xref: /freebsd/sys/net80211/ieee80211_tdma.c (revision 22cf89c938886d14f5796fc49f9f020c23ea8eaf)
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 #include <sys/cdefs.h>
30 #ifdef __FreeBSD__
31 #endif
32 
33 /*
34  * IEEE 802.11 TDMA mode support.
35  */
36 #include "opt_inet.h"
37 #include "opt_tdma.h"
38 #include "opt_wlan.h"
39 
40 #ifdef	IEEE80211_SUPPORT_TDMA
41 
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/mbuf.h>
45 #include <sys/malloc.h>
46 #include <sys/kernel.h>
47 
48 #include <sys/socket.h>
49 #include <sys/sockio.h>
50 #include <sys/endian.h>
51 #include <sys/errno.h>
52 #include <sys/proc.h>
53 #include <sys/sysctl.h>
54 
55 #include <net/if.h>
56 #include <net/if_media.h>
57 #include <net/if_llc.h>
58 #include <net/ethernet.h>
59 
60 #include <net/bpf.h>
61 
62 #include <net80211/ieee80211_var.h>
63 #include <net80211/ieee80211_tdma.h>
64 #include <net80211/ieee80211_input.h>
65 
66 #ifndef TDMA_SLOTLEN_DEFAULT
67 #define	TDMA_SLOTLEN_DEFAULT	10*1000		/* 10ms */
68 #endif
69 #ifndef TDMA_SLOTCNT_DEFAULT
70 #define	TDMA_SLOTCNT_DEFAULT	2		/* 2x (pt-to-pt) */
71 #endif
72 #ifndef TDMA_BINTVAL_DEFAULT
73 #define	TDMA_BINTVAL_DEFAULT	5		/* 5x ~= 100TU beacon intvl */
74 #endif
75 #ifndef TDMA_TXRATE_11B_DEFAULT
76 #define	TDMA_TXRATE_11B_DEFAULT	2*11
77 #endif
78 #ifndef TDMA_TXRATE_11G_DEFAULT
79 #define	TDMA_TXRATE_11G_DEFAULT	2*24
80 #endif
81 #ifndef TDMA_TXRATE_11A_DEFAULT
82 #define	TDMA_TXRATE_11A_DEFAULT	2*24
83 #endif
84 #ifndef TDMA_TXRATE_TURBO_DEFAULT
85 #define	TDMA_TXRATE_TURBO_DEFAULT	2*24
86 #endif
87 #ifndef TDMA_TXRATE_HALF_DEFAULT
88 #define	TDMA_TXRATE_HALF_DEFAULT	2*12
89 #endif
90 #ifndef TDMA_TXRATE_QUARTER_DEFAULT
91 #define	TDMA_TXRATE_QUARTER_DEFAULT	2*6
92 #endif
93 #ifndef TDMA_TXRATE_11NA_DEFAULT
94 #define	TDMA_TXRATE_11NA_DEFAULT	(4 | IEEE80211_RATE_MCS)
95 #endif
96 #ifndef TDMA_TXRATE_11NG_DEFAULT
97 #define	TDMA_TXRATE_11NG_DEFAULT	(4 | IEEE80211_RATE_MCS)
98 #endif
99 
100 #define	TDMA_VERSION_VALID(_version) \
101 	(TDMA_VERSION_V2 <= (_version) && (_version) <= TDMA_VERSION)
102 #define	TDMA_SLOTCNT_VALID(_slotcnt) \
103 	(2 <= (_slotcnt) && (_slotcnt) <= TDMA_MAXSLOTS)
104 /* XXX magic constants */
105 #define	TDMA_SLOTLEN_VALID(_slotlen) \
106 	(2*100 <= (_slotlen) && (unsigned)(_slotlen) <= 0xfffff)
107 /* XXX probably should set a max */
108 #define	TDMA_BINTVAL_VALID(_bintval)	(1 <= (_bintval))
109 
110 /*
111  * This code is not prepared to handle more than 2 slots.
112  */
113 CTASSERT(TDMA_MAXSLOTS == 2);
114 
115 static void tdma_vdetach(struct ieee80211vap *vap);
116 static int tdma_newstate(struct ieee80211vap *, enum ieee80211_state, int);
117 static void tdma_beacon_miss(struct ieee80211vap *vap);
118 static void tdma_recv_mgmt(struct ieee80211_node *, struct mbuf *,
119 	int subtype, const struct ieee80211_rx_stats *rxs, int rssi, int nf);
120 static int tdma_update(struct ieee80211vap *vap,
121 	const struct ieee80211_tdma_param *tdma, struct ieee80211_node *ni,
122 	int pickslot);
123 static int tdma_process_params(struct ieee80211_node *ni,
124 	const u_int8_t *ie, int rssi, int nf, const struct ieee80211_frame *wh);
125 
126 static void
127 settxparms(struct ieee80211vap *vap, enum ieee80211_phymode mode, int rate)
128 {
129 	if (isclr(vap->iv_ic->ic_modecaps, mode))
130 		return;
131 
132 	vap->iv_txparms[mode].ucastrate = rate;
133 	vap->iv_txparms[mode].mcastrate = rate;
134 }
135 
136 static void
137 setackpolicy(struct ieee80211com *ic, int noack)
138 {
139 	struct ieee80211_wme_state *wme = &ic->ic_wme;
140 	int ac;
141 
142 	for (ac = 0; ac < WME_NUM_AC; ac++) {
143 		wme->wme_chanParams.cap_wmeParams[ac].wmep_noackPolicy = noack;
144 		wme->wme_wmeChanParams.cap_wmeParams[ac].wmep_noackPolicy = noack;
145 	}
146 }
147 
148 void
149 ieee80211_tdma_vattach(struct ieee80211vap *vap)
150 {
151 	struct ieee80211_tdma_state *ts;
152 
153 	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
154 	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
155 
156 	ts = (struct ieee80211_tdma_state *) IEEE80211_MALLOC(
157 	     sizeof(struct ieee80211_tdma_state), M_80211_VAP,
158 	     IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
159 	if (ts == NULL) {
160 		printf("%s: cannot allocate TDMA state block\n", __func__);
161 		/* NB: fall back to adhdemo mode */
162 		vap->iv_caps &= ~IEEE80211_C_TDMA;
163 		return;
164 	}
165 	/* NB: default configuration is passive so no beacons */
166 	ts->tdma_version = TDMA_VERSION;
167 	ts->tdma_slotlen = TDMA_SLOTLEN_DEFAULT;
168 	ts->tdma_slotcnt = TDMA_SLOTCNT_DEFAULT;
169 	ts->tdma_bintval = TDMA_BINTVAL_DEFAULT;
170 	ts->tdma_slot = 1;			/* passive operation */
171 
172 	/* setup default fixed rates */
173 	settxparms(vap, IEEE80211_MODE_11A, TDMA_TXRATE_11A_DEFAULT);
174 	settxparms(vap, IEEE80211_MODE_11B, TDMA_TXRATE_11B_DEFAULT);
175 	settxparms(vap, IEEE80211_MODE_11G, TDMA_TXRATE_11G_DEFAULT);
176 	settxparms(vap, IEEE80211_MODE_TURBO_A, TDMA_TXRATE_TURBO_DEFAULT);
177 	settxparms(vap, IEEE80211_MODE_TURBO_G, TDMA_TXRATE_TURBO_DEFAULT);
178 	settxparms(vap, IEEE80211_MODE_STURBO_A, TDMA_TXRATE_TURBO_DEFAULT);
179 	settxparms(vap, IEEE80211_MODE_11NA, TDMA_TXRATE_11NA_DEFAULT);
180 	settxparms(vap, IEEE80211_MODE_11NG, TDMA_TXRATE_11NG_DEFAULT);
181 	settxparms(vap, IEEE80211_MODE_HALF, TDMA_TXRATE_HALF_DEFAULT);
182 	settxparms(vap, IEEE80211_MODE_QUARTER, TDMA_TXRATE_QUARTER_DEFAULT);
183 	settxparms(vap, IEEE80211_MODE_VHT_2GHZ, TDMA_TXRATE_11NG_DEFAULT);
184 	settxparms(vap, IEEE80211_MODE_VHT_5GHZ, TDMA_TXRATE_11NA_DEFAULT);
185 
186 	setackpolicy(vap->iv_ic, 1);	/* disable ACK's */
187 
188 	ts->tdma_opdetach = vap->iv_opdetach;
189 	vap->iv_opdetach = tdma_vdetach;
190 	ts->tdma_newstate = vap->iv_newstate;
191 	vap->iv_newstate = tdma_newstate;
192 	vap->iv_bmiss = tdma_beacon_miss;
193 	ts->tdma_recv_mgmt = vap->iv_recv_mgmt;
194 	vap->iv_recv_mgmt = tdma_recv_mgmt;
195 
196 	vap->iv_tdma = ts;
197 }
198 
199 static void
200 tdma_vdetach(struct ieee80211vap *vap)
201 {
202 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
203 
204 	if (ts == NULL) {
205 		/* NB: should not have touched any ic state */
206 		return;
207 	}
208 	ts->tdma_opdetach(vap);
209 	IEEE80211_FREE(vap->iv_tdma, M_80211_VAP);
210 	vap->iv_tdma = NULL;
211 
212 	setackpolicy(vap->iv_ic, 0);	/* enable ACK's */
213 }
214 
215 static void
216 sta_leave(void *arg, struct ieee80211_node *ni)
217 {
218 	struct ieee80211vap *vap = ni->ni_vap;
219 
220 	if (ni != vap->iv_bss)
221 		ieee80211_node_leave(ni);
222 }
223 
224 /*
225  * TDMA state machine handler.
226  */
227 static int
228 tdma_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
229 {
230 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
231 	struct ieee80211com *ic = vap->iv_ic;
232 	enum ieee80211_state ostate;
233 	int status;
234 
235 	IEEE80211_LOCK_ASSERT(ic);
236 
237 	ostate = vap->iv_state;
238 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE, "%s: %s -> %s (%d)\n",
239 	    __func__, ieee80211_state_name[ostate],
240 	    ieee80211_state_name[nstate], arg);
241 
242 	if (vap->iv_flags_ext & IEEE80211_FEXT_SWBMISS)
243 		callout_stop(&vap->iv_swbmiss);
244 	if (nstate == IEEE80211_S_SCAN &&
245 	    (ostate == IEEE80211_S_INIT || ostate == IEEE80211_S_RUN) &&
246 	    ts->tdma_slot != 0) {
247 		/*
248 		 * Override adhoc behaviour when operating as a slave;
249 		 * we need to scan even if the channel is locked.
250 		 */
251 		vap->iv_state = nstate;			/* state transition */
252 		ieee80211_cancel_scan(vap);		/* background scan */
253 		if (ostate == IEEE80211_S_RUN) {
254 			/* purge station table; entries are stale */
255 			ieee80211_iterate_nodes_vap(&ic->ic_sta, vap,
256 			    sta_leave, NULL);
257 		}
258 		if (vap->iv_flags_ext & IEEE80211_FEXT_SCANREQ) {
259 			ieee80211_check_scan(vap,
260 			    vap->iv_scanreq_flags,
261 			    vap->iv_scanreq_duration,
262 			    vap->iv_scanreq_mindwell,
263 			    vap->iv_scanreq_maxdwell,
264 			    vap->iv_scanreq_nssid, vap->iv_scanreq_ssid);
265 			vap->iv_flags_ext &= ~IEEE80211_FEXT_SCANREQ;
266 		} else
267 			ieee80211_check_scan_current(vap);
268 		status = 0;
269 	} else {
270 		status = ts->tdma_newstate(vap, nstate, arg);
271 	}
272 	if (status == 0 &&
273 	    nstate == IEEE80211_S_RUN && ostate != IEEE80211_S_RUN &&
274 	    (vap->iv_flags_ext & IEEE80211_FEXT_SWBMISS) &&
275 	    ts->tdma_slot != 0 &&
276 	    vap->iv_des_chan == IEEE80211_CHAN_ANYC) {
277 		/*
278 		 * Start s/w beacon miss timer for slave devices w/o
279 		 * hardware support.  Note we do this only if we're
280 		 * not locked to a channel (i.e. roam to follow the
281 		 * master). The 2x is a fudge for our doing this in
282 		 * software.
283 		 */
284 		vap->iv_swbmiss_period = IEEE80211_TU_TO_TICKS(
285 		    2 * vap->iv_bmissthreshold * ts->tdma_bintval *
286 		    ((ts->tdma_slotcnt * ts->tdma_slotlen) / 1024));
287 		vap->iv_swbmiss_count = 0;
288 		callout_reset(&vap->iv_swbmiss, vap->iv_swbmiss_period,
289 			ieee80211_swbmiss, vap);
290 	}
291 	return status;
292 }
293 
294 static void
295 tdma_beacon_miss(struct ieee80211vap *vap)
296 {
297 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
298 
299 	IEEE80211_LOCK_ASSERT(vap->iv_ic);
300 
301 	KASSERT((vap->iv_ic->ic_flags & IEEE80211_F_SCAN) == 0, ("scanning"));
302 	KASSERT(vap->iv_state == IEEE80211_S_RUN,
303 	    ("wrong state %d", vap->iv_state));
304 
305 	IEEE80211_DPRINTF(vap,
306 		IEEE80211_MSG_STATE | IEEE80211_MSG_TDMA | IEEE80211_MSG_DEBUG,
307 		"beacon miss, mode %u state %s\n",
308 		vap->iv_opmode, ieee80211_state_name[vap->iv_state]);
309 
310 	callout_stop(&vap->iv_swbmiss);
311 
312 	if (ts->tdma_peer != NULL) {	/* XXX? can this be null? */
313 		ieee80211_notify_node_leave(vap->iv_bss);
314 		ts->tdma_peer = NULL;
315 		/*
316 		 * Treat beacon miss like an associate failure wrt the
317 		 * scan policy; this forces the entry in the scan cache
318 		 * to be ignored after several tries.
319 		 */
320 		ieee80211_scan_assoc_fail(vap, vap->iv_bss->ni_macaddr,
321 		    IEEE80211_STATUS_TIMEOUT);
322 	}
323 #if 0
324 	ts->tdma_inuse = 0;		/* clear slot usage */
325 #endif
326 	ieee80211_new_state(vap, IEEE80211_S_SCAN, 0);
327 }
328 
329 static void
330 tdma_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
331 	int subtype, const struct ieee80211_rx_stats *rxs, int rssi, int nf)
332 {
333 	struct ieee80211com *ic = ni->ni_ic;
334 	struct ieee80211vap *vap = ni->ni_vap;
335 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
336 
337 	if (subtype == IEEE80211_FC0_SUBTYPE_BEACON &&
338 	    (ic->ic_flags & IEEE80211_F_SCAN) == 0) {
339 		struct ieee80211_frame *wh = mtod(m0, struct ieee80211_frame *);
340 		struct ieee80211_scanparams scan;
341 
342 		/* XXX TODO: use rxstatus to determine off-channel beacons */
343 		if (ieee80211_parse_beacon(ni, m0, ic->ic_curchan, &scan) != 0)
344 			return;
345 		if (scan.tdma == NULL) {
346 			/*
347 			 * TDMA stations must beacon a TDMA ie; ignore
348 			 * any other station.
349 			 * XXX detect overlapping bss and change channel
350 			 */
351 			IEEE80211_DISCARD(vap,
352 			    IEEE80211_MSG_ELEMID | IEEE80211_MSG_INPUT,
353 			    wh, ieee80211_mgt_subtype_name(subtype),
354 			    "%s", "no TDMA ie");
355 			vap->iv_stats.is_rx_mgtdiscard++;
356 			return;
357 		}
358 		if (ni == vap->iv_bss &&
359 		    !IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
360 			/*
361 			 * Fake up a node for this newly
362 			 * discovered member of the IBSS.
363 			 */
364 			ni = ieee80211_add_neighbor(vap, wh, &scan);
365 			if (ni == NULL) {
366 				/* NB: stat kept for alloc failure */
367 				return;
368 			}
369 		}
370 		/*
371 		 * Check for state updates.
372 		 */
373 		if (IEEE80211_ADDR_EQ(wh->i_addr3, ni->ni_bssid)) {
374 			/*
375 			 * Count frame now that we know it's to be processed.
376 			 */
377 			vap->iv_stats.is_rx_beacon++;
378 			IEEE80211_NODE_STAT(ni, rx_beacons);
379 			/*
380 			 * Record tsf of last beacon.  NB: this must be
381 			 * done before calling tdma_process_params
382 			 * as deeper routines reference it.
383 			 */
384 			memcpy(&ni->ni_tstamp.data, scan.tstamp,
385 				sizeof(ni->ni_tstamp.data));
386 			/*
387 			 * Count beacon frame for s/w bmiss handling.
388 			 */
389 			vap->iv_swbmiss_count++;
390 			/*
391 			 * Process tdma ie.  The contents are used to sync
392 			 * the slot timing, reconfigure the bss, etc.
393 			 */
394 			(void) tdma_process_params(ni, scan.tdma, rssi, nf, wh);
395 			return;
396 		}
397 		/*
398 		 * NB: defer remaining work to the adhoc code; this causes
399 		 *     2x parsing of the frame but should happen infrequently
400 		 */
401 	}
402 	ts->tdma_recv_mgmt(ni, m0, subtype, rxs, rssi, nf);
403 }
404 
405 /*
406  * Update TDMA state on receipt of a beacon frame with
407  * a TDMA information element.  The sender's identity
408  * is provided so we can track who our peer is.  If pickslot
409  * is non-zero we scan the slot allocation state in the ie
410  * to locate a free slot for our use.
411  */
412 static int
413 tdma_update(struct ieee80211vap *vap, const struct ieee80211_tdma_param *tdma,
414 	struct ieee80211_node *ni, int pickslot)
415 {
416 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
417 	int slot, slotlen, update;
418 
419 	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
420 	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
421 
422 	update = 0;
423 	if (tdma->tdma_slotcnt != ts->tdma_slotcnt) {
424 		if (!TDMA_SLOTCNT_VALID(tdma->tdma_slotcnt)) {
425 			if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
426 				printf("%s: bad slot cnt %u\n",
427 				    __func__, tdma->tdma_slotcnt);
428 			return 0;
429 		}
430 		update |= TDMA_UPDATE_SLOTCNT;
431  	}
432 	slotlen = le16toh(tdma->tdma_slotlen) * 100;
433 	if (slotlen != ts->tdma_slotlen) {
434 		if (!TDMA_SLOTLEN_VALID(slotlen)) {
435 			if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
436 				printf("%s: bad slot len %u\n",
437 				    __func__, slotlen);
438 			return 0;
439 		}
440 		update |= TDMA_UPDATE_SLOTLEN;
441  	}
442 	if (tdma->tdma_bintval != ts->tdma_bintval) {
443 		if (!TDMA_BINTVAL_VALID(tdma->tdma_bintval)) {
444 			if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
445 				printf("%s: bad beacon interval %u\n",
446 				    __func__, tdma->tdma_bintval);
447 			return 0;
448 		}
449 		update |= TDMA_UPDATE_BINTVAL;
450  	}
451 	slot = ts->tdma_slot;
452 	if (pickslot) {
453 		/*
454 		 * Pick unoccupied slot.  Note we never choose slot 0.
455 		 */
456 		for (slot = tdma->tdma_slotcnt-1; slot > 0; slot--)
457 			if (isclr(tdma->tdma_inuse, slot))
458 				break;
459 		if (slot <= 0) {
460 			printf("%s: no free slot, slotcnt %u inuse: 0x%x\n",
461 				__func__, tdma->tdma_slotcnt,
462 				tdma->tdma_inuse[0]);
463 			/* XXX need to do something better */
464 			return 0;
465 		}
466 		if (slot != ts->tdma_slot)
467 			update |= TDMA_UPDATE_SLOT;
468 	}
469 	if (ni != ts->tdma_peer) {
470 		/* update everything */
471 		update = TDMA_UPDATE_SLOT
472 		       | TDMA_UPDATE_SLOTCNT
473 		       | TDMA_UPDATE_SLOTLEN
474 		       | TDMA_UPDATE_BINTVAL;
475 	}
476 
477 	if (update) {
478 		/*
479 		 * New/changed parameters; update runtime state.
480 		 */
481 		/* XXX overwrites user parameters */
482 		if (update & TDMA_UPDATE_SLOTCNT)
483 			ts->tdma_slotcnt = tdma->tdma_slotcnt;
484 		if (update & TDMA_UPDATE_SLOTLEN)
485 			ts->tdma_slotlen = slotlen;
486 		if (update & TDMA_UPDATE_SLOT)
487 			ts->tdma_slot = slot;
488 		if (update & TDMA_UPDATE_BINTVAL)
489 			ts->tdma_bintval = tdma->tdma_bintval;
490 		/* mark beacon to be updated before next xmit */
491 		ieee80211_beacon_notify(vap, IEEE80211_BEACON_TDMA);
492 
493 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_TDMA,
494 		    "%s: slot %u slotcnt %u slotlen %u us bintval %u\n",
495 		    __func__, ts->tdma_slot, ts->tdma_slotcnt,
496 		    ts->tdma_slotlen, ts->tdma_bintval);
497 	}
498 	/*
499 	 * Notify driver.  Note we can be called before
500 	 * entering RUN state if we scanned and are
501 	 * joining an existing bss.  In that case do not
502 	 * call the driver because not all necessary state
503 	 * has been setup.  The next beacon will dtrt.
504 	 */
505 	if (vap->iv_state == IEEE80211_S_RUN)
506 		vap->iv_ic->ic_tdma_update(ni, tdma, update);
507 	/*
508 	 * Dispatch join event on first beacon from new master.
509 	 */
510 	if (ts->tdma_peer != ni) {
511 		if (ts->tdma_peer != NULL)
512 			ieee80211_notify_node_leave(vap->iv_bss);
513 		ieee80211_notify_node_join(ni, 1);
514 		/* NB: no reference, we just use the address */
515 		ts->tdma_peer = ni;
516 	}
517 	return 1;
518 }
519 
520 /*
521  * Process received TDMA parameters.
522  */
523 static int
524 tdma_process_params(struct ieee80211_node *ni, const u_int8_t *ie,
525 	int rssi, int nf, const struct ieee80211_frame *wh)
526 {
527 	struct ieee80211vap *vap = ni->ni_vap;
528 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
529 	const struct ieee80211_tdma_param *tdma =
530 		(const struct ieee80211_tdma_param *) ie;
531 	u_int len = ie[1];
532 
533 	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
534 	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
535 
536 	if (len < sizeof(*tdma) - 2) {
537 		IEEE80211_DISCARD_IE(vap,
538 		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
539 		    wh, "tdma", "too short, len %u", len);
540 		return IEEE80211_REASON_IE_INVALID;
541 	}
542 	if (tdma->tdma_version != ts->tdma_version) {
543 		IEEE80211_DISCARD_IE(vap,
544 		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
545 		    wh, "tdma", "bad version %u (ours %u)",
546 		    tdma->tdma_version, ts->tdma_version);
547 		return IEEE80211_REASON_IE_INVALID;
548 	}
549  	/*
550 	 * NB: ideally we'd check against tdma_slotcnt, but that
551 	 * would require extra effort so do this easy check that
552 	 * covers the work below; more stringent checks are done
553 	 * before we make more extensive use of the ie contents.
554 	 */
555 	if (tdma->tdma_slot >= TDMA_MAXSLOTS) {
556 		IEEE80211_DISCARD_IE(vap,
557 		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
558 		    wh, "tdma", "invalid slot %u", tdma->tdma_slot);
559 		return IEEE80211_REASON_IE_INVALID;
560 	}
561 	/*
562 	 * Can reach here while scanning, update
563 	 * operational state only in RUN state.
564 	 */
565 	if (vap->iv_state == IEEE80211_S_RUN) {
566 		if (tdma->tdma_slot != ts->tdma_slot &&
567 		    isclr(ts->tdma_inuse, tdma->tdma_slot)) {
568 			IEEE80211_NOTE(vap, IEEE80211_MSG_TDMA, ni,
569 			    "discovered in slot %u", tdma->tdma_slot);
570 			setbit(ts->tdma_inuse, tdma->tdma_slot);
571 			/* XXX dispatch event only when operating as master */
572 			if (ts->tdma_slot == 0)
573 				ieee80211_notify_node_join(ni, 1);
574 		}
575 		setbit(ts->tdma_active, tdma->tdma_slot);
576 		if (tdma->tdma_slot == ts->tdma_slot-1) {
577 			/*
578 			 * Slave tsf synchronization to station
579 			 * just before us in the schedule. The driver
580 			 * is responsible for copying the timestamp
581 			 * of the received beacon into our beacon
582 			 * frame so the sender can calculate round
583 			 * trip time.  We cannot do that here because
584 			 * we don't know how to update our beacon frame.
585 			 */
586 			(void) tdma_update(vap, tdma, ni, 0);
587 			/* XXX reschedule swbmiss timer on parameter change */
588 		} else if (tdma->tdma_slot == ts->tdma_slot+1) {
589 			uint64_t tstamp;
590 #if 0
591 			uint32_t rstamp = (uint32_t) le64toh(rs->tsf);
592 			int32_t rtt;
593 #endif
594 			/*
595 			 * Use returned timstamp to calculate the
596 			 * roundtrip time.
597 			 */
598 			memcpy(&tstamp, tdma->tdma_tstamp, 8);
599 #if 0
600 			/* XXX use only 15 bits of rstamp */
601 			rtt = rstamp - (le64toh(tstamp) & 0x7fff);
602 			if (rtt < 0)
603 				rtt += 0x7fff;
604 			/* XXX hack to quiet normal use */
605 			IEEE80211_DPRINTF(vap, IEEE80211_MSG_DOT1X,
606 			    "tdma rtt %5u [rstamp %5u tstamp %llu]\n",
607 			    rtt, rstamp,
608 			    (unsigned long long) le64toh(tstamp));
609 #endif
610 		} else if (tdma->tdma_slot == ts->tdma_slot &&
611 		    le64toh(ni->ni_tstamp.tsf) > vap->iv_bss->ni_tstamp.tsf) {
612 			/*
613 			 * Station using the same slot as us and has
614 			 * been around longer than us; we must move.
615 			 * Note this can happen if stations do not
616 			 * see each other while scanning.
617 			 */
618 			IEEE80211_DPRINTF(vap, IEEE80211_MSG_TDMA,
619 			    "slot %u collision rxtsf %llu tsf %llu\n",
620 			    tdma->tdma_slot,
621 			    (unsigned long long) le64toh(ni->ni_tstamp.tsf),
622 			    vap->iv_bss->ni_tstamp.tsf);
623 			setbit(ts->tdma_inuse, tdma->tdma_slot);
624 
625 			(void) tdma_update(vap, tdma, ni, 1);
626 		}
627 	}
628 	return 0;
629 }
630 
631 int
632 ieee80211_tdma_getslot(struct ieee80211vap *vap)
633 {
634 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
635 
636 	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
637 	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
638 	return ts->tdma_slot;
639 }
640 
641 /*
642  * Parse a TDMA ie on station join and use it to setup node state.
643  */
644 void
645 ieee80211_parse_tdma(struct ieee80211_node *ni, const uint8_t *ie)
646 {
647 	struct ieee80211vap *vap = ni->ni_vap;
648 
649 	if (vap->iv_caps & IEEE80211_C_TDMA) {
650 		const struct ieee80211_tdma_param *tdma =
651 		    (const struct ieee80211_tdma_param *)ie;
652 		struct ieee80211_tdma_state *ts = vap->iv_tdma;
653 		/*
654 		 * Adopt TDMA configuration when joining an
655 		 * existing network.
656 		 */
657 		setbit(ts->tdma_inuse, tdma->tdma_slot);
658 		(void) tdma_update(vap, tdma, ni, 1);
659 		/*
660 		 * Propagate capabilities based on the local
661 		 * configuration and the remote station's advertised
662 		 * capabilities. In particular this permits us to
663 		 * enable use of QoS to disable ACK's.
664 		 */
665 		if ((vap->iv_flags & IEEE80211_F_WME) &&
666 		    ni->ni_ies.wme_ie != NULL)
667 			ni->ni_flags |= IEEE80211_NODE_QOS;
668 	}
669 }
670 
671 #define	TDMA_OUI_BYTES		0x00, 0x03, 0x7f
672 /*
673  * Add a TDMA parameters element to a frame.
674  */
675 uint8_t *
676 ieee80211_add_tdma(uint8_t *frm, struct ieee80211vap *vap)
677 {
678 #define	ADDSHORT(frm, v) do {			\
679 	frm[0] = (v) & 0xff;			\
680 	frm[1] = (v) >> 8;			\
681 	frm += 2;				\
682 } while (0)
683 	static const struct ieee80211_tdma_param param = {
684 		.tdma_id	= IEEE80211_ELEMID_VENDOR,
685 		.tdma_len	= sizeof(struct ieee80211_tdma_param) - 2,
686 		.tdma_oui	= { TDMA_OUI_BYTES },
687 		.tdma_type	= TDMA_OUI_TYPE,
688 		.tdma_subtype	= TDMA_SUBTYPE_PARAM,
689 		.tdma_version	= TDMA_VERSION,
690 	};
691 	const struct ieee80211_tdma_state *ts = vap->iv_tdma;
692 	uint16_t slotlen;
693 
694 	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
695 	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
696 
697 	memcpy(frm, &param, sizeof(param));
698 	frm += __offsetof(struct ieee80211_tdma_param, tdma_slot);
699 	*frm++ = ts->tdma_slot;
700 	*frm++ = ts->tdma_slotcnt;
701 	/* NB: convert units to fit in 16-bits */
702 	slotlen = ts->tdma_slotlen / 100;	/* 100us units */
703 	ADDSHORT(frm, slotlen);
704 	*frm++ = ts->tdma_bintval;
705 	*frm++ = ts->tdma_inuse[0];
706 	frm += 10;				/* pad+timestamp */
707 	return frm;
708 #undef ADDSHORT
709 }
710 #undef TDMA_OUI_BYTES
711 
712 /*
713  * Update TDMA state at TBTT.
714  */
715 void
716 ieee80211_tdma_update_beacon(struct ieee80211vap *vap,
717 	struct ieee80211_beacon_offsets *bo)
718 {
719 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
720 
721 	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
722 	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
723 
724 	if (isset(bo->bo_flags,  IEEE80211_BEACON_TDMA)) {
725 		(void) ieee80211_add_tdma(bo->bo_tdma, vap);
726 		clrbit(bo->bo_flags, IEEE80211_BEACON_TDMA);
727 	}
728 	if (ts->tdma_slot != 0)		/* only on master */
729 		return;
730 	if (ts->tdma_count <= 0) {
731 		/*
732 		 * Time to update the mask of active/inuse stations.
733 		 * We track stations that we've received a beacon
734 		 * frame from and update this mask periodically.
735 		 * This allows us to miss a few beacons before marking
736 		 * a slot free for re-use.
737 		 */
738 		ts->tdma_inuse[0] = ts->tdma_active[0];
739 		ts->tdma_active[0] = 0x01;
740 		/* update next time 'round */
741 		/* XXX use notify framework */
742 		setbit(bo->bo_flags, IEEE80211_BEACON_TDMA);
743 		/* NB: use s/w beacon miss threshold; may be too high */
744 		ts->tdma_count = vap->iv_bmissthreshold-1;
745 	} else
746 		ts->tdma_count--;
747 }
748 
749 static int
750 tdma_ioctl_get80211(struct ieee80211vap *vap, struct ieee80211req *ireq)
751 {
752 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
753 
754 	if ((vap->iv_caps & IEEE80211_C_TDMA) == 0)
755 		return ENOSYS;
756 
757 	switch (ireq->i_type) {
758 	case IEEE80211_IOC_TDMA_SLOT:
759 		ireq->i_val = ts->tdma_slot;
760 		break;
761 	case IEEE80211_IOC_TDMA_SLOTCNT:
762 		ireq->i_val = ts->tdma_slotcnt;
763 		break;
764 	case IEEE80211_IOC_TDMA_SLOTLEN:
765 		ireq->i_val = ts->tdma_slotlen;
766 		break;
767 	case IEEE80211_IOC_TDMA_BINTERVAL:
768 		ireq->i_val = ts->tdma_bintval;
769 		break;
770 	default:
771 		return ENOSYS;
772 	}
773 	return 0;
774 }
775 IEEE80211_IOCTL_GET(tdma, tdma_ioctl_get80211);
776 
777 static int
778 tdma_ioctl_set80211(struct ieee80211vap *vap, struct ieee80211req *ireq)
779 {
780 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
781 
782 	if ((vap->iv_caps & IEEE80211_C_TDMA) == 0)
783 		return ENOSYS;
784 
785 	switch (ireq->i_type) {
786 	case IEEE80211_IOC_TDMA_SLOT:
787 		if (!(0 <= ireq->i_val && ireq->i_val <= ts->tdma_slotcnt))
788 			return EINVAL;
789 		if (ireq->i_val != ts->tdma_slot) {
790 			ts->tdma_slot = ireq->i_val;
791 			goto restart;
792 		}
793 		break;
794 	case IEEE80211_IOC_TDMA_SLOTCNT:
795 		if (!TDMA_SLOTCNT_VALID(ireq->i_val))
796 			return EINVAL;
797 		if (ireq->i_val != ts->tdma_slotcnt) {
798 			ts->tdma_slotcnt = ireq->i_val;
799 			goto restart;
800 		}
801 		break;
802 	case IEEE80211_IOC_TDMA_SLOTLEN:
803 		/*
804 		 * XXX
805 		 * 150 insures at least 1/8 TU
806 		 * 0xfffff is the max duration for bursting
807 		 * (implict by way of 16-bit data type for i_val)
808 		 */
809 		if (!TDMA_SLOTLEN_VALID(ireq->i_val))
810 			return EINVAL;
811 		if (ireq->i_val != ts->tdma_slotlen) {
812 			ts->tdma_slotlen = ireq->i_val;
813 			goto restart;
814 		}
815 		break;
816 	case IEEE80211_IOC_TDMA_BINTERVAL:
817 		if (!TDMA_BINTVAL_VALID(ireq->i_val))
818 			return EINVAL;
819 		if (ireq->i_val != ts->tdma_bintval) {
820 			ts->tdma_bintval = ireq->i_val;
821 			goto restart;
822 		}
823 		break;
824 	default:
825 		return ENOSYS;
826 	}
827 	return 0;
828 restart:
829 	ieee80211_beacon_notify(vap, IEEE80211_BEACON_TDMA);
830 	return ERESTART;
831 }
832 IEEE80211_IOCTL_SET(tdma, tdma_ioctl_set80211);
833 
834 #endif	/* IEEE80211_SUPPORT_TDMA */
835