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 *
 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
 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 *
 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 *
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 *
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 *
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 *
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  }