1/* dso.h */
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
99typedef void (*DSO_FUNC_TYPE)(void);
100
101typedef struct dso_st DSO;
102
103/* The function prototype used for method functions (or caller-provided
104 * callbacks) that transform filenames. They are passed a DSO structure pointer
105 * (or NULL if they are to be used independantly of a DSO object) and a
106 * filename to transform. They should either return NULL (if there is an error
107 * condition) or a newly allocated string containing the transformed form that
108 * the caller will need to free with OPENSSL_free() when done. */
109typedef char* (*DSO_NAME_CONVERTER_FUNC)(DSO *, const char *);
110
111typedef struct dso_meth_st
112	{
113	const char *name;
114	/* Loads a shared library, NB: new DSO_METHODs must ensure that a
115	 * successful load populates the loaded_filename field, and likewise a
116	 * successful unload OPENSSL_frees and NULLs it out. */
117	int (*dso_load)(DSO *dso);
118	/* Unloads a shared library */
119	int (*dso_unload)(DSO *dso);
120	/* Binds a variable */
121	void *(*dso_bind_var)(DSO *dso, const char *symname);
122	/* Binds a function - assumes a return type of DSO_FUNC_TYPE.
123	 * This should be cast to the real function prototype by the
124	 * caller. Platforms that don't have compatible representations
125	 * for different prototypes (this is possible within ANSI C)
126	 * are highly unlikely to have shared libraries at all, let
127	 * alone a DSO_METHOD implemented for them. */
128	DSO_FUNC_TYPE (*dso_bind_func)(DSO *dso, const char *symname);
129
130/* I don't think this would actually be used in any circumstances. */
131#if 0
132	/* Unbinds a variable */
133	int (*dso_unbind_var)(DSO *dso, char *symname, void *symptr);
134	/* Unbinds a function */
135	int (*dso_unbind_func)(DSO *dso, char *symname, DSO_FUNC_TYPE symptr);
136#endif
137	/* The generic (yuck) "ctrl()" function. NB: Negative return
138	 * values (rather than zero) indicate errors. */
139	long (*dso_ctrl)(DSO *dso, int cmd, long larg, void *parg);
140	/* The default DSO_METHOD-specific function for converting filenames to
141	 * a canonical native form. */
142	DSO_NAME_CONVERTER_FUNC dso_name_converter;
143
144	/* [De]Initialisation handlers. */
145	int (*init)(DSO *dso);
146	int (*finish)(DSO *dso);
147	} DSO_METHOD;
148
149/**********************************************************************/
150/* The low-level handle type used to refer to a loaded shared library */
151
152struct dso_st
153	{
154	DSO_METHOD *meth;
155	/* Standard dlopen uses a (void *). Win32 uses a HANDLE. VMS
156	 * doesn't use anything but will need to cache the filename
157	 * for use in the dso_bind handler. All in all, let each
158	 * method control its own destiny. "Handles" and such go in
159	 * a STACK. */
160	STACK *meth_data;
161	int references;
162	int flags;
163	/* For use by applications etc ... use this for your bits'n'pieces,
164	 * don't touch meth_data! */
165	CRYPTO_EX_DATA ex_data;
166	/* If this callback function pointer is set to non-NULL, then it will
167	 * be used on DSO_load() in place of meth->dso_name_converter. NB: This
168	 * should normally set using DSO_set_name_converter(). */
169	DSO_NAME_CONVERTER_FUNC name_converter;
170	/* This is populated with (a copy of) the platform-independant
171	 * filename used for this DSO. */
172	char *filename;
173	/* This is populated with (a copy of) the translated filename by which
174	 * the DSO was actually loaded. It is NULL iff the DSO is not currently
175	 * loaded. NB: This is here because the filename translation process
176	 * may involve a callback being invoked more than once not only to
177	 * convert to a platform-specific form, but also to try different
178	 * filenames in the process of trying to perform a load. As such, this
179	 * variable can be used to indicate (a) whether this DSO structure
180	 * corresponds to a loaded library or not, and (b) the filename with
181	 * which it was actually loaded. */
182	char *loaded_filename;
183	};
184
185
186DSO *	DSO_new(void);
187DSO *	DSO_new_method(DSO_METHOD *method);
188int	DSO_free(DSO *dso);
189int	DSO_flags(DSO *dso);
190int	DSO_up_ref(DSO *dso);
191long	DSO_ctrl(DSO *dso, int cmd, long larg, void *parg);
192
193/* This function sets the DSO's name_converter callback. If it is non-NULL,
194 * then it will be used instead of the associated DSO_METHOD's function. If
195 * oldcb is non-NULL then it is set to the function pointer value being
196 * replaced. Return value is non-zero for success. */
197int	DSO_set_name_converter(DSO *dso, DSO_NAME_CONVERTER_FUNC cb,
198				DSO_NAME_CONVERTER_FUNC *oldcb);
199/* These functions can be used to get/set the platform-independant filename
200 * used for a DSO. NB: set will fail if the DSO is already loaded. */
201const char *DSO_get_filename(DSO *dso);
202int	DSO_set_filename(DSO *dso, const char *filename);
203/* This function will invoke the DSO's name_converter callback to translate a
204 * filename, or if the callback isn't set it will instead use the DSO_METHOD's
205 * converter. If "filename" is NULL, the "filename" in the DSO itself will be
206 * used. If the DSO_FLAG_NO_NAME_TRANSLATION flag is set, then the filename is
207 * simply duplicated. NB: This function is usually called from within a
208 * DSO_METHOD during the processing of a DSO_load() call, and is exposed so that
209 * caller-created DSO_METHODs can do the same thing. A non-NULL return value
210 * will need to be OPENSSL_free()'d. */
211char	*DSO_convert_filename(DSO *dso, const char *filename);
212/* If the DSO is currently loaded, this returns the filename that it was loaded
213 * under, otherwise it returns NULL. So it is also useful as a test as to
214 * whether the DSO is currently loaded. NB: This will not necessarily return
215 * the same value as DSO_convert_filename(dso, dso->filename), because the
216 * DSO_METHOD's load function may have tried a variety of filenames (with
217 * and/or without the aid of the converters) before settling on the one it
218 * actually loaded. */
219const char *DSO_get_loaded_filename(DSO *dso);
220
221void	DSO_set_default_method(DSO_METHOD *meth);
222DSO_METHOD *DSO_get_default_method(void);
223DSO_METHOD *DSO_get_method(DSO *dso);
224DSO_METHOD *DSO_set_method(DSO *dso, DSO_METHOD *meth);
225
226/* The all-singing all-dancing load function, you normally pass NULL
227 * for the first and third parameters. Use DSO_up and DSO_free for
228 * subsequent reference count handling. Any flags passed in will be set
229 * in the constructed DSO after its init() function but before the
230 * load operation. If 'dso' is non-NULL, 'flags' is ignored. */
231DSO *DSO_load(DSO *dso, const char *filename, DSO_METHOD *meth, int flags);
232
233/* This function binds to a variable inside a shared library. */
234void *DSO_bind_var(DSO *dso, const char *symname);
235
236/* This function binds to a function inside a shared library. */
237DSO_FUNC_TYPE DSO_bind_func(DSO *dso, const char *symname);
238
239/* This method is the default, but will beg, borrow, or steal whatever
240 * method should be the default on any particular platform (including
241 * DSO_METH_null() if necessary). */
242DSO_METHOD *DSO_METHOD_openssl(void);
243
244/* This method is defined for all platforms - if a platform has no
245 * DSO support then this will be the only method! */
246DSO_METHOD *DSO_METHOD_null(void);
247
248/* If DSO_DLFCN is defined, the standard dlfcn.h-style functions
249 * (dlopen, dlclose, dlsym, etc) will be used and incorporated into
250 * this method. If not, this method will return NULL. */
251DSO_METHOD *DSO_METHOD_dlfcn(void);
252
253/* If DSO_DL is defined, the standard dl.h-style functions (shl_load,
254 * shl_unload, shl_findsym, etc) will be used and incorporated into
255 * this method. If not, this method will return NULL. */
256DSO_METHOD *DSO_METHOD_dl(void);
257
258/* If WIN32 is defined, use DLLs. If not, return NULL. */
259DSO_METHOD *DSO_METHOD_win32(void);
260
261/* If VMS is defined, use shared images. If not, return NULL. */
262DSO_METHOD *DSO_METHOD_vms(void);
263
264/* BEGIN ERROR CODES */
265/* The following lines are auto generated by the script mkerr.pl. Any changes
266 * made after this point may be overwritten when the script is next run.
267 */
268void ERR_load_DSO_strings(void);
269
270/* Error codes for the DSO functions. */
271
272/* Function codes. */
273#define DSO_F_DLFCN_BIND_FUNC				 100
274#define DSO_F_DLFCN_BIND_VAR				 101
275#define DSO_F_DLFCN_LOAD				 102
276#define DSO_F_DLFCN_NAME_CONVERTER			 123
277#define DSO_F_DLFCN_UNLOAD				 103
278#define DSO_F_DL_BIND_FUNC				 104
279#define DSO_F_DL_BIND_VAR				 105
280#define DSO_F_DL_LOAD					 106
281#define DSO_F_DL_NAME_CONVERTER				 124
282#define DSO_F_DL_UNLOAD					 107
283#define DSO_F_DSO_BIND_FUNC				 108
284#define DSO_F_DSO_BIND_VAR				 109
285#define DSO_F_DSO_CONVERT_FILENAME			 126
286#define DSO_F_DSO_CTRL					 110
287#define DSO_F_DSO_FREE					 111
288#define DSO_F_DSO_GET_FILENAME				 127
289#define DSO_F_DSO_GET_LOADED_FILENAME			 128
290#define DSO_F_DSO_LOAD					 112
291#define DSO_F_DSO_NEW_METHOD				 113
292#define DSO_F_DSO_SET_FILENAME				 129
293#define DSO_F_DSO_SET_NAME_CONVERTER			 122
294#define DSO_F_DSO_UP_REF				 114
295#define DSO_F_VMS_BIND_VAR				 115
296#define DSO_F_VMS_LOAD					 116
297#define DSO_F_VMS_UNLOAD				 117
298#define DSO_F_WIN32_BIND_FUNC				 118
299#define DSO_F_WIN32_BIND_VAR				 119
300#define DSO_F_WIN32_LOAD				 120
301#define DSO_F_WIN32_NAME_CONVERTER			 125
302#define DSO_F_WIN32_UNLOAD				 121
303
304/* Reason codes. */
305#define DSO_R_CTRL_FAILED				 100
306#define DSO_R_DSO_ALREADY_LOADED			 110
307#define DSO_R_FILENAME_TOO_BIG				 101
308#define DSO_R_FINISH_FAILED				 102
309#define DSO_R_LOAD_FAILED				 103
310#define DSO_R_NAME_TRANSLATION_FAILED			 109
311#define DSO_R_NO_FILENAME				 111
312#define DSO_R_NULL_HANDLE				 104
313#define DSO_R_SET_FILENAME_FAILED			 112
314#define DSO_R_STACK_ERROR				 105
315#define DSO_R_SYM_FAILURE				 106
316#define DSO_R_UNLOAD_FAILED				 107
317#define DSO_R_UNSUPPORTED				 108
318
319#ifdef  __cplusplus
320}
321#endif
322#endif
323