1 /*-
2  * Copyright (c) 2006,2008,2010 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 /*
28  * Internal APIs
29  */
30 
31 #include <sys/cdefs.h>
32 
33 #include <assert.h>
34 #include <errno.h>
35 #include <libelf.h>
36 #include <stdlib.h>
37 #include <string.h>
38 
39 #include "_libelf.h"
40 
41 ELFTC_VCSID("$Id$");
42 
43 Elf *
_libelf_allocate_elf(void)44 _libelf_allocate_elf(void)
45 {
46 	Elf *e;
47 
48 	if ((e = malloc(sizeof(*e))) == NULL) {
49 		LIBELF_SET_ERROR(RESOURCE, errno);
50 		return NULL;
51 	}
52 
53 	e->e_activations = 1;
54 	e->e_hdr.e_rawhdr = NULL;
55 	e->e_byteorder   = ELFDATANONE;
56 	e->e_class       = ELFCLASSNONE;
57 	e->e_cmd         = ELF_C_NULL;
58 	e->e_fd          = -1;
59 	e->e_flags	 = 0;
60 	e->e_kind        = ELF_K_NONE;
61 	e->e_parent      = NULL;
62 	e->e_rawfile     = NULL;
63 	e->e_rawsize     = 0;
64 	e->e_version     = LIBELF_PRIVATE(version);
65 
66 	(void) memset(&e->e_u, 0, sizeof(e->e_u));
67 
68 	return (e);
69 }
70 
71 void
_libelf_init_elf(Elf * e,Elf_Kind kind)72 _libelf_init_elf(Elf *e, Elf_Kind kind)
73 {
74 	assert(e != NULL);
75 	assert(e->e_kind == ELF_K_NONE);
76 
77 	e->e_kind = kind;
78 
79 	switch (kind) {
80 	case ELF_K_ELF:
81 		STAILQ_INIT(&e->e_u.e_elf.e_scn);
82 		break;
83 	default:
84 		break;
85 	}
86 }
87 
88 #define	FREE(P)		do {				\
89 		if (P)					\
90 			free(P);			\
91 	} while (0)
92 
93 
94 Elf *
_libelf_release_elf(Elf * e)95 _libelf_release_elf(Elf *e)
96 {
97 	Elf_Arhdr *arh;
98 
99 	switch (e->e_kind) {
100 	case ELF_K_AR:
101 		FREE(e->e_u.e_ar.e_symtab);
102 		break;
103 
104 	case ELF_K_ELF:
105 		switch (e->e_class) {
106 		case ELFCLASS32:
107 			FREE(e->e_u.e_elf.e_ehdr.e_ehdr32);
108 			FREE(e->e_u.e_elf.e_phdr.e_phdr32);
109 			break;
110 		case ELFCLASS64:
111 			FREE(e->e_u.e_elf.e_ehdr.e_ehdr64);
112 			FREE(e->e_u.e_elf.e_phdr.e_phdr64);
113 			break;
114 		}
115 
116 		assert(STAILQ_EMPTY(&e->e_u.e_elf.e_scn));
117 
118 		if (e->e_flags & LIBELF_F_AR_HEADER) {
119 			arh = e->e_hdr.e_arhdr;
120 			FREE(arh->ar_name);
121 			FREE(arh->ar_rawname);
122 			free(arh);
123 		}
124 
125 		break;
126 
127 	default:
128 		break;
129 	}
130 
131 	free(e);
132 
133 	return (NULL);
134 }
135 
136 struct _Libelf_Data *
_libelf_allocate_data(Elf_Scn * s)137 _libelf_allocate_data(Elf_Scn *s)
138 {
139 	struct _Libelf_Data *d;
140 
141 	if ((d = calloc((size_t) 1, sizeof(*d))) == NULL) {
142 		LIBELF_SET_ERROR(RESOURCE, 0);
143 		return (NULL);
144 	}
145 
146 	d->d_scn = s;
147 
148 	return (d);
149 }
150 
151 struct _Libelf_Data *
_libelf_release_data(struct _Libelf_Data * d)152 _libelf_release_data(struct _Libelf_Data *d)
153 {
154 
155 	if (d->d_flags & LIBELF_F_DATA_MALLOCED)
156 		free(d->d_data.d_buf);
157 
158 	free(d);
159 
160 	return (NULL);
161 }
162 
163 Elf_Scn *
_libelf_allocate_scn(Elf * e,size_t ndx)164 _libelf_allocate_scn(Elf *e, size_t ndx)
165 {
166 	Elf_Scn *s;
167 
168 	if ((s = calloc((size_t) 1, sizeof(Elf_Scn))) == NULL) {
169 		LIBELF_SET_ERROR(RESOURCE, errno);
170 		return (NULL);
171 	}
172 
173 	s->s_elf = e;
174 	s->s_ndx = ndx;
175 
176 	STAILQ_INIT(&s->s_data);
177 	STAILQ_INIT(&s->s_rawdata);
178 
179 	STAILQ_INSERT_TAIL(&e->e_u.e_elf.e_scn, s, s_next);
180 
181 	return (s);
182 }
183 
184 Elf_Scn *
_libelf_release_scn(Elf_Scn * s)185 _libelf_release_scn(Elf_Scn *s)
186 {
187 	Elf *e;
188 	struct _Libelf_Data *d, *td;
189 
190 	assert(s != NULL);
191 
192 	STAILQ_FOREACH_SAFE(d, &s->s_data, d_next, td) {
193 		STAILQ_REMOVE(&s->s_data, d, _Libelf_Data, d_next);
194 		d = _libelf_release_data(d);
195 	}
196 
197 	STAILQ_FOREACH_SAFE(d, &s->s_rawdata, d_next, td) {
198 		assert((d->d_flags & LIBELF_F_DATA_MALLOCED) == 0);
199 		STAILQ_REMOVE(&s->s_rawdata, d, _Libelf_Data, d_next);
200 		d = _libelf_release_data(d);
201 	}
202 
203 	e = s->s_elf;
204 
205 	assert(e != NULL);
206 
207 	STAILQ_REMOVE(&e->e_u.e_elf.e_scn, s, _Elf_Scn, s_next);
208 
209 	free(s);
210 
211 	return (NULL);
212 }
213