BGP Labelpool : Releasing the label in labelpool when VPN session gets removed

bgpd/bgp_mplsvpn.c

@@ -4074,6 +4074,35 @@ void bgp_vpn_leak_export(struct bgp *from_bgp)
 	}
 }
 
+/* It releases the label from labelpool which
+ * was previously assigned and unsets the flag based on reset arg
+ * This also used in vty to release the label and to change the allocation mode as well
+ */
+void bgp_vpn_release_label(struct bgp *bgp, afi_t afi, bool reset)
+{
+	if (!CHECK_FLAG(bgp->vpn_policy[afi].flags, BGP_VPN_POLICY_TOVPN_LABEL_AUTO))
+		return;
+	/*
+	 * label has previously been automatically
+	 * assigned by labelpool: release it
+	 *
+	 * NB if tovpn_label == MPLS_LABEL_NONE it
+	 * means the automatic assignment is in flight
+	 * and therefore the labelpool callback must
+	 * detect that the auto label is not needed.
+	 */
+	if (bgp->vpn_policy[afi].tovpn_label == MPLS_LABEL_NONE)
+		return;
+	if (CHECK_FLAG(bgp->vpn_policy[afi].flags, BGP_VPN_POLICY_TOVPN_LABEL_PER_NEXTHOP))
+		return;
+
+	bgp_lp_release(LP_TYPE_VRF, &bgp->vpn_policy[afi], bgp->vpn_policy[afi].tovpn_label);
+	bgp->vpn_policy[afi].tovpn_label = MPLS_LABEL_NONE;
+
+	if (reset)
+		UNSET_FLAG(bgp->vpn_policy[afi].flags, BGP_VPN_POLICY_TOVPN_LABEL_AUTO);
+}
+
 /* The nexthops values are compared to
  * find in the tree the appropriate cache entry
  */

bgpd/bgp_mplsvpn.h

@@ -352,6 +352,7 @@ extern void vpn_handle_router_id_update(struct bgp *bgp, bool withdraw,
 					bool is_config);
 extern void bgp_vpn_leak_unimport(struct bgp *from_bgp);
 extern void bgp_vpn_leak_export(struct bgp *from_bgp);
+extern void bgp_vpn_release_label(struct bgp *bgp, afi_t afi, bool reset);
 
 extern bool bgp_mplsvpn_path_uses_valid_mpls_label(struct bgp_path_info *pi);
 extern int

bgpd/bgp_vty.c

@@ -9941,26 +9941,9 @@ DEFPY (af_label_vpn_export,
 		UNSET_FLAG(bgp->vpn_policy[afi].flags,
 			   BGP_VPN_POLICY_TOVPN_LABEL_MANUAL_REG);
 
-	} else if (CHECK_FLAG(bgp->vpn_policy[afi].flags,
-			      BGP_VPN_POLICY_TOVPN_LABEL_AUTO)) {
+	} else if (CHECK_FLAG(bgp->vpn_policy[afi].flags, BGP_VPN_POLICY_TOVPN_LABEL_AUTO))
 		/* release any previous auto label */
-		if (bgp->vpn_policy[afi].tovpn_label != MPLS_LABEL_NONE) {
-
-			/*
-			 * label has previously been automatically
-			 * assigned by labelpool: release it
-			 *
-			 * NB if tovpn_label == MPLS_LABEL_NONE it
-			 * means the automatic assignment is in flight
-			 * and therefore the labelpool callback must
-			 * detect that the auto label is not needed.
-			 */
-
-			bgp_lp_release(LP_TYPE_VRF,
-				       &bgp->vpn_policy[afi],
-				       bgp->vpn_policy[afi].tovpn_label);
-		}
-	}
+		bgp_vpn_release_label(bgp, afi, false);
 
 	if (yes) {
 		if (label_auto) {

bgpd/bgpd.c

@@ -4006,6 +4006,9 @@ int bgp_delete(struct bgp *bgp)
 
 	bgp_vpn_leak_unimport(bgp);
 
+	bgp_vpn_release_label(bgp, AFI_IP, true);
+	bgp_vpn_release_label(bgp, AFI_IP6, true);
+
 	hook_call(bgp_inst_delete, bgp);
 
 	FOREACH_AFI_SAFI (afi, safi)

tests/topotests/bgp_vpnv4_ebgp_vpn_auto/r1/frr.conf

@@ -0,0 +1,117 @@
+interface r1-eth1 vrf vrf1
+ ip address 173.31.1.1/32
+!
+interface r1-eth2 vrf vrf2
+ ip address 173.31.1.2/32
+!
+interface r1-eth3 vrf vrf3
+ ip address 173.31.1.3/32
+!
+interface r1-eth4 vrf vrf4
+ ip address 173.31.1.4/32
+!
+interface r1-eth5 vrf vrf5
+ ip address 173.31.1.5/32
+!
+
+interface r1-eth0
+ ip address 192.168.0.1/24
+!
+
+interface r1-eth6
+ ip address 193.170.0.1/24
+
+interface lo
+ ip address 11.11.11.11/32
+!
+router ospf
+ ospf router-id 11.11.11.11
+ network 193.170.0.0/24 area 0.0.0.0
+ network 11.11.11.11/32 area 0.0.0.0
+ redistribute connected
+exit
+!
+mpls ldp
+ router-id 11.11.11.11
+ !
+ address-family ipv4
+  discovery transport-address 11.11.11.11
+  !
+  interface r1-eth6
+  exit
+  !
+ exit-address-family
+ !
+exit
+!
+bgp route-map delay-timer 1
+router bgp 65500
+ bgp router-id 192.0.2.1
+ no bgp ebgp-requires-policy
+ neighbor 192.168.0.2 remote-as 65501
+ address-family ipv4 unicast
+  no neighbor 192.168.0.2 activate
+ exit-address-family
+ address-family ipv4 vpn
+  neighbor 192.168.0.2 activate
+ exit-address-family
+!
+router bgp 65500 vrf vrf1
+ bgp router-id 192.0.2.1
+ address-family ipv4 unicast
+  redistribute connected
+  label vpn export auto
+  rd vpn export 445:1
+  rt vpn both 53:1
+  export vpn
+  import vpn
+ exit-address-family
+!
+router bgp 65500 vrf vrf2
+ bgp router-id 192.0.2.1
+ address-family ipv4 unicast
+  redistribute connected
+  label vpn export auto
+  rd vpn export 445:2
+  rt vpn both 53:2
+  export vpn
+  import vpn
+ exit-address-family
+!
+router bgp 65500 vrf vrf3
+ bgp router-id 192.0.2.1
+ address-family ipv4 unicast
+  redistribute connected
+  label vpn export auto
+  rd vpn export 445:3
+  rt vpn both 53:3
+  export vpn
+  import vpn
+ exit-address-family
+!
+router bgp 65500 vrf vrf4
+ bgp router-id 192.0.2.1
+ address-family ipv4 unicast
+  redistribute connected
+  label vpn export auto
+  rd vpn export 445:4
+  rt vpn both 53:4
+  export vpn
+  import vpn
+ exit-address-family
+!
+router bgp 65500 vrf vrf5
+ bgp router-id 192.0.2.1
+ address-family ipv4 unicast
+  redistribute connected
+  label vpn export auto
+  rd vpn export 445:5
+  rt vpn both 53:5
+  export vpn
+  import vpn
+ exit-address-family
+!
+
+interface r1-eth0
+ mpls bgp forwarding
+!

tests/topotests/bgp_vpnv4_ebgp_vpn_auto/r2/frr.conf

@@ -0,0 +1,88 @@
+interface r2-eth1 vrf vrf1
+ ip address 173.31.0.1/32
+!
+interface r2-eth2 vrf vrf2
+ ip address 173.31.0.2/32
+!
+interface r2-eth3 vrf vrf3
+ ip address 173.31.0.3/32
+!
+interface r2-eth4 vrf vrf4
+ ip address 173.31.0.4/32
+!
+interface r2-eth5 vrf vrf5
+ ip address 173.31.0.5/32
+!
+interface r2-eth0
+ ip address 192.168.0.2/24
+!
+router bgp 65501
+ bgp router-id 192.0.2.2
+ no bgp ebgp-requires-policy
+ neighbor 192.168.0.1 remote-as 65500
+ address-family ipv4 unicast
+  no neighbor 192.168.0.1 activate
+ exit-address-family
+ address-family ipv4 vpn
+  neighbor 192.168.0.1 activate
+ exit-address-family
+!
+router bgp 65501 vrf vrf1
+ bgp router-id 192.0.2.2
+ address-family ipv4 unicast
+  redistribute connected
+  label vpn export auto
+  rd vpn export 445:1
+  rt vpn both 53:1
+  export vpn
+  import vpn
+ exit-address-family
+!
+router bgp 65501 vrf vrf2
+ bgp router-id 192.0.2.2
+ address-family ipv4 unicast
+  redistribute connected
+  label vpn export auto
+  rd vpn export 445:2
+  rt vpn both 53:2
+  export vpn
+  import vpn
+ exit-address-family
+!
+router bgp 65501 vrf vrf3
+ bgp router-id 192.0.2.2
+ address-family ipv4 unicast
+  redistribute connected
+  label vpn export auto
+  rd vpn export 445:3
+  rt vpn both 53:3
+  export vpn
+  import vpn
+ exit-address-family
+!
+router bgp 65501 vrf vrf4
+ bgp router-id 192.0.2.2
+ address-family ipv4 unicast
+  redistribute connected
+  label vpn export auto
+  rd vpn export 445:4
+  rt vpn both 53:4
+  export vpn
+  import vpn
+ exit-address-family
+!
+router bgp 65501 vrf vrf5
+ bgp router-id 192.0.2.2
+ address-family ipv4 unicast
+  redistribute connected
+  label vpn export auto
+  rd vpn export 445:5
+  rt vpn both 53:5
+  export vpn
+  import vpn
+ exit-address-family
+!
+
+interface r2-eth0
+ mpls bgp forwarding
+!

tests/topotests/bgp_vpnv4_ebgp_vpn_auto/r3/frr.conf

@@ -0,0 +1,32 @@
+interface r3-eth0
+ ip address 193.170.0.2/24
+!
+interface lo
+ ip address 33.33.33.33/32
+!
+interface r3-eth1
+ ip address 180.170.0.2/32
+!
+interface r3-eth2
+ ip address 180.170.0.3/32
+!
+router ospf
+ ospf router-id 33.33.33.33
+ network 193.170.0.0/24 area 0.0.0.0
+ network 33.33.33.33/32 area 0.0.0.0
+ redistribute connected
+exit
+!
+mpls ldp
+ router-id 33.33.33.33
+ !
+ address-family ipv4
+  discovery transport-address 33.33.33.33
+  !
+  interface r3-eth0
+  exit
+  !
+ exit-address-family
+ !
+exit
+!