From 47bf0432d3e47807b95531aa64aab0c39ddcacce Mon Sep 17 00:00:00 2001
From: Chirag Shah <chirag@cumulusnetworks.com>
Date: Tue, 12 Mar 2019 18:41:01 -0700
Subject: [PATCH] bgpd: router mac same as self skip route install

When a bgp-peer comes up prior to l3vnis are up in bgpd.
The EVPN routes (type-2/type-5) are learnt via peer.
The routes can have one of interface's MAC in rmac attribute.
The self rmac check would bypass as l3vni is not present.

Once l3vni has come up in bgpd, while installing evpn
routes in vrf table, perform rmac attribute check against self mac.
The routes with rmac of ours will be removed via re-scan
of routes during bgp_mac_rescan_all_evpn_tables when
interface mac is added to bgp.

Ticket:CM-24224
Reviewed By:CCR-8423
Testing Done:

Signed-off-by: Chirag Shah <chirag@cumulunetworks.com>
---
 bgpd/bgp_evpn.c | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/bgpd/bgp_evpn.c b/bgpd/bgp_evpn.c
index 19cda453f5..6ced286dde 100644
--- a/bgpd/bgp_evpn.c
+++ b/bgpd/bgp_evpn.c
@@ -48,6 +48,7 @@
 #include "bgpd/bgp_zebra.h"
 #include "bgpd/bgp_nexthop.h"
 #include "bgpd/bgp_addpath.h"
+#include "bgpd/bgp_mac.h"
 
 /*
  * Definitions and external declarations.
@@ -2945,6 +2946,41 @@ static int install_uninstall_routes_for_es(struct bgp *bgp,
 	return 0;
 }
 
+/* This API will scan evpn routes for checking attribute's rmac
+ * macthes with bgp instance router mac. It avoid installing
+ * route into bgp vrf table and remote rmac in bridge table.
+ */
+static int bgp_evpn_route_rmac_self_check(struct bgp *bgp_vrf,
+					  struct prefix_evpn *evp,
+					  struct bgp_path_info *pi)
+{
+	/* evpn route could have learnt prior to L3vni has come up,
+	 * perform rmac check before installing route and
+	 * remote router mac.
+	 * The route will be removed from global bgp table once
+	 * SVI comes up with MAC and stored in hash, triggers
+	 * bgp_mac_rescan_all_evpn_tables.
+	 */
+	if (pi->attr &&
+	    memcmp(&bgp_vrf->rmac, &pi->attr->rmac, ETH_ALEN) == 0) {
+		if (bgp_debug_update(pi->peer, NULL, NULL, 1)) {
+			char buf1[PREFIX_STRLEN];
+			char attr_str[BUFSIZ] = {0};
+
+			bgp_dump_attr(pi->attr, attr_str, BUFSIZ);
+
+			zlog_debug("%s: bgp %u prefix %s with attr %s - DENIED due to self mac",
+				__func__, bgp_vrf->vrf_id,
+				prefix2str(evp, buf1, sizeof(buf1)),
+				attr_str);
+		}
+
+		return 1;
+	}
+
+	return 0;
+}
+
 /*
  * Install or uninstall mac-ip routes are appropriate for this
  * particular VRF.
@@ -3001,6 +3037,10 @@ static int install_uninstall_routes_for_vrf(struct bgp *bgp_vrf, int install)
 					continue;
 
 				if (is_route_matching_for_vrf(bgp_vrf, pi)) {
+					if (bgp_evpn_route_rmac_self_check(
+								bgp_vrf, evp, pi))
+						continue;
+
 					if (install)
 						ret = install_evpn_route_entry_in_vrf(
 							bgp_vrf, evp, pi);