#!/bin/bash
#

# Copyright (C) 2011, 2012, 2013 Google Inc.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# 1. Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
# IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

@SHELL_ENV_INIT@

readonly GANETI_TAP="gnt.com"

function check {
  if [ -z "$INTERFACE" ]; then
    echo "No network interface specified"
    exit 1
  fi

  if [ -z "$MODE" ]; then
    echo "MODE not specified"
    exit 1
  fi
}

function is_instance_communication_tap {
  COMMUNICATION=$(echo "$INTERFACE" | cut -d "." -f 1-2)

  if [ "$MODE" = "routed" -a "$COMMUNICATION" = "$GANETI_TAP" ]
  then
    return 0
  else
    return 1
  fi
}

function fix_mac {
  # Fix the autogenerated MAC to have the first octet set to "fe"
  # to discourage the bridge from using the TAP dev's MAC
  FIXED_MAC=$(ip link show $INTERFACE | \
    awk '{if ($1 == "link/ether") printf("fe%s",substr($2,3,15))}')
  # in case of a vif (xen_netback device) this action is not allowed
  ip link set $INTERFACE address $FIXED_MAC || true
}

function setup_bridge {
  if [ "$MODE" = "bridged" ]; then
    fix_mac
    ip link set $INTERFACE up
    ip link set $INTERFACE mtu $(</sys/class/net/${LINK}/mtu)

    # Connect the interface to the bridge
    brctl addif $LINK $INTERFACE
  fi
}

function setup_ovs {
  if [ "$MODE" = "openvswitch" ]; then
    # Remove stale port
    ovs-vsctl del-port $INTERFACE || true
    # Bring interface up
    ip link set $INTERFACE up
    # Add port
    ovs-vsctl add-port ${LINK} $INTERFACE
    # Set up access port
    # From gnt-instance man page vlan should be either .VLAN_ID or VLAN_ID
    ACPORT=${VLAN%%:*}  # remove any trunk info
    [ -n "$ACPORT" ] && ovs-vsctl set port $INTERFACE tag=${ACPORT#.}
    # Set up trunk port
    # From gnt-instance man page vlan should be :VLAN_ID[:VLAN_ID2..]
    TRUNKS=${VLAN#.*:}  # remove any access info
    [ -n "$TRUNKS" ] && ovs-vsctl set port $INTERFACE trunks=${TRUNKS//:/,}

  fi
}

function setup_route {
  if [ "$MODE" = "routed" ]; then
    ip link set $INTERFACE up

    if [ -z "$IP" ]; then
      echo "Routed NIC but no IP address specified"
      exit 1
    fi

    # Route traffic targeted at the IP to the interface
    if [ -n "$LINK" ]; then
      while ip rule del dev $INTERFACE; do :; done
      ip rule add dev $INTERFACE table $LINK
      ip route replace $IP table $LINK proto static dev $INTERFACE

    else
      ip route replace $IP proto static dev $INTERFACE
    fi

    # Allow routing and arp proxying, or ndp proxying (IPv6)
    if [ -d "/proc/sys/net/ipv4/conf/$INTERFACE" ]; then
      echo 1 > /proc/sys/net/ipv4/conf/$INTERFACE/proxy_arp
      echo 1 > /proc/sys/net/ipv4/conf/$INTERFACE/forwarding
    fi

    if [ -d "/proc/sys/net/ipv6/conf/$INTERFACE" ]; then
      echo 1 > /proc/sys/net/ipv6/conf/$INTERFACE/proxy_ndp
      echo 1 > /proc/sys/net/ipv6/conf/$INTERFACE/forwarding
    fi
  fi
}