### -*-sh-*-
###
### ICMP filtering for firewall scripts
###
### (c) 2008 Mark Wooding
###

###----- Licensing notice ---------------------------------------------------
###
### This program is free software; you can redistribute it and/or modify
### it under the terms of the GNU General Public License as published by
### the Free Software Foundation; either version 2 of the License, or
### (at your option) any later version.
###
### This program is distributed in the hope that it will be useful,
### but WITHOUT ANY WARRANTY; without even the implied warranty of
### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
### GNU General Public License for more details.
###
### You should have received a copy of the GNU General Public License
### along with this program; if not, write to the Free Software Foundation,
### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

m4_divert(50)m4_dnl
###--------------------------------------------------------------------------
### ICMP filtering.

clearchain check-icmp

## Ping needs inspecting on a host-by-host basis.
for type in echo-request echo-reply; do
  run iptables -A check-icmp -p icmp --icmp-type $type -j RETURN
  run ip6tables -A check-icmp -p icmpv6 --icmpv6-type $type -j RETURN
done

m4_divert(58)m4_dnl
## Other ICMP is basically benign, we claim.
run ip46tables -A check-icmp -j ACCEPT

## Done.
for i in $inchains; do
  run iptables -A $i -p icmp -j check-icmp
  run ip6tables -A $i -p icmpv6 -j check-icmp
done

m4_divert(-1)
###----- That's all, folks --------------------------------------------------