1 files changed, 248 insertions, 0 deletions
diff --git a/src/syslog_relay.c b/src/syslog_relay.c
new file mode 100644
index 0000000..9f4296e
--- /dev/null
+++ b/src/syslog_relay.c
@@ -0,0 +1,248 @@
+/*
+ * syslog_relay.c
+ * com.apple.syslog_relay service implementation.
+ *
+ * Copyright (c) 2019-2020 Nikias Bassen, All Rights Reserved.
+ * Copyright (c) 2013-2015 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;
+	int is_raw;
+};
+
+/**
+ * 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;
+		case SERVICE_E_NOT_ENOUGH_DATA:
+			return SYSLOG_RELAY_E_NOT_ENOUGH_DATA;
+		case SERVICE_E_TIMEOUT:
+			return SYSLOG_RELAY_E_TIMEOUT;
+		default:
+			break;
+	}
+	return SYSLOG_RELAY_E_UNKNOWN_ERROR;
+}
+
+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;
+}
+
+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;
+}
+
+syslog_relay_error_t syslog_relay_client_free(syslog_relay_client_t client)
+{
+	if (!client)
+		return SYSLOG_RELAY_E_INVALID_ARG;
+	syslog_relay_stop_capture(client);
+	syslog_relay_error_t err = syslog_relay_error(service_client_free(client->parent));
+	free(client);
+
+	return err;
+}
+
+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);
+}
+
+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 (res != SYSLOG_RELAY_E_SUCCESS && res != SYSLOG_RELAY_E_TIMEOUT && res != SYSLOG_RELAY_E_NOT_ENOUGH_DATA) {
+		debug_info("Could not read data, error %d", res);
+	}
+	if (received) {
+		*received = (uint32_t)bytes;
+	}
+
+	return res;
+}
+
+void *syslog_relay_worker(void *arg)
+{
+	syslog_relay_error_t ret = SYSLOG_RELAY_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, 100);
+		if (ret == SYSLOG_RELAY_E_TIMEOUT || ret == SYSLOG_RELAY_E_NOT_ENOUGH_DATA || ((bytes == 0) && (ret == SYSLOG_RELAY_E_SUCCESS))) {
+			continue;
+		}
+		if (ret < 0) {
+			debug_info("Connection to syslog relay interrupted");
+			break;
+		}
+		if (srwt->is_raw) {
+			srwt->cbfunc(c, srwt->user_data);
+		} else 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;
+		srwt->is_raw = 0;
+
+		if (thread_new(&client->worker, syslog_relay_worker, srwt) == 0) {
+			res = SYSLOG_RELAY_E_SUCCESS;
+		}
+	}
+
+	return res;
+}
+
+syslog_relay_error_t syslog_relay_start_capture_raw(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;
+		srwt->is_raw = 1;
+
+		if (thread_new(&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);
+		thread_free(client->worker);
+		client->worker = THREAD_T_NULL;
+		client->parent = parent;
+	}
+
+	return SYSLOG_RELAY_E_SUCCESS;
+}