#!/bin/sh

# 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
		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 $new_resolv_conf
		chmod $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/dhcp3/dhclient-exit-hooks "$@"; then
		exit_status=$?
	fi

	# Now run scripts in the Debian-specific directory.
	if ! run_hookdir /etc/dhcp3/dhclient-exit-hooks.d "$@"; then
		exit_status=$?
	fi

	exit $exit_status
}

set_hostname() {
	local current_hostname=$(hostname)
	if [ -z "$current_hostname" -o "$current_hostname" = "(none)" ]; then
		hostname "$new_host_name"
	fi
}

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 $alias_subnet_mask"
fi
if [ -n "$new_interface_mtu" ] && [ $new_interface_mtu -ge 575 ]; 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/dhcp3/dhclient-enter-hooks
run_hookdir /etc/dhcp3/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-  0
		fi
		ifconfig $interface  0 up

		# We need to give the kernel some time to get the interface up.
		sleep 1
		;;
	BOUND|RENEW|REBIND|REBOOT)

		set_hostname

		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-  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  0

		fi

		if [ -z "$old_ip_address" -o "$old_ip_address" != "$new_ip_address" -o \
			"$reason" = "BOUND" -o "$reason" = "REBOOT" ]; then

			ifconfig $interface  $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-  0
			ifconfig $interface:0  $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-  0
		fi

		if [ -n "$old_ip_address" ]; then
			# Shut down interface, which will delete routes and clear arp cache.
			ifconfig $interface  0
		fi

		if [ -n "$alias_ip_address" ]; then
			ifconfig $interface:0  $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-  0
		fi

		ifconfig $interface  $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  $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  0 down' - see Debian bug #144666
			ifconfig $interface  0
			exit_with_hooks 2 "$@"
		fi

		;;
esac

exit_with_hooks 0
