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, 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 * Jon Grimm <jgrimm@austin.ibm.com> 40 * Hui Huang <hui.huang@nokia.com> 41 * Dajiang Zhang <dajiang.zhang@nokia.com> 42 * Daisy Chang <daisyc@us.ibm.com> 43 * Sridhar Samudrala <sri@us.ibm.com> 44 * Ardelle Fan <ardelle.fan@intel.com> 45 * 46 * Any bugs reported given to us we will try to fix... any fixes shared will 47 * be incorporated into the next SCTP release. 48 */ 49 50 #include <linux/skbuff.h> 51 #include <linux/types.h> 52 #include <linux/socket.h> 53 #include <linux/ip.h> 54 #include <linux/gfp.h> 55 #include <net/sock.h> 56 #include <net/sctp/sctp.h> 57 #include <net/sctp/sm.h> 58 59 static int sctp_cmd_interpreter(sctp_event_t event_type, 60 sctp_subtype_t subtype, 61 sctp_state_t state, 62 struct sctp_endpoint *ep, 63 struct sctp_association *asoc, 64 void *event_arg, 65 sctp_disposition_t status, 66 sctp_cmd_seq_t *commands, 67 gfp_t gfp); 68 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype, 69 sctp_state_t state, 70 struct sctp_endpoint *ep, 71 struct sctp_association *asoc, 72 void *event_arg, 73 sctp_disposition_t status, 74 sctp_cmd_seq_t *commands, 75 gfp_t gfp); 76 77 /******************************************************************** 78 * Helper functions 79 ********************************************************************/ 80 81 /* A helper function for delayed processing of INET ECN CE bit. */ 82 static void sctp_do_ecn_ce_work(struct sctp_association *asoc, 83 __u32 lowest_tsn) 84 { 85 /* Save the TSN away for comparison when we receive CWR */ 86 87 asoc->last_ecne_tsn = lowest_tsn; 88 asoc->need_ecne = 1; 89 } 90 91 /* Helper function for delayed processing of SCTP ECNE chunk. */ 92 /* RFC 2960 Appendix A 93 * 94 * RFC 2481 details a specific bit for a sender to send in 95 * the header of its next outbound TCP segment to indicate to 96 * its peer that it has reduced its congestion window. This 97 * is termed the CWR bit. For SCTP the same indication is made 98 * by including the CWR chunk. This chunk contains one data 99 * element, i.e. the TSN number that was sent in the ECNE chunk. 100 * This element represents the lowest TSN number in the datagram 101 * that was originally marked with the CE bit. 102 */ 103 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc, 104 __u32 lowest_tsn, 105 struct sctp_chunk *chunk) 106 { 107 struct sctp_chunk *repl; 108 109 /* Our previously transmitted packet ran into some congestion 110 * so we should take action by reducing cwnd and ssthresh 111 * and then ACK our peer that we we've done so by 112 * sending a CWR. 113 */ 114 115 /* First, try to determine if we want to actually lower 116 * our cwnd variables. Only lower them if the ECNE looks more 117 * recent than the last response. 118 */ 119 if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) { 120 struct sctp_transport *transport; 121 122 /* Find which transport's congestion variables 123 * need to be adjusted. 124 */ 125 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn); 126 127 /* Update the congestion variables. */ 128 if (transport) 129 sctp_transport_lower_cwnd(transport, 130 SCTP_LOWER_CWND_ECNE); 131 asoc->last_cwr_tsn = lowest_tsn; 132 } 133 134 /* Always try to quiet the other end. In case of lost CWR, 135 * resend last_cwr_tsn. 136 */ 137 repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk); 138 139 /* If we run out of memory, it will look like a lost CWR. We'll 140 * get back in sync eventually. 141 */ 142 return repl; 143 } 144 145 /* Helper function to do delayed processing of ECN CWR chunk. */ 146 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc, 147 __u32 lowest_tsn) 148 { 149 /* Turn off ECNE getting auto-prepended to every outgoing 150 * packet 151 */ 152 asoc->need_ecne = 0; 153 } 154 155 /* Generate SACK if necessary. We call this at the end of a packet. */ 156 static int sctp_gen_sack(struct sctp_association *asoc, int force, 157 sctp_cmd_seq_t *commands) 158 { 159 __u32 ctsn, max_tsn_seen; 160 struct sctp_chunk *sack; 161 struct sctp_transport *trans = asoc->peer.last_data_from; 162 int error = 0; 163 164 if (force || 165 (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) || 166 (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE))) 167 asoc->peer.sack_needed = 1; 168 169 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 170 max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map); 171 172 /* From 12.2 Parameters necessary per association (i.e. the TCB): 173 * 174 * Ack State : This flag indicates if the next received packet 175 * : is to be responded to with a SACK. ... 176 * : When DATA chunks are out of order, SACK's 177 * : are not delayed (see Section 6). 178 * 179 * [This is actually not mentioned in Section 6, but we 180 * implement it here anyway. --piggy] 181 */ 182 if (max_tsn_seen != ctsn) 183 asoc->peer.sack_needed = 1; 184 185 /* From 6.2 Acknowledgement on Reception of DATA Chunks: 186 * 187 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, 188 * an acknowledgement SHOULD be generated for at least every 189 * second packet (not every second DATA chunk) received, and 190 * SHOULD be generated within 200 ms of the arrival of any 191 * unacknowledged DATA chunk. ... 192 */ 193 if (!asoc->peer.sack_needed) { 194 asoc->peer.sack_cnt++; 195 196 /* Set the SACK delay timeout based on the 197 * SACK delay for the last transport 198 * data was received from, or the default 199 * for the association. 200 */ 201 if (trans) { 202 /* We will need a SACK for the next packet. */ 203 if (asoc->peer.sack_cnt >= trans->sackfreq - 1) 204 asoc->peer.sack_needed = 1; 205 206 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = 207 trans->sackdelay; 208 } else { 209 /* We will need a SACK for the next packet. */ 210 if (asoc->peer.sack_cnt >= asoc->sackfreq - 1) 211 asoc->peer.sack_needed = 1; 212 213 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = 214 asoc->sackdelay; 215 } 216 217 /* Restart the SACK timer. */ 218 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, 219 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK)); 220 } else { 221 asoc->a_rwnd = asoc->rwnd; 222 sack = sctp_make_sack(asoc); 223 if (!sack) 224 goto nomem; 225 226 asoc->peer.sack_needed = 0; 227 asoc->peer.sack_cnt = 0; 228 229 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack)); 230 231 /* Stop the SACK timer. */ 232 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, 233 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK)); 234 } 235 236 return error; 237 nomem: 238 error = -ENOMEM; 239 return error; 240 } 241 242 /* When the T3-RTX timer expires, it calls this function to create the 243 * relevant state machine event. 244 */ 245 void sctp_generate_t3_rtx_event(unsigned long peer) 246 { 247 int error; 248 struct sctp_transport *transport = (struct sctp_transport *) peer; 249 struct sctp_association *asoc = transport->asoc; 250 251 /* Check whether a task is in the sock. */ 252 253 sctp_bh_lock_sock(asoc->base.sk); 254 if (sock_owned_by_user(asoc->base.sk)) { 255 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__); 256 257 /* Try again later. */ 258 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20))) 259 sctp_transport_hold(transport); 260 goto out_unlock; 261 } 262 263 /* Is this transport really dead and just waiting around for 264 * the timer to let go of the reference? 265 */ 266 if (transport->dead) 267 goto out_unlock; 268 269 /* Run through the state machine. */ 270 error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT, 271 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX), 272 asoc->state, 273 asoc->ep, asoc, 274 transport, GFP_ATOMIC); 275 276 if (error) 277 asoc->base.sk->sk_err = -error; 278 279 out_unlock: 280 sctp_bh_unlock_sock(asoc->base.sk); 281 sctp_transport_put(transport); 282 } 283 284 /* This is a sa interface for producing timeout events. It works 285 * for timeouts which use the association as their parameter. 286 */ 287 static void sctp_generate_timeout_event(struct sctp_association *asoc, 288 sctp_event_timeout_t timeout_type) 289 { 290 int error = 0; 291 292 sctp_bh_lock_sock(asoc->base.sk); 293 if (sock_owned_by_user(asoc->base.sk)) { 294 SCTP_DEBUG_PRINTK("%s:Sock is busy: timer %d\n", 295 __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(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 asoc->base.sk->sk_err = -error; 318 319 out_unlock: 320 sctp_bh_unlock_sock(asoc->base.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; 370 371 sctp_bh_lock_sock(asoc->base.sk); 372 if (sock_owned_by_user(asoc->base.sk)) { 373 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__); 374 375 /* Try again later. */ 376 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20))) 377 sctp_transport_hold(transport); 378 goto out_unlock; 379 } 380 381 /* Is this structure just waiting around for us to actually 382 * get destroyed? 383 */ 384 if (transport->dead) 385 goto out_unlock; 386 387 error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT, 388 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT), 389 asoc->state, asoc->ep, asoc, 390 transport, GFP_ATOMIC); 391 392 if (error) 393 asoc->base.sk->sk_err = -error; 394 395 out_unlock: 396 sctp_bh_unlock_sock(asoc->base.sk); 397 sctp_transport_put(transport); 398 } 399 400 /* Inject a SACK Timeout event into the state machine. */ 401 static void sctp_generate_sack_event(unsigned long data) 402 { 403 struct sctp_association *asoc = (struct sctp_association *) data; 404 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK); 405 } 406 407 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = { 408 NULL, 409 sctp_generate_t1_cookie_event, 410 sctp_generate_t1_init_event, 411 sctp_generate_t2_shutdown_event, 412 NULL, 413 sctp_generate_t4_rto_event, 414 sctp_generate_t5_shutdown_guard_event, 415 NULL, 416 sctp_generate_sack_event, 417 sctp_generate_autoclose_event, 418 }; 419 420 421 /* RFC 2960 8.2 Path Failure Detection 422 * 423 * When its peer endpoint is multi-homed, an endpoint should keep a 424 * error counter for each of the destination transport addresses of the 425 * peer endpoint. 426 * 427 * Each time the T3-rtx timer expires on any address, or when a 428 * HEARTBEAT sent to an idle address is not acknowledged within a RTO, 429 * the error counter of that destination address will be incremented. 430 * When the value in the error counter exceeds the protocol parameter 431 * 'Path.Max.Retrans' of that destination address, the endpoint should 432 * mark the destination transport address as inactive, and a 433 * notification SHOULD be sent to the upper layer. 434 * 435 */ 436 static void sctp_do_8_2_transport_strike(struct sctp_association *asoc, 437 struct sctp_transport *transport, 438 int is_hb) 439 { 440 /* The check for association's overall error counter exceeding the 441 * threshold is done in the state function. 442 */ 443 /* We are here due to a timer expiration. If the timer was 444 * not a HEARTBEAT, then normal error tracking is done. 445 * If the timer was a heartbeat, we only increment error counts 446 * when we already have an outstanding HEARTBEAT that has not 447 * been acknowledged. 448 * Additionaly, some tranport states inhibit error increments. 449 */ 450 if (!is_hb) { 451 asoc->overall_error_count++; 452 if (transport->state != SCTP_INACTIVE) 453 transport->error_count++; 454 } else if (transport->hb_sent) { 455 if (transport->state != SCTP_UNCONFIRMED) 456 asoc->overall_error_count++; 457 if (transport->state != SCTP_INACTIVE) 458 transport->error_count++; 459 } 460 461 if (transport->state != SCTP_INACTIVE && 462 (transport->error_count > transport->pathmaxrxt)) { 463 SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p", 464 " transport IP: port:%d failed.\n", 465 asoc, 466 (&transport->ipaddr), 467 ntohs(transport->ipaddr.v4.sin_port)); 468 sctp_assoc_control_transport(asoc, transport, 469 SCTP_TRANSPORT_DOWN, 470 SCTP_FAILED_THRESHOLD); 471 } 472 473 /* E2) For the destination address for which the timer 474 * expires, set RTO <- RTO * 2 ("back off the timer"). The 475 * maximum value discussed in rule C7 above (RTO.max) may be 476 * used to provide an upper bound to this doubling operation. 477 * 478 * Special Case: the first HB doesn't trigger exponential backoff. 479 * The first unacknowledged HB triggers it. We do this with a flag 480 * that indicates that we have an outstanding HB. 481 */ 482 if (!is_hb || transport->hb_sent) { 483 transport->rto = min((transport->rto * 2), transport->asoc->rto_max); 484 } 485 } 486 487 /* Worker routine to handle INIT command failure. */ 488 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands, 489 struct sctp_association *asoc, 490 unsigned error) 491 { 492 struct sctp_ulpevent *event; 493 494 event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC, 495 (__u16)error, 0, 0, NULL, 496 GFP_ATOMIC); 497 498 if (event) 499 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, 500 SCTP_ULPEVENT(event)); 501 502 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, 503 SCTP_STATE(SCTP_STATE_CLOSED)); 504 505 /* SEND_FAILED sent later when cleaning up the association. */ 506 asoc->outqueue.error = error; 507 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); 508 } 509 510 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED. */ 511 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands, 512 struct sctp_association *asoc, 513 sctp_event_t event_type, 514 sctp_subtype_t subtype, 515 struct sctp_chunk *chunk, 516 unsigned error) 517 { 518 struct sctp_ulpevent *event; 519 520 /* Cancel any partial delivery in progress. */ 521 sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC); 522 523 if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT) 524 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST, 525 (__u16)error, 0, 0, chunk, 526 GFP_ATOMIC); 527 else 528 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST, 529 (__u16)error, 0, 0, NULL, 530 GFP_ATOMIC); 531 if (event) 532 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, 533 SCTP_ULPEVENT(event)); 534 535 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, 536 SCTP_STATE(SCTP_STATE_CLOSED)); 537 538 /* SEND_FAILED sent later when cleaning up the association. */ 539 asoc->outqueue.error = error; 540 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); 541 } 542 543 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT 544 * inside the cookie. In reality, this is only used for INIT-ACK processing 545 * since all other cases use "temporary" associations and can do all 546 * their work in statefuns directly. 547 */ 548 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands, 549 struct sctp_association *asoc, 550 struct sctp_chunk *chunk, 551 sctp_init_chunk_t *peer_init, 552 gfp_t gfp) 553 { 554 int error; 555 556 /* We only process the init as a sideeffect in a single 557 * case. This is when we process the INIT-ACK. If we 558 * fail during INIT processing (due to malloc problems), 559 * just return the error and stop processing the stack. 560 */ 561 if (!sctp_process_init(asoc, chunk->chunk_hdr->type, 562 sctp_source(chunk), peer_init, gfp)) 563 error = -ENOMEM; 564 else 565 error = 0; 566 567 return error; 568 } 569 570 /* Helper function to break out starting up of heartbeat timers. */ 571 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds, 572 struct sctp_association *asoc) 573 { 574 struct sctp_transport *t; 575 576 /* Start a heartbeat timer for each transport on the association. 577 * hold a reference on the transport to make sure none of 578 * the needed data structures go away. 579 */ 580 list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) { 581 582 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t))) 583 sctp_transport_hold(t); 584 } 585 } 586 587 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds, 588 struct sctp_association *asoc) 589 { 590 struct sctp_transport *t; 591 592 /* Stop all heartbeat timers. */ 593 594 list_for_each_entry(t, &asoc->peer.transport_addr_list, 595 transports) { 596 if (del_timer(&t->hb_timer)) 597 sctp_transport_put(t); 598 } 599 } 600 601 /* Helper function to stop any pending T3-RTX timers */ 602 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds, 603 struct sctp_association *asoc) 604 { 605 struct sctp_transport *t; 606 607 list_for_each_entry(t, &asoc->peer.transport_addr_list, 608 transports) { 609 if (timer_pending(&t->T3_rtx_timer) && 610 del_timer(&t->T3_rtx_timer)) { 611 sctp_transport_put(t); 612 } 613 } 614 } 615 616 617 /* Helper function to update the heartbeat timer. */ 618 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds, 619 struct sctp_transport *t) 620 { 621 /* Update the heartbeat timer. */ 622 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t))) 623 sctp_transport_hold(t); 624 } 625 626 /* Helper function to handle the reception of an HEARTBEAT ACK. */ 627 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds, 628 struct sctp_association *asoc, 629 struct sctp_transport *t, 630 struct sctp_chunk *chunk) 631 { 632 sctp_sender_hb_info_t *hbinfo; 633 634 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the 635 * HEARTBEAT should clear the error counter of the destination 636 * transport address to which the HEARTBEAT was sent. 637 * The association's overall error count is also cleared. 638 */ 639 t->error_count = 0; 640 t->asoc->overall_error_count = 0; 641 642 /* Clear the hb_sent flag to signal that we had a good 643 * acknowledgement. 644 */ 645 t->hb_sent = 0; 646 647 /* Mark the destination transport address as active if it is not so 648 * marked. 649 */ 650 if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) 651 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP, 652 SCTP_HEARTBEAT_SUCCESS); 653 654 /* The receiver of the HEARTBEAT ACK should also perform an 655 * RTT measurement for that destination transport address 656 * using the time value carried in the HEARTBEAT ACK chunk. 657 * If the transport's rto_pending variable has been cleared, 658 * it was most likely due to a retransmit. However, we want 659 * to re-enable it to properly update the rto. 660 */ 661 if (t->rto_pending == 0) 662 t->rto_pending = 1; 663 664 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data; 665 sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at)); 666 667 /* Update the heartbeat timer. */ 668 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t))) 669 sctp_transport_hold(t); 670 } 671 672 673 /* Helper function to process the process SACK command. */ 674 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds, 675 struct sctp_association *asoc, 676 struct sctp_sackhdr *sackh) 677 { 678 int err = 0; 679 680 if (sctp_outq_sack(&asoc->outqueue, sackh)) { 681 /* There are no more TSNs awaiting SACK. */ 682 err = sctp_do_sm(SCTP_EVENT_T_OTHER, 683 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN), 684 asoc->state, asoc->ep, asoc, NULL, 685 GFP_ATOMIC); 686 } 687 688 return err; 689 } 690 691 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set 692 * the transport for a shutdown chunk. 693 */ 694 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds, 695 struct sctp_association *asoc, 696 struct sctp_chunk *chunk) 697 { 698 struct sctp_transport *t; 699 700 t = sctp_assoc_choose_alter_transport(asoc, 701 asoc->shutdown_last_sent_to); 702 asoc->shutdown_last_sent_to = t; 703 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto; 704 chunk->transport = t; 705 } 706 707 /* Helper function to change the state of an association. */ 708 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds, 709 struct sctp_association *asoc, 710 sctp_state_t state) 711 { 712 struct sock *sk = asoc->base.sk; 713 714 asoc->state = state; 715 716 SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n", 717 asoc, sctp_state_tbl[state]); 718 719 if (sctp_style(sk, TCP)) { 720 /* Change the sk->sk_state of a TCP-style socket that has 721 * successfully completed a connect() call. 722 */ 723 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED)) 724 sk->sk_state = SCTP_SS_ESTABLISHED; 725 726 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */ 727 if (sctp_state(asoc, SHUTDOWN_RECEIVED) && 728 sctp_sstate(sk, ESTABLISHED)) 729 sk->sk_shutdown |= RCV_SHUTDOWN; 730 } 731 732 if (sctp_state(asoc, COOKIE_WAIT)) { 733 /* Reset init timeouts since they may have been 734 * increased due to timer expirations. 735 */ 736 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = 737 asoc->rto_initial; 738 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = 739 asoc->rto_initial; 740 } 741 742 if (sctp_state(asoc, ESTABLISHED) || 743 sctp_state(asoc, CLOSED) || 744 sctp_state(asoc, SHUTDOWN_RECEIVED)) { 745 /* Wake up any processes waiting in the asoc's wait queue in 746 * sctp_wait_for_connect() or sctp_wait_for_sndbuf(). 747 */ 748 if (waitqueue_active(&asoc->wait)) 749 wake_up_interruptible(&asoc->wait); 750 751 /* Wake up any processes waiting in the sk's sleep queue of 752 * a TCP-style or UDP-style peeled-off socket in 753 * sctp_wait_for_accept() or sctp_wait_for_packet(). 754 * For a UDP-style socket, the waiters are woken up by the 755 * notifications. 756 */ 757 if (!sctp_style(sk, UDP)) 758 sk->sk_state_change(sk); 759 } 760 } 761 762 /* Helper function to delete an association. */ 763 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds, 764 struct sctp_association *asoc) 765 { 766 struct sock *sk = asoc->base.sk; 767 768 /* If it is a non-temporary association belonging to a TCP-style 769 * listening socket that is not closed, do not free it so that accept() 770 * can pick it up later. 771 */ 772 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) && 773 (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK)) 774 return; 775 776 sctp_unhash_established(asoc); 777 sctp_association_free(asoc); 778 } 779 780 /* 781 * ADDIP Section 4.1 ASCONF Chunk Procedures 782 * A4) Start a T-4 RTO timer, using the RTO value of the selected 783 * destination address (we use active path instead of primary path just 784 * because primary path may be inactive. 785 */ 786 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds, 787 struct sctp_association *asoc, 788 struct sctp_chunk *chunk) 789 { 790 struct sctp_transport *t; 791 792 t = sctp_assoc_choose_alter_transport(asoc, chunk->transport); 793 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto; 794 chunk->transport = t; 795 } 796 797 /* Process an incoming Operation Error Chunk. */ 798 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds, 799 struct sctp_association *asoc, 800 struct sctp_chunk *chunk) 801 { 802 struct sctp_errhdr *err_hdr; 803 struct sctp_ulpevent *ev; 804 805 while (chunk->chunk_end > chunk->skb->data) { 806 err_hdr = (struct sctp_errhdr *)(chunk->skb->data); 807 808 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0, 809 GFP_ATOMIC); 810 if (!ev) 811 return; 812 813 sctp_ulpq_tail_event(&asoc->ulpq, ev); 814 815 switch (err_hdr->cause) { 816 case SCTP_ERROR_UNKNOWN_CHUNK: 817 { 818 sctp_chunkhdr_t *unk_chunk_hdr; 819 820 unk_chunk_hdr = (sctp_chunkhdr_t *)err_hdr->variable; 821 switch (unk_chunk_hdr->type) { 822 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with 823 * an ERROR chunk reporting that it did not recognized 824 * the ASCONF chunk type, the sender of the ASCONF MUST 825 * NOT send any further ASCONF chunks and MUST stop its 826 * T-4 timer. 827 */ 828 case SCTP_CID_ASCONF: 829 if (asoc->peer.asconf_capable == 0) 830 break; 831 832 asoc->peer.asconf_capable = 0; 833 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP, 834 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); 835 break; 836 default: 837 break; 838 } 839 break; 840 } 841 default: 842 break; 843 } 844 } 845 } 846 847 /* Process variable FWDTSN chunk information. */ 848 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq, 849 struct sctp_chunk *chunk) 850 { 851 struct sctp_fwdtsn_skip *skip; 852 /* Walk through all the skipped SSNs */ 853 sctp_walk_fwdtsn(skip, chunk) { 854 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn)); 855 } 856 857 return; 858 } 859 860 /* Helper function to remove the association non-primary peer 861 * transports. 862 */ 863 static void sctp_cmd_del_non_primary(struct sctp_association *asoc) 864 { 865 struct sctp_transport *t; 866 struct list_head *pos; 867 struct list_head *temp; 868 869 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 870 t = list_entry(pos, struct sctp_transport, transports); 871 if (!sctp_cmp_addr_exact(&t->ipaddr, 872 &asoc->peer.primary_addr)) { 873 sctp_assoc_del_peer(asoc, &t->ipaddr); 874 } 875 } 876 877 return; 878 } 879 880 /* Helper function to set sk_err on a 1-1 style socket. */ 881 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error) 882 { 883 struct sock *sk = asoc->base.sk; 884 885 if (!sctp_style(sk, UDP)) 886 sk->sk_err = error; 887 } 888 889 /* Helper function to generate an association change event */ 890 static void sctp_cmd_assoc_change(sctp_cmd_seq_t *commands, 891 struct sctp_association *asoc, 892 u8 state) 893 { 894 struct sctp_ulpevent *ev; 895 896 ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0, 897 asoc->c.sinit_num_ostreams, 898 asoc->c.sinit_max_instreams, 899 NULL, GFP_ATOMIC); 900 if (ev) 901 sctp_ulpq_tail_event(&asoc->ulpq, ev); 902 } 903 904 /* Helper function to generate an adaptation indication event */ 905 static void sctp_cmd_adaptation_ind(sctp_cmd_seq_t *commands, 906 struct sctp_association *asoc) 907 { 908 struct sctp_ulpevent *ev; 909 910 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC); 911 912 if (ev) 913 sctp_ulpq_tail_event(&asoc->ulpq, ev); 914 } 915 916 917 static void sctp_cmd_t1_timer_update(struct sctp_association *asoc, 918 sctp_event_timeout_t timer, 919 char *name) 920 { 921 struct sctp_transport *t; 922 923 t = asoc->init_last_sent_to; 924 asoc->init_err_counter++; 925 926 if (t->init_sent_count > (asoc->init_cycle + 1)) { 927 asoc->timeouts[timer] *= 2; 928 if (asoc->timeouts[timer] > asoc->max_init_timeo) { 929 asoc->timeouts[timer] = asoc->max_init_timeo; 930 } 931 asoc->init_cycle++; 932 SCTP_DEBUG_PRINTK( 933 "T1 %s Timeout adjustment" 934 " init_err_counter: %d" 935 " cycle: %d" 936 " timeout: %ld\n", 937 name, 938 asoc->init_err_counter, 939 asoc->init_cycle, 940 asoc->timeouts[timer]); 941 } 942 943 } 944 945 /* Send the whole message, chunk by chunk, to the outqueue. 946 * This way the whole message is queued up and bundling if 947 * encouraged for small fragments. 948 */ 949 static int sctp_cmd_send_msg(struct sctp_association *asoc, 950 struct sctp_datamsg *msg) 951 { 952 struct sctp_chunk *chunk; 953 int error = 0; 954 955 list_for_each_entry(chunk, &msg->chunks, frag_list) { 956 error = sctp_outq_tail(&asoc->outqueue, chunk); 957 if (error) 958 break; 959 } 960 961 return error; 962 } 963 964 965 966 /* These three macros allow us to pull the debugging code out of the 967 * main flow of sctp_do_sm() to keep attention focused on the real 968 * functionality there. 969 */ 970 #define DEBUG_PRE \ 971 SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \ 972 "ep %p, %s, %s, asoc %p[%s], %s\n", \ 973 ep, sctp_evttype_tbl[event_type], \ 974 (*debug_fn)(subtype), asoc, \ 975 sctp_state_tbl[state], state_fn->name) 976 977 #define DEBUG_POST \ 978 SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \ 979 "asoc %p, status: %s\n", \ 980 asoc, sctp_status_tbl[status]) 981 982 #define DEBUG_POST_SFX \ 983 SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \ 984 error, asoc, \ 985 sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \ 986 sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED]) 987 988 /* 989 * This is the master state machine processing function. 990 * 991 * If you want to understand all of lksctp, this is a 992 * good place to start. 993 */ 994 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype, 995 sctp_state_t state, 996 struct sctp_endpoint *ep, 997 struct sctp_association *asoc, 998 void *event_arg, 999 gfp_t gfp) 1000 { 1001 sctp_cmd_seq_t commands; 1002 const sctp_sm_table_entry_t *state_fn; 1003 sctp_disposition_t status; 1004 int error = 0; 1005 typedef const char *(printfn_t)(sctp_subtype_t); 1006 1007 static printfn_t *table[] = { 1008 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname, 1009 }; 1010 printfn_t *debug_fn __attribute__ ((unused)) = table[event_type]; 1011 1012 /* Look up the state function, run it, and then process the 1013 * side effects. These three steps are the heart of lksctp. 1014 */ 1015 state_fn = sctp_sm_lookup_event(event_type, state, subtype); 1016 1017 sctp_init_cmd_seq(&commands); 1018 1019 DEBUG_PRE; 1020 status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands); 1021 DEBUG_POST; 1022 1023 error = sctp_side_effects(event_type, subtype, state, 1024 ep, asoc, event_arg, status, 1025 &commands, gfp); 1026 DEBUG_POST_SFX; 1027 1028 return error; 1029 } 1030 1031 #undef DEBUG_PRE 1032 #undef DEBUG_POST 1033 1034 /***************************************************************** 1035 * This the master state function side effect processing function. 1036 *****************************************************************/ 1037 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype, 1038 sctp_state_t state, 1039 struct sctp_endpoint *ep, 1040 struct sctp_association *asoc, 1041 void *event_arg, 1042 sctp_disposition_t status, 1043 sctp_cmd_seq_t *commands, 1044 gfp_t gfp) 1045 { 1046 int error; 1047 1048 /* FIXME - Most of the dispositions left today would be categorized 1049 * as "exceptional" dispositions. For those dispositions, it 1050 * may not be proper to run through any of the commands at all. 1051 * For example, the command interpreter might be run only with 1052 * disposition SCTP_DISPOSITION_CONSUME. 1053 */ 1054 if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state, 1055 ep, asoc, 1056 event_arg, status, 1057 commands, gfp))) 1058 goto bail; 1059 1060 switch (status) { 1061 case SCTP_DISPOSITION_DISCARD: 1062 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, " 1063 "event_type %d, event_id %d\n", 1064 state, event_type, subtype.chunk); 1065 break; 1066 1067 case SCTP_DISPOSITION_NOMEM: 1068 /* We ran out of memory, so we need to discard this 1069 * packet. 1070 */ 1071 /* BUG--we should now recover some memory, probably by 1072 * reneging... 1073 */ 1074 error = -ENOMEM; 1075 break; 1076 1077 case SCTP_DISPOSITION_DELETE_TCB: 1078 /* This should now be a command. */ 1079 break; 1080 1081 case SCTP_DISPOSITION_CONSUME: 1082 case SCTP_DISPOSITION_ABORT: 1083 /* 1084 * We should no longer have much work to do here as the 1085 * real work has been done as explicit commands above. 1086 */ 1087 break; 1088 1089 case SCTP_DISPOSITION_VIOLATION: 1090 if (net_ratelimit()) 1091 printk(KERN_ERR "sctp protocol violation state %d " 1092 "chunkid %d\n", state, subtype.chunk); 1093 break; 1094 1095 case SCTP_DISPOSITION_NOT_IMPL: 1096 printk(KERN_WARNING "sctp unimplemented feature in state %d, " 1097 "event_type %d, event_id %d\n", 1098 state, event_type, subtype.chunk); 1099 break; 1100 1101 case SCTP_DISPOSITION_BUG: 1102 printk(KERN_ERR "sctp bug in state %d, " 1103 "event_type %d, event_id %d\n", 1104 state, event_type, subtype.chunk); 1105 BUG(); 1106 break; 1107 1108 default: 1109 printk(KERN_ERR "sctp impossible disposition %d " 1110 "in state %d, event_type %d, event_id %d\n", 1111 status, state, event_type, subtype.chunk); 1112 BUG(); 1113 break; 1114 } 1115 1116 bail: 1117 return error; 1118 } 1119 1120 /******************************************************************** 1121 * 2nd Level Abstractions 1122 ********************************************************************/ 1123 1124 /* This is the side-effect interpreter. */ 1125 static int sctp_cmd_interpreter(sctp_event_t event_type, 1126 sctp_subtype_t subtype, 1127 sctp_state_t state, 1128 struct sctp_endpoint *ep, 1129 struct sctp_association *asoc, 1130 void *event_arg, 1131 sctp_disposition_t status, 1132 sctp_cmd_seq_t *commands, 1133 gfp_t gfp) 1134 { 1135 int error = 0; 1136 int force; 1137 sctp_cmd_t *cmd; 1138 struct sctp_chunk *new_obj; 1139 struct sctp_chunk *chunk = NULL; 1140 struct sctp_packet *packet; 1141 struct timer_list *timer; 1142 unsigned long timeout; 1143 struct sctp_transport *t; 1144 struct sctp_sackhdr sackh; 1145 int local_cork = 0; 1146 1147 if (SCTP_EVENT_T_TIMEOUT != event_type) 1148 chunk = (struct sctp_chunk *) event_arg; 1149 1150 /* Note: This whole file is a huge candidate for rework. 1151 * For example, each command could either have its own handler, so 1152 * the loop would look like: 1153 * while (cmds) 1154 * cmd->handle(x, y, z) 1155 * --jgrimm 1156 */ 1157 while (NULL != (cmd = sctp_next_cmd(commands))) { 1158 switch (cmd->verb) { 1159 case SCTP_CMD_NOP: 1160 /* Do nothing. */ 1161 break; 1162 1163 case SCTP_CMD_NEW_ASOC: 1164 /* Register a new association. */ 1165 if (local_cork) { 1166 sctp_outq_uncork(&asoc->outqueue); 1167 local_cork = 0; 1168 } 1169 asoc = cmd->obj.ptr; 1170 /* Register with the endpoint. */ 1171 sctp_endpoint_add_asoc(ep, asoc); 1172 sctp_hash_established(asoc); 1173 break; 1174 1175 case SCTP_CMD_UPDATE_ASSOC: 1176 sctp_assoc_update(asoc, cmd->obj.ptr); 1177 break; 1178 1179 case SCTP_CMD_PURGE_OUTQUEUE: 1180 sctp_outq_teardown(&asoc->outqueue); 1181 break; 1182 1183 case SCTP_CMD_DELETE_TCB: 1184 if (local_cork) { 1185 sctp_outq_uncork(&asoc->outqueue); 1186 local_cork = 0; 1187 } 1188 /* Delete the current association. */ 1189 sctp_cmd_delete_tcb(commands, asoc); 1190 asoc = NULL; 1191 break; 1192 1193 case SCTP_CMD_NEW_STATE: 1194 /* Enter a new state. */ 1195 sctp_cmd_new_state(commands, asoc, cmd->obj.state); 1196 break; 1197 1198 case SCTP_CMD_REPORT_TSN: 1199 /* Record the arrival of a TSN. */ 1200 error = sctp_tsnmap_mark(&asoc->peer.tsn_map, 1201 cmd->obj.u32); 1202 break; 1203 1204 case SCTP_CMD_REPORT_FWDTSN: 1205 /* Move the Cumulattive TSN Ack ahead. */ 1206 sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32); 1207 1208 /* purge the fragmentation queue */ 1209 sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32); 1210 1211 /* Abort any in progress partial delivery. */ 1212 sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC); 1213 break; 1214 1215 case SCTP_CMD_PROCESS_FWDTSN: 1216 sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr); 1217 break; 1218 1219 case SCTP_CMD_GEN_SACK: 1220 /* Generate a Selective ACK. 1221 * The argument tells us whether to just count 1222 * the packet and MAYBE generate a SACK, or 1223 * force a SACK out. 1224 */ 1225 force = cmd->obj.i32; 1226 error = sctp_gen_sack(asoc, force, commands); 1227 break; 1228 1229 case SCTP_CMD_PROCESS_SACK: 1230 /* Process an inbound SACK. */ 1231 error = sctp_cmd_process_sack(commands, asoc, 1232 cmd->obj.ptr); 1233 break; 1234 1235 case SCTP_CMD_GEN_INIT_ACK: 1236 /* Generate an INIT ACK chunk. */ 1237 new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC, 1238 0); 1239 if (!new_obj) 1240 goto nomem; 1241 1242 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, 1243 SCTP_CHUNK(new_obj)); 1244 break; 1245 1246 case SCTP_CMD_PEER_INIT: 1247 /* Process a unified INIT from the peer. 1248 * Note: Only used during INIT-ACK processing. If 1249 * there is an error just return to the outter 1250 * layer which will bail. 1251 */ 1252 error = sctp_cmd_process_init(commands, asoc, chunk, 1253 cmd->obj.ptr, gfp); 1254 break; 1255 1256 case SCTP_CMD_GEN_COOKIE_ECHO: 1257 /* Generate a COOKIE ECHO chunk. */ 1258 new_obj = sctp_make_cookie_echo(asoc, chunk); 1259 if (!new_obj) { 1260 if (cmd->obj.ptr) 1261 sctp_chunk_free(cmd->obj.ptr); 1262 goto nomem; 1263 } 1264 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, 1265 SCTP_CHUNK(new_obj)); 1266 1267 /* If there is an ERROR chunk to be sent along with 1268 * the COOKIE_ECHO, send it, too. 1269 */ 1270 if (cmd->obj.ptr) 1271 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, 1272 SCTP_CHUNK(cmd->obj.ptr)); 1273 1274 if (new_obj->transport) { 1275 new_obj->transport->init_sent_count++; 1276 asoc->init_last_sent_to = new_obj->transport; 1277 } 1278 1279 /* FIXME - Eventually come up with a cleaner way to 1280 * enabling COOKIE-ECHO + DATA bundling during 1281 * multihoming stale cookie scenarios, the following 1282 * command plays with asoc->peer.retran_path to 1283 * avoid the problem of sending the COOKIE-ECHO and 1284 * DATA in different paths, which could result 1285 * in the association being ABORTed if the DATA chunk 1286 * is processed first by the server. Checking the 1287 * init error counter simply causes this command 1288 * to be executed only during failed attempts of 1289 * association establishment. 1290 */ 1291 if ((asoc->peer.retran_path != 1292 asoc->peer.primary_path) && 1293 (asoc->init_err_counter > 0)) { 1294 sctp_add_cmd_sf(commands, 1295 SCTP_CMD_FORCE_PRIM_RETRAN, 1296 SCTP_NULL()); 1297 } 1298 1299 break; 1300 1301 case SCTP_CMD_GEN_SHUTDOWN: 1302 /* Generate SHUTDOWN when in SHUTDOWN_SENT state. 1303 * Reset error counts. 1304 */ 1305 asoc->overall_error_count = 0; 1306 1307 /* Generate a SHUTDOWN chunk. */ 1308 new_obj = sctp_make_shutdown(asoc, chunk); 1309 if (!new_obj) 1310 goto nomem; 1311 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, 1312 SCTP_CHUNK(new_obj)); 1313 break; 1314 1315 case SCTP_CMD_CHUNK_ULP: 1316 /* Send a chunk to the sockets layer. */ 1317 SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n", 1318 "chunk_up:", cmd->obj.ptr, 1319 "ulpq:", &asoc->ulpq); 1320 sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr, 1321 GFP_ATOMIC); 1322 break; 1323 1324 case SCTP_CMD_EVENT_ULP: 1325 /* Send a notification to the sockets layer. */ 1326 SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n", 1327 "event_up:",cmd->obj.ptr, 1328 "ulpq:",&asoc->ulpq); 1329 sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr); 1330 break; 1331 1332 case SCTP_CMD_REPLY: 1333 /* If an caller has not already corked, do cork. */ 1334 if (!asoc->outqueue.cork) { 1335 sctp_outq_cork(&asoc->outqueue); 1336 local_cork = 1; 1337 } 1338 /* Send a chunk to our peer. */ 1339 error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr); 1340 break; 1341 1342 case SCTP_CMD_SEND_PKT: 1343 /* Send a full packet to our peer. */ 1344 packet = cmd->obj.ptr; 1345 sctp_packet_transmit(packet); 1346 sctp_ootb_pkt_free(packet); 1347 break; 1348 1349 case SCTP_CMD_T1_RETRAN: 1350 /* Mark a transport for retransmission. */ 1351 sctp_retransmit(&asoc->outqueue, cmd->obj.transport, 1352 SCTP_RTXR_T1_RTX); 1353 break; 1354 1355 case SCTP_CMD_RETRAN: 1356 /* Mark a transport for retransmission. */ 1357 sctp_retransmit(&asoc->outqueue, cmd->obj.transport, 1358 SCTP_RTXR_T3_RTX); 1359 break; 1360 1361 case SCTP_CMD_TRANSMIT: 1362 /* Kick start transmission. */ 1363 error = sctp_outq_uncork(&asoc->outqueue); 1364 local_cork = 0; 1365 break; 1366 1367 case SCTP_CMD_ECN_CE: 1368 /* Do delayed CE processing. */ 1369 sctp_do_ecn_ce_work(asoc, cmd->obj.u32); 1370 break; 1371 1372 case SCTP_CMD_ECN_ECNE: 1373 /* Do delayed ECNE processing. */ 1374 new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32, 1375 chunk); 1376 if (new_obj) 1377 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, 1378 SCTP_CHUNK(new_obj)); 1379 break; 1380 1381 case SCTP_CMD_ECN_CWR: 1382 /* Do delayed CWR processing. */ 1383 sctp_do_ecn_cwr_work(asoc, cmd->obj.u32); 1384 break; 1385 1386 case SCTP_CMD_SETUP_T2: 1387 sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr); 1388 break; 1389 1390 case SCTP_CMD_TIMER_START: 1391 timer = &asoc->timers[cmd->obj.to]; 1392 timeout = asoc->timeouts[cmd->obj.to]; 1393 BUG_ON(!timeout); 1394 1395 timer->expires = jiffies + timeout; 1396 sctp_association_hold(asoc); 1397 add_timer(timer); 1398 break; 1399 1400 case SCTP_CMD_TIMER_RESTART: 1401 timer = &asoc->timers[cmd->obj.to]; 1402 timeout = asoc->timeouts[cmd->obj.to]; 1403 if (!mod_timer(timer, jiffies + timeout)) 1404 sctp_association_hold(asoc); 1405 break; 1406 1407 case SCTP_CMD_TIMER_STOP: 1408 timer = &asoc->timers[cmd->obj.to]; 1409 if (timer_pending(timer) && del_timer(timer)) 1410 sctp_association_put(asoc); 1411 break; 1412 1413 case SCTP_CMD_INIT_CHOOSE_TRANSPORT: 1414 chunk = cmd->obj.ptr; 1415 t = sctp_assoc_choose_alter_transport(asoc, 1416 asoc->init_last_sent_to); 1417 asoc->init_last_sent_to = t; 1418 chunk->transport = t; 1419 t->init_sent_count++; 1420 /* Set the new transport as primary */ 1421 sctp_assoc_set_primary(asoc, t); 1422 break; 1423 1424 case SCTP_CMD_INIT_RESTART: 1425 /* Do the needed accounting and updates 1426 * associated with restarting an initialization 1427 * timer. Only multiply the timeout by two if 1428 * all transports have been tried at the current 1429 * timeout. 1430 */ 1431 sctp_cmd_t1_timer_update(asoc, 1432 SCTP_EVENT_TIMEOUT_T1_INIT, 1433 "INIT"); 1434 1435 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, 1436 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); 1437 break; 1438 1439 case SCTP_CMD_COOKIEECHO_RESTART: 1440 /* Do the needed accounting and updates 1441 * associated with restarting an initialization 1442 * timer. Only multiply the timeout by two if 1443 * all transports have been tried at the current 1444 * timeout. 1445 */ 1446 sctp_cmd_t1_timer_update(asoc, 1447 SCTP_EVENT_TIMEOUT_T1_COOKIE, 1448 "COOKIE"); 1449 1450 /* If we've sent any data bundled with 1451 * COOKIE-ECHO we need to resend. 1452 */ 1453 list_for_each_entry(t, &asoc->peer.transport_addr_list, 1454 transports) { 1455 sctp_retransmit_mark(&asoc->outqueue, t, 1456 SCTP_RTXR_T1_RTX); 1457 } 1458 1459 sctp_add_cmd_sf(commands, 1460 SCTP_CMD_TIMER_RESTART, 1461 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); 1462 break; 1463 1464 case SCTP_CMD_INIT_FAILED: 1465 sctp_cmd_init_failed(commands, asoc, cmd->obj.err); 1466 break; 1467 1468 case SCTP_CMD_ASSOC_FAILED: 1469 sctp_cmd_assoc_failed(commands, asoc, event_type, 1470 subtype, chunk, cmd->obj.err); 1471 break; 1472 1473 case SCTP_CMD_INIT_COUNTER_INC: 1474 asoc->init_err_counter++; 1475 break; 1476 1477 case SCTP_CMD_INIT_COUNTER_RESET: 1478 asoc->init_err_counter = 0; 1479 asoc->init_cycle = 0; 1480 list_for_each_entry(t, &asoc->peer.transport_addr_list, 1481 transports) { 1482 t->init_sent_count = 0; 1483 } 1484 break; 1485 1486 case SCTP_CMD_REPORT_DUP: 1487 sctp_tsnmap_mark_dup(&asoc->peer.tsn_map, 1488 cmd->obj.u32); 1489 break; 1490 1491 case SCTP_CMD_REPORT_BAD_TAG: 1492 SCTP_DEBUG_PRINTK("vtag mismatch!\n"); 1493 break; 1494 1495 case SCTP_CMD_STRIKE: 1496 /* Mark one strike against a transport. */ 1497 sctp_do_8_2_transport_strike(asoc, cmd->obj.transport, 1498 0); 1499 break; 1500 1501 case SCTP_CMD_TRANSPORT_IDLE: 1502 t = cmd->obj.transport; 1503 sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE); 1504 break; 1505 1506 case SCTP_CMD_TRANSPORT_HB_SENT: 1507 t = cmd->obj.transport; 1508 sctp_do_8_2_transport_strike(asoc, t, 1); 1509 t->hb_sent = 1; 1510 break; 1511 1512 case SCTP_CMD_TRANSPORT_ON: 1513 t = cmd->obj.transport; 1514 sctp_cmd_transport_on(commands, asoc, t, chunk); 1515 break; 1516 1517 case SCTP_CMD_HB_TIMERS_START: 1518 sctp_cmd_hb_timers_start(commands, asoc); 1519 break; 1520 1521 case SCTP_CMD_HB_TIMER_UPDATE: 1522 t = cmd->obj.transport; 1523 sctp_cmd_hb_timer_update(commands, t); 1524 break; 1525 1526 case SCTP_CMD_HB_TIMERS_STOP: 1527 sctp_cmd_hb_timers_stop(commands, asoc); 1528 break; 1529 1530 case SCTP_CMD_REPORT_ERROR: 1531 error = cmd->obj.error; 1532 break; 1533 1534 case SCTP_CMD_PROCESS_CTSN: 1535 /* Dummy up a SACK for processing. */ 1536 sackh.cum_tsn_ack = cmd->obj.be32; 1537 sackh.a_rwnd = asoc->peer.rwnd + 1538 asoc->outqueue.outstanding_bytes; 1539 sackh.num_gap_ack_blocks = 0; 1540 sackh.num_dup_tsns = 0; 1541 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, 1542 SCTP_SACKH(&sackh)); 1543 break; 1544 1545 case SCTP_CMD_DISCARD_PACKET: 1546 /* We need to discard the whole packet. 1547 * Uncork the queue since there might be 1548 * responses pending 1549 */ 1550 chunk->pdiscard = 1; 1551 if (asoc) { 1552 sctp_outq_uncork(&asoc->outqueue); 1553 local_cork = 0; 1554 } 1555 break; 1556 1557 case SCTP_CMD_RTO_PENDING: 1558 t = cmd->obj.transport; 1559 t->rto_pending = 1; 1560 break; 1561 1562 case SCTP_CMD_PART_DELIVER: 1563 sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr, 1564 GFP_ATOMIC); 1565 break; 1566 1567 case SCTP_CMD_RENEGE: 1568 sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr, 1569 GFP_ATOMIC); 1570 break; 1571 1572 case SCTP_CMD_SETUP_T4: 1573 sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr); 1574 break; 1575 1576 case SCTP_CMD_PROCESS_OPERR: 1577 sctp_cmd_process_operr(commands, asoc, chunk); 1578 break; 1579 case SCTP_CMD_CLEAR_INIT_TAG: 1580 asoc->peer.i.init_tag = 0; 1581 break; 1582 case SCTP_CMD_DEL_NON_PRIMARY: 1583 sctp_cmd_del_non_primary(asoc); 1584 break; 1585 case SCTP_CMD_T3_RTX_TIMERS_STOP: 1586 sctp_cmd_t3_rtx_timers_stop(commands, asoc); 1587 break; 1588 case SCTP_CMD_FORCE_PRIM_RETRAN: 1589 t = asoc->peer.retran_path; 1590 asoc->peer.retran_path = asoc->peer.primary_path; 1591 error = sctp_outq_uncork(&asoc->outqueue); 1592 local_cork = 0; 1593 asoc->peer.retran_path = t; 1594 break; 1595 case SCTP_CMD_SET_SK_ERR: 1596 sctp_cmd_set_sk_err(asoc, cmd->obj.error); 1597 break; 1598 case SCTP_CMD_ASSOC_CHANGE: 1599 sctp_cmd_assoc_change(commands, asoc, 1600 cmd->obj.u8); 1601 break; 1602 case SCTP_CMD_ADAPTATION_IND: 1603 sctp_cmd_adaptation_ind(commands, asoc); 1604 break; 1605 1606 case SCTP_CMD_ASSOC_SHKEY: 1607 error = sctp_auth_asoc_init_active_key(asoc, 1608 GFP_ATOMIC); 1609 break; 1610 case SCTP_CMD_UPDATE_INITTAG: 1611 asoc->peer.i.init_tag = cmd->obj.u32; 1612 break; 1613 case SCTP_CMD_SEND_MSG: 1614 if (!asoc->outqueue.cork) { 1615 sctp_outq_cork(&asoc->outqueue); 1616 local_cork = 1; 1617 } 1618 error = sctp_cmd_send_msg(asoc, cmd->obj.msg); 1619 break; 1620 default: 1621 printk(KERN_WARNING "Impossible command: %u, %p\n", 1622 cmd->verb, cmd->obj.ptr); 1623 break; 1624 } 1625 1626 if (error) 1627 break; 1628 } 1629 1630 out: 1631 /* If this is in response to a received chunk, wait until 1632 * we are done with the packet to open the queue so that we don't 1633 * send multiple packets in response to a single request. 1634 */ 1635 if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) { 1636 if (chunk->end_of_packet || chunk->singleton) 1637 error = sctp_outq_uncork(&asoc->outqueue); 1638 } else if (local_cork) 1639 error = sctp_outq_uncork(&asoc->outqueue); 1640 return error; 1641 nomem: 1642 error = -ENOMEM; 1643 goto out; 1644 } 1645 1646