Conrad's changes

tun/src/unix/apple/mod.rs

@@ -1,24 +1,24 @@
 use std::{
     io::{Error, IoSlice},
-    mem,
+    mem::{self, ManuallyDrop},
     net::{Ipv4Addr, SocketAddrV4},
-    os::fd::{AsRawFd, RawFd},
+    os::fd::{AsRawFd, FromRawFd, RawFd},
 };
 
 use byteorder::{ByteOrder, NetworkEndian};
 use fehler::throws;
 use libc::{c_char, iovec, writev, AF_INET, AF_INET6};
 use socket2::{Domain, SockAddr, Socket, Type};
-use tracing::{self, debug, instrument};
+use tracing::{self, instrument};
 
-mod kern_control;
+pub mod kern_control;
 pub mod sys;
 
-use crate::retrieve;
 use kern_control::SysControlSocket;
 
 pub use super::queue::TunQueue;
-use super::{ifname_to_string, string_to_ifname, TunOptions};
+use super::{ifname_to_string, string_to_ifname};
+use crate::TunOptions;
 
 #[derive(Debug)]
 pub struct TunInterface {
@@ -35,18 +35,41 @@ impl TunInterface {
     #[throws]
     #[instrument]
     pub fn new_with_options(options: TunOptions) -> TunInterface {
-        debug!("Opening tun interface with options: {:?}", &options);
-        let ti = if let Some(n) = options.seek_utun {
-            retrieve().ok_or(Error::new(std::io::ErrorKind::NotFound, "No utun found"))?
-        } else {
-            TunInterface::connect(0)?
-        };
+        let ti = TunInterface::connect(0)?;
+        ti.configure(options)?;
+        ti
+    }
+
+    pub fn retrieve() -> Option<TunInterface> {
+        (3..100)
+            .filter_map(|fd| unsafe {
+                let peer_addr = socket2::SockAddr::init(|storage, len| {
+                    *len = mem::size_of::<sys::sockaddr_ctl>() as u32;
+                    libc::getpeername(fd, storage as *mut _, len);
+                    Ok(())
+                })
+                .map(|(_, addr)| (fd, addr));
+                peer_addr.ok()
+            })
+            .filter(|(_fd, addr)| {
+                let ctl_addr = unsafe { &*(addr.as_ptr() as *const libc::sockaddr_ctl) };
+                addr.family() == libc::AF_SYSTEM as u8
+                    && ctl_addr.ss_sysaddr == libc::AF_SYS_CONTROL as u16
+            })
+            .map(|(fd, _)| {
+                let socket = unsafe { socket2::Socket::from_raw_fd(fd) };
+                TunInterface { socket }
+            })
+            .next()
+    }
+
+    #[throws]
+    fn configure(&self, options: TunOptions) {
         if let Some(addr) = options.address {
             if let Ok(addr) = addr.parse() {
-                ti.set_ipv4_addr(addr)?;
+                self.set_ipv4_addr(addr)?;
             }
         }
-        ti
     }
 
     #[throws]