1/*-
2 * Copyright (c) 2006 Joseph Koshy
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <limits.h>
28
29#include <assert.h>
30#include "gelf.h"
31
32#include "_libelf.h"
33
34GElf_Sym *
35gelf_getsym(Elf_Data *d, int ndx, GElf_Sym *dst)
36{
37        int ec;
38        Elf *e;
39        Elf_Scn *scn;
40        Elf32_Sym *sym32;
41        Elf64_Sym *sym64;
42        size_t msz;
43        uint32_t sh_type;
44
45        if (d == NULL || ndx < 0 || dst == NULL ||
46            (scn = d->d_scn) == NULL ||
47            (e = scn->s_elf) == NULL) {
48                LIBELF_SET_ERROR(ARGUMENT, 0);
49                return (NULL);
50        }
51
52        ec = e->e_class;
53        assert(ec == ELFCLASS32 || ec == ELFCLASS64);
54
55        if (ec == ELFCLASS32)
56                sh_type = scn->s_shdr.s_shdr32.sh_type;
57        else
58                sh_type = scn->s_shdr.s_shdr64.sh_type;
59
60        if (_libelf_xlate_shtype(sh_type) != ELF_T_SYM) {
61                LIBELF_SET_ERROR(ARGUMENT, 0);
62                return (NULL);
63        }
64
65        msz = _libelf_msize(ELF_T_SYM, ec, e->e_version);
66
67        assert(msz > 0);
68
69        if (msz * ndx >= d->d_size) {
70                LIBELF_SET_ERROR(ARGUMENT, 0);
71                return (NULL);
72        }
73
74        if (ec == ELFCLASS32) {
75
76                sym32 = (Elf32_Sym *) d->d_buf + ndx;
77
78                dst->st_name  = sym32->st_name;
79                dst->st_value = (Elf64_Addr) sym32->st_value;
80                dst->st_size  = (Elf64_Xword) sym32->st_size;
81                dst->st_info  = ELF64_ST_INFO(ELF32_ST_BIND(sym32->st_info),
82                    ELF32_ST_TYPE(sym32->st_info));
83                dst->st_other = sym32->st_other;
84                dst->st_shndx = sym32->st_shndx;
85        } else {
86
87                sym64 = (Elf64_Sym *) d->d_buf + ndx;
88
89                *dst = *sym64;
90        }
91
92        return (dst);
93}
94
95int
96gelf_update_sym(Elf_Data *d, int ndx, GElf_Sym *gs)
97{
98        int ec;
99        Elf *e;
100        Elf_Scn *scn;
101        Elf32_Sym *sym32;
102        Elf64_Sym *sym64;
103        size_t msz;
104        uint32_t sh_type;
105
106        if (d == NULL || ndx < 0 || gs == NULL ||
107            (scn = d->d_scn) == NULL ||
108            (e = scn->s_elf) == NULL) {
109                LIBELF_SET_ERROR(ARGUMENT, 0);
110                return (0);
111        }
112
113        ec = e->e_class;
114        assert(ec == ELFCLASS32 || ec == ELFCLASS64);
115
116        if (ec == ELFCLASS32)
117                sh_type = scn->s_shdr.s_shdr32.sh_type;
118        else
119                sh_type = scn->s_shdr.s_shdr64.sh_type;
120
121        if (_libelf_xlate_shtype(sh_type) != ELF_T_SYM) {
122                LIBELF_SET_ERROR(ARGUMENT, 0);
123                return (0);
124        }
125
126        msz = _libelf_msize(ELF_T_SYM, ec, e->e_version);
127        assert(msz > 0);
128
129        if (msz * ndx >= d->d_size) {
130                LIBELF_SET_ERROR(ARGUMENT, 0);
131                return (0);
132        }
133
134        if (ec == ELFCLASS32) {
135                sym32 = (Elf32_Sym *) d->d_buf + ndx;
136
137                sym32->st_name  = gs->st_name;
138                sym32->st_info  = gs->st_info;
139                sym32->st_other = gs->st_other;
140                sym32->st_shndx = gs->st_shndx;
141
142                LIBELF_COPY_U32(sym32, gs, st_value);
143                LIBELF_COPY_U32(sym32, gs, st_size);
144        } else {
145                sym64 = (Elf64_Sym *) d->d_buf + ndx;
146
147                *sym64 = *gs;
148        }
149
150        return (1);
151}
152