summaryrefslogtreecommitdiff
path: root/src/format/elf/e_elf.c
blob: f7168463c6968084668e985f16cbe16d80dc9552 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162

/* OpenIDA - Outil d'analyse de fichiers binaires
 * e_elf.c - support du format 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 "e_elf.h"


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


#include "elf-int.h"
#include "section.h"
#include "symbol.h"




/******************************************************************************
*                                                                             *
*  Paramètres  : content = contenu binaire à parcourir.                       *
*                length  = taille du contenu en question.                     *
*                                                                             *
*  Description : Prend en charge un nouvel ELF.                               *
*                                                                             *
*  Retour      : Adresse de la structure mise en place ou NULL en cas d'échec.*
*                                                                             *
*  Remarques   : -                                                            *
*                                                                             *
******************************************************************************/

elf_format *load_elf(const uint8_t *content, off_t length)
{
    elf_format *result;                     /* Structure à retourner       */
    bool test;                              /* Bilan d'une initialisation  */

    result = (elf_format *)calloc(1, sizeof(elf_format));

    EXE_FORMAT(result)->content = content;
    EXE_FORMAT(result)->length = length;

    EXE_FORMAT(result)->find_section = (find_section_fc)find_elf_section;
    EXE_FORMAT(result)->get_symbols = (get_symbols_fc)get_elf_symbols;
    EXE_FORMAT(result)->resolve_symbol = (resolve_symbol_fc)resolve_elf_symbol;

    memcpy(&result->header, content, sizeof(Elf32_Ehdr));


    test = read_elf_section_names(result);

    printf("ok ? %d\n", test);

    test = load_elf_symbols(result);

    printf("ok ? %d\n", test);


    return result;

}


/******************************************************************************
*                                                                             *
*  Paramètres  : format  = informations chargées à consulter.                 *
*                labels  = liste des commentaires à insérer. [OUT]            *
*                types   = type des symboles listés. [OUT]                    *
*                offsets = liste des indices des commentaires. [OUT]          *
*                                                                             *
*  Description : Récupère tous les symboles présents dans le contenu binaire. *
*                                                                             *
*  Retour      : Nombre d'éléments mis en place.                              *
*                                                                             *
*  Remarques   : -                                                            *
*                                                                             *
******************************************************************************/

size_t get_elf_symbols(const elf_format *format, char ***labels, SymbolType **types, uint64_t **offsets)
{
    size_t result;                          /* Quantité à retourner        */
    size_t i;                               /* Boucle de parcours          */

    result = format->sym_count;

    *labels = (char **)calloc(result, sizeof(char *));
    *types = (SymbolType *)calloc(result, sizeof(SymbolType));
    *offsets = (uint64_t *)calloc(result, sizeof(uint64_t));

    for (i = 0; i < format->sym_count; i++)
    {
        (*labels)[i] = strdup(format->symbols[i].name);
        (*types)[i] = STP_SECTION;
        (*offsets)[i] = format->symbols[i].address;
    }

    return result;

}


/******************************************************************************
*                                                                             *
*  Paramètres  : format = informations chargées à consulter.                  *
*                label  = étiquette du symbole si trouvé. [OUT]               *
*                type   = type du symbole trouvé. [OUT]                       *
*                offset = adresse à cibler, puis décallage final. [OUT]       *
*                                                                             *
*  Description : Recherche le symbole correspondant à une adresse.            *
*                                                                             *
*  Retour      : true si l'opération a été un succès, false sinon.            *
*                                                                             *
*  Remarques   : -                                                            *
*                                                                             *
******************************************************************************/

bool resolve_elf_symbol(const elf_format *format, char **label, SymbolType *type, uint64_t *offset)
{
    bool result;                            /* Bilan à retourner           */
    size_t best_index;                      /* Meilleur symbole trouvé     */
    uint64_t best_addr;                     /* Meilleure adresse trouvée   */
    size_t i;                               /* Boucle de parcours          */

    best_addr = UINT64_MAX;

    for (i = 0; i < format->sym_count; i++)
        if (format->symbols[i].address <= *offset && (*offset - format->symbols[i].address) < best_addr)
        {
            best_index = i;
            best_addr = *offset - format->symbols[i].address;
        }

    result = (best_addr != UINT64_MAX);

    if (result)
    {
        *label = strdup(format->symbols[best_index].name);
        *type = STP_SECTION;
        *offset -= format->symbols[best_index].address;
    }

    return result;

}