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  * 3. 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  * @(#) Copyright (c) 1991, 1993, 1994 The Regents of the University of California.  All rights reserved.
  34  * @(#)dd.c     8.5 (Berkeley) 4/2/94
  35  * $FreeBSD: src/bin/dd/dd.c,v 1.27.2.3 2001/08/01 01:37:35 obrien Exp $
  36  * $DragonFly: src/bin/dd/dd.c,v 1.9 2008/01/28 16:08:02 matthias Exp $
  37  */
  38
  39 #include <sys/param.h>
  40 #include <sys/stat.h>
  41 #include <sys/conf.h>
  42 #include <sys/device.h>
  43 #include <sys/filio.h>
  44 #include <sys/time.h>
  45
  46 #include <ctype.h>
  47 #include <err.h>
  48 #include <errno.h>
  49 #include <fcntl.h>
  50 #include <locale.h>
  51 #include <stdio.h>
  52 #include <stdlib.h>
  53 #include <string.h>
  54 #include <unistd.h>
  55
  56 #include "dd.h"
  57 #include "extern.h"
  58
  59 static void dd_close (void);
  60 static void dd_in (void);
  61 int main (int, char *[]);
  62 static void getfdtype (IO *);
  63 static void setup (void);
  64
  65 IO      in, out;                /* input/output state */
  66 STAT    st;                     /* statistics */
  67 void    (*cfunc) (void);        /* conversion function */
  68 quad_t  cpy_cnt;                /* # of blocks to copy */
  69 off_t   pending = 0;            /* pending seek if sparse */
  70 u_int   ddflags;                /* conversion options */
  71 size_t  cbsz;                   /* conversion block size */
  72 quad_t  files_cnt = 1;          /* # of files to copy */
  73 const   u_char *ctab;           /* conversion table */
  74
  75 int
  76 main(int argc __unused, char **argv)
  77 {
  78         setlocale(LC_CTYPE, "");
  79         jcl(argv);
  80         setup();
  81
  82         signal(SIGINFO, summaryx);
  83         signal(SIGINT, terminate);
  84
  85         atexit(summary);
  86
  87         while (files_cnt--)
  88                 dd_in();
  89
  90         dd_close();
  91         exit(0);
  92 }
  93
  94 static void
  95 setup(void)
  96 {
  97         u_int cnt;
  98         struct timeval tv;
  99
 100         if (in.name == NULL) {
 101                 in.name = "stdin";
 102                 in.fd = STDIN_FILENO;
 103         } else {
 104                 in.fd = open(in.name, O_RDONLY, 0);
 105                 if (in.fd == -1)
 106                         err(1, "%s", in.name);
 107         }
 108
 109         getfdtype(&in);
 110
 111         if (files_cnt > 1 && !(in.flags & ISTAPE))
 112                 errx(1, "files is not supported for non-tape devices");
 113
 114         if (out.name == NULL) {
 115                 /* No way to check for read access here. */
 116                 out.fd = STDOUT_FILENO;
 117                 out.name = "stdout";
 118         } else {
 119 #define OFLAGS \
 120     (O_CREAT | (ddflags & (C_SEEK | C_NOTRUNC) ? 0 : O_TRUNC))
 121                 out.fd = open(out.name, O_RDWR | OFLAGS, DEFFILEMODE);
 122                 /*
 123                  * May not have read access, so try again with write only.
 124                  * Without read we may have a problem if output also does
 125                  * not support seeks.
 126                  */
 127                 if (out.fd == -1) {
 128                         out.fd = open(out.name, O_WRONLY | OFLAGS, DEFFILEMODE);
 129                         out.flags |= NOREAD;
 130                 }
 131                 if (out.fd == -1)
 132                         err(1, "%s", out.name);
 133         }
 134
 135         getfdtype(&out);
 136
 137         /*
 138          * Allocate space for the input and output buffers.  If not doing
 139          * record oriented I/O, only need a single buffer.
 140          */
 141         if (!(ddflags & (C_BLOCK | C_UNBLOCK))) {
 142                 if ((in.db = malloc(out.dbsz + in.dbsz - 1)) == NULL)
 143                         err(1, "input buffer");
 144                 out.db = in.db;
 145         } else if ((in.db = malloc(MAX(in.dbsz, cbsz) + cbsz)) == NULL ||
 146             (out.db = malloc(out.dbsz + cbsz)) == NULL)
 147                 err(1, "output buffer");
 148         in.dbp = in.db;
 149         out.dbp = out.db;
 150
 151         /* Position the input/output streams. */
 152         if (in.offset)
 153                 pos_in();
 154         if (out.offset)
 155                 pos_out();
 156
 157         /*
 158          * Truncate the output file.  If it fails on a type of output file
 159          * that it should _not_ fail on, error out.
 160          */
 161         if ((ddflags & (C_OF | C_SEEK | C_NOTRUNC)) == (C_OF | C_SEEK) &&
 162             out.flags & ISTRUNC)
 163                 if (ftruncate(out.fd, out.offset * out.dbsz) == -1)
 164                         err(1, "truncating %s", out.name);
 165
 166         /*
 167          * If converting case at the same time as another conversion, build a
 168          * table that does both at once.  If just converting case, use the
 169          * built-in tables.
 170          */
 171         if (ddflags & (C_LCASE | C_UCASE)) {
 172                 if (ddflags & (C_ASCII | C_EBCDIC)) {
 173                         if (ddflags & C_LCASE) {
 174                                 for (cnt = 0; cnt <= 0377; ++cnt)
 175                                         casetab[cnt] = tolower(ctab[cnt]);
 176                         } else {
 177                                 for (cnt = 0; cnt <= 0377; ++cnt)
 178                                         casetab[cnt] = toupper(ctab[cnt]);
 179                         }
 180                 } else {
 181                         if (ddflags & C_LCASE) {
 182                                 for (cnt = 0; cnt <= 0377; ++cnt)
 183                                         casetab[cnt] = tolower((int)cnt);
 184                         } else {
 185                                 for (cnt = 0; cnt <= 0377; ++cnt)
 186                                         casetab[cnt] = toupper((int)cnt);
 187                         }
 188                 }
 189                 ctab = casetab;
 190         }
 191
 192         gettimeofday(&tv, (struct timezone *)NULL);
 193         st.start = tv.tv_sec + tv.tv_usec * 1e-6;
 194 }
 195
 196 static void
 197 getfdtype(IO *io)
 198 {
 199         struct stat sb;
 200         int type;
 201
 202         if (fstat(io->fd, &sb) == -1)
 203                 err(1, "%s", io->name);
 204         if (S_ISREG(sb.st_mode))
 205                 io->flags |= ISTRUNC;
 206         if (S_ISCHR(sb.st_mode) || S_ISBLK(sb.st_mode)) {
 207                 if (ioctl(io->fd, FIODTYPE, &type) == -1) {
 208                         err(1, "%s", io->name);
 209                 } else {
 210                         if (type & D_TAPE)
 211                                 io->flags |= ISTAPE;
 212                         else if (type & (D_DISK | D_MEM))
 213                                 io->flags |= ISSEEK;
 214                         if (S_ISCHR(sb.st_mode) && (type & D_TAPE) == 0)
 215                                 io->flags |= ISCHR;
 216                 }
 217                 return;
 218         }
 219         errno = 0;
 220         if (lseek(io->fd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE)
 221                 io->flags |= ISPIPE;
 222         else
 223                 io->flags |= ISSEEK;
 224 }
 225
 226 static void
 227 dd_in(void)
 228 {
 229         ssize_t n;
 230
 231         for (;;) {
 232                 switch (cpy_cnt) {
 233                 case -1:                        /* count=0 was specified */
 234                         return;
 235                 case 0:
 236                         break;
 237                 default:
 238                         if (st.in_full + st.in_part >= (u_quad_t)cpy_cnt)
 239                                 return;
 240                         break;
 241                 }
 242
 243                 /*
 244                  * Zero the buffer first if sync; if doing block operations,
 245                  * use spaces.
 246                  */
 247                 if (ddflags & C_SYNC) {
 248                         if (ddflags & (C_BLOCK | C_UNBLOCK))
 249                                 memset(in.dbp, ' ', in.dbsz);
 250                         else
 251                                 memset(in.dbp, 0, in.dbsz);
 252                 }
 253
 254                 n = read(in.fd, in.dbp, in.dbsz);
 255                 if (n == 0) {
 256                         in.dbrcnt = 0;
 257                         return;
 258                 }
 259
 260                 /* Read error. */
 261                 if (n == -1) {
 262                         /*
 263                          * If noerror not specified, die.  POSIX requires that
 264                          * the warning message be followed by an I/O display.
 265                          */
 266                         if (!(ddflags & C_NOERROR))
 267                                 err(1, "%s", in.name);
 268                         warn("%s", in.name);
 269                         summary();
 270
 271                         /*
 272                          * If it's a seekable file descriptor, seek past the
 273                          * error.  If your OS doesn't do the right thing for
 274                          * raw disks this section should be modified to re-read
 275                          * in sector size chunks.
 276                          */
 277                         if (in.flags & ISSEEK &&
 278                             lseek(in.fd, (off_t)in.dbsz, SEEK_CUR))
 279                                 warn("%s", in.name);
 280
 281                         /* If sync not specified, omit block and continue. */
 282                         if (!(ddflags & C_SYNC))
 283                                 continue;
 284
 285                         /* Read errors count as full blocks. */
 286                         in.dbcnt += in.dbrcnt = in.dbsz;
 287                         ++st.in_full;
 288
 289                 /* Handle full input blocks. */
 290                 } else if ((size_t)n == in.dbsz) {
 291                         in.dbcnt += in.dbrcnt = n;
 292                         ++st.in_full;
 293
 294                 /* Handle partial input blocks. */
 295                 } else {
 296                         /* If sync, use the entire block. */
 297                         if (ddflags & C_SYNC)
 298                                 in.dbcnt += in.dbrcnt = in.dbsz;
 299                         else
 300                                 in.dbcnt += in.dbrcnt = n;
 301                         ++st.in_part;
 302                 }
 303
 304                 /*
 305                  * POSIX states that if bs is set and no other conversions
 306                  * than noerror, notrunc or sync are specified, the block
 307                  * is output without buffering as it is read.
 308                  */
 309                 if (ddflags & C_BS) {
 310                         out.dbcnt = in.dbcnt;
 311                         dd_out(1);
 312                         in.dbcnt = 0;
 313                         continue;
 314                 }
 315
 316                 if (ddflags & C_SWAB) {
 317                         if ((n = in.dbrcnt) & 1) {
 318                                 ++st.swab;
 319                                 --n;
 320                         }
 321                         swab(in.dbp, in.dbp, (size_t)n);
 322                 }
 323
 324                 in.dbp += in.dbrcnt;
 325                 (*cfunc)();
 326         }
 327 }
 328
 329 /*
 330  * Clean up any remaining I/O and flush output.  If necessary, the output file
 331  * is truncated.
 332  */
 333 static void
 334 dd_close(void)
 335 {
 336         if (cfunc == def)
 337                 def_close();
 338         else if (cfunc == block)
 339                 block_close();
 340         else if (cfunc == unblock)
 341                 unblock_close();
 342         if (ddflags & C_OSYNC && out.dbcnt && out.dbcnt < out.dbsz) {
 343                 if (ddflags & (C_BLOCK | C_UNBLOCK))
 344                         memset(out.dbp, ' ', out.dbsz - out.dbcnt);
 345                 else
 346                         memset(out.dbp, 0, out.dbsz - out.dbcnt);
 347                 out.dbcnt = out.dbsz;
 348         }
 349         if (out.dbcnt || pending)
 350                 dd_out(1);
 351 }
 352
 353 void
 354 dd_out(int force)
 355 {
 356         u_char *outp;
 357         size_t cnt, i, n;
 358         ssize_t nw;
 359         static int warned;
 360         int sparse;
 361
 362         /*
 363          * Write one or more blocks out.  The common case is writing a full
 364          * output block in a single write; increment the full block stats.
 365          * Otherwise, we're into partial block writes.  If a partial write,
 366          * and it's a character device, just warn.  If a tape device, quit.
 367          *
 368          * The partial writes represent two cases.  1: Where the input block
 369          * was less than expected so the output block was less than expected.
 370          * 2: Where the input block was the right size but we were forced to
 371          * write the block in multiple chunks.  The original versions of dd(1)
 372          * never wrote a block in more than a single write, so the latter case
 373          * never happened.
 374          *
 375          * One special case is if we're forced to do the write -- in that case
 376          * we play games with the buffer size, and it's usually a partial write.
 377          */
 378         outp = out.db;
 379         for (n = force ? out.dbcnt : out.dbsz;; n = out.dbsz) {
 380                 for (cnt = n;; cnt -= nw) {
 381                         sparse = 0;
 382                         if (ddflags & C_SPARSE) {
 383                                 sparse = 1;     /* Is buffer sparse? */
 384                                 for (i = 0; i < cnt; i++)
 385                                         if (outp[i] != 0) {
 386                                                 sparse = 0;
 387                                                 break;
 388                                         }
 389                         }
 390                         if (sparse && !force) {
 391                                 pending += cnt;
 392                                 nw = cnt;
 393                         } else {
 394                                 if (pending != 0) {
 395                                         if (force)
 396                                                 pending--;
 397                                         if (lseek(out.fd, pending, SEEK_CUR) ==
 398                                             -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 ((size_t)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 ((size_t)nw == cnt)
 429                                 break;
 430                         if (out.flags & ISTAPE)
 431                                 errx(1, "%s: short write on tape device",
 432                                     out.name);
 433                         if (out.flags & ISCHR && !warned) {
 434                                 warned = 1;
 435                                 warnx("%s: short write on character device",
 436                                     out.name);
 437                         }
 438                 }
 439                 if ((out.dbcnt -= n) < out.dbsz)
 440                         break;
 441         }
 442
 443         /* Reassemble the output block. */
 444         if (out.dbcnt)
 445                 memmove(out.db, out.dbp - out.dbcnt, out.dbcnt);
 446         out.dbp = out.db + out.dbcnt;
 447 }