/* vi: set sw=4 ts=4: */
-/*-------------------------------------------------------------------------
- * Filename: xmodem.c
+/*
* Copyright: Copyright (C) 2001, Hewlett-Packard Company
* Author: Christopher Hoover <ch@hpl.hp.com>
* Description: xmodem functionality for uploading of kernels
* and the like
* Created at: Thu Dec 20 01:58:08 PST 2001
- *-----------------------------------------------------------------------*/
-/*
- * xmodem.c: xmodem functionality for uploading of kernels and
- * the like
+ *
+ * xmodem functionality for uploading of kernels and the like
*
* Copyright (C) 2001 Hewlett-Packard Laboratories
*
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*
* This was originally written for blob and then adapted for busybox.
*/
+//config:config RX
+//config: bool "rx (2.9 kb)"
+//config: default y
+//config: select PLATFORM_LINUX
+//config: help
+//config: Receive files using the Xmodem protocol.
+
+//applet:IF_RX(APPLET(rx, BB_DIR_USR_BIN, BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_RX) += rx.o
+
+//usage:#define rx_trivial_usage
+//usage: "FILE"
+//usage:#define rx_full_usage "\n\n"
+//usage: "Receive a file using the xmodem protocol"
+//usage:
+//usage:#define rx_example_usage
+//usage: "$ rx /tmp/foo\n"
#include "libbb.h"
#define ACK 0x06
#define NAK 0x15
#define BS 0x08
+#define PAD 0x1A
/*
Cf:
static int read_byte(unsigned timeout)
{
- char buf[1];
+ unsigned char buf;
int n;
alarm(timeout);
/* NOT safe_read! We want ALRM to interrupt us */
- n = read(read_fd, buf, 1);
+ n = read(read_fd, &buf, 1);
alarm(0);
if (n == 1)
- return (unsigned char)buf[0];
+ return buf;
return -1;
}
static int receive(/*int read_fd, */int file_fd)
{
unsigned char blockBuf[1024];
+ unsigned blockLength = 0;
unsigned errors = 0;
unsigned wantBlockNo = 1;
unsigned length = 0;
int do_crc = 1;
- char nak = 'C';
+ char reply_char;
unsigned timeout = TIMEOUT_LONG;
/* Flush pending input */
tcflush(read_fd, TCIFLUSH);
/* Ask for CRC; if we get errors, we will go with checksum */
- full_write(write_fd, &nak, 1);
+ reply_char = 'C';
+ full_write(write_fd, &reply_char, 1);
for (;;) {
int blockBegin;
int blockNo, blockNoOnesCompl;
- int blockLength;
- int cksum_crc; /* cksum OR crc */
- int expected;
- int i,j;
+ int cksum_or_crc;
+ unsigned expected;
+ int i, j;
blockBegin = read_byte(timeout);
if (blockBegin < 0)
goto timeout;
+ /* If last block, remove padding */
+ if (blockBegin == EOT) {
+ /* Data blocks can be padded with ^Z characters */
+ /* This code tries to detect and remove them */
+ if (blockLength >= 3
+ && blockBuf[blockLength - 1] == PAD
+ && blockBuf[blockLength - 2] == PAD
+ && blockBuf[blockLength - 3] == PAD
+ ) {
+ while (blockLength
+ && blockBuf[blockLength - 1] == PAD
+ ) {
+ blockLength--;
+ }
+ }
+ }
+ /* Write previously received block */
+ errno = 0;
+ if (full_write(file_fd, blockBuf, blockLength) != blockLength) {
+ bb_perror_msg(bb_msg_write_error);
+ goto fatal;
+ }
+
timeout = TIMEOUT;
- nak = NAK;
+ reply_char = NAK;
switch (blockBegin) {
case SOH:
case STX:
break;
-
case EOT:
- nak = ACK;
- full_write(write_fd, &nak, 1);
+ reply_char = ACK;
+ full_write(write_fd, &reply_char, 1);
return length;
-
default:
goto error;
}
- /* block no */
+ /* Block no */
blockNo = read_byte(TIMEOUT);
if (blockNo < 0)
goto timeout;
- /* block no one's compliment */
+ /* Block no, in one's complement form */
blockNoOnesCompl = read_byte(TIMEOUT);
if (blockNoOnesCompl < 0)
goto timeout;
blockBuf[i] = cc;
}
+ cksum_or_crc = read_byte(TIMEOUT);
+ if (cksum_or_crc < 0)
+ goto timeout;
if (do_crc) {
- cksum_crc = read_byte(TIMEOUT);
- if (cksum_crc < 0)
- goto timeout;
- cksum_crc = (cksum_crc << 8) | read_byte(TIMEOUT);
- if (cksum_crc < 0)
- goto timeout;
- } else {
- cksum_crc = read_byte(TIMEOUT);
- if (cksum_crc < 0)
+ cksum_or_crc = (cksum_or_crc << 8) | read_byte(TIMEOUT);
+ if (cksum_or_crc < 0)
goto timeout;
}
/* a repeat of the last block is ok, just ignore it. */
/* this also ignores the initial block 0 which is */
/* meta data. */
+ blockLength = 0;
goto next;
}
if (blockNo != (wantBlockNo & 0xff)) {
expected = expected ^ blockBuf[i] << 8;
for (j = 0; j < 8; j++) {
if (expected & 0x8000)
- expected = expected << 1 ^ 0x1021;
+ expected = (expected << 1) ^ 0x1021;
else
- expected = expected << 1;
+ expected = (expected << 1);
}
}
expected &= 0xffff;
expected += blockBuf[i];
expected &= 0xff;
}
- if (cksum_crc != expected) {
+ if (cksum_or_crc != expected) {
bb_error_msg(do_crc ? "crc error, expected 0x%04x, got 0x%04x"
- : "checksum error, expected 0x%02x, got 0x%02x",
- expected, cksum_crc);
+ : "checksum error, expected 0x%02x, got 0x%02x",
+ expected, cksum_or_crc);
goto error;
}
wantBlockNo++;
length += blockLength;
-
- errno = 0;
- if (full_write(file_fd, blockBuf, blockLength) != blockLength) {
- bb_perror_msg("can't write to file");
- goto fatal;
- }
next:
errors = 0;
- nak = ACK;
- full_write(write_fd, &nak, 1);
+ reply_char = ACK;
+ full_write(write_fd, &reply_char, 1);
continue;
error:
timeout:
+ blockLength = 0;
errors++;
if (errors == MAXERRORS) {
/* Abort */
- /* if were asking for crc, try again w/o crc */
- if (nak == 'C') {
- nak = NAK;
+ /* If were asking for crc, try again w/o crc */
+ if (reply_char == 'C') {
+ reply_char = NAK;
errors = 0;
do_crc = 0;
goto timeout;
/* Flush pending input */
tcflush(read_fd, TCIFLUSH);
- full_write(write_fd, &nak, 1);
+ full_write(write_fd, &reply_char, 1);
} /* for (;;) */
}
}
int rx_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int rx_main(int argc, char **argv)
+int rx_main(int argc UNUSED_PARAM, char **argv)
{
struct termios tty, orig_tty;
int termios_err;
int file_fd;
int n;
- if (argc != 2)
- bb_show_usage();
-
/* Disabled by vda:
* why we can't receive from stdin? Why we *require*
* controlling tty?? */
/*read_fd = xopen(CURRENT_TTY, O_RDWR);*/
- file_fd = xopen(argv[1], O_RDWR|O_CREAT|O_TRUNC);
+ file_fd = xopen(single_argv(argv), O_RDWR|O_CREAT|O_TRUNC);
termios_err = tcgetattr(read_fd, &tty);
if (termios_err == 0) {
+//TODO: use set_termios_to_raw()
orig_tty = tty;
cfmakeraw(&tty);
tcsetattr(read_fd, TCSAFLUSH, &tty);
projects / oweals / busybox.git / blobdiff