Struct L2tpLayer 

pub struct L2tpLayer {
    pub index: LayerIndex,
}

L2TP layer — a zero-copy view into a packet buffer.

Fields

index: LayerIndex

Implementations

impl L2tpLayer

pub fn new(index: LayerIndex) -> Self

Create a new L2TP layer from a layer index.

pub fn at_start() -> Self

Create an L2TP layer starting at offset 0 (for standalone parsing).

pub fn flags_word(&self, buf: &[u8]) -> Result<u16, FieldError>

Read the 2-byte flags+version word.

pub fn flags(&self, buf: &[u8]) -> Result<u16, FieldError>

Get the raw flags byte (high byte of the flags word, bits 0-7).

pub fn version(&self, buf: &[u8]) -> Result<u8, FieldError>

Get the version nibble (bits 12-15 of the flags word; should be 2).

pub fn msg_type(&self, buf: &[u8]) -> Result<u8, FieldError>

Get message type: 0 = data, 1 = control (T bit, bit 15 of word).

pub fn is_control(&self, buf: &[u8]) -> Result<bool, FieldError>

Returns true if the T (type) bit is set (control message).

pub fn has_length(&self, buf: &[u8]) -> Result<bool, FieldError>

Returns true if the L (length) bit is set, meaning Length field is present.

pub fn has_sequence(&self, buf: &[u8]) -> Result<bool, FieldError>

Returns true if the S (sequence) bit is set, meaning Ns and Nr are present.

pub fn has_offset(&self, buf: &[u8]) -> Result<bool, FieldError>

Returns true if the O (offset) bit is set, meaning Offset fields are present.

pub fn length(&self, buf: &[u8]) -> Result<Option<u16>, FieldError>

Get the optional Length field (present when L bit is set).

pub fn tunnel_id(&self, buf: &[u8]) -> Result<u16, FieldError>

Get the Tunnel ID field.

pub fn set_tunnel_id( &self, buf: &mut [u8], value: u16, ) -> Result<(), FieldError>

Set the Tunnel ID field.

pub fn session_id(&self, buf: &[u8]) -> Result<u16, FieldError>

Get the Session ID field.

pub fn set_session_id( &self, buf: &mut [u8], value: u16, ) -> Result<(), FieldError>

Set the Session ID field.

pub fn ns(&self, buf: &[u8]) -> Result<Option<u16>, FieldError>

Get the Ns (send sequence number) field if S bit is set.

pub fn set_ns(&self, buf: &mut [u8], value: u16) -> Result<(), FieldError>

Set the Ns field.

pub fn nr(&self, buf: &[u8]) -> Result<Option<u16>, FieldError>

Get the Nr (receive sequence number) field if S bit is set.

pub fn set_nr(&self, buf: &mut [u8], value: u16) -> Result<(), FieldError>

Set the Nr field.

pub fn summary(&self, buf: &[u8]) -> String

Generate a one-line summary of this L2TP layer.

pub fn field_names() -> &'static [&'static str]

Get the field names for this layer.

pub fn get_field( &self, buf: &[u8], name: &str, ) -> Option<Result<FieldValue, FieldError>>

Get a field value by name.

pub fn set_field( &self, buf: &mut [u8], name: &str, value: FieldValue, ) -> Option<Result<(), FieldError>>

Set a field value by name.

Trait Implementations

impl Clone for L2tpLayer

fn clone(&self) -> L2tpLayer

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for L2tpLayer

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

Formats the value using the given formatter.

impl Layer for L2tpLayer

fn kind(&self) -> LayerKind

Get the kind of this layer

fn summary(&self, data: &[u8]) -> String

Get a human-readable summary of this layer

fn header_len(&self, data: &[u8]) -> usize

Get the header length for this layer

fn field_names(&self) -> &'static [&'static str]

Get the list of field names for this layer

fn hashret(&self, _data: &[u8]) -> Vec<u8>

Compute a hash for packet matching.

fn answers(&self, _data: &[u8], _other: &Self, _other_data: &[u8]) -> bool

Check if this packet answers another packet.

fn extract_padding<'a>(&self, data: &'a [u8]) -> (&'a [u8], &'a [u8])

Extract padding from the packet.