LXR linux/scripts/binoffset.c

   1/***************************************************************************
   2 * binoffset.c
   3 * (C) 2002 Randy Dunlap <rdunlap@xenotime.net>
   4
   5#   This program is free software; you can redistribute it and/or modify
   6#   it under the terms of the GNU General Public License as published by
   7#   the Free Software Foundation; either version 2 of the License, or
   8#   (at your option) any later version.
   9#
  10#   This program is distributed in the hope that it will be useful,
  11#   but WITHOUT ANY WARRANTY; without even the implied warranty of
  12#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13#   GNU General Public License for more details.
  14#
  15#   You should have received a copy of the GNU General Public License
  16#   along with this program; if not, write to the Free Software
  17#   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18
  19# binoffset.c:
  20# - searches a (binary) file for a specified (binary) pattern
  21# - returns the offset of the located pattern or ~0 if not found
  22# - exits with exit status 0 normally or non-0 if pattern is not found
  23#   or any other error occurs.
  24
  25****************************************************************/
  26
  27#include <stdio.h>
  28#include <stdlib.h>
  29#include <string.h>
  30#include <errno.h>
  31#include <unistd.h>
  32#include <fcntl.h>
  33#include <sys/types.h>
  34#include <sys/stat.h>
  35#include <sys/mman.h>
  36
  37#define VERSION         "0.1"
  38#define BUF_SIZE        (16 * 1024)
  39#define PAT_SIZE        100
  40
  41char            *progname;
  42char            *inputname;
  43int             inputfd;
  44unsigned int    bix;                    /* buf index */
  45unsigned char   patterns [PAT_SIZE] = {0}; /* byte-sized pattern array */
  46int             pat_len;                /* actual number of pattern bytes */
  47unsigned char   *madr;                  /* mmap address */
  48size_t          filesize;
  49int             num_matches = 0;
  50off_t           firstloc = 0;
  51
  52void usage (void)
  53{
  54        fprintf (stderr, "%s ver. %s\n", progname, VERSION);
  55        fprintf (stderr, "usage:  %s filename pattern_bytes\n",
  56                        progname);
  57        fprintf (stderr, "        [prints location of pattern_bytes in file]\n");
  58        exit (1);
  59}
  60
  61void get_pattern (int pat_count, char *pats [])
  62{
  63        int ix, err, tmp;
  64
  65#ifdef DEBUG
  66        fprintf (stderr,"get_pattern: count = %d\n", pat_count);
  67        for (ix = 0; ix < pat_count; ix++)
  68                fprintf (stderr, "  pat # %d:  [%s]\n", ix, pats[ix]);
  69#endif
  70
  71        for (ix = 0; ix < pat_count; ix++) {
  72                tmp = 0;
  73                err = sscanf (pats[ix], "%5i", &tmp);
  74                if (err != 1 || tmp > 0xff) {
  75                        fprintf (stderr, "pattern or value error in pattern # %d [%s]\n",
  76                                        ix, pats[ix]);
  77                        usage ();
  78                }
  79                patterns [ix] = tmp;
  80        }
  81        pat_len = pat_count;
  82}
  83
  84void search_pattern (void)
  85{
  86        for (bix = 0; bix < filesize; bix++) {
  87                if (madr[bix] == patterns[0]) {
  88                        if (memcmp (&madr[bix], patterns, pat_len) == 0) {
  89                                if (num_matches == 0)
  90                                        firstloc = bix;
  91                                num_matches++;
  92                        }
  93                }
  94        }
  95}
  96
  97#ifdef NOTDEF
  98size_t get_filesize (int fd)
  99{
 100        off_t end_off = lseek (fd, 0, SEEK_END);
 101        lseek (fd, 0, SEEK_SET);
 102        return (size_t) end_off;
 103}
 104#endif
 105
 106size_t get_filesize (int fd)
 107{
 108        int err;
 109        struct stat stat;
 110
 111        err = fstat (fd, &stat);
 112        fprintf (stderr, "filesize: %ld\n", err < 0 ? (long)err : stat.st_size);
 113        if (err < 0)
 114                return err;
 115        return (size_t) stat.st_size;
 116}
 117
 118int main (int argc, char *argv [])
 119{
 120        progname = argv[0];
 121
 122        if (argc < 3)
 123                usage ();
 124
 125        get_pattern (argc - 2, argv + 2);
 126
 127        inputname = argv[1];
 128
 129        inputfd = open (inputname, O_RDONLY);
 130        if (inputfd == -1) {
 131                fprintf (stderr, "%s: cannot open '%s'\n",
 132                                progname, inputname);
 133                exit (3);
 134        }
 135
 136        filesize = get_filesize (inputfd);
 137
 138        madr = mmap (0, filesize, PROT_READ, MAP_PRIVATE, inputfd, 0);
 139        if (madr == MAP_FAILED) {
 140                fprintf (stderr, "mmap error = %d\n", errno);
 141                close (inputfd);
 142                exit (4);
 143        }
 144
 145        search_pattern ();
 146
 147        if (munmap (madr, filesize))
 148                fprintf (stderr, "munmap error = %d\n", errno);
 149
 150        if (close (inputfd))
 151                fprintf (stderr, "%s: error %d closing '%s'\n",
 152                                progname, errno, inputname);
 153
 154        fprintf (stderr, "number of pattern matches = %d\n", num_matches);
 155        if (num_matches == 0)
 156                firstloc = ~0;
 157        printf ("%ld\n", firstloc);
 158        fprintf (stderr, "%ld\n", firstloc);
 159
 160        exit (num_matches ? 0 : 2);
 161}
 162
 163/* end binoffset.c */
 164