Fixed MTP to work with TWRP

net/mac80211/offchannel.c

@@ -0,0 +1,502 @@
+/*
+ * 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.
+	 */
+
+	/*
+	 * 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);
+
+	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_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 (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);
+
+	ieee80211_wake_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP,
+					IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL,
+					false);
+}
+
+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;
+
+		/* XXX: duplicated, see ieee80211_start_roc_work() */
+		if (!duration)
+			duration = 10;
+
+		ret = drv_remain_on_channel(local, roc->sdata, roc->chan,
+					    duration, roc->type);
+
+		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, bool free)
+{
+	struct ieee80211_roc_work *dep, *tmp;
+
+	if (WARN_ON(roc->to_be_freed))
+		return;
+
+	/* was never transmitted */
+	if (roc->frame) {
+		cfg80211_mgmt_tx_status(&roc->sdata->wdev,
+					(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->wdev,
+						   roc->cookie, roc->chan,
+						   GFP_KERNEL);
+
+	list_for_each_entry_safe(dep, tmp, &roc->dependents, list)
+		ieee80211_roc_notify_destroy(dep, true);
+
+	if (free)
+		kfree(roc);
+	else
+		roc->to_be_freed = true;
+}
+
+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;
+	bool started, on_channel;
+
+	mutex_lock(&local->mtx);
+
+	if (roc->to_be_freed)
+		goto out_unlock;
+
+	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;
+
+		WARN_ON(local->use_chanctx);
+
+		/* If actually operating on the desired channel (with at least
+		 * 20 MHz channel width) don't stop all the operations but still
+		 * treat it as though the ROC operation started properly, so
+		 * other ROC operations won't interfere with this one.
+		 */
+		roc->on_channel = roc->chan == local->_oper_chandef.chan &&
+				  local->_oper_chandef.width != NL80211_CHAN_WIDTH_5 &&
+				  local->_oper_chandef.width != NL80211_CHAN_WIDTH_10;
+
+		/* start this ROC */
+		ieee80211_recalc_idle(local);
+
+		if (!roc->on_channel) {
+			ieee80211_offchannel_stop_vifs(local);
+
+			local->tmp_channel = roc->chan;
+			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);
+		started = roc->started;
+		on_channel = roc->on_channel;
+		ieee80211_roc_notify_destroy(roc, !roc->abort);
+
+		if (started && !on_channel) {
+			ieee80211_flush_queues(local, NULL);
+
+			local->tmp_channel = NULL;
+			ieee80211_hw_config(local, 0);
+
+			ieee80211_offchannel_return(local);
+		}
+
+		ieee80211_recalc_idle(local);
+
+		if (started)
+			ieee80211_start_next_roc(local);
+		else if (list_empty(&local->roc_list))
+			ieee80211_run_deferred_scan(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, true);
+
+	/* 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_local *local,
+			 struct ieee80211_sub_if_data *sdata)
+{
+	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 (sdata && 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;
+	}
+	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, true);
+		} else {
+			ieee80211_queue_delayed_work(&local->hw, &roc->work, 0);
+
+			/* work will clean up etc */
+			flush_delayed_work(&roc->work);
+			WARN_ON(!roc->to_be_freed);
+			kfree(roc);
+		}
+	}
+
+	WARN_ON_ONCE(!list_empty(&tmp_list));
+}