proxy: improve interface binding (by setsockopt) on linux

proxy/bind_linux.go

@@ -0,0 +1,14 @@
+package proxy
+
+import (
+	"net"
+	"syscall"
+)
+
+func bind(dialer *net.Dialer, iface *net.Interface) {
+	dialer.Control = func(network, address string, c syscall.RawConn) error {
+		return c.Control(func(fd uintptr) {
+			syscall.BindToDevice(int(fd), iface.Name)
+		})
+	}
+}

proxy/bind_others.go

@@ -0,0 +1,8 @@
+//go:build !linux
+// +build !linux
+
+package proxy
+
+import "net"
+
+func bind(dialer *net.Dialer, iface *net.Interface) {}

proxy/direct.go

@@ -33,9 +33,6 @@ func NewDirect(intface string, dialTimeout, relayTimeout time.Duration) (*Direct
 				return nil, errors.New(err.Error() + ": " + intface)
 			}
 			d.iface = iface
-			if ips := d.IFaceIPs(); len(ips) > 0 {
-				d.ip = ips[0]
-			}
 		}
 	}
 
@@ -88,6 +85,10 @@ func (d *Direct) dial(network, addr string, localIP net.IP) (net.Conn, error) {
 	}
 
 	dialer := &net.Dialer{LocalAddr: la, Timeout: d.dialTimeout}
+	if d.iface != nil {
+		bind(dialer, d.iface)
+	}
+
 	c, err := dialer.Dial(network, addr)
 	if err != nil {
 		return nil, err

proxy/vmess/chunk.go

@@ -47,7 +47,7 @@ type chunkedReader struct {
 
 // ChunkedReader returns a chunked reader.
 func ChunkedReader(r io.Reader, chunkSizeDecoder ChunkSizeDecoder) io.Reader {
-	return &chunkedReader{Reader: r, chunkSizeDecoder: chunkSizeDecoder}
+	return &chunkedReader{Reader: r, chunkSizeDecoder: chunkSizeDecoder, buf: make([]byte, chunkSizeDecoder.SizeBytes())}
 }
 
 func (r *chunkedReader) Read(p []byte) (int, error) {