Initial commit

tun/src/apple/mod.rs

@@ -0,0 +1,90 @@
+use socket2::SockAddr;
+use std::io::Result;
+use std::os::unix::io::{AsRawFd, IntoRawFd, RawFd};
+
+mod kern_control;
+mod queue;
+
+pub use queue::TunQueue;
+
+use crate::syscall;
+use crate::unix::copy_if_name;
+use kern_control::SysControlSocket;
+
+pub struct TunInterface {
+    socket: socket2::Socket,
+}
+
+impl TunInterface {
+    pub fn new() -> Result<TunInterface> {
+        TunInterface::connect(None)
+    }
+
+    fn connect(addr: Option<SockAddr>) -> Result<TunInterface> {
+        use socket2::{Domain, Protocol, Socket, Type};
+
+        let socket = Socket::new(
+            Domain::from(libc::AF_SYSTEM),
+            Type::DGRAM,
+            Some(Protocol::from(libc::SYSPROTO_CONTROL)),
+        )?;
+        let addr = match addr {
+            Some(addr) => addr,
+            None => socket.resolve(sys::UTUN_CONTROL_NAME, 0)?,
+        };
+        socket.connect(&addr)?;
+
+        Ok(TunInterface { socket })
+    }
+
+    pub fn name(&self) -> Result<String> {
+        let mut buf = [0u8; libc::IFNAMSIZ];
+        let mut len = buf.len() as libc::socklen_t;
+        syscall!(getsockopt(
+            self.as_raw_fd(),
+            libc::SYSPROTO_CONTROL,
+            sys::UTUN_OPT_IFNAME,
+            buf.as_mut_ptr() as *mut libc::c_void,
+            &mut len,
+        ))?;
+        let name = copy_if_name(buf);
+        Ok(name)
+    }
+
+    pub fn queue(&self) -> Result<TunQueue> {
+        todo!()
+    }
+}
+
+impl AsRawFd for TunInterface {
+    fn as_raw_fd(&self) -> RawFd {
+        self.socket.as_raw_fd()
+    }
+}
+
+impl IntoRawFd for TunInterface {
+    fn into_raw_fd(self) -> RawFd {
+        self.socket.into_raw_fd()
+    }
+}
+
+mod sys {
+    pub const UTUN_CONTROL_NAME: &str = "com.apple.net.utun_control";
+
+    pub const UTUN_OPT_IFNAME: libc::c_int = 2;
+
+    /// Copied from https://github.com/rust-lang/socket2/blob/61314a231f73964b3db969ef72c0e9479df320f3/src/sys/unix.rs#L168-L178
+    /// getsockopt is not exposed by socket2
+    #[macro_export]
+    macro_rules! syscall {
+    ($fn: ident ( $($arg: expr),* $(,)* ) ) => {{
+        #[allow(unused_unsafe)]
+        let res = unsafe { libc::$fn($($arg, )*) };
+        if res == -1 {
+            Err(std::io::Error::last_os_error())
+        } else {
+            Ok(res)
+        }
+    }};
+    }
+}