1 /* SCTP kernel implementation 2 * (C) Copyright IBM Corp. 2001, 2004 3 * Copyright (c) 1999 Cisco, Inc. 4 * Copyright (c) 1999-2001 Motorola, Inc. 5 * 6 * This file is part of the SCTP kernel implementation 7 * 8 * These functions work with the state functions in sctp_sm_statefuns.c 9 * to implement that state operations. These functions implement the 10 * steps which require modifying existing data structures. 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, see 26 * <http://www.gnu.org/licenses/>. 27 * 28 * Please send any bug reports or fixes you make to the 29 * email address(es): 30 * lksctp developers <linux-sctp@vger.kernel.org> 31 * 32 * Written or modified by: 33 * La Monte H.P. Yarroll <piggy@acm.org> 34 * Karl Knutson <karl@athena.chicago.il.us> 35 * Jon Grimm <jgrimm@austin.ibm.com> 36 * Hui Huang <hui.huang@nokia.com> 37 * Dajiang Zhang <dajiang.zhang@nokia.com> 38 * Daisy Chang <daisyc@us.ibm.com> 39 * Sridhar Samudrala <sri@us.ibm.com> 40 * Ardelle Fan <ardelle.fan@intel.com> 41 */ 42 43 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 44 45 #include <linux/skbuff.h> 46 #include <linux/types.h> 47 #include <linux/socket.h> 48 #include <linux/ip.h> 49 #include <linux/gfp.h> 50 #include <net/sock.h> 51 #include <net/sctp/sctp.h> 52 #include <net/sctp/sm.h> 53 54 static int sctp_cmd_interpreter(sctp_event_t event_type, 55 sctp_subtype_t subtype, 56 sctp_state_t state, 57 struct sctp_endpoint *ep, 58 struct sctp_association *asoc, 59 void *event_arg, 60 sctp_disposition_t status, 61 sctp_cmd_seq_t *commands, 62 gfp_t gfp); 63 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype, 64 sctp_state_t state, 65 struct sctp_endpoint *ep, 66 struct sctp_association **asoc, 67 void *event_arg, 68 sctp_disposition_t status, 69 sctp_cmd_seq_t *commands, 70 gfp_t gfp); 71 72 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds, 73 struct sctp_transport *t); 74 /******************************************************************** 75 * Helper functions 76 ********************************************************************/ 77 78 /* A helper function for delayed processing of INET ECN CE bit. */ 79 static void sctp_do_ecn_ce_work(struct sctp_association *asoc, 80 __u32 lowest_tsn) 81 { 82 /* Save the TSN away for comparison when we receive CWR */ 83 84 asoc->last_ecne_tsn = lowest_tsn; 85 asoc->need_ecne = 1; 86 } 87 88 /* Helper function for delayed processing of SCTP ECNE chunk. */ 89 /* RFC 2960 Appendix A 90 * 91 * RFC 2481 details a specific bit for a sender to send in 92 * the header of its next outbound TCP segment to indicate to 93 * its peer that it has reduced its congestion window. This 94 * is termed the CWR bit. For SCTP the same indication is made 95 * by including the CWR chunk. This chunk contains one data 96 * element, i.e. the TSN number that was sent in the ECNE chunk. 97 * This element represents the lowest TSN number in the datagram 98 * that was originally marked with the CE bit. 99 */ 100 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc, 101 __u32 lowest_tsn, 102 struct sctp_chunk *chunk) 103 { 104 struct sctp_chunk *repl; 105 106 /* Our previously transmitted packet ran into some congestion 107 * so we should take action by reducing cwnd and ssthresh 108 * and then ACK our peer that we we've done so by 109 * sending a CWR. 110 */ 111 112 /* First, try to determine if we want to actually lower 113 * our cwnd variables. Only lower them if the ECNE looks more 114 * recent than the last response. 115 */ 116 if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) { 117 struct sctp_transport *transport; 118 119 /* Find which transport's congestion variables 120 * need to be adjusted. 121 */ 122 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn); 123 124 /* Update the congestion variables. */ 125 if (transport) 126 sctp_transport_lower_cwnd(transport, 127 SCTP_LOWER_CWND_ECNE); 128 asoc->last_cwr_tsn = lowest_tsn; 129 } 130 131 /* Always try to quiet the other end. In case of lost CWR, 132 * resend last_cwr_tsn. 133 */ 134 repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk); 135 136 /* If we run out of memory, it will look like a lost CWR. We'll 137 * get back in sync eventually. 138 */ 139 return repl; 140 } 141 142 /* Helper function to do delayed processing of ECN CWR chunk. */ 143 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc, 144 __u32 lowest_tsn) 145 { 146 /* Turn off ECNE getting auto-prepended to every outgoing 147 * packet 148 */ 149 asoc->need_ecne = 0; 150 } 151 152 /* Generate SACK if necessary. We call this at the end of a packet. */ 153 static int sctp_gen_sack(struct sctp_association *asoc, int force, 154 sctp_cmd_seq_t *commands) 155 { 156 __u32 ctsn, max_tsn_seen; 157 struct sctp_chunk *sack; 158 struct sctp_transport *trans = asoc->peer.last_data_from; 159 int error = 0; 160 161 if (force || 162 (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) || 163 (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE))) 164 asoc->peer.sack_needed = 1; 165 166 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 167 max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map); 168 169 /* From 12.2 Parameters necessary per association (i.e. the TCB): 170 * 171 * Ack State : This flag indicates if the next received packet 172 * : is to be responded to with a SACK. ... 173 * : When DATA chunks are out of order, SACK's 174 * : are not delayed (see Section 6). 175 * 176 * [This is actually not mentioned in Section 6, but we 177 * implement it here anyway. --piggy] 178 */ 179 if (max_tsn_seen != ctsn) 180 asoc->peer.sack_needed = 1; 181 182 /* From 6.2 Acknowledgement on Reception of DATA Chunks: 183 * 184 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, 185 * an acknowledgement SHOULD be generated for at least every 186 * second packet (not every second DATA chunk) received, and 187 * SHOULD be generated within 200 ms of the arrival of any 188 * unacknowledged DATA chunk. ... 189 */ 190 if (!asoc->peer.sack_needed) { 191 asoc->peer.sack_cnt++; 192 193 /* Set the SACK delay timeout based on the 194 * SACK delay for the last transport 195 * data was received from, or the default 196 * for the association. 197 */ 198 if (trans) { 199 /* We will need a SACK for the next packet. */ 200 if (asoc->peer.sack_cnt >= trans->sackfreq - 1) 201 asoc->peer.sack_needed = 1; 202 203 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = 204 trans->sackdelay; 205 } else { 206 /* We will need a SACK for the next packet. */ 207 if (asoc->peer.sack_cnt >= asoc->sackfreq - 1) 208 asoc->peer.sack_needed = 1; 209 210 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = 211 asoc->sackdelay; 212 } 213 214 /* Restart the SACK timer. */ 215 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, 216 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK)); 217 } else { 218 asoc->a_rwnd = asoc->rwnd; 219 sack = sctp_make_sack(asoc); 220 if (!sack) 221 goto nomem; 222 223 asoc->peer.sack_needed = 0; 224 asoc->peer.sack_cnt = 0; 225 226 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack)); 227 228 /* Stop the SACK timer. */ 229 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, 230 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK)); 231 } 232 233 return error; 234 nomem: 235 error = -ENOMEM; 236 return error; 237 } 238 239 /* When the T3-RTX timer expires, it calls this function to create the 240 * relevant state machine event. 241 */ 242 void sctp_generate_t3_rtx_event(unsigned long peer) 243 { 244 int error; 245 struct sctp_transport *transport = (struct sctp_transport *) peer; 246 struct sctp_association *asoc = transport->asoc; 247 struct sock *sk = asoc->base.sk; 248 struct net *net = sock_net(sk); 249 250 /* Check whether a task is in the sock. */ 251 252 bh_lock_sock(sk); 253 if (sock_owned_by_user(sk)) { 254 pr_debug("%s: sock is busy\n", __func__); 255 256 /* Try again later. */ 257 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20))) 258 sctp_transport_hold(transport); 259 goto out_unlock; 260 } 261 262 /* Is this transport really dead and just waiting around for 263 * the timer to let go of the reference? 264 */ 265 if (transport->dead) 266 goto out_unlock; 267 268 /* Run through the state machine. */ 269 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT, 270 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX), 271 asoc->state, 272 asoc->ep, asoc, 273 transport, GFP_ATOMIC); 274 275 if (error) 276 sk->sk_err = -error; 277 278 out_unlock: 279 bh_unlock_sock(sk); 280 sctp_transport_put(transport); 281 } 282 283 /* This is a sa interface for producing timeout events. It works 284 * for timeouts which use the association as their parameter. 285 */ 286 static void sctp_generate_timeout_event(struct sctp_association *asoc, 287 sctp_event_timeout_t timeout_type) 288 { 289 struct sock *sk = asoc->base.sk; 290 struct net *net = sock_net(sk); 291 int error = 0; 292 293 bh_lock_sock(sk); 294 if (sock_owned_by_user(sk)) { 295 pr_debug("%s: sock is busy: timer %d\n", __func__, 296 timeout_type); 297 298 /* Try again later. */ 299 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20))) 300 sctp_association_hold(asoc); 301 goto out_unlock; 302 } 303 304 /* Is this association really dead and just waiting around for 305 * the timer to let go of the reference? 306 */ 307 if (asoc->base.dead) 308 goto out_unlock; 309 310 /* Run through the state machine. */ 311 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT, 312 SCTP_ST_TIMEOUT(timeout_type), 313 asoc->state, asoc->ep, asoc, 314 (void *)timeout_type, GFP_ATOMIC); 315 316 if (error) 317 sk->sk_err = -error; 318 319 out_unlock: 320 bh_unlock_sock(sk); 321 sctp_association_put(asoc); 322 } 323 324 static void sctp_generate_t1_cookie_event(unsigned long data) 325 { 326 struct sctp_association *asoc = (struct sctp_association *) data; 327 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE); 328 } 329 330 static void sctp_generate_t1_init_event(unsigned long data) 331 { 332 struct sctp_association *asoc = (struct sctp_association *) data; 333 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT); 334 } 335 336 static void sctp_generate_t2_shutdown_event(unsigned long data) 337 { 338 struct sctp_association *asoc = (struct sctp_association *) data; 339 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN); 340 } 341 342 static void sctp_generate_t4_rto_event(unsigned long data) 343 { 344 struct sctp_association *asoc = (struct sctp_association *) data; 345 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO); 346 } 347 348 static void sctp_generate_t5_shutdown_guard_event(unsigned long data) 349 { 350 struct sctp_association *asoc = (struct sctp_association *)data; 351 sctp_generate_timeout_event(asoc, 352 SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD); 353 354 } /* sctp_generate_t5_shutdown_guard_event() */ 355 356 static void sctp_generate_autoclose_event(unsigned long data) 357 { 358 struct sctp_association *asoc = (struct sctp_association *) data; 359 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE); 360 } 361 362 /* Generate a heart beat event. If the sock is busy, reschedule. Make 363 * sure that the transport is still valid. 364 */ 365 void sctp_generate_heartbeat_event(unsigned long data) 366 { 367 int error = 0; 368 struct sctp_transport *transport = (struct sctp_transport *) data; 369 struct sctp_association *asoc = transport->asoc; 370 struct sock *sk = asoc->base.sk; 371 struct net *net = sock_net(sk); 372 373 bh_lock_sock(sk); 374 if (sock_owned_by_user(sk)) { 375 pr_debug("%s: sock is busy\n", __func__); 376 377 /* Try again later. */ 378 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20))) 379 sctp_transport_hold(transport); 380 goto out_unlock; 381 } 382 383 /* Is this structure just waiting around for us to actually 384 * get destroyed? 385 */ 386 if (transport->dead) 387 goto out_unlock; 388 389 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT, 390 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT), 391 asoc->state, asoc->ep, asoc, 392 transport, GFP_ATOMIC); 393 394 if (error) 395 sk->sk_err = -error; 396 397 out_unlock: 398 bh_unlock_sock(sk); 399 sctp_transport_put(transport); 400 } 401 402 /* Handle the timeout of the ICMP protocol unreachable timer. Trigger 403 * the correct state machine transition that will close the association. 404 */ 405 void sctp_generate_proto_unreach_event(unsigned long data) 406 { 407 struct sctp_transport *transport = (struct sctp_transport *) data; 408 struct sctp_association *asoc = transport->asoc; 409 struct sock *sk = asoc->base.sk; 410 struct net *net = sock_net(sk); 411 412 bh_lock_sock(sk); 413 if (sock_owned_by_user(sk)) { 414 pr_debug("%s: sock is busy\n", __func__); 415 416 /* Try again later. */ 417 if (!mod_timer(&transport->proto_unreach_timer, 418 jiffies + (HZ/20))) 419 sctp_association_hold(asoc); 420 goto out_unlock; 421 } 422 423 /* Is this structure just waiting around for us to actually 424 * get destroyed? 425 */ 426 if (asoc->base.dead) 427 goto out_unlock; 428 429 sctp_do_sm(net, SCTP_EVENT_T_OTHER, 430 SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH), 431 asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC); 432 433 out_unlock: 434 bh_unlock_sock(sk); 435 sctp_association_put(asoc); 436 } 437 438 439 /* Inject a SACK Timeout event into the state machine. */ 440 static void sctp_generate_sack_event(unsigned long data) 441 { 442 struct sctp_association *asoc = (struct sctp_association *) data; 443 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK); 444 } 445 446 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = { 447 NULL, 448 sctp_generate_t1_cookie_event, 449 sctp_generate_t1_init_event, 450 sctp_generate_t2_shutdown_event, 451 NULL, 452 sctp_generate_t4_rto_event, 453 sctp_generate_t5_shutdown_guard_event, 454 NULL, 455 sctp_generate_sack_event, 456 sctp_generate_autoclose_event, 457 }; 458 459 460 /* RFC 2960 8.2 Path Failure Detection 461 * 462 * When its peer endpoint is multi-homed, an endpoint should keep a 463 * error counter for each of the destination transport addresses of the 464 * peer endpoint. 465 * 466 * Each time the T3-rtx timer expires on any address, or when a 467 * HEARTBEAT sent to an idle address is not acknowledged within a RTO, 468 * the error counter of that destination address will be incremented. 469 * When the value in the error counter exceeds the protocol parameter 470 * 'Path.Max.Retrans' of that destination address, the endpoint should 471 * mark the destination transport address as inactive, and a 472 * notification SHOULD be sent to the upper layer. 473 * 474 */ 475 static void sctp_do_8_2_transport_strike(sctp_cmd_seq_t *commands, 476 struct sctp_association *asoc, 477 struct sctp_transport *transport, 478 int is_hb) 479 { 480 struct net *net = sock_net(asoc->base.sk); 481 482 /* The check for association's overall error counter exceeding the 483 * threshold is done in the state function. 484 */ 485 /* We are here due to a timer expiration. If the timer was 486 * not a HEARTBEAT, then normal error tracking is done. 487 * If the timer was a heartbeat, we only increment error counts 488 * when we already have an outstanding HEARTBEAT that has not 489 * been acknowledged. 490 * Additionally, some tranport states inhibit error increments. 491 */ 492 if (!is_hb) { 493 asoc->overall_error_count++; 494 if (transport->state != SCTP_INACTIVE) 495 transport->error_count++; 496 } else if (transport->hb_sent) { 497 if (transport->state != SCTP_UNCONFIRMED) 498 asoc->overall_error_count++; 499 if (transport->state != SCTP_INACTIVE) 500 transport->error_count++; 501 } 502 503 /* If the transport error count is greater than the pf_retrans 504 * threshold, and less than pathmaxrtx, and if the current state 505 * is SCTP_ACTIVE, then mark this transport as Partially Failed, 506 * see SCTP Quick Failover Draft, section 5.1 507 */ 508 if (net->sctp.pf_enable && 509 (transport->state == SCTP_ACTIVE) && 510 (asoc->pf_retrans < transport->pathmaxrxt) && 511 (transport->error_count > asoc->pf_retrans)) { 512 513 sctp_assoc_control_transport(asoc, transport, 514 SCTP_TRANSPORT_PF, 515 0); 516 517 /* Update the hb timer to resend a heartbeat every rto */ 518 sctp_cmd_hb_timer_update(commands, transport); 519 } 520 521 if (transport->state != SCTP_INACTIVE && 522 (transport->error_count > transport->pathmaxrxt)) { 523 pr_debug("%s: association:%p transport addr:%pISpc failed\n", 524 __func__, asoc, &transport->ipaddr.sa); 525 526 sctp_assoc_control_transport(asoc, transport, 527 SCTP_TRANSPORT_DOWN, 528 SCTP_FAILED_THRESHOLD); 529 } 530 531 /* E2) For the destination address for which the timer 532 * expires, set RTO <- RTO * 2 ("back off the timer"). The 533 * maximum value discussed in rule C7 above (RTO.max) may be 534 * used to provide an upper bound to this doubling operation. 535 * 536 * Special Case: the first HB doesn't trigger exponential backoff. 537 * The first unacknowledged HB triggers it. We do this with a flag 538 * that indicates that we have an outstanding HB. 539 */ 540 if (!is_hb || transport->hb_sent) { 541 transport->rto = min((transport->rto * 2), transport->asoc->rto_max); 542 sctp_max_rto(asoc, transport); 543 } 544 } 545 546 /* Worker routine to handle INIT command failure. */ 547 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands, 548 struct sctp_association *asoc, 549 unsigned int error) 550 { 551 struct sctp_ulpevent *event; 552 553 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_CANT_STR_ASSOC, 554 (__u16)error, 0, 0, NULL, 555 GFP_ATOMIC); 556 557 if (event) 558 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, 559 SCTP_ULPEVENT(event)); 560 561 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, 562 SCTP_STATE(SCTP_STATE_CLOSED)); 563 564 /* SEND_FAILED sent later when cleaning up the association. */ 565 asoc->outqueue.error = error; 566 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); 567 } 568 569 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED. */ 570 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands, 571 struct sctp_association *asoc, 572 sctp_event_t event_type, 573 sctp_subtype_t subtype, 574 struct sctp_chunk *chunk, 575 unsigned int error) 576 { 577 struct sctp_ulpevent *event; 578 struct sctp_chunk *abort; 579 /* Cancel any partial delivery in progress. */ 580 sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC); 581 582 if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT) 583 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST, 584 (__u16)error, 0, 0, chunk, 585 GFP_ATOMIC); 586 else 587 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST, 588 (__u16)error, 0, 0, NULL, 589 GFP_ATOMIC); 590 if (event) 591 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, 592 SCTP_ULPEVENT(event)); 593 594 if (asoc->overall_error_count >= asoc->max_retrans) { 595 abort = sctp_make_violation_max_retrans(asoc, chunk); 596 if (abort) 597 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, 598 SCTP_CHUNK(abort)); 599 } 600 601 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, 602 SCTP_STATE(SCTP_STATE_CLOSED)); 603 604 /* SEND_FAILED sent later when cleaning up the association. */ 605 asoc->outqueue.error = error; 606 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); 607 } 608 609 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT 610 * inside the cookie. In reality, this is only used for INIT-ACK processing 611 * since all other cases use "temporary" associations and can do all 612 * their work in statefuns directly. 613 */ 614 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands, 615 struct sctp_association *asoc, 616 struct sctp_chunk *chunk, 617 sctp_init_chunk_t *peer_init, 618 gfp_t gfp) 619 { 620 int error; 621 622 /* We only process the init as a sideeffect in a single 623 * case. This is when we process the INIT-ACK. If we 624 * fail during INIT processing (due to malloc problems), 625 * just return the error and stop processing the stack. 626 */ 627 if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp)) 628 error = -ENOMEM; 629 else 630 error = 0; 631 632 return error; 633 } 634 635 /* Helper function to break out starting up of heartbeat timers. */ 636 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds, 637 struct sctp_association *asoc) 638 { 639 struct sctp_transport *t; 640 641 /* Start a heartbeat timer for each transport on the association. 642 * hold a reference on the transport to make sure none of 643 * the needed data structures go away. 644 */ 645 list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) { 646 647 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t))) 648 sctp_transport_hold(t); 649 } 650 } 651 652 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds, 653 struct sctp_association *asoc) 654 { 655 struct sctp_transport *t; 656 657 /* Stop all heartbeat timers. */ 658 659 list_for_each_entry(t, &asoc->peer.transport_addr_list, 660 transports) { 661 if (del_timer(&t->hb_timer)) 662 sctp_transport_put(t); 663 } 664 } 665 666 /* Helper function to stop any pending T3-RTX timers */ 667 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds, 668 struct sctp_association *asoc) 669 { 670 struct sctp_transport *t; 671 672 list_for_each_entry(t, &asoc->peer.transport_addr_list, 673 transports) { 674 if (del_timer(&t->T3_rtx_timer)) 675 sctp_transport_put(t); 676 } 677 } 678 679 680 /* Helper function to update the heartbeat timer. */ 681 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds, 682 struct sctp_transport *t) 683 { 684 /* Update the heartbeat timer. */ 685 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t))) 686 sctp_transport_hold(t); 687 } 688 689 /* Helper function to handle the reception of an HEARTBEAT ACK. */ 690 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds, 691 struct sctp_association *asoc, 692 struct sctp_transport *t, 693 struct sctp_chunk *chunk) 694 { 695 sctp_sender_hb_info_t *hbinfo; 696 int was_unconfirmed = 0; 697 698 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the 699 * HEARTBEAT should clear the error counter of the destination 700 * transport address to which the HEARTBEAT was sent. 701 */ 702 t->error_count = 0; 703 704 /* 705 * Although RFC4960 specifies that the overall error count must 706 * be cleared when a HEARTBEAT ACK is received, we make an 707 * exception while in SHUTDOWN PENDING. If the peer keeps its 708 * window shut forever, we may never be able to transmit our 709 * outstanding data and rely on the retransmission limit be reached 710 * to shutdown the association. 711 */ 712 if (t->asoc->state < SCTP_STATE_SHUTDOWN_PENDING) 713 t->asoc->overall_error_count = 0; 714 715 /* Clear the hb_sent flag to signal that we had a good 716 * acknowledgement. 717 */ 718 t->hb_sent = 0; 719 720 /* Mark the destination transport address as active if it is not so 721 * marked. 722 */ 723 if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) { 724 was_unconfirmed = 1; 725 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP, 726 SCTP_HEARTBEAT_SUCCESS); 727 } 728 729 if (t->state == SCTP_PF) 730 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP, 731 SCTP_HEARTBEAT_SUCCESS); 732 733 /* HB-ACK was received for a the proper HB. Consider this 734 * forward progress. 735 */ 736 if (t->dst) 737 dst_confirm(t->dst); 738 739 /* The receiver of the HEARTBEAT ACK should also perform an 740 * RTT measurement for that destination transport address 741 * using the time value carried in the HEARTBEAT ACK chunk. 742 * If the transport's rto_pending variable has been cleared, 743 * it was most likely due to a retransmit. However, we want 744 * to re-enable it to properly update the rto. 745 */ 746 if (t->rto_pending == 0) 747 t->rto_pending = 1; 748 749 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data; 750 sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at)); 751 752 /* Update the heartbeat timer. */ 753 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t))) 754 sctp_transport_hold(t); 755 756 if (was_unconfirmed && asoc->peer.transport_count == 1) 757 sctp_transport_immediate_rtx(t); 758 } 759 760 761 /* Helper function to process the process SACK command. */ 762 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds, 763 struct sctp_association *asoc, 764 struct sctp_chunk *chunk) 765 { 766 int err = 0; 767 768 if (sctp_outq_sack(&asoc->outqueue, chunk)) { 769 struct net *net = sock_net(asoc->base.sk); 770 771 /* There are no more TSNs awaiting SACK. */ 772 err = sctp_do_sm(net, SCTP_EVENT_T_OTHER, 773 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN), 774 asoc->state, asoc->ep, asoc, NULL, 775 GFP_ATOMIC); 776 } 777 778 return err; 779 } 780 781 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set 782 * the transport for a shutdown chunk. 783 */ 784 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds, 785 struct sctp_association *asoc, 786 struct sctp_chunk *chunk) 787 { 788 struct sctp_transport *t; 789 790 if (chunk->transport) 791 t = chunk->transport; 792 else { 793 t = sctp_assoc_choose_alter_transport(asoc, 794 asoc->shutdown_last_sent_to); 795 chunk->transport = t; 796 } 797 asoc->shutdown_last_sent_to = t; 798 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto; 799 } 800 801 /* Helper function to change the state of an association. */ 802 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds, 803 struct sctp_association *asoc, 804 sctp_state_t state) 805 { 806 struct sock *sk = asoc->base.sk; 807 808 asoc->state = state; 809 810 pr_debug("%s: asoc:%p[%s]\n", __func__, asoc, sctp_state_tbl[state]); 811 812 if (sctp_style(sk, TCP)) { 813 /* Change the sk->sk_state of a TCP-style socket that has 814 * successfully completed a connect() call. 815 */ 816 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED)) 817 sk->sk_state = SCTP_SS_ESTABLISHED; 818 819 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */ 820 if (sctp_state(asoc, SHUTDOWN_RECEIVED) && 821 sctp_sstate(sk, ESTABLISHED)) 822 sk->sk_shutdown |= RCV_SHUTDOWN; 823 } 824 825 if (sctp_state(asoc, COOKIE_WAIT)) { 826 /* Reset init timeouts since they may have been 827 * increased due to timer expirations. 828 */ 829 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = 830 asoc->rto_initial; 831 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = 832 asoc->rto_initial; 833 } 834 835 if (sctp_state(asoc, ESTABLISHED) || 836 sctp_state(asoc, CLOSED) || 837 sctp_state(asoc, SHUTDOWN_RECEIVED)) { 838 /* Wake up any processes waiting in the asoc's wait queue in 839 * sctp_wait_for_connect() or sctp_wait_for_sndbuf(). 840 */ 841 if (waitqueue_active(&asoc->wait)) 842 wake_up_interruptible(&asoc->wait); 843 844 /* Wake up any processes waiting in the sk's sleep queue of 845 * a TCP-style or UDP-style peeled-off socket in 846 * sctp_wait_for_accept() or sctp_wait_for_packet(). 847 * For a UDP-style socket, the waiters are woken up by the 848 * notifications. 849 */ 850 if (!sctp_style(sk, UDP)) 851 sk->sk_state_change(sk); 852 } 853 } 854 855 /* Helper function to delete an association. */ 856 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds, 857 struct sctp_association *asoc) 858 { 859 struct sock *sk = asoc->base.sk; 860 861 /* If it is a non-temporary association belonging to a TCP-style 862 * listening socket that is not closed, do not free it so that accept() 863 * can pick it up later. 864 */ 865 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) && 866 (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK)) 867 return; 868 869 sctp_association_free(asoc); 870 } 871 872 /* 873 * ADDIP Section 4.1 ASCONF Chunk Procedures 874 * A4) Start a T-4 RTO timer, using the RTO value of the selected 875 * destination address (we use active path instead of primary path just 876 * because primary path may be inactive. 877 */ 878 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds, 879 struct sctp_association *asoc, 880 struct sctp_chunk *chunk) 881 { 882 struct sctp_transport *t; 883 884 t = sctp_assoc_choose_alter_transport(asoc, chunk->transport); 885 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto; 886 chunk->transport = t; 887 } 888 889 /* Process an incoming Operation Error Chunk. */ 890 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds, 891 struct sctp_association *asoc, 892 struct sctp_chunk *chunk) 893 { 894 struct sctp_errhdr *err_hdr; 895 struct sctp_ulpevent *ev; 896 897 while (chunk->chunk_end > chunk->skb->data) { 898 err_hdr = (struct sctp_errhdr *)(chunk->skb->data); 899 900 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0, 901 GFP_ATOMIC); 902 if (!ev) 903 return; 904 905 sctp_ulpq_tail_event(&asoc->ulpq, ev); 906 907 switch (err_hdr->cause) { 908 case SCTP_ERROR_UNKNOWN_CHUNK: 909 { 910 sctp_chunkhdr_t *unk_chunk_hdr; 911 912 unk_chunk_hdr = (sctp_chunkhdr_t *)err_hdr->variable; 913 switch (unk_chunk_hdr->type) { 914 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with 915 * an ERROR chunk reporting that it did not recognized 916 * the ASCONF chunk type, the sender of the ASCONF MUST 917 * NOT send any further ASCONF chunks and MUST stop its 918 * T-4 timer. 919 */ 920 case SCTP_CID_ASCONF: 921 if (asoc->peer.asconf_capable == 0) 922 break; 923 924 asoc->peer.asconf_capable = 0; 925 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP, 926 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); 927 break; 928 default: 929 break; 930 } 931 break; 932 } 933 default: 934 break; 935 } 936 } 937 } 938 939 /* Process variable FWDTSN chunk information. */ 940 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq, 941 struct sctp_chunk *chunk) 942 { 943 struct sctp_fwdtsn_skip *skip; 944 /* Walk through all the skipped SSNs */ 945 sctp_walk_fwdtsn(skip, chunk) { 946 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn)); 947 } 948 } 949 950 /* Helper function to remove the association non-primary peer 951 * transports. 952 */ 953 static void sctp_cmd_del_non_primary(struct sctp_association *asoc) 954 { 955 struct sctp_transport *t; 956 struct list_head *pos; 957 struct list_head *temp; 958 959 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 960 t = list_entry(pos, struct sctp_transport, transports); 961 if (!sctp_cmp_addr_exact(&t->ipaddr, 962 &asoc->peer.primary_addr)) { 963 sctp_assoc_rm_peer(asoc, t); 964 } 965 } 966 } 967 968 /* Helper function to set sk_err on a 1-1 style socket. */ 969 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error) 970 { 971 struct sock *sk = asoc->base.sk; 972 973 if (!sctp_style(sk, UDP)) 974 sk->sk_err = error; 975 } 976 977 /* Helper function to generate an association change event */ 978 static void sctp_cmd_assoc_change(sctp_cmd_seq_t *commands, 979 struct sctp_association *asoc, 980 u8 state) 981 { 982 struct sctp_ulpevent *ev; 983 984 ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0, 985 asoc->c.sinit_num_ostreams, 986 asoc->c.sinit_max_instreams, 987 NULL, GFP_ATOMIC); 988 if (ev) 989 sctp_ulpq_tail_event(&asoc->ulpq, ev); 990 } 991 992 /* Helper function to generate an adaptation indication event */ 993 static void sctp_cmd_adaptation_ind(sctp_cmd_seq_t *commands, 994 struct sctp_association *asoc) 995 { 996 struct sctp_ulpevent *ev; 997 998 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC); 999 1000 if (ev) 1001 sctp_ulpq_tail_event(&asoc->ulpq, ev); 1002 } 1003 1004 1005 static void sctp_cmd_t1_timer_update(struct sctp_association *asoc, 1006 sctp_event_timeout_t timer, 1007 char *name) 1008 { 1009 struct sctp_transport *t; 1010 1011 t = asoc->init_last_sent_to; 1012 asoc->init_err_counter++; 1013 1014 if (t->init_sent_count > (asoc->init_cycle + 1)) { 1015 asoc->timeouts[timer] *= 2; 1016 if (asoc->timeouts[timer] > asoc->max_init_timeo) { 1017 asoc->timeouts[timer] = asoc->max_init_timeo; 1018 } 1019 asoc->init_cycle++; 1020 1021 pr_debug("%s: T1[%s] timeout adjustment init_err_counter:%d" 1022 " cycle:%d timeout:%ld\n", __func__, name, 1023 asoc->init_err_counter, asoc->init_cycle, 1024 asoc->timeouts[timer]); 1025 } 1026 1027 } 1028 1029 /* Send the whole message, chunk by chunk, to the outqueue. 1030 * This way the whole message is queued up and bundling if 1031 * encouraged for small fragments. 1032 */ 1033 static int sctp_cmd_send_msg(struct sctp_association *asoc, 1034 struct sctp_datamsg *msg) 1035 { 1036 struct sctp_chunk *chunk; 1037 int error = 0; 1038 1039 list_for_each_entry(chunk, &msg->chunks, frag_list) { 1040 error = sctp_outq_tail(&asoc->outqueue, chunk); 1041 if (error) 1042 break; 1043 } 1044 1045 return error; 1046 } 1047 1048 1049 /* Sent the next ASCONF packet currently stored in the association. 1050 * This happens after the ASCONF_ACK was succeffully processed. 1051 */ 1052 static void sctp_cmd_send_asconf(struct sctp_association *asoc) 1053 { 1054 struct net *net = sock_net(asoc->base.sk); 1055 1056 /* Send the next asconf chunk from the addip chunk 1057 * queue. 1058 */ 1059 if (!list_empty(&asoc->addip_chunk_list)) { 1060 struct list_head *entry = asoc->addip_chunk_list.next; 1061 struct sctp_chunk *asconf = list_entry(entry, 1062 struct sctp_chunk, list); 1063 list_del_init(entry); 1064 1065 /* Hold the chunk until an ASCONF_ACK is received. */ 1066 sctp_chunk_hold(asconf); 1067 if (sctp_primitive_ASCONF(net, asoc, asconf)) 1068 sctp_chunk_free(asconf); 1069 else 1070 asoc->addip_last_asconf = asconf; 1071 } 1072 } 1073 1074 1075 /* These three macros allow us to pull the debugging code out of the 1076 * main flow of sctp_do_sm() to keep attention focused on the real 1077 * functionality there. 1078 */ 1079 #define debug_pre_sfn() \ 1080 pr_debug("%s[pre-fn]: ep:%p, %s, %s, asoc:%p[%s], %s\n", __func__, \ 1081 ep, sctp_evttype_tbl[event_type], (*debug_fn)(subtype), \ 1082 asoc, sctp_state_tbl[state], state_fn->name) 1083 1084 #define debug_post_sfn() \ 1085 pr_debug("%s[post-fn]: asoc:%p, status:%s\n", __func__, asoc, \ 1086 sctp_status_tbl[status]) 1087 1088 #define debug_post_sfx() \ 1089 pr_debug("%s[post-sfx]: error:%d, asoc:%p[%s]\n", __func__, error, \ 1090 asoc, sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \ 1091 sctp_assoc2id(asoc))) ? asoc->state : SCTP_STATE_CLOSED]) 1092 1093 /* 1094 * This is the master state machine processing function. 1095 * 1096 * If you want to understand all of lksctp, this is a 1097 * good place to start. 1098 */ 1099 int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype, 1100 sctp_state_t state, 1101 struct sctp_endpoint *ep, 1102 struct sctp_association *asoc, 1103 void *event_arg, 1104 gfp_t gfp) 1105 { 1106 sctp_cmd_seq_t commands; 1107 const sctp_sm_table_entry_t *state_fn; 1108 sctp_disposition_t status; 1109 int error = 0; 1110 typedef const char *(printfn_t)(sctp_subtype_t); 1111 static printfn_t *table[] = { 1112 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname, 1113 }; 1114 printfn_t *debug_fn __attribute__ ((unused)) = table[event_type]; 1115 1116 /* Look up the state function, run it, and then process the 1117 * side effects. These three steps are the heart of lksctp. 1118 */ 1119 state_fn = sctp_sm_lookup_event(net, event_type, state, subtype); 1120 1121 sctp_init_cmd_seq(&commands); 1122 1123 debug_pre_sfn(); 1124 status = state_fn->fn(net, ep, asoc, subtype, event_arg, &commands); 1125 debug_post_sfn(); 1126 1127 error = sctp_side_effects(event_type, subtype, state, 1128 ep, &asoc, event_arg, status, 1129 &commands, gfp); 1130 debug_post_sfx(); 1131 1132 return error; 1133 } 1134 1135 /***************************************************************** 1136 * This the master state function side effect processing function. 1137 *****************************************************************/ 1138 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype, 1139 sctp_state_t state, 1140 struct sctp_endpoint *ep, 1141 struct sctp_association **asoc, 1142 void *event_arg, 1143 sctp_disposition_t status, 1144 sctp_cmd_seq_t *commands, 1145 gfp_t gfp) 1146 { 1147 int error; 1148 1149 /* FIXME - Most of the dispositions left today would be categorized 1150 * as "exceptional" dispositions. For those dispositions, it 1151 * may not be proper to run through any of the commands at all. 1152 * For example, the command interpreter might be run only with 1153 * disposition SCTP_DISPOSITION_CONSUME. 1154 */ 1155 if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state, 1156 ep, *asoc, 1157 event_arg, status, 1158 commands, gfp))) 1159 goto bail; 1160 1161 switch (status) { 1162 case SCTP_DISPOSITION_DISCARD: 1163 pr_debug("%s: ignored sctp protocol event - state:%d, " 1164 "event_type:%d, event_id:%d\n", __func__, state, 1165 event_type, subtype.chunk); 1166 break; 1167 1168 case SCTP_DISPOSITION_NOMEM: 1169 /* We ran out of memory, so we need to discard this 1170 * packet. 1171 */ 1172 /* BUG--we should now recover some memory, probably by 1173 * reneging... 1174 */ 1175 error = -ENOMEM; 1176 break; 1177 1178 case SCTP_DISPOSITION_DELETE_TCB: 1179 case SCTP_DISPOSITION_ABORT: 1180 /* This should now be a command. */ 1181 *asoc = NULL; 1182 break; 1183 1184 case SCTP_DISPOSITION_CONSUME: 1185 /* 1186 * We should no longer have much work to do here as the 1187 * real work has been done as explicit commands above. 1188 */ 1189 break; 1190 1191 case SCTP_DISPOSITION_VIOLATION: 1192 net_err_ratelimited("protocol violation state %d chunkid %d\n", 1193 state, subtype.chunk); 1194 break; 1195 1196 case SCTP_DISPOSITION_NOT_IMPL: 1197 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n", 1198 state, event_type, subtype.chunk); 1199 break; 1200 1201 case SCTP_DISPOSITION_BUG: 1202 pr_err("bug in state %d, event_type %d, event_id %d\n", 1203 state, event_type, subtype.chunk); 1204 BUG(); 1205 break; 1206 1207 default: 1208 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n", 1209 status, state, event_type, subtype.chunk); 1210 BUG(); 1211 break; 1212 } 1213 1214 bail: 1215 return error; 1216 } 1217 1218 /******************************************************************** 1219 * 2nd Level Abstractions 1220 ********************************************************************/ 1221 1222 /* This is the side-effect interpreter. */ 1223 static int sctp_cmd_interpreter(sctp_event_t event_type, 1224 sctp_subtype_t subtype, 1225 sctp_state_t state, 1226 struct sctp_endpoint *ep, 1227 struct sctp_association *asoc, 1228 void *event_arg, 1229 sctp_disposition_t status, 1230 sctp_cmd_seq_t *commands, 1231 gfp_t gfp) 1232 { 1233 int error = 0; 1234 int force; 1235 sctp_cmd_t *cmd; 1236 struct sctp_chunk *new_obj; 1237 struct sctp_chunk *chunk = NULL; 1238 struct sctp_packet *packet; 1239 struct timer_list *timer; 1240 unsigned long timeout; 1241 struct sctp_transport *t; 1242 struct sctp_sackhdr sackh; 1243 int local_cork = 0; 1244 1245 if (SCTP_EVENT_T_TIMEOUT != event_type) 1246 chunk = event_arg; 1247 1248 /* Note: This whole file is a huge candidate for rework. 1249 * For example, each command could either have its own handler, so 1250 * the loop would look like: 1251 * while (cmds) 1252 * cmd->handle(x, y, z) 1253 * --jgrimm 1254 */ 1255 while (NULL != (cmd = sctp_next_cmd(commands))) { 1256 switch (cmd->verb) { 1257 case SCTP_CMD_NOP: 1258 /* Do nothing. */ 1259 break; 1260 1261 case SCTP_CMD_NEW_ASOC: 1262 /* Register a new association. */ 1263 if (local_cork) { 1264 sctp_outq_uncork(&asoc->outqueue); 1265 local_cork = 0; 1266 } 1267 1268 /* Register with the endpoint. */ 1269 asoc = cmd->obj.asoc; 1270 BUG_ON(asoc->peer.primary_path == NULL); 1271 sctp_endpoint_add_asoc(ep, asoc); 1272 break; 1273 1274 case SCTP_CMD_UPDATE_ASSOC: 1275 sctp_assoc_update(asoc, cmd->obj.asoc); 1276 break; 1277 1278 case SCTP_CMD_PURGE_OUTQUEUE: 1279 sctp_outq_teardown(&asoc->outqueue); 1280 break; 1281 1282 case SCTP_CMD_DELETE_TCB: 1283 if (local_cork) { 1284 sctp_outq_uncork(&asoc->outqueue); 1285 local_cork = 0; 1286 } 1287 /* Delete the current association. */ 1288 sctp_cmd_delete_tcb(commands, asoc); 1289 asoc = NULL; 1290 break; 1291 1292 case SCTP_CMD_NEW_STATE: 1293 /* Enter a new state. */ 1294 sctp_cmd_new_state(commands, asoc, cmd->obj.state); 1295 break; 1296 1297 case SCTP_CMD_REPORT_TSN: 1298 /* Record the arrival of a TSN. */ 1299 error = sctp_tsnmap_mark(&asoc->peer.tsn_map, 1300 cmd->obj.u32, NULL); 1301 break; 1302 1303 case SCTP_CMD_REPORT_FWDTSN: 1304 /* Move the Cumulattive TSN Ack ahead. */ 1305 sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32); 1306 1307 /* purge the fragmentation queue */ 1308 sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32); 1309 1310 /* Abort any in progress partial delivery. */ 1311 sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC); 1312 break; 1313 1314 case SCTP_CMD_PROCESS_FWDTSN: 1315 sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.chunk); 1316 break; 1317 1318 case SCTP_CMD_GEN_SACK: 1319 /* Generate a Selective ACK. 1320 * The argument tells us whether to just count 1321 * the packet and MAYBE generate a SACK, or 1322 * force a SACK out. 1323 */ 1324 force = cmd->obj.i32; 1325 error = sctp_gen_sack(asoc, force, commands); 1326 break; 1327 1328 case SCTP_CMD_PROCESS_SACK: 1329 /* Process an inbound SACK. */ 1330 error = sctp_cmd_process_sack(commands, asoc, 1331 cmd->obj.chunk); 1332 break; 1333 1334 case SCTP_CMD_GEN_INIT_ACK: 1335 /* Generate an INIT ACK chunk. */ 1336 new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC, 1337 0); 1338 if (!new_obj) 1339 goto nomem; 1340 1341 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, 1342 SCTP_CHUNK(new_obj)); 1343 break; 1344 1345 case SCTP_CMD_PEER_INIT: 1346 /* Process a unified INIT from the peer. 1347 * Note: Only used during INIT-ACK processing. If 1348 * there is an error just return to the outter 1349 * layer which will bail. 1350 */ 1351 error = sctp_cmd_process_init(commands, asoc, chunk, 1352 cmd->obj.init, gfp); 1353 break; 1354 1355 case SCTP_CMD_GEN_COOKIE_ECHO: 1356 /* Generate a COOKIE ECHO chunk. */ 1357 new_obj = sctp_make_cookie_echo(asoc, chunk); 1358 if (!new_obj) { 1359 if (cmd->obj.chunk) 1360 sctp_chunk_free(cmd->obj.chunk); 1361 goto nomem; 1362 } 1363 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, 1364 SCTP_CHUNK(new_obj)); 1365 1366 /* If there is an ERROR chunk to be sent along with 1367 * the COOKIE_ECHO, send it, too. 1368 */ 1369 if (cmd->obj.chunk) 1370 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, 1371 SCTP_CHUNK(cmd->obj.chunk)); 1372 1373 if (new_obj->transport) { 1374 new_obj->transport->init_sent_count++; 1375 asoc->init_last_sent_to = new_obj->transport; 1376 } 1377 1378 /* FIXME - Eventually come up with a cleaner way to 1379 * enabling COOKIE-ECHO + DATA bundling during 1380 * multihoming stale cookie scenarios, the following 1381 * command plays with asoc->peer.retran_path to 1382 * avoid the problem of sending the COOKIE-ECHO and 1383 * DATA in different paths, which could result 1384 * in the association being ABORTed if the DATA chunk 1385 * is processed first by the server. Checking the 1386 * init error counter simply causes this command 1387 * to be executed only during failed attempts of 1388 * association establishment. 1389 */ 1390 if ((asoc->peer.retran_path != 1391 asoc->peer.primary_path) && 1392 (asoc->init_err_counter > 0)) { 1393 sctp_add_cmd_sf(commands, 1394 SCTP_CMD_FORCE_PRIM_RETRAN, 1395 SCTP_NULL()); 1396 } 1397 1398 break; 1399 1400 case SCTP_CMD_GEN_SHUTDOWN: 1401 /* Generate SHUTDOWN when in SHUTDOWN_SENT state. 1402 * Reset error counts. 1403 */ 1404 asoc->overall_error_count = 0; 1405 1406 /* Generate a SHUTDOWN chunk. */ 1407 new_obj = sctp_make_shutdown(asoc, chunk); 1408 if (!new_obj) 1409 goto nomem; 1410 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, 1411 SCTP_CHUNK(new_obj)); 1412 break; 1413 1414 case SCTP_CMD_CHUNK_ULP: 1415 /* Send a chunk to the sockets layer. */ 1416 pr_debug("%s: sm_sideff: chunk_up:%p, ulpq:%p\n", 1417 __func__, cmd->obj.chunk, &asoc->ulpq); 1418 1419 sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.chunk, 1420 GFP_ATOMIC); 1421 break; 1422 1423 case SCTP_CMD_EVENT_ULP: 1424 /* Send a notification to the sockets layer. */ 1425 pr_debug("%s: sm_sideff: event_up:%p, ulpq:%p\n", 1426 __func__, cmd->obj.ulpevent, &asoc->ulpq); 1427 1428 sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ulpevent); 1429 break; 1430 1431 case SCTP_CMD_REPLY: 1432 /* If an caller has not already corked, do cork. */ 1433 if (!asoc->outqueue.cork) { 1434 sctp_outq_cork(&asoc->outqueue); 1435 local_cork = 1; 1436 } 1437 /* Send a chunk to our peer. */ 1438 error = sctp_outq_tail(&asoc->outqueue, cmd->obj.chunk); 1439 break; 1440 1441 case SCTP_CMD_SEND_PKT: 1442 /* Send a full packet to our peer. */ 1443 packet = cmd->obj.packet; 1444 sctp_packet_transmit(packet); 1445 sctp_ootb_pkt_free(packet); 1446 break; 1447 1448 case SCTP_CMD_T1_RETRAN: 1449 /* Mark a transport for retransmission. */ 1450 sctp_retransmit(&asoc->outqueue, cmd->obj.transport, 1451 SCTP_RTXR_T1_RTX); 1452 break; 1453 1454 case SCTP_CMD_RETRAN: 1455 /* Mark a transport for retransmission. */ 1456 sctp_retransmit(&asoc->outqueue, cmd->obj.transport, 1457 SCTP_RTXR_T3_RTX); 1458 break; 1459 1460 case SCTP_CMD_ECN_CE: 1461 /* Do delayed CE processing. */ 1462 sctp_do_ecn_ce_work(asoc, cmd->obj.u32); 1463 break; 1464 1465 case SCTP_CMD_ECN_ECNE: 1466 /* Do delayed ECNE processing. */ 1467 new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32, 1468 chunk); 1469 if (new_obj) 1470 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, 1471 SCTP_CHUNK(new_obj)); 1472 break; 1473 1474 case SCTP_CMD_ECN_CWR: 1475 /* Do delayed CWR processing. */ 1476 sctp_do_ecn_cwr_work(asoc, cmd->obj.u32); 1477 break; 1478 1479 case SCTP_CMD_SETUP_T2: 1480 sctp_cmd_setup_t2(commands, asoc, cmd->obj.chunk); 1481 break; 1482 1483 case SCTP_CMD_TIMER_START_ONCE: 1484 timer = &asoc->timers[cmd->obj.to]; 1485 1486 if (timer_pending(timer)) 1487 break; 1488 /* fall through */ 1489 1490 case SCTP_CMD_TIMER_START: 1491 timer = &asoc->timers[cmd->obj.to]; 1492 timeout = asoc->timeouts[cmd->obj.to]; 1493 BUG_ON(!timeout); 1494 1495 timer->expires = jiffies + timeout; 1496 sctp_association_hold(asoc); 1497 add_timer(timer); 1498 break; 1499 1500 case SCTP_CMD_TIMER_RESTART: 1501 timer = &asoc->timers[cmd->obj.to]; 1502 timeout = asoc->timeouts[cmd->obj.to]; 1503 if (!mod_timer(timer, jiffies + timeout)) 1504 sctp_association_hold(asoc); 1505 break; 1506 1507 case SCTP_CMD_TIMER_STOP: 1508 timer = &asoc->timers[cmd->obj.to]; 1509 if (del_timer(timer)) 1510 sctp_association_put(asoc); 1511 break; 1512 1513 case SCTP_CMD_INIT_CHOOSE_TRANSPORT: 1514 chunk = cmd->obj.chunk; 1515 t = sctp_assoc_choose_alter_transport(asoc, 1516 asoc->init_last_sent_to); 1517 asoc->init_last_sent_to = t; 1518 chunk->transport = t; 1519 t->init_sent_count++; 1520 /* Set the new transport as primary */ 1521 sctp_assoc_set_primary(asoc, t); 1522 break; 1523 1524 case SCTP_CMD_INIT_RESTART: 1525 /* Do the needed accounting and updates 1526 * associated with restarting an initialization 1527 * timer. Only multiply the timeout by two if 1528 * all transports have been tried at the current 1529 * timeout. 1530 */ 1531 sctp_cmd_t1_timer_update(asoc, 1532 SCTP_EVENT_TIMEOUT_T1_INIT, 1533 "INIT"); 1534 1535 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, 1536 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); 1537 break; 1538 1539 case SCTP_CMD_COOKIEECHO_RESTART: 1540 /* Do the needed accounting and updates 1541 * associated with restarting an initialization 1542 * timer. Only multiply the timeout by two if 1543 * all transports have been tried at the current 1544 * timeout. 1545 */ 1546 sctp_cmd_t1_timer_update(asoc, 1547 SCTP_EVENT_TIMEOUT_T1_COOKIE, 1548 "COOKIE"); 1549 1550 /* If we've sent any data bundled with 1551 * COOKIE-ECHO we need to resend. 1552 */ 1553 list_for_each_entry(t, &asoc->peer.transport_addr_list, 1554 transports) { 1555 sctp_retransmit_mark(&asoc->outqueue, t, 1556 SCTP_RTXR_T1_RTX); 1557 } 1558 1559 sctp_add_cmd_sf(commands, 1560 SCTP_CMD_TIMER_RESTART, 1561 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); 1562 break; 1563 1564 case SCTP_CMD_INIT_FAILED: 1565 sctp_cmd_init_failed(commands, asoc, cmd->obj.err); 1566 break; 1567 1568 case SCTP_CMD_ASSOC_FAILED: 1569 sctp_cmd_assoc_failed(commands, asoc, event_type, 1570 subtype, chunk, cmd->obj.err); 1571 break; 1572 1573 case SCTP_CMD_INIT_COUNTER_INC: 1574 asoc->init_err_counter++; 1575 break; 1576 1577 case SCTP_CMD_INIT_COUNTER_RESET: 1578 asoc->init_err_counter = 0; 1579 asoc->init_cycle = 0; 1580 list_for_each_entry(t, &asoc->peer.transport_addr_list, 1581 transports) { 1582 t->init_sent_count = 0; 1583 } 1584 break; 1585 1586 case SCTP_CMD_REPORT_DUP: 1587 sctp_tsnmap_mark_dup(&asoc->peer.tsn_map, 1588 cmd->obj.u32); 1589 break; 1590 1591 case SCTP_CMD_REPORT_BAD_TAG: 1592 pr_debug("%s: vtag mismatch!\n", __func__); 1593 break; 1594 1595 case SCTP_CMD_STRIKE: 1596 /* Mark one strike against a transport. */ 1597 sctp_do_8_2_transport_strike(commands, asoc, 1598 cmd->obj.transport, 0); 1599 break; 1600 1601 case SCTP_CMD_TRANSPORT_IDLE: 1602 t = cmd->obj.transport; 1603 sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE); 1604 break; 1605 1606 case SCTP_CMD_TRANSPORT_HB_SENT: 1607 t = cmd->obj.transport; 1608 sctp_do_8_2_transport_strike(commands, asoc, 1609 t, 1); 1610 t->hb_sent = 1; 1611 break; 1612 1613 case SCTP_CMD_TRANSPORT_ON: 1614 t = cmd->obj.transport; 1615 sctp_cmd_transport_on(commands, asoc, t, chunk); 1616 break; 1617 1618 case SCTP_CMD_HB_TIMERS_START: 1619 sctp_cmd_hb_timers_start(commands, asoc); 1620 break; 1621 1622 case SCTP_CMD_HB_TIMER_UPDATE: 1623 t = cmd->obj.transport; 1624 sctp_cmd_hb_timer_update(commands, t); 1625 break; 1626 1627 case SCTP_CMD_HB_TIMERS_STOP: 1628 sctp_cmd_hb_timers_stop(commands, asoc); 1629 break; 1630 1631 case SCTP_CMD_REPORT_ERROR: 1632 error = cmd->obj.error; 1633 break; 1634 1635 case SCTP_CMD_PROCESS_CTSN: 1636 /* Dummy up a SACK for processing. */ 1637 sackh.cum_tsn_ack = cmd->obj.be32; 1638 sackh.a_rwnd = asoc->peer.rwnd + 1639 asoc->outqueue.outstanding_bytes; 1640 sackh.num_gap_ack_blocks = 0; 1641 sackh.num_dup_tsns = 0; 1642 chunk->subh.sack_hdr = &sackh; 1643 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, 1644 SCTP_CHUNK(chunk)); 1645 break; 1646 1647 case SCTP_CMD_DISCARD_PACKET: 1648 /* We need to discard the whole packet. 1649 * Uncork the queue since there might be 1650 * responses pending 1651 */ 1652 chunk->pdiscard = 1; 1653 if (asoc) { 1654 sctp_outq_uncork(&asoc->outqueue); 1655 local_cork = 0; 1656 } 1657 break; 1658 1659 case SCTP_CMD_RTO_PENDING: 1660 t = cmd->obj.transport; 1661 t->rto_pending = 1; 1662 break; 1663 1664 case SCTP_CMD_PART_DELIVER: 1665 sctp_ulpq_partial_delivery(&asoc->ulpq, GFP_ATOMIC); 1666 break; 1667 1668 case SCTP_CMD_RENEGE: 1669 sctp_ulpq_renege(&asoc->ulpq, cmd->obj.chunk, 1670 GFP_ATOMIC); 1671 break; 1672 1673 case SCTP_CMD_SETUP_T4: 1674 sctp_cmd_setup_t4(commands, asoc, cmd->obj.chunk); 1675 break; 1676 1677 case SCTP_CMD_PROCESS_OPERR: 1678 sctp_cmd_process_operr(commands, asoc, chunk); 1679 break; 1680 case SCTP_CMD_CLEAR_INIT_TAG: 1681 asoc->peer.i.init_tag = 0; 1682 break; 1683 case SCTP_CMD_DEL_NON_PRIMARY: 1684 sctp_cmd_del_non_primary(asoc); 1685 break; 1686 case SCTP_CMD_T3_RTX_TIMERS_STOP: 1687 sctp_cmd_t3_rtx_timers_stop(commands, asoc); 1688 break; 1689 case SCTP_CMD_FORCE_PRIM_RETRAN: 1690 t = asoc->peer.retran_path; 1691 asoc->peer.retran_path = asoc->peer.primary_path; 1692 error = sctp_outq_uncork(&asoc->outqueue); 1693 local_cork = 0; 1694 asoc->peer.retran_path = t; 1695 break; 1696 case SCTP_CMD_SET_SK_ERR: 1697 sctp_cmd_set_sk_err(asoc, cmd->obj.error); 1698 break; 1699 case SCTP_CMD_ASSOC_CHANGE: 1700 sctp_cmd_assoc_change(commands, asoc, 1701 cmd->obj.u8); 1702 break; 1703 case SCTP_CMD_ADAPTATION_IND: 1704 sctp_cmd_adaptation_ind(commands, asoc); 1705 break; 1706 1707 case SCTP_CMD_ASSOC_SHKEY: 1708 error = sctp_auth_asoc_init_active_key(asoc, 1709 GFP_ATOMIC); 1710 break; 1711 case SCTP_CMD_UPDATE_INITTAG: 1712 asoc->peer.i.init_tag = cmd->obj.u32; 1713 break; 1714 case SCTP_CMD_SEND_MSG: 1715 if (!asoc->outqueue.cork) { 1716 sctp_outq_cork(&asoc->outqueue); 1717 local_cork = 1; 1718 } 1719 error = sctp_cmd_send_msg(asoc, cmd->obj.msg); 1720 break; 1721 case SCTP_CMD_SEND_NEXT_ASCONF: 1722 sctp_cmd_send_asconf(asoc); 1723 break; 1724 case SCTP_CMD_PURGE_ASCONF_QUEUE: 1725 sctp_asconf_queue_teardown(asoc); 1726 break; 1727 1728 case SCTP_CMD_SET_ASOC: 1729 asoc = cmd->obj.asoc; 1730 break; 1731 1732 default: 1733 pr_warn("Impossible command: %u\n", 1734 cmd->verb); 1735 break; 1736 } 1737 1738 if (error) 1739 break; 1740 } 1741 1742 out: 1743 /* If this is in response to a received chunk, wait until 1744 * we are done with the packet to open the queue so that we don't 1745 * send multiple packets in response to a single request. 1746 */ 1747 if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) { 1748 if (chunk->end_of_packet || chunk->singleton) 1749 error = sctp_outq_uncork(&asoc->outqueue); 1750 } else if (local_cork) 1751 error = sctp_outq_uncork(&asoc->outqueue); 1752 return error; 1753 nomem: 1754 error = -ENOMEM; 1755 goto out; 1756 } 1757 1758