introduce rust

src/udev.rs

@@ -0,0 +1,65 @@
+use eyre::Result;
+use log::error;
+
+pub struct Device {
+    sysname: String,
+    output: String,
+}
+
+impl Device {
+    pub fn sysname(&self) -> &str {
+        self.sysname.as_str()
+    }
+
+    pub fn properties(&self) -> impl Iterator<Item = (&str, &str)> {
+        self.output
+            .lines()
+            .filter_map(|line| line.strip_prefix("E: ")?.split_once('='))
+    }
+}
+
+pub fn get_devices(class: &str) -> Result<Vec<Device>> {
+    let mut devices = Vec::new();
+
+    // none of libudev and udev crates were able to list network devices.
+    // falling back to manual sysfs scanning :(
+    //
+    // Even when given a syspath,
+    // - udev crate failed to see all properties;
+    // - libudev crate segfaulted on the second property (SYSNUM ok, then segfault).
+    // falling back to parsing udevadm output :(
+    //
+    // The best fix would be to check what's wrong with udev crate.
+
+    let entries = std::fs::read_dir(format!("/sys/class/{class}"))?;
+    for entry in entries {
+        let Ok(entry) = entry else {
+            continue;
+        };
+
+        let path = entry.path();
+        let path = path.to_string_lossy();
+
+        let output = std::process::Command::new("udevadm")
+            .args(&["info", &format!("--path={path}")])
+            .stderr(std::process::Stdio::piped())
+            .output()?;
+
+        if !output.status.success() {
+            error!("udevadm fail for {path}");
+            continue;
+        }
+
+        let output = String::from_utf8_lossy(&output.stdout);
+
+        let name = entry.file_name();
+        let dev = Device {
+            sysname: name.to_string_lossy().to_string(),
+            output: output.into_owned(),
+        };
+
+        devices.push(dev);
+    }
+
+    Ok(devices)
+}