source: MondoRescue/branches/stable/mindi-busybox/miscutils/rx.c@ 821

Last change on this file since 821 was 821, checked in by Bruno Cornec, 18 years ago

Addition of busybox 1.2.1 as a mindi-busybox new package
This should avoid delivering binary files in mindi not built there (Fedora and Debian are quite serious about that)
File size: 6.1 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*-------------------------------------------------------------------------
3 * Filename: xmodem.c
4 * Version: $Id: rx.c,v 1.2 2004/03/15 08:28:46 andersen 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#include <stdlib.h>
25#include <stdarg.h>
26#include <stdio.h>
27#include <unistd.h>
28#include <errno.h>
29#include <termios.h>
30#include <signal.h>
31#include <sys/types.h>
32#include <sys/stat.h>
33#include <fcntl.h>
34#include <string.h>
35
36
37#define SOH 0x01
38#define STX 0x02
39#define EOT 0x04
40#define ACK 0x06
41#define NAK 0x15
42#define BS 0x08
43
44/*
45
46Cf:
47
48 http://www.textfiles.com/apple/xmodem
49 http://www.phys.washington.edu/~belonis/xmodem/docxmodem.txt
50 http://www.phys.washington.edu/~belonis/xmodem/docymodem.txt
51 http://www.phys.washington.edu/~belonis/xmodem/modmprot.col
52
53*/
54
55#define TIMEOUT 1
56#define TIMEOUT_LONG 10
57#define MAXERRORS 10
58
59static int read_byte(int fd, unsigned int timeout) {
60 char buf[1];
61 int n;
62
63 alarm(timeout);
64
65 n = read(fd, &buf, 1);
66
67 alarm(0);
68
69 if (n == 1)
70 return buf[0] & 0xff;
71 else
72 return -1;
73}
74
75static int receive(char *error_buf, size_t error_buf_size,
76 int ttyfd, int filefd)
77{
78 char blockBuf[1024];
79 unsigned int errors = 0;
80 unsigned int wantBlockNo = 1;
81 unsigned int length = 0;
82 int docrc = 1;
83 char nak = 'C';
84 unsigned int timeout = TIMEOUT_LONG;
85
86#define note_error(fmt,args...) \
87 snprintf(error_buf, error_buf_size, fmt,##args)
88
89 /* Flush pending input */
90 tcflush(ttyfd, TCIFLUSH);
91
92 /* Ask for CRC; if we get errors, we will go with checksum */
93 write(ttyfd, &nak, 1);
94
95 for (;;) {
96 int blockBegin;
97 int blockNo, blockNoOnesCompl;
98 int blockLength;
99 int cksum = 0;
100 int crcHi = 0;
101 int crcLo = 0;
102
103 blockBegin = read_byte(ttyfd, timeout);
104 if (blockBegin < 0)
105 goto timeout;
106
107 timeout = TIMEOUT;
108 nak = NAK;
109
110 switch (blockBegin) {
111 case SOH:
112 case STX:
113 break;
114
115 case EOT:
116 nak = ACK;
117 write(ttyfd, &nak, 1);
118 goto done;
119
120 default:
121 goto error;
122 }
123
124 /* block no */
125 blockNo = read_byte(ttyfd, TIMEOUT);
126 if (blockNo < 0)
127 goto timeout;
128
129 /* block no one's compliment */
130 blockNoOnesCompl = read_byte(ttyfd, TIMEOUT);
131 if (blockNoOnesCompl < 0)
132 goto timeout;
133
134 if (blockNo != (255 - blockNoOnesCompl)) {
135 note_error("bad block ones compl");
136 goto error;
137 }
138
139 blockLength = (blockBegin == SOH) ? 128 : 1024;
140
141 {
142 int i;
143
144 for (i = 0; i < blockLength; i++) {
145 int cc = read_byte(ttyfd, TIMEOUT);
146 if (cc < 0)
147 goto timeout;
148 blockBuf[i] = cc;
149 }
150 }
151
152 if (docrc) {
153 crcHi = read_byte(ttyfd, TIMEOUT);
154 if (crcHi < 0)
155 goto timeout;
156
157 crcLo = read_byte(ttyfd, TIMEOUT);
158 if (crcLo < 0)
159 goto timeout;
160 } else {
161 cksum = read_byte(ttyfd, TIMEOUT);
162 if (cksum < 0)
163 goto timeout;
164 }
165
166 if (blockNo == ((wantBlockNo - 1) & 0xff)) {
167 /* a repeat of the last block is ok, just ignore it. */
168 /* this also ignores the initial block 0 which is */
169 /* meta data. */
170 goto next;
171 } else if (blockNo != (wantBlockNo & 0xff)) {
172 note_error("unexpected block no, 0x%08x, expecting 0x%08x", blockNo, wantBlockNo);
173 goto error;
174 }
175
176 if (docrc) {
177 int crc = 0;
178 int i, j;
179 int expectedCrcHi;
180 int expectedCrcLo;
181
182 for (i = 0; i < blockLength; i++) {
183 crc = crc ^ (int) blockBuf[i] << 8;
184 for (j = 0; j < 8; j++)
185 if (crc & 0x8000)
186 crc = crc << 1 ^ 0x1021;
187 else
188 crc = crc << 1;
189 }
190
191 expectedCrcHi = (crc >> 8) & 0xff;
192 expectedCrcLo = crc & 0xff;
193
194 if ((crcHi != expectedCrcHi) ||
195 (crcLo != expectedCrcLo)) {
196 note_error("crc error, expected 0x%02x 0x%02x, got 0x%02x 0x%02x", expectedCrcHi, expectedCrcLo, crcHi, crcLo);
197 goto error;
198 }
199 } else {
200 unsigned char expectedCksum = 0;
201 int i;
202
203 for (i = 0; i < blockLength; i++)
204 expectedCksum += blockBuf[i];
205
206 if (cksum != expectedCksum) {
207 note_error("checksum error, expected 0x%02x, got 0x%02x", expectedCksum, cksum);
208 goto error;
209 }
210 }
211
212 wantBlockNo++;
213 length += blockLength;
214
215 if (bb_full_write(filefd, blockBuf, blockLength) < 0) {
216 note_error("write to file failed: %m");
217 goto fatal;
218 }
219
220 next:
221 errors = 0;
222 nak = ACK;
223 write(ttyfd, &nak, 1);
224 continue;
225
226 error:
227 timeout:
228 errors++;
229 if (errors == MAXERRORS) {
230 /* Abort */
231
232 // if using crc, try again w/o crc
233 if (nak == 'C') {
234 nak = NAK;
235 errors = 0;
236 docrc = 0;
237 goto timeout;
238 }
239
240 note_error("too many errors; giving up");
241
242 fatal:
243 /* 5 CAN followed by 5 BS */
244 write(ttyfd, "\030\030\030\030\030\010\010\010\010\010", 10);
245 return -1;
246 }
247
248 /* Flush pending input */
249 tcflush(ttyfd, TCIFLUSH);
250
251 write(ttyfd, &nak, 1);
252 }
253
254 done:
255 return length;
256
257#undef note_error
258}
259
260static void sigalrm_handler(int ATTRIBUTE_UNUSED signum)
261{
262}
263
264int rx_main(int argc, char **argv)
265{
266 char *fn;
267 int ttyfd, filefd;
268 struct termios tty, orig_tty;
269 struct sigaction act;
270 int n;
271 char error_buf[256];
272
273 if (argc != 2)
274 bb_show_usage();
275
276 fn = argv[1];
277 ttyfd = bb_xopen3(CURRENT_TTY, O_RDWR, 0);
278 filefd = bb_xopen3(fn, O_RDWR|O_CREAT|O_TRUNC, 0666);
279
280 if (tcgetattr(ttyfd, &tty) < 0)
281 bb_error_msg_and_die("%s: tcgetattr failed: %m\n", argv[0]);
282
283 orig_tty = tty;
284
285 cfmakeraw(&tty);
286 tcsetattr(ttyfd, TCSAFLUSH, &tty);
287
288 memset(&act, 0, sizeof(act));
289 act.sa_handler = sigalrm_handler;
290 sigaction(SIGALRM, &act, 0);
291
292 n = receive(error_buf, sizeof(error_buf), ttyfd, filefd);
293
294 close(filefd);
295
296 tcsetattr(ttyfd, TCSAFLUSH, &orig_tty);
297
298 if (n < 0)
299 bb_error_msg_and_die("\n%s: receive failed:\n %s\n",
300 argv[0], error_buf);
301
302 bb_fflush_stdout_and_exit(EXIT_SUCCESS);
303}
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