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Diffstat (limited to 'contrib/static-arp/static-arp')
| -rw-r--r-- | contrib/static-arp/static-arp | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/contrib/static-arp/static-arp b/contrib/static-arp/static-arp new file mode 100644 index 0000000..82115b7 --- /dev/null +++ b/contrib/static-arp/static-arp @@ -0,0 +1,35 @@ +#!/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 + |