FRR: convert ospf area range (#6665)

projects/batfish/src/main/java/org/batfish/grammar/cumulus_frr/CumulusFrrConfigurationBuilder.java

@@ -845,10 +845,7 @@ public void exitSiip_address(Siip_addressContext ctx) {
 
   @Override
   public void enterS_router_ospf(S_router_ospfContext ctx) {
-    if (_frr.getOspfProcess() == null) {
-      _frr.setOspfProcess(new OspfProcess());
-    }
-    _currentOspfVrf = _frr.getOspfProcess().getDefaultVrf();
+    _currentOspfVrf = _frr.getOrCreateOspfProcess().getDefaultVrf();
   }
 
   @Override

projects/batfish/src/main/java/org/batfish/representation/cumulus/CumulusConversions.java

@@ -5,7 +5,6 @@
 import static java.util.Collections.singletonList;
 import static java.util.stream.Collectors.groupingBy;
 import static java.util.stream.Collectors.mapping;
-import static org.batfish.common.util.CollectionUtil.toImmutableSortedMap;
 import static org.batfish.datamodel.Configuration.DEFAULT_VRF_NAME;
 import static org.batfish.datamodel.MultipathEquivalentAsPathMatchMode.EXACT_PATH;
 import static org.batfish.datamodel.MultipathEquivalentAsPathMatchMode.PATH_LENGTH;
@@ -24,6 +23,7 @@
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.ImmutableSortedMap;
 import com.google.common.collect.ImmutableSortedSet;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Sets;
@@ -82,6 +82,7 @@
 import org.batfish.datamodel.bgp.community.Community;
 import org.batfish.datamodel.bgp.community.ExtendedCommunity;
 import org.batfish.datamodel.ospf.OspfArea;
+import org.batfish.datamodel.ospf.OspfAreaSummary;
 import org.batfish.datamodel.ospf.OspfInterfaceSettings;
 import org.batfish.datamodel.ospf.OspfMetricType;
 import org.batfish.datamodel.routing_policy.Common;
@@ -202,6 +203,10 @@ public static String computeOspfExportPolicyName(String vrfName) {
     return String.format("~OSPF_EXPORT_POLICY:%s~", vrfName);
   }
 
+  public static String computeOspfAreaRangeFilterName(String vrfName, long area) {
+    return String.format("~OSPF_AREA_RANGE:%s:%s~", vrfName, area);
+  }
+
   /**
    * Infers the peer Ip for the interface. This is doable only if the interface has exactly one
    * (primary) address that is a /30 or /31. For a /30, the address must NOT be the first or last
@@ -1282,7 +1287,7 @@ static org.batfish.datamodel.ospf.OspfProcess toOspfProcess(
     }
 
     addOspfInterfaces(vsConfig, vrfInterfaces, proc.getProcessId(), w);
-    proc.setAreas(computeOspfAreas(vsConfig, vrfInterfaces.keySet()));
+    proc.setAreas(computeOspfAreas(c, vsConfig, ospfVrf, vrfInterfaces.keySet()));
 
     // Handle Max Metric Router LSA
     if (firstNonNull(vsConfig.getOspfProcess().getMaxMetricRouterLsa(), Boolean.FALSE)) {
@@ -1425,7 +1430,10 @@ static void addOspfInterfaces(
 
   @VisibleForTesting
   static SortedMap<Long, OspfArea> computeOspfAreas(
-      CumulusConcatenatedConfiguration vsConfig, Collection<String> vrfIfaceNames) {
+      Configuration c,
+      CumulusConcatenatedConfiguration vsConfig,
+      OspfVrf ospfVrf,
+      Collection<String> vrfIfaceNames) {
     Map<Long, List<String>> areaInterfaces =
         vrfIfaceNames.stream()
             .filter(
@@ -1438,10 +1446,60 @@ static SortedMap<Long, OspfArea> computeOspfAreas(
                     iface -> vsConfig.getOspfInterface(iface).get().getOspfArea(),
                     mapping(Function.identity(), Collectors.toList())));
 
-    return toImmutableSortedMap(
-        areaInterfaces,
-        Entry::getKey,
-        e -> OspfArea.builder().setNumber(e.getKey()).addInterfaces(e.getValue()).build());
+    // Ensure that the VRF-level OSPF config has each area used.
+    areaInterfaces.keySet().forEach(ospfVrf::getOrCreateArea);
+
+    // Now convert each area
+    ImmutableSortedMap.Builder<Long, OspfArea> areas = ImmutableSortedMap.naturalOrder();
+    ospfVrf
+        .getAreas()
+        .values()
+        .forEach(
+            vrfArea -> {
+              long num = vrfArea.getArea();
+              List<String> interfaces = areaInterfaces.get(num);
+              if (interfaces.isEmpty()) {
+                // No interfaces, skip area.
+                return;
+              }
+              OspfArea area = convertArea(c, ospfVrf.getVrfName(), vrfArea, interfaces);
+              areas.put(area.getAreaNumber(), area);
+            });
+    return areas.build();
+  }
+
+  private static @Nonnull OspfArea convertArea(
+      Configuration c,
+      String vrfName,
+      org.batfish.representation.cumulus.OspfArea vsArea,
+      Collection<String> interfaces) {
+    OspfArea.Builder ret = OspfArea.builder().setNumber(vsArea.getArea()).addInterfaces(interfaces);
+
+    // Handle OSPF Area Range conversion into VI OspfAreaSummary. It has two steps:
+    // 1. convert OspfAreaRange to OspfAreaSummary
+    // 2. add a RouteFilterList to force summarization and block more specific routes.
+    if (!vsArea.getRanges().isEmpty()) {
+      ImmutableList.Builder<RouteFilterLine> lines =
+          ImmutableList.builderWithExpectedSize(vsArea.getRanges().size() + 1);
+      for (OspfAreaRange range : vsArea.getRanges().values()) {
+        // OSPF costs are only 16-bit, but the VI metric is a long, for other protocols that support
+        // that. Upconvert if not null.
+        Prefix prefix = range.getRange();
+        Long cost = range.getCost() == null ? null : range.getCost().longValue();
+        OspfAreaSummary summary = new OspfAreaSummary(true, cost);
+        ret.addSummary(prefix, summary);
+        lines.add(new RouteFilterLine(LineAction.DENY, PrefixRange.moreSpecificThan(prefix)));
+      }
+      // Anything not summarized is permitted.
+      lines.add(new RouteFilterLine(LineAction.PERMIT, PrefixRange.ALL));
+      RouteFilterList summaryFilter =
+          new RouteFilterList(
+              computeOspfAreaRangeFilterName(vrfName, vsArea.getArea()), lines.build());
+      c.getRouteFilterLists().put(summaryFilter.getName(), summaryFilter);
+      ret.setSummaryFilter(summaryFilter.getName());
+    }
+
+    return ret.build();
   }
 
   @Nullable

projects/batfish/src/main/java/org/batfish/representation/cumulus/CumulusFrrConfiguration.java

@@ -64,6 +64,13 @@ public void setBgpProcess(@Nullable BgpProcess bgpProcess) {
     _bgpProcess = bgpProcess;
   }
 
+  public @Nonnull OspfProcess getOrCreateOspfProcess() {
+    if (_ospfProcess == null) {
+      _ospfProcess = new OspfProcess();
+    }
+    return _ospfProcess;
+  }
+
   @Nullable
   public OspfProcess getOspfProcess() {
     return _ospfProcess;

projects/batfish/src/main/java/org/batfish/representation/cumulus/OspfVrf.java

@@ -1,6 +1,7 @@
 package org.batfish.representation.cumulus;
 
 import java.io.Serializable;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 import javax.annotation.Nonnull;
@@ -27,6 +28,10 @@ public OspfVrf(String name) {
     return _areas.get(area);
   }
 
+  public @Nonnull Map<Long, OspfArea> getAreas() {
+    return Collections.unmodifiableMap(_areas);
+  }
+
   @Nullable
   public Ip getRouterId() {
     return _routerId;

projects/batfish/src/test/java/org/batfish/grammar/cumulus_frr/CumulusFrrGrammarTest.java

@@ -8,6 +8,7 @@
 import static org.batfish.datamodel.matchers.MapMatchers.hasKeys;
 import static org.batfish.datamodel.routing_policy.Environment.Direction.OUT;
 import static org.batfish.grammar.cumulus_frr.CumulusFrrConfigurationBuilder.nextMultipleOfFive;
+import static org.batfish.representation.cumulus.CumulusConversions.computeOspfAreaRangeFilterName;
 import static org.batfish.representation.cumulus.CumulusRoutingProtocol.CONNECTED;
 import static org.batfish.representation.cumulus.CumulusRoutingProtocol.OSPF;
 import static org.batfish.representation.cumulus.CumulusRoutingProtocol.STATIC;
@@ -21,6 +22,7 @@
 import static org.batfish.representation.cumulus.CumulusStructureUsage.ROUTE_MAP_MATCH_COMMUNITY_LIST;
 import static org.hamcrest.Matchers.aMapWithSize;
 import static org.hamcrest.Matchers.allOf;
+import static org.hamcrest.Matchers.anEmptyMap;
 import static org.hamcrest.Matchers.contains;
 import static org.hamcrest.Matchers.containsInAnyOrder;
 import static org.hamcrest.Matchers.containsString;
@@ -77,11 +79,14 @@
 import org.batfish.datamodel.OriginType;
 import org.batfish.datamodel.OspfExternalType2Route;
 import org.batfish.datamodel.Prefix;
+import org.batfish.datamodel.RouteFilterList;
 import org.batfish.datamodel.RoutingProtocol;
 import org.batfish.datamodel.StaticRoute.Builder;
 import org.batfish.datamodel.SubRange;
 import org.batfish.datamodel.answers.ConvertConfigurationAnswerElement;
 import org.batfish.datamodel.bgp.community.StandardCommunity;
+import org.batfish.datamodel.ospf.OspfAreaSummary;
+import org.batfish.datamodel.ospf.OspfProcess;
 import org.batfish.datamodel.routing_policy.RoutingPolicy;
 import org.batfish.datamodel.routing_policy.expr.LiteralLong;
 import org.batfish.grammar.BatfishParseTreeWalker;
@@ -1888,6 +1893,48 @@ public void testRouterOspfAreaRange() {
     assertThat(area5.getRange(prefix).getCost(), nullValue());
   }
 
+  @Test
+  public void testRouterOspfAreaRangeConversion() {
+    parse(
+        "interface swp1\n"
+            + " ip address 1.2.3.4/5\n"
+            + " ip ospf area 1.1.1.0\n"
+            + "\n"
+            + "interface swp2\n"
+            + " ip address 2.3.4.5/6\n"
+            + " ip ospf area 5\n"
+            + "\n"
+            + "router ospf\n"
+            + " area 1.1.1.0 range 1.255.0.0/17 cost 10\n");
+    long area1110 = Ip.parse("1.1.1.0").asLong();
+    Configuration c = _config.toVendorIndependentConfigurations().get(0);
+    assertThat(c.getDefaultVrf().getOspfProcesses(), aMapWithSize(1));
+    OspfProcess proc = Iterables.getOnlyElement(c.getDefaultVrf().getOspfProcesses().values());
+    assertThat(proc.getAreas(), hasKeys(5L, area1110));
+    {
+      org.batfish.datamodel.ospf.OspfArea area = proc.getAreas().get(5L);
+      assertThat(area.getSummaries(), anEmptyMap());
+      assertThat(area.getSummaryFilter(), nullValue());
+    }
+    {
+      org.batfish.datamodel.ospf.OspfArea area = proc.getAreas().get(area1110);
+      assertThat(area.getSummaries(), hasKeys(Prefix.parse("1.255.0.0/17")));
+      OspfAreaSummary summary = Iterables.getOnlyElement(area.getSummaries().values());
+      assertThat(summary.getAdvertised(), equalTo(true));
+      assertThat(summary.getMetric(), equalTo(10L));
+      String name = computeOspfAreaRangeFilterName(c.getDefaultVrf().getName(), area1110);
+      assertThat(area.getSummaryFilter(), equalTo(name));
+      assertThat(c.getRouteFilterLists(), hasKey(name));
+      RouteFilterList filter = c.getRouteFilterLists().get(name);
+      assertTrue(filter.permits(Prefix.parse("1.255.0.0/17"))); // prefix itself should be permitted
+      assertFalse(
+          filter.permits(
+              Prefix.parse("1.255.64.0/18"))); // more specific, even with diff prefix, denied
+      assertTrue(filter.permits(Prefix.parse("10.0.0.0/18"))); // more specific, not overlapping
+      assertTrue(filter.permits(Prefix.parse("1.255.0.0/16"))); // less specific
+    }
+  }
+
   @Test
   public void testRouterOspfNetwork() {
     parse(

projects/batfish/src/test/java/org/batfish/representation/cumulus/CumulusConversionsTest.java

@@ -1766,9 +1766,12 @@ public void testComputeOspfProcess_HasArea() {
         .getOrCreateInterface("iface")
         .getOrCreateOspf()
         .setOspfArea(1L);
+    OspfVrf vsVrf =
+        concatenatedConfiguration.getFrrConfiguration().getOrCreateOspfProcess().getDefaultVrf();
+    Configuration c = new Configuration("c", ConfigurationFormat.CUMULUS_CONCATENATED);
 
     SortedMap<Long, OspfArea> areas =
-        computeOspfAreas(concatenatedConfiguration, ImmutableList.of("iface"));
+        computeOspfAreas(c, concatenatedConfiguration, vsVrf, ImmutableList.of("iface"));
     assertThat(
         areas,
         equalTo(
@@ -1781,19 +1784,25 @@ public void testComputeOspfProcess_NoArea() {
     CumulusConcatenatedConfiguration concatenatedConfiguration =
         new CumulusConcatenatedConfiguration();
     concatenatedConfiguration.getFrrConfiguration().getOrCreateInterface("iface").getOrCreateOspf();
+    OspfVrf vsVrf =
+        concatenatedConfiguration.getFrrConfiguration().getOrCreateOspfProcess().getDefaultVrf();
+    Configuration c = new Configuration("c", ConfigurationFormat.CUMULUS_CONCATENATED);
 
     SortedMap<Long, OspfArea> areas =
-        computeOspfAreas(concatenatedConfiguration, ImmutableList.of("iface"));
+        computeOspfAreas(c, concatenatedConfiguration, vsVrf, ImmutableList.of("iface"));
     assertThat(areas, equalTo(ImmutableSortedMap.of()));
   }
 
   @Test
   public void testComputeOspfProcess_NoInterface() {
     CumulusConcatenatedConfiguration concatenatedConfiguration =
         new CumulusConcatenatedConfiguration();
+    OspfVrf vsVrf =
+        concatenatedConfiguration.getFrrConfiguration().getOrCreateOspfProcess().getDefaultVrf();
+    Configuration c = new Configuration("c", ConfigurationFormat.CUMULUS_CONCATENATED);
 
     SortedMap<Long, OspfArea> areas =
-        computeOspfAreas(concatenatedConfiguration, ImmutableList.of("iface"));
+        computeOspfAreas(c, concatenatedConfiguration, vsVrf, ImmutableList.of("iface"));
     assertThat(areas, equalTo(ImmutableSortedMap.of()));
   }