func (ch *Chain) PreCheckBlock(bl *btc.Block) (er error, dos bool, maybelater bool) {
// Size limits
if len(bl.Raw) < 81 {
er = errors.New("CheckBlock() : size limits failed - RPC_Result:bad-blk-length")
dos = true
return
}
if bl.Version() == 0 {
er = errors.New("CheckBlock() : Block version 0 not allowed - RPC_Result:bad-version")
dos = true
return
}
// Check proof-of-work
if !btc.CheckProofOfWork(bl.Hash, bl.Bits()) {
er = errors.New("CheckBlock() : proof of work failed - RPC_Result:high-hash")
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 - RPC_Result:time-too-new")
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 - RPC_Result:duplicate")
return
}
}
prevblk, ok := ch.BlockIndex[btc.NewUint256(bl.ParentHash()).BIdx()]
if !ok {
er = errors.New("CheckBlock: " + bl.Hash.String() + " parent not found - RPC_Result:bad-prevblk")
maybelater = true
return
}
bl.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(bl.Height) >= MovingCheckopintDepth {
er = errors.New(fmt.Sprint("CheckBlock: btc.Block ", bl.Hash.String(),
" hooks too deep into the chain: ", bl.Height, "/", ch.BlockTreeEnd.Height, " ",
btc.NewUint256(bl.ParentHash()).String(), " - RPC_Result:bad-prevblk"))
return
}
// Check proof of work
gnwr := ch.GetNextWorkRequired(prevblk, bl.BlockTime())
if bl.Bits() != gnwr {
er = errors.New("CheckBlock: incorrect proof of work - RPC_Result:bad-diffbits")
dos = true
return
}
// Check timestamp against prev
bl.MedianPastTime = prevblk.GetMedianTimePast()
if bl.BlockTime() <= bl.MedianPastTime {
er = errors.New("CheckBlock: block's timestamp is too early - RPC_Result:time-too-old")
dos = true
return
}
if bl.Version() < 2 && bl.Height >= ch.Consensus.BIP34Height ||
bl.Version() < 3 && bl.Height >= ch.Consensus.BIP66Height ||
bl.Version() < 4 && bl.Height >= ch.Consensus.BIP65Height {
// bad block version
erstr := fmt.Sprintf("0x%08x", bl.Version())
er = errors.New("CheckBlock() : Rejected Version=" + erstr + " blolck - RPC_Result:bad-version(" + erstr + ")")
dos = true
return
}
return
}
