Fixed merge conflicts with master, with new release testing options.

.travis.yml

@@ -8,10 +8,12 @@ before_install:
   - sudo chown -R $USER /usr/local/include/google
 script:
   - cargo build --verbose --all
+  - cargo build --verbose --release --all
+  - cargo test --verbose --all
+  - cargo test --verbose --release --all
   - cargo fmt --all -- --check
   # No clippy until later...
   #- cargo clippy
-  - cargo test --verbose --all
 rust:
   - stable
   - beta

Cargo.toml

@@ -29,4 +29,5 @@ members = [
 	"beacon_node/beacon_chain/test_harness",
 	"protos",
 	"validator_client",
+	"account_manager",
 ]

Jenkinsfile

@@ -1,16 +1,17 @@
 pipeline {
-    agent {
+	agent {
 		dockerfile {
 			filename 'Dockerfile'
 			args '-v cargo-cache:/cargocache:rw'
 		}
 	}
-    stages {
-        stage('Build') {
-            steps {
-                sh 'cargo build'
-            }
-        }
+	stages {
+		stage('Build') {
+			steps {
+				sh 'cargo build --verbose --all'
+				sh 'cargo build --verbose --all --release'
+			}
+		}
         stage('Check') {
             steps {
                 sh 'cargo fmt --all -- --check'
@@ -18,10 +19,11 @@ pipeline {
                 //sh 'cargo clippy'
             }
         }
-        stage('Test') {
+		stage('Test') {
 			steps {
-				sh 'cargo test --all'
+				sh 'cargo test --verbose --all'
+				sh 'cargo test --verbose --all --release'
 			}
 		}
-    }
+	}
 }

account_manager/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "account_manager"
+version = "0.0.1"
+authors = ["Luke Anderson <luke@sigmaprime.io>"]
+edition = "2018"
+
+[dependencies]
+bls = { path = "../eth2/utils/bls" }
+clap = "2.32.0"
+slog = "^2.2.3"
+slog-term = "^2.4.0"
+slog-async = "^2.3.0"
+validator_client = { path = "../validator_client" }

account_manager/README.md

@@ -0,0 +1,24 @@
+# Lighthouse Accounts Manager
+
+The accounts manager (AM) is a stand-alone binary which allows
+users to generate and manage the cryptographic keys necessary to
+interact with Ethereum Serenity.
+
+## Roles
+
+The AM is responsible for the following tasks:
+- Generation of cryptographic key pairs
+  - Must acquire sufficient entropy to ensure keys are generated securely (TBD)
+- Secure storage of private keys
+  - Keys must be encrypted while at rest on the disk (TBD)
+  - The format is compatible with the validator client
+- Produces messages and transactions necessary to initiate
+staking on Ethereum 1.x (TPD)
+
+
+## Implementation
+
+The AM is not a service, and does not run continuously, nor does it
+interact with any running services.
+It is intended to be executed separately from other Lighthouse binaries
+and produce files which can be consumed by them.

account_manager/src/main.rs

@@ -0,0 +1,58 @@
+use bls::Keypair;
+use clap::{App, Arg, SubCommand};
+use slog::{debug, info, o, Drain};
+use std::path::PathBuf;
+use validator_client::Config as ValidatorClientConfig;
+
+fn main() {
+    // Logging
+    let decorator = slog_term::TermDecorator::new().build();
+    let drain = slog_term::CompactFormat::new(decorator).build().fuse();
+    let drain = slog_async::Async::new(drain).build().fuse();
+    let log = slog::Logger::root(drain, o!());
+
+    // CLI
+    let matches = App::new("Lighthouse Accounts Manager")
+        .version("0.0.1")
+        .author("Sigma Prime <contact@sigmaprime.io>")
+        .about("Eth 2.0 Accounts Manager")
+        .arg(
+            Arg::with_name("datadir")
+                .long("datadir")
+                .value_name("DIR")
+                .help("Data directory for keys and databases.")
+                .takes_value(true),
+        )
+        .subcommand(
+            SubCommand::with_name("generate")
+                .about("Generates a new validator private key")
+                .version("0.0.1")
+                .author("Sigma Prime <contact@sigmaprime.io>"),
+        )
+        .get_matches();
+
+    let config = ValidatorClientConfig::parse_args(&matches, &log)
+        .expect("Unable to build a configuration for the account manager.");
+
+    // Log configuration
+    info!(log, "";
+          "data_dir" => &config.data_dir.to_str());
+
+    match matches.subcommand() {
+        ("generate", Some(_gen_m)) => {
+            let keypair = Keypair::random();
+            let key_path: PathBuf = config
+                .save_key(&keypair)
+                .expect("Unable to save newly generated private key.");
+            debug!(
+                log,
+                "Keypair generated {:?}, saved to: {:?}",
+                keypair.identifier(),
+                key_path.to_string_lossy()
+            );
+        }
+        _ => panic!(
+            "The account manager must be run with a subcommand. See help for more information."
+        ),
+    }
+}

beacon_node/beacon_chain/src/beacon_chain.rs

@@ -26,7 +26,10 @@ pub enum ValidBlock {
 #[derive(Debug, PartialEq)]
 pub enum InvalidBlock {
     /// The block slot is greater than the present slot.
-    FutureSlot,
+    FutureSlot {
+        present_slot: Slot,
+        block_slot: Slot,
+    },
     /// The block state_root does not match the generated state.
     StateRootMismatch,
     /// The blocks parent_root is unknown.
@@ -46,6 +49,35 @@ pub enum BlockProcessingOutcome {
     InvalidBlock(InvalidBlock),
 }
 
+impl BlockProcessingOutcome {
+    /// Returns `true` if the block was objectively invalid and we should disregard the peer who
+    /// sent it.
+    pub fn is_invalid(&self) -> bool {
+        match self {
+            BlockProcessingOutcome::ValidBlock(_) => false,
+            BlockProcessingOutcome::InvalidBlock(r) => match r {
+                InvalidBlock::FutureSlot { .. } => true,
+                InvalidBlock::StateRootMismatch => true,
+                InvalidBlock::ParentUnknown => false,
+                InvalidBlock::SlotProcessingError(_) => false,
+                InvalidBlock::PerBlockProcessingError(e) => match e {
+                    BlockProcessingError::Invalid(_) => true,
+                    BlockProcessingError::BeaconStateError(_) => false,
+                },
+            },
+        }
+    }
+
+    /// Returns `true` if the block was successfully processed and can be removed from any import
+    /// queues or temporary storage.
+    pub fn sucessfully_processed(&self) -> bool {
+        match self {
+            BlockProcessingOutcome::ValidBlock(_) => true,
+            _ => false,
+        }
+    }
+}
+
 pub struct BeaconChain<T: ClientDB + Sized, U: SlotClock, F: ForkChoice> {
     pub block_store: Arc<BeaconBlockStore<T>>,
     pub state_store: Arc<BeaconStateStore<T>>,
@@ -122,6 +154,126 @@ where
         })
     }
 
+    /// Returns the beacon block body for each beacon block root in `roots`.
+    ///
+    /// Fails if any root in `roots` does not have a corresponding block.
+    pub fn get_block_bodies(&self, roots: &[Hash256]) -> Result<Vec<BeaconBlockBody>, Error> {
+        let bodies: Result<Vec<BeaconBlockBody>, _> = roots
+            .iter()
+            .map(|root| match self.get_block(root)? {
+                Some(block) => Ok(block.body),
+                None => Err(Error::DBInconsistent("Missing block".into())),
+            })
+            .collect();
+
+        Ok(bodies?)
+    }
+
+    /// Returns the beacon block header for each beacon block root in `roots`.
+    ///
+    /// Fails if any root in `roots` does not have a corresponding block.
+    pub fn get_block_headers(&self, roots: &[Hash256]) -> Result<Vec<BeaconBlockHeader>, Error> {
+        let headers: Result<Vec<BeaconBlockHeader>, _> = roots
+            .iter()
+            .map(|root| match self.get_block(root)? {
+                Some(block) => Ok(block.block_header()),
+                None => Err(Error::DBInconsistent("Missing block".into())),
+            })
+            .collect();
+
+        Ok(headers?)
+    }
+
+    /// Returns `count `beacon block roots, starting from `start_slot` with an
+    /// interval of `skip` slots between each root.
+    ///
+    /// ## Errors:
+    ///
+    /// - `SlotOutOfBounds`: Unable to return the full specified range.
+    /// - `SlotOutOfBounds`: Unable to load a state from the DB.
+    /// - `SlotOutOfBounds`: Start slot is higher than the first slot.
+    /// - Other: BeaconState` is inconsistent.
+    pub fn get_block_roots(
+        &self,
+        earliest_slot: Slot,
+        count: usize,
+        skip: usize,
+    ) -> Result<Vec<Hash256>, Error> {
+        let spec = &self.spec;
+        let step_by = Slot::from(skip + 1);
+
+        let mut roots: Vec<Hash256> = vec![];
+
+        // The state for reading block roots. Will be updated with an older state if slots go too
+        // far back in history.
+        let mut state = self.state.read().clone();
+
+        // The final slot in this series, will be reduced by `skip` each loop iteration.
+        let mut slot = earliest_slot + Slot::from(count * (skip + 1)) - 1;
+
+        // If the highest slot requested is that of the current state insert the root of the
+        // head block, unless the head block's slot is not matching.
+        if slot == state.slot && self.head().beacon_block.slot == slot {
+            roots.push(self.head().beacon_block_root);
+
+            slot -= step_by;
+        } else if slot >= state.slot {
+            return Err(BeaconStateError::SlotOutOfBounds.into());
+        }
+
+        loop {
+            // If the slot is within the range of the current state's block roots, append the root
+            // to the output vec.
+            //
+            // If we get `SlotOutOfBounds` error, load the oldest available historic
+            // state from the DB.
+            match state.get_block_root(slot, spec) {
+                Ok(root) => {
+                    if slot < earliest_slot {
+                        break;
+                    } else {
+                        roots.push(*root);
+                        slot -= step_by;
+                    }
+                }
+                Err(BeaconStateError::SlotOutOfBounds) => {
+                    // Read the earliest historic state in the current slot.
+                    let earliest_historic_slot =
+                        state.slot - Slot::from(spec.slots_per_historical_root);
+                    // Load the earlier state from disk.
+                    let new_state_root = state.get_state_root(earliest_historic_slot, spec)?;
+
+                    // Break if the DB is unable to load the state.
+                    state = match self.state_store.get_deserialized(&new_state_root) {
+                        Ok(Some(state)) => state,
+                        _ => break,
+                    }
+                }
+                Err(e) => return Err(e.into()),
+            };
+        }
+
+        // Return the results if they pass a sanity check.
+        if (slot <= earliest_slot) && (roots.len() == count) {
+            // Reverse the ordering of the roots. We extracted them in reverse order to make it
+            // simpler to lookup historic states.
+            //
+            // This is a potential optimisation target.
+            Ok(roots.iter().rev().cloned().collect())
+        } else {
+            Err(BeaconStateError::SlotOutOfBounds.into())
+        }
+    }
+
+    /// Returns the block at the given root, if any.
+    ///
+    /// ## Errors
+    ///
+    /// May return a database error.
+    pub fn get_block(&self, block_root: &Hash256) -> Result<Option<BeaconBlock>, Error> {
+        Ok(self.block_store.get_deserialized(block_root)?)
+    }
+
     /// Update the canonical head to some new values.
     pub fn update_canonical_head(
         &self,
@@ -153,6 +305,49 @@ where
         self.canonical_head.read()
     }
 
+    /// Updates the canonical `BeaconState` with the supplied state.
+    ///
+    /// Advances the chain forward to the present slot. This method is better than just setting
+    /// state and calling `catchup_state` as it will not result in an old state being installed and
+    /// then having it iteratively updated -- in such a case it's possible for another thread to
+    /// find the state at an old slot.
+    pub fn update_state(&self, mut state: BeaconState) -> Result<(), Error> {
+        let latest_block_header = self.head().beacon_block.block_header();
+
+        let present_slot = match self.slot_clock.present_slot() {
+            Ok(Some(slot)) => slot,
+            _ => return Err(Error::UnableToReadSlot),
+        };
+
+        // If required, transition the new state to the present slot.
+        for _ in state.slot.as_u64()..present_slot.as_u64() {
+            per_slot_processing(&mut state, &latest_block_header, &self.spec)?;
+        }
+
+        *self.state.write() = state;
+
+        Ok(())
+    }
+
+    /// Ensures the current canonical `BeaconState` has been transitioned to match the `slot_clock`.
+    pub fn catchup_state(&self) -> Result<(), Error> {
+        let latest_block_header = self.head().beacon_block.block_header();
+
+        let present_slot = match self.slot_clock.present_slot() {
+            Ok(Some(slot)) => slot,
+            _ => return Err(Error::UnableToReadSlot),
+        };
+
+        let mut state = self.state.write();
+
+        // If required, transition the new state to the present slot.
+        for _ in state.slot.as_u64()..present_slot.as_u64() {
+            per_slot_processing(&mut *state, &latest_block_header, &self.spec)?;
+        }
+
+        Ok(())
+    }
+
     /// Update the justified head to some new values.
     pub fn update_finalized_head(
         &self,
@@ -176,28 +371,6 @@ where
         self.finalized_head.read()
     }
 
-    /// Advance the `self.state` `BeaconState` to the supplied slot.
-    ///
-    /// This will perform per_slot and per_epoch processing as required.
-    ///
-    /// The `previous_block_root` will be set to the root of the current head block (as determined
-    /// by the fork-choice rule).
-    ///
-    /// It is important to note that this is _not_ the state corresponding to the canonical head
-    /// block, instead it is that state which may or may not have had additional per slot/epoch
-    /// processing applied to it.
-    pub fn advance_state(&self, slot: Slot) -> Result<(), SlotProcessingError> {
-        let state_slot = self.state.read().slot;
-
-        let latest_block_header = self.head().beacon_block.block_header();
-
-        for _ in state_slot.as_u64()..slot.as_u64() {
-            per_slot_processing(&mut *self.state.write(), &latest_block_header, &self.spec)?;
-        }
-
-        Ok(())
-    }
-
     /// Returns the validator index (if any) for the given public key.
     ///
     /// Information is retrieved from the present `beacon_state.validator_registry`.
@@ -246,7 +419,10 @@ where
     /// Information is read from the present `beacon_state` shuffling, so only information from the
     /// present and prior epoch is available.
     pub fn block_proposer(&self, slot: Slot) -> Result<usize, BeaconStateError> {
-        trace!("BeaconChain::block_proposer: slot: {}", slot);
+        self.state
+            .write()
+            .build_epoch_cache(RelativeEpoch::Current, &self.spec)?;
+
         let index = self.state.read().get_beacon_proposer_index(
             slot,
             RelativeEpoch::Current,
@@ -555,6 +731,11 @@ where
         }
     }
 
+    /// Returns `true` if the given block root has not been processed.
+    pub fn is_new_block_root(&self, beacon_block_root: &Hash256) -> Result<bool, Error> {
+        Ok(!self.block_store.exists(beacon_block_root)?)
+    }
+
     /// Accept some block and attempt to add it to block DAG.
     ///
     /// Will accept blocks from prior slots, however it will reject any block from a future slot.
@@ -567,7 +748,10 @@ where
 
         if block.slot > present_slot {
             return Ok(BlockProcessingOutcome::InvalidBlock(
-                InvalidBlock::FutureSlot,
+                InvalidBlock::FutureSlot {
+                    present_slot,
+                    block_slot: block.slot,
+                },
             ));
         }
 
@@ -594,10 +778,10 @@ where
         // TODO: check the block proposer signature BEFORE doing a state transition. This will
         // significantly lower exposure surface to DoS attacks.
 
-        // Transition the parent state to the present slot.
+        // Transition the parent state to the block slot.
         let mut state = parent_state;
         let previous_block_header = parent_block.block_header();
-        for _ in state.slot.as_u64()..present_slot.as_u64() {
+        for _ in state.slot.as_u64()..block.slot.as_u64() {
             if let Err(e) = per_slot_processing(&mut state, &previous_block_header, &self.spec) {
                 return Ok(BlockProcessingOutcome::InvalidBlock(
                     InvalidBlock::SlotProcessingError(e),
@@ -643,8 +827,9 @@ where
         // run instead.
         if self.head().beacon_block_root == parent_block_root {
             self.update_canonical_head(block.clone(), block_root, state.clone(), state_root);
-            // Update the local state variable.
-            *self.state.write() = state;
+
+            // Update the canonical `BeaconState`.
+            self.update_state(state)?;
         }
 
         Ok(BlockProcessingOutcome::ValidBlock(ValidBlock::Processed))
@@ -662,6 +847,8 @@ where
 
         let mut state = self.state.read().clone();
 
+        state.build_epoch_cache(RelativeEpoch::Current, &self.spec)?;
+
         trace!("Finding attestations for new block...");
 
         let attestations = self
@@ -732,7 +919,10 @@ where
                 .ok_or_else(|| Error::MissingBeaconState(block.state_root))?;
             let state_root = state.canonical_root();
 
-            self.update_canonical_head(block, block_root, state, state_root);
+            self.update_canonical_head(block, block_root, state.clone(), state_root);
+
+            // Update the canonical `BeaconState`.
+            self.update_state(state)?;
         }
 
         Ok(())

beacon_node/beacon_chain/src/checkpoint.rs

@@ -3,7 +3,7 @@ use types::{BeaconBlock, BeaconState, Hash256};
 
 /// Represents some block and it's associated state. Generally, this will be used for tracking the
 /// head, justified head and finalized head.
-#[derive(Clone, Serialize)]
+#[derive(Clone, Serialize, PartialEq, Debug)]
 pub struct CheckPoint {
     pub beacon_block: BeaconBlock,
     pub beacon_block_root: Hash256,

beacon_node/beacon_chain/src/errors.rs

@@ -1,5 +1,6 @@
 use fork_choice::ForkChoiceError;
 use state_processing::BlockProcessingError;
+use state_processing::SlotProcessingError;
 use types::*;
 
 macro_rules! easy_from_to {
@@ -16,18 +17,24 @@ macro_rules! easy_from_to {
 pub enum BeaconChainError {
     InsufficientValidators,
     BadRecentBlockRoots,
+    UnableToReadSlot,
     BeaconStateError(BeaconStateError),
     DBInconsistent(String),
     DBError(String),
     ForkChoiceError(ForkChoiceError),
     MissingBeaconBlock(Hash256),
     MissingBeaconState(Hash256),
+    SlotProcessingError(SlotProcessingError),
 }
 
+easy_from_to!(SlotProcessingError, BeaconChainError);
+
 #[derive(Debug, PartialEq)]
 pub enum BlockProductionError {
     UnableToGetBlockRootFromState,
     BlockProcessingError(BlockProcessingError),
+    BeaconStateError(BeaconStateError),
 }
 
 easy_from_to!(BlockProcessingError, BlockProductionError);
+easy_from_to!(BeaconStateError, BlockProductionError);

beacon_node/beacon_chain/src/lib.rs

@@ -3,10 +3,12 @@ mod beacon_chain;
 mod checkpoint;
 mod errors;
 pub mod initialise;
+pub mod test_utils;
 
 pub use self::beacon_chain::{BeaconChain, BlockProcessingOutcome, InvalidBlock, ValidBlock};
 pub use self::checkpoint::CheckPoint;
 pub use self::errors::BeaconChainError;
+pub use attestation_aggregator::Outcome as AggregationOutcome;
 pub use db;
 pub use fork_choice;
 pub use parking_lot;

beacon_node/beacon_chain/src/test_utils/mod.rs

@@ -0,0 +1,3 @@
+mod testing_beacon_chain_builder;
+
+pub use testing_beacon_chain_builder::TestingBeaconChainBuilder;

beacon_node/beacon_chain/src/test_utils/testing_beacon_chain_builder.rs

@@ -0,0 +1,50 @@
+pub use crate::{BeaconChain, BeaconChainError, CheckPoint};
+use db::{
+    stores::{BeaconBlockStore, BeaconStateStore},
+    MemoryDB,
+};
+use fork_choice::BitwiseLMDGhost;
+use slot_clock::TestingSlotClock;
+use ssz::TreeHash;
+use std::sync::Arc;
+use types::test_utils::TestingBeaconStateBuilder;
+use types::*;
+
+type TestingBeaconChain = BeaconChain<MemoryDB, TestingSlotClock, BitwiseLMDGhost<MemoryDB>>;
+
+pub struct TestingBeaconChainBuilder {
+    state_builder: TestingBeaconStateBuilder,
+}
+
+impl TestingBeaconChainBuilder {
+    pub fn build(self, spec: &ChainSpec) -> TestingBeaconChain {
+        let db = Arc::new(MemoryDB::open());
+        let block_store = Arc::new(BeaconBlockStore::new(db.clone()));
+        let state_store = Arc::new(BeaconStateStore::new(db.clone()));
+        let slot_clock = TestingSlotClock::new(spec.genesis_slot.as_u64());
+        let fork_choice = BitwiseLMDGhost::new(block_store.clone(), state_store.clone());
+
+        let (genesis_state, _keypairs) = self.state_builder.build();
+
+        let mut genesis_block = BeaconBlock::empty(&spec);
+        genesis_block.state_root = Hash256::from_slice(&genesis_state.hash_tree_root());
+
+        // Create the Beacon Chain
+        BeaconChain::from_genesis(
+            state_store.clone(),
+            block_store.clone(),
+            slot_clock,
+            genesis_state,
+            genesis_block,
+            spec.clone(),
+            fork_choice,
+        )
+        .unwrap()
+    }
+}
+
+impl From<TestingBeaconStateBuilder> for TestingBeaconChainBuilder {
+    fn from(state_builder: TestingBeaconStateBuilder) -> TestingBeaconChainBuilder {
+        TestingBeaconChainBuilder { state_builder }
+    }
+}

beacon_node/beacon_chain/test_harness/src/beacon_chain_harness.rs

@@ -15,6 +15,8 @@ use std::iter::FromIterator;
 use std::sync::Arc;
 use types::{test_utils::TestingBeaconStateBuilder, *};
 
+type TestingBeaconChain = BeaconChain<MemoryDB, TestingSlotClock, BitwiseLMDGhost<MemoryDB>>;
+
 /// The beacon chain harness simulates a single beacon node with `validator_count` validators connected
 /// to it. Each validator is provided a borrow to the beacon chain, where it may read
 /// information and submit blocks/attestations for processing.
@@ -23,7 +25,7 @@ use types::{test_utils::TestingBeaconStateBuilder, *};
 /// is not useful for testing that multiple beacon nodes can reach consensus.
 pub struct BeaconChainHarness {
     pub db: Arc<MemoryDB>,
-    pub beacon_chain: Arc<BeaconChain<MemoryDB, TestingSlotClock, BitwiseLMDGhost<MemoryDB>>>,
+    pub beacon_chain: Arc<TestingBeaconChain>,
     pub block_store: Arc<BeaconBlockStore<MemoryDB>>,
     pub state_store: Arc<BeaconStateStore<MemoryDB>>,
     pub validators: Vec<ValidatorHarness>,
@@ -36,19 +38,39 @@ impl BeaconChainHarness {
     /// - A keypair, `BlockProducer` and `Attester` for each validator.
     /// - A new BeaconChain struct where the given validators are in the genesis.
     pub fn new(spec: ChainSpec, validator_count: usize) -> Self {
+        let state_builder =
+            TestingBeaconStateBuilder::from_default_keypairs_file_if_exists(validator_count, &spec);
+        Self::from_beacon_state_builder(state_builder, spec)
+    }
+
+    pub fn from_beacon_state_builder(
+        state_builder: TestingBeaconStateBuilder,
+        spec: ChainSpec,
+    ) -> Self {
         let db = Arc::new(MemoryDB::open());
         let block_store = Arc::new(BeaconBlockStore::new(db.clone()));
         let state_store = Arc::new(BeaconStateStore::new(db.clone()));
         let slot_clock = TestingSlotClock::new(spec.genesis_slot.as_u64());
         let fork_choice = BitwiseLMDGhost::new(block_store.clone(), state_store.clone());
 
-        let state_builder =
-            TestingBeaconStateBuilder::from_default_keypairs_file_if_exists(validator_count, &spec);
-        let (genesis_state, keypairs) = state_builder.build();
+        let (mut genesis_state, keypairs) = state_builder.build();
 
         let mut genesis_block = BeaconBlock::empty(&spec);
         genesis_block.state_root = Hash256::from_slice(&genesis_state.hash_tree_root());
 
+        genesis_state
+            .build_epoch_cache(RelativeEpoch::Previous, &spec)
+            .unwrap();
+        genesis_state
+            .build_epoch_cache(RelativeEpoch::Current, &spec)
+            .unwrap();
+        genesis_state
+            .build_epoch_cache(RelativeEpoch::NextWithoutRegistryChange, &spec)
+            .unwrap();
+        genesis_state
+            .build_epoch_cache(RelativeEpoch::NextWithRegistryChange, &spec)
+            .unwrap();
+
         // Create the Beacon Chain
         let beacon_chain = Arc::new(
             BeaconChain::from_genesis(
@@ -109,7 +131,9 @@ impl BeaconChainHarness {
         );
 
         self.beacon_chain.slot_clock.set_slot(slot.as_u64());
-        self.beacon_chain.advance_state(slot).unwrap();
+        self.beacon_chain
+            .catchup_state()
+            .expect("Failed to catch state");
         slot
     }
 
@@ -187,7 +211,6 @@ impl BeaconChainHarness {
         self.increment_beacon_chain_slot();
 
         // Produce a new block.
-        debug!("Producing block...");
         let block = self.produce_block();
         debug!("Submitting block for processing...");
         match self.beacon_chain.process_block(block) {

beacon_node/eth2-libp2p/Cargo.toml

@@ -5,8 +5,9 @@ authors = ["Age Manning <Age@AgeManning.com>"]
 edition = "2018"
 
 [dependencies]
+beacon_chain =  { path = "../beacon_chain" }
 # SigP repository until PR is merged
-libp2p =  { git = "https://github.com/SigP/rust-libp2p", branch = "gossipsub" }
+libp2p =  { git = "https://github.com/SigP/rust-libp2p", rev = "b3c32d9a821ae6cc89079499cc6e8a6bab0bffc3" }
 types = { path =  "../../eth2/types" }
 ssz = { path = "../../eth2/utils/ssz" }
 ssz_derive = { path = "../../eth2/utils/ssz_derive" }

beacon_node/eth2-libp2p/src/behaviour.rs

@@ -1,11 +1,21 @@
+use crate::rpc::methods::BlockRootSlot;
 use crate::rpc::{RPCEvent, RPCMessage, Rpc};
+use crate::NetworkConfig;
 use futures::prelude::*;
 use libp2p::{
-    core::swarm::{NetworkBehaviourAction, NetworkBehaviourEventProcess},
-    gossipsub::{Gossipsub, GossipsubConfig, GossipsubEvent},
+    core::{
+        swarm::{NetworkBehaviourAction, NetworkBehaviourEventProcess},
+        PublicKey,
+    },
+    gossipsub::{Gossipsub, GossipsubEvent},
+    identify::{protocol::IdentifyInfo, Identify, IdentifyEvent},
+    ping::{Ping, PingEvent},
     tokio_io::{AsyncRead, AsyncWrite},
     NetworkBehaviour, PeerId,
 };
+use slog::{debug, o};
+use ssz_derive::{Decode, Encode};
+use types::Attestation;
 use types::Topic;
 
 /// Builds the network behaviour for the libp2p Swarm.
@@ -13,12 +23,22 @@ use types::Topic;
 #[derive(NetworkBehaviour)]
 #[behaviour(out_event = "BehaviourEvent", poll_method = "poll")]
 pub struct Behaviour<TSubstream: AsyncRead + AsyncWrite> {
+    /// The routing pub-sub mechanism for eth2.
     gossipsub: Gossipsub<TSubstream>,
     // TODO: Add Kademlia for peer discovery
     /// The events generated by this behaviour to be consumed in the swarm poll.
     serenity_rpc: Rpc<TSubstream>,
+    /// Allows discovery of IP addresses for peers on the network.
+    identify: Identify<TSubstream>,
+    /// Keep regular connection to peers and disconnect if absent.
+    // TODO: Keepalive, likely remove this later.
+    // TODO: Make the ping time customizeable.
+    ping: Ping<TSubstream>,
     #[behaviour(ignore)]
     events: Vec<BehaviourEvent>,
+    /// Logger for behaviour actions.
+    #[behaviour(ignore)]
+    log: slog::Logger,
 }
 
 // Implement the NetworkBehaviourEventProcess trait so that we can derive NetworkBehaviour for Behaviour
@@ -53,12 +73,54 @@ impl<TSubstream: AsyncRead + AsyncWrite> NetworkBehaviourEventProcess<RPCMessage
     }
 }
 
+impl<TSubstream: AsyncRead + AsyncWrite> NetworkBehaviourEventProcess<IdentifyEvent>
+    for Behaviour<TSubstream>
+{
+    fn inject_event(&mut self, event: IdentifyEvent) {
+        match event {
+            IdentifyEvent::Identified {
+                peer_id, mut info, ..
+            } => {
+                if info.listen_addrs.len() > 20 {
+                    debug!(
+                        self.log,
+                        "More than 20 peers have been identified, truncating"
+                    );
+                    info.listen_addrs.truncate(20);
+                }
+                self.events.push(BehaviourEvent::Identified(peer_id, info));
+            }
+            IdentifyEvent::Error { .. } => {}
+            IdentifyEvent::SendBack { .. } => {}
+        }
+    }
+}
+
+impl<TSubstream: AsyncRead + AsyncWrite> NetworkBehaviourEventProcess<PingEvent>
+    for Behaviour<TSubstream>
+{
+    fn inject_event(&mut self, _event: PingEvent) {
+        // not interested in ping responses at the moment.
+    }
+}
+
 impl<TSubstream: AsyncRead + AsyncWrite> Behaviour<TSubstream> {
-    pub fn new(local_peer_id: PeerId, gs_config: GossipsubConfig, log: &slog::Logger) -> Self {
+    pub fn new(local_public_key: PublicKey, net_conf: &NetworkConfig, log: &slog::Logger) -> Self {
+        let local_peer_id = local_public_key.clone().into_peer_id();
+        let identify_config = net_conf.identify_config.clone();
+        let behaviour_log = log.new(o!());
+
         Behaviour {
-            gossipsub: Gossipsub::new(local_peer_id, gs_config),
+            gossipsub: Gossipsub::new(local_peer_id, net_conf.gs_config.clone()),
             serenity_rpc: Rpc::new(log),
+            identify: Identify::new(
+                identify_config.version,
+                identify_config.user_agent,
+                local_public_key,
+            ),
+            ping: Ping::new(),
             events: Vec::new(),
+            log: behaviour_log,
         }
     }
 
@@ -91,6 +153,25 @@ impl<TSubstream: AsyncRead + AsyncWrite> Behaviour<TSubstream> {
 pub enum BehaviourEvent {
     RPC(PeerId, RPCEvent),
     PeerDialed(PeerId),
+    Identified(PeerId, IdentifyInfo),
     // TODO: This is a stub at the moment
     Message(String),
 }
+
+#[derive(Debug, Clone)]
+pub enum IncomingGossip {
+    Block(BlockGossip),
+    Attestation(AttestationGossip),
+}
+
+/// Gossipsub message providing notification of a new block.
+#[derive(Encode, Decode, Clone, Debug, PartialEq)]
+pub struct BlockGossip {
+    pub root: BlockRootSlot,
+}
+
+/// Gossipsub message providing notification of a new attestation.
+#[derive(Encode, Decode, Clone, Debug, PartialEq)]
+pub struct AttestationGossip {
+    pub attestation: Attestation,
+}

beacon_node/eth2-libp2p/src/config.rs

@@ -1,11 +1,9 @@
 use crate::Multiaddr;
 use libp2p::gossipsub::{GossipsubConfig, GossipsubConfigBuilder};
-use libp2p::secio;
-use std::fmt;
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 /// Network configuration for lighthouse.
-pub struct NetworkConfig {
+pub struct Config {
     //TODO: stubbing networking initial params, change in the future
     /// IP address to listen on.
     pub listen_addresses: Vec<Multiaddr>,
@@ -13,47 +11,58 @@ pub struct NetworkConfig {
     pub listen_port: u16,
     /// Gossipsub configuration parameters.
     pub gs_config: GossipsubConfig,
+    /// Configuration parameters for node identification protocol.
+    pub identify_config: IdentifyConfig,
     /// List of nodes to initially connect to.
     pub boot_nodes: Vec<Multiaddr>,
-    /// Peer key related to this nodes PeerId.
-    pub local_private_key: secio::SecioKeyPair,
     /// Client version
     pub client_version: String,
     /// List of topics to subscribe to as strings
     pub topics: Vec<String>,
 }
 
-impl Default for NetworkConfig {
+impl Default for Config {
     /// Generate a default network configuration.
     fn default() -> Self {
-        // TODO: Currently using secp256k1 key pairs. Wire protocol specifies RSA. Waiting for this
-        // PR to be merged to generate RSA keys: https://github.com/briansmith/ring/pull/733
-
-        NetworkConfig {
+        Config {
             listen_addresses: vec!["/ip4/127.0.0.1/tcp/9000"
                 .parse()
                 .expect("is a correct multi-address")],
             listen_port: 9000,
-            gs_config: GossipsubConfigBuilder::new().build(),
+            gs_config: GossipsubConfigBuilder::new()
+                .max_gossip_size(4_000_000)
+                .build(),
+            identify_config: IdentifyConfig::default(),
             boot_nodes: Vec::new(),
-            local_private_key: secio::SecioKeyPair::secp256k1_generated().unwrap(),
             client_version: version::version(),
             topics: vec![String::from("beacon_chain")],
         }
     }
 }
 
-impl NetworkConfig {
+impl Config {
     pub fn new(boot_nodes: Vec<Multiaddr>) -> Self {
-        let mut conf = NetworkConfig::default();
+        let mut conf = Config::default();
         conf.boot_nodes = boot_nodes;
 
         conf
     }
 }
 
-impl fmt::Debug for NetworkConfig {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "NetworkConfig: listen_addresses: {:?}, listen_port: {:?}, gs_config: {:?}, boot_nodes: {:?}, local_private_key: <Secio-PubKey {:?}>, client_version: {:?}", self.listen_addresses, self.listen_port, self.gs_config, self.boot_nodes, self.local_private_key.to_public_key(), self.client_version)
+/// The configuration parameters for the Identify protocol
+#[derive(Debug, Clone)]
+pub struct IdentifyConfig {
+    /// The protocol version to listen on.
+    pub version: String,
+    /// The client's name and version for identification.
+    pub user_agent: String,
+}
+
+impl Default for IdentifyConfig {
+    fn default() -> Self {
+        Self {
+            version: "/eth/serenity/1.0".to_string(),
+            user_agent: version::version(),
+        }
     }
 }

beacon_node/eth2-libp2p/src/lib.rs

@@ -3,16 +3,16 @@
 ///
 /// This crate builds and manages the libp2p services required by the beacon node.
 pub mod behaviour;
+mod config;
 pub mod error;
-mod network_config;
 pub mod rpc;
 mod service;
 
+pub use config::Config as NetworkConfig;
 pub use libp2p::{
     gossipsub::{GossipsubConfig, GossipsubConfigBuilder},
     PeerId,
 };
-pub use network_config::NetworkConfig;
 pub use rpc::{HelloMessage, RPCEvent};
 pub use service::Libp2pEvent;
 pub use service::Service;

beacon_node/eth2-libp2p/src/rpc/methods.rs

@@ -1,6 +1,7 @@
+use ssz::{Decodable, DecodeError, Encodable, SszStream};
 /// Available RPC methods types and ids.
 use ssz_derive::{Decode, Encode};
-use types::{BeaconBlockBody, BeaconBlockHeader, Epoch, Hash256, Slot};
+use types::{Attestation, BeaconBlockBody, BeaconBlockHeader, Epoch, Hash256, Slot};
 
 #[derive(Debug)]
 /// Available Serenity Libp2p RPC methods
@@ -53,13 +54,27 @@ impl Into<u16> for RPCMethod {
 #[derive(Debug, Clone)]
 pub enum RPCRequest {
     Hello(HelloMessage),
-    Goodbye(u64),
+    Goodbye(GoodbyeReason),
     BeaconBlockRoots(BeaconBlockRootsRequest),
     BeaconBlockHeaders(BeaconBlockHeadersRequest),
     BeaconBlockBodies(BeaconBlockBodiesRequest),
     BeaconChainState(BeaconChainStateRequest),
 }
 
+impl RPCRequest {
+    pub fn method_id(&self) -> u16 {
+        let method = match self {
+            RPCRequest::Hello(_) => RPCMethod::Hello,
+            RPCRequest::Goodbye(_) => RPCMethod::Goodbye,
+            RPCRequest::BeaconBlockRoots(_) => RPCMethod::BeaconBlockRoots,
+            RPCRequest::BeaconBlockHeaders(_) => RPCMethod::BeaconBlockHeaders,
+            RPCRequest::BeaconBlockBodies(_) => RPCMethod::BeaconBlockBodies,
+            RPCRequest::BeaconChainState(_) => RPCMethod::BeaconChainState,
+        };
+        method.into()
+    }
+}
+
 #[derive(Debug, Clone)]
 pub enum RPCResponse {
     Hello(HelloMessage),
@@ -69,6 +84,19 @@ pub enum RPCResponse {
     BeaconChainState(BeaconChainStateResponse),
 }
 
+impl RPCResponse {
+    pub fn method_id(&self) -> u16 {
+        let method = match self {
+            RPCResponse::Hello(_) => RPCMethod::Hello,
+            RPCResponse::BeaconBlockRoots(_) => RPCMethod::BeaconBlockRoots,
+            RPCResponse::BeaconBlockHeaders(_) => RPCMethod::BeaconBlockHeaders,
+            RPCResponse::BeaconBlockBodies(_) => RPCMethod::BeaconBlockBodies,
+            RPCResponse::BeaconChainState(_) => RPCMethod::BeaconChainState,
+        };
+        method.into()
+    }
+}
+
 /* Request/Response data structures for RPC methods */
 
 /// The HELLO request/response handshake message.
@@ -86,76 +114,125 @@ pub struct HelloMessage {
     pub best_slot: Slot,
 }
 
+/// The reason given for a `Goodbye` message.
+///
+/// Note: any unknown `u64::into(n)` will resolve to `GoodbyeReason::Unknown` for any unknown `n`,
+/// however `GoodbyeReason::Unknown.into()` will go into `0_u64`. Therefore de-serializing then
+/// re-serializing may not return the same bytes.
+#[derive(Debug, Clone)]
+pub enum GoodbyeReason {
+    ClientShutdown,
+    IrreleventNetwork,
+    Fault,
+    Unknown,
+}
+
+impl From<u64> for GoodbyeReason {
+    fn from(id: u64) -> GoodbyeReason {
+        match id {
+            1 => GoodbyeReason::ClientShutdown,
+            2 => GoodbyeReason::IrreleventNetwork,
+            3 => GoodbyeReason::Fault,
+            _ => GoodbyeReason::Unknown,
+        }
+    }
+}
+
+impl Into<u64> for GoodbyeReason {
+    fn into(self) -> u64 {
+        match self {
+            GoodbyeReason::Unknown => 0,
+            GoodbyeReason::ClientShutdown => 1,
+            GoodbyeReason::IrreleventNetwork => 2,
+            GoodbyeReason::Fault => 3,
+        }
+    }
+}
+
+impl Encodable for GoodbyeReason {
+    fn ssz_append(&self, s: &mut SszStream) {
+        let id: u64 = (*self).clone().into();
+        id.ssz_append(s);
+    }
+}
+
+impl Decodable for GoodbyeReason {
+    fn ssz_decode(bytes: &[u8], index: usize) -> Result<(Self, usize), DecodeError> {
+        let (id, index) = u64::ssz_decode(bytes, index)?;
+        Ok((Self::from(id), index))
+    }
+}
+
 /// Request a number of beacon block roots from a peer.
-#[derive(Encode, Decode, Clone, Debug)]
+#[derive(Encode, Decode, Clone, Debug, PartialEq)]
 pub struct BeaconBlockRootsRequest {
     /// The starting slot of the requested blocks.
-    start_slot: Slot,
+    pub start_slot: Slot,
     /// The number of blocks from the start slot.
-    count: u64, // this must be less than 32768. //TODO: Enforce this in the lower layers
+    pub count: u64, // this must be less than 32768. //TODO: Enforce this in the lower layers
 }
 
 /// Response containing a number of beacon block roots from a peer.
-#[derive(Encode, Decode, Clone, Debug)]
+#[derive(Encode, Decode, Clone, Debug, PartialEq)]
 pub struct BeaconBlockRootsResponse {
     /// List of requested blocks and associated slots.
-    roots: Vec<BlockRootSlot>,
+    pub roots: Vec<BlockRootSlot>,
 }
 
 /// Contains a block root and associated slot.
-#[derive(Encode, Decode, Clone, Debug)]
+#[derive(Encode, Decode, Clone, Debug, PartialEq)]
 pub struct BlockRootSlot {
     /// The block root.
-    block_root: Hash256,
+    pub block_root: Hash256,
     /// The block slot.
-    slot: Slot,
+    pub slot: Slot,
 }
 
 /// Request a number of beacon block headers from a peer.
-#[derive(Encode, Decode, Clone, Debug)]
+#[derive(Encode, Decode, Clone, Debug, PartialEq)]
 pub struct BeaconBlockHeadersRequest {
     /// The starting header hash of the requested headers.
-    start_root: Hash256,
+    pub start_root: Hash256,
     /// The starting slot of the requested headers.
-    start_slot: Slot,
+    pub start_slot: Slot,
     /// The maximum number of headers than can be returned.
-    max_headers: u64,
+    pub max_headers: u64,
     /// The maximum number of slots to skip between blocks.
-    skip_slots: u64,
+    pub skip_slots: u64,
 }
 
 /// Response containing requested block headers.
-#[derive(Encode, Decode, Clone, Debug)]
+#[derive(Encode, Decode, Clone, Debug, PartialEq)]
 pub struct BeaconBlockHeadersResponse {
     /// The list of requested beacon block headers.
-    headers: Vec<BeaconBlockHeader>,
+    pub headers: Vec<BeaconBlockHeader>,
 }
 
 /// Request a number of beacon block bodies from a peer.
-#[derive(Encode, Decode, Clone, Debug)]
+#[derive(Encode, Decode, Clone, Debug, PartialEq)]
 pub struct BeaconBlockBodiesRequest {
     /// The list of beacon block bodies being requested.
-    block_roots: Hash256,
+    pub block_roots: Vec<Hash256>,
 }
 
 /// Response containing the list of requested beacon block bodies.
-#[derive(Encode, Decode, Clone, Debug)]
+#[derive(Encode, Decode, Clone, Debug, PartialEq)]
 pub struct BeaconBlockBodiesResponse {
     /// The list of beacon block bodies being requested.
-    block_bodies: Vec<BeaconBlockBody>,
+    pub block_bodies: Vec<BeaconBlockBody>,
 }
 
 /// Request values for tree hashes which yield a blocks `state_root`.
-#[derive(Encode, Decode, Clone, Debug)]
+#[derive(Encode, Decode, Clone, Debug, PartialEq)]
 pub struct BeaconChainStateRequest {
     /// The tree hashes that a value is requested for.
-    hashes: Vec<Hash256>,
+    pub hashes: Vec<Hash256>,
 }
 
 /// Request values for tree hashes which yield a blocks `state_root`.
 // Note: TBD
-#[derive(Encode, Decode, Clone, Debug)]
+#[derive(Encode, Decode, Clone, Debug, PartialEq)]
 pub struct BeaconChainStateResponse {
     /// The values corresponding the to the requested tree hashes.
-    values: bool, //TBD - stubbed with encodeable bool
+    pub values: bool, //TBD - stubbed with encodeable bool
 }

beacon_node/eth2-libp2p/src/rpc/mod.rs

@@ -2,7 +2,7 @@
 ///
 /// This is purpose built for Ethereum 2.0 serenity and the protocol listens on
 /// `/eth/serenity/rpc/1.0.0`
-mod methods;
+pub mod methods;
 mod protocol;
 
 use futures::prelude::*;
@@ -12,7 +12,7 @@ use libp2p::core::swarm::{
 };
 use libp2p::{Multiaddr, PeerId};
 pub use methods::{HelloMessage, RPCMethod, RPCRequest, RPCResponse};
-pub use protocol::{RPCEvent, RPCProtocol};
+pub use protocol::{RPCEvent, RPCProtocol, RequestId};
 use slog::o;
 use std::marker::PhantomData;
 use tokio::io::{AsyncRead, AsyncWrite};

beacon_node/eth2-libp2p/src/rpc/protocol.rs

@@ -1,12 +1,13 @@
-use super::methods::{HelloMessage, RPCMethod, RPCRequest, RPCResponse};
+use super::methods::*;
 use libp2p::core::{upgrade, InboundUpgrade, OutboundUpgrade, UpgradeInfo};
-use ssz::{ssz_encode, Decodable, Encodable, SszStream};
+use ssz::{ssz_encode, Decodable, DecodeError as SSZDecodeError, Encodable, SszStream};
+use std::hash::{Hash, Hasher};
 use std::io;
 use std::iter;
 use tokio::io::{AsyncRead, AsyncWrite};
 
 /// The maximum bytes that can be sent across the RPC.
-const MAX_READ_SIZE: usize = 2048;
+const MAX_READ_SIZE: usize = 4_194_304; // 4M
 
 /// Implementation of the `ConnectionUpgrade` for the rpc protocol.
 
@@ -29,16 +30,65 @@ impl Default for RPCProtocol {
     }
 }
 
+/// A monotonic counter for ordering `RPCRequest`s.
+#[derive(Debug, Clone, PartialEq, Default)]
+pub struct RequestId(u64);
+
+impl RequestId {
+    /// Increment the request id.
+    pub fn increment(&mut self) {
+        self.0 += 1
+    }
+
+    /// Return the previous id.
+    pub fn previous(&self) -> Self {
+        Self(self.0 - 1)
+    }
+}
+
+impl Eq for RequestId {}
+
+impl Hash for RequestId {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.0.hash(state);
+    }
+}
+
+impl From<u64> for RequestId {
+    fn from(x: u64) -> RequestId {
+        RequestId(x)
+    }
+}
+
+impl Into<u64> for RequestId {
+    fn into(self) -> u64 {
+        self.0
+    }
+}
+
+impl Encodable for RequestId {
+    fn ssz_append(&self, s: &mut SszStream) {
+        self.0.ssz_append(s);
+    }
+}
+
+impl Decodable for RequestId {
+    fn ssz_decode(bytes: &[u8], index: usize) -> Result<(Self, usize), SSZDecodeError> {
+        let (id, index) = u64::ssz_decode(bytes, index)?;
+        Ok((Self::from(id), index))
+    }
+}
+
 /// The RPC types which are sent/received in this protocol.
 #[derive(Debug, Clone)]
 pub enum RPCEvent {
     Request {
-        id: u64,
+        id: RequestId,
         method_id: u16,
         body: RPCRequest,
     },
     Response {
-        id: u64,
+        id: RequestId,
         method_id: u16, //TODO: Remove and process decoding upstream
         result: RPCResponse,
     },
@@ -60,10 +110,13 @@ where
 {
     type Output = RPCEvent;
     type Error = DecodeError;
-    type Future =
-        upgrade::ReadOneThen<TSocket, (), fn(Vec<u8>, ()) -> Result<RPCEvent, DecodeError>>;
+    type Future = upgrade::ReadOneThen<
+        upgrade::Negotiated<TSocket>,
+        (),
+        fn(Vec<u8>, ()) -> Result<RPCEvent, DecodeError>,
+    >;
 
-    fn upgrade_inbound(self, socket: TSocket, _: Self::Info) -> Self::Future {
+    fn upgrade_inbound(self, socket: upgrade::Negotiated<TSocket>, _: Self::Info) -> Self::Future {
         upgrade::read_one_then(socket, MAX_READ_SIZE, (), |packet, ()| Ok(decode(packet)?))
     }
 }
@@ -72,7 +125,7 @@ fn decode(packet: Vec<u8>) -> Result<RPCEvent, DecodeError> {
     // decode the header of the rpc
     // request/response
     let (request, index) = bool::ssz_decode(&packet, 0)?;
-    let (id, index) = u64::ssz_decode(&packet, index)?;
+    let (id, index) = RequestId::ssz_decode(&packet, index)?;
     let (method_id, index) = u16::ssz_decode(&packet, index)?;
 
     if request {
@@ -81,7 +134,31 @@ fn decode(packet: Vec<u8>) -> Result<RPCEvent, DecodeError> {
                 let (hello_body, _index) = HelloMessage::ssz_decode(&packet, index)?;
                 RPCRequest::Hello(hello_body)
             }
-            RPCMethod::Unknown | _ => return Err(DecodeError::UnknownRPCMethod),
+            RPCMethod::Goodbye => {
+                let (goodbye_reason, _index) = GoodbyeReason::ssz_decode(&packet, index)?;
+                RPCRequest::Goodbye(goodbye_reason)
+            }
+            RPCMethod::BeaconBlockRoots => {
+                let (block_roots_request, _index) =
+                    BeaconBlockRootsRequest::ssz_decode(&packet, index)?;
+                RPCRequest::BeaconBlockRoots(block_roots_request)
+            }
+            RPCMethod::BeaconBlockHeaders => {
+                let (block_headers_request, _index) =
+                    BeaconBlockHeadersRequest::ssz_decode(&packet, index)?;
+                RPCRequest::BeaconBlockHeaders(block_headers_request)
+            }
+            RPCMethod::BeaconBlockBodies => {
+                let (block_bodies_request, _index) =
+                    BeaconBlockBodiesRequest::ssz_decode(&packet, index)?;
+                RPCRequest::BeaconBlockBodies(block_bodies_request)
+            }
+            RPCMethod::BeaconChainState => {
+                let (chain_state_request, _index) =
+                    BeaconChainStateRequest::ssz_decode(&packet, index)?;
+                RPCRequest::BeaconChainState(chain_state_request)
+            }
+            RPCMethod::Unknown => return Err(DecodeError::UnknownRPCMethod),
         };
 
         Ok(RPCEvent::Request {
@@ -97,7 +174,24 @@ fn decode(packet: Vec<u8>) -> Result<RPCEvent, DecodeError> {
                 let (body, _index) = HelloMessage::ssz_decode(&packet, index)?;
                 RPCResponse::Hello(body)
             }
-            RPCMethod::Unknown | _ => return Err(DecodeError::UnknownRPCMethod),
+            RPCMethod::Goodbye => unreachable!("Should never receive a goodbye response"),
+            RPCMethod::BeaconBlockRoots => {
+                let (body, _index) = BeaconBlockRootsResponse::ssz_decode(&packet, index)?;
+                RPCResponse::BeaconBlockRoots(body)
+            }
+            RPCMethod::BeaconBlockHeaders => {
+                let (body, _index) = BeaconBlockHeadersResponse::ssz_decode(&packet, index)?;
+                RPCResponse::BeaconBlockHeaders(body)
+            }
+            RPCMethod::BeaconBlockBodies => {
+                let (body, _index) = BeaconBlockBodiesResponse::ssz_decode(&packet, index)?;
+                RPCResponse::BeaconBlockBodies(body)
+            }
+            RPCMethod::BeaconChainState => {
+                let (body, _index) = BeaconChainStateResponse::ssz_decode(&packet, index)?;
+                RPCResponse::BeaconChainState(body)
+            }
+            RPCMethod::Unknown => return Err(DecodeError::UnknownRPCMethod),
         };
         Ok(RPCEvent::Response {
             id,
@@ -113,10 +207,10 @@ where
 {
     type Output = ();
     type Error = io::Error;
-    type Future = upgrade::WriteOne<TSocket>;
+    type Future = upgrade::WriteOne<upgrade::Negotiated<TSocket>>;
 
     #[inline]
-    fn upgrade_outbound(self, socket: TSocket, _: Self::Info) -> Self::Future {
+    fn upgrade_outbound(self, socket: upgrade::Negotiated<TSocket>, _: Self::Info) -> Self::Future {
         let bytes = ssz_encode(&self);
         upgrade::write_one(socket, bytes)
     }
@@ -137,7 +231,21 @@ impl Encodable for RPCEvent {
                     RPCRequest::Hello(body) => {
                         s.append(body);
                     }
-                    _ => {}
+                    RPCRequest::Goodbye(body) => {
+                        s.append(body);
+                    }
+                    RPCRequest::BeaconBlockRoots(body) => {
+                        s.append(body);
+                    }
+                    RPCRequest::BeaconBlockHeaders(body) => {
+                        s.append(body);
+                    }
+                    RPCRequest::BeaconBlockBodies(body) => {
+                        s.append(body);
+                    }
+                    RPCRequest::BeaconChainState(body) => {
+                        s.append(body);
+                    }
                 }
             }
             RPCEvent::Response {
@@ -152,7 +260,18 @@ impl Encodable for RPCEvent {
                     RPCResponse::Hello(response) => {
                         s.append(response);
                     }
-                    _ => {}
+                    RPCResponse::BeaconBlockRoots(response) => {
+                        s.append(response);
+                    }
+                    RPCResponse::BeaconBlockHeaders(response) => {
+                        s.append(response);
+                    }
+                    RPCResponse::BeaconBlockBodies(response) => {
+                        s.append(response);
+                    }
+                    RPCResponse::BeaconChainState(response) => {
+                        s.append(response);
+                    }
                 }
             }
         }

beacon_node/eth2-libp2p/src/service.rs

@@ -6,13 +6,14 @@ use crate::NetworkConfig;
 use futures::prelude::*;
 use futures::Stream;
 use libp2p::core::{
+    identity,
     muxing::StreamMuxerBox,
     nodes::Substream,
     transport::boxed::Boxed,
     upgrade::{InboundUpgradeExt, OutboundUpgradeExt},
 };
-use libp2p::{core, secio, Transport};
-use libp2p::{PeerId, Swarm};
+use libp2p::identify::protocol::IdentifyInfo;
+use libp2p::{core, secio, PeerId, Swarm, Transport};
 use slog::{debug, info, trace, warn};
 use std::io::{Error, ErrorKind};
 use std::time::Duration;
@@ -33,15 +34,20 @@ impl Service {
     pub fn new(config: NetworkConfig, log: slog::Logger) -> error::Result<Self> {
         debug!(log, "Libp2p Service starting");
 
-        let local_private_key = config.local_private_key;
-        let local_peer_id = local_private_key.to_peer_id();
+        // TODO: Currently using secp256k1 key pairs. Wire protocol specifies RSA. Waiting for this
+        // PR to be merged to generate RSA keys: https://github.com/briansmith/ring/pull/733
+        // TODO: Save and recover node key from disk
+        let local_private_key = identity::Keypair::generate_secp256k1();
+
+        let local_public_key = local_private_key.public();
+        let local_peer_id = PeerId::from(local_private_key.public());
         info!(log, "Local peer id: {:?}", local_peer_id);
 
         let mut swarm = {
             // Set up the transport
             let transport = build_transport(local_private_key);
             // Set up gossipsub routing
-            let behaviour = Behaviour::new(local_peer_id.clone(), config.gs_config, &log);
+            let behaviour = Behaviour::new(local_public_key.clone(), &config, &log);
             // Set up Topology
             let topology = local_peer_id.clone();
             Swarm::new(transport, behaviour, topology)
@@ -99,17 +105,23 @@ impl Stream for Service {
             // TODO: Currently only gossipsub events passed here.
             // Build a type for more generic events
             match self.swarm.poll() {
-                Ok(Async::Ready(Some(BehaviourEvent::Message(m)))) => {
+                //Behaviour events
+                Ok(Async::Ready(Some(event))) => match event {
                     // TODO: Stub here for debugging
-                    debug!(self.log, "Message received: {}", m);
-                    return Ok(Async::Ready(Some(Libp2pEvent::Message(m))));
-                }
-                Ok(Async::Ready(Some(BehaviourEvent::RPC(peer_id, event)))) => {
-                    return Ok(Async::Ready(Some(Libp2pEvent::RPC(peer_id, event))));
-                }
-                Ok(Async::Ready(Some(BehaviourEvent::PeerDialed(peer_id)))) => {
-                    return Ok(Async::Ready(Some(Libp2pEvent::PeerDialed(peer_id))));
-                }
+                    BehaviourEvent::Message(m) => {
+                        debug!(self.log, "Message received: {}", m);
+                        return Ok(Async::Ready(Some(Libp2pEvent::Message(m))));
+                    }
+                    BehaviourEvent::RPC(peer_id, event) => {
+                        return Ok(Async::Ready(Some(Libp2pEvent::RPC(peer_id, event))));
+                    }
+                    BehaviourEvent::PeerDialed(peer_id) => {
+                        return Ok(Async::Ready(Some(Libp2pEvent::PeerDialed(peer_id))));
+                    }
+                    BehaviourEvent::Identified(peer_id, info) => {
+                        return Ok(Async::Ready(Some(Libp2pEvent::Identified(peer_id, info))));
+                    }
+                },
                 Ok(Async::Ready(None)) => unreachable!("Swarm stream shouldn't end"),
                 Ok(Async::NotReady) => break,
                 _ => break,
@@ -121,9 +133,7 @@ impl Stream for Service {
 
 /// The implementation supports TCP/IP, WebSockets over TCP/IP, secio as the encryption layer, and
 /// mplex or yamux as the multiplexing layer.
-fn build_transport(
-    local_private_key: secio::SecioKeyPair,
-) -> Boxed<(PeerId, StreamMuxerBox), Error> {
+fn build_transport(local_private_key: identity::Keypair) -> Boxed<(PeerId, StreamMuxerBox), Error> {
     // TODO: The Wire protocol currently doesn't specify encryption and this will need to be customised
     // in the future.
     let transport = libp2p::tcp::TcpConfig::new();
@@ -156,8 +166,12 @@ fn build_transport(
 
 /// Events that can be obtained from polling the Libp2p Service.
 pub enum Libp2pEvent {
-    // We have received an RPC event on the swarm
+    /// An RPC response request has been received on the swarm.
     RPC(PeerId, RPCEvent),
+    /// Initiated the connection to a new peer.
     PeerDialed(PeerId),
+    /// Received information about a peer on the network.
+    Identified(PeerId, IdentifyInfo),
+    // TODO: Pub-sub testing only.
     Message(String),
 }

beacon_node/network/Cargo.toml

@@ -4,12 +4,17 @@ version = "0.1.0"
 authors = ["Age Manning <Age@AgeManning.com>"]
 edition = "2018"
 
+[dev-dependencies]
+test_harness = { path = "../beacon_chain/test_harness" }
+sloggers = "0.3.2"
+
 [dependencies]
 beacon_chain =  { path = "../beacon_chain" }
 eth2-libp2p =  { path = "../eth2-libp2p" }
 version = { path = "../version" }
 types = { path = "../../eth2/types" }
 slog = "2.4.1"
+ssz = { path = "../../eth2/utils/ssz" }
 futures = "0.1.25"
 error-chain = "0.12.0"
 crossbeam-channel = "0.3.8"

beacon_node/network/src/beacon_chain.rs

@@ -5,8 +5,12 @@ use beacon_chain::{
     parking_lot::RwLockReadGuard,
     slot_clock::SlotClock,
     types::{BeaconState, ChainSpec},
-    CheckPoint,
+    AggregationOutcome, CheckPoint,
 };
+use eth2_libp2p::HelloMessage;
+use types::{Attestation, BeaconBlock, BeaconBlockBody, BeaconBlockHeader, Epoch, Hash256, Slot};
+
+pub use beacon_chain::{BeaconChainError, BlockProcessingOutcome};
 
 /// The network's API to the beacon chain.
 pub trait BeaconChain: Send + Sync {
@@ -14,9 +18,48 @@ pub trait BeaconChain: Send + Sync {
 
     fn get_state(&self) -> RwLockReadGuard<BeaconState>;
 
+    fn slot(&self) -> Slot;
+
     fn head(&self) -> RwLockReadGuard<CheckPoint>;
 
+    fn get_block(&self, block_root: &Hash256) -> Result<Option<BeaconBlock>, BeaconChainError>;
+
+    fn best_slot(&self) -> Slot;
+
+    fn best_block_root(&self) -> Hash256;
+
     fn finalized_head(&self) -> RwLockReadGuard<CheckPoint>;
+
+    fn finalized_epoch(&self) -> Epoch;
+
+    fn hello_message(&self) -> HelloMessage;
+
+    fn process_block(&self, block: BeaconBlock)
+        -> Result<BlockProcessingOutcome, BeaconChainError>;
+
+    fn process_attestation(
+        &self,
+        attestation: Attestation,
+    ) -> Result<AggregationOutcome, BeaconChainError>;
+
+    fn get_block_roots(
+        &self,
+        start_slot: Slot,
+        count: usize,
+        skip: usize,
+    ) -> Result<Vec<Hash256>, BeaconChainError>;
+
+    fn get_block_headers(
+        &self,
+        start_slot: Slot,
+        count: usize,
+        skip: usize,
+    ) -> Result<Vec<BeaconBlockHeader>, BeaconChainError>;
+
+    fn get_block_bodies(&self, roots: &[Hash256])
+        -> Result<Vec<BeaconBlockBody>, BeaconChainError>;
+
+    fn is_new_block_root(&self, beacon_block_root: &Hash256) -> Result<bool, BeaconChainError>;
 }
 
 impl<T, U, F> BeaconChain for RawBeaconChain<T, U, F>
@@ -33,11 +76,93 @@ where
         self.state.read()
     }
 
+    fn slot(&self) -> Slot {
+        self.get_state().slot
+    }
+
     fn head(&self) -> RwLockReadGuard<CheckPoint> {
         self.head()
     }
 
+    fn get_block(&self, block_root: &Hash256) -> Result<Option<BeaconBlock>, BeaconChainError> {
+        self.get_block(block_root)
+    }
+
+    fn finalized_epoch(&self) -> Epoch {
+        self.get_state().finalized_epoch
+    }
+
     fn finalized_head(&self) -> RwLockReadGuard<CheckPoint> {
         self.finalized_head()
     }
+
+    fn best_slot(&self) -> Slot {
+        self.head().beacon_block.slot
+    }
+
+    fn best_block_root(&self) -> Hash256 {
+        self.head().beacon_block_root
+    }
+
+    fn hello_message(&self) -> HelloMessage {
+        let spec = self.get_spec();
+        let state = self.get_state();
+
+        HelloMessage {
+            network_id: spec.network_id,
+            latest_finalized_root: state.finalized_root,
+            latest_finalized_epoch: state.finalized_epoch,
+            best_root: self.best_block_root(),
+            best_slot: self.best_slot(),
+        }
+    }
+
+    fn process_block(
+        &self,
+        block: BeaconBlock,
+    ) -> Result<BlockProcessingOutcome, BeaconChainError> {
+        self.process_block(block)
+    }
+
+    fn process_attestation(
+        &self,
+        _attestation: Attestation,
+    ) -> Result<AggregationOutcome, BeaconChainError> {
+        // Awaiting a proper operations pool before we can import attestations.
+        //
+        // Returning a useless error for now.
+        //
+        // https://github.com/sigp/lighthouse/issues/281
+        return Err(BeaconChainError::DBInconsistent("CANNOT PROCESS".into()));
+    }
+
+    fn get_block_roots(
+        &self,
+        start_slot: Slot,
+        count: usize,
+        skip: usize,
+    ) -> Result<Vec<Hash256>, BeaconChainError> {
+        self.get_block_roots(start_slot, count, skip)
+    }
+
+    fn get_block_headers(
+        &self,
+        start_slot: Slot,
+        count: usize,
+        skip: usize,
+    ) -> Result<Vec<BeaconBlockHeader>, BeaconChainError> {
+        let roots = self.get_block_roots(start_slot, count, skip)?;
+        self.get_block_headers(&roots)
+    }
+
+    fn get_block_bodies(
+        &self,
+        roots: &[Hash256],
+    ) -> Result<Vec<BeaconBlockBody>, BeaconChainError> {
+        self.get_block_bodies(roots)
+    }
+
+    fn is_new_block_root(&self, beacon_block_root: &Hash256) -> Result<bool, BeaconChainError> {
+        self.is_new_block_root(beacon_block_root)
+    }
 }

beacon_node/network/src/lib.rs

@@ -1,8 +1,8 @@
 /// This crate provides the network server for Lighthouse.
 pub mod beacon_chain;
 pub mod error;
-mod message_handler;
-mod service;
+pub mod message_handler;
+pub mod service;
 pub mod sync;
 
 pub use eth2_libp2p::NetworkConfig;

beacon_node/network/src/message_handler.rs

@@ -4,33 +4,29 @@ use crate::service::{NetworkMessage, OutgoingMessage};
 use crate::sync::SimpleSync;
 use crossbeam_channel::{unbounded as channel, Sender};
 use eth2_libp2p::{
-    rpc::{RPCMethod, RPCRequest, RPCResponse},
-    HelloMessage, PeerId, RPCEvent,
+    behaviour::IncomingGossip,
+    rpc::{methods::GoodbyeReason, RPCRequest, RPCResponse, RequestId},
+    PeerId, RPCEvent,
 };
 use futures::future;
-use slog::warn;
-use slog::{debug, trace};
+use slog::{debug, warn};
 use std::collections::HashMap;
 use std::sync::Arc;
-use std::time::{Duration, Instant};
+use std::time::Instant;
 
 /// Timeout for RPC requests.
-const REQUEST_TIMEOUT: Duration = Duration::from_secs(30);
+// const REQUEST_TIMEOUT: Duration = Duration::from_secs(30);
 /// Timeout before banning a peer for non-identification.
-const HELLO_TIMEOUT: Duration = Duration::from_secs(30);
+// const HELLO_TIMEOUT: Duration = Duration::from_secs(30);
 
 /// Handles messages received from the network and client and organises syncing.
 pub struct MessageHandler {
     /// Currently loaded and initialised beacon chain.
-    chain: Arc<BeaconChain>,
+    _chain: Arc<BeaconChain>,
     /// The syncing framework.
     sync: SimpleSync,
-    /// The network channel to relay messages to the Network service.
-    network_send: crossbeam_channel::Sender<NetworkMessage>,
-    /// A mapping of peers and the RPC id we have sent an RPC request to.
-    requests: HashMap<(PeerId, u64), Instant>,
-    /// A counter of request id for each peer.
-    request_ids: HashMap<PeerId, u64>,
+    /// The context required to send messages to, and process messages from peers.
+    network_context: NetworkContext,
     /// The `MessageHandler` logger.
     log: slog::Logger,
 }
@@ -44,8 +40,8 @@ pub enum HandlerMessage {
     PeerDisconnected(PeerId),
     /// An RPC response/request has been received.
     RPC(PeerId, RPCEvent),
-    /// A block has been imported.
-    BlockImported(), //TODO: This comes from pub-sub - decide its contents
+    /// A gossip message has been received.
+    IncomingGossip(PeerId, IncomingGossip),
 }
 
 impl MessageHandler {
@@ -65,13 +61,9 @@ impl MessageHandler {
         let sync = SimpleSync::new(beacon_chain.clone(), &log);
 
         let mut handler = MessageHandler {
-            // TODO: The handler may not need a chain, perhaps only sync?
-            chain: beacon_chain.clone(),
+            _chain: beacon_chain.clone(),
             sync,
-            network_send,
-            requests: HashMap::new(),
-            request_ids: HashMap::new(),
-
+            network_context: NetworkContext::new(network_send, log.clone()),
             log: log.clone(),
         };
 
@@ -93,13 +85,16 @@ impl MessageHandler {
         match message {
             // we have initiated a connection to a peer
             HandlerMessage::PeerDialed(peer_id) => {
-                let id = self.generate_request_id(&peer_id);
-                self.send_hello(peer_id, id, true);
+                self.sync.on_connect(peer_id, &mut self.network_context);
             }
             // we have received an RPC message request/response
             HandlerMessage::RPC(peer_id, rpc_event) => {
                 self.handle_rpc_message(peer_id, rpc_event);
             }
+            // we have received an RPC message request/response
+            HandlerMessage::IncomingGossip(peer_id, gossip) => {
+                self.handle_gossip(peer_id, gossip);
+            }
             //TODO: Handle all messages
             _ => {}
         }
@@ -117,109 +112,195 @@ impl MessageHandler {
     }
 
     /// A new RPC request has been received from the network.
-    fn handle_rpc_request(&mut self, peer_id: PeerId, id: u64, request: RPCRequest) {
+    fn handle_rpc_request(&mut self, peer_id: PeerId, request_id: RequestId, request: RPCRequest) {
+        // TODO: process the `id`.
         match request {
-            RPCRequest::Hello(hello_message) => {
-                self.handle_hello_request(peer_id, id, hello_message)
+            RPCRequest::Hello(hello_message) => self.sync.on_hello_request(
+                peer_id,
+                request_id,
+                hello_message,
+                &mut self.network_context,
+            ),
+            RPCRequest::Goodbye(goodbye_reason) => self.sync.on_goodbye(peer_id, goodbye_reason),
+            RPCRequest::BeaconBlockRoots(request) => self.sync.on_beacon_block_roots_request(
+                peer_id,
+                request_id,
+                request,
+                &mut self.network_context,
+            ),
+            RPCRequest::BeaconBlockHeaders(request) => self.sync.on_beacon_block_headers_request(
+                peer_id,
+                request_id,
+                request,
+                &mut self.network_context,
+            ),
+            RPCRequest::BeaconBlockBodies(request) => self.sync.on_beacon_block_bodies_request(
+                peer_id,
+                request_id,
+                request,
+                &mut self.network_context,
+            ),
+            RPCRequest::BeaconChainState(_) => {
+                // We do not implement this endpoint, it is not required and will only likely be
+                // useful for light-client support in later phases.
+                warn!(self.log, "BeaconChainState RPC call is not supported.");
             }
-            // TODO: Handle all requests
-            _ => {}
         }
     }
 
     /// An RPC response has been received from the network.
     // we match on id and ignore responses past the timeout.
-    fn handle_rpc_response(&mut self, peer_id: PeerId, id: u64, response: RPCResponse) {
-        // if response id is related to a request, ignore (likely RPC timeout)
-        if self.requests.remove(&(peer_id.clone(), id)).is_none() {
-            debug!(self.log, "Unrecognized response from peer: {:?}", peer_id);
+    fn handle_rpc_response(&mut self, peer_id: PeerId, id: RequestId, response: RPCResponse) {
+        // if response id is not related to a request, ignore (likely RPC timeout)
+        if self
+            .network_context
+            .outstanding_outgoing_request_ids
+            .remove(&(peer_id.clone(), id.clone()))
+            .is_none()
+        {
+            warn!(
+                self.log,
+                "Unknown ResponseId for incoming RPCRequest";
+                "peer" => format!("{:?}", peer_id),
+                "request_id" => format!("{:?}", id)
+            );
             return;
         }
+
         match response {
             RPCResponse::Hello(hello_message) => {
-                debug!(self.log, "Hello response received from peer: {:?}", peer_id);
-                self.validate_hello(peer_id, hello_message);
+                self.sync
+                    .on_hello_response(peer_id, hello_message, &mut self.network_context);
+            }
+            RPCResponse::BeaconBlockRoots(response) => {
+                self.sync.on_beacon_block_roots_response(
+                    peer_id,
+                    response,
+                    &mut self.network_context,
+                );
+            }
+            RPCResponse::BeaconBlockHeaders(response) => {
+                self.sync.on_beacon_block_headers_response(
+                    peer_id,
+                    response,
+                    &mut self.network_context,
+                );
+            }
+            RPCResponse::BeaconBlockBodies(response) => {
+                self.sync.on_beacon_block_bodies_response(
+                    peer_id,
+                    response,
+                    &mut self.network_context,
+                );
+            }
+            RPCResponse::BeaconChainState(_) => {
+                // We do not implement this endpoint, it is not required and will only likely be
+                // useful for light-client support in later phases.
+                //
+                // Theoretically, we shouldn't reach this code because we should never send a
+                // beacon state RPC request.
+                warn!(self.log, "BeaconChainState RPC call is not supported.");
             }
-            // TODO: Handle all responses
-            _ => {}
-        }
-    }
-
-    /// Handle a HELLO RPC request message.
-    fn handle_hello_request(&mut self, peer_id: PeerId, id: u64, hello_message: HelloMessage) {
-        // send back a HELLO message
-        self.send_hello(peer_id.clone(), id, false);
-        // validate the peer
-        self.validate_hello(peer_id, hello_message);
-    }
-
-    /// Validate a HELLO RPC message.
-    fn validate_hello(&mut self, peer_id: PeerId, message: HelloMessage) {
-        // validate the peer
-        if !self.sync.validate_peer(peer_id.clone(), message) {
-            debug!(
-                self.log,
-                "Peer dropped due to mismatching HELLO messages: {:?}", peer_id
-            );
-            //TODO: block/ban the peer
-        }
-    }
-
-    /* General RPC helper functions */
-
-    /// Generates a new request id for a peer.
-    fn generate_request_id(&mut self, peer_id: &PeerId) -> u64 {
-        // generate a unique id for the peer
-        let id = {
-            let borrowed_id = self.request_ids.entry(peer_id.clone()).or_insert_with(|| 0);
-            let id = borrowed_id.clone();
-            //increment the counter
-            *borrowed_id += 1;
-            id
         };
-        // register RPC request
-        self.requests.insert((peer_id.clone(), id), Instant::now());
-        debug!(
-            self.log,
-            "Hello request registered with peer: {:?}", peer_id
-        );
-        id
     }
 
-    /// Sends a HELLO RPC request or response to a newly connected peer.
-    //TODO: The boolean determines if sending request/respond, will be cleaner in the RPC re-write
-    fn send_hello(&mut self, peer_id: PeerId, id: u64, is_request: bool) {
-        let rpc_event = if is_request {
+    /// Handle RPC messages
+    fn handle_gossip(&mut self, peer_id: PeerId, gossip_message: IncomingGossip) {
+        match gossip_message {
+            IncomingGossip::Block(message) => {
+                self.sync
+                    .on_block_gossip(peer_id, message, &mut self.network_context)
+            }
+            IncomingGossip::Attestation(message) => {
+                self.sync
+                    .on_attestation_gossip(peer_id, message, &mut self.network_context)
+            }
+        }
+    }
+}
+
+pub struct NetworkContext {
+    /// The network channel to relay messages to the Network service.
+    network_send: crossbeam_channel::Sender<NetworkMessage>,
+    /// A mapping of peers and the RPC id we have sent an RPC request to.
+    outstanding_outgoing_request_ids: HashMap<(PeerId, RequestId), Instant>,
+    /// Stores the next `RequestId` we should include on an outgoing `RPCRequest` to a `PeerId`.
+    outgoing_request_ids: HashMap<PeerId, RequestId>,
+    /// The `MessageHandler` logger.
+    log: slog::Logger,
+}
+
+impl NetworkContext {
+    pub fn new(network_send: crossbeam_channel::Sender<NetworkMessage>, log: slog::Logger) -> Self {
+        Self {
+            network_send,
+            outstanding_outgoing_request_ids: HashMap::new(),
+            outgoing_request_ids: HashMap::new(),
+            log,
+        }
+    }
+
+    pub fn disconnect(&mut self, peer_id: PeerId, reason: GoodbyeReason) {
+        self.send_rpc_request(peer_id, RPCRequest::Goodbye(reason))
+        // TODO: disconnect peers.
+    }
+
+    pub fn send_rpc_request(&mut self, peer_id: PeerId, rpc_request: RPCRequest) {
+        let id = self.generate_request_id(&peer_id);
+
+        self.outstanding_outgoing_request_ids
+            .insert((peer_id.clone(), id.clone()), Instant::now());
+
+        self.send_rpc_event(
+            peer_id,
             RPCEvent::Request {
                 id,
-                method_id: RPCMethod::Hello.into(),
-                body: RPCRequest::Hello(self.sync.generate_hello()),
-            }
-        } else {
-            RPCEvent::Response {
-                id,
-                method_id: RPCMethod::Hello.into(),
-                result: RPCResponse::Hello(self.sync.generate_hello()),
-            }
-        };
-
-        // send the hello request to the network
-        trace!(self.log, "Sending HELLO message to peer {:?}", peer_id);
-        self.send_rpc(peer_id, rpc_event);
+                method_id: rpc_request.method_id(),
+                body: rpc_request,
+            },
+        );
     }
 
-    /// Sends an RPC request/response to the network server.
-    fn send_rpc(&self, peer_id: PeerId, rpc_event: RPCEvent) {
+    pub fn send_rpc_response(
+        &mut self,
+        peer_id: PeerId,
+        request_id: RequestId,
+        rpc_response: RPCResponse,
+    ) {
+        self.send_rpc_event(
+            peer_id,
+            RPCEvent::Response {
+                id: request_id,
+                method_id: rpc_response.method_id(),
+                result: rpc_response,
+            },
+        );
+    }
+
+    fn send_rpc_event(&self, peer_id: PeerId, rpc_event: RPCEvent) {
+        self.send(peer_id, OutgoingMessage::RPC(rpc_event))
+    }
+
+    fn send(&self, peer_id: PeerId, outgoing_message: OutgoingMessage) {
         self.network_send
-            .send(NetworkMessage::Send(
-                peer_id,
-                OutgoingMessage::RPC(rpc_event),
-            ))
+            .send(NetworkMessage::Send(peer_id, outgoing_message))
             .unwrap_or_else(|_| {
                 warn!(
                     self.log,
                     "Could not send RPC message to the network service"
                 )
             });
+        //
+    }
+
+    /// Returns the next `RequestId` for sending an `RPCRequest` to the `peer_id`.
+    fn generate_request_id(&mut self, peer_id: &PeerId) -> RequestId {
+        let next_id = self
+            .outgoing_request_ids
+            .entry(peer_id.clone())
+            .and_modify(|id| id.increment())
+            .or_insert_with(|| RequestId::from(1));
+
+        next_id.previous()
     }
 }

beacon_node/network/src/service.rs

@@ -15,8 +15,8 @@ use tokio::runtime::TaskExecutor;
 
 /// Service that handles communication between internal services and the eth2_libp2p network service.
 pub struct Service {
-    //eth2_libp2p_service: Arc<Mutex<LibP2PService>>,
-    eth2_libp2p_exit: oneshot::Sender<()>,
+    //libp2p_service: Arc<Mutex<LibP2PService>>,
+    libp2p_exit: oneshot::Sender<()>,
     network_send: crossbeam_channel::Sender<NetworkMessage>,
     //message_handler: MessageHandler,
     //message_handler_send: Sender<HandlerMessage>,
@@ -40,20 +40,20 @@ impl Service {
             message_handler_log,
         )?;
 
-        // launch eth2_libp2p service
-        let eth2_libp2p_log = log.new(o!("Service" => "Libp2p"));
-        let eth2_libp2p_service = LibP2PService::new(config.clone(), eth2_libp2p_log)?;
+        // launch libp2p service
+        let libp2p_log = log.new(o!("Service" => "Libp2p"));
+        let libp2p_service = LibP2PService::new(config.clone(), libp2p_log)?;
 
-        // TODO: Spawn thread to handle eth2_libp2p messages and pass to message handler thread.
-        let eth2_libp2p_exit = spawn_service(
-            eth2_libp2p_service,
+        // TODO: Spawn thread to handle libp2p messages and pass to message handler thread.
+        let libp2p_exit = spawn_service(
+            libp2p_service,
             network_recv,
             message_handler_send,
             executor,
             log,
         )?;
         let network_service = Service {
-            eth2_libp2p_exit,
+            libp2p_exit,
             network_send: network_send.clone(),
         };
 
@@ -72,7 +72,7 @@ impl Service {
 }
 
 fn spawn_service(
-    eth2_libp2p_service: LibP2PService,
+    libp2p_service: LibP2PService,
     network_recv: crossbeam_channel::Receiver<NetworkMessage>,
     message_handler_send: crossbeam_channel::Sender<HandlerMessage>,
     executor: &TaskExecutor,
@@ -83,7 +83,7 @@ fn spawn_service(
     // spawn on the current executor
     executor.spawn(
         network_service(
-            eth2_libp2p_service,
+            libp2p_service,
             network_recv,
             message_handler_send,
             log.clone(),
@@ -100,7 +100,7 @@ fn spawn_service(
 }
 
 fn network_service(
-    mut eth2_libp2p_service: LibP2PService,
+    mut libp2p_service: LibP2PService,
     network_recv: crossbeam_channel::Receiver<NetworkMessage>,
     message_handler_send: crossbeam_channel::Sender<HandlerMessage>,
     log: slog::Logger,
@@ -108,28 +108,34 @@ fn network_service(
     futures::future::poll_fn(move || -> Result<_, eth2_libp2p::error::Error> {
         // poll the swarm
         loop {
-            match eth2_libp2p_service.poll() {
-                Ok(Async::Ready(Some(Libp2pEvent::RPC(peer_id, rpc_event)))) => {
-                    trace!(
-                        eth2_libp2p_service.log,
-                        "RPC Event: RPC message received: {:?}",
-                        rpc_event
-                    );
-                    message_handler_send
-                        .send(HandlerMessage::RPC(peer_id, rpc_event))
-                        .map_err(|_| "failed to send rpc to handler")?;
-                }
-                Ok(Async::Ready(Some(Libp2pEvent::PeerDialed(peer_id)))) => {
-                    debug!(eth2_libp2p_service.log, "Peer Dialed: {:?}", peer_id);
-                    message_handler_send
-                        .send(HandlerMessage::PeerDialed(peer_id))
-                        .map_err(|_| "failed to send rpc to handler")?;
-                }
-                Ok(Async::Ready(Some(Libp2pEvent::Message(m)))) => debug!(
-                    eth2_libp2p_service.log,
-                    "Network Service: Message received: {}", m
-                ),
-                _ => break,
+            match libp2p_service.poll() {
+                Ok(Async::Ready(Some(event))) => match event {
+                    Libp2pEvent::RPC(peer_id, rpc_event) => {
+                        trace!(log, "RPC Event: RPC message received: {:?}", rpc_event);
+                        message_handler_send
+                            .send(HandlerMessage::RPC(peer_id, rpc_event))
+                            .map_err(|_| "failed to send rpc to handler")?;
+                    }
+                    Libp2pEvent::PeerDialed(peer_id) => {
+                        debug!(log, "Peer Dialed: {:?}", peer_id);
+                        message_handler_send
+                            .send(HandlerMessage::PeerDialed(peer_id))
+                            .map_err(|_| "failed to send rpc to handler")?;
+                    }
+                    Libp2pEvent::Identified(peer_id, info) => {
+                        debug!(
+                            log,
+                            "We have identified peer: {:?} with {:?}", peer_id, info
+                        );
+                    }
+                    Libp2pEvent::Message(m) => debug!(
+                        libp2p_service.log,
+                        "Network Service: Message received: {}", m
+                    ),
+                },
+                Ok(Async::Ready(None)) => unreachable!("Stream never ends"),
+                Ok(Async::NotReady) => break,
+                Err(_) => break,
             }
         }
         // poll the network channel
@@ -143,7 +149,7 @@ fn network_service(
                             trace!(log, "Sending RPC Event: {:?}", rpc_event);
                             //TODO: Make swarm private
                             //TODO: Implement correct peer id topic message handling
-                            eth2_libp2p_service.swarm.send_rpc(peer_id, rpc_event);
+                            libp2p_service.swarm.send_rpc(peer_id, rpc_event);
                         }
                         OutgoingMessage::NotifierTest => {
                             debug!(log, "Received message from notifier");
@@ -165,7 +171,7 @@ fn network_service(
 /// Types of messages that the network service can receive.
 #[derive(Debug, Clone)]
 pub enum NetworkMessage {
-    /// Send a message to eth2_libp2p service.
+    /// Send a message to libp2p service.
     //TODO: Define typing for messages across the wire
     Send(PeerId, OutgoingMessage),
 }

beacon_node/network/src/sync/import_queue.rs

@@ -0,0 +1,232 @@
+use crate::beacon_chain::BeaconChain;
+use eth2_libp2p::rpc::methods::*;
+use eth2_libp2p::PeerId;
+use slog::{debug, error};
+use ssz::TreeHash;
+use std::sync::Arc;
+use std::time::{Duration, Instant};
+use types::{BeaconBlock, BeaconBlockBody, BeaconBlockHeader, Hash256};
+
+/// Provides a queue for fully and partially built `BeaconBlock`s.
+///
+/// The queue is fundamentally a `Vec<PartialBeaconBlock>` where no two items have the same
+/// `item.block_root`. This struct it backed by a `Vec` not a `HashMap` for the following two
+/// reasons:
+///
+/// - When we receive a `BeaconBlockBody`, the only way we can find it's matching
+/// `BeaconBlockHeader` is to find a header such that `header.beacon_block_body ==
+/// hash_tree_root(body)`. Therefore, if we used a `HashMap` we would need to use the root of
+/// `BeaconBlockBody` as the key.
+/// - It is possible for multiple distinct blocks to have identical `BeaconBlockBodies`. Therefore
+/// we cannot use a `HashMap` keyed by the root of `BeaconBlockBody`.
+pub struct ImportQueue {
+    pub chain: Arc<BeaconChain>,
+    /// Partially imported blocks, keyed by the root of `BeaconBlockBody`.
+    pub partials: Vec<PartialBeaconBlock>,
+    /// Time before a queue entry is considered state.
+    pub stale_time: Duration,
+    /// Logging
+    log: slog::Logger,
+}
+
+impl ImportQueue {
+    /// Return a new, empty queue.
+    pub fn new(chain: Arc<BeaconChain>, stale_time: Duration, log: slog::Logger) -> Self {
+        Self {
+            chain,
+            partials: vec![],
+            stale_time,
+            log,
+        }
+    }
+
+    /// Completes all possible partials into `BeaconBlock` and returns them, sorted by increasing
+    /// slot number.  Does not delete the partials from the queue, this must be done manually.
+    ///
+    /// Returns `(queue_index, block, sender)`:
+    ///
+    /// - `block_root`: may be used to remove the entry if it is successfully processed.
+    /// - `block`: the completed block.
+    /// - `sender`: the `PeerId` the provided the `BeaconBlockBody` which completed the partial.
+    pub fn complete_blocks(&self) -> Vec<(Hash256, BeaconBlock, PeerId)> {
+        let mut complete: Vec<(Hash256, BeaconBlock, PeerId)> = self
+            .partials
+            .iter()
+            .filter_map(|partial| partial.clone().complete())
+            .collect();
+
+        // Sort the completable partials to be in ascending slot order.
+        complete.sort_unstable_by(|a, b| a.1.slot.partial_cmp(&b.1.slot).unwrap());
+
+        complete
+    }
+
+    /// Removes the first `PartialBeaconBlock` with a matching `block_root`, returning the partial
+    /// if it exists.
+    pub fn remove(&mut self, block_root: Hash256) -> Option<PartialBeaconBlock> {
+        let position = self
+            .partials
+            .iter()
+            .position(|p| p.block_root == block_root)?;
+        Some(self.partials.remove(position))
+    }
+
+    /// Flushes all stale entries from the queue.
+    ///
+    /// An entry is stale if it has as a `inserted` time that is more than `self.stale_time` in the
+    /// past.
+    pub fn remove_stale(&mut self) {
+        let stale_indices: Vec<usize> = self
+            .partials
+            .iter()
+            .enumerate()
+            .filter_map(|(i, partial)| {
+                if partial.inserted + self.stale_time <= Instant::now() {
+                    Some(i)
+                } else {
+                    None
+                }
+            })
+            .collect();
+
+        if !stale_indices.is_empty() {
+            debug!(
+                self.log,
+                "ImportQueue removing stale entries";
+                "stale_items" => stale_indices.len(),
+                "stale_time_seconds" => self.stale_time.as_secs()
+            );
+        }
+
+        stale_indices.iter().for_each(|&i| {
+            self.partials.remove(i);
+        });
+    }
+
+    /// Returns `true` if `self.chain` has not yet processed this block.
+    pub fn is_new_block(&self, block_root: &Hash256) -> bool {
+        self.chain
+            .is_new_block_root(&block_root)
+            .unwrap_or_else(|_| {
+                error!(self.log, "Unable to determine if block is new.");
+                true
+            })
+    }
+
+    /// Returns the index of the first new root in the list of block roots.
+    pub fn first_new_root(&mut self, roots: &[BlockRootSlot]) -> Option<usize> {
+        roots
+            .iter()
+            .position(|brs| self.is_new_block(&brs.block_root))
+    }
+
+    /// Adds the `headers` to the `partials` queue. Returns a list of `Hash256` block roots for
+    /// which we should use to request `BeaconBlockBodies`.
+    ///
+    /// If a `header` is not in the queue and has not been processed by the chain it is added to
+    /// the queue and it's block root is included in the output.
+    ///
+    /// If a `header` is already in the queue, but not yet processed by the chain the block root is
+    /// included in the output and the `inserted` time for the partial record is set to
+    /// `Instant::now()`. Updating the `inserted` time stops the partial from becoming stale.
+    ///
+    /// Presently the queue enforces that a `BeaconBlockHeader` _must_ be received before its
+    /// `BeaconBlockBody`. This is not a natural requirement and we could enhance the queue to lift
+    /// this restraint.
+    pub fn enqueue_headers(
+        &mut self,
+        headers: Vec<BeaconBlockHeader>,
+        sender: PeerId,
+    ) -> Vec<Hash256> {
+        let mut required_bodies: Vec<Hash256> = vec![];
+
+        for header in headers {
+            let block_root = Hash256::from_slice(&header.hash_tree_root()[..]);
+
+            if self.is_new_block(&block_root) {
+                self.insert_header(block_root, header, sender.clone());
+                required_bodies.push(block_root)
+            }
+        }
+
+        required_bodies
+    }
+
+    /// If there is a matching `header` for this `body`, adds it to the queue.
+    ///
+    /// If there is no `header` for the `body`, the body is simply discarded.
+    pub fn enqueue_bodies(&mut self, bodies: Vec<BeaconBlockBody>, sender: PeerId) {
+        for body in bodies {
+            self.insert_body(body, sender.clone());
+        }
+    }
+
+    /// Inserts a header to the queue.
+    ///
+    /// If the header already exists, the `inserted` time is set to `now` and not other
+    /// modifications are made.
+    fn insert_header(&mut self, block_root: Hash256, header: BeaconBlockHeader, sender: PeerId) {
+        if let Some(i) = self
+            .partials
+            .iter()
+            .position(|p| p.block_root == block_root)
+        {
+            self.partials[i].inserted = Instant::now();
+        } else {
+            self.partials.push(PartialBeaconBlock {
+                block_root,
+                header,
+                body: None,
+                inserted: Instant::now(),
+                sender,
+            })
+        }
+    }
+
+    /// Updates an existing partial with the `body`.
+    ///
+    /// If there is no header for the `body`, the body is simply discarded.
+    ///
+    /// If the body already existed, the `inserted` time is set to `now`.
+    fn insert_body(&mut self, body: BeaconBlockBody, sender: PeerId) {
+        let body_root = Hash256::from_slice(&body.hash_tree_root()[..]);
+
+        self.partials.iter_mut().for_each(|mut p| {
+            if body_root == p.header.block_body_root {
+                p.inserted = Instant::now();
+
+                if p.body.is_none() {
+                    p.body = Some(body.clone());
+                    p.sender = sender.clone();
+                }
+            }
+        });
+    }
+}
+
+/// Individual components of a `BeaconBlock`, potentially all that are required to form a full
+/// `BeaconBlock`.
+#[derive(Clone, Debug)]
+pub struct PartialBeaconBlock {
+    /// `BeaconBlock` root.
+    pub block_root: Hash256,
+    pub header: BeaconBlockHeader,
+    pub body: Option<BeaconBlockBody>,
+    /// The instant at which this record was created or last meaningfully modified. Used to
+    /// determine if an entry is stale and should be removed.
+    pub inserted: Instant,
+    /// The `PeerId` that last meaningfully contributed to this item.
+    pub sender: PeerId,
+}
+
+impl PartialBeaconBlock {
+    /// Consumes `self` and returns a full built `BeaconBlock`, it's root and the `sender`
+    /// `PeerId`, if enough information exists to complete the block. Otherwise, returns `None`.
+    pub fn complete(self) -> Option<(Hash256, BeaconBlock, PeerId)> {
+        Some((
+            self.block_root,
+            self.header.into_block(self.body?),
+            self.sender,
+        ))
+    }
+}

beacon_node/network/src/sync/mod.rs

@@ -1,3 +1,4 @@
+mod import_queue;
 /// Syncing for lighthouse.
 ///
 /// Stores the various syncing methods for the beacon chain.

beacon_node/network/src/sync/simple_sync.rs

@@ -1,112 +1,686 @@
+use super::import_queue::ImportQueue;
 use crate::beacon_chain::BeaconChain;
-use eth2_libp2p::rpc::HelloMessage;
+use crate::message_handler::NetworkContext;
+use eth2_libp2p::behaviour::{AttestationGossip, BlockGossip};
+use eth2_libp2p::rpc::methods::*;
+use eth2_libp2p::rpc::{RPCRequest, RPCResponse, RequestId};
 use eth2_libp2p::PeerId;
-use slog::{debug, o};
+use slog::{debug, error, info, o, warn};
 use std::collections::HashMap;
 use std::sync::Arc;
+use std::time::Duration;
 use types::{Epoch, Hash256, Slot};
 
 /// The number of slots that we can import blocks ahead of us, before going into full Sync mode.
 const SLOT_IMPORT_TOLERANCE: u64 = 100;
 
+/// The amount of seconds a block (or partial block) may exist in the import queue.
+const QUEUE_STALE_SECS: u64 = 60;
+
 /// Keeps track of syncing information for known connected peers.
+#[derive(Clone, Copy, Debug)]
 pub struct PeerSyncInfo {
+    network_id: u8,
     latest_finalized_root: Hash256,
     latest_finalized_epoch: Epoch,
     best_root: Hash256,
     best_slot: Slot,
 }
 
+impl PeerSyncInfo {
+    /// Returns `true` if the has a different network ID to `other`.
+    fn has_different_network_id_to(&self, other: Self) -> bool {
+        self.network_id != other.network_id
+    }
+
+    /// Returns `true` if the peer has a higher finalized epoch than `other`.
+    fn has_higher_finalized_epoch_than(&self, other: Self) -> bool {
+        self.latest_finalized_epoch > other.latest_finalized_epoch
+    }
+
+    /// Returns `true` if the peer has a higher best slot than `other`.
+    fn has_higher_best_slot_than(&self, other: Self) -> bool {
+        self.best_slot > other.best_slot
+    }
+}
+
+/// The status of a peers view on the chain, relative to some other view of the chain (presumably
+/// our view).
+#[derive(PartialEq, Clone, Copy, Debug)]
+pub enum PeerStatus {
+    /// The peer is on a completely different chain.
+    DifferentNetworkId,
+    /// The peer lists a finalized epoch for which we have a different root.
+    FinalizedEpochNotInChain,
+    /// The peer has a higher finalized epoch.
+    HigherFinalizedEpoch,
+    /// The peer has a higher best slot.
+    HigherBestSlot,
+    /// The peer has the same or lesser view of the chain. We have nothing to request of them.
+    NotInteresting,
+}
+
+impl PeerStatus {
+    pub fn should_handshake(&self) -> bool {
+        match self {
+            PeerStatus::DifferentNetworkId => false,
+            PeerStatus::FinalizedEpochNotInChain => false,
+            PeerStatus::HigherFinalizedEpoch => true,
+            PeerStatus::HigherBestSlot => true,
+            PeerStatus::NotInteresting => true,
+        }
+    }
+}
+
+impl From<HelloMessage> for PeerSyncInfo {
+    fn from(hello: HelloMessage) -> PeerSyncInfo {
+        PeerSyncInfo {
+            network_id: hello.network_id,
+            latest_finalized_root: hello.latest_finalized_root,
+            latest_finalized_epoch: hello.latest_finalized_epoch,
+            best_root: hello.best_root,
+            best_slot: hello.best_slot,
+        }
+    }
+}
+
+impl From<&Arc<BeaconChain>> for PeerSyncInfo {
+    fn from(chain: &Arc<BeaconChain>) -> PeerSyncInfo {
+        Self::from(chain.hello_message())
+    }
+}
+
 /// The current syncing state.
 #[derive(PartialEq)]
 pub enum SyncState {
     Idle,
     Downloading,
-    Stopped,
+    _Stopped,
 }
 
 /// Simple Syncing protocol.
-//TODO: Decide for HELLO messages whether its better to keep current in RAM or build on the fly
-//when asked.
 pub struct SimpleSync {
     /// A reference to the underlying beacon chain.
     chain: Arc<BeaconChain>,
     /// A mapping of Peers to their respective PeerSyncInfo.
     known_peers: HashMap<PeerId, PeerSyncInfo>,
+    /// A queue to allow importing of blocks
+    import_queue: ImportQueue,
     /// The current state of the syncing protocol.
     state: SyncState,
-    /// The network id, for quick HELLO RPC message lookup.
-    network_id: u8,
-    /// The latest epoch of the syncing chain.
-    latest_finalized_epoch: Epoch,
-    /// The latest block of the syncing chain.
-    latest_slot: Slot,
     /// Sync logger.
     log: slog::Logger,
 }
 
 impl SimpleSync {
+    /// Instantiate a `SimpleSync` instance, with no peers and an empty queue.
     pub fn new(beacon_chain: Arc<BeaconChain>, log: &slog::Logger) -> Self {
-        let state = beacon_chain.get_state();
         let sync_logger = log.new(o!("Service"=> "Sync"));
+
+        let queue_item_stale_time = Duration::from_secs(QUEUE_STALE_SECS);
+
+        let import_queue =
+            ImportQueue::new(beacon_chain.clone(), queue_item_stale_time, log.clone());
         SimpleSync {
             chain: beacon_chain.clone(),
             known_peers: HashMap::new(),
+            import_queue,
             state: SyncState::Idle,
-            network_id: beacon_chain.get_spec().network_id,
-            latest_finalized_epoch: state.finalized_epoch,
-            latest_slot: state.slot - 1, //TODO: Build latest block function into Beacon chain and correct this
             log: sync_logger,
         }
     }
 
-    /// Generates our current state in the form of a HELLO RPC message.
-    pub fn generate_hello(&self) -> HelloMessage {
-        let state = &self.chain.get_state();
-        //TODO: Paul to verify the logic of these fields.
-        HelloMessage {
-            network_id: self.network_id,
-            latest_finalized_root: state.finalized_root,
-            latest_finalized_epoch: state.finalized_epoch,
-            best_root: Hash256::zero(), //TODO: build correct value as a beacon chain function
-            best_slot: state.slot - 1,
+    /// Handle a `Goodbye` message from a peer.
+    ///
+    /// Removes the peer from `known_peers`.
+    pub fn on_goodbye(&mut self, peer_id: PeerId, reason: GoodbyeReason) {
+        info!(
+            self.log, "PeerGoodbye";
+            "peer" => format!("{:?}", peer_id),
+            "reason" => format!("{:?}", reason),
+        );
+
+        self.known_peers.remove(&peer_id);
+    }
+
+    /// Handle the connection of a new peer.
+    ///
+    /// Sends a `Hello` message to the peer.
+    pub fn on_connect(&self, peer_id: PeerId, network: &mut NetworkContext) {
+        info!(self.log, "PeerConnect"; "peer" => format!("{:?}", peer_id));
+
+        network.send_rpc_request(peer_id, RPCRequest::Hello(self.chain.hello_message()));
+    }
+
+    /// Handle a `Hello` request.
+    ///
+    /// Processes the `HelloMessage` from the remote peer and sends back our `Hello`.
+    pub fn on_hello_request(
+        &mut self,
+        peer_id: PeerId,
+        request_id: RequestId,
+        hello: HelloMessage,
+        network: &mut NetworkContext,
+    ) {
+        debug!(self.log, "HelloRequest"; "peer" => format!("{:?}", peer_id));
+
+        // Say hello back.
+        network.send_rpc_response(
+            peer_id.clone(),
+            request_id,
+            RPCResponse::Hello(self.chain.hello_message()),
+        );
+
+        self.process_hello(peer_id, hello, network);
+    }
+
+    /// Process a `Hello` response from a peer.
+    pub fn on_hello_response(
+        &mut self,
+        peer_id: PeerId,
+        hello: HelloMessage,
+        network: &mut NetworkContext,
+    ) {
+        debug!(self.log, "HelloResponse"; "peer" => format!("{:?}", peer_id));
+
+        // Process the hello message, without sending back another hello.
+        self.process_hello(peer_id, hello, network);
+    }
+
+    /// Returns a `PeerStatus` for some peer.
+    fn peer_status(&self, peer: PeerSyncInfo) -> PeerStatus {
+        let local = PeerSyncInfo::from(&self.chain);
+
+        if peer.has_different_network_id_to(local) {
+            return PeerStatus::DifferentNetworkId;
+        }
+
+        if local.has_higher_finalized_epoch_than(peer) {
+            let peer_finalized_slot = peer
+                .latest_finalized_epoch
+                .start_slot(self.chain.get_spec().slots_per_epoch);
+
+            let local_roots = self.chain.get_block_roots(peer_finalized_slot, 1, 0);
+
+            if let Ok(local_roots) = local_roots {
+                if let Some(local_root) = local_roots.get(0) {
+                    if *local_root != peer.latest_finalized_root {
+                        return PeerStatus::FinalizedEpochNotInChain;
+                    }
+                } else {
+                    error!(
+                        self.log,
+                        "Cannot get root for peer finalized slot.";
+                        "error" => "empty roots"
+                    );
+                }
+            } else {
+                error!(
+                    self.log,
+                    "Cannot get root for peer finalized slot.";
+                    "error" => format!("{:?}", local_roots)
+                );
+            }
+        }
+
+        if peer.has_higher_finalized_epoch_than(local) {
+            PeerStatus::HigherFinalizedEpoch
+        } else if peer.has_higher_best_slot_than(local) {
+            PeerStatus::HigherBestSlot
+        } else {
+            PeerStatus::NotInteresting
         }
     }
 
-    pub fn validate_peer(&mut self, peer_id: PeerId, hello_message: HelloMessage) -> bool {
-        // network id must match
-        if hello_message.network_id != self.network_id {
-            return false;
-        }
-        // compare latest epoch and finalized root to see if they exist in our chain
-        if hello_message.latest_finalized_epoch <= self.latest_finalized_epoch {
-            // ensure their finalized root is in our chain
-            // TODO: Get the finalized root at hello_message.latest_epoch and ensure they match
-            //if (hello_message.latest_finalized_root == self.chain.get_state() {
-            //    return false;
-            //    }
+    /// Process a `Hello` message, requesting new blocks if appropriate.
+    ///
+    /// Disconnects the peer if required.
+    fn process_hello(
+        &mut self,
+        peer_id: PeerId,
+        hello: HelloMessage,
+        network: &mut NetworkContext,
+    ) {
+        let spec = self.chain.get_spec();
+
+        let remote = PeerSyncInfo::from(hello);
+        let local = PeerSyncInfo::from(&self.chain);
+        let remote_status = self.peer_status(remote);
+
+        if remote_status.should_handshake() {
+            info!(self.log, "HandshakeSuccess"; "peer" => format!("{:?}", peer_id));
+            self.known_peers.insert(peer_id.clone(), remote);
+        } else {
+            info!(
+                self.log, "HandshakeFailure";
+                "peer" => format!("{:?}", peer_id),
+                "reason" => "network_id"
+            );
+            network.disconnect(peer_id.clone(), GoodbyeReason::IrreleventNetwork);
         }
 
-        // the client is valid, add it to our list of known_peers and request sync if required
-        // update peer list if peer already exists
-        let peer_info = PeerSyncInfo {
-            latest_finalized_root: hello_message.latest_finalized_root,
-            latest_finalized_epoch: hello_message.latest_finalized_epoch,
-            best_root: hello_message.best_root,
-            best_slot: hello_message.best_slot,
+        // If required, send additional requests.
+        match remote_status {
+            PeerStatus::HigherFinalizedEpoch => {
+                let start_slot = remote
+                    .latest_finalized_epoch
+                    .start_slot(spec.slots_per_epoch);
+                let required_slots = start_slot - local.best_slot;
+
+                self.request_block_roots(
+                    peer_id,
+                    BeaconBlockRootsRequest {
+                        start_slot,
+                        count: required_slots.into(),
+                    },
+                    network,
+                );
+            }
+            PeerStatus::HigherBestSlot => {
+                let required_slots = remote.best_slot - local.best_slot;
+
+                self.request_block_roots(
+                    peer_id,
+                    BeaconBlockRootsRequest {
+                        start_slot: local.best_slot + 1,
+                        count: required_slots.into(),
+                    },
+                    network,
+                );
+            }
+            PeerStatus::FinalizedEpochNotInChain => {}
+            PeerStatus::DifferentNetworkId => {}
+            PeerStatus::NotInteresting => {}
+        }
+    }
+
+    /// Handle a `BeaconBlockRoots` request from the peer.
+    pub fn on_beacon_block_roots_request(
+        &mut self,
+        peer_id: PeerId,
+        request_id: RequestId,
+        req: BeaconBlockRootsRequest,
+        network: &mut NetworkContext,
+    ) {
+        debug!(
+            self.log,
+            "BlockRootsRequest";
+            "peer" => format!("{:?}", peer_id),
+            "count" => req.count,
+        );
+
+        let roots = match self
+            .chain
+            .get_block_roots(req.start_slot, req.count as usize, 0)
+        {
+            Ok(roots) => roots,
+            Err(e) => {
+                // TODO: return RPC error.
+                warn!(
+                    self.log,
+                    "RPCRequest"; "peer" => format!("{:?}", peer_id),
+                    "req" => "BeaconBlockRoots",
+                    "error" => format!("{:?}", e)
+                );
+                return;
+            }
         };
 
-        debug!(self.log, "Handshake successful. Peer: {:?}", peer_id);
-        self.known_peers.insert(peer_id, peer_info);
+        let roots = roots
+            .iter()
+            .enumerate()
+            .map(|(i, &block_root)| BlockRootSlot {
+                slot: req.start_slot + Slot::from(i),
+                block_root,
+            })
+            .collect();
 
-        // set state to sync
-        if self.state == SyncState::Idle
-            && hello_message.best_slot > self.latest_slot + SLOT_IMPORT_TOLERANCE
-        {
-            self.state = SyncState::Downloading;
-            //TODO: Start requesting blocks from known peers. Ideally in batches
+        network.send_rpc_response(
+            peer_id,
+            request_id,
+            RPCResponse::BeaconBlockRoots(BeaconBlockRootsResponse { roots }),
+        )
+    }
+
+    /// Handle a `BeaconBlockRoots` response from the peer.
+    pub fn on_beacon_block_roots_response(
+        &mut self,
+        peer_id: PeerId,
+        res: BeaconBlockRootsResponse,
+        network: &mut NetworkContext,
+    ) {
+        debug!(
+            self.log,
+            "BlockRootsResponse";
+            "peer" => format!("{:?}", peer_id),
+            "count" => res.roots.len(),
+        );
+
+        if res.roots.is_empty() {
+            warn!(
+                self.log,
+                "Peer returned empty block roots response. PeerId: {:?}", peer_id
+            );
+            return;
         }
 
-        true
+        let new_root_index = self.import_queue.first_new_root(&res.roots);
+
+        // If a new block root is found, request it and all the headers following it.
+        //
+        // We make an assumption here that if we don't know a block then we don't know of all
+        // it's parents. This might not be the case if syncing becomes more sophisticated.
+        if let Some(i) = new_root_index {
+            let new = &res.roots[i];
+
+            self.request_block_headers(
+                peer_id,
+                BeaconBlockHeadersRequest {
+                    start_root: new.block_root,
+                    start_slot: new.slot,
+                    max_headers: (res.roots.len() - i) as u64,
+                    skip_slots: 0,
+                },
+                network,
+            )
+        }
+    }
+
+    /// Handle a `BeaconBlockHeaders` request from the peer.
+    pub fn on_beacon_block_headers_request(
+        &mut self,
+        peer_id: PeerId,
+        request_id: RequestId,
+        req: BeaconBlockHeadersRequest,
+        network: &mut NetworkContext,
+    ) {
+        debug!(
+            self.log,
+            "BlockHeadersRequest";
+            "peer" => format!("{:?}", peer_id),
+            "count" => req.max_headers,
+        );
+
+        let headers = match self.chain.get_block_headers(
+            req.start_slot,
+            req.max_headers as usize,
+            req.skip_slots as usize,
+        ) {
+            Ok(headers) => headers,
+            Err(e) => {
+                // TODO: return RPC error.
+                warn!(
+                    self.log,
+                    "RPCRequest"; "peer" => format!("{:?}", peer_id),
+                    "req" => "BeaconBlockHeaders",
+                    "error" => format!("{:?}", e)
+                );
+                return;
+            }
+        };
+
+        network.send_rpc_response(
+            peer_id,
+            request_id,
+            RPCResponse::BeaconBlockHeaders(BeaconBlockHeadersResponse { headers }),
+        )
+    }
+
+    /// Handle a `BeaconBlockHeaders` response from the peer.
+    pub fn on_beacon_block_headers_response(
+        &mut self,
+        peer_id: PeerId,
+        res: BeaconBlockHeadersResponse,
+        network: &mut NetworkContext,
+    ) {
+        debug!(
+            self.log,
+            "BlockHeadersResponse";
+            "peer" => format!("{:?}", peer_id),
+            "count" => res.headers.len(),
+        );
+
+        if res.headers.is_empty() {
+            warn!(
+                self.log,
+                "Peer returned empty block headers response. PeerId: {:?}", peer_id
+            );
+            return;
+        }
+
+        // Enqueue the headers, obtaining a list of the roots of the headers which were newly added
+        // to the queue.
+        let block_roots = self
+            .import_queue
+            .enqueue_headers(res.headers, peer_id.clone());
+
+        self.request_block_bodies(peer_id, BeaconBlockBodiesRequest { block_roots }, network);
+    }
+
+    /// Handle a `BeaconBlockBodies` request from the peer.
+    pub fn on_beacon_block_bodies_request(
+        &mut self,
+        peer_id: PeerId,
+        request_id: RequestId,
+        req: BeaconBlockBodiesRequest,
+        network: &mut NetworkContext,
+    ) {
+        debug!(
+            self.log,
+            "BlockBodiesRequest";
+            "peer" => format!("{:?}", peer_id),
+            "count" => req.block_roots.len(),
+        );
+
+        let block_bodies = match self.chain.get_block_bodies(&req.block_roots) {
+            Ok(bodies) => bodies,
+            Err(e) => {
+                // TODO: return RPC error.
+                warn!(
+                    self.log,
+                    "RPCRequest"; "peer" => format!("{:?}", peer_id),
+                    "req" => "BeaconBlockBodies",
+                    "error" => format!("{:?}", e)
+                );
+                return;
+            }
+        };
+
+        network.send_rpc_response(
+            peer_id,
+            request_id,
+            RPCResponse::BeaconBlockBodies(BeaconBlockBodiesResponse { block_bodies }),
+        )
+    }
+
+    /// Handle a `BeaconBlockBodies` response from the peer.
+    pub fn on_beacon_block_bodies_response(
+        &mut self,
+        peer_id: PeerId,
+        res: BeaconBlockBodiesResponse,
+        network: &mut NetworkContext,
+    ) {
+        debug!(
+            self.log,
+            "BlockBodiesResponse";
+            "peer" => format!("{:?}", peer_id),
+            "count" => res.block_bodies.len(),
+        );
+
+        self.import_queue
+            .enqueue_bodies(res.block_bodies, peer_id.clone());
+
+        // Clear out old entries
+        self.import_queue.remove_stale();
+
+        // Import blocks, if possible.
+        self.process_import_queue(network);
+    }
+
+    /// Process a gossip message declaring a new block.
+    pub fn on_block_gossip(
+        &mut self,
+        peer_id: PeerId,
+        msg: BlockGossip,
+        network: &mut NetworkContext,
+    ) {
+        debug!(
+            self.log,
+            "BlockGossip";
+            "peer" => format!("{:?}", peer_id),
+        );
+        // TODO: filter out messages that a prior to the finalized slot.
+        //
+        // TODO: if the block is a few more slots ahead, try to get all block roots from then until
+        // now.
+        //
+        // Note: only requests the new block -- will fail if we don't have its parents.
+        if self.import_queue.is_new_block(&msg.root.block_root) {
+            self.request_block_headers(
+                peer_id,
+                BeaconBlockHeadersRequest {
+                    start_root: msg.root.block_root,
+                    start_slot: msg.root.slot,
+                    max_headers: 1,
+                    skip_slots: 0,
+                },
+                network,
+            )
+        }
+    }
+
+    /// Process a gossip message declaring a new attestation.
+    ///
+    /// Not currently implemented.
+    pub fn on_attestation_gossip(
+        &mut self,
+        peer_id: PeerId,
+        msg: AttestationGossip,
+        _network: &mut NetworkContext,
+    ) {
+        debug!(
+            self.log,
+            "AttestationGossip";
+            "peer" => format!("{:?}", peer_id),
+        );
+
+        // Awaiting a proper operations pool before we can import attestations.
+        //
+        // https://github.com/sigp/lighthouse/issues/281
+        match self.chain.process_attestation(msg.attestation) {
+            Ok(_) => panic!("Impossible, method not implemented."),
+            Err(_) => error!(self.log, "Attestation processing not implemented!"),
+        }
+    }
+
+    /// Iterate through the `import_queue` and process any complete blocks.
+    ///
+    /// If a block is successfully processed it is removed from the queue, otherwise it remains in
+    /// the queue.
+    pub fn process_import_queue(&mut self, network: &mut NetworkContext) {
+        let mut successful = 0;
+        let mut invalid = 0;
+        let mut errored = 0;
+
+        // Loop through all of the complete blocks in the queue.
+        for (block_root, block, sender) in self.import_queue.complete_blocks() {
+            match self.chain.process_block(block) {
+                Ok(outcome) => {
+                    if outcome.is_invalid() {
+                        invalid += 1;
+                        warn!(
+                            self.log,
+                            "InvalidBlock";
+                            "sender_peer_id" => format!("{:?}", sender),
+                            "reason" => format!("{:?}", outcome),
+                        );
+                        network.disconnect(sender, GoodbyeReason::Fault);
+                    }
+
+                    // If this results to true, the item will be removed from the queue.
+                    if outcome.sucessfully_processed() {
+                        successful += 1;
+                        self.import_queue.remove(block_root);
+                    }
+                }
+                Err(e) => {
+                    errored += 1;
+                    error!(self.log, "BlockProcessingError"; "error" => format!("{:?}", e));
+                }
+            }
+        }
+
+        if successful > 0 {
+            info!(self.log, "Imported {} blocks", successful)
+        }
+        if invalid > 0 {
+            warn!(self.log, "Rejected {} invalid blocks", invalid)
+        }
+        if errored > 0 {
+            warn!(self.log, "Failed to process {} blocks", errored)
+        }
+    }
+
+    /// Request some `BeaconBlockRoots` from the remote peer.
+    fn request_block_roots(
+        &mut self,
+        peer_id: PeerId,
+        req: BeaconBlockRootsRequest,
+        network: &mut NetworkContext,
+    ) {
+        // Potentially set state to sync.
+        if self.state == SyncState::Idle && req.count > SLOT_IMPORT_TOLERANCE {
+            debug!(self.log, "Entering downloading sync state.");
+            self.state = SyncState::Downloading;
+        }
+
+        debug!(
+            self.log,
+            "RPCRequest(BeaconBlockRoots)";
+            "count" => req.count,
+            "peer" => format!("{:?}", peer_id)
+        );
+
+        // TODO: handle count > max count.
+        network.send_rpc_request(peer_id.clone(), RPCRequest::BeaconBlockRoots(req));
+    }
+
+    /// Request some `BeaconBlockHeaders` from the remote peer.
+    fn request_block_headers(
+        &mut self,
+        peer_id: PeerId,
+        req: BeaconBlockHeadersRequest,
+        network: &mut NetworkContext,
+    ) {
+        debug!(
+            self.log,
+            "RPCRequest(BeaconBlockHeaders)";
+            "max_headers" => req.max_headers,
+            "peer" => format!("{:?}", peer_id)
+        );
+
+        network.send_rpc_request(peer_id.clone(), RPCRequest::BeaconBlockHeaders(req));
+    }
+
+    /// Request some `BeaconBlockBodies` from the remote peer.
+    fn request_block_bodies(
+        &mut self,
+        peer_id: PeerId,
+        req: BeaconBlockBodiesRequest,
+        network: &mut NetworkContext,
+    ) {
+        debug!(
+            self.log,
+            "RPCRequest(BeaconBlockBodies)";
+            "count" => req.block_roots.len(),
+            "peer" => format!("{:?}", peer_id)
+        );
+
+        network.send_rpc_request(peer_id.clone(), RPCRequest::BeaconBlockBodies(req));
+    }
+
+    /// Generates our current state in the form of a HELLO RPC message.
+    pub fn generate_hello(&self) -> HelloMessage {
+        self.chain.hello_message()
     }
 }

beacon_node/network/tests/tests.rs

@@ -0,0 +1,570 @@
+use crossbeam_channel::{unbounded, Receiver, RecvTimeoutError, Sender};
+use eth2_libp2p::rpc::methods::*;
+use eth2_libp2p::rpc::{RPCMethod, RPCRequest, RPCResponse, RequestId};
+use eth2_libp2p::{PeerId, RPCEvent};
+use network::beacon_chain::BeaconChain as NetworkBeaconChain;
+use network::message_handler::{HandlerMessage, MessageHandler};
+use network::service::{NetworkMessage, OutgoingMessage};
+use sloggers::terminal::{Destination, TerminalLoggerBuilder};
+use sloggers::types::Severity;
+use sloggers::Build;
+use std::time::Duration;
+use test_harness::BeaconChainHarness;
+use tokio::runtime::TaskExecutor;
+use types::{test_utils::TestingBeaconStateBuilder, *};
+
+pub struct SyncNode {
+    pub id: usize,
+    sender: Sender<HandlerMessage>,
+    receiver: Receiver<NetworkMessage>,
+    peer_id: PeerId,
+    harness: BeaconChainHarness,
+}
+
+impl SyncNode {
+    fn from_beacon_state_builder(
+        id: usize,
+        executor: &TaskExecutor,
+        state_builder: TestingBeaconStateBuilder,
+        spec: &ChainSpec,
+        logger: slog::Logger,
+    ) -> Self {
+        let harness = BeaconChainHarness::from_beacon_state_builder(state_builder, spec.clone());
+
+        let (network_sender, network_receiver) = unbounded();
+        let message_handler_sender = MessageHandler::spawn(
+            harness.beacon_chain.clone(),
+            network_sender,
+            executor,
+            logger,
+        )
+        .unwrap();
+
+        Self {
+            id,
+            sender: message_handler_sender,
+            receiver: network_receiver,
+            peer_id: PeerId::random(),
+            harness,
+        }
+    }
+
+    fn increment_beacon_chain_slot(&mut self) {
+        self.harness.increment_beacon_chain_slot();
+    }
+
+    fn send(&self, message: HandlerMessage) {
+        self.sender.send(message).unwrap();
+    }
+
+    fn recv(&self) -> Result<NetworkMessage, RecvTimeoutError> {
+        self.receiver.recv_timeout(Duration::from_millis(500))
+    }
+
+    fn hello_message(&self) -> HelloMessage {
+        self.harness.beacon_chain.hello_message()
+    }
+
+    pub fn connect_to(&mut self, node: &SyncNode) {
+        let message = HandlerMessage::PeerDialed(self.peer_id.clone());
+        node.send(message);
+    }
+
+    /// Reads the receive queue from one node and passes the message to the other. Also returns a
+    /// copy of the message.
+    ///
+    /// self -----> node
+    ///        |
+    ///        us
+    ///
+    /// Named after the unix `tee` command.
+    fn tee(&mut self, node: &SyncNode) -> NetworkMessage {
+        let network_message = self.recv().expect("Timeout on tee");
+
+        let handler_message = match network_message.clone() {
+            NetworkMessage::Send(_to_peer_id, OutgoingMessage::RPC(event)) => {
+                HandlerMessage::RPC(self.peer_id.clone(), event)
+            }
+            _ => panic!("tee cannot parse {:?}", network_message),
+        };
+
+        node.send(handler_message);
+
+        network_message
+    }
+
+    fn tee_hello_request(&mut self, node: &SyncNode) -> HelloMessage {
+        let request = self.tee_rpc_request(node);
+
+        match request {
+            RPCRequest::Hello(message) => message,
+            _ => panic!("tee_hello_request got: {:?}", request),
+        }
+    }
+
+    fn tee_hello_response(&mut self, node: &SyncNode) -> HelloMessage {
+        let response = self.tee_rpc_response(node);
+
+        match response {
+            RPCResponse::Hello(message) => message,
+            _ => panic!("tee_hello_response got: {:?}", response),
+        }
+    }
+
+    fn tee_block_root_request(&mut self, node: &SyncNode) -> BeaconBlockRootsRequest {
+        let msg = self.tee_rpc_request(node);
+
+        match msg {
+            RPCRequest::BeaconBlockRoots(data) => data,
+            _ => panic!("tee_block_root_request got: {:?}", msg),
+        }
+    }
+
+    fn tee_block_root_response(&mut self, node: &SyncNode) -> BeaconBlockRootsResponse {
+        let msg = self.tee_rpc_response(node);
+
+        match msg {
+            RPCResponse::BeaconBlockRoots(data) => data,
+            _ => panic!("tee_block_root_response got: {:?}", msg),
+        }
+    }
+
+    fn tee_block_header_request(&mut self, node: &SyncNode) -> BeaconBlockHeadersRequest {
+        let msg = self.tee_rpc_request(node);
+
+        match msg {
+            RPCRequest::BeaconBlockHeaders(data) => data,
+            _ => panic!("tee_block_header_request got: {:?}", msg),
+        }
+    }
+
+    fn tee_block_header_response(&mut self, node: &SyncNode) -> BeaconBlockHeadersResponse {
+        let msg = self.tee_rpc_response(node);
+
+        match msg {
+            RPCResponse::BeaconBlockHeaders(data) => data,
+            _ => panic!("tee_block_header_response got: {:?}", msg),
+        }
+    }
+
+    fn tee_block_body_request(&mut self, node: &SyncNode) -> BeaconBlockBodiesRequest {
+        let msg = self.tee_rpc_request(node);
+
+        match msg {
+            RPCRequest::BeaconBlockBodies(data) => data,
+            _ => panic!("tee_block_body_request got: {:?}", msg),
+        }
+    }
+
+    fn tee_block_body_response(&mut self, node: &SyncNode) -> BeaconBlockBodiesResponse {
+        let msg = self.tee_rpc_response(node);
+
+        match msg {
+            RPCResponse::BeaconBlockBodies(data) => data,
+            _ => panic!("tee_block_body_response got: {:?}", msg),
+        }
+    }
+
+    fn tee_rpc_request(&mut self, node: &SyncNode) -> RPCRequest {
+        let network_message = self.tee(node);
+
+        match network_message {
+            NetworkMessage::Send(
+                _peer_id,
+                OutgoingMessage::RPC(RPCEvent::Request {
+                    id: _,
+                    method_id: _,
+                    body,
+                }),
+            ) => body,
+            _ => panic!("tee_rpc_request failed! got {:?}", network_message),
+        }
+    }
+
+    fn tee_rpc_response(&mut self, node: &SyncNode) -> RPCResponse {
+        let network_message = self.tee(node);
+
+        match network_message {
+            NetworkMessage::Send(
+                _peer_id,
+                OutgoingMessage::RPC(RPCEvent::Response {
+                    id: _,
+                    method_id: _,
+                    result,
+                }),
+            ) => result,
+            _ => panic!("tee_rpc_response failed! got {:?}", network_message),
+        }
+    }
+
+    pub fn get_block_root_request(&self) -> BeaconBlockRootsRequest {
+        let request = self.recv_rpc_request().expect("No block root request");
+
+        match request {
+            RPCRequest::BeaconBlockRoots(request) => request,
+            _ => panic!("Did not get block root request"),
+        }
+    }
+
+    pub fn get_block_headers_request(&self) -> BeaconBlockHeadersRequest {
+        let request = self.recv_rpc_request().expect("No block headers request");
+
+        match request {
+            RPCRequest::BeaconBlockHeaders(request) => request,
+            _ => panic!("Did not get block headers request"),
+        }
+    }
+
+    pub fn get_block_bodies_request(&self) -> BeaconBlockBodiesRequest {
+        let request = self.recv_rpc_request().expect("No block bodies request");
+
+        match request {
+            RPCRequest::BeaconBlockBodies(request) => request,
+            _ => panic!("Did not get block bodies request"),
+        }
+    }
+
+    fn _recv_rpc_response(&self) -> Result<RPCResponse, RecvTimeoutError> {
+        let network_message = self.recv()?;
+        Ok(match network_message {
+            NetworkMessage::Send(
+                _peer_id,
+                OutgoingMessage::RPC(RPCEvent::Response {
+                    id: _,
+                    method_id: _,
+                    result,
+                }),
+            ) => result,
+            _ => panic!("get_rpc_response failed! got {:?}", network_message),
+        })
+    }
+
+    fn recv_rpc_request(&self) -> Result<RPCRequest, RecvTimeoutError> {
+        let network_message = self.recv()?;
+        Ok(match network_message {
+            NetworkMessage::Send(
+                _peer_id,
+                OutgoingMessage::RPC(RPCEvent::Request {
+                    id: _,
+                    method_id: _,
+                    body,
+                }),
+            ) => body,
+            _ => panic!("get_rpc_request failed! got {:?}", network_message),
+        })
+    }
+}
+
+fn get_logger() -> slog::Logger {
+    let mut builder = TerminalLoggerBuilder::new();
+    builder.level(Severity::Debug);
+    builder.destination(Destination::Stderr);
+    builder.build().unwrap()
+}
+
+pub struct SyncMaster {
+    harness: BeaconChainHarness,
+    peer_id: PeerId,
+    response_ids: Vec<RequestId>,
+}
+
+impl SyncMaster {
+    fn from_beacon_state_builder(
+        state_builder: TestingBeaconStateBuilder,
+        node_count: usize,
+        spec: &ChainSpec,
+    ) -> Self {
+        let harness = BeaconChainHarness::from_beacon_state_builder(state_builder, spec.clone());
+        let peer_id = PeerId::random();
+        let response_ids = vec![RequestId::from(0); node_count];
+
+        Self {
+            harness,
+            peer_id,
+            response_ids,
+        }
+    }
+
+    pub fn response_id(&mut self, node: &SyncNode) -> RequestId {
+        let id = self.response_ids[node.id].clone();
+        self.response_ids[node.id].increment();
+        id
+    }
+
+    pub fn do_hello_with(&mut self, node: &SyncNode) {
+        let message = HandlerMessage::PeerDialed(self.peer_id.clone());
+        node.send(message);
+
+        let request = node.recv_rpc_request().expect("No hello response");
+
+        match request {
+            RPCRequest::Hello(_hello) => {
+                let hello = self.harness.beacon_chain.hello_message();
+                let response = self.rpc_response(node, RPCResponse::Hello(hello));
+                node.send(response);
+            }
+            _ => panic!("Got message other than hello from node."),
+        }
+    }
+
+    pub fn respond_to_block_roots_request(
+        &mut self,
+        node: &SyncNode,
+        request: BeaconBlockRootsRequest,
+    ) {
+        let roots = self
+            .harness
+            .beacon_chain
+            .get_block_roots(request.start_slot, request.count as usize, 0)
+            .expect("Beacon chain did not give block roots")
+            .iter()
+            .enumerate()
+            .map(|(i, root)| BlockRootSlot {
+                block_root: *root,
+                slot: Slot::from(i) + request.start_slot,
+            })
+            .collect();
+
+        let response = RPCResponse::BeaconBlockRoots(BeaconBlockRootsResponse { roots });
+        self.send_rpc_response(node, response)
+    }
+
+    pub fn respond_to_block_headers_request(
+        &mut self,
+        node: &SyncNode,
+        request: BeaconBlockHeadersRequest,
+    ) {
+        let roots = self
+            .harness
+            .beacon_chain
+            .get_block_roots(
+                request.start_slot,
+                request.max_headers as usize,
+                request.skip_slots as usize,
+            )
+            .expect("Beacon chain did not give blocks");
+
+        if roots.is_empty() {
+            panic!("Roots was empty when trying to get headers.")
+        }
+
+        assert_eq!(
+            roots[0], request.start_root,
+            "Got the wrong start root when getting headers"
+        );
+
+        let headers: Vec<BeaconBlockHeader> = roots
+            .iter()
+            .map(|root| {
+                let block = self
+                    .harness
+                    .beacon_chain
+                    .get_block(root)
+                    .expect("Failed to load block")
+                    .expect("Block did not exist");
+                block.block_header()
+            })
+            .collect();
+
+        let response = RPCResponse::BeaconBlockHeaders(BeaconBlockHeadersResponse { headers });
+        self.send_rpc_response(node, response)
+    }
+
+    pub fn respond_to_block_bodies_request(
+        &mut self,
+        node: &SyncNode,
+        request: BeaconBlockBodiesRequest,
+    ) {
+        let block_bodies: Vec<BeaconBlockBody> = request
+            .block_roots
+            .iter()
+            .map(|root| {
+                let block = self
+                    .harness
+                    .beacon_chain
+                    .get_block(root)
+                    .expect("Failed to load block")
+                    .expect("Block did not exist");
+                block.body
+            })
+            .collect();
+
+        let response = RPCResponse::BeaconBlockBodies(BeaconBlockBodiesResponse { block_bodies });
+        self.send_rpc_response(node, response)
+    }
+
+    fn send_rpc_response(&mut self, node: &SyncNode, rpc_response: RPCResponse) {
+        node.send(self.rpc_response(node, rpc_response));
+    }
+
+    fn rpc_response(&mut self, node: &SyncNode, rpc_response: RPCResponse) -> HandlerMessage {
+        HandlerMessage::RPC(
+            self.peer_id.clone(),
+            RPCEvent::Response {
+                id: self.response_id(node),
+                method_id: RPCMethod::Hello.into(),
+                result: rpc_response,
+            },
+        )
+    }
+}
+
+fn test_setup(
+    state_builder: TestingBeaconStateBuilder,
+    node_count: usize,
+    spec: &ChainSpec,
+    logger: slog::Logger,
+) -> (tokio::runtime::Runtime, SyncMaster, Vec<SyncNode>) {
+    let runtime = tokio::runtime::Runtime::new().unwrap();
+
+    let mut nodes = Vec::with_capacity(node_count);
+    for id in 0..node_count {
+        let node = SyncNode::from_beacon_state_builder(
+            id,
+            &runtime.executor(),
+            state_builder.clone(),
+            &spec,
+            logger.clone(),
+        );
+
+        nodes.push(node);
+    }
+
+    let master = SyncMaster::from_beacon_state_builder(state_builder, node_count, &spec);
+
+    (runtime, master, nodes)
+}
+
+pub fn build_blocks(blocks: usize, master: &mut SyncMaster, nodes: &mut Vec<SyncNode>) {
+    for _ in 0..blocks {
+        master.harness.advance_chain_with_block();
+        for i in 0..nodes.len() {
+            nodes[i].increment_beacon_chain_slot();
+        }
+    }
+    master.harness.run_fork_choice();
+
+    for i in 0..nodes.len() {
+        nodes[i].harness.run_fork_choice();
+    }
+}
+
+#[test]
+#[ignore]
+fn sync_node_with_master() {
+    let logger = get_logger();
+    let spec = ChainSpec::few_validators();
+    let validator_count = 8;
+    let node_count = 1;
+
+    let state_builder =
+        TestingBeaconStateBuilder::from_default_keypairs_file_if_exists(validator_count, &spec);
+
+    let (runtime, mut master, mut nodes) =
+        test_setup(state_builder, node_count, &spec, logger.clone());
+
+    let original_node_slot = nodes[0].hello_message().best_slot;
+
+    build_blocks(2, &mut master, &mut nodes);
+
+    master.do_hello_with(&nodes[0]);
+
+    let roots_request = nodes[0].get_block_root_request();
+    assert_eq!(roots_request.start_slot, original_node_slot + 1);
+    assert_eq!(roots_request.count, 2);
+
+    master.respond_to_block_roots_request(&nodes[0], roots_request);
+
+    let headers_request = nodes[0].get_block_headers_request();
+    assert_eq!(headers_request.start_slot, original_node_slot + 1);
+    assert_eq!(headers_request.max_headers, 2);
+    assert_eq!(headers_request.skip_slots, 0);
+
+    master.respond_to_block_headers_request(&nodes[0], headers_request);
+
+    let bodies_request = nodes[0].get_block_bodies_request();
+    assert_eq!(bodies_request.block_roots.len(), 2);
+
+    master.respond_to_block_bodies_request(&nodes[0], bodies_request);
+
+    std::thread::sleep(Duration::from_millis(10000));
+    runtime.shutdown_now();
+}
+
+#[test]
+#[ignore]
+fn sync_two_nodes() {
+    let logger = get_logger();
+    let spec = ChainSpec::few_validators();
+    let validator_count = 8;
+    let node_count = 2;
+
+    let state_builder =
+        TestingBeaconStateBuilder::from_default_keypairs_file_if_exists(validator_count, &spec);
+
+    let (runtime, _master, mut nodes) =
+        test_setup(state_builder, node_count, &spec, logger.clone());
+
+    // let original_node_slot = nodes[0].hello_message().best_slot;
+    let mut node_a = nodes.remove(0);
+    let mut node_b = nodes.remove(0);
+
+    let blocks = 2;
+
+    // Node A builds out a longer, better chain.
+    for _ in 0..blocks {
+        // Node A should build a block.
+        node_a.harness.advance_chain_with_block();
+        // Node B should just increment it's slot without a block.
+        node_b.harness.increment_beacon_chain_slot();
+    }
+    node_a.harness.run_fork_choice();
+
+    // A connects to B.
+    node_a.connect_to(&node_b);
+
+    // B says hello to A.
+    node_b.tee_hello_request(&node_a);
+    // A says hello back.
+    node_a.tee_hello_response(&node_b);
+
+    // B requests block roots from A.
+    node_b.tee_block_root_request(&node_a);
+    // A provides block roots to A.
+    node_a.tee_block_root_response(&node_b);
+
+    // B requests block headers from A.
+    node_b.tee_block_header_request(&node_a);
+    // A provides block headers to B.
+    node_a.tee_block_header_response(&node_b);
+
+    // B requests block bodies from A.
+    node_b.tee_block_body_request(&node_a);
+    // A provides block bodies to B.
+    node_a.tee_block_body_response(&node_b);
+
+    std::thread::sleep(Duration::from_secs(10));
+
+    node_b.harness.run_fork_choice();
+
+    let node_a_chain = node_a
+        .harness
+        .beacon_chain
+        .chain_dump()
+        .expect("Can't dump node a chain");
+
+    let node_b_chain = node_b
+        .harness
+        .beacon_chain
+        .chain_dump()
+        .expect("Can't dump node b chain");
+
+    assert_eq!(
+        node_a_chain.len(),
+        node_b_chain.len(),
+        "Chains should be equal length"
+    );
+    assert_eq!(node_a_chain, node_b_chain, "Chains should be identical");
+
+    runtime.shutdown_now();
+}

eth2/state_processing/tests/tests.rs

@@ -15,12 +15,10 @@ pub struct TestDoc {
     pub title: String,
     pub summary: String,
     pub fork: String,
-    pub version: String,
     pub test_cases: Vec<TestCase>,
 }
 
 #[test]
-#[ignore]
 fn yaml() {
     use serde_yaml;
     use std::{fs::File, io::prelude::*, path::PathBuf};

eth2/types/Cargo.toml

@@ -10,6 +10,7 @@ boolean-bitfield = { path = "../utils/boolean-bitfield" }
 dirs = "1.0"
 ethereum-types = "0.5"
 hashing = { path = "../utils/hashing" }
+hex = "0.3"
 honey-badger-split =  { path = "../utils/honey-badger-split" }
 int_to_bytes = { path = "../utils/int_to_bytes" }
 log = "0.4"
@@ -24,7 +25,7 @@ ssz = { path = "../utils/ssz" }
 ssz_derive = { path = "../utils/ssz_derive" }
 swap_or_not_shuffle = { path = "../utils/swap_or_not_shuffle" }
 test_random_derive = { path = "../utils/test_random_derive" }
-libp2p =  { git = "https://github.com/SigP/rust-libp2p", branch = "gossipsub" }
+libp2p =  { git = "https://github.com/SigP/rust-libp2p", rev = "b3c32d9a821ae6cc89079499cc6e8a6bab0bffc3" }
 
 [dev-dependencies]
 env_logger = "0.6.0"

eth2/types/src/beacon_block_header.rs

@@ -37,6 +37,19 @@ impl BeaconBlockHeader {
     pub fn canonical_root(&self) -> Hash256 {
         Hash256::from_slice(&self.hash_tree_root()[..])
     }
+
+    /// Given a `body`, consumes `self` and returns a complete `BeaconBlock`.
+    ///
+    /// Spec v0.5.0
+    pub fn into_block(self, body: BeaconBlockBody) -> BeaconBlock {
+        BeaconBlock {
+            slot: self.slot,
+            previous_block_root: self.previous_block_root,
+            state_root: self.state_root,
+            body,
+            signature: self.signature,
+        }
+    }
 }
 
 #[cfg(test)]

eth2/types/src/chain_spec.rs

@@ -2,6 +2,7 @@ use crate::*;
 use bls::Signature;
 use int_to_bytes::int_to_bytes4;
 use serde_derive::Deserialize;
+use test_utils::u8_from_hex_str;
 
 const GWEI: u64 = 1_000_000_000;
 
@@ -57,6 +58,7 @@ pub struct ChainSpec {
     pub far_future_epoch: Epoch,
     pub zero_hash: Hash256,
     pub empty_signature: Signature,
+    #[serde(deserialize_with = "u8_from_hex_str")]
     pub bls_withdrawal_prefix_byte: u8,
 
     /*

eth2/types/src/fork.rs

@@ -1,4 +1,7 @@
-use crate::{test_utils::TestRandom, ChainSpec, Epoch};
+use crate::{
+    test_utils::{fork_from_hex_str, TestRandom},
+    ChainSpec, Epoch,
+};
 use int_to_bytes::int_to_bytes4;
 use rand::RngCore;
 use serde_derive::{Deserialize, Serialize};
@@ -12,7 +15,9 @@ use test_random_derive::TestRandom;
     Debug, Clone, PartialEq, Default, Serialize, Deserialize, Encode, Decode, TreeHash, TestRandom,
 )]
 pub struct Fork {
+    #[serde(deserialize_with = "fork_from_hex_str")]
     pub previous_version: [u8; 4],
+    #[serde(deserialize_with = "fork_from_hex_str")]
     pub current_version: [u8; 4],
     pub epoch: Epoch,
 }

eth2/types/src/test_utils/mod.rs

@@ -2,6 +2,7 @@
 mod macros;
 mod generate_deterministic_keypairs;
 mod keypairs_file;
+mod serde_utils;
 mod test_random;
 mod testing_attestation_builder;
 mod testing_attestation_data_builder;
@@ -17,6 +18,7 @@ mod testing_voluntary_exit_builder;
 pub use generate_deterministic_keypairs::generate_deterministic_keypairs;
 pub use keypairs_file::KeypairsFile;
 pub use rand::{prng::XorShiftRng, SeedableRng};
+pub use serde_utils::{fork_from_hex_str, u8_from_hex_str};
 pub use test_random::TestRandom;
 pub use testing_attestation_builder::TestingAttestationBuilder;
 pub use testing_attestation_data_builder::TestingAttestationDataBuilder;

eth2/types/src/test_utils/serde_utils.rs

@@ -0,0 +1,28 @@
+use serde::de::Error;
+use serde::{Deserialize, Deserializer};
+
+pub fn u8_from_hex_str<'de, D>(deserializer: D) -> Result<u8, D::Error>
+where
+    D: Deserializer<'de>,
+{
+    let s: String = Deserialize::deserialize(deserializer)?;
+
+    u8::from_str_radix(&s.as_str()[2..], 16).map_err(D::Error::custom)
+}
+
+pub fn fork_from_hex_str<'de, D>(deserializer: D) -> Result<[u8; 4], D::Error>
+where
+    D: Deserializer<'de>,
+{
+    let s: String = Deserialize::deserialize(deserializer)?;
+    let mut array = [0 as u8; 4];
+    let decoded: Vec<u8> = hex::decode(&s.as_str()[2..]).map_err(D::Error::custom)?;
+
+    for (i, item) in array.iter_mut().enumerate() {
+        if i > decoded.len() {
+            break;
+        }
+        *item = decoded[i];
+    }
+    Ok(array)
+}

eth2/types/src/test_utils/testing_beacon_state_builder.rs

@@ -23,6 +23,7 @@ pub fn keypairs_path() -> PathBuf {
 /// Builds a beacon state to be used for testing purposes.
 ///
 /// This struct should **never be used for production purposes.**
+#[derive(Clone)]
 pub struct TestingBeaconStateBuilder {
     state: BeaconState,
     keypairs: Vec<Keypair>,

eth2/utils/bls/src/fake_aggregate_signature.rs

@@ -0,0 +1,117 @@
+use super::{fake_signature::FakeSignature, AggregatePublicKey};
+use serde::de::{Deserialize, Deserializer};
+use serde::ser::{Serialize, Serializer};
+use serde_hex::{encode as hex_encode, PrefixedHexVisitor};
+use ssz::{
+    decode_ssz_list, hash, ssz_encode, Decodable, DecodeError, Encodable, SszStream, TreeHash,
+};
+
+const SIGNATURE_LENGTH: usize = 48;
+
+/// A BLS aggregate signature.
+///
+/// This struct is a wrapper upon a base type and provides helper functions (e.g., SSZ
+/// serialization).
+#[derive(Debug, PartialEq, Clone, Default, Eq)]
+pub struct FakeAggregateSignature {
+    bytes: Vec<u8>,
+}
+
+impl FakeAggregateSignature {
+    /// Creates a new all-zero's signature
+    pub fn new() -> Self {
+        Self::zero()
+    }
+
+    /// Creates a new all-zero's signature
+    pub fn zero() -> Self {
+        Self {
+            bytes: vec![0; SIGNATURE_LENGTH],
+        }
+    }
+
+    /// Does glorious nothing.
+    pub fn add(&mut self, _signature: &FakeSignature) {
+        // Do nothing.
+    }
+
+    /// _Always_ returns `true`.
+    pub fn verify(
+        &self,
+        _msg: &[u8],
+        _domain: u64,
+        _aggregate_public_key: &AggregatePublicKey,
+    ) -> bool {
+        true
+    }
+
+    /// _Always_ returns `true`.
+    pub fn verify_multiple(
+        &self,
+        _messages: &[&[u8]],
+        _domain: u64,
+        _aggregate_public_keys: &[&AggregatePublicKey],
+    ) -> bool {
+        true
+    }
+}
+
+impl Encodable for FakeAggregateSignature {
+    fn ssz_append(&self, s: &mut SszStream) {
+        s.append_vec(&self.bytes);
+    }
+}
+
+impl Decodable for FakeAggregateSignature {
+    fn ssz_decode(bytes: &[u8], i: usize) -> Result<(Self, usize), DecodeError> {
+        let (sig_bytes, i) = decode_ssz_list(bytes, i)?;
+        Ok((FakeAggregateSignature { bytes: sig_bytes }, i))
+    }
+}
+
+impl Serialize for FakeAggregateSignature {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        serializer.serialize_str(&hex_encode(ssz_encode(self)))
+    }
+}
+
+impl<'de> Deserialize<'de> for FakeAggregateSignature {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let bytes = deserializer.deserialize_str(PrefixedHexVisitor)?;
+        let (obj, _) = <_>::ssz_decode(&bytes[..], 0)
+            .map_err(|e| serde::de::Error::custom(format!("invalid ssz ({:?})", e)))?;
+        Ok(obj)
+    }
+}
+
+impl TreeHash for FakeAggregateSignature {
+    fn hash_tree_root(&self) -> Vec<u8> {
+        hash(&self.bytes)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::super::{Keypair, Signature};
+    use super::*;
+    use ssz::ssz_encode;
+
+    #[test]
+    pub fn test_ssz_round_trip() {
+        let keypair = Keypair::random();
+
+        let mut original = FakeAggregateSignature::new();
+        original.add(&Signature::new(&[42, 42], 0, &keypair.sk));
+
+        let bytes = ssz_encode(&original);
+        let (decoded, _) = FakeAggregateSignature::ssz_decode(&bytes, 0).unwrap();
+
+        assert_eq!(original, decoded);
+    }
+}

eth2/utils/bls/src/fake_signature.rs

@@ -0,0 +1,117 @@
+use super::serde_vistors::HexVisitor;
+use super::{PublicKey, SecretKey};
+use hex::encode as hex_encode;
+use serde::de::{Deserialize, Deserializer};
+use serde::ser::{Serialize, Serializer};
+use ssz::{
+    decode_ssz_list, hash, ssz_encode, Decodable, DecodeError, Encodable, SszStream, TreeHash,
+};
+
+const SIGNATURE_LENGTH: usize = 48;
+
+/// A single BLS signature.
+///
+/// This struct is a wrapper upon a base type and provides helper functions (e.g., SSZ
+/// serialization).
+#[derive(Debug, PartialEq, Clone, Eq)]
+pub struct FakeSignature {
+    bytes: Vec<u8>,
+}
+
+impl FakeSignature {
+    /// Creates a new all-zero's signature
+    pub fn new(_msg: &[u8], _domain: u64, _sk: &SecretKey) -> Self {
+        FakeSignature::zero()
+    }
+
+    /// Creates a new all-zero's signature
+    pub fn zero() -> Self {
+        Self {
+            bytes: vec![0; SIGNATURE_LENGTH],
+        }
+    }
+
+    /// Creates a new all-zero's signature
+    pub fn new_hashed(_x_real_hashed: &[u8], _x_imaginary_hashed: &[u8], _sk: &SecretKey) -> Self {
+        FakeSignature::zero()
+    }
+
+    /// _Always_ returns `true`.
+    pub fn verify(&self, _msg: &[u8], _domain: u64, _pk: &PublicKey) -> bool {
+        true
+    }
+
+    /// _Always_ returns true.
+    pub fn verify_hashed(
+        &self,
+        _x_real_hashed: &[u8],
+        _x_imaginary_hashed: &[u8],
+        _pk: &PublicKey,
+    ) -> bool {
+        true
+    }
+
+    /// Returns a new empty signature.
+    pub fn empty_signature() -> Self {
+        FakeSignature::zero()
+    }
+}
+
+impl Encodable for FakeSignature {
+    fn ssz_append(&self, s: &mut SszStream) {
+        s.append_vec(&self.bytes);
+    }
+}
+
+impl Decodable for FakeSignature {
+    fn ssz_decode(bytes: &[u8], i: usize) -> Result<(Self, usize), DecodeError> {
+        let (sig_bytes, i) = decode_ssz_list(bytes, i)?;
+        Ok((FakeSignature { bytes: sig_bytes }, i))
+    }
+}
+
+impl TreeHash for FakeSignature {
+    fn hash_tree_root(&self) -> Vec<u8> {
+        hash(&self.bytes)
+    }
+}
+
+impl Serialize for FakeSignature {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        serializer.serialize_str(&hex_encode(ssz_encode(self)))
+    }
+}
+
+impl<'de> Deserialize<'de> for FakeSignature {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let bytes = deserializer.deserialize_str(HexVisitor)?;
+        let (pubkey, _) = <_>::ssz_decode(&bytes[..], 0)
+            .map_err(|e| serde::de::Error::custom(format!("invalid ssz ({:?})", e)))?;
+        Ok(pubkey)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::super::Keypair;
+    use super::*;
+    use ssz::ssz_encode;
+
+    #[test]
+    pub fn test_ssz_round_trip() {
+        let keypair = Keypair::random();
+
+        let original = FakeSignature::new(&[42, 42], 0, &keypair.sk);
+
+        let bytes = ssz_encode(&original);
+        let (decoded, _) = FakeSignature::ssz_decode(&bytes, 0).unwrap();
+
+        assert_eq!(original, decoded);
+    }
+}

eth2/utils/bls/src/keypair.rs

@@ -14,4 +14,8 @@ impl Keypair {
         let pk = PublicKey::from_secret_key(&sk);
         Keypair { sk, pk }
     }
+
+    pub fn identifier(&self) -> String {
+        self.pk.concatenated_hex_id()
+    }
 }

eth2/utils/bls/src/lib.rs

@@ -2,19 +2,33 @@ extern crate bls_aggregates;
 extern crate ssz;
 
 mod aggregate_public_key;
-mod aggregate_signature;
 mod keypair;
 mod public_key;
 mod secret_key;
 mod serde_vistors;
+
+#[cfg(not(debug_assertions))]
+mod aggregate_signature;
+#[cfg(not(debug_assertions))]
 mod signature;
+#[cfg(not(debug_assertions))]
+pub use crate::aggregate_signature::AggregateSignature;
+#[cfg(not(debug_assertions))]
+pub use crate::signature::Signature;
+
+#[cfg(debug_assertions)]
+mod fake_aggregate_signature;
+#[cfg(debug_assertions)]
+mod fake_signature;
+#[cfg(debug_assertions)]
+pub use crate::fake_aggregate_signature::FakeAggregateSignature as AggregateSignature;
+#[cfg(debug_assertions)]
+pub use crate::fake_signature::FakeSignature as Signature;
 
 pub use crate::aggregate_public_key::AggregatePublicKey;
-pub use crate::aggregate_signature::AggregateSignature;
 pub use crate::keypair::Keypair;
 pub use crate::public_key::PublicKey;
 pub use crate::secret_key::SecretKey;
-pub use crate::signature::Signature;
 
 pub const BLS_AGG_SIG_BYTE_SIZE: usize = 96;
 

eth2/utils/bls/src/serde_vistors.rs

@@ -8,13 +8,14 @@ impl<'de> Visitor<'de> for HexVisitor {
     type Value = Vec<u8>;
 
     fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-        formatter.write_str("a hex string (without 0x prefix)")
+        formatter.write_str("a hex string (irrelevant of prefix)")
     }
 
     fn visit_str<E>(self, value: &str) -> Result<Self::Value, E>
     where
         E: de::Error,
     {
-        Ok(hex::decode(value).map_err(|e| de::Error::custom(format!("invalid hex ({:?})", e)))?)
+        Ok(hex::decode(value.trim_start_matches("0x"))
+            .map_err(|e| de::Error::custom(format!("invalid hex ({:?})", e)))?)
     }
 }

eth2/utils/bls/src/signature.rs

@@ -13,27 +13,35 @@ use ssz::{
 /// This struct is a wrapper upon a base type and provides helper functions (e.g., SSZ
 /// serialization).
 #[derive(Debug, PartialEq, Clone, Eq)]
-pub struct Signature(RawSignature);
+pub struct Signature {
+    signature: RawSignature,
+    is_empty: bool,
+}
 
 impl Signature {
     /// Instantiate a new Signature from a message and a SecretKey.
     pub fn new(msg: &[u8], domain: u64, sk: &SecretKey) -> Self {
-        Signature(RawSignature::new(msg, domain, sk.as_raw()))
+        Signature {
+            signature: RawSignature::new(msg, domain, sk.as_raw()),
+            is_empty: false,
+        }
     }
 
     /// Instantiate a new Signature from a message and a SecretKey, where the message has already
     /// been hashed.
     pub fn new_hashed(x_real_hashed: &[u8], x_imaginary_hashed: &[u8], sk: &SecretKey) -> Self {
-        Signature(RawSignature::new_hashed(
-            x_real_hashed,
-            x_imaginary_hashed,
-            sk.as_raw(),
-        ))
+        Signature {
+            signature: RawSignature::new_hashed(x_real_hashed, x_imaginary_hashed, sk.as_raw()),
+            is_empty: false,
+        }
     }
 
     /// Verify the Signature against a PublicKey.
     pub fn verify(&self, msg: &[u8], domain: u64, pk: &PublicKey) -> bool {
-        self.0.verify(msg, domain, pk.as_raw())
+        if self.is_empty {
+            return false;
+        }
+        self.signature.verify(msg, domain, pk.as_raw())
     }
 
     /// Verify the Signature against a PublicKey, where the message has already been hashed.
@@ -43,44 +51,72 @@ impl Signature {
         x_imaginary_hashed: &[u8],
         pk: &PublicKey,
     ) -> bool {
-        self.0
+        self.signature
             .verify_hashed(x_real_hashed, x_imaginary_hashed, pk.as_raw())
     }
 
     /// Returns the underlying signature.
     pub fn as_raw(&self) -> &RawSignature {
-        &self.0
+        &self.signature
     }
 
     /// Returns a new empty signature.
     pub fn empty_signature() -> Self {
-        // Empty Signature is currently being represented as BLS::Signature.point_at_infinity()
-        // However it should be represented as vec![0; 96] but this
-        // would require all signatures to be represented in byte form as opposed to Signature
+        // Set RawSignature = infinity
         let mut empty: Vec<u8> = vec![0; 96];
-        // Sets C_flag and B_flag to 1 and all else to 0
         empty[0] += u8::pow(2, 6) + u8::pow(2, 7);
-        Signature(RawSignature::from_bytes(&empty).unwrap())
+        Signature {
+            signature: RawSignature::from_bytes(&empty).unwrap(),
+            is_empty: true,
+        }
+    }
+
+    // Converts a BLS Signature to bytes
+    pub fn as_bytes(&self) -> Vec<u8> {
+        if self.is_empty {
+            return vec![0; 96];
+        }
+        self.signature.as_bytes()
+    }
+
+    // Convert bytes to BLS Signature
+    pub fn from_bytes(bytes: &[u8]) -> Result<Self, DecodeError> {
+        for byte in bytes {
+            if *byte != 0 {
+                let raw_signature =
+                    RawSignature::from_bytes(&bytes).map_err(|_| DecodeError::Invalid)?;
+                return Ok(Signature {
+                    signature: raw_signature,
+                    is_empty: false,
+                });
+            }
+        }
+        Ok(Signature::empty_signature())
+    }
+
+    // Check for empty Signature
+    pub fn is_empty(&self) -> bool {
+        self.is_empty
     }
 }
 
 impl Encodable for Signature {
     fn ssz_append(&self, s: &mut SszStream) {
-        s.append_vec(&self.0.as_bytes());
+        s.append_vec(&self.as_bytes());
     }
 }
 
 impl Decodable for Signature {
     fn ssz_decode(bytes: &[u8], i: usize) -> Result<(Self, usize), DecodeError> {
         let (sig_bytes, i) = decode_ssz_list(bytes, i)?;
-        let raw_sig = RawSignature::from_bytes(&sig_bytes).map_err(|_| DecodeError::TooShort)?;
-        Ok((Signature(raw_sig), i))
+        let signature = Signature::from_bytes(&sig_bytes)?;
+        Ok((signature, i))
     }
 }
 
 impl TreeHash for Signature {
     fn hash_tree_root(&self) -> Vec<u8> {
-        hash(&self.0.as_bytes())
+        hash(&self.as_bytes())
     }
 }
 

validator_client/Cargo.toml

@@ -4,6 +4,15 @@ version = "0.1.0"
 authors = ["Paul Hauner <paul@paulhauner.com>"]
 edition = "2018"
 
+[[bin]]
+name = "validator_client"
+path = "src/main.rs"
+
+[lib]
+name = "validator_client"
+path = "src/lib.rs"
+
+
 [dependencies]
 block_proposer = { path = "../eth2/block_proposer" }
 bls = { path = "../eth2/utils/bls" }
@@ -18,3 +27,4 @@ slog = "^2.2.3"
 slog-term = "^2.4.0"
 slog-async = "^2.3.0"
 ssz = { path = "../eth2/utils/ssz" }
+bincode = "^1.1.2"

validator_client/README.md

@@ -57,10 +57,30 @@ complete and return a block from the BN.
 
 ### Configuration
 
-Presently the validator specifics (pubkey, etc.) are randomly generated and the
-chain specification (slot length, BLS domain, etc.) are fixed to foundation
-parameters. This is temporary and will be upgrade so these parameters can be
-read from file (or initialized on first-boot).
+Validator configurations are stored in a separate data directory from the main Beacon Node
+binary. The validator data directory defaults to:
+`$HOME/.lighthouse-validator`, however an alternative can be specified on the command line
+with `--datadir`.
+
+The configuration directory structure looks like:
+```
+~/.lighthouse-validator
+    ├── 3cf4210d58ec
+    │   └── private.key
+    ├── 9b5d8b5be4e7
+    │   └── private.key
+    └── cf6e07188f48
+        └── private.key
+```
+
+Where the hex value of the directory is a portion of the validator public key.
+
+Validator keys must be generated using the separate `accounts_manager` binary, which will
+place the keys into this directory structure in a format compatible with the validator client.
+
+The chain specification (slot length, BLS domain, etc.) defaults to foundation
+parameters, however is temporary and an upgrade will allow these parameters to be
+read from a file (or initialized on first-boot).
 
 ## BN Communication
 

validator_client/src/config.rs

@@ -1,28 +1,39 @@
+use bincode;
+use bls::Keypair;
+use clap::ArgMatches;
+use slog::{debug, error, info};
 use std::fs;
+use std::fs::File;
+use std::io::{Error, ErrorKind};
 use std::path::PathBuf;
 use types::ChainSpec;
 
 /// Stores the core configuration for this validator instance.
 #[derive(Clone)]
-pub struct ClientConfig {
+pub struct Config {
+    /// The data directory, which stores all validator databases
     pub data_dir: PathBuf,
+    /// The server at which the Beacon Node can be contacted
     pub server: String,
+    /// The chain specification that we are connecting to
     pub spec: ChainSpec,
 }
 
-const DEFAULT_LIGHTHOUSE_DIR: &str = ".lighthouse-validators";
+const DEFAULT_PRIVATE_KEY_FILENAME: &str = "private.key";
 
-impl ClientConfig {
-    /// Build a new configuration from defaults.
-    pub fn default() -> Self {
+impl Default for Config {
+    fn default() -> Self {
         let data_dir = {
-            let home = dirs::home_dir().expect("Unable to determine home dir.");
-            home.join(DEFAULT_LIGHTHOUSE_DIR)
+            let home = dirs::home_dir().expect("Unable to determine home directory.");
+            home.join(".lighthouse-validator")
         };
         fs::create_dir_all(&data_dir)
             .unwrap_or_else(|_| panic!("Unable to create {:?}", &data_dir));
+
         let server = "localhost:50051".to_string();
+
         let spec = ChainSpec::foundation();
+
         Self {
             data_dir,
             server,
@@ -30,3 +41,114 @@ impl ClientConfig {
         }
     }
 }
+
+impl Config {
+    /// Build a new configuration from defaults, which are overrided by arguments provided.
+    pub fn parse_args(args: &ArgMatches, log: &slog::Logger) -> Result<Self, Error> {
+        let mut config = Config::default();
+
+        // Use the specified datadir, or default in the home directory
+        if let Some(datadir) = args.value_of("datadir") {
+            config.data_dir = PathBuf::from(datadir);
+            fs::create_dir_all(&config.data_dir)
+                .unwrap_or_else(|_| panic!("Unable to create {:?}", &config.data_dir));
+            info!(log, "Using custom data dir: {:?}", &config.data_dir);
+        };
+
+        if let Some(srv) = args.value_of("server") {
+            //TODO: I don't think this parses correctly a server & port combo
+            config.server = srv.to_string();
+            info!(log, "Using custom server: {:?}", &config.server);
+        };
+
+        // TODO: Permit loading a custom spec from file.
+        if let Some(spec_str) = args.value_of("spec") {
+            info!(log, "Using custom spec: {:?}", spec_str);
+            config.spec = match spec_str {
+                "foundation" => ChainSpec::foundation(),
+                "few_validators" => ChainSpec::few_validators(),
+                // Should be impossible due to clap's `possible_values(..)` function.
+                _ => unreachable!(),
+            };
+        };
+
+        Ok(config)
+    }
+
+    /// Try to load keys from validator_dir, returning None if none are found or an error.
+    pub fn fetch_keys(&self, log: &slog::Logger) -> Option<Vec<Keypair>> {
+        let key_pairs: Vec<Keypair> = fs::read_dir(&self.data_dir)
+            .unwrap()
+            .filter_map(|validator_dir| {
+                let validator_dir = validator_dir.ok()?;
+
+                if !(validator_dir.file_type().ok()?.is_dir()) {
+                    // Skip non-directories (i.e. no files/symlinks)
+                    return None;
+                }
+
+                let key_filename = validator_dir.path().join(DEFAULT_PRIVATE_KEY_FILENAME);
+
+                if !(key_filename.is_file()) {
+                    info!(
+                        log,
+                        "Private key is not a file: {:?}",
+                        key_filename.to_str()
+                    );
+                    return None;
+                }
+
+                debug!(
+                    log,
+                    "Deserializing private key from file: {:?}",
+                    key_filename.to_str()
+                );
+
+                let mut key_file = File::open(key_filename.clone()).ok()?;
+
+                let key: Keypair = if let Ok(key_ok) = bincode::deserialize_from(&mut key_file) {
+                    key_ok
+                } else {
+                    error!(
+                        log,
+                        "Unable to deserialize the private key file: {:?}", key_filename
+                    );
+                    return None;
+                };
+
+                let ki = key.identifier();
+                if ki != validator_dir.file_name().into_string().ok()? {
+                    error!(
+                        log,
+                        "The validator key ({:?}) did not match the directory filename {:?}.",
+                        ki,
+                        &validator_dir.path().to_string_lossy()
+                    );
+                    return None;
+                }
+                Some(key)
+            })
+            .collect();
+
+        // Check if it's an empty vector, and return none.
+        if key_pairs.is_empty() {
+            None
+        } else {
+            Some(key_pairs)
+        }
+    }
+
+    /// Saves a keypair to a file inside the appropriate validator directory. Returns the saved path filename.
+    pub fn save_key(&self, key: &Keypair) -> Result<PathBuf, Error> {
+        let validator_config_path = self.data_dir.join(key.identifier());
+        let key_path = validator_config_path.join(DEFAULT_PRIVATE_KEY_FILENAME);
+
+        fs::create_dir_all(&validator_config_path)?;
+
+        let mut key_file = File::create(&key_path)?;
+
+        bincode::serialize_into(&mut key_file, &key)
+            .map_err(|e| Error::new(ErrorKind::InvalidData, e))?;
+        Ok(key_path)
+    }
+}

validator_client/src/lib.rs

@@ -0,0 +1,3 @@
+pub mod config;
+
+pub use crate::config::Config;

validator_client/src/main.rs

@@ -1,17 +1,14 @@
 use self::block_producer_service::{BeaconBlockGrpcClient, BlockProducerService};
 use self::duties::{DutiesManager, DutiesManagerService, EpochDutiesMap};
-use crate::config::ClientConfig;
+use crate::config::Config;
 use block_proposer::{test_utils::LocalSigner, BlockProducer};
-use bls::Keypair;
 use clap::{App, Arg};
 use grpcio::{ChannelBuilder, EnvBuilder};
 use protos::services_grpc::{BeaconBlockServiceClient, ValidatorServiceClient};
-use slog::{error, info, o, Drain};
+use slog::{info, o, Drain};
 use slot_clock::SystemTimeSlotClock;
-use std::path::PathBuf;
 use std::sync::Arc;
 use std::thread;
-use types::ChainSpec;
 
 mod block_producer_service;
 mod config;
@@ -55,36 +52,11 @@ fn main() {
         )
         .get_matches();
 
-    let mut config = ClientConfig::default();
-
-    // Custom datadir
-    if let Some(dir) = matches.value_of("datadir") {
-        config.data_dir = PathBuf::from(dir.to_string());
-    }
-
-    // Custom server port
-    if let Some(server_str) = matches.value_of("server") {
-        if let Ok(addr) = server_str.parse::<u16>() {
-            config.server = addr.to_string();
-        } else {
-            error!(log, "Invalid address"; "server" => server_str);
-            return;
-        }
-    }
-
-    // TODO: Permit loading a custom spec from file.
-    // Custom spec
-    if let Some(spec_str) = matches.value_of("spec") {
-        match spec_str {
-            "foundation" => config.spec = ChainSpec::foundation(),
-            "few_validators" => config.spec = ChainSpec::few_validators(),
-            // Should be impossible due to clap's `possible_values(..)` function.
-            _ => unreachable!(),
-        };
-    }
+    let config = Config::parse_args(&matches, &log)
+        .expect("Unable to build a configuration for the validator client.");
 
     // Log configuration
-    info!(log, "";
+    info!(log, "Configuration parameters:";
           "data_dir" => &config.data_dir.to_str(),
           "server" => &config.server);
 
@@ -119,13 +91,13 @@ fn main() {
     let poll_interval_millis = spec.seconds_per_slot * 1000 / 10; // 10% epoch time precision.
     info!(log, "Starting block producer service"; "polls_per_epoch" => spec.seconds_per_slot * 1000 / poll_interval_millis);
 
+    let keypairs = config.fetch_keys(&log)
+        .expect("No key pairs found in configuration, they must first be generated with: account_manager generate.");
+
     /*
      * Start threads.
      */
     let mut threads = vec![];
-    // TODO: keypairs are randomly generated; they should be loaded from a file or generated.
-    // https://github.com/sigp/lighthouse/issues/160
-    let keypairs = vec![Keypair::random()];
 
     for keypair in keypairs {
         info!(log, "Starting validator services"; "validator" => keypair.pk.concatenated_hex_id());