Struct MqttLayer 

pub struct MqttLayer {
    pub index: LayerIndex,
}

MQTT layer – a zero-copy view into a packet buffer.

Fields

index: LayerIndex

Implementations

impl MqttLayer

pub fn new(index: LayerIndex) -> Self

Create a new MQTT layer from a layer index.

pub fn at_start(len: usize) -> Self

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

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

Get the message type (bits 7-4 of byte 0).

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

Get the DUP flag (bit 3 of byte 0).

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

Get the QoS level (bits 2-1 of byte 0).

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

Get the RETAIN flag (bit 0 of byte 0).

pub fn remaining_length(&self, buf: &[u8]) -> Result<u32, FieldError>

Get the remaining length (variable-length integer starting at byte 1).

pub fn fixed_header_len(&self, buf: &[u8]) -> usize

Compute the fixed header length (1 byte type/flags + N bytes remaining length).

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

Get the topic length for a PUBLISH message (2-byte big-endian at variable header start).

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

Get the topic string for a PUBLISH message.

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

Get the message ID for PUBLISH (QoS > 0), PUBACK, PUBREC, PUBREL, PUBCOMP, SUBSCRIBE, SUBACK, UNSUBSCRIBE, UNSUBACK messages.

For PUBLISH: message ID follows the topic (2 bytes topic_len + topic bytes). For others: message ID is at the start of the variable header.

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

Get the payload value for a PUBLISH message (bytes after topic + optional msgid).

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

Get the protocol name from a CONNECT message (e.g., “MQTT” or “MQIsdp”).

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

Get the protocol level/version byte from a CONNECT message.

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

Get the connect flags byte from a CONNECT message.

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

Get the username flag from CONNECT flags (bit 7).

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

Get the password flag from CONNECT flags (bit 6).

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

Get the will retain flag from CONNECT flags (bit 5).

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

Get the will QoS from CONNECT flags (bits 4-3).

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

Get the will flag from CONNECT flags (bit 2).

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

Get the clean session flag from CONNECT flags (bit 1).

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

Get the keep alive value from a CONNECT message (2-byte big-endian).

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

Get the client ID from a CONNECT message.

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

Get the session present flag from a CONNACK message (byte 0 of variable header).

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

Get the return code from a CONNACK message (byte 1 of variable header).

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

Get the return codes from a SUBACK message (bytes after the 2-byte msgid).

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

Generate a one-line summary of this MQTT 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 (limited support for MQTT).

Trait Implementations

impl Clone for MqttLayer

fn clone(&self) -> MqttLayer

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MqttLayer

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

Formats the value using the given formatter.

impl From<MqttLayer> for LayerEnum

fn from(v: MqttLayer) -> LayerEnum

Converts to this type from the input type.

impl Layer for MqttLayer

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.

impl LayerDispatch for MqttLayer

fn dispatch_kind(&self) -> LayerKind

Get the kind of this layer.

fn dispatch_index(&self) -> &LayerIndex

Get the layer index (start/end offsets).

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

Get a human-readable summary.

fn dispatch_header_len(&self, buf: &[u8]) -> usize

Get the header length in bytes.

fn dispatch_hashret(&self, buf: &[u8]) -> Vec<u8>

Compute a hash for packet matching.

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

Get field names for this layer type.

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

Get a field value by name.

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

Set a field value by name.

fn dispatch_show_fields(&self, buf: &[u8]) -> Vec<(&'static str, String)>

Get show-fields output.

impl TryInto<MqttLayer> for LayerEnum

type Error = &'static str

The type returned in the event of a conversion error.

fn try_into(self) -> Result<MqttLayer, <Self as TryInto<MqttLayer>>::Error>

Performs the conversion.