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 <sys/cdefs.h>
28 
29 #include <assert.h>
30 #include <gelf.h>
31 
32 #include "_libelf.h"
33 
34 ELFTC_VCSID("$Id$");
35 
36 GElf_Sym *
gelf_getsymshndx(Elf_Data * d,Elf_Data * id,int ndx,GElf_Sym * dst,Elf32_Word * shindex)37 gelf_getsymshndx(Elf_Data *d, Elf_Data *id, int ndx, GElf_Sym *dst,
38     Elf32_Word *shindex)
39 {
40 	int ec;
41 	Elf *e;
42 	size_t msz;
43 	Elf_Scn *scn;
44 	uint32_t sh_type;
45 	struct _Libelf_Data *ld, *lid;
46 
47 	ld = (struct _Libelf_Data *) d;
48 	lid = (struct _Libelf_Data *) id;
49 
50 	if (gelf_getsym(d, ndx, dst) == 0)
51 		return (NULL);
52 
53 	if (lid == NULL || (scn = lid->d_scn) == NULL ||
54 	    (e = scn->s_elf) == NULL || (e != ld->d_scn->s_elf) ||
55 	    shindex == NULL) {
56 		LIBELF_SET_ERROR(ARGUMENT, 0);
57 		return (NULL);
58 	}
59 
60 	ec = e->e_class;
61 	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
62 
63 	if (ec == ELFCLASS32)
64 		sh_type = scn->s_shdr.s_shdr32.sh_type;
65 	else
66 		sh_type = scn->s_shdr.s_shdr64.sh_type;
67 
68 	if (_libelf_xlate_shtype(sh_type) != ELF_T_WORD ||
69 	   id->d_type != ELF_T_WORD) {
70 		LIBELF_SET_ERROR(ARGUMENT, 0);
71 		return (NULL);
72 	}
73 
74 	msz = _libelf_msize(ELF_T_WORD, ec, e->e_version);
75 
76 	assert(msz > 0);
77 	assert(ndx >= 0);
78 
79 	if (msz * (size_t) ndx >= id->d_size) {
80 		LIBELF_SET_ERROR(ARGUMENT, 0);
81 		return (NULL);
82 	}
83 
84 	*shindex = ((Elf32_Word *) id->d_buf)[ndx];
85 
86 	return (dst);
87 }
88 
89 int
gelf_update_symshndx(Elf_Data * d,Elf_Data * id,int ndx,GElf_Sym * gs,Elf32_Word xindex)90 gelf_update_symshndx(Elf_Data *d, Elf_Data *id, int ndx, GElf_Sym *gs,
91     Elf32_Word xindex)
92 {
93 	int ec;
94 	Elf *e;
95 	size_t msz;
96 	Elf_Scn *scn;
97 	uint32_t sh_type;
98 	struct _Libelf_Data *ld, *lid;
99 
100 	ld = (struct _Libelf_Data *) d;
101 	lid = (struct _Libelf_Data *) id;
102 
103 	if (gelf_update_sym(d, ndx, gs) == 0)
104 		return (0);
105 
106 	if (lid == NULL || (scn = lid->d_scn) == NULL ||
107 	    (e = scn->s_elf) == NULL || (e != ld->d_scn->s_elf)) {
108 		LIBELF_SET_ERROR(ARGUMENT, 0);
109 		return (0);
110 	}
111 
112 	ec = e->e_class;
113 	assert(ec == ELFCLASS32 || ec == ELFCLASS64);
114 
115 	if (ec == ELFCLASS32)
116 		sh_type = scn->s_shdr.s_shdr32.sh_type;
117 	else
118 		sh_type = scn->s_shdr.s_shdr64.sh_type;
119 
120 	if (_libelf_xlate_shtype(sh_type) != ELF_T_WORD ||
121 	    d->d_type != ELF_T_WORD) {
122 		LIBELF_SET_ERROR(ARGUMENT, 0);
123 		return (0);
124 	}
125 
126 	msz = _libelf_msize(ELF_T_WORD, ec, e->e_version);
127 
128 	assert(msz > 0);
129 	assert(ndx >= 0);
130 
131 	if (msz * (size_t) ndx >= id->d_size) {
132 		LIBELF_SET_ERROR(ARGUMENT, 0);
133 		return (0);
134 	}
135 
136 	*(((Elf32_Word *) id->d_buf) + ndx) = xindex;
137 
138 	return (1);
139 }
140