Crate mqtt_proto 

MQTT wire protocol: packet encoding/decoding for both MQTT 3.1.1 and MQTT 5.0.

This crate has no networking, async or TLS dependencies: it is a pure, synchronous codec so it can be unit-tested byte-for-byte and reused by the stem-mqtt-client connection loop, the stem-mqtt-broker, and firmware on embedded targets that bring their own transport.

Re-exports

pub use error::MqttError;

pub use error::MqttResult;

pub use ack::*;

pub use connect::*;

pub use packet::*;

pub use properties::*;

pub use publish::*;

pub use subscribe::*;

Modules

ack

PUBACK / PUBREC / PUBREL / PUBCOMP packets. All four share an identical wire shape (MQTT-5.0 §3.4, §3.5, §3.6, §3.7): a packet id, and — in MQTT 5.0, when there’s anything interesting to say — a reason code and properties.

connect

CONNECT / CONNACK packets (MQTT-3.1.1 §3.1, §3.2; MQTT-5.0 §3.1, §3.2).

error

Error type shared by the codec, the client and the broker.

packet

Top-level Packet enum: the fixed header, remaining-length framing, and dispatch to each packet type’s body codec.

properties

MQTT 5.0 Properties (MQTT-5.0 §2.2.2). Absent entirely in MQTT 3.1.1.

publish

PUBLISH packet (MQTT-3.1.1 §3.3; MQTT-5.0 §3.3).

subscribe

SUBSCRIBE / SUBACK / UNSUBSCRIBE / UNSUBACK packets (MQTT-3.1.1 §3.8-§3.11; MQTT-5.0 §3.8-§3.11).

support

Debug helpers that never print passwords or private keys (so a stray {:?} or tracing::debug!(?options) cannot leak credentials into logs). Re-exported by stem-mqtt-client under its support module.

topic

MQTT topic name / topic filter matching and validation (MQTT-3.1.1 §4.7; MQTT-5.0 §4.7), including the + (single-level) and # (multi-level) wildcards and the $-prefixed “system topic” exclusion rule.

varint

Wire-format primitives shared by every MQTT packet: the Variable Byte Integer encoding, length-prefixed UTF-8 strings, and length-prefixed binary data, as defined by the MQTT 3.1.1 and MQTT 5.0 specifications.

Macros

redacted_debug

Implements Debug for a struct, printing the listed fields normally and the secret fields as <redacted>.

Enums

MqttVersion

The MQTT protocol version negotiated for a connection.

QoS

MQTT Quality of Service level.