Add mqtt lib

Signed-off-by: Thomas Klaehn <thomas.klaehn@perinet.io>

Cargo.toml

@@ -1,7 +1,7 @@
 cargo-features = ["profile-rustflags"]
 
 [workspace]
-members = ["hp-core", "lp-core"]
+members = ["hp-core", "lib/mqtt", "lp-core"]
 resolver = "2"
 
 [profile.release]

lib/mqtt/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "mqtt"
+version = "0.1.0"
+edition = "2024"
+license = "MIT OR Apache-2.0"
+publish = false
+
+[dependencies]
+blocking-network-stack = { git = "https://github.com/bjoernQ/blocking-network-stack.git", rev = "b3ecefc222d8806edd221f266999ca339c52d34e" }
+embedded-io         = { version = "0.6.1", default-features = false }
+mqttrust            = "0.6.0"
+smoltcp             = { version = "0.12.0", default-features = false, features = [ "medium-ethernet", "socket-raw"] }
+
+[features]
+ipv4 = ["smoltcp/proto-ipv4"]
+
+tcp = ["ipv4", "smoltcp/socket-tcp"]

lib/mqtt/src/lib.rs

@@ -0,0 +1,84 @@
+#![no_std]
+
+use blocking_network_stack::IoError;
+use embedded_io::{
+    Read,
+    Write
+};
+use mqttrust::encoding::v4::{
+    encode_slice,
+    Connect,
+    Packet,
+    Protocol,
+    Publish,
+    QoS
+};
+use smoltcp::wire::{
+    IpAddress,
+    Ipv4Address
+};
+
+pub struct Mqtt <'a, 'n, D: smoltcp::phy::Device> {
+    socket: blocking_network_stack::Socket<'a, 'n, D>,
+    address: Ipv4Address,
+    port: u16
+}
+
+impl <'n, 'a: 'n, D: smoltcp::phy::Device> Mqtt<'a, 'a, D> {
+    pub fn new(
+        socket: blocking_network_stack::Socket<'a, 'n, D>,
+        address: Ipv4Address,
+        port: u16
+    ) -> Self {
+        Self {
+            socket,
+            address,
+            port
+        }
+    }
+
+    pub fn open(&mut self) -> Result<(), IoError> {
+        self.socket.open(IpAddress::Ipv4(self.address), self.port)
+    }
+
+    pub fn connect(&mut self, client_id: &str) -> Result<usize, IoError>{
+        let connect = Packet::Connect(Connect {
+            protocol: Protocol::MQTT311,
+            keep_alive: 10,
+            client_id,
+            clean_session: true,
+            last_will: None,
+            username: None,
+            password: None,
+        });
+        let mut buf = [0u8; 1024];
+        let len = encode_slice(&connect, &mut buf).unwrap();
+        self.socket.write(&buf[..len])
+    }
+
+    pub fn publish(&mut self, topic: &str, payload: &[u8]) -> Result<usize, IoError> {
+        let packet = Packet::Publish(Publish {
+            dup: false,
+            qos: QoS::AtMostOnce,
+            pid: None,
+            retain: false,
+            topic_name: topic,
+            payload,
+        });
+        let mut buf = [0u8; 1024];
+        let len = encode_slice(&packet, &mut buf).unwrap();
+        let written = match self.socket.write(&buf[..len]) {
+            Ok(value) => value,
+            Err(err) => return core::prelude::v1::Err(err),
+        };
+        let _ = match self.socket.read(&mut buf) {
+            Ok(value) => value,
+            Err(err) => return core::prelude::v1::Err(err),
+        };
+        Ok(written)
+    }
+
+    pub fn disconnect(&mut self) {
+        self.socket.disconnect();
+    }
+}