dd.c revision 50460
1/*- 2 * Copyright (c) 1991, 1993, 1994 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Keith Muller of the University of California, San Diego and Lance 7 * Visser of Convex Computer Corporation. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by the University of 20 * California, Berkeley and its contributors. 21 * 4. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 */ 37 38#ifndef lint 39static char const copyright[] = 40"@(#) Copyright (c) 1991, 1993, 1994\n\ 41 The Regents of the University of California. All rights reserved.\n"; 42#endif /* not lint */ 43 44#ifndef lint 45#if 0 46static char sccsid[] = "@(#)dd.c 8.5 (Berkeley) 4/2/94"; 47#endif 48static const char rcsid[] = 49 "$Id: dd.c,v 1.19 1999/07/13 18:44:56 green Exp $"; 50#endif /* not lint */ 51 52#include <sys/param.h> 53#include <sys/stat.h> 54#include <sys/conf.h> 55#include <sys/diskslice.h> 56#include <sys/filio.h> 57#include <sys/mtio.h> 58 59#include <ctype.h> 60#include <err.h> 61#include <errno.h> 62#include <fcntl.h> 63#include <locale.h> 64#include <stdio.h> 65#include <stdlib.h> 66#include <string.h> 67#include <unistd.h> 68 69#include "dd.h" 70#include "extern.h" 71 72static void dd_close __P((void)); 73static void dd_in __P((void)); 74static void getfdtype __P((IO *)); 75static void setup __P((void)); 76 77IO in, out; /* input/output state */ 78STAT st; /* statistics */ 79void (*cfunc) __P((void)); /* conversion function */ 80quad_t cpy_cnt; /* # of blocks to copy */ 81off_t pending = 0; /* pending seek if sparse */ 82u_int ddflags; /* conversion options */ 83int cbsz; /* conversion block size */ 84quad_t files_cnt = 1; /* # of files to copy */ 85u_char *ctab; /* conversion table */ 86 87int 88main(argc, argv) 89 int argc; 90 char *argv[]; 91{ 92 (void)setlocale(LC_CTYPE, ""); 93 jcl(argv); 94 setup(); 95 96 (void)signal(SIGINFO, summaryx); 97 (void)signal(SIGINT, terminate); 98 99 atexit(summary); 100 101 while (files_cnt--) 102 dd_in(); 103 104 dd_close(); 105 exit(0); 106} 107 108static void 109setup() 110{ 111 u_int cnt; 112 struct timeval tv; 113 114 if (in.name == NULL) { 115 in.name = "stdin"; 116 in.fd = STDIN_FILENO; 117 } else { 118 in.fd = open(in.name, O_RDONLY, 0); 119 if (in.fd == -1) 120 err(1, "%s", in.name); 121 } 122 123 getfdtype(&in); 124 125 if (files_cnt > 1 && !(in.flags & ISTAPE)) 126 errx(1, "files is not supported for non-tape devices"); 127 128 if (out.name == NULL) { 129 /* No way to check for read access here. */ 130 out.fd = STDOUT_FILENO; 131 out.name = "stdout"; 132 } else { 133#define OFLAGS \ 134 (O_CREAT | (ddflags & (C_SEEK | C_NOTRUNC) ? 0 : O_TRUNC)) 135 out.fd = open(out.name, O_RDWR | OFLAGS, DEFFILEMODE); 136 /* 137 * May not have read access, so try again with write only. 138 * Without read we may have a problem if output also does 139 * not support seeks. 140 */ 141 if (out.fd == -1) { 142 out.fd = open(out.name, O_WRONLY | OFLAGS, DEFFILEMODE); 143 out.flags |= NOREAD; 144 } 145 if (out.fd == -1) 146 err(1, "%s", out.name); 147 } 148 149 getfdtype(&out); 150 151 /* 152 * Allocate space for the input and output buffers. If not doing 153 * record oriented I/O, only need a single buffer. 154 */ 155 if (!(ddflags & (C_BLOCK|C_UNBLOCK))) { 156 if ((in.db = malloc(out.dbsz + in.dbsz - 1)) == NULL) 157 err(1, NULL); 158 out.db = in.db; 159 } else if ((in.db = malloc((u_int)(MAX(in.dbsz, cbsz) + cbsz))) == NULL 160 || (out.db = malloc((u_int)(out.dbsz + cbsz))) == NULL) 161 err(1, NULL); 162 in.dbp = in.db; 163 out.dbp = out.db; 164 165 /* Position the input/output streams. */ 166 if (in.offset) 167 pos_in(); 168 if (out.offset) 169 pos_out(); 170 171 /* 172 * Truncate the output file; ignore errors because it fails on some 173 * kinds of output files, tapes, for example. 174 */ 175 if ((ddflags & (C_OF | C_SEEK | C_NOTRUNC)) == (C_OF | C_SEEK)) 176 (void)ftruncate(out.fd, out.offset * out.dbsz); 177 178 /* 179 * If converting case at the same time as another conversion, build a 180 * table that does both at once. If just converting case, use the 181 * built-in tables. 182 */ 183 if (ddflags & (C_LCASE|C_UCASE)) { 184 if (ddflags & C_ASCII) { 185 if (ddflags & C_LCASE) { 186 for (cnt = 0; cnt <= 0377; ++cnt) 187 if (isupper(ctab[cnt])) 188 ctab[cnt] = tolower(ctab[cnt]); 189 } else { 190 for (cnt = 0; cnt <= 0377; ++cnt) 191 if (islower(ctab[cnt])) 192 ctab[cnt] = toupper(ctab[cnt]); 193 } 194 } else if (ddflags & C_EBCDIC) { 195 if (ddflags & C_LCASE) { 196 for (cnt = 0; cnt <= 0377; ++cnt) 197 if (isupper(cnt)) 198 ctab[cnt] = ctab[tolower(cnt)]; 199 } else { 200 for (cnt = 0; cnt <= 0377; ++cnt) 201 if (islower(cnt)) 202 ctab[cnt] = ctab[toupper(cnt)]; 203 } 204 } else { 205 ctab = ddflags & C_LCASE ? u2l : l2u; 206 if (ddflags & C_LCASE) { 207 for (cnt = 0; cnt <= 0377; ++cnt) 208 if (isupper(cnt)) 209 ctab[cnt] = tolower(cnt); 210 else 211 ctab[cnt] = cnt; 212 } else { 213 for (cnt = 0; cnt <= 0377; ++cnt) 214 if (islower(cnt)) 215 ctab[cnt] = toupper(cnt); 216 else 217 ctab[cnt] = cnt; 218 } 219 } 220 } 221 (void)gettimeofday(&tv, (struct timezone *)NULL); 222 st.start = tv.tv_sec + tv.tv_usec * 1e-6; 223} 224 225static void 226getfdtype(io) 227 IO *io; 228{ 229 struct stat sb; 230 int type; 231 232 if (fstat(io->fd, &sb)) 233 err(1, "%s", io->name); 234 if (S_ISCHR(sb.st_mode) || S_ISBLK(sb.st_mode)) { 235 if (ioctl(io->fd, FIODTYPE, &type) == -1) 236 err(1, "%s", io->name); 237 if (type & D_TAPE) 238 io->flags |= ISTAPE; 239 else if (type & D_DISK) 240 io->flags |= ISDISK; 241 if (S_ISCHR(sb.st_mode) && (type & D_TAPE) == 0) 242 io->flags |= ISCHR; 243 } else if (!S_ISREG(sb.st_mode)) 244 io->flags |= ISPIPE; 245} 246 247static void 248dd_in() 249{ 250 ssize_t n; 251 252 for (;;) { 253 if (cpy_cnt && (st.in_full + st.in_part) >= cpy_cnt) 254 return; 255 256 /* 257 * Zero the buffer first if sync; If doing block operations 258 * use spaces. 259 */ 260 if (ddflags & C_SYNC) { 261 if (ddflags & (C_BLOCK|C_UNBLOCK)) 262 memset(in.dbp, ' ', in.dbsz); 263 else 264 memset(in.dbp, 0, in.dbsz); 265 } 266 267 n = read(in.fd, in.dbp, in.dbsz); 268 if (n == 0) { 269 in.dbrcnt = 0; 270 return; 271 } 272 273 /* Read error. */ 274 if (n == -1) { 275 /* 276 * If noerror not specified, die. POSIX requires that 277 * the warning message be followed by an I/O display. 278 */ 279 if (!(ddflags & C_NOERROR)) 280 err(1, "%s", in.name); 281 warn("%s", in.name); 282 summary(); 283 284 /* 285 * If it's not a tape drive or a pipe, seek past the 286 * error. If your OS doesn't do the right thing for 287 * raw disks this section should be modified to re-read 288 * in sector size chunks. 289 */ 290 if (!(in.flags & (ISPIPE|ISTAPE)) && 291 lseek(in.fd, (off_t)in.dbsz, SEEK_CUR)) 292 warn("%s", in.name); 293 294 /* If sync not specified, omit block and continue. */ 295 if (!(ddflags & C_SYNC)) 296 continue; 297 298 /* Read errors count as full blocks. */ 299 in.dbcnt += in.dbrcnt = in.dbsz; 300 ++st.in_full; 301 302 /* Handle full input blocks. */ 303 } else if (n == in.dbsz) { 304 in.dbcnt += in.dbrcnt = n; 305 ++st.in_full; 306 307 /* Handle partial input blocks. */ 308 } else { 309 /* If sync, use the entire block. */ 310 if (ddflags & C_SYNC) 311 in.dbcnt += in.dbrcnt = in.dbsz; 312 else 313 in.dbcnt += in.dbrcnt = n; 314 ++st.in_part; 315 } 316 317 /* 318 * POSIX states that if bs is set and no other conversions 319 * than noerror, notrunc or sync are specified, the block 320 * is output without buffering as it is read. 321 */ 322 if (ddflags & C_BS) { 323 out.dbcnt = in.dbcnt; 324 dd_out(1); 325 in.dbcnt = 0; 326 continue; 327 } 328 329 if (ddflags & C_SWAB) { 330 if ((n = in.dbrcnt) & 1) { 331 ++st.swab; 332 --n; 333 } 334 swab(in.dbp, in.dbp, n); 335 } 336 337 in.dbp += in.dbrcnt; 338 (*cfunc)(); 339 } 340} 341 342/* 343 * Cleanup any remaining I/O and flush output. If necesssary, output file 344 * is truncated. 345 */ 346static void 347dd_close() 348{ 349 if (cfunc == def) 350 def_close(); 351 else if (cfunc == block) 352 block_close(); 353 else if (cfunc == unblock) 354 unblock_close(); 355 if (ddflags & C_OSYNC && out.dbcnt && out.dbcnt < out.dbsz) { 356 if (ddflags & (C_BLOCK|C_UNBLOCK)) 357 memset(out.dbp, ' ', out.dbsz - out.dbcnt); 358 else 359 memset(out.dbp, 0, out.dbsz - out.dbcnt); 360 out.dbcnt = out.dbsz; 361 } 362 if (out.dbcnt || pending) 363 dd_out(1); 364} 365 366void 367dd_out(force) 368 int force; 369{ 370 static int warned; 371 int cnt, n, i, sparse; 372 ssize_t nw; 373 u_char *outp; 374 375 /* 376 * Write one or more blocks out. The common case is writing a full 377 * output block in a single write; increment the full block stats. 378 * Otherwise, we're into partial block writes. If a partial write, 379 * and it's a character device, just warn. If a tape device, quit. 380 * 381 * The partial writes represent two cases. 1: Where the input block 382 * was less than expected so the output block was less than expected. 383 * 2: Where the input block was the right size but we were forced to 384 * write the block in multiple chunks. The original versions of dd(1) 385 * never wrote a block in more than a single write, so the latter case 386 * never happened. 387 * 388 * One special case is if we're forced to do the write -- in that case 389 * we play games with the buffer size, and it's usually a partial write. 390 */ 391 outp = out.db; 392 for (n = force ? out.dbcnt : out.dbsz;; n = out.dbsz) { 393 for (cnt = n;; cnt -= nw) { 394 sparse = 0; 395 if (ddflags & C_SPARSE) { 396 sparse = 1; /* Is buffer sparse? */ 397 for (i = 0; i < cnt; i++) 398 if (outp[i] != 0) { 399 sparse = 0; 400 break; 401 } 402 } 403 if (sparse && !force) { 404 pending += cnt; 405 nw = cnt; 406 } else { 407 if (pending != 0) { 408 if (force) 409 pending--; 410 if (lseek(out.fd, pending, SEEK_CUR) == 411 -1) 412 err(2, "%s: seek error creating sparse file", 413 out.name); 414 if (force) 415 write(out.fd, outp, 1); 416 pending = 0; 417 } 418 if (cnt) 419 nw = write(out.fd, outp, cnt); 420 else 421 return; 422 } 423 424 if (nw <= 0) { 425 if (nw == 0) 426 errx(1, "%s: end of device", out.name); 427 if (errno != EINTR) 428 err(1, "%s", out.name); 429 nw = 0; 430 } 431 outp += nw; 432 st.bytes += nw; 433 if (nw == n) { 434 if (n != out.dbsz) 435 ++st.out_part; 436 else 437 ++st.out_full; 438 break; 439 } 440 ++st.out_part; 441 if (nw == cnt) 442 break; 443 if (out.flags & ISCHR && !warned) { 444 warned = 1; 445 warnx("%s: short write on character device", 446 out.name); 447 } 448 if (out.flags & ISTAPE) 449 errx(1, "%s: short write on tape device", out.name); 450 } 451 if ((out.dbcnt -= n) < out.dbsz) 452 break; 453 } 454 455 /* Reassemble the output block. */ 456 if (out.dbcnt) 457 memmove(out.db, out.dbp - out.dbcnt, out.dbcnt); 458 out.dbp = out.db + out.dbcnt; 459} 460