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 #include <sys/types.h>
18 #include <sys/stat.h>
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <unistd.h>
22 #include <errno.h>
23 #include <string.h>
24 #include <fcntl.h>
25 #include <gelf.h>
26 #include <libelf.h>
27 #include <stdbool.h>
28 #include <inttypes.h>
29
30 int
main(int argc,char * argv[])31 main (int argc, char *argv[])
32 {
33 if (argc != 3)
34 {
35 fprintf (stderr, "Needs two arguments.\n");
36 fprintf (stderr, "First needs to be 'READ', 'MMAP' or 'FDREAD'\n");
37 fprintf (stderr, "Second is the ELF file to read.\n");
38 exit (2); /* user error */
39 }
40
41 bool do_mmap = false;
42 bool close_fd = false;
43 if (strcmp (argv[1], "READ") == 0)
44 {
45 do_mmap = false;
46 close_fd = false;
47 }
48 else if (strcmp (argv[1], "MMAP") == 0)
49 {
50 do_mmap = true;
51 close_fd = false;
52 }
53 else if (strcmp (argv[1], "FDREAD") == 0)
54 {
55 do_mmap = false;
56 close_fd = true;
57 }
58 else
59 {
60 fprintf (stderr, "First arg needs to be 'READ', 'MMAP' or 'FDREAD'\n");
61 exit (2); /* user error */
62 }
63
64 elf_version (EV_CURRENT);
65
66 int fd = open (argv[2], O_RDONLY);
67 if (fd < 0)
68 {
69 fprintf (stderr, "Cannot open input file %s: %s\n", argv[2],
70 strerror (errno));
71 exit (2);
72 }
73
74 Elf *elf = elf_begin (fd, do_mmap ? ELF_C_READ_MMAP : ELF_C_READ, NULL);
75 if (elf == NULL)
76 {
77 fprintf (stderr, "elf_begin failed for %s: %s\n", argv[2],
78 elf_errmsg (-1));
79 exit (2);
80 }
81
82 if (! do_mmap && close_fd)
83 {
84 if (elf_cntl (elf, ELF_C_FDREAD) < 0)
85 {
86 fprintf (stderr, "elf_cntl failed for %s: %s\n", argv[2],
87 elf_errmsg (-1));
88 exit (1);
89 }
90 close (fd);
91 }
92
93 Elf_Scn *scn = NULL;
94 while ((scn = elf_nextscn (elf, scn)) != NULL)
95 {
96 GElf_Shdr shdr_mem;
97 GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
98 printf ("Section at offset %#0" PRIx64 "\n", shdr->sh_offset);
99 }
100
101 elf_end (elf);
102 exit (0);
103 }
104