blob: 8ccea497438e8e67d73334b9370d901423b99943 [file] [log] [blame]
Bernhard Reutner-Fischerc2cb0f32006-04-13 12:45:04 +00001/* vi: set sw=4 ts=4: */
Glenn L McGrath8f3bc4c2003-12-20 07:30:35 +00002/*-------------------------------------------------------------------------
3 * Filename: xmodem.c
Glenn L McGrath8f3bc4c2003-12-20 07:30:35 +00004 * Copyright: Copyright (C) 2001, Hewlett-Packard Company
5 * Author: Christopher Hoover <ch@hpl.hp.com>
Eric Andersenc7bda1c2004-03-15 08:29:22 +00006 * Description: xmodem functionality for uploading of kernels
Glenn L McGrath8f3bc4c2003-12-20 07:30:35 +00007 * and the like
8 * Created at: Thu Dec 20 01:58:08 PST 2001
9 *-----------------------------------------------------------------------*/
10/*
Eric Andersenc7bda1c2004-03-15 08:29:22 +000011 * xmodem.c: xmodem functionality for uploading of kernels and
Glenn L McGrath8f3bc4c2003-12-20 07:30:35 +000012 * the like
13 *
14 * Copyright (C) 2001 Hewlett-Packard Laboratories
15 *
Bernhard Reutner-Fischer20f40002006-01-30 17:17:14 +000016 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
Glenn L McGrath8f3bc4c2003-12-20 07:30:35 +000017 *
18 * This was originally written for blob and then adapted for busybox.
19 *
20 */
21
Denis Vlasenkob6adbf12007-05-26 19:00:18 +000022#include "libbb.h"
Glenn L McGrath8f3bc4c2003-12-20 07:30:35 +000023
24#define SOH 0x01
25#define STX 0x02
26#define EOT 0x04
27#define ACK 0x06
28#define NAK 0x15
Glenn L McGrath8f3bc4c2003-12-20 07:30:35 +000029#define BS 0x08
30
31/*
32
33Cf:
34
35 http://www.textfiles.com/apple/xmodem
36 http://www.phys.washington.edu/~belonis/xmodem/docxmodem.txt
37 http://www.phys.washington.edu/~belonis/xmodem/docymodem.txt
38 http://www.phys.washington.edu/~belonis/xmodem/modmprot.col
39
40*/
41
42#define TIMEOUT 1
43#define TIMEOUT_LONG 10
44#define MAXERRORS 10
45
Denis Vlasenko400d8bb2008-02-24 13:36:01 +000046static int read_byte(int fd, unsigned timeout)
Denis Vlasenkoac678ec2007-04-16 22:32:04 +000047{
Glenn L McGrath8f3bc4c2003-12-20 07:30:35 +000048 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
63static 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
Rob Landley399d45f2006-06-21 01:49:17 +000077 /* Flush pending input */
78 tcflush(ttyfd, TCIFLUSH);
Glenn L McGrath8f3bc4c2003-12-20 07:30:35 +000079
80 /* Ask for CRC; if we get errors, we will go with checksum */
Rob Landley399d45f2006-06-21 01:49:17 +000081 write(ttyfd, &nak, 1);
Glenn L McGrath8f3bc4c2003-12-20 07:30:35 +000082
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:
Rob Landley399d45f2006-06-21 01:49:17 +0000104 nak = ACK;
105 write(ttyfd, &nak, 1);
Glenn L McGrath8f3bc4c2003-12-20 07:30:35 +0000106 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
Rob Landley53437472006-07-16 08:14:35 +0000203 if (full_write(filefd, blockBuf, blockLength) < 0) {
Glenn L McGrath8f3bc4c2003-12-20 07:30:35 +0000204 note_error("write to file failed: %m");
205 goto fatal;
206 }
207
208 next:
209 errors = 0;
Rob Landley399d45f2006-06-21 01:49:17 +0000210 nak = ACK;
211 write(ttyfd, &nak, 1);
Glenn L McGrath8f3bc4c2003-12-20 07:30:35 +0000212 continue;
213
214 error:
215 timeout:
216 errors++;
217 if (errors == MAXERRORS) {
218 /* Abort */
Glenn L McGrath8f3bc4c2003-12-20 07:30:35 +0000219
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:
Rob Landley399d45f2006-06-21 01:49:17 +0000231 /* 5 CAN followed by 5 BS */
232 write(ttyfd, "\030\030\030\030\030\010\010\010\010\010", 10);
Glenn L McGrath8f3bc4c2003-12-20 07:30:35 +0000233 return -1;
234 }
235
Rob Landley399d45f2006-06-21 01:49:17 +0000236 /* Flush pending input */
237 tcflush(ttyfd, TCIFLUSH);
238
239 write(ttyfd, &nak, 1);
Glenn L McGrath8f3bc4c2003-12-20 07:30:35 +0000240 }
241
242 done:
243 return length;
244
245#undef note_error
246}
247
Bernhard Reutner-Fischer20f40002006-01-30 17:17:14 +0000248static void sigalrm_handler(int ATTRIBUTE_UNUSED signum)
Glenn L McGrath8f3bc4c2003-12-20 07:30:35 +0000249{
250}
251
Denis Vlasenko9b49a5e2007-10-11 10:05:36 +0000252int rx_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
Glenn L McGrath8f3bc4c2003-12-20 07:30:35 +0000253int rx_main(int argc, char **argv)
254{
255 char *fn;
256 int ttyfd, filefd;
257 struct termios tty, orig_tty;
258 struct sigaction act;
259 int n;
260 char error_buf[256];
261
262 if (argc != 2)
263 bb_show_usage();
264
265 fn = argv[1];
Bernhard Reutner-Fischer64d7e932006-09-11 16:01:40 +0000266 ttyfd = xopen(CURRENT_TTY, O_RDWR);
Denis Vlasenkocf749bc2006-11-26 15:45:17 +0000267 filefd = xopen(fn, O_RDWR|O_CREAT|O_TRUNC);
Glenn L McGrath8f3bc4c2003-12-20 07:30:35 +0000268
269 if (tcgetattr(ttyfd, &tty) < 0)
Denis Vlasenko7d219aa2006-10-05 10:17:08 +0000270 bb_perror_msg_and_die("tcgetattr");
Eric Andersenc7bda1c2004-03-15 08:29:22 +0000271
Glenn L McGrath8f3bc4c2003-12-20 07:30:35 +0000272 orig_tty = tty;
273
274 cfmakeraw(&tty);
275 tcsetattr(ttyfd, TCSAFLUSH, &tty);
Eric Andersenc7bda1c2004-03-15 08:29:22 +0000276
Glenn L McGrath8f3bc4c2003-12-20 07:30:35 +0000277 memset(&act, 0, sizeof(act));
278 act.sa_handler = sigalrm_handler;
279 sigaction(SIGALRM, &act, 0);
280
281 n = receive(error_buf, sizeof(error_buf), ttyfd, filefd);
282
283 close(filefd);
284
285 tcsetattr(ttyfd, TCSAFLUSH, &orig_tty);
286
287 if (n < 0)
Denis Vlasenko7d219aa2006-10-05 10:17:08 +0000288 bb_error_msg_and_die("\nreceive failed:\n %s", error_buf);
Glenn L McGrath8f3bc4c2003-12-20 07:30:35 +0000289
Denis Vlasenkof0ed3762006-10-26 23:21:47 +0000290 fflush_stdout_and_exit(EXIT_SUCCESS);
Glenn L McGrath8f3bc4c2003-12-20 07:30:35 +0000291}