Import IEEE 802.11 from FreeBSD.

1 files changed, 84 insertions, 649 deletions

diff --git a/freebsd/sys/net80211/ieee80211_scan.c b/freebsd/sys/net80211/ieee80211_scan.c
index 19becf8f..c3dfdb5e 100644
--- a/freebsd/sys/net80211/ieee80211_scan.c
+++ b/freebsd/sys/net80211/ieee80211_scan.c
@@ -37,45 +37,22 @@ __FBSDID("$FreeBSD$");
 #include <sys/systm.h> 
 #include <sys/proc.h>
 #include <sys/kernel.h>
+#include <sys/malloc.h>
 #include <sys/condvar.h>
  
 #include <sys/socket.h>
 
 #include <net/if.h>
+#include <net/if_var.h>
 #include <net/if_media.h>
 #include <net/ethernet.h>
 
 #include <net80211/ieee80211_var.h>
 
-#include <net/bpf.h>
-
-struct scan_state {
-	struct ieee80211_scan_state base;	/* public state */
-
-	u_int		ss_iflags;		/* flags used internally */
-#define	ISCAN_MINDWELL 	0x0001		/* min dwell time reached */
-#define	ISCAN_DISCARD	0x0002		/* discard rx'd frames */
-#define	ISCAN_CANCEL	0x0004		/* cancel current scan */
-#define	ISCAN_ABORT	0x0008		/* end the scan immediately */
-	unsigned long	ss_chanmindwell;	/* min dwell on curchan */
-	unsigned long	ss_scanend;		/* time scan must stop */
-	u_int		ss_duration;		/* duration for next scan */
-	struct task	ss_scan_task;		/* scan execution */
-	struct cv	ss_scan_cv;		/* scan signal */
-	struct callout	ss_scan_timer;		/* scan timer */
-};
-#define	SCAN_PRIVATE(ss)	((struct scan_state *) ss)
+/* XXX until it's implemented as attach ops */
+#include <net80211/ieee80211_scan_sw.h>
 
-/*
- * Amount of time to go off-channel during a background
- * scan.  This value should be large enough to catch most
- * ap's but short enough that we can return on-channel
- * before our listen interval expires.
- *
- * XXX tunable
- * XXX check against configured listen interval
- */
-#define	IEEE80211_SCAN_OFFCHANNEL	msecs_to_ticks(150)
+#include <net/bpf.h>
 
 /*
  * Roaming-related defaults.  RSSI thresholds are as returned by the
@@ -93,56 +70,32 @@ struct scan_state {
 #define	ROAM_RATE_HALF_DEFAULT		2*6	/* half-width 11a/g bss */
 #define	ROAM_RATE_QUARTER_DEFAULT	2*3	/* quarter-width 11a/g bss */
 #define	ROAM_MCS_11N_DEFAULT		(1 | IEEE80211_RATE_MCS) /* 11n bss */
-
-static	void scan_curchan(struct ieee80211_scan_state *, unsigned long);
-static	void scan_mindwell(struct ieee80211_scan_state *);
-static	void scan_signal(void *);
-static	void scan_task(void *, int);
-
-MALLOC_DEFINE(M_80211_SCAN, "80211scan", "802.11 scan state");
+#define	ROAM_MCS_11AC_DEFAULT		(1 | IEEE80211_RATE_MCS) /* 11ac bss; XXX not used yet */
 
 void
 ieee80211_scan_attach(struct ieee80211com *ic)
 {
-	struct scan_state *ss;
-
-	ss = (struct scan_state *) malloc(sizeof(struct scan_state),
-		M_80211_SCAN, M_NOWAIT | M_ZERO);
-	if (ss == NULL) {
-		ic->ic_scan = NULL;
-		return;
-	}
-	callout_init_mtx(&ss->ss_scan_timer, IEEE80211_LOCK_OBJ(ic), 0);
-	cv_init(&ss->ss_scan_cv, "scan");
-	TASK_INIT(&ss->ss_scan_task, 0, scan_task, ss);
-	ic->ic_scan = &ss->base;
-	ss->base.ss_ic = ic;
-
-	ic->ic_scan_curchan = scan_curchan;
-	ic->ic_scan_mindwell = scan_mindwell;
+	/*
+	 * If there's no scan method pointer, attach the
+	 * swscan set as a default.
+	 */
+	if (ic->ic_scan_methods == NULL)
+		ieee80211_swscan_attach(ic);
+	else
+		ic->ic_scan_methods->sc_attach(ic);
 }
 
 void
 ieee80211_scan_detach(struct ieee80211com *ic)
 {
-	struct ieee80211_scan_state *ss = ic->ic_scan;
 
-	if (ss != NULL) {
-		IEEE80211_LOCK(ic);
-		SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_ABORT;
-		scan_signal(ss);
-		IEEE80211_UNLOCK(ic);
-		ieee80211_draintask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
-		callout_drain(&SCAN_PRIVATE(ss)->ss_scan_timer);
-		KASSERT((ic->ic_flags & IEEE80211_F_SCAN) == 0,
-		    ("scan still running"));
-		if (ss->ss_ops != NULL) {
-			ss->ss_ops->scan_detach(ss);
-			ss->ss_ops = NULL;
-		}
-		ic->ic_scan = NULL;
-		free(SCAN_PRIVATE(ss), M_80211_SCAN);
-	}
+	/*
+	 * Ideally we'd do the ss_ops detach call here;
+	 * but then sc_detach() would need to be split in two.
+	 *
+	 * I'll do that later.
+	 */
+	ic->ic_scan_methods->sc_detach(ic);
 }
 
 static const struct ieee80211_roamparam defroam[IEEE80211_MODE_MAX] = {
@@ -166,17 +119,26 @@ static const struct ieee80211_roamparam defroam[IEEE80211_MODE_MAX] = {
 				    .rate = ROAM_MCS_11N_DEFAULT },
 	[IEEE80211_MODE_11NG]	= { .rssi = ROAM_RSSI_11B_DEFAULT,
 				    .rate = ROAM_MCS_11N_DEFAULT },
+	[IEEE80211_MODE_VHT_2GHZ]	= { .rssi = ROAM_RSSI_11B_DEFAULT,
+				    .rate = ROAM_MCS_11AC_DEFAULT },
+	[IEEE80211_MODE_VHT_5GHZ]	= { .rssi = ROAM_RSSI_11A_DEFAULT,
+				    .rate = ROAM_MCS_11AC_DEFAULT },
+
 };
 
 void
 ieee80211_scan_vattach(struct ieee80211vap *vap)
 {
+	struct ieee80211com *ic = vap->iv_ic;
+
 	vap->iv_bgscanidle = (IEEE80211_BGSCAN_IDLE_DEFAULT*1000)/hz;
 	vap->iv_bgscanintvl = IEEE80211_BGSCAN_INTVAL_DEFAULT*hz;
 	vap->iv_scanvalid = IEEE80211_SCAN_VALID_DEFAULT*hz;
 
 	vap->iv_roaming = IEEE80211_ROAMING_AUTO;
 	memcpy(vap->iv_roamparms, defroam, sizeof(defroam));
+
+	ic->ic_scan_methods->sc_vattach(vap);
 }
 
 void
@@ -187,11 +149,10 @@ ieee80211_scan_vdetach(struct ieee80211vap *vap)
 
 	IEEE80211_LOCK(ic);
 	ss = ic->ic_scan;
+
+	ic->ic_scan_methods->sc_vdetach(vap);
+
 	if (ss != NULL && ss->ss_vap == vap) {
-		if (ic->ic_flags & IEEE80211_F_SCAN) {
-			SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_ABORT;
-			scan_signal(ss);
-		}
 		if (ss->ss_ops != NULL) {
 			ss->ss_ops->scan_detach(ss);
 			ss->ss_ops = NULL;
@@ -262,8 +223,8 @@ ieee80211_scanner_unregister_all(const struct ieee80211_scanner *scan)
  * ensure later callbacks find ss_ops set to properly
  * reflect current operating mode.
  */
-static void
-scan_update_locked(struct ieee80211vap *vap,
+void
+ieee80211_scan_update_locked(struct ieee80211vap *vap,
 	const struct ieee80211_scanner *scan)
 {
 	struct ieee80211com *ic = vap->iv_ic;
@@ -308,26 +269,6 @@ scan_update_locked(struct ieee80211vap *vap,
 	}
 }
 
-static char
-channel_type(const struct ieee80211_channel *c)
-{
-	if (IEEE80211_IS_CHAN_ST(c))
-		return 'S';
-	if (IEEE80211_IS_CHAN_108A(c))
-		return 'T';
-	if (IEEE80211_IS_CHAN_108G(c))
-		return 'G';
-	if (IEEE80211_IS_CHAN_HT(c))
-		return 'n';
-	if (IEEE80211_IS_CHAN_A(c))
-		return 'a';
-	if (IEEE80211_IS_CHAN_ANYG(c))
-		return 'g';
-	if (IEEE80211_IS_CHAN_B(c))
-		return 'b';
-	return 'f';
-}
-
 void
 ieee80211_scan_dump_channels(const struct ieee80211_scan_state *ss)
 {
@@ -340,14 +281,14 @@ ieee80211_scan_dump_channels(const struct ieee80211_scan_state *ss)
 		const struct ieee80211_channel *c = ss->ss_chans[i];
 
 		printf("%s%u%c", sep, ieee80211_chan2ieee(ic, c),
-			channel_type(c));
+		    ieee80211_channel_type_char(c));
 		sep = ", ";
 	}
 }
 
 #ifdef IEEE80211_DEBUG
-static void
-scan_dump(struct ieee80211_scan_state *ss)
+void
+ieee80211_scan_dump(struct ieee80211_scan_state *ss)
 {
 	struct ieee80211vap *vap = ss->ss_vap;
 
@@ -358,8 +299,8 @@ scan_dump(struct ieee80211_scan_state *ss)
 }
 #endif /* IEEE80211_DEBUG */
 
-static void
-copy_ssid(struct ieee80211vap *vap, struct ieee80211_scan_state *ss,
+void
+ieee80211_scan_copy_ssid(struct ieee80211vap *vap, struct ieee80211_scan_state *ss,
 	int nssid, const struct ieee80211_scan_ssid ssids[])
 {
 	if (nssid > IEEE80211_SCAN_MAX_SSID) {
@@ -376,86 +317,13 @@ copy_ssid(struct ieee80211vap *vap, struct ieee80211_scan_state *ss,
 /*
  * Start a scan unless one is already going.
  */
-static int
-start_scan_locked(const struct ieee80211_scanner *scan,
-	struct ieee80211vap *vap, int flags, u_int duration,
-	u_int mindwell, u_int maxdwell,
-	u_int nssid, const struct ieee80211_scan_ssid ssids[])
-{
-	struct ieee80211com *ic = vap->iv_ic;
-	struct ieee80211_scan_state *ss = ic->ic_scan;
-
-	IEEE80211_LOCK_ASSERT(ic);
-
-	if (ic->ic_flags & IEEE80211_F_CSAPENDING) {
-		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
-		    "%s: scan inhibited by pending channel change\n", __func__);
-	} else if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
-		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
-		    "%s: %s scan, duration %u mindwell %u maxdwell %u, desired mode %s, %s%s%s%s%s%s\n"
-		    , __func__
-		    , flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"
-		    , duration, mindwell, maxdwell
-		    , ieee80211_phymode_name[vap->iv_des_mode]
-		    , flags & IEEE80211_SCAN_FLUSH ? "flush" : "append"
-		    , flags & IEEE80211_SCAN_NOPICK ? ", nopick" : ""
-		    , flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : ""
-		    , flags & IEEE80211_SCAN_NOBCAST ? ", nobcast" : ""
-		    , flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : ""
-		    , flags & IEEE80211_SCAN_ONCE ? ", once" : ""
-		);
-
-		scan_update_locked(vap, scan);
-		if (ss->ss_ops != NULL) {
-			if ((flags & IEEE80211_SCAN_NOSSID) == 0)
-				copy_ssid(vap, ss, nssid, ssids);
-
-			/* NB: top 4 bits for internal use */
-			ss->ss_flags = flags & 0xfff;
-			if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
-				vap->iv_stats.is_scan_active++;
-			else
-				vap->iv_stats.is_scan_passive++;
-			if (flags & IEEE80211_SCAN_FLUSH)
-				ss->ss_ops->scan_flush(ss);
-			if (flags & IEEE80211_SCAN_BGSCAN)
-				ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN;
-
-			/* NB: flush frames rx'd before 1st channel change */
-			SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
-			SCAN_PRIVATE(ss)->ss_duration = duration;
-			ss->ss_next = 0;
-			ss->ss_mindwell = mindwell;
-			ss->ss_maxdwell = maxdwell;
-			/* NB: scan_start must be before the scan runtask */
-			ss->ss_ops->scan_start(ss, vap);
-#ifdef IEEE80211_DEBUG
-			if (ieee80211_msg_scan(vap))
-				scan_dump(ss);
-#endif /* IEEE80211_DEBUG */
-			ic->ic_flags |= IEEE80211_F_SCAN;
-			ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
-		}
-		return 1;
-	} else {
-		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
-		    "%s: %s scan already in progress\n", __func__,
-		    ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
-	}
-	return 0;
-}
-
-/*
- * Start a scan unless one is already going.
- */
 int
 ieee80211_start_scan(struct ieee80211vap *vap, int flags,
 	u_int duration, u_int mindwell, u_int maxdwell,
 	u_int nssid, const struct ieee80211_scan_ssid ssids[])
 {
-	struct ieee80211com *ic = vap->iv_ic;
 	const struct ieee80211_scanner *scan;
-	int result;
+	struct ieee80211com *ic = vap->iv_ic;
 
 	scan = ieee80211_scanner_get(vap->iv_opmode);
 	if (scan == NULL) {
@@ -466,12 +334,8 @@ ieee80211_start_scan(struct ieee80211vap *vap, int flags,
 		return 0;
 	}
 
-	IEEE80211_LOCK(ic);
-	result = start_scan_locked(scan, vap, flags, duration,
+	return ic->ic_scan_methods->sc_start_scan(scan, vap, flags, duration,
 	    mindwell, maxdwell, nssid, ssids);
-	IEEE80211_UNLOCK(ic);
-
-	return result;
 }
 
 /*
@@ -518,49 +382,18 @@ ieee80211_check_scan(struct ieee80211vap *vap, int flags,
 		/* XXX re-use cache contents? e.g. adhoc<->sta */
 		flags |= IEEE80211_SCAN_FLUSH;
 	}
-	scan_update_locked(vap, scan);
-	if (ss->ss_ops != NULL) {
-		/* XXX verify ss_ops matches vap->iv_opmode */
-		if ((flags & IEEE80211_SCAN_NOSSID) == 0) {
-			/*
-			 * Update the ssid list and mark flags so if
-			 * we call start_scan it doesn't duplicate work.
-			 */
-			copy_ssid(vap, ss, nssid, ssids);
-			flags |= IEEE80211_SCAN_NOSSID;
-		}
-		if ((ic->ic_flags & IEEE80211_F_SCAN) == 0 &&
-		    (flags & IEEE80211_SCAN_FLUSH) == 0 &&
-		    time_before(ticks, ic->ic_lastscan + vap->iv_scanvalid)) {
-			/*
-			 * We're not currently scanning and the cache is
-			 * deemed hot enough to consult.  Lock out others
-			 * by marking IEEE80211_F_SCAN while we decide if
-			 * something is already in the scan cache we can
-			 * use.  Also discard any frames that might come
-			 * in while temporarily marked as scanning.
-			 */
-			SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
-			ic->ic_flags |= IEEE80211_F_SCAN;
-
-			/* NB: need to use supplied flags in check */
-			ss->ss_flags = flags & 0xff;
-			result = ss->ss_ops->scan_end(ss, vap);
-
-			ic->ic_flags &= ~IEEE80211_F_SCAN;
-			SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_DISCARD;
-			if (result) {
-				ieee80211_notify_scan_done(vap);
-				IEEE80211_UNLOCK(ic);
-				return 1;
-			}
-		}
-	}
-	result = start_scan_locked(scan, vap, flags, duration,
+
+	/*
+	 * XXX TODO: separate things out a bit better.
+	 */
+	ieee80211_scan_update_locked(vap, scan);
+
+	result = ic->ic_scan_methods->sc_check_scan(scan, vap, flags, duration,
 	    mindwell, maxdwell, nssid, ssids);
+
 	IEEE80211_UNLOCK(ic);
 
-	return result;
+	return (result);
 }
 
 /*
@@ -584,9 +417,10 @@ int
 ieee80211_bg_scan(struct ieee80211vap *vap, int flags)
 {
 	struct ieee80211com *ic = vap->iv_ic;
-	struct ieee80211_scan_state *ss = ic->ic_scan;
 	const struct ieee80211_scanner *scan;
 
+	// IEEE80211_UNLOCK_ASSERT(sc);
+
 	scan = ieee80211_scanner_get(vap->iv_opmode);
 	if (scan == NULL) {
 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
@@ -596,84 +430,12 @@ ieee80211_bg_scan(struct ieee80211vap *vap, int flags)
 		return 0;
 	}
 
-	IEEE80211_LOCK(ic);
-	if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
-		u_int duration;
-		/*
-		 * Go off-channel for a fixed interval that is large
-		 * enough to catch most ap's but short enough that
-		 * we can return on-channel before our listen interval
-		 * expires.
-		 */
-		duration = IEEE80211_SCAN_OFFCHANNEL;
-
-		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
-		    "%s: %s scan, ticks %u duration %lu\n", __func__,
-		    ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive",
-		    ticks, duration);
-
-		scan_update_locked(vap, scan);
-		if (ss->ss_ops != NULL) {
-			ss->ss_vap = vap;
-			/*
-			 * A background scan does not select a new sta; it
-			 * just refreshes the scan cache.  Also, indicate
-			 * the scan logic should follow the beacon schedule:
-			 * we go off-channel and scan for a while, then
-			 * return to the bss channel to receive a beacon,
-			 * then go off-channel again.  All during this time
-			 * we notify the ap we're in power save mode.  When
-			 * the scan is complete we leave power save mode.
-			 * If any beacon indicates there are frames pending
-			 * for us then we drop out of power save mode
-			 * (and background scan) automatically by way of the
-			 * usual sta power save logic.
-			 */
-			ss->ss_flags |= IEEE80211_SCAN_NOPICK
-				     |  IEEE80211_SCAN_BGSCAN
-				     |  flags
-				     ;
-			/* if previous scan completed, restart */
-			if (ss->ss_next >= ss->ss_last) {
-				if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
-					vap->iv_stats.is_scan_active++;
-				else
-					vap->iv_stats.is_scan_passive++;
-				/*
-				 * NB: beware of the scan cache being flushed;
-				 *     if the channel list is empty use the
-				 *     scan_start method to populate it.
-				 */
-				ss->ss_next = 0;
-				if (ss->ss_last != 0)
-					ss->ss_ops->scan_restart(ss, vap);
-				else {
-					ss->ss_ops->scan_start(ss, vap);
-#ifdef IEEE80211_DEBUG
-					if (ieee80211_msg_scan(vap))
-						scan_dump(ss);
-#endif /* IEEE80211_DEBUG */
-				}
-			}
-			/* NB: flush frames rx'd before 1st channel change */
-			SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
-			SCAN_PRIVATE(ss)->ss_duration = duration;
-			ss->ss_maxdwell = duration;
-			ic->ic_flags |= IEEE80211_F_SCAN;
-			ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN;
-			ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
-		} else {
-			/* XXX msg+stat */
-		}
-	} else {
-		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
-		    "%s: %s scan already in progress\n", __func__,
-		    ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
-	}
-	IEEE80211_UNLOCK(ic);
-
-	/* NB: racey, does it matter? */
-	return (ic->ic_flags & IEEE80211_F_SCAN);
+	/*
+	 * XXX TODO: pull apart the bgscan logic into whatever
+	 * belongs here and whatever belongs in the software
+	 * scanner.
+	 */
+	return (ic->ic_scan_methods->sc_bg_scan(scan, vap, flags));
 }
 
 /*
@@ -683,71 +445,41 @@ void
 ieee80211_cancel_scan(struct ieee80211vap *vap)
 {
 	struct ieee80211com *ic = vap->iv_ic;
-	struct ieee80211_scan_state *ss = ic->ic_scan;
 
-	IEEE80211_LOCK(ic);
-	if ((ic->ic_flags & IEEE80211_F_SCAN) &&
-	    ss->ss_vap == vap &&
-	    (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0) {
-		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
-		    "%s: cancel %s scan\n", __func__,
-		    ss->ss_flags & IEEE80211_SCAN_ACTIVE ?
-			"active" : "passive");
-
-		/* clear bg scan NOPICK and mark cancel request */
-		ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
-		SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_CANCEL;
-		/* wake up the scan task */
-		scan_signal(ss);
-	}
-	IEEE80211_UNLOCK(ic);
+	ic->ic_scan_methods->sc_cancel_scan(vap);
 }
 
 /*
  * Cancel any scan currently going on.
+ *
+ * This is called during normal 802.11 data path to cancel
+ * a scan so a newly arrived normal data packet can be sent.
  */
 void
 ieee80211_cancel_anyscan(struct ieee80211vap *vap)
 {
 	struct ieee80211com *ic = vap->iv_ic;
-	struct ieee80211_scan_state *ss = ic->ic_scan;
 
-	IEEE80211_LOCK(ic);
-	if ((ic->ic_flags & IEEE80211_F_SCAN) &&
-	    (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0) {
-		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
-		    "%s: cancel %s scan\n", __func__,
-		    ss->ss_flags & IEEE80211_SCAN_ACTIVE ?
-			"active" : "passive");
-
-		/* clear bg scan NOPICK and mark cancel request */
-		ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
-		SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_CANCEL;
-		/* wake up the scan task */
-		scan_signal(ss);
-	}
-	IEEE80211_UNLOCK(ic);
+	ic->ic_scan_methods->sc_cancel_anyscan(vap);
 }
 
 /*
- * Public access to scan_next for drivers that manage
- * scanning themselves (e.g. for firmware-based devices).
+ * Manually switch to the next channel in the channel list.
+ * Provided for drivers that manage scanning themselves
+ * (e.g. for firmware-based devices).
  */
 void
 ieee80211_scan_next(struct ieee80211vap *vap)
 {
 	struct ieee80211com *ic = vap->iv_ic;
-	struct ieee80211_scan_state *ss = ic->ic_scan;
 
-	/* wake up the scan task */
-	IEEE80211_LOCK(ic);
-	scan_signal(ss);
-	IEEE80211_UNLOCK(ic);
+	ic->ic_scan_methods->sc_scan_next(vap);
 }
 
 /*
- * Public access to scan_next for drivers that are not able to scan single
- * channels (e.g. for firmware-based devices).
+ * Manually stop a scan that is currently running.
+ * Provided for drivers that are not able to scan single channels
+ * (e.g. for firmware-based devices).
  */
 void
 ieee80211_scan_done(struct ieee80211vap *vap)
@@ -755,15 +487,19 @@ ieee80211_scan_done(struct ieee80211vap *vap)
 	struct ieee80211com *ic = vap->iv_ic;
 	struct ieee80211_scan_state *ss;
 
+	IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: called\n", __func__);
+
 	IEEE80211_LOCK(ic);
 	ss = ic->ic_scan;
 	ss->ss_next = ss->ss_last; /* all channels are complete */
-	scan_signal(ss);
+
+	ic->ic_scan_methods->sc_scan_done(vap);
+
 	IEEE80211_UNLOCK(ic);
 }
 
 /*
- * Probe the curent channel, if allowed, while scanning.
+ * Probe the current channel, if allowed, while scanning.
  * If the channel is not marked passive-only then send
  * a probe request immediately.  Otherwise mark state and
  * listen for beacons on the channel; if we receive something
@@ -773,279 +509,13 @@ void
 ieee80211_probe_curchan(struct ieee80211vap *vap, int force)
 {
 	struct ieee80211com *ic = vap->iv_ic;
-	struct ieee80211_scan_state *ss = ic->ic_scan;
-	struct ifnet *ifp = vap->iv_ifp;
-	int i;
 
 	if ((ic->ic_curchan->ic_flags & IEEE80211_CHAN_PASSIVE) && !force) {
 		ic->ic_flags_ext |= IEEE80211_FEXT_PROBECHAN;
 		return;
 	}
-	/*
-	 * Send directed probe requests followed by any
-	 * broadcast probe request.
-	 * XXX remove dependence on ic/vap->iv_bss
-	 */
-	for (i = 0; i < ss->ss_nssid; i++)
-		ieee80211_send_probereq(vap->iv_bss,
-			vap->iv_myaddr, ifp->if_broadcastaddr,
-			ifp->if_broadcastaddr,
-			ss->ss_ssid[i].ssid, ss->ss_ssid[i].len);
-	if ((ss->ss_flags & IEEE80211_SCAN_NOBCAST) == 0)
-		ieee80211_send_probereq(vap->iv_bss,
-			vap->iv_myaddr, ifp->if_broadcastaddr,
-			ifp->if_broadcastaddr,
-			"", 0);
-}
-
-/*
- * Scan curchan.  If this is an active scan and the channel
- * is not marked passive then send probe request frame(s).
- * Arrange for the channel change after maxdwell ticks.
- */
-static void
-scan_curchan(struct ieee80211_scan_state *ss, unsigned long maxdwell)
-{
-	struct ieee80211vap *vap  = ss->ss_vap;
-
-	IEEE80211_LOCK(vap->iv_ic);
-	if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
-		ieee80211_probe_curchan(vap, 0);
-	callout_reset(&SCAN_PRIVATE(ss)->ss_scan_timer,
-	    maxdwell, scan_signal, ss);
-	IEEE80211_UNLOCK(vap->iv_ic);
-}
-
-static void
-scan_signal(void *arg)
-{
-	struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg;
-
-	IEEE80211_LOCK_ASSERT(ss->ss_ic);
-
-	cv_signal(&SCAN_PRIVATE(ss)->ss_scan_cv);
-}
-
-/*
- * Handle mindwell requirements completed; initiate a channel
- * change to the next channel asap.
- */
-static void
-scan_mindwell(struct ieee80211_scan_state *ss)
-{
-	struct ieee80211com *ic = ss->ss_ic;
-
-	IEEE80211_LOCK(ic);
-	scan_signal(ss);
-	IEEE80211_UNLOCK(ic);
-}
-
-static void
-scan_task(void *arg, int pending)
-{
-#define	ISCAN_REP	(ISCAN_MINDWELL | ISCAN_DISCARD)
-	struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg;
-	struct ieee80211vap *vap = ss->ss_vap;
-	struct ieee80211com *ic = ss->ss_ic;
-	struct ieee80211_channel *chan;
-	unsigned long maxdwell, scanend;
-	int scandone = 0;
-
-	IEEE80211_LOCK(ic);
-	if (vap == NULL || (ic->ic_flags & IEEE80211_F_SCAN) == 0 ||
-	    (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT)) {
-		/* Cancelled before we started */
-		goto done;
-	}
-
-	if (ss->ss_next == ss->ss_last) {
-		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
-			"%s: no channels to scan\n", __func__);
-		goto done;
-	}
-
-	if (vap->iv_opmode == IEEE80211_M_STA &&
-	    vap->iv_state == IEEE80211_S_RUN) {
-		if ((vap->iv_bss->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) {
-			/* Enable station power save mode */
-			ieee80211_sta_pwrsave(vap, 1);
-			/*
-			 * Use an 1ms delay so the null data frame has a chance
-			 * to go out.
-			 * XXX Should use M_TXCB mechanism to eliminate this.
-			 */
-			cv_timedwait(&SCAN_PRIVATE(ss)->ss_scan_cv,
-			    IEEE80211_LOCK_OBJ(ic), hz / 1000);
-			if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT)
-				goto done;
-		}
-	}
-
-	scanend = ticks + SCAN_PRIVATE(ss)->ss_duration;
-	IEEE80211_UNLOCK(ic);
-	ic->ic_scan_start(ic);		/* notify driver */
-	IEEE80211_LOCK(ic);
-
-	for (;;) {
-		scandone = (ss->ss_next >= ss->ss_last) ||
-		    (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) != 0;
-		if (scandone || (ss->ss_flags & IEEE80211_SCAN_GOTPICK) ||
-		    (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT) ||
-		     time_after(ticks + ss->ss_mindwell, scanend))
-			break;
-
-		chan = ss->ss_chans[ss->ss_next++];
-
-		/*
-		 * Watch for truncation due to the scan end time.
-		 */
-		if (time_after(ticks + ss->ss_maxdwell, scanend))
-			maxdwell = scanend - ticks;
-		else
-			maxdwell = ss->ss_maxdwell;
-
-		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
-		    "%s: chan %3d%c -> %3d%c [%s, dwell min %lums max %lums]\n",
-		    __func__,
-		    ieee80211_chan2ieee(ic, ic->ic_curchan),
-		        channel_type(ic->ic_curchan),
-		    ieee80211_chan2ieee(ic, chan), channel_type(chan),
-		    (ss->ss_flags & IEEE80211_SCAN_ACTIVE) &&
-			(chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0 ?
-			"active" : "passive",
-		    ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(maxdwell));
-
-		/*
-		 * Potentially change channel and phy mode.
-		 */
-		ic->ic_curchan = chan;
-		ic->ic_rt = ieee80211_get_ratetable(chan);
-		IEEE80211_UNLOCK(ic);
-		/*
-		 * Perform the channel change and scan unlocked so the driver
-		 * may sleep. Once set_channel returns the hardware has
-		 * completed the channel change.
-		 */
-		ic->ic_set_channel(ic);
-		ieee80211_radiotap_chan_change(ic);
-
-		/*
-		 * Scan curchan.  Drivers for "intelligent hardware"
-		 * override ic_scan_curchan to tell the device to do
-		 * the work.  Otherwise we manage the work outselves;
-		 * sending a probe request (as needed), and arming the
-		 * timeout to switch channels after maxdwell ticks.
-		 *
-		 * scan_curchan should only pause for the time required to
-		 * prepare/initiate the hardware for the scan (if at all), the
-		 * below condvar is used to sleep for the channels dwell time
-		 * and allows it to be signalled for abort.
-		 */
-		ic->ic_scan_curchan(ss, maxdwell);
-		IEEE80211_LOCK(ic);
-
-		SCAN_PRIVATE(ss)->ss_chanmindwell = ticks + ss->ss_mindwell;
-		/* clear mindwell lock and initial channel change flush */
-		SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_REP;
-
-		if ((SCAN_PRIVATE(ss)->ss_iflags & (ISCAN_CANCEL|ISCAN_ABORT)))
-			continue;
-
-		/* Wait to be signalled to scan the next channel */
-		cv_wait(&SCAN_PRIVATE(ss)->ss_scan_cv, IEEE80211_LOCK_OBJ(ic));
-	}
-	if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT)
-		goto done;
-
-	IEEE80211_UNLOCK(ic);
-	ic->ic_scan_end(ic);		/* notify driver */
-	IEEE80211_LOCK(ic);
-
-	/*
-	 * Record scan complete time.  Note that we also do
-	 * this when canceled so any background scan will
-	 * not be restarted for a while.
-	 */
-	if (scandone)
-		ic->ic_lastscan = ticks;
-	/* return to the bss channel */
-	if (ic->ic_bsschan != IEEE80211_CHAN_ANYC &&
-	    ic->ic_curchan != ic->ic_bsschan) {
-		ieee80211_setupcurchan(ic, ic->ic_bsschan);
-		IEEE80211_UNLOCK(ic);
-		ic->ic_set_channel(ic);
-		ieee80211_radiotap_chan_change(ic);
-		IEEE80211_LOCK(ic);
-	}
-	/* clear internal flags and any indication of a pick */
-	SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_REP;
-	ss->ss_flags &= ~IEEE80211_SCAN_GOTPICK;
-
-	/*
-	 * If not canceled and scan completed, do post-processing.
-	 * If the callback function returns 0, then it wants to
-	 * continue/restart scanning.  Unfortunately we needed to
-	 * notify the driver to end the scan above to avoid having
-	 * rx frames alter the scan candidate list.
-	 */
-	if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0 &&
-	    !ss->ss_ops->scan_end(ss, vap) &&
-	    (ss->ss_flags & IEEE80211_SCAN_ONCE) == 0 &&
-	    time_before(ticks + ss->ss_mindwell, scanend)) {
-		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
-		    "%s: done, restart "
-		    "[ticks %u, dwell min %lu scanend %lu]\n",
-		    __func__,
-		    ticks, ss->ss_mindwell, scanend);
-		ss->ss_next = 0;	/* reset to begining */
-		if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
-			vap->iv_stats.is_scan_active++;
-		else
-			vap->iv_stats.is_scan_passive++;
-
-		ss->ss_ops->scan_restart(ss, vap);	/* XXX? */
-		ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
-		IEEE80211_UNLOCK(ic);
-		return;
-	}
-
-	/* past here, scandone is ``true'' if not in bg mode */
-	if ((ss->ss_flags & IEEE80211_SCAN_BGSCAN) == 0)
-		scandone = 1;
-
-	IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
-	    "%s: %s, [ticks %u, dwell min %lu scanend %lu]\n",
-	    __func__, scandone ? "done" : "stopped",
-	    ticks, ss->ss_mindwell, scanend);
 
-	/*
-	 * Clear the SCAN bit first in case frames are
-	 * pending on the station power save queue.  If
-	 * we defer this then the dispatch of the frames
-	 * may generate a request to cancel scanning.
-	 */
-done:
-	ic->ic_flags &= ~IEEE80211_F_SCAN;
-	/*
-	 * Drop out of power save mode when a scan has
-	 * completed.  If this scan was prematurely terminated
-	 * because it is a background scan then don't notify
-	 * the ap; we'll either return to scanning after we
-	 * receive the beacon frame or we'll drop out of power
-	 * save mode because the beacon indicates we have frames
-	 * waiting for us.
-	 */
-	if (scandone) {
-		ieee80211_sta_pwrsave(vap, 0);
-		if (ss->ss_next >= ss->ss_last) {
-			ieee80211_notify_scan_done(vap);
-			ic->ic_flags_ext &= ~IEEE80211_FEXT_BGSCAN;
-		}
-	}
-	SCAN_PRIVATE(ss)->ss_iflags &= ~(ISCAN_CANCEL|ISCAN_ABORT);
-	ss->ss_flags &= ~(IEEE80211_SCAN_ONCE | IEEE80211_SCAN_PICK1ST);
-	IEEE80211_UNLOCK(ic);
-#undef ISCAN_REP
+	ic->ic_scan_methods->sc_scan_probe_curchan(vap, force);
 }
 
 #ifdef IEEE80211_DEBUG
@@ -1074,16 +544,15 @@ dump_country(const uint8_t *ie)
 	printf("]");
 }
 
-static void
-dump_probe_beacon(uint8_t subtype, int isnew,
+void
+ieee80211_scan_dump_probe_beacon(uint8_t subtype, int isnew,
 	const uint8_t mac[IEEE80211_ADDR_LEN],
 	const struct ieee80211_scanparams *sp, int rssi)
 {
 
 	printf("[%s] %s%s on chan %u (bss chan %u) ",
 	    ether_sprintf(mac), isnew ? "new " : "",
-	    ieee80211_mgt_subtype_name[subtype >> IEEE80211_FC0_SUBTYPE_SHIFT],
-	    sp->chan, sp->bchan);
+	    ieee80211_mgt_subtype_name(subtype), sp->chan, sp->bchan);
 	ieee80211_print_essid(sp->ssid + 2, sp->ssid[1]);
 	printf(" rssi %d\n", rssi);
 
@@ -1102,49 +571,15 @@ dump_probe_beacon(uint8_t subtype, int isnew,
  */
 void
 ieee80211_add_scan(struct ieee80211vap *vap,
+	struct ieee80211_channel *curchan,
 	const struct ieee80211_scanparams *sp,
 	const struct ieee80211_frame *wh,
 	int subtype, int rssi, int noise)
 {
 	struct ieee80211com *ic = vap->iv_ic;
-	struct ieee80211_scan_state *ss = ic->ic_scan;
 
-	/* XXX locking */
-	/*
-	 * Frames received during startup are discarded to avoid
-	 * using scan state setup on the initial entry to the timer
-	 * callback.  This can occur because the device may enable
-	 * rx prior to our doing the initial channel change in the
-	 * timer routine.
-	 */
-	if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_DISCARD)
-		return;
-#ifdef IEEE80211_DEBUG
-	if (ieee80211_msg_scan(vap) && (ic->ic_flags & IEEE80211_F_SCAN))
-		dump_probe_beacon(subtype, 1, wh->i_addr2, sp, rssi);
-#endif
-	if (ss->ss_ops != NULL &&
-	    ss->ss_ops->scan_add(ss, sp, wh, subtype, rssi, noise)) {
-		/*
-		 * If we've reached the min dwell time terminate
-		 * the timer so we'll switch to the next channel.
-		 */
-		if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_MINDWELL) == 0 &&
-		    time_after_eq(ticks, SCAN_PRIVATE(ss)->ss_chanmindwell)) {
-			IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
-			    "%s: chan %3d%c min dwell met (%u > %lu)\n",
-			    __func__,
-			    ieee80211_chan2ieee(ic, ic->ic_curchan),
-				channel_type(ic->ic_curchan),
-			    ticks, SCAN_PRIVATE(ss)->ss_chanmindwell);
-			SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_MINDWELL;
-			/*
-			 * NB: trigger at next clock tick or wait for the
-			 * hardware.
-			 */
-			ic->ic_scan_mindwell(ss);
-		}
-	}
+	return (ic->ic_scan_methods->sc_add_scan(vap, curchan, sp, wh, subtype,
+	    rssi, noise));
 }
 
 /*