vxlan-utils.sh

#!/bin/bash

if [ -z "$IF_VXLAN_VNI" ]; then
	exit 0;
fi

function prep_args {
	add_args=()
	if [ -n "$IF_VXLAN_PORT" ]; then
		add_args+=("dstport" "$IF_VXLAN_PORT")
	fi
	if [ -n "$IF_VXLAN_REMOTE" ]; then
		add_args+=("remote" "$IF_VXLAN_REMOTE")
	fi
	if [ -n "$IF_VXLAN_GROUP" ]; then
		add_args+=("group" "$IF_VXLAN_GROUP")
	fi
	if [ -n "$IF_VXLAN_TTL" ]; then
		add_args+=("ttl" "$IF_VXLAN_TTL")
	fi
	if [ -n "$IF_VXLAN_LOCAL" ]; then
		add_args+=("local" "$IF_VXLAN_LOCAL")
	fi
}

function parse_fdb {
	python3 - "$IF_VXLAN_FDB" "$IF_VXLAN_LOCAL" "$IFACE" << 'EOF'
import sys,socket,yaml,ipaddress
inet = 0
fdb = yaml.safe_load(open(sys.argv[1], mode='r'))
try:
  localIP = ipaddress.ip_address(sys.argv[2])
  if isinstance(localIP, ipaddress.IPv4Address):
    inet = 4
  else:
    inet = 6
except ValueError:
  localIP = None
for group in fdb:
  try:
    try:
      group_addr = ipaddress.ip_address(group['addr'])
      if group_addr == ipaddress.ip_address("0.0.0.0") or group_addr == ipaddress.ip_address("::"):
        group_mac = "00:00:00:00:00:00"
      elif group_addr.is_multicast:
        if isinstance(group_addr, ipaddress.IPv4Address):
          group_mac = "01:00:5e:{:02x}:{:02x}:{:02x}".format(group_addr.packed[1] & ~0x80, *group_addr.packed[2:4])
        else:
          group_mac = "33:33:{:02x}:{:02x}:{:02x}:{:02x}".format(*group_addr.packed[12:16])
      else:
        raise Exception("Expect Multicast Address, but got {}".format(group_addr))
    except ValueError:
      group_mac = group['addr']
 
    for dest in group['dest']:
      try:
        dest_addr = ipaddress.ip_address(dest)
        if inet == 4:
          if not isinstance(dest_addr, ipaddress.IPv4Address):
            raise Exception("Expect IPv4 Address, but got {}".format(dest))
        elif inet == 6:
          if not isinstance(dest_addr, ipaddress.IPv6Address):
            raise Exception("Expect IPv6 Address, but got {}".format(dest))
        else:
          if isinstance(dest_addr, ipaddress.IPv4Address):
            inet = 4
          else:
            inet = 6
        if not dest_addr == localIP:
          print("fdb append {} dev {} dst {}".format(group_mac, sys.argv[3], dest_addr))
      except Exception as e:
        print(e, file=sys.stderr) 
  except Exception as e:
    print(e, file=sys.stderr)
EOF
}


case "$PHASE" in 
	pre-up)
		prep_args
		exec ip link add name "$IFACE" type vxlan id "$IF_VXLAN_VNI" "${add_args[@]}"
		;;
	post-up)
		if [ -r "$IF_VXLAN_FDB" ]; then
			echo "Loading FDB for device $IFACE" >&2
			parse_fdb | bridge -batch -
			bridge fdb show dev "$IFACE" >&2
		fi
		;;
	post-down)
		exec ip link del "$IFACE"
esac