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: src/sys/net80211/ieee80211_power.c,v 1.6 2008/10/26 01:04:46 sam Exp $");
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
48 static void ieee80211_update_ps(struct ieee80211vap *, int);
49 static int ieee80211_set_tim(struct ieee80211_node *, int);
50
51 MALLOC_DEFINE(M_80211_POWER, "80211power", "802.11 power save state");
52
53 void
54 ieee80211_power_attach(struct ieee80211com *ic)
55 {
56 }
57
58 void
59 ieee80211_power_detach(struct ieee80211com *ic)
60 {
61 }
62
63 void
64 ieee80211_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 }
73
74 void
75 ieee80211_power_latevattach(struct ieee80211vap *vap)
76 {
77 /*
78 * Allocate these only if needed. Beware that we
79 * know adhoc mode doesn't support ATIM yet...
80 */
81 if (vap->iv_opmode == IEEE80211_M_HOSTAP) {
82 vap->iv_tim_len = howmany(vap->iv_max_aid,8) * sizeof(uint8_t);
83 MALLOC(vap->iv_tim_bitmap, uint8_t *, vap->iv_tim_len,
84 M_80211_POWER, M_NOWAIT | M_ZERO);
85 if (vap->iv_tim_bitmap == NULL) {
86 printf("%s: no memory for TIM bitmap!\n", __func__);
87 /* XXX good enough to keep from crashing? */
88 vap->iv_tim_len = 0;
89 }
90 }
91 }
92
93 void
94 ieee80211_power_vdetach(struct ieee80211vap *vap)
95 {
96 if (vap->iv_tim_bitmap != NULL) {
97 FREE(vap->iv_tim_bitmap, M_80211_POWER);
98 vap->iv_tim_bitmap = NULL;
99 }
100 }
101
102 void
103 ieee80211_psq_init(struct ieee80211_psq *psq, const char *name)
104 {
105 memset(psq, 0, sizeof(psq));
106 psq->psq_maxlen = IEEE80211_PS_MAX_QUEUE;
107 IEEE80211_PSQ_INIT(psq, name); /* OS-dependent setup */
108 }
109
110 void
111 ieee80211_psq_cleanup(struct ieee80211_psq *psq)
112 {
113 #if 0
114 psq_drain(psq); /* XXX should not be needed? */
115 #else
116 KASSERT(psq->psq_len == 0, ("%d frames on ps q", psq->psq_len));
117 #endif
118 IEEE80211_PSQ_DESTROY(psq); /* OS-dependent cleanup */
119 }
120
121 /*
122 * Return the highest priority frame in the ps queue.
123 */
124 struct mbuf *
125 ieee80211_node_psq_dequeue(struct ieee80211_node *ni, int *qlen)
126 {
127 struct ieee80211_psq *psq = &ni->ni_psq;
128 struct ieee80211_psq_head *qhead;
129 struct mbuf *m;
130
131 IEEE80211_PSQ_LOCK(psq);
132 qhead = &psq->psq_head[0];
133 again:
134 if ((m = qhead->head) != NULL) {
135 if ((qhead->head = m->m_nextpkt) == NULL)
136 qhead->tail = NULL;
137 KASSERT(qhead->len > 0, ("qhead len %d", qhead->len));
138 qhead->len--;
139 KASSERT(psq->psq_len > 0, ("psq len %d", psq->psq_len));
140 psq->psq_len--;
141 m->m_nextpkt = NULL;
142 }
143 if (m == NULL && qhead == &psq->psq_head[0]) {
144 /* Algol-68 style for loop */
145 qhead = &psq->psq_head[1];
146 goto again;
147 }
148 if (qlen != NULL)
149 *qlen = psq->psq_len;
150 IEEE80211_PSQ_UNLOCK(psq);
151 return m;
152 }
153
154 /*
155 * Reclaim an mbuf from the ps q. If marked with M_ENCAP
156 * we assume there is a node reference that must be relcaimed.
157 */
158 static void
159 psq_mfree(struct mbuf *m)
160 {
161 if (m->m_flags & M_ENCAP) {
162 struct ieee80211_node *ni = (void *) m->m_pkthdr.rcvif;
163 ieee80211_free_node(ni);
164 }
165 m->m_nextpkt = NULL;
166 m_freem(m);
167 }
168
169 /*
170 * Clear any frames queued in the power save queue.
171 * The number of frames that were present is returned.
172 */
173 static int
174 psq_drain(struct ieee80211_psq *psq)
175 {
176 struct ieee80211_psq_head *qhead;
177 struct mbuf *m;
178 int qlen;
179
180 IEEE80211_PSQ_LOCK(psq);
181 qlen = psq->psq_len;
182 qhead = &psq->psq_head[0];
183 again:
184 while ((m = qhead->head) != NULL) {
185 qhead->head = m->m_nextpkt;
186 psq_mfree(m);
187 }
188 qhead->tail = NULL;
189 qhead->len = 0;
190 if (qhead == &psq->psq_head[0]) { /* Algol-68 style for loop */
191 qhead = &psq->psq_head[1];
192 goto again;
193 }
194 psq->psq_len = 0;
195 IEEE80211_PSQ_UNLOCK(psq);
196
197 return qlen;
198 }
199
200 /*
201 * Clear any frames queued in the power save queue.
202 * The number of frames that were present is returned.
203 */
204 int
205 ieee80211_node_psq_drain(struct ieee80211_node *ni)
206 {
207 return psq_drain(&ni->ni_psq);
208 }
209
210 /*
211 * Age frames on the power save queue. The aging interval is
212 * 4 times the listen interval specified by the station. This
213 * number is factored into the age calculations when the frame
214 * is placed on the queue. We store ages as time differences
215 * so we can check and/or adjust only the head of the list.
216 * If a frame's age exceeds the threshold then discard it.
217 * The number of frames discarded is returned so the caller
218 * can check if it needs to adjust the tim.
219 */
220 int
221 ieee80211_node_psq_age(struct ieee80211_node *ni)
222 {
223 struct ieee80211_psq *psq = &ni->ni_psq;
224 int discard = 0;
225
226 if (psq->psq_len != 0) {
227 #ifdef IEEE80211_DEBUG
228 struct ieee80211vap *vap = ni->ni_vap;
229 #endif
230 struct ieee80211_psq_head *qhead;
231 struct mbuf *m;
232
233 IEEE80211_PSQ_LOCK(psq);
234 qhead = &psq->psq_head[0];
235 again:
236 while ((m = qhead->head) != NULL &&
237 M_AGE_GET(m) < IEEE80211_INACT_WAIT) {
238 IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
239 "discard frame, age %u", M_AGE_GET(m));
240 if ((qhead->head = m->m_nextpkt) == NULL)
241 qhead->tail = NULL;
242 KASSERT(qhead->len > 0, ("qhead len %d", qhead->len));
243 qhead->len--;
244 KASSERT(psq->psq_len > 0, ("psq len %d", psq->psq_len));
245 psq->psq_len--;
246 psq_mfree(m);
247 discard++;
248 }
249 if (qhead == &psq->psq_head[0]) { /* Algol-68 style for loop */
250 qhead = &psq->psq_head[1];
251 goto again;
252 }
253 if (m != NULL)
254 M_AGE_SUB(m, IEEE80211_INACT_WAIT);
255 IEEE80211_PSQ_UNLOCK(psq);
256
257 IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
258 "discard %u frames for age", discard);
259 IEEE80211_NODE_STAT_ADD(ni, ps_discard, discard);
260 }
261 return discard;
262 }
263
264 /*
265 * Handle a change in the PS station occupancy.
266 */
267 static void
268 ieee80211_update_ps(struct ieee80211vap *vap, int nsta)
269 {
270
271 KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP ||
272 vap->iv_opmode == IEEE80211_M_IBSS,
273 ("operating mode %u", vap->iv_opmode));
274 }
275
276 /*
277 * Indicate whether there are frames queued for a station in power-save mode.
278 */
279 static int
280 ieee80211_set_tim(struct ieee80211_node *ni, int set)
281 {
282 struct ieee80211vap *vap = ni->ni_vap;
283 struct ieee80211com *ic = ni->ni_ic;
284 uint16_t aid;
285 int changed;
286
287 KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP ||
288 vap->iv_opmode == IEEE80211_M_IBSS,
289 ("operating mode %u", vap->iv_opmode));
290
291 aid = IEEE80211_AID(ni->ni_associd);
292 KASSERT(aid < vap->iv_max_aid,
293 ("bogus aid %u, max %u", aid, vap->iv_max_aid));
294
295 IEEE80211_LOCK(ic);
296 changed = (set != (isset(vap->iv_tim_bitmap, aid) != 0));
297 if (changed) {
298 if (set) {
299 setbit(vap->iv_tim_bitmap, aid);
300 vap->iv_ps_pending++;
301 } else {
302 clrbit(vap->iv_tim_bitmap, aid);
303 vap->iv_ps_pending--;
304 }
305 /* NB: we know vap is in RUN state so no need to check */
306 vap->iv_update_beacon(vap, IEEE80211_BEACON_TIM);
307 }
308 IEEE80211_UNLOCK(ic);
309
310 return changed;
311 }
312
313 /*
314 * Save an outbound packet for a node in power-save sleep state.
315 * The new packet is placed on the node's saved queue, and the TIM
316 * is changed, if necessary.
317 */
318 int
319 ieee80211_pwrsave(struct ieee80211_node *ni, struct mbuf *m)
320 {
321 struct ieee80211_psq *psq = &ni->ni_psq;
322 struct ieee80211vap *vap = ni->ni_vap;
323 struct ieee80211com *ic = ni->ni_ic;
324 struct ieee80211_psq_head *qhead;
325 int qlen, age;
326
327 IEEE80211_PSQ_LOCK(psq);
328 if (psq->psq_len >= psq->psq_maxlen) {
329 psq->psq_drops++;
330 IEEE80211_PSQ_UNLOCK(psq);
331 IEEE80211_NOTE(vap, IEEE80211_MSG_ANY, ni,
332 "pwr save q overflow, drops %d (size %d)",
333 psq->psq_drops, psq->psq_len);
334 #ifdef IEEE80211_DEBUG
335 if (ieee80211_msg_dumppkts(vap))
336 ieee80211_dump_pkt(ni->ni_ic, mtod(m, caddr_t),
337 m->m_len, -1, -1);
338 #endif
339 psq_mfree(m);
340 return ENOSPC;
341 }
342 /*
343 * Tag the frame with it's expiry time and insert it in
344 * the appropriate queue. The aging interval is 4 times
345 * the listen interval specified by the station. Frames
346 * that sit around too long are reclaimed using this
347 * information.
348 */
349 /* TU -> secs. XXX handle overflow? */
350 age = IEEE80211_TU_TO_MS((ni->ni_intval * ic->ic_bintval) << 2) / 1000;
351 /*
352 * Encapsulated frames go on the high priority queue,
353 * other stuff goes on the low priority queue. We use
354 * this to order frames returned out of the driver
355 * ahead of frames we collect in ieee80211_start.
356 */
357 if (m->m_flags & M_ENCAP)
358 qhead = &psq->psq_head[0];
359 else
360 qhead = &psq->psq_head[1];
361 if (qhead->tail == NULL) {
362 struct mbuf *mh;
363
364 qhead->head = m;
365 /*
366 * Take care to adjust age when inserting the first
367 * frame of a queue and the other queue already has
368 * frames. We need to preserve the age difference
369 * relationship so ieee80211_node_psq_age works.
370 */
371 if (qhead == &psq->psq_head[1]) {
372 mh = psq->psq_head[0].head;
373 if (mh != NULL)
374 age-= M_AGE_GET(mh);
375 } else {
376 mh = psq->psq_head[1].head;
377 if (mh != NULL) {
378 int nage = M_AGE_GET(mh) - age;
379 /* XXX is clamping to zero good 'nuf? */
380 M_AGE_SET(mh, nage < 0 ? 0 : nage);
381 }
382 }
383 } else {
384 qhead->tail->m_nextpkt = m;
385 age -= M_AGE_GET(qhead->head);
386 }
387 KASSERT(age >= 0, ("age %d", age));
388 M_AGE_SET(m, age);
389 m->m_nextpkt = NULL;
390 qhead->tail = m;
391 qhead->len++;
392 qlen = ++(psq->psq_len);
393 IEEE80211_PSQ_UNLOCK(psq);
394
395 IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
396 "save frame with age %d, %u now queued", age, qlen);
397
398 if (qlen == 1 && vap->iv_set_tim != NULL)
399 vap->iv_set_tim(ni, 1);
400
401 return 0;
402 }
403
404 /*
405 * Move frames from the ps q to the vap's send queue
406 * and/or the driver's send queue; and kick the start
407 * method for each, as appropriate. Note we're careful
408 * to preserve packet ordering here.
409 */
410 static void
411 pwrsave_flushq(struct ieee80211_node *ni)
412 {
413 struct ieee80211_psq *psq = &ni->ni_psq;
414 struct ieee80211vap *vap = ni->ni_vap;
415 struct ieee80211_psq_head *qhead;
416 struct ifnet *parent, *ifp;
417
418 IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
419 "flush ps queue, %u packets queued", psq->psq_len);
420
421 IEEE80211_PSQ_LOCK(psq);
422 qhead = &psq->psq_head[0]; /* 802.11 frames */
423 if (qhead->head != NULL) {
424 /* XXX could dispatch through vap and check M_ENCAP */
425 parent = vap->iv_ic->ic_ifp;
426 /* XXX need different driver interface */
427 /* XXX bypasses q max and OACTIVE */
428 IF_PREPEND_LIST(&parent->if_snd, qhead->head, qhead->tail,
429 qhead->len);
430 qhead->head = qhead->tail = NULL;
431 qhead->len = 0;
432 } else
433 parent = NULL;
434
435 qhead = &psq->psq_head[1]; /* 802.3 frames */
436 if (qhead->head != NULL) {
437 ifp = vap->iv_ifp;
438 /* XXX need different driver interface */
439 /* XXX bypasses q max and OACTIVE */
440 IF_PREPEND_LIST(&ifp->if_snd, qhead->head, qhead->tail,
441 qhead->len);
442 qhead->head = qhead->tail = NULL;
443 qhead->len = 0;
444 } else
445 ifp = NULL;
446 psq->psq_len = 0;
447 IEEE80211_PSQ_UNLOCK(psq);
448
449 /* NB: do this outside the psq lock */
450 /* XXX packets might get reordered if parent is OACTIVE */
451 if (parent != NULL)
452 if_start(parent);
453 if (ifp != NULL)
454 if_start(ifp);
455 }
456
457 /*
458 * Handle station power-save state change.
459 */
460 void
461 ieee80211_node_pwrsave(struct ieee80211_node *ni, int enable)
462 {
463 struct ieee80211vap *vap = ni->ni_vap;
464 int update;
465
466 update = 0;
467 if (enable) {
468 if ((ni->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) {
469 vap->iv_ps_sta++;
470 update = 1;
471 }
472 ni->ni_flags |= IEEE80211_NODE_PWR_MGT;
473 IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
474 "power save mode on, %u sta's in ps mode", vap->iv_ps_sta);
475
476 if (update)
477 vap->iv_update_ps(vap, vap->iv_ps_sta);
478 } else {
479 if (ni->ni_flags & IEEE80211_NODE_PWR_MGT) {
480 vap->iv_ps_sta--;
481 update = 1;
482 }
483 ni->ni_flags &= ~IEEE80211_NODE_PWR_MGT;
484 IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
485 "power save mode off, %u sta's in ps mode", vap->iv_ps_sta);
486
487 /* NB: order here is intentional so TIM is clear before flush */
488 if (vap->iv_set_tim != NULL)
489 vap->iv_set_tim(ni, 0);
490 if (update) {
491 /* NB if no sta's in ps, driver should flush mc q */
492 vap->iv_update_ps(vap, vap->iv_ps_sta);
493 }
494 if (ni->ni_psq.psq_len != 0)
495 pwrsave_flushq(ni);
496 }
497 }
498
499 /*
500 * Handle power-save state change in station mode.
501 */
502 void
503 ieee80211_sta_pwrsave(struct ieee80211vap *vap, int enable)
504 {
505 struct ieee80211_node *ni = vap->iv_bss;
506
507 if (!((enable != 0) ^ ((ni->ni_flags & IEEE80211_NODE_PWR_MGT) != 0)))
508 return;
509
510 IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
511 "sta power save mode %s", enable ? "on" : "off");
512 if (!enable) {
513 ni->ni_flags &= ~IEEE80211_NODE_PWR_MGT;
514 ieee80211_send_nulldata(ieee80211_ref_node(ni));
515 /*
516 * Flush any queued frames; we can do this immediately
517 * because we know they'll be queued behind the null
518 * data frame we send the ap.
519 * XXX can we use a data frame to take us out of ps?
520 */
521 if (ni->ni_psq.psq_len != 0)
522 pwrsave_flushq(ni);
523 } else {
524 ni->ni_flags |= IEEE80211_NODE_PWR_MGT;
525 ieee80211_send_nulldata(ieee80211_ref_node(ni));
526 }
527 }
528
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