pasta: By default, quit if filesystem-bound net namespace goes away

This should be convenient for users managing filesystem-bound network
namespaces: monitor the base directory of the namespace and exit if
the namespace given as PATH or NAME target is deleted. We can't add
an inotify watch directly on the namespace directory, that won't work
with nsfs.

Add an option to disable this behaviour, --no-netns-quit.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/passt.c b/passt.c
index 67ad1c7..36f0161 100644
--- a/passt.c
+++ b/passt.c
@@ -301,7 +301,7 @@ void exit_handler(int signal)
  */
 int main(int argc, char **argv)
 {
-	int nfds, i, devnull_fd = -1, pidfile_fd = -1;
+	int nfds, i, devnull_fd = -1, pidfile_fd = -1, quit_fd;
 	struct epoll_event events[EPOLL_EVENTS];
 	struct ctx c = { 0 };
 	struct rlimit limit;
@@ -357,6 +357,8 @@ int main(int argc, char **argv)
 		exit(EXIT_FAILURE);
 	}
 
+	quit_fd = pasta_netns_quit_init(&c);
+
 	if (getrlimit(RLIMIT_NOFILE, &limit)) {
 		perror("getrlimit");
 		exit(EXIT_FAILURE);
@@ -416,6 +418,7 @@ int main(int argc, char **argv)
 	seccomp(&c);
 
 	timer_init(&c, &now);
+
 loop:
 	nfds = epoll_wait(c.epollfd, events, EPOLL_EVENTS, TIMER_INTERVAL);
 	if (nfds == -1 && errno != EINTR) {
@@ -431,6 +434,8 @@ loop:
 
 		if (fd == c.fd_tap || fd == c.fd_tap_listen)
 			tap_handler(&c, fd, events[i].events, &now);
+		else if (fd == quit_fd)
+			pasta_netns_quit_handler(&c, fd);
 		else
 			sock_handler(&c, ref, events[i].events, &now);
 	}