src/lib/xmodem.c

   1 /*
   2         Copyright 2006 Arastra, Inc.
   3         Copyright 2001, 2002 Georges Menie (www.menie.org)
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU Lesser General Public License as published by
   7     the Free Software Foundation; either version 2 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU Lesser General Public License for more details.
  14
  15     You should have received a copy of the GNU Lesser General Public License
  16     along with this program; if not, write to the Free Software
  17     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18 */
  19
  20 #include <string.h>
  21 #include <delay.h>
  22
  23 extern void uart8250_tx_byte(unsigned, unsigned char);
  24 extern int uart8250_can_rx_byte(unsigned);
  25 extern unsigned char uart8250_rx_byte(unsigned);
  26
  27 static int _inbyte(int msec)
  28 {
  29         while (!uart8250_can_rx_byte(TTYS0_BASE)) {
  30                 udelay(1000);
  31                 if (msec-- <= 0)
  32                         return -1;
  33         }
  34         return uart8250_rx_byte(TTYS0_BASE);
  35 }
  36
  37 static void _outbyte(unsigned char c)
  38 {
  39         uart8250_tx_byte(TTYS0_BASE, c);
  40 }
  41
  42 /* CRC16 implementation acording to CCITT standards */
  43
  44 static const unsigned short crc16tab[256]= {
  45         0x0000,0x1021,0x2042,0x3063,0x4084,0x50a5,0x60c6,0x70e7,
  46         0x8108,0x9129,0xa14a,0xb16b,0xc18c,0xd1ad,0xe1ce,0xf1ef,
  47         0x1231,0x0210,0x3273,0x2252,0x52b5,0x4294,0x72f7,0x62d6,
  48         0x9339,0x8318,0xb37b,0xa35a,0xd3bd,0xc39c,0xf3ff,0xe3de,
  49         0x2462,0x3443,0x0420,0x1401,0x64e6,0x74c7,0x44a4,0x5485,
  50         0xa56a,0xb54b,0x8528,0x9509,0xe5ee,0xf5cf,0xc5ac,0xd58d,
  51         0x3653,0x2672,0x1611,0x0630,0x76d7,0x66f6,0x5695,0x46b4,
  52         0xb75b,0xa77a,0x9719,0x8738,0xf7df,0xe7fe,0xd79d,0xc7bc,
  53         0x48c4,0x58e5,0x6886,0x78a7,0x0840,0x1861,0x2802,0x3823,
  54         0xc9cc,0xd9ed,0xe98e,0xf9af,0x8948,0x9969,0xa90a,0xb92b,
  55         0x5af5,0x4ad4,0x7ab7,0x6a96,0x1a71,0x0a50,0x3a33,0x2a12,
  56         0xdbfd,0xcbdc,0xfbbf,0xeb9e,0x9b79,0x8b58,0xbb3b,0xab1a,
  57         0x6ca6,0x7c87,0x4ce4,0x5cc5,0x2c22,0x3c03,0x0c60,0x1c41,
  58         0xedae,0xfd8f,0xcdec,0xddcd,0xad2a,0xbd0b,0x8d68,0x9d49,
  59         0x7e97,0x6eb6,0x5ed5,0x4ef4,0x3e13,0x2e32,0x1e51,0x0e70,
  60         0xff9f,0xefbe,0xdfdd,0xcffc,0xbf1b,0xaf3a,0x9f59,0x8f78,
  61         0x9188,0x81a9,0xb1ca,0xa1eb,0xd10c,0xc12d,0xf14e,0xe16f,
  62         0x1080,0x00a1,0x30c2,0x20e3,0x5004,0x4025,0x7046,0x6067,
  63         0x83b9,0x9398,0xa3fb,0xb3da,0xc33d,0xd31c,0xe37f,0xf35e,
  64         0x02b1,0x1290,0x22f3,0x32d2,0x4235,0x5214,0x6277,0x7256,
  65         0xb5ea,0xa5cb,0x95a8,0x8589,0xf56e,0xe54f,0xd52c,0xc50d,
  66         0x34e2,0x24c3,0x14a0,0x0481,0x7466,0x6447,0x5424,0x4405,
  67         0xa7db,0xb7fa,0x8799,0x97b8,0xe75f,0xf77e,0xc71d,0xd73c,
  68         0x26d3,0x36f2,0x0691,0x16b0,0x6657,0x7676,0x4615,0x5634,
  69         0xd94c,0xc96d,0xf90e,0xe92f,0x99c8,0x89e9,0xb98a,0xa9ab,
  70         0x5844,0x4865,0x7806,0x6827,0x18c0,0x08e1,0x3882,0x28a3,
  71         0xcb7d,0xdb5c,0xeb3f,0xfb1e,0x8bf9,0x9bd8,0xabbb,0xbb9a,
  72         0x4a75,0x5a54,0x6a37,0x7a16,0x0af1,0x1ad0,0x2ab3,0x3a92,
  73         0xfd2e,0xed0f,0xdd6c,0xcd4d,0xbdaa,0xad8b,0x9de8,0x8dc9,
  74         0x7c26,0x6c07,0x5c64,0x4c45,0x3ca2,0x2c83,0x1ce0,0x0cc1,
  75         0xef1f,0xff3e,0xcf5d,0xdf7c,0xaf9b,0xbfba,0x8fd9,0x9ff8,
  76         0x6e17,0x7e36,0x4e55,0x5e74,0x2e93,0x3eb2,0x0ed1,0x1ef0
  77 };
  78
  79 static unsigned short crc16_ccitt(const void *buf, int len)
  80 {
  81         register int counter;
  82         register unsigned short crc = 0;
  83         for( counter = 0; counter < len; counter++)
  84                 crc = (crc<<8) ^ crc16tab[((crc>>8) ^ *(char *)buf++)&0x00FF];
  85         return crc;
  86 }
  87
  88 #define SOH  0x01
  89 #define STX  0x02
  90 #define EOT  0x04
  91 #define ACK  0x06
  92 #define NAK  0x15
  93 #define CAN  0x18
  94 #define CTRLZ 0x1A
  95
  96 #define DLY_1S 1000
  97 #define MAXRETRANS 25
  98
  99 static int check(int crc, const unsigned char *buf, int sz)
 100 {
 101         if (crc) {
 102                 unsigned short crc = crc16_ccitt(buf, sz);
 103                 unsigned short tcrc = (buf[sz]<<8)+buf[sz+1];
 104                 if (crc == tcrc)
 105                         return 1;
 106         }
 107         else {
 108                 int i;
 109                 unsigned char cks = 0;
 110                 for (i = 0; i < sz; ++i) {
 111                         cks += buf[i];
 112                 }
 113                 if (cks == buf[sz])
 114                 return 1;
 115         }
 116
 117         return 0;
 118 }
 119
 120 static void flushinput(void)
 121 {
 122         while (_inbyte(((DLY_1S)*3)>>1) >= 0)
 123                 ;
 124 }
 125
 126 int xmodemReceive(unsigned char *dest, int destsz)
 127 {
 128         unsigned char xbuff[1030]; /* 1024 for XModem 1k + 3 head chars + 2 crc + nul */
 129         unsigned char *p;
 130         int bufsz, crc = 0;
 131         unsigned char trychar = 'C';
 132         unsigned char packetno = 1;
 133         int i, c, len = 0;
 134         int retry, retrans = MAXRETRANS;
 135
 136         for(;;) {
 137                 for( retry = 0; retry < 16; ++retry) {
 138                         if (trychar) _outbyte(trychar);
 139                         if ((c = _inbyte((DLY_1S)<<1)) >= 0) {
 140                                 switch (c) {
 141                                 case SOH:
 142                                         bufsz = 128;
 143                                         goto start_recv;
 144                                 case STX:
 145                                         bufsz = 1024;
 146                                         goto start_recv;
 147                                 case EOT:
 148                                         flushinput();
 149                                         _outbyte(ACK);
 150                                         return len; /* normal end */
 151                                 case CAN:
 152                                         if ((c = _inbyte(DLY_1S)) == CAN) {
 153                                                 flushinput();
 154                                                 _outbyte(ACK);
 155                                                 return -1; /* canceled by remote */
 156                                         }
 157                                         break;
 158                                 default:
 159                                         break;
 160                                 }
 161                         }
 162                 }
 163                 if (trychar == 'C') { trychar = NAK; continue; }
 164                 flushinput();
 165                 _outbyte(CAN);
 166                 _outbyte(CAN);
 167                 _outbyte(CAN);
 168                 return -2; /* sync error */
 169
 170         start_recv:
 171                 if (trychar == 'C') crc = 1;
 172                 trychar = 0;
 173                 p = xbuff;
 174                 *p++ = c;
 175                 for (i = 0;  i < (bufsz+(crc?1:0)+3); ++i) {
 176                         if ((c = _inbyte(DLY_1S)) < 0) goto reject;
 177                         *p++ = c;
 178                 }
 179
 180                 if (xbuff[1] == (unsigned char)(~xbuff[2]) &&
 181                         (xbuff[1] == packetno || xbuff[1] == (unsigned char)packetno-1) &&
 182                         check(crc, &xbuff[3], bufsz)) {
 183                         if (xbuff[1] == packetno)       {
 184                                 register int count = destsz - len;
 185                                 if (count > bufsz) count = bufsz;
 186                                 if (count > 0) {
 187                                         memcpy (&dest[len], &xbuff[3], count);
 188                                         len += count;
 189                                 }
 190                                 ++packetno;
 191                                 retrans = MAXRETRANS+1;
 192                         }
 193                         if (--retrans <= 0) {
 194                                 flushinput();
 195                                 _outbyte(CAN);
 196                                 _outbyte(CAN);
 197                                 _outbyte(CAN);
 198                                 return -3; /* too many retry error */
 199                         }
 200                         _outbyte(ACK);
 201                         continue;
 202                 }
 203         reject:
 204                 flushinput();
 205                 _outbyte(NAK);
 206         }
 207 }