first commit

build/node_modules/ssh2/lib/Channel.js

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+var inherits = require('util').inherits;
+var DuplexStream = require('stream').Duplex;
+var ReadableStream = require('stream').Readable;
+var WritableStream = require('stream').Writable;
+
+var STDERR = require('ssh2-streams').constants.CHANNEL_EXTENDED_DATATYPE.STDERR;
+
+var PACKET_SIZE = 32 * 1024;
+var MAX_WINDOW = 1 * 1024 * 1024;
+var WINDOW_THRESHOLD = MAX_WINDOW / 2;
+var CUSTOM_EVENTS = [
+  'CHANNEL_EOF',
+  'CHANNEL_CLOSE',
+  'CHANNEL_DATA',
+  'CHANNEL_EXTENDED_DATA',
+  'CHANNEL_WINDOW_ADJUST',
+  'CHANNEL_SUCCESS',
+  'CHANNEL_FAILURE',
+  'CHANNEL_REQUEST'
+];
+var CUSTOM_EVENTS_LEN = CUSTOM_EVENTS.length;
+
+function Channel(info, client, opts) {
+  var streamOpts = {
+    highWaterMark: MAX_WINDOW,
+    allowHalfOpen: (!opts || (opts && opts.allowHalfOpen !== false))
+  };
+
+  this.allowHalfOpen = streamOpts.allowHalfOpen;
+
+  DuplexStream.call(this, streamOpts);
+
+  var self = this;
+  var server = opts && opts.server;
+
+  this.server = server;
+  this.type = info.type;
+  this.subtype = undefined;
+  /*
+    incoming and outgoing contain these properties:
+    {
+      id: undefined,
+      window: undefined,
+      packetSize: undefined,
+      state: 'closed'
+    }
+  */
+  var incoming = this.incoming = info.incoming;
+  var incomingId = incoming.id;
+  var outgoing = this.outgoing = info.outgoing;
+  var callbacks = this._callbacks = [];
+  var exitCode;
+  var exitSignal;
+  var exitDump;
+  var exitDesc;
+  var exitLang;
+
+  this._client = client;
+  this._hasX11 = false;
+
+  var channels = client._channels;
+  var sshstream = client._sshstream;
+
+  function ondrain() {
+    if (self._waitClientDrain) {
+      self._waitClientDrain = false;
+      if (!self._waitWindow) {
+        if (self._chunk)
+          self._write(self._chunk, null, self._chunkcb);
+        else if (self._chunkcb)
+          self._chunkcb();
+        else if (self._chunkErr)
+          self.stderr._write(self._chunkErr, null, self._chunkcbErr);
+        else if (self._chunkcbErr)
+          self._chunkcbErr();
+      }
+    }
+  }
+  client._sock.on('drain', ondrain);
+
+  sshstream.once('CHANNEL_EOF:' + incomingId, function() {
+    if (incoming.state === 'closed' || incoming.state === 'eof')
+      return;
+    incoming.state = 'eof';
+
+    if (self.readable)
+      self.push(null);
+    if (!server && self.stderr.readable)
+      self.stderr.push(null);
+  }).once('CHANNEL_CLOSE:' + incomingId, function() {
+    if (incoming.state === 'closed')
+      return;
+    incoming.state = 'closed';
+
+    if (self.readable)
+      self.push(null);
+    if (server && self.stderr.writable)
+      self.stderr.end();
+    else if (!server && self.stderr.readable)
+      self.stderr.push(null);
+
+    if (outgoing.state === 'open' || outgoing.state === 'eof')
+      self.close();
+    if (outgoing.state === 'closing')
+      outgoing.state = 'closed';
+
+    delete channels[incomingId];
+
+    var state = self._writableState;
+    client._sock.removeListener('drain', ondrain);
+    if (!state.ending && !state.finished)
+      self.end();
+
+    // Take care of any outstanding channel requests
+    self._callbacks = [];
+    for (var i = 0; i < callbacks.length; ++i)
+      callbacks[i](true);
+    callbacks = self._callbacks;
+
+    if (!server) {
+      // align more with node child processes, where the close event gets the
+      // same arguments as the exit event
+      if (!self.readable) {
+        if (exitCode === null) {
+          self.emit('close', exitCode, exitSignal, exitDump, exitDesc,
+                    exitLang);
+        } else
+          self.emit('close', exitCode);
+      } else {
+        self.once('end', function() {
+          if (exitCode === null) {
+            self.emit('close', exitCode, exitSignal, exitDump, exitDesc,
+                      exitLang);
+          } else
+            self.emit('close', exitCode);
+        });
+      }
+
+      if (!self.stderr.readable)
+        self.stderr.emit('close');
+      else {
+        self.stderr.once('end', function() {
+          self.stderr.emit('close');
+        });
+      }
+    } else { // Server mode
+      if (!self.readable)
+        self.emit('close');
+      else {
+        self.once('end', function() {
+          self.emit('close');
+        });
+      }
+    }
+
+    for (var i = 0; i < CUSTOM_EVENTS_LEN; ++i)
+      sshstream.removeAllListeners(CUSTOM_EVENTS[i] + ':' + incomingId);
+  }).on('CHANNEL_DATA:' + incomingId, function(data) {
+    // the remote party should not be sending us data if there is no window
+    // space available ...
+    if (incoming.window === 0)
+      return;
+
+    incoming.window -= data.length;
+
+    if (!self.push(data)) {
+      self._waitChanDrain = true;
+      return;
+    }
+
+    if (incoming.window <= WINDOW_THRESHOLD)
+      windowAdjust(self);
+  }).on('CHANNEL_WINDOW_ADJUST:' + incomingId, function(amt) {
+    // the server is allowing us to send `amt` more bytes of data
+    outgoing.window += amt;
+
+    if (self._waitWindow) {
+      self._waitWindow = false;
+      if (!self._waitClientDrain) {
+        if (self._chunk)
+          self._write(self._chunk, null, self._chunkcb);
+        else if (self._chunkcb)
+          self._chunkcb();
+        else if (self._chunkErr)
+          self.stderr._write(self._chunkErr, null, self._chunkcbErr);
+        else if (self._chunkcbErr)
+          self._chunkcbErr();
+      }
+    }
+  }).on('CHANNEL_SUCCESS:' + incomingId, function() {
+    if (server) {
+      sshstream._kalast = Date.now();
+      sshstream._kacnt = 0;
+    } else
+      client._resetKA();
+    if (callbacks.length)
+      callbacks.shift()(false);
+  }).on('CHANNEL_FAILURE:' + incomingId, function() {
+    if (server) {
+      sshstream._kalast = Date.now();
+      sshstream._kacnt = 0;
+    } else
+      client._resetKA();
+    if (callbacks.length)
+      callbacks.shift()(true);
+  }).on('CHANNEL_REQUEST:' + incomingId, function(info) {
+    if (!server) {
+      if (info.request === 'exit-status') {
+        self.emit('exit', exitCode = info.code);
+        return;
+      } else if (info.request === 'exit-signal') {
+        self.emit('exit',
+                  exitCode = null,
+                  exitSignal = 'SIG' + info.signal,
+                  exitDump = info.coredump,
+                  exitDesc = info.description,
+                  exitLang = info.lang);
+        return;
+      }
+    }
+
+    // keepalive request? OpenSSH will send one as a channel request if there
+    // is a channel open
+
+    if (info.wantReply)
+      sshstream.channelFailure(outgoing.id);
+  });
+
+  this.stdin = this.stdout = this;
+
+  if (server)
+    this.stderr = new ServerStderr(this);
+  else {
+    this.stderr = new ReadableStream(streamOpts);
+    this.stderr._read = function(n) {
+      if (self._waitChanDrain) {
+        self._waitChanDrain = false;
+        if (incoming.window <= WINDOW_THRESHOLD)
+          windowAdjust(self);
+      }
+    };
+
+    sshstream.on('CHANNEL_EXTENDED_DATA:' + incomingId,
+      function(type, data) {
+        // the remote party should not be sending us data if there is no window
+        // space available ...
+        if (incoming.window === 0)
+          return;
+
+        incoming.window -= data.length;
+
+        if (!self.stderr.push(data)) {
+          self._waitChanDrain = true;
+          return;
+        }
+
+        if (incoming.window <= WINDOW_THRESHOLD)
+          windowAdjust(self);
+      }
+    );
+  }
+
+  // outgoing data
+  this._waitClientDrain = false; // Client stream-level backpressure
+  this._waitWindow = false; // SSH-level backpressure
+
+  // incoming data
+  this._waitChanDrain = false; // Channel Readable side backpressure
+
+  this._chunk = undefined;
+  this._chunkcb = undefined;
+  this._chunkErr = undefined;
+  this._chunkcbErr = undefined;
+
+  function onFinish() {
+    self.eof();
+    if (server || (!server && !self.allowHalfOpen))
+      self.close();
+    self.writable = false;
+  }
+  this.on('finish', onFinish)
+      .on('prefinish', onFinish); // for node v0.11+
+  function onEnd() {
+    self.readable = false;
+  }
+  this.on('end', onEnd)
+      .on('close', onEnd);
+}
+inherits(Channel, DuplexStream);
+
+Channel.prototype.eof = function() {
+  var ret = true;
+  var outgoing = this.outgoing;
+
+  if (outgoing.state === 'open') {
+    outgoing.state = 'eof';
+    ret = this._client._sshstream.channelEOF(outgoing.id);
+  }
+
+  return ret;
+};
+
+Channel.prototype.close = function() {
+  var ret = true;
+  var outgoing = this.outgoing;
+
+  if (outgoing.state === 'open' || outgoing.state === 'eof') {
+    outgoing.state = 'closing';
+    ret = this._client._sshstream.channelClose(outgoing.id);
+  }
+
+  return ret;
+};
+
+Channel.prototype._read = function(n) {
+  if (this._waitChanDrain) {
+    this._waitChanDrain = false;
+    if (this.incoming.window <= WINDOW_THRESHOLD)
+      windowAdjust(this);
+  }
+};
+
+Channel.prototype._write = function(data, encoding, cb) {
+  var sshstream = this._client._sshstream;
+  var outgoing = this.outgoing;
+  var packetSize = outgoing.packetSize;
+  var id = outgoing.id;
+  var window = outgoing.window;
+  var len = data.length;
+  var p = 0;
+  var ret;
+  var buf;
+  var sliceLen;
+
+  if (outgoing.state !== 'open')
+    return;
+
+  while (len - p > 0 && window > 0) {
+    sliceLen = len - p;
+    if (sliceLen > window)
+      sliceLen = window;
+    if (sliceLen > packetSize)
+      sliceLen = packetSize;
+
+    ret = sshstream.channelData(id, data.slice(p, p + sliceLen));
+
+    p += sliceLen;
+    window -= sliceLen;
+
+    if (!ret) {
+      this._waitClientDrain = true;
+      this._chunk = undefined;
+      this._chunkcb = cb;
+      break;
+    }
+  }
+
+  outgoing.window = window;
+
+  if (len - p > 0) {
+    if (window === 0)
+      this._waitWindow = true;
+    if (p > 0) {
+      // partial
+      buf = new Buffer(len - p);
+      data.copy(buf, 0, p);
+      this._chunk = buf;
+    } else
+      this._chunk = data;
+    this._chunkcb = cb;
+    return;
+  }
+
+  if (!this._waitClientDrain)
+    cb();
+};
+
+Channel.prototype.destroy = function() {
+  this.end();
+};
+
+// session type-specific methods
+Channel.prototype.setWindow = function(rows, cols, height, width) {
+  if (this.server)
+    throw new Error('Client-only method called in server mode');
+
+  if (this.type === 'session'
+      && (this.subtype === 'shell' || this.subtype === 'exec')
+      && this.writable
+      && this.outgoing.state === 'open') {
+    return this._client._sshstream.windowChange(this.outgoing.id,
+                                                rows,
+                                                cols,
+                                                height,
+                                                width);
+  }
+
+  return true;
+};
+Channel.prototype.signal = function(signalName) {
+  if (this.server)
+    throw new Error('Client-only method called in server mode');
+
+  if (this.type === 'session'
+      && this.writable
+      && this.outgoing.state === 'open')
+    return this._client._sshstream.signal(this.outgoing.id, signalName);
+
+  return true;
+};
+Channel.prototype.exit = function(name, coreDumped, msg) {
+  if (!this.server)
+    throw new Error('Server-only method called in client mode');
+
+  if (this.type === 'session'
+      && this.writable
+      && this.outgoing.state === 'open') {
+    if (typeof name === 'number')
+      return this._client._sshstream.exitStatus(this.outgoing.id, name);
+    else {
+      return this._client._sshstream.exitSignal(this.outgoing.id,
+                                                name,
+                                                coreDumped,
+                                                msg);
+    }
+  }
+
+  return true;
+};
+
+Channel.MAX_WINDOW = MAX_WINDOW;
+Channel.PACKET_SIZE = PACKET_SIZE;
+
+function windowAdjust(self) {
+  if (self.outgoing.state !== 'open')
+    return true;
+  var amt = MAX_WINDOW - self.incoming.window;
+  if (amt <= 0)
+    return true;
+  self.incoming.window += amt;
+  return self._client._sshstream.channelWindowAdjust(self.outgoing.id, amt);
+}
+
+function ServerStderr(channel) {
+  WritableStream.call(this, { highWaterMark: MAX_WINDOW });
+  this._channel = channel;
+}
+inherits(ServerStderr, WritableStream);
+
+ServerStderr.prototype._write = function(data, encoding, cb) {
+  var channel = this._channel;
+  var sshstream = channel._client._sshstream;
+  var outgoing = channel.outgoing;
+  var packetSize = outgoing.packetSize;
+  var id = outgoing.id;
+  var window = outgoing.window;
+  var len = data.length;
+  var p = 0;
+  var ret;
+  var buf;
+  var sliceLen;
+
+  if (channel.outgoing.state !== 'open')
+    return;
+
+  while (len - p > 0 && window > 0) {
+    sliceLen = len - p;
+    if (sliceLen > window)
+      sliceLen = window;
+    if (sliceLen > packetSize)
+      sliceLen = packetSize;
+
+    ret = sshstream.channelExtData(id, data.slice(p, p + sliceLen), STDERR);
+
+    p += sliceLen;
+    window -= sliceLen;
+
+    if (!ret) {
+      channel._waitClientDrain = true;
+      channel._chunkErr = undefined;
+      channel._chunkcbErr = cb;
+      break;
+    }
+  }
+
+  outgoing.window = window;
+
+  if (len - p > 0) {
+    if (window === 0)
+      channel._waitWindow = true;
+    if (p > 0) {
+      // partial
+      buf = new Buffer(len - p);
+      data.copy(buf, 0, p);
+      channel._chunkErr = buf;
+    } else
+      channel._chunkErr = data;
+    channel._chunkcbErr = cb;
+    return;
+  }
+
+  if (!channel._waitClientDrain)
+    cb();
+};
+
+module.exports = Channel;