调整项目结构、尝试支持安卓

switch/src/tun_device/unix.rs

@@ -0,0 +1,37 @@
+use std::io;
+use std::io::{Read, Write};
+
+use bytes::BufMut;
+use tun::platform::posix::{Reader, Writer};
+
+pub struct TunReader(pub(crate) Reader, pub(crate) bool);
+
+impl TunReader {
+    pub fn read<'a>(&'a mut self, buf: &'a mut [u8]) -> io::Result<&mut [u8]> {
+        let len = self.0.read(buf)?;
+        if self.1 {
+            Ok(&mut buf[4..len])
+        } else {
+            Ok(&mut buf[..len])
+        }
+    }
+}
+
+pub struct TunWriter(pub(crate) Writer, pub(crate) bool);
+
+impl TunWriter {
+    pub fn write(&mut self, packet: &[u8]) -> io::Result<()> {
+        if self.1 {
+            let mut buf = Vec::<u8>::with_capacity(4 + packet.len());
+            buf.put_u16(0);
+            #[cfg(any(target_os = "macos", target_os = "ios"))]
+            buf.put_u16(libc::PF_INET as u16);
+            #[cfg(any(target_os = "linux", target_os = "android"))]
+            buf.put_u16(libc::ETH_P_IP as u16);
+            buf.extend_from_slice(packet);
+            self.0.write_all(&buf)
+        } else {
+            self.0.write_all(packet)
+        }
+    }
+}