/*
* 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-trace.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,
bool offchannel_ps_enable)
{
struct ieee80211_sub_if_data *sdata;
/*
* 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_MONITOR)
set_bit(SDATA_STATE_OFFCHANNEL, &sdata->state);
/* Check to see if we should disable beaconing. */
if (sdata->vif.type == NL80211_IFTYPE_AP ||
sdata->vif.type == NL80211_IFTYPE_ADHOC ||
sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
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 (offchannel_ps_enable &&
(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,
bool offchannel_ps_disable)
{
struct ieee80211_sub_if_data *sdata;
mutex_lock(&local->iflist_mtx);
list_for_each_entry(sdata, &local->interfaces, list) {
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 (offchannel_ps_disable &&
sdata->vif.type == NL80211_IFTYPE_STATION) {
if (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 (sdata->vif.type == NL80211_IFTYPE_AP ||
sdata->vif.type == NL80211_IFTYPE_ADHOC ||
sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
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(roc->sdata, roc->frame);
roc->frame = NULL;
}
} else {
cfg80211_ready_on_channel(roc->sdata->dev, (unsigned long)roc,
roc->chan, roc->chan_type,
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_del(&dep->list);
list_add(&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;
/* XXX: duplicated, see ieee80211_start_roc_work() */
if (!duration)
duration = 10;
ret = drv_remain_on_channel(local, roc->chan,
roc->chan_type,
duration);
roc->started = true;
if (ret) {
wiphy_warn(local->hw.wiphy,
"failed to start next HW ROC (%d)\n", ret);
/*
* queue the work struct again to avoid recursion
* when multiple failures occur
*/
ieee80211_remain_on_channel_expired(&local->hw);
}
} else {
/* delay it a bit */
ieee80211_queue_delayed_work(&local->hw, &roc->work,
round_jiffies_relative(HZ/2));
}
}
void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc)
{
struct ieee80211_roc_work *dep, *tmp;
/* was never transmitted */
if (roc->frame) {
cfg80211_mgmt_tx_status(roc->sdata->dev,
(unsigned long)roc->frame,
roc->frame->data, roc->frame->len,
false, GFP_KERNEL);
kfree_skb(roc->frame);
}
if (!roc->mgmt_tx_cookie)
cfg80211_remain_on_channel_expired(roc->sdata->dev,
(unsigned long)roc,
roc->chan, roc->chan_type,
GFP_KERNEL);
list_for_each_entry_safe(dep, tmp, &roc->dependents, list)
ieee80211_roc_notify_destroy(dep);
kfree(roc);
}
void ieee80211_sw_roc_work(struct work_struct *work)
{
struct ieee80211_roc_work *roc =
container_of(work, struct ieee80211_roc_work, work.work);
struct ieee80211_sub_if_data *sdata = roc->sdata;
struct ieee80211_local *local = sdata->local;
mutex_lock(&local->mtx);
if (roc->abort)
goto finish;
if (WARN_ON(list_empty(&local->roc_list)))
goto out_unlock;
if (WARN_ON(roc != list_first_entry(&local->roc_list,
struct ieee80211_roc_work,
list)))
goto out_unlock;
if (!roc->started) {
struct ieee80211_roc_work *dep;
/* start this ROC */
/* switch channel etc */
ieee80211_recalc_idle(local);
local->tmp_channel = roc->chan;
local->tmp_channel_type = roc->chan_type;
ieee80211_hw_config(local, 0);
/* tell userspace or send frame */
ieee80211_handle_roc_started(roc);
list_for_each_entry(dep, &roc->dependents, list)
ieee80211_handle_roc_started(dep);
/* if it was pure TX, just finish right away */
if (!roc->duration)
goto finish;
roc->started = true;
ieee80211_queue_delayed_work(&local->hw, &roc->work,
msecs_to_jiffies(roc->duration));
} else {
/* finish this ROC */
finish:
list_del(&roc->list);
ieee80211_roc_notify_destroy(roc);
if (roc->started) {
drv_flush(local, false);
local->tmp_channel = NULL;
ieee80211_hw_config(local, 0);
ieee80211_offchannel_return(local, true);
}
ieee80211_recalc_idle(local);
if (roc->started)
ieee80211_start_next_roc(local);
}
out_unlock:
mutex_unlock(&local->mtx);
}
static void ieee80211_hw_roc_done(struct work_struct *work)
{
struct ieee80211_local *local =
container_of(work, struct ieee80211_local, hw_roc_done);
struct ieee80211_roc_work *roc;
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;
list_del(&roc->list);
ieee80211_roc_notify_destroy(roc);
/* if there's another roc, start it now */
ieee80211_start_next_roc(local);
out_unlock:
mutex_unlock(&local->mtx);
}
void ieee80211_remain_on_channel_expired(struct ieee80211_hw *hw)
{
struct ieee80211_local *local = hw_to_local(hw);
trace_api_remain_on_channel_expired(local);
ieee80211_queue_work(hw, &local->hw_roc_done);
}
EXPORT_SYMBOL_GPL(ieee80211_remain_on_channel_expired);
void ieee80211_roc_setup(struct ieee80211_local *local)
{
INIT_WORK(&local->hw_roc_start, ieee80211_hw_roc_start);
INIT_WORK(&local->hw_roc_done, ieee80211_hw_roc_done);
INIT_LIST_HEAD(&local->roc_list);
}
void ieee80211_roc_purge(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_local *local = sdata->local;
struct ieee80211_roc_work *roc, *tmp;
LIST_HEAD(tmp_list);
mutex_lock(&local->mtx);
list_for_each_entry_safe(roc, tmp, &local->roc_list, list) {
if (roc->sdata != sdata)
continue;
if (roc->started && local->ops->remain_on_channel) {
/* can race, so ignore return value */
drv_cancel_remain_on_channel(local);
}
list_move_tail(&roc->list, &tmp_list);
roc->abort = true;
}
ieee80211_start_next_roc(local);
mutex_unlock(&local->mtx);
list_for_each_entry_safe(roc, tmp, &tmp_list, list) {
if (local->ops->remain_on_channel) {
list_del(&roc->list);
ieee80211_roc_notify_destroy(roc);
} else {
ieee80211_queue_delayed_work(&local->hw, &roc->work, 0);
/* work will clean up etc */
flush_delayed_work(&roc->work);
}
}
WARN_ON_ONCE(!list_empty(&tmp_list));
}
