offchannel.c
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00001 /*
00002  * Off-channel operation helpers
00003  *
00004  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
00005  * Copyright 2004, Instant802 Networks, Inc.
00006  * Copyright 2005, Devicescape Software, Inc.
00007  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
00008  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
00009  * Copyright 2009       Johannes Berg <johannes@sipsolutions.net>
00010  *
00011  * This program is free software; you can redistribute it and/or modify
00012  * it under the terms of the GNU General Public License version 2 as
00013  * published by the Free Software Foundation.
00014  */
00015 #include <linux/export.h>
00016 #include <net/mac80211.h>
00017 #include "ieee80211_i.h"
00018 #include "driver-trace.h"
00019 
00020 /*
00021  * Tell our hardware to disable PS.
00022  * Optionally inform AP that we will go to sleep so that it will buffer
00023  * the frames while we are doing off-channel work.  This is optional
00024  * because we *may* be doing work on-operating channel, and want our
00025  * hardware unconditionally awake, but still let the AP send us normal frames.
00026  */
00027 static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata,
00028                                            bool tell_ap)
00029 {
00030         struct ieee80211_local *local = sdata->local;
00031         struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
00032 
00033         local->offchannel_ps_enabled = false;
00034 
00035         /* FIXME: what to do when local->pspolling is true? */
00036 
00037         del_timer_sync(&local->dynamic_ps_timer);
00038         del_timer_sync(&ifmgd->bcn_mon_timer);
00039         del_timer_sync(&ifmgd->conn_mon_timer);
00040 
00041         cancel_work_sync(&local->dynamic_ps_enable_work);
00042 
00043         if (local->hw.conf.flags & IEEE80211_CONF_PS) {
00044                 local->offchannel_ps_enabled = true;
00045                 local->hw.conf.flags &= ~IEEE80211_CONF_PS;
00046                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
00047         }
00048 
00049         if (tell_ap && (!local->offchannel_ps_enabled ||
00050                         !(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK)))
00051                 /*
00052                  * If power save was enabled, no need to send a nullfunc
00053                  * frame because AP knows that we are sleeping. But if the
00054                  * hardware is creating the nullfunc frame for power save
00055                  * status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
00056                  * enabled) and power save was enabled, the firmware just
00057                  * sent a null frame with power save disabled. So we need
00058                  * to send a new nullfunc frame to inform the AP that we
00059                  * are again sleeping.
00060                  */
00061                 ieee80211_send_nullfunc(local, sdata, 1);
00062 }
00063 
00064 /* inform AP that we are awake again, unless power save is enabled */
00065 static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata)
00066 {
00067         struct ieee80211_local *local = sdata->local;
00068 
00069         if (!local->ps_sdata)
00070                 ieee80211_send_nullfunc(local, sdata, 0);
00071         else if (local->offchannel_ps_enabled) {
00072                 /*
00073                  * In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
00074                  * will send a nullfunc frame with the powersave bit set
00075                  * even though the AP already knows that we are sleeping.
00076                  * This could be avoided by sending a null frame with power
00077                  * save bit disabled before enabling the power save, but
00078                  * this doesn't gain anything.
00079                  *
00080                  * When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need
00081                  * to send a nullfunc frame because AP already knows that
00082                  * we are sleeping, let's just enable power save mode in
00083                  * hardware.
00084                  */
00085                 /* TODO:  Only set hardware if CONF_PS changed?
00086                  * TODO:  Should we set offchannel_ps_enabled to false?
00087                  */
00088                 local->hw.conf.flags |= IEEE80211_CONF_PS;
00089                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
00090         } else if (local->hw.conf.dynamic_ps_timeout > 0) {
00091                 /*
00092                  * If IEEE80211_CONF_PS was not set and the dynamic_ps_timer
00093                  * had been running before leaving the operating channel,
00094                  * restart the timer now and send a nullfunc frame to inform
00095                  * the AP that we are awake.
00096                  */
00097                 ieee80211_send_nullfunc(local, sdata, 0);
00098                 mod_timer(&local->dynamic_ps_timer, jiffies +
00099                           msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
00100         }
00101 
00102         ieee80211_sta_reset_beacon_monitor(sdata);
00103         ieee80211_sta_reset_conn_monitor(sdata);
00104 }
00105 
00106 void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local,
00107                                     bool offchannel_ps_enable)
00108 {
00109         struct ieee80211_sub_if_data *sdata;
00110 
00111         /*
00112          * notify the AP about us leaving the channel and stop all
00113          * STA interfaces.
00114          */
00115         mutex_lock(&local->iflist_mtx);
00116         list_for_each_entry(sdata, &local->interfaces, list) {
00117                 if (!ieee80211_sdata_running(sdata))
00118                         continue;
00119 
00120                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
00121                         set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
00122 
00123                 /* Check to see if we should disable beaconing. */
00124                 if (sdata->vif.type == NL80211_IFTYPE_AP ||
00125                     sdata->vif.type == NL80211_IFTYPE_ADHOC ||
00126                     sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
00127                         ieee80211_bss_info_change_notify(
00128                                 sdata, BSS_CHANGED_BEACON_ENABLED);
00129 
00130                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
00131                         netif_tx_stop_all_queues(sdata->dev);
00132                         if (offchannel_ps_enable &&
00133                             (sdata->vif.type == NL80211_IFTYPE_STATION) &&
00134                             sdata->u.mgd.associated)
00135                                 ieee80211_offchannel_ps_enable(sdata, true);
00136                 }
00137         }
00138         mutex_unlock(&local->iflist_mtx);
00139 }
00140 
00141 void ieee80211_offchannel_return(struct ieee80211_local *local,
00142                                  bool offchannel_ps_disable)
00143 {
00144         struct ieee80211_sub_if_data *sdata;
00145 
00146         mutex_lock(&local->iflist_mtx);
00147         list_for_each_entry(sdata, &local->interfaces, list) {
00148                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
00149                         clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
00150 
00151                 if (!ieee80211_sdata_running(sdata))
00152                         continue;
00153 
00154                 /* Tell AP we're back */
00155                 if (offchannel_ps_disable &&
00156                     sdata->vif.type == NL80211_IFTYPE_STATION) {
00157                         if (sdata->u.mgd.associated)
00158                                 ieee80211_offchannel_ps_disable(sdata);
00159                 }
00160 
00161                 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
00162                         /*
00163                          * This may wake up queues even though the driver
00164                          * currently has them stopped. This is not very
00165                          * likely, since the driver won't have gotten any
00166                          * (or hardly any) new packets while we weren't
00167                          * on the right channel, and even if it happens
00168                          * it will at most lead to queueing up one more
00169                          * packet per queue in mac80211 rather than on
00170                          * the interface qdisc.
00171                          */
00172                         netif_tx_wake_all_queues(sdata->dev);
00173                 }
00174 
00175                 if (sdata->vif.type == NL80211_IFTYPE_AP ||
00176                     sdata->vif.type == NL80211_IFTYPE_ADHOC ||
00177                     sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
00178                         ieee80211_bss_info_change_notify(
00179                                 sdata, BSS_CHANGED_BEACON_ENABLED);
00180         }
00181         mutex_unlock(&local->iflist_mtx);
00182 }
00183 
00184 static void ieee80211_hw_roc_start(struct work_struct *work)
00185 {
00186         struct ieee80211_local *local =
00187                 container_of(work, struct ieee80211_local, hw_roc_start);
00188         struct ieee80211_sub_if_data *sdata;
00189 
00190         mutex_lock(&local->mtx);
00191 
00192         if (!local->hw_roc_channel) {
00193                 mutex_unlock(&local->mtx);
00194                 return;
00195         }
00196 
00197         if (local->hw_roc_skb) {
00198                 sdata = IEEE80211_DEV_TO_SUB_IF(local->hw_roc_dev);
00199                 ieee80211_tx_skb(sdata, local->hw_roc_skb);
00200                 local->hw_roc_skb = NULL;
00201         } else {
00202                 cfg80211_ready_on_channel(local->hw_roc_dev,
00203                                           local->hw_roc_cookie,
00204                                           local->hw_roc_channel,
00205                                           local->hw_roc_channel_type,
00206                                           local->hw_roc_duration,
00207                                           GFP_KERNEL);
00208         }
00209 
00210         ieee80211_recalc_idle(local);
00211 
00212         mutex_unlock(&local->mtx);
00213 }
00214 
00215 void ieee80211_ready_on_channel(struct ieee80211_hw *hw)
00216 {
00217         struct ieee80211_local *local = hw_to_local(hw);
00218 
00219         trace_api_ready_on_channel(local);
00220 
00221         ieee80211_queue_work(hw, &local->hw_roc_start);
00222 }
00223 EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel);
00224 
00225 static void ieee80211_hw_roc_done(struct work_struct *work)
00226 {
00227         struct ieee80211_local *local =
00228                 container_of(work, struct ieee80211_local, hw_roc_done);
00229 
00230         mutex_lock(&local->mtx);
00231 
00232         if (!local->hw_roc_channel) {
00233                 mutex_unlock(&local->mtx);
00234                 return;
00235         }
00236 
00237         /* was never transmitted */
00238         if (local->hw_roc_skb) {
00239                 u64 cookie;
00240 
00241                 cookie = local->hw_roc_cookie ^ 2;
00242 
00243                 cfg80211_mgmt_tx_status(local->hw_roc_dev, cookie,
00244                                         local->hw_roc_skb->data,
00245                                         local->hw_roc_skb->len, false,
00246                                         GFP_KERNEL);
00247 
00248                 kfree_skb(local->hw_roc_skb);
00249                 local->hw_roc_skb = NULL;
00250                 local->hw_roc_skb_for_status = NULL;
00251         }
00252 
00253         if (!local->hw_roc_for_tx)
00254                 cfg80211_remain_on_channel_expired(local->hw_roc_dev,
00255                                                    local->hw_roc_cookie,
00256                                                    local->hw_roc_channel,
00257                                                    local->hw_roc_channel_type,
00258                                                    GFP_KERNEL);
00259 
00260         local->hw_roc_channel = NULL;
00261         local->hw_roc_cookie = 0;
00262 
00263         ieee80211_recalc_idle(local);
00264 
00265         mutex_unlock(&local->mtx);
00266 }
00267 
00268 void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw)
00269 {
00270         struct ieee80211_local *local = hw_to_local(hw);
00271 
00272         trace_api_remain_on_channel_expired(local);
00273 
00274         ieee80211_queue_work(hw, &local->hw_roc_done);
00275 }
00276 EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired);
00277 
00278 void ieee80211_hw_roc_setup(struct ieee80211_local *local)
00279 {
00280         INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start);
00281         INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done);
00282 }


ros_rt_wmp
Author(s): Danilo Tardioli, dantard@unizar.es
autogenerated on Fri Jan 3 2014 12:07:55