/*************************************************************************** * binoffset.c * (C) 2002 Randy Dunlap <rddunlap@osdl.org> # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 2 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program; if not, write to the Free Software # Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. # binoffset.c: # - searches a (binary) file for a specified (binary) pattern # - returns the offset of the located pattern or ~0 if not found # - exits with exit status 0 normally or non-0 if pattern is not found # or any other error occurs. ****************************************************************/ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <errno.h> #include <unistd.h> #include <fcntl.h> #include <sys/types.h> #include <sys/stat.h> #include <sys/mman.h> #define VERSION "0.1" #define BUF_SIZE (16 * 1024) #define PAT_SIZE 100 char *progname; char *inputname; int inputfd; unsigned int bix; /* buf index */ unsigned char patterns [PAT_SIZE] = {0}; /* byte-sized pattern array */ int pat_len; /* actual number of pattern bytes */ unsigned char *madr; /* mmap address */ size_t filesize; int num_matches = 0; off_t firstloc = 0; void usage (void) { fprintf (stderr, "%s ver. %s\n", progname, VERSION); fprintf (stderr, "usage: %s filename pattern_bytes\n", progname); fprintf (stderr, " [prints location of pattern_bytes in file]\n"); exit (1); } void get_pattern (int pat_count, char *pats []) { int ix, err, tmp; #ifdef DEBUG fprintf (stderr,"get_pattern: count = %d\n", pat_count); for (ix = 0; ix < pat_count; ix++) fprintf (stderr, " pat # %d: [%s]\n", ix, pats[ix]); #endif for (ix = 0; ix < pat_count; ix++) { tmp = 0; err = sscanf (pats[ix], "%5i", &tmp); if (err != 1 || tmp > 0xff) { fprintf (stderr, "pattern or value error in pattern # %d [%s]\n", ix, pats[ix]); usage (); } patterns [ix] = tmp; } pat_len = pat_count; } void search_pattern (void) { for (bix = 0; bix < filesize; bix++) { if (madr[bix] == patterns[0]) { if (memcmp (&madr[bix], patterns, pat_len) == 0) { if (num_matches == 0) firstloc = bix; num_matches++; } } } } #ifdef NOTDEF size_t get_filesize (int fd) { off_t end_off = lseek (fd, 0, SEEK_END); lseek (fd, 0, SEEK_SET); return (size_t) end_off; } #endif size_t get_filesize (int fd) { int err; struct stat stat; err = fstat (fd, &stat); fprintf (stderr, "filesize: %ld\n", err < 0 ? (long)err : stat.st_size); if (err < 0) return err; return (size_t) stat.st_size; } int main (int argc, char *argv []) { progname = argv[0]; if (argc < 3) usage (); get_pattern (argc - 2, argv + 2); inputname = argv[1]; inputfd = open (inputname, O_RDONLY); if (inputfd == -1) { fprintf (stderr, "%s: cannot open '%s'\n", progname, inputname); exit (3); } filesize = get_filesize (inputfd); madr = mmap (0, filesize, PROT_READ, MAP_PRIVATE, inputfd, 0); if (madr == MAP_FAILED) { fprintf (stderr, "mmap error = %d\n", errno); close (inputfd); exit (4); } search_pattern (); if (munmap (madr, filesize)) fprintf (stderr, "munmap error = %d\n", errno); if (close (inputfd)) fprintf (stderr, "%s: error %d closing '%s'\n", progname, errno, inputname); fprintf (stderr, "number of pattern matches = %d\n", num_matches); if (num_matches == 0) firstloc = ~0; printf ("%ld\n", firstloc); fprintf (stderr, "%ld\n", firstloc); exit (num_matches ? 0 : 2); } /* end binoffset.c */