bertos/net/xmodem.c

   1 /**
   2  * \file
   3  * <!--
   4  * This file is part of BeRTOS.
   5  *
   6  * Bertos is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  *
  20  * As a special exception, you may use this file as part of a free software
  21  * library without restriction.  Specifically, if other files instantiate
  22  * templates or use macros or inline functions from this file, or you compile
  23  * this file and link it with other files to produce an executable, this
  24  * file does not by itself cause the resulting executable to be covered by
  25  * the GNU General Public License.  This exception does not however
  26  * invalidate any other reasons why the executable file might be covered by
  27  * the GNU General Public License.
  28  *
  29  * Copyright 2004, 2005, 2006, 2007 Develer S.r.l. (http://www.develer.com/)
  30  * Copyright 1999, 2001 Bernie Innocenti <bernie@codewiz.org>
  31  *
  32  * -->
  33  *
  34  * \brief X-Modem serial transmission protocol (implementation)
  35  *
  36  * Supports the CRC-16 and 1K-blocks variants of the standard.
  37  * \see ymodem.txt for the protocol description.
  38  *
  39  * \todo Break xmodem_send() and xmodem_recv() in smaller functions.
  40  *
  41  * \version $Id$
  42  *
  43  * \author Bernie Innocenti <bernie@codewiz.org>
  44  * \author Francesco Sacchi <batt@develer.com>
  45  */
  46
  47
  48 #include "xmodem.h"
  49
  50 #include "cfg/cfg_xmodem.h"
  51 #include <cfg/debug.h>
  52
  53 #include <algo/crc.h>
  54
  55 #include <string.h> /* for memset() */
  56
  57 /**
  58  * \name Protocol control codes
  59  * \{
  60  */
  61 #define XM_SOH  0x01  /**< Start Of Header (128-byte block) */
  62 #define XM_STX  0x02  /**< Start Of Header (1024-byte block) */
  63 #define XM_EOT  0x04  /**< End Of Transmission */
  64 #define XM_ACK  0x06  /**< Acknowledge block */
  65 #define XM_NAK  0x15  /**< Negative Acknowledge */
  66 #define XM_C    0x43  /**< Request CRC-16 transmission */
  67 #define XM_CAN  0x18  /**< CANcel transmission */
  68 /*\}*/
  69
  70 #if CONFIG_XMODEM_1KCRC == 1
  71         #define XM_BUFSIZE       1024  /**< 1024 bytes of block buffer */
  72 #else
  73         #define XM_BUFSIZE       128   /**< 128 bytes of block buffer */
  74 #endif
  75
  76
  77 #if CONFIG_XMODEM_RECV
  78 /**
  79  * \brief Receive a file using the XModem protocol.
  80  *
  81  * \param ch Channel to use for transfer
  82  * \param fd Destination file
  83  *
  84  * \note This function allocates a large amount of stack (\see XM_BUFSIZE).
  85  */
  86 bool xmodem_recv(KFile *ch, KFile *fd)
  87 {
  88         char block_buffer[XM_BUFSIZE]; /* Buffer to hold a block of data */
  89         int c, i, blocksize;
  90         int blocknr = 0, last_block_done = 0, retries = 0;
  91         char *buf;
  92         uint8_t checksum;
  93         uint16_t crc;
  94         bool purge = false;
  95         bool usecrc = true;
  96
  97
  98         XMODEM_PROGRESS("Starting Transfer...\n");
  99         purge = true;
 100         kfile_clearerr(ch);
 101
 102         /* Send initial NAK to start transmission */
 103         for(;;)
 104         {
 105                 if (XMODEM_CHECK_ABORT)
 106                 {
 107                         kfile_putc(XM_CAN, ch);
 108                         kfile_putc(XM_CAN, ch);
 109                         XMODEM_PROGRESS("Transfer aborted\n");
 110                         return false;
 111                 }
 112
 113                 /*
 114                  * Discard incoming input until a timeout occurs, then send
 115                  * a NAK to the transmitter.
 116                  */
 117                 if (purge)
 118                 {
 119                         purge = false;
 120
 121                         if (kfile_error(ch))
 122                                 XMODEM_PROGRESS("Retries %d\n", retries);
 123
 124                         kfile_resync(ch, 200);
 125                         retries++;
 126
 127                         if (retries >= CONFIG_XMODEM_MAXRETRIES)
 128                         {
 129                                 kfile_putc(XM_CAN, ch);
 130                                 kfile_putc(XM_CAN, ch);
 131                                 XMODEM_PROGRESS("Transfer aborted\n");
 132                                 return false;
 133                         }
 134
 135                         /* Transmission start? */
 136                         if (blocknr == 0)
 137                         {
 138                                 if (retries < CONFIG_XMODEM_MAXCRCRETRIES)
 139                                 {
 140                                         XMODEM_PROGRESS("Request Tx (CRC)\n");
 141                                         kfile_putc(XM_C, ch);
 142                                 }
 143                                 else
 144                                 {
 145                                         /* Give up with CRC and fall back to checksum */
 146                                         usecrc = false;
 147                                         XMODEM_PROGRESS("Request Tx (BCC)\n");
 148                                         kfile_putc(XM_NAK, ch);
 149                                 }
 150                         }
 151                         else
 152                                 kfile_putc(XM_NAK, ch);
 153                 }
 154
 155                 switch (kfile_getc(ch))
 156                 {
 157                 #if XM_BUFSIZE >= 1024
 158                 case XM_STX:  /* Start of header (1024-byte block) */
 159                         blocksize = 1024;
 160                         goto getblock;
 161                 #endif
 162
 163                 case XM_SOH:  /* Start of header (128-byte block) */
 164                         blocksize = 128;
 165                         /* Needed to avoid warning if XM_BUFSIZE < 1024 */
 166
 167                 getblock:
 168                         /* Get block number */
 169                         c = kfile_getc(ch);
 170
 171                         /* Check complemented block number */
 172                         if ((~c & 0xff) != kfile_getc(ch))
 173                         {
 174                                 XMODEM_PROGRESS("Bad blk (%d)\n", c);
 175                                 purge = true;
 176                                 break;
 177                         }
 178
 179                         /* Determine which block is being sent */
 180                         if (c == (blocknr & 0xff))
 181                                 /* Last block repeated */
 182                                 XMODEM_PROGRESS("Repeat blk %d\n", blocknr);
 183                         else if (c == ((blocknr + 1) & 0xff))
 184                                 /* Next block */
 185                                 XMODEM_PROGRESS("Recv blk %d\n", ++blocknr);
 186                         else
 187                         {
 188                                 /* Sync lost */
 189                                 XMODEM_PROGRESS("Sync lost (%d/%d)\n", c, blocknr);
 190                                 purge = true;
 191                                 break;
 192                         }
 193
 194                         buf = block_buffer;     /* Reset pointer to start of buffer */
 195                         checksum = 0;
 196                         crc = 0;
 197                         for (i = 0; i < blocksize; i++)
 198                         {
 199                                 if ((c = kfile_getc(ch)) == EOF)
 200                                 {
 201                                         purge = true;
 202                                         break;
 203                                 }
 204
 205                                 /* Store in buffer */
 206                                 *buf++ = (char)c;
 207
 208                                 /* Calculate block checksum or CRC */
 209                                 if (usecrc)
 210                                         crc = UPDCRC16(c, crc);
 211                                 else
 212                                         checksum += (char)c;
 213                         }
 214
 215                         if (purge)
 216                                 break;
 217
 218                         /* Get the checksum byte or the CRC-16 MSB */
 219                         if ((c = kfile_getc(ch)) == EOF)
 220                         {
 221                                 purge = true;
 222                                 break;
 223                         }
 224
 225                         if (usecrc)
 226                         {
 227                                 crc = UPDCRC16(c, crc);
 228
 229                                 /* Get CRC-16 LSB */
 230                                 if ((c = kfile_getc(ch)) == EOF)
 231                                 {
 232                                         purge = true;
 233                                         break;
 234                                 }
 235
 236                                 crc = UPDCRC16(c, crc);
 237
 238                                 if (crc)
 239                                 {
 240                                         XMODEM_PROGRESS("Bad CRC: %04x\n", crc);
 241                                         purge = true;
 242                                         break;
 243                                 }
 244                         }
 245                         /* Compare the checksum */
 246                         else if (c != checksum)
 247                         {
 248                                 XMODEM_PROGRESS("Bad sum: %04x/%04x\n", checksum, c);
 249                                 purge = true;
 250                                 break;
 251                         }
 252
 253                         /*
 254                          * Avoid flushing the same block twice.
 255                          * This could happen when the sender does not receive our
 256                          * acknowledge and resends the same block.
 257                          */
 258                         if (last_block_done < blocknr)
 259                         {
 260                                 /* Call user function to flush the buffer */
 261                                 if (kfile_write(fd, block_buffer, blocksize))
 262                                 {
 263                                         /* Acknowledge block and clear error counter */
 264                                         kfile_putc(XM_ACK, ch);
 265                                         retries = 0;
 266                                         last_block_done = blocknr;
 267                                 }
 268                                 else
 269                                 {
 270                                         /* User callback failed: abort transfer immediately */
 271                                         retries = CONFIG_XMODEM_MAXRETRIES;
 272                                         purge = true;
 273                                 }
 274                         }
 275                         break;
 276
 277                 case XM_EOT:    /* End of transmission */
 278                         kfile_putc(XM_ACK, ch);
 279                         XMODEM_PROGRESS("Transfer completed\n");
 280                         return true;
 281
 282                 case EOF: /* Timeout or serial error */
 283                         purge = true;
 284                         break;
 285
 286                 default:
 287                         XMODEM_PROGRESS("Skipping garbage\n");
 288                         purge = true;
 289                         break;
 290                 }
 291         } /* End forever */
 292 }
 293 #endif
 294
 295
 296 #if CONFIG_XMODEM_SEND
 297 /**
 298  * \brief Transmit some data using the XModem protocol.
 299  *
 300  * \param ch Channel to use for transfer
 301  * \param fd Source file
 302  *
 303  * \note This function allocates a large amount of stack for
 304  *       the XModem transfer buffer (\see XM_BUFSIZE).
 305  */
 306 bool xmodem_send(KFile *ch, KFile *fd)
 307 {
 308         char block_buffer[XM_BUFSIZE]; /* Buffer to hold a block of data */
 309         size_t size = -1;
 310         int blocknr = 1, retries = 0, c, i;
 311         bool proceed, usecrc = false;
 312         uint16_t crc;
 313         uint8_t sum;
 314
 315         /*
 316          * Reading a block can be very slow, so we read the first block early
 317          * to avoid receiving double XM_C char.
 318          * This could happen if we check for XM_C and then read the block, giving
 319          * the receiving device time to send another XM_C char misinterpretating
 320          * the blocks sent.
 321          */
 322         size = kfile_read(fd, block_buffer, XM_BUFSIZE);
 323
 324         kfile_clearerr(ch);
 325         XMODEM_PROGRESS("Wait remote host\n");
 326
 327         for(;;)
 328         {
 329                 proceed = false;
 330                 do
 331                 {
 332                         if (XMODEM_CHECK_ABORT)
 333                                 return false;
 334
 335                         switch (c = kfile_getc(ch))
 336                         {
 337                         case XM_NAK:
 338                                 XMODEM_PROGRESS("Resend blk %d\n", blocknr);
 339                                 proceed = true;
 340                                 break;
 341
 342                         case XM_C:
 343                                 if (c == XM_C)
 344                                 {
 345                                         XMODEM_PROGRESS("Tx start (CRC)\n");
 346                                         usecrc = true;
 347                                 }
 348                                 else
 349                                         XMODEM_PROGRESS("Tx start (BCC)\n");
 350
 351                                 proceed = true;
 352                                 break;
 353
 354                         case XM_ACK:
 355                                 /* End of transfer? */
 356                                 if (!size)
 357                                         return true;
 358
 359                                 /* Call user function to read in one block */
 360                                 size = kfile_read(fd, block_buffer, XM_BUFSIZE);
 361                                 XMODEM_PROGRESS("Send blk %d\n", blocknr);
 362                                 blocknr++;
 363                                 retries = 0;
 364                                 proceed = true;
 365                                 break;
 366
 367                         case EOF:
 368                                 kfile_clearerr(ch);
 369                                 retries++;
 370                                 XMODEM_PROGRESS("Retries %d\n", retries);
 371                                 if (retries <= CONFIG_XMODEM_MAXRETRIES)
 372                                         break;
 373                                 /* falling through! */
 374
 375                         case XM_CAN:
 376                                 XMODEM_PROGRESS("Transfer aborted\n");
 377                                 return false;
 378
 379                         default:
 380                                 XMODEM_PROGRESS("Skipping garbage\n");
 381                                 break;
 382                         }
 383                 }
 384                 while (!proceed);
 385
 386                 if (!size)
 387                 {
 388                         kfile_putc(XM_EOT, ch);
 389                         continue;
 390                 }
 391
 392                 /* Pad block with 0xFF if it's partially full */
 393                 memset(block_buffer + size, 0xFF, XM_BUFSIZE - size);
 394
 395                 /* Send block header (STX, blocknr, ~blocknr) */
 396                 #if XM_BUFSIZE == 128
 397                         kfile_putc(XM_SOH, ch);
 398                 #else
 399                         kfile_putc(XM_STX, ch);
 400                 #endif
 401                 kfile_putc(blocknr & 0xFF, ch);
 402                 kfile_putc(~blocknr & 0xFF, ch);
 403
 404                 /* Send block and compute its CRC/checksum */
 405                 sum = 0;
 406                 crc = 0;
 407                 for (i = 0; i < XM_BUFSIZE; i++)
 408                 {
 409                         kfile_putc(block_buffer[i], ch);
 410                         crc = UPDCRC16(block_buffer[i], crc);
 411                         sum += block_buffer[i];
 412                 }
 413
 414                 /* Send CRC/Checksum */
 415                 if (usecrc)
 416                 {
 417                         crc = UPDCRC16(0, crc);
 418                         crc = UPDCRC16(0, crc);
 419                         kfile_putc(crc >> 8, ch);
 420                         kfile_putc(crc & 0xFF, ch);
 421                 }
 422                 else
 423                         kfile_putc(sum, ch);
 424         }
 425 }
 426 #endif