1/* Return string pointer from string section.
2   Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004 Red Hat, Inc.
3   Contributed by Ulrich Drepper <drepper@redhat.com>, 1998.
4
5   This program is free software; you can redistribute it and/or modify
6   it under the terms of the GNU General Public License as published by
7   the Free Software Foundation, version 2.
8
9   This program is distributed in the hope that it will be useful,
10   but WITHOUT ANY WARRANTY; without even the implied warranty of
11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12   GNU General Public License for more details.
13
14   You should have received a copy of the GNU General Public License
15   along with this program; if not, write to the Free Software Foundation,
16   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
17
18#ifdef HAVE_CONFIG_H
19# include <config.h>
20#endif
21
22#include <libelf.h>
23#include <stddef.h>
24
25#include "libelfP.h"
26
27
28char *
29elf_strptr (elf, idx, offset)
30     Elf *elf;
31     size_t idx;
32     size_t offset;
33{
34  if (elf == NULL)
35    return NULL;
36
37  if (elf->kind != ELF_K_ELF)
38    {
39      __libelf_seterrno (ELF_E_INVALID_HANDLE);
40      return NULL;
41    }
42
43  rwlock_rdlock (elf->lock);
44
45  char *result = NULL;
46  Elf_Scn *strscn;
47
48  /* Find the section in the list.  */
49  Elf_ScnList *runp = (elf->class == ELFCLASS32
50		       || (offsetof (struct Elf, state.elf32.scns)
51			   == offsetof (struct Elf, state.elf64.scns))
52		       ? &elf->state.elf32.scns : &elf->state.elf64.scns);
53  while (1)
54    {
55      if (idx < runp->max)
56	{
57	  if (idx < runp->cnt)
58	    strscn = &runp->data[idx];
59	  else
60	    {
61	      __libelf_seterrno (ELF_E_INVALID_INDEX);
62	      goto out;
63	    }
64	  break;
65	}
66
67      idx -= runp->max;
68
69      runp = runp->next;
70      if (runp == NULL)
71	{
72	  __libelf_seterrno (ELF_E_INVALID_INDEX);
73	  goto out;
74	}
75    }
76
77  if (elf->class == ELFCLASS32)
78    {
79      if (unlikely (strscn->shdr.e32->sh_type != SHT_STRTAB))
80	{
81	  /* This is no string section.  */
82	  __libelf_seterrno (ELF_E_INVALID_SECTION);
83	  goto out;
84	}
85
86      if (unlikely (offset >= strscn->shdr.e32->sh_size))
87	{
88	  /* The given offset is too big, it is beyond this section.  */
89	  __libelf_seterrno (ELF_E_OFFSET_RANGE);
90	  goto out;
91	}
92    }
93  else
94    {
95      if (unlikely (strscn->shdr.e64->sh_type != SHT_STRTAB))
96	{
97	  /* This is no string section.  */
98	  __libelf_seterrno (ELF_E_INVALID_SECTION);
99	  goto out;
100	}
101
102      if (unlikely (offset >= strscn->shdr.e64->sh_size))
103	{
104	  /* The given offset is too big, it is beyond this section.  */
105	  __libelf_seterrno (ELF_E_OFFSET_RANGE);
106	  goto out;
107	}
108    }
109
110  if (strscn->rawdata_base == NULL
111      /* Read the section data.  */
112      && __libelf_set_rawdata (strscn) != 0)
113    goto out;
114
115  result = &strscn->rawdata_base[offset];
116
117 out:
118  rwlock_unlock (elf->lock);
119
120  return result;
121}
122INTDEF(elf_strptr)
123