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 |
|
---|
46 | Cf:
|
---|
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 |
|
---|
59 | static 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 |
|
---|
75 | static 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 |
|
---|
260 | static void sigalrm_handler(int ATTRIBUTE_UNUSED signum)
|
---|
261 | {
|
---|
262 | }
|
---|
263 |
|
---|
264 | int 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 | }
|
---|