Yeah, you can use sendmsg(2) with special flags to send a file descriptor over a unix socket or iirc also a pipe. It's very useful with kernel-tls or multi-pro

Yeah, you can use sendmsg(2) with special flags to send a file descriptor over a unix socket or iirc also a pipe. It's very useful with kernel-tls or multi-process web servers, to handle no key at all in the worker thread itself or shard processes by something only known after connection establishment, like the HTTP Host header or tls SNI.