nc server not recieving udp packets sent from the client using ebpf xdp

[der-ali]

Scenario:
Setup node01and node 02 with either static or bgp routing:

make setup_static 

Start a UDP server on one of the network namespaces on node01 with ebpf mode:

make test_udp_server_ebpf 

Send UDP packets to the server from a network namespace on node02:

make test_udp_client

nc server is not recieving the UDP packets!

Debug:
Capture tcp traffic on node01:

sudo ip netns exec con1 tcpdump -l -n -nn -vvv -i any port 1111

tcpdump shows bad udp cksum:

tcpdump: data link type LINUX_SLL2
tcpdump: listening on any, link-type LINUX_SLL2 (Linux cooked v2), snapshot length 262144 bytes
16:02:17.633509 veth11 P   IP (tos 0x0, ttl 64, id 11592, offset 0, flags [DF], proto UDP (17), length 34)
    172.16.0.1.33800 > 172.16.0.2.1111: [bad udp cksum 0xbd67 -> 0xbc67!] UDP, length 6

Display the trace output of the XDP program on node01:

sudo cat /sys/kernel/debug/tracing/trace_pipe

I suspect that the checksum logic in xdp.c not implemented correctly.