Check kernel version

git-svn-id: https://shorewall.svn.sourceforge.net/svnroot/shorewall/trunk@9024 fbd18981-670d-0410-9b5c-8dc0c1a9a2bb

Shorewall-common/releasenotes.txt

@@ -7,7 +7,7 @@ Shorewall 4.3.3
 
    Minimun system requirements:
 
-   - Kernel 2.6.20 or later with 2.6.25 or later strongly recommended.
+   - Kernel 2.6.23 or later with 2.6.25 or later strongly recommended.
    - iptables 1.4.0 or later with 1.4.1 strongly recommended.
    - Perl 5.10 if you wish to use DNS names in your IPv6 config files. 
      In that case you will also have to install Perl Socket6 support.
@@ -31,6 +31,10 @@ Other changes in 4.3.3
 
 3)  Traffic shaping is now enabled in Shorewall6. See below.
 
+4)  Shorewall6 and Shorewall6 Lite now check the kernel version during
+    'start' processing. If the kernel version is less than 2.6.25, a 
+    fatal error is generated.
+
 Migration Issues.
 
    None.

Shorewall-perl/prog.footer6

@@ -64,6 +64,11 @@ COMMAND="$1"
 
 [ -n "${PRODUCT:=Shorewall6}" ]
 
+kernel=$(printf "%2d%02d%02d\n" $(echo $(uname -r) 2> /dev/null | sed 's/-.*//' | tr '.' ' ' ) | head -n1)
+if [ $kernel -lt 20625 ]; then
+    error_message "ERROR: $PRODUCT requires Linux kernel 2.6.25 or later"
+    status=2
+else 
     case "$COMMAND" in
 	start)
 	    [ $# -ne 1 ] && usage 2
@@ -196,5 +201,6 @@ case "$COMMAND" in
 	    usage 2
 	    ;;
     esac
+fi
 
 exit $status