From 82ac568ee349992ae4c592ee5d24908a3780be75 Mon Sep 17 00:00:00 2001
From: "Quentin McGaw (desktop)" <quentin.mcgaw@gmail.com>
Date: Sat, 4 Sep 2021 22:29:04 +0000
Subject: [PATCH] Fix: wireguard cleanup preventing restarts

---
 internal/netlink/link.go                   |  5 ++++
 internal/netlink/mock_netlink/interface.go | 14 ++++++++++
 internal/wireguard/cleanup.go              |  8 ++++--
 internal/wireguard/netlinker.go            |  2 ++
 internal/wireguard/netlinker_mock_test.go  | 30 +++++++++++++++++++++-
 internal/wireguard/run.go                  | 12 ++++++---
 6 files changed, 65 insertions(+), 6 deletions(-)

diff --git a/internal/netlink/link.go b/internal/netlink/link.go
index 20f8e1b4..4cde06a5 100644
--- a/internal/netlink/link.go
+++ b/internal/netlink/link.go
@@ -16,6 +16,7 @@ type Linker interface {
 	LinkAdd(link netlink.Link) (err error)
 	LinkDel(link netlink.Link) (err error)
 	LinkSetUp(link netlink.Link) (err error)
+	LinkSetDown(link netlink.Link) (err error)
 }
 
 func (n *NetLink) LinkList() (links []netlink.Link, err error) {
@@ -41,3 +42,7 @@ func (n *NetLink) LinkDel(link netlink.Link) (err error) {
 func (n *NetLink) LinkSetUp(link netlink.Link) (err error) {
 	return netlink.LinkSetUp(link)
 }
+
+func (n *NetLink) LinkSetDown(link netlink.Link) (err error) {
+	return netlink.LinkSetDown(link)
+}
diff --git a/internal/netlink/mock_netlink/interface.go b/internal/netlink/mock_netlink/interface.go
index 4896283c..d96af938 100644
--- a/internal/netlink/mock_netlink/interface.go
+++ b/internal/netlink/mock_netlink/interface.go
@@ -136,6 +136,20 @@ func (mr *MockNetLinkerMockRecorder) LinkList() *gomock.Call {
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "LinkList", reflect.TypeOf((*MockNetLinker)(nil).LinkList))
 }
 
+// LinkSetDown mocks base method.
+func (m *MockNetLinker) LinkSetDown(arg0 netlink.Link) error {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "LinkSetDown", arg0)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+// LinkSetDown indicates an expected call of LinkSetDown.
+func (mr *MockNetLinkerMockRecorder) LinkSetDown(arg0 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "LinkSetDown", reflect.TypeOf((*MockNetLinker)(nil).LinkSetDown), arg0)
+}
+
 // LinkSetUp mocks base method.
 func (m *MockNetLinker) LinkSetUp(arg0 netlink.Link) error {
 	m.ctrl.T.Helper()
diff --git a/internal/wireguard/cleanup.go b/internal/wireguard/cleanup.go
index d567b12e..cfae13a6 100644
--- a/internal/wireguard/cleanup.go
+++ b/internal/wireguard/cleanup.go
@@ -52,8 +52,12 @@ const (
 	stepTwo
 	// stepThree closes the UAPI file.
 	stepThree
-	// stepFour closes the Wireguard device.
+	// stepFour shuts down the Wireguard link.
 	stepFour
-	// stepFive closes the bind connection and the TUN device file.
+	// stepFive removes the Wireguard link.
 	stepFive
+	// stepSix closes the Wireguard device.
+	stepSix
+	// stepSeven closes the bind connection and the TUN device file.
+	stepSeven
 )
diff --git a/internal/wireguard/netlinker.go b/internal/wireguard/netlinker.go
index fe3da2dc..2b4a67f6 100644
--- a/internal/wireguard/netlinker.go
+++ b/internal/wireguard/netlinker.go
@@ -11,4 +11,6 @@ type NetLinker interface {
 	RuleDel(rule *netlink.Rule) error
 	LinkByName(name string) (link netlink.Link, err error)
 	LinkSetUp(link netlink.Link) error
+	LinkSetDown(link netlink.Link) error
+	LinkDel(link netlink.Link) error
 }
diff --git a/internal/wireguard/netlinker_mock_test.go b/internal/wireguard/netlinker_mock_test.go
index 3e18021d..e29f5475 100644
--- a/internal/wireguard/netlinker_mock_test.go
+++ b/internal/wireguard/netlinker_mock_test.go
@@ -8,7 +8,7 @@ import (
 	reflect "reflect"
 
 	gomock "github.com/golang/mock/gomock"
-	netlink "github.com/qdm12/gluetun/internal/netlink"
+	netlink "github.com/vishvananda/netlink"
 )
 
 // MockNetLinker is a mock of NetLinker interface.
@@ -63,6 +63,34 @@ func (mr *MockNetLinkerMockRecorder) LinkByName(arg0 interface{}) *gomock.Call {
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "LinkByName", reflect.TypeOf((*MockNetLinker)(nil).LinkByName), arg0)
 }
 
+// LinkDel mocks base method.
+func (m *MockNetLinker) LinkDel(arg0 netlink.Link) error {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "LinkDel", arg0)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+// LinkDel indicates an expected call of LinkDel.
+func (mr *MockNetLinkerMockRecorder) LinkDel(arg0 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "LinkDel", reflect.TypeOf((*MockNetLinker)(nil).LinkDel), arg0)
+}
+
+// LinkSetDown mocks base method.
+func (m *MockNetLinker) LinkSetDown(arg0 netlink.Link) error {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "LinkSetDown", arg0)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+// LinkSetDown indicates an expected call of LinkSetDown.
+func (mr *MockNetLinkerMockRecorder) LinkSetDown(arg0 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "LinkSetDown", reflect.TypeOf((*MockNetLinker)(nil).LinkSetDown), arg0)
+}
+
 // LinkSetUp mocks base method.
 func (m *MockNetLinker) LinkSetUp(arg0 netlink.Link) error {
 	m.ctrl.T.Helper()
diff --git a/internal/wireguard/run.go b/internal/wireguard/run.go
index 9a3757e6..7c41b3d1 100644
--- a/internal/wireguard/run.go
+++ b/internal/wireguard/run.go
@@ -51,7 +51,7 @@ func (w *Wireguard) Run(ctx context.Context, waitError chan<- error, ready chan<
 		return
 	}
 
-	closers.add("closing TUN device", stepFive, tun.Close)
+	closers.add("closing TUN device", stepSeven, tun.Close)
 
 	tunName, err := tun.Name()
 	if err != nil {
@@ -71,12 +71,12 @@ func (w *Wireguard) Run(ctx context.Context, waitError chan<- error, ready chan<
 
 	bind := conn.NewDefaultBind()
 
-	closers.add("closing bind", stepFive, bind.Close)
+	closers.add("closing bind", stepSeven, bind.Close)
 
 	deviceLogger := makeDeviceLogger(w.logger)
 	device := device.NewDevice(tun, bind, deviceLogger)
 
-	closers.add("closing Wireguard device", stepFour, func() error {
+	closers.add("closing Wireguard device", stepSix, func() error {
 		device.Close()
 		return nil
 	})
@@ -117,6 +117,12 @@ func (w *Wireguard) Run(ctx context.Context, waitError chan<- error, ready chan<
 		waitError <- fmt.Errorf("%w: %s", ErrIfaceUp, err)
 		return
 	}
+	closers.add("shutting down link", stepFour, func() error {
+		return w.netlink.LinkSetDown(link)
+	})
+	closers.add("deleting link", stepFive, func() error {
+		return w.netlink.LinkDel(link)
+	})
 
 	err = w.addRoute(link, allIPv4(), w.settings.FirewallMark)
 	if err != nil {