#!/bin/bash -e

# ip netns add bar
# export CNI_IFNAME='foo' CNI_CONTAINERID='bar' CNI_COMMAND='ADD'
# echo '{ "deviceID": "0000:07:02.0" }' | /opt/cni/bin/vfioveth

CNI_CONF=$(</dev/stdin)

get_peer_name() {
	echo "$1-vdev"
}

get_mac_with_vfpci() {
	local pf=$(readlink /sys/devices/pci*/*/$1/physfn | awk '{print substr($1,4)}')
	local pfName=$(ls /sys/devices/pci*/*/$pf/net/ | head -1)
	local idx=$(ls -l /sys/devices/pci*/*/$pf | awk -v vf=$1 'substr($11,4)==vf {print substr($9,7)}')
	local mac=$(ip link show dev $pfName | awk -v idx="$idx" '$1=="vf" && $2==idx {print substr($4,1,17)}')
	echo $mac
}

add_pair_ns() {
	vfpci=$(echo $CNI_CONF | jq -r '.deviceID')
	mac=$(get_mac_with_vfpci $vfpci)
	peer=$(get_peer_name $CNI_IFNAME)

	ip netns exec $CNI_CONTAINERID ip link add $CNI_IFNAME type veth peer name $peer
	ip netns exec $CNI_CONTAINERID ip link set $CNI_IFNAME addr $mac up
	ip netns exec $CNI_CONTAINERID ip link set $peer up
}

delete_pair_ns() {
	ip netns exec $CNI_CONTAINERID ip link del $CNI_IFNAME
}

case $CNI_COMMAND in
ADD)
	add_pair_ns
	;;
DEL)
	delete_pair_ns
	;;
*)
	echo "CNI_COMMAND=[ADD|DEL] only supported"
	exit 1
	;;
esac