From 4112fb9cd77a6eb2738f97287f99a23809d5c85d Mon Sep 17 00:00:00 2001
From: Matthew Ellison <matt@arroyonetworks.com>
Date: Mon, 22 May 2017 12:00:06 -0400
Subject: [PATCH] darwin: Adds Check Empty Writes to TUN

---
 syscalls_darwin.go | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/syscalls_darwin.go b/syscalls_darwin.go
index 3bdbc50..6a473f8 100644
--- a/syscalls_darwin.go
+++ b/syscalls_darwin.go
@@ -151,6 +151,11 @@ func (t *tunReadCloser) Read(to []byte) (int, error) {
 }
 
 func (t *tunReadCloser) Write(from []byte) (int, error) {
+
+	if len(from) == 0 {
+		return 0, syscall.EIO
+	}
+
 	t.wMu.Lock()
 	defer t.wMu.Unlock()