bind9.16/setup-named-chroot.sh

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2023-02-27 17:22:46 +00:00
#!/bin/bash
ROOTDIR="$1"
CONFIG_FILES="${3:-/etc/named-chroot.files}"
usage()
{
echo
echo 'This script setups chroot environment for BIND'
echo 'Usage: setup-named-chroot.sh ROOTDIR <on|off> [chroot.files]'
}
if ! [ "$#" -ge 2 -a "$#" -le 3 ]; then
echo 'Wrong number of arguments'
usage
exit 1
fi
# Exit if ROOTDIR doesn't exist
if ! [ -d "$ROOTDIR" ]; then
echo "Root directory $ROOTDIR doesn't exist"
usage
exit 1
fi
if ! [ -r "$CONFIG_FILES" ]; then
echo "Files list $CONFIG_FILES doesn't exist" 2>&1
usage
exit 1
fi
dev_create()
{
DEVNAME="$ROOTDIR/dev/$1"
shift
if ! [ -e "$DEVNAME" ]; then
/bin/mknod -m 0664 "$DEVNAME" $@
/bin/chgrp named "$DEVNAME"
if [ -x /usr/sbin/selinuxenabled -a -x /sbin/restorecon ]; then
/usr/sbin/selinuxenabled && /sbin/restorecon "$DEVNAME" > /dev/null || :
fi
fi
}
dev_chroot_prep()
{
dev_create random c 1 8
dev_create urandom c 1 9
dev_create zero c 1 5
dev_create null c 1 3
}
files_comment_filter()
{
if [ -d "$1" ]; then
grep -v '^[[:space:]]*#' "$1"/*.files
else
grep -v '^[[:space:]]*#' "$1"
fi
}
mount_chroot_conf()
{
if [ -n "$ROOTDIR" ]; then
# Check devices are prepared
dev_chroot_prep
files_comment_filter "$CONFIG_FILES" | while read -r all; do
# Skip nonexistant files
[ -e "$all" ] || continue
# If mount source is a file
if ! [ -d "$all" ]; then
# mount it only if it is not present in chroot or it is empty
if ! [ -e "$ROOTDIR$all" ] || [ `stat -c'%s' "$ROOTDIR$all"` -eq 0 ]; then
touch "$ROOTDIR$all"
mount --bind "$all" "$ROOTDIR$all"
fi
else
# Mount source is a directory. Mount it only if directory in chroot is
# empty.
if [ -e "$all" ] && [ `ls -1A $ROOTDIR$all | wc -l` -eq 0 ]; then
mount --bind --make-private "$all" "$ROOTDIR$all"
fi
fi
done
fi
}
umount_chroot_conf()
{
if [ -n "$ROOTDIR" ]; then
files_comment_filter "$CONFIG_FILES" | while read -r all; do
# Check if file is mount target. Do not use /proc/mounts because detecting
# of modified mounted files can fail.
if mount | grep -q '.* on '"$ROOTDIR$all"' .*'; then
umount "$ROOTDIR$all"
# Remove temporary created files
[ -f "$all" ] && rm -f "$ROOTDIR$all"
fi
done
fi
}
case "$2" in
on)
mount_chroot_conf
;;
off)
umount_chroot_conf
;;
*)
echo 'Second argument has to be "on" or "off"'
usage
exit 1
esac
exit 0