1 /* Optional code to distinguish library flavours.
2    Copyright (C) 1998-2021 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4 
5    The GNU C Library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 2.1 of the License, or (at your option) any later version.
9 
10    The GNU C Library is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    Lesser General Public License for more details.
14 
15    You should have received a copy of the GNU Lesser General Public
16    License along with the GNU C Library; if not, see
17    <https://www.gnu.org/licenses/>.  */
18 
19 #ifndef _DL_LIBRECON_H
20 
21 #include <sysdeps/unix/sysv/linux/dl-librecon.h>
22 
23 #define DISTINGUISH_LIB_VERSIONS \
24   do									      \
25     {									      \
26       /* We have to find out whether the binary is linked against	      \
27 	 libc 5 or glibc.  We do this by looking at all the DT_NEEDED	      \
28 	 entries.  If one is libc.so.5 this is a libc 5 linked binary.  */    \
29       if (main_map->l_info[DT_NEEDED])					      \
30 	{								      \
31 	  /* We have dependencies.  */					      \
32 	  const ElfW(Dyn) *d;						      \
33 	  const char *strtab;						      \
34 									      \
35 	  strtab = (const char *) D_PTR (main_map, l_info[DT_STRTAB]);	      \
36 									      \
37 	  for (d = main_map->l_ld; d->d_tag != DT_NULL; ++d)		      \
38 	    if (d->d_tag == DT_NEEDED					      \
39 		&& strcmp (strtab + d->d_un.d_val, "libc.so.5") == 0)	      \
40 	      break;							      \
41 									      \
42 	  /* We print a `5' or `6' depending on the outcome.  */	      \
43 	  _dl_printf (d->d_tag != DT_NULL ? "5\n" : "6\n");		      \
44 	}								      \
45     }									      \
46   while (0)
47 
48 /* Recognizing extra environment variables.  */
49 #define EXTRA_LD_ENVVARS \
50   case 15:								      \
51     if (memcmp (envline, "LIBRARY_VERSION", 15) == 0)			      \
52       GLRO(dl_correct_cache_id) = envline[16] == '5' ? 2 : 3;		      \
53     break;								      \
54 
55 /* Extra unsecure variables.  The names are all stuffed in a single
56    string which means they have to be terminated with a '\0' explicitly.  */
57 #define EXTRA_UNSECURE_ENVVARS \
58   "LD_AOUT_LIBRARY_PATH\0"						      \
59   "LD_AOUT_PRELOAD\0"
60 
61 #endif /* dl-librecon.h */
62