#!/bin/bash
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.

INT_BRIDGE="br-int"
HYBRID_PLUG="'ovs_hybrid_plug': True"

OPERATION=$1
PORT=$2
VETH=$3
CONTAINER_UUID=$4
MAC_ADDRESS=$5

ovs_bind_port() {
    echo "plugging veth $VETH (Neutron port $PORT)..."
    ovs-vsctl -- --may-exist add-port $INT_BRIDGE $VETH -- \
        set interface $VETH external_ids:attached-mac=$MAC_ADDRESS \
        external_ids:iface-id=$PORT external_ids:vm-uuid=$CONTAINER_UUID \
        external_ids:iface-status=active external_ids:owner=kuryr
}

ovs_unbind_port() {
    echo "unplugging port $PORT..."
    MYPORT=`ovs-vsctl --data=bare --no-heading --columns=name \
        find interface external_ids:iface-id=$PORT \
        external_ids:owner=kuryr`
    if [ -z "$MYPORT" ]; then
        echo >&2 "Failed to find port $PORT."
        exit 1
    fi
    ovs-vsctl del-port $INT_BRIDGE $MYPORT
}

ovs_hybrid_bind_port() {
    echo "... plugging veth $VETH (Neutron port $PORT) ..."
    # create a linux bridge
    br_name="qbr"${PORT:0:11}
    ip link add name $br_name type bridge
    # Using brctl allows containerized usage not to need privileged mode
    # as sysfs is mounted read-only when running with just CAP_NET_ADMIN
    brctl setfd $br_name 0
    brctl stp $br_name off

    # connect the veth outside to linux bridge
    ip link set $VETH up
    ip link set dev $VETH master $br_name
    # create a veth pair to connect linux bridge and the integration bridge
    veth_lb="qvb"${PORT:0:11}
    veth_ovs="qvo"${PORT:0:11}
    ip link add $veth_lb type veth peer name $veth_ovs

    # connect one end to the linux bridge
    ip link set dev $veth_lb master $br_name
    ip link set $br_name up

    # connect one end to the ovs integration bridge
    ovs-vsctl add-port $INT_BRIDGE $veth_ovs -- \
        set interface $veth_ovs external_ids:attached-mac=$MAC_ADDRESS \
        external_ids:iface-id=$PORT external_ids:vm-id=$CONTAINER_UUID \
        external_ids:iface-status=active external_ids:owner=kuryr

    ip link set $veth_lb up
    ip link set $veth_ovs up
}

ovs_hybrid_unbind_port() {
    echo "unplugging port $PORT ..."
    br_name="qbr"${PORT:0:11}
    veth_lb="qvb"${PORT:0:11}
    veth_ovs="qvo"${PORT:0:11}

    ip link set dev $veth_lb nomaster
    ovs-vsctl del-port $veth_ovs
    ip link delete $veth_lb type veth

    ip link set $br_name down
    ip link delete $br_name type bridge
}


case $OPERATION in
    "bind")
        shift
        if [ "${7/$HYBRID_PLUG}" = "$7" ]
        then
            ovs_bind_port
        else
            ovs_hybrid_bind_port
        fi
        exit 0
        ;;
    "unbind")
        shift
        if [ "${5/$HYBRID_PLUG}" = "$5" ]
        then
            ovs_unbind_port
        else
            ovs_hybrid_unbind_port
        fi
        exit 0
        ;;
    *)
        echo >&2 "$0: Invalid command $OPERATION."
        exit 1
        ;;
esac