#!/bin/sh

[ "$VERBOSITY" = 1 ] && set -x

IFSTATE=/var/run/ifstate

add_master()
{
	# Return if $BOND_MASTER is already a bonding interface.
	[ -f "/sys/class/net/$BOND_MASTER/bonding/slaves" ] && return

	# If the bonding module is not yet loaded, load it.
	if [ ! -r /sys/class/net/bonding_masters ]; then
		modprobe -q bonding
	fi

	# Create the master interface.
	if ! grep -sq "\\<$BOND_MASTER\\>" /sys/class/net/bonding_masters; then
		echo "+$BOND_MASTER" > /sys/class/net/bonding_masters
	fi
}

sysfs()
{
	# Called with :
	# $1 = value to write. Won't write if $1 is empty.
	# $2 = basename of the file in bonding/ to write to.
	if [ "$1" ] ; then
		echo "$1" > "/sys/class/net/$BOND_MASTER/bonding/$2"
		return $?
	fi
	return 0
}

sysfs_add()
{
	# Called with :
	# $1 = values to write.
	# $2 = target filename.
	for value in $1; do
		# Do not add $1 to $2 if already present.
		if ! grep -sq "\\<$value\\>" /sys/class/net/$BOND_MASTER/bonding/$2
		then
		    sysfs "+$value" "$2"
		fi 
	done
}

ifup_once()
{
	local v=
	[ "$VERBOSITY" = 1 ] && v=-v
	if [ "$1" != "$IFACE" ] && ! grep -q "^$1=" $IFSTATE && ifup -n "$1" >/dev/null 2>&1; then
		ifup $v $1
	fi
}

enslave_slaves()
{
	case "$BOND_SLAVES" in
		none)
			BOND_SLAVES=""
			;;
		all)
			BOND_SLAVES=`sed -ne 's/ *\(eth[^:]*\):.*/\1/p' /proc/net/dev`
			AUTOIF="yes"
			;;
	esac

	for slave in $BOND_SLAVES ; do
		if ( [ "$AUTOIF" ] && grep -q "^$slave=" $IFSTATE ) ; then
			echo "Not enslaving interface $slave since it is already configured"
		else
			# Ensure $slave is down.
			ip link set "$slave" down 2>/dev/null
			if ! sysfs_add "$slave" slaves 2>/dev/null ; then
				echo "Failed to enslave $slave to $BOND_MASTER. Is $BOND_MASTER ready and a bonding interface ?" >&2
			else
				# Bring up slave if it is defined in interfaces 
				# This is usefull to bring up slaves that need extra setup.
				ifup_once $slave
			fi
		fi
	done
}

setup_master()
{
	sysfs "$IF_BOND_MODE" mode
	sysfs "$IF_BOND_MIIMON" miimon
	sysfs "$IF_BOND_USE_CARRIER" use_carrier
	sysfs "$IF_BOND_UPDELAY" updelay
	sysfs "$IF_BOND_DOWNDELAY" downdelay
	sysfs "$IF_BOND_ARP_INTERVAL" arp_interval
	sysfs "$IF_BOND_ARP_VALIDATE" arp_validate
	sysfs "$IF_BOND_FAIL_OVER_MAC" fail_over_mac
	sysfs "$IF_BOND_XMIT_HASH_POLICY" xmit_hash_policy
	sysfs "$IF_BOND_LACP_RATE" lacp_rate
	sysfs_add "$IF_BOND_ARP_IP_TARGET" arp_ip_target
}

setup_slaves()
{
	# The first slave in bond-primary found in current slaves becomes the primary.
	# If no slave in bond-primary is found, then primary does not change.
	for slave in $IF_BOND_PRIMARY ; do
		if grep -sq "\\<$slave\\>" "/sys/class/net/$BOND_MASTER/bonding/slaves" ; then
			sysfs "$slave" primary
			break
		fi
	done

	if [ "$IF_BOND_ACTIVE_SLAVE" ] ; then
		# Need to force interface up before. Bonding will refuse to activate a down interface.
		ip link set "$IF_BOND_ACTIVE_SLAVE" up
		sysfs "$IF_BOND_ACTIVE_SLAVE" active_slave
	fi
}

# Are there anything to do ?

# Option slaves deprecated, replaced by bond-slaves, but still supported for backward compatibility.
IF_BOND_SLAVES=${IF_BOND_MEMBERS:-${IF_BOND_SLAVES:-$IF_SLAVES}}

if [ "$IF_BOND_MASTER" ] ; then
	BOND_MASTER="$IF_BOND_MASTER"
	BOND_SLAVES="$IFACE"
	if ! [ -e /sys/class/net/$IFACE/master ]; then
		ifup_once $BOND_MASTER
	fi
else
	if [ "$IF_BOND_SLAVES$IF_BOND_MODE" ]; then
		BOND_MASTER="$IFACE"
		BOND_SLAVES="$IF_BOND_SLAVES"
	fi
fi

# Exit if nothing to do...
[ -z "$BOND_MASTER$BOND_SLAVES" ] && exit

add_master
setup_master
enslave_slaves
setup_slaves