/* * 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 <linux/export.h> #include <net/mac80211.h> #include "ieee80211_i.h" #include "driver-trace.h" /* * Tell our hardware to disable PS. * Optionally inform AP that we will go to sleep so that it will buffer * the frames while we are doing off-channel work. This is optional * because we *may* be doing work on-operating channel, and want our * hardware unconditionally awake, but still let the AP send us normal frames. */ static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata, bool tell_ap) { struct ieee80211_local *local = sdata->local; struct ieee80211_if_managed *ifmgd = &sdata->u.mgd; local->offchannel_ps_enabled = false; /* FIXME: what to do when local->pspolling is true? */ del_timer_sync(&local->dynamic_ps_timer); del_timer_sync(&ifmgd->bcn_mon_timer); del_timer_sync(&ifmgd->conn_mon_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 (tell_ap && (!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. */ /* TODO: Only set hardware if CONF_PS changed? * TODO: Should we set offchannel_ps_enabled to false? */ 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)); } ieee80211_sta_reset_beacon_monitor(sdata); ieee80211_sta_reset_conn_monitor(sdata); } void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local, bool offchannel_ps_enable) { 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_MONITOR) set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state); /* Check to see if we should 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); if (sdata->vif.type != NL80211_IFTYPE_MONITOR) { netif_tx_stop_all_queues(sdata->dev); if (offchannel_ps_enable && (sdata->vif.type == NL80211_IFTYPE_STATION) && sdata->u.mgd.associated) ieee80211_offchannel_ps_enable(sdata, true); } } mutex_unlock(&local->iflist_mtx); } void ieee80211_offchannel_return(struct ieee80211_local *local, bool offchannel_ps_disable) { struct ieee80211_sub_if_data *sdata; mutex_lock(&local->iflist_mtx); list_for_each_entry(sdata, &local->interfaces, list) { if (sdata->vif.type != NL80211_IFTYPE_MONITOR) clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state); if (!ieee80211_sdata_running(sdata)) continue; /* Tell AP we're back */ if (offchannel_ps_disable && sdata->vif.type == NL80211_IFTYPE_STATION) { if (sdata->u.mgd.associated) ieee80211_offchannel_ps_disable(sdata); } if (sdata->vif.type != NL80211_IFTYPE_MONITOR) { /* * This may wake up queues even though the driver * currently has them stopped. This is not very * likely, since the driver won't have gotten any * (or hardly any) new packets while we weren't * on the right channel, and even if it happens * it will at most lead to queueing up one more * packet per queue in mac80211 rather than on * the interface qdisc. */ netif_tx_wake_all_queues(sdata->dev); } 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); } static void ieee80211_hw_roc_start(struct work_struct *work) { struct ieee80211_local *local = container_of(work, struct ieee80211_local, hw_roc_start); struct ieee80211_sub_if_data *sdata; mutex_lock(&local->mtx); if (!local->hw_roc_channel) { mutex_unlock(&local->mtx); return; } if (local->hw_roc_skb) { sdata = IEEE80211_DEV_TO_SUB_IF(local->hw_roc_dev); ieee80211_tx_skb(sdata, local->hw_roc_skb); local->hw_roc_skb = NULL; } else { cfg80211_ready_on_channel(local->hw_roc_dev, local->hw_roc_cookie, local->hw_roc_channel, local->hw_roc_channel_type, local->hw_roc_duration, GFP_KERNEL); } ieee80211_recalc_idle(local); mutex_unlock(&local->mtx); } void ieee80211_ready_on_channel(struct ieee80211_hw *hw) { struct ieee80211_local *local = hw_to_local(hw); trace_api_ready_on_channel(local); ieee80211_queue_work(hw, &local->hw_roc_start); } EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel); static void ieee80211_hw_roc_done(struct work_struct *work) { struct ieee80211_local *local = container_of(work, struct ieee80211_local, hw_roc_done); mutex_lock(&local->mtx); if (!local->hw_roc_channel) { mutex_unlock(&local->mtx); return; } if (!local->hw_roc_for_tx) cfg80211_remain_on_channel_expired(local->hw_roc_dev, local->hw_roc_cookie, local->hw_roc_channel, local->hw_roc_channel_type, GFP_KERNEL); local->hw_roc_channel = NULL; local->hw_roc_cookie = 0; ieee80211_recalc_idle(local); mutex_unlock(&local->mtx); } void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw) { struct ieee80211_local *local = hw_to_local(hw); trace_api_remain_on_channel_expired(local); ieee80211_queue_work(hw, &local->hw_roc_done); } EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired); void ieee80211_hw_roc_setup(struct ieee80211_local *local) { INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start); INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done); }