1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* SCTP kernel implementation 3 * (C) Copyright IBM Corp. 2001, 2004 4 * Copyright (c) 1999 Cisco, Inc. 5 * Copyright (c) 1999-2001 Motorola, Inc. 6 * 7 * This file is part of the SCTP kernel implementation 8 * 9 * These functions work with the state functions in sctp_sm_statefuns.c 10 * to implement that state operations. These functions implement the 11 * steps which require modifying existing data structures. 12 * 13 * Please send any bug reports or fixes you make to the 14 * email address(es): 15 * lksctp developers <linux-sctp@vger.kernel.org> 16 * 17 * Written or modified by: 18 * La Monte H.P. Yarroll <piggy@acm.org> 19 * Karl Knutson <karl@athena.chicago.il.us> 20 * Jon Grimm <jgrimm@austin.ibm.com> 21 * Hui Huang <hui.huang@nokia.com> 22 * Dajiang Zhang <dajiang.zhang@nokia.com> 23 * Daisy Chang <daisyc@us.ibm.com> 24 * Sridhar Samudrala <sri@us.ibm.com> 25 * Ardelle Fan <ardelle.fan@intel.com> 26 */ 27 28 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 29 30 #include <linux/skbuff.h> 31 #include <linux/types.h> 32 #include <linux/socket.h> 33 #include <linux/ip.h> 34 #include <linux/gfp.h> 35 #include <net/sock.h> 36 #include <net/sctp/sctp.h> 37 #include <net/sctp/sm.h> 38 #include <net/sctp/stream_sched.h> 39 40 static int sctp_cmd_interpreter(enum sctp_event_type event_type, 41 union sctp_subtype subtype, 42 enum sctp_state state, 43 struct sctp_endpoint *ep, 44 struct sctp_association *asoc, 45 void *event_arg, 46 enum sctp_disposition status, 47 struct sctp_cmd_seq *commands, 48 gfp_t gfp); 49 static int sctp_side_effects(enum sctp_event_type event_type, 50 union sctp_subtype subtype, 51 enum sctp_state state, 52 struct sctp_endpoint *ep, 53 struct sctp_association **asoc, 54 void *event_arg, 55 enum sctp_disposition status, 56 struct sctp_cmd_seq *commands, 57 gfp_t gfp); 58 59 /******************************************************************** 60 * Helper functions 61 ********************************************************************/ 62 63 /* A helper function for delayed processing of INET ECN CE bit. */ 64 static void sctp_do_ecn_ce_work(struct sctp_association *asoc, 65 __u32 lowest_tsn) 66 { 67 /* Save the TSN away for comparison when we receive CWR */ 68 69 asoc->last_ecne_tsn = lowest_tsn; 70 asoc->need_ecne = 1; 71 } 72 73 /* Helper function for delayed processing of SCTP ECNE chunk. */ 74 /* RFC 2960 Appendix A 75 * 76 * RFC 2481 details a specific bit for a sender to send in 77 * the header of its next outbound TCP segment to indicate to 78 * its peer that it has reduced its congestion window. This 79 * is termed the CWR bit. For SCTP the same indication is made 80 * by including the CWR chunk. This chunk contains one data 81 * element, i.e. the TSN number that was sent in the ECNE chunk. 82 * This element represents the lowest TSN number in the datagram 83 * that was originally marked with the CE bit. 84 */ 85 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc, 86 __u32 lowest_tsn, 87 struct sctp_chunk *chunk) 88 { 89 struct sctp_chunk *repl; 90 91 /* Our previously transmitted packet ran into some congestion 92 * so we should take action by reducing cwnd and ssthresh 93 * and then ACK our peer that we we've done so by 94 * sending a CWR. 95 */ 96 97 /* First, try to determine if we want to actually lower 98 * our cwnd variables. Only lower them if the ECNE looks more 99 * recent than the last response. 100 */ 101 if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) { 102 struct sctp_transport *transport; 103 104 /* Find which transport's congestion variables 105 * need to be adjusted. 106 */ 107 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn); 108 109 /* Update the congestion variables. */ 110 if (transport) 111 sctp_transport_lower_cwnd(transport, 112 SCTP_LOWER_CWND_ECNE); 113 asoc->last_cwr_tsn = lowest_tsn; 114 } 115 116 /* Always try to quiet the other end. In case of lost CWR, 117 * resend last_cwr_tsn. 118 */ 119 repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk); 120 121 /* If we run out of memory, it will look like a lost CWR. We'll 122 * get back in sync eventually. 123 */ 124 return repl; 125 } 126 127 /* Helper function to do delayed processing of ECN CWR chunk. */ 128 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc, 129 __u32 lowest_tsn) 130 { 131 /* Turn off ECNE getting auto-prepended to every outgoing 132 * packet 133 */ 134 asoc->need_ecne = 0; 135 } 136 137 /* Generate SACK if necessary. We call this at the end of a packet. */ 138 static int sctp_gen_sack(struct sctp_association *asoc, int force, 139 struct sctp_cmd_seq *commands) 140 { 141 struct sctp_transport *trans = asoc->peer.last_data_from; 142 __u32 ctsn, max_tsn_seen; 143 struct sctp_chunk *sack; 144 int error = 0; 145 146 if (force || 147 (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) || 148 (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE))) 149 asoc->peer.sack_needed = 1; 150 151 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map); 152 max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map); 153 154 /* From 12.2 Parameters necessary per association (i.e. the TCB): 155 * 156 * Ack State : This flag indicates if the next received packet 157 * : is to be responded to with a SACK. ... 158 * : When DATA chunks are out of order, SACK's 159 * : are not delayed (see Section 6). 160 * 161 * [This is actually not mentioned in Section 6, but we 162 * implement it here anyway. --piggy] 163 */ 164 if (max_tsn_seen != ctsn) 165 asoc->peer.sack_needed = 1; 166 167 /* From 6.2 Acknowledgement on Reception of DATA Chunks: 168 * 169 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, 170 * an acknowledgement SHOULD be generated for at least every 171 * second packet (not every second DATA chunk) received, and 172 * SHOULD be generated within 200 ms of the arrival of any 173 * unacknowledged DATA chunk. ... 174 */ 175 if (!asoc->peer.sack_needed) { 176 asoc->peer.sack_cnt++; 177 178 /* Set the SACK delay timeout based on the 179 * SACK delay for the last transport 180 * data was received from, or the default 181 * for the association. 182 */ 183 if (trans) { 184 /* We will need a SACK for the next packet. */ 185 if (asoc->peer.sack_cnt >= trans->sackfreq - 1) 186 asoc->peer.sack_needed = 1; 187 188 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = 189 trans->sackdelay; 190 } else { 191 /* We will need a SACK for the next packet. */ 192 if (asoc->peer.sack_cnt >= asoc->sackfreq - 1) 193 asoc->peer.sack_needed = 1; 194 195 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = 196 asoc->sackdelay; 197 } 198 199 /* Restart the SACK timer. */ 200 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, 201 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK)); 202 } else { 203 __u32 old_a_rwnd = asoc->a_rwnd; 204 205 asoc->a_rwnd = asoc->rwnd; 206 sack = sctp_make_sack(asoc); 207 if (!sack) { 208 asoc->a_rwnd = old_a_rwnd; 209 goto nomem; 210 } 211 212 asoc->peer.sack_needed = 0; 213 asoc->peer.sack_cnt = 0; 214 215 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack)); 216 217 /* Stop the SACK timer. */ 218 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP, 219 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK)); 220 } 221 222 return error; 223 nomem: 224 error = -ENOMEM; 225 return error; 226 } 227 228 /* When the T3-RTX timer expires, it calls this function to create the 229 * relevant state machine event. 230 */ 231 void sctp_generate_t3_rtx_event(struct timer_list *t) 232 { 233 struct sctp_transport *transport = 234 from_timer(transport, t, T3_rtx_timer); 235 struct sctp_association *asoc = transport->asoc; 236 struct sock *sk = asoc->base.sk; 237 struct net *net = sock_net(sk); 238 int error; 239 240 /* Check whether a task is in the sock. */ 241 242 bh_lock_sock(sk); 243 if (sock_owned_by_user(sk)) { 244 pr_debug("%s: sock is busy\n", __func__); 245 246 /* Try again later. */ 247 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20))) 248 sctp_transport_hold(transport); 249 goto out_unlock; 250 } 251 252 /* Run through the state machine. */ 253 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT, 254 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX), 255 asoc->state, 256 asoc->ep, asoc, 257 transport, GFP_ATOMIC); 258 259 if (error) 260 sk->sk_err = -error; 261 262 out_unlock: 263 bh_unlock_sock(sk); 264 sctp_transport_put(transport); 265 } 266 267 /* This is a sa interface for producing timeout events. It works 268 * for timeouts which use the association as their parameter. 269 */ 270 static void sctp_generate_timeout_event(struct sctp_association *asoc, 271 enum sctp_event_timeout timeout_type) 272 { 273 struct sock *sk = asoc->base.sk; 274 struct net *net = sock_net(sk); 275 int error = 0; 276 277 bh_lock_sock(sk); 278 if (sock_owned_by_user(sk)) { 279 pr_debug("%s: sock is busy: timer %d\n", __func__, 280 timeout_type); 281 282 /* Try again later. */ 283 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20))) 284 sctp_association_hold(asoc); 285 goto out_unlock; 286 } 287 288 /* Is this association really dead and just waiting around for 289 * the timer to let go of the reference? 290 */ 291 if (asoc->base.dead) 292 goto out_unlock; 293 294 /* Run through the state machine. */ 295 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT, 296 SCTP_ST_TIMEOUT(timeout_type), 297 asoc->state, asoc->ep, asoc, 298 (void *)timeout_type, GFP_ATOMIC); 299 300 if (error) 301 sk->sk_err = -error; 302 303 out_unlock: 304 bh_unlock_sock(sk); 305 sctp_association_put(asoc); 306 } 307 308 static void sctp_generate_t1_cookie_event(struct timer_list *t) 309 { 310 struct sctp_association *asoc = 311 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T1_COOKIE]); 312 313 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE); 314 } 315 316 static void sctp_generate_t1_init_event(struct timer_list *t) 317 { 318 struct sctp_association *asoc = 319 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T1_INIT]); 320 321 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT); 322 } 323 324 static void sctp_generate_t2_shutdown_event(struct timer_list *t) 325 { 326 struct sctp_association *asoc = 327 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN]); 328 329 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN); 330 } 331 332 static void sctp_generate_t4_rto_event(struct timer_list *t) 333 { 334 struct sctp_association *asoc = 335 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T4_RTO]); 336 337 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO); 338 } 339 340 static void sctp_generate_t5_shutdown_guard_event(struct timer_list *t) 341 { 342 struct sctp_association *asoc = 343 from_timer(asoc, t, 344 timers[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]); 345 346 sctp_generate_timeout_event(asoc, 347 SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD); 348 349 } /* sctp_generate_t5_shutdown_guard_event() */ 350 351 static void sctp_generate_autoclose_event(struct timer_list *t) 352 { 353 struct sctp_association *asoc = 354 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_AUTOCLOSE]); 355 356 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE); 357 } 358 359 /* Generate a heart beat event. If the sock is busy, reschedule. Make 360 * sure that the transport is still valid. 361 */ 362 void sctp_generate_heartbeat_event(struct timer_list *t) 363 { 364 struct sctp_transport *transport = from_timer(transport, t, hb_timer); 365 struct sctp_association *asoc = transport->asoc; 366 struct sock *sk = asoc->base.sk; 367 struct net *net = sock_net(sk); 368 u32 elapsed, timeout; 369 int error = 0; 370 371 bh_lock_sock(sk); 372 if (sock_owned_by_user(sk)) { 373 pr_debug("%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 /* Check if we should still send the heartbeat or reschedule */ 382 elapsed = jiffies - transport->last_time_sent; 383 timeout = sctp_transport_timeout(transport); 384 if (elapsed < timeout) { 385 elapsed = timeout - elapsed; 386 if (!mod_timer(&transport->hb_timer, jiffies + elapsed)) 387 sctp_transport_hold(transport); 388 goto out_unlock; 389 } 390 391 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT, 392 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT), 393 asoc->state, asoc->ep, asoc, 394 transport, GFP_ATOMIC); 395 396 if (error) 397 sk->sk_err = -error; 398 399 out_unlock: 400 bh_unlock_sock(sk); 401 sctp_transport_put(transport); 402 } 403 404 /* Handle the timeout of the ICMP protocol unreachable timer. Trigger 405 * the correct state machine transition that will close the association. 406 */ 407 void sctp_generate_proto_unreach_event(struct timer_list *t) 408 { 409 struct sctp_transport *transport = 410 from_timer(transport, t, proto_unreach_timer); 411 struct sctp_association *asoc = transport->asoc; 412 struct sock *sk = asoc->base.sk; 413 struct net *net = sock_net(sk); 414 415 bh_lock_sock(sk); 416 if (sock_owned_by_user(sk)) { 417 pr_debug("%s: sock is busy\n", __func__); 418 419 /* Try again later. */ 420 if (!mod_timer(&transport->proto_unreach_timer, 421 jiffies + (HZ/20))) 422 sctp_association_hold(asoc); 423 goto out_unlock; 424 } 425 426 /* Is this structure just waiting around for us to actually 427 * get destroyed? 428 */ 429 if (asoc->base.dead) 430 goto out_unlock; 431 432 sctp_do_sm(net, SCTP_EVENT_T_OTHER, 433 SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH), 434 asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC); 435 436 out_unlock: 437 bh_unlock_sock(sk); 438 sctp_association_put(asoc); 439 } 440 441 /* Handle the timeout of the RE-CONFIG timer. */ 442 void sctp_generate_reconf_event(struct timer_list *t) 443 { 444 struct sctp_transport *transport = 445 from_timer(transport, t, reconf_timer); 446 struct sctp_association *asoc = transport->asoc; 447 struct sock *sk = asoc->base.sk; 448 struct net *net = sock_net(sk); 449 int error = 0; 450 451 bh_lock_sock(sk); 452 if (sock_owned_by_user(sk)) { 453 pr_debug("%s: sock is busy\n", __func__); 454 455 /* Try again later. */ 456 if (!mod_timer(&transport->reconf_timer, jiffies + (HZ / 20))) 457 sctp_transport_hold(transport); 458 goto out_unlock; 459 } 460 461 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT, 462 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_RECONF), 463 asoc->state, asoc->ep, asoc, 464 transport, GFP_ATOMIC); 465 466 if (error) 467 sk->sk_err = -error; 468 469 out_unlock: 470 bh_unlock_sock(sk); 471 sctp_transport_put(transport); 472 } 473 474 /* Inject a SACK Timeout event into the state machine. */ 475 static void sctp_generate_sack_event(struct timer_list *t) 476 { 477 struct sctp_association *asoc = 478 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_SACK]); 479 480 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK); 481 } 482 483 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = { 484 [SCTP_EVENT_TIMEOUT_NONE] = NULL, 485 [SCTP_EVENT_TIMEOUT_T1_COOKIE] = sctp_generate_t1_cookie_event, 486 [SCTP_EVENT_TIMEOUT_T1_INIT] = sctp_generate_t1_init_event, 487 [SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = sctp_generate_t2_shutdown_event, 488 [SCTP_EVENT_TIMEOUT_T3_RTX] = NULL, 489 [SCTP_EVENT_TIMEOUT_T4_RTO] = sctp_generate_t4_rto_event, 490 [SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD] = 491 sctp_generate_t5_shutdown_guard_event, 492 [SCTP_EVENT_TIMEOUT_HEARTBEAT] = NULL, 493 [SCTP_EVENT_TIMEOUT_RECONF] = NULL, 494 [SCTP_EVENT_TIMEOUT_SACK] = sctp_generate_sack_event, 495 [SCTP_EVENT_TIMEOUT_AUTOCLOSE] = sctp_generate_autoclose_event, 496 }; 497 498 499 /* RFC 2960 8.2 Path Failure Detection 500 * 501 * When its peer endpoint is multi-homed, an endpoint should keep a 502 * error counter for each of the destination transport addresses of the 503 * peer endpoint. 504 * 505 * Each time the T3-rtx timer expires on any address, or when a 506 * HEARTBEAT sent to an idle address is not acknowledged within a RTO, 507 * the error counter of that destination address will be incremented. 508 * When the value in the error counter exceeds the protocol parameter 509 * 'Path.Max.Retrans' of that destination address, the endpoint should 510 * mark the destination transport address as inactive, and a 511 * notification SHOULD be sent to the upper layer. 512 * 513 */ 514 static void sctp_do_8_2_transport_strike(struct sctp_cmd_seq *commands, 515 struct sctp_association *asoc, 516 struct sctp_transport *transport, 517 int is_hb) 518 { 519 struct net *net = sock_net(asoc->base.sk); 520 521 /* The check for association's overall error counter exceeding the 522 * threshold is done in the state function. 523 */ 524 /* We are here due to a timer expiration. If the timer was 525 * not a HEARTBEAT, then normal error tracking is done. 526 * If the timer was a heartbeat, we only increment error counts 527 * when we already have an outstanding HEARTBEAT that has not 528 * been acknowledged. 529 * Additionally, some tranport states inhibit error increments. 530 */ 531 if (!is_hb) { 532 asoc->overall_error_count++; 533 if (transport->state != SCTP_INACTIVE) 534 transport->error_count++; 535 } else if (transport->hb_sent) { 536 if (transport->state != SCTP_UNCONFIRMED) 537 asoc->overall_error_count++; 538 if (transport->state != SCTP_INACTIVE) 539 transport->error_count++; 540 } 541 542 /* If the transport error count is greater than the pf_retrans 543 * threshold, and less than pathmaxrtx, and if the current state 544 * is SCTP_ACTIVE, then mark this transport as Partially Failed, 545 * see SCTP Quick Failover Draft, section 5.1 546 */ 547 if (net->sctp.pf_enable && 548 (transport->state == SCTP_ACTIVE) && 549 (transport->error_count < transport->pathmaxrxt) && 550 (transport->error_count > transport->pf_retrans)) { 551 552 sctp_assoc_control_transport(asoc, transport, 553 SCTP_TRANSPORT_PF, 554 0); 555 556 /* Update the hb timer to resend a heartbeat every rto */ 557 sctp_transport_reset_hb_timer(transport); 558 } 559 560 if (transport->state != SCTP_INACTIVE && 561 (transport->error_count > transport->pathmaxrxt)) { 562 pr_debug("%s: association:%p transport addr:%pISpc failed\n", 563 __func__, asoc, &transport->ipaddr.sa); 564 565 sctp_assoc_control_transport(asoc, transport, 566 SCTP_TRANSPORT_DOWN, 567 SCTP_FAILED_THRESHOLD); 568 } 569 570 /* E2) For the destination address for which the timer 571 * expires, set RTO <- RTO * 2 ("back off the timer"). The 572 * maximum value discussed in rule C7 above (RTO.max) may be 573 * used to provide an upper bound to this doubling operation. 574 * 575 * Special Case: the first HB doesn't trigger exponential backoff. 576 * The first unacknowledged HB triggers it. We do this with a flag 577 * that indicates that we have an outstanding HB. 578 */ 579 if (!is_hb || transport->hb_sent) { 580 transport->rto = min((transport->rto * 2), transport->asoc->rto_max); 581 sctp_max_rto(asoc, transport); 582 } 583 } 584 585 /* Worker routine to handle INIT command failure. */ 586 static void sctp_cmd_init_failed(struct sctp_cmd_seq *commands, 587 struct sctp_association *asoc, 588 unsigned int error) 589 { 590 struct sctp_ulpevent *event; 591 592 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_CANT_STR_ASSOC, 593 (__u16)error, 0, 0, NULL, 594 GFP_ATOMIC); 595 596 if (event) 597 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, 598 SCTP_ULPEVENT(event)); 599 600 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, 601 SCTP_STATE(SCTP_STATE_CLOSED)); 602 603 /* SEND_FAILED sent later when cleaning up the association. */ 604 asoc->outqueue.error = error; 605 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); 606 } 607 608 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED. */ 609 static void sctp_cmd_assoc_failed(struct sctp_cmd_seq *commands, 610 struct sctp_association *asoc, 611 enum sctp_event_type event_type, 612 union sctp_subtype subtype, 613 struct sctp_chunk *chunk, 614 unsigned int error) 615 { 616 struct sctp_ulpevent *event; 617 struct sctp_chunk *abort; 618 619 /* Cancel any partial delivery in progress. */ 620 asoc->stream.si->abort_pd(&asoc->ulpq, GFP_ATOMIC); 621 622 if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT) 623 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST, 624 (__u16)error, 0, 0, chunk, 625 GFP_ATOMIC); 626 else 627 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST, 628 (__u16)error, 0, 0, NULL, 629 GFP_ATOMIC); 630 if (event) 631 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, 632 SCTP_ULPEVENT(event)); 633 634 if (asoc->overall_error_count >= asoc->max_retrans) { 635 abort = sctp_make_violation_max_retrans(asoc, chunk); 636 if (abort) 637 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, 638 SCTP_CHUNK(abort)); 639 } 640 641 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, 642 SCTP_STATE(SCTP_STATE_CLOSED)); 643 644 /* SEND_FAILED sent later when cleaning up the association. */ 645 asoc->outqueue.error = error; 646 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); 647 } 648 649 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT 650 * inside the cookie. In reality, this is only used for INIT-ACK processing 651 * since all other cases use "temporary" associations and can do all 652 * their work in statefuns directly. 653 */ 654 static int sctp_cmd_process_init(struct sctp_cmd_seq *commands, 655 struct sctp_association *asoc, 656 struct sctp_chunk *chunk, 657 struct sctp_init_chunk *peer_init, 658 gfp_t gfp) 659 { 660 int error; 661 662 /* We only process the init as a sideeffect in a single 663 * case. This is when we process the INIT-ACK. If we 664 * fail during INIT processing (due to malloc problems), 665 * just return the error and stop processing the stack. 666 */ 667 if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp)) 668 error = -ENOMEM; 669 else 670 error = 0; 671 672 return error; 673 } 674 675 /* Helper function to break out starting up of heartbeat timers. */ 676 static void sctp_cmd_hb_timers_start(struct sctp_cmd_seq *cmds, 677 struct sctp_association *asoc) 678 { 679 struct sctp_transport *t; 680 681 /* Start a heartbeat timer for each transport on the association. 682 * hold a reference on the transport to make sure none of 683 * the needed data structures go away. 684 */ 685 list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) 686 sctp_transport_reset_hb_timer(t); 687 } 688 689 static void sctp_cmd_hb_timers_stop(struct sctp_cmd_seq *cmds, 690 struct sctp_association *asoc) 691 { 692 struct sctp_transport *t; 693 694 /* Stop all heartbeat timers. */ 695 696 list_for_each_entry(t, &asoc->peer.transport_addr_list, 697 transports) { 698 if (del_timer(&t->hb_timer)) 699 sctp_transport_put(t); 700 } 701 } 702 703 /* Helper function to stop any pending T3-RTX timers */ 704 static void sctp_cmd_t3_rtx_timers_stop(struct sctp_cmd_seq *cmds, 705 struct sctp_association *asoc) 706 { 707 struct sctp_transport *t; 708 709 list_for_each_entry(t, &asoc->peer.transport_addr_list, 710 transports) { 711 if (del_timer(&t->T3_rtx_timer)) 712 sctp_transport_put(t); 713 } 714 } 715 716 717 /* Helper function to handle the reception of an HEARTBEAT ACK. */ 718 static void sctp_cmd_transport_on(struct sctp_cmd_seq *cmds, 719 struct sctp_association *asoc, 720 struct sctp_transport *t, 721 struct sctp_chunk *chunk) 722 { 723 struct sctp_sender_hb_info *hbinfo; 724 int was_unconfirmed = 0; 725 726 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the 727 * HEARTBEAT should clear the error counter of the destination 728 * transport address to which the HEARTBEAT was sent. 729 */ 730 t->error_count = 0; 731 732 /* 733 * Although RFC4960 specifies that the overall error count must 734 * be cleared when a HEARTBEAT ACK is received, we make an 735 * exception while in SHUTDOWN PENDING. If the peer keeps its 736 * window shut forever, we may never be able to transmit our 737 * outstanding data and rely on the retransmission limit be reached 738 * to shutdown the association. 739 */ 740 if (t->asoc->state < SCTP_STATE_SHUTDOWN_PENDING) 741 t->asoc->overall_error_count = 0; 742 743 /* Clear the hb_sent flag to signal that we had a good 744 * acknowledgement. 745 */ 746 t->hb_sent = 0; 747 748 /* Mark the destination transport address as active if it is not so 749 * marked. 750 */ 751 if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) { 752 was_unconfirmed = 1; 753 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP, 754 SCTP_HEARTBEAT_SUCCESS); 755 } 756 757 if (t->state == SCTP_PF) 758 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP, 759 SCTP_HEARTBEAT_SUCCESS); 760 761 /* HB-ACK was received for a the proper HB. Consider this 762 * forward progress. 763 */ 764 if (t->dst) 765 sctp_transport_dst_confirm(t); 766 767 /* The receiver of the HEARTBEAT ACK should also perform an 768 * RTT measurement for that destination transport address 769 * using the time value carried in the HEARTBEAT ACK chunk. 770 * If the transport's rto_pending variable has been cleared, 771 * it was most likely due to a retransmit. However, we want 772 * to re-enable it to properly update the rto. 773 */ 774 if (t->rto_pending == 0) 775 t->rto_pending = 1; 776 777 hbinfo = (struct sctp_sender_hb_info *)chunk->skb->data; 778 sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at)); 779 780 /* Update the heartbeat timer. */ 781 sctp_transport_reset_hb_timer(t); 782 783 if (was_unconfirmed && asoc->peer.transport_count == 1) 784 sctp_transport_immediate_rtx(t); 785 } 786 787 788 /* Helper function to process the process SACK command. */ 789 static int sctp_cmd_process_sack(struct sctp_cmd_seq *cmds, 790 struct sctp_association *asoc, 791 struct sctp_chunk *chunk) 792 { 793 int err = 0; 794 795 if (sctp_outq_sack(&asoc->outqueue, chunk)) { 796 struct net *net = sock_net(asoc->base.sk); 797 798 /* There are no more TSNs awaiting SACK. */ 799 err = sctp_do_sm(net, SCTP_EVENT_T_OTHER, 800 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN), 801 asoc->state, asoc->ep, asoc, NULL, 802 GFP_ATOMIC); 803 } 804 805 return err; 806 } 807 808 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set 809 * the transport for a shutdown chunk. 810 */ 811 static void sctp_cmd_setup_t2(struct sctp_cmd_seq *cmds, 812 struct sctp_association *asoc, 813 struct sctp_chunk *chunk) 814 { 815 struct sctp_transport *t; 816 817 if (chunk->transport) 818 t = chunk->transport; 819 else { 820 t = sctp_assoc_choose_alter_transport(asoc, 821 asoc->shutdown_last_sent_to); 822 chunk->transport = t; 823 } 824 asoc->shutdown_last_sent_to = t; 825 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto; 826 } 827 828 static void sctp_cmd_assoc_update(struct sctp_cmd_seq *cmds, 829 struct sctp_association *asoc, 830 struct sctp_association *new) 831 { 832 struct net *net = sock_net(asoc->base.sk); 833 struct sctp_chunk *abort; 834 835 if (!sctp_assoc_update(asoc, new)) 836 return; 837 838 abort = sctp_make_abort(asoc, NULL, sizeof(struct sctp_errhdr)); 839 if (abort) { 840 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0); 841 sctp_add_cmd_sf(cmds, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); 842 } 843 sctp_add_cmd_sf(cmds, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNABORTED)); 844 sctp_add_cmd_sf(cmds, SCTP_CMD_ASSOC_FAILED, 845 SCTP_PERR(SCTP_ERROR_RSRC_LOW)); 846 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); 847 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); 848 } 849 850 /* Helper function to change the state of an association. */ 851 static void sctp_cmd_new_state(struct sctp_cmd_seq *cmds, 852 struct sctp_association *asoc, 853 enum sctp_state state) 854 { 855 struct sock *sk = asoc->base.sk; 856 857 asoc->state = state; 858 859 pr_debug("%s: asoc:%p[%s]\n", __func__, asoc, sctp_state_tbl[state]); 860 861 if (sctp_style(sk, TCP)) { 862 /* Change the sk->sk_state of a TCP-style socket that has 863 * successfully completed a connect() call. 864 */ 865 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED)) 866 inet_sk_set_state(sk, SCTP_SS_ESTABLISHED); 867 868 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */ 869 if (sctp_state(asoc, SHUTDOWN_RECEIVED) && 870 sctp_sstate(sk, ESTABLISHED)) { 871 inet_sk_set_state(sk, SCTP_SS_CLOSING); 872 sk->sk_shutdown |= RCV_SHUTDOWN; 873 } 874 } 875 876 if (sctp_state(asoc, COOKIE_WAIT)) { 877 /* Reset init timeouts since they may have been 878 * increased due to timer expirations. 879 */ 880 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = 881 asoc->rto_initial; 882 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = 883 asoc->rto_initial; 884 } 885 886 if (sctp_state(asoc, ESTABLISHED)) { 887 kfree(asoc->peer.cookie); 888 asoc->peer.cookie = NULL; 889 } 890 891 if (sctp_state(asoc, ESTABLISHED) || 892 sctp_state(asoc, CLOSED) || 893 sctp_state(asoc, SHUTDOWN_RECEIVED)) { 894 /* Wake up any processes waiting in the asoc's wait queue in 895 * sctp_wait_for_connect() or sctp_wait_for_sndbuf(). 896 */ 897 if (waitqueue_active(&asoc->wait)) 898 wake_up_interruptible(&asoc->wait); 899 900 /* Wake up any processes waiting in the sk's sleep queue of 901 * a TCP-style or UDP-style peeled-off socket in 902 * sctp_wait_for_accept() or sctp_wait_for_packet(). 903 * For a UDP-style socket, the waiters are woken up by the 904 * notifications. 905 */ 906 if (!sctp_style(sk, UDP)) 907 sk->sk_state_change(sk); 908 } 909 910 if (sctp_state(asoc, SHUTDOWN_PENDING) && 911 !sctp_outq_is_empty(&asoc->outqueue)) 912 sctp_outq_uncork(&asoc->outqueue, GFP_ATOMIC); 913 } 914 915 /* Helper function to delete an association. */ 916 static void sctp_cmd_delete_tcb(struct sctp_cmd_seq *cmds, 917 struct sctp_association *asoc) 918 { 919 struct sock *sk = asoc->base.sk; 920 921 /* If it is a non-temporary association belonging to a TCP-style 922 * listening socket that is not closed, do not free it so that accept() 923 * can pick it up later. 924 */ 925 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) && 926 (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK)) 927 return; 928 929 sctp_association_free(asoc); 930 } 931 932 /* 933 * ADDIP Section 4.1 ASCONF Chunk Procedures 934 * A4) Start a T-4 RTO timer, using the RTO value of the selected 935 * destination address (we use active path instead of primary path just 936 * because primary path may be inactive. 937 */ 938 static void sctp_cmd_setup_t4(struct sctp_cmd_seq *cmds, 939 struct sctp_association *asoc, 940 struct sctp_chunk *chunk) 941 { 942 struct sctp_transport *t; 943 944 t = sctp_assoc_choose_alter_transport(asoc, chunk->transport); 945 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto; 946 chunk->transport = t; 947 } 948 949 /* Process an incoming Operation Error Chunk. */ 950 static void sctp_cmd_process_operr(struct sctp_cmd_seq *cmds, 951 struct sctp_association *asoc, 952 struct sctp_chunk *chunk) 953 { 954 struct sctp_errhdr *err_hdr; 955 struct sctp_ulpevent *ev; 956 957 while (chunk->chunk_end > chunk->skb->data) { 958 err_hdr = (struct sctp_errhdr *)(chunk->skb->data); 959 960 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0, 961 GFP_ATOMIC); 962 if (!ev) 963 return; 964 965 asoc->stream.si->enqueue_event(&asoc->ulpq, ev); 966 967 switch (err_hdr->cause) { 968 case SCTP_ERROR_UNKNOWN_CHUNK: 969 { 970 struct sctp_chunkhdr *unk_chunk_hdr; 971 972 unk_chunk_hdr = (struct sctp_chunkhdr *) 973 err_hdr->variable; 974 switch (unk_chunk_hdr->type) { 975 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with 976 * an ERROR chunk reporting that it did not recognized 977 * the ASCONF chunk type, the sender of the ASCONF MUST 978 * NOT send any further ASCONF chunks and MUST stop its 979 * T-4 timer. 980 */ 981 case SCTP_CID_ASCONF: 982 if (asoc->peer.asconf_capable == 0) 983 break; 984 985 asoc->peer.asconf_capable = 0; 986 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP, 987 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); 988 break; 989 default: 990 break; 991 } 992 break; 993 } 994 default: 995 break; 996 } 997 } 998 } 999 1000 /* Helper function to remove the association non-primary peer 1001 * transports. 1002 */ 1003 static void sctp_cmd_del_non_primary(struct sctp_association *asoc) 1004 { 1005 struct sctp_transport *t; 1006 struct list_head *temp; 1007 struct list_head *pos; 1008 1009 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 1010 t = list_entry(pos, struct sctp_transport, transports); 1011 if (!sctp_cmp_addr_exact(&t->ipaddr, 1012 &asoc->peer.primary_addr)) { 1013 sctp_assoc_rm_peer(asoc, t); 1014 } 1015 } 1016 } 1017 1018 /* Helper function to set sk_err on a 1-1 style socket. */ 1019 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error) 1020 { 1021 struct sock *sk = asoc->base.sk; 1022 1023 if (!sctp_style(sk, UDP)) 1024 sk->sk_err = error; 1025 } 1026 1027 /* Helper function to generate an association change event */ 1028 static void sctp_cmd_assoc_change(struct sctp_cmd_seq *commands, 1029 struct sctp_association *asoc, 1030 u8 state) 1031 { 1032 struct sctp_ulpevent *ev; 1033 1034 ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0, 1035 asoc->c.sinit_num_ostreams, 1036 asoc->c.sinit_max_instreams, 1037 NULL, GFP_ATOMIC); 1038 if (ev) 1039 asoc->stream.si->enqueue_event(&asoc->ulpq, ev); 1040 } 1041 1042 static void sctp_cmd_peer_no_auth(struct sctp_cmd_seq *commands, 1043 struct sctp_association *asoc) 1044 { 1045 struct sctp_ulpevent *ev; 1046 1047 ev = sctp_ulpevent_make_authkey(asoc, 0, SCTP_AUTH_NO_AUTH, GFP_ATOMIC); 1048 if (ev) 1049 asoc->stream.si->enqueue_event(&asoc->ulpq, ev); 1050 } 1051 1052 /* Helper function to generate an adaptation indication event */ 1053 static void sctp_cmd_adaptation_ind(struct sctp_cmd_seq *commands, 1054 struct sctp_association *asoc) 1055 { 1056 struct sctp_ulpevent *ev; 1057 1058 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC); 1059 1060 if (ev) 1061 asoc->stream.si->enqueue_event(&asoc->ulpq, ev); 1062 } 1063 1064 1065 static void sctp_cmd_t1_timer_update(struct sctp_association *asoc, 1066 enum sctp_event_timeout timer, 1067 char *name) 1068 { 1069 struct sctp_transport *t; 1070 1071 t = asoc->init_last_sent_to; 1072 asoc->init_err_counter++; 1073 1074 if (t->init_sent_count > (asoc->init_cycle + 1)) { 1075 asoc->timeouts[timer] *= 2; 1076 if (asoc->timeouts[timer] > asoc->max_init_timeo) { 1077 asoc->timeouts[timer] = asoc->max_init_timeo; 1078 } 1079 asoc->init_cycle++; 1080 1081 pr_debug("%s: T1[%s] timeout adjustment init_err_counter:%d" 1082 " cycle:%d timeout:%ld\n", __func__, name, 1083 asoc->init_err_counter, asoc->init_cycle, 1084 asoc->timeouts[timer]); 1085 } 1086 1087 } 1088 1089 /* Send the whole message, chunk by chunk, to the outqueue. 1090 * This way the whole message is queued up and bundling if 1091 * encouraged for small fragments. 1092 */ 1093 static void sctp_cmd_send_msg(struct sctp_association *asoc, 1094 struct sctp_datamsg *msg, gfp_t gfp) 1095 { 1096 struct sctp_chunk *chunk; 1097 1098 list_for_each_entry(chunk, &msg->chunks, frag_list) 1099 sctp_outq_tail(&asoc->outqueue, chunk, gfp); 1100 1101 asoc->outqueue.sched->enqueue(&asoc->outqueue, msg); 1102 } 1103 1104 1105 /* These three macros allow us to pull the debugging code out of the 1106 * main flow of sctp_do_sm() to keep attention focused on the real 1107 * functionality there. 1108 */ 1109 #define debug_pre_sfn() \ 1110 pr_debug("%s[pre-fn]: ep:%p, %s, %s, asoc:%p[%s], %s\n", __func__, \ 1111 ep, sctp_evttype_tbl[event_type], (*debug_fn)(subtype), \ 1112 asoc, sctp_state_tbl[state], state_fn->name) 1113 1114 #define debug_post_sfn() \ 1115 pr_debug("%s[post-fn]: asoc:%p, status:%s\n", __func__, asoc, \ 1116 sctp_status_tbl[status]) 1117 1118 #define debug_post_sfx() \ 1119 pr_debug("%s[post-sfx]: error:%d, asoc:%p[%s]\n", __func__, error, \ 1120 asoc, sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \ 1121 sctp_assoc2id(asoc))) ? asoc->state : SCTP_STATE_CLOSED]) 1122 1123 /* 1124 * This is the master state machine processing function. 1125 * 1126 * If you want to understand all of lksctp, this is a 1127 * good place to start. 1128 */ 1129 int sctp_do_sm(struct net *net, enum sctp_event_type event_type, 1130 union sctp_subtype subtype, enum sctp_state state, 1131 struct sctp_endpoint *ep, struct sctp_association *asoc, 1132 void *event_arg, gfp_t gfp) 1133 { 1134 typedef const char *(printfn_t)(union sctp_subtype); 1135 static printfn_t *table[] = { 1136 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname, 1137 }; 1138 printfn_t *debug_fn __attribute__ ((unused)) = table[event_type]; 1139 const struct sctp_sm_table_entry *state_fn; 1140 struct sctp_cmd_seq commands; 1141 enum sctp_disposition status; 1142 int error = 0; 1143 1144 /* Look up the state function, run it, and then process the 1145 * side effects. These three steps are the heart of lksctp. 1146 */ 1147 state_fn = sctp_sm_lookup_event(net, event_type, state, subtype); 1148 1149 sctp_init_cmd_seq(&commands); 1150 1151 debug_pre_sfn(); 1152 status = state_fn->fn(net, ep, asoc, subtype, event_arg, &commands); 1153 debug_post_sfn(); 1154 1155 error = sctp_side_effects(event_type, subtype, state, 1156 ep, &asoc, event_arg, status, 1157 &commands, gfp); 1158 debug_post_sfx(); 1159 1160 return error; 1161 } 1162 1163 /***************************************************************** 1164 * This the master state function side effect processing function. 1165 *****************************************************************/ 1166 static int sctp_side_effects(enum sctp_event_type event_type, 1167 union sctp_subtype subtype, 1168 enum sctp_state state, 1169 struct sctp_endpoint *ep, 1170 struct sctp_association **asoc, 1171 void *event_arg, 1172 enum sctp_disposition status, 1173 struct sctp_cmd_seq *commands, 1174 gfp_t gfp) 1175 { 1176 int error; 1177 1178 /* FIXME - Most of the dispositions left today would be categorized 1179 * as "exceptional" dispositions. For those dispositions, it 1180 * may not be proper to run through any of the commands at all. 1181 * For example, the command interpreter might be run only with 1182 * disposition SCTP_DISPOSITION_CONSUME. 1183 */ 1184 if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state, 1185 ep, *asoc, 1186 event_arg, status, 1187 commands, gfp))) 1188 goto bail; 1189 1190 switch (status) { 1191 case SCTP_DISPOSITION_DISCARD: 1192 pr_debug("%s: ignored sctp protocol event - state:%d, " 1193 "event_type:%d, event_id:%d\n", __func__, state, 1194 event_type, subtype.chunk); 1195 break; 1196 1197 case SCTP_DISPOSITION_NOMEM: 1198 /* We ran out of memory, so we need to discard this 1199 * packet. 1200 */ 1201 /* BUG--we should now recover some memory, probably by 1202 * reneging... 1203 */ 1204 error = -ENOMEM; 1205 break; 1206 1207 case SCTP_DISPOSITION_DELETE_TCB: 1208 case SCTP_DISPOSITION_ABORT: 1209 /* This should now be a command. */ 1210 *asoc = NULL; 1211 break; 1212 1213 case SCTP_DISPOSITION_CONSUME: 1214 /* 1215 * We should no longer have much work to do here as the 1216 * real work has been done as explicit commands above. 1217 */ 1218 break; 1219 1220 case SCTP_DISPOSITION_VIOLATION: 1221 net_err_ratelimited("protocol violation state %d chunkid %d\n", 1222 state, subtype.chunk); 1223 break; 1224 1225 case SCTP_DISPOSITION_NOT_IMPL: 1226 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n", 1227 state, event_type, subtype.chunk); 1228 break; 1229 1230 case SCTP_DISPOSITION_BUG: 1231 pr_err("bug in state %d, event_type %d, event_id %d\n", 1232 state, event_type, subtype.chunk); 1233 BUG(); 1234 break; 1235 1236 default: 1237 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n", 1238 status, state, event_type, subtype.chunk); 1239 BUG(); 1240 break; 1241 } 1242 1243 bail: 1244 return error; 1245 } 1246 1247 /******************************************************************** 1248 * 2nd Level Abstractions 1249 ********************************************************************/ 1250 1251 /* This is the side-effect interpreter. */ 1252 static int sctp_cmd_interpreter(enum sctp_event_type event_type, 1253 union sctp_subtype subtype, 1254 enum sctp_state state, 1255 struct sctp_endpoint *ep, 1256 struct sctp_association *asoc, 1257 void *event_arg, 1258 enum sctp_disposition status, 1259 struct sctp_cmd_seq *commands, 1260 gfp_t gfp) 1261 { 1262 struct sctp_sock *sp = sctp_sk(ep->base.sk); 1263 struct sctp_chunk *chunk = NULL, *new_obj; 1264 struct sctp_packet *packet; 1265 struct sctp_sackhdr sackh; 1266 struct timer_list *timer; 1267 struct sctp_transport *t; 1268 unsigned long timeout; 1269 struct sctp_cmd *cmd; 1270 int local_cork = 0; 1271 int error = 0; 1272 int force; 1273 1274 if (SCTP_EVENT_T_TIMEOUT != event_type) 1275 chunk = event_arg; 1276 1277 /* Note: This whole file is a huge candidate for rework. 1278 * For example, each command could either have its own handler, so 1279 * the loop would look like: 1280 * while (cmds) 1281 * cmd->handle(x, y, z) 1282 * --jgrimm 1283 */ 1284 while (NULL != (cmd = sctp_next_cmd(commands))) { 1285 switch (cmd->verb) { 1286 case SCTP_CMD_NOP: 1287 /* Do nothing. */ 1288 break; 1289 1290 case SCTP_CMD_NEW_ASOC: 1291 /* Register a new association. */ 1292 if (local_cork) { 1293 sctp_outq_uncork(&asoc->outqueue, gfp); 1294 local_cork = 0; 1295 } 1296 1297 /* Register with the endpoint. */ 1298 asoc = cmd->obj.asoc; 1299 BUG_ON(asoc->peer.primary_path == NULL); 1300 sctp_endpoint_add_asoc(ep, asoc); 1301 break; 1302 1303 case SCTP_CMD_UPDATE_ASSOC: 1304 sctp_cmd_assoc_update(commands, asoc, cmd->obj.asoc); 1305 break; 1306 1307 case SCTP_CMD_PURGE_OUTQUEUE: 1308 sctp_outq_teardown(&asoc->outqueue); 1309 break; 1310 1311 case SCTP_CMD_DELETE_TCB: 1312 if (local_cork) { 1313 sctp_outq_uncork(&asoc->outqueue, gfp); 1314 local_cork = 0; 1315 } 1316 /* Delete the current association. */ 1317 sctp_cmd_delete_tcb(commands, asoc); 1318 asoc = NULL; 1319 break; 1320 1321 case SCTP_CMD_NEW_STATE: 1322 /* Enter a new state. */ 1323 sctp_cmd_new_state(commands, asoc, cmd->obj.state); 1324 break; 1325 1326 case SCTP_CMD_REPORT_TSN: 1327 /* Record the arrival of a TSN. */ 1328 error = sctp_tsnmap_mark(&asoc->peer.tsn_map, 1329 cmd->obj.u32, NULL); 1330 break; 1331 1332 case SCTP_CMD_REPORT_FWDTSN: 1333 asoc->stream.si->report_ftsn(&asoc->ulpq, cmd->obj.u32); 1334 break; 1335 1336 case SCTP_CMD_PROCESS_FWDTSN: 1337 asoc->stream.si->handle_ftsn(&asoc->ulpq, 1338 cmd->obj.chunk); 1339 break; 1340 1341 case SCTP_CMD_GEN_SACK: 1342 /* Generate a Selective ACK. 1343 * The argument tells us whether to just count 1344 * the packet and MAYBE generate a SACK, or 1345 * force a SACK out. 1346 */ 1347 force = cmd->obj.i32; 1348 error = sctp_gen_sack(asoc, force, commands); 1349 break; 1350 1351 case SCTP_CMD_PROCESS_SACK: 1352 /* Process an inbound SACK. */ 1353 error = sctp_cmd_process_sack(commands, asoc, 1354 cmd->obj.chunk); 1355 break; 1356 1357 case SCTP_CMD_GEN_INIT_ACK: 1358 /* Generate an INIT ACK chunk. */ 1359 new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC, 1360 0); 1361 if (!new_obj) 1362 goto nomem; 1363 1364 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, 1365 SCTP_CHUNK(new_obj)); 1366 break; 1367 1368 case SCTP_CMD_PEER_INIT: 1369 /* Process a unified INIT from the peer. 1370 * Note: Only used during INIT-ACK processing. If 1371 * there is an error just return to the outter 1372 * layer which will bail. 1373 */ 1374 error = sctp_cmd_process_init(commands, asoc, chunk, 1375 cmd->obj.init, gfp); 1376 break; 1377 1378 case SCTP_CMD_GEN_COOKIE_ECHO: 1379 /* Generate a COOKIE ECHO chunk. */ 1380 new_obj = sctp_make_cookie_echo(asoc, chunk); 1381 if (!new_obj) { 1382 if (cmd->obj.chunk) 1383 sctp_chunk_free(cmd->obj.chunk); 1384 goto nomem; 1385 } 1386 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, 1387 SCTP_CHUNK(new_obj)); 1388 1389 /* If there is an ERROR chunk to be sent along with 1390 * the COOKIE_ECHO, send it, too. 1391 */ 1392 if (cmd->obj.chunk) 1393 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, 1394 SCTP_CHUNK(cmd->obj.chunk)); 1395 1396 if (new_obj->transport) { 1397 new_obj->transport->init_sent_count++; 1398 asoc->init_last_sent_to = new_obj->transport; 1399 } 1400 1401 /* FIXME - Eventually come up with a cleaner way to 1402 * enabling COOKIE-ECHO + DATA bundling during 1403 * multihoming stale cookie scenarios, the following 1404 * command plays with asoc->peer.retran_path to 1405 * avoid the problem of sending the COOKIE-ECHO and 1406 * DATA in different paths, which could result 1407 * in the association being ABORTed if the DATA chunk 1408 * is processed first by the server. Checking the 1409 * init error counter simply causes this command 1410 * to be executed only during failed attempts of 1411 * association establishment. 1412 */ 1413 if ((asoc->peer.retran_path != 1414 asoc->peer.primary_path) && 1415 (asoc->init_err_counter > 0)) { 1416 sctp_add_cmd_sf(commands, 1417 SCTP_CMD_FORCE_PRIM_RETRAN, 1418 SCTP_NULL()); 1419 } 1420 1421 break; 1422 1423 case SCTP_CMD_GEN_SHUTDOWN: 1424 /* Generate SHUTDOWN when in SHUTDOWN_SENT state. 1425 * Reset error counts. 1426 */ 1427 asoc->overall_error_count = 0; 1428 1429 /* Generate a SHUTDOWN chunk. */ 1430 new_obj = sctp_make_shutdown(asoc, chunk); 1431 if (!new_obj) 1432 goto nomem; 1433 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, 1434 SCTP_CHUNK(new_obj)); 1435 break; 1436 1437 case SCTP_CMD_CHUNK_ULP: 1438 /* Send a chunk to the sockets layer. */ 1439 pr_debug("%s: sm_sideff: chunk_up:%p, ulpq:%p\n", 1440 __func__, cmd->obj.chunk, &asoc->ulpq); 1441 1442 asoc->stream.si->ulpevent_data(&asoc->ulpq, 1443 cmd->obj.chunk, 1444 GFP_ATOMIC); 1445 break; 1446 1447 case SCTP_CMD_EVENT_ULP: 1448 /* Send a notification to the sockets layer. */ 1449 pr_debug("%s: sm_sideff: event_up:%p, ulpq:%p\n", 1450 __func__, cmd->obj.ulpevent, &asoc->ulpq); 1451 1452 asoc->stream.si->enqueue_event(&asoc->ulpq, 1453 cmd->obj.ulpevent); 1454 break; 1455 1456 case SCTP_CMD_REPLY: 1457 /* If an caller has not already corked, do cork. */ 1458 if (!asoc->outqueue.cork) { 1459 sctp_outq_cork(&asoc->outqueue); 1460 local_cork = 1; 1461 } 1462 /* Send a chunk to our peer. */ 1463 sctp_outq_tail(&asoc->outqueue, cmd->obj.chunk, gfp); 1464 break; 1465 1466 case SCTP_CMD_SEND_PKT: 1467 /* Send a full packet to our peer. */ 1468 packet = cmd->obj.packet; 1469 sctp_packet_transmit(packet, gfp); 1470 sctp_ootb_pkt_free(packet); 1471 break; 1472 1473 case SCTP_CMD_T1_RETRAN: 1474 /* Mark a transport for retransmission. */ 1475 sctp_retransmit(&asoc->outqueue, cmd->obj.transport, 1476 SCTP_RTXR_T1_RTX); 1477 break; 1478 1479 case SCTP_CMD_RETRAN: 1480 /* Mark a transport for retransmission. */ 1481 sctp_retransmit(&asoc->outqueue, cmd->obj.transport, 1482 SCTP_RTXR_T3_RTX); 1483 break; 1484 1485 case SCTP_CMD_ECN_CE: 1486 /* Do delayed CE processing. */ 1487 sctp_do_ecn_ce_work(asoc, cmd->obj.u32); 1488 break; 1489 1490 case SCTP_CMD_ECN_ECNE: 1491 /* Do delayed ECNE processing. */ 1492 new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32, 1493 chunk); 1494 if (new_obj) 1495 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, 1496 SCTP_CHUNK(new_obj)); 1497 break; 1498 1499 case SCTP_CMD_ECN_CWR: 1500 /* Do delayed CWR processing. */ 1501 sctp_do_ecn_cwr_work(asoc, cmd->obj.u32); 1502 break; 1503 1504 case SCTP_CMD_SETUP_T2: 1505 sctp_cmd_setup_t2(commands, asoc, cmd->obj.chunk); 1506 break; 1507 1508 case SCTP_CMD_TIMER_START_ONCE: 1509 timer = &asoc->timers[cmd->obj.to]; 1510 1511 if (timer_pending(timer)) 1512 break; 1513 /* fall through */ 1514 1515 case SCTP_CMD_TIMER_START: 1516 timer = &asoc->timers[cmd->obj.to]; 1517 timeout = asoc->timeouts[cmd->obj.to]; 1518 BUG_ON(!timeout); 1519 1520 timer->expires = jiffies + timeout; 1521 sctp_association_hold(asoc); 1522 add_timer(timer); 1523 break; 1524 1525 case SCTP_CMD_TIMER_RESTART: 1526 timer = &asoc->timers[cmd->obj.to]; 1527 timeout = asoc->timeouts[cmd->obj.to]; 1528 if (!mod_timer(timer, jiffies + timeout)) 1529 sctp_association_hold(asoc); 1530 break; 1531 1532 case SCTP_CMD_TIMER_STOP: 1533 timer = &asoc->timers[cmd->obj.to]; 1534 if (del_timer(timer)) 1535 sctp_association_put(asoc); 1536 break; 1537 1538 case SCTP_CMD_INIT_CHOOSE_TRANSPORT: 1539 chunk = cmd->obj.chunk; 1540 t = sctp_assoc_choose_alter_transport(asoc, 1541 asoc->init_last_sent_to); 1542 asoc->init_last_sent_to = t; 1543 chunk->transport = t; 1544 t->init_sent_count++; 1545 /* Set the new transport as primary */ 1546 sctp_assoc_set_primary(asoc, t); 1547 break; 1548 1549 case SCTP_CMD_INIT_RESTART: 1550 /* Do the needed accounting and updates 1551 * associated with restarting an initialization 1552 * timer. Only multiply the timeout by two if 1553 * all transports have been tried at the current 1554 * timeout. 1555 */ 1556 sctp_cmd_t1_timer_update(asoc, 1557 SCTP_EVENT_TIMEOUT_T1_INIT, 1558 "INIT"); 1559 1560 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, 1561 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); 1562 break; 1563 1564 case SCTP_CMD_COOKIEECHO_RESTART: 1565 /* Do the needed accounting and updates 1566 * associated with restarting an initialization 1567 * timer. Only multiply the timeout by two if 1568 * all transports have been tried at the current 1569 * timeout. 1570 */ 1571 sctp_cmd_t1_timer_update(asoc, 1572 SCTP_EVENT_TIMEOUT_T1_COOKIE, 1573 "COOKIE"); 1574 1575 /* If we've sent any data bundled with 1576 * COOKIE-ECHO we need to resend. 1577 */ 1578 list_for_each_entry(t, &asoc->peer.transport_addr_list, 1579 transports) { 1580 sctp_retransmit_mark(&asoc->outqueue, t, 1581 SCTP_RTXR_T1_RTX); 1582 } 1583 1584 sctp_add_cmd_sf(commands, 1585 SCTP_CMD_TIMER_RESTART, 1586 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); 1587 break; 1588 1589 case SCTP_CMD_INIT_FAILED: 1590 sctp_cmd_init_failed(commands, asoc, cmd->obj.u32); 1591 break; 1592 1593 case SCTP_CMD_ASSOC_FAILED: 1594 sctp_cmd_assoc_failed(commands, asoc, event_type, 1595 subtype, chunk, cmd->obj.u32); 1596 break; 1597 1598 case SCTP_CMD_INIT_COUNTER_INC: 1599 asoc->init_err_counter++; 1600 break; 1601 1602 case SCTP_CMD_INIT_COUNTER_RESET: 1603 asoc->init_err_counter = 0; 1604 asoc->init_cycle = 0; 1605 list_for_each_entry(t, &asoc->peer.transport_addr_list, 1606 transports) { 1607 t->init_sent_count = 0; 1608 } 1609 break; 1610 1611 case SCTP_CMD_REPORT_DUP: 1612 sctp_tsnmap_mark_dup(&asoc->peer.tsn_map, 1613 cmd->obj.u32); 1614 break; 1615 1616 case SCTP_CMD_REPORT_BAD_TAG: 1617 pr_debug("%s: vtag mismatch!\n", __func__); 1618 break; 1619 1620 case SCTP_CMD_STRIKE: 1621 /* Mark one strike against a transport. */ 1622 sctp_do_8_2_transport_strike(commands, asoc, 1623 cmd->obj.transport, 0); 1624 break; 1625 1626 case SCTP_CMD_TRANSPORT_IDLE: 1627 t = cmd->obj.transport; 1628 sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE); 1629 break; 1630 1631 case SCTP_CMD_TRANSPORT_HB_SENT: 1632 t = cmd->obj.transport; 1633 sctp_do_8_2_transport_strike(commands, asoc, 1634 t, 1); 1635 t->hb_sent = 1; 1636 break; 1637 1638 case SCTP_CMD_TRANSPORT_ON: 1639 t = cmd->obj.transport; 1640 sctp_cmd_transport_on(commands, asoc, t, chunk); 1641 break; 1642 1643 case SCTP_CMD_HB_TIMERS_START: 1644 sctp_cmd_hb_timers_start(commands, asoc); 1645 break; 1646 1647 case SCTP_CMD_HB_TIMER_UPDATE: 1648 t = cmd->obj.transport; 1649 sctp_transport_reset_hb_timer(t); 1650 break; 1651 1652 case SCTP_CMD_HB_TIMERS_STOP: 1653 sctp_cmd_hb_timers_stop(commands, asoc); 1654 break; 1655 1656 case SCTP_CMD_REPORT_ERROR: 1657 error = cmd->obj.error; 1658 break; 1659 1660 case SCTP_CMD_PROCESS_CTSN: 1661 /* Dummy up a SACK for processing. */ 1662 sackh.cum_tsn_ack = cmd->obj.be32; 1663 sackh.a_rwnd = htonl(asoc->peer.rwnd + 1664 asoc->outqueue.outstanding_bytes); 1665 sackh.num_gap_ack_blocks = 0; 1666 sackh.num_dup_tsns = 0; 1667 chunk->subh.sack_hdr = &sackh; 1668 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, 1669 SCTP_CHUNK(chunk)); 1670 break; 1671 1672 case SCTP_CMD_DISCARD_PACKET: 1673 /* We need to discard the whole packet. 1674 * Uncork the queue since there might be 1675 * responses pending 1676 */ 1677 chunk->pdiscard = 1; 1678 if (asoc) { 1679 sctp_outq_uncork(&asoc->outqueue, gfp); 1680 local_cork = 0; 1681 } 1682 break; 1683 1684 case SCTP_CMD_RTO_PENDING: 1685 t = cmd->obj.transport; 1686 t->rto_pending = 1; 1687 break; 1688 1689 case SCTP_CMD_PART_DELIVER: 1690 asoc->stream.si->start_pd(&asoc->ulpq, GFP_ATOMIC); 1691 break; 1692 1693 case SCTP_CMD_RENEGE: 1694 asoc->stream.si->renege_events(&asoc->ulpq, 1695 cmd->obj.chunk, 1696 GFP_ATOMIC); 1697 break; 1698 1699 case SCTP_CMD_SETUP_T4: 1700 sctp_cmd_setup_t4(commands, asoc, cmd->obj.chunk); 1701 break; 1702 1703 case SCTP_CMD_PROCESS_OPERR: 1704 sctp_cmd_process_operr(commands, asoc, chunk); 1705 break; 1706 case SCTP_CMD_CLEAR_INIT_TAG: 1707 asoc->peer.i.init_tag = 0; 1708 break; 1709 case SCTP_CMD_DEL_NON_PRIMARY: 1710 sctp_cmd_del_non_primary(asoc); 1711 break; 1712 case SCTP_CMD_T3_RTX_TIMERS_STOP: 1713 sctp_cmd_t3_rtx_timers_stop(commands, asoc); 1714 break; 1715 case SCTP_CMD_FORCE_PRIM_RETRAN: 1716 t = asoc->peer.retran_path; 1717 asoc->peer.retran_path = asoc->peer.primary_path; 1718 sctp_outq_uncork(&asoc->outqueue, gfp); 1719 local_cork = 0; 1720 asoc->peer.retran_path = t; 1721 break; 1722 case SCTP_CMD_SET_SK_ERR: 1723 sctp_cmd_set_sk_err(asoc, cmd->obj.error); 1724 break; 1725 case SCTP_CMD_ASSOC_CHANGE: 1726 sctp_cmd_assoc_change(commands, asoc, 1727 cmd->obj.u8); 1728 break; 1729 case SCTP_CMD_ADAPTATION_IND: 1730 sctp_cmd_adaptation_ind(commands, asoc); 1731 break; 1732 case SCTP_CMD_PEER_NO_AUTH: 1733 sctp_cmd_peer_no_auth(commands, asoc); 1734 break; 1735 1736 case SCTP_CMD_ASSOC_SHKEY: 1737 error = sctp_auth_asoc_init_active_key(asoc, 1738 GFP_ATOMIC); 1739 break; 1740 case SCTP_CMD_UPDATE_INITTAG: 1741 asoc->peer.i.init_tag = cmd->obj.u32; 1742 break; 1743 case SCTP_CMD_SEND_MSG: 1744 if (!asoc->outqueue.cork) { 1745 sctp_outq_cork(&asoc->outqueue); 1746 local_cork = 1; 1747 } 1748 sctp_cmd_send_msg(asoc, cmd->obj.msg, gfp); 1749 break; 1750 case SCTP_CMD_PURGE_ASCONF_QUEUE: 1751 sctp_asconf_queue_teardown(asoc); 1752 break; 1753 1754 case SCTP_CMD_SET_ASOC: 1755 if (asoc && local_cork) { 1756 sctp_outq_uncork(&asoc->outqueue, gfp); 1757 local_cork = 0; 1758 } 1759 asoc = cmd->obj.asoc; 1760 break; 1761 1762 default: 1763 pr_warn("Impossible command: %u\n", 1764 cmd->verb); 1765 break; 1766 } 1767 1768 if (error) 1769 break; 1770 } 1771 1772 out: 1773 /* If this is in response to a received chunk, wait until 1774 * we are done with the packet to open the queue so that we don't 1775 * send multiple packets in response to a single request. 1776 */ 1777 if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) { 1778 if (chunk->end_of_packet || chunk->singleton) 1779 sctp_outq_uncork(&asoc->outqueue, gfp); 1780 } else if (local_cork) 1781 sctp_outq_uncork(&asoc->outqueue, gfp); 1782 1783 if (sp->data_ready_signalled) 1784 sp->data_ready_signalled = 0; 1785 1786 return error; 1787 nomem: 1788 error = -ENOMEM; 1789 goto out; 1790 } 1791