Struct PathRegistry 

pub struct PathRegistry { /* private fields */ }

Per-session collection of PathStates indexed by path_id.

Lock-free in the steady state (DashMap is lock-free for reads); per-path validation operations take only the per-path Mutex on the pending challenge, which is uncontended outside of the brief window of an active challenge round-trip.

Implementations

impl PathRegistry

pub fn new() -> Self

pub fn register(&self, path_id: u8) -> RegistrationResult

Register a new path id if it doesn’t already exist. Returns Created if this call created the entry — caller is the one that should now issue a validation challenge.

pub fn register_validated(&self, path_id: u8) -> RegistrationResult

Register a new path id directly in the Validated state, skipping the challenge-response round trip. Used for the implicit path_id = 0 initialised at session establishment — that path is the one the handshake itself traversed, so the AEAD setup itself was already a stronger proof of reachability than any PATH_CHALLENGE would be.

Returns Created if this call created the entry. If the entry already existed, its state is NOT modified — the caller must explicitly drive a challenge-response if they want to change it.

pub fn mark_seen(&self, path_id: u8)

Update last_packet_seen on the path. No-op for unknown paths.

pub fn issue_challenge(&self, path_id: u8) -> Option<[u8; 32]>

Allocate a fresh challenge for the path and transition it to Validating. The caller is responsible for transmitting the returned bytes (typically inside a PATH_VALIDATION-flagged V2 packet).

Returns None if the path is unknown or if it is already in Validated / Failed (re-issuing a challenge from those terminal states is the caller’s explicit decision).

pub fn verify_response(&self, path_id: u8, response: &[u8]) -> bool

Verify a peer’s response to a previously-issued challenge. On a constant-time match, transitions the path to Validated and returns true. On mismatch or unknown state, transitions to Failed and returns false. On unknown path, returns false without side-effects.

subtle::ConstantTimeEq is used so a timing observer cannot distinguish “wrong byte at position 0” from “wrong byte at position 31” — same posture as the cookie check in transport::handshake::validate_cookie.

pub fn state(&self, path_id: u8) -> Option<PathStateKind>

Current state of a path. Returns None for unknown ids.

pub fn validated_paths(&self) -> Vec<u8>

Snapshot of all path ids currently in Validated.

pub fn len(&self) -> usize

Number of paths in any state.

pub fn is_empty(&self) -> bool

Trait Implementations

impl Default for PathRegistry

fn default() -> Self

Returns the “default value” for a type.