Implement "stop" command, and allow tincctl to retrieve a running tincd's PID.

src/control.c

@@ -35,15 +35,33 @@ extern char *controlsocketname;
 static void handle_control_data(int fd, short events, void *event) {
 	char buf[MAXBUFSIZE];
 	size_t inlen;
+	char *p;
 
 	inlen = read(fd, buf, sizeof buf);
 
-	if(inlen <= 0) {
-		logger(LOG_DEBUG, _("Closing control socket"));
-		event_del(event);
-		splay_delete(control_socket_tree, event);
-		close(fd);
+	if(inlen <= 0)
+		goto close;
+
+	p = memchr(buf, '\n', sizeof buf);
+	if(!p || p - buf + 1 != inlen)
+		goto malformed;
+
+	*p = 0;
+
+	if(!strcasecmp(buf, "stop")) {
+		logger(LOG_NOTICE, _("Got stop command"));
+		event_loopexit(NULL);
+		return;
 	}
+
+malformed:
+	logger(LOG_DEBUG, _("Malformed control command received"));
+
+close:
+	logger(LOG_DEBUG, _("Closing control socket"));
+	event_del(event);
+	splay_delete(control_socket_tree, event);
+	close(fd);
 }
 
 static void handle_new_control_socket(int fd, short events, void *data) {

src/tincctl.c

@@ -80,6 +80,7 @@ static void usage(bool status) {
 				"  stop                       Stop tincd.\n"
 				"  restart                    Restart tincd.\n"
 				"  reload                     Reload configuration of running tincd.\n"
+				"  pid                        Show PID of currently running tincd.\n"
 				"  generate-keys [bits]       Generate a new public/private keypair.\n"
 				"  dump                       Dump a list of one of the following things:\n"
 				"    nodes                    - all known nodes in the VPN\n"
@@ -326,7 +327,7 @@ static void make_names(void) {
 	}
 }
 
-int main(int argc, char **argv) {
+int main(int argc, char *argv[], char *envp[]) {
 	int fd;
 	struct sockaddr_un addr;
 	program_name = argv[0];
@@ -363,10 +364,21 @@ int main(int argc, char **argv) {
 		return 1;
 	}
 
+	// First handle commands that don't involve connecting to a running tinc daemon.
+
 	if(!strcasecmp(argv[optind], "generate-keys")) {
 		return !keygen(optind > argc ? atoi(argv[optind + 1]) : 1024);
 	}
 
+	if(!strcasecmp(argv[optind], "start")) {
+		argv[optind] = NULL;
+		execve("tincd", argv, envp);
+		fprintf(stderr, _("Could not start tincd: %s"), strerror(errno));
+		return 1;
+	}
+
+	// Now handle commands that do involve connecting to a running tinc daemon.
+
 	if(strlen(controlsocketname) >= sizeof addr.sun_path) {
 		fprintf(stderr, _("Control socket filename too long!\n"));
 		return 1;
@@ -387,7 +399,36 @@ int main(int argc, char **argv) {
 		return 1;
 	}
 
-	printf("Connected to %s.\n", controlsocketname);
+	struct ucred cred;
+	socklen_t credlen = sizeof cred;
+
+	if(getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &cred, &credlen) < 0) {
+		fprintf(stderr, _("Could not obtain PID: %s\n"), strerror(errno));
+		return 1;
+	}
+
+	if(!strcasecmp(argv[optind], "pid")) {
+		printf("%d\n", cred.pid);
+		return 0;
+	}
+
+	if(!strcasecmp(argv[optind], "stop")) {
+		write(fd, "stop\n", 5);
+		return 0;
+	}
+
+	if(!strcasecmp(argv[optind], "reload")) {
+		write(fd, "reload\n", 7);
+		return 0;
+	}
+	
+	if(!strcasecmp(argv[optind], "restart")) {
+		write(fd, "restart\n", 8);
+		return 0;
+	}
+
+	fprintf(stderr, _("Unknown command `%s'.\n"), argv[optind]);
+	usage(true);
 	
 	close(fd);