aboutsummaryrefslogtreecommitdiffstats
path: root/net/irda/irlap.c
blob: 356e65b1dc42a372c5544edd9d808e534cfc4ee6 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
/*********************************************************************
 *
 * Filename:      irlap.c
 * Version:       1.0
 * Description:   IrLAP implementation for Linux
 * Status:        Stable
 * Author:        Dag Brattli <dagb@cs.uit.no>
 * Created at:    Mon Aug  4 20:40:53 1997
 * Modified at:   Tue Dec 14 09:26:44 1999
 * Modified by:   Dag Brattli <dagb@cs.uit.no>
 *
 *     Copyright (c) 1998-1999 Dag Brattli, All Rights Reserved.
 *     Copyright (c) 2000-2003 Jean Tourrilhes <jt@hpl.hp.com>
 *
 *     This program is free software; you can redistribute it and/or
 *     modify it under the terms of the GNU General Public License as
 *     published by the Free Software Foundation; either version 2 of
 *     the License, or (at your option) any later version.
 *
 *     This program is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 *     GNU General Public License for more details.
 *
 *     You should have received a copy of the GNU General Public License
 *     along with this program; if not, write to the Free Software
 *     Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 *     MA 02111-1307 USA
 *
 ********************************************************************/

#include <linux/slab.h>
#include <linux/string.h>
#include <linux/skbuff.h>
#include <linux/delay.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/random.h>
#include <linux/module.h>
#include <linux/seq_file.h>

#include <net/irda/irda.h>
#include <net/irda/irda_device.h>
#include <net/irda/irqueue.h>
#include <net/irda/irlmp.h>
#include <net/irda/irlmp_frame.h>
#include <net/irda/irlap_frame.h>
#include <net/irda/irlap.h>
#include <net/irda/timer.h>
#include <net/irda/qos.h>

static hashbin_t *irlap = NULL;
int sysctl_slot_timeout = SLOT_TIMEOUT * 1000 / HZ;

/* This is the delay of missed pf period before generating an event
 * to the application. The spec mandate 3 seconds, but in some cases
 * it's way too long. - Jean II */
int sysctl_warn_noreply_time = 3;

extern void irlap_queue_xmit(struct irlap_cb *self, struct sk_buff *skb);
static void __irlap_close(struct irlap_cb *self);
static void irlap_init_qos_capabilities(struct irlap_cb *self,
					struct qos_info *qos_user);

#ifdef CONFIG_IRDA_DEBUG
static const char *const lap_reasons[] = {
	"ERROR, NOT USED",
	"LAP_DISC_INDICATION",
	"LAP_NO_RESPONSE",
	"LAP_RESET_INDICATION",
	"LAP_FOUND_NONE",
	"LAP_MEDIA_BUSY",
	"LAP_PRIMARY_CONFLICT",
	"ERROR, NOT USED",
};
#endif	/* CONFIG_IRDA_DEBUG */

int __init irlap_init(void)
{
	/* Check if the compiler did its job properly.
	 * May happen on some ARM configuration, check with Russell King. */
	IRDA_ASSERT(sizeof(struct xid_frame) == 14, ;);
	IRDA_ASSERT(sizeof(struct test_frame) == 10, ;);
	IRDA_ASSERT(sizeof(struct ua_frame) == 10, ;);
	IRDA_ASSERT(sizeof(struct snrm_frame) == 11, ;);

	/* Allocate master array */
	irlap = hashbin_new(HB_LOCK);
	if (irlap == NULL) {
		IRDA_ERROR("%s: can't allocate irlap hashbin!\n",
			   __func__);
		return -ENOMEM;
	}

	return 0;
}

void irlap_cleanup(void)
{
	IRDA_ASSERT(irlap != NULL, return;);

	hashbin_delete(irlap, (FREE_FUNC) __irlap_close);
}

/*
 * Function irlap_open (driver)
 *
 *    Initialize IrLAP layer
 *
 */
struct irlap_cb *irlap_open(struct net_device *dev, struct qos_info *qos,
			    const char *hw_name)
{
	struct irlap_cb *self;

	IRDA_DEBUG(4, "%s()\n", __func__);

	/* Initialize the irlap structure. */
	self = kzalloc(sizeof(struct irlap_cb), GFP_KERNEL);
	if (self == NULL)
		return NULL;

	self->magic = LAP_MAGIC;

	/* Make a binding between the layers */
	self->netdev = dev;
	self->qos_dev = qos;
	/* Copy hardware name */
	if(hw_name != NULL) {
		strlcpy(self->hw_name, hw_name, sizeof(self->hw_name));
	} else {
		self->hw_name[0] = '\0';
	}

	/* FIXME: should we get our own field? */
	dev->atalk_ptr = self;

	self->state = LAP_OFFLINE;

	/* Initialize transmit queue */
	skb_queue_head_init(&self->txq);
	skb_queue_head_init(&self->txq_ultra);
	skb_queue_head_init(&self->wx_list);

	/* My unique IrLAP device address! */
	/* We don't want the broadcast address, neither the NULL address
	 * (most often used to signify "invalid"), and we don't want an
	 * address already in use (otherwise connect won't be able
	 * to select the proper link). - Jean II */
	do {
		get_random_bytes(&self->saddr, sizeof(self->saddr));
	} while ((self->saddr == 0x0) || (self->saddr == BROADCAST) ||
		 (hashbin_lock_find(irlap, self->saddr, NULL)) );
	/* Copy to the driver */
	memcpy(dev->dev_addr, &self->saddr, 4);

	init_timer(&self->slot_timer);
	init_timer(&self->query_timer);
	init_timer(&self->discovery_timer);
	init_timer(&self->final_timer);
	init_timer(&self->poll_timer);
	init_timer(&self->wd_timer);
	init_timer(&self->backoff_timer);
	init_timer(&self->media_busy_timer);

	irlap_apply_default_connection_parameters(self);

	self->N3 = 3; /* # connections attemts to try before giving up */

	self->state = LAP_NDM;

	hashbin_insert(irlap, (irda_queue_t *) self, self->saddr, NULL);

	irlmp_register_link(self, self->saddr, &self->notify);

	return self;
}
EXPORT_SYMBOL(irlap_open);

/*
 * Function __irlap_close (self)
 *
 *    Remove IrLAP and all allocated memory. Stop any pending timers.
 *
 */
static void __irlap_close(struct irlap_cb *self)
{
	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	/* Stop timers */
	del_timer(&self->slot_timer);
	del_timer(&self->query_timer);
	del_timer(&self->discovery_timer);
	del_timer(&self->final_timer);
	del_timer(&self->poll_timer);
	del_timer(&self->wd_timer);
	del_timer(&self->backoff_timer);
	del_timer(&self->media_busy_timer);

	irlap_flush_all_queues(self);

	self->magic = 0;

	kfree(self);
}

/*
 * Function irlap_close (self)
 *
 *    Remove IrLAP instance
 *
 */
void irlap_close(struct irlap_cb *self)
{
	struct irlap_cb *lap;

	IRDA_DEBUG(4, "%s()\n", __func__);

	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	/* We used to send a LAP_DISC_INDICATION here, but this was
	 * racy. This has been move within irlmp_unregister_link()
	 * itself. Jean II */

	/* Kill the LAP and all LSAPs on top of it */
	irlmp_unregister_link(self->saddr);
	self->notify.instance = NULL;

	/* Be sure that we manage to remove ourself from the hash */
	lap = hashbin_remove(irlap, self->saddr, NULL);
	if (!lap) {
		IRDA_DEBUG(1, "%s(), Didn't find myself!\n", __func__);
		return;
	}
	__irlap_close(lap);
}
EXPORT_SYMBOL(irlap_close);

/*
 * Function irlap_connect_indication (self, skb)
 *
 *    Another device is attempting to make a connection
 *
 */
void irlap_connect_indication(struct irlap_cb *self, struct sk_buff *skb)
{
	IRDA_DEBUG(4, "%s()\n", __func__);

	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	irlap_init_qos_capabilities(self, NULL); /* No user QoS! */

	irlmp_link_connect_indication(self->notify.instance, self->saddr,
				      self->daddr, &self->qos_tx, skb);
}

/*
 * Function irlap_connect_response (self, skb)
 *
 *    Service user has accepted incoming connection
 *
 */
void irlap_connect_response(struct irlap_cb *self, struct sk_buff *userdata)
{
	IRDA_DEBUG(4, "%s()\n", __func__);

	irlap_do_event(self, CONNECT_RESPONSE, userdata, NULL);
}

/*
 * Function irlap_connect_request (self, daddr, qos_user, sniff)
 *
 *    Request connection with another device, sniffing is not implemented
 *    yet.
 *
 */
void irlap_connect_request(struct irlap_cb *self, __u32 daddr,
			   struct qos_info *qos_user, int sniff)
{
	IRDA_DEBUG(3, "%s(), daddr=0x%08x\n", __func__, daddr);

	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	self->daddr = daddr;

	/*
	 *  If the service user specifies QoS values for this connection,
	 *  then use them
	 */
	irlap_init_qos_capabilities(self, qos_user);

	if ((self->state == LAP_NDM) && !self->media_busy)
		irlap_do_event(self, CONNECT_REQUEST, NULL, NULL);
	else
		self->connect_pending = TRUE;
}

/*
 * Function irlap_connect_confirm (self, skb)
 *
 *    Connection request has been accepted
 *
 */
void irlap_connect_confirm(struct irlap_cb *self, struct sk_buff *skb)
{
	IRDA_DEBUG(4, "%s()\n", __func__);

	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	irlmp_link_connect_confirm(self->notify.instance, &self->qos_tx, skb);
}

/*
 * Function irlap_data_indication (self, skb)
 *
 *    Received data frames from IR-port, so we just pass them up to
 *    IrLMP for further processing
 *
 */
void irlap_data_indication(struct irlap_cb *self, struct sk_buff *skb,
			   int unreliable)
{
	/* Hide LAP header from IrLMP layer */
	skb_pull(skb, LAP_ADDR_HEADER+LAP_CTRL_HEADER);

	irlmp_link_data_indication(self->notify.instance, skb, unreliable);
}


/*
 * Function irlap_data_request (self, skb)
 *
 *    Queue data for transmission, must wait until XMIT state
 *
 */
void irlap_data_request(struct irlap_cb *self, struct sk_buff *skb,
			int unreliable)
{
	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	IRDA_DEBUG(3, "%s()\n", __func__);

	IRDA_ASSERT(skb_headroom(skb) >= (LAP_ADDR_HEADER+LAP_CTRL_HEADER),
		    return;);
	skb_push(skb, LAP_ADDR_HEADER+LAP_CTRL_HEADER);

	/*
	 *  Must set frame format now so that the rest of the code knows
	 *  if its dealing with an I or an UI frame
	 */
	if (unreliable)
		skb->data[1] = UI_FRAME;
	else
		skb->data[1] = I_FRAME;

	/* Don't forget to refcount it - see irlmp_connect_request(). */
	skb_get(skb);

	/* Add at the end of the queue (keep ordering) - Jean II */
	skb_queue_tail(&self->txq, skb);

	/*
	 *  Send event if this frame only if we are in the right state
	 *  FIXME: udata should be sent first! (skb_queue_head?)
	 */
	if ((self->state == LAP_XMIT_P) || (self->state == LAP_XMIT_S)) {
		/* If we are not already processing the Tx queue, trigger
		 * transmission immediately - Jean II */
		if((skb_queue_len(&self->txq) <= 1) && (!self->local_busy))
			irlap_do_event(self, DATA_REQUEST, skb, NULL);
		/* Otherwise, the packets will be sent normally at the
		 * next pf-poll - Jean II */
	}
}

/*
 * Function irlap_unitdata_request (self, skb)
 *
 *    Send Ultra data. This is data that must be sent outside any connection
 *
 */
#ifdef CONFIG_IRDA_ULTRA
void irlap_unitdata_request(struct irlap_cb *self, struct sk_buff *skb)
{
	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	IRDA_DEBUG(3, "%s()\n", __func__);

	IRDA_ASSERT(skb_headroom(skb) >= (LAP_ADDR_HEADER+LAP_CTRL_HEADER),
	       return;);
	skb_push(skb, LAP_ADDR_HEADER+LAP_CTRL_HEADER);

	skb->data[0] = CBROADCAST;
	skb->data[1] = UI_FRAME;

	/* Don't need to refcount, see irlmp_connless_data_request() */

	skb_queue_tail(&self->txq_ultra, skb);

	irlap_do_event(self, SEND_UI_FRAME, NULL, NULL);
}
#endif /*CONFIG_IRDA_ULTRA */

/*
 * Function irlap_udata_indication (self, skb)
 *
 *    Receive Ultra data. This is data that is received outside any connection
 *
 */
#ifdef CONFIG_IRDA_ULTRA
void irlap_unitdata_indication(struct irlap_cb *self, struct sk_buff *skb)
{
	IRDA_DEBUG(1, "%s()\n", __func__);

	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
	IRDA_ASSERT(skb != NULL, return;);

	/* Hide LAP header from IrLMP layer */
	skb_pull(skb, LAP_ADDR_HEADER+LAP_CTRL_HEADER);

	irlmp_link_unitdata_indication(self->notify.instance, skb);
}
#endif /* CONFIG_IRDA_ULTRA */

/*
 * Function irlap_disconnect_request (void)
 *
 *    Request to disconnect connection by service user
 */
void irlap_disconnect_request(struct irlap_cb *self)
{
	IRDA_DEBUG(3, "%s()\n", __func__);

	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	/* Don't disconnect until all data frames are successfully sent */
	if (!skb_queue_empty(&self->txq)) {
		self->disconnect_pending = TRUE;
		return;
	}

	/* Check if we are in the right state for disconnecting */
	switch (self->state) {
	case LAP_XMIT_P:        /* FALLTROUGH */
	case LAP_XMIT_S:        /* FALLTROUGH */
	case LAP_CONN:          /* FALLTROUGH */
	case LAP_RESET_WAIT:    /* FALLTROUGH */
	case LAP_RESET_CHECK:
		irlap_do_event(self, DISCONNECT_REQUEST, NULL, NULL);
		break;
	default:
		IRDA_DEBUG(2, "%s(), disconnect pending!\n", __func__);
		self->disconnect_pending = TRUE;
		break;
	}
}

/*
 * Function irlap_disconnect_indication (void)
 *
 *    Disconnect request from other device
 *
 */
void irlap_disconnect_indication(struct irlap_cb *self, LAP_REASON reason)
{
	IRDA_DEBUG(1, "%s(), reason=%s\n", __func__, lap_reasons[reason]);

	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	/* Flush queues */
	irlap_flush_all_queues(self);

	switch (reason) {
	case LAP_RESET_INDICATION:
		IRDA_DEBUG(1, "%s(), Sending reset request!\n", __func__);
		irlap_do_event(self, RESET_REQUEST, NULL, NULL);
		break;
	case LAP_NO_RESPONSE:	   /* FALLTROUGH */
	case LAP_DISC_INDICATION:  /* FALLTROUGH */
	case LAP_FOUND_NONE:       /* FALLTROUGH */
	case LAP_MEDIA_BUSY:
		irlmp_link_disconnect_indication(self->notify.instance, self,
						 reason, NULL);
		break;
	default:
		IRDA_ERROR("%s: Unknown reason %d\n", __func__, reason);
	}
}

/*
 * Function irlap_discovery_request (gen_addr_bit)
 *
 *    Start one single discovery operation.
 *
 */
void irlap_discovery_request(struct irlap_cb *self, discovery_t *discovery)
{
	struct irlap_info info;

	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
	IRDA_ASSERT(discovery != NULL, return;);

	IRDA_DEBUG(4, "%s(), nslots = %d\n", __func__, discovery->nslots);

	IRDA_ASSERT((discovery->nslots == 1) || (discovery->nslots == 6) ||
		    (discovery->nslots == 8) || (discovery->nslots == 16),
		    return;);

	/* Discovery is only possible in NDM mode */
	if (self->state != LAP_NDM) {
		IRDA_DEBUG(4, "%s(), discovery only possible in NDM mode\n",
			   __func__);
		irlap_discovery_confirm(self, NULL);
		/* Note : in theory, if we are not in NDM, we could postpone
		 * the discovery like we do for connection request.
		 * In practice, it's not worth it. If the media was busy,
		 * it's likely next time around it won't be busy. If we are
		 * in REPLY state, we will get passive discovery info & event.
		 * Jean II */
		return;
	}

	/* Check if last discovery request finished in time, or if
	 * it was aborted due to the media busy flag. */
	if (self->discovery_log != NULL) {
		hashbin_delete(self->discovery_log, (FREE_FUNC) kfree);
		self->discovery_log = NULL;
	}

	/* All operations will occur at predictable time, no need to lock */
	self->discovery_log = hashbin_new(HB_NOLOCK);

	if (self->discovery_log == NULL) {
		IRDA_WARNING("%s(), Unable to allocate discovery log!\n",
			     __func__);
		return;
	}

	info.S = discovery->nslots; /* Number of slots */
	info.s = 0; /* Current slot */

	self->discovery_cmd = discovery;
	info.discovery = discovery;

	/* sysctl_slot_timeout bounds are checked in irsysctl.c - Jean II */
	self->slot_timeout = sysctl_slot_timeout * HZ / 1000;

	irlap_do_event(self, DISCOVERY_REQUEST, NULL, &info);
}

/*
 * Function irlap_discovery_confirm (log)
 *
 *    A device has been discovered in front of this station, we
 *    report directly to LMP.
 */
void irlap_discovery_confirm(struct irlap_cb *self, hashbin_t *discovery_log)
{
	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	IRDA_ASSERT(self->notify.instance != NULL, return;);

	/*
	 * Check for successful discovery, since we are then allowed to clear
	 * the media busy condition (IrLAP 6.13.4 - p.94). This should allow
	 * us to make connection attempts much faster and easier (i.e. no
	 * collisions).
	 * Setting media busy to false will also generate an event allowing
	 * to process pending events in NDM state machine.
	 * Note : the spec doesn't define what's a successful discovery is.
	 * If we want Ultra to work, it's successful even if there is
	 * nobody discovered - Jean II
	 */
	if (discovery_log)
		irda_device_set_media_busy(self->netdev, FALSE);

	/* Inform IrLMP */
	irlmp_link_discovery_confirm(self->notify.instance, discovery_log);
}

/*
 * Function irlap_discovery_indication (log)
 *
 *    Somebody is trying to discover us!
 *
 */
void irlap_discovery_indication(struct irlap_cb *self, discovery_t *discovery)
{
	IRDA_DEBUG(4, "%s()\n", __func__);

	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
	IRDA_ASSERT(discovery != NULL, return;);

	IRDA_ASSERT(self->notify.instance != NULL, return;);

	/* A device is very likely to connect immediately after it performs
	 * a successful discovery. This means that in our case, we are much
	 * more likely to receive a connection request over the medium.
	 * So, we backoff to avoid collisions.
	 * IrLAP spec 6.13.4 suggest 100ms...
	 * Note : this little trick actually make a *BIG* difference. If I set
	 * my Linux box with discovery enabled and one Ultra frame sent every
	 * second, my Palm has no trouble connecting to it every time !
	 * Jean II */
	irda_device_set_media_busy(self->netdev, SMALL);

	irlmp_link_discovery_indication(self->notify.instance, discovery);
}

/*
 * Function irlap_status_indication (quality_of_link)
 */
void irlap_status_indication(struct irlap_cb *self, int quality_of_link)
{
	switch (quality_of_link) {
	case STATUS_NO_ACTIVITY:
		IRDA_MESSAGE("IrLAP, no activity on link!\n");
		break;
	case STATUS_NOISY:
		IRDA_MESSAGE("IrLAP, noisy link!\n");
		break;
	default:
		break;
	}
	irlmp_status_indication(self->notify.instance,
				quality_of_link, LOCK_NO_CHANGE);
}

/*
 * Function irlap_reset_indication (void)
 */
void irlap_reset_indication(struct irlap_cb *self)
{
	IRDA_DEBUG(1, "%s()\n", __func__);

	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	if (self->state == LAP_RESET_WAIT)
		irlap_do_event(self, RESET_REQUEST, NULL, NULL);
	else
		irlap_do_event(self, RESET_RESPONSE, NULL, NULL);
}

/*
 * Function irlap_reset_confirm (void)
 */
void irlap_reset_confirm(void)
{
	IRDA_DEBUG(1, "%s()\n", __func__);
}

/*
 * Function irlap_generate_rand_time_slot (S, s)
 *
 *    Generate a random time slot between s and S-1 where
 *    S = Number of slots (0 -> S-1)
 *    s = Current slot
 */
int irlap_generate_rand_time_slot(int S, int s)
{
	static int rand;
	int slot;

	IRDA_ASSERT((S - s) > 0, return 0;);

	rand += jiffies;
	rand ^= (rand << 12);
	rand ^= (rand >> 20);

	slot = s + rand % (S-s);

	IRDA_ASSERT((slot >= s) || (slot < S), return 0;);

	return slot;
}

/*
 * Function irlap_update_nr_received (nr)
 *
 *    Remove all acknowledged frames in current window queue. This code is
 *    not intuitive and you should not try to change it. If you think it
 *    contains bugs, please mail a patch to the author instead.
 */
void irlap_update_nr_received(struct irlap_cb *self, int nr)
{
	struct sk_buff *skb = NULL;
	int count = 0;

	/*
	 * Remove all the ack-ed frames from the window queue.
	 */

	/*
	 *  Optimize for the common case. It is most likely that the receiver
	 *  will acknowledge all the frames we have sent! So in that case we
	 *  delete all frames stored in window.
	 */
	if (nr == self->vs) {
		while ((skb = skb_dequeue(&self->wx_list)) != NULL) {
			dev_kfree_skb(skb);
		}
		/* The last acked frame is the next to send minus one */
		self->va = nr - 1;
	} else {
		/* Remove all acknowledged frames in current window */
		while ((skb_peek(&self->wx_list) != NULL) &&
		       (((self->va+1) % 8) != nr))
		{
			skb = skb_dequeue(&self->wx_list);
			dev_kfree_skb(skb);

			self->va = (self->va + 1) % 8;
			count++;
		}
	}

	/* Advance window */
	self->window = self->window_size - skb_queue_len(&self->wx_list);
}

/*
 * Function irlap_validate_ns_received (ns)
 *
 *    Validate the next to send (ns) field from received frame.
 */
int irlap_validate_ns_received(struct irlap_cb *self, int ns)
{
	/*  ns as expected?  */
	if (ns == self->vr)
		return NS_EXPECTED;
	/*
	 *  Stations are allowed to treat invalid NS as unexpected NS
	 *  IrLAP, Recv ... with-invalid-Ns. p. 84
	 */
	return NS_UNEXPECTED;

	/* return NR_INVALID; */
}
/*
 * Function irlap_validate_nr_received (nr)
 *
 *    Validate the next to receive (nr) field from received frame.
 *
 */
int irlap_validate_nr_received(struct irlap_cb *self, int nr)
{
	/*  nr as expected?  */
	if (nr == self->vs) {
		IRDA_DEBUG(4, "%s(), expected!\n", __func__);
		return NR_EXPECTED;
	}

	/*
	 *  unexpected nr? (but within current window), first we check if the
	 *  ns numbers of the frames in the current window wrap.
	 */
	if (self->va < self->vs) {
		if ((nr >= self->va) && (nr <= self->vs))
			return NR_UNEXPECTED;
	} else {
		if ((nr >= self->va) || (nr <= self->vs))
			return NR_UNEXPECTED;
	}

	/* Invalid nr!  */
	return NR_INVALID;
}

/*
 * Function irlap_initiate_connection_state ()
 *
 *    Initialize the connection state parameters
 *
 */
void irlap_initiate_connection_state(struct irlap_cb *self)
{
	IRDA_DEBUG(4, "%s()\n", __func__);

	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	/* Next to send and next to receive */
	self->vs = self->vr = 0;

	/* Last frame which got acked (0 - 1) % 8 */
	self->va = 7;

	self->window = 1;

	self->remote_busy = FALSE;
	self->retry_count = 0;
}

/*
 * Function irlap_wait_min_turn_around (self, qos)
 *
 *    Wait negotiated minimum turn around time, this function actually sets
 *    the number of BOS's that must be sent before the next transmitted
 *    frame in order to delay for the specified amount of time. This is
 *    done to avoid using timers, and the forbidden udelay!
 */
void irlap_wait_min_turn_around(struct irlap_cb *self, struct qos_info *qos)
{
	__u32 min_turn_time;
	__u32 speed;

	/* Get QoS values.  */
	speed = qos->baud_rate.value;
	min_turn_time = qos->min_turn_time.value;

	/* No need to calculate XBOFs for speeds over 115200 bps */
	if (speed > 115200) {
		self->mtt_required = min_turn_time;
		return;
	}

	/*
	 *  Send additional BOF's for the next frame for the requested
	 *  min turn time, so now we must calculate how many chars (XBOF's) we
	 *  must send for the requested time period (min turn time)
	 */
	self->xbofs_delay = irlap_min_turn_time_in_bytes(speed, min_turn_time);
}

/*
 * Function irlap_flush_all_queues (void)
 *
 *    Flush all queues
 *
 */
void irlap_flush_all_queues(struct irlap_cb *self)
{
	struct sk_buff* skb;

	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	/* Free transmission queue */
	while ((skb = skb_dequeue(&self->txq)) != NULL)
		dev_kfree_skb(skb);

	while ((skb = skb_dequeue(&self->txq_ultra)) != NULL)
		dev_kfree_skb(skb);

	/* Free sliding window buffered packets */
	while ((skb = skb_dequeue(&self->wx_list)) != NULL)
		dev_kfree_skb(skb);
}

/*
 * Function irlap_setspeed (self, speed)
 *
 *    Change the speed of the IrDA port
 *
 */
static void irlap_change_speed(struct irlap_cb *self, __u32 speed, int now)
{
	struct sk_buff *skb;

	IRDA_DEBUG(0, "%s(), setting speed to %d\n", __func__, speed);

	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	self->speed = speed;

	/* Change speed now, or just piggyback speed on frames */
	if (now) {
		/* Send down empty frame to trigger speed change */
		skb = alloc_skb(0, GFP_ATOMIC);
		if (skb)
			irlap_queue_xmit(self, skb);
	}
}

/*
 * Function irlap_init_qos_capabilities (self, qos)
 *
 *    Initialize QoS for this IrLAP session, What we do is to compute the
 *    intersection of the QoS capabilities for the user, driver and for
 *    IrLAP itself. Normally, IrLAP will not specify any values, but it can
 *    be used to restrict certain values.
 */
static void irlap_init_qos_capabilities(struct irlap_cb *self,
					struct qos_info *qos_user)
{
	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
	IRDA_ASSERT(self->netdev != NULL, return;);

	/* Start out with the maximum QoS support possible */
	irda_init_max_qos_capabilies(&self->qos_rx);

	/* Apply drivers QoS capabilities */
	irda_qos_compute_intersection(&self->qos_rx, self->qos_dev);

	/*
	 *  Check for user supplied QoS parameters. The service user is only
	 *  allowed to supply these values. We check each parameter since the
	 *  user may not have set all of them.
	 */
	if (qos_user) {
		IRDA_DEBUG(1, "%s(), Found user specified QoS!\n", __func__);

		if (qos_user->baud_rate.bits)
			self->qos_rx.baud_rate.bits &= qos_user->baud_rate.bits;

		if (qos_user->max_turn_time.bits)
			self->qos_rx.max_turn_time.bits &= qos_user->max_turn_time.bits;
		if (qos_user->data_size.bits)
			self->qos_rx.data_size.bits &= qos_user->data_size.bits;

		if (qos_user->link_disc_time.bits)
			self->qos_rx.link_disc_time.bits &= qos_user->link_disc_time.bits;
	}

	/* Use 500ms in IrLAP for now */
	self->qos_rx.max_turn_time.bits &= 0x01;

	/* Set data size */
	/*self->qos_rx.data_size.bits &= 0x03;*/

	irda_qos_bits_to_value(&self->qos_rx);
}

/*
 * Function irlap_apply_default_connection_parameters (void, now)
 *
 *    Use the default connection and transmission parameters
 */
void irlap_apply_default_connection_parameters(struct irlap_cb *self)
{
	IRDA_DEBUG(4, "%s()\n", __func__);

	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	/* xbofs : Default value in NDM */
	self->next_bofs   = 12;
	self->bofs_count  = 12;

	/* NDM Speed is 9600 */
	irlap_change_speed(self, 9600, TRUE);

	/* Set mbusy when going to NDM state */
	irda_device_set_media_busy(self->netdev, TRUE);

	/*
	 * Generate random connection address for this session, which must
	 * be 7 bits wide and different from 0x00 and 0xfe
	 */
	while ((self->caddr == 0x00) || (self->caddr == 0xfe)) {
		get_random_bytes(&self->caddr, sizeof(self->caddr));
		self->caddr &= 0xfe;
	}

	/* Use default values until connection has been negitiated */
	self->slot_timeout = sysctl_slot_timeout;
	self->final_timeout = FINAL_TIMEOUT;
	self->poll_timeout = POLL_TIMEOUT;
	self->wd_timeout = WD_TIMEOUT;

	/* Set some default values */
	self->qos_tx.baud_rate.value = 9600;
	self->qos_rx.baud_rate.value = 9600;
	self->qos_tx.max_turn_time.value = 0;
	self->qos_rx.max_turn_time.value = 0;
	self->qos_tx.min_turn_time.value = 0;
	self->qos_rx.min_turn_time.value = 0;
	self->qos_tx.data_size.value = 64;
	self->qos_rx.data_size.value = 64;
	self->qos_tx.window_size.value = 1;
	self->qos_rx.window_size.value = 1;
	self->qos_tx.additional_bofs.value = 12;
	self->qos_rx.additional_bofs.value = 12;
	self->qos_tx.link_disc_time.value = 0;
	self->qos_rx.link_disc_time.value = 0;

	irlap_flush_all_queues(self);

	self->disconnect_pending = FALSE;
	self->connect_pending = FALSE;
}

/*
 * Function irlap_apply_connection_parameters (qos, now)
 *
 *    Initialize IrLAP with the negotiated QoS values
 *
 * If 'now' is false, the speed and xbofs will be changed after the next
 * frame is sent.
 * If 'now' is true, the speed and xbofs is changed immediately
 */
void irlap_apply_connection_parameters(struct irlap_cb *self, int now)
{
	IRDA_DEBUG(4, "%s()\n", __func__);

	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	/* Set the negotiated xbofs value */
	self->next_bofs   = self->qos_tx.additional_bofs.value;
	if (now)
		self->bofs_count = self->next_bofs;

	/* Set the negotiated link speed (may need the new xbofs value) */
	irlap_change_speed(self, self->qos_tx.baud_rate.value, now);

	self->window_size = self->qos_tx.window_size.value;
	self->window      = self->qos_tx.window_size.value;

#ifdef CONFIG_IRDA_DYNAMIC_WINDOW
	/*
	 *  Calculate how many bytes it is possible to transmit before the
	 *  link must be turned around
	 */
	self->line_capacity =
		irlap_max_line_capacity(self->qos_tx.baud_rate.value,
					self->qos_tx.max_turn_time.value);
	self->bytes_left = self->line_capacity;
#endif /* CONFIG_IRDA_DYNAMIC_WINDOW */


	/*
	 *  Initialize timeout values, some of the rules are listed on
	 *  page 92 in IrLAP.
	 */
	IRDA_ASSERT(self->qos_tx.max_turn_time.value != 0, return;);
	IRDA_ASSERT(self->qos_rx.max_turn_time.value != 0, return;);
	/* The poll timeout applies only to the primary station.
	 * It defines the maximum time the primary stay in XMIT mode
	 * before timeout and turning the link around (sending a RR).
	 * Or, this is how much we can keep the pf bit in primary mode.
	 * Therefore, it must be lower or equal than our *OWN* max turn around.
	 * Jean II */
	self->poll_timeout = self->qos_tx.max_turn_time.value * HZ / 1000;
	/* The Final timeout applies only to the primary station.
	 * It defines the maximum time the primary wait (mostly in RECV mode)
	 * for an answer from the secondary station before polling it again.
	 * Therefore, it must be greater or equal than our *PARTNER*
	 * max turn around time - Jean II */
	self->final_timeout = self->qos_rx.max_turn_time.value * HZ / 1000;
	/* The Watchdog Bit timeout applies only to the secondary station.
	 * It defines the maximum time the secondary wait (mostly in RECV mode)
	 * for poll from the primary station before getting annoyed.
	 * Therefore, it must be greater or equal than our *PARTNER*
	 * max turn around time - Jean II */
	self->wd_timeout = self->final_timeout * 2;

	/*
	 * N1 and N2 are maximum retry count for *both* the final timer
	 * and the wd timer (with a factor 2) as defined above.
	 * After N1 retry of a timer, we give a warning to the user.
	 * After N2 retry, we consider the link dead and disconnect it.
	 * Jean II
	 */

	/*
	 *  Set N1 to 0 if Link Disconnect/Threshold Time = 3 and set it to
	 *  3 seconds otherwise. See page 71 in IrLAP for more details.
	 *  Actually, it's not always 3 seconds, as we allow to set
	 *  it via sysctl... Max maxtt is 500ms, and N1 need to be multiple
	 *  of 2, so 1 second is minimum we can allow. - Jean II
	 */
	if (self->qos_tx.link_disc_time.value == sysctl_warn_noreply_time)
		/*
		 * If we set N1 to 0, it will trigger immediately, which is
		 * not what we want. What we really want is to disable it,
		 * Jean II
		 */
		self->N1 = -2; /* Disable - Need to be multiple of 2*/
	else
		self->N1 = sysctl_warn_noreply_time * 1000 /
		  self->qos_rx.max_turn_time.value;

	IRDA_DEBUG(4, "Setting N1 = %d\n", self->N1);

	/* Set N2 to match our own disconnect time */
	self->N2 = self->qos_tx.link_disc_time.value * 1000 /
		self->qos_rx.max_turn_time.value;
	IRDA_DEBUG(4, "Setting N2 = %d\n", self->N2);
}

#ifdef CONFIG_PROC_FS
struct irlap_iter_state {
	int id;
};

static void *irlap_seq_start(struct seq_file *seq, loff_t *pos)
{
	struct irlap_iter_state *iter = seq->private;
	struct irlap_cb *self;

	/* Protect our access to the tsap list */
	spin_lock_irq(&irlap->hb_spinlock);
	iter->id = 0;

	for (self = (struct irlap_cb *) hashbin_get_first(irlap);
	     self; self = (struct irlap_cb *) hashbin_get_next(irlap)) {
		if (iter->id == *pos)
			break;
		++iter->id;
	}

	return self;
}

static void *irlap_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	struct irlap_iter_state *iter = seq->private;

	++*pos;
	++iter->id;
	return (void *) hashbin_get_next(irlap);
}

static void irlap_seq_stop(struct seq_file *seq, void *v)
{
	spin_unlock_irq(&irlap->hb_spinlock);
}

static int irlap_seq_show(struct seq_file *seq, void *v)
{
	const struct irlap_iter_state *iter = seq->private;
	const struct irlap_cb *self = v;

	IRDA_ASSERT(self->magic == LAP_MAGIC, return -EINVAL;);

	seq_printf(seq, "irlap%d ", iter->id);
	seq_printf(seq, "state: %s\n",
		   irlap_state[self->state]);

	seq_printf(seq, "  device name: %s, ",
		   (self->netdev) ? self->netdev->name : "bug");
	seq_printf(seq, "hardware name: %s\n", self->hw_name);

	seq_printf(seq, "  caddr: %#02x, ", self->caddr);
	seq_printf(seq, "saddr: %#08x, ", self->saddr);
	seq_printf(seq, "daddr: %#08x\n", self->daddr);

	seq_printf(seq, "  win size: %d, ",
		   self->window_size);
	seq_printf(seq, "win: %d, ", self->window);
#ifdef CONFIG_IRDA_DYNAMIC_WINDOW
	seq_printf(seq, "line capacity: %d, ",
		   self->line_capacity);
	seq_printf(seq, "bytes left: %d\n", self->bytes_left);
#endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
	seq_printf(seq, "  tx queue len: %d ",
		   skb_queue_len(&self->txq));
	seq_printf(seq, "win queue len: %d ",
		   skb_queue_len(&self->wx_list));
	seq_printf(seq, "rbusy: %s", self->remote_busy ?
		   "TRUE" : "FALSE");
	seq_printf(seq, " mbusy: %s\n", self->media_busy ?
		   "TRUE" : "FALSE");

	seq_printf(seq, "  retrans: %d ", self->retry_count);
	seq_printf(seq, "vs: %d ", self->vs);
	seq_printf(seq, "vr: %d ", self->vr);
	seq_printf(seq, "va: %d\n", self->va);

	seq_printf(seq, "  qos\tbps\tmaxtt\tdsize\twinsize\taddbofs\tmintt\tldisc\tcomp\n");

	seq_printf(seq, "  tx\t%d\t",
		   self->qos_tx.baud_rate.value);
	seq_printf(seq, "%d\t",
		   self->qos_tx.max_turn_time.value);
	seq_printf(seq, "%d\t",
		   self->qos_tx.data_size.value);
	seq_printf(seq, "%d\t",
		   self->qos_tx.window_size.value);
	seq_printf(seq, "%d\t",
		   self->qos_tx.additional_bofs.value);
	seq_printf(seq, "%d\t",
		   self->qos_tx.min_turn_time.value);
	seq_printf(seq, "%d\t",
		   self->qos_tx.link_disc_time.value);
	seq_printf(seq, "\n");

	seq_printf(seq, "  rx\t%d\t",
		   self->qos_rx.baud_rate.value);
	seq_printf(seq, "%d\t",
		   self->qos_rx.max_turn_time.value);
	seq_printf(seq, "%d\t",
		   self->qos_rx.data_size.value);
	seq_printf(seq, "%d\t",
		   self->qos_rx.window_size.value);
	seq_printf(seq, "%d\t",
		   self->qos_rx.additional_bofs.value);
	seq_printf(seq, "%d\t",
		   self->qos_rx.min_turn_time.value);
	seq_printf(seq, "%d\n",
		   self->qos_rx.link_disc_time.value);

	return 0;
}

static const struct seq_operations irlap_seq_ops = {
	.start  = irlap_seq_start,
	.next   = irlap_seq_next,
	.stop   = irlap_seq_stop,
	.show   = irlap_seq_show,
};

static int irlap_seq_open(struct inode *inode, struct file *file)
{
	if (irlap == NULL)
		return -EINVAL;

	return seq_open_private(file, &irlap_seq_ops,
			sizeof(struct irlap_iter_state));
}

const struct file_operations irlap_seq_fops = {
	.owner		= THIS_MODULE,
	.open           = irlap_seq_open,
	.read           = seq_read,
	.llseek         = seq_lseek,
	.release	= seq_release_private,
};

#endif /* CONFIG_PROC_FS */