dev: implement input event hooks

dev/input.c

@@ -38,7 +38,24 @@ kern_status_t input_device_report_event(struct input_device *dev, const struct i
 		flags = S_NOBLOCK;
 	}
 
-	size_t r = ringbuffer_write(event_queue, sizeof *ev, ev, flags);
+	struct input_event new_ev = *ev;
+	enum input_event_hook_flags hook_flags = 0;
+
+	queue_foreach (struct input_event_hook, hook, &dev->i_hooks, hook_head) {
+		if (hook->hook_callback) {
+			hook->hook_callback(input_device_base(dev), &new_ev, &hook_flags, hook->hook_arg);
+		}
+
+		if (hook_flags & INPUT_HOOK_SQUASH_EVENT) {
+			break;
+		}
+	}
+
+	if (hook_flags & INPUT_HOOK_SQUASH_EVENT) {
+		return KERN_OK;
+	}
+
+	size_t r = ringbuffer_write(event_queue, sizeof new_ev, &new_ev, flags);
 
 	return r == sizeof *ev ? KERN_OK : KERN_WOULD_BLOCK;
 }
@@ -61,6 +78,30 @@ kern_status_t input_device_read(struct device *dev, void *buf, size_t size, size
 	return KERN_OK;
 }
 
+kern_status_t input_device_add_hook(struct device *dev, struct input_event_hook *hook)
+{
+	struct input_device *inputdev = INPUT_DEVICE(dev);
+	if (!inputdev) {
+		return KERN_INVALID_ARGUMENT;
+	}
+
+	queue_push_back(&inputdev->i_hooks, &hook->hook_head);
+
+	return KERN_OK;
+}
+
+kern_status_t input_device_remove_hook(struct device *dev, struct input_event_hook *hook)
+{
+	struct input_device *inputdev = INPUT_DEVICE(dev);
+	if (!inputdev) {
+		return KERN_INVALID_ARGUMENT;
+	}
+
+	queue_delete(&inputdev->i_hooks, &hook->hook_head);
+
+	return KERN_OK;
+}
+
 static kern_status_t generate_name(struct input_device *dev, char out[DEV_NAME_MAX])
 {
 	snprintf(out, DEV_NAME_MAX, "input%u", dev->i_id);

include/socks/device.h

@@ -11,6 +11,7 @@
 
 struct device;
 struct input_event;
+struct input_event_hook;
 struct tty_device;
 
 #define DEV_NAME_MAX OBJECT_NAME_MAX
@@ -94,6 +95,7 @@ struct input_device {
 	struct input_device_ops *i_ops;
 	unsigned int i_id;
 	struct ringbuffer i_events;
+	struct queue i_hooks;
 };
 
 struct bus_device {
@@ -232,10 +234,42 @@ static inline struct device *framebuffer_device_base(struct framebuffer_device *
 	return (struct device *)((char *)dev - offsetof(struct device, fb));
 }
 
+static inline struct object *char_device_object(struct char_device *dev)
+{
+	return &char_device_base(dev)->dev_base;
+}
+
+static inline struct object *block_device_object(struct block_device *dev)
+{
+	return &block_device_base(dev)->dev_base;
+}
+
+static inline struct object *net_device_object(struct net_device *dev)
+{
+	return &net_device_base(dev)->dev_base;
+}
+
+static inline struct object *input_device_object(struct input_device *dev)
+{
+	return &input_device_base(dev)->dev_base;
+}
+
+static inline struct object *bus_device_object(struct bus_device *dev)
+{
+	return &bus_device_base(dev)->dev_base;
+}
+
+static inline struct object *framebuffer_device_object(struct framebuffer_device *dev)
+{
+	return &framebuffer_device_base(dev)->dev_base;
+}
+
 extern kern_status_t device_register(struct device *dev, struct driver *owner, struct device *parent);
 
 extern kern_status_t input_device_report_event(struct input_device *dev, const struct input_event *ev, bool noblock);
 extern kern_status_t input_device_read(struct device *dev, void *buf, size_t size, size_t *bytes_read, socks_flags_t flags);
+extern kern_status_t input_device_add_hook(struct device *dev, struct input_event_hook *hook);
+extern kern_status_t input_device_remove_hook(struct device *dev, struct input_event_hook *hook);
 
 extern struct driver *driver_create(struct kext *self, const char *name);
 extern kern_status_t driver_destroy(struct driver *driver);

include/socks/input.h

@@ -2,6 +2,14 @@
 #define SOCKS_INPUT_H_
 
 #include <stdint.h>
+#include <socks/queue.h>
+#include <socks/status.h>
+
+enum input_event_hook_flags {
+	INPUT_HOOK_SQUASH_EVENT = 0x01u,
+};
+
+struct device;
 
 enum input_event_type {
 	INPUT_TYPE_UNKNOWN = 0x00u,
@@ -167,4 +175,10 @@ struct input_event {
 	};
 };
 
+struct input_event_hook {
+	void(*hook_callback)(struct device *, struct input_event *, enum input_event_hook_flags *, void *);
+	void *hook_arg;
+	struct queue_entry hook_head;
+};
+
 #endif