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 #include <sys/cdefs.h>
  39 #ifndef lint
  40 __used static char const copyright[] =
  41 "@(#) Copyright (c) 1991, 1993, 1994\n\
  42         The Regents of the University of California.  All rights reserved.\n";
  43 #endif /* not lint */
  44
  45 #ifndef lint
  46 #if 0
  47 static char sccsid[] = "@(#)dd.c        8.5 (Berkeley) 4/2/94";
  48 #endif
  49 __used static const char rcsid[] =
  50   "$FreeBSD: src/bin/dd/dd.c,v 1.36 2002/03/07 14:00:33 markm Exp $";
  51 #endif /* not lint */
  52
  53 #include <sys/param.h>
  54 #include <sys/stat.h>
  55 #include <sys/conf.h>
  56 #include <sys/filio.h>
  57 #include <sys/time.h>
  58
  59 #ifdef __APPLE__
  60 #include <sys/ioctl.h>
  61 #else
  62 #include <sys/disklabel.h>
  63 #endif
  64
  65 #include <ctype.h>
  66 #include <err.h>
  67 #include <errno.h>
  68 #include <fcntl.h>
  69 #include <locale.h>
  70 #include <stdio.h>
  71 #include <stdlib.h>
  72 #include <string.h>
  73 #include <unistd.h>
  74
  75 #include "dd.h"
  76 #include "extern.h"
  77
  78 static void dd_close(void);
  79 static void dd_in(void);
  80 static void getfdtype(IO *);
  81 static void setup(void);
  82
  83 IO      in, out;                /* input/output state */
  84 STAT    st;                     /* statistics */
  85 void    (*cfunc)(void);         /* conversion function */
  86 quad_t  cpy_cnt;                /* # of blocks to copy */
  87 off_t   pending = 0;            /* pending seek if sparse */
  88 u_int   ddflags;                /* conversion options */
  89 size_t  cbsz;                   /* conversion block size */
  90 quad_t  files_cnt = 1;          /* # of files to copy */
  91 const   u_char *ctab;           /* conversion table */
  92
  93 int
  94 main(int argc, char *argv[])
  95 {
  96         (void)setlocale(LC_CTYPE, "");
  97         jcl(argv);
  98         setup();
  99
 100         (void)signal(SIGINFO, summaryx);
 101         (void)signal(SIGINT, terminate);
 102
 103         atexit(summary);
 104
 105         while (files_cnt--)
 106                 dd_in();
 107
 108         dd_close();
 109         exit(0);
 110 }
 111
 112 static void
 113 setup(void)
 114 {
 115         u_int cnt;
 116         struct timeval tv;
 117
 118         if (in.name == NULL) {
 119                 in.name = "stdin";
 120                 in.fd = STDIN_FILENO;
 121         } else {
 122                 in.fd = open(in.name, O_RDONLY, 0);
 123                 if (in.fd == -1)
 124                         err(1, "%s", in.name);
 125         }
 126
 127         getfdtype(&in);
 128
 129         if (files_cnt > 1 && !(in.flags & ISTAPE))
 130                 errx(1, "files is not supported for non-tape devices");
 131
 132         if (out.name == NULL) {
 133                 /* No way to check for read access here. */
 134                 out.fd = STDOUT_FILENO;
 135                 out.name = "stdout";
 136         } else {
 137 #define OFLAGS \
 138     (O_CREAT | (ddflags & (C_SEEK | C_NOTRUNC) ? 0 : O_TRUNC))
 139                 out.fd = open(out.name, O_RDWR | OFLAGS, DEFFILEMODE);
 140                 /*
 141                  * May not have read access, so try again with write only.
 142                  * Without read we may have a problem if output also does
 143                  * not support seeks.
 144                  */
 145                 if (out.fd == -1) {
 146                         out.fd = open(out.name, O_WRONLY | OFLAGS, DEFFILEMODE);
 147                         out.flags |= NOREAD;
 148                 }
 149                 if (out.fd == -1)
 150                         err(1, "%s", out.name);
 151         }
 152
 153         getfdtype(&out);
 154
 155         /*
 156          * Allocate space for the input and output buffers.  If not doing
 157          * record oriented I/O, only need a single buffer.
 158          */
 159         if (!(ddflags & (C_BLOCK | C_UNBLOCK))) {
 160                 if ((in.db = malloc(out.dbsz + in.dbsz - 1)) == NULL)
 161                         err(1, "input buffer");
 162                 out.db = in.db;
 163         } else if ((in.db = malloc(MAX(in.dbsz, cbsz) + cbsz)) == NULL ||
 164             (out.db = malloc(out.dbsz + cbsz)) == NULL)
 165                 err(1, "output buffer");
 166         in.dbp = in.db;
 167         out.dbp = out.db;
 168
 169         /* Position the input/output streams. */
 170         if (in.offset)
 171                 pos_in();
 172         if (out.offset)
 173                 pos_out();
 174
 175         /*
 176          * Truncate the output file.  If it fails on a type of output file
 177          * that it should _not_ fail on, error out.
 178          */
 179         if ((ddflags & (C_OF | C_SEEK | C_NOTRUNC)) == (C_OF | C_SEEK) &&
 180             out.flags & ISTRUNC)
 181                 if (ftruncate(out.fd, out.offset * out.dbsz) == -1)
 182                         err(1, "truncating %s", out.name);
 183
 184         /*
 185          * If converting case at the same time as another conversion, build a
 186          * table that does both at once.  If just converting case, use the
 187          * built-in tables.
 188          */
 189         if (ddflags & (C_LCASE | C_UCASE)) {
 190                 if (ddflags & (C_ASCII | C_EBCDIC)) {
 191                         if (ddflags & C_LCASE) {
 192                                 for (cnt = 0; cnt <= 0377; ++cnt)
 193                                         casetab[cnt] = tolower(ctab[cnt]);
 194                         } else {
 195                                 for (cnt = 0; cnt <= 0377; ++cnt)
 196                                         casetab[cnt] = toupper(ctab[cnt]);
 197                         }
 198                 } else {
 199                         if (ddflags & C_LCASE) {
 200                                 for (cnt = 0; cnt <= 0377; ++cnt)
 201                                         casetab[cnt] = tolower((int)cnt);
 202                         } else {
 203                                 for (cnt = 0; cnt <= 0377; ++cnt)
 204                                         casetab[cnt] = toupper((int)cnt);
 205                         }
 206                 }
 207                 ctab = casetab;
 208         }
 209
 210         (void)gettimeofday(&tv, (struct timezone *)NULL);
 211         st.start = tv.tv_sec + tv.tv_usec * 1e-6;
 212 }
 213
 214 static void
 215 getfdtype(IO *io)
 216 {
 217         struct stat sb;
 218         int type;
 219
 220         if (fstat(io->fd, &sb) == -1)
 221                 err(1, "%s", io->name);
 222         if (S_ISREG(sb.st_mode))
 223                 io->flags |= ISTRUNC;
 224         if (S_ISCHR(sb.st_mode) || S_ISBLK(sb.st_mode)) {
 225                 if (ioctl(io->fd, FIODTYPE, &type) == -1) {
 226                         err(1, "%s", io->name);
 227                 } else {
 228 #ifdef __APPLE__                /* MacOSX uses enumeration for type not a bitmask */
 229                         if (type == D_TAPE)
 230                                 io->flags |= ISTAPE;
 231                         else if (type == D_DISK || type == D_TTY) {
 232 #else  /* !__APPLE__ */
 233                         if (type & D_TAPE)
 234                                 io->flags |= ISTAPE;
 235                         else if (type & (D_DISK | D_MEM)) {
 236                                 if (type & D_DISK) {
 237                                         const int one = 1;
 238
 239                                         (void)ioctl(io->fd, DIOCWLABEL, &one);
 240                                 }
 241 #endif /* __APPLE__ */
 242                                 io->flags |= ISSEEK;
 243                         }
 244 #ifdef __APPLE__
 245                         if (S_ISCHR(sb.st_mode) && (type != D_TAPE))
 246 #else  /* !__APPLE__ */
 247                         if (S_ISCHR(sb.st_mode) && (type & D_TAPE) == 0)
 248 #endif /* __APPLE__ */
 249                                 io->flags |= ISCHR;
 250                 }
 251                 return;
 252         }
 253         errno = 0;
 254         if (lseek(io->fd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE)
 255                 io->flags |= ISPIPE;
 256         else
 257                 io->flags |= ISSEEK;
 258 }
 259
 260 static void
 261 dd_in(void)
 262 {
 263         ssize_t n;
 264
 265         for (;;) {
 266                 switch (cpy_cnt) {
 267                 case -1:                        /* count=0 was specified */
 268                         return;
 269                 case 0:
 270                         break;
 271                 default:
 272                         if (st.in_full + st.in_part >= (u_quad_t)cpy_cnt)
 273                                 return;
 274                         break;
 275                 }
 276
 277                 /*
 278                  * Zero the buffer first if sync; if doing block operations,
 279                  * use spaces.
 280                  */
 281                 if (ddflags & C_SYNC) {
 282                         if (ddflags & (C_BLOCK | C_UNBLOCK))
 283                                 memset(in.dbp, ' ', in.dbsz);
 284                         else
 285                                 memset(in.dbp, 0, in.dbsz);
 286                 }
 287
 288                 n = read(in.fd, in.dbp, in.dbsz);
 289                 if (n == 0) {
 290                         in.dbrcnt = 0;
 291                         return;
 292                 }
 293
 294                 /* Read error. */
 295                 if (n == -1) {
 296                         /*
 297                          * If noerror not specified, die.  POSIX requires that
 298                          * the warning message be followed by an I/O display.
 299                          */
 300                         if (!(ddflags & C_NOERROR))
 301                                 err(1, "%s", in.name);
 302                         warn("%s", in.name);
 303                         summary();
 304
 305                         /*
 306                          * If it's a seekable file descriptor, seek past the
 307                          * error.  If your OS doesn't do the right thing for
 308                          * raw disks this section should be modified to re-read
 309                          * in sector size chunks.
 310                          */
 311                         if (in.flags & ISSEEK &&
 312                             lseek(in.fd, (off_t)in.dbsz, SEEK_CUR))
 313                                 warn("%s", in.name);
 314
 315                         /* If sync not specified, omit block and continue. */
 316                         if (!(ddflags & C_SYNC))
 317                                 continue;
 318
 319                         /* Read errors count as full blocks. */
 320                         in.dbcnt += in.dbrcnt = in.dbsz;
 321                         ++st.in_full;
 322
 323                 /* Handle full input blocks. */
 324                 } else if ((size_t)n == in.dbsz) {
 325                         in.dbcnt += in.dbrcnt = n;
 326                         ++st.in_full;
 327
 328                 /* Handle partial input blocks. */
 329                 } else {
 330                         /* If sync, use the entire block. */
 331                         if (ddflags & C_SYNC)
 332                                 in.dbcnt += in.dbrcnt = in.dbsz;
 333                         else
 334                                 in.dbcnt += in.dbrcnt = n;
 335                         ++st.in_part;
 336                 }
 337
 338                 /*
 339                  * POSIX states that if bs is set and no other conversions
 340                  * than noerror, notrunc or sync are specified, the block
 341                  * is output without buffering as it is read.
 342                  */
 343                 if (ddflags & C_BS) {
 344                         out.dbcnt = in.dbcnt;
 345                         dd_out(1);
 346                         in.dbcnt = 0;
 347                         continue;
 348                 }
 349
 350                 if (ddflags & C_SWAB) {
 351                         if ((n = in.dbrcnt) & 1) {
 352                                 ++st.swab;
 353                                 --n;
 354                         }
 355                         swab(in.dbp, in.dbp, (size_t)n);
 356                 }
 357
 358                 in.dbp += in.dbrcnt;
 359                 (*cfunc)();
 360         }
 361 }
 362
 363 /*
 364  * Clean up any remaining I/O and flush output.  If necessary, the output file
 365  * is truncated.
 366  */
 367 static void
 368 dd_close(void)
 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.dbcnt < out.dbsz) {
 377                 if (ddflags & (C_BLOCK | C_UNBLOCK))
 378                         memset(out.dbp, ' ', out.dbsz - out.dbcnt);
 379                 else
 380                         memset(out.dbp, 0, out.dbsz - out.dbcnt);
 381                 out.dbcnt = out.dbsz;
 382         }
 383         if (out.dbcnt || pending)
 384                 dd_out(1);
 385 }
 386
 387 void
 388 dd_out(int force)
 389 {
 390         u_char *outp;
 391         size_t cnt, i, n;
 392         ssize_t nw;
 393         static int warned;
 394         int sparse;
 395
 396         /*
 397          * Write one or more blocks out.  The common case is writing a full
 398          * output block in a single write; increment the full block stats.
 399          * Otherwise, we're into partial block writes.  If a partial write,
 400          * and it's a character device, just warn.  If a tape device, quit.
 401          *
 402          * The partial writes represent two cases.  1: Where the input block
 403          * was less than expected so the output block was less than expected.
 404          * 2: Where the input block was the right size but we were forced to
 405          * write the block in multiple chunks.  The original versions of dd(1)
 406          * never wrote a block in more than a single write, so the latter case
 407          * never happened.
 408          *
 409          * One special case is if we're forced to do the write -- in that case
 410          * we play games with the buffer size, and it's usually a partial write.
 411          */
 412         outp = out.db;
 413         for (n = force ? out.dbcnt : out.dbsz;; n = out.dbsz) {
 414                 for (cnt = n;; cnt -= nw) {
 415                         sparse = 0;
 416                         if (ddflags & C_SPARSE) {
 417                                 sparse = 1;     /* Is buffer sparse? */
 418                                 for (i = 0; i < cnt; i++)
 419                                         if (outp[i] != 0) {
 420                                                 sparse = 0;
 421                                                 break;
 422                                         }
 423                         }
 424                         if (sparse && !force) {
 425                                 pending += cnt;
 426                                 nw = cnt;
 427                         } else {
 428                                 if (pending != 0) {
 429                                         if (force)
 430                                                 pending--;
 431                                         if (lseek(out.fd, pending, SEEK_CUR) ==
 432                                             -1)
 433                                                 err(2, "%s: seek error creating sparse file",
 434                                                     out.name);
 435                                         if (force)
 436                                                 write(out.fd, outp, 1);
 437                                         pending = 0;
 438                                 }
 439                                 if (cnt)
 440                                         nw = write(out.fd, outp, cnt);
 441                                 else
 442                                         return;
 443                         }
 444
 445                         if (nw <= 0) {
 446                                 if (nw == 0)
 447                                         errx(1, "%s: end of device", out.name);
 448                                 if (errno != EINTR)
 449                                         err(1, "%s", out.name);
 450                                 nw = 0;
 451                         }
 452                         outp += nw;
 453                         st.bytes += nw;
 454                         if ((size_t)nw == n) {
 455                                 if (n != out.dbsz)
 456                                         ++st.out_part;
 457                                 else
 458                                         ++st.out_full;
 459                                 break;
 460                         }
 461                         ++st.out_part;
 462                         if ((size_t)nw == cnt)
 463                                 break;
 464                         if (out.flags & ISTAPE)
 465                                 errx(1, "%s: short write on tape device",
 466                                     out.name);
 467                         if (out.flags & ISCHR && !warned) {
 468                                 warned = 1;
 469                                 warnx("%s: short write on character device",
 470                                     out.name);
 471                         }
 472                 }
 473                 if ((out.dbcnt -= n) < out.dbsz)
 474                         break;
 475         }
 476
 477         /* Reassemble the output block. */
 478         if (out.dbcnt)
 479                 (void)memmove(out.db, out.dbp - out.dbcnt, out.dbcnt);
 480         out.dbp = out.db + out.dbcnt;
 481 }