cmd, eth: flag for enabling eth protocol versions

cmd/geth/main.go

@@ -284,6 +284,7 @@ JavaScript API. See https://github.com/ethereum/go-ethereum/wiki/Javascipt-Conso
 		utils.DataDirFlag,
 		utils.BlockchainVersionFlag,
 		utils.OlympicFlag,
+		utils.EthVersionFlag,
 		utils.CacheFlag,
 		utils.JSpathFlag,
 		utils.ListenPortFlag,
@@ -334,6 +335,7 @@ JavaScript API. See https://github.com/ethereum/go-ethereum/wiki/Javascipt-Conso
 	app.Before = func(ctx *cli.Context) error {
 		utils.SetupLogger(ctx)
 		utils.SetupVM(ctx)
+		utils.SetupEth(ctx)
 		if ctx.GlobalBool(utils.PProfEanbledFlag.Name) {
 			utils.StartPProf(ctx)
 		}

cmd/utils/flags.go

@@ -138,6 +138,11 @@ var (
 		Name:  "olympic",
 		Usage: "Use olympic style protocol",
 	}
+	EthVersionFlag = cli.IntFlag{
+		Name:  "eth",
+		Value: 61,
+		Usage: "Highest eth protocol to advertise (temporary, dev option)",
+	}
 
 	// miner settings
 	MinerThreadsFlag = cli.IntFlag{
@@ -459,6 +464,18 @@ func SetupVM(ctx *cli.Context) {
 	vm.SetJITCacheSize(ctx.GlobalInt(VMJitCacheFlag.Name))
 }
 
+// SetupEth configures the eth packages global settings
+func SetupEth(ctx *cli.Context) {
+	version := ctx.GlobalInt(EthVersionFlag.Name)
+	for len(eth.ProtocolVersions) > 0 && eth.ProtocolVersions[0] > uint(version) {
+		eth.ProtocolVersions = eth.ProtocolVersions[1:]
+		eth.ProtocolLengths = eth.ProtocolLengths[1:]
+	}
+	if len(eth.ProtocolVersions) == 0 {
+		Fatalf("No valid eth protocols remaining")
+	}
+}
+
 // MakeChain creates a chain manager from set command line flags.
 func MakeChain(ctx *cli.Context) (chain *core.ChainManager, chainDb common.Database) {
 	datadir := ctx.GlobalString(DataDirFlag.Name)

eth/protocol.go

@@ -36,10 +36,10 @@ const (
 )
 
 // Supported versions of the eth protocol (first is primary).
-var ProtocolVersions = []uint{61, 60}
+var ProtocolVersions = []uint{eth64, eth63, eth62, eth61, eth60}
 
 // Number of implemented message corresponding to different protocol versions.
-var ProtocolLengths = []uint64{9, 8}
+var ProtocolLengths = []uint64{15, 12, 8, 9, 8}
 
 const (
 	NetworkId          = 1
@@ -69,6 +69,7 @@ const (
 	BlockHeadersMsg    = 0x04
 	GetBlockBodiesMsg  = 0x05
 	BlockBodiesMsg     = 0x06
+	// 	NewBlockMsg       = 0x07 (uncomment after eth/61 deprecation)
 
 	// Protocol messages belonging to eth/63
 	GetNodeDataMsg = 0x0d