xref: /freebsd/include/dlfcn.h (revision a0409676120c1e558d0ade943019934e0f15118d)
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  * $FreeBSD$
32  */
33 
34 #ifndef _DLFCN_H_
35 #define	_DLFCN_H_
36 
37 #include <sys/_types.h>
38 
39 /*
40  * Modes and flags for dlopen().
41  */
42 #define	RTLD_LAZY	1	/* Bind function calls lazily. */
43 #define	RTLD_NOW	2	/* Bind function calls immediately. */
44 #define	RTLD_MODEMASK	0x3
45 #define	RTLD_GLOBAL	0x100	/* Make symbols globally available. */
46 #define	RTLD_LOCAL	0	/* Opposite of RTLD_GLOBAL, and the default. */
47 #define	RTLD_TRACE	0x200	/* Trace loaded objects and exit. */
48 #define	RTLD_NODELETE	0x01000	/* Do not remove members. */
49 #define	RTLD_NOLOAD	0x02000	/* Do not load if not already loaded. */
50 #define	RTLD_DEEPBIND	0x04000	/* Put symbols from the dso ahead of
51 				   the global list */
52 
53 /*
54  * Request arguments for dlinfo().
55  */
56 #define	RTLD_DI_LINKMAP		2	/* Obtain link map. */
57 #define	RTLD_DI_SERINFO		4	/* Obtain search path info. */
58 #define	RTLD_DI_SERINFOSIZE	5	/*  ... query for required space. */
59 #define	RTLD_DI_ORIGIN		6	/* Obtain object origin */
60 #define	RTLD_DI_MAX		RTLD_DI_ORIGIN
61 
62 /*
63  * Special handle arguments for dlsym()/dlinfo().
64  */
65 #define	RTLD_NEXT	((void *) -1)	/* Search subsequent objects. */
66 #define	RTLD_DEFAULT	((void *) -2)	/* Use default search algorithm. */
67 #define	RTLD_SELF	((void *) -3)	/* Search the caller itself. */
68 
69 #if __BSD_VISIBLE
70 
71 #ifndef	_SIZE_T_DECLARED
72 typedef __size_t        size_t;
73 #define	_SIZE_T_DECLARED
74 #endif
75 
76 /*
77  * Structure filled in by dladdr().
78  */
79 typedef	struct dl_info {
80 	const char	*dli_fname;	/* Pathname of shared object. */
81 	void		*dli_fbase;	/* Base address of shared object. */
82 	const char	*dli_sname;	/* Name of nearest symbol. */
83 	void		*dli_saddr;	/* Address of nearest symbol. */
84 } Dl_info;
85 
86 /*-
87  * The actual type declared by this typedef is immaterial, provided that
88  * it is a function pointer.  Its purpose is to provide a return type for
89  * dlfunc() which can be cast to a function pointer type without depending
90  * on behavior undefined by the C standard, which might trigger a compiler
91  * diagnostic.  We intentionally declare a unique type signature to force
92  * a diagnostic should the application not cast the return value of dlfunc()
93  * appropriately.
94  */
95 struct __dlfunc_arg {
96 	int	__dlfunc_dummy;
97 };
98 
99 typedef	void (*dlfunc_t)(struct __dlfunc_arg);
100 
101 /*
102  * Structures, returned by the RTLD_DI_SERINFO dlinfo() request.
103  */
104 typedef struct dl_serpath {
105 	char *		dls_name;	/* single search path entry */
106 	unsigned int	dls_flags;	/* path information */
107 } Dl_serpath;
108 
109 typedef struct  dl_serinfo {
110         size_t		dls_size;       /* total buffer size */
111         unsigned int	dls_cnt;        /* number of path entries */
112         Dl_serpath	dls_serpath[1]; /* there may be more than one */
113 } Dl_serinfo;
114 
115 #endif /* __BSD_VISIBLE */
116 
117 __BEGIN_DECLS
118 /* XSI functions first. */
119 int	 dlclose(void *);
120 char	*dlerror(void);
121 void	*dlopen(const char *, int);
122 void	*dlsym(void * __restrict, const char * __restrict);
123 
124 #if __BSD_VISIBLE
125 void	*fdlopen(int, int);
126 int	 dladdr(const void * __restrict, Dl_info * __restrict);
127 dlfunc_t dlfunc(void * __restrict, const char * __restrict);
128 int	 dlinfo(void * __restrict, int, void * __restrict);
129 void	 dllockinit(void *_context,
130 	    void *(*_lock_create)(void *_context),
131 	    void (*_rlock_acquire)(void *_lock),
132 	    void (*_wlock_acquire)(void *_lock),
133 	    void (*_lock_release)(void *_lock),
134 	    void (*_lock_destroy)(void *_lock),
135 	    void (*_context_destroy)(void *_context));
136 void	*dlvsym(void * __restrict, const char * __restrict,
137 	    const char * __restrict);
138 #endif /* __BSD_VISIBLE */
139 __END_DECLS
140 
141 #endif /* !_DLFCN_H_ */
142