Struct ListenerConfig 

pub struct ListenerConfig {
    pub bind_addr: SocketAddr,
    pub cert_chain: Vec<CertificateDer<'static>>,
    pub key_der: PrivateKeyDer<'static>,
    pub transport_config: Option<Arc<TransportConfig>>,
    pub transport_profile: Option<TransportProfile>,
    pub installer: Option<Arc<dyn TransportInstaller>>,
}

Configuration for the proxy’s listener.

Fields

bind_addr: SocketAddr

Address to bind to (e.g., "0.0.0.0:4443").

cert_chain: Vec<CertificateDer<'static>>

TLS certificate chain (DER-encoded).

key_der: PrivateKeyDer<'static>

TLS private key (DER-encoded).

transport_config: Option<Arc<TransportConfig>>

Optional QUIC transport parameters — flow-control windows, MTU, keep-alive, congestion control — applied to every client connection this listener accepts.

None leaves quinn’s defaults in place, which is the behaviour callers had before this field existed.

Setting this and ListenerConfig::transport_profile is refused by Listener::bind rather than merged, with ProxyError::TransportConfigAndProfile naming Leg::Client — see that variant for why no merge is possible.

transport_profile: Option<TransportProfile>

The same parameters as ListenerConfig::transport_config, as a value that can be written down, checked and stored.

Some(_) builds the client leg’s quinn::TransportConfig from this profile — through ListenerConfig::installer, or through transport::DefaultInstaller when there is none — and installs it before the endpoint exists. A profile the installer refuses is ProxyError::TransportProfile, and nothing is bound.

None is the behaviour callers had before this field existed. It is the only alternative to transport_config, never a companion to it: a leg naming both is refused at bind time.

installer: Option<Arc<dyn TransportInstaller>>

How ListenerConfig::transport_profile becomes the config this leg installs.

None uses transport::DefaultInstaller, which applies the profile over a fresh quinn::TransportConfig::default(). Supply one to start from a base of your own instead — the trait exists because a quinn::TransportConfig cannot be cloned, so the only way to have a base and a profile is to build the base again for each leg.

Inert without a profile. TransportInstaller::build takes a profile, so an installer set beside an empty ListenerConfig::transport_profile is never called and the leg installs nothing. It is said here because a setting that is quietly ignored is the failure this crate is least willing to hide.

It composes with a qlog spec — named in plain code font because that field exists only under the qlog feature, so a link from this always-compiled one would not resolve. A leg carrying a profile, a spec and an installer builds its config here, once, and the capture sink is attached to what came back; TransportInstaller::build returns an owned quinn::TransportConfig precisely so that the two can stack.