simplify duplicate validator detection UI

Author: tersec

beacon_chain/conf.nim

@@ -250,15 +250,11 @@ type
         desc: "Write SSZ dumps of blocks, attestations and states to data dir"
         name: "dump" }: bool
 
-      dupProtectionEpochs* {.
-        defaultValue: 0
-        desc: "Number of epochs of gossip to which to listen before broadcasting"
-        name: "dup-protection-epochs" }: uint64
-
-      dupProtectionQuit* {.
-        defaultValue: true
-        desc: "Whether to quit, rather than just disabling validators, if duplicate validators are detected"
-        name: "dup-protection-quit" }: bool
+      duplicateValidator* {.
+        defaultValue: "warn"
+        desc: "What to do when another validator is detected to be running the same validator keys (default `warn`, will become `stop` in the future)"
+        name: "duplicate-validator"
+      }: string
 
     of createTestnet:
       testnetDepositsFile* {.

beacon_chain/eth2_processor.nim

@@ -305,10 +305,12 @@ proc checkForPotentialSelfSlashing(
 
     GUARD_EPOCHS = ATTESTATION_PROPAGATION_SLOT_RANGE div SLOTS_PER_EPOCH
 
+  # If duplicateValidator not dontcheck or stop, it's the default "warn". The
+  # dontcheck option's a deliberately undocumented escape hatch for the local
+  # testnets and similar development and testing use cases.
   let epoch = wallSlot.epoch
-  # Can skip this whole conditional by setting relevant config value to 0
-  if epoch < self.dupProtection.broadcastStartEpoch and
-      self.dupProtection.probeEpoch > 0 and
+  if  self.config.duplicateValidator != "dontcheck" and
+      epoch < self.dupProtection.broadcastStartEpoch and
       epoch >= self.dupProtection.probeEpoch and
       epoch <= self.dupProtection.probeEpoch + GUARD_EPOCHS:
     let tgtBlck = self.chainDag.getRef(attestationData.target.root)
@@ -324,7 +326,7 @@ proc checkForPotentialSelfSlashing(
           validatorIndex,
           validatorPubkey
         beacon_duplicate_validator_protection_activated.inc()
-        if self.config.dupProtectionQuit:
+        if self.config.duplicateValidator == "stop":
           quit QuitFailure
 
 proc attestationValidator*(

beacon_chain/nimbus_beacon_node.nim

@@ -516,8 +516,10 @@ proc setupSelfSlashingProtection(node: BeaconNode, slot: Slot) =
   #
   # This approach catches both startup and network outage conditions.
 
+  const duplicateValidatorEpochs = 2
+
   node.processor.dupProtection.broadcastStartEpoch =
-    slot.epoch + node.config.dupProtectionEpochs
+    slot.epoch + duplicateValidatorEpochs
   # randomize() already called; also, never probe on first epoch in guard
   # period, so that existing, running validators can be picked up. Whilst
   # this reduces entropy for overlapping-start cases, and increases their
@@ -526,14 +528,12 @@ proc setupSelfSlashingProtection(node: BeaconNode, slot: Slot) =
   # duplicate pair overlaps exactly, only the running/starting case. Even
   # 2 epochs is dangerous because it'll guarantee colliding probes in the
   # overlapping case.
-  if node.config.dupProtectionEpochs > 1:
-    # So dPE == 2 -> epoch + 1, always; dPE == 3 -> epoch + (1 or 2), etc.
-    node.processor.dupProtection.probeEpoch =
-      slot.epoch + 1 + rand(node.config.dupProtectionEpochs.int - 2).uint64
-    doAssert node.processor.dupProtection.probeEpoch <
-      node.processor.dupProtection.broadcastStartEpoch
-  else:
-    node.processor.dupProtection.probeEpoch = 0.Epoch # don't probe
+
+  # So dPE == 2 -> epoch + 1, always; dPE == 3 -> epoch + (1 or 2), etc.
+  node.processor.dupProtection.probeEpoch =
+    slot.epoch + 1 + rand(duplicateValidatorEpochs.int - 2).uint64
+  doAssert node.processor.dupProtection.probeEpoch <
+    node.processor.dupProtection.broadcastStartEpoch
 
   debug "Setting up self-slashing protection",
     epoch = slot.epoch,

scripts/launch_local_testnet.sh

@@ -384,7 +384,7 @@ for NUM_NODE in $(seq 0 $(( NUM_NODES - 1 ))); do
     --metrics \
     --metrics-address="127.0.0.1" \
     --metrics-port="$(( BASE_METRICS_PORT + NUM_NODE ))" \
-    --dup-protection-epochs=0 \
+    --duplicate-validator=dontcheck \
     ${EXTRA_ARGS} \
     > "${DATA_DIR}/log${NUM_NODE}.txt" 2>&1 &
 

tests/simulation/run_node.sh

@@ -105,6 +105,6 @@ $BEACON_NODE_BIN \
   --metrics \
   --metrics-address="127.0.0.1" \
   --metrics-port="$(( $BASE_METRICS_PORT + $NODE_ID ))" \
-  --dup-protection-epochs=0 \
+  --duplicate-validator=dontcheck \
   ${ADDITIONAL_BEACON_NODE_ARGS} \
   "$@"