/* Return number of program headers in the ELF file.

   Copyright (C) 2010, 2014, 2015, 2016 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 either

     * the GNU Lesser General Public License as published by the Free

       Software Foundation; either version 3 of the License, or (at

       your option) any later version

   or

     * the GNU General Public License as published by the Free

       Software Foundation; either version 2 of the License, or (at

       your option) any later version

   or both in parallel, as here.

   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 copies of the GNU General Public License and

   the GNU Lesser General Public License along with this program.  If

   not, see <http://www.gnu.org/licenses/>.  */

#ifdef HAVE_CONFIG_H

# include <config.h>

#endif

#include <assert.h>

#include <gelf.h>

#include <stddef.h>

#include "libelfP.h"

int

internal_function

__elf_getphdrnum_rdlock (Elf *elf, size_t *dst)

{

 if (unlikely (elf->state.elf64.ehdr == NULL))

   {

     /* Maybe no ELF header was created yet.  */

     __libelf_seterrno (ELF_E_WRONG_ORDER_EHDR);

     return -1;

   }

 *dst = (elf->class == ELFCLASS32

	 ? elf->state.elf32.ehdr->e_phnum

	 : elf->state.elf64.ehdr->e_phnum);

 if (*dst == PN_XNUM)

   {

     const Elf_ScnList *const scns = (elf->class == ELFCLASS32

				      ? &elf->state.elf32.scns

				      : &elf->state.elf64.scns);

     /* If there are no section headers, perhaps this is really just 65536

	written without PN_XNUM support.  Either that or it's bad data.  */

     if (elf->class == ELFCLASS32)

       {

	 if (likely (scns->cnt > 0))

	   {

	     Elf_Scn *scn = &elf->state.elf32.scns.data[0];

	     Elf32_Shdr *shdr = scn->shdr.e32 ?: __elf32_getshdr_rdlock (scn);

	     if (shdr)

	       *dst = shdr->sh_info;

	   }

       }

     else

       {

	 if (likely (scns->cnt > 0))

	   {

	     Elf_Scn *scn = &elf->state.elf64.scns.data[0];

	     Elf64_Shdr *shdr = scn->shdr.e64 ?: __elf64_getshdr_rdlock (scn);

	     if (shdr)

	       *dst = shdr->sh_info;

	   }

       }

   }

 return 0;

}

int

internal_function

__elf_getphdrnum_chk_rdlock (Elf *elf, size_t *dst)

{

  int result = __elf_getphdrnum_rdlock (elf, dst);

  /* If the phdrs haven't been created or read in yet then do some

     sanity checking to make sure phnum and phoff are consistent.  */

  if (elf->state.elf.phdr == NULL)

    {

      Elf64_Off off = (elf->class == ELFCLASS32

		       ? elf->state.elf32.ehdr->e_phoff

		       : elf->state.elf64.ehdr->e_phoff);

      if (unlikely (off == 0))

	{

	  *dst = 0;

	  return result;

	}

      if (unlikely (off >= elf->maximum_size))

	{

	  __libelf_seterrno (ELF_E_INVALID_DATA);

	  return -1;

	}

      /* Check for too many sections.  */

      size_t phdr_size = (elf->class == ELFCLASS32

			  ? sizeof (Elf32_Phdr) : sizeof (Elf64_Phdr));

      if (unlikely (*dst > SIZE_MAX / phdr_size))

	{

	  __libelf_seterrno (ELF_E_INVALID_DATA);

	  return -1;

	}

      /* Truncated file?  Don't return more than can be indexed.  */

      if (unlikely (elf->maximum_size - off < *dst * phdr_size))

	*dst = (elf->maximum_size - off) / phdr_size;

    }

  return result;

}

int

elf_getphdrnum (Elf *elf, size_t *dst)

{

  int result;

  if (elf == NULL)

    return -1;

  if (unlikely (elf->kind != ELF_K_ELF))

    {

      __libelf_seterrno (ELF_E_INVALID_HANDLE);

      return -1;

    }

  rwlock_rdlock (elf->lock);

  result = __elf_getphdrnum_chk_rdlock (elf, dst);

  rwlock_unlock (elf->lock);

  return result;

}