include/dlfcn.h

   1 #ifndef _DLFCN_H
   2 #include <dlfcn/dlfcn.h>
   3 #include <link.h>               /* For ElfW.  */
   4 #include <stdbool.h>
   5
   6 /* Internally used flag.  */
   7 #define __RTLD_DLOPEN   0x80000000
   8 #define __RTLD_SPROF    0x40000000
   9 #define __RTLD_OPENEXEC 0x20000000
  10 #define __RTLD_CALLMAP  0x10000000
  11 #define __RTLD_AUDIT    0x08000000
  12 #define __RTLD_SECURE   0x04000000 /* Apply additional security checks.  */
  13 #define __RTLD_NOIFUNC  0x02000000 /* Suppress calling ifunc functions.  */
  14
  15 #define __LM_ID_CALLER  -2
  16
  17 #ifdef SHARED
  18 /* Locally stored program arguments.  */
  19 extern int __dlfcn_argc attribute_hidden;
  20 extern char **__dlfcn_argv attribute_hidden;
  21 #else
  22 /* These variables are defined and initialized in the startup code.  */
  23 extern int __libc_argc attribute_hidden;
  24 extern char **__libc_argv attribute_hidden;
  25
  26 # define __dlfcn_argc __libc_argc
  27 # define __dlfcn_argv __libc_argv
  28 #endif
  29
  30
  31 /* Now define the internal interfaces.  */
  32
  33 #define __libc_dlopen(name) \
  34   __libc_dlopen_mode (name, RTLD_LAZY | __RTLD_DLOPEN)
  35 extern void *__libc_dlopen_mode  (__const char *__name, int __mode);
  36 extern void *__libc_dlsym   (void *__map, __const char *__name);
  37 extern int   __libc_dlclose (void *__map);
  38 libc_hidden_proto (__libc_dlopen_mode)
  39 libc_hidden_proto (__libc_dlsym)
  40 libc_hidden_proto (__libc_dlclose)
  41
  42 /* Locate shared object containing the given address.  */
  43 #ifdef ElfW
  44 extern int _dl_addr (const void *address, Dl_info *info,
  45                      struct link_map **mapp, const ElfW(Sym) **symbolp)
  46      internal_function;
  47 libc_hidden_proto (_dl_addr)
  48 #endif
  49
  50 struct link_map;
  51
  52 /* Close an object previously opened by _dl_open.  */
  53 extern void _dl_close (void *map) attribute_hidden;
  54 /* Same as above, but without locking and safety checks for user
  55    provided map arguments.  */
  56 extern void _dl_close_worker (struct link_map *map) attribute_hidden;
  57
  58 /* Look up NAME in shared object HANDLE (which may be RTLD_DEFAULT or
  59    RTLD_NEXT).  WHO is the calling function, for RTLD_NEXT.  Returns
  60    the symbol value, which may be NULL.  */
  61 extern void *_dl_sym (void *handle, const char *name, void *who)
  62     internal_function;
  63
  64 /* Look up version VERSION of symbol NAME in shared object HANDLE
  65    (which may be RTLD_DEFAULT or RTLD_NEXT).  WHO is the calling
  66    function, for RTLD_NEXT.  Returns the symbol value, which may be
  67    NULL.  */
  68 extern void *_dl_vsym (void *handle, const char *name, const char *version,
  69                        void *who)
  70     internal_function;
  71
  72 /* Call OPERATE, catching errors from `dl_signal_error'.  If there is no
  73    error, *ERRSTRING is set to null.  If there is an error, *ERRSTRING is
  74    set to a string constructed from the strings passed to _dl_signal_error,
  75    and the error code passed is the return value and *OBJNAME is set to
  76    the object name which experienced the problems.  ERRSTRING if nonzero
  77    points to a malloc'ed string which the caller has to free after use.
  78    ARGS is passed as argument to OPERATE.  MALLOCEDP is set to true only
  79    if the returned string is allocated using the libc's malloc.  */
  80 extern int _dl_catch_error (const char **objname, const char **errstring,
  81                             bool *mallocedp, void (*operate) (void *),
  82                             void *args)
  83      internal_function;
  84
  85 /* Helper function for <dlfcn.h> functions.  Runs the OPERATE function via
  86    _dl_catch_error.  Returns zero for success, nonzero for failure; and
  87    arranges for `dlerror' to return the error details.
  88    ARGS is passed as argument to OPERATE.  */
  89 extern int _dlerror_run (void (*operate) (void *), void *args)
  90      internal_function;
  91
  92 #ifdef SHARED
  93 # define DL_CALLER_DECL /* Nothing */
  94 # define DL_CALLER RETURN_ADDRESS (0)
  95 #else
  96 # define DL_CALLER_DECL , void *dl_caller
  97 # define DL_CALLER dl_caller
  98 #endif
  99
 100 struct dlfcn_hook
 101 {
 102   void *(*dlopen) (const char *file, int mode, void *dl_caller);
 103   int (*dlclose) (void *handle);
 104   void *(*dlsym) (void *handle, const char *name, void *dl_caller);
 105   void *(*dlvsym) (void *handle, const char *name, const char *version,
 106                    void *dl_caller);
 107   char *(*dlerror) (void);
 108   int (*dladdr) (const void *address, Dl_info *info);
 109   int (*dladdr1) (const void *address, Dl_info *info,
 110                   void **extra_info, int flags);
 111   int (*dlinfo) (void *handle, int request, void *arg, void *dl_caller);
 112   void *(*dlmopen) (Lmid_t nsid, const char *file, int mode, void *dl_caller);
 113   void *pad[4];
 114 };
 115
 116 extern struct dlfcn_hook *_dlfcn_hook;
 117 libdl_hidden_proto (_dlfcn_hook)
 118
 119 extern void *__dlopen (const char *file, int mode DL_CALLER_DECL)
 120      attribute_hidden;
 121 extern void *__dlmopen (Lmid_t nsid, const char *file, int mode DL_CALLER_DECL)
 122      attribute_hidden;
 123 extern int __dlclose (void *handle)
 124      attribute_hidden;
 125 extern void *__dlsym (void *handle, const char *name DL_CALLER_DECL)
 126      attribute_hidden;
 127 extern void *__dlvsym (void *handle, const char *name, const char *version
 128                        DL_CALLER_DECL)
 129      attribute_hidden;
 130 extern char *__dlerror (void)
 131      attribute_hidden;
 132 extern int __dladdr (const void *address, Dl_info *info)
 133      attribute_hidden;
 134 extern int __dladdr1 (const void *address, Dl_info *info,
 135                       void **extra_info, int flags)
 136      attribute_hidden;
 137 extern int __dlinfo (void *handle, int request, void *arg DL_CALLER_DECL)
 138      attribute_hidden;
 139
 140 #ifndef SHARED
 141 struct link_map;
 142 extern void * __libc_dlsym_private (struct link_map *map, const char *name)
 143      attribute_hidden;
 144 extern void __libc_register_dl_open_hook (struct link_map *map)
 145      attribute_hidden;
 146 extern void __libc_register_dlfcn_hook (struct link_map *map)
 147      attribute_hidden;
 148 #endif
 149
 150 #endif