| #!/bin/sh |
| |
| # Contributed by Darren Hoo <darren.hoo@gmail.com> |
| |
| # If you use dnsmasq as DHCP server on a router, you may have |
| # met with attackers trying ARP Poison Routing (APR) on your |
| # local area network. This script will setup a 'permanent' entry |
| # in the router's ARP table upon each DHCP transaction so as to |
| # make the attacker's efforts less successful. |
| |
| # Usage: |
| # edit /etc/dnsmasq.conf and specify the path of this script |
| # to dhcp-script, for example: |
| # dhcp-script=/usr/sbin/static-arp |
| |
| # if $1 is add or old, update the static arp table entry. |
| # if $1 is del, then delete the entry from the table |
| # if $1 is init which is called by dnsmasq at startup, it's ignored |
| |
| ARP=/usr/sbin/arp |
| |
| # Arguments. |
| # $1 is action (add, del, old) |
| # $2 is MAC |
| # $3 is address |
| # $4 is hostname (optional, may be unset) |
| |
| if [ ${1} = del ] ; then |
| ${ARP} -d $3 |
| fi |
| |
| if [ ${1} = old ] || [ ${1} = add ] ; then |
| ${ARP} -s $3 $2 |
| fi |
| |
