int main(int argc, char* argv[]) {
/* Server */
int socket_fd;
struct addrinfo* addresses;
struct addrinfo* current_address;
char bound_address[1024];
char bound_port[64];
int opt_on = 1;
struct addrinfo hints = {
.ai_family = AF_UNSPEC,
.ai_socktype = SOCK_STREAM,
.ai_protocol = IPPROTO_TCP
};
/* Client */
struct sockaddr_in client_addr;
socklen_t client_addr_len;
int connected_socket_fd;
#ifdef ENABLE_SSL
SSL_CTX* ssl_context = NULL;
#endif
guacd_client_map* map = guacd_client_map_alloc();
/* General */
int retval;
/* Load configuration */
guacd_config* config = guacd_conf_load();
if (config == NULL || guacd_conf_parse_args(config, argc, argv))
exit(EXIT_FAILURE);
/* Set up logging prefix */
strncpy(log_prefix, basename(argv[0]), sizeof(log_prefix));
/* Open log as early as we can */
openlog(NULL, LOG_PID, LOG_DAEMON);
/* Log start */
guacd_log_info("Guacamole proxy daemon (guacd) version " VERSION);
/* Get addresses for binding */
if ((retval = getaddrinfo(config->bind_host, config->bind_port,
&hints, &addresses))) {
guacd_log_error("Error parsing given address or port: %s",
gai_strerror(retval));
exit(EXIT_FAILURE);
}
/* Get socket */
socket_fd = socket(AF_INET, SOCK_STREAM, 0);
if (socket_fd < 0) {
guacd_log_error("Error opening socket: %s", strerror(errno));
exit(EXIT_FAILURE);
}
/* Allow socket reuse */
if (setsockopt(socket_fd, SOL_SOCKET, SO_REUSEADDR,
(void*) &opt_on, sizeof(opt_on))) {
guacd_log_info("Unable to set socket options for reuse: %s",
strerror(errno));
}
/* Attempt binding of each address until success */
current_address = addresses;
while (current_address != NULL) {
int retval;
/* Resolve hostname */
if ((retval = getnameinfo(current_address->ai_addr,
current_address->ai_addrlen,
bound_address, sizeof(bound_address),
bound_port, sizeof(bound_port),
NI_NUMERICHOST | NI_NUMERICSERV)))
guacd_log_error("Unable to resolve host: %s",
gai_strerror(retval));
/* Attempt to bind socket to address */
if (bind(socket_fd,
current_address->ai_addr,
current_address->ai_addrlen) == 0) {
guacd_log_info("Successfully bound socket to "
"host %s, port %s", bound_address, bound_port);
/* Done if successful bind */
break;
}
/* Otherwise log information regarding bind failure */
else
guacd_log_info("Unable to bind socket to "
"host %s, port %s: %s",
bound_address, bound_port, strerror(errno));
current_address = current_address->ai_next;
}
/* If unable to bind to anything, fail */
if (current_address == NULL) {
guacd_log_error("Unable to bind socket to any addresses.");
exit(EXIT_FAILURE);
}
#ifdef ENABLE_SSL
/* Init SSL if enabled */
if (config->key_file != NULL || config->cert_file != NULL) {
/* Init SSL */
guacd_log_info("Communication will require SSL/TLS.");
SSL_library_init();
SSL_load_error_strings();
ssl_context = SSL_CTX_new(SSLv23_server_method());
/* Load key */
if (config->key_file != NULL) {
guacd_log_info("Using PEM keyfile %s", config->key_file);
if (!SSL_CTX_use_PrivateKey_file(ssl_context, config->key_file, SSL_FILETYPE_PEM)) {
guacd_log_error("Unable to load keyfile.");
exit(EXIT_FAILURE);
}
}
else
guacd_log_info("No PEM keyfile given - SSL/TLS may not work.");
/* Load cert file if specified */
if (config->cert_file != NULL) {
guacd_log_info("Using certificate file %s", config->cert_file);
if (!SSL_CTX_use_certificate_chain_file(ssl_context, config->cert_file)) {
guacd_log_error("Unable to load certificate.");
exit(EXIT_FAILURE);
}
}
else
guacd_log_info("No certificate file given - SSL/TLS may not work.");
}
#endif
/* Daemonize if requested */
if (!config->foreground) {
/* Attempt to daemonize process */
if (daemonize()) {
guacd_log_error("Could not become a daemon.");
exit(EXIT_FAILURE);
}
}
/* Write PID file if requested */
if (config->pidfile != NULL) {
/* Attempt to open pidfile and write PID */
FILE* pidf = fopen(config->pidfile, "w");
if (pidf) {
fprintf(pidf, "%d\n", getpid());
fclose(pidf);
}
/* Fail if could not write PID file*/
else {
guacd_log_error("Could not write PID file: %s", strerror(errno));
exit(EXIT_FAILURE);
}
}
/* Ignore SIGPIPE */
if (signal(SIGPIPE, SIG_IGN) == SIG_ERR) {
guacd_log_info("Could not set handler for SIGPIPE to ignore. "
"SIGPIPE may cause termination of the daemon.");
}
/* Ignore SIGCHLD (force automatic removal of children) */
if (signal(SIGCHLD, SIG_IGN) == SIG_ERR) {
guacd_log_info("Could not set handler for SIGCHLD to ignore. "
"Child processes may pile up in the process table.");
}
/* Log listening status */
guacd_log_info("Listening on host %s, port %s", bound_address, bound_port);
/* Free addresses */
freeaddrinfo(addresses);
/* Daemon loop */
for (;;) {
pid_t child_pid;
/* Listen for connections */
if (listen(socket_fd, 5) < 0) {
guacd_log_error("Could not listen on socket: %s", strerror(errno));
return 3;
}
/* Accept connection */
client_addr_len = sizeof(client_addr);
connected_socket_fd = accept(socket_fd,
(struct sockaddr*) &client_addr, &client_addr_len);
if (connected_socket_fd < 0) {
guacd_log_error("Could not accept client connection: %s",
strerror(errno));
return 3;
}
/*
* Once connection is accepted, send child into background.
*
* Note that we prefer fork() over threads for connection-handling
* processes as they give each connection its own memory area, and
* isolate the main daemon and other connections from errors in any
* particular client plugin.
*/
child_pid = fork();
/* If error, log */
if (child_pid == -1)
guacd_log_error("Error forking child process: %s", strerror(errno));
/* If child, start client, and exit when finished */
else if (child_pid == 0) {
guac_socket* socket;
#ifdef ENABLE_SSL
/* If SSL chosen, use it */
if (ssl_context != NULL) {
socket = guac_socket_open_secure(ssl_context, connected_socket_fd);
if (socket == NULL) {
guacd_log_guac_error("Error opening secure connection");
return 0;
}
}
else
socket = guac_socket_open(connected_socket_fd);
#else
/* Open guac_socket */
socket = guac_socket_open(connected_socket_fd);
#endif
guacd_handle_connection(map, socket);
close(connected_socket_fd);
return 0;
}
/* If parent, close reference to child's descriptor */
else if (close(connected_socket_fd) < 0) {
guacd_log_error("Error closing daemon reference to "
"child descriptor: %s", strerror(errno));
}
}
/* Close socket */
if (close(socket_fd) < 0) {
guacd_log_error("Could not close socket: %s", strerror(errno));
return 3;
}
return 0;
}
int main(int argc, char* argv[]) {
/* Server */
int socket_fd;
struct addrinfo* addresses;
struct addrinfo* current_address;
char bound_address[1024];
char bound_port[64];
int opt_on = 1;
struct addrinfo hints = {
.ai_family = AF_UNSPEC,
.ai_socktype = SOCK_STREAM,
.ai_protocol = IPPROTO_TCP
};
/* Client */
struct sockaddr_in client_addr;
socklen_t client_addr_len;
int connected_socket_fd;
#ifdef ENABLE_SSL
SSL_CTX* ssl_context = NULL;
#endif
guacd_proc_map* map = guacd_proc_map_alloc();
/* General */
int retval;
/* Load configuration */
guacd_config* config = guacd_conf_load();
if (config == NULL || guacd_conf_parse_args(config, argc, argv))
exit(EXIT_FAILURE);
/* Init logging as early as possible */
guacd_log_level = config->max_log_level;
openlog(GUACD_LOG_NAME, LOG_PID, LOG_DAEMON);
/* Log start */
guacd_log(GUAC_LOG_INFO, "Guacamole proxy daemon (guacd) version " VERSION " started");
/* Get addresses for binding */
if ((retval = getaddrinfo(config->bind_host, config->bind_port,
&hints, &addresses))) {
guacd_log(GUAC_LOG_ERROR, "Error parsing given address or port: %s",
gai_strerror(retval));
exit(EXIT_FAILURE);
}
/* Get socket */
socket_fd = socket(AF_INET, SOCK_STREAM, 0);
if (socket_fd < 0) {
guacd_log(GUAC_LOG_ERROR, "Error opening socket: %s", strerror(errno));
exit(EXIT_FAILURE);
}
/* Allow socket reuse */
if (setsockopt(socket_fd, SOL_SOCKET, SO_REUSEADDR,
(void*) &opt_on, sizeof(opt_on))) {
guacd_log(GUAC_LOG_WARNING, "Unable to set socket options for reuse: %s",
strerror(errno));
}
/* Attempt binding of each address until success */
current_address = addresses;
while (current_address != NULL) {
int retval;
/* Resolve hostname */
if ((retval = getnameinfo(current_address->ai_addr,
current_address->ai_addrlen,
bound_address, sizeof(bound_address),
bound_port, sizeof(bound_port),
NI_NUMERICHOST | NI_NUMERICSERV)))
guacd_log(GUAC_LOG_ERROR, "Unable to resolve host: %s",
gai_strerror(retval));
/* Attempt to bind socket to address */
if (bind(socket_fd,
current_address->ai_addr,
current_address->ai_addrlen) == 0) {
guacd_log(GUAC_LOG_DEBUG, "Successfully bound socket to "
"host %s, port %s", bound_address, bound_port);
/* Done if successful bind */
break;
}
/* Otherwise log information regarding bind failure */
else
guacd_log(GUAC_LOG_DEBUG, "Unable to bind socket to "
"host %s, port %s: %s",
bound_address, bound_port, strerror(errno));
current_address = current_address->ai_next;
}
/* If unable to bind to anything, fail */
if (current_address == NULL) {
guacd_log(GUAC_LOG_ERROR, "Unable to bind socket to any addresses.");
exit(EXIT_FAILURE);
}
#ifdef ENABLE_SSL
/* Init SSL if enabled */
if (config->key_file != NULL || config->cert_file != NULL) {
guacd_log(GUAC_LOG_INFO, "Communication will require SSL/TLS.");
#ifdef OPENSSL_REQUIRES_THREADING_CALLBACKS
/* Init threadsafety in OpenSSL */
guacd_openssl_init_locks(CRYPTO_num_locks());
CRYPTO_set_id_callback(guacd_openssl_id_callback);
CRYPTO_set_locking_callback(guacd_openssl_locking_callback);
#endif
/* Init SSL */
SSL_library_init();
SSL_load_error_strings();
ssl_context = SSL_CTX_new(SSLv23_server_method());
/* Load key */
if (config->key_file != NULL) {
guacd_log(GUAC_LOG_INFO, "Using PEM keyfile %s", config->key_file);
if (!SSL_CTX_use_PrivateKey_file(ssl_context, config->key_file, SSL_FILETYPE_PEM)) {
guacd_log(GUAC_LOG_ERROR, "Unable to load keyfile.");
exit(EXIT_FAILURE);
}
}
else
guacd_log(GUAC_LOG_WARNING, "No PEM keyfile given - SSL/TLS may not work.");
/* Load cert file if specified */
if (config->cert_file != NULL) {
guacd_log(GUAC_LOG_INFO, "Using certificate file %s", config->cert_file);
if (!SSL_CTX_use_certificate_chain_file(ssl_context, config->cert_file)) {
guacd_log(GUAC_LOG_ERROR, "Unable to load certificate.");
exit(EXIT_FAILURE);
}
}
else
guacd_log(GUAC_LOG_WARNING, "No certificate file given - SSL/TLS may not work.");
}
#endif
/* Daemonize if requested */
if (!config->foreground) {
/* Attempt to daemonize process */
if (daemonize()) {
guacd_log(GUAC_LOG_ERROR, "Could not become a daemon.");
exit(EXIT_FAILURE);
}
}
/* Write PID file if requested */
if (config->pidfile != NULL) {
/* Attempt to open pidfile and write PID */
FILE* pidf = fopen(config->pidfile, "w");
if (pidf) {
fprintf(pidf, "%d\n", getpid());
fclose(pidf);
}
/* Fail if could not write PID file*/
else {
guacd_log(GUAC_LOG_ERROR, "Could not write PID file: %s", strerror(errno));
exit(EXIT_FAILURE);
}
}
/* Ignore SIGPIPE */
if (signal(SIGPIPE, SIG_IGN) == SIG_ERR) {
guacd_log(GUAC_LOG_INFO, "Could not set handler for SIGPIPE to ignore. "
"SIGPIPE may cause termination of the daemon.");
}
/* Ignore SIGCHLD (force automatic removal of children) */
if (signal(SIGCHLD, SIG_IGN) == SIG_ERR) {
guacd_log(GUAC_LOG_INFO, "Could not set handler for SIGCHLD to ignore. "
"Child processes may pile up in the process table.");
}
/* Log listening status */
guacd_log(GUAC_LOG_INFO, "Listening on host %s, port %s", bound_address, bound_port);
/* Free addresses */
freeaddrinfo(addresses);
/* Listen for connections */
if (listen(socket_fd, 5) < 0) {
guacd_log(GUAC_LOG_ERROR, "Could not listen on socket: %s", strerror(errno));
return 3;
}
/* Daemon loop */
for (;;) {
pthread_t child_thread;
/* Accept connection */
client_addr_len = sizeof(client_addr);
connected_socket_fd = accept(socket_fd,
(struct sockaddr*) &client_addr, &client_addr_len);
if (connected_socket_fd < 0) {
guacd_log(GUAC_LOG_ERROR, "Could not accept client connection: %s", strerror(errno));
continue;
}
/* Create parameters for connection thread */
guacd_connection_thread_params* params = malloc(sizeof(guacd_connection_thread_params));
if (params == NULL) {
guacd_log(GUAC_LOG_ERROR, "Could not create connection thread: %s", strerror(errno));
continue;
}
params->map = map;
params->connected_socket_fd = connected_socket_fd;
#ifdef ENABLE_SSL
params->ssl_context = ssl_context;
#endif
/* Spawn thread to handle connection */
pthread_create(&child_thread, NULL, guacd_connection_thread, params);
pthread_detach(child_thread);
}
/* Close socket */
if (close(socket_fd) < 0) {
guacd_log(GUAC_LOG_ERROR, "Could not close socket: %s", strerror(errno));
return 3;
}
#ifdef ENABLE_SSL
if (ssl_context != NULL) {
#ifdef OPENSSL_REQUIRES_THREADING_CALLBACKS
guacd_openssl_free_locks(CRYPTO_num_locks());
#endif
SSL_CTX_free(ssl_context);
}
#endif
return 0;
}
