lighthouse/beacon_node/beacon_chain/src/block_verification.rs
Paul Hauner 67a6f91df6
[Merge] Optimistic EL verification (#2683)
* Ignore payload errors

* Only return payload handle on valid response

* Push some engine logs down to debug

* Push ee fork choice log to debug

* Push engine call failure to debug

* Push some more errors to debug

* Fix panic at startup
2021-12-02 14:26:53 +11:00

1782 lines
67 KiB
Rust

//! Provides `SignedBeaconBlock` verification logic.
//!
//! Specifically, it provides the following:
//!
//! - Verification for gossip blocks (i.e., should we gossip some block from the network).
//! - Verification for normal blocks (e.g., some block received on the RPC during a parent lookup).
//! - Verification for chain segments (e.g., some chain of blocks received on the RPC during a
//! sync).
//!
//! The primary source of complexity here is that we wish to avoid doing duplicate work as a block
//! moves through the verification process. For example, if some block is verified for gossip, we
//! do not wish to re-verify the block proposal signature or re-hash the block. Or, if we've
//! verified the signatures of a block during a chain segment import, we do not wish to verify each
//! signature individually again.
//!
//! The incremental processing steps (e.g., signatures verified but not the state transition) is
//! represented as a sequence of wrapper-types around the block. There is a linear progression of
//! types, starting at a `SignedBeaconBlock` and finishing with a `Fully VerifiedBlock` (see
//! diagram below).
//!
//! ```ignore
//! START
//! |
//! ▼
//! SignedBeaconBlock
//! |---------------
//! | |
//! | ▼
//! | GossipVerifiedBlock
//! | |
//! |---------------
//! |
//! ▼
//! SignatureVerifiedBlock
//! |
//! ▼
//! FullyVerifiedBlock
//! |
//! ▼
//! END
//!
//! ```
use crate::snapshot_cache::PreProcessingSnapshot;
use crate::validator_monitor::HISTORIC_EPOCHS as VALIDATOR_MONITOR_HISTORIC_EPOCHS;
use crate::validator_pubkey_cache::ValidatorPubkeyCache;
use crate::{
beacon_chain::{
BLOCK_PROCESSING_CACHE_LOCK_TIMEOUT, MAXIMUM_GOSSIP_CLOCK_DISPARITY,
VALIDATOR_PUBKEY_CACHE_LOCK_TIMEOUT,
},
metrics, BeaconChain, BeaconChainError, BeaconChainTypes,
};
use execution_layer::ExecutePayloadResponse;
use fork_choice::{ForkChoice, ForkChoiceStore};
use parking_lot::RwLockReadGuard;
use proto_array::Block as ProtoBlock;
use safe_arith::ArithError;
use slog::{debug, error, info, Logger};
use slot_clock::SlotClock;
use ssz::Encode;
use state_processing::per_block_processing::{is_execution_enabled, is_merge_block};
use state_processing::{
block_signature_verifier::{BlockSignatureVerifier, Error as BlockSignatureVerifierError},
per_block_processing, per_slot_processing,
state_advance::partial_state_advance,
BlockProcessingError, BlockSignatureStrategy, SlotProcessingError,
};
use std::borrow::Cow;
use std::fs;
use std::io::Write;
use store::{Error as DBError, HotColdDB, HotStateSummary, KeyValueStore, StoreOp};
use tree_hash::TreeHash;
use types::{
BeaconBlockRef, BeaconState, BeaconStateError, ChainSpec, CloneConfig, Epoch, EthSpec,
ExecutionPayload, Hash256, InconsistentFork, PublicKey, PublicKeyBytes, RelativeEpoch,
SignedBeaconBlock, SignedBeaconBlockHeader, Slot,
};
/// Maximum block slot number. Block with slots bigger than this constant will NOT be processed.
const MAXIMUM_BLOCK_SLOT_NUMBER: u64 = 4_294_967_296; // 2^32
/// If true, everytime a block is processed the pre-state, post-state and block are written to SSZ
/// files in the temp directory.
///
/// Only useful for testing.
const WRITE_BLOCK_PROCESSING_SSZ: bool = cfg!(feature = "write_ssz_files");
/// Returned when a block was not verified. A block is not verified for two reasons:
///
/// - The block is malformed/invalid (indicated by all results other than `BeaconChainError`.
/// - We encountered an error whilst trying to verify the block (a `BeaconChainError`).
#[derive(Debug)]
pub enum BlockError<T: EthSpec> {
/// The parent block was unknown.
///
/// ## Peer scoring
///
/// It's unclear if this block is valid, but it cannot be processed without already knowing
/// its parent.
ParentUnknown(Box<SignedBeaconBlock<T>>),
/// The block skips too many slots and is a DoS risk.
TooManySkippedSlots { parent_slot: Slot, block_slot: Slot },
/// The block slot is greater than the present slot.
///
/// ## Peer scoring
///
/// Assuming the local clock is correct, the peer has sent an invalid message.
FutureSlot {
present_slot: Slot,
block_slot: Slot,
},
/// The block state_root does not match the generated state.
///
/// ## Peer scoring
///
/// The peer has incompatible state transition logic and is faulty.
StateRootMismatch { block: Hash256, local: Hash256 },
/// The block was a genesis block, these blocks cannot be re-imported.
GenesisBlock,
/// The slot is finalized, no need to import.
///
/// ## Peer scoring
///
/// It's unclear if this block is valid, but this block is for a finalized slot and is
/// therefore useless to us.
WouldRevertFinalizedSlot {
block_slot: Slot,
finalized_slot: Slot,
},
/// The block conflicts with finalization, no need to propagate.
///
/// ## Peer scoring
///
/// It's unclear if this block is valid, but it conflicts with finality and shouldn't be
/// imported.
NotFinalizedDescendant { block_parent_root: Hash256 },
/// Block is already known, no need to re-import.
///
/// ## Peer scoring
///
/// The block is valid and we have already imported a block with this hash.
BlockIsAlreadyKnown,
/// A block for this proposer and slot has already been observed.
///
/// ## Peer scoring
///
/// The `proposer` has already proposed a block at this slot. The existing block may or may not
/// be equal to the given block.
RepeatProposal { proposer: u64, slot: Slot },
/// The block slot exceeds the MAXIMUM_BLOCK_SLOT_NUMBER.
///
/// ## Peer scoring
///
/// We set a very, very high maximum slot number and this block exceeds it. There's no good
/// reason to be sending these blocks, they're from future slots.
///
/// The block is invalid and the peer is faulty.
BlockSlotLimitReached,
/// The `BeaconBlock` has a `proposer_index` that does not match the index we computed locally.
///
/// ## Peer scoring
///
/// The block is invalid and the peer is faulty.
IncorrectBlockProposer { block: u64, local_shuffling: u64 },
/// The proposal signature in invalid.
///
/// ## Peer scoring
///
/// The block is invalid and the peer is faulty.
ProposalSignatureInvalid,
/// The `block.proposal_index` is not known.
///
/// ## Peer scoring
///
/// The block is invalid and the peer is faulty.
UnknownValidator(u64),
/// A signature in the block is invalid (exactly which is unknown).
///
/// ## Peer scoring
///
/// The block is invalid and the peer is faulty.
InvalidSignature,
/// The provided block is from an later slot than its parent.
///
/// ## Peer scoring
///
/// The block is invalid and the peer is faulty.
BlockIsNotLaterThanParent { block_slot: Slot, parent_slot: Slot },
/// At least one block in the chain segment did not have it's parent root set to the root of
/// the prior block.
///
/// ## Peer scoring
///
/// The chain of blocks is invalid and the peer is faulty.
NonLinearParentRoots,
/// The slots of the blocks in the chain segment were not strictly increasing. I.e., a child
/// had lower slot than a parent.
///
/// ## Peer scoring
///
/// The chain of blocks is invalid and the peer is faulty.
NonLinearSlots,
/// The block failed the specification's `per_block_processing` function, it is invalid.
///
/// ## Peer scoring
///
/// The block is invalid and the peer is faulty.
PerBlockProcessingError(BlockProcessingError),
/// There was an error whilst processing the block. It is not necessarily invalid.
///
/// ## Peer scoring
///
/// We were unable to process this block due to an internal error. It's unclear if the block is
/// valid.
BeaconChainError(BeaconChainError),
/// There was an error whilst verifying weak subjectivity. This block conflicts with the
/// configured weak subjectivity checkpoint and was not imported.
///
/// ## Peer scoring
///
/// The block is invalid and the peer is faulty.
WeakSubjectivityConflict,
/// The block has the wrong structure for the fork at `block.slot`.
///
/// ## Peer scoring
///
/// The block is invalid and the peer is faulty.
InconsistentFork(InconsistentFork),
/// There was an error while validating the ExecutionPayload
///
/// ## Peer scoring
///
/// See `ExecutionPayloadError` for scoring information
ExecutionPayloadError(ExecutionPayloadError),
}
/// Returned when block validation failed due to some issue verifying
/// the execution payload.
#[derive(Debug)]
pub enum ExecutionPayloadError {
/// There's no eth1 connection (mandatory after merge)
///
/// ## Peer scoring
///
/// As this is our fault, do not penalize the peer
NoExecutionConnection,
/// Error occurred during engine_executePayload
///
/// ## Peer scoring
///
/// Some issue with our configuration, do not penalize peer
RequestFailed(execution_layer::Error),
/// The execution engine returned INVALID for the payload
///
/// ## Peer scoring
///
/// The block is invalid and the peer is faulty
RejectedByExecutionEngine,
/// The execution engine returned SYNCING for the payload
///
/// ## Peer scoring
///
/// It is not known if the block is valid or invalid.
ExecutionEngineIsSyncing,
/// The execution payload timestamp does not match the slot
///
/// ## Peer scoring
///
/// The block is invalid and the peer is faulty
InvalidPayloadTimestamp { expected: u64, found: u64 },
/// The gas used in the block exceeds the gas limit
///
/// ## Peer scoring
///
/// The block is invalid and the peer is faulty
GasUsedExceedsLimit,
/// The payload block hash equals the parent hash
///
/// ## Peer scoring
///
/// The block is invalid and the peer is faulty
BlockHashEqualsParentHash,
/// The execution payload transaction list data exceeds size limits
///
/// ## Peer scoring
///
/// The block is invalid and the peer is faulty
TransactionDataExceedsSizeLimit,
/// The execution payload references an execution block that cannot trigger the merge.
///
/// ## Peer scoring
///
/// The block is invalid and the peer sent us a block that passes gossip propagation conditions,
/// but is invalid upon further verification.
InvalidTerminalPoWBlock,
/// The execution payload references execution blocks that are unavailable on our execution
/// nodes.
///
/// ## Peer scoring
///
/// It's not clear if the peer is invalid or if it's on a different execution fork to us.
TerminalPoWBlockNotFound,
}
impl From<execution_layer::Error> for ExecutionPayloadError {
fn from(e: execution_layer::Error) -> Self {
ExecutionPayloadError::RequestFailed(e)
}
}
impl<T: EthSpec> From<ExecutionPayloadError> for BlockError<T> {
fn from(e: ExecutionPayloadError) -> Self {
BlockError::ExecutionPayloadError(e)
}
}
impl<T: EthSpec> From<InconsistentFork> for BlockError<T> {
fn from(e: InconsistentFork) -> Self {
BlockError::InconsistentFork(e)
}
}
impl<T: EthSpec> std::fmt::Display for BlockError<T> {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
match self {
BlockError::ParentUnknown(block) => {
write!(f, "ParentUnknown(parent_root:{})", block.parent_root())
}
other => write!(f, "{:?}", other),
}
}
}
impl<T: EthSpec> From<BlockSignatureVerifierError> for BlockError<T> {
fn from(e: BlockSignatureVerifierError) -> Self {
match e {
// Make a special distinction for `IncorrectBlockProposer` since it indicates an
// invalid block, not an internal error.
BlockSignatureVerifierError::IncorrectBlockProposer {
block,
local_shuffling,
} => BlockError::IncorrectBlockProposer {
block,
local_shuffling,
},
e => BlockError::BeaconChainError(BeaconChainError::BlockSignatureVerifierError(e)),
}
}
}
impl<T: EthSpec> From<BeaconChainError> for BlockError<T> {
fn from(e: BeaconChainError) -> Self {
BlockError::BeaconChainError(e)
}
}
impl<T: EthSpec> From<BeaconStateError> for BlockError<T> {
fn from(e: BeaconStateError) -> Self {
BlockError::BeaconChainError(BeaconChainError::BeaconStateError(e))
}
}
impl<T: EthSpec> From<SlotProcessingError> for BlockError<T> {
fn from(e: SlotProcessingError) -> Self {
BlockError::BeaconChainError(BeaconChainError::SlotProcessingError(e))
}
}
impl<T: EthSpec> From<DBError> for BlockError<T> {
fn from(e: DBError) -> Self {
BlockError::BeaconChainError(BeaconChainError::DBError(e))
}
}
impl<T: EthSpec> From<ArithError> for BlockError<T> {
fn from(e: ArithError) -> Self {
BlockError::BeaconChainError(BeaconChainError::ArithError(e))
}
}
/// Information about invalid blocks which might still be slashable despite being invalid.
#[allow(clippy::enum_variant_names)]
pub enum BlockSlashInfo<TErr> {
/// The block is invalid, but its proposer signature wasn't checked.
SignatureNotChecked(SignedBeaconBlockHeader, TErr),
/// The block's proposer signature is invalid, so it will never be slashable.
SignatureInvalid(TErr),
/// The signature is valid but the attestation is invalid in some other way.
SignatureValid(SignedBeaconBlockHeader, TErr),
}
impl<E: EthSpec> BlockSlashInfo<BlockError<E>> {
pub fn from_early_error(header: SignedBeaconBlockHeader, e: BlockError<E>) -> Self {
match e {
BlockError::ProposalSignatureInvalid => BlockSlashInfo::SignatureInvalid(e),
// `InvalidSignature` could indicate any signature in the block, so we want
// to recheck the proposer signature alone.
_ => BlockSlashInfo::SignatureNotChecked(header, e),
}
}
}
/// Process invalid blocks to see if they are suitable for the slasher.
///
/// If no slasher is configured, this is a no-op.
fn process_block_slash_info<T: BeaconChainTypes>(
chain: &BeaconChain<T>,
slash_info: BlockSlashInfo<BlockError<T::EthSpec>>,
) -> BlockError<T::EthSpec> {
if let Some(slasher) = chain.slasher.as_ref() {
let (verified_header, error) = match slash_info {
BlockSlashInfo::SignatureNotChecked(header, e) => {
if verify_header_signature(chain, &header).is_ok() {
(header, e)
} else {
return e;
}
}
BlockSlashInfo::SignatureInvalid(e) => return e,
BlockSlashInfo::SignatureValid(header, e) => (header, e),
};
slasher.accept_block_header(verified_header);
error
} else {
match slash_info {
BlockSlashInfo::SignatureNotChecked(_, e)
| BlockSlashInfo::SignatureInvalid(e)
| BlockSlashInfo::SignatureValid(_, e) => e,
}
}
}
/// Verify all signatures (except deposit signatures) on all blocks in the `chain_segment`. If all
/// signatures are valid, the `chain_segment` is mapped to a `Vec<SignatureVerifiedBlock>` that can
/// later be transformed into a `FullyVerifiedBlock` without re-checking the signatures. If any
/// signature in the block is invalid, an `Err` is returned (it is not possible to known _which_
/// signature was invalid).
///
/// ## Errors
///
/// The given `chain_segment` must span no more than two epochs, otherwise an error will be
/// returned.
pub fn signature_verify_chain_segment<T: BeaconChainTypes>(
mut chain_segment: Vec<(Hash256, SignedBeaconBlock<T::EthSpec>)>,
chain: &BeaconChain<T>,
) -> Result<Vec<SignatureVerifiedBlock<T>>, BlockError<T::EthSpec>> {
if chain_segment.is_empty() {
return Ok(vec![]);
}
let (first_root, first_block) = chain_segment.remove(0);
let (mut parent, first_block) = load_parent(first_block, chain)?;
let slot = first_block.slot();
chain_segment.insert(0, (first_root, first_block));
let highest_slot = chain_segment
.last()
.map(|(_, block)| block.slot())
.unwrap_or_else(|| slot);
let state = cheap_state_advance_to_obtain_committees(
&mut parent.pre_state,
parent.beacon_state_root,
highest_slot,
&chain.spec,
)?;
let pubkey_cache = get_validator_pubkey_cache(chain)?;
let mut signature_verifier = get_signature_verifier(&state, &pubkey_cache, &chain.spec);
for (block_root, block) in &chain_segment {
signature_verifier.include_all_signatures(block, Some(*block_root))?;
}
if signature_verifier.verify().is_err() {
return Err(BlockError::InvalidSignature);
}
drop(pubkey_cache);
let mut signature_verified_blocks = chain_segment
.into_iter()
.map(|(block_root, block)| SignatureVerifiedBlock {
block,
block_root,
parent: None,
})
.collect::<Vec<_>>();
if let Some(signature_verified_block) = signature_verified_blocks.first_mut() {
signature_verified_block.parent = Some(parent);
}
Ok(signature_verified_blocks)
}
/// A wrapper around a `SignedBeaconBlock` that indicates it has been approved for re-gossiping on
/// the p2p network.
#[derive(Debug)]
pub struct GossipVerifiedBlock<T: BeaconChainTypes> {
pub block: SignedBeaconBlock<T::EthSpec>,
pub block_root: Hash256,
parent: Option<PreProcessingSnapshot<T::EthSpec>>,
}
/// A wrapper around a `SignedBeaconBlock` that indicates that all signatures (except the deposit
/// signatures) have been verified.
pub struct SignatureVerifiedBlock<T: BeaconChainTypes> {
block: SignedBeaconBlock<T::EthSpec>,
block_root: Hash256,
parent: Option<PreProcessingSnapshot<T::EthSpec>>,
}
/// A wrapper around a `SignedBeaconBlock` that indicates that this block is fully verified and
/// ready to import into the `BeaconChain`. The validation includes:
///
/// - Parent is known
/// - Signatures
/// - State root check
/// - Per block processing
///
/// Note: a `FullyVerifiedBlock` is not _forever_ valid to be imported, it may later become invalid
/// due to finality or some other event. A `FullyVerifiedBlock` should be imported into the
/// `BeaconChain` immediately after it is instantiated.
pub struct FullyVerifiedBlock<'a, T: BeaconChainTypes> {
pub block: SignedBeaconBlock<T::EthSpec>,
pub block_root: Hash256,
pub state: BeaconState<T::EthSpec>,
pub parent_block: SignedBeaconBlock<T::EthSpec>,
pub confirmation_db_batch: Vec<StoreOp<'a, T::EthSpec>>,
}
/// Implemented on types that can be converted into a `FullyVerifiedBlock`.
///
/// Used to allow functions to accept blocks at various stages of verification.
pub trait IntoFullyVerifiedBlock<T: BeaconChainTypes>: Sized {
fn into_fully_verified_block(
self,
chain: &BeaconChain<T>,
) -> Result<FullyVerifiedBlock<T>, BlockError<T::EthSpec>> {
self.into_fully_verified_block_slashable(chain)
.map(|fully_verified| {
// Supply valid block to slasher.
if let Some(slasher) = chain.slasher.as_ref() {
slasher.accept_block_header(fully_verified.block.signed_block_header());
}
fully_verified
})
.map_err(|slash_info| process_block_slash_info(chain, slash_info))
}
/// Convert the block to fully-verified form while producing data to aid checking slashability.
fn into_fully_verified_block_slashable(
self,
chain: &BeaconChain<T>,
) -> Result<FullyVerifiedBlock<T>, BlockSlashInfo<BlockError<T::EthSpec>>>;
fn block(&self) -> &SignedBeaconBlock<T::EthSpec>;
}
impl<T: BeaconChainTypes> GossipVerifiedBlock<T> {
/// Instantiates `Self`, a wrapper that indicates the given `block` is safe to be re-gossiped
/// on the p2p network.
///
/// Returns an error if the block is invalid, or if the block was unable to be verified.
pub fn new(
block: SignedBeaconBlock<T::EthSpec>,
chain: &BeaconChain<T>,
) -> Result<Self, BlockError<T::EthSpec>> {
// If the block is valid for gossip we don't supply it to the slasher here because
// we assume it will be transformed into a fully verified block. We *do* need to supply
// it to the slasher if an error occurs, because that's the end of this block's journey,
// and it could be a repeat proposal (a likely cause for slashing!).
let header = block.signed_block_header();
Self::new_without_slasher_checks(block, chain).map_err(|e| {
process_block_slash_info(chain, BlockSlashInfo::from_early_error(header, e))
})
}
/// As for new, but doesn't pass the block to the slasher.
fn new_without_slasher_checks(
block: SignedBeaconBlock<T::EthSpec>,
chain: &BeaconChain<T>,
) -> Result<Self, BlockError<T::EthSpec>> {
// Ensure the block is the correct structure for the fork at `block.slot()`.
block
.fork_name(&chain.spec)
.map_err(BlockError::InconsistentFork)?;
// Do not gossip or process blocks from future slots.
let present_slot_with_tolerance = chain
.slot_clock
.now_with_future_tolerance(MAXIMUM_GOSSIP_CLOCK_DISPARITY)
.ok_or(BeaconChainError::UnableToReadSlot)?;
if block.slot() > present_slot_with_tolerance {
return Err(BlockError::FutureSlot {
present_slot: present_slot_with_tolerance,
block_slot: block.slot(),
});
}
let block_root = get_block_root(&block);
// Disallow blocks that conflict with the anchor (weak subjectivity checkpoint), if any.
check_block_against_anchor_slot(block.message(), chain)?;
// Do not gossip a block from a finalized slot.
check_block_against_finalized_slot(block.message(), chain)?;
// Check if the block is already known. We know it is post-finalization, so it is
// sufficient to check the fork choice.
//
// In normal operation this isn't necessary, however it is useful immediately after a
// reboot if the `observed_block_producers` cache is empty. In that case, without this
// check, we will load the parent and state from disk only to find out later that we
// already know this block.
if chain.fork_choice.read().contains_block(&block_root) {
return Err(BlockError::BlockIsAlreadyKnown);
}
// Check that we have not already received a block with a valid signature for this slot.
if chain
.observed_block_producers
.read()
.proposer_has_been_observed(block.message())
.map_err(|e| BlockError::BeaconChainError(e.into()))?
{
return Err(BlockError::RepeatProposal {
proposer: block.message().proposer_index(),
slot: block.slot(),
});
}
// Do not process a block that doesn't descend from the finalized root.
//
// We check this *before* we load the parent so that we can return a more detailed error.
let block = check_block_is_finalized_descendant::<T, _>(
block,
&chain.fork_choice.read(),
&chain.store,
)?;
let block_epoch = block.slot().epoch(T::EthSpec::slots_per_epoch());
let (parent_block, block) = verify_parent_block_is_known(chain, block)?;
// Track the number of skip slots between the block and its parent.
metrics::set_gauge(
&metrics::GOSSIP_BEACON_BLOCK_SKIPPED_SLOTS,
block
.slot()
.as_u64()
.saturating_sub(1)
.saturating_sub(parent_block.slot.into()) as i64,
);
// Paranoid check to prevent propagation of blocks that don't form a legitimate chain.
//
// This is not in the spec, but @protolambda tells me that the majority of other clients are
// already doing it. For reference:
//
// https://github.com/ethereum/eth2.0-specs/pull/2196
if parent_block.slot >= block.slot() {
return Err(BlockError::BlockIsNotLaterThanParent {
block_slot: block.slot(),
parent_slot: parent_block.slot,
});
}
let proposer_shuffling_decision_block =
if parent_block.slot.epoch(T::EthSpec::slots_per_epoch()) == block_epoch {
parent_block
.next_epoch_shuffling_id
.shuffling_decision_block
} else {
parent_block.root
};
// Reject any block that exceeds our limit on skipped slots.
check_block_skip_slots(chain, parent_block.slot, block.message())?;
// We assign to a variable instead of using `if let Some` directly to ensure we drop the
// write lock before trying to acquire it again in the `else` clause.
let proposer_opt = chain
.beacon_proposer_cache
.lock()
.get_slot::<T::EthSpec>(proposer_shuffling_decision_block, block.slot());
let (expected_proposer, fork, parent, block) = if let Some(proposer) = proposer_opt {
// The proposer index was cached and we can return it without needing to load the
// parent.
(proposer.index, proposer.fork, None, block)
} else {
// The proposer index was *not* cached and we must load the parent in order to determine
// the proposer index.
let (mut parent, block) = load_parent(block, chain)?;
debug!(
chain.log,
"Proposer shuffling cache miss";
"parent_root" => ?parent.beacon_block_root,
"parent_slot" => parent.beacon_block.slot(),
"block_root" => ?block_root,
"block_slot" => block.slot(),
);
// The state produced is only valid for determining proposer/attester shuffling indices.
let state = cheap_state_advance_to_obtain_committees(
&mut parent.pre_state,
parent.beacon_state_root,
block.slot(),
&chain.spec,
)?;
let proposers = state.get_beacon_proposer_indices(&chain.spec)?;
let proposer_index = *proposers
.get(block.slot().as_usize() % T::EthSpec::slots_per_epoch() as usize)
.ok_or_else(|| BeaconChainError::NoProposerForSlot(block.slot()))?;
// Prime the proposer shuffling cache with the newly-learned value.
chain.beacon_proposer_cache.lock().insert(
block_epoch,
proposer_shuffling_decision_block,
proposers,
state.fork(),
)?;
(proposer_index, state.fork(), Some(parent), block)
};
let signature_is_valid = {
let pubkey_cache = get_validator_pubkey_cache(chain)?;
let pubkey = pubkey_cache
.get(block.message().proposer_index() as usize)
.ok_or_else(|| BlockError::UnknownValidator(block.message().proposer_index()))?;
block.verify_signature(
Some(block_root),
pubkey,
&fork,
chain.genesis_validators_root,
&chain.spec,
)
};
if !signature_is_valid {
return Err(BlockError::ProposalSignatureInvalid);
}
// Now the signature is valid, store the proposal so we don't accept another from this
// validator and slot.
//
// It's important to double-check that the proposer still hasn't been observed so we don't
// have a race-condition when verifying two blocks simultaneously.
if chain
.observed_block_producers
.write()
.observe_proposer(block.message())
.map_err(|e| BlockError::BeaconChainError(e.into()))?
{
return Err(BlockError::RepeatProposal {
proposer: block.message().proposer_index(),
slot: block.slot(),
});
}
if block.message().proposer_index() != expected_proposer as u64 {
return Err(BlockError::IncorrectBlockProposer {
block: block.message().proposer_index(),
local_shuffling: expected_proposer as u64,
});
}
// validate the block's execution_payload
validate_execution_payload(&parent_block, block.message(), chain)?;
Ok(Self {
block,
block_root,
parent,
})
}
pub fn block_root(&self) -> Hash256 {
self.block_root
}
}
impl<T: BeaconChainTypes> IntoFullyVerifiedBlock<T> for GossipVerifiedBlock<T> {
/// Completes verification of the wrapped `block`.
fn into_fully_verified_block_slashable(
self,
chain: &BeaconChain<T>,
) -> Result<FullyVerifiedBlock<T>, BlockSlashInfo<BlockError<T::EthSpec>>> {
let fully_verified =
SignatureVerifiedBlock::from_gossip_verified_block_check_slashable(self, chain)?;
fully_verified.into_fully_verified_block_slashable(chain)
}
fn block(&self) -> &SignedBeaconBlock<T::EthSpec> {
&self.block
}
}
impl<T: BeaconChainTypes> SignatureVerifiedBlock<T> {
/// Instantiates `Self`, a wrapper that indicates that all signatures (except the deposit
/// signatures) are valid (i.e., signed by the correct public keys).
///
/// Returns an error if the block is invalid, or if the block was unable to be verified.
pub fn new(
block: SignedBeaconBlock<T::EthSpec>,
block_root: Hash256,
chain: &BeaconChain<T>,
) -> Result<Self, BlockError<T::EthSpec>> {
// Ensure the block is the correct structure for the fork at `block.slot()`.
block
.fork_name(&chain.spec)
.map_err(BlockError::InconsistentFork)?;
// Check the anchor slot before loading the parent, to avoid spurious lookups.
check_block_against_anchor_slot(block.message(), chain)?;
let (mut parent, block) = load_parent(block, chain)?;
// Reject any block that exceeds our limit on skipped slots.
check_block_skip_slots(chain, parent.beacon_block.slot(), block.message())?;
let state = cheap_state_advance_to_obtain_committees(
&mut parent.pre_state,
parent.beacon_state_root,
block.slot(),
&chain.spec,
)?;
let pubkey_cache = get_validator_pubkey_cache(chain)?;
let mut signature_verifier = get_signature_verifier(&state, &pubkey_cache, &chain.spec);
signature_verifier.include_all_signatures(&block, Some(block_root))?;
if signature_verifier.verify().is_ok() {
Ok(Self {
block,
block_root,
parent: Some(parent),
})
} else {
Err(BlockError::InvalidSignature)
}
}
/// As for `new` above but producing `BlockSlashInfo`.
pub fn check_slashable(
block: SignedBeaconBlock<T::EthSpec>,
block_root: Hash256,
chain: &BeaconChain<T>,
) -> Result<Self, BlockSlashInfo<BlockError<T::EthSpec>>> {
let header = block.signed_block_header();
Self::new(block, block_root, chain).map_err(|e| BlockSlashInfo::from_early_error(header, e))
}
/// Finishes signature verification on the provided `GossipVerifedBlock`. Does not re-verify
/// the proposer signature.
pub fn from_gossip_verified_block(
from: GossipVerifiedBlock<T>,
chain: &BeaconChain<T>,
) -> Result<Self, BlockError<T::EthSpec>> {
let (mut parent, block) = if let Some(parent) = from.parent {
(parent, from.block)
} else {
load_parent(from.block, chain)?
};
let state = cheap_state_advance_to_obtain_committees(
&mut parent.pre_state,
parent.beacon_state_root,
block.slot(),
&chain.spec,
)?;
let pubkey_cache = get_validator_pubkey_cache(chain)?;
let mut signature_verifier = get_signature_verifier(&state, &pubkey_cache, &chain.spec);
signature_verifier.include_all_signatures_except_proposal(&block)?;
if signature_verifier.verify().is_ok() {
Ok(Self {
block,
block_root: from.block_root,
parent: Some(parent),
})
} else {
Err(BlockError::InvalidSignature)
}
}
/// Same as `from_gossip_verified_block` but producing slashing-relevant data as well.
pub fn from_gossip_verified_block_check_slashable(
from: GossipVerifiedBlock<T>,
chain: &BeaconChain<T>,
) -> Result<Self, BlockSlashInfo<BlockError<T::EthSpec>>> {
let header = from.block.signed_block_header();
Self::from_gossip_verified_block(from, chain)
.map_err(|e| BlockSlashInfo::from_early_error(header, e))
}
}
impl<T: BeaconChainTypes> IntoFullyVerifiedBlock<T> for SignatureVerifiedBlock<T> {
/// Completes verification of the wrapped `block`.
fn into_fully_verified_block_slashable(
self,
chain: &BeaconChain<T>,
) -> Result<FullyVerifiedBlock<T>, BlockSlashInfo<BlockError<T::EthSpec>>> {
let header = self.block.signed_block_header();
let (parent, block) = if let Some(parent) = self.parent {
(parent, self.block)
} else {
load_parent(self.block, chain)
.map_err(|e| BlockSlashInfo::SignatureValid(header.clone(), e))?
};
FullyVerifiedBlock::from_signature_verified_components(
block,
self.block_root,
parent,
chain,
)
.map_err(|e| BlockSlashInfo::SignatureValid(header, e))
}
fn block(&self) -> &SignedBeaconBlock<T::EthSpec> {
&self.block
}
}
impl<T: BeaconChainTypes> IntoFullyVerifiedBlock<T> for SignedBeaconBlock<T::EthSpec> {
/// Verifies the `SignedBeaconBlock` by first transforming it into a `SignatureVerifiedBlock`
/// and then using that implementation of `IntoFullyVerifiedBlock` to complete verification.
fn into_fully_verified_block_slashable(
self,
chain: &BeaconChain<T>,
) -> Result<FullyVerifiedBlock<T>, BlockSlashInfo<BlockError<T::EthSpec>>> {
// Perform an early check to prevent wasting time on irrelevant blocks.
let block_root = check_block_relevancy(&self, None, chain)
.map_err(|e| BlockSlashInfo::SignatureNotChecked(self.signed_block_header(), e))?;
SignatureVerifiedBlock::check_slashable(self, block_root, chain)?
.into_fully_verified_block_slashable(chain)
}
fn block(&self) -> &SignedBeaconBlock<T::EthSpec> {
self
}
}
impl<'a, T: BeaconChainTypes> FullyVerifiedBlock<'a, T> {
/// Instantiates `Self`, a wrapper that indicates that the given `block` is fully valid. See
/// the struct-level documentation for more information.
///
/// Note: this function does not verify block signatures, it assumes they are valid. Signature
/// verification must be done upstream (e.g., via a `SignatureVerifiedBlock`
///
/// Returns an error if the block is invalid, or if the block was unable to be verified.
pub fn from_signature_verified_components(
block: SignedBeaconBlock<T::EthSpec>,
block_root: Hash256,
parent: PreProcessingSnapshot<T::EthSpec>,
chain: &BeaconChain<T>,
) -> Result<Self, BlockError<T::EthSpec>> {
// Reject any block if its parent is not known to fork choice.
//
// A block that is not in fork choice is either:
//
// - Not yet imported: we should reject this block because we should only import a child
// after its parent has been fully imported.
// - Pre-finalized: if the parent block is _prior_ to finalization, we should ignore it
// because it will revert finalization. Note that the finalized block is stored in fork
// choice, so we will not reject any child of the finalized block (this is relevant during
// genesis).
if !chain
.fork_choice
.read()
.contains_block(&block.parent_root())
{
return Err(BlockError::ParentUnknown(Box::new(block)));
}
// Reject any block that exceeds our limit on skipped slots.
check_block_skip_slots(chain, parent.beacon_block.slot(), block.message())?;
/*
* Perform cursory checks to see if the block is even worth processing.
*/
check_block_relevancy(&block, Some(block_root), chain)?;
/*
* Advance the given `parent.beacon_state` to the slot of the given `block`.
*/
let catchup_timer = metrics::start_timer(&metrics::BLOCK_PROCESSING_CATCHUP_STATE);
// Stage a batch of operations to be completed atomically if this block is imported
// successfully.
let mut confirmation_db_batch = vec![];
// The block must have a higher slot than its parent.
if block.slot() <= parent.beacon_block.slot() {
return Err(BlockError::BlockIsNotLaterThanParent {
block_slot: block.slot(),
parent_slot: parent.beacon_block.slot(),
});
}
let mut summaries = vec![];
// Transition the parent state to the block slot.
//
// It is important to note that we're using a "pre-state" here, one that has potentially
// been advanced one slot forward from `parent.beacon_block.slot`.
let mut state = parent.pre_state;
// Perform a sanity check on the pre-state.
let parent_slot = parent.beacon_block.slot();
if state.slot() < parent_slot || state.slot() > parent_slot + 1 {
return Err(BeaconChainError::BadPreState {
parent_root: parent.beacon_block_root,
parent_slot,
block_root,
block_slot: block.slot(),
state_slot: state.slot(),
}
.into());
}
let distance = block.slot().as_u64().saturating_sub(state.slot().as_u64());
for _ in 0..distance {
let state_root = if parent.beacon_block.slot() == state.slot() {
// If it happens that `pre_state` has *not* already been advanced forward a single
// slot, then there is no need to compute the state root for this
// `per_slot_processing` call since that state root is already stored in the parent
// block.
parent.beacon_block.state_root()
} else {
// This is a new state we've reached, so stage it for storage in the DB.
// Computing the state root here is time-equivalent to computing it during slot
// processing, but we get early access to it.
let state_root = state.update_tree_hash_cache()?;
// Store the state immediately, marking it as temporary, and staging the deletion
// of its temporary status as part of the larger atomic operation.
let txn_lock = chain.store.hot_db.begin_rw_transaction();
let state_already_exists =
chain.store.load_hot_state_summary(&state_root)?.is_some();
let state_batch = if state_already_exists {
// If the state exists, it could be temporary or permanent, but in neither case
// should we rewrite it or store a new temporary flag for it. We *will* stage
// the temporary flag for deletion because it's OK to double-delete the flag,
// and we don't mind if another thread gets there first.
vec![]
} else {
vec![
if state.slot() % T::EthSpec::slots_per_epoch() == 0 {
StoreOp::PutState(state_root, &state)
} else {
StoreOp::PutStateSummary(
state_root,
HotStateSummary::new(&state_root, &state)?,
)
},
StoreOp::PutStateTemporaryFlag(state_root),
]
};
chain.store.do_atomically(state_batch)?;
drop(txn_lock);
confirmation_db_batch.push(StoreOp::DeleteStateTemporaryFlag(state_root));
state_root
};
if let Some(summary) = per_slot_processing(&mut state, Some(state_root), &chain.spec)? {
// Expose Prometheus metrics.
if let Err(e) = summary.observe_metrics() {
error!(
chain.log,
"Failed to observe epoch summary metrics";
"src" => "block_verification",
"error" => ?e
);
}
summaries.push(summary);
}
}
// If this block triggers the merge, check to ensure that it references valid execution
// blocks.
//
// The specification defines this check inside `on_block` in the fork-choice specification,
// however we perform the check here for two reasons:
//
// - There's no point in importing a block that will fail fork choice, so it's best to fail
// early.
// - Doing the check here means we can keep our fork-choice implementation "pure". I.e., no
// calls to remote servers.
if is_merge_block(&state, block.message().body()) {
let execution_layer = chain
.execution_layer
.as_ref()
.ok_or(ExecutionPayloadError::NoExecutionConnection)?;
let execution_payload =
block
.message()
.body()
.execution_payload()
.ok_or_else(|| InconsistentFork {
fork_at_slot: eth2::types::ForkName::Merge,
object_fork: block.message().body().fork_name(),
})?;
let is_valid_terminal_pow_block = execution_layer
.block_on(|execution_layer| {
execution_layer.is_valid_terminal_pow_block_hash(execution_payload.parent_hash)
})
.map_err(ExecutionPayloadError::from)?;
match is_valid_terminal_pow_block {
Some(true) => Ok(()),
Some(false) => Err(ExecutionPayloadError::InvalidTerminalPoWBlock),
None => {
info!(
chain.log,
"Optimistically accepting terminal block";
"block_hash" => ?execution_payload.parent_hash,
"msg" => "the terminal block/parent was unavailable"
);
Ok(())
}
}?;
}
// This is the soonest we can run these checks as they must be called AFTER per_slot_processing
let execute_payload_handle = if is_execution_enabled(&state, block.message().body()) {
let execution_layer = chain
.execution_layer
.as_ref()
.ok_or(ExecutionPayloadError::NoExecutionConnection)?;
let execution_payload =
block
.message()
.body()
.execution_payload()
.ok_or_else(|| InconsistentFork {
fork_at_slot: eth2::types::ForkName::Merge,
object_fork: block.message().body().fork_name(),
})?;
let execute_payload_response = execution_layer
.block_on(|execution_layer| execution_layer.execute_payload(execution_payload));
match execute_payload_response {
Ok((status, handle)) => match status {
ExecutePayloadResponse::Valid => handle,
ExecutePayloadResponse::Invalid => {
return Err(ExecutionPayloadError::RejectedByExecutionEngine.into());
}
ExecutePayloadResponse::Syncing => {
debug!(
chain.log,
"Optimistically accepting payload";
"msg" => "execution engine is syncing"
);
handle
}
},
Err(e) => {
error!(
chain.log,
"Optimistically accepting payload";
"error" => ?e,
"msg" => "execution engine returned an error"
);
None
}
}
} else {
None
};
// If the block is sufficiently recent, notify the validator monitor.
if let Some(slot) = chain.slot_clock.now() {
let epoch = slot.epoch(T::EthSpec::slots_per_epoch());
if block.slot().epoch(T::EthSpec::slots_per_epoch())
+ VALIDATOR_MONITOR_HISTORIC_EPOCHS as u64
>= epoch
{
let validator_monitor = chain.validator_monitor.read();
// Update the summaries in a separate loop to `per_slot_processing`. This protects
// the `validator_monitor` lock from being bounced or held for a long time whilst
// performing `per_slot_processing`.
for (i, summary) in summaries.iter().enumerate() {
let epoch = state.current_epoch() - Epoch::from(summaries.len() - i);
if let Err(e) =
validator_monitor.process_validator_statuses(epoch, summary, &chain.spec)
{
error!(
chain.log,
"Failed to process validator statuses";
"error" => ?e
);
}
}
}
}
metrics::stop_timer(catchup_timer);
/*
* Build the committee caches on the state.
*/
let committee_timer = metrics::start_timer(&metrics::BLOCK_PROCESSING_COMMITTEE);
state.build_committee_cache(RelativeEpoch::Previous, &chain.spec)?;
state.build_committee_cache(RelativeEpoch::Current, &chain.spec)?;
metrics::stop_timer(committee_timer);
/*
* Perform `per_block_processing` on the block and state, returning early if the block is
* invalid.
*/
write_state(
&format!("state_pre_block_{}", block_root),
&state,
&chain.log,
);
write_block(&block, block_root, &chain.log);
let core_timer = metrics::start_timer(&metrics::BLOCK_PROCESSING_CORE);
if let Err(err) = per_block_processing(
&mut state,
&block,
Some(block_root),
// Signatures were verified earlier in this function.
BlockSignatureStrategy::NoVerification,
&chain.spec,
) {
match err {
// Capture `BeaconStateError` so that we can easily distinguish between a block
// that's invalid and one that caused an internal error.
BlockProcessingError::BeaconStateError(e) => return Err(e.into()),
other => return Err(BlockError::PerBlockProcessingError(other)),
}
};
metrics::stop_timer(core_timer);
/*
* Calculate the state root of the newly modified state
*/
let state_root_timer = metrics::start_timer(&metrics::BLOCK_PROCESSING_STATE_ROOT);
let state_root = state.update_tree_hash_cache()?;
metrics::stop_timer(state_root_timer);
write_state(
&format!("state_post_block_{}", block_root),
&state,
&chain.log,
);
/*
* Check to ensure the state root on the block matches the one we have calculated.
*/
if block.state_root() != state_root {
return Err(BlockError::StateRootMismatch {
block: block.state_root(),
local: state_root,
});
}
// If this block required an `executePayload` call to the execution node, inform it that the
// block is indeed valid.
//
// If the handle is dropped without explicitly declaring validity, an invalid message will
// be sent to the execution engine.
if let Some(execute_payload_handle) = execute_payload_handle {
execute_payload_handle.publish_consensus_valid();
}
Ok(Self {
block,
block_root,
state,
parent_block: parent.beacon_block,
confirmation_db_batch,
})
}
}
/// Validate the gossip block's execution_payload according to the checks described here:
/// https://github.com/ethereum/consensus-specs/blob/dev/specs/merge/p2p-interface.md#beacon_block
fn validate_execution_payload<T: BeaconChainTypes>(
parent_block: &ProtoBlock,
block: BeaconBlockRef<'_, T::EthSpec>,
chain: &BeaconChain<T>,
) -> Result<(), BlockError<T::EthSpec>> {
// Only apply this validation if this is a merge beacon block.
if let Some(execution_payload) = block.body().execution_payload() {
// This logic should match `is_execution_enabled`. We use only the execution block hash of
// the parent here in order to avoid loading the parent state during gossip verification.
let is_merge_complete = parent_block.execution_block_hash != Hash256::zero();
let is_merge_block =
!is_merge_complete && *execution_payload != <ExecutionPayload<T::EthSpec>>::default();
if !is_merge_block && !is_merge_complete {
return Ok(());
}
let expected_timestamp = chain
.slot_clock
.compute_timestamp_at_slot(block.slot())
.ok_or(BlockError::BeaconChainError(
BeaconChainError::UnableToComputeTimeAtSlot,
))?;
// The block's execution payload timestamp is correct with respect to the slot
if execution_payload.timestamp != expected_timestamp {
return Err(BlockError::ExecutionPayloadError(
ExecutionPayloadError::InvalidPayloadTimestamp {
expected: expected_timestamp,
found: execution_payload.timestamp,
},
));
}
// Gas used is less than the gas limit
if execution_payload.gas_used > execution_payload.gas_limit {
return Err(BlockError::ExecutionPayloadError(
ExecutionPayloadError::GasUsedExceedsLimit,
));
}
// The execution payload block hash is not equal to the parent hash
if execution_payload.block_hash == execution_payload.parent_hash {
return Err(BlockError::ExecutionPayloadError(
ExecutionPayloadError::BlockHashEqualsParentHash,
));
}
// The execution payload transaction list data is within expected size limits
if execution_payload.transactions.len() > T::EthSpec::max_transactions_per_payload() {
return Err(BlockError::ExecutionPayloadError(
ExecutionPayloadError::TransactionDataExceedsSizeLimit,
));
}
}
Ok(())
}
/// Check that the count of skip slots between the block and its parent does not exceed our maximum
/// value.
///
/// Whilst this is not part of the specification, we include this to help prevent us from DoS
/// attacks. In times of dire network circumstance, the user can configure the
/// `import_max_skip_slots` value.
fn check_block_skip_slots<T: BeaconChainTypes>(
chain: &BeaconChain<T>,
parent_slot: Slot,
block: BeaconBlockRef<'_, T::EthSpec>,
) -> Result<(), BlockError<T::EthSpec>> {
// Reject any block that exceeds our limit on skipped slots.
if let Some(max_skip_slots) = chain.config.import_max_skip_slots {
if block.slot() > parent_slot + max_skip_slots {
return Err(BlockError::TooManySkippedSlots {
parent_slot,
block_slot: block.slot(),
});
}
}
Ok(())
}
/// Returns `Ok(())` if the block's slot is greater than the anchor block's slot (if any).
fn check_block_against_anchor_slot<T: BeaconChainTypes>(
block: BeaconBlockRef<'_, T::EthSpec>,
chain: &BeaconChain<T>,
) -> Result<(), BlockError<T::EthSpec>> {
if let Some(anchor_slot) = chain.store.get_anchor_slot() {
if block.slot() <= anchor_slot {
return Err(BlockError::WeakSubjectivityConflict);
}
}
Ok(())
}
/// Returns `Ok(())` if the block is later than the finalized slot on `chain`.
///
/// Returns an error if the block is earlier or equal to the finalized slot, or there was an error
/// verifying that condition.
fn check_block_against_finalized_slot<T: BeaconChainTypes>(
block: BeaconBlockRef<'_, T::EthSpec>,
chain: &BeaconChain<T>,
) -> Result<(), BlockError<T::EthSpec>> {
let finalized_slot = chain
.head_info()?
.finalized_checkpoint
.epoch
.start_slot(T::EthSpec::slots_per_epoch());
if block.slot() <= finalized_slot {
Err(BlockError::WouldRevertFinalizedSlot {
block_slot: block.slot(),
finalized_slot,
})
} else {
Ok(())
}
}
/// Returns `Ok(block)` if the block descends from the finalized root.
pub fn check_block_is_finalized_descendant<T: BeaconChainTypes, F: ForkChoiceStore<T::EthSpec>>(
block: SignedBeaconBlock<T::EthSpec>,
fork_choice: &ForkChoice<F, T::EthSpec>,
store: &HotColdDB<T::EthSpec, T::HotStore, T::ColdStore>,
) -> Result<SignedBeaconBlock<T::EthSpec>, BlockError<T::EthSpec>> {
if fork_choice.is_descendant_of_finalized(block.parent_root()) {
Ok(block)
} else {
// If fork choice does *not* consider the parent to be a descendant of the finalized block,
// then there are two more cases:
//
// 1. We have the parent stored in our database. Because fork-choice has confirmed the
// parent is *not* in our post-finalization DAG, all other blocks must be either
// pre-finalization or conflicting with finalization.
// 2. The parent is unknown to us, we probably want to download it since it might actually
// descend from the finalized root.
if store
.block_exists(&block.parent_root())
.map_err(|e| BlockError::BeaconChainError(e.into()))?
{
Err(BlockError::NotFinalizedDescendant {
block_parent_root: block.parent_root(),
})
} else {
Err(BlockError::ParentUnknown(Box::new(block)))
}
}
}
/// Performs simple, cheap checks to ensure that the block is relevant to be imported.
///
/// `Ok(block_root)` is returned if the block passes these checks and should progress with
/// verification (viz., it is relevant).
///
/// Returns an error if the block fails one of these checks (viz., is not relevant) or an error is
/// experienced whilst attempting to verify.
pub fn check_block_relevancy<T: BeaconChainTypes>(
signed_block: &SignedBeaconBlock<T::EthSpec>,
block_root: Option<Hash256>,
chain: &BeaconChain<T>,
) -> Result<Hash256, BlockError<T::EthSpec>> {
let block = signed_block.message();
// Do not process blocks from the future.
if block.slot() > chain.slot()? {
return Err(BlockError::FutureSlot {
present_slot: chain.slot()?,
block_slot: block.slot(),
});
}
// Do not re-process the genesis block.
if block.slot() == 0 {
return Err(BlockError::GenesisBlock);
}
// This is an artificial (non-spec) restriction that provides some protection from overflow
// abuses.
if block.slot() >= MAXIMUM_BLOCK_SLOT_NUMBER {
return Err(BlockError::BlockSlotLimitReached);
}
// Do not process a block from a finalized slot.
check_block_against_finalized_slot(block, chain)?;
let block_root = block_root.unwrap_or_else(|| get_block_root(signed_block));
// Check if the block is already known. We know it is post-finalization, so it is
// sufficient to check the fork choice.
if chain.fork_choice.read().contains_block(&block_root) {
return Err(BlockError::BlockIsAlreadyKnown);
}
Ok(block_root)
}
/// Returns the canonical root of the given `block`.
///
/// Use this function to ensure that we report the block hashing time Prometheus metric.
pub fn get_block_root<E: EthSpec>(block: &SignedBeaconBlock<E>) -> Hash256 {
let block_root_timer = metrics::start_timer(&metrics::BLOCK_PROCESSING_BLOCK_ROOT);
let block_root = block.canonical_root();
metrics::stop_timer(block_root_timer);
block_root
}
/// Verify the parent of `block` is known, returning some information about the parent block from
/// fork choice.
#[allow(clippy::type_complexity)]
fn verify_parent_block_is_known<T: BeaconChainTypes>(
chain: &BeaconChain<T>,
block: SignedBeaconBlock<T::EthSpec>,
) -> Result<(ProtoBlock, SignedBeaconBlock<T::EthSpec>), BlockError<T::EthSpec>> {
if let Some(proto_block) = chain
.fork_choice
.read()
.get_block(&block.message().parent_root())
{
Ok((proto_block, block))
} else {
Err(BlockError::ParentUnknown(Box::new(block)))
}
}
/// Load the parent snapshot (block and state) of the given `block`.
///
/// Returns `Err(BlockError::ParentUnknown)` if the parent is not found, or if an error occurs
/// whilst attempting the operation.
#[allow(clippy::type_complexity)]
fn load_parent<T: BeaconChainTypes>(
block: SignedBeaconBlock<T::EthSpec>,
chain: &BeaconChain<T>,
) -> Result<
(
PreProcessingSnapshot<T::EthSpec>,
SignedBeaconBlock<T::EthSpec>,
),
BlockError<T::EthSpec>,
> {
// Reject any block if its parent is not known to fork choice.
//
// A block that is not in fork choice is either:
//
// - Not yet imported: we should reject this block because we should only import a child
// after its parent has been fully imported.
// - Pre-finalized: if the parent block is _prior_ to finalization, we should ignore it
// because it will revert finalization. Note that the finalized block is stored in fork
// choice, so we will not reject any child of the finalized block (this is relevant during
// genesis).
if !chain
.fork_choice
.read()
.contains_block(&block.parent_root())
{
return Err(BlockError::ParentUnknown(Box::new(block)));
}
let db_read_timer = metrics::start_timer(&metrics::BLOCK_PROCESSING_DB_READ);
let result = if let Some(snapshot) = chain
.snapshot_cache
.try_write_for(BLOCK_PROCESSING_CACHE_LOCK_TIMEOUT)
.and_then(|mut snapshot_cache| {
snapshot_cache.get_state_for_block_processing(block.parent_root())
}) {
Ok((snapshot.into_pre_state(), block))
} else {
// Load the blocks parent block from the database, returning invalid if that block is not
// found.
//
// We don't return a DBInconsistent error here since it's possible for a block to
// exist in fork choice but not in the database yet. In such a case we simply
// indicate that we don't yet know the parent.
let root = block.parent_root();
let parent_block = chain
.get_block(&block.parent_root())
.map_err(BlockError::BeaconChainError)?
.ok_or_else(|| {
// Return a `MissingBeaconBlock` error instead of a `ParentUnknown` error since
// we've already checked fork choice for this block.
//
// It's an internal error if the block exists in fork choice but not in the
// database.
BlockError::from(BeaconChainError::MissingBeaconBlock(block.parent_root()))
})?;
// Load the parent blocks state from the database, returning an error if it is not found.
// It is an error because if we know the parent block we should also know the parent state.
let parent_state_root = parent_block.state_root();
let parent_state = chain
.get_state(&parent_state_root, Some(parent_block.slot()))?
.ok_or_else(|| {
BeaconChainError::DBInconsistent(format!("Missing state {:?}", parent_state_root))
})?;
Ok((
PreProcessingSnapshot {
beacon_block: parent_block,
beacon_block_root: root,
pre_state: parent_state,
beacon_state_root: Some(parent_state_root),
},
block,
))
};
metrics::stop_timer(db_read_timer);
result
}
/// Performs a cheap (time-efficient) state advancement so the committees and proposer shuffling for
/// `slot` can be obtained from `state`.
///
/// The state advancement is "cheap" since it does not generate state roots. As a result, the
/// returned state might be holistically invalid but the committees/proposers will be correct (since
/// they do not rely upon state roots).
///
/// If the given `state` can already serve the `slot`, the committees will be built on the `state`
/// and `Cow::Borrowed(state)` will be returned. Otherwise, the state will be cloned, cheaply
/// advanced and then returned as a `Cow::Owned`. The end result is that the given `state` is never
/// mutated to be invalid (in fact, it is never changed beyond a simple committee cache build).
fn cheap_state_advance_to_obtain_committees<'a, E: EthSpec>(
state: &'a mut BeaconState<E>,
state_root_opt: Option<Hash256>,
block_slot: Slot,
spec: &ChainSpec,
) -> Result<Cow<'a, BeaconState<E>>, BlockError<E>> {
let block_epoch = block_slot.epoch(E::slots_per_epoch());
if state.current_epoch() == block_epoch {
state.build_committee_cache(RelativeEpoch::Current, spec)?;
Ok(Cow::Borrowed(state))
} else if state.slot() > block_slot {
Err(BlockError::BlockIsNotLaterThanParent {
block_slot,
parent_slot: state.slot(),
})
} else {
let mut state = state.clone_with(CloneConfig::committee_caches_only());
let target_slot = block_epoch.start_slot(E::slots_per_epoch());
// Advance the state into the same epoch as the block. Use the "partial" method since state
// roots are not important for proposer/attester shuffling.
partial_state_advance(&mut state, state_root_opt, target_slot, spec)
.map_err(|e| BlockError::BeaconChainError(BeaconChainError::from(e)))?;
state.build_committee_cache(RelativeEpoch::Current, spec)?;
Ok(Cow::Owned(state))
}
}
/// Obtains a read-locked `ValidatorPubkeyCache` from the `chain`.
fn get_validator_pubkey_cache<T: BeaconChainTypes>(
chain: &BeaconChain<T>,
) -> Result<RwLockReadGuard<ValidatorPubkeyCache<T>>, BlockError<T::EthSpec>> {
chain
.validator_pubkey_cache
.try_read_for(VALIDATOR_PUBKEY_CACHE_LOCK_TIMEOUT)
.ok_or(BeaconChainError::ValidatorPubkeyCacheLockTimeout)
.map_err(BlockError::BeaconChainError)
}
/// Produces an _empty_ `BlockSignatureVerifier`.
///
/// The signature verifier is empty because it does not yet have any of this block's signatures
/// added to it. Use `Self::apply_to_signature_verifier` to apply the signatures.
fn get_signature_verifier<'a, T: BeaconChainTypes>(
state: &'a BeaconState<T::EthSpec>,
validator_pubkey_cache: &'a ValidatorPubkeyCache<T>,
spec: &'a ChainSpec,
) -> BlockSignatureVerifier<
'a,
T::EthSpec,
impl Fn(usize) -> Option<Cow<'a, PublicKey>> + Clone,
impl Fn(&'a PublicKeyBytes) -> Option<Cow<'a, PublicKey>>,
> {
let get_pubkey = move |validator_index| {
// Disallow access to any validator pubkeys that are not in the current beacon state.
if validator_index < state.validators().len() {
validator_pubkey_cache
.get(validator_index)
.map(Cow::Borrowed)
} else {
None
}
};
let decompressor = move |pk_bytes| {
// Map compressed pubkey to validator index.
let validator_index = validator_pubkey_cache.get_index(pk_bytes)?;
// Map validator index to pubkey (respecting guard on unknown validators).
get_pubkey(validator_index)
};
BlockSignatureVerifier::new(state, get_pubkey, decompressor, spec)
}
/// Verify that `header` was signed with a valid signature from its proposer.
///
/// Return `Ok(())` if the signature is valid, and an `Err` otherwise.
fn verify_header_signature<T: BeaconChainTypes>(
chain: &BeaconChain<T>,
header: &SignedBeaconBlockHeader,
) -> Result<(), BlockError<T::EthSpec>> {
let proposer_pubkey = get_validator_pubkey_cache(chain)?
.get(header.message.proposer_index as usize)
.cloned()
.ok_or(BlockError::UnknownValidator(header.message.proposer_index))?;
let (fork, genesis_validators_root) = chain
.with_head(|head| {
Ok((
head.beacon_state.fork(),
head.beacon_state.genesis_validators_root(),
))
})
.map_err(|e: BlockError<T::EthSpec>| e)?;
if header.verify_signature::<T::EthSpec>(
&proposer_pubkey,
&fork,
genesis_validators_root,
&chain.spec,
) {
Ok(())
} else {
Err(BlockError::ProposalSignatureInvalid)
}
}
fn write_state<T: EthSpec>(prefix: &str, state: &BeaconState<T>, log: &Logger) {
if WRITE_BLOCK_PROCESSING_SSZ {
let root = state.tree_hash_root();
let filename = format!("{}_slot_{}_root_{}.ssz", prefix, state.slot(), root);
let mut path = std::env::temp_dir().join("lighthouse");
let _ = fs::create_dir_all(path.clone());
path = path.join(filename);
match fs::File::create(path.clone()) {
Ok(mut file) => {
let _ = file.write_all(&state.as_ssz_bytes());
}
Err(e) => error!(
log,
"Failed to log state";
"path" => format!("{:?}", path),
"error" => format!("{:?}", e)
),
}
}
}
fn write_block<T: EthSpec>(block: &SignedBeaconBlock<T>, root: Hash256, log: &Logger) {
if WRITE_BLOCK_PROCESSING_SSZ {
let filename = format!("block_slot_{}_root{}.ssz", block.slot(), root);
let mut path = std::env::temp_dir().join("lighthouse");
let _ = fs::create_dir_all(path.clone());
path = path.join(filename);
match fs::File::create(path.clone()) {
Ok(mut file) => {
let _ = file.write_all(&block.as_ssz_bytes());
}
Err(e) => error!(
log,
"Failed to log block";
"path" => format!("{:?}", path),
"error" => format!("{:?}", e)
),
}
}
}