dd.c revision 1.30
1 /* $NetBSD: dd.c,v 1.30 2003/08/04 22:31:23 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. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 */ 39 40 #include <sys/cdefs.h> 41 #ifndef lint 42 __COPYRIGHT("@(#) Copyright (c) 1991, 1993, 1994\n\ 43 The Regents of the University of California. All rights reserved.\n"); 44 #endif /* not lint */ 45 46 #ifndef lint 47 #if 0 48 static char sccsid[] = "@(#)dd.c 8.5 (Berkeley) 4/2/94"; 49 #else 50 __RCSID("$NetBSD: dd.c,v 1.30 2003/08/04 22:31:23 jschauma Exp $"); 51 #endif 52 #endif /* not lint */ 53 54 #include <sys/param.h> 55 #include <sys/stat.h> 56 #include <sys/ioctl.h> 57 #include <sys/mtio.h> 58 #include <sys/time.h> 59 60 #include <ctype.h> 61 #include <err.h> 62 #include <errno.h> 63 #include <fcntl.h> 64 #include <signal.h> 65 #include <stdio.h> 66 #include <stdlib.h> 67 #include <string.h> 68 #include <unistd.h> 69 70 #include "dd.h" 71 #include "extern.h" 72 73 static void dd_close(void); 74 static void dd_in(void); 75 static void getfdtype(IO *); 76 static void setup(void); 77 78 int main(int, char *[]); 79 80 IO in, out; /* input/output state */ 81 STAT st; /* statistics */ 82 void (*cfunc)(void); /* conversion function */ 83 uint64_t cpy_cnt; /* # of blocks to copy */ 84 u_int ddflags; /* conversion options */ 85 uint64_t cbsz; /* conversion block size */ 86 u_int files_cnt = 1; /* # of files to copy */ 87 int progress = 0; /* display sign of life */ 88 const u_char *ctab; /* conversion table */ 89 sigset_t infoset; /* a set blocking SIGINFO */ 90 91 int 92 main(int argc, char *argv[]) 93 { 94 int ch; 95 96 while ((ch = getopt(argc, argv, "")) != -1) { 97 switch (ch) { 98 default: 99 errx(EXIT_FAILURE, "usage: dd [operand ...]"); 100 /* NOTREACHED */ 101 } 102 } 103 argc -= (optind - 1); 104 argv += (optind - 1); 105 106 jcl(argv); 107 setup(); 108 109 (void)signal(SIGINFO, summaryx); 110 (void)signal(SIGINT, terminate); 111 (void)sigemptyset(&infoset); 112 (void)sigaddset(&infoset, SIGINFO); 113 114 (void)atexit(summary); 115 116 while (files_cnt--) 117 dd_in(); 118 119 dd_close(); 120 exit(0); 121 /* NOTREACHED */ 122 } 123 124 static void 125 setup(void) 126 { 127 128 if (in.name == NULL) { 129 in.name = "stdin"; 130 in.fd = STDIN_FILENO; 131 } else { 132 in.fd = open(in.name, O_RDONLY, 0); 133 if (in.fd < 0) 134 err(EXIT_FAILURE, "%s", printescaped(in.name)); 135 /* NOTREACHED */ 136 } 137 138 getfdtype(&in); 139 140 if (files_cnt > 1 && !(in.flags & ISTAPE)) { 141 errx(EXIT_FAILURE, "files is not supported for non-tape devices"); 142 /* NOTREACHED */ 143 } 144 145 if (out.name == NULL) { 146 /* No way to check for read access here. */ 147 out.fd = STDOUT_FILENO; 148 out.name = "stdout"; 149 } else { 150 #define OFLAGS \ 151 (O_CREAT | (ddflags & (C_SEEK | C_NOTRUNC) ? 0 : O_TRUNC)) 152 out.fd = open(out.name, O_RDWR | OFLAGS, DEFFILEMODE); 153 /* 154 * May not have read access, so try again with write only. 155 * Without read we may have a problem if output also does 156 * not support seeks. 157 */ 158 if (out.fd < 0) { 159 out.fd = open(out.name, O_WRONLY | OFLAGS, DEFFILEMODE); 160 out.flags |= NOREAD; 161 } 162 if (out.fd < 0) { 163 err(EXIT_FAILURE, "%s", printescaped(out.name)); 164 /* NOTREACHED */ 165 } 166 } 167 168 getfdtype(&out); 169 170 /* 171 * Allocate space for the input and output buffers. If not doing 172 * record oriented I/O, only need a single buffer. 173 */ 174 if (!(ddflags & (C_BLOCK|C_UNBLOCK))) { 175 if ((in.db = malloc(out.dbsz + in.dbsz - 1)) == NULL) { 176 err(EXIT_FAILURE, NULL); 177 /* NOTREACHED */ 178 } 179 out.db = in.db; 180 } else if ((in.db = 181 malloc((u_int)(MAX(in.dbsz, cbsz) + cbsz))) == NULL || 182 (out.db = malloc((u_int)(out.dbsz + cbsz))) == NULL) { 183 err(EXIT_FAILURE, NULL); 184 /* NOTREACHED */ 185 } 186 in.dbp = in.db; 187 out.dbp = out.db; 188 189 /* Position the input/output streams. */ 190 if (in.offset) 191 pos_in(); 192 if (out.offset) 193 pos_out(); 194 195 /* 196 * Truncate the output file; ignore errors because it fails on some 197 * kinds of output files, tapes, for example. 198 */ 199 if ((ddflags & (C_OF | C_SEEK | C_NOTRUNC)) == (C_OF | C_SEEK)) 200 (void)ftruncate(out.fd, (off_t)out.offset * out.dbsz); 201 202 /* 203 * If converting case at the same time as another conversion, build a 204 * table that does both at once. If just converting case, use the 205 * built-in tables. 206 */ 207 if (ddflags & (C_LCASE|C_UCASE)) { 208 #ifdef NO_CONV 209 /* Should not get here, but just in case... */ 210 errx(EXIT_FAILURE, "case conv and -DNO_CONV"); 211 /* NOTREACHED */ 212 #else /* NO_CONV */ 213 u_int cnt; 214 215 if (ddflags & C_ASCII || ddflags & C_EBCDIC) { 216 if (ddflags & C_LCASE) { 217 for (cnt = 0; cnt < 0377; ++cnt) 218 casetab[cnt] = tolower(ctab[cnt]); 219 } else { 220 for (cnt = 0; cnt < 0377; ++cnt) 221 casetab[cnt] = toupper(ctab[cnt]); 222 } 223 } else { 224 if (ddflags & C_LCASE) { 225 for (cnt = 0; cnt < 0377; ++cnt) 226 casetab[cnt] = tolower(cnt); 227 } else { 228 for (cnt = 0; cnt < 0377; ++cnt) 229 casetab[cnt] = toupper(cnt); 230 } 231 } 232 233 ctab = casetab; 234 #endif /* NO_CONV */ 235 } 236 237 (void)gettimeofday(&st.start, NULL); /* Statistics timestamp. */ 238 } 239 240 static void 241 getfdtype(IO *io) 242 { 243 struct mtget mt; 244 struct stat sb; 245 246 if (fstat(io->fd, &sb)) { 247 err(EXIT_FAILURE, "%s", printescaped(io->name)); 248 /* NOTREACHED */ 249 } 250 if (S_ISCHR(sb.st_mode)) 251 io->flags |= ioctl(io->fd, MTIOCGET, &mt) ? ISCHR : ISTAPE; 252 else if (lseek(io->fd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) 253 io->flags |= ISPIPE; /* XXX fixed in 4.4BSD */ 254 } 255 256 static void 257 dd_in(void) 258 { 259 int flags; 260 int64_t n; 261 262 for (flags = ddflags;;) { 263 if (cpy_cnt && (st.in_full + st.in_part) >= cpy_cnt) 264 return; 265 266 /* 267 * Clear the buffer first if doing "sync" on input. 268 * If doing block operations use spaces. This will 269 * affect not only the C_NOERROR case, but also the 270 * last partial input block which should be padded 271 * with zero and not garbage. 272 */ 273 if (flags & C_SYNC) { 274 if (flags & (C_BLOCK|C_UNBLOCK)) 275 (void)memset(in.dbp, ' ', in.dbsz); 276 else 277 (void)memset(in.dbp, 0, in.dbsz); 278 } 279 280 n = read(in.fd, in.dbp, in.dbsz); 281 if (n == 0) { 282 in.dbrcnt = 0; 283 return; 284 } 285 286 /* Read error. */ 287 if (n < 0) { 288 char *fn; 289 290 fn = printescaped(in.name); 291 /* 292 * If noerror not specified, die. POSIX requires that 293 * the warning message be followed by an I/O display. 294 */ 295 if (!(flags & C_NOERROR)) { 296 err(EXIT_FAILURE, "%s", fn); 297 /* NOTREACHED */ 298 } 299 warn("%s", fn); 300 summary(); 301 302 /* 303 * If it's not a tape drive or a pipe, seek past the 304 * error. If your OS doesn't do the right thing for 305 * raw disks this section should be modified to re-read 306 * in sector size chunks. 307 */ 308 if (!(in.flags & (ISPIPE|ISTAPE)) && 309 lseek(in.fd, (off_t)in.dbsz, SEEK_CUR)) 310 warn("%s", fn); 311 312 /* If sync not specified, omit block and continue. */ 313 if (!(ddflags & C_SYNC)) 314 continue; 315 316 /* Read errors count as full blocks. */ 317 in.dbcnt += in.dbrcnt = in.dbsz; 318 ++st.in_full; 319 320 free(fn); 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 break; 448 } 449 ++st.out_part; 450 if (nw == cnt) 451 break; 452 if (out.flags & ISCHR && !warned) { 453 warned = 1; 454 warnx("%s: short write on character device", fn); 455 } 456 if (out.flags & ISTAPE) 457 errx(EXIT_FAILURE, 458 "%s: short write on tape device", fn); 459 /* NOTREACHED */ 460 461 free(fn); 462 } 463 if ((out.dbcnt -= n) < out.dbsz) 464 break; 465 } 466 467 /* Reassemble the output block. */ 468 if (out.dbcnt) 469 (void)memmove(out.db, out.dbp - out.dbcnt, out.dbcnt); 470 out.dbp = out.db + out.dbcnt; 471 472 if (progress) 473 (void)write(STDERR_FILENO, ".", 1); 474 } 475 476 /* 477 * A protected against SIGINFO write 478 */ 479 ssize_t 480 bwrite(int fd, const void *buf, size_t len) 481 { 482 sigset_t oset; 483 ssize_t rv; 484 int oerrno; 485 486 (void)sigprocmask(SIG_BLOCK, &infoset, &oset); 487 rv = write(fd, buf, len); 488 oerrno = errno; 489 (void)sigprocmask(SIG_SETMASK, &oset, NULL); 490 errno = oerrno; 491 return (rv); 492 } 493
Indexes created Sat Sep 27 14:09:57 GMT 2025