Add protocol implementation for syslog_relay service

1 files changed, 304 insertions, 0 deletions

diff --git a/src/syslog_relay.c b/src/syslog_relay.c
new file mode 100644
index 0000000..807305b
--- /dev/null
+++ b/src/syslog_relay.c
@@ -0,0 +1,304 @@
+/*
+ * syslog_relay.c 
+ * com.apple.syslog_relay service implementation.
+ * 
+ * Copyright (c) 2013 Martin Szulecki 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 <string.h>
+#include <stdlib.h>
+
+#include "syslog_relay.h"
+#include "lockdown.h"
+#include "common/debug.h"
+
+struct syslog_relay_worker_thread {
+        syslog_relay_client_t client;
+        syslog_relay_receive_cb_t cbfunc;
+        void *user_data;
+};
+
+/**
+ * Convert a service_error_t value to a syslog_relay_error_t value.
+ * Used internally to get correct error codes.
+ *
+ * @param err An service_error_t error code
+ *
+ * @return A matching syslog_relay_error_t error code,
+ *     SYSLOG_RELAY_E_UNKNOWN_ERROR otherwise.
+ */
+static syslog_relay_error_t syslog_relay_error(service_error_t err)
+{
+        switch (err) {
+                case SERVICE_E_SUCCESS:
+                        return SYSLOG_RELAY_E_SUCCESS;
+                case SERVICE_E_INVALID_ARG:
+                        return SYSLOG_RELAY_E_INVALID_ARG;
+                case SERVICE_E_MUX_ERROR:
+                        return SYSLOG_RELAY_E_MUX_ERROR;
+                case SERVICE_E_SSL_ERROR:
+                        return SYSLOG_RELAY_E_SSL_ERROR;
+                default:
+                        break;
+        }
+        return SYSLOG_RELAY_E_UNKNOWN_ERROR;
+}
+
+/**
+ * Connects to the syslog_relay service on the specified device.
+ *
+ * @param device The device to connect to.
+ * @param service The service descriptor returned by lockdownd_start_service.
+ * @param client Pointer that will point to a newly allocated
+ *     syslog_relay_client_t upon successful return. Must be freed using
+ *     syslog_relay_client_free() after use.
+ *
+ * @return SYSLOG_RELAY_E_SUCCESS on success, SYSLOG_RELAY_E_INVALID_ARG when
+ *     client is NULL, or an SYSLOG_RELAY_E_* error code otherwise.
+ */
+syslog_relay_error_t syslog_relay_client_new(idevice_t device, lockdownd_service_descriptor_t service, syslog_relay_client_t * client)
+{
+        *client = NULL;
+
+        if (!device || !service || service->port == 0 || !client || *client) {
+                debug_info("Incorrect parameter passed to syslog_relay_client_new.");
+                return SYSLOG_RELAY_E_INVALID_ARG;
+        }
+
+        debug_info("Creating syslog_relay_client, port = %d.", service->port);
+
+        service_client_t parent = NULL;
+        syslog_relay_error_t ret = syslog_relay_error(service_client_new(device, service, &parent));
+        if (ret != SYSLOG_RELAY_E_SUCCESS) {
+                debug_info("Creating base service client failed. Error: %i", ret);
+                return ret;
+        }
+
+        syslog_relay_client_t client_loc = (syslog_relay_client_t) malloc(sizeof(struct syslog_relay_client_private));
+        client_loc->parent = parent;
+        client_loc->worker = (thread_t)NULL;
+
+        *client = client_loc;
+
+        debug_info("syslog_relay_client successfully created.");
+        return 0;
+}
+
+/**
+ * Starts a new syslog_relay service on the specified device and connects to it.
+ *
+ * @param device The device to connect to.
+ * @param client Pointer that will point to a newly allocated
+ *     syslog_relay_client_t upon successful return. Must be freed using
+ *     syslog_relay_client_free() after use.
+ * @param label The label to use for communication. Usually the program name.
+ *  Pass NULL to disable sending the label in requests to lockdownd.
+ *
+ * @return SYSLOG_RELAY_E_SUCCESS on success, or an SYSLOG_RELAY_E_* error
+ *     code otherwise.
+ */
+syslog_relay_error_t syslog_relay_client_start_service(idevice_t device, syslog_relay_client_t * client, const char* label)
+{
+        syslog_relay_error_t err = SYSLOG_RELAY_E_UNKNOWN_ERROR;
+        service_client_factory_start_service(device, SYSLOG_RELAY_SERVICE_NAME, (void**)client, label, SERVICE_CONSTRUCTOR(syslog_relay_client_new), &err);
+        return err;
+}
+
+/**
+ * Disconnects a syslog_relay client from the device and frees up the
+ * syslog_relay client data.
+ *
+ * @param client The syslog_relay client to disconnect and free.
+ *
+ * @return SYSLOG_RELAY_E_SUCCESS on success, SYSLOG_RELAY_E_INVALID_ARG when
+ *     client is NULL, or an SYSLOG_RELAY_E_* error code otherwise.
+ */
+syslog_relay_error_t syslog_relay_client_free(syslog_relay_client_t client)
+{
+        if (!client)
+                return SYSLOG_RELAY_E_INVALID_ARG;
+
+        syslog_relay_error_t err = syslog_relay_error(service_client_free(client->parent));
+        client->parent = NULL;
+        if (client->worker) {
+                debug_info("Joining syslog capture callback worker thread");
+                thread_join(client->worker);
+        }
+        free(client);
+
+        return err;
+}
+
+/**
+ * Sends data to the service.
+ *
+ * @param client The syslog_relay client
+ * @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 SYSLOG_RELAY_E_SUCCESS on success,
+ *  SYSLOG_RELAY_E_INVALID_ARG when client or plist is NULL
+ */
+syslog_relay_error_t syslog_relay_send(syslog_relay_client_t client, const char* data, uint32_t size, uint32_t *sent)
+{
+        syslog_relay_error_t res = SYSLOG_RELAY_E_UNKNOWN_ERROR;
+        int bytes = 0;
+
+        if (!client || !data || (size == 0)) {
+                return SYSLOG_RELAY_E_INVALID_ARG;
+        }
+
+        res = syslog_relay_error(service_send(client->parent, 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 from the service.
+ *
+ * @param client The syslog_relay client
+ * @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 SYSLOG_RELAY_E_SUCCESS on success,
+ *  SYSLOG_RELAY_E_INVALID_ARG when client or plist is NULL
+ */
+syslog_relay_error_t syslog_relay_receive(syslog_relay_client_t client, char* data, uint32_t size, uint32_t *received)
+{
+        return syslog_relay_receive_with_timeout(client, data, size, received, 1000);
+}
+
+/**
+ * Receives data using the given syslog_relay client with specified timeout.
+ *
+ * @param client The syslog_relay 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 SYSLOG_RELAY_E_SUCCESS on success,
+ *      SYSLOG_RELAY_E_INVALID_ARG when one or more parameters are
+ *      invalid, SYSLOG_RELAY_E_MUX_ERROR when a communication error
+ *      occurs, or SYSLOG_RELAY_E_UNKNOWN_ERROR when an unspecified
+ *      error occurs.
+ */
+syslog_relay_error_t syslog_relay_receive_with_timeout(syslog_relay_client_t client, char* data, uint32_t size, uint32_t *received, unsigned int timeout)
+{
+        syslog_relay_error_t res = SYSLOG_RELAY_E_UNKNOWN_ERROR;
+        int bytes = 0;
+
+        if (!client || !data || (size == 0)) {
+                return SYSLOG_RELAY_E_INVALID_ARG;
+        }
+
+        res = syslog_relay_error(service_receive_with_timeout(client->parent, data, size, (uint32_t*)&bytes, timeout));
+        if (bytes <= 0) {
+                debug_info("Could not read data, error %d", res);
+        }
+        if (received) {
+                *received = (uint32_t)bytes;
+        }
+
+        return res;
+}
+
+void *syslog_relay_worker(void *arg)
+{
+        service_error_t ret = SERVICE_E_UNKNOWN_ERROR;
+        struct syslog_relay_worker_thread *srwt = (struct syslog_relay_worker_thread*)arg;
+
+        if (!srwt)
+                return NULL;
+
+        debug_info("Running");
+
+        while (srwt->client->parent) {
+                char c;
+                uint32_t bytes = 0;
+                ret = syslog_relay_receive_with_timeout(srwt->client, &c, 1, &bytes, 0);
+                if (ret < 0 || (bytes != 1)) {
+                        debug_info("Connection to syslog relay interrupted");
+                        break;
+                }
+                if(c != 0) {
+                        srwt->cbfunc(c, srwt->user_data);
+                }
+        }
+
+        if (srwt) {
+                free(srwt);
+        }
+
+        debug_info("Exiting");
+
+        return NULL;
+}
+
+syslog_relay_error_t syslog_relay_start_capture(syslog_relay_client_t client, syslog_relay_receive_cb_t callback, void* user_data)
+{
+        if (!client || !callback)
+                return SYSLOG_RELAY_E_INVALID_ARG;
+
+        syslog_relay_error_t res = SYSLOG_RELAY_E_UNKNOWN_ERROR;
+
+        if (client->worker) {
+                debug_info("Another syslog capture thread appears to be running already.");
+                return res;
+        }
+
+        /* start worker thread */
+        struct syslog_relay_worker_thread *srwt = (struct syslog_relay_worker_thread*)malloc(sizeof(struct syslog_relay_worker_thread));
+        if (srwt) {
+                srwt->client = client;
+                srwt->cbfunc = callback;
+                srwt->user_data = user_data;
+
+                if (thread_create(&client->worker, syslog_relay_worker, srwt) == 0) {
+                        res = SYSLOG_RELAY_E_SUCCESS;
+                }
+        }
+
+        return res;
+}
+
+syslog_relay_error_t syslog_relay_stop_capture(syslog_relay_client_t client)
+{
+        if (client->worker) {
+                /* notify thread to finish */
+                service_client_t parent = client->parent;
+                client->parent = NULL;
+                /* join thread to make it exit */
+                thread_join(client->worker);
+                client->worker = (thread_t)NULL;
+                client->parent = parent;
+        }
+
+        return SYSLOG_RELAY_E_SUCCESS;
+}
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