| @@ -21,6 +21,7 @@
*
* Contributor(s):
* David PHAM-VAN <d.pham-van@ulteo.com> Ulteo SAS - http://www.ulteo.com
+ * Alex Bligh <alex@alex.org.uk>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
@@ -42,6 +43,9 @@
#include <string.h>
#include <signal.h>
#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <ctype.h>
#include <sys/socket.h>
#include <netdb.h>
@@ -57,6 +61,9 @@
#include "client.h"
#include "log.h"
+#define GUACD_DEV_NULL "/dev/null"
+#define GUACD_ROOT "/"
+
void guacd_handle_connection(int fd) {
guac_client* client;
@@ -170,10 +177,84 @@
/* Close socket */
guac_socket_close(socket);
- return;
+}
+
+int redirect_fd(int fd, int flags) {
+
+ /* Attempt to open bit bucket */
+ int new_fd = open(GUACD_DEV_NULL, flags);
+ if (new_fd < 0)
+ return 1;
+
+ /* If descriptor is different, redirect old to new and close new */
+ if (new_fd != fd) {
+ dup2(new_fd, fd);
+ close(new_fd);
+ }
+
+ return 0;
}
+int daemonize() {
+
+ pid_t pid;
+
+ /* Fork once to ensure we aren't the process group leader */
+ pid = fork();
+ if (pid < 0) {
+ guacd_log_error("Could not fork() parent: %s", strerror(errno));
+ return 1;
+ }
+
+ /* Exit if we are the parent */
+ if (pid > 0) {
+ guacd_log_info("Exiting and passing control to PID %i", pid);
+ _exit(0);
+ }
+
+ /* Start a new session (if not already group leader) */
+ setsid();
+
+ /* Fork again so the session group leader exits */
+ pid = fork();
+ if (pid < 0) {
+ guacd_log_error("Could not fork() group leader: %s", strerror(errno));
+ return 1;
+ }
+
+ /* Exit if we are the parent */
+ if (pid > 0) {
+ guacd_log_info("Exiting and passing control to PID %i", pid);
+ _exit(0);
+ }
+
+ /* Change to root directory */
+ if (chdir(GUACD_ROOT) < 0) {
+ guacd_log_error(
+ "Unable to change working directory to "
+ GUACD_ROOT);
+ return 1;
+ }
+
+ /* Reopen the 3 stdxxx to /dev/null */
+
+ if (redirect_fd(STDIN_FILENO, O_RDONLY)
+ || redirect_fd(STDOUT_FILENO, O_WRONLY)
+ || redirect_fd(STDERR_FILENO, O_WRONLY)) {
+
+ guacd_log_error(
+ "Unable to redirect standard file descriptors to "
+ GUACD_DEV_NULL);
+ return 1;
+ }
+
+ /* Success */
+ return 0;
+
+}
+
+
int main(int argc, char* argv[]) {
/* Server */
@@ -205,9 +286,6 @@
/* General */
int retval;
- /* Daemon Process */
- pid_t daemon_pid;
-
/* Parse arguments */
while ((opt = getopt(argc, argv, "l:b:p:f")) != -1) {
if (opt == 'l') {
@@ -237,12 +315,20 @@
/* 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(listen_address, listen_port, &hints, &addresses))) {
+ if ((retval = getaddrinfo(listen_address, listen_port,
+ &hints, &addresses))) {
+
guacd_log_error("Error parsing given address or port: %s",
gai_strerror(retval));
exit(EXIT_FAILURE);
+
}
/* Get socket */
@@ -253,8 +339,10 @@
}
/* 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));
+ 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 */
@@ -301,57 +389,49 @@
exit(EXIT_FAILURE);
}
+ /* Daemonize if requested */
if (!foreground) {
- /* Fork into background */
- daemon_pid = fork();
-
- /* If error, fail */
- if (daemon_pid == -1) {
- guacd_log_error("Error forking daemon process: %s", strerror(errno));
+ /* Attempt to daemonize process */
+ if (daemonize()) {
+ guacd_log_error("Could not become a daemon.");
exit(EXIT_FAILURE);
}
- /* If parent, write PID file and exit */
- else if (daemon_pid != 0) {
-
- if (pidfile != NULL) {
-
- /* Attempt to open pidfile and write PID */
- FILE* pidf = fopen(pidfile, "w");
- if (pidf) {
- fprintf(pidf, "%d\n", daemon_pid);
- fclose(pidf);
- }
-
- /* Warn on failure */
- else {
- guacd_log_error("Could not write PID file: %s", strerror(errno));
- exit(EXIT_FAILURE);
- }
+ }
- }
+ /* Write PID file if requested */
+ if (pidfile != NULL) {
- exit(EXIT_SUCCESS);
+ /* Attempt to open pidfile and write PID */
+ FILE* pidf = fopen(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);
}
- }
- /* Open log */
- openlog(NULL, LOG_PID, LOG_DAEMON);
+ }
/* 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.");
+ 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.");
+ guacd_log_info("Could not set handler for SIGCHLD to ignore. "
+ "Child processes may pile up in the process table.");
}
/* Log listening status */
- syslog(LOG_INFO,
- "Listening on host %s, port %s", bound_address, bound_port);
+ guacd_log_info("Listening on host %s, port %s", bound_address, bound_port);
/* Free addresses */
freeaddrinfo(addresses);
@@ -369,9 +449,12 @@
/* Accept connection */
client_addr_len = sizeof(client_addr);
- connected_socket_fd = accept(socket_fd, (struct sockaddr*) &client_addr, &client_addr_len);
+ 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));
+ guacd_log_error("Could not accept client connection: %s",
+ strerror(errno));
return 3;
}
@@ -399,7 +482,8 @@
/* 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));
+ guacd_log_error("Error closing daemon reference to "
+ "child descriptor: %s", strerror(errno));
}
}
|
