gohook/hook/darwin/hook_c.h

/* Copyright (C) 2006-2017 Alexander Barker.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
*/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#ifndef USE_WEAK_IMPORT
	#include <dlfcn.h>
#endif
#include <mach/mach_time.h>
#ifdef USE_OBJC
	#include <objc/objc.h>
	#include <objc/objc-runtime.h>
#endif

#include <pthread.h>
#include <stdbool.h>
#include <sys/time.h>
#include "../iohook.h"
// #include "../logger_c.h"
#include "input.h"

typedef struct _hook_info {
	CFMachPortRef port;
	CFRunLoopSourceRef source;
	CFRunLoopObserverRef observer;
} hook_info;

#ifdef USE_OBJC
static id auto_release_pool;
#endif

// Event runloop reference.
CFRunLoopRef event_loop;

// Flag to restart the event tap incase of timeout.
static Boolean restart_tap = false;

// Modifiers for tracking key masks.
static uint16_t current_modifiers = 0x0000;

// Required to transport messages between the main runloop and our thread for
// Unicode lookups.
#define KEY_BUFFER_SIZE 4
typedef struct {
	CGEventRef event;
	UniChar buffer[KEY_BUFFER_SIZE];
	UniCharCount length;
} TISMessage;
TISMessage *tis_message;

#ifdef USE_WEAK_IMPORT
// Required to dynamically check for AXIsProcessTrustedWithOptions availability.
extern void dispatch_get_main_queue() __attribute__((weak_import));
extern void dispatch_sync_f(dispatch_queue_t queue, void *context, void (*function)(void *)) __attribute__((weak_import));
#else
#if __MAC_OS_X_VERSION_MAX_ALLOWED <= 1050
typedef void* dispatch_queue_t;
#endif
static dispatch_queue_t (*dispatch_get_main_queue_f)();
static void (*dispatch_sync_f_f)(dispatch_queue_t, void *, void (*function)(void *));
#endif

#if ! defined(USE_CARBON_LEGACY) && defined(USE_COREFOUNDATION)
static CFRunLoopSourceRef src_msg_port;
static CFRunLoopObserverRef observer;

static pthread_cond_t msg_port_cond = PTHREAD_COND_INITIALIZER;
static pthread_mutex_t msg_port_mutex = PTHREAD_MUTEX_INITIALIZER;
#endif

// Click count globals.
static unsigned short click_count = 0;
static CGEventTimestamp click_time = 0;
static unsigned short int click_button = MOUSE_NOBUTTON;
static bool mouse_dragged = false;

// Structure for the current Unix epoch in milliseconds.
static struct timeval system_time;

// Virtual event pointer.
static iohook_event event;

// Event dispatch callback.
static dispatcher_t dispatcher = NULL;

IOHOOK_API void hook_set_dispatch_proc(dispatcher_t dispatch_proc) {
	logger(LOG_LEVEL_DEBUG,	"%s [%u]: Setting new dispatch callback to %#p.\n",
			__FUNCTION__, __LINE__, dispatch_proc);

	dispatcher = dispatch_proc;
}

// Send out an event if a dispatcher was set.
static inline void dispatch_event(iohook_event *const event) {
	if (dispatcher != NULL) {
		logger(LOG_LEVEL_DEBUG,	"%s [%u]: Dispatching event type %u.\n",
				__FUNCTION__, __LINE__, event->type);

		dispatcher(event);
	} else {
		logger(LOG_LEVEL_WARN,	"%s [%u]: No dispatch callback set!\n",
				__FUNCTION__, __LINE__);
	}
}


// Set the native modifier mask for future events.
static inline void set_modifier_mask(uint16_t mask) {
	current_modifiers |= mask;
}

// Unset the native modifier mask for future events.
static inline void unset_modifier_mask(uint16_t mask) {
	current_modifiers ^= mask;
}

// Get the current native modifier mask state.
static inline uint16_t get_modifiers() {
	return current_modifiers;
}

// Initialize the modifier mask to the current modifiers.
static void initialize_modifiers() {
	current_modifiers = 0x0000;

	if (CGEventSourceKeyState(kCGEventSourceStateCombinedSessionState, kVK_Shift)) {
		set_modifier_mask(MASK_SHIFT_L);
	}
	if (CGEventSourceKeyState(kCGEventSourceStateCombinedSessionState, kVK_RightShift)) {
		set_modifier_mask(MASK_SHIFT_R);
	}
	if (CGEventSourceKeyState(kCGEventSourceStateCombinedSessionState, kVK_Control)) {
		set_modifier_mask(MASK_CTRL_L);
	}
	if (CGEventSourceKeyState(kCGEventSourceStateCombinedSessionState, kVK_RightControl)) {
		set_modifier_mask(MASK_CTRL_R);
	}
	if (CGEventSourceKeyState(kCGEventSourceStateCombinedSessionState, kVK_Option)) {
		set_modifier_mask(MASK_ALT_L);
	}
	if (CGEventSourceKeyState(kCGEventSourceStateCombinedSessionState, kVK_RightOption)) {
		set_modifier_mask(MASK_ALT_R);
	}
	if (CGEventSourceKeyState(kCGEventSourceStateCombinedSessionState, kVK_Command)) {
		set_modifier_mask(MASK_META_L);
	}
	if (CGEventSourceKeyState(kCGEventSourceStateCombinedSessionState, kVK_RightCommand)) {
		set_modifier_mask(MASK_META_R);
	}

	if (CGEventSourceButtonState(kCGEventSourceStateCombinedSessionState, kVK_LBUTTON)) {
		set_modifier_mask(MASK_BUTTON1);
 	}
 	if (CGEventSourceButtonState(kCGEventSourceStateCombinedSessionState, kVK_RBUTTON)) {
		set_modifier_mask(MASK_BUTTON2);
	}
	if (CGEventSourceButtonState(kCGEventSourceStateCombinedSessionState, kVK_MBUTTON)) {
		set_modifier_mask(MASK_BUTTON3);
	}
	if (CGEventSourceButtonState(kCGEventSourceStateCombinedSessionState, kVK_XBUTTON1)) {
		set_modifier_mask(MASK_BUTTON4);
	}
	if (CGEventSourceButtonState(kCGEventSourceStateCombinedSessionState, kVK_XBUTTON2)) {
		set_modifier_mask(MASK_BUTTON5);
	}

	if (CGEventSourceFlagsState(kCGEventSourceStateCombinedSessionState) & kCGEventFlagMaskAlphaShift) {
		set_modifier_mask(MASK_CAPS_LOCK);
	}
	// Best I can tell, OS X does not support Num or Scroll lock.
	unset_modifier_mask(MASK_NUM_LOCK);
	unset_modifier_mask(MASK_SCROLL_LOCK);
}


// Wrap keycode_to_unicode with some null checks.
static void keycode_to_lookup(void *info) {
	TISMessage *data = (TISMessage *) info;

	if (data != NULL && data->event != NULL) {
		// Preform Unicode lookup.
		data->length = keycode_to_unicode(data->event, data->buffer, KEY_BUFFER_SIZE);
	}
}

#if ! defined(USE_CARBON_LEGACY) && defined(USE_COREFOUNDATION)
void message_port_status_proc(CFRunLoopObserverRef observer, CFRunLoopActivity activity, void *info) {
	switch (activity) {
		case kCFRunLoopExit:
			// Acquire a lock on the msg_port and signal that anyone waiting
			// should continue.
			pthread_mutex_lock(&msg_port_mutex);
			pthread_cond_broadcast(&msg_port_cond);
			pthread_mutex_unlock(&msg_port_mutex);
			break;

		default:
			logger(LOG_LEVEL_WARN,	"%s [%u]: Unhandled RunLoop activity! (%#X)\n",
					__FUNCTION__, __LINE__, (unsigned int) activity);
			break;
	}
}

// Runloop to execute KeyCodeToString on the "Main" runloop due to an
// undocumented thread safety requirement.
static void message_port_proc(void *info) {
	// Lock the msg_port mutex as we enter the main runloop.
	pthread_mutex_lock(&msg_port_mutex);

	keycode_to_lookup(info);

	// Unlock the msg_port mutex to signal to the hook_thread that we have
	// finished on the main runloop.
	pthread_cond_broadcast(&msg_port_cond);
	pthread_mutex_unlock(&msg_port_mutex);
}

static int start_message_port_runloop() {
	int status = IOHOOK_FAILURE;

	if (tis_message != NULL) {
		// Create a runloop observer for the main runloop.
		observer = CFRunLoopObserverCreate(
				kCFAllocatorDefault,
				kCFRunLoopExit, //kCFRunLoopEntry | kCFRunLoopExit, //kCFRunLoopAllActivities,
				true,
				0,
				message_port_status_proc,
				NULL
			);

		if (observer != NULL) {
			pthread_mutex_lock(&msg_port_mutex);

			CFRunLoopSourceContext context = {
				.version			= 0,
				.info				= tis_message,
				.retain				= NULL,
				.release			= NULL,
				.copyDescription	= NULL,
				.equal				= NULL,
				.hash				= NULL,
				.schedule			= NULL,
				.cancel				= NULL,
				.perform			= message_port_proc
			};

			CFRunLoopRef main_loop = CFRunLoopGetMain();

			src_msg_port = CFRunLoopSourceCreate(kCFAllocatorDefault, 0, &context);
			if (src_msg_port != NULL) {
				CFRunLoopAddSource(main_loop, src_msg_port, kCFRunLoopDefaultMode);
				CFRunLoopAddObserver(main_loop, observer, kCFRunLoopDefaultMode);

				logger(LOG_LEVEL_DEBUG, "%s [%u]: Successful.\n",
						__FUNCTION__, __LINE__);

				status = IOHOOK_SUCCESS;
			} else {
				logger(LOG_LEVEL_ERROR,	"%s [%u]: CFRunLoopSourceCreate failure!\n",
						__FUNCTION__, __LINE__);

				status = IOHOOK_ERROR_CREATE_RUN_LOOP_SOURCE;
			}

			pthread_mutex_unlock(&msg_port_mutex);
		} else {
			logger(LOG_LEVEL_ERROR,	"%s [%u]: CFRunLoopObserverCreate failure!\n",
					__FUNCTION__, __LINE__);

			status = IOHOOK_ERROR_CREATE_OBSERVER;
		}
	} else {
		logger(LOG_LEVEL_ERROR, "%s [%u]: No available TIS Message pointer.\n",
				__FUNCTION__, __LINE__);
	}

	return status;
}

static void stop_message_port_runloop() {
	CFRunLoopRef main_loop = CFRunLoopGetMain();

	if (CFRunLoopContainsObserver(main_loop, observer, kCFRunLoopDefaultMode)) {
		CFRunLoopRemoveObserver(main_loop, observer, kCFRunLoopDefaultMode);
		CFRunLoopObserverInvalidate(observer);
	}

	if (CFRunLoopContainsSource(main_loop, src_msg_port, kCFRunLoopDefaultMode)) {
		CFRunLoopRemoveSource(main_loop, src_msg_port, kCFRunLoopDefaultMode);
		CFRelease(src_msg_port);
	}

	observer = NULL;
	src_msg_port = NULL;

	logger(LOG_LEVEL_DEBUG,	"%s [%u]: Successful.\n",
			__FUNCTION__, __LINE__);
}
#endif

static void hook_status_proc(CFRunLoopObserverRef observer, CFRunLoopActivity activity, void *info) {
	uint64_t timestamp = mach_absolute_time();

	switch (activity) {
		case kCFRunLoopEntry:
			// Populate the hook start event.
			event.time = timestamp;
			event.reserved = 0x00;

			event.type = EVENT_HOOK_ENABLED;
			event.mask = 0x00;

			// Fire the hook start event.
			dispatch_event(&event);
			break;

		case kCFRunLoopExit:
			// Populate the hook stop event.
			event.time = timestamp;
			event.reserved = 0x00;

			event.type = EVENT_HOOK_DISABLED;
			event.mask = 0x00;

			// Fire the hook stop event.
			dispatch_event(&event);
			break;

		default:
			logger(LOG_LEVEL_WARN,	"%s [%u]: Unhandled RunLoop activity! (%#X)\n",
					__FUNCTION__, __LINE__, (unsigned int) activity);
			break;
	}
}

static inline void process_key_pressed(uint64_t timestamp, CGEventRef event_ref) {
	UInt64 keycode = CGEventGetIntegerValueField(event_ref, kCGKeyboardEventKeycode);

	// Populate key pressed event.
	event.time = timestamp;
	event.reserved = 0x00;

	event.type = EVENT_KEY_PRESSED;
	event.mask = get_modifiers();

	event.data.keyboard.keycode = keycode_to_scancode(keycode);
	event.data.keyboard.rawcode = keycode;
	event.data.keyboard.keychar = CHAR_UNDEFINED;

	logger(LOG_LEVEL_INFO,	"%s [%u]: Key %#X pressed. (%#X)\n",
			__FUNCTION__, __LINE__, event.data.keyboard.keycode, event.data.keyboard.rawcode);

	// Fire key pressed event.
	dispatch_event(&event);

	// If the pressed event was not consumed...
	if (event.reserved ^ 0x01) {
		tis_message->event = event_ref;
		tis_message->length = 0;
		bool is_runloop_main = CFEqual(event_loop, CFRunLoopGetMain());

		#ifdef USE_WEAK_IMPORT
		if (dispatch_sync_f != NULL && dispatch_get_main_queue != NULL && !is_runloop_main) {
			logger(LOG_LEVEL_DEBUG,	"%s [%u]: Using dispatch_sync_f for key typed events.\n", __FUNCTION__, __LINE__);
			dispatch_sync_f(dispatch_get_main_queue(), tis_message, &keycode_to_lookup);
		}
		#else
		if (dispatch_sync_f_f != NULL && dispatch_get_main_queue_f != NULL && !is_runloop_main) {
			logger(LOG_LEVEL_DEBUG,	"%s [%u]: Using *dispatch_sync_f_f for key typed events.\n", __FUNCTION__, __LINE__);
			(*dispatch_sync_f_f)((*dispatch_get_main_queue_f)(), tis_message, &keycode_to_lookup);
		}
		#endif
		#if ! defined(USE_CARBON_LEGACY) && defined(USE_COREFOUNDATION)
		else if (!is_runloop_main) {
			// Lock for code dealing with the main runloop.
			pthread_mutex_lock(&msg_port_mutex);

			// Check to see if the main runloop is still running.
			// TOOD I would rather this be a check on hook_enable(),
			// but it makes the usage complicated by requiring a separate
			// thread for the main runloop and hook registration.
			CFStringRef mode = CFRunLoopCopyCurrentMode(CFRunLoopGetMain());
			if (mode != NULL) {
				CFRelease(mode);

				// Lookup the Unicode representation for this event.
				//CFRunLoopSourceContext context = { .version = 0 };
				//CFRunLoopSourceGetContext(src_msg_port, &context);

				// Get the run loop context info pointer.
				//TISMessage *info = (TISMessage *) context.info;

				// Set the event pointer.
				//info->event = event_ref;

				// Signal the custom source and wakeup the main runloop.
				CFRunLoopSourceSignal(src_msg_port);
				CFRunLoopWakeUp(CFRunLoopGetMain());

				// Wait for a lock while the main runloop processes they key typed event.
				pthread_cond_wait(&msg_port_cond, &msg_port_mutex);
			} else {
				logger(LOG_LEVEL_WARN,	"%s [%u]: Failed to signal RunLoop main!\n",
						__FUNCTION__, __LINE__);
			}

			// Unlock for code dealing with the main runloop.
			pthread_mutex_unlock(&msg_port_mutex);
		}
		#endif
		else {
			keycode_to_lookup(tis_message);
		}
		unsigned int i;
		for (i= 0; i < tis_message->length; i++) {
			// Populate key typed event.
			event.time = timestamp;
			event.reserved = 0x00;

			event.type = EVENT_KEY_TYPED;
			event.mask = get_modifiers();

			event.data.keyboard.keycode = VC_UNDEFINED;
			event.data.keyboard.rawcode = keycode;
			event.data.keyboard.keychar = tis_message->buffer[i];

			logger(LOG_LEVEL_INFO,	"%s [%u]: Key %#X typed. (%lc)\n",
					__FUNCTION__, __LINE__, event.data.keyboard.keycode,
					(wint_t) event.data.keyboard.keychar);

			// Populate key typed event.
			dispatch_event(&event);
		}
	}
}

static inline void process_key_released(uint64_t timestamp, CGEventRef event_ref) {
	UInt64 keycode = CGEventGetIntegerValueField(event_ref, kCGKeyboardEventKeycode);

	// Populate key released event.
	event.time = timestamp;
	event.reserved = 0x00;

	event.type = EVENT_KEY_RELEASED;
	event.mask = get_modifiers();

	event.data.keyboard.keycode = keycode_to_scancode(keycode);
	event.data.keyboard.rawcode = keycode;
	event.data.keyboard.keychar = CHAR_UNDEFINED;

	logger(LOG_LEVEL_INFO,	"%s [%u]: Key %#X released. (%#X)\n",
			__FUNCTION__, __LINE__, event.data.keyboard.keycode, event.data.keyboard.rawcode);

	// Fire key released event.
	dispatch_event(&event);
}

static inline void process_modifier_changed(uint64_t timestamp, CGEventRef event_ref) {
	CGEventFlags event_mask = CGEventGetFlags(event_ref);
	UInt64 keycode = CGEventGetIntegerValueField(event_ref, kCGKeyboardEventKeycode);

	logger(LOG_LEVEL_INFO,	"%s [%u]: Modifiers Changed for key %#X. (%#X)\n",
			__FUNCTION__, __LINE__, (unsigned long) keycode, (unsigned int) event_mask);

	/* Because Apple treats modifier keys differently than normal key
	 * events, any changes to the modifier keys will require a key state
	 * change to be fired manually.
	 *
	 * NOTE Left and right keyboard masks like NX_NEXTLSHIFTKEYMASK exist and
	 * appear to be in use on Darwin, however they are removed by comment or
	 * preprocessor with a note that reads "device-dependent (really?)."  To
	 * ensure compatability, we will do this the verbose way.
	 *
	 * NOTE The masks for scroll and number lock are set in the key event.
	 */
	if (keycode == kVK_Shift) {
		if (event_mask & kCGEventFlagMaskShift) {
			// Process as a key pressed event.
			set_modifier_mask(MASK_SHIFT_L);
			process_key_pressed(timestamp, event_ref);
		} else {
			// Process as a key released event.
			unset_modifier_mask(MASK_SHIFT_L);
			process_key_released(timestamp, event_ref);
		}
	} else if (keycode == kVK_Control) {
		if (event_mask & kCGEventFlagMaskControl) {
			// Process as a key pressed event.
			set_modifier_mask(MASK_CTRL_L);
			process_key_pressed(timestamp, event_ref);
		} else {
			// Process as a key released event.
			unset_modifier_mask(MASK_CTRL_L);
			process_key_released(timestamp, event_ref);
		}
	} else if (keycode == kVK_Command) {
		if (event_mask & kCGEventFlagMaskCommand) {
			// Process as a key pressed event.
			set_modifier_mask(MASK_META_L);
			process_key_pressed(timestamp, event_ref);
		} else {
			// Process as a key released event.
			unset_modifier_mask(MASK_META_L);
			process_key_released(timestamp, event_ref);
		}
	} else if (keycode == kVK_Option) {
		if (event_mask & kCGEventFlagMaskAlternate) {
			// Process as a key pressed event.
			set_modifier_mask(MASK_ALT_L);
			process_key_pressed(timestamp, event_ref);
		} else {
			// Process as a key released event.
			unset_modifier_mask(MASK_ALT_L);
			process_key_released(timestamp, event_ref);
		}
	} else if (keycode == kVK_RightShift) {
		if (event_mask & kCGEventFlagMaskShift) {
			// Process as a key pressed event.
			set_modifier_mask(MASK_SHIFT_R);
			process_key_pressed(timestamp, event_ref);
		} else {
			// Process as a key released event.
			unset_modifier_mask(MASK_SHIFT_R);
			process_key_released(timestamp, event_ref);
		}
	} else if (keycode == kVK_RightControl) {
		if (event_mask & kCGEventFlagMaskControl) {
			// Process as a key pressed event.
			set_modifier_mask(MASK_CTRL_R);
			process_key_pressed(timestamp, event_ref);
		} else {
			// Process as a key released event.
			unset_modifier_mask(MASK_CTRL_R);
			process_key_released(timestamp, event_ref);
		}
	} else if (keycode == kVK_RightCommand) {
		if (event_mask & kCGEventFlagMaskCommand) {
			// Process as a key pressed event.
			set_modifier_mask(MASK_META_R);
			process_key_pressed(timestamp, event_ref);
		} else {
			// Process as a key released event.
			unset_modifier_mask(MASK_META_R);
			process_key_released(timestamp, event_ref);
		}
	} else if (keycode == kVK_RightOption) {
		if (event_mask & kCGEventFlagMaskAlternate) {
			// Process as a key pressed event.
			set_modifier_mask(MASK_ALT_R);
			process_key_pressed(timestamp, event_ref);
		} else {
			// Process as a key released event.
			unset_modifier_mask(MASK_ALT_R);
			process_key_released(timestamp, event_ref);
		}
	} else if (keycode == kVK_CapsLock) {
		if (current_modifiers & MASK_CAPS_LOCK) {
			// Process as a key pressed event.
			unset_modifier_mask(MASK_CAPS_LOCK);
			process_key_released(timestamp, event_ref);
		} else {
			// Process as a key released event.
			set_modifier_mask(MASK_CAPS_LOCK);
			process_key_pressed(timestamp, event_ref);
		}
	}
}

/* These events are totally undocumented for the CGEvent type, but are required to grab media and caps-lock keys.
 */
static inline void process_system_key(uint64_t timestamp, CGEventRef event_ref) {
	if( CGEventGetType(event_ref) == NX_SYSDEFINED) {
		#ifdef USE_OBJC
		// Contributed by Iván Munsuri Ibáñez <munsuri@gmail.com>
		id event_data = objc_msgSend((id) objc_getClass("NSEvent"), sel_registerName("eventWithCGEvent:"), event_ref);
		int subtype = (int) objc_msgSend(event_data, sel_registerName("subtype"));
		#else
		CFDataRef data = CGEventCreateData(kCFAllocatorDefault, event_ref);
		//CFIndex len = CFDataGetLength(data);
		UInt8 *buffer = malloc(12);
		// CFDataRef cf_data = CFDataCreate(NULL, [nsData bytes], [nsData length]);
		CFDataGetBytes(data, CFRangeMake(108, 12), buffer);
		UInt32 subtype = CFSwapInt32BigToHost(*((UInt32 *) buffer));
		#endif
		if (subtype == 8) {
			#ifdef USE_OBJC
			// int data = (int) objc_msgSend(event_data, sel_registerName("data1"));
			uint16_t data = (uint16_t) objc_msgSend(event_data, sel_registerName("data1"))
			#endif

			// int
			uint64_t key_code = ((uint64_t)data & 0xFFFF0000) >> 16;
			uint64_t key_flags = ((uint64_t)data & 0xFFFF); 
			//int key_state = (key_flags & 0xFF00) >> 8;
			bool key_down = (key_flags & 0x1) > 0;

			if (key_code == NX_KEYTYPE_CAPS_LOCK) {
				// It doesn't appear like we can modify the event coming in, so we will fabricate a new event.
				CGEventSourceRef src = CGEventSourceCreate(kCGEventSourceStateHIDSystemState);
				CGEventRef ns_event = CGEventCreateKeyboardEvent(src, kVK_CapsLock, key_down);
				CGEventSetFlags(ns_event, CGEventGetFlags(event_ref));

				if (key_down) {
					process_key_pressed(timestamp, ns_event);
				} else {
					process_key_released(timestamp, ns_event);
				}

				CFRelease(ns_event);
				CFRelease(src);
			} else if (key_code == NX_KEYTYPE_SOUND_UP) {
				// It doesn't appear like we can modify the event coming in, so we will fabricate a new event.
				CGEventSourceRef src = CGEventSourceCreate(kCGEventSourceStateHIDSystemState);
				CGEventRef ns_event = CGEventCreateKeyboardEvent(src, kVK_VolumeUp, key_down);
				CGEventSetFlags(ns_event, CGEventGetFlags(event_ref));

				if (key_down) {
					process_key_pressed(timestamp, ns_event);
				} else {
					process_key_released(timestamp, ns_event);
				}

				CFRelease(ns_event);
				CFRelease(src);
			} else if (key_code == NX_KEYTYPE_SOUND_DOWN) {
				// It doesn't appear like we can modify the event coming in, so we will fabricate a new event.
				CGEventSourceRef src = CGEventSourceCreate(kCGEventSourceStateHIDSystemState);
				CGEventRef ns_event = CGEventCreateKeyboardEvent(src, kVK_VolumeDown, key_down);
				CGEventSetFlags(ns_event, CGEventGetFlags(event_ref));

				if (key_down) {
					process_key_pressed(timestamp, ns_event);
				} else {
					process_key_released(timestamp, ns_event);
				}

				CFRelease(ns_event);
				CFRelease(src);
			} else if (key_code == NX_KEYTYPE_MUTE) {
				// It doesn't appear like we can modify the event coming in, so we will fabricate a new event.
				CGEventSourceRef src = CGEventSourceCreate(kCGEventSourceStateHIDSystemState);
				CGEventRef ns_event = CGEventCreateKeyboardEvent(src, kVK_Mute, key_down);
				CGEventSetFlags(ns_event, CGEventGetFlags(event_ref));

				if (key_down) {
					process_key_pressed(timestamp, ns_event);
				} else {
					process_key_released(timestamp, ns_event);
				}

				CFRelease(ns_event);
				CFRelease(src);
			} else if (key_code == NX_KEYTYPE_EJECT) {
				// It doesn't appear like we can modify the event coming in, so we will fabricate a new event.
				CGEventSourceRef src = CGEventSourceCreate(kCGEventSourceStateHIDSystemState);
				CGEventRef ns_event = CGEventCreateKeyboardEvent(src, kVK_NX_Eject, key_down);
				CGEventSetFlags(ns_event, CGEventGetFlags(event_ref));

				if (key_down) {
					process_key_pressed(timestamp, ns_event);
				} else {
					process_key_released(timestamp, ns_event);
				}

				CFRelease(ns_event);
				CFRelease(src);
			} else if (key_code == NX_KEYTYPE_PLAY) {
				// It doesn't appear like we can modify the event coming in, so we will fabricate a new event.
				CGEventSourceRef src = CGEventSourceCreate(kCGEventSourceStateHIDSystemState);
				CGEventRef ns_event = CGEventCreateKeyboardEvent(src, kVK_MEDIA_Play, key_down);
				CGEventSetFlags(ns_event, CGEventGetFlags(event_ref));

				if (key_down) {
					process_key_pressed(timestamp, ns_event);
				} else {
					process_key_released(timestamp, ns_event);
				}

				CFRelease(ns_event);
				CFRelease(src);
			} else if (key_code == NX_KEYTYPE_FAST) {
				// It doesn't appear like we can modify the event coming in, so we will fabricate a new event.
				CGEventSourceRef src = CGEventSourceCreate(kCGEventSourceStateHIDSystemState);
				CGEventRef ns_event = CGEventCreateKeyboardEvent(src, kVK_MEDIA_Next, key_down);
				CGEventSetFlags(ns_event, CGEventGetFlags(event_ref));

				if (key_down) {
					process_key_pressed(timestamp, ns_event);
				} else {
					process_key_released(timestamp, ns_event);
				}

				CFRelease(ns_event);
				CFRelease(src);
			} else if (key_code == NX_KEYTYPE_REWIND) {
				// It doesn't appear like we can modify the event coming in, so we will fabricate a new event.
				CGEventSourceRef src = CGEventSourceCreate(kCGEventSourceStateHIDSystemState);
				CGEventRef ns_event = CGEventCreateKeyboardEvent(src, kVK_MEDIA_Previous, key_down);
				CGEventSetFlags(ns_event, CGEventGetFlags(event_ref));

				if (key_down) {
					process_key_pressed(timestamp, ns_event);
				} else {
					process_key_released(timestamp, ns_event);
				}

				CFRelease(ns_event);
				CFRelease(src);
			}
		}

		#ifndef USE_OBJC
		free(buffer);
		CFRelease(data);
		#endif
	}
}


static inline void process_button_pressed(uint64_t timestamp, CGEventRef event_ref, uint16_t button) {
	// Track the number of clicks.
	if (button == click_button && (long int) (timestamp - click_time) <= hook_get_multi_click_time()) {
		if (click_count < USHRT_MAX) {
			click_count++;
		} else {
			logger(LOG_LEVEL_WARN, "%s [%u]: Click count overflow detected!\n",
					__FUNCTION__, __LINE__);
		}
	} else {
		// Reset the click count.
		click_count = 1;

		// Set the previous button.
		click_button = button;
	}

	// Save this events time to calculate the click_count.
	click_time = timestamp;

	CGPoint event_point = CGEventGetLocation(event_ref);

	// Populate mouse pressed event.
	event.time = timestamp;
	event.reserved = 0x00;

	event.type = EVENT_MOUSE_PRESSED;
	event.mask = get_modifiers();

	event.data.mouse.button = button;
	event.data.mouse.clicks = click_count;
	event.data.mouse.x = event_point.x;
	event.data.mouse.y = event_point.y;

	logger(LOG_LEVEL_INFO,	"%s [%u]: Button %u pressed %u time(s). (%u, %u)\n",
			__FUNCTION__, __LINE__, event.data.mouse.button, event.data.mouse.clicks,
			event.data.mouse.x, event.data.mouse.y);

	// Fire mouse pressed event.
	dispatch_event(&event);
}

static inline void process_button_released(uint64_t timestamp, CGEventRef event_ref, uint16_t button) {
	CGPoint event_point = CGEventGetLocation(event_ref);

	// Populate mouse released event.
	event.time = timestamp;
	event.reserved = 0x00;

	event.type = EVENT_MOUSE_RELEASED;
	event.mask = get_modifiers();

	event.data.mouse.button = button;
	event.data.mouse.clicks = click_count;
	event.data.mouse.x = event_point.x;
	event.data.mouse.y = event_point.y;

	logger(LOG_LEVEL_INFO,	"%s [%u]: Button %u released %u time(s). (%u, %u)\n",
			__FUNCTION__, __LINE__, event.data.mouse.button, event.data.mouse.clicks,
			event.data.mouse.x, event.data.mouse.y);

	// Fire mouse released event.
	dispatch_event(&event);

	// If the pressed event was not consumed...
	if (event.reserved ^ 0x01 && mouse_dragged != true) {
		// Populate mouse clicked event.
		event.time = timestamp;
		event.reserved = 0x00;

		event.type = EVENT_MOUSE_CLICKED;
		event.mask = get_modifiers();

		event.data.mouse.button = button;
		event.data.mouse.clicks = click_count;
		event.data.mouse.x = event_point.x;
		event.data.mouse.y = event_point.y;

		logger(LOG_LEVEL_INFO,	"%s [%u]: Button %u clicked %u time(s). (%u, %u)\n",
				__FUNCTION__, __LINE__, event.data.mouse.button, event.data.mouse.clicks,
				event.data.mouse.x, event.data.mouse.y);

		// Fire mouse clicked event.
		dispatch_event(&event);
	}

	// Reset the number of clicks.
	if (button == click_button && (long int) (event.time - click_time) > hook_get_multi_click_time()) {
		// Reset the click count.
		click_count = 0;
	}
}

static inline void process_mouse_moved(uint64_t timestamp, CGEventRef event_ref) {
	// Reset the click count.
	if (click_count != 0 && (long int) (timestamp - click_time) > hook_get_multi_click_time()) {
		click_count = 0;
	}

	CGPoint event_point = CGEventGetLocation(event_ref);

	// Populate mouse motion event.
	event.time = timestamp;
	event.reserved = 0x00;

	if (mouse_dragged) {
		event.type = EVENT_MOUSE_DRAGGED;
	} else {
		event.type = EVENT_MOUSE_MOVED;
	}
	event.mask = get_modifiers();

	event.data.mouse.button = MOUSE_NOBUTTON;
	event.data.mouse.clicks = click_count;
	event.data.mouse.x = event_point.x;
	event.data.mouse.y = event_point.y;

	logger(LOG_LEVEL_INFO,	"%s [%u]: Mouse %s to %u, %u.\n",
			__FUNCTION__, __LINE__, mouse_dragged ? "dragged" : "moved",
			event.data.mouse.x, event.data.mouse.y);

	// Fire mouse motion event.
	dispatch_event(&event);
}

static inline void process_mouse_wheel(uint64_t timestamp, CGEventRef event_ref) {
	// Reset the click count and previous button.
	click_count = 1;
	click_button = MOUSE_NOBUTTON;

	// Check to see what axis was rotated, we only care about axis 1 for vertical rotation.
	// TODO Implement horizontal scrolling by examining axis 2.
	// NOTE kCGScrollWheelEventDeltaAxis3 is currently unused.
	if (CGEventGetIntegerValueField(event_ref, kCGScrollWheelEventDeltaAxis1) != 0
			|| CGEventGetIntegerValueField(event_ref, kCGScrollWheelEventDeltaAxis2) != 0) {
		CGPoint event_point = CGEventGetLocation(event_ref);

		// Populate mouse wheel event.
		event.time = timestamp;
		event.reserved = 0x00;

		event.type = EVENT_MOUSE_WHEEL;
		event.mask = get_modifiers();

		event.data.wheel.clicks = click_count;
		event.data.wheel.x = event_point.x;
		event.data.wheel.y = event_point.y;

		// TODO Figure out if kCGScrollWheelEventDeltaAxis2 causes mouse events with zero rotation.
		if (CGEventGetIntegerValueField(event_ref, kCGScrollWheelEventIsContinuous) == 0) {
			// Scrolling data is line-based.
			event.data.wheel.type = WHEEL_BLOCK_SCROLL;
		} else {
			// Scrolling data is pixel-based.
			event.data.wheel.type = WHEEL_UNIT_SCROLL;
		}

		// TODO The result of kCGScrollWheelEventIsContinuous may effect this value.
		// Calculate the amount based on the Point Delta / Event Delta.  Integer sign should always be homogeneous resulting in a positive result.
		// NOTE kCGScrollWheelEventFixedPtDeltaAxis1 a floating point value (+0.1/-0.1) that takes acceleration into account.
		// NOTE kCGScrollWheelEventPointDeltaAxis1 will not build on OS X < 10.5

        if(CGEventGetIntegerValueField(event_ref, kCGScrollWheelEventDeltaAxis1) != 0) {
            event.data.wheel.amount = CGEventGetIntegerValueField(event_ref, kCGScrollWheelEventPointDeltaAxis1) / CGEventGetIntegerValueField(event_ref, kCGScrollWheelEventDeltaAxis1);

            // Scrolling data uses a fixed-point 16.16 signed integer format (Ex: 1.0 = 0x00010000).
            event.data.wheel.rotation = CGEventGetIntegerValueField(event_ref, kCGScrollWheelEventDeltaAxis1) * -1;

        } else if(CGEventGetIntegerValueField(event_ref, kCGScrollWheelEventDeltaAxis2) != 0) {
            event.data.wheel.amount = CGEventGetIntegerValueField(event_ref, kCGScrollWheelEventPointDeltaAxis2) / CGEventGetIntegerValueField(event_ref, kCGScrollWheelEventDeltaAxis2);

            // Scrolling data uses a fixed-point 16.16 signed integer format (Ex: 1.0 = 0x00010000).
            event.data.wheel.rotation = CGEventGetIntegerValueField(event_ref, kCGScrollWheelEventDeltaAxis2) * -1;
        } else {
            //Fail Silently if a 3rd axis gets added without changing this section of code.
            event.data.wheel.amount = 0;
            event.data.wheel.rotation = 0;
        }



		if (CGEventGetIntegerValueField(event_ref, kCGScrollWheelEventDeltaAxis1) != 0) {
			// Wheel Rotated Up or Down.
			event.data.wheel.direction = WHEEL_VERTICAL_DIRECTION;
		} else { 
			// data->event.u.u.detail == WheelLeft || data->event.u.u.detail == WheelRight
			// Wheel Rotated Left or Right.
			event.data.wheel.direction = WHEEL_HORIZONTAL_DIRECTION;
		}

		logger(LOG_LEVEL_INFO,	"%s [%u]: Mouse wheel type %u, rotated %i units in the %u direction at %u, %u.\n",
				__FUNCTION__, __LINE__, event.data.wheel.type,
				event.data.wheel.amount * event.data.wheel.rotation,
				event.data.wheel.direction,
				event.data.wheel.x, event.data.wheel.y);

		// Fire mouse wheel event.
		dispatch_event(&event);
	}
}

CGEventRef hook_event_proc(CGEventTapProxy tap_proxy, CGEventType type, CGEventRef event_ref, void *refcon) {
	// Get the local system time in UTC.
	gettimeofday(&system_time, NULL);

	// Grab the native event timestap for use later..
	uint64_t timestamp = (uint64_t) CGEventGetTimestamp(event_ref);

	// Get the event class.
	switch (type) {
		case kCGEventKeyDown:
			process_key_pressed(timestamp, event_ref);
			break;

		case kCGEventKeyUp:
			process_key_released(timestamp, event_ref);
			break;

		case kCGEventFlagsChanged:
			process_modifier_changed(timestamp, event_ref);
			break;

		// case NX_SYSDEFINED:
		// 	process_system_key(timestamp, event_ref);
		// 	break;

		case kCGEventLeftMouseDown:
			set_modifier_mask(MASK_BUTTON1);
			process_button_pressed(timestamp, event_ref, MOUSE_BUTTON1);
			break;

		case kCGEventRightMouseDown:
			set_modifier_mask(MASK_BUTTON2);
			process_button_pressed(timestamp, event_ref, MOUSE_BUTTON2);
			break;

		case kCGEventOtherMouseDown:
			// Extra mouse buttons.
			if (CGEventGetIntegerValueField(event_ref, kCGMouseEventButtonNumber) < UINT16_MAX) {
				uint16_t button = (uint16_t) CGEventGetIntegerValueField(event_ref, kCGMouseEventButtonNumber) + 1;

				// Add support for mouse 4 & 5.
				if (button == 4) {
					set_modifier_mask(MOUSE_BUTTON4);
				} else if (button == 5) {
					set_modifier_mask(MOUSE_BUTTON5);
				}

				process_button_pressed(timestamp, event_ref, button);
			}
			break;

		case kCGEventLeftMouseUp:
			unset_modifier_mask(MASK_BUTTON1);
			process_button_released(timestamp, event_ref, MOUSE_BUTTON1);
			break;

		case kCGEventRightMouseUp:
			unset_modifier_mask(MASK_BUTTON2);
			process_button_released(timestamp, event_ref, MOUSE_BUTTON2);
			break;

		case kCGEventOtherMouseUp:
			// Extra mouse buttons.
			if (CGEventGetIntegerValueField(event_ref, kCGMouseEventButtonNumber) < UINT16_MAX) {
				uint16_t button = (uint16_t) CGEventGetIntegerValueField(event_ref, kCGMouseEventButtonNumber) + 1;

				// Add support for mouse 4 & 5.
				if (button == 4) {
					unset_modifier_mask(MOUSE_BUTTON4);
				} else if (button == 5) {
					unset_modifier_mask(MOUSE_BUTTON5);
				}

				process_button_pressed(timestamp, event_ref, button);
			}
			break;


		case kCGEventLeftMouseDragged:
		case kCGEventRightMouseDragged:
		case kCGEventOtherMouseDragged:
			// FIXME The drag flag is confusing.  Use prev x,y to determine click.
			// Set the mouse dragged flag.
			mouse_dragged = true;
			process_mouse_moved(timestamp, event_ref);
			break;

		case kCGEventMouseMoved:
			// Set the mouse dragged flag.
			mouse_dragged = false;
			process_mouse_moved(timestamp, event_ref);
			break;


		case kCGEventScrollWheel:
			process_mouse_wheel(timestamp, event_ref);
			break;


		#ifdef USE_DEBUG
		case kCGEventNull:
			logger(LOG_LEVEL_DEBUG, "%s [%u]: Ignoring kCGEventNull.\n",
					__FUNCTION__, __LINE__);
			break;
		#endif

		default:
			// Check for an old OS X bug where the tap seems to timeout for no reason.
			// See: http://stackoverflow.com/questions/2969110/cgeventtapcreate-breaks-down-mysteriously-with-key-down-events#2971217
			if (type == (CGEventType) kCGEventTapDisabledByTimeout) {
				logger(LOG_LEVEL_WARN, "%s [%u]: CGEventTap timeout!\n",
						__FUNCTION__, __LINE__);

				// We need to restart the tap!
				restart_tap = true;
				CFRunLoopStop(CFRunLoopGetCurrent());
			} else {
				// In theory this *should* never execute.
				logger(LOG_LEVEL_DEBUG, "%s [%u]: Unhandled Darwin event: %#X.\n",
						__FUNCTION__, __LINE__, (unsigned int) type);
			}
			break;
	}

	CGEventRef result_ref = NULL;
	if (event.reserved ^ 0x01) {
		result_ref = event_ref;
	} else {
		logger(LOG_LEVEL_DEBUG,	"%s [%u]: Consuming the current event. (%#X) (%#p)\n",
				__FUNCTION__, __LINE__, type, event_ref);
	}

	return result_ref;
}

IOHOOK_API int hook_run() {
	int status = IOHOOK_SUCCESS;

	// Check for accessibility each time we start the loop.
	if (is_accessibility_enabled()) {
		logger(LOG_LEVEL_DEBUG,	"%s [%u]: Accessibility API is enabled.\n",
			__FUNCTION__, __LINE__);

		do {
			// Reset the restart flag...
			restart_tap = false;

				// Initialize starting modifiers.
				initialize_modifiers();

				// Try and allocate memory for hook_info.
				hook_info *hook = malloc(sizeof(hook_info));
				if (hook != NULL) {
					// Setup the event mask to listen for.
					#ifdef USE_DEBUG
					CGEventMask event_mask = kCGEventMaskForAllEvents;
					#else
					CGEventMask event_mask =	CGEventMaskBit(kCGEventKeyDown) |
												CGEventMaskBit(kCGEventKeyUp) |
												CGEventMaskBit(kCGEventFlagsChanged) |

												CGEventMaskBit(kCGEventLeftMouseDown) |
												CGEventMaskBit(kCGEventLeftMouseUp) |
												CGEventMaskBit(kCGEventLeftMouseDragged) |

												CGEventMaskBit(kCGEventRightMouseDown) |
												CGEventMaskBit(kCGEventRightMouseUp) |
												CGEventMaskBit(kCGEventRightMouseDragged) |

												CGEventMaskBit(kCGEventOtherMouseDown) |
												CGEventMaskBit(kCGEventOtherMouseUp) |
												CGEventMaskBit(kCGEventOtherMouseDragged) |

												CGEventMaskBit(kCGEventMouseMoved) |
												CGEventMaskBit(kCGEventScrollWheel) |

												// NOTE This event is undocumented and used
												// for caps-lock release and multi-media keys.
												CGEventMaskBit(NX_SYSDEFINED);
					#endif

					// Create the event tap.
					hook->port = CGEventTapCreate(
							kCGSessionEventTap,			// kCGHIDEventTap
							kCGHeadInsertEventTap,		// kCGTailAppendEventTap
							kCGEventTapOptionDefault,	// kCGEventTapOptionListenOnly See Bug #22
							event_mask,
							hook_event_proc,
							NULL);

					if (hook->port != NULL) {
						logger(LOG_LEVEL_DEBUG,	"%s [%u]: CGEventTapCreate Successful.\n",
								__FUNCTION__, __LINE__);

						// Create the runloop event source from the event tap.
						hook->source = CFMachPortCreateRunLoopSource(kCFAllocatorDefault, hook->port, 0);
						if (hook->source != NULL) {
							logger(LOG_LEVEL_DEBUG,	"%s [%u]: CFMachPortCreateRunLoopSource successful.\n",
									__FUNCTION__, __LINE__);

							event_loop = CFRunLoopGetCurrent();
							if (event_loop != NULL) {
								logger(LOG_LEVEL_DEBUG,	"%s [%u]: CFRunLoopGetCurrent successful.\n",
										__FUNCTION__, __LINE__);

								// Create run loop observers.
								hook->observer = CFRunLoopObserverCreate(
										kCFAllocatorDefault,
										kCFRunLoopEntry | kCFRunLoopExit, //kCFRunLoopAllActivities,
										true,
										0,
										hook_status_proc,
										NULL);

								if (hook->observer != NULL) {
									logger(LOG_LEVEL_DEBUG,	"%s [%u]: CFRunLoopObserverCreate successful.\n",
											__FUNCTION__, __LINE__);

									tis_message = (TISMessage *) calloc(1, sizeof(TISMessage));
									if (tis_message != NULL) {
										if (! CFEqual(event_loop, CFRunLoopGetMain())) {
											#ifdef USE_WEAK_IMPORT
											if (dispatch_sync_f == NULL || dispatch_get_main_queue == NULL) {
											#else
											*(void **) (&dispatch_sync_f_f) = dlsym(RTLD_DEFAULT, "dispatch_sync_f");
											const char *dlError = dlerror();
											if (dlError != NULL) {
												logger(LOG_LEVEL_DEBUG,	"%s [%u]: %s.\n",
														__FUNCTION__, __LINE__, dlError);
											}

											*(void **) (&dispatch_get_main_queue_f) = dlsym(RTLD_DEFAULT, "dispatch_get_main_queue");
											dlError = dlerror();
											if (dlError != NULL) {
												logger(LOG_LEVEL_DEBUG,	"%s [%u]: %s.\n",
														__FUNCTION__, __LINE__, dlError);
											}

											if (dispatch_sync_f_f == NULL || dispatch_get_main_queue_f == NULL) {
											#endif
												logger(LOG_LEVEL_DEBUG, "%s [%u]: Failed to locate dispatch_sync_f() or dispatch_get_main_queue()!\n",
														__FUNCTION__, __LINE__);

												#if ! defined(USE_CARBON_LEGACY) && defined(USE_COREFOUNDATION)
												logger(LOG_LEVEL_DEBUG, "%s [%u]: Falling back to runloop signaling.\n",
														__FUNCTION__, __LINE__);

												int runloop_status = start_message_port_runloop();
												if (runloop_status != IOHOOK_SUCCESS) {
													return runloop_status;
												}
												#endif
											}
										}

										// Add the event source and observer to the runloop mode.
										CFRunLoopAddSource(event_loop, hook->source, kCFRunLoopDefaultMode);
										CFRunLoopAddObserver(event_loop, hook->observer, kCFRunLoopDefaultMode);

										#ifdef USE_OBJC
										// Create a garbage collector to handle Cocoa events correctly.
										Class NSAutoreleasePool_class = (Class) objc_getClass("NSAutoreleasePool");
										id pool = class_createInstance(NSAutoreleasePool_class, 0);
										auto_release_pool = objc_msgSend(pool, sel_registerName("init"));
										#endif

										// Start the hook thread runloop.
										CFRunLoopRun();


										#ifdef USE_OBJC
										//objc_msgSend(auto_release_pool, sel_registerName("drain"));
										objc_msgSend(auto_release_pool, sel_registerName("release"));
										#endif

										// Lock back up until we are done processing the exit.
										if (CFRunLoopContainsObserver(event_loop, hook->observer, kCFRunLoopDefaultMode)) {
											CFRunLoopRemoveObserver(event_loop, hook->observer, kCFRunLoopDefaultMode);
										}

										if (CFRunLoopContainsSource(event_loop, hook->source, kCFRunLoopDefaultMode)) {
											CFRunLoopRemoveSource(event_loop, hook->source, kCFRunLoopDefaultMode);
										}

										#if ! defined(USE_CARBON_LEGACY) && defined(USE_COREFOUNDATION)
										if (! CFEqual(event_loop, CFRunLoopGetMain())) {
											#ifdef USE_WEAK_IMPORT
											if (dispatch_sync_f == NULL || dispatch_get_main_queue == NULL) {
											#else
											if (dispatch_sync_f_f == NULL || dispatch_get_main_queue_f == NULL) {
											#endif
												stop_message_port_runloop();
											}
										}
										#endif

										// Free the TIS Message.
										free(tis_message);
									} else {
										logger(LOG_LEVEL_ERROR, "%s [%u]: Failed to allocate memory for TIS message structure!\n",
												__FUNCTION__, __LINE__);

										// Set the exit status.
										status = IOHOOK_ERROR_OUT_OF_MEMORY;
									}

									// Invalidate and free hook observer.
									CFRunLoopObserverInvalidate(hook->observer);
									CFRelease(hook->observer);
								} else {
									// We cant do a whole lot of anything if we cant
									// create run loop observer.
									logger(LOG_LEVEL_ERROR,	"%s [%u]: CFRunLoopObserverCreate failure!\n",
											__FUNCTION__, __LINE__);

									// Set the exit status.
									status = IOHOOK_ERROR_CREATE_OBSERVER;
								}
							} else {
								logger(LOG_LEVEL_ERROR,	"%s [%u]: CFRunLoopGetCurrent failure!\n",
										__FUNCTION__, __LINE__);

								// Set the exit status.
								status = IOHOOK_ERROR_GET_RUNLOOP;
							}

							// Clean up the event source.
							CFRelease(hook->source);
						} else {
							logger(LOG_LEVEL_ERROR,	"%s [%u]: CFMachPortCreateRunLoopSource failure!\n",
									__FUNCTION__, __LINE__);

							// Set the exit status.
							status = IOHOOK_ERROR_CREATE_RUN_LOOP_SOURCE;
						}

						// Stop the CFMachPort from receiving any more messages.
						CFMachPortInvalidate(hook->port);
						CFRelease(hook->port);
					} else {
						logger(LOG_LEVEL_ERROR,	"%s [%u]: Failed to create event port!\n",
								__FUNCTION__, __LINE__);

						// Set the exit status.
						status = IOHOOK_ERROR_CREATE_EVENT_PORT;
					}

					// Free the hook structure.
					free(hook);
				} else {
					status = IOHOOK_ERROR_OUT_OF_MEMORY;
				}
		} while (restart_tap);
	} else {
		logger(LOG_LEVEL_ERROR,	"%s [%u]: Accessibility API is disabled!\n",
				__FUNCTION__, __LINE__);

		// Set the exit status.
		status = IOHOOK_ERROR_AXAPI_DISABLED;
	}

	logger(LOG_LEVEL_DEBUG,	"%s [%u]: Something, something, something, complete.\n",
			__FUNCTION__, __LINE__);

	return status;
}

IOHOOK_API int hook_stop() {
	int status = IOHOOK_FAILURE;

	CFStringRef mode = CFRunLoopCopyCurrentMode(event_loop);
	if (mode != NULL) {
		CFRelease(mode);

		// Make sure the tap doesn't restart.
		restart_tap = false;

		// Stop the run loop.
		CFRunLoopStop(event_loop);

		status = IOHOOK_SUCCESS;
	}

	logger(LOG_LEVEL_DEBUG,	"%s [%u]: Status: %#X.\n",
			__FUNCTION__, __LINE__, status);

	return status;
}