Struct etherparse::err::LenError

pub struct LenError {
    pub required_len: usize,
    pub len: usize,
    pub len_source: LenSource,
    pub layer: Layer,
    pub layer_start_offset: usize,
}

Error when different lengths are conflicting with each other (e.g. not enough data in a slice to decode a header).

This error is triggered whenever there is not enough data to decode an element (e.g. if a slice is too small to decode an header) or if a length that is inhered from an upper layer is too big for the lower layer (e.g. length inherited from an IP header is too big to be used as an ICMP packet length).

When the error is caused by not enough data being available required_len > len must be true. While when the length from the upper layer is too big for the lower layer the inverse (required_len < len) must be true.

Examples:

An example for an error that could be returned when there is not enough data available to decode an UDP header would be:

use etherparse::*;

err::LenError{
    // Expected to have at least the length of an UDP header present:
    required_len: UdpHeader::LEN,
    // Could not decode the UDP header:
    layer: err::Layer::UdpHeader,
    // There was only 1 byte left (not enough for an UDP header):
    len: 1,
    // The provided length was determined by the total length field in the
    // IPv4 header:
    len_source: LenSource::Ipv4HeaderTotalLen,
    // Offset in bytes from the start of decoding (ethernet in this) case
    // to the expected UDP header start:
    layer_start_offset: Ethernet2Header::LEN + Ipv4Header::MIN_LEN
};

Fields

required_len: usize

Expected minimum or maximum length conflicting with the len value.

len: usize

Length limiting or exceeding the required length.

len_source: LenSource

Source of the outer length (e.g. Slice or a length specified by an upper level protocol).

layer: Layer

Layer in which the length error was encountered.

layer_start_offset: usize

Offset from the start of the parsed data to the layer where the length error occurred.

Implementations

impl LenError

pub const fn add_offset(self, offset: usize) -> Self

Adds an offset value to the layer_start_offset field.

Trait Implementations

impl Clone for LenError

fn clone(&self) -> LenError

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for LenError

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

Formats the value using the given formatter.

impl Display for LenError

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

Formats the value using the given formatter.

impl Error for LenError

Available on crate feature std only.

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

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<LenError> for FromSliceError

fn from(value: LenError) -> Self

Converts to this type from the input type.

impl From<LenError> for ReadError

Available on crate feature std only.

fn from(value: LenError) -> Self

Converts to this type from the input type.

impl Hash for LenError

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for LenError

fn eq(&self, other: &LenError) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for LenError

impl StructuralPartialEq for LenError