1 files changed, 266 insertions, 38 deletions

diff --git a/net/rfkill/rfkill.c b/net/rfkill/rfkill.c
index 4e10a95de83..ce0e23148cd 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 +98,99 @@ 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
+ * calls toggle_radio taking into account a lot of "small"
+ * details.
+ * @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
+ *
+ * This wrappen protects and enforces the API for toggle_radio
+ * calls.  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 (state != 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 (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 +205,6 @@ 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 +215,66 @@ 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 +284,31 @@ 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 +317,7 @@ 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 +332,14 @@ 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 +380,8 @@ 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 +414,12 @@ 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 +436,8 @@ 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);
         }
@@ -269,12 +450,51 @@ 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)
@@ -283,7 +503,7 @@ static int rfkill_add_switch(struct rfkill *rfkill)
 
         mutex_lock(&rfkill_mutex);
 
-        error = rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type]);
+        error = rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type], 0);
         if (!error)
                 list_add_tail(&rfkill->node, &rfkill_list);
 
@@ -296,7 +516,7 @@ 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);
 }