UDP tunnel fails to deliver message

[niowniow]

Describe the bug

I'm trying to tunnel UDP traffic between two servers. The logs show that wstunnel establishes a connection, however the UDP message does not reach it's destination. If I replace the UDP tunnel with a TCP tunnel (and a http server) it works.

To Reproduce

On Server A

./wstunnel server --restrict-to localhost:8000 wss://[::]:8045

In a new terminal

nc -u -l -k -p 8000 -v

In a new terminal

echo "Test message" | nc -u 127.0.0.1 8000
# Sanity check. Works as expected, also multiple times

On Server B

echo "Test message from server B (directly)" | nc -u IP.OF.SERVER.A 8000
# Another check. works as expected

In a new terminal

./wstunnel client -L "udp://8000:localhost:8000" wss://IP.OF.SERVER.A:8045

In a new terminal

echo "Test message from server B" | nc -u 127.0.0.1 8000
# No message can be seen on the receiving end

Expected behavior

The UDP message is received on Server A

Your wstunnel setup

client

 ./wstunnel client -L "udp://8000:localhost:8000" wss://IP.OF.SERVER.A:8045 
2025-03-26T06:24:58.136967Z  INFO wstunnel: Starting wstunnel client v10.1.10
2025-03-26T06:24:58.137020Z  INFO wstunnel::protocols::udp::server: Starting UDP server listening cnx on 127.0.0.1:8000 with cnx timeout of 30s
2025-03-26T06:25:06.115385Z  INFO wstunnel::protocols::udp::server: New UDP connection from 127.0.0.1:51690
2025-03-26T06:25:06.115685Z  INFO wstunnel::protocols::tcp::server: Opening TCP connection to IP.OF.SERVER.A:8045    
2025-03-26T06:25:06.153938Z  INFO wstunnel::protocols::tls::server: Doing TLS handshake using SNI IpAddress(V4(Ipv4Addr([XX, XX, XX, XX]))) with the server IP.OF.SERVER.A:8045

server

./wstunnel server --restrict-to localhost:8000 wss://[::]:8045
2025-03-26T06:24:53.658417Z  INFO wstunnel::embedded_certificate: Generating self-signed tls certificate    
2025-03-26T06:24:53.659882Z  INFO wstunnel: Starting wstunnel server v10.1.10 with config WsServerConfig { socket_so_mark: SoMark { inner: None }, bind: [::]:8045, websocket_ping_frequency: Some(30s), timeout_connect: 10s, websocket_mask_frame: false, restriction_config: None, tls: true, remote_server_idle_timeout: 180s, mTLS: false }
2025-03-26T06:24:53.659992Z  INFO wstunnel::tunnel::server::server: Starting wstunnel server listening on [::]:8045
2025-03-26T06:25:06.178276Z  INFO cnx{peer="[::ffff:IP.OF.SERVER.B]:53026"}: wstunnel::tunnel::server::server: Accepting connection
2025-03-26T06:25:06.178545Z  INFO cnx{peer="[::ffff:IP.OF.SERVER.B]:53026"}: wstunnel::tunnel::server::server: Doing TLS handshake
2025-03-26T06:25:06.219107Z  INFO cnx{peer="[::ffff:IP.OF.SERVER.B]:53026"}:tunnel{id="0195d120-3e43-7ee1-9012-d9d11e568e84" remote="localhost:8000"}: wstunnel::tunnel::server::server: Tunnel accepted due to matched restriction: Allow All
2025-03-26T06:25:06.219194Z  INFO cnx{peer="[::ffff:IP.OF.SERVER.B]:53026"}:tunnel{id="0195d120-3e43-7ee1-9012-d9d11e568e84" remote="localhost:8000"}: wstunnel::protocols::udp::server: Opening UDP connection to localhost:8000
2025-03-26T06:25:06.219690Z  INFO cnx{peer="[::ffff:IP.OF.SERVER.B]:53026"}:tunnel{id="0195d120-3e43-7ee1-9012-d9d11e568e84" remote="localhost:8000"}: wstunnel::tunnel::server::server: connected to Udp { timeout: Some(30s) } localhost:8000

Desktop (please complete the following information):

Linux serverA 6.8.0-55-generic #57-Ubuntu SMP PREEMPT_DYNAMIC x86_64 x86_64 x86_64 GNU/Linux
Linux serverB 6.8.0-52-generic #53~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC x86_64 x86_64 x86_64 GNU/Linux

Additional context
I saw issue #380, however using version 9.7.4. also fails in this situation.