1 /*
2 *==========================================================================
3 *
4 * xyzModem.c
5 *
6 * RedBoot stream handler for xyzModem protocol
7 *
8 *==========================================================================
9 * SPDX-License-Identifier: eCos-2.0
10 *==========================================================================
11 *#####DESCRIPTIONBEGIN####
12 *
13 * Author(s): gthomas
14 * Contributors: gthomas, tsmith, Yoshinori Sato
15 * Date: 2000-07-14
16 * Purpose:
17 * Description:
18 *
19 * This code is part of RedBoot (tm).
20 *
21 *####DESCRIPTIONEND####
22 *
23 *==========================================================================
24 */
25 #include <common.h>
26 #include <xyzModem.h>
27 #include <stdarg.h>
28 #include <crc.h>
29
30 /* Assumption - run xyzModem protocol over the console port */
31
32 /* Values magic to the protocol */
33 #define SOH 0x01
34 #define STX 0x02
35 #define EOT 0x04
36 #define ACK 0x06
37 #define BSP 0x08
38 #define NAK 0x15
39 #define CAN 0x18
40 #define EOF 0x1A /* ^Z for DOS officionados */
41
42 /* Data & state local to the protocol */
43 static struct
44 {
45 int *__chan;
46 unsigned char pkt[1024], *bufp;
47 unsigned char blk, cblk, crc1, crc2;
48 unsigned char next_blk; /* Expected block */
49 int len, mode, total_retries;
50 int total_SOH, total_STX, total_CAN;
51 bool crc_mode, at_eof, tx_ack;
52 unsigned long file_length, read_length;
53 } xyz;
54
55 #define _xyzModem_CHAR_TIMEOUT 2000 /* 2 seconds */
56 #define xyzModem_MAX_RETRIES 20
57 #define xyzModem_MAX_RETRIES_WITH_CRC 10
58 #define xyzModem_CAN_COUNT 3 /* Wait for 3 CAN before quitting */
59
60 int xyzModem_CHAR_TIMEOUT = _xyzModem_CHAR_TIMEOUT;
61
62 typedef int cyg_int32;
63 int
CYGACC_COMM_IF_GETC_TIMEOUT(char chan,char * c)64 CYGACC_COMM_IF_GETC_TIMEOUT (char chan, char *c)
65 {
66
67 ulong now = get_timer(0);
68 while (!tstc ())
69 {
70 if (get_timer(now) > xyzModem_CHAR_TIMEOUT)
71 break;
72 }
73 if (tstc ())
74 {
75 *c = getc ();
76 return 1;
77 }
78 return 0;
79 }
80
81 void
CYGACC_COMM_IF_PUTC(char x,char y)82 CYGACC_COMM_IF_PUTC (char x, char y)
83 {
84 putc (y);
85 }
86
87 /* Validate a hex character */
88 __inline__ static bool
_is_hex(char c)89 _is_hex (char c)
90 {
91 return (((c >= '0') && (c <= '9')) ||
92 ((c >= 'A') && (c <= 'F')) || ((c >= 'a') && (c <= 'f')));
93 }
94
95 /* Convert a single hex nibble */
96 __inline__ static int
_from_hex(char c)97 _from_hex (char c)
98 {
99 int ret = 0;
100
101 if ((c >= '0') && (c <= '9'))
102 {
103 ret = (c - '0');
104 }
105 else if ((c >= 'a') && (c <= 'f'))
106 {
107 ret = (c - 'a' + 0x0a);
108 }
109 else if ((c >= 'A') && (c <= 'F'))
110 {
111 ret = (c - 'A' + 0x0A);
112 }
113 return ret;
114 }
115
116 /* Convert a character to lower case */
117 __inline__ static char
_tolower(char c)118 _tolower (char c)
119 {
120 if ((c >= 'A') && (c <= 'Z'))
121 {
122 c = (c - 'A') + 'a';
123 }
124 return c;
125 }
126
127 /* Parse (scan) a number */
128 static bool
parse_num(char * s,unsigned long * val,char ** es,char * delim)129 parse_num (char *s, unsigned long *val, char **es, char *delim)
130 {
131 bool first = true;
132 int radix = 10;
133 char c;
134 unsigned long result = 0;
135 int digit;
136
137 while (*s == ' ')
138 s++;
139 while (*s)
140 {
141 if (first && (s[0] == '0') && (_tolower (s[1]) == 'x'))
142 {
143 radix = 16;
144 s += 2;
145 }
146 first = false;
147 c = *s++;
148 if (_is_hex (c) && ((digit = _from_hex (c)) < radix))
149 {
150 /* Valid digit */
151 result = (result * radix) + digit;
152 }
153 else
154 {
155 if (delim != (char *) 0)
156 {
157 /* See if this character is one of the delimiters */
158 char *dp = delim;
159 while (*dp && (c != *dp))
160 dp++;
161 if (*dp)
162 break; /* Found a good delimiter */
163 }
164 return false; /* Malformatted number */
165 }
166 }
167 *val = result;
168 if (es != (char **) 0)
169 {
170 *es = s;
171 }
172 return true;
173 }
174
175
176 #ifdef DEBUG
177 /*
178 * Note: this debug setup works by storing the strings in a fixed buffer
179 */
180 static char zm_debug_buf[8192];
181 static char *zm_out = zm_debug_buf;
182 static char *zm_out_start = zm_debug_buf;
183
184 static int
zm_dprintf(char * fmt,...)185 zm_dprintf (char *fmt, ...)
186 {
187 int len;
188 va_list args;
189
190 va_start (args, fmt);
191 len = diag_vsprintf (zm_out, fmt, args);
192 zm_out += len;
193 return len;
194 }
195
196 static void
zm_flush(void)197 zm_flush (void)
198 {
199 zm_out = zm_out_start;
200 }
201
202 static void
zm_dump_buf(void * buf,int len)203 zm_dump_buf (void *buf, int len)
204 {
205
206 }
207
208 static unsigned char zm_buf[2048];
209 static unsigned char *zm_bp;
210
211 static void
zm_new(void)212 zm_new (void)
213 {
214 zm_bp = zm_buf;
215 }
216
217 static void
zm_save(unsigned char c)218 zm_save (unsigned char c)
219 {
220 *zm_bp++ = c;
221 }
222
223 static void
zm_dump(int line)224 zm_dump (int line)
225 {
226 zm_dprintf ("Packet at line: %d\n", line);
227 zm_dump_buf (zm_buf, zm_bp - zm_buf);
228 }
229
230 #define ZM_DEBUG(x) x
231 #else
232 #define ZM_DEBUG(x)
233 #endif
234
235 /* Wait for the line to go idle */
236 static void
xyzModem_flush(void)237 xyzModem_flush (void)
238 {
239 int res;
240 char c;
241 while (true)
242 {
243 res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, &c);
244 if (!res)
245 return;
246 }
247 }
248
249 static int
xyzModem_get_hdr(void)250 xyzModem_get_hdr (void)
251 {
252 char c;
253 int res;
254 bool hdr_found = false;
255 int i, can_total, hdr_chars;
256 unsigned short cksum;
257
258 ZM_DEBUG (zm_new ());
259 /* Find the start of a header */
260 can_total = 0;
261 hdr_chars = 0;
262
263 if (xyz.tx_ack)
264 {
265 CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
266 xyz.tx_ack = false;
267 }
268 while (!hdr_found)
269 {
270 res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, &c);
271 ZM_DEBUG (zm_save (c));
272 if (res)
273 {
274 hdr_chars++;
275 switch (c)
276 {
277 case SOH:
278 xyz.total_SOH++;
279 case STX:
280 if (c == STX)
281 xyz.total_STX++;
282 hdr_found = true;
283 break;
284 case CAN:
285 xyz.total_CAN++;
286 ZM_DEBUG (zm_dump (__LINE__));
287 if (++can_total == xyzModem_CAN_COUNT)
288 {
289 return xyzModem_cancel;
290 }
291 else
292 {
293 /* Wait for multiple CAN to avoid early quits */
294 break;
295 }
296 case EOT:
297 /* EOT only supported if no noise */
298 if (hdr_chars == 1)
299 {
300 CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
301 ZM_DEBUG (zm_dprintf ("ACK on EOT #%d\n", __LINE__));
302 ZM_DEBUG (zm_dump (__LINE__));
303 return xyzModem_eof;
304 }
305 default:
306 /* Ignore, waiting for start of header */
307 ;
308 }
309 }
310 else
311 {
312 /* Data stream timed out */
313 xyzModem_flush (); /* Toss any current input */
314 ZM_DEBUG (zm_dump (__LINE__));
315 CYGACC_CALL_IF_DELAY_US ((cyg_int32) 250000);
316 return xyzModem_timeout;
317 }
318 }
319
320 /* Header found, now read the data */
321 res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, (char *) &xyz.blk);
322 ZM_DEBUG (zm_save (xyz.blk));
323 if (!res)
324 {
325 ZM_DEBUG (zm_dump (__LINE__));
326 return xyzModem_timeout;
327 }
328 res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, (char *) &xyz.cblk);
329 ZM_DEBUG (zm_save (xyz.cblk));
330 if (!res)
331 {
332 ZM_DEBUG (zm_dump (__LINE__));
333 return xyzModem_timeout;
334 }
335 xyz.len = (c == SOH) ? 128 : 1024;
336 xyz.bufp = xyz.pkt;
337 for (i = 0; i < xyz.len; i++)
338 {
339 res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, &c);
340 ZM_DEBUG (zm_save (c));
341 if (res)
342 {
343 xyz.pkt[i] = c;
344 }
345 else
346 {
347 ZM_DEBUG (zm_dump (__LINE__));
348 return xyzModem_timeout;
349 }
350 }
351 res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, (char *) &xyz.crc1);
352 ZM_DEBUG (zm_save (xyz.crc1));
353 if (!res)
354 {
355 ZM_DEBUG (zm_dump (__LINE__));
356 return xyzModem_timeout;
357 }
358 if (xyz.crc_mode)
359 {
360 res = CYGACC_COMM_IF_GETC_TIMEOUT (*xyz.__chan, (char *) &xyz.crc2);
361 ZM_DEBUG (zm_save (xyz.crc2));
362 if (!res)
363 {
364 ZM_DEBUG (zm_dump (__LINE__));
365 return xyzModem_timeout;
366 }
367 }
368 ZM_DEBUG (zm_dump (__LINE__));
369 /* Validate the message */
370 if ((xyz.blk ^ xyz.cblk) != (unsigned char) 0xFF)
371 {
372 ZM_DEBUG (zm_dprintf
373 ("Framing error - blk: %x/%x/%x\n", xyz.blk, xyz.cblk,
374 (xyz.blk ^ xyz.cblk)));
375 ZM_DEBUG (zm_dump_buf (xyz.pkt, xyz.len));
376 xyzModem_flush ();
377 return xyzModem_frame;
378 }
379 /* Verify checksum/CRC */
380 if (xyz.crc_mode)
381 {
382 cksum = crc16_ccitt(0, xyz.pkt, xyz.len);
383 if (cksum != ((xyz.crc1 << 8) | xyz.crc2))
384 {
385 ZM_DEBUG (zm_dprintf ("CRC error - recvd: %02x%02x, computed: %x\n",
386 xyz.crc1, xyz.crc2, cksum & 0xFFFF));
387 return xyzModem_cksum;
388 }
389 }
390 else
391 {
392 cksum = 0;
393 for (i = 0; i < xyz.len; i++)
394 {
395 cksum += xyz.pkt[i];
396 }
397 if (xyz.crc1 != (cksum & 0xFF))
398 {
399 ZM_DEBUG (zm_dprintf
400 ("Checksum error - recvd: %x, computed: %x\n", xyz.crc1,
401 cksum & 0xFF));
402 return xyzModem_cksum;
403 }
404 }
405 /* If we get here, the message passes [structural] muster */
406 return 0;
407 }
408
409 int
xyzModem_stream_open(connection_info_t * info,int * err)410 xyzModem_stream_open (connection_info_t * info, int *err)
411 {
412 int stat = 0;
413 int retries = xyzModem_MAX_RETRIES;
414 int crc_retries = xyzModem_MAX_RETRIES_WITH_CRC;
415
416 /* ZM_DEBUG(zm_out = zm_out_start); */
417 #ifdef xyzModem_zmodem
418 if (info->mode == xyzModem_zmodem)
419 {
420 *err = xyzModem_noZmodem;
421 return -1;
422 }
423 #endif
424
425 /* TODO: CHECK ! */
426 int dummy = 0;
427 xyz.__chan = &dummy;
428 xyz.len = 0;
429 xyz.crc_mode = true;
430 xyz.at_eof = false;
431 xyz.tx_ack = false;
432 xyz.mode = info->mode;
433 xyz.total_retries = 0;
434 xyz.total_SOH = 0;
435 xyz.total_STX = 0;
436 xyz.total_CAN = 0;
437 xyz.read_length = 0;
438 xyz.file_length = 0;
439
440 CYGACC_COMM_IF_PUTC (*xyz.__chan, (xyz.crc_mode ? 'C' : NAK));
441
442 if (xyz.mode == xyzModem_xmodem)
443 {
444 /* X-modem doesn't have an information header - exit here */
445 xyz.next_blk = 1;
446 return 0;
447 }
448
449 while (retries-- > 0)
450 {
451 stat = xyzModem_get_hdr ();
452 if (stat == 0)
453 {
454 /* Y-modem file information header */
455 if (xyz.blk == 0)
456 {
457 /* skip filename */
458 while (*xyz.bufp++);
459 /* get the length */
460 parse_num ((char *) xyz.bufp, &xyz.file_length, NULL, " ");
461 /* The rest of the file name data block quietly discarded */
462 xyz.tx_ack = true;
463 }
464 xyz.next_blk = 1;
465 xyz.len = 0;
466 return 0;
467 }
468 else if (stat == xyzModem_timeout)
469 {
470 if (--crc_retries <= 0)
471 xyz.crc_mode = false;
472 CYGACC_CALL_IF_DELAY_US (5 * 100000); /* Extra delay for startup */
473 CYGACC_COMM_IF_PUTC (*xyz.__chan, (xyz.crc_mode ? 'C' : NAK));
474 xyz.total_retries++;
475 ZM_DEBUG (zm_dprintf ("NAK (%d)\n", __LINE__));
476 }
477 if (stat == xyzModem_cancel)
478 {
479 break;
480 }
481 }
482 *err = stat;
483 ZM_DEBUG (zm_flush ());
484 return -1;
485 }
486
487 int
xyzModem_stream_read(char * buf,int size,int * err)488 xyzModem_stream_read (char *buf, int size, int *err)
489 {
490 int stat, total, len;
491 int retries;
492
493 total = 0;
494 stat = xyzModem_cancel;
495 /* Try and get 'size' bytes into the buffer */
496 while (!xyz.at_eof && (size > 0))
497 {
498 if (xyz.len == 0)
499 {
500 retries = xyzModem_MAX_RETRIES;
501 while (retries-- > 0)
502 {
503 stat = xyzModem_get_hdr ();
504 if (stat == 0)
505 {
506 if (xyz.blk == xyz.next_blk)
507 {
508 xyz.tx_ack = true;
509 ZM_DEBUG (zm_dprintf
510 ("ACK block %d (%d)\n", xyz.blk, __LINE__));
511 xyz.next_blk = (xyz.next_blk + 1) & 0xFF;
512
513 if (xyz.mode == xyzModem_xmodem || xyz.file_length == 0)
514 {
515 /* Data blocks can be padded with ^Z (EOF) characters */
516 /* This code tries to detect and remove them */
517 if ((xyz.bufp[xyz.len - 1] == EOF) &&
518 (xyz.bufp[xyz.len - 2] == EOF) &&
519 (xyz.bufp[xyz.len - 3] == EOF))
520 {
521 while (xyz.len
522 && (xyz.bufp[xyz.len - 1] == EOF))
523 {
524 xyz.len--;
525 }
526 }
527 }
528
529 /*
530 * See if accumulated length exceeds that of the file.
531 * If so, reduce size (i.e., cut out pad bytes)
532 * Only do this for Y-modem (and Z-modem should it ever
533 * be supported since it can fall back to Y-modem mode).
534 */
535 if (xyz.mode != xyzModem_xmodem && 0 != xyz.file_length)
536 {
537 xyz.read_length += xyz.len;
538 if (xyz.read_length > xyz.file_length)
539 {
540 xyz.len -= (xyz.read_length - xyz.file_length);
541 }
542 }
543 break;
544 }
545 else if (xyz.blk == ((xyz.next_blk - 1) & 0xFF))
546 {
547 /* Just re-ACK this so sender will get on with it */
548 CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
549 continue; /* Need new header */
550 }
551 else
552 {
553 stat = xyzModem_sequence;
554 }
555 }
556 if (stat == xyzModem_cancel)
557 {
558 break;
559 }
560 if (stat == xyzModem_eof)
561 {
562 CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
563 ZM_DEBUG (zm_dprintf ("ACK (%d)\n", __LINE__));
564 if (xyz.mode == xyzModem_ymodem)
565 {
566 CYGACC_COMM_IF_PUTC (*xyz.__chan,
567 (xyz.crc_mode ? 'C' : NAK));
568 xyz.total_retries++;
569 ZM_DEBUG (zm_dprintf ("Reading Final Header\n"));
570 stat = xyzModem_get_hdr ();
571 CYGACC_COMM_IF_PUTC (*xyz.__chan, ACK);
572 ZM_DEBUG (zm_dprintf ("FINAL ACK (%d)\n", __LINE__));
573 }
574 xyz.at_eof = true;
575 break;
576 }
577 CYGACC_COMM_IF_PUTC (*xyz.__chan, (xyz.crc_mode ? 'C' : NAK));
578 xyz.total_retries++;
579 ZM_DEBUG (zm_dprintf ("NAK (%d)\n", __LINE__));
580 }
581 if (stat < 0)
582 {
583 *err = stat;
584 xyz.len = -1;
585 return total;
586 }
587 }
588 /* Don't "read" data from the EOF protocol package */
589 if (!xyz.at_eof)
590 {
591 len = xyz.len;
592 if (size < len)
593 len = size;
594 memcpy (buf, xyz.bufp, len);
595 size -= len;
596 buf += len;
597 total += len;
598 xyz.len -= len;
599 xyz.bufp += len;
600 }
601 }
602 return total;
603 }
604
605 void
xyzModem_stream_close(int * err)606 xyzModem_stream_close (int *err)
607 {
608 diag_printf
609 ("xyzModem - %s mode, %d(SOH)/%d(STX)/%d(CAN) packets, %d retries\n",
610 xyz.crc_mode ? "CRC" : "Cksum", xyz.total_SOH, xyz.total_STX,
611 xyz.total_CAN, xyz.total_retries);
612 ZM_DEBUG (zm_flush ());
613 }
614
615 /* Need to be able to clean out the input buffer, so have to take the */
616 /* getc */
617 void
xyzModem_stream_terminate(bool abort,int (* getc)(void))618 xyzModem_stream_terminate (bool abort, int (*getc) (void))
619 {
620 int c;
621
622 if (abort)
623 {
624 ZM_DEBUG (zm_dprintf ("!!!! TRANSFER ABORT !!!!\n"));
625 switch (xyz.mode)
626 {
627 case xyzModem_xmodem:
628 case xyzModem_ymodem:
629 /* The X/YMODEM Spec seems to suggest that multiple CAN followed by an equal */
630 /* number of Backspaces is a friendly way to get the other end to abort. */
631 CYGACC_COMM_IF_PUTC (*xyz.__chan, CAN);
632 CYGACC_COMM_IF_PUTC (*xyz.__chan, CAN);
633 CYGACC_COMM_IF_PUTC (*xyz.__chan, CAN);
634 CYGACC_COMM_IF_PUTC (*xyz.__chan, CAN);
635 CYGACC_COMM_IF_PUTC (*xyz.__chan, BSP);
636 CYGACC_COMM_IF_PUTC (*xyz.__chan, BSP);
637 CYGACC_COMM_IF_PUTC (*xyz.__chan, BSP);
638 CYGACC_COMM_IF_PUTC (*xyz.__chan, BSP);
639 /* Now consume the rest of what's waiting on the line. */
640 ZM_DEBUG (zm_dprintf ("Flushing serial line.\n"));
641 xyzModem_flush ();
642 xyz.at_eof = true;
643 break;
644 #ifdef xyzModem_zmodem
645 case xyzModem_zmodem:
646 /* Might support it some day I suppose. */
647 #endif
648 break;
649 }
650 }
651 else
652 {
653 ZM_DEBUG (zm_dprintf ("Engaging cleanup mode...\n"));
654 /*
655 * Consume any trailing crap left in the inbuffer from
656 * previous received blocks. Since very few files are an exact multiple
657 * of the transfer block size, there will almost always be some gunk here.
658 * If we don't eat it now, RedBoot will think the user typed it.
659 */
660 ZM_DEBUG (zm_dprintf ("Trailing gunk:\n"));
661 while ((c = (*getc) ()) > -1)
662 ;
663 ZM_DEBUG (zm_dprintf ("\n"));
664 /*
665 * Make a small delay to give terminal programs like minicom
666 * time to get control again after their file transfer program
667 * exits.
668 */
669 CYGACC_CALL_IF_DELAY_US ((cyg_int32) 250000);
670 }
671 }
672
673 char *
xyzModem_error(int err)674 xyzModem_error (int err)
675 {
676 switch (err)
677 {
678 case xyzModem_access:
679 return "Can't access file";
680 break;
681 case xyzModem_noZmodem:
682 return "Sorry, zModem not available yet";
683 break;
684 case xyzModem_timeout:
685 return "Timed out";
686 break;
687 case xyzModem_eof:
688 return "End of file";
689 break;
690 case xyzModem_cancel:
691 return "Cancelled";
692 break;
693 case xyzModem_frame:
694 return "Invalid framing";
695 break;
696 case xyzModem_cksum:
697 return "CRC/checksum error";
698 break;
699 case xyzModem_sequence:
700 return "Block sequence error";
701 break;
702 default:
703 return "Unknown error";
704 break;
705 }
706 }
707
708 /*
709 * RedBoot interface
710 */
711