Enum CoapError 

pub enum CoapError {
    InvalidMessage(String),
    UnsupportedMethod(String),
    UnsupportedContentFormat(u16),
    BlockTransferError(String),
    DtlsError(String),
    PayloadTooLarge {
        size: usize,
        max: usize,
    },
    ResourceNotFound(String),
    Internal(String),
}

Errors arising from CoAP/EST-coaps protocol handling.

Variants

InvalidMessage(String)

Malformed CoAP message (header, token, or option encoding).

UnsupportedMethod(String)

Unrecognized or unsupported CoAP method code.

UnsupportedContentFormat(u16)

Unrecognized CoAP Content-Format option value.

RFC 9483 §5.4 defines the content-format IDs that EST-coaps supports.

BlockTransferError(String)

Block-wise transfer failure per RFC 7959.

DtlsError(String)

DTLS session establishment or resumption failure.

RFC 9483 §5 requires DTLS to secure all EST-coaps exchanges.

PayloadTooLarge

Payload exceeds the configured maximum size.

Even with block-wise transfer, reassembled payloads are bounded to prevent resource exhaustion on constrained devices.

Fields

size: usize

Actual payload size in bytes.

max: usize

Configured maximum payload size in bytes.

ResourceNotFound(String)

No CoAP resource matches the requested URI path.

Internal(String)

Internal server error (catch-all).

Trait Implementations

impl Clone for CoapError

fn clone(&self) -> CoapError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CoapError

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

Formats the value using the given formatter.

impl Display for CoapError

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

Formats the value using the given formatter.

impl Error for CoapError

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.