plugeth/eth/handler_eth.go

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// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package eth
import (
"errors"
"fmt"
"math/big"
"sync/atomic"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/eth/protocols/eth"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/p2p/enode"
"github.com/ethereum/go-ethereum/trie"
)
// ethHandler implements the eth.Backend interface to handle the various network
// packets that are sent as replies or broadcasts.
type ethHandler handler
func (h *ethHandler) Chain() *core.BlockChain { return h.chain }
func (h *ethHandler) StateBloom() *trie.SyncBloom { return h.stateBloom }
func (h *ethHandler) TxPool() eth.TxPool { return h.txpool }
// RunPeer is invoked when a peer joins on the `eth` protocol.
func (h *ethHandler) RunPeer(peer *eth.Peer, hand eth.Handler) error {
return (*handler)(h).runEthPeer(peer, hand)
}
// PeerInfo retrieves all known `eth` information about a peer.
func (h *ethHandler) PeerInfo(id enode.ID) interface{} {
if p := h.peers.peer(id.String()); p != nil {
return p.info()
}
return nil
}
// AcceptTxs retrieves whether transaction processing is enabled on the node
// or if inbound transactions should simply be dropped.
func (h *ethHandler) AcceptTxs() bool {
return atomic.LoadUint32(&h.acceptTxs) == 1
}
// Handle is invoked from a peer's message handler when it receives a new remote
// message that the handler couldn't consume and serve itself.
func (h *ethHandler) Handle(peer *eth.Peer, packet eth.Packet) error {
// Consume any broadcasts and announces, forwarding the rest to the downloader
switch packet := packet.(type) {
case *eth.BlockHeadersPacket:
return h.handleHeaders(peer, *packet)
case *eth.BlockBodiesPacket:
txset, uncleset := packet.Unpack()
return h.handleBodies(peer, txset, uncleset)
case *eth.NodeDataPacket:
if err := h.downloader.DeliverNodeData(peer.ID(), *packet); err != nil {
log.Debug("Failed to deliver node state data", "err", err)
}
return nil
case *eth.ReceiptsPacket:
if err := h.downloader.DeliverReceipts(peer.ID(), *packet); err != nil {
log.Debug("Failed to deliver receipts", "err", err)
}
return nil
case *eth.NewBlockHashesPacket:
hashes, numbers := packet.Unpack()
return h.handleBlockAnnounces(peer, hashes, numbers)
case *eth.NewBlockPacket:
return h.handleBlockBroadcast(peer, packet.Block, packet.TD)
case *eth.NewPooledTransactionHashesPacket:
return h.txFetcher.Notify(peer.ID(), *packet)
case *eth.TransactionsPacket:
return h.txFetcher.Enqueue(peer.ID(), *packet, false)
case *eth.PooledTransactionsPacket:
return h.txFetcher.Enqueue(peer.ID(), *packet, true)
default:
return fmt.Errorf("unexpected eth packet type: %T", packet)
}
}
// handleHeaders is invoked from a peer's message handler when it transmits a batch
// of headers for the local node to process.
func (h *ethHandler) handleHeaders(peer *eth.Peer, headers []*types.Header) error {
p := h.peers.peer(peer.ID())
if p == nil {
return errors.New("unregistered during callback")
}
// If no headers were received, but we're expencting a checkpoint header, consider it that
if len(headers) == 0 && p.syncDrop != nil {
// Stop the timer either way, decide later to drop or not
p.syncDrop.Stop()
p.syncDrop = nil
// If we're doing a fast (or snap) sync, we must enforce the checkpoint block to avoid
// eclipse attacks. Unsynced nodes are welcome to connect after we're done
// joining the network
if atomic.LoadUint32(&h.fastSync) == 1 {
peer.Log().Warn("Dropping unsynced node during sync", "addr", peer.RemoteAddr(), "type", peer.Name())
return errors.New("unsynced node cannot serve sync")
}
}
// Filter out any explicitly requested headers, deliver the rest to the downloader
filter := len(headers) == 1
if filter {
// If it's a potential sync progress check, validate the content and advertised chain weight
if p.syncDrop != nil && headers[0].Number.Uint64() == h.checkpointNumber {
// Disable the sync drop timer
p.syncDrop.Stop()
p.syncDrop = nil
// Validate the header and either drop the peer or continue
if headers[0].Hash() != h.checkpointHash {
return errors.New("checkpoint hash mismatch")
}
return nil
}
// Otherwise if it's a whitelisted block, validate against the set
if want, ok := h.whitelist[headers[0].Number.Uint64()]; ok {
if hash := headers[0].Hash(); want != hash {
peer.Log().Info("Whitelist mismatch, dropping peer", "number", headers[0].Number.Uint64(), "hash", hash, "want", want)
return errors.New("whitelist block mismatch")
}
peer.Log().Debug("Whitelist block verified", "number", headers[0].Number.Uint64(), "hash", want)
}
// Irrelevant of the fork checks, send the header to the fetcher just in case
headers = h.blockFetcher.FilterHeaders(peer.ID(), headers, time.Now())
}
if len(headers) > 0 || !filter {
err := h.downloader.DeliverHeaders(peer.ID(), headers)
if err != nil {
log.Debug("Failed to deliver headers", "err", err)
}
}
return nil
}
// handleBodies is invoked from a peer's message handler when it transmits a batch
// of block bodies for the local node to process.
func (h *ethHandler) handleBodies(peer *eth.Peer, txs [][]*types.Transaction, uncles [][]*types.Header) error {
// Filter out any explicitly requested bodies, deliver the rest to the downloader
filter := len(txs) > 0 || len(uncles) > 0
if filter {
txs, uncles = h.blockFetcher.FilterBodies(peer.ID(), txs, uncles, time.Now())
}
if len(txs) > 0 || len(uncles) > 0 || !filter {
err := h.downloader.DeliverBodies(peer.ID(), txs, uncles)
if err != nil {
log.Debug("Failed to deliver bodies", "err", err)
}
}
return nil
}
// handleBlockAnnounces is invoked from a peer's message handler when it transmits a
// batch of block announcements for the local node to process.
func (h *ethHandler) handleBlockAnnounces(peer *eth.Peer, hashes []common.Hash, numbers []uint64) error {
// Schedule all the unknown hashes for retrieval
var (
unknownHashes = make([]common.Hash, 0, len(hashes))
unknownNumbers = make([]uint64, 0, len(numbers))
)
for i := 0; i < len(hashes); i++ {
if !h.chain.HasBlock(hashes[i], numbers[i]) {
unknownHashes = append(unknownHashes, hashes[i])
unknownNumbers = append(unknownNumbers, numbers[i])
}
}
for i := 0; i < len(unknownHashes); i++ {
h.blockFetcher.Notify(peer.ID(), unknownHashes[i], unknownNumbers[i], time.Now(), peer.RequestOneHeader, peer.RequestBodies)
}
return nil
}
// handleBlockBroadcast is invoked from a peer's message handler when it transmits a
// block broadcast for the local node to process.
func (h *ethHandler) handleBlockBroadcast(peer *eth.Peer, block *types.Block, td *big.Int) error {
// Schedule the block for import
h.blockFetcher.Enqueue(peer.ID(), block)
// Assuming the block is importable by the peer, but possibly not yet done so,
// calculate the head hash and TD that the peer truly must have.
var (
trueHead = block.ParentHash()
trueTD = new(big.Int).Sub(td, block.Difficulty())
)
// Update the peer's total difficulty if better than the previous
if _, td := peer.Head(); trueTD.Cmp(td) > 0 {
peer.SetHead(trueHead, trueTD)
h.chainSync.handlePeerEvent(peer)
}
return nil
}