1 /* $NetBSD: dd.c,v 1.43 2009/02/14 07:13:40 lukem 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\ 39 The Regents of the University of California. All rights reserved."); 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 1.43 2009/02/14 07:13:40 lukem 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 <locale.h> 61 #include <signal.h> 62 #include <stdio.h> 63 #include <stdlib.h> 64 #include <string.h> 65 #include <unistd.h> 66 67 #include "dd.h" 68 #include "extern.h" 69 70 static void dd_close(void); 71 static void dd_in(void); 72 static void getfdtype(IO *); 73 static int redup_clean_fd(int); 74 static void setup(void); 75 76 int main(int, char *[]); 77 78 IO in, out; /* input/output state */ 79 STAT st; /* statistics */ 80 void (*cfunc)(void); /* conversion function */ 81 uint64_t cpy_cnt; /* # of blocks to copy */ 82 static off_t pending = 0; /* pending seek if sparse */ 83 u_int ddflags; /* conversion options */ 84 uint64_t cbsz; /* conversion block size */ 85 u_int files_cnt = 1; /* # of files to copy */ 86 uint64_t progress = 0; /* display sign of life */ 87 const u_char *ctab; /* conversion table */ 88 sigset_t infoset; /* a set blocking SIGINFO */ 89 90 int 91 main(int argc, char *argv[]) 92 { 93 int ch; 94 95 setprogname(argv[0]); 96 (void)setlocale(LC_ALL, ""); 97 98 while ((ch = getopt(argc, argv, "")) != -1) { 99 switch (ch) { 100 default: 101 errx(EXIT_FAILURE, "usage: dd [operand ...]"); 102 /* NOTREACHED */ 103 } 104 } 105 argc -= (optind - 1); 106 argv += (optind - 1); 107 108 jcl(argv); 109 setup(); 110 111 (void)signal(SIGINFO, summaryx); 112 (void)signal(SIGINT, terminate); 113 (void)sigemptyset(&infoset); 114 (void)sigaddset(&infoset, SIGINFO); 115 116 (void)atexit(summary); 117 118 while (files_cnt--) 119 dd_in(); 120 121 dd_close(); 122 exit(0); 123 /* NOTREACHED */ 124 } 125 126 static void 127 setup(void) 128 { 129 130 if (in.name == NULL) { 131 in.name = "stdin"; 132 in.fd = STDIN_FILENO; 133 } else { 134 in.fd = open(in.name, O_RDONLY, 0); 135 if (in.fd < 0) 136 err(EXIT_FAILURE, "%s", in.name); 137 /* NOTREACHED */ 138 139 /* Ensure in.fd is outside the stdio descriptor range */ 140 in.fd = redup_clean_fd(in.fd); 141 } 142 143 getfdtype(&in); 144 145 if (files_cnt > 1 && !(in.flags & ISTAPE)) { 146 errx(EXIT_FAILURE, "files is not supported for non-tape devices"); 147 /* NOTREACHED */ 148 } 149 150 if (out.name == NULL) { 151 /* No way to check for read access here. */ 152 out.fd = STDOUT_FILENO; 153 out.name = "stdout"; 154 } else { 155 #define OFLAGS \ 156 (O_CREAT | (ddflags & (C_SEEK | C_NOTRUNC) ? 0 : O_TRUNC)) 157 out.fd = open(out.name, O_RDWR | OFLAGS, DEFFILEMODE); 158 /* 159 * May not have read access, so try again with write only. 160 * Without read we may have a problem if output also does 161 * not support seeks. 162 */ 163 if (out.fd < 0) { 164 out.fd = open(out.name, O_WRONLY | OFLAGS, DEFFILEMODE); 165 out.flags |= NOREAD; 166 } 167 if (out.fd < 0) { 168 err(EXIT_FAILURE, "%s", out.name); 169 /* NOTREACHED */ 170 } 171 172 /* Ensure out.fd is outside the stdio descriptor range */ 173 out.fd = redup_clean_fd(out.fd); 174 } 175 176 getfdtype(&out); 177 178 /* 179 * Allocate space for the input and output buffers. If not doing 180 * record oriented I/O, only need a single buffer. 181 */ 182 if (!(ddflags & (C_BLOCK|C_UNBLOCK))) { 183 if ((in.db = malloc(out.dbsz + in.dbsz - 1)) == NULL) { 184 err(EXIT_FAILURE, NULL); 185 /* NOTREACHED */ 186 } 187 out.db = in.db; 188 } else if ((in.db = 189 malloc((u_int)(MAX(in.dbsz, cbsz) + cbsz))) == NULL || 190 (out.db = malloc((u_int)(out.dbsz + cbsz))) == NULL) { 191 err(EXIT_FAILURE, NULL); 192 /* NOTREACHED */ 193 } 194 in.dbp = in.db; 195 out.dbp = out.db; 196 197 /* Position the input/output streams. */ 198 if (in.offset) 199 pos_in(); 200 if (out.offset) 201 pos_out(); 202 203 /* 204 * Truncate the output file; ignore errors because it fails on some 205 * kinds of output files, tapes, for example. 206 */ 207 if ((ddflags & (C_OF | C_SEEK | C_NOTRUNC)) == (C_OF | C_SEEK)) 208 (void)ftruncate(out.fd, (off_t)out.offset * out.dbsz); 209 210 /* 211 * If converting case at the same time as another conversion, build a 212 * table that does both at once. If just converting case, use the 213 * built-in tables. 214 */ 215 if (ddflags & (C_LCASE|C_UCASE)) { 216 #ifdef NO_CONV 217 /* Should not get here, but just in case... */ 218 errx(EXIT_FAILURE, "case conv and -DNO_CONV"); 219 /* NOTREACHED */ 220 #else /* NO_CONV */ 221 u_int cnt; 222 223 if (ddflags & C_ASCII || ddflags & C_EBCDIC) { 224 if (ddflags & C_LCASE) { 225 for (cnt = 0; cnt < 256; ++cnt) 226 casetab[cnt] = tolower(ctab[cnt]); 227 } else { 228 for (cnt = 0; cnt < 256; ++cnt) 229 casetab[cnt] = toupper(ctab[cnt]); 230 } 231 } else { 232 if (ddflags & C_LCASE) { 233 for (cnt = 0; cnt < 256; ++cnt) 234 casetab[cnt] = tolower(cnt); 235 } else { 236 for (cnt = 0; cnt < 256; ++cnt) 237 casetab[cnt] = toupper(cnt); 238 } 239 } 240 241 ctab = casetab; 242 #endif /* NO_CONV */ 243 } 244 245 (void)gettimeofday(&st.start, NULL); /* Statistics timestamp. */ 246 } 247 248 static void 249 getfdtype(IO *io) 250 { 251 struct mtget mt; 252 struct stat sb; 253 254 if (fstat(io->fd, &sb)) { 255 err(EXIT_FAILURE, "%s", io->name); 256 /* NOTREACHED */ 257 } 258 if (S_ISCHR(sb.st_mode)) 259 io->flags |= ioctl(io->fd, MTIOCGET, &mt) ? ISCHR : ISTAPE; 260 else if (lseek(io->fd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) 261 io->flags |= ISPIPE; /* XXX fixed in 4.4BSD */ 262 } 263 264 /* 265 * Move the parameter file descriptor to a descriptor that is outside the 266 * stdio descriptor range, if necessary. This is required to avoid 267 * accidentally outputting completion or error messages into the 268 * output file that were intended for the tty. 269 */ 270 static int 271 redup_clean_fd(int fd) 272 { 273 int newfd; 274 275 if (fd != STDIN_FILENO && fd != STDOUT_FILENO && 276 fd != STDERR_FILENO) 277 /* File descriptor is ok, return immediately. */ 278 return fd; 279 280 /* 281 * 3 is the first descriptor greater than STD*_FILENO. Any 282 * free descriptor valued 3 or above is acceptable... 283 */ 284 newfd = fcntl(fd, F_DUPFD, 3); 285 if (newfd < 0) { 286 err(EXIT_FAILURE, "dupfd IO"); 287 /* NOTREACHED */ 288 } 289 290 close(fd); 291 292 return newfd; 293 } 294 295 static void 296 dd_in(void) 297 { 298 int flags; 299 int64_t n; 300 301 for (flags = ddflags;;) { 302 if (cpy_cnt && (st.in_full + st.in_part) >= cpy_cnt) 303 return; 304 305 /* 306 * Clear the buffer first if doing "sync" on input. 307 * If doing block operations use spaces. This will 308 * affect not only the C_NOERROR case, but also the 309 * last partial input block which should be padded 310 * with zero and not garbage. 311 */ 312 if (flags & C_SYNC) { 313 if (flags & (C_BLOCK|C_UNBLOCK)) 314 (void)memset(in.dbp, ' ', in.dbsz); 315 else 316 (void)memset(in.dbp, 0, in.dbsz); 317 } 318 319 n = read(in.fd, in.dbp, in.dbsz); 320 if (n == 0) { 321 in.dbrcnt = 0; 322 return; 323 } 324 325 /* Read error. */ 326 if (n < 0) { 327 328 /* 329 * If noerror not specified, die. POSIX requires that 330 * the warning message be followed by an I/O display. 331 */ 332 if (!(flags & C_NOERROR)) { 333 err(EXIT_FAILURE, "%s", in.name); 334 /* NOTREACHED */ 335 } 336 warn("%s", in.name); 337 summary(); 338 339 /* 340 * If it's not a tape drive or a pipe, seek past the 341 * error. If your OS doesn't do the right thing for 342 * raw disks this section should be modified to re-read 343 * in sector size chunks. 344 */ 345 if (!(in.flags & (ISPIPE|ISTAPE)) && 346 lseek(in.fd, (off_t)in.dbsz, SEEK_CUR)) 347 warn("%s", in.name); 348 349 /* If sync not specified, omit block and continue. */ 350 if (!(ddflags & C_SYNC)) 351 continue; 352 353 /* Read errors count as full blocks. */ 354 in.dbcnt += in.dbrcnt = in.dbsz; 355 ++st.in_full; 356 357 /* Handle full input blocks. */ 358 } else if ((uint64_t)n == in.dbsz) { 359 in.dbcnt += in.dbrcnt = n; 360 ++st.in_full; 361 362 /* Handle partial input blocks. */ 363 } else { 364 /* If sync, use the entire block. */ 365 if (ddflags & C_SYNC) 366 in.dbcnt += in.dbrcnt = in.dbsz; 367 else 368 in.dbcnt += in.dbrcnt = n; 369 ++st.in_part; 370 } 371 372 /* 373 * POSIX states that if bs is set and no other conversions 374 * than noerror, notrunc or sync are specified, the block 375 * is output without buffering as it is read. 376 */ 377 if (ddflags & C_BS) { 378 out.dbcnt = in.dbcnt; 379 dd_out(1); 380 in.dbcnt = 0; 381 continue; 382 } 383 384 if (ddflags & C_SWAB) { 385 if ((n = in.dbrcnt) & 1) { 386 ++st.swab; 387 --n; 388 } 389 swab(in.dbp, in.dbp, n); 390 } 391 392 in.dbp += in.dbrcnt; 393 (*cfunc)(); 394 } 395 } 396 397 /* 398 * Cleanup any remaining I/O and flush output. If necessary, output file 399 * is truncated. 400 */ 401 static void 402 dd_close(void) 403 { 404 405 if (cfunc == def) 406 def_close(); 407 else if (cfunc == block) 408 block_close(); 409 else if (cfunc == unblock) 410 unblock_close(); 411 if (ddflags & C_OSYNC && out.dbcnt < out.dbsz) { 412 (void)memset(out.dbp, 0, out.dbsz - out.dbcnt); 413 out.dbcnt = out.dbsz; 414 } 415 /* If there are pending sparse blocks, make sure 416 * to write out the final block un-sparse 417 */ 418 if ((out.dbcnt == 0) && pending) { 419 memset(out.db, 0, out.dbsz); 420 out.dbcnt = out.dbsz; 421 out.dbp = out.db + out.dbcnt; 422 pending -= out.dbsz; 423 } 424 if (out.dbcnt) 425 dd_out(1); 426 427 /* 428 * Reporting nfs write error may be defered until next 429 * write(2) or close(2) system call. So, we need to do an 430 * extra check. If an output is stdout, the file structure 431 * may be shared among with other processes and close(2) just 432 * decreases the reference count. 433 */ 434 if (out.fd == STDOUT_FILENO && fsync(out.fd) == -1 && errno != EINVAL) { 435 err(EXIT_FAILURE, "fsync stdout"); 436 /* NOTREACHED */ 437 } 438 if (close(out.fd) == -1) { 439 err(EXIT_FAILURE, "close"); 440 /* NOTREACHED */ 441 } 442 } 443 444 void 445 dd_out(int force) 446 { 447 static int warned; 448 int64_t cnt, n, nw; 449 u_char *outp; 450 451 /* 452 * Write one or more blocks out. The common case is writing a full 453 * output block in a single write; increment the full block stats. 454 * Otherwise, we're into partial block writes. If a partial write, 455 * and it's a character device, just warn. If a tape device, quit. 456 * 457 * The partial writes represent two cases. 1: Where the input block 458 * was less than expected so the output block was less than expected. 459 * 2: Where the input block was the right size but we were forced to 460 * write the block in multiple chunks. The original versions of dd(1) 461 * never wrote a block in more than a single write, so the latter case 462 * never happened. 463 * 464 * One special case is if we're forced to do the write -- in that case 465 * we play games with the buffer size, and it's usually a partial write. 466 */ 467 outp = out.db; 468 for (n = force ? out.dbcnt : out.dbsz;; n = out.dbsz) { 469 for (cnt = n;; cnt -= nw) { 470 471 if (!force && ddflags & C_SPARSE) { 472 int sparse, i; 473 sparse = 1; /* Is buffer sparse? */ 474 for (i = 0; i < cnt; i++) 475 if (outp[i] != 0) { 476 sparse = 0; 477 break; 478 } 479 if (sparse) { 480 pending += cnt; 481 outp += cnt; 482 nw = 0; 483 break; 484 } 485 } 486 if (pending != 0) { 487 if (lseek(out.fd, pending, SEEK_CUR) == 488 -1) 489 err(EXIT_FAILURE, "%s: seek error creating sparse file", 490 out.name); 491 } 492 nw = bwrite(out.fd, outp, cnt); 493 if (nw <= 0) { 494 if (nw == 0) 495 errx(EXIT_FAILURE, 496 "%s: end of device", out.name); 497 /* NOTREACHED */ 498 if (errno != EINTR) 499 err(EXIT_FAILURE, "%s", out.name); 500 /* NOTREACHED */ 501 nw = 0; 502 } 503 if (pending) { 504 st.bytes += pending; 505 st.sparse += pending/out.dbsz; 506 st.out_full += pending/out.dbsz; 507 pending = 0; 508 } 509 outp += nw; 510 st.bytes += nw; 511 if (nw == n) { 512 if ((uint64_t)n != out.dbsz) 513 ++st.out_part; 514 else 515 ++st.out_full; 516 break; 517 } 518 ++st.out_part; 519 if (nw == cnt) 520 break; 521 if (out.flags & ISCHR && !warned) { 522 warned = 1; 523 warnx("%s: short write on character device", out.name); 524 } 525 if (out.flags & ISTAPE) 526 errx(EXIT_FAILURE, 527 "%s: short write on tape device", out.name); 528 /* NOTREACHED */ 529 530 } 531 if ((out.dbcnt -= n) < out.dbsz) 532 break; 533 } 534 535 /* Reassemble the output block. */ 536 if (out.dbcnt) 537 (void)memmove(out.db, out.dbp - out.dbcnt, out.dbcnt); 538 out.dbp = out.db + out.dbcnt; 539 540 if (progress && (st.out_full + st.out_part) % progress == 0) 541 (void)write(STDERR_FILENO, ".", 1); 542 } 543 544 /* 545 * A protected against SIGINFO write 546 */ 547 ssize_t 548 bwrite(int fd, const void *buf, size_t len) 549 { 550 sigset_t oset; 551 ssize_t rv; 552 int oerrno; 553 554 (void)sigprocmask(SIG_BLOCK, &infoset, &oset); 555 rv = write(fd, buf, len); 556 oerrno = errno; 557 (void)sigprocmask(SIG_SETMASK, &oset, NULL); 558 errno = oerrno; 559 return (rv); 560 } 561