1 /* Copyright (C) 2012 Red Hat, Inc.
2 This file is part of elfutils.
3
4 This file is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 3 of the License, or
7 (at your option) any later version.
8
9 elfutils is distributed in the hope that it will be useful, but
10 WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
16
17 #ifdef HAVE_CONFIG_H
18 # include <config.h>
19 #endif
20
21 #include <sys/types.h>
22 #include <sys/stat.h>
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <unistd.h>
26 #include <errno.h>
27 #include <string.h>
28 #include <fcntl.h>
29 #include <gelf.h>
30 #include <libelf.h>
31 #include <stdbool.h>
32 #include <inttypes.h>
33
34 int
main(int argc,char * argv[])35 main (int argc, char *argv[])
36 {
37 if (argc != 3)
38 {
39 fprintf (stderr, "Needs two arguments.\n");
40 fprintf (stderr, "First needs to be 'READ', 'MMAP' or 'FDREAD'\n");
41 fprintf (stderr, "Second is the ELF file to read.\n");
42 exit (2); /* user error */
43 }
44
45 bool do_mmap = false;
46 bool close_fd = false;
47 if (strcmp (argv[1], "READ") == 0)
48 {
49 do_mmap = false;
50 close_fd = false;
51 }
52 else if (strcmp (argv[1], "MMAP") == 0)
53 {
54 do_mmap = true;
55 close_fd = false;
56 }
57 else if (strcmp (argv[1], "FDREAD") == 0)
58 {
59 do_mmap = false;
60 close_fd = true;
61 }
62 else
63 {
64 fprintf (stderr, "First arg needs to be 'READ', 'MMAP' or 'FDREAD'\n");
65 exit (2); /* user error */
66 }
67
68 elf_version (EV_CURRENT);
69
70 int fd = open (argv[2], O_RDONLY);
71 if (fd < 0)
72 {
73 fprintf (stderr, "Cannot open input file %s: %s\n", argv[2],
74 strerror (errno));
75 exit (2);
76 }
77
78 Elf *elf = elf_begin (fd, do_mmap ? ELF_C_READ_MMAP : ELF_C_READ, NULL);
79 if (elf == NULL)
80 {
81 fprintf (stderr, "elf_begin failed for %s: %s\n", argv[2],
82 elf_errmsg (-1));
83 exit (2);
84 }
85
86 if (! do_mmap && close_fd)
87 {
88 if (elf_cntl (elf, ELF_C_FDREAD) < 0)
89 {
90 fprintf (stderr, "elf_cntl failed for %s: %s\n", argv[2],
91 elf_errmsg (-1));
92 exit (1);
93 }
94 close (fd);
95 }
96
97 Elf_Scn *scn = NULL;
98 while ((scn = elf_nextscn (elf, scn)) != NULL)
99 {
100 GElf_Shdr shdr_mem;
101 GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
102 printf ("Section at offset %#0" PRIx64 "\n", shdr->sh_offset);
103 }
104
105 elf_end (elf);
106 exit (0);
107 }
108