From ae48a1721e665c7cc4213cca7d93748301bd702f Mon Sep 17 00:00:00 2001
From: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Wed, 5 Dec 2018 23:10:50 +0000
Subject: [PATCH] Try to SO_REUSEADDR on Windows

---
 src/yggdrasil/multicast_other.go   |  2 +-
 src/yggdrasil/multicast_windows.go | 22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100644 src/yggdrasil/multicast_windows.go

diff --git a/src/yggdrasil/multicast_other.go b/src/yggdrasil/multicast_other.go
index 98fe2df1..8a4ce56c 100644
--- a/src/yggdrasil/multicast_other.go
+++ b/src/yggdrasil/multicast_other.go
@@ -1,4 +1,4 @@
-// +build !linux,!darwin,!netbsd,!freebsd,!openbsd,!dragonflybsd
+// +build !linux,!darwin,!netbsd,!freebsd,!openbsd,!dragonflybsd,!windows
 
 package yggdrasil
 
diff --git a/src/yggdrasil/multicast_windows.go b/src/yggdrasil/multicast_windows.go
new file mode 100644
index 00000000..13f20315
--- /dev/null
+++ b/src/yggdrasil/multicast_windows.go
@@ -0,0 +1,22 @@
+// +build windows
+
+package yggdrasil
+
+import "syscall"
+import "golang.org/x/sys/windows"
+
+func multicastReuse(network string, address string, c syscall.RawConn) error {
+	var control error
+	var reuseaddr error
+
+	control = c.Control(func(fd uintptr) {
+		reuseaddr = windows.SetsockoptInt(windows.Handle(fd), windows.SOL_SOCKET, windows.SO_REUSEADDR, 1)
+	})
+
+	switch {
+	case reuseaddr != nil:
+		return reuseaddr
+	default:
+		return control
+	}
+}