github.com/daeglee/go-ethereum@v0.0.0-20190504220456-cad3e8d18e9b/p2p/discover/table_util_test.go (about)

     1  // Copyright 2015 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  	"encoding/hex"
    21  	"fmt"
    22  	"math/rand"
    23  	"net"
    24  	"sync"
    25  
    26  	"github.com/ethereum/go-ethereum/p2p/enode"
    27  	"github.com/ethereum/go-ethereum/p2p/enr"
    28  )
    29  
    30  var nullNode *enode.Node
    31  
    32  func init() {
    33  	var r enr.Record
    34  	r.Set(enr.IP{0, 0, 0, 0})
    35  	nullNode = enode.SignNull(&r, enode.ID{})
    36  }
    37  
    38  func newTestTable(t transport) (*Table, *enode.DB) {
    39  	db, _ := enode.OpenDB("")
    40  	tab, _ := newTable(t, db, nil)
    41  	return tab, db
    42  }
    43  
    44  // nodeAtDistance creates a node for which enode.LogDist(base, n.id) == ld.
    45  func nodeAtDistance(base enode.ID, ld int, ip net.IP) *node {
    46  	var r enr.Record
    47  	r.Set(enr.IP(ip))
    48  	return wrapNode(enode.SignNull(&r, idAtDistance(base, ld)))
    49  }
    50  
    51  // idAtDistance returns a random hash such that enode.LogDist(a, b) == n
    52  func idAtDistance(a enode.ID, n int) (b enode.ID) {
    53  	if n == 0 {
    54  		return a
    55  	}
    56  	// flip bit at position n, fill the rest with random bits
    57  	b = a
    58  	pos := len(a) - n/8 - 1
    59  	bit := byte(0x01) << (byte(n%8) - 1)
    60  	if bit == 0 {
    61  		pos++
    62  		bit = 0x80
    63  	}
    64  	b[pos] = a[pos]&^bit | ^a[pos]&bit // TODO: randomize end bits
    65  	for i := pos + 1; i < len(a); i++ {
    66  		b[i] = byte(rand.Intn(255))
    67  	}
    68  	return b
    69  }
    70  
    71  func intIP(i int) net.IP {
    72  	return net.IP{byte(i), 0, 2, byte(i)}
    73  }
    74  
    75  // fillBucket inserts nodes into the given bucket until it is full.
    76  func fillBucket(tab *Table, n *node) (last *node) {
    77  	ld := enode.LogDist(tab.self().ID(), n.ID())
    78  	b := tab.bucket(n.ID())
    79  	for len(b.entries) < bucketSize {
    80  		b.entries = append(b.entries, nodeAtDistance(tab.self().ID(), ld, intIP(ld)))
    81  	}
    82  	return b.entries[bucketSize-1]
    83  }
    84  
    85  // fillTable adds nodes the table to the end of their corresponding bucket
    86  // if the bucket is not full. The caller must not hold tab.mutex.
    87  func fillTable(tab *Table, nodes []*node) {
    88  	for _, n := range nodes {
    89  		tab.addSeenNode(n)
    90  	}
    91  }
    92  
    93  type pingRecorder struct {
    94  	mu           sync.Mutex
    95  	dead, pinged map[enode.ID]bool
    96  	n            *enode.Node
    97  }
    98  
    99  func newPingRecorder() *pingRecorder {
   100  	var r enr.Record
   101  	r.Set(enr.IP{0, 0, 0, 0})
   102  	n := enode.SignNull(&r, enode.ID{})
   103  
   104  	return &pingRecorder{
   105  		dead:   make(map[enode.ID]bool),
   106  		pinged: make(map[enode.ID]bool),
   107  		n:      n,
   108  	}
   109  }
   110  
   111  func (t *pingRecorder) self() *enode.Node {
   112  	return nullNode
   113  }
   114  
   115  func (t *pingRecorder) findnode(toid enode.ID, toaddr *net.UDPAddr, target encPubkey) ([]*node, error) {
   116  	return nil, nil
   117  }
   118  
   119  func (t *pingRecorder) ping(toid enode.ID, toaddr *net.UDPAddr) error {
   120  	t.mu.Lock()
   121  	defer t.mu.Unlock()
   122  
   123  	t.pinged[toid] = true
   124  	if t.dead[toid] {
   125  		return errTimeout
   126  	} else {
   127  		return nil
   128  	}
   129  }
   130  
   131  func (t *pingRecorder) close() {}
   132  
   133  func hasDuplicates(slice []*node) bool {
   134  	seen := make(map[enode.ID]bool)
   135  	for i, e := range slice {
   136  		if e == nil {
   137  			panic(fmt.Sprintf("nil *Node at %d", i))
   138  		}
   139  		if seen[e.ID()] {
   140  			return true
   141  		}
   142  		seen[e.ID()] = true
   143  	}
   144  	return false
   145  }
   146  
   147  func sortedByDistanceTo(distbase enode.ID, slice []*node) bool {
   148  	var last enode.ID
   149  	for i, e := range slice {
   150  		if i > 0 && enode.DistCmp(distbase, e.ID(), last) < 0 {
   151  			return false
   152  		}
   153  		last = e.ID()
   154  	}
   155  	return true
   156  }
   157  
   158  func hexEncPubkey(h string) (ret encPubkey) {
   159  	b, err := hex.DecodeString(h)
   160  	if err != nil {
   161  		panic(err)
   162  	}
   163  	if len(b) != len(ret) {
   164  		panic("invalid length")
   165  	}
   166  	copy(ret[:], b)
   167  	return ret
   168  }