From 0b64881c7ac934f3ef8e9c74b815357fbe981ccb Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Sat, 5 May 2018 03:54:55 +0200
Subject: [PATCH] wg-quick: preliminary support for go implementation

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 src/wg-quick.bash | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/wg-quick.bash b/src/wg-quick.bash
index f8c1ce7..cd66b4d 100755
--- a/src/wg-quick.bash
+++ b/src/wg-quick.bash
@@ -83,7 +83,13 @@ auto_su() {
 }
 
 add_if() {
-	cmd ip link add "$INTERFACE" type wireguard
+	local ret
+	if ! cmd ip link add "$INTERFACE" type wireguard; then
+		ret=$?
+		[[ -e /sys/module/wireguard ]] || ! command -v wireguard-go >/dev/null && return $ret
+		echo "[!] Missing WireGuard kernel module. Falling back to slow userspace implementation."
+		cmd wireguard-go "$INTERFACE"
+	fi
 }
 
 del_if() {