/* 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.
- *
*/
-#include "busybox.h"
+//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 SOH 0x01
#define STX 0x02
#define ACK 0x06
#define NAK 0x15
#define BS 0x08
+#define PAD 0x1A
/*
-
Cf:
-
http://www.textfiles.com/apple/xmodem
http://www.phys.washington.edu/~belonis/xmodem/docxmodem.txt
http://www.phys.washington.edu/~belonis/xmodem/docymodem.txt
http://www.phys.washington.edu/~belonis/xmodem/modmprot.col
-
*/
#define TIMEOUT 1
#define TIMEOUT_LONG 10
#define MAXERRORS 10
-static int read_byte(int fd, unsigned int timeout) {
- char buf[1];
+#define read_fd STDIN_FILENO
+#define write_fd STDOUT_FILENO
+
+static int read_byte(unsigned timeout)
+{
+ unsigned char buf;
int n;
alarm(timeout);
-
- n = read(fd, &buf, 1);
-
+ /* NOT safe_read! We want ALRM to interrupt us */
+ n = read(read_fd, &buf, 1);
alarm(0);
-
if (n == 1)
- return buf[0] & 0xff;
- else
- return -1;
+ return buf;
+ return -1;
}
-static int receive(char *error_buf, size_t error_buf_size,
- int ttyfd, int filefd)
+static int receive(/*int read_fd, */int file_fd)
{
- char blockBuf[1024];
- unsigned int errors = 0;
- unsigned int wantBlockNo = 1;
- unsigned int length = 0;
- int docrc = 1;
- char nak = 'C';
- unsigned int timeout = TIMEOUT_LONG;
-
-#define note_error(fmt,args...) \
- snprintf(error_buf, error_buf_size, fmt,##args)
+ unsigned char blockBuf[1024];
+ unsigned blockLength = 0;
+ unsigned errors = 0;
+ unsigned wantBlockNo = 1;
+ unsigned length = 0;
+ int do_crc = 1;
+ char reply_char;
+ unsigned timeout = TIMEOUT_LONG;
/* Flush pending input */
- tcflush(ttyfd, TCIFLUSH);
+ tcflush(read_fd, TCIFLUSH);
/* Ask for CRC; if we get errors, we will go with checksum */
- write(ttyfd, &nak, 1);
+ reply_char = 'C';
+ full_write(write_fd, &reply_char, 1);
for (;;) {
int blockBegin;
int blockNo, blockNoOnesCompl;
- int blockLength;
- int cksum = 0;
- int crcHi = 0;
- int crcLo = 0;
+ int cksum_or_crc;
+ int expected;
+ int i, j;
- blockBegin = read_byte(ttyfd, timeout);
+ 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;
- write(ttyfd, &nak, 1);
- goto done;
-
+ reply_char = ACK;
+ full_write(write_fd, &reply_char, 1);
+ return length;
default:
goto error;
}
- /* block no */
- blockNo = read_byte(ttyfd, TIMEOUT);
+ /* Block no */
+ blockNo = read_byte(TIMEOUT);
if (blockNo < 0)
goto timeout;
- /* block no one's compliment */
- blockNoOnesCompl = read_byte(ttyfd, TIMEOUT);
+ /* Block no, in one's complement form */
+ blockNoOnesCompl = read_byte(TIMEOUT);
if (blockNoOnesCompl < 0)
goto timeout;
if (blockNo != (255 - blockNoOnesCompl)) {
- note_error("bad block ones compl");
+ bb_error_msg("bad block ones compl");
goto error;
}
blockLength = (blockBegin == SOH) ? 128 : 1024;
- {
- int i;
-
- for (i = 0; i < blockLength; i++) {
- int cc = read_byte(ttyfd, TIMEOUT);
- if (cc < 0)
- goto timeout;
- blockBuf[i] = cc;
- }
- }
-
- if (docrc) {
- crcHi = read_byte(ttyfd, TIMEOUT);
- if (crcHi < 0)
+ for (i = 0; i < blockLength; i++) {
+ int cc = read_byte(TIMEOUT);
+ if (cc < 0)
goto timeout;
+ blockBuf[i] = cc;
+ }
- crcLo = read_byte(ttyfd, TIMEOUT);
- if (crcLo < 0)
- goto timeout;
- } else {
- cksum = read_byte(ttyfd, TIMEOUT);
- if (cksum < 0)
+ cksum_or_crc = read_byte(TIMEOUT);
+ if (cksum_or_crc < 0)
+ goto timeout;
+ if (do_crc) {
+ 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;
- } else if (blockNo != (wantBlockNo & 0xff)) {
- note_error("unexpected block no, 0x%08x, expecting 0x%08x", blockNo, wantBlockNo);
+ }
+ if (blockNo != (wantBlockNo & 0xff)) {
+ bb_error_msg("unexpected block no, 0x%08x, expecting 0x%08x", blockNo, wantBlockNo);
goto error;
}
- if (docrc) {
- int crc = 0;
- int i, j;
- int expectedCrcHi;
- int expectedCrcLo;
-
+ expected = 0;
+ if (do_crc) {
for (i = 0; i < blockLength; i++) {
- crc = crc ^ (int) blockBuf[i] << 8;
- for (j = 0; j < 8; j++)
- if (crc & 0x8000)
- crc = crc << 1 ^ 0x1021;
+ expected = expected ^ blockBuf[i] << 8;
+ for (j = 0; j < 8; j++) {
+ if (expected & 0x8000)
+ expected = (expected << 1) ^ 0x1021;
else
- crc = crc << 1;
- }
-
- expectedCrcHi = (crc >> 8) & 0xff;
- expectedCrcLo = crc & 0xff;
-
- if ((crcHi != expectedCrcHi) ||
- (crcLo != expectedCrcLo)) {
- note_error("crc error, expected 0x%02x 0x%02x, got 0x%02x 0x%02x", expectedCrcHi, expectedCrcLo, crcHi, crcLo);
- goto error;
+ expected = (expected << 1);
+ }
}
+ expected &= 0xffff;
} else {
- unsigned char expectedCksum = 0;
- int i;
-
for (i = 0; i < blockLength; i++)
- expectedCksum += blockBuf[i];
-
- if (cksum != expectedCksum) {
- note_error("checksum error, expected 0x%02x, got 0x%02x", expectedCksum, cksum);
- goto error;
- }
+ expected += blockBuf[i];
+ expected &= 0xff;
+ }
+ 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_or_crc);
+ goto error;
}
wantBlockNo++;
length += blockLength;
-
- if (full_write(filefd, blockBuf, blockLength) < 0) {
- note_error("write to file failed: %m");
- goto fatal;
- }
-
- next:
+ next:
errors = 0;
- nak = ACK;
- write(ttyfd, &nak, 1);
+ reply_char = ACK;
+ full_write(write_fd, &reply_char, 1);
continue;
-
- error:
- timeout:
+ error:
+ timeout:
+ blockLength = 0;
errors++;
if (errors == MAXERRORS) {
/* Abort */
- // if using 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;
- docrc = 0;
+ do_crc = 0;
goto timeout;
}
-
- note_error("too many errors; giving up");
-
- fatal:
- /* 5 CAN followed by 5 BS */
- write(ttyfd, "\030\030\030\030\030\010\010\010\010\010", 10);
+ bb_error_msg("too many errors; giving up");
+ fatal:
+ /* 5 CAN followed by 5 BS. Don't try too hard... */
+ safe_write(write_fd, "\030\030\030\030\030\010\010\010\010\010", 10);
return -1;
}
/* Flush pending input */
- tcflush(ttyfd, TCIFLUSH);
+ tcflush(read_fd, TCIFLUSH);
- write(ttyfd, &nak, 1);
- }
-
- done:
- return length;
-
-#undef note_error
+ full_write(write_fd, &reply_char, 1);
+ } /* for (;;) */
}
-static void sigalrm_handler(int ATTRIBUTE_UNUSED signum)
+static void sigalrm_handler(int UNUSED_PARAM signum)
{
}
-int rx_main(int argc, char **argv)
+int rx_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int rx_main(int argc UNUSED_PARAM, char **argv)
{
- char *fn;
- int ttyfd, filefd;
struct termios tty, orig_tty;
- struct sigaction act;
+ int termios_err;
+ int file_fd;
int n;
- char error_buf[256];
-
- if (argc != 2)
- bb_show_usage();
- fn = argv[1];
- ttyfd = xopen(CURRENT_TTY, O_RDWR);
- filefd = xopen(fn, O_RDWR|O_CREAT|O_TRUNC);
-
- if (tcgetattr(ttyfd, &tty) < 0)
- bb_perror_msg_and_die("tcgetattr");
-
- orig_tty = tty;
-
- cfmakeraw(&tty);
- tcsetattr(ttyfd, TCSAFLUSH, &tty);
-
- memset(&act, 0, sizeof(act));
- act.sa_handler = sigalrm_handler;
- sigaction(SIGALRM, &act, 0);
-
- n = receive(error_buf, sizeof(error_buf), ttyfd, filefd);
-
- close(filefd);
+ /* 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(single_argv(argv), O_RDWR|O_CREAT|O_TRUNC);
+
+ termios_err = tcgetattr(read_fd, &tty);
+ if (termios_err == 0) {
+ orig_tty = tty;
+ cfmakeraw(&tty);
+ tcsetattr(read_fd, TCSAFLUSH, &tty);
+ }
- tcsetattr(ttyfd, TCSAFLUSH, &orig_tty);
+ /* No SA_RESTART: we want ALRM to interrupt read() */
+ signal_no_SA_RESTART_empty_mask(SIGALRM, sigalrm_handler);
- if (n < 0)
- bb_error_msg_and_die("\nreceive failed:\n %s", error_buf);
+ n = receive(file_fd);
- fflush_stdout_and_exit(EXIT_SUCCESS);
+ if (termios_err == 0)
+ tcsetattr(read_fd, TCSAFLUSH, &orig_tty);
+ if (ENABLE_FEATURE_CLEAN_UP)
+ close(file_fd);
+ fflush_stdout_and_exit(n >= 0);
}