xref: /freebsd/sys/net80211/ieee80211_tdma.c (revision 59c8e88e72633afbc47a4ace0d2170d00d51f7dc)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2007-2009 Sam Leffler, Errno Consulting
5  * Copyright (c) 2007-2009 Intel Corporation
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /*
30  * IEEE 802.11 TDMA mode support.
31  */
32 #include "opt_inet.h"
33 #include "opt_tdma.h"
34 #include "opt_wlan.h"
35 
36 #ifdef	IEEE80211_SUPPORT_TDMA
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/mbuf.h>
41 #include <sys/malloc.h>
42 #include <sys/kernel.h>
43 
44 #include <sys/socket.h>
45 #include <sys/sockio.h>
46 #include <sys/endian.h>
47 #include <sys/errno.h>
48 #include <sys/proc.h>
49 #include <sys/sysctl.h>
50 
51 #include <net/if.h>
52 #include <net/if_media.h>
53 #include <net/if_llc.h>
54 #include <net/ethernet.h>
55 
56 #include <net/bpf.h>
57 
58 #include <net80211/ieee80211_var.h>
59 #include <net80211/ieee80211_tdma.h>
60 #include <net80211/ieee80211_input.h>
61 
62 #ifndef TDMA_SLOTLEN_DEFAULT
63 #define	TDMA_SLOTLEN_DEFAULT	10*1000		/* 10ms */
64 #endif
65 #ifndef TDMA_SLOTCNT_DEFAULT
66 #define	TDMA_SLOTCNT_DEFAULT	2		/* 2x (pt-to-pt) */
67 #endif
68 #ifndef TDMA_BINTVAL_DEFAULT
69 #define	TDMA_BINTVAL_DEFAULT	5		/* 5x ~= 100TU beacon intvl */
70 #endif
71 #ifndef TDMA_TXRATE_11B_DEFAULT
72 #define	TDMA_TXRATE_11B_DEFAULT	2*11
73 #endif
74 #ifndef TDMA_TXRATE_11G_DEFAULT
75 #define	TDMA_TXRATE_11G_DEFAULT	2*24
76 #endif
77 #ifndef TDMA_TXRATE_11A_DEFAULT
78 #define	TDMA_TXRATE_11A_DEFAULT	2*24
79 #endif
80 #ifndef TDMA_TXRATE_TURBO_DEFAULT
81 #define	TDMA_TXRATE_TURBO_DEFAULT	2*24
82 #endif
83 #ifndef TDMA_TXRATE_HALF_DEFAULT
84 #define	TDMA_TXRATE_HALF_DEFAULT	2*12
85 #endif
86 #ifndef TDMA_TXRATE_QUARTER_DEFAULT
87 #define	TDMA_TXRATE_QUARTER_DEFAULT	2*6
88 #endif
89 #ifndef TDMA_TXRATE_11NA_DEFAULT
90 #define	TDMA_TXRATE_11NA_DEFAULT	(4 | IEEE80211_RATE_MCS)
91 #endif
92 #ifndef TDMA_TXRATE_11NG_DEFAULT
93 #define	TDMA_TXRATE_11NG_DEFAULT	(4 | IEEE80211_RATE_MCS)
94 #endif
95 
96 #define	TDMA_VERSION_VALID(_version) \
97 	(TDMA_VERSION_V2 <= (_version) && (_version) <= TDMA_VERSION)
98 #define	TDMA_SLOTCNT_VALID(_slotcnt) \
99 	(2 <= (_slotcnt) && (_slotcnt) <= TDMA_MAXSLOTS)
100 /* XXX magic constants */
101 #define	TDMA_SLOTLEN_VALID(_slotlen) \
102 	(2*100 <= (_slotlen) && (unsigned)(_slotlen) <= 0xfffff)
103 /* XXX probably should set a max */
104 #define	TDMA_BINTVAL_VALID(_bintval)	(1 <= (_bintval))
105 
106 /*
107  * This code is not prepared to handle more than 2 slots.
108  */
109 CTASSERT(TDMA_MAXSLOTS == 2);
110 
111 static void tdma_vdetach(struct ieee80211vap *vap);
112 static int tdma_newstate(struct ieee80211vap *, enum ieee80211_state, int);
113 static void tdma_beacon_miss(struct ieee80211vap *vap);
114 static void tdma_recv_mgmt(struct ieee80211_node *, struct mbuf *,
115 	int subtype, const struct ieee80211_rx_stats *rxs, int rssi, int nf);
116 static int tdma_update(struct ieee80211vap *vap,
117 	const struct ieee80211_tdma_param *tdma, struct ieee80211_node *ni,
118 	int pickslot);
119 static int tdma_process_params(struct ieee80211_node *ni,
120 	const u_int8_t *ie, int rssi, int nf, const struct ieee80211_frame *wh);
121 
122 static void
123 settxparms(struct ieee80211vap *vap, enum ieee80211_phymode mode, int rate)
124 {
125 	if (isclr(vap->iv_ic->ic_modecaps, mode))
126 		return;
127 
128 	vap->iv_txparms[mode].ucastrate = rate;
129 	vap->iv_txparms[mode].mcastrate = rate;
130 }
131 
132 static void
133 setackpolicy(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 
144 void
145 ieee80211_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 	settxparms(vap, IEEE80211_MODE_VHT_2GHZ, TDMA_TXRATE_11NG_DEFAULT);
180 	settxparms(vap, IEEE80211_MODE_VHT_5GHZ, TDMA_TXRATE_11NA_DEFAULT);
181 
182 	setackpolicy(vap->iv_ic, 1);	/* disable ACK's */
183 
184 	ts->tdma_opdetach = vap->iv_opdetach;
185 	vap->iv_opdetach = tdma_vdetach;
186 	ts->tdma_newstate = vap->iv_newstate;
187 	vap->iv_newstate = tdma_newstate;
188 	vap->iv_bmiss = tdma_beacon_miss;
189 	ts->tdma_recv_mgmt = vap->iv_recv_mgmt;
190 	vap->iv_recv_mgmt = tdma_recv_mgmt;
191 
192 	vap->iv_tdma = ts;
193 }
194 
195 static void
196 tdma_vdetach(struct ieee80211vap *vap)
197 {
198 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
199 
200 	if (ts == NULL) {
201 		/* NB: should not have touched any ic state */
202 		return;
203 	}
204 	ts->tdma_opdetach(vap);
205 	IEEE80211_FREE(vap->iv_tdma, M_80211_VAP);
206 	vap->iv_tdma = NULL;
207 
208 	setackpolicy(vap->iv_ic, 0);	/* enable ACK's */
209 }
210 
211 static void
212 sta_leave(void *arg, struct ieee80211_node *ni)
213 {
214 	struct ieee80211vap *vap = ni->ni_vap;
215 
216 	if (ni != vap->iv_bss)
217 		ieee80211_node_leave(ni);
218 }
219 
220 /*
221  * TDMA state machine handler.
222  */
223 static int
224 tdma_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
225 {
226 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
227 	struct ieee80211com *ic = vap->iv_ic;
228 	enum ieee80211_state ostate;
229 	int status;
230 
231 	IEEE80211_LOCK_ASSERT(ic);
232 
233 	ostate = vap->iv_state;
234 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE, "%s: %s -> %s (%d)\n",
235 	    __func__, ieee80211_state_name[ostate],
236 	    ieee80211_state_name[nstate], arg);
237 
238 	if (vap->iv_flags_ext & IEEE80211_FEXT_SWBMISS)
239 		callout_stop(&vap->iv_swbmiss);
240 	if (nstate == IEEE80211_S_SCAN &&
241 	    (ostate == IEEE80211_S_INIT || ostate == IEEE80211_S_RUN) &&
242 	    ts->tdma_slot != 0) {
243 		/*
244 		 * Override adhoc behaviour when operating as a slave;
245 		 * we need to scan even if the channel is locked.
246 		 */
247 		vap->iv_state = nstate;			/* state transition */
248 		ieee80211_cancel_scan(vap);		/* background scan */
249 		if (ostate == IEEE80211_S_RUN) {
250 			/* purge station table; entries are stale */
251 			ieee80211_iterate_nodes_vap(&ic->ic_sta, vap,
252 			    sta_leave, NULL);
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 
290 static void
291 tdma_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 
325 static void
326 tdma_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  */
408 static int
409 tdma_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  */
519 static int
520 tdma_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 
627 int
628 ieee80211_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  */
640 void
641 ieee80211_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  */
671 uint8_t *
672 ieee80211_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  */
711 void
712 ieee80211_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 
745 static int
746 tdma_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 }
771 IEEE80211_IOCTL_GET(tdma, tdma_ioctl_get80211);
772 
773 static int
774 tdma_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;
824 restart:
825 	ieee80211_beacon_notify(vap, IEEE80211_BEACON_TDMA);
826 	return ERESTART;
827 }
828 IEEE80211_IOCTL_SET(tdma, tdma_ioctl_set80211);
829 
830 #endif	/* IEEE80211_SUPPORT_TDMA */
831