protocol/validation/block.go

   1 package validation
   2
   3 import (
   4         "time"
   5
   6         log "github.com/sirupsen/logrus"
   7
   8         "github.com/vapor/consensus"
   9         "github.com/vapor/consensus/difficulty"
  10         "github.com/vapor/errors"
  11         "github.com/vapor/protocol/bc"
  12         "github.com/vapor/protocol/bc/types"
  13         "github.com/vapor/protocol/state"
  14 )
  15
  16 const logModule = "leveldb"
  17
  18 var (
  19         errBadTimestamp          = errors.New("block timestamp is not in the valid range")
  20         errBadBits               = errors.New("block bits is invalid")
  21         errMismatchedBlock       = errors.New("mismatched block")
  22         errMismatchedMerkleRoot  = errors.New("mismatched merkle root")
  23         errMisorderedBlockHeight = errors.New("misordered block height")
  24         errOverBlockLimit        = errors.New("block's gas is over the limit")
  25         errWorkProof             = errors.New("invalid difficulty proof of work")
  26         errVersionRegression     = errors.New("version regression")
  27 )
  28
  29 func checkBlockTime(b *bc.Block, parent *state.BlockNode) error {
  30         if b.Timestamp > uint64(time.Now().Unix())+consensus.MaxTimeOffsetSeconds {
  31                 return errBadTimestamp
  32         }
  33
  34         if b.Timestamp <= parent.CalcPastMedianTime() {
  35                 return errBadTimestamp
  36         }
  37         return nil
  38 }
  39
  40 func checkCoinbaseAmount(b *bc.Block, amount uint64) error {
  41         if len(b.Transactions) == 0 {
  42                 return errors.Wrap(ErrWrongCoinbaseTransaction, "block is empty")
  43         }
  44
  45         tx := b.Transactions[0]
  46         if len(tx.TxHeader.ResultIds) != 1 {
  47                 return errors.Wrap(ErrWrongCoinbaseTransaction, "have more than 1 output")
  48         }
  49
  50         output, err := tx.Output(*tx.TxHeader.ResultIds[0])
  51         if err != nil {
  52                 return err
  53         }
  54
  55         if output.Source.Value.Amount != amount {
  56                 return errors.Wrap(ErrWrongCoinbaseTransaction, "dismatch output amount")
  57         }
  58         return nil
  59 }
  60
  61 // ValidateBlockHeader check the block's header
  62 func ValidateBlockHeader(b *bc.Block, parent *state.BlockNode) error {
  63         if b.Version != 1 {
  64                 return errors.WithDetailf(errVersionRegression, "previous block verson %d, current block version %d", parent.Version, b.Version)
  65         }
  66         if b.Height != parent.Height+1 {
  67                 return errors.WithDetailf(errMisorderedBlockHeight, "previous block height %d, current block height %d", parent.Height, b.Height)
  68         }
  69         if b.Bits != parent.CalcNextBits() {
  70                 return errBadBits
  71         }
  72         if parent.Hash != *b.PreviousBlockId {
  73                 return errors.WithDetailf(errMismatchedBlock, "previous block ID %x, current block wants %x", parent.Hash.Bytes(), b.PreviousBlockId.Bytes())
  74         }
  75         if err := checkBlockTime(b, parent); err != nil {
  76                 return err
  77         }
  78         if !difficulty.CheckProofOfWork(&b.ID, parent.CalcNextSeed(), b.BlockHeader.Bits) {
  79                 return errWorkProof
  80         }
  81         return nil
  82 }
  83
  84 // ValidateBlock validates a block and the transactions within.
  85 func ValidateBlock(b *bc.Block, parent *state.BlockNode) error {
  86         startTime := time.Now()
  87         if err := ValidateBlockHeader(b, parent); err != nil {
  88                 return err
  89         }
  90
  91         blockGasSum := uint64(0)
  92         coinbaseAmount := consensus.BlockSubsidy(b.BlockHeader.Height)
  93         b.TransactionStatus = bc.NewTransactionStatus()
  94
  95         for i, tx := range b.Transactions {
  96                 gasStatus, err := ValidateTx(tx, b)
  97                 if !gasStatus.GasValid {
  98                         return errors.Wrapf(err, "validate of transaction %d of %d", i, len(b.Transactions))
  99                 }
 100
 101                 if err := b.TransactionStatus.SetStatus(i, err != nil); err != nil {
 102                         return err
 103                 }
 104                 coinbaseAmount += gasStatus.BTMValue
 105                 if blockGasSum += uint64(gasStatus.GasUsed); blockGasSum > consensus.MaxBlockGas {
 106                         return errOverBlockLimit
 107                 }
 108         }
 109
 110         if err := checkCoinbaseAmount(b, coinbaseAmount); err != nil {
 111                 return err
 112         }
 113
 114         txMerkleRoot, err := types.TxMerkleRoot(b.Transactions)
 115         if err != nil {
 116                 return errors.Wrap(err, "computing transaction id merkle root")
 117         }
 118         if txMerkleRoot != *b.TransactionsRoot {
 119                 return errors.WithDetailf(errMismatchedMerkleRoot, "transaction id merkle root")
 120         }
 121
 122         txStatusHash, err := types.TxStatusMerkleRoot(b.TransactionStatus.VerifyStatus)
 123         if err != nil {
 124                 return errors.Wrap(err, "computing transaction status merkle root")
 125         }
 126         if txStatusHash != *b.TransactionStatusHash {
 127                 return errors.WithDetailf(errMismatchedMerkleRoot, "transaction status merkle root")
 128         }
 129
 130         log.WithFields(log.Fields{
 131                 "module":   logModule,
 132                 "height":   b.Height,
 133                 "hash":     b.ID.String(),
 134                 "duration": time.Since(startTime),
 135         }).Debug("finish validate block")
 136         return nil
 137 }