[PATCH 1/6] conf, passt: Don't try to log to stderr after we close it

[Stefano Brivio <sbrivio@redhat.com>]

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>
---
 conf.c  | 3 +++
 passt.c | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/conf.c b/conf.c
index 94b3ed6..dbdbb62 100644
--- a/conf.c
+++ b/conf.c
@@ -1693,6 +1693,9 @@ 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)
-- 
@@ -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)
-- 
2.43.0