/*      $NetBSD: gelf_dyn.c,v 1.5 2024/03/03 17:37:34 christos Exp $    */

/*-
* Copyright (c) 2006,2008 Joseph Koshy
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#if HAVE_NBTOOL_CONFIG_H
# include "nbtool_config.h"
#endif

#include <sys/cdefs.h>

#include <assert.h>
#include <gelf.h>
#include <limits.h>
#include <stdint.h>

#include "_libelf.h"

__RCSID("$NetBSD: gelf_dyn.c,v 1.5 2024/03/03 17:37:34 christos Exp $");

GElf_Dyn *
gelf_getdyn(Elf_Data *ed, int ndx, GElf_Dyn *dst)
{
       int ec;
       Elf *e;
       size_t msz;
       Elf_Scn *scn;
       Elf32_Dyn *dyn32;
       Elf64_Dyn *dyn64;
       uint32_t sh_type;
       struct _Libelf_Data *d;

       d = (struct _Libelf_Data *) ed;

       if (d == NULL || ndx < 0 || dst == NULL ||
           (scn = d->d_scn) == NULL ||
           (e = scn->s_elf) == NULL) {
               LIBELF_SET_ERROR(ARGUMENT, 0);
               return (NULL);
       }

       ec = e->e_class;
       assert(ec == ELFCLASS32 || ec == ELFCLASS64);

       if (ec == ELFCLASS32)
               sh_type = scn->s_shdr.s_shdr32.sh_type;
       else
               sh_type = scn->s_shdr.s_shdr64.sh_type;

       if (_libelf_xlate_shtype(sh_type) != ELF_T_DYN) {
               LIBELF_SET_ERROR(ARGUMENT, 0);
               return (NULL);
       }

       if ((msz = _libelf_msize(ELF_T_DYN, ec, e->e_version)) == 0)
               return (NULL);

       assert(ndx >= 0);

       if (msz * (size_t) ndx >= d->d_data.d_size) {
               LIBELF_SET_ERROR(ARGUMENT, 0);
               return (NULL);
       }

       if (ec == ELFCLASS32) {
               dyn32 = (Elf32_Dyn *) d->d_data.d_buf + ndx;

               dst->d_tag      = dyn32->d_tag;
               dst->d_un.d_val = (Elf64_Xword) dyn32->d_un.d_val;

       } else {

               dyn64 = (Elf64_Dyn *) d->d_data.d_buf + ndx;

               *dst = *dyn64;
       }

       return (dst);
}

int
gelf_update_dyn(Elf_Data *ed, int ndx, GElf_Dyn *ds)
{
       int ec;
       Elf *e;
       size_t msz;
       Elf_Scn *scn;
       Elf32_Dyn *dyn32;
       Elf64_Dyn *dyn64;
       uint32_t sh_type;
       struct _Libelf_Data *d;

       d = (struct _Libelf_Data *) ed;

       if (d == NULL || ndx < 0 || ds == NULL ||
           (scn = d->d_scn) == NULL ||
           (e = scn->s_elf) == NULL) {
               LIBELF_SET_ERROR(ARGUMENT, 0);
               return (0);
       }

       ec = e->e_class;
       assert(ec == ELFCLASS32 || ec == ELFCLASS64);

       if (ec == ELFCLASS32)
               sh_type = scn->s_shdr.s_shdr32.sh_type;
       else
               sh_type = scn->s_shdr.s_shdr64.sh_type;

       if (_libelf_xlate_shtype(sh_type) != ELF_T_DYN) {
               LIBELF_SET_ERROR(ARGUMENT, 0);
               return (0);
       }

       if ((msz = _libelf_msize(ELF_T_DYN, ec, e->e_version)) == 0)
               return (0);

       assert(ndx >= 0);

       if (msz * (size_t) ndx >= d->d_data.d_size) {
               LIBELF_SET_ERROR(ARGUMENT, 0);
               return (0);
       }

       if (ec == ELFCLASS32) {
               dyn32 = (Elf32_Dyn *) d->d_data.d_buf + ndx;

               LIBELF_COPY_S32(dyn32, ds, d_tag);
               LIBELF_COPY_U32(dyn32, ds, d_un.d_val);
       } else {
               dyn64 = (Elf64_Dyn *) d->d_data.d_buf + ndx;

               *dyn64 = *ds;
       }

       return (1);
}