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/*
* Off-channel operation helpers
*
* Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
* Copyright 2004, Instant802 Networks, Inc.
* Copyright 2005, Devicescape Software, Inc.
* Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
* Copyright 2007, Michael Wu <flamingice@sourmilk.net>
* Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/export.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "driver-ops.h"
/*
* Tell our hardware to disable PS.
* Optionally inform AP that we will go to sleep so that it will buffer
* the frames while we are doing off-channel work. This is optional
* because we *may* be doing work on-operating channel, and want our
* hardware unconditionally awake, but still let the AP send us normal frames.
*/
static void ieee80211_offchannel_ps_enable(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_local *local = sdata->local;
struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
local->offchannel_ps_enabled = false;
/* FIXME: what to do when local->pspolling is true? */
del_timer_sync(&local->dynamic_ps_timer);
del_timer_sync(&ifmgd->bcn_mon_timer);
del_timer_sync(&ifmgd->conn_mon_timer);
cancel_work_sync(&local->dynamic_ps_enable_work);
if (local->hw.conf.flags & IEEE80211_CONF_PS) {
local->offchannel_ps_enabled = true;
local->hw.conf.flags &= ~IEEE80211_CONF_PS;
ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
}
if (!local->offchannel_ps_enabled ||
!(local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK))
/*
* If power save was enabled, no need to send a nullfunc
* frame because AP knows that we are sleeping. But if the
* hardware is creating the nullfunc frame for power save
* status (ie. IEEE80211_HW_PS_NULLFUNC_STACK is not
* enabled) and power save was enabled, the firmware just
* sent a null frame with power save disabled. So we need
* to send a new nullfunc frame to inform the AP that we
* are again sleeping.
*/
ieee80211_send_nullfunc(local, sdata, 1);
}
/* inform AP that we are awake again, unless power save is enabled */
static void ieee80211_offchannel_ps_disable(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_local *local = sdata->local;
if (!local->ps_sdata)
ieee80211_send_nullfunc(local, sdata, 0);
else if (local->offchannel_ps_enabled) {
/*
* In !IEEE80211_HW_PS_NULLFUNC_STACK case the hardware
* will send a nullfunc frame with the powersave bit set
* even though the AP already knows that we are sleeping.
* This could be avoided by sending a null frame with power
* save bit disabled before enabling the power save, but
* this doesn't gain anything.
*
* When IEEE80211_HW_PS_NULLFUNC_STACK is enabled, no need
* to send a nullfunc frame because AP already knows that
* we are sleeping, let's just enable power save mode in
* hardware.
*/
/* TODO: Only set hardware if CONF_PS changed?
* TODO: Should we set offchannel_ps_enabled to false?
*/
local->hw.conf.flags |= IEEE80211_CONF_PS;
ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
} else if (local->hw.conf.dynamic_ps_timeout > 0) {
/*
* If IEEE80211_CONF_PS was not set and the dynamic_ps_timer
* had been running before leaving the operating channel,
* restart the timer now and send a nullfunc frame to inform
* the AP that we are awake.
*/
ieee80211_send_nullfunc(local, sdata, 0);
mod_timer(&local->dynamic_ps_timer, jiffies +
msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
}
ieee80211_sta_reset_beacon_monitor(sdata);
ieee80211_sta_reset_conn_monitor(sdata);
}
void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local)
{
struct ieee80211_sub_if_data *sdata;
if (WARN_ON(local->use_chanctx))
return;
/*
* notify the AP about us leaving the channel and stop all
* STA interfaces.
*/
mutex_lock(&local->iflist_mtx);
list_for_each_entry(sdata, &local->interfaces, list) {
if (!ieee80211_sdata_running(sdata))
continue;
if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE)
continue;
if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
/* Check to see if we should disable beaconing. */
if (sdata->vif.bss_conf.enable_beacon) {
set_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED,
&sdata->state);
sdata->vif.bss_conf.enable_beacon = false;
ieee80211_bss_info_change_notify(
sdata, BSS_CHANGED_BEACON_ENABLED);
}
if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
netif_tx_stop_all_queues(sdata->dev);
if (sdata->vif.type == NL80211_IFTYPE_STATION &&
sdata->u.mgd.associated)
ieee80211_offchannel_ps_enable(sdata);
}
}
mutex_unlock(&local->iflist_mtx);
}
void ieee80211_offchannel_return(struct ieee80211_local *local)
{
struct ieee80211_sub_if_data *sdata;
if (WARN_ON(local->use_chanctx))
return;
mutex_lock(&local->iflist_mtx);
list_for_each_entry(sdata, &local->interfaces, list) {
if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE)
continue;
if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
clear_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
if (!ieee80211_sdata_running(sdata))
continue;
/* Tell AP we're back */
if (sdata->vif.type == NL80211_IFTYPE_STATION &&
sdata->u.mgd.associated)
ieee80211_offchannel_ps_disable(sdata);
if (sdata->vif.type != NL80211_IFTYPE_MONITOR) {
/*
* This may wake up queues even though the driver
* currently has them stopped. This is not very
* likely, since the driver won't have gotten any
* (or hardly any) new packets while we weren't
* on the right channel, and even if it happens
* it will at most lead to queueing up one more
* packet per queue in mac80211 rather than on
* the interface qdisc.
*/
netif_tx_wake_all_queues(sdata->dev);
}
if (test_and_clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED,
&sdata->state)) {
sdata->vif.bss_conf.enable_beacon = true;
ieee80211_bss_info_change_notify(
sdata, BSS_CHANGED_BEACON_ENABLED);
}
}
mutex_unlock(&local->iflist_mtx);
}
void ieee80211_handle_roc_started(struct ieee80211_roc_work *roc)
{
if (roc->notified)
return;
if (roc->mgmt_tx_cookie) {
if (!WARN_ON(!roc->frame)) {
ieee80211_tx_skb_tid_band(roc->sdata, roc->frame, 7,
roc->chan->band);
roc->frame = NULL;
}
} else {
cfg80211_ready_on_channel(&roc->sdata->wdev, roc->cookie,
roc->chan, roc->req_duration,
GFP_KERNEL);
}
roc->notified = true;
}
static void ieee80211_hw_roc_start(struct work_struct *work)
{
struct ieee80211_local *local =
container_of(work, struct ieee80211_local, hw_roc_start);
struct ieee80211_roc_work *roc, *dep, *tmp;
mutex_lock(&local->mtx);
if (list_empty(&local->roc_list))
goto out_unlock;
roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
list);
if (!roc->started)
goto out_unlock;
roc->hw_begun = true;
roc->hw_start_time = local->hw_roc_start_time;
ieee80211_handle_roc_started(roc);
list_for_each_entry_safe(dep, tmp, &roc->dependents, list) {
ieee80211_handle_roc_started(dep);
if (dep->duration > roc->duration) {
u32 dur = dep->duration;
dep->duration = dur - roc->duration;
roc->duration = dur;
list_move(&dep->list, &roc->list);
}
}
out_unlock:
mutex_unlock(&local->mtx);
}
void ieee80211_ready_on_channel(struct ieee80211_hw *hw)
{
struct ieee80211_local *local = hw_to_local(hw);
local->hw_roc_start_time = jiffies;
trace_api_ready_on_channel(local);
ieee80211_queue_work(hw, &local->hw_roc_start);
}
EXPORT_SYMBOL_GPL(ieee80211_ready_on_channel);
void ieee80211_start_next_roc(struct ieee80211_local *local)
{
struct ieee80211_roc_work *roc;
lockdep_assert_held(&local->mtx);
if (list_empty(&local->roc_list)) {
ieee80211_run_deferred_scan(local);
return;
}
roc = list_first_entry(&local->roc_list, struct ieee80211_roc_work,
list);
if (WARN_ON_ONCE(roc->started))
return;
if (local->ops->remain_on_channel) {
int ret, duration = roc->duration;
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