UDP apps break when tunneled through webstransport

[alou-S]

Describe the bug

Trying to tunnel Wireguard through wstunnel in wts mode causes the Wireguard tunnel to behave weirdly and perform abysmally. (Extremely variable and often low speeds but ICMP ping seems just fine with no loss)

I've also tried simply exposing a HTTP3 caddy server directly through wstunnel in wts mode and it seems to have weird behaviour too where the file never starts downloading through curl (Curl seems to establish the connection to the http3 server just fine, no data is sent though)

Other Notes

• Both Wireguard and http3 caddy work just fine when using the websocket mode.
• TCP over webtransport seems to be working just fine. (Only tested TCP HTTPS and TCP iperf3 through wts)

Your wstunnel setup

• Server : ./wstunnel server wts://0.0.0.0:443
• Client: ./wstunnel client wts://10.10.0.1:443 -L "tcp://51242:127.0.0.1:51242?timeout_sec=0" -L "udp://51242:127.0.0.1:51242?timeout_sec=0"

OS and Build Inforamtion

• OS: Linux x86
• wstunnel version: git-14168c5
• wstunnel build flags : cargo build --package wstunnel-cli --target x86_64-unknown-linux-gnu --release