topotests: add nexthop-group allow-recursion test

Add a nexthop group test that ensures that a recursive
next-hop is resolved in zebra.

Signed-off-by: Philippe Guibert <[email protected]>

tests/topotests/all_protocol_startup/r1/ip_nht.ref

@@ -53,6 +53,10 @@ VRF default:
 6.6.6.4
  unresolved
  Client list: pbr(fd XX)
+192.0.2.200
+ resolved via static
+ via 192.168.0.208, r1-eth0 (vrf default), weight 1
+ Client list: pbr(fd XX)
 192.168.0.2
  resolved via connected
  is directly connected, r1-eth0 (vrf default)
@@ -61,6 +65,10 @@ VRF default:
  resolved via connected
  is directly connected, r1-eth0 (vrf default)
  Client list: static(fd XX)
+192.168.0.208
+ resolved via connected
+ is directly connected, r1-eth0 (vrf default)
+ Client list: static(fd XX)
 192.168.7.10
  resolved via connected
  is directly connected, r1-eth7 (vrf default)

tests/topotests/all_protocol_startup/r1/ipv4_routes.ref

@@ -28,6 +28,7 @@ S>* 1.1.1.5/32 [1/0] is directly connected, r1-eth5, weight 1, XX:XX:XX
 S>* 1.1.1.6/32 [1/0] is directly connected, r1-eth6, weight 1, XX:XX:XX
 S>* 1.1.1.7/32 [1/0] is directly connected, r1-eth7, weight 1, XX:XX:XX
 S>* 1.1.1.8/32 [1/0] is directly connected, r1-eth8, weight 1, XX:XX:XX
+S>* 192.0.2.0/24 [1/0] via 192.168.0.208, r1-eth0, weight 1, XX:XX:XX
 S>* 4.5.6.10/32 [1/0] via 192.168.0.2, r1-eth0, weight 1, XX:XX:XX
 S>* 4.5.6.11/32 [1/0] via 192.168.0.2, r1-eth0, weight 1, XX:XX:XX
 S>* 4.5.6.12/32 [1/0] is directly connected, r1-eth0, weight 1, XX:XX:XX

tests/topotests/all_protocol_startup/r1/zebra.conf

@@ -46,6 +46,10 @@ ip route 4.5.6.16/32 192.168.0.4 10
 ip route 4.5.6.17/32 192.168.0.2 tag 9000
 ip route 4.5.6.17/32 192.168.0.2 tag 10000
 
+! Create a static route to test recursive
+! resolution
+ip route 192.0.2.0/24 192.168.0.208
+
 !
 interface r1-eth0
  description to sw0 - no routing protocol

tests/topotests/all_protocol_startup/test_all_protocol_startup.py

@@ -397,7 +397,7 @@ def route_get_nhg_id(route_str):
     return nhg_id
 
 
-def verify_nexthop_group(nhg_id, recursive=False, ecmp=0):
+def verify_nexthop_group(nhg_id, recursive=False, ecmp=0, recursive_again=False):
     net = get_topogen().net
     count = 0
     valid = None
@@ -440,7 +440,7 @@ def verify_nexthop_group(nhg_id, recursive=False, ecmp=0):
                     continue
 
                 resolved_id = int(depends[0])
-                verify_nexthop_group(resolved_id, False)
+                verify_nexthop_group(resolved_id, recursive=recursive_again)
         else:
             installed = re.search(r"Installed", output)
             if installed is None:
@@ -613,6 +613,29 @@ def test_nexthop_groups():
         % nhg_id
     )
 
+    ## nexthop-group allow-recursion
+    ## create a static route, and use that static route to resolve the nexthop-group
+    net["r1"].cmd('vtysh -c "c t" -c "zebra nexthop-group keep 10"')
+    net["r1"].cmd(
+        'vtysh -c "c t" -c "nexthop-group allowrecursion" -c "allow-recursion" -c "nexthop 192.0.2.200"'
+    )
+    net["r1"].cmd(
+        'vtysh -c "sharp install routes 9.9.9.9 nexthop-group allowrecursion 1"'
+    )
+    nhg_id = route_get_nhg_id("9.9.9.9/32")
+    verify_nexthop_group(nhg_id, recursive=True, ecmp=0, recursive_again=True)
+
+    net["r1"].cmd('vtysh -c "sharp remove routes 9.9.9.9 1"')
+    net["r1"].cmd(
+        'vtysh -c "c t" -c "nexthop-group allowrecursion" -c "no allow-recursion"'
+    )
+    output = net["r1"].cmd('vtysh -c "show nexthop-group rib %d"' % nhg_id)
+    found = re.search(r"Time to Deletion", output)
+    assert found is not None, (
+        "Route 9.9.9.9/32 with Nexthop Group ID=%d is not scheduled for removal"
+        % nhg_id
+    )
+
     ## Remove all NHG routes
 
     net["r1"].cmd('vtysh -c "sharp remove routes 2.2.2.1 1"')