sysdeps/generic/dl-cache.h

   1 /* Support for reading /etc/ld.so.cache files written by Linux ldconfig.
   2    Copyright (C) 1999, 2000 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 Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    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    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #ifndef _DL_CACHE_DEFAULT_ID
  21 # define _DL_CACHE_DEFAULT_ID   3
  22 #endif
  23
  24 #ifndef _dl_cache_check_flags
  25 # define _dl_cache_check_flags(flags)                   \
  26   ((flags) == 1 || (flags) == _DL_CACHE_DEFAULT_ID)
  27 #endif
  28
  29 #ifndef LD_SO_CACHE
  30 # define LD_SO_CACHE SYSCONFDIR "/ld.so.cache"
  31 #endif
  32
  33 #define CACHEMAGIC "ld.so-1.7.0"
  34
  35 /* libc5 and glibc 2.0/2.1 use the same format.  For glibc 2.2 another
  36    format has been added in a compatible way:
  37    The beginning of the string table is used for the new table:
  38         old_magic
  39         nlibs
  40         libs[0]
  41         ...
  42         libs[nlibs-1]
  43         pad, new magic needs to be aligned
  44              - this is string[0] for the old format
  45         new magic - this is string[0] for the new format
  46         newnlibs
  47         ...
  48         newlibs[0]
  49         ...
  50         newlibs[newnlibs-1]
  51         string 1
  52         string 2
  53         ...
  54 */
  55 struct file_entry
  56 {
  57   int flags;            /* This is 1 for an ELF library.  */
  58   unsigned int key, value; /* String table indices.  */
  59 };
  60
  61 struct cache_file
  62 {
  63   char magic[sizeof CACHEMAGIC - 1];
  64   unsigned int nlibs;
  65   struct file_entry libs[0];
  66 };
  67
  68 #define CACHEMAGIC_NEW "glibc-ld.so.cache"
  69 #define CACHE_VERSION "1.0"
  70
  71
  72 struct file_entry_new
  73 {
  74   int flags;                    /* This is 1 for an ELF library.  */
  75   unsigned int key, value;      /* String table indices.  */
  76   unsigned long hwcap;          /* Hwcap entry.  */
  77 };
  78
  79 struct cache_file_new
  80 {
  81   char magic[sizeof CACHEMAGIC_NEW - 1];
  82   char version[sizeof CACHE_VERSION - 1];
  83   unsigned int nlibs;           /* Number of entries.  */
  84   unsigned int len_strings;     /* Size of string table. */
  85   unsigned int unused[4];       /* Leave space for future extensions.  */
  86   struct file_entry_new libs[0]; /* Entries describing libraries.  */
  87   /* After this the string table of size len_strings is found.  */
  88 };
  89
  90 /* Used to align cache_file_new.  */
  91 #define ALIGN_CACHE(addr)                               \
  92 (((addr) + __alignof__ (struct cache_file_new) -1)      \
  93  & (~(__alignof__ (struct cache_file_new) - 1)))
  94
  95 static int
  96 _dl_cache_libcmp (const char *p1, const char *p2)
  97 {
  98   while (*p1 != '\0')
  99     {
 100       if (*p1 >= '0' && *p1 <= '9')
 101         {
 102           if (*p2 >= '0' && *p2 <= '9')
 103             {
 104               /* Must compare this numerically.  */
 105               int val1;
 106               int val2;
 107
 108               val1 = *p1++ - '0';
 109               val2 = *p2++ - '0';
 110               while (*p1 >= '0' && *p1 <= '9')
 111                 val1 = val1 * 10 + *p1++ - '0';
 112               while (*p2 >= '0' && *p2 <= '9')
 113                 val2 = val2 * 10 + *p2++ - '0';
 114               if (val1 != val2)
 115                 return val1 - val2;
 116             }
 117           else
 118             return 1;
 119         }
 120       else if (*p2 >= '0' && *p2 <= '9')
 121         return -1;
 122       else if (*p1 != *p2)
 123         return *p1 - *p2;
 124       else
 125         {
 126           ++p1;
 127           ++p2;
 128         }
 129     }
 130   return *p1 - *p2;
 131 }