xref: /freebsd/include/dlfcn.h (revision b01e971fd39d10273a387788019457792873e81c)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef _DLFCN_H_
33 #define	_DLFCN_H_
34 
35 #include <sys/cdefs.h>
36 #include <sys/_types.h>
37 
38 /*
39  * Modes and flags for dlopen().
40  */
41 #define	RTLD_LAZY	1	/* Bind function calls lazily. */
42 #define	RTLD_NOW	2	/* Bind function calls immediately. */
43 #define	RTLD_MODEMASK	0x3
44 #define	RTLD_GLOBAL	0x100	/* Make symbols globally available. */
45 #define	RTLD_LOCAL	0	/* Opposite of RTLD_GLOBAL, and the default. */
46 #define	RTLD_TRACE	0x200	/* Trace loaded objects and exit. */
47 #define	RTLD_NODELETE	0x01000	/* Do not remove members. */
48 #define	RTLD_NOLOAD	0x02000	/* Do not load if not already loaded. */
49 #define	RTLD_DEEPBIND	0x04000	/* Put symbols from the dso ahead of
50 				   the global list */
51 
52 /*
53  * Request arguments for dlinfo().
54  */
55 #define	RTLD_DI_LINKMAP		2	/* Obtain link map. */
56 #define	RTLD_DI_SERINFO		4	/* Obtain search path info. */
57 #define	RTLD_DI_SERINFOSIZE	5	/*  ... query for required space. */
58 #define	RTLD_DI_ORIGIN		6	/* Obtain object origin */
59 #define	RTLD_DI_MAX		RTLD_DI_ORIGIN
60 
61 /*
62  * Special handle arguments for dlsym()/dlinfo().
63  */
64 #define	RTLD_NEXT	((void *) -1)	/* Search subsequent objects. */
65 #define	RTLD_DEFAULT	((void *) -2)	/* Use default search algorithm. */
66 #define	RTLD_SELF	((void *) -3)	/* Search the caller itself. */
67 
68 #if __BSD_VISIBLE
69 
70 #ifndef	_SIZE_T_DECLARED
71 typedef __size_t        size_t;
72 #define	_SIZE_T_DECLARED
73 #endif
74 
75 /*
76  * Structure filled in by dladdr().
77  */
78 typedef	struct dl_info {
79 	const char	*dli_fname;	/* Pathname of shared object. */
80 	void		*dli_fbase;	/* Base address of shared object. */
81 	const char	*dli_sname;	/* Name of nearest symbol. */
82 	void		*dli_saddr;	/* Address of nearest symbol. */
83 } Dl_info;
84 
85 /*-
86  * The actual type declared by this typedef is immaterial, provided that
87  * it is a function pointer.  Its purpose is to provide a return type for
88  * dlfunc() which can be cast to a function pointer type without depending
89  * on behavior undefined by the C standard, which might trigger a compiler
90  * diagnostic.  We intentionally declare a unique type signature to force
91  * a diagnostic should the application not cast the return value of dlfunc()
92  * appropriately.
93  */
94 struct __dlfunc_arg {
95 	int	__dlfunc_dummy;
96 };
97 
98 typedef	void (*dlfunc_t)(struct __dlfunc_arg);
99 
100 /*
101  * Structures, returned by the RTLD_DI_SERINFO dlinfo() request.
102  */
103 typedef struct dl_serpath {
104 	char *		dls_name;	/* single search path entry */
105 	unsigned int	dls_flags;	/* path information */
106 } Dl_serpath;
107 
108 typedef struct  dl_serinfo {
109         size_t		dls_size;       /* total buffer size */
110         unsigned int	dls_cnt;        /* number of path entries */
111         Dl_serpath	dls_serpath[1]; /* there may be more than one */
112 } Dl_serinfo;
113 
114 #endif /* __BSD_VISIBLE */
115 
116 __BEGIN_DECLS
117 /* XSI functions first. */
118 int	 dlclose(void *);
119 char	*dlerror(void);
120 void	*dlopen(const char *, int);
121 void	*dlsym(void * __restrict, const char * __restrict);
122 
123 #if __BSD_VISIBLE
124 void	*fdlopen(int, int);
125 int	 dladdr(const void * __restrict, Dl_info * __restrict);
126 dlfunc_t dlfunc(void * __restrict, const char * __restrict);
127 int	 dlinfo(void * __restrict, int, void * __restrict);
128 void	 dllockinit(void *_context,
129 	    void *(*_lock_create)(void *_context),
130 	    void (*_rlock_acquire)(void *_lock),
131 	    void (*_wlock_acquire)(void *_lock),
132 	    void (*_lock_release)(void *_lock),
133 	    void (*_lock_destroy)(void *_lock),
134 	    void (*_context_destroy)(void *_context));
135 void	*dlvsym(void * __restrict, const char * __restrict,
136 	    const char * __restrict);
137 #endif /* __BSD_VISIBLE */
138 __END_DECLS
139 
140 #endif /* !_DLFCN_H_ */
141