1: /* User functions for run-time dynamic loading.
    2:    Copyright (C) 1995-1999,2000,2001,2003,2004,2006
    3:         Free Software Foundation, Inc.
    4:    This file is part of the GNU C Library.
    5: 
    6:    The GNU C Library is free software; you can redistribute it and/or
    7:    modify it under the terms of the GNU Lesser General Public
    8:    License as published by the Free Software Foundation; either
    9:    version 2.1 of the License, or (at your option) any later version.
   10: 
   11:    The GNU C Library is distributed in the hope that it will be useful,
   12:    but WITHOUT ANY WARRANTY; without even the implied warranty of
   13:    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   14:    Lesser General Public License for more details.
   15: 
   16:    You should have received a copy of the GNU Lesser General Public
   17:    License along with the GNU C Library; if not, write to the Free
   18:    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   19:    02111-1307 USA.  */
   20: 
   21: #ifndef _DLFCN_H
   22: #define _DLFCN_H 1
   23: 
   24: #include <features.h>
   25: #define __need_size_t
   26: #include <stddef.h>
   27: 
   28: /* Collect various system dependent definitions and declarations.  */
   29: #include <bits/dlfcn.h>
   30: 
   31: 
   32: #ifdef __USE_GNU
   33: /* If the first argument of `dlsym' or `dlvsym' is set to RTLD_NEXT
   34:    the run-time address of the symbol called NAME in the next shared
   35:    object is returned.  The "next" relation is defined by the order
   36:    the shared objects were loaded.  */
   37: # define RTLD_NEXT      ((void *) -1l)
   38: 
   39: /* If the first argument to `dlsym' or `dlvsym' is set to RTLD_DEFAULT
   40:    the run-time address of the symbol called NAME in the global scope
   41:    is returned.  */
   42: # define RTLD_DEFAULT   ((void *) 0)
   43: 
   44: 
   45: /* Type for namespace indeces.  */
   46: typedef long int Lmid_t;
   47: 
   48: /* Special namespace ID values.  */
   49: # define LM_ID_BASE     0   /* Initial namespace.  */
   50: # define LM_ID_NEWLM    -1 /* For dlmopen: request new namespace.  */
   51: #endif
   52: 
   53: 
   54: __BEGIN_DECLS
   55: 
   56: /* Open the shared object FILE and map it in; return a handle that can be
   57:    passed to `dlsym' to get symbol values from it.  */
   58: extern void *dlopen (__const char *__file, int __mode) __THROW;
   59: 
   60: /* Unmap and close a shared object opened by `dlopen'.
   61:    The handle cannot be used again after calling `dlclose'.  */
   62: extern int dlclose (void *__handle) __THROW __nonnull ((1));
   63: 
   64: /* Find the run-time address in the shared object HANDLE refers to
   65:    of the symbol called NAME.  */
   66: extern void *dlsym (void *__restrict __handle,
   67:                     __const char *__restrict __name) __THROW __nonnull ((2));
   68: 
   69: #ifdef __USE_GNU
   70: /* Like `dlopen', but request object to be allocated in a new namespace.  */
   71: extern void *dlmopen (Lmid_t __nsid, __const char *__file, int __mode) __THROW;
   72: 
   73: /* Find the run-time address in the shared object HANDLE refers to
   74:    of the symbol called NAME with VERSION.  */
   75: extern void *dlvsym (void *__restrict __handle,
   76:                      __const char *__restrict __name,
   77:                      __const char *__restrict __version)
   78:      __THROW __nonnull ((2, 3));
   79: #endif
   80: 
   81: /* When any of the above functions fails, call this function
   82:    to return a string describing the error.  Each call resets
   83:    the error string so that a following call returns null.  */
   84: extern char *dlerror (void) __THROW;
   85: 
   86: 
   87: #ifdef __USE_GNU
   88: /* Structure containing information about object searched using
   89:    `dladdr'.  */
   90: typedef struct
   91: {
   92:   __const char *dli_fname;      /* File name of defining object.  */
   93:   void *dli_fbase;              /* Load address of that object.  */
   94:   __const char *dli_sname;      /* Name of nearest symbol.  */
   95:   void *dli_saddr;              /* Exact value of nearest symbol.  */
   96: } Dl_info;
   97: 
   98: /* Fill in *INFO with the following information about ADDRESS.
   99:    Returns 0 iff no shared object's segments contain that address.  */
  100: extern int dladdr (__const void *__address, Dl_info *__info)
  101:      __THROW __nonnull ((2));
  102: 
  103: /* Same as `dladdr', but additionally sets *EXTRA_INFO according to FLAGS.  */
  104: extern int dladdr1 (__const void *__address, Dl_info *__info,
  105:                     void **__extra_info, int __flags) __THROW __nonnull ((2));
  106: 
  107: /* These are the possible values for the FLAGS argument to `dladdr1'.
  108:    This indicates what extra information is stored at *EXTRA_INFO.
  109:    It may also be zero, in which case the EXTRA_INFO argument is not used.  */
  110: enum
  111:   {
  112:     /* Matching symbol table entry (const ElfNN_Sym *).  */
  113:     RTLD_DL_SYMENT = 1,
  114: 
  115:     /* The object containing the address (struct link_map *).  */
  116:     RTLD_DL_LINKMAP = 2
  117:   };
  118: 
  119: 
  120: /* Get information about the shared object HANDLE refers to.
  121:    REQUEST is from among the values below, and determines the use of ARG.
  122: 
  123:    On success, returns zero.  On failure, returns -1 and records an error
  124:    message to be fetched with `dlerror'.  */
  125: extern int dlinfo (void *__restrict __handle,
  126:                    int __request, void *__restrict __arg)
  127:      __THROW __nonnull ((1, 3));
  128: 
  129: /* These are the possible values for the REQUEST argument to `dlinfo'.  */
  130: enum
  131:   {
  132:     /* Treat ARG as `lmid_t *'; store namespace ID for HANDLE there.  */
  133:     RTLD_DI_LMID = 1,
  134: 
  135:     /* Treat ARG as `struct link_map **';
  136:        store the `struct link_map *' for HANDLE there.  */
  137:     RTLD_DI_LINKMAP = 2,
  138: 
  139:     RTLD_DI_CONFIGADDR = 3,     /* Unsupported, defined by Solaris.  */
  140: 
  141:     /* Treat ARG as `Dl_serinfo *' (see below), and fill in to describe the
  142:        directories that will be searched for dependencies of this object.
  143:        RTLD_DI_SERINFOSIZE fills in just the `dls_cnt' and `dls_size'
  144:        entries to indicate the size of the buffer that must be passed to
  145:        RTLD_DI_SERINFO to fill in the full information.  */
  146:     RTLD_DI_SERINFO = 4,
  147:     RTLD_DI_SERINFOSIZE = 5,
  148: 
  149:     /* Treat ARG as `char *', and store there the directory name used to
  150:        expand $ORIGIN in this shared object's dependency file names.  */
  151:     RTLD_DI_ORIGIN = 6,
  152: 
  153:     RTLD_DI_PROFILENAME = 7,    /* Unsupported, defined by Solaris.  */
  154:     RTLD_DI_PROFILEOUT = 8,     /* Unsupported, defined by Solaris.  */
  155: 
  156:     /* Treat ARG as `size_t *', and store there the TLS module ID
  157:        of this object's PT_TLS segment, as used in TLS relocations;
  158:        store zero if this object does not define a PT_TLS segment.  */
  159:     RTLD_DI_TLS_MODID = 9,
  160: 
  161:     /* Treat ARG as `void **', and store there a pointer to the calling
  162:        thread's TLS block corresponding to this object's PT_TLS segment.
  163:        Store a null pointer if this object does not define a PT_TLS
  164:        segment, or if the calling thread has not allocated a block for it.  */
  165:     RTLD_DI_TLS_DATA = 10,
  166: 
  167:     RTLD_DI_MAX = 10,
  168:   };
  169: 
  170: 
  171: /* This is the type of elements in `Dl_serinfo', below.
  172:    The `dls_name' member points to space in the buffer passed to `dlinfo'.  */
  173: typedef struct
  174: {
  175:   char *dls_name;               /* Name of library search path directory.  */
  176:   unsigned int dls_flags;       /* Indicates where this directory came from. */
  177: } Dl_serpath;
  178: 
  179: /* This is the structure that must be passed (by reference) to `dlinfo' for
  180:    the RTLD_DI_SERINFO and RTLD_DI_SERINFOSIZE requests.  */
  181: typedef struct
  182: {
  183:   size_t dls_size;              /* Size in bytes of the whole buffer.  */
  184:   unsigned int dls_cnt;         /* Number of elements in `dls_serpath'.  */
  185:   Dl_serpath dls_serpath[1];    /* Actually longer, dls_cnt elements.  */
  186: } Dl_serinfo;
  187: #endif /* __USE_GNU */
  188: 
  189: 
  190: __END_DECLS
  191: 
  192: #endif  /* dlfcn.h */