bgpd: fix allow to reconfigure advertise-all-vni on non default vrf

When running 'no advertise-all-vni' command on the evpn bgp instance,
then reconfiguring it is not possible:

> r2(config)# router bgp 65000 vrf vrf-evpn
> r2(config-router)# address-family l2vpn evpn
> r2(config-router-af)#
> r2(config-router-af)# no advertise-all-vni
> r2(config-router-af)# advertise-all-vni
> % Please unconfigure EVPN in VRF default
> r2(config-router-af)#

Actually, the evpn bgp instance is not the default one. Fix this by not
setting the bgp evpn instance to the default BGP instance, when removing
the 'advertise-all-vni' command.

Fixes: e2f3a93 ("bgpd: Allow non-default instance to be EVPN one")
Signed-off-by: Philippe Guibert <[email protected]>

Author: pguibert6WIND

bgpd/bgp_evpn_vty.c

@@ -3516,7 +3516,7 @@ 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_set_evpn(NULL);
 	bgp_zebra_advertise_all_vni(bgp, bgp->advertise_all_vni);
 	bgp_evpn_cleanup_on_disable(bgp);
 }
@@ -3739,9 +3739,14 @@ DEFUN (no_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)
+		return CMD_SUCCESS;
+
 	evpn_unset_advertise_all_vni(bgp);
 	return CMD_SUCCESS;
 }