| 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 | * Copyright (c) 2002 Nokia Corp. |
| 7 | * |
| 8 | * This is part of the SCTP Linux Kernel Implementation. |
| 9 | * |
| 10 | * These are the state functions for the state machine. |
| 11 | * |
| 12 | * This SCTP implementation is free software; |
| 13 | * you can redistribute it and/or modify it under the terms of |
| 14 | * the GNU General Public License as published by |
| 15 | * the Free Software Foundation; either version 2, or (at your option) |
| 16 | * any later version. |
| 17 | * |
| 18 | * This SCTP implementation is distributed in the hope that it |
| 19 | * will be useful, but WITHOUT ANY WARRANTY; without even the implied |
| 20 | * ************************ |
| 21 | * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| 22 | * See the GNU General Public License for more details. |
| 23 | * |
| 24 | * You should have received a copy of the GNU General Public License |
| 25 | * along with GNU CC; see the file COPYING. If not, write to |
| 26 | * the Free Software Foundation, 59 Temple Place - Suite 330, |
| 27 | * Boston, MA 02111-1307, USA. |
| 28 | * |
| 29 | * Please send any bug reports or fixes you make to the |
| 30 | * email address(es): |
| 31 | * lksctp developers <lksctp-developers@lists.sourceforge.net> |
| 32 | * |
| 33 | * Or submit a bug report through the following website: |
| 34 | * http://www.sf.net/projects/lksctp |
| 35 | * |
| 36 | * Written or modified by: |
| 37 | * La Monte H.P. Yarroll <piggy@acm.org> |
| 38 | * Karl Knutson <karl@athena.chicago.il.us> |
| 39 | * Mathew Kotowsky <kotowsky@sctp.org> |
| 40 | * Sridhar Samudrala <samudrala@us.ibm.com> |
| 41 | * Jon Grimm <jgrimm@us.ibm.com> |
| 42 | * Hui Huang <hui.huang@nokia.com> |
| 43 | * Dajiang Zhang <dajiang.zhang@nokia.com> |
| 44 | * Daisy Chang <daisyc@us.ibm.com> |
| 45 | * Ardelle Fan <ardelle.fan@intel.com> |
| 46 | * Ryan Layer <rmlayer@us.ibm.com> |
| 47 | * Kevin Gao <kevin.gao@intel.com> |
| 48 | * |
| 49 | * Any bugs reported given to us we will try to fix... any fixes shared will |
| 50 | * be incorporated into the next SCTP release. |
| 51 | */ |
| 52 | |
| 53 | #include <linux/types.h> |
| 54 | #include <linux/kernel.h> |
| 55 | #include <linux/ip.h> |
| 56 | #include <linux/ipv6.h> |
| 57 | #include <linux/net.h> |
| 58 | #include <linux/inet.h> |
| 59 | #include <net/sock.h> |
| 60 | #include <net/inet_ecn.h> |
| 61 | #include <linux/skbuff.h> |
| 62 | #include <net/sctp/sctp.h> |
| 63 | #include <net/sctp/sm.h> |
| 64 | #include <net/sctp/structs.h> |
| 65 | |
| 66 | static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep, |
| 67 | const struct sctp_association *asoc, |
| 68 | struct sctp_chunk *chunk, |
| 69 | const void *payload, |
| 70 | size_t paylen); |
| 71 | static int sctp_eat_data(const struct sctp_association *asoc, |
| 72 | struct sctp_chunk *chunk, |
| 73 | sctp_cmd_seq_t *commands); |
| 74 | static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc, |
| 75 | const struct sctp_chunk *chunk); |
| 76 | static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep, |
| 77 | const struct sctp_association *asoc, |
| 78 | const struct sctp_chunk *chunk, |
| 79 | sctp_cmd_seq_t *commands, |
| 80 | struct sctp_chunk *err_chunk); |
| 81 | static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep, |
| 82 | const struct sctp_association *asoc, |
| 83 | const sctp_subtype_t type, |
| 84 | void *arg, |
| 85 | sctp_cmd_seq_t *commands); |
| 86 | static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep, |
| 87 | const struct sctp_association *asoc, |
| 88 | const sctp_subtype_t type, |
| 89 | void *arg, |
| 90 | sctp_cmd_seq_t *commands); |
| 91 | static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep, |
| 92 | const struct sctp_association *asoc, |
| 93 | const sctp_subtype_t type, |
| 94 | void *arg, |
| 95 | sctp_cmd_seq_t *commands); |
| 96 | static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk); |
| 97 | |
| 98 | static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands, |
| 99 | __be16 error, int sk_err, |
| 100 | const struct sctp_association *asoc, |
| 101 | struct sctp_transport *transport); |
| 102 | |
| 103 | static sctp_disposition_t sctp_sf_abort_violation( |
| 104 | const struct sctp_endpoint *ep, |
| 105 | const struct sctp_association *asoc, |
| 106 | void *arg, |
| 107 | sctp_cmd_seq_t *commands, |
| 108 | const __u8 *payload, |
| 109 | const size_t paylen); |
| 110 | |
| 111 | static sctp_disposition_t sctp_sf_violation_chunklen( |
| 112 | const struct sctp_endpoint *ep, |
| 113 | const struct sctp_association *asoc, |
| 114 | const sctp_subtype_t type, |
| 115 | void *arg, |
| 116 | sctp_cmd_seq_t *commands); |
| 117 | |
| 118 | static sctp_disposition_t sctp_sf_violation_paramlen( |
| 119 | const struct sctp_endpoint *ep, |
| 120 | const struct sctp_association *asoc, |
| 121 | const sctp_subtype_t type, |
| 122 | void *arg, |
| 123 | sctp_cmd_seq_t *commands); |
| 124 | |
| 125 | static sctp_disposition_t sctp_sf_violation_ctsn( |
| 126 | const struct sctp_endpoint *ep, |
| 127 | const struct sctp_association *asoc, |
| 128 | const sctp_subtype_t type, |
| 129 | void *arg, |
| 130 | sctp_cmd_seq_t *commands); |
| 131 | |
| 132 | static sctp_disposition_t sctp_sf_violation_chunk( |
| 133 | const struct sctp_endpoint *ep, |
| 134 | const struct sctp_association *asoc, |
| 135 | const sctp_subtype_t type, |
| 136 | void *arg, |
| 137 | sctp_cmd_seq_t *commands); |
| 138 | |
| 139 | static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep, |
| 140 | const struct sctp_association *asoc, |
| 141 | const sctp_subtype_t type, |
| 142 | struct sctp_chunk *chunk); |
| 143 | |
| 144 | static sctp_disposition_t __sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep, |
| 145 | const struct sctp_association *asoc, |
| 146 | const sctp_subtype_t type, |
| 147 | void *arg, |
| 148 | sctp_cmd_seq_t *commands); |
| 149 | |
| 150 | /* Small helper function that checks if the chunk length |
| 151 | * is of the appropriate length. The 'required_length' argument |
| 152 | * is set to be the size of a specific chunk we are testing. |
| 153 | * Return Values: 1 = Valid length |
| 154 | * 0 = Invalid length |
| 155 | * |
| 156 | */ |
| 157 | static inline int |
| 158 | sctp_chunk_length_valid(struct sctp_chunk *chunk, |
| 159 | __u16 required_length) |
| 160 | { |
| 161 | __u16 chunk_length = ntohs(chunk->chunk_hdr->length); |
| 162 | |
| 163 | if (unlikely(chunk_length < required_length)) |
| 164 | return 0; |
| 165 | |
| 166 | return 1; |
| 167 | } |
| 168 | |
| 169 | /********************************************************** |
| 170 | * These are the state functions for handling chunk events. |
| 171 | **********************************************************/ |
| 172 | |
| 173 | /* |
| 174 | * Process the final SHUTDOWN COMPLETE. |
| 175 | * |
| 176 | * Section: 4 (C) (diagram), 9.2 |
| 177 | * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify |
| 178 | * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be |
| 179 | * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint |
| 180 | * should stop the T2-shutdown timer and remove all knowledge of the |
| 181 | * association (and thus the association enters the CLOSED state). |
| 182 | * |
| 183 | * Verification Tag: 8.5.1(C), sctpimpguide 2.41. |
| 184 | * C) Rules for packet carrying SHUTDOWN COMPLETE: |
| 185 | * ... |
| 186 | * - The receiver of a SHUTDOWN COMPLETE shall accept the packet |
| 187 | * if the Verification Tag field of the packet matches its own tag and |
| 188 | * the T bit is not set |
| 189 | * OR |
| 190 | * it is set to its peer's tag and the T bit is set in the Chunk |
| 191 | * Flags. |
| 192 | * Otherwise, the receiver MUST silently discard the packet |
| 193 | * and take no further action. An endpoint MUST ignore the |
| 194 | * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state. |
| 195 | * |
| 196 | * Inputs |
| 197 | * (endpoint, asoc, chunk) |
| 198 | * |
| 199 | * Outputs |
| 200 | * (asoc, reply_msg, msg_up, timers, counters) |
| 201 | * |
| 202 | * The return value is the disposition of the chunk. |
| 203 | */ |
| 204 | sctp_disposition_t sctp_sf_do_4_C(const struct sctp_endpoint *ep, |
| 205 | const struct sctp_association *asoc, |
| 206 | const sctp_subtype_t type, |
| 207 | void *arg, |
| 208 | sctp_cmd_seq_t *commands) |
| 209 | { |
| 210 | struct sctp_chunk *chunk = arg; |
| 211 | struct sctp_ulpevent *ev; |
| 212 | |
| 213 | if (!sctp_vtag_verify_either(chunk, asoc)) |
| 214 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 215 | |
| 216 | /* RFC 2960 6.10 Bundling |
| 217 | * |
| 218 | * An endpoint MUST NOT bundle INIT, INIT ACK or |
| 219 | * SHUTDOWN COMPLETE with any other chunks. |
| 220 | */ |
| 221 | if (!chunk->singleton) |
| 222 | return sctp_sf_violation_chunk(ep, asoc, type, arg, commands); |
| 223 | |
| 224 | /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */ |
| 225 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
| 226 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 227 | commands); |
| 228 | |
| 229 | /* RFC 2960 10.2 SCTP-to-ULP |
| 230 | * |
| 231 | * H) SHUTDOWN COMPLETE notification |
| 232 | * |
| 233 | * When SCTP completes the shutdown procedures (section 9.2) this |
| 234 | * notification is passed to the upper layer. |
| 235 | */ |
| 236 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP, |
| 237 | 0, 0, 0, NULL, GFP_ATOMIC); |
| 238 | if (ev) |
| 239 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
| 240 | SCTP_ULPEVENT(ev)); |
| 241 | |
| 242 | /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint |
| 243 | * will verify that it is in SHUTDOWN-ACK-SENT state, if it is |
| 244 | * not the chunk should be discarded. If the endpoint is in |
| 245 | * the SHUTDOWN-ACK-SENT state the endpoint should stop the |
| 246 | * T2-shutdown timer and remove all knowledge of the |
| 247 | * association (and thus the association enters the CLOSED |
| 248 | * state). |
| 249 | */ |
| 250 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| 251 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
| 252 | |
| 253 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| 254 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
| 255 | |
| 256 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| 257 | SCTP_STATE(SCTP_STATE_CLOSED)); |
| 258 | |
| 259 | SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS); |
| 260 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); |
| 261 | |
| 262 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
| 263 | |
| 264 | return SCTP_DISPOSITION_DELETE_TCB; |
| 265 | } |
| 266 | |
| 267 | /* |
| 268 | * Respond to a normal INIT chunk. |
| 269 | * We are the side that is being asked for an association. |
| 270 | * |
| 271 | * Section: 5.1 Normal Establishment of an Association, B |
| 272 | * B) "Z" shall respond immediately with an INIT ACK chunk. The |
| 273 | * destination IP address of the INIT ACK MUST be set to the source |
| 274 | * IP address of the INIT to which this INIT ACK is responding. In |
| 275 | * the response, besides filling in other parameters, "Z" must set the |
| 276 | * Verification Tag field to Tag_A, and also provide its own |
| 277 | * Verification Tag (Tag_Z) in the Initiate Tag field. |
| 278 | * |
| 279 | * Verification Tag: Must be 0. |
| 280 | * |
| 281 | * Inputs |
| 282 | * (endpoint, asoc, chunk) |
| 283 | * |
| 284 | * Outputs |
| 285 | * (asoc, reply_msg, msg_up, timers, counters) |
| 286 | * |
| 287 | * The return value is the disposition of the chunk. |
| 288 | */ |
| 289 | sctp_disposition_t sctp_sf_do_5_1B_init(const struct sctp_endpoint *ep, |
| 290 | const struct sctp_association *asoc, |
| 291 | const sctp_subtype_t type, |
| 292 | void *arg, |
| 293 | sctp_cmd_seq_t *commands) |
| 294 | { |
| 295 | struct sctp_chunk *chunk = arg; |
| 296 | struct sctp_chunk *repl; |
| 297 | struct sctp_association *new_asoc; |
| 298 | struct sctp_chunk *err_chunk; |
| 299 | struct sctp_packet *packet; |
| 300 | sctp_unrecognized_param_t *unk_param; |
| 301 | int len; |
| 302 | |
| 303 | /* 6.10 Bundling |
| 304 | * An endpoint MUST NOT bundle INIT, INIT ACK or |
| 305 | * SHUTDOWN COMPLETE with any other chunks. |
| 306 | * |
| 307 | * IG Section 2.11.2 |
| 308 | * Furthermore, we require that the receiver of an INIT chunk MUST |
| 309 | * enforce these rules by silently discarding an arriving packet |
| 310 | * with an INIT chunk that is bundled with other chunks. |
| 311 | */ |
| 312 | if (!chunk->singleton) |
| 313 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 314 | |
| 315 | /* If the packet is an OOTB packet which is temporarily on the |
| 316 | * control endpoint, respond with an ABORT. |
| 317 | */ |
| 318 | if (ep == sctp_sk((sctp_get_ctl_sock()))->ep) |
| 319 | return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands); |
| 320 | |
| 321 | /* 3.1 A packet containing an INIT chunk MUST have a zero Verification |
| 322 | * Tag. |
| 323 | */ |
| 324 | if (chunk->sctp_hdr->vtag != 0) |
| 325 | return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands); |
| 326 | |
| 327 | /* Make sure that the INIT chunk has a valid length. |
| 328 | * Normally, this would cause an ABORT with a Protocol Violation |
| 329 | * error, but since we don't have an association, we'll |
| 330 | * just discard the packet. |
| 331 | */ |
| 332 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t))) |
| 333 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 334 | |
| 335 | /* Verify the INIT chunk before processing it. */ |
| 336 | err_chunk = NULL; |
| 337 | if (!sctp_verify_init(asoc, chunk->chunk_hdr->type, |
| 338 | (sctp_init_chunk_t *)chunk->chunk_hdr, chunk, |
| 339 | &err_chunk)) { |
| 340 | /* This chunk contains fatal error. It is to be discarded. |
| 341 | * Send an ABORT, with causes if there is any. |
| 342 | */ |
| 343 | if (err_chunk) { |
| 344 | packet = sctp_abort_pkt_new(ep, asoc, arg, |
| 345 | (__u8 *)(err_chunk->chunk_hdr) + |
| 346 | sizeof(sctp_chunkhdr_t), |
| 347 | ntohs(err_chunk->chunk_hdr->length) - |
| 348 | sizeof(sctp_chunkhdr_t)); |
| 349 | |
| 350 | sctp_chunk_free(err_chunk); |
| 351 | |
| 352 | if (packet) { |
| 353 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
| 354 | SCTP_PACKET(packet)); |
| 355 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
| 356 | return SCTP_DISPOSITION_CONSUME; |
| 357 | } else { |
| 358 | return SCTP_DISPOSITION_NOMEM; |
| 359 | } |
| 360 | } else { |
| 361 | return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, |
| 362 | commands); |
| 363 | } |
| 364 | } |
| 365 | |
| 366 | /* Grab the INIT header. */ |
| 367 | chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data; |
| 368 | |
| 369 | /* Tag the variable length parameters. */ |
| 370 | chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t)); |
| 371 | |
| 372 | new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC); |
| 373 | if (!new_asoc) |
| 374 | goto nomem; |
| 375 | |
| 376 | /* The call, sctp_process_init(), can fail on memory allocation. */ |
| 377 | if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type, |
| 378 | sctp_source(chunk), |
| 379 | (sctp_init_chunk_t *)chunk->chunk_hdr, |
| 380 | GFP_ATOMIC)) |
| 381 | goto nomem_init; |
| 382 | |
| 383 | /* B) "Z" shall respond immediately with an INIT ACK chunk. */ |
| 384 | |
| 385 | /* If there are errors need to be reported for unknown parameters, |
| 386 | * make sure to reserve enough room in the INIT ACK for them. |
| 387 | */ |
| 388 | len = 0; |
| 389 | if (err_chunk) |
| 390 | len = ntohs(err_chunk->chunk_hdr->length) - |
| 391 | sizeof(sctp_chunkhdr_t); |
| 392 | |
| 393 | if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0) |
| 394 | goto nomem_init; |
| 395 | |
| 396 | repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len); |
| 397 | if (!repl) |
| 398 | goto nomem_init; |
| 399 | |
| 400 | /* If there are errors need to be reported for unknown parameters, |
| 401 | * include them in the outgoing INIT ACK as "Unrecognized parameter" |
| 402 | * parameter. |
| 403 | */ |
| 404 | if (err_chunk) { |
| 405 | /* Get the "Unrecognized parameter" parameter(s) out of the |
| 406 | * ERROR chunk generated by sctp_verify_init(). Since the |
| 407 | * error cause code for "unknown parameter" and the |
| 408 | * "Unrecognized parameter" type is the same, we can |
| 409 | * construct the parameters in INIT ACK by copying the |
| 410 | * ERROR causes over. |
| 411 | */ |
| 412 | unk_param = (sctp_unrecognized_param_t *) |
| 413 | ((__u8 *)(err_chunk->chunk_hdr) + |
| 414 | sizeof(sctp_chunkhdr_t)); |
| 415 | /* Replace the cause code with the "Unrecognized parameter" |
| 416 | * parameter type. |
| 417 | */ |
| 418 | sctp_addto_chunk(repl, len, unk_param); |
| 419 | sctp_chunk_free(err_chunk); |
| 420 | } |
| 421 | |
| 422 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc)); |
| 423 | |
| 424 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
| 425 | |
| 426 | /* |
| 427 | * Note: After sending out INIT ACK with the State Cookie parameter, |
| 428 | * "Z" MUST NOT allocate any resources, nor keep any states for the |
| 429 | * new association. Otherwise, "Z" will be vulnerable to resource |
| 430 | * attacks. |
| 431 | */ |
| 432 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
| 433 | |
| 434 | return SCTP_DISPOSITION_DELETE_TCB; |
| 435 | |
| 436 | nomem_init: |
| 437 | sctp_association_free(new_asoc); |
| 438 | nomem: |
| 439 | if (err_chunk) |
| 440 | sctp_chunk_free(err_chunk); |
| 441 | return SCTP_DISPOSITION_NOMEM; |
| 442 | } |
| 443 | |
| 444 | /* |
| 445 | * Respond to a normal INIT ACK chunk. |
| 446 | * We are the side that is initiating the association. |
| 447 | * |
| 448 | * Section: 5.1 Normal Establishment of an Association, C |
| 449 | * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init |
| 450 | * timer and leave COOKIE-WAIT state. "A" shall then send the State |
| 451 | * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start |
| 452 | * the T1-cookie timer, and enter the COOKIE-ECHOED state. |
| 453 | * |
| 454 | * Note: The COOKIE ECHO chunk can be bundled with any pending outbound |
| 455 | * DATA chunks, but it MUST be the first chunk in the packet and |
| 456 | * until the COOKIE ACK is returned the sender MUST NOT send any |
| 457 | * other packets to the peer. |
| 458 | * |
| 459 | * Verification Tag: 3.3.3 |
| 460 | * If the value of the Initiate Tag in a received INIT ACK chunk is |
| 461 | * found to be 0, the receiver MUST treat it as an error and close the |
| 462 | * association by transmitting an ABORT. |
| 463 | * |
| 464 | * Inputs |
| 465 | * (endpoint, asoc, chunk) |
| 466 | * |
| 467 | * Outputs |
| 468 | * (asoc, reply_msg, msg_up, timers, counters) |
| 469 | * |
| 470 | * The return value is the disposition of the chunk. |
| 471 | */ |
| 472 | sctp_disposition_t sctp_sf_do_5_1C_ack(const struct sctp_endpoint *ep, |
| 473 | const struct sctp_association *asoc, |
| 474 | const sctp_subtype_t type, |
| 475 | void *arg, |
| 476 | sctp_cmd_seq_t *commands) |
| 477 | { |
| 478 | struct sctp_chunk *chunk = arg; |
| 479 | sctp_init_chunk_t *initchunk; |
| 480 | struct sctp_chunk *err_chunk; |
| 481 | struct sctp_packet *packet; |
| 482 | |
| 483 | if (!sctp_vtag_verify(chunk, asoc)) |
| 484 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 485 | |
| 486 | /* 6.10 Bundling |
| 487 | * An endpoint MUST NOT bundle INIT, INIT ACK or |
| 488 | * SHUTDOWN COMPLETE with any other chunks. |
| 489 | */ |
| 490 | if (!chunk->singleton) |
| 491 | return sctp_sf_violation_chunk(ep, asoc, type, arg, commands); |
| 492 | |
| 493 | /* Make sure that the INIT-ACK chunk has a valid length */ |
| 494 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t))) |
| 495 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 496 | commands); |
| 497 | /* Grab the INIT header. */ |
| 498 | chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data; |
| 499 | |
| 500 | /* Verify the INIT chunk before processing it. */ |
| 501 | err_chunk = NULL; |
| 502 | if (!sctp_verify_init(asoc, chunk->chunk_hdr->type, |
| 503 | (sctp_init_chunk_t *)chunk->chunk_hdr, chunk, |
| 504 | &err_chunk)) { |
| 505 | |
| 506 | sctp_error_t error = SCTP_ERROR_NO_RESOURCE; |
| 507 | |
| 508 | /* This chunk contains fatal error. It is to be discarded. |
| 509 | * Send an ABORT, with causes. If there are no causes, |
| 510 | * then there wasn't enough memory. Just terminate |
| 511 | * the association. |
| 512 | */ |
| 513 | if (err_chunk) { |
| 514 | packet = sctp_abort_pkt_new(ep, asoc, arg, |
| 515 | (__u8 *)(err_chunk->chunk_hdr) + |
| 516 | sizeof(sctp_chunkhdr_t), |
| 517 | ntohs(err_chunk->chunk_hdr->length) - |
| 518 | sizeof(sctp_chunkhdr_t)); |
| 519 | |
| 520 | sctp_chunk_free(err_chunk); |
| 521 | |
| 522 | if (packet) { |
| 523 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
| 524 | SCTP_PACKET(packet)); |
| 525 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
| 526 | error = SCTP_ERROR_INV_PARAM; |
| 527 | } |
| 528 | } |
| 529 | |
| 530 | /* SCTP-AUTH, Section 6.3: |
| 531 | * It should be noted that if the receiver wants to tear |
| 532 | * down an association in an authenticated way only, the |
| 533 | * handling of malformed packets should not result in |
| 534 | * tearing down the association. |
| 535 | * |
| 536 | * This means that if we only want to abort associations |
| 537 | * in an authenticated way (i.e AUTH+ABORT), then we |
| 538 | * can't destroy this association just becuase the packet |
| 539 | * was malformed. |
| 540 | */ |
| 541 | if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc)) |
| 542 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 543 | |
| 544 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
| 545 | return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED, |
| 546 | asoc, chunk->transport); |
| 547 | } |
| 548 | |
| 549 | /* Tag the variable length parameters. Note that we never |
| 550 | * convert the parameters in an INIT chunk. |
| 551 | */ |
| 552 | chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t)); |
| 553 | |
| 554 | initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr; |
| 555 | |
| 556 | sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT, |
| 557 | SCTP_PEER_INIT(initchunk)); |
| 558 | |
| 559 | /* Reset init error count upon receipt of INIT-ACK. */ |
| 560 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL()); |
| 561 | |
| 562 | /* 5.1 C) "A" shall stop the T1-init timer and leave |
| 563 | * COOKIE-WAIT state. "A" shall then ... start the T1-cookie |
| 564 | * timer, and enter the COOKIE-ECHOED state. |
| 565 | */ |
| 566 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| 567 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
| 568 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
| 569 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); |
| 570 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| 571 | SCTP_STATE(SCTP_STATE_COOKIE_ECHOED)); |
| 572 | |
| 573 | /* SCTP-AUTH: genereate the assocition shared keys so that |
| 574 | * we can potentially signe the COOKIE-ECHO. |
| 575 | */ |
| 576 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL()); |
| 577 | |
| 578 | /* 5.1 C) "A" shall then send the State Cookie received in the |
| 579 | * INIT ACK chunk in a COOKIE ECHO chunk, ... |
| 580 | */ |
| 581 | /* If there is any errors to report, send the ERROR chunk generated |
| 582 | * for unknown parameters as well. |
| 583 | */ |
| 584 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO, |
| 585 | SCTP_CHUNK(err_chunk)); |
| 586 | |
| 587 | return SCTP_DISPOSITION_CONSUME; |
| 588 | } |
| 589 | |
| 590 | /* |
| 591 | * Respond to a normal COOKIE ECHO chunk. |
| 592 | * We are the side that is being asked for an association. |
| 593 | * |
| 594 | * Section: 5.1 Normal Establishment of an Association, D |
| 595 | * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply |
| 596 | * with a COOKIE ACK chunk after building a TCB and moving to |
| 597 | * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with |
| 598 | * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK |
| 599 | * chunk MUST be the first chunk in the packet. |
| 600 | * |
| 601 | * IMPLEMENTATION NOTE: An implementation may choose to send the |
| 602 | * Communication Up notification to the SCTP user upon reception |
| 603 | * of a valid COOKIE ECHO chunk. |
| 604 | * |
| 605 | * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules |
| 606 | * D) Rules for packet carrying a COOKIE ECHO |
| 607 | * |
| 608 | * - When sending a COOKIE ECHO, the endpoint MUST use the value of the |
| 609 | * Initial Tag received in the INIT ACK. |
| 610 | * |
| 611 | * - The receiver of a COOKIE ECHO follows the procedures in Section 5. |
| 612 | * |
| 613 | * Inputs |
| 614 | * (endpoint, asoc, chunk) |
| 615 | * |
| 616 | * Outputs |
| 617 | * (asoc, reply_msg, msg_up, timers, counters) |
| 618 | * |
| 619 | * The return value is the disposition of the chunk. |
| 620 | */ |
| 621 | sctp_disposition_t sctp_sf_do_5_1D_ce(const struct sctp_endpoint *ep, |
| 622 | const struct sctp_association *asoc, |
| 623 | const sctp_subtype_t type, void *arg, |
| 624 | sctp_cmd_seq_t *commands) |
| 625 | { |
| 626 | struct sctp_chunk *chunk = arg; |
| 627 | struct sctp_association *new_asoc; |
| 628 | sctp_init_chunk_t *peer_init; |
| 629 | struct sctp_chunk *repl; |
| 630 | struct sctp_ulpevent *ev, *ai_ev = NULL; |
| 631 | int error = 0; |
| 632 | struct sctp_chunk *err_chk_p; |
| 633 | struct sock *sk; |
| 634 | |
| 635 | /* If the packet is an OOTB packet which is temporarily on the |
| 636 | * control endpoint, respond with an ABORT. |
| 637 | */ |
| 638 | if (ep == sctp_sk((sctp_get_ctl_sock()))->ep) |
| 639 | return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands); |
| 640 | |
| 641 | /* Make sure that the COOKIE_ECHO chunk has a valid length. |
| 642 | * In this case, we check that we have enough for at least a |
| 643 | * chunk header. More detailed verification is done |
| 644 | * in sctp_unpack_cookie(). |
| 645 | */ |
| 646 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
| 647 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 648 | |
| 649 | /* If the endpoint is not listening or if the number of associations |
| 650 | * on the TCP-style socket exceed the max backlog, respond with an |
| 651 | * ABORT. |
| 652 | */ |
| 653 | sk = ep->base.sk; |
| 654 | if (!sctp_sstate(sk, LISTENING) || |
| 655 | (sctp_style(sk, TCP) && sk_acceptq_is_full(sk))) |
| 656 | return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands); |
| 657 | |
| 658 | /* "Decode" the chunk. We have no optional parameters so we |
| 659 | * are in good shape. |
| 660 | */ |
| 661 | chunk->subh.cookie_hdr = |
| 662 | (struct sctp_signed_cookie *)chunk->skb->data; |
| 663 | if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) - |
| 664 | sizeof(sctp_chunkhdr_t))) |
| 665 | goto nomem; |
| 666 | |
| 667 | /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint |
| 668 | * "Z" will reply with a COOKIE ACK chunk after building a TCB |
| 669 | * and moving to the ESTABLISHED state. |
| 670 | */ |
| 671 | new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error, |
| 672 | &err_chk_p); |
| 673 | |
| 674 | /* FIXME: |
| 675 | * If the re-build failed, what is the proper error path |
| 676 | * from here? |
| 677 | * |
| 678 | * [We should abort the association. --piggy] |
| 679 | */ |
| 680 | if (!new_asoc) { |
| 681 | /* FIXME: Several errors are possible. A bad cookie should |
| 682 | * be silently discarded, but think about logging it too. |
| 683 | */ |
| 684 | switch (error) { |
| 685 | case -SCTP_IERROR_NOMEM: |
| 686 | goto nomem; |
| 687 | |
| 688 | case -SCTP_IERROR_STALE_COOKIE: |
| 689 | sctp_send_stale_cookie_err(ep, asoc, chunk, commands, |
| 690 | err_chk_p); |
| 691 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 692 | |
| 693 | case -SCTP_IERROR_BAD_SIG: |
| 694 | default: |
| 695 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 696 | } |
| 697 | } |
| 698 | |
| 699 | |
| 700 | /* Delay state machine commands until later. |
| 701 | * |
| 702 | * Re-build the bind address for the association is done in |
| 703 | * the sctp_unpack_cookie() already. |
| 704 | */ |
| 705 | /* This is a brand-new association, so these are not yet side |
| 706 | * effects--it is safe to run them here. |
| 707 | */ |
| 708 | peer_init = &chunk->subh.cookie_hdr->c.peer_init[0]; |
| 709 | |
| 710 | if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type, |
| 711 | &chunk->subh.cookie_hdr->c.peer_addr, |
| 712 | peer_init, GFP_ATOMIC)) |
| 713 | goto nomem_init; |
| 714 | |
| 715 | /* SCTP-AUTH: Now that we've populate required fields in |
| 716 | * sctp_process_init, set up the assocaition shared keys as |
| 717 | * necessary so that we can potentially authenticate the ACK |
| 718 | */ |
| 719 | error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC); |
| 720 | if (error) |
| 721 | goto nomem_init; |
| 722 | |
| 723 | /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo |
| 724 | * is supposed to be authenticated and we have to do delayed |
| 725 | * authentication. We've just recreated the association using |
| 726 | * the information in the cookie and now it's much easier to |
| 727 | * do the authentication. |
| 728 | */ |
| 729 | if (chunk->auth_chunk) { |
| 730 | struct sctp_chunk auth; |
| 731 | sctp_ierror_t ret; |
| 732 | |
| 733 | /* set-up our fake chunk so that we can process it */ |
| 734 | auth.skb = chunk->auth_chunk; |
| 735 | auth.asoc = chunk->asoc; |
| 736 | auth.sctp_hdr = chunk->sctp_hdr; |
| 737 | auth.chunk_hdr = (sctp_chunkhdr_t *)skb_push(chunk->auth_chunk, |
| 738 | sizeof(sctp_chunkhdr_t)); |
| 739 | skb_pull(chunk->auth_chunk, sizeof(sctp_chunkhdr_t)); |
| 740 | auth.transport = chunk->transport; |
| 741 | |
| 742 | ret = sctp_sf_authenticate(ep, new_asoc, type, &auth); |
| 743 | |
| 744 | /* We can now safely free the auth_chunk clone */ |
| 745 | kfree_skb(chunk->auth_chunk); |
| 746 | |
| 747 | if (ret != SCTP_IERROR_NO_ERROR) { |
| 748 | sctp_association_free(new_asoc); |
| 749 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 750 | } |
| 751 | } |
| 752 | |
| 753 | repl = sctp_make_cookie_ack(new_asoc, chunk); |
| 754 | if (!repl) |
| 755 | goto nomem_init; |
| 756 | |
| 757 | /* RFC 2960 5.1 Normal Establishment of an Association |
| 758 | * |
| 759 | * D) IMPLEMENTATION NOTE: An implementation may choose to |
| 760 | * send the Communication Up notification to the SCTP user |
| 761 | * upon reception of a valid COOKIE ECHO chunk. |
| 762 | */ |
| 763 | ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0, |
| 764 | new_asoc->c.sinit_num_ostreams, |
| 765 | new_asoc->c.sinit_max_instreams, |
| 766 | NULL, GFP_ATOMIC); |
| 767 | if (!ev) |
| 768 | goto nomem_ev; |
| 769 | |
| 770 | /* Sockets API Draft Section 5.3.1.6 |
| 771 | * When a peer sends a Adaptation Layer Indication parameter , SCTP |
| 772 | * delivers this notification to inform the application that of the |
| 773 | * peers requested adaptation layer. |
| 774 | */ |
| 775 | if (new_asoc->peer.adaptation_ind) { |
| 776 | ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc, |
| 777 | GFP_ATOMIC); |
| 778 | if (!ai_ev) |
| 779 | goto nomem_aiev; |
| 780 | } |
| 781 | |
| 782 | /* Add all the state machine commands now since we've created |
| 783 | * everything. This way we don't introduce memory corruptions |
| 784 | * during side-effect processing and correclty count established |
| 785 | * associations. |
| 786 | */ |
| 787 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc)); |
| 788 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| 789 | SCTP_STATE(SCTP_STATE_ESTABLISHED)); |
| 790 | SCTP_INC_STATS(SCTP_MIB_CURRESTAB); |
| 791 | SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS); |
| 792 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL()); |
| 793 | |
| 794 | if (new_asoc->autoclose) |
| 795 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
| 796 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
| 797 | |
| 798 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL()); |
| 799 | |
| 800 | /* This will send the COOKIE ACK */ |
| 801 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
| 802 | |
| 803 | /* Queue the ASSOC_CHANGE event */ |
| 804 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); |
| 805 | |
| 806 | /* Send up the Adaptation Layer Indication event */ |
| 807 | if (ai_ev) |
| 808 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
| 809 | SCTP_ULPEVENT(ai_ev)); |
| 810 | |
| 811 | return SCTP_DISPOSITION_CONSUME; |
| 812 | |
| 813 | nomem_aiev: |
| 814 | sctp_ulpevent_free(ev); |
| 815 | nomem_ev: |
| 816 | sctp_chunk_free(repl); |
| 817 | nomem_init: |
| 818 | sctp_association_free(new_asoc); |
| 819 | nomem: |
| 820 | return SCTP_DISPOSITION_NOMEM; |
| 821 | } |
| 822 | |
| 823 | /* |
| 824 | * Respond to a normal COOKIE ACK chunk. |
| 825 | * We are the side that is being asked for an association. |
| 826 | * |
| 827 | * RFC 2960 5.1 Normal Establishment of an Association |
| 828 | * |
| 829 | * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the |
| 830 | * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie |
| 831 | * timer. It may also notify its ULP about the successful |
| 832 | * establishment of the association with a Communication Up |
| 833 | * notification (see Section 10). |
| 834 | * |
| 835 | * Verification Tag: |
| 836 | * Inputs |
| 837 | * (endpoint, asoc, chunk) |
| 838 | * |
| 839 | * Outputs |
| 840 | * (asoc, reply_msg, msg_up, timers, counters) |
| 841 | * |
| 842 | * The return value is the disposition of the chunk. |
| 843 | */ |
| 844 | sctp_disposition_t sctp_sf_do_5_1E_ca(const struct sctp_endpoint *ep, |
| 845 | const struct sctp_association *asoc, |
| 846 | const sctp_subtype_t type, void *arg, |
| 847 | sctp_cmd_seq_t *commands) |
| 848 | { |
| 849 | struct sctp_chunk *chunk = arg; |
| 850 | struct sctp_ulpevent *ev; |
| 851 | |
| 852 | if (!sctp_vtag_verify(chunk, asoc)) |
| 853 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 854 | |
| 855 | /* Verify that the chunk length for the COOKIE-ACK is OK. |
| 856 | * If we don't do this, any bundled chunks may be junked. |
| 857 | */ |
| 858 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
| 859 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 860 | commands); |
| 861 | |
| 862 | /* Reset init error count upon receipt of COOKIE-ACK, |
| 863 | * to avoid problems with the managemement of this |
| 864 | * counter in stale cookie situations when a transition back |
| 865 | * from the COOKIE-ECHOED state to the COOKIE-WAIT |
| 866 | * state is performed. |
| 867 | */ |
| 868 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL()); |
| 869 | |
| 870 | /* RFC 2960 5.1 Normal Establishment of an Association |
| 871 | * |
| 872 | * E) Upon reception of the COOKIE ACK, endpoint "A" will move |
| 873 | * from the COOKIE-ECHOED state to the ESTABLISHED state, |
| 874 | * stopping the T1-cookie timer. |
| 875 | */ |
| 876 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| 877 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); |
| 878 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| 879 | SCTP_STATE(SCTP_STATE_ESTABLISHED)); |
| 880 | SCTP_INC_STATS(SCTP_MIB_CURRESTAB); |
| 881 | SCTP_INC_STATS(SCTP_MIB_ACTIVEESTABS); |
| 882 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL()); |
| 883 | if (asoc->autoclose) |
| 884 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
| 885 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
| 886 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL()); |
| 887 | |
| 888 | /* It may also notify its ULP about the successful |
| 889 | * establishment of the association with a Communication Up |
| 890 | * notification (see Section 10). |
| 891 | */ |
| 892 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP, |
| 893 | 0, asoc->c.sinit_num_ostreams, |
| 894 | asoc->c.sinit_max_instreams, |
| 895 | NULL, GFP_ATOMIC); |
| 896 | |
| 897 | if (!ev) |
| 898 | goto nomem; |
| 899 | |
| 900 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); |
| 901 | |
| 902 | /* Sockets API Draft Section 5.3.1.6 |
| 903 | * When a peer sends a Adaptation Layer Indication parameter , SCTP |
| 904 | * delivers this notification to inform the application that of the |
| 905 | * peers requested adaptation layer. |
| 906 | */ |
| 907 | if (asoc->peer.adaptation_ind) { |
| 908 | ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC); |
| 909 | if (!ev) |
| 910 | goto nomem; |
| 911 | |
| 912 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
| 913 | SCTP_ULPEVENT(ev)); |
| 914 | } |
| 915 | |
| 916 | return SCTP_DISPOSITION_CONSUME; |
| 917 | nomem: |
| 918 | return SCTP_DISPOSITION_NOMEM; |
| 919 | } |
| 920 | |
| 921 | /* Generate and sendout a heartbeat packet. */ |
| 922 | static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep, |
| 923 | const struct sctp_association *asoc, |
| 924 | const sctp_subtype_t type, |
| 925 | void *arg, |
| 926 | sctp_cmd_seq_t *commands) |
| 927 | { |
| 928 | struct sctp_transport *transport = (struct sctp_transport *) arg; |
| 929 | struct sctp_chunk *reply; |
| 930 | sctp_sender_hb_info_t hbinfo; |
| 931 | size_t paylen = 0; |
| 932 | |
| 933 | hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO; |
| 934 | hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t)); |
| 935 | hbinfo.daddr = transport->ipaddr; |
| 936 | hbinfo.sent_at = jiffies; |
| 937 | hbinfo.hb_nonce = transport->hb_nonce; |
| 938 | |
| 939 | /* Send a heartbeat to our peer. */ |
| 940 | paylen = sizeof(sctp_sender_hb_info_t); |
| 941 | reply = sctp_make_heartbeat(asoc, transport, &hbinfo, paylen); |
| 942 | if (!reply) |
| 943 | return SCTP_DISPOSITION_NOMEM; |
| 944 | |
| 945 | /* Set rto_pending indicating that an RTT measurement |
| 946 | * is started with this heartbeat chunk. |
| 947 | */ |
| 948 | sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING, |
| 949 | SCTP_TRANSPORT(transport)); |
| 950 | |
| 951 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
| 952 | return SCTP_DISPOSITION_CONSUME; |
| 953 | } |
| 954 | |
| 955 | /* Generate a HEARTBEAT packet on the given transport. */ |
| 956 | sctp_disposition_t sctp_sf_sendbeat_8_3(const struct sctp_endpoint *ep, |
| 957 | const struct sctp_association *asoc, |
| 958 | const sctp_subtype_t type, |
| 959 | void *arg, |
| 960 | sctp_cmd_seq_t *commands) |
| 961 | { |
| 962 | struct sctp_transport *transport = (struct sctp_transport *) arg; |
| 963 | |
| 964 | if (asoc->overall_error_count > asoc->max_retrans) { |
| 965 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| 966 | SCTP_ERROR(ETIMEDOUT)); |
| 967 | /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */ |
| 968 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
| 969 | SCTP_PERR(SCTP_ERROR_NO_ERROR)); |
| 970 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
| 971 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); |
| 972 | return SCTP_DISPOSITION_DELETE_TCB; |
| 973 | } |
| 974 | |
| 975 | /* Section 3.3.5. |
| 976 | * The Sender-specific Heartbeat Info field should normally include |
| 977 | * information about the sender's current time when this HEARTBEAT |
| 978 | * chunk is sent and the destination transport address to which this |
| 979 | * HEARTBEAT is sent (see Section 8.3). |
| 980 | */ |
| 981 | |
| 982 | if (transport->param_flags & SPP_HB_ENABLE) { |
| 983 | if (SCTP_DISPOSITION_NOMEM == |
| 984 | sctp_sf_heartbeat(ep, asoc, type, arg, |
| 985 | commands)) |
| 986 | return SCTP_DISPOSITION_NOMEM; |
| 987 | /* Set transport error counter and association error counter |
| 988 | * when sending heartbeat. |
| 989 | */ |
| 990 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_RESET, |
| 991 | SCTP_TRANSPORT(transport)); |
| 992 | } |
| 993 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE, |
| 994 | SCTP_TRANSPORT(transport)); |
| 995 | |
| 996 | return SCTP_DISPOSITION_CONSUME; |
| 997 | } |
| 998 | |
| 999 | /* |
| 1000 | * Process an heartbeat request. |
| 1001 | * |
| 1002 | * Section: 8.3 Path Heartbeat |
| 1003 | * The receiver of the HEARTBEAT should immediately respond with a |
| 1004 | * HEARTBEAT ACK that contains the Heartbeat Information field copied |
| 1005 | * from the received HEARTBEAT chunk. |
| 1006 | * |
| 1007 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
| 1008 | * When receiving an SCTP packet, the endpoint MUST ensure that the |
| 1009 | * value in the Verification Tag field of the received SCTP packet |
| 1010 | * matches its own Tag. If the received Verification Tag value does not |
| 1011 | * match the receiver's own tag value, the receiver shall silently |
| 1012 | * discard the packet and shall not process it any further except for |
| 1013 | * those cases listed in Section 8.5.1 below. |
| 1014 | * |
| 1015 | * Inputs |
| 1016 | * (endpoint, asoc, chunk) |
| 1017 | * |
| 1018 | * Outputs |
| 1019 | * (asoc, reply_msg, msg_up, timers, counters) |
| 1020 | * |
| 1021 | * The return value is the disposition of the chunk. |
| 1022 | */ |
| 1023 | sctp_disposition_t sctp_sf_beat_8_3(const struct sctp_endpoint *ep, |
| 1024 | const struct sctp_association *asoc, |
| 1025 | const sctp_subtype_t type, |
| 1026 | void *arg, |
| 1027 | sctp_cmd_seq_t *commands) |
| 1028 | { |
| 1029 | struct sctp_chunk *chunk = arg; |
| 1030 | struct sctp_chunk *reply; |
| 1031 | size_t paylen = 0; |
| 1032 | |
| 1033 | if (!sctp_vtag_verify(chunk, asoc)) |
| 1034 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 1035 | |
| 1036 | /* Make sure that the HEARTBEAT chunk has a valid length. */ |
| 1037 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t))) |
| 1038 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 1039 | commands); |
| 1040 | |
| 1041 | /* 8.3 The receiver of the HEARTBEAT should immediately |
| 1042 | * respond with a HEARTBEAT ACK that contains the Heartbeat |
| 1043 | * Information field copied from the received HEARTBEAT chunk. |
| 1044 | */ |
| 1045 | chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data; |
| 1046 | paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t); |
| 1047 | if (!pskb_pull(chunk->skb, paylen)) |
| 1048 | goto nomem; |
| 1049 | |
| 1050 | reply = sctp_make_heartbeat_ack(asoc, chunk, |
| 1051 | chunk->subh.hb_hdr, paylen); |
| 1052 | if (!reply) |
| 1053 | goto nomem; |
| 1054 | |
| 1055 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
| 1056 | return SCTP_DISPOSITION_CONSUME; |
| 1057 | |
| 1058 | nomem: |
| 1059 | return SCTP_DISPOSITION_NOMEM; |
| 1060 | } |
| 1061 | |
| 1062 | /* |
| 1063 | * Process the returning HEARTBEAT ACK. |
| 1064 | * |
| 1065 | * Section: 8.3 Path Heartbeat |
| 1066 | * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT |
| 1067 | * should clear the error counter of the destination transport |
| 1068 | * address to which the HEARTBEAT was sent, and mark the destination |
| 1069 | * transport address as active if it is not so marked. The endpoint may |
| 1070 | * optionally report to the upper layer when an inactive destination |
| 1071 | * address is marked as active due to the reception of the latest |
| 1072 | * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also |
| 1073 | * clear the association overall error count as well (as defined |
| 1074 | * in section 8.1). |
| 1075 | * |
| 1076 | * The receiver of the HEARTBEAT ACK should also perform an RTT |
| 1077 | * measurement for that destination transport address using the time |
| 1078 | * value carried in the HEARTBEAT ACK chunk. |
| 1079 | * |
| 1080 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
| 1081 | * |
| 1082 | * Inputs |
| 1083 | * (endpoint, asoc, chunk) |
| 1084 | * |
| 1085 | * Outputs |
| 1086 | * (asoc, reply_msg, msg_up, timers, counters) |
| 1087 | * |
| 1088 | * The return value is the disposition of the chunk. |
| 1089 | */ |
| 1090 | sctp_disposition_t sctp_sf_backbeat_8_3(const struct sctp_endpoint *ep, |
| 1091 | const struct sctp_association *asoc, |
| 1092 | const sctp_subtype_t type, |
| 1093 | void *arg, |
| 1094 | sctp_cmd_seq_t *commands) |
| 1095 | { |
| 1096 | struct sctp_chunk *chunk = arg; |
| 1097 | union sctp_addr from_addr; |
| 1098 | struct sctp_transport *link; |
| 1099 | sctp_sender_hb_info_t *hbinfo; |
| 1100 | unsigned long max_interval; |
| 1101 | |
| 1102 | if (!sctp_vtag_verify(chunk, asoc)) |
| 1103 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 1104 | |
| 1105 | /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */ |
| 1106 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t))) |
| 1107 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 1108 | commands); |
| 1109 | |
| 1110 | hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data; |
| 1111 | /* Make sure that the length of the parameter is what we expect */ |
| 1112 | if (ntohs(hbinfo->param_hdr.length) != |
| 1113 | sizeof(sctp_sender_hb_info_t)) { |
| 1114 | return SCTP_DISPOSITION_DISCARD; |
| 1115 | } |
| 1116 | |
| 1117 | from_addr = hbinfo->daddr; |
| 1118 | link = sctp_assoc_lookup_paddr(asoc, &from_addr); |
| 1119 | |
| 1120 | /* This should never happen, but lets log it if so. */ |
| 1121 | if (unlikely(!link)) { |
| 1122 | if (from_addr.sa.sa_family == AF_INET6) { |
| 1123 | if (net_ratelimit()) |
| 1124 | printk(KERN_WARNING |
| 1125 | "%s association %p could not find address " |
| 1126 | NIP6_FMT "\n", |
| 1127 | __func__, |
| 1128 | asoc, |
| 1129 | NIP6(from_addr.v6.sin6_addr)); |
| 1130 | } else { |
| 1131 | if (net_ratelimit()) |
| 1132 | printk(KERN_WARNING |
| 1133 | "%s association %p could not find address " |
| 1134 | NIPQUAD_FMT "\n", |
| 1135 | __func__, |
| 1136 | asoc, |
| 1137 | NIPQUAD(from_addr.v4.sin_addr.s_addr)); |
| 1138 | } |
| 1139 | return SCTP_DISPOSITION_DISCARD; |
| 1140 | } |
| 1141 | |
| 1142 | /* Validate the 64-bit random nonce. */ |
| 1143 | if (hbinfo->hb_nonce != link->hb_nonce) |
| 1144 | return SCTP_DISPOSITION_DISCARD; |
| 1145 | |
| 1146 | max_interval = link->hbinterval + link->rto; |
| 1147 | |
| 1148 | /* Check if the timestamp looks valid. */ |
| 1149 | if (time_after(hbinfo->sent_at, jiffies) || |
| 1150 | time_after(jiffies, hbinfo->sent_at + max_interval)) { |
| 1151 | SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp " |
| 1152 | "received for transport: %p\n", |
| 1153 | __func__, link); |
| 1154 | return SCTP_DISPOSITION_DISCARD; |
| 1155 | } |
| 1156 | |
| 1157 | /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of |
| 1158 | * the HEARTBEAT should clear the error counter of the |
| 1159 | * destination transport address to which the HEARTBEAT was |
| 1160 | * sent and mark the destination transport address as active if |
| 1161 | * it is not so marked. |
| 1162 | */ |
| 1163 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link)); |
| 1164 | |
| 1165 | return SCTP_DISPOSITION_CONSUME; |
| 1166 | } |
| 1167 | |
| 1168 | /* Helper function to send out an abort for the restart |
| 1169 | * condition. |
| 1170 | */ |
| 1171 | static int sctp_sf_send_restart_abort(union sctp_addr *ssa, |
| 1172 | struct sctp_chunk *init, |
| 1173 | sctp_cmd_seq_t *commands) |
| 1174 | { |
| 1175 | int len; |
| 1176 | struct sctp_packet *pkt; |
| 1177 | union sctp_addr_param *addrparm; |
| 1178 | struct sctp_errhdr *errhdr; |
| 1179 | struct sctp_endpoint *ep; |
| 1180 | char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)]; |
| 1181 | struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family); |
| 1182 | |
| 1183 | /* Build the error on the stack. We are way to malloc crazy |
| 1184 | * throughout the code today. |
| 1185 | */ |
| 1186 | errhdr = (struct sctp_errhdr *)buffer; |
| 1187 | addrparm = (union sctp_addr_param *)errhdr->variable; |
| 1188 | |
| 1189 | /* Copy into a parm format. */ |
| 1190 | len = af->to_addr_param(ssa, addrparm); |
| 1191 | len += sizeof(sctp_errhdr_t); |
| 1192 | |
| 1193 | errhdr->cause = SCTP_ERROR_RESTART; |
| 1194 | errhdr->length = htons(len); |
| 1195 | |
| 1196 | /* Assign to the control socket. */ |
| 1197 | ep = sctp_sk((sctp_get_ctl_sock()))->ep; |
| 1198 | |
| 1199 | /* Association is NULL since this may be a restart attack and we |
| 1200 | * want to send back the attacker's vtag. |
| 1201 | */ |
| 1202 | pkt = sctp_abort_pkt_new(ep, NULL, init, errhdr, len); |
| 1203 | |
| 1204 | if (!pkt) |
| 1205 | goto out; |
| 1206 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt)); |
| 1207 | |
| 1208 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
| 1209 | |
| 1210 | /* Discard the rest of the inbound packet. */ |
| 1211 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL()); |
| 1212 | |
| 1213 | out: |
| 1214 | /* Even if there is no memory, treat as a failure so |
| 1215 | * the packet will get dropped. |
| 1216 | */ |
| 1217 | return 0; |
| 1218 | } |
| 1219 | |
| 1220 | /* A restart is occurring, check to make sure no new addresses |
| 1221 | * are being added as we may be under a takeover attack. |
| 1222 | */ |
| 1223 | static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc, |
| 1224 | const struct sctp_association *asoc, |
| 1225 | struct sctp_chunk *init, |
| 1226 | sctp_cmd_seq_t *commands) |
| 1227 | { |
| 1228 | struct sctp_transport *new_addr, *addr; |
| 1229 | struct list_head *pos, *pos2; |
| 1230 | int found; |
| 1231 | |
| 1232 | /* Implementor's Guide - Sectin 5.2.2 |
| 1233 | * ... |
| 1234 | * Before responding the endpoint MUST check to see if the |
| 1235 | * unexpected INIT adds new addresses to the association. If new |
| 1236 | * addresses are added to the association, the endpoint MUST respond |
| 1237 | * with an ABORT.. |
| 1238 | */ |
| 1239 | |
| 1240 | /* Search through all current addresses and make sure |
| 1241 | * we aren't adding any new ones. |
| 1242 | */ |
| 1243 | new_addr = NULL; |
| 1244 | found = 0; |
| 1245 | |
| 1246 | list_for_each(pos, &new_asoc->peer.transport_addr_list) { |
| 1247 | new_addr = list_entry(pos, struct sctp_transport, transports); |
| 1248 | found = 0; |
| 1249 | list_for_each(pos2, &asoc->peer.transport_addr_list) { |
| 1250 | addr = list_entry(pos2, struct sctp_transport, |
| 1251 | transports); |
| 1252 | if (sctp_cmp_addr_exact(&new_addr->ipaddr, |
| 1253 | &addr->ipaddr)) { |
| 1254 | found = 1; |
| 1255 | break; |
| 1256 | } |
| 1257 | } |
| 1258 | if (!found) |
| 1259 | break; |
| 1260 | } |
| 1261 | |
| 1262 | /* If a new address was added, ABORT the sender. */ |
| 1263 | if (!found && new_addr) { |
| 1264 | sctp_sf_send_restart_abort(&new_addr->ipaddr, init, commands); |
| 1265 | } |
| 1266 | |
| 1267 | /* Return success if all addresses were found. */ |
| 1268 | return found; |
| 1269 | } |
| 1270 | |
| 1271 | /* Populate the verification/tie tags based on overlapping INIT |
| 1272 | * scenario. |
| 1273 | * |
| 1274 | * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state. |
| 1275 | */ |
| 1276 | static void sctp_tietags_populate(struct sctp_association *new_asoc, |
| 1277 | const struct sctp_association *asoc) |
| 1278 | { |
| 1279 | switch (asoc->state) { |
| 1280 | |
| 1281 | /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */ |
| 1282 | |
| 1283 | case SCTP_STATE_COOKIE_WAIT: |
| 1284 | new_asoc->c.my_vtag = asoc->c.my_vtag; |
| 1285 | new_asoc->c.my_ttag = asoc->c.my_vtag; |
| 1286 | new_asoc->c.peer_ttag = 0; |
| 1287 | break; |
| 1288 | |
| 1289 | case SCTP_STATE_COOKIE_ECHOED: |
| 1290 | new_asoc->c.my_vtag = asoc->c.my_vtag; |
| 1291 | new_asoc->c.my_ttag = asoc->c.my_vtag; |
| 1292 | new_asoc->c.peer_ttag = asoc->c.peer_vtag; |
| 1293 | break; |
| 1294 | |
| 1295 | /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED, |
| 1296 | * COOKIE-WAIT and SHUTDOWN-ACK-SENT |
| 1297 | */ |
| 1298 | default: |
| 1299 | new_asoc->c.my_ttag = asoc->c.my_vtag; |
| 1300 | new_asoc->c.peer_ttag = asoc->c.peer_vtag; |
| 1301 | break; |
| 1302 | } |
| 1303 | |
| 1304 | /* Other parameters for the endpoint SHOULD be copied from the |
| 1305 | * existing parameters of the association (e.g. number of |
| 1306 | * outbound streams) into the INIT ACK and cookie. |
| 1307 | */ |
| 1308 | new_asoc->rwnd = asoc->rwnd; |
| 1309 | new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams; |
| 1310 | new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams; |
| 1311 | new_asoc->c.initial_tsn = asoc->c.initial_tsn; |
| 1312 | } |
| 1313 | |
| 1314 | /* |
| 1315 | * Compare vtag/tietag values to determine unexpected COOKIE-ECHO |
| 1316 | * handling action. |
| 1317 | * |
| 1318 | * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists. |
| 1319 | * |
| 1320 | * Returns value representing action to be taken. These action values |
| 1321 | * correspond to Action/Description values in RFC 2960, Table 2. |
| 1322 | */ |
| 1323 | static char sctp_tietags_compare(struct sctp_association *new_asoc, |
| 1324 | const struct sctp_association *asoc) |
| 1325 | { |
| 1326 | /* In this case, the peer may have restarted. */ |
| 1327 | if ((asoc->c.my_vtag != new_asoc->c.my_vtag) && |
| 1328 | (asoc->c.peer_vtag != new_asoc->c.peer_vtag) && |
| 1329 | (asoc->c.my_vtag == new_asoc->c.my_ttag) && |
| 1330 | (asoc->c.peer_vtag == new_asoc->c.peer_ttag)) |
| 1331 | return 'A'; |
| 1332 | |
| 1333 | /* Collision case B. */ |
| 1334 | if ((asoc->c.my_vtag == new_asoc->c.my_vtag) && |
| 1335 | ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) || |
| 1336 | (0 == asoc->c.peer_vtag))) { |
| 1337 | return 'B'; |
| 1338 | } |
| 1339 | |
| 1340 | /* Collision case D. */ |
| 1341 | if ((asoc->c.my_vtag == new_asoc->c.my_vtag) && |
| 1342 | (asoc->c.peer_vtag == new_asoc->c.peer_vtag)) |
| 1343 | return 'D'; |
| 1344 | |
| 1345 | /* Collision case C. */ |
| 1346 | if ((asoc->c.my_vtag != new_asoc->c.my_vtag) && |
| 1347 | (asoc->c.peer_vtag == new_asoc->c.peer_vtag) && |
| 1348 | (0 == new_asoc->c.my_ttag) && |
| 1349 | (0 == new_asoc->c.peer_ttag)) |
| 1350 | return 'C'; |
| 1351 | |
| 1352 | /* No match to any of the special cases; discard this packet. */ |
| 1353 | return 'E'; |
| 1354 | } |
| 1355 | |
| 1356 | /* Common helper routine for both duplicate and simulataneous INIT |
| 1357 | * chunk handling. |
| 1358 | */ |
| 1359 | static sctp_disposition_t sctp_sf_do_unexpected_init( |
| 1360 | const struct sctp_endpoint *ep, |
| 1361 | const struct sctp_association *asoc, |
| 1362 | const sctp_subtype_t type, |
| 1363 | void *arg, sctp_cmd_seq_t *commands) |
| 1364 | { |
| 1365 | sctp_disposition_t retval; |
| 1366 | struct sctp_chunk *chunk = arg; |
| 1367 | struct sctp_chunk *repl; |
| 1368 | struct sctp_association *new_asoc; |
| 1369 | struct sctp_chunk *err_chunk; |
| 1370 | struct sctp_packet *packet; |
| 1371 | sctp_unrecognized_param_t *unk_param; |
| 1372 | int len; |
| 1373 | |
| 1374 | /* 6.10 Bundling |
| 1375 | * An endpoint MUST NOT bundle INIT, INIT ACK or |
| 1376 | * SHUTDOWN COMPLETE with any other chunks. |
| 1377 | * |
| 1378 | * IG Section 2.11.2 |
| 1379 | * Furthermore, we require that the receiver of an INIT chunk MUST |
| 1380 | * enforce these rules by silently discarding an arriving packet |
| 1381 | * with an INIT chunk that is bundled with other chunks. |
| 1382 | */ |
| 1383 | if (!chunk->singleton) |
| 1384 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 1385 | |
| 1386 | /* 3.1 A packet containing an INIT chunk MUST have a zero Verification |
| 1387 | * Tag. |
| 1388 | */ |
| 1389 | if (chunk->sctp_hdr->vtag != 0) |
| 1390 | return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands); |
| 1391 | |
| 1392 | /* Make sure that the INIT chunk has a valid length. |
| 1393 | * In this case, we generate a protocol violation since we have |
| 1394 | * an association established. |
| 1395 | */ |
| 1396 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t))) |
| 1397 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 1398 | commands); |
| 1399 | /* Grab the INIT header. */ |
| 1400 | chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data; |
| 1401 | |
| 1402 | /* Tag the variable length parameters. */ |
| 1403 | chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t)); |
| 1404 | |
| 1405 | /* Verify the INIT chunk before processing it. */ |
| 1406 | err_chunk = NULL; |
| 1407 | if (!sctp_verify_init(asoc, chunk->chunk_hdr->type, |
| 1408 | (sctp_init_chunk_t *)chunk->chunk_hdr, chunk, |
| 1409 | &err_chunk)) { |
| 1410 | /* This chunk contains fatal error. It is to be discarded. |
| 1411 | * Send an ABORT, with causes if there is any. |
| 1412 | */ |
| 1413 | if (err_chunk) { |
| 1414 | packet = sctp_abort_pkt_new(ep, asoc, arg, |
| 1415 | (__u8 *)(err_chunk->chunk_hdr) + |
| 1416 | sizeof(sctp_chunkhdr_t), |
| 1417 | ntohs(err_chunk->chunk_hdr->length) - |
| 1418 | sizeof(sctp_chunkhdr_t)); |
| 1419 | |
| 1420 | if (packet) { |
| 1421 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
| 1422 | SCTP_PACKET(packet)); |
| 1423 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
| 1424 | retval = SCTP_DISPOSITION_CONSUME; |
| 1425 | } else { |
| 1426 | retval = SCTP_DISPOSITION_NOMEM; |
| 1427 | } |
| 1428 | goto cleanup; |
| 1429 | } else { |
| 1430 | return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, |
| 1431 | commands); |
| 1432 | } |
| 1433 | } |
| 1434 | |
| 1435 | /* |
| 1436 | * Other parameters for the endpoint SHOULD be copied from the |
| 1437 | * existing parameters of the association (e.g. number of |
| 1438 | * outbound streams) into the INIT ACK and cookie. |
| 1439 | * FIXME: We are copying parameters from the endpoint not the |
| 1440 | * association. |
| 1441 | */ |
| 1442 | new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC); |
| 1443 | if (!new_asoc) |
| 1444 | goto nomem; |
| 1445 | |
| 1446 | /* In the outbound INIT ACK the endpoint MUST copy its current |
| 1447 | * Verification Tag and Peers Verification tag into a reserved |
| 1448 | * place (local tie-tag and per tie-tag) within the state cookie. |
| 1449 | */ |
| 1450 | if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type, |
| 1451 | sctp_source(chunk), |
| 1452 | (sctp_init_chunk_t *)chunk->chunk_hdr, |
| 1453 | GFP_ATOMIC)) |
| 1454 | goto nomem; |
| 1455 | |
| 1456 | /* Make sure no new addresses are being added during the |
| 1457 | * restart. Do not do this check for COOKIE-WAIT state, |
| 1458 | * since there are no peer addresses to check against. |
| 1459 | * Upon return an ABORT will have been sent if needed. |
| 1460 | */ |
| 1461 | if (!sctp_state(asoc, COOKIE_WAIT)) { |
| 1462 | if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, |
| 1463 | commands)) { |
| 1464 | retval = SCTP_DISPOSITION_CONSUME; |
| 1465 | goto nomem_retval; |
| 1466 | } |
| 1467 | } |
| 1468 | |
| 1469 | sctp_tietags_populate(new_asoc, asoc); |
| 1470 | |
| 1471 | /* B) "Z" shall respond immediately with an INIT ACK chunk. */ |
| 1472 | |
| 1473 | /* If there are errors need to be reported for unknown parameters, |
| 1474 | * make sure to reserve enough room in the INIT ACK for them. |
| 1475 | */ |
| 1476 | len = 0; |
| 1477 | if (err_chunk) { |
| 1478 | len = ntohs(err_chunk->chunk_hdr->length) - |
| 1479 | sizeof(sctp_chunkhdr_t); |
| 1480 | } |
| 1481 | |
| 1482 | if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0) |
| 1483 | goto nomem; |
| 1484 | |
| 1485 | repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len); |
| 1486 | if (!repl) |
| 1487 | goto nomem; |
| 1488 | |
| 1489 | /* If there are errors need to be reported for unknown parameters, |
| 1490 | * include them in the outgoing INIT ACK as "Unrecognized parameter" |
| 1491 | * parameter. |
| 1492 | */ |
| 1493 | if (err_chunk) { |
| 1494 | /* Get the "Unrecognized parameter" parameter(s) out of the |
| 1495 | * ERROR chunk generated by sctp_verify_init(). Since the |
| 1496 | * error cause code for "unknown parameter" and the |
| 1497 | * "Unrecognized parameter" type is the same, we can |
| 1498 | * construct the parameters in INIT ACK by copying the |
| 1499 | * ERROR causes over. |
| 1500 | */ |
| 1501 | unk_param = (sctp_unrecognized_param_t *) |
| 1502 | ((__u8 *)(err_chunk->chunk_hdr) + |
| 1503 | sizeof(sctp_chunkhdr_t)); |
| 1504 | /* Replace the cause code with the "Unrecognized parameter" |
| 1505 | * parameter type. |
| 1506 | */ |
| 1507 | sctp_addto_chunk(repl, len, unk_param); |
| 1508 | } |
| 1509 | |
| 1510 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc)); |
| 1511 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
| 1512 | |
| 1513 | /* |
| 1514 | * Note: After sending out INIT ACK with the State Cookie parameter, |
| 1515 | * "Z" MUST NOT allocate any resources for this new association. |
| 1516 | * Otherwise, "Z" will be vulnerable to resource attacks. |
| 1517 | */ |
| 1518 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
| 1519 | retval = SCTP_DISPOSITION_CONSUME; |
| 1520 | |
| 1521 | return retval; |
| 1522 | |
| 1523 | nomem: |
| 1524 | retval = SCTP_DISPOSITION_NOMEM; |
| 1525 | nomem_retval: |
| 1526 | if (new_asoc) |
| 1527 | sctp_association_free(new_asoc); |
| 1528 | cleanup: |
| 1529 | if (err_chunk) |
| 1530 | sctp_chunk_free(err_chunk); |
| 1531 | return retval; |
| 1532 | } |
| 1533 | |
| 1534 | /* |
| 1535 | * Handle simultanous INIT. |
| 1536 | * This means we started an INIT and then we got an INIT request from |
| 1537 | * our peer. |
| 1538 | * |
| 1539 | * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B) |
| 1540 | * This usually indicates an initialization collision, i.e., each |
| 1541 | * endpoint is attempting, at about the same time, to establish an |
| 1542 | * association with the other endpoint. |
| 1543 | * |
| 1544 | * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an |
| 1545 | * endpoint MUST respond with an INIT ACK using the same parameters it |
| 1546 | * sent in its original INIT chunk (including its Verification Tag, |
| 1547 | * unchanged). These original parameters are combined with those from the |
| 1548 | * newly received INIT chunk. The endpoint shall also generate a State |
| 1549 | * Cookie with the INIT ACK. The endpoint uses the parameters sent in its |
| 1550 | * INIT to calculate the State Cookie. |
| 1551 | * |
| 1552 | * After that, the endpoint MUST NOT change its state, the T1-init |
| 1553 | * timer shall be left running and the corresponding TCB MUST NOT be |
| 1554 | * destroyed. The normal procedures for handling State Cookies when |
| 1555 | * a TCB exists will resolve the duplicate INITs to a single association. |
| 1556 | * |
| 1557 | * For an endpoint that is in the COOKIE-ECHOED state it MUST populate |
| 1558 | * its Tie-Tags with the Tag information of itself and its peer (see |
| 1559 | * section 5.2.2 for a description of the Tie-Tags). |
| 1560 | * |
| 1561 | * Verification Tag: Not explicit, but an INIT can not have a valid |
| 1562 | * verification tag, so we skip the check. |
| 1563 | * |
| 1564 | * Inputs |
| 1565 | * (endpoint, asoc, chunk) |
| 1566 | * |
| 1567 | * Outputs |
| 1568 | * (asoc, reply_msg, msg_up, timers, counters) |
| 1569 | * |
| 1570 | * The return value is the disposition of the chunk. |
| 1571 | */ |
| 1572 | sctp_disposition_t sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint *ep, |
| 1573 | const struct sctp_association *asoc, |
| 1574 | const sctp_subtype_t type, |
| 1575 | void *arg, |
| 1576 | sctp_cmd_seq_t *commands) |
| 1577 | { |
| 1578 | /* Call helper to do the real work for both simulataneous and |
| 1579 | * duplicate INIT chunk handling. |
| 1580 | */ |
| 1581 | return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands); |
| 1582 | } |
| 1583 | |
| 1584 | /* |
| 1585 | * Handle duplicated INIT messages. These are usually delayed |
| 1586 | * restransmissions. |
| 1587 | * |
| 1588 | * Section: 5.2.2 Unexpected INIT in States Other than CLOSED, |
| 1589 | * COOKIE-ECHOED and COOKIE-WAIT |
| 1590 | * |
| 1591 | * Unless otherwise stated, upon reception of an unexpected INIT for |
| 1592 | * this association, the endpoint shall generate an INIT ACK with a |
| 1593 | * State Cookie. In the outbound INIT ACK the endpoint MUST copy its |
| 1594 | * current Verification Tag and peer's Verification Tag into a reserved |
| 1595 | * place within the state cookie. We shall refer to these locations as |
| 1596 | * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet |
| 1597 | * containing this INIT ACK MUST carry a Verification Tag value equal to |
| 1598 | * the Initiation Tag found in the unexpected INIT. And the INIT ACK |
| 1599 | * MUST contain a new Initiation Tag (randomly generated see Section |
| 1600 | * 5.3.1). Other parameters for the endpoint SHOULD be copied from the |
| 1601 | * existing parameters of the association (e.g. number of outbound |
| 1602 | * streams) into the INIT ACK and cookie. |
| 1603 | * |
| 1604 | * After sending out the INIT ACK, the endpoint shall take no further |
| 1605 | * actions, i.e., the existing association, including its current state, |
| 1606 | * and the corresponding TCB MUST NOT be changed. |
| 1607 | * |
| 1608 | * Note: Only when a TCB exists and the association is not in a COOKIE- |
| 1609 | * WAIT state are the Tie-Tags populated. For a normal association INIT |
| 1610 | * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be |
| 1611 | * set to 0 (indicating that no previous TCB existed). The INIT ACK and |
| 1612 | * State Cookie are populated as specified in section 5.2.1. |
| 1613 | * |
| 1614 | * Verification Tag: Not specified, but an INIT has no way of knowing |
| 1615 | * what the verification tag could be, so we ignore it. |
| 1616 | * |
| 1617 | * Inputs |
| 1618 | * (endpoint, asoc, chunk) |
| 1619 | * |
| 1620 | * Outputs |
| 1621 | * (asoc, reply_msg, msg_up, timers, counters) |
| 1622 | * |
| 1623 | * The return value is the disposition of the chunk. |
| 1624 | */ |
| 1625 | sctp_disposition_t sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint *ep, |
| 1626 | const struct sctp_association *asoc, |
| 1627 | const sctp_subtype_t type, |
| 1628 | void *arg, |
| 1629 | sctp_cmd_seq_t *commands) |
| 1630 | { |
| 1631 | /* Call helper to do the real work for both simulataneous and |
| 1632 | * duplicate INIT chunk handling. |
| 1633 | */ |
| 1634 | return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands); |
| 1635 | } |
| 1636 | |
| 1637 | |
| 1638 | /* |
| 1639 | * Unexpected INIT-ACK handler. |
| 1640 | * |
| 1641 | * Section 5.2.3 |
| 1642 | * If an INIT ACK received by an endpoint in any state other than the |
| 1643 | * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk. |
| 1644 | * An unexpected INIT ACK usually indicates the processing of an old or |
| 1645 | * duplicated INIT chunk. |
| 1646 | */ |
| 1647 | sctp_disposition_t sctp_sf_do_5_2_3_initack(const struct sctp_endpoint *ep, |
| 1648 | const struct sctp_association *asoc, |
| 1649 | const sctp_subtype_t type, |
| 1650 | void *arg, sctp_cmd_seq_t *commands) |
| 1651 | { |
| 1652 | /* Per the above section, we'll discard the chunk if we have an |
| 1653 | * endpoint. If this is an OOTB INIT-ACK, treat it as such. |
| 1654 | */ |
| 1655 | if (ep == sctp_sk((sctp_get_ctl_sock()))->ep) |
| 1656 | return sctp_sf_ootb(ep, asoc, type, arg, commands); |
| 1657 | else |
| 1658 | return sctp_sf_discard_chunk(ep, asoc, type, arg, commands); |
| 1659 | } |
| 1660 | |
| 1661 | /* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A') |
| 1662 | * |
| 1663 | * Section 5.2.4 |
| 1664 | * A) In this case, the peer may have restarted. |
| 1665 | */ |
| 1666 | static sctp_disposition_t sctp_sf_do_dupcook_a(const struct sctp_endpoint *ep, |
| 1667 | const struct sctp_association *asoc, |
| 1668 | struct sctp_chunk *chunk, |
| 1669 | sctp_cmd_seq_t *commands, |
| 1670 | struct sctp_association *new_asoc) |
| 1671 | { |
| 1672 | sctp_init_chunk_t *peer_init; |
| 1673 | struct sctp_ulpevent *ev; |
| 1674 | struct sctp_chunk *repl; |
| 1675 | struct sctp_chunk *err; |
| 1676 | sctp_disposition_t disposition; |
| 1677 | |
| 1678 | /* new_asoc is a brand-new association, so these are not yet |
| 1679 | * side effects--it is safe to run them here. |
| 1680 | */ |
| 1681 | peer_init = &chunk->subh.cookie_hdr->c.peer_init[0]; |
| 1682 | |
| 1683 | if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type, |
| 1684 | sctp_source(chunk), peer_init, |
| 1685 | GFP_ATOMIC)) |
| 1686 | goto nomem; |
| 1687 | |
| 1688 | /* Make sure no new addresses are being added during the |
| 1689 | * restart. Though this is a pretty complicated attack |
| 1690 | * since you'd have to get inside the cookie. |
| 1691 | */ |
| 1692 | if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) { |
| 1693 | return SCTP_DISPOSITION_CONSUME; |
| 1694 | } |
| 1695 | |
| 1696 | /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes |
| 1697 | * the peer has restarted (Action A), it MUST NOT setup a new |
| 1698 | * association but instead resend the SHUTDOWN ACK and send an ERROR |
| 1699 | * chunk with a "Cookie Received while Shutting Down" error cause to |
| 1700 | * its peer. |
| 1701 | */ |
| 1702 | if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) { |
| 1703 | disposition = sctp_sf_do_9_2_reshutack(ep, asoc, |
| 1704 | SCTP_ST_CHUNK(chunk->chunk_hdr->type), |
| 1705 | chunk, commands); |
| 1706 | if (SCTP_DISPOSITION_NOMEM == disposition) |
| 1707 | goto nomem; |
| 1708 | |
| 1709 | err = sctp_make_op_error(asoc, chunk, |
| 1710 | SCTP_ERROR_COOKIE_IN_SHUTDOWN, |
| 1711 | NULL, 0); |
| 1712 | if (err) |
| 1713 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
| 1714 | SCTP_CHUNK(err)); |
| 1715 | |
| 1716 | return SCTP_DISPOSITION_CONSUME; |
| 1717 | } |
| 1718 | |
| 1719 | /* For now, fail any unsent/unacked data. Consider the optional |
| 1720 | * choice of resending of this data. |
| 1721 | */ |
| 1722 | sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL()); |
| 1723 | |
| 1724 | repl = sctp_make_cookie_ack(new_asoc, chunk); |
| 1725 | if (!repl) |
| 1726 | goto nomem; |
| 1727 | |
| 1728 | /* Report association restart to upper layer. */ |
| 1729 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0, |
| 1730 | new_asoc->c.sinit_num_ostreams, |
| 1731 | new_asoc->c.sinit_max_instreams, |
| 1732 | NULL, GFP_ATOMIC); |
| 1733 | if (!ev) |
| 1734 | goto nomem_ev; |
| 1735 | |
| 1736 | /* Update the content of current association. */ |
| 1737 | sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc)); |
| 1738 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
| 1739 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); |
| 1740 | return SCTP_DISPOSITION_CONSUME; |
| 1741 | |
| 1742 | nomem_ev: |
| 1743 | sctp_chunk_free(repl); |
| 1744 | nomem: |
| 1745 | return SCTP_DISPOSITION_NOMEM; |
| 1746 | } |
| 1747 | |
| 1748 | /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B') |
| 1749 | * |
| 1750 | * Section 5.2.4 |
| 1751 | * B) In this case, both sides may be attempting to start an association |
| 1752 | * at about the same time but the peer endpoint started its INIT |
| 1753 | * after responding to the local endpoint's INIT |
| 1754 | */ |
| 1755 | /* This case represents an initialization collision. */ |
| 1756 | static sctp_disposition_t sctp_sf_do_dupcook_b(const struct sctp_endpoint *ep, |
| 1757 | const struct sctp_association *asoc, |
| 1758 | struct sctp_chunk *chunk, |
| 1759 | sctp_cmd_seq_t *commands, |
| 1760 | struct sctp_association *new_asoc) |
| 1761 | { |
| 1762 | sctp_init_chunk_t *peer_init; |
| 1763 | struct sctp_chunk *repl; |
| 1764 | |
| 1765 | /* new_asoc is a brand-new association, so these are not yet |
| 1766 | * side effects--it is safe to run them here. |
| 1767 | */ |
| 1768 | peer_init = &chunk->subh.cookie_hdr->c.peer_init[0]; |
| 1769 | if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type, |
| 1770 | sctp_source(chunk), peer_init, |
| 1771 | GFP_ATOMIC)) |
| 1772 | goto nomem; |
| 1773 | |
| 1774 | /* Update the content of current association. */ |
| 1775 | sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc)); |
| 1776 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| 1777 | SCTP_STATE(SCTP_STATE_ESTABLISHED)); |
| 1778 | SCTP_INC_STATS(SCTP_MIB_CURRESTAB); |
| 1779 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL()); |
| 1780 | |
| 1781 | repl = sctp_make_cookie_ack(new_asoc, chunk); |
| 1782 | if (!repl) |
| 1783 | goto nomem; |
| 1784 | |
| 1785 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
| 1786 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL()); |
| 1787 | |
| 1788 | /* RFC 2960 5.1 Normal Establishment of an Association |
| 1789 | * |
| 1790 | * D) IMPLEMENTATION NOTE: An implementation may choose to |
| 1791 | * send the Communication Up notification to the SCTP user |
| 1792 | * upon reception of a valid COOKIE ECHO chunk. |
| 1793 | * |
| 1794 | * Sadly, this needs to be implemented as a side-effect, because |
| 1795 | * we are not guaranteed to have set the association id of the real |
| 1796 | * association and so these notifications need to be delayed until |
| 1797 | * the association id is allocated. |
| 1798 | */ |
| 1799 | |
| 1800 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP)); |
| 1801 | |
| 1802 | /* Sockets API Draft Section 5.3.1.6 |
| 1803 | * When a peer sends a Adaptation Layer Indication parameter , SCTP |
| 1804 | * delivers this notification to inform the application that of the |
| 1805 | * peers requested adaptation layer. |
| 1806 | * |
| 1807 | * This also needs to be done as a side effect for the same reason as |
| 1808 | * above. |
| 1809 | */ |
| 1810 | if (asoc->peer.adaptation_ind) |
| 1811 | sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL()); |
| 1812 | |
| 1813 | return SCTP_DISPOSITION_CONSUME; |
| 1814 | |
| 1815 | nomem: |
| 1816 | return SCTP_DISPOSITION_NOMEM; |
| 1817 | } |
| 1818 | |
| 1819 | /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C') |
| 1820 | * |
| 1821 | * Section 5.2.4 |
| 1822 | * C) In this case, the local endpoint's cookie has arrived late. |
| 1823 | * Before it arrived, the local endpoint sent an INIT and received an |
| 1824 | * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag |
| 1825 | * but a new tag of its own. |
| 1826 | */ |
| 1827 | /* This case represents an initialization collision. */ |
| 1828 | static sctp_disposition_t sctp_sf_do_dupcook_c(const struct sctp_endpoint *ep, |
| 1829 | const struct sctp_association *asoc, |
| 1830 | struct sctp_chunk *chunk, |
| 1831 | sctp_cmd_seq_t *commands, |
| 1832 | struct sctp_association *new_asoc) |
| 1833 | { |
| 1834 | /* The cookie should be silently discarded. |
| 1835 | * The endpoint SHOULD NOT change states and should leave |
| 1836 | * any timers running. |
| 1837 | */ |
| 1838 | return SCTP_DISPOSITION_DISCARD; |
| 1839 | } |
| 1840 | |
| 1841 | /* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D') |
| 1842 | * |
| 1843 | * Section 5.2.4 |
| 1844 | * |
| 1845 | * D) When both local and remote tags match the endpoint should always |
| 1846 | * enter the ESTABLISHED state, if it has not already done so. |
| 1847 | */ |
| 1848 | /* This case represents an initialization collision. */ |
| 1849 | static sctp_disposition_t sctp_sf_do_dupcook_d(const struct sctp_endpoint *ep, |
| 1850 | const struct sctp_association *asoc, |
| 1851 | struct sctp_chunk *chunk, |
| 1852 | sctp_cmd_seq_t *commands, |
| 1853 | struct sctp_association *new_asoc) |
| 1854 | { |
| 1855 | struct sctp_ulpevent *ev = NULL, *ai_ev = NULL; |
| 1856 | struct sctp_chunk *repl; |
| 1857 | |
| 1858 | /* Clarification from Implementor's Guide: |
| 1859 | * D) When both local and remote tags match the endpoint should |
| 1860 | * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state. |
| 1861 | * It should stop any cookie timer that may be running and send |
| 1862 | * a COOKIE ACK. |
| 1863 | */ |
| 1864 | |
| 1865 | /* Don't accidentally move back into established state. */ |
| 1866 | if (asoc->state < SCTP_STATE_ESTABLISHED) { |
| 1867 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| 1868 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); |
| 1869 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| 1870 | SCTP_STATE(SCTP_STATE_ESTABLISHED)); |
| 1871 | SCTP_INC_STATS(SCTP_MIB_CURRESTAB); |
| 1872 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, |
| 1873 | SCTP_NULL()); |
| 1874 | |
| 1875 | /* RFC 2960 5.1 Normal Establishment of an Association |
| 1876 | * |
| 1877 | * D) IMPLEMENTATION NOTE: An implementation may choose |
| 1878 | * to send the Communication Up notification to the |
| 1879 | * SCTP user upon reception of a valid COOKIE |
| 1880 | * ECHO chunk. |
| 1881 | */ |
| 1882 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, |
| 1883 | SCTP_COMM_UP, 0, |
| 1884 | asoc->c.sinit_num_ostreams, |
| 1885 | asoc->c.sinit_max_instreams, |
| 1886 | NULL, GFP_ATOMIC); |
| 1887 | if (!ev) |
| 1888 | goto nomem; |
| 1889 | |
| 1890 | /* Sockets API Draft Section 5.3.1.6 |
| 1891 | * When a peer sends a Adaptation Layer Indication parameter, |
| 1892 | * SCTP delivers this notification to inform the application |
| 1893 | * that of the peers requested adaptation layer. |
| 1894 | */ |
| 1895 | if (asoc->peer.adaptation_ind) { |
| 1896 | ai_ev = sctp_ulpevent_make_adaptation_indication(asoc, |
| 1897 | GFP_ATOMIC); |
| 1898 | if (!ai_ev) |
| 1899 | goto nomem; |
| 1900 | |
| 1901 | } |
| 1902 | } |
| 1903 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL()); |
| 1904 | |
| 1905 | repl = sctp_make_cookie_ack(new_asoc, chunk); |
| 1906 | if (!repl) |
| 1907 | goto nomem; |
| 1908 | |
| 1909 | if (ev) |
| 1910 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
| 1911 | SCTP_ULPEVENT(ev)); |
| 1912 | if (ai_ev) |
| 1913 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
| 1914 | SCTP_ULPEVENT(ai_ev)); |
| 1915 | |
| 1916 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
| 1917 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL()); |
| 1918 | |
| 1919 | return SCTP_DISPOSITION_CONSUME; |
| 1920 | |
| 1921 | nomem: |
| 1922 | if (ai_ev) |
| 1923 | sctp_ulpevent_free(ai_ev); |
| 1924 | if (ev) |
| 1925 | sctp_ulpevent_free(ev); |
| 1926 | return SCTP_DISPOSITION_NOMEM; |
| 1927 | } |
| 1928 | |
| 1929 | /* |
| 1930 | * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying |
| 1931 | * chunk was retransmitted and then delayed in the network. |
| 1932 | * |
| 1933 | * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists |
| 1934 | * |
| 1935 | * Verification Tag: None. Do cookie validation. |
| 1936 | * |
| 1937 | * Inputs |
| 1938 | * (endpoint, asoc, chunk) |
| 1939 | * |
| 1940 | * Outputs |
| 1941 | * (asoc, reply_msg, msg_up, timers, counters) |
| 1942 | * |
| 1943 | * The return value is the disposition of the chunk. |
| 1944 | */ |
| 1945 | sctp_disposition_t sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint *ep, |
| 1946 | const struct sctp_association *asoc, |
| 1947 | const sctp_subtype_t type, |
| 1948 | void *arg, |
| 1949 | sctp_cmd_seq_t *commands) |
| 1950 | { |
| 1951 | sctp_disposition_t retval; |
| 1952 | struct sctp_chunk *chunk = arg; |
| 1953 | struct sctp_association *new_asoc; |
| 1954 | int error = 0; |
| 1955 | char action; |
| 1956 | struct sctp_chunk *err_chk_p; |
| 1957 | |
| 1958 | /* Make sure that the chunk has a valid length from the protocol |
| 1959 | * perspective. In this case check to make sure we have at least |
| 1960 | * enough for the chunk header. Cookie length verification is |
| 1961 | * done later. |
| 1962 | */ |
| 1963 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
| 1964 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 1965 | commands); |
| 1966 | |
| 1967 | /* "Decode" the chunk. We have no optional parameters so we |
| 1968 | * are in good shape. |
| 1969 | */ |
| 1970 | chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data; |
| 1971 | if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) - |
| 1972 | sizeof(sctp_chunkhdr_t))) |
| 1973 | goto nomem; |
| 1974 | |
| 1975 | /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie |
| 1976 | * of a duplicate COOKIE ECHO match the Verification Tags of the |
| 1977 | * current association, consider the State Cookie valid even if |
| 1978 | * the lifespan is exceeded. |
| 1979 | */ |
| 1980 | new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error, |
| 1981 | &err_chk_p); |
| 1982 | |
| 1983 | /* FIXME: |
| 1984 | * If the re-build failed, what is the proper error path |
| 1985 | * from here? |
| 1986 | * |
| 1987 | * [We should abort the association. --piggy] |
| 1988 | */ |
| 1989 | if (!new_asoc) { |
| 1990 | /* FIXME: Several errors are possible. A bad cookie should |
| 1991 | * be silently discarded, but think about logging it too. |
| 1992 | */ |
| 1993 | switch (error) { |
| 1994 | case -SCTP_IERROR_NOMEM: |
| 1995 | goto nomem; |
| 1996 | |
| 1997 | case -SCTP_IERROR_STALE_COOKIE: |
| 1998 | sctp_send_stale_cookie_err(ep, asoc, chunk, commands, |
| 1999 | err_chk_p); |
| 2000 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 2001 | case -SCTP_IERROR_BAD_SIG: |
| 2002 | default: |
| 2003 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 2004 | } |
| 2005 | } |
| 2006 | |
| 2007 | /* Compare the tie_tag in cookie with the verification tag of |
| 2008 | * current association. |
| 2009 | */ |
| 2010 | action = sctp_tietags_compare(new_asoc, asoc); |
| 2011 | |
| 2012 | switch (action) { |
| 2013 | case 'A': /* Association restart. */ |
| 2014 | retval = sctp_sf_do_dupcook_a(ep, asoc, chunk, commands, |
| 2015 | new_asoc); |
| 2016 | break; |
| 2017 | |
| 2018 | case 'B': /* Collision case B. */ |
| 2019 | retval = sctp_sf_do_dupcook_b(ep, asoc, chunk, commands, |
| 2020 | new_asoc); |
| 2021 | break; |
| 2022 | |
| 2023 | case 'C': /* Collision case C. */ |
| 2024 | retval = sctp_sf_do_dupcook_c(ep, asoc, chunk, commands, |
| 2025 | new_asoc); |
| 2026 | break; |
| 2027 | |
| 2028 | case 'D': /* Collision case D. */ |
| 2029 | retval = sctp_sf_do_dupcook_d(ep, asoc, chunk, commands, |
| 2030 | new_asoc); |
| 2031 | break; |
| 2032 | |
| 2033 | default: /* Discard packet for all others. */ |
| 2034 | retval = sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 2035 | break; |
| 2036 | } |
| 2037 | |
| 2038 | /* Delete the tempory new association. */ |
| 2039 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc)); |
| 2040 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
| 2041 | |
| 2042 | return retval; |
| 2043 | |
| 2044 | nomem: |
| 2045 | return SCTP_DISPOSITION_NOMEM; |
| 2046 | } |
| 2047 | |
| 2048 | /* |
| 2049 | * Process an ABORT. (SHUTDOWN-PENDING state) |
| 2050 | * |
| 2051 | * See sctp_sf_do_9_1_abort(). |
| 2052 | */ |
| 2053 | sctp_disposition_t sctp_sf_shutdown_pending_abort( |
| 2054 | const struct sctp_endpoint *ep, |
| 2055 | const struct sctp_association *asoc, |
| 2056 | const sctp_subtype_t type, |
| 2057 | void *arg, |
| 2058 | sctp_cmd_seq_t *commands) |
| 2059 | { |
| 2060 | struct sctp_chunk *chunk = arg; |
| 2061 | |
| 2062 | if (!sctp_vtag_verify_either(chunk, asoc)) |
| 2063 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 2064 | |
| 2065 | /* Make sure that the ABORT chunk has a valid length. |
| 2066 | * Since this is an ABORT chunk, we have to discard it |
| 2067 | * because of the following text: |
| 2068 | * RFC 2960, Section 3.3.7 |
| 2069 | * If an endpoint receives an ABORT with a format error or for an |
| 2070 | * association that doesn't exist, it MUST silently discard it. |
| 2071 | * Becasue the length is "invalid", we can't really discard just |
| 2072 | * as we do not know its true length. So, to be safe, discard the |
| 2073 | * packet. |
| 2074 | */ |
| 2075 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t))) |
| 2076 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 2077 | |
| 2078 | /* ADD-IP: Special case for ABORT chunks |
| 2079 | * F4) One special consideration is that ABORT Chunks arriving |
| 2080 | * destined to the IP address being deleted MUST be |
| 2081 | * ignored (see Section 5.3.1 for further details). |
| 2082 | */ |
| 2083 | if (SCTP_ADDR_DEL == |
| 2084 | sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest)) |
| 2085 | return sctp_sf_discard_chunk(ep, asoc, type, arg, commands); |
| 2086 | |
| 2087 | /* Stop the T5-shutdown guard timer. */ |
| 2088 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| 2089 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
| 2090 | |
| 2091 | return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands); |
| 2092 | } |
| 2093 | |
| 2094 | /* |
| 2095 | * Process an ABORT. (SHUTDOWN-SENT state) |
| 2096 | * |
| 2097 | * See sctp_sf_do_9_1_abort(). |
| 2098 | */ |
| 2099 | sctp_disposition_t sctp_sf_shutdown_sent_abort(const struct sctp_endpoint *ep, |
| 2100 | const struct sctp_association *asoc, |
| 2101 | const sctp_subtype_t type, |
| 2102 | void *arg, |
| 2103 | sctp_cmd_seq_t *commands) |
| 2104 | { |
| 2105 | struct sctp_chunk *chunk = arg; |
| 2106 | |
| 2107 | if (!sctp_vtag_verify_either(chunk, asoc)) |
| 2108 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 2109 | |
| 2110 | /* Make sure that the ABORT chunk has a valid length. |
| 2111 | * Since this is an ABORT chunk, we have to discard it |
| 2112 | * because of the following text: |
| 2113 | * RFC 2960, Section 3.3.7 |
| 2114 | * If an endpoint receives an ABORT with a format error or for an |
| 2115 | * association that doesn't exist, it MUST silently discard it. |
| 2116 | * Becasue the length is "invalid", we can't really discard just |
| 2117 | * as we do not know its true length. So, to be safe, discard the |
| 2118 | * packet. |
| 2119 | */ |
| 2120 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t))) |
| 2121 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 2122 | |
| 2123 | /* ADD-IP: Special case for ABORT chunks |
| 2124 | * F4) One special consideration is that ABORT Chunks arriving |
| 2125 | * destined to the IP address being deleted MUST be |
| 2126 | * ignored (see Section 5.3.1 for further details). |
| 2127 | */ |
| 2128 | if (SCTP_ADDR_DEL == |
| 2129 | sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest)) |
| 2130 | return sctp_sf_discard_chunk(ep, asoc, type, arg, commands); |
| 2131 | |
| 2132 | /* Stop the T2-shutdown timer. */ |
| 2133 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| 2134 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
| 2135 | |
| 2136 | /* Stop the T5-shutdown guard timer. */ |
| 2137 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| 2138 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
| 2139 | |
| 2140 | return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands); |
| 2141 | } |
| 2142 | |
| 2143 | /* |
| 2144 | * Process an ABORT. (SHUTDOWN-ACK-SENT state) |
| 2145 | * |
| 2146 | * See sctp_sf_do_9_1_abort(). |
| 2147 | */ |
| 2148 | sctp_disposition_t sctp_sf_shutdown_ack_sent_abort( |
| 2149 | const struct sctp_endpoint *ep, |
| 2150 | const struct sctp_association *asoc, |
| 2151 | const sctp_subtype_t type, |
| 2152 | void *arg, |
| 2153 | sctp_cmd_seq_t *commands) |
| 2154 | { |
| 2155 | /* The same T2 timer, so we should be able to use |
| 2156 | * common function with the SHUTDOWN-SENT state. |
| 2157 | */ |
| 2158 | return sctp_sf_shutdown_sent_abort(ep, asoc, type, arg, commands); |
| 2159 | } |
| 2160 | |
| 2161 | /* |
| 2162 | * Handle an Error received in COOKIE_ECHOED state. |
| 2163 | * |
| 2164 | * Only handle the error type of stale COOKIE Error, the other errors will |
| 2165 | * be ignored. |
| 2166 | * |
| 2167 | * Inputs |
| 2168 | * (endpoint, asoc, chunk) |
| 2169 | * |
| 2170 | * Outputs |
| 2171 | * (asoc, reply_msg, msg_up, timers, counters) |
| 2172 | * |
| 2173 | * The return value is the disposition of the chunk. |
| 2174 | */ |
| 2175 | sctp_disposition_t sctp_sf_cookie_echoed_err(const struct sctp_endpoint *ep, |
| 2176 | const struct sctp_association *asoc, |
| 2177 | const sctp_subtype_t type, |
| 2178 | void *arg, |
| 2179 | sctp_cmd_seq_t *commands) |
| 2180 | { |
| 2181 | struct sctp_chunk *chunk = arg; |
| 2182 | sctp_errhdr_t *err; |
| 2183 | |
| 2184 | if (!sctp_vtag_verify(chunk, asoc)) |
| 2185 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 2186 | |
| 2187 | /* Make sure that the ERROR chunk has a valid length. |
| 2188 | * The parameter walking depends on this as well. |
| 2189 | */ |
| 2190 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t))) |
| 2191 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 2192 | commands); |
| 2193 | |
| 2194 | /* Process the error here */ |
| 2195 | /* FUTURE FIXME: When PR-SCTP related and other optional |
| 2196 | * parms are emitted, this will have to change to handle multiple |
| 2197 | * errors. |
| 2198 | */ |
| 2199 | sctp_walk_errors(err, chunk->chunk_hdr) { |
| 2200 | if (SCTP_ERROR_STALE_COOKIE == err->cause) |
| 2201 | return sctp_sf_do_5_2_6_stale(ep, asoc, type, |
| 2202 | arg, commands); |
| 2203 | } |
| 2204 | |
| 2205 | /* It is possible to have malformed error causes, and that |
| 2206 | * will cause us to end the walk early. However, since |
| 2207 | * we are discarding the packet, there should be no adverse |
| 2208 | * affects. |
| 2209 | */ |
| 2210 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 2211 | } |
| 2212 | |
| 2213 | /* |
| 2214 | * Handle a Stale COOKIE Error |
| 2215 | * |
| 2216 | * Section: 5.2.6 Handle Stale COOKIE Error |
| 2217 | * If the association is in the COOKIE-ECHOED state, the endpoint may elect |
| 2218 | * one of the following three alternatives. |
| 2219 | * ... |
| 2220 | * 3) Send a new INIT chunk to the endpoint, adding a Cookie |
| 2221 | * Preservative parameter requesting an extension to the lifetime of |
| 2222 | * the State Cookie. When calculating the time extension, an |
| 2223 | * implementation SHOULD use the RTT information measured based on the |
| 2224 | * previous COOKIE ECHO / ERROR exchange, and should add no more |
| 2225 | * than 1 second beyond the measured RTT, due to long State Cookie |
| 2226 | * lifetimes making the endpoint more subject to a replay attack. |
| 2227 | * |
| 2228 | * Verification Tag: Not explicit, but safe to ignore. |
| 2229 | * |
| 2230 | * Inputs |
| 2231 | * (endpoint, asoc, chunk) |
| 2232 | * |
| 2233 | * Outputs |
| 2234 | * (asoc, reply_msg, msg_up, timers, counters) |
| 2235 | * |
| 2236 | * The return value is the disposition of the chunk. |
| 2237 | */ |
| 2238 | static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep, |
| 2239 | const struct sctp_association *asoc, |
| 2240 | const sctp_subtype_t type, |
| 2241 | void *arg, |
| 2242 | sctp_cmd_seq_t *commands) |
| 2243 | { |
| 2244 | struct sctp_chunk *chunk = arg; |
| 2245 | time_t stale; |
| 2246 | sctp_cookie_preserve_param_t bht; |
| 2247 | sctp_errhdr_t *err; |
| 2248 | struct sctp_chunk *reply; |
| 2249 | struct sctp_bind_addr *bp; |
| 2250 | int attempts = asoc->init_err_counter + 1; |
| 2251 | |
| 2252 | if (attempts > asoc->max_init_attempts) { |
| 2253 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| 2254 | SCTP_ERROR(ETIMEDOUT)); |
| 2255 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, |
| 2256 | SCTP_PERR(SCTP_ERROR_STALE_COOKIE)); |
| 2257 | return SCTP_DISPOSITION_DELETE_TCB; |
| 2258 | } |
| 2259 | |
| 2260 | err = (sctp_errhdr_t *)(chunk->skb->data); |
| 2261 | |
| 2262 | /* When calculating the time extension, an implementation |
| 2263 | * SHOULD use the RTT information measured based on the |
| 2264 | * previous COOKIE ECHO / ERROR exchange, and should add no |
| 2265 | * more than 1 second beyond the measured RTT, due to long |
| 2266 | * State Cookie lifetimes making the endpoint more subject to |
| 2267 | * a replay attack. |
| 2268 | * Measure of Staleness's unit is usec. (1/1000000 sec) |
| 2269 | * Suggested Cookie Life-span Increment's unit is msec. |
| 2270 | * (1/1000 sec) |
| 2271 | * In general, if you use the suggested cookie life, the value |
| 2272 | * found in the field of measure of staleness should be doubled |
| 2273 | * to give ample time to retransmit the new cookie and thus |
| 2274 | * yield a higher probability of success on the reattempt. |
| 2275 | */ |
| 2276 | stale = ntohl(*(__be32 *)((u8 *)err + sizeof(sctp_errhdr_t))); |
| 2277 | stale = (stale * 2) / 1000; |
| 2278 | |
| 2279 | bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE; |
| 2280 | bht.param_hdr.length = htons(sizeof(bht)); |
| 2281 | bht.lifespan_increment = htonl(stale); |
| 2282 | |
| 2283 | /* Build that new INIT chunk. */ |
| 2284 | bp = (struct sctp_bind_addr *) &asoc->base.bind_addr; |
| 2285 | reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht)); |
| 2286 | if (!reply) |
| 2287 | goto nomem; |
| 2288 | |
| 2289 | sctp_addto_chunk(reply, sizeof(bht), &bht); |
| 2290 | |
| 2291 | /* Clear peer's init_tag cached in assoc as we are sending a new INIT */ |
| 2292 | sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL()); |
| 2293 | |
| 2294 | /* Stop pending T3-rtx and heartbeat timers */ |
| 2295 | sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL()); |
| 2296 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL()); |
| 2297 | |
| 2298 | /* Delete non-primary peer ip addresses since we are transitioning |
| 2299 | * back to the COOKIE-WAIT state |
| 2300 | */ |
| 2301 | sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL()); |
| 2302 | |
| 2303 | /* If we've sent any data bundled with COOKIE-ECHO we will need to |
| 2304 | * resend |
| 2305 | */ |
| 2306 | sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN, |
| 2307 | SCTP_TRANSPORT(asoc->peer.primary_path)); |
| 2308 | |
| 2309 | /* Cast away the const modifier, as we want to just |
| 2310 | * rerun it through as a sideffect. |
| 2311 | */ |
| 2312 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL()); |
| 2313 | |
| 2314 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| 2315 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); |
| 2316 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| 2317 | SCTP_STATE(SCTP_STATE_COOKIE_WAIT)); |
| 2318 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
| 2319 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
| 2320 | |
| 2321 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
| 2322 | |
| 2323 | return SCTP_DISPOSITION_CONSUME; |
| 2324 | |
| 2325 | nomem: |
| 2326 | return SCTP_DISPOSITION_NOMEM; |
| 2327 | } |
| 2328 | |
| 2329 | /* |
| 2330 | * Process an ABORT. |
| 2331 | * |
| 2332 | * Section: 9.1 |
| 2333 | * After checking the Verification Tag, the receiving endpoint shall |
| 2334 | * remove the association from its record, and shall report the |
| 2335 | * termination to its upper layer. |
| 2336 | * |
| 2337 | * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules |
| 2338 | * B) Rules for packet carrying ABORT: |
| 2339 | * |
| 2340 | * - The endpoint shall always fill in the Verification Tag field of the |
| 2341 | * outbound packet with the destination endpoint's tag value if it |
| 2342 | * is known. |
| 2343 | * |
| 2344 | * - If the ABORT is sent in response to an OOTB packet, the endpoint |
| 2345 | * MUST follow the procedure described in Section 8.4. |
| 2346 | * |
| 2347 | * - The receiver MUST accept the packet if the Verification Tag |
| 2348 | * matches either its own tag, OR the tag of its peer. Otherwise, the |
| 2349 | * receiver MUST silently discard the packet and take no further |
| 2350 | * action. |
| 2351 | * |
| 2352 | * Inputs |
| 2353 | * (endpoint, asoc, chunk) |
| 2354 | * |
| 2355 | * Outputs |
| 2356 | * (asoc, reply_msg, msg_up, timers, counters) |
| 2357 | * |
| 2358 | * The return value is the disposition of the chunk. |
| 2359 | */ |
| 2360 | sctp_disposition_t sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep, |
| 2361 | const struct sctp_association *asoc, |
| 2362 | const sctp_subtype_t type, |
| 2363 | void *arg, |
| 2364 | sctp_cmd_seq_t *commands) |
| 2365 | { |
| 2366 | struct sctp_chunk *chunk = arg; |
| 2367 | |
| 2368 | if (!sctp_vtag_verify_either(chunk, asoc)) |
| 2369 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 2370 | |
| 2371 | /* Make sure that the ABORT chunk has a valid length. |
| 2372 | * Since this is an ABORT chunk, we have to discard it |
| 2373 | * because of the following text: |
| 2374 | * RFC 2960, Section 3.3.7 |
| 2375 | * If an endpoint receives an ABORT with a format error or for an |
| 2376 | * association that doesn't exist, it MUST silently discard it. |
| 2377 | * Becasue the length is "invalid", we can't really discard just |
| 2378 | * as we do not know its true length. So, to be safe, discard the |
| 2379 | * packet. |
| 2380 | */ |
| 2381 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t))) |
| 2382 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 2383 | |
| 2384 | /* ADD-IP: Special case for ABORT chunks |
| 2385 | * F4) One special consideration is that ABORT Chunks arriving |
| 2386 | * destined to the IP address being deleted MUST be |
| 2387 | * ignored (see Section 5.3.1 for further details). |
| 2388 | */ |
| 2389 | if (SCTP_ADDR_DEL == |
| 2390 | sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest)) |
| 2391 | return sctp_sf_discard_chunk(ep, asoc, type, arg, commands); |
| 2392 | |
| 2393 | return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands); |
| 2394 | } |
| 2395 | |
| 2396 | static sctp_disposition_t __sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep, |
| 2397 | const struct sctp_association *asoc, |
| 2398 | const sctp_subtype_t type, |
| 2399 | void *arg, |
| 2400 | sctp_cmd_seq_t *commands) |
| 2401 | { |
| 2402 | struct sctp_chunk *chunk = arg; |
| 2403 | unsigned len; |
| 2404 | __be16 error = SCTP_ERROR_NO_ERROR; |
| 2405 | |
| 2406 | /* See if we have an error cause code in the chunk. */ |
| 2407 | len = ntohs(chunk->chunk_hdr->length); |
| 2408 | if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) |
| 2409 | error = ((sctp_errhdr_t *)chunk->skb->data)->cause; |
| 2410 | |
| 2411 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET)); |
| 2412 | /* ASSOC_FAILED will DELETE_TCB. */ |
| 2413 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error)); |
| 2414 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
| 2415 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); |
| 2416 | |
| 2417 | return SCTP_DISPOSITION_ABORT; |
| 2418 | } |
| 2419 | |
| 2420 | /* |
| 2421 | * Process an ABORT. (COOKIE-WAIT state) |
| 2422 | * |
| 2423 | * See sctp_sf_do_9_1_abort() above. |
| 2424 | */ |
| 2425 | sctp_disposition_t sctp_sf_cookie_wait_abort(const struct sctp_endpoint *ep, |
| 2426 | const struct sctp_association *asoc, |
| 2427 | const sctp_subtype_t type, |
| 2428 | void *arg, |
| 2429 | sctp_cmd_seq_t *commands) |
| 2430 | { |
| 2431 | struct sctp_chunk *chunk = arg; |
| 2432 | unsigned len; |
| 2433 | __be16 error = SCTP_ERROR_NO_ERROR; |
| 2434 | |
| 2435 | if (!sctp_vtag_verify_either(chunk, asoc)) |
| 2436 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 2437 | |
| 2438 | /* Make sure that the ABORT chunk has a valid length. |
| 2439 | * Since this is an ABORT chunk, we have to discard it |
| 2440 | * because of the following text: |
| 2441 | * RFC 2960, Section 3.3.7 |
| 2442 | * If an endpoint receives an ABORT with a format error or for an |
| 2443 | * association that doesn't exist, it MUST silently discard it. |
| 2444 | * Becasue the length is "invalid", we can't really discard just |
| 2445 | * as we do not know its true length. So, to be safe, discard the |
| 2446 | * packet. |
| 2447 | */ |
| 2448 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t))) |
| 2449 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 2450 | |
| 2451 | /* See if we have an error cause code in the chunk. */ |
| 2452 | len = ntohs(chunk->chunk_hdr->length); |
| 2453 | if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) |
| 2454 | error = ((sctp_errhdr_t *)chunk->skb->data)->cause; |
| 2455 | |
| 2456 | return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED, asoc, |
| 2457 | chunk->transport); |
| 2458 | } |
| 2459 | |
| 2460 | /* |
| 2461 | * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state) |
| 2462 | */ |
| 2463 | sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint *ep, |
| 2464 | const struct sctp_association *asoc, |
| 2465 | const sctp_subtype_t type, |
| 2466 | void *arg, |
| 2467 | sctp_cmd_seq_t *commands) |
| 2468 | { |
| 2469 | return sctp_stop_t1_and_abort(commands, SCTP_ERROR_NO_ERROR, |
| 2470 | ENOPROTOOPT, asoc, |
| 2471 | (struct sctp_transport *)arg); |
| 2472 | } |
| 2473 | |
| 2474 | /* |
| 2475 | * Process an ABORT. (COOKIE-ECHOED state) |
| 2476 | */ |
| 2477 | sctp_disposition_t sctp_sf_cookie_echoed_abort(const struct sctp_endpoint *ep, |
| 2478 | const struct sctp_association *asoc, |
| 2479 | const sctp_subtype_t type, |
| 2480 | void *arg, |
| 2481 | sctp_cmd_seq_t *commands) |
| 2482 | { |
| 2483 | /* There is a single T1 timer, so we should be able to use |
| 2484 | * common function with the COOKIE-WAIT state. |
| 2485 | */ |
| 2486 | return sctp_sf_cookie_wait_abort(ep, asoc, type, arg, commands); |
| 2487 | } |
| 2488 | |
| 2489 | /* |
| 2490 | * Stop T1 timer and abort association with "INIT failed". |
| 2491 | * |
| 2492 | * This is common code called by several sctp_sf_*_abort() functions above. |
| 2493 | */ |
| 2494 | static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands, |
| 2495 | __be16 error, int sk_err, |
| 2496 | const struct sctp_association *asoc, |
| 2497 | struct sctp_transport *transport) |
| 2498 | { |
| 2499 | SCTP_DEBUG_PRINTK("ABORT received (INIT).\n"); |
| 2500 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| 2501 | SCTP_STATE(SCTP_STATE_CLOSED)); |
| 2502 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
| 2503 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| 2504 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
| 2505 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err)); |
| 2506 | /* CMD_INIT_FAILED will DELETE_TCB. */ |
| 2507 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, |
| 2508 | SCTP_PERR(error)); |
| 2509 | return SCTP_DISPOSITION_ABORT; |
| 2510 | } |
| 2511 | |
| 2512 | /* |
| 2513 | * sctp_sf_do_9_2_shut |
| 2514 | * |
| 2515 | * Section: 9.2 |
| 2516 | * Upon the reception of the SHUTDOWN, the peer endpoint shall |
| 2517 | * - enter the SHUTDOWN-RECEIVED state, |
| 2518 | * |
| 2519 | * - stop accepting new data from its SCTP user |
| 2520 | * |
| 2521 | * - verify, by checking the Cumulative TSN Ack field of the chunk, |
| 2522 | * that all its outstanding DATA chunks have been received by the |
| 2523 | * SHUTDOWN sender. |
| 2524 | * |
| 2525 | * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT |
| 2526 | * send a SHUTDOWN in response to a ULP request. And should discard |
| 2527 | * subsequent SHUTDOWN chunks. |
| 2528 | * |
| 2529 | * If there are still outstanding DATA chunks left, the SHUTDOWN |
| 2530 | * receiver shall continue to follow normal data transmission |
| 2531 | * procedures defined in Section 6 until all outstanding DATA chunks |
| 2532 | * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept |
| 2533 | * new data from its SCTP user. |
| 2534 | * |
| 2535 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
| 2536 | * |
| 2537 | * Inputs |
| 2538 | * (endpoint, asoc, chunk) |
| 2539 | * |
| 2540 | * Outputs |
| 2541 | * (asoc, reply_msg, msg_up, timers, counters) |
| 2542 | * |
| 2543 | * The return value is the disposition of the chunk. |
| 2544 | */ |
| 2545 | sctp_disposition_t sctp_sf_do_9_2_shutdown(const struct sctp_endpoint *ep, |
| 2546 | const struct sctp_association *asoc, |
| 2547 | const sctp_subtype_t type, |
| 2548 | void *arg, |
| 2549 | sctp_cmd_seq_t *commands) |
| 2550 | { |
| 2551 | struct sctp_chunk *chunk = arg; |
| 2552 | sctp_shutdownhdr_t *sdh; |
| 2553 | sctp_disposition_t disposition; |
| 2554 | struct sctp_ulpevent *ev; |
| 2555 | |
| 2556 | if (!sctp_vtag_verify(chunk, asoc)) |
| 2557 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 2558 | |
| 2559 | /* Make sure that the SHUTDOWN chunk has a valid length. */ |
| 2560 | if (!sctp_chunk_length_valid(chunk, |
| 2561 | sizeof(struct sctp_shutdown_chunk_t))) |
| 2562 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 2563 | commands); |
| 2564 | |
| 2565 | /* Convert the elaborate header. */ |
| 2566 | sdh = (sctp_shutdownhdr_t *)chunk->skb->data; |
| 2567 | skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t)); |
| 2568 | chunk->subh.shutdown_hdr = sdh; |
| 2569 | |
| 2570 | /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT |
| 2571 | * When a peer sends a SHUTDOWN, SCTP delivers this notification to |
| 2572 | * inform the application that it should cease sending data. |
| 2573 | */ |
| 2574 | ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC); |
| 2575 | if (!ev) { |
| 2576 | disposition = SCTP_DISPOSITION_NOMEM; |
| 2577 | goto out; |
| 2578 | } |
| 2579 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); |
| 2580 | |
| 2581 | /* Upon the reception of the SHUTDOWN, the peer endpoint shall |
| 2582 | * - enter the SHUTDOWN-RECEIVED state, |
| 2583 | * - stop accepting new data from its SCTP user |
| 2584 | * |
| 2585 | * [This is implicit in the new state.] |
| 2586 | */ |
| 2587 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| 2588 | SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED)); |
| 2589 | disposition = SCTP_DISPOSITION_CONSUME; |
| 2590 | |
| 2591 | if (sctp_outq_is_empty(&asoc->outqueue)) { |
| 2592 | disposition = sctp_sf_do_9_2_shutdown_ack(ep, asoc, type, |
| 2593 | arg, commands); |
| 2594 | } |
| 2595 | |
| 2596 | if (SCTP_DISPOSITION_NOMEM == disposition) |
| 2597 | goto out; |
| 2598 | |
| 2599 | /* - verify, by checking the Cumulative TSN Ack field of the |
| 2600 | * chunk, that all its outstanding DATA chunks have been |
| 2601 | * received by the SHUTDOWN sender. |
| 2602 | */ |
| 2603 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN, |
| 2604 | SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack)); |
| 2605 | |
| 2606 | out: |
| 2607 | return disposition; |
| 2608 | } |
| 2609 | |
| 2610 | /* RFC 2960 9.2 |
| 2611 | * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk |
| 2612 | * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination |
| 2613 | * transport addresses (either in the IP addresses or in the INIT chunk) |
| 2614 | * that belong to this association, it should discard the INIT chunk and |
| 2615 | * retransmit the SHUTDOWN ACK chunk. |
| 2616 | */ |
| 2617 | sctp_disposition_t sctp_sf_do_9_2_reshutack(const struct sctp_endpoint *ep, |
| 2618 | const struct sctp_association *asoc, |
| 2619 | const sctp_subtype_t type, |
| 2620 | void *arg, |
| 2621 | sctp_cmd_seq_t *commands) |
| 2622 | { |
| 2623 | struct sctp_chunk *chunk = (struct sctp_chunk *) arg; |
| 2624 | struct sctp_chunk *reply; |
| 2625 | |
| 2626 | /* Make sure that the chunk has a valid length */ |
| 2627 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
| 2628 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 2629 | commands); |
| 2630 | |
| 2631 | /* Since we are not going to really process this INIT, there |
| 2632 | * is no point in verifying chunk boundries. Just generate |
| 2633 | * the SHUTDOWN ACK. |
| 2634 | */ |
| 2635 | reply = sctp_make_shutdown_ack(asoc, chunk); |
| 2636 | if (NULL == reply) |
| 2637 | goto nomem; |
| 2638 | |
| 2639 | /* Set the transport for the SHUTDOWN ACK chunk and the timeout for |
| 2640 | * the T2-SHUTDOWN timer. |
| 2641 | */ |
| 2642 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); |
| 2643 | |
| 2644 | /* and restart the T2-shutdown timer. */ |
| 2645 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
| 2646 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
| 2647 | |
| 2648 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
| 2649 | |
| 2650 | return SCTP_DISPOSITION_CONSUME; |
| 2651 | nomem: |
| 2652 | return SCTP_DISPOSITION_NOMEM; |
| 2653 | } |
| 2654 | |
| 2655 | /* |
| 2656 | * sctp_sf_do_ecn_cwr |
| 2657 | * |
| 2658 | * Section: Appendix A: Explicit Congestion Notification |
| 2659 | * |
| 2660 | * CWR: |
| 2661 | * |
| 2662 | * RFC 2481 details a specific bit for a sender to send in the header of |
| 2663 | * its next outbound TCP segment to indicate to its peer that it has |
| 2664 | * reduced its congestion window. This is termed the CWR bit. For |
| 2665 | * SCTP the same indication is made by including the CWR chunk. |
| 2666 | * This chunk contains one data element, i.e. the TSN number that |
| 2667 | * was sent in the ECNE chunk. This element represents the lowest |
| 2668 | * TSN number in the datagram that was originally marked with the |
| 2669 | * CE bit. |
| 2670 | * |
| 2671 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
| 2672 | * Inputs |
| 2673 | * (endpoint, asoc, chunk) |
| 2674 | * |
| 2675 | * Outputs |
| 2676 | * (asoc, reply_msg, msg_up, timers, counters) |
| 2677 | * |
| 2678 | * The return value is the disposition of the chunk. |
| 2679 | */ |
| 2680 | sctp_disposition_t sctp_sf_do_ecn_cwr(const struct sctp_endpoint *ep, |
| 2681 | const struct sctp_association *asoc, |
| 2682 | const sctp_subtype_t type, |
| 2683 | void *arg, |
| 2684 | sctp_cmd_seq_t *commands) |
| 2685 | { |
| 2686 | sctp_cwrhdr_t *cwr; |
| 2687 | struct sctp_chunk *chunk = arg; |
| 2688 | u32 lowest_tsn; |
| 2689 | |
| 2690 | if (!sctp_vtag_verify(chunk, asoc)) |
| 2691 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 2692 | |
| 2693 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t))) |
| 2694 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 2695 | commands); |
| 2696 | |
| 2697 | cwr = (sctp_cwrhdr_t *) chunk->skb->data; |
| 2698 | skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t)); |
| 2699 | |
| 2700 | lowest_tsn = ntohl(cwr->lowest_tsn); |
| 2701 | |
| 2702 | /* Does this CWR ack the last sent congestion notification? */ |
| 2703 | if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) { |
| 2704 | /* Stop sending ECNE. */ |
| 2705 | sctp_add_cmd_sf(commands, |
| 2706 | SCTP_CMD_ECN_CWR, |
| 2707 | SCTP_U32(lowest_tsn)); |
| 2708 | } |
| 2709 | return SCTP_DISPOSITION_CONSUME; |
| 2710 | } |
| 2711 | |
| 2712 | /* |
| 2713 | * sctp_sf_do_ecne |
| 2714 | * |
| 2715 | * Section: Appendix A: Explicit Congestion Notification |
| 2716 | * |
| 2717 | * ECN-Echo |
| 2718 | * |
| 2719 | * RFC 2481 details a specific bit for a receiver to send back in its |
| 2720 | * TCP acknowledgements to notify the sender of the Congestion |
| 2721 | * Experienced (CE) bit having arrived from the network. For SCTP this |
| 2722 | * same indication is made by including the ECNE chunk. This chunk |
| 2723 | * contains one data element, i.e. the lowest TSN associated with the IP |
| 2724 | * datagram marked with the CE bit..... |
| 2725 | * |
| 2726 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
| 2727 | * Inputs |
| 2728 | * (endpoint, asoc, chunk) |
| 2729 | * |
| 2730 | * Outputs |
| 2731 | * (asoc, reply_msg, msg_up, timers, counters) |
| 2732 | * |
| 2733 | * The return value is the disposition of the chunk. |
| 2734 | */ |
| 2735 | sctp_disposition_t sctp_sf_do_ecne(const struct sctp_endpoint *ep, |
| 2736 | const struct sctp_association *asoc, |
| 2737 | const sctp_subtype_t type, |
| 2738 | void *arg, |
| 2739 | sctp_cmd_seq_t *commands) |
| 2740 | { |
| 2741 | sctp_ecnehdr_t *ecne; |
| 2742 | struct sctp_chunk *chunk = arg; |
| 2743 | |
| 2744 | if (!sctp_vtag_verify(chunk, asoc)) |
| 2745 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 2746 | |
| 2747 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t))) |
| 2748 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 2749 | commands); |
| 2750 | |
| 2751 | ecne = (sctp_ecnehdr_t *) chunk->skb->data; |
| 2752 | skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t)); |
| 2753 | |
| 2754 | /* If this is a newer ECNE than the last CWR packet we sent out */ |
| 2755 | sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE, |
| 2756 | SCTP_U32(ntohl(ecne->lowest_tsn))); |
| 2757 | |
| 2758 | return SCTP_DISPOSITION_CONSUME; |
| 2759 | } |
| 2760 | |
| 2761 | /* |
| 2762 | * Section: 6.2 Acknowledgement on Reception of DATA Chunks |
| 2763 | * |
| 2764 | * The SCTP endpoint MUST always acknowledge the reception of each valid |
| 2765 | * DATA chunk. |
| 2766 | * |
| 2767 | * The guidelines on delayed acknowledgement algorithm specified in |
| 2768 | * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an |
| 2769 | * acknowledgement SHOULD be generated for at least every second packet |
| 2770 | * (not every second DATA chunk) received, and SHOULD be generated within |
| 2771 | * 200 ms of the arrival of any unacknowledged DATA chunk. In some |
| 2772 | * situations it may be beneficial for an SCTP transmitter to be more |
| 2773 | * conservative than the algorithms detailed in this document allow. |
| 2774 | * However, an SCTP transmitter MUST NOT be more aggressive than the |
| 2775 | * following algorithms allow. |
| 2776 | * |
| 2777 | * A SCTP receiver MUST NOT generate more than one SACK for every |
| 2778 | * incoming packet, other than to update the offered window as the |
| 2779 | * receiving application consumes new data. |
| 2780 | * |
| 2781 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
| 2782 | * |
| 2783 | * Inputs |
| 2784 | * (endpoint, asoc, chunk) |
| 2785 | * |
| 2786 | * Outputs |
| 2787 | * (asoc, reply_msg, msg_up, timers, counters) |
| 2788 | * |
| 2789 | * The return value is the disposition of the chunk. |
| 2790 | */ |
| 2791 | sctp_disposition_t sctp_sf_eat_data_6_2(const struct sctp_endpoint *ep, |
| 2792 | const struct sctp_association *asoc, |
| 2793 | const sctp_subtype_t type, |
| 2794 | void *arg, |
| 2795 | sctp_cmd_seq_t *commands) |
| 2796 | { |
| 2797 | struct sctp_chunk *chunk = arg; |
| 2798 | int error; |
| 2799 | |
| 2800 | if (!sctp_vtag_verify(chunk, asoc)) { |
| 2801 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
| 2802 | SCTP_NULL()); |
| 2803 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 2804 | } |
| 2805 | |
| 2806 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t))) |
| 2807 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 2808 | commands); |
| 2809 | |
| 2810 | error = sctp_eat_data(asoc, chunk, commands ); |
| 2811 | switch (error) { |
| 2812 | case SCTP_IERROR_NO_ERROR: |
| 2813 | break; |
| 2814 | case SCTP_IERROR_HIGH_TSN: |
| 2815 | case SCTP_IERROR_BAD_STREAM: |
| 2816 | SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS); |
| 2817 | goto discard_noforce; |
| 2818 | case SCTP_IERROR_DUP_TSN: |
| 2819 | case SCTP_IERROR_IGNORE_TSN: |
| 2820 | SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS); |
| 2821 | goto discard_force; |
| 2822 | case SCTP_IERROR_NO_DATA: |
| 2823 | goto consume; |
| 2824 | default: |
| 2825 | BUG(); |
| 2826 | } |
| 2827 | |
| 2828 | if (asoc->autoclose) { |
| 2829 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
| 2830 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
| 2831 | } |
| 2832 | |
| 2833 | /* If this is the last chunk in a packet, we need to count it |
| 2834 | * toward sack generation. Note that we need to SACK every |
| 2835 | * OTHER packet containing data chunks, EVEN IF WE DISCARD |
| 2836 | * THEM. We elect to NOT generate SACK's if the chunk fails |
| 2837 | * the verification tag test. |
| 2838 | * |
| 2839 | * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks |
| 2840 | * |
| 2841 | * The SCTP endpoint MUST always acknowledge the reception of |
| 2842 | * each valid DATA chunk. |
| 2843 | * |
| 2844 | * The guidelines on delayed acknowledgement algorithm |
| 2845 | * specified in Section 4.2 of [RFC2581] SHOULD be followed. |
| 2846 | * Specifically, an acknowledgement SHOULD be generated for at |
| 2847 | * least every second packet (not every second DATA chunk) |
| 2848 | * received, and SHOULD be generated within 200 ms of the |
| 2849 | * arrival of any unacknowledged DATA chunk. In some |
| 2850 | * situations it may be beneficial for an SCTP transmitter to |
| 2851 | * be more conservative than the algorithms detailed in this |
| 2852 | * document allow. However, an SCTP transmitter MUST NOT be |
| 2853 | * more aggressive than the following algorithms allow. |
| 2854 | */ |
| 2855 | if (chunk->end_of_packet) |
| 2856 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE()); |
| 2857 | |
| 2858 | return SCTP_DISPOSITION_CONSUME; |
| 2859 | |
| 2860 | discard_force: |
| 2861 | /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks |
| 2862 | * |
| 2863 | * When a packet arrives with duplicate DATA chunk(s) and with |
| 2864 | * no new DATA chunk(s), the endpoint MUST immediately send a |
| 2865 | * SACK with no delay. If a packet arrives with duplicate |
| 2866 | * DATA chunk(s) bundled with new DATA chunks, the endpoint |
| 2867 | * MAY immediately send a SACK. Normally receipt of duplicate |
| 2868 | * DATA chunks will occur when the original SACK chunk was lost |
| 2869 | * and the peer's RTO has expired. The duplicate TSN number(s) |
| 2870 | * SHOULD be reported in the SACK as duplicate. |
| 2871 | */ |
| 2872 | /* In our case, we split the MAY SACK advice up whether or not |
| 2873 | * the last chunk is a duplicate.' |
| 2874 | */ |
| 2875 | if (chunk->end_of_packet) |
| 2876 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); |
| 2877 | return SCTP_DISPOSITION_DISCARD; |
| 2878 | |
| 2879 | discard_noforce: |
| 2880 | if (chunk->end_of_packet) |
| 2881 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE()); |
| 2882 | |
| 2883 | return SCTP_DISPOSITION_DISCARD; |
| 2884 | consume: |
| 2885 | return SCTP_DISPOSITION_CONSUME; |
| 2886 | |
| 2887 | } |
| 2888 | |
| 2889 | /* |
| 2890 | * sctp_sf_eat_data_fast_4_4 |
| 2891 | * |
| 2892 | * Section: 4 (4) |
| 2893 | * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received |
| 2894 | * DATA chunks without delay. |
| 2895 | * |
| 2896 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
| 2897 | * Inputs |
| 2898 | * (endpoint, asoc, chunk) |
| 2899 | * |
| 2900 | * Outputs |
| 2901 | * (asoc, reply_msg, msg_up, timers, counters) |
| 2902 | * |
| 2903 | * The return value is the disposition of the chunk. |
| 2904 | */ |
| 2905 | sctp_disposition_t sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint *ep, |
| 2906 | const struct sctp_association *asoc, |
| 2907 | const sctp_subtype_t type, |
| 2908 | void *arg, |
| 2909 | sctp_cmd_seq_t *commands) |
| 2910 | { |
| 2911 | struct sctp_chunk *chunk = arg; |
| 2912 | int error; |
| 2913 | |
| 2914 | if (!sctp_vtag_verify(chunk, asoc)) { |
| 2915 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
| 2916 | SCTP_NULL()); |
| 2917 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 2918 | } |
| 2919 | |
| 2920 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t))) |
| 2921 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 2922 | commands); |
| 2923 | |
| 2924 | error = sctp_eat_data(asoc, chunk, commands ); |
| 2925 | switch (error) { |
| 2926 | case SCTP_IERROR_NO_ERROR: |
| 2927 | case SCTP_IERROR_HIGH_TSN: |
| 2928 | case SCTP_IERROR_DUP_TSN: |
| 2929 | case SCTP_IERROR_IGNORE_TSN: |
| 2930 | case SCTP_IERROR_BAD_STREAM: |
| 2931 | break; |
| 2932 | case SCTP_IERROR_NO_DATA: |
| 2933 | goto consume; |
| 2934 | default: |
| 2935 | BUG(); |
| 2936 | } |
| 2937 | |
| 2938 | /* Go a head and force a SACK, since we are shutting down. */ |
| 2939 | |
| 2940 | /* Implementor's Guide. |
| 2941 | * |
| 2942 | * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately |
| 2943 | * respond to each received packet containing one or more DATA chunk(s) |
| 2944 | * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer |
| 2945 | */ |
| 2946 | if (chunk->end_of_packet) { |
| 2947 | /* We must delay the chunk creation since the cumulative |
| 2948 | * TSN has not been updated yet. |
| 2949 | */ |
| 2950 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL()); |
| 2951 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); |
| 2952 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
| 2953 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
| 2954 | } |
| 2955 | |
| 2956 | consume: |
| 2957 | return SCTP_DISPOSITION_CONSUME; |
| 2958 | } |
| 2959 | |
| 2960 | /* |
| 2961 | * Section: 6.2 Processing a Received SACK |
| 2962 | * D) Any time a SACK arrives, the endpoint performs the following: |
| 2963 | * |
| 2964 | * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point, |
| 2965 | * then drop the SACK. Since Cumulative TSN Ack is monotonically |
| 2966 | * increasing, a SACK whose Cumulative TSN Ack is less than the |
| 2967 | * Cumulative TSN Ack Point indicates an out-of-order SACK. |
| 2968 | * |
| 2969 | * ii) Set rwnd equal to the newly received a_rwnd minus the number |
| 2970 | * of bytes still outstanding after processing the Cumulative TSN Ack |
| 2971 | * and the Gap Ack Blocks. |
| 2972 | * |
| 2973 | * iii) If the SACK is missing a TSN that was previously |
| 2974 | * acknowledged via a Gap Ack Block (e.g., the data receiver |
| 2975 | * reneged on the data), then mark the corresponding DATA chunk |
| 2976 | * as available for retransmit: Mark it as missing for fast |
| 2977 | * retransmit as described in Section 7.2.4 and if no retransmit |
| 2978 | * timer is running for the destination address to which the DATA |
| 2979 | * chunk was originally transmitted, then T3-rtx is started for |
| 2980 | * that destination address. |
| 2981 | * |
| 2982 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
| 2983 | * |
| 2984 | * Inputs |
| 2985 | * (endpoint, asoc, chunk) |
| 2986 | * |
| 2987 | * Outputs |
| 2988 | * (asoc, reply_msg, msg_up, timers, counters) |
| 2989 | * |
| 2990 | * The return value is the disposition of the chunk. |
| 2991 | */ |
| 2992 | sctp_disposition_t sctp_sf_eat_sack_6_2(const struct sctp_endpoint *ep, |
| 2993 | const struct sctp_association *asoc, |
| 2994 | const sctp_subtype_t type, |
| 2995 | void *arg, |
| 2996 | sctp_cmd_seq_t *commands) |
| 2997 | { |
| 2998 | struct sctp_chunk *chunk = arg; |
| 2999 | sctp_sackhdr_t *sackh; |
| 3000 | __u32 ctsn; |
| 3001 | |
| 3002 | if (!sctp_vtag_verify(chunk, asoc)) |
| 3003 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 3004 | |
| 3005 | /* Make sure that the SACK chunk has a valid length. */ |
| 3006 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t))) |
| 3007 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 3008 | commands); |
| 3009 | |
| 3010 | /* Pull the SACK chunk from the data buffer */ |
| 3011 | sackh = sctp_sm_pull_sack(chunk); |
| 3012 | /* Was this a bogus SACK? */ |
| 3013 | if (!sackh) |
| 3014 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 3015 | chunk->subh.sack_hdr = sackh; |
| 3016 | ctsn = ntohl(sackh->cum_tsn_ack); |
| 3017 | |
| 3018 | /* i) If Cumulative TSN Ack is less than the Cumulative TSN |
| 3019 | * Ack Point, then drop the SACK. Since Cumulative TSN |
| 3020 | * Ack is monotonically increasing, a SACK whose |
| 3021 | * Cumulative TSN Ack is less than the Cumulative TSN Ack |
| 3022 | * Point indicates an out-of-order SACK. |
| 3023 | */ |
| 3024 | if (TSN_lt(ctsn, asoc->ctsn_ack_point)) { |
| 3025 | SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn); |
| 3026 | SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point); |
| 3027 | return SCTP_DISPOSITION_DISCARD; |
| 3028 | } |
| 3029 | |
| 3030 | /* If Cumulative TSN Ack beyond the max tsn currently |
| 3031 | * send, terminating the association and respond to the |
| 3032 | * sender with an ABORT. |
| 3033 | */ |
| 3034 | if (!TSN_lt(ctsn, asoc->next_tsn)) |
| 3035 | return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands); |
| 3036 | |
| 3037 | /* Return this SACK for further processing. */ |
| 3038 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_SACKH(sackh)); |
| 3039 | |
| 3040 | /* Note: We do the rest of the work on the PROCESS_SACK |
| 3041 | * sideeffect. |
| 3042 | */ |
| 3043 | return SCTP_DISPOSITION_CONSUME; |
| 3044 | } |
| 3045 | |
| 3046 | /* |
| 3047 | * Generate an ABORT in response to a packet. |
| 3048 | * |
| 3049 | * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41 |
| 3050 | * |
| 3051 | * 8) The receiver should respond to the sender of the OOTB packet with |
| 3052 | * an ABORT. When sending the ABORT, the receiver of the OOTB packet |
| 3053 | * MUST fill in the Verification Tag field of the outbound packet |
| 3054 | * with the value found in the Verification Tag field of the OOTB |
| 3055 | * packet and set the T-bit in the Chunk Flags to indicate that the |
| 3056 | * Verification Tag is reflected. After sending this ABORT, the |
| 3057 | * receiver of the OOTB packet shall discard the OOTB packet and take |
| 3058 | * no further action. |
| 3059 | * |
| 3060 | * Verification Tag: |
| 3061 | * |
| 3062 | * The return value is the disposition of the chunk. |
| 3063 | */ |
| 3064 | static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep, |
| 3065 | const struct sctp_association *asoc, |
| 3066 | const sctp_subtype_t type, |
| 3067 | void *arg, |
| 3068 | sctp_cmd_seq_t *commands) |
| 3069 | { |
| 3070 | struct sctp_packet *packet = NULL; |
| 3071 | struct sctp_chunk *chunk = arg; |
| 3072 | struct sctp_chunk *abort; |
| 3073 | |
| 3074 | packet = sctp_ootb_pkt_new(asoc, chunk); |
| 3075 | |
| 3076 | if (packet) { |
| 3077 | /* Make an ABORT. The T bit will be set if the asoc |
| 3078 | * is NULL. |
| 3079 | */ |
| 3080 | abort = sctp_make_abort(asoc, chunk, 0); |
| 3081 | if (!abort) { |
| 3082 | sctp_ootb_pkt_free(packet); |
| 3083 | return SCTP_DISPOSITION_NOMEM; |
| 3084 | } |
| 3085 | |
| 3086 | /* Reflect vtag if T-Bit is set */ |
| 3087 | if (sctp_test_T_bit(abort)) |
| 3088 | packet->vtag = ntohl(chunk->sctp_hdr->vtag); |
| 3089 | |
| 3090 | /* Set the skb to the belonging sock for accounting. */ |
| 3091 | abort->skb->sk = ep->base.sk; |
| 3092 | |
| 3093 | sctp_packet_append_chunk(packet, abort); |
| 3094 | |
| 3095 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
| 3096 | SCTP_PACKET(packet)); |
| 3097 | |
| 3098 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
| 3099 | |
| 3100 | sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 3101 | return SCTP_DISPOSITION_CONSUME; |
| 3102 | } |
| 3103 | |
| 3104 | return SCTP_DISPOSITION_NOMEM; |
| 3105 | } |
| 3106 | |
| 3107 | /* |
| 3108 | * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR |
| 3109 | * event as ULP notification for each cause included in the chunk. |
| 3110 | * |
| 3111 | * API 5.3.1.3 - SCTP_REMOTE_ERROR |
| 3112 | * |
| 3113 | * The return value is the disposition of the chunk. |
| 3114 | */ |
| 3115 | sctp_disposition_t sctp_sf_operr_notify(const struct sctp_endpoint *ep, |
| 3116 | const struct sctp_association *asoc, |
| 3117 | const sctp_subtype_t type, |
| 3118 | void *arg, |
| 3119 | sctp_cmd_seq_t *commands) |
| 3120 | { |
| 3121 | struct sctp_chunk *chunk = arg; |
| 3122 | struct sctp_ulpevent *ev; |
| 3123 | |
| 3124 | if (!sctp_vtag_verify(chunk, asoc)) |
| 3125 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 3126 | |
| 3127 | /* Make sure that the ERROR chunk has a valid length. */ |
| 3128 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t))) |
| 3129 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 3130 | commands); |
| 3131 | |
| 3132 | while (chunk->chunk_end > chunk->skb->data) { |
| 3133 | ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0, |
| 3134 | GFP_ATOMIC); |
| 3135 | if (!ev) |
| 3136 | goto nomem; |
| 3137 | |
| 3138 | if (!sctp_add_cmd(commands, SCTP_CMD_EVENT_ULP, |
| 3139 | SCTP_ULPEVENT(ev))) { |
| 3140 | sctp_ulpevent_free(ev); |
| 3141 | goto nomem; |
| 3142 | } |
| 3143 | |
| 3144 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR, |
| 3145 | SCTP_CHUNK(chunk)); |
| 3146 | } |
| 3147 | return SCTP_DISPOSITION_CONSUME; |
| 3148 | |
| 3149 | nomem: |
| 3150 | return SCTP_DISPOSITION_NOMEM; |
| 3151 | } |
| 3152 | |
| 3153 | /* |
| 3154 | * Process an inbound SHUTDOWN ACK. |
| 3155 | * |
| 3156 | * From Section 9.2: |
| 3157 | * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall |
| 3158 | * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its |
| 3159 | * peer, and remove all record of the association. |
| 3160 | * |
| 3161 | * The return value is the disposition. |
| 3162 | */ |
| 3163 | sctp_disposition_t sctp_sf_do_9_2_final(const struct sctp_endpoint *ep, |
| 3164 | const struct sctp_association *asoc, |
| 3165 | const sctp_subtype_t type, |
| 3166 | void *arg, |
| 3167 | sctp_cmd_seq_t *commands) |
| 3168 | { |
| 3169 | struct sctp_chunk *chunk = arg; |
| 3170 | struct sctp_chunk *reply; |
| 3171 | struct sctp_ulpevent *ev; |
| 3172 | |
| 3173 | if (!sctp_vtag_verify(chunk, asoc)) |
| 3174 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 3175 | |
| 3176 | /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */ |
| 3177 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
| 3178 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 3179 | commands); |
| 3180 | /* 10.2 H) SHUTDOWN COMPLETE notification |
| 3181 | * |
| 3182 | * When SCTP completes the shutdown procedures (section 9.2) this |
| 3183 | * notification is passed to the upper layer. |
| 3184 | */ |
| 3185 | ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP, |
| 3186 | 0, 0, 0, NULL, GFP_ATOMIC); |
| 3187 | if (!ev) |
| 3188 | goto nomem; |
| 3189 | |
| 3190 | /* ...send a SHUTDOWN COMPLETE chunk to its peer, */ |
| 3191 | reply = sctp_make_shutdown_complete(asoc, chunk); |
| 3192 | if (!reply) |
| 3193 | goto nomem_chunk; |
| 3194 | |
| 3195 | /* Do all the commands now (after allocation), so that we |
| 3196 | * have consistent state if memory allocation failes |
| 3197 | */ |
| 3198 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev)); |
| 3199 | |
| 3200 | /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall |
| 3201 | * stop the T2-shutdown timer, |
| 3202 | */ |
| 3203 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| 3204 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
| 3205 | |
| 3206 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| 3207 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
| 3208 | |
| 3209 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| 3210 | SCTP_STATE(SCTP_STATE_CLOSED)); |
| 3211 | SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS); |
| 3212 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); |
| 3213 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
| 3214 | |
| 3215 | /* ...and remove all record of the association. */ |
| 3216 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
| 3217 | return SCTP_DISPOSITION_DELETE_TCB; |
| 3218 | |
| 3219 | nomem_chunk: |
| 3220 | sctp_ulpevent_free(ev); |
| 3221 | nomem: |
| 3222 | return SCTP_DISPOSITION_NOMEM; |
| 3223 | } |
| 3224 | |
| 3225 | /* |
| 3226 | * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41. |
| 3227 | * |
| 3228 | * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should |
| 3229 | * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE. |
| 3230 | * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB |
| 3231 | * packet must fill in the Verification Tag field of the outbound |
| 3232 | * packet with the Verification Tag received in the SHUTDOWN ACK and |
| 3233 | * set the T-bit in the Chunk Flags to indicate that the Verification |
| 3234 | * Tag is reflected. |
| 3235 | * |
| 3236 | * 8) The receiver should respond to the sender of the OOTB packet with |
| 3237 | * an ABORT. When sending the ABORT, the receiver of the OOTB packet |
| 3238 | * MUST fill in the Verification Tag field of the outbound packet |
| 3239 | * with the value found in the Verification Tag field of the OOTB |
| 3240 | * packet and set the T-bit in the Chunk Flags to indicate that the |
| 3241 | * Verification Tag is reflected. After sending this ABORT, the |
| 3242 | * receiver of the OOTB packet shall discard the OOTB packet and take |
| 3243 | * no further action. |
| 3244 | */ |
| 3245 | sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep, |
| 3246 | const struct sctp_association *asoc, |
| 3247 | const sctp_subtype_t type, |
| 3248 | void *arg, |
| 3249 | sctp_cmd_seq_t *commands) |
| 3250 | { |
| 3251 | struct sctp_chunk *chunk = arg; |
| 3252 | struct sk_buff *skb = chunk->skb; |
| 3253 | sctp_chunkhdr_t *ch; |
| 3254 | __u8 *ch_end; |
| 3255 | int ootb_shut_ack = 0; |
| 3256 | |
| 3257 | SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES); |
| 3258 | |
| 3259 | ch = (sctp_chunkhdr_t *) chunk->chunk_hdr; |
| 3260 | do { |
| 3261 | /* Report violation if the chunk is less then minimal */ |
| 3262 | if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t)) |
| 3263 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 3264 | commands); |
| 3265 | |
| 3266 | /* Now that we know we at least have a chunk header, |
| 3267 | * do things that are type appropriate. |
| 3268 | */ |
| 3269 | if (SCTP_CID_SHUTDOWN_ACK == ch->type) |
| 3270 | ootb_shut_ack = 1; |
| 3271 | |
| 3272 | /* RFC 2960, Section 3.3.7 |
| 3273 | * Moreover, under any circumstances, an endpoint that |
| 3274 | * receives an ABORT MUST NOT respond to that ABORT by |
| 3275 | * sending an ABORT of its own. |
| 3276 | */ |
| 3277 | if (SCTP_CID_ABORT == ch->type) |
| 3278 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 3279 | |
| 3280 | /* Report violation if chunk len overflows */ |
| 3281 | ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length)); |
| 3282 | if (ch_end > skb_tail_pointer(skb)) |
| 3283 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 3284 | commands); |
| 3285 | |
| 3286 | ch = (sctp_chunkhdr_t *) ch_end; |
| 3287 | } while (ch_end < skb_tail_pointer(skb)); |
| 3288 | |
| 3289 | if (ootb_shut_ack) |
| 3290 | return sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands); |
| 3291 | else |
| 3292 | return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands); |
| 3293 | } |
| 3294 | |
| 3295 | /* |
| 3296 | * Handle an "Out of the blue" SHUTDOWN ACK. |
| 3297 | * |
| 3298 | * Section: 8.4 5, sctpimpguide 2.41. |
| 3299 | * |
| 3300 | * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should |
| 3301 | * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE. |
| 3302 | * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB |
| 3303 | * packet must fill in the Verification Tag field of the outbound |
| 3304 | * packet with the Verification Tag received in the SHUTDOWN ACK and |
| 3305 | * set the T-bit in the Chunk Flags to indicate that the Verification |
| 3306 | * Tag is reflected. |
| 3307 | * |
| 3308 | * Inputs |
| 3309 | * (endpoint, asoc, type, arg, commands) |
| 3310 | * |
| 3311 | * Outputs |
| 3312 | * (sctp_disposition_t) |
| 3313 | * |
| 3314 | * The return value is the disposition of the chunk. |
| 3315 | */ |
| 3316 | static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep, |
| 3317 | const struct sctp_association *asoc, |
| 3318 | const sctp_subtype_t type, |
| 3319 | void *arg, |
| 3320 | sctp_cmd_seq_t *commands) |
| 3321 | { |
| 3322 | struct sctp_packet *packet = NULL; |
| 3323 | struct sctp_chunk *chunk = arg; |
| 3324 | struct sctp_chunk *shut; |
| 3325 | |
| 3326 | packet = sctp_ootb_pkt_new(asoc, chunk); |
| 3327 | |
| 3328 | if (packet) { |
| 3329 | /* Make an SHUTDOWN_COMPLETE. |
| 3330 | * The T bit will be set if the asoc is NULL. |
| 3331 | */ |
| 3332 | shut = sctp_make_shutdown_complete(asoc, chunk); |
| 3333 | if (!shut) { |
| 3334 | sctp_ootb_pkt_free(packet); |
| 3335 | return SCTP_DISPOSITION_NOMEM; |
| 3336 | } |
| 3337 | |
| 3338 | /* Reflect vtag if T-Bit is set */ |
| 3339 | if (sctp_test_T_bit(shut)) |
| 3340 | packet->vtag = ntohl(chunk->sctp_hdr->vtag); |
| 3341 | |
| 3342 | /* Set the skb to the belonging sock for accounting. */ |
| 3343 | shut->skb->sk = ep->base.sk; |
| 3344 | |
| 3345 | sctp_packet_append_chunk(packet, shut); |
| 3346 | |
| 3347 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
| 3348 | SCTP_PACKET(packet)); |
| 3349 | |
| 3350 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
| 3351 | |
| 3352 | /* If the chunk length is invalid, we don't want to process |
| 3353 | * the reset of the packet. |
| 3354 | */ |
| 3355 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
| 3356 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 3357 | |
| 3358 | /* We need to discard the rest of the packet to prevent |
| 3359 | * potential bomming attacks from additional bundled chunks. |
| 3360 | * This is documented in SCTP Threats ID. |
| 3361 | */ |
| 3362 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 3363 | } |
| 3364 | |
| 3365 | return SCTP_DISPOSITION_NOMEM; |
| 3366 | } |
| 3367 | |
| 3368 | /* |
| 3369 | * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state. |
| 3370 | * |
| 3371 | * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK |
| 3372 | * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the |
| 3373 | * procedures in section 8.4 SHOULD be followed, in other words it |
| 3374 | * should be treated as an Out Of The Blue packet. |
| 3375 | * [This means that we do NOT check the Verification Tag on these |
| 3376 | * chunks. --piggy ] |
| 3377 | * |
| 3378 | */ |
| 3379 | sctp_disposition_t sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint *ep, |
| 3380 | const struct sctp_association *asoc, |
| 3381 | const sctp_subtype_t type, |
| 3382 | void *arg, |
| 3383 | sctp_cmd_seq_t *commands) |
| 3384 | { |
| 3385 | struct sctp_chunk *chunk = arg; |
| 3386 | |
| 3387 | /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */ |
| 3388 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
| 3389 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 3390 | commands); |
| 3391 | |
| 3392 | /* Although we do have an association in this case, it corresponds |
| 3393 | * to a restarted association. So the packet is treated as an OOTB |
| 3394 | * packet and the state function that handles OOTB SHUTDOWN_ACK is |
| 3395 | * called with a NULL association. |
| 3396 | */ |
| 3397 | return sctp_sf_shut_8_4_5(ep, NULL, type, arg, commands); |
| 3398 | } |
| 3399 | |
| 3400 | /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */ |
| 3401 | sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep, |
| 3402 | const struct sctp_association *asoc, |
| 3403 | const sctp_subtype_t type, void *arg, |
| 3404 | sctp_cmd_seq_t *commands) |
| 3405 | { |
| 3406 | struct sctp_chunk *chunk = arg; |
| 3407 | struct sctp_chunk *asconf_ack = NULL; |
| 3408 | struct sctp_paramhdr *err_param = NULL; |
| 3409 | sctp_addiphdr_t *hdr; |
| 3410 | union sctp_addr_param *addr_param; |
| 3411 | __u32 serial; |
| 3412 | int length; |
| 3413 | |
| 3414 | if (!sctp_vtag_verify(chunk, asoc)) { |
| 3415 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
| 3416 | SCTP_NULL()); |
| 3417 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 3418 | } |
| 3419 | |
| 3420 | /* ADD-IP: Section 4.1.1 |
| 3421 | * This chunk MUST be sent in an authenticated way by using |
| 3422 | * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk |
| 3423 | * is received unauthenticated it MUST be silently discarded as |
| 3424 | * described in [I-D.ietf-tsvwg-sctp-auth]. |
| 3425 | */ |
| 3426 | if (!sctp_addip_noauth && !chunk->auth) |
| 3427 | return sctp_sf_discard_chunk(ep, asoc, type, arg, commands); |
| 3428 | |
| 3429 | /* Make sure that the ASCONF ADDIP chunk has a valid length. */ |
| 3430 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t))) |
| 3431 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 3432 | commands); |
| 3433 | |
| 3434 | hdr = (sctp_addiphdr_t *)chunk->skb->data; |
| 3435 | serial = ntohl(hdr->serial); |
| 3436 | |
| 3437 | addr_param = (union sctp_addr_param *)hdr->params; |
| 3438 | length = ntohs(addr_param->p.length); |
| 3439 | if (length < sizeof(sctp_paramhdr_t)) |
| 3440 | return sctp_sf_violation_paramlen(ep, asoc, type, |
| 3441 | (void *)addr_param, commands); |
| 3442 | |
| 3443 | /* Verify the ASCONF chunk before processing it. */ |
| 3444 | if (!sctp_verify_asconf(asoc, |
| 3445 | (sctp_paramhdr_t *)((void *)addr_param + length), |
| 3446 | (void *)chunk->chunk_end, |
| 3447 | &err_param)) |
| 3448 | return sctp_sf_violation_paramlen(ep, asoc, type, |
| 3449 | (void *)&err_param, commands); |
| 3450 | |
| 3451 | /* ADDIP 5.2 E1) Compare the value of the serial number to the value |
| 3452 | * the endpoint stored in a new association variable |
| 3453 | * 'Peer-Serial-Number'. |
| 3454 | */ |
| 3455 | if (serial == asoc->peer.addip_serial + 1) { |
| 3456 | /* If this is the first instance of ASCONF in the packet, |
| 3457 | * we can clean our old ASCONF-ACKs. |
| 3458 | */ |
| 3459 | if (!chunk->has_asconf) |
| 3460 | sctp_assoc_clean_asconf_ack_cache(asoc); |
| 3461 | |
| 3462 | /* ADDIP 5.2 E4) When the Sequence Number matches the next one |
| 3463 | * expected, process the ASCONF as described below and after |
| 3464 | * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to |
| 3465 | * the response packet and cache a copy of it (in the event it |
| 3466 | * later needs to be retransmitted). |
| 3467 | * |
| 3468 | * Essentially, do V1-V5. |
| 3469 | */ |
| 3470 | asconf_ack = sctp_process_asconf((struct sctp_association *) |
| 3471 | asoc, chunk); |
| 3472 | if (!asconf_ack) |
| 3473 | return SCTP_DISPOSITION_NOMEM; |
| 3474 | } else if (serial < asoc->peer.addip_serial + 1) { |
| 3475 | /* ADDIP 5.2 E2) |
| 3476 | * If the value found in the Sequence Number is less than the |
| 3477 | * ('Peer- Sequence-Number' + 1), simply skip to the next |
| 3478 | * ASCONF, and include in the outbound response packet |
| 3479 | * any previously cached ASCONF-ACK response that was |
| 3480 | * sent and saved that matches the Sequence Number of the |
| 3481 | * ASCONF. Note: It is possible that no cached ASCONF-ACK |
| 3482 | * Chunk exists. This will occur when an older ASCONF |
| 3483 | * arrives out of order. In such a case, the receiver |
| 3484 | * should skip the ASCONF Chunk and not include ASCONF-ACK |
| 3485 | * Chunk for that chunk. |
| 3486 | */ |
| 3487 | asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial); |
| 3488 | if (!asconf_ack) |
| 3489 | return SCTP_DISPOSITION_DISCARD; |
| 3490 | } else { |
| 3491 | /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since |
| 3492 | * it must be either a stale packet or from an attacker. |
| 3493 | */ |
| 3494 | return SCTP_DISPOSITION_DISCARD; |
| 3495 | } |
| 3496 | |
| 3497 | /* ADDIP 5.2 E6) The destination address of the SCTP packet |
| 3498 | * containing the ASCONF-ACK Chunks MUST be the source address of |
| 3499 | * the SCTP packet that held the ASCONF Chunks. |
| 3500 | * |
| 3501 | * To do this properly, we'll set the destination address of the chunk |
| 3502 | * and at the transmit time, will try look up the transport to use. |
| 3503 | * Since ASCONFs may be bundled, the correct transport may not be |
| 3504 | * created untill we process the entire packet, thus this workaround. |
| 3505 | */ |
| 3506 | asconf_ack->dest = chunk->source; |
| 3507 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack)); |
| 3508 | |
| 3509 | return SCTP_DISPOSITION_CONSUME; |
| 3510 | } |
| 3511 | |
| 3512 | /* |
| 3513 | * ADDIP Section 4.3 General rules for address manipulation |
| 3514 | * When building TLV parameters for the ASCONF Chunk that will add or |
| 3515 | * delete IP addresses the D0 to D13 rules should be applied: |
| 3516 | */ |
| 3517 | sctp_disposition_t sctp_sf_do_asconf_ack(const struct sctp_endpoint *ep, |
| 3518 | const struct sctp_association *asoc, |
| 3519 | const sctp_subtype_t type, void *arg, |
| 3520 | sctp_cmd_seq_t *commands) |
| 3521 | { |
| 3522 | struct sctp_chunk *asconf_ack = arg; |
| 3523 | struct sctp_chunk *last_asconf = asoc->addip_last_asconf; |
| 3524 | struct sctp_chunk *abort; |
| 3525 | struct sctp_paramhdr *err_param = NULL; |
| 3526 | sctp_addiphdr_t *addip_hdr; |
| 3527 | __u32 sent_serial, rcvd_serial; |
| 3528 | |
| 3529 | if (!sctp_vtag_verify(asconf_ack, asoc)) { |
| 3530 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
| 3531 | SCTP_NULL()); |
| 3532 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 3533 | } |
| 3534 | |
| 3535 | /* ADD-IP, Section 4.1.2: |
| 3536 | * This chunk MUST be sent in an authenticated way by using |
| 3537 | * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk |
| 3538 | * is received unauthenticated it MUST be silently discarded as |
| 3539 | * described in [I-D.ietf-tsvwg-sctp-auth]. |
| 3540 | */ |
| 3541 | if (!sctp_addip_noauth && !asconf_ack->auth) |
| 3542 | return sctp_sf_discard_chunk(ep, asoc, type, arg, commands); |
| 3543 | |
| 3544 | /* Make sure that the ADDIP chunk has a valid length. */ |
| 3545 | if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t))) |
| 3546 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 3547 | commands); |
| 3548 | |
| 3549 | addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data; |
| 3550 | rcvd_serial = ntohl(addip_hdr->serial); |
| 3551 | |
| 3552 | /* Verify the ASCONF-ACK chunk before processing it. */ |
| 3553 | if (!sctp_verify_asconf(asoc, |
| 3554 | (sctp_paramhdr_t *)addip_hdr->params, |
| 3555 | (void *)asconf_ack->chunk_end, |
| 3556 | &err_param)) |
| 3557 | return sctp_sf_violation_paramlen(ep, asoc, type, |
| 3558 | (void *)&err_param, commands); |
| 3559 | |
| 3560 | if (last_asconf) { |
| 3561 | addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr; |
| 3562 | sent_serial = ntohl(addip_hdr->serial); |
| 3563 | } else { |
| 3564 | sent_serial = asoc->addip_serial - 1; |
| 3565 | } |
| 3566 | |
| 3567 | /* D0) If an endpoint receives an ASCONF-ACK that is greater than or |
| 3568 | * equal to the next serial number to be used but no ASCONF chunk is |
| 3569 | * outstanding the endpoint MUST ABORT the association. Note that a |
| 3570 | * sequence number is greater than if it is no more than 2^^31-1 |
| 3571 | * larger than the current sequence number (using serial arithmetic). |
| 3572 | */ |
| 3573 | if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) && |
| 3574 | !(asoc->addip_last_asconf)) { |
| 3575 | abort = sctp_make_abort(asoc, asconf_ack, |
| 3576 | sizeof(sctp_errhdr_t)); |
| 3577 | if (abort) { |
| 3578 | sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0); |
| 3579 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
| 3580 | SCTP_CHUNK(abort)); |
| 3581 | } |
| 3582 | /* We are going to ABORT, so we might as well stop |
| 3583 | * processing the rest of the chunks in the packet. |
| 3584 | */ |
| 3585 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| 3586 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); |
| 3587 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL()); |
| 3588 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| 3589 | SCTP_ERROR(ECONNABORTED)); |
| 3590 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
| 3591 | SCTP_PERR(SCTP_ERROR_ASCONF_ACK)); |
| 3592 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
| 3593 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); |
| 3594 | return SCTP_DISPOSITION_ABORT; |
| 3595 | } |
| 3596 | |
| 3597 | if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) { |
| 3598 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| 3599 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); |
| 3600 | |
| 3601 | if (!sctp_process_asconf_ack((struct sctp_association *)asoc, |
| 3602 | asconf_ack)) |
| 3603 | return SCTP_DISPOSITION_CONSUME; |
| 3604 | |
| 3605 | abort = sctp_make_abort(asoc, asconf_ack, |
| 3606 | sizeof(sctp_errhdr_t)); |
| 3607 | if (abort) { |
| 3608 | sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0); |
| 3609 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
| 3610 | SCTP_CHUNK(abort)); |
| 3611 | } |
| 3612 | /* We are going to ABORT, so we might as well stop |
| 3613 | * processing the rest of the chunks in the packet. |
| 3614 | */ |
| 3615 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL()); |
| 3616 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| 3617 | SCTP_ERROR(ECONNABORTED)); |
| 3618 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
| 3619 | SCTP_PERR(SCTP_ERROR_ASCONF_ACK)); |
| 3620 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
| 3621 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); |
| 3622 | return SCTP_DISPOSITION_ABORT; |
| 3623 | } |
| 3624 | |
| 3625 | return SCTP_DISPOSITION_DISCARD; |
| 3626 | } |
| 3627 | |
| 3628 | /* |
| 3629 | * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP |
| 3630 | * |
| 3631 | * When a FORWARD TSN chunk arrives, the data receiver MUST first update |
| 3632 | * its cumulative TSN point to the value carried in the FORWARD TSN |
| 3633 | * chunk, and then MUST further advance its cumulative TSN point locally |
| 3634 | * if possible. |
| 3635 | * After the above processing, the data receiver MUST stop reporting any |
| 3636 | * missing TSNs earlier than or equal to the new cumulative TSN point. |
| 3637 | * |
| 3638 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
| 3639 | * |
| 3640 | * The return value is the disposition of the chunk. |
| 3641 | */ |
| 3642 | sctp_disposition_t sctp_sf_eat_fwd_tsn(const struct sctp_endpoint *ep, |
| 3643 | const struct sctp_association *asoc, |
| 3644 | const sctp_subtype_t type, |
| 3645 | void *arg, |
| 3646 | sctp_cmd_seq_t *commands) |
| 3647 | { |
| 3648 | struct sctp_chunk *chunk = arg; |
| 3649 | struct sctp_fwdtsn_hdr *fwdtsn_hdr; |
| 3650 | __u16 len; |
| 3651 | __u32 tsn; |
| 3652 | |
| 3653 | if (!sctp_vtag_verify(chunk, asoc)) { |
| 3654 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
| 3655 | SCTP_NULL()); |
| 3656 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 3657 | } |
| 3658 | |
| 3659 | /* Make sure that the FORWARD_TSN chunk has valid length. */ |
| 3660 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk))) |
| 3661 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 3662 | commands); |
| 3663 | |
| 3664 | fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data; |
| 3665 | chunk->subh.fwdtsn_hdr = fwdtsn_hdr; |
| 3666 | len = ntohs(chunk->chunk_hdr->length); |
| 3667 | len -= sizeof(struct sctp_chunkhdr); |
| 3668 | skb_pull(chunk->skb, len); |
| 3669 | |
| 3670 | tsn = ntohl(fwdtsn_hdr->new_cum_tsn); |
| 3671 | SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__, tsn); |
| 3672 | |
| 3673 | /* The TSN is too high--silently discard the chunk and count on it |
| 3674 | * getting retransmitted later. |
| 3675 | */ |
| 3676 | if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0) |
| 3677 | goto discard_noforce; |
| 3678 | |
| 3679 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn)); |
| 3680 | if (len > sizeof(struct sctp_fwdtsn_hdr)) |
| 3681 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN, |
| 3682 | SCTP_CHUNK(chunk)); |
| 3683 | |
| 3684 | /* Count this as receiving DATA. */ |
| 3685 | if (asoc->autoclose) { |
| 3686 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
| 3687 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
| 3688 | } |
| 3689 | |
| 3690 | /* FIXME: For now send a SACK, but DATA processing may |
| 3691 | * send another. |
| 3692 | */ |
| 3693 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE()); |
| 3694 | |
| 3695 | return SCTP_DISPOSITION_CONSUME; |
| 3696 | |
| 3697 | discard_noforce: |
| 3698 | return SCTP_DISPOSITION_DISCARD; |
| 3699 | } |
| 3700 | |
| 3701 | sctp_disposition_t sctp_sf_eat_fwd_tsn_fast( |
| 3702 | const struct sctp_endpoint *ep, |
| 3703 | const struct sctp_association *asoc, |
| 3704 | const sctp_subtype_t type, |
| 3705 | void *arg, |
| 3706 | sctp_cmd_seq_t *commands) |
| 3707 | { |
| 3708 | struct sctp_chunk *chunk = arg; |
| 3709 | struct sctp_fwdtsn_hdr *fwdtsn_hdr; |
| 3710 | __u16 len; |
| 3711 | __u32 tsn; |
| 3712 | |
| 3713 | if (!sctp_vtag_verify(chunk, asoc)) { |
| 3714 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
| 3715 | SCTP_NULL()); |
| 3716 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 3717 | } |
| 3718 | |
| 3719 | /* Make sure that the FORWARD_TSN chunk has a valid length. */ |
| 3720 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk))) |
| 3721 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 3722 | commands); |
| 3723 | |
| 3724 | fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data; |
| 3725 | chunk->subh.fwdtsn_hdr = fwdtsn_hdr; |
| 3726 | len = ntohs(chunk->chunk_hdr->length); |
| 3727 | len -= sizeof(struct sctp_chunkhdr); |
| 3728 | skb_pull(chunk->skb, len); |
| 3729 | |
| 3730 | tsn = ntohl(fwdtsn_hdr->new_cum_tsn); |
| 3731 | SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__, tsn); |
| 3732 | |
| 3733 | /* The TSN is too high--silently discard the chunk and count on it |
| 3734 | * getting retransmitted later. |
| 3735 | */ |
| 3736 | if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0) |
| 3737 | goto gen_shutdown; |
| 3738 | |
| 3739 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn)); |
| 3740 | if (len > sizeof(struct sctp_fwdtsn_hdr)) |
| 3741 | sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN, |
| 3742 | SCTP_CHUNK(chunk)); |
| 3743 | |
| 3744 | /* Go a head and force a SACK, since we are shutting down. */ |
| 3745 | gen_shutdown: |
| 3746 | /* Implementor's Guide. |
| 3747 | * |
| 3748 | * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately |
| 3749 | * respond to each received packet containing one or more DATA chunk(s) |
| 3750 | * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer |
| 3751 | */ |
| 3752 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL()); |
| 3753 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); |
| 3754 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
| 3755 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
| 3756 | |
| 3757 | return SCTP_DISPOSITION_CONSUME; |
| 3758 | } |
| 3759 | |
| 3760 | /* |
| 3761 | * SCTP-AUTH Section 6.3 Receving authenticated chukns |
| 3762 | * |
| 3763 | * The receiver MUST use the HMAC algorithm indicated in the HMAC |
| 3764 | * Identifier field. If this algorithm was not specified by the |
| 3765 | * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk |
| 3766 | * during association setup, the AUTH chunk and all chunks after it MUST |
| 3767 | * be discarded and an ERROR chunk SHOULD be sent with the error cause |
| 3768 | * defined in Section 4.1. |
| 3769 | * |
| 3770 | * If an endpoint with no shared key receives a Shared Key Identifier |
| 3771 | * other than 0, it MUST silently discard all authenticated chunks. If |
| 3772 | * the endpoint has at least one endpoint pair shared key for the peer, |
| 3773 | * it MUST use the key specified by the Shared Key Identifier if a |
| 3774 | * key has been configured for that Shared Key Identifier. If no |
| 3775 | * endpoint pair shared key has been configured for that Shared Key |
| 3776 | * Identifier, all authenticated chunks MUST be silently discarded. |
| 3777 | * |
| 3778 | * Verification Tag: 8.5 Verification Tag [Normal verification] |
| 3779 | * |
| 3780 | * The return value is the disposition of the chunk. |
| 3781 | */ |
| 3782 | static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep, |
| 3783 | const struct sctp_association *asoc, |
| 3784 | const sctp_subtype_t type, |
| 3785 | struct sctp_chunk *chunk) |
| 3786 | { |
| 3787 | struct sctp_authhdr *auth_hdr; |
| 3788 | struct sctp_hmac *hmac; |
| 3789 | unsigned int sig_len; |
| 3790 | __u16 key_id; |
| 3791 | __u8 *save_digest; |
| 3792 | __u8 *digest; |
| 3793 | |
| 3794 | /* Pull in the auth header, so we can do some more verification */ |
| 3795 | auth_hdr = (struct sctp_authhdr *)chunk->skb->data; |
| 3796 | chunk->subh.auth_hdr = auth_hdr; |
| 3797 | skb_pull(chunk->skb, sizeof(struct sctp_authhdr)); |
| 3798 | |
| 3799 | /* Make sure that we suport the HMAC algorithm from the auth |
| 3800 | * chunk. |
| 3801 | */ |
| 3802 | if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id)) |
| 3803 | return SCTP_IERROR_AUTH_BAD_HMAC; |
| 3804 | |
| 3805 | /* Make sure that the provided shared key identifier has been |
| 3806 | * configured |
| 3807 | */ |
| 3808 | key_id = ntohs(auth_hdr->shkey_id); |
| 3809 | if (key_id != asoc->active_key_id && !sctp_auth_get_shkey(asoc, key_id)) |
| 3810 | return SCTP_IERROR_AUTH_BAD_KEYID; |
| 3811 | |
| 3812 | |
| 3813 | /* Make sure that the length of the signature matches what |
| 3814 | * we expect. |
| 3815 | */ |
| 3816 | sig_len = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_auth_chunk_t); |
| 3817 | hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id)); |
| 3818 | if (sig_len != hmac->hmac_len) |
| 3819 | return SCTP_IERROR_PROTO_VIOLATION; |
| 3820 | |
| 3821 | /* Now that we've done validation checks, we can compute and |
| 3822 | * verify the hmac. The steps involved are: |
| 3823 | * 1. Save the digest from the chunk. |
| 3824 | * 2. Zero out the digest in the chunk. |
| 3825 | * 3. Compute the new digest |
| 3826 | * 4. Compare saved and new digests. |
| 3827 | */ |
| 3828 | digest = auth_hdr->hmac; |
| 3829 | skb_pull(chunk->skb, sig_len); |
| 3830 | |
| 3831 | save_digest = kmemdup(digest, sig_len, GFP_ATOMIC); |
| 3832 | if (!save_digest) |
| 3833 | goto nomem; |
| 3834 | |
| 3835 | memset(digest, 0, sig_len); |
| 3836 | |
| 3837 | sctp_auth_calculate_hmac(asoc, chunk->skb, |
| 3838 | (struct sctp_auth_chunk *)chunk->chunk_hdr, |
| 3839 | GFP_ATOMIC); |
| 3840 | |
| 3841 | /* Discard the packet if the digests do not match */ |
| 3842 | if (memcmp(save_digest, digest, sig_len)) { |
| 3843 | kfree(save_digest); |
| 3844 | return SCTP_IERROR_BAD_SIG; |
| 3845 | } |
| 3846 | |
| 3847 | kfree(save_digest); |
| 3848 | chunk->auth = 1; |
| 3849 | |
| 3850 | return SCTP_IERROR_NO_ERROR; |
| 3851 | nomem: |
| 3852 | return SCTP_IERROR_NOMEM; |
| 3853 | } |
| 3854 | |
| 3855 | sctp_disposition_t sctp_sf_eat_auth(const struct sctp_endpoint *ep, |
| 3856 | const struct sctp_association *asoc, |
| 3857 | const sctp_subtype_t type, |
| 3858 | void *arg, |
| 3859 | sctp_cmd_seq_t *commands) |
| 3860 | { |
| 3861 | struct sctp_authhdr *auth_hdr; |
| 3862 | struct sctp_chunk *chunk = arg; |
| 3863 | struct sctp_chunk *err_chunk; |
| 3864 | sctp_ierror_t error; |
| 3865 | |
| 3866 | /* Make sure that the peer has AUTH capable */ |
| 3867 | if (!asoc->peer.auth_capable) |
| 3868 | return sctp_sf_unk_chunk(ep, asoc, type, arg, commands); |
| 3869 | |
| 3870 | if (!sctp_vtag_verify(chunk, asoc)) { |
| 3871 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG, |
| 3872 | SCTP_NULL()); |
| 3873 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 3874 | } |
| 3875 | |
| 3876 | /* Make sure that the AUTH chunk has valid length. */ |
| 3877 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk))) |
| 3878 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 3879 | commands); |
| 3880 | |
| 3881 | auth_hdr = (struct sctp_authhdr *)chunk->skb->data; |
| 3882 | error = sctp_sf_authenticate(ep, asoc, type, chunk); |
| 3883 | switch (error) { |
| 3884 | case SCTP_IERROR_AUTH_BAD_HMAC: |
| 3885 | /* Generate the ERROR chunk and discard the rest |
| 3886 | * of the packet |
| 3887 | */ |
| 3888 | err_chunk = sctp_make_op_error(asoc, chunk, |
| 3889 | SCTP_ERROR_UNSUP_HMAC, |
| 3890 | &auth_hdr->hmac_id, |
| 3891 | sizeof(__u16)); |
| 3892 | if (err_chunk) { |
| 3893 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
| 3894 | SCTP_CHUNK(err_chunk)); |
| 3895 | } |
| 3896 | /* Fall Through */ |
| 3897 | case SCTP_IERROR_AUTH_BAD_KEYID: |
| 3898 | case SCTP_IERROR_BAD_SIG: |
| 3899 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 3900 | break; |
| 3901 | case SCTP_IERROR_PROTO_VIOLATION: |
| 3902 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 3903 | commands); |
| 3904 | break; |
| 3905 | case SCTP_IERROR_NOMEM: |
| 3906 | return SCTP_DISPOSITION_NOMEM; |
| 3907 | default: |
| 3908 | break; |
| 3909 | } |
| 3910 | |
| 3911 | if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) { |
| 3912 | struct sctp_ulpevent *ev; |
| 3913 | |
| 3914 | ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id), |
| 3915 | SCTP_AUTH_NEWKEY, GFP_ATOMIC); |
| 3916 | |
| 3917 | if (!ev) |
| 3918 | return -ENOMEM; |
| 3919 | |
| 3920 | sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, |
| 3921 | SCTP_ULPEVENT(ev)); |
| 3922 | } |
| 3923 | |
| 3924 | return SCTP_DISPOSITION_CONSUME; |
| 3925 | } |
| 3926 | |
| 3927 | /* |
| 3928 | * Process an unknown chunk. |
| 3929 | * |
| 3930 | * Section: 3.2. Also, 2.1 in the implementor's guide. |
| 3931 | * |
| 3932 | * Chunk Types are encoded such that the highest-order two bits specify |
| 3933 | * the action that must be taken if the processing endpoint does not |
| 3934 | * recognize the Chunk Type. |
| 3935 | * |
| 3936 | * 00 - Stop processing this SCTP packet and discard it, do not process |
| 3937 | * any further chunks within it. |
| 3938 | * |
| 3939 | * 01 - Stop processing this SCTP packet and discard it, do not process |
| 3940 | * any further chunks within it, and report the unrecognized |
| 3941 | * chunk in an 'Unrecognized Chunk Type'. |
| 3942 | * |
| 3943 | * 10 - Skip this chunk and continue processing. |
| 3944 | * |
| 3945 | * 11 - Skip this chunk and continue processing, but report in an ERROR |
| 3946 | * Chunk using the 'Unrecognized Chunk Type' cause of error. |
| 3947 | * |
| 3948 | * The return value is the disposition of the chunk. |
| 3949 | */ |
| 3950 | sctp_disposition_t sctp_sf_unk_chunk(const struct sctp_endpoint *ep, |
| 3951 | const struct sctp_association *asoc, |
| 3952 | const sctp_subtype_t type, |
| 3953 | void *arg, |
| 3954 | sctp_cmd_seq_t *commands) |
| 3955 | { |
| 3956 | struct sctp_chunk *unk_chunk = arg; |
| 3957 | struct sctp_chunk *err_chunk; |
| 3958 | sctp_chunkhdr_t *hdr; |
| 3959 | |
| 3960 | SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type.chunk); |
| 3961 | |
| 3962 | if (!sctp_vtag_verify(unk_chunk, asoc)) |
| 3963 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 3964 | |
| 3965 | /* Make sure that the chunk has a valid length. |
| 3966 | * Since we don't know the chunk type, we use a general |
| 3967 | * chunkhdr structure to make a comparison. |
| 3968 | */ |
| 3969 | if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t))) |
| 3970 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 3971 | commands); |
| 3972 | |
| 3973 | switch (type.chunk & SCTP_CID_ACTION_MASK) { |
| 3974 | case SCTP_CID_ACTION_DISCARD: |
| 3975 | /* Discard the packet. */ |
| 3976 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 3977 | break; |
| 3978 | case SCTP_CID_ACTION_DISCARD_ERR: |
| 3979 | /* Discard the packet. */ |
| 3980 | sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 3981 | |
| 3982 | /* Generate an ERROR chunk as response. */ |
| 3983 | hdr = unk_chunk->chunk_hdr; |
| 3984 | err_chunk = sctp_make_op_error(asoc, unk_chunk, |
| 3985 | SCTP_ERROR_UNKNOWN_CHUNK, hdr, |
| 3986 | WORD_ROUND(ntohs(hdr->length))); |
| 3987 | if (err_chunk) { |
| 3988 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
| 3989 | SCTP_CHUNK(err_chunk)); |
| 3990 | } |
| 3991 | return SCTP_DISPOSITION_CONSUME; |
| 3992 | break; |
| 3993 | case SCTP_CID_ACTION_SKIP: |
| 3994 | /* Skip the chunk. */ |
| 3995 | return SCTP_DISPOSITION_DISCARD; |
| 3996 | break; |
| 3997 | case SCTP_CID_ACTION_SKIP_ERR: |
| 3998 | /* Generate an ERROR chunk as response. */ |
| 3999 | hdr = unk_chunk->chunk_hdr; |
| 4000 | err_chunk = sctp_make_op_error(asoc, unk_chunk, |
| 4001 | SCTP_ERROR_UNKNOWN_CHUNK, hdr, |
| 4002 | WORD_ROUND(ntohs(hdr->length))); |
| 4003 | if (err_chunk) { |
| 4004 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
| 4005 | SCTP_CHUNK(err_chunk)); |
| 4006 | } |
| 4007 | /* Skip the chunk. */ |
| 4008 | return SCTP_DISPOSITION_CONSUME; |
| 4009 | break; |
| 4010 | default: |
| 4011 | break; |
| 4012 | } |
| 4013 | |
| 4014 | return SCTP_DISPOSITION_DISCARD; |
| 4015 | } |
| 4016 | |
| 4017 | /* |
| 4018 | * Discard the chunk. |
| 4019 | * |
| 4020 | * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2 |
| 4021 | * [Too numerous to mention...] |
| 4022 | * Verification Tag: No verification needed. |
| 4023 | * Inputs |
| 4024 | * (endpoint, asoc, chunk) |
| 4025 | * |
| 4026 | * Outputs |
| 4027 | * (asoc, reply_msg, msg_up, timers, counters) |
| 4028 | * |
| 4029 | * The return value is the disposition of the chunk. |
| 4030 | */ |
| 4031 | sctp_disposition_t sctp_sf_discard_chunk(const struct sctp_endpoint *ep, |
| 4032 | const struct sctp_association *asoc, |
| 4033 | const sctp_subtype_t type, |
| 4034 | void *arg, |
| 4035 | sctp_cmd_seq_t *commands) |
| 4036 | { |
| 4037 | struct sctp_chunk *chunk = arg; |
| 4038 | |
| 4039 | /* Make sure that the chunk has a valid length. |
| 4040 | * Since we don't know the chunk type, we use a general |
| 4041 | * chunkhdr structure to make a comparison. |
| 4042 | */ |
| 4043 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
| 4044 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 4045 | commands); |
| 4046 | |
| 4047 | SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type.chunk); |
| 4048 | return SCTP_DISPOSITION_DISCARD; |
| 4049 | } |
| 4050 | |
| 4051 | /* |
| 4052 | * Discard the whole packet. |
| 4053 | * |
| 4054 | * Section: 8.4 2) |
| 4055 | * |
| 4056 | * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST |
| 4057 | * silently discard the OOTB packet and take no further action. |
| 4058 | * |
| 4059 | * Verification Tag: No verification necessary |
| 4060 | * |
| 4061 | * Inputs |
| 4062 | * (endpoint, asoc, chunk) |
| 4063 | * |
| 4064 | * Outputs |
| 4065 | * (asoc, reply_msg, msg_up, timers, counters) |
| 4066 | * |
| 4067 | * The return value is the disposition of the chunk. |
| 4068 | */ |
| 4069 | sctp_disposition_t sctp_sf_pdiscard(const struct sctp_endpoint *ep, |
| 4070 | const struct sctp_association *asoc, |
| 4071 | const sctp_subtype_t type, |
| 4072 | void *arg, |
| 4073 | sctp_cmd_seq_t *commands) |
| 4074 | { |
| 4075 | SCTP_INC_STATS(SCTP_MIB_IN_PKT_DISCARDS); |
| 4076 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL()); |
| 4077 | |
| 4078 | return SCTP_DISPOSITION_CONSUME; |
| 4079 | } |
| 4080 | |
| 4081 | |
| 4082 | /* |
| 4083 | * The other end is violating protocol. |
| 4084 | * |
| 4085 | * Section: Not specified |
| 4086 | * Verification Tag: Not specified |
| 4087 | * Inputs |
| 4088 | * (endpoint, asoc, chunk) |
| 4089 | * |
| 4090 | * Outputs |
| 4091 | * (asoc, reply_msg, msg_up, timers, counters) |
| 4092 | * |
| 4093 | * We simply tag the chunk as a violation. The state machine will log |
| 4094 | * the violation and continue. |
| 4095 | */ |
| 4096 | sctp_disposition_t sctp_sf_violation(const struct sctp_endpoint *ep, |
| 4097 | const struct sctp_association *asoc, |
| 4098 | const sctp_subtype_t type, |
| 4099 | void *arg, |
| 4100 | sctp_cmd_seq_t *commands) |
| 4101 | { |
| 4102 | struct sctp_chunk *chunk = arg; |
| 4103 | |
| 4104 | /* Make sure that the chunk has a valid length. */ |
| 4105 | if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t))) |
| 4106 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 4107 | commands); |
| 4108 | |
| 4109 | return SCTP_DISPOSITION_VIOLATION; |
| 4110 | } |
| 4111 | |
| 4112 | /* |
| 4113 | * Common function to handle a protocol violation. |
| 4114 | */ |
| 4115 | static sctp_disposition_t sctp_sf_abort_violation( |
| 4116 | const struct sctp_endpoint *ep, |
| 4117 | const struct sctp_association *asoc, |
| 4118 | void *arg, |
| 4119 | sctp_cmd_seq_t *commands, |
| 4120 | const __u8 *payload, |
| 4121 | const size_t paylen) |
| 4122 | { |
| 4123 | struct sctp_packet *packet = NULL; |
| 4124 | struct sctp_chunk *chunk = arg; |
| 4125 | struct sctp_chunk *abort = NULL; |
| 4126 | |
| 4127 | /* SCTP-AUTH, Section 6.3: |
| 4128 | * It should be noted that if the receiver wants to tear |
| 4129 | * down an association in an authenticated way only, the |
| 4130 | * handling of malformed packets should not result in |
| 4131 | * tearing down the association. |
| 4132 | * |
| 4133 | * This means that if we only want to abort associations |
| 4134 | * in an authenticated way (i.e AUTH+ABORT), then we |
| 4135 | * can't destroy this association just becuase the packet |
| 4136 | * was malformed. |
| 4137 | */ |
| 4138 | if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc)) |
| 4139 | goto discard; |
| 4140 | |
| 4141 | /* Make the abort chunk. */ |
| 4142 | abort = sctp_make_abort_violation(asoc, chunk, payload, paylen); |
| 4143 | if (!abort) |
| 4144 | goto nomem; |
| 4145 | |
| 4146 | if (asoc) { |
| 4147 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); |
| 4148 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
| 4149 | |
| 4150 | if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) { |
| 4151 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| 4152 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
| 4153 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| 4154 | SCTP_ERROR(ECONNREFUSED)); |
| 4155 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, |
| 4156 | SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION)); |
| 4157 | } else { |
| 4158 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| 4159 | SCTP_ERROR(ECONNABORTED)); |
| 4160 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
| 4161 | SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION)); |
| 4162 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); |
| 4163 | } |
| 4164 | } else { |
| 4165 | packet = sctp_ootb_pkt_new(asoc, chunk); |
| 4166 | |
| 4167 | if (!packet) |
| 4168 | goto nomem_pkt; |
| 4169 | |
| 4170 | if (sctp_test_T_bit(abort)) |
| 4171 | packet->vtag = ntohl(chunk->sctp_hdr->vtag); |
| 4172 | |
| 4173 | abort->skb->sk = ep->base.sk; |
| 4174 | |
| 4175 | sctp_packet_append_chunk(packet, abort); |
| 4176 | |
| 4177 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
| 4178 | SCTP_PACKET(packet)); |
| 4179 | |
| 4180 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
| 4181 | } |
| 4182 | |
| 4183 | discard: |
| 4184 | sctp_sf_pdiscard(ep, asoc, SCTP_ST_CHUNK(0), arg, commands); |
| 4185 | |
| 4186 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
| 4187 | |
| 4188 | return SCTP_DISPOSITION_ABORT; |
| 4189 | |
| 4190 | nomem_pkt: |
| 4191 | sctp_chunk_free(abort); |
| 4192 | nomem: |
| 4193 | return SCTP_DISPOSITION_NOMEM; |
| 4194 | } |
| 4195 | |
| 4196 | /* |
| 4197 | * Handle a protocol violation when the chunk length is invalid. |
| 4198 | * "Invalid" length is identified as smaller then the minimal length a |
| 4199 | * given chunk can be. For example, a SACK chunk has invalid length |
| 4200 | * if it's length is set to be smaller then the size of sctp_sack_chunk_t. |
| 4201 | * |
| 4202 | * We inform the other end by sending an ABORT with a Protocol Violation |
| 4203 | * error code. |
| 4204 | * |
| 4205 | * Section: Not specified |
| 4206 | * Verification Tag: Nothing to do |
| 4207 | * Inputs |
| 4208 | * (endpoint, asoc, chunk) |
| 4209 | * |
| 4210 | * Outputs |
| 4211 | * (reply_msg, msg_up, counters) |
| 4212 | * |
| 4213 | * Generate an ABORT chunk and terminate the association. |
| 4214 | */ |
| 4215 | static sctp_disposition_t sctp_sf_violation_chunklen( |
| 4216 | const struct sctp_endpoint *ep, |
| 4217 | const struct sctp_association *asoc, |
| 4218 | const sctp_subtype_t type, |
| 4219 | void *arg, |
| 4220 | sctp_cmd_seq_t *commands) |
| 4221 | { |
| 4222 | char err_str[]="The following chunk had invalid length:"; |
| 4223 | |
| 4224 | return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str, |
| 4225 | sizeof(err_str)); |
| 4226 | } |
| 4227 | |
| 4228 | /* |
| 4229 | * Handle a protocol violation when the parameter length is invalid. |
| 4230 | * "Invalid" length is identified as smaller then the minimal length a |
| 4231 | * given parameter can be. |
| 4232 | */ |
| 4233 | static sctp_disposition_t sctp_sf_violation_paramlen( |
| 4234 | const struct sctp_endpoint *ep, |
| 4235 | const struct sctp_association *asoc, |
| 4236 | const sctp_subtype_t type, |
| 4237 | void *arg, |
| 4238 | sctp_cmd_seq_t *commands) { |
| 4239 | char err_str[] = "The following parameter had invalid length:"; |
| 4240 | |
| 4241 | return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str, |
| 4242 | sizeof(err_str)); |
| 4243 | } |
| 4244 | |
| 4245 | /* Handle a protocol violation when the peer trying to advance the |
| 4246 | * cumulative tsn ack to a point beyond the max tsn currently sent. |
| 4247 | * |
| 4248 | * We inform the other end by sending an ABORT with a Protocol Violation |
| 4249 | * error code. |
| 4250 | */ |
| 4251 | static sctp_disposition_t sctp_sf_violation_ctsn( |
| 4252 | const struct sctp_endpoint *ep, |
| 4253 | const struct sctp_association *asoc, |
| 4254 | const sctp_subtype_t type, |
| 4255 | void *arg, |
| 4256 | sctp_cmd_seq_t *commands) |
| 4257 | { |
| 4258 | char err_str[]="The cumulative tsn ack beyond the max tsn currently sent:"; |
| 4259 | |
| 4260 | return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str, |
| 4261 | sizeof(err_str)); |
| 4262 | } |
| 4263 | |
| 4264 | /* Handle protocol violation of an invalid chunk bundling. For example, |
| 4265 | * when we have an association and we recieve bundled INIT-ACK, or |
| 4266 | * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle" |
| 4267 | * statement from the specs. Additinally, there might be an attacker |
| 4268 | * on the path and we may not want to continue this communication. |
| 4269 | */ |
| 4270 | static sctp_disposition_t sctp_sf_violation_chunk( |
| 4271 | const struct sctp_endpoint *ep, |
| 4272 | const struct sctp_association *asoc, |
| 4273 | const sctp_subtype_t type, |
| 4274 | void *arg, |
| 4275 | sctp_cmd_seq_t *commands) |
| 4276 | { |
| 4277 | char err_str[]="The following chunk violates protocol:"; |
| 4278 | |
| 4279 | if (!asoc) |
| 4280 | return sctp_sf_violation(ep, asoc, type, arg, commands); |
| 4281 | |
| 4282 | return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str, |
| 4283 | sizeof(err_str)); |
| 4284 | } |
| 4285 | /*************************************************************************** |
| 4286 | * These are the state functions for handling primitive (Section 10) events. |
| 4287 | ***************************************************************************/ |
| 4288 | /* |
| 4289 | * sctp_sf_do_prm_asoc |
| 4290 | * |
| 4291 | * Section: 10.1 ULP-to-SCTP |
| 4292 | * B) Associate |
| 4293 | * |
| 4294 | * Format: ASSOCIATE(local SCTP instance name, destination transport addr, |
| 4295 | * outbound stream count) |
| 4296 | * -> association id [,destination transport addr list] [,outbound stream |
| 4297 | * count] |
| 4298 | * |
| 4299 | * This primitive allows the upper layer to initiate an association to a |
| 4300 | * specific peer endpoint. |
| 4301 | * |
| 4302 | * The peer endpoint shall be specified by one of the transport addresses |
| 4303 | * which defines the endpoint (see Section 1.4). If the local SCTP |
| 4304 | * instance has not been initialized, the ASSOCIATE is considered an |
| 4305 | * error. |
| 4306 | * [This is not relevant for the kernel implementation since we do all |
| 4307 | * initialization at boot time. It we hadn't initialized we wouldn't |
| 4308 | * get anywhere near this code.] |
| 4309 | * |
| 4310 | * An association id, which is a local handle to the SCTP association, |
| 4311 | * will be returned on successful establishment of the association. If |
| 4312 | * SCTP is not able to open an SCTP association with the peer endpoint, |
| 4313 | * an error is returned. |
| 4314 | * [In the kernel implementation, the struct sctp_association needs to |
| 4315 | * be created BEFORE causing this primitive to run.] |
| 4316 | * |
| 4317 | * Other association parameters may be returned, including the |
| 4318 | * complete destination transport addresses of the peer as well as the |
| 4319 | * outbound stream count of the local endpoint. One of the transport |
| 4320 | * address from the returned destination addresses will be selected by |
| 4321 | * the local endpoint as default primary path for sending SCTP packets |
| 4322 | * to this peer. The returned "destination transport addr list" can |
| 4323 | * be used by the ULP to change the default primary path or to force |
| 4324 | * sending a packet to a specific transport address. [All of this |
| 4325 | * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING |
| 4326 | * function.] |
| 4327 | * |
| 4328 | * Mandatory attributes: |
| 4329 | * |
| 4330 | * o local SCTP instance name - obtained from the INITIALIZE operation. |
| 4331 | * [This is the argument asoc.] |
| 4332 | * o destination transport addr - specified as one of the transport |
| 4333 | * addresses of the peer endpoint with which the association is to be |
| 4334 | * established. |
| 4335 | * [This is asoc->peer.active_path.] |
| 4336 | * o outbound stream count - the number of outbound streams the ULP |
| 4337 | * would like to open towards this peer endpoint. |
| 4338 | * [BUG: This is not currently implemented.] |
| 4339 | * Optional attributes: |
| 4340 | * |
| 4341 | * None. |
| 4342 | * |
| 4343 | * The return value is a disposition. |
| 4344 | */ |
| 4345 | sctp_disposition_t sctp_sf_do_prm_asoc(const struct sctp_endpoint *ep, |
| 4346 | const struct sctp_association *asoc, |
| 4347 | const sctp_subtype_t type, |
| 4348 | void *arg, |
| 4349 | sctp_cmd_seq_t *commands) |
| 4350 | { |
| 4351 | struct sctp_chunk *repl; |
| 4352 | |
| 4353 | /* The comment below says that we enter COOKIE-WAIT AFTER |
| 4354 | * sending the INIT, but that doesn't actually work in our |
| 4355 | * implementation... |
| 4356 | */ |
| 4357 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| 4358 | SCTP_STATE(SCTP_STATE_COOKIE_WAIT)); |
| 4359 | |
| 4360 | /* RFC 2960 5.1 Normal Establishment of an Association |
| 4361 | * |
| 4362 | * A) "A" first sends an INIT chunk to "Z". In the INIT, "A" |
| 4363 | * must provide its Verification Tag (Tag_A) in the Initiate |
| 4364 | * Tag field. Tag_A SHOULD be a random number in the range of |
| 4365 | * 1 to 4294967295 (see 5.3.1 for Tag value selection). ... |
| 4366 | */ |
| 4367 | |
| 4368 | repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0); |
| 4369 | if (!repl) |
| 4370 | goto nomem; |
| 4371 | |
| 4372 | /* Cast away the const modifier, as we want to just |
| 4373 | * rerun it through as a sideffect. |
| 4374 | */ |
| 4375 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, |
| 4376 | SCTP_ASOC((struct sctp_association *) asoc)); |
| 4377 | |
| 4378 | /* Choose transport for INIT. */ |
| 4379 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT, |
| 4380 | SCTP_CHUNK(repl)); |
| 4381 | |
| 4382 | /* After sending the INIT, "A" starts the T1-init timer and |
| 4383 | * enters the COOKIE-WAIT state. |
| 4384 | */ |
| 4385 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
| 4386 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
| 4387 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
| 4388 | return SCTP_DISPOSITION_CONSUME; |
| 4389 | |
| 4390 | nomem: |
| 4391 | return SCTP_DISPOSITION_NOMEM; |
| 4392 | } |
| 4393 | |
| 4394 | /* |
| 4395 | * Process the SEND primitive. |
| 4396 | * |
| 4397 | * Section: 10.1 ULP-to-SCTP |
| 4398 | * E) Send |
| 4399 | * |
| 4400 | * Format: SEND(association id, buffer address, byte count [,context] |
| 4401 | * [,stream id] [,life time] [,destination transport address] |
| 4402 | * [,unorder flag] [,no-bundle flag] [,payload protocol-id] ) |
| 4403 | * -> result |
| 4404 | * |
| 4405 | * This is the main method to send user data via SCTP. |
| 4406 | * |
| 4407 | * Mandatory attributes: |
| 4408 | * |
| 4409 | * o association id - local handle to the SCTP association |
| 4410 | * |
| 4411 | * o buffer address - the location where the user message to be |
| 4412 | * transmitted is stored; |
| 4413 | * |
| 4414 | * o byte count - The size of the user data in number of bytes; |
| 4415 | * |
| 4416 | * Optional attributes: |
| 4417 | * |
| 4418 | * o context - an optional 32 bit integer that will be carried in the |
| 4419 | * sending failure notification to the ULP if the transportation of |
| 4420 | * this User Message fails. |
| 4421 | * |
| 4422 | * o stream id - to indicate which stream to send the data on. If not |
| 4423 | * specified, stream 0 will be used. |
| 4424 | * |
| 4425 | * o life time - specifies the life time of the user data. The user data |
| 4426 | * will not be sent by SCTP after the life time expires. This |
| 4427 | * parameter can be used to avoid efforts to transmit stale |
| 4428 | * user messages. SCTP notifies the ULP if the data cannot be |
| 4429 | * initiated to transport (i.e. sent to the destination via SCTP's |
| 4430 | * send primitive) within the life time variable. However, the |
| 4431 | * user data will be transmitted if SCTP has attempted to transmit a |
| 4432 | * chunk before the life time expired. |
| 4433 | * |
| 4434 | * o destination transport address - specified as one of the destination |
| 4435 | * transport addresses of the peer endpoint to which this packet |
| 4436 | * should be sent. Whenever possible, SCTP should use this destination |
| 4437 | * transport address for sending the packets, instead of the current |
| 4438 | * primary path. |
| 4439 | * |
| 4440 | * o unorder flag - this flag, if present, indicates that the user |
| 4441 | * would like the data delivered in an unordered fashion to the peer |
| 4442 | * (i.e., the U flag is set to 1 on all DATA chunks carrying this |
| 4443 | * message). |
| 4444 | * |
| 4445 | * o no-bundle flag - instructs SCTP not to bundle this user data with |
| 4446 | * other outbound DATA chunks. SCTP MAY still bundle even when |
| 4447 | * this flag is present, when faced with network congestion. |
| 4448 | * |
| 4449 | * o payload protocol-id - A 32 bit unsigned integer that is to be |
| 4450 | * passed to the peer indicating the type of payload protocol data |
| 4451 | * being transmitted. This value is passed as opaque data by SCTP. |
| 4452 | * |
| 4453 | * The return value is the disposition. |
| 4454 | */ |
| 4455 | sctp_disposition_t sctp_sf_do_prm_send(const struct sctp_endpoint *ep, |
| 4456 | const struct sctp_association *asoc, |
| 4457 | const sctp_subtype_t type, |
| 4458 | void *arg, |
| 4459 | sctp_cmd_seq_t *commands) |
| 4460 | { |
| 4461 | struct sctp_chunk *chunk = arg; |
| 4462 | |
| 4463 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk)); |
| 4464 | return SCTP_DISPOSITION_CONSUME; |
| 4465 | } |
| 4466 | |
| 4467 | /* |
| 4468 | * Process the SHUTDOWN primitive. |
| 4469 | * |
| 4470 | * Section: 10.1: |
| 4471 | * C) Shutdown |
| 4472 | * |
| 4473 | * Format: SHUTDOWN(association id) |
| 4474 | * -> result |
| 4475 | * |
| 4476 | * Gracefully closes an association. Any locally queued user data |
| 4477 | * will be delivered to the peer. The association will be terminated only |
| 4478 | * after the peer acknowledges all the SCTP packets sent. A success code |
| 4479 | * will be returned on successful termination of the association. If |
| 4480 | * attempting to terminate the association results in a failure, an error |
| 4481 | * code shall be returned. |
| 4482 | * |
| 4483 | * Mandatory attributes: |
| 4484 | * |
| 4485 | * o association id - local handle to the SCTP association |
| 4486 | * |
| 4487 | * Optional attributes: |
| 4488 | * |
| 4489 | * None. |
| 4490 | * |
| 4491 | * The return value is the disposition. |
| 4492 | */ |
| 4493 | sctp_disposition_t sctp_sf_do_9_2_prm_shutdown( |
| 4494 | const struct sctp_endpoint *ep, |
| 4495 | const struct sctp_association *asoc, |
| 4496 | const sctp_subtype_t type, |
| 4497 | void *arg, |
| 4498 | sctp_cmd_seq_t *commands) |
| 4499 | { |
| 4500 | int disposition; |
| 4501 | |
| 4502 | /* From 9.2 Shutdown of an Association |
| 4503 | * Upon receipt of the SHUTDOWN primitive from its upper |
| 4504 | * layer, the endpoint enters SHUTDOWN-PENDING state and |
| 4505 | * remains there until all outstanding data has been |
| 4506 | * acknowledged by its peer. The endpoint accepts no new data |
| 4507 | * from its upper layer, but retransmits data to the far end |
| 4508 | * if necessary to fill gaps. |
| 4509 | */ |
| 4510 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| 4511 | SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING)); |
| 4512 | |
| 4513 | /* sctpimpguide-05 Section 2.12.2 |
| 4514 | * The sender of the SHUTDOWN MAY also start an overall guard timer |
| 4515 | * 'T5-shutdown-guard' to bound the overall time for shutdown sequence. |
| 4516 | */ |
| 4517 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
| 4518 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
| 4519 | |
| 4520 | disposition = SCTP_DISPOSITION_CONSUME; |
| 4521 | if (sctp_outq_is_empty(&asoc->outqueue)) { |
| 4522 | disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type, |
| 4523 | arg, commands); |
| 4524 | } |
| 4525 | return disposition; |
| 4526 | } |
| 4527 | |
| 4528 | /* |
| 4529 | * Process the ABORT primitive. |
| 4530 | * |
| 4531 | * Section: 10.1: |
| 4532 | * C) Abort |
| 4533 | * |
| 4534 | * Format: Abort(association id [, cause code]) |
| 4535 | * -> result |
| 4536 | * |
| 4537 | * Ungracefully closes an association. Any locally queued user data |
| 4538 | * will be discarded and an ABORT chunk is sent to the peer. A success code |
| 4539 | * will be returned on successful abortion of the association. If |
| 4540 | * attempting to abort the association results in a failure, an error |
| 4541 | * code shall be returned. |
| 4542 | * |
| 4543 | * Mandatory attributes: |
| 4544 | * |
| 4545 | * o association id - local handle to the SCTP association |
| 4546 | * |
| 4547 | * Optional attributes: |
| 4548 | * |
| 4549 | * o cause code - reason of the abort to be passed to the peer |
| 4550 | * |
| 4551 | * None. |
| 4552 | * |
| 4553 | * The return value is the disposition. |
| 4554 | */ |
| 4555 | sctp_disposition_t sctp_sf_do_9_1_prm_abort( |
| 4556 | const struct sctp_endpoint *ep, |
| 4557 | const struct sctp_association *asoc, |
| 4558 | const sctp_subtype_t type, |
| 4559 | void *arg, |
| 4560 | sctp_cmd_seq_t *commands) |
| 4561 | { |
| 4562 | /* From 9.1 Abort of an Association |
| 4563 | * Upon receipt of the ABORT primitive from its upper |
| 4564 | * layer, the endpoint enters CLOSED state and |
| 4565 | * discard all outstanding data has been |
| 4566 | * acknowledged by its peer. The endpoint accepts no new data |
| 4567 | * from its upper layer, but retransmits data to the far end |
| 4568 | * if necessary to fill gaps. |
| 4569 | */ |
| 4570 | struct sctp_chunk *abort = arg; |
| 4571 | sctp_disposition_t retval; |
| 4572 | |
| 4573 | retval = SCTP_DISPOSITION_CONSUME; |
| 4574 | |
| 4575 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); |
| 4576 | |
| 4577 | /* Even if we can't send the ABORT due to low memory delete the |
| 4578 | * TCB. This is a departure from our typical NOMEM handling. |
| 4579 | */ |
| 4580 | |
| 4581 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| 4582 | SCTP_ERROR(ECONNABORTED)); |
| 4583 | /* Delete the established association. */ |
| 4584 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
| 4585 | SCTP_PERR(SCTP_ERROR_USER_ABORT)); |
| 4586 | |
| 4587 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
| 4588 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); |
| 4589 | |
| 4590 | return retval; |
| 4591 | } |
| 4592 | |
| 4593 | /* We tried an illegal operation on an association which is closed. */ |
| 4594 | sctp_disposition_t sctp_sf_error_closed(const struct sctp_endpoint *ep, |
| 4595 | const struct sctp_association *asoc, |
| 4596 | const sctp_subtype_t type, |
| 4597 | void *arg, |
| 4598 | sctp_cmd_seq_t *commands) |
| 4599 | { |
| 4600 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL)); |
| 4601 | return SCTP_DISPOSITION_CONSUME; |
| 4602 | } |
| 4603 | |
| 4604 | /* We tried an illegal operation on an association which is shutting |
| 4605 | * down. |
| 4606 | */ |
| 4607 | sctp_disposition_t sctp_sf_error_shutdown(const struct sctp_endpoint *ep, |
| 4608 | const struct sctp_association *asoc, |
| 4609 | const sctp_subtype_t type, |
| 4610 | void *arg, |
| 4611 | sctp_cmd_seq_t *commands) |
| 4612 | { |
| 4613 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, |
| 4614 | SCTP_ERROR(-ESHUTDOWN)); |
| 4615 | return SCTP_DISPOSITION_CONSUME; |
| 4616 | } |
| 4617 | |
| 4618 | /* |
| 4619 | * sctp_cookie_wait_prm_shutdown |
| 4620 | * |
| 4621 | * Section: 4 Note: 2 |
| 4622 | * Verification Tag: |
| 4623 | * Inputs |
| 4624 | * (endpoint, asoc) |
| 4625 | * |
| 4626 | * The RFC does not explicitly address this issue, but is the route through the |
| 4627 | * state table when someone issues a shutdown while in COOKIE_WAIT state. |
| 4628 | * |
| 4629 | * Outputs |
| 4630 | * (timers) |
| 4631 | */ |
| 4632 | sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown( |
| 4633 | const struct sctp_endpoint *ep, |
| 4634 | const struct sctp_association *asoc, |
| 4635 | const sctp_subtype_t type, |
| 4636 | void *arg, |
| 4637 | sctp_cmd_seq_t *commands) |
| 4638 | { |
| 4639 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| 4640 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
| 4641 | |
| 4642 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| 4643 | SCTP_STATE(SCTP_STATE_CLOSED)); |
| 4644 | |
| 4645 | SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS); |
| 4646 | |
| 4647 | sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); |
| 4648 | |
| 4649 | return SCTP_DISPOSITION_DELETE_TCB; |
| 4650 | } |
| 4651 | |
| 4652 | /* |
| 4653 | * sctp_cookie_echoed_prm_shutdown |
| 4654 | * |
| 4655 | * Section: 4 Note: 2 |
| 4656 | * Verification Tag: |
| 4657 | * Inputs |
| 4658 | * (endpoint, asoc) |
| 4659 | * |
| 4660 | * The RFC does not explcitly address this issue, but is the route through the |
| 4661 | * state table when someone issues a shutdown while in COOKIE_ECHOED state. |
| 4662 | * |
| 4663 | * Outputs |
| 4664 | * (timers) |
| 4665 | */ |
| 4666 | sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown( |
| 4667 | const struct sctp_endpoint *ep, |
| 4668 | const struct sctp_association *asoc, |
| 4669 | const sctp_subtype_t type, |
| 4670 | void *arg, sctp_cmd_seq_t *commands) |
| 4671 | { |
| 4672 | /* There is a single T1 timer, so we should be able to use |
| 4673 | * common function with the COOKIE-WAIT state. |
| 4674 | */ |
| 4675 | return sctp_sf_cookie_wait_prm_shutdown(ep, asoc, type, arg, commands); |
| 4676 | } |
| 4677 | |
| 4678 | /* |
| 4679 | * sctp_sf_cookie_wait_prm_abort |
| 4680 | * |
| 4681 | * Section: 4 Note: 2 |
| 4682 | * Verification Tag: |
| 4683 | * Inputs |
| 4684 | * (endpoint, asoc) |
| 4685 | * |
| 4686 | * The RFC does not explicitly address this issue, but is the route through the |
| 4687 | * state table when someone issues an abort while in COOKIE_WAIT state. |
| 4688 | * |
| 4689 | * Outputs |
| 4690 | * (timers) |
| 4691 | */ |
| 4692 | sctp_disposition_t sctp_sf_cookie_wait_prm_abort( |
| 4693 | const struct sctp_endpoint *ep, |
| 4694 | const struct sctp_association *asoc, |
| 4695 | const sctp_subtype_t type, |
| 4696 | void *arg, |
| 4697 | sctp_cmd_seq_t *commands) |
| 4698 | { |
| 4699 | struct sctp_chunk *abort = arg; |
| 4700 | sctp_disposition_t retval; |
| 4701 | |
| 4702 | /* Stop T1-init timer */ |
| 4703 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| 4704 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
| 4705 | retval = SCTP_DISPOSITION_CONSUME; |
| 4706 | |
| 4707 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); |
| 4708 | |
| 4709 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| 4710 | SCTP_STATE(SCTP_STATE_CLOSED)); |
| 4711 | |
| 4712 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
| 4713 | |
| 4714 | /* Even if we can't send the ABORT due to low memory delete the |
| 4715 | * TCB. This is a departure from our typical NOMEM handling. |
| 4716 | */ |
| 4717 | |
| 4718 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| 4719 | SCTP_ERROR(ECONNREFUSED)); |
| 4720 | /* Delete the established association. */ |
| 4721 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, |
| 4722 | SCTP_PERR(SCTP_ERROR_USER_ABORT)); |
| 4723 | |
| 4724 | return retval; |
| 4725 | } |
| 4726 | |
| 4727 | /* |
| 4728 | * sctp_sf_cookie_echoed_prm_abort |
| 4729 | * |
| 4730 | * Section: 4 Note: 3 |
| 4731 | * Verification Tag: |
| 4732 | * Inputs |
| 4733 | * (endpoint, asoc) |
| 4734 | * |
| 4735 | * The RFC does not explcitly address this issue, but is the route through the |
| 4736 | * state table when someone issues an abort while in COOKIE_ECHOED state. |
| 4737 | * |
| 4738 | * Outputs |
| 4739 | * (timers) |
| 4740 | */ |
| 4741 | sctp_disposition_t sctp_sf_cookie_echoed_prm_abort( |
| 4742 | const struct sctp_endpoint *ep, |
| 4743 | const struct sctp_association *asoc, |
| 4744 | const sctp_subtype_t type, |
| 4745 | void *arg, |
| 4746 | sctp_cmd_seq_t *commands) |
| 4747 | { |
| 4748 | /* There is a single T1 timer, so we should be able to use |
| 4749 | * common function with the COOKIE-WAIT state. |
| 4750 | */ |
| 4751 | return sctp_sf_cookie_wait_prm_abort(ep, asoc, type, arg, commands); |
| 4752 | } |
| 4753 | |
| 4754 | /* |
| 4755 | * sctp_sf_shutdown_pending_prm_abort |
| 4756 | * |
| 4757 | * Inputs |
| 4758 | * (endpoint, asoc) |
| 4759 | * |
| 4760 | * The RFC does not explicitly address this issue, but is the route through the |
| 4761 | * state table when someone issues an abort while in SHUTDOWN-PENDING state. |
| 4762 | * |
| 4763 | * Outputs |
| 4764 | * (timers) |
| 4765 | */ |
| 4766 | sctp_disposition_t sctp_sf_shutdown_pending_prm_abort( |
| 4767 | const struct sctp_endpoint *ep, |
| 4768 | const struct sctp_association *asoc, |
| 4769 | const sctp_subtype_t type, |
| 4770 | void *arg, |
| 4771 | sctp_cmd_seq_t *commands) |
| 4772 | { |
| 4773 | /* Stop the T5-shutdown guard timer. */ |
| 4774 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| 4775 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
| 4776 | |
| 4777 | return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands); |
| 4778 | } |
| 4779 | |
| 4780 | /* |
| 4781 | * sctp_sf_shutdown_sent_prm_abort |
| 4782 | * |
| 4783 | * Inputs |
| 4784 | * (endpoint, asoc) |
| 4785 | * |
| 4786 | * The RFC does not explicitly address this issue, but is the route through the |
| 4787 | * state table when someone issues an abort while in SHUTDOWN-SENT state. |
| 4788 | * |
| 4789 | * Outputs |
| 4790 | * (timers) |
| 4791 | */ |
| 4792 | sctp_disposition_t sctp_sf_shutdown_sent_prm_abort( |
| 4793 | const struct sctp_endpoint *ep, |
| 4794 | const struct sctp_association *asoc, |
| 4795 | const sctp_subtype_t type, |
| 4796 | void *arg, |
| 4797 | sctp_cmd_seq_t *commands) |
| 4798 | { |
| 4799 | /* Stop the T2-shutdown timer. */ |
| 4800 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| 4801 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
| 4802 | |
| 4803 | /* Stop the T5-shutdown guard timer. */ |
| 4804 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| 4805 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
| 4806 | |
| 4807 | return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands); |
| 4808 | } |
| 4809 | |
| 4810 | /* |
| 4811 | * sctp_sf_cookie_echoed_prm_abort |
| 4812 | * |
| 4813 | * Inputs |
| 4814 | * (endpoint, asoc) |
| 4815 | * |
| 4816 | * The RFC does not explcitly address this issue, but is the route through the |
| 4817 | * state table when someone issues an abort while in COOKIE_ECHOED state. |
| 4818 | * |
| 4819 | * Outputs |
| 4820 | * (timers) |
| 4821 | */ |
| 4822 | sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort( |
| 4823 | const struct sctp_endpoint *ep, |
| 4824 | const struct sctp_association *asoc, |
| 4825 | const sctp_subtype_t type, |
| 4826 | void *arg, |
| 4827 | sctp_cmd_seq_t *commands) |
| 4828 | { |
| 4829 | /* The same T2 timer, so we should be able to use |
| 4830 | * common function with the SHUTDOWN-SENT state. |
| 4831 | */ |
| 4832 | return sctp_sf_shutdown_sent_prm_abort(ep, asoc, type, arg, commands); |
| 4833 | } |
| 4834 | |
| 4835 | /* |
| 4836 | * Process the REQUESTHEARTBEAT primitive |
| 4837 | * |
| 4838 | * 10.1 ULP-to-SCTP |
| 4839 | * J) Request Heartbeat |
| 4840 | * |
| 4841 | * Format: REQUESTHEARTBEAT(association id, destination transport address) |
| 4842 | * |
| 4843 | * -> result |
| 4844 | * |
| 4845 | * Instructs the local endpoint to perform a HeartBeat on the specified |
| 4846 | * destination transport address of the given association. The returned |
| 4847 | * result should indicate whether the transmission of the HEARTBEAT |
| 4848 | * chunk to the destination address is successful. |
| 4849 | * |
| 4850 | * Mandatory attributes: |
| 4851 | * |
| 4852 | * o association id - local handle to the SCTP association |
| 4853 | * |
| 4854 | * o destination transport address - the transport address of the |
| 4855 | * association on which a heartbeat should be issued. |
| 4856 | */ |
| 4857 | sctp_disposition_t sctp_sf_do_prm_requestheartbeat( |
| 4858 | const struct sctp_endpoint *ep, |
| 4859 | const struct sctp_association *asoc, |
| 4860 | const sctp_subtype_t type, |
| 4861 | void *arg, |
| 4862 | sctp_cmd_seq_t *commands) |
| 4863 | { |
| 4864 | if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type, |
| 4865 | (struct sctp_transport *)arg, commands)) |
| 4866 | return SCTP_DISPOSITION_NOMEM; |
| 4867 | |
| 4868 | /* |
| 4869 | * RFC 2960 (bis), section 8.3 |
| 4870 | * |
| 4871 | * D) Request an on-demand HEARTBEAT on a specific destination |
| 4872 | * transport address of a given association. |
| 4873 | * |
| 4874 | * The endpoint should increment the respective error counter of |
| 4875 | * the destination transport address each time a HEARTBEAT is sent |
| 4876 | * to that address and not acknowledged within one RTO. |
| 4877 | * |
| 4878 | */ |
| 4879 | sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_RESET, |
| 4880 | SCTP_TRANSPORT(arg)); |
| 4881 | return SCTP_DISPOSITION_CONSUME; |
| 4882 | } |
| 4883 | |
| 4884 | /* |
| 4885 | * ADDIP Section 4.1 ASCONF Chunk Procedures |
| 4886 | * When an endpoint has an ASCONF signaled change to be sent to the |
| 4887 | * remote endpoint it should do A1 to A9 |
| 4888 | */ |
| 4889 | sctp_disposition_t sctp_sf_do_prm_asconf(const struct sctp_endpoint *ep, |
| 4890 | const struct sctp_association *asoc, |
| 4891 | const sctp_subtype_t type, |
| 4892 | void *arg, |
| 4893 | sctp_cmd_seq_t *commands) |
| 4894 | { |
| 4895 | struct sctp_chunk *chunk = arg; |
| 4896 | |
| 4897 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk)); |
| 4898 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
| 4899 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); |
| 4900 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk)); |
| 4901 | return SCTP_DISPOSITION_CONSUME; |
| 4902 | } |
| 4903 | |
| 4904 | /* |
| 4905 | * Ignore the primitive event |
| 4906 | * |
| 4907 | * The return value is the disposition of the primitive. |
| 4908 | */ |
| 4909 | sctp_disposition_t sctp_sf_ignore_primitive( |
| 4910 | const struct sctp_endpoint *ep, |
| 4911 | const struct sctp_association *asoc, |
| 4912 | const sctp_subtype_t type, |
| 4913 | void *arg, |
| 4914 | sctp_cmd_seq_t *commands) |
| 4915 | { |
| 4916 | SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type.primitive); |
| 4917 | return SCTP_DISPOSITION_DISCARD; |
| 4918 | } |
| 4919 | |
| 4920 | /*************************************************************************** |
| 4921 | * These are the state functions for the OTHER events. |
| 4922 | ***************************************************************************/ |
| 4923 | |
| 4924 | /* |
| 4925 | * Start the shutdown negotiation. |
| 4926 | * |
| 4927 | * From Section 9.2: |
| 4928 | * Once all its outstanding data has been acknowledged, the endpoint |
| 4929 | * shall send a SHUTDOWN chunk to its peer including in the Cumulative |
| 4930 | * TSN Ack field the last sequential TSN it has received from the peer. |
| 4931 | * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT |
| 4932 | * state. If the timer expires, the endpoint must re-send the SHUTDOWN |
| 4933 | * with the updated last sequential TSN received from its peer. |
| 4934 | * |
| 4935 | * The return value is the disposition. |
| 4936 | */ |
| 4937 | sctp_disposition_t sctp_sf_do_9_2_start_shutdown( |
| 4938 | const struct sctp_endpoint *ep, |
| 4939 | const struct sctp_association *asoc, |
| 4940 | const sctp_subtype_t type, |
| 4941 | void *arg, |
| 4942 | sctp_cmd_seq_t *commands) |
| 4943 | { |
| 4944 | struct sctp_chunk *reply; |
| 4945 | |
| 4946 | /* Once all its outstanding data has been acknowledged, the |
| 4947 | * endpoint shall send a SHUTDOWN chunk to its peer including |
| 4948 | * in the Cumulative TSN Ack field the last sequential TSN it |
| 4949 | * has received from the peer. |
| 4950 | */ |
| 4951 | reply = sctp_make_shutdown(asoc, NULL); |
| 4952 | if (!reply) |
| 4953 | goto nomem; |
| 4954 | |
| 4955 | /* Set the transport for the SHUTDOWN chunk and the timeout for the |
| 4956 | * T2-shutdown timer. |
| 4957 | */ |
| 4958 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); |
| 4959 | |
| 4960 | /* It shall then start the T2-shutdown timer */ |
| 4961 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
| 4962 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
| 4963 | |
| 4964 | if (asoc->autoclose) |
| 4965 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| 4966 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
| 4967 | |
| 4968 | /* and enter the SHUTDOWN-SENT state. */ |
| 4969 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| 4970 | SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT)); |
| 4971 | |
| 4972 | /* sctp-implguide 2.10 Issues with Heartbeating and failover |
| 4973 | * |
| 4974 | * HEARTBEAT ... is discontinued after sending either SHUTDOWN |
| 4975 | * or SHUTDOWN-ACK. |
| 4976 | */ |
| 4977 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL()); |
| 4978 | |
| 4979 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
| 4980 | |
| 4981 | return SCTP_DISPOSITION_CONSUME; |
| 4982 | |
| 4983 | nomem: |
| 4984 | return SCTP_DISPOSITION_NOMEM; |
| 4985 | } |
| 4986 | |
| 4987 | /* |
| 4988 | * Generate a SHUTDOWN ACK now that everything is SACK'd. |
| 4989 | * |
| 4990 | * From Section 9.2: |
| 4991 | * |
| 4992 | * If it has no more outstanding DATA chunks, the SHUTDOWN receiver |
| 4993 | * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own, |
| 4994 | * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the |
| 4995 | * endpoint must re-send the SHUTDOWN ACK. |
| 4996 | * |
| 4997 | * The return value is the disposition. |
| 4998 | */ |
| 4999 | sctp_disposition_t sctp_sf_do_9_2_shutdown_ack( |
| 5000 | const struct sctp_endpoint *ep, |
| 5001 | const struct sctp_association *asoc, |
| 5002 | const sctp_subtype_t type, |
| 5003 | void *arg, |
| 5004 | sctp_cmd_seq_t *commands) |
| 5005 | { |
| 5006 | struct sctp_chunk *chunk = (struct sctp_chunk *) arg; |
| 5007 | struct sctp_chunk *reply; |
| 5008 | |
| 5009 | /* There are 2 ways of getting here: |
| 5010 | * 1) called in response to a SHUTDOWN chunk |
| 5011 | * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued. |
| 5012 | * |
| 5013 | * For the case (2), the arg parameter is set to NULL. We need |
| 5014 | * to check that we have a chunk before accessing it's fields. |
| 5015 | */ |
| 5016 | if (chunk) { |
| 5017 | if (!sctp_vtag_verify(chunk, asoc)) |
| 5018 | return sctp_sf_pdiscard(ep, asoc, type, arg, commands); |
| 5019 | |
| 5020 | /* Make sure that the SHUTDOWN chunk has a valid length. */ |
| 5021 | if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t))) |
| 5022 | return sctp_sf_violation_chunklen(ep, asoc, type, arg, |
| 5023 | commands); |
| 5024 | } |
| 5025 | |
| 5026 | /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver |
| 5027 | * shall send a SHUTDOWN ACK ... |
| 5028 | */ |
| 5029 | reply = sctp_make_shutdown_ack(asoc, chunk); |
| 5030 | if (!reply) |
| 5031 | goto nomem; |
| 5032 | |
| 5033 | /* Set the transport for the SHUTDOWN ACK chunk and the timeout for |
| 5034 | * the T2-shutdown timer. |
| 5035 | */ |
| 5036 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); |
| 5037 | |
| 5038 | /* and start/restart a T2-shutdown timer of its own, */ |
| 5039 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
| 5040 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
| 5041 | |
| 5042 | if (asoc->autoclose) |
| 5043 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| 5044 | SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE)); |
| 5045 | |
| 5046 | /* Enter the SHUTDOWN-ACK-SENT state. */ |
| 5047 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| 5048 | SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT)); |
| 5049 | |
| 5050 | /* sctp-implguide 2.10 Issues with Heartbeating and failover |
| 5051 | * |
| 5052 | * HEARTBEAT ... is discontinued after sending either SHUTDOWN |
| 5053 | * or SHUTDOWN-ACK. |
| 5054 | */ |
| 5055 | sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL()); |
| 5056 | |
| 5057 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
| 5058 | |
| 5059 | return SCTP_DISPOSITION_CONSUME; |
| 5060 | |
| 5061 | nomem: |
| 5062 | return SCTP_DISPOSITION_NOMEM; |
| 5063 | } |
| 5064 | |
| 5065 | /* |
| 5066 | * Ignore the event defined as other |
| 5067 | * |
| 5068 | * The return value is the disposition of the event. |
| 5069 | */ |
| 5070 | sctp_disposition_t sctp_sf_ignore_other(const struct sctp_endpoint *ep, |
| 5071 | const struct sctp_association *asoc, |
| 5072 | const sctp_subtype_t type, |
| 5073 | void *arg, |
| 5074 | sctp_cmd_seq_t *commands) |
| 5075 | { |
| 5076 | SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type.other); |
| 5077 | return SCTP_DISPOSITION_DISCARD; |
| 5078 | } |
| 5079 | |
| 5080 | /************************************************************ |
| 5081 | * These are the state functions for handling timeout events. |
| 5082 | ************************************************************/ |
| 5083 | |
| 5084 | /* |
| 5085 | * RTX Timeout |
| 5086 | * |
| 5087 | * Section: 6.3.3 Handle T3-rtx Expiration |
| 5088 | * |
| 5089 | * Whenever the retransmission timer T3-rtx expires for a destination |
| 5090 | * address, do the following: |
| 5091 | * [See below] |
| 5092 | * |
| 5093 | * The return value is the disposition of the chunk. |
| 5094 | */ |
| 5095 | sctp_disposition_t sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint *ep, |
| 5096 | const struct sctp_association *asoc, |
| 5097 | const sctp_subtype_t type, |
| 5098 | void *arg, |
| 5099 | sctp_cmd_seq_t *commands) |
| 5100 | { |
| 5101 | struct sctp_transport *transport = arg; |
| 5102 | |
| 5103 | SCTP_INC_STATS(SCTP_MIB_T3_RTX_EXPIREDS); |
| 5104 | |
| 5105 | if (asoc->overall_error_count >= asoc->max_retrans) { |
| 5106 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| 5107 | SCTP_ERROR(ETIMEDOUT)); |
| 5108 | /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */ |
| 5109 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
| 5110 | SCTP_PERR(SCTP_ERROR_NO_ERROR)); |
| 5111 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
| 5112 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); |
| 5113 | return SCTP_DISPOSITION_DELETE_TCB; |
| 5114 | } |
| 5115 | |
| 5116 | /* E1) For the destination address for which the timer |
| 5117 | * expires, adjust its ssthresh with rules defined in Section |
| 5118 | * 7.2.3 and set the cwnd <- MTU. |
| 5119 | */ |
| 5120 | |
| 5121 | /* E2) For the destination address for which the timer |
| 5122 | * expires, set RTO <- RTO * 2 ("back off the timer"). The |
| 5123 | * maximum value discussed in rule C7 above (RTO.max) may be |
| 5124 | * used to provide an upper bound to this doubling operation. |
| 5125 | */ |
| 5126 | |
| 5127 | /* E3) Determine how many of the earliest (i.e., lowest TSN) |
| 5128 | * outstanding DATA chunks for the address for which the |
| 5129 | * T3-rtx has expired will fit into a single packet, subject |
| 5130 | * to the MTU constraint for the path corresponding to the |
| 5131 | * destination transport address to which the retransmission |
| 5132 | * is being sent (this may be different from the address for |
| 5133 | * which the timer expires [see Section 6.4]). Call this |
| 5134 | * value K. Bundle and retransmit those K DATA chunks in a |
| 5135 | * single packet to the destination endpoint. |
| 5136 | * |
| 5137 | * Note: Any DATA chunks that were sent to the address for |
| 5138 | * which the T3-rtx timer expired but did not fit in one MTU |
| 5139 | * (rule E3 above), should be marked for retransmission and |
| 5140 | * sent as soon as cwnd allows (normally when a SACK arrives). |
| 5141 | */ |
| 5142 | |
| 5143 | /* Do some failure management (Section 8.2). */ |
| 5144 | sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport)); |
| 5145 | |
| 5146 | /* NB: Rules E4 and F1 are implicit in R1. */ |
| 5147 | sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport)); |
| 5148 | |
| 5149 | return SCTP_DISPOSITION_CONSUME; |
| 5150 | } |
| 5151 | |
| 5152 | /* |
| 5153 | * Generate delayed SACK on timeout |
| 5154 | * |
| 5155 | * Section: 6.2 Acknowledgement on Reception of DATA Chunks |
| 5156 | * |
| 5157 | * The guidelines on delayed acknowledgement algorithm specified in |
| 5158 | * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an |
| 5159 | * acknowledgement SHOULD be generated for at least every second packet |
| 5160 | * (not every second DATA chunk) received, and SHOULD be generated |
| 5161 | * within 200 ms of the arrival of any unacknowledged DATA chunk. In |
| 5162 | * some situations it may be beneficial for an SCTP transmitter to be |
| 5163 | * more conservative than the algorithms detailed in this document |
| 5164 | * allow. However, an SCTP transmitter MUST NOT be more aggressive than |
| 5165 | * the following algorithms allow. |
| 5166 | */ |
| 5167 | sctp_disposition_t sctp_sf_do_6_2_sack(const struct sctp_endpoint *ep, |
| 5168 | const struct sctp_association *asoc, |
| 5169 | const sctp_subtype_t type, |
| 5170 | void *arg, |
| 5171 | sctp_cmd_seq_t *commands) |
| 5172 | { |
| 5173 | SCTP_INC_STATS(SCTP_MIB_DELAY_SACK_EXPIREDS); |
| 5174 | sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE()); |
| 5175 | return SCTP_DISPOSITION_CONSUME; |
| 5176 | } |
| 5177 | |
| 5178 | /* |
| 5179 | * sctp_sf_t1_init_timer_expire |
| 5180 | * |
| 5181 | * Section: 4 Note: 2 |
| 5182 | * Verification Tag: |
| 5183 | * Inputs |
| 5184 | * (endpoint, asoc) |
| 5185 | * |
| 5186 | * RFC 2960 Section 4 Notes |
| 5187 | * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT |
| 5188 | * and re-start the T1-init timer without changing state. This MUST |
| 5189 | * be repeated up to 'Max.Init.Retransmits' times. After that, the |
| 5190 | * endpoint MUST abort the initialization process and report the |
| 5191 | * error to SCTP user. |
| 5192 | * |
| 5193 | * Outputs |
| 5194 | * (timers, events) |
| 5195 | * |
| 5196 | */ |
| 5197 | sctp_disposition_t sctp_sf_t1_init_timer_expire(const struct sctp_endpoint *ep, |
| 5198 | const struct sctp_association *asoc, |
| 5199 | const sctp_subtype_t type, |
| 5200 | void *arg, |
| 5201 | sctp_cmd_seq_t *commands) |
| 5202 | { |
| 5203 | struct sctp_chunk *repl = NULL; |
| 5204 | struct sctp_bind_addr *bp; |
| 5205 | int attempts = asoc->init_err_counter + 1; |
| 5206 | |
| 5207 | SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n"); |
| 5208 | SCTP_INC_STATS(SCTP_MIB_T1_INIT_EXPIREDS); |
| 5209 | |
| 5210 | if (attempts <= asoc->max_init_attempts) { |
| 5211 | bp = (struct sctp_bind_addr *) &asoc->base.bind_addr; |
| 5212 | repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0); |
| 5213 | if (!repl) |
| 5214 | return SCTP_DISPOSITION_NOMEM; |
| 5215 | |
| 5216 | /* Choose transport for INIT. */ |
| 5217 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT, |
| 5218 | SCTP_CHUNK(repl)); |
| 5219 | |
| 5220 | /* Issue a sideeffect to do the needed accounting. */ |
| 5221 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART, |
| 5222 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); |
| 5223 | |
| 5224 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
| 5225 | } else { |
| 5226 | SCTP_DEBUG_PRINTK("Giving up on INIT, attempts: %d" |
| 5227 | " max_init_attempts: %d\n", |
| 5228 | attempts, asoc->max_init_attempts); |
| 5229 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| 5230 | SCTP_ERROR(ETIMEDOUT)); |
| 5231 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, |
| 5232 | SCTP_PERR(SCTP_ERROR_NO_ERROR)); |
| 5233 | return SCTP_DISPOSITION_DELETE_TCB; |
| 5234 | } |
| 5235 | |
| 5236 | return SCTP_DISPOSITION_CONSUME; |
| 5237 | } |
| 5238 | |
| 5239 | /* |
| 5240 | * sctp_sf_t1_cookie_timer_expire |
| 5241 | * |
| 5242 | * Section: 4 Note: 2 |
| 5243 | * Verification Tag: |
| 5244 | * Inputs |
| 5245 | * (endpoint, asoc) |
| 5246 | * |
| 5247 | * RFC 2960 Section 4 Notes |
| 5248 | * 3) If the T1-cookie timer expires, the endpoint MUST retransmit |
| 5249 | * COOKIE ECHO and re-start the T1-cookie timer without changing |
| 5250 | * state. This MUST be repeated up to 'Max.Init.Retransmits' times. |
| 5251 | * After that, the endpoint MUST abort the initialization process and |
| 5252 | * report the error to SCTP user. |
| 5253 | * |
| 5254 | * Outputs |
| 5255 | * (timers, events) |
| 5256 | * |
| 5257 | */ |
| 5258 | sctp_disposition_t sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint *ep, |
| 5259 | const struct sctp_association *asoc, |
| 5260 | const sctp_subtype_t type, |
| 5261 | void *arg, |
| 5262 | sctp_cmd_seq_t *commands) |
| 5263 | { |
| 5264 | struct sctp_chunk *repl = NULL; |
| 5265 | int attempts = asoc->init_err_counter + 1; |
| 5266 | |
| 5267 | SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n"); |
| 5268 | SCTP_INC_STATS(SCTP_MIB_T1_COOKIE_EXPIREDS); |
| 5269 | |
| 5270 | if (attempts <= asoc->max_init_attempts) { |
| 5271 | repl = sctp_make_cookie_echo(asoc, NULL); |
| 5272 | if (!repl) |
| 5273 | return SCTP_DISPOSITION_NOMEM; |
| 5274 | |
| 5275 | /* Issue a sideeffect to do the needed accounting. */ |
| 5276 | sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART, |
| 5277 | SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); |
| 5278 | |
| 5279 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl)); |
| 5280 | } else { |
| 5281 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| 5282 | SCTP_ERROR(ETIMEDOUT)); |
| 5283 | sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED, |
| 5284 | SCTP_PERR(SCTP_ERROR_NO_ERROR)); |
| 5285 | return SCTP_DISPOSITION_DELETE_TCB; |
| 5286 | } |
| 5287 | |
| 5288 | return SCTP_DISPOSITION_CONSUME; |
| 5289 | } |
| 5290 | |
| 5291 | /* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN |
| 5292 | * with the updated last sequential TSN received from its peer. |
| 5293 | * |
| 5294 | * An endpoint should limit the number of retransmissions of the |
| 5295 | * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'. |
| 5296 | * If this threshold is exceeded the endpoint should destroy the TCB and |
| 5297 | * MUST report the peer endpoint unreachable to the upper layer (and |
| 5298 | * thus the association enters the CLOSED state). The reception of any |
| 5299 | * packet from its peer (i.e. as the peer sends all of its queued DATA |
| 5300 | * chunks) should clear the endpoint's retransmission count and restart |
| 5301 | * the T2-Shutdown timer, giving its peer ample opportunity to transmit |
| 5302 | * all of its queued DATA chunks that have not yet been sent. |
| 5303 | */ |
| 5304 | sctp_disposition_t sctp_sf_t2_timer_expire(const struct sctp_endpoint *ep, |
| 5305 | const struct sctp_association *asoc, |
| 5306 | const sctp_subtype_t type, |
| 5307 | void *arg, |
| 5308 | sctp_cmd_seq_t *commands) |
| 5309 | { |
| 5310 | struct sctp_chunk *reply = NULL; |
| 5311 | |
| 5312 | SCTP_DEBUG_PRINTK("Timer T2 expired.\n"); |
| 5313 | SCTP_INC_STATS(SCTP_MIB_T2_SHUTDOWN_EXPIREDS); |
| 5314 | |
| 5315 | ((struct sctp_association *)asoc)->shutdown_retries++; |
| 5316 | |
| 5317 | if (asoc->overall_error_count >= asoc->max_retrans) { |
| 5318 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| 5319 | SCTP_ERROR(ETIMEDOUT)); |
| 5320 | /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */ |
| 5321 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
| 5322 | SCTP_PERR(SCTP_ERROR_NO_ERROR)); |
| 5323 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
| 5324 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); |
| 5325 | return SCTP_DISPOSITION_DELETE_TCB; |
| 5326 | } |
| 5327 | |
| 5328 | switch (asoc->state) { |
| 5329 | case SCTP_STATE_SHUTDOWN_SENT: |
| 5330 | reply = sctp_make_shutdown(asoc, NULL); |
| 5331 | break; |
| 5332 | |
| 5333 | case SCTP_STATE_SHUTDOWN_ACK_SENT: |
| 5334 | reply = sctp_make_shutdown_ack(asoc, NULL); |
| 5335 | break; |
| 5336 | |
| 5337 | default: |
| 5338 | BUG(); |
| 5339 | break; |
| 5340 | } |
| 5341 | |
| 5342 | if (!reply) |
| 5343 | goto nomem; |
| 5344 | |
| 5345 | /* Do some failure management (Section 8.2). */ |
| 5346 | sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, |
| 5347 | SCTP_TRANSPORT(asoc->shutdown_last_sent_to)); |
| 5348 | |
| 5349 | /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for |
| 5350 | * the T2-shutdown timer. |
| 5351 | */ |
| 5352 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply)); |
| 5353 | |
| 5354 | /* Restart the T2-shutdown timer. */ |
| 5355 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
| 5356 | SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN)); |
| 5357 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
| 5358 | return SCTP_DISPOSITION_CONSUME; |
| 5359 | |
| 5360 | nomem: |
| 5361 | return SCTP_DISPOSITION_NOMEM; |
| 5362 | } |
| 5363 | |
| 5364 | /* |
| 5365 | * ADDIP Section 4.1 ASCONF CHunk Procedures |
| 5366 | * If the T4 RTO timer expires the endpoint should do B1 to B5 |
| 5367 | */ |
| 5368 | sctp_disposition_t sctp_sf_t4_timer_expire( |
| 5369 | const struct sctp_endpoint *ep, |
| 5370 | const struct sctp_association *asoc, |
| 5371 | const sctp_subtype_t type, |
| 5372 | void *arg, |
| 5373 | sctp_cmd_seq_t *commands) |
| 5374 | { |
| 5375 | struct sctp_chunk *chunk = asoc->addip_last_asconf; |
| 5376 | struct sctp_transport *transport = chunk->transport; |
| 5377 | |
| 5378 | SCTP_INC_STATS(SCTP_MIB_T4_RTO_EXPIREDS); |
| 5379 | |
| 5380 | /* ADDIP 4.1 B1) Increment the error counters and perform path failure |
| 5381 | * detection on the appropriate destination address as defined in |
| 5382 | * RFC2960 [5] section 8.1 and 8.2. |
| 5383 | */ |
| 5384 | sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport)); |
| 5385 | |
| 5386 | /* Reconfig T4 timer and transport. */ |
| 5387 | sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk)); |
| 5388 | |
| 5389 | /* ADDIP 4.1 B2) Increment the association error counters and perform |
| 5390 | * endpoint failure detection on the association as defined in |
| 5391 | * RFC2960 [5] section 8.1 and 8.2. |
| 5392 | * association error counter is incremented in SCTP_CMD_STRIKE. |
| 5393 | */ |
| 5394 | if (asoc->overall_error_count >= asoc->max_retrans) { |
| 5395 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, |
| 5396 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); |
| 5397 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| 5398 | SCTP_ERROR(ETIMEDOUT)); |
| 5399 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
| 5400 | SCTP_PERR(SCTP_ERROR_NO_ERROR)); |
| 5401 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
| 5402 | SCTP_INC_STATS(SCTP_MIB_CURRESTAB); |
| 5403 | return SCTP_DISPOSITION_ABORT; |
| 5404 | } |
| 5405 | |
| 5406 | /* ADDIP 4.1 B3) Back-off the destination address RTO value to which |
| 5407 | * the ASCONF chunk was sent by doubling the RTO timer value. |
| 5408 | * This is done in SCTP_CMD_STRIKE. |
| 5409 | */ |
| 5410 | |
| 5411 | /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible |
| 5412 | * choose an alternate destination address (please refer to RFC2960 |
| 5413 | * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this |
| 5414 | * chunk, it MUST be the same (including its serial number) as the last |
| 5415 | * ASCONF sent. |
| 5416 | */ |
| 5417 | sctp_chunk_hold(asoc->addip_last_asconf); |
| 5418 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
| 5419 | SCTP_CHUNK(asoc->addip_last_asconf)); |
| 5420 | |
| 5421 | /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different |
| 5422 | * destination is selected, then the RTO used will be that of the new |
| 5423 | * destination address. |
| 5424 | */ |
| 5425 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, |
| 5426 | SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); |
| 5427 | |
| 5428 | return SCTP_DISPOSITION_CONSUME; |
| 5429 | } |
| 5430 | |
| 5431 | /* sctpimpguide-05 Section 2.12.2 |
| 5432 | * The sender of the SHUTDOWN MAY also start an overall guard timer |
| 5433 | * 'T5-shutdown-guard' to bound the overall time for shutdown sequence. |
| 5434 | * At the expiration of this timer the sender SHOULD abort the association |
| 5435 | * by sending an ABORT chunk. |
| 5436 | */ |
| 5437 | sctp_disposition_t sctp_sf_t5_timer_expire(const struct sctp_endpoint *ep, |
| 5438 | const struct sctp_association *asoc, |
| 5439 | const sctp_subtype_t type, |
| 5440 | void *arg, |
| 5441 | sctp_cmd_seq_t *commands) |
| 5442 | { |
| 5443 | struct sctp_chunk *reply = NULL; |
| 5444 | |
| 5445 | SCTP_DEBUG_PRINTK("Timer T5 expired.\n"); |
| 5446 | SCTP_INC_STATS(SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS); |
| 5447 | |
| 5448 | reply = sctp_make_abort(asoc, NULL, 0); |
| 5449 | if (!reply) |
| 5450 | goto nomem; |
| 5451 | |
| 5452 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply)); |
| 5453 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| 5454 | SCTP_ERROR(ETIMEDOUT)); |
| 5455 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
| 5456 | SCTP_PERR(SCTP_ERROR_NO_ERROR)); |
| 5457 | |
| 5458 | return SCTP_DISPOSITION_DELETE_TCB; |
| 5459 | nomem: |
| 5460 | return SCTP_DISPOSITION_NOMEM; |
| 5461 | } |
| 5462 | |
| 5463 | /* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires, |
| 5464 | * the association is automatically closed by starting the shutdown process. |
| 5465 | * The work that needs to be done is same as when SHUTDOWN is initiated by |
| 5466 | * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown(). |
| 5467 | */ |
| 5468 | sctp_disposition_t sctp_sf_autoclose_timer_expire( |
| 5469 | const struct sctp_endpoint *ep, |
| 5470 | const struct sctp_association *asoc, |
| 5471 | const sctp_subtype_t type, |
| 5472 | void *arg, |
| 5473 | sctp_cmd_seq_t *commands) |
| 5474 | { |
| 5475 | int disposition; |
| 5476 | |
| 5477 | SCTP_INC_STATS(SCTP_MIB_AUTOCLOSE_EXPIREDS); |
| 5478 | |
| 5479 | /* From 9.2 Shutdown of an Association |
| 5480 | * Upon receipt of the SHUTDOWN primitive from its upper |
| 5481 | * layer, the endpoint enters SHUTDOWN-PENDING state and |
| 5482 | * remains there until all outstanding data has been |
| 5483 | * acknowledged by its peer. The endpoint accepts no new data |
| 5484 | * from its upper layer, but retransmits data to the far end |
| 5485 | * if necessary to fill gaps. |
| 5486 | */ |
| 5487 | sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, |
| 5488 | SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING)); |
| 5489 | |
| 5490 | /* sctpimpguide-05 Section 2.12.2 |
| 5491 | * The sender of the SHUTDOWN MAY also start an overall guard timer |
| 5492 | * 'T5-shutdown-guard' to bound the overall time for shutdown sequence. |
| 5493 | */ |
| 5494 | sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START, |
| 5495 | SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD)); |
| 5496 | disposition = SCTP_DISPOSITION_CONSUME; |
| 5497 | if (sctp_outq_is_empty(&asoc->outqueue)) { |
| 5498 | disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type, |
| 5499 | arg, commands); |
| 5500 | } |
| 5501 | return disposition; |
| 5502 | } |
| 5503 | |
| 5504 | /***************************************************************************** |
| 5505 | * These are sa state functions which could apply to all types of events. |
| 5506 | ****************************************************************************/ |
| 5507 | |
| 5508 | /* |
| 5509 | * This table entry is not implemented. |
| 5510 | * |
| 5511 | * Inputs |
| 5512 | * (endpoint, asoc, chunk) |
| 5513 | * |
| 5514 | * The return value is the disposition of the chunk. |
| 5515 | */ |
| 5516 | sctp_disposition_t sctp_sf_not_impl(const struct sctp_endpoint *ep, |
| 5517 | const struct sctp_association *asoc, |
| 5518 | const sctp_subtype_t type, |
| 5519 | void *arg, |
| 5520 | sctp_cmd_seq_t *commands) |
| 5521 | { |
| 5522 | return SCTP_DISPOSITION_NOT_IMPL; |
| 5523 | } |
| 5524 | |
| 5525 | /* |
| 5526 | * This table entry represents a bug. |
| 5527 | * |
| 5528 | * Inputs |
| 5529 | * (endpoint, asoc, chunk) |
| 5530 | * |
| 5531 | * The return value is the disposition of the chunk. |
| 5532 | */ |
| 5533 | sctp_disposition_t sctp_sf_bug(const struct sctp_endpoint *ep, |
| 5534 | const struct sctp_association *asoc, |
| 5535 | const sctp_subtype_t type, |
| 5536 | void *arg, |
| 5537 | sctp_cmd_seq_t *commands) |
| 5538 | { |
| 5539 | return SCTP_DISPOSITION_BUG; |
| 5540 | } |
| 5541 | |
| 5542 | /* |
| 5543 | * This table entry represents the firing of a timer in the wrong state. |
| 5544 | * Since timer deletion cannot be guaranteed a timer 'may' end up firing |
| 5545 | * when the association is in the wrong state. This event should |
| 5546 | * be ignored, so as to prevent any rearming of the timer. |
| 5547 | * |
| 5548 | * Inputs |
| 5549 | * (endpoint, asoc, chunk) |
| 5550 | * |
| 5551 | * The return value is the disposition of the chunk. |
| 5552 | */ |
| 5553 | sctp_disposition_t sctp_sf_timer_ignore(const struct sctp_endpoint *ep, |
| 5554 | const struct sctp_association *asoc, |
| 5555 | const sctp_subtype_t type, |
| 5556 | void *arg, |
| 5557 | sctp_cmd_seq_t *commands) |
| 5558 | { |
| 5559 | SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type.chunk); |
| 5560 | return SCTP_DISPOSITION_CONSUME; |
| 5561 | } |
| 5562 | |
| 5563 | /******************************************************************** |
| 5564 | * 2nd Level Abstractions |
| 5565 | ********************************************************************/ |
| 5566 | |
| 5567 | /* Pull the SACK chunk based on the SACK header. */ |
| 5568 | static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk) |
| 5569 | { |
| 5570 | struct sctp_sackhdr *sack; |
| 5571 | unsigned int len; |
| 5572 | __u16 num_blocks; |
| 5573 | __u16 num_dup_tsns; |
| 5574 | |
| 5575 | /* Protect ourselves from reading too far into |
| 5576 | * the skb from a bogus sender. |
| 5577 | */ |
| 5578 | sack = (struct sctp_sackhdr *) chunk->skb->data; |
| 5579 | |
| 5580 | num_blocks = ntohs(sack->num_gap_ack_blocks); |
| 5581 | num_dup_tsns = ntohs(sack->num_dup_tsns); |
| 5582 | len = sizeof(struct sctp_sackhdr); |
| 5583 | len += (num_blocks + num_dup_tsns) * sizeof(__u32); |
| 5584 | if (len > chunk->skb->len) |
| 5585 | return NULL; |
| 5586 | |
| 5587 | skb_pull(chunk->skb, len); |
| 5588 | |
| 5589 | return sack; |
| 5590 | } |
| 5591 | |
| 5592 | /* Create an ABORT packet to be sent as a response, with the specified |
| 5593 | * error causes. |
| 5594 | */ |
| 5595 | static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep, |
| 5596 | const struct sctp_association *asoc, |
| 5597 | struct sctp_chunk *chunk, |
| 5598 | const void *payload, |
| 5599 | size_t paylen) |
| 5600 | { |
| 5601 | struct sctp_packet *packet; |
| 5602 | struct sctp_chunk *abort; |
| 5603 | |
| 5604 | packet = sctp_ootb_pkt_new(asoc, chunk); |
| 5605 | |
| 5606 | if (packet) { |
| 5607 | /* Make an ABORT. |
| 5608 | * The T bit will be set if the asoc is NULL. |
| 5609 | */ |
| 5610 | abort = sctp_make_abort(asoc, chunk, paylen); |
| 5611 | if (!abort) { |
| 5612 | sctp_ootb_pkt_free(packet); |
| 5613 | return NULL; |
| 5614 | } |
| 5615 | |
| 5616 | /* Reflect vtag if T-Bit is set */ |
| 5617 | if (sctp_test_T_bit(abort)) |
| 5618 | packet->vtag = ntohl(chunk->sctp_hdr->vtag); |
| 5619 | |
| 5620 | /* Add specified error causes, i.e., payload, to the |
| 5621 | * end of the chunk. |
| 5622 | */ |
| 5623 | sctp_addto_chunk(abort, paylen, payload); |
| 5624 | |
| 5625 | /* Set the skb to the belonging sock for accounting. */ |
| 5626 | abort->skb->sk = ep->base.sk; |
| 5627 | |
| 5628 | sctp_packet_append_chunk(packet, abort); |
| 5629 | |
| 5630 | } |
| 5631 | |
| 5632 | return packet; |
| 5633 | } |
| 5634 | |
| 5635 | /* Allocate a packet for responding in the OOTB conditions. */ |
| 5636 | static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc, |
| 5637 | const struct sctp_chunk *chunk) |
| 5638 | { |
| 5639 | struct sctp_packet *packet; |
| 5640 | struct sctp_transport *transport; |
| 5641 | __u16 sport; |
| 5642 | __u16 dport; |
| 5643 | __u32 vtag; |
| 5644 | |
| 5645 | /* Get the source and destination port from the inbound packet. */ |
| 5646 | sport = ntohs(chunk->sctp_hdr->dest); |
| 5647 | dport = ntohs(chunk->sctp_hdr->source); |
| 5648 | |
| 5649 | /* The V-tag is going to be the same as the inbound packet if no |
| 5650 | * association exists, otherwise, use the peer's vtag. |
| 5651 | */ |
| 5652 | if (asoc) { |
| 5653 | /* Special case the INIT-ACK as there is no peer's vtag |
| 5654 | * yet. |
| 5655 | */ |
| 5656 | switch(chunk->chunk_hdr->type) { |
| 5657 | case SCTP_CID_INIT_ACK: |
| 5658 | { |
| 5659 | sctp_initack_chunk_t *initack; |
| 5660 | |
| 5661 | initack = (sctp_initack_chunk_t *)chunk->chunk_hdr; |
| 5662 | vtag = ntohl(initack->init_hdr.init_tag); |
| 5663 | break; |
| 5664 | } |
| 5665 | default: |
| 5666 | vtag = asoc->peer.i.init_tag; |
| 5667 | break; |
| 5668 | } |
| 5669 | } else { |
| 5670 | /* Special case the INIT and stale COOKIE_ECHO as there is no |
| 5671 | * vtag yet. |
| 5672 | */ |
| 5673 | switch(chunk->chunk_hdr->type) { |
| 5674 | case SCTP_CID_INIT: |
| 5675 | { |
| 5676 | sctp_init_chunk_t *init; |
| 5677 | |
| 5678 | init = (sctp_init_chunk_t *)chunk->chunk_hdr; |
| 5679 | vtag = ntohl(init->init_hdr.init_tag); |
| 5680 | break; |
| 5681 | } |
| 5682 | default: |
| 5683 | vtag = ntohl(chunk->sctp_hdr->vtag); |
| 5684 | break; |
| 5685 | } |
| 5686 | } |
| 5687 | |
| 5688 | /* Make a transport for the bucket, Eliza... */ |
| 5689 | transport = sctp_transport_new(sctp_source(chunk), GFP_ATOMIC); |
| 5690 | if (!transport) |
| 5691 | goto nomem; |
| 5692 | |
| 5693 | /* Cache a route for the transport with the chunk's destination as |
| 5694 | * the source address. |
| 5695 | */ |
| 5696 | sctp_transport_route(transport, (union sctp_addr *)&chunk->dest, |
| 5697 | sctp_sk(sctp_get_ctl_sock())); |
| 5698 | |
| 5699 | packet = sctp_packet_init(&transport->packet, transport, sport, dport); |
| 5700 | packet = sctp_packet_config(packet, vtag, 0); |
| 5701 | |
| 5702 | return packet; |
| 5703 | |
| 5704 | nomem: |
| 5705 | return NULL; |
| 5706 | } |
| 5707 | |
| 5708 | /* Free the packet allocated earlier for responding in the OOTB condition. */ |
| 5709 | void sctp_ootb_pkt_free(struct sctp_packet *packet) |
| 5710 | { |
| 5711 | sctp_transport_free(packet->transport); |
| 5712 | } |
| 5713 | |
| 5714 | /* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */ |
| 5715 | static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep, |
| 5716 | const struct sctp_association *asoc, |
| 5717 | const struct sctp_chunk *chunk, |
| 5718 | sctp_cmd_seq_t *commands, |
| 5719 | struct sctp_chunk *err_chunk) |
| 5720 | { |
| 5721 | struct sctp_packet *packet; |
| 5722 | |
| 5723 | if (err_chunk) { |
| 5724 | packet = sctp_ootb_pkt_new(asoc, chunk); |
| 5725 | if (packet) { |
| 5726 | struct sctp_signed_cookie *cookie; |
| 5727 | |
| 5728 | /* Override the OOTB vtag from the cookie. */ |
| 5729 | cookie = chunk->subh.cookie_hdr; |
| 5730 | packet->vtag = cookie->c.peer_vtag; |
| 5731 | |
| 5732 | /* Set the skb to the belonging sock for accounting. */ |
| 5733 | err_chunk->skb->sk = ep->base.sk; |
| 5734 | sctp_packet_append_chunk(packet, err_chunk); |
| 5735 | sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, |
| 5736 | SCTP_PACKET(packet)); |
| 5737 | SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS); |
| 5738 | } else |
| 5739 | sctp_chunk_free (err_chunk); |
| 5740 | } |
| 5741 | } |
| 5742 | |
| 5743 | |
| 5744 | /* Process a data chunk */ |
| 5745 | static int sctp_eat_data(const struct sctp_association *asoc, |
| 5746 | struct sctp_chunk *chunk, |
| 5747 | sctp_cmd_seq_t *commands) |
| 5748 | { |
| 5749 | sctp_datahdr_t *data_hdr; |
| 5750 | struct sctp_chunk *err; |
| 5751 | size_t datalen; |
| 5752 | sctp_verb_t deliver; |
| 5753 | int tmp; |
| 5754 | __u32 tsn; |
| 5755 | struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map; |
| 5756 | struct sock *sk = asoc->base.sk; |
| 5757 | |
| 5758 | data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data; |
| 5759 | skb_pull(chunk->skb, sizeof(sctp_datahdr_t)); |
| 5760 | |
| 5761 | tsn = ntohl(data_hdr->tsn); |
| 5762 | SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn); |
| 5763 | |
| 5764 | /* ASSERT: Now skb->data is really the user data. */ |
| 5765 | |
| 5766 | /* Process ECN based congestion. |
| 5767 | * |
| 5768 | * Since the chunk structure is reused for all chunks within |
| 5769 | * a packet, we use ecn_ce_done to track if we've already |
| 5770 | * done CE processing for this packet. |
| 5771 | * |
| 5772 | * We need to do ECN processing even if we plan to discard the |
| 5773 | * chunk later. |
| 5774 | */ |
| 5775 | |
| 5776 | if (!chunk->ecn_ce_done) { |
| 5777 | struct sctp_af *af; |
| 5778 | chunk->ecn_ce_done = 1; |
| 5779 | |
| 5780 | af = sctp_get_af_specific( |
| 5781 | ipver2af(ip_hdr(chunk->skb)->version)); |
| 5782 | |
| 5783 | if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) { |
| 5784 | /* Do real work as sideffect. */ |
| 5785 | sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE, |
| 5786 | SCTP_U32(tsn)); |
| 5787 | } |
| 5788 | } |
| 5789 | |
| 5790 | tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn); |
| 5791 | if (tmp < 0) { |
| 5792 | /* The TSN is too high--silently discard the chunk and |
| 5793 | * count on it getting retransmitted later. |
| 5794 | */ |
| 5795 | return SCTP_IERROR_HIGH_TSN; |
| 5796 | } else if (tmp > 0) { |
| 5797 | /* This is a duplicate. Record it. */ |
| 5798 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn)); |
| 5799 | return SCTP_IERROR_DUP_TSN; |
| 5800 | } |
| 5801 | |
| 5802 | /* This is a new TSN. */ |
| 5803 | |
| 5804 | /* Discard if there is no room in the receive window. |
| 5805 | * Actually, allow a little bit of overflow (up to a MTU). |
| 5806 | */ |
| 5807 | datalen = ntohs(chunk->chunk_hdr->length); |
| 5808 | datalen -= sizeof(sctp_data_chunk_t); |
| 5809 | |
| 5810 | deliver = SCTP_CMD_CHUNK_ULP; |
| 5811 | |
| 5812 | /* Think about partial delivery. */ |
| 5813 | if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) { |
| 5814 | |
| 5815 | /* Even if we don't accept this chunk there is |
| 5816 | * memory pressure. |
| 5817 | */ |
| 5818 | sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL()); |
| 5819 | } |
| 5820 | |
| 5821 | /* Spill over rwnd a little bit. Note: While allowed, this spill over |
| 5822 | * seems a bit troublesome in that frag_point varies based on |
| 5823 | * PMTU. In cases, such as loopback, this might be a rather |
| 5824 | * large spill over. |
| 5825 | */ |
| 5826 | if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over || |
| 5827 | (datalen > asoc->rwnd + asoc->frag_point))) { |
| 5828 | |
| 5829 | /* If this is the next TSN, consider reneging to make |
| 5830 | * room. Note: Playing nice with a confused sender. A |
| 5831 | * malicious sender can still eat up all our buffer |
| 5832 | * space and in the future we may want to detect and |
| 5833 | * do more drastic reneging. |
| 5834 | */ |
| 5835 | if (sctp_tsnmap_has_gap(map) && |
| 5836 | (sctp_tsnmap_get_ctsn(map) + 1) == tsn) { |
| 5837 | SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn); |
| 5838 | deliver = SCTP_CMD_RENEGE; |
| 5839 | } else { |
| 5840 | SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, " |
| 5841 | "rwnd: %d\n", tsn, datalen, |
| 5842 | asoc->rwnd); |
| 5843 | return SCTP_IERROR_IGNORE_TSN; |
| 5844 | } |
| 5845 | } |
| 5846 | |
| 5847 | /* |
| 5848 | * Also try to renege to limit our memory usage in the event that |
| 5849 | * we are under memory pressure |
| 5850 | * If we can't renege, don't worry about it, the sk_rmem_schedule |
| 5851 | * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our |
| 5852 | * memory usage too much |
| 5853 | */ |
| 5854 | if (*sk->sk_prot_creator->memory_pressure) { |
| 5855 | if (sctp_tsnmap_has_gap(map) && |
| 5856 | (sctp_tsnmap_get_ctsn(map) + 1) == tsn) { |
| 5857 | SCTP_DEBUG_PRINTK("Under Pressure! Reneging for tsn:%u\n", tsn); |
| 5858 | deliver = SCTP_CMD_RENEGE; |
| 5859 | } |
| 5860 | } |
| 5861 | |
| 5862 | /* |
| 5863 | * Section 3.3.10.9 No User Data (9) |
| 5864 | * |
| 5865 | * Cause of error |
| 5866 | * --------------- |
| 5867 | * No User Data: This error cause is returned to the originator of a |
| 5868 | * DATA chunk if a received DATA chunk has no user data. |
| 5869 | */ |
| 5870 | if (unlikely(0 == datalen)) { |
| 5871 | err = sctp_make_abort_no_data(asoc, chunk, tsn); |
| 5872 | if (err) { |
| 5873 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
| 5874 | SCTP_CHUNK(err)); |
| 5875 | } |
| 5876 | /* We are going to ABORT, so we might as well stop |
| 5877 | * processing the rest of the chunks in the packet. |
| 5878 | */ |
| 5879 | sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL()); |
| 5880 | sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, |
| 5881 | SCTP_ERROR(ECONNABORTED)); |
| 5882 | sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, |
| 5883 | SCTP_PERR(SCTP_ERROR_NO_DATA)); |
| 5884 | SCTP_INC_STATS(SCTP_MIB_ABORTEDS); |
| 5885 | SCTP_DEC_STATS(SCTP_MIB_CURRESTAB); |
| 5886 | return SCTP_IERROR_NO_DATA; |
| 5887 | } |
| 5888 | |
| 5889 | /* If definately accepting the DATA chunk, record its TSN, otherwise |
| 5890 | * wait for renege processing. |
| 5891 | */ |
| 5892 | if (SCTP_CMD_CHUNK_ULP == deliver) |
| 5893 | sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn)); |
| 5894 | |
| 5895 | chunk->data_accepted = 1; |
| 5896 | |
| 5897 | /* Note: Some chunks may get overcounted (if we drop) or overcounted |
| 5898 | * if we renege and the chunk arrives again. |
| 5899 | */ |
| 5900 | if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) |
| 5901 | SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS); |
| 5902 | else |
| 5903 | SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS); |
| 5904 | |
| 5905 | /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number |
| 5906 | * |
| 5907 | * If an endpoint receive a DATA chunk with an invalid stream |
| 5908 | * identifier, it shall acknowledge the reception of the DATA chunk |
| 5909 | * following the normal procedure, immediately send an ERROR chunk |
| 5910 | * with cause set to "Invalid Stream Identifier" (See Section 3.3.10) |
| 5911 | * and discard the DATA chunk. |
| 5912 | */ |
| 5913 | if (ntohs(data_hdr->stream) >= asoc->c.sinit_max_instreams) { |
| 5914 | err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM, |
| 5915 | &data_hdr->stream, |
| 5916 | sizeof(data_hdr->stream)); |
| 5917 | if (err) |
| 5918 | sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, |
| 5919 | SCTP_CHUNK(err)); |
| 5920 | return SCTP_IERROR_BAD_STREAM; |
| 5921 | } |
| 5922 | |
| 5923 | /* Send the data up to the user. Note: Schedule the |
| 5924 | * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK |
| 5925 | * chunk needs the updated rwnd. |
| 5926 | */ |
| 5927 | sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk)); |
| 5928 | |
| 5929 | return SCTP_IERROR_NO_ERROR; |
| 5930 | } |