Post #2019984
2026-05-02 18:59 UTC
@patrick I'm happy to see another SNI middlebox! I like the concept; I wrote about the advantages a few years ago: https://jamey.thesharps.us/2020/04/24/most-general-reverse-proxy/
How are you using eBPF to make the client address visible to the backend? I had looked into that but it seemed like the best I could do was passing SKBs from one socket to another, which I thought wouldn't carry the remote address info along. I also considered using Unix socket file descriptor-passing, but then needed some way to peek at the initial part of the stream without consuming it, and also would have needed to modify backends to get incoming sockets that way instead of by calling accept. So I'd love to hear how you apparently got the best of all worlds!
Replies (1)
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@patrick@retro.social 2026-05-02 19:03
@jamey IP_TRANSPARENT to force a source IP for the new connection. That has consequences when you want to route to some other system with a default route that doesn't pass by your SNI proxy by default, but locally (or on gateways) it works splendidly.