github.com/amazechain/amc@v0.1.3/internal/p2p/discover/common.go (about)

     1  // Copyright 2019 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser 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  // The go-ethereum library 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 Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package discover
    18  
    19  import (
    20  	"crypto/ecdsa"
    21  	"github.com/amazechain/amc/common/mclock"
    22  	"github.com/amazechain/amc/internal/p2p/enode"
    23  	"github.com/amazechain/amc/internal/p2p/enr"
    24  	"github.com/amazechain/amc/internal/p2p/netutil"
    25  	"github.com/amazechain/amc/log"
    26  	"net"
    27  )
    28  
    29  // UDPConn is a network connection on which discovery can operate.
    30  type UDPConn interface {
    31  	ReadFromUDP(b []byte) (n int, addr *net.UDPAddr, err error)
    32  	WriteToUDP(b []byte, addr *net.UDPAddr) (n int, err error)
    33  	Close() error
    34  	LocalAddr() net.Addr
    35  }
    36  
    37  type V5Config struct {
    38  	ProtocolID *[6]byte
    39  }
    40  
    41  // Config holds settings for the discovery listener.
    42  type Config struct {
    43  	// These settings are required and configure the UDP listener:
    44  	PrivateKey *ecdsa.PrivateKey
    45  
    46  	// These settings are optional:
    47  	NetRestrict *netutil.Netlist  // list of allowed IP networks
    48  	Bootnodes   []*enode.Node     // list of bootstrap nodes
    49  	Unhandled   chan<- ReadPacket // unhandled packets are sent on this channel
    50  	Log         log.Logger        // if set, log messages go here
    51  
    52  	// V5ProtocolID configures the discv5 protocol identifier.
    53  	V5ProtocolID *[6]byte
    54  
    55  	ValidSchemes enr.IdentityScheme // allowed identity schemes
    56  	Clock        mclock.Clock
    57  }
    58  
    59  func (cfg Config) withDefaults() Config {
    60  	if cfg.Log == nil {
    61  		cfg.Log = log.Root()
    62  	}
    63  	if cfg.ValidSchemes == nil {
    64  		cfg.ValidSchemes = enode.ValidSchemes
    65  	}
    66  	if cfg.Clock == nil {
    67  		cfg.Clock = mclock.System{}
    68  	}
    69  	return cfg
    70  }
    71  
    72  // ListenUDP starts listening for discovery packets on the given UDP socket.
    73  func ListenUDP(c UDPConn, ln *enode.LocalNode, cfg Config) (*UDPv4, error) {
    74  	return ListenV4(c, ln, cfg)
    75  }
    76  
    77  // ReadPacket is a packet that couldn't be handled. Those packets are sent to the unhandled
    78  // channel if configured.
    79  type ReadPacket struct {
    80  	Data []byte
    81  	Addr *net.UDPAddr
    82  }
    83  
    84  func min(x, y int) int {
    85  	if x > y {
    86  		return y
    87  	}
    88  	return x
    89  }