xref: /sqlite-3.40.0/src/loadext.c (revision f2fcd075)
1 /*
2 ** 2006 June 7
3 **
4 ** The author disclaims copyright to this source code.  In place of
5 ** a legal notice, here is a blessing:
6 **
7 **    May you do good and not evil.
8 **    May you find forgiveness for yourself and forgive others.
9 **    May you share freely, never taking more than you give.
10 **
11 *************************************************************************
12 ** This file contains code used to dynamically load extensions into
13 ** the SQLite library.
14 */
15 
16 #ifndef SQLITE_CORE
17   #define SQLITE_CORE 1  /* Disable the API redefinition in sqlite3ext.h */
18 #endif
19 #include "sqlite3ext.h"
20 #include "sqliteInt.h"
21 #include <string.h>
22 
23 #ifndef SQLITE_OMIT_LOAD_EXTENSION
24 
25 /*
26 ** Some API routines are omitted when various features are
27 ** excluded from a build of SQLite.  Substitute a NULL pointer
28 ** for any missing APIs.
29 */
30 #ifndef SQLITE_ENABLE_COLUMN_METADATA
31 # define sqlite3_column_database_name   0
32 # define sqlite3_column_database_name16 0
33 # define sqlite3_column_table_name      0
34 # define sqlite3_column_table_name16    0
35 # define sqlite3_column_origin_name     0
36 # define sqlite3_column_origin_name16   0
37 # define sqlite3_table_column_metadata  0
38 #endif
39 
40 #ifdef SQLITE_OMIT_AUTHORIZATION
41 # define sqlite3_set_authorizer         0
42 #endif
43 
44 #ifdef SQLITE_OMIT_UTF16
45 # define sqlite3_bind_text16            0
46 # define sqlite3_collation_needed16     0
47 # define sqlite3_column_decltype16      0
48 # define sqlite3_column_name16          0
49 # define sqlite3_column_text16          0
50 # define sqlite3_complete16             0
51 # define sqlite3_create_collation16     0
52 # define sqlite3_create_function16      0
53 # define sqlite3_errmsg16               0
54 # define sqlite3_open16                 0
55 # define sqlite3_prepare16              0
56 # define sqlite3_prepare16_v2           0
57 # define sqlite3_result_error16         0
58 # define sqlite3_result_text16          0
59 # define sqlite3_result_text16be        0
60 # define sqlite3_result_text16le        0
61 # define sqlite3_value_text16           0
62 # define sqlite3_value_text16be         0
63 # define sqlite3_value_text16le         0
64 # define sqlite3_column_database_name16 0
65 # define sqlite3_column_table_name16    0
66 # define sqlite3_column_origin_name16   0
67 #endif
68 
69 #ifdef SQLITE_OMIT_COMPLETE
70 # define sqlite3_complete 0
71 # define sqlite3_complete16 0
72 #endif
73 
74 #ifdef SQLITE_OMIT_PROGRESS_CALLBACK
75 # define sqlite3_progress_handler 0
76 #endif
77 
78 #ifdef SQLITE_OMIT_VIRTUALTABLE
79 # define sqlite3_create_module 0
80 # define sqlite3_create_module_v2 0
81 # define sqlite3_declare_vtab 0
82 #endif
83 
84 #ifdef SQLITE_OMIT_SHARED_CACHE
85 # define sqlite3_enable_shared_cache 0
86 #endif
87 
88 #ifdef SQLITE_OMIT_TRACE
89 # define sqlite3_profile       0
90 # define sqlite3_trace         0
91 #endif
92 
93 #ifdef SQLITE_OMIT_GET_TABLE
94 # define sqlite3_free_table    0
95 # define sqlite3_get_table     0
96 #endif
97 
98 #ifdef SQLITE_OMIT_INCRBLOB
99 #define sqlite3_bind_zeroblob  0
100 #define sqlite3_blob_bytes     0
101 #define sqlite3_blob_close     0
102 #define sqlite3_blob_open      0
103 #define sqlite3_blob_read      0
104 #define sqlite3_blob_write     0
105 #endif
106 
107 /*
108 ** The following structure contains pointers to all SQLite API routines.
109 ** A pointer to this structure is passed into extensions when they are
110 ** loaded so that the extension can make calls back into the SQLite
111 ** library.
112 **
113 ** When adding new APIs, add them to the bottom of this structure
114 ** in order to preserve backwards compatibility.
115 **
116 ** Extensions that use newer APIs should first call the
117 ** sqlite3_libversion_number() to make sure that the API they
118 ** intend to use is supported by the library.  Extensions should
119 ** also check to make sure that the pointer to the function is
120 ** not NULL before calling it.
121 */
122 static const sqlite3_api_routines sqlite3Apis = {
123   sqlite3_aggregate_context,
124 #ifndef SQLITE_OMIT_DEPRECATED
125   sqlite3_aggregate_count,
126 #else
127   0,
128 #endif
129   sqlite3_bind_blob,
130   sqlite3_bind_double,
131   sqlite3_bind_int,
132   sqlite3_bind_int64,
133   sqlite3_bind_null,
134   sqlite3_bind_parameter_count,
135   sqlite3_bind_parameter_index,
136   sqlite3_bind_parameter_name,
137   sqlite3_bind_text,
138   sqlite3_bind_text16,
139   sqlite3_bind_value,
140   sqlite3_busy_handler,
141   sqlite3_busy_timeout,
142   sqlite3_changes,
143   sqlite3_close,
144   sqlite3_collation_needed,
145   sqlite3_collation_needed16,
146   sqlite3_column_blob,
147   sqlite3_column_bytes,
148   sqlite3_column_bytes16,
149   sqlite3_column_count,
150   sqlite3_column_database_name,
151   sqlite3_column_database_name16,
152   sqlite3_column_decltype,
153   sqlite3_column_decltype16,
154   sqlite3_column_double,
155   sqlite3_column_int,
156   sqlite3_column_int64,
157   sqlite3_column_name,
158   sqlite3_column_name16,
159   sqlite3_column_origin_name,
160   sqlite3_column_origin_name16,
161   sqlite3_column_table_name,
162   sqlite3_column_table_name16,
163   sqlite3_column_text,
164   sqlite3_column_text16,
165   sqlite3_column_type,
166   sqlite3_column_value,
167   sqlite3_commit_hook,
168   sqlite3_complete,
169   sqlite3_complete16,
170   sqlite3_create_collation,
171   sqlite3_create_collation16,
172   sqlite3_create_function,
173   sqlite3_create_function16,
174   sqlite3_create_module,
175   sqlite3_data_count,
176   sqlite3_db_handle,
177   sqlite3_declare_vtab,
178   sqlite3_enable_shared_cache,
179   sqlite3_errcode,
180   sqlite3_errmsg,
181   sqlite3_errmsg16,
182   sqlite3_exec,
183 #ifndef SQLITE_OMIT_DEPRECATED
184   sqlite3_expired,
185 #else
186   0,
187 #endif
188   sqlite3_finalize,
189   sqlite3_free,
190   sqlite3_free_table,
191   sqlite3_get_autocommit,
192   sqlite3_get_auxdata,
193   sqlite3_get_table,
194   0,     /* Was sqlite3_global_recover(), but that function is deprecated */
195   sqlite3_interrupt,
196   sqlite3_last_insert_rowid,
197   sqlite3_libversion,
198   sqlite3_libversion_number,
199   sqlite3_malloc,
200   sqlite3_mprintf,
201   sqlite3_open,
202   sqlite3_open16,
203   sqlite3_prepare,
204   sqlite3_prepare16,
205   sqlite3_profile,
206   sqlite3_progress_handler,
207   sqlite3_realloc,
208   sqlite3_reset,
209   sqlite3_result_blob,
210   sqlite3_result_double,
211   sqlite3_result_error,
212   sqlite3_result_error16,
213   sqlite3_result_int,
214   sqlite3_result_int64,
215   sqlite3_result_null,
216   sqlite3_result_text,
217   sqlite3_result_text16,
218   sqlite3_result_text16be,
219   sqlite3_result_text16le,
220   sqlite3_result_value,
221   sqlite3_rollback_hook,
222   sqlite3_set_authorizer,
223   sqlite3_set_auxdata,
224   sqlite3_snprintf,
225   sqlite3_step,
226   sqlite3_table_column_metadata,
227 #ifndef SQLITE_OMIT_DEPRECATED
228   sqlite3_thread_cleanup,
229 #else
230   0,
231 #endif
232   sqlite3_total_changes,
233   sqlite3_trace,
234 #ifndef SQLITE_OMIT_DEPRECATED
235   sqlite3_transfer_bindings,
236 #else
237   0,
238 #endif
239   sqlite3_update_hook,
240   sqlite3_user_data,
241   sqlite3_value_blob,
242   sqlite3_value_bytes,
243   sqlite3_value_bytes16,
244   sqlite3_value_double,
245   sqlite3_value_int,
246   sqlite3_value_int64,
247   sqlite3_value_numeric_type,
248   sqlite3_value_text,
249   sqlite3_value_text16,
250   sqlite3_value_text16be,
251   sqlite3_value_text16le,
252   sqlite3_value_type,
253   sqlite3_vmprintf,
254   /*
255   ** The original API set ends here.  All extensions can call any
256   ** of the APIs above provided that the pointer is not NULL.  But
257   ** before calling APIs that follow, extension should check the
258   ** sqlite3_libversion_number() to make sure they are dealing with
259   ** a library that is new enough to support that API.
260   *************************************************************************
261   */
262   sqlite3_overload_function,
263 
264   /*
265   ** Added after 3.3.13
266   */
267   sqlite3_prepare_v2,
268   sqlite3_prepare16_v2,
269   sqlite3_clear_bindings,
270 
271   /*
272   ** Added for 3.4.1
273   */
274   sqlite3_create_module_v2,
275 
276   /*
277   ** Added for 3.5.0
278   */
279   sqlite3_bind_zeroblob,
280   sqlite3_blob_bytes,
281   sqlite3_blob_close,
282   sqlite3_blob_open,
283   sqlite3_blob_read,
284   sqlite3_blob_write,
285   sqlite3_create_collation_v2,
286   sqlite3_file_control,
287   sqlite3_memory_highwater,
288   sqlite3_memory_used,
289 #ifdef SQLITE_MUTEX_OMIT
290   0,
291   0,
292   0,
293   0,
294   0,
295 #else
296   sqlite3_mutex_alloc,
297   sqlite3_mutex_enter,
298   sqlite3_mutex_free,
299   sqlite3_mutex_leave,
300   sqlite3_mutex_try,
301 #endif
302   sqlite3_open_v2,
303   sqlite3_release_memory,
304   sqlite3_result_error_nomem,
305   sqlite3_result_error_toobig,
306   sqlite3_sleep,
307   sqlite3_soft_heap_limit,
308   sqlite3_vfs_find,
309   sqlite3_vfs_register,
310   sqlite3_vfs_unregister,
311 
312   /*
313   ** Added for 3.5.8
314   */
315   sqlite3_threadsafe,
316   sqlite3_result_zeroblob,
317   sqlite3_result_error_code,
318   sqlite3_test_control,
319   sqlite3_randomness,
320   sqlite3_context_db_handle,
321 
322   /*
323   ** Added for 3.6.0
324   */
325   sqlite3_extended_result_codes,
326   sqlite3_limit,
327   sqlite3_next_stmt,
328   sqlite3_sql,
329   sqlite3_status,
330 };
331 
332 /*
333 ** Attempt to load an SQLite extension library contained in the file
334 ** zFile.  The entry point is zProc.  zProc may be 0 in which case a
335 ** default entry point name (sqlite3_extension_init) is used.  Use
336 ** of the default name is recommended.
337 **
338 ** Return SQLITE_OK on success and SQLITE_ERROR if something goes wrong.
339 **
340 ** If an error occurs and pzErrMsg is not 0, then fill *pzErrMsg with
341 ** error message text.  The calling function should free this memory
342 ** by calling sqlite3DbFree(db, ).
343 */
344 static int sqlite3LoadExtension(
345   sqlite3 *db,          /* Load the extension into this database connection */
346   const char *zFile,    /* Name of the shared library containing extension */
347   const char *zProc,    /* Entry point.  Use "sqlite3_extension_init" if 0 */
348   char **pzErrMsg       /* Put error message here if not 0 */
349 ){
350   sqlite3_vfs *pVfs = db->pVfs;
351   void *handle;
352   int (*xInit)(sqlite3*,char**,const sqlite3_api_routines*);
353   char *zErrmsg = 0;
354   void **aHandle;
355   const int nMsg = 300;
356 
357   if( pzErrMsg ) *pzErrMsg = 0;
358 
359   /* Ticket #1863.  To avoid a creating security problems for older
360   ** applications that relink against newer versions of SQLite, the
361   ** ability to run load_extension is turned off by default.  One
362   ** must call sqlite3_enable_load_extension() to turn on extension
363   ** loading.  Otherwise you get the following error.
364   */
365   if( (db->flags & SQLITE_LoadExtension)==0 ){
366     if( pzErrMsg ){
367       *pzErrMsg = sqlite3_mprintf("not authorized");
368     }
369     return SQLITE_ERROR;
370   }
371 
372   if( zProc==0 ){
373     zProc = "sqlite3_extension_init";
374   }
375 
376   handle = sqlite3OsDlOpen(pVfs, zFile);
377   if( handle==0 ){
378     if( pzErrMsg ){
379       *pzErrMsg = zErrmsg = sqlite3_malloc(nMsg);
380       if( zErrmsg ){
381         sqlite3_snprintf(nMsg, zErrmsg,
382             "unable to open shared library [%s]", zFile);
383         sqlite3OsDlError(pVfs, nMsg-1, zErrmsg);
384       }
385     }
386     return SQLITE_ERROR;
387   }
388   xInit = (int(*)(sqlite3*,char**,const sqlite3_api_routines*))
389                    sqlite3OsDlSym(pVfs, handle, zProc);
390   if( xInit==0 ){
391     if( pzErrMsg ){
392       *pzErrMsg = zErrmsg = sqlite3_malloc(nMsg);
393       if( zErrmsg ){
394         sqlite3_snprintf(nMsg, zErrmsg,
395             "no entry point [%s] in shared library [%s]", zProc,zFile);
396         sqlite3OsDlError(pVfs, nMsg-1, zErrmsg);
397       }
398       sqlite3OsDlClose(pVfs, handle);
399     }
400     return SQLITE_ERROR;
401   }else if( xInit(db, &zErrmsg, &sqlite3Apis) ){
402     if( pzErrMsg ){
403       *pzErrMsg = sqlite3_mprintf("error during initialization: %s", zErrmsg);
404     }
405     sqlite3_free(zErrmsg);
406     sqlite3OsDlClose(pVfs, handle);
407     return SQLITE_ERROR;
408   }
409 
410   /* Append the new shared library handle to the db->aExtension array. */
411   aHandle = sqlite3DbMallocZero(db, sizeof(handle)*(db->nExtension+1));
412   if( aHandle==0 ){
413     return SQLITE_NOMEM;
414   }
415   if( db->nExtension>0 ){
416     memcpy(aHandle, db->aExtension, sizeof(handle)*db->nExtension);
417   }
418   sqlite3DbFree(db, db->aExtension);
419   db->aExtension = aHandle;
420 
421   db->aExtension[db->nExtension++] = handle;
422   return SQLITE_OK;
423 }
424 int sqlite3_load_extension(
425   sqlite3 *db,          /* Load the extension into this database connection */
426   const char *zFile,    /* Name of the shared library containing extension */
427   const char *zProc,    /* Entry point.  Use "sqlite3_extension_init" if 0 */
428   char **pzErrMsg       /* Put error message here if not 0 */
429 ){
430   int rc;
431   sqlite3_mutex_enter(db->mutex);
432   rc = sqlite3LoadExtension(db, zFile, zProc, pzErrMsg);
433   rc = sqlite3ApiExit(db, rc);
434   sqlite3_mutex_leave(db->mutex);
435   return rc;
436 }
437 
438 /*
439 ** Call this routine when the database connection is closing in order
440 ** to clean up loaded extensions
441 */
442 void sqlite3CloseExtensions(sqlite3 *db){
443   int i;
444   assert( sqlite3_mutex_held(db->mutex) );
445   for(i=0; i<db->nExtension; i++){
446     sqlite3OsDlClose(db->pVfs, db->aExtension[i]);
447   }
448   sqlite3DbFree(db, db->aExtension);
449 }
450 
451 /*
452 ** Enable or disable extension loading.  Extension loading is disabled by
453 ** default so as not to open security holes in older applications.
454 */
455 int sqlite3_enable_load_extension(sqlite3 *db, int onoff){
456   sqlite3_mutex_enter(db->mutex);
457   if( onoff ){
458     db->flags |= SQLITE_LoadExtension;
459   }else{
460     db->flags &= ~SQLITE_LoadExtension;
461   }
462   sqlite3_mutex_leave(db->mutex);
463   return SQLITE_OK;
464 }
465 
466 #endif /* SQLITE_OMIT_LOAD_EXTENSION */
467 
468 /*
469 ** The auto-extension code added regardless of whether or not extension
470 ** loading is supported.  We need a dummy sqlite3Apis pointer for that
471 ** code if regular extension loading is not available.  This is that
472 ** dummy pointer.
473 */
474 #ifdef SQLITE_OMIT_LOAD_EXTENSION
475 static const sqlite3_api_routines sqlite3Apis = { 0 };
476 #endif
477 
478 
479 /*
480 ** The following object holds the list of automatically loaded
481 ** extensions.
482 **
483 ** This list is shared across threads.  The SQLITE_MUTEX_STATIC_MASTER
484 ** mutex must be held while accessing this list.
485 */
486 typedef struct sqlite3AutoExtList sqlite3AutoExtList;
487 static SQLITE_WSD struct sqlite3AutoExtList {
488   int nExt;              /* Number of entries in aExt[] */
489   void (**aExt)(void);   /* Pointers to the extension init functions */
490 } sqlite3Autoext = { 0, 0 };
491 
492 /* The "wsdAutoext" macro will resolve to the autoextension
493 ** state vector.  If writable static data is unsupported on the target,
494 ** we have to locate the state vector at run-time.  In the more common
495 ** case where writable static data is supported, wsdStat can refer directly
496 ** to the "sqlite3Autoext" state vector declared above.
497 */
498 #ifdef SQLITE_OMIT_WSD
499 # define wsdAutoextInit \
500   sqlite3AutoExtList *x = &GLOBAL(sqlite3AutoExtList,sqlite3Autoext)
501 # define wsdAutoext x[0]
502 #else
503 # define wsdAutoextInit
504 # define wsdAutoext sqlite3Autoext
505 #endif
506 
507 
508 /*
509 ** Register a statically linked extension that is automatically
510 ** loaded by every new database connection.
511 */
512 int sqlite3_auto_extension(void (*xInit)(void)){
513   int rc = SQLITE_OK;
514 #ifndef SQLITE_OMIT_AUTOINIT
515   rc = sqlite3_initialize();
516   if( rc ){
517     return rc;
518   }else
519 #endif
520   {
521     int i;
522 #if SQLITE_THREADSAFE
523     sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
524 #endif
525     wsdAutoextInit;
526     sqlite3_mutex_enter(mutex);
527     for(i=0; i<wsdAutoext.nExt; i++){
528       if( wsdAutoext.aExt[i]==xInit ) break;
529     }
530     if( i==wsdAutoext.nExt ){
531       int nByte = (wsdAutoext.nExt+1)*sizeof(wsdAutoext.aExt[0]);
532       void (**aNew)(void);
533       aNew = sqlite3_realloc(wsdAutoext.aExt, nByte);
534       if( aNew==0 ){
535         rc = SQLITE_NOMEM;
536       }else{
537         wsdAutoext.aExt = aNew;
538         wsdAutoext.aExt[wsdAutoext.nExt] = xInit;
539         wsdAutoext.nExt++;
540       }
541     }
542     sqlite3_mutex_leave(mutex);
543     assert( (rc&0xff)==rc );
544     return rc;
545   }
546 }
547 
548 /*
549 ** Reset the automatic extension loading mechanism.
550 */
551 void sqlite3_reset_auto_extension(void){
552 #ifndef SQLITE_OMIT_AUTOINIT
553   if( sqlite3_initialize()==SQLITE_OK )
554 #endif
555   {
556 #if SQLITE_THREADSAFE
557     sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
558 #endif
559     wsdAutoextInit;
560     sqlite3_mutex_enter(mutex);
561     sqlite3_free(wsdAutoext.aExt);
562     wsdAutoext.aExt = 0;
563     wsdAutoext.nExt = 0;
564     sqlite3_mutex_leave(mutex);
565   }
566 }
567 
568 /*
569 ** Load all automatic extensions.
570 **
571 ** If anything goes wrong, set an error in the database connection.
572 */
573 void sqlite3AutoLoadExtensions(sqlite3 *db){
574   int i;
575   int go = 1;
576   int (*xInit)(sqlite3*,char**,const sqlite3_api_routines*);
577 
578   wsdAutoextInit;
579   if( wsdAutoext.nExt==0 ){
580     /* Common case: early out without every having to acquire a mutex */
581     return;
582   }
583   for(i=0; go; i++){
584     char *zErrmsg;
585 #if SQLITE_THREADSAFE
586     sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
587 #endif
588     sqlite3_mutex_enter(mutex);
589     if( i>=wsdAutoext.nExt ){
590       xInit = 0;
591       go = 0;
592     }else{
593       xInit = (int(*)(sqlite3*,char**,const sqlite3_api_routines*))
594               wsdAutoext.aExt[i];
595     }
596     sqlite3_mutex_leave(mutex);
597     zErrmsg = 0;
598     if( xInit && xInit(db, &zErrmsg, &sqlite3Apis) ){
599       sqlite3Error(db, SQLITE_ERROR,
600             "automatic extension loading failed: %s", zErrmsg);
601       go = 0;
602     }
603     sqlite3_free(zErrmsg);
604   }
605 }
606