external/bsd/libelf/dist/elf_data.c

   1 /*      $NetBSD: elf_data.c,v 1.2 2009/12/20 23:23:46 thorpej Exp $     */
   2
   3 /*-
   4  * Copyright (c) 2006 Joseph Koshy
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #include <sys/cdefs.h>
  30 /* __FBSDID("$FreeBSD: src/lib/libelf/elf_data.c,v 1.2.10.1.2.1 2009/10/25 01:10:29 kensmith Exp $"); */
  31
  32 #include <assert.h>
  33 #include <errno.h>
  34 #include <libelf.h>
  35 #include <stdlib.h>
  36
  37 #include "_libelf.h"
  38
  39
  40 Elf_Data *
  41 elf_getdata(Elf_Scn *s, Elf_Data *d)
  42 {
  43         Elf *e;
  44         char *dst;
  45         size_t fsz, msz, count;
  46         int elfclass, elftype;
  47         unsigned int sh_type;
  48         uint64_t sh_align, sh_offset, sh_size;
  49         void (*xlate)(char *_d, char *_s, size_t _c, int _swap);
  50
  51         if (s == NULL || (e = s->s_elf) == NULL || e->e_kind != ELF_K_ELF ||
  52             (d != NULL && s != d->d_scn)) {
  53                 LIBELF_SET_ERROR(ARGUMENT, 0);
  54                 return (NULL);
  55         }
  56
  57         if (d == NULL && (d = STAILQ_FIRST(&s->s_data)) != NULL)
  58                 return (d);
  59
  60         if (d != NULL)
  61                 return (STAILQ_NEXT(d, d_next));
  62
  63         if (e->e_rawfile == NULL) {
  64                 LIBELF_SET_ERROR(SEQUENCE, 0);
  65                 return (NULL);
  66         }
  67
  68         elfclass = e->e_class;
  69
  70         assert(elfclass == ELFCLASS32 || elfclass == ELFCLASS64);
  71
  72         if (elfclass == ELFCLASS32) {
  73                 sh_type   = s->s_shdr.s_shdr32.sh_type;
  74                 sh_offset = (uint64_t) s->s_shdr.s_shdr32.sh_offset;
  75                 sh_size   = (uint64_t) s->s_shdr.s_shdr32.sh_size;
  76                 sh_align  = (uint64_t) s->s_shdr.s_shdr32.sh_addralign;
  77         } else {
  78                 sh_type   = s->s_shdr.s_shdr64.sh_type;
  79                 sh_offset = s->s_shdr.s_shdr64.sh_offset;
  80                 sh_size   = s->s_shdr.s_shdr64.sh_size;
  81                 sh_align  = s->s_shdr.s_shdr64.sh_addralign;
  82         }
  83
  84         if ((elftype = _libelf_xlate_shtype(sh_type)) < ELF_T_FIRST ||
  85             elftype > ELF_T_LAST ||
  86             sh_offset + sh_size > (uint64_t) e->e_rawsize) {
  87                 LIBELF_SET_ERROR(SECTION, 0);
  88                 return (NULL);
  89         }
  90
  91         if ((fsz = (elfclass == ELFCLASS32 ? elf32_fsize : elf64_fsize)(elftype,
  92                  (size_t) 1, e->e_version)) == 0) {
  93                 LIBELF_SET_ERROR(UNIMPL, 0);
  94                 return (NULL);
  95         }
  96
  97
  98         if (sh_size % fsz) {
  99                 LIBELF_SET_ERROR(SECTION, 0);
 100                 return (NULL);
 101         }
 102
 103         count = sh_size / fsz;
 104
 105         msz = _libelf_msize(elftype, elfclass, e->e_version);
 106
 107         assert(msz > 0);
 108
 109         if ((dst = malloc(msz*count)) == NULL) {
 110                 LIBELF_SET_ERROR(RESOURCE, 0);
 111                 return (NULL);
 112         }
 113
 114         if ((d = _libelf_allocate_data(s)) == NULL)
 115                 return (NULL);
 116
 117         d->d_buf     = dst;
 118         d->d_off     = 0;
 119         d->d_align   = sh_align;
 120         d->d_size    = msz * count;
 121         d->d_type    = elftype;
 122         d->d_version = e->e_version;
 123
 124         d->d_flags  |= LIBELF_F_MALLOCED;
 125         STAILQ_INSERT_TAIL(&s->s_data, d, d_next);
 126
 127         xlate = _libelf_get_translator(elftype, ELF_TOMEMORY, elfclass);
 128         (*xlate)(d->d_buf, e->e_rawfile + sh_offset, count, e->e_byteorder !=
 129             _libelf_host_byteorder());
 130
 131         return (d);
 132 }
 133
 134 Elf_Data *
 135 elf_newdata(Elf_Scn *s)
 136 {
 137         Elf *e;
 138         Elf_Data *d;
 139
 140         if (s == NULL || (e = s->s_elf) == NULL ||
 141             e->e_kind != ELF_K_ELF) {
 142                 LIBELF_SET_ERROR(ARGUMENT, 0);
 143                 return (NULL);
 144         }
 145
 146         /*
 147          * elf_newdata() has to append a data descriptor, so
 148          * bring in existing section data if not already present.
 149          */
 150         if (e->e_rawfile && s->s_size > 0 && STAILQ_EMPTY(&s->s_data))
 151                 if (elf_getdata(s, NULL) == NULL)
 152                         return (NULL);
 153
 154         if ((d = malloc(sizeof(Elf_Data))) == NULL) {
 155                 LIBELF_SET_ERROR(RESOURCE, errno);
 156                 return (NULL);
 157         }
 158
 159         STAILQ_INSERT_TAIL(&s->s_data, d, d_next);
 160         d->d_flags = 0;
 161         d->d_scn = s;
 162
 163         d->d_align = 1;
 164         d->d_buf = NULL;
 165         d->d_off = (uint64_t) ~0;
 166         d->d_size = 0;
 167         d->d_type = ELF_T_BYTE;
 168         d->d_version = LIBELF_PRIVATE(version);
 169
 170         (void) elf_flagscn(s, ELF_C_SET, ELF_F_DIRTY);
 171
 172         return (d);
 173 }
 174
 175 /*
 176  * Retrieve a data descriptor for raw (untranslated) data for section
 177  * `s'.
 178  */
 179
 180 Elf_Data *
 181 elf_rawdata(Elf_Scn *s, Elf_Data *d)
 182 {
 183         Elf *e;
 184         int elf_class;
 185         uint64_t sh_align, sh_offset, sh_size;
 186
 187         if (s == NULL || (e = s->s_elf) == NULL ||
 188             e->e_kind != ELF_K_ELF || e->e_rawfile == NULL) {
 189                 LIBELF_SET_ERROR(ARGUMENT, 0);
 190                 return (NULL);
 191         }
 192
 193         if (d == NULL && (d = STAILQ_FIRST(&s->s_rawdata)) != NULL)
 194                 return (d);
 195
 196         if (d != NULL)
 197                 return (STAILQ_NEXT(d, d_next));
 198
 199         elf_class = e->e_class;
 200
 201         assert(elf_class == ELFCLASS32 || elf_class == ELFCLASS64);
 202
 203         if (elf_class == ELFCLASS32) {
 204                 sh_offset = (uint64_t) s->s_shdr.s_shdr32.sh_offset;
 205                 sh_size   = (uint64_t) s->s_shdr.s_shdr32.sh_size;
 206                 sh_align  = (uint64_t) s->s_shdr.s_shdr32.sh_addralign;
 207         } else {
 208                 sh_offset = s->s_shdr.s_shdr64.sh_offset;
 209                 sh_size   = s->s_shdr.s_shdr64.sh_size;
 210                 sh_align  = s->s_shdr.s_shdr64.sh_addralign;
 211         }
 212
 213         if ((d = _libelf_allocate_data(s)) == NULL)
 214                 return (NULL);
 215
 216         d->d_buf     = e->e_rawfile + sh_offset;
 217         d->d_off     = 0;
 218         d->d_align   = sh_align;
 219         d->d_size    = sh_size;
 220         d->d_type    = ELF_T_BYTE;
 221         d->d_version = e->e_version;
 222
 223         STAILQ_INSERT_TAIL(&s->s_rawdata, d, d_next);
 224
 225         return (d);
 226 }