1/* 2 * Off-channel operation helpers 3 * 4 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi> 5 * Copyright 2004, Instant802 Networks, Inc. 6 * Copyright 2005, Devicescape Software, Inc. 7 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz> 8 * Copyright 2007, Michael Wu <flamingice@sourmilk.net> 9 * Copyright 2009 Johannes Berg <johannes@sipsolutions.net> 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License version 2 as 13 * published by the Free Software Foundation. 14 */ 15#include <net/mac80211.h> 16#include "ieee80211_i.h" 17 18/* 19 * inform AP that we will go to sleep so that it will buffer the frames 20 * while we scan 21 */ 22static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata) 23{ 24 struct ieee80211_local *local = sdata->local; 25 struct ieee80211_if_managed *ifmgd = &sdata->u.mgd; 26 27 local->offchannel_ps_enabled = false; 28 29 30 del_timer_sync(&local->dynamic_ps_timer); 31 del_timer_sync(&ifmgd->bcn_mon_timer); 32 del_timer_sync(&ifmgd->conn_mon_timer); 33 34 cancel_work_sync(&local->dynamic_ps_enable_work); 35 36 if (local->hw.conf.flags & IEEE80211_CONF_PS) { 37 local->offchannel_ps_enabled = true; 38 local->hw.conf.flags &= ~IEEE80211_CONF_PS; 39 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); 40 } 41 42 if (!(local->offchannel_ps_enabled) || 43 !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)) 44 /* 45 * If power save was enabled, no need to send a nullfunc 46 * frame because AP knows that we are sleeping. But if the 47 * hardware is creating the nullfunc frame for power save 48 * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not 49 * enabled) and power save was enabled, the firmware just 50 * sent a null frame with power save disabled. So we need 51 * to send a new nullfunc frame to inform the AP that we 52 * are again sleeping. 53 */ 54 ieee80211_send_nullfunc(local, sdata, 1); 55} 56 57/* inform AP that we are awake again, unless power save is enabled */ 58static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata) 59{ 60 struct ieee80211_local *local = sdata->local; 61 62 if (!local->ps_sdata) 63 ieee80211_send_nullfunc(local, sdata, 0); 64 else if (local->offchannel_ps_enabled) { 65 /* 66 * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware 67 * will send a nullfunc frame with the powersave bit set 68 * even though the AP already knows that we are sleeping. 69 * This could be avoided by sending a null frame with power 70 * save bit disabled before enabling the power save, but 71 * this doesn't gain anything. 72 * 73 * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need 74 * to send a nullfunc frame because AP already knows that 75 * we are sleeping, let's just enable power save mode in 76 * hardware. 77 */ 78 local->hw.conf.flags |= IEEE80211_CONF_PS; 79 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); 80 } else if (local->hw.conf.dynamic_ps_timeout > 0) { 81 /* 82 * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer 83 * had been running before leaving the operating channel, 84 * restart the timer now and send a nullfunc frame to inform 85 * the AP that we are awake. 86 */ 87 ieee80211_send_nullfunc(local, sdata, 0); 88 mod_timer(&local->dynamic_ps_timer, jiffies + 89 msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout)); 90 } 91 92 ieee80211_sta_reset_beacon_monitor(sdata); 93 ieee80211_sta_reset_conn_monitor(sdata); 94} 95 96void ieee80211_offchannel_stop_beaconing(struct ieee80211_local *local) 97{ 98 struct ieee80211_sub_if_data *sdata; 99 100 mutex_lock(&local->iflist_mtx); 101 list_for_each_entry(sdata, &local->interfaces, list) { 102 if (!ieee80211_sdata_running(sdata)) 103 continue; 104 105 /* disable beaconing */ 106 if (sdata->vif.type == NL80211_IFTYPE_AP || 107 sdata->vif.type == NL80211_IFTYPE_ADHOC || 108 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 109 ieee80211_bss_info_change_notify( 110 sdata, BSS_CHANGED_BEACON_ENABLED); 111 112 /* 113 * only handle non-STA interfaces here, STA interfaces 114 * are handled in ieee80211_offchannel_stop_station(), 115 * e.g., from the background scan state machine. 116 * 117 * In addition, do not stop monitor interface to allow it to be 118 * used from user space controlled off-channel operations. 119 */ 120 if (sdata->vif.type != NL80211_IFTYPE_STATION && 121 sdata->vif.type != NL80211_IFTYPE_MONITOR) 122 netif_tx_stop_all_queues(sdata->dev); 123 } 124 mutex_unlock(&local->iflist_mtx); 125} 126 127void ieee80211_offchannel_stop_station(struct ieee80211_local *local) 128{ 129 struct ieee80211_sub_if_data *sdata; 130 131 /* 132 * notify the AP about us leaving the channel and stop all STA interfaces 133 */ 134 mutex_lock(&local->iflist_mtx); 135 list_for_each_entry(sdata, &local->interfaces, list) { 136 if (!ieee80211_sdata_running(sdata)) 137 continue; 138 139 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 140 netif_tx_stop_all_queues(sdata->dev); 141 if (sdata->u.mgd.associated) 142 ieee80211_offchannel_ps_enable(sdata); 143 } 144 } 145 mutex_unlock(&local->iflist_mtx); 146} 147 148void ieee80211_offchannel_return(struct ieee80211_local *local, 149 bool enable_beaconing) 150{ 151 struct ieee80211_sub_if_data *sdata; 152 153 mutex_lock(&local->iflist_mtx); 154 list_for_each_entry(sdata, &local->interfaces, list) { 155 if (!ieee80211_sdata_running(sdata)) 156 continue; 157 158 /* Tell AP we're back */ 159 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 160 if (sdata->u.mgd.associated) 161 ieee80211_offchannel_ps_disable(sdata); 162 } 163 164 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) 165 netif_tx_wake_all_queues(sdata->dev); 166 167 /* re-enable beaconing */ 168 if (enable_beaconing && 169 (sdata->vif.type == NL80211_IFTYPE_AP || 170 sdata->vif.type == NL80211_IFTYPE_ADHOC || 171 sdata->vif.type == NL80211_IFTYPE_MESH_POINT)) 172 ieee80211_bss_info_change_notify( 173 sdata, BSS_CHANGED_BEACON_ENABLED); 174 } 175 mutex_unlock(&local->iflist_mtx); 176} 177