xref: /openbmc/linux/net/sctp/sm_sideeffect.c (revision 87c2ce3b)
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.
5  *
6  * This file is part of the SCTP kernel reference Implementation
7  *
8  * These functions work with the state functions in sctp_sm_statefuns.c
9  * to implement that state operations.  These functions implement the
10  * steps which require modifying existing data structures.
11  *
12  * 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)
16  * any later version.
17  *
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.
23  *
24  * You should have received a copy of the GNU General Public License
25  * along with GNU CC; see the file COPYING.  If not, write to
26  * the Free Software Foundation, 59 Temple Place - Suite 330,
27  * Boston, MA 02111-1307, USA.
28  *
29  * Please send any bug reports or fixes you make to the
30  * email address(es):
31  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
32  *
33  * Or submit a bug report through the following website:
34  *    http://www.sf.net/projects/lksctp
35  *
36  * Written or modified by:
37  *    La Monte H.P. Yarroll <piggy@acm.org>
38  *    Karl Knutson          <karl@athena.chicago.il.us>
39  *    Jon Grimm             <jgrimm@austin.ibm.com>
40  *    Hui Huang		    <hui.huang@nokia.com>
41  *    Dajiang Zhang	    <dajiang.zhang@nokia.com>
42  *    Daisy Chang	    <daisyc@us.ibm.com>
43  *    Sridhar Samudrala	    <sri@us.ibm.com>
44  *    Ardelle Fan	    <ardelle.fan@intel.com>
45  *
46  * Any bugs reported given to us we will try to fix... any fixes shared will
47  * be incorporated into the next SCTP release.
48  */
49 
50 #include <linux/skbuff.h>
51 #include <linux/types.h>
52 #include <linux/socket.h>
53 #include <linux/ip.h>
54 #include <net/sock.h>
55 #include <net/sctp/sctp.h>
56 #include <net/sctp/sm.h>
57 
58 static int sctp_cmd_interpreter(sctp_event_t event_type,
59 				sctp_subtype_t subtype,
60 				sctp_state_t state,
61 				struct sctp_endpoint *ep,
62 				struct sctp_association *asoc,
63 				void *event_arg,
64 			 	sctp_disposition_t status,
65 				sctp_cmd_seq_t *commands,
66 				gfp_t gfp);
67 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
68 			     sctp_state_t state,
69 			     struct sctp_endpoint *ep,
70 			     struct sctp_association *asoc,
71 			     void *event_arg,
72 			     sctp_disposition_t status,
73 			     sctp_cmd_seq_t *commands,
74 			     gfp_t gfp);
75 
76 /********************************************************************
77  * Helper functions
78  ********************************************************************/
79 
80 /* A helper function for delayed processing of INET ECN CE bit. */
81 static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
82 				__u32 lowest_tsn)
83 {
84 	/* Save the TSN away for comparison when we receive CWR */
85 
86 	asoc->last_ecne_tsn = lowest_tsn;
87 	asoc->need_ecne = 1;
88 }
89 
90 /* Helper function for delayed processing of SCTP ECNE chunk.  */
91 /* RFC 2960 Appendix A
92  *
93  * RFC 2481 details a specific bit for a sender to send in
94  * the header of its next outbound TCP segment to indicate to
95  * its peer that it has reduced its congestion window.  This
96  * is termed the CWR bit.  For SCTP the same indication is made
97  * by including the CWR chunk.  This chunk contains one data
98  * element, i.e. the TSN number that was sent in the ECNE chunk.
99  * This element represents the lowest TSN number in the datagram
100  * that was originally marked with the CE bit.
101  */
102 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
103 					   __u32 lowest_tsn,
104 					   struct sctp_chunk *chunk)
105 {
106 	struct sctp_chunk *repl;
107 
108 	/* Our previously transmitted packet ran into some congestion
109 	 * so we should take action by reducing cwnd and ssthresh
110 	 * and then ACK our peer that we we've done so by
111 	 * sending a CWR.
112 	 */
113 
114 	/* First, try to determine if we want to actually lower
115 	 * our cwnd variables.  Only lower them if the ECNE looks more
116 	 * recent than the last response.
117 	 */
118 	if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
119 		struct sctp_transport *transport;
120 
121 		/* Find which transport's congestion variables
122 		 * need to be adjusted.
123 		 */
124 		transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
125 
126 		/* Update the congestion variables. */
127 		if (transport)
128 			sctp_transport_lower_cwnd(transport,
129 						  SCTP_LOWER_CWND_ECNE);
130 		asoc->last_cwr_tsn = lowest_tsn;
131 	}
132 
133 	/* Always try to quiet the other end.  In case of lost CWR,
134 	 * resend last_cwr_tsn.
135 	 */
136 	repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
137 
138 	/* If we run out of memory, it will look like a lost CWR.  We'll
139 	 * get back in sync eventually.
140 	 */
141 	return repl;
142 }
143 
144 /* Helper function to do delayed processing of ECN CWR chunk.  */
145 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
146 				 __u32 lowest_tsn)
147 {
148 	/* Turn off ECNE getting auto-prepended to every outgoing
149 	 * packet
150 	 */
151 	asoc->need_ecne = 0;
152 }
153 
154 /* Generate SACK if necessary.  We call this at the end of a packet.  */
155 static int sctp_gen_sack(struct sctp_association *asoc, int force,
156 			 sctp_cmd_seq_t *commands)
157 {
158 	__u32 ctsn, max_tsn_seen;
159 	struct sctp_chunk *sack;
160 	struct sctp_transport *trans = asoc->peer.last_data_from;
161 	int error = 0;
162 
163 	if (force ||
164 	    (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
165 	    (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
166 		asoc->peer.sack_needed = 1;
167 
168 	ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
169 	max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
170 
171 	/* From 12.2 Parameters necessary per association (i.e. the TCB):
172 	 *
173 	 * Ack State : This flag indicates if the next received packet
174 	 * 	     : is to be responded to with a SACK. ...
175 	 *	     : When DATA chunks are out of order, SACK's
176 	 *           : are not delayed (see Section 6).
177 	 *
178 	 * [This is actually not mentioned in Section 6, but we
179 	 * implement it here anyway. --piggy]
180 	 */
181         if (max_tsn_seen != ctsn)
182 		asoc->peer.sack_needed = 1;
183 
184 	/* From 6.2  Acknowledgement on Reception of DATA Chunks:
185 	 *
186 	 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
187 	 * an acknowledgement SHOULD be generated for at least every
188 	 * second packet (not every second DATA chunk) received, and
189 	 * SHOULD be generated within 200 ms of the arrival of any
190 	 * unacknowledged DATA chunk. ...
191 	 */
192 	if (!asoc->peer.sack_needed) {
193 		/* We will need a SACK for the next packet.  */
194 		asoc->peer.sack_needed = 1;
195 
196 		/* Set the SACK delay timeout based on the
197 		 * SACK delay for the last transport
198 		 * data was received from, or the default
199 		 * for the association.
200 		 */
201 		if (trans)
202 			asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
203 				trans->sackdelay;
204 		else
205 			asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
206 				asoc->sackdelay;
207 
208 		/* Restart the SACK timer. */
209 		sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
210 				SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
211 	} else {
212 		if (asoc->a_rwnd > asoc->rwnd)
213 			asoc->a_rwnd = asoc->rwnd;
214 		sack = sctp_make_sack(asoc);
215 		if (!sack)
216 			goto nomem;
217 
218 		asoc->peer.sack_needed = 0;
219 
220 		error = sctp_outq_tail(&asoc->outqueue, sack);
221 
222 		/* Stop the SACK timer.  */
223 		sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
224 				SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
225 	}
226 
227 	return error;
228 nomem:
229 	error = -ENOMEM;
230 	return error;
231 }
232 
233 /* When the T3-RTX timer expires, it calls this function to create the
234  * relevant state machine event.
235  */
236 void sctp_generate_t3_rtx_event(unsigned long peer)
237 {
238 	int error;
239 	struct sctp_transport *transport = (struct sctp_transport *) peer;
240 	struct sctp_association *asoc = transport->asoc;
241 
242 	/* Check whether a task is in the sock.  */
243 
244 	sctp_bh_lock_sock(asoc->base.sk);
245 	if (sock_owned_by_user(asoc->base.sk)) {
246 		SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __FUNCTION__);
247 
248 		/* Try again later.  */
249 		if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
250 			sctp_transport_hold(transport);
251 		goto out_unlock;
252 	}
253 
254 	/* Is this transport really dead and just waiting around for
255 	 * the timer to let go of the reference?
256 	 */
257 	if (transport->dead)
258 		goto out_unlock;
259 
260 	/* Run through the state machine.  */
261 	error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
262 			   SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
263 			   asoc->state,
264 			   asoc->ep, asoc,
265 			   transport, GFP_ATOMIC);
266 
267 	if (error)
268 		asoc->base.sk->sk_err = -error;
269 
270 out_unlock:
271 	sctp_bh_unlock_sock(asoc->base.sk);
272 	sctp_transport_put(transport);
273 }
274 
275 /* This is a sa interface for producing timeout events.  It works
276  * for timeouts which use the association as their parameter.
277  */
278 static void sctp_generate_timeout_event(struct sctp_association *asoc,
279 					sctp_event_timeout_t timeout_type)
280 {
281 	int error = 0;
282 
283 	sctp_bh_lock_sock(asoc->base.sk);
284 	if (sock_owned_by_user(asoc->base.sk)) {
285 		SCTP_DEBUG_PRINTK("%s:Sock is busy: timer %d\n",
286 				  __FUNCTION__,
287 				  timeout_type);
288 
289 		/* Try again later.  */
290 		if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
291 			sctp_association_hold(asoc);
292 		goto out_unlock;
293 	}
294 
295 	/* Is this association really dead and just waiting around for
296 	 * the timer to let go of the reference?
297 	 */
298 	if (asoc->base.dead)
299 		goto out_unlock;
300 
301 	/* Run through the state machine.  */
302 	error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
303 			   SCTP_ST_TIMEOUT(timeout_type),
304 			   asoc->state, asoc->ep, asoc,
305 			   (void *)timeout_type, GFP_ATOMIC);
306 
307 	if (error)
308 		asoc->base.sk->sk_err = -error;
309 
310 out_unlock:
311 	sctp_bh_unlock_sock(asoc->base.sk);
312 	sctp_association_put(asoc);
313 }
314 
315 static void sctp_generate_t1_cookie_event(unsigned long data)
316 {
317 	struct sctp_association *asoc = (struct sctp_association *) data;
318 	sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
319 }
320 
321 static void sctp_generate_t1_init_event(unsigned long data)
322 {
323 	struct sctp_association *asoc = (struct sctp_association *) data;
324 	sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
325 }
326 
327 static void sctp_generate_t2_shutdown_event(unsigned long data)
328 {
329 	struct sctp_association *asoc = (struct sctp_association *) data;
330 	sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
331 }
332 
333 static void sctp_generate_t4_rto_event(unsigned long data)
334 {
335 	struct sctp_association *asoc = (struct sctp_association *) data;
336 	sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
337 }
338 
339 static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
340 {
341         struct sctp_association *asoc = (struct sctp_association *)data;
342         sctp_generate_timeout_event(asoc,
343 				    SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
344 
345 } /* sctp_generate_t5_shutdown_guard_event() */
346 
347 static void sctp_generate_autoclose_event(unsigned long data)
348 {
349 	struct sctp_association *asoc = (struct sctp_association *) data;
350 	sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
351 }
352 
353 /* Generate a heart beat event.  If the sock is busy, reschedule.   Make
354  * sure that the transport is still valid.
355  */
356 void sctp_generate_heartbeat_event(unsigned long data)
357 {
358 	int error = 0;
359 	struct sctp_transport *transport = (struct sctp_transport *) data;
360 	struct sctp_association *asoc = transport->asoc;
361 
362 	sctp_bh_lock_sock(asoc->base.sk);
363 	if (sock_owned_by_user(asoc->base.sk)) {
364 		SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __FUNCTION__);
365 
366 		/* Try again later.  */
367 		if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
368 			sctp_transport_hold(transport);
369 		goto out_unlock;
370 	}
371 
372 	/* Is this structure just waiting around for us to actually
373 	 * get destroyed?
374 	 */
375 	if (transport->dead)
376 		goto out_unlock;
377 
378 	error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
379 			   SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
380 			   asoc->state, asoc->ep, asoc,
381 			   transport, GFP_ATOMIC);
382 
383          if (error)
384 		 asoc->base.sk->sk_err = -error;
385 
386 out_unlock:
387 	sctp_bh_unlock_sock(asoc->base.sk);
388 	sctp_transport_put(transport);
389 }
390 
391 /* Inject a SACK Timeout event into the state machine.  */
392 static void sctp_generate_sack_event(unsigned long data)
393 {
394 	struct sctp_association *asoc = (struct sctp_association *) data;
395 	sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
396 }
397 
398 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
399 	NULL,
400 	sctp_generate_t1_cookie_event,
401 	sctp_generate_t1_init_event,
402 	sctp_generate_t2_shutdown_event,
403 	NULL,
404 	sctp_generate_t4_rto_event,
405 	sctp_generate_t5_shutdown_guard_event,
406 	NULL,
407 	sctp_generate_sack_event,
408 	sctp_generate_autoclose_event,
409 };
410 
411 
412 /* RFC 2960 8.2 Path Failure Detection
413  *
414  * When its peer endpoint is multi-homed, an endpoint should keep a
415  * error counter for each of the destination transport addresses of the
416  * peer endpoint.
417  *
418  * Each time the T3-rtx timer expires on any address, or when a
419  * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
420  * the error counter of that destination address will be incremented.
421  * When the value in the error counter exceeds the protocol parameter
422  * 'Path.Max.Retrans' of that destination address, the endpoint should
423  * mark the destination transport address as inactive, and a
424  * notification SHOULD be sent to the upper layer.
425  *
426  */
427 static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
428 					 struct sctp_transport *transport)
429 {
430 	/* The check for association's overall error counter exceeding the
431 	 * threshold is done in the state function.
432 	 */
433 	asoc->overall_error_count++;
434 
435 	if (transport->state != SCTP_INACTIVE &&
436 	    (transport->error_count++ >= transport->pathmaxrxt)) {
437 		SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
438 					 " transport IP: port:%d failed.\n",
439 					 asoc,
440 					 (&transport->ipaddr),
441 					 transport->ipaddr.v4.sin_port);
442 		sctp_assoc_control_transport(asoc, transport,
443 					     SCTP_TRANSPORT_DOWN,
444 					     SCTP_FAILED_THRESHOLD);
445 	}
446 
447 	/* E2) For the destination address for which the timer
448 	 * expires, set RTO <- RTO * 2 ("back off the timer").  The
449 	 * maximum value discussed in rule C7 above (RTO.max) may be
450 	 * used to provide an upper bound to this doubling operation.
451 	 */
452 	transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
453 }
454 
455 /* Worker routine to handle INIT command failure.  */
456 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
457 				 struct sctp_association *asoc,
458 				 unsigned error)
459 {
460 	struct sctp_ulpevent *event;
461 
462 	event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
463 						(__u16)error, 0, 0,
464 						GFP_ATOMIC);
465 
466 	if (event)
467 		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
468 				SCTP_ULPEVENT(event));
469 
470 	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
471 			SCTP_STATE(SCTP_STATE_CLOSED));
472 
473 	/* SEND_FAILED sent later when cleaning up the association. */
474 	asoc->outqueue.error = error;
475 	sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
476 }
477 
478 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
479 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
480 				  struct sctp_association *asoc,
481 				  sctp_event_t event_type,
482 				  sctp_subtype_t subtype,
483 				  struct sctp_chunk *chunk,
484 				  unsigned error)
485 {
486 	struct sctp_ulpevent *event;
487 
488 	/* Cancel any partial delivery in progress. */
489 	sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
490 
491 	event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
492 						(__u16)error, 0, 0,
493 						GFP_ATOMIC);
494 	if (event)
495 		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
496 				SCTP_ULPEVENT(event));
497 
498 	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
499 			SCTP_STATE(SCTP_STATE_CLOSED));
500 
501 	/* Set sk_err to ECONNRESET on a 1-1 style socket. */
502 	if (!sctp_style(asoc->base.sk, UDP))
503 		asoc->base.sk->sk_err = ECONNRESET;
504 
505 	/* SEND_FAILED sent later when cleaning up the association. */
506 	asoc->outqueue.error = error;
507 	sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
508 }
509 
510 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
511  * inside the cookie.  In reality, this is only used for INIT-ACK processing
512  * since all other cases use "temporary" associations and can do all
513  * their work in statefuns directly.
514  */
515 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
516 				 struct sctp_association *asoc,
517 				 struct sctp_chunk *chunk,
518 				 sctp_init_chunk_t *peer_init,
519 				 gfp_t gfp)
520 {
521 	int error;
522 
523 	/* We only process the init as a sideeffect in a single
524 	 * case.   This is when we process the INIT-ACK.   If we
525 	 * fail during INIT processing (due to malloc problems),
526 	 * just return the error and stop processing the stack.
527 	 */
528 	if (!sctp_process_init(asoc, chunk->chunk_hdr->type,
529 			       sctp_source(chunk), peer_init, gfp))
530 		error = -ENOMEM;
531 	else
532 		error = 0;
533 
534 	return error;
535 }
536 
537 /* Helper function to break out starting up of heartbeat timers.  */
538 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
539 				     struct sctp_association *asoc)
540 {
541 	struct sctp_transport *t;
542 	struct list_head *pos;
543 
544 	/* Start a heartbeat timer for each transport on the association.
545 	 * hold a reference on the transport to make sure none of
546 	 * the needed data structures go away.
547 	 */
548 	list_for_each(pos, &asoc->peer.transport_addr_list) {
549 		t = list_entry(pos, struct sctp_transport, transports);
550 
551 		if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
552 			sctp_transport_hold(t);
553 	}
554 }
555 
556 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
557 				    struct sctp_association *asoc)
558 {
559 	struct sctp_transport *t;
560 	struct list_head *pos;
561 
562 	/* Stop all heartbeat timers. */
563 
564 	list_for_each(pos, &asoc->peer.transport_addr_list) {
565 		t = list_entry(pos, struct sctp_transport, transports);
566 		if (del_timer(&t->hb_timer))
567 			sctp_transport_put(t);
568 	}
569 }
570 
571 /* Helper function to stop any pending T3-RTX timers */
572 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
573 				        struct sctp_association *asoc)
574 {
575 	struct sctp_transport *t;
576 	struct list_head *pos;
577 
578 	list_for_each(pos, &asoc->peer.transport_addr_list) {
579 		t = list_entry(pos, struct sctp_transport, transports);
580 		if (timer_pending(&t->T3_rtx_timer) &&
581 		    del_timer(&t->T3_rtx_timer)) {
582 			sctp_transport_put(t);
583 		}
584 	}
585 }
586 
587 
588 /* Helper function to update the heartbeat timer. */
589 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
590 				     struct sctp_association *asoc,
591 				     struct sctp_transport *t)
592 {
593 	/* Update the heartbeat timer.  */
594 	if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
595 		sctp_transport_hold(t);
596 }
597 
598 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
599 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
600 				  struct sctp_association *asoc,
601 				  struct sctp_transport *t,
602 				  struct sctp_chunk *chunk)
603 {
604 	sctp_sender_hb_info_t *hbinfo;
605 
606 	/* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
607 	 * HEARTBEAT should clear the error counter of the destination
608 	 * transport address to which the HEARTBEAT was sent.
609 	 * The association's overall error count is also cleared.
610 	 */
611 	t->error_count = 0;
612 	t->asoc->overall_error_count = 0;
613 
614 	/* Mark the destination transport address as active if it is not so
615 	 * marked.
616 	 */
617 	if (t->state == SCTP_INACTIVE)
618 		sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
619 					     SCTP_HEARTBEAT_SUCCESS);
620 
621 	/* The receiver of the HEARTBEAT ACK should also perform an
622 	 * RTT measurement for that destination transport address
623 	 * using the time value carried in the HEARTBEAT ACK chunk.
624 	 */
625 	hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
626 	sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
627 }
628 
629 /* Helper function to do a transport reset at the expiry of the hearbeat
630  * timer.
631  */
632 static void sctp_cmd_transport_reset(sctp_cmd_seq_t *cmds,
633 				     struct sctp_association *asoc,
634 				     struct sctp_transport *t)
635 {
636 	sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
637 
638 	/* Mark one strike against a transport.  */
639 	sctp_do_8_2_transport_strike(asoc, t);
640 }
641 
642 /* Helper function to process the process SACK command.  */
643 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
644 				 struct sctp_association *asoc,
645 				 struct sctp_sackhdr *sackh)
646 {
647 	int err;
648 
649 	if (sctp_outq_sack(&asoc->outqueue, sackh)) {
650 		/* There are no more TSNs awaiting SACK.  */
651 		err = sctp_do_sm(SCTP_EVENT_T_OTHER,
652 				 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
653 				 asoc->state, asoc->ep, asoc, NULL,
654 				 GFP_ATOMIC);
655 	} else {
656 		/* Windows may have opened, so we need
657 		 * to check if we have DATA to transmit
658 		 */
659 		err = sctp_outq_flush(&asoc->outqueue, 0);
660 	}
661 
662 	return err;
663 }
664 
665 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
666  * the transport for a shutdown chunk.
667  */
668 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
669 			      struct sctp_association *asoc,
670 			      struct sctp_chunk *chunk)
671 {
672 	struct sctp_transport *t;
673 
674 	t = sctp_assoc_choose_shutdown_transport(asoc);
675 	asoc->shutdown_last_sent_to = t;
676 	asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
677 	chunk->transport = t;
678 }
679 
680 /* Helper function to change the state of an association. */
681 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
682 			       struct sctp_association *asoc,
683 			       sctp_state_t state)
684 {
685 	struct sock *sk = asoc->base.sk;
686 
687 	asoc->state = state;
688 
689 	SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
690 			  asoc, sctp_state_tbl[state]);
691 
692 	if (sctp_style(sk, TCP)) {
693 		/* Change the sk->sk_state of a TCP-style socket that has
694 		 * sucessfully completed a connect() call.
695 		 */
696 		if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
697 			sk->sk_state = SCTP_SS_ESTABLISHED;
698 
699 		/* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
700 		if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
701 		    sctp_sstate(sk, ESTABLISHED))
702 			sk->sk_shutdown |= RCV_SHUTDOWN;
703 	}
704 
705 	if (sctp_state(asoc, COOKIE_WAIT)) {
706 		/* Reset init timeouts since they may have been
707 		 * increased due to timer expirations.
708 		 */
709 		asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
710 						asoc->rto_initial;
711 		asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
712 						asoc->rto_initial;
713 	}
714 
715 	if (sctp_state(asoc, ESTABLISHED) ||
716 	    sctp_state(asoc, CLOSED) ||
717 	    sctp_state(asoc, SHUTDOWN_RECEIVED)) {
718 		/* Wake up any processes waiting in the asoc's wait queue in
719 		 * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
720 	 	 */
721 		if (waitqueue_active(&asoc->wait))
722 			wake_up_interruptible(&asoc->wait);
723 
724 		/* Wake up any processes waiting in the sk's sleep queue of
725 		 * a TCP-style or UDP-style peeled-off socket in
726 		 * sctp_wait_for_accept() or sctp_wait_for_packet().
727 		 * For a UDP-style socket, the waiters are woken up by the
728 		 * notifications.
729 		 */
730 		if (!sctp_style(sk, UDP))
731 			sk->sk_state_change(sk);
732 	}
733 }
734 
735 /* Helper function to delete an association. */
736 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
737 				struct sctp_association *asoc)
738 {
739 	struct sock *sk = asoc->base.sk;
740 
741 	/* If it is a non-temporary association belonging to a TCP-style
742 	 * listening socket that is not closed, do not free it so that accept()
743 	 * can pick it up later.
744 	 */
745 	if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
746 	    (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
747 		return;
748 
749 	sctp_unhash_established(asoc);
750 	sctp_association_free(asoc);
751 }
752 
753 /*
754  * ADDIP Section 4.1 ASCONF Chunk Procedures
755  * A4) Start a T-4 RTO timer, using the RTO value of the selected
756  * destination address (we use active path instead of primary path just
757  * because primary path may be inactive.
758  */
759 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
760 				struct sctp_association *asoc,
761 				struct sctp_chunk *chunk)
762 {
763 	struct sctp_transport *t;
764 
765 	t = asoc->peer.active_path;
766 	asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
767 	chunk->transport = t;
768 }
769 
770 /* Process an incoming Operation Error Chunk. */
771 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
772 				   struct sctp_association *asoc,
773 				   struct sctp_chunk *chunk)
774 {
775 	struct sctp_operr_chunk *operr_chunk;
776 	struct sctp_errhdr *err_hdr;
777 
778 	operr_chunk = (struct sctp_operr_chunk *)chunk->chunk_hdr;
779 	err_hdr = &operr_chunk->err_hdr;
780 
781 	switch (err_hdr->cause) {
782 	case SCTP_ERROR_UNKNOWN_CHUNK:
783 	{
784 		struct sctp_chunkhdr *unk_chunk_hdr;
785 
786 		unk_chunk_hdr = (struct sctp_chunkhdr *)err_hdr->variable;
787 		switch (unk_chunk_hdr->type) {
788 		/* ADDIP 4.1 A9) If the peer responds to an ASCONF with an
789 		 * ERROR chunk reporting that it did not recognized the ASCONF
790 		 * chunk type, the sender of the ASCONF MUST NOT send any
791 		 * further ASCONF chunks and MUST stop its T-4 timer.
792 		 */
793 		case SCTP_CID_ASCONF:
794 			asoc->peer.asconf_capable = 0;
795 			sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
796 					SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
797 			break;
798 		default:
799 			break;
800 		}
801 		break;
802 	}
803 	default:
804 		break;
805 	}
806 }
807 
808 /* Process variable FWDTSN chunk information. */
809 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
810 				    struct sctp_chunk *chunk)
811 {
812 	struct sctp_fwdtsn_skip *skip;
813 	/* Walk through all the skipped SSNs */
814 	sctp_walk_fwdtsn(skip, chunk) {
815 		sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
816 	}
817 
818 	return;
819 }
820 
821 /* Helper function to remove the association non-primary peer
822  * transports.
823  */
824 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
825 {
826 	struct sctp_transport *t;
827 	struct list_head *pos;
828 	struct list_head *temp;
829 
830 	list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
831 		t = list_entry(pos, struct sctp_transport, transports);
832 		if (!sctp_cmp_addr_exact(&t->ipaddr,
833 		                         &asoc->peer.primary_addr)) {
834 			sctp_assoc_del_peer(asoc, &t->ipaddr);
835 		}
836 	}
837 
838 	return;
839 }
840 
841 /* These three macros allow us to pull the debugging code out of the
842  * main flow of sctp_do_sm() to keep attention focused on the real
843  * functionality there.
844  */
845 #define DEBUG_PRE \
846 	SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
847 			  "ep %p, %s, %s, asoc %p[%s], %s\n", \
848 			  ep, sctp_evttype_tbl[event_type], \
849 			  (*debug_fn)(subtype), asoc, \
850 			  sctp_state_tbl[state], state_fn->name)
851 
852 #define DEBUG_POST \
853 	SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
854 			  "asoc %p, status: %s\n", \
855 			  asoc, sctp_status_tbl[status])
856 
857 #define DEBUG_POST_SFX \
858 	SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
859 			  error, asoc, \
860 			  sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
861 			  sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
862 
863 /*
864  * This is the master state machine processing function.
865  *
866  * If you want to understand all of lksctp, this is a
867  * good place to start.
868  */
869 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
870 	       sctp_state_t state,
871 	       struct sctp_endpoint *ep,
872 	       struct sctp_association *asoc,
873 	       void *event_arg,
874 	       gfp_t gfp)
875 {
876 	sctp_cmd_seq_t commands;
877 	const sctp_sm_table_entry_t *state_fn;
878 	sctp_disposition_t status;
879 	int error = 0;
880 	typedef const char *(printfn_t)(sctp_subtype_t);
881 
882 	static printfn_t *table[] = {
883 		NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
884 	};
885 	printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
886 
887 	/* Look up the state function, run it, and then process the
888 	 * side effects.  These three steps are the heart of lksctp.
889 	 */
890 	state_fn = sctp_sm_lookup_event(event_type, state, subtype);
891 
892 	sctp_init_cmd_seq(&commands);
893 
894 	DEBUG_PRE;
895 	status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
896 	DEBUG_POST;
897 
898 	error = sctp_side_effects(event_type, subtype, state,
899 				  ep, asoc, event_arg, status,
900 				  &commands, gfp);
901 	DEBUG_POST_SFX;
902 
903 	return error;
904 }
905 
906 #undef DEBUG_PRE
907 #undef DEBUG_POST
908 
909 /*****************************************************************
910  * This the master state function side effect processing function.
911  *****************************************************************/
912 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
913 			     sctp_state_t state,
914 			     struct sctp_endpoint *ep,
915 			     struct sctp_association *asoc,
916 			     void *event_arg,
917 			     sctp_disposition_t status,
918 			     sctp_cmd_seq_t *commands,
919 			     gfp_t gfp)
920 {
921 	int error;
922 
923 	/* FIXME - Most of the dispositions left today would be categorized
924 	 * as "exceptional" dispositions.  For those dispositions, it
925 	 * may not be proper to run through any of the commands at all.
926 	 * For example, the command interpreter might be run only with
927 	 * disposition SCTP_DISPOSITION_CONSUME.
928 	 */
929 	if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
930 					       ep, asoc,
931 					       event_arg, status,
932 					       commands, gfp)))
933 		goto bail;
934 
935 	switch (status) {
936 	case SCTP_DISPOSITION_DISCARD:
937 		SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
938 				  "event_type %d, event_id %d\n",
939 				  state, event_type, subtype.chunk);
940 		break;
941 
942 	case SCTP_DISPOSITION_NOMEM:
943 		/* We ran out of memory, so we need to discard this
944 		 * packet.
945 		 */
946 		/* BUG--we should now recover some memory, probably by
947 		 * reneging...
948 		 */
949 		error = -ENOMEM;
950 		break;
951 
952         case SCTP_DISPOSITION_DELETE_TCB:
953 		/* This should now be a command. */
954 		break;
955 
956 	case SCTP_DISPOSITION_CONSUME:
957 	case SCTP_DISPOSITION_ABORT:
958 		/*
959 		 * We should no longer have much work to do here as the
960 		 * real work has been done as explicit commands above.
961 		 */
962 		break;
963 
964 	case SCTP_DISPOSITION_VIOLATION:
965 		printk(KERN_ERR "sctp protocol violation state %d "
966 		       "chunkid %d\n", state, subtype.chunk);
967 		break;
968 
969 	case SCTP_DISPOSITION_NOT_IMPL:
970 		printk(KERN_WARNING "sctp unimplemented feature in state %d, "
971 		       "event_type %d, event_id %d\n",
972 		       state, event_type, subtype.chunk);
973 		break;
974 
975 	case SCTP_DISPOSITION_BUG:
976 		printk(KERN_ERR "sctp bug in state %d, "
977 		       "event_type %d, event_id %d\n",
978 		       state, event_type, subtype.chunk);
979 		BUG();
980 		break;
981 
982 	default:
983 		printk(KERN_ERR "sctp impossible disposition %d "
984 		       "in state %d, event_type %d, event_id %d\n",
985 		       status, state, event_type, subtype.chunk);
986 		BUG();
987 		break;
988 	};
989 
990 bail:
991 	return error;
992 }
993 
994 /********************************************************************
995  * 2nd Level Abstractions
996  ********************************************************************/
997 
998 /* This is the side-effect interpreter.  */
999 static int sctp_cmd_interpreter(sctp_event_t event_type,
1000 				sctp_subtype_t subtype,
1001 				sctp_state_t state,
1002 				struct sctp_endpoint *ep,
1003 				struct sctp_association *asoc,
1004 				void *event_arg,
1005 			 	sctp_disposition_t status,
1006 				sctp_cmd_seq_t *commands,
1007 				gfp_t gfp)
1008 {
1009 	int error = 0;
1010 	int force;
1011 	sctp_cmd_t *cmd;
1012 	struct sctp_chunk *new_obj;
1013 	struct sctp_chunk *chunk = NULL;
1014 	struct sctp_packet *packet;
1015 	struct list_head *pos;
1016 	struct timer_list *timer;
1017 	unsigned long timeout;
1018 	struct sctp_transport *t;
1019 	struct sctp_sackhdr sackh;
1020 	int local_cork = 0;
1021 
1022 	if (SCTP_EVENT_T_TIMEOUT != event_type)
1023 		chunk = (struct sctp_chunk *) event_arg;
1024 
1025 	/* Note:  This whole file is a huge candidate for rework.
1026 	 * For example, each command could either have its own handler, so
1027 	 * the loop would look like:
1028 	 *     while (cmds)
1029 	 *         cmd->handle(x, y, z)
1030 	 * --jgrimm
1031 	 */
1032 	while (NULL != (cmd = sctp_next_cmd(commands))) {
1033 		switch (cmd->verb) {
1034 		case SCTP_CMD_NOP:
1035 			/* Do nothing. */
1036 			break;
1037 
1038 		case SCTP_CMD_NEW_ASOC:
1039 			/* Register a new association.  */
1040 			if (local_cork) {
1041 				sctp_outq_uncork(&asoc->outqueue);
1042 				local_cork = 0;
1043 			}
1044 			asoc = cmd->obj.ptr;
1045 			/* Register with the endpoint.  */
1046 			sctp_endpoint_add_asoc(ep, asoc);
1047 			sctp_hash_established(asoc);
1048 			break;
1049 
1050 		case SCTP_CMD_UPDATE_ASSOC:
1051 		       sctp_assoc_update(asoc, cmd->obj.ptr);
1052 		       break;
1053 
1054 		case SCTP_CMD_PURGE_OUTQUEUE:
1055 		       sctp_outq_teardown(&asoc->outqueue);
1056 		       break;
1057 
1058 		case SCTP_CMD_DELETE_TCB:
1059 			if (local_cork) {
1060 				sctp_outq_uncork(&asoc->outqueue);
1061 				local_cork = 0;
1062 			}
1063 			/* Delete the current association.  */
1064 			sctp_cmd_delete_tcb(commands, asoc);
1065 			asoc = NULL;
1066 			break;
1067 
1068 		case SCTP_CMD_NEW_STATE:
1069 			/* Enter a new state.  */
1070 			sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1071 			break;
1072 
1073 		case SCTP_CMD_REPORT_TSN:
1074 			/* Record the arrival of a TSN.  */
1075 			sctp_tsnmap_mark(&asoc->peer.tsn_map, cmd->obj.u32);
1076 			break;
1077 
1078 		case SCTP_CMD_REPORT_FWDTSN:
1079 			/* Move the Cumulattive TSN Ack ahead. */
1080 			sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1081 
1082 			/* Abort any in progress partial delivery. */
1083 			sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1084 			break;
1085 
1086 		case SCTP_CMD_PROCESS_FWDTSN:
1087 			sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1088                         break;
1089 
1090 		case SCTP_CMD_GEN_SACK:
1091 			/* Generate a Selective ACK.
1092 			 * The argument tells us whether to just count
1093 			 * the packet and MAYBE generate a SACK, or
1094 			 * force a SACK out.
1095 			 */
1096 			force = cmd->obj.i32;
1097 			error = sctp_gen_sack(asoc, force, commands);
1098 			break;
1099 
1100 		case SCTP_CMD_PROCESS_SACK:
1101 			/* Process an inbound SACK.  */
1102 			error = sctp_cmd_process_sack(commands, asoc,
1103 						      cmd->obj.ptr);
1104 			break;
1105 
1106 		case SCTP_CMD_GEN_INIT_ACK:
1107 			/* Generate an INIT ACK chunk.  */
1108 			new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1109 						     0);
1110 			if (!new_obj)
1111 				goto nomem;
1112 
1113 			sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1114 					SCTP_CHUNK(new_obj));
1115 			break;
1116 
1117 		case SCTP_CMD_PEER_INIT:
1118 			/* Process a unified INIT from the peer.
1119 			 * Note: Only used during INIT-ACK processing.  If
1120 			 * there is an error just return to the outter
1121 			 * layer which will bail.
1122 			 */
1123 			error = sctp_cmd_process_init(commands, asoc, chunk,
1124 						      cmd->obj.ptr, gfp);
1125 			break;
1126 
1127 		case SCTP_CMD_GEN_COOKIE_ECHO:
1128 			/* Generate a COOKIE ECHO chunk.  */
1129 			new_obj = sctp_make_cookie_echo(asoc, chunk);
1130 			if (!new_obj) {
1131 				if (cmd->obj.ptr)
1132 					sctp_chunk_free(cmd->obj.ptr);
1133 				goto nomem;
1134 			}
1135 			sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1136 					SCTP_CHUNK(new_obj));
1137 
1138 			/* If there is an ERROR chunk to be sent along with
1139 			 * the COOKIE_ECHO, send it, too.
1140 			 */
1141 			if (cmd->obj.ptr)
1142 				sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1143 						SCTP_CHUNK(cmd->obj.ptr));
1144 
1145 			/* FIXME - Eventually come up with a cleaner way to
1146 			 * enabling COOKIE-ECHO + DATA bundling during
1147 			 * multihoming stale cookie scenarios, the following
1148 			 * command plays with asoc->peer.retran_path to
1149 			 * avoid the problem of sending the COOKIE-ECHO and
1150 			 * DATA in different paths, which could result
1151 			 * in the association being ABORTed if the DATA chunk
1152 			 * is processed first by the server.  Checking the
1153 			 * init error counter simply causes this command
1154 			 * to be executed only during failed attempts of
1155 			 * association establishment.
1156 			 */
1157 			if ((asoc->peer.retran_path !=
1158 			     asoc->peer.primary_path) &&
1159 			    (asoc->init_err_counter > 0)) {
1160 				sctp_add_cmd_sf(commands,
1161 				                SCTP_CMD_FORCE_PRIM_RETRAN,
1162 						SCTP_NULL());
1163 			}
1164 
1165 			break;
1166 
1167 		case SCTP_CMD_GEN_SHUTDOWN:
1168 			/* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1169 			 * Reset error counts.
1170 			 */
1171 			asoc->overall_error_count = 0;
1172 
1173 			/* Generate a SHUTDOWN chunk.  */
1174 			new_obj = sctp_make_shutdown(asoc, chunk);
1175 			if (!new_obj)
1176 				goto nomem;
1177 			sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1178 					SCTP_CHUNK(new_obj));
1179 			break;
1180 
1181 		case SCTP_CMD_CHUNK_ULP:
1182 			/* Send a chunk to the sockets layer.  */
1183 			SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1184 					  "chunk_up:", cmd->obj.ptr,
1185 					  "ulpq:", &asoc->ulpq);
1186 			sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1187 					    GFP_ATOMIC);
1188 			break;
1189 
1190 		case SCTP_CMD_EVENT_ULP:
1191 			/* Send a notification to the sockets layer.  */
1192 			SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1193 					  "event_up:",cmd->obj.ptr,
1194 					  "ulpq:",&asoc->ulpq);
1195 			sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1196 			break;
1197 
1198 		case SCTP_CMD_REPLY:
1199 			/* If an caller has not already corked, do cork. */
1200 			if (!asoc->outqueue.cork) {
1201 				sctp_outq_cork(&asoc->outqueue);
1202 				local_cork = 1;
1203 			}
1204 			/* Send a chunk to our peer.  */
1205 			error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1206 			break;
1207 
1208 		case SCTP_CMD_SEND_PKT:
1209 			/* Send a full packet to our peer.  */
1210 			packet = cmd->obj.ptr;
1211 			sctp_packet_transmit(packet);
1212 			sctp_ootb_pkt_free(packet);
1213 			break;
1214 
1215 		case SCTP_CMD_RETRAN:
1216 			/* Mark a transport for retransmission.  */
1217 			sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1218 					SCTP_RTXR_T3_RTX);
1219 			break;
1220 
1221 		case SCTP_CMD_TRANSMIT:
1222 			/* Kick start transmission. */
1223 			error = sctp_outq_uncork(&asoc->outqueue);
1224 			local_cork = 0;
1225 			break;
1226 
1227 		case SCTP_CMD_ECN_CE:
1228 			/* Do delayed CE processing.   */
1229 			sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1230 			break;
1231 
1232 		case SCTP_CMD_ECN_ECNE:
1233 			/* Do delayed ECNE processing. */
1234 			new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1235 							chunk);
1236 			if (new_obj)
1237 				sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1238 						SCTP_CHUNK(new_obj));
1239 			break;
1240 
1241 		case SCTP_CMD_ECN_CWR:
1242 			/* Do delayed CWR processing.  */
1243 			sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1244 			break;
1245 
1246 		case SCTP_CMD_SETUP_T2:
1247 			sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1248 			break;
1249 
1250 		case SCTP_CMD_TIMER_START:
1251 			timer = &asoc->timers[cmd->obj.to];
1252 			timeout = asoc->timeouts[cmd->obj.to];
1253 			BUG_ON(!timeout);
1254 
1255 			timer->expires = jiffies + timeout;
1256 			sctp_association_hold(asoc);
1257 			add_timer(timer);
1258 			break;
1259 
1260 		case SCTP_CMD_TIMER_RESTART:
1261 			timer = &asoc->timers[cmd->obj.to];
1262 			timeout = asoc->timeouts[cmd->obj.to];
1263 			if (!mod_timer(timer, jiffies + timeout))
1264 				sctp_association_hold(asoc);
1265 			break;
1266 
1267 		case SCTP_CMD_TIMER_STOP:
1268 			timer = &asoc->timers[cmd->obj.to];
1269 			if (timer_pending(timer) && del_timer(timer))
1270 				sctp_association_put(asoc);
1271 			break;
1272 
1273 		case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1274 			chunk = cmd->obj.ptr;
1275 			t = sctp_assoc_choose_init_transport(asoc);
1276 			asoc->init_last_sent_to = t;
1277 			chunk->transport = t;
1278 			t->init_sent_count++;
1279 			break;
1280 
1281 		case SCTP_CMD_INIT_RESTART:
1282 			/* Do the needed accounting and updates
1283 			 * associated with restarting an initialization
1284 			 * timer. Only multiply the timeout by two if
1285 			 * all transports have been tried at the current
1286 			 * timeout.
1287 			 */
1288 			t = asoc->init_last_sent_to;
1289 			asoc->init_err_counter++;
1290 
1291 			if (t->init_sent_count > (asoc->init_cycle + 1)) {
1292 				asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] *= 2;
1293 				if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] >
1294 				    asoc->max_init_timeo) {
1295 					asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
1296 						asoc->max_init_timeo;
1297 				}
1298 				asoc->init_cycle++;
1299 				SCTP_DEBUG_PRINTK(
1300 					"T1 INIT Timeout adjustment"
1301 					" init_err_counter: %d"
1302 					" cycle: %d"
1303 					" timeout: %d\n",
1304 					asoc->init_err_counter,
1305 					asoc->init_cycle,
1306 					asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT]);
1307 			}
1308 
1309 			sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1310 					SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1311 			break;
1312 
1313 		case SCTP_CMD_COOKIEECHO_RESTART:
1314 			/* Do the needed accounting and updates
1315 			 * associated with restarting an initialization
1316 			 * timer. Only multiply the timeout by two if
1317 			 * all transports have been tried at the current
1318 			 * timeout.
1319 			 */
1320 			asoc->init_err_counter++;
1321 
1322 			asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] *= 2;
1323 			if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] >
1324 			    asoc->max_init_timeo) {
1325 				asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
1326 					asoc->max_init_timeo;
1327 			}
1328 			SCTP_DEBUG_PRINTK(
1329 				"T1 COOKIE Timeout adjustment"
1330 				" init_err_counter: %d"
1331 				" timeout: %d\n",
1332 				asoc->init_err_counter,
1333 				asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE]);
1334 
1335 			/* If we've sent any data bundled with
1336 			 * COOKIE-ECHO we need to resend.
1337 			 */
1338 			list_for_each(pos, &asoc->peer.transport_addr_list) {
1339 				t = list_entry(pos, struct sctp_transport,
1340 					       transports);
1341 				sctp_retransmit_mark(&asoc->outqueue, t, 0);
1342 			}
1343 
1344 			sctp_add_cmd_sf(commands,
1345 					SCTP_CMD_TIMER_RESTART,
1346 					SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1347 			break;
1348 
1349 		case SCTP_CMD_INIT_FAILED:
1350 			sctp_cmd_init_failed(commands, asoc, cmd->obj.u32);
1351 			break;
1352 
1353 		case SCTP_CMD_ASSOC_FAILED:
1354 			sctp_cmd_assoc_failed(commands, asoc, event_type,
1355 					      subtype, chunk, cmd->obj.u32);
1356 			break;
1357 
1358 		case SCTP_CMD_INIT_COUNTER_INC:
1359 			asoc->init_err_counter++;
1360 			break;
1361 
1362 		case SCTP_CMD_INIT_COUNTER_RESET:
1363 			asoc->init_err_counter = 0;
1364 			asoc->init_cycle = 0;
1365 			break;
1366 
1367 		case SCTP_CMD_REPORT_DUP:
1368 			sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1369 					     cmd->obj.u32);
1370 			break;
1371 
1372 		case SCTP_CMD_REPORT_BAD_TAG:
1373 			SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1374 			break;
1375 
1376 		case SCTP_CMD_STRIKE:
1377 			/* Mark one strike against a transport.  */
1378 			sctp_do_8_2_transport_strike(asoc, cmd->obj.transport);
1379 			break;
1380 
1381 		case SCTP_CMD_TRANSPORT_RESET:
1382 			t = cmd->obj.transport;
1383 			sctp_cmd_transport_reset(commands, asoc, t);
1384 			break;
1385 
1386 		case SCTP_CMD_TRANSPORT_ON:
1387 			t = cmd->obj.transport;
1388 			sctp_cmd_transport_on(commands, asoc, t, chunk);
1389 			break;
1390 
1391 		case SCTP_CMD_HB_TIMERS_START:
1392 			sctp_cmd_hb_timers_start(commands, asoc);
1393 			break;
1394 
1395 		case SCTP_CMD_HB_TIMER_UPDATE:
1396 			t = cmd->obj.transport;
1397 			sctp_cmd_hb_timer_update(commands, asoc, t);
1398 			break;
1399 
1400 		case SCTP_CMD_HB_TIMERS_STOP:
1401 			sctp_cmd_hb_timers_stop(commands, asoc);
1402 			break;
1403 
1404 		case SCTP_CMD_REPORT_ERROR:
1405 			error = cmd->obj.error;
1406 			break;
1407 
1408 		case SCTP_CMD_PROCESS_CTSN:
1409 			/* Dummy up a SACK for processing. */
1410 			sackh.cum_tsn_ack = cmd->obj.u32;
1411 			sackh.a_rwnd = 0;
1412 			sackh.num_gap_ack_blocks = 0;
1413 			sackh.num_dup_tsns = 0;
1414 			sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1415 					SCTP_SACKH(&sackh));
1416 			break;
1417 
1418 		case SCTP_CMD_DISCARD_PACKET:
1419 			/* We need to discard the whole packet.  */
1420 			chunk->pdiscard = 1;
1421 			break;
1422 
1423 		case SCTP_CMD_RTO_PENDING:
1424 			t = cmd->obj.transport;
1425 			t->rto_pending = 1;
1426 			break;
1427 
1428 		case SCTP_CMD_PART_DELIVER:
1429 			sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1430 						   GFP_ATOMIC);
1431 			break;
1432 
1433 		case SCTP_CMD_RENEGE:
1434 			sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1435 					 GFP_ATOMIC);
1436 			break;
1437 
1438 		case SCTP_CMD_SETUP_T4:
1439 			sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1440 			break;
1441 
1442 		case SCTP_CMD_PROCESS_OPERR:
1443 			sctp_cmd_process_operr(commands, asoc, chunk);
1444 			break;
1445 		case SCTP_CMD_CLEAR_INIT_TAG:
1446 			asoc->peer.i.init_tag = 0;
1447 			break;
1448 		case SCTP_CMD_DEL_NON_PRIMARY:
1449 			sctp_cmd_del_non_primary(asoc);
1450 			break;
1451 		case SCTP_CMD_T3_RTX_TIMERS_STOP:
1452 			sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1453 			break;
1454 		case SCTP_CMD_FORCE_PRIM_RETRAN:
1455 			t = asoc->peer.retran_path;
1456 			asoc->peer.retran_path = asoc->peer.primary_path;
1457 			error = sctp_outq_uncork(&asoc->outqueue);
1458 			local_cork = 0;
1459 			asoc->peer.retran_path = t;
1460 			break;
1461 		default:
1462 			printk(KERN_WARNING "Impossible command: %u, %p\n",
1463 			       cmd->verb, cmd->obj.ptr);
1464 			break;
1465 		};
1466 		if (error)
1467 			break;
1468 	}
1469 
1470 out:
1471 	if (local_cork)
1472 		sctp_outq_uncork(&asoc->outqueue);
1473 	return error;
1474 nomem:
1475 	error = -ENOMEM;
1476 	goto out;
1477 }
1478 
1479