summaryrefslogtreecommitdiffstats
path: root/sys/net80211/ieee80211_tdma.c
blob: 278decf97b9a42f7f33533316c1e8b3c8efadad1 (plain)
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
/*-
 * Copyright (c) 2007-2009 Sam Leffler, Errno Consulting
 * Copyright (c) 2007-2009 Intel Corporation
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#ifdef __FreeBSD__
__FBSDID("$FreeBSD$");
#endif

/*
 * IEEE 802.11 TDMA mode support.
 */
#include "opt_inet.h"
#include "opt_tdma.h"
#include "opt_wlan.h"

#ifdef	IEEE80211_SUPPORT_TDMA

#include <sys/param.h>
#include <sys/systm.h> 
#include <sys/mbuf.h>   
#include <sys/malloc.h>
#include <sys/kernel.h>

#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/endian.h>
#include <sys/errno.h>
#include <sys/proc.h>
#include <sys/sysctl.h>

#include <net/if.h>
#include <net/if_media.h>
#include <net/if_llc.h>
#include <net/ethernet.h>

#include <net/bpf.h>

#include <net80211/ieee80211_var.h>
#include <net80211/ieee80211_tdma.h>
#include <net80211/ieee80211_input.h>

#ifndef TDMA_SLOTLEN_DEFAULT
#define	TDMA_SLOTLEN_DEFAULT	10*1000		/* 10ms */
#endif
#ifndef TDMA_SLOTCNT_DEFAULT
#define	TDMA_SLOTCNT_DEFAULT	2		/* 2x (pt-to-pt) */
#endif
#ifndef TDMA_BINTVAL_DEFAULT
#define	TDMA_BINTVAL_DEFAULT	5		/* 5x ~= 100TU beacon intvl */
#endif
#ifndef TDMA_TXRATE_11B_DEFAULT
#define	TDMA_TXRATE_11B_DEFAULT	2*11
#endif
#ifndef TDMA_TXRATE_11G_DEFAULT
#define	TDMA_TXRATE_11G_DEFAULT	2*24
#endif
#ifndef TDMA_TXRATE_11A_DEFAULT
#define	TDMA_TXRATE_11A_DEFAULT	2*24
#endif
#ifndef TDMA_TXRATE_TURBO_DEFAULT
#define	TDMA_TXRATE_TURBO_DEFAULT	2*24
#endif
#ifndef TDMA_TXRATE_HALF_DEFAULT
#define	TDMA_TXRATE_HALF_DEFAULT	2*12
#endif
#ifndef TDMA_TXRATE_QUARTER_DEFAULT
#define	TDMA_TXRATE_QUARTER_DEFAULT	2*6
#endif
#ifndef TDMA_TXRATE_11NA_DEFAULT
#define	TDMA_TXRATE_11NA_DEFAULT	(4 | IEEE80211_RATE_MCS)
#endif
#ifndef TDMA_TXRATE_11NG_DEFAULT
#define	TDMA_TXRATE_11NG_DEFAULT	(4 | IEEE80211_RATE_MCS)
#endif

#define	TDMA_VERSION_VALID(_version) \
	(TDMA_VERSION_V2 <= (_version) && (_version) <= TDMA_VERSION)
#define	TDMA_SLOTCNT_VALID(_slotcnt) \
	(2 <= (_slotcnt) && (_slotcnt) <= TDMA_MAXSLOTS)
/* XXX magic constants */
#define	TDMA_SLOTLEN_VALID(_slotlen) \
	(2*100 <= (_slotlen) && (unsigned)(_slotlen) <= 0xfffff)
/* XXX probably should set a max */
#define	TDMA_BINTVAL_VALID(_bintval)	(1 <= (_bintval))

/*
 * This code is not prepared to handle more than 2 slots.
 */
CTASSERT(TDMA_MAXSLOTS == 2);

static void tdma_vdetach(struct ieee80211vap *vap);
static int tdma_newstate(struct ieee80211vap *, enum ieee80211_state, int);
static void tdma_beacon_miss(struct ieee80211vap *vap);
static void tdma_recv_mgmt(struct ieee80211_node *, struct mbuf *,
	int subtype, const struct ieee80211_rx_stats *rxs, int rssi, int nf);
static int tdma_update(struct ieee80211vap *vap,
	const struct ieee80211_tdma_param *tdma, struct ieee80211_node *ni,
	int pickslot);
static int tdma_process_params(struct ieee80211_node *ni,
	const u_int8_t *ie, int rssi, int nf, const struct ieee80211_frame *wh);

static void
settxparms(struct ieee80211vap *vap, enum ieee80211_phymode mode, int rate)
{
	vap->iv_txparms[mode].ucastrate = rate;
	vap->iv_txparms[mode].mcastrate = rate;
}

static void
setackpolicy(struct ieee80211com *ic, int noack)
{
	struct ieee80211_wme_state *wme = &ic->ic_wme;
	int ac;

	for (ac = 0; ac < WME_NUM_AC; ac++) {
		wme->wme_chanParams.cap_wmeParams[ac].wmep_noackPolicy = noack;
		wme->wme_wmeChanParams.cap_wmeParams[ac].wmep_noackPolicy = noack;
	}
}

void
ieee80211_tdma_vattach(struct ieee80211vap *vap)
{
	struct ieee80211_tdma_state *ts;

	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
	     ("not a tdma vap, caps 0x%x", vap->iv_caps));

	ts = (struct ieee80211_tdma_state *) IEEE80211_MALLOC(
	     sizeof(struct ieee80211_tdma_state), M_80211_VAP,
	     IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
	if (ts == NULL) {
		printf("%s: cannot allocate TDMA state block\n", __func__);
		/* NB: fall back to adhdemo mode */
		vap->iv_caps &= ~IEEE80211_C_TDMA;
		return;
	}
	/* NB: default configuration is passive so no beacons */
	ts->tdma_version = TDMA_VERSION;
	ts->tdma_slotlen = TDMA_SLOTLEN_DEFAULT;
	ts->tdma_slotcnt = TDMA_SLOTCNT_DEFAULT;
	ts->tdma_bintval = TDMA_BINTVAL_DEFAULT;
	ts->tdma_slot = 1;			/* passive operation */

	/* setup default fixed rates */
	settxparms(vap, IEEE80211_MODE_11A, TDMA_TXRATE_11A_DEFAULT);
	settxparms(vap, IEEE80211_MODE_11B, TDMA_TXRATE_11B_DEFAULT);
	settxparms(vap, IEEE80211_MODE_11G, TDMA_TXRATE_11G_DEFAULT);
	settxparms(vap, IEEE80211_MODE_TURBO_A, TDMA_TXRATE_TURBO_DEFAULT);
	settxparms(vap, IEEE80211_MODE_TURBO_G, TDMA_TXRATE_TURBO_DEFAULT);
	settxparms(vap, IEEE80211_MODE_STURBO_A, TDMA_TXRATE_TURBO_DEFAULT);
	settxparms(vap, IEEE80211_MODE_11NA, TDMA_TXRATE_11NA_DEFAULT);
	settxparms(vap, IEEE80211_MODE_11NG, TDMA_TXRATE_11NG_DEFAULT);
	settxparms(vap, IEEE80211_MODE_HALF, TDMA_TXRATE_HALF_DEFAULT);
	settxparms(vap, IEEE80211_MODE_QUARTER, TDMA_TXRATE_QUARTER_DEFAULT);

	setackpolicy(vap->iv_ic, 1);	/* disable ACK's */

	ts->tdma_opdetach = vap->iv_opdetach;
	vap->iv_opdetach = tdma_vdetach;
	ts->tdma_newstate = vap->iv_newstate;
	vap->iv_newstate = tdma_newstate;
	vap->iv_bmiss = tdma_beacon_miss;
	ts->tdma_recv_mgmt = vap->iv_recv_mgmt;
	vap->iv_recv_mgmt = tdma_recv_mgmt;

	vap->iv_tdma = ts;
}

static void
tdma_vdetach(struct ieee80211vap *vap)
{
	struct ieee80211_tdma_state *ts = vap->iv_tdma;

	if (ts == NULL) {
		/* NB: should not have touched any ic state */
		return;
	}
	ts->tdma_opdetach(vap);
	IEEE80211_FREE(vap->iv_tdma, M_80211_VAP);
	vap->iv_tdma = NULL;

	setackpolicy(vap->iv_ic, 0);	/* enable ACK's */
}

static void
sta_leave(void *arg, struct ieee80211_node *ni)
{
	struct ieee80211vap *vap = arg;

	if (ni->ni_vap == vap && ni != vap->iv_bss)
		ieee80211_node_leave(ni);
}

/*
 * TDMA state machine handler.
 */
static int
tdma_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
{
	struct ieee80211_tdma_state *ts = vap->iv_tdma;
	struct ieee80211com *ic = vap->iv_ic;
	enum ieee80211_state ostate;
	int status;

	IEEE80211_LOCK_ASSERT(ic);

	ostate = vap->iv_state;
	IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE, "%s: %s -> %s (%d)\n",
	    __func__, ieee80211_state_name[ostate],
	    ieee80211_state_name[nstate], arg);

	if (vap->iv_flags_ext & IEEE80211_FEXT_SWBMISS)
		callout_stop(&vap->iv_swbmiss);
	if (nstate == IEEE80211_S_SCAN &&
	    (ostate == IEEE80211_S_INIT || ostate == IEEE80211_S_RUN) &&
	    ts->tdma_slot != 0) {
		/*
		 * Override adhoc behaviour when operating as a slave;
		 * we need to scan even if the channel is locked.
		 */
		vap->iv_state = nstate;			/* state transition */
		ieee80211_cancel_scan(vap);		/* background scan */
		if (ostate == IEEE80211_S_RUN) {
			/* purge station table; entries are stale */
			ieee80211_iterate_nodes(&ic->ic_sta, sta_leave, vap);
		}
		if (vap->iv_flags_ext & IEEE80211_FEXT_SCANREQ) {
			ieee80211_check_scan(vap,
			    vap->iv_scanreq_flags,
			    vap->iv_scanreq_duration,
			    vap->iv_scanreq_mindwell,
			    vap->iv_scanreq_maxdwell,
			    vap->iv_scanreq_nssid, vap->iv_scanreq_ssid);
			vap->iv_flags_ext &= ~IEEE80211_FEXT_SCANREQ;
		} else
			ieee80211_check_scan_current(vap);
		status = 0;
	} else {
		status = ts->tdma_newstate(vap, nstate, arg);
	}
	if (status == 0 && 
	    nstate == IEEE80211_S_RUN && ostate != IEEE80211_S_RUN &&
	    (vap->iv_flags_ext & IEEE80211_FEXT_SWBMISS) &&
	    ts->tdma_slot != 0 &&
	    vap->iv_des_chan == IEEE80211_CHAN_ANYC) {
		/*
		 * Start s/w beacon miss timer for slave devices w/o
		 * hardware support.  Note we do this only if we're
		 * not locked to a channel (i.e. roam to follow the
		 * master). The 2x is a fudge for our doing this in
		 * software.
		 */
		vap->iv_swbmiss_period = IEEE80211_TU_TO_TICKS(
		    2 * vap->iv_bmissthreshold * ts->tdma_bintval *
		    ((ts->tdma_slotcnt * ts->tdma_slotlen) / 1024));
		vap->iv_swbmiss_count = 0;
		callout_reset(&vap->iv_swbmiss, vap->iv_swbmiss_period,
			ieee80211_swbmiss, vap);
	}
	return status;
}

static void
tdma_beacon_miss(struct ieee80211vap *vap)
{
	struct ieee80211_tdma_state *ts = vap->iv_tdma;

	IEEE80211_LOCK_ASSERT(vap->iv_ic);

	KASSERT((vap->iv_ic->ic_flags & IEEE80211_F_SCAN) == 0, ("scanning"));
	KASSERT(vap->iv_state == IEEE80211_S_RUN,
	    ("wrong state %d", vap->iv_state));

	IEEE80211_DPRINTF(vap,
		IEEE80211_MSG_STATE | IEEE80211_MSG_TDMA | IEEE80211_MSG_DEBUG,
		"beacon miss, mode %u state %s\n",
		vap->iv_opmode, ieee80211_state_name[vap->iv_state]);

	callout_stop(&vap->iv_swbmiss);

	if (ts->tdma_peer != NULL) {	/* XXX? can this be null? */
		ieee80211_notify_node_leave(vap->iv_bss);
		ts->tdma_peer = NULL;
		/*
		 * Treat beacon miss like an associate failure wrt the
		 * scan policy; this forces the entry in the scan cache
		 * to be ignored after several tries.
		 */
		ieee80211_scan_assoc_fail(vap, vap->iv_bss->ni_macaddr,
		    IEEE80211_STATUS_TIMEOUT);
	}
#if 0
	ts->tdma_inuse = 0;		/* clear slot usage */
#endif
	ieee80211_new_state(vap, IEEE80211_S_SCAN, 0);
}

static void
tdma_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
	int subtype, const struct ieee80211_rx_stats *rxs, int rssi, int nf)
{
	struct ieee80211com *ic = ni->ni_ic;
	struct ieee80211vap *vap = ni->ni_vap;
	struct ieee80211_tdma_state *ts = vap->iv_tdma;

	if (subtype == IEEE80211_FC0_SUBTYPE_BEACON &&
	    (ic->ic_flags & IEEE80211_F_SCAN) == 0) {
		struct ieee80211_frame *wh = mtod(m0, struct ieee80211_frame *);
		struct ieee80211_scanparams scan;

		/* XXX TODO: use rxstatus to determine off-channel beacons */
		if (ieee80211_parse_beacon(ni, m0, ic->ic_curchan, &scan) != 0)
			return;
		if (scan.tdma == NULL) {
			/*
			 * TDMA stations must beacon a TDMA ie; ignore
			 * any other station.
			 * XXX detect overlapping bss and change channel
			 */
			IEEE80211_DISCARD(vap,
			    IEEE80211_MSG_ELEMID | IEEE80211_MSG_INPUT,
			    wh, ieee80211_mgt_subtype_name[subtype >>
				IEEE80211_FC0_SUBTYPE_SHIFT],
			    "%s", "no TDMA ie");
			vap->iv_stats.is_rx_mgtdiscard++;
			return;
		}
		if (ni == vap->iv_bss &&
		    !IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
			/*
			 * Fake up a node for this newly
			 * discovered member of the IBSS.
			 */
			ni = ieee80211_add_neighbor(vap, wh, &scan);
			if (ni == NULL) {
				/* NB: stat kept for alloc failure */
				return;
			}
		}
		/*
		 * Check for state updates.
		 */
		if (IEEE80211_ADDR_EQ(wh->i_addr3, ni->ni_bssid)) {
			/*
			 * Count frame now that we know it's to be processed.
			 */
			vap->iv_stats.is_rx_beacon++;
			IEEE80211_NODE_STAT(ni, rx_beacons);
			/*
			 * Record tsf of last beacon.  NB: this must be
			 * done before calling tdma_process_params
			 * as deeper routines reference it.
			 */
			memcpy(&ni->ni_tstamp.data, scan.tstamp,
				sizeof(ni->ni_tstamp.data));
			/*
			 * Count beacon frame for s/w bmiss handling.
			 */
			vap->iv_swbmiss_count++;
			/*
			 * Process tdma ie.  The contents are used to sync
			 * the slot timing, reconfigure the bss, etc.
			 */
			(void) tdma_process_params(ni, scan.tdma, rssi, nf, wh);
			return;
		}
		/*
		 * NB: defer remaining work to the adhoc code; this causes
		 *     2x parsing of the frame but should happen infrequently
		 */
	}
	ts->tdma_recv_mgmt(ni, m0, subtype, rxs, rssi, nf);
}

/*
 * Update TDMA state on receipt of a beacon frame with
 * a TDMA information element.  The sender's identity
 * is provided so we can track who our peer is.  If pickslot
 * is non-zero we scan the slot allocation state in the ie
 * to locate a free slot for our use.
 */
static int
tdma_update(struct ieee80211vap *vap, const struct ieee80211_tdma_param *tdma,
	struct ieee80211_node *ni, int pickslot)
{
	struct ieee80211_tdma_state *ts = vap->iv_tdma;
	int slot, slotlen, update;

	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
	     ("not a tdma vap, caps 0x%x", vap->iv_caps));

	update = 0;
	if (tdma->tdma_slotcnt != ts->tdma_slotcnt) {
		if (!TDMA_SLOTCNT_VALID(tdma->tdma_slotcnt)) {
			if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
				printf("%s: bad slot cnt %u\n",
				    __func__, tdma->tdma_slotcnt);
			return 0;
		}
		update |= TDMA_UPDATE_SLOTCNT;
 	}
	slotlen = le16toh(tdma->tdma_slotlen) * 100;
	if (slotlen != ts->tdma_slotlen) {
		if (!TDMA_SLOTLEN_VALID(slotlen)) {
			if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
				printf("%s: bad slot len %u\n",
				    __func__, slotlen);
			return 0;
		}
		update |= TDMA_UPDATE_SLOTLEN;
 	}
	if (tdma->tdma_bintval != ts->tdma_bintval) {
		if (!TDMA_BINTVAL_VALID(tdma->tdma_bintval)) {
			if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
				printf("%s: bad beacon interval %u\n",
				    __func__, tdma->tdma_bintval);
			return 0;
		}
		update |= TDMA_UPDATE_BINTVAL;
 	}
	slot = ts->tdma_slot;
	if (pickslot) {
		/*
		 * Pick unoccupied slot.  Note we never choose slot 0.
		 */
		for (slot = tdma->tdma_slotcnt-1; slot > 0; slot--)
			if (isclr(tdma->tdma_inuse, slot))
				break;
		if (slot <= 0) {
			printf("%s: no free slot, slotcnt %u inuse: 0x%x\n",
				__func__, tdma->tdma_slotcnt,
				tdma->tdma_inuse[0]);
			/* XXX need to do something better */
			return 0;
		}
		if (slot != ts->tdma_slot)
			update |= TDMA_UPDATE_SLOT;
	}
	if (ni != ts->tdma_peer) {
		/* update everything */
		update = TDMA_UPDATE_SLOT
		       | TDMA_UPDATE_SLOTCNT
		       | TDMA_UPDATE_SLOTLEN
		       | TDMA_UPDATE_BINTVAL;
	}

	if (update) {
		/*
		 * New/changed parameters; update runtime state.
		 */
		/* XXX overwrites user parameters */
		if (update & TDMA_UPDATE_SLOTCNT)
			ts->tdma_slotcnt = tdma->tdma_slotcnt;
		if (update & TDMA_UPDATE_SLOTLEN)
			ts->tdma_slotlen = slotlen;
		if (update & TDMA_UPDATE_SLOT)
			ts->tdma_slot = slot;
		if (update & TDMA_UPDATE_BINTVAL)
			ts->tdma_bintval = tdma->tdma_bintval;
		/* mark beacon to be updated before next xmit */
		ieee80211_beacon_notify(vap, IEEE80211_BEACON_TDMA);

		IEEE80211_DPRINTF(vap, IEEE80211_MSG_TDMA,
		    "%s: slot %u slotcnt %u slotlen %u us bintval %u\n",
		    __func__, ts->tdma_slot, ts->tdma_slotcnt,
		    ts->tdma_slotlen, ts->tdma_bintval);
	}
	/*
	 * Notify driver.  Note we can be called before
	 * entering RUN state if we scanned and are
	 * joining an existing bss.  In that case do not
	 * call the driver because not all necessary state
	 * has been setup.  The next beacon will dtrt.
	 */
	if (vap->iv_state == IEEE80211_S_RUN)
		vap->iv_ic->ic_tdma_update(ni, tdma, update);
	/*
	 * Dispatch join event on first beacon from new master.
	 */
	if (ts->tdma_peer != ni) {
		if (ts->tdma_peer != NULL)
			ieee80211_notify_node_leave(vap->iv_bss);
		ieee80211_notify_node_join(ni, 1);
		/* NB: no reference, we just use the address */
		ts->tdma_peer = ni;
	}
	return 1;
}

/*
 * Process received TDMA parameters.
 */
static int
tdma_process_params(struct ieee80211_node *ni, const u_int8_t *ie,
	int rssi, int nf, const struct ieee80211_frame *wh)
{
	struct ieee80211vap *vap = ni->ni_vap;
	struct ieee80211_tdma_state *ts = vap->iv_tdma;
	const struct ieee80211_tdma_param *tdma = 
		(const struct ieee80211_tdma_param *) ie;
	u_int len = ie[1];

	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
	     ("not a tdma vap, caps 0x%x", vap->iv_caps));

	if (len < sizeof(*tdma) - 2) {
		IEEE80211_DISCARD_IE(vap,
		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
		    wh, "tdma", "too short, len %u", len);
		return IEEE80211_REASON_IE_INVALID;
	}
	if (tdma->tdma_version != ts->tdma_version) {
		IEEE80211_DISCARD_IE(vap,
		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
		    wh, "tdma", "bad version %u (ours %u)",
		    tdma->tdma_version, ts->tdma_version);
		return IEEE80211_REASON_IE_INVALID;
	}
 	/*
	 * NB: ideally we'd check against tdma_slotcnt, but that
	 * would require extra effort so do this easy check that
	 * covers the work below; more stringent checks are done
	 * before we make more extensive use of the ie contents.
	 */
	if (tdma->tdma_slot >= TDMA_MAXSLOTS) {
		IEEE80211_DISCARD_IE(vap,
		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
		    wh, "tdma", "invalid slot %u", tdma->tdma_slot);
		return IEEE80211_REASON_IE_INVALID;
	}
	/*
	 * Can reach here while scanning, update
	 * operational state only in RUN state.
	 */
	if (vap->iv_state == IEEE80211_S_RUN) {
		if (tdma->tdma_slot != ts->tdma_slot &&
		    isclr(ts->tdma_inuse, tdma->tdma_slot)) {
			IEEE80211_NOTE(vap, IEEE80211_MSG_TDMA, ni,
			    "discovered in slot %u", tdma->tdma_slot);
			setbit(ts->tdma_inuse, tdma->tdma_slot);
			/* XXX dispatch event only when operating as master */
			if (ts->tdma_slot == 0)
				ieee80211_notify_node_join(ni, 1);
		}
		setbit(ts->tdma_active, tdma->tdma_slot);
		if (tdma->tdma_slot == ts->tdma_slot-1) {
			/*
			 * Slave tsf synchronization to station
			 * just before us in the schedule. The driver
			 * is responsible for copying the timestamp
			 * of the received beacon into our beacon
			 * frame so the sender can calculate round
			 * trip time.  We cannot do that here because
			 * we don't know how to update our beacon frame.
			 */
			(void) tdma_update(vap, tdma, ni, 0);
			/* XXX reschedule swbmiss timer on parameter change */
		} else if (tdma->tdma_slot == ts->tdma_slot+1) {
			uint64_t tstamp;
#if 0
			uint32_t rstamp = (uint32_t) le64toh(rs->tsf);
			int32_t rtt;
#endif
			/*
			 * Use returned timstamp to calculate the
			 * roundtrip time.
			 */
			memcpy(&tstamp, tdma->tdma_tstamp, 8);
#if 0
			/* XXX use only 15 bits of rstamp */
			rtt = rstamp - (le64toh(tstamp) & 0x7fff);
			if (rtt < 0)
				rtt += 0x7fff;
			/* XXX hack to quiet normal use */
			IEEE80211_DPRINTF(vap, IEEE80211_MSG_DOT1X,
			    "tdma rtt %5u [rstamp %5u tstamp %llu]\n",
			    rtt, rstamp,
			    (unsigned long long) le64toh(tstamp));
#endif
		} else if (tdma->tdma_slot == ts->tdma_slot &&
		    le64toh(ni->ni_tstamp.tsf) > vap->iv_bss->ni_tstamp.tsf) {
			/*
			 * Station using the same slot as us and has
			 * been around longer than us; we must move.
			 * Note this can happen if stations do not
			 * see each other while scanning.
			 */
			IEEE80211_DPRINTF(vap, IEEE80211_MSG_TDMA,
			    "slot %u collision rxtsf %llu tsf %llu\n",
			    tdma->tdma_slot,
			    (unsigned long long) le64toh(ni->ni_tstamp.tsf),
			    vap->iv_bss->ni_tstamp.tsf);
			setbit(ts->tdma_inuse, tdma->tdma_slot);

			(void) tdma_update(vap, tdma, ni, 1);
		}
	}
	return 0;
}

int
ieee80211_tdma_getslot(struct ieee80211vap *vap)
{
	struct ieee80211_tdma_state *ts = vap->iv_tdma;

	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
	return ts->tdma_slot;
}

/*
 * Parse a TDMA ie on station join and use it to setup node state.
 */
void
ieee80211_parse_tdma(struct ieee80211_node *ni, const uint8_t *ie)
{
	struct ieee80211vap *vap = ni->ni_vap;

	if (vap->iv_caps & IEEE80211_C_TDMA) {
		const struct ieee80211_tdma_param *tdma =
		    (const struct ieee80211_tdma_param *)ie;
		struct ieee80211_tdma_state *ts = vap->iv_tdma;
		/*
		 * Adopt TDMA configuration when joining an
		 * existing network.
		 */
		setbit(ts->tdma_inuse, tdma->tdma_slot);
		(void) tdma_update(vap, tdma, ni, 1);
		/*
		 * Propagate capabilities based on the local
		 * configuration and the remote station's advertised
		 * capabilities. In particular this permits us to
		 * enable use of QoS to disable ACK's.
		 */
		if ((vap->iv_flags & IEEE80211_F_WME) &&
		    ni->ni_ies.wme_ie != NULL)
			ni->ni_flags |= IEEE80211_NODE_QOS;
	}
}

#define	TDMA_OUI_BYTES		0x00, 0x03, 0x7f
/*
 * Add a TDMA parameters element to a frame.
 */
uint8_t *
ieee80211_add_tdma(uint8_t *frm, struct ieee80211vap *vap)
{
#define	ADDSHORT(frm, v) do {			\
	frm[0] = (v) & 0xff;			\
	frm[1] = (v) >> 8;			\
	frm += 2;				\
} while (0)
	static const struct ieee80211_tdma_param param = {
		.tdma_id	= IEEE80211_ELEMID_VENDOR,
		.tdma_len	= sizeof(struct ieee80211_tdma_param) - 2,
		.tdma_oui	= { TDMA_OUI_BYTES },
		.tdma_type	= TDMA_OUI_TYPE,
		.tdma_subtype	= TDMA_SUBTYPE_PARAM,
		.tdma_version	= TDMA_VERSION,
	};
	const struct ieee80211_tdma_state *ts = vap->iv_tdma;
	uint16_t slotlen;

	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
	     ("not a tdma vap, caps 0x%x", vap->iv_caps));

	memcpy(frm, &param, sizeof(param));
	frm += __offsetof(struct ieee80211_tdma_param, tdma_slot);
	*frm++ = ts->tdma_slot;
	*frm++ = ts->tdma_slotcnt;
	/* NB: convert units to fit in 16-bits */
	slotlen = ts->tdma_slotlen / 100;	/* 100us units */
	ADDSHORT(frm, slotlen);
	*frm++ = ts->tdma_bintval;
	*frm++ = ts->tdma_inuse[0];
	frm += 10;				/* pad+timestamp */
	return frm; 
#undef ADDSHORT
}
#undef TDMA_OUI_BYTES

/*
 * Update TDMA state at TBTT.
 */
void
ieee80211_tdma_update_beacon(struct ieee80211vap *vap,
	struct ieee80211_beacon_offsets *bo)
{
	struct ieee80211_tdma_state *ts = vap->iv_tdma;

	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
	     ("not a tdma vap, caps 0x%x", vap->iv_caps));

	if (isset(bo->bo_flags,  IEEE80211_BEACON_TDMA)) {
		(void) ieee80211_add_tdma(bo->bo_tdma, vap);
		clrbit(bo->bo_flags, IEEE80211_BEACON_TDMA);
	}
	if (ts->tdma_slot != 0)		/* only on master */
		return;
	if (ts->tdma_count <= 0) {
		/*
		 * Time to update the mask of active/inuse stations.
		 * We track stations that we've received a beacon
		 * frame from and update this mask periodically.
		 * This allows us to miss a few beacons before marking
		 * a slot free for re-use.
		 */
		ts->tdma_inuse[0] = ts->tdma_active[0];
		ts->tdma_active[0] = 0x01;
		/* update next time 'round */
		/* XXX use notify framework */
		setbit(bo->bo_flags, IEEE80211_BEACON_TDMA);
		/* NB: use s/w beacon miss threshold; may be too high */
		ts->tdma_count = vap->iv_bmissthreshold-1;
	} else
		ts->tdma_count--;
}

static int
tdma_ioctl_get80211(struct ieee80211vap *vap, struct ieee80211req *ireq)
{
	struct ieee80211_tdma_state *ts = vap->iv_tdma;

	if ((vap->iv_caps & IEEE80211_C_TDMA) == 0)
		return ENOSYS;

	switch (ireq->i_type) {
	case IEEE80211_IOC_TDMA_SLOT:
		ireq->i_val = ts->tdma_slot;
		break;
	case IEEE80211_IOC_TDMA_SLOTCNT:
		ireq->i_val = ts->tdma_slotcnt;
		break;
	case IEEE80211_IOC_TDMA_SLOTLEN:
		ireq->i_val = ts->tdma_slotlen;
		break;
	case IEEE80211_IOC_TDMA_BINTERVAL:
		ireq->i_val = ts->tdma_bintval;
		break;
	default:
		return ENOSYS;
	}
	return 0;
}
IEEE80211_IOCTL_GET(tdma, tdma_ioctl_get80211);

static int
tdma_ioctl_set80211(struct ieee80211vap *vap, struct ieee80211req *ireq)
{
	struct ieee80211_tdma_state *ts = vap->iv_tdma;

	if ((vap->iv_caps & IEEE80211_C_TDMA) == 0)
		return ENOSYS;

	switch (ireq->i_type) {
	case IEEE80211_IOC_TDMA_SLOT:
		if (!(0 <= ireq->i_val && ireq->i_val <= ts->tdma_slotcnt))
			return EINVAL;
		if (ireq->i_val != ts->tdma_slot) {
			ts->tdma_slot = ireq->i_val;
			goto restart;
		}
		break;
	case IEEE80211_IOC_TDMA_SLOTCNT:
		if (!TDMA_SLOTCNT_VALID(ireq->i_val))
			return EINVAL;
		if (ireq->i_val != ts->tdma_slotcnt) {
			ts->tdma_slotcnt = ireq->i_val;
			goto restart;
		}
		break;
	case IEEE80211_IOC_TDMA_SLOTLEN:
		/*
		 * XXX
		 * 150 insures at least 1/8 TU
		 * 0xfffff is the max duration for bursting
		 * (implict by way of 16-bit data type for i_val)
		 */
		if (!TDMA_SLOTLEN_VALID(ireq->i_val))
			return EINVAL;
		if (ireq->i_val != ts->tdma_slotlen) {
			ts->tdma_slotlen = ireq->i_val;
			goto restart;
		}
		break;
	case IEEE80211_IOC_TDMA_BINTERVAL:
		if (!TDMA_BINTVAL_VALID(ireq->i_val))
			return EINVAL;
		if (ireq->i_val != ts->tdma_bintval) {
			ts->tdma_bintval = ireq->i_val;
			goto restart;
		}
		break;
	default:
		return ENOSYS;
	}
	return 0;
restart:
	ieee80211_beacon_notify(vap, IEEE80211_BEACON_TDMA);
	return ERESTART;
}
IEEE80211_IOCTL_SET(tdma, tdma_ioctl_set80211);

#endif	/* IEEE80211_SUPPORT_TDMA */
OpenPOWER on IntegriCloud