dd.c revision 1.32
1 /* $NetBSD: dd.c,v 1.32 2003/08/20 14:25:54 jschauma Exp $ */ 2 3 /*- 4 * Copyright (c) 1991, 1993, 1994 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Keith Muller of the University of California, San Diego and Lance 9 * Visser of Convex Computer Corporation. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #ifndef lint 38 __COPYRIGHT("@(#) Copyright (c) 1991, 1993, 1994\n\ 39 The Regents of the University of California. All rights reserved.\n"); 40 #endif /* not lint */ 41 42 #ifndef lint 43 #if 0 44 static char sccsid[] = "@(#)dd.c 8.5 (Berkeley) 4/2/94"; 45 #else 46 __RCSID("$NetBSD: dd.c,v 1.32 2003/08/20 14:25:54 jschauma Exp $"); 47 #endif 48 #endif /* not lint */ 49 50 #include <sys/param.h> 51 #include <sys/stat.h> 52 #include <sys/ioctl.h> 53 #include <sys/mtio.h> 54 #include <sys/time.h> 55 56 #include <ctype.h> 57 #include <err.h> 58 #include <errno.h> 59 #include <fcntl.h> 60 #include <signal.h> 61 #include <stdio.h> 62 #include <stdlib.h> 63 #include <string.h> 64 #include <unistd.h> 65 66 #include "dd.h" 67 #include "extern.h" 68 69 static void dd_close(void); 70 static void dd_in(void); 71 static void getfdtype(IO *); 72 static void setup(void); 73 74 int main(int, char *[]); 75 76 IO in, out; /* input/output state */ 77 STAT st; /* statistics */ 78 void (*cfunc)(void); /* conversion function */ 79 uint64_t cpy_cnt; /* # of blocks to copy */ 80 u_int ddflags; /* conversion options */ 81 uint64_t cbsz; /* conversion block size */ 82 u_int files_cnt = 1; /* # of files to copy */ 83 int progress = 0; /* display sign of life */ 84 const u_char *ctab; /* conversion table */ 85 sigset_t infoset; /* a set blocking SIGINFO */ 86 87 int 88 main(int argc, char *argv[]) 89 { 90 int ch; 91 92 while ((ch = getopt(argc, argv, "")) != -1) { 93 switch (ch) { 94 default: 95 errx(EXIT_FAILURE, "usage: dd [operand ...]"); 96 /* NOTREACHED */ 97 } 98 } 99 argc -= (optind - 1); 100 argv += (optind - 1); 101 102 jcl(argv); 103 setup(); 104 105 (void)signal(SIGINFO, summaryx); 106 (void)signal(SIGINT, terminate); 107 (void)sigemptyset(&infoset); 108 (void)sigaddset(&infoset, SIGINFO); 109 110 (void)atexit(summary); 111 112 while (files_cnt--) 113 dd_in(); 114 115 dd_close(); 116 exit(0); 117 /* NOTREACHED */ 118 } 119 120 static void 121 setup(void) 122 { 123 124 if (in.name == NULL) { 125 in.name = "stdin"; 126 in.fd = STDIN_FILENO; 127 } else { 128 in.fd = open(in.name, O_RDONLY, 0); 129 if (in.fd < 0) 130 err(EXIT_FAILURE, "%s", printescaped(in.name)); 131 /* NOTREACHED */ 132 } 133 134 getfdtype(&in); 135 136 if (files_cnt > 1 && !(in.flags & ISTAPE)) { 137 errx(EXIT_FAILURE, "files is not supported for non-tape devices"); 138 /* NOTREACHED */ 139 } 140 141 if (out.name == NULL) { 142 /* No way to check for read access here. */ 143 out.fd = STDOUT_FILENO; 144 out.name = "stdout"; 145 } else { 146 #define OFLAGS \ 147 (O_CREAT | (ddflags & (C_SEEK | C_NOTRUNC) ? 0 : O_TRUNC)) 148 out.fd = open(out.name, O_RDWR | OFLAGS, DEFFILEMODE); 149 /* 150 * May not have read access, so try again with write only. 151 * Without read we may have a problem if output also does 152 * not support seeks. 153 */ 154 if (out.fd < 0) { 155 out.fd = open(out.name, O_WRONLY | OFLAGS, DEFFILEMODE); 156 out.flags |= NOREAD; 157 } 158 if (out.fd < 0) { 159 err(EXIT_FAILURE, "%s", printescaped(out.name)); 160 /* NOTREACHED */ 161 } 162 } 163 164 getfdtype(&out); 165 166 /* 167 * Allocate space for the input and output buffers. If not doing 168 * record oriented I/O, only need a single buffer. 169 */ 170 if (!(ddflags & (C_BLOCK|C_UNBLOCK))) { 171 if ((in.db = malloc(out.dbsz + in.dbsz - 1)) == NULL) { 172 err(EXIT_FAILURE, NULL); 173 /* NOTREACHED */ 174 } 175 out.db = in.db; 176 } else if ((in.db = 177 malloc((u_int)(MAX(in.dbsz, cbsz) + cbsz))) == NULL || 178 (out.db = malloc((u_int)(out.dbsz + cbsz))) == NULL) { 179 err(EXIT_FAILURE, NULL); 180 /* NOTREACHED */ 181 } 182 in.dbp = in.db; 183 out.dbp = out.db; 184 185 /* Position the input/output streams. */ 186 if (in.offset) 187 pos_in(); 188 if (out.offset) 189 pos_out(); 190 191 /* 192 * Truncate the output file; ignore errors because it fails on some 193 * kinds of output files, tapes, for example. 194 */ 195 if ((ddflags & (C_OF | C_SEEK | C_NOTRUNC)) == (C_OF | C_SEEK)) 196 (void)ftruncate(out.fd, (off_t)out.offset * out.dbsz); 197 198 /* 199 * If converting case at the same time as another conversion, build a 200 * table that does both at once. If just converting case, use the 201 * built-in tables. 202 */ 203 if (ddflags & (C_LCASE|C_UCASE)) { 204 #ifdef NO_CONV 205 /* Should not get here, but just in case... */ 206 errx(EXIT_FAILURE, "case conv and -DNO_CONV"); 207 /* NOTREACHED */ 208 #else /* NO_CONV */ 209 u_int cnt; 210 211 if (ddflags & C_ASCII || ddflags & C_EBCDIC) { 212 if (ddflags & C_LCASE) { 213 for (cnt = 0; cnt < 0377; ++cnt) 214 casetab[cnt] = tolower(ctab[cnt]); 215 } else { 216 for (cnt = 0; cnt < 0377; ++cnt) 217 casetab[cnt] = toupper(ctab[cnt]); 218 } 219 } else { 220 if (ddflags & C_LCASE) { 221 for (cnt = 0; cnt < 0377; ++cnt) 222 casetab[cnt] = tolower(cnt); 223 } else { 224 for (cnt = 0; cnt < 0377; ++cnt) 225 casetab[cnt] = toupper(cnt); 226 } 227 } 228 229 ctab = casetab; 230 #endif /* NO_CONV */ 231 } 232 233 (void)gettimeofday(&st.start, NULL); /* Statistics timestamp. */ 234 } 235 236 static void 237 getfdtype(IO *io) 238 { 239 struct mtget mt; 240 struct stat sb; 241 242 if (fstat(io->fd, &sb)) { 243 err(EXIT_FAILURE, "%s", printescaped(io->name)); 244 /* NOTREACHED */ 245 } 246 if (S_ISCHR(sb.st_mode)) 247 io->flags |= ioctl(io->fd, MTIOCGET, &mt) ? ISCHR : ISTAPE; 248 else if (lseek(io->fd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) 249 io->flags |= ISPIPE; /* XXX fixed in 4.4BSD */ 250 } 251 252 static void 253 dd_in(void) 254 { 255 int flags; 256 int64_t n; 257 258 for (flags = ddflags;;) { 259 if (cpy_cnt && (st.in_full + st.in_part) >= cpy_cnt) 260 return; 261 262 /* 263 * Clear the buffer first if doing "sync" on input. 264 * If doing block operations use spaces. This will 265 * affect not only the C_NOERROR case, but also the 266 * last partial input block which should be padded 267 * with zero and not garbage. 268 */ 269 if (flags & C_SYNC) { 270 if (flags & (C_BLOCK|C_UNBLOCK)) 271 (void)memset(in.dbp, ' ', in.dbsz); 272 else 273 (void)memset(in.dbp, 0, in.dbsz); 274 } 275 276 n = read(in.fd, in.dbp, in.dbsz); 277 if (n == 0) { 278 in.dbrcnt = 0; 279 return; 280 } 281 282 /* Read error. */ 283 if (n < 0) { 284 char *fn; 285 286 fn = printescaped(in.name); 287 /* 288 * If noerror not specified, die. POSIX requires that 289 * the warning message be followed by an I/O display. 290 */ 291 if (!(flags & C_NOERROR)) { 292 err(EXIT_FAILURE, "%s", fn); 293 /* NOTREACHED */ 294 } 295 warn("%s", fn); 296 summary(); 297 298 /* 299 * If it's not a tape drive or a pipe, seek past the 300 * error. If your OS doesn't do the right thing for 301 * raw disks this section should be modified to re-read 302 * in sector size chunks. 303 */ 304 if (!(in.flags & (ISPIPE|ISTAPE)) && 305 lseek(in.fd, (off_t)in.dbsz, SEEK_CUR)) 306 warn("%s", fn); 307 308 /* 309 * Free memory from printescaped() before possible 310 * continue 311 */ 312 free(fn); 313 314 /* If sync not specified, omit block and continue. */ 315 if (!(ddflags & C_SYNC)) 316 continue; 317 318 /* Read errors count as full blocks. */ 319 in.dbcnt += in.dbrcnt = in.dbsz; 320 ++st.in_full; 321 322 /* Handle full input blocks. */ 323 } else if (n == in.dbsz) { 324 in.dbcnt += in.dbrcnt = n; 325 ++st.in_full; 326 327 /* Handle partial input blocks. */ 328 } else { 329 /* If sync, use the entire block. */ 330 if (ddflags & C_SYNC) 331 in.dbcnt += in.dbrcnt = in.dbsz; 332 else 333 in.dbcnt += in.dbrcnt = n; 334 ++st.in_part; 335 } 336 337 /* 338 * POSIX states that if bs is set and no other conversions 339 * than noerror, notrunc or sync are specified, the block 340 * is output without buffering as it is read. 341 */ 342 if (ddflags & C_BS) { 343 out.dbcnt = in.dbcnt; 344 dd_out(1); 345 in.dbcnt = 0; 346 continue; 347 } 348 349 if (ddflags & C_SWAB) { 350 if ((n = in.dbrcnt) & 1) { 351 ++st.swab; 352 --n; 353 } 354 swab(in.dbp, in.dbp, n); 355 } 356 357 in.dbp += in.dbrcnt; 358 (*cfunc)(); 359 } 360 } 361 362 /* 363 * Cleanup any remaining I/O and flush output. If necesssary, output file 364 * is truncated. 365 */ 366 static void 367 dd_close(void) 368 { 369 370 if (cfunc == def) 371 def_close(); 372 else if (cfunc == block) 373 block_close(); 374 else if (cfunc == unblock) 375 unblock_close(); 376 if (ddflags & C_OSYNC && out.dbcnt < out.dbsz) { 377 (void)memset(out.dbp, 0, out.dbsz - out.dbcnt); 378 out.dbcnt = out.dbsz; 379 } 380 if (out.dbcnt) 381 dd_out(1); 382 383 /* 384 * Reporting nfs write error may be defered until next 385 * write(2) or close(2) system call. So, we need to do an 386 * extra check. If an output is stdout, the file structure 387 * may be shared among with other processes and close(2) just 388 * decreases the reference count. 389 */ 390 if (out.fd == STDOUT_FILENO && fsync(out.fd) == -1 && errno != EINVAL) { 391 err(EXIT_FAILURE, "fsync stdout"); 392 /* NOTREACHED */ 393 } 394 if (close(out.fd) == -1) { 395 err(EXIT_FAILURE, "close"); 396 /* NOTREACHED */ 397 } 398 } 399 400 void 401 dd_out(int force) 402 { 403 static int warned; 404 int64_t cnt, n, nw; 405 u_char *outp; 406 407 /* 408 * Write one or more blocks out. The common case is writing a full 409 * output block in a single write; increment the full block stats. 410 * Otherwise, we're into partial block writes. If a partial write, 411 * and it's a character device, just warn. If a tape device, quit. 412 * 413 * The partial writes represent two cases. 1: Where the input block 414 * was less than expected so the output block was less than expected. 415 * 2: Where the input block was the right size but we were forced to 416 * write the block in multiple chunks. The original versions of dd(1) 417 * never wrote a block in more than a single write, so the latter case 418 * never happened. 419 * 420 * One special case is if we're forced to do the write -- in that case 421 * we play games with the buffer size, and it's usually a partial write. 422 */ 423 outp = out.db; 424 for (n = force ? out.dbcnt : out.dbsz;; n = out.dbsz) { 425 for (cnt = n;; cnt -= nw) { 426 char *fn; 427 428 fn = printescaped(out.name); 429 nw = bwrite(out.fd, outp, cnt); 430 if (nw <= 0) { 431 if (nw == 0) 432 errx(EXIT_FAILURE, 433 "%s: end of device", fn); 434 /* NOTREACHED */ 435 if (errno != EINTR) 436 err(EXIT_FAILURE, "%s", fn); 437 /* NOTREACHED */ 438 nw = 0; 439 } 440 outp += nw; 441 st.bytes += nw; 442 if (nw == n) { 443 if (n != out.dbsz) 444 ++st.out_part; 445 else 446 ++st.out_full; 447 free(fn); 448 break; 449 } 450 ++st.out_part; 451 if (nw == cnt) { 452 free(fn); 453 break; 454 } 455 if (out.flags & ISCHR && !warned) { 456 warned = 1; 457 warnx("%s: short write on character device", fn); 458 } 459 if (out.flags & ISTAPE) 460 errx(EXIT_FAILURE, 461 "%s: short write on tape device", fn); 462 /* NOTREACHED */ 463 464 free(fn); 465 } 466 if ((out.dbcnt -= n) < out.dbsz) 467 break; 468 } 469 470 /* Reassemble the output block. */ 471 if (out.dbcnt) 472 (void)memmove(out.db, out.dbp - out.dbcnt, out.dbcnt); 473 out.dbp = out.db + out.dbcnt; 474 475 if (progress) 476 (void)write(STDERR_FILENO, ".", 1); 477 } 478 479 /* 480 * A protected against SIGINFO write 481 */ 482 ssize_t 483 bwrite(int fd, const void *buf, size_t len) 484 { 485 sigset_t oset; 486 ssize_t rv; 487 int oerrno; 488 489 (void)sigprocmask(SIG_BLOCK, &infoset, &oset); 490 rv = write(fd, buf, len); 491 oerrno = errno; 492 (void)sigprocmask(SIG_SETMASK, &oset, NULL); 493 errno = oerrno; 494 return (rv); 495 } 496
Indexes created Sat Sep 27 14:09:57 GMT 2025