#!/bin/sh

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

[ "$ADDRFAM" = meta ] && exit 0

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

	ip link add dev "$IFACE" type bond
}

sysfs_change_down()
{
	# Called with :
	# $1 = basename of the file in bonding/ to write to.
	# $2 = value to write. Won't write if $2 is empty.
	if [ -n "$2" ] ; then
		# If the value we plan to write is different from the current one...
		if ! grep -sq "\\<$2\\>" "/sys/class/net/$BOND_MASTER/bonding/$1" ; then
			# ...and the master is up...
			if ip link show "$BOND_MASTER" | grep -sq '[<,]UP[,>]' ; then
				# ...bring the master down.
				ip link set dev "$BOND_MASTER" down
			fi
		fi
		sysfs "$1" "$2"
	fi
}

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

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

# early_setup_master is the place where we do master setup that need to be done before enslavement.
early_setup_master()
{
	# Warning: the order in which we write into the sysfs files is important.
	# Double check in drivers/net/bonding/bond_sysfs.c in the Linux kernel source tree
	# before changing anything here.

	# fail_over_mac must be set before enslavement of any slaves.
	sysfs fail_over_mac "$IF_BOND_FAIL_OVER_MAC"
}

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

	[ "$VERBOSITY" = 1 ] && v=-v
	for slave in $BOND_SLAVES ; do
		export IFENSLAVE_ENV_NAME="IFUPDOWN_$slave"
		IFUPDOWN_IFACE="$(printenv "$IFENSLAVE_ENV_NAME")"
		unset IFENSLAVE_ENV_NAME
		if ( ( ifquery --state "$slave" >/dev/null 2>&1 ) && ( ifquery "$slave" | grep -q bond-master ) ) || [ -n "$IFUPDOWN_IFACE" ] ; then
			# Skipping interface that's already up or being configured and has bonding configuration
			continue
		else
			# Ensure $slave is down.
			ip link set "$slave" down 2>/dev/null
			if ! sysfs_add slaves "$slave" 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 the target of an allow-bondX stanza.
				# This is useful to bring up slaves that need extra setup.
				ifup $v --allow "$BOND_MASTER" "$slave"
			fi
		fi
	done
}

setup_master()
{
	# Warning: the order in which we write into the sysfs files is important.
	# Double check in drivers/net/bonding/bond_sysfs.c in the Linux kernel source tree
	# before changing anything here.

	# use_carrier can be set anytime.
	sysfs use_carrier "$IF_BOND_USE_CARRIER"
	# num_grat_arp can be set anytime.
	sysfs num_grat_arp "$IF_BOND_NUM_GRAT_ARP"
	# num_unsol_na can be set anytime.
	sysfs num_unsol_na "$IF_BOND_NUM_UNSOL_NA"

	# arp_ip_target must be set before arp_interval.
	sysfs_add arp_ip_target "$IF_BOND_ARP_IP_TARGET"
	sysfs arp_interval "$IF_BOND_ARP_INTERVAL"

	# miimon must be set before updelay and downdelay.
	sysfs miimon "$IF_BOND_MIIMON"
	sysfs downdelay "$IF_BOND_DOWNDELAY"
	sysfs updelay "$IF_BOND_UPDELAY"

	# Changing ad_select requires $BOND_MASTER to be down.
	sysfs_change_down ad_select "$IF_BOND_AD_SELECT"

	# Changing mode requires $BOND_MASTER to be down.
	# Mode should be set after miimon or arp_interval, to avoid a warning in syslog.
	sysfs_change_down mode "$IF_BOND_MODE"

	# Requires $BOND_MASTER to be down and mode to be configured
	sysfs_change_down xmit_hash_policy "$IF_BOND_XMIT_HASH_POLICY"
	sysfs_change_down tlb_dynamic_lb "$IF_BOND_TLB_DYNAMIC_LB"

	# packets_per_slave allowed for mode balance-rr only.
	sysfs packets_per_slave "$IF_BOND_PACKETS_PER_SLAVE"

	# arp_validate must be after mode (because mode must be active-backup).
	sysfs arp_validate "$IF_BOND_ARP_VALIDATE"

	# lacp_rate must be set after mode (because mode must be 802.3ad).
	# Changing lacp_rate requires $BOND_MASTER to be down.
	sysfs_change_down lacp_rate "$IF_BOND_LACP_RATE"

	# queue_id must be set after enslavement.
	for iface_queue_id in $IF_BOND_QUEUE_ID ; do
		sysfs iface_queue_id "$iface_queue_id"
	done

	# active_slave must be set after mode and after enslavement.
	# The slave must be up and the underlying link must be up too.
	# FIXME: We should have a way to write an empty string to active_slave, to set the active_slave to none.
	if [ -n "$IF_BOND_ACTIVE_SLAVE" ] ; then
		if [ "$IF_BOND_ACTIVE_SLAVE" = "none" ] ; then
			sysfs active_slave ""
		else
			# Need to force interface up before. Bonding will refuse to activate a down interface.
			if ifquery -l "$IF_BOND_ACTIVE_SLAVE" >/dev/null 2>&1 ; then
				ifup "$IF_BOND_ACTIVE_SLAVE"
			else
				ip link set "$IF_BOND_ACTIVE_SLAVE" up
			fi
			sysfs active_slave "$IF_BOND_ACTIVE_SLAVE"
		fi
	fi
}

setup_primary() {
	# primary must be set after mode (because only supported in some modes) and after enslavement.
	# The first slave in bond-primary found in current slaves becomes the primary.
	# If no slave in bond-primary is found, then the primary does not change.
	for slave in $IF_BOND_PRIMARY ; do
		slaves="/sys/class/net/$BOND_MASTER/bonding/slaves"
		if grep -sq "\\<$slave\\>" "$slaves" ; then
			sysfs primary "$slave"
			break
		fi
	done

	# primary_reselect should be set after mode (it is only supported in some modes), after enslavement
	# and after primary. This is currently (2.6.35-rc1) not enforced by the bonding driver, but it is
	# probably safer to do it in that order.
	sysfs primary_reselect "$IF_BOND_PRIMARY_RESELECT"
}

setup_master_device() {
	add_master
	early_setup_master
	setup_master
	enslave_slaves
	setup_primary
}

setup_slave_device() {
	# Require the bond master to have an iface stanza
	if ! ifquery -l "$IF_BOND_MASTER" >/dev/null 2>&1 ; then
		echo "No iface stanza found for master $IF_BOND_MASTER" >&2
		exit 1
	fi

	# Ensure the master is up or being configured
	export IFENSLAVE_ENV_NAME="IFUPDOWN_$IF_BOND_MASTER"
	IFUPDOWN_IF_BOND_MASTER="$(printenv "$IFENSLAVE_ENV_NAME")"
	unset IFENSLAVE_ENV_NAME
	if [ -z "$IFUPDOWN_IF_BOND_MASTER" ] ; then
		ifquery --state "$IF_BOND_MASTER" >/dev/null 2>&1 || ifup "$IF_BOND_MASTER"
	fi

	# Enslave it to the master
	ip link set "$1" down 2>/dev/null
	if ! sysfs_add slaves "$1" 2>/dev/null ; then
		echo "Failed to enslave $1 to $BOND_MASTER." >&2
	fi

	setup_primary
}

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

if [ -n "$IF_BOND_MASTER" ] ; then
	# FIXME: use function arguments instead of this variable
	BOND_MASTER="$IF_BOND_MASTER"
	setup_slave_device "$IFACE"
elif [ -n "$IF_BOND_SLAVES" ] || [ -n "$IF_BOND_MODE" ] ; then
	# FIXME: use function arguments instead of these variables
	BOND_MASTER="$IFACE"
	BOND_SLAVES="$IF_BOND_SLAVES"
	setup_master_device "$IFACE"
fi

exit 0