Detect OS before choosing IpNeighborScanner

main/Cargo.toml

@@ -14,7 +14,7 @@ mockall = "0.12"
 prost = "0.12"
 tansa-protocol = { path = "../protocol/rust" }
 thiserror = "1"
-tokio = "1"
+tokio = { version = "1", features = ["fs"] }
 tokio-stream = { version = "0.1", features = ["net"] }
 tokio-util = { version = "0.7", features = ["codec", "net"]}
 tonic = "0.11"

main/src/lib.rs

@@ -29,6 +29,7 @@
 //!   Usually contains the socket address accessible within the LAN you connect.
 
 mod network;
+mod os;
 mod packet;
 mod response_collector;
 mod response_sender;

main/src/network/link_local/mod.rs

@@ -1,10 +1,22 @@
+use crate::os::OperatingSystem;
 use futures_util::future::BoxFuture;
 use futures_util::FutureExt;
 use mockall::automock;
 use std::net::Ipv6Addr;
 use std::net::SocketAddrV6;
 use thiserror::Error;
 
+pub async fn ip_neighbor_scanner() -> Box<dyn IpNeighborScanner> {
+    match crate::os::detect_operating_system().await {
+        Ok(OperatingSystem::Windows) => Box::new(DummyIpNeighborScanner), // TODO
+        Err(e) => {
+            log::warn!("Failed to detect operating system: {}", e);
+            log::info!("Unknown operating system, disabling IP neighbor discovery.");
+            Box::new(DummyIpNeighborScanner)
+        }
+    }
+}
+
 #[derive(Error, Debug)]
 pub enum IpNeighborScanError {}
 
@@ -13,7 +25,7 @@ pub trait IpNeighborScanner {
     fn scan(&self) -> BoxFuture<'static, Result<Vec<IpNeighbor>, IpNeighborScanError>>;
 }
 
-pub struct DummyIpNeighborScanner;
+struct DummyIpNeighborScanner;
 
 impl IpNeighborScanner for DummyIpNeighborScanner {
     fn scan(&self) -> BoxFuture<'static, Result<Vec<IpNeighbor>, IpNeighborScanError>> {

main/src/os.rs

@@ -0,0 +1,42 @@
+use std::path::PathBuf;
+use thiserror::Error;
+
+#[derive(PartialEq, Eq)]
+pub enum OperatingSystem {
+    Windows,
+}
+
+#[derive(Error, Debug)]
+pub enum OperatingSystemDetectError {
+    #[error("Error in file system")]
+    FileSystem(#[from] std::io::Error),
+
+    #[error("Unknown operating system")]
+    UnknownOperatingSystem,
+}
+
+pub async fn detect_operating_system() -> Result<OperatingSystem, OperatingSystemDetectError> {
+    if is_file(&[r"C:\", "Windows", "System32", "ntoskrnl.exe"]).await? {
+        return Ok(OperatingSystem::Windows);
+    }
+    if is_file(&["/", "usr", "bin", "systemctl"]).await? {
+        return Ok(OperatingSystem::Windows);
+    }
+
+    Err(OperatingSystemDetectError::UnknownOperatingSystem)
+}
+
+async fn is_file(path: &[&'static str]) -> std::io::Result<bool> {
+    let path_buf: PathBuf = path.iter().collect();
+    Ok(tokio::fs::try_exists(&path_buf).await? && tokio::fs::metadata(&path_buf).await?.is_file())
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[tokio::test]
+    async fn can_detect() {
+        detect_operating_system().await.expect("OS must be known");
+    }
+}

main/src/server.rs

@@ -1,4 +1,3 @@
-use crate::network::link_local::DummyIpNeighborScanner;
 use crate::network::link_local::IpNeighbor;
 use crate::network::link_local::IpNeighborScanError;
 use crate::network::link_local::IpNeighborScanner;
@@ -39,7 +38,7 @@ pub async fn serve(discovery_port: u16, service_port: u16) -> Result<(), ServeEr
         TokioMulticastReceiver,
         GrpcResponseSender,
         TokioUdpSender,
-        Box::new(DummyIpNeighborScanner),
+        crate::network::link_local::ip_neighbor_scanner().await,
     )
     .await
 }