From 4292a500aedd65e6ffac9605f1a1b7c78397a227 Mon Sep 17 00:00:00 2001
From: Quentin McGaw <quentin.mcgaw@gmail.com>
Date: Sat, 10 Jun 2023 20:23:21 +0000
Subject: [PATCH] fix(wireguard): delete existing Wireguard link before adding
 it

---
 internal/wireguard/run.go | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/internal/wireguard/run.go b/internal/wireguard/run.go
index e9095766..0c933a1f 100644
--- a/internal/wireguard/run.go
+++ b/internal/wireguard/run.go
@@ -168,6 +168,23 @@ func setupKernelSpace(ctx context.Context,
 		Name: interfaceName,
 		MTU:  mtu,
 	}
+	links, err := netLinker.LinkList()
+	if err != nil {
+		return link, nil, fmt.Errorf("listing links: %w", err)
+	}
+
+	// Cleanup any previous Wireguard interface with the same name
+	// See https://github.com/qdm12/gluetun/issues/1669
+	for _, link := range links {
+		if link.Type == "wireguard" && link.Name == interfaceName {
+			err = netLinker.LinkDel(link)
+			if err != nil {
+				return link, nil, fmt.Errorf("deleting previous Wireguard link %s: %w",
+					interfaceName, err)
+			}
+		}
+	}
+
 	linkIndex, err := netLinker.LinkAdd(link)
 	if err != nil {
 		return link, nil, fmt.Errorf("%w: %s", ErrAddLink, err)