#!/bin/bash
# Needs bash for printf -v VARNAME
# -----------------------------------------------------------------------------
#
# Copyright (c) 2011 - OpenSLX GmbH
#
# This program is free software distributed under the GPL version 2.
# See http://openslx.org/COPYING
#
# If you have any feedback please consult http://openslx.org/feedback and
# send your suggestions, praise, or complaints to feedback@openslx.org
#
# General information about OpenSLX can be found at http://openslx.org/
# -----------------------------------------------------------------------------
#
#                               Mini-Linux Toolkit
#
# -----------------------------------------------------------------------------

. /opt/openslx/config

RESOLV_CONF="/opt/openslx/resolv.conf"
THIS_RESOLV="/run/network/${interface}.resolv"

rebuild_resolv_conf () {
	# Don't do anything if the active resolv.conf is not ours
	# Also this will not run resolvconf update.d... No idea if we should still do so...
	[ -L "/etc/resolv.conf" ] || return 0
	[ "x$(readlink "/etc/resolv.conf")" == "x${RESOLV_CONF}" ] || return 0
	# Maybe make this smarter some time, if anyone is using clients that are on multiple networks at once etc...
	# This is a little braindead but should work most of the time
	sort -u /run/network/*.resolv > "$RESOLV_CONF" 2> /dev/null

	# add support for resolv.conf update scripts // see man(8) resolvconf
	if [ -d /etc/resolvconf/update.d ]; then
		for s in $(ls -1 /etc/resolvconf/update.d/*.sh); do
			$s
		done
	fi
}

escape_search() {
	echo "$@" | sed -e 's/[]\/()$*.^|[]/\\&/g'
}

escape_replace() {
	echo "$@" | sed -e 's/[\/&]/\\&/g'
}

check_env() {
	if [ -z "$ip" -o -z "$subnet" -o -z "$interface" ]; then
		echo "$1 event with missing data" >&2
		echo "ip = '$ip'" >&2
		echo "subnet = '$subnet'" >&2
		echo "interface = '$interface'" >&2
		exit 1
	fi
}

if [ ! -d /run ]; then
	echo -n "Waiting for /run." >&2
	while [ ! -d /run ]; do
		echo -n "." >&2
		usleep 500000
	done
	echo "" >&2
fi

case "$1" in
	bound|renew)
		check_env "$1"
		mkdir -p "/run/dhcpc"
		# Set address on interface
		ip addr add "$ip/$(ipcalc -s -p $ip $subnet|sed s/.*=//)" dev "$interface"
		# Set default route, if given
		if [ -n "$router" ]; then
			ip route add default via "$router"
		fi
		
		# get domain, hostname and thus fqdn from DNS
		dns_fqdn=$(/opt/openslx/bin/busybox timeout -t 3 rdns "$ip")
		dns_short="${dns_fqdn%%.*}"
		# check if it is fqdn
		if [ "$dns_fqdn" == "$dns_short" ]; then
			unset dns_fqdn dns_short
		fi

		# Update resolver configuration file
		CONF=""
		if [ -n "$domain" ]; then
			printf -v CONF "${CONF}domain $domain\n"
		elif [ -n "$dns_fqdn" ]; then
			domain="${dns_fqdn#*.}"
			printf -v CONF "${CONF}domain $domain\n"
			
		elif [ -n "$SLX_NET_DOMAIN" ]; then
			domain="$SLX_NET_DOMAIN"
			printf -v CONF "${CONF}domain $domain\n"
		fi
		if [ -n "$search" ]; then
			printf -v CONF "${CONF}search $search\n"
		elif [ -n "$SLX_SEARCH_DOMAIN" ]; then
			printf -v CONF "${CONF}search $SLX_SEARCH_DOMAIN\n"
		elif [ -n "$SLX_NET_DOMAIN" ]; then
			printf -v CONF "${CONF}search $SLX_NET_DOMAIN\n"
		fi
		for i in $dns; do
			echo "$0: Adding DNS $i"
			printf -v CONF "${CONF}nameserver $i\n"
		done
		
		if [ -x "/sbin/resolvconf" ] && [ -L "/etc/resolv.conf" ] && [ -d "/etc/resolvconf/update.d" ]; then
			# Automatic handling :-)
			resolvconf --create-runtime-directories
			resolvconf --enable-updates
			echo -n "$CONF" | resolvconf -a "${interface}.udhcpc"
		else
			# Manual handling required :-(
			echo -n "$CONF" > "$THIS_RESOLV"
			rebuild_resolv_conf
		fi

		
		# Things that should only happen for the main interface that was used for booting
		if [ "$interface" == "br0" ]; then
			# Update IP
			sed -i "s/^\(SLX_PXE_CLIENT_IP=\).*$/\1'$ip'/" /opt/openslx/config
			
			# Only if network is not ready yet
			if [ ! -e "/run/network/network-ready" ]; then
				# Update hostname
				if [ -z "$dns_fqdn" -a -n "$domain" -a -n "$hostname" ]; then
					# fallback to what the dhcp told us
					dns_fqdn="${hostname}.${domain}"
				fi
				if [ -z "$dns_fqdn" ]; then
					# only if there is no /etc/hostname, we fall back (far back, that is)
					[ ! -s "/etc/hostname" ] && dns_fqdn="slx-client"
				fi
				# finally, if dns_fqdn was set to anything, apply it
				if [ -n "$dns_fqdn" ]; then
					dns_short="${dns_fqdn%%.*}"
					echo "$dns_short" > "/proc/sys/kernel/hostname"
					echo "$dns_short" > "/etc/hostname"
					if grep '^SLX_HOSTNAME=' /opt/openslx/config 2>/dev/null; then
						sed -i "s/^\(SLX_HOSTNAME=\).*$/\1'$dns_short'/" /opt/openslx/config
					else
						echo "# Config written by openslx-dhcp-script (1)" >> /opt/openslx/config
						echo "SLX_HOSTNAME='$dns_short'" >> /opt/openslx/config
					fi
				fi

				# if domain is given from dhcp, save it to openslx config for later use in VMs
				if [ -n "$domain" ]; then
						# check if SLX_NET_DOMAIN is in the config at all
					if grep '^SLX_NET_DOMAIN=' /opt/openslx/config 2>/dev/null; then
						sed -i "s/^\(SLX_NET_DOMAIN=\).*$/\1'$domain'/" /opt/openslx/config
					else
						# not set, add it
						echo "SLX_NET_DOMAIN='$domain'" >> /opt/openslx/config
					fi
				fi
				# Update /etc/issue for proper spacing
				/opt/openslx/scripts/openslx-create_issue
				touch "/run/network/network-ready"
				# Mark network target as reached
				systemctl start network.target &
			fi # end "network not ready yet"
		fi # end "br0 only"
		
		# Hostname in /etc/hosts
		touch "/etc/hosts"
		hostlist=""
		[ -n "$dns_fqdn" ] && hostlist="$dns_fqdn"
		[ -n "$hostname" -a -n "$domain" -a "x${hostname}.${domain}" != "x$dns_fqdn" ] && hostlist="$hostlist ${hostname}.${domain}"
		if [ -n "$hostlist" ]; then
			for host in $hostlist; do
				host_short="${host%%.*}"
				[ "x$host_short" = "x$host" ] && host_short=""
				sed -i -r "s/\s$(escape_search "$host")(\s|$)/ /g" /etc/hosts
				[ -n "$host_short" ] && sed -i -r "s/\s$(escape_search "$host_short")(\s|$)/ /g" /etc/hosts
				if grep -q -E "^$ip\s" /etc/hosts; then
					sed -i "s/^$(escape_search "$ip")\s.*/$(escape_replace "$ip $host $host_short")/g" /etc/hosts
				else
					echo "$ip $host $host_short" >> /etc/hosts
				fi
			done
		fi
		# Get rid of orphaned lines in /etc/hosts
		sed -i -r '/^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+\s*$/d' /etc/hosts
		
		# "dns ready" target
		if [ -n "$dns" ] && [ ! -e "/run/network/dns-ready" ]; then
			touch "/run/network/dns-ready"
			# Write to openslx-config
			echo "# Config written by openslx-dhcp-script (2)" >> /opt/openslx/config
			echo "SLX_DNS='$dns'" >> /opt/openslx/config
			systemctl start network-dns.target &
		fi
		# "default route exists" target
		if [ -n "$router" ] && [ ! -e "/run/network/gateway-ready" ]; then
			touch "/run/network/gateway-ready"
			# Write to openslx-config
			echo "# Config written by openslx-dhcp-script (3)" >> /opt/openslx/config
			echo "SLX_DNS='$dns'" >> /opt/openslx/config
			systemctl start network-gateway.target &
		fi
		
			# Port redirection for printing happens in printergui module (iptables-helper rule)
			####iptables -A INPUT -i br0 -p tcp --dport 515 -j DROP
			####iptables -A INPUT -i br0 -p tcp --dport 5515 -j DROP
			####iptables -t nat -A PREROUTING -s 192.168.0.0/16 -p tcp --dport 515 -j REDIRECT --to-port 5515
	;;
	
	deconfig)
		check_env "$1"
		if [ $(grep -c "nfs=" /proc/cmdline) == 0 ]; then
			echo 1 > "/proc/sys/net/ipv4/conf/$interface/promote_secondaries"
			clientip=${ip%%:*}
			ip addr del "$clientip/$(ipcalc -s -p $clientip $subnet|sed s/.*=//)" dev "$interface"
			sed -i "/^$(escape_search "$ip")(\s|$)/d" /etc/hosts
		else
			echo "NFS is active, not removing old ip adress. warning: lease may expire after a while."
		fi
		
		if [ -x /sbin/resolvconf ] && [ -L /etc/resolv.conf ] && [ -d /etc/resolvconf/update.d ]; then
			# Automatic handling :-)
			resolvconf -d "${interface}.udhcpc"
		else
			# Manual handling required :-(
			rm -f -- "$THIS_RESOLV"
			rebuild_resolv_conf
		fi
	;;
	
	leasefail)
		echo "$0: Lease failed: $message" >&2
		
	;;
	
	nak)
		echo "$0: Received a NAK: $message" >&2
		
	;;
	
	*)
		echo "$0: Unknown udhcpc command: $1" >&2
		exit 1
		
	;;
esac

exit 0