eth: enable bad block reports

We used to have reporting of bad blocks, but it was disabled
before the Frontier release. We need it back because users
are usually unable to provide the full RLP data of a bad
block when it occurs.

A shortcoming of this particular implementation is that the
origin peer is not tracked for blocks received during eth/63
sync. No origin peer info is still better than no report at
all though.

2 files changed, 93 insertions, 2 deletions

diff --git a/eth/bad_block.go b/eth/bad_block.go
new file mode 100644
index 000000000..3a6c3d85c
--- /dev/null
+++ b/eth/bad_block.go
@@ -0,0 +1,74 @@
+// 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 (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/logger"
+	"github.com/ethereum/go-ethereum/logger/glog"
+	"github.com/ethereum/go-ethereum/rlp"
+)
+
+const (
+	// The Ethereum main network genesis block.
+	defaultGenesisHash = "0xd4e56740f876aef8c010b86a40d5f56745a118d0906a34e69aec8c0db1cb8fa3"
+	badBlocksURL       = "https://badblocks.ethdev.com"
+)
+
+var EnableBadBlockReporting = false
+
+func sendBadBlockReport(block *types.Block, err error) {
+	if !EnableBadBlockReporting {
+		return
+	}
+
+	var (
+		blockRLP, _ = rlp.EncodeToBytes(block)
+		params      = map[string]interface{}{
+			"block":     common.Bytes2Hex(blockRLP),
+			"blockHash": block.Hash().Hex(),
+			"errortype": err.Error(),
+			"client":    "go",
+		}
+	)
+	if !block.ReceivedAt.IsZero() {
+		params["receivedAt"] = block.ReceivedAt.UTC().String()
+	}
+	if p, ok := block.ReceivedFrom.(*peer); ok {
+		params["receivedFrom"] = map[string]interface{}{
+			"enode":           fmt.Sprintf("enode://%x@%v", p.ID(), p.RemoteAddr()),
+			"name":            p.Name(),
+			"protocolVersion": p.version,
+		}
+	}
+	jsonStr, _ := json.Marshal(map[string]interface{}{"method": "eth_badBlock", "id": "1", "jsonrpc": "2.0", "params": []interface{}{params}})
+	client := http.Client{Timeout: 8 * time.Second}
+	resp, err := client.Post(badBlocksURL, "application/json", bytes.NewReader(jsonStr))
+	if err != nil {
+		glog.V(logger.Debug).Infoln(err)
+		return
+	}
+	glog.V(logger.Debug).Infof("Bad Block Report posted (%d)", resp.StatusCode)
+	resp.Body.Close()
+}
diff --git a/eth/handler.go b/eth/handler.go
index 202acdc78..58869a2ee 100644
--- a/eth/handler.go
+++ b/eth/handler.go
@@ -83,6 +83,8 @@ type ProtocolManager struct {
 	// wait group is used for graceful shutdowns during downloading
 	// and processing
 	wg sync.WaitGroup
+
+	badBlockReportingEnabled bool
 }
 
 // NewProtocolManager returns a new ethereum sub protocol manager. The Ethereum sub protocol manages peers capable
@@ -150,7 +152,7 @@ func NewProtocolManager(config *core.ChainConfig, fastSync bool, networkId int,
 	// Construct the different synchronisation mechanisms
 	manager.downloader = downloader.New(chaindb, manager.eventMux, blockchain.HasHeader, blockchain.HasBlockAndState, blockchain.GetHeader,
 		blockchain.GetBlock, blockchain.CurrentHeader, blockchain.CurrentBlock, blockchain.CurrentFastBlock, blockchain.FastSyncCommitHead,
-		blockchain.GetTd, blockchain.InsertHeaderChain, blockchain.InsertChain, blockchain.InsertReceiptChain, blockchain.Rollback,
+		blockchain.GetTd, blockchain.InsertHeaderChain, manager.insertChain, blockchain.InsertReceiptChain, blockchain.Rollback,
 		manager.removePeer)
 
 	validator := func(block *types.Block, parent *types.Block) error {
@@ -159,11 +161,24 @@ func NewProtocolManager(config *core.ChainConfig, fastSync bool, networkId int,
 	heighter := func() uint64 {
 		return blockchain.CurrentBlock().NumberU64()
 	}
-	manager.fetcher = fetcher.New(blockchain.GetBlock, validator, manager.BroadcastBlock, heighter, blockchain.InsertChain, manager.removePeer)
+	manager.fetcher = fetcher.New(blockchain.GetBlock, validator, manager.BroadcastBlock, heighter, manager.insertChain, manager.removePeer)
+
+	if blockchain.Genesis().Hash().Hex() == defaultGenesisHash && networkId == 1 {
+		glog.V(logger.Debug).Infoln("Bad Block Reporting is enabled")
+		manager.badBlockReportingEnabled = true
+	}
 
 	return manager, nil
 }
 
+func (pm *ProtocolManager) insertChain(blocks types.Blocks) (i int, err error) {
+	i, err = pm.blockchain.InsertChain(blocks)
+	if pm.badBlockReportingEnabled && core.IsValidationErr(err) && i < len(blocks) {
+		go sendBadBlockReport(blocks[i], err)
+	}
+	return i, err
+}
+
 func (pm *ProtocolManager) removePeer(id string) {
 	// Short circuit if the peer was already removed
 	peer := pm.peers.Peer(id)
@@ -378,6 +393,7 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 		// Update the receive timestamp of each block
 		for _, block := range blocks {
 			block.ReceivedAt = msg.ReceivedAt
+			block.ReceivedFrom = p
 		}
 		// Filter out any explicitly requested blocks, deliver the rest to the downloader
 		if blocks := pm.fetcher.FilterBlocks(blocks); len(blocks) > 0 {
@@ -664,6 +680,7 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 			return errResp(ErrDecode, "block validation %v: %v", msg, err)
 		}
 		request.Block.ReceivedAt = msg.ReceivedAt
+		request.Block.ReceivedFrom = p
 
 		// Mark the peer as owning the block and schedule it for import
 		p.MarkBlock(request.Block.Hash())