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
  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 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 
 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 OPENSSL_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 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. */
 132 typedef char* (*DSO_MERGER_FUNC)(DSO *, const char *, const char *);
 133 
 134 typedef 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 
 183 struct 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 
 221 DSO *   DSO_new(void);
 222 DSO *   DSO_new_method(DSO_METHOD *method);
 223 int     DSO_free(DSO *dso);
 224 int     DSO_flags(DSO *dso);
 225 int     DSO_up_ref(DSO *dso);
 226 long    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. */
 232 int     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. */
 236 const char *DSO_get_filename(DSO *dso);
 237 int     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. */
 246 char    *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. */
 251 char    *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. */
 259 const char *DSO_get_loaded_filename(DSO *dso);
 260 
 261 void    DSO_set_default_method(DSO_METHOD *meth);
 262 DSO_METHOD *DSO_get_default_method(void);
 263 DSO_METHOD *DSO_get_method(DSO *dso);
 264 DSO_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. */
 271 DSO *DSO_load(DSO *dso, const char *filename, DSO_METHOD *meth, int flags);
 272 
 273 /* This function binds to a variable inside a shared library. */
 274 void *DSO_bind_var(DSO *dso, const char *symname);
 275 
 276 /* This function binds to a function inside a shared library. */
 277 DSO_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). */
 282 DSO_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! */
 286 DSO_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. */
 291 DSO_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. */
 296 DSO_METHOD *DSO_METHOD_dl(void);
 297 
 298 /* If WIN32 is defined, use DLLs. If not, return NULL. */
 299 DSO_METHOD *DSO_METHOD_win32(void);
 300 
 301 /* If VMS is defined, use shared images. If not, return NULL. */
 302 DSO_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  */
 313 int 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. */
 323 void *DSO_global_lookup(const char *name);
 324 
 325 /* If BeOS is defined, use shared images. If not, return NULL. */
 326 DSO_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  */
 332 void 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