implement base service that all other services inherit from

src/service.c

diff --git a/src/service.c b/src/service.c
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index 0000000..929beff
--- /dev/null
+++ b/src/service.c
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+/* 
+ * service.c
+ * generic service implementation.
+ *
+ * Copyright (c) 2013 Nikias Bassen. All Rights Reserved.
+ *
+ * This library 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 2.1 of the License, or (at your option) any later version.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA 
+ */
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#include <stdlib.h>
+#include <string.h>
+
+#include "service.h"
+#include "idevice.h"
+#include "debug.h"
+
+/**
+ * Convert an idevice_error_t value to an service_error_t value.
+ * Used internally to get correct error codes.
+ *
+ * @param err An idevice_error_t error code
+ *
+ * @return A matching service_error_t error code,
+ *     SERVICE_E_UNKNOWN_ERROR otherwise.
+ */
+static service_error_t idevice_to_service_error(idevice_error_t err)
+{
+	switch (err) {
+		case IDEVICE_E_SUCCESS:
+			return SERVICE_E_SUCCESS;
+		case IDEVICE_E_INVALID_ARG:
+			return SERVICE_E_INVALID_ARG;
+		case IDEVICE_E_SSL_ERROR:
+			return SERVICE_E_SSL_ERROR;
+		default:
+			break;
+	}
+	return SERVICE_E_UNKNOWN_ERROR;
+}
+
+/**
+ * Creates a new service for the specified service descriptor.
+ * 
+ * @param device The device to connect to.
+ * @param service The service descriptor returned by lockdownd_start_service. 
+ * @param client Pointer that will be set to a newly allocated
+ *     service_client_t upon successful return.
+ *
+ * @return SERVICE_E_SUCCESS on success,
+ *     SERVICE_E_INVALID_ARG when one of the arguments is invalid,
+ *     or SERVICE_E_MUX_ERROR when connecting to the device failed.
+ */
+service_error_t service_client_new(idevice_t device, lockdownd_service_descriptor_t service, service_client_t *client)
+{
+	if (!device || (service->port == 0) || !client || *client)
+		return SERVICE_E_INVALID_ARG;
+
+	/* Attempt connection */
+	idevice_connection_t connection = NULL;
+	if (idevice_connect(device, service->port, &connection) != IDEVICE_E_SUCCESS) {
+		return SERVICE_E_MUX_ERROR;
+	}
+
+	/* create client object */
+	service_client_t client_loc = (service_client_t)malloc(sizeof(struct service_client_private));
+	client_loc->connection = connection;
+
+	/* enable SSL if requested */
+	if (service->ssl_enabled == 1)
+		service_enable_ssl(client_loc);
+
+	/* all done, return success */
+	*client = client_loc;
+	return SERVICE_E_SUCCESS;
+}
+
+/**
+ * Starts a new service on the specified device with given name and
+ * connects to it.
+ *
+ * @param device The device to connect to.
+ * @param service_name The name of the service to start.
+ * @param client Pointer that will point to a newly allocated service_client_t
+ *     upon successful return. Must be freed using service_client_free() after
+ *     use.
+ *
+ * @return SERVICE_E_SUCCESS on success, or a SERVICE_E_* error code
+ *     otherwise.
+ */
+service_error_t service_start_service(idevice_t device, const char* service_name, service_client_t *client)
+{
+	*client = NULL;
+
+	lockdownd_client_t lckd = NULL;
+	if (LOCKDOWN_E_SUCCESS != lockdownd_client_new_with_handshake(device, &lckd, NULL)) {
+		debug_info("Could not create a lockdown client.");
+		return SERVICE_E_START_SERVICE_ERROR;
+	}
+
+	lockdownd_service_descriptor_t service = NULL;
+	lockdownd_start_service(lckd, service_name, &service);
+	lockdownd_client_free(lckd);
+
+	if (service->port <= 0) {
+		debug_info("Could not start service %s!", service_name);
+		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;
+	}
+
+	if (service) {
+		lockdownd_service_descriptor_free(service);
+		service = NULL;
+	}
+
+	return SERVICE_E_SUCCESS;
+}
+
+/**
+ * Frees a service instance.
+ *
+ * @param client The service instance to free.
+ *
+ * @return SERVICE_E_SUCCESS on success,
+ *     SERVICE_E_INVALID_ARG when client is invalid, or a
+ *     SERVICE_E_UNKNOWN_ERROR when another error occured.
+ */
+service_error_t service_client_free(service_client_t client)
+{
+	if (!client)
+		return SERVICE_E_INVALID_ARG;
+
+	service_error_t err = idevice_to_service_error(idevice_disconnect(client->connection));
+	free(client);
+	return err;
+}
+
+/**
+ * Sends data using the given service client.
+ *
+ * @param client The service client to use for sending.
+ * @param data Data to send
+ * @param size Size of the data to send
+ * @param sent Number of bytes sent (can be NULL to ignore)
+ *
+ * @return SERVICE_E_SUCCESS on success,
+ *      SERVICE_E_INVALID_ARG when one or more parameters are
+ *      invalid, or SERVICE_E_UNKNOWN_ERROR when an unspecified
+ *      error occurs.
+ */
+service_error_t service_send(service_client_t client, const char* data, uint32_t size, uint32_t *sent)
+{
+	service_error_t res = SERVICE_E_UNKNOWN_ERROR;
+	int bytes = 0;
+
+	if (!client || (client && !client->connection) || !data || (size == 0)) {
+		return SERVICE_E_INVALID_ARG;
+	}
+
+	debug_info("sending %d bytes", size);
+	res = idevice_to_service_error(idevice_connection_send(client->connection, data, size, (uint32_t*)&bytes));
+	if (bytes <= 0) {
+		debug_info("ERROR: sending to device failed.");
+	}
+	if (sent) {
+		*sent = (uint32_t)bytes;
+	}
+
+	return res;
+}
+ 
+/**
+ * Receives data using the given service client with specified timeout.
+ *
+ * @param client The service client to use for receiving
+ * @param data Buffer that will be filled with the data received
+ * @param size Number of bytes to receive
+ * @param received Number of bytes received (can be NULL to ignore)
+ * @param timeout Maximum time in milliseconds to wait for data.
+ *
+ * @return SERVICE_E_SUCCESS on success,
+ *      SERVICE_E_INVALID_ARG when one or more parameters are
+ *      invalid, SERVICE_E_MUX_ERROR when a communication error
+ *      occurs, or SERVICE_E_UNKNOWN_ERROR when an unspecified
+ *      error occurs.
+ */
+service_error_t service_receive_with_timeout(service_client_t client, char* data, uint32_t size, uint32_t *received, unsigned int timeout)
+{
+	service_error_t res = SERVICE_E_UNKNOWN_ERROR;
+	int bytes = 0;
+
+	if (!client || (client && !client->connection) || !data || (size == 0)) {
+		return SERVICE_E_INVALID_ARG;
+	}
+
+	res = idevice_to_service_error(idevice_connection_receive_timeout(client->connection, data, size, (uint32_t*)&bytes, timeout));
+	if (bytes <= 0) {
+		debug_info("could not read data");
+	}
+	if (received) {
+		*received = (uint32_t)bytes;
+	}
+
+	return res;
+}
+
+/**
+ * Receives data using the given service client.
+ *
+ * @param client The service client to use for receiving
+ * @param data Buffer that will be filled with the data received
+ * @param size Number of bytes to receive
+ * @param received Number of bytes received (can be NULL to ignore)
+ *
+ * @return SERVICE_E_SUCCESS on success,
+ *      SERVICE_E_INVALID_ARG when one or more parameters are
+ *      invalid, SERVICE_E_MUX_ERROR when a communication error
+ *      occurs, or SERVICE_E_UNKNOWN_ERROR when an unspecified
+ *      error occurs.
+ */
+service_error_t service_receive(service_client_t client, char* data, uint32_t size, uint32_t *received)
+{
+	return service_receive_with_timeout(client, data, size, received, 10000);
+}
+
+/**
+ * Enable SSL for the given service client.
+ *
+ * @param client The connected service client for that SSL should be enabled.
+ *
+ * @return SERVICE_E_SUCCESS on success,
+ *     SERVICE_E_INVALID_ARG if client or client->connection is
+ *     NULL, SERVICE_E_SSL_ERROR when SSL could not be enabled,
+ *     or SERVICE_E_UNKNOWN_ERROR otherwise.
+ */
+service_error_t service_enable_ssl(service_client_t client)
+{
+	if (!client || !client->connection)
+		return SERVICE_E_INVALID_ARG;
+	return idevice_to_service_error(idevice_connection_enable_ssl(client->connection));
+}
+
+/**
+ * Disable SSL for the given service client.
+ *
+ * @param client The connected service client for that SSL should be disabled.
+ *
+ * @return SERVICE_E_SUCCESS on success,
+ *     SERVICE_E_INVALID_ARG if client or client->connection is
+ *     NULL, or SERVICE_E_UNKNOWN_ERROR otherwise.
+ */
+service_error_t service_disable_ssl(service_client_t client)
+{
+	if (!client || !client->connection)
+		return SERVICE_E_INVALID_ARG;
+	return idevice_to_service_error(idevice_connection_disable_ssl(client->connection));
+}
+