Enum ConnectionError 

pub enum ConnectionError {
    Endpoint(EndpointError),
    Codec(CodecError),
    Transport(TransportError),
    VarInt(VarIntError),
    NoControlStream,
    UnexpectedEnd,
    StreamFinished,
    InvalidAddress(String),
    TlsConfig(String),
    DataStreamState(&'static str),
    ControlMessageNarrowing,
    NonSubscribeNamespaceOnBidiStream(MessageType),
    NotOursToAnswer(u64),
    ExtensionsOnNonNormalStatus {
        object_id: u64,
        extensions_len: usize,
        status: ObjectStatus,
    },
    EmptyDatagramExtensions {
        object_id: u64,
    },
}

Errors from the connection layer.

Variants

Endpoint(EndpointError)

Endpoint state machine error.

Codec(CodecError)

Wire codec error.

Transport(TransportError)

Transport-level error.

VarInt(VarIntError)

Variable-length integer decoding error.

NoControlStream

Control stream was not opened.

UnexpectedEnd

Stream ended before a complete message was read.

StreamFinished

Stream was finished by the peer.

InvalidAddress(String)

Invalid server address string.

TlsConfig(String)

TLS configuration error.

DataStreamState(&'static str)

Data stream used out of order (e.g. object before header).

ControlMessageNarrowing

A control message this build decoded for draft-16 and then could not narrow to draft-16’s own message type.

Unreachable, and that is not the same as harmless. read_control decodes with this connection’s own draft, so the AnyControlMessage it hands back can only carry this draft’s variant — but the narrowing arm is compiled in every configuration anyway, under #[allow(unreachable_patterns)] rather than a cfg naming the other drafts, because such a list has to be edited in every per-draft module whenever a draft is added and a copy that omits one leaves the match non-exhaustive.

Spelled as CodecError::UnknownMessageType(0) it would not stay inert: every draft’s codec_session_error_code answers that variant Some(PROTOCOL_VIOLATION). So the day the narrowing did fail, this build’s own defect would reach a caller as the peer sent a control message type this draft does not assign, and the session must be closed with a Protocol Violation — carrying 0x00 as the codepoint that proved it. A conformance report reading that publishes a named, well-evidenced accusation against a relay for something no relay did.

A variant of its own is what stops that. draft_specific_cause answers it LocalRefusal, the facade turns that into ErrorCause::Facade, and nothing downstream can read a rule out of a cause that says nothing reached the wire. What is pinned is the consequence rather than the unreachability: nothing pins the arm’s reachability, which is exactly why the consequence must not be an accusation.

NonSubscribeNamespaceOnBidiStream(MessageType)

A bidirectional stream the peer opened began with a message type other than SUBSCRIBE_NAMESPACE.

Draft-16 Section 3.3: “This specification only specifies two uses of bidirectional streams, the control stream, which begins with CLIENT_SETUP, and SUBSCRIBE_NAMESPACE. Bidirectional streams MUST NOT begin with any other message type unless negotiated. If they do, the peer MUST close the Session with a Protocol Violation.” The session has already been closed on the wire by the time this is returned, and the offending stream reset.

NotOursToAnswer(u64)

A respond_* helper was called on a namespace subscription this endpoint opened.

The answer to a SUBSCRIBE_NAMESPACE is owed by whoever received it, so only a stream that arrived through Connection::accept_namespace_stream can be answered here. Nothing was written and no state moved.

ExtensionsOnNonNormalStatus

An Object arrived carrying extension headers on a status that is not Normal. Draft-16 Section 10.2.1.2: “Any Object with status Normal can have extension headers”, with a reference to Section 2.5 inside the sentence, and “If an endpoint receives extension headers on Objects with status that is not Normal, it MUST close the session with a PROTOCOL_VIOLATION.”

The codec’s read_object refuses such an Object as a bare InvalidField. Its read_object_meta frames it, which is how the receive path names the rule here and stays in step with the wire.

Connection::close_for_data_stream performs the close the sentence above requires. It is a separate call because the reader that raises this holds no connection, and because a deliberately permissive caller should be able to read a violating stream and report it without tearing the session down.

Fields

object_id: u64

The Object ID the extension headers arrived on.

extensions_len: usize

Length in bytes of the extension-header block.

status: ObjectStatus

The Object’s status, resolved through the encoding’s elision rule.

Spelled out in full because the glob import of moqtap_codec::types brings a different ObjectStatus into this module.

EmptyDatagramExtensions

A datagram whose Type announces extension headers arrived with an Extension Headers Length of 0.

draft-16 Section 10.3.1: “If an endpoint receives a datagram with the EXTENSIONS bit set and an Extension Headers Length of 0, it MUST close the session with a PROTOCOL_VIOLATION.”

The codec’s header decoder refuses such a datagram as a bare InvalidField. Connection::recv_datagram names it here, and Connection::close_for_data_stream closes the session over it.

Fields

object_id: u64

The Object ID the datagram named.

Trait Implementations

impl Debug for ConnectionError

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

Formats the value using the given formatter.

impl Display for ConnectionError

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

Formats the value using the given formatter.

impl Error for ConnectionError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<CodecError> for ConnectionError

fn from(source: CodecError) -> Self

Converts to this type from the input type.

impl From<ConnectionError> for AnyConnectionError

Available on crate feature draft16 only.

fn from(err: ConnectionError) -> Self

Converts to this type from the input type.

impl From<DialError> for ConnectionError

fn from(e: DialError) -> Self

Maps a dial failure onto the variants this error already has, so a caller matches InvalidAddress or TlsConfig.

A LocalSocket failure maps to InvalidAddress, which the facade reads as this side’s failure (ErrorCause::Facade). The dial phase stays on DialError::phase.

impl From<EndpointError> for ConnectionError

fn from(source: EndpointError) -> Self

Converts to this type from the input type.

impl From<TransportError> for ConnectionError

fn from(source: TransportError) -> Self

Converts to this type from the input type.

impl From<VarIntError> for ConnectionError

fn from(source: VarIntError) -> Self

Converts to this type from the input type.