lib, zebra: Allow the specification of BUM flooding

Allow the modification of whether or not we will allow
BUM flooding on the vxlan bridge.  To do this allow
the upper level protocol to specify via the ZEBRA_VXLAN_FLOOD_CONTROL
zapi message.

If flooding is disabled then BUM traffic will not be forwarded
to other VTEP's.

Signed-off-by: Vivek Venkatraman <vivek@cumulusnetworks.com>
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

1 files changed, 75 insertions, 3 deletions

diff --git a/zebra/zebra_vxlan.c b/zebra/zebra_vxlan.c
index f8417503ef..5078eff590 100644
--- a/zebra/zebra_vxlan.c
+++ b/zebra/zebra_vxlan.c
@@ -3097,7 +3097,9 @@ static int zvni_vtep_del_all(zebra_vni_t *zvni, int uninstall)
  */
 static int zvni_vtep_install(zebra_vni_t *zvni, struct in_addr *vtep_ip)
 {
-	return kernel_add_vtep(zvni->vni, zvni->vxlan_if, vtep_ip);
+	if (is_vxlan_flooding_head_end())
+		return kernel_add_vtep(zvni->vni, zvni->vxlan_if, vtep_ip);
+	return 0;
 }
 
 /*
@@ -3115,6 +3117,28 @@ static int zvni_vtep_uninstall(zebra_vni_t *zvni, struct in_addr *vtep_ip)
 }
 
 /*
+ * Install or uninstall flood entries in the kernel corresponding to
+ * remote VTEPs. This is invoked upon change to BUM handling.
+ */
+static void zvni_handle_flooding_remote_vteps(struct hash_backet *backet,
+					      void *zvrf)
+{
+	zebra_vni_t *zvni;
+	zebra_vtep_t *zvtep;
+
+	zvni = (zebra_vni_t *)backet->data;
+	if (!zvni)
+		return;
+
+	for (zvtep = zvni->vteps; zvtep; zvtep = zvtep->next) {
+		if (is_vxlan_flooding_head_end())
+			zvni_vtep_install(zvni, &zvtep->vtep_ip);
+		else
+			zvni_vtep_uninstall(zvni, &zvtep->vtep_ip);
+	}
+}
+
+/*
  * Cleanup VNI/VTEP and update kernel
  */
 static void zvni_cleanup_all(struct hash_backet *backet, void *arg)
@@ -6898,6 +6922,46 @@ int zebra_vxlan_vrf_delete(struct zebra_vrf *zvrf)
 }
 
 /*
+ * Handle message from client to specify the flooding mechanism for
+ * BUM packets. The default is to do head-end (ingress) replication
+ * and the other supported option is to disable it. This applies to
+ * all BUM traffic and disabling it applies to both the transmit and
+ * receive direction.
+ */
+void zebra_vxlan_flood_control(ZAPI_HANDLER_ARGS)
+{
+	struct stream *s;
+	enum vxlan_flood_control flood_ctrl;
+
+	if (zvrf_id(zvrf) != VRF_DEFAULT) {
+		zlog_err("EVPN flood control for non-default VRF %u",
+			 zvrf_id(zvrf));
+		return;
+	}
+
+	s = msg;
+	STREAM_GETC(s, flood_ctrl);
+
+	if (IS_ZEBRA_DEBUG_VXLAN)
+		zlog_debug("EVPN flood control %u, currently %u",
+			   flood_ctrl, zvrf->vxlan_flood_ctrl);
+
+	if (zvrf->vxlan_flood_ctrl == flood_ctrl)
+		return;
+
+	zvrf->vxlan_flood_ctrl = flood_ctrl;
+
+	/* Install or uninstall flood entries corresponding to
+	 * remote VTEPs.
+	 */
+	hash_iterate(zvrf->vni_table, zvni_handle_flooding_remote_vteps,
+		     zvrf);
+
+stream_failure:
+	return;
+}
+
+/*
  * Handle message from client to enable/disable advertisement of g/w macip
  * routes
  */
@@ -7073,12 +7137,15 @@ stream_failure:
  * When enabled, the VNI hash table will be built and MAC FDB table read;
  * when disabled, the entries should be deleted and remote VTEPs and MACs
  * uninstalled from the kernel.
+ * This also informs the setting for BUM handling at the time this change
+ * occurs; it is relevant only when specifying "learn".
  */
 void zebra_vxlan_advertise_all_vni(ZAPI_HANDLER_ARGS)
 {
 	struct stream *s = NULL;
 	int advertise = 0;
 	struct zebra_ns *zns = NULL;
+	enum vxlan_flood_control flood_ctrl;
 
 	if (zvrf_id(zvrf) != VRF_DEFAULT) {
 		zlog_debug("EVPN VNI Adv for non-default VRF %u",
@@ -7088,17 +7155,22 @@ void zebra_vxlan_advertise_all_vni(ZAPI_HANDLER_ARGS)
 
 	s = msg;
 	STREAM_GETC(s, advertise);
+	STREAM_GETC(s, flood_ctrl);
 
 	if (IS_ZEBRA_DEBUG_VXLAN)
-		zlog_debug("EVPN VNI Adv %s, currently %s",
+		zlog_debug("EVPN VNI Adv %s, currently %s, flood control %u",
 			   advertise ? "enabled" : "disabled",
-			   is_evpn_enabled() ? "enabled" : "disabled");
+			   is_evpn_enabled() ? "enabled" : "disabled",
+			   flood_ctrl);
 
 	if (zvrf->advertise_all_vni == advertise)
 		return;
 
 	zvrf->advertise_all_vni = advertise;
 	if (is_evpn_enabled()) {
+		/* Note BUM handling */
+		zvrf->vxlan_flood_ctrl = flood_ctrl;
+
 		/* Build VNI hash table and inform BGP. */
 		zvni_build_hash_table();