p2p/protocols, p2p/testing: protocol abstraction and testing

3 files changed, 473 insertions, 0 deletions

diff --git a/p2p/testing/peerpool.go b/p2p/testing/peerpool.go
new file mode 100644
index 000000000..45c6e6142
--- /dev/null
+++ b/p2p/testing/peerpool.go
@@ -0,0 +1,67 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package testing
+
+import (
+	"fmt"
+	"sync"
+
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/p2p/discover"
+)
+
+type TestPeer interface {
+	ID() discover.NodeID
+	Drop(error)
+}
+
+// TestPeerPool is an example peerPool to demonstrate registration of peer connections
+type TestPeerPool struct {
+	lock  sync.Mutex
+	peers map[discover.NodeID]TestPeer
+}
+
+func NewTestPeerPool() *TestPeerPool {
+	return &TestPeerPool{peers: make(map[discover.NodeID]TestPeer)}
+}
+
+func (self *TestPeerPool) Add(p TestPeer) {
+	self.lock.Lock()
+	defer self.lock.Unlock()
+	log.Trace(fmt.Sprintf("pp add peer  %v", p.ID()))
+	self.peers[p.ID()] = p
+
+}
+
+func (self *TestPeerPool) Remove(p TestPeer) {
+	self.lock.Lock()
+	defer self.lock.Unlock()
+	delete(self.peers, p.ID())
+}
+
+func (self *TestPeerPool) Has(id discover.NodeID) bool {
+	self.lock.Lock()
+	defer self.lock.Unlock()
+	_, ok := self.peers[id]
+	return ok
+}
+
+func (self *TestPeerPool) Get(id discover.NodeID) TestPeer {
+	self.lock.Lock()
+	defer self.lock.Unlock()
+	return self.peers[id]
+}
diff --git a/p2p/testing/protocolsession.go b/p2p/testing/protocolsession.go
new file mode 100644
index 000000000..a779aeebb
--- /dev/null
+++ b/p2p/testing/protocolsession.go
@@ -0,0 +1,206 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package testing
+
+import (
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/p2p/discover"
+	"github.com/ethereum/go-ethereum/p2p/simulations/adapters"
+)
+
+// ProtocolSession is a quasi simulation of a pivot node running
+// a service and a number of dummy peers that can send (trigger) or
+// receive (expect) messages
+type ProtocolSession struct {
+	Server  *p2p.Server
+	IDs     []discover.NodeID
+	adapter *adapters.SimAdapter
+	events  chan *p2p.PeerEvent
+}
+
+// Exchange is the basic units of protocol tests
+// the triggers and expects in the arrays are run immediately and asynchronously
+// thus one cannot have multiple expects for the SAME peer with DIFFERENT message types
+// because it's unpredictable which expect will receive which message
+// (with expect #1 and #2, messages might be sent #2 and #1, and both expects will complain about wrong message code)
+// an exchange is defined on a session
+type Exchange struct {
+	Label    string
+	Triggers []Trigger
+	Expects  []Expect
+}
+
+// Trigger is part of the exchange, incoming message for the pivot node
+// sent by a peer
+type Trigger struct {
+	Msg     interface{}     // type of message to be sent
+	Code    uint64          // code of message is given
+	Peer    discover.NodeID // the peer to send the message to
+	Timeout time.Duration   // timeout duration for the sending
+}
+
+// Expect is part of an exchange, outgoing message from the pivot node
+// received by a peer
+type Expect struct {
+	Msg     interface{}     // type of message to expect
+	Code    uint64          // code of message is now given
+	Peer    discover.NodeID // the peer that expects the message
+	Timeout time.Duration   // timeout duration for receiving
+}
+
+// Disconnect represents a disconnect event, used and checked by TestDisconnected
+type Disconnect struct {
+	Peer  discover.NodeID // discconnected peer
+	Error error           // disconnect reason
+}
+
+// trigger sends messages from peers
+func (self *ProtocolSession) trigger(trig Trigger) error {
+	simNode, ok := self.adapter.GetNode(trig.Peer)
+	if !ok {
+		return fmt.Errorf("trigger: peer %v does not exist (1- %v)", trig.Peer, len(self.IDs))
+	}
+	mockNode, ok := simNode.Services()[0].(*mockNode)
+	if !ok {
+		return fmt.Errorf("trigger: peer %v is not a mock", trig.Peer)
+	}
+
+	errc := make(chan error)
+
+	go func() {
+		errc <- mockNode.Trigger(&trig)
+	}()
+
+	t := trig.Timeout
+	if t == time.Duration(0) {
+		t = 1000 * time.Millisecond
+	}
+	select {
+	case err := <-errc:
+		return err
+	case <-time.After(t):
+		return fmt.Errorf("timout expecting %v to send to peer %v", trig.Msg, trig.Peer)
+	}
+}
+
+// expect checks an expectation of a message sent out by the pivot node
+func (self *ProtocolSession) expect(exp Expect) error {
+	if exp.Msg == nil {
+		return errors.New("no message to expect")
+	}
+	simNode, ok := self.adapter.GetNode(exp.Peer)
+	if !ok {
+		return fmt.Errorf("trigger: peer %v does not exist (1- %v)", exp.Peer, len(self.IDs))
+	}
+	mockNode, ok := simNode.Services()[0].(*mockNode)
+	if !ok {
+		return fmt.Errorf("trigger: peer %v is not a mock", exp.Peer)
+	}
+
+	errc := make(chan error)
+	go func() {
+		errc <- mockNode.Expect(&exp)
+	}()
+
+	t := exp.Timeout
+	if t == time.Duration(0) {
+		t = 2000 * time.Millisecond
+	}
+	select {
+	case err := <-errc:
+		return err
+	case <-time.After(t):
+		return fmt.Errorf("timout expecting %v sent to peer %v", exp.Msg, exp.Peer)
+	}
+}
+
+// TestExchanges tests a series of exchanges against the session
+func (self *ProtocolSession) TestExchanges(exchanges ...Exchange) error {
+	// launch all triggers of this exchanges
+
+	for _, e := range exchanges {
+		errc := make(chan error, len(e.Triggers)+len(e.Expects))
+		for _, trig := range e.Triggers {
+			errc <- self.trigger(trig)
+		}
+
+		// each expectation is spawned in separate go-routine
+		// expectations of an exchange are conjunctive but unordered, i.e.,
+		// only all of them arriving constitutes a pass
+		// each expectation is meant to be for a different peer, otherwise they are expected to panic
+		// testing of an exchange blocks until all expectations are decided
+		// an expectation is decided if
+		//  expected message arrives OR
+		// an unexpected message arrives (panic)
+		// times out on their individual timeout
+		for _, ex := range e.Expects {
+			// expect msg spawned to separate go routine
+			go func(exp Expect) {
+				errc <- self.expect(exp)
+			}(ex)
+		}
+
+		// time out globally or finish when all expectations satisfied
+		timeout := time.After(5 * time.Second)
+		for i := 0; i < len(e.Triggers)+len(e.Expects); i++ {
+			select {
+			case err := <-errc:
+				if err != nil {
+					return fmt.Errorf("exchange failed with: %v", err)
+				}
+			case <-timeout:
+				return fmt.Errorf("exchange %v: '%v' timed out", i, e.Label)
+			}
+		}
+	}
+	return nil
+}
+
+// TestDisconnected tests the disconnections given as arguments
+// the disconnect structs describe what disconnect error is expected on which peer
+func (self *ProtocolSession) TestDisconnected(disconnects ...*Disconnect) error {
+	expects := make(map[discover.NodeID]error)
+	for _, disconnect := range disconnects {
+		expects[disconnect.Peer] = disconnect.Error
+	}
+
+	timeout := time.After(time.Second)
+	for len(expects) > 0 {
+		select {
+		case event := <-self.events:
+			if event.Type != p2p.PeerEventTypeDrop {
+				continue
+			}
+			expectErr, ok := expects[event.Peer]
+			if !ok {
+				continue
+			}
+
+			if !(expectErr == nil && event.Error == "" || expectErr != nil && expectErr.Error() == event.Error) {
+				return fmt.Errorf("unexpected error on peer %v. expected '%v', got '%v'", event.Peer, expectErr, event.Error)
+			}
+			delete(expects, event.Peer)
+		case <-timeout:
+			return fmt.Errorf("timed out waiting for peers to disconnect")
+		}
+	}
+	return nil
+}
diff --git a/p2p/testing/protocoltester.go b/p2p/testing/protocoltester.go
new file mode 100644
index 000000000..ea5b106ff
--- /dev/null
+++ b/p2p/testing/protocoltester.go
@@ -0,0 +1,200 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+/*
+the p2p/testing package provides a unit test scheme to check simple
+protocol message exchanges with one pivot node and a number of dummy peers
+The pivot test node runs a node.Service, the dummy peers run a mock node
+that can be used to send and receive messages
+*/
+
+package testing
+
+import (
+	"fmt"
+	"sync"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/node"
+	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/p2p/discover"
+	"github.com/ethereum/go-ethereum/p2p/simulations"
+	"github.com/ethereum/go-ethereum/p2p/simulations/adapters"
+	"github.com/ethereum/go-ethereum/rpc"
+)
+
+// ProtocolTester is the tester environment used for unit testing protocol
+// message exchanges. It uses p2p/simulations framework
+type ProtocolTester struct {
+	*ProtocolSession
+	network *simulations.Network
+}
+
+// NewProtocolTester constructs a new ProtocolTester
+// it takes as argument the pivot node id, the number of dummy peers and the
+// protocol run function called on a peer connection by the p2p server
+func NewProtocolTester(t *testing.T, id discover.NodeID, n int, run func(*p2p.Peer, p2p.MsgReadWriter) error) *ProtocolTester {
+	services := adapters.Services{
+		"test": func(ctx *adapters.ServiceContext) (node.Service, error) {
+			return &testNode{run}, nil
+		},
+		"mock": func(ctx *adapters.ServiceContext) (node.Service, error) {
+			return newMockNode(), nil
+		},
+	}
+	adapter := adapters.NewSimAdapter(services)
+	net := simulations.NewNetwork(adapter, &simulations.NetworkConfig{})
+	if _, err := net.NewNodeWithConfig(&adapters.NodeConfig{
+		ID:              id,
+		EnableMsgEvents: true,
+		Services:        []string{"test"},
+	}); err != nil {
+		panic(err.Error())
+	}
+	if err := net.Start(id); err != nil {
+		panic(err.Error())
+	}
+
+	node := net.GetNode(id).Node.(*adapters.SimNode)
+	peers := make([]*adapters.NodeConfig, n)
+	peerIDs := make([]discover.NodeID, n)
+	for i := 0; i < n; i++ {
+		peers[i] = adapters.RandomNodeConfig()
+		peers[i].Services = []string{"mock"}
+		peerIDs[i] = peers[i].ID
+	}
+	events := make(chan *p2p.PeerEvent, 1000)
+	node.SubscribeEvents(events)
+	ps := &ProtocolSession{
+		Server:  node.Server(),
+		IDs:     peerIDs,
+		adapter: adapter,
+		events:  events,
+	}
+	self := &ProtocolTester{
+		ProtocolSession: ps,
+		network:         net,
+	}
+
+	self.Connect(id, peers...)
+
+	return self
+}
+
+// Stop stops the p2p server
+func (self *ProtocolTester) Stop() error {
+	self.Server.Stop()
+	return nil
+}
+
+// Connect brings up the remote peer node and connects it using the
+// p2p/simulations network connection with the in memory network adapter
+func (self *ProtocolTester) Connect(selfID discover.NodeID, peers ...*adapters.NodeConfig) {
+	for _, peer := range peers {
+		log.Trace(fmt.Sprintf("start node %v", peer.ID))
+		if _, err := self.network.NewNodeWithConfig(peer); err != nil {
+			panic(fmt.Sprintf("error starting peer %v: %v", peer.ID, err))
+		}
+		if err := self.network.Start(peer.ID); err != nil {
+			panic(fmt.Sprintf("error starting peer %v: %v", peer.ID, err))
+		}
+		log.Trace(fmt.Sprintf("connect to %v", peer.ID))
+		if err := self.network.Connect(selfID, peer.ID); err != nil {
+			panic(fmt.Sprintf("error connecting to peer %v: %v", peer.ID, err))
+		}
+	}
+
+}
+
+// testNode wraps a protocol run function and implements the node.Service
+// interface
+type testNode struct {
+	run func(*p2p.Peer, p2p.MsgReadWriter) error
+}
+
+func (t *testNode) Protocols() []p2p.Protocol {
+	return []p2p.Protocol{{
+		Length: 100,
+		Run:    t.run,
+	}}
+}
+
+func (t *testNode) APIs() []rpc.API {
+	return nil
+}
+
+func (t *testNode) Start(server *p2p.Server) error {
+	return nil
+}
+
+func (t *testNode) Stop() error {
+	return nil
+}
+
+// mockNode is a testNode which doesn't actually run a protocol, instead
+// exposing channels so that tests can manually trigger and expect certain
+// messages
+type mockNode struct {
+	testNode
+
+	trigger  chan *Trigger
+	expect   chan *Expect
+	err      chan error
+	stop     chan struct{}
+	stopOnce sync.Once
+}
+
+func newMockNode() *mockNode {
+	mock := &mockNode{
+		trigger: make(chan *Trigger),
+		expect:  make(chan *Expect),
+		err:     make(chan error),
+		stop:    make(chan struct{}),
+	}
+	mock.testNode.run = mock.Run
+	return mock
+}
+
+// Run is a protocol run function which just loops waiting for tests to
+// instruct it to either trigger or expect a message from the peer
+func (m *mockNode) Run(peer *p2p.Peer, rw p2p.MsgReadWriter) error {
+	for {
+		select {
+		case trig := <-m.trigger:
+			m.err <- p2p.Send(rw, trig.Code, trig.Msg)
+		case exp := <-m.expect:
+			m.err <- p2p.ExpectMsg(rw, exp.Code, exp.Msg)
+		case <-m.stop:
+			return nil
+		}
+	}
+}
+
+func (m *mockNode) Trigger(trig *Trigger) error {
+	m.trigger <- trig
+	return <-m.err
+}
+
+func (m *mockNode) Expect(exp *Expect) error {
+	m.expect <- exp
+	return <-m.err
+}
+
+func (m *mockNode) Stop() error {
+	m.stopOnce.Do(func() { close(m.stop) })
+	return nil
+}