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 */
ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data * sdata,bool tell_ap)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 */
ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data * sdata)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
ieee80211_offchannel_stop_vifs(struct ieee80211_local * local)106 void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local)
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 (sdata->vif.type == NL80211_IFTYPE_STATION &&
132 sdata->u.mgd.associated)
133 ieee80211_offchannel_ps_enable(sdata, true);
134 }
135 }
136 mutex_unlock(&local->iflist_mtx);
137 }
138
ieee80211_offchannel_return(struct ieee80211_local * local)139 void ieee80211_offchannel_return(struct ieee80211_local *local)
140 {
141 struct ieee80211_sub_if_data *sdata;
142
143 mutex_lock(&local->iflist_mtx);
144 list_for_each_entry(sdata, &local->interfaces, list) {
145 if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
146 clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
147
148 if (!ieee80211_sdata_running(sdata))
149 continue;
150
151 /* Tell AP we're back */
152 if (sdata->vif.type == NL80211_IFTYPE_STATION &&
153 sdata->u.mgd.associated)
154 ieee80211_offchannel_ps_disable(sdata);
155
156 if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
157 /*
158 * This may wake up queues even though the driver
159 * currently has them stopped. This is not very
160 * likely, since the driver won't have gotten any
161 * (or hardly any) new packets while we weren't
162 * on the right channel, and even if it happens
163 * it will at most lead to queueing up one more
164 * packet per queue in mac80211 rather than on
165 * the interface qdisc.
166 */
167 netif_tx_wake_all_queues(sdata->dev);
168 }
169
170 if (sdata->vif.type == NL80211_IFTYPE_AP ||
171 sdata->vif.type == NL80211_IFTYPE_ADHOC ||
172 sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
173 ieee80211_bss_info_change_notify(
174 sdata, BSS_CHANGED_BEACON_ENABLED);
175 }
176 mutex_unlock(&local->iflist_mtx);
177 }
178
ieee80211_hw_roc_start(struct work_struct * work)179 static void ieee80211_hw_roc_start(struct work_struct *work)
180 {
181 struct ieee80211_local *local =
182 container_of(work, struct ieee80211_local, hw_roc_start);
183 struct ieee80211_sub_if_data *sdata;
184
185 mutex_lock(&local->mtx);
186
187 if (!local->hw_roc_channel) {
188 mutex_unlock(&local->mtx);
189 return;
190 }
191
192 if (local->hw_roc_skb) {
193 sdata = IEEE80211_DEV_TO_SUB_IF(local->hw_roc_dev);
194 ieee80211_tx_skb(sdata, local->hw_roc_skb);
195 local->hw_roc_skb = NULL;
196 } else {
197 cfg80211_ready_on_channel(local->hw_roc_dev,
198 local->hw_roc_cookie,
199 local->hw_roc_channel,
200 local->hw_roc_channel_type,
201 local->hw_roc_duration,
202 GFP_KERNEL);
203 }
204
205 ieee80211_recalc_idle(local);
206
207 mutex_unlock(&local->mtx);
208 }
209
ieee80211_ready_on_channel(struct ieee80211_hw * hw)210 void ieee80211_ready_on_channel(struct ieee80211_hw *hw)
211 {
212 struct ieee80211_local *local = hw_to_local(hw);
213
214 trace_api_ready_on_channel(local);
215
216 ieee80211_queue_work(hw, &local->hw_roc_start);
217 }
218 EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel);
219
ieee80211_hw_roc_done(struct work_struct * work)220 static void ieee80211_hw_roc_done(struct work_struct *work)
221 {
222 struct ieee80211_local *local =
223 container_of(work, struct ieee80211_local, hw_roc_done);
224
225 mutex_lock(&local->mtx);
226
227 if (!local->hw_roc_channel) {
228 mutex_unlock(&local->mtx);
229 return;
230 }
231
232 /* was never transmitted */
233 if (local->hw_roc_skb) {
234 u64 cookie;
235
236 cookie = local->hw_roc_cookie ^ 2;
237
238 cfg80211_mgmt_tx_status(local->hw_roc_dev, cookie,
239 local->hw_roc_skb->data,
240 local->hw_roc_skb->len, false,
241 GFP_KERNEL);
242
243 kfree_skb(local->hw_roc_skb);
244 local->hw_roc_skb = NULL;
245 local->hw_roc_skb_for_status = NULL;
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
ieee80211_remain_on_channel_expired(struct ieee80211_hw * hw)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
ieee80211_hw_roc_setup(struct ieee80211_local * local)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