1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
|
/* vi: set sw=4 ts=4: */
/*-------------------------------------------------------------------------
* Filename: xmodem.c
* Version: $Id: rx.c,v 1.2 2004/03/15 08:28:46 andersen 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 <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 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 = bb_xopen3("/dev/tty", O_RDWR, 0);
filefd = bb_xopen3(fn, O_RDWR|O_CREAT|O_TRUNC, 0666);
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);
}
|