busybox/miscutils/rx.c

/* vi: set sw=4 ts=4: */
/*-------------------------------------------------------------------------
 * Filename:      xmodem.c
 * Version:       $Id: rx.c,v 1.1 2007-09-01 22:43:52 niro 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
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 *
 * This was originally written for blob and then adapted for busybox.
 *
 */

#include "busybox.h"

#define SOH 0x01
#define STX 0x02
#define EOT 0x04
#define ACK 0x06
#define NAK 0x15
#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 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)

	/* Flush pending input */
	tcflush(ttyfd, TCIFLUSH);

	/* Ask for CRC; if we get errors, we will go with checksum */
	write(ttyfd, &nak, 1);

	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:
			nak = ACK;
			write(ttyfd, &nak, 1);
			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 (full_write(filefd, blockBuf, blockLength) < 0) {
			note_error("write to file failed: %m");
			goto fatal;
		}

	next:
		errors = 0;
		nak = ACK;
		write(ttyfd, &nak, 1);
		continue;

	error:
	timeout:
		errors++;
		if (errors == MAXERRORS) {
			/* Abort */

			// 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:
			/* 5 CAN followed by 5 BS */
			write(ttyfd, "\030\030\030\030\030\010\010\010\010\010", 10);
			return -1;
		}

		/* Flush pending input */
		tcflush(ttyfd, TCIFLUSH);

		write(ttyfd, &nak, 1);
	}

 done:
	return length;

#undef note_error
}

static void sigalrm_handler(int ATTRIBUTE_UNUSED 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 = 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);

	tcsetattr(ttyfd, TCSAFLUSH, &orig_tty);

	if (n < 0)
		bb_error_msg_and_die("\nreceive failed:\n  %s", error_buf);

	fflush_stdout_and_exit(EXIT_SUCCESS);
}
1	/* vi: set sw=4 ts=4: */
2	/*-------------------------------------------------------------------------
3	* Filename: xmodem.c
4	* Version: $Id: rx.c,v 1.1 2007-09-01 22:43:52 niro Exp $
5	* Copyright: Copyright (C) 2001, Hewlett-Packard Company
6	* Author: Christopher Hoover <ch@hpl.hp.com>
7	* Description: xmodem functionality for uploading of kernels
8	* and the like
9	* Created at: Thu Dec 20 01:58:08 PST 2001
10	-----------------------------------------------------------------------/
11	/*
12	* xmodem.c: xmodem functionality for uploading of kernels and
13	* the like
14	*
15	* Copyright (C) 2001 Hewlett-Packard Laboratories
16	*
17	* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
18	*
19	* This was originally written for blob and then adapted for busybox.
20	*
21	*/
22
23	#include "busybox.h"
24
25	#define SOH 0x01
26	#define STX 0x02
27	#define EOT 0x04
28	#define ACK 0x06
29	#define NAK 0x15
30	#define BS 0x08
31
32	/*
33
34	Cf:
35
36	http://www.textfiles.com/apple/xmodem
37	http://www.phys.washington.edu/~belonis/xmodem/docxmodem.txt
38	http://www.phys.washington.edu/~belonis/xmodem/docymodem.txt
39	http://www.phys.washington.edu/~belonis/xmodem/modmprot.col
40
41	*/
42
43	#define TIMEOUT 1
44	#define TIMEOUT_LONG 10
45	#define MAXERRORS 10
46
47	static int read_byte(int fd, unsigned int timeout) {
48	char buf[1];
49	int n;
50
51	alarm(timeout);
52
53	n = read(fd, &buf, 1);
54
55	alarm(0);
56
57	if (n == 1)
58	return buf[0] & 0xff;
59	else
60	return -1;
61	}
62
63	static int receive(char *error_buf, size_t error_buf_size,
64	int ttyfd, int filefd)
65	{
66	char blockBuf[1024];
67	unsigned int errors = 0;
68	unsigned int wantBlockNo = 1;
69	unsigned int length = 0;
70	int docrc = 1;
71	char nak = 'C';
72	unsigned int timeout = TIMEOUT_LONG;
73
74	#define note_error(fmt,args...) \
75	snprintf(error_buf, error_buf_size, fmt,##args)
76
77	/* Flush pending input */
78	tcflush(ttyfd, TCIFLUSH);
79
80	/* Ask for CRC; if we get errors, we will go with checksum */
81	write(ttyfd, &nak, 1);
82
83	for (;;) {
84	int blockBegin;
85	int blockNo, blockNoOnesCompl;
86	int blockLength;
87	int cksum = 0;
88	int crcHi = 0;
89	int crcLo = 0;
90
91	blockBegin = read_byte(ttyfd, timeout);
92	if (blockBegin < 0)
93	goto timeout;
94
95	timeout = TIMEOUT;
96	nak = NAK;
97
98	switch (blockBegin) {
99	case SOH:
100	case STX:
101	break;
102
103	case EOT:
104	nak = ACK;
105	write(ttyfd, &nak, 1);
106	goto done;
107
108	default:
109	goto error;
110	}
111
112	/* block no */
113	blockNo = read_byte(ttyfd, TIMEOUT);
114	if (blockNo < 0)
115	goto timeout;
116
117	/* block no one's compliment */
118	blockNoOnesCompl = read_byte(ttyfd, TIMEOUT);
119	if (blockNoOnesCompl < 0)
120	goto timeout;
121
122	if (blockNo != (255 - blockNoOnesCompl)) {
123	note_error("bad block ones compl");
124	goto error;
125	}
126
127	blockLength = (blockBegin == SOH) ? 128 : 1024;
128
129	{
130	int i;
131
132	for (i = 0; i < blockLength; i++) {
133	int cc = read_byte(ttyfd, TIMEOUT);
134	if (cc < 0)
135	goto timeout;
136	blockBuf[i] = cc;
137	}
138	}
139
140	if (docrc) {
141	crcHi = read_byte(ttyfd, TIMEOUT);
142	if (crcHi < 0)
143	goto timeout;
144
145	crcLo = read_byte(ttyfd, TIMEOUT);
146	if (crcLo < 0)
147	goto timeout;
148	} else {
149	cksum = read_byte(ttyfd, TIMEOUT);
150	if (cksum < 0)
151	goto timeout;
152	}
153
154	if (blockNo == ((wantBlockNo - 1) & 0xff)) {
155	/* a repeat of the last block is ok, just ignore it. */
156	/* this also ignores the initial block 0 which is */
157	/* meta data. */
158	goto next;
159	} else if (blockNo != (wantBlockNo & 0xff)) {
160	note_error("unexpected block no, 0x%08x, expecting 0x%08x", blockNo, wantBlockNo);
161	goto error;
162	}
163
164	if (docrc) {
165	int crc = 0;
166	int i, j;
167	int expectedCrcHi;
168	int expectedCrcLo;
169
170	for (i = 0; i < blockLength; i++) {
171	crc = crc ^ (int) blockBuf[i] << 8;
172	for (j = 0; j < 8; j++)
173	if (crc & 0x8000)
174	crc = crc << 1 ^ 0x1021;
175	else
176	crc = crc << 1;
177	}
178
179	expectedCrcHi = (crc >> 8) & 0xff;
180	expectedCrcLo = crc & 0xff;
181
182	if ((crcHi != expectedCrcHi) \|\|
183	(crcLo != expectedCrcLo)) {
184	note_error("crc error, expected 0x%02x 0x%02x, got 0x%02x 0x%02x", expectedCrcHi, expectedCrcLo, crcHi, crcLo);
185	goto error;
186	}
187	} else {
188	unsigned char expectedCksum = 0;
189	int i;
190
191	for (i = 0; i < blockLength; i++)
192	expectedCksum += blockBuf[i];
193
194	if (cksum != expectedCksum) {
195	note_error("checksum error, expected 0x%02x, got 0x%02x", expectedCksum, cksum);
196	goto error;
197	}
198	}
199
200	wantBlockNo++;
201	length += blockLength;
202
203	if (full_write(filefd, blockBuf, blockLength) < 0) {
204	note_error("write to file failed: %m");
205	goto fatal;
206	}
207
208	next:
209	errors = 0;
210	nak = ACK;
211	write(ttyfd, &nak, 1);
212	continue;
213
214	error:
215	timeout:
216	errors++;
217	if (errors == MAXERRORS) {
218	/* Abort */
219
220	// if using crc, try again w/o crc
221	if (nak == 'C') {
222	nak = NAK;
223	errors = 0;
224	docrc = 0;
225	goto timeout;
226	}
227
228	note_error("too many errors; giving up");
229
230	fatal:
231	/* 5 CAN followed by 5 BS */
232	write(ttyfd, "\030\030\030\030\030\010\010\010\010\010", 10);
233	return -1;
234	}
235
236	/* Flush pending input */
237	tcflush(ttyfd, TCIFLUSH);
238
239	write(ttyfd, &nak, 1);
240	}
241
242	done:
243	return length;
244
245	#undef note_error
246	}
247
248	static void sigalrm_handler(int ATTRIBUTE_UNUSED signum)
249	{
250	}
251
252	int rx_main(int argc, char **argv)
253	{
254	char *fn;
255	int ttyfd, filefd;
256	struct termios tty, orig_tty;
257	struct sigaction act;
258	int n;
259	char error_buf[256];
260
261	if (argc != 2)
262	bb_show_usage();
263
264	fn = argv[1];
265	ttyfd = xopen(CURRENT_TTY, O_RDWR);
266	filefd = xopen(fn, O_RDWR\|O_CREAT\|O_TRUNC);
267
268	if (tcgetattr(ttyfd, &tty) < 0)
269	bb_perror_msg_and_die("tcgetattr");
270
271	orig_tty = tty;
272
273	cfmakeraw(&tty);
274	tcsetattr(ttyfd, TCSAFLUSH, &tty);
275
276	memset(&act, 0, sizeof(act));
277	act.sa_handler = sigalrm_handler;
278	sigaction(SIGALRM, &act, 0);
279
280	n = receive(error_buf, sizeof(error_buf), ttyfd, filefd);
281
282	close(filefd);
283
284	tcsetattr(ttyfd, TCSAFLUSH, &orig_tty);
285
286	if (n < 0)
287	bb_error_msg_and_die("\nreceive failed:\n %s", error_buf);
288
289	fflush_stdout_and_exit(EXIT_SUCCESS);
290	}