1 files changed, 328 insertions, 0 deletions
diff --git a/sys/net80211/ieee80211_power.c b/sys/net80211/ieee80211_power.c
new file mode 100644
index 0000000..2064807
--- /dev/null
+++ b/sys/net80211/ieee80211_power.c
@@ -0,0 +1,328 @@
+/*-
+ * Copyright (c) 2002-2007 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 <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_set_tim(struct ieee80211_node *ni, int set);
+
+void
+ieee80211_power_attach(struct ieee80211com *ic)
+{
+	if (ic->ic_opmode == IEEE80211_M_HOSTAP ||
+	    ic->ic_opmode == IEEE80211_M_IBSS) {
+		/* NB: driver should override */
+		ic->ic_set_tim = ieee80211_set_tim;
+	}
+}
+
+void
+ieee80211_power_lateattach(struct ieee80211com *ic)
+{
+	/*
+	 * Allocate these only if needed.  Beware that we
+	 * know adhoc mode doesn't support ATIM yet...
+	 */
+	if (ic->ic_opmode == IEEE80211_M_HOSTAP) {
+		ic->ic_tim_len = howmany(ic->ic_max_aid,8) * sizeof(uint8_t);
+		MALLOC(ic->ic_tim_bitmap, uint8_t *, ic->ic_tim_len,
+			M_DEVBUF, M_NOWAIT | M_ZERO);
+		if (ic->ic_tim_bitmap == NULL) {
+			printf("%s: no memory for TIM bitmap!\n", __func__);
+			/* XXX good enough to keep from crashing? */
+			ic->ic_tim_len = 0;
+		}
+	}
+}
+
+void
+ieee80211_power_detach(struct ieee80211com *ic)
+{
+	if (ic->ic_tim_bitmap != NULL) {
+		FREE(ic->ic_tim_bitmap, M_DEVBUF);
+		ic->ic_tim_bitmap = NULL;
+	}
+}
+
+/*
+ * Clear any frames queued on a node's power save queue.
+ * The number of frames that were present is returned.
+ */
+int
+ieee80211_node_saveq_drain(struct ieee80211_node *ni)
+{
+	int qlen;
+
+	IEEE80211_NODE_SAVEQ_LOCK(ni);
+	qlen = IEEE80211_NODE_SAVEQ_QLEN(ni);
+	_IF_DRAIN(&ni->ni_savedq);
+	IEEE80211_NODE_SAVEQ_UNLOCK(ni);
+
+	return qlen;
+}
+
+/*
+ * 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_saveq_age(struct ieee80211_node *ni)
+{
+	int discard = 0;
+
+	if (IEEE80211_NODE_SAVEQ_QLEN(ni) != 0) {
+		struct mbuf *m;
+
+		IEEE80211_NODE_SAVEQ_LOCK(ni);
+		while (IF_POLL(&ni->ni_savedq, m) != NULL &&
+		     M_AGE_GET(m) < IEEE80211_INACT_WAIT) {
+IEEE80211_DPRINTF(ni->ni_ic, IEEE80211_MSG_POWER, "[%s] discard frame, age %u\n", ether_sprintf(ni->ni_macaddr), M_AGE_GET(m));/*XXX*/
+			_IEEE80211_NODE_SAVEQ_DEQUEUE_HEAD(ni, m);
+			m_freem(m);
+			discard++;
+		}
+		if (m != NULL)
+			M_AGE_SUB(m, IEEE80211_INACT_WAIT);
+		IEEE80211_NODE_SAVEQ_UNLOCK(ni);
+
+		IEEE80211_NOTE(ni->ni_ic, IEEE80211_MSG_POWER, ni,
+		    "discard %u frames for age", discard);
+		IEEE80211_NODE_STAT_ADD(ni, ps_discard, discard);
+	}
+	return discard;
+}
+
+/*
+ * Indicate whether there are frames queued for a station in power-save mode.
+ */
+static void
+ieee80211_set_tim(struct ieee80211_node *ni, int set)
+{
+	struct ieee80211com *ic = ni->ni_ic;
+	uint16_t aid;
+
+	KASSERT(ic->ic_opmode == IEEE80211_M_HOSTAP ||
+		ic->ic_opmode == IEEE80211_M_IBSS,
+		("operating mode %u", ic->ic_opmode));
+
+	aid = IEEE80211_AID(ni->ni_associd);
+	KASSERT(aid < ic->ic_max_aid,
+		("bogus aid %u, max %u", aid, ic->ic_max_aid));
+
+	IEEE80211_BEACON_LOCK(ic);
+	if (set != (isset(ic->ic_tim_bitmap, aid) != 0)) {
+		if (set) {
+			setbit(ic->ic_tim_bitmap, aid);
+			ic->ic_ps_pending++;
+		} else {
+			clrbit(ic->ic_tim_bitmap, aid);
+			ic->ic_ps_pending--;
+		}
+		ic->ic_flags |= IEEE80211_F_TIMUPDATE;
+	}
+	IEEE80211_BEACON_UNLOCK(ic);
+}
+
+/*
+ * 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.
+ */
+void
+ieee80211_pwrsave(struct ieee80211_node *ni, struct mbuf *m)
+{
+	struct ieee80211com *ic = ni->ni_ic;
+	int qlen, age;
+
+	IEEE80211_NODE_SAVEQ_LOCK(ni);
+	if (_IF_QFULL(&ni->ni_savedq)) {
+		_IF_DROP(&ni->ni_savedq);
+		IEEE80211_NODE_SAVEQ_UNLOCK(ni);
+		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ANY,
+			"[%s] pwr save q overflow, drops %d (size %d)\n",
+			ether_sprintf(ni->ni_macaddr), 
+			ni->ni_savedq.ifq_drops, IEEE80211_PS_MAX_QUEUE);
+#ifdef IEEE80211_DEBUG
+		if (ieee80211_msg_dumppkts(ic))
+			ieee80211_dump_pkt(ic, mtod(m, caddr_t), m->m_len, -1, -1);
+#endif
+		m_freem(m);
+		return;
+	}
+	/*
+	 * Tag the frame with it's expiry time and insert
+	 * it in the 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;
+	_IEEE80211_NODE_SAVEQ_ENQUEUE(ni, m, qlen, age);
+	IEEE80211_NODE_SAVEQ_UNLOCK(ni);
+
+	IEEE80211_DPRINTF(ic, IEEE80211_MSG_POWER,
+		"[%s] save frame with age %d, %u now queued\n",
+		ether_sprintf(ni->ni_macaddr), age, qlen);
+
+	if (qlen == 1 && ic->ic_set_tim != NULL)
+		ic->ic_set_tim(ni, 1);
+}
+
+/*
+ * Handle station power-save state change.
+ */
+void
+ieee80211_node_pwrsave(struct ieee80211_node *ni, int enable)
+{
+	struct ieee80211com *ic = ni->ni_ic;
+	struct mbuf *m, *mhead, *mtail;
+	int mcount;
+
+	if (enable) {
+		if ((ni->ni_flags & IEEE80211_NODE_PWR_MGT) == 0)
+			ic->ic_ps_sta++;
+		ni->ni_flags |= IEEE80211_NODE_PWR_MGT;
+		IEEE80211_NOTE(ic, IEEE80211_MSG_POWER, ni,
+		    "power save mode on, %u sta's in ps mode", ic->ic_ps_sta);
+		return;
+	}
+
+	if (ni->ni_flags & IEEE80211_NODE_PWR_MGT)
+		ic->ic_ps_sta--;
+	ni->ni_flags &= ~IEEE80211_NODE_PWR_MGT;
+	IEEE80211_NOTE(ic, IEEE80211_MSG_POWER, ni,
+	    "power save mode off, %u sta's in ps mode", ic->ic_ps_sta);
+	/* XXX if no stations in ps mode, flush mc frames */
+
+	/*
+	 * Flush queued unicast frames.
+	 */
+	if (IEEE80211_NODE_SAVEQ_QLEN(ni) == 0) {
+		if (ic->ic_set_tim != NULL)
+			ic->ic_set_tim(ni, 0);		/* just in case */
+		return;
+	}
+	IEEE80211_NOTE(ic, IEEE80211_MSG_POWER, ni,
+	    "flush ps queue, %u packets queue", IEEE80211_NODE_SAVEQ_QLEN(ni));
+	/*
+	 * Unload the frames from the ps q but don't send them
+	 * to the driver yet.  We do this in two stages to minimize
+	 * locking but also because there's no easy way to preserve
+	 * ordering given the existing ifnet access mechanisms.
+	 * XXX could be optimized
+	 */
+	IEEE80211_NODE_SAVEQ_LOCK(ni);
+	mcount = IEEE80211_NODE_SAVEQ_QLEN(ni);
+	mhead = mtail = NULL;
+	for (;;) {
+		_IEEE80211_NODE_SAVEQ_DEQUEUE_HEAD(ni, m);
+		if (m == NULL)
+			break;
+		if (mhead == NULL) {
+			mhead = m;
+			m->m_nextpkt = NULL;
+		} else
+			mtail->m_nextpkt = m;
+		mtail = m;
+	}
+	IEEE80211_NODE_SAVEQ_UNLOCK(ni);
+	if (mhead != NULL) {
+		/* XXX need different driver interface */
+		/* XXX bypasses q max */
+		IF_PREPEND_LIST(&ic->ic_ifp->if_snd, mhead, mtail, mcount);
+	}
+	if (ic->ic_set_tim != NULL)
+		ic->ic_set_tim(ni, 0);
+}
+
+/*
+ * Handle power-save state change in station mode.
+ */
+void
+ieee80211_sta_pwrsave(struct ieee80211com *ic, int enable)
+{
+	struct ieee80211_node *ni = ic->ic_bss;
+	int qlen;
+
+	if (!((enable != 0) ^ ((ni->ni_flags & IEEE80211_NODE_PWR_MGT) != 0)))
+		return;
+
+	IEEE80211_NOTE(ic, 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?
+		 */
+		qlen = IEEE80211_NODE_SAVEQ_QLEN(ni);
+		if (qlen != 0) {
+			IEEE80211_NOTE(ic, IEEE80211_MSG_POWER, ni,
+			    "flush ps queue, %u packets queued", qlen);
+			for (;;) {
+				struct mbuf *m;
+
+				IEEE80211_NODE_SAVEQ_LOCK(ni);
+				_IEEE80211_NODE_SAVEQ_DEQUEUE_HEAD(ni, m);
+				IEEE80211_NODE_SAVEQ_UNLOCK(ni);
+				if (m == NULL)
+					break;
+				/* XXX need different driver interface */
+				/* XXX bypasses q max */
+				IF_ENQUEUE(&ic->ic_ifp->if_snd, m);
+			}
+		}
+	} else {
+		ni->ni_flags |= IEEE80211_NODE_PWR_MGT;
+		ieee80211_send_nulldata(ieee80211_ref_node(ni));
+	}
+}