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      1 /*
      2  * xmlmodule.c : basic API for dynamic module loading added 2.6.17
      3  *
      4  * See Copyright for the status of this software.
      5  *
      6  * joelwreed (at) comcast.net
      7  *
      8  * http://www.fortran-2000.com/ArnaudRecipes/sharedlib.html
      9  */
     10 
     11 #define IN_LIBXML
     12 #include "libxml.h"
     13 
     14 #include <string.h>
     15 #include <libxml/xmlmemory.h>
     16 #include <libxml/xmlerror.h>
     17 #include <libxml/xmlmodule.h>
     18 #include <libxml/globals.h>
     19 
     20 #ifdef LIBXML_MODULES_ENABLED
     21 
     22 struct _xmlModule {
     23     unsigned char *name;
     24     void *handle;
     25 };
     26 
     27 static void *xmlModulePlatformOpen(const char *name);
     28 static int xmlModulePlatformClose(void *handle);
     29 static int xmlModulePlatformSymbol(void *handle, const char *name, void **result);
     30 
     31 /************************************************************************
     32  *									*
     33  *		module memory error handler				*
     34  *									*
     35  ************************************************************************/
     36 
     37 /**
     38  * xmlModuleErrMemory:
     39  * @extra:  extra information
     40  *
     41  * Handle an out of memory condition
     42  */
     43 static void
     44 xmlModuleErrMemory(xmlModulePtr module, const char *extra)
     45 {
     46     const char *name = NULL;
     47 
     48     if (module != NULL) {
     49         name = (const char *) module->name;
     50     }
     51 
     52     __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_MODULE,
     53                     XML_ERR_NO_MEMORY, XML_ERR_FATAL, NULL, 0, extra,
     54                     name, NULL, 0, 0,
     55                     "Memory allocation failed : %s\n", extra);
     56 }
     57 
     58 /**
     59  * xmlModuleOpen:
     60  * @name: the module name
     61  * @options: a set of xmlModuleOption
     62  *
     63  * Opens a module/shared library given its name or path
     64  * NOTE: that due to portability issues, behaviour can only be
     65  * guaranteed with @name using ASCII. We canot guarantee that
     66  * an UTF-8 string would work, which is why name is a const char *
     67  * and not a const xmlChar * .
     68  * TODO: options are not yet implemented.
     69  *
     70  * Returns a handle for the module or NULL in case of error
     71  */
     72 xmlModulePtr
     73 xmlModuleOpen(const char *name, int options ATTRIBUTE_UNUSED)
     74 {
     75     xmlModulePtr module;
     76 
     77     module = (xmlModulePtr) xmlMalloc(sizeof(xmlModule));
     78     if (module == NULL) {
     79         xmlModuleErrMemory(NULL, "creating module");
     80         return (NULL);
     81     }
     82 
     83     memset(module, 0, sizeof(xmlModule));
     84 
     85     module->handle = xmlModulePlatformOpen(name);
     86 
     87     if (module->handle == NULL) {
     88         xmlFree(module);
     89         __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_MODULE,
     90                         XML_MODULE_OPEN, XML_ERR_FATAL, NULL, 0, 0,
     91                         name, NULL, 0, 0, "failed to open %s\n", name);
     92         return(NULL);
     93     }
     94 
     95     module->name = xmlStrdup((const xmlChar *) name);
     96     return (module);
     97 }
     98 
     99 /**
    100  * xmlModuleSymbol:
    101  * @module: the module
    102  * @name: the name of the symbol
    103  * @symbol: the resulting symbol address
    104  *
    105  * Lookup for a symbol address in the given module
    106  * NOTE: that due to portability issues, behaviour can only be
    107  * guaranteed with @name using ASCII. We canot guarantee that
    108  * an UTF-8 string would work, which is why name is a const char *
    109  * and not a const xmlChar * .
    110  *
    111  * Returns 0 if the symbol was found, or -1 in case of error
    112  */
    113 int
    114 xmlModuleSymbol(xmlModulePtr module, const char *name, void **symbol)
    115 {
    116     int rc = -1;
    117 
    118     if ((NULL == module) || (symbol == NULL) || (name == NULL)) {
    119         __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_MODULE,
    120                         XML_MODULE_OPEN, XML_ERR_FATAL, NULL, 0, 0,
    121                         NULL, NULL, 0, 0, "null parameter\n");
    122         return rc;
    123     }
    124 
    125     rc = xmlModulePlatformSymbol(module->handle, name, symbol);
    126 
    127     if (rc == -1) {
    128         __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_MODULE,
    129                         XML_MODULE_OPEN, XML_ERR_FATAL, NULL, 0, 0,
    130                         name, NULL, 0, 0,
    131                         "failed to find symbol: %s\n",
    132 			(name == NULL ? "NULL" : name));
    133         return rc;
    134     }
    135 
    136     return rc;
    137 }
    138 
    139 /**
    140  * xmlModuleClose:
    141  * @module: the module handle
    142  *
    143  * The close operations unload the associated module and free the
    144  * data associated to the module.
    145  *
    146  * Returns 0 in case of success, -1 in case of argument error and -2
    147  *         if the module could not be closed/unloaded.
    148  */
    149 int
    150 xmlModuleClose(xmlModulePtr module)
    151 {
    152     int rc;
    153 
    154     if (NULL == module) {
    155         __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_MODULE,
    156                         XML_MODULE_CLOSE, XML_ERR_FATAL, NULL, 0, 0,
    157                         NULL, NULL, 0, 0, "null module pointer\n");
    158         return -1;
    159     }
    160 
    161     rc = xmlModulePlatformClose(module->handle);
    162 
    163     if (rc != 0) {
    164         __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_MODULE,
    165                         XML_MODULE_CLOSE, XML_ERR_FATAL, NULL, 0, 0,
    166                         (const char *) module->name, NULL, 0, 0,
    167                         "failed to close: %s\n", module->name);
    168         return -2;
    169     }
    170 
    171     rc = xmlModuleFree(module);
    172     return (rc);
    173 }
    174 
    175 /**
    176  * xmlModuleFree:
    177  * @module: the module handle
    178  *
    179  * The free operations free the data associated to the module
    180  * but does not unload the associated shared library which may still
    181  * be in use.
    182  *
    183  * Returns 0 in case of success, -1 in case of argument error
    184  */
    185 int
    186 xmlModuleFree(xmlModulePtr module)
    187 {
    188     if (NULL == module) {
    189         __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_MODULE,
    190                         XML_MODULE_CLOSE, XML_ERR_FATAL, NULL, 0, NULL,
    191                         NULL, NULL, 0, 0, "null module pointer\n");
    192         return -1;
    193     }
    194 
    195     xmlFree(module->name);
    196     xmlFree(module);
    197 
    198     return (0);
    199 }
    200 
    201 #if defined(HAVE_DLOPEN) && !defined(_WIN32)
    202 #ifdef HAVE_DLFCN_H
    203 #include <dlfcn.h>
    204 #endif
    205 
    206 #ifndef RTLD_GLOBAL            /* For Tru64 UNIX 4.0 */
    207 #define RTLD_GLOBAL 0
    208 #endif
    209 
    210 /**
    211  * xmlModulePlatformOpen:
    212  * @name: path to the module
    213  *
    214  * returns a handle on success, and zero on error.
    215  */
    216 
    217 static void *
    218 xmlModulePlatformOpen(const char *name)
    219 {
    220     return dlopen(name, RTLD_GLOBAL | RTLD_NOW);
    221 }
    222 
    223 /*
    224  * xmlModulePlatformClose:
    225  * @handle: handle to the module
    226  *
    227  * returns 0 on success, and non-zero on error.
    228  */
    229 
    230 static int
    231 xmlModulePlatformClose(void *handle)
    232 {
    233     return dlclose(handle);
    234 }
    235 
    236 /*
    237  * xmlModulePlatformSymbol:
    238  * http://www.opengroup.org/onlinepubs/009695399/functions/dlsym.html
    239  * returns 0 on success and the loaded symbol in result, and -1 on error.
    240  */
    241 
    242 static int
    243 xmlModulePlatformSymbol(void *handle, const char *name, void **symbol)
    244 {
    245     *symbol = dlsym(handle, name);
    246     if (dlerror() != NULL) {
    247 	return -1;
    248     }
    249     return 0;
    250 }
    251 
    252 #else /* ! HAVE_DLOPEN */
    253 
    254 #ifdef HAVE_SHLLOAD             /* HAVE_SHLLOAD */
    255 #ifdef HAVE_DL_H
    256 #include <dl.h>
    257 #endif
    258 /*
    259  * xmlModulePlatformOpen:
    260  * returns a handle on success, and zero on error.
    261  */
    262 
    263 static void *
    264 xmlModulePlatformOpen(const char *name)
    265 {
    266     return shl_load(name, BIND_IMMEDIATE, 0L);
    267 }
    268 
    269 /*
    270  * xmlModulePlatformClose:
    271  * returns 0 on success, and non-zero on error.
    272  */
    273 
    274 static int
    275 xmlModulePlatformClose(void *handle)
    276 {
    277     return shl_unload(handle);
    278 }
    279 
    280 /*
    281  * xmlModulePlatformSymbol:
    282  * http://docs.hp.com/en/B2355-90683/shl_load.3X.html
    283  * returns 0 on success and the loaded symbol in result, and -1 on error.
    284  */
    285 
    286 static int
    287 xmlModulePlatformSymbol(void *handle, const char *name, void **symbol)
    288 {
    289     int rc;
    290 
    291     errno = 0;
    292     rc = shl_findsym(&handle, name, TYPE_UNDEFINED, symbol);
    293     return rc;
    294 }
    295 
    296 #endif /* HAVE_SHLLOAD */
    297 #endif /* ! HAVE_DLOPEN */
    298 
    299 #ifdef _WIN32
    300 
    301 #include <windows.h>
    302 
    303 /*
    304  * xmlModulePlatformOpen:
    305  * returns a handle on success, and zero on error.
    306  */
    307 
    308 static void *
    309 xmlModulePlatformOpen(const char *name)
    310 {
    311     return LoadLibraryA(name);
    312 }
    313 
    314 /*
    315  * xmlModulePlatformClose:
    316  * returns 0 on success, and non-zero on error.
    317  */
    318 
    319 static int
    320 xmlModulePlatformClose(void *handle)
    321 {
    322     int rc;
    323 
    324     rc = FreeLibrary(handle);
    325     return (0 == rc);
    326 }
    327 
    328 /*
    329  * xmlModulePlatformSymbol:
    330  * http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dllproc/base/getprocaddress.asp
    331  * returns 0 on success and the loaded symbol in result, and -1 on error.
    332  */
    333 
    334 static int
    335 xmlModulePlatformSymbol(void *handle, const char *name, void **symbol)
    336 {
    337 #ifdef _WIN32_WCE
    338     /*
    339      * GetProcAddressA seems only available on WinCE
    340      */
    341     *symbol = GetProcAddressA(handle, name);
    342 #else
    343     *symbol = GetProcAddress(handle, name);
    344 #endif
    345     return (NULL == *symbol) ? -1 : 0;
    346 }
    347 
    348 #endif /* _WIN32 */
    349 
    350 #ifdef HAVE_BEOS
    351 
    352 #include <kernel/image.h>
    353 
    354 /*
    355  * xmlModulePlatformOpen:
    356  * beos api info: http://www.beunited.org/bebook/The%20Kernel%20Kit/Images.html
    357  * returns a handle on success, and zero on error.
    358  */
    359 
    360 static void *
    361 xmlModulePlatformOpen(const char *name)
    362 {
    363     return (void *) load_add_on(name);
    364 }
    365 
    366 /*
    367  * xmlModulePlatformClose:
    368  * beos api info: http://www.beunited.org/bebook/The%20Kernel%20Kit/Images.html
    369  * returns 0 on success, and non-zero on error.
    370  */
    371 
    372 static int
    373 xmlModulePlatformClose(void *handle)
    374 {
    375     status_t rc;
    376 
    377     rc = unload_add_on((image_id) handle);
    378 
    379     if (rc == B_OK)
    380         return 0;
    381     else
    382         return -1;
    383 }
    384 
    385 /*
    386  * xmlModulePlatformSymbol:
    387  * beos api info: http://www.beunited.org/bebook/The%20Kernel%20Kit/Images.html
    388  * returns 0 on success and the loaded symbol in result, and -1 on error.
    389  */
    390 
    391 static int
    392 xmlModulePlatformSymbol(void *handle, const char *name, void **symbol)
    393 {
    394     status_t rc;
    395 
    396     rc = get_image_symbol((image_id) handle, name, B_SYMBOL_TYPE_ANY, symbol);
    397 
    398     return (rc == B_OK) ? 0 : -1;
    399 }
    400 
    401 #endif /* HAVE_BEOS */
    402 
    403 #ifdef HAVE_OS2
    404 
    405 #include <os2.h>
    406 
    407 /*
    408  * xmlModulePlatformOpen:
    409  * os2 api info: http://www.edm2.com/os2api/Dos/DosLoadModule.html
    410  * returns a handle on success, and zero on error.
    411  */
    412 
    413 static void *
    414 xmlModulePlatformOpen(const char *name)
    415 {
    416     char errbuf[256];
    417     void *handle;
    418     int rc;
    419 
    420     rc = DosLoadModule(errbuf, sizeof(errbuf) - 1, name, &handle);
    421 
    422     if (rc)
    423         return 0;
    424     else
    425         return (handle);
    426 }
    427 
    428 /*
    429  * xmlModulePlatformClose:
    430  * os2 api info: http://www.edm2.com/os2api/Dos/DosFreeModule.html
    431  * returns 0 on success, and non-zero on error.
    432  */
    433 
    434 static int
    435 xmlModulePlatformClose(void *handle)
    436 {
    437     return DosFreeModule(handle);
    438 }
    439 
    440 /*
    441  * xmlModulePlatformSymbol:
    442  * os2 api info: http://www.edm2.com/os2api/Dos/DosQueryProcAddr.html
    443  * returns 0 on success and the loaded symbol in result, and -1 on error.
    444  */
    445 
    446 static int
    447 xmlModulePlatformSymbol(void *handle, const char *name, void **symbol)
    448 {
    449     int rc;
    450 
    451     rc = DosQueryProcAddr(handle, 0, name, symbol);
    452 
    453     return (rc == NO_ERROR) ? 0 : -1;
    454 }
    455 
    456 #endif /* HAVE_OS2 */
    457 
    458 #define bottom_xmlmodule
    459 #include "elfgcchack.h"
    460 #endif /* LIBXML_MODULES_ENABLED */
    461