EIGRP: add metric version and plumb throughout (#6532)

Different implementations of EIGRP compute the cost with greater and lesser
degrees of precision. Add a setting to each EIGRP process to indicate which
cost implementation it uses, and add the classic metric computations for NX-OS.

projects/batfish-common-protocol/src/main/java/org/batfish/datamodel/EigrpExternalRoute.java

@@ -2,7 +2,6 @@
 
 import static com.google.common.base.Preconditions.checkArgument;
 import static java.util.Objects.hash;
-import static java.util.Objects.requireNonNull;
 
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;
@@ -11,6 +10,7 @@
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 import org.batfish.datamodel.eigrp.EigrpMetric;
+import org.batfish.datamodel.eigrp.EigrpMetricVersion;
 
 /** Represents an external EIGRP route */
 public class EigrpExternalRoute extends EigrpRoute {
@@ -28,11 +28,21 @@ private EigrpExternalRoute(
       long destinationAsn,
       @Nullable Ip nextHopIp,
       @Nonnull EigrpMetric metric,
+      @Nonnull EigrpMetricVersion metricVersion,
       long processAsn,
       long tag,
       boolean nonForwarding,
       boolean nonRouting) {
-    super(admin, network, nextHopIp, metric, processAsn, tag, nonForwarding, nonRouting);
+    super(
+        admin,
+        network,
+        nextHopIp,
+        metric,
+        metricVersion,
+        processAsn,
+        tag,
+        nonForwarding,
+        nonRouting);
     _destinationAsn = destinationAsn;
   }
 
@@ -43,15 +53,26 @@ private static EigrpExternalRoute create(
       @Nullable @JsonProperty(PROP_NETWORK) Prefix network,
       @Nullable @JsonProperty(PROP_NEXT_HOP_IP) Ip nextHopIp,
       @Nullable @JsonProperty(PROP_EIGRP_METRIC) EigrpMetric metric,
+      @Nullable @JsonProperty(PROP_EIGRP_METRIC_VERSION) EigrpMetricVersion metricVersion,
       @Nullable @JsonProperty(PROP_PROCESS_ASN) Long processAsn,
       @Nullable @JsonProperty(PROP_TAG) Long tag) {
     checkArgument(admin != null, "EIGRP route: missing %s", PROP_ADMINISTRATIVE_COST);
     checkArgument(destinationAsn != null, "EIGRP route: missing %s", PROP_DESTINATION_ASN);
     checkArgument(metric != null, "EIGRP route: missing %s", PROP_EIGRP_METRIC);
+    checkArgument(metricVersion != null, "EIGRP route: missing %s", PROP_EIGRP_METRIC_VERSION);
     checkArgument(processAsn != null, "EIGRP route: missing %s", PROP_PROCESS_ASN);
     checkArgument(tag != null, "EIGRP route: missing %s", PROP_TAG);
     return new EigrpExternalRoute(
-        network, admin, destinationAsn, nextHopIp, metric, processAsn, tag, false, false);
+        network,
+        admin,
+        destinationAsn,
+        nextHopIp,
+        metric,
+        metricVersion,
+        processAsn,
+        tag,
+        false,
+        false);
   }
 
   @JsonProperty(PROP_DESTINATION_ASN)
@@ -79,13 +100,16 @@ public EigrpExternalRoute build() {
       checkArgument(getNetwork() != null, "EIGRP route: missing %s", PROP_NETWORK);
       checkArgument(_destinationAsn != null, "EIGRP route: missing %s", PROP_DESTINATION_ASN);
       checkArgument(_eigrpMetric != null, "EIGRP route: missing %s", PROP_EIGRP_METRIC);
+      checkArgument(
+          _eigrpMetricVersion != null, "EIGRP route: missing %s", PROP_EIGRP_METRIC_VERSION);
       checkArgument(_processAsn != null, "EIGRP route: missing %s", PROP_PROCESS_ASN);
       return new EigrpExternalRoute(
           getNetwork(),
           getAdmin(),
           _destinationAsn,
           getNextHopIp(),
-          requireNonNull(_eigrpMetric),
+          _eigrpMetric,
+          _eigrpMetricVersion,
           _processAsn,
           getTag(),
           getNonForwarding(),
@@ -115,6 +139,7 @@ public Builder toBuilder() {
         // EigrpExternalRoute properties
         .setDestinationAsn(getDestinationAsn())
         .setEigrpMetric(getEigrpMetric())
+        .setEigrpMetricVersion(getEigrpMetricVersion())
         .setProcessAsn(getProcessAsn());
   }
 
@@ -130,6 +155,7 @@ public boolean equals(Object obj) {
     return _admin == rhs._admin
         && Objects.equals(_destinationAsn, rhs._destinationAsn)
         && _metric.equals(rhs._metric)
+        && _metricVersion == rhs._metricVersion
         && _network.equals(rhs._network)
         && _nextHopIp.equals(rhs._nextHopIp)
         && _processAsn == rhs._processAsn
@@ -149,6 +175,7 @@ public final int hashCode() {
         getNonRouting(),
         _destinationAsn,
         _metric,
+        _metricVersion,
         _processAsn);
   }
 

projects/batfish-common-protocol/src/main/java/org/batfish/datamodel/EigrpInternalRoute.java

@@ -9,6 +9,7 @@
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 import org.batfish.datamodel.eigrp.EigrpMetric;
+import org.batfish.datamodel.eigrp.EigrpMetricVersion;
 
 /** Represents an internal EIGRP route */
 public class EigrpInternalRoute extends EigrpRoute {
@@ -19,10 +20,20 @@ private EigrpInternalRoute(
       @Nullable Prefix network,
       @Nullable Ip nextHopIp,
       @Nonnull EigrpMetric metric,
+      @Nonnull EigrpMetricVersion metricVersion,
       long tag,
       boolean nonForwarding,
       boolean nonRouting) {
-    super(admin, network, nextHopIp, metric, processAsn, tag, nonForwarding, nonRouting);
+    super(
+        admin,
+        network,
+        nextHopIp,
+        metric,
+        metricVersion,
+        processAsn,
+        tag,
+        nonForwarding,
+        nonRouting);
   }
 
   @JsonCreator
@@ -32,12 +43,15 @@ private static EigrpInternalRoute create(
       @Nullable @JsonProperty(PROP_NETWORK) Prefix network,
       @Nullable @JsonProperty(PROP_NEXT_HOP_IP) Ip nextHopIp,
       @Nullable @JsonProperty(PROP_EIGRP_METRIC) EigrpMetric metric,
+      @Nullable @JsonProperty(PROP_EIGRP_METRIC_VERSION) EigrpMetricVersion metricVersion,
       @Nullable @JsonProperty(PROP_TAG) Long tag) {
-    checkArgument(admin != null, "EIGRP rooute: missing %s", PROP_ADMINISTRATIVE_COST);
+    checkArgument(admin != null, "EIGRP route: missing %s", PROP_ADMINISTRATIVE_COST);
     checkArgument(metric != null, "EIGRP route: missing %s", PROP_EIGRP_METRIC);
+    checkArgument(metricVersion != null, "EIGRP route: missing %s", PROP_EIGRP_METRIC_VERSION);
     checkArgument(processAsn != null, "EIGRP route: missing %s", PROP_PROCESS_ASN);
     checkArgument(tag != null, "EIGRP route: missing %s", PROP_TAG);
-    return new EigrpInternalRoute(admin, processAsn, network, nextHopIp, metric, tag, false, false);
+    return new EigrpInternalRoute(
+        admin, processAsn, network, nextHopIp, metric, metricVersion, tag, false, false);
   }
 
   public static Builder builder() {
@@ -58,6 +72,8 @@ private Builder() {}
     public EigrpInternalRoute build() {
       checkArgument(getNetwork() != null, "EIGRP route: missing %s", PROP_NETWORK);
       checkArgument(_eigrpMetric != null, "EIGRP route: missing %s", PROP_EIGRP_METRIC);
+      checkArgument(
+          _eigrpMetricVersion != null, "EIGRP route: missing %s", PROP_EIGRP_METRIC_VERSION);
       checkArgument(_processAsn != null, "EIGRP route: missing %s", PROP_PROCESS_ASN);
       checkArgument(
           getMetric() == 0, "EIGRP route: cannot set metric directly, use setEigrpMetric instead");
@@ -67,6 +83,7 @@ public EigrpInternalRoute build() {
           getNetwork(),
           getNextHopIp(),
           _eigrpMetric,
+          _eigrpMetricVersion,
           getTag(),
           getNonForwarding(),
           getNonRouting());
@@ -94,6 +111,7 @@ public Builder toBuilder() {
         .setNonRouting(getNonRouting())
         // EigrpInternalRoute properties
         .setEigrpMetric(getEigrpMetric())
+        .setEigrpMetricVersion(getEigrpMetricVersion())
         .setProcessAsn(getProcessAsn());
   }
 
@@ -113,6 +131,7 @@ public boolean equals(Object obj) {
         && _tag == rhs._tag
         && _processAsn == rhs._processAsn
         && _metric.equals(rhs._metric)
+        && _metricVersion == rhs._metricVersion
         && getNonForwarding() == rhs.getNonForwarding()
         && getNonRouting() == rhs.getNonRouting();
   }
@@ -126,6 +145,7 @@ public final int hashCode() {
         _tag,
         _processAsn,
         _metric,
+        _metricVersion,
         getNonForwarding(),
         getNonRouting());
   }

projects/batfish-common-protocol/src/main/java/org/batfish/datamodel/EigrpRoute.java

@@ -1,23 +1,25 @@
 package org.batfish.datamodel;
 
 import static com.google.common.base.MoreObjects.firstNonNull;
-import static com.google.common.base.Preconditions.checkArgument;
 
 import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.google.common.primitives.UnsignedLong;
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 import org.batfish.datamodel.eigrp.EigrpMetric;
+import org.batfish.datamodel.eigrp.EigrpMetricVersion;
 
 /** Represents an EIGRP route, internal or external */
 public abstract class EigrpRoute extends AbstractRoute {
 
   static final String PROP_EIGRP_METRIC = "eigrp-metric";
+  static final String PROP_EIGRP_METRIC_VERSION = "eigrp-metric-version";
   static final String PROP_PROCESS_ASN = "process-asn";
 
   protected final int _admin;
   @Nonnull protected final EigrpMetric _metric;
+  @Nonnull protected final EigrpMetricVersion _metricVersion;
   @Nonnull protected final Ip _nextHopIp;
 
   /** AS number of the EIGRP process that installed this route in the RIB */
@@ -27,22 +29,23 @@ public abstract class EigrpRoute extends AbstractRoute {
       int admin,
       Prefix network,
       @Nullable Ip nextHopIp,
-      @Nullable EigrpMetric metric,
+      @Nonnull EigrpMetric metric,
+      @Nonnull EigrpMetricVersion metricVersion,
       long processAsn,
       long tag,
       boolean nonForwarding,
       boolean nonRouting) {
     super(network, admin, tag, nonRouting, nonForwarding);
-    checkArgument(metric != null, "Cannot create EIGRP route: missing %s", PROP_EIGRP_METRIC);
     _admin = admin;
     _metric = metric;
+    _metricVersion = metricVersion;
     _nextHopIp = firstNonNull(nextHopIp, Route.UNSET_ROUTE_NEXT_HOP_IP);
     _processAsn = processAsn;
   }
 
   @JsonIgnore
   public final UnsignedLong getCompositeCost() {
-    return _metric.cost();
+    return _metric.cost(_metricVersion);
   }
 
   @JsonProperty(PROP_EIGRP_METRIC)
@@ -51,9 +54,15 @@ public final EigrpMetric getEigrpMetric() {
     return _metric;
   }
 
+  @JsonProperty(PROP_EIGRP_METRIC_VERSION)
+  @Nonnull
+  public final EigrpMetricVersion getEigrpMetricVersion() {
+    return _metricVersion;
+  }
+
   @Override
   public final Long getMetric() {
-    return _metric.ribMetric();
+    return _metric.ribMetric(_metricVersion);
   }
 
   @Nonnull
@@ -82,6 +91,7 @@ public abstract static class Builder<B extends Builder<B, R>, R extends EigrpRou
       extends AbstractRouteBuilder<B, R> {
     @Nullable protected Long _destinationAsn;
     @Nullable protected EigrpMetric _eigrpMetric;
+    @Nullable protected EigrpMetricVersion _eigrpMetricVersion;
     @Nullable protected Long _processAsn;
 
     public B setDestinationAsn(@Nonnull Long destinationAsn) {
@@ -94,6 +104,11 @@ public B setEigrpMetric(@Nonnull EigrpMetric metric) {
       return getThis();
     }
 
+    public B setEigrpMetricVersion(@Nonnull EigrpMetricVersion version) {
+      _eigrpMetricVersion = version;
+      return getThis();
+    }
+
     public B setProcessAsn(@Nullable Long processAsn) {
       _processAsn = processAsn;
       return getThis();

projects/batfish-common-protocol/src/main/java/org/batfish/datamodel/eigrp/ClassicMetric.java

@@ -77,7 +77,18 @@ public short getK5() {
   }
 
   @Override
-  public UnsignedLong cost() {
+  public UnsignedLong cost(EigrpMetricVersion version) {
+    switch (version) {
+      case V1:
+        return costV1();
+      case V2:
+        return costV2();
+      default:
+        throw new IllegalArgumentException("Unsupported version " + version);
+    }
+  }
+
+  private UnsignedLong costV1() {
     checkState(_values.getBandwidth() != null, "Cannot calculate cost before bandwidth is set");
     long scaledBw = BANDWIDTH_FACTOR / _values.getBandwidth();
     long metric =
@@ -93,9 +104,24 @@ public UnsignedLong cost() {
     return UnsignedLong.valueOf(metric);
   }
 
+  private UnsignedLong costV2() {
+    checkState(_values.getBandwidth() != null, "Cannot calculate cost before bandwidth is set");
+    long scaledBw = 256L * BANDWIDTH_FACTOR / _values.getBandwidth();
+    long metricBw = (_k1 * scaledBw) + (_k2 * scaledBw) / (256 - _values.getEffectiveBandwidth());
+    long metricDelay =
+        // Scale delay from picoseconds to 10s of microseconds
+        // Do that first, to avoid overflow
+        256L * _k3 * (_values.getDelay() / PICO_TO_TENS_OF_MS_FACTOR);
+    long metric = metricBw + metricDelay;
+    if (_k5 != 0) {
+      metric = metric * ((long) _k5 / ((long) _values.getReliability() + _k4));
+    }
+    return UnsignedLong.valueOf(metric);
+  }
+
   @Override
-  public long ribMetric() {
-    return cost().longValue();
+  public long ribMetric(EigrpMetricVersion version) {
+    return cost(version).longValue();
   }
 
   @Override

projects/batfish-common-protocol/src/main/java/org/batfish/datamodel/eigrp/EigrpMetric.java

@@ -13,14 +13,14 @@
 })
 public interface EigrpMetric extends Serializable {
 
-  /** Return metric as a single value, used for route preference tie breaking. */
-  UnsignedLong cost();
+  /** Return the metric as a single value, used for route preference tie breaking. */
+  UnsignedLong cost(EigrpMetricVersion version);
 
   /**
-   * Return metric as a single value, scaled as needed to fit into a 4-byte value. Used for route
-   * preference tie breaking.
+   * Return metric as a single value, scaled as needed to fit into a 4-byte value. Used as a metric
+   * expected to be seen in the main RIB.
    */
-  long ribMetric();
+  long ribMetric(EigrpMetricVersion version);
 
   /**
    * Check if this metric and {@code other} are compatible, i.e., have the same type and k values

projects/batfish-common-protocol/src/main/java/org/batfish/datamodel/eigrp/EigrpMetricVersion.java

@@ -0,0 +1,13 @@
+package org.batfish.datamodel.eigrp;
+
+/**
+ * Identifies how to summarize an {@link EigrpMetric} as a single value.
+ *
+ * <p>Is implementation-dependent. E.g., IOS-XE uses V1 and NX-OS uses V2.
+ */
+public enum EigrpMetricVersion {
+  /** IOS-XE -like. */
+  V1,
+  /** NX-OS -like. Higher precision than IOS-XE. */
+  V2,
+}