/*

 * x.elfext.c -- handle ELF format extensions

 * Copyright (C) 2002 - 2006 Michael Riepe

 * 

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Library General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 * 

 * This library 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

 * Library General Public License for more details.

 * 

 * You should have received a copy of the GNU Library General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

#include <private.h>

#ifndef lint

static const char rcsid[] = "@(#) $Id: x.elfext.c,v 1.3 2006/07/07 22:17:50 michael Exp $";

#endif /* lint */

int

elf_getphnum(Elf *elf, size_t *resultp) {

    if (!elf) {

	return LIBELF_FAILURE;

    }

    elf_assert(elf->e_magic == ELF_MAGIC);

    if (elf->e_kind != ELF_K_ELF) {

	seterr(ERROR_NOTELF);

	return LIBELF_FAILURE;

    }

    if (!elf->e_ehdr && !_elf_cook(elf)) {

	return LIBELF_FAILURE;

    }

    if (resultp) {

	*resultp = elf->e_phnum;

    }

    return LIBELF_SUCCESS;

}

int

elf_getshnum(Elf *elf, size_t *resultp) {

    size_t num = 0;

    Elf_Scn *scn;

    if (!elf) {

	return LIBELF_FAILURE;

    }

    elf_assert(elf->e_magic == ELF_MAGIC);

    if (elf->e_kind != ELF_K_ELF) {

	seterr(ERROR_NOTELF);

	return LIBELF_FAILURE;

    }

    if (!elf->e_ehdr && !_elf_cook(elf)) {

	return LIBELF_FAILURE;

    }

    if ((scn = elf->e_scn_n)) {

	num = scn->s_index + 1;

    }

    if (resultp) {

	*resultp = num;

    }

    return LIBELF_SUCCESS;

}

int

elf_getshstrndx(Elf *elf, size_t *resultp) {

    size_t num = 0;

    size_t dummy;

    Elf_Scn *scn;

    if (!elf) {

	return LIBELF_FAILURE;

    }

    elf_assert(elf->e_magic == ELF_MAGIC);

    if (resultp == NULL) {

	resultp = &dummy;	/* handle NULL pointer gracefully */

    }

    if (elf->e_kind != ELF_K_ELF) {

	seterr(ERROR_NOTELF);

	return LIBELF_FAILURE;

    }

    if (!elf->e_ehdr && !_elf_cook(elf)) {

	return LIBELF_FAILURE;

    }

    if (elf->e_class == ELFCLASS32) {

	num = ((Elf32_Ehdr*)elf->e_ehdr)->e_shstrndx;

    }

#if __LIBELF64

    else if (elf->e_class == ELFCLASS64) {

	num = ((Elf64_Ehdr*)elf->e_ehdr)->e_shstrndx;

    }

#endif /* __LIBELF64 */

    else {

	if (valid_class(elf->e_class)) {

	    seterr(ERROR_UNIMPLEMENTED);

	}

	else {

	    seterr(ERROR_UNKNOWN_CLASS);

	}

	return LIBELF_FAILURE;

    }

    if (num != SHN_XINDEX) {

	*resultp = num;

	return LIBELF_SUCCESS;

    }

    /*

     * look at first section header

     */

    if (!(scn = elf->e_scn_1)) {

	seterr(ERROR_NOSUCHSCN);

	return LIBELF_FAILURE;

    }

    elf_assert(scn->s_magic == SCN_MAGIC);

#if __LIBELF64

    if (elf->e_class == ELFCLASS64) {

	*resultp = scn->s_shdr64.sh_link;

	return LIBELF_SUCCESS;

    }

#endif /* __LIBELF64 */

    *resultp = scn->s_shdr32.sh_link;

    return LIBELF_SUCCESS;

}

int

elfx_update_shstrndx(Elf *elf, size_t value) {

    size_t extvalue = 0;

    Elf_Scn *scn;

    if (!elf) {

	return LIBELF_FAILURE;

    }

    elf_assert(elf->e_magic == ELF_MAGIC);

    if (value >= SHN_LORESERVE) {

	extvalue = value;

	value = SHN_XINDEX;

    }

    if (elf->e_kind != ELF_K_ELF) {

	seterr(ERROR_NOTELF);

	return LIBELF_FAILURE;

    }

    if (!elf->e_ehdr && !_elf_cook(elf)) {

	return LIBELF_FAILURE;

    }

    if (!(scn = _elf_first_scn(elf))) {

	return LIBELF_FAILURE;

    }

    elf_assert(scn->s_magic == SCN_MAGIC);

    if (elf->e_class == ELFCLASS32) {

	((Elf32_Ehdr*)elf->e_ehdr)->e_shstrndx = value;

	scn->s_shdr32.sh_link = extvalue;

    }

#if __LIBELF64

    else if (elf->e_class == ELFCLASS64) {

	((Elf64_Ehdr*)elf->e_ehdr)->e_shstrndx = value;

	scn->s_shdr64.sh_link = extvalue;

    }

#endif /* __LIBELF64 */

    else {

	if (valid_class(elf->e_class)) {

	    seterr(ERROR_UNIMPLEMENTED);

	}

	else {

	    seterr(ERROR_UNKNOWN_CLASS);

	}

	return LIBELF_FAILURE;

    }

    elf->e_ehdr_flags |= ELF_F_DIRTY;

    scn->s_shdr_flags |= ELF_F_DIRTY;

    return LIBELF_SUCCESS;

}