From 649bf79117e30895108b7782d62daafd07bc5e6e Mon Sep 17 00:00:00 2001 From: Niall Sheridan Date: Sun, 22 May 2016 01:23:33 +0100 Subject: Use govendor --- vendor/golang.org/x/crypto/ssh/mux.go | 330 ++++++++++++++++++++++++++++++++++ 1 file changed, 330 insertions(+) create mode 100644 vendor/golang.org/x/crypto/ssh/mux.go (limited to 'vendor/golang.org/x/crypto/ssh/mux.go') diff --git a/vendor/golang.org/x/crypto/ssh/mux.go b/vendor/golang.org/x/crypto/ssh/mux.go new file mode 100644 index 0000000..f3a3ddd --- /dev/null +++ b/vendor/golang.org/x/crypto/ssh/mux.go @@ -0,0 +1,330 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssh + +import ( + "encoding/binary" + "fmt" + "io" + "log" + "sync" + "sync/atomic" +) + +// debugMux, if set, causes messages in the connection protocol to be +// logged. +const debugMux = false + +// chanList is a thread safe channel list. +type chanList struct { + // protects concurrent access to chans + sync.Mutex + + // chans are indexed by the local id of the channel, which the + // other side should send in the PeersId field. + chans []*channel + + // This is a debugging aid: it offsets all IDs by this + // amount. This helps distinguish otherwise identical + // server/client muxes + offset uint32 +} + +// Assigns a channel ID to the given channel. +func (c *chanList) add(ch *channel) uint32 { + c.Lock() + defer c.Unlock() + for i := range c.chans { + if c.chans[i] == nil { + c.chans[i] = ch + return uint32(i) + c.offset + } + } + c.chans = append(c.chans, ch) + return uint32(len(c.chans)-1) + c.offset +} + +// getChan returns the channel for the given ID. +func (c *chanList) getChan(id uint32) *channel { + id -= c.offset + + c.Lock() + defer c.Unlock() + if id < uint32(len(c.chans)) { + return c.chans[id] + } + return nil +} + +func (c *chanList) remove(id uint32) { + id -= c.offset + c.Lock() + if id < uint32(len(c.chans)) { + c.chans[id] = nil + } + c.Unlock() +} + +// dropAll forgets all channels it knows, returning them in a slice. +func (c *chanList) dropAll() []*channel { + c.Lock() + defer c.Unlock() + var r []*channel + + for _, ch := range c.chans { + if ch == nil { + continue + } + r = append(r, ch) + } + c.chans = nil + return r +} + +// mux represents the state for the SSH connection protocol, which +// multiplexes many channels onto a single packet transport. +type mux struct { + conn packetConn + chanList chanList + + incomingChannels chan NewChannel + + globalSentMu sync.Mutex + globalResponses chan interface{} + incomingRequests chan *Request + + errCond *sync.Cond + err error +} + +// When debugging, each new chanList instantiation has a different +// offset. +var globalOff uint32 + +func (m *mux) Wait() error { + m.errCond.L.Lock() + defer m.errCond.L.Unlock() + for m.err == nil { + m.errCond.Wait() + } + return m.err +} + +// newMux returns a mux that runs over the given connection. +func newMux(p packetConn) *mux { + m := &mux{ + conn: p, + incomingChannels: make(chan NewChannel, 16), + globalResponses: make(chan interface{}, 1), + incomingRequests: make(chan *Request, 16), + errCond: newCond(), + } + if debugMux { + m.chanList.offset = atomic.AddUint32(&globalOff, 1) + } + + go m.loop() + return m +} + +func (m *mux) sendMessage(msg interface{}) error { + p := Marshal(msg) + if debugMux { + log.Printf("send global(%d): %#v", m.chanList.offset, msg) + } + return m.conn.writePacket(p) +} + +func (m *mux) SendRequest(name string, wantReply bool, payload []byte) (bool, []byte, error) { + if wantReply { + m.globalSentMu.Lock() + defer m.globalSentMu.Unlock() + } + + if err := m.sendMessage(globalRequestMsg{ + Type: name, + WantReply: wantReply, + Data: payload, + }); err != nil { + return false, nil, err + } + + if !wantReply { + return false, nil, nil + } + + msg, ok := <-m.globalResponses + if !ok { + return false, nil, io.EOF + } + switch msg := msg.(type) { + case *globalRequestFailureMsg: + return false, msg.Data, nil + case *globalRequestSuccessMsg: + return true, msg.Data, nil + default: + return false, nil, fmt.Errorf("ssh: unexpected response to request: %#v", msg) + } +} + +// ackRequest must be called after processing a global request that +// has WantReply set. +func (m *mux) ackRequest(ok bool, data []byte) error { + if ok { + return m.sendMessage(globalRequestSuccessMsg{Data: data}) + } + return m.sendMessage(globalRequestFailureMsg{Data: data}) +} + +func (m *mux) Close() error { + return m.conn.Close() +} + +// loop runs the connection machine. It will process packets until an +// error is encountered. To synchronize on loop exit, use mux.Wait. +func (m *mux) loop() { + var err error + for err == nil { + err = m.onePacket() + } + + for _, ch := range m.chanList.dropAll() { + ch.close() + } + + close(m.incomingChannels) + close(m.incomingRequests) + close(m.globalResponses) + + m.conn.Close() + + m.errCond.L.Lock() + m.err = err + m.errCond.Broadcast() + m.errCond.L.Unlock() + + if debugMux { + log.Println("loop exit", err) + } +} + +// onePacket reads and processes one packet. +func (m *mux) onePacket() error { + packet, err := m.conn.readPacket() + if err != nil { + return err + } + + if debugMux { + if packet[0] == msgChannelData || packet[0] == msgChannelExtendedData { + log.Printf("decoding(%d): data packet - %d bytes", m.chanList.offset, len(packet)) + } else { + p, _ := decode(packet) + log.Printf("decoding(%d): %d %#v - %d bytes", m.chanList.offset, packet[0], p, len(packet)) + } + } + + switch packet[0] { + case msgChannelOpen: + return m.handleChannelOpen(packet) + case msgGlobalRequest, msgRequestSuccess, msgRequestFailure: + return m.handleGlobalPacket(packet) + } + + // assume a channel packet. + if len(packet) < 5 { + return parseError(packet[0]) + } + id := binary.BigEndian.Uint32(packet[1:]) + ch := m.chanList.getChan(id) + if ch == nil { + return fmt.Errorf("ssh: invalid channel %d", id) + } + + return ch.handlePacket(packet) +} + +func (m *mux) handleGlobalPacket(packet []byte) error { + msg, err := decode(packet) + if err != nil { + return err + } + + switch msg := msg.(type) { + case *globalRequestMsg: + m.incomingRequests <- &Request{ + Type: msg.Type, + WantReply: msg.WantReply, + Payload: msg.Data, + mux: m, + } + case *globalRequestSuccessMsg, *globalRequestFailureMsg: + m.globalResponses <- msg + default: + panic(fmt.Sprintf("not a global message %#v", msg)) + } + + return nil +} + +// handleChannelOpen schedules a channel to be Accept()ed. +func (m *mux) handleChannelOpen(packet []byte) error { + var msg channelOpenMsg + if err := Unmarshal(packet, &msg); err != nil { + return err + } + + if msg.MaxPacketSize < minPacketLength || msg.MaxPacketSize > 1<<31 { + failMsg := channelOpenFailureMsg{ + PeersId: msg.PeersId, + Reason: ConnectionFailed, + Message: "invalid request", + Language: "en_US.UTF-8", + } + return m.sendMessage(failMsg) + } + + c := m.newChannel(msg.ChanType, channelInbound, msg.TypeSpecificData) + c.remoteId = msg.PeersId + c.maxRemotePayload = msg.MaxPacketSize + c.remoteWin.add(msg.PeersWindow) + m.incomingChannels <- c + return nil +} + +func (m *mux) OpenChannel(chanType string, extra []byte) (Channel, <-chan *Request, error) { + ch, err := m.openChannel(chanType, extra) + if err != nil { + return nil, nil, err + } + + return ch, ch.incomingRequests, nil +} + +func (m *mux) openChannel(chanType string, extra []byte) (*channel, error) { + ch := m.newChannel(chanType, channelOutbound, extra) + + ch.maxIncomingPayload = channelMaxPacket + + open := channelOpenMsg{ + ChanType: chanType, + PeersWindow: ch.myWindow, + MaxPacketSize: ch.maxIncomingPayload, + TypeSpecificData: extra, + PeersId: ch.localId, + } + if err := m.sendMessage(open); err != nil { + return nil, err + } + + switch msg := (<-ch.msg).(type) { + case *channelOpenConfirmMsg: + return ch, nil + case *channelOpenFailureMsg: + return nil, &OpenChannelError{msg.Reason, msg.Message} + default: + return nil, fmt.Errorf("ssh: unexpected packet in response to channel open: %T", msg) + } +} -- cgit v1.2.3