#!/bin/sh

# Copyright (C) 2008,2009 Citrix Systems, Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published
# by the Free Software Foundation; version 2.1 only. with the special
# exception on linking described in file LICENSE.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Lesser General Public License for more details.

# CA-23900: Warning: when VIFs are added to windows guests with PV drivers the backend vif device is registered,
# unregistered and then registered again. This causes the udev event to fire twice and this script runs twice.
# Since the first invocation of the script races with the device unregistration, spurious errors are possible
# which will be logged but are safe to ignore since the second script invocation should complete the operation.
# Note that each script invocation is run synchronously from udev and so the scripts don't race with each other.

# Keep other-config/ keys in sync with device.ml:vif_udev_keys

BRCTL="/usr/sbin/brctl"
IP="/sbin/ip"

vsctl="/usr/bin/ovs-vsctl"

# XAPI before build 29381 (approximately) did not provide some of the
# data in XenStore that we rely on.
. /etc/xensource-inventory
if test "$PRODUCT_VERSION" = "5.5.0" || test "${BUILD_NUMBER%[a-z]}" -le 26131
then
    xs550=true
else
    xs550=false
fi

handle_promiscuous()
{
    local arg=$(xenstore-read "${PRIVATE}/other-config/promiscuous" 2>/dev/null)
    if [ $? -eq 0 -a -n "${arg}" ] ; then
        case $NETWORK_MODE in
            bridge)
                case "${arg}" in 
                    true|on) echo 1 > /sys/class/net/${dev}/brport/promisc ;;
                    *) echo 0 > /sys/class/net/${dev}/brport/promisc ;;
                esac
                ;;
            openvswitch)
                logger -t script-vif "${dev}: Promiscuous ports are not supported via Open vSwitch."
                ;;
        esac
    fi
}

handle_ethtool()
{
    local opt=$1
    local arg=$(xenstore-read "${PRIVATE}/other-config/ethtool-${opt}" 2>/dev/null)
    if [ $? -eq 0 -a -n "${arg}" ] ; then
        case "${arg}" in
            true|on)   /sbin/ethtool -K "${dev}" "${opt}" on ;;
            false|off) /sbin/ethtool -K "${dev}" "${opt}" off ;;
            *) logger -t scripts-vif "Unknown ethtool argument ${opt}=${arg} on ${dev}/${VIFUUID}" ;;
        esac
    fi
}

handle_mtu()
{
    local mtu=$(xenstore-read "${PRIVATE}/MTU" 2>/dev/null)
    if [ $? -eq 0 -a -n "${mtu}" ]; then
        logger -t scripts-vif "Setting ${dev} MTU ${mtu}"
        ${IP} link set "${dev}" mtu ${mtu} || logger -t scripts-vif "Failed to ip link set ${dev} mtu ${mtu}. Error code $?"
    fi
}

set_vif_external_id()
{
    local key=$1
    local value=$2

    logger -t scripts-vif "vif${DOMID}.${DEVID} external-ids:\"${key}\"=\"${value}\""

    echo "-- set interface vif${DOMID}.${DEVID} external-ids:\"${key}\"=\"${value}\""
}

handle_vswitch_vif_details()
{
    local vm=$(xenstore-read "/local/domain/$DOMID/vm" 2>/dev/null)
    if [ $? -eq 0 -a -n "${vm}" ] ; then
        local vm_uuid=$(xenstore-read "$vm/uuid" 2>/dev/null)
    fi
    if [ -n "${vm_uuid}" ] ; then
        set_vif_external_id "xs-vm-uuid" "${vm_uuid}"
    fi

    local vif_uuid=$(xenstore-read "${PRIVATE}/vif-uuid" 2>/dev/null)
    if $xs550 && [ -z "${vif_uuid}" ] && [ -n "${vm_uuid}" ]; then
        vif_uuid=$(xe vif-list --minimal vm-uuid="${vm_uuid}" device=$DEVID)
    fi
    if [ -n "${vif_uuid}" ] ; then
        set_vif_external_id "xs-vif-uuid" "${vif_uuid}"
    fi

    local vif_details=
    local net_uuid=$(xenstore-read "${PRIVATE}/network-uuid" 2>/dev/null)
    if $xs550 && [ -z "${net_uuid}" ] && [ -n "${vif_uuid}" ]; then
        net_uuid=$(xe vif-param-get uuid="${vif_uuid}" param-name=network-uuid)
    fi
    if [ -n "${net_uuid}" ] ; then
        set_vif_external_id "xs-network-uuid" "${net_uuid}"
    fi

    local address=$(xenstore-read "/local/domain/$DOMID/device/vif/$DEVID/mac" 2>/dev/null)
    if [ -n "${address}" ] ; then
        set_vif_external_id "xs-vif-mac" "${address}"
    fi

    if $xs550; then
        # vNetManager needs to know the network UUID(s) associated with each
        # datapath.  Normally interface-reconfigure adds them, but XAPI does
        # not use interface-reconfigure for internal networks. Instead, XAPI
        # calls the addbr ioctl internally, so we have to do it here instead
        # for internal networks.  This is only acceptable because xapi is lazy
        # about creating internal networks: it only creates one just before it
        # adds the first vif to it.  There may still be a brief delay between
        # the initial ovs-vswitchd connection to vNetManager and setting this
        # configuration variable, but vNetManager can tolerate that.
        local bridge=$1
        if [ -n "${net_uuid}" ] ; then
            logger -t scripts-vif "${bridge} xs-network-uuids ${net_uuid}"
            echo "-- br-set-external-id $bridge xs-network-uuids ${net_uuid}"
        fi
    fi
}

add_to_bridge()
{
    local address=$(xenstore-read "${PRIVATE}/bridge-MAC")
    if [ $? -ne 0 -o -z "${address}" ]; then
        logger -t scripts-vif "Failed to read ${PRIVATE}/bridge-MAC from xenstore"
        exit 1
    fi
    local bridge=$(xenstore-read "${PRIVATE}/bridge")
    if [ $? -ne 0 -o -z "${bridge}" ]; then
        logger -t scripts-vif "Failed to read ${PRIVATE}/bridge from xenstore"
        exit 1
    fi
    logger -t scripts-vif "Adding ${dev} to ${bridge} with address ${address}"

    ${IP} link set "${dev}" down                        || logger -t scripts-vif "Failed to ip link set ${dev} down"
    ${IP} link set "${dev}" arp off                     || logger -t scripts-vif "Failed to ip link set ${dev} arp off"
    ${IP} link set "${dev}" multicast off               || logger -t scripts-vif "Failed to ip link set ${dev} multicast off"
    ${IP} link set "${dev}" address "${address}"        || logger -t scripts-vif "Failed to ip link set ${dev} address ${address}"
    ${IP} addr flush "${dev}"                           || logger -t scripts-vif "Failed to ip addr flush ${dev}"

    case $NETWORK_MODE in
    bridge)
        ${BRCTL} setfd "${bridge}" 0                    || logger -t scripts-vif "Failed to brctl setfd ${bridge} 0"
        ${BRCTL} addif "${bridge}" "${dev}"             || logger -t scripts-vif "Failed to brctl addif ${bridge} ${dev}"
        ;;
    openvswitch)
        if [ "$TYPE" = "vif" ] ; then
            local vif_details=$(handle_vswitch_vif_details $bridge)
        fi

        $vsctl -- --if-exists del-port $dev -- add-port $bridge $dev $vif_details
        ;;
    esac
        
    ${IP} link set "${dev}" up                          || logger -t scripts-vif "Failed to ip link set ${dev} up"
}

remove_from_bridge()
{
    case $NETWORK_MODE in
    bridge)
        # Nothing to do
        ;;
    openvswitch)
        # If ovs-brcompatd is running, it might already have deleted the
        # port.  Use --if-exists to suppress the error that would otherwise
        # arise in that case.
        $vsctl -- --if-exists del-port $dev
        ;;
    esac
}

NETWORK_MODE=$(cat /etc/xensource/network.conf)
ACTION=$1

# Older versions of XenServer do not pass in the type as an argument
if [[ $# -lt 2 ]]; then
    TYPE=vif
else
    TYPE=$2
fi

case $NETWORK_MODE in
    bridge|openvswitch) ;;
    vswitch) NETWORK_MODE=openvswitch ;;
    *)
        logger -t scripts-vif "Unknown network mode $NETWORK_MODE"
        exit 1
        ;;
esac

case ${TYPE} in
    vif)
        DOMID=`echo ${XENBUS_PATH} | cut -f 3 -d '/'`
        DEVID=`echo ${XENBUS_PATH} | cut -f 4 -d '/'`
        dev=vif${DOMID}.${DEVID}
        ;;
    tap)
        dev=$INTERFACE
        DOMID=`echo ${dev#tap} | cut -f 1 -d '.'`
        DEVID=`echo ${dev#tap} | cut -f 2 -d '.'`
        ;;
    *)  
        logger -t scripts-vif "unknown interface type ${TYPE}"
        exit 1
        ;;
esac

XAPI=/xapi/${DOMID}/hotplug/vif/${DEVID}
HOTPLUG=/xapi/${DOMID}/hotplug/vif/${DEVID}
PRIVATE=/xapi/${DOMID}/private/vif/${DEVID}

logger -t scripts-vif "Called as \"$@\" domid:$DOMID devid:$DEVID mode:$NETWORK_MODE"
case "${ACTION}" in
online)
    if [ "${TYPE}" = "vif" ] ; then
        handle_ethtool rx
        handle_ethtool tx
        handle_ethtool sg
        handle_ethtool tso
        handle_ethtool ufo
        handle_ethtool gso

        handle_mtu
        add_to_bridge
        handle_promiscuous

        xenstore-write "${HOTPLUG}/vif" "${dev}"
        xenstore-write "${HOTPLUG}/hotplug" "online"

        # xs-xen.pq.hq:91e986b8e49f netback-wait-for-hotplug
        xenstore-write "/local/domain/0/backend/vif/${DOMID}/${DEVID}/hotplug-status" "connected"
    fi
    ;;

add)
    if [ "${TYPE}" = "tap" ] ; then
        add_to_bridge
    fi
    ;;

remove)
    if [ "${TYPE}" = "vif" ] ;then
        xenstore-rm "${HOTPLUG}/hotplug"
    fi
    logger -t scripts-vif "${dev} has been removed"
    remove_from_bridge
    ;;
esac