Beispiel #1
0
func (self *XEth) doSign(from common.Address, hash common.Hash, didUnlock bool) ([]byte, error) {
	sig, err := self.backend.AccountManager().Sign(accounts.Account{Address: from}, hash.Bytes())
	if err == accounts.ErrLocked {
		if didUnlock {
			return nil, fmt.Errorf("signer account still locked after successful unlock")
		}
		if !self.frontend.UnlockAccount(from.Bytes()) {
			return nil, fmt.Errorf("could not unlock signer account")
		}
		// retry signing, the account should now be unlocked.
		return self.doSign(from, hash, true)
	} else if err != nil {
		return nil, err
	}
	return sig, nil
}
Beispiel #2
0
// banBlocks retrieves a batch of blocks from a peer feeding us invalid hashes,
// and bans the head of the retrieved batch.
//
// This method only fetches one single batch as the goal is not ban an entire
// (potentially long) invalid chain - wasting a lot of time in the meanwhile -,
// but rather to gradually build up a blacklist if the peer keeps reconnecting.
func (d *Downloader) banBlocks(peerId string, head common.Hash) error {
	glog.V(logger.Debug).Infof("Banning a batch out of %d blocks from %s", d.queue.Pending(), peerId)

	// Ask the peer being banned for a batch of blocks from the banning point
	peer := d.peers.Peer(peerId)
	if peer == nil {
		return nil
	}
	request := d.queue.Reserve(peer, MaxBlockFetch)
	if request == nil {
		return nil
	}
	if err := peer.Fetch(request); err != nil {
		return err
	}
	// Wait a bit for the reply to arrive, and ban if done so
	timeout := time.After(blockHardTTL)
	for {
		select {
		case <-d.cancelCh:
			return errCancelBlockFetch

		case <-timeout:
			return errTimeout

		case <-d.hashCh:
			// Out of bounds hashes received, ignore them

		case blockPack := <-d.blockCh:
			blocks := blockPack.blocks

			// Short circuit if it's a stale cross check
			if len(blocks) == 1 {
				block := blocks[0]
				if _, ok := d.checks[block.Hash()]; ok {
					delete(d.checks, block.Hash())
					break
				}
			}
			// Short circuit if it's not from the peer being banned
			if blockPack.peerId != peerId {
				break
			}
			// Short circuit if no blocks were returned
			if len(blocks) == 0 {
				return errors.New("no blocks returned to ban")
			}
			// Reconstruct the original chain order and ensure we're banning the correct blocks
			types.BlockBy(types.Number).Sort(blocks)
			if bytes.Compare(blocks[0].Hash().Bytes(), head.Bytes()) != 0 {
				return errors.New("head block not the banned one")
			}
			index := 0
			for _, block := range blocks[1:] {
				if bytes.Compare(block.ParentHash().Bytes(), blocks[index].Hash().Bytes()) != 0 {
					break
				}
				index++
			}
			// Ban the head hash and phase out any excess
			d.banned.Add(blocks[index].Hash())
			for d.banned.Size() > maxBannedHashes {
				var evacuate common.Hash

				d.banned.Each(func(item interface{}) bool {
					// Skip any hard coded bans
					if core.BadHashes[item.(common.Hash)] {
						return true
					}
					evacuate = item.(common.Hash)
					return false
				})
				d.banned.Remove(evacuate)
			}
			glog.V(logger.Debug).Infof("Banned %d blocks from: %s", index+1, peerId)
			return nil
		}
	}
}