Implemented option handling providing daemonization, verbosity, and logging to syslog

1 files changed, 121 insertions, 1 deletions

diff --git a/usbmuxd/main.c b/usbmuxd/main.c
index 90f7f22..3318ecd 100644
--- a/usbmuxd/main.c
+++ b/usbmuxd/main.c
@@ -33,17 +33,21 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <sys/stat.h>
+#include <getopt.h>
 
 #include "log.h"
 #include "usb.h"
 #include "device.h"
 #include "client.h"
 
-static const char *socket_path = "/var/run/usbmuxd"; //TODO: CHANGEME
+static const char *socket_path = "/var/run/usbmuxd";
 int should_exit;
 
 struct sigaction sa_old;
 
+static int verbose = 0;
+static int foreground = 0;
+
 int create_socket(void) {
         struct sockaddr_un bind_addr;
         int listenfd;
@@ -163,11 +167,116 @@ int main_loop(int listenfd)
         return 0;
 }
 
+/**
+ * make this program run detached from the current console
+ */
+static int daemonize()
+{
+        pid_t pid;
+        pid_t sid;
+
+        // already a daemon
+        if (getppid() == 1)
+                return 0;
+
+        pid = fork();
+        if (pid < 0) {
+                exit(EXIT_FAILURE);
+        }
+
+        if (pid > 0) {
+                // exit parent process
+                exit(EXIT_SUCCESS);
+        }
+        // At this point we are executing as the child process
+
+        // Change the file mode mask
+        umask(0);
+
+        // Create a new SID for the child process
+        sid = setsid();
+        if (sid < 0) {
+                return -1;
+        }
+        // Change the current working directory.
+        if ((chdir("/")) < 0) {
+                return -2;
+        }
+        // Redirect standard files to /dev/null
+        if (!freopen("/dev/null", "r", stdin)) {
+                usbmuxd_log(LL_ERROR, "ERROR: redirection of stdin failed.");
+        }
+        if (!freopen("/dev/null", "w", stdout)) {
+                usbmuxd_log(LL_ERROR, "ERROR: redirection of stdout failed.");
+        }
+        if (!freopen("/dev/null", "w", stderr)) {
+                usbmuxd_log(LL_ERROR, "ERROR: redirection of stderr failed.");
+        }
+
+        return 0;
+}
+
+static void usage()
+{
+        printf("usage: usbmuxd [options]\n");
+        printf("\t-h|--help                 Print this message.\n");
+        printf("\t-v|--verbose              Be verbose (use twice or more to increase).\n");
+        printf("\t-f|--foreground           Do not daemonize (implies a verbosity of 4).\n");
+        printf("\n");
+}
+
+static void parse_opts(int argc, char **argv)
+{
+        static struct option longopts[] = {
+                {"help", 0, NULL, 'h'},
+                {"foreground", 0, NULL, 'f'},
+                {"verbose", 0, NULL, 'v'},
+                {NULL, 0, NULL, 0}
+        };
+        int c;
+
+        while (1) {
+                c = getopt_long(argc, argv, "hfv", longopts, (int *) 0);
+                if (c == -1) {
+                        break;
+                }
+
+                switch (c) {
+                case 'h':
+                        usage();
+                        exit(0);
+                case 'f':
+                        foreground = 1;
+                        break;
+                case 'v':
+                        ++verbose;
+                        break;
+                default:
+                        usage();
+                        exit(2);
+                }
+        }
+}
+
 int main(int argc, char *argv[])
 {
         int listenfd;
         int res;
 
+        parse_opts(argc, argv);
+
+        argc -= optind;
+        argv += optind;
+
+        if (!foreground) {
+                log_enable_syslog();
+        } else {
+                verbose += LL_INFO;
+        }
+
+        /* set log level to specified verbosity */
+        log_level = verbose;
+
         usbmuxd_log(LL_NOTICE, "usbmux v0.1 starting up");
         should_exit = 0;
 
@@ -187,6 +296,15 @@ int main(int argc, char *argv[])
         
         usbmuxd_log(LL_NOTICE, "Initialization complete");
 
+        if (!foreground) {
+                if (daemonize() < 0) {
+                        fprintf(stderr, "usbmuxd: FATAL: Could not daemonize!\n");
+                        usbmuxd_log(LL_ERROR, "FATAL: Could not daemonize!");
+                        log_disable_syslog();
+                        exit(EXIT_FAILURE);
+                }
+        }
+        
         res = main_loop(listenfd);
         if(res < 0)
                 usbmuxd_log(LL_FATAL, "main_loop failed");
@@ -198,6 +316,8 @@ int main(int argc, char *argv[])
         client_shutdown();
         usbmuxd_log(LL_NOTICE, "Shutdown complete");
 
+        log_disable_syslog();
+
         if(res < 0)
                 return -res;
         return 0;