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("$FreeBSD$");
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, 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 *) malloc(
153	     sizeof(struct ieee80211_tdma_state), M_80211_VAP, M_NOWAIT | M_ZERO);
154	if (ts == NULL) {
155		printf("%s: cannot allocate TDMA state block\n", __func__);
156		/* NB: fall back to adhdemo mode */
157		vap->iv_caps &= ~IEEE80211_C_TDMA;
158		return;
159	}
160	/* NB: default configuration is passive so no beacons */
161	ts->tdma_version = TDMA_VERSION;
162	ts->tdma_slotlen = TDMA_SLOTLEN_DEFAULT;
163	ts->tdma_slotcnt = TDMA_SLOTCNT_DEFAULT;
164	ts->tdma_bintval = TDMA_BINTVAL_DEFAULT;
165	ts->tdma_slot = 1;			/* passive operation */
166
167	/* setup default fixed rates */
168	settxparms(vap, IEEE80211_MODE_11A, TDMA_TXRATE_11A_DEFAULT);
169	settxparms(vap, IEEE80211_MODE_11B, TDMA_TXRATE_11B_DEFAULT);
170	settxparms(vap, IEEE80211_MODE_11G, TDMA_TXRATE_11G_DEFAULT);
171	settxparms(vap, IEEE80211_MODE_TURBO_A, TDMA_TXRATE_TURBO_DEFAULT);
172	settxparms(vap, IEEE80211_MODE_TURBO_G, TDMA_TXRATE_TURBO_DEFAULT);
173	settxparms(vap, IEEE80211_MODE_STURBO_A, TDMA_TXRATE_TURBO_DEFAULT);
174	settxparms(vap, IEEE80211_MODE_11NA, TDMA_TXRATE_11NA_DEFAULT);
175	settxparms(vap, IEEE80211_MODE_11NG, TDMA_TXRATE_11NG_DEFAULT);
176	settxparms(vap, IEEE80211_MODE_HALF, TDMA_TXRATE_HALF_DEFAULT);
177	settxparms(vap, IEEE80211_MODE_QUARTER, TDMA_TXRATE_QUARTER_DEFAULT);
178
179	setackpolicy(vap->iv_ic, 1);	/* disable ACK's */
180
181	ts->tdma_opdetach = vap->iv_opdetach;
182	vap->iv_opdetach = tdma_vdetach;
183	ts->tdma_newstate = vap->iv_newstate;
184	vap->iv_newstate = tdma_newstate;
185	vap->iv_bmiss = tdma_beacon_miss;
186	ts->tdma_recv_mgmt = vap->iv_recv_mgmt;
187	vap->iv_recv_mgmt = tdma_recv_mgmt;
188
189	vap->iv_tdma = ts;
190}
191
192static void
193tdma_vdetach(struct ieee80211vap *vap)
194{
195	struct ieee80211_tdma_state *ts = vap->iv_tdma;
196
197	if (ts == NULL) {
198		/* NB: should not have touched any ic state */
199		return;
200	}
201	ts->tdma_opdetach(vap);
202	free(vap->iv_tdma, M_80211_VAP);
203	vap->iv_tdma = NULL;
204
205	setackpolicy(vap->iv_ic, 0);	/* enable ACK's */
206}
207
208static void
209sta_leave(void *arg, struct ieee80211_node *ni)
210{
211	struct ieee80211vap *vap = arg;
212
213	if (ni->ni_vap == vap && ni != vap->iv_bss)
214		ieee80211_node_leave(ni);
215}
216
217/*
218 * TDMA state machine handler.
219 */
220static int
221tdma_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
222{
223	struct ieee80211_tdma_state *ts = vap->iv_tdma;
224	struct ieee80211com *ic = vap->iv_ic;
225	enum ieee80211_state ostate;
226	int status;
227
228	IEEE80211_LOCK_ASSERT(ic);
229
230	ostate = vap->iv_state;
231	IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE, "%s: %s -> %s (%d)\n",
232	    __func__, ieee80211_state_name[ostate],
233	    ieee80211_state_name[nstate], arg);
234
235	if (vap->iv_flags_ext & IEEE80211_FEXT_SWBMISS)
236		callout_stop(&vap->iv_swbmiss);
237	if (nstate == IEEE80211_S_SCAN &&
238	    (ostate == IEEE80211_S_INIT || ostate == IEEE80211_S_RUN) &&
239	    ts->tdma_slot != 0) {
240		/*
241		 * Override adhoc behaviour when operating as a slave;
242		 * we need to scan even if the channel is locked.
243		 */
244		vap->iv_state = nstate;			/* state transition */
245		ieee80211_cancel_scan(vap);		/* background scan */
246		if (ostate == IEEE80211_S_RUN) {
247			/* purge station table; entries are stale */
248			ieee80211_iterate_nodes(&ic->ic_sta, sta_leave, vap);
249		}
250		if (vap->iv_flags_ext & IEEE80211_FEXT_SCANREQ) {
251			ieee80211_check_scan(vap,
252			    vap->iv_scanreq_flags,
253			    vap->iv_scanreq_duration,
254			    vap->iv_scanreq_mindwell,
255			    vap->iv_scanreq_maxdwell,
256			    vap->iv_scanreq_nssid, vap->iv_scanreq_ssid);
257			vap->iv_flags_ext &= ~IEEE80211_FEXT_SCANREQ;
258		} else
259			ieee80211_check_scan_current(vap);
260		status = 0;
261	} else {
262		status = ts->tdma_newstate(vap, nstate, arg);
263	}
264	if (status == 0 &&
265	    nstate == IEEE80211_S_RUN && ostate != IEEE80211_S_RUN &&
266	    (vap->iv_flags_ext & IEEE80211_FEXT_SWBMISS) &&
267	    ts->tdma_slot != 0 &&
268	    vap->iv_des_chan == IEEE80211_CHAN_ANYC) {
269		/*
270		 * Start s/w beacon miss timer for slave devices w/o
271		 * hardware support.  Note we do this only if we're
272		 * not locked to a channel (i.e. roam to follow the
273		 * master). The 2x is a fudge for our doing this in
274		 * software.
275		 */
276		vap->iv_swbmiss_period = IEEE80211_TU_TO_TICKS(
277		    2 * vap->iv_bmissthreshold * ts->tdma_bintval *
278		    ((ts->tdma_slotcnt * ts->tdma_slotlen) / 1024));
279		vap->iv_swbmiss_count = 0;
280		callout_reset(&vap->iv_swbmiss, vap->iv_swbmiss_period,
281			ieee80211_swbmiss, vap);
282	}
283	return status;
284}
285
286static void
287tdma_beacon_miss(struct ieee80211vap *vap)
288{
289	struct ieee80211_tdma_state *ts = vap->iv_tdma;
290
291	IEEE80211_LOCK_ASSERT(vap->iv_ic);
292
293	KASSERT((vap->iv_ic->ic_flags & IEEE80211_F_SCAN) == 0, ("scanning"));
294	KASSERT(vap->iv_state == IEEE80211_S_RUN,
295	    ("wrong state %d", vap->iv_state));
296
297	IEEE80211_DPRINTF(vap,
298		IEEE80211_MSG_STATE | IEEE80211_MSG_TDMA | IEEE80211_MSG_DEBUG,
299		"beacon miss, mode %u state %s\n",
300		vap->iv_opmode, ieee80211_state_name[vap->iv_state]);
301
302	callout_stop(&vap->iv_swbmiss);
303
304	if (ts->tdma_peer != NULL) {	/* XXX? can this be null? */
305		ieee80211_notify_node_leave(vap->iv_bss);
306		ts->tdma_peer = NULL;
307		/*
308		 * Treat beacon miss like an associate failure wrt the
309		 * scan policy; this forces the entry in the scan cache
310		 * to be ignored after several tries.
311		 */
312		ieee80211_scan_assoc_fail(vap, vap->iv_bss->ni_macaddr,
313		    IEEE80211_STATUS_TIMEOUT);
314	}
315#if 0
316	ts->tdma_inuse = 0;		/* clear slot usage */
317#endif
318	ieee80211_new_state(vap, IEEE80211_S_SCAN, 0);
319}
320
321static void
322tdma_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
323	int subtype, int rssi, int nf)
324{
325	struct ieee80211com *ic = ni->ni_ic;
326	struct ieee80211vap *vap = ni->ni_vap;
327	struct ieee80211_tdma_state *ts = vap->iv_tdma;
328
329	if (subtype == IEEE80211_FC0_SUBTYPE_BEACON &&
330	    (ic->ic_flags & IEEE80211_F_SCAN) == 0) {
331		struct ieee80211_frame *wh = mtod(m0, struct ieee80211_frame *);
332		struct ieee80211_scanparams scan;
333
334		if (ieee80211_parse_beacon(ni, m0, &scan) != 0)
335			return;
336		if (scan.tdma == NULL) {
337			/*
338			 * TDMA stations must beacon a TDMA ie; ignore
339			 * any other station.
340			 * XXX detect overlapping bss and change channel
341			 */
342			IEEE80211_DISCARD(vap,
343			    IEEE80211_MSG_ELEMID | IEEE80211_MSG_INPUT,
344			    wh, ieee80211_mgt_subtype_name[subtype >>
345				IEEE80211_FC0_SUBTYPE_SHIFT],
346			    "%s", "no TDMA ie");
347			vap->iv_stats.is_rx_mgtdiscard++;
348			return;
349		}
350		if (ni == vap->iv_bss &&
351		    !IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
352			/*
353			 * Fake up a node for this newly
354			 * discovered member of the IBSS.
355			 */
356			ni = ieee80211_add_neighbor(vap, wh, &scan);
357			if (ni == NULL) {
358				/* NB: stat kept for alloc failure */
359				return;
360			}
361		}
362		/*
363		 * Check for state updates.
364		 */
365		if (IEEE80211_ADDR_EQ(wh->i_addr3, ni->ni_bssid)) {
366			/*
367			 * Count frame now that we know it's to be processed.
368			 */
369			vap->iv_stats.is_rx_beacon++;
370			IEEE80211_NODE_STAT(ni, rx_beacons);
371			/*
372			 * Record tsf of last beacon.  NB: this must be
373			 * done before calling tdma_process_params
374			 * as deeper routines reference it.
375			 */
376			memcpy(&ni->ni_tstamp.data, scan.tstamp,
377				sizeof(ni->ni_tstamp.data));
378			/*
379			 * Count beacon frame for s/w bmiss handling.
380			 */
381			vap->iv_swbmiss_count++;
382			/*
383			 * Process tdma ie.  The contents are used to sync
384			 * the slot timing, reconfigure the bss, etc.
385			 */
386			(void) tdma_process_params(ni, scan.tdma, rssi, nf, wh);
387			return;
388		}
389		/*
390		 * NB: defer remaining work to the adhoc code; this causes
391		 *     2x parsing of the frame but should happen infrequently
392		 */
393	}
394	ts->tdma_recv_mgmt(ni, m0, subtype, rssi, nf);
395}
396
397/*
398 * Update TDMA state on receipt of a beacon frame with
399 * a TDMA information element.  The sender's identity
400 * is provided so we can track who our peer is.  If pickslot
401 * is non-zero we scan the slot allocation state in the ie
402 * to locate a free slot for our use.
403 */
404static int
405tdma_update(struct ieee80211vap *vap, const struct ieee80211_tdma_param *tdma,
406	struct ieee80211_node *ni, int pickslot)
407{
408	struct ieee80211_tdma_state *ts = vap->iv_tdma;
409	int slot, slotlen, update;
410
411	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
412	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
413
414	update = 0;
415	if (tdma->tdma_slotcnt != ts->tdma_slotcnt) {
416		if (!TDMA_SLOTCNT_VALID(tdma->tdma_slotcnt)) {
417			if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
418				printf("%s: bad slot cnt %u\n",
419				    __func__, tdma->tdma_slotcnt);
420			return 0;
421		}
422		update |= TDMA_UPDATE_SLOTCNT;
423 	}
424	slotlen = le16toh(tdma->tdma_slotlen) * 100;
425	if (slotlen != ts->tdma_slotlen) {
426		if (!TDMA_SLOTLEN_VALID(slotlen)) {
427			if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
428				printf("%s: bad slot len %u\n",
429				    __func__, slotlen);
430			return 0;
431		}
432		update |= TDMA_UPDATE_SLOTLEN;
433 	}
434	if (tdma->tdma_bintval != ts->tdma_bintval) {
435		if (!TDMA_BINTVAL_VALID(tdma->tdma_bintval)) {
436			if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
437				printf("%s: bad beacon interval %u\n",
438				    __func__, tdma->tdma_bintval);
439			return 0;
440		}
441		update |= TDMA_UPDATE_BINTVAL;
442 	}
443	slot = ts->tdma_slot;
444	if (pickslot) {
445		/*
446		 * Pick unoccupied slot.  Note we never choose slot 0.
447		 */
448		for (slot = tdma->tdma_slotcnt-1; slot > 0; slot--)
449			if (isclr(tdma->tdma_inuse, slot))
450				break;
451		if (slot <= 0) {
452			printf("%s: no free slot, slotcnt %u inuse: 0x%x\n",
453				__func__, tdma->tdma_slotcnt,
454				tdma->tdma_inuse[0]);
455			/* XXX need to do something better */
456			return 0;
457		}
458		if (slot != ts->tdma_slot)
459			update |= TDMA_UPDATE_SLOT;
460	}
461	if (ni != ts->tdma_peer) {
462		/* update everything */
463		update = TDMA_UPDATE_SLOT
464		       | TDMA_UPDATE_SLOTCNT
465		       | TDMA_UPDATE_SLOTLEN
466		       | TDMA_UPDATE_BINTVAL;
467	}
468
469	if (update) {
470		/*
471		 * New/changed parameters; update runtime state.
472		 */
473		/* XXX overwrites user parameters */
474		if (update & TDMA_UPDATE_SLOTCNT)
475			ts->tdma_slotcnt = tdma->tdma_slotcnt;
476		if (update & TDMA_UPDATE_SLOTLEN)
477			ts->tdma_slotlen = slotlen;
478		if (update & TDMA_UPDATE_SLOT)
479			ts->tdma_slot = slot;
480		if (update & TDMA_UPDATE_BINTVAL)
481			ts->tdma_bintval = tdma->tdma_bintval;
482		/* mark beacon to be updated before next xmit */
483		ieee80211_beacon_notify(vap, IEEE80211_BEACON_TDMA);
484
485		IEEE80211_DPRINTF(vap, IEEE80211_MSG_TDMA,
486		    "%s: slot %u slotcnt %u slotlen %u us bintval %u\n",
487		    __func__, ts->tdma_slot, ts->tdma_slotcnt,
488		    ts->tdma_slotlen, ts->tdma_bintval);
489	}
490	/*
491	 * Notify driver.  Note we can be called before
492	 * entering RUN state if we scanned and are
493	 * joining an existing bss.  In that case do not
494	 * call the driver because not all necessary state
495	 * has been setup.  The next beacon will dtrt.
496	 */
497	if (vap->iv_state == IEEE80211_S_RUN)
498		vap->iv_ic->ic_tdma_update(ni, tdma, update);
499	/*
500	 * Dispatch join event on first beacon from new master.
501	 */
502	if (ts->tdma_peer != ni) {
503		if (ts->tdma_peer != NULL)
504			ieee80211_notify_node_leave(vap->iv_bss);
505		ieee80211_notify_node_join(ni, 1);
506		/* NB: no reference, we just use the address */
507		ts->tdma_peer = ni;
508	}
509	return 1;
510}
511
512/*
513 * Process received TDMA parameters.
514 */
515static int
516tdma_process_params(struct ieee80211_node *ni, const u_int8_t *ie,
517	int rssi, int nf, const struct ieee80211_frame *wh)
518{
519	struct ieee80211vap *vap = ni->ni_vap;
520	struct ieee80211_tdma_state *ts = vap->iv_tdma;
521	const struct ieee80211_tdma_param *tdma =
522		(const struct ieee80211_tdma_param *) ie;
523	u_int len = ie[1];
524
525	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
526	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
527
528	if (len < sizeof(*tdma) - 2) {
529		IEEE80211_DISCARD_IE(vap,
530		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
531		    wh, "tdma", "too short, len %u", len);
532		return IEEE80211_REASON_IE_INVALID;
533	}
534	if (tdma->tdma_version != ts->tdma_version) {
535		IEEE80211_DISCARD_IE(vap,
536		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
537		    wh, "tdma", "bad version %u (ours %u)",
538		    tdma->tdma_version, ts->tdma_version);
539		return IEEE80211_REASON_IE_INVALID;
540	}
541 	/*
542	 * NB: ideally we'd check against tdma_slotcnt, but that
543	 * would require extra effort so do this easy check that
544	 * covers the work below; more stringent checks are done
545	 * before we make more extensive use of the ie contents.
546	 */
547	if (tdma->tdma_slot >= TDMA_MAXSLOTS) {
548		IEEE80211_DISCARD_IE(vap,
549		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
550		    wh, "tdma", "invalid slot %u", tdma->tdma_slot);
551		return IEEE80211_REASON_IE_INVALID;
552	}
553	/*
554	 * Can reach here while scanning, update
555	 * operational state only in RUN state.
556	 */
557	if (vap->iv_state == IEEE80211_S_RUN) {
558		if (tdma->tdma_slot != ts->tdma_slot &&
559		    isclr(ts->tdma_inuse, tdma->tdma_slot)) {
560			IEEE80211_NOTE(vap, IEEE80211_MSG_TDMA, ni,
561			    "discovered in slot %u", tdma->tdma_slot);
562			setbit(ts->tdma_inuse, tdma->tdma_slot);
563			/* XXX dispatch event only when operating as master */
564			if (ts->tdma_slot == 0)
565				ieee80211_notify_node_join(ni, 1);
566		}
567		setbit(ts->tdma_active, tdma->tdma_slot);
568		if (tdma->tdma_slot == ts->tdma_slot-1) {
569			/*
570			 * Slave tsf synchronization to station
571			 * just before us in the schedule. The driver
572			 * is responsible for copying the timestamp
573			 * of the received beacon into our beacon
574			 * frame so the sender can calculate round
575			 * trip time.  We cannot do that here because
576			 * we don't know how to update our beacon frame.
577			 */
578			(void) tdma_update(vap, tdma, ni, 0);
579			/* XXX reschedule swbmiss timer on parameter change */
580		} else if (tdma->tdma_slot == ts->tdma_slot+1) {
581			uint64_t tstamp;
582#if 0
583			uint32_t rstamp = (uint32_t) le64toh(rs->tsf);
584			int32_t rtt;
585#endif
586			/*
587			 * Use returned timstamp to calculate the
588			 * roundtrip time.
589			 */
590			memcpy(&tstamp, tdma->tdma_tstamp, 8);
591#if 0
592			/* XXX use only 15 bits of rstamp */
593			rtt = rstamp - (le64toh(tstamp) & 0x7fff);
594			if (rtt < 0)
595				rtt += 0x7fff;
596			/* XXX hack to quiet normal use */
597			IEEE80211_DPRINTF(vap, IEEE80211_MSG_DOT1X,
598			    "tdma rtt %5u [rstamp %5u tstamp %llu]\n",
599			    rtt, rstamp,
600			    (unsigned long long) le64toh(tstamp));
601#endif
602		} else if (tdma->tdma_slot == ts->tdma_slot &&
603		    le64toh(ni->ni_tstamp.tsf) > vap->iv_bss->ni_tstamp.tsf) {
604			/*
605			 * Station using the same slot as us and has
606			 * been around longer than us; we must move.
607			 * Note this can happen if stations do not
608			 * see each other while scanning.
609			 */
610			IEEE80211_DPRINTF(vap, IEEE80211_MSG_TDMA,
611			    "slot %u collision rxtsf %llu tsf %llu\n",
612			    tdma->tdma_slot,
613			    (unsigned long long) le64toh(ni->ni_tstamp.tsf),
614			    vap->iv_bss->ni_tstamp.tsf);
615			setbit(ts->tdma_inuse, tdma->tdma_slot);
616
617			(void) tdma_update(vap, tdma, ni, 1);
618		}
619	}
620	return 0;
621}
622
623int
624ieee80211_tdma_getslot(struct ieee80211vap *vap)
625{
626	struct ieee80211_tdma_state *ts = vap->iv_tdma;
627
628	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
629	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
630	return ts->tdma_slot;
631}
632
633/*
634 * Parse a TDMA ie on station join and use it to setup node state.
635 */
636void
637ieee80211_parse_tdma(struct ieee80211_node *ni, const uint8_t *ie)
638{
639	struct ieee80211vap *vap = ni->ni_vap;
640
641	if (vap->iv_caps & IEEE80211_C_TDMA) {
642		const struct ieee80211_tdma_param *tdma =
643		    (const struct ieee80211_tdma_param *)ie;
644		struct ieee80211_tdma_state *ts = vap->iv_tdma;
645		/*
646		 * Adopt TDMA configuration when joining an
647		 * existing network.
648		 */
649		setbit(ts->tdma_inuse, tdma->tdma_slot);
650		(void) tdma_update(vap, tdma, ni, 1);
651		/*
652		 * Propagate capabilities based on the local
653		 * configuration and the remote station's advertised
654		 * capabilities. In particular this permits us to
655		 * enable use of QoS to disable ACK's.
656		 */
657		if ((vap->iv_flags & IEEE80211_F_WME) &&
658		    ni->ni_ies.wme_ie != NULL)
659			ni->ni_flags |= IEEE80211_NODE_QOS;
660	}
661}
662
663#define	TDMA_OUI_BYTES		0x00, 0x03, 0x7f
664/*
665 * Add a TDMA parameters element to a frame.
666 */
667uint8_t *
668ieee80211_add_tdma(uint8_t *frm, struct ieee80211vap *vap)
669{
670#define	ADDSHORT(frm, v) do {			\
671	frm[0] = (v) & 0xff;			\
672	frm[1] = (v) >> 8;			\
673	frm += 2;				\
674} while (0)
675	static const struct ieee80211_tdma_param param = {
676		.tdma_id	= IEEE80211_ELEMID_VENDOR,
677		.tdma_len	= sizeof(struct ieee80211_tdma_param) - 2,
678		.tdma_oui	= { TDMA_OUI_BYTES },
679		.tdma_type	= TDMA_OUI_TYPE,
680		.tdma_subtype	= TDMA_SUBTYPE_PARAM,
681		.tdma_version	= TDMA_VERSION,
682	};
683	const struct ieee80211_tdma_state *ts = vap->iv_tdma;
684	uint16_t slotlen;
685
686	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
687	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
688
689	memcpy(frm, &param, sizeof(param));
690	frm += __offsetof(struct ieee80211_tdma_param, tdma_slot);
691	*frm++ = ts->tdma_slot;
692	*frm++ = ts->tdma_slotcnt;
693	/* NB: convert units to fit in 16-bits */
694	slotlen = ts->tdma_slotlen / 100;	/* 100us units */
695	ADDSHORT(frm, slotlen);
696	*frm++ = ts->tdma_bintval;
697	*frm++ = ts->tdma_inuse[0];
698	frm += 10;				/* pad+timestamp */
699	return frm;
700#undef ADDSHORT
701}
702#undef TDMA_OUI_BYTES
703
704/*
705 * Update TDMA state at TBTT.
706 */
707void
708ieee80211_tdma_update_beacon(struct ieee80211vap *vap,
709	struct ieee80211_beacon_offsets *bo)
710{
711	struct ieee80211_tdma_state *ts = vap->iv_tdma;
712
713	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
714	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
715
716	if (isset(bo->bo_flags,  IEEE80211_BEACON_TDMA)) {
717		(void) ieee80211_add_tdma(bo->bo_tdma, vap);
718		clrbit(bo->bo_flags, IEEE80211_BEACON_TDMA);
719	}
720	if (ts->tdma_slot != 0)		/* only on master */
721		return;
722	if (ts->tdma_count <= 0) {
723		/*
724		 * Time to update the mask of active/inuse stations.
725		 * We track stations that we've received a beacon
726		 * frame from and update this mask periodically.
727		 * This allows us to miss a few beacons before marking
728		 * a slot free for re-use.
729		 */
730		ts->tdma_inuse[0] = ts->tdma_active[0];
731		ts->tdma_active[0] = 0x01;
732		/* update next time 'round */
733		/* XXX use notify framework */
734		setbit(bo->bo_flags, IEEE80211_BEACON_TDMA);
735		/* NB: use s/w beacon miss threshold; may be too high */
736		ts->tdma_count = vap->iv_bmissthreshold-1;
737	} else
738		ts->tdma_count--;
739}
740
741static int
742tdma_ioctl_get80211(struct ieee80211vap *vap, struct ieee80211req *ireq)
743{
744	struct ieee80211_tdma_state *ts = vap->iv_tdma;
745
746	if ((vap->iv_caps & IEEE80211_C_TDMA) == 0)
747		return ENOSYS;
748
749	switch (ireq->i_type) {
750	case IEEE80211_IOC_TDMA_SLOT:
751		ireq->i_val = ts->tdma_slot;
752		break;
753	case IEEE80211_IOC_TDMA_SLOTCNT:
754		ireq->i_val = ts->tdma_slotcnt;
755		break;
756	case IEEE80211_IOC_TDMA_SLOTLEN:
757		ireq->i_val = ts->tdma_slotlen;
758		break;
759	case IEEE80211_IOC_TDMA_BINTERVAL:
760		ireq->i_val = ts->tdma_bintval;
761		break;
762	default:
763		return ENOSYS;
764	}
765	return 0;
766}
767IEEE80211_IOCTL_GET(tdma, tdma_ioctl_get80211);
768
769static int
770tdma_ioctl_set80211(struct ieee80211vap *vap, struct ieee80211req *ireq)
771{
772	struct ieee80211_tdma_state *ts = vap->iv_tdma;
773
774	if ((vap->iv_caps & IEEE80211_C_TDMA) == 0)
775		return ENOSYS;
776
777	switch (ireq->i_type) {
778	case IEEE80211_IOC_TDMA_SLOT:
779		if (!(0 <= ireq->i_val && ireq->i_val <= ts->tdma_slotcnt))
780			return EINVAL;
781		if (ireq->i_val != ts->tdma_slot) {
782			ts->tdma_slot = ireq->i_val;
783			goto restart;
784		}
785		break;
786	case IEEE80211_IOC_TDMA_SLOTCNT:
787		if (!TDMA_SLOTCNT_VALID(ireq->i_val))
788			return EINVAL;
789		if (ireq->i_val != ts->tdma_slotcnt) {
790			ts->tdma_slotcnt = ireq->i_val;
791			goto restart;
792		}
793		break;
794	case IEEE80211_IOC_TDMA_SLOTLEN:
795		/*
796		 * XXX
797		 * 150 insures at least 1/8 TU
798		 * 0xfffff is the max duration for bursting
799		 * (implict by way of 16-bit data type for i_val)
800		 */
801		if (!TDMA_SLOTLEN_VALID(ireq->i_val))
802			return EINVAL;
803		if (ireq->i_val != ts->tdma_slotlen) {
804			ts->tdma_slotlen = ireq->i_val;
805			goto restart;
806		}
807		break;
808	case IEEE80211_IOC_TDMA_BINTERVAL:
809		if (!TDMA_BINTVAL_VALID(ireq->i_val))
810			return EINVAL;
811		if (ireq->i_val != ts->tdma_bintval) {
812			ts->tdma_bintval = ireq->i_val;
813			goto restart;
814		}
815		break;
816	default:
817		return ENOSYS;
818	}
819	return 0;
820restart:
821	ieee80211_beacon_notify(vap, IEEE80211_BEACON_TDMA);
822	return ERESTART;
823}
824IEEE80211_IOCTL_SET(tdma, tdma_ioctl_set80211);
825
826#endif	/* IEEE80211_SUPPORT_TDMA */
827