mac80211: Generalize off-channel operation helpers from scan code

The off-channel operations for going into power save mode (station
mode) or stop beaconing (AP/IBSS) are not limited to scanning. Move
these into a separate file and allow them to be used for other
purposes, too.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

4 files changed, 178 insertions, 152 deletions

diff --git a/net/mac80211/Makefile b/net/mac80211/Makefile
index 5a1f57df7cd6..04420291e7ad 100644
--- a/net/mac80211/Makefile
+++ b/net/mac80211/Makefile
@@ -6,7 +6,7 @@ mac80211-y := \
         sta_info.o \
         wep.o \
         wpa.o \
-        scan.o \
+        scan.o offchannel.o \
         ht.o agg-tx.o agg-rx.o \
         ibss.o \
         mlme.o work.o \
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index de068ad6223b..fd912eb5309e 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -786,7 +786,7 @@ struct ieee80211_local {
         unsigned int wmm_acm; /* bit field of ACM bits (BIT(802.1D tag)) */
 
         bool pspolling;
-        bool scan_ps_enabled;
+        bool offchannel_ps_enabled;
         /*
          * PS can only be enabled when we have exactly one managed
          * interface (and monitors) in PS, this then points there.
@@ -981,6 +981,12 @@ ieee80211_rx_bss_get(struct ieee80211_local *local, u8 *bssid, int freq,
 void ieee80211_rx_bss_put(struct ieee80211_local *local,
                           struct ieee80211_bss *bss);
 
+/* off-channel helpers */
+void ieee80211_offchannel_stop_beaconing(struct ieee80211_local *local);
+void ieee80211_offchannel_stop_station(struct ieee80211_local *local);
+void ieee80211_offchannel_return(struct ieee80211_local *local,
+                                 bool enable_beaconing);
+
 /* interface handling */
 int ieee80211_iface_init(void);
 void ieee80211_iface_exit(void);
diff --git a/net/mac80211/offchannel.c b/net/mac80211/offchannel.c
new file mode 100644
index 000000000000..2cd880e444d1
--- /dev/null
+++ b/net/mac80211/offchannel.c
@@ -0,0 +1,164 @@
+/*
+ * Off-channel operation helpers
+ *
+ * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
+ * Copyright 2004, Instant802 Networks, Inc.
+ * Copyright 2005, Devicescape Software, Inc.
+ * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
+ * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
+ * Copyright 2009       Johannes Berg <johannes@sipsolutions.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <net/mac80211.h>
+#include "ieee80211_i.h"
+
+/*
+ * inform AP that we will go to sleep so that it will buffer the frames
+ * while we scan
+ */
+static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata)
+{
+        struct ieee80211_local *local = sdata->local;
+
+        local->offchannel_ps_enabled = false;
+
+        /* FIXME: what to do when local->pspolling is true? */
+
+        del_timer_sync(&local->dynamic_ps_timer);
+        cancel_work_sync(&local->dynamic_ps_enable_work);
+
+        if (local->hw.conf.flags & IEEE80211_CONF_PS) {
+                local->offchannel_ps_enabled = true;
+                local->hw.conf.flags &= ~IEEE80211_CONF_PS;
+                ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
+        }
+
+        if (!(local->offchannel_ps_enabled) ||
+            !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))
+                /*
+                 * If power save was enabled, no need to send a nullfunc
+                 * frame because AP knows that we are sleeping. But if the
+                 * hardware is creating the nullfunc frame for power save
+                 * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
+                 * enabled) and power save was enabled, the firmware just
+                 * sent a null frame with power save disabled. So we need
+                 * to send a new nullfunc frame to inform the AP that we
+                 * are again sleeping.
+                 */
+                ieee80211_send_nullfunc(local, sdata, 1);
+}
+
+/* inform AP that we are awake again, unless power save is enabled */
+static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata)
+{
+        struct ieee80211_local *local = sdata->local;
+
+        if (!local->ps_sdata)
+                ieee80211_send_nullfunc(local, sdata, 0);
+        else if (local->offchannel_ps_enabled) {
+                /*
+                 * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
+                 * will send a nullfunc frame with the powersave bit set
+                 * even though the AP already knows that we are sleeping.
+                 * This could be avoided by sending a null frame with power
+                 * save bit disabled before enabling the power save, but
+                 * this doesn't gain anything.
+                 *
+                 * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need
+                 * to send a nullfunc frame because AP already knows that
+                 * we are sleeping, let's just enable power save mode in
+                 * hardware.
+                 */
+                local->hw.conf.flags |= IEEE80211_CONF_PS;
+                ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
+        } else if (local->hw.conf.dynamic_ps_timeout > 0) {
+                /*
+                 * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer
+                 * had been running before leaving the operating channel,
+                 * restart the timer now and send a nullfunc frame to inform
+                 * the AP that we are awake.
+                 */
+                ieee80211_send_nullfunc(local, sdata, 0);
+                mod_timer(&local->dynamic_ps_timer, jiffies +
+                          msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
+        }
+}
+
+void ieee80211_offchannel_stop_beaconing(struct ieee80211_local *local)
+{
+        struct ieee80211_sub_if_data *sdata;
+
+        mutex_lock(&local->iflist_mtx);
+        list_for_each_entry(sdata, &local->interfaces, list) {
+                if (!ieee80211_sdata_running(sdata))
+                        continue;
+
+                /* disable beaconing */
+                if (sdata->vif.type == NL80211_IFTYPE_AP ||
+                    sdata->vif.type == NL80211_IFTYPE_ADHOC ||
+                    sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
+                        ieee80211_bss_info_change_notify(
+                                sdata, BSS_CHANGED_BEACON_ENABLED);
+
+                /*
+                 * only handle non-STA interfaces here, STA interfaces
+                 * are handled in ieee80211_offchannel_stop_station(),
+                 * e.g., from the background scan state machine
+                 */
+                if (sdata->vif.type != NL80211_IFTYPE_STATION)
+                        netif_stop_queue(sdata->dev);
+        }
+        mutex_unlock(&local->iflist_mtx);
+}
+
+void ieee80211_offchannel_stop_station(struct ieee80211_local *local)
+{
+        struct ieee80211_sub_if_data *sdata;
+
+        /*
+         * notify the AP about us leaving the channel and stop all STA interfaces
+         */
+        mutex_lock(&local->iflist_mtx);
+        list_for_each_entry(sdata, &local->interfaces, list) {
+                if (!ieee80211_sdata_running(sdata))
+                        continue;
+
+                if (sdata->vif.type == NL80211_IFTYPE_STATION) {
+                        netif_stop_queue(sdata->dev);
+                        if (sdata->u.mgd.associated)
+                                ieee80211_offchannel_ps_enable(sdata);
+                }
+        }
+        mutex_unlock(&local->iflist_mtx);
+}
+
+void ieee80211_offchannel_return(struct ieee80211_local *local,
+                                 bool enable_beaconing)
+{
+        struct ieee80211_sub_if_data *sdata;
+
+        mutex_lock(&local->iflist_mtx);
+        list_for_each_entry(sdata, &local->interfaces, list) {
+                if (!ieee80211_sdata_running(sdata))
+                        continue;
+
+                /* Tell AP we're back */
+                if (sdata->vif.type == NL80211_IFTYPE_STATION) {
+                        if (sdata->u.mgd.associated)
+                                ieee80211_offchannel_ps_disable(sdata);
+                        netif_wake_queue(sdata->dev);
+                }
+
+                /* re-enable beaconing */
+                if (enable_beaconing &&
+                    (sdata->vif.type == NL80211_IFTYPE_AP ||
+                     sdata->vif.type == NL80211_IFTYPE_ADHOC ||
+                     sdata->vif.type == NL80211_IFTYPE_MESH_POINT))
+                        ieee80211_bss_info_change_notify(
+                                sdata, BSS_CHANGED_BEACON_ENABLED);
+        }
+        mutex_unlock(&local->iflist_mtx);
+}
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 2a2d7f6005af..365f40975511 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -227,82 +227,9 @@ static bool ieee80211_prep_hw_scan(struct ieee80211_local *local)
         return true;
 }
 
-/*
- * inform AP that we will go to sleep so that it will buffer the frames
- * while we scan
- */
-static void ieee80211_scan_ps_enable(struct ieee80211_sub_if_data *sdata)
-{
-        struct ieee80211_local *local = sdata->local;
-
-        local->scan_ps_enabled = false;
-
-        /* FIXME: what to do when local->pspolling is true? */
-
-        del_timer_sync(&local->dynamic_ps_timer);
-        cancel_work_sync(&local->dynamic_ps_enable_work);
-
-        if (local->hw.conf.flags & IEEE80211_CONF_PS) {
-                local->scan_ps_enabled = true;
-                local->hw.conf.flags &= ~IEEE80211_CONF_PS;
-                ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
-        }
-
-        if (!(local->scan_ps_enabled) ||
-            !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))
-                /*
-                 * If power save was enabled, no need to send a nullfunc
-                 * frame because AP knows that we are sleeping. But if the
-                 * hardware is creating the nullfunc frame for power save
-                 * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
-                 * enabled) and power save was enabled, the firmware just
-                 * sent a null frame with power save disabled. So we need
-                 * to send a new nullfunc frame to inform the AP that we
-                 * are again sleeping.
-                 */
-                ieee80211_send_nullfunc(local, sdata, 1);
-}
-
-/* inform AP that we are awake again, unless power save is enabled */
-static void ieee80211_scan_ps_disable(struct ieee80211_sub_if_data *sdata)
-{
-        struct ieee80211_local *local = sdata->local;
-
-        if (!local->ps_sdata)
-                ieee80211_send_nullfunc(local, sdata, 0);
-        else if (local->scan_ps_enabled) {
-                /*
-                 * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
-                 * will send a nullfunc frame with the powersave bit set
-                 * even though the AP already knows that we are sleeping.
-                 * This could be avoided by sending a null frame with power
-                 * save bit disabled before enabling the power save, but
-                 * this doesn't gain anything.
-                 *
-                 * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need
-                 * to send a nullfunc frame because AP already knows that
-                 * we are sleeping, let's just enable power save mode in
-                 * hardware.
-                 */
-                local->hw.conf.flags |= IEEE80211_CONF_PS;
-                ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
-        } else if (local->hw.conf.dynamic_ps_timeout > 0) {
-                /*
-                 * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer
-                 * had been running before leaving the operating channel,
-                 * restart the timer now and send a nullfunc frame to inform
-                 * the AP that we are awake.
-                 */
-                ieee80211_send_nullfunc(local, sdata, 0);
-                mod_timer(&local->dynamic_ps_timer, jiffies +
-                          msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
-        }
-}
-
 void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
 {
         struct ieee80211_local *local = hw_to_local(hw);
-        struct ieee80211_sub_if_data *sdata;
         bool was_hw_scan;
 
         mutex_lock(&local->scan_mtx);
@@ -351,28 +278,7 @@ void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted)
 
         drv_sw_scan_complete(local);
 
-        mutex_lock(&local->iflist_mtx);
-        list_for_each_entry(sdata, &local->interfaces, list) {
-                if (!ieee80211_sdata_running(sdata))
-                        continue;
-
-                /* Tell AP we're back */
-                if (sdata->vif.type == NL80211_IFTYPE_STATION) {
-                        if (sdata->u.mgd.associated) {
-                                ieee80211_scan_ps_disable(sdata);
-                                netif_wake_queue(sdata->dev);
-                        }
-                } else
-                        netif_wake_queue(sdata->dev);
-
-                /* re-enable beaconing */
-                if (sdata->vif.type == NL80211_IFTYPE_AP ||
-                    sdata->vif.type == NL80211_IFTYPE_ADHOC ||
-                    sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
-                        ieee80211_bss_info_change_notify(
-                                sdata, BSS_CHANGED_BEACON_ENABLED);
-        }
-        mutex_unlock(&local->iflist_mtx);
+        ieee80211_offchannel_return(local, true);
 
  done:
         ieee80211_recalc_idle(local);
@@ -384,8 +290,6 @@ EXPORT_SYMBOL(ieee80211_scan_completed);
 
 static int ieee80211_start_sw_scan(struct ieee80211_local *local)
 {
-        struct ieee80211_sub_if_data *sdata;
-
         /*
          * Hardware/driver doesn't support hw_scan, so use software
          * scanning instead. First send a nullfunc frame with power save
@@ -401,26 +305,7 @@ static int ieee80211_start_sw_scan(struct ieee80211_local *local)
          */
         drv_sw_scan_start(local);
 
-        mutex_lock(&local->iflist_mtx);
-        list_for_each_entry(sdata, &local->interfaces, list) {
-                if (!ieee80211_sdata_running(sdata))
-                        continue;
-
-                /* disable beaconing */
-                if (sdata->vif.type == NL80211_IFTYPE_AP ||
-                    sdata->vif.type == NL80211_IFTYPE_ADHOC ||
-                    sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
-                        ieee80211_bss_info_change_notify(
-                                sdata, BSS_CHANGED_BEACON_ENABLED);
-
-                /*
-                 * only handle non-STA interfaces here, STA interfaces
-                 * are handled in the scan state machine
-                 */
-                if (sdata->vif.type != NL80211_IFTYPE_STATION)
-                        netif_stop_queue(sdata->dev);
-        }
-        mutex_unlock(&local->iflist_mtx);
+        ieee80211_offchannel_stop_beaconing(local);
 
         local->next_scan_state = SCAN_DECISION;
         local->scan_channel_idx = 0;
@@ -568,23 +453,7 @@ static int ieee80211_scan_state_decision(struct ieee80211_local *local,
 static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *local,
                                                     unsigned long *next_delay)
 {
-        struct ieee80211_sub_if_data *sdata;
-
-        /*
-         * notify the AP about us leaving the channel and stop all STA interfaces
-         */
-        mutex_lock(&local->iflist_mtx);
-        list_for_each_entry(sdata, &local->interfaces, list) {
-                if (!ieee80211_sdata_running(sdata))
-                        continue;
-
-                if (sdata->vif.type == NL80211_IFTYPE_STATION) {
-                        netif_stop_queue(sdata->dev);
-                        if (sdata->u.mgd.associated)
-                                ieee80211_scan_ps_enable(sdata);
-                }
-        }
-        mutex_unlock(&local->iflist_mtx);
+        ieee80211_offchannel_stop_station(local);
 
         __set_bit(SCAN_OFF_CHANNEL, &local->scanning);
 
@@ -604,28 +473,15 @@ static void ieee80211_scan_state_leave_oper_channel(struct ieee80211_local *loca
 static void ieee80211_scan_state_enter_oper_channel(struct ieee80211_local *local,
                                                     unsigned long *next_delay)
 {
-        struct ieee80211_sub_if_data *sdata = local->scan_sdata;
-
         /* switch back to the operating channel */
         local->scan_channel = NULL;
         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 
         /*
-         * notify the AP about us being back and restart all STA interfaces
+         * Only re-enable station mode interface now; beaconing will be
+         * re-enabled once the full scan has been completed.
          */
-        mutex_lock(&local->iflist_mtx);
-        list_for_each_entry(sdata, &local->interfaces, list) {
-                if (!ieee80211_sdata_running(sdata))
-                        continue;
-
-                /* Tell AP we're back */
-                if (sdata->vif.type == NL80211_IFTYPE_STATION) {
-                        if (sdata->u.mgd.associated)
-                                ieee80211_scan_ps_disable(sdata);
-                        netif_wake_queue(sdata->dev);
-                }
-        }
-        mutex_unlock(&local->iflist_mtx);
+        ieee80211_offchannel_return(local, false);
 
         __clear_bit(SCAN_OFF_CHANNEL, &local->scanning);