calculate subscribed subnet from node id

data/provider/src/main/java/tech/pegasys/teku/api/GetSpecResponse.java

@@ -42,7 +42,6 @@ public Map<String, String> getConfigMap() {
 
     configAttributes.put("BLS_WITHDRAWAL_PREFIX", getBlsWithdrawalPrefix().toHexString());
     configAttributes.put("TARGET_AGGREGATORS_PER_COMMITTEE", getTargetAggregatorsPerCommittee());
-    configAttributes.put("RANDOM_SUBNETS_PER_VALIDATOR", getRandomSubnetsPerValidator());
     configAttributes.put("SUBNETS_PER_NODE", getSubnetsPerNode());
     configAttributes.put(
         "EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION", getEpochsPerRandomSubnetSubscription());
@@ -106,10 +105,6 @@ private String getMaxRequestBlocks() {
     return Integer.toString(specConfig.getNetworkingConfig().getMaxRequestBlocks());
   }
 
-  private String getRandomSubnetsPerValidator() {
-    return Integer.toString(ValidatorConstants.RANDOM_SUBNETS_PER_VALIDATOR);
-  }
-
   private String getTtfbTimeout() {
     return Integer.toString(specConfig.getNetworkingConfig().getTtfbTimeout());
   }

ethereum/networks/src/test/resources/tech/pegasys/teku/networks/test-constants.yaml

@@ -40,8 +40,6 @@ SAFE_SLOTS_TO_UPDATE_JUSTIFIED: 2
 ETH1_FOLLOW_DISTANCE: 16
 # 2**4 (= 16)
 TARGET_AGGREGATORS_PER_COMMITTEE: 16
-# 2**0 (= 1)
-RANDOM_SUBNETS_PER_VALIDATOR: 1
 # 2**8 (= 256)
 EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION: 256
 # 14 (estimate from Eth1 mainnet)

ethereum/spec/src/main/java/tech/pegasys/teku/spec/config/SpecConfigReader.java

@@ -75,7 +75,6 @@ public class SpecConfigReader {
           // Phase0 constants which may exist in legacy config files, but should now be ignored
           "BLS_WITHDRAWAL_PREFIX",
           "TARGET_AGGREGATORS_PER_COMMITTEE",
-          "RANDOM_SUBNETS_PER_VALIDATOR",
           "EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION",
           "DOMAIN_BEACON_PROPOSER",
           "DOMAIN_BEACON_ATTESTER",

ethereum/spec/src/main/java/tech/pegasys/teku/spec/constants/ValidatorConstants.java

@@ -16,7 +16,7 @@
 public class ValidatorConstants {
   // Phase0
   public static final int TARGET_AGGREGATORS_PER_COMMITTEE = 16;
-  public static final int RANDOM_SUBNETS_PER_VALIDATOR = 1;
+  public static final int NODE_ID_BITS = 256;
   // Altair
   public static final int TARGET_AGGREGATORS_PER_SYNC_SUBCOMMITTEE = 16;
 }

ethereum/spec/src/main/resources/tech/pegasys/teku/spec/config/configs/chiado.yaml

@@ -49,8 +49,6 @@ SAFE_SLOTS_TO_UPDATE_JUSTIFIED: 8
 ETH1_FOLLOW_DISTANCE: 1024
 # 2**4 (= 16)
 TARGET_AGGREGATORS_PER_COMMITTEE: 16
-# 2**0 (= 1)
-RANDOM_SUBNETS_PER_VALIDATOR: 1
 # 2**8 (= 256)
 EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION: 256
 # 6 (estimate from xDai mainnet)

ethereum/spec/src/test/resources/tech/pegasys/teku/spec/config/altairForkSpec.json

@@ -65,7 +65,6 @@
   "PROPORTIONAL_SLASHING_MULTIPLIER_ALTAIR": "2",
   "PROPOSER_REWARD_QUOTIENT": "8",
   "PROPOSER_SCORE_BOOST": "70",
-  "RANDOM_SUBNETS_PER_VALIDATOR": "1",
   "SAFE_SLOTS_TO_UPDATE_JUSTIFIED": "8",
   "SECONDS_PER_ETH1_BLOCK": "14",
   "SECONDS_PER_SLOT": "12",

ethereum/spec/src/test/resources/tech/pegasys/teku/spec/config/bellatrixForkSpec.json

@@ -70,7 +70,6 @@
   "PROPORTIONAL_SLASHING_MULTIPLIER_BELLATRIX": "3",
   "PROPOSER_REWARD_QUOTIENT": "8",
   "PROPOSER_SCORE_BOOST": "70",
-  "RANDOM_SUBNETS_PER_VALIDATOR": "1",
   "SAFE_SLOTS_TO_UPDATE_JUSTIFIED": "8",
   "SECONDS_PER_ETH1_BLOCK": "14",
   "SECONDS_PER_SLOT": "12",

ethereum/spec/src/test/resources/tech/pegasys/teku/spec/config/invalid/invalidBytes4_tooLarge.yaml

@@ -36,8 +36,6 @@ SAFE_SLOTS_TO_UPDATE_JUSTIFIED: 8
 ETH1_FOLLOW_DISTANCE: 2048
 # 2**4 (= 16)
 TARGET_AGGREGATORS_PER_COMMITTEE: 16
-# 2**0 (= 1)
-RANDOM_SUBNETS_PER_VALIDATOR: 1
 # 2**8 (= 256)
 EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION: 256
 # 14 (estimate from Eth1 mainnet)

ethereum/spec/src/test/resources/tech/pegasys/teku/spec/config/invalid/invalidBytes4_tooSmall.yaml

@@ -36,8 +36,6 @@ SAFE_SLOTS_TO_UPDATE_JUSTIFIED: 8
 ETH1_FOLLOW_DISTANCE: 2048
 # 2**4 (= 16)
 TARGET_AGGREGATORS_PER_COMMITTEE: 16
-# 2**0 (= 1)
-RANDOM_SUBNETS_PER_VALIDATOR: 1
 # 2**8 (= 256)
 EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION: 256
 # 14 (estimate from Eth1 mainnet)

ethereum/spec/src/test/resources/tech/pegasys/teku/spec/config/invalid/invalidInteger_negative.yaml

@@ -36,8 +36,6 @@ SAFE_SLOTS_TO_UPDATE_JUSTIFIED: 8
 ETH1_FOLLOW_DISTANCE: 2048
 # 2**4 (= 16)
 TARGET_AGGREGATORS_PER_COMMITTEE: 16
-# 2**0 (= 1)
-RANDOM_SUBNETS_PER_VALIDATOR: 1
 # 2**8 (= 256)
 EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION: 256
 # 14 (estimate from Eth1 mainnet)

ethereum/spec/src/test/resources/tech/pegasys/teku/spec/config/invalid/invalidInteger_tooLarge.yaml

@@ -36,8 +36,6 @@ SAFE_SLOTS_TO_UPDATE_JUSTIFIED: 8
 ETH1_FOLLOW_DISTANCE: 2048
 # 2**4 (= 16)
 TARGET_AGGREGATORS_PER_COMMITTEE: 16
-# 2**0 (= 1)
-RANDOM_SUBNETS_PER_VALIDATOR: 1
 # 2**8 (= 256)
 EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION: 256
 # 14 (estimate from Eth1 mainnet)

ethereum/spec/src/test/resources/tech/pegasys/teku/spec/config/invalid/invalidInteger_wrongType.yaml

@@ -36,8 +36,6 @@ SAFE_SLOTS_TO_UPDATE_JUSTIFIED: 8
 ETH1_FOLLOW_DISTANCE: 2048
 # 2**4 (= 16)
 TARGET_AGGREGATORS_PER_COMMITTEE: 16
-# 2**0 (= 1)
-RANDOM_SUBNETS_PER_VALIDATOR: 1
 # 2**8 (= 256)
 EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION: 256
 # 14 (estimate from Eth1 mainnet)

ethereum/spec/src/test/resources/tech/pegasys/teku/spec/config/invalid/invalidLong_negative.yaml

@@ -36,8 +36,6 @@ SAFE_SLOTS_TO_UPDATE_JUSTIFIED: 8
 ETH1_FOLLOW_DISTANCE: 2048
 # 2**4 (= 16)
 TARGET_AGGREGATORS_PER_COMMITTEE: 16
-# 2**0 (= 1)
-RANDOM_SUBNETS_PER_VALIDATOR: 1
 # 2**8 (= 256)
 EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION: 256
 # 14 (estimate from Eth1 mainnet)

ethereum/spec/src/test/resources/tech/pegasys/teku/spec/config/invalid/invalidLong_tooLarge.yaml

@@ -36,8 +36,6 @@ SAFE_SLOTS_TO_UPDATE_JUSTIFIED: 8
 ETH1_FOLLOW_DISTANCE: 2048
 # 2**4 (= 16)
 TARGET_AGGREGATORS_PER_COMMITTEE: 16
-# 2**0 (= 1)
-RANDOM_SUBNETS_PER_VALIDATOR: 1
 # 2**8 (= 256)
 EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION: 256
 # 14 (estimate from Eth1 mainnet)

ethereum/spec/src/test/resources/tech/pegasys/teku/spec/config/invalid/invalidLong_wrongType.yaml

@@ -36,8 +36,6 @@ SAFE_SLOTS_TO_UPDATE_JUSTIFIED: 8
 ETH1_FOLLOW_DISTANCE: 2048
 # 2**4 (= 16)
 TARGET_AGGREGATORS_PER_COMMITTEE: 16
-# 2**0 (= 1)
-RANDOM_SUBNETS_PER_VALIDATOR: 1
 # 2**8 (= 256)
 EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION: 256
 # 14 (estimate from Eth1 mainnet)

ethereum/spec/src/test/resources/tech/pegasys/teku/spec/config/invalid/invalidUInt64_negative.yaml

@@ -36,8 +36,6 @@ SAFE_SLOTS_TO_UPDATE_JUSTIFIED: 8
 ETH1_FOLLOW_DISTANCE: 2048
 # 2**4 (= 16)
 TARGET_AGGREGATORS_PER_COMMITTEE: 16
-# 2**0 (= 1)
-RANDOM_SUBNETS_PER_VALIDATOR: 1
 # 2**8 (= 256)
 EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION: 256
 # 14 (estimate from Eth1 mainnet)

ethereum/spec/src/test/resources/tech/pegasys/teku/spec/config/invalid/invalidUInt64_tooLarge.yaml

@@ -36,8 +36,6 @@ SAFE_SLOTS_TO_UPDATE_JUSTIFIED: 8
 ETH1_FOLLOW_DISTANCE: 2048
 # 2**4 (= 16)
 TARGET_AGGREGATORS_PER_COMMITTEE: 16
-# 2**0 (= 1)
-RANDOM_SUBNETS_PER_VALIDATOR: 1
 # 2**8 (= 256)
 EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION: 256
 # 14 (estimate from Eth1 mainnet)

ethereum/spec/src/test/resources/tech/pegasys/teku/spec/config/invalid/missingAltairField.yaml

@@ -90,8 +90,6 @@ SAFE_SLOTS_TO_UPDATE_JUSTIFIED: 2
 ETH1_FOLLOW_DISTANCE: 16
 # 2**4 (= 16)
 TARGET_AGGREGATORS_PER_COMMITTEE: 16
-# 2**0 (= 1)
-RANDOM_SUBNETS_PER_VALIDATOR: 1
 # 2**8 (= 256)
 EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION: 256
 # 14 (estimate from Eth1 mainnet)

ethereum/spec/src/test/resources/tech/pegasys/teku/spec/config/invalid/missingChurnLimit.yaml

@@ -39,8 +39,6 @@ SAFE_SLOTS_TO_UPDATE_JUSTIFIED: 8
 ETH1_FOLLOW_DISTANCE: 2048
 # 2**4 (= 16)
 TARGET_AGGREGATORS_PER_COMMITTEE: 16
-# 2**0 (= 1)
-RANDOM_SUBNETS_PER_VALIDATOR: 1
 # 2**8 (= 256)
 EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION: 256
 # 14 (estimate from Eth1 mainnet)

ethereum/spec/src/test/resources/tech/pegasys/teku/spec/config/invalid/unknownField.yaml

@@ -95,8 +95,6 @@ SAFE_SLOTS_TO_UPDATE_JUSTIFIED: 2
 ETH1_FOLLOW_DISTANCE: 16
 # 2**4 (= 16)
 TARGET_AGGREGATORS_PER_COMMITTEE: 16
-# 2**0 (= 1)
-RANDOM_SUBNETS_PER_VALIDATOR: 1
 # 2**8 (= 256)
 EPOCHS_PER_RANDOM_SUBNET_SUBSCRIPTION: 256
 # 14 (estimate from Eth1 mainnet)

ethereum/spec/src/test/resources/tech/pegasys/teku/spec/config/mergeForkSpec.json

@@ -70,7 +70,6 @@
   "PROPORTIONAL_SLASHING_MULTIPLIER_MERGE": "3",
   "PROPOSER_REWARD_QUOTIENT": "8",
   "PROPOSER_SCORE_BOOST": "70",
-  "RANDOM_SUBNETS_PER_VALIDATOR": "1",
   "SAFE_SLOTS_TO_UPDATE_JUSTIFIED": "8",
   "SECONDS_PER_ETH1_BLOCK": "14",
   "SECONDS_PER_SLOT": "12",

networking/eth2/build.gradle

@@ -24,6 +24,7 @@ dependencies {
   implementation 'io.libp2p:jvm-libp2p-minimal'
   implementation 'org.apache.tuweni:tuweni-ssz'
   implementation 'org.xerial.snappy:snappy-java'
+  implementation 'tech.pegasys.discovery:discovery'
 
   testImplementation testFixtures(project(':infrastructure:metrics'))
   testImplementation testFixtures(project(':ethereum:spec'))

networking/eth2/src/main/java/tech/pegasys/teku/networking/eth2/gossip/subnets/ValidatorBasedStableSubnetSubscriber.java

@@ -16,20 +16,29 @@
 import static java.lang.Integer.max;
 import static java.lang.Integer.min;
 import static java.util.Collections.emptySet;
+import static tech.pegasys.teku.spec.logic.common.helpers.MathHelpers.uint64ToBytes;
 
 import it.unimi.dsi.fastutil.ints.IntOpenHashSet;
 import it.unimi.dsi.fastutil.ints.IntSet;
+import java.math.BigInteger;
 import java.util.Comparator;
-import java.util.HashSet;
 import java.util.Iterator;
+import java.util.List;
 import java.util.NavigableSet;
 import java.util.Optional;
 import java.util.Random;
 import java.util.Set;
 import java.util.TreeSet;
+import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
+import org.apache.tuweni.bytes.Bytes;
+import org.apache.tuweni.bytes.Bytes32;
+import org.apache.tuweni.units.bigints.UInt256;
+import org.bouncycastle.math.ec.ECPoint;
+import org.ethereum.beacon.discovery.util.Functions;
+import tech.pegasys.teku.infrastructure.crypto.Hash;
 import tech.pegasys.teku.infrastructure.unsigned.UInt64;
 import tech.pegasys.teku.spec.Spec;
 import tech.pegasys.teku.spec.config.SpecConfig;
@@ -49,18 +58,28 @@ public class ValidatorBasedStableSubnetSubscriber implements StableSubnetSubscri
   private final Spec spec;
   private final int minimumSubnetSubscriptions;
   private final int attestationSubnetCount;
+  private final int attestationSubnetPrefixBits;
+  private final int epochsPerSubnetSubscription;
+  private final int subnetsPerNode;
+
+  private final Optional<Bytes> discoveryNodeId;
 
   public ValidatorBasedStableSubnetSubscriber(
       final AttestationTopicSubscriber persistentSubnetSubscriber,
       final Random random,
       final Spec spec,
-      final int minimumSubnetSubscriptions) {
+      final int minimumSubnetSubscriptions,
+      final Optional<Bytes> discoveryNodeId) {
     this.persistentSubnetSubscriber = persistentSubnetSubscriber;
     this.random = random;
     this.spec = spec;
     this.attestationSubnetCount = spec.getNetworkingConfig().getAttestationSubnetCount();
+    this.attestationSubnetPrefixBits = spec.getNetworkingConfig().getAttestationSubnetPrefixBits();
+    this.epochsPerSubnetSubscription = spec.getNetworkingConfig().getEpochsPerSubnetSubscription();
+    this.subnetsPerNode = spec.getNetworkingConfig().getSubnetsPerNode();
     IntStream.range(0, attestationSubnetCount).forEach(availableSubnetIndices::add);
     this.minimumSubnetSubscriptions = min(minimumSubnetSubscriptions, attestationSubnetCount);
+    this.discoveryNodeId = discoveryNodeId;
   }
 
   @Override
@@ -95,9 +114,8 @@ public void onSlot(final UInt64 slot, final int validatorCount) {
   private Set<SubnetSubscription> adjustNumberOfSubscriptionsToNumberOfValidators(
       UInt64 currentSlot, int validatorCount) {
 
-    final int randomSubnetsPerValidator = ValidatorConstants.RANDOM_SUBNETS_PER_VALIDATOR;
     final int requiredSubnetSubscriptions =
-        min(attestationSubnetCount, randomSubnetsPerValidator * validatorCount);
+        min(attestationSubnetCount, subnetsPerNode * validatorCount);
     final int totalNumberOfSubscriptions =
         max(requiredSubnetSubscriptions, minimumSubnetSubscriptions);
 
@@ -108,7 +126,14 @@ private Set<SubnetSubscription> adjustNumberOfSubscriptionsToNumberOfValidators(
         "Updating number of persistent subnet subscriptions from {} to {}",
         subnetSubscriptions.size(),
         totalNumberOfSubscriptions);
-    final Set<SubnetSubscription> newSubnetSubscriptions = new HashSet<>();
+
+    final List<UInt64> subscribedSubnets =
+        computeSubscribedSubnets(extractNodeId(), spec.computeEpochAtSlot(currentSlot));
+
+    final Set<SubnetSubscription> newSubnetSubscriptions =
+        subscribedSubnets.stream()
+            .map(subnetId -> subscribeToSubnet(currentSlot, subnetId.intValue()))
+            .collect(Collectors.toSet());
 
     while (subnetSubscriptions.size() != totalNumberOfSubscriptions) {
       if (subnetSubscriptions.size() < totalNumberOfSubscriptions) {
@@ -120,8 +145,43 @@ private Set<SubnetSubscription> adjustNumberOfSubscriptionsToNumberOfValidators(
     return newSubnetSubscriptions;
   }
 
+  private UInt256 extractNodeId() {
+    final ECPoint ecPoint =
+        Functions.publicKeyToPoint(
+            discoveryNodeId.orElseThrow(
+                () -> new IllegalArgumentException("Unable to get discovery node id")));
+    final Bytes pubKeyUncompressed = Bytes.wrap(ecPoint.getEncoded(false)).slice(1);
+    BigInteger nodeId = new BigInteger(pubKeyUncompressed.toArray());
+    return UInt256.valueOf(nodeId);
+  }
+
+  private List<UInt64> computeSubscribedSubnets(final UInt256 nodeId, final UInt64 epoch) {
+    return IntStream.range(0, subnetsPerNode)
+        .mapToObj(index -> computeSubscribedSubnet(nodeId, epoch, index))
+        .collect(Collectors.toList());
+  }
+
+  private UInt64 computeSubscribedSubnet(
+      final UInt256 nodeId, final UInt64 epoch, final int index) {
+
+    final int nodeIdPrefix =
+        nodeId.shiftRight(ValidatorConstants.NODE_ID_BITS - attestationSubnetPrefixBits).intValue();
+
+    final UInt64 nodeOffset = UInt64.valueOf(nodeId.mod(epochsPerSubnetSubscription).toLong());
+
+    final Bytes32 permutationSeed =
+        Hash.sha256(uint64ToBytes(epoch.plus(nodeOffset).dividedBy(epochsPerSubnetSubscription)));
+
+    final int permutedPrefix =
+        spec.atEpoch(epoch)
+            .miscHelpers()
+            .computeShuffledIndex(nodeIdPrefix, 1 << attestationSubnetPrefixBits, permutationSeed);
+
+    return UInt64.valueOf(permutedPrefix + index % attestationSubnetCount);
+  }
+
   /**
-   * Subscribes to a new random subnetId, if any subnetID is available. Returns the new
+   * Subscribes to a new random subnetId, if any subnetId is available. Returns the new
    * SubnetSubscription object.
    *
    * @param currentSlot the current slot
@@ -138,6 +198,14 @@ private SubnetSubscription subscribeToNewRandomSubnet(UInt64 currentSlot) {
     return subnetSubscription;
   }
 
+  private SubnetSubscription subscribeToSubnet(UInt64 currentSlot, int subnetId) {
+    availableSubnetIndices.remove(subnetId);
+    SubnetSubscription subnetSubscription =
+        new SubnetSubscription(subnetId, getRandomUnsubscriptionSlot(currentSlot));
+    subnetSubscriptions.add(subnetSubscription);
+    return subnetSubscription;
+  }
+
   /** Unsubscribe from a random subnet */
   private void unsubscribeFromRandomSubnet() {
     SubnetSubscription subnetSubscription =

networking/eth2/src/test/java/tech/pegasys/teku/networking/eth2/gossip/subnets/StableSubnetSubscriberTest.java

@@ -29,6 +29,7 @@
 import org.junit.jupiter.api.Test;
 import org.mockito.ArgumentCaptor;
 import tech.pegasys.teku.infrastructure.unsigned.UInt64;
+import tech.pegasys.teku.networking.p2p.mock.MockNodeId;
 import tech.pegasys.teku.spec.Spec;
 import tech.pegasys.teku.spec.TestSpecFactory;
 import tech.pegasys.teku.spec.datastructures.validator.SubnetSubscription;
@@ -197,6 +198,6 @@ private void assertSubnetsAreDistinct(Set<SubnetSubscription> subnetSubscription
 
   private StableSubnetSubscriber createStableSubnetSubscriber() {
     return new ValidatorBasedStableSubnetSubscriber(
-        validatorApiChannel, new Random(13241234L), spec, 0);
+        validatorApiChannel, new Random(13241234L), spec, 0, new MockNodeId());
   }
 }

networking/eth2/src/test/java/tech/pegasys/teku/networking/eth2/gossip/subnets/ValidatorBasedStableSubnetSubscriberTest.java

@@ -24,6 +24,7 @@
 import org.junit.jupiter.api.Test;
 import tech.pegasys.teku.infrastructure.unsigned.UInt64;
 import tech.pegasys.teku.networking.eth2.Eth2P2PNetwork;
+import tech.pegasys.teku.networking.p2p.mock.MockNodeId;
 import tech.pegasys.teku.spec.Spec;
 import tech.pegasys.teku.spec.TestSpecFactory;
 
@@ -58,6 +59,7 @@ private ValidatorBasedStableSubnetSubscriber createSubscriber(
         new AttestationTopicSubscriber(spec, network),
         new Random(),
         spec,
-        minimumSubnetSubscriptions);
+        minimumSubnetSubscriptions,
+        new MockNodeId());
   }
 }

networking/p2p/src/main/java/tech/pegasys/teku/networking/p2p/discovery/DiscoveryNetwork.java

@@ -105,6 +105,11 @@ public Optional<String> getEnr() {
     return discoveryService.getEnr();
   }
 
+  @Override
+  public Optional<Bytes> getDiscoveryNodeId() {
+    return discoveryService.getNodeId();
+  }
+
   @Override
   public Optional<String> getDiscoveryAddress() {
     return discoveryService.getDiscoveryAddress();