Author: Fabrice MARIE <fabrice@netfilter.org>
Status: It Works For Me.

Adds the possibility to send icmp-unreachable messages
from a fake source IP address. The original destination of the packet will be
used as the source of the icmp-unreach.

To make it so that the icmp-unreach seems to come from the destination host :
# iptables -A FORWARD -p tcp -d 202.156.58.0/24 --dport domain -j REJECT --fake-source
# iptables --list
Chain FORWARD (policy ACCEPT)
target     prot opt source               destination
REJECT     tcp  --  anywhere             202.156.58.0/24    tcp dpt:domain reject-with icmp-port-unreachable source-faked

***** WARNING ***** This patch also patch the userspace directory which means that you
                    you have to recompile and reinstall the iptables package after that.