github.com/jonasnick/go-ethereum@v0.7.12-0.20150216215225-22176f05d387/cmd/bootnode/main.go (about)

     1  /*
     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  
    18  // Command bootnode runs a bootstrap node for the Discovery Protocol.
    19  package main
    20  
    21  import (
    22  	"crypto/ecdsa"
    23  	"encoding/hex"
    24  	"flag"
    25  	"fmt"
    26  	"io/ioutil"
    27  	"log"
    28  	"os"
    29  
    30  	"github.com/jonasnick/go-ethereum/crypto"
    31  	"github.com/jonasnick/go-ethereum/logger"
    32  	"github.com/jonasnick/go-ethereum/p2p/discover"
    33  	"github.com/jonasnick/go-ethereum/p2p/nat"
    34  )
    35  
    36  func main() {
    37  	var (
    38  		listenAddr  = flag.String("addr", ":30301", "listen address")
    39  		genKey      = flag.String("genkey", "", "generate a node key and quit")
    40  		nodeKeyFile = flag.String("nodekey", "", "private key filename")
    41  		nodeKeyHex  = flag.String("nodekeyhex", "", "private key as hex (for testing)")
    42  		natdesc     = flag.String("nat", "none", "port mapping mechanism (any|none|upnp|pmp|extip:<IP>)")
    43  
    44  		nodeKey *ecdsa.PrivateKey
    45  		err     error
    46  	)
    47  	flag.Parse()
    48  	logger.AddLogSystem(logger.NewStdLogSystem(os.Stdout, log.LstdFlags, logger.DebugLevel))
    49  
    50  	if *genKey != "" {
    51  		writeKey(*genKey)
    52  		os.Exit(0)
    53  	}
    54  
    55  	natm, err := nat.Parse(*natdesc)
    56  	if err != nil {
    57  		log.Fatalf("-nat: %v", err)
    58  	}
    59  	switch {
    60  	case *nodeKeyFile == "" && *nodeKeyHex == "":
    61  		log.Fatal("Use -nodekey or -nodekeyhex to specify a private key")
    62  	case *nodeKeyFile != "" && *nodeKeyHex != "":
    63  		log.Fatal("Options -nodekey and -nodekeyhex are mutually exclusive")
    64  	case *nodeKeyFile != "":
    65  		if nodeKey, err = crypto.LoadECDSA(*nodeKeyFile); err != nil {
    66  			log.Fatalf("-nodekey: %v", err)
    67  		}
    68  	case *nodeKeyHex != "":
    69  		if nodeKey, err = crypto.HexToECDSA(*nodeKeyHex); err != nil {
    70  			log.Fatalf("-nodekeyhex: %v", err)
    71  		}
    72  	}
    73  
    74  	if _, err := discover.ListenUDP(nodeKey, *listenAddr, natm); err != nil {
    75  		log.Fatal(err)
    76  	}
    77  	select {}
    78  }
    79  
    80  func writeKey(target string) {
    81  	key, err := crypto.GenerateKey()
    82  	if err != nil {
    83  		log.Fatal("could not generate key: %v", err)
    84  	}
    85  	b := crypto.FromECDSA(key)
    86  	if target == "-" {
    87  		fmt.Println(hex.EncodeToString(b))
    88  	} else {
    89  		if err := ioutil.WriteFile(target, b, 0600); err != nil {
    90  			log.Fatal("write error: ", err)
    91  		}
    92  	}
    93  }