Add config file parsing

Checks for a gamemode.ini in /usr/share/gamemode/ (or in the cwd for debugging)

	Currently allows for blacklisting and whitelisting clients based on rudimentary needle-haystack executable name checks

	See the example/gamemode.ini file for expected syntax

	Using the BSD licensed inih library (with additional meson.build file)

daemon/gamemode.c

@@ -32,6 +32,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #define _GNU_SOURCE
 
 #include "gamemode.h"
+#include "daemon_config.h"
 #include "governors.h"
 #include "logging.h"
 
@@ -56,6 +57,8 @@ struct GameModeContext {
 	_Atomic int refcount;    /**<Allow cycling the game mode */
 	GameModeClient *client;  /**<Pointer to first client */
 
+	GameModeConfig *config; /**<Pointer to config object */
+
 	bool performance_mode; /**<Only updates when we can */
 
 	/* Reaper control */
@@ -98,6 +101,10 @@ void game_mode_context_init(GameModeContext *self)
 	had_context_init = true;
 	self->refcount = ATOMIC_VAR_INIT(0);
 
+	/* Initialise the config */
+	self->config = config_create();
+	config_init(self->config);
+
 	/* Read current governer state before setting up any message handling */
 	update_initial_gov_state();
 	LOG_MSG("governor is set to [%s]\n", get_initial_governor());
@@ -139,6 +146,9 @@ void game_mode_context_destroy(GameModeContext *self)
 	pthread_cond_destroy(&self->reaper.condition);
 	pthread_mutex_destroy(&self->reaper.mutex);
 
+	/* Destroy the config object */
+	config_destroy(self->config);
+
 	pthread_rwlock_destroy(&self->rwlock);
 }
 
@@ -253,6 +263,15 @@ bool game_mode_context_register(GameModeContext *self, pid_t client)
 		return false;
 	}
 
+	/* Check our blacklist and whitelist */
+	if (!config_get_client_whitelisted(self->config, cl->executable)) {
+		LOG_MSG("Client [%s] was rejected (not in whitelist)\n", cl->executable);
+		return false;
+	} else if (config_get_client_blacklisted(self->config, cl->executable)) {
+		LOG_MSG("Client [%s] was rejected (in blacklist)\n", cl->executable);
+		return false;
+	}
+
 	/* Begin a write lock now to insert our new client at list start */
 	pthread_rwlock_wrlock(&self->rwlock);