New applet, rx, by Christopher Hoover

3 files changed, 351 insertions, 0 deletions

diff --git a/miscutils/Config.in b/miscutils/Config.in
index 4216b2845..c5327c201 100644
--- a/miscutils/Config.in
+++ b/miscutils/Config.in
@@ -156,6 +156,12 @@ config CONFIG_MT
 	  to advance or rewind a tape past a specified number of archive
 	  files on the tape.
 
+config CONFIG_RX
+        bool "rx"
+	default n
+	help
+ 	  Receive files using the Xmodem protocol.
+
 config CONFIG_STRINGS
 	bool "strings"
 	default n
diff --git a/miscutils/Makefile.in b/miscutils/Makefile.in
index 773f55890..fea9b8926 100644
--- a/miscutils/Makefile.in
+++ b/miscutils/Makefile.in
@@ -33,6 +33,7 @@ MISCUTILS-$(CONFIG_HDPARM)		+= hdparm.o
 MISCUTILS-$(CONFIG_LAST)		+= last.o
 MISCUTILS-$(CONFIG_MAKEDEVS)		+= makedevs.o
 MISCUTILS-$(CONFIG_MT)			+= mt.o
+MISCUTILS-$(CONFIG_RX)			+= rx.o
 MISCUTILS-$(CONFIG_STRINGS)		+= strings.o
 MISCUTILS-$(CONFIG_TIME)		+= time.o
 MISCUTILS-$(CONFIG_WATCHDOG)		+= watchdog.o
diff --git a/miscutils/rx.c b/miscutils/rx.c
new file mode 100644
index 000000000..2b16f2e22
--- /dev/null
+++ b/miscutils/rx.c
@@ -0,0 +1,344 @@
+/*-------------------------------------------------------------------------
+ * Filename:      xmodem.c
+ * Version:       $Id: rx.c,v 1.1 2003/12/20 07:30:35 bug1 Exp $
+ * 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
+ *
+ * Copyright (C) 2001 Hewlett-Packard Laboratories
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ *
+ * This was originally written for blob and then adapted for busybox.
+ *
+ */
+
+#include <stdlib.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <termios.h>
+#include <signal.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <string.h>
+#include "busybox.h"
+
+
+#define SOH 0x01
+#define STX 0x02
+#define EOT 0x04
+#define ACK 0x06
+#define NAK 0x15
+#define CAN 0x18
+#define BS  0x08
+
+/*
+
+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 inline void write_byte(int fd, char cc) { 
+	write(fd, &cc, 1);
+}
+
+static inline void write_flush(int fd) {
+	tcdrain(fd);
+}
+
+static inline void read_flush(int fd) {
+	tcflush(fd, TCIFLUSH);
+}
+  
+static int read_byte(int fd, unsigned int timeout) {
+	char buf[1];
+	int n;
+
+	alarm(timeout);
+
+	n = read(fd, &buf, 1);
+
+	alarm(0);
+
+	if (n == 1)
+		return buf[0] & 0xff;
+	else
+		return -1;
+}
+
+static int receive(char *error_buf, size_t error_buf_size,
+				   int ttyfd, int filefd)
+{
+	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)
+
+	read_flush(ttyfd);
+
+	/* Ask for CRC; if we get errors, we will go with checksum */
+	write_byte(ttyfd, nak);
+	write_flush(ttyfd);
+
+	for (;;) {
+		int blockBegin;
+		int blockNo, blockNoOnesCompl;
+		int blockLength;
+		int cksum = 0;
+		int crcHi = 0;
+		int crcLo = 0;
+
+		blockBegin = read_byte(ttyfd, timeout);
+		if (blockBegin < 0)
+			goto timeout;
+
+		timeout = TIMEOUT;
+		nak = NAK;
+
+		switch (blockBegin) {
+		case SOH:
+		case STX:
+			break;
+
+		case EOT:
+			write_byte(ttyfd, ACK);
+			write_flush(ttyfd);
+			goto done;
+
+		default:
+			goto error;
+		}
+
+		/* block no */
+		blockNo = read_byte(ttyfd, TIMEOUT);
+		if (blockNo < 0)
+			goto timeout;
+
+		/* block no one's compliment */
+		blockNoOnesCompl = read_byte(ttyfd, TIMEOUT);
+		if (blockNoOnesCompl < 0)
+			goto timeout;
+
+		if (blockNo != (255 - blockNoOnesCompl)) {
+			note_error("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)
+				goto timeout;
+
+			crcLo = read_byte(ttyfd, TIMEOUT);
+			if (crcLo < 0)
+				goto timeout;
+		} else {
+			cksum = read_byte(ttyfd, TIMEOUT);
+			if (cksum < 0)
+				goto timeout;
+		}
+
+		if (blockNo == ((wantBlockNo - 1) & 0xff)) {
+			/* a repeat of the last block is ok, just ignore it. */
+			/* this also ignores the initial block 0 which is */
+			/* meta data. */
+			goto next;
+		} else if (blockNo != (wantBlockNo & 0xff)) {
+			note_error("unexpected block no, 0x%08x, expecting 0x%08x", blockNo, wantBlockNo);
+			goto error;
+		}
+
+		if (docrc) {
+			int crc = 0;
+			int i, j;
+			int expectedCrcHi;
+			int expectedCrcLo;
+
+			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;
+					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;
+			}
+		} 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;
+			}
+		}
+
+		wantBlockNo++;
+		length += blockLength;
+
+		if (bb_full_write(filefd, blockBuf, blockLength) < 0) {
+			note_error("write to file failed: %m");
+			goto fatal;
+		}
+
+	next:
+		errors = 0;
+		write_byte(ttyfd, ACK);
+		write_flush(ttyfd);
+		continue;
+
+	error:
+	timeout:
+		errors++;
+		if (errors == MAXERRORS) {
+			/* Abort */
+			int i;
+
+			// if using crc, try again w/o crc
+			if (nak == 'C') {
+				nak = NAK;
+				errors = 0;
+				docrc = 0;
+				goto timeout;
+			}
+
+			note_error("too many errors; giving up");
+
+		fatal:
+			for (i = 0; i < 5; i ++)
+				write_byte(ttyfd, CAN);
+			for (i = 0; i < 5; i ++)
+				write_byte(ttyfd, BS);
+			write_flush(ttyfd);
+			return -1;
+		}
+
+		read_flush(ttyfd);
+		write_byte(ttyfd, nak);
+		write_flush(ttyfd);
+	}
+
+ done:
+	return length;
+
+#undef note_error
+}
+
+static void sigalrm_handler(int signum)
+{
+}
+
+int rx_main(int argc, char **argv)
+{
+	char *fn;
+	int ttyfd, filefd;
+	struct termios tty, orig_tty;
+	struct sigaction act;
+	int n;
+	char error_buf[256];
+
+	if (argc != 2)
+			bb_show_usage();
+
+	fn = argv[1];
+	ttyfd = open("/dev/tty", O_RDWR);
+	if (ttyfd < 0)
+			bb_error_msg_and_die("%s: open on /dev/tty failed: %m\n", argv[0]);
+
+	filefd = open(fn, O_RDWR|O_CREAT|O_TRUNC, 0666);
+	if (filefd < 0)
+			bb_error_msg_and_die("%s: open on %s failed: %m\n", argv[0], fn);
+
+	if (tcgetattr(ttyfd, &tty) < 0)
+			bb_error_msg_and_die("%s: tcgetattr failed: %m\n", argv[0]);
+	
+	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);
+
+	tcsetattr(ttyfd, TCSAFLUSH, &orig_tty);
+
+	if (n < 0)
+			bb_error_msg_and_die("\n%s: receive failed:\n  %s\n",
+							   argv[0], error_buf);
+
+	bb_fflush_stdout_and_exit(EXIT_SUCCESS);
+}
+
+/*
+Local Variables:
+c-file-style: "linux"
+c-basic-offset: 4
+tab-width: 4
+End:
+*/