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 * Tell our hardware to disable PS. 21 * Optionally inform AP that we will go to sleep so that it will buffer 22 * the frames while we are doing off-channel work. This is optional 23 * because we *may* be doing work on-operating channel, and want our 24 * hardware unconditionally awake, but still let the AP send us normal frames. 25 */ 26 static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata, 27 bool tell_ap) 28 { 29 struct ieee80211_local *local = sdata->local; 30 struct ieee80211_if_managed *ifmgd = &sdata->u.mgd; 31 32 local->offchannel_ps_enabled = false; 33 34 /* FIXME: what to do when local->pspolling is true? */ 35 36 del_timer_sync(&local->dynamic_ps_timer); 37 del_timer_sync(&ifmgd->bcn_mon_timer); 38 del_timer_sync(&ifmgd->conn_mon_timer); 39 40 cancel_work_sync(&local->dynamic_ps_enable_work); 41 42 if (local->hw.conf.flags & IEEE80211_CONF_PS) { 43 local->offchannel_ps_enabled = true; 44 local->hw.conf.flags &= ~IEEE80211_CONF_PS; 45 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); 46 } 47 48 if (tell_ap && (!local->offchannel_ps_enabled || 49 !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))) 50 /* 51 * If power save was enabled, no need to send a nullfunc 52 * frame because AP knows that we are sleeping. But if the 53 * hardware is creating the nullfunc frame for power save 54 * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not 55 * enabled) and power save was enabled, the firmware just 56 * sent a null frame with power save disabled. So we need 57 * to send a new nullfunc frame to inform the AP that we 58 * are again sleeping. 59 */ 60 ieee80211_send_nullfunc(local, sdata, 1); 61 } 62 63 /* inform AP that we are awake again, unless power save is enabled */ 64 static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata) 65 { 66 struct ieee80211_local *local = sdata->local; 67 68 if (!local->ps_sdata) 69 ieee80211_send_nullfunc(local, sdata, 0); 70 else if (local->offchannel_ps_enabled) { 71 /* 72 * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware 73 * will send a nullfunc frame with the powersave bit set 74 * even though the AP already knows that we are sleeping. 75 * This could be avoided by sending a null frame with power 76 * save bit disabled before enabling the power save, but 77 * this doesn't gain anything. 78 * 79 * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need 80 * to send a nullfunc frame because AP already knows that 81 * we are sleeping, let's just enable power save mode in 82 * hardware. 83 */ 84 /* TODO: Only set hardware if CONF_PS changed? 85 * TODO: Should we set offchannel_ps_enabled to false? 86 */ 87 local->hw.conf.flags |= IEEE80211_CONF_PS; 88 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); 89 } else if (local->hw.conf.dynamic_ps_timeout > 0) { 90 /* 91 * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer 92 * had been running before leaving the operating channel, 93 * restart the timer now and send a nullfunc frame to inform 94 * the AP that we are awake. 95 */ 96 ieee80211_send_nullfunc(local, sdata, 0); 97 mod_timer(&local->dynamic_ps_timer, jiffies + 98 msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout)); 99 } 100 101 ieee80211_sta_reset_beacon_monitor(sdata); 102 ieee80211_sta_reset_conn_monitor(sdata); 103 } 104 105 void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local, 106 bool offchannel_ps_enable) 107 { 108 struct ieee80211_sub_if_data *sdata; 109 110 /* 111 * notify the AP about us leaving the channel and stop all 112 * STA interfaces. 113 */ 114 mutex_lock(&local->iflist_mtx); 115 list_for_each_entry(sdata, &local->interfaces, list) { 116 if (!ieee80211_sdata_running(sdata)) 117 continue; 118 119 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) 120 set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state); 121 122 /* Check to see if we should disable beaconing. */ 123 if (sdata->vif.type == NL80211_IFTYPE_AP || 124 sdata->vif.type == NL80211_IFTYPE_ADHOC || 125 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 126 ieee80211_bss_info_change_notify( 127 sdata, BSS_CHANGED_BEACON_ENABLED); 128 129 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) { 130 netif_tx_stop_all_queues(sdata->dev); 131 if (offchannel_ps_enable && 132 (sdata->vif.type == NL80211_IFTYPE_STATION) && 133 sdata->u.mgd.associated) 134 ieee80211_offchannel_ps_enable(sdata, true); 135 } 136 } 137 mutex_unlock(&local->iflist_mtx); 138 } 139 140 void ieee80211_offchannel_enable_all_ps(struct ieee80211_local *local, 141 bool tell_ap) 142 { 143 struct ieee80211_sub_if_data *sdata; 144 145 mutex_lock(&local->iflist_mtx); 146 list_for_each_entry(sdata, &local->interfaces, list) { 147 if (!ieee80211_sdata_running(sdata)) 148 continue; 149 150 if (sdata->vif.type == NL80211_IFTYPE_STATION && 151 sdata->u.mgd.associated) 152 ieee80211_offchannel_ps_enable(sdata, tell_ap); 153 } 154 mutex_unlock(&local->iflist_mtx); 155 } 156 157 void ieee80211_offchannel_return(struct ieee80211_local *local, 158 bool enable_beaconing, 159 bool offchannel_ps_disable) 160 { 161 struct ieee80211_sub_if_data *sdata; 162 163 mutex_lock(&local->iflist_mtx); 164 list_for_each_entry(sdata, &local->interfaces, list) { 165 if (!ieee80211_sdata_running(sdata)) 166 continue; 167 168 /* Tell AP we're back */ 169 if (offchannel_ps_disable && 170 sdata->vif.type == NL80211_IFTYPE_STATION) { 171 if (sdata->u.mgd.associated) 172 ieee80211_offchannel_ps_disable(sdata); 173 } 174 175 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) { 176 clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state); 177 /* 178 * This may wake up queues even though the driver 179 * currently has them stopped. This is not very 180 * likely, since the driver won't have gotten any 181 * (or hardly any) new packets while we weren't 182 * on the right channel, and even if it happens 183 * it will at most lead to queueing up one more 184 * packet per queue in mac80211 rather than on 185 * the interface qdisc. 186 */ 187 netif_tx_wake_all_queues(sdata->dev); 188 } 189 190 /* Check to see if we should re-enable beaconing */ 191 if (enable_beaconing && 192 (sdata->vif.type == NL80211_IFTYPE_AP || 193 sdata->vif.type == NL80211_IFTYPE_ADHOC || 194 sdata->vif.type == NL80211_IFTYPE_MESH_POINT)) 195 ieee80211_bss_info_change_notify( 196 sdata, BSS_CHANGED_BEACON_ENABLED); 197 } 198 mutex_unlock(&local->iflist_mtx); 199 } 200 201 static void ieee80211_hw_roc_start(struct work_struct *work) 202 { 203 struct ieee80211_local *local = 204 container_of(work, struct ieee80211_local, hw_roc_start); 205 struct ieee80211_sub_if_data *sdata; 206 207 mutex_lock(&local->mtx); 208 209 if (!local->hw_roc_channel) { 210 mutex_unlock(&local->mtx); 211 return; 212 } 213 214 ieee80211_recalc_idle(local); 215 216 if (local->hw_roc_skb) { 217 sdata = IEEE80211_DEV_TO_SUB_IF(local->hw_roc_dev); 218 ieee80211_tx_skb(sdata, local->hw_roc_skb); 219 local->hw_roc_skb = NULL; 220 } else { 221 cfg80211_ready_on_channel(local->hw_roc_dev, 222 local->hw_roc_cookie, 223 local->hw_roc_channel, 224 local->hw_roc_channel_type, 225 local->hw_roc_duration, 226 GFP_KERNEL); 227 } 228 229 mutex_unlock(&local->mtx); 230 } 231 232 void ieee80211_ready_on_channel(struct ieee80211_hw *hw) 233 { 234 struct ieee80211_local *local = hw_to_local(hw); 235 236 trace_api_ready_on_channel(local); 237 238 ieee80211_queue_work(hw, &local->hw_roc_start); 239 } 240 EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel); 241 242 static void ieee80211_hw_roc_done(struct work_struct *work) 243 { 244 struct ieee80211_local *local = 245 container_of(work, struct ieee80211_local, hw_roc_done); 246 247 mutex_lock(&local->mtx); 248 249 if (!local->hw_roc_channel) { 250 mutex_unlock(&local->mtx); 251 return; 252 } 253 254 if (!local->hw_roc_for_tx) 255 cfg80211_remain_on_channel_expired(local->hw_roc_dev, 256 local->hw_roc_cookie, 257 local->hw_roc_channel, 258 local->hw_roc_channel_type, 259 GFP_KERNEL); 260 261 local->hw_roc_channel = NULL; 262 local->hw_roc_cookie = 0; 263 264 ieee80211_recalc_idle(local); 265 266 mutex_unlock(&local->mtx); 267 } 268 269 void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw) 270 { 271 struct ieee80211_local *local = hw_to_local(hw); 272 273 trace_api_remain_on_channel_expired(local); 274 275 ieee80211_queue_work(hw, &local->hw_roc_done); 276 } 277 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired); 278 279 void ieee80211_hw_roc_setup(struct ieee80211_local *local) 280 { 281 INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start); 282 INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done); 283 } 284