github.com/neatlab/neatio@v1.7.3-0.20220425043230-d903e92fcc75/network/p2p/discover/udp_test.go (about)

     1  package discover
     2  
     3  import (
     4  	"bytes"
     5  	"crypto/ecdsa"
     6  	"encoding/binary"
     7  	"encoding/hex"
     8  	"errors"
     9  	"fmt"
    10  	"io"
    11  	"math/rand"
    12  	"net"
    13  	"path/filepath"
    14  	"reflect"
    15  	"runtime"
    16  	"sync"
    17  	"testing"
    18  	"time"
    19  
    20  	"github.com/davecgh/go-spew/spew"
    21  	"github.com/neatlab/neatio/utilities/common"
    22  	"github.com/neatlab/neatio/utilities/crypto"
    23  	"github.com/neatlab/neatio/utilities/rlp"
    24  )
    25  
    26  func init() {
    27  	spew.Config.DisableMethods = true
    28  }
    29  
    30  var (
    31  	futureExp          = uint64(time.Now().Add(10 * time.Hour).Unix())
    32  	testTarget         = NodeID{0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1}
    33  	testRemote         = rpcEndpoint{IP: net.ParseIP("1.1.1.1").To4(), UDP: 1, TCP: 2}
    34  	testLocalAnnounced = rpcEndpoint{IP: net.ParseIP("2.2.2.2").To4(), UDP: 3, TCP: 4}
    35  	testLocal          = rpcEndpoint{IP: net.ParseIP("3.3.3.3").To4(), UDP: 5, TCP: 6}
    36  )
    37  
    38  type udpTest struct {
    39  	t                   *testing.T
    40  	pipe                *dgramPipe
    41  	table               *Table
    42  	udp                 *udp
    43  	sent                [][]byte
    44  	localkey, remotekey *ecdsa.PrivateKey
    45  	remoteaddr          *net.UDPAddr
    46  }
    47  
    48  func newUDPTest(t *testing.T) *udpTest {
    49  	test := &udpTest{
    50  		t:          t,
    51  		pipe:       newpipe(),
    52  		localkey:   newkey(),
    53  		remotekey:  newkey(),
    54  		remoteaddr: &net.UDPAddr{IP: net.IP{10, 0, 1, 99}, Port: 30303},
    55  	}
    56  	test.table, test.udp, _ = newUDP(test.pipe, Config{PrivateKey: test.localkey})
    57  	<-test.table.initDone
    58  	return test
    59  }
    60  
    61  func (test *udpTest) packetIn(wantError error, ptype byte, data packet) error {
    62  	enc, _, err := encodePacket(test.remotekey, ptype, data)
    63  	if err != nil {
    64  		return test.errorf("packet (%d) encode error: %v", ptype, err)
    65  	}
    66  	test.sent = append(test.sent, enc)
    67  	if err = test.udp.handlePacket(test.remoteaddr, enc); err != wantError {
    68  		return test.errorf("error mismatch: got %q, want %q", err, wantError)
    69  	}
    70  	return nil
    71  }
    72  
    73  func (test *udpTest) waitPacketOut(validate interface{}) ([]byte, error) {
    74  	dgram := test.pipe.waitPacketOut()
    75  	p, _, hash, err := decodePacket(dgram)
    76  	if err != nil {
    77  		return hash, test.errorf("sent packet decode error: %v", err)
    78  	}
    79  	fn := reflect.ValueOf(validate)
    80  	exptype := fn.Type().In(0)
    81  	if reflect.TypeOf(p) != exptype {
    82  		return hash, test.errorf("sent packet type mismatch, got: %v, want: %v", reflect.TypeOf(p), exptype)
    83  	}
    84  	fn.Call([]reflect.Value{reflect.ValueOf(p)})
    85  	return hash, nil
    86  }
    87  
    88  func (test *udpTest) errorf(format string, args ...interface{}) error {
    89  	_, file, line, ok := runtime.Caller(2)
    90  	if ok {
    91  		file = filepath.Base(file)
    92  	} else {
    93  		file = "???"
    94  		line = 1
    95  	}
    96  	err := fmt.Errorf(format, args...)
    97  	fmt.Printf("\t%s:%d: %v\n", file, line, err)
    98  	test.t.Fail()
    99  	return err
   100  }
   101  
   102  func TestUDP_packetErrors(t *testing.T) {
   103  	test := newUDPTest(t)
   104  	defer test.table.Close()
   105  
   106  	test.packetIn(errExpired, pingPacket, &ping{From: testRemote, To: testLocalAnnounced, Version: Version})
   107  	test.packetIn(errUnsolicitedReply, pongPacket, &pong{ReplyTok: []byte{}, Expiration: futureExp})
   108  	test.packetIn(errUnknownNode, findnodePacket, &findnode{Expiration: futureExp})
   109  	test.packetIn(errUnsolicitedReply, neighborsPacket, &neighbors{Expiration: futureExp})
   110  }
   111  
   112  func TestUDP_pingTimeout(t *testing.T) {
   113  	t.Parallel()
   114  	test := newUDPTest(t)
   115  	defer test.table.Close()
   116  
   117  	toaddr := &net.UDPAddr{IP: net.ParseIP("1.2.3.4"), Port: 2222}
   118  	toid := NodeID{1, 2, 3, 4}
   119  	if err := test.udp.ping(toid, toaddr); err != errTimeout {
   120  		t.Error("expected timeout error, got", err)
   121  	}
   122  }
   123  
   124  func TestUDP_responseTimeouts(t *testing.T) {
   125  	t.Parallel()
   126  	test := newUDPTest(t)
   127  	defer test.table.Close()
   128  
   129  	rand.Seed(time.Now().UnixNano())
   130  	randomDuration := func(max time.Duration) time.Duration {
   131  		return time.Duration(rand.Int63n(int64(max)))
   132  	}
   133  
   134  	var (
   135  		nReqs      = 200
   136  		nTimeouts  = 0
   137  		nilErr     = make(chan error, nReqs)
   138  		timeoutErr = make(chan error, nReqs)
   139  	)
   140  	for i := 0; i < nReqs; i++ {
   141  		p := &pending{
   142  			ptype:    byte(rand.Intn(255)),
   143  			callback: func(interface{}) bool { return true },
   144  		}
   145  		binary.BigEndian.PutUint64(p.from[:], uint64(i))
   146  		if p.ptype <= 128 {
   147  			p.errc = timeoutErr
   148  			test.udp.addpending <- p
   149  			nTimeouts++
   150  		} else {
   151  			p.errc = nilErr
   152  			test.udp.addpending <- p
   153  			time.AfterFunc(randomDuration(60*time.Millisecond), func() {
   154  				if !test.udp.handleReply(p.from, p.ptype, nil) {
   155  					t.Logf("not matched: %v", p)
   156  				}
   157  			})
   158  		}
   159  		time.Sleep(randomDuration(30 * time.Millisecond))
   160  	}
   161  
   162  	var (
   163  		recvDeadline        = time.After(20 * time.Second)
   164  		nTimeoutsRecv, nNil = 0, 0
   165  	)
   166  	for i := 0; i < nReqs; i++ {
   167  		select {
   168  		case err := <-timeoutErr:
   169  			if err != errTimeout {
   170  				t.Fatalf("got non-timeout error on timeoutErr %d: %v", i, err)
   171  			}
   172  			nTimeoutsRecv++
   173  		case err := <-nilErr:
   174  			if err != nil {
   175  				t.Fatalf("got non-nil error on nilErr %d: %v", i, err)
   176  			}
   177  			nNil++
   178  		case <-recvDeadline:
   179  			t.Fatalf("exceeded recv deadline")
   180  		}
   181  	}
   182  	if nTimeoutsRecv != nTimeouts {
   183  		t.Errorf("wrong number of timeout errors received: got %d, want %d", nTimeoutsRecv, nTimeouts)
   184  	}
   185  	if nNil != nReqs-nTimeouts {
   186  		t.Errorf("wrong number of successful replies: got %d, want %d", nNil, nReqs-nTimeouts)
   187  	}
   188  }
   189  
   190  func TestUDP_findnodeTimeout(t *testing.T) {
   191  	t.Parallel()
   192  	test := newUDPTest(t)
   193  	defer test.table.Close()
   194  
   195  	toaddr := &net.UDPAddr{IP: net.ParseIP("1.2.3.4"), Port: 2222}
   196  	toid := NodeID{1, 2, 3, 4}
   197  	target := NodeID{4, 5, 6, 7}
   198  	result, err := test.udp.findnode(toid, toaddr, target)
   199  	if err != errTimeout {
   200  		t.Error("expected timeout error, got", err)
   201  	}
   202  	if len(result) > 0 {
   203  		t.Error("expected empty result, got", result)
   204  	}
   205  }
   206  
   207  func TestUDP_findnode(t *testing.T) {
   208  	test := newUDPTest(t)
   209  	defer test.table.Close()
   210  
   211  	targetHash := crypto.Keccak256Hash(testTarget[:])
   212  	nodes := &nodesByDistance{target: targetHash}
   213  	for i := 0; i < bucketSize; i++ {
   214  		nodes.push(nodeAtDistance(test.table.self.sha, i+2), bucketSize)
   215  	}
   216  	test.table.stuff(nodes.entries)
   217  
   218  	test.table.db.updateBondTime(PubkeyID(&test.remotekey.PublicKey), time.Now())
   219  
   220  	test.packetIn(nil, findnodePacket, &findnode{Target: testTarget, Expiration: futureExp})
   221  	expected := test.table.closest(targetHash, bucketSize)
   222  
   223  	waitNeighbors := func(want []*Node) {
   224  		test.waitPacketOut(func(p *neighbors) {
   225  			if len(p.Nodes) != len(want) {
   226  				t.Errorf("wrong number of results: got %d, want %d", len(p.Nodes), bucketSize)
   227  			}
   228  			for i := range p.Nodes {
   229  				if p.Nodes[i].ID != want[i].ID {
   230  					t.Errorf("result mismatch at %d:\n  got:  %v\n  want: %v", i, p.Nodes[i], expected.entries[i])
   231  				}
   232  			}
   233  		})
   234  	}
   235  	waitNeighbors(expected.entries[:maxNeighbors])
   236  	waitNeighbors(expected.entries[maxNeighbors:])
   237  }
   238  
   239  func TestUDP_findnodeMultiReply(t *testing.T) {
   240  	test := newUDPTest(t)
   241  	defer test.table.Close()
   242  
   243  	resultc, errc := make(chan []*Node), make(chan error)
   244  	go func() {
   245  		rid := PubkeyID(&test.remotekey.PublicKey)
   246  		ns, err := test.udp.findnode(rid, test.remoteaddr, testTarget)
   247  		if err != nil && len(ns) == 0 {
   248  			errc <- err
   249  		} else {
   250  			resultc <- ns
   251  		}
   252  	}()
   253  
   254  	test.waitPacketOut(func(p *findnode) {
   255  		if p.Target != testTarget {
   256  			t.Errorf("wrong target: got %v, want %v", p.Target, testTarget)
   257  		}
   258  	})
   259  
   260  	list := []*Node{
   261  		MustParseNode("enode://ba85011c70bcc5c04d8607d3a0ed29aa6179c092cbdda10d5d32684fb33ed01bd94f588ca8f91ac48318087dcb02eaf36773a7a453f0eedd6742af668097b29c@10.0.1.16:30303?discport=30304"),
   262  		MustParseNode("enode://81fa361d25f157cd421c60dcc28d8dac5ef6a89476633339c5df30287474520caca09627da18543d9079b5b288698b542d56167aa5c09111e55acdbbdf2ef799@10.0.1.16:30303"),
   263  		MustParseNode("enode://9bffefd833d53fac8e652415f4973bee289e8b1a5c6c4cbe70abf817ce8a64cee11b823b66a987f51aaa9fba0d6a91b3e6bf0d5a5d1042de8e9eeea057b217f8@10.0.1.36:30301?discport=17"),
   264  		MustParseNode("enode://1b5b4aa662d7cb44a7221bfba67302590b643028197a7d5214790f3bac7aaa4a3241be9e83c09cf1f6c69d007c634faae3dc1b1221793e8446c0b3a09de65960@10.0.1.16:30303"),
   265  	}
   266  	rpclist := make([]rpcNode, len(list))
   267  	for i := range list {
   268  		rpclist[i] = nodeToRPC(list[i])
   269  	}
   270  	test.packetIn(nil, neighborsPacket, &neighbors{Expiration: futureExp, Nodes: rpclist[:2]})
   271  	test.packetIn(nil, neighborsPacket, &neighbors{Expiration: futureExp, Nodes: rpclist[2:]})
   272  
   273  	select {
   274  	case result := <-resultc:
   275  		want := append(list[:2], list[3:]...)
   276  		if !reflect.DeepEqual(result, want) {
   277  			t.Errorf("neighbors mismatch:\n  got:  %v\n  want: %v", result, want)
   278  		}
   279  	case err := <-errc:
   280  		t.Errorf("findnode error: %v", err)
   281  	case <-time.After(5 * time.Second):
   282  		t.Error("findnode did not return within 5 seconds")
   283  	}
   284  }
   285  
   286  func TestUDP_successfulPing(t *testing.T) {
   287  	test := newUDPTest(t)
   288  	added := make(chan *Node, 1)
   289  	test.table.nodeAddedHook = func(n *Node) { added <- n }
   290  	defer test.table.Close()
   291  
   292  	go test.packetIn(nil, pingPacket, &ping{From: testRemote, To: testLocalAnnounced, Version: Version, Expiration: futureExp})
   293  
   294  	test.waitPacketOut(func(p *pong) {
   295  		pinghash := test.sent[0][:macSize]
   296  		if !bytes.Equal(p.ReplyTok, pinghash) {
   297  			t.Errorf("got pong.ReplyTok %x, want %x", p.ReplyTok, pinghash)
   298  		}
   299  		wantTo := rpcEndpoint{
   300  			IP: test.remoteaddr.IP, UDP: uint16(test.remoteaddr.Port),
   301  			TCP: testRemote.TCP,
   302  		}
   303  		if !reflect.DeepEqual(p.To, wantTo) {
   304  			t.Errorf("got pong.To %v, want %v", p.To, wantTo)
   305  		}
   306  	})
   307  
   308  	hash, _ := test.waitPacketOut(func(p *ping) error {
   309  		if !reflect.DeepEqual(p.From, test.udp.ourEndpoint) {
   310  			t.Errorf("got ping.From %v, want %v", p.From, test.udp.ourEndpoint)
   311  		}
   312  		wantTo := rpcEndpoint{
   313  			IP: test.remoteaddr.IP, UDP: uint16(test.remoteaddr.Port),
   314  			TCP: 0,
   315  		}
   316  		if !reflect.DeepEqual(p.To, wantTo) {
   317  			t.Errorf("got ping.To %v, want %v", p.To, wantTo)
   318  		}
   319  		return nil
   320  	})
   321  	test.packetIn(nil, pongPacket, &pong{ReplyTok: hash, Expiration: futureExp})
   322  
   323  	select {
   324  	case n := <-added:
   325  		rid := PubkeyID(&test.remotekey.PublicKey)
   326  		if n.ID != rid {
   327  			t.Errorf("node has wrong ID: got %v, want %v", n.ID, rid)
   328  		}
   329  		if !n.IP.Equal(test.remoteaddr.IP) {
   330  			t.Errorf("node has wrong IP: got %v, want: %v", n.IP, test.remoteaddr.IP)
   331  		}
   332  		if int(n.UDP) != test.remoteaddr.Port {
   333  			t.Errorf("node has wrong UDP port: got %v, want: %v", n.UDP, test.remoteaddr.Port)
   334  		}
   335  		if n.TCP != testRemote.TCP {
   336  			t.Errorf("node has wrong TCP port: got %v, want: %v", n.TCP, testRemote.TCP)
   337  		}
   338  	case <-time.After(2 * time.Second):
   339  		t.Errorf("node was not added within 2 seconds")
   340  	}
   341  }
   342  
   343  var testPackets = []struct {
   344  	input      string
   345  	wantPacket interface{}
   346  }{
   347  	{
   348  		input: "71dbda3a79554728d4f94411e42ee1f8b0d561c10e1e5f5893367948c6a7d70bb87b235fa28a77070271b6c164a2dce8c7e13a5739b53b5e96f2e5acb0e458a02902f5965d55ecbeb2ebb6cabb8b2b232896a36b737666c55265ad0a68412f250001ea04cb847f000001820cfa8215a8d790000000000000000000000000000000018208ae820d058443b9a355",
   349  		wantPacket: &ping{
   350  			Version:    4,
   351  			From:       rpcEndpoint{net.ParseIP("127.0.0.1").To4(), 3322, 5544},
   352  			To:         rpcEndpoint{net.ParseIP("::1"), 2222, 3333},
   353  			Expiration: 1136239445,
   354  			Rest:       []rlp.RawValue{},
   355  		},
   356  	},
   357  	{
   358  		input: "e9614ccfd9fc3e74360018522d30e1419a143407ffcce748de3e22116b7e8dc92ff74788c0b6663aaa3d67d641936511c8f8d6ad8698b820a7cf9e1be7155e9a241f556658c55428ec0563514365799a4be2be5a685a80971ddcfa80cb422cdd0101ec04cb847f000001820cfa8215a8d790000000000000000000000000000000018208ae820d058443b9a3550102",
   359  		wantPacket: &ping{
   360  			Version:    4,
   361  			From:       rpcEndpoint{net.ParseIP("127.0.0.1").To4(), 3322, 5544},
   362  			To:         rpcEndpoint{net.ParseIP("::1"), 2222, 3333},
   363  			Expiration: 1136239445,
   364  			Rest:       []rlp.RawValue{{0x01}, {0x02}},
   365  		},
   366  	},
   367  	{
   368  		input: "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",
   369  		wantPacket: &ping{
   370  			Version:    555,
   371  			From:       rpcEndpoint{net.ParseIP("2001:db8:3c4d:15::abcd:ef12"), 3322, 5544},
   372  			To:         rpcEndpoint{net.ParseIP("2001:db8:85a3:8d3:1319:8a2e:370:7348"), 2222, 33338},
   373  			Expiration: 1136239445,
   374  			Rest:       []rlp.RawValue{{0xC5, 0x01, 0x02, 0x03, 0x04, 0x05}},
   375  		},
   376  	},
   377  	{
   378  		input: "09b2428d83348d27cdf7064ad9024f526cebc19e4958f0fdad87c15eb598dd61d08423e0bf66b2069869e1724125f820d851c136684082774f870e614d95a2855d000f05d1648b2d5945470bc187c2d2216fbe870f43ed0909009882e176a46b0102f846d79020010db885a308d313198a2e037073488208ae82823aa0fbc914b16819237dcd8801d7e53f69e9719adecb3cc0e790c57e91ca4461c9548443b9a355c6010203c2040506a0c969a58f6f9095004c0177a6b47f451530cab38966a25cca5cb58f055542124e",
   379  		wantPacket: &pong{
   380  			To:         rpcEndpoint{net.ParseIP("2001:db8:85a3:8d3:1319:8a2e:370:7348"), 2222, 33338},
   381  			ReplyTok:   common.Hex2Bytes("fbc914b16819237dcd8801d7e53f69e9719adecb3cc0e790c57e91ca4461c954"),
   382  			Expiration: 1136239445,
   383  			Rest:       []rlp.RawValue{{0xC6, 0x01, 0x02, 0x03, 0xC2, 0x04, 0x05}, {0x06}},
   384  		},
   385  	},
   386  	{
   387  		input: "c7c44041b9f7c7e41934417ebac9a8e1a4c6298f74553f2fcfdcae6ed6fe53163eb3d2b52e39fe91831b8a927bf4fc222c3902202027e5e9eb812195f95d20061ef5cd31d502e47ecb61183f74a504fe04c51e73df81f25c4d506b26db4517490103f84eb840ca634cae0d49acb401d8a4c6b6fe8c55b70d115bf400769cc1400f3258cd31387574077f301b421bc84df7266c44e9e6d569fc56be00812904767bf5ccd1fc7f8443b9a35582999983999999280dc62cc8255c73471e0a61da0c89acdc0e035e260add7fc0c04ad9ebf3919644c91cb247affc82b69bd2ca235c71eab8e49737c937a2c396",
   388  		wantPacket: &findnode{
   389  			Target:     MustHexID("ca634cae0d49acb401d8a4c6b6fe8c55b70d115bf400769cc1400f3258cd31387574077f301b421bc84df7266c44e9e6d569fc56be00812904767bf5ccd1fc7f"),
   390  			Expiration: 1136239445,
   391  			Rest:       []rlp.RawValue{{0x82, 0x99, 0x99}, {0x83, 0x99, 0x99, 0x99}},
   392  		},
   393  	},
   394  	{
   395  		input: "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",
   396  		wantPacket: &neighbors{
   397  			Nodes: []rpcNode{
   398  				{
   399  					ID:  MustHexID("3155e1427f85f10a5c9a7755877748041af1bcd8d474ec065eb33df57a97babf54bfd2103575fa829115d224c523596b401065a97f74010610fce76382c0bf32"),
   400  					IP:  net.ParseIP("99.33.22.55").To4(),
   401  					UDP: 4444,
   402  					TCP: 4445,
   403  				},
   404  				{
   405  					ID:  MustHexID("312c55512422cf9b8a4097e9a6ad79402e87a15ae909a4bfefa22398f03d20951933beea1e4dfa6f968212385e829f04c2d314fc2d4e255e0d3bc08792b069db"),
   406  					IP:  net.ParseIP("1.2.3.4").To4(),
   407  					UDP: 1,
   408  					TCP: 1,
   409  				},
   410  				{
   411  					ID:  MustHexID("38643200b172dcfef857492156971f0e6aa2c538d8b74010f8e140811d53b98c765dd2d96126051913f44582e8c199ad7c6d6819e9a56483f637feaac9448aac"),
   412  					IP:  net.ParseIP("2001:db8:3c4d:15::abcd:ef12"),
   413  					UDP: 3333,
   414  					TCP: 3333,
   415  				},
   416  				{
   417  					ID:  MustHexID("8dcab8618c3253b558d459da53bd8fa68935a719aff8b811197101a4b2b47dd2d47295286fc00cc081bb542d760717d1bdd6bec2c37cd72eca367d6dd3b9df73"),
   418  					IP:  net.ParseIP("2001:db8:85a3:8d3:1319:8a2e:370:7348"),
   419  					UDP: 999,
   420  					TCP: 1000,
   421  				},
   422  			},
   423  			Expiration: 1136239445,
   424  			Rest:       []rlp.RawValue{{0x01}, {0x02}, {0x03}},
   425  		},
   426  	},
   427  }
   428  
   429  func TestForwardCompatibility(t *testing.T) {
   430  	testkey, _ := crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
   431  	wantNodeID := PubkeyID(&testkey.PublicKey)
   432  
   433  	for _, test := range testPackets {
   434  		input, err := hex.DecodeString(test.input)
   435  		if err != nil {
   436  			t.Fatalf("invalid hex: %s", test.input)
   437  		}
   438  		packet, nodeid, _, err := decodePacket(input)
   439  		if err != nil {
   440  			t.Errorf("did not accept packet %s\n%v", test.input, err)
   441  			continue
   442  		}
   443  		if !reflect.DeepEqual(packet, test.wantPacket) {
   444  			t.Errorf("got %s\nwant %s", spew.Sdump(packet), spew.Sdump(test.wantPacket))
   445  		}
   446  		if nodeid != wantNodeID {
   447  			t.Errorf("got id %v\nwant id %v", nodeid, wantNodeID)
   448  		}
   449  	}
   450  }
   451  
   452  type dgramPipe struct {
   453  	mu      *sync.Mutex
   454  	cond    *sync.Cond
   455  	closing chan struct{}
   456  	closed  bool
   457  	queue   [][]byte
   458  }
   459  
   460  func newpipe() *dgramPipe {
   461  	mu := new(sync.Mutex)
   462  	return &dgramPipe{
   463  		closing: make(chan struct{}),
   464  		cond:    &sync.Cond{L: mu},
   465  		mu:      mu,
   466  	}
   467  }
   468  
   469  func (c *dgramPipe) WriteToUDP(b []byte, to *net.UDPAddr) (n int, err error) {
   470  	msg := make([]byte, len(b))
   471  	copy(msg, b)
   472  	c.mu.Lock()
   473  	defer c.mu.Unlock()
   474  	if c.closed {
   475  		return 0, errors.New("closed")
   476  	}
   477  	c.queue = append(c.queue, msg)
   478  	c.cond.Signal()
   479  	return len(b), nil
   480  }
   481  
   482  func (c *dgramPipe) ReadFromUDP(b []byte) (n int, addr *net.UDPAddr, err error) {
   483  	<-c.closing
   484  	return 0, nil, io.EOF
   485  }
   486  
   487  func (c *dgramPipe) Close() error {
   488  	c.mu.Lock()
   489  	defer c.mu.Unlock()
   490  	if !c.closed {
   491  		close(c.closing)
   492  		c.closed = true
   493  	}
   494  	return nil
   495  }
   496  
   497  func (c *dgramPipe) LocalAddr() net.Addr {
   498  	return &net.UDPAddr{IP: testLocal.IP, Port: int(testLocal.UDP)}
   499  }
   500  
   501  func (c *dgramPipe) waitPacketOut() []byte {
   502  	c.mu.Lock()
   503  	defer c.mu.Unlock()
   504  	for len(c.queue) == 0 {
   505  		c.cond.Wait()
   506  	}
   507  	p := c.queue[0]
   508  	copy(c.queue, c.queue[1:])
   509  	c.queue = c.queue[:len(c.queue)-1]
   510  	return p
   511  }