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 */
ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data * sdata,bool tell_ap)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 */
ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data * sdata)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
ieee80211_offchannel_stop_vifs(struct ieee80211_local * local,bool offchannel_ps_enable)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
ieee80211_offchannel_enable_all_ps(struct ieee80211_local * local,bool tell_ap)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
ieee80211_offchannel_return(struct ieee80211_local * local,bool enable_beaconing,bool offchannel_ps_disable)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
ieee80211_hw_roc_start(struct work_struct * work)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
ieee80211_ready_on_channel(struct ieee80211_hw * hw)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
ieee80211_hw_roc_done(struct work_struct * work)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
ieee80211_remain_on_channel_expired(struct ieee80211_hw * hw)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
ieee80211_hw_roc_setup(struct ieee80211_local * local)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