busybox/examples/udhcp/sample.renew
Denys Vlasenko 9c192e7f94 examples: make udhcpc script handle /32 netmasks
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-04-06 00:53:43 +02:00

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#!/bin/sh
# Sample udhcpc renew script
RESOLV_CONF="/etc/udhcpc/resolv.conf"
[ -n "$broadcast" ] && BROADCAST="broadcast $broadcast"
[ -n "$subnet" ] && NETMASK="netmask $subnet"
/sbin/ifconfig $interface $ip $BROADCAST $NETMASK
if [ -n "$router" ]
then
echo "deleting routers"
while /sbin/route del default gw 0.0.0.0 dev $interface
do :
done
metric=0
for i in $router
do
if [ "$subnet" = "255.255.255.255" ]; then
# special case for /32 subnets:
# /32 instructs kernel to always use routing for all outgoing packets
# (they can never be sent to local subnet - there is no local subnet for /32).
# Used in datacenters, avoids the need for private ip-addresses between two hops.
/sbin/ip route add $i dev $interface
fi
/sbin/route add default gw $i dev $interface metric $((metric++))
done
fi
# Only replace resolv.conf if we have at least one DNS server
if [ -n "$dns" ]
then
echo -n > $RESOLV_CONF
[ -n "$domain" ] && echo domain $domain >> $RESOLV_CONF
for i in $dns
do
echo adding dns $i
echo nameserver $i >> $RESOLV_CONF
done
fi