1 /* $OpenBSD: dso.h,v 1.13 2022/07/12 14:42:49 kn Exp $ */
2 /* Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL
3  * project 2000.
4  */
5 /* ====================================================================
6  * Copyright (c) 2000 The OpenSSL Project.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in
17  *    the documentation and/or other materials provided with the
18  *    distribution.
19  *
20  * 3. All advertising materials mentioning features or use of this
21  *    software must display the following acknowledgment:
22  *    "This product includes software developed by the OpenSSL Project
23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
24  *
25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26  *    endorse or promote products derived from this software without
27  *    prior written permission. For written permission, please contact
28  *    licensing@OpenSSL.org.
29  *
30  * 5. Products derived from this software may not be called "OpenSSL"
31  *    nor may "OpenSSL" appear in their names without prior written
32  *    permission of the OpenSSL Project.
33  *
34  * 6. Redistributions of any form whatsoever must retain the following
35  *    acknowledgment:
36  *    "This product includes software developed by the OpenSSL Project
37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
38  *
39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50  * OF THE POSSIBILITY OF SUCH DAMAGE.
51  * ====================================================================
52  *
53  * This product includes cryptographic software written by Eric Young
54  * (eay@cryptsoft.com).  This product includes software written by Tim
55  * Hudson (tjh@cryptsoft.com).
56  *
57  */
58 
59 #ifndef HEADER_DSO_H
60 #define HEADER_DSO_H
61 
62 #include <openssl/crypto.h>
63 
64 #ifdef __cplusplus
65 extern "C" {
66 #endif
67 
68 /* These values are used as commands to DSO_ctrl() */
69 #define DSO_CTRL_GET_FLAGS	1
70 #define DSO_CTRL_SET_FLAGS	2
71 #define DSO_CTRL_OR_FLAGS	3
72 
73 /* By default, DSO_load() will translate the provided filename into a form
74  * typical for the platform (more specifically the DSO_METHOD) using the
75  * dso_name_converter function of the method. Eg. win32 will transform "blah"
76  * into "blah.dll", and dlfcn will transform it into "libblah.so". The
77  * behaviour can be overridden by setting the name_converter callback in the DSO
78  * object (using DSO_set_name_converter()). This callback could even utilise
79  * the DSO_METHOD's converter too if it only wants to override behaviour for
80  * one or two possible DSO methods. However, the following flag can be set in a
81  * DSO to prevent *any* native name-translation at all - eg. if the caller has
82  * prompted the user for a path to a driver library so the filename should be
83  * interpreted as-is. */
84 #define DSO_FLAG_NO_NAME_TRANSLATION		0x01
85 /* An extra flag to give if only the extension should be added as
86  * translation.  This is obviously only of importance on Unix and
87  * other operating systems where the translation also may prefix
88  * the name with something, like 'lib', and ignored everywhere else.
89  * This flag is also ignored if DSO_FLAG_NO_NAME_TRANSLATION is used
90  * at the same time. */
91 #define DSO_FLAG_NAME_TRANSLATION_EXT_ONLY	0x02
92 
93 /* The following flag controls the translation of symbol names to upper
94  * case.  This is currently only being implemented for OpenVMS.
95  */
96 #define DSO_FLAG_UPCASE_SYMBOL			0x10
97 
98 /* This flag loads the library with public symbols.
99  * Meaning: The exported symbols of this library are public
100  * to all libraries loaded after this library.
101  * At the moment only implemented in unix.
102  */
103 #define DSO_FLAG_GLOBAL_SYMBOLS			0x20
104 
105 
106 typedef void (*DSO_FUNC_TYPE)(void);
107 
108 typedef struct dso_st DSO;
109 
110 /* The function prototype used for method functions (or caller-provided
111  * callbacks) that transform filenames. They are passed a DSO structure pointer
112  * (or NULL if they are to be used independantly of a DSO object) and a
113  * filename to transform. They should either return NULL (if there is an error
114  * condition) or a newly allocated string containing the transformed form that
115  * the caller will need to free with free() when done. */
116 typedef char* (*DSO_NAME_CONVERTER_FUNC)(DSO *, const char *);
117 /* The function prototype used for method functions (or caller-provided
118  * callbacks) that merge two file specifications. They are passed a
119  * DSO structure pointer (or NULL if they are to be used independantly of
120  * a DSO object) and two file specifications to merge. They should
121  * either return NULL (if there is an error condition) or a newly allocated
122  * string containing the result of merging that the caller will need
123  * to free with free() when done.
124  * Here, merging means that bits and pieces are taken from each of the
125  * file specifications and added together in whatever fashion that is
126  * sensible for the DSO method in question.  The only rule that really
127  * applies is that if the two specification contain pieces of the same
128  * type, the copy from the first string takes priority.  One could see
129  * it as the first specification is the one given by the user and the
130  * second being a bunch of defaults to add on if they're missing in the
131  * first. */
132 typedef char* (*DSO_MERGER_FUNC)(DSO *, const char *, const char *);
133 
134 typedef struct dso_meth_st {
135 	const char *name;
136 	/* Loads a shared library, NB: new DSO_METHODs must ensure that a
137 	 * successful load populates the loaded_filename field, and likewise a
138 	 * successful unload frees and NULLs it out. */
139 	int (*dso_load)(DSO *dso);
140 	/* Unloads a shared library */
141 	int (*dso_unload)(DSO *dso);
142 	/* Binds a variable */
143 	void *(*dso_bind_var)(DSO *dso, const char *symname);
144 	/* Binds a function - assumes a return type of DSO_FUNC_TYPE.
145 	 * This should be cast to the real function prototype by the
146 	 * caller. Platforms that don't have compatible representations
147 	 * for different prototypes (this is possible within ANSI C)
148 	 * are highly unlikely to have shared libraries at all, let
149 	 * alone a DSO_METHOD implemented for them. */
150 	DSO_FUNC_TYPE (*dso_bind_func)(DSO *dso, const char *symname);
151 
152 	/* The generic (yuck) "ctrl()" function. NB: Negative return
153 	 * values (rather than zero) indicate errors. */
154 	long (*dso_ctrl)(DSO *dso, int cmd, long larg, void *parg);
155 	/* The default DSO_METHOD-specific function for converting filenames to
156 	 * a canonical native form. */
157 	DSO_NAME_CONVERTER_FUNC dso_name_converter;
158 	/* The default DSO_METHOD-specific function for converting filenames to
159 	 * a canonical native form. */
160 	DSO_MERGER_FUNC dso_merger;
161 
162 	/* [De]Initialisation handlers. */
163 	int (*init)(DSO *dso);
164 	int (*finish)(DSO *dso);
165 
166 	/* Return pathname of the module containing location */
167 	int (*pathbyaddr)(void *addr, char *path, int sz);
168 	/* Perform global symbol lookup, i.e. among *all* modules */
169 	void *(*globallookup)(const char *symname);
170 } DSO_METHOD;
171 
172 /**********************************************************************/
173 /* The low-level handle type used to refer to a loaded shared library */
174 
175 struct dso_st {
176 	DSO_METHOD *meth;
177 	/* Standard dlopen uses a (void *). Win32 uses a HANDLE. VMS
178 	 * doesn't use anything but will need to cache the filename
179 	 * for use in the dso_bind handler. All in all, let each
180 	 * method control its own destiny. "Handles" and such go in
181 	 * a STACK. */
182 	STACK_OF(void) *meth_data;
183 	int references;
184 	int flags;
185 	/* For use by applications etc ... use this for your bits'n'pieces,
186 	 * don't touch meth_data! */
187 	CRYPTO_EX_DATA ex_data;
188 	/* If this callback function pointer is set to non-NULL, then it will
189 	 * be used in DSO_load() in place of meth->dso_name_converter. NB: This
190 	 * should normally set using DSO_set_name_converter(). */
191 	DSO_NAME_CONVERTER_FUNC name_converter;
192 	/* If this callback function pointer is set to non-NULL, then it will
193 	 * be used in DSO_load() in place of meth->dso_merger. NB: This
194 	 * should normally set using DSO_set_merger(). */
195 	DSO_MERGER_FUNC merger;
196 	/* This is populated with (a copy of) the platform-independant
197 	 * filename used for this DSO. */
198 	char *filename;
199 	/* This is populated with (a copy of) the translated filename by which
200 	 * the DSO was actually loaded. It is NULL iff the DSO is not currently
201 	 * loaded. NB: This is here because the filename translation process
202 	 * may involve a callback being invoked more than once not only to
203 	 * convert to a platform-specific form, but also to try different
204 	 * filenames in the process of trying to perform a load. As such, this
205 	 * variable can be used to indicate (a) whether this DSO structure
206 	 * corresponds to a loaded library or not, and (b) the filename with
207 	 * which it was actually loaded. */
208 	char *loaded_filename;
209 };
210 
211 
212 DSO *	DSO_new(void);
213 DSO *	DSO_new_method(DSO_METHOD *method);
214 int	DSO_free(DSO *dso);
215 int	DSO_flags(DSO *dso);
216 int	DSO_up_ref(DSO *dso);
217 long	DSO_ctrl(DSO *dso, int cmd, long larg, void *parg);
218 
219 /* This function sets the DSO's name_converter callback. If it is non-NULL,
220  * then it will be used instead of the associated DSO_METHOD's function. If
221  * oldcb is non-NULL then it is set to the function pointer value being
222  * replaced. Return value is non-zero for success. */
223 int	DSO_set_name_converter(DSO *dso, DSO_NAME_CONVERTER_FUNC cb,
224 	    DSO_NAME_CONVERTER_FUNC *oldcb);
225 /* These functions can be used to get/set the platform-independant filename
226  * used for a DSO. NB: set will fail if the DSO is already loaded. */
227 const char *DSO_get_filename(DSO *dso);
228 int	DSO_set_filename(DSO *dso, const char *filename);
229 /* This function will invoke the DSO's name_converter callback to translate a
230  * filename, or if the callback isn't set it will instead use the DSO_METHOD's
231  * converter. If "filename" is NULL, the "filename" in the DSO itself will be
232  * used. If the DSO_FLAG_NO_NAME_TRANSLATION flag is set, then the filename is
233  * simply duplicated. NB: This function is usually called from within a
234  * DSO_METHOD during the processing of a DSO_load() call, and is exposed so that
235  * caller-created DSO_METHODs can do the same thing. A non-NULL return value
236  * will need to be free()'d. */
237 char	*DSO_convert_filename(DSO *dso, const char *filename);
238 /* This function will invoke the DSO's merger callback to merge two file
239  * specifications, or if the callback isn't set it will instead use the
240  * DSO_METHOD's merger.  A non-NULL return value will need to be
241  * free()'d. */
242 char	*DSO_merge(DSO *dso, const char *filespec1, const char *filespec2);
243 /* If the DSO is currently loaded, this returns the filename that it was loaded
244  * under, otherwise it returns NULL. So it is also useful as a test as to
245  * whether the DSO is currently loaded. NB: This will not necessarily return
246  * the same value as DSO_convert_filename(dso, dso->filename), because the
247  * DSO_METHOD's load function may have tried a variety of filenames (with
248  * and/or without the aid of the converters) before settling on the one it
249  * actually loaded. */
250 const char *DSO_get_loaded_filename(DSO *dso);
251 
252 void	DSO_set_default_method(DSO_METHOD *meth);
253 DSO_METHOD *DSO_get_default_method(void);
254 DSO_METHOD *DSO_get_method(DSO *dso);
255 DSO_METHOD *DSO_set_method(DSO *dso, DSO_METHOD *meth);
256 
257 /* The all-singing all-dancing load function, you normally pass NULL
258  * for the first and third parameters. Use DSO_up and DSO_free for
259  * subsequent reference count handling. Any flags passed in will be set
260  * in the constructed DSO after its init() function but before the
261  * load operation. If 'dso' is non-NULL, 'flags' is ignored. */
262 DSO *DSO_load(DSO *dso, const char *filename, DSO_METHOD *meth, int flags);
263 
264 /* This function binds to a variable inside a shared library. */
265 void *DSO_bind_var(DSO *dso, const char *symname);
266 
267 /* This function binds to a function inside a shared library. */
268 DSO_FUNC_TYPE DSO_bind_func(DSO *dso, const char *symname);
269 
270 /* This method is the default, but will beg, borrow, or steal whatever
271  * method should be the default on any particular platform (including
272  * DSO_METH_null() if necessary). */
273 DSO_METHOD *DSO_METHOD_openssl(void);
274 
275 /* This method is defined for all platforms - if a platform has no
276  * DSO support then this will be the only method! */
277 DSO_METHOD *DSO_METHOD_null(void);
278 
279 /* If DSO_DLFCN is defined, the standard dlfcn.h-style functions
280  * (dlopen, dlclose, dlsym, etc) will be used and incorporated into
281  * this method. If not, this method will return NULL. */
282 DSO_METHOD *DSO_METHOD_dlfcn(void);
283 
284 /* This function writes null-terminated pathname of DSO module
285  * containing 'addr' into 'sz' large caller-provided 'path' and
286  * returns the number of characters [including trailing zero]
287  * written to it. If 'sz' is 0 or negative, 'path' is ignored and
288  * required amount of charachers [including trailing zero] to
289  * accommodate pathname is returned. If 'addr' is NULL, then
290  * pathname of cryptolib itself is returned. Negative or zero
291  * return value denotes error.
292  */
293 int DSO_pathbyaddr(void *addr, char *path, int sz);
294 
295 /* This function should be used with caution! It looks up symbols in
296  * *all* loaded modules and if module gets unloaded by somebody else
297  * attempt to dereference the pointer is doomed to have fatal
298  * consequences. Primary usage for this function is to probe *core*
299  * system functionality, e.g. check if getnameinfo(3) is available
300  * at run-time without bothering about OS-specific details such as
301  * libc.so.versioning or where does it actually reside: in libc
302  * itself or libsocket. */
303 void *DSO_global_lookup(const char *name);
304 
305 void ERR_load_DSO_strings(void);
306 
307 /* Error codes for the DSO functions. */
308 
309 /* Function codes. */
310 #define DSO_F_BEOS_BIND_FUNC				 144
311 #define DSO_F_BEOS_BIND_VAR				 145
312 #define DSO_F_BEOS_LOAD					 146
313 #define DSO_F_BEOS_NAME_CONVERTER			 147
314 #define DSO_F_BEOS_UNLOAD				 148
315 #define DSO_F_DLFCN_BIND_FUNC				 100
316 #define DSO_F_DLFCN_BIND_VAR				 101
317 #define DSO_F_DLFCN_LOAD				 102
318 #define DSO_F_DLFCN_MERGER				 130
319 #define DSO_F_DLFCN_NAME_CONVERTER			 123
320 #define DSO_F_DLFCN_UNLOAD				 103
321 #define DSO_F_DL_BIND_FUNC				 104
322 #define DSO_F_DL_BIND_VAR				 105
323 #define DSO_F_DL_LOAD					 106
324 #define DSO_F_DL_MERGER					 131
325 #define DSO_F_DL_NAME_CONVERTER				 124
326 #define DSO_F_DL_UNLOAD					 107
327 #define DSO_F_DSO_BIND_FUNC				 108
328 #define DSO_F_DSO_BIND_VAR				 109
329 #define DSO_F_DSO_CONVERT_FILENAME			 126
330 #define DSO_F_DSO_CTRL					 110
331 #define DSO_F_DSO_FREE					 111
332 #define DSO_F_DSO_GET_FILENAME				 127
333 #define DSO_F_DSO_GET_LOADED_FILENAME			 128
334 #define DSO_F_DSO_GLOBAL_LOOKUP				 139
335 #define DSO_F_DSO_LOAD					 112
336 #define DSO_F_DSO_MERGE					 132
337 #define DSO_F_DSO_NEW_METHOD				 113
338 #define DSO_F_DSO_PATHBYADDR				 140
339 #define DSO_F_DSO_SET_FILENAME				 129
340 #define DSO_F_DSO_SET_NAME_CONVERTER			 122
341 #define DSO_F_DSO_UP_REF				 114
342 #define DSO_F_GLOBAL_LOOKUP_FUNC			 138
343 #define DSO_F_PATHBYADDR				 137
344 #define DSO_F_VMS_BIND_SYM				 115
345 #define DSO_F_VMS_LOAD					 116
346 #define DSO_F_VMS_MERGER				 133
347 #define DSO_F_VMS_UNLOAD				 117
348 #define DSO_F_WIN32_BIND_FUNC				 118
349 #define DSO_F_WIN32_BIND_VAR				 119
350 #define DSO_F_WIN32_GLOBALLOOKUP			 142
351 #define DSO_F_WIN32_GLOBALLOOKUP_FUNC			 143
352 #define DSO_F_WIN32_JOINER				 135
353 #define DSO_F_WIN32_LOAD				 120
354 #define DSO_F_WIN32_MERGER				 134
355 #define DSO_F_WIN32_NAME_CONVERTER			 125
356 #define DSO_F_WIN32_PATHBYADDR				 141
357 #define DSO_F_WIN32_SPLITTER				 136
358 #define DSO_F_WIN32_UNLOAD				 121
359 
360 /* Reason codes. */
361 #define DSO_R_CTRL_FAILED				 100
362 #define DSO_R_DSO_ALREADY_LOADED			 110
363 #define DSO_R_EMPTY_FILE_STRUCTURE			 113
364 #define DSO_R_FAILURE					 114
365 #define DSO_R_FILENAME_TOO_BIG				 101
366 #define DSO_R_FINISH_FAILED				 102
367 #define DSO_R_INCORRECT_FILE_SYNTAX			 115
368 #define DSO_R_LOAD_FAILED				 103
369 #define DSO_R_NAME_TRANSLATION_FAILED			 109
370 #define DSO_R_NO_FILENAME				 111
371 #define DSO_R_NO_FILE_SPECIFICATION			 116
372 #define DSO_R_NULL_HANDLE				 104
373 #define DSO_R_SET_FILENAME_FAILED			 112
374 #define DSO_R_STACK_ERROR				 105
375 #define DSO_R_SYM_FAILURE				 106
376 #define DSO_R_UNLOAD_FAILED				 107
377 #define DSO_R_UNSUPPORTED				 108
378 
379 #ifdef  __cplusplus
380 }
381 #endif
382 #endif
383