Nginx UDP Proxying

Question

I have an Nginx config that looks like:

user  nginx;
worker_processes  auto;

error_log  /var/log/nginx/error.log notice;
pid        /var/run/nginx.pid;


events {
    worker_connections  1024;
}

stream {

  log_format basic '$remote_addr [$time_local] '
                   '$protocol $status $bytes_sent $bytes_received '
                   '$session_time';

  server {
    listen 1194 udp reuseport;
    access_log /var/log/nginx/stream-access.log basic;
    proxy_pass vpn;
    proxy_bind $remote_addr transparent;
    proxy_responses 0;
    proxy_timeout 1s;
  }
  server {
    listen 1195 udp;
    return "data";
  }
  upstream vpn {
    server 127.0.0.1:1195;
  }
}

And I can send and receive data on port 1195, like so:

$ echo -n "hello" | nc -4u -w1 127.0.0.1 1195
data

But if I try to use the proxy and sent to port 1194 I dont get any data back.

$ echo -n "hello" | nc -4u -w1 127.0.0.1 1194

Might anyone know why?

Also this is what the log look like:

127.0.0.1 [26/Apr/2024:16:38:52 +0000] UDP 200 0 5 0.000

Answer 1

I do think I figured it out. The directive proxy_responses 0; does not expect or return any answers, so I removed it and it worked as expected.

I was trying to tunnel my Wireguard (DNS) VPN through Nginx but could not get it to work as expected so I gave up.