xref: /linux/net/sctp/sm_sideeffect.c (revision 60b2737de1b1ddfdb90f3ba622634eb49d6f3603)
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 				int 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 			     int 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 	int error = 0;
161 
162 	if (force)
163 		asoc->peer.sack_needed = 1;
164 
165 	ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
166 	max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
167 
168 	/* From 12.2 Parameters necessary per association (i.e. the TCB):
169 	 *
170 	 * Ack State : This flag indicates if the next received packet
171 	 * 	     : is to be responded to with a SACK. ...
172 	 *	     : When DATA chunks are out of order, SACK's
173 	 *           : are not delayed (see Section 6).
174 	 *
175 	 * [This is actually not mentioned in Section 6, but we
176 	 * implement it here anyway. --piggy]
177 	 */
178         if (max_tsn_seen != ctsn)
179 		asoc->peer.sack_needed = 1;
180 
181 	/* From 6.2  Acknowledgement on Reception of DATA Chunks:
182 	 *
183 	 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
184 	 * an acknowledgement SHOULD be generated for at least every
185 	 * second packet (not every second DATA chunk) received, and
186 	 * SHOULD be generated within 200 ms of the arrival of any
187 	 * unacknowledged DATA chunk. ...
188 	 */
189 	if (!asoc->peer.sack_needed) {
190 		/* We will need a SACK for the next packet.  */
191 		asoc->peer.sack_needed = 1;
192 		goto out;
193 	} else {
194 		if (asoc->a_rwnd > asoc->rwnd)
195 			asoc->a_rwnd = asoc->rwnd;
196 		sack = sctp_make_sack(asoc);
197 		if (!sack)
198 			goto nomem;
199 
200 		asoc->peer.sack_needed = 0;
201 
202 		error = sctp_outq_tail(&asoc->outqueue, sack);
203 
204 		/* Stop the SACK timer.  */
205 		sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
206 				SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
207 	}
208 out:
209 	return error;
210 nomem:
211 	error = -ENOMEM;
212 	return error;
213 }
214 
215 /* When the T3-RTX timer expires, it calls this function to create the
216  * relevant state machine event.
217  */
218 void sctp_generate_t3_rtx_event(unsigned long peer)
219 {
220 	int error;
221 	struct sctp_transport *transport = (struct sctp_transport *) peer;
222 	struct sctp_association *asoc = transport->asoc;
223 
224 	/* Check whether a task is in the sock.  */
225 
226 	sctp_bh_lock_sock(asoc->base.sk);
227 	if (sock_owned_by_user(asoc->base.sk)) {
228 		SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __FUNCTION__);
229 
230 		/* Try again later.  */
231 		if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
232 			sctp_transport_hold(transport);
233 		goto out_unlock;
234 	}
235 
236 	/* Is this transport really dead and just waiting around for
237 	 * the timer to let go of the reference?
238 	 */
239 	if (transport->dead)
240 		goto out_unlock;
241 
242 	/* Run through the state machine.  */
243 	error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
244 			   SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
245 			   asoc->state,
246 			   asoc->ep, asoc,
247 			   transport, GFP_ATOMIC);
248 
249 	if (error)
250 		asoc->base.sk->sk_err = -error;
251 
252 out_unlock:
253 	sctp_bh_unlock_sock(asoc->base.sk);
254 	sctp_transport_put(transport);
255 }
256 
257 /* This is a sa interface for producing timeout events.  It works
258  * for timeouts which use the association as their parameter.
259  */
260 static void sctp_generate_timeout_event(struct sctp_association *asoc,
261 					sctp_event_timeout_t timeout_type)
262 {
263 	int error = 0;
264 
265 	sctp_bh_lock_sock(asoc->base.sk);
266 	if (sock_owned_by_user(asoc->base.sk)) {
267 		SCTP_DEBUG_PRINTK("%s:Sock is busy: timer %d\n",
268 				  __FUNCTION__,
269 				  timeout_type);
270 
271 		/* Try again later.  */
272 		if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
273 			sctp_association_hold(asoc);
274 		goto out_unlock;
275 	}
276 
277 	/* Is this association really dead and just waiting around for
278 	 * the timer to let go of the reference?
279 	 */
280 	if (asoc->base.dead)
281 		goto out_unlock;
282 
283 	/* Run through the state machine.  */
284 	error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
285 			   SCTP_ST_TIMEOUT(timeout_type),
286 			   asoc->state, asoc->ep, asoc,
287 			   (void *)timeout_type, GFP_ATOMIC);
288 
289 	if (error)
290 		asoc->base.sk->sk_err = -error;
291 
292 out_unlock:
293 	sctp_bh_unlock_sock(asoc->base.sk);
294 	sctp_association_put(asoc);
295 }
296 
297 static void sctp_generate_t1_cookie_event(unsigned long data)
298 {
299 	struct sctp_association *asoc = (struct sctp_association *) data;
300 	sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
301 }
302 
303 static void sctp_generate_t1_init_event(unsigned long data)
304 {
305 	struct sctp_association *asoc = (struct sctp_association *) data;
306 	sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
307 }
308 
309 static void sctp_generate_t2_shutdown_event(unsigned long data)
310 {
311 	struct sctp_association *asoc = (struct sctp_association *) data;
312 	sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
313 }
314 
315 static void sctp_generate_t4_rto_event(unsigned long data)
316 {
317 	struct sctp_association *asoc = (struct sctp_association *) data;
318 	sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
319 }
320 
321 static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
322 {
323         struct sctp_association *asoc = (struct sctp_association *)data;
324         sctp_generate_timeout_event(asoc,
325 				    SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
326 
327 } /* sctp_generate_t5_shutdown_guard_event() */
328 
329 static void sctp_generate_autoclose_event(unsigned long data)
330 {
331 	struct sctp_association *asoc = (struct sctp_association *) data;
332 	sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
333 }
334 
335 /* Generate a heart beat event.  If the sock is busy, reschedule.   Make
336  * sure that the transport is still valid.
337  */
338 void sctp_generate_heartbeat_event(unsigned long data)
339 {
340 	int error = 0;
341 	struct sctp_transport *transport = (struct sctp_transport *) data;
342 	struct sctp_association *asoc = transport->asoc;
343 
344 	sctp_bh_lock_sock(asoc->base.sk);
345 	if (sock_owned_by_user(asoc->base.sk)) {
346 		SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __FUNCTION__);
347 
348 		/* Try again later.  */
349 		if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
350 			sctp_transport_hold(transport);
351 		goto out_unlock;
352 	}
353 
354 	/* Is this structure just waiting around for us to actually
355 	 * get destroyed?
356 	 */
357 	if (transport->dead)
358 		goto out_unlock;
359 
360 	error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
361 			   SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
362 			   asoc->state, asoc->ep, asoc,
363 			   transport, GFP_ATOMIC);
364 
365          if (error)
366 		 asoc->base.sk->sk_err = -error;
367 
368 out_unlock:
369 	sctp_bh_unlock_sock(asoc->base.sk);
370 	sctp_transport_put(transport);
371 }
372 
373 /* Inject a SACK Timeout event into the state machine.  */
374 static void sctp_generate_sack_event(unsigned long data)
375 {
376 	struct sctp_association *asoc = (struct sctp_association *) data;
377 	sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
378 }
379 
380 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
381 	NULL,
382 	sctp_generate_t1_cookie_event,
383 	sctp_generate_t1_init_event,
384 	sctp_generate_t2_shutdown_event,
385 	NULL,
386 	sctp_generate_t4_rto_event,
387 	sctp_generate_t5_shutdown_guard_event,
388 	sctp_generate_heartbeat_event,
389 	sctp_generate_sack_event,
390 	sctp_generate_autoclose_event,
391 };
392 
393 
394 /* RFC 2960 8.2 Path Failure Detection
395  *
396  * When its peer endpoint is multi-homed, an endpoint should keep a
397  * error counter for each of the destination transport addresses of the
398  * peer endpoint.
399  *
400  * Each time the T3-rtx timer expires on any address, or when a
401  * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
402  * the error counter of that destination address will be incremented.
403  * When the value in the error counter exceeds the protocol parameter
404  * 'Path.Max.Retrans' of that destination address, the endpoint should
405  * mark the destination transport address as inactive, and a
406  * notification SHOULD be sent to the upper layer.
407  *
408  */
409 static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
410 					 struct sctp_transport *transport)
411 {
412 	/* The check for association's overall error counter exceeding the
413 	 * threshold is done in the state function.
414 	 */
415 	asoc->overall_error_count++;
416 
417 	if (transport->state != SCTP_INACTIVE &&
418 	    (transport->error_count++ >= transport->max_retrans)) {
419 		SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
420 					 " transport IP: port:%d failed.\n",
421 					 asoc,
422 					 (&transport->ipaddr),
423 					 transport->ipaddr.v4.sin_port);
424 		sctp_assoc_control_transport(asoc, transport,
425 					     SCTP_TRANSPORT_DOWN,
426 					     SCTP_FAILED_THRESHOLD);
427 	}
428 
429 	/* E2) For the destination address for which the timer
430 	 * expires, set RTO <- RTO * 2 ("back off the timer").  The
431 	 * maximum value discussed in rule C7 above (RTO.max) may be
432 	 * used to provide an upper bound to this doubling operation.
433 	 */
434 	transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
435 }
436 
437 /* Worker routine to handle INIT command failure.  */
438 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
439 				 struct sctp_association *asoc,
440 				 unsigned error)
441 {
442 	struct sctp_ulpevent *event;
443 
444 	event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
445 						(__u16)error, 0, 0,
446 						GFP_ATOMIC);
447 
448 	if (event)
449 		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
450 				SCTP_ULPEVENT(event));
451 
452 	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
453 			SCTP_STATE(SCTP_STATE_CLOSED));
454 
455 	/* SEND_FAILED sent later when cleaning up the association. */
456 	asoc->outqueue.error = error;
457 	sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
458 }
459 
460 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
461 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
462 				  struct sctp_association *asoc,
463 				  sctp_event_t event_type,
464 				  sctp_subtype_t subtype,
465 				  struct sctp_chunk *chunk,
466 				  unsigned error)
467 {
468 	struct sctp_ulpevent *event;
469 
470 	/* Cancel any partial delivery in progress. */
471 	sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
472 
473 	event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
474 						(__u16)error, 0, 0,
475 						GFP_ATOMIC);
476 	if (event)
477 		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
478 				SCTP_ULPEVENT(event));
479 
480 	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
481 			SCTP_STATE(SCTP_STATE_CLOSED));
482 
483 	/* Set sk_err to ECONNRESET on a 1-1 style socket. */
484 	if (!sctp_style(asoc->base.sk, UDP))
485 		asoc->base.sk->sk_err = ECONNRESET;
486 
487 	/* SEND_FAILED sent later when cleaning up the association. */
488 	asoc->outqueue.error = error;
489 	sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
490 }
491 
492 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
493  * inside the cookie.  In reality, this is only used for INIT-ACK processing
494  * since all other cases use "temporary" associations and can do all
495  * their work in statefuns directly.
496  */
497 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
498 				 struct sctp_association *asoc,
499 				 struct sctp_chunk *chunk,
500 				 sctp_init_chunk_t *peer_init, int gfp)
501 {
502 	int error;
503 
504 	/* We only process the init as a sideeffect in a single
505 	 * case.   This is when we process the INIT-ACK.   If we
506 	 * fail during INIT processing (due to malloc problems),
507 	 * just return the error and stop processing the stack.
508 	 */
509 	if (!sctp_process_init(asoc, chunk->chunk_hdr->type,
510 			       sctp_source(chunk), peer_init, gfp))
511 		error = -ENOMEM;
512 	else
513 		error = 0;
514 
515 	return error;
516 }
517 
518 /* Helper function to break out starting up of heartbeat timers.  */
519 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
520 				     struct sctp_association *asoc)
521 {
522 	struct sctp_transport *t;
523 	struct list_head *pos;
524 
525 	/* Start a heartbeat timer for each transport on the association.
526 	 * hold a reference on the transport to make sure none of
527 	 * the needed data structures go away.
528 	 */
529 	list_for_each(pos, &asoc->peer.transport_addr_list) {
530 		t = list_entry(pos, struct sctp_transport, transports);
531 
532 		if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
533 			sctp_transport_hold(t);
534 	}
535 }
536 
537 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
538 				    struct sctp_association *asoc)
539 {
540 	struct sctp_transport *t;
541 	struct list_head *pos;
542 
543 	/* Stop all heartbeat timers. */
544 
545 	list_for_each(pos, &asoc->peer.transport_addr_list) {
546 		t = list_entry(pos, struct sctp_transport, transports);
547 		if (del_timer(&t->hb_timer))
548 			sctp_transport_put(t);
549 	}
550 }
551 
552 /* Helper function to stop any pending T3-RTX timers */
553 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
554 				        struct sctp_association *asoc)
555 {
556 	struct sctp_transport *t;
557 	struct list_head *pos;
558 
559 	list_for_each(pos, &asoc->peer.transport_addr_list) {
560 		t = list_entry(pos, struct sctp_transport, transports);
561 		if (timer_pending(&t->T3_rtx_timer) &&
562 		    del_timer(&t->T3_rtx_timer)) {
563 			sctp_transport_put(t);
564 		}
565 	}
566 }
567 
568 
569 /* Helper function to update the heartbeat timer. */
570 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
571 				     struct sctp_association *asoc,
572 				     struct sctp_transport *t)
573 {
574 	/* Update the heartbeat timer.  */
575 	if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
576 		sctp_transport_hold(t);
577 }
578 
579 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
580 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
581 				  struct sctp_association *asoc,
582 				  struct sctp_transport *t,
583 				  struct sctp_chunk *chunk)
584 {
585 	sctp_sender_hb_info_t *hbinfo;
586 
587 	/* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
588 	 * HEARTBEAT should clear the error counter of the destination
589 	 * transport address to which the HEARTBEAT was sent.
590 	 * The association's overall error count is also cleared.
591 	 */
592 	t->error_count = 0;
593 	t->asoc->overall_error_count = 0;
594 
595 	/* Mark the destination transport address as active if it is not so
596 	 * marked.
597 	 */
598 	if (t->state == SCTP_INACTIVE)
599 		sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
600 					     SCTP_HEARTBEAT_SUCCESS);
601 
602 	/* The receiver of the HEARTBEAT ACK should also perform an
603 	 * RTT measurement for that destination transport address
604 	 * using the time value carried in the HEARTBEAT ACK chunk.
605 	 */
606 	hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
607 	sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
608 }
609 
610 /* Helper function to do a transport reset at the expiry of the hearbeat
611  * timer.
612  */
613 static void sctp_cmd_transport_reset(sctp_cmd_seq_t *cmds,
614 				     struct sctp_association *asoc,
615 				     struct sctp_transport *t)
616 {
617 	sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
618 
619 	/* Mark one strike against a transport.  */
620 	sctp_do_8_2_transport_strike(asoc, t);
621 }
622 
623 /* Helper function to process the process SACK command.  */
624 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
625 				 struct sctp_association *asoc,
626 				 struct sctp_sackhdr *sackh)
627 {
628 	int err;
629 
630 	if (sctp_outq_sack(&asoc->outqueue, sackh)) {
631 		/* There are no more TSNs awaiting SACK.  */
632 		err = sctp_do_sm(SCTP_EVENT_T_OTHER,
633 				 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
634 				 asoc->state, asoc->ep, asoc, NULL,
635 				 GFP_ATOMIC);
636 	} else {
637 		/* Windows may have opened, so we need
638 		 * to check if we have DATA to transmit
639 		 */
640 		err = sctp_outq_flush(&asoc->outqueue, 0);
641 	}
642 
643 	return err;
644 }
645 
646 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
647  * the transport for a shutdown chunk.
648  */
649 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
650 			      struct sctp_association *asoc,
651 			      struct sctp_chunk *chunk)
652 {
653 	struct sctp_transport *t;
654 
655 	t = sctp_assoc_choose_shutdown_transport(asoc);
656 	asoc->shutdown_last_sent_to = t;
657 	asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
658 	chunk->transport = t;
659 }
660 
661 /* Helper function to change the state of an association. */
662 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
663 			       struct sctp_association *asoc,
664 			       sctp_state_t state)
665 {
666 	struct sock *sk = asoc->base.sk;
667 
668 	asoc->state = state;
669 
670 	SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
671 			  asoc, sctp_state_tbl[state]);
672 
673 	if (sctp_style(sk, TCP)) {
674 		/* Change the sk->sk_state of a TCP-style socket that has
675 		 * sucessfully completed a connect() call.
676 		 */
677 		if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
678 			sk->sk_state = SCTP_SS_ESTABLISHED;
679 
680 		/* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
681 		if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
682 		    sctp_sstate(sk, ESTABLISHED))
683 			sk->sk_shutdown |= RCV_SHUTDOWN;
684 	}
685 
686 	if (sctp_state(asoc, COOKIE_WAIT)) {
687 		/* Reset init timeouts since they may have been
688 		 * increased due to timer expirations.
689 		 */
690 		asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
691 			asoc->ep->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT];
692 		asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
693 			asoc->ep->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE];
694 	}
695 
696 	if (sctp_state(asoc, ESTABLISHED) ||
697 	    sctp_state(asoc, CLOSED) ||
698 	    sctp_state(asoc, SHUTDOWN_RECEIVED)) {
699 		/* Wake up any processes waiting in the asoc's wait queue in
700 		 * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
701 	 	 */
702 		if (waitqueue_active(&asoc->wait))
703 			wake_up_interruptible(&asoc->wait);
704 
705 		/* Wake up any processes waiting in the sk's sleep queue of
706 		 * a TCP-style or UDP-style peeled-off socket in
707 		 * sctp_wait_for_accept() or sctp_wait_for_packet().
708 		 * For a UDP-style socket, the waiters are woken up by the
709 		 * notifications.
710 		 */
711 		if (!sctp_style(sk, UDP))
712 			sk->sk_state_change(sk);
713 	}
714 }
715 
716 /* Helper function to delete an association. */
717 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
718 				struct sctp_association *asoc)
719 {
720 	struct sock *sk = asoc->base.sk;
721 
722 	/* If it is a non-temporary association belonging to a TCP-style
723 	 * listening socket that is not closed, do not free it so that accept()
724 	 * can pick it up later.
725 	 */
726 	if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
727 	    (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
728 		return;
729 
730 	sctp_unhash_established(asoc);
731 	sctp_association_free(asoc);
732 }
733 
734 /*
735  * ADDIP Section 4.1 ASCONF Chunk Procedures
736  * A4) Start a T-4 RTO timer, using the RTO value of the selected
737  * destination address (we use active path instead of primary path just
738  * because primary path may be inactive.
739  */
740 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
741 				struct sctp_association *asoc,
742 				struct sctp_chunk *chunk)
743 {
744 	struct sctp_transport *t;
745 
746 	t = asoc->peer.active_path;
747 	asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
748 	chunk->transport = t;
749 }
750 
751 /* Process an incoming Operation Error Chunk. */
752 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
753 				   struct sctp_association *asoc,
754 				   struct sctp_chunk *chunk)
755 {
756 	struct sctp_operr_chunk *operr_chunk;
757 	struct sctp_errhdr *err_hdr;
758 
759 	operr_chunk = (struct sctp_operr_chunk *)chunk->chunk_hdr;
760 	err_hdr = &operr_chunk->err_hdr;
761 
762 	switch (err_hdr->cause) {
763 	case SCTP_ERROR_UNKNOWN_CHUNK:
764 	{
765 		struct sctp_chunkhdr *unk_chunk_hdr;
766 
767 		unk_chunk_hdr = (struct sctp_chunkhdr *)err_hdr->variable;
768 		switch (unk_chunk_hdr->type) {
769 		/* ADDIP 4.1 A9) If the peer responds to an ASCONF with an
770 		 * ERROR chunk reporting that it did not recognized the ASCONF
771 		 * chunk type, the sender of the ASCONF MUST NOT send any
772 		 * further ASCONF chunks and MUST stop its T-4 timer.
773 		 */
774 		case SCTP_CID_ASCONF:
775 			asoc->peer.asconf_capable = 0;
776 			sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
777 					SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
778 			break;
779 		default:
780 			break;
781 		}
782 		break;
783 	}
784 	default:
785 		break;
786 	}
787 }
788 
789 /* Process variable FWDTSN chunk information. */
790 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
791 				    struct sctp_chunk *chunk)
792 {
793 	struct sctp_fwdtsn_skip *skip;
794 	/* Walk through all the skipped SSNs */
795 	sctp_walk_fwdtsn(skip, chunk) {
796 		sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
797 	}
798 
799 	return;
800 }
801 
802 /* Helper function to remove the association non-primary peer
803  * transports.
804  */
805 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
806 {
807 	struct sctp_transport *t;
808 	struct list_head *pos;
809 	struct list_head *temp;
810 
811 	list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
812 		t = list_entry(pos, struct sctp_transport, transports);
813 		if (!sctp_cmp_addr_exact(&t->ipaddr,
814 		                         &asoc->peer.primary_addr)) {
815 			sctp_assoc_del_peer(asoc, &t->ipaddr);
816 		}
817 	}
818 
819 	return;
820 }
821 
822 /* These three macros allow us to pull the debugging code out of the
823  * main flow of sctp_do_sm() to keep attention focused on the real
824  * functionality there.
825  */
826 #define DEBUG_PRE \
827 	SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
828 			  "ep %p, %s, %s, asoc %p[%s], %s\n", \
829 			  ep, sctp_evttype_tbl[event_type], \
830 			  (*debug_fn)(subtype), asoc, \
831 			  sctp_state_tbl[state], state_fn->name)
832 
833 #define DEBUG_POST \
834 	SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
835 			  "asoc %p, status: %s\n", \
836 			  asoc, sctp_status_tbl[status])
837 
838 #define DEBUG_POST_SFX \
839 	SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
840 			  error, asoc, \
841 			  sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
842 			  sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
843 
844 /*
845  * This is the master state machine processing function.
846  *
847  * If you want to understand all of lksctp, this is a
848  * good place to start.
849  */
850 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
851 	       sctp_state_t state,
852 	       struct sctp_endpoint *ep,
853 	       struct sctp_association *asoc,
854 	       void *event_arg,
855 	       int gfp)
856 {
857 	sctp_cmd_seq_t commands;
858 	const sctp_sm_table_entry_t *state_fn;
859 	sctp_disposition_t status;
860 	int error = 0;
861 	typedef const char *(printfn_t)(sctp_subtype_t);
862 
863 	static printfn_t *table[] = {
864 		NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
865 	};
866 	printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
867 
868 	/* Look up the state function, run it, and then process the
869 	 * side effects.  These three steps are the heart of lksctp.
870 	 */
871 	state_fn = sctp_sm_lookup_event(event_type, state, subtype);
872 
873 	sctp_init_cmd_seq(&commands);
874 
875 	DEBUG_PRE;
876 	status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
877 	DEBUG_POST;
878 
879 	error = sctp_side_effects(event_type, subtype, state,
880 				  ep, asoc, event_arg, status,
881 				  &commands, gfp);
882 	DEBUG_POST_SFX;
883 
884 	return error;
885 }
886 
887 #undef DEBUG_PRE
888 #undef DEBUG_POST
889 
890 /*****************************************************************
891  * This the master state function side effect processing function.
892  *****************************************************************/
893 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
894 			     sctp_state_t state,
895 			     struct sctp_endpoint *ep,
896 			     struct sctp_association *asoc,
897 			     void *event_arg,
898 			     sctp_disposition_t status,
899 			     sctp_cmd_seq_t *commands,
900 			     int gfp)
901 {
902 	int error;
903 
904 	/* FIXME - Most of the dispositions left today would be categorized
905 	 * as "exceptional" dispositions.  For those dispositions, it
906 	 * may not be proper to run through any of the commands at all.
907 	 * For example, the command interpreter might be run only with
908 	 * disposition SCTP_DISPOSITION_CONSUME.
909 	 */
910 	if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
911 					       ep, asoc,
912 					       event_arg, status,
913 					       commands, gfp)))
914 		goto bail;
915 
916 	switch (status) {
917 	case SCTP_DISPOSITION_DISCARD:
918 		SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
919 				  "event_type %d, event_id %d\n",
920 				  state, event_type, subtype.chunk);
921 		break;
922 
923 	case SCTP_DISPOSITION_NOMEM:
924 		/* We ran out of memory, so we need to discard this
925 		 * packet.
926 		 */
927 		/* BUG--we should now recover some memory, probably by
928 		 * reneging...
929 		 */
930 		error = -ENOMEM;
931 		break;
932 
933         case SCTP_DISPOSITION_DELETE_TCB:
934 		/* This should now be a command. */
935 		break;
936 
937 	case SCTP_DISPOSITION_CONSUME:
938 	case SCTP_DISPOSITION_ABORT:
939 		/*
940 		 * We should no longer have much work to do here as the
941 		 * real work has been done as explicit commands above.
942 		 */
943 		break;
944 
945 	case SCTP_DISPOSITION_VIOLATION:
946 		printk(KERN_ERR "sctp protocol violation state %d "
947 		       "chunkid %d\n", state, subtype.chunk);
948 		break;
949 
950 	case SCTP_DISPOSITION_NOT_IMPL:
951 		printk(KERN_WARNING "sctp unimplemented feature in state %d, "
952 		       "event_type %d, event_id %d\n",
953 		       state, event_type, subtype.chunk);
954 		break;
955 
956 	case SCTP_DISPOSITION_BUG:
957 		printk(KERN_ERR "sctp bug in state %d, "
958 		       "event_type %d, event_id %d\n",
959 		       state, event_type, subtype.chunk);
960 		BUG();
961 		break;
962 
963 	default:
964 		printk(KERN_ERR "sctp impossible disposition %d "
965 		       "in state %d, event_type %d, event_id %d\n",
966 		       status, state, event_type, subtype.chunk);
967 		BUG();
968 		break;
969 	};
970 
971 bail:
972 	return error;
973 }
974 
975 /********************************************************************
976  * 2nd Level Abstractions
977  ********************************************************************/
978 
979 /* This is the side-effect interpreter.  */
980 static int sctp_cmd_interpreter(sctp_event_t event_type,
981 				sctp_subtype_t subtype,
982 				sctp_state_t state,
983 				struct sctp_endpoint *ep,
984 				struct sctp_association *asoc,
985 				void *event_arg,
986 			 	sctp_disposition_t status,
987 				sctp_cmd_seq_t *commands,
988 				int gfp)
989 {
990 	int error = 0;
991 	int force;
992 	sctp_cmd_t *cmd;
993 	struct sctp_chunk *new_obj;
994 	struct sctp_chunk *chunk = NULL;
995 	struct sctp_packet *packet;
996 	struct list_head *pos;
997 	struct timer_list *timer;
998 	unsigned long timeout;
999 	struct sctp_transport *t;
1000 	struct sctp_sackhdr sackh;
1001 	int local_cork = 0;
1002 
1003 	if (SCTP_EVENT_T_TIMEOUT != event_type)
1004 		chunk = (struct sctp_chunk *) event_arg;
1005 
1006 	/* Note:  This whole file is a huge candidate for rework.
1007 	 * For example, each command could either have its own handler, so
1008 	 * the loop would look like:
1009 	 *     while (cmds)
1010 	 *         cmd->handle(x, y, z)
1011 	 * --jgrimm
1012 	 */
1013 	while (NULL != (cmd = sctp_next_cmd(commands))) {
1014 		switch (cmd->verb) {
1015 		case SCTP_CMD_NOP:
1016 			/* Do nothing. */
1017 			break;
1018 
1019 		case SCTP_CMD_NEW_ASOC:
1020 			/* Register a new association.  */
1021 			if (local_cork) {
1022 				sctp_outq_uncork(&asoc->outqueue);
1023 				local_cork = 0;
1024 			}
1025 			asoc = cmd->obj.ptr;
1026 			/* Register with the endpoint.  */
1027 			sctp_endpoint_add_asoc(ep, asoc);
1028 			sctp_hash_established(asoc);
1029 			break;
1030 
1031 		case SCTP_CMD_UPDATE_ASSOC:
1032 		       sctp_assoc_update(asoc, cmd->obj.ptr);
1033 		       break;
1034 
1035 		case SCTP_CMD_PURGE_OUTQUEUE:
1036 		       sctp_outq_teardown(&asoc->outqueue);
1037 		       break;
1038 
1039 		case SCTP_CMD_DELETE_TCB:
1040 			if (local_cork) {
1041 				sctp_outq_uncork(&asoc->outqueue);
1042 				local_cork = 0;
1043 			}
1044 			/* Delete the current association.  */
1045 			sctp_cmd_delete_tcb(commands, asoc);
1046 			asoc = NULL;
1047 			break;
1048 
1049 		case SCTP_CMD_NEW_STATE:
1050 			/* Enter a new state.  */
1051 			sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1052 			break;
1053 
1054 		case SCTP_CMD_REPORT_TSN:
1055 			/* Record the arrival of a TSN.  */
1056 			sctp_tsnmap_mark(&asoc->peer.tsn_map, cmd->obj.u32);
1057 			break;
1058 
1059 		case SCTP_CMD_REPORT_FWDTSN:
1060 			/* Move the Cumulattive TSN Ack ahead. */
1061 			sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1062 
1063 			/* Abort any in progress partial delivery. */
1064 			sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1065 			break;
1066 
1067 		case SCTP_CMD_PROCESS_FWDTSN:
1068 			sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1069                         break;
1070 
1071 		case SCTP_CMD_GEN_SACK:
1072 			/* Generate a Selective ACK.
1073 			 * The argument tells us whether to just count
1074 			 * the packet and MAYBE generate a SACK, or
1075 			 * force a SACK out.
1076 			 */
1077 			force = cmd->obj.i32;
1078 			error = sctp_gen_sack(asoc, force, commands);
1079 			break;
1080 
1081 		case SCTP_CMD_PROCESS_SACK:
1082 			/* Process an inbound SACK.  */
1083 			error = sctp_cmd_process_sack(commands, asoc,
1084 						      cmd->obj.ptr);
1085 			break;
1086 
1087 		case SCTP_CMD_GEN_INIT_ACK:
1088 			/* Generate an INIT ACK chunk.  */
1089 			new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1090 						     0);
1091 			if (!new_obj)
1092 				goto nomem;
1093 
1094 			sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1095 					SCTP_CHUNK(new_obj));
1096 			break;
1097 
1098 		case SCTP_CMD_PEER_INIT:
1099 			/* Process a unified INIT from the peer.
1100 			 * Note: Only used during INIT-ACK processing.  If
1101 			 * there is an error just return to the outter
1102 			 * layer which will bail.
1103 			 */
1104 			error = sctp_cmd_process_init(commands, asoc, chunk,
1105 						      cmd->obj.ptr, gfp);
1106 			break;
1107 
1108 		case SCTP_CMD_GEN_COOKIE_ECHO:
1109 			/* Generate a COOKIE ECHO chunk.  */
1110 			new_obj = sctp_make_cookie_echo(asoc, chunk);
1111 			if (!new_obj) {
1112 				if (cmd->obj.ptr)
1113 					sctp_chunk_free(cmd->obj.ptr);
1114 				goto nomem;
1115 			}
1116 			sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1117 					SCTP_CHUNK(new_obj));
1118 
1119 			/* If there is an ERROR chunk to be sent along with
1120 			 * the COOKIE_ECHO, send it, too.
1121 			 */
1122 			if (cmd->obj.ptr)
1123 				sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1124 						SCTP_CHUNK(cmd->obj.ptr));
1125 
1126 			/* FIXME - Eventually come up with a cleaner way to
1127 			 * enabling COOKIE-ECHO + DATA bundling during
1128 			 * multihoming stale cookie scenarios, the following
1129 			 * command plays with asoc->peer.retran_path to
1130 			 * avoid the problem of sending the COOKIE-ECHO and
1131 			 * DATA in different paths, which could result
1132 			 * in the association being ABORTed if the DATA chunk
1133 			 * is processed first by the server.  Checking the
1134 			 * init error counter simply causes this command
1135 			 * to be executed only during failed attempts of
1136 			 * association establishment.
1137 			 */
1138 			if ((asoc->peer.retran_path !=
1139 			     asoc->peer.primary_path) &&
1140 			    (asoc->init_err_counter > 0)) {
1141 				sctp_add_cmd_sf(commands,
1142 				                SCTP_CMD_FORCE_PRIM_RETRAN,
1143 						SCTP_NULL());
1144 			}
1145 
1146 			break;
1147 
1148 		case SCTP_CMD_GEN_SHUTDOWN:
1149 			/* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1150 			 * Reset error counts.
1151 			 */
1152 			asoc->overall_error_count = 0;
1153 
1154 			/* Generate a SHUTDOWN chunk.  */
1155 			new_obj = sctp_make_shutdown(asoc, chunk);
1156 			if (!new_obj)
1157 				goto nomem;
1158 			sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1159 					SCTP_CHUNK(new_obj));
1160 			break;
1161 
1162 		case SCTP_CMD_CHUNK_ULP:
1163 			/* Send a chunk to the sockets layer.  */
1164 			SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1165 					  "chunk_up:", cmd->obj.ptr,
1166 					  "ulpq:", &asoc->ulpq);
1167 			sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1168 					    GFP_ATOMIC);
1169 			break;
1170 
1171 		case SCTP_CMD_EVENT_ULP:
1172 			/* Send a notification to the sockets layer.  */
1173 			SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1174 					  "event_up:",cmd->obj.ptr,
1175 					  "ulpq:",&asoc->ulpq);
1176 			sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1177 			break;
1178 
1179 		case SCTP_CMD_REPLY:
1180 			/* If an caller has not already corked, do cork. */
1181 			if (!asoc->outqueue.cork) {
1182 				sctp_outq_cork(&asoc->outqueue);
1183 				local_cork = 1;
1184 			}
1185 			/* Send a chunk to our peer.  */
1186 			error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1187 			break;
1188 
1189 		case SCTP_CMD_SEND_PKT:
1190 			/* Send a full packet to our peer.  */
1191 			packet = cmd->obj.ptr;
1192 			sctp_packet_transmit(packet);
1193 			sctp_ootb_pkt_free(packet);
1194 			break;
1195 
1196 		case SCTP_CMD_RETRAN:
1197 			/* Mark a transport for retransmission.  */
1198 			sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1199 					SCTP_RTXR_T3_RTX);
1200 			break;
1201 
1202 		case SCTP_CMD_TRANSMIT:
1203 			/* Kick start transmission. */
1204 			error = sctp_outq_uncork(&asoc->outqueue);
1205 			local_cork = 0;
1206 			break;
1207 
1208 		case SCTP_CMD_ECN_CE:
1209 			/* Do delayed CE processing.   */
1210 			sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1211 			break;
1212 
1213 		case SCTP_CMD_ECN_ECNE:
1214 			/* Do delayed ECNE processing. */
1215 			new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1216 							chunk);
1217 			if (new_obj)
1218 				sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1219 						SCTP_CHUNK(new_obj));
1220 			break;
1221 
1222 		case SCTP_CMD_ECN_CWR:
1223 			/* Do delayed CWR processing.  */
1224 			sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1225 			break;
1226 
1227 		case SCTP_CMD_SETUP_T2:
1228 			sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1229 			break;
1230 
1231 		case SCTP_CMD_TIMER_START:
1232 			timer = &asoc->timers[cmd->obj.to];
1233 			timeout = asoc->timeouts[cmd->obj.to];
1234 			if (!timeout)
1235 				BUG();
1236 
1237 			timer->expires = jiffies + timeout;
1238 			sctp_association_hold(asoc);
1239 			add_timer(timer);
1240 			break;
1241 
1242 		case SCTP_CMD_TIMER_RESTART:
1243 			timer = &asoc->timers[cmd->obj.to];
1244 			timeout = asoc->timeouts[cmd->obj.to];
1245 			if (!mod_timer(timer, jiffies + timeout))
1246 				sctp_association_hold(asoc);
1247 			break;
1248 
1249 		case SCTP_CMD_TIMER_STOP:
1250 			timer = &asoc->timers[cmd->obj.to];
1251 			if (timer_pending(timer) && del_timer(timer))
1252 				sctp_association_put(asoc);
1253 			break;
1254 
1255 		case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1256 			chunk = cmd->obj.ptr;
1257 			t = sctp_assoc_choose_init_transport(asoc);
1258 			asoc->init_last_sent_to = t;
1259 			chunk->transport = t;
1260 			t->init_sent_count++;
1261 			break;
1262 
1263 		case SCTP_CMD_INIT_RESTART:
1264 			/* Do the needed accounting and updates
1265 			 * associated with restarting an initialization
1266 			 * timer. Only multiply the timeout by two if
1267 			 * all transports have been tried at the current
1268 			 * timeout.
1269 			 */
1270 			t = asoc->init_last_sent_to;
1271 			asoc->init_err_counter++;
1272 
1273 			if (t->init_sent_count > (asoc->init_cycle + 1)) {
1274 				asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] *= 2;
1275 				if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] >
1276 				    asoc->max_init_timeo) {
1277 					asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
1278 						asoc->max_init_timeo;
1279 				}
1280 				asoc->init_cycle++;
1281 				SCTP_DEBUG_PRINTK(
1282 					"T1 INIT Timeout adjustment"
1283 					" init_err_counter: %d"
1284 					" cycle: %d"
1285 					" timeout: %d\n",
1286 					asoc->init_err_counter,
1287 					asoc->init_cycle,
1288 					asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT]);
1289 			}
1290 
1291 			sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1292 					SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1293 			break;
1294 
1295 		case SCTP_CMD_COOKIEECHO_RESTART:
1296 			/* Do the needed accounting and updates
1297 			 * associated with restarting an initialization
1298 			 * timer. Only multiply the timeout by two if
1299 			 * all transports have been tried at the current
1300 			 * timeout.
1301 			 */
1302 			asoc->init_err_counter++;
1303 
1304 			asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] *= 2;
1305 			if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] >
1306 			    asoc->max_init_timeo) {
1307 				asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
1308 					asoc->max_init_timeo;
1309 			}
1310 			SCTP_DEBUG_PRINTK(
1311 				"T1 COOKIE Timeout adjustment"
1312 				" init_err_counter: %d"
1313 				" timeout: %d\n",
1314 				asoc->init_err_counter,
1315 				asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE]);
1316 
1317 			/* If we've sent any data bundled with
1318 			 * COOKIE-ECHO we need to resend.
1319 			 */
1320 			list_for_each(pos, &asoc->peer.transport_addr_list) {
1321 				t = list_entry(pos, struct sctp_transport,
1322 					       transports);
1323 				sctp_retransmit_mark(&asoc->outqueue, t, 0);
1324 			}
1325 
1326 			sctp_add_cmd_sf(commands,
1327 					SCTP_CMD_TIMER_RESTART,
1328 					SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1329 			break;
1330 
1331 		case SCTP_CMD_INIT_FAILED:
1332 			sctp_cmd_init_failed(commands, asoc, cmd->obj.u32);
1333 			break;
1334 
1335 		case SCTP_CMD_ASSOC_FAILED:
1336 			sctp_cmd_assoc_failed(commands, asoc, event_type,
1337 					      subtype, chunk, cmd->obj.u32);
1338 			break;
1339 
1340 		case SCTP_CMD_INIT_COUNTER_INC:
1341 			asoc->init_err_counter++;
1342 			break;
1343 
1344 		case SCTP_CMD_INIT_COUNTER_RESET:
1345 			asoc->init_err_counter = 0;
1346 			asoc->init_cycle = 0;
1347 			break;
1348 
1349 		case SCTP_CMD_REPORT_DUP:
1350 			sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1351 					     cmd->obj.u32);
1352 			break;
1353 
1354 		case SCTP_CMD_REPORT_BAD_TAG:
1355 			SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1356 			break;
1357 
1358 		case SCTP_CMD_STRIKE:
1359 			/* Mark one strike against a transport.  */
1360 			sctp_do_8_2_transport_strike(asoc, cmd->obj.transport);
1361 			break;
1362 
1363 		case SCTP_CMD_TRANSPORT_RESET:
1364 			t = cmd->obj.transport;
1365 			sctp_cmd_transport_reset(commands, asoc, t);
1366 			break;
1367 
1368 		case SCTP_CMD_TRANSPORT_ON:
1369 			t = cmd->obj.transport;
1370 			sctp_cmd_transport_on(commands, asoc, t, chunk);
1371 			break;
1372 
1373 		case SCTP_CMD_HB_TIMERS_START:
1374 			sctp_cmd_hb_timers_start(commands, asoc);
1375 			break;
1376 
1377 		case SCTP_CMD_HB_TIMER_UPDATE:
1378 			t = cmd->obj.transport;
1379 			sctp_cmd_hb_timer_update(commands, asoc, t);
1380 			break;
1381 
1382 		case SCTP_CMD_HB_TIMERS_STOP:
1383 			sctp_cmd_hb_timers_stop(commands, asoc);
1384 			break;
1385 
1386 		case SCTP_CMD_REPORT_ERROR:
1387 			error = cmd->obj.error;
1388 			break;
1389 
1390 		case SCTP_CMD_PROCESS_CTSN:
1391 			/* Dummy up a SACK for processing. */
1392 			sackh.cum_tsn_ack = cmd->obj.u32;
1393 			sackh.a_rwnd = 0;
1394 			sackh.num_gap_ack_blocks = 0;
1395 			sackh.num_dup_tsns = 0;
1396 			sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1397 					SCTP_SACKH(&sackh));
1398 			break;
1399 
1400 		case SCTP_CMD_DISCARD_PACKET:
1401 			/* We need to discard the whole packet.  */
1402 			chunk->pdiscard = 1;
1403 			break;
1404 
1405 		case SCTP_CMD_RTO_PENDING:
1406 			t = cmd->obj.transport;
1407 			t->rto_pending = 1;
1408 			break;
1409 
1410 		case SCTP_CMD_PART_DELIVER:
1411 			sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1412 						   GFP_ATOMIC);
1413 			break;
1414 
1415 		case SCTP_CMD_RENEGE:
1416 			sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1417 					 GFP_ATOMIC);
1418 			break;
1419 
1420 		case SCTP_CMD_SETUP_T4:
1421 			sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1422 			break;
1423 
1424 		case SCTP_CMD_PROCESS_OPERR:
1425 			sctp_cmd_process_operr(commands, asoc, chunk);
1426 			break;
1427 		case SCTP_CMD_CLEAR_INIT_TAG:
1428 			asoc->peer.i.init_tag = 0;
1429 			break;
1430 		case SCTP_CMD_DEL_NON_PRIMARY:
1431 			sctp_cmd_del_non_primary(asoc);
1432 			break;
1433 		case SCTP_CMD_T3_RTX_TIMERS_STOP:
1434 			sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1435 			break;
1436 		case SCTP_CMD_FORCE_PRIM_RETRAN:
1437 			t = asoc->peer.retran_path;
1438 			asoc->peer.retran_path = asoc->peer.primary_path;
1439 			error = sctp_outq_uncork(&asoc->outqueue);
1440 			local_cork = 0;
1441 			asoc->peer.retran_path = t;
1442 			break;
1443 		default:
1444 			printk(KERN_WARNING "Impossible command: %u, %p\n",
1445 			       cmd->verb, cmd->obj.ptr);
1446 			break;
1447 		};
1448 		if (error)
1449 			break;
1450 	}
1451 
1452 out:
1453 	if (local_cork)
1454 		sctp_outq_uncork(&asoc->outqueue);
1455 	return error;
1456 nomem:
1457 	error = -ENOMEM;
1458 	goto out;
1459 }
1460 
1461