dso.h revision 280304
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 /* Return pathname of the module containing location */ 186 int (*pathbyaddr) (void *addr, char *path, int sz); 187 /* Perform global symbol lookup, i.e. among *all* modules */ 188 void *(*globallookup) (const char *symname); 189} DSO_METHOD; 190 191/**********************************************************************/ 192/* The low-level handle type used to refer to a loaded shared library */ 193 194struct dso_st { 195 DSO_METHOD *meth; 196 /* 197 * Standard dlopen uses a (void *). Win32 uses a HANDLE. VMS doesn't use 198 * anything but will need to cache the filename for use in the dso_bind 199 * handler. All in all, let each method control its own destiny. 200 * "Handles" and such go in a STACK. 201 */ 202 STACK_OF(void) *meth_data; 203 int references; 204 int flags; 205 /* 206 * For use by applications etc ... use this for your bits'n'pieces, don't 207 * touch meth_data! 208 */ 209 CRYPTO_EX_DATA ex_data; 210 /* 211 * If this callback function pointer is set to non-NULL, then it will be 212 * used in DSO_load() in place of meth->dso_name_converter. NB: This 213 * should normally set using DSO_set_name_converter(). 214 */ 215 DSO_NAME_CONVERTER_FUNC name_converter; 216 /* 217 * If this callback function pointer is set to non-NULL, then it will be 218 * used in DSO_load() in place of meth->dso_merger. NB: This should 219 * normally set using DSO_set_merger(). 220 */ 221 DSO_MERGER_FUNC merger; 222 /* 223 * This is populated with (a copy of) the platform-independant filename 224 * used for this DSO. 225 */ 226 char *filename; 227 /* 228 * This is populated with (a copy of) the translated filename by which 229 * the DSO was actually loaded. It is NULL iff the DSO is not currently 230 * loaded. NB: This is here because the filename translation process may 231 * involve a callback being invoked more than once not only to convert to 232 * a platform-specific form, but also to try different filenames in the 233 * process of trying to perform a load. As such, this variable can be 234 * used to indicate (a) whether this DSO structure corresponds to a 235 * loaded library or not, and (b) the filename with which it was actually 236 * loaded. 237 */ 238 char *loaded_filename; 239}; 240 241DSO *DSO_new(void); 242DSO *DSO_new_method(DSO_METHOD *method); 243int DSO_free(DSO *dso); 244int DSO_flags(DSO *dso); 245int DSO_up_ref(DSO *dso); 246long DSO_ctrl(DSO *dso, int cmd, long larg, void *parg); 247 248/* 249 * This function sets the DSO's name_converter callback. If it is non-NULL, 250 * then it will be used instead of the associated DSO_METHOD's function. If 251 * oldcb is non-NULL then it is set to the function pointer value being 252 * replaced. Return value is non-zero for success. 253 */ 254int DSO_set_name_converter(DSO *dso, DSO_NAME_CONVERTER_FUNC cb, 255 DSO_NAME_CONVERTER_FUNC *oldcb); 256/* 257 * These functions can be used to get/set the platform-independant filename 258 * used for a DSO. NB: set will fail if the DSO is already loaded. 259 */ 260const char *DSO_get_filename(DSO *dso); 261int DSO_set_filename(DSO *dso, const char *filename); 262/* 263 * This function will invoke the DSO's name_converter callback to translate a 264 * filename, or if the callback isn't set it will instead use the DSO_METHOD's 265 * converter. If "filename" is NULL, the "filename" in the DSO itself will be 266 * used. If the DSO_FLAG_NO_NAME_TRANSLATION flag is set, then the filename is 267 * simply duplicated. NB: This function is usually called from within a 268 * DSO_METHOD during the processing of a DSO_load() call, and is exposed so 269 * that caller-created DSO_METHODs can do the same thing. A non-NULL return 270 * value will need to be OPENSSL_free()'d. 271 */ 272char *DSO_convert_filename(DSO *dso, const char *filename); 273/* 274 * This function will invoke the DSO's merger callback to merge two file 275 * specifications, or if the callback isn't set it will instead use the 276 * DSO_METHOD's merger. A non-NULL return value will need to be 277 * OPENSSL_free()'d. 278 */ 279char *DSO_merge(DSO *dso, const char *filespec1, const char *filespec2); 280/* 281 * If the DSO is currently loaded, this returns the filename that it was 282 * loaded under, otherwise it returns NULL. So it is also useful as a test as 283 * to whether the DSO is currently loaded. NB: This will not necessarily 284 * return the same value as DSO_convert_filename(dso, dso->filename), because 285 * the DSO_METHOD's load function may have tried a variety of filenames (with 286 * and/or without the aid of the converters) before settling on the one it 287 * actually loaded. 288 */ 289const char *DSO_get_loaded_filename(DSO *dso); 290 291void DSO_set_default_method(DSO_METHOD *meth); 292DSO_METHOD *DSO_get_default_method(void); 293DSO_METHOD *DSO_get_method(DSO *dso); 294DSO_METHOD *DSO_set_method(DSO *dso, DSO_METHOD *meth); 295 296/* 297 * The all-singing all-dancing load function, you normally pass NULL for the 298 * first and third parameters. Use DSO_up and DSO_free for subsequent 299 * reference count handling. Any flags passed in will be set in the 300 * constructed DSO after its init() function but before the load operation. 301 * If 'dso' is non-NULL, 'flags' is ignored. 302 */ 303DSO *DSO_load(DSO *dso, const char *filename, DSO_METHOD *meth, int flags); 304 305/* This function binds to a variable inside a shared library. */ 306void *DSO_bind_var(DSO *dso, const char *symname); 307 308/* This function binds to a function inside a shared library. */ 309DSO_FUNC_TYPE DSO_bind_func(DSO *dso, const char *symname); 310 311/* 312 * This method is the default, but will beg, borrow, or steal whatever method 313 * should be the default on any particular platform (including 314 * DSO_METH_null() if necessary). 315 */ 316DSO_METHOD *DSO_METHOD_openssl(void); 317 318/* 319 * This method is defined for all platforms - if a platform has no DSO 320 * support then this will be the only method! 321 */ 322DSO_METHOD *DSO_METHOD_null(void); 323 324/* 325 * If DSO_DLFCN is defined, the standard dlfcn.h-style functions (dlopen, 326 * dlclose, dlsym, etc) will be used and incorporated into this method. If 327 * not, this method will return NULL. 328 */ 329DSO_METHOD *DSO_METHOD_dlfcn(void); 330 331/* 332 * If DSO_DL is defined, the standard dl.h-style functions (shl_load, 333 * shl_unload, shl_findsym, etc) will be used and incorporated into this 334 * method. If not, this method will return NULL. 335 */ 336DSO_METHOD *DSO_METHOD_dl(void); 337 338/* If WIN32 is defined, use DLLs. If not, return NULL. */ 339DSO_METHOD *DSO_METHOD_win32(void); 340 341/* If VMS is defined, use shared images. If not, return NULL. */ 342DSO_METHOD *DSO_METHOD_vms(void); 343 344/* 345 * This function writes null-terminated pathname of DSO module containing 346 * 'addr' into 'sz' large caller-provided 'path' and returns the number of 347 * characters [including trailing zero] written to it. If 'sz' is 0 or 348 * negative, 'path' is ignored and required amount of charachers [including 349 * trailing zero] to accomodate pathname is returned. If 'addr' is NULL, then 350 * pathname of cryptolib itself is returned. Negative or zero return value 351 * denotes error. 352 */ 353int DSO_pathbyaddr(void *addr, char *path, int sz); 354 355/* 356 * This function should be used with caution! It looks up symbols in *all* 357 * loaded modules and if module gets unloaded by somebody else attempt to 358 * dereference the pointer is doomed to have fatal consequences. Primary 359 * usage for this function is to probe *core* system functionality, e.g. 360 * check if getnameinfo(3) is available at run-time without bothering about 361 * OS-specific details such as libc.so.versioning or where does it actually 362 * reside: in libc itself or libsocket. 363 */ 364void *DSO_global_lookup(const char *name); 365 366/* If BeOS is defined, use shared images. If not, return NULL. */ 367DSO_METHOD *DSO_METHOD_beos(void); 368 369/* BEGIN ERROR CODES */ 370/* 371 * The following lines are auto generated by the script mkerr.pl. Any changes 372 * made after this point may be overwritten when the script is next run. 373 */ 374void ERR_load_DSO_strings(void); 375 376/* Error codes for the DSO functions. */ 377 378/* Function codes. */ 379# define DSO_F_BEOS_BIND_FUNC 144 380# define DSO_F_BEOS_BIND_VAR 145 381# define DSO_F_BEOS_LOAD 146 382# define DSO_F_BEOS_NAME_CONVERTER 147 383# define DSO_F_BEOS_UNLOAD 148 384# define DSO_F_DLFCN_BIND_FUNC 100 385# define DSO_F_DLFCN_BIND_VAR 101 386# define DSO_F_DLFCN_LOAD 102 387# define DSO_F_DLFCN_MERGER 130 388# define DSO_F_DLFCN_NAME_CONVERTER 123 389# define DSO_F_DLFCN_UNLOAD 103 390# define DSO_F_DL_BIND_FUNC 104 391# define DSO_F_DL_BIND_VAR 105 392# define DSO_F_DL_LOAD 106 393# define DSO_F_DL_MERGER 131 394# define DSO_F_DL_NAME_CONVERTER 124 395# define DSO_F_DL_UNLOAD 107 396# define DSO_F_DSO_BIND_FUNC 108 397# define DSO_F_DSO_BIND_VAR 109 398# define DSO_F_DSO_CONVERT_FILENAME 126 399# define DSO_F_DSO_CTRL 110 400# define DSO_F_DSO_FREE 111 401# define DSO_F_DSO_GET_FILENAME 127 402# define DSO_F_DSO_GET_LOADED_FILENAME 128 403# define DSO_F_DSO_GLOBAL_LOOKUP 139 404# define DSO_F_DSO_LOAD 112 405# define DSO_F_DSO_MERGE 132 406# define DSO_F_DSO_NEW_METHOD 113 407# define DSO_F_DSO_PATHBYADDR 140 408# define DSO_F_DSO_SET_FILENAME 129 409# define DSO_F_DSO_SET_NAME_CONVERTER 122 410# define DSO_F_DSO_UP_REF 114 411# define DSO_F_GLOBAL_LOOKUP_FUNC 138 412# define DSO_F_PATHBYADDR 137 413# define DSO_F_VMS_BIND_SYM 115 414# define DSO_F_VMS_LOAD 116 415# define DSO_F_VMS_MERGER 133 416# define DSO_F_VMS_UNLOAD 117 417# define DSO_F_WIN32_BIND_FUNC 118 418# define DSO_F_WIN32_BIND_VAR 119 419# define DSO_F_WIN32_GLOBALLOOKUP 142 420# define DSO_F_WIN32_GLOBALLOOKUP_FUNC 143 421# define DSO_F_WIN32_JOINER 135 422# define DSO_F_WIN32_LOAD 120 423# define DSO_F_WIN32_MERGER 134 424# define DSO_F_WIN32_NAME_CONVERTER 125 425# define DSO_F_WIN32_PATHBYADDR 141 426# define DSO_F_WIN32_SPLITTER 136 427# define DSO_F_WIN32_UNLOAD 121 428 429/* Reason codes. */ 430# define DSO_R_CTRL_FAILED 100 431# define DSO_R_DSO_ALREADY_LOADED 110 432# define DSO_R_EMPTY_FILE_STRUCTURE 113 433# define DSO_R_FAILURE 114 434# define DSO_R_FILENAME_TOO_BIG 101 435# define DSO_R_FINISH_FAILED 102 436# define DSO_R_INCORRECT_FILE_SYNTAX 115 437# define DSO_R_LOAD_FAILED 103 438# define DSO_R_NAME_TRANSLATION_FAILED 109 439# define DSO_R_NO_FILENAME 111 440# define DSO_R_NO_FILE_SPECIFICATION 116 441# define DSO_R_NULL_HANDLE 104 442# define DSO_R_SET_FILENAME_FAILED 112 443# define DSO_R_STACK_ERROR 105 444# define DSO_R_SYM_FAILURE 106 445# define DSO_R_UNLOAD_FAILED 107 446# define DSO_R_UNSUPPORTED 108 447 448#ifdef __cplusplus 449} 450#endif 451#endif 452