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: stable/11/sys/net80211/ieee80211_tdma.c 344225 2019-02-17 03:21:42Z avos $");
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	if (isclr(vap->iv_ic->ic_modecaps, mode))
129		return;
130
131	vap->iv_txparms[mode].ucastrate = rate;
132	vap->iv_txparms[mode].mcastrate = rate;
133}
134
135static void
136setackpolicy(struct ieee80211com *ic, int noack)
137{
138	struct ieee80211_wme_state *wme = &ic->ic_wme;
139	int ac;
140
141	for (ac = 0; ac < WME_NUM_AC; ac++) {
142		wme->wme_chanParams.cap_wmeParams[ac].wmep_noackPolicy = noack;
143		wme->wme_wmeChanParams.cap_wmeParams[ac].wmep_noackPolicy = noack;
144	}
145}
146
147void
148ieee80211_tdma_vattach(struct ieee80211vap *vap)
149{
150	struct ieee80211_tdma_state *ts;
151
152	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
153	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
154
155	ts = (struct ieee80211_tdma_state *) IEEE80211_MALLOC(
156	     sizeof(struct ieee80211_tdma_state), M_80211_VAP,
157	     IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
158	if (ts == NULL) {
159		printf("%s: cannot allocate TDMA state block\n", __func__);
160		/* NB: fall back to adhdemo mode */
161		vap->iv_caps &= ~IEEE80211_C_TDMA;
162		return;
163	}
164	/* NB: default configuration is passive so no beacons */
165	ts->tdma_version = TDMA_VERSION;
166	ts->tdma_slotlen = TDMA_SLOTLEN_DEFAULT;
167	ts->tdma_slotcnt = TDMA_SLOTCNT_DEFAULT;
168	ts->tdma_bintval = TDMA_BINTVAL_DEFAULT;
169	ts->tdma_slot = 1;			/* passive operation */
170
171	/* setup default fixed rates */
172	settxparms(vap, IEEE80211_MODE_11A, TDMA_TXRATE_11A_DEFAULT);
173	settxparms(vap, IEEE80211_MODE_11B, TDMA_TXRATE_11B_DEFAULT);
174	settxparms(vap, IEEE80211_MODE_11G, TDMA_TXRATE_11G_DEFAULT);
175	settxparms(vap, IEEE80211_MODE_TURBO_A, TDMA_TXRATE_TURBO_DEFAULT);
176	settxparms(vap, IEEE80211_MODE_TURBO_G, TDMA_TXRATE_TURBO_DEFAULT);
177	settxparms(vap, IEEE80211_MODE_STURBO_A, TDMA_TXRATE_TURBO_DEFAULT);
178	settxparms(vap, IEEE80211_MODE_11NA, TDMA_TXRATE_11NA_DEFAULT);
179	settxparms(vap, IEEE80211_MODE_11NG, TDMA_TXRATE_11NG_DEFAULT);
180	settxparms(vap, IEEE80211_MODE_HALF, TDMA_TXRATE_HALF_DEFAULT);
181	settxparms(vap, IEEE80211_MODE_QUARTER, TDMA_TXRATE_QUARTER_DEFAULT);
182
183	setackpolicy(vap->iv_ic, 1);	/* disable ACK's */
184
185	ts->tdma_opdetach = vap->iv_opdetach;
186	vap->iv_opdetach = tdma_vdetach;
187	ts->tdma_newstate = vap->iv_newstate;
188	vap->iv_newstate = tdma_newstate;
189	vap->iv_bmiss = tdma_beacon_miss;
190	ts->tdma_recv_mgmt = vap->iv_recv_mgmt;
191	vap->iv_recv_mgmt = tdma_recv_mgmt;
192
193	vap->iv_tdma = ts;
194}
195
196static void
197tdma_vdetach(struct ieee80211vap *vap)
198{
199	struct ieee80211_tdma_state *ts = vap->iv_tdma;
200
201	if (ts == NULL) {
202		/* NB: should not have touched any ic state */
203		return;
204	}
205	ts->tdma_opdetach(vap);
206	IEEE80211_FREE(vap->iv_tdma, M_80211_VAP);
207	vap->iv_tdma = NULL;
208
209	setackpolicy(vap->iv_ic, 0);	/* enable ACK's */
210}
211
212static void
213sta_leave(void *arg, struct ieee80211_node *ni)
214{
215	struct ieee80211vap *vap = arg;
216
217	if (ni->ni_vap == vap && ni != vap->iv_bss)
218		ieee80211_node_leave(ni);
219}
220
221/*
222 * TDMA state machine handler.
223 */
224static int
225tdma_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
226{
227	struct ieee80211_tdma_state *ts = vap->iv_tdma;
228	struct ieee80211com *ic = vap->iv_ic;
229	enum ieee80211_state ostate;
230	int status;
231
232	IEEE80211_LOCK_ASSERT(ic);
233
234	ostate = vap->iv_state;
235	IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE, "%s: %s -> %s (%d)\n",
236	    __func__, ieee80211_state_name[ostate],
237	    ieee80211_state_name[nstate], arg);
238
239	if (vap->iv_flags_ext & IEEE80211_FEXT_SWBMISS)
240		callout_stop(&vap->iv_swbmiss);
241	if (nstate == IEEE80211_S_SCAN &&
242	    (ostate == IEEE80211_S_INIT || ostate == IEEE80211_S_RUN) &&
243	    ts->tdma_slot != 0) {
244		/*
245		 * Override adhoc behaviour when operating as a slave;
246		 * we need to scan even if the channel is locked.
247		 */
248		vap->iv_state = nstate;			/* state transition */
249		ieee80211_cancel_scan(vap);		/* background scan */
250		if (ostate == IEEE80211_S_RUN) {
251			/* purge station table; entries are stale */
252			ieee80211_iterate_nodes(&ic->ic_sta, sta_leave, vap);
253		}
254		if (vap->iv_flags_ext & IEEE80211_FEXT_SCANREQ) {
255			ieee80211_check_scan(vap,
256			    vap->iv_scanreq_flags,
257			    vap->iv_scanreq_duration,
258			    vap->iv_scanreq_mindwell,
259			    vap->iv_scanreq_maxdwell,
260			    vap->iv_scanreq_nssid, vap->iv_scanreq_ssid);
261			vap->iv_flags_ext &= ~IEEE80211_FEXT_SCANREQ;
262		} else
263			ieee80211_check_scan_current(vap);
264		status = 0;
265	} else {
266		status = ts->tdma_newstate(vap, nstate, arg);
267	}
268	if (status == 0 &&
269	    nstate == IEEE80211_S_RUN && ostate != IEEE80211_S_RUN &&
270	    (vap->iv_flags_ext & IEEE80211_FEXT_SWBMISS) &&
271	    ts->tdma_slot != 0 &&
272	    vap->iv_des_chan == IEEE80211_CHAN_ANYC) {
273		/*
274		 * Start s/w beacon miss timer for slave devices w/o
275		 * hardware support.  Note we do this only if we're
276		 * not locked to a channel (i.e. roam to follow the
277		 * master). The 2x is a fudge for our doing this in
278		 * software.
279		 */
280		vap->iv_swbmiss_period = IEEE80211_TU_TO_TICKS(
281		    2 * vap->iv_bmissthreshold * ts->tdma_bintval *
282		    ((ts->tdma_slotcnt * ts->tdma_slotlen) / 1024));
283		vap->iv_swbmiss_count = 0;
284		callout_reset(&vap->iv_swbmiss, vap->iv_swbmiss_period,
285			ieee80211_swbmiss, vap);
286	}
287	return status;
288}
289
290static void
291tdma_beacon_miss(struct ieee80211vap *vap)
292{
293	struct ieee80211_tdma_state *ts = vap->iv_tdma;
294
295	IEEE80211_LOCK_ASSERT(vap->iv_ic);
296
297	KASSERT((vap->iv_ic->ic_flags & IEEE80211_F_SCAN) == 0, ("scanning"));
298	KASSERT(vap->iv_state == IEEE80211_S_RUN,
299	    ("wrong state %d", vap->iv_state));
300
301	IEEE80211_DPRINTF(vap,
302		IEEE80211_MSG_STATE | IEEE80211_MSG_TDMA | IEEE80211_MSG_DEBUG,
303		"beacon miss, mode %u state %s\n",
304		vap->iv_opmode, ieee80211_state_name[vap->iv_state]);
305
306	callout_stop(&vap->iv_swbmiss);
307
308	if (ts->tdma_peer != NULL) {	/* XXX? can this be null? */
309		ieee80211_notify_node_leave(vap->iv_bss);
310		ts->tdma_peer = NULL;
311		/*
312		 * Treat beacon miss like an associate failure wrt the
313		 * scan policy; this forces the entry in the scan cache
314		 * to be ignored after several tries.
315		 */
316		ieee80211_scan_assoc_fail(vap, vap->iv_bss->ni_macaddr,
317		    IEEE80211_STATUS_TIMEOUT);
318	}
319#if 0
320	ts->tdma_inuse = 0;		/* clear slot usage */
321#endif
322	ieee80211_new_state(vap, IEEE80211_S_SCAN, 0);
323}
324
325static void
326tdma_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
327	int subtype, const struct ieee80211_rx_stats *rxs, int rssi, int nf)
328{
329	struct ieee80211com *ic = ni->ni_ic;
330	struct ieee80211vap *vap = ni->ni_vap;
331	struct ieee80211_tdma_state *ts = vap->iv_tdma;
332
333	if (subtype == IEEE80211_FC0_SUBTYPE_BEACON &&
334	    (ic->ic_flags & IEEE80211_F_SCAN) == 0) {
335		struct ieee80211_frame *wh = mtod(m0, struct ieee80211_frame *);
336		struct ieee80211_scanparams scan;
337
338		/* XXX TODO: use rxstatus to determine off-channel beacons */
339		if (ieee80211_parse_beacon(ni, m0, ic->ic_curchan, &scan) != 0)
340			return;
341		if (scan.tdma == NULL) {
342			/*
343			 * TDMA stations must beacon a TDMA ie; ignore
344			 * any other station.
345			 * XXX detect overlapping bss and change channel
346			 */
347			IEEE80211_DISCARD(vap,
348			    IEEE80211_MSG_ELEMID | IEEE80211_MSG_INPUT,
349			    wh, ieee80211_mgt_subtype_name(subtype),
350			    "%s", "no TDMA ie");
351			vap->iv_stats.is_rx_mgtdiscard++;
352			return;
353		}
354		if (ni == vap->iv_bss &&
355		    !IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
356			/*
357			 * Fake up a node for this newly
358			 * discovered member of the IBSS.
359			 */
360			ni = ieee80211_add_neighbor(vap, wh, &scan);
361			if (ni == NULL) {
362				/* NB: stat kept for alloc failure */
363				return;
364			}
365		}
366		/*
367		 * Check for state updates.
368		 */
369		if (IEEE80211_ADDR_EQ(wh->i_addr3, ni->ni_bssid)) {
370			/*
371			 * Count frame now that we know it's to be processed.
372			 */
373			vap->iv_stats.is_rx_beacon++;
374			IEEE80211_NODE_STAT(ni, rx_beacons);
375			/*
376			 * Record tsf of last beacon.  NB: this must be
377			 * done before calling tdma_process_params
378			 * as deeper routines reference it.
379			 */
380			memcpy(&ni->ni_tstamp.data, scan.tstamp,
381				sizeof(ni->ni_tstamp.data));
382			/*
383			 * Count beacon frame for s/w bmiss handling.
384			 */
385			vap->iv_swbmiss_count++;
386			/*
387			 * Process tdma ie.  The contents are used to sync
388			 * the slot timing, reconfigure the bss, etc.
389			 */
390			(void) tdma_process_params(ni, scan.tdma, rssi, nf, wh);
391			return;
392		}
393		/*
394		 * NB: defer remaining work to the adhoc code; this causes
395		 *     2x parsing of the frame but should happen infrequently
396		 */
397	}
398	ts->tdma_recv_mgmt(ni, m0, subtype, rxs, rssi, nf);
399}
400
401/*
402 * Update TDMA state on receipt of a beacon frame with
403 * a TDMA information element.  The sender's identity
404 * is provided so we can track who our peer is.  If pickslot
405 * is non-zero we scan the slot allocation state in the ie
406 * to locate a free slot for our use.
407 */
408static int
409tdma_update(struct ieee80211vap *vap, const struct ieee80211_tdma_param *tdma,
410	struct ieee80211_node *ni, int pickslot)
411{
412	struct ieee80211_tdma_state *ts = vap->iv_tdma;
413	int slot, slotlen, update;
414
415	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
416	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
417
418	update = 0;
419	if (tdma->tdma_slotcnt != ts->tdma_slotcnt) {
420		if (!TDMA_SLOTCNT_VALID(tdma->tdma_slotcnt)) {
421			if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
422				printf("%s: bad slot cnt %u\n",
423				    __func__, tdma->tdma_slotcnt);
424			return 0;
425		}
426		update |= TDMA_UPDATE_SLOTCNT;
427 	}
428	slotlen = le16toh(tdma->tdma_slotlen) * 100;
429	if (slotlen != ts->tdma_slotlen) {
430		if (!TDMA_SLOTLEN_VALID(slotlen)) {
431			if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
432				printf("%s: bad slot len %u\n",
433				    __func__, slotlen);
434			return 0;
435		}
436		update |= TDMA_UPDATE_SLOTLEN;
437 	}
438	if (tdma->tdma_bintval != ts->tdma_bintval) {
439		if (!TDMA_BINTVAL_VALID(tdma->tdma_bintval)) {
440			if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
441				printf("%s: bad beacon interval %u\n",
442				    __func__, tdma->tdma_bintval);
443			return 0;
444		}
445		update |= TDMA_UPDATE_BINTVAL;
446 	}
447	slot = ts->tdma_slot;
448	if (pickslot) {
449		/*
450		 * Pick unoccupied slot.  Note we never choose slot 0.
451		 */
452		for (slot = tdma->tdma_slotcnt-1; slot > 0; slot--)
453			if (isclr(tdma->tdma_inuse, slot))
454				break;
455		if (slot <= 0) {
456			printf("%s: no free slot, slotcnt %u inuse: 0x%x\n",
457				__func__, tdma->tdma_slotcnt,
458				tdma->tdma_inuse[0]);
459			/* XXX need to do something better */
460			return 0;
461		}
462		if (slot != ts->tdma_slot)
463			update |= TDMA_UPDATE_SLOT;
464	}
465	if (ni != ts->tdma_peer) {
466		/* update everything */
467		update = TDMA_UPDATE_SLOT
468		       | TDMA_UPDATE_SLOTCNT
469		       | TDMA_UPDATE_SLOTLEN
470		       | TDMA_UPDATE_BINTVAL;
471	}
472
473	if (update) {
474		/*
475		 * New/changed parameters; update runtime state.
476		 */
477		/* XXX overwrites user parameters */
478		if (update & TDMA_UPDATE_SLOTCNT)
479			ts->tdma_slotcnt = tdma->tdma_slotcnt;
480		if (update & TDMA_UPDATE_SLOTLEN)
481			ts->tdma_slotlen = slotlen;
482		if (update & TDMA_UPDATE_SLOT)
483			ts->tdma_slot = slot;
484		if (update & TDMA_UPDATE_BINTVAL)
485			ts->tdma_bintval = tdma->tdma_bintval;
486		/* mark beacon to be updated before next xmit */
487		ieee80211_beacon_notify(vap, IEEE80211_BEACON_TDMA);
488
489		IEEE80211_DPRINTF(vap, IEEE80211_MSG_TDMA,
490		    "%s: slot %u slotcnt %u slotlen %u us bintval %u\n",
491		    __func__, ts->tdma_slot, ts->tdma_slotcnt,
492		    ts->tdma_slotlen, ts->tdma_bintval);
493	}
494	/*
495	 * Notify driver.  Note we can be called before
496	 * entering RUN state if we scanned and are
497	 * joining an existing bss.  In that case do not
498	 * call the driver because not all necessary state
499	 * has been setup.  The next beacon will dtrt.
500	 */
501	if (vap->iv_state == IEEE80211_S_RUN)
502		vap->iv_ic->ic_tdma_update(ni, tdma, update);
503	/*
504	 * Dispatch join event on first beacon from new master.
505	 */
506	if (ts->tdma_peer != ni) {
507		if (ts->tdma_peer != NULL)
508			ieee80211_notify_node_leave(vap->iv_bss);
509		ieee80211_notify_node_join(ni, 1);
510		/* NB: no reference, we just use the address */
511		ts->tdma_peer = ni;
512	}
513	return 1;
514}
515
516/*
517 * Process received TDMA parameters.
518 */
519static int
520tdma_process_params(struct ieee80211_node *ni, const u_int8_t *ie,
521	int rssi, int nf, const struct ieee80211_frame *wh)
522{
523	struct ieee80211vap *vap = ni->ni_vap;
524	struct ieee80211_tdma_state *ts = vap->iv_tdma;
525	const struct ieee80211_tdma_param *tdma =
526		(const struct ieee80211_tdma_param *) ie;
527	u_int len = ie[1];
528
529	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
530	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
531
532	if (len < sizeof(*tdma) - 2) {
533		IEEE80211_DISCARD_IE(vap,
534		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
535		    wh, "tdma", "too short, len %u", len);
536		return IEEE80211_REASON_IE_INVALID;
537	}
538	if (tdma->tdma_version != ts->tdma_version) {
539		IEEE80211_DISCARD_IE(vap,
540		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
541		    wh, "tdma", "bad version %u (ours %u)",
542		    tdma->tdma_version, ts->tdma_version);
543		return IEEE80211_REASON_IE_INVALID;
544	}
545 	/*
546	 * NB: ideally we'd check against tdma_slotcnt, but that
547	 * would require extra effort so do this easy check that
548	 * covers the work below; more stringent checks are done
549	 * before we make more extensive use of the ie contents.
550	 */
551	if (tdma->tdma_slot >= TDMA_MAXSLOTS) {
552		IEEE80211_DISCARD_IE(vap,
553		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
554		    wh, "tdma", "invalid slot %u", tdma->tdma_slot);
555		return IEEE80211_REASON_IE_INVALID;
556	}
557	/*
558	 * Can reach here while scanning, update
559	 * operational state only in RUN state.
560	 */
561	if (vap->iv_state == IEEE80211_S_RUN) {
562		if (tdma->tdma_slot != ts->tdma_slot &&
563		    isclr(ts->tdma_inuse, tdma->tdma_slot)) {
564			IEEE80211_NOTE(vap, IEEE80211_MSG_TDMA, ni,
565			    "discovered in slot %u", tdma->tdma_slot);
566			setbit(ts->tdma_inuse, tdma->tdma_slot);
567			/* XXX dispatch event only when operating as master */
568			if (ts->tdma_slot == 0)
569				ieee80211_notify_node_join(ni, 1);
570		}
571		setbit(ts->tdma_active, tdma->tdma_slot);
572		if (tdma->tdma_slot == ts->tdma_slot-1) {
573			/*
574			 * Slave tsf synchronization to station
575			 * just before us in the schedule. The driver
576			 * is responsible for copying the timestamp
577			 * of the received beacon into our beacon
578			 * frame so the sender can calculate round
579			 * trip time.  We cannot do that here because
580			 * we don't know how to update our beacon frame.
581			 */
582			(void) tdma_update(vap, tdma, ni, 0);
583			/* XXX reschedule swbmiss timer on parameter change */
584		} else if (tdma->tdma_slot == ts->tdma_slot+1) {
585			uint64_t tstamp;
586#if 0
587			uint32_t rstamp = (uint32_t) le64toh(rs->tsf);
588			int32_t rtt;
589#endif
590			/*
591			 * Use returned timstamp to calculate the
592			 * roundtrip time.
593			 */
594			memcpy(&tstamp, tdma->tdma_tstamp, 8);
595#if 0
596			/* XXX use only 15 bits of rstamp */
597			rtt = rstamp - (le64toh(tstamp) & 0x7fff);
598			if (rtt < 0)
599				rtt += 0x7fff;
600			/* XXX hack to quiet normal use */
601			IEEE80211_DPRINTF(vap, IEEE80211_MSG_DOT1X,
602			    "tdma rtt %5u [rstamp %5u tstamp %llu]\n",
603			    rtt, rstamp,
604			    (unsigned long long) le64toh(tstamp));
605#endif
606		} else if (tdma->tdma_slot == ts->tdma_slot &&
607		    le64toh(ni->ni_tstamp.tsf) > vap->iv_bss->ni_tstamp.tsf) {
608			/*
609			 * Station using the same slot as us and has
610			 * been around longer than us; we must move.
611			 * Note this can happen if stations do not
612			 * see each other while scanning.
613			 */
614			IEEE80211_DPRINTF(vap, IEEE80211_MSG_TDMA,
615			    "slot %u collision rxtsf %llu tsf %llu\n",
616			    tdma->tdma_slot,
617			    (unsigned long long) le64toh(ni->ni_tstamp.tsf),
618			    vap->iv_bss->ni_tstamp.tsf);
619			setbit(ts->tdma_inuse, tdma->tdma_slot);
620
621			(void) tdma_update(vap, tdma, ni, 1);
622		}
623	}
624	return 0;
625}
626
627int
628ieee80211_tdma_getslot(struct ieee80211vap *vap)
629{
630	struct ieee80211_tdma_state *ts = vap->iv_tdma;
631
632	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
633	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
634	return ts->tdma_slot;
635}
636
637/*
638 * Parse a TDMA ie on station join and use it to setup node state.
639 */
640void
641ieee80211_parse_tdma(struct ieee80211_node *ni, const uint8_t *ie)
642{
643	struct ieee80211vap *vap = ni->ni_vap;
644
645	if (vap->iv_caps & IEEE80211_C_TDMA) {
646		const struct ieee80211_tdma_param *tdma =
647		    (const struct ieee80211_tdma_param *)ie;
648		struct ieee80211_tdma_state *ts = vap->iv_tdma;
649		/*
650		 * Adopt TDMA configuration when joining an
651		 * existing network.
652		 */
653		setbit(ts->tdma_inuse, tdma->tdma_slot);
654		(void) tdma_update(vap, tdma, ni, 1);
655		/*
656		 * Propagate capabilities based on the local
657		 * configuration and the remote station's advertised
658		 * capabilities. In particular this permits us to
659		 * enable use of QoS to disable ACK's.
660		 */
661		if ((vap->iv_flags & IEEE80211_F_WME) &&
662		    ni->ni_ies.wme_ie != NULL)
663			ni->ni_flags |= IEEE80211_NODE_QOS;
664	}
665}
666
667#define	TDMA_OUI_BYTES		0x00, 0x03, 0x7f
668/*
669 * Add a TDMA parameters element to a frame.
670 */
671uint8_t *
672ieee80211_add_tdma(uint8_t *frm, struct ieee80211vap *vap)
673{
674#define	ADDSHORT(frm, v) do {			\
675	frm[0] = (v) & 0xff;			\
676	frm[1] = (v) >> 8;			\
677	frm += 2;				\
678} while (0)
679	static const struct ieee80211_tdma_param param = {
680		.tdma_id	= IEEE80211_ELEMID_VENDOR,
681		.tdma_len	= sizeof(struct ieee80211_tdma_param) - 2,
682		.tdma_oui	= { TDMA_OUI_BYTES },
683		.tdma_type	= TDMA_OUI_TYPE,
684		.tdma_subtype	= TDMA_SUBTYPE_PARAM,
685		.tdma_version	= TDMA_VERSION,
686	};
687	const struct ieee80211_tdma_state *ts = vap->iv_tdma;
688	uint16_t slotlen;
689
690	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
691	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
692
693	memcpy(frm, &param, sizeof(param));
694	frm += __offsetof(struct ieee80211_tdma_param, tdma_slot);
695	*frm++ = ts->tdma_slot;
696	*frm++ = ts->tdma_slotcnt;
697	/* NB: convert units to fit in 16-bits */
698	slotlen = ts->tdma_slotlen / 100;	/* 100us units */
699	ADDSHORT(frm, slotlen);
700	*frm++ = ts->tdma_bintval;
701	*frm++ = ts->tdma_inuse[0];
702	frm += 10;				/* pad+timestamp */
703	return frm;
704#undef ADDSHORT
705}
706#undef TDMA_OUI_BYTES
707
708/*
709 * Update TDMA state at TBTT.
710 */
711void
712ieee80211_tdma_update_beacon(struct ieee80211vap *vap,
713	struct ieee80211_beacon_offsets *bo)
714{
715	struct ieee80211_tdma_state *ts = vap->iv_tdma;
716
717	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
718	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
719
720	if (isset(bo->bo_flags,  IEEE80211_BEACON_TDMA)) {
721		(void) ieee80211_add_tdma(bo->bo_tdma, vap);
722		clrbit(bo->bo_flags, IEEE80211_BEACON_TDMA);
723	}
724	if (ts->tdma_slot != 0)		/* only on master */
725		return;
726	if (ts->tdma_count <= 0) {
727		/*
728		 * Time to update the mask of active/inuse stations.
729		 * We track stations that we've received a beacon
730		 * frame from and update this mask periodically.
731		 * This allows us to miss a few beacons before marking
732		 * a slot free for re-use.
733		 */
734		ts->tdma_inuse[0] = ts->tdma_active[0];
735		ts->tdma_active[0] = 0x01;
736		/* update next time 'round */
737		/* XXX use notify framework */
738		setbit(bo->bo_flags, IEEE80211_BEACON_TDMA);
739		/* NB: use s/w beacon miss threshold; may be too high */
740		ts->tdma_count = vap->iv_bmissthreshold-1;
741	} else
742		ts->tdma_count--;
743}
744
745static int
746tdma_ioctl_get80211(struct ieee80211vap *vap, struct ieee80211req *ireq)
747{
748	struct ieee80211_tdma_state *ts = vap->iv_tdma;
749
750	if ((vap->iv_caps & IEEE80211_C_TDMA) == 0)
751		return ENOSYS;
752
753	switch (ireq->i_type) {
754	case IEEE80211_IOC_TDMA_SLOT:
755		ireq->i_val = ts->tdma_slot;
756		break;
757	case IEEE80211_IOC_TDMA_SLOTCNT:
758		ireq->i_val = ts->tdma_slotcnt;
759		break;
760	case IEEE80211_IOC_TDMA_SLOTLEN:
761		ireq->i_val = ts->tdma_slotlen;
762		break;
763	case IEEE80211_IOC_TDMA_BINTERVAL:
764		ireq->i_val = ts->tdma_bintval;
765		break;
766	default:
767		return ENOSYS;
768	}
769	return 0;
770}
771IEEE80211_IOCTL_GET(tdma, tdma_ioctl_get80211);
772
773static int
774tdma_ioctl_set80211(struct ieee80211vap *vap, struct ieee80211req *ireq)
775{
776	struct ieee80211_tdma_state *ts = vap->iv_tdma;
777
778	if ((vap->iv_caps & IEEE80211_C_TDMA) == 0)
779		return ENOSYS;
780
781	switch (ireq->i_type) {
782	case IEEE80211_IOC_TDMA_SLOT:
783		if (!(0 <= ireq->i_val && ireq->i_val <= ts->tdma_slotcnt))
784			return EINVAL;
785		if (ireq->i_val != ts->tdma_slot) {
786			ts->tdma_slot = ireq->i_val;
787			goto restart;
788		}
789		break;
790	case IEEE80211_IOC_TDMA_SLOTCNT:
791		if (!TDMA_SLOTCNT_VALID(ireq->i_val))
792			return EINVAL;
793		if (ireq->i_val != ts->tdma_slotcnt) {
794			ts->tdma_slotcnt = ireq->i_val;
795			goto restart;
796		}
797		break;
798	case IEEE80211_IOC_TDMA_SLOTLEN:
799		/*
800		 * XXX
801		 * 150 insures at least 1/8 TU
802		 * 0xfffff is the max duration for bursting
803		 * (implict by way of 16-bit data type for i_val)
804		 */
805		if (!TDMA_SLOTLEN_VALID(ireq->i_val))
806			return EINVAL;
807		if (ireq->i_val != ts->tdma_slotlen) {
808			ts->tdma_slotlen = ireq->i_val;
809			goto restart;
810		}
811		break;
812	case IEEE80211_IOC_TDMA_BINTERVAL:
813		if (!TDMA_BINTVAL_VALID(ireq->i_val))
814			return EINVAL;
815		if (ireq->i_val != ts->tdma_bintval) {
816			ts->tdma_bintval = ireq->i_val;
817			goto restart;
818		}
819		break;
820	default:
821		return ENOSYS;
822	}
823	return 0;
824restart:
825	ieee80211_beacon_notify(vap, IEEE80211_BEACON_TDMA);
826	return ERESTART;
827}
828IEEE80211_IOCTL_SET(tdma, tdma_ioctl_set80211);
829
830#endif	/* IEEE80211_SUPPORT_TDMA */
831