Struct UdpConfig 

pub struct UdpConfig {
    pub bind_addr: Option<String>,
    pub mtu: Option<u16>,
    pub recv_buf_size: Option<usize>,
    pub send_buf_size: Option<usize>,
    pub advertise_on_nostr: Option<bool>,
    pub public: Option<bool>,
    pub external_addr: Option<String>,
    pub outbound_only: Option<bool>,
    pub accept_connections: Option<bool>,
}

UDP transport instance configuration.

Fields

bind_addr: Option<String>

Bind address (bind_addr). Defaults to “0.0.0.0:2121”.

When outbound_only = true, this field is ignored and the transport binds to 0.0.0.0:0 (kernel-assigned ephemeral port) regardless.

mtu: Option<u16>

UDP MTU (mtu). Defaults to 1280 (IPv6 minimum).

recv_buf_size: Option<usize>

UDP receive buffer size in bytes (recv_buf_size). Defaults to 16 MiB.

send_buf_size: Option<usize>

UDP send buffer size in bytes (send_buf_size). Defaults to 8 MiB.

advertise_on_nostr: Option<bool>

Whether this transport should be advertised on Nostr overlay discovery. Default: false. Implicitly forced false when outbound_only = true.

public: Option<bool>

Whether UDP should be advertised as directly reachable (host:port) on Nostr. When false and advertised, UDP is emitted as addr: "nat" to trigger rendezvous traversal.

Default: false.

external_addr: Option<String>

Optional explicit public address to advertise when public: true is set. Takes precedence over both the bound address and any STUN-derived autodiscovery. Accepts either a bare IP ("198.51.100.1" — the configured bind_addr port is appended) or a full host:port ("198.51.100.1:443"). Useful when the public IP isn’t on a local interface (e.g. AWS EIP / cloud 1:1 NAT) and the operator wants to skip STUN autodiscovery for a deterministic value.

outbound_only: Option<bool>

Outbound-only mode. When true, the transport binds to a kernel- assigned ephemeral port (0.0.0.0:0) instead of the configured bind_addr, refuses inbound handshake msg1, and is never advertised on Nostr regardless of advertise_on_nostr. Use this to participate in the mesh as a pure client — initiate outbound links without exposing an inbound listener on a known port. Default: false.

accept_connections: Option<bool>

Accept inbound handshake msg1 from new peers. Default: true. Setting this to false combined with auto_connect: true on peer-side configurations gives a “client” posture: this node initiates outbound links but refuses inbound handshakes from unfamiliar addresses. The Node-level gate at src/node/handlers/handshake.rs carves out msg1 from peers already established on this transport (so rekey continues to work) — see ISSUE-2026-0004.

Implementations

impl UdpConfig

pub fn bind_addr(&self) -> &str

Get the bind address, using default if not configured.

When outbound_only = true, returns 0.0.0.0:0 so the kernel picks an ephemeral source port and no listener is exposed on a known port.

pub fn mtu(&self) -> u16

Get the UDP MTU, using default if not configured.

pub fn recv_buf_size(&self) -> usize

Get the receive buffer size, using default if not configured.

pub fn send_buf_size(&self) -> usize

Get the send buffer size, using default if not configured.

pub fn advertise_on_nostr(&self) -> bool

Whether this UDP transport should be advertised on Nostr discovery. Always false when outbound_only = true.

pub fn is_public(&self) -> bool

Whether this UDP transport should be advertised as directly reachable.

pub fn external_advert_addr(&self) -> Option<SocketAddr>

Parse external_addr against the configured bind_addr port, returning the absolute SocketAddr to advertise on Nostr. Returns None if external_addr is unset or malformed, or if the port cannot be inferred.

pub fn outbound_only(&self) -> bool

Whether this transport runs in outbound-only mode. Default: false.

pub fn accept_connections(&self) -> bool

Whether this transport accepts inbound handshakes. Default: true.

Trait Implementations

impl Clone for UdpConfig

fn clone(&self) -> UdpConfig

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for UdpConfig

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for UdpConfig

fn default() -> UdpConfig

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for UdpConfig

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for UdpConfig

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.