stand

#!/bin/sh

[ $# -ge 1 ] || { echo >&2 "Usage: $0 {up|down|status|attach|detach|log|exec|listen}"; exit 1; }
[ $UID -eq 0 ] || { echo >&2 "This script requires root."; exit 1; }

action="$1"
netns=xdp-test
local=xdp-local
remote=xdp-remote
dummy=xdp_dummy.o
filter=xdp_filter.o

case "$action" in
up)
    ip netns add ${netns}
    ip link add ${remote} type veth peer name ${local}
    ip link set ${remote} netns ${netns}
    ip netns exec ${netns} ip address add 192.0.2.2/24 dev ${remote}
    ip netns exec ${netns} ip link set ${remote} up
    ip address add 192.0.2.1/24 dev ${local}
    ip link set ${local} up
    ;;

down)
    ip netns delete ${netns}
    ip link delete ${local}
    ;;

status)
    if ip netns list | grep ${netns} 2>&1 >/dev/null; then
        echo "Stand is UP."
    else
        echo "Stand is DOWN."
    fi
    ;;

attach)
    ip netns exec ${netns} ip -force link set dev ${remote} xdp object ${dummy} >/dev/null
    ip -force link set dev ${local} xdp object ${filter} verbose
    ;;

detach)
    ip netns exec ${netns} ip link set dev ${remote} xdp off
    ip link set dev ${local} xdp off
    ;;

log)
    echo -n 1 > /sys/kernel/debug/tracing/options/trace_printk
    cat /sys/kernel/debug/tracing/trace_pipe
    ;;

exec)
    shift
    ip netns exec ${netns} $@
    ;;

listen)
    ip netns exec ${netns} tcpdump -tnevi ${remote} not ip6
    ;;
esac