Module stun 

STUN client (RFC 5389) on a socket we own, plus NAT classification.

Two servers on different operators are queried so the answers can be compared: the same ip:port from both means a cone NAT and a usable reflexive candidate; the same IP with different ports means the mapping is chosen per destination — symmetric — and the port STUN saw is not the port the pilot would arrive on. Anycast within one provider could hide that, which is why two operators rather than one.

Structs

NatDiscovery

What STUN could work out about our position behind the NAT.

Enums

NatType

Constants

STUN_SERVERS

Functions

discover

Query every STUN server from sock and classify what we see.

discover_with_timeout

encode_binding_request

Encode a Binding Request with the given 12-byte transaction id.

encode_binding_response

Build a Binding Success Response carrying addr (test helper and useful for a future in-process STUN server).

parse_binding_response

Extract XOR-MAPPED-ADDRESS from a Binding Success Response for txid.