Struct Connection 

pub struct Connection<State = HandshakeCompleted>
where
    State: ConnectionState,
{ /* private fields */ }

A QUIC connection.

If all references to a connection (including every clone of the Connection handle, streams of incoming streams, and the various stream types) have been dropped, then the connection will be automatically closed with an error_code of 0 and an empty reason. You can also close the connection explicitly by calling Connection::close.

Closing the connection immediately abandons efforts to deliver data to the peer. Upon receiving CONNECTION_CLOSE the peer may drop any stream data not yet delivered to the application. Connection::close describes in more detail how to gracefully close a connection without losing application data.

May be cloned to obtain another handle to the same connection.

Implementations

impl<T> Connection<T>

where T: ConnectionState,

pub fn open_uni(&self) -> OpenUni<'_>

Initiates a new outgoing unidirectional stream.

Streams are cheap and instantaneous to open unless blocked by flow control. As a consequence, the peer won’t be notified that a stream has been opened until the stream is actually used.

pub fn open_bi(&self) -> OpenBi<'_>

Initiates a new outgoing bidirectional stream.

Streams are cheap and instantaneous to open unless blocked by flow control. As a consequence, the peer won’t be notified that a stream has been opened until the stream is actually used. Calling open_bi then waiting on the RecvStream without writing anything to SendStream will never succeed.

pub fn accept_uni(&self) -> AcceptUni<'_>

Accepts the next incoming uni-directional stream.

pub fn accept_bi(&self) -> AcceptBi<'_>

Accept the next incoming bidirectional stream.

Important Note: The peer that calls open_bi must write to its SendStream before the peer Connection is able to accept the stream using accept_bi(). Calling open_bi then waiting on the RecvStream without writing anything to the connected SendStream will never succeed.

pub fn read_datagram(&self) -> ReadDatagram<'_>

Receives an application datagram.

pub async fn closed(&self) -> ConnectionError

Wait for the connection to be closed for any reason.

Despite the return type’s name, closed connections are often not an error condition at the application layer. Cases that might be routine include ConnectionError::LocallyClosed and ConnectionError::ApplicationClosed.

pub fn close_reason(&self) -> Option<ConnectionError>

If the connection is closed, the reason why.

Returns None if the connection is still open.

pub fn close(&self, error_code: VarInt, reason: &[u8])

Closes the connection immediately.

Pending operations will fail immediately with ConnectionError::LocallyClosed. No more data is sent to the peer and the peer may drop buffered data upon receiving the CONNECTION_CLOSE frame.

error_code and reason are not interpreted, and are provided directly to the peer.

reason will be truncated to fit in a single packet with overhead; to improve odds that it is preserved in full, it should be kept under 1KiB.

Gracefully closing a connection

Only the peer last receiving application data can be certain that all data is delivered. The only reliable action it can then take is to close the connection, potentially with a custom error code. The delivery of the final CONNECTION_CLOSE frame is very likely if both endpoints stay online long enough, calling Endpoint::close will wait to provide sufficient time. Otherwise, the remote peer will time out the connection, provided that the idle timeout is not disabled.

The sending side can not guarantee all stream data is delivered to the remote application. It only knows the data is delivered to the QUIC stack of the remote endpoint. Once the local side sends a CONNECTION_CLOSE frame in response to calling close the remote endpoint may drop any data it received but is as yet undelivered to the application, including data that was acknowledged as received to the local endpoint.

pub fn send_datagram(&self, data: Bytes) -> Result<(), SendDatagramError>

Transmits data as an unreliable, unordered application datagram.

Application datagrams are a low-level primitive. They may be lost or delivered out of order, and data must both fit inside a single QUIC packet and be smaller than the maximum dictated by the peer.

pub fn send_datagram_wait(&self, data: Bytes) -> SendDatagram<'_>

Transmits data as an unreliable, unordered application datagram

Unlike send_datagram(), this method will wait for buffer space during congestion conditions, which effectively prioritizes old datagrams over new datagrams.

See send_datagram() for details.

pub fn max_datagram_size(&self) -> Option<usize>

Computes the maximum size of datagrams that may be passed to send_datagram.

Returns None if datagrams are unsupported by the peer or disabled locally.

This may change over the lifetime of a connection according to variation in the path MTU estimate. The peer can also enforce an arbitrarily small fixed limit, but if the peer’s limit is large this is guaranteed to be a little over a kilobyte at minimum.

Not necessarily the maximum size of received datagrams.

pub fn datagram_send_buffer_space(&self) -> usize

Bytes available in the outgoing datagram buffer.

When greater than zero, calling send_datagram with a datagram of at most this size is guaranteed not to cause older datagrams to be dropped.

pub fn rtt(&self, path_id: PathId) -> Option<Duration>

Current best estimate of this connection’s latency (round-trip-time).

pub fn stats(&self) -> ConnectionStats

Returns connection statistics.

pub fn congestion_state(&self, path_id: PathId) -> Option<Box<dyn Controller>>

Current state of the congestion control algorithm, for debugging purposes.

pub fn handshake_data(&self) -> Option<Box<dyn Any>>

Parameters negotiated during the handshake.

Guaranteed to return Some on fully established connections or after Connecting::handshake_data() succeeds. See that method’s documentations for details on the returned value.

pub fn peer_identity(&self) -> Option<Box<dyn Any>>

Cryptographic identity of the peer.

The dynamic type returned is determined by the configured Session. For the default rustls session, the return value can be downcast to a Vec<rustls::pki_types::CertificateDer>

pub fn stable_id(&self) -> usize

A stable identifier for this connection.

Peer addresses and connection IDs can change, but this value will remain fixed for the lifetime of the connection.

pub fn export_keying_material( &self, output: &mut [u8], label: &[u8], context: &[u8], ) -> Result<(), ExportKeyingMaterialError>

Derives keying material from this connection’s TLS session secrets.

When both peers call this method with the same label and context arguments and output buffers of equal length, they will get the same sequence of bytes in output. These bytes are cryptographically strong and pseudorandom, and are suitable for use as keying material.

See RFC5705 for more information.

pub fn set_max_concurrent_uni_streams(&self, count: VarInt)

Modifies the number of unidirectional streams that may be concurrently opened.

No streams may be opened by the peer unless fewer than count are already open. Large counts increase both minimum and worst-case memory consumption.

pub fn set_receive_window(&self, receive_window: VarInt)

See noq_proto::TransportConfig::receive_window.

pub fn set_max_concurrent_bi_streams(&self, count: VarInt)

Modifies the number of bidirectional streams that may be concurrently opened.

No streams may be opened by the peer unless fewer than count are already open. Large counts increase both minimum and worst-case memory consumption.

impl Connection

pub fn alpn(&self) -> &[u8]

Extracts the ALPN protocol from the peer’s handshake data.

pub fn remote_id(&self) -> PublicKey

Returns the EndpointId from the peer’s TLS certificate.

The PublicKey of an endpoint is also known as an EndpointId. This PublicKey is included in the TLS certificate presented during the handshake when connecting. This function allows you to get the EndpointId of the remote endpoint of this connection.

pub fn paths(&self) -> PathWatcher

Returns a Watcher for the network paths of this connection.

A connection can have several network paths to the remote endpoint, commonly there will be a path via the relay server and a holepunched path.

Returns a PathWatcher, which implements the Watcher trait. The watcher is updated whenever a path is opened or closed, or when the path selected for transmission changes (see PathInfo::is_selected).

The PathInfoList returned from the watcher contains a PathInfo for each network path.

As long as a PathWatcher is alive, the list of paths will only grow. If paths are closed, they will be marked as closed (see PathInfo::is_closed) but will not be removed from the list of paths. This allows to reliably retrieve stats for closed paths.

A PathWatcher does not keep the Connection itself alive. If all references to a connection are dropped, the PathWatcher will start to return an error when updating. Its last value may still be used - note however that accessing stats for a path via PathInfo::stats returns None if all references to a Connection have been dropped. To reliably access path stats when a connection closes, wait for Connection::closed and then call Connection::paths and directly iterate over the path stats while the Connection struct is still in scope.

pub fn side(&self) -> Side

Returns the side of the connection (client or server).

pub fn to_info(&self) -> ConnectionInfo

Returns a connection info struct.

A ConnectionInfo is a weak handle to the connection that does not keep the connection alive, but does allow to access some information about the connection and to wait for the connection to be closed.

impl Connection<IncomingZeroRtt>

pub fn alpn(&self) -> Option<Vec<u8>>

Extracts the ALPN protocol from the peer’s handshake data.

pub async fn handshake_completed(&self) -> Result<Connection, ConnectingError>

Waits until the full handshake occurs and then returns a Connection.

This may fail with ConnectingError::ConnectionError, if there was some general failure with the connection, such as a network timeout since we accepted the connection.

This may fail with ConnectingError::HandshakeFailure, if the other side doesn’t use the right TLS authentication, which usually every iroh endpoint uses and requires.

Thus, those errors should only occur if someone connects to you with a modified iroh endpoint or with a plain QUIC client.

pub fn remote_id(&self) -> Result<PublicKey, RemoteEndpointIdError>

Returns the EndpointId from the peer’s TLS certificate.

The PublicKey of an endpoint is also known as an EndpointId. This PublicKey is included in the TLS certificate presented during the handshake when connecting. This function allows you to get the EndpointId of the remote endpoint of this connection.

impl Connection<OutgoingZeroRtt>

pub fn alpn(&self) -> Option<Vec<u8>>

Extracts the ALPN protocol from the peer’s handshake data.

pub async fn handshake_completed( &self, ) -> Result<ZeroRttStatus, ConnectingError>

Waits until the full handshake occurs and returns a ZeroRttStatus.

If ZeroRttStatus::Accepted is returned, than any streams created before the handshake has completed can still be used.

If ZeroRttStatus::Rejected is returned, than any streams created before the handshake will error and any data sent should be re-sent on a new stream.

This may fail with ConnectingError::ConnectionError, if there was some general failure with the connection, such as a network timeout since we initiated the connection.

This may fail with ConnectingError::HandshakeFailure, if the other side doesn’t use the right TLS authentication, which usually every iroh endpoint uses and requires.

Thus, those errors should only occur if someone connects to you with a modified iroh endpoint or with a plain QUIC client.

pub fn remote_id(&self) -> Result<PublicKey, RemoteEndpointIdError>

Returns the EndpointId from the peer’s TLS certificate.

The PublicKey of an endpoint is also known as an EndpointId. This PublicKey is included in the TLS certificate presented during the handshake when connecting. This function allows you to get the EndpointId of the remote endpoint of this connection.

Trait Implementations

impl<State> Clone for Connection<State>

where State: Clone + ConnectionState, <State as ConnectionState>::Data: Clone,

fn clone(&self) -> Connection<State>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<State> Debug for Connection<State>

where State: Debug + ConnectionState, <State as ConnectionState>::Data: Debug,

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

Formats the value using the given formatter.