1 /* SCTP kernel reference Implementation
2 * Copyright (c) 1999 Cisco, Inc.
3 * Copyright (c) 1999-2001 Motorola, Inc.
4 * Copyright (c) 2001-2002 International Business Machines Corp.
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_t5_shutdown_guard_event(unsigned long data
)
299 struct sctp_association
*asoc
= (struct sctp_association
*)data
;
300 sctp_generate_timeout_event(asoc
,
301 SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
);
303 } /* sctp_generate_t5_shutdown_guard_event() */
305 void sctp_generate_autoclose_event(unsigned long data
)
307 struct sctp_association
*asoc
= (struct sctp_association
*) data
;
308 sctp_generate_timeout_event(asoc
, SCTP_EVENT_TIMEOUT_AUTOCLOSE
);
311 /* Generate a heart beat event. If the sock is busy, reschedule. Make
312 * sure that the transport is still valid.
314 void sctp_generate_heartbeat_event(unsigned long data
)
317 struct sctp_transport
*transport
= (struct sctp_transport
*) data
;
318 struct sctp_association
*asoc
= transport
->asoc
;
320 sctp_bh_lock_sock(asoc
->base
.sk
);
321 if (sock_owned_by_user(asoc
->base
.sk
)) {
322 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __FUNCTION__
);
324 /* Try again later. */
325 if (!mod_timer(&transport
->hb_timer
, jiffies
+ (HZ
/20)))
326 sctp_transport_hold(transport
);
330 /* Is this structure just waiting around for us to actually
336 error
= sctp_do_sm(SCTP_EVENT_T_TIMEOUT
,
337 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT
),
338 asoc
->state
, asoc
->ep
, asoc
,
339 transport
, GFP_ATOMIC
);
342 asoc
->base
.sk
->sk_err
= -error
;
345 sctp_bh_unlock_sock(asoc
->base
.sk
);
346 sctp_transport_put(transport
);
349 /* Inject a SACK Timeout event into the state machine. */
350 void sctp_generate_sack_event(unsigned long data
)
352 struct sctp_association
*asoc
= (struct sctp_association
*) data
;
353 sctp_generate_timeout_event(asoc
, SCTP_EVENT_TIMEOUT_SACK
);
356 sctp_timer_event_t
*sctp_timer_events
[SCTP_NUM_TIMEOUT_TYPES
] = {
358 sctp_generate_t1_cookie_event
,
359 sctp_generate_t1_init_event
,
360 sctp_generate_t2_shutdown_event
,
362 sctp_generate_t5_shutdown_guard_event
,
363 sctp_generate_heartbeat_event
,
364 sctp_generate_sack_event
,
365 sctp_generate_autoclose_event
,
369 /* RFC 2960 8.2 Path Failure Detection
371 * When its peer endpoint is multi-homed, an endpoint should keep a
372 * error counter for each of the destination transport addresses of the
375 * Each time the T3-rtx timer expires on any address, or when a
376 * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
377 * the error counter of that destination address will be incremented.
378 * When the value in the error counter exceeds the protocol parameter
379 * 'Path.Max.Retrans' of that destination address, the endpoint should
380 * mark the destination transport address as inactive, and a
381 * notification SHOULD be sent to the upper layer.
384 static void sctp_do_8_2_transport_strike(struct sctp_association
*asoc
,
385 struct sctp_transport
*transport
)
387 /* The check for association's overall error counter exceeding the
388 * threshold is done in the state function.
390 asoc
->overall_error_count
++;
392 if (transport
->active
&&
393 (transport
->error_count
++ >= transport
->error_threshold
)) {
394 SCTP_DEBUG_PRINTK("transport_strike: transport "
395 "IP:%d.%d.%d.%d failed.\n",
396 NIPQUAD(transport
->ipaddr
.v4
.sin_addr
));
397 sctp_assoc_control_transport(asoc
, transport
,
399 SCTP_FAILED_THRESHOLD
);
402 /* E2) For the destination address for which the timer
403 * expires, set RTO <- RTO * 2 ("back off the timer"). The
404 * maximum value discussed in rule C7 above (RTO.max) may be
405 * used to provide an upper bound to this doubling operation.
407 transport
->rto
= min((transport
->rto
* 2), transport
->asoc
->rto_max
);
410 /* Worker routine to handle INIT command failure. */
411 static void sctp_cmd_init_failed(sctp_cmd_seq_t
*commands
,
412 struct sctp_association
*asoc
,
415 struct sctp_ulpevent
*event
;
417 event
= sctp_ulpevent_make_assoc_change(asoc
,0, SCTP_CANT_STR_ASSOC
,
422 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
423 SCTP_ULPEVENT(event
));
425 /* SEND_FAILED sent later when cleaning up the association. */
426 asoc
->outqueue
.error
= error
;
427 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
430 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED. */
431 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t
*commands
,
432 struct sctp_association
*asoc
,
433 sctp_event_t event_type
,
434 sctp_subtype_t subtype
,
435 struct sctp_chunk
*chunk
,
438 struct sctp_ulpevent
*event
;
440 /* Cancel any partial delivery in progress. */
441 sctp_ulpq_abort_pd(&asoc
->ulpq
, GFP_ATOMIC
);
443 event
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_COMM_LOST
,
447 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
448 SCTP_ULPEVENT(event
));
450 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
451 SCTP_STATE(SCTP_STATE_CLOSED
));
453 /* SEND_FAILED sent later when cleaning up the association. */
454 asoc
->outqueue
.error
= error
;
455 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
458 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
459 * inside the cookie. In reality, this is only used for INIT-ACK processing
460 * since all other cases use "temporary" associations and can do all
461 * their work in statefuns directly.
463 static int sctp_cmd_process_init(sctp_cmd_seq_t
*commands
,
464 struct sctp_association
*asoc
,
465 struct sctp_chunk
*chunk
,
466 sctp_init_chunk_t
*peer_init
, int gfp
)
470 /* We only process the init as a sideeffect in a single
471 * case. This is when we process the INIT-ACK. If we
472 * fail during INIT processing (due to malloc problems),
473 * just return the error and stop processing the stack.
475 if (!sctp_process_init(asoc
, chunk
->chunk_hdr
->type
,
476 sctp_source(chunk
), peer_init
, gfp
))
484 /* Helper function to break out starting up of heartbeat timers. */
485 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t
*cmds
,
486 struct sctp_association
*asoc
)
488 struct sctp_transport
*t
;
489 struct list_head
*pos
;
491 /* Start a heartbeat timer for each transport on the association.
492 * hold a reference on the transport to make sure none of
493 * the needed data structures go away.
495 list_for_each(pos
, &asoc
->peer
.transport_addr_list
) {
496 t
= list_entry(pos
, struct sctp_transport
, transports
);
498 if (!mod_timer(&t
->hb_timer
, sctp_transport_timeout(t
)))
499 sctp_transport_hold(t
);
503 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t
*cmds
,
504 struct sctp_association
*asoc
)
506 struct sctp_transport
*t
;
507 struct list_head
*pos
;
509 /* Stop all heartbeat timers. */
511 list_for_each(pos
, &asoc
->peer
.transport_addr_list
) {
512 t
= list_entry(pos
, struct sctp_transport
, transports
);
513 if (del_timer(&t
->hb_timer
))
514 sctp_transport_put(t
);
518 /* Helper function to update the heartbeat timer. */
519 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t
*cmds
,
520 struct sctp_association
*asoc
,
521 struct sctp_transport
*t
)
523 /* Update the heartbeat timer. */
524 if (!mod_timer(&t
->hb_timer
, sctp_transport_timeout(t
)))
525 sctp_transport_hold(t
);
528 /* Helper function to handle the reception of an HEARTBEAT ACK. */
529 static void sctp_cmd_transport_on(sctp_cmd_seq_t
*cmds
,
530 struct sctp_association
*asoc
,
531 struct sctp_transport
*t
,
532 struct sctp_chunk
*chunk
)
534 sctp_sender_hb_info_t
*hbinfo
;
536 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
537 * HEARTBEAT should clear the error counter of the destination
538 * transport address to which the HEARTBEAT was sent.
539 * The association's overall error count is also cleared.
542 t
->asoc
->overall_error_count
= 0;
544 /* Mark the destination transport address as active if it is not so
548 sctp_assoc_control_transport(asoc
, t
, SCTP_TRANSPORT_UP
,
549 SCTP_HEARTBEAT_SUCCESS
);
551 /* The receiver of the HEARTBEAT ACK should also perform an
552 * RTT measurement for that destination transport address
553 * using the time value carried in the HEARTBEAT ACK chunk.
555 hbinfo
= (sctp_sender_hb_info_t
*) chunk
->skb
->data
;
556 sctp_transport_update_rto(t
, (jiffies
- hbinfo
->sent_at
));
559 /* Helper function to do a transport reset at the expiry of the hearbeat
562 static void sctp_cmd_transport_reset(sctp_cmd_seq_t
*cmds
,
563 struct sctp_association
*asoc
,
564 struct sctp_transport
*t
)
566 sctp_transport_lower_cwnd(t
, SCTP_LOWER_CWND_INACTIVE
);
568 /* Mark one strike against a transport. */
569 sctp_do_8_2_transport_strike(asoc
, t
);
572 /* Helper function to process the process SACK command. */
573 static int sctp_cmd_process_sack(sctp_cmd_seq_t
*cmds
,
574 struct sctp_association
*asoc
,
575 sctp_sackhdr_t
*sackh
)
579 if (sctp_outq_sack(&asoc
->outqueue
, sackh
)) {
580 /* There are no more TSNs awaiting SACK. */
581 err
= sctp_do_sm(SCTP_EVENT_T_OTHER
,
582 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN
),
583 asoc
->state
, asoc
->ep
, asoc
, NULL
,
586 /* Windows may have opened, so we need
587 * to check if we have DATA to transmit
589 err
= sctp_outq_flush(&asoc
->outqueue
, 0);
595 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
596 * the transport for a shutdown chunk.
598 static void sctp_cmd_setup_t2(sctp_cmd_seq_t
*cmds
,
599 struct sctp_association
*asoc
,
600 struct sctp_chunk
*chunk
)
602 struct sctp_transport
*t
;
604 t
= sctp_assoc_choose_shutdown_transport(asoc
);
605 asoc
->shutdown_last_sent_to
= t
;
606 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
] = t
->rto
;
607 chunk
->transport
= t
;
610 /* Helper function to change the state of an association. */
611 static void sctp_cmd_new_state(sctp_cmd_seq_t
*cmds
,
612 struct sctp_association
*asoc
,
615 struct sock
*sk
= asoc
->base
.sk
;
619 if (sctp_style(sk
, TCP
)) {
620 /* Change the sk->sk_state of a TCP-style socket that has
621 * sucessfully completed a connect() call.
623 if (sctp_state(asoc
, ESTABLISHED
) && sctp_sstate(sk
, CLOSED
))
624 sk
->sk_state
= SCTP_SS_ESTABLISHED
;
626 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
627 if (sctp_state(asoc
, SHUTDOWN_RECEIVED
) &&
628 sctp_sstate(sk
, ESTABLISHED
))
629 sk
->sk_shutdown
|= RCV_SHUTDOWN
;
632 if (sctp_state(asoc
, ESTABLISHED
) ||
633 sctp_state(asoc
, CLOSED
) ||
634 sctp_state(asoc
, SHUTDOWN_RECEIVED
)) {
635 /* Wake up any processes waiting in the asoc's wait queue in
636 * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
638 if (waitqueue_active(&asoc
->wait
))
639 wake_up_interruptible(&asoc
->wait
);
641 /* Wake up any processes waiting in the sk's sleep queue of
642 * a TCP-style or UDP-style peeled-off socket in
643 * sctp_wait_for_accept() or sctp_wait_for_packet().
644 * For a UDP-style socket, the waiters are woken up by the
647 if (!sctp_style(sk
, UDP
))
648 sk
->sk_state_change(sk
);
652 /* Helper function to delete an association. */
653 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t
*cmds
,
654 struct sctp_association
*asoc
)
656 struct sock
*sk
= asoc
->base
.sk
;
658 /* If it is a non-temporary association belonging to a TCP-style
659 * listening socket, do not free it so that accept() can pick it
662 if (sctp_style(sk
, TCP
) && sctp_sstate(sk
, LISTENING
) && (!asoc
->temp
))
665 sctp_unhash_established(asoc
);
666 sctp_association_free(asoc
);
669 /* These three macros allow us to pull the debugging code out of the
670 * main flow of sctp_do_sm() to keep attention focused on the real
671 * functionality there.
674 SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
675 "ep %p, %s, %s, asoc %p[%s], %s\n", \
676 ep, sctp_evttype_tbl[event_type], \
677 (*debug_fn)(subtype), asoc, \
678 sctp_state_tbl[state], state_fn->name)
681 SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
682 "asoc %p, status: %s\n", \
683 asoc, sctp_status_tbl[status])
685 #define DEBUG_POST_SFX \
686 SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
688 sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
689 sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
692 * This is the master state machine processing function.
694 * If you want to understand all of lksctp, this is a
695 * good place to start.
697 int sctp_do_sm(sctp_event_t event_type
, sctp_subtype_t subtype
,
699 struct sctp_endpoint
*ep
,
700 struct sctp_association
*asoc
,
704 sctp_cmd_seq_t commands
;
705 const sctp_sm_table_entry_t
*state_fn
;
706 sctp_disposition_t status
;
708 typedef const char *(printfn_t
)(sctp_subtype_t
);
710 static printfn_t
*table
[] = {
711 NULL
, sctp_cname
, sctp_tname
, sctp_oname
, sctp_pname
,
713 printfn_t
*debug_fn
__attribute__ ((unused
)) = table
[event_type
];
715 /* Look up the state function, run it, and then process the
716 * side effects. These three steps are the heart of lksctp.
718 state_fn
= sctp_sm_lookup_event(event_type
, state
, subtype
);
720 sctp_init_cmd_seq(&commands
);
723 status
= (*state_fn
->fn
)(ep
, asoc
, subtype
, event_arg
, &commands
);
726 error
= sctp_side_effects(event_type
, subtype
, state
,
727 ep
, asoc
, event_arg
, status
,
737 /*****************************************************************
738 * This the master state function side effect processing function.
739 *****************************************************************/
740 int sctp_side_effects(sctp_event_t event_type
, sctp_subtype_t subtype
,
742 struct sctp_endpoint
*ep
,
743 struct sctp_association
*asoc
,
745 sctp_disposition_t status
,
746 sctp_cmd_seq_t
*commands
,
751 /* FIXME - Most of the dispositions left today would be categorized
752 * as "exceptional" dispositions. For those dispositions, it
753 * may not be proper to run through any of the commands at all.
754 * For example, the command interpreter might be run only with
755 * disposition SCTP_DISPOSITION_CONSUME.
757 if (0 != (error
= sctp_cmd_interpreter(event_type
, subtype
, state
,
764 case SCTP_DISPOSITION_DISCARD
:
765 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
766 "event_type %d, event_id %d\n",
767 state
, event_type
, subtype
.chunk
);
770 case SCTP_DISPOSITION_NOMEM
:
771 /* We ran out of memory, so we need to discard this
774 /* BUG--we should now recover some memory, probably by
780 case SCTP_DISPOSITION_DELETE_TCB
:
781 /* This should now be a command. */
784 case SCTP_DISPOSITION_CONSUME
:
785 case SCTP_DISPOSITION_ABORT
:
787 * We should no longer have much work to do here as the
788 * real work has been done as explicit commands above.
792 case SCTP_DISPOSITION_VIOLATION
:
793 printk(KERN_ERR
"sctp protocol violation state %d "
794 "chunkid %d\n", state
, subtype
.chunk
);
797 case SCTP_DISPOSITION_NOT_IMPL
:
798 printk(KERN_WARNING
"sctp unimplemented feature in state %d, "
799 "event_type %d, event_id %d\n",
800 state
, event_type
, subtype
.chunk
);
803 case SCTP_DISPOSITION_BUG
:
804 printk(KERN_ERR
"sctp bug in state %d, "
805 "event_type %d, event_id %d\n",
806 state
, event_type
, subtype
.chunk
);
811 printk(KERN_ERR
"sctp impossible disposition %d "
812 "in state %d, event_type %d, event_id %d\n",
813 status
, state
, event_type
, subtype
.chunk
);
822 /********************************************************************
823 * 2nd Level Abstractions
824 ********************************************************************/
826 /* This is the side-effect interpreter. */
827 int sctp_cmd_interpreter(sctp_event_t event_type
, sctp_subtype_t subtype
,
828 sctp_state_t state
, struct sctp_endpoint
*ep
,
829 struct sctp_association
*asoc
, void *event_arg
,
830 sctp_disposition_t status
, sctp_cmd_seq_t
*commands
,
836 struct sctp_chunk
*new_obj
;
837 struct sctp_chunk
*chunk
= NULL
;
838 struct sctp_packet
*packet
;
839 struct list_head
*pos
;
840 struct timer_list
*timer
;
841 unsigned long timeout
;
842 struct sctp_transport
*t
;
843 sctp_sackhdr_t sackh
;
846 if (SCTP_EVENT_T_TIMEOUT
!= event_type
)
847 chunk
= (struct sctp_chunk
*) event_arg
;
849 /* Note: This whole file is a huge candidate for rework.
850 * For example, each command could either have its own handler, so
851 * the loop would look like:
853 * cmd->handle(x, y, z)
856 while (NULL
!= (cmd
= sctp_next_cmd(commands
))) {
862 case SCTP_CMD_NEW_ASOC
:
863 /* Register a new association. */
865 sctp_outq_uncork(&asoc
->outqueue
);
869 /* Register with the endpoint. */
870 sctp_endpoint_add_asoc(ep
, asoc
);
871 sctp_hash_established(asoc
);
874 case SCTP_CMD_UPDATE_ASSOC
:
875 sctp_assoc_update(asoc
, cmd
->obj
.ptr
);
878 case SCTP_CMD_PURGE_OUTQUEUE
:
879 sctp_outq_teardown(&asoc
->outqueue
);
882 case SCTP_CMD_DELETE_TCB
:
884 sctp_outq_uncork(&asoc
->outqueue
);
887 /* Delete the current association. */
888 sctp_cmd_delete_tcb(commands
, asoc
);
892 case SCTP_CMD_NEW_STATE
:
893 /* Enter a new state. */
894 sctp_cmd_new_state(commands
, asoc
, cmd
->obj
.state
);
897 case SCTP_CMD_REPORT_TSN
:
898 /* Record the arrival of a TSN. */
899 sctp_tsnmap_mark(&asoc
->peer
.tsn_map
, cmd
->obj
.u32
);
902 case SCTP_CMD_GEN_SACK
:
903 /* Generate a Selective ACK.
904 * The argument tells us whether to just count
905 * the packet and MAYBE generate a SACK, or
908 force
= cmd
->obj
.i32
;
909 error
= sctp_gen_sack(asoc
, force
, commands
);
912 case SCTP_CMD_PROCESS_SACK
:
913 /* Process an inbound SACK. */
914 error
= sctp_cmd_process_sack(commands
, asoc
,
918 case SCTP_CMD_GEN_INIT_ACK
:
919 /* Generate an INIT ACK chunk. */
920 new_obj
= sctp_make_init_ack(asoc
, chunk
, GFP_ATOMIC
,
925 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
926 SCTP_CHUNK(new_obj
));
929 case SCTP_CMD_PEER_INIT
:
930 /* Process a unified INIT from the peer.
931 * Note: Only used during INIT-ACK processing. If
932 * there is an error just return to the outter
933 * layer which will bail.
935 error
= sctp_cmd_process_init(commands
, asoc
, chunk
,
939 case SCTP_CMD_GEN_COOKIE_ECHO
:
940 /* Generate a COOKIE ECHO chunk. */
941 new_obj
= sctp_make_cookie_echo(asoc
, chunk
);
944 sctp_chunk_free(cmd
->obj
.ptr
);
947 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
948 SCTP_CHUNK(new_obj
));
950 /* If there is an ERROR chunk to be sent along with
951 * the COOKIE_ECHO, send it, too.
954 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
955 SCTP_CHUNK(cmd
->obj
.ptr
));
958 case SCTP_CMD_GEN_SHUTDOWN
:
959 /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
960 * Reset error counts.
962 asoc
->overall_error_count
= 0;
964 /* Generate a SHUTDOWN chunk. */
965 new_obj
= sctp_make_shutdown(asoc
);
968 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
969 SCTP_CHUNK(new_obj
));
972 case SCTP_CMD_CHUNK_ULP
:
973 /* Send a chunk to the sockets layer. */
974 SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
975 "chunk_up:", cmd
->obj
.ptr
,
976 "ulpq:", &asoc
->ulpq
);
977 sctp_ulpq_tail_data(&asoc
->ulpq
, cmd
->obj
.ptr
,
981 case SCTP_CMD_EVENT_ULP
:
982 /* Send a notification to the sockets layer. */
983 SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
984 "event_up:",cmd
->obj
.ptr
,
985 "ulpq:",&asoc
->ulpq
);
986 sctp_ulpq_tail_event(&asoc
->ulpq
, cmd
->obj
.ptr
);
990 /* If an caller has not already corked, do cork. */
991 if (!asoc
->outqueue
.cork
) {
992 sctp_outq_cork(&asoc
->outqueue
);
995 /* Send a chunk to our peer. */
996 error
= sctp_outq_tail(&asoc
->outqueue
, cmd
->obj
.ptr
);
999 case SCTP_CMD_SEND_PKT
:
1000 /* Send a full packet to our peer. */
1001 packet
= cmd
->obj
.ptr
;
1002 sctp_packet_transmit(packet
);
1003 sctp_ootb_pkt_free(packet
);
1006 case SCTP_CMD_RETRAN
:
1007 /* Mark a transport for retransmission. */
1008 sctp_retransmit(&asoc
->outqueue
, cmd
->obj
.transport
,
1012 case SCTP_CMD_TRANSMIT
:
1013 /* Kick start transmission. */
1014 error
= sctp_outq_uncork(&asoc
->outqueue
);
1018 case SCTP_CMD_ECN_CE
:
1019 /* Do delayed CE processing. */
1020 sctp_do_ecn_ce_work(asoc
, cmd
->obj
.u32
);
1023 case SCTP_CMD_ECN_ECNE
:
1024 /* Do delayed ECNE processing. */
1025 new_obj
= sctp_do_ecn_ecne_work(asoc
, cmd
->obj
.u32
,
1028 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
1029 SCTP_CHUNK(new_obj
));
1032 case SCTP_CMD_ECN_CWR
:
1033 /* Do delayed CWR processing. */
1034 sctp_do_ecn_cwr_work(asoc
, cmd
->obj
.u32
);
1037 case SCTP_CMD_SETUP_T2
:
1038 sctp_cmd_setup_t2(commands
, asoc
, cmd
->obj
.ptr
);
1041 case SCTP_CMD_TIMER_START
:
1042 timer
= &asoc
->timers
[cmd
->obj
.to
];
1043 timeout
= asoc
->timeouts
[cmd
->obj
.to
];
1047 timer
->expires
= jiffies
+ timeout
;
1048 sctp_association_hold(asoc
);
1052 case SCTP_CMD_TIMER_RESTART
:
1053 timer
= &asoc
->timers
[cmd
->obj
.to
];
1054 timeout
= asoc
->timeouts
[cmd
->obj
.to
];
1055 if (!mod_timer(timer
, jiffies
+ timeout
))
1056 sctp_association_hold(asoc
);
1059 case SCTP_CMD_TIMER_STOP
:
1060 timer
= &asoc
->timers
[cmd
->obj
.to
];
1061 if (timer_pending(timer
) && del_timer(timer
))
1062 sctp_association_put(asoc
);
1065 case SCTP_CMD_INIT_RESTART
:
1066 /* Do the needed accounting and updates
1067 * associated with restarting an initialization
1070 asoc
->counters
[SCTP_COUNTER_INIT_ERROR
]++;
1071 asoc
->timeouts
[cmd
->obj
.to
] *= 2;
1072 if (asoc
->timeouts
[cmd
->obj
.to
] >
1073 asoc
->max_init_timeo
) {
1074 asoc
->timeouts
[cmd
->obj
.to
] =
1075 asoc
->max_init_timeo
;
1078 /* If we've sent any data bundled with
1079 * COOKIE-ECHO we need to resend.
1081 list_for_each(pos
, &asoc
->peer
.transport_addr_list
) {
1082 t
= list_entry(pos
, struct sctp_transport
,
1084 sctp_retransmit_mark(&asoc
->outqueue
, t
, 0);
1087 sctp_add_cmd_sf(commands
,
1088 SCTP_CMD_TIMER_RESTART
,
1089 SCTP_TO(cmd
->obj
.to
));
1092 case SCTP_CMD_INIT_FAILED
:
1093 sctp_cmd_init_failed(commands
, asoc
, cmd
->obj
.u32
);
1096 case SCTP_CMD_ASSOC_FAILED
:
1097 sctp_cmd_assoc_failed(commands
, asoc
, event_type
,
1098 subtype
, chunk
, cmd
->obj
.u32
);
1101 case SCTP_CMD_COUNTER_INC
:
1102 asoc
->counters
[cmd
->obj
.counter
]++;
1105 case SCTP_CMD_COUNTER_RESET
:
1106 asoc
->counters
[cmd
->obj
.counter
] = 0;
1109 case SCTP_CMD_REPORT_DUP
:
1110 sctp_tsnmap_mark_dup(&asoc
->peer
.tsn_map
,
1114 case SCTP_CMD_REPORT_BAD_TAG
:
1115 SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1118 case SCTP_CMD_STRIKE
:
1119 /* Mark one strike against a transport. */
1120 sctp_do_8_2_transport_strike(asoc
, cmd
->obj
.transport
);
1123 case SCTP_CMD_TRANSPORT_RESET
:
1124 t
= cmd
->obj
.transport
;
1125 sctp_cmd_transport_reset(commands
, asoc
, t
);
1128 case SCTP_CMD_TRANSPORT_ON
:
1129 t
= cmd
->obj
.transport
;
1130 sctp_cmd_transport_on(commands
, asoc
, t
, chunk
);
1133 case SCTP_CMD_HB_TIMERS_START
:
1134 sctp_cmd_hb_timers_start(commands
, asoc
);
1137 case SCTP_CMD_HB_TIMER_UPDATE
:
1138 t
= cmd
->obj
.transport
;
1139 sctp_cmd_hb_timer_update(commands
, asoc
, t
);
1142 case SCTP_CMD_HB_TIMERS_STOP
:
1143 sctp_cmd_hb_timers_stop(commands
, asoc
);
1146 case SCTP_CMD_REPORT_ERROR
:
1147 error
= cmd
->obj
.error
;
1150 case SCTP_CMD_PROCESS_CTSN
:
1151 /* Dummy up a SACK for processing. */
1152 sackh
.cum_tsn_ack
= cmd
->obj
.u32
;
1154 sackh
.num_gap_ack_blocks
= 0;
1155 sackh
.num_dup_tsns
= 0;
1156 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_SACK
,
1157 SCTP_SACKH(&sackh
));
1160 case SCTP_CMD_DISCARD_PACKET
:
1161 /* We need to discard the whole packet. */
1162 chunk
->pdiscard
= 1;
1165 case SCTP_CMD_RTO_PENDING
:
1166 t
= cmd
->obj
.transport
;
1170 case SCTP_CMD_PART_DELIVER
:
1171 sctp_ulpq_partial_delivery(&asoc
->ulpq
, cmd
->obj
.ptr
,
1175 case SCTP_CMD_RENEGE
:
1176 sctp_ulpq_renege(&asoc
->ulpq
, cmd
->obj
.ptr
,
1181 printk(KERN_WARNING
"Impossible command: %u, %p\n",
1182 cmd
->verb
, cmd
->obj
.ptr
);
1191 sctp_outq_uncork(&asoc
->outqueue
);