1/* User functions for run-time dynamic loading.
2 Copyright (C) 1995-2018 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 <http://www.gnu.org/licenses/>. */
18
19#ifndef _DLFCN_H
20#define _DLFCN_H 1
21
22#include <features.h>
23#define __need_size_t
24#include <stddef.h>
25
26/* Collect various system dependent definitions and declarations. */
27#include <bits/dlfcn.h>
28
29
30#ifdef __USE_GNU
31/* If the first argument of `dlsym' or `dlvsym' is set to RTLD_NEXT
32 the run-time address of the symbol called NAME in the next shared
33 object is returned. The "next" relation is defined by the order
34 the shared objects were loaded. */
35# define RTLD_NEXT ((void *) -1l)
36
37/* If the first argument to `dlsym' or `dlvsym' is set to RTLD_DEFAULT
38 the run-time address of the symbol called NAME in the global scope
39 is returned. */
40# define RTLD_DEFAULT ((void *) 0)
41
42
43/* Type for namespace indeces. */
44typedef long int Lmid_t;
45
46/* Special namespace ID values. */
47# define LM_ID_BASE 0 /* Initial namespace. */
48# define LM_ID_NEWLM -1 /* For dlmopen: request new namespace. */
49#endif
50
51
52__BEGIN_DECLS
53
54/* Open the shared object FILE and map it in; return a handle that can be
55 passed to `dlsym' to get symbol values from it. */
56extern void *dlopen (const char *__file, int __mode) __THROWNL;
57
58/* Unmap and close a shared object opened by `dlopen'.
59 The handle cannot be used again after calling `dlclose'. */
60extern int dlclose (void *__handle) __THROWNL __nonnull ((1));
61
62/* Find the run-time address in the shared object HANDLE refers to
63 of the symbol called NAME. */
64extern void *dlsym (void *__restrict __handle,
65 const char *__restrict __name) __THROW __nonnull ((2));
66
67#ifdef __USE_GNU
68/* Like `dlopen', but request object to be allocated in a new namespace. */
69extern void *dlmopen (Lmid_t __nsid, const char *__file, int __mode) __THROWNL;
70
71/* Find the run-time address in the shared object HANDLE refers to
72 of the symbol called NAME with VERSION. */
73extern void *dlvsym (void *__restrict __handle,
74 const char *__restrict __name,
75 const char *__restrict __version)
76 __THROW __nonnull ((2, 3));
77#endif
78
79/* When any of the above functions fails, call this function
80 to return a string describing the error. Each call resets
81 the error string so that a following call returns null. */
82extern char *dlerror (void) __THROW;
83
84
85#ifdef __USE_GNU
86/* Structure containing information about object searched using
87 `dladdr'. */
88typedef struct
89{
90 const char *dli_fname; /* File name of defining object. */
91 void *dli_fbase; /* Load address of that object. */
92 const char *dli_sname; /* Name of nearest symbol. */
93 void *dli_saddr; /* Exact value of nearest symbol. */
94} Dl_info;
95
96/* Fill in *INFO with the following information about ADDRESS.
97 Returns 0 iff no shared object's segments contain that address. */
98extern int dladdr (const void *__address, Dl_info *__info)
99 __THROW __nonnull ((2));
100
101/* Same as `dladdr', but additionally sets *EXTRA_INFO according to FLAGS. */
102extern int dladdr1 (const void *__address, Dl_info *__info,
103 void **__extra_info, int __flags) __THROW __nonnull ((2));
104
105/* These are the possible values for the FLAGS argument to `dladdr1'.
106 This indicates what extra information is stored at *EXTRA_INFO.
107 It may also be zero, in which case the EXTRA_INFO argument is not used. */
108enum
109 {
110 /* Matching symbol table entry (const ElfNN_Sym *). */
111 RTLD_DL_SYMENT = 1,
112
113 /* The object containing the address (struct link_map *). */
114 RTLD_DL_LINKMAP = 2
115 };
116
117
118/* Get information about the shared object HANDLE refers to.
119 REQUEST is from among the values below, and determines the use of ARG.
120
121 On success, returns zero. On failure, returns -1 and records an error
122 message to be fetched with `dlerror'. */
123extern int dlinfo (void *__restrict __handle,
124 int __request, void *__restrict __arg)
125 __THROW __nonnull ((1, 3));
126
127/* These are the possible values for the REQUEST argument to `dlinfo'. */
128enum
129 {
130 /* Treat ARG as `lmid_t *'; store namespace ID for HANDLE there. */
131 RTLD_DI_LMID = 1,
132
133 /* Treat ARG as `struct link_map **';
134 store the `struct link_map *' for HANDLE there. */
135 RTLD_DI_LINKMAP = 2,
136
137 RTLD_DI_CONFIGADDR = 3, /* Unsupported, defined by Solaris. */
138
139 /* Treat ARG as `Dl_serinfo *' (see below), and fill in to describe the
140 directories that will be searched for dependencies of this object.
141 RTLD_DI_SERINFOSIZE fills in just the `dls_cnt' and `dls_size'
142 entries to indicate the size of the buffer that must be passed to
143 RTLD_DI_SERINFO to fill in the full information. */
144 RTLD_DI_SERINFO = 4,
145 RTLD_DI_SERINFOSIZE = 5,
146
147 /* Treat ARG as `char *', and store there the directory name used to
148 expand $ORIGIN in this shared object's dependency file names. */
149 RTLD_DI_ORIGIN = 6,
150
151 RTLD_DI_PROFILENAME = 7, /* Unsupported, defined by Solaris. */
152 RTLD_DI_PROFILEOUT = 8, /* Unsupported, defined by Solaris. */
153
154 /* Treat ARG as `size_t *', and store there the TLS module ID
155 of this object's PT_TLS segment, as used in TLS relocations;
156 store zero if this object does not define a PT_TLS segment. */
157 RTLD_DI_TLS_MODID = 9,
158
159 /* Treat ARG as `void **', and store there a pointer to the calling
160 thread's TLS block corresponding to this object's PT_TLS segment.
161 Store a null pointer if this object does not define a PT_TLS
162 segment, or if the calling thread has not allocated a block for it. */
163 RTLD_DI_TLS_DATA = 10,
164
165 RTLD_DI_MAX = 10
166 };
167
168
169/* This is the type of elements in `Dl_serinfo', below.
170 The `dls_name' member points to space in the buffer passed to `dlinfo'. */
171typedef struct
172{
173 char *dls_name; /* Name of library search path directory. */
174 unsigned int dls_flags; /* Indicates where this directory came from. */
175} Dl_serpath;
176
177/* This is the structure that must be passed (by reference) to `dlinfo' for
178 the RTLD_DI_SERINFO and RTLD_DI_SERINFOSIZE requests. */
179typedef struct
180{
181 size_t dls_size; /* Size in bytes of the whole buffer. */
182 unsigned int dls_cnt; /* Number of elements in `dls_serpath'. */
183 Dl_serpath dls_serpath[1]; /* Actually longer, dls_cnt elements. */
184} Dl_serinfo;
185#endif /* __USE_GNU */
186
187
188__END_DECLS
189
190#endif /* dlfcn.h */
191