From 62617b89cf11da4b63b1760d50c6d3236882eb8b Mon Sep 17 00:00:00 2001
From: Culsu <fabian_sass@hotmail.de>
Date: Mon, 30 Nov 2020 22:22:36 +0100
Subject: [PATCH] added a security check for overwriting the hostname inside
 the jails rc.conf

---
 jaildk | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/jaildk b/jaildk
index f2086ca..f2c7d7f 100755
--- a/jaildk
+++ b/jaildk
@@ -764,7 +764,7 @@ Create a new jail from template."
 
 jaildk_create() {
     jail=$1
-    # $jail gets overwritten in jaildk_clone or somewhere...
+    # $jail gets overwritten in jaildk_clone or some subcall to .template :-( ...
     newjail=$jail
     
     src=.template
@@ -782,11 +782,11 @@ jaildk_create() {
     jaildk_clone -s $src -d $jail -o $srcversion -n $newversion
     # some perl magic to extract the hostname (if any) from /etc/jail.conf - and write it into the jails rc.conf
     jailhostname=$(cat /etc/jail.conf | tr -d '\t\r\n ' | perl -ne '$_ =~ /.*'"$newjail"'(\{(?:\{.*\}|[^{])*\})|\w+/; print $1;' | grep -oE 'hostname=[^;]+' | cut -d= -f2)
-    echo "new name: $jailhostname"
-    echo "in path $j/etc/$jail/local-etc-$newversion/rc.conf"
-    sed -iE 's/^hostname.*$/hostname="'"$jailhostname"'"/' $j/etc/$newjail/local-etc-$newversion/rc.conf
-    
-    
+    if [ -n "$jailhostname" ]; then
+        echo "new name: $jailhostname"
+        echo "in path $j/etc/$jail/local-etc-$newversion/rc.conf"
+        sed -iE 's/^hostname.*$/hostname="'"$jailhostname"'"/' $j/etc/$newjail/local-etc-$newversion/rc.conf
+    fi     
 }
 
 remove() {