buildroot/package/dhcp/dhclient-script
Gustavo Zacarias 1cd15cb15a dhcp: update dhclient-script
The previous no-op dhclient-script is useless and in fact can lead
users to believe things will work.
dhclient-script is supposed to, among many other things, bring the
interface up for dhclient to pump an address, set the interface
address, set resolv.conf appropiately and set the default gateway.
It's a complex script since it has to deal with a lot of details so
let's just use the best fit which is the OpenWRT one since it uses the
"legacy" tools (ifconfig, route, ...) which can be easily provided by
busybox and/or net-tools.
There are newer and more feature-complete versions around but they
require full iproute2 ip and wouldn't fit as well with the busybox-only
approach.

License: likely GPLv2+
Source:
http://git.openwrt.org/?p=packages.git;a=blob;f=net/isc-dhcp/files/dhclient-script;h=4afebc0ad20ebac51c5baae5ed01c6713e3a0fd0;hb=HEAD

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
2014-11-28 12:34:55 +01:00

285 lines
7.9 KiB
Bash
Executable File

#!/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