bin/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  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #if 0
  35 #ifndef lint
  36 static char const copyright[] =
  37 "@(#) Copyright (c) 1991, 1993, 1994\n\
  38         The Regents of the University of California.  All rights reserved.\n";
  39 #endif /* not lint */
  40
  41 #ifndef lint
  42 static char sccsid[] = "@(#)dd.c        8.5 (Berkeley) 4/2/94";
  43 #endif /* not lint */
  44 #endif
  45 #include <sys/cdefs.h>
  46 __FBSDID("$FreeBSD$");
  47
  48 #include <sys/param.h>
  49 #include <sys/stat.h>
  50 #include <sys/conf.h>
  51 #include <sys/disklabel.h>
  52 #include <sys/filio.h>
  53 #include <sys/time.h>
  54
  55 #include <ctype.h>
  56 #include <err.h>
  57 #include <errno.h>
  58 #include <fcntl.h>
  59 #include <inttypes.h>
  60 #include <locale.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
  69 static void dd_close(void);
  70 static void dd_in(void);
  71 static void getfdtype(IO *);
  72 static void setup(void);
  73
  74 IO      in, out;                /* input/output state */
  75 STAT    st;                     /* statistics */
  76 void    (*cfunc)(void);         /* conversion function */
  77 uintmax_t cpy_cnt;              /* # of blocks to copy */
  78 static off_t    pending = 0;    /* pending seek if sparse */
  79 u_int   ddflags = 0;            /* conversion options */
  80 size_t  cbsz;                   /* conversion block size */
  81 uintmax_t files_cnt = 1;        /* # of files to copy */
  82 const   u_char *ctab;           /* conversion table */
  83 char    fill_char;              /* Character to fill with if defined */
  84
  85 int
  86 main(int argc __unused, char *argv[])
  87 {
  88         (void)setlocale(LC_CTYPE, "");
  89         jcl(argv);
  90         setup();
  91
  92         (void)signal(SIGINFO, summaryx);
  93         (void)signal(SIGINT, terminate);
  94
  95         atexit(summary);
  96
  97         while (files_cnt--)
  98                 dd_in();
  99
 100         dd_close();
 101         exit(0);
 102 }
 103
 104 static int
 105 parity(u_char c)
 106 {
 107         int i;
 108
 109         i = c ^ (c >> 1) ^ (c >> 2) ^ (c >> 3) ^
 110             (c >> 4) ^ (c >> 5) ^ (c >> 6) ^ (c >> 7);
 111         return (i & 1);
 112 }
 113
 114 static void
 115 setup(void)
 116 {
 117         u_int cnt;
 118         struct timeval tv;
 119
 120         if (in.name == NULL) {
 121                 in.name = "stdin";
 122                 in.fd = STDIN_FILENO;
 123         } else {
 124                 in.fd = open(in.name, O_RDONLY, 0);
 125                 if (in.fd == -1)
 126                         err(1, "%s", in.name);
 127         }
 128
 129         getfdtype(&in);
 130
 131         if (files_cnt > 1 && !(in.flags & ISTAPE))
 132                 errx(1, "files is not supported for non-tape devices");
 133
 134         if (out.name == NULL) {
 135                 /* No way to check for read access here. */
 136                 out.fd = STDOUT_FILENO;
 137                 out.name = "stdout";
 138         } else {
 139 #define OFLAGS \
 140     (O_CREAT | (ddflags & (C_SEEK | C_NOTRUNC) ? 0 : O_TRUNC))
 141                 out.fd = open(out.name, O_RDWR | OFLAGS, DEFFILEMODE);
 142                 /*
 143                  * May not have read access, so try again with write only.
 144                  * Without read we may have a problem if output also does
 145                  * not support seeks.
 146                  */
 147                 if (out.fd == -1) {
 148                         out.fd = open(out.name, O_WRONLY | OFLAGS, DEFFILEMODE);
 149                         out.flags |= NOREAD;
 150                 }
 151                 if (out.fd == -1)
 152                         err(1, "%s", out.name);
 153         }
 154
 155         getfdtype(&out);
 156
 157         /*
 158          * Allocate space for the input and output buffers.  If not doing
 159          * record oriented I/O, only need a single buffer.
 160          */
 161         if (!(ddflags & (C_BLOCK | C_UNBLOCK))) {
 162                 if ((in.db = malloc(out.dbsz + in.dbsz - 1)) == NULL)
 163                         err(1, "input buffer");
 164                 out.db = in.db;
 165         } else if ((in.db = malloc(MAX(in.dbsz, cbsz) + cbsz)) == NULL ||
 166             (out.db = malloc(out.dbsz + cbsz)) == NULL)
 167                 err(1, "output buffer");
 168         in.dbp = in.db;
 169         out.dbp = out.db;
 170
 171         /* Position the input/output streams. */
 172         if (in.offset)
 173                 pos_in();
 174         if (out.offset)
 175                 pos_out();
 176
 177         /*
 178          * Truncate the output file.  If it fails on a type of output file
 179          * that it should _not_ fail on, error out.
 180          */
 181         if ((ddflags & (C_OF | C_SEEK | C_NOTRUNC)) == (C_OF | C_SEEK) &&
 182             out.flags & ISTRUNC)
 183                 if (ftruncate(out.fd, out.offset * out.dbsz) == -1)
 184                         err(1, "truncating %s", out.name);
 185
 186         if (ddflags & (C_LCASE  | C_UCASE | C_ASCII | C_EBCDIC | C_PARITY)) {
 187                 if (ctab != NULL) {
 188                         for (cnt = 0; cnt <= 0377; ++cnt)
 189                                 casetab[cnt] = ctab[cnt];
 190                 } else {
 191                         for (cnt = 0; cnt <= 0377; ++cnt)
 192                                 casetab[cnt] = cnt;
 193                 }
 194                 if ((ddflags & C_PARITY) && !(ddflags & C_ASCII)) {
 195                         /*
 196                          * If the input is not EBCDIC, and we do parity
 197                          * processing, strip input parity.
 198                          */
 199                         for (cnt = 200; cnt <= 0377; ++cnt)
 200                                 casetab[cnt] = casetab[cnt & 0x7f];
 201                 }
 202                 if (ddflags & C_LCASE) {
 203                         for (cnt = 0; cnt <= 0377; ++cnt)
 204                                 casetab[cnt] = tolower(casetab[cnt]);
 205                 } else if (ddflags & C_UCASE) {
 206                         for (cnt = 0; cnt <= 0377; ++cnt)
 207                                 casetab[cnt] = toupper(casetab[cnt]);
 208                 }
 209                 if ((ddflags & C_PARITY)) {
 210                         /*
 211                          * This should strictly speaking be a no-op, but I
 212                          * wonder what funny LANG settings could get us.
 213                          */
 214                         for (cnt = 0; cnt <= 0377; ++cnt)
 215                                 casetab[cnt] = casetab[cnt] & 0x7f;
 216                 }
 217                 if ((ddflags & C_PARSET)) {
 218                         for (cnt = 0; cnt <= 0377; ++cnt)
 219                                 casetab[cnt] = casetab[cnt] | 0x80;
 220                 }
 221                 if ((ddflags & C_PAREVEN)) {
 222                         for (cnt = 0; cnt <= 0377; ++cnt)
 223                                 if (parity(casetab[cnt]))
 224                                         casetab[cnt] = casetab[cnt] | 0x80;
 225                 }
 226                 if ((ddflags & C_PARODD)) {
 227                         for (cnt = 0; cnt <= 0377; ++cnt)
 228                                 if (!parity(casetab[cnt]))
 229                                         casetab[cnt] = casetab[cnt] | 0x80;
 230                 }
 231
 232                 ctab = casetab;
 233         }
 234
 235         (void)gettimeofday(&tv, (struct timezone *)NULL);
 236         st.start = tv.tv_sec + tv.tv_usec * 1e-6;
 237 }
 238
 239 static void
 240 getfdtype(IO *io)
 241 {
 242         struct stat sb;
 243         int type;
 244
 245         if (fstat(io->fd, &sb) == -1)
 246                 err(1, "%s", io->name);
 247         if (S_ISREG(sb.st_mode))
 248                 io->flags |= ISTRUNC;
 249         if (S_ISCHR(sb.st_mode) || S_ISBLK(sb.st_mode)) {
 250                 if (ioctl(io->fd, FIODTYPE, &type) == -1) {
 251                         err(1, "%s", io->name);
 252                 } else {
 253                         if (type & D_TAPE)
 254                                 io->flags |= ISTAPE;
 255                         else if (type & (D_DISK | D_MEM))
 256                                 io->flags |= ISSEEK;
 257                         if (S_ISCHR(sb.st_mode) && (type & D_TAPE) == 0)
 258                                 io->flags |= ISCHR;
 259                 }
 260                 return;
 261         }
 262         errno = 0;
 263         if (lseek(io->fd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE)
 264                 io->flags |= ISPIPE;
 265         else
 266                 io->flags |= ISSEEK;
 267 }
 268
 269 static void
 270 dd_in(void)
 271 {
 272         ssize_t n;
 273
 274         for (;;) {
 275                 switch (cpy_cnt) {
 276                 case -1:                        /* count=0 was specified */
 277                         return;
 278                 case 0:
 279                         break;
 280                 default:
 281                         if (st.in_full + st.in_part >= (uintmax_t)cpy_cnt)
 282                                 return;
 283                         break;
 284                 }
 285
 286                 /*
 287                  * Zero the buffer first if sync; if doing block operations,
 288                  * use spaces.
 289                  */
 290                 if (ddflags & C_SYNC) {
 291                         if (ddflags & C_FILL)
 292                                 memset(in.dbp, fill_char, in.dbsz);
 293                         else if (ddflags & (C_BLOCK | C_UNBLOCK))
 294                                 memset(in.dbp, ' ', in.dbsz);
 295                         else
 296                                 memset(in.dbp, 0, in.dbsz);
 297                 }
 298
 299                 n = read(in.fd, in.dbp, in.dbsz);
 300                 if (n == 0) {
 301                         in.dbrcnt = 0;
 302                         return;
 303                 }
 304
 305                 /* Read error. */
 306                 if (n == -1) {
 307                         /*
 308                          * If noerror not specified, die.  POSIX requires that
 309                          * the warning message be followed by an I/O display.
 310                          */
 311                         if (!(ddflags & C_NOERROR))
 312                                 err(1, "%s", in.name);
 313                         warn("%s", in.name);
 314                         summary();
 315
 316                         /*
 317                          * If it's a seekable file descriptor, seek past the
 318                          * error.  If your OS doesn't do the right thing for
 319                          * raw disks this section should be modified to re-read
 320                          * in sector size chunks.
 321                          */
 322                         if (in.flags & ISSEEK &&
 323                             lseek(in.fd, (off_t)in.dbsz, SEEK_CUR))
 324                                 warn("%s", in.name);
 325
 326                         /* If sync not specified, omit block and continue. */
 327                         if (!(ddflags & C_SYNC))
 328                                 continue;
 329
 330                         /* Read errors count as full blocks. */
 331                         in.dbcnt += in.dbrcnt = in.dbsz;
 332                         ++st.in_full;
 333
 334                 /* Handle full input blocks. */
 335                 } else if ((size_t)n == in.dbsz) {
 336                         in.dbcnt += in.dbrcnt = n;
 337                         ++st.in_full;
 338
 339                 /* Handle partial input blocks. */
 340                 } else {
 341                         /* If sync, use the entire block. */
 342                         if (ddflags & C_SYNC)
 343                                 in.dbcnt += in.dbrcnt = in.dbsz;
 344                         else
 345                                 in.dbcnt += in.dbrcnt = n;
 346                         ++st.in_part;
 347                 }
 348
 349                 /*
 350                  * POSIX states that if bs is set and no other conversions
 351                  * than noerror, notrunc or sync are specified, the block
 352                  * is output without buffering as it is read.
 353                  */
 354                 if ((ddflags & ~(C_NOERROR | C_NOTRUNC | C_SYNC)) == C_BS) {
 355                         out.dbcnt = in.dbcnt;
 356                         dd_out(1);
 357                         in.dbcnt = 0;
 358                         continue;
 359                 }
 360
 361                 if (ddflags & C_SWAB) {
 362                         if ((n = in.dbrcnt) & 1) {
 363                                 ++st.swab;
 364                                 --n;
 365                         }
 366                         swab(in.dbp, in.dbp, (size_t)n);
 367                 }
 368
 369                 in.dbp += in.dbrcnt;
 370                 (*cfunc)();
 371         }
 372 }
 373
 374 /*
 375  * Clean up any remaining I/O and flush output.  If necessary, the output file
 376  * is truncated.
 377  */
 378 static void
 379 dd_close(void)
 380 {
 381         if (cfunc == def)
 382                 def_close();
 383         else if (cfunc == block)
 384                 block_close();
 385         else if (cfunc == unblock)
 386                 unblock_close();
 387         if (ddflags & C_OSYNC && out.dbcnt && out.dbcnt < out.dbsz) {
 388                 if (ddflags & C_FILL)
 389                         memset(out.dbp, fill_char, out.dbsz - out.dbcnt);
 390                 else if (ddflags & (C_BLOCK | C_UNBLOCK))
 391                         memset(out.dbp, ' ', out.dbsz - out.dbcnt);
 392                 else
 393                         memset(out.dbp, 0, out.dbsz - out.dbcnt);
 394                 out.dbcnt = out.dbsz;
 395         }
 396         if (out.dbcnt || pending)
 397                 dd_out(1);
 398 }
 399
 400 void
 401 dd_out(int force)
 402 {
 403         u_char *outp;
 404         size_t cnt, i, n;
 405         ssize_t nw;
 406         static int warned;
 407         int sparse;
 408
 409         /*
 410          * Write one or more blocks out.  The common case is writing a full
 411          * output block in a single write; increment the full block stats.
 412          * Otherwise, we're into partial block writes.  If a partial write,
 413          * and it's a character device, just warn.  If a tape device, quit.
 414          *
 415          * The partial writes represent two cases.  1: Where the input block
 416          * was less than expected so the output block was less than expected.
 417          * 2: Where the input block was the right size but we were forced to
 418          * write the block in multiple chunks.  The original versions of dd(1)
 419          * never wrote a block in more than a single write, so the latter case
 420          * never happened.
 421          *
 422          * One special case is if we're forced to do the write -- in that case
 423          * we play games with the buffer size, and it's usually a partial write.
 424          */
 425         outp = out.db;
 426         for (n = force ? out.dbcnt : out.dbsz;; n = out.dbsz) {
 427                 for (cnt = n;; cnt -= nw) {
 428                         sparse = 0;
 429                         if (ddflags & C_SPARSE) {
 430                                 sparse = 1;     /* Is buffer sparse? */
 431                                 for (i = 0; i < cnt; i++)
 432                                         if (outp[i] != 0) {
 433                                                 sparse = 0;
 434                                                 break;
 435                                         }
 436                         }
 437                         if (sparse && !force) {
 438                                 pending += cnt;
 439                                 nw = cnt;
 440                         } else {
 441                                 if (pending != 0) {
 442                                         if (force)
 443                                                 pending--;
 444                                         if (lseek(out.fd, pending, SEEK_CUR) ==
 445                                             -1)
 446                                                 err(2, "%s: seek error creating sparse file",
 447                                                     out.name);
 448                                         if (force)
 449                                                 write(out.fd, outp, 1);
 450                                         pending = 0;
 451                                 }
 452                                 if (cnt)
 453                                         nw = write(out.fd, outp, cnt);
 454                                 else
 455                                         return;
 456                         }
 457
 458                         if (nw <= 0) {
 459                                 if (nw == 0)
 460                                         errx(1, "%s: end of device", out.name);
 461                                 if (errno != EINTR)
 462                                         err(1, "%s", out.name);
 463                                 nw = 0;
 464                         }
 465                         outp += nw;
 466                         st.bytes += nw;
 467                         if ((size_t)nw == n) {
 468                                 if (n != out.dbsz)
 469                                         ++st.out_part;
 470                                 else
 471                                         ++st.out_full;
 472                                 break;
 473                         }
 474                         ++st.out_part;
 475                         if ((size_t)nw == cnt)
 476                                 break;
 477                         if (out.flags & ISTAPE)
 478                                 errx(1, "%s: short write on tape device",
 479                                     out.name);
 480                         if (out.flags & ISCHR && !warned) {
 481                                 warned = 1;
 482                                 warnx("%s: short write on character device",
 483                                     out.name);
 484                         }
 485                 }
 486                 if ((out.dbcnt -= n) < out.dbsz)
 487                         break;
 488         }
 489
 490         /* Reassemble the output block. */
 491         if (out.dbcnt)
 492                 (void)memmove(out.db, out.dbp - out.dbcnt, out.dbcnt);
 493         out.dbp = out.db + out.dbcnt;
 494 }