#
# Copyright (c) 2005 XenSource Ltd.
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of version 2.1 of the GNU Lesser General Public
# License as published by the Free Software Foundation.
#
# This library 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.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#


preiftransfer()
{
  # Ensure the interface has an IP to transfer
  /sbin/ifrenew $1 -o rc || true
}

ifup()
{
  /sbin/ifup $1 -o rc || true
}

ifdown()
{
  /sbin/ifdown $1 -o rc
}

first_file()
{
  t="$1"
  shift
  for file in $@
  do
    if [ "$t" "$file" ]
    then
      echo "$file"
      return
    fi
  done
}

find_dhcpd_conf_file()
{
  first_file -f /etc/dhcp3/dhcpd.conf /etc/dhcpd.conf
}


find_dhcpd_init_file()
{
  first_file -x /etc/init.d/{dhcp3-server,dhcp,dhcpd}
}

# configure interfaces which act as pure bridge ports:
#  - make quiet: no arp, no multicast (ipv6 autoconf)
#  - set mac address to fe:ff:ff:ff:ff:ff
setup_bridge_port() {
    local dev="$1"

    # take interface down ...
    ip link set ${dev} down

    # ... and configure it
    ip link set ${dev} arp off
    ip link set ${dev} multicast off
    ip link set ${dev} addr fe:ff:ff:ff:ff:ff
    ip addr flush ${dev}
}

# Usage: create_bridge bridge
create_bridge () {
    local bridge=$1

    # Don't create the bridge if it already exists.
    if [ ! -e "/sys/class/net/${bridge}/bridge" ]; then
	brctl addbr ${bridge}
	brctl stp ${bridge} off
	brctl setfd ${bridge} 0
        ip link set ${bridge} arp off
        ip link set ${bridge} multicast off
    fi

    # A small MTU disables IPv6 (and therefore IPv6 addrconf).
    mtu=$(ip link show ${bridge} | sed -n 's/.* mtu \([0-9]\+\).*/\1/p')
    ip link set ${bridge} mtu 68
    ip link set ${bridge} up
    ip link set ${bridge} mtu ${mtu:-1500}
}

# Usage: add_to_bridge bridge dev
add_to_bridge () {
    local bridge=$1
    local dev=$2

    # Don't add $dev to $bridge if it's already on a bridge.
    if [ -e "/sys/class/net/${bridge}/brif/${dev}" ]; then
	ip link set ${dev} up || true
	return
    fi
    brctl addif ${bridge} ${dev}
    ip link set ${dev} up
}