contrib/elftoolchain/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 <assert.h>
  28 #include <gelf.h>
  29 #include <limits.h>
  30 #include <stdint.h>
  31
  32 #include "_libelf.h"
  33
  34 ELFTC_VCSID("$Id: gelf_dyn.c 3177 2015-03-30 18:19:41Z emaste $");
  35
  36 GElf_Dyn *
  37 gelf_getdyn(Elf_Data *ed, int ndx, GElf_Dyn *dst)
  38 {
  39         int ec;
  40         Elf *e;
  41         size_t msz;
  42         Elf_Scn *scn;
  43         Elf32_Dyn *dyn32;
  44         Elf64_Dyn *dyn64;
  45         uint32_t sh_type;
  46         struct _Libelf_Data *d;
  47
  48         d = (struct _Libelf_Data *) ed;
  49
  50         if (d == NULL || ndx < 0 || dst == NULL ||
  51             (scn = d->d_scn) == NULL ||
  52             (e = scn->s_elf) == NULL) {
  53                 LIBELF_SET_ERROR(ARGUMENT, 0);
  54                 return (NULL);
  55         }
  56
  57         ec = e->e_class;
  58         assert(ec == ELFCLASS32 || ec == ELFCLASS64);
  59
  60         if (ec == ELFCLASS32)
  61                 sh_type = scn->s_shdr.s_shdr32.sh_type;
  62         else
  63                 sh_type = scn->s_shdr.s_shdr64.sh_type;
  64
  65         if (_libelf_xlate_shtype(sh_type) != ELF_T_DYN) {
  66                 LIBELF_SET_ERROR(ARGUMENT, 0);
  67                 return (NULL);
  68         }
  69
  70         msz = _libelf_msize(ELF_T_DYN, ec, e->e_version);
  71
  72         assert(msz > 0);
  73         assert(ndx >= 0);
  74
  75         if (msz * (size_t) ndx >= d->d_data.d_size) {
  76                 LIBELF_SET_ERROR(ARGUMENT, 0);
  77                 return (NULL);
  78         }
  79
  80         if (ec == ELFCLASS32) {
  81                 dyn32 = (Elf32_Dyn *) d->d_data.d_buf + ndx;
  82
  83                 dst->d_tag      = dyn32->d_tag;
  84                 dst->d_un.d_val = (Elf64_Xword) dyn32->d_un.d_val;
  85
  86         } else {
  87
  88                 dyn64 = (Elf64_Dyn *) d->d_data.d_buf + ndx;
  89
  90                 *dst = *dyn64;
  91         }
  92
  93         return (dst);
  94 }
  95
  96 int
  97 gelf_update_dyn(Elf_Data *ed, int ndx, GElf_Dyn *ds)
  98 {
  99         int ec;
 100         Elf *e;
 101         size_t msz;
 102         Elf_Scn *scn;
 103         Elf32_Dyn *dyn32;
 104         Elf64_Dyn *dyn64;
 105         uint32_t sh_type;
 106         struct _Libelf_Data *d;
 107
 108         d = (struct _Libelf_Data *) ed;
 109
 110         if (d == NULL || ndx < 0 || ds == NULL ||
 111             (scn = d->d_scn) == NULL ||
 112             (e = scn->s_elf) == NULL) {
 113                 LIBELF_SET_ERROR(ARGUMENT, 0);
 114                 return (0);
 115         }
 116
 117         ec = e->e_class;
 118         assert(ec == ELFCLASS32 || ec == ELFCLASS64);
 119
 120         if (ec == ELFCLASS32)
 121                 sh_type = scn->s_shdr.s_shdr32.sh_type;
 122         else
 123                 sh_type = scn->s_shdr.s_shdr64.sh_type;
 124
 125         if (_libelf_xlate_shtype(sh_type) != ELF_T_DYN) {
 126                 LIBELF_SET_ERROR(ARGUMENT, 0);
 127                 return (0);
 128         }
 129
 130         msz = _libelf_msize(ELF_T_DYN, ec, e->e_version);
 131
 132         assert(msz > 0);
 133         assert(ndx >= 0);
 134
 135         if (msz * (size_t) ndx >= d->d_data.d_size) {
 136                 LIBELF_SET_ERROR(ARGUMENT, 0);
 137                 return (0);
 138         }
 139
 140         if (ec == ELFCLASS32) {
 141                 dyn32 = (Elf32_Dyn *) d->d_data.d_buf + ndx;
 142
 143                 LIBELF_COPY_S32(dyn32, ds, d_tag);
 144                 LIBELF_COPY_U32(dyn32, ds, d_un.d_val);
 145         } else {
 146                 dyn64 = (Elf64_Dyn *) d->d_data.d_buf + ndx;
 147
 148                 *dyn64 = *ds;
 149         }
 150
 151         return (1);
 152 }