a6500ec8aa
changes in the future. This helps with getting started and to overcome the really sucky level of granuality this timeout has in getc. A timeout of 1 means 'wait until top of next second' rather than 'wait for at least a second'.
129 lines
3.4 KiB
C
129 lines
3.4 KiB
C
/*-
|
|
* Copyright (c) 2006 M. Warner Losh. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
|
|
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
|
|
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
|
|
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
|
|
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
|
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*
|
|
* This software is derived from software provide by Kwikbyte who specifically
|
|
* disclaimed copyright on the code. This version of xmodem has been nearly
|
|
* completely rewritten, but the CRC is from the original.
|
|
*
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
#include "lib.h"
|
|
|
|
#define PACKET_SIZE 128
|
|
|
|
/* Line control codes */
|
|
#define SOH 0x01 /* start of header */
|
|
#define ACK 0x06 /* Acknowledge */
|
|
#define NAK 0x15 /* Negative acknowledge */
|
|
#define CAN 0x18 /* Cancel */
|
|
#define EOT 0x04 /* end of text */
|
|
|
|
#define TO 10
|
|
/*
|
|
* int GetRecord(char , char *)
|
|
* This private function receives a x-modem record to the pointer and
|
|
* returns non-zero on success.
|
|
*/
|
|
static int
|
|
GetRecord(char blocknum, char *dest)
|
|
{
|
|
int size;
|
|
int ch;
|
|
unsigned chk, j;
|
|
|
|
chk = 0;
|
|
|
|
if ((ch = getc(TO)) == -1)
|
|
goto err;
|
|
if (ch != blocknum)
|
|
goto err;
|
|
if ((ch = getc(TO)) == -1)
|
|
goto err;
|
|
if (ch != (~blocknum & 0xff))
|
|
goto err;
|
|
|
|
for (size = 0; size < PACKET_SIZE; ++size) {
|
|
if ((ch = getc(TO)) == -1)
|
|
goto err;
|
|
chk = chk ^ ch << 8;
|
|
for (j = 0; j < 8; ++j) {
|
|
if (chk & 0x8000)
|
|
chk = chk << 1 ^ 0x1021;
|
|
else
|
|
chk = chk << 1;
|
|
}
|
|
*dest++ = ch;
|
|
}
|
|
|
|
chk &= 0xFFFF;
|
|
|
|
if (((ch = getc(TO)) == -1) || ((ch & 0xff) != ((chk >> 8) & 0xFF)))
|
|
goto err;
|
|
if (((ch = getc(TO)) == -1) || ((ch & 0xff) != (chk & 0xFF)))
|
|
goto err;
|
|
putchar(ACK);
|
|
|
|
return (1);
|
|
err:;
|
|
putchar(CAN);
|
|
// We should allow for resend, but we don't.
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* int xmodem_rx(char *)
|
|
* This global function receives a x-modem transmission consisting of
|
|
* (potentially) several blocks. Returns the number of bytes received or
|
|
* -1 on error.
|
|
*/
|
|
int
|
|
xmodem_rx(char *dest)
|
|
{
|
|
int starting, ch;
|
|
char packetNumber, *startAddress = dest;
|
|
|
|
packetNumber = 1;
|
|
starting = 1;
|
|
|
|
while (1) {
|
|
if (starting)
|
|
putchar('C');
|
|
if (((ch = getc(1)) == -1) || (ch != SOH && ch != EOT))
|
|
continue;
|
|
if (ch == EOT) {
|
|
putchar(ACK);
|
|
return (dest - startAddress);
|
|
}
|
|
starting = 0;
|
|
// Xmodem packets: SOH PKT# ~PKT# 128-bytes CRC16
|
|
if (!GetRecord(packetNumber, dest))
|
|
return (-1);
|
|
dest += PACKET_SIZE;
|
|
packetNumber++;
|
|
}
|
|
|
|
// the loop above should return in all cases
|
|
return (-1);
|
|
}
|