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 */ 22 static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata) 23 { 24 struct ieee80211_local *local = sdata->local; 25 26 local->offchannel_ps_enabled = false; 27 28 /* FIXME: what to do when local->pspolling is true? */ 29 30 del_timer_sync(&local->dynamic_ps_timer); 31 cancel_work_sync(&local->dynamic_ps_enable_work); 32 33 if (local->hw.conf.flags & IEEE80211_CONF_PS) { 34 local->offchannel_ps_enabled = true; 35 local->hw.conf.flags &= ~IEEE80211_CONF_PS; 36 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); 37 } 38 39 if (!(local->offchannel_ps_enabled) || 40 !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)) 41 /* 42 * If power save was enabled, no need to send a nullfunc 43 * frame because AP knows that we are sleeping. But if the 44 * hardware is creating the nullfunc frame for power save 45 * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not 46 * enabled) and power save was enabled, the firmware just 47 * sent a null frame with power save disabled. So we need 48 * to send a new nullfunc frame to inform the AP that we 49 * are again sleeping. 50 */ 51 ieee80211_send_nullfunc(local, sdata, 1); 52 } 53 54 /* inform AP that we are awake again, unless power save is enabled */ 55 static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata) 56 { 57 struct ieee80211_local *local = sdata->local; 58 59 if (!local->ps_sdata) 60 ieee80211_send_nullfunc(local, sdata, 0); 61 else if (local->offchannel_ps_enabled) { 62 /* 63 * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware 64 * will send a nullfunc frame with the powersave bit set 65 * even though the AP already knows that we are sleeping. 66 * This could be avoided by sending a null frame with power 67 * save bit disabled before enabling the power save, but 68 * this doesn't gain anything. 69 * 70 * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need 71 * to send a nullfunc frame because AP already knows that 72 * we are sleeping, let's just enable power save mode in 73 * hardware. 74 */ 75 local->hw.conf.flags |= IEEE80211_CONF_PS; 76 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); 77 } else if (local->hw.conf.dynamic_ps_timeout > 0) { 78 /* 79 * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer 80 * had been running before leaving the operating channel, 81 * restart the timer now and send a nullfunc frame to inform 82 * the AP that we are awake. 83 */ 84 ieee80211_send_nullfunc(local, sdata, 0); 85 mod_timer(&local->dynamic_ps_timer, jiffies + 86 msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout)); 87 } 88 } 89 90 void ieee80211_offchannel_stop_beaconing(struct ieee80211_local *local) 91 { 92 struct ieee80211_sub_if_data *sdata; 93 94 mutex_lock(&local->iflist_mtx); 95 list_for_each_entry(sdata, &local->interfaces, list) { 96 if (!ieee80211_sdata_running(sdata)) 97 continue; 98 99 /* disable beaconing */ 100 if (sdata->vif.type == NL80211_IFTYPE_AP || 101 sdata->vif.type == NL80211_IFTYPE_ADHOC || 102 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 103 ieee80211_bss_info_change_notify( 104 sdata, BSS_CHANGED_BEACON_ENABLED); 105 106 /* 107 * only handle non-STA interfaces here, STA interfaces 108 * are handled in ieee80211_offchannel_stop_station(), 109 * e.g., from the background scan state machine. 110 * 111 * In addition, do not stop monitor interface to allow it to be 112 * used from user space controlled off-channel operations. 113 */ 114 if (sdata->vif.type != NL80211_IFTYPE_STATION && 115 sdata->vif.type != NL80211_IFTYPE_MONITOR) 116 netif_tx_stop_all_queues(sdata->dev); 117 } 118 mutex_unlock(&local->iflist_mtx); 119 } 120 121 void ieee80211_offchannel_stop_station(struct ieee80211_local *local) 122 { 123 struct ieee80211_sub_if_data *sdata; 124 125 /* 126 * notify the AP about us leaving the channel and stop all STA interfaces 127 */ 128 mutex_lock(&local->iflist_mtx); 129 list_for_each_entry(sdata, &local->interfaces, list) { 130 if (!ieee80211_sdata_running(sdata)) 131 continue; 132 133 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 134 netif_tx_stop_all_queues(sdata->dev); 135 if (sdata->u.mgd.associated) 136 ieee80211_offchannel_ps_enable(sdata); 137 } 138 } 139 mutex_unlock(&local->iflist_mtx); 140 } 141 142 void ieee80211_offchannel_return(struct ieee80211_local *local, 143 bool enable_beaconing) 144 { 145 struct ieee80211_sub_if_data *sdata; 146 147 mutex_lock(&local->iflist_mtx); 148 list_for_each_entry(sdata, &local->interfaces, list) { 149 if (!ieee80211_sdata_running(sdata)) 150 continue; 151 152 /* Tell AP we're back */ 153 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 154 if (sdata->u.mgd.associated) 155 ieee80211_offchannel_ps_disable(sdata); 156 } 157 158 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) 159 netif_tx_wake_all_queues(sdata->dev); 160 161 /* re-enable beaconing */ 162 if (enable_beaconing && 163 (sdata->vif.type == NL80211_IFTYPE_AP || 164 sdata->vif.type == NL80211_IFTYPE_ADHOC || 165 sdata->vif.type == NL80211_IFTYPE_MESH_POINT)) 166 ieee80211_bss_info_change_notify( 167 sdata, BSS_CHANGED_BEACON_ENABLED); 168 } 169 mutex_unlock(&local->iflist_mtx); 170 } 171