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@comcast.net
7 *
8 * http://www.fortran-2000.com/ArnaudRecipes/sharedlib.html
9 */
10
11 /* In order RTLD_GLOBAL and RTLD_NOW to be defined on zOS */
12 #if defined(__MVS__)
13 #define _UNIX03_SOURCE
14 #endif
15
16 #define IN_LIBXML
17 #include "libxml.h"
18
19 #include <string.h>
20 #include <libxml/xmlmodule.h>
21 #include <libxml/xmlmemory.h>
22 #include <libxml/xmlerror.h>
23 #include <libxml/xmlstring.h>
24
25 #include "private/error.h"
26
27 #ifdef LIBXML_MODULES_ENABLED
28
29 struct _xmlModule {
30 unsigned char *name;
31 void *handle;
32 };
33
34 static void *xmlModulePlatformOpen(const char *name);
35 static int xmlModulePlatformClose(void *handle);
36 static int xmlModulePlatformSymbol(void *handle, const char *name, void **result);
37
38 /************************************************************************
39 * *
40 * module memory error handler *
41 * *
42 ************************************************************************/
43
44 /**
45 * xmlModuleErrMemory:
46 * @extra: extra information
47 *
48 * Handle an out of memory condition
49 */
50 static void
51 xmlModuleErrMemory(xmlModulePtr module, const char *extra)
52 {
53 const char *name = NULL;
54
55 if (module != NULL) {
56 name = (const char *) module->name;
57 }
58
59 __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_MODULE,
60 XML_ERR_NO_MEMORY, XML_ERR_FATAL, NULL, 0, extra,
61 name, NULL, 0, 0,
62 "Memory allocation failed : %s\n", extra);
63 }
64
65 /**
66 * xmlModuleOpen:
67 * @name: the module name
68 * @options: a set of xmlModuleOption
69 *
70 * Opens a module/shared library given its name or path
71 * NOTE: that due to portability issues, behaviour can only be
72 * guaranteed with @name using ASCII. We cannot guarantee that
73 * an UTF-8 string would work, which is why name is a const char *
74 * and not a const xmlChar * .
75 * TODO: options are not yet implemented.
76 *
77 * Returns a handle for the module or NULL in case of error
78 */
79 xmlModulePtr
80 xmlModuleOpen(const char *name, int options ATTRIBUTE_UNUSED)
81 {
82 xmlModulePtr module;
83
84 module = (xmlModulePtr) xmlMalloc(sizeof(xmlModule));
85 if (module == NULL) {
86 xmlModuleErrMemory(NULL, "creating module");
87 return (NULL);
88 }
89
90 memset(module, 0, sizeof(xmlModule));
91
92 module->handle = xmlModulePlatformOpen(name);
93
94 if (module->handle == NULL) {
95 xmlFree(module);
96 __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_MODULE,
97 XML_MODULE_OPEN, XML_ERR_FATAL, NULL, 0, 0,
98 name, NULL, 0, 0, "failed to open %s\n", name);
99 return(NULL);
100 }
101
102 module->name = xmlStrdup((const xmlChar *) name);
103 return (module);
104 }
105
106 /**
107 * xmlModuleSymbol:
108 * @module: the module
109 * @name: the name of the symbol
110 * @symbol: the resulting symbol address
111 *
112 * Lookup for a symbol address in the given module
113 * NOTE: that due to portability issues, behaviour can only be
114 * guaranteed with @name using ASCII. We cannot guarantee that
115 * an UTF-8 string would work, which is why name is a const char *
116 * and not a const xmlChar * .
117 *
118 * Returns 0 if the symbol was found, or -1 in case of error
119 */
120 int
121 xmlModuleSymbol(xmlModulePtr module, const char *name, void **symbol)
122 {
123 int rc = -1;
124
125 if ((NULL == module) || (symbol == NULL) || (name == NULL)) {
126 __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_MODULE,
127 XML_MODULE_OPEN, XML_ERR_FATAL, NULL, 0, 0,
128 NULL, NULL, 0, 0, "null parameter\n");
129 return rc;
130 }
131
132 rc = xmlModulePlatformSymbol(module->handle, name, symbol);
133
134 if (rc == -1) {
135 __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_MODULE,
136 XML_MODULE_OPEN, XML_ERR_FATAL, NULL, 0, 0,
137 name, NULL, 0, 0,
138 "failed to find symbol: %s\n",
139 (name == NULL ? "NULL" : name));
140 return rc;
141 }
142
143 return rc;
144 }
145
146 /**
147 * xmlModuleClose:
148 * @module: the module handle
149 *
150 * The close operations unload the associated module and free the
151 * data associated to the module.
152 *
153 * Returns 0 in case of success, -1 in case of argument error and -2
154 * if the module could not be closed/unloaded.
155 */
156 int
157 xmlModuleClose(xmlModulePtr module)
158 {
159 int rc;
160
161 if (NULL == module) {
162 __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_MODULE,
163 XML_MODULE_CLOSE, XML_ERR_FATAL, NULL, 0, 0,
164 NULL, NULL, 0, 0, "null module pointer\n");
165 return -1;
166 }
167
168 rc = xmlModulePlatformClose(module->handle);
169
170 if (rc != 0) {
171 __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_MODULE,
172 XML_MODULE_CLOSE, XML_ERR_FATAL, NULL, 0, 0,
173 (const char *) module->name, NULL, 0, 0,
174 "failed to close: %s\n", module->name);
175 return -2;
176 }
177
178 rc = xmlModuleFree(module);
179 return (rc);
180 }
181
182 /**
183 * xmlModuleFree:
184 * @module: the module handle
185 *
186 * The free operations free the data associated to the module
187 * but does not unload the associated shared library which may still
188 * be in use.
189 *
190 * Returns 0 in case of success, -1 in case of argument error
191 */
192 int
193 xmlModuleFree(xmlModulePtr module)
194 {
195 if (NULL == module) {
196 __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_MODULE,
197 XML_MODULE_CLOSE, XML_ERR_FATAL, NULL, 0, NULL,
198 NULL, NULL, 0, 0, "null module pointer\n");
199 return -1;
200 }
201
202 xmlFree(module->name);
203 xmlFree(module);
204
205 return (0);
206 }
207
208 #if defined(HAVE_DLOPEN) && !defined(_WIN32)
209 #ifdef HAVE_DLFCN_H
210 #include <dlfcn.h>
211 #endif
212
213 #ifndef RTLD_GLOBAL /* For Tru64 UNIX 4.0 */
214 #define RTLD_GLOBAL 0
215 #endif
216
217 /**
218 * xmlModulePlatformOpen:
219 * @name: path to the module
220 *
221 * returns a handle on success, and zero on error.
222 */
223
224 static void *
225 xmlModulePlatformOpen(const char *name)
226 {
227 return dlopen(name, RTLD_GLOBAL | RTLD_NOW);
228 }
229
230 /*
231 * xmlModulePlatformClose:
232 * @handle: handle to the module
233 *
234 * returns 0 on success, and non-zero on error.
235 */
236
237 static int
238 xmlModulePlatformClose(void *handle)
239 {
240 return dlclose(handle);
241 }
242
243 /*
244 * xmlModulePlatformSymbol:
245 * http://www.opengroup.org/onlinepubs/009695399/functions/dlsym.html
246 * returns 0 on success and the loaded symbol in result, and -1 on error.
247 */
248
249 static int
250 xmlModulePlatformSymbol(void *handle, const char *name, void **symbol)
251 {
252 *symbol = dlsym(handle, name);
253 if (dlerror() != NULL) {
254 return -1;
255 }
256 return 0;
257 }
258
259 #else /* ! HAVE_DLOPEN */
260
261 #ifdef HAVE_SHLLOAD /* HAVE_SHLLOAD */
262 #ifdef HAVE_DL_H
263 #include <dl.h>
264 #endif
265 /*
266 * xmlModulePlatformOpen:
267 * returns a handle on success, and zero on error.
268 */
269
270 static void *
271 xmlModulePlatformOpen(const char *name)
272 {
273 return shl_load(name, BIND_IMMEDIATE, 0L);
274 }
275
276 /*
277 * xmlModulePlatformClose:
278 * returns 0 on success, and non-zero on error.
279 */
280
281 static int
282 xmlModulePlatformClose(void *handle)
283 {
284 return shl_unload(handle);
285 }
286
287 /*
288 * xmlModulePlatformSymbol:
289 * http://docs.hp.com/en/B2355-90683/shl_load.3X.html
290 * returns 0 on success and the loaded symbol in result, and -1 on error.
291 */
292
293 static int
294 xmlModulePlatformSymbol(void *handle, const char *name, void **symbol)
295 {
296 int rc;
297
298 errno = 0;
299 rc = shl_findsym(&handle, name, TYPE_UNDEFINED, symbol);
300 return rc;
301 }
302
303 #endif /* HAVE_SHLLOAD */
304 #endif /* ! HAVE_DLOPEN */
305
306 #if defined(_WIN32)
307
308 #define WIN32_LEAN_AND_MEAN
309 #include <windows.h>
310
311 /*
312 * xmlModulePlatformOpen:
313 * returns a handle on success, and zero on error.
314 */
315
316 static void *
317 xmlModulePlatformOpen(const char *name)
318 {
319 return LoadLibraryA(name);
320 }
321
322 /*
323 * xmlModulePlatformClose:
324 * returns 0 on success, and non-zero on error.
325 */
326
327 static int
328 xmlModulePlatformClose(void *handle)
329 {
330 int rc;
331
332 rc = FreeLibrary(handle);
333 return (0 == rc);
334 }
335
336 /*
337 * xmlModulePlatformSymbol:
338 * http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dllproc/base/getprocaddress.asp
339 * returns 0 on success and the loaded symbol in result, and -1 on error.
340 */
341
342 static int
343 xmlModulePlatformSymbol(void *handle, const char *name, void **symbol)
344 {
345 XML_IGNORE_FPTR_CAST_WARNINGS
346 *symbol = GetProcAddress(handle, name);
347 return (NULL == *symbol) ? -1 : 0;
348 XML_POP_WARNINGS
349 }
350
351 #endif /* _WIN32 */
352
353 #endif /* LIBXML_MODULES_ENABLED */