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 #include "driver-trace.h" 18 19 /* 20 * inform AP that we will go to sleep so that it will buffer the frames 21 * while we scan 22 */ 23 static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata) 24 { 25 struct ieee80211_local *local = sdata->local; 26 struct ieee80211_if_managed *ifmgd = &sdata->u.mgd; 27 28 local->offchannel_ps_enabled = false; 29 30 /* FIXME: what to do when local->pspolling is true? */ 31 32 del_timer_sync(&local->dynamic_ps_timer); 33 del_timer_sync(&ifmgd->bcn_mon_timer); 34 del_timer_sync(&ifmgd->conn_mon_timer); 35 36 cancel_work_sync(&local->dynamic_ps_enable_work); 37 38 if (local->hw.conf.flags & IEEE80211_CONF_PS) { 39 local->offchannel_ps_enabled = true; 40 local->hw.conf.flags &= ~IEEE80211_CONF_PS; 41 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); 42 } 43 44 if (!(local->offchannel_ps_enabled) || 45 !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)) 46 /* 47 * If power save was enabled, no need to send a nullfunc 48 * frame because AP knows that we are sleeping. But if the 49 * hardware is creating the nullfunc frame for power save 50 * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not 51 * enabled) and power save was enabled, the firmware just 52 * sent a null frame with power save disabled. So we need 53 * to send a new nullfunc frame to inform the AP that we 54 * are again sleeping. 55 */ 56 ieee80211_send_nullfunc(local, sdata, 1); 57 } 58 59 /* inform AP that we are awake again, unless power save is enabled */ 60 static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata) 61 { 62 struct ieee80211_local *local = sdata->local; 63 64 if (!local->ps_sdata) 65 ieee80211_send_nullfunc(local, sdata, 0); 66 else if (local->offchannel_ps_enabled) { 67 /* 68 * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware 69 * will send a nullfunc frame with the powersave bit set 70 * even though the AP already knows that we are sleeping. 71 * This could be avoided by sending a null frame with power 72 * save bit disabled before enabling the power save, but 73 * this doesn't gain anything. 74 * 75 * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need 76 * to send a nullfunc frame because AP already knows that 77 * we are sleeping, let's just enable power save mode in 78 * hardware. 79 */ 80 local->hw.conf.flags |= IEEE80211_CONF_PS; 81 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); 82 } else if (local->hw.conf.dynamic_ps_timeout > 0) { 83 /* 84 * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer 85 * had been running before leaving the operating channel, 86 * restart the timer now and send a nullfunc frame to inform 87 * the AP that we are awake. 88 */ 89 ieee80211_send_nullfunc(local, sdata, 0); 90 mod_timer(&local->dynamic_ps_timer, jiffies + 91 msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout)); 92 } 93 94 ieee80211_sta_reset_beacon_monitor(sdata); 95 ieee80211_sta_reset_conn_monitor(sdata); 96 } 97 98 void ieee80211_offchannel_stop_beaconing(struct ieee80211_local *local) 99 { 100 struct ieee80211_sub_if_data *sdata; 101 102 mutex_lock(&local->iflist_mtx); 103 list_for_each_entry(sdata, &local->interfaces, list) { 104 if (!ieee80211_sdata_running(sdata)) 105 continue; 106 107 /* disable beaconing */ 108 if (sdata->vif.type == NL80211_IFTYPE_AP || 109 sdata->vif.type == NL80211_IFTYPE_ADHOC || 110 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 111 ieee80211_bss_info_change_notify( 112 sdata, BSS_CHANGED_BEACON_ENABLED); 113 114 /* 115 * only handle non-STA interfaces here, STA interfaces 116 * are handled in ieee80211_offchannel_stop_station(), 117 * e.g., from the background scan state machine. 118 * 119 * In addition, do not stop monitor interface to allow it to be 120 * used from user space controlled off-channel operations. 121 */ 122 if (sdata->vif.type != NL80211_IFTYPE_STATION && 123 sdata->vif.type != NL80211_IFTYPE_MONITOR) { 124 set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state); 125 netif_tx_stop_all_queues(sdata->dev); 126 } 127 } 128 mutex_unlock(&local->iflist_mtx); 129 } 130 131 void ieee80211_offchannel_stop_station(struct ieee80211_local *local) 132 { 133 struct ieee80211_sub_if_data *sdata; 134 135 /* 136 * notify the AP about us leaving the channel and stop all STA interfaces 137 */ 138 mutex_lock(&local->iflist_mtx); 139 list_for_each_entry(sdata, &local->interfaces, list) { 140 if (!ieee80211_sdata_running(sdata)) 141 continue; 142 143 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 144 set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state); 145 netif_tx_stop_all_queues(sdata->dev); 146 if (sdata->u.mgd.associated) 147 ieee80211_offchannel_ps_enable(sdata); 148 } 149 } 150 mutex_unlock(&local->iflist_mtx); 151 } 152 153 void ieee80211_offchannel_return(struct ieee80211_local *local, 154 bool enable_beaconing) 155 { 156 struct ieee80211_sub_if_data *sdata; 157 158 mutex_lock(&local->iflist_mtx); 159 list_for_each_entry(sdata, &local->interfaces, list) { 160 if (!ieee80211_sdata_running(sdata)) 161 continue; 162 163 /* Tell AP we're back */ 164 if (sdata->vif.type == NL80211_IFTYPE_STATION) { 165 if (sdata->u.mgd.associated) 166 ieee80211_offchannel_ps_disable(sdata); 167 } 168 169 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) { 170 clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state); 171 /* 172 * This may wake up queues even though the driver 173 * currently has them stopped. This is not very 174 * likely, since the driver won't have gotten any 175 * (or hardly any) new packets while we weren't 176 * on the right channel, and even if it happens 177 * it will at most lead to queueing up one more 178 * packet per queue in mac80211 rather than on 179 * the interface qdisc. 180 */ 181 netif_tx_wake_all_queues(sdata->dev); 182 } 183 184 /* re-enable beaconing */ 185 if (enable_beaconing && 186 (sdata->vif.type == NL80211_IFTYPE_AP || 187 sdata->vif.type == NL80211_IFTYPE_ADHOC || 188 sdata->vif.type == NL80211_IFTYPE_MESH_POINT)) 189 ieee80211_bss_info_change_notify( 190 sdata, BSS_CHANGED_BEACON_ENABLED); 191 } 192 mutex_unlock(&local->iflist_mtx); 193 } 194 195 static void ieee80211_hw_roc_start(struct work_struct *work) 196 { 197 struct ieee80211_local *local = 198 container_of(work, struct ieee80211_local, hw_roc_start); 199 struct ieee80211_sub_if_data *sdata; 200 201 mutex_lock(&local->mtx); 202 203 if (!local->hw_roc_channel) { 204 mutex_unlock(&local->mtx); 205 return; 206 } 207 208 ieee80211_recalc_idle(local); 209 210 if (local->hw_roc_skb) { 211 sdata = IEEE80211_DEV_TO_SUB_IF(local->hw_roc_dev); 212 ieee80211_tx_skb(sdata, local->hw_roc_skb); 213 local->hw_roc_skb = NULL; 214 } else { 215 cfg80211_ready_on_channel(local->hw_roc_dev, 216 local->hw_roc_cookie, 217 local->hw_roc_channel, 218 local->hw_roc_channel_type, 219 local->hw_roc_duration, 220 GFP_KERNEL); 221 } 222 223 mutex_unlock(&local->mtx); 224 } 225 226 void ieee80211_ready_on_channel(struct ieee80211_hw *hw) 227 { 228 struct ieee80211_local *local = hw_to_local(hw); 229 230 trace_api_ready_on_channel(local); 231 232 ieee80211_queue_work(hw, &local->hw_roc_start); 233 } 234 EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel); 235 236 static void ieee80211_hw_roc_done(struct work_struct *work) 237 { 238 struct ieee80211_local *local = 239 container_of(work, struct ieee80211_local, hw_roc_done); 240 241 mutex_lock(&local->mtx); 242 243 if (!local->hw_roc_channel) { 244 mutex_unlock(&local->mtx); 245 return; 246 } 247 248 if (!local->hw_roc_for_tx) 249 cfg80211_remain_on_channel_expired(local->hw_roc_dev, 250 local->hw_roc_cookie, 251 local->hw_roc_channel, 252 local->hw_roc_channel_type, 253 GFP_KERNEL); 254 255 local->hw_roc_channel = NULL; 256 local->hw_roc_cookie = 0; 257 258 ieee80211_recalc_idle(local); 259 260 mutex_unlock(&local->mtx); 261 } 262 263 void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw) 264 { 265 struct ieee80211_local *local = hw_to_local(hw); 266 267 trace_api_remain_on_channel_expired(local); 268 269 ieee80211_queue_work(hw, &local->hw_roc_done); 270 } 271 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired); 272 273 void ieee80211_hw_roc_setup(struct ieee80211_local *local) 274 { 275 INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start); 276 INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done); 277 } 278