Safe Haskell	None
Language	GHC2021

LibP2P.NAT.AutoNAT

Contents

Types
Server
Client
NAT status aggregation

Description

AutoNAT v1 service: detect NAT status by asking remote peers to dial back.

Protocol: libp2pautonat/1.0.0 Flow: Client sends DIAL with addresses, server dials back, responds with result.

Security rules (from specs/autonat): - Server MUST NOT dial addresses unless they match the requester's observed IP (both IPv4 and IPv6; if the observed IP cannot be determined, refuse) - Server MUST NOT accept dial requests over relayed connections - Server rejects requests whose claimed peer id differs from the authenticated peer id of the connection

Synopsis

data NATStatus
- = NATPublic
- | NATPrivate
- | NATUnknown
data AutoNATConfig = AutoNATConfig {
- natThreshold :: !Int
- natDialBack :: !(PeerId -> [Multiaddr] -> IO (Either String Multiaddr))
}
maxDialBackAddrs :: Int
handleAutoNAT :: AutoNATConfig -> StreamIO -> PeerId -> Multiaddr -> IO ()
requestAutoNAT :: StreamIO -> PeerId -> [Multiaddr] -> IO (Either String AutoNATDialResponse)
probeNATStatusPure :: Int -> [Either String AutoNATDialResponse] -> NATStatus

Types

data NATStatus Source #

Detected NAT status.

Constructors

NATPublic
NATPrivate
NATUnknown

Instances

Instances details

Show NATStatus Source #
Instance details Defined in LibP2P.NAT.AutoNAT Methods showsPrec :: Int -> NATStatus -> ShowS # show :: NATStatus -> String # showList :: [NATStatus] -> ShowS #
Eq NATStatus Source #
Instance details Defined in LibP2P.NAT.AutoNAT Methods (==) :: NATStatus -> NATStatus -> Bool # (/=) :: NATStatus -> NATStatus -> Bool #

data AutoNATConfig Source #

AutoNAT configuration.

Constructors

AutoNATConfig
Fields natThreshold :: !Int Need strictly more than this many agreeing votes (specs/autonat: "more than 3"). Default 3 therefore requires four valid reports. natDialBack :: !(PeerId -> [Multiaddr] -> IO (Either String Multiaddr)) Injectable dial-back; on success returns the address that worked.

maxDialBackAddrs :: Int Source #

Maximum number of addresses dialled back per request. Bounds the work a single request can trigger (go-libp2p applies a similar per-request address cap).

Server

handleAutoNAT :: AutoNATConfig -> StreamIO -> PeerId -> Multiaddr -> IO () Source #

Server handler: receive DIAL, validate, dial back, respond.

Security: - Rejects requests from relayed connections (P2PCircuit in observed addr) - Filters dial-back addresses to match observed IP

AutoNAT is a one-shot exchange, so the stream is closed on every exit path (go-libp2p's handleStream uses defer s.Close()).

Client

requestAutoNAT :: StreamIO -> PeerId -> [Multiaddr] -> IO (Either String AutoNATDialResponse) Source #

Client: send DIAL with local addresses, receive response.

One-shot: the stream is closed after the exchange on every exit path, matching go-libp2p's AutoNAT client (defer s.Close()).

NAT status aggregation

probeNATStatusPure :: Int -> [Either String AutoNATDialResponse] -> NATStatus Source #

Pure aggregation of AutoNAT results into a NAT status.

Only a remote dial report counts as a vote: StatusOK is public, EDialError is private. Local failures (Left), refusals, and malformed responses are abstentions (specs/autonat: infer from successful or unsuccessful *dial reports*). A decision requires strictly more than threshold agreeing votes.