Add udev mode of operation

When starting up, force background operation when in udev mode and
don't error out when already running.

When disconnecting, check if there are any devices left-over, and
exit if not.

Signed-off-by: Nikias Bassen <nikias@gmx.li>

1 files changed, 21 insertions, 4 deletions

diff --git a/src/main.c b/src/main.c
index ee633b6..de68242 100644
--- a/src/main.c
+++ b/src/main.c
@@ -58,6 +58,7 @@ static int verbose = DEBUG_LEVEL;
 static int foreground = 0;
 static int exit_on_no_devices = 0;
 static int drop_privileges = 0;
+static int udev = 0;
 
 struct device_info {
 	uint32_t device_id;
@@ -1030,6 +1031,7 @@ static void usage()
 	printf("\t-f|--foreground           do not daemonize\n");
 	printf("\t-e|--exit-on-no-devices   exit if no device is attached\n");
 	printf("\t-d|--drop-privileges      drop privileges after startup\n");
+	printf("\t-u|--udev                 use udev mode of operations\n");
 	printf("\n");
 }
 
@@ -1041,12 +1043,13 @@ static void parse_opts(int argc, char **argv)
 		{"verbose", 0, NULL, 'v'},
 		{"exit-on-no-devices", 0, NULL, 'e'},
 		{"drop-privileges", 0, NULL, 'd'},
+		{"udev", 0, NULL, 'u'},
 		{NULL, 0, NULL, 0}
 	};
 	int c;
 
 	while (1) {
-		c = getopt_long(argc, argv, "hfved", longopts, (int *) 0);
+		c = getopt_long(argc, argv, "hfvedu", longopts, (int *) 0);
 		if (c == -1) {
 			break;
 		}
@@ -1067,11 +1070,17 @@ static void parse_opts(int argc, char **argv)
 		case 'd':
 			drop_privileges = 1;
 			break;
+		case 'u':
+			udev = 1;
+			break;
 		default:
 			usage();
 			exit(2);
 		}
 	}
+
+	if (udev)
+		foreground = 0;
 }
 
 /**
@@ -1173,9 +1182,12 @@ int main(int argc, char **argv)
 		fcntl(fileno(lfd), F_GETLK, &lock);
 		fclose(lfd);
 		if (lock.l_type != F_UNLCK) {
-			logmsg(LOG_NOTICE,
-				   "another instance is already running. exiting.");
-			return -1;
+			if (!udev) {
+				logmsg(LOG_NOTICE,
+				       "another instance is already running. exiting.");
+				return -1;
+			}
+			return 0;
 		}
 	}
 
@@ -1265,6 +1277,7 @@ int main(int argc, char **argv)
 		if (result <= 0) {
 			if (result == 0) {
 				// cleanup
+				int num_children = 0;
 				for (i = 0; i < children_capacity; i++) {
 					if (children[i]) {
 						if (children[i]->dead != 0) {
@@ -1277,6 +1290,7 @@ int main(int argc, char **argv)
 							children[i] = NULL;
 							cnt++;
 						} else {
+							num_children++;
 							cnt = 0;
 						}
 					} else {
@@ -1284,6 +1298,9 @@ int main(int argc, char **argv)
 					}
 				}
 
+				if (num_children == 0 && udev)
+					break;
+
 				if ((children_capacity > DEFAULT_CHILDREN_CAPACITY)
 					&& ((children_capacity - cnt) <=
 						DEFAULT_CHILDREN_CAPACITY)) {