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#!/bin/bash
# dhclient-script for Linux. Dan Halbert, March, 1997.
# Updated for Linux 2.[12] by Brian J. Murrell, January 1999.
# Modified for Debian. Matt Zimmerman and Eloy Paris, December 2003
# Modified to remove useless tests for antiquated kernel versions that
# this doesn't even work with anyway, and introduces a dependency on /usr
# being mounted, which causes cosmetic errors on hosts that NFS mount /usr
# Andrew Pollock, February 2005
# Modified to work on point-to-point links. Andrew Pollock, June 2005
# Modified to support passing the parameters called with to the hooks. Andrew Pollock, November 2005
# The alias handling in here probably still sucks. -mdz
make_resolv_conf() {
if [ "$new_domain_name" -o "$new_domain_name_servers" ]; then
# Find out whether we are going to mount / rw
exec 9>&0 </etc/fstab
rootmode=rw
while read dev mnt type opts dump pass junk; do
[ "$mnt" != / ] && continue
case "$opts" in
ro|ro,*|*,ro|*,ro,*)
rootmode=ro
;;
esac
done
exec 0>&9 9>&-
# Wait for /etc/resolv.conf to become writable
if [ "$rootmode" = "rw" ]; then
while [ ! -w /etc ]; do
sleep 0.1
done
fi
fi
if [ "$new_domain_name" -o "$new_domain_name_servers" ]; then
local new_resolv_conf=/etc/resolv.conf.dhclient-new
rm -f $new_resolv_conf
if [ "$new_domain_name" ]; then
echo domain ${new_domain_name%% *} >>$new_resolv_conf
fi
if [ "$new_domain_search" ]; then
#new_domain_search="${new_domain_search% }"
if [ "$new_domain_name" ]; then
domain_in_search_list=""
for domain in "$new_domain_search"; do
if [ "$domain" = "$new_domain_name" ]; then
domain_in_search="Yes"
fi
done
if [ ! "$domain_in_search" ]; then
new_domain_search="$new_domain_name $new_domain_search"
fi
fi
echo "search ${new_domain_search}" >> $new_resolv_conf
elif [ "$new_domain_name" ]; then
echo "search ${new_domain_name}" >> $new_resolv_conf
fi
if [ "$new_domain_name_servers" ]; then
for nameserver in $new_domain_name_servers; do
echo nameserver $nameserver >>$new_resolv_conf
done
else # keep 'old' nameservers
sed -n /^\w*[Nn][Aa][Mm][Ee][Ss][Ee][Rr][Vv][Ee][Rr]/p /etc/resolv.conf >>$new_resolv_conf
fi
chown --reference=/etc/resolv.conf $new_resolv_conf
chmod --reference=/etc/resolv.conf $new_resolv_conf
mv -f $new_resolv_conf /etc/resolv.conf
fi
}
run_hook() {
local script="$1"
local exit_status
shift # discard the first argument, then the rest are the script's
if [ -f $script ]; then
. $script "$@"
fi
if [ -n "$exit_status" ] && [ "$exit_status" -ne 0 ]; then
logger -p daemon.err "$script returned non-zero exit status $exit_status"
save_exit_status=$exit_status
fi
return $exit_status
}
run_hookdir() {
local dir="$1"
local exit_status
shift # See run_hook
if [ -d "$dir" ]; then
for script in $(run-parts --list $dir); do
run_hook $script "$@" || true
exit_status=$?
done
fi
return $exit_status
}
# Must be used on exit. Invokes the local dhcp client exit hooks, if any.
exit_with_hooks() {
exit_status=$1
# Source the documented exit-hook script, if it exists
if ! run_hook /etc/dhcp/dhclient-exit-hooks "$@"; then
exit_status=$?
fi
# Now run scripts in the Debian-specific directory.
if ! run_hookdir /etc/dhcp/dhclient-exit-hooks.d "$@"; then
exit_status=$?
fi
exit $exit_status
}
if [ -n "$new_broadcast_address" ]; then
new_broadcast_arg="broadcast $new_broadcast_address"
fi
if [ -n "$old_broadcast_address" ]; then
old_broadcast_arg="broadcast $old_broadcast_address"
fi
if [ -n "$new_subnet_mask" ]; then
new_subnet_arg="netmask $new_subnet_mask"
fi
if [ -n "$old_subnet_mask" ]; then
old_subnet_arg="netmask $old_subnet_mask"
fi
if [ -n "$alias_subnet_mask" ]; then
alias_subnet_arg="netmask $alias_subnet_mask"
fi
# The 576 MTU is only used for X.25 and dialup connections
# where the admin wants low latency. Such a low MTU can cause
# problems with UDP traffic, among other things. As such,
# disallow MTUs from 576 and below by default, so that broken
# MTUs are ignored, but higher stuff is allowed (1492, 1500, etc).
if [ -n "$new_interface_mtu" ] && [ $new_interface_mtu -gt 576 ]; then
mtu_arg="mtu $new_interface_mtu"
fi
if [ -n "$IF_METRIC" ]; then
metric_arg="metric $IF_METRIC" # interfaces(5), "metric" option
fi
# The action starts here
# Invoke the local dhcp client enter hooks, if they exist.
run_hook /etc/dhcp/dhclient-enter-hooks
run_hookdir /etc/dhcp/dhclient-enter-hooks.d
# Execute the operation
case "$reason" in
MEDIUM|ARPCHECK|ARPSEND)
# Do nothing
;;
PREINIT)
# The DHCP client is requesting that an interface be
# configured as required in order to send packets prior to
# receiving an actual address. - dhclient-script(8)
if [ -n "$alias_ip_address" ]; then
# Bring down alias interface. Its routes will disappear too.
ifconfig $interface:0- inet 0
fi
ifconfig $interface inet 0 up
;;
BOUND|RENEW|REBIND|REBOOT)
if [ -n "$old_host_name" -a ! -s /etc/hostname ]; then
hostname "$new_host_name"
fi
if [ -n "$old_ip_address" -a -n "$alias_ip_address" -a \
"$alias_ip_address" != "$old_ip_address" ]; then
# Possible new alias. Remove old alias.
ifconfig $interface:0- inet 0
fi
if [ -n "$old_ip_address" -a \
"$old_ip_address" != "$new_ip_address" ]; then
# IP address changed. Bringing down the interface will delete all routes,
# and clear the ARP cache.
ifconfig $interface inet 0
fi
if [ -z "$old_ip_address" -o "$old_ip_address" != "$new_ip_address" -o \
"$reason" = "BOUND" -o "$reason" = "REBOOT" ]; then
ifconfig $interface inet $new_ip_address $new_subnet_arg \
$new_broadcast_arg $mtu_arg
# point to point
if [ "$new_subnet_mask" == "255.255.255.255" ]; then
for router in $new_routers; do
route add -host $router dev $interface
done
fi
for router in $new_routers; do
route add default dev $interface gw $router $metric_arg
done
fi
if [ "$new_ip_address" != "$alias_ip_address" -a -n "$alias_ip_address" ];
then
ifconfig $interface:0- inet 0
ifconfig $interface:0 inet $alias_ip_address $alias_subnet_arg
route add -host $alias_ip_address $interface:0
fi
make_resolv_conf
;;
EXPIRE|FAIL|RELEASE|STOP)
if [ -n "$alias_ip_address" ]; then
# Turn off alias interface.
ifconfig $interface:0- inet 0
fi
if [ -n "$old_ip_address" ]; then
# Shut down interface, which will delete routes and clear arp cache.
ifconfig $interface inet 0
fi
if [ -n "$alias_ip_address" ]; then
ifconfig $interface:0 inet $alias_ip_address $alias_subnet_arg
route add -host $alias_ip_address $interface:0
fi
;;
TIMEOUT)
if [ -n "$alias_ip_address" ]; then
ifconfig $interface:0- inet 0
fi
ifconfig $interface inet $new_ip_address $new_subnet_arg \
$new_broadcast_arg $mtu_arg
set -- $new_routers
first_router="$1"
if [ -z "$first_router" ] || ping -q -c 1 $first_router; then
if [ "$new_ip_address" != "$alias_ip_address" -a \
-n "$alias_ip_address" ]; then
ifconfig $interface:0 inet $alias_ip_address $alias_subnet_arg
route add -host $alias_ip_address dev $interface:0
fi
for router in $new_routers; do
route add default dev $interface gw $router $metric_arg
done
make_resolv_conf
else
# Changed from 'ifconfig $interface inet 0 down' - see Debian bug #144666
ifconfig $interface inet 0
exit_with_hooks 2 "$@"
fi
;;
esac
exit_with_hooks 0
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