lib/libelf/gelf_dyn.c

   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 LIBELF_VCSID("$Id$");
  35
  36 GElf_Dyn *
  37 gelf_getdyn(Elf_Data *d, int ndx, GElf_Dyn *dst)
  38 {
  39         int ec;
  40         Elf *e;
  41         Elf_Scn *scn;
  42         Elf32_Dyn *dyn32;
  43         Elf64_Dyn *dyn64;
  44         size_t msz;
  45         uint32_t sh_type;
  46
  47         if (d == NULL || ndx < 0 || dst == NULL ||
  48             (scn = d->d_scn) == NULL ||
  49             (e = scn->s_elf) == NULL) {
  50                 LIBELF_SET_ERROR(ARGUMENT, 0);
  51                 return (NULL);
  52         }
  53
  54         ec = e->e_class;
  55         assert(ec == ELFCLASS32 || ec == ELFCLASS64);
  56
  57         if (ec == ELFCLASS32)
  58                 sh_type = scn->s_shdr.s_shdr32.sh_type;
  59         else
  60                 sh_type = scn->s_shdr.s_shdr64.sh_type;
  61
  62         if (_libelf_xlate_shtype(sh_type) != ELF_T_DYN) {
  63                 LIBELF_SET_ERROR(ARGUMENT, 0);
  64                 return (NULL);
  65         }
  66
  67         msz = _libelf_msize(ELF_T_DYN, ec, e->e_version);
  68
  69         assert(msz > 0);
  70
  71         if (msz * ndx >= d->d_size) {
  72                 LIBELF_SET_ERROR(ARGUMENT, 0);
  73                 return (NULL);
  74         }
  75
  76         if (ec == ELFCLASS32) {
  77                 dyn32 = (Elf32_Dyn *) d->d_buf + ndx;
  78
  79                 dst->d_tag      = dyn32->d_tag;
  80                 dst->d_un.d_val = (Elf64_Xword) dyn32->d_un.d_val;
  81
  82         } else {
  83
  84                 dyn64 = (Elf64_Dyn *) d->d_buf + ndx;
  85
  86                 *dst = *dyn64;
  87         }
  88
  89         return (dst);
  90 }
  91
  92 int
  93 gelf_update_dyn(Elf_Data *d, int ndx, GElf_Dyn *ds)
  94 {
  95         int ec;
  96         Elf *e;
  97         Elf_Scn *scn;
  98         Elf32_Dyn *dyn32;
  99         Elf64_Dyn *dyn64;
 100         size_t msz;
 101         uint32_t sh_type;
 102
 103         if (d == NULL || ndx < 0 || ds == NULL ||
 104             (scn = d->d_scn) == NULL ||
 105             (e = scn->s_elf) == NULL) {
 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_DYN) {
 119                 LIBELF_SET_ERROR(ARGUMENT, 0);
 120                 return (0);
 121         }
 122
 123         msz = _libelf_msize(ELF_T_DYN, ec, e->e_version);
 124         assert(msz > 0);
 125
 126         if (msz * ndx >= d->d_size) {
 127                 LIBELF_SET_ERROR(ARGUMENT, 0);
 128                 return (0);
 129         }
 130
 131         if (ec == ELFCLASS32) {
 132                 dyn32 = (Elf32_Dyn *) d->d_buf + ndx;
 133
 134                 LIBELF_COPY_S32(dyn32, ds, d_tag);
 135                 LIBELF_COPY_U32(dyn32, ds, d_un.d_val);
 136         } else {
 137                 dyn64 = (Elf64_Dyn *) d->d_buf + ndx;
 138
 139                 *dyn64 = *ds;
 140         }
 141
 142         return (1);
 143 }