protocol/bbft.go

   1 package protocol
   2
   3 import (
   4         "encoding/hex"
   5         "fmt"
   6
   7         log "github.com/sirupsen/logrus"
   8
   9         "github.com/vapor/config"
  10         "github.com/vapor/errors"
  11         "github.com/vapor/event"
  12         "github.com/vapor/protocol/bc"
  13         "github.com/vapor/protocol/bc/types"
  14         "github.com/vapor/protocol/state"
  15 )
  16
  17 const (
  18         maxSignatureCacheSize = 10000
  19 )
  20
  21 var (
  22         errVotingOperationOverFlow = errors.New("voting operation result overflow")
  23         errDoubleSignBlock         = errors.New("the consensus is double sign in same height of different block")
  24         errInvalidSignature        = errors.New("the signature of block is invalid")
  25         errSignForkChain           = errors.New("can not sign fork before the irreversible block")
  26 )
  27
  28 func signCacheKey(blockHash, pubkey string) string {
  29         return fmt.Sprintf("%s:%s", blockHash, pubkey)
  30 }
  31
  32 func (c *Chain) isIrreversible(blockNode *state.BlockNode) bool {
  33         consensusNodes, err := c.consensusNodeManager.getConsensusNodes(&blockNode.Parent.Hash)
  34         if err != nil {
  35                 return false
  36         }
  37
  38         signCount := 0
  39         for i := 0; i < len(consensusNodes); i++ {
  40                 if ok, _ := blockNode.BlockWitness.Test(uint32(i)); ok {
  41                         signCount++
  42                 }
  43         }
  44
  45         return signCount > len(consensusNodes)*2/3
  46 }
  47
  48 // NextLeaderTime returns the start time of the specified public key as the next leader node
  49 func (c *Chain) IsBlocker(prevBlockHash *bc.Hash, pubkey string, timeStamp uint64) (bool, error) {
  50         return c.consensusNodeManager.isBlocker(prevBlockHash, pubkey, timeStamp)
  51 }
  52
  53 // ProcessBlockSignature process the received block signature messages
  54 // return whether a block become irreversible, if so, the chain module must update status
  55 func (c *Chain) ProcessBlockSignature(signature, xPub []byte, blockHash *bc.Hash) error {
  56         xpubStr := hex.EncodeToString(xPub[:])
  57         blockNode := c.index.GetNode(blockHash)
  58         // save the signature if the block is not exist
  59         if blockNode == nil {
  60                 cacheKey := signCacheKey(blockHash.String(), xpubStr)
  61                 c.signatureCache.Add(cacheKey, signature)
  62                 return nil
  63         }
  64
  65         consensusNode, err := c.consensusNodeManager.getConsensusNode(&blockNode.Parent.Hash, xpubStr)
  66         if err != nil {
  67                 return err
  68         }
  69
  70         if exist, _ := blockNode.BlockWitness.Test(uint32(consensusNode.Order)); exist {
  71                 return nil
  72         }
  73
  74         if err := c.checkNodeSign(blockNode.BlockHeader(), consensusNode, signature); err != nil {
  75                 return err
  76         }
  77
  78         if err := c.updateBlockSignature(blockNode, consensusNode.Order, signature); err != nil {
  79                 return err
  80         }
  81         return c.eventDispatcher.Post(event.BlockSignatureEvent{BlockHash: *blockHash, Signature: signature, XPub: xPub})
  82 }
  83
  84 // validateSign verify the signatures of block, and return the number of correct signature
  85 // if some signature is invalid, they will be reset to nil
  86 // if the block has not the signature of blocker, it will return error
  87 func (c *Chain) validateSign(block *types.Block) error {
  88         consensusNodeMap, err := c.consensusNodeManager.getConsensusNodes(&block.PreviousBlockHash)
  89         if err != nil {
  90                 return err
  91         }
  92
  93         hasBlockerSign := false
  94         blockHash := block.Hash()
  95         for pubKey, node := range consensusNodeMap {
  96                 if len(block.Witness) <= int(node.Order) {
  97                         continue
  98                 }
  99
 100                 if block.Witness[node.Order] == nil {
 101                         cachekey := signCacheKey(blockHash.String(), pubKey)
 102                         if signature, ok := c.signatureCache.Get(cachekey); ok {
 103                                 block.Witness[node.Order] = signature.([]byte)
 104                         } else {
 105                                 continue
 106                         }
 107                 }
 108
 109                 if err := c.checkNodeSign(&block.BlockHeader, node, block.Witness[node.Order]); err == errDoubleSignBlock {
 110                         log.WithFields(log.Fields{"module": logModule, "blockHash": blockHash.String(), "pubKey": pubKey}).Warn("the consensus node double sign the same height of different block")
 111                         block.Witness[node.Order] = nil
 112                         continue
 113                 } else if err != nil {
 114                         return err
 115                 }
 116
 117                 isBlocker, err := c.consensusNodeManager.isBlocker(&block.PreviousBlockHash, pubKey, block.Timestamp)
 118                 if err != nil {
 119                         return err
 120                 }
 121
 122                 if isBlocker {
 123                         hasBlockerSign = true
 124                 }
 125
 126         }
 127
 128         if !hasBlockerSign {
 129                 return errors.New("the block has no signature of the blocker")
 130         }
 131         return nil
 132 }
 133
 134 func (c *Chain) checkNodeSign(bh *types.BlockHeader, consensusNode *state.ConsensusNode, signature []byte) error {
 135         if !consensusNode.XPub.Verify(bh.Hash().Bytes(), signature) {
 136                 return errInvalidSignature
 137         }
 138
 139         blockNodes := c.consensusNodeManager.blockIndex.NodesByHeight(bh.Height)
 140         for _, blockNode := range blockNodes {
 141                 if blockNode.Hash == bh.Hash() {
 142                         continue
 143                 }
 144
 145                 consensusNode, err := c.consensusNodeManager.getConsensusNode(&blockNode.Parent.Hash, consensusNode.XPub.String())
 146                 if err != nil && err != errNotFoundConsensusNode {
 147                         return err
 148                 }
 149
 150                 if err == errNotFoundConsensusNode {
 151                         continue
 152                 }
 153
 154                 if ok, err := blockNode.BlockWitness.Test(uint32(consensusNode.Order)); err == nil && ok {
 155                         return errDoubleSignBlock
 156                 }
 157         }
 158         return nil
 159 }
 160
 161 // SignBlock signing the block if current node is consensus node
 162 func (c *Chain) SignBlock(block *types.Block) ([]byte, error) {
 163         xprv := config.CommonConfig.PrivateKey()
 164         xpubStr := xprv.XPub().String()
 165         node, err := c.consensusNodeManager.getConsensusNode(&block.PreviousBlockHash, xpubStr)
 166         if err == errNotFoundConsensusNode {
 167                 return nil, nil
 168         } else if err != nil {
 169                 return nil, err
 170         }
 171
 172         c.cond.L.Lock()
 173         defer c.cond.L.Unlock()
 174         //check double sign in same block height
 175         blockNodes := c.consensusNodeManager.blockIndex.NodesByHeight(block.Height)
 176         for _, blockNode := range blockNodes {
 177                 // Has already signed the same height block
 178                 if ok, err := blockNode.BlockWitness.Test(uint32(node.Order)); err == nil && ok {
 179                         return nil, nil
 180                 }
 181         }
 182
 183         for blockNode := c.index.GetNode(&block.PreviousBlockHash); !c.index.InMainchain(blockNode.Hash); blockNode = blockNode.Parent {
 184                 if blockNode.Height <= c.bestIrreversibleNode.Height {
 185                         return nil, errSignForkChain
 186                 }
 187         }
 188
 189         signature := block.Witness[node.Order]
 190         if len(signature) == 0 {
 191                 signature = xprv.Sign(block.Hash().Bytes())
 192                 block.Witness[node.Order] = signature
 193         }
 194         return signature, nil
 195 }
 196
 197 func (c *Chain) updateBlockSignature(blockNode *state.BlockNode, nodeOrder uint64, signature []byte) error {
 198         if err := blockNode.BlockWitness.Set(uint32(nodeOrder)); err != nil {
 199                 return err
 200         }
 201
 202         block, err := c.store.GetBlock(&blockNode.Hash)
 203         if err != nil {
 204                 return err
 205         }
 206
 207         block.Witness[nodeOrder] = signature
 208         txStatus, err := c.store.GetTransactionStatus(&blockNode.Hash)
 209         if err != nil {
 210                 return err
 211         }
 212
 213         if err := c.store.SaveBlock(block, txStatus); err != nil {
 214                 return err
 215         }
 216
 217         c.cond.L.Lock()
 218         defer c.cond.L.Unlock()
 219         if c.isIrreversible(blockNode) && blockNode.Height > c.bestIrreversibleNode.Height {
 220                 if err := c.store.SaveChainStatus(c.bestNode, blockNode, state.NewUtxoViewpoint(), []*state.VoteResult{}); err != nil {
 221                         return err
 222                 }
 223
 224                 c.bestIrreversibleNode = blockNode
 225         }
 226         return nil
 227 }