conf, passt: Don't try to log to stderr after we close it

If we don't run in foreground, we close standard error as we
daemonise, so it makes no sense to check if the controlling terminal
is an interactive terminal or if --force-stderr was given, to decide
if we want to log to standard error.

Make --force-stderr depend on --foreground.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

2 files changed, 4 insertions, 1 deletions

diff --git a/conf.c b/conf.c
index 4fff2b1..8687e43 100644
--- a/conf.c
+++ b/conf.c
@@ -1631,6 +1631,9 @@ void conf(struct ctx *c, int argc, char **argv)
 
 	conf_ugid(runas, &uid, &gid);
 
+	if (!c->foreground && c->force_stderr)
+		die("Can't log to standard error if not running in foreground");
+
 	if (logfile) {
 		logfile_init(c->mode == MODE_PASTA ? "pasta" : "passt",
 			     logfile, logsize);
diff --git a/passt.c b/passt.c
index a5e2c5a..aa9648a 100644
--- a/passt.c
+++ b/passt.c
@@ -302,7 +302,7 @@ int main(int argc, char **argv)
 	if (isolate_prefork(&c))
 		die("Failed to sandbox process, exiting");
 
-	if (!c.force_stderr && !isatty(fileno(stderr)))
+	if (!c.foreground || (!c.force_stderr && !isatty(fileno(stderr))))
 		__openlog(log_name, 0, LOG_DAEMON);
 
 	if (!c.foreground)