summaryrefslogtreecommitdiff
path: root/common/xyzModem.c
blob: 6ded958e8907663a28709ac850091ad2ff7110cc (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
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
/*
 *==========================================================================
 *
 *      xyzModem.c
 *
 *      RedBoot stream handler for xyzModem protocol
 *
 *==========================================================================
 * SPDX-License-Identifier:	eCos-2.0
 *==========================================================================
 *#####DESCRIPTIONBEGIN####
 *
 * Author(s):    gthomas
 * Contributors: gthomas, tsmith, Yoshinori Sato
 * Date:         2000-07-14
 * Purpose:
 * Description:
 *
 * This code is part of RedBoot (tm).
 *
 *####DESCRIPTIONEND####
 *
 *==========================================================================
 */
#include <common.h>
#include <xyzModem.h>
#include <stdarg.h>
#include <crc.h>

/* Assumption - run xyzModem protocol over the console port */

/* Values magic to the protocol */
#define SOH 0x01
#define STX 0x02
#define EOT 0x04
#define ACK 0x06
#define BSP 0x08
#define NAK 0x15
#define CAN 0x18
#define EOF 0x1A		/* ^Z for DOS officionados */

/* Data & state local to the protocol */
static struct
{
  int *__chan;
  unsigned char pkt[1024], *bufp;
  unsigned char blk, cblk, crc1, crc2;
  unsigned char next_blk;	/* Expected block */
  int len, mode, total_retries;
  int total_SOH, total_STX, total_CAN;
  bool crc_mode, at_eof, tx_ack;
  unsigned long file_length, read_length;
} xyz;

#define xyzModem_CHAR_TIMEOUT            2000	/* 2 seconds */
#define xyzModem_MAX_RETRIES             20
#define xyzModem_MAX_RETRIES_WITH_CRC    10
#define xyzModem_CAN_COUNT                3	/* Wait for 3 CAN before quitting */


typedef int cyg_int32;
static int
CYGACC_COMM_IF_GETC_TIMEOUT (char chan, char *c)
{

  ulong now = get_timer(0);
  while (!tstc ())
    {
      if (get_timer(now) > xyzModem_CHAR_TIMEOUT)
        break;
    }
  if (tstc ())
    {
      *c = getc ();
      return 1;
    }
  return 0;
}

static void
CYGACC_COMM_IF_PUTC (char x, char y)
{
  putc (y);
}

/* Validate a hex character */
__inline__ static bool
_is_hex (char c)
{
  return (((c >= '0') && (c <= '9')) ||
	  ((c >= 'A') && (c <= 'F')) || ((c >= 'a') && (c <= 'f')));
}

/* Convert a single hex nibble */
__inline__ static int
_from_hex (char c)
{
  int ret = 0;

  if ((c >= '0') && (c <= '9'))
    {
      ret = (c - '0');
    }
  else if ((c >= 'a') && (c <= 'f'))
    {
      ret = (c - 'a' + 0x0a);
    }
  else if ((c >= 'A') && (c <= 'F'))
    {
      ret = (c - 'A' + 0x0A);
    }
  return ret;
}

/* Convert a character to lower case */
__inline__ static char
_tolower (char c)
{
  if ((c >= 'A') && (c <= 'Z'))
    {
      c = (c - 'A') + 'a';
    }
  return c;
}

/* Parse (scan) a number */
static bool
parse_num (char *s, unsigned long *val, char **es, char *delim)
{
  bool first = true;
  int radix = 10;
  char c;
  unsigned long result = 0;
  int digit;

  while (*s == ' ')
    s++;
  while (*s)
    {
      if (first && (s[0] == '0') && (_tolower (s[1]) == 'x'))
	{
	  radix = 16;
	  s += 2;
	}
      first = false;
      c = *s++;
      if (_is_hex (c) && ((digit = _from_hex (c)) < radix))
	{
	  /* Valid digit */
	  result = (result * radix) + digit;
	}
      else
	{
	  if (delim != (char *) 0)
	    {
	      /* See if this character is one of the delimiters */
	      char *dp = delim;
	      while (*dp && (c != *dp))
		dp++;
	      if (*dp)
		break;		/* Found a good delimiter */
	    }
	  return false;		/* Malformatted number */
	}
    }
  *val = result;
  if (es != (char **) 0)
    {
      *es = s;
    }
  return true;
}


#ifdef DEBUG
/*
 * Note: this debug setup works by storing the strings in a fixed buffer
 */
#define FINAL
#ifdef FINAL
static char *zm_out = (char *) 0x00380000;
static char *zm_out_start = (char *) 0x00380000;
#else
static char zm_buf[8192];
static char *zm_out = zm_buf;
static char *zm_out_start = zm_buf;

#endif
static int
zm_dprintf (char *fmt, ...)
{
  int len;
  va_list args;

  va_start (args, fmt);
  len = diag_vsprintf (zm_out, fmt, args);
  zm_out += len;
  return len;
}

static void
zm_flush (void)
{
  zm_out = zm_out_start;
}

static void
zm_dump_buf (void *buf, int len)
{

}

static unsigned char zm_buf[2048];
static unsigned char *zm_bp;

static void
zm_new (void)
{
  zm_bp = zm_buf;
}

static void
zm_save (unsigned char c)
{
  *zm_bp++ = c;
}

static void
zm_dump (int line)
{
  zm_dprintf ("Packet at line: %d\n", line);
  zm_dump_buf (zm_buf, zm_bp - zm_buf);
}

#define ZM_DEBUG(x) x
#else
#define ZM_DEBUG(x)
#endif

/* Wait for the line to go idle */
static void
xyzModem_flush (void)
{
  int res;
  char c;
  while (true)
    {
      res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, &c);
      if (!res)
	return;
    }
}

static int
xyzModem_get_hdr (void)
{
  char c;
  int res;
  bool hdr_found = false;
  int i, can_total, hdr_chars;
  unsigned short cksum;

  ZM_DEBUG (zm_new ());
  /* Find the start of a header */
  can_total = 0;
  hdr_chars = 0;

  if (xyz.tx_ack)
    {
      CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
      xyz.tx_ack = false;
    }
  while (!hdr_found)
    {
      res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, &c);
      ZM_DEBUG (zm_save (c));
      if (res)
	{
	  hdr_chars++;
	  switch (c)
	    {
	    case SOH:
	      xyz.total_SOH++;
	    case STX:
	      if (c == STX)
		xyz.total_STX++;
	      hdr_found = true;
	      break;
	    case CAN:
	      xyz.total_CAN++;
	      ZM_DEBUG (zm_dump (__LINE__));
	      if (++can_total == xyzModem_CAN_COUNT)
		{
		  return xyzModem_cancel;
		}
	      else
		{
		  /* Wait for multiple CAN to avoid early quits */
		  break;
		}
	    case EOT:
	      /* EOT only supported if no noise */
	      if (hdr_chars == 1)
		{
		  CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
		  ZM_DEBUG (zm_dprintf ("ACK on EOT #%d\n", __LINE__));
		  ZM_DEBUG (zm_dump (__LINE__));
		  return xyzModem_eof;
		}
	    default:
	      /* Ignore, waiting for start of header */
	      ;
	    }
	}
      else
	{
	  /* Data stream timed out */
	  xyzModem_flush ();	/* Toss any current input */
	  ZM_DEBUG (zm_dump (__LINE__));
	  CYGACC_CALL_IF_DELAY_US ((cyg_int32) 250000);
	  return xyzModem_timeout;
	}
    }

  /* Header found, now read the data */
  res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, (char *) &xyz.blk);
  ZM_DEBUG (zm_save (xyz.blk));
  if (!res)
    {
      ZM_DEBUG (zm_dump (__LINE__));
      return xyzModem_timeout;
    }
  res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, (char *) &xyz.cblk);
  ZM_DEBUG (zm_save (xyz.cblk));
  if (!res)
    {
      ZM_DEBUG (zm_dump (__LINE__));
      return xyzModem_timeout;
    }
  xyz.len = (c == SOH) ? 128 : 1024;
  xyz.bufp = xyz.pkt;
  for (i = 0; i < xyz.len; i++)
    {
      res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, &c);
      ZM_DEBUG (zm_save (c));
      if (res)
	{
	  xyz.pkt[i] = c;
	}
      else
	{
	  ZM_DEBUG (zm_dump (__LINE__));
	  return xyzModem_timeout;
	}
    }
  res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, (char *) &xyz.crc1);
  ZM_DEBUG (zm_save (xyz.crc1));
  if (!res)
    {
      ZM_DEBUG (zm_dump (__LINE__));
      return xyzModem_timeout;
    }
  if (xyz.crc_mode)
    {
      res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, (char *) &xyz.crc2);
      ZM_DEBUG (zm_save (xyz.crc2));
      if (!res)
	{
	  ZM_DEBUG (zm_dump (__LINE__));
	  return xyzModem_timeout;
	}
    }
  ZM_DEBUG (zm_dump (__LINE__));
  /* Validate the message */
  if ((xyz.blk ^ xyz.cblk) != (unsigned char) 0xFF)
    {
      ZM_DEBUG (zm_dprintf
		("Framing error - blk: %x/%x/%x\n", xyz.blk, xyz.cblk,
		 (xyz.blk ^ xyz.cblk)));
      ZM_DEBUG (zm_dump_buf (xyz.pkt, xyz.len));
      xyzModem_flush ();
      return xyzModem_frame;
    }
  /* Verify checksum/CRC */
  if (xyz.crc_mode)
    {
      cksum = crc16_ccitt(0, xyz.pkt, xyz.len);
      if (cksum != ((xyz.crc1 << 8) | xyz.crc2))
	{
	  ZM_DEBUG (zm_dprintf ("CRC error - recvd: %02x%02x, computed: %x\n",
				xyz.crc1, xyz.crc2, cksum & 0xFFFF));
	  return xyzModem_cksum;
	}
    }
  else
    {
      cksum = 0;
      for (i = 0; i < xyz.len; i++)
	{
	  cksum += xyz.pkt[i];
	}
      if (xyz.crc1 != (cksum & 0xFF))
	{
	  ZM_DEBUG (zm_dprintf
		    ("Checksum error - recvd: %x, computed: %x\n", xyz.crc1,
		     cksum & 0xFF));
	  return xyzModem_cksum;
	}
    }
  /* If we get here, the message passes [structural] muster */
  return 0;
}

int
xyzModem_stream_open (connection_info_t * info, int *err)
{
  int stat = 0;
  int retries = xyzModem_MAX_RETRIES;
  int crc_retries = xyzModem_MAX_RETRIES_WITH_CRC;

/*    ZM_DEBUG(zm_out = zm_out_start); */
#ifdef xyzModem_zmodem
  if (info->mode == xyzModem_zmodem)
    {
      *err = xyzModem_noZmodem;
      return -1;
    }
#endif

/* TODO: CHECK ! */
  int dummy = 0;
  xyz.__chan = &dummy;
  xyz.len = 0;
  xyz.crc_mode = true;
  xyz.at_eof = false;
  xyz.tx_ack = false;
  xyz.mode = info->mode;
  xyz.total_retries = 0;
  xyz.total_SOH = 0;
  xyz.total_STX = 0;
  xyz.total_CAN = 0;
  xyz.read_length = 0;
  xyz.file_length = 0;

  CYGACC_COMM_IF_PUTC (*xyz.__chan, (xyz.crc_mode ? 'C' : NAK));

  if (xyz.mode == xyzModem_xmodem)
    {
      /* X-modem doesn't have an information header - exit here */
      xyz.next_blk = 1;
      return 0;
    }

  while (retries-- > 0)
    {
      stat = xyzModem_get_hdr ();
      if (stat == 0)
	{
	  /* Y-modem file information header */
	  if (xyz.blk == 0)
	    {
	      /* skip filename */
	      while (*xyz.bufp++);
	      /* get the length */
	      parse_num ((char *) xyz.bufp, &xyz.file_length, NULL, " ");
	      /* The rest of the file name data block quietly discarded */
	      xyz.tx_ack = true;
	    }
	  xyz.next_blk = 1;
	  xyz.len = 0;
	  return 0;
	}
      else if (stat == xyzModem_timeout)
	{
	  if (--crc_retries <= 0)
	    xyz.crc_mode = false;
	  CYGACC_CALL_IF_DELAY_US (5 * 100000);	/* Extra delay for startup */
	  CYGACC_COMM_IF_PUTC (*xyz.__chan, (xyz.crc_mode ? 'C' : NAK));
	  xyz.total_retries++;
	  ZM_DEBUG (zm_dprintf ("NAK (%d)\n", __LINE__));
	}
      if (stat == xyzModem_cancel)
	{
	  break;
	}
    }
  *err = stat;
  ZM_DEBUG (zm_flush ());
  return -1;
}

int
xyzModem_stream_read (char *buf, int size, int *err)
{
  int stat, total, len;
  int retries;

  total = 0;
  stat = xyzModem_cancel;
  /* Try and get 'size' bytes into the buffer */
  while (!xyz.at_eof && (size > 0))
    {
      if (xyz.len == 0)
	{
	  retries = xyzModem_MAX_RETRIES;
	  while (retries-- > 0)
	    {
	      stat = xyzModem_get_hdr ();
	      if (stat == 0)
		{
		  if (xyz.blk == xyz.next_blk)
		    {
		      xyz.tx_ack = true;
		      ZM_DEBUG (zm_dprintf
				("ACK block %d (%d)\n", xyz.blk, __LINE__));
		      xyz.next_blk = (xyz.next_blk + 1) & 0xFF;

		      if (xyz.mode == xyzModem_xmodem || xyz.file_length == 0)
			{
			  /* Data blocks can be padded with ^Z (EOF) characters */
			  /* This code tries to detect and remove them */
			  if ((xyz.bufp[xyz.len - 1] == EOF) &&
			      (xyz.bufp[xyz.len - 2] == EOF) &&
			      (xyz.bufp[xyz.len - 3] == EOF))
			    {
			      while (xyz.len
				     && (xyz.bufp[xyz.len - 1] == EOF))
				{
				  xyz.len--;
				}
			    }
			}

		      /*
		       * See if accumulated length exceeds that of the file.
		       * If so, reduce size (i.e., cut out pad bytes)
		       * Only do this for Y-modem (and Z-modem should it ever
		       * be supported since it can fall back to Y-modem mode).
		       */
		      if (xyz.mode != xyzModem_xmodem && 0 != xyz.file_length)
			{
			  xyz.read_length += xyz.len;
			  if (xyz.read_length > xyz.file_length)
			    {
			      xyz.len -= (xyz.read_length - xyz.file_length);
			    }
			}
		      break;
		    }
		  else if (xyz.blk == ((xyz.next_blk - 1) & 0xFF))
		    {
		      /* Just re-ACK this so sender will get on with it */
		      CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
		      continue;	/* Need new header */
		    }
		  else
		    {
		      stat = xyzModem_sequence;
		    }
		}
	      if (stat == xyzModem_cancel)
		{
		  break;
		}
	      if (stat == xyzModem_eof)
		{
		  CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
		  ZM_DEBUG (zm_dprintf ("ACK (%d)\n", __LINE__));
		  if (xyz.mode == xyzModem_ymodem)
		    {
		      CYGACC_COMM_IF_PUTC (*xyz.__chan,
					   (xyz.crc_mode ? 'C' : NAK));
		      xyz.total_retries++;
		      ZM_DEBUG (zm_dprintf ("Reading Final Header\n"));
		      stat = xyzModem_get_hdr ();
		      CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
		      ZM_DEBUG (zm_dprintf ("FINAL ACK (%d)\n", __LINE__));
		    }
		  xyz.at_eof = true;
		  break;
		}
	      CYGACC_COMM_IF_PUTC (*xyz.__chan, (xyz.crc_mode ? 'C' : NAK));
	      xyz.total_retries++;
	      ZM_DEBUG (zm_dprintf ("NAK (%d)\n", __LINE__));
	    }
	  if (stat < 0)
	    {
	      *err = stat;
	      xyz.len = -1;
	      return total;
	    }
	}
      /* Don't "read" data from the EOF protocol package */
      if (!xyz.at_eof)
	{
	  len = xyz.len;
	  if (size < len)
	    len = size;
	  memcpy (buf, xyz.bufp, len);
	  size -= len;
	  buf += len;
	  total += len;
	  xyz.len -= len;
	  xyz.bufp += len;
	}
    }
  return total;
}

void
xyzModem_stream_close (int *err)
{
  diag_printf
    ("xyzModem - %s mode, %d(SOH)/%d(STX)/%d(CAN) packets, %d retries\n",
     xyz.crc_mode ? "CRC" : "Cksum", xyz.total_SOH, xyz.total_STX,
     xyz.total_CAN, xyz.total_retries);
  ZM_DEBUG (zm_flush ());
}

/* Need to be able to clean out the input buffer, so have to take the */
/* getc */
void
xyzModem_stream_terminate (bool abort, int (*getc) (void))
{
  int c;

  if (abort)
    {
      ZM_DEBUG (zm_dprintf ("!!!! TRANSFER ABORT !!!!\n"));
      switch (xyz.mode)
	{
	case xyzModem_xmodem:
	case xyzModem_ymodem:
	  /* The X/YMODEM Spec seems to suggest that multiple CAN followed by an equal */
	  /* number of Backspaces is a friendly way to get the other end to abort. */
	  CYGACC_COMM_IF_PUTC (*xyz.__chan, CAN);
	  CYGACC_COMM_IF_PUTC (*xyz.__chan, CAN);
	  CYGACC_COMM_IF_PUTC (*xyz.__chan, CAN);
	  CYGACC_COMM_IF_PUTC (*xyz.__chan, CAN);
	  CYGACC_COMM_IF_PUTC (*xyz.__chan, BSP);
	  CYGACC_COMM_IF_PUTC (*xyz.__chan, BSP);
	  CYGACC_COMM_IF_PUTC (*xyz.__chan, BSP);
	  CYGACC_COMM_IF_PUTC (*xyz.__chan, BSP);
	  /* Now consume the rest of what's waiting on the line. */
	  ZM_DEBUG (zm_dprintf ("Flushing serial line.\n"));
	  xyzModem_flush ();
	  xyz.at_eof = true;
	  break;
#ifdef xyzModem_zmodem
	case xyzModem_zmodem:
	  /* Might support it some day I suppose. */
#endif
	  break;
	}
    }
  else
    {
      ZM_DEBUG (zm_dprintf ("Engaging cleanup mode...\n"));
      /*
       * Consume any trailing crap left in the inbuffer from
       * previous received blocks. Since very few files are an exact multiple
       * of the transfer block size, there will almost always be some gunk here.
       * If we don't eat it now, RedBoot will think the user typed it.
       */
      ZM_DEBUG (zm_dprintf ("Trailing gunk:\n"));
      while ((c = (*getc) ()) > -1)
        ;
      ZM_DEBUG (zm_dprintf ("\n"));
      /*
       * Make a small delay to give terminal programs like minicom
       * time to get control again after their file transfer program
       * exits.
       */
      CYGACC_CALL_IF_DELAY_US ((cyg_int32) 250000);
    }
}

char *
xyzModem_error (int err)
{
  switch (err)
    {
    case xyzModem_access:
      return "Can't access file";
      break;
    case xyzModem_noZmodem:
      return "Sorry, zModem not available yet";
      break;
    case xyzModem_timeout:
      return "Timed out";
      break;
    case xyzModem_eof:
      return "End of file";
      break;
    case xyzModem_cancel:
      return "Cancelled";
      break;
    case xyzModem_frame:
      return "Invalid framing";
      break;
    case xyzModem_cksum:
      return "CRC/checksum error";
      break;
    case xyzModem_sequence:
      return "Block sequence error";
      break;
    default:
      return "Unknown error";
      break;
    }
}

/*
 * RedBoot interface
 */