2 * Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
13 # include <openssl/crypto.h>
14 # include "internal/dsoerr.h"
20 /* These values are used as commands to DSO_ctrl() */
21 # define DSO_CTRL_GET_FLAGS 1
22 # define DSO_CTRL_SET_FLAGS 2
23 # define DSO_CTRL_OR_FLAGS 3
26 * By default, DSO_load() will translate the provided filename into a form
27 * typical for the platform using the dso_name_converter function of the
28 * method. Eg. win32 will transform "blah" into "blah.dll", and dlfcn will
29 * transform it into "libblah.so". This callback could even utilise the
30 * DSO_METHOD's converter too if it only wants to override behaviour for
31 * one or two possible DSO methods. However, the following flag can be
32 * set in a DSO to prevent *any* native name-translation at all - eg. if
33 * the caller has prompted the user for a path to a driver library so the
34 * filename should be interpreted as-is.
36 # define DSO_FLAG_NO_NAME_TRANSLATION 0x01
38 * An extra flag to give if only the extension should be added as
39 * translation. This is obviously only of importance on Unix and other
40 * operating systems where the translation also may prefix the name with
41 * something, like 'lib', and ignored everywhere else. This flag is also
42 * ignored if DSO_FLAG_NO_NAME_TRANSLATION is used at the same time.
44 # define DSO_FLAG_NAME_TRANSLATION_EXT_ONLY 0x02
47 * Don't unload the DSO when we call DSO_free()
49 # define DSO_FLAG_NO_UNLOAD_ON_FREE 0x04
52 * This flag loads the library with public symbols. Meaning: The exported
53 * symbols of this library are public to all libraries loaded after this
54 * library. At the moment only implemented in unix.
56 # define DSO_FLAG_GLOBAL_SYMBOLS 0x20
58 typedef void (*DSO_FUNC_TYPE) (void);
60 typedef struct dso_st DSO;
61 typedef struct dso_meth_st DSO_METHOD;
64 * The function prototype used for method functions (or caller-provided
65 * callbacks) that transform filenames. They are passed a DSO structure
66 * pointer (or NULL if they are to be used independently of a DSO object) and
67 * a filename to transform. They should either return NULL (if there is an
68 * error condition) or a newly allocated string containing the transformed
69 * form that the caller will need to free with OPENSSL_free() when done.
71 typedef char *(*DSO_NAME_CONVERTER_FUNC)(DSO *, const char *);
73 * The function prototype used for method functions (or caller-provided
74 * callbacks) that merge two file specifications. They are passed a DSO
75 * structure pointer (or NULL if they are to be used independently of a DSO
76 * object) and two file specifications to merge. They should either return
77 * NULL (if there is an error condition) or a newly allocated string
78 * containing the result of merging that the caller will need to free with
79 * OPENSSL_free() when done. Here, merging means that bits and pieces are
80 * taken from each of the file specifications and added together in whatever
81 * fashion that is sensible for the DSO method in question. The only rule
82 * that really applies is that if the two specification contain pieces of the
83 * same type, the copy from the first string takes priority. One could see
84 * it as the first specification is the one given by the user and the second
85 * being a bunch of defaults to add on if they're missing in the first.
87 typedef char *(*DSO_MERGER_FUNC)(DSO *, const char *, const char *);
90 int DSO_free(DSO *dso);
91 int DSO_flags(DSO *dso);
92 int DSO_up_ref(DSO *dso);
93 long DSO_ctrl(DSO *dso, int cmd, long larg, void *parg);
96 * These functions can be used to get/set the platform-independent filename
97 * used for a DSO. NB: set will fail if the DSO is already loaded.
99 const char *DSO_get_filename(DSO *dso);
100 int DSO_set_filename(DSO *dso, const char *filename);
102 * This function will invoke the DSO's name_converter callback to translate a
103 * filename, or if the callback isn't set it will instead use the DSO_METHOD's
104 * converter. If "filename" is NULL, the "filename" in the DSO itself will be
105 * used. If the DSO_FLAG_NO_NAME_TRANSLATION flag is set, then the filename is
106 * simply duplicated. NB: This function is usually called from within a
107 * DSO_METHOD during the processing of a DSO_load() call, and is exposed so
108 * that caller-created DSO_METHODs can do the same thing. A non-NULL return
109 * value will need to be OPENSSL_free()'d.
111 char *DSO_convert_filename(DSO *dso, const char *filename);
113 * This function will invoke the DSO's merger callback to merge two file
114 * specifications, or if the callback isn't set it will instead use the
115 * DSO_METHOD's merger. A non-NULL return value will need to be
118 char *DSO_merge(DSO *dso, const char *filespec1, const char *filespec2);
121 * The all-singing all-dancing load function, you normally pass NULL for the
122 * first and third parameters. Use DSO_up_ref and DSO_free for subsequent
123 * reference count handling. Any flags passed in will be set in the
124 * constructed DSO after its init() function but before the load operation.
125 * If 'dso' is non-NULL, 'flags' is ignored.
127 DSO *DSO_load(DSO *dso, const char *filename, DSO_METHOD *meth, int flags);
129 /* This function binds to a function inside a shared library. */
130 DSO_FUNC_TYPE DSO_bind_func(DSO *dso, const char *symname);
133 * This method is the default, but will beg, borrow, or steal whatever method
134 * should be the default on any particular platform (including
135 * DSO_METH_null() if necessary).
137 DSO_METHOD *DSO_METHOD_openssl(void);
140 * This function writes null-terminated pathname of DSO module containing
141 * 'addr' into 'sz' large caller-provided 'path' and returns the number of
142 * characters [including trailing zero] written to it. If 'sz' is 0 or
143 * negative, 'path' is ignored and required amount of characters [including
144 * trailing zero] to accommodate pathname is returned. If 'addr' is NULL, then
145 * pathname of cryptolib itself is returned. Negative or zero return value
148 int DSO_pathbyaddr(void *addr, char *path, int sz);
151 * Like DSO_pathbyaddr() but instead returns a handle to the DSO for the symbol
154 DSO *DSO_dsobyaddr(void *addr, int flags);
157 * This function should be used with caution! It looks up symbols in *all*
158 * loaded modules and if module gets unloaded by somebody else attempt to
159 * dereference the pointer is doomed to have fatal consequences. Primary
160 * usage for this function is to probe *core* system functionality, e.g.
161 * check if getnameinfo(3) is available at run-time without bothering about
162 * OS-specific details such as libc.so.versioning or where does it actually
163 * reside: in libc itself or libsocket.
165 void *DSO_global_lookup(const char *name);
167 int ERR_load_DSO_strings(void);