dso.h revision 296465 
1/* dso.h -*- mode:C; c-file-style: "eay" -*- */
2/*
3 * Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL project
4 * 2000.
5 */
6/* ====================================================================
7 * Copyright (c) 2000 The OpenSSL Project.  All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 *
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in
18 *    the documentation and/or other materials provided with the
19 *    distribution.
20 *
21 * 3. All advertising materials mentioning features or use of this
22 *    software must display the following acknowledgment:
23 *    "This product includes software developed by the OpenSSL Project
24 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
25 *
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 *    endorse or promote products derived from this software without
28 *    prior written permission. For written permission, please contact
29 *    licensing@OpenSSL.org.
30 *
31 * 5. Products derived from this software may not be called "OpenSSL"
32 *    nor may "OpenSSL" appear in their names without prior written
33 *    permission of the OpenSSL Project.
34 *
35 * 6. Redistributions of any form whatsoever must retain the following
36 *    acknowledgment:
37 *    "This product includes software developed by the OpenSSL Project
38 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
53 *
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com).  This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
57 *
58 */
59
60#ifndef HEADER_DSO_H
61# define HEADER_DSO_H
62
63# include <openssl/crypto.h>
64
65#ifdef __cplusplus
66extern "C" {
67#endif
68
69/* These values are used as commands to DSO_ctrl() */
70# define DSO_CTRL_GET_FLAGS      1
71# define DSO_CTRL_SET_FLAGS      2
72# define DSO_CTRL_OR_FLAGS       3
73
74/*
75 * By default, DSO_load() will translate the provided filename into a form
76 * typical for the platform (more specifically the DSO_METHOD) using the
77 * dso_name_converter function of the method. Eg. win32 will transform "blah"
78 * into "blah.dll", and dlfcn will transform it into "libblah.so". The
79 * behaviour can be overriden by setting the name_converter callback in the
80 * DSO object (using DSO_set_name_converter()). This callback could even
81 * utilise the DSO_METHOD's converter too if it only wants to override
82 * behaviour for one or two possible DSO methods. However, the following flag
83 * can be set in a DSO to prevent *any* native name-translation at all - eg.
84 * if the caller has prompted the user for a path to a driver library so the
85 * filename should be interpreted as-is.
86 */
87# define DSO_FLAG_NO_NAME_TRANSLATION            0x01
88/*
89 * An extra flag to give if only the extension should be added as
90 * translation.  This is obviously only of importance on Unix and other
91 * operating systems where the translation also may prefix the name with
92 * something, like 'lib', and ignored everywhere else. This flag is also
93 * ignored if DSO_FLAG_NO_NAME_TRANSLATION is used at the same time.
94 */
95# define DSO_FLAG_NAME_TRANSLATION_EXT_ONLY      0x02
96
97/*
98 * The following flag controls the translation of symbol names to upper case.
99 * This is currently only being implemented for OpenVMS.
100 */
101# define DSO_FLAG_UPCASE_SYMBOL                  0x10
102
103/*
104 * This flag loads the library with public symbols. Meaning: The exported
105 * symbols of this library are public to all libraries loaded after this
106 * library. At the moment only implemented in unix.
107 */
108# define DSO_FLAG_GLOBAL_SYMBOLS                 0x20
109
110typedef void (*DSO_FUNC_TYPE) (void);
111
112typedef struct dso_st DSO;
113
114/*
115 * The function prototype used for method functions (or caller-provided
116 * callbacks) that transform filenames. They are passed a DSO structure
117 * pointer (or NULL if they are to be used independantly of a DSO object) and
118 * a filename to transform. They should either return NULL (if there is an
119 * error condition) or a newly allocated string containing the transformed
120 * form that the caller will need to free with OPENSSL_free() when done.
121 */
122typedef char *(*DSO_NAME_CONVERTER_FUNC)(DSO *, const char *);
123/*
124 * The function prototype used for method functions (or caller-provided
125 * callbacks) that merge two file specifications. They are passed a DSO
126 * structure pointer (or NULL if they are to be used independantly of a DSO
127 * object) and two file specifications to merge. They should either return
128 * NULL (if there is an error condition) or a newly allocated string
129 * containing the result of merging that the caller will need to free with
130 * OPENSSL_free() when done. Here, merging means that bits and pieces are
131 * taken from each of the file specifications and added together in whatever
132 * fashion that is sensible for the DSO method in question.  The only rule
133 * that really applies is that if the two specification contain pieces of the
134 * same type, the copy from the first string takes priority.  One could see
135 * it as the first specification is the one given by the user and the second
136 * being a bunch of defaults to add on if they're missing in the first.
137 */
138typedef char *(*DSO_MERGER_FUNC)(DSO *, const char *, const char *);
139
140typedef struct dso_meth_st {
141    const char *name;
142    /*
143     * Loads a shared library, NB: new DSO_METHODs must ensure that a
144     * successful load populates the loaded_filename field, and likewise a
145     * successful unload OPENSSL_frees and NULLs it out.
146     */
147    int (*dso_load) (DSO *dso);
148    /* Unloads a shared library */
149    int (*dso_unload) (DSO *dso);
150    /* Binds a variable */
151    void *(*dso_bind_var) (DSO *dso, const char *symname);
152    /*
153     * Binds a function - assumes a return type of DSO_FUNC_TYPE. This should
154     * be cast to the real function prototype by the caller. Platforms that
155     * don't have compatible representations for different prototypes (this
156     * is possible within ANSI C) are highly unlikely to have shared
157     * libraries at all, let alone a DSO_METHOD implemented for them.
158     */
159    DSO_FUNC_TYPE (*dso_bind_func) (DSO *dso, const char *symname);
160/* I don't think this would actually be used in any circumstances. */
161# if 0
162    /* Unbinds a variable */
163    int (*dso_unbind_var) (DSO *dso, char *symname, void *symptr);
164    /* Unbinds a function */
165    int (*dso_unbind_func) (DSO *dso, char *symname, DSO_FUNC_TYPE symptr);
166# endif
167    /*
168     * The generic (yuck) "ctrl()" function. NB: Negative return values
169     * (rather than zero) indicate errors.
170     */
171    long (*dso_ctrl) (DSO *dso, int cmd, long larg, void *parg);
172    /*
173     * The default DSO_METHOD-specific function for converting filenames to a
174     * canonical native form.
175     */
176    DSO_NAME_CONVERTER_FUNC dso_name_converter;
177    /*
178     * The default DSO_METHOD-specific function for converting filenames to a
179     * canonical native form.
180     */
181    DSO_MERGER_FUNC dso_merger;
182    /* [De]Initialisation handlers. */
183    int (*init) (DSO *dso);
184    int (*finish) (DSO *dso);
185} DSO_METHOD;
186
187/**********************************************************************/
188/* The low-level handle type used to refer to a loaded shared library */
189
190struct dso_st {
191    DSO_METHOD *meth;
192    /*
193     * Standard dlopen uses a (void *). Win32 uses a HANDLE. VMS doesn't use
194     * anything but will need to cache the filename for use in the dso_bind
195     * handler. All in all, let each method control its own destiny.
196     * "Handles" and such go in a STACK.
197     */
198    STACK *meth_data;
199    int references;
200    int flags;
201    /*
202     * For use by applications etc ... use this for your bits'n'pieces, don't
203     * touch meth_data!
204     */
205    CRYPTO_EX_DATA ex_data;
206    /*
207     * If this callback function pointer is set to non-NULL, then it will be
208     * used in DSO_load() in place of meth->dso_name_converter. NB: This
209     * should normally set using DSO_set_name_converter().
210     */
211    DSO_NAME_CONVERTER_FUNC name_converter;
212    /*
213     * If this callback function pointer is set to non-NULL, then it will be
214     * used in DSO_load() in place of meth->dso_merger. NB: This should
215     * normally set using DSO_set_merger().
216     */
217    DSO_MERGER_FUNC merger;
218    /*
219     * This is populated with (a copy of) the platform-independant filename
220     * used for this DSO.
221     */
222    char *filename;
223    /*
224     * This is populated with (a copy of) the translated filename by which
225     * the DSO was actually loaded. It is NULL iff the DSO is not currently
226     * loaded. NB: This is here because the filename translation process may
227     * involve a callback being invoked more than once not only to convert to
228     * a platform-specific form, but also to try different filenames in the
229     * process of trying to perform a load. As such, this variable can be
230     * used to indicate (a) whether this DSO structure corresponds to a
231     * loaded library or not, and (b) the filename with which it was actually
232     * loaded.
233     */
234    char *loaded_filename;
235};
236
237DSO *DSO_new(void);
238DSO *DSO_new_method(DSO_METHOD *method);
239int DSO_free(DSO *dso);
240int DSO_flags(DSO *dso);
241int DSO_up_ref(DSO *dso);
242long DSO_ctrl(DSO *dso, int cmd, long larg, void *parg);
243
244/*
245 * This function sets the DSO's name_converter callback. If it is non-NULL,
246 * then it will be used instead of the associated DSO_METHOD's function. If
247 * oldcb is non-NULL then it is set to the function pointer value being
248 * replaced. Return value is non-zero for success.
249 */
250int DSO_set_name_converter(DSO *dso, DSO_NAME_CONVERTER_FUNC cb,
251                           DSO_NAME_CONVERTER_FUNC *oldcb);
252/*
253 * These functions can be used to get/set the platform-independant filename
254 * used for a DSO. NB: set will fail if the DSO is already loaded.
255 */
256const char *DSO_get_filename(DSO *dso);
257int DSO_set_filename(DSO *dso, const char *filename);
258/*
259 * This function will invoke the DSO's name_converter callback to translate a
260 * filename, or if the callback isn't set it will instead use the DSO_METHOD's
261 * converter. If "filename" is NULL, the "filename" in the DSO itself will be
262 * used. If the DSO_FLAG_NO_NAME_TRANSLATION flag is set, then the filename is
263 * simply duplicated. NB: This function is usually called from within a
264 * DSO_METHOD during the processing of a DSO_load() call, and is exposed so
265 * that caller-created DSO_METHODs can do the same thing. A non-NULL return
266 * value will need to be OPENSSL_free()'d.
267 */
268char *DSO_convert_filename(DSO *dso, const char *filename);
269/*
270 * This function will invoke the DSO's merger callback to merge two file
271 * specifications, or if the callback isn't set it will instead use the
272 * DSO_METHOD's merger.  A non-NULL return value will need to be
273 * OPENSSL_free()'d.
274 */
275char *DSO_merge(DSO *dso, const char *filespec1, const char *filespec2);
276/*
277 * If the DSO is currently loaded, this returns the filename that it was
278 * loaded under, otherwise it returns NULL. So it is also useful as a test as
279 * to whether the DSO is currently loaded. NB: This will not necessarily
280 * return the same value as DSO_convert_filename(dso, dso->filename), because
281 * the DSO_METHOD's load function may have tried a variety of filenames (with
282 * and/or without the aid of the converters) before settling on the one it
283 * actually loaded.
284 */
285const char *DSO_get_loaded_filename(DSO *dso);
286
287void DSO_set_default_method(DSO_METHOD *meth);
288DSO_METHOD *DSO_get_default_method(void);
289DSO_METHOD *DSO_get_method(DSO *dso);
290DSO_METHOD *DSO_set_method(DSO *dso, DSO_METHOD *meth);
291
292/*
293 * The all-singing all-dancing load function, you normally pass NULL for the
294 * first and third parameters. Use DSO_up and DSO_free for subsequent
295 * reference count handling. Any flags passed in will be set in the
296 * constructed DSO after its init() function but before the load operation.
297 * If 'dso' is non-NULL, 'flags' is ignored.
298 */
299DSO *DSO_load(DSO *dso, const char *filename, DSO_METHOD *meth, int flags);
300
301/* This function binds to a variable inside a shared library. */
302void *DSO_bind_var(DSO *dso, const char *symname);
303
304/* This function binds to a function inside a shared library. */
305DSO_FUNC_TYPE DSO_bind_func(DSO *dso, const char *symname);
306
307/*
308 * This method is the default, but will beg, borrow, or steal whatever method
309 * should be the default on any particular platform (including
310 * DSO_METH_null() if necessary).
311 */
312DSO_METHOD *DSO_METHOD_openssl(void);
313
314/*
315 * This method is defined for all platforms - if a platform has no DSO
316 * support then this will be the only method!
317 */
318DSO_METHOD *DSO_METHOD_null(void);
319
320/*
321 * If DSO_DLFCN is defined, the standard dlfcn.h-style functions (dlopen,
322 * dlclose, dlsym, etc) will be used and incorporated into this method. If
323 * not, this method will return NULL.
324 */
325DSO_METHOD *DSO_METHOD_dlfcn(void);
326
327/*
328 * If DSO_DL is defined, the standard dl.h-style functions (shl_load,
329 * shl_unload, shl_findsym, etc) will be used and incorporated into this
330 * method. If not, this method will return NULL.
331 */
332DSO_METHOD *DSO_METHOD_dl(void);
333
334/* If WIN32 is defined, use DLLs. If not, return NULL. */
335DSO_METHOD *DSO_METHOD_win32(void);
336
337/* If VMS is defined, use shared images. If not, return NULL. */
338DSO_METHOD *DSO_METHOD_vms(void);
339
340/* BEGIN ERROR CODES */
341/*
342 * The following lines are auto generated by the script mkerr.pl. Any changes
343 * made after this point may be overwritten when the script is next run.
344 */
345void ERR_load_DSO_strings(void);
346
347/* Error codes for the DSO functions. */
348
349/* Function codes. */
350# define DSO_F_DLFCN_BIND_FUNC                            100
351# define DSO_F_DLFCN_BIND_VAR                             101
352# define DSO_F_DLFCN_LOAD                                 102
353# define DSO_F_DLFCN_MERGER                               130
354# define DSO_F_DLFCN_NAME_CONVERTER                       123
355# define DSO_F_DLFCN_UNLOAD                               103
356# define DSO_F_DL_BIND_FUNC                               104
357# define DSO_F_DL_BIND_VAR                                105
358# define DSO_F_DL_LOAD                                    106
359# define DSO_F_DL_MERGER                                  131
360# define DSO_F_DL_NAME_CONVERTER                          124
361# define DSO_F_DL_UNLOAD                                  107
362# define DSO_F_DSO_BIND_FUNC                              108
363# define DSO_F_DSO_BIND_VAR                               109
364# define DSO_F_DSO_CONVERT_FILENAME                       126
365# define DSO_F_DSO_CTRL                                   110
366# define DSO_F_DSO_FREE                                   111
367# define DSO_F_DSO_GET_FILENAME                           127
368# define DSO_F_DSO_GET_LOADED_FILENAME                    128
369# define DSO_F_DSO_LOAD                                   112
370# define DSO_F_DSO_MERGE                                  132
371# define DSO_F_DSO_NEW_METHOD                             113
372# define DSO_F_DSO_SET_FILENAME                           129
373# define DSO_F_DSO_SET_NAME_CONVERTER                     122
374# define DSO_F_DSO_UP_REF                                 114
375# define DSO_F_VMS_BIND_SYM                               115
376# define DSO_F_VMS_LOAD                                   116
377# define DSO_F_VMS_MERGER                                 133
378# define DSO_F_VMS_UNLOAD                                 117
379# define DSO_F_WIN32_BIND_FUNC                            118
380# define DSO_F_WIN32_BIND_VAR                             119
381# define DSO_F_WIN32_JOINER                               135
382# define DSO_F_WIN32_LOAD                                 120
383# define DSO_F_WIN32_MERGER                               134
384# define DSO_F_WIN32_NAME_CONVERTER                       125
385# define DSO_F_WIN32_SPLITTER                             136
386# define DSO_F_WIN32_UNLOAD                               121
387
388/* Reason codes. */
389# define DSO_R_CTRL_FAILED                                100
390# define DSO_R_DSO_ALREADY_LOADED                         110
391# define DSO_R_EMPTY_FILE_STRUCTURE                       113
392# define DSO_R_FAILURE                                    114
393# define DSO_R_FILENAME_TOO_BIG                           101
394# define DSO_R_FINISH_FAILED                              102
395# define DSO_R_INCORRECT_FILE_SYNTAX                      115
396# define DSO_R_LOAD_FAILED                                103
397# define DSO_R_NAME_TRANSLATION_FAILED                    109
398# define DSO_R_NO_FILENAME                                111
399# define DSO_R_NO_FILE_SPECIFICATION                      116
400# define DSO_R_NULL_HANDLE                                104
401# define DSO_R_SET_FILENAME_FAILED                        112
402# define DSO_R_STACK_ERROR                                105
403# define DSO_R_SYM_FAILURE                                106
404# define DSO_R_UNLOAD_FAILED                              107
405# define DSO_R_UNSUPPORTED                                108
406
407#ifdef  __cplusplus
408}
409#endif
410#endif
411