From 4365b4583fa32b1b77d33f5074da9c165a28f824 Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Thu, 24 May 2018 18:00:45 +0200
Subject: [PATCH] Trick for being extra sensitive to route changes

---
 conn_linux.go | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/conn_linux.go b/conn_linux.go
index bde4416..396c403 100644
--- a/conn_linux.go
+++ b/conn_linux.go
@@ -58,11 +58,12 @@ func (endpoint *NativeEndpoint) dst6() *unix.SockaddrInet6 {
 }
 
 type NativeBind struct {
-	sock4         int
-	sock6         int
-	netlinkSock   int
-	netlinkCancel *rwcancel.RWCancel
-	lastMark      uint32
+	sock4                        int
+	sock6                        int
+	netlinkSock                  int
+	netlinkCancel                *rwcancel.RWCancel
+	lastMark                     uint32
+	clearSourceOnAllRouteChanges bool
 }
 
 var _ Endpoint = (*NativeEndpoint)(nil)
@@ -582,6 +583,16 @@ func (bind *NativeBind) routineRouteListener(device *Device) {
 
 			switch hdr.Type {
 			case unix.RTM_NEWROUTE, unix.RTM_DELROUTE:
+				if bind.clearSourceOnAllRouteChanges {
+					for _, peer := range device.peers.keyMap {
+						peer.mutex.Lock()
+						if peer.endpoint != nil && peer.endpoint.(*NativeEndpoint) != nil {
+							peer.endpoint.(*NativeEndpoint).ClearSrc()
+						}
+						peer.mutex.Unlock()
+					}
+					break
+				}
 				if hdr.Seq <= MaxPeers && hdr.Seq > 0 {
 					if uint(len(remain)) < uint(hdr.Len) {
 						break