Kit: Adapter: iterate through all FDs to find UTUN

This is a bit of a kludge, until I find something better. We simply
iterate through all FDs, and call getsockopt on each one until we find
the utun FD. This works, and completes rather quickly (fd is usually 6
or 7). Rather than maintain the old path for older kernels, just use
this for all versions, to get more coverage. Other techniques involve
undocumented APIs; this one has the advantage of using nothing
undocumented.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This commit is contained in:
Jason A. Donenfeld 2021-06-16 15:56:21 +02:00
parent 820fa55380
commit 7f5ad3e503
1 changed files with 8 additions and 1 deletions

View File

@ -57,7 +57,14 @@ public class WireGuardAdapter {
/// Tunnel device file descriptor. /// Tunnel device file descriptor.
private var tunnelFileDescriptor: Int32? { private var tunnelFileDescriptor: Int32? {
return self.packetTunnelProvider?.packetFlow.value(forKeyPath: "socket.fileDescriptor") as? Int32 var buf = [CChar](repeating: 0, count: Int(IFNAMSIZ))
for fd: Int32 in 0...1024 {
var len = socklen_t(buf.count)
if getsockopt(fd, SYSPROTO_CONTROL, 2, &buf, &len) == 0 && String(cString: buf).hasPrefix("utun") {
return fd
}
}
return nil
} }
/// Returns a WireGuard version. /// Returns a WireGuard version.