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 <linux/export.h> 16 #include <net/mac80211.h> 17 #include "ieee80211_i.h" 18 #include "driver-trace.h" 19 20 /* 21 * Tell our hardware to disable PS. 22 * Optionally inform AP that we will go to sleep so that it will buffer 23 * the frames while we are doing off-channel work. This is optional 24 * because we *may* be doing work on-operating channel, and want our 25 * hardware unconditionally awake, but still let the AP send us normal frames. 26 */ 27 static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata, 28 bool tell_ap) 29 { 30 struct ieee80211_local *local = sdata->local; 31 struct ieee80211_if_managed *ifmgd = &sdata->u.mgd; 32 33 local->offchannel_ps_enabled = false; 34 35 /* FIXME: what to do when local->pspolling is true? */ 36 37 del_timer_sync(&local->dynamic_ps_timer); 38 del_timer_sync(&ifmgd->bcn_mon_timer); 39 del_timer_sync(&ifmgd->conn_mon_timer); 40 41 cancel_work_sync(&local->dynamic_ps_enable_work); 42 43 if (local->hw.conf.flags & IEEE80211_CONF_PS) { 44 local->offchannel_ps_enabled = true; 45 local->hw.conf.flags &= ~IEEE80211_CONF_PS; 46 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); 47 } 48 49 if (tell_ap && (!local->offchannel_ps_enabled || 50 !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))) 51 /* 52 * If power save was enabled, no need to send a nullfunc 53 * frame because AP knows that we are sleeping. But if the 54 * hardware is creating the nullfunc frame for power save 55 * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not 56 * enabled) and power save was enabled, the firmware just 57 * sent a null frame with power save disabled. So we need 58 * to send a new nullfunc frame to inform the AP that we 59 * are again sleeping. 60 */ 61 ieee80211_send_nullfunc(local, sdata, 1); 62 } 63 64 /* inform AP that we are awake again, unless power save is enabled */ 65 static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata) 66 { 67 struct ieee80211_local *local = sdata->local; 68 69 if (!local->ps_sdata) 70 ieee80211_send_nullfunc(local, sdata, 0); 71 else if (local->offchannel_ps_enabled) { 72 /* 73 * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware 74 * will send a nullfunc frame with the powersave bit set 75 * even though the AP already knows that we are sleeping. 76 * This could be avoided by sending a null frame with power 77 * save bit disabled before enabling the power save, but 78 * this doesn't gain anything. 79 * 80 * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need 81 * to send a nullfunc frame because AP already knows that 82 * we are sleeping, let's just enable power save mode in 83 * hardware. 84 */ 85 /* TODO: Only set hardware if CONF_PS changed? 86 * TODO: Should we set offchannel_ps_enabled to false? 87 */ 88 local->hw.conf.flags |= IEEE80211_CONF_PS; 89 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS); 90 } else if (local->hw.conf.dynamic_ps_timeout > 0) { 91 /* 92 * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer 93 * had been running before leaving the operating channel, 94 * restart the timer now and send a nullfunc frame to inform 95 * the AP that we are awake. 96 */ 97 ieee80211_send_nullfunc(local, sdata, 0); 98 mod_timer(&local->dynamic_ps_timer, jiffies + 99 msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout)); 100 } 101 102 ieee80211_sta_reset_beacon_monitor(sdata); 103 ieee80211_sta_reset_conn_monitor(sdata); 104 } 105 106 void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local, 107 bool offchannel_ps_enable) 108 { 109 struct ieee80211_sub_if_data *sdata; 110 111 /* 112 * notify the AP about us leaving the channel and stop all 113 * STA interfaces. 114 */ 115 mutex_lock(&local->iflist_mtx); 116 list_for_each_entry(sdata, &local->interfaces, list) { 117 if (!ieee80211_sdata_running(sdata)) 118 continue; 119 120 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) 121 set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state); 122 123 /* Check to see if we should disable beaconing. */ 124 if (sdata->vif.type == NL80211_IFTYPE_AP || 125 sdata->vif.type == NL80211_IFTYPE_ADHOC || 126 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 127 ieee80211_bss_info_change_notify( 128 sdata, BSS_CHANGED_BEACON_ENABLED); 129 130 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) { 131 netif_tx_stop_all_queues(sdata->dev); 132 if (offchannel_ps_enable && 133 (sdata->vif.type == NL80211_IFTYPE_STATION) && 134 sdata->u.mgd.associated) 135 ieee80211_offchannel_ps_enable(sdata, true); 136 } 137 } 138 mutex_unlock(&local->iflist_mtx); 139 } 140 141 void ieee80211_offchannel_return(struct ieee80211_local *local, 142 bool offchannel_ps_disable) 143 { 144 struct ieee80211_sub_if_data *sdata; 145 146 mutex_lock(&local->iflist_mtx); 147 list_for_each_entry(sdata, &local->interfaces, list) { 148 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) 149 clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state); 150 151 if (!ieee80211_sdata_running(sdata)) 152 continue; 153 154 /* Tell AP we're back */ 155 if (offchannel_ps_disable && 156 sdata->vif.type == NL80211_IFTYPE_STATION) { 157 if (sdata->u.mgd.associated) 158 ieee80211_offchannel_ps_disable(sdata); 159 } 160 161 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) { 162 /* 163 * This may wake up queues even though the driver 164 * currently has them stopped. This is not very 165 * likely, since the driver won't have gotten any 166 * (or hardly any) new packets while we weren't 167 * on the right channel, and even if it happens 168 * it will at most lead to queueing up one more 169 * packet per queue in mac80211 rather than on 170 * the interface qdisc. 171 */ 172 netif_tx_wake_all_queues(sdata->dev); 173 } 174 175 if (sdata->vif.type == NL80211_IFTYPE_AP || 176 sdata->vif.type == NL80211_IFTYPE_ADHOC || 177 sdata->vif.type == NL80211_IFTYPE_MESH_POINT) 178 ieee80211_bss_info_change_notify( 179 sdata, BSS_CHANGED_BEACON_ENABLED); 180 } 181 mutex_unlock(&local->iflist_mtx); 182 } 183 184 static void ieee80211_hw_roc_start(struct work_struct *work) 185 { 186 struct ieee80211_local *local = 187 container_of(work, struct ieee80211_local, hw_roc_start); 188 struct ieee80211_sub_if_data *sdata; 189 190 mutex_lock(&local->mtx); 191 192 if (!local->hw_roc_channel) { 193 mutex_unlock(&local->mtx); 194 return; 195 } 196 197 if (local->hw_roc_skb) { 198 sdata = IEEE80211_DEV_TO_SUB_IF(local->hw_roc_dev); 199 ieee80211_tx_skb(sdata, local->hw_roc_skb); 200 local->hw_roc_skb = NULL; 201 } else { 202 cfg80211_ready_on_channel(local->hw_roc_dev, 203 local->hw_roc_cookie, 204 local->hw_roc_channel, 205 local->hw_roc_channel_type, 206 local->hw_roc_duration, 207 GFP_KERNEL); 208 } 209 210 ieee80211_recalc_idle(local); 211 212 mutex_unlock(&local->mtx); 213 } 214 215 void ieee80211_ready_on_channel(struct ieee80211_hw *hw) 216 { 217 struct ieee80211_local *local = hw_to_local(hw); 218 219 trace_api_ready_on_channel(local); 220 221 ieee80211_queue_work(hw, &local->hw_roc_start); 222 } 223 EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel); 224 225 static void ieee80211_hw_roc_done(struct work_struct *work) 226 { 227 struct ieee80211_local *local = 228 container_of(work, struct ieee80211_local, hw_roc_done); 229 230 mutex_lock(&local->mtx); 231 232 if (!local->hw_roc_channel) { 233 mutex_unlock(&local->mtx); 234 return; 235 } 236 237 if (!local->hw_roc_for_tx) 238 cfg80211_remain_on_channel_expired(local->hw_roc_dev, 239 local->hw_roc_cookie, 240 local->hw_roc_channel, 241 local->hw_roc_channel_type, 242 GFP_KERNEL); 243 244 local->hw_roc_channel = NULL; 245 local->hw_roc_cookie = 0; 246 247 ieee80211_recalc_idle(local); 248 249 mutex_unlock(&local->mtx); 250 } 251 252 void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw) 253 { 254 struct ieee80211_local *local = hw_to_local(hw); 255 256 trace_api_remain_on_channel_expired(local); 257 258 ieee80211_queue_work(hw, &local->hw_roc_done); 259 } 260 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired); 261 262 void ieee80211_hw_roc_setup(struct ieee80211_local *local) 263 { 264 INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start); 265 INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done); 266 } 267