path: root/p2p/server_test.go

package p2p

import (
    "bytes"
    "crypto/ecdsa"
    "io"
    "math/rand"
    "net"
    "sync"
    "testing"
    "time"

    "github.com/ethereum/go-ethereum/crypto"
    "github.com/ethereum/go-ethereum/crypto/sha3"
    "github.com/ethereum/go-ethereum/p2p/discover"
)

func startTestServer(t *testing.T, pf newPeerHook) *Server {
    server := &Server{
        Name:        "test",
        MaxPeers:    10,
        ListenAddr:  "127.0.0.1:0",
        PrivateKey:  newkey(),
        newPeerHook: pf,
        setupFunc: func(fd net.Conn, prv *ecdsa.PrivateKey, our *protoHandshake, dial *discover.Node, atcap bool) (*conn, error) {
            id := randomID()
            rw := newRlpxFrameRW(fd, secrets{
                MAC:        zero16,
                AES:        zero16,
                IngressMAC: sha3.NewKeccak256(),
                EgressMAC:  sha3.NewKeccak256(),
            })
            return &conn{
                MsgReadWriter:  rw,
                protoHandshake: &protoHandshake{ID: id, Version: baseProtocolVersion},
            }, nil
        },
    }
    if err := server.Start(); err != nil {
        t.Fatalf("Could not start server: %v", err)
    }
    return server
}

func TestServerListen(t *testing.T) {
    defer testlog(t).detach()

    // start the test server
    connected := make(chan *Peer)
    srv := startTestServer(t, func(p *Peer) {
        if p == nil {
            t.Error("peer func called with nil conn")
        }
        connected <- p
    })
    defer close(connected)
    defer srv.Stop()

    // dial the test server
    conn, err := net.DialTimeout("tcp", srv.ListenAddr, 5*time.Second)
    if err != nil {
        t.Fatalf("could not dial: %v", err)
    }
    defer conn.Close()

    select {
    case peer := <-connected:
        if peer.LocalAddr().String() != conn.RemoteAddr().String() {
            t.Errorf("peer started with wrong conn: got %v, want %v",
                peer.LocalAddr(), conn.RemoteAddr())
        }
    case <-time.After(1 * time.Second):
        t.Error("server did not accept within one second")
    }
}

func TestServerDial(t *testing.T) {
    defer testlog(t).detach()

    // run a one-shot TCP server to handle the connection.
    listener, err := net.Listen("tcp", "127.0.0.1:0")
    if err != nil {
        t.Fatalf("could not setup listener: %v")
    }
    defer listener.Close()
    accepted := make(chan net.Conn)
    go func() {
        conn, err := listener.Accept()
        if err != nil {
            t.Error("accept error:", err)
            return
        }
        conn.Close()
        accepted <- conn
    }()

    // start the server
    connected := make(chan *Peer)
    srv := startTestServer(t, func(p *Peer) { connected <- p })
    defer close(connected)
    defer srv.Stop()

    // tell the server to connect
    tcpAddr := listener.Addr().(*net.TCPAddr)
    srv.SuggestPeer(&discover.Node{IP: tcpAddr.IP, TCP: uint16(tcpAddr.Port)})

    select {
    case conn := <-accepted:
        select {
        case peer := <-connected:
            if peer.RemoteAddr().String() != conn.LocalAddr().String() {
                t.Errorf("peer started with wrong conn: got %v, want %v",
                    peer.RemoteAddr(), conn.LocalAddr())
            }
            // TODO: validate more fields
        case <-time.After(1 * time.Second):
            t.Error("server did not launch peer within one second")
        }

    case <-time.After(1 * time.Second):
        t.Error("server did not connect within one second")
    }
}

func TestServerBroadcast(t *testing.T) {
    defer testlog(t).detach()

    var connected sync.WaitGroup
    srv := startTestServer(t, func(p *Peer) {
        p.running = matchProtocols([]Protocol{discard}, []Cap{discard.cap()}, p.rw)
        connected.Done()
    })
    defer srv.Stop()

    // create a few peers
    var conns = make([]net.Conn, 8)
    connected.Add(len(conns))
    deadline := time.Now().Add(3 * time.Second)
    dialer := &net.Dialer{Deadline: deadline}
    for i := range conns {
        conn, err := dialer.Dial("tcp", srv.ListenAddr)
        if err != nil {
            t.Fatalf("conn %d: dial error: %v", i, err)
        }
        defer conn.Close()
        conn.SetDeadline(deadline)
        conns[i] = conn
    }
    connected.Wait()

    // broadcast one message
    srv.Broadcast("discard", 0, []string{"foo"})
    golden := unhex("66e94d166f0a2c3b884cfa59ca34")

    // check that the message has been written everywhere
    for i, conn := range conns {
        buf := make([]byte, len(golden))
        if _, err := io.ReadFull(conn, buf); err != nil {
            t.Errorf("conn %d: read error: %v", i, err)
        } else if !bytes.Equal(buf, golden) {
            t.Errorf("conn %d: msg mismatch\ngot:  %x\nwant: %x", i, buf, golden)
        }
    }
}

// This test checks that connections are disconnected
// just after the encryption handshake when the server is
// at capacity.
//
// It also serves as a light-weight integration test.
func TestServerDisconnectAtCap(t *testing.T) {
    defer testlog(t).detach()

    started := make(chan *Peer)
    srv := &Server{
        ListenAddr: "127.0.0.1:0",
        PrivateKey: newkey(),
        MaxPeers:   10,
        NoDial:     true,
        // This hook signals that the peer was actually started. We
        // need to wait for the peer to be started before dialing the
        // next connection to get a deterministic peer count.
        newPeerHook: func(p *Peer) { started <- p },
    }
    if err := srv.Start(); err != nil {
        t.Fatal(err)
    }
    defer srv.Stop()

    nconns := srv.MaxPeers + 1
    dialer := &net.Dialer{Deadline: time.Now().Add(3 * time.Second)}
    for i := 0; i < nconns; i++ {
        conn, err := dialer.Dial("tcp", srv.ListenAddr)
        if err != nil {
            t.Fatalf("conn %d: dial error: %v", i, err)
        }
        // Close the connection when the test ends, before
        // shutting down the server.
        defer conn.Close()
        // Run the handshakes just like a real peer would.
        key := newkey()
        hs := &protoHandshake{Version: baseProtocolVersion, ID: discover.PubkeyID(&key.PublicKey)}
        _, err = setupConn(conn, key, hs, srv.Self(), false)
        if i == nconns-1 {
            // When handling the last connection, the server should
            // disconnect immediately instead of running the protocol
            // handshake.
            if err != DiscTooManyPeers {
                t.Errorf("conn %d: got error %q, expected %q", i, err, DiscTooManyPeers)
            }
        } else {
            // For all earlier connections, the handshake should go through.
            if err != nil {
                t.Fatalf("conn %d: unexpected error: %v", i, err)
            }
            // Wait for runPeer to be started.
            <-started
        }
    }
}

func newkey() *ecdsa.PrivateKey {
    key, err := crypto.GenerateKey()
    if err != nil {
        panic("couldn't generate key: " + err.Error())
    }
    return key
}

func randomID() (id discover.NodeID) {
    for i := range id {
        id[i] = byte(rand.Intn(255))
    }
    return id
}