Add transfer processing to BeaconChain

beacon_node/beacon_chain/src/beacon_chain.rs

@@ -56,6 +56,7 @@ pub struct BeaconChain<T: ClientDB + Sized, U: SlotClock, F: ForkChoice> {
     pub attestation_aggregator: RwLock<AttestationAggregator>,
     pub deposits_for_inclusion: RwLock<Vec<Deposit>>,
     pub exits_for_inclusion: RwLock<Vec<VoluntaryExit>>,
+    pub transfers_for_inclusion: RwLock<Vec<Transfer>>,
     pub proposer_slashings_for_inclusion: RwLock<Vec<ProposerSlashing>>,
     pub attester_slashings_for_inclusion: RwLock<Vec<AttesterSlashing>>,
     canonical_head: RwLock<CheckPoint>,
@@ -126,6 +127,7 @@ where
             attestation_aggregator,
             deposits_for_inclusion: RwLock::new(vec![]),
             exits_for_inclusion: RwLock::new(vec![]),
+            transfers_for_inclusion: RwLock::new(vec![]),
             proposer_slashings_for_inclusion: RwLock::new(vec![]),
             attester_slashings_for_inclusion: RwLock::new(vec![]),
             state: RwLock::new(genesis_state),
@@ -436,6 +438,44 @@ where
         }
     }
 
+    /// Accept some transfer and queue it for inclusion in an appropriate block.
+    pub fn receive_transfer_for_inclusion(&self, transfer: Transfer) {
+        // TODO: transfers are not checked for validity; check them.
+        //
+        // https://github.com/sigp/lighthouse/issues/276
+        self.transfers_for_inclusion.write().push(transfer);
+    }
+
+    /// Return a vec of transfers suitable for inclusion in some block.
+    pub fn get_transfers_for_block(&self) -> Vec<Transfer> {
+        // TODO: transfers are indiscriminately included; check them for validity.
+        //
+        // https://github.com/sigp/lighthouse/issues/275
+        self.transfers_for_inclusion.read().clone()
+    }
+
+    /// Takes a list of `Deposits` that were included in recent blocks and removes them from the
+    /// inclusion queue.
+    ///
+    /// This ensures that `Deposits` are not included twice in successive blocks.
+    pub fn set_transfers_as_included(&self, included_transfers: &[Transfer]) {
+        // TODO: method does not take forks into account; consider this.
+        let mut indices_to_delete = vec![];
+
+        for included in included_transfers {
+            for (i, for_inclusion) in self.transfers_for_inclusion.read().iter().enumerate() {
+                if included == for_inclusion {
+                    indices_to_delete.push(i);
+                }
+            }
+        }
+
+        let transfers_for_inclusion = &mut self.transfers_for_inclusion.write();
+        for i in indices_to_delete {
+            transfers_for_inclusion.remove(i);
+        }
+    }
+
     /// Accept some proposer slashing and queue it for inclusion in an appropriate block.
     pub fn receive_proposer_slashing_for_inclusion(&self, proposer_slashing: ProposerSlashing) {
         // TODO: proposer_slashings are not checked for validity; check them.
@@ -664,6 +704,8 @@ where
 
         // Update the inclusion queues so they aren't re-submitted.
         self.set_deposits_as_included(&block.body.deposits[..]);
+        self.set_transfers_as_included(&block.body.transfers[..]);
+        self.set_exits_as_included(&block.body.voluntary_exits[..]);
         self.set_proposer_slashings_as_included(&block.body.proposer_slashings[..]);
         self.set_attester_slashings_as_included(&block.body.attester_slashings[..]);
 
@@ -730,7 +772,7 @@ where
                 attestations,
                 deposits: self.get_deposits_for_block(),
                 voluntary_exits: self.get_exits_for_block(),
-                transfers: vec![],
+                transfers: self.get_transfers_for_block(),
             },
         };
 

beacon_node/beacon_chain/test_harness/specs/validator_registry.yaml

@@ -10,18 +10,23 @@ test_cases:
       num_slots: 64
       skip_slots: [2, 3]
       deposits:
-          # At slot 1, create a new validator deposit of 32 ETH.
+          # At slot 1, create a new validator deposit of 5 ETH.
         - slot: 1
-          amount: 32
+          amount: 5000000000
           # Trigger more deposits...
         - slot: 3
-          amount: 32
+          amount: 5000000000
         - slot: 5
-          amount: 32
+          amount: 32000000000
       exits:
           # At slot 10, submit an exit for validator #50.
         - slot: 10
           validator_index: 50
+      transfers:
+        - slot: 6
+          from: 1000
+          to: 1001
+          amount: 5000000000
       proposer_slashings:
           # At slot 2, trigger a proposer slashing for validator #42.
         - slot: 2
@@ -44,4 +49,11 @@ test_cases:
           slashed_validators: [11, 12, 13, 14, 42]
           exited_validators: []
           exit_initiated_validators: [50]
+          balances:
+            - validator_index: 1000
+              comparison: "eq"
+              balance: 0
+            - validator_index: 1001
+              comparison: "eq"
+              balance: 10000000000
 

beacon_node/beacon_chain/test_harness/src/beacon_chain_harness.rs

@@ -1,7 +1,7 @@
 use super::ValidatorHarness;
 use beacon_chain::{BeaconChain, BlockProcessingOutcome};
 pub use beacon_chain::{BeaconChainError, CheckPoint};
-use bls::create_proof_of_possession;
+use bls::{create_proof_of_possession, get_withdrawal_credentials};
 use db::{
     stores::{BeaconBlockStore, BeaconStateStore},
     MemoryDB,
@@ -67,7 +67,13 @@ impl BeaconChainHarness {
                     timestamp: genesis_time - 1,
                     deposit_input: DepositInput {
                         pubkey: keypair.pk.clone(),
-                        withdrawal_credentials: Hash256::zero(), // Withdrawal not possible.
+                        // Validator can withdraw using their main keypair.
+                        withdrawal_credentials: Hash256::from_slice(
+                            &get_withdrawal_credentials(
+                                &keypair.pk,
+                                spec.bls_withdrawal_prefix_byte,
+                            )[..],
+                        ),
                         proof_of_possession: create_proof_of_possession(&keypair),
                     },
                 },
@@ -286,6 +292,11 @@ impl BeaconChainHarness {
         self.beacon_chain.receive_exit_for_inclusion(exit);
     }
 
+    /// Submit an transfer to the `BeaconChain` for inclusion in some block.
+    pub fn add_transfer(&mut self, transfer: Transfer) {
+        self.beacon_chain.receive_transfer_for_inclusion(transfer);
+    }
+
     /// Submit a proposer slashing to the `BeaconChain` for inclusion in some block.
     pub fn add_proposer_slashing(&mut self, proposer_slashing: ProposerSlashing) {
         self.beacon_chain

beacon_node/beacon_chain/test_harness/src/test_case.rs

@@ -3,7 +3,7 @@
 
 use crate::beacon_chain_harness::BeaconChainHarness;
 use beacon_chain::CheckPoint;
-use bls::create_proof_of_possession;
+use bls::{create_proof_of_possession, get_withdrawal_credentials};
 use log::{info, warn};
 use ssz::SignedRoot;
 use types::*;
@@ -83,8 +83,8 @@ impl TestCase {
 
         info!("Starting simulation across {} slots...", slots);
 
-        // -1 slots because genesis counts as a slot.
-        for slot_height in 0..slots - 1 {
+        // Start at 1 because genesis counts as a slot.
+        for slot_height in 1..slots {
             // Used to ensure that deposits in the same slot have incremental deposit indices.
             let mut deposit_index_offset = 0;
 
@@ -144,6 +144,20 @@ impl TestCase {
                 }
             }
 
+            // Feed transfers to the BeaconChain.
+            if let Some(ref transfers) = self.config.transfers {
+                for (slot, from, to, amount) in transfers {
+                    if *slot == slot_height {
+                        info!(
+                            "Including transfer at slot height {} from validator {}.",
+                            slot_height, from
+                        );
+                        let transfer = build_transfer(&harness, *from, *to, *amount);
+                        harness.add_transfer(transfer);
+                    }
+                }
+            }
+
             // Build a block or skip a slot.
             match self.config.skip_slots {
                 Some(ref skip_slots) if skip_slots.contains(&slot_height) => {
@@ -208,6 +222,30 @@ impl TestCase {
     }
 }
 
+/// Builds a `Deposit` this is valid for the given `BeaconChainHarness` at its next slot.
+fn build_transfer(harness: &BeaconChainHarness, from: u64, to: u64, amount: u64) -> Transfer {
+    let slot = harness.beacon_chain.state.read().slot + 1;
+
+    let mut transfer = Transfer {
+        from,
+        to,
+        amount,
+        fee: 0,
+        slot,
+        pubkey: harness.validators[from as usize].keypair.pk.clone(),
+        signature: Signature::empty_signature(),
+    };
+
+    let message = transfer.signed_root();
+    let epoch = slot.epoch(harness.spec.slots_per_epoch);
+
+    transfer.signature = harness
+        .validator_sign(from as usize, &message[..], epoch, Domain::Transfer)
+        .expect("Unable to sign Transfer");
+
+    transfer
+}
+
 /// Builds a `Deposit` this is valid for the given `BeaconChainHarness`.
 ///
 /// `index_offset` is used to ensure that `deposit.index == state.index` when adding multiple
@@ -220,8 +258,9 @@ fn build_deposit(
     let keypair = Keypair::random();
     let proof_of_possession = create_proof_of_possession(&keypair);
     let index = harness.beacon_chain.state.read().deposit_index + index_offset;
-
-    info!("index: {}, index_offset: {}", index, index_offset);
+    let withdrawal_credentials = Hash256::from_slice(
+        &get_withdrawal_credentials(&keypair.pk, harness.spec.bls_withdrawal_prefix_byte)[..],
+    );
 
     let deposit = Deposit {
         // Note: `branch` and `index` will need to be updated once the spec defines their
@@ -233,7 +272,7 @@ fn build_deposit(
             timestamp: 1,
             deposit_input: DepositInput {
                 pubkey: keypair.pk.clone(),
-                withdrawal_credentials: Hash256::zero(),
+                withdrawal_credentials,
                 proof_of_possession,
             },
         },

beacon_node/beacon_chain/test_harness/src/test_case/config.rs

@@ -10,6 +10,8 @@ pub type DepositTuple = (SlotHeight, GweiAmount);
 pub type ExitTuple = (SlotHeight, ValidatorIndex);
 pub type ProposerSlashingTuple = (SlotHeight, ValidatorIndex);
 pub type AttesterSlashingTuple = (SlotHeight, ValidatorIndices);
+/// (slot_height, from, to, amount)
+pub type TransferTuple = (SlotHeight, ValidatorIndex, ValidatorIndex, GweiAmount);
 
 /// Defines the execution of a `BeaconStateHarness` across a series of slots.
 #[derive(Debug)]
@@ -30,6 +32,8 @@ pub struct Config {
     pub attester_slashings: Option<Vec<AttesterSlashingTuple>>,
     /// Exits to be including during execution.
     pub exits: Option<Vec<ExitTuple>>,
+    /// Transfers to be including during execution.
+    pub transfers: Option<Vec<TransferTuple>>,
 }
 
 impl Config {
@@ -47,10 +51,27 @@ impl Config {
             proposer_slashings: parse_proposer_slashings(&yaml),
             attester_slashings: parse_attester_slashings(&yaml),
             exits: parse_exits(&yaml),
+            transfers: parse_transfers(&yaml),
         }
     }
 }
 
+/// Parse the `transfers` section of the YAML document.
+fn parse_transfers(yaml: &Yaml) -> Option<Vec<TransferTuple>> {
+    let mut tuples = vec![];
+
+    for exit in yaml["transfers"].as_vec()? {
+        let slot = as_u64(exit, "slot").expect("Incomplete transfer (slot)");
+        let from = as_u64(exit, "from").expect("Incomplete transfer (from)");
+        let to = as_u64(exit, "to").expect("Incomplete transfer (to)");
+        let amount = as_u64(exit, "amount").expect("Incomplete transfer (amount)");
+
+        tuples.push((SlotHeight::from(slot), from, to, amount));
+    }
+
+    Some(tuples)
+}
+
 /// Parse the `attester_slashings` section of the YAML document.
 fn parse_exits(yaml: &Yaml) -> Option<Vec<ExitTuple>> {
     let mut tuples = vec![];
@@ -102,8 +123,7 @@ fn parse_deposits(yaml: &Yaml) -> Option<Vec<DepositTuple>> {
 
     for deposit in yaml["deposits"].as_vec()? {
         let slot = as_u64(deposit, "slot").expect("Incomplete deposit (slot)");
-        let amount =
-            as_u64(deposit, "amount").expect("Incomplete deposit (amount)") * 1_000_000_000;
+        let amount = as_u64(deposit, "amount").expect("Incomplete deposit (amount)");
 
         deposits.push((SlotHeight::from(slot), amount))
     }

beacon_node/beacon_chain/test_harness/src/test_case/state_check.rs

@@ -3,6 +3,11 @@ use log::info;
 use types::*;
 use yaml_rust::Yaml;
 
+type ValidatorIndex = u64;
+type BalanceGwei = u64;
+
+type BalanceCheckTuple = (ValidatorIndex, String, BalanceGwei);
+
 /// Tests to be conducted upon a `BeaconState` object generated during the execution of a
 /// `TestCase`.
 #[derive(Debug)]
@@ -17,6 +22,8 @@ pub struct StateCheck {
     pub exited_validators: Option<Vec<u64>>,
     /// A list of validator indices which have had an exit initiated. Must be in ascending order.
     pub exit_initiated_validators: Option<Vec<u64>>,
+    /// A list of balances to check.
+    pub balances: Option<Vec<BalanceCheckTuple>>,
 }
 
 impl StateCheck {
@@ -30,6 +37,7 @@ impl StateCheck {
             slashed_validators: as_vec_u64(&yaml, "slashed_validators"),
             exited_validators: as_vec_u64(&yaml, "exited_validators"),
             exit_initiated_validators: as_vec_u64(&yaml, "exit_initiated_validators"),
+            balances: parse_balances(&yaml),
         }
     }
 
@@ -124,5 +132,47 @@ impl StateCheck {
                 exit_initiated_validators
             );
         }
+
+        // Check validator balances.
+        if let Some(ref balances) = self.balances {
+            for (index, comparison, expected) in balances {
+                let actual = *state
+                    .validator_balances
+                    .get(*index as usize)
+                    .expect("Balance check specifies unknown validator");
+
+                let result = match comparison.as_ref() {
+                    "eq" => actual == *expected,
+                    _ => panic!("Unknown balance comparison (use `eq`)"),
+                };
+                assert!(
+                    result,
+                    format!(
+                        "Validator balance for {}: {} !{} {}.",
+                        index, actual, comparison, expected
+                    )
+                );
+                info!("OK: validator balance for {:?}.", index);
+            }
+        }
     }
 }
+
+/// Parse the `transfers` section of the YAML document.
+fn parse_balances(yaml: &Yaml) -> Option<Vec<BalanceCheckTuple>> {
+    let mut tuples = vec![];
+
+    for exit in yaml["balances"].as_vec()? {
+        let from =
+            as_u64(exit, "validator_index").expect("Incomplete balance check (validator_index)");
+        let comparison = exit["comparison"]
+            .clone()
+            .into_string()
+            .expect("Incomplete balance check (amount)");
+        let balance = as_u64(exit, "balance").expect("Incomplete balance check (balance)");
+
+        tuples.push((from, comparison, balance));
+    }
+
+    Some(tuples)
+}

eth2/state_processing/src/per_block_processing/errors.rs

@@ -365,7 +365,9 @@ pub enum TransferInvalid {
     /// (from_validator)
     FromValidatorIneligableForTransfer(u64),
     /// The validators withdrawal credentials do not match `transfer.pubkey`.
-    WithdrawalCredentialsMismatch,
+    ///
+    /// (state_credentials, transfer_pubkey_credentials)
+    WithdrawalCredentialsMismatch(Hash256, Hash256),
     /// The deposit was not signed by `deposit.pubkey`.
     BadSignature,
     /// Overflow when adding to `transfer.to` balance.

eth2/state_processing/src/per_block_processing/verify_transfer.rs

@@ -64,7 +64,10 @@ pub fn verify_transfer(
     );
     verify!(
         from_validator.withdrawal_credentials == transfer_withdrawal_credentials,
-        Invalid::WithdrawalCredentialsMismatch
+        Invalid::WithdrawalCredentialsMismatch(
+            from_validator.withdrawal_credentials,
+            transfer_withdrawal_credentials
+        )
     );
 
     let message = transfer.signed_root();