xref: /sqlite-3.40.0/src/loadext.c (revision 3d403c71)
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_DECLTYPE
75 # define sqlite3_column_decltype16      0
76 # define sqlite3_column_decltype        0
77 #endif
78 
79 #ifdef SQLITE_OMIT_PROGRESS_CALLBACK
80 # define sqlite3_progress_handler 0
81 #endif
82 
83 #ifdef SQLITE_OMIT_VIRTUALTABLE
84 # define sqlite3_create_module 0
85 # define sqlite3_create_module_v2 0
86 # define sqlite3_declare_vtab 0
87 # define sqlite3_vtab_config 0
88 # define sqlite3_vtab_on_conflict 0
89 #endif
90 
91 #ifdef SQLITE_OMIT_SHARED_CACHE
92 # define sqlite3_enable_shared_cache 0
93 #endif
94 
95 #ifdef SQLITE_OMIT_TRACE
96 # define sqlite3_profile       0
97 # define sqlite3_trace         0
98 #endif
99 
100 #ifdef SQLITE_OMIT_GET_TABLE
101 # define sqlite3_free_table    0
102 # define sqlite3_get_table     0
103 #endif
104 
105 #ifdef SQLITE_OMIT_INCRBLOB
106 #define sqlite3_bind_zeroblob  0
107 #define sqlite3_blob_bytes     0
108 #define sqlite3_blob_close     0
109 #define sqlite3_blob_open      0
110 #define sqlite3_blob_read      0
111 #define sqlite3_blob_write     0
112 #define sqlite3_blob_reopen    0
113 #endif
114 
115 /*
116 ** The following structure contains pointers to all SQLite API routines.
117 ** A pointer to this structure is passed into extensions when they are
118 ** loaded so that the extension can make calls back into the SQLite
119 ** library.
120 **
121 ** When adding new APIs, add them to the bottom of this structure
122 ** in order to preserve backwards compatibility.
123 **
124 ** Extensions that use newer APIs should first call the
125 ** sqlite3_libversion_number() to make sure that the API they
126 ** intend to use is supported by the library.  Extensions should
127 ** also check to make sure that the pointer to the function is
128 ** not NULL before calling it.
129 */
130 static const sqlite3_api_routines sqlite3Apis = {
131   sqlite3_aggregate_context,
132 #ifndef SQLITE_OMIT_DEPRECATED
133   sqlite3_aggregate_count,
134 #else
135   0,
136 #endif
137   sqlite3_bind_blob,
138   sqlite3_bind_double,
139   sqlite3_bind_int,
140   sqlite3_bind_int64,
141   sqlite3_bind_null,
142   sqlite3_bind_parameter_count,
143   sqlite3_bind_parameter_index,
144   sqlite3_bind_parameter_name,
145   sqlite3_bind_text,
146   sqlite3_bind_text16,
147   sqlite3_bind_value,
148   sqlite3_busy_handler,
149   sqlite3_busy_timeout,
150   sqlite3_changes,
151   sqlite3_close,
152   sqlite3_collation_needed,
153   sqlite3_collation_needed16,
154   sqlite3_column_blob,
155   sqlite3_column_bytes,
156   sqlite3_column_bytes16,
157   sqlite3_column_count,
158   sqlite3_column_database_name,
159   sqlite3_column_database_name16,
160   sqlite3_column_decltype,
161   sqlite3_column_decltype16,
162   sqlite3_column_double,
163   sqlite3_column_int,
164   sqlite3_column_int64,
165   sqlite3_column_name,
166   sqlite3_column_name16,
167   sqlite3_column_origin_name,
168   sqlite3_column_origin_name16,
169   sqlite3_column_table_name,
170   sqlite3_column_table_name16,
171   sqlite3_column_text,
172   sqlite3_column_text16,
173   sqlite3_column_type,
174   sqlite3_column_value,
175   sqlite3_commit_hook,
176   sqlite3_complete,
177   sqlite3_complete16,
178   sqlite3_create_collation,
179   sqlite3_create_collation16,
180   sqlite3_create_function,
181   sqlite3_create_function16,
182   sqlite3_create_module,
183   sqlite3_data_count,
184   sqlite3_db_handle,
185   sqlite3_declare_vtab,
186   sqlite3_enable_shared_cache,
187   sqlite3_errcode,
188   sqlite3_errmsg,
189   sqlite3_errmsg16,
190   sqlite3_exec,
191 #ifndef SQLITE_OMIT_DEPRECATED
192   sqlite3_expired,
193 #else
194   0,
195 #endif
196   sqlite3_finalize,
197   sqlite3_free,
198   sqlite3_free_table,
199   sqlite3_get_autocommit,
200   sqlite3_get_auxdata,
201   sqlite3_get_table,
202   0,     /* Was sqlite3_global_recover(), but that function is deprecated */
203   sqlite3_interrupt,
204   sqlite3_last_insert_rowid,
205   sqlite3_libversion,
206   sqlite3_libversion_number,
207   sqlite3_malloc,
208   sqlite3_mprintf,
209   sqlite3_open,
210   sqlite3_open16,
211   sqlite3_prepare,
212   sqlite3_prepare16,
213   sqlite3_profile,
214   sqlite3_progress_handler,
215   sqlite3_realloc,
216   sqlite3_reset,
217   sqlite3_result_blob,
218   sqlite3_result_double,
219   sqlite3_result_error,
220   sqlite3_result_error16,
221   sqlite3_result_int,
222   sqlite3_result_int64,
223   sqlite3_result_null,
224   sqlite3_result_text,
225   sqlite3_result_text16,
226   sqlite3_result_text16be,
227   sqlite3_result_text16le,
228   sqlite3_result_value,
229   sqlite3_rollback_hook,
230   sqlite3_set_authorizer,
231   sqlite3_set_auxdata,
232   sqlite3_snprintf,
233   sqlite3_step,
234   sqlite3_table_column_metadata,
235 #ifndef SQLITE_OMIT_DEPRECATED
236   sqlite3_thread_cleanup,
237 #else
238   0,
239 #endif
240   sqlite3_total_changes,
241   sqlite3_trace,
242 #ifndef SQLITE_OMIT_DEPRECATED
243   sqlite3_transfer_bindings,
244 #else
245   0,
246 #endif
247   sqlite3_update_hook,
248   sqlite3_user_data,
249   sqlite3_value_blob,
250   sqlite3_value_bytes,
251   sqlite3_value_bytes16,
252   sqlite3_value_double,
253   sqlite3_value_int,
254   sqlite3_value_int64,
255   sqlite3_value_numeric_type,
256   sqlite3_value_text,
257   sqlite3_value_text16,
258   sqlite3_value_text16be,
259   sqlite3_value_text16le,
260   sqlite3_value_type,
261   sqlite3_vmprintf,
262   /*
263   ** The original API set ends here.  All extensions can call any
264   ** of the APIs above provided that the pointer is not NULL.  But
265   ** before calling APIs that follow, extension should check the
266   ** sqlite3_libversion_number() to make sure they are dealing with
267   ** a library that is new enough to support that API.
268   *************************************************************************
269   */
270   sqlite3_overload_function,
271 
272   /*
273   ** Added after 3.3.13
274   */
275   sqlite3_prepare_v2,
276   sqlite3_prepare16_v2,
277   sqlite3_clear_bindings,
278 
279   /*
280   ** Added for 3.4.1
281   */
282   sqlite3_create_module_v2,
283 
284   /*
285   ** Added for 3.5.0
286   */
287   sqlite3_bind_zeroblob,
288   sqlite3_blob_bytes,
289   sqlite3_blob_close,
290   sqlite3_blob_open,
291   sqlite3_blob_read,
292   sqlite3_blob_write,
293   sqlite3_create_collation_v2,
294   sqlite3_file_control,
295   sqlite3_memory_highwater,
296   sqlite3_memory_used,
297 #ifdef SQLITE_MUTEX_OMIT
298   0,
299   0,
300   0,
301   0,
302   0,
303 #else
304   sqlite3_mutex_alloc,
305   sqlite3_mutex_enter,
306   sqlite3_mutex_free,
307   sqlite3_mutex_leave,
308   sqlite3_mutex_try,
309 #endif
310   sqlite3_open_v2,
311   sqlite3_release_memory,
312   sqlite3_result_error_nomem,
313   sqlite3_result_error_toobig,
314   sqlite3_sleep,
315   sqlite3_soft_heap_limit,
316   sqlite3_vfs_find,
317   sqlite3_vfs_register,
318   sqlite3_vfs_unregister,
319 
320   /*
321   ** Added for 3.5.8
322   */
323   sqlite3_threadsafe,
324   sqlite3_result_zeroblob,
325   sqlite3_result_error_code,
326   sqlite3_test_control,
327   sqlite3_randomness,
328   sqlite3_context_db_handle,
329 
330   /*
331   ** Added for 3.6.0
332   */
333   sqlite3_extended_result_codes,
334   sqlite3_limit,
335   sqlite3_next_stmt,
336   sqlite3_sql,
337   sqlite3_status,
338 
339   /*
340   ** Added for 3.7.4
341   */
342   sqlite3_backup_finish,
343   sqlite3_backup_init,
344   sqlite3_backup_pagecount,
345   sqlite3_backup_remaining,
346   sqlite3_backup_step,
347 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
348   sqlite3_compileoption_get,
349   sqlite3_compileoption_used,
350 #else
351   0,
352   0,
353 #endif
354   sqlite3_create_function_v2,
355   sqlite3_db_config,
356   sqlite3_db_mutex,
357   sqlite3_db_status,
358   sqlite3_extended_errcode,
359   sqlite3_log,
360   sqlite3_soft_heap_limit64,
361   sqlite3_sourceid,
362   sqlite3_stmt_status,
363   sqlite3_strnicmp,
364 #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
365   sqlite3_unlock_notify,
366 #else
367   0,
368 #endif
369 #ifndef SQLITE_OMIT_WAL
370   sqlite3_wal_autocheckpoint,
371   sqlite3_wal_checkpoint,
372   sqlite3_wal_hook,
373 #else
374   0,
375   0,
376   0,
377 #endif
378   sqlite3_blob_reopen,
379   sqlite3_vtab_config,
380   sqlite3_vtab_on_conflict,
381 };
382 
383 /*
384 ** Attempt to load an SQLite extension library contained in the file
385 ** zFile.  The entry point is zProc.  zProc may be 0 in which case a
386 ** default entry point name (sqlite3_extension_init) is used.  Use
387 ** of the default name is recommended.
388 **
389 ** Return SQLITE_OK on success and SQLITE_ERROR if something goes wrong.
390 **
391 ** If an error occurs and pzErrMsg is not 0, then fill *pzErrMsg with
392 ** error message text.  The calling function should free this memory
393 ** by calling sqlite3DbFree(db, ).
394 */
395 static int sqlite3LoadExtension(
396   sqlite3 *db,          /* Load the extension into this database connection */
397   const char *zFile,    /* Name of the shared library containing extension */
398   const char *zProc,    /* Entry point.  Use "sqlite3_extension_init" if 0 */
399   char **pzErrMsg       /* Put error message here if not 0 */
400 ){
401   sqlite3_vfs *pVfs = db->pVfs;
402   void *handle;
403   int (*xInit)(sqlite3*,char**,const sqlite3_api_routines*);
404   char *zErrmsg = 0;
405   void **aHandle;
406   int nMsg = 300 + sqlite3Strlen30(zFile);
407 
408   if( pzErrMsg ) *pzErrMsg = 0;
409 
410   /* Ticket #1863.  To avoid a creating security problems for older
411   ** applications that relink against newer versions of SQLite, the
412   ** ability to run load_extension is turned off by default.  One
413   ** must call sqlite3_enable_load_extension() to turn on extension
414   ** loading.  Otherwise you get the following error.
415   */
416   if( (db->flags & SQLITE_LoadExtension)==0 ){
417     if( pzErrMsg ){
418       *pzErrMsg = sqlite3_mprintf("not authorized");
419     }
420     return SQLITE_ERROR;
421   }
422 
423   if( zProc==0 ){
424     zProc = "sqlite3_extension_init";
425   }
426 
427   handle = sqlite3OsDlOpen(pVfs, zFile);
428   if( handle==0 ){
429     if( pzErrMsg ){
430       *pzErrMsg = zErrmsg = sqlite3_malloc(nMsg);
431       if( zErrmsg ){
432         sqlite3_snprintf(nMsg, zErrmsg,
433             "unable to open shared library [%s]", zFile);
434         sqlite3OsDlError(pVfs, nMsg-1, zErrmsg);
435       }
436     }
437     return SQLITE_ERROR;
438   }
439   xInit = (int(*)(sqlite3*,char**,const sqlite3_api_routines*))
440                    sqlite3OsDlSym(pVfs, handle, zProc);
441   if( xInit==0 ){
442     if( pzErrMsg ){
443       nMsg += sqlite3Strlen30(zProc);
444       *pzErrMsg = zErrmsg = sqlite3_malloc(nMsg);
445       if( zErrmsg ){
446         sqlite3_snprintf(nMsg, zErrmsg,
447             "no entry point [%s] in shared library [%s]", zProc,zFile);
448         sqlite3OsDlError(pVfs, nMsg-1, zErrmsg);
449       }
450       sqlite3OsDlClose(pVfs, handle);
451     }
452     return SQLITE_ERROR;
453   }else if( xInit(db, &zErrmsg, &sqlite3Apis) ){
454     if( pzErrMsg ){
455       *pzErrMsg = sqlite3_mprintf("error during initialization: %s", zErrmsg);
456     }
457     sqlite3_free(zErrmsg);
458     sqlite3OsDlClose(pVfs, handle);
459     return SQLITE_ERROR;
460   }
461 
462   /* Append the new shared library handle to the db->aExtension array. */
463   aHandle = sqlite3DbMallocZero(db, sizeof(handle)*(db->nExtension+1));
464   if( aHandle==0 ){
465     return SQLITE_NOMEM;
466   }
467   if( db->nExtension>0 ){
468     memcpy(aHandle, db->aExtension, sizeof(handle)*db->nExtension);
469   }
470   sqlite3DbFree(db, db->aExtension);
471   db->aExtension = aHandle;
472 
473   db->aExtension[db->nExtension++] = handle;
474   return SQLITE_OK;
475 }
476 int sqlite3_load_extension(
477   sqlite3 *db,          /* Load the extension into this database connection */
478   const char *zFile,    /* Name of the shared library containing extension */
479   const char *zProc,    /* Entry point.  Use "sqlite3_extension_init" if 0 */
480   char **pzErrMsg       /* Put error message here if not 0 */
481 ){
482   int rc;
483   sqlite3_mutex_enter(db->mutex);
484   rc = sqlite3LoadExtension(db, zFile, zProc, pzErrMsg);
485   rc = sqlite3ApiExit(db, rc);
486   sqlite3_mutex_leave(db->mutex);
487   return rc;
488 }
489 
490 /*
491 ** Call this routine when the database connection is closing in order
492 ** to clean up loaded extensions
493 */
494 void sqlite3CloseExtensions(sqlite3 *db){
495   int i;
496   assert( sqlite3_mutex_held(db->mutex) );
497   for(i=0; i<db->nExtension; i++){
498     sqlite3OsDlClose(db->pVfs, db->aExtension[i]);
499   }
500   sqlite3DbFree(db, db->aExtension);
501 }
502 
503 /*
504 ** Enable or disable extension loading.  Extension loading is disabled by
505 ** default so as not to open security holes in older applications.
506 */
507 int sqlite3_enable_load_extension(sqlite3 *db, int onoff){
508   sqlite3_mutex_enter(db->mutex);
509   if( onoff ){
510     db->flags |= SQLITE_LoadExtension;
511   }else{
512     db->flags &= ~SQLITE_LoadExtension;
513   }
514   sqlite3_mutex_leave(db->mutex);
515   return SQLITE_OK;
516 }
517 
518 #endif /* SQLITE_OMIT_LOAD_EXTENSION */
519 
520 /*
521 ** The auto-extension code added regardless of whether or not extension
522 ** loading is supported.  We need a dummy sqlite3Apis pointer for that
523 ** code if regular extension loading is not available.  This is that
524 ** dummy pointer.
525 */
526 #ifdef SQLITE_OMIT_LOAD_EXTENSION
527 static const sqlite3_api_routines sqlite3Apis = { 0 };
528 #endif
529 
530 
531 /*
532 ** The following object holds the list of automatically loaded
533 ** extensions.
534 **
535 ** This list is shared across threads.  The SQLITE_MUTEX_STATIC_MASTER
536 ** mutex must be held while accessing this list.
537 */
538 typedef struct sqlite3AutoExtList sqlite3AutoExtList;
539 static SQLITE_WSD struct sqlite3AutoExtList {
540   int nExt;              /* Number of entries in aExt[] */
541   void (**aExt)(void);   /* Pointers to the extension init functions */
542 } sqlite3Autoext = { 0, 0 };
543 
544 /* The "wsdAutoext" macro will resolve to the autoextension
545 ** state vector.  If writable static data is unsupported on the target,
546 ** we have to locate the state vector at run-time.  In the more common
547 ** case where writable static data is supported, wsdStat can refer directly
548 ** to the "sqlite3Autoext" state vector declared above.
549 */
550 #ifdef SQLITE_OMIT_WSD
551 # define wsdAutoextInit \
552   sqlite3AutoExtList *x = &GLOBAL(sqlite3AutoExtList,sqlite3Autoext)
553 # define wsdAutoext x[0]
554 #else
555 # define wsdAutoextInit
556 # define wsdAutoext sqlite3Autoext
557 #endif
558 
559 
560 /*
561 ** Register a statically linked extension that is automatically
562 ** loaded by every new database connection.
563 */
564 int sqlite3_auto_extension(void (*xInit)(void)){
565   int rc = SQLITE_OK;
566 #ifndef SQLITE_OMIT_AUTOINIT
567   rc = sqlite3_initialize();
568   if( rc ){
569     return rc;
570   }else
571 #endif
572   {
573     int i;
574 #if SQLITE_THREADSAFE
575     sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
576 #endif
577     wsdAutoextInit;
578     sqlite3_mutex_enter(mutex);
579     for(i=0; i<wsdAutoext.nExt; i++){
580       if( wsdAutoext.aExt[i]==xInit ) break;
581     }
582     if( i==wsdAutoext.nExt ){
583       int nByte = (wsdAutoext.nExt+1)*sizeof(wsdAutoext.aExt[0]);
584       void (**aNew)(void);
585       aNew = sqlite3_realloc(wsdAutoext.aExt, nByte);
586       if( aNew==0 ){
587         rc = SQLITE_NOMEM;
588       }else{
589         wsdAutoext.aExt = aNew;
590         wsdAutoext.aExt[wsdAutoext.nExt] = xInit;
591         wsdAutoext.nExt++;
592       }
593     }
594     sqlite3_mutex_leave(mutex);
595     assert( (rc&0xff)==rc );
596     return rc;
597   }
598 }
599 
600 /*
601 ** Reset the automatic extension loading mechanism.
602 */
603 void sqlite3_reset_auto_extension(void){
604 #ifndef SQLITE_OMIT_AUTOINIT
605   if( sqlite3_initialize()==SQLITE_OK )
606 #endif
607   {
608 #if SQLITE_THREADSAFE
609     sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
610 #endif
611     wsdAutoextInit;
612     sqlite3_mutex_enter(mutex);
613     sqlite3_free(wsdAutoext.aExt);
614     wsdAutoext.aExt = 0;
615     wsdAutoext.nExt = 0;
616     sqlite3_mutex_leave(mutex);
617   }
618 }
619 
620 /*
621 ** Load all automatic extensions.
622 **
623 ** If anything goes wrong, set an error in the database connection.
624 */
625 void sqlite3AutoLoadExtensions(sqlite3 *db){
626   int i;
627   int go = 1;
628   int rc;
629   int (*xInit)(sqlite3*,char**,const sqlite3_api_routines*);
630 
631   wsdAutoextInit;
632   if( wsdAutoext.nExt==0 ){
633     /* Common case: early out without every having to acquire a mutex */
634     return;
635   }
636   for(i=0; go; i++){
637     char *zErrmsg;
638 #if SQLITE_THREADSAFE
639     sqlite3_mutex *mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
640 #endif
641     sqlite3_mutex_enter(mutex);
642     if( i>=wsdAutoext.nExt ){
643       xInit = 0;
644       go = 0;
645     }else{
646       xInit = (int(*)(sqlite3*,char**,const sqlite3_api_routines*))
647               wsdAutoext.aExt[i];
648     }
649     sqlite3_mutex_leave(mutex);
650     zErrmsg = 0;
651     if( xInit && (rc = xInit(db, &zErrmsg, &sqlite3Apis))!=0 ){
652       sqlite3Error(db, rc,
653             "automatic extension loading failed: %s", zErrmsg);
654       go = 0;
655     }
656     sqlite3_free(zErrmsg);
657   }
658 }
659