X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Ftincctl.c;h=c6d4aac51dfb853baf60a393a7199916aa74b3bf;hp=46bf5bd5b034a147cd6f389a5822faa5d51ca8c6;hb=11868b890d1a7f4cfbfb37099393b32019010f66;hpb=7f96ef081dc0dc41e3955e35c1a36a62fd47f72b

diff --git a/src/tincctl.c b/src/tincctl.c
index 46bf5bd5..c6d4aac5 100644
--- a/src/tincctl.c
+++ b/src/tincctl.c
@@ -853,6 +853,13 @@ static int cmd_start(int argc, char *argv[]) {
 	}
 	return status;
 #else
+	int pfd[2] = {-1, -1};
+	if(pipe(pfd)) {
+		fprintf(stderr, "Could not create umbilical pipe: %s\n", strerror(errno));
+		free(nargv);
+		return 1;
+	}
+
 	pid_t pid = fork();
 	if(pid == -1) {
 		fprintf(stderr, "Could not fork: %s\n", strerror(errno));
@@ -860,8 +867,15 @@ static int cmd_start(int argc, char *argv[]) {
 		return 1;
 	}
 
-	if(!pid)
+	if(!pid) {
+		close(pfd[0]);
+		char buf[100] = "";
+		snprintf(buf, sizeof buf, "%d", pfd[1]);
+		setenv("TINC_UMBILICAL", buf, true);
 		exit(execvp(c, nargv));
+	} else {
+		close(pfd[1]);
+	}
 
 	free(nargv);
 
@@ -869,12 +883,33 @@ static int cmd_start(int argc, char *argv[]) {
 #ifdef SIGINT
 	signal(SIGINT, SIG_IGN);
 #endif
+
+	// Pass all log messages from the umbilical to stderr.
+	// A nul-byte right before closure means tincd started succesfully.
+	bool failure = true;
+	char buf[1024];
+	ssize_t len;
+
+	while((len = read(pfd[0], buf, sizeof buf)) > 0) {
+		failure = buf[len - 1];
+		if(!failure)
+			len--;
+		write(2, buf, len);
+	}
+
+	if(len)
+		failure = true;
+
+	close(pfd[0]);
+
+	// Make sure the child process is really gone.
 	result = waitpid(pid, &status, 0);
+
 #ifdef SIGINT
 	signal(SIGINT, SIG_DFL);
 #endif
 
-	if(result != pid || !WIFEXITED(status) || WEXITSTATUS(status)) {
+	if(failure || result != pid || !WIFEXITED(status) || WEXITSTATUS(status)) {
 		fprintf(stderr, "Error starting %s\n", c);
 		return 1;
 	}