#!/bin/bash
#written in bash for fewest prerequisites
function get_def_interface {
	#gethostbyname on `hostname` would be helpful, but since we
	#are in bash, the best alternative is to use ping to get at it
	#don't want to grep in /etc/hosts or presume DNS
	#we are, however, presuming ipv4 for the moment
	retval=$(ping -c 1 `hostname`|head -n 1|cut -d\( -f 2|cut -d\) -f 1)
	if [ -z "$retval" -o "127.0.0.1" = "$retval" ]; then #ok, that didn't pan out, now we grab the first address that looks sane
		retval=`ifconfig|grep inet" " |grep -v addr:127.0.0.1|grep -v 'addr:169.254'|head -n 1|cut -d: -f 2|cut -d' ' -f 1`
	fi
	if [ -z "$retval" ]; then 
		echo "ERROR: Unable to reasonably guess the 'default' interface" >&2
		exit 1
	fi
	iface=`ifconfig|grep -v inet6|egrep '(Link|inet)'|grep -B1 'addr:'$retval |head -n 1|awk '{print $1}'`
	if [ -z "$iface" ]; then
		echo "ERROR: Unable to reasonably guess the default interface" >&2
		exit 1
	fi
	if brctl show | grep ^$iface >& /dev/null; then #
		OIFS=$IFS
		IFS=$'\n'
		INMATCH=0
		for brline in $(brctl show); do
			if [ $(expr match "$brline" $iface) == $(expr length $iface) ]; then
				INMATCH=1
			elif [ $(expr match "$brline" "	") != 1 ]; then
				INMATCH=0
			fi
			if [ "$INMATCH" == 1 ];  then
				if ! ethtool -i `echo $brline|awk '{print $NF}'`|grep "driver: tun" >& /dev/null; then
					iface=`echo $brline|awk '{print $NF}'`
					echo "$iface"
					IFS=$OFIS
					return
				fi
			fi
		done
	else 
		echo "$iface"
	fi
}
if [ "storageprereq" = "$1"  ]; then
	MOUNTURI="$2"
	DIRNAME=`echo $MOUNTURI|sed -e 's!nfs://!nfs_!'`
	MOUNTPATH=`echo $DIRNAME|sed -e 's!nfs_!!'|sed -e 's!/!:/!'`
	if mount|grep $MOUNTPATH > /dev/null; then
		exit 0;
	fi
	mkdir -p /var/lib/xcat/vmnt/$DIRNAME
	mount $MOUNTPATH /var/lib/xcat/vmnt/$DIRNAME
elif [ "bridgeprereq" = "$1" ]; then
	NETDESC="$2"
	if [ -z "$NETDESC" ]; then
		echo "Incorrect usage"
		exit 1
	fi
	if echo "$NETDESC"|grep ':'> /dev/null; then
		PORTS=`echo "$NETDESC"|cut -d: -f 1`
		BNAME=`echo "$NETDESC"|cut -d: -f 2`
	else 
		BNAME=$NETDESC
	fi
	if brctl showstp "$BNAME" > /dev/null; then
		echo "$BNAME"
		exit 0
	fi
	#Still here, that means we must build a bridge
	if [ -z "$PORTS" ]; then #No ports specified, default to whatever looks up
		PORTS=$(get_def_interface)
	fi
	if [ -z "$PORTS" ]; then #This has been checked many times before in theory, check again just in case
		exit 1
	fi
	#For now, we only support bridge name==network name.  This precludes
	#the config of the same vlan number on multiple fabrics, but
	#will cover that flexibility later if demanded (with 4k vlan ids, 
	#I think it would be unwise to reuse them as it could confuse anyway)
	if echo "$PORTS"|grep '&'; then #we have bonding... fun to be had
	#To be slack, going to just support one bond for now..
		modprobe bonding miimon=100 mode=4
		PORTS=`echo $PORTS |sed -e 's/&/ /'`
		ip link set bond0 up
		for p in $PORTS; do
			#TODO: we are only going to manage the default
			#route for now
			saveroutes=`ip route | grep default| grep "dev $p"|grep via|sed -e 's/dev .*//'`
			#TODO: support inet6+inet and aliases, probably messing with IFS to do so
			saveip=`ip addr show dev $p scope global|grep inet|sed -e 's/inet.//'|sed -e 's/[^ ]*$//'`
			if [ ! -z "$saveip" ]; then
				ip addr add dev bond0 $saveip
			fi
			ifenslave bond0 $p
			if [ ! -z "$saveroutes" ]; then
				ip route add $saveroutes
			fi
		done
		PORTS=bond0
	fi
	if echo "$BNAME"|egrep '^vl(an)?[0123456789]' > /dev/null; then 
		TNAME=${BNAME##vl}
		TNAME=${TNAME##an}
		#We have a vlan... more fun
		modprobe 8021q
		vconfig add $PORTS $TNAME
		vconfig set_flag $PORTS.$TNAME 2 1 #Turn on GVRP where supported
		ip link set $PORTS.$TNAME up
		PORTS=$PORTS.$TNAME
	fi
	#Now, $PORTS is 'the' physical device to participate in a bridge
	#TODO: we are only going to manage the default
	#route for now
	brctl addbr $BNAME
	brctl setfd $BNAME 0 #fast forwarding
	ip link set $BNAME up
	saveroutes=`ip route | grep default| grep "dev $PORTS"|grep via|sed -e 's/dev .*//'`
	#TODO: support inet6+inet and aliases, probably messing with IFS to do so
	saveip=`ip addr show dev $PORTS scope global|grep inet|sed -e 's/inet.//'|sed -e 's/[^ ]*$//'`
	if [ ! -z "$saveip" ]; then
		ip addr add dev $BNAME $saveip
	fi
	brctl addif $BNAME $PORTS
	if [ ! -z "$saveip" ]; then
		ip addr del dev $PORTS $saveip
	fi
	if [ ! -z "$saveroutes" ]; then
		ip route add $saveroutes
	fi
fi #END bridge config.