dd/dd.c

   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
  39 static 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
  46 static char sccsid[] = "@(#)dd.c        8.5 (Berkeley) 4/2/94";
  47 #endif
  48 static const char rcsid[] =
  49   "$FreeBSD: src/bin/dd/dd.c,v 1.36 2002/03/07 14:00:33 markm Exp $";
  50 #endif /* not lint */
  51
  52 #include <sys/param.h>
  53 #include <sys/stat.h>
  54 #include <sys/conf.h>
  55 #include <sys/filio.h>
  56 #include <sys/time.h>
  57
  58 #ifdef __APPLE__
  59 #include <sys/ioctl.h>
  60 #else
  61 #include <sys/disklabel.h>
  62 #endif
  63
  64 #include <ctype.h>
  65 #include <err.h>
  66 #include <errno.h>
  67 #include <fcntl.h>
  68 #include <locale.h>
  69 #include <stdio.h>
  70 #include <stdlib.h>
  71 #include <string.h>
  72 #include <unistd.h>
  73
  74 #include "dd.h"
  75 #include "extern.h"
  76
  77 static void dd_close(void);
  78 static void dd_in(void);
  79 static void getfdtype(IO *);
  80 static void setup(void);
  81
  82 IO      in, out;                /* input/output state */
  83 STAT    st;                     /* statistics */
  84 void    (*cfunc)(void);         /* conversion function */
  85 quad_t  cpy_cnt;                /* # of blocks to copy */
  86 off_t   pending = 0;            /* pending seek if sparse */
  87 u_int   ddflags;                /* conversion options */
  88 size_t  cbsz;                   /* conversion block size */
  89 quad_t  files_cnt = 1;          /* # of files to copy */
  90 const   u_char *ctab;           /* conversion table */
  91
  92 int
  93 main(int argc, char *argv[])
  94 {
  95         (void)setlocale(LC_CTYPE, "");
  96         jcl(argv);
  97         setup();
  98
  99         (void)signal(SIGINFO, summaryx);
 100         (void)signal(SIGINT, terminate);
 101
 102         atexit(summary);
 103
 104         while (files_cnt--)
 105                 dd_in();
 106
 107         dd_close();
 108         exit(0);
 109 }
 110
 111 static void
 112 setup(void)
 113 {
 114         u_int cnt;
 115         struct timeval tv;
 116
 117         if (in.name == NULL) {
 118                 in.name = "stdin";
 119                 in.fd = STDIN_FILENO;
 120         } else {
 121                 in.fd = open(in.name, O_RDONLY, 0);
 122                 if (in.fd == -1)
 123                         err(1, "%s", in.name);
 124         }
 125
 126         getfdtype(&in);
 127
 128         if (files_cnt > 1 && !(in.flags & ISTAPE))
 129                 errx(1, "files is not supported for non-tape devices");
 130
 131         if (out.name == NULL) {
 132                 /* No way to check for read access here. */
 133                 out.fd = STDOUT_FILENO;
 134                 out.name = "stdout";
 135         } else {
 136 #define OFLAGS \
 137     (O_CREAT | (ddflags & (C_SEEK | C_NOTRUNC) ? 0 : O_TRUNC))
 138                 out.fd = open(out.name, O_RDWR | OFLAGS, DEFFILEMODE);
 139                 /*
 140                  * May not have read access, so try again with write only.
 141                  * Without read we may have a problem if output also does
 142                  * not support seeks.
 143                  */
 144                 if (out.fd == -1) {
 145                         out.fd = open(out.name, O_WRONLY | OFLAGS, DEFFILEMODE);
 146                         out.flags |= NOREAD;
 147                 }
 148                 if (out.fd == -1)
 149                         err(1, "%s", out.name);
 150         }
 151
 152         getfdtype(&out);
 153
 154         /*
 155          * Allocate space for the input and output buffers.  If not doing
 156          * record oriented I/O, only need a single buffer.
 157          */
 158         if (!(ddflags & (C_BLOCK | C_UNBLOCK))) {
 159                 if ((in.db = malloc(out.dbsz + in.dbsz - 1)) == NULL)
 160                         err(1, "input buffer");
 161                 out.db = in.db;
 162         } else if ((in.db = malloc(MAX(in.dbsz, cbsz) + cbsz)) == NULL ||
 163             (out.db = malloc(out.dbsz + cbsz)) == NULL)
 164                 err(1, "output buffer");
 165         in.dbp = in.db;
 166         out.dbp = out.db;
 167
 168         /* Position the input/output streams. */
 169         if (in.offset)
 170                 pos_in();
 171         if (out.offset)
 172                 pos_out();
 173
 174         /*
 175          * Truncate the output file.  If it fails on a type of output file
 176          * that it should _not_ fail on, error out.
 177          */
 178         if ((ddflags & (C_OF | C_SEEK | C_NOTRUNC)) == (C_OF | C_SEEK) &&
 179             out.flags & ISTRUNC)
 180                 if (ftruncate(out.fd, out.offset * out.dbsz) == -1)
 181                         err(1, "truncating %s", out.name);
 182
 183         /*
 184          * If converting case at the same time as another conversion, build a
 185          * table that does both at once.  If just converting case, use the
 186          * built-in tables.
 187          */
 188         if (ddflags & (C_LCASE | C_UCASE)) {
 189                 if (ddflags & (C_ASCII | C_EBCDIC)) {
 190                         if (ddflags & C_LCASE) {
 191                                 for (cnt = 0; cnt <= 0377; ++cnt)
 192                                         casetab[cnt] = tolower(ctab[cnt]);
 193                         } else {
 194                                 for (cnt = 0; cnt <= 0377; ++cnt)
 195                                         casetab[cnt] = toupper(ctab[cnt]);
 196                         }
 197                 } else {
 198                         if (ddflags & C_LCASE) {
 199                                 for (cnt = 0; cnt <= 0377; ++cnt)
 200                                         casetab[cnt] = tolower((int)cnt);
 201                         } else {
 202                                 for (cnt = 0; cnt <= 0377; ++cnt)
 203                                         casetab[cnt] = toupper((int)cnt);
 204                         }
 205                 }
 206                 ctab = casetab;
 207         }
 208
 209         (void)gettimeofday(&tv, (struct timezone *)NULL);
 210         st.start = tv.tv_sec + tv.tv_usec * 1e-6;
 211 }
 212
 213 static void
 214 getfdtype(IO *io)
 215 {
 216         struct stat sb;
 217         int type;
 218
 219         if (fstat(io->fd, &sb) == -1)
 220                 err(1, "%s", io->name);
 221         if (S_ISREG(sb.st_mode))
 222                 io->flags |= ISTRUNC;
 223         if (S_ISCHR(sb.st_mode) || S_ISBLK(sb.st_mode)) {
 224                 if (ioctl(io->fd, FIODTYPE, &type) == -1) {
 225                         err(1, "%s", io->name);
 226                 } else {
 227                         if (type & D_TAPE)
 228                                 io->flags |= ISTAPE;
 229 #ifdef __APPLE__
 230                         else if (type & D_DISK) {
 231 #else
 232                         else if (type & (D_DISK | D_MEM)) {
 233                                 if (type & D_DISK) {
 234                                         const int one = 1;
 235
 236                                         (void)ioctl(io->fd, DIOCWLABEL, &one);
 237                                 }
 238 #endif
 239                                 io->flags |= ISSEEK;
 240                         }
 241                         if (S_ISCHR(sb.st_mode) && (type & D_TAPE) == 0)
 242                                 io->flags |= ISCHR;
 243                 }
 244                 return;
 245         }
 246         errno = 0;
 247         if (lseek(io->fd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE)
 248                 io->flags |= ISPIPE;
 249         else
 250                 io->flags |= ISSEEK;
 251 }
 252
 253 static void
 254 dd_in(void)
 255 {
 256         ssize_t n;
 257
 258         for (;;) {
 259                 switch (cpy_cnt) {
 260                 case -1:                        /* count=0 was specified */
 261                         return;
 262                 case 0:
 263                         break;
 264                 default:
 265                         if (st.in_full + st.in_part >= (u_quad_t)cpy_cnt)
 266                                 return;
 267                         break;
 268                 }
 269
 270                 /*
 271                  * Zero the buffer first if sync; if doing block operations,
 272                  * use spaces.
 273                  */
 274                 if (ddflags & C_SYNC) {
 275                         if (ddflags & (C_BLOCK | C_UNBLOCK))
 276                                 memset(in.dbp, ' ', in.dbsz);
 277                         else
 278                                 memset(in.dbp, 0, in.dbsz);
 279                 }
 280
 281                 n = read(in.fd, in.dbp, in.dbsz);
 282                 if (n == 0) {
 283                         in.dbrcnt = 0;
 284                         return;
 285                 }
 286
 287                 /* Read error. */
 288                 if (n == -1) {
 289                         /*
 290                          * If noerror not specified, die.  POSIX requires that
 291                          * the warning message be followed by an I/O display.
 292                          */
 293                         if (!(ddflags & C_NOERROR))
 294                                 err(1, "%s", in.name);
 295                         warn("%s", in.name);
 296                         summary();
 297
 298                         /*
 299                          * If it's a seekable file descriptor, 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 & ISSEEK &&
 305                             lseek(in.fd, (off_t)in.dbsz, SEEK_CUR))
 306                                 warn("%s", in.name);
 307
 308                         /* If sync not specified, omit block and continue. */
 309                         if (!(ddflags & C_SYNC))
 310                                 continue;
 311
 312                         /* Read errors count as full blocks. */
 313                         in.dbcnt += in.dbrcnt = in.dbsz;
 314                         ++st.in_full;
 315
 316                 /* Handle full input blocks. */
 317                 } else if ((size_t)n == in.dbsz) {
 318                         in.dbcnt += in.dbrcnt = n;
 319                         ++st.in_full;
 320
 321                 /* Handle partial input blocks. */
 322                 } else {
 323                         /* If sync, use the entire block. */
 324                         if (ddflags & C_SYNC)
 325                                 in.dbcnt += in.dbrcnt = in.dbsz;
 326                         else
 327                                 in.dbcnt += in.dbrcnt = n;
 328                         ++st.in_part;
 329                 }
 330
 331                 /*
 332                  * POSIX states that if bs is set and no other conversions
 333                  * than noerror, notrunc or sync are specified, the block
 334                  * is output without buffering as it is read.
 335                  */
 336                 if (ddflags & C_BS) {
 337                         out.dbcnt = in.dbcnt;
 338                         dd_out(1);
 339                         in.dbcnt = 0;
 340                         continue;
 341                 }
 342
 343                 if (ddflags & C_SWAB) {
 344                         if ((n = in.dbrcnt) & 1) {
 345                                 ++st.swab;
 346                                 --n;
 347                         }
 348                         swab(in.dbp, in.dbp, (size_t)n);
 349                 }
 350
 351                 in.dbp += in.dbrcnt;
 352                 (*cfunc)();
 353         }
 354 }
 355
 356 /*
 357  * Clean up any remaining I/O and flush output.  If necessary, the output file
 358  * is truncated.
 359  */
 360 static void
 361 dd_close(void)
 362 {
 363         if (cfunc == def)
 364                 def_close();
 365         else if (cfunc == block)
 366                 block_close();
 367         else if (cfunc == unblock)
 368                 unblock_close();
 369         if (ddflags & C_OSYNC && out.dbcnt && out.dbcnt < out.dbsz) {
 370                 if (ddflags & (C_BLOCK | C_UNBLOCK))
 371                         memset(out.dbp, ' ', out.dbsz - out.dbcnt);
 372                 else
 373                         memset(out.dbp, 0, out.dbsz - out.dbcnt);
 374                 out.dbcnt = out.dbsz;
 375         }
 376         if (out.dbcnt || pending)
 377                 dd_out(1);
 378 }
 379
 380 void
 381 dd_out(int force)
 382 {
 383         u_char *outp;
 384         size_t cnt, i, n;
 385         ssize_t nw;
 386         static int warned;
 387         int sparse;
 388
 389         /*
 390          * Write one or more blocks out.  The common case is writing a full
 391          * output block in a single write; increment the full block stats.
 392          * Otherwise, we're into partial block writes.  If a partial write,
 393          * and it's a character device, just warn.  If a tape device, quit.
 394          *
 395          * The partial writes represent two cases.  1: Where the input block
 396          * was less than expected so the output block was less than expected.
 397          * 2: Where the input block was the right size but we were forced to
 398          * write the block in multiple chunks.  The original versions of dd(1)
 399          * never wrote a block in more than a single write, so the latter case
 400          * never happened.
 401          *
 402          * One special case is if we're forced to do the write -- in that case
 403          * we play games with the buffer size, and it's usually a partial write.
 404          */
 405         outp = out.db;
 406         for (n = force ? out.dbcnt : out.dbsz;; n = out.dbsz) {
 407                 for (cnt = n;; cnt -= nw) {
 408                         sparse = 0;
 409                         if (ddflags & C_SPARSE) {
 410                                 sparse = 1;     /* Is buffer sparse? */
 411                                 for (i = 0; i < cnt; i++)
 412                                         if (outp[i] != 0) {
 413                                                 sparse = 0;
 414                                                 break;
 415                                         }
 416                         }
 417                         if (sparse && !force) {
 418                                 pending += cnt;
 419                                 nw = cnt;
 420                         } else {
 421                                 if (pending != 0) {
 422                                         if (force)
 423                                                 pending--;
 424                                         if (lseek(out.fd, pending, SEEK_CUR) ==
 425                                             -1)
 426                                                 err(2, "%s: seek error creating sparse file",
 427                                                     out.name);
 428                                         if (force)
 429                                                 write(out.fd, outp, 1);
 430                                         pending = 0;
 431                                 }
 432                                 if (cnt)
 433                                         nw = write(out.fd, outp, cnt);
 434                                 else
 435                                         return;
 436                         }
 437
 438                         if (nw <= 0) {
 439                                 if (nw == 0)
 440                                         errx(1, "%s: end of device", out.name);
 441                                 if (errno != EINTR)
 442                                         err(1, "%s", out.name);
 443                                 nw = 0;
 444                         }
 445                         outp += nw;
 446                         st.bytes += nw;
 447                         if ((size_t)nw == n) {
 448                                 if (n != out.dbsz)
 449                                         ++st.out_part;
 450                                 else
 451                                         ++st.out_full;
 452                                 break;
 453                         }
 454                         ++st.out_part;
 455                         if ((size_t)nw == cnt)
 456                                 break;
 457                         if (out.flags & ISTAPE)
 458                                 errx(1, "%s: short write on tape device",
 459                                     out.name);
 460                         if (out.flags & ISCHR && !warned) {
 461                                 warned = 1;
 462                                 warnx("%s: short write on character device",
 463                                     out.name);
 464                         }
 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 }