From ea5362ca2a20816e0591ee66ea33d3bdb9cd2434 Mon Sep 17 00:00:00 2001
From: Victor Laborie <victor@laborie.io>
Date: Thu, 17 Aug 2017 14:55:09 -0400
Subject: [PATCH] Add mount check when starting jail

---
 bkctld | 36 ++++++++++++++++++------------------
 1 file changed, 18 insertions(+), 18 deletions(-)

diff --git a/bkctld b/bkctld
index f9cadd5..65d8f6a 100755
--- a/bkctld
+++ b/bkctld
@@ -289,25 +289,25 @@ sub_start() {
 
 	echo "Start jail $jail"
 	cd "${JAILDIR}/${jail}"
-	mount -t proc "proc-${jail}" proc
-	mount -nt tmpfs "dev-${jail}" dev
-	mknod -m 622 dev/console c 5 1
-	mknod -m 666 dev/null c 1 3
-	mknod -m 666 dev/zero c 1 5
-	mknod -m 666 dev/ptmx c 5 2
-	mknod -m 666 dev/tty c 5 0
-	mknod -m 444 dev/random c 1 8
-	mknod -m 444 dev/urandom c 1 9
+	grep -q "${JAILDIR}/${jail}/proc" /proc/mounts || mount -t proc "proc-${jail}" proc
+	grep -q "${JAILDIR}/${jail}/dev" /proc/mounts || mount -nt tmpfs "dev-${jail}" dev
+	[ -e "dev/console" ] || mknod -m 622 dev/console c 5 1
+	[ -e "dev/null" ] || mknod -m 666 dev/null c 1 3
+	[ -e "dev/zero" ] || mknod -m 666 dev/zero c 1 5
+	[ -e "dev/ptmx" ] || mknod -m 666 dev/ptmx c 5 2
+	[ -e "dev/tty" ] || mknod -m 666 dev/tty c 5 0
+	[ -e "dev/random" ] || mknod -m 444 dev/random c 1 8
+	[ -e "dev/urandom" ] || mknod -m 444 dev/urandom c 1 9
 	chown root:tty dev/console dev/ptmx dev/tty
-	ln -s proc/self/fd dev/fd
-	ln -s proc/self/fd/0 dev/stdin
-	ln -s proc/self/fd/1 dev/stdout
-	ln -s proc/self/fd/2 dev/stderr
-	ln -s proc/kcore dev/core
-	mkdir dev/pts
-	mkdir dev/shm
-	mount -t devpts -o gid=4,mode=620 none dev/pts
-	mount -t tmpfs none dev/shm
+	ln -fs proc/self/fd dev/fd
+	ln -fs proc/self/fd/0 dev/stdin
+	ln -fs proc/self/fd/1 dev/stdout
+	ln -fs proc/self/fd/2 dev/stderr
+	ln -fs proc/kcore dev/core
+	mkdir -p dev/pts
+	mkdir -p dev/shm
+	grep -q "${JAILDIR}/${jail}/dev/pts" /proc/mounts || mount -t devpts -o gid=4,mode=620 none dev/pts
+	grep -q "${JAILDIR}/${jail}/dev/shm" /proc/mounts || mount -t tmpfs none dev/shm
 	chroot "${JAILDIR}/${jail}" /usr/sbin/sshd -E /var/log/authlog
 }