/* OpenIDA - Outil d'analyse de fichiers binaires
 * section.h - prototypes pour la gestion des sections d'un ELF
 *
 * Copyright (C) 2008 Cyrille Bagard
 *
 *  This file is part of OpenIDA.
 *
 *  OpenIDA 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.
 *
 *  OpenIDA 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 Foobar.  If not, see <http://www.gnu.org/licenses/>.
 */


#include "section.h"


#include <malloc.h>
#include <string.h>


#include "elf-int.h"



/* Teste si une section correspond à celle recherchée. */
bool find_target_elf_section(const elf_format *, const char *, Elf32_Off, Elf32_Shdr *);





/******************************************************************************
*                                                                             *
*  Paramètres  : format = description de l'exécutable à compléter.            *
*                                                                             *
*  Description : Charge en mémoire la liste humaine des sections.             *
*                                                                             *
*  Retour      : Bilan de l'opération.                                        *
*                                                                             *
*  Remarques   : -                                                            *
*                                                                             *
******************************************************************************/

bool read_elf_section_names(elf_format *format)
{
    off_t offset;                           /* Position des données        */
    Elf32_Shdr section;                     /* Section visée               */

    offset = format->header.e_shoff + format->header.e_shentsize * format->header.e_shstrndx;
    if ((offset + sizeof(Elf32_Shdr)) >= EXE_FORMAT(format)->length) return false;

    memcpy(&section, &EXE_FORMAT(format)->content[offset], sizeof(Elf32_Shdr));

    if ((section.sh_offset + section.sh_size) >= EXE_FORMAT(format)->length) return false;

    format->sec_names = (char *)calloc(section.sh_size + 1, sizeof(char));
    format->sec_size = section.sh_size;

    memcpy(format->sec_names, &EXE_FORMAT(format)->content[section.sh_offset], section.sh_size);

    return true;

}


/******************************************************************************
*                                                                             *
*  Paramètres  : format = description de l'exécutable à consulter.            *
*                target = nom de la section recherchée.                       *
*                offset = position de la section à tester.                    *
*                data   = description de la section trouvée. [OUT]            *
*                                                                             *
*  Description : Teste si une section correspond à celle recherchée.          *
*                                                                             *
*  Retour      : Bilan de l'opération.                                        *
*                                                                             *
*  Remarques   : -                                                            *
*                                                                             *
******************************************************************************/

bool find_target_elf_section(const elf_format *format, const char *target, Elf32_Off offset, Elf32_Shdr *data)
{
    bool result;                            /* Conclusion à retourner      */
    Elf32_Shdr section;                     /* Section à analyser          */

    result = false;

    if ((offset + sizeof(Elf32_Shdr)) >= EXE_FORMAT(format)->length) return false;

    memcpy(&section, &EXE_FORMAT(format)->content[offset], sizeof(Elf32_Shdr));

    result = (strcmp(target, &format->sec_names[section.sh_name]) == 0);

    if (result) *data = section;

    return result;

}


/******************************************************************************
*                                                                             *
*  Paramètres  : format  = description de l'exécutable à consulter.           *
*                target  = nom de la section recherchée.                      *
*                offset  = position de la section trouvée. [OUT]              *
*                size    = taille de la section trouvée. [OUT]                *
*                voffset = adresse virtuelle de la section trouvée. [OUT]     *
*                                                                             *
*  Description : Recherche une section donnée au sein de binaire.             *
*                                                                             *
*  Retour      : Bilan de l'opération.                                        *
*                                                                             *
*  Remarques   : -                                                            *
*                                                                             *
******************************************************************************/

bool find_elf_section(const elf_format *format, const char *target, off_t *offset, off_t *size, uint64_t *voffset)
{
    bool result;
    Elf32_Half i;
    Elf32_Shdr data;

    /* Si on perd notre temps... */
    if (format->sec_size == 0) return false;

    result = false;

    for (i = 0; i < format->header.e_shnum; i++)
    {
        if (i == format->header.e_shstrndx) continue;

        if (find_target_elf_section(format, target,
                                    format->header.e_shoff + format->header.e_shentsize * i, &data))
        {
            *offset = data.sh_offset;
            *size = data.sh_size;

            if (voffset != NULL)
                *voffset = data.sh_addr;

            result = true;

        }

    }

    return result;

}