turn service_client_start_service into service_client_factory_start_service

src/heartbeat.c

diff --git a/src/heartbeat.c b/src/heartbeat.c
index 817c6ad..0f8d2f3 100644
--- a/src/heartbeat.c
+++ b/src/heartbeat.c
@@ -112,36 +112,9 @@
  */
 heartbeat_error_t heartbeat_client_start_service(idevice_t device, heartbeat_client_t * client, const char* label)
 {
-	*client = NULL;
-
-	lockdownd_client_t lckd = NULL;
-	if (LOCKDOWN_E_SUCCESS != lockdownd_client_new_with_handshake(device, &lckd, label)) {
-		idevice_free(device);
-		debug_info("Could not create a lockdown client.");
-		return HEARTBEAT_E_UNKNOWN_ERROR;
-	}
-
-	lockdownd_service_descriptor_t service = NULL;
-	lockdownd_start_service(lckd, HEARTBEAT_SERVICE_NAME, &service);
-	lockdownd_client_free(lckd);
-
-	if (service->port <= 0) {
-		debug_info("Could not start heartbeat service!");
-		return HEARTBEAT_E_UNKNOWN_ERROR;
-	}
-
-	heartbeat_error_t res = heartbeat_client_new(device, service, client);
-	if (res != HEARTBEAT_E_SUCCESS) {
-		debug_info("Could not connect to heartbeat! Port: %i, error: %i", service->port, res);
-		return res;
-	}
-
-	if (service) {
-		lockdownd_service_descriptor_free(service);
-		service = NULL;
-	}
-
-	return HEARTBEAT_E_SUCCESS;
+	heartbeat_error_t err = HEARTBEAT_E_UNKNOWN_ERROR;
+	service_client_factory_start_service(device, HEARTBEAT_SERVICE_NAME, (void**)client, label, SERVICE_CONSTRUCTOR(heartbeat_client_new), &err);
+	return err;
 }
 
 /**

src/service.c

diff --git a/src/service.c b/src/service.c
index af37a83..738db02 100644
--- a/src/service.c
+++ b/src/service.c
@@ -103,7 +103,7 @@
  * @return SERVICE_E_SUCCESS on success, or a SERVICE_E_* error code
  *     otherwise.
  */
-service_error_t service_client_start_service(idevice_t device, const char* service_name, service_client_t *client, const char* label)
+service_error_t service_client_factory_start_service(idevice_t device, const char* service_name, void **client, const char* label, uint16_t (*constructor_func)(idevice_t, lockdownd_service_descriptor_t, void**), uint16_t *error_code)
 {
 	*client = NULL;
 
@@ -122,18 +122,24 @@
 		return SERVICE_E_START_SERVICE_ERROR;
 	}
 
-	service_error_t res = service_client_new(device, service, client);
-	if (res != SERVICE_E_SUCCESS) {
-		debug_info("Could not connect to service %s! Port: %i, error: %i", service_name, service->port, res);
-		return res;
+	uint16_t ec;
+	if (constructor_func) {
+		ec = (uint16_t)constructor_func(device, service, client);
+	} else {
+		ec = service_client_new(device, service, (service_client_t*)client);
+	}
+	if (error_code) {
+		*error_code = ec;
 	}
 
-	if (service) {
-		lockdownd_service_descriptor_free(service);
-		service = NULL;
+	if (ec != SERVICE_E_SUCCESS) {
+		debug_info("Could not connect to service %s! Port: %i, error: %i", service_name, service->port, ec);
 	}
 
-	return SERVICE_E_SUCCESS;
+	lockdownd_service_descriptor_free(service);
+	service = NULL;
+
+	return (ec == SERVICE_E_SUCCESS) ? SERVICE_E_SUCCESS : SERVICE_E_START_SERVICE_ERROR;
 }
 
 /**

src/service.h

diff --git a/src/service.h b/src/service.h
index 982f96a..3a22bed 100644
--- a/src/service.h
+++ b/src/service.h
@@ -40,9 +40,11 @@
 
 typedef int16_t service_error_t;
 
+#define SERVICE_CONSTRUCTOR(x) (uint16_t (*)(idevice_t, lockdownd_service_descriptor_t, void**))(x)
+
 /* creation and destruction */
 service_error_t service_client_new(idevice_t device, lockdownd_service_descriptor_t service, service_client_t *client);
-service_error_t service_client_start_service(idevice_t device, const char* service_name, service_client_t *client, const char* label);
+service_error_t service_client_factory_start_service(idevice_t device, const char* service_name, void **client, const char* label, uint16_t (*constructor_func)(idevice_t, lockdownd_service_descriptor_t, void**), uint16_t *error_code);
 service_error_t service_client_free(service_client_t client);
 
 /* sending */