From 785b3e7a575f26f3c33e3369d8a75fb131f90584 Mon Sep 17 00:00:00 2001
From: Jeffrey Wilcke <geffobscura@gmail.com>
Date: Thu, 6 Aug 2015 11:20:15 +0200
Subject: [PATCH] cmd/geth, eth: added canonical extra data

Implemented canonical extra data according to
https://github.com/ethereum/wiki/wiki/Extra-Data
---
 cmd/geth/main.go | 32 ++++++++++++++++++++++++++++++--
 eth/backend.go   |  9 ++-------
 2 files changed, 32 insertions(+), 9 deletions(-)

diff --git a/cmd/geth/main.go b/cmd/geth/main.go
index 74f4e90c3a..ddfa8e661f 100644
--- a/cmd/geth/main.go
+++ b/cmd/geth/main.go
@@ -42,6 +42,8 @@ import (
 	"github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/logger/glog"
 	"github.com/ethereum/go-ethereum/metrics"
+	"github.com/ethereum/go-ethereum/params"
+	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/ethereum/go-ethereum/rpc/codec"
 	"github.com/ethereum/go-ethereum/rpc/comms"
 	"github.com/mattn/go-colorable"
@@ -49,11 +51,14 @@ import (
 )
 
 const (
-	ClientIdentifier = "Geth"
-	Version          = "1.0.1"
+	ClientIdentifier = "Geth                                                                                                   "
+	VersionMajor     = 1
+	VersionMinor     = 0
+	VersionPatch     = 1
 )
 
 var (
+	Version         = fmt.Sprintf("%d.%d.%d", VersionMajor, VersionMinor, VersionPatch)
 	gitCommit       string // set via linker flagg
 	nodeNameVersion string
 	app             *cli.App
@@ -346,6 +351,27 @@ func main() {
 	}
 }
 
+func makeDefaultExtra() []byte {
+	var clientInfo = struct {
+		Version   uint
+		Name      string
+		GoVersion string
+		Os        string
+	}{uint(VersionMajor<<16 | VersionMinor<<8 | VersionPatch), ClientIdentifier, runtime.Version(), runtime.GOOS}
+	extra, err := rlp.EncodeToBytes(clientInfo)
+	if err != nil {
+		glog.V(logger.Warn).Infoln("error setting canonical miner information:", err)
+	}
+
+	if uint64(len(extra)) > params.MaximumExtraDataSize.Uint64() {
+		glog.V(logger.Warn).Infoln("error setting canonical miner information: extra exceeds", params.MaximumExtraDataSize)
+		glog.V(logger.Debug).Infof("extra: %x\n", extra)
+		return nil
+	}
+
+	return extra
+}
+
 func run(ctx *cli.Context) {
 	utils.CheckLegalese(ctx.GlobalString(utils.DataDirFlag.Name))
 	if ctx.GlobalBool(utils.OlympicFlag.Name) {
@@ -353,6 +379,8 @@ func run(ctx *cli.Context) {
 	}
 
 	cfg := utils.MakeEthConfig(ClientIdentifier, nodeNameVersion, ctx)
+	cfg.ExtraData = makeDefaultExtra()
+
 	ethereum, err := eth.New(cfg)
 	if err != nil {
 		utils.Fatalf("%v", err)
diff --git a/eth/backend.go b/eth/backend.go
index 4795000e09..ed46a4ab36 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -45,7 +45,6 @@ import (
 	"github.com/ethereum/go-ethereum/p2p"
 	"github.com/ethereum/go-ethereum/p2p/discover"
 	"github.com/ethereum/go-ethereum/p2p/nat"
-	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/whisper"
 )
 
@@ -92,6 +91,7 @@ type Config struct {
 	NatSpec   bool
 	AutoDAG   bool
 	PowTest   bool
+	ExtraData []byte
 
 	MaxPeers        int
 	MaxPendingPeers int
@@ -378,12 +378,7 @@ func New(config *Config) (*Ethereum, error) {
 
 	eth.miner = miner.New(eth, eth.EventMux(), eth.pow)
 	eth.miner.SetGasPrice(config.GasPrice)
-
-	extra := config.Name
-	if uint64(len(extra)) > params.MaximumExtraDataSize.Uint64() {
-		extra = extra[:params.MaximumExtraDataSize.Uint64()]
-	}
-	eth.miner.SetExtra([]byte(extra))
+	eth.miner.SetExtra(config.ExtraData)
 
 	if config.Shh {
 		eth.whisper = whisper.New()