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/* Test program for extracting ELF Note headers and getting whole notes.
Copyright (C) 2019 Red Hat, Inc.
This file is part of elfutils.
This file 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 3 of the License, or
(at your option) any later version.
elfutils 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, see <http://www.gnu.org/licenses/>. */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include ELFUTILS_HEADER(elf)
#include <gelf.h>
int
main (int argc, char *argv[])
{
if (argc != 2)
{
printf ("No ELF file given as argument\n");
exit (1);
}
const char *fname = argv[1];
// Initialize libelf.
elf_version (EV_CURRENT);
/* Read the ELF from disk now. */
int fd = open (fname, O_RDONLY);
if (fd == -1)
{
printf ("cannot open '%s': %s\n", fname, strerror (errno));
exit (1);
}
Elf *elf = elf_begin (fd, ELF_C_READ, NULL);
if (elf == NULL)
{
printf ("cannot create ELF descriptor: %s\n", elf_errmsg (-1));
exit (1);
}
GElf_Ehdr ehdr;
if (gelf_getehdr (elf, &ehdr) == NULL)
{
printf ("cannot get Ehdr: %s\n", elf_errmsg (-1));
exit (1);
}
/* Search for all SHT_NOTE sections. */
Elf_Scn *scn = NULL;
while ((scn = elf_nextscn (elf, scn)) != NULL)
{
/* Get the header. */
GElf_Shdr shdr;
if (gelf_getshdr (scn, &shdr) == NULL)
{
printf ("couldn't get shdr: %s\n", elf_errmsg (-1));
exit (1);
}
if (shdr.sh_type == SHT_NOTE)
{
printf ("Notes in section %zd:\n", elf_ndxscn (scn));
Elf_Data *raw = elf_rawdata (scn, NULL);
if (raw == NULL)
{
printf ("couldn't get raw data: %s\n", elf_errmsg (-1));
exit (1);
}
Elf_Data *data = elf_getdata (scn, NULL);
if (data == NULL)
{
printf ("couldn't get data: %s\n", elf_errmsg (-1));
exit (1);
}
size_t off = 0;
size_t next;
GElf_Nhdr nhdr;
size_t n_off;
size_t d_off;
while ((next = gelf_getnote (data, off, &nhdr, &n_off, &d_off)) > 0)
{
/* Now just get the note header "raw" (don't
copy/translate the note data). This only handles
traditional GNU ELF Notes, so we still use the next
from gelf_getnote (padding is different for new style
ELF_T_NHDR8 notes). */
Elf32_Nhdr nh;
Elf_Data src =
{
.d_version = EV_CURRENT, .d_type = ELF_T_NHDR,
.d_size = sizeof nh
};
Elf_Data dst = src;
src.d_buf = raw->d_buf + off;
dst.d_buf = &nh;
if (elf32_xlatetom (&dst, &src, ehdr.e_ident[EI_DATA]) == NULL)
{
printf ("couldn't xlate note: %s\n", elf_errmsg (-1));
exit (1);
}
printf ("type: %" PRId32 ",%" PRId32
", namesz: %" PRId32 ",%" PRId32
", descsz: %" PRId32 ",%" PRId32 "\n",
nhdr.n_type, nh.n_type,
nhdr.n_namesz, nh.n_namesz,
nhdr.n_descsz, nh.n_descsz);
if (nhdr.n_type != nh.n_type
|| nhdr.n_namesz != nh.n_namesz
|| nhdr.n_descsz != nh.n_descsz)
{
printf ("Nhdrs not equal!\n");
exit (1);
}
off = next;
}
}
}
if (elf_end (elf) != 0)
{
printf ("failure in elf_end: %s\n", elf_errmsg (-1));
exit (1);
}
close (fd);
return 0;
}
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