From 1c8b0eccc788e94a9ff1987948e9af35efc246cd Mon Sep 17 00:00:00 2001
From: Susant Sahani <ssahani@gmail.com>
Date: Wed, 8 May 2019 20:09:42 +0530
Subject: [PATCH] networkd: Assign VXLAN destination port to when GPE is set

When VXLAN destination port is unset and GPE is set
then assign 4790 to destination port. Kernel does the same as
well as iproute.

IANA VXLAN-GPE port is 4790
---
 man/systemd.netdev.xml     | 3 ++-
 src/network/netdev/vxlan.c | 3 +++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/man/systemd.netdev.xml b/man/systemd.netdev.xml
index 7fddedf6e8..fc33f89a38 100644
--- a/man/systemd.netdev.xml
+++ b/man/systemd.netdev.xml
@@ -661,7 +661,8 @@
          <para>Takes a boolean. When true, Generic Protocol Extension extends the existing VXLAN protocol
          to provide protocol typing, OAM, and versioning capabilities. For details about the VXLAN GPE
          Header, see the <ulink url="https://tools.ietf.org/html/draft-ietf-nvo3-vxlan-gpe-07">
-         Generic Protocol Extension for VXLAN </ulink> document. Defaults to false.</para>
+         Generic Protocol Extension for VXLAN </ulink> document. If destination port is not specified and
+         Generic Protocol Extension is set then default port of 4790 is used. Defaults to false.</para>
        </listitem>
     </varlistentry>
     <varlistentry>
diff --git a/src/network/netdev/vxlan.c b/src/network/netdev/vxlan.c
index 86403696a0..56c97cb686 100644
--- a/src/network/netdev/vxlan.c
+++ b/src/network/netdev/vxlan.c
@@ -289,6 +289,9 @@ static int netdev_vxlan_verify(NetDev *netdev, const char *filename) {
                                                 "%s: VXLAN TTL must be <= 255. Ignoring.",
                                                 filename);
 
+        if (!v->dest_port && v->generic_protocol_extension)
+                v->dest_port = 4790;
+
         return 0;
 }