version: stop using go version tags in repo

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/version/protocol.go b/version/protocol.go
new file mode 100644
index 00000000..72a35e95
--- /dev/null
+++ b/version/protocol.go
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019-2021 WireGuard LLC. All Rights Reserved.
+ */
+
+package version
+
+import (
+	"runtime/debug"
+	"strings"
+)
+
+func ProtoImplementation() string {
+	info, ok := debug.ReadBuildInfo()
+	if !ok {
+		return "unknown"
+	}
+	for _, dep := range info.Deps {
+		if dep.Path == "golang.zx2c4.com/wireguard" {
+			parts := strings.Split(dep.Version, "-")
+			if len(parts) == 3 && len(parts[2]) == 12 {
+				return parts[2][:7]
+			}
+			return dep.Version
+		}
+	}
+	return "unknown"
+}