1 files changed, 271 insertions, 43 deletions

diff --git a/net/rfkill/rfkill.c b/net/rfkill/rfkill.c
index 4e10a95..7a560b7 100644
--- a/net/rfkill/rfkill.c
+++ b/net/rfkill/rfkill.c
@@ -39,8 +39,56 @@ MODULE_LICENSE("GPL");
 static LIST_HEAD(rfkill_list);	/* list of registered rf switches */
 static DEFINE_MUTEX(rfkill_mutex);
 
+static unsigned int rfkill_default_state = RFKILL_STATE_UNBLOCKED;
+module_param_named(default_state, rfkill_default_state, uint, 0444);
+MODULE_PARM_DESC(default_state,
+		 "Default initial state for all radio types, 0 = radio off");
+
 static enum rfkill_state rfkill_states[RFKILL_TYPE_MAX];
 
+static BLOCKING_NOTIFIER_HEAD(rfkill_notifier_list);
+
+
+/**
+ * register_rfkill_notifier - Add notifier to rfkill notifier chain
+ * @nb: pointer to the new entry to add to the chain
+ *
+ * See blocking_notifier_chain_register() for return value and further
+ * observations.
+ *
+ * Adds a notifier to the rfkill notifier chain.  The chain will be
+ * called with a pointer to the relevant rfkill structure as a parameter,
+ * refer to include/linux/rfkill.h for the possible events.
+ *
+ * Notifiers added to this chain are to always return NOTIFY_DONE.  This
+ * chain is a blocking notifier chain: notifiers can sleep.
+ *
+ * Calls to this chain may have been done through a workqueue.  One must
+ * assume unordered asynchronous behaviour, there is no way to know if
+ * actions related to the event that generated the notification have been
+ * carried out already.
+ */
+int register_rfkill_notifier(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_register(&rfkill_notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(register_rfkill_notifier);
+
+/**
+ * unregister_rfkill_notifier - remove notifier from rfkill notifier chain
+ * @nb: pointer to the entry to remove from the chain
+ *
+ * See blocking_notifier_chain_unregister() for return value and further
+ * observations.
+ *
+ * Removes a notifier from the rfkill notifier chain.
+ */
+int unregister_rfkill_notifier(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_unregister(&rfkill_notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(unregister_rfkill_notifier);
+
 
 static void rfkill_led_trigger(struct rfkill *rfkill,
 			       enum rfkill_state state)
@@ -50,24 +98,101 @@ static void rfkill_led_trigger(struct rfkill *rfkill,
 
 	if (!led->name)
 		return;
-	if (state == RFKILL_STATE_OFF)
+	if (state != RFKILL_STATE_UNBLOCKED)
 		led_trigger_event(led, LED_OFF);
 	else
 		led_trigger_event(led, LED_FULL);
 #endif /* CONFIG_RFKILL_LEDS */
 }
 
+static void notify_rfkill_state_change(struct rfkill *rfkill)
+{
+	blocking_notifier_call_chain(&rfkill_notifier_list,
+			RFKILL_STATE_CHANGED,
+			rfkill);
+}
+
+static void update_rfkill_state(struct rfkill *rfkill)
+{
+	enum rfkill_state newstate, oldstate;
+
+	if (rfkill->get_state) {
+		mutex_lock(&rfkill->mutex);
+		if (!rfkill->get_state(rfkill->data, &newstate)) {
+			oldstate = rfkill->state;
+			rfkill->state = newstate;
+			if (oldstate != newstate)
+				notify_rfkill_state_change(rfkill);
+		}
+		mutex_unlock(&rfkill->mutex);
+	}
+}
+
+/**
+ * rfkill_toggle_radio - wrapper for toggle_radio hook
+ *
+ * @rfkill: the rfkill struct to use
+ * @force: calls toggle_radio even if cache says it is not needed,
+ *	and also makes sure notifications of the state will be
+ *	sent even if it didn't change
+ * @state: the new state to call toggle_radio() with
+ *
+ * Calls rfkill->toggle_radio, enforcing the API for toggle_radio
+ * calls and handling all the red tape such as issuing notifications
+ * if the call is successful.
+ *
+ * Note that @force cannot override a (possibly cached) state of
+ * RFKILL_STATE_HARD_BLOCKED.  Any device making use of
+ * RFKILL_STATE_HARD_BLOCKED implements either get_state() or
+ * rfkill_force_state(), so the cache either is bypassed or valid.
+ *
+ * Note that we do call toggle_radio for RFKILL_STATE_SOFT_BLOCKED
+ * even if the radio is in RFKILL_STATE_HARD_BLOCKED state, so as to
+ * give the driver a hint that it should double-BLOCK the transmitter.
+ *
+ * Caller must have aquired rfkill_mutex.
+ */
 static int rfkill_toggle_radio(struct rfkill *rfkill,
-				enum rfkill_state state)
+				enum rfkill_state state,
+				int force)
 {
 	int retval = 0;
+	enum rfkill_state oldstate, newstate;
+
+	oldstate = rfkill->state;
+
+	if (rfkill->get_state && !force &&
+	    !rfkill->get_state(rfkill->data, &newstate))
+		rfkill->state = newstate;
+
+	switch (state) {
+	case RFKILL_STATE_HARD_BLOCKED:
+		/* typically happens when refreshing hardware state,
+		 * such as on resume */
+		state = RFKILL_STATE_SOFT_BLOCKED;
+		break;
+	case RFKILL_STATE_UNBLOCKED:
+		/* force can't override this, only rfkill_force_state() can */
+		if (rfkill->state == RFKILL_STATE_HARD_BLOCKED)
+			return -EPERM;
+		break;
+	case RFKILL_STATE_SOFT_BLOCKED:
+		/* nothing to do, we want to give drivers the hint to double
+		 * BLOCK even a transmitter that is already in state
+		 * RFKILL_STATE_HARD_BLOCKED */
+		break;
+	}
 
-	if (state != rfkill->state) {
+	if (force || state != rfkill->state) {
 		retval = rfkill->toggle_radio(rfkill->data, state);
-		if (!retval) {
+		/* never allow a HARD->SOFT downgrade! */
+		if (!retval && rfkill->state != RFKILL_STATE_HARD_BLOCKED)
 			rfkill->state = state;
-			rfkill_led_trigger(rfkill, state);
-		}
+	}
+
+	if (force || rfkill->state != oldstate) {
+		rfkill_led_trigger(rfkill, rfkill->state);
+		notify_rfkill_state_change(rfkill);
 	}
 
 	return retval;
@@ -82,7 +207,6 @@ static int rfkill_toggle_radio(struct rfkill *rfkill,
  * a specific switch is claimed by userspace in which case it is
  * left alone.
  */
-
 void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
 {
 	struct rfkill *rfkill;
@@ -93,13 +217,66 @@ void rfkill_switch_all(enum rfkill_type type, enum rfkill_state state)
 
 	list_for_each_entry(rfkill, &rfkill_list, node) {
 		if ((!rfkill->user_claim) && (rfkill->type == type))
-			rfkill_toggle_radio(rfkill, state);
+			rfkill_toggle_radio(rfkill, state, 0);
 	}
 
 	mutex_unlock(&rfkill_mutex);
 }
 EXPORT_SYMBOL(rfkill_switch_all);
 
+/**
+ * rfkill_epo - emergency power off all transmitters
+ *
+ * This kicks all rfkill devices to RFKILL_STATE_SOFT_BLOCKED, ignoring
+ * everything in its path but rfkill_mutex.
+ */
+void rfkill_epo(void)
+{
+	struct rfkill *rfkill;
+
+	mutex_lock(&rfkill_mutex);
+	list_for_each_entry(rfkill, &rfkill_list, node) {
+		rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
+	}
+	mutex_unlock(&rfkill_mutex);
+}
+EXPORT_SYMBOL_GPL(rfkill_epo);
+
+/**
+ * rfkill_force_state - Force the internal rfkill radio state
+ * @rfkill: pointer to the rfkill class to modify.
+ * @state: the current radio state the class should be forced to.
+ *
+ * This function updates the internal state of the radio cached
+ * by the rfkill class.  It should be used when the driver gets
+ * a notification by the firmware/hardware of the current *real*
+ * state of the radio rfkill switch.
+ *
+ * It may not be called from an atomic context.
+ */
+int rfkill_force_state(struct rfkill *rfkill, enum rfkill_state state)
+{
+	enum rfkill_state oldstate;
+
+	if (state != RFKILL_STATE_SOFT_BLOCKED &&
+	    state != RFKILL_STATE_UNBLOCKED &&
+	    state != RFKILL_STATE_HARD_BLOCKED)
+		return -EINVAL;
+
+	mutex_lock(&rfkill->mutex);
+
+	oldstate = rfkill->state;
+	rfkill->state = state;
+
+	if (state != oldstate)
+		notify_rfkill_state_change(rfkill);
+
+	mutex_unlock(&rfkill->mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL(rfkill_force_state);
+
 static ssize_t rfkill_name_show(struct device *dev,
 				struct device_attribute *attr,
 				char *buf)
@@ -109,31 +286,31 @@ static ssize_t rfkill_name_show(struct device *dev,
 	return sprintf(buf, "%s\n", rfkill->name);
 }
 
-static ssize_t rfkill_type_show(struct device *dev,
-				struct device_attribute *attr,
-				char *buf)
+static const char *rfkill_get_type_str(enum rfkill_type type)
 {
-	struct rfkill *rfkill = to_rfkill(dev);
-	const char *type;
-
-	switch (rfkill->type) {
+	switch (type) {
 	case RFKILL_TYPE_WLAN:
-		type = "wlan";
-		break;
+		return "wlan";
 	case RFKILL_TYPE_BLUETOOTH:
-		type = "bluetooth";
-		break;
+		return "bluetooth";
 	case RFKILL_TYPE_UWB:
-		type = "ultrawideband";
-		break;
+		return "ultrawideband";
 	case RFKILL_TYPE_WIMAX:
-		type = "wimax";
-		break;
+		return "wimax";
+	case RFKILL_TYPE_WWAN:
+		return "wwan";
 	default:
 		BUG();
 	}
+}
+
+static ssize_t rfkill_type_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	struct rfkill *rfkill = to_rfkill(dev);
 
-	return sprintf(buf, "%s\n", type);
+	return sprintf(buf, "%s\n", rfkill_get_type_str(rfkill->type));
 }
 
 static ssize_t rfkill_state_show(struct device *dev,
@@ -142,6 +319,7 @@ static ssize_t rfkill_state_show(struct device *dev,
 {
 	struct rfkill *rfkill = to_rfkill(dev);
 
+	update_rfkill_state(rfkill);
 	return sprintf(buf, "%d\n", rfkill->state);
 }
 
@@ -156,10 +334,14 @@ static ssize_t rfkill_state_store(struct device *dev,
 	if (!capable(CAP_NET_ADMIN))
 		return -EPERM;
 
+	/* RFKILL_STATE_HARD_BLOCKED is illegal here... */
+	if (state != RFKILL_STATE_UNBLOCKED &&
+	    state != RFKILL_STATE_SOFT_BLOCKED)
+		return -EINVAL;
+
 	if (mutex_lock_interruptible(&rfkill->mutex))
 		return -ERESTARTSYS;
-	error = rfkill_toggle_radio(rfkill,
-			state ? RFKILL_STATE_ON : RFKILL_STATE_OFF);
+	error = rfkill_toggle_radio(rfkill, state, 0);
 	mutex_unlock(&rfkill->mutex);
 
 	return error ? error : count;
@@ -200,7 +382,8 @@ static ssize_t rfkill_claim_store(struct device *dev,
 	if (rfkill->user_claim != claim) {
 		if (!claim)
 			rfkill_toggle_radio(rfkill,
-					    rfkill_states[rfkill->type]);
+					    rfkill_states[rfkill->type],
+					    0);
 		rfkill->user_claim = claim;
 	}
 
@@ -233,12 +416,12 @@ static int rfkill_suspend(struct device *dev, pm_message_t state)
 
 	if (dev->power.power_state.event != state.event) {
 		if (state.event & PM_EVENT_SLEEP) {
-			mutex_lock(&rfkill->mutex);
-
-			if (rfkill->state == RFKILL_STATE_ON)
-				rfkill->toggle_radio(rfkill->data,
-						     RFKILL_STATE_OFF);
+			/* Stop transmitter, keep state, no notifies */
+			update_rfkill_state(rfkill);
 
+			mutex_lock(&rfkill->mutex);
+			rfkill->toggle_radio(rfkill->data,
+						RFKILL_STATE_SOFT_BLOCKED);
 			mutex_unlock(&rfkill->mutex);
 		}
 
@@ -255,8 +438,8 @@ static int rfkill_resume(struct device *dev)
 	if (dev->power.power_state.event != PM_EVENT_ON) {
 		mutex_lock(&rfkill->mutex);
 
-		if (rfkill->state == RFKILL_STATE_ON)
-			rfkill->toggle_radio(rfkill->data, RFKILL_STATE_ON);
+		/* restore radio state AND notify everybody */
+		rfkill_toggle_radio(rfkill, rfkill->state, 1);
 
 		mutex_unlock(&rfkill->mutex);
 	}
@@ -269,34 +452,71 @@ static int rfkill_resume(struct device *dev)
 #define rfkill_resume NULL
 #endif
 
+static int rfkill_blocking_uevent_notifier(struct notifier_block *nb,
+					unsigned long eventid,
+					void *data)
+{
+	struct rfkill *rfkill = (struct rfkill *)data;
+
+	switch (eventid) {
+	case RFKILL_STATE_CHANGED:
+		kobject_uevent(&rfkill->dev.kobj, KOBJ_CHANGE);
+		break;
+	default:
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block rfkill_blocking_uevent_nb = {
+	.notifier_call	= rfkill_blocking_uevent_notifier,
+	.priority	= 0,
+};
+
+static int rfkill_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	struct rfkill *rfkill = to_rfkill(dev);
+	int error;
+
+	error = add_uevent_var(env, "RFKILL_NAME=%s", rfkill->name);
+	if (error)
+		return error;
+	error = add_uevent_var(env, "RFKILL_TYPE=%s",
+				rfkill_get_type_str(rfkill->type));
+	if (error)
+		return error;
+	error = add_uevent_var(env, "RFKILL_STATE=%d", rfkill->state);
+	return error;
+}
+
 static struct class rfkill_class = {
 	.name		= "rfkill",
 	.dev_release	= rfkill_release,
 	.dev_attrs	= rfkill_dev_attrs,
 	.suspend	= rfkill_suspend,
 	.resume		= rfkill_resume,
+	.dev_uevent	= rfkill_dev_uevent,
 };
 
 static int rfkill_add_switch(struct rfkill *rfkill)
 {
-	int error;
-
 	mutex_lock(&rfkill_mutex);
 
-	error = rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type]);
-	if (!error)
-		list_add_tail(&rfkill->node, &rfkill_list);
+	rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type], 0);
+
+	list_add_tail(&rfkill->node, &rfkill_list);
 
 	mutex_unlock(&rfkill_mutex);
 
-	return error;
+	return 0;
 }
 
 static void rfkill_remove_switch(struct rfkill *rfkill)
 {
 	mutex_lock(&rfkill_mutex);
 	list_del_init(&rfkill->node);
-	rfkill_toggle_radio(rfkill, RFKILL_STATE_OFF);
+	rfkill_toggle_radio(rfkill, RFKILL_STATE_SOFT_BLOCKED, 1);
 	mutex_unlock(&rfkill_mutex);
 }
 
@@ -412,7 +632,7 @@ int rfkill_register(struct rfkill *rfkill)
 EXPORT_SYMBOL(rfkill_register);
 
 /**
- * rfkill_unregister - Uegister a rfkill structure.
+ * rfkill_unregister - Unregister a rfkill structure.
  * @rfkill: rfkill structure to be unregistered
  *
  * This function should be called by the network driver during device
@@ -436,8 +656,13 @@ static int __init rfkill_init(void)
 	int error;
 	int i;
 
+	/* RFKILL_STATE_HARD_BLOCKED is illegal here... */
+	if (rfkill_default_state != RFKILL_STATE_SOFT_BLOCKED &&
+	    rfkill_default_state != RFKILL_STATE_UNBLOCKED)
+		return -EINVAL;
+
 	for (i = 0; i < ARRAY_SIZE(rfkill_states); i++)
-		rfkill_states[i] = RFKILL_STATE_ON;
+		rfkill_states[i] = rfkill_default_state;
 
 	error = class_register(&rfkill_class);
 	if (error) {
@@ -445,11 +670,14 @@ static int __init rfkill_init(void)
 		return error;
 	}
 
+	register_rfkill_notifier(&rfkill_blocking_uevent_nb);
+
 	return 0;
 }
 
 static void __exit rfkill_exit(void)
 {
+	unregister_rfkill_notifier(&rfkill_blocking_uevent_nb);
 	class_unregister(&rfkill_class);
 }