1 /* SCTP kernel reference Implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
6 * This file is part of the SCTP kernel reference Implementation
8 * These functions work with the state functions in sctp_sm_statefuns.c
9 * to implement that state operations. These functions implement the
10 * steps which require modifying existing data structures.
12 * The SCTP reference implementation is free software;
13 * you can redistribute it and/or modify it under the terms of
14 * the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
18 * The SCTP reference implementation is distributed in the hope that it
19 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
20 * ************************
21 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22 * See the GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with GNU CC; see the file COPYING. If not, write to
26 * the Free Software Foundation, 59 Temple Place - Suite 330,
27 * Boston, MA 02111-1307, USA.
29 * Please send any bug reports or fixes you make to the
31 * lksctp developers <lksctp-developers@lists.sourceforge.net>
33 * Or submit a bug report through the following website:
34 * http://www.sf.net/projects/lksctp
36 * Written or modified by:
37 * La Monte H.P. Yarroll <piggy@acm.org>
38 * Karl Knutson <karl@athena.chicago.il.us>
39 * Jon Grimm <jgrimm@austin.ibm.com>
40 * Hui Huang <hui.huang@nokia.com>
41 * Dajiang Zhang <dajiang.zhang@nokia.com>
42 * Daisy Chang <daisyc@us.ibm.com>
43 * Sridhar Samudrala <sri@us.ibm.com>
44 * Ardelle Fan <ardelle.fan@intel.com>
46 * Any bugs reported given to us we will try to fix... any fixes shared will
47 * be incorporated into the next SCTP release.
50 #include <linux/skbuff.h>
51 #include <linux/types.h>
52 #include <linux/socket.h>
55 #include <net/sctp/sctp.h>
56 #include <net/sctp/sm.h>
58 /********************************************************************
60 ********************************************************************/
62 /* A helper function for delayed processing of INET ECN CE bit. */
63 static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
66 /* Save the TSN away for comparison when we receive CWR */
68 asoc->last_ecne_tsn = lowest_tsn;
72 /* Helper function for delayed processing of SCTP ECNE chunk. */
73 /* RFC 2960 Appendix A
75 * RFC 2481 details a specific bit for a sender to send in
76 * the header of its next outbound TCP segment to indicate to
77 * its peer that it has reduced its congestion window. This
78 * is termed the CWR bit. For SCTP the same indication is made
79 * by including the CWR chunk. This chunk contains one data
80 * element, i.e. the TSN number that was sent in the ECNE chunk.
81 * This element represents the lowest TSN number in the datagram
82 * that was originally marked with the CE bit.
84 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
86 struct sctp_chunk *chunk)
88 struct sctp_chunk *repl;
90 /* Our previously transmitted packet ran into some congestion
91 * so we should take action by reducing cwnd and ssthresh
92 * and then ACK our peer that we we've done so by
96 /* First, try to determine if we want to actually lower
97 * our cwnd variables. Only lower them if the ECNE looks more
98 * recent than the last response.
100 if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
101 struct sctp_transport *transport;
103 /* Find which transport's congestion variables
104 * need to be adjusted.
106 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
108 /* Update the congestion variables. */
110 sctp_transport_lower_cwnd(transport,
111 SCTP_LOWER_CWND_ECNE);
112 asoc->last_cwr_tsn = lowest_tsn;
115 /* Always try to quiet the other end. In case of lost CWR,
116 * resend last_cwr_tsn.
118 repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
120 /* If we run out of memory, it will look like a lost CWR. We'll
121 * get back in sync eventually.
126 /* Helper function to do delayed processing of ECN CWR chunk. */
127 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
130 /* Turn off ECNE getting auto-prepended to every outgoing
136 /* Generate SACK if necessary. We call this at the end of a packet. */
137 int sctp_gen_sack(struct sctp_association *asoc, int force,
138 sctp_cmd_seq_t *commands)
140 __u32 ctsn, max_tsn_seen;
141 struct sctp_chunk *sack;
145 asoc->peer.sack_needed = 1;
147 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
148 max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
150 /* From 12.2 Parameters necessary per association (i.e. the TCB):
152 * Ack State : This flag indicates if the next received packet
153 * : is to be responded to with a SACK. ...
154 * : When DATA chunks are out of order, SACK's
155 * : are not delayed (see Section 6).
157 * [This is actually not mentioned in Section 6, but we
158 * implement it here anyway. --piggy]
160 if (max_tsn_seen != ctsn)
161 asoc->peer.sack_needed = 1;
163 /* From 6.2 Acknowledgement on Reception of DATA Chunks:
165 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
166 * an acknowledgement SHOULD be generated for at least every
167 * second packet (not every second DATA chunk) received, and
168 * SHOULD be generated within 200 ms of the arrival of any
169 * unacknowledged DATA chunk. ...
171 if (!asoc->peer.sack_needed) {
172 /* We will need a SACK for the next packet. */
173 asoc->peer.sack_needed = 1;
176 if (asoc->a_rwnd > asoc->rwnd)
177 asoc->a_rwnd = asoc->rwnd;
178 sack = sctp_make_sack(asoc);
182 asoc->peer.sack_needed = 0;
184 error = sctp_outq_tail(&asoc->outqueue, sack);
186 /* Stop the SACK timer. */
187 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
188 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
197 /* When the T3-RTX timer expires, it calls this function to create the
198 * relevant state machine event.
200 void sctp_generate_t3_rtx_event(unsigned long peer)
203 struct sctp_transport *transport = (struct sctp_transport *) peer;
204 struct sctp_association *asoc = transport->asoc;
206 /* Check whether a task is in the sock. */
208 sctp_bh_lock_sock(asoc->base.sk);
209 if (sock_owned_by_user(asoc->base.sk)) {
210 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __FUNCTION__);
212 /* Try again later. */
213 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
214 sctp_transport_hold(transport);
218 /* Is this transport really dead and just waiting around for
219 * the timer to let go of the reference?
224 /* Run through the state machine. */
225 error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
226 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
229 transport, GFP_ATOMIC);
232 asoc->base.sk->sk_err = -error;
235 sctp_bh_unlock_sock(asoc->base.sk);
236 sctp_transport_put(transport);
239 /* This is a sa interface for producing timeout events. It works
240 * for timeouts which use the association as their parameter.
242 static void sctp_generate_timeout_event(struct sctp_association *asoc,
243 sctp_event_timeout_t timeout_type)
247 sctp_bh_lock_sock(asoc->base.sk);
248 if (sock_owned_by_user(asoc->base.sk)) {
249 SCTP_DEBUG_PRINTK("%s:Sock is busy: timer %d\n",
253 /* Try again later. */
254 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
255 sctp_association_hold(asoc);
259 /* Is this association really dead and just waiting around for
260 * the timer to let go of the reference?
265 /* Run through the state machine. */
266 error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
267 SCTP_ST_TIMEOUT(timeout_type),
268 asoc->state, asoc->ep, asoc,
269 (void *)timeout_type, GFP_ATOMIC);
272 asoc->base.sk->sk_err = -error;
275 sctp_bh_unlock_sock(asoc->base.sk);
276 sctp_association_put(asoc);
279 void sctp_generate_t1_cookie_event(unsigned long data)
281 struct sctp_association *asoc = (struct sctp_association *) data;
282 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
285 void sctp_generate_t1_init_event(unsigned long data)
287 struct sctp_association *asoc = (struct sctp_association *) data;
288 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
291 void sctp_generate_t2_shutdown_event(unsigned long data)
293 struct sctp_association *asoc = (struct sctp_association *) data;
294 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
297 void sctp_generate_t4_rto_event(unsigned long data)
299 struct sctp_association *asoc = (struct sctp_association *) data;
300 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
303 void sctp_generate_t5_shutdown_guard_event(unsigned long data)
305 struct sctp_association *asoc = (struct sctp_association *)data;
306 sctp_generate_timeout_event(asoc,
307 SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
309 } /* sctp_generate_t5_shutdown_guard_event() */
311 void sctp_generate_autoclose_event(unsigned long data)
313 struct sctp_association *asoc = (struct sctp_association *) data;
314 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
317 /* Generate a heart beat event. If the sock is busy, reschedule. Make
318 * sure that the transport is still valid.
320 void sctp_generate_heartbeat_event(unsigned long data)
323 struct sctp_transport *transport = (struct sctp_transport *) data;
324 struct sctp_association *asoc = transport->asoc;
326 sctp_bh_lock_sock(asoc->base.sk);
327 if (sock_owned_by_user(asoc->base.sk)) {
328 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __FUNCTION__);
330 /* Try again later. */
331 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
332 sctp_transport_hold(transport);
336 /* Is this structure just waiting around for us to actually
342 error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
343 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
344 asoc->state, asoc->ep, asoc,
345 transport, GFP_ATOMIC);
348 asoc->base.sk->sk_err = -error;
351 sctp_bh_unlock_sock(asoc->base.sk);
352 sctp_transport_put(transport);
355 /* Inject a SACK Timeout event into the state machine. */
356 void sctp_generate_sack_event(unsigned long data)
358 struct sctp_association *asoc = (struct sctp_association *) data;
359 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
362 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
364 sctp_generate_t1_cookie_event,
365 sctp_generate_t1_init_event,
366 sctp_generate_t2_shutdown_event,
368 sctp_generate_t4_rto_event,
369 sctp_generate_t5_shutdown_guard_event,
370 sctp_generate_heartbeat_event,
371 sctp_generate_sack_event,
372 sctp_generate_autoclose_event,
376 /* RFC 2960 8.2 Path Failure Detection
378 * When its peer endpoint is multi-homed, an endpoint should keep a
379 * error counter for each of the destination transport addresses of the
382 * Each time the T3-rtx timer expires on any address, or when a
383 * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
384 * the error counter of that destination address will be incremented.
385 * When the value in the error counter exceeds the protocol parameter
386 * 'Path.Max.Retrans' of that destination address, the endpoint should
387 * mark the destination transport address as inactive, and a
388 * notification SHOULD be sent to the upper layer.
391 static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
392 struct sctp_transport *transport)
394 /* The check for association's overall error counter exceeding the
395 * threshold is done in the state function.
397 asoc->overall_error_count++;
399 if (transport->active &&
400 (transport->error_count++ >= transport->error_threshold)) {
401 SCTP_DEBUG_PRINTK("transport_strike: transport "
402 "IP:%d.%d.%d.%d failed.\n",
403 NIPQUAD(transport->ipaddr.v4.sin_addr));
404 sctp_assoc_control_transport(asoc, transport,
406 SCTP_FAILED_THRESHOLD);
409 /* E2) For the destination address for which the timer
410 * expires, set RTO <- RTO * 2 ("back off the timer"). The
411 * maximum value discussed in rule C7 above (RTO.max) may be
412 * used to provide an upper bound to this doubling operation.
414 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
417 /* Worker routine to handle INIT command failure. */
418 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
419 struct sctp_association *asoc,
422 struct sctp_ulpevent *event;
424 event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
429 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
430 SCTP_ULPEVENT(event));
432 /* SEND_FAILED sent later when cleaning up the association. */
433 asoc->outqueue.error = error;
434 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
437 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED. */
438 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
439 struct sctp_association *asoc,
440 sctp_event_t event_type,
441 sctp_subtype_t subtype,
442 struct sctp_chunk *chunk,
445 struct sctp_ulpevent *event;
447 /* Cancel any partial delivery in progress. */
448 sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
450 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
454 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
455 SCTP_ULPEVENT(event));
457 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
458 SCTP_STATE(SCTP_STATE_CLOSED));
460 /* SEND_FAILED sent later when cleaning up the association. */
461 asoc->outqueue.error = error;
462 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
465 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
466 * inside the cookie. In reality, this is only used for INIT-ACK processing
467 * since all other cases use "temporary" associations and can do all
468 * their work in statefuns directly.
470 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
471 struct sctp_association *asoc,
472 struct sctp_chunk *chunk,
473 sctp_init_chunk_t *peer_init, int gfp)
477 /* We only process the init as a sideeffect in a single
478 * case. This is when we process the INIT-ACK. If we
479 * fail during INIT processing (due to malloc problems),
480 * just return the error and stop processing the stack.
482 if (!sctp_process_init(asoc, chunk->chunk_hdr->type,
483 sctp_source(chunk), peer_init, gfp))
491 /* Helper function to break out starting up of heartbeat timers. */
492 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
493 struct sctp_association *asoc)
495 struct sctp_transport *t;
496 struct list_head *pos;
498 /* Start a heartbeat timer for each transport on the association.
499 * hold a reference on the transport to make sure none of
500 * the needed data structures go away.
502 list_for_each(pos, &asoc->peer.transport_addr_list) {
503 t = list_entry(pos, struct sctp_transport, transports);
505 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
506 sctp_transport_hold(t);
510 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
511 struct sctp_association *asoc)
513 struct sctp_transport *t;
514 struct list_head *pos;
516 /* Stop all heartbeat timers. */
518 list_for_each(pos, &asoc->peer.transport_addr_list) {
519 t = list_entry(pos, struct sctp_transport, transports);
520 if (del_timer(&t->hb_timer))
521 sctp_transport_put(t);
525 /* Helper function to update the heartbeat timer. */
526 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
527 struct sctp_association *asoc,
528 struct sctp_transport *t)
530 /* Update the heartbeat timer. */
531 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
532 sctp_transport_hold(t);
535 /* Helper function to handle the reception of an HEARTBEAT ACK. */
536 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
537 struct sctp_association *asoc,
538 struct sctp_transport *t,
539 struct sctp_chunk *chunk)
541 sctp_sender_hb_info_t *hbinfo;
543 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
544 * HEARTBEAT should clear the error counter of the destination
545 * transport address to which the HEARTBEAT was sent.
546 * The association's overall error count is also cleared.
549 t->asoc->overall_error_count = 0;
551 /* Mark the destination transport address as active if it is not so
555 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
556 SCTP_HEARTBEAT_SUCCESS);
558 /* The receiver of the HEARTBEAT ACK should also perform an
559 * RTT measurement for that destination transport address
560 * using the time value carried in the HEARTBEAT ACK chunk.
562 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
563 sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
566 /* Helper function to do a transport reset at the expiry of the hearbeat
569 static void sctp_cmd_transport_reset(sctp_cmd_seq_t *cmds,
570 struct sctp_association *asoc,
571 struct sctp_transport *t)
573 sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
575 /* Mark one strike against a transport. */
576 sctp_do_8_2_transport_strike(asoc, t);
579 /* Helper function to process the process SACK command. */
580 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
581 struct sctp_association *asoc,
582 struct sctp_sackhdr *sackh)
586 if (sctp_outq_sack(&asoc->outqueue, sackh)) {
587 /* There are no more TSNs awaiting SACK. */
588 err = sctp_do_sm(SCTP_EVENT_T_OTHER,
589 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
590 asoc->state, asoc->ep, asoc, NULL,
593 /* Windows may have opened, so we need
594 * to check if we have DATA to transmit
596 err = sctp_outq_flush(&asoc->outqueue, 0);
602 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
603 * the transport for a shutdown chunk.
605 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
606 struct sctp_association *asoc,
607 struct sctp_chunk *chunk)
609 struct sctp_transport *t;
611 t = sctp_assoc_choose_shutdown_transport(asoc);
612 asoc->shutdown_last_sent_to = t;
613 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
614 chunk->transport = t;
617 /* Helper function to change the state of an association. */
618 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
619 struct sctp_association *asoc,
622 struct sock *sk = asoc->base.sk;
626 if (sctp_style(sk, TCP)) {
627 /* Change the sk->sk_state of a TCP-style socket that has
628 * sucessfully completed a connect() call.
630 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
631 sk->sk_state = SCTP_SS_ESTABLISHED;
633 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
634 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
635 sctp_sstate(sk, ESTABLISHED))
636 sk->sk_shutdown |= RCV_SHUTDOWN;
639 if (sctp_state(asoc, ESTABLISHED) ||
640 sctp_state(asoc, CLOSED) ||
641 sctp_state(asoc, SHUTDOWN_RECEIVED)) {
642 /* Wake up any processes waiting in the asoc's wait queue in
643 * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
645 if (waitqueue_active(&asoc->wait))
646 wake_up_interruptible(&asoc->wait);
648 /* Wake up any processes waiting in the sk's sleep queue of
649 * a TCP-style or UDP-style peeled-off socket in
650 * sctp_wait_for_accept() or sctp_wait_for_packet().
651 * For a UDP-style socket, the waiters are woken up by the
654 if (!sctp_style(sk, UDP))
655 sk->sk_state_change(sk);
659 /* Helper function to delete an association. */
660 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
661 struct sctp_association *asoc)
663 struct sock *sk = asoc->base.sk;
665 /* If it is a non-temporary association belonging to a TCP-style
666 * listening socket that is not closed, do not free it so that accept()
667 * can pick it up later.
669 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
670 (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
673 sctp_unhash_established(asoc);
674 sctp_association_free(asoc);
678 * ADDIP Section 4.1 ASCONF Chunk Procedures
679 * A4) Start a T-4 RTO timer, using the RTO value of the selected
680 * destination address (we use active path instead of primary path just
681 * because primary path may be inactive.
683 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
684 struct sctp_association *asoc,
685 struct sctp_chunk *chunk)
687 struct sctp_transport *t;
689 t = asoc->peer.active_path;
690 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
691 chunk->transport = t;
694 /* Process an incoming Operation Error Chunk. */
695 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
696 struct sctp_association *asoc,
697 struct sctp_chunk *chunk)
699 struct sctp_operr_chunk *operr_chunk;
700 struct sctp_errhdr *err_hdr;
702 operr_chunk = (struct sctp_operr_chunk *)chunk->chunk_hdr;
703 err_hdr = &operr_chunk->err_hdr;
705 switch (err_hdr->cause) {
706 case SCTP_ERROR_UNKNOWN_CHUNK:
708 struct sctp_chunkhdr *unk_chunk_hdr;
710 unk_chunk_hdr = (struct sctp_chunkhdr *)err_hdr->variable;
711 switch (unk_chunk_hdr->type) {
712 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with an
713 * ERROR chunk reporting that it did not recognized the ASCONF
714 * chunk type, the sender of the ASCONF MUST NOT send any
715 * further ASCONF chunks and MUST stop its T-4 timer.
717 case SCTP_CID_ASCONF:
718 asoc->peer.asconf_capable = 0;
719 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
720 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
732 /* Process variable FWDTSN chunk information. */
733 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
734 struct sctp_chunk *chunk)
736 struct sctp_fwdtsn_skip *skip;
737 /* Walk through all the skipped SSNs */
738 sctp_walk_fwdtsn(skip, chunk) {
739 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
745 /* These three macros allow us to pull the debugging code out of the
746 * main flow of sctp_do_sm() to keep attention focused on the real
747 * functionality there.
750 SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
751 "ep %p, %s, %s, asoc %p[%s], %s\n", \
752 ep, sctp_evttype_tbl[event_type], \
753 (*debug_fn)(subtype), asoc, \
754 sctp_state_tbl[state], state_fn->name)
757 SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
758 "asoc %p, status: %s\n", \
759 asoc, sctp_status_tbl[status])
761 #define DEBUG_POST_SFX \
762 SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
764 sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
765 sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
768 * This is the master state machine processing function.
770 * If you want to understand all of lksctp, this is a
771 * good place to start.
773 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
775 struct sctp_endpoint *ep,
776 struct sctp_association *asoc,
780 sctp_cmd_seq_t commands;
781 const sctp_sm_table_entry_t *state_fn;
782 sctp_disposition_t status;
784 typedef const char *(printfn_t)(sctp_subtype_t);
786 static printfn_t *table[] = {
787 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
789 printfn_t *debug_fn __attribute__ ((unused)) = table[event_type];
791 /* Look up the state function, run it, and then process the
792 * side effects. These three steps are the heart of lksctp.
794 state_fn = sctp_sm_lookup_event(event_type, state, subtype);
796 sctp_init_cmd_seq(&commands);
799 status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
802 error = sctp_side_effects(event_type, subtype, state,
803 ep, asoc, event_arg, status,
813 /*****************************************************************
814 * This the master state function side effect processing function.
815 *****************************************************************/
816 int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
818 struct sctp_endpoint *ep,
819 struct sctp_association *asoc,
821 sctp_disposition_t status,
822 sctp_cmd_seq_t *commands,
827 /* FIXME - Most of the dispositions left today would be categorized
828 * as "exceptional" dispositions. For those dispositions, it
829 * may not be proper to run through any of the commands at all.
830 * For example, the command interpreter might be run only with
831 * disposition SCTP_DISPOSITION_CONSUME.
833 if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
840 case SCTP_DISPOSITION_DISCARD:
841 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
842 "event_type %d, event_id %d\n",
843 state, event_type, subtype.chunk);
846 case SCTP_DISPOSITION_NOMEM:
847 /* We ran out of memory, so we need to discard this
850 /* BUG--we should now recover some memory, probably by
856 case SCTP_DISPOSITION_DELETE_TCB:
857 /* This should now be a command. */
860 case SCTP_DISPOSITION_CONSUME:
861 case SCTP_DISPOSITION_ABORT:
863 * We should no longer have much work to do here as the
864 * real work has been done as explicit commands above.
868 case SCTP_DISPOSITION_VIOLATION:
869 printk(KERN_ERR "sctp protocol violation state %d "
870 "chunkid %d\n", state, subtype.chunk);
873 case SCTP_DISPOSITION_NOT_IMPL:
874 printk(KERN_WARNING "sctp unimplemented feature in state %d, "
875 "event_type %d, event_id %d\n",
876 state, event_type, subtype.chunk);
879 case SCTP_DISPOSITION_BUG:
880 printk(KERN_ERR "sctp bug in state %d, "
881 "event_type %d, event_id %d\n",
882 state, event_type, subtype.chunk);
887 printk(KERN_ERR "sctp impossible disposition %d "
888 "in state %d, event_type %d, event_id %d\n",
889 status, state, event_type, subtype.chunk);
898 /********************************************************************
899 * 2nd Level Abstractions
900 ********************************************************************/
902 /* This is the side-effect interpreter. */
903 int sctp_cmd_interpreter(sctp_event_t event_type, sctp_subtype_t subtype,
904 sctp_state_t state, struct sctp_endpoint *ep,
905 struct sctp_association *asoc, void *event_arg,
906 sctp_disposition_t status, sctp_cmd_seq_t *commands,
912 struct sctp_chunk *new_obj;
913 struct sctp_chunk *chunk = NULL;
914 struct sctp_packet *packet;
915 struct list_head *pos;
916 struct timer_list *timer;
917 unsigned long timeout;
918 struct sctp_transport *t;
919 struct sctp_sackhdr sackh;
922 if (SCTP_EVENT_T_TIMEOUT != event_type)
923 chunk = (struct sctp_chunk *) event_arg;
925 /* Note: This whole file is a huge candidate for rework.
926 * For example, each command could either have its own handler, so
927 * the loop would look like:
929 * cmd->handle(x, y, z)
932 while (NULL != (cmd = sctp_next_cmd(commands))) {
938 case SCTP_CMD_NEW_ASOC:
939 /* Register a new association. */
941 sctp_outq_uncork(&asoc->outqueue);
945 /* Register with the endpoint. */
946 sctp_endpoint_add_asoc(ep, asoc);
947 sctp_hash_established(asoc);
950 case SCTP_CMD_UPDATE_ASSOC:
951 sctp_assoc_update(asoc, cmd->obj.ptr);
954 case SCTP_CMD_PURGE_OUTQUEUE:
955 sctp_outq_teardown(&asoc->outqueue);
958 case SCTP_CMD_DELETE_TCB:
960 sctp_outq_uncork(&asoc->outqueue);
963 /* Delete the current association. */
964 sctp_cmd_delete_tcb(commands, asoc);
968 case SCTP_CMD_NEW_STATE:
969 /* Enter a new state. */
970 sctp_cmd_new_state(commands, asoc, cmd->obj.state);
973 case SCTP_CMD_REPORT_TSN:
974 /* Record the arrival of a TSN. */
975 sctp_tsnmap_mark(&asoc->peer.tsn_map, cmd->obj.u32);
978 case SCTP_CMD_REPORT_FWDTSN:
979 /* Move the Cumulattive TSN Ack ahead. */
980 sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
982 /* Abort any in progress partial delivery. */
983 sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
986 case SCTP_CMD_PROCESS_FWDTSN:
987 sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
990 case SCTP_CMD_GEN_SACK:
991 /* Generate a Selective ACK.
992 * The argument tells us whether to just count
993 * the packet and MAYBE generate a SACK, or
996 force = cmd->obj.i32;
997 error = sctp_gen_sack(asoc, force, commands);
1000 case SCTP_CMD_PROCESS_SACK:
1001 /* Process an inbound SACK. */
1002 error = sctp_cmd_process_sack(commands, asoc,
1006 case SCTP_CMD_GEN_INIT_ACK:
1007 /* Generate an INIT ACK chunk. */
1008 new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1013 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1014 SCTP_CHUNK(new_obj));
1017 case SCTP_CMD_PEER_INIT:
1018 /* Process a unified INIT from the peer.
1019 * Note: Only used during INIT-ACK processing. If
1020 * there is an error just return to the outter
1021 * layer which will bail.
1023 error = sctp_cmd_process_init(commands, asoc, chunk,
1027 case SCTP_CMD_GEN_COOKIE_ECHO:
1028 /* Generate a COOKIE ECHO chunk. */
1029 new_obj = sctp_make_cookie_echo(asoc, chunk);
1032 sctp_chunk_free(cmd->obj.ptr);
1035 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1036 SCTP_CHUNK(new_obj));
1038 /* If there is an ERROR chunk to be sent along with
1039 * the COOKIE_ECHO, send it, too.
1042 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1043 SCTP_CHUNK(cmd->obj.ptr));
1046 case SCTP_CMD_GEN_SHUTDOWN:
1047 /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1048 * Reset error counts.
1050 asoc->overall_error_count = 0;
1052 /* Generate a SHUTDOWN chunk. */
1053 new_obj = sctp_make_shutdown(asoc, chunk);
1056 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1057 SCTP_CHUNK(new_obj));
1060 case SCTP_CMD_CHUNK_ULP:
1061 /* Send a chunk to the sockets layer. */
1062 SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1063 "chunk_up:", cmd->obj.ptr,
1064 "ulpq:", &asoc->ulpq);
1065 sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1069 case SCTP_CMD_EVENT_ULP:
1070 /* Send a notification to the sockets layer. */
1071 SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1072 "event_up:",cmd->obj.ptr,
1073 "ulpq:",&asoc->ulpq);
1074 sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1077 case SCTP_CMD_REPLY:
1078 /* If an caller has not already corked, do cork. */
1079 if (!asoc->outqueue.cork) {
1080 sctp_outq_cork(&asoc->outqueue);
1083 /* Send a chunk to our peer. */
1084 error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1087 case SCTP_CMD_SEND_PKT:
1088 /* Send a full packet to our peer. */
1089 packet = cmd->obj.ptr;
1090 sctp_packet_transmit(packet);
1091 sctp_ootb_pkt_free(packet);
1094 case SCTP_CMD_RETRAN:
1095 /* Mark a transport for retransmission. */
1096 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1100 case SCTP_CMD_TRANSMIT:
1101 /* Kick start transmission. */
1102 error = sctp_outq_uncork(&asoc->outqueue);
1106 case SCTP_CMD_ECN_CE:
1107 /* Do delayed CE processing. */
1108 sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1111 case SCTP_CMD_ECN_ECNE:
1112 /* Do delayed ECNE processing. */
1113 new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1116 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1117 SCTP_CHUNK(new_obj));
1120 case SCTP_CMD_ECN_CWR:
1121 /* Do delayed CWR processing. */
1122 sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1125 case SCTP_CMD_SETUP_T2:
1126 sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1129 case SCTP_CMD_TIMER_START:
1130 timer = &asoc->timers[cmd->obj.to];
1131 timeout = asoc->timeouts[cmd->obj.to];
1135 timer->expires = jiffies + timeout;
1136 sctp_association_hold(asoc);
1140 case SCTP_CMD_TIMER_RESTART:
1141 timer = &asoc->timers[cmd->obj.to];
1142 timeout = asoc->timeouts[cmd->obj.to];
1143 if (!mod_timer(timer, jiffies + timeout))
1144 sctp_association_hold(asoc);
1147 case SCTP_CMD_TIMER_STOP:
1148 timer = &asoc->timers[cmd->obj.to];
1149 if (timer_pending(timer) && del_timer(timer))
1150 sctp_association_put(asoc);
1153 case SCTP_CMD_INIT_RESTART:
1154 /* Do the needed accounting and updates
1155 * associated with restarting an initialization
1158 asoc->counters[SCTP_COUNTER_INIT_ERROR]++;
1159 asoc->timeouts[cmd->obj.to] *= 2;
1160 if (asoc->timeouts[cmd->obj.to] >
1161 asoc->max_init_timeo) {
1162 asoc->timeouts[cmd->obj.to] =
1163 asoc->max_init_timeo;
1166 /* If we've sent any data bundled with
1167 * COOKIE-ECHO we need to resend.
1169 list_for_each(pos, &asoc->peer.transport_addr_list) {
1170 t = list_entry(pos, struct sctp_transport,
1172 sctp_retransmit_mark(&asoc->outqueue, t, 0);
1175 sctp_add_cmd_sf(commands,
1176 SCTP_CMD_TIMER_RESTART,
1177 SCTP_TO(cmd->obj.to));
1180 case SCTP_CMD_INIT_FAILED:
1181 sctp_cmd_init_failed(commands, asoc, cmd->obj.u32);
1184 case SCTP_CMD_ASSOC_FAILED:
1185 sctp_cmd_assoc_failed(commands, asoc, event_type,
1186 subtype, chunk, cmd->obj.u32);
1189 case SCTP_CMD_COUNTER_INC:
1190 asoc->counters[cmd->obj.counter]++;
1193 case SCTP_CMD_COUNTER_RESET:
1194 asoc->counters[cmd->obj.counter] = 0;
1197 case SCTP_CMD_REPORT_DUP:
1198 sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1202 case SCTP_CMD_REPORT_BAD_TAG:
1203 SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1206 case SCTP_CMD_STRIKE:
1207 /* Mark one strike against a transport. */
1208 sctp_do_8_2_transport_strike(asoc, cmd->obj.transport);
1211 case SCTP_CMD_TRANSPORT_RESET:
1212 t = cmd->obj.transport;
1213 sctp_cmd_transport_reset(commands, asoc, t);
1216 case SCTP_CMD_TRANSPORT_ON:
1217 t = cmd->obj.transport;
1218 sctp_cmd_transport_on(commands, asoc, t, chunk);
1221 case SCTP_CMD_HB_TIMERS_START:
1222 sctp_cmd_hb_timers_start(commands, asoc);
1225 case SCTP_CMD_HB_TIMER_UPDATE:
1226 t = cmd->obj.transport;
1227 sctp_cmd_hb_timer_update(commands, asoc, t);
1230 case SCTP_CMD_HB_TIMERS_STOP:
1231 sctp_cmd_hb_timers_stop(commands, asoc);
1234 case SCTP_CMD_REPORT_ERROR:
1235 error = cmd->obj.error;
1238 case SCTP_CMD_PROCESS_CTSN:
1239 /* Dummy up a SACK for processing. */
1240 sackh.cum_tsn_ack = cmd->obj.u32;
1242 sackh.num_gap_ack_blocks = 0;
1243 sackh.num_dup_tsns = 0;
1244 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1245 SCTP_SACKH(&sackh));
1248 case SCTP_CMD_DISCARD_PACKET:
1249 /* We need to discard the whole packet. */
1250 chunk->pdiscard = 1;
1253 case SCTP_CMD_RTO_PENDING:
1254 t = cmd->obj.transport;
1258 case SCTP_CMD_PART_DELIVER:
1259 sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1263 case SCTP_CMD_RENEGE:
1264 sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1268 case SCTP_CMD_SETUP_T4:
1269 sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1272 case SCTP_CMD_PROCESS_OPERR:
1273 sctp_cmd_process_operr(commands, asoc, chunk);
1276 printk(KERN_WARNING "Impossible command: %u, %p\n",
1277 cmd->verb, cmd->obj.ptr);
1286 sctp_outq_uncork(&asoc->outqueue);