1 /*-
2  * Copyright (c) 2006,2008 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 <assert.h>
28 #include <gelf.h>
29 
30 #include "_libelf.h"
31 
32 ELFTC_VCSID("$Id: gelf_symshndx.c 3174 2015-03-27 17:13:41Z emaste $");
33 
34 GElf_Sym *
gelf_getsymshndx(Elf_Data * d,Elf_Data * id,int ndx,GElf_Sym * dst,Elf32_Word * shindex)35 gelf_getsymshndx(Elf_Data *d, Elf_Data *id, int ndx, GElf_Sym *dst,
36     Elf32_Word *shindex)
37 {
38 	int ec;
39 	Elf *e;
40 	size_t msz;
41 	Elf_Scn *scn;
42 	uint32_t sh_type;
43 	struct _Libelf_Data *ld, *lid;
44 
45 	ld = (struct _Libelf_Data *) d;
46 	lid = (struct _Libelf_Data *) id;
47 
48 	if (gelf_getsym(d, ndx, dst) == 0)
49 		return (NULL);
50 
51 	if (lid == NULL || (scn = lid->d_scn) == NULL ||
52 	    (e = scn->s_elf) == NULL || (e != ld->d_scn->s_elf) ||
53 	    shindex == NULL) {
54 		LIBELF_SET_ERROR(ARGUMENT, 0);
55 		return (NULL);
56 	}
57 
58 	ec = e->e_class;
59 	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
60 
61 	if (ec == ELFCLASS32)
62 		sh_type = scn->s_shdr.s_shdr32.sh_type;
63 	else
64 		sh_type = scn->s_shdr.s_shdr64.sh_type;
65 
66 	if (_libelf_xlate_shtype(sh_type) != ELF_T_WORD ||
67 	   id->d_type != ELF_T_WORD) {
68 		LIBELF_SET_ERROR(ARGUMENT, 0);
69 		return (NULL);
70 	}
71 
72 	msz = _libelf_msize(ELF_T_WORD, ec, e->e_version);
73 
74 	assert(msz > 0);
75 	assert(ndx >= 0);
76 
77 	if (msz * (size_t) ndx >= id->d_size) {
78 		LIBELF_SET_ERROR(ARGUMENT, 0);
79 		return (NULL);
80 	}
81 
82 	*shindex = ((Elf32_Word *) id->d_buf)[ndx];
83 
84 	return (dst);
85 }
86 
87 int
gelf_update_symshndx(Elf_Data * d,Elf_Data * id,int ndx,GElf_Sym * gs,Elf32_Word xindex)88 gelf_update_symshndx(Elf_Data *d, Elf_Data *id, int ndx, GElf_Sym *gs,
89     Elf32_Word xindex)
90 {
91 	int ec;
92 	Elf *e;
93 	size_t msz;
94 	Elf_Scn *scn;
95 	uint32_t sh_type;
96 	struct _Libelf_Data *ld, *lid;
97 
98 	ld = (struct _Libelf_Data *) d;
99 	lid = (struct _Libelf_Data *) id;
100 
101 	if (gelf_update_sym(d, ndx, gs) == 0)
102 		return (0);
103 
104 	if (lid == NULL || (scn = lid->d_scn) == NULL ||
105 	    (e = scn->s_elf) == NULL || (e != ld->d_scn->s_elf)) {
106 		LIBELF_SET_ERROR(ARGUMENT, 0);
107 		return (0);
108 	}
109 
110 	ec = e->e_class;
111 	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
112 
113 	if (ec == ELFCLASS32)
114 		sh_type = scn->s_shdr.s_shdr32.sh_type;
115 	else
116 		sh_type = scn->s_shdr.s_shdr64.sh_type;
117 
118 	if (_libelf_xlate_shtype(sh_type) != ELF_T_WORD ||
119 	    d->d_type != ELF_T_WORD) {
120 		LIBELF_SET_ERROR(ARGUMENT, 0);
121 		return (0);
122 	}
123 
124 	msz = _libelf_msize(ELF_T_WORD, ec, e->e_version);
125 
126 	assert(msz > 0);
127 	assert(ndx >= 0);
128 
129 	if (msz * (size_t) ndx >= id->d_size) {
130 		LIBELF_SET_ERROR(ARGUMENT, 0);
131 		return (0);
132 	}
133 
134 	*(((Elf32_Word *) id->d_buf) + ndx) = xindex;
135 
136 	return (1);
137 }
138