github.com/prysmaticlabs/prysm@v1.4.4/beacon-chain/sync/validate_voluntary_exit.go (about)

     1  package sync
     2  
     3  import (
     4  	"context"
     5  
     6  	"github.com/libp2p/go-libp2p-core/peer"
     7  	pubsub "github.com/libp2p/go-libp2p-pubsub"
     8  	types "github.com/prysmaticlabs/eth2-types"
     9  	"github.com/prysmaticlabs/prysm/beacon-chain/core/blocks"
    10  	ethpb "github.com/prysmaticlabs/prysm/proto/eth/v1alpha1"
    11  	"github.com/prysmaticlabs/prysm/shared/traceutil"
    12  	"go.opencensus.io/trace"
    13  )
    14  
    15  // Clients who receive a voluntary exit on this topic MUST validate the conditions within process_voluntary_exit before
    16  // forwarding it across the network.
    17  func (s *Service) validateVoluntaryExit(ctx context.Context, pid peer.ID, msg *pubsub.Message) pubsub.ValidationResult {
    18  	// Validation runs on publish (not just subscriptions), so we should approve any message from
    19  	// ourselves.
    20  	if pid == s.cfg.P2P.PeerID() {
    21  		return pubsub.ValidationAccept
    22  	}
    23  
    24  	// The head state will be too far away to validate any voluntary exit.
    25  	if s.cfg.InitialSync.Syncing() {
    26  		return pubsub.ValidationIgnore
    27  	}
    28  
    29  	ctx, span := trace.StartSpan(ctx, "sync.validateVoluntaryExit")
    30  	defer span.End()
    31  
    32  	m, err := s.decodePubsubMessage(msg)
    33  	if err != nil {
    34  		log.WithError(err).Debug("Could not decode message")
    35  		traceutil.AnnotateError(span, err)
    36  		return pubsub.ValidationReject
    37  	}
    38  
    39  	exit, ok := m.(*ethpb.SignedVoluntaryExit)
    40  	if !ok {
    41  		return pubsub.ValidationReject
    42  	}
    43  
    44  	if exit.Exit == nil {
    45  		return pubsub.ValidationReject
    46  	}
    47  	if s.hasSeenExitIndex(exit.Exit.ValidatorIndex) {
    48  		return pubsub.ValidationIgnore
    49  	}
    50  
    51  	headState, err := s.cfg.Chain.HeadState(ctx)
    52  	if err != nil {
    53  		return pubsub.ValidationIgnore
    54  	}
    55  
    56  	if uint64(exit.Exit.ValidatorIndex) >= uint64(headState.NumValidators()) {
    57  		return pubsub.ValidationReject
    58  	}
    59  	val, err := headState.ValidatorAtIndexReadOnly(exit.Exit.ValidatorIndex)
    60  	if err != nil {
    61  		return pubsub.ValidationIgnore
    62  	}
    63  	if err := blocks.VerifyExitAndSignature(val, headState.Slot(), headState.Fork(), exit, headState.GenesisValidatorRoot()); err != nil {
    64  		return pubsub.ValidationReject
    65  	}
    66  
    67  	msg.ValidatorData = exit // Used in downstream subscriber
    68  
    69  	return pubsub.ValidationAccept
    70  }
    71  
    72  // Returns true if the node has already received a valid exit request for the validator with index `i`.
    73  func (s *Service) hasSeenExitIndex(i types.ValidatorIndex) bool {
    74  	s.seenExitLock.RLock()
    75  	defer s.seenExitLock.RUnlock()
    76  	_, seen := s.seenExitCache.Get(i)
    77  	return seen
    78  }
    79  
    80  // Set exit request index `i` in seen exit request cache.
    81  func (s *Service) setExitIndexSeen(i types.ValidatorIndex) {
    82  	s.seenExitLock.Lock()
    83  	defer s.seenExitLock.Unlock()
    84  	s.seenExitCache.Add(i, true)
    85  }