path: root/net/mac80211/offchannel.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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>
 * Copyright (C) 2019, 2022-2024 Intel Corporation
 */
#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;
	bool 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);

	wiphy_work_cancel(local->hw.wiphy, &local->dynamic_ps_enable_work);

	if (local->hw.conf.flags & IEEE80211_CONF_PS) {
		offchannel_ps_enabled = true;
		local->hw.conf.flags &= ~IEEE80211_CONF_PS;
		ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
	}

	if (!offchannel_ps_enabled ||
	    !ieee80211_hw_check(&local->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, true);
}

/* inform AP that we are awake again */
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, false);
	else if (local->hw.conf.dynamic_ps_timeout > 0) {
		/*
		 * 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 so that AP sends
		 * the buffered packets (if any).
		 */
		ieee80211_send_nullfunc(local, sdata, false);
		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;

	lockdep_assert_wiphy(local->hw.wiphy);

	if (WARN_ON(!local->emulate_chanctx))
		return;

	/*
	 * notify the AP about us leaving the channel and stop all
	 * STA interfaces.
	 */

	/*
	 * Stop queues and transmit all frames queued by the driver
	 * before sending nullfunc to enable powersave at the AP.
	 */
	ieee80211_stop_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP,
					IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL,
					false);
	ieee80211_flush_queues(local, NULL, false);

	list_for_each_entry(sdata, &local->interfaces, list) {
		if (!ieee80211_sdata_running(sdata))
			continue;

		if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE ||
		    sdata->vif.type == NL80211_IFTYPE_NAN)
			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_link_info_change_notify(
				sdata, &sdata->deflink,
				BSS_CHANGED_BEACON_ENABLED);
		}

		if (sdata->vif.type == NL80211_IFTYPE_STATION &&
		    sdata->u.mgd.associated)
			ieee80211_offchannel_ps_enable(sdata);
	}
}

void ieee80211_offchannel_return(struct ieee80211_local *local)
{
	struct ieee80211_sub_if_data *sdata;

	lockdep_assert_wiphy(local->hw.wiphy);

	if (WARN_ON(!local->emulate_chanctx))
		return;

	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 (test_and_clear_bit(SDATA_STATE_OFFCHANNEL_BEACON_STOPPED,
				       &sdata->state)) {
			sdata->vif.bss_conf.enable_beacon = true;
			ieee80211_link_info_change_notify(
				sdata, &sdata->deflink,
				BSS_CHANGED_BEACON_ENABLED);
		}
	}

	ieee80211_wake_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP,
					IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL,
					false);
}

static void ieee80211_roc_notify_destroy(struct ieee80211_roc_work *roc)
{
	/* was never transmitted */
	if (roc->frame) {