1 /* SCTP kernel implementation 2 * (C) Copyright IBM Corp. 2001, 2004 3 * Copyright (c) 1999-2000 Cisco, Inc. 4 * Copyright (c) 1999-2001 Motorola, Inc. 5 * Copyright (c) 2001-2002 Intel Corp. 6 * 7 * This file is part of the SCTP kernel implementation 8 * 9 * These functions work with the state functions in sctp_sm_statefuns.c 10 * to implement the state operations. These functions implement the 11 * steps which require modifying existing data structures. 12 * 13 * This SCTP implementation is free software; 14 * you can redistribute it and/or modify it under the terms of 15 * the GNU General Public License as published by 16 * the Free Software Foundation; either version 2, or (at your option) 17 * any later version. 18 * 19 * This SCTP implementation is distributed in the hope that it 20 * will be useful, but WITHOUT ANY WARRANTY; without even the implied 21 * ************************ 22 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 23 * See the GNU General Public License for more details. 24 * 25 * You should have received a copy of the GNU General Public License 26 * along with GNU CC; see the file COPYING. If not, see 27 * <http://www.gnu.org/licenses/>. 28 * 29 * Please send any bug reports or fixes you make to the 30 * email address(es): 31 * lksctp developers <linux-sctp@vger.kernel.org> 32 * 33 * Written or modified by: 34 * La Monte H.P. Yarroll <piggy@acm.org> 35 * Karl Knutson <karl@athena.chicago.il.us> 36 * C. Robin <chris@hundredacre.ac.uk> 37 * Jon Grimm <jgrimm@us.ibm.com> 38 * Xingang Guo <xingang.guo@intel.com> 39 * Dajiang Zhang <dajiang.zhang@nokia.com> 40 * Sridhar Samudrala <sri@us.ibm.com> 41 * Daisy Chang <daisyc@us.ibm.com> 42 * Ardelle Fan <ardelle.fan@intel.com> 43 * Kevin Gao <kevin.gao@intel.com> 44 */ 45 46 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 47 48 #include <crypto/hash.h> 49 #include <linux/types.h> 50 #include <linux/kernel.h> 51 #include <linux/ip.h> 52 #include <linux/ipv6.h> 53 #include <linux/net.h> 54 #include <linux/inet.h> 55 #include <linux/scatterlist.h> 56 #include <linux/slab.h> 57 #include <net/sock.h> 58 59 #include <linux/skbuff.h> 60 #include <linux/random.h> /* for get_random_bytes */ 61 #include <net/sctp/sctp.h> 62 #include <net/sctp/sm.h> 63 64 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 65 __u8 type, __u8 flags, int paylen, 66 gfp_t gfp); 67 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 68 __u8 flags, int paylen, gfp_t gfp); 69 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 70 __u8 type, __u8 flags, int paylen, 71 gfp_t gfp); 72 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, 73 const struct sctp_association *asoc, 74 const struct sctp_chunk *init_chunk, 75 int *cookie_len, 76 const __u8 *raw_addrs, int addrs_len); 77 static int sctp_process_param(struct sctp_association *asoc, 78 union sctp_params param, 79 const union sctp_addr *peer_addr, 80 gfp_t gfp); 81 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 82 const void *data); 83 static void *sctp_addto_chunk_fixed(struct sctp_chunk *, int len, 84 const void *data); 85 86 /* Control chunk destructor */ 87 static void sctp_control_release_owner(struct sk_buff *skb) 88 { 89 /*TODO: do memory release */ 90 } 91 92 static void sctp_control_set_owner_w(struct sctp_chunk *chunk) 93 { 94 struct sctp_association *asoc = chunk->asoc; 95 struct sk_buff *skb = chunk->skb; 96 97 /* TODO: properly account for control chunks. 98 * To do it right we'll need: 99 * 1) endpoint if association isn't known. 100 * 2) proper memory accounting. 101 * 102 * For now don't do anything for now. 103 */ 104 skb->sk = asoc ? asoc->base.sk : NULL; 105 skb->destructor = sctp_control_release_owner; 106 } 107 108 /* What was the inbound interface for this chunk? */ 109 int sctp_chunk_iif(const struct sctp_chunk *chunk) 110 { 111 struct sctp_af *af; 112 int iif = 0; 113 114 af = sctp_get_af_specific(ipver2af(ip_hdr(chunk->skb)->version)); 115 if (af) 116 iif = af->skb_iif(chunk->skb); 117 118 return iif; 119 } 120 121 /* RFC 2960 3.3.2 Initiation (INIT) (1) 122 * 123 * Note 2: The ECN capable field is reserved for future use of 124 * Explicit Congestion Notification. 125 */ 126 static const struct sctp_paramhdr ecap_param = { 127 SCTP_PARAM_ECN_CAPABLE, 128 cpu_to_be16(sizeof(struct sctp_paramhdr)), 129 }; 130 static const struct sctp_paramhdr prsctp_param = { 131 SCTP_PARAM_FWD_TSN_SUPPORT, 132 cpu_to_be16(sizeof(struct sctp_paramhdr)), 133 }; 134 135 /* A helper to initialize an op error inside a 136 * provided chunk, as most cause codes will be embedded inside an 137 * abort chunk. 138 */ 139 void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code, 140 size_t paylen) 141 { 142 sctp_errhdr_t err; 143 __u16 len; 144 145 /* Cause code constants are now defined in network order. */ 146 err.cause = cause_code; 147 len = sizeof(sctp_errhdr_t) + paylen; 148 err.length = htons(len); 149 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err); 150 } 151 152 /* A helper to initialize an op error inside a 153 * provided chunk, as most cause codes will be embedded inside an 154 * abort chunk. Differs from sctp_init_cause in that it won't oops 155 * if there isn't enough space in the op error chunk 156 */ 157 static int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code, 158 size_t paylen) 159 { 160 sctp_errhdr_t err; 161 __u16 len; 162 163 /* Cause code constants are now defined in network order. */ 164 err.cause = cause_code; 165 len = sizeof(sctp_errhdr_t) + paylen; 166 err.length = htons(len); 167 168 if (skb_tailroom(chunk->skb) < len) 169 return -ENOSPC; 170 chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk, 171 sizeof(sctp_errhdr_t), 172 &err); 173 return 0; 174 } 175 /* 3.3.2 Initiation (INIT) (1) 176 * 177 * This chunk is used to initiate a SCTP association between two 178 * endpoints. The format of the INIT chunk is shown below: 179 * 180 * 0 1 2 3 181 * 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 1 182 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 183 * | Type = 1 | Chunk Flags | Chunk Length | 184 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 185 * | Initiate Tag | 186 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 187 * | Advertised Receiver Window Credit (a_rwnd) | 188 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 189 * | Number of Outbound Streams | Number of Inbound Streams | 190 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 191 * | Initial TSN | 192 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 193 * \ \ 194 * / Optional/Variable-Length Parameters / 195 * \ \ 196 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 197 * 198 * 199 * The INIT chunk contains the following parameters. Unless otherwise 200 * noted, each parameter MUST only be included once in the INIT chunk. 201 * 202 * Fixed Parameters Status 203 * ---------------------------------------------- 204 * Initiate Tag Mandatory 205 * Advertised Receiver Window Credit Mandatory 206 * Number of Outbound Streams Mandatory 207 * Number of Inbound Streams Mandatory 208 * Initial TSN Mandatory 209 * 210 * Variable Parameters Status Type Value 211 * ------------------------------------------------------------- 212 * IPv4 Address (Note 1) Optional 5 213 * IPv6 Address (Note 1) Optional 6 214 * Cookie Preservative Optional 9 215 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000) 216 * Host Name Address (Note 3) Optional 11 217 * Supported Address Types (Note 4) Optional 12 218 */ 219 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc, 220 const struct sctp_bind_addr *bp, 221 gfp_t gfp, int vparam_len) 222 { 223 struct net *net = sock_net(asoc->base.sk); 224 struct sctp_endpoint *ep = asoc->ep; 225 sctp_inithdr_t init; 226 union sctp_params addrs; 227 size_t chunksize; 228 struct sctp_chunk *retval = NULL; 229 int num_types, addrs_len = 0; 230 struct sctp_sock *sp; 231 sctp_supported_addrs_param_t sat; 232 __be16 types[2]; 233 sctp_adaptation_ind_param_t aiparam; 234 sctp_supported_ext_param_t ext_param; 235 int num_ext = 0; 236 __u8 extensions[3]; 237 sctp_paramhdr_t *auth_chunks = NULL, 238 *auth_hmacs = NULL; 239 240 /* RFC 2960 3.3.2 Initiation (INIT) (1) 241 * 242 * Note 1: The INIT chunks can contain multiple addresses that 243 * can be IPv4 and/or IPv6 in any combination. 244 */ 245 retval = NULL; 246 247 /* Convert the provided bind address list to raw format. */ 248 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp); 249 250 init.init_tag = htonl(asoc->c.my_vtag); 251 init.a_rwnd = htonl(asoc->rwnd); 252 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 253 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 254 init.initial_tsn = htonl(asoc->c.initial_tsn); 255 256 /* How many address types are needed? */ 257 sp = sctp_sk(asoc->base.sk); 258 num_types = sp->pf->supported_addrs(sp, types); 259 260 chunksize = sizeof(init) + addrs_len; 261 chunksize += WORD_ROUND(SCTP_SAT_LEN(num_types)); 262 chunksize += sizeof(ecap_param); 263 264 if (net->sctp.prsctp_enable) 265 chunksize += sizeof(prsctp_param); 266 267 /* ADDIP: Section 4.2.7: 268 * An implementation supporting this extension [ADDIP] MUST list 269 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and 270 * INIT-ACK parameters. 271 */ 272 if (net->sctp.addip_enable) { 273 extensions[num_ext] = SCTP_CID_ASCONF; 274 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 275 num_ext += 2; 276 } 277 278 if (sp->adaptation_ind) 279 chunksize += sizeof(aiparam); 280 281 chunksize += vparam_len; 282 283 /* Account for AUTH related parameters */ 284 if (ep->auth_enable) { 285 /* Add random parameter length*/ 286 chunksize += sizeof(asoc->c.auth_random); 287 288 /* Add HMACS parameter length if any were defined */ 289 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs; 290 if (auth_hmacs->length) 291 chunksize += WORD_ROUND(ntohs(auth_hmacs->length)); 292 else 293 auth_hmacs = NULL; 294 295 /* Add CHUNKS parameter length */ 296 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks; 297 if (auth_chunks->length) 298 chunksize += WORD_ROUND(ntohs(auth_chunks->length)); 299 else 300 auth_chunks = NULL; 301 302 extensions[num_ext] = SCTP_CID_AUTH; 303 num_ext += 1; 304 } 305 306 /* If we have any extensions to report, account for that */ 307 if (num_ext) 308 chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) + 309 num_ext); 310 311 /* RFC 2960 3.3.2 Initiation (INIT) (1) 312 * 313 * Note 3: An INIT chunk MUST NOT contain more than one Host 314 * Name address parameter. Moreover, the sender of the INIT 315 * MUST NOT combine any other address types with the Host Name 316 * address in the INIT. The receiver of INIT MUST ignore any 317 * other address types if the Host Name address parameter is 318 * present in the received INIT chunk. 319 * 320 * PLEASE DO NOT FIXME [This version does not support Host Name.] 321 */ 322 323 retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp); 324 if (!retval) 325 goto nodata; 326 327 retval->subh.init_hdr = 328 sctp_addto_chunk(retval, sizeof(init), &init); 329 retval->param_hdr.v = 330 sctp_addto_chunk(retval, addrs_len, addrs.v); 331 332 /* RFC 2960 3.3.2 Initiation (INIT) (1) 333 * 334 * Note 4: This parameter, when present, specifies all the 335 * address types the sending endpoint can support. The absence 336 * of this parameter indicates that the sending endpoint can 337 * support any address type. 338 */ 339 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES; 340 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types)); 341 sctp_addto_chunk(retval, sizeof(sat), &sat); 342 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types); 343 344 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 345 346 /* Add the supported extensions parameter. Be nice and add this 347 * fist before addiding the parameters for the extensions themselves 348 */ 349 if (num_ext) { 350 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 351 ext_param.param_hdr.length = 352 htons(sizeof(sctp_supported_ext_param_t) + num_ext); 353 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t), 354 &ext_param); 355 sctp_addto_param(retval, num_ext, extensions); 356 } 357 358 if (net->sctp.prsctp_enable) 359 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 360 361 if (sp->adaptation_ind) { 362 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 363 aiparam.param_hdr.length = htons(sizeof(aiparam)); 364 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 365 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 366 } 367 368 /* Add SCTP-AUTH chunks to the parameter list */ 369 if (ep->auth_enable) { 370 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random), 371 asoc->c.auth_random); 372 if (auth_hmacs) 373 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 374 auth_hmacs); 375 if (auth_chunks) 376 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 377 auth_chunks); 378 } 379 nodata: 380 kfree(addrs.v); 381 return retval; 382 } 383 384 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc, 385 const struct sctp_chunk *chunk, 386 gfp_t gfp, int unkparam_len) 387 { 388 sctp_inithdr_t initack; 389 struct sctp_chunk *retval; 390 union sctp_params addrs; 391 struct sctp_sock *sp; 392 int addrs_len; 393 sctp_cookie_param_t *cookie; 394 int cookie_len; 395 size_t chunksize; 396 sctp_adaptation_ind_param_t aiparam; 397 sctp_supported_ext_param_t ext_param; 398 int num_ext = 0; 399 __u8 extensions[3]; 400 sctp_paramhdr_t *auth_chunks = NULL, 401 *auth_hmacs = NULL, 402 *auth_random = NULL; 403 404 retval = NULL; 405 406 /* Note: there may be no addresses to embed. */ 407 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp); 408 409 initack.init_tag = htonl(asoc->c.my_vtag); 410 initack.a_rwnd = htonl(asoc->rwnd); 411 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams); 412 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams); 413 initack.initial_tsn = htonl(asoc->c.initial_tsn); 414 415 /* FIXME: We really ought to build the cookie right 416 * into the packet instead of allocating more fresh memory. 417 */ 418 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len, 419 addrs.v, addrs_len); 420 if (!cookie) 421 goto nomem_cookie; 422 423 /* Calculate the total size of allocation, include the reserved 424 * space for reporting unknown parameters if it is specified. 425 */ 426 sp = sctp_sk(asoc->base.sk); 427 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len; 428 429 /* Tell peer that we'll do ECN only if peer advertised such cap. */ 430 if (asoc->peer.ecn_capable) 431 chunksize += sizeof(ecap_param); 432 433 if (asoc->peer.prsctp_capable) 434 chunksize += sizeof(prsctp_param); 435 436 if (asoc->peer.asconf_capable) { 437 extensions[num_ext] = SCTP_CID_ASCONF; 438 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK; 439 num_ext += 2; 440 } 441 442 if (sp->adaptation_ind) 443 chunksize += sizeof(aiparam); 444 445 if (asoc->peer.auth_capable) { 446 auth_random = (sctp_paramhdr_t *)asoc->c.auth_random; 447 chunksize += ntohs(auth_random->length); 448 449 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs; 450 if (auth_hmacs->length) 451 chunksize += WORD_ROUND(ntohs(auth_hmacs->length)); 452 else 453 auth_hmacs = NULL; 454 455 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks; 456 if (auth_chunks->length) 457 chunksize += WORD_ROUND(ntohs(auth_chunks->length)); 458 else 459 auth_chunks = NULL; 460 461 extensions[num_ext] = SCTP_CID_AUTH; 462 num_ext += 1; 463 } 464 465 if (num_ext) 466 chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) + 467 num_ext); 468 469 /* Now allocate and fill out the chunk. */ 470 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp); 471 if (!retval) 472 goto nomem_chunk; 473 474 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 475 * 476 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 477 * HEARTBEAT ACK, * etc.) to the same destination transport 478 * address from which it received the DATA or control chunk 479 * to which it is replying. 480 * 481 * [INIT ACK back to where the INIT came from.] 482 */ 483 retval->transport = chunk->transport; 484 485 retval->subh.init_hdr = 486 sctp_addto_chunk(retval, sizeof(initack), &initack); 487 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v); 488 sctp_addto_chunk(retval, cookie_len, cookie); 489 if (asoc->peer.ecn_capable) 490 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param); 491 if (num_ext) { 492 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT; 493 ext_param.param_hdr.length = 494 htons(sizeof(sctp_supported_ext_param_t) + num_ext); 495 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t), 496 &ext_param); 497 sctp_addto_param(retval, num_ext, extensions); 498 } 499 if (asoc->peer.prsctp_capable) 500 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param); 501 502 if (sp->adaptation_ind) { 503 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND; 504 aiparam.param_hdr.length = htons(sizeof(aiparam)); 505 aiparam.adaptation_ind = htonl(sp->adaptation_ind); 506 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam); 507 } 508 509 if (asoc->peer.auth_capable) { 510 sctp_addto_chunk(retval, ntohs(auth_random->length), 511 auth_random); 512 if (auth_hmacs) 513 sctp_addto_chunk(retval, ntohs(auth_hmacs->length), 514 auth_hmacs); 515 if (auth_chunks) 516 sctp_addto_chunk(retval, ntohs(auth_chunks->length), 517 auth_chunks); 518 } 519 520 /* We need to remove the const qualifier at this point. */ 521 retval->asoc = (struct sctp_association *) asoc; 522 523 nomem_chunk: 524 kfree(cookie); 525 nomem_cookie: 526 kfree(addrs.v); 527 return retval; 528 } 529 530 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10): 531 * 532 * This chunk is used only during the initialization of an association. 533 * It is sent by the initiator of an association to its peer to complete 534 * the initialization process. This chunk MUST precede any DATA chunk 535 * sent within the association, but MAY be bundled with one or more DATA 536 * chunks in the same packet. 537 * 538 * 0 1 2 3 539 * 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 1 540 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 541 * | Type = 10 |Chunk Flags | Length | 542 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 543 * / Cookie / 544 * \ \ 545 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 546 * 547 * Chunk Flags: 8 bit 548 * 549 * Set to zero on transmit and ignored on receipt. 550 * 551 * Length: 16 bits (unsigned integer) 552 * 553 * Set to the size of the chunk in bytes, including the 4 bytes of 554 * the chunk header and the size of the Cookie. 555 * 556 * Cookie: variable size 557 * 558 * This field must contain the exact cookie received in the 559 * State Cookie parameter from the previous INIT ACK. 560 * 561 * An implementation SHOULD make the cookie as small as possible 562 * to insure interoperability. 563 */ 564 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc, 565 const struct sctp_chunk *chunk) 566 { 567 struct sctp_chunk *retval; 568 void *cookie; 569 int cookie_len; 570 571 cookie = asoc->peer.cookie; 572 cookie_len = asoc->peer.cookie_len; 573 574 /* Build a cookie echo chunk. */ 575 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0, 576 cookie_len, GFP_ATOMIC); 577 if (!retval) 578 goto nodata; 579 retval->subh.cookie_hdr = 580 sctp_addto_chunk(retval, cookie_len, cookie); 581 582 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 583 * 584 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 585 * HEARTBEAT ACK, * etc.) to the same destination transport 586 * address from which it * received the DATA or control chunk 587 * to which it is replying. 588 * 589 * [COOKIE ECHO back to where the INIT ACK came from.] 590 */ 591 if (chunk) 592 retval->transport = chunk->transport; 593 594 nodata: 595 return retval; 596 } 597 598 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11): 599 * 600 * This chunk is used only during the initialization of an 601 * association. It is used to acknowledge the receipt of a COOKIE 602 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent 603 * within the association, but MAY be bundled with one or more DATA 604 * chunks or SACK chunk in the same SCTP packet. 605 * 606 * 0 1 2 3 607 * 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 1 608 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 609 * | Type = 11 |Chunk Flags | Length = 4 | 610 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 611 * 612 * Chunk Flags: 8 bits 613 * 614 * Set to zero on transmit and ignored on receipt. 615 */ 616 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc, 617 const struct sctp_chunk *chunk) 618 { 619 struct sctp_chunk *retval; 620 621 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC); 622 623 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 624 * 625 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 626 * HEARTBEAT ACK, * etc.) to the same destination transport 627 * address from which it * received the DATA or control chunk 628 * to which it is replying. 629 * 630 * [COOKIE ACK back to where the COOKIE ECHO came from.] 631 */ 632 if (retval && chunk) 633 retval->transport = chunk->transport; 634 635 return retval; 636 } 637 638 /* 639 * Appendix A: Explicit Congestion Notification: 640 * CWR: 641 * 642 * RFC 2481 details a specific bit for a sender to send in the header of 643 * its next outbound TCP segment to indicate to its peer that it has 644 * reduced its congestion window. This is termed the CWR bit. For 645 * SCTP the same indication is made by including the CWR chunk. 646 * This chunk contains one data element, i.e. the TSN number that 647 * was sent in the ECNE chunk. This element represents the lowest 648 * TSN number in the datagram that was originally marked with the 649 * CE bit. 650 * 651 * 0 1 2 3 652 * 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 1 653 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 654 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 | 655 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 656 * | Lowest TSN Number | 657 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 658 * 659 * Note: The CWR is considered a Control chunk. 660 */ 661 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc, 662 const __u32 lowest_tsn, 663 const struct sctp_chunk *chunk) 664 { 665 struct sctp_chunk *retval; 666 sctp_cwrhdr_t cwr; 667 668 cwr.lowest_tsn = htonl(lowest_tsn); 669 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0, 670 sizeof(sctp_cwrhdr_t), GFP_ATOMIC); 671 672 if (!retval) 673 goto nodata; 674 675 retval->subh.ecn_cwr_hdr = 676 sctp_addto_chunk(retval, sizeof(cwr), &cwr); 677 678 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 679 * 680 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 681 * HEARTBEAT ACK, * etc.) to the same destination transport 682 * address from which it * received the DATA or control chunk 683 * to which it is replying. 684 * 685 * [Report a reduced congestion window back to where the ECNE 686 * came from.] 687 */ 688 if (chunk) 689 retval->transport = chunk->transport; 690 691 nodata: 692 return retval; 693 } 694 695 /* Make an ECNE chunk. This is a congestion experienced report. */ 696 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc, 697 const __u32 lowest_tsn) 698 { 699 struct sctp_chunk *retval; 700 sctp_ecnehdr_t ecne; 701 702 ecne.lowest_tsn = htonl(lowest_tsn); 703 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0, 704 sizeof(sctp_ecnehdr_t), GFP_ATOMIC); 705 if (!retval) 706 goto nodata; 707 retval->subh.ecne_hdr = 708 sctp_addto_chunk(retval, sizeof(ecne), &ecne); 709 710 nodata: 711 return retval; 712 } 713 714 /* Make a DATA chunk for the given association from the provided 715 * parameters. However, do not populate the data payload. 716 */ 717 struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc, 718 const struct sctp_sndrcvinfo *sinfo, 719 int data_len, __u8 flags, __u16 ssn, 720 gfp_t gfp) 721 { 722 struct sctp_chunk *retval; 723 struct sctp_datahdr dp; 724 int chunk_len; 725 726 /* We assign the TSN as LATE as possible, not here when 727 * creating the chunk. 728 */ 729 dp.tsn = 0; 730 dp.stream = htons(sinfo->sinfo_stream); 731 dp.ppid = sinfo->sinfo_ppid; 732 733 /* Set the flags for an unordered send. */ 734 if (sinfo->sinfo_flags & SCTP_UNORDERED) { 735 flags |= SCTP_DATA_UNORDERED; 736 dp.ssn = 0; 737 } else 738 dp.ssn = htons(ssn); 739 740 chunk_len = sizeof(dp) + data_len; 741 retval = sctp_make_data(asoc, flags, chunk_len, gfp); 742 if (!retval) 743 goto nodata; 744 745 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp); 746 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo)); 747 748 nodata: 749 return retval; 750 } 751 752 /* Create a selective ackowledgement (SACK) for the given 753 * association. This reports on which TSN's we've seen to date, 754 * including duplicates and gaps. 755 */ 756 struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc) 757 { 758 struct sctp_chunk *retval; 759 struct sctp_sackhdr sack; 760 int len; 761 __u32 ctsn; 762 __u16 num_gabs, num_dup_tsns; 763 struct sctp_association *aptr = (struct sctp_association *)asoc; 764 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; 765 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS]; 766 struct sctp_transport *trans; 767 768 memset(gabs, 0, sizeof(gabs)); 769 ctsn = sctp_tsnmap_get_ctsn(map); 770 771 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn); 772 773 /* How much room is needed in the chunk? */ 774 num_gabs = sctp_tsnmap_num_gabs(map, gabs); 775 num_dup_tsns = sctp_tsnmap_num_dups(map); 776 777 /* Initialize the SACK header. */ 778 sack.cum_tsn_ack = htonl(ctsn); 779 sack.a_rwnd = htonl(asoc->a_rwnd); 780 sack.num_gap_ack_blocks = htons(num_gabs); 781 sack.num_dup_tsns = htons(num_dup_tsns); 782 783 len = sizeof(sack) 784 + sizeof(struct sctp_gap_ack_block) * num_gabs 785 + sizeof(__u32) * num_dup_tsns; 786 787 /* Create the chunk. */ 788 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC); 789 if (!retval) 790 goto nodata; 791 792 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 793 * 794 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 795 * HEARTBEAT ACK, etc.) to the same destination transport 796 * address from which it received the DATA or control chunk to 797 * which it is replying. This rule should also be followed if 798 * the endpoint is bundling DATA chunks together with the 799 * reply chunk. 800 * 801 * However, when acknowledging multiple DATA chunks received 802 * in packets from different source addresses in a single 803 * SACK, the SACK chunk may be transmitted to one of the 804 * destination transport addresses from which the DATA or 805 * control chunks being acknowledged were received. 806 * 807 * [BUG: We do not implement the following paragraph. 808 * Perhaps we should remember the last transport we used for a 809 * SACK and avoid that (if possible) if we have seen any 810 * duplicates. --piggy] 811 * 812 * When a receiver of a duplicate DATA chunk sends a SACK to a 813 * multi- homed endpoint it MAY be beneficial to vary the 814 * destination address and not use the source address of the 815 * DATA chunk. The reason being that receiving a duplicate 816 * from a multi-homed endpoint might indicate that the return 817 * path (as specified in the source address of the DATA chunk) 818 * for the SACK is broken. 819 * 820 * [Send to the address from which we last received a DATA chunk.] 821 */ 822 retval->transport = asoc->peer.last_data_from; 823 824 retval->subh.sack_hdr = 825 sctp_addto_chunk(retval, sizeof(sack), &sack); 826 827 /* Add the gap ack block information. */ 828 if (num_gabs) 829 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs, 830 gabs); 831 832 /* Add the duplicate TSN information. */ 833 if (num_dup_tsns) { 834 aptr->stats.idupchunks += num_dup_tsns; 835 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns, 836 sctp_tsnmap_get_dups(map)); 837 } 838 /* Once we have a sack generated, check to see what our sack 839 * generation is, if its 0, reset the transports to 0, and reset 840 * the association generation to 1 841 * 842 * The idea is that zero is never used as a valid generation for the 843 * association so no transport will match after a wrap event like this, 844 * Until the next sack 845 */ 846 if (++aptr->peer.sack_generation == 0) { 847 list_for_each_entry(trans, &asoc->peer.transport_addr_list, 848 transports) 849 trans->sack_generation = 0; 850 aptr->peer.sack_generation = 1; 851 } 852 nodata: 853 return retval; 854 } 855 856 /* Make a SHUTDOWN chunk. */ 857 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc, 858 const struct sctp_chunk *chunk) 859 { 860 struct sctp_chunk *retval; 861 sctp_shutdownhdr_t shut; 862 __u32 ctsn; 863 864 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 865 shut.cum_tsn_ack = htonl(ctsn); 866 867 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0, 868 sizeof(sctp_shutdownhdr_t), GFP_ATOMIC); 869 if (!retval) 870 goto nodata; 871 872 retval->subh.shutdown_hdr = 873 sctp_addto_chunk(retval, sizeof(shut), &shut); 874 875 if (chunk) 876 retval->transport = chunk->transport; 877 nodata: 878 return retval; 879 } 880 881 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc, 882 const struct sctp_chunk *chunk) 883 { 884 struct sctp_chunk *retval; 885 886 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0, 887 GFP_ATOMIC); 888 889 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 890 * 891 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 892 * HEARTBEAT ACK, * etc.) to the same destination transport 893 * address from which it * received the DATA or control chunk 894 * to which it is replying. 895 * 896 * [ACK back to where the SHUTDOWN came from.] 897 */ 898 if (retval && chunk) 899 retval->transport = chunk->transport; 900 901 return retval; 902 } 903 904 struct sctp_chunk *sctp_make_shutdown_complete( 905 const struct sctp_association *asoc, 906 const struct sctp_chunk *chunk) 907 { 908 struct sctp_chunk *retval; 909 __u8 flags = 0; 910 911 /* Set the T-bit if we have no association (vtag will be 912 * reflected) 913 */ 914 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T; 915 916 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 917 0, GFP_ATOMIC); 918 919 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 920 * 921 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 922 * HEARTBEAT ACK, * etc.) to the same destination transport 923 * address from which it * received the DATA or control chunk 924 * to which it is replying. 925 * 926 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK 927 * came from.] 928 */ 929 if (retval && chunk) 930 retval->transport = chunk->transport; 931 932 return retval; 933 } 934 935 /* Create an ABORT. Note that we set the T bit if we have no 936 * association, except when responding to an INIT (sctpimpguide 2.41). 937 */ 938 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc, 939 const struct sctp_chunk *chunk, 940 const size_t hint) 941 { 942 struct sctp_chunk *retval; 943 __u8 flags = 0; 944 945 /* Set the T-bit if we have no association and 'chunk' is not 946 * an INIT (vtag will be reflected). 947 */ 948 if (!asoc) { 949 if (chunk && chunk->chunk_hdr && 950 chunk->chunk_hdr->type == SCTP_CID_INIT) 951 flags = 0; 952 else 953 flags = SCTP_CHUNK_FLAG_T; 954 } 955 956 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint, 957 GFP_ATOMIC); 958 959 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 960 * 961 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 962 * HEARTBEAT ACK, * etc.) to the same destination transport 963 * address from which it * received the DATA or control chunk 964 * to which it is replying. 965 * 966 * [ABORT back to where the offender came from.] 967 */ 968 if (retval && chunk) 969 retval->transport = chunk->transport; 970 971 return retval; 972 } 973 974 /* Helper to create ABORT with a NO_USER_DATA error. */ 975 struct sctp_chunk *sctp_make_abort_no_data( 976 const struct sctp_association *asoc, 977 const struct sctp_chunk *chunk, __u32 tsn) 978 { 979 struct sctp_chunk *retval; 980 __be32 payload; 981 982 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) 983 + sizeof(tsn)); 984 985 if (!retval) 986 goto no_mem; 987 988 /* Put the tsn back into network byte order. */ 989 payload = htonl(tsn); 990 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload)); 991 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload); 992 993 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 994 * 995 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 996 * HEARTBEAT ACK, * etc.) to the same destination transport 997 * address from which it * received the DATA or control chunk 998 * to which it is replying. 999 * 1000 * [ABORT back to where the offender came from.] 1001 */ 1002 if (chunk) 1003 retval->transport = chunk->transport; 1004 1005 no_mem: 1006 return retval; 1007 } 1008 1009 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */ 1010 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc, 1011 struct msghdr *msg, 1012 size_t paylen) 1013 { 1014 struct sctp_chunk *retval; 1015 void *payload = NULL; 1016 int err; 1017 1018 retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen); 1019 if (!retval) 1020 goto err_chunk; 1021 1022 if (paylen) { 1023 /* Put the msg_iov together into payload. */ 1024 payload = kmalloc(paylen, GFP_KERNEL); 1025 if (!payload) 1026 goto err_payload; 1027 1028 err = memcpy_from_msg(payload, msg, paylen); 1029 if (err < 0) 1030 goto err_copy; 1031 } 1032 1033 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen); 1034 sctp_addto_chunk(retval, paylen, payload); 1035 1036 if (paylen) 1037 kfree(payload); 1038 1039 return retval; 1040 1041 err_copy: 1042 kfree(payload); 1043 err_payload: 1044 sctp_chunk_free(retval); 1045 retval = NULL; 1046 err_chunk: 1047 return retval; 1048 } 1049 1050 /* Append bytes to the end of a parameter. Will panic if chunk is not big 1051 * enough. 1052 */ 1053 static void *sctp_addto_param(struct sctp_chunk *chunk, int len, 1054 const void *data) 1055 { 1056 void *target; 1057 int chunklen = ntohs(chunk->chunk_hdr->length); 1058 1059 target = skb_put(chunk->skb, len); 1060 1061 if (data) 1062 memcpy(target, data, len); 1063 else 1064 memset(target, 0, len); 1065 1066 /* Adjust the chunk length field. */ 1067 chunk->chunk_hdr->length = htons(chunklen + len); 1068 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1069 1070 return target; 1071 } 1072 1073 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */ 1074 struct sctp_chunk *sctp_make_abort_violation( 1075 const struct sctp_association *asoc, 1076 const struct sctp_chunk *chunk, 1077 const __u8 *payload, 1078 const size_t paylen) 1079 { 1080 struct sctp_chunk *retval; 1081 struct sctp_paramhdr phdr; 1082 1083 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen 1084 + sizeof(sctp_paramhdr_t)); 1085 if (!retval) 1086 goto end; 1087 1088 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen 1089 + sizeof(sctp_paramhdr_t)); 1090 1091 phdr.type = htons(chunk->chunk_hdr->type); 1092 phdr.length = chunk->chunk_hdr->length; 1093 sctp_addto_chunk(retval, paylen, payload); 1094 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr); 1095 1096 end: 1097 return retval; 1098 } 1099 1100 struct sctp_chunk *sctp_make_violation_paramlen( 1101 const struct sctp_association *asoc, 1102 const struct sctp_chunk *chunk, 1103 struct sctp_paramhdr *param) 1104 { 1105 struct sctp_chunk *retval; 1106 static const char error[] = "The following parameter had invalid length:"; 1107 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t) + 1108 sizeof(sctp_paramhdr_t); 1109 1110 retval = sctp_make_abort(asoc, chunk, payload_len); 1111 if (!retval) 1112 goto nodata; 1113 1114 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, 1115 sizeof(error) + sizeof(sctp_paramhdr_t)); 1116 sctp_addto_chunk(retval, sizeof(error), error); 1117 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), param); 1118 1119 nodata: 1120 return retval; 1121 } 1122 1123 struct sctp_chunk *sctp_make_violation_max_retrans( 1124 const struct sctp_association *asoc, 1125 const struct sctp_chunk *chunk) 1126 { 1127 struct sctp_chunk *retval; 1128 static const char error[] = "Association exceeded its max_retans count"; 1129 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t); 1130 1131 retval = sctp_make_abort(asoc, chunk, payload_len); 1132 if (!retval) 1133 goto nodata; 1134 1135 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error)); 1136 sctp_addto_chunk(retval, sizeof(error), error); 1137 1138 nodata: 1139 return retval; 1140 } 1141 1142 /* Make a HEARTBEAT chunk. */ 1143 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc, 1144 const struct sctp_transport *transport) 1145 { 1146 struct sctp_chunk *retval; 1147 sctp_sender_hb_info_t hbinfo; 1148 1149 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, 1150 sizeof(hbinfo), GFP_ATOMIC); 1151 1152 if (!retval) 1153 goto nodata; 1154 1155 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; 1156 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t)); 1157 hbinfo.daddr = transport->ipaddr; 1158 hbinfo.sent_at = jiffies; 1159 hbinfo.hb_nonce = transport->hb_nonce; 1160 1161 /* Cast away the 'const', as this is just telling the chunk 1162 * what transport it belongs to. 1163 */ 1164 retval->transport = (struct sctp_transport *) transport; 1165 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo), 1166 &hbinfo); 1167 1168 nodata: 1169 return retval; 1170 } 1171 1172 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc, 1173 const struct sctp_chunk *chunk, 1174 const void *payload, const size_t paylen) 1175 { 1176 struct sctp_chunk *retval; 1177 1178 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen, 1179 GFP_ATOMIC); 1180 if (!retval) 1181 goto nodata; 1182 1183 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload); 1184 1185 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1186 * 1187 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1188 * HEARTBEAT ACK, * etc.) to the same destination transport 1189 * address from which it * received the DATA or control chunk 1190 * to which it is replying. 1191 * 1192 * [HBACK back to where the HEARTBEAT came from.] 1193 */ 1194 if (chunk) 1195 retval->transport = chunk->transport; 1196 1197 nodata: 1198 return retval; 1199 } 1200 1201 /* Create an Operation Error chunk with the specified space reserved. 1202 * This routine can be used for containing multiple causes in the chunk. 1203 */ 1204 static struct sctp_chunk *sctp_make_op_error_space( 1205 const struct sctp_association *asoc, 1206 const struct sctp_chunk *chunk, 1207 size_t size) 1208 { 1209 struct sctp_chunk *retval; 1210 1211 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0, 1212 sizeof(sctp_errhdr_t) + size, GFP_ATOMIC); 1213 if (!retval) 1214 goto nodata; 1215 1216 /* RFC 2960 6.4 Multi-homed SCTP Endpoints 1217 * 1218 * An endpoint SHOULD transmit reply chunks (e.g., SACK, 1219 * HEARTBEAT ACK, etc.) to the same destination transport 1220 * address from which it received the DATA or control chunk 1221 * to which it is replying. 1222 * 1223 */ 1224 if (chunk) 1225 retval->transport = chunk->transport; 1226 1227 nodata: 1228 return retval; 1229 } 1230 1231 /* Create an Operation Error chunk of a fixed size, 1232 * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) 1233 * This is a helper function to allocate an error chunk for 1234 * for those invalid parameter codes in which we may not want 1235 * to report all the errors, if the incoming chunk is large 1236 */ 1237 static inline struct sctp_chunk *sctp_make_op_error_fixed( 1238 const struct sctp_association *asoc, 1239 const struct sctp_chunk *chunk) 1240 { 1241 size_t size = asoc ? asoc->pathmtu : 0; 1242 1243 if (!size) 1244 size = SCTP_DEFAULT_MAXSEGMENT; 1245 1246 return sctp_make_op_error_space(asoc, chunk, size); 1247 } 1248 1249 /* Create an Operation Error chunk. */ 1250 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc, 1251 const struct sctp_chunk *chunk, 1252 __be16 cause_code, const void *payload, 1253 size_t paylen, size_t reserve_tail) 1254 { 1255 struct sctp_chunk *retval; 1256 1257 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail); 1258 if (!retval) 1259 goto nodata; 1260 1261 sctp_init_cause(retval, cause_code, paylen + reserve_tail); 1262 sctp_addto_chunk(retval, paylen, payload); 1263 if (reserve_tail) 1264 sctp_addto_param(retval, reserve_tail, NULL); 1265 1266 nodata: 1267 return retval; 1268 } 1269 1270 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc) 1271 { 1272 struct sctp_chunk *retval; 1273 struct sctp_hmac *hmac_desc; 1274 struct sctp_authhdr auth_hdr; 1275 __u8 *hmac; 1276 1277 /* Get the first hmac that the peer told us to use */ 1278 hmac_desc = sctp_auth_asoc_get_hmac(asoc); 1279 if (unlikely(!hmac_desc)) 1280 return NULL; 1281 1282 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0, 1283 hmac_desc->hmac_len + sizeof(sctp_authhdr_t), 1284 GFP_ATOMIC); 1285 if (!retval) 1286 return NULL; 1287 1288 auth_hdr.hmac_id = htons(hmac_desc->hmac_id); 1289 auth_hdr.shkey_id = htons(asoc->active_key_id); 1290 1291 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t), 1292 &auth_hdr); 1293 1294 hmac = skb_put(retval->skb, hmac_desc->hmac_len); 1295 memset(hmac, 0, hmac_desc->hmac_len); 1296 1297 /* Adjust the chunk header to include the empty MAC */ 1298 retval->chunk_hdr->length = 1299 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len); 1300 retval->chunk_end = skb_tail_pointer(retval->skb); 1301 1302 return retval; 1303 } 1304 1305 1306 /******************************************************************** 1307 * 2nd Level Abstractions 1308 ********************************************************************/ 1309 1310 /* Turn an skb into a chunk. 1311 * FIXME: Eventually move the structure directly inside the skb->cb[]. 1312 * 1313 * sctpimpguide-05.txt Section 2.8.2 1314 * M1) Each time a new DATA chunk is transmitted 1315 * set the 'TSN.Missing.Report' count for that TSN to 0. The 1316 * 'TSN.Missing.Report' count will be used to determine missing chunks 1317 * and when to fast retransmit. 1318 * 1319 */ 1320 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb, 1321 const struct sctp_association *asoc, 1322 struct sock *sk, gfp_t gfp) 1323 { 1324 struct sctp_chunk *retval; 1325 1326 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp); 1327 1328 if (!retval) 1329 goto nodata; 1330 if (!sk) 1331 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb); 1332 1333 INIT_LIST_HEAD(&retval->list); 1334 retval->skb = skb; 1335 retval->asoc = (struct sctp_association *)asoc; 1336 retval->singleton = 1; 1337 1338 retval->fast_retransmit = SCTP_CAN_FRTX; 1339 1340 /* Polish the bead hole. */ 1341 INIT_LIST_HEAD(&retval->transmitted_list); 1342 INIT_LIST_HEAD(&retval->frag_list); 1343 SCTP_DBG_OBJCNT_INC(chunk); 1344 atomic_set(&retval->refcnt, 1); 1345 1346 nodata: 1347 return retval; 1348 } 1349 1350 /* Set chunk->source and dest based on the IP header in chunk->skb. */ 1351 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src, 1352 union sctp_addr *dest) 1353 { 1354 memcpy(&chunk->source, src, sizeof(union sctp_addr)); 1355 memcpy(&chunk->dest, dest, sizeof(union sctp_addr)); 1356 } 1357 1358 /* Extract the source address from a chunk. */ 1359 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk) 1360 { 1361 /* If we have a known transport, use that. */ 1362 if (chunk->transport) { 1363 return &chunk->transport->ipaddr; 1364 } else { 1365 /* Otherwise, extract it from the IP header. */ 1366 return &chunk->source; 1367 } 1368 } 1369 1370 /* Create a new chunk, setting the type and flags headers from the 1371 * arguments, reserving enough space for a 'paylen' byte payload. 1372 */ 1373 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc, 1374 __u8 type, __u8 flags, int paylen, 1375 gfp_t gfp) 1376 { 1377 struct sctp_chunk *retval; 1378 sctp_chunkhdr_t *chunk_hdr; 1379 struct sk_buff *skb; 1380 struct sock *sk; 1381 1382 /* No need to allocate LL here, as this is only a chunk. */ 1383 skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen), gfp); 1384 if (!skb) 1385 goto nodata; 1386 1387 /* Make room for the chunk header. */ 1388 chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t)); 1389 chunk_hdr->type = type; 1390 chunk_hdr->flags = flags; 1391 chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t)); 1392 1393 sk = asoc ? asoc->base.sk : NULL; 1394 retval = sctp_chunkify(skb, asoc, sk, gfp); 1395 if (!retval) { 1396 kfree_skb(skb); 1397 goto nodata; 1398 } 1399 1400 retval->chunk_hdr = chunk_hdr; 1401 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr); 1402 1403 /* Determine if the chunk needs to be authenticated */ 1404 if (sctp_auth_send_cid(type, asoc)) 1405 retval->auth = 1; 1406 1407 return retval; 1408 nodata: 1409 return NULL; 1410 } 1411 1412 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc, 1413 __u8 flags, int paylen, gfp_t gfp) 1414 { 1415 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp); 1416 } 1417 1418 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc, 1419 __u8 type, __u8 flags, int paylen, 1420 gfp_t gfp) 1421 { 1422 struct sctp_chunk *chunk; 1423 1424 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp); 1425 if (chunk) 1426 sctp_control_set_owner_w(chunk); 1427 1428 return chunk; 1429 } 1430 1431 /* Release the memory occupied by a chunk. */ 1432 static void sctp_chunk_destroy(struct sctp_chunk *chunk) 1433 { 1434 BUG_ON(!list_empty(&chunk->list)); 1435 list_del_init(&chunk->transmitted_list); 1436 1437 consume_skb(chunk->skb); 1438 consume_skb(chunk->auth_chunk); 1439 1440 SCTP_DBG_OBJCNT_DEC(chunk); 1441 kmem_cache_free(sctp_chunk_cachep, chunk); 1442 } 1443 1444 /* Possibly, free the chunk. */ 1445 void sctp_chunk_free(struct sctp_chunk *chunk) 1446 { 1447 /* Release our reference on the message tracker. */ 1448 if (chunk->msg) 1449 sctp_datamsg_put(chunk->msg); 1450 1451 sctp_chunk_put(chunk); 1452 } 1453 1454 /* Grab a reference to the chunk. */ 1455 void sctp_chunk_hold(struct sctp_chunk *ch) 1456 { 1457 atomic_inc(&ch->refcnt); 1458 } 1459 1460 /* Release a reference to the chunk. */ 1461 void sctp_chunk_put(struct sctp_chunk *ch) 1462 { 1463 if (atomic_dec_and_test(&ch->refcnt)) 1464 sctp_chunk_destroy(ch); 1465 } 1466 1467 /* Append bytes to the end of a chunk. Will panic if chunk is not big 1468 * enough. 1469 */ 1470 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data) 1471 { 1472 void *target; 1473 void *padding; 1474 int chunklen = ntohs(chunk->chunk_hdr->length); 1475 int padlen = WORD_ROUND(chunklen) - chunklen; 1476 1477 padding = skb_put(chunk->skb, padlen); 1478 target = skb_put(chunk->skb, len); 1479 1480 memset(padding, 0, padlen); 1481 memcpy(target, data, len); 1482 1483 /* Adjust the chunk length field. */ 1484 chunk->chunk_hdr->length = htons(chunklen + padlen + len); 1485 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1486 1487 return target; 1488 } 1489 1490 /* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient 1491 * space in the chunk 1492 */ 1493 static void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk, 1494 int len, const void *data) 1495 { 1496 if (skb_tailroom(chunk->skb) >= len) 1497 return sctp_addto_chunk(chunk, len, data); 1498 else 1499 return NULL; 1500 } 1501 1502 /* Append bytes from user space to the end of a chunk. Will panic if 1503 * chunk is not big enough. 1504 * Returns a kernel err value. 1505 */ 1506 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len, 1507 struct iov_iter *from) 1508 { 1509 void *target; 1510 ssize_t copied; 1511 1512 /* Make room in chunk for data. */ 1513 target = skb_put(chunk->skb, len); 1514 1515 /* Copy data (whole iovec) into chunk */ 1516 copied = copy_from_iter(target, len, from); 1517 if (copied != len) 1518 return -EFAULT; 1519 1520 /* Adjust the chunk length field. */ 1521 chunk->chunk_hdr->length = 1522 htons(ntohs(chunk->chunk_hdr->length) + len); 1523 chunk->chunk_end = skb_tail_pointer(chunk->skb); 1524 1525 return 0; 1526 } 1527 1528 /* Helper function to assign a TSN if needed. This assumes that both 1529 * the data_hdr and association have already been assigned. 1530 */ 1531 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk) 1532 { 1533 struct sctp_datamsg *msg; 1534 struct sctp_chunk *lchunk; 1535 struct sctp_stream *stream; 1536 __u16 ssn; 1537 __u16 sid; 1538 1539 if (chunk->has_ssn) 1540 return; 1541 1542 /* All fragments will be on the same stream */ 1543 sid = ntohs(chunk->subh.data_hdr->stream); 1544 stream = &chunk->asoc->ssnmap->out; 1545 1546 /* Now assign the sequence number to the entire message. 1547 * All fragments must have the same stream sequence number. 1548 */ 1549 msg = chunk->msg; 1550 list_for_each_entry(lchunk, &msg->chunks, frag_list) { 1551 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) { 1552 ssn = 0; 1553 } else { 1554 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG) 1555 ssn = sctp_ssn_next(stream, sid); 1556 else 1557 ssn = sctp_ssn_peek(stream, sid); 1558 } 1559 1560 lchunk->subh.data_hdr->ssn = htons(ssn); 1561 lchunk->has_ssn = 1; 1562 } 1563 } 1564 1565 /* Helper function to assign a TSN if needed. This assumes that both 1566 * the data_hdr and association have already been assigned. 1567 */ 1568 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk) 1569 { 1570 if (!chunk->has_tsn) { 1571 /* This is the last possible instant to 1572 * assign a TSN. 1573 */ 1574 chunk->subh.data_hdr->tsn = 1575 htonl(sctp_association_get_next_tsn(chunk->asoc)); 1576 chunk->has_tsn = 1; 1577 } 1578 } 1579 1580 /* Create a CLOSED association to use with an incoming packet. */ 1581 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep, 1582 struct sctp_chunk *chunk, 1583 gfp_t gfp) 1584 { 1585 struct sctp_association *asoc; 1586 struct sk_buff *skb; 1587 sctp_scope_t scope; 1588 struct sctp_af *af; 1589 1590 /* Create the bare association. */ 1591 scope = sctp_scope(sctp_source(chunk)); 1592 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp); 1593 if (!asoc) 1594 goto nodata; 1595 asoc->temp = 1; 1596 skb = chunk->skb; 1597 /* Create an entry for the source address of the packet. */ 1598 af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version)); 1599 if (unlikely(!af)) 1600 goto fail; 1601 af->from_skb(&asoc->c.peer_addr, skb, 1); 1602 nodata: 1603 return asoc; 1604 1605 fail: 1606 sctp_association_free(asoc); 1607 return NULL; 1608 } 1609 1610 /* Build a cookie representing asoc. 1611 * This INCLUDES the param header needed to put the cookie in the INIT ACK. 1612 */ 1613 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep, 1614 const struct sctp_association *asoc, 1615 const struct sctp_chunk *init_chunk, 1616 int *cookie_len, 1617 const __u8 *raw_addrs, int addrs_len) 1618 { 1619 sctp_cookie_param_t *retval; 1620 struct sctp_signed_cookie *cookie; 1621 int headersize, bodysize; 1622 1623 /* Header size is static data prior to the actual cookie, including 1624 * any padding. 1625 */ 1626 headersize = sizeof(sctp_paramhdr_t) + 1627 (sizeof(struct sctp_signed_cookie) - 1628 sizeof(struct sctp_cookie)); 1629 bodysize = sizeof(struct sctp_cookie) 1630 + ntohs(init_chunk->chunk_hdr->length) + addrs_len; 1631 1632 /* Pad out the cookie to a multiple to make the signature 1633 * functions simpler to write. 1634 */ 1635 if (bodysize % SCTP_COOKIE_MULTIPLE) 1636 bodysize += SCTP_COOKIE_MULTIPLE 1637 - (bodysize % SCTP_COOKIE_MULTIPLE); 1638 *cookie_len = headersize + bodysize; 1639 1640 /* Clear this memory since we are sending this data structure 1641 * out on the network. 1642 */ 1643 retval = kzalloc(*cookie_len, GFP_ATOMIC); 1644 if (!retval) 1645 goto nodata; 1646 1647 cookie = (struct sctp_signed_cookie *) retval->body; 1648 1649 /* Set up the parameter header. */ 1650 retval->p.type = SCTP_PARAM_STATE_COOKIE; 1651 retval->p.length = htons(*cookie_len); 1652 1653 /* Copy the cookie part of the association itself. */ 1654 cookie->c = asoc->c; 1655 /* Save the raw address list length in the cookie. */ 1656 cookie->c.raw_addr_list_len = addrs_len; 1657 1658 /* Remember PR-SCTP capability. */ 1659 cookie->c.prsctp_capable = asoc->peer.prsctp_capable; 1660 1661 /* Save adaptation indication in the cookie. */ 1662 cookie->c.adaptation_ind = asoc->peer.adaptation_ind; 1663 1664 /* Set an expiration time for the cookie. */ 1665 cookie->c.expiration = ktime_add(asoc->cookie_life, 1666 ktime_get_real()); 1667 1668 /* Copy the peer's init packet. */ 1669 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr, 1670 ntohs(init_chunk->chunk_hdr->length)); 1671 1672 /* Copy the raw local address list of the association. */ 1673 memcpy((__u8 *)&cookie->c.peer_init[0] + 1674 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len); 1675 1676 if (sctp_sk(ep->base.sk)->hmac) { 1677 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac); 1678 int err; 1679 1680 /* Sign the message. */ 1681 desc->tfm = sctp_sk(ep->base.sk)->hmac; 1682 desc->flags = 0; 1683 1684 err = crypto_shash_setkey(desc->tfm, ep->secret_key, 1685 sizeof(ep->secret_key)) ?: 1686 crypto_shash_digest(desc, (u8 *)&cookie->c, bodysize, 1687 cookie->signature); 1688 shash_desc_zero(desc); 1689 if (err) 1690 goto free_cookie; 1691 } 1692 1693 return retval; 1694 1695 free_cookie: 1696 kfree(retval); 1697 nodata: 1698 *cookie_len = 0; 1699 return NULL; 1700 } 1701 1702 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */ 1703 struct sctp_association *sctp_unpack_cookie( 1704 const struct sctp_endpoint *ep, 1705 const struct sctp_association *asoc, 1706 struct sctp_chunk *chunk, gfp_t gfp, 1707 int *error, struct sctp_chunk **errp) 1708 { 1709 struct sctp_association *retval = NULL; 1710 struct sctp_signed_cookie *cookie; 1711 struct sctp_cookie *bear_cookie; 1712 int headersize, bodysize, fixed_size; 1713 __u8 *digest = ep->digest; 1714 unsigned int len; 1715 sctp_scope_t scope; 1716 struct sk_buff *skb = chunk->skb; 1717 ktime_t kt; 1718 1719 /* Header size is static data prior to the actual cookie, including 1720 * any padding. 1721 */ 1722 headersize = sizeof(sctp_chunkhdr_t) + 1723 (sizeof(struct sctp_signed_cookie) - 1724 sizeof(struct sctp_cookie)); 1725 bodysize = ntohs(chunk->chunk_hdr->length) - headersize; 1726 fixed_size = headersize + sizeof(struct sctp_cookie); 1727 1728 /* Verify that the chunk looks like it even has a cookie. 1729 * There must be enough room for our cookie and our peer's 1730 * INIT chunk. 1731 */ 1732 len = ntohs(chunk->chunk_hdr->length); 1733 if (len < fixed_size + sizeof(struct sctp_chunkhdr)) 1734 goto malformed; 1735 1736 /* Verify that the cookie has been padded out. */ 1737 if (bodysize % SCTP_COOKIE_MULTIPLE) 1738 goto malformed; 1739 1740 /* Process the cookie. */ 1741 cookie = chunk->subh.cookie_hdr; 1742 bear_cookie = &cookie->c; 1743 1744 if (!sctp_sk(ep->base.sk)->hmac) 1745 goto no_hmac; 1746 1747 /* Check the signature. */ 1748 { 1749 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac); 1750 int err; 1751 1752 desc->tfm = sctp_sk(ep->base.sk)->hmac; 1753 desc->flags = 0; 1754 1755 err = crypto_shash_setkey(desc->tfm, ep->secret_key, 1756 sizeof(ep->secret_key)) ?: 1757 crypto_shash_digest(desc, (u8 *)bear_cookie, bodysize, 1758 digest); 1759 shash_desc_zero(desc); 1760 1761 if (err) { 1762 *error = -SCTP_IERROR_NOMEM; 1763 goto fail; 1764 } 1765 } 1766 1767 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) { 1768 *error = -SCTP_IERROR_BAD_SIG; 1769 goto fail; 1770 } 1771 1772 no_hmac: 1773 /* IG Section 2.35.2: 1774 * 3) Compare the port numbers and the verification tag contained 1775 * within the COOKIE ECHO chunk to the actual port numbers and the 1776 * verification tag within the SCTP common header of the received 1777 * packet. If these values do not match the packet MUST be silently 1778 * discarded, 1779 */ 1780 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) { 1781 *error = -SCTP_IERROR_BAD_TAG; 1782 goto fail; 1783 } 1784 1785 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port || 1786 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) { 1787 *error = -SCTP_IERROR_BAD_PORTS; 1788 goto fail; 1789 } 1790 1791 /* Check to see if the cookie is stale. If there is already 1792 * an association, there is no need to check cookie's expiration 1793 * for init collision case of lost COOKIE ACK. 1794 * If skb has been timestamped, then use the stamp, otherwise 1795 * use current time. This introduces a small possibility that 1796 * that a cookie may be considered expired, but his would only slow 1797 * down the new association establishment instead of every packet. 1798 */ 1799 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP)) 1800 kt = skb_get_ktime(skb); 1801 else 1802 kt = ktime_get_real(); 1803 1804 if (!asoc && ktime_before(bear_cookie->expiration, kt)) { 1805 /* 1806 * Section 3.3.10.3 Stale Cookie Error (3) 1807 * 1808 * Cause of error 1809 * --------------- 1810 * Stale Cookie Error: Indicates the receipt of a valid State 1811 * Cookie that has expired. 1812 */ 1813 len = ntohs(chunk->chunk_hdr->length); 1814 *errp = sctp_make_op_error_space(asoc, chunk, len); 1815 if (*errp) { 1816 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration)); 1817 __be32 n = htonl(usecs); 1818 1819 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE, 1820 sizeof(n)); 1821 sctp_addto_chunk(*errp, sizeof(n), &n); 1822 *error = -SCTP_IERROR_STALE_COOKIE; 1823 } else 1824 *error = -SCTP_IERROR_NOMEM; 1825 1826 goto fail; 1827 } 1828 1829 /* Make a new base association. */ 1830 scope = sctp_scope(sctp_source(chunk)); 1831 retval = sctp_association_new(ep, ep->base.sk, scope, gfp); 1832 if (!retval) { 1833 *error = -SCTP_IERROR_NOMEM; 1834 goto fail; 1835 } 1836 1837 /* Set up our peer's port number. */ 1838 retval->peer.port = ntohs(chunk->sctp_hdr->source); 1839 1840 /* Populate the association from the cookie. */ 1841 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie)); 1842 1843 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie, 1844 GFP_ATOMIC) < 0) { 1845 *error = -SCTP_IERROR_NOMEM; 1846 goto fail; 1847 } 1848 1849 /* Also, add the destination address. */ 1850 if (list_empty(&retval->base.bind_addr.address_list)) { 1851 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest, 1852 sizeof(chunk->dest), SCTP_ADDR_SRC, 1853 GFP_ATOMIC); 1854 } 1855 1856 retval->next_tsn = retval->c.initial_tsn; 1857 retval->ctsn_ack_point = retval->next_tsn - 1; 1858 retval->addip_serial = retval->c.initial_tsn; 1859 retval->adv_peer_ack_point = retval->ctsn_ack_point; 1860 retval->peer.prsctp_capable = retval->c.prsctp_capable; 1861 retval->peer.adaptation_ind = retval->c.adaptation_ind; 1862 1863 /* The INIT stuff will be done by the side effects. */ 1864 return retval; 1865 1866 fail: 1867 if (retval) 1868 sctp_association_free(retval); 1869 1870 return NULL; 1871 1872 malformed: 1873 /* Yikes! The packet is either corrupt or deliberately 1874 * malformed. 1875 */ 1876 *error = -SCTP_IERROR_MALFORMED; 1877 goto fail; 1878 } 1879 1880 /******************************************************************** 1881 * 3rd Level Abstractions 1882 ********************************************************************/ 1883 1884 struct __sctp_missing { 1885 __be32 num_missing; 1886 __be16 type; 1887 } __packed; 1888 1889 /* 1890 * Report a missing mandatory parameter. 1891 */ 1892 static int sctp_process_missing_param(const struct sctp_association *asoc, 1893 sctp_param_t paramtype, 1894 struct sctp_chunk *chunk, 1895 struct sctp_chunk **errp) 1896 { 1897 struct __sctp_missing report; 1898 __u16 len; 1899 1900 len = WORD_ROUND(sizeof(report)); 1901 1902 /* Make an ERROR chunk, preparing enough room for 1903 * returning multiple unknown parameters. 1904 */ 1905 if (!*errp) 1906 *errp = sctp_make_op_error_space(asoc, chunk, len); 1907 1908 if (*errp) { 1909 report.num_missing = htonl(1); 1910 report.type = paramtype; 1911 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM, 1912 sizeof(report)); 1913 sctp_addto_chunk(*errp, sizeof(report), &report); 1914 } 1915 1916 /* Stop processing this chunk. */ 1917 return 0; 1918 } 1919 1920 /* Report an Invalid Mandatory Parameter. */ 1921 static int sctp_process_inv_mandatory(const struct sctp_association *asoc, 1922 struct sctp_chunk *chunk, 1923 struct sctp_chunk **errp) 1924 { 1925 /* Invalid Mandatory Parameter Error has no payload. */ 1926 1927 if (!*errp) 1928 *errp = sctp_make_op_error_space(asoc, chunk, 0); 1929 1930 if (*errp) 1931 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0); 1932 1933 /* Stop processing this chunk. */ 1934 return 0; 1935 } 1936 1937 static int sctp_process_inv_paramlength(const struct sctp_association *asoc, 1938 struct sctp_paramhdr *param, 1939 const struct sctp_chunk *chunk, 1940 struct sctp_chunk **errp) 1941 { 1942 /* This is a fatal error. Any accumulated non-fatal errors are 1943 * not reported. 1944 */ 1945 if (*errp) 1946 sctp_chunk_free(*errp); 1947 1948 /* Create an error chunk and fill it in with our payload. */ 1949 *errp = sctp_make_violation_paramlen(asoc, chunk, param); 1950 1951 return 0; 1952 } 1953 1954 1955 /* Do not attempt to handle the HOST_NAME parm. However, do 1956 * send back an indicator to the peer. 1957 */ 1958 static int sctp_process_hn_param(const struct sctp_association *asoc, 1959 union sctp_params param, 1960 struct sctp_chunk *chunk, 1961 struct sctp_chunk **errp) 1962 { 1963 __u16 len = ntohs(param.p->length); 1964 1965 /* Processing of the HOST_NAME parameter will generate an 1966 * ABORT. If we've accumulated any non-fatal errors, they 1967 * would be unrecognized parameters and we should not include 1968 * them in the ABORT. 1969 */ 1970 if (*errp) 1971 sctp_chunk_free(*errp); 1972 1973 *errp = sctp_make_op_error_space(asoc, chunk, len); 1974 1975 if (*errp) { 1976 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len); 1977 sctp_addto_chunk(*errp, len, param.v); 1978 } 1979 1980 /* Stop processing this chunk. */ 1981 return 0; 1982 } 1983 1984 static int sctp_verify_ext_param(struct net *net, union sctp_params param) 1985 { 1986 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 1987 int have_auth = 0; 1988 int have_asconf = 0; 1989 int i; 1990 1991 for (i = 0; i < num_ext; i++) { 1992 switch (param.ext->chunks[i]) { 1993 case SCTP_CID_AUTH: 1994 have_auth = 1; 1995 break; 1996 case SCTP_CID_ASCONF: 1997 case SCTP_CID_ASCONF_ACK: 1998 have_asconf = 1; 1999 break; 2000 } 2001 } 2002 2003 /* ADD-IP Security: The draft requires us to ABORT or ignore the 2004 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this 2005 * only if ADD-IP is turned on and we are not backward-compatible 2006 * mode. 2007 */ 2008 if (net->sctp.addip_noauth) 2009 return 1; 2010 2011 if (net->sctp.addip_enable && !have_auth && have_asconf) 2012 return 0; 2013 2014 return 1; 2015 } 2016 2017 static void sctp_process_ext_param(struct sctp_association *asoc, 2018 union sctp_params param) 2019 { 2020 struct net *net = sock_net(asoc->base.sk); 2021 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2022 int i; 2023 2024 for (i = 0; i < num_ext; i++) { 2025 switch (param.ext->chunks[i]) { 2026 case SCTP_CID_FWD_TSN: 2027 if (net->sctp.prsctp_enable && !asoc->peer.prsctp_capable) 2028 asoc->peer.prsctp_capable = 1; 2029 break; 2030 case SCTP_CID_AUTH: 2031 /* if the peer reports AUTH, assume that he 2032 * supports AUTH. 2033 */ 2034 if (asoc->ep->auth_enable) 2035 asoc->peer.auth_capable = 1; 2036 break; 2037 case SCTP_CID_ASCONF: 2038 case SCTP_CID_ASCONF_ACK: 2039 if (net->sctp.addip_enable) 2040 asoc->peer.asconf_capable = 1; 2041 break; 2042 default: 2043 break; 2044 } 2045 } 2046 } 2047 2048 /* RFC 3.2.1 & the Implementers Guide 2.2. 2049 * 2050 * The Parameter Types are encoded such that the 2051 * highest-order two bits specify the action that must be 2052 * taken if the processing endpoint does not recognize the 2053 * Parameter Type. 2054 * 2055 * 00 - Stop processing this parameter; do not process any further 2056 * parameters within this chunk 2057 * 2058 * 01 - Stop processing this parameter, do not process any further 2059 * parameters within this chunk, and report the unrecognized 2060 * parameter in an 'Unrecognized Parameter' ERROR chunk. 2061 * 2062 * 10 - Skip this parameter and continue processing. 2063 * 2064 * 11 - Skip this parameter and continue processing but 2065 * report the unrecognized parameter in an 2066 * 'Unrecognized Parameter' ERROR chunk. 2067 * 2068 * Return value: 2069 * SCTP_IERROR_NO_ERROR - continue with the chunk 2070 * SCTP_IERROR_ERROR - stop and report an error. 2071 * SCTP_IERROR_NOMEME - out of memory. 2072 */ 2073 static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc, 2074 union sctp_params param, 2075 struct sctp_chunk *chunk, 2076 struct sctp_chunk **errp) 2077 { 2078 int retval = SCTP_IERROR_NO_ERROR; 2079 2080 switch (param.p->type & SCTP_PARAM_ACTION_MASK) { 2081 case SCTP_PARAM_ACTION_DISCARD: 2082 retval = SCTP_IERROR_ERROR; 2083 break; 2084 case SCTP_PARAM_ACTION_SKIP: 2085 break; 2086 case SCTP_PARAM_ACTION_DISCARD_ERR: 2087 retval = SCTP_IERROR_ERROR; 2088 /* Fall through */ 2089 case SCTP_PARAM_ACTION_SKIP_ERR: 2090 /* Make an ERROR chunk, preparing enough room for 2091 * returning multiple unknown parameters. 2092 */ 2093 if (NULL == *errp) 2094 *errp = sctp_make_op_error_fixed(asoc, chunk); 2095 2096 if (*errp) { 2097 if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM, 2098 WORD_ROUND(ntohs(param.p->length)))) 2099 sctp_addto_chunk_fixed(*errp, 2100 WORD_ROUND(ntohs(param.p->length)), 2101 param.v); 2102 } else { 2103 /* If there is no memory for generating the ERROR 2104 * report as specified, an ABORT will be triggered 2105 * to the peer and the association won't be 2106 * established. 2107 */ 2108 retval = SCTP_IERROR_NOMEM; 2109 } 2110 break; 2111 default: 2112 break; 2113 } 2114 2115 return retval; 2116 } 2117 2118 /* Verify variable length parameters 2119 * Return values: 2120 * SCTP_IERROR_ABORT - trigger an ABORT 2121 * SCTP_IERROR_NOMEM - out of memory (abort) 2122 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR 2123 * SCTP_IERROR_NO_ERROR - continue with the chunk 2124 */ 2125 static sctp_ierror_t sctp_verify_param(struct net *net, 2126 const struct sctp_endpoint *ep, 2127 const struct sctp_association *asoc, 2128 union sctp_params param, 2129 sctp_cid_t cid, 2130 struct sctp_chunk *chunk, 2131 struct sctp_chunk **err_chunk) 2132 { 2133 struct sctp_hmac_algo_param *hmacs; 2134 int retval = SCTP_IERROR_NO_ERROR; 2135 __u16 n_elt, id = 0; 2136 int i; 2137 2138 /* FIXME - This routine is not looking at each parameter per the 2139 * chunk type, i.e., unrecognized parameters should be further 2140 * identified based on the chunk id. 2141 */ 2142 2143 switch (param.p->type) { 2144 case SCTP_PARAM_IPV4_ADDRESS: 2145 case SCTP_PARAM_IPV6_ADDRESS: 2146 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2147 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2148 case SCTP_PARAM_STATE_COOKIE: 2149 case SCTP_PARAM_HEARTBEAT_INFO: 2150 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2151 case SCTP_PARAM_ECN_CAPABLE: 2152 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2153 break; 2154 2155 case SCTP_PARAM_SUPPORTED_EXT: 2156 if (!sctp_verify_ext_param(net, param)) 2157 return SCTP_IERROR_ABORT; 2158 break; 2159 2160 case SCTP_PARAM_SET_PRIMARY: 2161 if (net->sctp.addip_enable) 2162 break; 2163 goto fallthrough; 2164 2165 case SCTP_PARAM_HOST_NAME_ADDRESS: 2166 /* Tell the peer, we won't support this param. */ 2167 sctp_process_hn_param(asoc, param, chunk, err_chunk); 2168 retval = SCTP_IERROR_ABORT; 2169 break; 2170 2171 case SCTP_PARAM_FWD_TSN_SUPPORT: 2172 if (net->sctp.prsctp_enable) 2173 break; 2174 goto fallthrough; 2175 2176 case SCTP_PARAM_RANDOM: 2177 if (!ep->auth_enable) 2178 goto fallthrough; 2179 2180 /* SCTP-AUTH: Secion 6.1 2181 * If the random number is not 32 byte long the association 2182 * MUST be aborted. The ABORT chunk SHOULD contain the error 2183 * cause 'Protocol Violation'. 2184 */ 2185 if (SCTP_AUTH_RANDOM_LENGTH != 2186 ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) { 2187 sctp_process_inv_paramlength(asoc, param.p, 2188 chunk, err_chunk); 2189 retval = SCTP_IERROR_ABORT; 2190 } 2191 break; 2192 2193 case SCTP_PARAM_CHUNKS: 2194 if (!ep->auth_enable) 2195 goto fallthrough; 2196 2197 /* SCTP-AUTH: Section 3.2 2198 * The CHUNKS parameter MUST be included once in the INIT or 2199 * INIT-ACK chunk if the sender wants to receive authenticated 2200 * chunks. Its maximum length is 260 bytes. 2201 */ 2202 if (260 < ntohs(param.p->length)) { 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_HMAC_ALGO: 2210 if (!ep->auth_enable) 2211 goto fallthrough; 2212 2213 hmacs = (struct sctp_hmac_algo_param *)param.p; 2214 n_elt = (ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) >> 1; 2215 2216 /* SCTP-AUTH: Section 6.1 2217 * The HMAC algorithm based on SHA-1 MUST be supported and 2218 * included in the HMAC-ALGO parameter. 2219 */ 2220 for (i = 0; i < n_elt; i++) { 2221 id = ntohs(hmacs->hmac_ids[i]); 2222 2223 if (id == SCTP_AUTH_HMAC_ID_SHA1) 2224 break; 2225 } 2226 2227 if (id != SCTP_AUTH_HMAC_ID_SHA1) { 2228 sctp_process_inv_paramlength(asoc, param.p, chunk, 2229 err_chunk); 2230 retval = SCTP_IERROR_ABORT; 2231 } 2232 break; 2233 fallthrough: 2234 default: 2235 pr_debug("%s: unrecognized param:%d for chunk:%d\n", 2236 __func__, ntohs(param.p->type), cid); 2237 2238 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk); 2239 break; 2240 } 2241 return retval; 2242 } 2243 2244 /* Verify the INIT packet before we process it. */ 2245 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, 2246 const struct sctp_association *asoc, sctp_cid_t cid, 2247 sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk, 2248 struct sctp_chunk **errp) 2249 { 2250 union sctp_params param; 2251 bool has_cookie = false; 2252 int result; 2253 2254 /* Check for missing mandatory parameters. Note: Initial TSN is 2255 * also mandatory, but is not checked here since the valid range 2256 * is 0..2**32-1. RFC4960, section 3.3.3. 2257 */ 2258 if (peer_init->init_hdr.num_outbound_streams == 0 || 2259 peer_init->init_hdr.num_inbound_streams == 0 || 2260 peer_init->init_hdr.init_tag == 0 || 2261 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW) 2262 return sctp_process_inv_mandatory(asoc, chunk, errp); 2263 2264 sctp_walk_params(param, peer_init, init_hdr.params) { 2265 if (param.p->type == SCTP_PARAM_STATE_COOKIE) 2266 has_cookie = true; 2267 } 2268 2269 /* There is a possibility that a parameter length was bad and 2270 * in that case we would have stoped walking the parameters. 2271 * The current param.p would point at the bad one. 2272 * Current consensus on the mailing list is to generate a PROTOCOL 2273 * VIOLATION error. We build the ERROR chunk here and let the normal 2274 * error handling code build and send the packet. 2275 */ 2276 if (param.v != (void *)chunk->chunk_end) 2277 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp); 2278 2279 /* The only missing mandatory param possible today is 2280 * the state cookie for an INIT-ACK chunk. 2281 */ 2282 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) 2283 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE, 2284 chunk, errp); 2285 2286 /* Verify all the variable length parameters */ 2287 sctp_walk_params(param, peer_init, init_hdr.params) { 2288 result = sctp_verify_param(net, ep, asoc, param, cid, 2289 chunk, errp); 2290 switch (result) { 2291 case SCTP_IERROR_ABORT: 2292 case SCTP_IERROR_NOMEM: 2293 return 0; 2294 case SCTP_IERROR_ERROR: 2295 return 1; 2296 case SCTP_IERROR_NO_ERROR: 2297 default: 2298 break; 2299 } 2300 2301 } /* for (loop through all parameters) */ 2302 2303 return 1; 2304 } 2305 2306 /* Unpack the parameters in an INIT packet into an association. 2307 * Returns 0 on failure, else success. 2308 * FIXME: This is an association method. 2309 */ 2310 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, 2311 const union sctp_addr *peer_addr, 2312 sctp_init_chunk_t *peer_init, gfp_t gfp) 2313 { 2314 struct net *net = sock_net(asoc->base.sk); 2315 union sctp_params param; 2316 struct sctp_transport *transport; 2317 struct list_head *pos, *temp; 2318 struct sctp_af *af; 2319 union sctp_addr addr; 2320 char *cookie; 2321 int src_match = 0; 2322 2323 /* We must include the address that the INIT packet came from. 2324 * This is the only address that matters for an INIT packet. 2325 * When processing a COOKIE ECHO, we retrieve the from address 2326 * of the INIT from the cookie. 2327 */ 2328 2329 /* This implementation defaults to making the first transport 2330 * added as the primary transport. The source address seems to 2331 * be a a better choice than any of the embedded addresses. 2332 */ 2333 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE)) 2334 goto nomem; 2335 2336 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr)) 2337 src_match = 1; 2338 2339 /* Process the initialization parameters. */ 2340 sctp_walk_params(param, peer_init, init_hdr.params) { 2341 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 2342 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) { 2343 af = sctp_get_af_specific(param_type2af(param.p->type)); 2344 af->from_addr_param(&addr, param.addr, 2345 chunk->sctp_hdr->source, 0); 2346 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr)) 2347 src_match = 1; 2348 } 2349 2350 if (!sctp_process_param(asoc, param, peer_addr, gfp)) 2351 goto clean_up; 2352 } 2353 2354 /* source address of chunk may not match any valid address */ 2355 if (!src_match) 2356 goto clean_up; 2357 2358 /* AUTH: After processing the parameters, make sure that we 2359 * have all the required info to potentially do authentications. 2360 */ 2361 if (asoc->peer.auth_capable && (!asoc->peer.peer_random || 2362 !asoc->peer.peer_hmacs)) 2363 asoc->peer.auth_capable = 0; 2364 2365 /* In a non-backward compatible mode, if the peer claims 2366 * support for ADD-IP but not AUTH, the ADD-IP spec states 2367 * that we MUST ABORT the association. Section 6. The section 2368 * also give us an option to silently ignore the packet, which 2369 * is what we'll do here. 2370 */ 2371 if (!net->sctp.addip_noauth && 2372 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) { 2373 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP | 2374 SCTP_PARAM_DEL_IP | 2375 SCTP_PARAM_SET_PRIMARY); 2376 asoc->peer.asconf_capable = 0; 2377 goto clean_up; 2378 } 2379 2380 /* Walk list of transports, removing transports in the UNKNOWN state. */ 2381 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2382 transport = list_entry(pos, struct sctp_transport, transports); 2383 if (transport->state == SCTP_UNKNOWN) { 2384 sctp_assoc_rm_peer(asoc, transport); 2385 } 2386 } 2387 2388 /* The fixed INIT headers are always in network byte 2389 * order. 2390 */ 2391 asoc->peer.i.init_tag = 2392 ntohl(peer_init->init_hdr.init_tag); 2393 asoc->peer.i.a_rwnd = 2394 ntohl(peer_init->init_hdr.a_rwnd); 2395 asoc->peer.i.num_outbound_streams = 2396 ntohs(peer_init->init_hdr.num_outbound_streams); 2397 asoc->peer.i.num_inbound_streams = 2398 ntohs(peer_init->init_hdr.num_inbound_streams); 2399 asoc->peer.i.initial_tsn = 2400 ntohl(peer_init->init_hdr.initial_tsn); 2401 2402 /* Apply the upper bounds for output streams based on peer's 2403 * number of inbound streams. 2404 */ 2405 if (asoc->c.sinit_num_ostreams > 2406 ntohs(peer_init->init_hdr.num_inbound_streams)) { 2407 asoc->c.sinit_num_ostreams = 2408 ntohs(peer_init->init_hdr.num_inbound_streams); 2409 } 2410 2411 if (asoc->c.sinit_max_instreams > 2412 ntohs(peer_init->init_hdr.num_outbound_streams)) { 2413 asoc->c.sinit_max_instreams = 2414 ntohs(peer_init->init_hdr.num_outbound_streams); 2415 } 2416 2417 /* Copy Initiation tag from INIT to VT_peer in cookie. */ 2418 asoc->c.peer_vtag = asoc->peer.i.init_tag; 2419 2420 /* Peer Rwnd : Current calculated value of the peer's rwnd. */ 2421 asoc->peer.rwnd = asoc->peer.i.a_rwnd; 2422 2423 /* Copy cookie in case we need to resend COOKIE-ECHO. */ 2424 cookie = asoc->peer.cookie; 2425 if (cookie) { 2426 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp); 2427 if (!asoc->peer.cookie) 2428 goto clean_up; 2429 } 2430 2431 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily 2432 * high (for example, implementations MAY use the size of the receiver 2433 * advertised window). 2434 */ 2435 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 2436 transports) { 2437 transport->ssthresh = asoc->peer.i.a_rwnd; 2438 } 2439 2440 /* Set up the TSN tracking pieces. */ 2441 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL, 2442 asoc->peer.i.initial_tsn, gfp)) 2443 goto clean_up; 2444 2445 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number 2446 * 2447 * The stream sequence number in all the streams shall start 2448 * from 0 when the association is established. Also, when the 2449 * stream sequence number reaches the value 65535 the next 2450 * stream sequence number shall be set to 0. 2451 */ 2452 2453 /* Allocate storage for the negotiated streams if it is not a temporary 2454 * association. 2455 */ 2456 if (!asoc->temp) { 2457 int error; 2458 2459 asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams, 2460 asoc->c.sinit_num_ostreams, gfp); 2461 if (!asoc->ssnmap) 2462 goto clean_up; 2463 2464 error = sctp_assoc_set_id(asoc, gfp); 2465 if (error) 2466 goto clean_up; 2467 } 2468 2469 /* ADDIP Section 4.1 ASCONF Chunk Procedures 2470 * 2471 * When an endpoint has an ASCONF signaled change to be sent to the 2472 * remote endpoint it should do the following: 2473 * ... 2474 * A2) A serial number should be assigned to the Chunk. The serial 2475 * number should be a monotonically increasing number. All serial 2476 * numbers are defined to be initialized at the start of the 2477 * association to the same value as the Initial TSN. 2478 */ 2479 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1; 2480 return 1; 2481 2482 clean_up: 2483 /* Release the transport structures. */ 2484 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 2485 transport = list_entry(pos, struct sctp_transport, transports); 2486 if (transport->state != SCTP_ACTIVE) 2487 sctp_assoc_rm_peer(asoc, transport); 2488 } 2489 2490 nomem: 2491 return 0; 2492 } 2493 2494 2495 /* Update asoc with the option described in param. 2496 * 2497 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT 2498 * 2499 * asoc is the association to update. 2500 * param is the variable length parameter to use for update. 2501 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO. 2502 * If the current packet is an INIT we want to minimize the amount of 2503 * work we do. In particular, we should not build transport 2504 * structures for the addresses. 2505 */ 2506 static int sctp_process_param(struct sctp_association *asoc, 2507 union sctp_params param, 2508 const union sctp_addr *peer_addr, 2509 gfp_t gfp) 2510 { 2511 struct net *net = sock_net(asoc->base.sk); 2512 union sctp_addr addr; 2513 int i; 2514 __u16 sat; 2515 int retval = 1; 2516 sctp_scope_t scope; 2517 u32 stale; 2518 struct sctp_af *af; 2519 union sctp_addr_param *addr_param; 2520 struct sctp_transport *t; 2521 struct sctp_endpoint *ep = asoc->ep; 2522 2523 /* We maintain all INIT parameters in network byte order all the 2524 * time. This allows us to not worry about whether the parameters 2525 * came from a fresh INIT, and INIT ACK, or were stored in a cookie. 2526 */ 2527 switch (param.p->type) { 2528 case SCTP_PARAM_IPV6_ADDRESS: 2529 if (PF_INET6 != asoc->base.sk->sk_family) 2530 break; 2531 goto do_addr_param; 2532 2533 case SCTP_PARAM_IPV4_ADDRESS: 2534 /* v4 addresses are not allowed on v6-only socket */ 2535 if (ipv6_only_sock(asoc->base.sk)) 2536 break; 2537 do_addr_param: 2538 af = sctp_get_af_specific(param_type2af(param.p->type)); 2539 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0); 2540 scope = sctp_scope(peer_addr); 2541 if (sctp_in_scope(net, &addr, scope)) 2542 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED)) 2543 return 0; 2544 break; 2545 2546 case SCTP_PARAM_COOKIE_PRESERVATIVE: 2547 if (!net->sctp.cookie_preserve_enable) 2548 break; 2549 2550 stale = ntohl(param.life->lifespan_increment); 2551 2552 /* Suggested Cookie Life span increment's unit is msec, 2553 * (1/1000sec). 2554 */ 2555 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale); 2556 break; 2557 2558 case SCTP_PARAM_HOST_NAME_ADDRESS: 2559 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__); 2560 break; 2561 2562 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES: 2563 /* Turn off the default values first so we'll know which 2564 * ones are really set by the peer. 2565 */ 2566 asoc->peer.ipv4_address = 0; 2567 asoc->peer.ipv6_address = 0; 2568 2569 /* Assume that peer supports the address family 2570 * by which it sends a packet. 2571 */ 2572 if (peer_addr->sa.sa_family == AF_INET6) 2573 asoc->peer.ipv6_address = 1; 2574 else if (peer_addr->sa.sa_family == AF_INET) 2575 asoc->peer.ipv4_address = 1; 2576 2577 /* Cycle through address types; avoid divide by 0. */ 2578 sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2579 if (sat) 2580 sat /= sizeof(__u16); 2581 2582 for (i = 0; i < sat; ++i) { 2583 switch (param.sat->types[i]) { 2584 case SCTP_PARAM_IPV4_ADDRESS: 2585 asoc->peer.ipv4_address = 1; 2586 break; 2587 2588 case SCTP_PARAM_IPV6_ADDRESS: 2589 if (PF_INET6 == asoc->base.sk->sk_family) 2590 asoc->peer.ipv6_address = 1; 2591 break; 2592 2593 case SCTP_PARAM_HOST_NAME_ADDRESS: 2594 asoc->peer.hostname_address = 1; 2595 break; 2596 2597 default: /* Just ignore anything else. */ 2598 break; 2599 } 2600 } 2601 break; 2602 2603 case SCTP_PARAM_STATE_COOKIE: 2604 asoc->peer.cookie_len = 2605 ntohs(param.p->length) - sizeof(sctp_paramhdr_t); 2606 asoc->peer.cookie = param.cookie->body; 2607 break; 2608 2609 case SCTP_PARAM_HEARTBEAT_INFO: 2610 /* Would be odd to receive, but it causes no problems. */ 2611 break; 2612 2613 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS: 2614 /* Rejected during verify stage. */ 2615 break; 2616 2617 case SCTP_PARAM_ECN_CAPABLE: 2618 asoc->peer.ecn_capable = 1; 2619 break; 2620 2621 case SCTP_PARAM_ADAPTATION_LAYER_IND: 2622 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind); 2623 break; 2624 2625 case SCTP_PARAM_SET_PRIMARY: 2626 if (!net->sctp.addip_enable) 2627 goto fall_through; 2628 2629 addr_param = param.v + sizeof(sctp_addip_param_t); 2630 2631 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 2632 if (af == NULL) 2633 break; 2634 2635 af->from_addr_param(&addr, addr_param, 2636 htons(asoc->peer.port), 0); 2637 2638 /* if the address is invalid, we can't process it. 2639 * XXX: see spec for what to do. 2640 */ 2641 if (!af->addr_valid(&addr, NULL, NULL)) 2642 break; 2643 2644 t = sctp_assoc_lookup_paddr(asoc, &addr); 2645 if (!t) 2646 break; 2647 2648 sctp_assoc_set_primary(asoc, t); 2649 break; 2650 2651 case SCTP_PARAM_SUPPORTED_EXT: 2652 sctp_process_ext_param(asoc, param); 2653 break; 2654 2655 case SCTP_PARAM_FWD_TSN_SUPPORT: 2656 if (net->sctp.prsctp_enable) { 2657 asoc->peer.prsctp_capable = 1; 2658 break; 2659 } 2660 /* Fall Through */ 2661 goto fall_through; 2662 2663 case SCTP_PARAM_RANDOM: 2664 if (!ep->auth_enable) 2665 goto fall_through; 2666 2667 /* Save peer's random parameter */ 2668 asoc->peer.peer_random = kmemdup(param.p, 2669 ntohs(param.p->length), gfp); 2670 if (!asoc->peer.peer_random) { 2671 retval = 0; 2672 break; 2673 } 2674 break; 2675 2676 case SCTP_PARAM_HMAC_ALGO: 2677 if (!ep->auth_enable) 2678 goto fall_through; 2679 2680 /* Save peer's HMAC list */ 2681 asoc->peer.peer_hmacs = kmemdup(param.p, 2682 ntohs(param.p->length), gfp); 2683 if (!asoc->peer.peer_hmacs) { 2684 retval = 0; 2685 break; 2686 } 2687 2688 /* Set the default HMAC the peer requested*/ 2689 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo); 2690 break; 2691 2692 case SCTP_PARAM_CHUNKS: 2693 if (!ep->auth_enable) 2694 goto fall_through; 2695 2696 asoc->peer.peer_chunks = kmemdup(param.p, 2697 ntohs(param.p->length), gfp); 2698 if (!asoc->peer.peer_chunks) 2699 retval = 0; 2700 break; 2701 fall_through: 2702 default: 2703 /* Any unrecognized parameters should have been caught 2704 * and handled by sctp_verify_param() which should be 2705 * called prior to this routine. Simply log the error 2706 * here. 2707 */ 2708 pr_debug("%s: ignoring param:%d for association:%p.\n", 2709 __func__, ntohs(param.p->type), asoc); 2710 break; 2711 } 2712 2713 return retval; 2714 } 2715 2716 /* Select a new verification tag. */ 2717 __u32 sctp_generate_tag(const struct sctp_endpoint *ep) 2718 { 2719 /* I believe that this random number generator complies with RFC1750. 2720 * A tag of 0 is reserved for special cases (e.g. INIT). 2721 */ 2722 __u32 x; 2723 2724 do { 2725 get_random_bytes(&x, sizeof(__u32)); 2726 } while (x == 0); 2727 2728 return x; 2729 } 2730 2731 /* Select an initial TSN to send during startup. */ 2732 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep) 2733 { 2734 __u32 retval; 2735 2736 get_random_bytes(&retval, sizeof(__u32)); 2737 return retval; 2738 } 2739 2740 /* 2741 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF) 2742 * 0 1 2 3 2743 * 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 2744 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2745 * | Type = 0xC1 | Chunk Flags | Chunk Length | 2746 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2747 * | Serial Number | 2748 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2749 * | Address Parameter | 2750 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2751 * | ASCONF Parameter #1 | 2752 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2753 * \ \ 2754 * / .... / 2755 * \ \ 2756 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2757 * | ASCONF Parameter #N | 2758 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2759 * 2760 * Address Parameter and other parameter will not be wrapped in this function 2761 */ 2762 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc, 2763 union sctp_addr *addr, 2764 int vparam_len) 2765 { 2766 sctp_addiphdr_t asconf; 2767 struct sctp_chunk *retval; 2768 int length = sizeof(asconf) + vparam_len; 2769 union sctp_addr_param addrparam; 2770 int addrlen; 2771 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2772 2773 addrlen = af->to_addr_param(addr, &addrparam); 2774 if (!addrlen) 2775 return NULL; 2776 length += addrlen; 2777 2778 /* Create the chunk. */ 2779 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length, 2780 GFP_ATOMIC); 2781 if (!retval) 2782 return NULL; 2783 2784 asconf.serial = htonl(asoc->addip_serial++); 2785 2786 retval->subh.addip_hdr = 2787 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2788 retval->param_hdr.v = 2789 sctp_addto_chunk(retval, addrlen, &addrparam); 2790 2791 return retval; 2792 } 2793 2794 /* ADDIP 2795 * 3.2.1 Add IP Address 2796 * 0 1 2 3 2797 * 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 2798 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2799 * | Type = 0xC001 | Length = Variable | 2800 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2801 * | ASCONF-Request Correlation ID | 2802 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2803 * | Address Parameter | 2804 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2805 * 2806 * 3.2.2 Delete IP Address 2807 * 0 1 2 3 2808 * 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 2809 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2810 * | Type = 0xC002 | Length = Variable | 2811 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2812 * | ASCONF-Request Correlation ID | 2813 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2814 * | Address Parameter | 2815 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2816 * 2817 */ 2818 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc, 2819 union sctp_addr *laddr, 2820 struct sockaddr *addrs, 2821 int addrcnt, 2822 __be16 flags) 2823 { 2824 sctp_addip_param_t param; 2825 struct sctp_chunk *retval; 2826 union sctp_addr_param addr_param; 2827 union sctp_addr *addr; 2828 void *addr_buf; 2829 struct sctp_af *af; 2830 int paramlen = sizeof(param); 2831 int addr_param_len = 0; 2832 int totallen = 0; 2833 int i; 2834 int del_pickup = 0; 2835 2836 /* Get total length of all the address parameters. */ 2837 addr_buf = addrs; 2838 for (i = 0; i < addrcnt; i++) { 2839 addr = addr_buf; 2840 af = sctp_get_af_specific(addr->v4.sin_family); 2841 addr_param_len = af->to_addr_param(addr, &addr_param); 2842 2843 totallen += paramlen; 2844 totallen += addr_param_len; 2845 2846 addr_buf += af->sockaddr_len; 2847 if (asoc->asconf_addr_del_pending && !del_pickup) { 2848 /* reuse the parameter length from the same scope one */ 2849 totallen += paramlen; 2850 totallen += addr_param_len; 2851 del_pickup = 1; 2852 2853 pr_debug("%s: picked same-scope del_pending addr, " 2854 "totallen for all addresses is %d\n", 2855 __func__, totallen); 2856 } 2857 } 2858 2859 /* Create an asconf chunk with the required length. */ 2860 retval = sctp_make_asconf(asoc, laddr, totallen); 2861 if (!retval) 2862 return NULL; 2863 2864 /* Add the address parameters to the asconf chunk. */ 2865 addr_buf = addrs; 2866 for (i = 0; i < addrcnt; i++) { 2867 addr = addr_buf; 2868 af = sctp_get_af_specific(addr->v4.sin_family); 2869 addr_param_len = af->to_addr_param(addr, &addr_param); 2870 param.param_hdr.type = flags; 2871 param.param_hdr.length = htons(paramlen + addr_param_len); 2872 param.crr_id = i; 2873 2874 sctp_addto_chunk(retval, paramlen, ¶m); 2875 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2876 2877 addr_buf += af->sockaddr_len; 2878 } 2879 if (flags == SCTP_PARAM_ADD_IP && del_pickup) { 2880 addr = asoc->asconf_addr_del_pending; 2881 af = sctp_get_af_specific(addr->v4.sin_family); 2882 addr_param_len = af->to_addr_param(addr, &addr_param); 2883 param.param_hdr.type = SCTP_PARAM_DEL_IP; 2884 param.param_hdr.length = htons(paramlen + addr_param_len); 2885 param.crr_id = i; 2886 2887 sctp_addto_chunk(retval, paramlen, ¶m); 2888 sctp_addto_chunk(retval, addr_param_len, &addr_param); 2889 } 2890 return retval; 2891 } 2892 2893 /* ADDIP 2894 * 3.2.4 Set Primary IP Address 2895 * 0 1 2 3 2896 * 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 2897 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2898 * | Type =0xC004 | Length = Variable | 2899 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2900 * | ASCONF-Request Correlation ID | 2901 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2902 * | Address Parameter | 2903 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2904 * 2905 * Create an ASCONF chunk with Set Primary IP address parameter. 2906 */ 2907 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc, 2908 union sctp_addr *addr) 2909 { 2910 sctp_addip_param_t param; 2911 struct sctp_chunk *retval; 2912 int len = sizeof(param); 2913 union sctp_addr_param addrparam; 2914 int addrlen; 2915 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family); 2916 2917 addrlen = af->to_addr_param(addr, &addrparam); 2918 if (!addrlen) 2919 return NULL; 2920 len += addrlen; 2921 2922 /* Create the chunk and make asconf header. */ 2923 retval = sctp_make_asconf(asoc, addr, len); 2924 if (!retval) 2925 return NULL; 2926 2927 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY; 2928 param.param_hdr.length = htons(len); 2929 param.crr_id = 0; 2930 2931 sctp_addto_chunk(retval, sizeof(param), ¶m); 2932 sctp_addto_chunk(retval, addrlen, &addrparam); 2933 2934 return retval; 2935 } 2936 2937 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK) 2938 * 0 1 2 3 2939 * 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 2940 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2941 * | Type = 0x80 | Chunk Flags | Chunk Length | 2942 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2943 * | Serial Number | 2944 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2945 * | ASCONF Parameter Response#1 | 2946 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2947 * \ \ 2948 * / .... / 2949 * \ \ 2950 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2951 * | ASCONF Parameter Response#N | 2952 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2953 * 2954 * Create an ASCONF_ACK chunk with enough space for the parameter responses. 2955 */ 2956 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc, 2957 __u32 serial, int vparam_len) 2958 { 2959 sctp_addiphdr_t asconf; 2960 struct sctp_chunk *retval; 2961 int length = sizeof(asconf) + vparam_len; 2962 2963 /* Create the chunk. */ 2964 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length, 2965 GFP_ATOMIC); 2966 if (!retval) 2967 return NULL; 2968 2969 asconf.serial = htonl(serial); 2970 2971 retval->subh.addip_hdr = 2972 sctp_addto_chunk(retval, sizeof(asconf), &asconf); 2973 2974 return retval; 2975 } 2976 2977 /* Add response parameters to an ASCONF_ACK chunk. */ 2978 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id, 2979 __be16 err_code, sctp_addip_param_t *asconf_param) 2980 { 2981 sctp_addip_param_t ack_param; 2982 sctp_errhdr_t err_param; 2983 int asconf_param_len = 0; 2984 int err_param_len = 0; 2985 __be16 response_type; 2986 2987 if (SCTP_ERROR_NO_ERROR == err_code) { 2988 response_type = SCTP_PARAM_SUCCESS_REPORT; 2989 } else { 2990 response_type = SCTP_PARAM_ERR_CAUSE; 2991 err_param_len = sizeof(err_param); 2992 if (asconf_param) 2993 asconf_param_len = 2994 ntohs(asconf_param->param_hdr.length); 2995 } 2996 2997 /* Add Success Indication or Error Cause Indication parameter. */ 2998 ack_param.param_hdr.type = response_type; 2999 ack_param.param_hdr.length = htons(sizeof(ack_param) + 3000 err_param_len + 3001 asconf_param_len); 3002 ack_param.crr_id = crr_id; 3003 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param); 3004 3005 if (SCTP_ERROR_NO_ERROR == err_code) 3006 return; 3007 3008 /* Add Error Cause parameter. */ 3009 err_param.cause = err_code; 3010 err_param.length = htons(err_param_len + asconf_param_len); 3011 sctp_addto_chunk(chunk, err_param_len, &err_param); 3012 3013 /* Add the failed TLV copied from ASCONF chunk. */ 3014 if (asconf_param) 3015 sctp_addto_chunk(chunk, asconf_param_len, asconf_param); 3016 } 3017 3018 /* Process a asconf parameter. */ 3019 static __be16 sctp_process_asconf_param(struct sctp_association *asoc, 3020 struct sctp_chunk *asconf, 3021 sctp_addip_param_t *asconf_param) 3022 { 3023 struct sctp_transport *peer; 3024 struct sctp_af *af; 3025 union sctp_addr addr; 3026 union sctp_addr_param *addr_param; 3027 3028 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t); 3029 3030 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP && 3031 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP && 3032 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY) 3033 return SCTP_ERROR_UNKNOWN_PARAM; 3034 3035 switch (addr_param->p.type) { 3036 case SCTP_PARAM_IPV6_ADDRESS: 3037 if (!asoc->peer.ipv6_address) 3038 return SCTP_ERROR_DNS_FAILED; 3039 break; 3040 case SCTP_PARAM_IPV4_ADDRESS: 3041 if (!asoc->peer.ipv4_address) 3042 return SCTP_ERROR_DNS_FAILED; 3043 break; 3044 default: 3045 return SCTP_ERROR_DNS_FAILED; 3046 } 3047 3048 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3049 if (unlikely(!af)) 3050 return SCTP_ERROR_DNS_FAILED; 3051 3052 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0); 3053 3054 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast 3055 * or multicast address. 3056 * (note: wildcard is permitted and requires special handling so 3057 * make sure we check for that) 3058 */ 3059 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb)) 3060 return SCTP_ERROR_DNS_FAILED; 3061 3062 switch (asconf_param->param_hdr.type) { 3063 case SCTP_PARAM_ADD_IP: 3064 /* Section 4.2.1: 3065 * If the address 0.0.0.0 or ::0 is provided, the source 3066 * address of the packet MUST be added. 3067 */ 3068 if (af->is_any(&addr)) 3069 memcpy(&addr, &asconf->source, sizeof(addr)); 3070 3071 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address 3072 * request and does not have the local resources to add this 3073 * new address to the association, it MUST return an Error 3074 * Cause TLV set to the new error code 'Operation Refused 3075 * Due to Resource Shortage'. 3076 */ 3077 3078 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED); 3079 if (!peer) 3080 return SCTP_ERROR_RSRC_LOW; 3081 3082 /* Start the heartbeat timer. */ 3083 sctp_transport_reset_hb_timer(peer); 3084 asoc->new_transport = peer; 3085 break; 3086 case SCTP_PARAM_DEL_IP: 3087 /* ADDIP 4.3 D7) If a request is received to delete the 3088 * last remaining IP address of a peer endpoint, the receiver 3089 * MUST send an Error Cause TLV with the error cause set to the 3090 * new error code 'Request to Delete Last Remaining IP Address'. 3091 */ 3092 if (asoc->peer.transport_count == 1) 3093 return SCTP_ERROR_DEL_LAST_IP; 3094 3095 /* ADDIP 4.3 D8) If a request is received to delete an IP 3096 * address which is also the source address of the IP packet 3097 * which contained the ASCONF chunk, the receiver MUST reject 3098 * this request. To reject the request the receiver MUST send 3099 * an Error Cause TLV set to the new error code 'Request to 3100 * Delete Source IP Address' 3101 */ 3102 if (sctp_cmp_addr_exact(&asconf->source, &addr)) 3103 return SCTP_ERROR_DEL_SRC_IP; 3104 3105 /* Section 4.2.2 3106 * If the address 0.0.0.0 or ::0 is provided, all 3107 * addresses of the peer except the source address of the 3108 * packet MUST be deleted. 3109 */ 3110 if (af->is_any(&addr)) { 3111 sctp_assoc_set_primary(asoc, asconf->transport); 3112 sctp_assoc_del_nonprimary_peers(asoc, 3113 asconf->transport); 3114 return SCTP_ERROR_NO_ERROR; 3115 } 3116 3117 /* If the address is not part of the association, the 3118 * ASCONF-ACK with Error Cause Indication Parameter 3119 * which including cause of Unresolvable Address should 3120 * be sent. 3121 */ 3122 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3123 if (!peer) 3124 return SCTP_ERROR_DNS_FAILED; 3125 3126 sctp_assoc_rm_peer(asoc, peer); 3127 break; 3128 case SCTP_PARAM_SET_PRIMARY: 3129 /* ADDIP Section 4.2.4 3130 * If the address 0.0.0.0 or ::0 is provided, the receiver 3131 * MAY mark the source address of the packet as its 3132 * primary. 3133 */ 3134 if (af->is_any(&addr)) 3135 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr)); 3136 3137 peer = sctp_assoc_lookup_paddr(asoc, &addr); 3138 if (!peer) 3139 return SCTP_ERROR_DNS_FAILED; 3140 3141 sctp_assoc_set_primary(asoc, peer); 3142 break; 3143 } 3144 3145 return SCTP_ERROR_NO_ERROR; 3146 } 3147 3148 /* Verify the ASCONF packet before we process it. */ 3149 bool sctp_verify_asconf(const struct sctp_association *asoc, 3150 struct sctp_chunk *chunk, bool addr_param_needed, 3151 struct sctp_paramhdr **errp) 3152 { 3153 sctp_addip_chunk_t *addip = (sctp_addip_chunk_t *) chunk->chunk_hdr; 3154 union sctp_params param; 3155 bool addr_param_seen = false; 3156 3157 sctp_walk_params(param, addip, addip_hdr.params) { 3158 size_t length = ntohs(param.p->length); 3159 3160 *errp = param.p; 3161 switch (param.p->type) { 3162 case SCTP_PARAM_ERR_CAUSE: 3163 break; 3164 case SCTP_PARAM_IPV4_ADDRESS: 3165 if (length != sizeof(sctp_ipv4addr_param_t)) 3166 return false; 3167 /* ensure there is only one addr param and it's in the 3168 * beginning of addip_hdr params, or we reject it. 3169 */ 3170 if (param.v != addip->addip_hdr.params) 3171 return false; 3172 addr_param_seen = true; 3173 break; 3174 case SCTP_PARAM_IPV6_ADDRESS: 3175 if (length != sizeof(sctp_ipv6addr_param_t)) 3176 return false; 3177 if (param.v != addip->addip_hdr.params) 3178 return false; 3179 addr_param_seen = true; 3180 break; 3181 case SCTP_PARAM_ADD_IP: 3182 case SCTP_PARAM_DEL_IP: 3183 case SCTP_PARAM_SET_PRIMARY: 3184 /* In ASCONF chunks, these need to be first. */ 3185 if (addr_param_needed && !addr_param_seen) 3186 return false; 3187 length = ntohs(param.addip->param_hdr.length); 3188 if (length < sizeof(sctp_addip_param_t) + 3189 sizeof(sctp_paramhdr_t)) 3190 return false; 3191 break; 3192 case SCTP_PARAM_SUCCESS_REPORT: 3193 case SCTP_PARAM_ADAPTATION_LAYER_IND: 3194 if (length != sizeof(sctp_addip_param_t)) 3195 return false; 3196 break; 3197 default: 3198 /* This is unkown to us, reject! */ 3199 return false; 3200 } 3201 } 3202 3203 /* Remaining sanity checks. */ 3204 if (addr_param_needed && !addr_param_seen) 3205 return false; 3206 if (!addr_param_needed && addr_param_seen) 3207 return false; 3208 if (param.v != chunk->chunk_end) 3209 return false; 3210 3211 return true; 3212 } 3213 3214 /* Process an incoming ASCONF chunk with the next expected serial no. and 3215 * return an ASCONF_ACK chunk to be sent in response. 3216 */ 3217 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc, 3218 struct sctp_chunk *asconf) 3219 { 3220 sctp_addip_chunk_t *addip = (sctp_addip_chunk_t *) asconf->chunk_hdr; 3221 bool all_param_pass = true; 3222 union sctp_params param; 3223 sctp_addiphdr_t *hdr; 3224 union sctp_addr_param *addr_param; 3225 sctp_addip_param_t *asconf_param; 3226 struct sctp_chunk *asconf_ack; 3227 __be16 err_code; 3228 int length = 0; 3229 int chunk_len; 3230 __u32 serial; 3231 3232 chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t); 3233 hdr = (sctp_addiphdr_t *)asconf->skb->data; 3234 serial = ntohl(hdr->serial); 3235 3236 /* Skip the addiphdr and store a pointer to address parameter. */ 3237 length = sizeof(sctp_addiphdr_t); 3238 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3239 chunk_len -= length; 3240 3241 /* Skip the address parameter and store a pointer to the first 3242 * asconf parameter. 3243 */ 3244 length = ntohs(addr_param->p.length); 3245 asconf_param = (void *)addr_param + length; 3246 chunk_len -= length; 3247 3248 /* create an ASCONF_ACK chunk. 3249 * Based on the definitions of parameters, we know that the size of 3250 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF 3251 * parameters. 3252 */ 3253 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4); 3254 if (!asconf_ack) 3255 goto done; 3256 3257 /* Process the TLVs contained within the ASCONF chunk. */ 3258 sctp_walk_params(param, addip, addip_hdr.params) { 3259 /* Skip preceeding address parameters. */ 3260 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS || 3261 param.p->type == SCTP_PARAM_IPV6_ADDRESS) 3262 continue; 3263 3264 err_code = sctp_process_asconf_param(asoc, asconf, 3265 param.addip); 3266 /* ADDIP 4.1 A7) 3267 * If an error response is received for a TLV parameter, 3268 * all TLVs with no response before the failed TLV are 3269 * considered successful if not reported. All TLVs after 3270 * the failed response are considered unsuccessful unless 3271 * a specific success indication is present for the parameter. 3272 */ 3273 if (err_code != SCTP_ERROR_NO_ERROR) 3274 all_param_pass = false; 3275 if (!all_param_pass) 3276 sctp_add_asconf_response(asconf_ack, param.addip->crr_id, 3277 err_code, param.addip); 3278 3279 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add 3280 * an IP address sends an 'Out of Resource' in its response, it 3281 * MUST also fail any subsequent add or delete requests bundled 3282 * in the ASCONF. 3283 */ 3284 if (err_code == SCTP_ERROR_RSRC_LOW) 3285 goto done; 3286 } 3287 done: 3288 asoc->peer.addip_serial++; 3289 3290 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc 3291 * after freeing the reference to old asconf ack if any. 3292 */ 3293 if (asconf_ack) { 3294 sctp_chunk_hold(asconf_ack); 3295 list_add_tail(&asconf_ack->transmitted_list, 3296 &asoc->asconf_ack_list); 3297 } 3298 3299 return asconf_ack; 3300 } 3301 3302 /* Process a asconf parameter that is successfully acked. */ 3303 static void sctp_asconf_param_success(struct sctp_association *asoc, 3304 sctp_addip_param_t *asconf_param) 3305 { 3306 struct sctp_af *af; 3307 union sctp_addr addr; 3308 struct sctp_bind_addr *bp = &asoc->base.bind_addr; 3309 union sctp_addr_param *addr_param; 3310 struct sctp_transport *transport; 3311 struct sctp_sockaddr_entry *saddr; 3312 3313 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t); 3314 3315 /* We have checked the packet before, so we do not check again. */ 3316 af = sctp_get_af_specific(param_type2af(addr_param->p.type)); 3317 af->from_addr_param(&addr, addr_param, htons(bp->port), 0); 3318 3319 switch (asconf_param->param_hdr.type) { 3320 case SCTP_PARAM_ADD_IP: 3321 /* This is always done in BH context with a socket lock 3322 * held, so the list can not change. 3323 */ 3324 local_bh_disable(); 3325 list_for_each_entry(saddr, &bp->address_list, list) { 3326 if (sctp_cmp_addr_exact(&saddr->a, &addr)) 3327 saddr->state = SCTP_ADDR_SRC; 3328 } 3329 local_bh_enable(); 3330 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3331 transports) { 3332 dst_release(transport->dst); 3333 transport->dst = NULL; 3334 } 3335 break; 3336 case SCTP_PARAM_DEL_IP: 3337 local_bh_disable(); 3338 sctp_del_bind_addr(bp, &addr); 3339 if (asoc->asconf_addr_del_pending != NULL && 3340 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) { 3341 kfree(asoc->asconf_addr_del_pending); 3342 asoc->asconf_addr_del_pending = NULL; 3343 } 3344 local_bh_enable(); 3345 list_for_each_entry(transport, &asoc->peer.transport_addr_list, 3346 transports) { 3347 dst_release(transport->dst); 3348 transport->dst = NULL; 3349 } 3350 break; 3351 default: 3352 break; 3353 } 3354 } 3355 3356 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk 3357 * for the given asconf parameter. If there is no response for this parameter, 3358 * return the error code based on the third argument 'no_err'. 3359 * ADDIP 4.1 3360 * A7) If an error response is received for a TLV parameter, all TLVs with no 3361 * response before the failed TLV are considered successful if not reported. 3362 * All TLVs after the failed response are considered unsuccessful unless a 3363 * specific success indication is present for the parameter. 3364 */ 3365 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack, 3366 sctp_addip_param_t *asconf_param, 3367 int no_err) 3368 { 3369 sctp_addip_param_t *asconf_ack_param; 3370 sctp_errhdr_t *err_param; 3371 int length; 3372 int asconf_ack_len; 3373 __be16 err_code; 3374 3375 if (no_err) 3376 err_code = SCTP_ERROR_NO_ERROR; 3377 else 3378 err_code = SCTP_ERROR_REQ_REFUSED; 3379 3380 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) - 3381 sizeof(sctp_chunkhdr_t); 3382 3383 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to 3384 * the first asconf_ack parameter. 3385 */ 3386 length = sizeof(sctp_addiphdr_t); 3387 asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data + 3388 length); 3389 asconf_ack_len -= length; 3390 3391 while (asconf_ack_len > 0) { 3392 if (asconf_ack_param->crr_id == asconf_param->crr_id) { 3393 switch (asconf_ack_param->param_hdr.type) { 3394 case SCTP_PARAM_SUCCESS_REPORT: 3395 return SCTP_ERROR_NO_ERROR; 3396 case SCTP_PARAM_ERR_CAUSE: 3397 length = sizeof(sctp_addip_param_t); 3398 err_param = (void *)asconf_ack_param + length; 3399 asconf_ack_len -= length; 3400 if (asconf_ack_len > 0) 3401 return err_param->cause; 3402 else 3403 return SCTP_ERROR_INV_PARAM; 3404 break; 3405 default: 3406 return SCTP_ERROR_INV_PARAM; 3407 } 3408 } 3409 3410 length = ntohs(asconf_ack_param->param_hdr.length); 3411 asconf_ack_param = (void *)asconf_ack_param + length; 3412 asconf_ack_len -= length; 3413 } 3414 3415 return err_code; 3416 } 3417 3418 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */ 3419 int sctp_process_asconf_ack(struct sctp_association *asoc, 3420 struct sctp_chunk *asconf_ack) 3421 { 3422 struct sctp_chunk *asconf = asoc->addip_last_asconf; 3423 union sctp_addr_param *addr_param; 3424 sctp_addip_param_t *asconf_param; 3425 int length = 0; 3426 int asconf_len = asconf->skb->len; 3427 int all_param_pass = 0; 3428 int no_err = 1; 3429 int retval = 0; 3430 __be16 err_code = SCTP_ERROR_NO_ERROR; 3431 3432 /* Skip the chunkhdr and addiphdr from the last asconf sent and store 3433 * a pointer to address parameter. 3434 */ 3435 length = sizeof(sctp_addip_chunk_t); 3436 addr_param = (union sctp_addr_param *)(asconf->skb->data + length); 3437 asconf_len -= length; 3438 3439 /* Skip the address parameter in the last asconf sent and store a 3440 * pointer to the first asconf parameter. 3441 */ 3442 length = ntohs(addr_param->p.length); 3443 asconf_param = (void *)addr_param + length; 3444 asconf_len -= length; 3445 3446 /* ADDIP 4.1 3447 * A8) If there is no response(s) to specific TLV parameter(s), and no 3448 * failures are indicated, then all request(s) are considered 3449 * successful. 3450 */ 3451 if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t)) 3452 all_param_pass = 1; 3453 3454 /* Process the TLVs contained in the last sent ASCONF chunk. */ 3455 while (asconf_len > 0) { 3456 if (all_param_pass) 3457 err_code = SCTP_ERROR_NO_ERROR; 3458 else { 3459 err_code = sctp_get_asconf_response(asconf_ack, 3460 asconf_param, 3461 no_err); 3462 if (no_err && (SCTP_ERROR_NO_ERROR != err_code)) 3463 no_err = 0; 3464 } 3465 3466 switch (err_code) { 3467 case SCTP_ERROR_NO_ERROR: 3468 sctp_asconf_param_success(asoc, asconf_param); 3469 break; 3470 3471 case SCTP_ERROR_RSRC_LOW: 3472 retval = 1; 3473 break; 3474 3475 case SCTP_ERROR_UNKNOWN_PARAM: 3476 /* Disable sending this type of asconf parameter in 3477 * future. 3478 */ 3479 asoc->peer.addip_disabled_mask |= 3480 asconf_param->param_hdr.type; 3481 break; 3482 3483 case SCTP_ERROR_REQ_REFUSED: 3484 case SCTP_ERROR_DEL_LAST_IP: 3485 case SCTP_ERROR_DEL_SRC_IP: 3486 default: 3487 break; 3488 } 3489 3490 /* Skip the processed asconf parameter and move to the next 3491 * one. 3492 */ 3493 length = ntohs(asconf_param->param_hdr.length); 3494 asconf_param = (void *)asconf_param + length; 3495 asconf_len -= length; 3496 } 3497 3498 if (no_err && asoc->src_out_of_asoc_ok) { 3499 asoc->src_out_of_asoc_ok = 0; 3500 sctp_transport_immediate_rtx(asoc->peer.primary_path); 3501 } 3502 3503 /* Free the cached last sent asconf chunk. */ 3504 list_del_init(&asconf->transmitted_list); 3505 sctp_chunk_free(asconf); 3506 asoc->addip_last_asconf = NULL; 3507 3508 return retval; 3509 } 3510 3511 /* Make a FWD TSN chunk. */ 3512 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc, 3513 __u32 new_cum_tsn, size_t nstreams, 3514 struct sctp_fwdtsn_skip *skiplist) 3515 { 3516 struct sctp_chunk *retval = NULL; 3517 struct sctp_fwdtsn_hdr ftsn_hdr; 3518 struct sctp_fwdtsn_skip skip; 3519 size_t hint; 3520 int i; 3521 3522 hint = (nstreams + 1) * sizeof(__u32); 3523 3524 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC); 3525 3526 if (!retval) 3527 return NULL; 3528 3529 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn); 3530 retval->subh.fwdtsn_hdr = 3531 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr); 3532 3533 for (i = 0; i < nstreams; i++) { 3534 skip.stream = skiplist[i].stream; 3535 skip.ssn = skiplist[i].ssn; 3536 sctp_addto_chunk(retval, sizeof(skip), &skip); 3537 } 3538 3539 return retval; 3540 } 3541