Add a function to find a BLE peripheral

.github/workflows/testing.yml

@@ -29,6 +29,12 @@ jobs:
       - name: Install Rust stable
         uses: dtolnay/rust-toolchain@stable
 
+      - name: Install dependencies (Ubuntu only)
+        if: matrix.platform == 'ubuntu-20.04'
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y libdbus-1-dev pkg-config
+
       - name: Run test suite
         working-directory: ./
         run: cargo test

Cargo.toml

@@ -46,3 +46,5 @@ specta = { git = "https://github.com/ajmcquilkin/specta.git", version = ">= 1.0.
 serde = { version = "1.0", features = ["derive"], optional = true }
 serde_json = { version = "1.0", optional = true }
 thiserror = "1.0.48"
+uuid = "1.6.1"
+btleplug = "0.11.5"

src/errors_internal.rs

@@ -88,6 +88,10 @@ pub enum InternalChannelError {
     IncomingStreamDataWriteError(#[from] tokio::sync::mpsc::error::SendError<IncomingStreamData>),
 }
 
+#[derive(Error, Debug)]
+#[error("Bluetooth low energy connection error")]
+pub struct BleConnectionError();
+
 mod test {
     #[allow(dead_code)]
     fn is_send<T: Send>() {}

src/utils_internal.rs

@@ -1,13 +1,17 @@
+use crate::errors_internal::{BleConnectionError, Error};
+use btleplug::api::{Central, Manager as _, Peripheral as _, ScanFilter};
+use btleplug::platform::{Adapter, Manager, Peripheral};
+use log::error;
 use std::time::Duration;
 use std::time::UNIX_EPOCH;
+use uuid::Uuid;
 
 use rand::{distributions::Standard, prelude::Distribution, Rng};
 use tokio_serial::{available_ports, SerialPort, SerialStream};
 
 use crate::connections::wrappers::encoded_data::{
     EncodedToRadioPacket, EncodedToRadioPacketWithHeader,
 };
-use crate::errors_internal::Error;
 
 // Constants declarations
 
@@ -191,6 +195,54 @@ pub async fn build_tcp_stream(address: String) -> Result<tokio::net::TcpStream,
     Ok(stream)
 }
 
+const MSH_SERVICE: Uuid = Uuid::from_u128(0x6ba1b218_15a8_461f_9fa8_5dcae273eafd);
+
+async fn scan_peripherals(adapter: &Adapter) -> Result<Vec<Peripheral>, btleplug::Error> {
+    adapter
+        .start_scan(ScanFilter {
+            services: vec![MSH_SERVICE],
+        })
+        .await?;
+    adapter.peripherals().await
+}
+
+/// Finds a BLE radio matching a given name and running meshtastic.
+/// It searches for the 'MSH_SERVICE' running on the device.
+async fn find_ble_radio(name: String) -> Result<Peripheral, Error> {
+    //TODO: support searching both by a name and by a MAC address
+    let scan_error_fn = |e: btleplug::Error| Error::StreamBuildError {
+        source: Box::new(e),
+        description: "Failed to scan for BLE devices".to_owned(),
+    };
+    let manager = Manager::new().await.map_err(scan_error_fn)?;
+    let adapters = manager.adapters().await.map_err(scan_error_fn)?;
+
+    for adapter in &adapters {
+        let peripherals = scan_peripherals(&adapter).await;
+        match peripherals {
+            Err(e) => {
+                error!("Error while scanning for meshtastic peripherals: {e:?}");
+                // We continue, as there can be another adapter that can work
+                continue;
+            }
+            Ok(peripherals) => {
+                for peripheral in peripherals {
+                    if let Ok(Some(peripheral_properties)) = peripheral.properties().await {
+                        if peripheral_properties.local_name == Some(name.clone()) {
+                            return Ok(peripheral);
+                        }
+                    }
+                }
+            }
+        }
+    }
+    Err(Error::StreamBuildError {
+        source: Box::new(BleConnectionError()),
+        description: format!("Failed to find {name}, or meshtastic is not running on the device")
+            + ", or it's already connected.",
+    })
+}
+
 /// A helper method to generate random numbers using the `rand` crate.
 ///
 /// This method is intended to be used to generate random id values. This method