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,
    },
}

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 decodes such an Object rather than refusing it — the frame is well formed, and a tool that reports non-conforming traffic has to be able to read it. Being an endpoint rather than an observer is what turns it into an error, so it is raised here, on the receive path, and not in the decoder.

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.

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.

LocalSocket joins InvalidAddress, and that is the answer being kept

A socket this machine would not open has a variant of its own on DialError, and it still arrives here. Not laziness about the churn — InvalidAddress is one of the variants the facade reads as ErrorCause::Facade, which is_local answers true for, and a failed bind is this side’s by definition. Routing it to Transport would read better in prose and would publish this machine’s missing IPv6 stack as the relay’s doing.

The phase is not lost, only unread on this path. A caller measuring which stage of a dial died reads DialError::phase off the dial itself; a caller who arrived at this type named a host:port and asked for a connection, not for a measurement, and a public variant here for a distinction nothing on this path reads is churn with no reader, which is why this impl stays flat.

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.