1/*-
2 * Copyright (c) 2002-2008 Sam Leffler, Errno Consulting
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include <sys/cdefs.h>
27__FBSDID("$FreeBSD$");
28
29/*
30 * IEEE 802.11 power save support.
31 */
32#include "opt_wlan.h"
33
34#include <sys/param.h>
35#include <sys/systm.h>
36#include <sys/kernel.h>
37
38#include <sys/socket.h>
39
40#include <net/if.h>
41#include <net/if_media.h>
42#include <net/ethernet.h>
43
44#include <net80211/ieee80211_var.h>
45
46#include <net/bpf.h>
47
48static void ieee80211_update_ps(struct ieee80211vap *, int);
49static int ieee80211_set_tim(struct ieee80211_node *, int);
50
51static MALLOC_DEFINE(M_80211_POWER, "80211power", "802.11 power save state");
52
53void
54ieee80211_power_attach(struct ieee80211com *ic)
55{
56}
57
58void
59ieee80211_power_detach(struct ieee80211com *ic)
60{
61}
62
63void
64ieee80211_power_vattach(struct ieee80211vap *vap)
65{
66	if (vap->iv_opmode == IEEE80211_M_HOSTAP ||
67	    vap->iv_opmode == IEEE80211_M_IBSS) {
68		/* NB: driver should override */
69		vap->iv_update_ps = ieee80211_update_ps;
70		vap->iv_set_tim = ieee80211_set_tim;
71	}
72	vap->iv_node_ps = ieee80211_node_pwrsave;
73	vap->iv_sta_ps = ieee80211_sta_pwrsave;
74}
75
76void
77ieee80211_power_latevattach(struct ieee80211vap *vap)
78{
79	/*
80	 * Allocate these only if needed.  Beware that we
81	 * know adhoc mode doesn't support ATIM yet...
82	 */
83	if (vap->iv_opmode == IEEE80211_M_HOSTAP) {
84		vap->iv_tim_len = howmany(vap->iv_max_aid,8) * sizeof(uint8_t);
85		vap->iv_tim_bitmap = (uint8_t *) malloc(vap->iv_tim_len,
86			M_80211_POWER, M_NOWAIT | M_ZERO);
87		if (vap->iv_tim_bitmap == NULL) {
88			printf("%s: no memory for TIM bitmap!\n", __func__);
89			/* XXX good enough to keep from crashing? */
90			vap->iv_tim_len = 0;
91		}
92	}
93}
94
95void
96ieee80211_power_vdetach(struct ieee80211vap *vap)
97{
98	if (vap->iv_tim_bitmap != NULL) {
99		free(vap->iv_tim_bitmap, M_80211_POWER);
100		vap->iv_tim_bitmap = NULL;
101	}
102}
103
104void
105ieee80211_psq_init(struct ieee80211_psq *psq, const char *name)
106{
107	memset(psq, 0, sizeof(*psq));
108	psq->psq_maxlen = IEEE80211_PS_MAX_QUEUE;
109	IEEE80211_PSQ_INIT(psq, name);		/* OS-dependent setup */
110}
111
112void
113ieee80211_psq_cleanup(struct ieee80211_psq *psq)
114{
115#if 0
116	psq_drain(psq);				/* XXX should not be needed? */
117#else
118	KASSERT(psq->psq_len == 0, ("%d frames on ps q", psq->psq_len));
119#endif
120	IEEE80211_PSQ_DESTROY(psq);		/* OS-dependent cleanup */
121}
122
123/*
124 * Return the highest priority frame in the ps queue.
125 */
126struct mbuf *
127ieee80211_node_psq_dequeue(struct ieee80211_node *ni, int *qlen)
128{
129	struct ieee80211_psq *psq = &ni->ni_psq;
130	struct ieee80211_psq_head *qhead;
131	struct mbuf *m;
132
133	IEEE80211_PSQ_LOCK(psq);
134	qhead = &psq->psq_head[0];
135again:
136	if ((m = qhead->head) != NULL) {
137		if ((qhead->head = m->m_nextpkt) == NULL)
138			qhead->tail = NULL;
139		KASSERT(qhead->len > 0, ("qhead len %d", qhead->len));
140		qhead->len--;
141		KASSERT(psq->psq_len > 0, ("psq len %d", psq->psq_len));
142		psq->psq_len--;
143		m->m_nextpkt = NULL;
144	}
145	if (m == NULL && qhead == &psq->psq_head[0]) {
146		/* Algol-68 style for loop */
147		qhead = &psq->psq_head[1];
148		goto again;
149	}
150	if (qlen != NULL)
151		*qlen = psq->psq_len;
152	IEEE80211_PSQ_UNLOCK(psq);
153	return m;
154}
155
156/*
157 * Reclaim an mbuf from the ps q.  If marked with M_ENCAP
158 * we assume there is a node reference that must be relcaimed.
159 */
160static void
161psq_mfree(struct mbuf *m)
162{
163	if (m->m_flags & M_ENCAP) {
164		struct ieee80211_node *ni = (void *) m->m_pkthdr.rcvif;
165		ieee80211_free_node(ni);
166	}
167	m->m_nextpkt = NULL;
168	m_freem(m);
169}
170
171/*
172 * Clear any frames queued in the power save queue.
173 * The number of frames that were present is returned.
174 */
175static int
176psq_drain(struct ieee80211_psq *psq)
177{
178	struct ieee80211_psq_head *qhead;
179	struct mbuf *m;
180	int qlen;
181
182	IEEE80211_PSQ_LOCK(psq);
183	qlen = psq->psq_len;
184	qhead = &psq->psq_head[0];
185again:
186	while ((m = qhead->head) != NULL) {
187		qhead->head = m->m_nextpkt;
188		psq_mfree(m);
189	}
190	qhead->tail = NULL;
191	qhead->len = 0;
192	if (qhead == &psq->psq_head[0]) {	/* Algol-68 style for loop */
193		qhead = &psq->psq_head[1];
194		goto again;
195	}
196	psq->psq_len = 0;
197	IEEE80211_PSQ_UNLOCK(psq);
198
199	return qlen;
200}
201
202/*
203 * Clear any frames queued in the power save queue.
204 * The number of frames that were present is returned.
205 */
206int
207ieee80211_node_psq_drain(struct ieee80211_node *ni)
208{
209	return psq_drain(&ni->ni_psq);
210}
211
212/*
213 * Age frames on the power save queue. The aging interval is
214 * 4 times the listen interval specified by the station.  This
215 * number is factored into the age calculations when the frame
216 * is placed on the queue.  We store ages as time differences
217 * so we can check and/or adjust only the head of the list.
218 * If a frame's age exceeds the threshold then discard it.
219 * The number of frames discarded is returned so the caller
220 * can check if it needs to adjust the tim.
221 */
222int
223ieee80211_node_psq_age(struct ieee80211_node *ni)
224{
225	struct ieee80211_psq *psq = &ni->ni_psq;
226	int discard = 0;
227
228	if (psq->psq_len != 0) {
229#ifdef IEEE80211_DEBUG
230		struct ieee80211vap *vap = ni->ni_vap;
231#endif
232		struct ieee80211_psq_head *qhead;
233		struct mbuf *m;
234
235		IEEE80211_PSQ_LOCK(psq);
236		qhead = &psq->psq_head[0];
237	again:
238		while ((m = qhead->head) != NULL &&
239		    M_AGE_GET(m) < IEEE80211_INACT_WAIT) {
240			IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
241			     "discard frame, age %u", M_AGE_GET(m));
242			if ((qhead->head = m->m_nextpkt) == NULL)
243				qhead->tail = NULL;
244			KASSERT(qhead->len > 0, ("qhead len %d", qhead->len));
245			qhead->len--;
246			KASSERT(psq->psq_len > 0, ("psq len %d", psq->psq_len));
247			psq->psq_len--;
248			psq_mfree(m);
249			discard++;
250		}
251		if (qhead == &psq->psq_head[0]) { /* Algol-68 style for loop */
252			qhead = &psq->psq_head[1];
253			goto again;
254		}
255		if (m != NULL)
256			M_AGE_SUB(m, IEEE80211_INACT_WAIT);
257		IEEE80211_PSQ_UNLOCK(psq);
258
259		IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
260		    "discard %u frames for age", discard);
261		IEEE80211_NODE_STAT_ADD(ni, ps_discard, discard);
262	}
263	return discard;
264}
265
266/*
267 * Handle a change in the PS station occupancy.
268 */
269static void
270ieee80211_update_ps(struct ieee80211vap *vap, int nsta)
271{
272
273	KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP ||
274		vap->iv_opmode == IEEE80211_M_IBSS,
275		("operating mode %u", vap->iv_opmode));
276}
277
278/*
279 * Indicate whether there are frames queued for a station in power-save mode.
280 */
281static int
282ieee80211_set_tim(struct ieee80211_node *ni, int set)
283{
284	struct ieee80211vap *vap = ni->ni_vap;
285	struct ieee80211com *ic = ni->ni_ic;
286	uint16_t aid;
287	int changed;
288
289	KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP ||
290		vap->iv_opmode == IEEE80211_M_IBSS,
291		("operating mode %u", vap->iv_opmode));
292
293	aid = IEEE80211_AID(ni->ni_associd);
294	KASSERT(aid < vap->iv_max_aid,
295		("bogus aid %u, max %u", aid, vap->iv_max_aid));
296
297	IEEE80211_LOCK(ic);
298	changed = (set != (isset(vap->iv_tim_bitmap, aid) != 0));
299	if (changed) {
300		if (set) {
301			setbit(vap->iv_tim_bitmap, aid);
302			vap->iv_ps_pending++;
303		} else {
304			clrbit(vap->iv_tim_bitmap, aid);
305			vap->iv_ps_pending--;
306		}
307		/* NB: we know vap is in RUN state so no need to check */
308		vap->iv_update_beacon(vap, IEEE80211_BEACON_TIM);
309	}
310	IEEE80211_UNLOCK(ic);
311
312	return changed;
313}
314
315/*
316 * Save an outbound packet for a node in power-save sleep state.
317 * The new packet is placed on the node's saved queue, and the TIM
318 * is changed, if necessary.
319 */
320int
321ieee80211_pwrsave(struct ieee80211_node *ni, struct mbuf *m)
322{
323	struct ieee80211_psq *psq = &ni->ni_psq;
324	struct ieee80211vap *vap = ni->ni_vap;
325	struct ieee80211com *ic = ni->ni_ic;
326	struct ieee80211_psq_head *qhead;
327	int qlen, age;
328
329	IEEE80211_PSQ_LOCK(psq);
330	if (psq->psq_len >= psq->psq_maxlen) {
331		psq->psq_drops++;
332		IEEE80211_PSQ_UNLOCK(psq);
333		IEEE80211_NOTE(vap, IEEE80211_MSG_ANY, ni,
334		    "pwr save q overflow, drops %d (size %d)",
335		    psq->psq_drops, psq->psq_len);
336#ifdef IEEE80211_DEBUG
337		if (ieee80211_msg_dumppkts(vap))
338			ieee80211_dump_pkt(ni->ni_ic, mtod(m, caddr_t),
339			    m->m_len, -1, -1);
340#endif
341		psq_mfree(m);
342		return ENOSPC;
343	}
344	/*
345	 * Tag the frame with it's expiry time and insert it in
346	 * the appropriate queue.  The aging interval is 4 times
347	 * the listen interval specified by the station. Frames
348	 * that sit around too long are reclaimed using this
349	 * information.
350	 */
351	/* TU -> secs.  XXX handle overflow? */
352	age = IEEE80211_TU_TO_MS((ni->ni_intval * ic->ic_bintval) << 2) / 1000;
353	/*
354	 * Encapsulated frames go on the high priority queue,
355	 * other stuff goes on the low priority queue.  We use
356	 * this to order frames returned out of the driver
357	 * ahead of frames we collect in ieee80211_start.
358	 */
359	if (m->m_flags & M_ENCAP)
360		qhead = &psq->psq_head[0];
361	else
362		qhead = &psq->psq_head[1];
363	if (qhead->tail == NULL) {
364		struct mbuf *mh;
365
366		qhead->head = m;
367		/*
368		 * Take care to adjust age when inserting the first
369		 * frame of a queue and the other queue already has
370		 * frames.  We need to preserve the age difference
371		 * relationship so ieee80211_node_psq_age works.
372		 */
373		if (qhead == &psq->psq_head[1]) {
374			mh = psq->psq_head[0].head;
375			if (mh != NULL)
376				age-= M_AGE_GET(mh);
377		} else {
378			mh = psq->psq_head[1].head;
379			if (mh != NULL) {
380				int nage = M_AGE_GET(mh) - age;
381				/* XXX is clamping to zero good 'nuf? */
382				M_AGE_SET(mh, nage < 0 ? 0 : nage);
383			}
384		}
385	} else {
386		qhead->tail->m_nextpkt = m;
387		age -= M_AGE_GET(qhead->head);
388	}
389	KASSERT(age >= 0, ("age %d", age));
390	M_AGE_SET(m, age);
391	m->m_nextpkt = NULL;
392	qhead->tail = m;
393	qhead->len++;
394	qlen = ++(psq->psq_len);
395	IEEE80211_PSQ_UNLOCK(psq);
396
397	IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
398	    "save frame with age %d, %u now queued", age, qlen);
399
400	if (qlen == 1 && vap->iv_set_tim != NULL)
401		vap->iv_set_tim(ni, 1);
402
403	return 0;
404}
405
406/*
407 * Move frames from the ps q to the vap's send queue
408 * and/or the driver's send queue; and kick the start
409 * method for each, as appropriate.  Note we're careful
410 * to preserve packet ordering here.
411 */
412static void
413pwrsave_flushq(struct ieee80211_node *ni)
414{
415	struct ieee80211_psq *psq = &ni->ni_psq;
416	struct ieee80211com *ic = ni->ni_ic;
417	struct ieee80211vap *vap = ni->ni_vap;
418	struct ieee80211_psq_head *qhead;
419	struct ifnet *parent, *ifp;
420	struct mbuf *parent_q = NULL, *ifp_q = NULL;
421	struct mbuf *m;
422
423	IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
424	    "flush ps queue, %u packets queued", psq->psq_len);
425
426	IEEE80211_PSQ_LOCK(psq);
427	qhead = &psq->psq_head[0];	/* 802.11 frames */
428	if (qhead->head != NULL) {
429		/* XXX could dispatch through vap and check M_ENCAP */
430		parent = vap->iv_ic->ic_ifp;
431		/* XXX need different driver interface */
432		/* XXX bypasses q max and OACTIVE */
433		parent_q = qhead->head;
434		qhead->head = qhead->tail = NULL;
435		qhead->len = 0;
436	} else
437		parent = NULL;
438
439	qhead = &psq->psq_head[1];	/* 802.3 frames */
440	if (qhead->head != NULL) {
441		ifp = vap->iv_ifp;
442		/* XXX need different driver interface */
443		/* XXX bypasses q max and OACTIVE */
444		ifp_q = qhead->head;
445		qhead->head = qhead->tail = NULL;
446		qhead->len = 0;
447	} else
448		ifp = NULL;
449	psq->psq_len = 0;
450	IEEE80211_PSQ_UNLOCK(psq);
451
452	/* NB: do this outside the psq lock */
453	/* XXX packets might get reordered if parent is OACTIVE */
454	/* parent frames, should be encapsulated */
455	if (parent != NULL) {
456		while (parent_q != NULL) {
457			m = parent_q;
458			parent_q = m->m_nextpkt;
459			m->m_nextpkt = NULL;
460			/* must be encapsulated */
461			KASSERT((m->m_flags & M_ENCAP),
462			    ("%s: parentq with non-M_ENCAP frame!\n",
463			    __func__));
464			/*
465			 * For encaped frames, we need to free the node
466			 * reference upon failure.
467			 */
468			if (ieee80211_parent_xmitpkt(ic, m) != 0)
469				ieee80211_free_node(ni);
470		}
471	}
472
473	/* VAP frames, aren't encapsulated */
474	if (ifp != NULL) {
475		while (ifp_q != NULL) {
476			m = ifp_q;
477			ifp_q = m->m_nextpkt;
478			m->m_nextpkt = NULL;
479			KASSERT((!(m->m_flags & M_ENCAP)),
480			    ("%s: vapq with M_ENCAP frame!\n", __func__));
481			(void) ieee80211_vap_xmitpkt(vap, m);
482		}
483	}
484}
485
486/*
487 * Handle station power-save state change.
488 */
489void
490ieee80211_node_pwrsave(struct ieee80211_node *ni, int enable)
491{
492	struct ieee80211vap *vap = ni->ni_vap;
493	int update;
494
495	update = 0;
496	if (enable) {
497		if ((ni->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) {
498			vap->iv_ps_sta++;
499			update = 1;
500		}
501		ni->ni_flags |= IEEE80211_NODE_PWR_MGT;
502		IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
503		    "power save mode on, %u sta's in ps mode", vap->iv_ps_sta);
504
505		if (update)
506			vap->iv_update_ps(vap, vap->iv_ps_sta);
507	} else {
508		if (ni->ni_flags & IEEE80211_NODE_PWR_MGT) {
509			vap->iv_ps_sta--;
510			update = 1;
511		}
512		ni->ni_flags &= ~IEEE80211_NODE_PWR_MGT;
513		IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
514		    "power save mode off, %u sta's in ps mode", vap->iv_ps_sta);
515
516		/* NB: order here is intentional so TIM is clear before flush */
517		if (vap->iv_set_tim != NULL)
518			vap->iv_set_tim(ni, 0);
519		if (update) {
520			/* NB if no sta's in ps, driver should flush mc q */
521			vap->iv_update_ps(vap, vap->iv_ps_sta);
522		}
523		if (ni->ni_psq.psq_len != 0)
524			pwrsave_flushq(ni);
525	}
526}
527
528/*
529 * Handle power-save state change in station mode.
530 */
531void
532ieee80211_sta_pwrsave(struct ieee80211vap *vap, int enable)
533{
534	struct ieee80211_node *ni = vap->iv_bss;
535
536	if (!((enable != 0) ^ ((ni->ni_flags & IEEE80211_NODE_PWR_MGT) != 0)))
537		return;
538
539	IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
540	    "sta power save mode %s", enable ? "on" : "off");
541	if (!enable) {
542		ni->ni_flags &= ~IEEE80211_NODE_PWR_MGT;
543		ieee80211_send_nulldata(ieee80211_ref_node(ni));
544		/*
545		 * Flush any queued frames; we can do this immediately
546		 * because we know they'll be queued behind the null
547		 * data frame we send the ap.
548		 * XXX can we use a data frame to take us out of ps?
549		 */
550		if (ni->ni_psq.psq_len != 0)
551			pwrsave_flushq(ni);
552	} else {
553		ni->ni_flags |= IEEE80211_NODE_PWR_MGT;
554		ieee80211_send_nulldata(ieee80211_ref_node(ni));
555	}
556}
557