ieee80211_tdma.c revision 283538
1/*-
2 * Copyright (c) 2007-2009 Sam Leffler, Errno Consulting
3 * Copyright (c) 2007-2009 Intel Corporation
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28#ifdef __FreeBSD__
29__FBSDID("$FreeBSD: head/sys/net80211/ieee80211_tdma.c 283538 2015-05-25 19:18:16Z adrian $");
30#endif
31
32/*
33 * IEEE 802.11 TDMA mode support.
34 */
35#include "opt_inet.h"
36#include "opt_tdma.h"
37#include "opt_wlan.h"
38
39#ifdef	IEEE80211_SUPPORT_TDMA
40
41#include <sys/param.h>
42#include <sys/systm.h>
43#include <sys/mbuf.h>
44#include <sys/malloc.h>
45#include <sys/kernel.h>
46
47#include <sys/socket.h>
48#include <sys/sockio.h>
49#include <sys/endian.h>
50#include <sys/errno.h>
51#include <sys/proc.h>
52#include <sys/sysctl.h>
53
54#include <net/if.h>
55#include <net/if_media.h>
56#include <net/if_llc.h>
57#include <net/ethernet.h>
58
59#include <net/bpf.h>
60
61#include <net80211/ieee80211_var.h>
62#include <net80211/ieee80211_tdma.h>
63#include <net80211/ieee80211_input.h>
64
65#ifndef TDMA_SLOTLEN_DEFAULT
66#define	TDMA_SLOTLEN_DEFAULT	10*1000		/* 10ms */
67#endif
68#ifndef TDMA_SLOTCNT_DEFAULT
69#define	TDMA_SLOTCNT_DEFAULT	2		/* 2x (pt-to-pt) */
70#endif
71#ifndef TDMA_BINTVAL_DEFAULT
72#define	TDMA_BINTVAL_DEFAULT	5		/* 5x ~= 100TU beacon intvl */
73#endif
74#ifndef TDMA_TXRATE_11B_DEFAULT
75#define	TDMA_TXRATE_11B_DEFAULT	2*11
76#endif
77#ifndef TDMA_TXRATE_11G_DEFAULT
78#define	TDMA_TXRATE_11G_DEFAULT	2*24
79#endif
80#ifndef TDMA_TXRATE_11A_DEFAULT
81#define	TDMA_TXRATE_11A_DEFAULT	2*24
82#endif
83#ifndef TDMA_TXRATE_TURBO_DEFAULT
84#define	TDMA_TXRATE_TURBO_DEFAULT	2*24
85#endif
86#ifndef TDMA_TXRATE_HALF_DEFAULT
87#define	TDMA_TXRATE_HALF_DEFAULT	2*12
88#endif
89#ifndef TDMA_TXRATE_QUARTER_DEFAULT
90#define	TDMA_TXRATE_QUARTER_DEFAULT	2*6
91#endif
92#ifndef TDMA_TXRATE_11NA_DEFAULT
93#define	TDMA_TXRATE_11NA_DEFAULT	(4 | IEEE80211_RATE_MCS)
94#endif
95#ifndef TDMA_TXRATE_11NG_DEFAULT
96#define	TDMA_TXRATE_11NG_DEFAULT	(4 | IEEE80211_RATE_MCS)
97#endif
98
99#define	TDMA_VERSION_VALID(_version) \
100	(TDMA_VERSION_V2 <= (_version) && (_version) <= TDMA_VERSION)
101#define	TDMA_SLOTCNT_VALID(_slotcnt) \
102	(2 <= (_slotcnt) && (_slotcnt) <= TDMA_MAXSLOTS)
103/* XXX magic constants */
104#define	TDMA_SLOTLEN_VALID(_slotlen) \
105	(2*100 <= (_slotlen) && (unsigned)(_slotlen) <= 0xfffff)
106/* XXX probably should set a max */
107#define	TDMA_BINTVAL_VALID(_bintval)	(1 <= (_bintval))
108
109/*
110 * This code is not prepared to handle more than 2 slots.
111 */
112CTASSERT(TDMA_MAXSLOTS == 2);
113
114static void tdma_vdetach(struct ieee80211vap *vap);
115static int tdma_newstate(struct ieee80211vap *, enum ieee80211_state, int);
116static void tdma_beacon_miss(struct ieee80211vap *vap);
117static void tdma_recv_mgmt(struct ieee80211_node *, struct mbuf *,
118	int subtype, const struct ieee80211_rx_stats *rxs, int rssi, int nf);
119static int tdma_update(struct ieee80211vap *vap,
120	const struct ieee80211_tdma_param *tdma, struct ieee80211_node *ni,
121	int pickslot);
122static int tdma_process_params(struct ieee80211_node *ni,
123	const u_int8_t *ie, int rssi, int nf, const struct ieee80211_frame *wh);
124
125static void
126settxparms(struct ieee80211vap *vap, enum ieee80211_phymode mode, int rate)
127{
128	vap->iv_txparms[mode].ucastrate = rate;
129	vap->iv_txparms[mode].mcastrate = rate;
130}
131
132static void
133setackpolicy(struct ieee80211com *ic, int noack)
134{
135	struct ieee80211_wme_state *wme = &ic->ic_wme;
136	int ac;
137
138	for (ac = 0; ac < WME_NUM_AC; ac++) {
139		wme->wme_chanParams.cap_wmeParams[ac].wmep_noackPolicy = noack;
140		wme->wme_wmeChanParams.cap_wmeParams[ac].wmep_noackPolicy = noack;
141	}
142}
143
144void
145ieee80211_tdma_vattach(struct ieee80211vap *vap)
146{
147	struct ieee80211_tdma_state *ts;
148
149	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
150	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
151
152	ts = (struct ieee80211_tdma_state *) IEEE80211_MALLOC(
153	     sizeof(struct ieee80211_tdma_state), M_80211_VAP,
154	     IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
155	if (ts == NULL) {
156		printf("%s: cannot allocate TDMA state block\n", __func__);
157		/* NB: fall back to adhdemo mode */
158		vap->iv_caps &= ~IEEE80211_C_TDMA;
159		return;
160	}
161	/* NB: default configuration is passive so no beacons */
162	ts->tdma_version = TDMA_VERSION;
163	ts->tdma_slotlen = TDMA_SLOTLEN_DEFAULT;
164	ts->tdma_slotcnt = TDMA_SLOTCNT_DEFAULT;
165	ts->tdma_bintval = TDMA_BINTVAL_DEFAULT;
166	ts->tdma_slot = 1;			/* passive operation */
167
168	/* setup default fixed rates */
169	settxparms(vap, IEEE80211_MODE_11A, TDMA_TXRATE_11A_DEFAULT);
170	settxparms(vap, IEEE80211_MODE_11B, TDMA_TXRATE_11B_DEFAULT);
171	settxparms(vap, IEEE80211_MODE_11G, TDMA_TXRATE_11G_DEFAULT);
172	settxparms(vap, IEEE80211_MODE_TURBO_A, TDMA_TXRATE_TURBO_DEFAULT);
173	settxparms(vap, IEEE80211_MODE_TURBO_G, TDMA_TXRATE_TURBO_DEFAULT);
174	settxparms(vap, IEEE80211_MODE_STURBO_A, TDMA_TXRATE_TURBO_DEFAULT);
175	settxparms(vap, IEEE80211_MODE_11NA, TDMA_TXRATE_11NA_DEFAULT);
176	settxparms(vap, IEEE80211_MODE_11NG, TDMA_TXRATE_11NG_DEFAULT);
177	settxparms(vap, IEEE80211_MODE_HALF, TDMA_TXRATE_HALF_DEFAULT);
178	settxparms(vap, IEEE80211_MODE_QUARTER, TDMA_TXRATE_QUARTER_DEFAULT);
179
180	setackpolicy(vap->iv_ic, 1);	/* disable ACK's */
181
182	ts->tdma_opdetach = vap->iv_opdetach;
183	vap->iv_opdetach = tdma_vdetach;
184	ts->tdma_newstate = vap->iv_newstate;
185	vap->iv_newstate = tdma_newstate;
186	vap->iv_bmiss = tdma_beacon_miss;
187	ts->tdma_recv_mgmt = vap->iv_recv_mgmt;
188	vap->iv_recv_mgmt = tdma_recv_mgmt;
189
190	vap->iv_tdma = ts;
191}
192
193static void
194tdma_vdetach(struct ieee80211vap *vap)
195{
196	struct ieee80211_tdma_state *ts = vap->iv_tdma;
197
198	if (ts == NULL) {
199		/* NB: should not have touched any ic state */
200		return;
201	}
202	ts->tdma_opdetach(vap);
203	IEEE80211_FREE(vap->iv_tdma, M_80211_VAP);
204	vap->iv_tdma = NULL;
205
206	setackpolicy(vap->iv_ic, 0);	/* enable ACK's */
207}
208
209static void
210sta_leave(void *arg, struct ieee80211_node *ni)
211{
212	struct ieee80211vap *vap = arg;
213
214	if (ni->ni_vap == vap && ni != vap->iv_bss)
215		ieee80211_node_leave(ni);
216}
217
218/*
219 * TDMA state machine handler.
220 */
221static int
222tdma_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
223{
224	struct ieee80211_tdma_state *ts = vap->iv_tdma;
225	struct ieee80211com *ic = vap->iv_ic;
226	enum ieee80211_state ostate;
227	int status;
228
229	IEEE80211_LOCK_ASSERT(ic);
230
231	ostate = vap->iv_state;
232	IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE, "%s: %s -> %s (%d)\n",
233	    __func__, ieee80211_state_name[ostate],
234	    ieee80211_state_name[nstate], arg);
235
236	if (vap->iv_flags_ext & IEEE80211_FEXT_SWBMISS)
237		callout_stop(&vap->iv_swbmiss);
238	if (nstate == IEEE80211_S_SCAN &&
239	    (ostate == IEEE80211_S_INIT || ostate == IEEE80211_S_RUN) &&
240	    ts->tdma_slot != 0) {
241		/*
242		 * Override adhoc behaviour when operating as a slave;
243		 * we need to scan even if the channel is locked.
244		 */
245		vap->iv_state = nstate;			/* state transition */
246		ieee80211_cancel_scan(vap);		/* background scan */
247		if (ostate == IEEE80211_S_RUN) {
248			/* purge station table; entries are stale */
249			ieee80211_iterate_nodes(&ic->ic_sta, sta_leave, vap);
250		}
251		if (vap->iv_flags_ext & IEEE80211_FEXT_SCANREQ) {
252			ieee80211_check_scan(vap,
253			    vap->iv_scanreq_flags,
254			    vap->iv_scanreq_duration,
255			    vap->iv_scanreq_mindwell,
256			    vap->iv_scanreq_maxdwell,
257			    vap->iv_scanreq_nssid, vap->iv_scanreq_ssid);
258			vap->iv_flags_ext &= ~IEEE80211_FEXT_SCANREQ;
259		} else
260			ieee80211_check_scan_current(vap);
261		status = 0;
262	} else {
263		status = ts->tdma_newstate(vap, nstate, arg);
264	}
265	if (status == 0 &&
266	    nstate == IEEE80211_S_RUN && ostate != IEEE80211_S_RUN &&
267	    (vap->iv_flags_ext & IEEE80211_FEXT_SWBMISS) &&
268	    ts->tdma_slot != 0 &&
269	    vap->iv_des_chan == IEEE80211_CHAN_ANYC) {
270		/*
271		 * Start s/w beacon miss timer for slave devices w/o
272		 * hardware support.  Note we do this only if we're
273		 * not locked to a channel (i.e. roam to follow the
274		 * master). The 2x is a fudge for our doing this in
275		 * software.
276		 */
277		vap->iv_swbmiss_period = IEEE80211_TU_TO_TICKS(
278		    2 * vap->iv_bmissthreshold * ts->tdma_bintval *
279		    ((ts->tdma_slotcnt * ts->tdma_slotlen) / 1024));
280		vap->iv_swbmiss_count = 0;
281		callout_reset(&vap->iv_swbmiss, vap->iv_swbmiss_period,
282			ieee80211_swbmiss, vap);
283	}
284	return status;
285}
286
287static void
288tdma_beacon_miss(struct ieee80211vap *vap)
289{
290	struct ieee80211_tdma_state *ts = vap->iv_tdma;
291
292	IEEE80211_LOCK_ASSERT(vap->iv_ic);
293
294	KASSERT((vap->iv_ic->ic_flags & IEEE80211_F_SCAN) == 0, ("scanning"));
295	KASSERT(vap->iv_state == IEEE80211_S_RUN,
296	    ("wrong state %d", vap->iv_state));
297
298	IEEE80211_DPRINTF(vap,
299		IEEE80211_MSG_STATE | IEEE80211_MSG_TDMA | IEEE80211_MSG_DEBUG,
300		"beacon miss, mode %u state %s\n",
301		vap->iv_opmode, ieee80211_state_name[vap->iv_state]);
302
303	callout_stop(&vap->iv_swbmiss);
304
305	if (ts->tdma_peer != NULL) {	/* XXX? can this be null? */
306		ieee80211_notify_node_leave(vap->iv_bss);
307		ts->tdma_peer = NULL;
308		/*
309		 * Treat beacon miss like an associate failure wrt the
310		 * scan policy; this forces the entry in the scan cache
311		 * to be ignored after several tries.
312		 */
313		ieee80211_scan_assoc_fail(vap, vap->iv_bss->ni_macaddr,
314		    IEEE80211_STATUS_TIMEOUT);
315	}
316#if 0
317	ts->tdma_inuse = 0;		/* clear slot usage */
318#endif
319	ieee80211_new_state(vap, IEEE80211_S_SCAN, 0);
320}
321
322static void
323tdma_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
324	int subtype, const struct ieee80211_rx_stats *rxs, int rssi, int nf)
325{
326	struct ieee80211com *ic = ni->ni_ic;
327	struct ieee80211vap *vap = ni->ni_vap;
328	struct ieee80211_tdma_state *ts = vap->iv_tdma;
329
330	if (subtype == IEEE80211_FC0_SUBTYPE_BEACON &&
331	    (ic->ic_flags & IEEE80211_F_SCAN) == 0) {
332		struct ieee80211_frame *wh = mtod(m0, struct ieee80211_frame *);
333		struct ieee80211_scanparams scan;
334
335		/* XXX TODO: use rxstatus to determine off-channel beacons */
336		if (ieee80211_parse_beacon(ni, m0, ic->ic_curchan, &scan) != 0)
337			return;
338		if (scan.tdma == NULL) {
339			/*
340			 * TDMA stations must beacon a TDMA ie; ignore
341			 * any other station.
342			 * XXX detect overlapping bss and change channel
343			 */
344			IEEE80211_DISCARD(vap,
345			    IEEE80211_MSG_ELEMID | IEEE80211_MSG_INPUT,
346			    wh, ieee80211_mgt_subtype_name[subtype >>
347				IEEE80211_FC0_SUBTYPE_SHIFT],
348			    "%s", "no TDMA ie");
349			vap->iv_stats.is_rx_mgtdiscard++;
350			return;
351		}
352		if (ni == vap->iv_bss &&
353		    !IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
354			/*
355			 * Fake up a node for this newly
356			 * discovered member of the IBSS.
357			 */
358			ni = ieee80211_add_neighbor(vap, wh, &scan);
359			if (ni == NULL) {
360				/* NB: stat kept for alloc failure */
361				return;
362			}
363		}
364		/*
365		 * Check for state updates.
366		 */
367		if (IEEE80211_ADDR_EQ(wh->i_addr3, ni->ni_bssid)) {
368			/*
369			 * Count frame now that we know it's to be processed.
370			 */
371			vap->iv_stats.is_rx_beacon++;
372			IEEE80211_NODE_STAT(ni, rx_beacons);
373			/*
374			 * Record tsf of last beacon.  NB: this must be
375			 * done before calling tdma_process_params
376			 * as deeper routines reference it.
377			 */
378			memcpy(&ni->ni_tstamp.data, scan.tstamp,
379				sizeof(ni->ni_tstamp.data));
380			/*
381			 * Count beacon frame for s/w bmiss handling.
382			 */
383			vap->iv_swbmiss_count++;
384			/*
385			 * Process tdma ie.  The contents are used to sync
386			 * the slot timing, reconfigure the bss, etc.
387			 */
388			(void) tdma_process_params(ni, scan.tdma, rssi, nf, wh);
389			return;
390		}
391		/*
392		 * NB: defer remaining work to the adhoc code; this causes
393		 *     2x parsing of the frame but should happen infrequently
394		 */
395	}
396	ts->tdma_recv_mgmt(ni, m0, subtype, rxs, rssi, nf);
397}
398
399/*
400 * Update TDMA state on receipt of a beacon frame with
401 * a TDMA information element.  The sender's identity
402 * is provided so we can track who our peer is.  If pickslot
403 * is non-zero we scan the slot allocation state in the ie
404 * to locate a free slot for our use.
405 */
406static int
407tdma_update(struct ieee80211vap *vap, const struct ieee80211_tdma_param *tdma,
408	struct ieee80211_node *ni, int pickslot)
409{
410	struct ieee80211_tdma_state *ts = vap->iv_tdma;
411	int slot, slotlen, update;
412
413	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
414	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
415
416	update = 0;
417	if (tdma->tdma_slotcnt != ts->tdma_slotcnt) {
418		if (!TDMA_SLOTCNT_VALID(tdma->tdma_slotcnt)) {
419			if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
420				printf("%s: bad slot cnt %u\n",
421				    __func__, tdma->tdma_slotcnt);
422			return 0;
423		}
424		update |= TDMA_UPDATE_SLOTCNT;
425 	}
426	slotlen = le16toh(tdma->tdma_slotlen) * 100;
427	if (slotlen != ts->tdma_slotlen) {
428		if (!TDMA_SLOTLEN_VALID(slotlen)) {
429			if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
430				printf("%s: bad slot len %u\n",
431				    __func__, slotlen);
432			return 0;
433		}
434		update |= TDMA_UPDATE_SLOTLEN;
435 	}
436	if (tdma->tdma_bintval != ts->tdma_bintval) {
437		if (!TDMA_BINTVAL_VALID(tdma->tdma_bintval)) {
438			if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
439				printf("%s: bad beacon interval %u\n",
440				    __func__, tdma->tdma_bintval);
441			return 0;
442		}
443		update |= TDMA_UPDATE_BINTVAL;
444 	}
445	slot = ts->tdma_slot;
446	if (pickslot) {
447		/*
448		 * Pick unoccupied slot.  Note we never choose slot 0.
449		 */
450		for (slot = tdma->tdma_slotcnt-1; slot > 0; slot--)
451			if (isclr(tdma->tdma_inuse, slot))
452				break;
453		if (slot <= 0) {
454			printf("%s: no free slot, slotcnt %u inuse: 0x%x\n",
455				__func__, tdma->tdma_slotcnt,
456				tdma->tdma_inuse[0]);
457			/* XXX need to do something better */
458			return 0;
459		}
460		if (slot != ts->tdma_slot)
461			update |= TDMA_UPDATE_SLOT;
462	}
463	if (ni != ts->tdma_peer) {
464		/* update everything */
465		update = TDMA_UPDATE_SLOT
466		       | TDMA_UPDATE_SLOTCNT
467		       | TDMA_UPDATE_SLOTLEN
468		       | TDMA_UPDATE_BINTVAL;
469	}
470
471	if (update) {
472		/*
473		 * New/changed parameters; update runtime state.
474		 */
475		/* XXX overwrites user parameters */
476		if (update & TDMA_UPDATE_SLOTCNT)
477			ts->tdma_slotcnt = tdma->tdma_slotcnt;
478		if (update & TDMA_UPDATE_SLOTLEN)
479			ts->tdma_slotlen = slotlen;
480		if (update & TDMA_UPDATE_SLOT)
481			ts->tdma_slot = slot;
482		if (update & TDMA_UPDATE_BINTVAL)
483			ts->tdma_bintval = tdma->tdma_bintval;
484		/* mark beacon to be updated before next xmit */
485		ieee80211_beacon_notify(vap, IEEE80211_BEACON_TDMA);
486
487		IEEE80211_DPRINTF(vap, IEEE80211_MSG_TDMA,
488		    "%s: slot %u slotcnt %u slotlen %u us bintval %u\n",
489		    __func__, ts->tdma_slot, ts->tdma_slotcnt,
490		    ts->tdma_slotlen, ts->tdma_bintval);
491	}
492	/*
493	 * Notify driver.  Note we can be called before
494	 * entering RUN state if we scanned and are
495	 * joining an existing bss.  In that case do not
496	 * call the driver because not all necessary state
497	 * has been setup.  The next beacon will dtrt.
498	 */
499	if (vap->iv_state == IEEE80211_S_RUN)
500		vap->iv_ic->ic_tdma_update(ni, tdma, update);
501	/*
502	 * Dispatch join event on first beacon from new master.
503	 */
504	if (ts->tdma_peer != ni) {
505		if (ts->tdma_peer != NULL)
506			ieee80211_notify_node_leave(vap->iv_bss);
507		ieee80211_notify_node_join(ni, 1);
508		/* NB: no reference, we just use the address */
509		ts->tdma_peer = ni;
510	}
511	return 1;
512}
513
514/*
515 * Process received TDMA parameters.
516 */
517static int
518tdma_process_params(struct ieee80211_node *ni, const u_int8_t *ie,
519	int rssi, int nf, const struct ieee80211_frame *wh)
520{
521	struct ieee80211vap *vap = ni->ni_vap;
522	struct ieee80211_tdma_state *ts = vap->iv_tdma;
523	const struct ieee80211_tdma_param *tdma =
524		(const struct ieee80211_tdma_param *) ie;
525	u_int len = ie[1];
526
527	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
528	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
529
530	if (len < sizeof(*tdma) - 2) {
531		IEEE80211_DISCARD_IE(vap,
532		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
533		    wh, "tdma", "too short, len %u", len);
534		return IEEE80211_REASON_IE_INVALID;
535	}
536	if (tdma->tdma_version != ts->tdma_version) {
537		IEEE80211_DISCARD_IE(vap,
538		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
539		    wh, "tdma", "bad version %u (ours %u)",
540		    tdma->tdma_version, ts->tdma_version);
541		return IEEE80211_REASON_IE_INVALID;
542	}
543 	/*
544	 * NB: ideally we'd check against tdma_slotcnt, but that
545	 * would require extra effort so do this easy check that
546	 * covers the work below; more stringent checks are done
547	 * before we make more extensive use of the ie contents.
548	 */
549	if (tdma->tdma_slot >= TDMA_MAXSLOTS) {
550		IEEE80211_DISCARD_IE(vap,
551		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
552		    wh, "tdma", "invalid slot %u", tdma->tdma_slot);
553		return IEEE80211_REASON_IE_INVALID;
554	}
555	/*
556	 * Can reach here while scanning, update
557	 * operational state only in RUN state.
558	 */
559	if (vap->iv_state == IEEE80211_S_RUN) {
560		if (tdma->tdma_slot != ts->tdma_slot &&
561		    isclr(ts->tdma_inuse, tdma->tdma_slot)) {
562			IEEE80211_NOTE(vap, IEEE80211_MSG_TDMA, ni,
563			    "discovered in slot %u", tdma->tdma_slot);
564			setbit(ts->tdma_inuse, tdma->tdma_slot);
565			/* XXX dispatch event only when operating as master */
566			if (ts->tdma_slot == 0)
567				ieee80211_notify_node_join(ni, 1);
568		}
569		setbit(ts->tdma_active, tdma->tdma_slot);
570		if (tdma->tdma_slot == ts->tdma_slot-1) {
571			/*
572			 * Slave tsf synchronization to station
573			 * just before us in the schedule. The driver
574			 * is responsible for copying the timestamp
575			 * of the received beacon into our beacon
576			 * frame so the sender can calculate round
577			 * trip time.  We cannot do that here because
578			 * we don't know how to update our beacon frame.
579			 */
580			(void) tdma_update(vap, tdma, ni, 0);
581			/* XXX reschedule swbmiss timer on parameter change */
582		} else if (tdma->tdma_slot == ts->tdma_slot+1) {
583			uint64_t tstamp;
584#if 0
585			uint32_t rstamp = (uint32_t) le64toh(rs->tsf);
586			int32_t rtt;
587#endif
588			/*
589			 * Use returned timstamp to calculate the
590			 * roundtrip time.
591			 */
592			memcpy(&tstamp, tdma->tdma_tstamp, 8);
593#if 0
594			/* XXX use only 15 bits of rstamp */
595			rtt = rstamp - (le64toh(tstamp) & 0x7fff);
596			if (rtt < 0)
597				rtt += 0x7fff;
598			/* XXX hack to quiet normal use */
599			IEEE80211_DPRINTF(vap, IEEE80211_MSG_DOT1X,
600			    "tdma rtt %5u [rstamp %5u tstamp %llu]\n",
601			    rtt, rstamp,
602			    (unsigned long long) le64toh(tstamp));
603#endif
604		} else if (tdma->tdma_slot == ts->tdma_slot &&
605		    le64toh(ni->ni_tstamp.tsf) > vap->iv_bss->ni_tstamp.tsf) {
606			/*
607			 * Station using the same slot as us and has
608			 * been around longer than us; we must move.
609			 * Note this can happen if stations do not
610			 * see each other while scanning.
611			 */
612			IEEE80211_DPRINTF(vap, IEEE80211_MSG_TDMA,
613			    "slot %u collision rxtsf %llu tsf %llu\n",
614			    tdma->tdma_slot,
615			    (unsigned long long) le64toh(ni->ni_tstamp.tsf),
616			    vap->iv_bss->ni_tstamp.tsf);
617			setbit(ts->tdma_inuse, tdma->tdma_slot);
618
619			(void) tdma_update(vap, tdma, ni, 1);
620		}
621	}
622	return 0;
623}
624
625int
626ieee80211_tdma_getslot(struct ieee80211vap *vap)
627{
628	struct ieee80211_tdma_state *ts = vap->iv_tdma;
629
630	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
631	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
632	return ts->tdma_slot;
633}
634
635/*
636 * Parse a TDMA ie on station join and use it to setup node state.
637 */
638void
639ieee80211_parse_tdma(struct ieee80211_node *ni, const uint8_t *ie)
640{
641	struct ieee80211vap *vap = ni->ni_vap;
642
643	if (vap->iv_caps & IEEE80211_C_TDMA) {
644		const struct ieee80211_tdma_param *tdma =
645		    (const struct ieee80211_tdma_param *)ie;
646		struct ieee80211_tdma_state *ts = vap->iv_tdma;
647		/*
648		 * Adopt TDMA configuration when joining an
649		 * existing network.
650		 */
651		setbit(ts->tdma_inuse, tdma->tdma_slot);
652		(void) tdma_update(vap, tdma, ni, 1);
653		/*
654		 * Propagate capabilities based on the local
655		 * configuration and the remote station's advertised
656		 * capabilities. In particular this permits us to
657		 * enable use of QoS to disable ACK's.
658		 */
659		if ((vap->iv_flags & IEEE80211_F_WME) &&
660		    ni->ni_ies.wme_ie != NULL)
661			ni->ni_flags |= IEEE80211_NODE_QOS;
662	}
663}
664
665#define	TDMA_OUI_BYTES		0x00, 0x03, 0x7f
666/*
667 * Add a TDMA parameters element to a frame.
668 */
669uint8_t *
670ieee80211_add_tdma(uint8_t *frm, struct ieee80211vap *vap)
671{
672#define	ADDSHORT(frm, v) do {			\
673	frm[0] = (v) & 0xff;			\
674	frm[1] = (v) >> 8;			\
675	frm += 2;				\
676} while (0)
677	static const struct ieee80211_tdma_param param = {
678		.tdma_id	= IEEE80211_ELEMID_VENDOR,
679		.tdma_len	= sizeof(struct ieee80211_tdma_param) - 2,
680		.tdma_oui	= { TDMA_OUI_BYTES },
681		.tdma_type	= TDMA_OUI_TYPE,
682		.tdma_subtype	= TDMA_SUBTYPE_PARAM,
683		.tdma_version	= TDMA_VERSION,
684	};
685	const struct ieee80211_tdma_state *ts = vap->iv_tdma;
686	uint16_t slotlen;
687
688	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
689	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
690
691	memcpy(frm, &param, sizeof(param));
692	frm += __offsetof(struct ieee80211_tdma_param, tdma_slot);
693	*frm++ = ts->tdma_slot;
694	*frm++ = ts->tdma_slotcnt;
695	/* NB: convert units to fit in 16-bits */
696	slotlen = ts->tdma_slotlen / 100;	/* 100us units */
697	ADDSHORT(frm, slotlen);
698	*frm++ = ts->tdma_bintval;
699	*frm++ = ts->tdma_inuse[0];
700	frm += 10;				/* pad+timestamp */
701	return frm;
702#undef ADDSHORT
703}
704#undef TDMA_OUI_BYTES
705
706/*
707 * Update TDMA state at TBTT.
708 */
709void
710ieee80211_tdma_update_beacon(struct ieee80211vap *vap,
711	struct ieee80211_beacon_offsets *bo)
712{
713	struct ieee80211_tdma_state *ts = vap->iv_tdma;
714
715	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
716	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
717
718	if (isset(bo->bo_flags,  IEEE80211_BEACON_TDMA)) {
719		(void) ieee80211_add_tdma(bo->bo_tdma, vap);
720		clrbit(bo->bo_flags, IEEE80211_BEACON_TDMA);
721	}
722	if (ts->tdma_slot != 0)		/* only on master */
723		return;
724	if (ts->tdma_count <= 0) {
725		/*
726		 * Time to update the mask of active/inuse stations.
727		 * We track stations that we've received a beacon
728		 * frame from and update this mask periodically.
729		 * This allows us to miss a few beacons before marking
730		 * a slot free for re-use.
731		 */
732		ts->tdma_inuse[0] = ts->tdma_active[0];
733		ts->tdma_active[0] = 0x01;
734		/* update next time 'round */
735		/* XXX use notify framework */
736		setbit(bo->bo_flags, IEEE80211_BEACON_TDMA);
737		/* NB: use s/w beacon miss threshold; may be too high */
738		ts->tdma_count = vap->iv_bmissthreshold-1;
739	} else
740		ts->tdma_count--;
741}
742
743static int
744tdma_ioctl_get80211(struct ieee80211vap *vap, struct ieee80211req *ireq)
745{
746	struct ieee80211_tdma_state *ts = vap->iv_tdma;
747
748	if ((vap->iv_caps & IEEE80211_C_TDMA) == 0)
749		return ENOSYS;
750
751	switch (ireq->i_type) {
752	case IEEE80211_IOC_TDMA_SLOT:
753		ireq->i_val = ts->tdma_slot;
754		break;
755	case IEEE80211_IOC_TDMA_SLOTCNT:
756		ireq->i_val = ts->tdma_slotcnt;
757		break;
758	case IEEE80211_IOC_TDMA_SLOTLEN:
759		ireq->i_val = ts->tdma_slotlen;
760		break;
761	case IEEE80211_IOC_TDMA_BINTERVAL:
762		ireq->i_val = ts->tdma_bintval;
763		break;
764	default:
765		return ENOSYS;
766	}
767	return 0;
768}
769IEEE80211_IOCTL_GET(tdma, tdma_ioctl_get80211);
770
771static int
772tdma_ioctl_set80211(struct ieee80211vap *vap, struct ieee80211req *ireq)
773{
774	struct ieee80211_tdma_state *ts = vap->iv_tdma;
775
776	if ((vap->iv_caps & IEEE80211_C_TDMA) == 0)
777		return ENOSYS;
778
779	switch (ireq->i_type) {
780	case IEEE80211_IOC_TDMA_SLOT:
781		if (!(0 <= ireq->i_val && ireq->i_val <= ts->tdma_slotcnt))
782			return EINVAL;
783		if (ireq->i_val != ts->tdma_slot) {
784			ts->tdma_slot = ireq->i_val;
785			goto restart;
786		}
787		break;
788	case IEEE80211_IOC_TDMA_SLOTCNT:
789		if (!TDMA_SLOTCNT_VALID(ireq->i_val))
790			return EINVAL;
791		if (ireq->i_val != ts->tdma_slotcnt) {
792			ts->tdma_slotcnt = ireq->i_val;
793			goto restart;
794		}
795		break;
796	case IEEE80211_IOC_TDMA_SLOTLEN:
797		/*
798		 * XXX
799		 * 150 insures at least 1/8 TU
800		 * 0xfffff is the max duration for bursting
801		 * (implict by way of 16-bit data type for i_val)
802		 */
803		if (!TDMA_SLOTLEN_VALID(ireq->i_val))
804			return EINVAL;
805		if (ireq->i_val != ts->tdma_slotlen) {
806			ts->tdma_slotlen = ireq->i_val;
807			goto restart;
808		}
809		break;
810	case IEEE80211_IOC_TDMA_BINTERVAL:
811		if (!TDMA_BINTVAL_VALID(ireq->i_val))
812			return EINVAL;
813		if (ireq->i_val != ts->tdma_bintval) {
814			ts->tdma_bintval = ireq->i_val;
815			goto restart;
816		}
817		break;
818	default:
819		return ENOSYS;
820	}
821	return 0;
822restart:
823	ieee80211_beacon_notify(vap, IEEE80211_BEACON_TDMA);
824	return ERESTART;
825}
826IEEE80211_IOCTL_SET(tdma, tdma_ioctl_set80211);
827
828#endif	/* IEEE80211_SUPPORT_TDMA */
829