1 | /* User functions for run-time dynamic loading. |
2 | Copyright (C) 1995-2019 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. */ |
44 | typedef 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. */ |
56 | extern 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'. */ |
60 | extern 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. */ |
64 | extern 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. */ |
69 | extern 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. */ |
73 | extern 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. */ |
82 | extern char *dlerror (void) __THROW; |
83 | |
84 | |
85 | #ifdef __USE_GNU |
86 | /* Structure containing information about object searched using |
87 | `dladdr'. */ |
88 | typedef 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. */ |
98 | extern 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. */ |
102 | extern int dladdr1 (const void *__address, Dl_info *__info, |
103 | void **, 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. */ |
108 | enum |
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'. */ |
123 | extern 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'. */ |
128 | enum |
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'. */ |
171 | typedef 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. */ |
179 | typedef 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 | |