1/* dso.h -*- mode:C; c-file-style: "eay" -*- */
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,
44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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
65extern "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 overriden 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
106typedef void (*DSO_FUNC_TYPE)(void);
107
108typedef 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 OPENSSL_free() when done. */
116typedef 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 OPENSSL_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. */
132typedef char* (*DSO_MERGER_FUNC)(DSO *, const char *, const char *);
133
134typedef struct dso_meth_st
135	{
136	const char *name;
137	/* Loads a shared library, NB: new DSO_METHODs must ensure that a
138	 * successful load populates the loaded_filename field, and likewise a
139	 * successful unload OPENSSL_frees and NULLs it out. */
140	int (*dso_load)(DSO *dso);
141	/* Unloads a shared library */
142	int (*dso_unload)(DSO *dso);
143	/* Binds a variable */
144	void *(*dso_bind_var)(DSO *dso, const char *symname);
145	/* Binds a function - assumes a return type of DSO_FUNC_TYPE.
146	 * This should be cast to the real function prototype by the
147	 * caller. Platforms that don't have compatible representations
148	 * for different prototypes (this is possible within ANSI C)
149	 * are highly unlikely to have shared libraries at all, let
150	 * alone a DSO_METHOD implemented for them. */
151	DSO_FUNC_TYPE (*dso_bind_func)(DSO *dso, const char *symname);
152
153/* I don't think this would actually be used in any circumstances. */
154#if 0
155	/* Unbinds a variable */
156	int (*dso_unbind_var)(DSO *dso, char *symname, void *symptr);
157	/* Unbinds a function */
158	int (*dso_unbind_func)(DSO *dso, char *symname, DSO_FUNC_TYPE symptr);
159#endif
160	/* The generic (yuck) "ctrl()" function. NB: Negative return
161	 * values (rather than zero) indicate errors. */
162	long (*dso_ctrl)(DSO *dso, int cmd, long larg, void *parg);
163	/* The default DSO_METHOD-specific function for converting filenames to
164	 * a canonical native form. */
165	DSO_NAME_CONVERTER_FUNC dso_name_converter;
166	/* The default DSO_METHOD-specific function for converting filenames to
167	 * a canonical native form. */
168	DSO_MERGER_FUNC dso_merger;
169
170	/* [De]Initialisation handlers. */
171	int (*init)(DSO *dso);
172	int (*finish)(DSO *dso);
173
174	/* Return pathname of the module containing location */
175	int (*pathbyaddr)(void *addr,char *path,int sz);
176	/* Perform global symbol lookup, i.e. among *all* modules */
177	void *(*globallookup)(const char *symname);
178	} DSO_METHOD;
179
180/**********************************************************************/
181/* The low-level handle type used to refer to a loaded shared library */
182
183struct dso_st
184	{
185	DSO_METHOD *meth;
186	/* Standard dlopen uses a (void *). Win32 uses a HANDLE. VMS
187	 * doesn't use anything but will need to cache the filename
188	 * for use in the dso_bind handler. All in all, let each
189	 * method control its own destiny. "Handles" and such go in
190	 * a STACK. */
191	STACK_OF(void) *meth_data;
192	int references;
193	int flags;
194	/* For use by applications etc ... use this for your bits'n'pieces,
195	 * don't touch meth_data! */
196	CRYPTO_EX_DATA ex_data;
197	/* If this callback function pointer is set to non-NULL, then it will
198	 * be used in DSO_load() in place of meth->dso_name_converter. NB: This
199	 * should normally set using DSO_set_name_converter(). */
200	DSO_NAME_CONVERTER_FUNC name_converter;
201	/* If this callback function pointer is set to non-NULL, then it will
202	 * be used in DSO_load() in place of meth->dso_merger. NB: This
203	 * should normally set using DSO_set_merger(). */
204	DSO_MERGER_FUNC merger;
205	/* This is populated with (a copy of) the platform-independant
206	 * filename used for this DSO. */
207	char *filename;
208	/* This is populated with (a copy of) the translated filename by which
209	 * the DSO was actually loaded. It is NULL iff the DSO is not currently
210	 * loaded. NB: This is here because the filename translation process
211	 * may involve a callback being invoked more than once not only to
212	 * convert to a platform-specific form, but also to try different
213	 * filenames in the process of trying to perform a load. As such, this
214	 * variable can be used to indicate (a) whether this DSO structure
215	 * corresponds to a loaded library or not, and (b) the filename with
216	 * which it was actually loaded. */
217	char *loaded_filename;
218	};
219
220
221DSO *	DSO_new(void);
222DSO *	DSO_new_method(DSO_METHOD *method);
223int	DSO_free(DSO *dso);
224int	DSO_flags(DSO *dso);
225int	DSO_up_ref(DSO *dso);
226long	DSO_ctrl(DSO *dso, int cmd, long larg, void *parg);
227
228/* This function sets the DSO's name_converter callback. If it is non-NULL,
229 * then it will be used instead of the associated DSO_METHOD's function. If
230 * oldcb is non-NULL then it is set to the function pointer value being
231 * replaced. Return value is non-zero for success. */
232int	DSO_set_name_converter(DSO *dso, DSO_NAME_CONVERTER_FUNC cb,
233				DSO_NAME_CONVERTER_FUNC *oldcb);
234/* These functions can be used to get/set the platform-independant filename
235 * used for a DSO. NB: set will fail if the DSO is already loaded. */
236const char *DSO_get_filename(DSO *dso);
237int	DSO_set_filename(DSO *dso, const char *filename);
238/* This function will invoke the DSO's name_converter callback to translate a
239 * filename, or if the callback isn't set it will instead use the DSO_METHOD's
240 * converter. If "filename" is NULL, the "filename" in the DSO itself will be
241 * used. If the DSO_FLAG_NO_NAME_TRANSLATION flag is set, then the filename is
242 * simply duplicated. NB: This function is usually called from within a
243 * DSO_METHOD during the processing of a DSO_load() call, and is exposed so that
244 * caller-created DSO_METHODs can do the same thing. A non-NULL return value
245 * will need to be OPENSSL_free()'d. */
246char	*DSO_convert_filename(DSO *dso, const char *filename);
247/* This function will invoke the DSO's merger callback to merge two file
248 * specifications, or if the callback isn't set it will instead use the
249 * DSO_METHOD's merger.  A non-NULL return value will need to be
250 * OPENSSL_free()'d. */
251char	*DSO_merge(DSO *dso, const char *filespec1, const char *filespec2);
252/* If the DSO is currently loaded, this returns the filename that it was loaded
253 * under, otherwise it returns NULL. So it is also useful as a test as to
254 * whether the DSO is currently loaded. NB: This will not necessarily return
255 * the same value as DSO_convert_filename(dso, dso->filename), because the
256 * DSO_METHOD's load function may have tried a variety of filenames (with
257 * and/or without the aid of the converters) before settling on the one it
258 * actually loaded. */
259const char *DSO_get_loaded_filename(DSO *dso);
260
261void	DSO_set_default_method(DSO_METHOD *meth);
262DSO_METHOD *DSO_get_default_method(void);
263DSO_METHOD *DSO_get_method(DSO *dso);
264DSO_METHOD *DSO_set_method(DSO *dso, DSO_METHOD *meth);
265
266/* The all-singing all-dancing load function, you normally pass NULL
267 * for the first and third parameters. Use DSO_up and DSO_free for
268 * subsequent reference count handling. Any flags passed in will be set
269 * in the constructed DSO after its init() function but before the
270 * load operation. If 'dso' is non-NULL, 'flags' is ignored. */
271DSO *DSO_load(DSO *dso, const char *filename, DSO_METHOD *meth, int flags);
272
273/* This function binds to a variable inside a shared library. */
274void *DSO_bind_var(DSO *dso, const char *symname);
275
276/* This function binds to a function inside a shared library. */
277DSO_FUNC_TYPE DSO_bind_func(DSO *dso, const char *symname);
278
279/* This method is the default, but will beg, borrow, or steal whatever
280 * method should be the default on any particular platform (including
281 * DSO_METH_null() if necessary). */
282DSO_METHOD *DSO_METHOD_openssl(void);
283
284/* This method is defined for all platforms - if a platform has no
285 * DSO support then this will be the only method! */
286DSO_METHOD *DSO_METHOD_null(void);
287
288/* If DSO_DLFCN is defined, the standard dlfcn.h-style functions
289 * (dlopen, dlclose, dlsym, etc) will be used and incorporated into
290 * this method. If not, this method will return NULL. */
291DSO_METHOD *DSO_METHOD_dlfcn(void);
292
293/* If DSO_DL is defined, the standard dl.h-style functions (shl_load,
294 * shl_unload, shl_findsym, etc) will be used and incorporated into
295 * this method. If not, this method will return NULL. */
296DSO_METHOD *DSO_METHOD_dl(void);
297
298/* If WIN32 is defined, use DLLs. If not, return NULL. */
299DSO_METHOD *DSO_METHOD_win32(void);
300
301/* If VMS is defined, use shared images. If not, return NULL. */
302DSO_METHOD *DSO_METHOD_vms(void);
303
304/* This function writes null-terminated pathname of DSO module
305 * containing 'addr' into 'sz' large caller-provided 'path' and
306 * returns the number of characters [including trailing zero]
307 * written to it. If 'sz' is 0 or negative, 'path' is ignored and
308 * required amount of charachers [including trailing zero] to
309 * accomodate pathname is returned. If 'addr' is NULL, then
310 * pathname of cryptolib itself is returned. Negative or zero
311 * return value denotes error.
312 */
313int DSO_pathbyaddr(void *addr,char *path,int sz);
314
315/* This function should be used with caution! It looks up symbols in
316 * *all* loaded modules and if module gets unloaded by somebody else
317 * attempt to dereference the pointer is doomed to have fatal
318 * consequences. Primary usage for this function is to probe *core*
319 * system functionality, e.g. check if getnameinfo(3) is available
320 * at run-time without bothering about OS-specific details such as
321 * libc.so.versioning or where does it actually reside: in libc
322 * itself or libsocket. */
323void *DSO_global_lookup(const char *name);
324
325/* If BeOS is defined, use shared images. If not, return NULL. */
326DSO_METHOD *DSO_METHOD_beos(void);
327
328/* BEGIN ERROR CODES */
329/* The following lines are auto generated by the script mkerr.pl. Any changes
330 * made after this point may be overwritten when the script is next run.
331 */
332void ERR_load_DSO_strings(void);
333
334/* Error codes for the DSO functions. */
335
336/* Function codes. */
337#define DSO_F_BEOS_BIND_FUNC				 144
338#define DSO_F_BEOS_BIND_VAR				 145
339#define DSO_F_BEOS_LOAD					 146
340#define DSO_F_BEOS_NAME_CONVERTER			 147
341#define DSO_F_BEOS_UNLOAD				 148
342#define DSO_F_DLFCN_BIND_FUNC				 100
343#define DSO_F_DLFCN_BIND_VAR				 101
344#define DSO_F_DLFCN_LOAD				 102
345#define DSO_F_DLFCN_MERGER				 130
346#define DSO_F_DLFCN_NAME_CONVERTER			 123
347#define DSO_F_DLFCN_UNLOAD				 103
348#define DSO_F_DL_BIND_FUNC				 104
349#define DSO_F_DL_BIND_VAR				 105
350#define DSO_F_DL_LOAD					 106
351#define DSO_F_DL_MERGER					 131
352#define DSO_F_DL_NAME_CONVERTER				 124
353#define DSO_F_DL_UNLOAD					 107
354#define DSO_F_DSO_BIND_FUNC				 108
355#define DSO_F_DSO_BIND_VAR				 109
356#define DSO_F_DSO_CONVERT_FILENAME			 126
357#define DSO_F_DSO_CTRL					 110
358#define DSO_F_DSO_FREE					 111
359#define DSO_F_DSO_GET_FILENAME				 127
360#define DSO_F_DSO_GET_LOADED_FILENAME			 128
361#define DSO_F_DSO_GLOBAL_LOOKUP				 139
362#define DSO_F_DSO_LOAD					 112
363#define DSO_F_DSO_MERGE					 132
364#define DSO_F_DSO_NEW_METHOD				 113
365#define DSO_F_DSO_PATHBYADDR				 140
366#define DSO_F_DSO_SET_FILENAME				 129
367#define DSO_F_DSO_SET_NAME_CONVERTER			 122
368#define DSO_F_DSO_UP_REF				 114
369#define DSO_F_GLOBAL_LOOKUP_FUNC			 138
370#define DSO_F_PATHBYADDR				 137
371#define DSO_F_VMS_BIND_SYM				 115
372#define DSO_F_VMS_LOAD					 116
373#define DSO_F_VMS_MERGER				 133
374#define DSO_F_VMS_UNLOAD				 117
375#define DSO_F_WIN32_BIND_FUNC				 118
376#define DSO_F_WIN32_BIND_VAR				 119
377#define DSO_F_WIN32_GLOBALLOOKUP			 142
378#define DSO_F_WIN32_GLOBALLOOKUP_FUNC			 143
379#define DSO_F_WIN32_JOINER				 135
380#define DSO_F_WIN32_LOAD				 120
381#define DSO_F_WIN32_MERGER				 134
382#define DSO_F_WIN32_NAME_CONVERTER			 125
383#define DSO_F_WIN32_PATHBYADDR				 141
384#define DSO_F_WIN32_SPLITTER				 136
385#define DSO_F_WIN32_UNLOAD				 121
386
387/* Reason codes. */
388#define DSO_R_CTRL_FAILED				 100
389#define DSO_R_DSO_ALREADY_LOADED			 110
390#define DSO_R_EMPTY_FILE_STRUCTURE			 113
391#define DSO_R_FAILURE					 114
392#define DSO_R_FILENAME_TOO_BIG				 101
393#define DSO_R_FINISH_FAILED				 102
394#define DSO_R_INCORRECT_FILE_SYNTAX			 115
395#define DSO_R_LOAD_FAILED				 103
396#define DSO_R_NAME_TRANSLATION_FAILED			 109
397#define DSO_R_NO_FILENAME				 111
398#define DSO_R_NO_FILE_SPECIFICATION			 116
399#define DSO_R_NULL_HANDLE				 104
400#define DSO_R_SET_FILENAME_FAILED			 112
401#define DSO_R_STACK_ERROR				 105
402#define DSO_R_SYM_FAILURE				 106
403#define DSO_R_UNLOAD_FAILED				 107
404#define DSO_R_UNSUPPORTED				 108
405
406#ifdef  __cplusplus
407}
408#endif
409#endif
410