Ejemplo n.º 1
0
// This function either appends a new block at the end of the existing chain
// in which case it also applies all the transactions to the unspent database.
// If the block does is not the heighest, it is added to the chain, but maked
// as an orphan - its transaction will be verified only if the chain would swap
// to its branch later on.
func (ch *Chain) AcceptBlock(bl *btc.Block) (e error) {

	prevblk, ok := ch.BlockIndex[btc.NewUint256(bl.ParentHash()).BIdx()]
	if !ok {
		panic("This should not happen")
	}

	// create new BlockTreeNode
	cur := new(BlockTreeNode)
	cur.BlockHash = bl.Hash
	cur.Parent = prevblk
	cur.Height = prevblk.Height + 1
	cur.BlockSize = uint32(len(bl.Raw))
	cur.TxCount = uint32(bl.TxCount)
	copy(cur.BlockHeader[:], bl.Raw[:80])

	// Add this block to the block index
	ch.BlockIndexAccess.Lock()
	prevblk.addChild(cur)
	ch.BlockIndex[cur.BlockHash.BIdx()] = cur
	ch.BlockIndexAccess.Unlock()

	if ch.BlockTreeEnd == prevblk {
		// The head of out chain - apply the transactions
		var changes *BlockChanges
		changes, e = ch.ProcessBlockTransactions(bl, cur.Height, bl.LastKnownHeight)
		if e != nil {
			// ProcessBlockTransactions failed, so trash the block.
			println("ProcessBlockTransactions ", cur.BlockHash.String(), cur.Height, e.Error())
			ch.BlockIndexAccess.Lock()
			cur.Parent.delChild(cur)
			delete(ch.BlockIndex, cur.BlockHash.BIdx())
			ch.BlockIndexAccess.Unlock()
		} else {
			// ProcessBlockTransactions succeeded, so save the block as "trusted".
			bl.Trusted = true
			ch.Blocks.BlockAdd(cur.Height, bl)
			// Apply the block's trabnsactions to the unspent database:
			ch.Unspent.CommitBlockTxs(changes, bl.Hash.Hash[:])
			if !ch.DoNotSync {
				ch.Blocks.Sync()
			}
			ch.BlockTreeEnd = cur // Advance the head
		}
	} else {
		// The block's parent is not the current head of the chain...

		// Save the block, though do not makt it as "trusted" just yet
		ch.Blocks.BlockAdd(cur.Height, bl)

		// If it has a bigger height than the current head,
		// ... move the coin state into a new branch.
		if cur.Height > ch.BlockTreeEnd.Height {
			ch.MoveToBlock(cur)
		}
	}

	return
}
Ejemplo n.º 2
0
Archivo: hdrs.go Proyecto: wchh/gocoin
func chkblock(bl *btc.Block) (er error) {
	// Check timestamp (must not be higher than now +2 hours)
	if int64(bl.BlockTime()) > time.Now().Unix()+2*60*60 {
		er = errors.New("CheckBlock() : block timestamp too far in the future")
		return
	}

	MemBlockChainMutex.Lock()
	if prv, pres := MemBlockChain.BlockIndex[bl.Hash.BIdx()]; pres {
		MemBlockChainMutex.Unlock()
		if prv.Parent == nil {
			// This is genesis block
			er = errors.New("Genesis")
			return
		} else {
			return
		}
	}

	prevblk, ok := MemBlockChain.BlockIndex[btc.NewUint256(bl.ParentHash()).BIdx()]
	if !ok {
		er = errors.New("CheckBlock: " + bl.Hash.String() + " parent not found")
		return
	}

	// Check proof of work
	gnwr := MemBlockChain.GetNextWorkRequired(prevblk, bl.BlockTime())
	if bl.Bits() != gnwr {
		if !Testnet || ((prevblk.Height+1)%2016) != 0 {
			MemBlockChainMutex.Unlock()
			er = errors.New(fmt.Sprint("CheckBlock: Incorrect proof of work at block", prevblk.Height+1))
			return
		}
	}

	cur := new(chain.BlockTreeNode)
	cur.BlockHash = bl.Hash
	cur.Parent = prevblk
	cur.Height = prevblk.Height + 1
	cur.TxCount = uint32(bl.TxCount)
	copy(cur.BlockHeader[:], bl.Raw[:80])
	prevblk.Childs = append(prevblk.Childs, cur)
	MemBlockChain.BlockIndex[cur.BlockHash.BIdx()] = cur
	MemBlockChainMutex.Unlock()

	LastBlock.Mutex.Lock()
	if cur.Height > LastBlock.node.Height {
		LastBlock.node = cur
	}
	LastBlock.Mutex.Unlock()

	return
}
Ejemplo n.º 3
0
func (ch *Chain) CheckBlock(bl *btc.Block) (er error, dos bool, maybelater bool) {
	// Size limits
	if len(bl.Raw) < 81 || len(bl.Raw) > btc.MAX_BLOCK_SIZE {
		er = errors.New("CheckBlock() : size limits failed")
		dos = true
		return
	}

	if bl.Version() == 0 {
		er = errors.New("CheckBlock() : Block version 0 not allowed")
		dos = true
		return
	}

	// Check timestamp (must not be higher than now +2 hours)
	if int64(bl.BlockTime()) > time.Now().Unix()+2*60*60 {
		er = errors.New("CheckBlock() : block timestamp too far in the future")
		dos = true
		return
	}

	if prv, pres := ch.BlockIndex[bl.Hash.BIdx()]; pres {
		if prv.Parent == nil {
			// This is genesis block
			er = errors.New("Genesis")
			return
		} else {
			er = errors.New("CheckBlock: " + bl.Hash.String() + " already in")
			return
		}
	}

	prevblk, ok := ch.BlockIndex[btc.NewUint256(bl.ParentHash()).BIdx()]
	if !ok {
		er = errors.New("CheckBlock: " + bl.Hash.String() + " parent not found")
		maybelater = true
		return
	}

	height := prevblk.Height + 1

	// Reject the block if it reaches into the chain deeper than our unwind buffer
	if prevblk != ch.BlockTreeEnd && int(ch.BlockTreeEnd.Height)-int(height) >= MovingCheckopintDepth {
		er = errors.New(fmt.Sprint("CheckBlock: btc.Block ", bl.Hash.String(),
			" hooks too deep into the chain: ", height, "/", ch.BlockTreeEnd.Height, " ",
			btc.NewUint256(bl.ParentHash()).String()))
		return
	}

	// Check proof of work
	gnwr := ch.GetNextWorkRequired(prevblk, bl.BlockTime())
	if bl.Bits() != gnwr {
		println("AcceptBlock() : incorrect proof of work ", bl.Bits, " at block", height, " exp:", gnwr)

		// Here is a "solution" for whatever shit there is in testnet3, that nobody can explain me:
		if !ch.testnet() || (height%2016) != 0 {
			er = errors.New("CheckBlock: incorrect proof of work")
			dos = true
			return
		}
	}

	// Count block versions within the Majority Window
	var majority_v2, majority_v3 uint
	n := prevblk
	for cnt := uint(0); cnt < ch.Consensus.Window && n != nil; cnt++ {
		ver := binary.LittleEndian.Uint32(n.BlockHeader[0:4])
		if ver >= 2 {
			majority_v2++
			if ver >= 3 {
				majority_v3++
			}
		}
		n = n.Parent
	}

	if bl.Version() < 2 && majority_v2 >= ch.Consensus.RejectBlock {
		er = errors.New("CheckBlock() : Rejected nVersion=1 block")
		dos = true
		return
	}

	if bl.Version() < 3 && majority_v3 >= ch.Consensus.RejectBlock {
		er = errors.New("CheckBlock() : Rejected nVersion=2 block")
		dos = true
		return
	}

	if bl.Txs == nil {
		er = bl.BuildTxList()
		if er != nil {
			dos = true
			return
		}
	}

	if !bl.Trusted {
		if bl.Version() >= 2 && majority_v2 >= ch.Consensus.EnforceUpgrade {
			var exp []byte
			if height >= 0x800000 {
				if height >= 0x80000000 {
					exp = []byte{5, byte(height), byte(height >> 8), byte(height >> 16), byte(height >> 24), 0}
				} else {
					exp = []byte{4, byte(height), byte(height >> 8), byte(height >> 16), byte(height >> 24)}
				}
			} else {
				exp = []byte{3, byte(height), byte(height >> 8), byte(height >> 16)}
			}
			if len(bl.Txs[0].TxIn[0].ScriptSig) < len(exp) || !bytes.Equal(exp, bl.Txs[0].TxIn[0].ScriptSig[:len(exp)]) {
				er = errors.New("CheckBlock() : Unexpected block number in coinbase: " + bl.Hash.String())
				dos = true
				return
			}
		}

		// This is a stupid check, but well, we need to be satoshi compatible
		if len(bl.Txs) == 0 || !bl.Txs[0].IsCoinBase() {
			er = errors.New("CheckBlock() : first tx is not coinbase: " + bl.Hash.String())
			dos = true
			return
		}

		// Check Merkle Root - that's importnant
		if !bytes.Equal(btc.GetMerkel(bl.Txs), bl.MerkleRoot()) {
			er = errors.New("CheckBlock() : Merkle Root mismatch")
			dos = true
			return
		}

		// Check transactions - this is the most time consuming task
		if !CheckTransactions(bl.Txs, height, bl.BlockTime()) {
			er = errors.New("CheckBlock() : CheckTransactions() failed")
			dos = true
			return
		}
	}

	if bl.BlockTime() >= BIP16SwitchTime {
		bl.VerifyFlags = script.VER_P2SH
	} else {
		bl.VerifyFlags = 0
	}

	if majority_v3 >= ch.Consensus.EnforceUpgrade {
		bl.VerifyFlags |= script.VER_DERSIG
	}

	return
}