new lan discovery https://github.com/rustdesk/rustdesk/issues/261

libs/hbb_common/src/config.rs

@@ -754,6 +754,40 @@ impl Fav {
     }
 }
 
+#[derive(Debug, Default, Serialize, Deserialize, Clone)]
+pub struct LanPeers {
+    #[serde(default)]
+    pub peers: String,
+}
+
+impl LanPeers {
+    pub fn load() -> LanPeers {
+        let _ = CONFIG.read().unwrap(); // for lock
+        match confy::load_path(&Config::file_("_lan_peers")) {
+            Ok(peers) => peers,
+            Err(err) => {
+                log::error!("Failed to load lan peers: {}", err);
+                Default::default()
+            }
+        }
+    }
+
+    pub fn store(peers: String) {
+        let f = LanPeers { peers };
+        if let Err(err) = confy::store_path(Config::file_("_lan_peers"), f) {
+            log::error!("Failed to store lan peers: {}", err);
+        }
+    }
+
+    pub fn modify_time() -> crate::ResultType<u64> {
+        let p = Config::file_("_lan_peers");
+        Ok(fs::metadata(p)?
+            .modified()?
+            .duration_since(SystemTime::UNIX_EPOCH)?
+            .as_millis() as _)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

libs/hbb_common/src/udp.rs

@@ -4,7 +4,7 @@ use bytes::{Bytes, BytesMut};
 use futures::{SinkExt, StreamExt};
 use protobuf::Message;
 use socket2::{Domain, Protocol, Socket, Type};
-use std::net::{SocketAddr, SocketAddrV4};
+use std::net::{Ipv4Addr, SocketAddr, SocketAddrV4};
 use tokio::net::{ToSocketAddrs, UdpSocket};
 use tokio_socks::{udp::Socks5UdpFramed, IntoTargetAddr, TargetAddr, ToProxyAddrs};
 use tokio_util::{codec::BytesCodec, udp::UdpFramed};
@@ -145,13 +145,26 @@ impl FramedSocket {
 
 // const DEFAULT_MULTICAST: &str = "239.255.42.98";
 
-pub fn bind_multicast(addr: &SocketAddrV4, multi_addr: &SocketAddrV4) -> ResultType<FramedSocket> {
-    assert!(multi_addr.ip().is_multicast(), "Must be multcast address");
+pub fn bind_multicast(maddr: Option<SocketAddrV4>) -> ResultType<FramedSocket> {
+    // todo: https://github.com/bltavares/multicast-socket
+    // 0.0.0.0 bind to default interface, if there are two interfaces, there will be problem.
     let socket = Socket::new(Domain::ipv4(), Type::dgram(), Some(Protocol::udp()))?;
     socket.set_reuse_address(true)?;
-    socket.bind(&socket2::SockAddr::from(*addr))?;
-    socket.set_multicast_loop_v4(true)?;
-    socket.join_multicast_v4(multi_addr.ip(), addr.ip())?;
+    // somehow without this, timer.tick() under tokio::select! does not work
+    socket.set_read_timeout(Some(std::time::Duration::from_millis(100)))?;
+    if let Some(maddr) = maddr {
+        assert!(maddr.ip().is_multicast(), "Must be multcast address");
+        let addr = SocketAddrV4::new(Ipv4Addr::new(0, 0, 0, 0).into(), maddr.port());
+        socket.join_multicast_v4(maddr.ip(), addr.ip())?;
+        socket.set_multicast_loop_v4(true)?;
+        socket.bind(&socket2::SockAddr::from(addr))?;
+    } else {
+        socket.set_multicast_if_v4(&Ipv4Addr::new(0, 0, 0, 0))?;
+        socket.bind(&socket2::SockAddr::from(SocketAddr::new(
+            Ipv4Addr::new(0, 0, 0, 0).into(),
+            0,
+        )))?;
+    }
     Ok(FramedSocket::Direct(UdpFramed::new(
         UdpSocket::from_std(socket.into_udp_socket())?,
         BytesCodec::new(),