Fix support for more than one device with systemd by extending usbmuxd usage

Upon connecting a new device, usbmuxd was not notified to scan for it if
systemd was used as the activation method. This change introduces the
"--disable-hotplug" and "--enable-exit" options to have a finer control
over usbmuxd's signaling behavior. The convenience option "--systemd"
complements the "--udev" option and setups the right settings for systemd.

1 files changed, 41 insertions, 15 deletions

diff --git a/src/main.c b/src/main.c
index d277cd6..4de6446 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,6 +1,7 @@
 /*
  * main.c
  *
+ * Copyright (C) 2013-2014 Martin Szulecki <m.szulecki@libimobiledevice.org>
  * Copyright (C) 2009 Hector Martin <hector@marcansoft.com>
  * Copyright (C) 2009 Nikias Bassen <nikias@gmx.li>
  * Copyright (C) 2009 Paul Sladen <libiphone@paul.sladen.org>
@@ -58,7 +59,8 @@ static int verbose = 0;
 static int foreground = 0;
 static int drop_privileges = 0;
 static const char *drop_user = NULL;
-static int opt_udev = 0;
+static int opt_disable_hotplug = 0;
+static int opt_enable_exit = 0;
 static int opt_exit = 0;
 static int exit_signal = 0;
 static int daemon_pipe;
@@ -105,7 +107,7 @@ static void handle_signal(int sig)
                 usbmuxd_log(LL_NOTICE,"Caught signal %d, exiting", sig);
                 should_exit = 1;
         } else {
-                if(opt_udev) {
+                if(opt_enable_exit) {
                         if (sig == SIGUSR1) {
                                 usbmuxd_log(LL_INFO, "Caught SIGUSR1, checking if we can terminate (no more devices attached)...");
                                 if (device_get_count(1) > 0) {
@@ -120,7 +122,7 @@ static void handle_signal(int sig)
                                 should_discover = 1;
                         }
                 } else {
-                        usbmuxd_log(LL_INFO, "Caught SIGUSR1/2 but we weren't started in --udev mode, ignoring");
+                        usbmuxd_log(LL_INFO, "Caught SIGUSR1/2 but this instance was not started with \"--enable-exit\", ignoring.");
                 }
         }
 }
@@ -200,7 +202,7 @@ static int main_loop(int listenfd)
                                 }
                                 if(should_discover) {
                                         should_discover = 0;
-                                        usbmuxd_log(LL_INFO, "Device discovery triggered by udev");
+                                        usbmuxd_log(LL_INFO, "Device discovery triggered");
                                         usb_discover();
                                 }
                         }
@@ -351,11 +353,16 @@ static void usage()
         printf("  -v, --verbose\t\tBe verbose (use twice or more to increase).\n");
         printf("  -f, --foreground\tDo not daemonize (implies one -v).\n");
         printf("  -U, --user USER\tChange to this user after startup (needs USB privileges).\n");
-        printf("  -u, --udev\t\tRun in udev operation mode.\n");
-        printf("  -x, --exit\t\tTell a running instance to exit if there are no devices\n");
-        printf("            \t\tconnected (must be in udev mode).\n");
-        printf("  -X, --force-exit\tTell a running instance to exit, even if there are still\n");
-        printf("                  \tdevices connected (always works).\n");
+        printf("  -n, --disable-hotplug\tDisables automatic discovery of devices on hotplug.\n");
+        printf("                       \tStarting another instance will trigger discovery instead.\n");
+        printf("  -z, --enable-exit\tEnable \"--exit\" request from other instances and exit\n");
+        printf("                   \tautomatically if no device is attached.\n");
+        printf("  -u, --udev\t\tRun in udev operation mode (implies -n and -z).\n");
+        printf("  -s, --systemd\t\tRun in systemd operation mode (implies -z and -f).\n");
+        printf("  -x, --exit\t\tNotify a running instance to exit if there are no devices\n");
+        printf("            \t\tconnected (sends SIGUSR1 to running instance) and exit.\n");
+        printf("  -X, --force-exit\tNotify a running instance to exit even if there are still\n");
+        printf("                  \tdevices connected (always works) and exit.\n");
         printf("  -V, --version\t\tPrint version information and exit.\n");
         printf("\n");
 }
@@ -367,7 +374,10 @@ static void parse_opts(int argc, char **argv)
                 {"foreground", 0, NULL, 'f'},
                 {"verbose", 0, NULL, 'v'},
                 {"user", 1, NULL, 'U'},
+                {"disable-hotplug", 0, NULL, 'n'},
+                {"enable-exit", 0, NULL, 'z'},
                 {"udev", 0, NULL, 'u'},
+                {"systemd", 0, NULL, 's'},
                 {"exit", 0, NULL, 'x'},
                 {"force-exit", 0, NULL, 'X'},
                 {"version", 0, NULL, 'V'},
@@ -376,7 +386,7 @@ static void parse_opts(int argc, char **argv)
         int c;
 
         while (1) {
-                c = getopt_long(argc, argv, "hfvVuU:xX", longopts, (int *) 0);
+                c = getopt_long(argc, argv, "hfvVuU:xXsnz", longopts, (int *) 0);
                 if (c == -1) {
                         break;
                 }
@@ -399,7 +409,18 @@ static void parse_opts(int argc, char **argv)
                         drop_user = optarg;
                         break;
                 case 'u':
-                        opt_udev = 1;
+                        opt_disable_hotplug = 1;
+                        opt_enable_exit = 1;
+                        break;
+                case 's':
+                        opt_enable_exit = 1;
+                        foreground = 1;
+                        break;
+                case 'n':
+                        opt_disable_hotplug = 1;
+                        break;
+                case 'z':
+                        opt_enable_exit = 1;
                         break;
                 case 'x':
                         opt_exit = 1;
@@ -474,7 +495,7 @@ int main(int argc, char *argv[])
                                 goto terminate;
                         }
                 } else {
-                        if (!opt_udev) {
+                        if (!opt_disable_hotplug) {
                                 usbmuxd_log(LL_ERROR, "Another instance is already running (pid %d). exiting.", lock.l_pid);
                                 res = -1;
                         } else {
@@ -497,7 +518,7 @@ int main(int argc, char *argv[])
         unlink(lockfile);
 
         if (opt_exit) {
-                usbmuxd_log(LL_NOTICE, "No running instance found, none killed. exiting.");
+                usbmuxd_log(LL_NOTICE, "No running instance found, none killed. Exiting.");
                 goto terminate;
         }
 
@@ -635,8 +656,13 @@ int main(int argc, char *argv[])
                 if((res = notify_parent(0)) < 0)
                         goto terminate;
 
-        if(opt_udev)
-                usb_autodiscover(0); // discovery triggered by udev
+        if(opt_disable_hotplug) {
+                usbmuxd_log(LL_NOTICE, "Automatic device discovery on hotplug disabled.");
+                usb_autodiscover(0); // discovery to be triggered by new instance
+        }
+        if (opt_enable_exit) {
+                usbmuxd_log(LL_NOTICE, "Enabled exit on SIGUSR1 if no devices are attached. Start a new instance with \"--exit\" to trigger.");
+        }
 
         res = main_loop(listenfd);
         if(res < 0)