bgpd: set ifindex only v6 nexthops and nexthops that match peer's LL

For v4 nexthops, ifindex was being set. Modified the check to set
ifindex only for v6 nexthops. Also modified the check to set ifindex
only if the v6 nexthop matches peer's LL address.

Signed-off-by: Pooja Jagadeesh Doijode <pdoijode@nvidia.com>

diff --git a/bgpd/bgp_nht.c b/bgpd/bgp_nht.c
index 733dcc72a2d568c6127c25d0d80a513f11fa9c2c..3bf7ac91b39626669693354b016f4918d12d6126 100644 (file)
--- a/bgpd/bgp_nht.c
+++ b/bgpd/bgp_nht.c
@@ -317,11 +317,18 @@ int bgp_find_or_add_nexthop(struct bgp *bgp_route, struct bgp *bgp_nexthop,
                        return 1;
 
                /*
-                * If path is learnt from an interface based peer,
+                * If it's a V6 nexthop, path is learnt from a v6 LL peer,
+                * and if the NH prefix matches peer's LL address then
                 * set the ifindex to peer's interface index so that
                 * correct nexthop can be found in nexthop tree.
+                *
+                * NH could be set to different v6 LL address (compared to
+                * peer's LL) using route-map. In such a scenario, do not set
+                * the ifindex.
                 */
-               if (pi->peer->conf_if)
+               if (afi == AFI_IP6 &&
+                   IN6_IS_ADDR_LINKLOCAL(&pi->peer->su.sin6.sin6_addr) &&
+                   IPV6_ADDR_SAME(&pi->peer->su.sin6.sin6_addr, &p.u.prefix6))
                        ifindex = pi->peer->su.sin6.sin6_scope_id;
 
                if (!is_bgp_static_route && orig_prefix

diff --git a/tests/topotests/bgp_blackhole_community/r4/bgpd.conf b/tests/topotests/bgp_blackhole_community/r4/bgpd.conf
index 0ac963e6424c9c1ff4a71979db848ec86bd3370b..eca12bd3d9a07a28462b73ec585459654b21c087 100644 (file)
--- a/tests/topotests/bgp_blackhole_community/r4/bgpd.conf
+++ b/tests/topotests/bgp_blackhole_community/r4/bgpd.conf
@@ -4,3 +4,10 @@ router bgp 65002
   no bgp ebgp-requires-policy
   neighbor r4-eth0 interface remote-as internal
 !
+address-family ipv4 unicast
+  neighbor r4-eth0 route-map FOO in
+exit-address-family
+!
+route-map FOO permit 10
+ set ipv6 next-hop local fe80::202:ff:fe00:99
+exit

diff --git a/tests/topotests/bgp_blackhole_community/test_bgp_blackhole_community.py b/tests/topotests/bgp_blackhole_community/test_bgp_blackhole_community.py
index 16191911a9147b4a9d02a25eafff3ebf46ea5cee..9f5c0ef924bd433b1d258ea82459257cef7275a8 100644 (file)
--- a/tests/topotests/bgp_blackhole_community/test_bgp_blackhole_community.py
+++ b/tests/topotests/bgp_blackhole_community/test_bgp_blackhole_community.py
@@ -107,6 +107,23 @@ def test_bgp_blackhole_community():
 
         return topotest.json_cmp(output, expected)
 
+    def _bgp_verify_nexthop_validity():
+        output = json.loads(tgen.gears["r4"].vtysh_cmd("show bgp nexthop json"))
+
+        expected = {
+            "ipv6": {
+                "fe80::202:ff:fe00:99": {
+                    "valid": True,
+                    "complete": True,
+                    "igpMetric": 0,
+                    "pathCount": 2,
+                    "nexthops": [{"interfaceName": "r4-eth0"}],
+                },
+            }
+        }
+
+        return topotest.json_cmp(output, expected)
+
     test_func = functools.partial(_bgp_converge)
     success, result = topotest.run_and_expect(test_func, None, count=60, wait=0.5)
 
@@ -124,7 +141,6 @@ def test_bgp_blackhole_community():
     )
 
     step("Check if 172.16.255.254/32 is advertised to iBGP peers")
-
     test_func = functools.partial(_bgp_no_advertise_ibgp)
     success, result = topotest.run_and_expect(test_func, None, count=60, wait=0.5)
 
@@ -134,6 +150,11 @@ def test_bgp_blackhole_community():
         tgen.gears["r2"]
     )
 
+    step("Verify if the nexthop set via route-map on r4 is marked valid")
+    test_func = functools.partial(_bgp_verify_nexthop_validity)
+    success, result = topotest.run_and_expect(test_func, None, count=60, wait=0.5)
+    assert result is None, 'Nexthops are not valid "{}"'.format(tgen.gears["r4"])
+
 
 if __name__ == "__main__":
     args = ["-s"] + sys.argv[1:]

diff --git a/tests/topotests/bgp_vpn_5549_route_map/test_bgp_vpn_5549_route_map.py b/tests/topotests/bgp_vpn_5549_route_map/test_bgp_vpn_5549_route_map.py
index 533af19d93fc2fbde59cd58b7ed040305b62918e..84ef603d6e3c61bf034a21eaedb0569f6bf22847 100644 (file)
--- a/tests/topotests/bgp_vpn_5549_route_map/test_bgp_vpn_5549_route_map.py
+++ b/tests/topotests/bgp_vpn_5549_route_map/test_bgp_vpn_5549_route_map.py
@@ -115,10 +115,56 @@ def test_bgp_vpn_5549():
         }
         return topotest.json_cmp(output, expected)
 
+    def _bgp_verify_v4_nexthop_validity():
+        output = json.loads(tgen.gears["cpe1"].vtysh_cmd("show bgp nexthop json"))
+        expected = {
+            "ipv4": {
+                "192.168.1.2": {
+                    "valid": True,
+                    "complete": True,
+                    "igpMetric": 0,
+                    "pathCount": 0,
+                    "nexthops": [{"interfaceName": "cpe1-eth0"}],
+                },
+            }
+        }
+        return topotest.json_cmp(output, expected)
+
+    def _bgp_verify_v6_global_nexthop_validity():
+        output = json.loads(tgen.gears["pe2"].vtysh_cmd("show bgp nexthop json"))
+        expected = {
+            "ipv6": {
+                "2001:db8::1": {
+                    "valid": True,
+                    "complete": True,
+                    "igpMetric": 0,
+                    "pathCount": 2,
+                    "nexthops": [{"interfaceName": "pe2-eth0"}],
+                },
+                "2001:db8:1::1": {
+                    "valid": True,
+                    "complete": True,
+                    "igpMetric": 20,
+                    "pathCount": 2,
+                    "peer": "2001:db8:1::1",
+                    "nexthops": [{"interfaceName": "pe2-eth0"}],
+                },
+            }
+        }
+        return topotest.json_cmp(output, expected)
+
     test_func = functools.partial(_bgp_vpn_nexthop_changed)
     _, result = topotest.run_and_expect(test_func, None, count=60, wait=0.5)
     assert result is None, "Failed overriding IPv6 next-hop for VPN underlay"
 
+    test_func = functools.partial(_bgp_verify_v4_nexthop_validity)
+    _, result = topotest.run_and_expect(test_func, None, count=60, wait=0.5)
+    assert result is None, "IPv4 nexthop is invalid"
+
+    test_func = functools.partial(_bgp_verify_v6_global_nexthop_validity)
+    _, result = topotest.run_and_expect(test_func, None, count=60, wait=0.5)
+    assert result is None, "IPv6 nexthop is invalid"
+
 
 if __name__ == "__main__":
     args = ["-s"] + sys.argv[1:]