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 if (transport->error_count > transport->ps_retrans && 571 asoc->peer.primary_path == transport && 572 asoc->peer.active_path != transport) 573 sctp_assoc_set_primary(asoc, asoc->peer.active_path); 574 575 /* E2) For the destination address for which the timer 576 * expires, set RTO <- RTO * 2 ("back off the timer"). The 577 * maximum value discussed in rule C7 above (RTO.max) may be 578 * used to provide an upper bound to this doubling operation. 579 * 580 * Special Case: the first HB doesn't trigger exponential backoff. 581 * The first unacknowledged HB triggers it. We do this with a flag 582 * that indicates that we have an outstanding HB. 583 */ 584 if (!is_hb || transport->hb_sent) { 585 transport->rto = min((transport->rto * 2), transport->asoc->rto_max); 586 sctp_max_rto(asoc, transport); 587 } 588 } 589 590 /* Worker routine to handle INIT command failure. */ 591 static void sctp_cmd_init_failed(struct sctp_cmd_seq *commands, 592 struct sctp_association *asoc, 593 unsigned int error) 594 { 595 struct sctp_ulpevent *event; 596 597 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_CANT_STR_ASSOC, 598 (__u16)error, 0, 0, NULL, 599 GFP_ATOMIC); 600 601 if (event) 602 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, 603 SCTP_ULPEVENT(event)); 604 605 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, 606 SCTP_STATE(SCTP_STATE_CLOSED)); 607 608 /* SEND_FAILED sent later when cleaning up the association. */ 609 asoc->outqueue.error = error; 610 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); 611 } 612 613 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED. */ 614 static void sctp_cmd_assoc_failed(struct sctp_cmd_seq *commands, 615 struct sctp_association *asoc, 616 enum sctp_event_type event_type, 617 union sctp_subtype subtype, 618 struct sctp_chunk *chunk, 619 unsigned int error) 620 { 621 struct sctp_ulpevent *event; 622 struct sctp_chunk *abort; 623 624 /* Cancel any partial delivery in progress. */ 625 asoc->stream.si->abort_pd(&asoc->ulpq, GFP_ATOMIC); 626 627 if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT) 628 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST, 629 (__u16)error, 0, 0, chunk, 630 GFP_ATOMIC); 631 else 632 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST, 633 (__u16)error, 0, 0, NULL, 634 GFP_ATOMIC); 635 if (event) 636 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, 637 SCTP_ULPEVENT(event)); 638 639 if (asoc->overall_error_count >= asoc->max_retrans) { 640 abort = sctp_make_violation_max_retrans(asoc, chunk); 641 if (abort) 642 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, 643 SCTP_CHUNK(abort)); 644 } 645 646 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE, 647 SCTP_STATE(SCTP_STATE_CLOSED)); 648 649 /* SEND_FAILED sent later when cleaning up the association. */ 650 asoc->outqueue.error = error; 651 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL()); 652 } 653 654 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT 655 * inside the cookie. In reality, this is only used for INIT-ACK processing 656 * since all other cases use "temporary" associations and can do all 657 * their work in statefuns directly. 658 */ 659 static int sctp_cmd_process_init(struct sctp_cmd_seq *commands, 660 struct sctp_association *asoc, 661 struct sctp_chunk *chunk, 662 struct sctp_init_chunk *peer_init, 663 gfp_t gfp) 664 { 665 int error; 666 667 /* We only process the init as a sideeffect in a single 668 * case. This is when we process the INIT-ACK. If we 669 * fail during INIT processing (due to malloc problems), 670 * just return the error and stop processing the stack. 671 */ 672 if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp)) 673 error = -ENOMEM; 674 else 675 error = 0; 676 677 return error; 678 } 679 680 /* Helper function to break out starting up of heartbeat timers. */ 681 static void sctp_cmd_hb_timers_start(struct sctp_cmd_seq *cmds, 682 struct sctp_association *asoc) 683 { 684 struct sctp_transport *t; 685 686 /* Start a heartbeat timer for each transport on the association. 687 * hold a reference on the transport to make sure none of 688 * the needed data structures go away. 689 */ 690 list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) 691 sctp_transport_reset_hb_timer(t); 692 } 693 694 static void sctp_cmd_hb_timers_stop(struct sctp_cmd_seq *cmds, 695 struct sctp_association *asoc) 696 { 697 struct sctp_transport *t; 698 699 /* Stop all heartbeat timers. */ 700 701 list_for_each_entry(t, &asoc->peer.transport_addr_list, 702 transports) { 703 if (del_timer(&t->hb_timer)) 704 sctp_transport_put(t); 705 } 706 } 707 708 /* Helper function to stop any pending T3-RTX timers */ 709 static void sctp_cmd_t3_rtx_timers_stop(struct sctp_cmd_seq *cmds, 710 struct sctp_association *asoc) 711 { 712 struct sctp_transport *t; 713 714 list_for_each_entry(t, &asoc->peer.transport_addr_list, 715 transports) { 716 if (del_timer(&t->T3_rtx_timer)) 717 sctp_transport_put(t); 718 } 719 } 720 721 722 /* Helper function to handle the reception of an HEARTBEAT ACK. */ 723 static void sctp_cmd_transport_on(struct sctp_cmd_seq *cmds, 724 struct sctp_association *asoc, 725 struct sctp_transport *t, 726 struct sctp_chunk *chunk) 727 { 728 struct sctp_sender_hb_info *hbinfo; 729 int was_unconfirmed = 0; 730 731 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the 732 * HEARTBEAT should clear the error counter of the destination 733 * transport address to which the HEARTBEAT was sent. 734 */ 735 t->error_count = 0; 736 737 /* 738 * Although RFC4960 specifies that the overall error count must 739 * be cleared when a HEARTBEAT ACK is received, we make an 740 * exception while in SHUTDOWN PENDING. If the peer keeps its 741 * window shut forever, we may never be able to transmit our 742 * outstanding data and rely on the retransmission limit be reached 743 * to shutdown the association. 744 */ 745 if (t->asoc->state < SCTP_STATE_SHUTDOWN_PENDING) 746 t->asoc->overall_error_count = 0; 747 748 /* Clear the hb_sent flag to signal that we had a good 749 * acknowledgement. 750 */ 751 t->hb_sent = 0; 752 753 /* Mark the destination transport address as active if it is not so 754 * marked. 755 */ 756 if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) { 757 was_unconfirmed = 1; 758 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP, 759 SCTP_HEARTBEAT_SUCCESS); 760 } 761 762 if (t->state == SCTP_PF) 763 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP, 764 SCTP_HEARTBEAT_SUCCESS); 765 766 /* HB-ACK was received for a the proper HB. Consider this 767 * forward progress. 768 */ 769 if (t->dst) 770 sctp_transport_dst_confirm(t); 771 772 /* The receiver of the HEARTBEAT ACK should also perform an 773 * RTT measurement for that destination transport address 774 * using the time value carried in the HEARTBEAT ACK chunk. 775 * If the transport's rto_pending variable has been cleared, 776 * it was most likely due to a retransmit. However, we want 777 * to re-enable it to properly update the rto. 778 */ 779 if (t->rto_pending == 0) 780 t->rto_pending = 1; 781 782 hbinfo = (struct sctp_sender_hb_info *)chunk->skb->data; 783 sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at)); 784 785 /* Update the heartbeat timer. */ 786 sctp_transport_reset_hb_timer(t); 787 788 if (was_unconfirmed && asoc->peer.transport_count == 1) 789 sctp_transport_immediate_rtx(t); 790 } 791 792 793 /* Helper function to process the process SACK command. */ 794 static int sctp_cmd_process_sack(struct sctp_cmd_seq *cmds, 795 struct sctp_association *asoc, 796 struct sctp_chunk *chunk) 797 { 798 int err = 0; 799 800 if (sctp_outq_sack(&asoc->outqueue, chunk)) { 801 struct net *net = sock_net(asoc->base.sk); 802 803 /* There are no more TSNs awaiting SACK. */ 804 err = sctp_do_sm(net, SCTP_EVENT_T_OTHER, 805 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN), 806 asoc->state, asoc->ep, asoc, NULL, 807 GFP_ATOMIC); 808 } 809 810 return err; 811 } 812 813 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set 814 * the transport for a shutdown chunk. 815 */ 816 static void sctp_cmd_setup_t2(struct sctp_cmd_seq *cmds, 817 struct sctp_association *asoc, 818 struct sctp_chunk *chunk) 819 { 820 struct sctp_transport *t; 821 822 if (chunk->transport) 823 t = chunk->transport; 824 else { 825 t = sctp_assoc_choose_alter_transport(asoc, 826 asoc->shutdown_last_sent_to); 827 chunk->transport = t; 828 } 829 asoc->shutdown_last_sent_to = t; 830 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto; 831 } 832 833 static void sctp_cmd_assoc_update(struct sctp_cmd_seq *cmds, 834 struct sctp_association *asoc, 835 struct sctp_association *new) 836 { 837 struct net *net = sock_net(asoc->base.sk); 838 struct sctp_chunk *abort; 839 840 if (!sctp_assoc_update(asoc, new)) 841 return; 842 843 abort = sctp_make_abort(asoc, NULL, sizeof(struct sctp_errhdr)); 844 if (abort) { 845 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0); 846 sctp_add_cmd_sf(cmds, SCTP_CMD_REPLY, SCTP_CHUNK(abort)); 847 } 848 sctp_add_cmd_sf(cmds, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNABORTED)); 849 sctp_add_cmd_sf(cmds, SCTP_CMD_ASSOC_FAILED, 850 SCTP_PERR(SCTP_ERROR_RSRC_LOW)); 851 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS); 852 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB); 853 } 854 855 /* Helper function to change the state of an association. */ 856 static void sctp_cmd_new_state(struct sctp_cmd_seq *cmds, 857 struct sctp_association *asoc, 858 enum sctp_state state) 859 { 860 struct sock *sk = asoc->base.sk; 861 862 asoc->state = state; 863 864 pr_debug("%s: asoc:%p[%s]\n", __func__, asoc, sctp_state_tbl[state]); 865 866 if (sctp_style(sk, TCP)) { 867 /* Change the sk->sk_state of a TCP-style socket that has 868 * successfully completed a connect() call. 869 */ 870 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED)) 871 inet_sk_set_state(sk, SCTP_SS_ESTABLISHED); 872 873 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */ 874 if (sctp_state(asoc, SHUTDOWN_RECEIVED) && 875 sctp_sstate(sk, ESTABLISHED)) { 876 inet_sk_set_state(sk, SCTP_SS_CLOSING); 877 sk->sk_shutdown |= RCV_SHUTDOWN; 878 } 879 } 880 881 if (sctp_state(asoc, COOKIE_WAIT)) { 882 /* Reset init timeouts since they may have been 883 * increased due to timer expirations. 884 */ 885 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = 886 asoc->rto_initial; 887 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = 888 asoc->rto_initial; 889 } 890 891 if (sctp_state(asoc, ESTABLISHED)) { 892 kfree(asoc->peer.cookie); 893 asoc->peer.cookie = NULL; 894 } 895 896 if (sctp_state(asoc, ESTABLISHED) || 897 sctp_state(asoc, CLOSED) || 898 sctp_state(asoc, SHUTDOWN_RECEIVED)) { 899 /* Wake up any processes waiting in the asoc's wait queue in 900 * sctp_wait_for_connect() or sctp_wait_for_sndbuf(). 901 */ 902 if (waitqueue_active(&asoc->wait)) 903 wake_up_interruptible(&asoc->wait); 904 905 /* Wake up any processes waiting in the sk's sleep queue of 906 * a TCP-style or UDP-style peeled-off socket in 907 * sctp_wait_for_accept() or sctp_wait_for_packet(). 908 * For a UDP-style socket, the waiters are woken up by the 909 * notifications. 910 */ 911 if (!sctp_style(sk, UDP)) 912 sk->sk_state_change(sk); 913 } 914 915 if (sctp_state(asoc, SHUTDOWN_PENDING) && 916 !sctp_outq_is_empty(&asoc->outqueue)) 917 sctp_outq_uncork(&asoc->outqueue, GFP_ATOMIC); 918 } 919 920 /* Helper function to delete an association. */ 921 static void sctp_cmd_delete_tcb(struct sctp_cmd_seq *cmds, 922 struct sctp_association *asoc) 923 { 924 struct sock *sk = asoc->base.sk; 925 926 /* If it is a non-temporary association belonging to a TCP-style 927 * listening socket that is not closed, do not free it so that accept() 928 * can pick it up later. 929 */ 930 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) && 931 (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK)) 932 return; 933 934 sctp_association_free(asoc); 935 } 936 937 /* 938 * ADDIP Section 4.1 ASCONF Chunk Procedures 939 * A4) Start a T-4 RTO timer, using the RTO value of the selected 940 * destination address (we use active path instead of primary path just 941 * because primary path may be inactive. 942 */ 943 static void sctp_cmd_setup_t4(struct sctp_cmd_seq *cmds, 944 struct sctp_association *asoc, 945 struct sctp_chunk *chunk) 946 { 947 struct sctp_transport *t; 948 949 t = sctp_assoc_choose_alter_transport(asoc, chunk->transport); 950 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto; 951 chunk->transport = t; 952 } 953 954 /* Process an incoming Operation Error Chunk. */ 955 static void sctp_cmd_process_operr(struct sctp_cmd_seq *cmds, 956 struct sctp_association *asoc, 957 struct sctp_chunk *chunk) 958 { 959 struct sctp_errhdr *err_hdr; 960 struct sctp_ulpevent *ev; 961 962 while (chunk->chunk_end > chunk->skb->data) { 963 err_hdr = (struct sctp_errhdr *)(chunk->skb->data); 964 965 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0, 966 GFP_ATOMIC); 967 if (!ev) 968 return; 969 970 asoc->stream.si->enqueue_event(&asoc->ulpq, ev); 971 972 switch (err_hdr->cause) { 973 case SCTP_ERROR_UNKNOWN_CHUNK: 974 { 975 struct sctp_chunkhdr *unk_chunk_hdr; 976 977 unk_chunk_hdr = (struct sctp_chunkhdr *) 978 err_hdr->variable; 979 switch (unk_chunk_hdr->type) { 980 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with 981 * an ERROR chunk reporting that it did not recognized 982 * the ASCONF chunk type, the sender of the ASCONF MUST 983 * NOT send any further ASCONF chunks and MUST stop its 984 * T-4 timer. 985 */ 986 case SCTP_CID_ASCONF: 987 if (asoc->peer.asconf_capable == 0) 988 break; 989 990 asoc->peer.asconf_capable = 0; 991 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP, 992 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO)); 993 break; 994 default: 995 break; 996 } 997 break; 998 } 999 default: 1000 break; 1001 } 1002 } 1003 } 1004 1005 /* Helper function to remove the association non-primary peer 1006 * transports. 1007 */ 1008 static void sctp_cmd_del_non_primary(struct sctp_association *asoc) 1009 { 1010 struct sctp_transport *t; 1011 struct list_head *temp; 1012 struct list_head *pos; 1013 1014 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { 1015 t = list_entry(pos, struct sctp_transport, transports); 1016 if (!sctp_cmp_addr_exact(&t->ipaddr, 1017 &asoc->peer.primary_addr)) { 1018 sctp_assoc_rm_peer(asoc, t); 1019 } 1020 } 1021 } 1022 1023 /* Helper function to set sk_err on a 1-1 style socket. */ 1024 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error) 1025 { 1026 struct sock *sk = asoc->base.sk; 1027 1028 if (!sctp_style(sk, UDP)) 1029 sk->sk_err = error; 1030 } 1031 1032 /* Helper function to generate an association change event */ 1033 static void sctp_cmd_assoc_change(struct sctp_cmd_seq *commands, 1034 struct sctp_association *asoc, 1035 u8 state) 1036 { 1037 struct sctp_ulpevent *ev; 1038 1039 ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0, 1040 asoc->c.sinit_num_ostreams, 1041 asoc->c.sinit_max_instreams, 1042 NULL, GFP_ATOMIC); 1043 if (ev) 1044 asoc->stream.si->enqueue_event(&asoc->ulpq, ev); 1045 } 1046 1047 static void sctp_cmd_peer_no_auth(struct sctp_cmd_seq *commands, 1048 struct sctp_association *asoc) 1049 { 1050 struct sctp_ulpevent *ev; 1051 1052 ev = sctp_ulpevent_make_authkey(asoc, 0, SCTP_AUTH_NO_AUTH, GFP_ATOMIC); 1053 if (ev) 1054 asoc->stream.si->enqueue_event(&asoc->ulpq, ev); 1055 } 1056 1057 /* Helper function to generate an adaptation indication event */ 1058 static void sctp_cmd_adaptation_ind(struct sctp_cmd_seq *commands, 1059 struct sctp_association *asoc) 1060 { 1061 struct sctp_ulpevent *ev; 1062 1063 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC); 1064 1065 if (ev) 1066 asoc->stream.si->enqueue_event(&asoc->ulpq, ev); 1067 } 1068 1069 1070 static void sctp_cmd_t1_timer_update(struct sctp_association *asoc, 1071 enum sctp_event_timeout timer, 1072 char *name) 1073 { 1074 struct sctp_transport *t; 1075 1076 t = asoc->init_last_sent_to; 1077 asoc->init_err_counter++; 1078 1079 if (t->init_sent_count > (asoc->init_cycle + 1)) { 1080 asoc->timeouts[timer] *= 2; 1081 if (asoc->timeouts[timer] > asoc->max_init_timeo) { 1082 asoc->timeouts[timer] = asoc->max_init_timeo; 1083 } 1084 asoc->init_cycle++; 1085 1086 pr_debug("%s: T1[%s] timeout adjustment init_err_counter:%d" 1087 " cycle:%d timeout:%ld\n", __func__, name, 1088 asoc->init_err_counter, asoc->init_cycle, 1089 asoc->timeouts[timer]); 1090 } 1091 1092 } 1093 1094 /* Send the whole message, chunk by chunk, to the outqueue. 1095 * This way the whole message is queued up and bundling if 1096 * encouraged for small fragments. 1097 */ 1098 static void sctp_cmd_send_msg(struct sctp_association *asoc, 1099 struct sctp_datamsg *msg, gfp_t gfp) 1100 { 1101 struct sctp_chunk *chunk; 1102 1103 list_for_each_entry(chunk, &msg->chunks, frag_list) 1104 sctp_outq_tail(&asoc->outqueue, chunk, gfp); 1105 1106 asoc->outqueue.sched->enqueue(&asoc->outqueue, msg); 1107 } 1108 1109 1110 /* These three macros allow us to pull the debugging code out of the 1111 * main flow of sctp_do_sm() to keep attention focused on the real 1112 * functionality there. 1113 */ 1114 #define debug_pre_sfn() \ 1115 pr_debug("%s[pre-fn]: ep:%p, %s, %s, asoc:%p[%s], %s\n", __func__, \ 1116 ep, sctp_evttype_tbl[event_type], (*debug_fn)(subtype), \ 1117 asoc, sctp_state_tbl[state], state_fn->name) 1118 1119 #define debug_post_sfn() \ 1120 pr_debug("%s[post-fn]: asoc:%p, status:%s\n", __func__, asoc, \ 1121 sctp_status_tbl[status]) 1122 1123 #define debug_post_sfx() \ 1124 pr_debug("%s[post-sfx]: error:%d, asoc:%p[%s]\n", __func__, error, \ 1125 asoc, sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \ 1126 sctp_assoc2id(asoc))) ? asoc->state : SCTP_STATE_CLOSED]) 1127 1128 /* 1129 * This is the master state machine processing function. 1130 * 1131 * If you want to understand all of lksctp, this is a 1132 * good place to start. 1133 */ 1134 int sctp_do_sm(struct net *net, enum sctp_event_type event_type, 1135 union sctp_subtype subtype, enum sctp_state state, 1136 struct sctp_endpoint *ep, struct sctp_association *asoc, 1137 void *event_arg, gfp_t gfp) 1138 { 1139 typedef const char *(printfn_t)(union sctp_subtype); 1140 static printfn_t *table[] = { 1141 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname, 1142 }; 1143 printfn_t *debug_fn __attribute__ ((unused)) = table[event_type]; 1144 const struct sctp_sm_table_entry *state_fn; 1145 struct sctp_cmd_seq commands; 1146 enum sctp_disposition status; 1147 int error = 0; 1148 1149 /* Look up the state function, run it, and then process the 1150 * side effects. These three steps are the heart of lksctp. 1151 */ 1152 state_fn = sctp_sm_lookup_event(net, event_type, state, subtype); 1153 1154 sctp_init_cmd_seq(&commands); 1155 1156 debug_pre_sfn(); 1157 status = state_fn->fn(net, ep, asoc, subtype, event_arg, &commands); 1158 debug_post_sfn(); 1159 1160 error = sctp_side_effects(event_type, subtype, state, 1161 ep, &asoc, event_arg, status, 1162 &commands, gfp); 1163 debug_post_sfx(); 1164 1165 return error; 1166 } 1167 1168 /***************************************************************** 1169 * This the master state function side effect processing function. 1170 *****************************************************************/ 1171 static int sctp_side_effects(enum sctp_event_type event_type, 1172 union sctp_subtype subtype, 1173 enum sctp_state state, 1174 struct sctp_endpoint *ep, 1175 struct sctp_association **asoc, 1176 void *event_arg, 1177 enum sctp_disposition status, 1178 struct sctp_cmd_seq *commands, 1179 gfp_t gfp) 1180 { 1181 int error; 1182 1183 /* FIXME - Most of the dispositions left today would be categorized 1184 * as "exceptional" dispositions. For those dispositions, it 1185 * may not be proper to run through any of the commands at all. 1186 * For example, the command interpreter might be run only with 1187 * disposition SCTP_DISPOSITION_CONSUME. 1188 */ 1189 if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state, 1190 ep, *asoc, 1191 event_arg, status, 1192 commands, gfp))) 1193 goto bail; 1194 1195 switch (status) { 1196 case SCTP_DISPOSITION_DISCARD: 1197 pr_debug("%s: ignored sctp protocol event - state:%d, " 1198 "event_type:%d, event_id:%d\n", __func__, state, 1199 event_type, subtype.chunk); 1200 break; 1201 1202 case SCTP_DISPOSITION_NOMEM: 1203 /* We ran out of memory, so we need to discard this 1204 * packet. 1205 */ 1206 /* BUG--we should now recover some memory, probably by 1207 * reneging... 1208 */ 1209 error = -ENOMEM; 1210 break; 1211 1212 case SCTP_DISPOSITION_DELETE_TCB: 1213 case SCTP_DISPOSITION_ABORT: 1214 /* This should now be a command. */ 1215 *asoc = NULL; 1216 break; 1217 1218 case SCTP_DISPOSITION_CONSUME: 1219 /* 1220 * We should no longer have much work to do here as the 1221 * real work has been done as explicit commands above. 1222 */ 1223 break; 1224 1225 case SCTP_DISPOSITION_VIOLATION: 1226 net_err_ratelimited("protocol violation state %d chunkid %d\n", 1227 state, subtype.chunk); 1228 break; 1229 1230 case SCTP_DISPOSITION_NOT_IMPL: 1231 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n", 1232 state, event_type, subtype.chunk); 1233 break; 1234 1235 case SCTP_DISPOSITION_BUG: 1236 pr_err("bug in state %d, event_type %d, event_id %d\n", 1237 state, event_type, subtype.chunk); 1238 BUG(); 1239 break; 1240 1241 default: 1242 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n", 1243 status, state, event_type, subtype.chunk); 1244 BUG(); 1245 break; 1246 } 1247 1248 bail: 1249 return error; 1250 } 1251 1252 /******************************************************************** 1253 * 2nd Level Abstractions 1254 ********************************************************************/ 1255 1256 /* This is the side-effect interpreter. */ 1257 static int sctp_cmd_interpreter(enum sctp_event_type event_type, 1258 union sctp_subtype subtype, 1259 enum sctp_state state, 1260 struct sctp_endpoint *ep, 1261 struct sctp_association *asoc, 1262 void *event_arg, 1263 enum sctp_disposition status, 1264 struct sctp_cmd_seq *commands, 1265 gfp_t gfp) 1266 { 1267 struct sctp_sock *sp = sctp_sk(ep->base.sk); 1268 struct sctp_chunk *chunk = NULL, *new_obj; 1269 struct sctp_packet *packet; 1270 struct sctp_sackhdr sackh; 1271 struct timer_list *timer; 1272 struct sctp_transport *t; 1273 unsigned long timeout; 1274 struct sctp_cmd *cmd; 1275 int local_cork = 0; 1276 int error = 0; 1277 int force; 1278 1279 if (SCTP_EVENT_T_TIMEOUT != event_type) 1280 chunk = event_arg; 1281 1282 /* Note: This whole file is a huge candidate for rework. 1283 * For example, each command could either have its own handler, so 1284 * the loop would look like: 1285 * while (cmds) 1286 * cmd->handle(x, y, z) 1287 * --jgrimm 1288 */ 1289 while (NULL != (cmd = sctp_next_cmd(commands))) { 1290 switch (cmd->verb) { 1291 case SCTP_CMD_NOP: 1292 /* Do nothing. */ 1293 break; 1294 1295 case SCTP_CMD_NEW_ASOC: 1296 /* Register a new association. */ 1297 if (local_cork) { 1298 sctp_outq_uncork(&asoc->outqueue, gfp); 1299 local_cork = 0; 1300 } 1301 1302 /* Register with the endpoint. */ 1303 asoc = cmd->obj.asoc; 1304 BUG_ON(asoc->peer.primary_path == NULL); 1305 sctp_endpoint_add_asoc(ep, asoc); 1306 break; 1307 1308 case SCTP_CMD_UPDATE_ASSOC: 1309 sctp_cmd_assoc_update(commands, asoc, cmd->obj.asoc); 1310 break; 1311 1312 case SCTP_CMD_PURGE_OUTQUEUE: 1313 sctp_outq_teardown(&asoc->outqueue); 1314 break; 1315 1316 case SCTP_CMD_DELETE_TCB: 1317 if (local_cork) { 1318 sctp_outq_uncork(&asoc->outqueue, gfp); 1319 local_cork = 0; 1320 } 1321 /* Delete the current association. */ 1322 sctp_cmd_delete_tcb(commands, asoc); 1323 asoc = NULL; 1324 break; 1325 1326 case SCTP_CMD_NEW_STATE: 1327 /* Enter a new state. */ 1328 sctp_cmd_new_state(commands, asoc, cmd->obj.state); 1329 break; 1330 1331 case SCTP_CMD_REPORT_TSN: 1332 /* Record the arrival of a TSN. */ 1333 error = sctp_tsnmap_mark(&asoc->peer.tsn_map, 1334 cmd->obj.u32, NULL); 1335 break; 1336 1337 case SCTP_CMD_REPORT_FWDTSN: 1338 asoc->stream.si->report_ftsn(&asoc->ulpq, cmd->obj.u32); 1339 break; 1340 1341 case SCTP_CMD_PROCESS_FWDTSN: 1342 asoc->stream.si->handle_ftsn(&asoc->ulpq, 1343 cmd->obj.chunk); 1344 break; 1345 1346 case SCTP_CMD_GEN_SACK: 1347 /* Generate a Selective ACK. 1348 * The argument tells us whether to just count 1349 * the packet and MAYBE generate a SACK, or 1350 * force a SACK out. 1351 */ 1352 force = cmd->obj.i32; 1353 error = sctp_gen_sack(asoc, force, commands); 1354 break; 1355 1356 case SCTP_CMD_PROCESS_SACK: 1357 /* Process an inbound SACK. */ 1358 error = sctp_cmd_process_sack(commands, asoc, 1359 cmd->obj.chunk); 1360 break; 1361 1362 case SCTP_CMD_GEN_INIT_ACK: 1363 /* Generate an INIT ACK chunk. */ 1364 new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC, 1365 0); 1366 if (!new_obj) 1367 goto nomem; 1368 1369 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, 1370 SCTP_CHUNK(new_obj)); 1371 break; 1372 1373 case SCTP_CMD_PEER_INIT: 1374 /* Process a unified INIT from the peer. 1375 * Note: Only used during INIT-ACK processing. If 1376 * there is an error just return to the outter 1377 * layer which will bail. 1378 */ 1379 error = sctp_cmd_process_init(commands, asoc, chunk, 1380 cmd->obj.init, gfp); 1381 break; 1382 1383 case SCTP_CMD_GEN_COOKIE_ECHO: 1384 /* Generate a COOKIE ECHO chunk. */ 1385 new_obj = sctp_make_cookie_echo(asoc, chunk); 1386 if (!new_obj) { 1387 if (cmd->obj.chunk) 1388 sctp_chunk_free(cmd->obj.chunk); 1389 goto nomem; 1390 } 1391 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, 1392 SCTP_CHUNK(new_obj)); 1393 1394 /* If there is an ERROR chunk to be sent along with 1395 * the COOKIE_ECHO, send it, too. 1396 */ 1397 if (cmd->obj.chunk) 1398 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, 1399 SCTP_CHUNK(cmd->obj.chunk)); 1400 1401 if (new_obj->transport) { 1402 new_obj->transport->init_sent_count++; 1403 asoc->init_last_sent_to = new_obj->transport; 1404 } 1405 1406 /* FIXME - Eventually come up with a cleaner way to 1407 * enabling COOKIE-ECHO + DATA bundling during 1408 * multihoming stale cookie scenarios, the following 1409 * command plays with asoc->peer.retran_path to 1410 * avoid the problem of sending the COOKIE-ECHO and 1411 * DATA in different paths, which could result 1412 * in the association being ABORTed if the DATA chunk 1413 * is processed first by the server. Checking the 1414 * init error counter simply causes this command 1415 * to be executed only during failed attempts of 1416 * association establishment. 1417 */ 1418 if ((asoc->peer.retran_path != 1419 asoc->peer.primary_path) && 1420 (asoc->init_err_counter > 0)) { 1421 sctp_add_cmd_sf(commands, 1422 SCTP_CMD_FORCE_PRIM_RETRAN, 1423 SCTP_NULL()); 1424 } 1425 1426 break; 1427 1428 case SCTP_CMD_GEN_SHUTDOWN: 1429 /* Generate SHUTDOWN when in SHUTDOWN_SENT state. 1430 * Reset error counts. 1431 */ 1432 asoc->overall_error_count = 0; 1433 1434 /* Generate a SHUTDOWN chunk. */ 1435 new_obj = sctp_make_shutdown(asoc, chunk); 1436 if (!new_obj) 1437 goto nomem; 1438 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, 1439 SCTP_CHUNK(new_obj)); 1440 break; 1441 1442 case SCTP_CMD_CHUNK_ULP: 1443 /* Send a chunk to the sockets layer. */ 1444 pr_debug("%s: sm_sideff: chunk_up:%p, ulpq:%p\n", 1445 __func__, cmd->obj.chunk, &asoc->ulpq); 1446 1447 asoc->stream.si->ulpevent_data(&asoc->ulpq, 1448 cmd->obj.chunk, 1449 GFP_ATOMIC); 1450 break; 1451 1452 case SCTP_CMD_EVENT_ULP: 1453 /* Send a notification to the sockets layer. */ 1454 pr_debug("%s: sm_sideff: event_up:%p, ulpq:%p\n", 1455 __func__, cmd->obj.ulpevent, &asoc->ulpq); 1456 1457 asoc->stream.si->enqueue_event(&asoc->ulpq, 1458 cmd->obj.ulpevent); 1459 break; 1460 1461 case SCTP_CMD_REPLY: 1462 /* If an caller has not already corked, do cork. */ 1463 if (!asoc->outqueue.cork) { 1464 sctp_outq_cork(&asoc->outqueue); 1465 local_cork = 1; 1466 } 1467 /* Send a chunk to our peer. */ 1468 sctp_outq_tail(&asoc->outqueue, cmd->obj.chunk, gfp); 1469 break; 1470 1471 case SCTP_CMD_SEND_PKT: 1472 /* Send a full packet to our peer. */ 1473 packet = cmd->obj.packet; 1474 sctp_packet_transmit(packet, gfp); 1475 sctp_ootb_pkt_free(packet); 1476 break; 1477 1478 case SCTP_CMD_T1_RETRAN: 1479 /* Mark a transport for retransmission. */ 1480 sctp_retransmit(&asoc->outqueue, cmd->obj.transport, 1481 SCTP_RTXR_T1_RTX); 1482 break; 1483 1484 case SCTP_CMD_RETRAN: 1485 /* Mark a transport for retransmission. */ 1486 sctp_retransmit(&asoc->outqueue, cmd->obj.transport, 1487 SCTP_RTXR_T3_RTX); 1488 break; 1489 1490 case SCTP_CMD_ECN_CE: 1491 /* Do delayed CE processing. */ 1492 sctp_do_ecn_ce_work(asoc, cmd->obj.u32); 1493 break; 1494 1495 case SCTP_CMD_ECN_ECNE: 1496 /* Do delayed ECNE processing. */ 1497 new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32, 1498 chunk); 1499 if (new_obj) 1500 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, 1501 SCTP_CHUNK(new_obj)); 1502 break; 1503 1504 case SCTP_CMD_ECN_CWR: 1505 /* Do delayed CWR processing. */ 1506 sctp_do_ecn_cwr_work(asoc, cmd->obj.u32); 1507 break; 1508 1509 case SCTP_CMD_SETUP_T2: 1510 sctp_cmd_setup_t2(commands, asoc, cmd->obj.chunk); 1511 break; 1512 1513 case SCTP_CMD_TIMER_START_ONCE: 1514 timer = &asoc->timers[cmd->obj.to]; 1515 1516 if (timer_pending(timer)) 1517 break; 1518 /* fall through */ 1519 1520 case SCTP_CMD_TIMER_START: 1521 timer = &asoc->timers[cmd->obj.to]; 1522 timeout = asoc->timeouts[cmd->obj.to]; 1523 BUG_ON(!timeout); 1524 1525 timer->expires = jiffies + timeout; 1526 sctp_association_hold(asoc); 1527 add_timer(timer); 1528 break; 1529 1530 case SCTP_CMD_TIMER_RESTART: 1531 timer = &asoc->timers[cmd->obj.to]; 1532 timeout = asoc->timeouts[cmd->obj.to]; 1533 if (!mod_timer(timer, jiffies + timeout)) 1534 sctp_association_hold(asoc); 1535 break; 1536 1537 case SCTP_CMD_TIMER_STOP: 1538 timer = &asoc->timers[cmd->obj.to]; 1539 if (del_timer(timer)) 1540 sctp_association_put(asoc); 1541 break; 1542 1543 case SCTP_CMD_INIT_CHOOSE_TRANSPORT: 1544 chunk = cmd->obj.chunk; 1545 t = sctp_assoc_choose_alter_transport(asoc, 1546 asoc->init_last_sent_to); 1547 asoc->init_last_sent_to = t; 1548 chunk->transport = t; 1549 t->init_sent_count++; 1550 /* Set the new transport as primary */ 1551 sctp_assoc_set_primary(asoc, t); 1552 break; 1553 1554 case SCTP_CMD_INIT_RESTART: 1555 /* Do the needed accounting and updates 1556 * associated with restarting an initialization 1557 * timer. Only multiply the timeout by two if 1558 * all transports have been tried at the current 1559 * timeout. 1560 */ 1561 sctp_cmd_t1_timer_update(asoc, 1562 SCTP_EVENT_TIMEOUT_T1_INIT, 1563 "INIT"); 1564 1565 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART, 1566 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT)); 1567 break; 1568 1569 case SCTP_CMD_COOKIEECHO_RESTART: 1570 /* Do the needed accounting and updates 1571 * associated with restarting an initialization 1572 * timer. Only multiply the timeout by two if 1573 * all transports have been tried at the current 1574 * timeout. 1575 */ 1576 sctp_cmd_t1_timer_update(asoc, 1577 SCTP_EVENT_TIMEOUT_T1_COOKIE, 1578 "COOKIE"); 1579 1580 /* If we've sent any data bundled with 1581 * COOKIE-ECHO we need to resend. 1582 */ 1583 list_for_each_entry(t, &asoc->peer.transport_addr_list, 1584 transports) { 1585 sctp_retransmit_mark(&asoc->outqueue, t, 1586 SCTP_RTXR_T1_RTX); 1587 } 1588 1589 sctp_add_cmd_sf(commands, 1590 SCTP_CMD_TIMER_RESTART, 1591 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE)); 1592 break; 1593 1594 case SCTP_CMD_INIT_FAILED: 1595 sctp_cmd_init_failed(commands, asoc, cmd->obj.u32); 1596 break; 1597 1598 case SCTP_CMD_ASSOC_FAILED: 1599 sctp_cmd_assoc_failed(commands, asoc, event_type, 1600 subtype, chunk, cmd->obj.u32); 1601 break; 1602 1603 case SCTP_CMD_INIT_COUNTER_INC: 1604 asoc->init_err_counter++; 1605 break; 1606 1607 case SCTP_CMD_INIT_COUNTER_RESET: 1608 asoc->init_err_counter = 0; 1609 asoc->init_cycle = 0; 1610 list_for_each_entry(t, &asoc->peer.transport_addr_list, 1611 transports) { 1612 t->init_sent_count = 0; 1613 } 1614 break; 1615 1616 case SCTP_CMD_REPORT_DUP: 1617 sctp_tsnmap_mark_dup(&asoc->peer.tsn_map, 1618 cmd->obj.u32); 1619 break; 1620 1621 case SCTP_CMD_REPORT_BAD_TAG: 1622 pr_debug("%s: vtag mismatch!\n", __func__); 1623 break; 1624 1625 case SCTP_CMD_STRIKE: 1626 /* Mark one strike against a transport. */ 1627 sctp_do_8_2_transport_strike(commands, asoc, 1628 cmd->obj.transport, 0); 1629 break; 1630 1631 case SCTP_CMD_TRANSPORT_IDLE: 1632 t = cmd->obj.transport; 1633 sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE); 1634 break; 1635 1636 case SCTP_CMD_TRANSPORT_HB_SENT: 1637 t = cmd->obj.transport; 1638 sctp_do_8_2_transport_strike(commands, asoc, 1639 t, 1); 1640 t->hb_sent = 1; 1641 break; 1642 1643 case SCTP_CMD_TRANSPORT_ON: 1644 t = cmd->obj.transport; 1645 sctp_cmd_transport_on(commands, asoc, t, chunk); 1646 break; 1647 1648 case SCTP_CMD_HB_TIMERS_START: 1649 sctp_cmd_hb_timers_start(commands, asoc); 1650 break; 1651 1652 case SCTP_CMD_HB_TIMER_UPDATE: 1653 t = cmd->obj.transport; 1654 sctp_transport_reset_hb_timer(t); 1655 break; 1656 1657 case SCTP_CMD_HB_TIMERS_STOP: 1658 sctp_cmd_hb_timers_stop(commands, asoc); 1659 break; 1660 1661 case SCTP_CMD_REPORT_ERROR: 1662 error = cmd->obj.error; 1663 break; 1664 1665 case SCTP_CMD_PROCESS_CTSN: 1666 /* Dummy up a SACK for processing. */ 1667 sackh.cum_tsn_ack = cmd->obj.be32; 1668 sackh.a_rwnd = htonl(asoc->peer.rwnd + 1669 asoc->outqueue.outstanding_bytes); 1670 sackh.num_gap_ack_blocks = 0; 1671 sackh.num_dup_tsns = 0; 1672 chunk->subh.sack_hdr = &sackh; 1673 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, 1674 SCTP_CHUNK(chunk)); 1675 break; 1676 1677 case SCTP_CMD_DISCARD_PACKET: 1678 /* We need to discard the whole packet. 1679 * Uncork the queue since there might be 1680 * responses pending 1681 */ 1682 chunk->pdiscard = 1; 1683 if (asoc) { 1684 sctp_outq_uncork(&asoc->outqueue, gfp); 1685 local_cork = 0; 1686 } 1687 break; 1688 1689 case SCTP_CMD_RTO_PENDING: 1690 t = cmd->obj.transport; 1691 t->rto_pending = 1; 1692 break; 1693 1694 case SCTP_CMD_PART_DELIVER: 1695 asoc->stream.si->start_pd(&asoc->ulpq, GFP_ATOMIC); 1696 break; 1697 1698 case SCTP_CMD_RENEGE: 1699 asoc->stream.si->renege_events(&asoc->ulpq, 1700 cmd->obj.chunk, 1701 GFP_ATOMIC); 1702 break; 1703 1704 case SCTP_CMD_SETUP_T4: 1705 sctp_cmd_setup_t4(commands, asoc, cmd->obj.chunk); 1706 break; 1707 1708 case SCTP_CMD_PROCESS_OPERR: 1709 sctp_cmd_process_operr(commands, asoc, chunk); 1710 break; 1711 case SCTP_CMD_CLEAR_INIT_TAG: 1712 asoc->peer.i.init_tag = 0; 1713 break; 1714 case SCTP_CMD_DEL_NON_PRIMARY: 1715 sctp_cmd_del_non_primary(asoc); 1716 break; 1717 case SCTP_CMD_T3_RTX_TIMERS_STOP: 1718 sctp_cmd_t3_rtx_timers_stop(commands, asoc); 1719 break; 1720 case SCTP_CMD_FORCE_PRIM_RETRAN: 1721 t = asoc->peer.retran_path; 1722 asoc->peer.retran_path = asoc->peer.primary_path; 1723 sctp_outq_uncork(&asoc->outqueue, gfp); 1724 local_cork = 0; 1725 asoc->peer.retran_path = t; 1726 break; 1727 case SCTP_CMD_SET_SK_ERR: 1728 sctp_cmd_set_sk_err(asoc, cmd->obj.error); 1729 break; 1730 case SCTP_CMD_ASSOC_CHANGE: 1731 sctp_cmd_assoc_change(commands, asoc, 1732 cmd->obj.u8); 1733 break; 1734 case SCTP_CMD_ADAPTATION_IND: 1735 sctp_cmd_adaptation_ind(commands, asoc); 1736 break; 1737 case SCTP_CMD_PEER_NO_AUTH: 1738 sctp_cmd_peer_no_auth(commands, asoc); 1739 break; 1740 1741 case SCTP_CMD_ASSOC_SHKEY: 1742 error = sctp_auth_asoc_init_active_key(asoc, 1743 GFP_ATOMIC); 1744 break; 1745 case SCTP_CMD_UPDATE_INITTAG: 1746 asoc->peer.i.init_tag = cmd->obj.u32; 1747 break; 1748 case SCTP_CMD_SEND_MSG: 1749 if (!asoc->outqueue.cork) { 1750 sctp_outq_cork(&asoc->outqueue); 1751 local_cork = 1; 1752 } 1753 sctp_cmd_send_msg(asoc, cmd->obj.msg, gfp); 1754 break; 1755 case SCTP_CMD_PURGE_ASCONF_QUEUE: 1756 sctp_asconf_queue_teardown(asoc); 1757 break; 1758 1759 case SCTP_CMD_SET_ASOC: 1760 if (asoc && local_cork) { 1761 sctp_outq_uncork(&asoc->outqueue, gfp); 1762 local_cork = 0; 1763 } 1764 asoc = cmd->obj.asoc; 1765 break; 1766 1767 default: 1768 pr_warn("Impossible command: %u\n", 1769 cmd->verb); 1770 break; 1771 } 1772 1773 if (error) 1774 break; 1775 } 1776 1777 out: 1778 /* If this is in response to a received chunk, wait until 1779 * we are done with the packet to open the queue so that we don't 1780 * send multiple packets in response to a single request. 1781 */ 1782 if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) { 1783 if (chunk->end_of_packet || chunk->singleton) 1784 sctp_outq_uncork(&asoc->outqueue, gfp); 1785 } else if (local_cork) 1786 sctp_outq_uncork(&asoc->outqueue, gfp); 1787 1788 if (sp->data_ready_signalled) 1789 sp->data_ready_signalled = 0; 1790 1791 return error; 1792 nomem: 1793 error = -ENOMEM; 1794 goto out; 1795 } 1796