github.com/anthdm/go-ethereum@v1.8.4-0.20180412101906-60516c83b011/cmd/bootnode/main.go (about)

     1  // Copyright 2015 The go-ethereum Authors
     2  // This file is part of go-ethereum.
     3  //
     4  // go-ethereum is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // go-ethereum is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU General Public License
    15  // along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  // bootnode runs a bootstrap node for the Ethereum Discovery Protocol.
    18  package main
    19  
    20  import (
    21  	"crypto/ecdsa"
    22  	"flag"
    23  	"fmt"
    24  	"net"
    25  	"os"
    26  
    27  	"github.com/ethereum/go-ethereum/cmd/utils"
    28  	"github.com/ethereum/go-ethereum/crypto"
    29  	"github.com/ethereum/go-ethereum/log"
    30  	"github.com/ethereum/go-ethereum/p2p/discover"
    31  	"github.com/ethereum/go-ethereum/p2p/discv5"
    32  	"github.com/ethereum/go-ethereum/p2p/nat"
    33  	"github.com/ethereum/go-ethereum/p2p/netutil"
    34  )
    35  
    36  func main() {
    37  	var (
    38  		listenAddr  = flag.String("addr", ":30301", "listen address")
    39  		genKey      = flag.String("genkey", "", "generate a node key")
    40  		writeAddr   = flag.Bool("writeaddress", false, "write out the node's pubkey hash and quit")
    41  		nodeKeyFile = flag.String("nodekey", "", "private key filename")
    42  		nodeKeyHex  = flag.String("nodekeyhex", "", "private key as hex (for testing)")
    43  		natdesc     = flag.String("nat", "none", "port mapping mechanism (any|none|upnp|pmp|extip:<IP>)")
    44  		netrestrict = flag.String("netrestrict", "", "restrict network communication to the given IP networks (CIDR masks)")
    45  		runv5       = flag.Bool("v5", false, "run a v5 topic discovery bootnode")
    46  		verbosity   = flag.Int("verbosity", int(log.LvlInfo), "log verbosity (0-9)")
    47  		vmodule     = flag.String("vmodule", "", "log verbosity pattern")
    48  
    49  		nodeKey *ecdsa.PrivateKey
    50  		err     error
    51  	)
    52  	flag.Parse()
    53  
    54  	glogger := log.NewGlogHandler(log.StreamHandler(os.Stderr, log.TerminalFormat(false)))
    55  	glogger.Verbosity(log.Lvl(*verbosity))
    56  	glogger.Vmodule(*vmodule)
    57  	log.Root().SetHandler(glogger)
    58  
    59  	natm, err := nat.Parse(*natdesc)
    60  	if err != nil {
    61  		utils.Fatalf("-nat: %v", err)
    62  	}
    63  	switch {
    64  	case *genKey != "":
    65  		nodeKey, err = crypto.GenerateKey()
    66  		if err != nil {
    67  			utils.Fatalf("could not generate key: %v", err)
    68  		}
    69  		if err = crypto.SaveECDSA(*genKey, nodeKey); err != nil {
    70  			utils.Fatalf("%v", err)
    71  		}
    72  		return
    73  	case *nodeKeyFile == "" && *nodeKeyHex == "":
    74  		utils.Fatalf("Use -nodekey or -nodekeyhex to specify a private key")
    75  	case *nodeKeyFile != "" && *nodeKeyHex != "":
    76  		utils.Fatalf("Options -nodekey and -nodekeyhex are mutually exclusive")
    77  	case *nodeKeyFile != "":
    78  		if nodeKey, err = crypto.LoadECDSA(*nodeKeyFile); err != nil {
    79  			utils.Fatalf("-nodekey: %v", err)
    80  		}
    81  	case *nodeKeyHex != "":
    82  		if nodeKey, err = crypto.HexToECDSA(*nodeKeyHex); err != nil {
    83  			utils.Fatalf("-nodekeyhex: %v", err)
    84  		}
    85  	}
    86  
    87  	if *writeAddr {
    88  		fmt.Printf("%v\n", discover.PubkeyID(&nodeKey.PublicKey))
    89  		os.Exit(0)
    90  	}
    91  
    92  	var restrictList *netutil.Netlist
    93  	if *netrestrict != "" {
    94  		restrictList, err = netutil.ParseNetlist(*netrestrict)
    95  		if err != nil {
    96  			utils.Fatalf("-netrestrict: %v", err)
    97  		}
    98  	}
    99  
   100  	addr, err := net.ResolveUDPAddr("udp", *listenAddr)
   101  	if err != nil {
   102  		utils.Fatalf("-ResolveUDPAddr: %v", err)
   103  	}
   104  	conn, err := net.ListenUDP("udp", addr)
   105  	if err != nil {
   106  		utils.Fatalf("-ListenUDP: %v", err)
   107  	}
   108  
   109  	realaddr := conn.LocalAddr().(*net.UDPAddr)
   110  	if natm != nil {
   111  		if !realaddr.IP.IsLoopback() {
   112  			go nat.Map(natm, nil, "udp", realaddr.Port, realaddr.Port, "ethereum discovery")
   113  		}
   114  		// TODO: react to external IP changes over time.
   115  		if ext, err := natm.ExternalIP(); err == nil {
   116  			realaddr = &net.UDPAddr{IP: ext, Port: realaddr.Port}
   117  		}
   118  	}
   119  
   120  	if *runv5 {
   121  		if _, err := discv5.ListenUDP(nodeKey, conn, realaddr, "", restrictList); err != nil {
   122  			utils.Fatalf("%v", err)
   123  		}
   124  	} else {
   125  		cfg := discover.Config{
   126  			PrivateKey:   nodeKey,
   127  			AnnounceAddr: realaddr,
   128  			NetRestrict:  restrictList,
   129  		}
   130  		if _, err := discover.ListenUDP(conn, cfg); err != nil {
   131  			utils.Fatalf("%v", err)
   132  		}
   133  	}
   134  
   135  	select {}
   136  }