prysm-pulse/beacon-chain/blockchain/weak_subjectivity_checks.go
kasey 8140a1a7e0
update info message about ws checkpoint (#10871)
Co-authored-by: Kasey Kirkham <kasey@users.noreply.github.com>
Co-authored-by: prylabs-bulldozer[bot] <58059840+prylabs-bulldozer[bot]@users.noreply.github.com>
2022-06-14 00:55:00 +00:00

94 lines
3.7 KiB
Go

package blockchain
import (
"context"
"fmt"
"github.com/pkg/errors"
"github.com/prysmaticlabs/prysm/beacon-chain/db/filters"
"github.com/prysmaticlabs/prysm/config/params"
types "github.com/prysmaticlabs/prysm/consensus-types/primitives"
"github.com/prysmaticlabs/prysm/encoding/bytesutil"
ethpb "github.com/prysmaticlabs/prysm/proto/prysm/v1alpha1"
"github.com/prysmaticlabs/prysm/time/slots"
)
type weakSubjectivityDB interface {
HasBlock(ctx context.Context, blockRoot [32]byte) bool
BlockRoots(ctx context.Context, f *filters.QueryFilter) ([][32]byte, error)
}
type WeakSubjectivityVerifier struct {
enabled bool
verified bool
root [32]byte
epoch types.Epoch
slot types.Slot
db weakSubjectivityDB
}
// NewWeakSubjectivityVerifier validates a checkpoint, and if valid, uses it to initialize a weak subjectivity verifier.
func NewWeakSubjectivityVerifier(wsc *ethpb.Checkpoint, db weakSubjectivityDB) (*WeakSubjectivityVerifier, error) {
if wsc == nil || len(wsc.Root) == 0 || wsc.Epoch == 0 {
log.Info("--weak-subjectivity-checkpoint not provided. Prysm recommends providing a weak subjectivity checkpoint" +
"for nodes synced from genesis, or manual verification of block and state roots for checkpoint sync nodes.")
return &WeakSubjectivityVerifier{
enabled: false,
}, nil
}
startSlot, err := slots.EpochStart(wsc.Epoch)
if err != nil {
return nil, err
}
return &WeakSubjectivityVerifier{
enabled: true,
verified: false,
root: bytesutil.ToBytes32(wsc.Root),
epoch: wsc.Epoch,
db: db,
slot: startSlot,
}, nil
}
// VerifyWeakSubjectivity verifies the weak subjectivity root in the service struct.
// Reference design: https://github.com/ethereum/consensus-specs/blob/master/specs/phase0/weak-subjectivity.md#weak-subjectivity-sync-procedure
func (v *WeakSubjectivityVerifier) VerifyWeakSubjectivity(ctx context.Context, finalizedEpoch types.Epoch) error {
if v.verified || !v.enabled {
return nil
}
// Two conditions are described in the specs:
// IF epoch_number > store.finalized_checkpoint.epoch,
// then ASSERT during block sync that block with root block_root
// is in the sync path at epoch epoch_number. Emit descriptive critical error if this assert fails,
// then exit client process.
// we do not handle this case ^, because we can only blocks that have been processed / are currently
// in line for finalization, we don't have the ability to look ahead. so we only satisfy the following:
// IF epoch_number <= store.finalized_checkpoint.epoch,
// then ASSERT that the block in the canonical chain at epoch epoch_number has root block_root.
// Emit descriptive critical error if this assert fails, then exit client process.
if v.epoch > finalizedEpoch {
return nil
}
log.Infof("Performing weak subjectivity check for root %#x in epoch %d", v.root, v.epoch)
if !v.db.HasBlock(ctx, v.root) {
return errors.Wrap(errWSBlockNotFound, fmt.Sprintf("missing root %#x", v.root))
}
endSlot := v.slot + params.BeaconConfig().SlotsPerEpoch
filter := filters.NewFilter().SetStartSlot(v.slot).SetEndSlot(endSlot)
// A node should have the weak subjectivity block corresponds to the correct epoch in the DB.
log.Infof("Searching block roots for weak subjectivity root=%#x, between slots %d-%d", v.root, v.slot, endSlot)
roots, err := v.db.BlockRoots(ctx, filter)
if err != nil {
return errors.Wrap(err, "error while retrieving block roots to verify weak subjectivity")
}
for _, root := range roots {
if v.root == root {
log.Info("Weak subjectivity check has passed!!")
v.verified = true
return nil
}
}
return errors.Wrap(errWSBlockNotFoundInEpoch, fmt.Sprintf("root=%#x, epoch=%d", v.root, v.epoch))
}