ubuntu-buildroot/package/dhcp/dhclient-script

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#!/bin/sh
# dhclient-script from OpenWRT project
# http://git.openwrt.org/?p=packages.git;a=blob;f=net/isc-dhcp/files/dhclient-script;h=4afebc0ad20ebac51c5baae5ed01c6713e3a0fd0;hb=HEAD
make_resolv_conf() {
if [ x"$new_domain_name_servers" != x ]; then
cat /dev/null > /etc/resolv.conf.dhclient
chmod 644 /etc/resolv.conf.dhclient
if [ x"$new_domain_search" != x ]; then
echo search $new_domain_search >> /etc/resolv.conf.dhclient
elif [ x"$new_domain_name" != x ]; then
# Note that the DHCP 'Domain Name Option' is really just a domain
# name, and that this practice of using the domain name option as
# a search path is both nonstandard and deprecated.
echo search $new_domain_name >> /etc/resolv.conf.dhclient
fi
for nameserver in $new_domain_name_servers; do
echo nameserver $nameserver >>/etc/resolv.conf.dhclient
done
elif [ "x${new_dhcp6_name_servers}" != x ] ; then
cat /dev/null > /etc/resolv.conf.dhclient6
chmod 644 /etc/resolv.conf.dhclient6
if [ "x${new_dhcp6_domain_search}" != x ] ; then
echo search ${new_dhcp6_domain_search} >> /etc/resolv.conf.dhclient6
fi
for nameserver in ${new_dhcp6_name_servers} ; do
echo nameserver ${nameserver} >> /etc/resolv.conf.dhclient6
done
fi
# if both v4 and v6 clients are running, concatenate results
cat /etc/resolv.conf.* > /etc/resolv.conf
}
# Must be used on exit. Invokes the local dhcp client exit hooks, if any.
exit_with_hooks() {
exit_status=$1
if [ -f /etc/dhclient-exit-hooks ]; then
. /etc/dhclient-exit-hooks
fi
# probably should do something with exit status of the local script
exit $exit_status
}
# Invoke the local dhcp client enter hooks, if they exist.
if [ -f /etc/dhclient-enter-hooks ]; then
exit_status=0
. /etc/dhclient-enter-hooks
# allow the local script to abort processing of this state
# local script must set exit_status variable to nonzero.
if [ $exit_status -ne 0 ]; then
exit $exit_status
fi
fi
###
### DHCPv4 Handlers
###
if [ x$new_broadcast_address != x ]; then
new_broadcast_arg="broadcast $new_broadcast_address"
fi
if [ x$new_subnet_mask != x ]; then
new_subnet_arg="netmask $new_subnet_mask"
fi
if [ x$alias_subnet_mask != x ]; then
alias_subnet_arg="netmask $alias_subnet_mask"
fi
if [ x$reason = xMEDIUM ]; then
# Linux doesn't do mediums (ok, ok, media).
exit_with_hooks 0
fi
if [ x$reason = xPREINIT ]; then
if [ x$alias_ip_address != x ]; then
# Bring down alias interface. Its routes will disappear too.
ifconfig $interface:0- 0.0.0.0
fi
ifconfig $interface 0.0.0.0 up
# We need to give the kernel some time to get the interface up.
sleep 1
exit_with_hooks 0
fi
if [ x$reason = xARPCHECK ] || [ x$reason = xARPSEND ]; then
exit_with_hooks 0
fi
if [ x$reason = xBOUND ] || [ x$reason = xRENEW ] || \
[ x$reason = xREBIND ] || [ x$reason = xREBOOT ]; then
current_hostname=`hostname`
if [ x$current_hostname = x ] || \
[ x$current_hostname = x$old_host_name ]; then
if [ x$current_hostname = x ] || \
[ x$new_host_name != x$old_host_name ]; then
hostname $new_host_name
fi
fi
if [ x$old_ip_address != x ] && [ x$alias_ip_address != x ] && \
[ x$alias_ip_address != x$old_ip_address ]; then
# Possible new alias. Remove old alias.
ifconfig $interface:0- 0.0.0.0
fi
if [ x$old_ip_address != x ] && [ x$old_ip_address != x$new_ip_address ]; then
# IP address changed. Bringing down the interface will delete all routes,
# and clear the ARP cache.
ifconfig $interface 0.0.0.0 down
fi
if [ x$old_ip_address = x ] || [ x$old_ip_address != x$new_ip_address ] || \
[ x$reason = xBOUND ] || [ x$reason = xREBOOT ]; then
ifconfig $interface $new_ip_address $new_subnet_arg \
$new_broadcast_arg
for router in $new_routers; do
if [ "x$new_subnet_mask" = "x255.255.255.255" ] ; then
route add -host $router dev $interface
fi
route add default gw $router
done
fi
if [ x$new_ip_address != x$alias_ip_address ] && [ x$alias_ip_address != x ];
then
ifconfig $interface:0- 0.0.0.0
ifconfig $interface:0 $alias_ip_address $alias_subnet_arg
route add -host $alias_ip_address $interface:0
fi
make_resolv_conf
exit_with_hooks 0
fi
if [ x$reason = xEXPIRE ] || [ x$reason = xFAIL ] || [ x$reason = xRELEASE ] \
|| [ x$reason = xSTOP ]; then
if [ x$alias_ip_address != x ]; then
# Turn off alias interface.
ifconfig $interface:0- 0.0.0.0
fi
if [ x$old_ip_address != x ]; then
# Shut down interface, which will delete routes and clear arp cache.
ifconfig $interface 0.0.0.0 down
fi
if [ x$alias_ip_address != x ]; then
ifconfig $interface:0 $alias_ip_address $alias_subnet_arg
route add -host $alias_ip_address $interface:0
fi
# remove v4 dns configuration for this interface
rm /etc/resolv.conf.dhclient
cat /etc/resolv.conf.* > /etc/resolv.conf
exit_with_hooks 0
fi
if [ x$reason = xTIMEOUT ]; then
if [ x$alias_ip_address != x ]; then
ifconfig $interface:0- 0.0.0.0
fi
ifconfig $interface $new_ip_address $new_subnet_arg \
$new_broadcast_arg
set $new_routers
if ping -q -c 1 $1; then
if [ x$new_ip_address != x$alias_ip_address ] && \
[ x$alias_ip_address != x ]; then
ifconfig $interface:0 $alias_ip_address $alias_subnet_arg
route add -host $alias_ip_address dev $interface:0
fi
for router in $new_routers; do
if [ "x$new_subnet_mask" = "x255.255.255.255" ] ; then
route add -host $router dev $interface
fi
route add default gw $router
done
make_resolv_conf
exit_with_hooks 0
fi
ifconfig $interface 0.0.0.0 down
exit_with_hooks 1
fi
###
### DHCPv6 Handlers
###
if [ x$reason = xPREINIT6 ]; then
# Ensure interface is up.
ifconfig ${interface} up
# Remove any stale addresses from aborted clients.
ip -f inet6 addr flush dev ${interface} scope global
exit_with_hooks 0
fi
if [ x${old_ip6_prefix} != x ] || [ x${new_ip6_prefix} != x ] ; then
echo Prefix ${reason} old=${old_ip6_prefix} new=${new_ip6_prefix}
exit_with_hooks 0
fi
if [ x$reason = xBOUND6 ]; then
if [ x${new_ip6_address} = x ] || [ x${new_ip6_prefixlen} = x ] ; then
exit_with_hooks 2;
fi
ifconfig ${interface} add ${new_ip6_address}/${new_ip6_prefixlen}
# Check for nameserver options.
make_resolv_conf
### <<
# Set up softwire tunnel
if [ x${new_dhcp6_softwire} != x ] ; then
/etc/init.d/dhclient stop
ifconfig ${interface} 0.0.0.0
ip -6 tunnel add tun0 mode ipip6 \
remote ${new_dhcp6_softwire} \
local ${new_ip6_address} \
dev ${interface} encaplimit none
ip link set tun0 up
ip route add default dev tun0
fi
### >>
exit_with_hooks 0
fi
if [ x$reason = xRENEW6 ] || [ x$reason = xREBIND6 ]; then
if [ x${new_ip6_address} = x ] || [ x${new_ip6_prefixlen} = x ] ; then
exit_with_hooks 2;
fi
ifconfig ${interface} add ${new_ip6_address}/${new_ip6_prefixlen}
# Make sure nothing has moved around on us.
# Nameservers/domains/etc.
if [ "x${new_dhcp6_name_servers}" != "x${old_dhcp6_name_servers}" ] ||
[ "x${new_dhcp6_domain_search}" != "x${old_dhcp6_domain_search}" ] ; then
make_resolv_conf
fi
exit_with_hooks 0
fi
if [ x$reason = xDEPREF6 ]; then
if [ x${new_ip6_address} = x ] ; then
exit_with_hooks 2;
fi
# Busybox ifconfig has no way to communicate this to the kernel, so ignore it
exit_with_hooks 0
fi
if [ x$reason = xEXPIRE6 -o x$reason = xRELEASE6 -o x$reason = xSTOP6 ]; then
if [ x${old_ip6_address} = x ] || [ x${old_ip6_prefixlen} = x ] ; then
exit_with_hooks 2;
fi
ifconfig ${interface} del ${old_ip6_address}/${old_ip6_prefixlen}
# remove v6 dns configuration for this interface
rm /etc/resolv.conf.dhclient6
cat /etc/resolv.conf.* > /etc/resolv.conf
### <<
# Tear down softwire tunnel
if [ x${old_dhcp6_softwire} != x ] ; then
ip link set tun0 down
ip tunnel del tun0
fi
### >>
exit_with_hooks 0
fi
exit_with_hooks 0