#!/bin/sh

PROGRAM=$(basename $0)

die() {
	echo $* >&2
	exit 1
}

usage() {
	echo "Usage: $PROGRAM [-d] <master-if> <slave-if> ...

Options:
 -d	Detach slaves

"
	exit 1
}

		
OPER='+'
while getopts "dh" opt ; do
	case $opt in
		d) OPER="-";;
		h) usage;;
	esac
done

shift $(( $OPTIND - 1 ))

[ $# -lt 2 ] && usage

bondif=$1
shift

#check if $bondif is a bonding master
unset found
for i in $(cat /sys/class/net/bonding_masters) ; do
	[ "$i" = "$bondif" ] &&	found=1
done
[ "$found" != 1 ] && die "$bondif is not a bonding master. Aborting"

while [ $# -gt 0 ] ; do
	if [ "$OPER" = "+" ] && [ -d /sys/class/net/$1/master ] ; then
		echo "Interface '$1' is already a slave. Skipping" >&2
	elif [ -d /sys/class/net/$1 ]; then
		# flush ip adresses and set link down before adding
		if [ "$OPER" = '+' ]; then
			ip addr flush dev $1 >/dev/null 2>&1
			ip link set dev $1 down #linux will bring link up
		fi
		( echo "${OPER}${1}" > /sys/class/net/$bondif/bonding/slaves ) >/dev/null \
			|| echo "Slave '$1' failed. Skipping" >&2
	else
		echo "Slave '$1' is not a network interface. Skipping" >&2
	fi
	shift
done