func TestPeerSend(t *testing.T) {
	// Start a tester and execute the handshake
	tester, err := startTestPeerInited()
	if err != nil {
		t.Fatalf("failed to start initialized peer: %v", err)
	}
	defer tester.stream.Close()

	// Construct a message and inject into the tester
	message := NewMessage([]byte("peer broadcast test message"))
	envelope, err := message.Wrap(DefaultPoW, Options{
		TTL: DefaultTTL,
	})
	if err != nil {
		t.Fatalf("failed to wrap message: %v", err)
	}
	if err := tester.client.Send(envelope); err != nil {
		t.Fatalf("failed to send message: %v", err)
	}
	// Check that the message is eventually forwarded
	payload := []interface{}{envelope}
	if err := p2p.ExpectMsg(tester.stream, messagesCode, payload); err != nil {
		t.Fatalf("message mismatch: %v", err)
	}
	// Make sure that even with a re-insert, an empty batch is received
	if err := tester.client.Send(envelope); err != nil {
		t.Fatalf("failed to send message: %v", err)
	}
	if err := p2p.ExpectMsg(tester.stream, messagesCode, []interface{}{}); err != nil {
		t.Fatalf("message mismatch: %v", err)
	}
}

func TestPeerMessageExpiration(t *testing.T) {
	// Start a tester and execute the handshake
	tester, err := startTestPeerInited()
	if err != nil {
		t.Fatalf("failed to start initialized peer: %v", err)
	}
	defer tester.stream.Close()

	// Fetch the peer instance for later inspection
	tester.client.peerMu.RLock()
	if peers := len(tester.client.peers); peers != 1 {
		t.Fatalf("peer pool size mismatch: have %v, want %v", peers, 1)
	}
	var peer *peer
	for peer, _ = range tester.client.peers {
		break
	}
	tester.client.peerMu.RUnlock()

	// Construct a message and pass it through the tester
	message := NewMessage([]byte("peer test message"))
	envelope, err := message.Wrap(DefaultPoW, Options{
		TTL: time.Second,
	})
	if err != nil {
		t.Fatalf("failed to wrap message: %v", err)
	}
	if err := tester.client.Send(envelope); err != nil {
		t.Fatalf("failed to send message: %v", err)
	}
	payload := []interface{}{envelope}
	if err := p2p.ExpectMsg(tester.stream, messagesCode, payload); err != nil {
		// A premature empty message may have been broadcast, check the next too
		if err := p2p.ExpectMsg(tester.stream, messagesCode, payload); err != nil {
			t.Fatalf("message mismatch: %v", err)
		}
	}
	// Check that the message is inside the cache
	if !peer.known.Has(envelope.Hash()) {
		t.Fatalf("message not found in cache")
	}
	// Discard messages until expiration and check cache again
	exp := time.Now().Add(time.Second + 2*expirationCycle + 100*time.Millisecond)
	for time.Now().Before(exp) {
		if err := p2p.ExpectMsg(tester.stream, messagesCode, []interface{}{}); err != nil {
			t.Fatalf("message mismatch: %v", err)
		}
	}
	if peer.known.Has(envelope.Hash()) {
		t.Fatalf("message not expired from cache")
	}
}

func TestPeerHandshakeSuccess(t *testing.T) {
	tester := startTestPeer()

	// Wait for and check the handshake
	if err := p2p.ExpectMsg(tester.stream, statusCode, []uint64{protocolVersion}); err != nil {
		t.Fatalf("status message mismatch: %v", err)
	}
	// Send a valid handshake status and make sure connection stays live
	if err := p2p.SendItems(tester.stream, statusCode, protocolVersion); err != nil {
		t.Fatalf("failed to send status: %v", err)
	}
	select {
	case <-tester.termed:
		t.Fatalf("valid handshake disconnected")

	case <-time.After(100 * time.Millisecond):
	}
	// Clean up the test
	tester.stream.Close()

	select {
	case <-tester.termed:
	case <-time.After(time.Second):
		t.Fatalf("local close timed out")
	}
}

func testGetReceipt(t *testing.T, protocol int) {
	// Define three accounts to simulate transactions with
	acc1Key, _ := crypto.HexToECDSA("8a1f9a8f95be41cd7ccb6168179afb4504aefe388d1e14474d32c45c72ce7b7a")
	acc2Key, _ := crypto.HexToECDSA("49a7b37aa6f6645917e7b807e9d1c00d4fa71f18343b0d4122a4d2df64dd6fee")
	acc1Addr := crypto.PubkeyToAddress(acc1Key.PublicKey)
	acc2Addr := crypto.PubkeyToAddress(acc2Key.PublicKey)

	// Create a chain generator with some simple transactions (blatantly stolen from @fjl/chain_makerts_test)
	generator := func(i int, block *core.BlockGen) {
		switch i {
		case 0:
			// In block 1, the test bank sends account #1 some ether.
			tx, _ := types.NewTransaction(block.TxNonce(testBankAddress), acc1Addr, big.NewInt(10000), params.TxGas, nil, nil).SignECDSA(testBankKey)
			block.AddTx(tx)
		case 1:
			// In block 2, the test bank sends some more ether to account #1.
			// acc1Addr passes it on to account #2.
			tx1, _ := types.NewTransaction(block.TxNonce(testBankAddress), acc1Addr, big.NewInt(1000), params.TxGas, nil, nil).SignECDSA(testBankKey)
			tx2, _ := types.NewTransaction(block.TxNonce(acc1Addr), acc2Addr, big.NewInt(1000), params.TxGas, nil, nil).SignECDSA(acc1Key)
			block.AddTx(tx1)
			block.AddTx(tx2)
		case 2:
			// Block 3 is empty but was mined by account #2.
			block.SetCoinbase(acc2Addr)
			block.SetExtra([]byte("yeehaw"))
		case 3:
			// Block 4 includes blocks 2 and 3 as uncle headers (with modified extra data).
			b2 := block.PrevBlock(1).Header()
			b2.Extra = []byte("foo")
			block.AddUncle(b2)
			b3 := block.PrevBlock(2).Header()
			b3.Extra = []byte("foo")
			block.AddUncle(b3)
		}
	}
	// Assemble the test environment
	pm := newTestProtocolManager(4, generator, nil)
	peer, _ := newTestPeer("peer", protocol, pm, true)
	defer peer.close()

	// Collect the hashes to request, and the response to expect
	hashes := []common.Hash{}
	for i := uint64(0); i <= pm.chainman.CurrentBlock().NumberU64(); i++ {
		for _, tx := range pm.chainman.GetBlockByNumber(i).Transactions() {
			hashes = append(hashes, tx.Hash())
		}
	}
	receipts := make([]*types.Receipt, len(hashes))
	for i, hash := range hashes {
		receipts[i] = core.GetReceipt(pm.chaindb, hash)
	}
	// Send the hash request and verify the response
	p2p.Send(peer.app, 0x0f, hashes)
	if err := p2p.ExpectMsg(peer.app, 0x10, receipts); err != nil {
		t.Errorf("receipts mismatch: %v", err)
	}
}

func startTestPeerInited() (*testPeer, error) {
	peer := startTestPeer()

	if err := p2p.ExpectMsg(peer.stream, statusCode, []uint64{protocolVersion}); err != nil {
		peer.stream.Close()
		return nil, err
	}
	if err := p2p.SendItems(peer.stream, statusCode, protocolVersion); err != nil {
		peer.stream.Close()
		return nil, err
	}
	return peer, nil
}

// handshake simulates a trivial handshake that expects the same state from the
// remote side as we are simulating locally.
func (p *testPeer) handshake(t *testing.T, td *big.Int, head common.Hash, genesis common.Hash) {
	msg := &statusData{
		ProtocolVersion: uint32(p.version),
		NetworkId:       uint32(NetworkId),
		TD:              td,
		CurrentBlock:    head,
		GenesisBlock:    genesis,
	}
	if err := p2p.ExpectMsg(p.app, StatusMsg, msg); err != nil {
		t.Fatalf("status recv: %v", err)
	}
	if err := p2p.Send(p.app, StatusMsg, msg); err != nil {
		t.Fatalf("status send: %v", err)
	}
}

func (p *testPeer) handshake(t *testing.T) {
	td, currentBlock, genesis := p.pm.chainman.Status()
	msg := &statusMsgData{
		ProtocolVersion: uint32(p.pm.protVer),
		NetworkId:       uint32(p.pm.netId),
		TD:              td,
		CurrentBlock:    currentBlock,
		GenesisBlock:    genesis,
	}
	if err := p2p.ExpectMsg(p, StatusMsg, msg); err != nil {
		t.Fatalf("status recv: %v", err)
	}
	if err := p2p.Send(p, StatusMsg, msg); err != nil {
		t.Fatalf("status send: %v", err)
	}
}

func TestPeerStatusMessage(t *testing.T) {
	tester := startTestPeer()

	// Wait for the handshake status message and check it
	if err := p2p.ExpectMsg(tester.stream, statusCode, []uint64{protocolVersion}); err != nil {
		t.Fatalf("status message mismatch: %v", err)
	}
	// Terminate the node
	tester.stream.Close()

	select {
	case <-tester.termed:
	case <-time.After(time.Second):
		t.Fatalf("local close timed out")
	}
}

func TestPeerHandshakeFail(t *testing.T) {
	tester := startTestPeer()

	// Wait for and check the handshake
	if err := p2p.ExpectMsg(tester.stream, statusCode, []uint64{protocolVersion}); err != nil {
		t.Fatalf("status message mismatch: %v", err)
	}
	// Send an invalid handshake status and verify disconnect
	if err := p2p.SendItems(tester.stream, messagesCode); err != nil {
		t.Fatalf("failed to send malformed status: %v", err)
	}
	select {
	case <-tester.termed:
	case <-time.After(time.Second):
		t.Fatalf("remote close timed out")
	}
}

func testGetBlockHashes(t *testing.T, protocol int) {
	pm := newTestProtocolManagerMust(t, false, downloader.MaxHashFetch+15, nil, nil)
	peer, _ := newTestPeer("peer", protocol, pm, true)
	defer peer.close()

	// Create a batch of tests for various scenarios
	limit := downloader.MaxHashFetch
	tests := []struct {
		origin common.Hash
		number int
		result int
	}{
		{common.Hash{}, 1, 0},                                   // Make sure non existent hashes don't return results
		{pm.blockchain.Genesis().Hash(), 1, 0},                  // There are no hashes to retrieve up from the genesis
		{pm.blockchain.GetBlockByNumber(5).Hash(), 5, 5},        // All the hashes including the genesis requested
		{pm.blockchain.GetBlockByNumber(5).Hash(), 10, 5},       // More hashes than available till the genesis requested
		{pm.blockchain.GetBlockByNumber(100).Hash(), 10, 10},    // All hashes available from the middle of the chain
		{pm.blockchain.CurrentBlock().Hash(), 10, 10},           // All hashes available from the head of the chain
		{pm.blockchain.CurrentBlock().Hash(), limit, limit},     // Request the maximum allowed hash count
		{pm.blockchain.CurrentBlock().Hash(), limit + 1, limit}, // Request more than the maximum allowed hash count
	}
	// Run each of the tests and verify the results against the chain
	for i, tt := range tests {
		// Assemble the hash response we would like to receive
		resp := make([]common.Hash, tt.result)
		if len(resp) > 0 {
			from := pm.blockchain.GetBlock(tt.origin).NumberU64() - 1
			for j := 0; j < len(resp); j++ {
				resp[j] = pm.blockchain.GetBlockByNumber(uint64(int(from) - j)).Hash()
			}
		}
		// Send the hash request and verify the response
		p2p.Send(peer.app, 0x03, getBlockHashesData{tt.origin, uint64(tt.number)})
		if err := p2p.ExpectMsg(peer.app, 0x04, resp); err != nil {
			t.Errorf("test %d: block hashes mismatch: %v", i, err)
		}
	}
}

func testGetBlockHashesFromNumber(t *testing.T, protocol int) {
	pm := newTestProtocolManagerMust(t, false, downloader.MaxHashFetch+15, nil, nil)
	peer, _ := newTestPeer("peer", protocol, pm, true)
	defer peer.close()

	// Create a batch of tests for various scenarios
	limit := downloader.MaxHashFetch
	tests := []struct {
		origin uint64
		number int
		result int
	}{
		{pm.blockchain.CurrentBlock().NumberU64() + 1, 1, 0},     // Out of bounds requests should return empty
		{pm.blockchain.CurrentBlock().NumberU64(), 1, 1},         // Make sure the head hash can be retrieved
		{pm.blockchain.CurrentBlock().NumberU64() - 4, 5, 5},     // All hashes, including the head hash requested
		{pm.blockchain.CurrentBlock().NumberU64() - 4, 10, 5},    // More hashes requested than available till the head
		{pm.blockchain.CurrentBlock().NumberU64() - 100, 10, 10}, // All hashes available from the middle of the chain
		{0, 10, 10},           // All hashes available from the root of the chain
		{0, limit, limit},     // Request the maximum allowed hash count
		{0, limit + 1, limit}, // Request more than the maximum allowed hash count
		{0, 1, 1},             // Make sure the genesis hash can be retrieved
	}
	// Run each of the tests and verify the results against the chain
	for i, tt := range tests {
		// Assemble the hash response we would like to receive
		resp := make([]common.Hash, tt.result)
		for j := 0; j < len(resp); j++ {
			resp[j] = pm.blockchain.GetBlockByNumber(tt.origin + uint64(j)).Hash()
		}
		// Send the hash request and verify the response
		p2p.Send(peer.app, 0x08, getBlockHashesFromNumberData{tt.origin, uint64(tt.number)})
		if err := p2p.ExpectMsg(peer.app, 0x04, resp); err != nil {
			t.Errorf("test %d: block hashes mismatch: %v", i, err)
		}
	}
}

func testGetBlockBodies(t *testing.T, protocol int) {
	pm := newTestProtocolManagerMust(t, false, downloader.MaxBlockFetch+15, nil, nil)
	peer, _ := newTestPeer("peer", protocol, pm, true)
	defer peer.close()

	// Create a batch of tests for various scenarios
	limit := downloader.MaxBlockFetch
	tests := []struct {
		random    int           // Number of blocks to fetch randomly from the chain
		explicit  []common.Hash // Explicitly requested blocks
		available []bool        // Availability of explicitly requested blocks
		expected  int           // Total number of existing blocks to expect
	}{
		{1, nil, nil, 1},                                                         // A single random block should be retrievable
		{10, nil, nil, 10},                                                       // Multiple random blocks should be retrievable
		{limit, nil, nil, limit},                                                 // The maximum possible blocks should be retrievable
		{limit + 1, nil, nil, limit},                                             // No more than the possible block count should be returned
		{0, []common.Hash{pm.blockchain.Genesis().Hash()}, []bool{true}, 1},      // The genesis block should be retrievable
		{0, []common.Hash{pm.blockchain.CurrentBlock().Hash()}, []bool{true}, 1}, // The chains head block should be retrievable
		{0, []common.Hash{common.Hash{}}, []bool{false}, 0},                      // A non existent block should not be returned

		// Existing and non-existing blocks interleaved should not cause problems
		{0, []common.Hash{
			common.Hash{},
			pm.blockchain.GetBlockByNumber(1).Hash(),
			common.Hash{},
			pm.blockchain.GetBlockByNumber(10).Hash(),
			common.Hash{},
			pm.blockchain.GetBlockByNumber(100).Hash(),
			common.Hash{},
		}, []bool{false, true, false, true, false, true, false}, 3},
	}
	// Run each of the tests and verify the results against the chain
	for i, tt := range tests {
		// Collect the hashes to request, and the response to expect
		hashes, seen := []common.Hash{}, make(map[int64]bool)
		bodies := []*blockBody{}

		for j := 0; j < tt.random; j++ {
			for {
				num := rand.Int63n(int64(pm.blockchain.CurrentBlock().NumberU64()))
				if !seen[num] {
					seen[num] = true

					block := pm.blockchain.GetBlockByNumber(uint64(num))
					hashes = append(hashes, block.Hash())
					if len(bodies) < tt.expected {
						bodies = append(bodies, &blockBody{Transactions: block.Transactions(), Uncles: block.Uncles()})
					}
					break
				}
			}
		}
		for j, hash := range tt.explicit {
			hashes = append(hashes, hash)
			if tt.available[j] && len(bodies) < tt.expected {
				block := pm.blockchain.GetBlock(hash)
				bodies = append(bodies, &blockBody{Transactions: block.Transactions(), Uncles: block.Uncles()})
			}
		}
		// Send the hash request and verify the response
		p2p.Send(peer.app, 0x05, hashes)
		if err := p2p.ExpectMsg(peer.app, 0x06, bodies); err != nil {
			t.Errorf("test %d: bodies mismatch: %v", i, err)
		}
	}
}

//.........这里部分代码省略.........
		}, {
			&getBlockHeadersData{Origin: hashOrNumber{Number: limit / 2}, Amount: 1},
			[]common.Hash{pm.blockchain.GetBlockByNumber(limit / 2).Hash()},
		},
		// Multiple headers should be retrievable in both directions
		{
			&getBlockHeadersData{Origin: hashOrNumber{Number: limit / 2}, Amount: 3},
			[]common.Hash{
				pm.blockchain.GetBlockByNumber(limit / 2).Hash(),
				pm.blockchain.GetBlockByNumber(limit/2 + 1).Hash(),
				pm.blockchain.GetBlockByNumber(limit/2 + 2).Hash(),
			},
		}, {
			&getBlockHeadersData{Origin: hashOrNumber{Number: limit / 2}, Amount: 3, Reverse: true},
			[]common.Hash{
				pm.blockchain.GetBlockByNumber(limit / 2).Hash(),
				pm.blockchain.GetBlockByNumber(limit/2 - 1).Hash(),
				pm.blockchain.GetBlockByNumber(limit/2 - 2).Hash(),
			},
		},
		// Multiple headers with skip lists should be retrievable
		{
			&getBlockHeadersData{Origin: hashOrNumber{Number: limit / 2}, Skip: 3, Amount: 3},
			[]common.Hash{
				pm.blockchain.GetBlockByNumber(limit / 2).Hash(),
				pm.blockchain.GetBlockByNumber(limit/2 + 4).Hash(),
				pm.blockchain.GetBlockByNumber(limit/2 + 8).Hash(),
			},
		}, {
			&getBlockHeadersData{Origin: hashOrNumber{Number: limit / 2}, Skip: 3, Amount: 3, Reverse: true},
			[]common.Hash{
				pm.blockchain.GetBlockByNumber(limit / 2).Hash(),
				pm.blockchain.GetBlockByNumber(limit/2 - 4).Hash(),
				pm.blockchain.GetBlockByNumber(limit/2 - 8).Hash(),
			},
		},
		// The chain endpoints should be retrievable
		{
			&getBlockHeadersData{Origin: hashOrNumber{Number: 0}, Amount: 1},
			[]common.Hash{pm.blockchain.GetBlockByNumber(0).Hash()},
		}, {
			&getBlockHeadersData{Origin: hashOrNumber{Number: pm.blockchain.CurrentBlock().NumberU64()}, Amount: 1},
			[]common.Hash{pm.blockchain.CurrentBlock().Hash()},
		},
		// Ensure protocol limits are honored
		{
			&getBlockHeadersData{Origin: hashOrNumber{Number: pm.blockchain.CurrentBlock().NumberU64() - 1}, Amount: limit + 10, Reverse: true},
			pm.blockchain.GetBlockHashesFromHash(pm.blockchain.CurrentBlock().Hash(), limit),
		},
		// Check that requesting more than available is handled gracefully
		{
			&getBlockHeadersData{Origin: hashOrNumber{Number: pm.blockchain.CurrentBlock().NumberU64() - 4}, Skip: 3, Amount: 3},
			[]common.Hash{
				pm.blockchain.GetBlockByNumber(pm.blockchain.CurrentBlock().NumberU64() - 4).Hash(),
				pm.blockchain.GetBlockByNumber(pm.blockchain.CurrentBlock().NumberU64()).Hash(),
			},
		}, {
			&getBlockHeadersData{Origin: hashOrNumber{Number: 4}, Skip: 3, Amount: 3, Reverse: true},
			[]common.Hash{
				pm.blockchain.GetBlockByNumber(4).Hash(),
				pm.blockchain.GetBlockByNumber(0).Hash(),
			},
		},
		// Check that requesting more than available is handled gracefully, even if mid skip
		{
			&getBlockHeadersData{Origin: hashOrNumber{Number: pm.blockchain.CurrentBlock().NumberU64() - 4}, Skip: 2, Amount: 3},
			[]common.Hash{
				pm.blockchain.GetBlockByNumber(pm.blockchain.CurrentBlock().NumberU64() - 4).Hash(),
				pm.blockchain.GetBlockByNumber(pm.blockchain.CurrentBlock().NumberU64() - 1).Hash(),
			},
		}, {
			&getBlockHeadersData{Origin: hashOrNumber{Number: 4}, Skip: 2, Amount: 3, Reverse: true},
			[]common.Hash{
				pm.blockchain.GetBlockByNumber(4).Hash(),
				pm.blockchain.GetBlockByNumber(1).Hash(),
			},
		},
		// Check that non existing headers aren't returned
		{
			&getBlockHeadersData{Origin: hashOrNumber{Hash: unknown}, Amount: 1},
			[]common.Hash{},
		}, {
			&getBlockHeadersData{Origin: hashOrNumber{Number: pm.blockchain.CurrentBlock().NumberU64() + 1}, Amount: 1},
			[]common.Hash{},
		},
	}
	// Run each of the tests and verify the results against the chain
	for i, tt := range tests {
		// Collect the headers to expect in the response
		headers := []*types.Header{}
		for _, hash := range tt.expect {
			headers = append(headers, pm.blockchain.GetBlock(hash).Header())
		}
		// Send the hash request and verify the response
		p2p.Send(peer.app, 0x03, tt.query)
		if err := p2p.ExpectMsg(peer.app, 0x04, headers); err != nil {
			t.Errorf("test %d: headers mismatch: %v", i, err)
		}
	}
}

func testDAOChallenge(t *testing.T, localForked, remoteForked bool, timeout bool) {
	// Reduce the DAO handshake challenge timeout
	if timeout {
		defer func(old time.Duration) { daoChallengeTimeout = old }(daoChallengeTimeout)
		daoChallengeTimeout = 500 * time.Millisecond
	}
	// Create a DAO aware protocol manager
	var (
		evmux         = new(event.TypeMux)
		pow           = new(core.FakePow)
		db, _         = ethdb.NewMemDatabase()
		genesis       = core.WriteGenesisBlockForTesting(db)
		config        = &core.ChainConfig{DAOForkBlock: big.NewInt(1), DAOForkSupport: localForked}
		blockchain, _ = core.NewBlockChain(db, config, pow, evmux)
	)
	pm, err := NewProtocolManager(config, false, NetworkId, evmux, new(testTxPool), pow, blockchain, db)
	if err != nil {
		t.Fatalf("failed to start test protocol manager: %v", err)
	}
	pm.Start()
	defer pm.Stop()

	// Connect a new peer and check that we receive the DAO challenge
	peer, _ := newTestPeer("peer", eth63, pm, true)
	defer peer.close()

	challenge := &getBlockHeadersData{
		Origin:  hashOrNumber{Number: config.DAOForkBlock.Uint64()},
		Amount:  1,
		Skip:    0,
		Reverse: false,
	}
	if err := p2p.ExpectMsg(peer.app, GetBlockHeadersMsg, challenge); err != nil {
		t.Fatalf("challenge mismatch: %v", err)
	}
	// Create a block to reply to the challenge if no timeout is simualted
	if !timeout {
		blocks, _ := core.GenerateChain(nil, genesis, db, 1, func(i int, block *core.BlockGen) {
			if remoteForked {
				block.SetExtra(params.DAOForkBlockExtra)
			}
		})
		if err := p2p.Send(peer.app, BlockHeadersMsg, []*types.Header{blocks[0].Header()}); err != nil {
			t.Fatalf("failed to answer challenge: %v", err)
		}
		time.Sleep(100 * time.Millisecond) // Sleep to avoid the verification racing with the drops
	} else {
		// Otherwise wait until the test timeout passes
		time.Sleep(daoChallengeTimeout + 500*time.Millisecond)
	}
	// Verify that depending on fork side, the remote peer is maintained or dropped
	if localForked == remoteForked && !timeout {
		if peers := pm.peers.Len(); peers != 1 {
			t.Fatalf("peer count mismatch: have %d, want %d", peers, 1)
		}
	} else {
		if peers := pm.peers.Len(); peers != 0 {
			t.Fatalf("peer count mismatch: have %d, want %d", peers, 0)
		}
	}
}