xref: /freebsd/sys/net80211/ieee80211_tdma.c (revision 0b3105a37d7adcadcb720112fed4dc4e8040be99)
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  */
112 CTASSERT(TDMA_MAXSLOTS == 2);
113 
114 static void tdma_vdetach(struct ieee80211vap *vap);
115 static int tdma_newstate(struct ieee80211vap *, enum ieee80211_state, int);
116 static void tdma_beacon_miss(struct ieee80211vap *vap);
117 static void tdma_recv_mgmt(struct ieee80211_node *, struct mbuf *,
118 	int subtype, const struct ieee80211_rx_stats *rxs, int rssi, int nf);
119 static int tdma_update(struct ieee80211vap *vap,
120 	const struct ieee80211_tdma_param *tdma, struct ieee80211_node *ni,
121 	int pickslot);
122 static int tdma_process_params(struct ieee80211_node *ni,
123 	const u_int8_t *ie, int rssi, int nf, const struct ieee80211_frame *wh);
124 
125 static void
126 settxparms(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 
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 
180 	setackpolicy(vap->iv_ic, 1);	/* disable ACK's */
181 
182 	ts->tdma_opdetach = vap->iv_opdetach;
183 	vap->iv_opdetach = tdma_vdetach;
184 	ts->tdma_newstate = vap->iv_newstate;
185 	vap->iv_newstate = tdma_newstate;
186 	vap->iv_bmiss = tdma_beacon_miss;
187 	ts->tdma_recv_mgmt = vap->iv_recv_mgmt;
188 	vap->iv_recv_mgmt = tdma_recv_mgmt;
189 
190 	vap->iv_tdma = ts;
191 }
192 
193 static void
194 tdma_vdetach(struct ieee80211vap *vap)
195 {
196 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
197 
198 	if (ts == NULL) {
199 		/* NB: should not have touched any ic state */
200 		return;
201 	}
202 	ts->tdma_opdetach(vap);
203 	IEEE80211_FREE(vap->iv_tdma, M_80211_VAP);
204 	vap->iv_tdma = NULL;
205 
206 	setackpolicy(vap->iv_ic, 0);	/* enable ACK's */
207 }
208 
209 static void
210 sta_leave(void *arg, struct ieee80211_node *ni)
211 {
212 	struct ieee80211vap *vap = arg;
213 
214 	if (ni->ni_vap == vap && ni != vap->iv_bss)
215 		ieee80211_node_leave(ni);
216 }
217 
218 /*
219  * TDMA state machine handler.
220  */
221 static int
222 tdma_newstate(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
223 {
224 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
225 	struct ieee80211com *ic = vap->iv_ic;
226 	enum ieee80211_state ostate;
227 	int status;
228 
229 	IEEE80211_LOCK_ASSERT(ic);
230 
231 	ostate = vap->iv_state;
232 	IEEE80211_DPRINTF(vap, IEEE80211_MSG_STATE, "%s: %s -> %s (%d)\n",
233 	    __func__, ieee80211_state_name[ostate],
234 	    ieee80211_state_name[nstate], arg);
235 
236 	if (vap->iv_flags_ext & IEEE80211_FEXT_SWBMISS)
237 		callout_stop(&vap->iv_swbmiss);
238 	if (nstate == IEEE80211_S_SCAN &&
239 	    (ostate == IEEE80211_S_INIT || ostate == IEEE80211_S_RUN) &&
240 	    ts->tdma_slot != 0) {
241 		/*
242 		 * Override adhoc behaviour when operating as a slave;
243 		 * we need to scan even if the channel is locked.
244 		 */
245 		vap->iv_state = nstate;			/* state transition */
246 		ieee80211_cancel_scan(vap);		/* background scan */
247 		if (ostate == IEEE80211_S_RUN) {
248 			/* purge station table; entries are stale */
249 			ieee80211_iterate_nodes(&ic->ic_sta, sta_leave, vap);
250 		}
251 		if (vap->iv_flags_ext & IEEE80211_FEXT_SCANREQ) {
252 			ieee80211_check_scan(vap,
253 			    vap->iv_scanreq_flags,
254 			    vap->iv_scanreq_duration,
255 			    vap->iv_scanreq_mindwell,
256 			    vap->iv_scanreq_maxdwell,
257 			    vap->iv_scanreq_nssid, vap->iv_scanreq_ssid);
258 			vap->iv_flags_ext &= ~IEEE80211_FEXT_SCANREQ;
259 		} else
260 			ieee80211_check_scan_current(vap);
261 		status = 0;
262 	} else {
263 		status = ts->tdma_newstate(vap, nstate, arg);
264 	}
265 	if (status == 0 &&
266 	    nstate == IEEE80211_S_RUN && ostate != IEEE80211_S_RUN &&
267 	    (vap->iv_flags_ext & IEEE80211_FEXT_SWBMISS) &&
268 	    ts->tdma_slot != 0 &&
269 	    vap->iv_des_chan == IEEE80211_CHAN_ANYC) {
270 		/*
271 		 * Start s/w beacon miss timer for slave devices w/o
272 		 * hardware support.  Note we do this only if we're
273 		 * not locked to a channel (i.e. roam to follow the
274 		 * master). The 2x is a fudge for our doing this in
275 		 * software.
276 		 */
277 		vap->iv_swbmiss_period = IEEE80211_TU_TO_TICKS(
278 		    2 * vap->iv_bmissthreshold * ts->tdma_bintval *
279 		    ((ts->tdma_slotcnt * ts->tdma_slotlen) / 1024));
280 		vap->iv_swbmiss_count = 0;
281 		callout_reset(&vap->iv_swbmiss, vap->iv_swbmiss_period,
282 			ieee80211_swbmiss, vap);
283 	}
284 	return status;
285 }
286 
287 static void
288 tdma_beacon_miss(struct ieee80211vap *vap)
289 {
290 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
291 
292 	IEEE80211_LOCK_ASSERT(vap->iv_ic);
293 
294 	KASSERT((vap->iv_ic->ic_flags & IEEE80211_F_SCAN) == 0, ("scanning"));
295 	KASSERT(vap->iv_state == IEEE80211_S_RUN,
296 	    ("wrong state %d", vap->iv_state));
297 
298 	IEEE80211_DPRINTF(vap,
299 		IEEE80211_MSG_STATE | IEEE80211_MSG_TDMA | IEEE80211_MSG_DEBUG,
300 		"beacon miss, mode %u state %s\n",
301 		vap->iv_opmode, ieee80211_state_name[vap->iv_state]);
302 
303 	callout_stop(&vap->iv_swbmiss);
304 
305 	if (ts->tdma_peer != NULL) {	/* XXX? can this be null? */
306 		ieee80211_notify_node_leave(vap->iv_bss);
307 		ts->tdma_peer = NULL;
308 		/*
309 		 * Treat beacon miss like an associate failure wrt the
310 		 * scan policy; this forces the entry in the scan cache
311 		 * to be ignored after several tries.
312 		 */
313 		ieee80211_scan_assoc_fail(vap, vap->iv_bss->ni_macaddr,
314 		    IEEE80211_STATUS_TIMEOUT);
315 	}
316 #if 0
317 	ts->tdma_inuse = 0;		/* clear slot usage */
318 #endif
319 	ieee80211_new_state(vap, IEEE80211_S_SCAN, 0);
320 }
321 
322 static void
323 tdma_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0,
324 	int subtype, const struct ieee80211_rx_stats *rxs, int rssi, int nf)
325 {
326 	struct ieee80211com *ic = ni->ni_ic;
327 	struct ieee80211vap *vap = ni->ni_vap;
328 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
329 
330 	if (subtype == IEEE80211_FC0_SUBTYPE_BEACON &&
331 	    (ic->ic_flags & IEEE80211_F_SCAN) == 0) {
332 		struct ieee80211_frame *wh = mtod(m0, struct ieee80211_frame *);
333 		struct ieee80211_scanparams scan;
334 
335 		/* XXX TODO: use rxstatus to determine off-channel beacons */
336 		if (ieee80211_parse_beacon(ni, m0, ic->ic_curchan, &scan) != 0)
337 			return;
338 		if (scan.tdma == NULL) {
339 			/*
340 			 * TDMA stations must beacon a TDMA ie; ignore
341 			 * any other station.
342 			 * XXX detect overlapping bss and change channel
343 			 */
344 			IEEE80211_DISCARD(vap,
345 			    IEEE80211_MSG_ELEMID | IEEE80211_MSG_INPUT,
346 			    wh, ieee80211_mgt_subtype_name[subtype >>
347 				IEEE80211_FC0_SUBTYPE_SHIFT],
348 			    "%s", "no TDMA ie");
349 			vap->iv_stats.is_rx_mgtdiscard++;
350 			return;
351 		}
352 		if (ni == vap->iv_bss &&
353 		    !IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) {
354 			/*
355 			 * Fake up a node for this newly
356 			 * discovered member of the IBSS.
357 			 */
358 			ni = ieee80211_add_neighbor(vap, wh, &scan);
359 			if (ni == NULL) {
360 				/* NB: stat kept for alloc failure */
361 				return;
362 			}
363 		}
364 		/*
365 		 * Check for state updates.
366 		 */
367 		if (IEEE80211_ADDR_EQ(wh->i_addr3, ni->ni_bssid)) {
368 			/*
369 			 * Count frame now that we know it's to be processed.
370 			 */
371 			vap->iv_stats.is_rx_beacon++;
372 			IEEE80211_NODE_STAT(ni, rx_beacons);
373 			/*
374 			 * Record tsf of last beacon.  NB: this must be
375 			 * done before calling tdma_process_params
376 			 * as deeper routines reference it.
377 			 */
378 			memcpy(&ni->ni_tstamp.data, scan.tstamp,
379 				sizeof(ni->ni_tstamp.data));
380 			/*
381 			 * Count beacon frame for s/w bmiss handling.
382 			 */
383 			vap->iv_swbmiss_count++;
384 			/*
385 			 * Process tdma ie.  The contents are used to sync
386 			 * the slot timing, reconfigure the bss, etc.
387 			 */
388 			(void) tdma_process_params(ni, scan.tdma, rssi, nf, wh);
389 			return;
390 		}
391 		/*
392 		 * NB: defer remaining work to the adhoc code; this causes
393 		 *     2x parsing of the frame but should happen infrequently
394 		 */
395 	}
396 	ts->tdma_recv_mgmt(ni, m0, subtype, rxs, rssi, nf);
397 }
398 
399 /*
400  * Update TDMA state on receipt of a beacon frame with
401  * a TDMA information element.  The sender's identity
402  * is provided so we can track who our peer is.  If pickslot
403  * is non-zero we scan the slot allocation state in the ie
404  * to locate a free slot for our use.
405  */
406 static int
407 tdma_update(struct ieee80211vap *vap, const struct ieee80211_tdma_param *tdma,
408 	struct ieee80211_node *ni, int pickslot)
409 {
410 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
411 	int slot, slotlen, update;
412 
413 	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
414 	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
415 
416 	update = 0;
417 	if (tdma->tdma_slotcnt != ts->tdma_slotcnt) {
418 		if (!TDMA_SLOTCNT_VALID(tdma->tdma_slotcnt)) {
419 			if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
420 				printf("%s: bad slot cnt %u\n",
421 				    __func__, tdma->tdma_slotcnt);
422 			return 0;
423 		}
424 		update |= TDMA_UPDATE_SLOTCNT;
425  	}
426 	slotlen = le16toh(tdma->tdma_slotlen) * 100;
427 	if (slotlen != ts->tdma_slotlen) {
428 		if (!TDMA_SLOTLEN_VALID(slotlen)) {
429 			if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
430 				printf("%s: bad slot len %u\n",
431 				    __func__, slotlen);
432 			return 0;
433 		}
434 		update |= TDMA_UPDATE_SLOTLEN;
435  	}
436 	if (tdma->tdma_bintval != ts->tdma_bintval) {
437 		if (!TDMA_BINTVAL_VALID(tdma->tdma_bintval)) {
438 			if (ppsratecheck(&ts->tdma_lastprint, &ts->tdma_fails, 1))
439 				printf("%s: bad beacon interval %u\n",
440 				    __func__, tdma->tdma_bintval);
441 			return 0;
442 		}
443 		update |= TDMA_UPDATE_BINTVAL;
444  	}
445 	slot = ts->tdma_slot;
446 	if (pickslot) {
447 		/*
448 		 * Pick unoccupied slot.  Note we never choose slot 0.
449 		 */
450 		for (slot = tdma->tdma_slotcnt-1; slot > 0; slot--)
451 			if (isclr(tdma->tdma_inuse, slot))
452 				break;
453 		if (slot <= 0) {
454 			printf("%s: no free slot, slotcnt %u inuse: 0x%x\n",
455 				__func__, tdma->tdma_slotcnt,
456 				tdma->tdma_inuse[0]);
457 			/* XXX need to do something better */
458 			return 0;
459 		}
460 		if (slot != ts->tdma_slot)
461 			update |= TDMA_UPDATE_SLOT;
462 	}
463 	if (ni != ts->tdma_peer) {
464 		/* update everything */
465 		update = TDMA_UPDATE_SLOT
466 		       | TDMA_UPDATE_SLOTCNT
467 		       | TDMA_UPDATE_SLOTLEN
468 		       | TDMA_UPDATE_BINTVAL;
469 	}
470 
471 	if (update) {
472 		/*
473 		 * New/changed parameters; update runtime state.
474 		 */
475 		/* XXX overwrites user parameters */
476 		if (update & TDMA_UPDATE_SLOTCNT)
477 			ts->tdma_slotcnt = tdma->tdma_slotcnt;
478 		if (update & TDMA_UPDATE_SLOTLEN)
479 			ts->tdma_slotlen = slotlen;
480 		if (update & TDMA_UPDATE_SLOT)
481 			ts->tdma_slot = slot;
482 		if (update & TDMA_UPDATE_BINTVAL)
483 			ts->tdma_bintval = tdma->tdma_bintval;
484 		/* mark beacon to be updated before next xmit */
485 		ieee80211_beacon_notify(vap, IEEE80211_BEACON_TDMA);
486 
487 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_TDMA,
488 		    "%s: slot %u slotcnt %u slotlen %u us bintval %u\n",
489 		    __func__, ts->tdma_slot, ts->tdma_slotcnt,
490 		    ts->tdma_slotlen, ts->tdma_bintval);
491 	}
492 	/*
493 	 * Notify driver.  Note we can be called before
494 	 * entering RUN state if we scanned and are
495 	 * joining an existing bss.  In that case do not
496 	 * call the driver because not all necessary state
497 	 * has been setup.  The next beacon will dtrt.
498 	 */
499 	if (vap->iv_state == IEEE80211_S_RUN)
500 		vap->iv_ic->ic_tdma_update(ni, tdma, update);
501 	/*
502 	 * Dispatch join event on first beacon from new master.
503 	 */
504 	if (ts->tdma_peer != ni) {
505 		if (ts->tdma_peer != NULL)
506 			ieee80211_notify_node_leave(vap->iv_bss);
507 		ieee80211_notify_node_join(ni, 1);
508 		/* NB: no reference, we just use the address */
509 		ts->tdma_peer = ni;
510 	}
511 	return 1;
512 }
513 
514 /*
515  * Process received TDMA parameters.
516  */
517 static int
518 tdma_process_params(struct ieee80211_node *ni, const u_int8_t *ie,
519 	int rssi, int nf, const struct ieee80211_frame *wh)
520 {
521 	struct ieee80211vap *vap = ni->ni_vap;
522 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
523 	const struct ieee80211_tdma_param *tdma =
524 		(const struct ieee80211_tdma_param *) ie;
525 	u_int len = ie[1];
526 
527 	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
528 	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
529 
530 	if (len < sizeof(*tdma) - 2) {
531 		IEEE80211_DISCARD_IE(vap,
532 		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
533 		    wh, "tdma", "too short, len %u", len);
534 		return IEEE80211_REASON_IE_INVALID;
535 	}
536 	if (tdma->tdma_version != ts->tdma_version) {
537 		IEEE80211_DISCARD_IE(vap,
538 		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
539 		    wh, "tdma", "bad version %u (ours %u)",
540 		    tdma->tdma_version, ts->tdma_version);
541 		return IEEE80211_REASON_IE_INVALID;
542 	}
543  	/*
544 	 * NB: ideally we'd check against tdma_slotcnt, but that
545 	 * would require extra effort so do this easy check that
546 	 * covers the work below; more stringent checks are done
547 	 * before we make more extensive use of the ie contents.
548 	 */
549 	if (tdma->tdma_slot >= TDMA_MAXSLOTS) {
550 		IEEE80211_DISCARD_IE(vap,
551 		    IEEE80211_MSG_ELEMID | IEEE80211_MSG_TDMA,
552 		    wh, "tdma", "invalid slot %u", tdma->tdma_slot);
553 		return IEEE80211_REASON_IE_INVALID;
554 	}
555 	/*
556 	 * Can reach here while scanning, update
557 	 * operational state only in RUN state.
558 	 */
559 	if (vap->iv_state == IEEE80211_S_RUN) {
560 		if (tdma->tdma_slot != ts->tdma_slot &&
561 		    isclr(ts->tdma_inuse, tdma->tdma_slot)) {
562 			IEEE80211_NOTE(vap, IEEE80211_MSG_TDMA, ni,
563 			    "discovered in slot %u", tdma->tdma_slot);
564 			setbit(ts->tdma_inuse, tdma->tdma_slot);
565 			/* XXX dispatch event only when operating as master */
566 			if (ts->tdma_slot == 0)
567 				ieee80211_notify_node_join(ni, 1);
568 		}
569 		setbit(ts->tdma_active, tdma->tdma_slot);
570 		if (tdma->tdma_slot == ts->tdma_slot-1) {
571 			/*
572 			 * Slave tsf synchronization to station
573 			 * just before us in the schedule. The driver
574 			 * is responsible for copying the timestamp
575 			 * of the received beacon into our beacon
576 			 * frame so the sender can calculate round
577 			 * trip time.  We cannot do that here because
578 			 * we don't know how to update our beacon frame.
579 			 */
580 			(void) tdma_update(vap, tdma, ni, 0);
581 			/* XXX reschedule swbmiss timer on parameter change */
582 		} else if (tdma->tdma_slot == ts->tdma_slot+1) {
583 			uint64_t tstamp;
584 #if 0
585 			uint32_t rstamp = (uint32_t) le64toh(rs->tsf);
586 			int32_t rtt;
587 #endif
588 			/*
589 			 * Use returned timstamp to calculate the
590 			 * roundtrip time.
591 			 */
592 			memcpy(&tstamp, tdma->tdma_tstamp, 8);
593 #if 0
594 			/* XXX use only 15 bits of rstamp */
595 			rtt = rstamp - (le64toh(tstamp) & 0x7fff);
596 			if (rtt < 0)
597 				rtt += 0x7fff;
598 			/* XXX hack to quiet normal use */
599 			IEEE80211_DPRINTF(vap, IEEE80211_MSG_DOT1X,
600 			    "tdma rtt %5u [rstamp %5u tstamp %llu]\n",
601 			    rtt, rstamp,
602 			    (unsigned long long) le64toh(tstamp));
603 #endif
604 		} else if (tdma->tdma_slot == ts->tdma_slot &&
605 		    le64toh(ni->ni_tstamp.tsf) > vap->iv_bss->ni_tstamp.tsf) {
606 			/*
607 			 * Station using the same slot as us and has
608 			 * been around longer than us; we must move.
609 			 * Note this can happen if stations do not
610 			 * see each other while scanning.
611 			 */
612 			IEEE80211_DPRINTF(vap, IEEE80211_MSG_TDMA,
613 			    "slot %u collision rxtsf %llu tsf %llu\n",
614 			    tdma->tdma_slot,
615 			    (unsigned long long) le64toh(ni->ni_tstamp.tsf),
616 			    vap->iv_bss->ni_tstamp.tsf);
617 			setbit(ts->tdma_inuse, tdma->tdma_slot);
618 
619 			(void) tdma_update(vap, tdma, ni, 1);
620 		}
621 	}
622 	return 0;
623 }
624 
625 int
626 ieee80211_tdma_getslot(struct ieee80211vap *vap)
627 {
628 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
629 
630 	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
631 	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
632 	return ts->tdma_slot;
633 }
634 
635 /*
636  * Parse a TDMA ie on station join and use it to setup node state.
637  */
638 void
639 ieee80211_parse_tdma(struct ieee80211_node *ni, const uint8_t *ie)
640 {
641 	struct ieee80211vap *vap = ni->ni_vap;
642 
643 	if (vap->iv_caps & IEEE80211_C_TDMA) {
644 		const struct ieee80211_tdma_param *tdma =
645 		    (const struct ieee80211_tdma_param *)ie;
646 		struct ieee80211_tdma_state *ts = vap->iv_tdma;
647 		/*
648 		 * Adopt TDMA configuration when joining an
649 		 * existing network.
650 		 */
651 		setbit(ts->tdma_inuse, tdma->tdma_slot);
652 		(void) tdma_update(vap, tdma, ni, 1);
653 		/*
654 		 * Propagate capabilities based on the local
655 		 * configuration and the remote station's advertised
656 		 * capabilities. In particular this permits us to
657 		 * enable use of QoS to disable ACK's.
658 		 */
659 		if ((vap->iv_flags & IEEE80211_F_WME) &&
660 		    ni->ni_ies.wme_ie != NULL)
661 			ni->ni_flags |= IEEE80211_NODE_QOS;
662 	}
663 }
664 
665 #define	TDMA_OUI_BYTES		0x00, 0x03, 0x7f
666 /*
667  * Add a TDMA parameters element to a frame.
668  */
669 uint8_t *
670 ieee80211_add_tdma(uint8_t *frm, struct ieee80211vap *vap)
671 {
672 #define	ADDSHORT(frm, v) do {			\
673 	frm[0] = (v) & 0xff;			\
674 	frm[1] = (v) >> 8;			\
675 	frm += 2;				\
676 } while (0)
677 	static const struct ieee80211_tdma_param param = {
678 		.tdma_id	= IEEE80211_ELEMID_VENDOR,
679 		.tdma_len	= sizeof(struct ieee80211_tdma_param) - 2,
680 		.tdma_oui	= { TDMA_OUI_BYTES },
681 		.tdma_type	= TDMA_OUI_TYPE,
682 		.tdma_subtype	= TDMA_SUBTYPE_PARAM,
683 		.tdma_version	= TDMA_VERSION,
684 	};
685 	const struct ieee80211_tdma_state *ts = vap->iv_tdma;
686 	uint16_t slotlen;
687 
688 	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
689 	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
690 
691 	memcpy(frm, &param, sizeof(param));
692 	frm += __offsetof(struct ieee80211_tdma_param, tdma_slot);
693 	*frm++ = ts->tdma_slot;
694 	*frm++ = ts->tdma_slotcnt;
695 	/* NB: convert units to fit in 16-bits */
696 	slotlen = ts->tdma_slotlen / 100;	/* 100us units */
697 	ADDSHORT(frm, slotlen);
698 	*frm++ = ts->tdma_bintval;
699 	*frm++ = ts->tdma_inuse[0];
700 	frm += 10;				/* pad+timestamp */
701 	return frm;
702 #undef ADDSHORT
703 }
704 #undef TDMA_OUI_BYTES
705 
706 /*
707  * Update TDMA state at TBTT.
708  */
709 void
710 ieee80211_tdma_update_beacon(struct ieee80211vap *vap,
711 	struct ieee80211_beacon_offsets *bo)
712 {
713 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
714 
715 	KASSERT(vap->iv_caps & IEEE80211_C_TDMA,
716 	     ("not a tdma vap, caps 0x%x", vap->iv_caps));
717 
718 	if (isset(bo->bo_flags,  IEEE80211_BEACON_TDMA)) {
719 		(void) ieee80211_add_tdma(bo->bo_tdma, vap);
720 		clrbit(bo->bo_flags, IEEE80211_BEACON_TDMA);
721 	}
722 	if (ts->tdma_slot != 0)		/* only on master */
723 		return;
724 	if (ts->tdma_count <= 0) {
725 		/*
726 		 * Time to update the mask of active/inuse stations.
727 		 * We track stations that we've received a beacon
728 		 * frame from and update this mask periodically.
729 		 * This allows us to miss a few beacons before marking
730 		 * a slot free for re-use.
731 		 */
732 		ts->tdma_inuse[0] = ts->tdma_active[0];
733 		ts->tdma_active[0] = 0x01;
734 		/* update next time 'round */
735 		/* XXX use notify framework */
736 		setbit(bo->bo_flags, IEEE80211_BEACON_TDMA);
737 		/* NB: use s/w beacon miss threshold; may be too high */
738 		ts->tdma_count = vap->iv_bmissthreshold-1;
739 	} else
740 		ts->tdma_count--;
741 }
742 
743 static int
744 tdma_ioctl_get80211(struct ieee80211vap *vap, struct ieee80211req *ireq)
745 {
746 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
747 
748 	if ((vap->iv_caps & IEEE80211_C_TDMA) == 0)
749 		return ENOSYS;
750 
751 	switch (ireq->i_type) {
752 	case IEEE80211_IOC_TDMA_SLOT:
753 		ireq->i_val = ts->tdma_slot;
754 		break;
755 	case IEEE80211_IOC_TDMA_SLOTCNT:
756 		ireq->i_val = ts->tdma_slotcnt;
757 		break;
758 	case IEEE80211_IOC_TDMA_SLOTLEN:
759 		ireq->i_val = ts->tdma_slotlen;
760 		break;
761 	case IEEE80211_IOC_TDMA_BINTERVAL:
762 		ireq->i_val = ts->tdma_bintval;
763 		break;
764 	default:
765 		return ENOSYS;
766 	}
767 	return 0;
768 }
769 IEEE80211_IOCTL_GET(tdma, tdma_ioctl_get80211);
770 
771 static int
772 tdma_ioctl_set80211(struct ieee80211vap *vap, struct ieee80211req *ireq)
773 {
774 	struct ieee80211_tdma_state *ts = vap->iv_tdma;
775 
776 	if ((vap->iv_caps & IEEE80211_C_TDMA) == 0)
777 		return ENOSYS;
778 
779 	switch (ireq->i_type) {
780 	case IEEE80211_IOC_TDMA_SLOT:
781 		if (!(0 <= ireq->i_val && ireq->i_val <= ts->tdma_slotcnt))
782 			return EINVAL;
783 		if (ireq->i_val != ts->tdma_slot) {
784 			ts->tdma_slot = ireq->i_val;
785 			goto restart;
786 		}
787 		break;
788 	case IEEE80211_IOC_TDMA_SLOTCNT:
789 		if (!TDMA_SLOTCNT_VALID(ireq->i_val))
790 			return EINVAL;
791 		if (ireq->i_val != ts->tdma_slotcnt) {
792 			ts->tdma_slotcnt = ireq->i_val;
793 			goto restart;
794 		}
795 		break;
796 	case IEEE80211_IOC_TDMA_SLOTLEN:
797 		/*
798 		 * XXX
799 		 * 150 insures at least 1/8 TU
800 		 * 0xfffff is the max duration for bursting
801 		 * (implict by way of 16-bit data type for i_val)
802 		 */
803 		if (!TDMA_SLOTLEN_VALID(ireq->i_val))
804 			return EINVAL;
805 		if (ireq->i_val != ts->tdma_slotlen) {
806 			ts->tdma_slotlen = ireq->i_val;
807 			goto restart;
808 		}
809 		break;
810 	case IEEE80211_IOC_TDMA_BINTERVAL:
811 		if (!TDMA_BINTVAL_VALID(ireq->i_val))
812 			return EINVAL;
813 		if (ireq->i_val != ts->tdma_bintval) {
814 			ts->tdma_bintval = ireq->i_val;
815 			goto restart;
816 		}
817 		break;
818 	default:
819 		return ENOSYS;
820 	}
821 	return 0;
822 restart:
823 	ieee80211_beacon_notify(vap, IEEE80211_BEACON_TDMA);
824 	return ERESTART;
825 }
826 IEEE80211_IOCTL_SET(tdma, tdma_ioctl_set80211);
827 
828 #endif	/* IEEE80211_SUPPORT_TDMA */
829