/* Test program for elf_newdata function.
Copyright (C) 2015 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>
// Random data string (16 bytes).
static char *DATA = "123456789ABCDEF";
static size_t DATA_LEN = 16;
static void
add_section_data (Elf *elf, char *buf, size_t len)
{
printf ("Adding %zd bytes.\n", len);
Elf_Scn *scn = elf_getscn (elf, 1);
if (scn == NULL)
{
printf ("couldn't get data section: %s\n", elf_errmsg (-1));
exit (1);
}
Elf_Data *data = elf_newdata (scn);
if (data == NULL)
{
printf ("cannot create newdata for section: %s\n", elf_errmsg (-1));
exit (1);
}
data->d_buf = buf;
data->d_type = ELF_T_BYTE;
data->d_size = len;
data->d_align = 1;
data->d_version = EV_CURRENT;
// Let the library compute the internal structure information.
if (elf_update (elf, ELF_C_NULL) < 0)
{
printf ("failure in elf_update(NULL): %s\n", elf_errmsg (-1));
exit (1);
}
}
static Elf *
create_elf (int fd, int class, int use_mmap)
{
Elf *elf = elf_begin (fd, use_mmap ? ELF_C_WRITE_MMAP : ELF_C_WRITE, NULL);
if (elf == NULL)
{
printf ("cannot create ELF descriptor: %s\n", elf_errmsg (-1));
exit (1);
}
// Create an ELF header.
if (gelf_newehdr (elf, class) == 0)
{
printf ("cannot create ELF header: %s\n", elf_errmsg (-1));
exit (1);
}
GElf_Ehdr ehdr_mem;
GElf_Ehdr *ehdr = gelf_getehdr (elf, &ehdr_mem);
if (ehdr == NULL)
{
printf ("cannot get ELF header: %s\n", elf_errmsg (-1));
exit (1);
}
// Initialize header.
ehdr->e_ident[EI_DATA] = class == ELFCLASS32 ? ELFDATA2LSB : ELFDATA2MSB;
ehdr->e_ident[EI_OSABI] = ELFOSABI_GNU;
ehdr->e_type = ET_NONE;
ehdr->e_machine = class == ELFCLASS32 ? EM_PPC : EM_X86_64;
ehdr->e_version = EV_CURRENT;
// Update the ELF header.
if (gelf_update_ehdr (elf, ehdr) == 0)
{
printf ("cannot update ELF header: %s\n", elf_errmsg (-1));
exit (1);
}
// Create a section.
Elf_Scn *scn = elf_newscn (elf);
if (scn == NULL)
{
printf ("cannot create new section: %s\n", elf_errmsg (-1));
exit (1);
}
GElf_Shdr shdr_mem;
GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
if (shdr == NULL)
{
printf ("cannot get header for data section: %s\n", elf_errmsg (-1));
exit (1);
}
shdr->sh_type = SHT_PROGBITS;
shdr->sh_flags = 0;
shdr->sh_addr = 0;
shdr->sh_link = SHN_UNDEF;
shdr->sh_info = SHN_UNDEF;
shdr->sh_addralign = 1;
shdr->sh_entsize = 1;
shdr->sh_name = 0;
// Finish section, update the header.
if (gelf_update_shdr (scn, shdr) == 0)
{
printf ("cannot update header for DATA section: %s\n", elf_errmsg (-1));
exit (1);
}
// Add some data to the section.
add_section_data (elf, DATA, DATA_LEN);
// Write everything to disk.
if (elf_update (elf, ELF_C_WRITE) < 0)
{
printf ("failure in elf_update(WRITE): %s\n", elf_errmsg (-1));
exit (1);
}
return elf;
}
static Elf *
read_elf (int fd, int use_mmap)
{
printf ("Reading ELF file\n");
Elf *elf = elf_begin (fd, use_mmap ? ELF_C_RDWR_MMAP : ELF_C_RDWR, NULL);
if (elf == NULL)
{
printf ("cannot create ELF descriptor read-again: %s\n", elf_errmsg (-1));
exit (1);
}
return elf;
}
static void
check_section_size (Elf *elf, size_t size)
{
Elf_Scn *scn = elf_getscn (elf, 1);
if (scn == NULL)
{
printf ("couldn't get data section: %s\n", elf_errmsg (-1));
exit (1);
}
GElf_Shdr shdr_mem;
GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
if (shdr == NULL)
{
printf ("cannot get header for DATA section: %s\n", elf_errmsg (-1));
exit (1);
}
if (shdr->sh_size == size)
printf ("OK %zd bytes.\n", size);
else
{
printf ("BAD size, expected %zd, got %" PRIu64 "\n",
size, shdr->sh_size);
exit (-1);
}
}
static void
check_section_data (Elf *elf, char *data, size_t len, size_t times)
{
Elf_Scn *scn = elf_getscn (elf, 1);
if (scn == NULL)
{
printf ("couldn't get data section: %s\n", elf_errmsg (-1));
exit (1);
}
Elf_Data *d = NULL;
for (size_t i = 0; i < times; i++)
{
if (d == NULL || i * len >= d->d_off + d->d_size)
{
d = elf_getdata (scn, d);
if (d == NULL)
{
printf ("cannot get data for section item %zd: %s\n",
i, elf_errmsg (-1));
exit (1);
}
else
printf ("OK, section data item %zd (d_off: %" PRId64
", d_size: %zd)\n", i, d->d_off, d->d_size);
}
char *d_data = (char *) d->d_buf + (len * i) - d->d_off;
printf ("%zd data (d_off: %" PRId64
", len * i: %zd): (%p + %" PRId64 ") %s\n",
i, d->d_off, len * i, d->d_buf, (len * i) - d->d_off, d_data);
if (memcmp (data, d_data, len) != 0)
{
printf ("Got bad data in section for item %zd.\n", i);
exit (1);
}
}
}
static void
check_elf (int class, int use_mmap)
{
static const char *fname;
if (class == ELFCLASS32)
fname = use_mmap ? "newdata.elf32.mmap" : "newdata.elf32";
else
fname = use_mmap ? "newdata.elf64.mmap" : "newdata.elf64";
printf ("\ncheck_elf: %s\n", fname);
int fd = open (fname, O_RDWR|O_CREAT|O_TRUNC, 00666);
if (fd == -1)
{
printf ("cannot create `%s': %s\n", fname, strerror (errno));
exit (1);
}
Elf *elf = create_elf (fd, class, use_mmap);
check_section_size (elf, DATA_LEN);
check_section_data (elf, DATA, DATA_LEN, 1);
// Add some more data (won't be written to disk).
add_section_data (elf, DATA, DATA_LEN);
check_section_size (elf, 2 * DATA_LEN);
check_section_data (elf, DATA, DATA_LEN, 2);
if (elf_end (elf) != 0)
{
printf ("failure in elf_end: %s\n", elf_errmsg (-1));
exit (1);
}
close (fd);
// Read the ELF from disk now. And add new data directly.
fd = open (fname, O_RDONLY);
if (fd == -1)
{
printf ("cannot open `%s' read-only: %s\n", fname, strerror (errno));
exit (1);
}
elf = read_elf (fd, use_mmap);
check_section_size (elf, DATA_LEN);
// But don't check contents, that would read the data...
// Add some more data.
add_section_data (elf, DATA, DATA_LEN);
check_section_size (elf, 2 * DATA_LEN);
check_section_data (elf, DATA, DATA_LEN, 2);
// And some more.
add_section_data (elf, DATA, DATA_LEN);
check_section_size (elf, 3 * DATA_LEN);
check_section_data (elf, DATA, DATA_LEN, 3);
if (elf_end (elf) != 0)
{
printf ("failure in elf_end: %s\n", elf_errmsg (-1));
exit (1);
}
close (fd);
// Read the ELF from disk now. And add new data after raw reading.
fd = open (fname, O_RDONLY);
if (fd == -1)
{
printf ("cannot open `%s' read-only: %s\n", fname, strerror (errno));
exit (1);
}
elf = read_elf (fd, use_mmap);
check_section_size (elf, DATA_LEN);
// But don't check contents, that would read the data...
// Get raw data before adding new data.
Elf_Scn *scn = elf_getscn (elf, 1);
if (scn == NULL)
{
printf ("couldn't get data section: %s\n", elf_errmsg (-1));
exit (1);
}
printf ("elf_rawdata\n");
Elf_Data *data = elf_rawdata (scn, NULL);
if (data == NULL)
{
printf ("couldn't get raw data from section: %s\n", elf_errmsg (-1));
exit (1);
}
if (data->d_size != DATA_LEN)
{
printf ("Unexpected Elf_Data: %zd", data->d_size);
exit (1);
}
// Now add more data.
add_section_data (elf, DATA, DATA_LEN);
check_section_size (elf, 2 * DATA_LEN);
check_section_data (elf, DATA, DATA_LEN, 2);
// And some more.
add_section_data (elf, DATA, DATA_LEN);
check_section_size (elf, 3 * DATA_LEN);
check_section_data (elf, DATA, DATA_LEN, 3);
if (elf_end (elf) != 0)
{
printf ("failure in elf_end: %s\n", elf_errmsg (-1));
exit (1);
}
close (fd);
// Read the ELF from disk now. And add new data after data reading.
fd = open (fname, O_RDONLY);
if (fd == -1)
{
printf ("cannot open `%s' read-only: %s\n", fname, strerror (errno));
exit (1);
}
elf = read_elf (fd, use_mmap);
check_section_size (elf, DATA_LEN);
// Get (converted) data before adding new data.
check_section_data (elf, DATA, DATA_LEN, 1);
printf ("elf_getdata\n");
// Now add more data.
add_section_data (elf, DATA, DATA_LEN);
check_section_size (elf, 2 * DATA_LEN);
check_section_data (elf, DATA, DATA_LEN, 2);
// And some more.
add_section_data (elf, DATA, DATA_LEN);
check_section_size (elf, 3 * DATA_LEN);
check_section_data (elf, DATA, DATA_LEN, 3);
if (elf_end (elf) != 0)
{
printf ("failure in elf_end: %s\n", elf_errmsg (-1));
exit (1);
}
close (fd);
unlink (fname);
}
int
main (int argc __attribute__ ((unused)), char *argv[] __attribute__ ((unused)))
{
// Initialize libelf.
elf_version (EV_CURRENT);
// Fill holes with something non-zero to more easily spot bad data.
elf_fill ('X');
check_elf (ELFCLASS32, 0);
check_elf (ELFCLASS32, 1);
check_elf (ELFCLASS64, 0);
check_elf (ELFCLASS64, 1);
return 0;
}