1 /*********************************************************************
3 * Filename: irlap_event.c
5 * Description: IrLAP state machine implementation
6 * Status: Experimental.
7 * Author: Dag Brattli <dag@brattli.net>
8 * Created at: Sat Aug 16 00:59:29 1997
9 * Modified at: Sat Dec 25 21:07:57 1999
10 * Modified by: Dag Brattli <dag@brattli.net>
12 * Copyright (c) 1998-2000 Dag Brattli <dag@brattli.net>,
13 * Copyright (c) 1998 Thomas Davis <ratbert@radiks.net>
14 * All Rights Reserved.
15 * Copyright (c) 2000-2003 Jean Tourrilhes <jt@hpl.hp.com>
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License as
19 * published by the Free Software Foundation; either version 2 of
20 * the License, or (at your option) any later version.
22 * Neither Dag Brattli nor University of Tromsø admit liability nor
23 * provide warranty for any of this software. This material is
24 * provided "AS-IS" and at no charge.
26 ********************************************************************/
28 #include <linux/string.h>
29 #include <linux/kernel.h>
30 #include <linux/delay.h>
31 #include <linux/skbuff.h>
33 #include <net/irda/irda.h>
34 #include <net/irda/irlap_event.h>
36 #include <net/irda/timer.h>
37 #include <net/irda/irlap.h>
38 #include <net/irda/irlap_frame.h>
39 #include <net/irda/qos.h>
40 #include <net/irda/parameters.h>
41 #include <net/irda/irlmp.h> /* irlmp_flow_indication(), ... */
43 #include <net/irda/irda_device.h>
45 #ifdef CONFIG_IRDA_FAST_RR
46 int sysctl_fast_poll_increase = 50;
49 static int irlap_state_ndm (struct irlap_cb *self, IRLAP_EVENT event,
50 struct sk_buff *skb, struct irlap_info *info);
51 static int irlap_state_query (struct irlap_cb *self, IRLAP_EVENT event,
52 struct sk_buff *skb, struct irlap_info *info);
53 static int irlap_state_reply (struct irlap_cb *self, IRLAP_EVENT event,
54 struct sk_buff *skb, struct irlap_info *info);
55 static int irlap_state_conn (struct irlap_cb *self, IRLAP_EVENT event,
56 struct sk_buff *skb, struct irlap_info *info);
57 static int irlap_state_setup (struct irlap_cb *self, IRLAP_EVENT event,
58 struct sk_buff *skb, struct irlap_info *info);
59 static int irlap_state_offline(struct irlap_cb *self, IRLAP_EVENT event,
60 struct sk_buff *skb, struct irlap_info *info);
61 static int irlap_state_xmit_p (struct irlap_cb *self, IRLAP_EVENT event,
62 struct sk_buff *skb, struct irlap_info *info);
63 static int irlap_state_pclose (struct irlap_cb *self, IRLAP_EVENT event,
64 struct sk_buff *skb, struct irlap_info *info);
65 static int irlap_state_nrm_p (struct irlap_cb *self, IRLAP_EVENT event,
66 struct sk_buff *skb, struct irlap_info *info);
67 static int irlap_state_reset_wait(struct irlap_cb *self, IRLAP_EVENT event,
68 struct sk_buff *skb, struct irlap_info *info);
69 static int irlap_state_reset (struct irlap_cb *self, IRLAP_EVENT event,
70 struct sk_buff *skb, struct irlap_info *info);
71 static int irlap_state_nrm_s (struct irlap_cb *self, IRLAP_EVENT event,
72 struct sk_buff *skb, struct irlap_info *info);
73 static int irlap_state_xmit_s (struct irlap_cb *self, IRLAP_EVENT event,
74 struct sk_buff *skb, struct irlap_info *info);
75 static int irlap_state_sclose (struct irlap_cb *self, IRLAP_EVENT event,
76 struct sk_buff *skb, struct irlap_info *info);
77 static int irlap_state_reset_check(struct irlap_cb *, IRLAP_EVENT event,
78 struct sk_buff *, struct irlap_info *);
80 #ifdef CONFIG_IRDA_DEBUG
81 static const char *irlap_event[] = {
91 "RECV_DISCOVERY_XID_CMD",
92 "RECV_DISCOVERY_XID_RSP",
112 "SLOT_TIMER_EXPIRED",
113 "QUERY_TIMER_EXPIRED",
114 "FINAL_TIMER_EXPIRED",
115 "POLL_TIMER_EXPIRED",
116 "DISCOVERY_TIMER_EXPIRED",
118 "BACKOFF_TIMER_EXPIRED",
119 "MEDIA_BUSY_TIMER_EXPIRED",
121 #endif /* CONFIG_IRDA_DEBUG */
123 const char *irlap_state[] = {
141 static int (*state[])(struct irlap_cb *self, IRLAP_EVENT event,
142 struct sk_buff *skb, struct irlap_info *info) =
153 irlap_state_reset_wait,
158 irlap_state_reset_check,
162 * Function irda_poll_timer_expired (data)
164 * Poll timer has expired. Normally we must now send a RR frame to the
167 static void irlap_poll_timer_expired(void *data)
169 struct irlap_cb *self = (struct irlap_cb *) data;
171 IRDA_ASSERT(self != NULL, return;);
172 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
174 irlap_do_event(self, POLL_TIMER_EXPIRED, NULL, NULL);
178 * Calculate and set time before we will have to send back the pf bit
179 * to the peer. Use in primary.
180 * Make sure that state is XMIT_P/XMIT_S when calling this function
181 * (and that nobody messed up with the state). - Jean II
183 static void irlap_start_poll_timer(struct irlap_cb *self, int timeout)
185 IRDA_ASSERT(self != NULL, return;);
186 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
188 #ifdef CONFIG_IRDA_FAST_RR
190 * Send out the RR frames faster if our own transmit queue is empty, or
191 * if the peer is busy. The effect is a much faster conversation
193 if (skb_queue_empty(&self->txq) || self->remote_busy) {
194 if (self->fast_RR == TRUE) {
196 * Assert that the fast poll timer has not reached the
197 * normal poll timer yet
199 if (self->fast_RR_timeout < timeout) {
201 * FIXME: this should be a more configurable
204 self->fast_RR_timeout +=
205 (sysctl_fast_poll_increase * HZ/1000);
207 /* Use this fast(er) timeout instead */
208 timeout = self->fast_RR_timeout;
211 self->fast_RR = TRUE;
213 /* Start with just 0 ms */
214 self->fast_RR_timeout = 0;
218 self->fast_RR = FALSE;
220 IRDA_DEBUG(3, "%s(), timeout=%d (%ld)\n", __func__, timeout, jiffies);
221 #endif /* CONFIG_IRDA_FAST_RR */
224 irlap_do_event(self, POLL_TIMER_EXPIRED, NULL, NULL);
226 irda_start_timer(&self->poll_timer, timeout, self,
227 irlap_poll_timer_expired);
231 * Function irlap_do_event (event, skb, info)
233 * Rushes through the state machine without any delay. If state == XMIT
234 * then send queued data frames.
236 void irlap_do_event(struct irlap_cb *self, IRLAP_EVENT event,
237 struct sk_buff *skb, struct irlap_info *info)
241 if (!self || self->magic != LAP_MAGIC)
244 IRDA_DEBUG(3, "%s(), event = %s, state = %s\n", __func__,
245 irlap_event[event], irlap_state[self->state]);
247 ret = (*state[self->state])(self, event, skb, info);
250 * Check if there are any pending events that needs to be executed
252 switch (self->state) {
253 case LAP_XMIT_P: /* FALLTHROUGH */
256 * We just received the pf bit and are at the beginning
257 * of a new LAP transmit window.
258 * Check if there are any queued data frames, and do not
259 * try to disconnect link if we send any data frames, since
260 * that will change the state away form XMIT
262 IRDA_DEBUG(2, "%s() : queue len = %d\n", __func__,
263 skb_queue_len(&self->txq));
265 if (!skb_queue_empty(&self->txq)) {
266 /* Prevent race conditions with irlap_data_request() */
267 self->local_busy = TRUE;
269 /* Theory of operation.
270 * We send frames up to when we fill the window or
271 * reach line capacity. Those frames will queue up
272 * in the device queue, and the driver will slowly
274 * After each frame that we send, we poll the higher
275 * layer for more data. It's the right time to do
276 * that because the link layer need to perform the mtt
277 * and then send the first frame, so we can afford
278 * to send a bit of time in kernel space.
279 * The explicit flow indication allow to minimise
280 * buffers (== lower latency), to avoid higher layer
281 * polling via timers (== less context switches) and
282 * to implement a crude scheduler - Jean II */
284 /* Try to send away all queued data frames */
285 while ((skb = skb_dequeue(&self->txq)) != NULL) {
287 ret = (*state[self->state])(self, SEND_I_CMD,
289 /* Drop reference count.
290 * It will be increase as needed in
291 * irlap_send_data_xxx() */
294 /* Poll the higher layers for one more frame */
295 irlmp_flow_indication(self->notify.instance,
299 break; /* Try again later! */
301 /* Finished transmitting */
302 self->local_busy = FALSE;
303 } else if (self->disconnect_pending) {
304 self->disconnect_pending = FALSE;
306 ret = (*state[self->state])(self, DISCONNECT_REQUEST,
312 /* case LAP_RESET_WAIT: */
313 /* case LAP_RESET_CHECK: */
320 * Function irlap_state_ndm (event, skb, frame)
322 * NDM (Normal Disconnected Mode) state
325 static int irlap_state_ndm(struct irlap_cb *self, IRLAP_EVENT event,
326 struct sk_buff *skb, struct irlap_info *info)
328 discovery_t *discovery_rsp;
331 IRDA_ASSERT(self != NULL, return -1;);
332 IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
335 case CONNECT_REQUEST:
336 IRDA_ASSERT(self->netdev != NULL, return -1;);
338 if (self->media_busy) {
339 /* Note : this will never happen, because we test
340 * media busy in irlap_connect_request() and
341 * postpone the event... - Jean II */
342 IRDA_DEBUG(0, "%s(), CONNECT_REQUEST: media busy!\n",
345 /* Always switch state before calling upper layers */
346 irlap_next_state(self, LAP_NDM);
348 irlap_disconnect_indication(self, LAP_MEDIA_BUSY);
350 irlap_send_snrm_frame(self, &self->qos_rx);
352 /* Start Final-bit timer */
353 irlap_start_final_timer(self, self->final_timeout);
355 self->retry_count = 0;
356 irlap_next_state(self, LAP_SETUP);
360 /* Check if the frame contains and I field */
362 self->daddr = info->daddr;
363 self->caddr = info->caddr;
365 irlap_next_state(self, LAP_CONN);
367 irlap_connect_indication(self, skb);
369 IRDA_DEBUG(0, "%s(), SNRM frame does not "
370 "contain an I field!\n", __func__);
373 case DISCOVERY_REQUEST:
374 IRDA_ASSERT(info != NULL, return -1;);
376 if (self->media_busy) {
377 IRDA_DEBUG(1, "%s(), DISCOVERY_REQUEST: media busy!\n",
379 /* irlap->log.condition = MEDIA_BUSY; */
381 /* This will make IrLMP try again */
382 irlap_discovery_confirm(self, NULL);
383 /* Note : the discovery log is not cleaned up here,
384 * it will be done in irlap_discovery_request()
391 irlap_send_discovery_xid_frame(self, info->S, info->s, TRUE,
393 self->frame_sent = FALSE;
396 irlap_start_slot_timer(self, self->slot_timeout);
397 irlap_next_state(self, LAP_QUERY);
399 case RECV_DISCOVERY_XID_CMD:
400 IRDA_ASSERT(info != NULL, return -1;);
402 /* Assert that this is not the final slot */
403 if (info->s <= info->S) {
404 self->slot = irlap_generate_rand_time_slot(info->S,
406 if (self->slot == info->s) {
407 discovery_rsp = irlmp_get_discovery_response();
408 discovery_rsp->data.daddr = info->daddr;
410 irlap_send_discovery_xid_frame(self, info->S,
414 self->frame_sent = TRUE;
416 self->frame_sent = FALSE;
419 * Go to reply state until end of discovery to
420 * inhibit our own transmissions. Set the timer
421 * to not stay forever there... Jean II
423 irlap_start_query_timer(self, info->S, info->s);
424 irlap_next_state(self, LAP_REPLY);
426 /* This is the final slot. How is it possible ?
427 * This would happen is both discoveries are just slightly
428 * offset (if they are in sync, all packets are lost).
429 * Most often, all the discovery requests will be received
430 * in QUERY state (see my comment there), except for the
431 * last frame that will come here.
432 * The big trouble when it happen is that active discovery
433 * doesn't happen, because nobody answer the discoveries
434 * frame of the other guy, so the log shows up empty.
435 * What should we do ?
436 * Not much. It's too late to answer those discovery frames,
437 * so we just pass the info to IrLMP who will put it in the
438 * log (and post an event).
439 * Another cause would be devices that do discovery much
440 * slower than us, however the latest fixes should minimise
444 IRDA_DEBUG(1, "%s(), Receiving final discovery request, missed the discovery slots :-(\n", __func__);
446 /* Last discovery request -> in the log */
447 irlap_discovery_indication(self, info->discovery);
450 case MEDIA_BUSY_TIMER_EXPIRED:
451 /* A bunch of events may be postponed because the media is
452 * busy (usually immediately after we close a connection),
453 * or while we are doing discovery (state query/reply).
454 * In all those cases, the media busy flag will be cleared
455 * when it's OK for us to process those postponed events.
456 * This event is not mentioned in the state machines in the
457 * IrLAP spec. It's because they didn't consider Ultra and
458 * postponing connection request is optional.
460 #ifdef CONFIG_IRDA_ULTRA
461 /* Send any pending Ultra frames if any */
462 if (!skb_queue_empty(&self->txq_ultra)) {
463 /* We don't send the frame, just post an event.
464 * Also, previously this code was in timer.c...
466 ret = (*state[self->state])(self, SEND_UI_FRAME,
469 #endif /* CONFIG_IRDA_ULTRA */
470 /* Check if we should try to connect.
471 * This code was previously in irlap_do_event() */
472 if (self->connect_pending) {
473 self->connect_pending = FALSE;
475 /* This one *should* not pend in this state, except
476 * if a socket try to connect and immediately
477 * disconnect. - clear - Jean II */
478 if (self->disconnect_pending)
479 irlap_disconnect_indication(self, LAP_DISC_INDICATION);
481 ret = (*state[self->state])(self,
484 self->disconnect_pending = FALSE;
486 /* Note : one way to test if this code works well (including
487 * media busy and small busy) is to create a user space
488 * application generating an Ultra packet every 3.05 sec (or
489 * 2.95 sec) and to see how it interact with discovery.
490 * It's fairly easy to check that no packet is lost, that the
491 * packets are postponed during discovery and that after
492 * discovery indication you have a 100ms "gap".
493 * As connection request and Ultra are now processed the same
494 * way, this avoid the tedious job of trying IrLAP connection
495 * in all those cases...
498 #ifdef CONFIG_IRDA_ULTRA
502 /* Only allowed to repeat an operation twice */
503 for (i=0; ((i<2) && (self->media_busy == FALSE)); i++) {
504 skb = skb_dequeue(&self->txq_ultra);
506 irlap_send_ui_frame(self, skb, CBROADCAST,
510 /* irlap_send_ui_frame() won't increase skb reference
511 * count, so no dev_kfree_skb() - Jean II */
514 /* Force us to listen 500 ms again */
515 irda_device_set_media_busy(self->netdev, TRUE);
520 /* Only accept broadcast frames in NDM mode */
521 if (info->caddr != CBROADCAST) {
522 IRDA_DEBUG(0, "%s(), not a broadcast frame!\n",
525 irlap_unitdata_indication(self, skb);
527 #endif /* CONFIG_IRDA_ULTRA */
529 /* Remove test frame header */
530 skb_pull(skb, sizeof(struct test_frame));
533 * Send response. This skb will not be sent out again, and
534 * will only be used to send out the same info as the cmd
536 irlap_send_test_frame(self, CBROADCAST, info->daddr, skb);
539 IRDA_DEBUG(0, "%s() not implemented!\n", __func__);
542 IRDA_DEBUG(2, "%s(), Unknown event %s\n", __func__,
552 * Function irlap_state_query (event, skb, info)
557 static int irlap_state_query(struct irlap_cb *self, IRLAP_EVENT event,
558 struct sk_buff *skb, struct irlap_info *info)
562 IRDA_ASSERT(self != NULL, return -1;);
563 IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
566 case RECV_DISCOVERY_XID_RSP:
567 IRDA_ASSERT(info != NULL, return -1;);
568 IRDA_ASSERT(info->discovery != NULL, return -1;);
570 IRDA_DEBUG(4, "%s(), daddr=%08x\n", __func__,
571 info->discovery->data.daddr);
573 if (!self->discovery_log) {
574 IRDA_WARNING("%s: discovery log is gone! "
575 "maybe the discovery timeout has been set"
576 " too short?\n", __func__);
579 hashbin_insert(self->discovery_log,
580 (irda_queue_t *) info->discovery,
581 info->discovery->data.daddr, NULL);
584 /* irlap_next_state(self, LAP_QUERY); */
587 case RECV_DISCOVERY_XID_CMD:
588 /* Yes, it is possible to receive those frames in this mode.
589 * Note that most often the last discovery request won't
590 * occur here but in NDM state (see my comment there).
591 * What should we do ?
592 * Not much. We are currently performing our own discovery,
593 * therefore we can't answer those frames. We don't want
594 * to change state either. We just pass the info to
595 * IrLMP who will put it in the log (and post an event).
599 IRDA_ASSERT(info != NULL, return -1;);
601 IRDA_DEBUG(1, "%s(), Receiving discovery request (s = %d) while performing discovery :-(\n", __func__, info->s);
603 /* Last discovery request ? */
605 irlap_discovery_indication(self, info->discovery);
607 case SLOT_TIMER_EXPIRED:
609 * Wait a little longer if we detect an incoming frame. This
610 * is not mentioned in the spec, but is a good thing to do,
611 * since we want to work even with devices that violate the
612 * timing requirements.
614 if (irda_device_is_receiving(self->netdev) && !self->add_wait) {
615 IRDA_DEBUG(2, "%s(), device is slow to answer, "
616 "waiting some more!\n", __func__);
617 irlap_start_slot_timer(self, msecs_to_jiffies(10));
618 self->add_wait = TRUE;
621 self->add_wait = FALSE;
623 if (self->s < self->S) {
624 irlap_send_discovery_xid_frame(self, self->S,
626 self->discovery_cmd);
628 irlap_start_slot_timer(self, self->slot_timeout);
631 irlap_next_state(self, LAP_QUERY);
633 /* This is the final slot! */
634 irlap_send_discovery_xid_frame(self, self->S, 0xff,
636 self->discovery_cmd);
638 /* Always switch state before calling upper layers */
639 irlap_next_state(self, LAP_NDM);
642 * We are now finished with the discovery procedure,
643 * so now we must return the results
645 irlap_discovery_confirm(self, self->discovery_log);
647 /* IrLMP should now have taken care of the log */
648 self->discovery_log = NULL;
652 IRDA_DEBUG(2, "%s(), Unknown event %s\n", __func__,
662 * Function irlap_state_reply (self, event, skb, info)
664 * REPLY, we have received a XID discovery frame from a device and we
665 * are waiting for the right time slot to send a response XID frame
668 static int irlap_state_reply(struct irlap_cb *self, IRLAP_EVENT event,
669 struct sk_buff *skb, struct irlap_info *info)
671 discovery_t *discovery_rsp;
674 IRDA_DEBUG(4, "%s()\n", __func__);
676 IRDA_ASSERT(self != NULL, return -1;);
677 IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
680 case QUERY_TIMER_EXPIRED:
681 IRDA_DEBUG(0, "%s(), QUERY_TIMER_EXPIRED <%ld>\n",
683 irlap_next_state(self, LAP_NDM);
685 case RECV_DISCOVERY_XID_CMD:
686 IRDA_ASSERT(info != NULL, return -1;);
688 if (info->s == 0xff) {
689 del_timer(&self->query_timer);
691 /* info->log.condition = REMOTE; */
693 /* Always switch state before calling upper layers */
694 irlap_next_state(self, LAP_NDM);
696 irlap_discovery_indication(self, info->discovery);
698 /* If it's our slot, send our reply */
699 if ((info->s >= self->slot) && (!self->frame_sent)) {
700 discovery_rsp = irlmp_get_discovery_response();
701 discovery_rsp->data.daddr = info->daddr;
703 irlap_send_discovery_xid_frame(self, info->S,
708 self->frame_sent = TRUE;
710 /* Readjust our timer to accomodate devices
711 * doing faster or slower discovery than us...
713 irlap_start_query_timer(self, info->S, info->s);
716 //irlap_next_state(self, LAP_REPLY);
720 IRDA_DEBUG(1, "%s(), Unknown event %d, %s\n", __func__,
721 event, irlap_event[event]);
730 * Function irlap_state_conn (event, skb, info)
732 * CONN, we have received a SNRM command and is waiting for the upper
733 * layer to accept or refuse connection
736 static int irlap_state_conn(struct irlap_cb *self, IRLAP_EVENT event,
737 struct sk_buff *skb, struct irlap_info *info)
741 IRDA_DEBUG(4, "%s(), event=%s\n", __func__, irlap_event[ event]);
743 IRDA_ASSERT(self != NULL, return -1;);
744 IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
747 case CONNECT_RESPONSE:
748 skb_pull(skb, sizeof(struct snrm_frame));
750 IRDA_ASSERT(self->netdev != NULL, return -1;);
752 irlap_qos_negotiate(self, skb);
754 irlap_initiate_connection_state(self);
757 * Applying the parameters now will make sure we change speed
758 * *after* we have sent the next frame
760 irlap_apply_connection_parameters(self, FALSE);
763 * Sending this frame will force a speed change after it has
764 * been sent (i.e. the frame will be sent at 9600).
766 irlap_send_ua_response_frame(self, &self->qos_rx);
770 * We are allowed to send two frames, but this may increase
771 * the connect latency, so lets not do it for now.
773 /* This is full of good intentions, but doesn't work in
775 * After sending the first UA response, we switch the
776 * dongle to the negotiated speed, which is usually
777 * different than 9600 kb/s.
778 * From there, there is two solutions :
779 * 1) The other end has received the first UA response :
780 * it will set up the connection, move to state LAP_NRM_P,
781 * and will ignore and drop the second UA response.
782 * Actually, it's even worse : the other side will almost
783 * immediately send a RR that will likely collide with the
784 * UA response (depending on negotiated turnaround).
785 * 2) The other end has not received the first UA response,
786 * will stay at 9600 and will never see the second UA response.
788 irlap_send_ua_response_frame(self, &self->qos_rx);
792 * The WD-timer could be set to the duration of the P-timer
793 * for this case, but it is recommended to use twice the
794 * value (note 3 IrLAP p. 60).
796 irlap_start_wd_timer(self, self->wd_timeout);
797 irlap_next_state(self, LAP_NRM_S);
800 case RECV_DISCOVERY_XID_CMD:
801 IRDA_DEBUG(3, "%s(), event RECV_DISCOVER_XID_CMD!\n",
803 irlap_next_state(self, LAP_NDM);
806 case DISCONNECT_REQUEST:
807 IRDA_DEBUG(0, "%s(), Disconnect request!\n", __func__);
808 irlap_send_dm_frame(self);
809 irlap_next_state( self, LAP_NDM);
810 irlap_disconnect_indication(self, LAP_DISC_INDICATION);
813 IRDA_DEBUG(1, "%s(), Unknown event %d, %s\n", __func__,
814 event, irlap_event[event]);
824 * Function irlap_state_setup (event, skb, frame)
826 * SETUP state, The local layer has transmitted a SNRM command frame to
827 * a remote peer layer and is awaiting a reply .
830 static int irlap_state_setup(struct irlap_cb *self, IRLAP_EVENT event,
831 struct sk_buff *skb, struct irlap_info *info)
835 IRDA_DEBUG(4, "%s()\n", __func__);
837 IRDA_ASSERT(self != NULL, return -1;);
838 IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
841 case FINAL_TIMER_EXPIRED:
842 if (self->retry_count < self->N3) {
844 * Perform random backoff, Wait a random number of time units, minimum
845 * duration half the time taken to transmitt a SNRM frame, maximum duration
846 * 1.5 times the time taken to transmit a SNRM frame. So this time should
847 * between 15 msecs and 45 msecs.
849 irlap_start_backoff_timer(self, msecs_to_jiffies(20 +
852 /* Always switch state before calling upper layers */
853 irlap_next_state(self, LAP_NDM);
855 irlap_disconnect_indication(self, LAP_FOUND_NONE);
858 case BACKOFF_TIMER_EXPIRED:
859 irlap_send_snrm_frame(self, &self->qos_rx);
860 irlap_start_final_timer(self, self->final_timeout);
864 IRDA_DEBUG(4, "%s(), SNRM battle!\n", __func__);
866 IRDA_ASSERT(skb != NULL, return 0;);
867 IRDA_ASSERT(info != NULL, return 0;);
870 * The device with the largest device address wins the battle
871 * (both have sent a SNRM command!)
873 if (info &&(info->daddr > self->saddr)) {
874 del_timer(&self->final_timer);
875 irlap_initiate_connection_state(self);
877 IRDA_ASSERT(self->netdev != NULL, return -1;);
879 skb_pull(skb, sizeof(struct snrm_frame));
881 irlap_qos_negotiate(self, skb);
883 /* Send UA frame and then change link settings */
884 irlap_apply_connection_parameters(self, FALSE);
885 irlap_send_ua_response_frame(self, &self->qos_rx);
887 irlap_next_state(self, LAP_NRM_S);
888 irlap_connect_confirm(self, skb);
891 * The WD-timer could be set to the duration of the
892 * P-timer for this case, but it is recommended
893 * to use twice the value (note 3 IrLAP p. 60).
895 irlap_start_wd_timer(self, self->wd_timeout);
897 /* We just ignore the other device! */
898 irlap_next_state(self, LAP_SETUP);
903 del_timer(&self->final_timer);
905 /* Initiate connection state */
906 irlap_initiate_connection_state(self);
908 /* Negotiate connection parameters */
909 IRDA_ASSERT(skb->len > 10, return -1;);
911 skb_pull(skb, sizeof(struct ua_frame));
913 IRDA_ASSERT(self->netdev != NULL, return -1;);
915 irlap_qos_negotiate(self, skb);
917 /* Set the new link setting *now* (before the rr frame) */
918 irlap_apply_connection_parameters(self, TRUE);
919 self->retry_count = 0;
921 /* Wait for turnaround time to give a chance to the other
922 * device to be ready to receive us.
923 * Note : the time to switch speed is typically larger
924 * than the turnaround time, but as we don't have the other
925 * side speed switch time, that's our best guess...
927 irlap_wait_min_turn_around(self, &self->qos_tx);
929 /* This frame will actually be sent at the new speed */
930 irlap_send_rr_frame(self, CMD_FRAME);
932 /* The timer is set to half the normal timer to quickly
933 * detect a failure to negociate the new connection
934 * parameters. IrLAP 6.11.3.2, note 3.
935 * Note that currently we don't process this failure
936 * properly, as we should do a quick disconnect.
938 irlap_start_final_timer(self, self->final_timeout/2);
939 irlap_next_state(self, LAP_NRM_P);
941 irlap_connect_confirm(self, skb);
943 case RECV_DM_RSP: /* FALLTHROUGH */
945 del_timer(&self->final_timer);
946 irlap_next_state(self, LAP_NDM);
948 irlap_disconnect_indication(self, LAP_DISC_INDICATION);
951 IRDA_DEBUG(1, "%s(), Unknown event %d, %s\n", __func__,
952 event, irlap_event[event]);
961 * Function irlap_state_offline (self, event, skb, info)
963 * OFFLINE state, not used for now!
966 static int irlap_state_offline(struct irlap_cb *self, IRLAP_EVENT event,
967 struct sk_buff *skb, struct irlap_info *info)
969 IRDA_DEBUG( 0, "%s(), Unknown event\n", __func__);
975 * Function irlap_state_xmit_p (self, event, skb, info)
977 * XMIT, Only the primary station has right to transmit, and we
978 * therefore do not expect to receive any transmissions from other
982 static int irlap_state_xmit_p(struct irlap_cb *self, IRLAP_EVENT event,
983 struct sk_buff *skb, struct irlap_info *info)
990 * Only send frame if send-window > 0.
992 if ((self->window > 0) && (!self->remote_busy)) {
994 #ifdef CONFIG_IRDA_DYNAMIC_WINDOW
995 struct sk_buff *skb_next;
997 /* With DYNAMIC_WINDOW, we keep the window size
998 * maximum, and adapt on the packets we are sending.
999 * At 115k, we can send only 2 packets of 2048 bytes
1000 * in a 500 ms turnaround. Without this option, we
1001 * would always limit the window to 2. With this
1002 * option, if we send smaller packets, we can send
1003 * up to 7 of them (always depending on QoS).
1006 /* Look at the next skb. This is safe, as we are
1007 * the only consumer of the Tx queue (if we are not,
1008 * we have other problems) - Jean II */
1009 skb_next = skb_peek(&self->txq);
1011 /* Check if a subsequent skb exist and would fit in
1012 * the current window (with respect to turnaround
1014 * This allow us to properly mark the current packet
1015 * with the pf bit, to avoid falling back on the
1016 * second test below, and avoid waiting the
1017 * end of the window and sending a extra RR.
1018 * Note : (skb_next != NULL) <=> (skb_queue_len() > 0)
1020 nextfit = ((skb_next != NULL) &&
1021 ((skb_next->len + skb->len) <=
1025 * The current packet may not fit ! Because of test
1026 * above, this should not happen any more !!!
1027 * Test if we have transmitted more bytes over the
1028 * link than its possible to do with the current
1029 * speed and turn-around-time.
1031 if((!nextfit) && (skb->len > self->bytes_left)) {
1032 IRDA_DEBUG(0, "%s(), Not allowed to transmit"
1033 " more bytes!\n", __func__);
1034 /* Requeue the skb */
1035 skb_queue_head(&self->txq, skb_get(skb));
1037 * We should switch state to LAP_NRM_P, but
1038 * that is not possible since we must be sure
1039 * that we poll the other side. Since we have
1040 * used up our time, the poll timer should
1041 * trigger anyway now, so we just wait for it
1045 * Sorry, but that's not totally true. If
1046 * we send 2000B packets, we may wait another
1047 * 1000B until our turnaround expire. That's
1048 * why we need to be proactive in avoiding
1049 * coming here. - Jean II
1054 /* Substract space used by this skb */
1055 self->bytes_left -= skb->len;
1056 #else /* CONFIG_IRDA_DYNAMIC_WINDOW */
1057 /* Window has been adjusted for the max packet
1058 * size, so much simpler... - Jean II */
1059 nextfit = !skb_queue_empty(&self->txq);
1060 #endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
1062 * Send data with poll bit cleared only if window > 1
1063 * and there is more frames after this one to be sent
1065 if ((self->window > 1) && (nextfit)) {
1066 /* More packet to send in current window */
1067 irlap_send_data_primary(self, skb);
1068 irlap_next_state(self, LAP_XMIT_P);
1070 /* Final packet of window */
1071 irlap_send_data_primary_poll(self, skb);
1074 * Make sure state machine does not try to send
1079 #ifdef CONFIG_IRDA_FAST_RR
1080 /* Peer may want to reply immediately */
1081 self->fast_RR = FALSE;
1082 #endif /* CONFIG_IRDA_FAST_RR */
1084 IRDA_DEBUG(4, "%s(), Unable to send! remote busy?\n",
1086 skb_queue_head(&self->txq, skb_get(skb));
1089 * The next ret is important, because it tells
1090 * irlap_next_state _not_ to deliver more frames
1095 case POLL_TIMER_EXPIRED:
1096 IRDA_DEBUG(3, "%s(), POLL_TIMER_EXPIRED <%ld>\n",
1098 irlap_send_rr_frame(self, CMD_FRAME);
1099 /* Return to NRM properly - Jean II */
1100 self->window = self->window_size;
1101 #ifdef CONFIG_IRDA_DYNAMIC_WINDOW
1102 /* Allowed to transmit a maximum number of bytes again. */
1103 self->bytes_left = self->line_capacity;
1104 #endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
1105 irlap_start_final_timer(self, self->final_timeout);
1106 irlap_next_state(self, LAP_NRM_P);
1108 case DISCONNECT_REQUEST:
1109 del_timer(&self->poll_timer);
1110 irlap_wait_min_turn_around(self, &self->qos_tx);
1111 irlap_send_disc_frame(self);
1112 irlap_flush_all_queues(self);
1113 irlap_start_final_timer(self, self->final_timeout);
1114 self->retry_count = 0;
1115 irlap_next_state(self, LAP_PCLOSE);
1118 /* Nothing to do, irlap_do_event() will send the packet
1119 * when we return... - Jean II */
1122 IRDA_DEBUG(0, "%s(), Unknown event %s\n",
1123 __func__, irlap_event[event]);
1132 * Function irlap_state_pclose (event, skb, info)
1136 static int irlap_state_pclose(struct irlap_cb *self, IRLAP_EVENT event,
1137 struct sk_buff *skb, struct irlap_info *info)
1141 IRDA_DEBUG(1, "%s()\n", __func__);
1143 IRDA_ASSERT(self != NULL, return -1;);
1144 IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
1147 case RECV_UA_RSP: /* FALLTHROUGH */
1149 del_timer(&self->final_timer);
1151 /* Set new link parameters */
1152 irlap_apply_default_connection_parameters(self);
1154 /* Always switch state before calling upper layers */
1155 irlap_next_state(self, LAP_NDM);
1157 irlap_disconnect_indication(self, LAP_DISC_INDICATION);
1159 case FINAL_TIMER_EXPIRED:
1160 if (self->retry_count < self->N3) {
1161 irlap_wait_min_turn_around(self, &self->qos_tx);
1162 irlap_send_disc_frame(self);
1163 irlap_start_final_timer(self, self->final_timeout);
1164 self->retry_count++;
1167 irlap_apply_default_connection_parameters(self);
1169 /* Always switch state before calling upper layers */
1170 irlap_next_state(self, LAP_NDM);
1172 irlap_disconnect_indication(self, LAP_NO_RESPONSE);
1176 IRDA_DEBUG(1, "%s(), Unknown event %d\n", __func__, event);
1185 * Function irlap_state_nrm_p (self, event, skb, info)
1187 * NRM_P (Normal Response Mode as Primary), The primary station has given
1188 * permissions to a secondary station to transmit IrLAP resonse frames
1189 * (by sending a frame with the P bit set). The primary station will not
1190 * transmit any frames and is expecting to receive frames only from the
1191 * secondary to which transmission permissions has been given.
1193 static int irlap_state_nrm_p(struct irlap_cb *self, IRLAP_EVENT event,
1194 struct sk_buff *skb, struct irlap_info *info)
1201 case RECV_I_RSP: /* Optimize for the common case */
1202 if (unlikely(skb->len <= LAP_ADDR_HEADER + LAP_CTRL_HEADER)) {
1204 * Input validation check: a stir4200/mcp2150
1205 * combination sometimes results in an empty i:rsp.
1206 * This makes no sense; we can just ignore the frame
1207 * and send an rr:cmd immediately. This happens before
1208 * changing nr or ns so triggers a retransmit
1210 irlap_wait_min_turn_around(self, &self->qos_tx);
1211 irlap_send_rr_frame(self, CMD_FRAME);
1215 /* FIXME: must check for remote_busy below */
1216 #ifdef CONFIG_IRDA_FAST_RR
1218 * Reset the fast_RR so we can use the fast RR code with
1219 * full speed the next time since peer may have more frames
1222 self->fast_RR = FALSE;
1223 #endif /* CONFIG_IRDA_FAST_RR */
1224 IRDA_ASSERT( info != NULL, return -1;);
1226 ns_status = irlap_validate_ns_received(self, info->ns);
1227 nr_status = irlap_validate_nr_received(self, info->nr);
1230 * Check for expected I(nformation) frame
1232 if ((ns_status == NS_EXPECTED) && (nr_status == NR_EXPECTED)) {
1234 /* Update Vr (next frame for us to receive) */
1235 self->vr = (self->vr + 1) % 8;
1237 /* Update Nr received, cleanup our retry queue */
1238 irlap_update_nr_received(self, info->nr);
1241 * Got expected NR, so reset the
1242 * retry_count. This is not done by IrLAP spec,
1245 self->retry_count = 0;
1246 self->ack_required = TRUE;
1248 /* poll bit cleared? */
1250 /* Keep state, do not move this line */
1251 irlap_next_state(self, LAP_NRM_P);
1253 irlap_data_indication(self, skb, FALSE);
1255 /* No longer waiting for pf */
1256 del_timer(&self->final_timer);
1258 irlap_wait_min_turn_around(self, &self->qos_tx);
1260 /* Call higher layer *before* changing state
1261 * to give them a chance to send data in the
1264 irlap_data_indication(self, skb, FALSE);
1266 /* XMIT states are the most dangerous state
1267 * to be in, because user requests are
1268 * processed directly and may change state.
1269 * On the other hand, in NDM_P, those
1270 * requests are queued and we will process
1271 * them when we return to irlap_do_event().
1274 irlap_next_state(self, LAP_XMIT_P);
1276 /* This is the last frame.
1277 * Make sure it's always called in XMIT state.
1279 irlap_start_poll_timer(self, self->poll_timeout);
1284 /* Unexpected next to send (Ns) */
1285 if ((ns_status == NS_UNEXPECTED) && (nr_status == NR_EXPECTED))
1288 irlap_update_nr_received(self, info->nr);
1291 * Wait until the last frame before doing
1296 irlap_next_state(self, LAP_NRM_P);
1299 "%s(), missing or duplicate frame!\n",
1302 /* Update Nr received */
1303 irlap_update_nr_received(self, info->nr);
1305 irlap_wait_min_turn_around(self, &self->qos_tx);
1306 irlap_send_rr_frame(self, CMD_FRAME);
1308 self->ack_required = FALSE;
1310 irlap_start_final_timer(self, self->final_timeout);
1311 irlap_next_state(self, LAP_NRM_P);
1316 * Unexpected next to receive (Nr)
1318 if ((ns_status == NS_EXPECTED) && (nr_status == NR_UNEXPECTED))
1321 self->vr = (self->vr + 1) % 8;
1323 /* Update Nr received */
1324 irlap_update_nr_received(self, info->nr);
1326 /* Resend rejected frames */
1327 irlap_resend_rejected_frames(self, CMD_FRAME);
1329 self->ack_required = FALSE;
1331 /* Make sure we account for the time
1332 * to transmit our frames. See comemnts
1333 * in irlap_send_data_primary_poll().
1335 irlap_start_final_timer(self, 2 * self->final_timeout);
1337 /* Keep state, do not move this line */
1338 irlap_next_state(self, LAP_NRM_P);
1340 irlap_data_indication(self, skb, FALSE);
1343 * Do not resend frames until the last
1344 * frame has arrived from the other
1345 * device. This is not documented in
1348 self->vr = (self->vr + 1) % 8;
1350 /* Update Nr received */
1351 irlap_update_nr_received(self, info->nr);
1353 self->ack_required = FALSE;
1355 /* Keep state, do not move this line!*/
1356 irlap_next_state(self, LAP_NRM_P);
1358 irlap_data_indication(self, skb, FALSE);
1363 * Unexpected next to send (Ns) and next to receive (Nr)
1364 * Not documented by IrLAP!
1366 if ((ns_status == NS_UNEXPECTED) &&
1367 (nr_status == NR_UNEXPECTED))
1369 IRDA_DEBUG(4, "%s(), unexpected nr and ns!\n",
1372 /* Resend rejected frames */
1373 irlap_resend_rejected_frames(self, CMD_FRAME);
1375 /* Give peer some time to retransmit!
1376 * But account for our own Tx. */
1377 irlap_start_final_timer(self, 2 * self->final_timeout);
1379 /* Keep state, do not move this line */
1380 irlap_next_state(self, LAP_NRM_P);
1382 /* Update Nr received */
1383 /* irlap_update_nr_received( info->nr); */
1385 self->ack_required = FALSE;
1393 if ((nr_status == NR_INVALID) || (ns_status == NS_INVALID)) {
1395 del_timer(&self->final_timer);
1397 irlap_next_state(self, LAP_RESET_WAIT);
1399 irlap_disconnect_indication(self, LAP_RESET_INDICATION);
1400 self->xmitflag = TRUE;
1402 del_timer(&self->final_timer);
1404 irlap_disconnect_indication(self, LAP_RESET_INDICATION);
1406 self->xmitflag = FALSE;
1410 IRDA_DEBUG(1, "%s(), Not implemented!\n", __func__);
1411 IRDA_DEBUG(1, "%s(), event=%s, ns_status=%d, nr_status=%d\n",
1412 __func__, irlap_event[event], ns_status, nr_status);
1415 /* Poll bit cleared? */
1417 irlap_data_indication(self, skb, TRUE);
1418 irlap_next_state(self, LAP_NRM_P);
1420 del_timer(&self->final_timer);
1421 irlap_data_indication(self, skb, TRUE);
1422 irlap_next_state(self, LAP_XMIT_P);
1423 IRDA_DEBUG(1, "%s: RECV_UI_FRAME: next state %s\n", __func__, irlap_state[self->state]);
1424 irlap_start_poll_timer(self, self->poll_timeout);
1429 * If you get a RR, the remote isn't busy anymore,
1430 * no matter what the NR
1432 self->remote_busy = FALSE;
1434 /* Stop final timer */
1435 del_timer(&self->final_timer);
1440 ret = irlap_validate_nr_received(self, info->nr);
1441 if (ret == NR_EXPECTED) {
1442 /* Update Nr received */
1443 irlap_update_nr_received(self, info->nr);
1446 * Got expected NR, so reset the retry_count. This
1447 * is not done by the IrLAP standard , which is
1450 self->retry_count = 0;
1451 irlap_wait_min_turn_around(self, &self->qos_tx);
1453 irlap_next_state(self, LAP_XMIT_P);
1455 /* Start poll timer */
1456 irlap_start_poll_timer(self, self->poll_timeout);
1457 } else if (ret == NR_UNEXPECTED) {
1458 IRDA_ASSERT(info != NULL, return -1;);
1463 /* Update Nr received */
1464 irlap_update_nr_received(self, info->nr);
1466 IRDA_DEBUG(4, "RECV_RR_FRAME: Retrans:%d, nr=%d, va=%d, "
1468 self->retry_count, info->nr, self->va,
1469 self->vs, self->vr);
1471 /* Resend rejected frames */
1472 irlap_resend_rejected_frames(self, CMD_FRAME);
1473 irlap_start_final_timer(self, self->final_timeout * 2);
1475 irlap_next_state(self, LAP_NRM_P);
1476 } else if (ret == NR_INVALID) {
1477 IRDA_DEBUG(1, "%s(), Received RR with "
1478 "invalid nr !\n", __func__);
1480 irlap_next_state(self, LAP_RESET_WAIT);
1482 irlap_disconnect_indication(self, LAP_RESET_INDICATION);
1483 self->xmitflag = TRUE;
1487 IRDA_ASSERT(info != NULL, return -1;);
1489 /* Stop final timer */
1490 del_timer(&self->final_timer);
1491 self->remote_busy = TRUE;
1493 /* Update Nr received */
1494 irlap_update_nr_received(self, info->nr);
1495 irlap_next_state(self, LAP_XMIT_P);
1497 /* Start poll timer */
1498 irlap_start_poll_timer(self, self->poll_timeout);
1501 del_timer(&self->final_timer);
1502 self->xmitflag = TRUE;
1503 irlap_next_state(self, LAP_RESET_WAIT);
1504 irlap_reset_indication(self);
1506 case FINAL_TIMER_EXPIRED:
1508 * We are allowed to wait for additional 300 ms if
1509 * final timer expires when we are in the middle
1510 * of receiving a frame (page 45, IrLAP). Check that
1511 * we only do this once for each frame.
1513 if (irda_device_is_receiving(self->netdev) && !self->add_wait) {
1514 IRDA_DEBUG(1, "FINAL_TIMER_EXPIRED when receiving a "
1515 "frame! Waiting a little bit more!\n");
1516 irlap_start_final_timer(self, msecs_to_jiffies(300));
1519 * Don't allow this to happen one more time in a row,
1520 * or else we can get a pretty tight loop here if
1521 * if we only receive half a frame. DB.
1523 self->add_wait = TRUE;
1526 self->add_wait = FALSE;
1528 /* N2 is the disconnect timer. Until we reach it, we retry */
1529 if (self->retry_count < self->N2) {
1530 if (skb_peek(&self->wx_list) == NULL) {
1531 /* Retry sending the pf bit to the secondary */
1532 IRDA_DEBUG(4, "nrm_p: resending rr");
1533 irlap_wait_min_turn_around(self, &self->qos_tx);
1534 irlap_send_rr_frame(self, CMD_FRAME);
1536 IRDA_DEBUG(4, "nrm_p: resend frames");
1537 irlap_resend_rejected_frames(self, CMD_FRAME);
1540 irlap_start_final_timer(self, self->final_timeout);
1541 self->retry_count++;
1542 IRDA_DEBUG(4, "irlap_state_nrm_p: FINAL_TIMER_EXPIRED:"
1543 " retry_count=%d\n", self->retry_count);
1545 /* Early warning event. I'm using a pretty liberal
1546 * interpretation of the spec and generate an event
1547 * every time the timer is multiple of N1 (and not
1548 * only the first time). This allow application
1549 * to know precisely if connectivity restart...
1551 if((self->retry_count % self->N1) == 0)
1552 irlap_status_indication(self,
1553 STATUS_NO_ACTIVITY);
1557 irlap_apply_default_connection_parameters(self);
1559 /* Always switch state before calling upper layers */
1560 irlap_next_state(self, LAP_NDM);
1561 irlap_disconnect_indication(self, LAP_NO_RESPONSE);
1565 irlap_update_nr_received(self, info->nr);
1566 if (self->remote_busy) {
1567 irlap_wait_min_turn_around(self, &self->qos_tx);
1568 irlap_send_rr_frame(self, CMD_FRAME);
1570 irlap_resend_rejected_frames(self, CMD_FRAME);
1571 irlap_start_final_timer(self, 2 * self->final_timeout);
1574 irlap_update_nr_received(self, info->nr);
1575 if (self->remote_busy) {
1576 irlap_wait_min_turn_around(self, &self->qos_tx);
1577 irlap_send_rr_frame(self, CMD_FRAME);
1579 irlap_resend_rejected_frame(self, CMD_FRAME);
1580 irlap_start_final_timer(self, 2 * self->final_timeout);
1583 IRDA_DEBUG(1, "%s(), RECV_RD_RSP\n", __func__);
1585 irlap_flush_all_queues(self);
1586 irlap_next_state(self, LAP_XMIT_P);
1587 /* Call back the LAP state machine to do a proper disconnect */
1588 irlap_disconnect_request(self);
1591 IRDA_DEBUG(1, "%s(), Unknown event %s\n",
1592 __func__, irlap_event[event]);
1601 * Function irlap_state_reset_wait (event, skb, info)
1603 * We have informed the service user of a reset condition, and is
1604 * awaiting reset of disconnect request.
1607 static int irlap_state_reset_wait(struct irlap_cb *self, IRLAP_EVENT event,
1608 struct sk_buff *skb, struct irlap_info *info)
1612 IRDA_DEBUG(3, "%s(), event = %s\n", __func__, irlap_event[event]);
1614 IRDA_ASSERT(self != NULL, return -1;);
1615 IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
1619 if (self->xmitflag) {
1620 irlap_wait_min_turn_around(self, &self->qos_tx);
1621 irlap_send_snrm_frame(self, NULL);
1622 irlap_start_final_timer(self, self->final_timeout);
1623 irlap_next_state(self, LAP_RESET);
1625 irlap_start_final_timer(self, self->final_timeout);
1626 irlap_next_state(self, LAP_RESET);
1629 case DISCONNECT_REQUEST:
1630 irlap_wait_min_turn_around( self, &self->qos_tx);
1631 irlap_send_disc_frame( self);
1632 irlap_flush_all_queues( self);
1633 irlap_start_final_timer( self, self->final_timeout);
1634 self->retry_count = 0;
1635 irlap_next_state( self, LAP_PCLOSE);
1638 IRDA_DEBUG(2, "%s(), Unknown event %s\n", __func__,
1639 irlap_event[event]);
1648 * Function irlap_state_reset (self, event, skb, info)
1650 * We have sent a SNRM reset command to the peer layer, and is awaiting
1654 static int irlap_state_reset(struct irlap_cb *self, IRLAP_EVENT event,
1655 struct sk_buff *skb, struct irlap_info *info)
1659 IRDA_DEBUG(3, "%s(), event = %s\n", __func__, irlap_event[event]);
1661 IRDA_ASSERT(self != NULL, return -1;);
1662 IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
1666 del_timer(&self->final_timer);
1668 irlap_apply_default_connection_parameters(self);
1670 /* Always switch state before calling upper layers */
1671 irlap_next_state(self, LAP_NDM);
1673 irlap_disconnect_indication(self, LAP_NO_RESPONSE);
1677 del_timer(&self->final_timer);
1679 /* Initiate connection state */
1680 irlap_initiate_connection_state(self);
1682 irlap_reset_confirm();
1684 self->remote_busy = FALSE;
1686 irlap_next_state(self, LAP_XMIT_P);
1688 irlap_start_poll_timer(self, self->poll_timeout);
1691 case FINAL_TIMER_EXPIRED:
1692 if (self->retry_count < 3) {
1693 irlap_wait_min_turn_around(self, &self->qos_tx);
1695 IRDA_ASSERT(self->netdev != NULL, return -1;);
1696 irlap_send_snrm_frame(self, self->qos_dev);
1698 self->retry_count++; /* Experimental!! */
1700 irlap_start_final_timer(self, self->final_timeout);
1701 irlap_next_state(self, LAP_RESET);
1702 } else if (self->retry_count >= self->N3) {
1703 irlap_apply_default_connection_parameters(self);
1705 /* Always switch state before calling upper layers */
1706 irlap_next_state(self, LAP_NDM);
1708 irlap_disconnect_indication(self, LAP_NO_RESPONSE);
1713 * SNRM frame is not allowed to contain an I-field in this
1717 IRDA_DEBUG(3, "%s(), RECV_SNRM_CMD\n", __func__);
1718 irlap_initiate_connection_state(self);
1719 irlap_wait_min_turn_around(self, &self->qos_tx);
1720 irlap_send_ua_response_frame(self, &self->qos_rx);
1721 irlap_reset_confirm();
1722 irlap_start_wd_timer(self, self->wd_timeout);
1723 irlap_next_state(self, LAP_NDM);
1726 "%s(), SNRM frame contained an I field!\n",
1731 IRDA_DEBUG(1, "%s(), Unknown event %s\n",
1732 __func__, irlap_event[event]);
1741 * Function irlap_state_xmit_s (event, skb, info)
1743 * XMIT_S, The secondary station has been given the right to transmit,
1744 * and we therefor do not expect to receive any transmissions from other
1747 static int irlap_state_xmit_s(struct irlap_cb *self, IRLAP_EVENT event,
1748 struct sk_buff *skb, struct irlap_info *info)
1752 IRDA_DEBUG(4, "%s(), event=%s\n", __func__, irlap_event[event]);
1754 IRDA_ASSERT(self != NULL, return -ENODEV;);
1755 IRDA_ASSERT(self->magic == LAP_MAGIC, return -EBADR;);
1760 * Send frame only if send window > 0
1762 if ((self->window > 0) && (!self->remote_busy)) {
1764 #ifdef CONFIG_IRDA_DYNAMIC_WINDOW
1765 struct sk_buff *skb_next;
1768 * Same deal as in irlap_state_xmit_p(), so see
1769 * the comments at that point.
1770 * We are the secondary, so there are only subtle
1771 * differences. - Jean II
1774 /* Check if a subsequent skb exist and would fit in
1775 * the current window (with respect to turnaround
1776 * time). - Jean II */
1777 skb_next = skb_peek(&self->txq);
1778 nextfit = ((skb_next != NULL) &&
1779 ((skb_next->len + skb->len) <=
1783 * Test if we have transmitted more bytes over the
1784 * link than its possible to do with the current
1785 * speed and turn-around-time.
1787 if((!nextfit) && (skb->len > self->bytes_left)) {
1788 IRDA_DEBUG(0, "%s(), Not allowed to transmit"
1789 " more bytes!\n", __func__);
1790 /* Requeue the skb */
1791 skb_queue_head(&self->txq, skb_get(skb));
1794 * Switch to NRM_S, this is only possible
1795 * when we are in secondary mode, since we
1796 * must be sure that we don't miss any RR
1799 self->window = self->window_size;
1800 self->bytes_left = self->line_capacity;
1801 irlap_start_wd_timer(self, self->wd_timeout);
1803 irlap_next_state(self, LAP_NRM_S);
1804 /* Slight difference with primary :
1805 * here we would wait for the other side to
1806 * expire the turnaround. - Jean II */
1808 return -EPROTO; /* Try again later */
1810 /* Substract space used by this skb */
1811 self->bytes_left -= skb->len;
1812 #else /* CONFIG_IRDA_DYNAMIC_WINDOW */
1813 /* Window has been adjusted for the max packet
1814 * size, so much simpler... - Jean II */
1815 nextfit = !skb_queue_empty(&self->txq);
1816 #endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
1818 * Send data with final bit cleared only if window > 1
1819 * and there is more frames to be sent
1821 if ((self->window > 1) && (nextfit)) {
1822 irlap_send_data_secondary(self, skb);
1823 irlap_next_state(self, LAP_XMIT_S);
1825 irlap_send_data_secondary_final(self, skb);
1826 irlap_next_state(self, LAP_NRM_S);
1829 * Make sure state machine does not try to send
1835 IRDA_DEBUG(2, "%s(), Unable to send!\n", __func__);
1836 skb_queue_head(&self->txq, skb_get(skb));
1840 case DISCONNECT_REQUEST:
1841 irlap_send_rd_frame(self);
1842 irlap_flush_all_queues(self);
1843 irlap_start_wd_timer(self, self->wd_timeout);
1844 irlap_next_state(self, LAP_SCLOSE);
1847 /* Nothing to do, irlap_do_event() will send the packet
1848 * when we return... - Jean II */
1851 IRDA_DEBUG(2, "%s(), Unknown event %s\n", __func__,
1852 irlap_event[event]);
1861 * Function irlap_state_nrm_s (event, skb, info)
1863 * NRM_S (Normal Response Mode as Secondary) state, in this state we are
1864 * expecting to receive frames from the primary station
1867 static int irlap_state_nrm_s(struct irlap_cb *self, IRLAP_EVENT event,
1868 struct sk_buff *skb, struct irlap_info *info)
1874 IRDA_DEBUG(4, "%s(), event=%s\n", __func__, irlap_event[ event]);
1876 IRDA_ASSERT(self != NULL, return -1;);
1877 IRDA_ASSERT(self->magic == LAP_MAGIC, return -1;);
1880 case RECV_I_CMD: /* Optimize for the common case */
1881 /* FIXME: must check for remote_busy below */
1882 IRDA_DEBUG(4, "%s(), event=%s nr=%d, vs=%d, ns=%d, "
1883 "vr=%d, pf=%d\n", __func__,
1884 irlap_event[event], info->nr,
1885 self->vs, info->ns, self->vr, info->pf);
1887 self->retry_count = 0;
1889 ns_status = irlap_validate_ns_received(self, info->ns);
1890 nr_status = irlap_validate_nr_received(self, info->nr);
1892 * Check for expected I(nformation) frame
1894 if ((ns_status == NS_EXPECTED) && (nr_status == NR_EXPECTED)) {
1896 /* Update Vr (next frame for us to receive) */
1897 self->vr = (self->vr + 1) % 8;
1899 /* Update Nr received */
1900 irlap_update_nr_received(self, info->nr);
1907 self->ack_required = TRUE;
1910 * Starting WD-timer here is optional, but
1911 * not recommended. Note 6 IrLAP p. 83
1914 irda_start_timer(WD_TIMER, self->wd_timeout);
1916 /* Keep state, do not move this line */
1917 irlap_next_state(self, LAP_NRM_S);
1919 irlap_data_indication(self, skb, FALSE);
1923 * We should wait before sending RR, and
1924 * also before changing to XMIT_S
1925 * state. (note 1, IrLAP p. 82)
1927 irlap_wait_min_turn_around(self, &self->qos_tx);
1930 * Give higher layers a chance to
1931 * immediately reply with some data before
1932 * we decide if we should send a RR frame
1935 irlap_data_indication(self, skb, FALSE);
1937 /* Any pending data requests? */
1938 if (!skb_queue_empty(&self->txq) &&
1941 self->ack_required = TRUE;
1943 del_timer(&self->wd_timer);
1945 irlap_next_state(self, LAP_XMIT_S);
1947 irlap_send_rr_frame(self, RSP_FRAME);
1948 irlap_start_wd_timer(self,
1951 /* Keep the state */
1952 irlap_next_state(self, LAP_NRM_S);
1958 * Check for Unexpected next to send (Ns)
1960 if ((ns_status == NS_UNEXPECTED) && (nr_status == NR_EXPECTED))
1962 /* Unexpected next to send, with final bit cleared */
1964 irlap_update_nr_received(self, info->nr);
1966 irlap_start_wd_timer(self, self->wd_timeout);
1968 /* Update Nr received */
1969 irlap_update_nr_received(self, info->nr);
1971 irlap_wait_min_turn_around(self, &self->qos_tx);
1972 irlap_send_rr_frame(self, RSP_FRAME);
1974 irlap_start_wd_timer(self, self->wd_timeout);
1980 * Unexpected Next to Receive(NR) ?
1982 if ((ns_status == NS_EXPECTED) && (nr_status == NR_UNEXPECTED))
1985 IRDA_DEBUG(4, "RECV_I_RSP: frame(s) lost\n");
1987 self->vr = (self->vr + 1) % 8;
1989 /* Update Nr received */
1990 irlap_update_nr_received(self, info->nr);
1992 /* Resend rejected frames */
1993 irlap_resend_rejected_frames(self, RSP_FRAME);
1995 /* Keep state, do not move this line */
1996 irlap_next_state(self, LAP_NRM_S);
1998 irlap_data_indication(self, skb, FALSE);
1999 irlap_start_wd_timer(self, self->wd_timeout);
2003 * This is not documented in IrLAP!! Unexpected NR
2004 * with poll bit cleared
2007 self->vr = (self->vr + 1) % 8;
2009 /* Update Nr received */
2010 irlap_update_nr_received(self, info->nr);
2012 /* Keep state, do not move this line */
2013 irlap_next_state(self, LAP_NRM_S);
2015 irlap_data_indication(self, skb, FALSE);
2016 irlap_start_wd_timer(self, self->wd_timeout);
2021 if (ret == NR_INVALID) {
2022 IRDA_DEBUG(0, "NRM_S, NR_INVALID not implemented!\n");
2024 if (ret == NS_INVALID) {
2025 IRDA_DEBUG(0, "NRM_S, NS_INVALID not implemented!\n");
2033 irlap_data_indication(self, skb, TRUE);
2034 irlap_next_state(self, LAP_NRM_S); /* Keep state */
2037 * Any pending data requests?
2039 if (!skb_queue_empty(&self->txq) &&
2040 (self->window > 0) && !self->remote_busy)
2042 irlap_data_indication(self, skb, TRUE);
2044 del_timer(&self->wd_timer);
2046 irlap_next_state(self, LAP_XMIT_S);
2048 irlap_data_indication(self, skb, TRUE);
2050 irlap_wait_min_turn_around(self, &self->qos_tx);
2052 irlap_send_rr_frame(self, RSP_FRAME);
2053 self->ack_required = FALSE;
2055 irlap_start_wd_timer(self, self->wd_timeout);
2057 /* Keep the state */
2058 irlap_next_state(self, LAP_NRM_S);
2063 self->retry_count = 0;
2068 nr_status = irlap_validate_nr_received(self, info->nr);
2069 if (nr_status == NR_EXPECTED) {
2070 if (!skb_queue_empty(&self->txq) &&
2071 (self->window > 0)) {
2072 self->remote_busy = FALSE;
2074 /* Update Nr received */
2075 irlap_update_nr_received(self, info->nr);
2076 del_timer(&self->wd_timer);
2078 irlap_wait_min_turn_around(self, &self->qos_tx);
2079 irlap_next_state(self, LAP_XMIT_S);
2081 self->remote_busy = FALSE;
2082 /* Update Nr received */
2083 irlap_update_nr_received(self, info->nr);
2084 irlap_wait_min_turn_around(self, &self->qos_tx);
2085 irlap_start_wd_timer(self, self->wd_timeout);
2087 /* Note : if the link is idle (this case),
2088 * we never go in XMIT_S, so we never get a
2089 * chance to process any DISCONNECT_REQUEST.
2090 * Do it now ! - Jean II */
2091 if (self->disconnect_pending) {
2093 irlap_send_rd_frame(self);
2094 irlap_flush_all_queues(self);
2096 irlap_next_state(self, LAP_SCLOSE);
2098 /* Just send back pf bit */
2099 irlap_send_rr_frame(self, RSP_FRAME);
2101 irlap_next_state(self, LAP_NRM_S);
2104 } else if (nr_status == NR_UNEXPECTED) {
2105 self->remote_busy = FALSE;
2106 irlap_update_nr_received(self, info->nr);
2107 irlap_resend_rejected_frames(self, RSP_FRAME);
2109 irlap_start_wd_timer(self, self->wd_timeout);
2112 irlap_next_state(self, LAP_NRM_S);
2114 IRDA_DEBUG(1, "%s(), invalid nr not implemented!\n",
2119 /* SNRM frame is not allowed to contain an I-field */
2121 del_timer(&self->wd_timer);
2122 IRDA_DEBUG(1, "%s(), received SNRM cmd\n", __func__);
2123 irlap_next_state(self, LAP_RESET_CHECK);
2125 irlap_reset_indication(self);
2128 "%s(), SNRM frame contained an I-field!\n",
2134 irlap_update_nr_received(self, info->nr);
2135 if (self->remote_busy) {
2136 irlap_wait_min_turn_around(self, &self->qos_tx);
2137 irlap_send_rr_frame(self, RSP_FRAME);
2139 irlap_resend_rejected_frames(self, RSP_FRAME);
2140 irlap_start_wd_timer(self, self->wd_timeout);
2143 irlap_update_nr_received(self, info->nr);
2144 if (self->remote_busy) {
2145 irlap_wait_min_turn_around(self, &self->qos_tx);
2146 irlap_send_rr_frame(self, RSP_FRAME);
2148 irlap_resend_rejected_frame(self, RSP_FRAME);
2149 irlap_start_wd_timer(self, self->wd_timeout);
2151 case WD_TIMER_EXPIRED:
2153 * Wait until retry_count * n matches negotiated threshold/
2154 * disconnect time (note 2 in IrLAP p. 82)
2156 * Similar to irlap_state_nrm_p() -> FINAL_TIMER_EXPIRED
2157 * Note : self->wd_timeout = (self->final_timeout * 2),
2158 * which explain why we use (self->N2 / 2) here !!!
2161 IRDA_DEBUG(1, "%s(), retry_count = %d\n", __func__,
2164 if (self->retry_count < (self->N2 / 2)) {
2165 /* No retry, just wait for primary */
2166 irlap_start_wd_timer(self, self->wd_timeout);
2167 self->retry_count++;
2169 if((self->retry_count % (self->N1 / 2)) == 0)
2170 irlap_status_indication(self,
2171 STATUS_NO_ACTIVITY);
2173 irlap_apply_default_connection_parameters(self);
2175 /* Always switch state before calling upper layers */
2176 irlap_next_state(self, LAP_NDM);
2177 irlap_disconnect_indication(self, LAP_NO_RESPONSE);
2181 /* Always switch state before calling upper layers */
2182 irlap_next_state(self, LAP_NDM);
2184 /* Send disconnect response */
2185 irlap_wait_min_turn_around(self, &self->qos_tx);
2186 irlap_send_ua_response_frame(self, NULL);
2188 del_timer(&self->wd_timer);
2189 irlap_flush_all_queues(self);
2190 /* Set default link parameters */
2191 irlap_apply_default_connection_parameters(self);
2193 irlap_disconnect_indication(self, LAP_DISC_INDICATION);
2195 case RECV_DISCOVERY_XID_CMD:
2196 irlap_wait_min_turn_around(self, &self->qos_tx);
2197 irlap_send_rr_frame(self, RSP_FRAME);
2198 self->ack_required = TRUE;
2199 irlap_start_wd_timer(self, self->wd_timeout);
2200 irlap_next_state(self, LAP_NRM_S);
2204 /* Remove test frame header (only LAP header in NRM) */
2205 skb_pull(skb, LAP_ADDR_HEADER + LAP_CTRL_HEADER);
2207 irlap_wait_min_turn_around(self, &self->qos_tx);
2208 irlap_start_wd_timer(self, self->wd_timeout);
2210 /* Send response (info will be copied) */
2211 irlap_send_test_frame(self, self->caddr, info->daddr, skb);
2214 IRDA_DEBUG(1, "%s(), Unknown event %d, (%s)\n", __func__,
2215 event, irlap_event[event]);
2224 * Function irlap_state_sclose (self, event, skb, info)
2226 static int irlap_state_sclose(struct irlap_cb *self, IRLAP_EVENT event,
2227 struct sk_buff *skb, struct irlap_info *info)
2231 IRDA_DEBUG(1, "%s()\n", __func__);
2233 IRDA_ASSERT(self != NULL, return -ENODEV;);
2234 IRDA_ASSERT(self->magic == LAP_MAGIC, return -EBADR;);
2238 /* Always switch state before calling upper layers */
2239 irlap_next_state(self, LAP_NDM);
2241 /* Send disconnect response */
2242 irlap_wait_min_turn_around(self, &self->qos_tx);
2243 irlap_send_ua_response_frame(self, NULL);
2245 del_timer(&self->wd_timer);
2246 /* Set default link parameters */
2247 irlap_apply_default_connection_parameters(self);
2249 irlap_disconnect_indication(self, LAP_DISC_INDICATION);
2252 /* IrLAP-1.1 p.82: in SCLOSE, S and I type RSP frames
2253 * shall take us down into default NDM state, like DM_RSP
2260 /* Always switch state before calling upper layers */
2261 irlap_next_state(self, LAP_NDM);
2263 del_timer(&self->wd_timer);
2264 irlap_apply_default_connection_parameters(self);
2266 irlap_disconnect_indication(self, LAP_DISC_INDICATION);
2268 case WD_TIMER_EXPIRED:
2269 /* Always switch state before calling upper layers */
2270 irlap_next_state(self, LAP_NDM);
2272 irlap_apply_default_connection_parameters(self);
2274 irlap_disconnect_indication(self, LAP_DISC_INDICATION);
2277 /* IrLAP-1.1 p.82: in SCLOSE, basically any received frame
2278 * with pf=1 shall restart the wd-timer and resend the rd:rsp
2280 if (info != NULL && info->pf) {
2281 del_timer(&self->wd_timer);
2282 irlap_wait_min_turn_around(self, &self->qos_tx);
2283 irlap_send_rd_frame(self);
2284 irlap_start_wd_timer(self, self->wd_timeout);
2285 break; /* stay in SCLOSE */
2288 IRDA_DEBUG(1, "%s(), Unknown event %d, (%s)\n", __func__,
2289 event, irlap_event[event]);
2298 static int irlap_state_reset_check( struct irlap_cb *self, IRLAP_EVENT event,
2299 struct sk_buff *skb,
2300 struct irlap_info *info)
2304 IRDA_DEBUG(1, "%s(), event=%s\n", __func__, irlap_event[event]);
2306 IRDA_ASSERT(self != NULL, return -ENODEV;);
2307 IRDA_ASSERT(self->magic == LAP_MAGIC, return -EBADR;);
2310 case RESET_RESPONSE:
2311 irlap_send_ua_response_frame(self, &self->qos_rx);
2312 irlap_initiate_connection_state(self);
2313 irlap_start_wd_timer(self, WD_TIMEOUT);
2314 irlap_flush_all_queues(self);
2316 irlap_next_state(self, LAP_NRM_S);
2318 case DISCONNECT_REQUEST:
2319 irlap_wait_min_turn_around(self, &self->qos_tx);
2320 irlap_send_rd_frame(self);
2321 irlap_start_wd_timer(self, WD_TIMEOUT);
2322 irlap_next_state(self, LAP_SCLOSE);
2325 IRDA_DEBUG(1, "%s(), Unknown event %d, (%s)\n", __func__,
2326 event, irlap_event[event]);