#!/bin/sh

BRIDGE=br0
IFNAME=tap0

# Network information
NETWORK=10.0.2.0
NETMASK=255.255.255.0
GATEWAY=10.0.2.1
DHCPRANGE=10.0.2.2,10.0.2.254

# Optionally parameters to enable PXE support
TFTPROOT=
BOOTP=

do_brctl() {
    /usr/bin/sudo /sbin/brctl "$@"
}

do_ifconfig() {
    /usr/bin/sudo /bin/ifconfig "$@"
}

do_dnsmasq() {
    /usr/bin/sudo /usr/sbin/dnsmasq "$@"
}

check_bridge() {
    if do_brctl show | grep "^$1" > /dev/null 2> /dev/null; then
    return 1
    else
    return 0
    fi
}

create_bridge() {
    do_brctl addbr "$1"
    do_brctl stp "$1" off
    do_ifconfig "$1" "$GATEWAY" netmask "$NETMASK" up
}

start_dnsmasq() {
    do_dnsmasq \
    --strict-order \
    --except-interface=lo \
    --interface=$BRIDGE \
    --listen-address=$GATEWAY \
    --bind-interfaces \
    --dhcp-range=$DHCPRANGE \
    --dhcp-option=15,example.com \
    --conf-file="" \
    --pid-file=/var/run/qemu-dnsmasq-$BRIDGE.pid \
    --dhcp-leasefile=/var/run/qemu-dnsmasq-$BRIDGE.leases \
    --dhcp-no-override \
    ${TFTPROOT:+"--enable-tftp"} \
    ${TFTPROOT:+"--tftp-root=$TFTPROOT"} \
    ${BOOTP:+"--dhcp-boot=$BOOTP"}
}

setup_bridge() {
    if check_bridge "$1" ; then
    create_bridge "$1"
    start_dnsmasq "$1"
        if test "$2" ; then
            do_ifconfig "$2" 0.0.0.0 up
            do_brctl addif "$BRIDGE" "$2"
        fi
    fi
}

setup_bridge "$BRIDGE" "$1"