common/xyzModem.c

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