#!/bin/bash -ex

# Manage a venv-based virtual network for testing, consisting of:
#
# - venv0: Interface for the DHCP server (static address: 10.0.0.254/24)
# - venv1: Interface for DHCP client
# - br-dhcp: A bridge for communication between these interfaces
#
# Default behavior is to create the network, the `-d` option removes it.

BR=br-dhcp
SERVERADDR="10.0.0.254/24"

# Parse arguments
DELETE=0
while getopts "d" opt; do
    case $opt in
        d)
            DELETE=1
            ;;
        *)
            ;;
    esac
done

if [ "$DELETE" != "0" ]; then
    for i in {0..1}; do
        IFNAME="veth${i}"
        ip link del "$IFNAME" || true
    done
    ip link set "$BR" down
    brctl delbr $BR
    exit 0
fi


brctl addbr $BR

for i in {0..1}; do
    IFNAME="veth${i}"
    PEERNAME="${IFNAME}s"

    ip link add "$IFNAME" type veth peer name "$PEERNAME"
    ip link set "$IFNAME" up
    ip link set "$PEERNAME" up

    brctl addif $BR "$PEERNAME"
done

ip addr add dev veth0 "$SERVERADDR"
ip link set "$BR" up