Glenn L McGrath | 8f3bc4c | 2003-12-20 07:30:35 +0000 | [diff] [blame] | 1 | /*------------------------------------------------------------------------- |
| 2 | * Filename: xmodem.c |
Eric Andersen | c7bda1c | 2004-03-15 08:29:22 +0000 | [diff] [blame^] | 3 | * Version: $Id: rx.c,v 1.2 2004/03/15 08:28:46 andersen Exp $ |
Glenn L McGrath | 8f3bc4c | 2003-12-20 07:30:35 +0000 | [diff] [blame] | 4 | * Copyright: Copyright (C) 2001, Hewlett-Packard Company |
| 5 | * Author: Christopher Hoover <ch@hpl.hp.com> |
Eric Andersen | c7bda1c | 2004-03-15 08:29:22 +0000 | [diff] [blame^] | 6 | * Description: xmodem functionality for uploading of kernels |
Glenn L McGrath | 8f3bc4c | 2003-12-20 07:30:35 +0000 | [diff] [blame] | 7 | * and the like |
| 8 | * Created at: Thu Dec 20 01:58:08 PST 2001 |
| 9 | *-----------------------------------------------------------------------*/ |
| 10 | /* |
Eric Andersen | c7bda1c | 2004-03-15 08:29:22 +0000 | [diff] [blame^] | 11 | * xmodem.c: xmodem functionality for uploading of kernels and |
Glenn L McGrath | 8f3bc4c | 2003-12-20 07:30:35 +0000 | [diff] [blame] | 12 | * the like |
| 13 | * |
| 14 | * Copyright (C) 2001 Hewlett-Packard Laboratories |
| 15 | * |
| 16 | * This program is free software; you can redistribute it and/or modify |
| 17 | * it under the terms of the GNU General Public License as published by |
| 18 | * the Free Software Foundation; either version 2 of the License, or |
| 19 | * (at your option) any later version. |
| 20 | * |
| 21 | * This program is distributed in the hope that it will be useful, |
| 22 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 23 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 24 | * GNU General Public License for more details. |
| 25 | * |
| 26 | * You should have received a copy of the GNU General Public License |
| 27 | * along with this program; if not, write to the Free Software |
| 28 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 29 | * |
| 30 | * |
| 31 | * This was originally written for blob and then adapted for busybox. |
| 32 | * |
| 33 | */ |
| 34 | |
| 35 | #include <stdlib.h> |
| 36 | #include <stdarg.h> |
| 37 | #include <stdio.h> |
| 38 | #include <unistd.h> |
| 39 | #include <errno.h> |
| 40 | #include <termios.h> |
| 41 | #include <signal.h> |
| 42 | #include <sys/types.h> |
| 43 | #include <sys/stat.h> |
| 44 | #include <fcntl.h> |
| 45 | #include <string.h> |
| 46 | #include "busybox.h" |
| 47 | |
| 48 | |
| 49 | #define SOH 0x01 |
| 50 | #define STX 0x02 |
| 51 | #define EOT 0x04 |
| 52 | #define ACK 0x06 |
| 53 | #define NAK 0x15 |
| 54 | #define CAN 0x18 |
| 55 | #define BS 0x08 |
| 56 | |
| 57 | /* |
| 58 | |
| 59 | Cf: |
| 60 | |
| 61 | http://www.textfiles.com/apple/xmodem |
| 62 | http://www.phys.washington.edu/~belonis/xmodem/docxmodem.txt |
| 63 | http://www.phys.washington.edu/~belonis/xmodem/docymodem.txt |
| 64 | http://www.phys.washington.edu/~belonis/xmodem/modmprot.col |
| 65 | |
| 66 | */ |
| 67 | |
| 68 | #define TIMEOUT 1 |
| 69 | #define TIMEOUT_LONG 10 |
| 70 | #define MAXERRORS 10 |
| 71 | |
Eric Andersen | c7bda1c | 2004-03-15 08:29:22 +0000 | [diff] [blame^] | 72 | static inline void write_byte(int fd, char cc) { |
Glenn L McGrath | 8f3bc4c | 2003-12-20 07:30:35 +0000 | [diff] [blame] | 73 | write(fd, &cc, 1); |
| 74 | } |
| 75 | |
| 76 | static inline void write_flush(int fd) { |
| 77 | tcdrain(fd); |
| 78 | } |
| 79 | |
| 80 | static inline void read_flush(int fd) { |
| 81 | tcflush(fd, TCIFLUSH); |
| 82 | } |
Eric Andersen | c7bda1c | 2004-03-15 08:29:22 +0000 | [diff] [blame^] | 83 | |
Glenn L McGrath | 8f3bc4c | 2003-12-20 07:30:35 +0000 | [diff] [blame] | 84 | static int read_byte(int fd, unsigned int timeout) { |
| 85 | char buf[1]; |
| 86 | int n; |
| 87 | |
| 88 | alarm(timeout); |
| 89 | |
| 90 | n = read(fd, &buf, 1); |
| 91 | |
| 92 | alarm(0); |
| 93 | |
| 94 | if (n == 1) |
| 95 | return buf[0] & 0xff; |
| 96 | else |
| 97 | return -1; |
| 98 | } |
| 99 | |
| 100 | static int receive(char *error_buf, size_t error_buf_size, |
| 101 | int ttyfd, int filefd) |
| 102 | { |
| 103 | char blockBuf[1024]; |
| 104 | unsigned int errors = 0; |
| 105 | unsigned int wantBlockNo = 1; |
| 106 | unsigned int length = 0; |
| 107 | int docrc = 1; |
| 108 | char nak = 'C'; |
| 109 | unsigned int timeout = TIMEOUT_LONG; |
| 110 | |
| 111 | #define note_error(fmt,args...) \ |
| 112 | snprintf(error_buf, error_buf_size, fmt,##args) |
| 113 | |
| 114 | read_flush(ttyfd); |
| 115 | |
| 116 | /* Ask for CRC; if we get errors, we will go with checksum */ |
| 117 | write_byte(ttyfd, nak); |
| 118 | write_flush(ttyfd); |
| 119 | |
| 120 | for (;;) { |
| 121 | int blockBegin; |
| 122 | int blockNo, blockNoOnesCompl; |
| 123 | int blockLength; |
| 124 | int cksum = 0; |
| 125 | int crcHi = 0; |
| 126 | int crcLo = 0; |
| 127 | |
| 128 | blockBegin = read_byte(ttyfd, timeout); |
| 129 | if (blockBegin < 0) |
| 130 | goto timeout; |
| 131 | |
| 132 | timeout = TIMEOUT; |
| 133 | nak = NAK; |
| 134 | |
| 135 | switch (blockBegin) { |
| 136 | case SOH: |
| 137 | case STX: |
| 138 | break; |
| 139 | |
| 140 | case EOT: |
| 141 | write_byte(ttyfd, ACK); |
| 142 | write_flush(ttyfd); |
| 143 | goto done; |
| 144 | |
| 145 | default: |
| 146 | goto error; |
| 147 | } |
| 148 | |
| 149 | /* block no */ |
| 150 | blockNo = read_byte(ttyfd, TIMEOUT); |
| 151 | if (blockNo < 0) |
| 152 | goto timeout; |
| 153 | |
| 154 | /* block no one's compliment */ |
| 155 | blockNoOnesCompl = read_byte(ttyfd, TIMEOUT); |
| 156 | if (blockNoOnesCompl < 0) |
| 157 | goto timeout; |
| 158 | |
| 159 | if (blockNo != (255 - blockNoOnesCompl)) { |
| 160 | note_error("bad block ones compl"); |
| 161 | goto error; |
| 162 | } |
| 163 | |
| 164 | blockLength = (blockBegin == SOH) ? 128 : 1024; |
| 165 | |
| 166 | { |
| 167 | int i; |
| 168 | |
| 169 | for (i = 0; i < blockLength; i++) { |
| 170 | int cc = read_byte(ttyfd, TIMEOUT); |
| 171 | if (cc < 0) |
| 172 | goto timeout; |
| 173 | blockBuf[i] = cc; |
| 174 | } |
| 175 | } |
| 176 | |
| 177 | if (docrc) { |
| 178 | crcHi = read_byte(ttyfd, TIMEOUT); |
| 179 | if (crcHi < 0) |
| 180 | goto timeout; |
| 181 | |
| 182 | crcLo = read_byte(ttyfd, TIMEOUT); |
| 183 | if (crcLo < 0) |
| 184 | goto timeout; |
| 185 | } else { |
| 186 | cksum = read_byte(ttyfd, TIMEOUT); |
| 187 | if (cksum < 0) |
| 188 | goto timeout; |
| 189 | } |
| 190 | |
| 191 | if (blockNo == ((wantBlockNo - 1) & 0xff)) { |
| 192 | /* a repeat of the last block is ok, just ignore it. */ |
| 193 | /* this also ignores the initial block 0 which is */ |
| 194 | /* meta data. */ |
| 195 | goto next; |
| 196 | } else if (blockNo != (wantBlockNo & 0xff)) { |
| 197 | note_error("unexpected block no, 0x%08x, expecting 0x%08x", blockNo, wantBlockNo); |
| 198 | goto error; |
| 199 | } |
| 200 | |
| 201 | if (docrc) { |
| 202 | int crc = 0; |
| 203 | int i, j; |
| 204 | int expectedCrcHi; |
| 205 | int expectedCrcLo; |
| 206 | |
| 207 | for (i = 0; i < blockLength; i++) { |
| 208 | crc = crc ^ (int) blockBuf[i] << 8; |
| 209 | for (j = 0; j < 8; j++) |
| 210 | if (crc & 0x8000) |
| 211 | crc = crc << 1 ^ 0x1021; |
| 212 | else |
| 213 | crc = crc << 1; |
| 214 | } |
| 215 | |
| 216 | expectedCrcHi = (crc >> 8) & 0xff; |
| 217 | expectedCrcLo = crc & 0xff; |
| 218 | |
| 219 | if ((crcHi != expectedCrcHi) || |
| 220 | (crcLo != expectedCrcLo)) { |
| 221 | note_error("crc error, expected 0x%02x 0x%02x, got 0x%02x 0x%02x", expectedCrcHi, expectedCrcLo, crcHi, crcLo); |
| 222 | goto error; |
| 223 | } |
| 224 | } else { |
| 225 | unsigned char expectedCksum = 0; |
| 226 | int i; |
| 227 | |
| 228 | for (i = 0; i < blockLength; i++) |
| 229 | expectedCksum += blockBuf[i]; |
| 230 | |
| 231 | if (cksum != expectedCksum) { |
| 232 | note_error("checksum error, expected 0x%02x, got 0x%02x", expectedCksum, cksum); |
| 233 | goto error; |
| 234 | } |
| 235 | } |
| 236 | |
| 237 | wantBlockNo++; |
| 238 | length += blockLength; |
| 239 | |
| 240 | if (bb_full_write(filefd, blockBuf, blockLength) < 0) { |
| 241 | note_error("write to file failed: %m"); |
| 242 | goto fatal; |
| 243 | } |
| 244 | |
| 245 | next: |
| 246 | errors = 0; |
| 247 | write_byte(ttyfd, ACK); |
| 248 | write_flush(ttyfd); |
| 249 | continue; |
| 250 | |
| 251 | error: |
| 252 | timeout: |
| 253 | errors++; |
| 254 | if (errors == MAXERRORS) { |
| 255 | /* Abort */ |
| 256 | int i; |
| 257 | |
| 258 | // if using crc, try again w/o crc |
| 259 | if (nak == 'C') { |
| 260 | nak = NAK; |
| 261 | errors = 0; |
| 262 | docrc = 0; |
| 263 | goto timeout; |
| 264 | } |
| 265 | |
| 266 | note_error("too many errors; giving up"); |
| 267 | |
| 268 | fatal: |
| 269 | for (i = 0; i < 5; i ++) |
| 270 | write_byte(ttyfd, CAN); |
| 271 | for (i = 0; i < 5; i ++) |
| 272 | write_byte(ttyfd, BS); |
| 273 | write_flush(ttyfd); |
| 274 | return -1; |
| 275 | } |
| 276 | |
| 277 | read_flush(ttyfd); |
| 278 | write_byte(ttyfd, nak); |
| 279 | write_flush(ttyfd); |
| 280 | } |
| 281 | |
| 282 | done: |
| 283 | return length; |
| 284 | |
| 285 | #undef note_error |
| 286 | } |
| 287 | |
| 288 | static void sigalrm_handler(int signum) |
| 289 | { |
| 290 | } |
| 291 | |
| 292 | int rx_main(int argc, char **argv) |
| 293 | { |
| 294 | char *fn; |
| 295 | int ttyfd, filefd; |
| 296 | struct termios tty, orig_tty; |
| 297 | struct sigaction act; |
| 298 | int n; |
| 299 | char error_buf[256]; |
| 300 | |
| 301 | if (argc != 2) |
| 302 | bb_show_usage(); |
| 303 | |
| 304 | fn = argv[1]; |
| 305 | ttyfd = open("/dev/tty", O_RDWR); |
| 306 | if (ttyfd < 0) |
| 307 | bb_error_msg_and_die("%s: open on /dev/tty failed: %m\n", argv[0]); |
| 308 | |
| 309 | filefd = open(fn, O_RDWR|O_CREAT|O_TRUNC, 0666); |
| 310 | if (filefd < 0) |
| 311 | bb_error_msg_and_die("%s: open on %s failed: %m\n", argv[0], fn); |
| 312 | |
| 313 | if (tcgetattr(ttyfd, &tty) < 0) |
| 314 | bb_error_msg_and_die("%s: tcgetattr failed: %m\n", argv[0]); |
Eric Andersen | c7bda1c | 2004-03-15 08:29:22 +0000 | [diff] [blame^] | 315 | |
Glenn L McGrath | 8f3bc4c | 2003-12-20 07:30:35 +0000 | [diff] [blame] | 316 | orig_tty = tty; |
| 317 | |
| 318 | cfmakeraw(&tty); |
| 319 | tcsetattr(ttyfd, TCSAFLUSH, &tty); |
Eric Andersen | c7bda1c | 2004-03-15 08:29:22 +0000 | [diff] [blame^] | 320 | |
Glenn L McGrath | 8f3bc4c | 2003-12-20 07:30:35 +0000 | [diff] [blame] | 321 | memset(&act, 0, sizeof(act)); |
| 322 | act.sa_handler = sigalrm_handler; |
| 323 | sigaction(SIGALRM, &act, 0); |
| 324 | |
| 325 | n = receive(error_buf, sizeof(error_buf), ttyfd, filefd); |
| 326 | |
| 327 | close(filefd); |
| 328 | |
| 329 | tcsetattr(ttyfd, TCSAFLUSH, &orig_tty); |
| 330 | |
| 331 | if (n < 0) |
| 332 | bb_error_msg_and_die("\n%s: receive failed:\n %s\n", |
| 333 | argv[0], error_buf); |
| 334 | |
| 335 | bb_fflush_stdout_and_exit(EXIT_SUCCESS); |
| 336 | } |
| 337 | |
| 338 | /* |
| 339 | Local Variables: |
| 340 | c-file-style: "linux" |
| 341 | c-basic-offset: 4 |
| 342 | tab-width: 4 |
| 343 | End: |
| 344 | */ |