2014-10-23 15:57:54 +00:00
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package p2p
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import (
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2015-02-06 23:13:22 +00:00
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"errors"
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2014-10-23 15:57:54 +00:00
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"fmt"
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2014-11-21 20:48:49 +00:00
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"io"
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"io/ioutil"
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2014-10-23 15:57:54 +00:00
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"net"
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2014-11-21 20:48:49 +00:00
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"sort"
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"sync"
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"time"
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"github.com/ethereum/go-ethereum/logger"
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2015-02-05 02:07:58 +00:00
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"github.com/ethereum/go-ethereum/p2p/discover"
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"github.com/ethereum/go-ethereum/rlp"
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2014-10-23 15:57:54 +00:00
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)
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2015-02-05 02:07:58 +00:00
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const (
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baseProtocolVersion = 2
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baseProtocolLength = uint64(16)
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baseProtocolMaxMsgSize = 10 * 1024 * 1024
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2015-02-13 13:44:00 +00:00
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disconnectGracePeriod = 2 * time.Second
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2015-02-05 02:07:58 +00:00
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)
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2014-11-21 20:48:49 +00:00
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2015-02-05 02:07:58 +00:00
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const (
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// devp2p message codes
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handshakeMsg = 0x00
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discMsg = 0x01
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pingMsg = 0x02
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pongMsg = 0x03
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getPeersMsg = 0x04
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peersMsg = 0x05
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)
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2014-11-21 20:48:49 +00:00
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2015-02-05 02:07:58 +00:00
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// handshake is the RLP structure of the protocol handshake.
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type handshake struct {
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Version uint64
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Name string
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Caps []Cap
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ListenPort uint64
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NodeID discover.NodeID
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2014-11-21 20:48:49 +00:00
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}
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2015-02-05 02:07:58 +00:00
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// Peer represents a connected remote node.
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2014-10-23 15:57:54 +00:00
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type Peer struct {
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2014-11-21 20:48:49 +00:00
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// Peers have all the log methods.
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// Use them to display messages related to the peer.
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*logger.Logger
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2015-02-05 02:07:58 +00:00
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infoMu sync.Mutex
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name string
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caps []Cap
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2014-11-21 20:48:49 +00:00
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2015-02-05 02:07:58 +00:00
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ourID, remoteID *discover.NodeID
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ourName string
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rw *frameRW
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2014-11-21 20:48:49 +00:00
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// These fields maintain the running protocols.
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2015-02-05 02:07:58 +00:00
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protocols []Protocol
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runlock sync.RWMutex // protects running
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running map[string]*proto
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2014-11-21 20:48:49 +00:00
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2015-02-06 23:13:22 +00:00
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// disables protocol handshake, for testing
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noHandshake bool
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2014-11-21 20:48:49 +00:00
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protoWG sync.WaitGroup
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protoErr chan error
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closed chan struct{}
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disc chan DiscReason
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}
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// NewPeer returns a peer for testing purposes.
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2015-02-05 02:07:58 +00:00
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func NewPeer(id discover.NodeID, name string, caps []Cap) *Peer {
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2014-11-21 20:48:49 +00:00
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conn, _ := net.Pipe()
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2015-02-05 02:07:58 +00:00
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peer := newPeer(conn, nil, "", nil, &id)
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peer.setHandshakeInfo(name, caps)
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close(peer.closed) // ensures Disconnect doesn't block
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2014-10-23 15:57:54 +00:00
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return peer
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}
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2015-02-05 02:07:58 +00:00
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// ID returns the node's public key.
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func (p *Peer) ID() discover.NodeID {
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return *p.remoteID
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2014-11-21 20:48:49 +00:00
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}
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2015-02-05 02:07:58 +00:00
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// Name returns the node name that the remote node advertised.
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func (p *Peer) Name() string {
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// this needs a lock because the information is part of the
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// protocol handshake.
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p.infoMu.Lock()
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name := p.name
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p.infoMu.Unlock()
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return name
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2015-01-18 07:59:54 +00:00
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}
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2014-11-21 20:48:49 +00:00
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// Caps returns the capabilities (supported subprotocols) of the remote peer.
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func (p *Peer) Caps() []Cap {
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2015-02-05 02:07:58 +00:00
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// this needs a lock because the information is part of the
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// protocol handshake.
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p.infoMu.Lock()
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caps := p.caps
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p.infoMu.Unlock()
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return caps
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2014-11-21 20:48:49 +00:00
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}
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// RemoteAddr returns the remote address of the network connection.
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func (p *Peer) RemoteAddr() net.Addr {
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2015-02-05 02:07:58 +00:00
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return p.rw.RemoteAddr()
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2014-11-21 20:48:49 +00:00
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}
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// LocalAddr returns the local address of the network connection.
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func (p *Peer) LocalAddr() net.Addr {
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2015-02-05 02:07:58 +00:00
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return p.rw.LocalAddr()
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2014-11-21 20:48:49 +00:00
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}
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// Disconnect terminates the peer connection with the given reason.
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// It returns immediately and does not wait until the connection is closed.
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func (p *Peer) Disconnect(reason DiscReason) {
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select {
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case p.disc <- reason:
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case <-p.closed:
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}
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}
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// String implements fmt.Stringer.
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func (p *Peer) String() string {
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2015-02-06 23:13:22 +00:00
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return fmt.Sprintf("Peer %.8x %v", p.remoteID[:], p.RemoteAddr())
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2015-02-05 02:07:58 +00:00
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}
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func newPeer(conn net.Conn, protocols []Protocol, ourName string, ourID, remoteID *discover.NodeID) *Peer {
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2015-02-06 23:13:22 +00:00
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logtag := fmt.Sprintf("Peer %.8x %v", remoteID[:], conn.RemoteAddr())
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2015-02-05 02:07:58 +00:00
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return &Peer{
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Logger: logger.NewLogger(logtag),
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rw: newFrameRW(conn, msgWriteTimeout),
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ourID: ourID,
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ourName: ourName,
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remoteID: remoteID,
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protocols: protocols,
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running: make(map[string]*proto),
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disc: make(chan DiscReason),
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protoErr: make(chan error),
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closed: make(chan struct{}),
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2014-10-23 15:57:54 +00:00
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}
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2014-11-21 20:48:49 +00:00
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}
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2015-02-05 02:07:58 +00:00
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func (p *Peer) setHandshakeInfo(name string, caps []Cap) {
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p.infoMu.Lock()
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p.name = name
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p.caps = caps
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p.infoMu.Unlock()
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}
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2014-11-21 20:48:49 +00:00
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2015-02-05 02:07:58 +00:00
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func (p *Peer) run() DiscReason {
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var readErr = make(chan error, 1)
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2014-11-21 20:48:49 +00:00
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defer p.closeProtocols()
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defer close(p.closed)
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2015-02-05 02:07:58 +00:00
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go func() { readErr <- p.readLoop() }()
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2014-11-21 20:48:49 +00:00
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2015-02-06 23:13:22 +00:00
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if !p.noHandshake {
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2015-02-05 02:07:58 +00:00
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if err := writeProtocolHandshake(p.rw, p.ourName, *p.ourID, p.protocols); err != nil {
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p.DebugDetailf("Protocol handshake error: %v\n", err)
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2015-02-06 23:13:22 +00:00
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p.rw.Close()
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2015-02-05 02:07:58 +00:00
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return DiscProtocolError
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2015-01-18 07:59:54 +00:00
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}
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}
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2015-02-06 23:13:22 +00:00
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// Wait for an error or disconnect.
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2015-02-05 02:07:58 +00:00
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var reason DiscReason
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select {
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case err := <-readErr:
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// We rely on protocols to abort if there is a write error. It
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// might be more robust to handle them here as well.
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p.DebugDetailf("Read error: %v\n", err)
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2015-02-06 23:13:22 +00:00
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p.rw.Close()
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return DiscNetworkError
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2015-02-05 02:07:58 +00:00
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case err := <-p.protoErr:
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reason = discReasonForError(err)
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case reason = <-p.disc:
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2014-11-21 20:48:49 +00:00
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}
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2015-02-06 23:13:22 +00:00
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p.politeDisconnect(reason)
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// Wait for readLoop. It will end because conn is now closed.
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<-readErr
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2015-02-05 02:07:58 +00:00
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p.Debugf("Disconnected: %v\n", reason)
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return reason
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}
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2014-11-21 20:48:49 +00:00
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2015-02-05 02:07:58 +00:00
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func (p *Peer) politeDisconnect(reason DiscReason) {
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2014-11-21 20:48:49 +00:00
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done := make(chan struct{})
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go func() {
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2015-02-05 02:07:58 +00:00
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EncodeMsg(p.rw, discMsg, uint(reason))
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2015-02-06 23:13:22 +00:00
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// Wait for the other side to close the connection.
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// Discard any data that they send until then.
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2015-02-05 02:07:58 +00:00
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io.Copy(ioutil.Discard, p.rw)
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2014-11-21 20:48:49 +00:00
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close(done)
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}()
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select {
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case <-done:
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case <-time.After(disconnectGracePeriod):
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}
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2015-02-06 23:13:22 +00:00
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p.rw.Close()
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2014-11-21 20:48:49 +00:00
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}
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2015-02-05 02:07:58 +00:00
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func (p *Peer) readLoop() error {
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2015-02-06 23:13:22 +00:00
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if !p.noHandshake {
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2015-02-05 02:07:58 +00:00
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if err := readProtocolHandshake(p, p.rw); err != nil {
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return err
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2014-11-21 20:48:49 +00:00
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}
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}
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2015-02-05 02:07:58 +00:00
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for {
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msg, err := p.rw.ReadMsg()
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if err != nil {
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return err
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}
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if err = p.handle(msg); err != nil {
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return err
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}
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}
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return nil
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2014-11-21 20:48:49 +00:00
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}
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2015-02-05 02:07:58 +00:00
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func (p *Peer) handle(msg Msg) error {
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switch {
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case msg.Code == pingMsg:
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msg.Discard()
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go EncodeMsg(p.rw, pongMsg)
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case msg.Code == discMsg:
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var reason DiscReason
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// no need to discard or for error checking, we'll close the
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// connection after this.
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rlp.Decode(msg.Payload, &reason)
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p.Disconnect(DiscRequested)
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return discRequestedError(reason)
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case msg.Code < baseProtocolLength:
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// ignore other base protocol messages
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return msg.Discard()
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default:
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// it's a subprotocol message
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proto, err := p.getProto(msg.Code)
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2014-11-21 20:48:49 +00:00
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if err != nil {
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2015-02-05 02:07:58 +00:00
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return fmt.Errorf("msg code out of range: %v", msg.Code)
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2014-11-21 20:48:49 +00:00
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}
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proto.in <- msg
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}
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2015-02-05 02:07:58 +00:00
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return nil
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2014-11-21 20:48:49 +00:00
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}
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2015-02-05 02:07:58 +00:00
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func readProtocolHandshake(p *Peer, rw MsgReadWriter) error {
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// read and handle remote handshake
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msg, err := rw.ReadMsg()
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if err != nil {
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return err
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2015-01-26 16:16:23 +00:00
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}
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2015-02-05 02:07:58 +00:00
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if msg.Code != handshakeMsg {
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return newPeerError(errProtocolBreach, "expected handshake, got %x", msg.Code)
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2015-01-21 16:53:13 +00:00
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}
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2015-02-05 02:07:58 +00:00
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if msg.Size > baseProtocolMaxMsgSize {
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2015-02-06 23:13:22 +00:00
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return newPeerError(errInvalidMsg, "message too big")
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2015-01-19 11:21:13 +00:00
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}
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2015-02-05 02:07:58 +00:00
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var hs handshake
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if err := msg.Decode(&hs); err != nil {
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return err
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2015-01-26 16:16:23 +00:00
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}
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2015-02-05 02:07:58 +00:00
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// validate handshake info
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if hs.Version != baseProtocolVersion {
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return newPeerError(errP2PVersionMismatch, "required version %d, received %d\n",
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baseProtocolVersion, hs.Version)
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2015-01-19 11:21:13 +00:00
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}
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2015-02-05 02:07:58 +00:00
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if hs.NodeID == *p.remoteID {
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return newPeerError(errPubkeyForbidden, "node ID mismatch")
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2015-01-19 23:42:13 +00:00
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}
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2015-02-05 02:07:58 +00:00
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// TODO: remove Caps with empty name
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p.setHandshakeInfo(hs.Name, hs.Caps)
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p.startSubprotocols(hs.Caps)
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return nil
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2015-01-18 07:59:54 +00:00
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}
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2015-02-05 02:07:58 +00:00
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func writeProtocolHandshake(w MsgWriter, name string, id discover.NodeID, ps []Protocol) error {
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var caps []interface{}
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for _, proto := range ps {
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caps = append(caps, proto.cap())
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}
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return EncodeMsg(w, handshakeMsg, baseProtocolVersion, name, caps, 0, id)
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2014-11-21 20:48:49 +00:00
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}
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// startProtocols starts matching named subprotocols.
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func (p *Peer) startSubprotocols(caps []Cap) {
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sort.Sort(capsByName(caps))
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p.runlock.Lock()
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defer p.runlock.Unlock()
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offset := baseProtocolLength
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outer:
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for _, cap := range caps {
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for _, proto := range p.protocols {
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if proto.Name == cap.Name &&
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proto.Version == cap.Version &&
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p.running[cap.Name] == nil {
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p.running[cap.Name] = p.startProto(offset, proto)
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offset += proto.Length
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continue outer
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}
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}
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}
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}
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func (p *Peer) startProto(offset uint64, impl Protocol) *proto {
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2015-02-05 02:07:58 +00:00
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p.DebugDetailf("Starting protocol %s/%d\n", impl.Name, impl.Version)
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2014-11-21 20:48:49 +00:00
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rw := &proto{
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2015-02-05 02:07:58 +00:00
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name: impl.Name,
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2014-11-21 20:48:49 +00:00
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in: make(chan Msg),
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offset: offset,
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maxcode: impl.Length,
|
2015-02-05 02:07:58 +00:00
|
|
|
w: p.rw,
|
2014-11-21 20:48:49 +00:00
|
|
|
}
|
|
|
|
p.protoWG.Add(1)
|
|
|
|
go func() {
|
|
|
|
err := impl.Run(p, rw)
|
|
|
|
if err == nil {
|
2015-02-05 02:07:58 +00:00
|
|
|
p.DebugDetailf("Protocol %s/%d returned\n", impl.Name, impl.Version)
|
2015-02-06 23:13:22 +00:00
|
|
|
err = errors.New("protocol returned")
|
2014-11-21 20:48:49 +00:00
|
|
|
} else {
|
2015-02-05 02:07:58 +00:00
|
|
|
p.DebugDetailf("Protocol %s/%d error: %v\n", impl.Name, impl.Version, err)
|
2014-11-21 20:48:49 +00:00
|
|
|
}
|
|
|
|
select {
|
|
|
|
case p.protoErr <- err:
|
|
|
|
case <-p.closed:
|
|
|
|
}
|
|
|
|
p.protoWG.Done()
|
|
|
|
}()
|
|
|
|
return rw
|
|
|
|
}
|
|
|
|
|
|
|
|
// getProto finds the protocol responsible for handling
|
|
|
|
// the given message code.
|
|
|
|
func (p *Peer) getProto(code uint64) (*proto, error) {
|
|
|
|
p.runlock.RLock()
|
|
|
|
defer p.runlock.RUnlock()
|
|
|
|
for _, proto := range p.running {
|
|
|
|
if code >= proto.offset && code < proto.offset+proto.maxcode {
|
|
|
|
return proto, nil
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return nil, newPeerError(errInvalidMsgCode, "%d", code)
|
|
|
|
}
|
|
|
|
|
|
|
|
func (p *Peer) closeProtocols() {
|
|
|
|
p.runlock.RLock()
|
|
|
|
for _, p := range p.running {
|
|
|
|
close(p.in)
|
|
|
|
}
|
|
|
|
p.runlock.RUnlock()
|
|
|
|
p.protoWG.Wait()
|
|
|
|
}
|
|
|
|
|
|
|
|
// writeProtoMsg sends the given message on behalf of the given named protocol.
|
2015-02-05 02:07:58 +00:00
|
|
|
// this exists because of Server.Broadcast.
|
2014-11-21 20:48:49 +00:00
|
|
|
func (p *Peer) writeProtoMsg(protoName string, msg Msg) error {
|
|
|
|
p.runlock.RLock()
|
|
|
|
proto, ok := p.running[protoName]
|
|
|
|
p.runlock.RUnlock()
|
|
|
|
if !ok {
|
|
|
|
return fmt.Errorf("protocol %s not handled by peer", protoName)
|
|
|
|
}
|
|
|
|
if msg.Code >= proto.maxcode {
|
|
|
|
return newPeerError(errInvalidMsgCode, "code %x is out of range for protocol %q", msg.Code, protoName)
|
|
|
|
}
|
|
|
|
msg.Code += proto.offset
|
2015-02-05 02:07:58 +00:00
|
|
|
return p.rw.WriteMsg(msg)
|
2014-11-21 20:48:49 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
type proto struct {
|
|
|
|
name string
|
|
|
|
in chan Msg
|
|
|
|
maxcode, offset uint64
|
2015-02-05 02:07:58 +00:00
|
|
|
w MsgWriter
|
2014-11-21 20:48:49 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
func (rw *proto) WriteMsg(msg Msg) error {
|
|
|
|
if msg.Code >= rw.maxcode {
|
|
|
|
return newPeerError(errInvalidMsgCode, "not handled")
|
|
|
|
}
|
|
|
|
msg.Code += rw.offset
|
2015-02-05 02:07:58 +00:00
|
|
|
return rw.w.WriteMsg(msg)
|
2014-10-23 15:57:54 +00:00
|
|
|
}
|
|
|
|
|
2014-11-21 20:48:49 +00:00
|
|
|
func (rw *proto) ReadMsg() (Msg, error) {
|
|
|
|
msg, ok := <-rw.in
|
|
|
|
if !ok {
|
|
|
|
return msg, io.EOF
|
|
|
|
}
|
|
|
|
msg.Code -= rw.offset
|
|
|
|
return msg, nil
|
2014-10-23 15:57:54 +00:00
|
|
|
}
|