Added if_nametoindex (and necessary module based on Cs net/if.h)

src/lib.rs

@@ -31,6 +31,9 @@ pub mod mount;
 #[cfg(any(target_os = "linux"))]
 pub mod mqueue;
 
+#[cfg(any(target_os = "linux"))]
+pub mod net;
+
 #[cfg(any(target_os = "linux", target_os = "android"))]
 pub mod sched;
 

src/net/if_.rs

@@ -0,0 +1,48 @@
+//! Network interface name resolution.
+//!
+//! Uses Linux and/or POSIX functions to resolve interface names like "eth0"
+//! or "socan1" into device numbers.
+
+use libc::{c_char, c_uint};
+use std::ffi::{CString, NulError};
+use std::io;
+
+/// Error that can occur during interface name resolution.
+#[derive(Debug)]
+pub enum NameToIndexError {
+    /// Failed to allocate a C-style string to for the syscall
+    NulError,
+    IOError(io::Error),
+}
+
+impl From<NulError> for NameToIndexError {
+    fn from(_: NulError) -> NameToIndexError {
+        NameToIndexError::NulError
+    }
+}
+
+impl From<io::Error> for NameToIndexError {
+    fn from(e: io::Error) -> NameToIndexError {
+        NameToIndexError::IOError(e)
+    }
+}
+
+extern {
+    fn if_nametoindex(ifname: *const c_char) -> c_uint;
+}
+
+/// Resolve an interface into a interface number.
+pub fn name_to_index(name: &str) -> Result<c_uint, NameToIndexError> {
+    let name = try!(CString::new(name));
+
+    let if_index;
+    unsafe {
+        if_index = if_nametoindex(name.as_ptr());
+    }
+
+    if if_index == 0 {
+        return Err(NameToIndexError::from(io::Error::last_os_error()));
+    }
+
+    Ok(if_index)
+}

src/net/mod.rs

@@ -0,0 +1 @@
+pub mod if_;