bgpd: Allow non-default instance to be EVPN one

This makes the instance bearing the advertise-all-vni config option
register to zebra as the EVPN one, forwarding it the option.

Signed-off-by: Tuetuopay <tuetuopay@me.com>
Sponsored-by: Scaleway

6 files changed, 65 insertions, 11 deletions

diff --git a/bgpd/bgp_evpn.h b/bgpd/bgp_evpn.h
index fbf30083e1..bcc524d5aa 100644
--- a/bgpd/bgp_evpn.h
+++ b/bgpd/bgp_evpn.h
@@ -31,7 +31,7 @@ static inline int is_evpn_enabled(void)
 {
 	struct bgp *bgp = NULL;
 
-	bgp = bgp_get_default();
+	bgp = bgp_get_evpn();
 	return bgp ? bgp->advertise_all_vni : 0;
 }
 
diff --git a/bgpd/bgp_evpn_vty.c b/bgpd/bgp_evpn_vty.c
index 8437c4024e..9ac1af046a 100644
--- a/bgpd/bgp_evpn_vty.c
+++ b/bgpd/bgp_evpn_vty.c
@@ -2757,6 +2757,7 @@ static void evpn_unset_advertise_subnet(struct bgp *bgp, struct bgpevpn *vpn)
 static void evpn_set_advertise_all_vni(struct bgp *bgp)
 {
 	bgp->advertise_all_vni = 1;
+	bgp_set_evpn(bgp);
 	bgp_zebra_advertise_all_vni(bgp, bgp->advertise_all_vni);
 }
 
@@ -2767,6 +2768,7 @@ static void evpn_set_advertise_all_vni(struct bgp *bgp)
 static void evpn_unset_advertise_all_vni(struct bgp *bgp)
 {
 	bgp->advertise_all_vni = 0;
+	bgp_set_evpn(bgp_get_default());
 	bgp_zebra_advertise_all_vni(bgp, bgp->advertise_all_vni);
 	bgp_evpn_cleanup_on_disable(bgp);
 }
@@ -2954,9 +2956,18 @@ DEFUN (bgp_evpn_advertise_all_vni,
        "Advertise All local VNIs\n")
 {
 	struct bgp *bgp = VTY_GET_CONTEXT(bgp);
+	struct bgp *bgp_evpn = NULL;
 
 	if (!bgp)
 		return CMD_WARNING;
+
+	bgp_evpn = bgp_get_evpn();
+	if (bgp_evpn && bgp_evpn != bgp) {
+		vty_out(vty, "%% Please unconfigure EVPN in VRF %s\n",
+			bgp_evpn->name);
+		return CMD_WARNING_CONFIG_FAILED;
+	}
+
 	evpn_set_advertise_all_vni(bgp);
 	return CMD_SUCCESS;
 }
diff --git a/bgpd/bgp_main.c b/bgpd/bgp_main.c
index 47e7c1686f..697889cc6b 100644
--- a/bgpd/bgp_main.c
+++ b/bgpd/bgp_main.c
@@ -171,7 +171,7 @@ void sigusr1(void)
 */
 static __attribute__((__noreturn__)) void bgp_exit(int status)
 {
-	struct bgp *bgp, *bgp_default;
+	struct bgp *bgp, *bgp_default, *bgp_evpn;
 	struct listnode *node, *nnode;
 
 	/* it only makes sense for this to be called on a clean exit */
@@ -184,13 +184,16 @@ static __attribute__((__noreturn__)) void bgp_exit(int status)
 	bgp_close();
 
 	bgp_default = bgp_get_default();
+	bgp_evpn = bgp_get_evpn();
 
 	/* reverse bgp_master_init */
 	for (ALL_LIST_ELEMENTS(bm->bgp, node, nnode, bgp)) {
-		if (bgp_default == bgp)
+		if (bgp_default == bgp || bgp_evpn == bgp)
 			continue;
 		bgp_delete(bgp);
 	}
+	if (bgp_evpn && bgp_evpn != bgp_default)
+		bgp_delete(bgp_evpn);
 	if (bgp_default)
 		bgp_delete(bgp_default);
 
diff --git a/bgpd/bgp_zebra.c b/bgpd/bgp_zebra.c
index 5f0b20e029..398735d7a4 100644
--- a/bgpd/bgp_zebra.c
+++ b/bgpd/bgp_zebra.c
@@ -1632,7 +1632,7 @@ int bgp_redistribute_set(struct bgp *bgp, afi_t afi, int type,
 			return CMD_WARNING;
 
 #if ENABLE_BGP_VNC
-		if (bgp->vrf_id == VRF_DEFAULT
+		if (bgp->advertise_all_vni
 		    && type == ZEBRA_ROUTE_VNC_DIRECT) {
 			vnc_export_bgp_enable(
 				bgp, afi); /* only enables if mode bits cfg'd */
@@ -1794,7 +1794,7 @@ int bgp_redistribute_unset(struct bgp *bgp, afi_t afi, int type,
  * status. red lookup fails if there is no zebra connection.
  */
 #if ENABLE_BGP_VNC
-	if (bgp->vrf_id == VRF_DEFAULT && type == ZEBRA_ROUTE_VNC_DIRECT) {
+	if (bgp->advertise_all_vni && type == ZEBRA_ROUTE_VNC_DIRECT) {
 		vnc_export_bgp_disable(bgp, afi);
 	}
 #endif
@@ -1861,9 +1861,8 @@ void bgp_zebra_instance_register(struct bgp *bgp)
 	/* Register for router-id, interfaces, redistributed routes. */
 	zclient_send_reg_requests(zclient, bgp->vrf_id);
 
-	/* For default instance, register to learn about VNIs, if appropriate.
-	 */
-	if (bgp->inst_type == BGP_INSTANCE_TYPE_DEFAULT && is_evpn_enabled())
+	/* For EVPN instance, register to learn about VNIs, if appropriate. */
+	if (bgp->advertise_all_vni)
 		bgp_zebra_advertise_all_vni(bgp, 1);
 
 	bgp_nht_register_nexthops(bgp);
@@ -1881,9 +1880,8 @@ void bgp_zebra_instance_deregister(struct bgp *bgp)
 	if (BGP_DEBUG(zebra, ZEBRA))
 		zlog_debug("Deregistering VRF %u", bgp->vrf_id);
 
-	/* For default instance, unregister learning about VNIs, if appropriate.
-	 */
-	if (bgp->inst_type == BGP_INSTANCE_TYPE_DEFAULT && is_evpn_enabled())
+	/* For EVPN instance, unregister learning about VNIs, if appropriate. */
+	if (bgp->advertise_all_vni)
 		bgp_zebra_advertise_all_vni(bgp, 0);
 
 	/* Deregister for router-id, interfaces, redistributed routes. */
diff --git a/bgpd/bgpd.c b/bgpd/bgpd.c
index d99b402e28..8fcf417b3a 100644
--- a/bgpd/bgpd.c
+++ b/bgpd/bgpd.c
@@ -2872,6 +2872,12 @@ static struct bgp *bgp_create(as_t *as, const char *name,
 				   name, *as);
 	}
 
+	/* Default the EVPN VRF to the default one */
+	if (inst_type == BGP_INSTANCE_TYPE_DEFAULT && !bgp_master.bgp_evpn) {
+		bgp_lock(bgp);
+		bm->bgp_evpn = bgp;
+	}
+
 	bgp_lock(bgp);
 	bgp->heuristic_coalesce = true;
 	bgp->inst_type = inst_type;
@@ -3070,6 +3076,29 @@ struct bgp *bgp_lookup_by_vrf_id(vrf_id_t vrf_id)
 	return (vrf->info) ? (struct bgp *)vrf->info : NULL;
 }
 
+/* Sets the BGP instance where EVPN is enabled */
+void bgp_set_evpn(struct bgp *bgp)
+{
+	if (bm->bgp_evpn == bgp)
+		return;
+
+	/* First, release the reference count we hold on the instance */
+	if (bm->bgp_evpn)
+		bgp_unlock(bm->bgp_evpn);
+
+	bm->bgp_evpn = bgp;
+
+	/* Increase the reference count on this new VRF */
+	if (bm->bgp_evpn)
+		bgp_lock(bm->bgp_evpn);
+}
+
+/* Returns the BGP instance where EVPN is enabled, if any */
+struct bgp *bgp_get_evpn(void)
+{
+	return bm->bgp_evpn;
+}
+
 /* handle socket creation or deletion, if necessary
  * this is called for all new BGP instances
  */
@@ -3354,6 +3383,14 @@ int bgp_delete(struct bgp *bgp)
 	if (vrf)
 		bgp_vrf_unlink(bgp, vrf);
 
+	/* Update EVPN VRF pointer */
+	if (bm->bgp_evpn == bgp) {
+		if (bgp->inst_type == BGP_INSTANCE_TYPE_DEFAULT)
+			bgp_set_evpn(NULL);
+		else
+			bgp_set_evpn(bgp_get_default());
+	}
+
 	thread_master_free_unused(bm->master);
 	bgp_unlock(bgp); /* initial reference */
 
diff --git a/bgpd/bgpd.h b/bgpd/bgpd.h
index c7d137c76c..f9c269e3e6 100644
--- a/bgpd/bgpd.h
+++ b/bgpd/bgpd.h
@@ -150,6 +150,9 @@ struct bgp_master {
 	/* dynamic mpls label allocation pool */
 	struct labelpool labelpool;
 
+	/* BGP-EVPN VRF ID. Defaults to default VRF (if any) */
+	struct bgp* bgp_evpn;
+
 	bool terminating;	/* global flag that sigint terminate seen */
 	QOBJ_FIELDS
 };
@@ -1506,6 +1509,8 @@ extern struct bgp *bgp_get_default(void);
 extern struct bgp *bgp_lookup(as_t, const char *);
 extern struct bgp *bgp_lookup_by_name(const char *);
 extern struct bgp *bgp_lookup_by_vrf_id(vrf_id_t);
+extern struct bgp *bgp_get_evpn(void);
+extern void bgp_set_evpn(struct bgp *bgp);
 extern struct peer *peer_lookup(struct bgp *, union sockunion *);
 extern struct peer *peer_lookup_by_conf_if(struct bgp *, const char *);
 extern struct peer *peer_lookup_by_hostname(struct bgp *, const char *);