From ab92306d016344a91fb8088611ed1fcb0d3699a1 Mon Sep 17 00:00:00 2001
From: Ethan <39577870+ethanndickson@users.noreply.github.com>
Date: Tue, 28 Jan 2025 20:47:21 +1100
Subject: [PATCH] fix(vpn): handle sending nil router config (#16267)

Previously, a `nil` Router config would cause a panic in the dylib.
Normally, a nil Router config would indicate a shutdown of the service,
and that settings should be reset. However, for Coder Desktop macOS the
network configuration will be reset by the disconnecting of the system
VPN, so we'll instead do nothing.
---
 vpn/router.go               | 7 +++++--
 vpn/router_internal_test.go | 6 +++---
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/vpn/router.go b/vpn/router.go
index 45998ac954..07cba68d36 100644
--- a/vpn/router.go
+++ b/vpn/router.go
@@ -22,7 +22,10 @@ func (*vpnRouter) Up() error {
 }
 
 func (v *vpnRouter) Set(cfg *router.Config) error {
-	req := convertRouterConfig(cfg)
+	if cfg == nil {
+		return nil
+	}
+	req := convertRouterConfig(*cfg)
 	return v.tunnel.ApplyNetworkSettings(v.tunnel.ctx, req)
 }
 
@@ -31,7 +34,7 @@ func (*vpnRouter) Close() error {
 	return nil
 }
 
-func convertRouterConfig(cfg *router.Config) *NetworkSettingsRequest {
+func convertRouterConfig(cfg router.Config) *NetworkSettingsRequest {
 	v4LocalAddrs := make([]string, 0)
 	v6LocalAddrs := make([]string, 0)
 	for _, addrs := range cfg.LocalAddrs {
diff --git a/vpn/router_internal_test.go b/vpn/router_internal_test.go
index 777b53940e..4f7f6d769a 100644
--- a/vpn/router_internal_test.go
+++ b/vpn/router_internal_test.go
@@ -13,12 +13,12 @@ func TestConvertRouterConfig(t *testing.T) {
 
 	tests := []struct {
 		name     string
-		cfg      *router.Config
+		cfg      router.Config
 		expected *NetworkSettingsRequest
 	}{
 		{
 			name: "IPv4 and IPv6 configuration",
-			cfg: &router.Config{
+			cfg: router.Config{
 				LocalAddrs:  []netip.Prefix{netip.MustParsePrefix("100.64.0.1/32"), netip.MustParsePrefix("fd7a:115c:a1e0::1/128")},
 				Routes:      []netip.Prefix{netip.MustParsePrefix("192.168.0.0/24"), netip.MustParsePrefix("fd00::/64")},
 				LocalRoutes: []netip.Prefix{netip.MustParsePrefix("10.0.0.0/8"), netip.MustParsePrefix("2001:db8::/32")},
@@ -48,7 +48,7 @@ func TestConvertRouterConfig(t *testing.T) {
 		},
 		{
 			name: "Empty",
-			cfg:  &router.Config{},
+			cfg:  router.Config{},
 			expected: &NetworkSettingsRequest{
 				Ipv4Settings: &NetworkSettingsRequest_IPv4Settings{
 					Addrs:          []string{},