Merge branch 'validator-enhancements' into testnet-client

validator_client/src/block_producer/beacon_node_block.rs

@@ -0,0 +1,31 @@
+use types::{BeaconBlock, Signature, Slot};
+#[derive(Debug, PartialEq, Clone)]
+pub enum BeaconNodeError {
+    RemoteFailure(String),
+    DecodeFailure,
+}
+
+#[derive(Debug, PartialEq, Clone)]
+pub enum PublishOutcome {
+    Valid,
+    InvalidBlock(String),
+    InvalidAttestation(String),
+}
+
+/// Defines the methods required to produce and publish blocks on a Beacon Node. Abstracts the
+/// actual beacon node.
+pub trait BeaconNodeBlock: Send + Sync {
+    /// Request that the node produces a block.
+    ///
+    /// Returns Ok(None) if the Beacon Node is unable to produce at the given slot.
+    fn produce_beacon_block(
+        &self,
+        slot: Slot,
+        randao_reveal: &Signature,
+    ) -> Result<Option<BeaconBlock>, BeaconNodeError>;
+
+    /// Request that the node publishes a block.
+    ///
+    /// Returns `true` if the publish was successful.
+    fn publish_beacon_block(&self, block: BeaconBlock) -> Result<PublishOutcome, BeaconNodeError>;
+}

validator_client/src/block_producer/grpc.rs

@@ -0,0 +1,83 @@
+use super::beacon_node_block::*;
+use protos::services::{
+    BeaconBlock as GrpcBeaconBlock, ProduceBeaconBlockRequest, PublishBeaconBlockRequest,
+};
+use protos::services_grpc::BeaconBlockServiceClient;
+use ssz::{decode, ssz_encode};
+use std::sync::Arc;
+use types::{BeaconBlock, Signature, Slot};
+
+//TODO: Remove this new type. Do not need to wrap
+/// A newtype designed to wrap the gRPC-generated service so the `BeaconNode` trait may be
+/// implemented upon it.
+pub struct BeaconBlockGrpcClient {
+    client: Arc<BeaconBlockServiceClient>,
+}
+
+impl BeaconBlockGrpcClient {
+    pub fn new(client: Arc<BeaconBlockServiceClient>) -> Self {
+        Self { client }
+    }
+}
+
+impl BeaconNodeBlock for BeaconBlockGrpcClient {
+    /// Request a Beacon Node (BN) to produce a new block at the supplied slot.
+    ///
+    /// Returns `None` if it is not possible to produce at the supplied slot. For example, if the
+    /// BN is unable to find a parent block.
+    fn produce_beacon_block(
+        &self,
+        slot: Slot,
+        randao_reveal: &Signature,
+    ) -> Result<Option<BeaconBlock>, BeaconNodeError> {
+        // request a beacon block from the node
+        let mut req = ProduceBeaconBlockRequest::new();
+        req.set_slot(slot.as_u64());
+        req.set_randao_reveal(ssz_encode(randao_reveal));
+
+        //TODO: Determine if we want an explicit timeout
+        let reply = self
+            .client
+            .produce_beacon_block(&req)
+            .map_err(|err| BeaconNodeError::RemoteFailure(format!("{:?}", err)))?;
+
+        // format the reply
+        if reply.has_block() {
+            let block = reply.get_block();
+            let ssz = block.get_ssz();
+
+            let block = decode::<BeaconBlock>(&ssz).map_err(|_| BeaconNodeError::DecodeFailure)?;
+
+            Ok(Some(block))
+        } else {
+            Ok(None)
+        }
+    }
+
+    /// Request a Beacon Node (BN) to publish a block.
+    ///
+    /// Generally, this will be called after a `produce_beacon_block` call with a block that has
+    /// been completed (signed) by the validator client.
+    fn publish_beacon_block(&self, block: BeaconBlock) -> Result<PublishOutcome, BeaconNodeError> {
+        let mut req = PublishBeaconBlockRequest::new();
+
+        let ssz = ssz_encode(&block);
+
+        let mut grpc_block = GrpcBeaconBlock::new();
+        grpc_block.set_ssz(ssz);
+
+        req.set_block(grpc_block);
+
+        let reply = self
+            .client
+            .publish_beacon_block(&req)
+            .map_err(|err| BeaconNodeError::RemoteFailure(format!("{:?}", err)))?;
+
+        if reply.get_success() {
+            Ok(PublishOutcome::Valid)
+        } else {
+            // TODO: distinguish between different errors
+            Ok(PublishOutcome::InvalidBlock("Publish failed".to_string()))
+        }
+    }
+}

validator_client/src/block_producer/mod.rs

@@ -0,0 +1,242 @@
+mod beacon_node_block;
+mod grpc;
+
+use self::beacon_node_block::BeaconNodeBlock;
+pub use self::beacon_node_block::{BeaconNodeError, PublishOutcome};
+pub use self::grpc::BeaconBlockGrpcClient;
+use crate::signer::Signer;
+use slog::{error, info, warn};
+use ssz::{SignedRoot, TreeHash};
+use std::sync::Arc;
+use types::{BeaconBlock, ChainSpec, Domain, Fork, Slot};
+
+#[derive(Debug, PartialEq)]
+pub enum Error {
+    BeaconNodeError(BeaconNodeError),
+}
+
+#[derive(Debug, PartialEq)]
+pub enum ValidatorEvent {
+    /// A new block was produced.
+    BlockProduced(Slot),
+    /// A new attestation was produced.
+    AttestationProduced(Slot),
+    /// A block was not produced as it would have been slashable.
+    SlashableBlockNotProduced(Slot),
+    /// An attestation was not produced as it would have been slashable.
+    SlashableAttestationNotProduced(Slot),
+    /// The Beacon Node was unable to produce a block at that slot.
+    BeaconNodeUnableToProduceBlock(Slot),
+    /// The signer failed to sign the message.
+    SignerRejection(Slot),
+    /// Publishing an attestation failed.
+    PublishAttestationFailed,
+    /// Beacon node rejected the attestation.
+    InvalidAttestation,
+}
+
+/// This struct contains the logic for requesting and signing beacon blocks for a validator. The
+/// validator can abstractly sign via the Signer trait object.
+pub struct BlockProducer<'a, B: BeaconNodeBlock, S: Signer> {
+    /// The current fork.
+    pub fork: Fork,
+    /// The current slot to produce a block for.
+    pub slot: Slot,
+    /// The current epoch.
+    pub spec: Arc<ChainSpec>,
+    /// The beacon node to connect to.
+    pub beacon_node: Arc<B>,
+    /// The signer to sign the block.
+    pub signer: &'a S,
+}
+
+impl<'a, B: BeaconNodeBlock, S: Signer> BlockProducer<'a, B, S> {
+    /// Handle outputs and results from block production.
+    pub fn handle_produce_block(&mut self, log: slog::Logger) {
+        match self.produce_block() {
+            Ok(ValidatorEvent::BlockProduced(_slot)) => {
+                info!(log, "Block produced"; "Validator" => format!("{}", self.signer))
+            }
+            Err(e) => error!(log, "Block production error"; "Error" => format!("{:?}", e)),
+            Ok(ValidatorEvent::SignerRejection(_slot)) => {
+                error!(log, "Block production error"; "Error" => "Signer Could not sign the block".to_string())
+            }
+            Ok(ValidatorEvent::SlashableBlockNotProduced(_slot)) => {
+                error!(log, "Block production error"; "Error" => "Rejected the block as it could have been slashed".to_string())
+            }
+            Ok(ValidatorEvent::BeaconNodeUnableToProduceBlock(_slot)) => {
+                error!(log, "Block production error"; "Error" => "Beacon node was unable to produce a block".to_string())
+            }
+            Ok(v) => {
+                warn!(log, "Unknown result for block production"; "Error" => format!("{:?}",v))
+            }
+        }
+    }
+
+    /// Produce a block at some slot.
+    ///
+    /// Assumes that a block is required at this slot (does not check the duties).
+    ///
+    /// Ensures the message is not slashable.
+    ///
+    /// !!! UNSAFE !!!
+    ///
+    /// The slash-protection code is not yet implemented. There is zero protection against
+    /// slashing.
+    pub fn produce_block(&mut self) -> Result<ValidatorEvent, Error> {
+        let epoch = self.slot.epoch(self.spec.slots_per_epoch);
+
+        let message = epoch.hash_tree_root();
+        let randao_reveal = match self.signer.sign_message(
+            &message,
+            self.spec.get_domain(epoch, Domain::Randao, &self.fork),
+        ) {
+            None => return Ok(ValidatorEvent::SignerRejection(self.slot)),
+            Some(signature) => signature,
+        };
+
+        if let Some(block) = self
+            .beacon_node
+            .produce_beacon_block(self.slot, &randao_reveal)?
+        {
+            if self.safe_to_produce(&block) {
+                let domain = self.spec.get_domain(epoch, Domain::BeaconBlock, &self.fork);
+                if let Some(block) = self.sign_block(block, domain) {
+                    self.beacon_node.publish_beacon_block(block)?;
+                    Ok(ValidatorEvent::BlockProduced(self.slot))
+                } else {
+                    Ok(ValidatorEvent::SignerRejection(self.slot))
+                }
+            } else {
+                Ok(ValidatorEvent::SlashableBlockNotProduced(self.slot))
+            }
+        } else {
+            Ok(ValidatorEvent::BeaconNodeUnableToProduceBlock(self.slot))
+        }
+    }
+
+    /// Consumes a block, returning that block signed by the validators private key.
+    ///
+    /// Important: this function will not check to ensure the block is not slashable. This must be
+    /// done upstream.
+    fn sign_block(&mut self, mut block: BeaconBlock, domain: u64) -> Option<BeaconBlock> {
+        self.store_produce(&block);
+
+        match self.signer.sign_message(&block.signed_root()[..], domain) {
+            None => None,
+            Some(signature) => {
+                block.signature = signature;
+                Some(block)
+            }
+        }
+    }
+
+    /// Returns `true` if signing a block is safe (non-slashable).
+    ///
+    /// !!! UNSAFE !!!
+    ///
+    /// Important: this function is presently stubbed-out. It provides ZERO SAFETY.
+    fn safe_to_produce(&self, _block: &BeaconBlock) -> bool {
+        // TODO: ensure the producer doesn't produce slashable blocks.
+        // https://github.com/sigp/lighthouse/issues/160
+        true
+    }
+
+    /// Record that a block was produced so that slashable votes may not be made in the future.
+    ///
+    /// !!! UNSAFE !!!
+    ///
+    /// Important: this function is presently stubbed-out. It provides ZERO SAFETY.
+    fn store_produce(&mut self, _block: &BeaconBlock) {
+        // TODO: record this block production to prevent future slashings.
+        // https://github.com/sigp/lighthouse/issues/160
+    }
+}
+
+impl From<BeaconNodeError> for Error {
+    fn from(e: BeaconNodeError) -> Error {
+        Error::BeaconNodeError(e)
+    }
+}
+
+/* Old tests - Re-work for new logic
+#[cfg(test)]
+mod tests {
+    use super::test_utils::{EpochMap, LocalSigner, SimulatedBeaconNode};
+    use super::*;
+    use slot_clock::TestingSlotClock;
+    use types::{
+        test_utils::{SeedableRng, TestRandom, XorShiftRng},
+        Keypair,
+    };
+
+    // TODO: implement more thorough testing.
+    // https://github.com/sigp/lighthouse/issues/160
+    //
+    // These tests should serve as a good example for future tests.
+
+    #[test]
+    pub fn polling() {
+        let mut rng = XorShiftRng::from_seed([42; 16]);
+
+        let spec = Arc::new(ChainSpec::foundation());
+        let slot_clock = Arc::new(TestingSlotClock::new(0));
+        let beacon_node = Arc::new(SimulatedBeaconNode::default());
+        let signer = Arc::new(LocalSigner::new(Keypair::random()));
+
+        let mut epoch_map = EpochMap::new(spec.slots_per_epoch);
+        let produce_slot = Slot::new(100);
+        let produce_epoch = produce_slot.epoch(spec.slots_per_epoch);
+        epoch_map.map.insert(produce_epoch, produce_slot);
+        let epoch_map = Arc::new(epoch_map);
+
+        let mut block_proposer = BlockProducer::new(
+            spec.clone(),
+            epoch_map.clone(),
+            slot_clock.clone(),
+            beacon_node.clone(),
+            signer.clone(),
+        );
+
+        // Configure responses from the BeaconNode.
+        beacon_node.set_next_produce_result(Ok(Some(BeaconBlock::random_for_test(&mut rng))));
+        beacon_node.set_next_publish_result(Ok(PublishOutcome::ValidBlock));
+
+        // One slot before production slot...
+        slot_clock.set_slot(produce_slot.as_u64() - 1);
+        assert_eq!(
+            block_proposer.poll(),
+            Ok(PollOutcome::BlockProductionNotRequired(produce_slot - 1))
+        );
+
+        // On the produce slot...
+        slot_clock.set_slot(produce_slot.as_u64());
+        assert_eq!(
+            block_proposer.poll(),
+            Ok(PollOutcome::BlockProduced(produce_slot.into()))
+        );
+
+        // Trying the same produce slot again...
+        slot_clock.set_slot(produce_slot.as_u64());
+        assert_eq!(
+            block_proposer.poll(),
+            Ok(PollOutcome::SlotAlreadyProcessed(produce_slot))
+        );
+
+        // One slot after the produce slot...
+        slot_clock.set_slot(produce_slot.as_u64() + 1);
+        assert_eq!(
+            block_proposer.poll(),
+            Ok(PollOutcome::BlockProductionNotRequired(produce_slot + 1))
+        );
+
+        // In an epoch without known duties...
+        let slot = (produce_epoch.as_u64() + 1) * spec.slots_per_epoch;
+        slot_clock.set_slot(slot);
+        assert_eq!(
+            block_proposer.poll(),
+            Ok(PollOutcome::ProducerDutiesUnknown(Slot::new(slot)))
+        );
+    }
+}
+*/