diff options
Diffstat (limited to 'net/mac80211/offchannel.c')
| -rw-r--r-- | net/mac80211/offchannel.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/net/mac80211/offchannel.c b/net/mac80211/offchannel.c new file mode 100644 index 000000000000..1facfeb1f79b --- /dev/null +++ b/net/mac80211/offchannel.c @@ -0,0 +1,168 @@ +/* + * 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. + * + * In addition, do not stop monitor interface to allow it to be + * used from user space controlled off-channel operations. + */ + if (sdata->vif.type != NL80211_IFTYPE_STATION && + sdata->vif.type != NL80211_IFTYPE_MONITOR) + netif_tx_stop_all_queues(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_tx_stop_all_queues(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_tx_wake_all_queues(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); +} |