GitHub issue #465 - Windows route amnesia

osdep/ManagedRoute.cpp

@@ -346,6 +346,38 @@ static bool _winRoute(bool del,const NET_LUID &interfaceLuid,const NET_IFINDEX &
 	}
 }
 
+static bool _winHasRoute(const NET_LUID &interfaceLuid, const NET_IFINDEX &interfaceIndex, const InetAddress &target, const InetAddress &via)
+{
+	MIB_IPFORWARD_ROW2 rtrow;
+	InitializeIpForwardEntry(&rtrow);
+	rtrow.InterfaceLuid.Value = interfaceLuid.Value;
+	rtrow.InterfaceIndex = interfaceIndex;
+	if (target.ss_family == AF_INET) {
+		rtrow.DestinationPrefix.Prefix.si_family = AF_INET;
+		rtrow.DestinationPrefix.Prefix.Ipv4.sin_family = AF_INET;
+		rtrow.DestinationPrefix.Prefix.Ipv4.sin_addr.S_un.S_addr = reinterpret_cast<const struct sockaddr_in *>(&target)->sin_addr.S_un.S_addr;
+		if (via.ss_family == AF_INET) {
+			rtrow.NextHop.si_family = AF_INET;
+			rtrow.NextHop.Ipv4.sin_family = AF_INET;
+			rtrow.NextHop.Ipv4.sin_addr.S_un.S_addr = reinterpret_cast<const struct sockaddr_in *>(&via)->sin_addr.S_un.S_addr;
+		}
+	} else if (target.ss_family == AF_INET6) {
+		rtrow.DestinationPrefix.Prefix.si_family = AF_INET6;
+		rtrow.DestinationPrefix.Prefix.Ipv6.sin6_family = AF_INET6;
+		memcpy(rtrow.DestinationPrefix.Prefix.Ipv6.sin6_addr.u.Byte, reinterpret_cast<const struct sockaddr_in6 *>(&target)->sin6_addr.u.Byte, 16);
+		if (via.ss_family == AF_INET6) {
+			rtrow.NextHop.si_family = AF_INET6;
+			rtrow.NextHop.Ipv6.sin6_family = AF_INET6;
+			memcpy(rtrow.NextHop.Ipv6.sin6_addr.u.Byte, reinterpret_cast<const struct sockaddr_in6 *>(&via)->sin6_addr.u.Byte, 16);
+		}
+	} else {
+		return false;
+	}
+	rtrow.DestinationPrefix.PrefixLength = target.netmaskBits();
+	rtrow.SitePrefixLength = rtrow.DestinationPrefix.PrefixLength;
+	return (GetIpForwardEntry2(&rtrow) == NO_ERROR);
+}
+
 #endif // __WINDOWS__ --------------------------------------------------------
 
 #ifndef ZT_ROUTING_SUPPORT_FOUND
@@ -463,11 +495,11 @@ bool ManagedRoute::sync()
 
 #ifdef __WINDOWS__ // --------------------------------------------------------
 
-	if (!_applied.count(leftt)) {
+	if ( (!_applied.count(leftt)) || (!_winHasRoute(interfaceLuid,interfaceIndex,leftt,_via)) ) {
 		_applied[leftt] = false; // boolean unused
 		_winRoute(false,interfaceLuid,interfaceIndex,leftt,_via);
 	}
-	if ((rightt)&&(!_applied.count(rightt))) {
+	if ( (rightt) && ( (!_applied.count(rightt)) || (!_winHasRoute(interfaceLuid,interfaceIndex,rightt,_via)) ) ) {
 		_applied[rightt] = false; // boolean unused
 		_winRoute(false,interfaceLuid,interfaceIndex,rightt,_via);
 	}