aboutsummaryrefslogtreecommitdiff
path: root/nxcomp/src/Channel.h
blob: 079007e9618bb598718d27204f93f7bc1a35727f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
/**************************************************************************/
/*                                                                        */
/* Copyright (c) 2001, 2011 NoMachine (http://www.nomachine.com)          */
/* Copyright (c) 2008-2014 Oleksandr Shneyder <o.shneyder@phoca-gmbh.de>  */
/* Copyright (c) 2014-2016 Ulrich Sibiller <uli42@gmx.de>                 */
/* Copyright (c) 2014-2016 Mihai Moldovan <ionic@ionic.de>                */
/* Copyright (c) 2011-2016 Mike Gabriel <mike.gabriel@das-netzwerkteam.de>*/
/* Copyright (c) 2015-2016 Qindel Group (http://www.qindel.com)           */
/*                                                                        */
/* NXCOMP, NX protocol compression and NX extensions to this software     */
/* are copyright of the aforementioned persons and companies.             */
/*                                                                        */
/* Redistribution and use of the present software is allowed according    */
/* to terms specified in the file LICENSE.nxcomp which comes in the       */
/* source distribution.                                                   */
/*                                                                        */
/* All rights reserved.                                                   */
/*                                                                        */
/* NOTE: This software has received contributions from various other      */
/* contributors, only the core maintainers and supporters are listed as   */
/* copyright holders. Please contact us, if you feel you should be listed */
/* as copyright holder, as well.                                          */
/*                                                                        */
/**************************************************************************/

#ifndef Channel_H
#define Channel_H

#include "Transport.h"

#include "WriteBuffer.h"

#include "OpcodeStore.h"

#include "ClientStore.h"
#include "ServerStore.h"

#include "ClientCache.h"
#include "ServerCache.h"

#include "EncodeBuffer.h"
#include "DecodeBuffer.h"

//
// Forward declaration of referenced classes.
//

class List;

class StaticCompressor;

//
// Set the verbosity level.
//

#define PANIC
#define WARNING
#undef  TEST
#undef  DEBUG

//
// Define this to log a line when a channel
// is created or destroyed.
//

#undef  REFERENCES

//
// Type of traffic carried by channel.
//

typedef enum
{
  channel_none = -1,
  channel_x11,
  channel_cups,
  channel_smb,
  channel_media,
  channel_http,
  channel_font,
  channel_slave,
  channel_last_tag

} T_channel_type;

//
// Type of notification event to be sent
// by proxy to the X channel.
//

typedef enum
{
  notify_no_split,
  notify_start_split,
  notify_commit_split,
  notify_end_split,
  notify_empty_split,

} T_notification_type;

class Channel
{
  public:

  //
  // Maximum number of X connections supported.
  //

  static const int CONNECTIONS_LIMIT = 256;

  Channel(Transport *transport, StaticCompressor *compressor);

  virtual ~Channel();

  //
  // Read any X message available on the X
  // connection and encode it to the encode
  // buffer.
  //

  virtual int handleRead(EncodeBuffer &encodeBuffer, const unsigned char *message,
                             unsigned int length) = 0;

  //
  // Decode any X message encoded in the
  // proxy message and write it to the X
  // connection.
  //

  virtual int handleWrite(const unsigned char *message, unsigned int length) = 0;

  //
  // Other methods to be implemented in
  // client, server and generic channel
  // classes.
  //

  virtual int handleSplit(EncodeBuffer &encodeBuffer, MessageStore *store,
                              T_store_action action, int position, const unsigned char opcode,
                                  const unsigned char *buffer, const unsigned int size) = 0;

  virtual int handleSplit(DecodeBuffer &decodeBuffer, MessageStore *store,
                              T_store_action action, int position, unsigned char &opcode,
                                  unsigned char *&buffer, unsigned int &size) = 0;

  virtual int handleSplit(EncodeBuffer &encodeBuffer) = 0;

  virtual int handleSplit(DecodeBuffer &decodeBuffer) = 0;

  virtual int handleSplitEvent(EncodeBuffer &encodeBuffer, Split *split) = 0;

  virtual int handleSplitEvent(DecodeBuffer &decodeBuffer) = 0;

  virtual int handleMotion(EncodeBuffer &encodeBuffer) = 0;

  virtual int handleCompletion(EncodeBuffer &encodeBuffer) = 0;

  virtual int handleConfiguration() = 0;

  virtual int handleFinish() = 0;

  //
  // Interleave reads of the available
  // events while writing data to the
  // channel socket.
  //

  virtual int handleAsyncEvents() = 0;

  //
  // Handle the channel tear down.
  //

  int handleClosing()
  {
    closing_ = 1;

    return 1;
  }

  int handleDrop()
  {
    drop_ = 1;

    return 1;
  }

  //
  // Try to read more data from the socket. In
  // the meanwhile flush any enqueued data if
  // the channel is blocked. Return as soon as
  // more data has been read or the timeout has
  // been exceeded.
  //

  int handleWait(int timeout);

  //
  // Drain the output buffer while handling the
  // data that may become readable.
  //

  int handleDrain(int timeout, int limit);

  //
  // Flush any remaining data in the transport
  // buffer.
  //

  int handleFlush();

  //
  // Called when the loop has replaced or
  // closed a previous alert.
  //

  void handleResetAlert();

  //
  // Initialize all the static members.
  //

  static int setReferences();

  //
  // Set pointer to object mapping opcodes
  // of NX specific messages.
  //

  int setOpcodes(OpcodeStore *opcodeStore);

  //
  // Update pointers to message stores in
  // channels.
  //

  int setStores(ClientStore *clientStore, ServerStore *serverStore);

  //
  // The same for channels caches.
  //

  int setCaches(ClientCache *clientCache, ServerCache *serverCache);

  //
  // Set the port used for tunneling of the
  // font server connections.
  //

  void setPorts(int fontPort)
  {
    fontPort_ = fontPort;
  }

  //
  // Check if there are pending split
  // to send to the remote side.
  //

  virtual int needSplit() const = 0;

  //
  // Check if there are motion events
  // to flush.
  //

  virtual int needMotion() const = 0;

  //
  // Return the type of traffic carried
  // by this channel.
  //

  virtual T_channel_type getType() const = 0;

  //
  // Check if the channel has been marked
  // as closing down.
  //

  int getFinish() const
  {
    return finish_;
  }

  int getClosing()
  {
    return closing_;
  }

  int getDrop()
  {
    return drop_;
  }

  int getCongestion()
  {
    return congestion_;
  }

  protected:

  int handleFlush(T_flush type)
  {
    //
    // We could write the data immediately if there
    // is already something queued to the low level
    // TCP buffers.
    //
    // if (... || transport_ -> queued() > 0)
    // {
    //   ...
    // }
    //

    if (writeBuffer_.getScratchLength() > 0 ||
          (type == flush_if_any && writeBuffer_.getLength() > 0) ||
              writeBuffer_.getLength() >= (unsigned int)
                  control -> TransportFlushBufferSize)
    {
      return handleFlush(type, writeBuffer_.getLength(),
                             writeBuffer_.getScratchLength());
    }

    return 0;
  }

  //
  // Actually flush the data to the
  // channel descriptor.
  //

  int handleFlush(T_flush type, int bufferLength, int scratchLength);

  //
  // Handle the congestion changes.
  //

  int handleCongestion();

  //
  // Encode and decode X messages.
  //

  int handleEncode(EncodeBuffer &encodeBuffer, ChannelCache *channelCache,
                       MessageStore *store, const unsigned char opcode,
                           const unsigned char *buffer, const unsigned int size);

  int handleDecode(DecodeBuffer &decodeBuffer, ChannelCache *channelCache,
                       MessageStore *store, unsigned char &opcode,
                           unsigned char *&buffer, unsigned int &size);

  //
  // Encode the message based on its
  // message store.
  //

  int handleEncodeCached(EncodeBuffer &encodeBuffer, ChannelCache *channelCache,
                             MessageStore *store,  const unsigned char *buffer,
                                 const unsigned int size);

  int handleDecodeCached(DecodeBuffer &decodeBuffer, ChannelCache *channelCache,
                             MessageStore *store, unsigned char *&buffer,
                                 unsigned int &size);

  int handleEncodeIdentity(EncodeBuffer &encodeBuffer, ChannelCache *channelCache,
                               MessageStore *store, const unsigned char *buffer,
                                   const unsigned int size, int _bigEndian)
  {
    return (store -> encodeIdentity(encodeBuffer, buffer, size,
                                        _bigEndian, channelCache));
  }

  int handleDecodeIdentity(DecodeBuffer &decodeBuffer, ChannelCache *channelCache,
                               MessageStore *store, unsigned char *&buffer,
                                   unsigned int &size, int _bigEndian,
                                       WriteBuffer *writeBuffer)
  {
    return (store -> decodeIdentity(decodeBuffer, buffer, size, _bigEndian,
                                        writeBuffer, channelCache));
  }

  //
  // Other utility functions used by
  // the encoding and decoding methods.
  //

  void handleCopy(EncodeBuffer &encodeBuffer, const unsigned char opcode,
                      const unsigned int offset, const unsigned char *buffer,
                          const unsigned int size)
  {
    if (size > offset)
    {
      encodeBuffer.encodeMemory(buffer + offset, size - offset);
    }
  }

  void handleCopy(DecodeBuffer &decodeBuffer, const unsigned char opcode,
                      const unsigned int offset, unsigned char *buffer,
                          const unsigned int size)
  {
    if (size > offset)
    {
      memcpy(buffer + offset, decodeBuffer.decodeMemory(size - offset), size - offset);
    }
  }

  void handleUpdate(MessageStore *store, const unsigned int dataSize,
                        const unsigned int compressedDataSize)
  {
    if (store -> lastAction == IS_ADDED)
    {
      handleUpdateAdded(store, dataSize, compressedDataSize);
    }
  }

  void handleSave(MessageStore *store, unsigned char *buffer, unsigned int size,
                      const unsigned char *compressedData = NULL,
                          const unsigned int compressedDataSize = 0)
  {
    if (store -> lastAction == IS_ADDED)
    {
      handleSaveAdded(store, 0, buffer, size, compressedData, compressedDataSize);
    }
  }

  void handleSaveSplit(MessageStore *store, unsigned char *buffer,
                          unsigned int size)
  {
    if (store -> lastAction == IS_ADDED)
    {
      return handleSaveAdded(store, 1, buffer, size, 0, 0);
    }
  }

  void handleUpdateAdded(MessageStore *store, const unsigned int dataSize,
                             const unsigned int compressedDataSize);

  void handleSaveAdded(MessageStore *store, int split, unsigned char *buffer,
                           unsigned int size, const unsigned char *compressedData,
                               const unsigned int compressedDataSize);

  //
  // Compress the data part of a message
  // using ZLIB or another compressor
  // and send it over the network.
  //

  int handleCompress(EncodeBuffer &encodeBuffer, const unsigned char opcode,
                         const unsigned int offset, const unsigned char *buffer,
                             const unsigned int size, unsigned char *&compressedData,
                                 unsigned int &compressedDataSize);

  int handleDecompress(DecodeBuffer &decodeBuffer, const unsigned char opcode,
                           const unsigned int offset, unsigned char *buffer,
                               const unsigned int size, const unsigned char *&compressedData,
                                   unsigned int &compressedDataSize);

  //
  // Send an X_NoOperation to the X server.
  // The second version also removes any
  // previous data in the write buffer.
  //

  int handleNullRequest(unsigned char &opcode, unsigned char *&buffer,
                            unsigned int &size);

  int handleCleanAndNullRequest(unsigned char &opcode, unsigned char *&buffer,
                                    unsigned int &size);

  //
  // X11 channels are considered to be in
  // congestion state when there was a
  // blocking write and, since then, the
  // local end didn't consume all the data.
  //

  virtual int isCongested()
  {
    return (transport_ -> getType() !=
                transport_agent && transport_ -> length() >
                    control -> TransportFlushBufferSize);
  }

  virtual int isReliable()
  {
    return 1;
  }

  //
  // Determine how to handle allocation
  // of new messages in the message
  // stores.
  //

  int mustCleanStore(MessageStore *store)
  {
    return (store -> getRemoteTotalStorageSize() > control ->
                RemoteTotalStorageSize || store -> getLocalTotalStorageSize() >
                    control -> LocalTotalStorageSize || (store -> getRemoteStorageSize() >
                        (control -> RemoteTotalStorageSize / 100 * store ->
                            cacheThreshold)) || (store -> getLocalStorageSize() >
                                (control -> LocalTotalStorageSize / 100 * store ->
                                    cacheThreshold)));
  }

  int canCleanStore(MessageStore *store)
  {
    return ((store -> getSize() > 0 && (store -> getRemoteStorageSize() >
                (control -> RemoteTotalStorageSize / 100 * store ->
                    cacheLowerThreshold))) || (store -> getLocalStorageSize() >
                        (control -> LocalTotalStorageSize / 100 *  store ->
                            cacheLowerThreshold)));
  }

  protected:

  //
  // Set up the split stores.
  //

  void handleSplitStoreError(int resource) __attribute__((noreturn));

  void handleSplitStoreAlloc(List *list, int resource);
  void handleSplitStoreRemove(List *list, int resource);

  Split *handleSplitCommitRemove(int request, int resource, int position);

  void validateSize(const char *name, int input, int output,
                        int offset, int size)
  {
    if (size < offset || size > control -> MaximumMessageSize ||
           size != (int) RoundUp4(input) + offset ||
               output > control -> MaximumMessageSize)
    {
      *logofs << "Channel: PANIC! Invalid size " << size
              << " for " << name << " output with data "
              << input << "/" << output << "/" << offset
              << "/" << size << ".\n" << logofs_flush;

      cerr << "Error" << ": Invalid size " << size
           << " for " << name << " output.\n";

      HandleAbort();
    }
  }

  //
  // Is the X client big endian?
  //

  int bigEndian() const
  {
    return bigEndian_;
  }

  int bigEndian_;

  //
  // Other X server's features
  // saved at session startup.
  //

  unsigned int imageByteOrder_;
  unsigned int bitmapBitOrder_;
  unsigned int scanlineUnit_;
  unsigned int scanlinePad_;

  int firstRequest_;
  int firstReply_;

  //
  // Use this class for IO operations.
  //

  Transport *transport_;

  //
  // The static compressor is created by the
  // proxy and shared among channels.
  //

  StaticCompressor *compressor_;

  //
  // Map NX operations to opcodes. Propagated
  // by proxy to all channels on the same X
  // server.
  //

  OpcodeStore *opcodeStore_;

  //
  // Also stores are shared between channels.
  //

  ClientStore *clientStore_;
  ServerStore *serverStore_;

  //
  // Caches are specific for each channel.
  //

  ClientCache *clientCache_;
  ServerCache *serverCache_;

  //
  // Data going to X connection.
  //

  WriteBuffer writeBuffer_;

  //
  // Other data members.
  //

  int fd_;

  int finish_;
  int closing_;
  int drop_;
  int congestion_;
  int priority_;

  int alert_;

  //
  // It will be set to the descriptor of the
  // first X channel that is successfully con-
  // nected and will print an info message on
  // standard error.
  //

  static int firstClient_;

  //
  // Port used for font server connections.
  //

  static int fontPort_;

  //
  // Track which cache operations have been
  // enabled by the agent.
  //

  int enableCache_;
  int enableSplit_;
  int enableSave_;
  int enableLoad_;

  //
  // Keep track of object creation and
  // deletion.
  //

  #ifdef REFERENCES

  static int references_;

  #endif
};

#endif /* Channel_H */