struct iov_iter * from)1556 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len, 1557 struct iov_iter *from) 1558 { 1559 void *target; 1560 1561 /* Make room in chunk for data. */ 1562 target = skb_put(chunk->skb, len); 1563 1564 /* Copy data (whole iovec) into chunk */ 1565 if (!copy_from_iter_full(target, len, from)) 1566 return -EFAULT; 1567 1568 /* Adjust the chunk length field. */ 1569 chunk->chunk_hdr->length = 1570 htons(ntohs(chunk->chunk_hdr->length) + len); 1571 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1572 1573 return 0; 1574 } 1575 1576 /* Helper function to assign a TSN if needed. This assumes that both 1577 * the data_hdr and association have already been assigned. 1578 */ sctp_chunk_assign_ssn(struct sctp_chunk * chunk)1579 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1580 { 1581 struct sctp_stream *stream; 1582 struct sctp_chunk *lchunk; 1583 struct sctp_datamsg *msg; 1584 __u16 ssn, sid; 1585 1586 if (chunk->has_ssn) 1587 return; 1588 1589 /* All fragments will be on the same stream */ 1590 sid = ntohs(chunk->subh.data_hdr->stream); 1591 stream = &chunk->asoc->stream; 1592 1593 /* Now assign the sequence number to the entire message. 1594 * All fragments must have the same stream sequence number. 1595 */ 1596 msg = chunk->msg; 1597 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1598 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1599 ssn = 0; 1600 } else { 1601 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1602 ssn = sctp_ssn_next(stream, out, sid); 1603 else 1604 ssn = sctp_ssn_peek(stream, out, sid); 1605 } 1606 1607 lchunk->subh.data_hdr->ssn = htons(ssn); 1608 lchunk->has_ssn = 1; 1609 } 1610 } 1611 1612 /* Helper function to assign a TSN if needed. This assumes that both 1613 * the data_hdr and association have already been assigned. 1614 */ sctp_chunk_assign_tsn(struct sctp_chunk * chunk)1615 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1616 { 1617 if (!chunk->has_tsn) { 1618 /* This is the last possible instant to 1619 * assign a TSN. 1620 */ 1621 chunk->subh.data_hdr->tsn = 1622 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1623 chunk->has_tsn = 1; 1624 } 1625 } 1626 1627 /* Create a CLOSED association to use with an incoming packet. */ sctp_make_temp_asoc(const struct sctp_endpoint * ep,struct sctp_chunk * chunk,gfp_t gfp)1628 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1629 struct sctp_chunk *chunk, 1630 gfp_t gfp) 1631 { 1632 struct sctp_association *asoc; 1633 enum sctp_scope scope; 1634 struct sk_buff *skb; 1635 1636 /* Create the bare association. */ 1637 scope = sctp_scope(sctp_source(chunk)); 1638 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1639 if (!asoc) 1640 goto nodata; 1641 asoc->temp = 1; 1642 skb = chunk->skb; 1643 /* Create an entry for the source address of the packet. */ 1644 SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1); 1645 1646 nodata: 1647 return asoc; 1648 } 1649 1650 /* Build a cookie representing asoc. 1651 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1652 */ sctp_pack_cookie(const struct sctp_endpoint * ep,const struct sctp_association * asoc,const struct sctp_chunk * init_chunk,int * cookie_len,const __u8 * raw_addrs,int addrs_len)1653 static struct sctp_cookie_param *sctp_pack_cookie( 1654 const struct sctp_endpoint *ep, 1655 const struct sctp_association *asoc, 1656 const struct sctp_chunk *init_chunk, 1657 int *cookie_len, const __u8 *raw_addrs, 1658 int addrs_len) 1659 { 1660 struct sctp_signed_cookie *cookie; 1661 struct sctp_cookie_param *retval; 1662 int headersize, bodysize; 1663 1664 /* Header size is static data prior to the actual cookie, including 1665 * any padding. 1666 */ 1667 headersize = sizeof(struct sctp_paramhdr) + 1668 (sizeof(struct sctp_signed_cookie) - 1669 sizeof(struct sctp_cookie)); 1670 bodysize = sizeof(struct sctp_cookie) 1671 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1672 1673 /* Pad out the cookie to a multiple to make the signature 1674 * functions simpler to write. 1675 */ 1676 if (bodysize % SCTP_COOKIE_MULTIPLE) 1677 bodysize += SCTP_COOKIE_MULTIPLE 1678 - (bodysize % SCTP_COOKIE_MULTIPLE); 1679 *cookie_len = headersize + bodysize; 1680 1681 /* Clear this memory since we are sending this data structure 1682 * out on the network. 1683 */ 1684 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1685 if (!retval) 1686 goto nodata; 1687 1688 cookie = (struct sctp_signed_cookie *) retval->body; 1689 1690 /* Set up the parameter header. */ 1691 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1692 retval->p.length = htons(*cookie_len); 1693 1694 /* Copy the cookie part of the association itself. */ 1695 cookie->c = asoc->c; 1696 /* Save the raw address list length in the cookie. */ 1697 cookie->c.raw_addr_list_len = addrs_len; 1698 1699 /* Remember PR-SCTP capability. */ 1700 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1701 1702 /* Save adaptation indication in the cookie. */ 1703 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1704 1705 /* Set an expiration time for the cookie. */ 1706 cookie->c.expiration = ktime_add(asoc->cookie_life, 1707 ktime_get_real()); 1708 1709 /* Copy the peer's init packet. */ 1710 memcpy(cookie + 1, init_chunk->chunk_hdr, 1711 ntohs(init_chunk->chunk_hdr->length)); 1712 1713 /* Copy the raw local address list of the association. */ 1714 memcpy((__u8 *)(cookie + 1) + 1715 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1716 1717 if (sctp_sk(ep->base.sk)->hmac) { 1718 struct crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac; 1719 int err; 1720 1721 /* Sign the message. */ 1722 err = crypto_shash_setkey(tfm, ep->secret_key, 1723 sizeof(ep->secret_key)) ?: 1724 crypto_shash_tfm_digest(tfm, (u8 *)&cookie->c, bodysize, 1725 cookie->signature); 1726 if (err) 1727 goto free_cookie; 1728 } 1729 1730 return retval; 1731 1732 free_cookie: 1733 kfree(retval); 1734 nodata: 1735 *cookie_len = 0; 1736 return NULL; 1737 } 1738 1739 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ sctp_unpack_cookie(const struct sctp_endpoint * ep,const struct sctp_association * asoc,struct sctp_chunk * chunk,gfp_t gfp,int * error,struct sctp_chunk ** errp)1740 struct sctp_association *sctp_unpack_cookie( 1741 const struct sctp_endpoint *ep, 1742 const struct sctp_association *asoc, 1743 struct sctp_chunk *chunk, gfp_t gfp, 1744 int *error, struct sctp_chunk **errp) 1745 { 1746 struct sctp_association *retval = NULL; 1747 int headersize, bodysize, fixed_size; 1748 struct sctp_signed_cookie *cookie; 1749 struct sk_buff *skb = chunk->skb; 1750 struct sctp_cookie *bear_cookie; 1751 __u8 *digest = ep->digest; 1752 enum sctp_scope scope; 1753 unsigned int len; 1754 ktime_t kt; 1755 1756 /* Header size is static data prior to the actual cookie, including 1757 * any padding. 1758 */ 1759 headersize = sizeof(struct sctp_chunkhdr) + 1760 (sizeof(struct sctp_signed_cookie) - 1761 sizeof(struct sctp_cookie)); 1762 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1763 fixed_size = headersize + sizeof(struct sctp_cookie); 1764 1765 /* Verify that the chunk looks like it even has a cookie. 1766 * There must be enough room for our cookie and our peer's 1767 * INIT chunk. 1768 */ 1769 len = ntohs(chunk->chunk_hdr->length); 1770 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1771 goto malformed; 1772 1773 /* Verify that the cookie has been padded out. */ 1774 if (bodysize % SCTP_COOKIE_MULTIPLE) 1775 goto malformed; 1776 1777 /* Process the cookie. */ 1778 cookie = chunk->subh.cookie_hdr; 1779 bear_cookie = &cookie->c; 1780 1781 if (!sctp_sk(ep->base.sk)->hmac) 1782 goto no_hmac; 1783 1784 /* Check the signature. */ 1785 { 1786 struct crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac; 1787 int err; 1788 1789 err = crypto_shash_setkey(tfm, ep->secret_key, 1790 sizeof(ep->secret_key)) ?: 1791 crypto_shash_tfm_digest(tfm, (u8 *)bear_cookie, bodysize, 1792 digest); 1793 if (err) { 1794 *error = -SCTP_IERROR_NOMEM; 1795 goto fail; 1796 } 1797 } 1798 1799 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1800 *error = -SCTP_IERROR_BAD_SIG; 1801 goto fail; 1802 } 1803 1804 no_hmac: 1805 /* IG Section 2.35.2: 1806 * 3) Compare the port numbers and the verification tag contained 1807 * within the COOKIE ECHO chunk to the actual port numbers and the 1808 * verification tag within the SCTP common header of the received 1809 * packet. If these values do not match the packet MUST be silently 1810 * discarded, 1811 */ 1812 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1813 *error = -SCTP_IERROR_BAD_TAG; 1814 goto fail; 1815 } 1816 1817 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1818 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1819 *error = -SCTP_IERROR_BAD_PORTS; 1820 goto fail; 1821 } 1822 1823 /* Check to see if the cookie is stale. If there is already 1824 * an association, there is no need to check cookie's expiration 1825 * for init collision case of lost COOKIE ACK. 1826 * If skb has been timestamped, then use the stamp, otherwise 1827 * use current time. This introduces a small possibility that 1828 * a cookie may be considered expired, but this would only slow 1829 * down the new association establishment instead of every packet. 1830 */ 1831 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1832 kt = skb_get_ktime(skb); 1833 else 1834 kt = ktime_get_real(); 1835 1836 if (!asoc && ktime_before(bear_cookie->expiration, kt)) { 1837 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); 1838 __be32 n = htonl(usecs); 1839 1840 /* 1841 * Section 3.3.10.3 Stale Cookie Error (3) 1842 * 1843 * Cause of error 1844 * --------------- 1845 * Stale Cookie Error: Indicates the receipt of a valid State 1846 * Cookie that has expired. 1847 */ 1848 *errp = sctp_make_op_error(asoc, chunk, 1849 SCTP_ERROR_STALE_COOKIE, &n, 1850 sizeof(n), 0); 1851 if (*errp) 1852 *error = -SCTP_IERROR_STALE_COOKIE; 1853 else 1854 *error = -SCTP_IERROR_NOMEM; 1855 1856 goto fail; 1857 } 1858 1859 /* Make a new base association. */ 1860 scope = sctp_scope(sctp_source(chunk)); 1861 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1862 if (!retval) { 1863 *error = -SCTP_IERROR_NOMEM; 1864 goto fail; 1865 } 1866 1867 /* Set up our peer's port number. */ 1868 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1869 1870 /* Populate the association from the cookie. */ 1871 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1872 1873 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1874 GFP_ATOMIC) < 0) { 1875 *error = -SCTP_IERROR_NOMEM; 1876 goto fail; 1877 } 1878 1879 /* Also, add the destination address. */ 1880 if (list_empty(&retval->base.bind_addr.address_list)) { 1881 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1882 sizeof(chunk->dest), SCTP_ADDR_SRC, 1883 GFP_ATOMIC); 1884 } 1885 1886 retval->next_tsn = retval->c.initial_tsn; 1887 retval->ctsn_ack_point = retval->next_tsn - 1; 1888 retval->addip_serial = retval->c.initial_tsn; 1889 retval->strreset_outseq = retval->c.initial_tsn; 1890 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1891 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1892 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1893 1894 /* The INIT stuff will be done by the side effects. */ 1895 return retval; 1896 1897 fail: 1898 if (retval) 1899 sctp_association_free(retval); 1900 1901 return NULL; 1902 1903 malformed: 1904 /* Yikes! The packet is either corrupt or deliberately 1905 * malformed. 1906 */ 1907 *error = -SCTP_IERROR_MALFORMED; 1908 goto fail; 1909 } 1910 1911 /******************************************************************** 1912 * 3rd Level Abstractions 1913 ********************************************************************/ 1914 1915 struct __sctp_missing { 1916 __be32 num_missing; 1917 __be16 type; 1918 } __packed; 1919 1920 /* 1921 * Report a missing mandatory parameter. 1922 */ sctp_process_missing_param(const struct sctp_association * asoc,enum sctp_param paramtype,struct sctp_chunk * chunk,struct sctp_chunk ** errp)1923 static int sctp_process_missing_param(const struct sctp_association *asoc, 1924 enum sctp_param paramtype, 1925 struct sctp_chunk *chunk, 1926 struct sctp_chunk **errp) 1927 { 1928 struct __sctp_missing report; 1929 __u16 len; 1930 1931 len = SCTP_PAD4(sizeof(report)); 1932 1933 /* Make an ERROR chunk, preparing enough room for 1934 * returning multiple unknown parameters. 1935 */ 1936 if (!*errp) 1937 *errp = sctp_make_op_error_space(asoc, chunk, len); 1938 1939 if (*errp) { 1940 report.num_missing = htonl(1); 1941 report.type = paramtype; 1942 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1943 sizeof(report)); 1944 sctp_addto_chunk(*errp, sizeof(report), &report); 1945 } 1946 1947 /* Stop processing this chunk. */ 1948 return 0; 1949 } 1950 1951 /* Report an Invalid Mandatory Parameter. */ sctp_process_inv_mandatory(const struct sctp_association * asoc,struct sctp_chunk * chunk,struct sctp_chunk ** errp)1952 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1953 struct sctp_chunk *chunk, 1954 struct sctp_chunk **errp) 1955 { 1956 /* Invalid Mandatory Parameter Error has no payload. */ 1957 1958 if (!*errp) 1959 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1960 1961 if (*errp) 1962 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1963 1964 /* Stop processing this chunk. */ 1965 return 0; 1966 } 1967 sctp_process_inv_paramlength(const struct sctp_association * asoc,struct sctp_paramhdr * param,const struct sctp_chunk * chunk,struct sctp_chunk ** errp)1968 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1969 struct sctp_paramhdr *param, 1970 const struct sctp_chunk *chunk, 1971 struct sctp_chunk **errp) 1972 { 1973 /* This is a fatal error. Any accumulated non-fatal errors are 1974 * not reported. 1975 */ 1976 if (*errp) 1977 sctp_chunk_free(*errp); 1978 1979 /* Create an error chunk and fill it in with our payload. */ 1980 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1981 1982 return 0; 1983 } 1984 1985 1986 /* Do not attempt to handle the HOST_NAME parm. However, do 1987 * send back an indicator to the peer. 1988 */ sctp_process_hn_param(const struct sctp_association * asoc,union sctp_params param,struct sctp_chunk * chunk,struct sctp_chunk ** errp)1989 static int sctp_process_hn_param(const struct sctp_association *asoc, 1990 union sctp_params param, 1991 struct sctp_chunk *chunk, 1992 struct sctp_chunk **errp) 1993 { 1994 __u16 len = ntohs(param.p->length); 1995 1996 /* Processing of the HOST_NAME parameter will generate an 1997 * ABORT. If we've accumulated any non-fatal errors, they 1998 * would be unrecognized parameters and we should not include 1999 * them in the ABORT. 2000 */ 2001 if (*errp) 2002 sctp_chunk_free(*errp); 2003 2004 *errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_DNS_FAILED, 2005 param.v, len, 0); 2006 2007 /* Stop processing this chunk. */ 2008 return 0; 2009 } 2010 sctp_verify_ext_param(struct net * net,const struct sctp_endpoint * ep,union sctp_params param)2011 static int sctp_verify_ext_param(struct net *net, 2012 const struct sctp_endpoint *ep, 2013 union sctp_params param) 2014 { 2015 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2016 int have_asconf = 0; 2017 int have_auth = 0; 2018 int i; 2019 2020 for (i = 0; i < num_ext; i++) { 2021 switch (param.ext->chunks[i]) { 2022 case SCTP_CID_AUTH: 2023 have_auth = 1; 2024 break; 2025 case SCTP_CID_ASCONF: 2026 case SCTP_CID_ASCONF_ACK: 2027 have_asconf = 1; 2028 break; 2029 } 2030 } 2031 2032 /* ADD-IP Security: The draft requires us to ABORT or ignore the 2033 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 2034 * only if ADD-IP is turned on and we are not backward-compatible 2035 * mode. 2036 */ 2037 if (net->sctp.addip_noauth) 2038 return 1; 2039 2040 if (ep->asconf_enable && !have_auth && have_asconf) 2041 return 0; 2042 2043 return 1; 2044 } 2045 sctp_process_ext_param(struct sctp_association * asoc,union sctp_params param)2046 static void sctp_process_ext_param(struct sctp_association *asoc, 2047 union sctp_params param) 2048 { 2049 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2050 int i; 2051 2052 for (i = 0; i < num_ext; i++) { 2053 switch (param.ext->chunks[i]) { 2054 case SCTP_CID_RECONF: 2055 if (asoc->ep->reconf_enable) 2056 asoc->peer.reconf_capable = 1; 2057 break; 2058 case SCTP_CID_FWD_TSN: 2059 if (asoc->ep->prsctp_enable) 2060 asoc->peer.prsctp_capable = 1; 2061 break; 2062 case SCTP_CID_AUTH: 2063 /* if the peer reports AUTH, assume that he 2064 * supports AUTH. 2065 */ 2066 if (asoc->ep->auth_enable) 2067 asoc->peer.auth_capable = 1; 2068 break; 2069 case SCTP_CID_ASCONF: 2070 case SCTP_CID_ASCONF_ACK: 2071 if (asoc->ep->asconf_enable) 2072 asoc->peer.asconf_capable = 1; 2073 break; 2074 case SCTP_CID_I_DATA: 2075 if (asoc->ep->intl_enable) 2076 asoc->peer.intl_capable = 1; 2077 break; 2078 default: 2079 break; 2080 } 2081 } 2082 } 2083 2084 /* RFC 3.2.1 & the Implementers Guide 2.2. 2085 * 2086 * The Parameter Types are encoded such that the 2087 * highest-order two bits specify the action that must be 2088 * taken if the processing endpoint does not recognize the 2089 * Parameter Type. 2090 * 2091 * 00 - Stop processing this parameter; do not process any further 2092 * parameters within this chunk 2093 * 2094 * 01 - Stop processing this parameter, do not process any further 2095 * parameters within this chunk, and report the unrecognized 2096 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2097 * 2098 * 10 - Skip this parameter and continue processing. 2099 * 2100 * 11 - Skip this parameter and continue processing but 2101 * report the unrecognized parameter in an 2102 * 'Unrecognized Parameter' ERROR chunk. 2103 * 2104 * Return value: 2105 * SCTP_IERROR_NO_ERROR - continue with the chunk 2106 * SCTP_IERROR_ERROR - stop and report an error. 2107 * SCTP_IERROR_NOMEME - out of memory. 2108 */ sctp_process_unk_param(const struct sctp_association * asoc,union sctp_params param,struct sctp_chunk * chunk,struct sctp_chunk ** errp)2109 static enum sctp_ierror sctp_process_unk_param( 2110 const struct sctp_association *asoc, 2111 union sctp_params param, 2112 struct sctp_chunk *chunk, 2113 struct sctp_chunk **errp) 2114 { 2115 int retval = SCTP_IERROR_NO_ERROR; 2116 2117 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2118 case SCTP_PARAM_ACTION_DISCARD: 2119 retval = SCTP_IERROR_ERROR; 2120 break; 2121 case SCTP_PARAM_ACTION_SKIP: 2122 break; 2123 case SCTP_PARAM_ACTION_DISCARD_ERR: 2124 retval = SCTP_IERROR_ERROR; 2125 fallthrough; 2126 case SCTP_PARAM_ACTION_SKIP_ERR: 2127 /* Make an ERROR chunk, preparing enough room for 2128 * returning multiple unknown parameters. 2129 */ 2130 if (!*errp) { 2131 *errp = sctp_make_op_error_limited(asoc, chunk); 2132 if (!*errp) { 2133 /* If there is no memory for generating the 2134 * ERROR report as specified, an ABORT will be 2135 * triggered to the peer and the association 2136 * won't be established. 2137 */ 2138 retval = SCTP_IERROR_NOMEM; 2139 break; 2140 } 2141 } 2142 2143 if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2144 ntohs(param.p->length))) 2145 sctp_addto_chunk(*errp, ntohs(param.p->length), 2146 param.v); 2147 break; 2148 default: 2149 break; 2150 } 2151 2152 return retval; 2153 } 2154 2155 /* Verify variable length parameters 2156 * Return values: 2157 * SCTP_IERROR_ABORT - trigger an ABORT 2158 * SCTP_IERROR_NOMEM - out of memory (abort) 2159 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2160 * SCTP_IERROR_NO_ERROR - continue with the chunk 2161 */ sctp_verify_param(struct net * net,const struct sctp_endpoint * ep,const struct sctp_association * asoc,union sctp_params param,enum sctp_cid cid,struct sctp_chunk * chunk,struct sctp_chunk ** err_chunk)2162 static enum sctp_ierror sctp_verify_param(struct net *net, 2163 const struct sctp_endpoint *ep, 2164 const struct sctp_association *asoc, 2165 union sctp_params param, 2166 enum sctp_cid cid, 2167 struct sctp_chunk *chunk, 2168 struct sctp_chunk **err_chunk) 2169 { 2170 struct sctp_hmac_algo_param *hmacs; 2171 int retval = SCTP_IERROR_NO_ERROR; 2172 __u16 n_elt, id = 0; 2173 int i; 2174 2175 /* FIXME - This routine is not looking at each parameter per the 2176 * chunk type, i.e., unrecognized parameters should be further 2177 * identified based on the chunk id. 2178 */ 2179 2180 switch (param.p->type) { 2181 case SCTP_PARAM_IPV4_ADDRESS: 2182 case SCTP_PARAM_IPV6_ADDRESS: 2183 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2184 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2185 case SCTP_PARAM_STATE_COOKIE: 2186 case SCTP_PARAM_HEARTBEAT_INFO: 2187 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2188 case SCTP_PARAM_ECN_CAPABLE: 2189 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2190 break; 2191 2192 case SCTP_PARAM_SUPPORTED_EXT: 2193 if (!sctp_verify_ext_param(net, ep, param)) 2194 return SCTP_IERROR_ABORT; 2195 break; 2196 2197 case SCTP_PARAM_SET_PRIMARY: 2198 if (!ep->asconf_enable) 2199 goto unhandled; 2200 2201 if (ntohs(param.p->length) < sizeof(struct sctp_addip_param) + 2202 sizeof(struct sctp_paramhdr)) { 2203 sctp_process_inv_paramlength(asoc, param.p, 2204 chunk, err_chunk); 2205 retval = SCTP_IERROR_ABORT; 2206 } 2207 break; 2208 2209 case SCTP_PARAM_HOST_NAME_ADDRESS: 2210 /* This param has been Deprecated, send ABORT. */ 2211 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2212 retval = SCTP_IERROR_ABORT; 2213 break; 2214 2215 case SCTP_PARAM_FWD_TSN_SUPPORT: 2216 if (ep->prsctp_enable) 2217 break; 2218 goto unhandled; 2219 2220 case SCTP_PARAM_RANDOM: 2221 if (!ep->auth_enable) 2222 goto unhandled; 2223 2224 /* SCTP-AUTH: Secion 6.1 2225 * If the random number is not 32 byte long the association 2226 * MUST be aborted. The ABORT chunk SHOULD contain the error 2227 * cause 'Protocol Violation'. 2228 */ 2229 if (SCTP_AUTH_RANDOM_LENGTH != ntohs(param.p->length) - 2230 sizeof(struct sctp_paramhdr)) { 2231 sctp_process_inv_paramlength(asoc, param.p, 2232 chunk, err_chunk); 2233 retval = SCTP_IERROR_ABORT; 2234 } 2235 break; 2236 2237 case SCTP_PARAM_CHUNKS: 2238 if (!ep->auth_enable) 2239 goto unhandled; 2240 2241 /* SCTP-AUTH: Section 3.2 2242 * The CHUNKS parameter MUST be included once in the INIT or 2243 * INIT-ACK chunk if the sender wants to receive authenticated 2244 * chunks. Its maximum length is 260 bytes. 2245 */ 2246 if (260 < ntohs(param.p->length)) { 2247 sctp_process_inv_paramlength(asoc, param.p, 2248 chunk, err_chunk); 2249 retval = SCTP_IERROR_ABORT; 2250 } 2251 break; 2252 2253 case SCTP_PARAM_HMAC_ALGO: 2254 if (!ep->auth_enable) 2255 goto unhandled; 2256 2257 hmacs = (struct sctp_hmac_algo_param *)param.p; 2258 n_elt = (ntohs(param.p->length) - 2259 sizeof(struct sctp_paramhdr)) >> 1; 2260 2261 /* SCTP-AUTH: Section 6.1 2262 * The HMAC algorithm based on SHA-1 MUST be supported and 2263 * included in the HMAC-ALGO parameter. 2264 */ 2265 for (i = 0; i < n_elt; i++) { 2266 id = ntohs(hmacs->hmac_ids[i]); 2267 2268 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2269 break; 2270 } 2271 2272 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2273 sctp_process_inv_paramlength(asoc, param.p, chunk, 2274 err_chunk); 2275 retval = SCTP_IERROR_ABORT; 2276 } 2277 break; 2278 unhandled: 2279 default: 2280 pr_debug("%s: unrecognized param:%d for chunk:%d\n", 2281 __func__, ntohs(param.p->type), cid); 2282 2283 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2284 break; 2285 } 2286 return retval; 2287 } 2288 2289 /* Verify the INIT packet before we process it. */ sctp_verify_init(struct net * net,const struct sctp_endpoint * ep,const struct sctp_association * asoc,enum sctp_cid cid,struct sctp_init_chunk * peer_init,struct sctp_chunk * chunk,struct sctp_chunk ** errp)2290 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 2291 const struct sctp_association *asoc, enum sctp_cid cid, 2292 struct sctp_init_chunk *peer_init, 2293 struct sctp_chunk *chunk, struct sctp_chunk **errp) 2294 { 2295 union sctp_params param; 2296 bool has_cookie = false; 2297 int result; 2298 2299 /* Check for missing mandatory parameters. Note: Initial TSN is 2300 * also mandatory, but is not checked here since the valid range 2301 * is 0..2**32-1. RFC4960, section 3.3.3. 2302 */ 2303 if (peer_init->init_hdr.num_outbound_streams == 0 || 2304 peer_init->init_hdr.num_inbound_streams == 0 || 2305 peer_init->init_hdr.init_tag == 0 || 2306 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) 2307 return sctp_process_inv_mandatory(asoc, chunk, errp); 2308 2309 sctp_walk_params(param, peer_init) { 2310 if (param.p->type == SCTP_PARAM_STATE_COOKIE) 2311 has_cookie = true; 2312 } 2313 2314 /* There is a possibility that a parameter length was bad and 2315 * in that case we would have stoped walking the parameters. 2316 * The current param.p would point at the bad one. 2317 * Current consensus on the mailing list is to generate a PROTOCOL 2318 * VIOLATION error. We build the ERROR chunk here and let the normal 2319 * error handling code build and send the packet. 2320 */ 2321 if (param.v != (void *)chunk->chunk_end) 2322 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2323 2324 /* The only missing mandatory param possible today is 2325 * the state cookie for an INIT-ACK chunk. 2326 */ 2327 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2328 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2329 chunk, errp); 2330 2331 /* Verify all the variable length parameters */ 2332 sctp_walk_params(param, peer_init) { 2333 result = sctp_verify_param(net, ep, asoc, param, cid, 2334 chunk, errp); 2335 switch (result) { 2336 case SCTP_IERROR_ABORT: 2337 case SCTP_IERROR_NOMEM: 2338 return 0; 2339 case SCTP_IERROR_ERROR: 2340 return 1; 2341 case SCTP_IERROR_NO_ERROR: 2342 default: 2343 break; 2344 } 2345 2346 } /* for (loop through all parameters) */ 2347 2348 return 1; 2349 } 2350 2351 /* Unpack the parameters in an INIT packet into an association. 2352 * Returns 0 on failure, else success. 2353 * FIXME: This is an association method. 2354 */ sctp_process_init(struct sctp_association * asoc,struct sctp_chunk * chunk,const union sctp_addr * peer_addr,struct sctp_init_chunk * peer_init,gfp_t gfp)2355 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2356 const union sctp_addr *peer_addr, 2357 struct sctp_init_chunk *peer_init, gfp_t gfp) 2358 { 2359 struct sctp_transport *transport; 2360 struct list_head *pos, *temp; 2361 union sctp_params param; 2362 union sctp_addr addr; 2363 struct sctp_af *af; 2364 int src_match = 0; 2365 2366 /* We must include the address that the INIT packet came from. 2367 * This is the only address that matters for an INIT packet. 2368 * When processing a COOKIE ECHO, we retrieve the from address 2369 * of the INIT from the cookie. 2370 */ 2371 2372 /* This implementation defaults to making the first transport 2373 * added as the primary transport. The source address seems to 2374 * be a better choice than any of the embedded addresses. 2375 */ 2376 asoc->encap_port = SCTP_INPUT_CB(chunk->skb)->encap_port; 2377 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2378 goto nomem; 2379 2380 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2381 src_match = 1; 2382 2383 /* Process the initialization parameters. */ 2384 sctp_walk_params(param, peer_init) { 2385 if (!src_match && 2386 (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2387 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2388 af = sctp_get_af_specific(param_type2af(param.p->type)); 2389 if (!af->from_addr_param(&addr, param.addr, 2390 chunk->sctp_hdr->source, 0)) 2391 continue; 2392 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2393 src_match = 1; 2394 } 2395 2396 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2397 goto clean_up; 2398 } 2399 2400 /* source address of chunk may not match any valid address */ 2401 if (!src_match) 2402 goto clean_up; 2403 2404 /* AUTH: After processing the parameters, make sure that we 2405 * have all the required info to potentially do authentications. 2406 */ 2407 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2408 !asoc->peer.peer_hmacs)) 2409 asoc->peer.auth_capable = 0; 2410 2411 /* In a non-backward compatible mode, if the peer claims 2412 * support for ADD-IP but not AUTH, the ADD-IP spec states 2413 * that we MUST ABORT the association. Section 6. The section 2414 * also give us an option to silently ignore the packet, which 2415 * is what we'll do here. 2416 */ 2417 if (!asoc->base.net->sctp.addip_noauth && 2418 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2419 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2420 SCTP_PARAM_DEL_IP | 2421 SCTP_PARAM_SET_PRIMARY); 2422 asoc->peer.asconf_capable = 0; 2423 goto clean_up; 2424 } 2425 2426 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2427 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2428 transport = list_entry(pos, struct sctp_transport, transports); 2429 if (transport->state == SCTP_UNKNOWN) { 2430 sctp_assoc_rm_peer(asoc, transport); 2431 } 2432 } 2433 2434 /* The fixed INIT headers are always in network byte 2435 * order. 2436 */ 2437 asoc->peer.i.init_tag = 2438 ntohl(peer_init->init_hdr.init_tag); 2439 asoc->peer.i.a_rwnd = 2440 ntohl(peer_init->init_hdr.a_rwnd); 2441 asoc->peer.i.num_outbound_streams = 2442 ntohs(peer_init->init_hdr.num_outbound_streams); 2443 asoc->peer.i.num_inbound_streams = 2444 ntohs(peer_init->init_hdr.num_inbound_streams); 2445 asoc->peer.i.initial_tsn = 2446 ntohl(peer_init->init_hdr.initial_tsn); 2447 2448 asoc->strreset_inseq = asoc->peer.i.initial_tsn; 2449 2450 /* Apply the upper bounds for output streams based on peer's 2451 * number of inbound streams. 2452 */ 2453 if (asoc->c.sinit_num_ostreams > 2454 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2455 asoc->c.sinit_num_ostreams = 2456 ntohs(peer_init->init_hdr.num_inbound_streams); 2457 } 2458 2459 if (asoc->c.sinit_max_instreams > 2460 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2461 asoc->c.sinit_max_instreams = 2462 ntohs(peer_init->init_hdr.num_outbound_streams); 2463 } 2464 2465 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2466 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2467 2468 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2469 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2470 2471 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2472 * high (for example, implementations MAY use the size of the receiver 2473 * advertised window). 2474 */ 2475 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2476 transports) { 2477 transport->ssthresh = asoc->peer.i.a_rwnd; 2478 } 2479 2480 /* Set up the TSN tracking pieces. */ 2481 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2482 asoc->peer.i.initial_tsn, gfp)) 2483 goto clean_up; 2484 2485 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2486 * 2487 * The stream sequence number in all the streams shall start 2488 * from 0 when the association is established. Also, when the 2489 * stream sequence number reaches the value 65535 the next 2490 * stream sequence number shall be set to 0. 2491 */ 2492 2493 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams, 2494 asoc->c.sinit_max_instreams, gfp)) 2495 goto clean_up; 2496 2497 /* Update frag_point when stream_interleave may get changed. */ 2498 sctp_assoc_update_frag_point(asoc); 2499 2500 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp)) 2501 goto clean_up; 2502 2503 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2504 * 2505 * When an endpoint has an ASCONF signaled change to be sent to the 2506 * remote endpoint it should do the following: 2507 * ... 2508 * A2) A serial number should be assigned to the Chunk. The serial 2509 * number should be a monotonically increasing number. All serial 2510 * numbers are defined to be initialized at the start of the 2511 * association to the same value as the Initial TSN. 2512 */ 2513 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2514 return 1; 2515 2516 clean_up: 2517 /* Release the transport structures. */ 2518 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2519 transport = list_entry(pos, struct sctp_transport, transports); 2520 if (transport->state != SCTP_ACTIVE) 2521 sctp_assoc_rm_peer(asoc, transport); 2522 } 2523 2524 nomem: 2525 return 0; 2526 } 2527 2528 2529 /* Update asoc with the option described in param. 2530 * 2531 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2532 * 2533 * asoc is the association to update. 2534 * param is the variable length parameter to use for update. 2535 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2536 * If the current packet is an INIT we want to minimize the amount of 2537 * work we do. In particular, we should not build transport 2538 * structures for the addresses. 2539 */ sctp_process_param(struct sctp_association * asoc,union sctp_params param,const union sctp_addr * peer_addr,gfp_t gfp)2540 static int sctp_process_param(struct sctp_association *asoc, 2541 union sctp_params param, 2542 const union sctp_addr *peer_addr, 2543 gfp_t gfp) 2544 { 2545 struct sctp_endpoint *ep = asoc->ep; 2546 union sctp_addr_param *addr_param; 2547 struct net *net = asoc->base.net; 2548 struct sctp_transport *t; 2549 enum sctp_scope scope; 2550 union sctp_addr addr; 2551 struct sctp_af *af; 2552 int retval = 1, i; 2553 u32 stale; 2554 __u16 sat; 2555 2556 /* We maintain all INIT parameters in network byte order all the 2557 * time. This allows us to not worry about whether the parameters 2558 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2559 */ 2560 switch (param.p->type) { 2561 case SCTP_PARAM_IPV6_ADDRESS: 2562 if (PF_INET6 != asoc->base.sk->sk_family) 2563 break; 2564 goto do_addr_param; 2565 2566 case SCTP_PARAM_IPV4_ADDRESS: 2567 /* v4 addresses are not allowed on v6-only socket */ 2568 if (ipv6_only_sock(asoc->base.sk)) 2569 break; 2570 do_addr_param: 2571 af = sctp_get_af_specific(param_type2af(param.p->type)); 2572 if (!af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0)) 2573 break; 2574 scope = sctp_scope(peer_addr); 2575 if (sctp_in_scope(net, &addr, scope)) 2576 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2577 return 0; 2578 break; 2579 2580 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2581 if (!net->sctp.cookie_preserve_enable) 2582 break; 2583 2584 stale = ntohl(param.life->lifespan_increment); 2585 2586 /* Suggested Cookie Life span increment's unit is msec, 2587 * (1/1000sec). 2588 */ 2589 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale); 2590 break; 2591 2592 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2593 /* Turn off the default values first so we'll know which 2594 * ones are really set by the peer. 2595 */ 2596 asoc->peer.ipv4_address = 0; 2597 asoc->peer.ipv6_address = 0; 2598 2599 /* Assume that peer supports the address family 2600 * by which it sends a packet. 2601 */ 2602 if (peer_addr->sa.sa_family == AF_INET6) 2603 asoc->peer.ipv6_address = 1; 2604 else if (peer_addr->sa.sa_family == AF_INET) 2605 asoc->peer.ipv4_address = 1; 2606 2607 /* Cycle through address types; avoid divide by 0. */ 2608 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2609 if (sat) 2610 sat /= sizeof(__u16); 2611 2612 for (i = 0; i < sat; ++i) { 2613 switch (param.sat->types[i]) { 2614 case SCTP_PARAM_IPV4_ADDRESS: 2615 asoc->peer.ipv4_address = 1; 2616 break; 2617 2618 case SCTP_PARAM_IPV6_ADDRESS: 2619 if (PF_INET6 == asoc->base.sk->sk_family) 2620 asoc->peer.ipv6_address = 1; 2621 break; 2622 2623 default: /* Just ignore anything else. */ 2624 break; 2625 } 2626 } 2627 break; 2628 2629 case SCTP_PARAM_STATE_COOKIE: 2630 asoc->peer.cookie_len = 2631 ntohs(param.p->length) - sizeof(struct sctp_paramhdr); 2632 kfree(asoc->peer.cookie); 2633 asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp); 2634 if (!asoc->peer.cookie) 2635 retval = 0; 2636 break; 2637 2638 case SCTP_PARAM_HEARTBEAT_INFO: 2639 /* Would be odd to receive, but it causes no problems. */ 2640 break; 2641 2642 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2643 /* Rejected during verify stage. */ 2644 break; 2645 2646 case SCTP_PARAM_ECN_CAPABLE: 2647 if (asoc->ep->ecn_enable) { 2648 asoc->peer.ecn_capable = 1; 2649 break; 2650 } 2651 /* Fall Through */ 2652 goto fall_through; 2653 2654 2655 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2656 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2657 break; 2658 2659 case SCTP_PARAM_SET_PRIMARY: 2660 if (!ep->asconf_enable) 2661 goto fall_through; 2662 2663 addr_param = param.v + sizeof(struct sctp_addip_param); 2664 2665 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 2666 if (!af) 2667 break; 2668 2669 if (!af->from_addr_param(&addr, addr_param, 2670 htons(asoc->peer.port), 0)) 2671 break; 2672 2673 if (!af->addr_valid(&addr, NULL, NULL)) 2674 break; 2675 2676 t = sctp_assoc_lookup_paddr(asoc, &addr); 2677 if (!t) 2678 break; 2679 2680 sctp_assoc_set_primary(asoc, t); 2681 break; 2682 2683 case SCTP_PARAM_SUPPORTED_EXT: 2684 sctp_process_ext_param(asoc, param); 2685 break; 2686 2687 case SCTP_PARAM_FWD_TSN_SUPPORT: 2688 if (asoc->ep->prsctp_enable) { 2689 asoc->peer.prsctp_capable = 1; 2690 break; 2691 } 2692 /* Fall Through */ 2693 goto fall_through; 2694 2695 case SCTP_PARAM_RANDOM: 2696 if (!ep->auth_enable) 2697 goto fall_through; 2698 2699 /* Save peer's random parameter */ 2700 kfree(asoc->peer.peer_random); 2701 asoc->peer.peer_random = kmemdup(param.p, 2702 ntohs(param.p->length), gfp); 2703 if (!asoc->peer.peer_random) { 2704 retval = 0; 2705 break; 2706 } 2707 break; 2708 2709 case SCTP_PARAM_HMAC_ALGO: 2710 if (!ep->auth_enable) 2711 goto fall_through; 2712 2713 /* Save peer's HMAC list */ 2714 kfree(asoc->peer.peer_hmacs); 2715 asoc->peer.peer_hmacs = kmemdup(param.p, 2716 ntohs(param.p->length), gfp); 2717 if (!asoc->peer.peer_hmacs) { 2718 retval = 0; 2719 break; 2720 } 2721 2722 /* Set the default HMAC the peer requested*/ 2723 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2724 break; 2725 2726 case SCTP_PARAM_CHUNKS: 2727 if (!ep->auth_enable) 2728 goto fall_through; 2729 2730 kfree(asoc->peer.peer_chunks); 2731 asoc->peer.peer_chunks = kmemdup(param.p, 2732 ntohs(param.p->length), gfp); 2733 if (!asoc->peer.peer_chunks) 2734 retval = 0; 2735 break; 2736 fall_through: 2737 default: 2738 /* Any unrecognized parameters should have been caught 2739 * and handled by sctp_verify_param() which should be 2740 * called prior to this routine. Simply log the error 2741 * here. 2742 */ 2743 pr_debug("%s: ignoring param:%d for association:%p.\n", 2744 __func__, ntohs(param.p->type), asoc); 2745 break; 2746 } 2747 2748 return retval; 2749 } 2750 2751 /* Select a new verification tag. */ sctp_generate_tag(const struct sctp_endpoint * ep)2752 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2753 { 2754 /* I believe that this random number generator complies with RFC1750. 2755 * A tag of 0 is reserved for special cases (e.g. INIT). 2756 */ 2757 __u32 x; 2758 2759 do { 2760 get_random_bytes(&x, sizeof(__u32)); 2761 } while (x == 0); 2762 2763 return x; 2764 } 2765 2766 /* Select an initial TSN to send during startup. */ sctp_generate_tsn(const struct sctp_endpoint * ep)2767 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2768 { 2769 __u32 retval; 2770 2771 get_random_bytes(&retval, sizeof(__u32)); 2772 return retval; 2773 } 2774 2775 /* 2776 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2777 * 0 1 2 3 2778 * 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 2779 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2780 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2781 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2782 * | Serial Number | 2783 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2784 * | Address Parameter | 2785 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2786 * | ASCONF Parameter #1 | 2787 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2788 * \ \ 2789 * / .... / 2790 * \ \ 2791 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2792 * | ASCONF Parameter #N | 2793 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2794 * 2795 * Address Parameter and other parameter will not be wrapped in this function 2796 */ sctp_make_asconf(struct sctp_association * asoc,union sctp_addr * addr,int vparam_len)2797 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2798 union sctp_addr *addr, 2799 int vparam_len) 2800 { 2801 struct sctp_addiphdr asconf; 2802 struct sctp_chunk *retval; 2803 int length = sizeof(asconf) + vparam_len; 2804 union sctp_addr_param addrparam; 2805 int addrlen; 2806 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2807 2808 addrlen = af->to_addr_param(addr, &addrparam); 2809 if (!addrlen) 2810 return NULL; 2811 length += addrlen; 2812 2813 /* Create the chunk. */ 2814 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length, 2815 GFP_ATOMIC); 2816 if (!retval) 2817 return NULL; 2818 2819 asconf.serial = htonl(asoc->addip_serial++); 2820 2821 retval->subh.addip_hdr = 2822 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2823 retval->param_hdr.v = 2824 sctp_addto_chunk(retval, addrlen, &addrparam); 2825 2826 return retval; 2827 } 2828 2829 /* ADDIP 2830 * 3.2.1 Add IP Address 2831 * 0 1 2 3 2832 * 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 2833 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2834 * | Type = 0xC001 | Length = Variable | 2835 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2836 * | ASCONF-Request Correlation ID | 2837 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2838 * | Address Parameter | 2839 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2840 * 2841 * 3.2.2 Delete IP Address 2842 * 0 1 2 3 2843 * 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 2844 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2845 * | Type = 0xC002 | Length = Variable | 2846 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2847 * | ASCONF-Request Correlation ID | 2848 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2849 * | Address Parameter | 2850 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2851 * 2852 */ sctp_make_asconf_update_ip(struct sctp_association * asoc,union sctp_addr * laddr,struct sockaddr * addrs,int addrcnt,__be16 flags)2853 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2854 union sctp_addr *laddr, 2855 struct sockaddr *addrs, 2856 int addrcnt, __be16 flags) 2857 { 2858 union sctp_addr_param addr_param; 2859 struct sctp_addip_param param; 2860 int paramlen = sizeof(param); 2861 struct sctp_chunk *retval; 2862 int addr_param_len = 0; 2863 union sctp_addr *addr; 2864 int totallen = 0, i; 2865 int del_pickup = 0; 2866 struct sctp_af *af; 2867 void *addr_buf; 2868 2869 /* Get total length of all the address parameters. */ 2870 addr_buf = addrs; 2871 for (i = 0; i < addrcnt; i++) { 2872 addr = addr_buf; 2873 af = sctp_get_af_specific(addr->v4.sin_family); 2874 addr_param_len = af->to_addr_param(addr, &addr_param); 2875 2876 totallen += paramlen; 2877 totallen += addr_param_len; 2878 2879 addr_buf += af->sockaddr_len; 2880 if (asoc->asconf_addr_del_pending && !del_pickup) { 2881 /* reuse the parameter length from the same scope one */ 2882 totallen += paramlen; 2883 totallen += addr_param_len; 2884 del_pickup = 1; 2885 2886 pr_debug("%s: picked same-scope del_pending addr, " 2887 "totallen for all addresses is %d\n", 2888 __func__, totallen); 2889 } 2890 } 2891 2892 /* Create an asconf chunk with the required length. */ 2893 retval = sctp_make_asconf(asoc, laddr, totallen); 2894 if (!retval) 2895 return NULL; 2896 2897 /* Add the address parameters to the asconf chunk. */ 2898 addr_buf = addrs; 2899 for (i = 0; i < addrcnt; i++) { 2900 addr = addr_buf; 2901 af = sctp_get_af_specific(addr->v4.sin_family); 2902 addr_param_len = af->to_addr_param(addr, &addr_param); 2903 param.param_hdr.type = flags; 2904 param.param_hdr.length = htons(paramlen + addr_param_len); 2905 param.crr_id = htonl(i); 2906 2907 sctp_addto_chunk(retval, paramlen, ¶m); 2908 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2909 2910 addr_buf += af->sockaddr_len; 2911 } 2912 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2913 addr = asoc->asconf_addr_del_pending; 2914 af = sctp_get_af_specific(addr->v4.sin_family); 2915 addr_param_len = af->to_addr_param(addr, &addr_param); 2916 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2917 param.param_hdr.length = htons(paramlen + addr_param_len); 2918 param.crr_id = htonl(i); 2919 2920 sctp_addto_chunk(retval, paramlen, ¶m); 2921 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2922 } 2923 return retval; 2924 } 2925 2926 /* ADDIP 2927 * 3.2.4 Set Primary IP Address 2928 * 0 1 2 3 2929 * 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 2930 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2931 * | Type =0xC004 | Length = Variable | 2932 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2933 * | ASCONF-Request Correlation ID | 2934 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2935 * | Address Parameter | 2936 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2937 * 2938 * Create an ASCONF chunk with Set Primary IP address parameter. 2939 */ sctp_make_asconf_set_prim(struct sctp_association * asoc,union sctp_addr * addr)2940 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2941 union sctp_addr *addr) 2942 { 2943 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2944 union sctp_addr_param addrparam; 2945 struct sctp_addip_param param; 2946 struct sctp_chunk *retval; 2947 int len = sizeof(param); 2948 int addrlen; 2949 2950 addrlen = af->to_addr_param(addr, &addrparam); 2951 if (!addrlen) 2952 return NULL; 2953 len += addrlen; 2954 2955 /* Create the chunk and make asconf header. */ 2956 retval = sctp_make_asconf(asoc, addr, len); 2957 if (!retval) 2958 return NULL; 2959 2960 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2961 param.param_hdr.length = htons(len); 2962 param.crr_id = 0; 2963 2964 sctp_addto_chunk(retval, sizeof(param), ¶m); 2965 sctp_addto_chunk(retval, addrlen, &addrparam); 2966 2967 return retval; 2968 } 2969 2970 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2971 * 0 1 2 3 2972 * 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 2973 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2974 * | Type = 0x80 | Chunk Flags | Chunk Length | 2975 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2976 * | Serial Number | 2977 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2978 * | ASCONF Parameter Response#1 | 2979 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2980 * \ \ 2981 * / .... / 2982 * \ \ 2983 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2984 * | ASCONF Parameter Response#N | 2985 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2986 * 2987 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2988 */ sctp_make_asconf_ack(const struct sctp_association * asoc,__u32 serial,int vparam_len)2989 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2990 __u32 serial, int vparam_len) 2991 { 2992 struct sctp_addiphdr asconf; 2993 struct sctp_chunk *retval; 2994 int length = sizeof(asconf) + vparam_len; 2995 2996 /* Create the chunk. */ 2997 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length, 2998 GFP_ATOMIC); 2999 if (!retval) 3000 return NULL; 3001 3002 asconf.serial = htonl(serial); 3003 3004 retval->subh.addip_hdr = 3005 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 3006 3007 return retval; 3008 } 3009 3010 /* Add response parameters to an ASCONF_ACK chunk. */ sctp_add_asconf_response(struct sctp_chunk * chunk,__be32 crr_id,__be16 err_code,struct sctp_addip_param * asconf_param)3011 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 3012 __be16 err_code, 3013 struct sctp_addip_param *asconf_param) 3014 { 3015 struct sctp_addip_param ack_param; 3016 struct sctp_errhdr err_param; 3017 int asconf_param_len = 0; 3018 int err_param_len = 0; 3019 __be16 response_type; 3020 3021 if (SCTP_ERROR_NO_ERROR == err_code) { 3022 response_type = SCTP_PARAM_SUCCESS_REPORT; 3023 } else { 3024 response_type = SCTP_PARAM_ERR_CAUSE; 3025 err_param_len = sizeof(err_param); 3026 if (asconf_param) 3027 asconf_param_len = 3028 ntohs(asconf_param->param_hdr.length); 3029 } 3030 3031 /* Add Success Indication or Error Cause Indication parameter. */ 3032 ack_param.param_hdr.type = response_type; 3033 ack_param.param_hdr.length = htons(sizeof(ack_param) + 3034 err_param_len + 3035 asconf_param_len); 3036 ack_param.crr_id = crr_id; 3037 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 3038 3039 if (SCTP_ERROR_NO_ERROR == err_code) 3040 return; 3041 3042 /* Add Error Cause parameter. */ 3043 err_param.cause = err_code; 3044 err_param.length = htons(err_param_len + asconf_param_len); 3045 sctp_addto_chunk(chunk, err_param_len, &err_param); 3046 3047 /* Add the failed TLV copied from ASCONF chunk. */ 3048 if (asconf_param) 3049 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 3050 } 3051 3052 /* Process a asconf parameter. */ sctp_process_asconf_param(struct sctp_association * asoc,struct sctp_chunk * asconf,struct sctp_addip_param * asconf_param)3053 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 3054 struct sctp_chunk *asconf, 3055 struct sctp_addip_param *asconf_param) 3056 { 3057 union sctp_addr_param *addr_param; 3058 struct sctp_transport *peer; 3059 union sctp_addr addr; 3060 struct sctp_af *af; 3061 3062 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3063 3064 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 3065 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 3066 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 3067 return SCTP_ERROR_UNKNOWN_PARAM; 3068 3069 switch (addr_param->p.type) { 3070 case SCTP_PARAM_IPV6_ADDRESS: 3071 if (!asoc->peer.ipv6_address) 3072 return SCTP_ERROR_DNS_FAILED; 3073 break; 3074 case SCTP_PARAM_IPV4_ADDRESS: 3075 if (!asoc->peer.ipv4_address) 3076 return SCTP_ERROR_DNS_FAILED; 3077 break; 3078 default: 3079 return SCTP_ERROR_DNS_FAILED; 3080 } 3081 3082 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3083 if (unlikely(!af)) 3084 return SCTP_ERROR_DNS_FAILED; 3085 3086 if (!af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0)) 3087 return SCTP_ERROR_DNS_FAILED; 3088 3089 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3090 * or multicast address. 3091 * (note: wildcard is permitted and requires special handling so 3092 * make sure we check for that) 3093 */ 3094 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3095 return SCTP_ERROR_DNS_FAILED; 3096 3097 switch (asconf_param->param_hdr.type) { 3098 case SCTP_PARAM_ADD_IP: 3099 /* Section 4.2.1: 3100 * If the address 0.0.0.0 or ::0 is provided, the source 3101 * address of the packet MUST be added. 3102 */ 3103 if (af->is_any(&addr)) 3104 memcpy(&addr, &asconf->source, sizeof(addr)); 3105 3106 if (security_sctp_bind_connect(asoc->ep->base.sk, 3107 SCTP_PARAM_ADD_IP, 3108 (struct sockaddr *)&addr, 3109 af->sockaddr_len)) 3110 return SCTP_ERROR_REQ_REFUSED; 3111 3112 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3113 * request and does not have the local resources to add this 3114 * new address to the association, it MUST return an Error 3115 * Cause TLV set to the new error code 'Operation Refused 3116 * Due to Resource Shortage'. 3117 */ 3118 3119 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3120 if (!peer) 3121 return SCTP_ERROR_RSRC_LOW; 3122 3123 /* Start the heartbeat timer. */ 3124 sctp_transport_reset_hb_timer(peer); 3125 asoc->new_transport = peer; 3126 break; 3127 case SCTP_PARAM_DEL_IP: 3128 /* ADDIP 4.3 D7) If a request is received to delete the 3129 * last remaining IP address of a peer endpoint, the receiver 3130 * MUST send an Error Cause TLV with the error cause set to the 3131 * new error code 'Request to Delete Last Remaining IP Address'. 3132 */ 3133 if (asoc->peer.transport_count == 1) 3134 return SCTP_ERROR_DEL_LAST_IP; 3135 3136 /* ADDIP 4.3 D8) If a request is received to delete an IP 3137 * address which is also the source address of the IP packet 3138 * which contained the ASCONF chunk, the receiver MUST reject 3139 * this request. To reject the request the receiver MUST send 3140 * an Error Cause TLV set to the new error code 'Request to 3141 * Delete Source IP Address' 3142 */ 3143 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3144 return SCTP_ERROR_DEL_SRC_IP; 3145 3146 /* Section 4.2.2 3147 * If the address 0.0.0.0 or ::0 is provided, all 3148 * addresses of the peer except the source address of the 3149 * packet MUST be deleted. 3150 */ 3151 if (af->is_any(&addr)) { 3152 sctp_assoc_set_primary(asoc, asconf->transport); 3153 sctp_assoc_del_nonprimary_peers(asoc, 3154 asconf->transport); 3155 return SCTP_ERROR_NO_ERROR; 3156 } 3157 3158 /* If the address is not part of the association, the 3159 * ASCONF-ACK with Error Cause Indication Parameter 3160 * which including cause of Unresolvable Address should 3161 * be sent. 3162 */ 3163 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3164 if (!peer) 3165 return SCTP_ERROR_DNS_FAILED; 3166 3167 sctp_assoc_rm_peer(asoc, peer); 3168 break; 3169 case SCTP_PARAM_SET_PRIMARY: 3170 /* ADDIP Section 4.2.4 3171 * If the address 0.0.0.0 or ::0 is provided, the receiver 3172 * MAY mark the source address of the packet as its 3173 * primary. 3174 */ 3175 if (af->is_any(&addr)) 3176 memcpy(&addr, sctp_source(asconf), sizeof(addr)); 3177 3178 if (security_sctp_bind_connect(asoc->ep->base.sk, 3179 SCTP_PARAM_SET_PRIMARY, 3180 (struct sockaddr *)&addr, 3181 af->sockaddr_len)) 3182 return SCTP_ERROR_REQ_REFUSED; 3183 3184 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3185 if (!peer) 3186 return SCTP_ERROR_DNS_FAILED; 3187 3188 sctp_assoc_set_primary(asoc, peer); 3189 break; 3190 } 3191 3192 return SCTP_ERROR_NO_ERROR; 3193 } 3194 3195 /* Verify the ASCONF packet before we process it. */ sctp_verify_asconf(const struct sctp_association * asoc,struct sctp_chunk * chunk,bool addr_param_needed,struct sctp_paramhdr ** errp)3196 bool sctp_verify_asconf(const struct sctp_association *asoc, 3197 struct sctp_chunk *chunk, bool addr_param_needed, 3198 struct sctp_paramhdr **errp) 3199 { 3200 struct sctp_addip_chunk *addip; 3201 bool addr_param_seen = false; 3202 union sctp_params param; 3203 3204 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr; 3205 sctp_walk_params(param, addip) { 3206 size_t length = ntohs(param.p->length); 3207 3208 *errp = param.p; 3209 switch (param.p->type) { 3210 case SCTP_PARAM_ERR_CAUSE: 3211 break; 3212 case SCTP_PARAM_IPV4_ADDRESS: 3213 if (length != sizeof(struct sctp_ipv4addr_param)) 3214 return false; 3215 /* ensure there is only one addr param and it's in the 3216 * beginning of addip_hdr params, or we reject it. 3217 */ 3218 if (param.v != (addip + 1)) 3219 return false; 3220 addr_param_seen = true; 3221 break; 3222 case SCTP_PARAM_IPV6_ADDRESS: 3223 if (length != sizeof(struct sctp_ipv6addr_param)) 3224 return false; 3225 if (param.v != (addip + 1)) 3226 return false; 3227 addr_param_seen = true; 3228 break; 3229 case SCTP_PARAM_ADD_IP: 3230 case SCTP_PARAM_DEL_IP: 3231 case SCTP_PARAM_SET_PRIMARY: 3232 /* In ASCONF chunks, these need to be first. */ 3233 if (addr_param_needed && !addr_param_seen) 3234 return false; 3235 length = ntohs(param.addip->param_hdr.length); 3236 if (length < sizeof(struct sctp_addip_param) + 3237 sizeof(**errp)) 3238 return false; 3239 break; 3240 case SCTP_PARAM_SUCCESS_REPORT: 3241 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3242 if (length != sizeof(struct sctp_addip_param)) 3243 return false; 3244 break; 3245 default: 3246 /* This is unknown to us, reject! */ 3247 return false; 3248 } 3249 } 3250 3251 /* Remaining sanity checks. */ 3252 if (addr_param_needed && !addr_param_seen) 3253 return false; 3254 if (!addr_param_needed && addr_param_seen) 3255 return false; 3256 if (param.v != chunk->chunk_end) 3257 return false; 3258 3259 return true; 3260 } 3261 3262 /* Process an incoming ASCONF chunk with the next expected serial no. and 3263 * return an ASCONF_ACK chunk to be sent in response. 3264 */ sctp_process_asconf(struct sctp_association * asoc,struct sctp_chunk * asconf)3265 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3266 struct sctp_chunk *asconf) 3267 { 3268 union sctp_addr_param *addr_param; 3269 struct sctp_addip_chunk *addip; 3270 struct sctp_chunk *asconf_ack; 3271 bool all_param_pass = true; 3272 struct sctp_addiphdr *hdr; 3273 int length = 0, chunk_len; 3274 union sctp_params param; 3275 __be16 err_code; 3276 __u32 serial; 3277 3278 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr; 3279 chunk_len = ntohs(asconf->chunk_hdr->length) - 3280 sizeof(struct sctp_chunkhdr); 3281 hdr = (struct sctp_addiphdr *)asconf->skb->data; 3282 serial = ntohl(hdr->serial); 3283 3284 /* Skip the addiphdr and store a pointer to address parameter. */ 3285 length = sizeof(*hdr); 3286 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3287 chunk_len -= length; 3288 3289 /* Skip the address parameter and store a pointer to the first 3290 * asconf parameter. 3291 */ 3292 length = ntohs(addr_param->p.length); 3293 chunk_len -= length; 3294 3295 /* create an ASCONF_ACK chunk. 3296 * Based on the definitions of parameters, we know that the size of 3297 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3298 * parameters. 3299 */ 3300 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3301 if (!asconf_ack) 3302 goto done; 3303 3304 /* Process the TLVs contained within the ASCONF chunk. */ 3305 sctp_walk_params(param, addip) { 3306 /* Skip preceding address parameters. */ 3307 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 3308 param.p->type == SCTP_PARAM_IPV6_ADDRESS) 3309 continue; 3310 3311 err_code = sctp_process_asconf_param(asoc, asconf, 3312 param.addip); 3313 /* ADDIP 4.1 A7) 3314 * If an error response is received for a TLV parameter, 3315 * all TLVs with no response before the failed TLV are 3316 * considered successful if not reported. All TLVs after 3317 * the failed response are considered unsuccessful unless 3318 * a specific success indication is present for the parameter. 3319 */ 3320 if (err_code != SCTP_ERROR_NO_ERROR) 3321 all_param_pass = false; 3322 if (!all_param_pass) 3323 sctp_add_asconf_response(asconf_ack, param.addip->crr_id, 3324 err_code, param.addip); 3325 3326 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3327 * an IP address sends an 'Out of Resource' in its response, it 3328 * MUST also fail any subsequent add or delete requests bundled 3329 * in the ASCONF. 3330 */ 3331 if (err_code == SCTP_ERROR_RSRC_LOW) 3332 goto done; 3333 } 3334 done: 3335 asoc->peer.addip_serial++; 3336 3337 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3338 * after freeing the reference to old asconf ack if any. 3339 */ 3340 if (asconf_ack) { 3341 sctp_chunk_hold(asconf_ack); 3342 list_add_tail(&asconf_ack->transmitted_list, 3343 &asoc->asconf_ack_list); 3344 } 3345 3346 return asconf_ack; 3347 } 3348 3349 /* Process a asconf parameter that is successfully acked. */ sctp_asconf_param_success(struct sctp_association * asoc,struct sctp_addip_param * asconf_param)3350 static void sctp_asconf_param_success(struct sctp_association *asoc, 3351 struct sctp_addip_param *asconf_param) 3352 { 3353 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3354 union sctp_addr_param *addr_param; 3355 struct sctp_sockaddr_entry *saddr; 3356 struct sctp_transport *transport; 3357 union sctp_addr addr; 3358 struct sctp_af *af; 3359 3360 addr_param = (void *)asconf_param + sizeof(*asconf_param); 3361 3362 /* We have checked the packet before, so we do not check again. */ 3363 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3364 if (!af->from_addr_param(&addr, addr_param, htons(bp->port), 0)) 3365 return; 3366 3367 switch (asconf_param->param_hdr.type) { 3368 case SCTP_PARAM_ADD_IP: 3369 /* This is always done in BH context with a socket lock 3370 * held, so the list can not change. 3371 */ 3372 local_bh_disable(); 3373 list_for_each_entry(saddr, &bp->address_list, list) { 3374 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3375 saddr->state = SCTP_ADDR_SRC; 3376 } 3377 local_bh_enable(); 3378 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3379 transports) { 3380 sctp_transport_dst_release(transport); 3381 } 3382 break; 3383 case SCTP_PARAM_DEL_IP: 3384 local_bh_disable(); 3385 sctp_del_bind_addr(bp, &addr); 3386 if (asoc->asconf_addr_del_pending != NULL && 3387 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3388 kfree(asoc->asconf_addr_del_pending); 3389 asoc->asconf_addr_del_pending = NULL; 3390 } 3391 local_bh_enable(); 3392 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3393 transports) { 3394 sctp_transport_dst_release(transport); 3395 } 3396 break; 3397 default: 3398 break; 3399 } 3400 } 3401 3402 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3403 * for the given asconf parameter. If there is no response for this parameter, 3404 * return the error code based on the third argument 'no_err'. 3405 * ADDIP 4.1 3406 * A7) If an error response is received for a TLV parameter, all TLVs with no 3407 * response before the failed TLV are considered successful if not reported. 3408 * All TLVs after the failed response are considered unsuccessful unless a 3409 * specific success indication is present for the parameter. 3410 */ sctp_get_asconf_response(struct sctp_chunk * asconf_ack,struct sctp_addip_param * asconf_param,int no_err)3411 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3412 struct sctp_addip_param *asconf_param, 3413 int no_err) 3414 { 3415 struct sctp_addip_param *asconf_ack_param; 3416 struct sctp_errhdr *err_param; 3417 int asconf_ack_len; 3418 __be16 err_code; 3419 int length; 3420 3421 if (no_err) 3422 err_code = SCTP_ERROR_NO_ERROR; 3423 else 3424 err_code = SCTP_ERROR_REQ_REFUSED; 3425 3426 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3427 sizeof(struct sctp_chunkhdr); 3428 3429 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3430 * the first asconf_ack parameter. 3431 */ 3432 length = sizeof(struct sctp_addiphdr); 3433 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data + 3434 length); 3435 asconf_ack_len -= length; 3436 3437 while (asconf_ack_len > 0) { 3438 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3439 switch (asconf_ack_param->param_hdr.type) { 3440 case SCTP_PARAM_SUCCESS_REPORT: 3441 return SCTP_ERROR_NO_ERROR; 3442 case SCTP_PARAM_ERR_CAUSE: 3443 length = sizeof(*asconf_ack_param); 3444 err_param = (void *)asconf_ack_param + length; 3445 asconf_ack_len -= length; 3446 if (asconf_ack_len > 0) 3447 return err_param->cause; 3448 else 3449 return SCTP_ERROR_INV_PARAM; 3450 break; 3451 default: 3452 return SCTP_ERROR_INV_PARAM; 3453 } 3454 } 3455 3456 length = ntohs(asconf_ack_param->param_hdr.length); 3457 asconf_ack_param = (void *)asconf_ack_param + length; 3458 asconf_ack_len -= length; 3459 } 3460 3461 return err_code; 3462 } 3463 3464 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ sctp_process_asconf_ack(struct sctp_association * asoc,struct sctp_chunk * asconf_ack)3465 int sctp_process_asconf_ack(struct sctp_association *asoc, 3466 struct sctp_chunk *asconf_ack) 3467 { 3468 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3469 struct sctp_addip_param *asconf_param; 3470 __be16 err_code = SCTP_ERROR_NO_ERROR; 3471 union sctp_addr_param *addr_param; 3472 int asconf_len = asconf->skb->len; 3473 int all_param_pass = 0; 3474 int length = 0; 3475 int no_err = 1; 3476 int retval = 0; 3477 3478 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3479 * a pointer to address parameter. 3480 */ 3481 length = sizeof(struct sctp_addip_chunk); 3482 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3483 asconf_len -= length; 3484 3485 /* Skip the address parameter in the last asconf sent and store a 3486 * pointer to the first asconf parameter. 3487 */ 3488 length = ntohs(addr_param->p.length); 3489 asconf_param = (void *)addr_param + length; 3490 asconf_len -= length; 3491 3492 /* ADDIP 4.1 3493 * A8) If there is no response(s) to specific TLV parameter(s), and no 3494 * failures are indicated, then all request(s) are considered 3495 * successful. 3496 */ 3497 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr)) 3498 all_param_pass = 1; 3499 3500 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3501 while (asconf_len > 0) { 3502 if (all_param_pass) 3503 err_code = SCTP_ERROR_NO_ERROR; 3504 else { 3505 err_code = sctp_get_asconf_response(asconf_ack, 3506 asconf_param, 3507 no_err); 3508 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3509 no_err = 0; 3510 } 3511 3512 switch (err_code) { 3513 case SCTP_ERROR_NO_ERROR: 3514 sctp_asconf_param_success(asoc, asconf_param); 3515 break; 3516 3517 case SCTP_ERROR_RSRC_LOW: 3518 retval = 1; 3519 break; 3520 3521 case SCTP_ERROR_UNKNOWN_PARAM: 3522 /* Disable sending this type of asconf parameter in 3523 * future. 3524 */ 3525 asoc->peer.addip_disabled_mask |= 3526 asconf_param->param_hdr.type; 3527 break; 3528 3529 case SCTP_ERROR_REQ_REFUSED: 3530 case SCTP_ERROR_DEL_LAST_IP: 3531 case SCTP_ERROR_DEL_SRC_IP: 3532 default: 3533 break; 3534 } 3535 3536 /* Skip the processed asconf parameter and move to the next 3537 * one. 3538 */ 3539 length = ntohs(asconf_param->param_hdr.length); 3540 asconf_param = (void *)asconf_param + length; 3541 asconf_len -= length; 3542 } 3543 3544 if (no_err && asoc->src_out_of_asoc_ok) { 3545 asoc->src_out_of_asoc_ok = 0; 3546 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3547 } 3548 3549 /* Free the cached last sent asconf chunk. */ 3550 list_del_init(&asconf->transmitted_list); 3551 sctp_chunk_free(asconf); 3552 asoc->addip_last_asconf = NULL; 3553 3554 return retval; 3555 } 3556 3557 /* Make a FWD TSN chunk. */ sctp_make_fwdtsn(const struct sctp_association * asoc,__u32 new_cum_tsn,size_t nstreams,struct sctp_fwdtsn_skip * skiplist)3558 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3559 __u32 new_cum_tsn, size_t nstreams, 3560 struct sctp_fwdtsn_skip *skiplist) 3561 { 3562 struct sctp_chunk *retval = NULL; 3563 struct sctp_fwdtsn_hdr ftsn_hdr; 3564 struct sctp_fwdtsn_skip skip; 3565 size_t hint; 3566 int i; 3567 3568 hint = (nstreams + 1) * sizeof(__u32); 3569 3570 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC); 3571 3572 if (!retval) 3573 return NULL; 3574 3575 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3576 retval->subh.fwdtsn_hdr = 3577 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3578 3579 for (i = 0; i < nstreams; i++) { 3580 skip.stream = skiplist[i].stream; 3581 skip.ssn = skiplist[i].ssn; 3582 sctp_addto_chunk(retval, sizeof(skip), &skip); 3583 } 3584 3585 return retval; 3586 } 3587 sctp_make_ifwdtsn(const struct sctp_association * asoc,__u32 new_cum_tsn,size_t nstreams,struct sctp_ifwdtsn_skip * skiplist)3588 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc, 3589 __u32 new_cum_tsn, size_t nstreams, 3590 struct sctp_ifwdtsn_skip *skiplist) 3591 { 3592 struct sctp_chunk *retval = NULL; 3593 struct sctp_ifwdtsn_hdr ftsn_hdr; 3594 size_t hint; 3595 3596 hint = (nstreams + 1) * sizeof(__u32); 3597 3598 retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint, 3599 GFP_ATOMIC); 3600 if (!retval) 3601 return NULL; 3602 3603 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3604 retval->subh.ifwdtsn_hdr = 3605 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3606 3607 sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist); 3608 3609 return retval; 3610 } 3611 3612 /* RE-CONFIG 3.1 (RE-CONFIG chunk) 3613 * 0 1 2 3 3614 * 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 3615 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3616 * | Type = 130 | Chunk Flags | Chunk Length | 3617 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3618 * \ \ 3619 * / Re-configuration Parameter / 3620 * \ \ 3621 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3622 * \ \ 3623 * / Re-configuration Parameter (optional) / 3624 * \ \ 3625 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3626 */ sctp_make_reconf(const struct sctp_association * asoc,int length)3627 static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc, 3628 int length) 3629 { 3630 struct sctp_reconf_chunk *reconf; 3631 struct sctp_chunk *retval; 3632 3633 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length, 3634 GFP_ATOMIC); 3635 if (!retval) 3636 return NULL; 3637 3638 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr; 3639 retval->param_hdr.v = (u8 *)(reconf + 1); 3640 3641 return retval; 3642 } 3643 3644 /* RE-CONFIG 4.1 (STREAM OUT RESET) 3645 * 0 1 2 3 3646 * 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 3647 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3648 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N | 3649 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3650 * | Re-configuration Request Sequence Number | 3651 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3652 * | Re-configuration Response Sequence Number | 3653 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3654 * | Sender's Last Assigned TSN | 3655 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3656 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3657 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3658 * / ...... / 3659 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3660 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3661 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3662 * 3663 * RE-CONFIG 4.2 (STREAM IN RESET) 3664 * 0 1 2 3 3665 * 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 3666 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3667 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N | 3668 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3669 * | Re-configuration Request Sequence Number | 3670 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3671 * | Stream Number 1 (optional) | Stream Number 2 (optional) | 3672 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3673 * / ...... / 3674 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3675 * | Stream Number N-1 (optional) | Stream Number N (optional) | 3676 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3677 */ sctp_make_strreset_req(const struct sctp_association * asoc,__u16 stream_num,__be16 * stream_list,bool out,bool in)3678 struct sctp_chunk *sctp_make_strreset_req( 3679 const struct sctp_association *asoc, 3680 __u16 stream_num, __be16 *stream_list, 3681 bool out, bool in) 3682 { 3683 __u16 stream_len = stream_num * sizeof(__u16); 3684 struct sctp_strreset_outreq outreq; 3685 struct sctp_strreset_inreq inreq; 3686 struct sctp_chunk *retval; 3687 __u16 outlen, inlen; 3688 3689 outlen = (sizeof(outreq) + stream_len) * out; 3690 inlen = (sizeof(inreq) + stream_len) * in; 3691 3692 retval = sctp_make_reconf(asoc, SCTP_PAD4(outlen) + SCTP_PAD4(inlen)); 3693 if (!retval) 3694 return NULL; 3695 3696 if (outlen) { 3697 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST; 3698 outreq.param_hdr.length = htons(outlen); 3699 outreq.request_seq = htonl(asoc->strreset_outseq); 3700 outreq.response_seq = htonl(asoc->strreset_inseq - 1); 3701 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1); 3702 3703 sctp_addto_chunk(retval, sizeof(outreq), &outreq); 3704 3705 if (stream_len) 3706 sctp_addto_chunk(retval, stream_len, stream_list); 3707 } 3708 3709 if (inlen) { 3710 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST; 3711 inreq.param_hdr.length = htons(inlen); 3712 inreq.request_seq = htonl(asoc->strreset_outseq + out); 3713 3714 sctp_addto_chunk(retval, sizeof(inreq), &inreq); 3715 3716 if (stream_len) 3717 sctp_addto_chunk(retval, stream_len, stream_list); 3718 } 3719 3720 return retval; 3721 } 3722 3723 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL) 3724 * 0 1 2 3 3725 * 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 3726 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3727 * | Parameter Type = 15 | Parameter Length = 8 | 3728 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3729 * | Re-configuration Request Sequence Number | 3730 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3731 */ sctp_make_strreset_tsnreq(const struct sctp_association * asoc)3732 struct sctp_chunk *sctp_make_strreset_tsnreq( 3733 const struct sctp_association *asoc) 3734 { 3735 struct sctp_strreset_tsnreq tsnreq; 3736 __u16 length = sizeof(tsnreq); 3737 struct sctp_chunk *retval; 3738 3739 retval = sctp_make_reconf(asoc, length); 3740 if (!retval) 3741 return NULL; 3742 3743 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST; 3744 tsnreq.param_hdr.length = htons(length); 3745 tsnreq.request_seq = htonl(asoc->strreset_outseq); 3746 3747 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq); 3748 3749 return retval; 3750 } 3751 3752 /* RE-CONFIG 4.5/4.6 (ADD STREAM) 3753 * 0 1 2 3 3754 * 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 3755 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3756 * | Parameter Type = 17 | Parameter Length = 12 | 3757 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3758 * | Re-configuration Request Sequence Number | 3759 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3760 * | Number of new streams | Reserved | 3761 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3762 */ sctp_make_strreset_addstrm(const struct sctp_association * asoc,__u16 out,__u16 in)3763 struct sctp_chunk *sctp_make_strreset_addstrm( 3764 const struct sctp_association *asoc, 3765 __u16 out, __u16 in) 3766 { 3767 struct sctp_strreset_addstrm addstrm; 3768 __u16 size = sizeof(addstrm); 3769 struct sctp_chunk *retval; 3770 3771 retval = sctp_make_reconf(asoc, (!!out + !!in) * size); 3772 if (!retval) 3773 return NULL; 3774 3775 if (out) { 3776 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS; 3777 addstrm.param_hdr.length = htons(size); 3778 addstrm.number_of_streams = htons(out); 3779 addstrm.request_seq = htonl(asoc->strreset_outseq); 3780 addstrm.reserved = 0; 3781 3782 sctp_addto_chunk(retval, size, &addstrm); 3783 } 3784 3785 if (in) { 3786 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS; 3787 addstrm.param_hdr.length = htons(size); 3788 addstrm.number_of_streams = htons(in); 3789 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out); 3790 addstrm.reserved = 0; 3791 3792 sctp_addto_chunk(retval, size, &addstrm); 3793 } 3794 3795 return retval; 3796 } 3797 3798 /* RE-CONFIG 4.4 (RESP) 3799 * 0 1 2 3 3800 * 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 3801 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3802 * | Parameter Type = 16 | Parameter Length | 3803 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3804 * | Re-configuration Response Sequence Number | 3805 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3806 * | Result | 3807 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3808 */ sctp_make_strreset_resp(const struct sctp_association * asoc,__u32 result,__u32 sn)3809 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc, 3810 __u32 result, __u32 sn) 3811 { 3812 struct sctp_strreset_resp resp; 3813 __u16 length = sizeof(resp); 3814 struct sctp_chunk *retval; 3815 3816 retval = sctp_make_reconf(asoc, length); 3817 if (!retval) 3818 return NULL; 3819 3820 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3821 resp.param_hdr.length = htons(length); 3822 resp.response_seq = htonl(sn); 3823 resp.result = htonl(result); 3824 3825 sctp_addto_chunk(retval, sizeof(resp), &resp); 3826 3827 return retval; 3828 } 3829 3830 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP) 3831 * 0 1 2 3 3832 * 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 3833 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3834 * | Parameter Type = 16 | Parameter Length | 3835 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3836 * | Re-configuration Response Sequence Number | 3837 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3838 * | Result | 3839 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3840 * | Sender's Next TSN (optional) | 3841 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3842 * | Receiver's Next TSN (optional) | 3843 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3844 */ sctp_make_strreset_tsnresp(struct sctp_association * asoc,__u32 result,__u32 sn,__u32 sender_tsn,__u32 receiver_tsn)3845 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc, 3846 __u32 result, __u32 sn, 3847 __u32 sender_tsn, 3848 __u32 receiver_tsn) 3849 { 3850 struct sctp_strreset_resptsn tsnresp; 3851 __u16 length = sizeof(tsnresp); 3852 struct sctp_chunk *retval; 3853 3854 retval = sctp_make_reconf(asoc, length); 3855 if (!retval) 3856 return NULL; 3857 3858 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE; 3859 tsnresp.param_hdr.length = htons(length); 3860 3861 tsnresp.response_seq = htonl(sn); 3862 tsnresp.result = htonl(result); 3863 tsnresp.senders_next_tsn = htonl(sender_tsn); 3864 tsnresp.receivers_next_tsn = htonl(receiver_tsn); 3865 3866 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp); 3867 3868 return retval; 3869 } 3870 sctp_verify_reconf(const struct sctp_association * asoc,struct sctp_chunk * chunk,struct sctp_paramhdr ** errp)3871 bool sctp_verify_reconf(const struct sctp_association *asoc, 3872 struct sctp_chunk *chunk, 3873 struct sctp_paramhdr **errp) 3874 { 3875 struct sctp_reconf_chunk *hdr; 3876 union sctp_params param; 3877 __be16 last = 0; 3878 __u16 cnt = 0; 3879 3880 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr; 3881 sctp_walk_params(param, hdr) { 3882 __u16 length = ntohs(param.p->length); 3883 3884 *errp = param.p; 3885 if (cnt++ > 2) 3886 return false; 3887 switch (param.p->type) { 3888 case SCTP_PARAM_RESET_OUT_REQUEST: 3889 if (length < sizeof(struct sctp_strreset_outreq) || 3890 (last && last != SCTP_PARAM_RESET_RESPONSE && 3891 last != SCTP_PARAM_RESET_IN_REQUEST)) 3892 return false; 3893 break; 3894 case SCTP_PARAM_RESET_IN_REQUEST: 3895 if (length < sizeof(struct sctp_strreset_inreq) || 3896 (last && last != SCTP_PARAM_RESET_OUT_REQUEST)) 3897 return false; 3898 break; 3899 case SCTP_PARAM_RESET_RESPONSE: 3900 if ((length != sizeof(struct sctp_strreset_resp) && 3901 length != sizeof(struct sctp_strreset_resptsn)) || 3902 (last && last != SCTP_PARAM_RESET_RESPONSE && 3903 last != SCTP_PARAM_RESET_OUT_REQUEST)) 3904 return false; 3905 break; 3906 case SCTP_PARAM_RESET_TSN_REQUEST: 3907 if (length != 3908 sizeof(struct sctp_strreset_tsnreq) || last) 3909 return false; 3910 break; 3911 case SCTP_PARAM_RESET_ADD_IN_STREAMS: 3912 if (length != sizeof(struct sctp_strreset_addstrm) || 3913 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS)) 3914 return false; 3915 break; 3916 case SCTP_PARAM_RESET_ADD_OUT_STREAMS: 3917 if (length != sizeof(struct sctp_strreset_addstrm) || 3918 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS)) 3919 return false; 3920 break; 3921 default: 3922 return false; 3923 } 3924 3925 last = param.p->type; 3926 } 3927 3928 return true; 3929 } 3930