1 /* Test program for elf_strptr function.
2 Copyright (C) 2015 Red Hat, Inc.
3 This file is part of elfutils.
4
5 This file 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 3 of the License, or
8 (at your option) any later version.
9
10 elfutils is distributed in the hope that it will be useful, but
11 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, see <http://www.gnu.org/licenses/>. */
17
18 #ifdef HAVE_CONFIG_H
19 # include <config.h>
20 #endif
21
22 #include <errno.h>
23 #include <fcntl.h>
24 #include <inttypes.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <string.h>
28 #include <unistd.h>
29
30 #include ELFUTILS_HEADER(elf)
31 #include <gelf.h>
32
33 static void
print_strings(Elf_Scn * scn,Elf * elf,size_t ndx)34 print_strings (Elf_Scn *scn, Elf *elf, size_t ndx)
35 {
36 GElf_Shdr shdr_mem;
37 GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
38
39 printf ("Strings in section %zd (%s):\n", ndx,
40 ((shdr->sh_flags & SHF_COMPRESSED) != 0
41 ? "compressed" : "uncompressed"));
42
43 size_t off = 0;
44 const char *str = elf_strptr (elf, ndx, off);
45 while (str != NULL)
46 {
47 printf ("[%zx] '%s'\n", off, str);
48 off += strlen (str) + 1;
49 str = elf_strptr (elf, ndx, off);
50 }
51 }
52
53 int
main(int argc,char * argv[])54 main (int argc, char *argv[])
55 {
56 if (argc != 2)
57 {
58 printf ("No ELF file given as argument");
59 exit (1);
60 }
61
62 const char *fname = argv[1];
63
64 // Initialize libelf.
65 elf_version (EV_CURRENT);
66
67 /* Read the ELF from disk now. */
68 int fd = open (fname, O_RDONLY);
69 if (fd == -1)
70 {
71 printf ("cannot open `%s' read-only: %s\n", fname, strerror (errno));
72 exit (1);
73 }
74
75 Elf *elf = elf_begin (fd, ELF_C_READ, NULL);
76 if (elf == NULL)
77 {
78 printf ("cannot create ELF descriptor read-only: %s\n", elf_errmsg (-1));
79 exit (1);
80 }
81
82 size_t ndx;
83 if (elf_getshdrstrndx (elf, &ndx) != 0)
84 {
85 printf ("cannot get section header table index: %s\n", elf_errmsg (-1));
86 exit (1);
87 }
88
89 if (ndx == SHN_UNDEF)
90 {
91 printf ("ELF file `%s' doesn't have a section header table index", fname);
92 exit (1);
93 }
94
95 Elf_Scn *scn = elf_getscn (elf, ndx);
96 if (scn == NULL)
97 {
98 printf ("Couldn't get section %zd: %s\n", ndx, elf_errmsg (-1));
99 exit (1);
100 }
101
102 if (elf_compress (scn, ELFCOMPRESS_ZLIB, 0) < 0)
103 {
104 printf ("Couldn't compress section %zd: %s\n", ndx, elf_errmsg (-1));
105 exit (1);
106 }
107 print_strings (scn, elf, ndx);
108
109 if (elf_compress (scn, 0, 0) < 0)
110 {
111 printf ("Couldn't decompress section %zd: %s\n", ndx, elf_errmsg (-1));
112 exit (1);
113 }
114 print_strings (scn, elf, ndx);
115
116 if (elf_end (elf) != 0)
117 {
118 printf ("failure in elf_end: %s\n", elf_errmsg (-1));
119 exit (1);
120 }
121
122 close (fd);
123
124 return 0;
125 }
126