/* Copyright (C) 1999-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Andreas Jaeger <aj@suse.de>, 1999 and

		  Jakub Jelinek <jakub@redhat.com>, 1999.

   This program 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; version 2 of the License, or

   (at your option) any later version.

   This program 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/>.  */

/* The code in this file and in readelflib is a heavily simplified

   version of the readelf program that's part of the current binutils

   development version.  Besides the simplification, it has also been

   modified to read some other file formats.  */

#include <a.out.h>

#include <elf.h>

#include <error.h>

#include <libintl.h>

#include <link.h>

#include <stdio.h>

#include <string.h>

#include <unistd.h>

#include <sys/mman.h>

#include <sys/param.h>

#include <sys/stat.h>

#include <gnu/lib-names.h>

#include <ldconfig.h>

#define Elf32_CLASS ELFCLASS32

#define Elf64_CLASS ELFCLASS64

struct known_names

{

  const char *soname;

  int flag;

};

static struct known_names interpreters[] =

{

  { "/lib/" LD_SO, FLAG_ELF_LIBC6 },

#ifdef SYSDEP_KNOWN_INTERPRETER_NAMES

  SYSDEP_KNOWN_INTERPRETER_NAMES

#endif

};

static struct known_names known_libs[] =

{

  { LIBC_SO, FLAG_ELF_LIBC6 },

  { LIBM_SO, FLAG_ELF_LIBC6 },

#ifdef SYSDEP_KNOWN_LIBRARY_NAMES

  SYSDEP_KNOWN_LIBRARY_NAMES

#endif

};

/* Check if string corresponds to a GDB Python file.  */

static bool

is_gdb_python_file (const char *name)

{

  size_t len = strlen (name);

  return len > 7 && strcmp (name + len - 7, "-gdb.py") == 0;

}

/* Returns 0 if everything is ok, != 0 in case of error.  */

int

process_file (const char *real_file_name, const char *file_name,

	      const char *lib, int *flag, unsigned int *osversion,

	      char **soname, int is_link, struct stat64 *stat_buf)

{

  FILE *file;

  struct stat64 statbuf;

  void *file_contents;

  int ret;

  ElfW(Ehdr) *elf_header;

  struct exec *aout_header;

  ret = 0;

  *flag = FLAG_ANY;

  *soname = NULL;

  file = fopen (real_file_name, "rb");

  if (file == NULL)

    {

      /* No error for stale symlink.  */

      if (is_link && strstr (file_name, ".so") != NULL)

	return 1;

      error (0, 0, _("Input file %s not found.\n"), file_name);

      return 1;

    }

  if (fstat64 (fileno (file), &statbuf) < 0)

    {

      error (0, 0, _("Cannot fstat file %s.\n"), file_name);

      fclose (file);

      return 1;

    }

  /* Check that the file is large enough so that we can access the

     information.  We're only checking the size of the headers here.  */

  if ((size_t) statbuf.st_size < sizeof (struct exec)

      || (size_t) statbuf.st_size < sizeof (ElfW(Ehdr)))

    {

      if (statbuf.st_size == 0)

	error (0, 0, _("File %s is empty, not checked."), file_name);

      else

	{

	  char buf[SELFMAG];

	  size_t n = MIN (statbuf.st_size, SELFMAG);

	  if (fread (buf, n, 1, file) == 1 && memcmp (buf, ELFMAG, n) == 0)

	    error (0, 0, _("File %s is too small, not checked."), file_name);

	}

      fclose (file);

      return 1;

    }

  file_contents = mmap (0, statbuf.st_size, PROT_READ, MAP_SHARED,

			fileno (file), 0);

  if (file_contents == MAP_FAILED)

    {

      error (0, 0, _("Cannot mmap file %s.\n"), file_name);

      fclose (file);

      return 1;

    }

  /* First check if this is an aout file.  */

  aout_header = (struct exec *) file_contents;

  if (N_MAGIC (*aout_header) == ZMAGIC

#ifdef QMAGIC			/* Linuxism.  */

      || N_MAGIC (*aout_header) == QMAGIC

#endif

      )

    {

      /* Aout files don't have a soname, just return the name

	 including the major number.  */

      char *copy, *major, *dot;

      copy = xstrdup (lib);

      major = strstr (copy, ".so.");

      if (major)

	{

	  dot = strstr (major + 4, ".");

	  if (dot)

	    *dot = '\0';

	}

      *soname = copy;

      *flag = FLAG_LIBC4;

      goto done;

    }

  elf_header = (ElfW(Ehdr) *) file_contents;

  if (memcmp (elf_header->e_ident, ELFMAG, SELFMAG) != 0)

    {

      /* The file is neither ELF nor aout.  Check if it's a linker

	 script, like libc.so - otherwise complain.  Only search the

	 beginning of the file.  */

      size_t len = MIN (statbuf.st_size, 512);

      if (memmem (file_contents, len, "GROUP", 5) == NULL

	  && memmem (file_contents, len, "GNU ld script", 13) == NULL

	  && !is_gdb_python_file (file_name))

	error (0, 0, _("%s is not an ELF file - it has the wrong magic bytes at the start.\n"),

	       file_name);

      ret = 1;

    }

  /* Libraries have to be shared object files.  */

  else if (elf_header->e_type != ET_DYN)

    ret = 1;

  else if (process_elf_file (file_name, lib, flag, osversion, soname,

			     file_contents, statbuf.st_size))

    ret = 1;

 done:

  /* Clean up allocated memory and resources.  */

  munmap (file_contents, statbuf.st_size);

  fclose (file);

  *stat_buf = statbuf;

  return ret;

}

/* Returns made up soname if lib doesn't have explicit DT_SONAME.  */

char *

implicit_soname (const char *lib, int flag)

{

  char *soname = xstrdup (lib);

  if ((flag & FLAG_TYPE_MASK) != FLAG_LIBC4)

    return soname;

  /* Aout files don't have a soname, just return the name

     including the major number.  */

  char *major = strstr (soname, ".so.");

  if (major)

    {

      char *dot = strstr (major + 4, ".");

      if (dot)

	*dot = '\0';

    }

  return soname;

}

/* Get architecture specific version of process_elf_file.  */

#include <readelflib.c>