dd/dd.c

   1 /*      $NetBSD: dd.c,v 1.12 1998/08/19 01:32:44 thorpej Exp $  */
   2
   3 /*-
   4  * Copyright (c) 1991, 1993, 1994
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Keith Muller of the University of California, San Diego and Lance
   9  * Visser of Convex Computer Corporation.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. All advertising materials mentioning features or use of this software
  20  *    must display the following acknowledgement:
  21  *      This product includes software developed by the University of
  22  *      California, Berkeley and its contributors.
  23  * 4. Neither the name of the University nor the names of its contributors
  24  *    may be used to endorse or promote products derived from this software
  25  *    without specific prior written permission.
  26  *
  27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  37  * SUCH DAMAGE.
  38  */
  39
  40 #include <sys/cdefs.h>
  41 #ifndef lint
  42 __COPYRIGHT("@(#) 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
  47 #if 0
  48 static char sccsid[] = "@(#)dd.c        8.5 (Berkeley) 4/2/94";
  49 #else
  50 __RCSID("$NetBSD: dd.c,v 1.12 1998/08/19 01:32:44 thorpej Exp $");
  51 #endif
  52 #endif /* not lint */
  53
  54 #include <sys/param.h>
  55 #include <sys/stat.h>
  56 #include <sys/ioctl.h>
  57 #include <sys/mtio.h>
  58
  59 #include <ctype.h>
  60 #include <err.h>
  61 #include <errno.h>
  62 #include <fcntl.h>
  63 #include <signal.h>
  64 #include <stdio.h>
  65 #include <stdlib.h>
  66 #include <string.h>
  67 #include <time.h>
  68 #include <unistd.h>
  69
  70 #include "dd.h"
  71 #include "extern.h"
  72
  73 static void dd_close __P((void));
  74 static void dd_in __P((void));
  75 static void getfdtype __P((IO *));
  76 static void setup __P((void));
  77
  78 int main __P((int, char *[]));
  79
  80 IO      in, out;                /* input/output state */
  81 STAT    st;                     /* statistics */
  82 void    (*cfunc) __P((void));   /* conversion function */
  83 u_long  cpy_cnt;                /* # of blocks to copy */
  84 u_int   ddflags;                /* conversion options */
  85 u_int   cbsz;                   /* conversion block size */
  86 u_int   files_cnt = 1;          /* # of files to copy */
  87 const u_char    *ctab;          /* conversion table */
  88
  89 int
  90 main(argc, argv)
  91         int argc;
  92         char *argv[];
  93 {
  94         jcl(argv);
  95         setup();
  96
  97         (void)signal(SIGINFO, summaryx);
  98         (void)signal(SIGINT, terminate);
  99
 100         (void)atexit(summary);
 101
 102         while (files_cnt--)
 103                 dd_in();
 104
 105         dd_close();
 106         exit(0);
 107         /* NOTREACHED */
 108 }
 109
 110 static void
 111 setup()
 112 {
 113         u_int cnt;
 114
 115         if (in.name == NULL) {
 116                 in.name = "stdin";
 117                 in.fd = STDIN_FILENO;
 118         } else {
 119                 in.fd = open(in.name, O_RDONLY, 0);
 120                 if (in.fd < 0)
 121                         err(1, "%s", in.name);
 122         }
 123
 124         getfdtype(&in);
 125
 126         if (files_cnt > 1 && !(in.flags & ISTAPE))
 127                 errx(1, "files is not supported for non-tape devices");
 128
 129         if (out.name == NULL) {
 130                 /* No way to check for read access here. */
 131                 out.fd = STDOUT_FILENO;
 132                 out.name = "stdout";
 133         } else {
 134 #define OFLAGS \
 135     (O_CREAT | (ddflags & (C_SEEK | C_NOTRUNC) ? 0 : O_TRUNC))
 136                 out.fd = open(out.name, O_RDWR | OFLAGS, DEFFILEMODE);
 137                 /*
 138                  * May not have read access, so try again with write only.
 139                  * Without read we may have a problem if output also does
 140                  * not support seeks.
 141                  */
 142                 if (out.fd < 0) {
 143                         out.fd = open(out.name, O_WRONLY | OFLAGS, DEFFILEMODE);
 144                         out.flags |= NOREAD;
 145                 }
 146                 if (out.fd < 0)
 147                         err(1, "%s", out.name);
 148         }
 149
 150         getfdtype(&out);
 151
 152         /*
 153          * Allocate space for the input and output buffers.  If not doing
 154          * record oriented I/O, only need a single buffer.
 155          */
 156         if (!(ddflags & (C_BLOCK|C_UNBLOCK))) {
 157                 if ((in.db = malloc(out.dbsz + in.dbsz - 1)) == NULL)
 158                         err(1, "%s", "");
 159                 out.db = in.db;
 160         } else if ((in.db =
 161             malloc((u_int)(MAX(in.dbsz, cbsz) + cbsz))) == NULL ||
 162             (out.db = malloc((u_int)(out.dbsz + cbsz))) == NULL)
 163                 err(1, "%s", "");
 164         in.dbp = in.db;
 165         out.dbp = out.db;
 166
 167         /* Position the input/output streams. */
 168         if (in.offset)
 169                 pos_in();
 170         if (out.offset)
 171                 pos_out();
 172
 173         /*
 174          * Truncate the output file; ignore errors because it fails on some
 175          * kinds of output files, tapes, for example.
 176          */
 177         if ((ddflags & (C_OF | C_SEEK | C_NOTRUNC)) == (C_OF | C_SEEK))
 178                 (void)ftruncate(out.fd, (off_t)out.offset * out.dbsz);
 179
 180         /*
 181          * If converting case at the same time as another conversion, build a
 182          * table that does both at once.  If just converting case, use the
 183          * built-in tables.
 184          */
 185         if (ddflags & (C_LCASE|C_UCASE)) {
 186 #ifdef  NO_CONV
 187                 /* Should not get here, but just in case... */
 188                 errx(1, "case conv and -DNO_CONV");
 189 #else   /* NO_CONV */
 190                 if (ddflags & C_ASCII || ddflags & 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(cnt);
 202                         } else {
 203                                 for (cnt = 0; cnt < 0377; ++cnt)
 204                                         casetab[cnt] = toupper(cnt);
 205                         }
 206                 }
 207
 208                 ctab = casetab;
 209 #endif  /* NO_CONV */
 210         }
 211
 212         (void)time(&st.start);                  /* Statistics timestamp. */
 213 }
 214
 215 static void
 216 getfdtype(io)
 217         IO *io;
 218 {
 219         struct mtget mt;
 220         struct stat sb;
 221
 222         if (fstat(io->fd, &sb))
 223                 err(1, "%s", io->name);
 224         if (S_ISCHR(sb.st_mode))
 225                 io->flags |= ioctl(io->fd, MTIOCGET, &mt) ? ISCHR : ISTAPE;
 226         else if (lseek(io->fd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE)
 227                 io->flags |= ISPIPE;            /* XXX fixed in 4.4BSD */
 228 }
 229
 230 static void
 231 dd_in()
 232 {
 233         int flags, n;
 234
 235         for (flags = ddflags;;) {
 236                 if (cpy_cnt && (st.in_full + st.in_part) >= cpy_cnt)
 237                         return;
 238
 239                 /*
 240                  * Clear the buffer first if doing "sync" on input.
 241                  * If doing block operations use spaces.  This will
 242                  * affect not only the C_NOERROR case, but also the
 243                  * last partial input block which should be padded
 244                  * with zero and not garbage.
 245                  */
 246                 if (flags & C_SYNC) {
 247                         if (flags & (C_BLOCK|C_UNBLOCK))
 248                                 (void)memset(in.dbp, ' ', in.dbsz);
 249                         else
 250                                 (void)memset(in.dbp, 0, in.dbsz);
 251                 }
 252
 253                 n = read(in.fd, in.dbp, in.dbsz);
 254                 if (n == 0) {
 255                         in.dbrcnt = 0;
 256                         return;
 257                 }
 258
 259                 /* Read error. */
 260                 if (n < 0) {
 261                         /*
 262                          * If noerror not specified, die.  POSIX requires that
 263                          * the warning message be followed by an I/O display.
 264                          */
 265                         if (!(flags & C_NOERROR))
 266                                 err(1, "%s", in.name);
 267                         warn("%s", in.name);
 268                         summary();
 269
 270                         /*
 271                          * If it's not a tape drive or a pipe, seek past the
 272                          * error.  If your OS doesn't do the right thing for
 273                          * raw disks this section should be modified to re-read
 274                          * in sector size chunks.
 275                          */
 276                         if (!(in.flags & (ISPIPE|ISTAPE)) &&
 277                             lseek(in.fd, (off_t)in.dbsz, SEEK_CUR))
 278                                 warn("%s", in.name);
 279
 280                         /* If sync not specified, omit block and continue. */
 281                         if (!(ddflags & C_SYNC))
 282                                 continue;
 283
 284                         /* Read errors count as full blocks. */
 285                         in.dbcnt += in.dbrcnt = in.dbsz;
 286                         ++st.in_full;
 287
 288                 /* Handle full input blocks. */
 289                 } else if (n == in.dbsz) {
 290                         in.dbcnt += in.dbrcnt = n;
 291                         ++st.in_full;
 292
 293                 /* Handle partial input blocks. */
 294                 } else {
 295                         /* If sync, use the entire block. */
 296                         if (ddflags & C_SYNC)
 297                                 in.dbcnt += in.dbrcnt = in.dbsz;
 298                         else
 299                                 in.dbcnt += in.dbrcnt = n;
 300                         ++st.in_part;
 301                 }
 302
 303                 /*
 304                  * POSIX states that if bs is set and no other conversions
 305                  * than noerror, notrunc or sync are specified, the block
 306                  * is output without buffering as it is read.
 307                  */
 308                 if (ddflags & C_BS) {
 309                         out.dbcnt = in.dbcnt;
 310                         dd_out(1);
 311                         in.dbcnt = 0;
 312                         continue;
 313                 }
 314
 315                 if (ddflags & C_SWAB) {
 316                         if ((n = in.dbcnt) & 1) {
 317                                 ++st.swab;
 318                                 --n;
 319                         }
 320                         swab(in.dbp, in.dbp, n);
 321                 }
 322
 323                 in.dbp += in.dbrcnt;
 324                 (*cfunc)();
 325         }
 326 }
 327
 328 /*
 329  * Cleanup any remaining I/O and flush output.  If necesssary, output file
 330  * is truncated.
 331  */
 332 static void
 333 dd_close()
 334 {
 335         if (cfunc == def)
 336                 def_close();
 337         else if (cfunc == block)
 338                 block_close();
 339         else if (cfunc == unblock)
 340                 unblock_close();
 341         if (ddflags & C_OSYNC && out.dbcnt < out.dbsz) {
 342                 (void)memset(out.dbp, 0, out.dbsz - out.dbcnt);
 343                 out.dbcnt = out.dbsz;
 344         }
 345         if (out.dbcnt)
 346                 dd_out(1);
 347 }
 348
 349 void
 350 dd_out(force)
 351         int force;
 352 {
 353         static int warned;
 354         int cnt, n, nw;
 355         u_char *outp;
 356
 357         /*
 358          * Write one or more blocks out.  The common case is writing a full
 359          * output block in a single write; increment the full block stats.
 360          * Otherwise, we're into partial block writes.  If a partial write,
 361          * and it's a character device, just warn.  If a tape device, quit.
 362          *
 363          * The partial writes represent two cases.  1: Where the input block
 364          * was less than expected so the output block was less than expected.
 365          * 2: Where the input block was the right size but we were forced to
 366          * write the block in multiple chunks.  The original versions of dd(1)
 367          * never wrote a block in more than a single write, so the latter case
 368          * never happened.
 369          *
 370          * One special case is if we're forced to do the write -- in that case
 371          * we play games with the buffer size, and it's usually a partial write.
 372          */
 373         outp = out.db;
 374         for (n = force ? out.dbcnt : out.dbsz;; n = out.dbsz) {
 375                 for (cnt = n;; cnt -= nw) {
 376                         nw = write(out.fd, outp, cnt);
 377                         if (nw <= 0) {
 378                                 if (nw == 0)
 379                                         errx(1, "%s: end of device", out.name);
 380                                 if (errno != EINTR)
 381                                         err(1, "%s", out.name);
 382                                 nw = 0;
 383                         }
 384                         outp += nw;
 385                         st.bytes += nw;
 386                         if (nw == n) {
 387                                 if (n != out.dbsz)
 388                                         ++st.out_part;
 389                                 else
 390                                         ++st.out_full;
 391                                 break;
 392                         }
 393                         ++st.out_part;
 394                         if (nw == cnt)
 395                                 break;
 396                         if (out.flags & ISCHR && !warned) {
 397                                 warned = 1;
 398                                 warnx("%s: short write on character device",
 399                                     out.name);
 400                         }
 401                         if (out.flags & ISTAPE)
 402                                 errx(1, "%s: short write on tape device", out.name);
 403                 }
 404                 if ((out.dbcnt -= n) < out.dbsz)
 405                         break;
 406         }
 407
 408         /* Reassemble the output block. */
 409         if (out.dbcnt)
 410                 (void)memmove(out.db, out.dbp - out.dbcnt, out.dbcnt);
 411         out.dbp = out.db + out.dbcnt;
 412 }