Add macOS utun support

Signed-off-by: Emīls <[email protected]>

Author: pinkisemils

Cargo.lock

@@ -37,6 +37,10 @@ version = "0.5.0"
 [target.'cfg(unix)'.dependencies]
 libc = "^0.2"
 
+[target.'cfg(target_os = "macos")'.dependencies]
+ioctl-sys = "0.6"
+page_size = "0.4"
+
 [dependencies.x25519-dalek]
 version = "^1.1"
 

Cargo.toml

@@ -2,6 +2,11 @@
 
 extern crate alloc;
 
+#[cfg(target_os = "macos")]
+extern crate ioctl_sys;
+#[cfg(target_os = "macos")]
+extern crate page_size;
+
 #[cfg(feature = "profiler")]
 extern crate cpuprofiler;
 

src/main.rs

@@ -0,0 +1,44 @@
+use std::{io, os::unix::io::RawFd, sync::Arc};
+
+struct FdInner {
+    fd: RawFd,
+}
+
+impl Drop for FdInner {
+    fn drop(&mut self) {
+        unsafe { libc::close(self.fd) };
+    }
+}
+
+#[derive(Clone)]
+pub(super) struct Fd {
+    fd: Arc<FdInner>,
+}
+
+impl Fd {
+    pub fn new(fd: RawFd) -> Self {
+        Self {
+            fd: Arc::new(FdInner { fd }),
+        }
+    }
+
+    pub unsafe fn raw_fd(&self) -> RawFd {
+        self.fd.fd
+    }
+
+    pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
+        let bytes_read = unsafe { libc::write(self.raw_fd(), buf.as_ptr() as _, buf.len()) };
+        if bytes_read < 0 {
+            return Err(io::Error::from_raw_os_error(-bytes_read as i32));
+        }
+        Ok(bytes_read as usize)
+    }
+
+    pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> {
+        let bytes_written = unsafe { libc::read(self.raw_fd(), buf.as_mut_ptr() as _, buf.len()) };
+        if bytes_written < 0 {
+            return Err(io::Error::last_os_error());
+        }
+        Ok(bytes_written as usize)
+    }
+}

src/platform/macos/fd.rs

@@ -0,0 +1,6 @@
+mod fd;
+mod sys;
+mod tun;
+
+pub use crate::platform::unix::uapi::UnixUAPI as UAPI;
+pub use tun::MacosTun as Tun;

src/platform/macos/mod.rs

@@ -0,0 +1,38 @@
+#![allow(non_camel_case_types)]
+#[repr(C)]
+pub struct ctl_info {
+    pub ctl_id: u32,
+    pub ctl_name: [u8; 96],
+}
+ioctl_sys::ioctl!(readwrite ctliocginfo with 'N', 3; ctl_info);
+
+#[repr(C)]
+pub struct rt_msghdr {
+    pub rtm_msglen: u16,
+    pub rtm_version: u8,
+    pub rtm_type: u8,
+    pub rtm_index: u16,
+    pub rtm_flags: i32,
+    pub rtm_addrs: i32,
+    pub rtm_pid: libc::pid_t,
+    pub rtm_seq: i32,
+    pub rtm_errno: i32,
+    pub rtm_use: i32,
+    pub rtm_inits: u32,
+    pub rtm_rmx: rt_metrics,
+}
+
+#[repr(C)]
+pub struct rt_metrics {
+    pub rmx_locks: u32,       /* Kernel must leave these values alone */
+    pub rmx_mtu: u32,         /* MTU for this path */
+    pub rmx_hopcount: u32,    /* max hops expected */
+    pub rmx_expire: i32,      /* lifetime for route, e.g. redirect */
+    pub rmx_recvpipe: u32,    /* inbound delay-bandwidth product */
+    pub rmx_sendpipe: u32,    /* outbound delay-bandwidth product */
+    pub rmx_ssthresh: u32,    /* outbound gateway buffer limit */
+    pub rmx_rtt: u32,         /* estimated round trip time */
+    pub rmx_rttvar: u32,      /* estimated rtt variance */
+    pub rmx_pksent: u32,      /* packets sent using this route */
+    pub rmx_filler: [u32; 4], /* will be used for T/TCP later */
+}