github.com/intfoundation/intchain@v0.0.0-20220727031208-4316ad31ca73/p2p/enr/entries.go (about)

     1  // Copyright 2017 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 enr
    18  
    19  import (
    20  	"crypto/ecdsa"
    21  	"fmt"
    22  	"io"
    23  	"net"
    24  
    25  	"github.com/intfoundation/intchain/crypto"
    26  	"github.com/intfoundation/intchain/rlp"
    27  )
    28  
    29  // Entry is implemented by known node record entry types.
    30  //
    31  // To define a new entry that is to be included in a node record,
    32  // create a Go type that satisfies this interface. The type should
    33  // also implement rlp.Decoder if additional checks are needed on the value.
    34  type Entry interface {
    35  	ENRKey() string
    36  }
    37  
    38  type generic struct {
    39  	key   string
    40  	value interface{}
    41  }
    42  
    43  func (g generic) ENRKey() string { return g.key }
    44  
    45  func (g generic) EncodeRLP(w io.Writer) error {
    46  	return rlp.Encode(w, g.value)
    47  }
    48  
    49  func (g *generic) DecodeRLP(s *rlp.Stream) error {
    50  	return s.Decode(g.value)
    51  }
    52  
    53  // WithEntry wraps any value with a key name. It can be used to set and load arbitrary values
    54  // in a record. The value v must be supported by rlp. To use WithEntry with Load, the value
    55  // must be a pointer.
    56  func WithEntry(k string, v interface{}) Entry {
    57  	return &generic{key: k, value: v}
    58  }
    59  
    60  // DiscPort is the "discv5" key, which holds the UDP port for discovery v5.
    61  type DiscPort uint16
    62  
    63  func (v DiscPort) ENRKey() string { return "discv5" }
    64  
    65  // ID is the "id" key, which holds the name of the identity scheme.
    66  type ID string
    67  
    68  func (v ID) ENRKey() string { return "id" }
    69  
    70  // IP4 is the "ip4" key, which holds a 4-byte IPv4 address.
    71  type IP4 net.IP
    72  
    73  func (v IP4) ENRKey() string { return "ip4" }
    74  
    75  // EncodeRLP implements rlp.Encoder.
    76  func (v IP4) EncodeRLP(w io.Writer) error {
    77  	ip4 := net.IP(v).To4()
    78  	if ip4 == nil {
    79  		return fmt.Errorf("invalid IPv4 address: %v", v)
    80  	}
    81  	return rlp.Encode(w, ip4)
    82  }
    83  
    84  // DecodeRLP implements rlp.Decoder.
    85  func (v *IP4) DecodeRLP(s *rlp.Stream) error {
    86  	if err := s.Decode((*net.IP)(v)); err != nil {
    87  		return err
    88  	}
    89  	if len(*v) != 4 {
    90  		return fmt.Errorf("invalid IPv4 address, want 4 bytes: %v", *v)
    91  	}
    92  	return nil
    93  }
    94  
    95  // IP6 is the "ip6" key, which holds a 16-byte IPv6 address.
    96  type IP6 net.IP
    97  
    98  func (v IP6) ENRKey() string { return "ip6" }
    99  
   100  // EncodeRLP implements rlp.Encoder.
   101  func (v IP6) EncodeRLP(w io.Writer) error {
   102  	ip6 := net.IP(v)
   103  	return rlp.Encode(w, ip6)
   104  }
   105  
   106  // DecodeRLP implements rlp.Decoder.
   107  func (v *IP6) DecodeRLP(s *rlp.Stream) error {
   108  	if err := s.Decode((*net.IP)(v)); err != nil {
   109  		return err
   110  	}
   111  	if len(*v) != 16 {
   112  		return fmt.Errorf("invalid IPv6 address, want 16 bytes: %v", *v)
   113  	}
   114  	return nil
   115  }
   116  
   117  // Secp256k1 is the "secp256k1" key, which holds a public key.
   118  type Secp256k1 ecdsa.PublicKey
   119  
   120  func (v Secp256k1) ENRKey() string { return "secp256k1" }
   121  
   122  // EncodeRLP implements rlp.Encoder.
   123  func (v Secp256k1) EncodeRLP(w io.Writer) error {
   124  	return rlp.Encode(w, crypto.CompressPubkey((*ecdsa.PublicKey)(&v)))
   125  }
   126  
   127  // DecodeRLP implements rlp.Decoder.
   128  func (v *Secp256k1) DecodeRLP(s *rlp.Stream) error {
   129  	buf, err := s.Bytes()
   130  	if err != nil {
   131  		return err
   132  	}
   133  	pk, err := crypto.DecompressPubkey(buf)
   134  	if err != nil {
   135  		return err
   136  	}
   137  	*v = (Secp256k1)(*pk)
   138  	return nil
   139  }
   140  
   141  // KeyError is an error related to a key.
   142  type KeyError struct {
   143  	Key string
   144  	Err error
   145  }
   146  
   147  // Error implements error.
   148  func (err *KeyError) Error() string {
   149  	if err.Err == errNotFound {
   150  		return fmt.Sprintf("missing ENR key %q", err.Key)
   151  	}
   152  	return fmt.Sprintf("ENR key %q: %v", err.Key, err.Err)
   153  }
   154  
   155  // IsNotFound reports whether the given error means that a key/value pair is
   156  // missing from a record.
   157  func IsNotFound(err error) bool {
   158  	kerr, ok := err.(*KeyError)
   159  	return ok && kerr.Err == errNotFound
   160  }