# HG changeset patch
# User Franz Glasner <fzglas.hg@dom66.de>
# Date 1661090101 -7200
# Node ID 4d7e00b500a1270e1c2d0f1189695cc2ff456f4b
# Parent  1b176ccd41b9b5fc6c8a4162b4c6feb1aaae12f5
Implement a sanity and consistency check when doing "natural" mounts

diff -r 1b176ccd41b9 -r 4d7e00b500a1 sbin/fjail
--- a/sbin/fjail	Sun Aug 21 15:18:20 2022 +0200
+++ b/sbin/fjail	Sun Aug 21 15:55:01 2022 +0200
@@ -446,6 +446,19 @@
                     _relative_mp="${_relative_mp%/}"
                     # The real effective full mountpoint
                     _real_mp="${_mountpoint}${_relative_mp}"
+
+                    #
+                    # Consistency and sanity check: computed real mountpoint must
+                    # be equal to the configured mountpoint when no custom mountpoint
+                    # is given.
+                    #
+                    if [ "${_mount_natural}" = "yes" ]; then
+                        if [ "${_real_mp}" != "${_mp}" ]; then
+                            echo "ERROR: mountpoint mismatch" >&2
+                            return 1
+                        fi
+                    fi
+
                     if [ "${_dry_run}" = "yes" ]; then
                         echo "Would mount ${_name} on ${_real_mp}"
                     else