Module upnp 

UPnP/IGD method — ask the local Internet Gateway Device (via UPnP SSDP discovery + SOAP) to add a port mapping so inbound peer dials reach this node.

Unlike NAT-PMP/PCP, UPnP/IGD is a large protocol (SSDP multicast discovery + SOAP over HTTP), so we do NOT hand-roll it — we use the maintained igd-next crate for the live gateway call. It sits behind the same TraversalMethod trait as the other methods, so the ordering/fallback strategy is exercised with mock methods in tests and the live IGD call is covered only by an opt-in integration test (it needs a real UPnP gateway on the LAN).

Testability: the gateway interaction is abstracted behind the IgdGateway trait so the method’s own logic (map → yield dial address, or fail → fall through) is unit-tested with a fake gateway. RealIgd is the production implementation delegating to igd-next.

Structs

RealIgd

Production IgdGateway backed by igd-next (async tokio). Discovers the gateway via SSDP and adds a UDP mapping. Kept thin so the one real network call is isolated.

UpnpMethod

The UPnP/IGD traversal method. Adds a mapping via IgdGateway, then yields a dial address for the peer. Generic over the gateway so tests inject a fake.

Traits

IgdGateway

Abstraction over “add a port mapping on the local IGD”. Real impl talks to igd-next; tests use a fake so the method logic is verified with no network + no gateway.

Functions

local_ipv6

Best-effort GLOBAL (routable) local IPv6 address of this host, if any.

select_global_ipv6

Select the best IPv6 address to ADVERTISE from a set of the host’s candidate addresses: a global-unicast address is preferred; link-local (fe80::/10), ULA (fc00::/7), loopback, and unspecified addresses are rejected because they are not reachable by peers across the internet. IPv4 candidates are ignored. Returns the first global-unicast IPv6 candidate, or None.

Type Aliases

RealUpnpMethod

The production UPnP method (real IGD discovery).