#!/bin/sh
#============================================================================
# Default Xen network start/stop script.
# Xend calls a network script when it starts.
# The script name to use is defined in /etc/xen/xend-config.sxp
# in the network-script field.
#
# This script creates a bridge (default xenbr${vifnum}), adds a device
# (default eth${vifnum}) to it, copies the IP addresses from the device
# to the bridge and adjusts the routes accordingly.
#
# If all goes well, this should ensure that networking stays up.
# However, some configurations are upset by this, especially
# NFS roots. If the bridged setup does not meet your needs,
# configure a different script, for example using routing instead.
#
# Usage:
#
# network-bridge (start|stop|status) {VAR=VAL}*
#
# Vars:
#
# vifnum     Virtual device number to use (default 0). Numbers >=8
#            require the netback driver to have nloopbacks set to a
#            higher value than its default of 8.
# bridge     The bridge to use (default xenbr${vifnum}).
# netdev     The interface to add to the bridge (default eth${vifnum}).
# antispoof  Whether to use iptables to prevent spoofing (default no).
#
# Internal Vars:
# pdev="p${netdev}"
# vdev="veth${vifnum}"
# vif0="vif0.${vifnum}"
#
# start:
# Creates the bridge
# Copies the IP and MAC addresses from netdev to vdev
# Renames netdev to be pdev 
# Renames vdev to be netdev 
# Enslaves pdev, vdev to bridge
#
# stop:
# Removes netdev from the bridge
# Transfers addresses, routes from netdev to pdev
# Renames netdev to vdev
# Renames pdev to netdev 
# Deletes bridge
#
# status:
# Print addresses, interfaces, routes
#
#============================================================================
#
# 2007-07-31 - Ron Terry
#  - bridge is now created correctly when using bonded interfaces
#

dir=$(dirname "$0")
. "$dir/xen-script-common.sh"
. "$dir/xen-network-common.sh"

findCommand "$@"
evalVariables "$@"

vifnum=${vifnum:-$(ip route list | awk '/^default / { print $NF }' | sed 's/^[^0-9]*//')}
vifnum=${vifnum:-0}
bridge=${bridge:-xenbr${vifnum}}

#if [ -e /etc/sysconfig/network/ifcfg-bond* ]
#then
#  netdev=${netdev:-bond${vifnum}}
#else
  netdev=${netdev:-eth${vifnum}}
#fi
antispoof=${antispoof:-no}

pdev="p${netdev}"
vdev="veth${vifnum}"
vif0="vif0.${vifnum}"

# Usage: transfer_addrs src dst
# Copy all IP addresses (including aliases) from device $src to device $dst.
transfer_addrs () {
    local src=$1
    local dst=$2
    # Don't bother if $dst already has IP addresses.
    if ip addr show dev ${dst} | egrep -q '^ *inet ' ; then
        return
    fi
    # Address lines start with 'inet' and have the device in them.
    # Replace 'inet' with 'ip addr add' and change the device name $src
    # to 'dev $src'.
    ip addr show dev ${src} | egrep '^ *inet ' | sed -e "
s/inet/ip addr add/
s@\([0-9]\+\.[0-9]\+\.[0-9]\+\.[0-9]\+/[0-9]\+\)@\1@
s/${src}/dev ${dst}/
" | sh -e
    # Remove automatic routes on destination device
    ip route list | sed -ne "
/dev ${dst}\( \|$\)/ {
  s/^/ip route del /
  p
}" | sh -e
}

# Usage: transfer_routes src dst
# Get all IP routes to device $src, delete them, and
# add the same routes to device $dst.
# The original routes have to be deleted, otherwise adding them
# for $dst fails (duplicate routes).
transfer_routes () {
    local src=$1
    local dst=$2
    # List all routes and grep the ones with $src in.
    # Stick 'ip route del' on the front to delete.
    # Change $src to $dst and use 'ip route add' to add.
    ip route list | sed -ne "
/dev ${src}\( \|$\)/ {
  h
  s/^/ip route del /
  P
  g
  s/${src}/${dst}/
  s/^/ip route add /
  P
  d
}" | sh -e
}


##
# link_exists interface
#
# Returns 0 if the interface named exists (whether up or down), 1 otherwise.
#
link_exists()
{
    if ip link show "$1" >/dev/null 2>/dev/null
    then
        return 0
    else
        return 1
    fi
}

# Set the default forwarding policy for $dev to drop.
# Allow forwarding to the bridge.
antispoofing () {
    iptables -P FORWARD DROP
    iptables -F FORWARD
    iptables -A FORWARD -m physdev --physdev-in ${pdev} -j ACCEPT
    iptables -A FORWARD -m physdev --physdev-in ${vif0} -j ACCEPT
}

# Find the netdev that is associated with the bridge by matching MAC addresses.
find_bridged_netdev () {
    local bridge=$1

    bmac=`ip link show ${bridge} | grep 'link\/ether' | sed -e 's/.*ether \(..:..:..:..:..:..\).*/\1/'`
    for i in `ls /sys/class/net/${bridge}/brif` ; do
	mac=`ip link show ${i} | grep 'link\/ether' | sed -e 's/.*ether \(..:..:..:..:..:..\).*/\1/'`
	if [ "${bmac}" = "${mac}" ] && [ ! "${bridge}" = "${i}" ] ; then
	    netdev=${i}
	    return 0
	fi
    done
    return 1
}

# Usage: show_status dev bridge
# Print ifconfig and routes.
show_status () {
    local dev=$1
    local bridge=$2
    
    echo '============================================================'
    ip addr show ${dev}
    ip addr show ${bridge}
    echo ' '
    brctl show ${bridge}
    echo ' '
    ip route list
    echo ' '
    route -n
    echo '============================================================'
}

op_start () {
    if [ "${bridge}" = "null" ] ; then
	return
    fi

    if ! link_exists "$vdev"; then
        if link_exists "$pdev"; then
            # The device is already up.
            return
        else
            echo "
Link $vdev is missing.
This may be because you have reached the limit of the number of interfaces
that the loopback driver supports.  If the loopback driver is a module, you
may raise this limit by passing it as a parameter (nloopbacks=<N>); if the
driver is compiled statically into the kernel, then you may set the parameter
using loopback.nloopbacks=<N> on the domain 0 kernel command line.
" >&2
            exit 1
        fi
    fi

    create_bridge ${bridge}

    preiftransfer
    . /etc/sysconfig/network/ifcfg-${hwddev}
    if [ ! "$BONDING_MASTER" = yes ] && link_exists "$vdev"; then
    #############################################################
    #      Configure bridge for non-bonded interfaces
    #############################################################

	mac=`ip link show ${netdev} | grep 'link\/ether' | sed -e 's/.*ether \(..:..:..:..:..:..\).*/\1/'`
	ifup ${netdev}  # To ensure there is an IP to transfer
	transfer_addrs ${netdev} ${vdev}
	ifdown ${netdev}
	ip link set ${netdev} name ${pdev}
	ip link set ${vdev} name ${netdev}

	setup_bridge_port ${pdev}
	setup_bridge_port ${vif0}
	ip link set ${netdev} addr ${mac} arp on

	ip link set ${bridge} up
	add_to_bridge  ${bridge} ${vif0}
	add_to_bridge2 ${bridge} ${pdev}
	ip link set ${netdev} up
	ifup ${hwddev}
    elif [ "$BONDING_MASTER" = yes ]; then
    #############################################################
    #      Configure bridge for bonded interfaces
    #############################################################

        # set variables
        local netdev_ip=`ip addr show dev ${netdev}|egrep '^ *inet '|sed "s/^ *inet //"|cut -d " " -f 1`
        local bondslave_list=`ifstatus ${netdev}|egrep -i "slave interface"|cut -d ":" -f 2|sed "s/ //"`
	local mac=`ip link show ${netdev} | grep 'link\/ether' | sed -e 's/.*ether \(..:..:..:..:..:..\).*/\1/'`
	local BRIDGE_NUM=${netdev##${netdev%%[0-9]*}}
	pdev=eth${BRIDGE_NUM}
	new_netdev=eth${BRIDGE_NUM}

        #echo "netdev = ${netdev}"
        #echo "netdev_ip = ${netdev_ip}"
        #echo "bondslave_list = $bondslave_list"
        #echo "mac = $mac"
        #echo "BRIDGE_NUM = $BRIDGE_NUM"
        #echo "new_netdev = $new_netdev"
        #echo "vdev = $vdev"
        #echo "pdev = $pdev"
        #echo "bridge = $bridge"
        #echo "vif0 = $vif0"
        #read

	#ip link set ${bridge} arp on

        #####  We must reconfigure the bonded interface first  #####

        #echo "bring bonded interface ${netdev} down";read
        ip link set ${netdev} down

        #echo "clean up ${netdev} (arp off, change MAC, flush IP address, etc.)";read
        ip link set ${netdev} arp off
        ip link set ${netdev} multicast off
        ip link set ${netdev} addr fe:ff:ff:ff:ff:ff
        ip addr flush ${netdev}

        #echo "rename the bondslave interfaces";read
        for DEV in $bondslave_list
        do
          #echo "renaming ${DEV} to p${DEV}";read
          ip link set ${DEV} name p${DEV}
        done

        #echo "bring ${netdev} back up with new bondslave names";read
        ifup ${netdev}
        #ip link set ${netdev} arp on
        #ip link set ${netdev} multicast on

        #####  Here is where we attach the bridge ports to the bridge  #####

        #echo "bring up the bridge ${bridge}";read
	ip link set ${bridge} up

        #echo "add ${netdev} to bridge as a bridge port";read
	add_to_bridge2 ${bridge} ${netdev}

        #echo "add ${vif0} to bridge as a ${bridge} port";read
	add_to_bridge ${bridge} ${vif0}

        #echo "clean up ${vif0} (arp off, change MAC, flush IP address, etc.)";read
	setup_bridge_port ${vif0}

        #echo "bring ${vif0} up";read
	ip link set ${vif0} up
        
        #####  Next we must configure the new interface for Dom0  #####

        #echo "make sure the ${vdev} interface is down";read
        ip link set ${vdev} down

        #echo "rename ${vdev} to ${pdev}";read
	ip link set ${vdev} name ${pdev}

        #echo "transfer ${netdev}'s MAC address to ${pdev} and turn arp on";read
	ip link set ${pdev} addr ${mac} arp on

        #echo "bring new ${pdev} interface up";read
        ip link set ${pdev} up

        #echo "transfer ${netdev}'s IP address to ${pdev}";read
        ip addr add dev ${pdev} ${netdev_ip} brd +

        #echo "transfer ${netdev}'s routes to ${pdev}";read
	transfer_routes ${netdev} ${pdev}

    else
	# old style without ${vdev}
	transfer_addrs  ${netdev} ${bridge}
	transfer_routes ${netdev} ${bridge}
    fi

    if [ ${antispoof} = 'yes' ] ; then
	antispoofing
    fi
}

op_stop () {
    if [ "${bridge}" = "null" ]; then
	return
    fi
    if ! link_exists "$bridge"; then
	return
    fi

    preiftransfer
    . /etc/sysconfig/network/ifcfg-${hwddev}
    if [ ! "$BONDING_MASTER" = yes ] && link_exists "$pdev"; then
    #############################################################
    #      Remove bridge for non-bonded interfaces
    #############################################################

	ip link set dev ${vif0} down
	mac=`ip link show ${netdev} | grep 'link\/ether' | sed -e 's/.*ether \(..:..:..:..:..:..\).*/\1/'`
	transfer_addrs ${netdev} ${pdev}
	ifdown ${netdev}
	ip link set ${netdev} down arp off
	ip link set ${netdev} addr fe:ff:ff:ff:ff:ff
	ip link set ${pdev} down
	ip addr flush ${netdev}
	ip link set ${pdev} addr ${mac} arp on

	brctl delif ${bridge} ${pdev}
	brctl delif ${bridge} ${vif0}
	ip link set ${bridge} down

	ip link set ${netdev} name ${vdev}
	ip link set ${pdev} name ${netdev}
	ifup ${netdev}

    elif [ "$BONDING_MASTER" = yes ]; then
    #############################################################
    #      Remove bridge for bonded interfaces
    #############################################################

	local BRIDGE_NUM=${netdev##${netdev%%[0-9]*}}
	local pdev=eth${BRIDGE_NUM}
	local new_netdev=eth${BRIDGE_NUM}
        local netdev_ip=`ip addr show dev ${pdev}|egrep '^ *inet '|sed "s/^ *inet //"|cut -d " " -f 1`
        local bondslave_list=`ifstatus ${netdev}|egrep -i "slave interface"|cut -d ":" -f 2|sed "s/ //"`
	local mac=`ip link show ${pdev} | grep 'link\/ether' | sed -e 's/.*ether \(..:..:..:..:..:..\).*/\1/'`

        #echo "netdev = ${netdev}"
        #echo "netdev_ip = ${netdev_ip}"
        #echo "bondslave_list = $bondslave_list"
        #echo "mac = $mac"
        #echo "BRIDGE_NUM = $BRIDGE_NUM"
        #echo "new_netdev = $new_netdev"
        #echo "vdev = $vdev"
        #echo "pdev = $pdev"
        #echo "bridge = $bridge"
        #echo "vif0 = $vif0"
        #read

        #####  First we reset the virtual interface ${pdev}  #####

        #echo "bring ${pdev} down";read
	ifdown ${pdev}
	ip link set ${pdev} down arp off
	ip link set ${pdev} addr fe:ff:ff:ff:ff:ff
	ip addr flush ${pdev}

        #####  Then we reset the bridge port ${vif0}  #####

        #echo "bring ${vif0} down";read
	ip link set dev ${vif0} down

        #####  Then we reset the bonded interface ${netdev}  #####

        #echo "bring the bonded interface ${netdev} down";read
        ip link set ${netdev} down
	#ip link set ${netdev} down arp off
	#ip link set ${netdev} addr fe:ff:ff:ff:ff:ff
	ip addr flush ${netdev}

        #####  Then we remove the bridge port interfaces from the bridge  #####

        #echo "removing ${netdev} from ${bridge}";read
	brctl delif ${bridge} ${netdev}

        #echo "removing ${vif0} from ${bridge}";read
	brctl delif ${bridge} ${vif0}

        #####  Then we rename the  virtual interface back to its original name  #####

        #echo "rename ${pdev} to ${vdev}";read
	ip link set ${pdev} name ${vdev}

        #####  Then we reset the renamed bond slave interface ${pdev}

        for DEV in $bondslave_list
        do
          local OLD_DEV=`echo ${DEV}|sed "s/p//"`
          #echo "bring the bond slave ${DEV} down";read
	  ip link set ${DEV} down

          #echo "rename the bond slave ${DEV} to ${OLD_DEV}";read
          ip link set ${DEV} name ${OLD_DEV}

        done

        #####  And then we restart the bonded interface  #####

        #echo "bring bonded interface back up";read
	ifup ${netdev}

        #####  Then we bring the bridge ${bridge} down  #####
 
        #echo "bring the bridge ${bridge} down";read
	ip link set ${bridge} down

    else
	if [ ${netdev} = ${bridge} ]; then
	    find_bridged_netdev ${bridge}
	fi
	ip link set dev ${vif0} down
	transfer_routes ${bridge} ${netdev}
	ip link set ${bridge} down
    fi

    #####  Finally we delete the bridge  #####

    brctl delbr ${bridge}
}

op_start_hostonly () {
    if [ "${bridge}" = "null" ] ; then
	return
    fi
    if link_exists "${bridge}"; then
	return
    fi

    create_bridge ${bridge}
    setup_bridge_port ${vif0}
    add_to_bridge  ${bridge} ${vif0}
}

op_stop_hostonly () {
    if [ "${bridge}" = "null" ]; then
	return
    fi
    if ! link_exists "$bridge"; then
	return
    fi

    brctl delbr ${bridge}
}


# adds $dev to $bridge but waits for $dev to be in running state first
add_to_bridge2() {
    local bridge=$1
    local dev=$2
    local maxtries=10

    echo -n "Waiting for ${dev} to negotiate link."
    ip link set ${dev} up
    for i in `seq ${maxtries}` ; do
	if ifconfig ${dev} | grep -q RUNNING ; then
	    break
	else
	    echo -n '.'
	    sleep 1
	fi
    done

    if [ ${i} -eq ${maxtries} ] ; then echo '(link isnt in running state)' ; fi

    add_to_bridge ${bridge} ${dev}
}

case "$command" in
    start)
	if test "$netdev" = "none"; then
		op_start_hostonly
	else
		op_start
	fi
	;;
    
    stop)
	if test "$netdev" = "none"; then
		op_stop_hostonly
	else
		op_stop
	fi
	;;

    status)
	show_status ${netdev} ${bridge}
	;;

    *)
	echo "Unknown command: $command" >&2
	echo 'Valid commands are: start, stop, status' >&2
	exit 1
esac