dd.c revision 32324
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 * $Id: dd.c,v 1.12 1997/10/11 20:09:05 joerg Exp $ 38 */ 39 40#ifndef lint 41static char const copyright[] = 42"@(#) 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 47static char const sccsid[] = "@(#)dd.c 8.5 (Berkeley) 4/2/94"; 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 55#include <ctype.h> 56#include <err.h> 57#include <errno.h> 58#include <fcntl.h> 59#include <locale.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 69static void dd_close __P((void)); 70static void dd_in __P((void)); 71static void getfdtype __P((IO *)); 72static void setup __P((void)); 73 74IO in, out; /* input/output state */ 75STAT st; /* statistics */ 76void (*cfunc) __P((void)); /* conversion function */ 77u_long cpy_cnt; /* # of blocks to copy */ 78u_long pending = 0; /* pending seek if sparse */ 79u_int ddflags; /* conversion options */ 80u_int cbsz; /* conversion block size */ 81u_int files_cnt = 1; /* # of files to copy */ 82u_char *ctab; /* conversion table */ 83 84int 85main(argc, argv) 86 int argc; 87 char *argv[]; 88{ 89 (void)setlocale(LC_CTYPE, ""); 90 jcl(argv); 91 setup(); 92 93 (void)signal(SIGINFO, summaryx); 94 (void)signal(SIGINT, terminate); 95 96 atexit(summary); 97 98 while (files_cnt--) 99 dd_in(); 100 101 dd_close(); 102 exit(0); 103} 104 105static void 106setup() 107{ 108 u_int cnt; 109 struct timeval tv; 110 111 if (in.name == NULL) { 112 in.name = "stdin"; 113 in.fd = STDIN_FILENO; 114 } else { 115 in.fd = open(in.name, O_RDONLY, 0); 116 if (in.fd < 0) 117 err(1, "%s", in.name); 118 } 119 120 getfdtype(&in); 121 122 if (files_cnt > 1 && !(in.flags & ISTAPE)) 123 errx(1, "files is not supported for non-tape devices"); 124 125 if (out.name == NULL) { 126 /* No way to check for read access here. */ 127 out.fd = STDOUT_FILENO; 128 out.name = "stdout"; 129 } else { 130#define OFLAGS \ 131 (O_CREAT | (ddflags & (C_SEEK | C_NOTRUNC) ? 0 : O_TRUNC)) 132 out.fd = open(out.name, O_RDWR | OFLAGS, DEFFILEMODE); 133 /* 134 * May not have read access, so try again with write only. 135 * Without read we may have a problem if output also does 136 * not support seeks. 137 */ 138 if (out.fd < 0) { 139 out.fd = open(out.name, O_WRONLY | OFLAGS, DEFFILEMODE); 140 out.flags |= NOREAD; 141 } 142 if (out.fd < 0) 143 err(1, "%s", out.name); 144 } 145 146 getfdtype(&out); 147 148 /* 149 * Allocate space for the input and output buffers. If not doing 150 * record oriented I/O, only need a single buffer. 151 */ 152 if (!(ddflags & (C_BLOCK|C_UNBLOCK))) { 153 if ((in.db = malloc(out.dbsz + in.dbsz - 1)) == NULL) 154 err(1, NULL); 155 out.db = in.db; 156 } else if ((in.db = 157 malloc((u_int)(MAX(in.dbsz, cbsz) + cbsz))) == NULL || 158 (out.db = malloc((u_int)(out.dbsz + cbsz))) == NULL) 159 err(1, NULL); 160 in.dbp = in.db; 161 out.dbp = out.db; 162 163 /* Position the input/output streams. */ 164 if (in.offset) 165 pos_in(); 166 if (out.offset) 167 pos_out(); 168 169 /* 170 * Truncate the output file; ignore errors because it fails on some 171 * kinds of output files, tapes, for example. 172 */ 173 if ((ddflags & (C_OF | C_SEEK | C_NOTRUNC)) == (C_OF | C_SEEK)) 174 (void)ftruncate(out.fd, (off_t)out.offset * out.dbsz); 175 176 /* 177 * If converting case at the same time as another conversion, build a 178 * table that does both at once. If just converting case, use the 179 * built-in tables. 180 */ 181 if (ddflags & (C_LCASE|C_UCASE)) 182 if (ddflags & C_ASCII) 183 if (ddflags & C_LCASE) { 184 for (cnt = 0; cnt <= 0377; ++cnt) 185 if (isupper(ctab[cnt])) 186 ctab[cnt] = tolower(ctab[cnt]); 187 } else { 188 for (cnt = 0; cnt <= 0377; ++cnt) 189 if (islower(ctab[cnt])) 190 ctab[cnt] = toupper(ctab[cnt]); 191 } 192 else if (ddflags & C_EBCDIC) 193 if (ddflags & C_LCASE) { 194 for (cnt = 0; cnt <= 0377; ++cnt) 195 if (isupper(cnt)) 196 ctab[cnt] = ctab[tolower(cnt)]; 197 } else { 198 for (cnt = 0; cnt <= 0377; ++cnt) 199 if (islower(cnt)) 200 ctab[cnt] = ctab[toupper(cnt)]; 201 } 202 else { 203 ctab = ddflags & C_LCASE ? u2l : l2u; 204 if (ddflags & C_LCASE) { 205 for (cnt = 0; cnt <= 0377; ++cnt) 206 if (isupper(cnt)) 207 ctab[cnt] = tolower(cnt); 208 else 209 ctab[cnt] = cnt; 210 } else { 211 for (cnt = 0; cnt <= 0377; ++cnt) 212 if (islower(cnt)) 213 ctab[cnt] = toupper(cnt); 214 else 215 ctab[cnt] = cnt; 216 } 217 } 218 (void)gettimeofday(&tv, (struct timezone *)NULL); 219 st.start = tv.tv_sec + tv.tv_usec * 1e-6; 220} 221 222static void 223getfdtype(io) 224 IO *io; 225{ 226 struct mtget mt; 227 struct stat sb; 228 229 if (fstat(io->fd, &sb)) 230 err(1, "%s", io->name); 231 if (S_ISCHR(sb.st_mode)) 232 io->flags |= ioctl(io->fd, MTIOCGET, &mt) ? ISCHR : ISTAPE; 233 else if (lseek(io->fd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) 234 io->flags |= ISPIPE; /* XXX fixed in 4.4BSD */ 235} 236 237static void 238dd_in() 239{ 240 int n; 241 242 for (;;) { 243 if (cpy_cnt && (st.in_full + st.in_part) >= cpy_cnt) 244 return; 245 246 /* 247 * Zero the buffer first if sync; If doing block operations 248 * use spaces. 249 */ 250 if (ddflags & C_SYNC) 251 if (ddflags & (C_BLOCK|C_UNBLOCK)) 252 memset(in.dbp, ' ', in.dbsz); 253 else 254 memset(in.dbp, 0, in.dbsz); 255 256 n = read(in.fd, in.dbp, in.dbsz); 257 if (n == 0) { 258 in.dbrcnt = 0; 259 return; 260 } 261 262 /* Read error. */ 263 if (n < 0) { 264 /* 265 * If noerror not specified, die. POSIX requires that 266 * the warning message be followed by an I/O display. 267 */ 268 if (!(ddflags & C_NOERROR)) 269 err(1, "%s", in.name); 270 warn("%s", in.name); 271 summary(); 272 273 /* 274 * If it's not a tape drive or a pipe, seek past the 275 * error. If your OS doesn't do the right thing for 276 * raw disks this section should be modified to re-read 277 * in sector size chunks. 278 */ 279 if (!(in.flags & (ISPIPE|ISTAPE)) && 280 lseek(in.fd, (off_t)in.dbsz, SEEK_CUR)) 281 warn("%s", in.name); 282 283 /* If sync not specified, omit block and continue. */ 284 if (!(ddflags & C_SYNC)) 285 continue; 286 287 /* Read errors count as full blocks. */ 288 in.dbcnt += in.dbrcnt = in.dbsz; 289 ++st.in_full; 290 291 /* Handle full input blocks. */ 292 } else if (n == in.dbsz) { 293 in.dbcnt += in.dbrcnt = n; 294 ++st.in_full; 295 296 /* Handle partial input blocks. */ 297 } else { 298 /* If sync, use the entire block. */ 299 if (ddflags & C_SYNC) 300 in.dbcnt += in.dbrcnt = in.dbsz; 301 else 302 in.dbcnt += in.dbrcnt = n; 303 ++st.in_part; 304 } 305 306 /* 307 * POSIX states that if bs is set and no other conversions 308 * than noerror, notrunc or sync are specified, the block 309 * is output without buffering as it is read. 310 */ 311 if (ddflags & C_BS) { 312 out.dbcnt = in.dbcnt; 313 dd_out(1); 314 in.dbcnt = 0; 315 continue; 316 } 317 318 if (ddflags & C_SWAB) { 319 if ((n = in.dbrcnt) & 1) { 320 ++st.swab; 321 --n; 322 } 323 swab(in.dbp, in.dbp, n); 324 } 325 326 in.dbp += in.dbrcnt; 327 (*cfunc)(); 328 } 329} 330 331/* 332 * Cleanup any remaining I/O and flush output. If necesssary, output file 333 * is truncated. 334 */ 335static void 336dd_close() 337{ 338 if (cfunc == def) 339 def_close(); 340 else if (cfunc == block) 341 block_close(); 342 else if (cfunc == unblock) 343 unblock_close(); 344 if (ddflags & C_OSYNC && out.dbcnt && out.dbcnt < out.dbsz) { 345 if (ddflags & (C_BLOCK|C_UNBLOCK)) 346 memset(out.dbp, ' ', out.dbsz - out.dbcnt); 347 else 348 memset(out.dbp, 0, out.dbsz - out.dbcnt); 349 out.dbcnt = out.dbsz; 350 } 351 if (out.dbcnt || pending) 352 dd_out(1); 353} 354 355void 356dd_out(force) 357 int force; 358{ 359 static int warned; 360 int cnt, n, nw, i, sparse; 361 u_char *outp; 362 363 /* 364 * Write one or more blocks out. The common case is writing a full 365 * output block in a single write; increment the full block stats. 366 * Otherwise, we're into partial block writes. If a partial write, 367 * and it's a character device, just warn. If a tape device, quit. 368 * 369 * The partial writes represent two cases. 1: Where the input block 370 * was less than expected so the output block was less than expected. 371 * 2: Where the input block was the right size but we were forced to 372 * write the block in multiple chunks. The original versions of dd(1) 373 * never wrote a block in more than a single write, so the latter case 374 * never happened. 375 * 376 * One special case is if we're forced to do the write -- in that case 377 * we play games with the buffer size, and it's usually a partial write. 378 */ 379 outp = out.db; 380 for (n = force ? out.dbcnt : out.dbsz;; n = out.dbsz) { 381 for (cnt = n;; cnt -= nw) { 382 sparse = 0; 383 if (ddflags & C_SPARSE) { 384 sparse = 1; /* Is buffer sparse? */ 385 for (i = 0; i < cnt; i++) 386 if (outp[i] != 0) { 387 sparse = 0; 388 break; 389 } 390 } 391 if (sparse && !force) { 392 pending += cnt; 393 nw = cnt; 394 } else { 395 if (pending != 0) { 396 if (force) 397 pending--; 398 if (lseek (out.fd, pending, SEEK_CUR) == -1) 399 err(2, "%s: seek error creating sparse file", 400 out.name); 401 if (force) 402 write(out.fd, outp, 1); 403 pending = 0; 404 } 405 if (cnt) 406 nw = write(out.fd, outp, cnt); 407 else 408 return; 409 } 410 411 if (nw <= 0) { 412 if (nw == 0) 413 errx(1, "%s: end of device", out.name); 414 if (errno != EINTR) 415 err(1, "%s", out.name); 416 nw = 0; 417 } 418 outp += nw; 419 st.bytes += nw; 420 if (nw == n) { 421 if (n != out.dbsz) 422 ++st.out_part; 423 else 424 ++st.out_full; 425 break; 426 } 427 ++st.out_part; 428 if (nw == cnt) 429 break; 430 if (out.flags & ISCHR && !warned) { 431 warned = 1; 432 warnx("%s: short write on character device", 433 out.name); 434 } 435 if (out.flags & ISTAPE) 436 errx(1, "%s: short write on tape device", out.name); 437 } 438 if ((out.dbcnt -= n) < out.dbsz) 439 break; 440 } 441 442 /* Reassemble the output block. */ 443 if (out.dbcnt) 444 memmove(out.db, out.dbp - out.dbcnt, out.dbcnt); 445 out.dbp = out.db + out.dbcnt; 446} 447