BGP route reflector should reflect RIB-failure routes

projects/batfish/src/main/java/org/batfish/dataplane/ibdp/BgpRoutingProcess.java

@@ -1049,6 +1049,9 @@ private Stream<RouteAdvertisement<Bgpv4Route>> getOutgoingRoutesForEdge(
               r ->
                   // Received from 0.0.0.0 indicates local origination
                   (_exportFromBgpRib && Ip.ZERO.equals(r.getRoute().getRoute().getReceivedFromIp()))
+                      // RIB-failure routes included
+                      || isReflectable(r.getRoute(), session, ourConfig)
+                      // RIB-failure routes excluded
                       || _mainRib.containsRoute(r.getRoute())));
     }
 
@@ -1123,6 +1126,19 @@ private Stream<RouteAdvertisement<Bgpv4Route>> getOutgoingRoutesForEdge(
     return Stream.concat(advertisementStream, neighborGeneratedRoutes);
   }
 
+  private static boolean isReflectable(
+      AnnotatedRoute<Bgpv4Route> route, BgpSessionProperties session, BgpPeerConfig ourConfig) {
+    switch (session.getSessionType()) {
+      case IBGP:
+      case IBGP_UNNUMBERED:
+        break;
+      default:
+        return false;
+    }
+    return route.getRoute().getProtocol().equals(RoutingProtocol.IBGP)
+        && ourConfig.getAddressFamily(Type.IPV4_UNICAST).getRouteReflectorClient();
+  }
+
   /**
    * Check whether given {@link GeneratedRoute} should be sent to a BGP neighbor. This checks
    * activation conditions for the generated route, and converts it to a {@link Bgpv4Route}. No

projects/batfish/src/test/java/org/batfish/dataplane/ibdp/IncrementalDataPlanePluginTest.java

@@ -48,6 +48,7 @@
 import org.batfish.datamodel.BgpPeerConfigId;
 import org.batfish.datamodel.BgpProcess;
 import org.batfish.datamodel.BgpSessionProperties;
+import org.batfish.datamodel.Bgpv4Route;
 import org.batfish.datamodel.ConcreteInterfaceAddress;
 import org.batfish.datamodel.Configuration;
 import org.batfish.datamodel.ConfigurationFormat;
@@ -230,6 +231,55 @@ public void testBgpOscillation() throws IOException {
     dataPlanePlugin.computeDataPlane(batfish.getSnapshot());
   }
 
+  /*
+   Topology:
+          R2
+         /  \
+        R1--R3
+
+   - R2 is a route reflector, with clients R1 and R3
+   - R1 sends 5.5.5.5/32 to R2 and changes its NHIP to its interface address for the R1<=>R3 link
+   - R2 has a static discard route for 5.5.5.5/32, so the BGP route goes into RIB-failure
+   - R2 should still reflect 5.5.5.5/32 to R3
+  */
+  @Test
+  public void testRouteReflectorRibFailure() throws IOException {
+    String testrigName = "rr-rib-failure";
+    List<String> configurationNames = ImmutableList.of("r1", "r2", "r3");
+    Prefix advPrefix = Prefix.strict("5.5.5.5/32");
+
+    Batfish batfish =
+        BatfishTestUtils.getBatfishFromTestrigText(
+            TestrigText.builder()
+                .setConfigurationFiles(TESTRIGS_PREFIX + testrigName, configurationNames)
+                .build(),
+            _folder);
+    batfish.getSettings().setDataplaneEngineName(IncrementalDataPlanePlugin.PLUGIN_NAME);
+    batfish.computeDataPlane(batfish.getSnapshot());
+    DataPlane dataplane = batfish.loadDataPlane(batfish.getSnapshot());
+
+    // Check BGP RIB routes
+    Set<Bgpv4Route> r2BgpRibRoutes =
+        dataplane.getBgpRoutes().get("r2", Configuration.DEFAULT_VRF_NAME);
+    Set<Bgpv4Route> r3BgpRibRoutes =
+        dataplane.getBgpRoutes().get("r3", Configuration.DEFAULT_VRF_NAME);
+    assertThat(r2BgpRibRoutes, hasItem(hasPrefix(advPrefix)));
+    assertThat(r3BgpRibRoutes, hasItem(hasPrefix(advPrefix)));
+
+    // Check main RIB routes
+    Set<AbstractRoute> r2MainRibRoutes =
+        dataplane.getRibs().get("r2").get(Configuration.DEFAULT_VRF_NAME).getRoutes();
+    Set<AbstractRoute> r3MainRibRoutes =
+        dataplane.getRibs().get("r3").get(Configuration.DEFAULT_VRF_NAME).getRoutes();
+    assertThat(
+        r2MainRibRoutes, hasItem(allOf(hasPrefix(advPrefix), hasProtocol(RoutingProtocol.STATIC))));
+    assertThat(
+        r2MainRibRoutes,
+        not(hasItem(allOf(hasPrefix(advPrefix), hasProtocol(RoutingProtocol.IBGP)))));
+    assertThat(
+        r3MainRibRoutes, hasItem(allOf(hasPrefix(advPrefix), hasProtocol(RoutingProtocol.IBGP))));
+  }
+
   @Test
   public void testEbgpAcceptSameNeighborID() throws IOException {
     String testrigName = "ebgp-accept-routerid-match";

projects/batfish/src/test/resources/org/batfish/dataplane/ibdp/testrigs/rr-rib-failure/configs/r1

@@ -0,0 +1,34 @@
+!RANCID-CONTENT-TYPE: cisco
+!
+hostname r1
+!
+interface Loopback0
+ ip address 1.1.1.1 255.255.255.255
+!
+interface GigabitEthernet0/1
+ ip address 10.12.0.1 255.255.255.0
+!
+interface GigabitEthernet0/2
+ ip address 10.13.0.1 255.255.255.0
+!
+router bgp 1
+ bgp router-id 1.1.1.1
+ neighbor 2.2.2.2 remote-as 1
+ neighbor 2.2.2.2 update-source Loopback0
+ !
+ address-family ipv4
+  redistribute static route-map rs
+  neighbor 2.2.2.2 activate
+  neighbor 2.2.2.2 soft-reconfiguration inbound
+ exit-address-family
+!
+ip route 2.2.2.2 255.255.255.255 10.12.0.2
+ip route 5.5.5.5 255.255.255.255 Null0
+!
+ip prefix-list five seq 5 permit 5.5.5.5/32
+!
+route-map rs permit 100
+ match ip address prefix-list five
+ set ip next-hop 10.13.0.1
+!
+end

projects/batfish/src/test/resources/org/batfish/dataplane/ibdp/testrigs/rr-rib-failure/configs/r2

@@ -0,0 +1,35 @@
+!RANCID-CONTENT-TYPE: cisco
+!
+hostname r2
+!
+interface Loopback0
+ ip address 2.2.2.2 255.255.255.255
+!
+interface GigabitEthernet0/1
+ ip address 10.12.0.2 255.255.255.0
+!
+interface GigabitEthernet0/2
+ ip address 10.23.0.2 255.255.255.0
+!
+router bgp 1
+ bgp router-id 2.2.2.2
+ neighbor 1.1.1.1 remote-as 1
+ neighbor 1.1.1.1 update-source Loopback0
+ neighbor 3.3.3.3 remote-as 1
+ neighbor 3.3.3.3 update-source Loopback0
+ !
+ address-family ipv4
+  neighbor 1.1.1.1 activate
+  neighbor 1.1.1.1 route-reflector-client
+  neighbor 1.1.1.1 soft-reconfiguration inbound
+  neighbor 3.3.3.3 activate
+  neighbor 3.3.3.3 route-reflector-client
+  neighbor 3.3.3.3 soft-reconfiguration inbound
+ exit-address-family
+!
+ip route 1.1.1.1 255.255.255.255 10.12.0.1
+ip route 3.3.3.3 255.255.255.255 10.23.0.3
+ip route 5.5.5.5 255.255.255.255 Null0
+ip route 10.13.0.1 255.255.255.255 10.12.0.1
+!
+end

projects/batfish/src/test/resources/org/batfish/dataplane/ibdp/testrigs/rr-rib-failure/configs/r3

@@ -0,0 +1,26 @@
+!RANCID-CONTENT-TYPE: cisco
+!
+hostname r3
+!
+interface Loopback0
+ ip address 3.3.3.3 255.255.255.255
+!
+interface GigabitEthernet0/1
+ ip address 10.13.0.3 255.255.255.0
+!
+interface GigabitEthernet0/2
+ ip address 10.23.0.3 255.255.255.0
+!
+router bgp 1
+ bgp router-id 3.3.3.3
+ neighbor 2.2.2.2 remote-as 1
+ neighbor 2.2.2.2 update-source Loopback0
+ !
+ address-family ipv4
+  neighbor 2.2.2.2 activate
+  neighbor 2.2.2.2 soft-reconfiguration inbound
+ exit-address-family
+!
+ip route 2.2.2.2 255.255.255.255 10.23.0.2
+!
+end