freebsd-skq/sys/net80211/ieee80211_power.c
sam df1bd7956d New ap-side power save implementation; the main change is to allow drivers
to queue frames previously encapsulated on a separate high priority list
that is dispatched before the unencapsulated frames (to preserve order).
2008-10-26 01:04:46 +00:00

528 lines
14 KiB
C

/*-
* Copyright (c) 2002-2008 Sam Leffler, Errno Consulting
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* IEEE 802.11 power save support.
*/
#include "opt_wlan.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_media.h>
#include <net/ethernet.h>
#include <net80211/ieee80211_var.h>
#include <net/bpf.h>
static void ieee80211_update_ps(struct ieee80211vap *, int);
static int ieee80211_set_tim(struct ieee80211_node *, int);
MALLOC_DEFINE(M_80211_POWER, "80211power", "802.11 power save state");
void
ieee80211_power_attach(struct ieee80211com *ic)
{
}
void
ieee80211_power_detach(struct ieee80211com *ic)
{
}
void
ieee80211_power_vattach(struct ieee80211vap *vap)
{
if (vap->iv_opmode == IEEE80211_M_HOSTAP ||
vap->iv_opmode == IEEE80211_M_IBSS) {
/* NB: driver should override */
vap->iv_update_ps = ieee80211_update_ps;
vap->iv_set_tim = ieee80211_set_tim;
}
}
void
ieee80211_power_latevattach(struct ieee80211vap *vap)
{
/*
* Allocate these only if needed. Beware that we
* know adhoc mode doesn't support ATIM yet...
*/
if (vap->iv_opmode == IEEE80211_M_HOSTAP) {
vap->iv_tim_len = howmany(vap->iv_max_aid,8) * sizeof(uint8_t);
MALLOC(vap->iv_tim_bitmap, uint8_t *, vap->iv_tim_len,
M_80211_POWER, M_NOWAIT | M_ZERO);
if (vap->iv_tim_bitmap == NULL) {
printf("%s: no memory for TIM bitmap!\n", __func__);
/* XXX good enough to keep from crashing? */
vap->iv_tim_len = 0;
}
}
}
void
ieee80211_power_vdetach(struct ieee80211vap *vap)
{
if (vap->iv_tim_bitmap != NULL) {
FREE(vap->iv_tim_bitmap, M_80211_POWER);
vap->iv_tim_bitmap = NULL;
}
}
void
ieee80211_psq_init(struct ieee80211_psq *psq, const char *name)
{
memset(psq, 0, sizeof(psq));
psq->psq_maxlen = IEEE80211_PS_MAX_QUEUE;
IEEE80211_PSQ_INIT(psq, name); /* OS-dependent setup */
}
void
ieee80211_psq_cleanup(struct ieee80211_psq *psq)
{
#if 0
psq_drain(psq); /* XXX should not be needed? */
#else
KASSERT(psq->psq_len == 0, ("%d frames on ps q", psq->psq_len));
#endif
IEEE80211_PSQ_DESTROY(psq); /* OS-dependent cleanup */
}
/*
* Return the highest priority frame in the ps queue.
*/
struct mbuf *
ieee80211_node_psq_dequeue(struct ieee80211_node *ni, int *qlen)
{
struct ieee80211_psq *psq = &ni->ni_psq;
struct ieee80211_psq_head *qhead;
struct mbuf *m;
IEEE80211_PSQ_LOCK(psq);
qhead = &psq->psq_head[0];
again:
if ((m = qhead->head) != NULL) {
if ((qhead->head = m->m_nextpkt) == NULL)
qhead->tail = NULL;
KASSERT(qhead->len > 0, ("qhead len %d", qhead->len));
qhead->len--;
KASSERT(psq->psq_len > 0, ("psq len %d", psq->psq_len));
psq->psq_len--;
m->m_nextpkt = NULL;
}
if (m == NULL && qhead == &psq->psq_head[0]) {
/* Algol-68 style for loop */
qhead = &psq->psq_head[1];
goto again;
}
if (qlen != NULL)
*qlen = psq->psq_len;
IEEE80211_PSQ_UNLOCK(psq);
return m;
}
/*
* Reclaim an mbuf from the ps q. If marked with M_ENCAP
* we assume there is a node reference that must be relcaimed.
*/
static void
psq_mfree(struct mbuf *m)
{
if (m->m_flags & M_ENCAP) {
struct ieee80211_node *ni = (void *) m->m_pkthdr.rcvif;
ieee80211_free_node(ni);
}
m->m_nextpkt = NULL;
m_freem(m);
}
/*
* Clear any frames queued in the power save queue.
* The number of frames that were present is returned.
*/
static int
psq_drain(struct ieee80211_psq *psq)
{
struct ieee80211_psq_head *qhead;
struct mbuf *m;
int qlen;
IEEE80211_PSQ_LOCK(psq);
qlen = psq->psq_len;
qhead = &psq->psq_head[0];
again:
while ((m = qhead->head) != NULL) {
qhead->head = m->m_nextpkt;
psq_mfree(m);
}
qhead->tail = NULL;
qhead->len = 0;
if (qhead == &psq->psq_head[0]) { /* Algol-68 style for loop */
qhead = &psq->psq_head[1];
goto again;
}
psq->psq_len = 0;
IEEE80211_PSQ_UNLOCK(psq);
return qlen;
}
/*
* Clear any frames queued in the power save queue.
* The number of frames that were present is returned.
*/
int
ieee80211_node_psq_drain(struct ieee80211_node *ni)
{
return psq_drain(&ni->ni_psq);
}
/*
* Age frames on the power save queue. The aging interval is
* 4 times the listen interval specified by the station. This
* number is factored into the age calculations when the frame
* is placed on the queue. We store ages as time differences
* so we can check and/or adjust only the head of the list.
* If a frame's age exceeds the threshold then discard it.
* The number of frames discarded is returned so the caller
* can check if it needs to adjust the tim.
*/
int
ieee80211_node_psq_age(struct ieee80211_node *ni)
{
struct ieee80211_psq *psq = &ni->ni_psq;
int discard = 0;
if (psq->psq_len != 0) {
#ifdef IEEE80211_DEBUG
struct ieee80211vap *vap = ni->ni_vap;
#endif
struct ieee80211_psq_head *qhead;
struct mbuf *m;
IEEE80211_PSQ_LOCK(psq);
qhead = &psq->psq_head[0];
again:
while ((m = qhead->head) != NULL &&
M_AGE_GET(m) < IEEE80211_INACT_WAIT) {
IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
"discard frame, age %u", M_AGE_GET(m));
if ((qhead->head = m->m_nextpkt) == NULL)
qhead->tail = NULL;
KASSERT(qhead->len > 0, ("qhead len %d", qhead->len));
qhead->len--;
KASSERT(psq->psq_len > 0, ("psq len %d", psq->psq_len));
psq->psq_len--;
psq_mfree(m);
discard++;
}
if (qhead == &psq->psq_head[0]) { /* Algol-68 style for loop */
qhead = &psq->psq_head[1];
goto again;
}
if (m != NULL)
M_AGE_SUB(m, IEEE80211_INACT_WAIT);
IEEE80211_PSQ_UNLOCK(psq);
IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
"discard %u frames for age", discard);
IEEE80211_NODE_STAT_ADD(ni, ps_discard, discard);
}
return discard;
}
/*
* Handle a change in the PS station occupancy.
*/
static void
ieee80211_update_ps(struct ieee80211vap *vap, int nsta)
{
KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP ||
vap->iv_opmode == IEEE80211_M_IBSS,
("operating mode %u", vap->iv_opmode));
}
/*
* Indicate whether there are frames queued for a station in power-save mode.
*/
static int
ieee80211_set_tim(struct ieee80211_node *ni, int set)
{
struct ieee80211vap *vap = ni->ni_vap;
struct ieee80211com *ic = ni->ni_ic;
uint16_t aid;
int changed;
KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP ||
vap->iv_opmode == IEEE80211_M_IBSS,
("operating mode %u", vap->iv_opmode));
aid = IEEE80211_AID(ni->ni_associd);
KASSERT(aid < vap->iv_max_aid,
("bogus aid %u, max %u", aid, vap->iv_max_aid));
IEEE80211_LOCK(ic);
changed = (set != (isset(vap->iv_tim_bitmap, aid) != 0));
if (changed) {
if (set) {
setbit(vap->iv_tim_bitmap, aid);
vap->iv_ps_pending++;
} else {
clrbit(vap->iv_tim_bitmap, aid);
vap->iv_ps_pending--;
}
/* NB: we know vap is in RUN state so no need to check */
vap->iv_update_beacon(vap, IEEE80211_BEACON_TIM);
}
IEEE80211_UNLOCK(ic);
return changed;
}
/*
* Save an outbound packet for a node in power-save sleep state.
* The new packet is placed on the node's saved queue, and the TIM
* is changed, if necessary.
*/
int
ieee80211_pwrsave(struct ieee80211_node *ni, struct mbuf *m)
{
struct ieee80211_psq *psq = &ni->ni_psq;
struct ieee80211vap *vap = ni->ni_vap;
struct ieee80211com *ic = ni->ni_ic;
struct ieee80211_psq_head *qhead;
int qlen, age;
IEEE80211_PSQ_LOCK(psq);
if (psq->psq_len >= psq->psq_maxlen) {
psq->psq_drops++;
IEEE80211_PSQ_UNLOCK(psq);
IEEE80211_NOTE(vap, IEEE80211_MSG_ANY, ni,
"pwr save q overflow, drops %d (size %d)",
psq->psq_drops, psq->psq_len);
#ifdef IEEE80211_DEBUG
if (ieee80211_msg_dumppkts(vap))
ieee80211_dump_pkt(ni->ni_ic, mtod(m, caddr_t),
m->m_len, -1, -1);
#endif
psq_mfree(m);
return ENOSPC;
}
/*
* Tag the frame with it's expiry time and insert it in
* the appropriate queue. The aging interval is 4 times
* the listen interval specified by the station. Frames
* that sit around too long are reclaimed using this
* information.
*/
/* TU -> secs. XXX handle overflow? */
age = IEEE80211_TU_TO_MS((ni->ni_intval * ic->ic_bintval) << 2) / 1000;
/*
* Encapsulated frames go on the high priority queue,
* other stuff goes on the low priority queue. We use
* this to order frames returned out of the driver
* ahead of frames we collect in ieee80211_start.
*/
if (m->m_flags & M_ENCAP)
qhead = &psq->psq_head[0];
else
qhead = &psq->psq_head[1];
if (qhead->tail == NULL) {
struct mbuf *mh;
qhead->head = m;
/*
* Take care to adjust age when inserting the first
* frame of a queue and the other queue already has
* frames. We need to preserve the age difference
* relationship so ieee80211_node_psq_age works.
*/
if (qhead == &psq->psq_head[1]) {
mh = psq->psq_head[0].head;
if (mh != NULL)
age-= M_AGE_GET(mh);
} else {
mh = psq->psq_head[1].head;
if (mh != NULL) {
int nage = M_AGE_GET(mh) - age;
/* XXX is clamping to zero good 'nuf? */
M_AGE_SET(mh, nage < 0 ? 0 : nage);
}
}
} else {
qhead->tail->m_nextpkt = m;
age -= M_AGE_GET(qhead->head);
}
KASSERT(age >= 0, ("age %d", age));
M_AGE_SET(m, age);
m->m_nextpkt = NULL;
qhead->tail = m;
qhead->len++;
qlen = ++(psq->psq_len);
IEEE80211_PSQ_UNLOCK(psq);
IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
"save frame with age %d, %u now queued", age, qlen);
if (qlen == 1 && vap->iv_set_tim != NULL)
vap->iv_set_tim(ni, 1);
return 0;
}
/*
* Move frames from the ps q to the vap's send queue
* and/or the driver's send queue; and kick the start
* method for each, as appropriate. Note we're careful
* to preserve packet ordering here.
*/
static void
pwrsave_flushq(struct ieee80211_node *ni)
{
struct ieee80211_psq *psq = &ni->ni_psq;
struct ieee80211vap *vap = ni->ni_vap;
struct ieee80211_psq_head *qhead;
struct ifnet *parent, *ifp;
IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
"flush ps queue, %u packets queued", psq->psq_len);
IEEE80211_PSQ_LOCK(psq);
qhead = &psq->psq_head[0]; /* 802.11 frames */
if (qhead->head != NULL) {
/* XXX could dispatch through vap and check M_ENCAP */
parent = vap->iv_ic->ic_ifp;
/* XXX need different driver interface */
/* XXX bypasses q max and OACTIVE */
IF_PREPEND_LIST(&parent->if_snd, qhead->head, qhead->tail,
qhead->len);
qhead->head = qhead->tail = NULL;
qhead->len = 0;
} else
parent = NULL;
qhead = &psq->psq_head[1]; /* 802.3 frames */
if (qhead->head != NULL) {
ifp = vap->iv_ifp;
/* XXX need different driver interface */
/* XXX bypasses q max and OACTIVE */
IF_PREPEND_LIST(&ifp->if_snd, qhead->head, qhead->tail,
qhead->len);
qhead->head = qhead->tail = NULL;
qhead->len = 0;
} else
ifp = NULL;
psq->psq_len = 0;
IEEE80211_PSQ_UNLOCK(psq);
/* NB: do this outside the psq lock */
/* XXX packets might get reordered if parent is OACTIVE */
if (parent != NULL)
if_start(parent);
if (ifp != NULL)
if_start(ifp);
}
/*
* Handle station power-save state change.
*/
void
ieee80211_node_pwrsave(struct ieee80211_node *ni, int enable)
{
struct ieee80211vap *vap = ni->ni_vap;
int update;
update = 0;
if (enable) {
if ((ni->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) {
vap->iv_ps_sta++;
update = 1;
}
ni->ni_flags |= IEEE80211_NODE_PWR_MGT;
IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
"power save mode on, %u sta's in ps mode", vap->iv_ps_sta);
if (update)
vap->iv_update_ps(vap, vap->iv_ps_sta);
} else {
if (ni->ni_flags & IEEE80211_NODE_PWR_MGT) {
vap->iv_ps_sta--;
update = 1;
}
ni->ni_flags &= ~IEEE80211_NODE_PWR_MGT;
IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
"power save mode off, %u sta's in ps mode", vap->iv_ps_sta);
/* NB: order here is intentional so TIM is clear before flush */
if (vap->iv_set_tim != NULL)
vap->iv_set_tim(ni, 0);
if (update) {
/* NB if no sta's in ps, driver should flush mc q */
vap->iv_update_ps(vap, vap->iv_ps_sta);
}
if (ni->ni_psq.psq_len != 0)
pwrsave_flushq(ni);
}
}
/*
* Handle power-save state change in station mode.
*/
void
ieee80211_sta_pwrsave(struct ieee80211vap *vap, int enable)
{
struct ieee80211_node *ni = vap->iv_bss;
if (!((enable != 0) ^ ((ni->ni_flags & IEEE80211_NODE_PWR_MGT) != 0)))
return;
IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
"sta power save mode %s", enable ? "on" : "off");
if (!enable) {
ni->ni_flags &= ~IEEE80211_NODE_PWR_MGT;
ieee80211_send_nulldata(ieee80211_ref_node(ni));
/*
* Flush any queued frames; we can do this immediately
* because we know they'll be queued behind the null
* data frame we send the ap.
* XXX can we use a data frame to take us out of ps?
*/
if (ni->ni_psq.psq_len != 0)
pwrsave_flushq(ni);
} else {
ni->ni_flags |= IEEE80211_NODE_PWR_MGT;
ieee80211_send_nulldata(ieee80211_ref_node(ni));
}
}