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
41 char *progname;
42 char *inputname;
43 int inputfd;
44 unsigned int bix; /* buf index */
45 unsigned char patterns [PAT_SIZE] = {0}; /* byte-sized pattern array */
46 int pat_len; /* actual number of pattern bytes */
47 unsigned char *madr; /* mmap address */
48 size_t filesize;
49 int num_matches = 0;
50 off_t firstloc = 0;
51
usage(void)52 void 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
get_pattern(int pat_count,char * pats[])61 void 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
search_pattern(void)84 void 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
get_filesize(int fd)98 size_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
get_filesize(int fd)106 size_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
main(int argc,char * argv[])118 int 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