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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 
28 char *
elf_strptr(elf,idx,offset)29 elf_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 }
122 INTDEF(elf_strptr)
123