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
}
func walk(ch *chain.Chain, hash, hdr []byte, height, blen, txs uint32) {
bh := btc.NewUint256(hash)
if _, ok := bidx[bh.Hash]; ok {
println("walk: ", bh.String(), "already in")
return
}
v := new(chain.BlockTreeNode)
v.BlockHash = bh
v.Height = height
v.BlockSize = blen
v.TxCount = txs
copy(v.BlockHeader[:], hdr)
bidx[bh.Hash] = v
cnt++
}
// Handle getheaders protocol command
// https://en.bitcoin.it/wiki/Protocol_specification#getheaders
func (c *OneConnection) GetHeaders(pl []byte) {
h2get, hashstop, e := parseLocatorsPayload(pl)
if e != nil || hashstop == nil {
println("GetHeaders: error parsing payload from", c.PeerAddr.Ip())
c.DoS("BadGetHdrs")
return
}
if common.DebugLevel > 1 {
println("GetHeaders", len(h2get), hashstop.String())
}
var best_block, last_block *chain.BlockTreeNode
common.BlockChain.BlockIndexAccess.Lock()
if len(h2get) > 0 {
for i := range h2get {
if bl, ok := common.BlockChain.BlockIndex[h2get[i].BIdx()]; ok {
if best_block == nil || bl.Height > best_block.Height {
best_block = bl
}
}
}
} else {
best_block = common.BlockChain.BlockIndex[hashstop.BIdx()]
}
last_block = common.BlockChain.BlockTreeEnd
common.BlockChain.BlockIndexAccess.Unlock()
var resp []byte
var cnt uint32
for cnt < 2000 {
best_block = best_block.FindPathTo(last_block)
if best_block == nil {
break
}
resp = append(resp, append(best_block.BlockHeader[:], 0)...) // 81st byte is always zero
cnt++
}
out := new(bytes.Buffer)
btc.WriteVlen(out, uint64(cnt))
out.Write(resp)
c.SendRawMsg("headers", out.Bytes())
return
}