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 <sys/cdefs.h>
28__FBSDID("$FreeBSD$");
29
30#include <sys/limits.h>
31
32#include <assert.h>
33#include <gelf.h>
34
35#include "_libelf.h"
36
37GElf_Rela *
38gelf_getrela(Elf_Data *d, int ndx, GElf_Rela *dst)
39{
40	int ec;
41	Elf *e;
42	Elf_Scn *scn;
43	Elf32_Rela *rela32;
44	Elf64_Rela *rela64;
45	size_t msz;
46	uint32_t sh_type;
47
48	if (d == NULL || ndx < 0 || dst == NULL ||
49	    (scn = d->d_scn) == NULL ||
50	    (e = scn->s_elf) == NULL) {
51		LIBELF_SET_ERROR(ARGUMENT, 0);
52		return (NULL);
53	}
54
55	ec = e->e_class;
56	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
57
58	if (ec == ELFCLASS32)
59		sh_type = scn->s_shdr.s_shdr32.sh_type;
60	else
61		sh_type = scn->s_shdr.s_shdr64.sh_type;
62
63	if (_libelf_xlate_shtype(sh_type) != ELF_T_RELA) {
64		LIBELF_SET_ERROR(ARGUMENT, 0);
65		return (NULL);
66	}
67
68	msz = _libelf_msize(ELF_T_RELA, ec, e->e_version);
69
70	assert(msz > 0);
71
72	if (msz * ndx >= d->d_size) {
73		LIBELF_SET_ERROR(ARGUMENT, 0);
74		return (NULL);
75	}
76
77	if (ec == ELFCLASS32) {
78		rela32 = (Elf32_Rela *) d->d_buf + ndx;
79
80		dst->r_offset = (Elf64_Addr) rela32->r_offset;
81		dst->r_info   = ELF64_R_INFO(
82		    (Elf64_Xword) ELF32_R_SYM(rela32->r_info),
83		    ELF32_R_TYPE(rela32->r_info));
84		dst->r_addend = (Elf64_Sxword) rela32->r_addend;
85
86	} else {
87
88		rela64 = (Elf64_Rela *) d->d_buf + ndx;
89
90		*dst = *rela64;
91	}
92
93	return (dst);
94}
95
96int
97gelf_update_rela(Elf_Data *d, int ndx, GElf_Rela *dr)
98{
99	int ec;
100	Elf *e;
101	Elf_Scn *scn;
102	Elf32_Rela *rela32;
103	Elf64_Rela *rela64;
104	size_t msz;
105	uint32_t sh_type;
106
107	if (d == NULL || ndx < 0 || dr == NULL ||
108	    (scn = d->d_scn) == NULL ||
109	    (e = scn->s_elf) == NULL) {
110		LIBELF_SET_ERROR(ARGUMENT, 0);
111		return (0);
112	}
113
114	ec = e->e_class;
115	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
116
117	if (ec == ELFCLASS32)
118		sh_type = scn->s_shdr.s_shdr32.sh_type;
119	else
120		sh_type = scn->s_shdr.s_shdr64.sh_type;
121
122	if (_libelf_xlate_shtype(sh_type) != ELF_T_RELA) {
123		LIBELF_SET_ERROR(ARGUMENT, 0);
124		return (0);
125	}
126
127	msz = _libelf_msize(ELF_T_RELA, ec, e->e_version);
128	assert(msz > 0);
129
130	if (msz * ndx >= d->d_size) {
131		LIBELF_SET_ERROR(ARGUMENT, 0);
132		return (0);
133	}
134
135	if (ec == ELFCLASS32) {
136		rela32 = (Elf32_Rela *) d->d_buf + ndx;
137
138		LIBELF_COPY_U32(rela32, dr, r_offset);
139
140		if (ELF64_R_SYM(dr->r_info) > ELF32_R_SYM(~0UL) ||
141		    ELF64_R_TYPE(dr->r_info) > ELF32_R_TYPE(~0U)) {
142			LIBELF_SET_ERROR(RANGE, 0);
143			return (0);
144		}
145		rela32->r_info = ELF32_R_INFO(ELF64_R_SYM(dr->r_info),
146		    ELF64_R_TYPE(dr->r_info));
147
148		LIBELF_COPY_S32(rela32, dr, r_addend);
149	} else {
150		rela64 = (Elf64_Rela *) d->d_buf + ndx;
151
152		*rela64 = *dr;
153	}
154
155	return (1);
156}
157