/* 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;

}