xref: /sqlite-3.40.0/src/loadext.c (revision cd7274ce)
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 #ifndef SQLITE_OMIT_LOAD_EXTENSION
16 
17 #define SQLITE_CORE 1  /* Disable the API redefinition in sqlite3ext.h */
18 #include "sqlite3ext.h"
19 #include "sqliteInt.h"
20 #include <string.h>
21 #include <ctype.h>
22 
23 /*
24 ** Some API routines are omitted when various features are
25 ** excluded from a build of SQLite.  Substitute a NULL pointer
26 ** for any missing APIs.
27 */
28 #ifndef SQLITE_ENABLE_COLUMN_METADATA
29 # define sqlite3_column_database_name   0
30 # define sqlite3_column_database_name16 0
31 # define sqlite3_column_table_name      0
32 # define sqlite3_column_table_name16    0
33 # define sqlite3_column_origin_name     0
34 # define sqlite3_column_origin_name16   0
35 # define sqlite3_table_column_metadata  0
36 #endif
37 
38 #ifdef SQLITE_OMIT_AUTHORIZATION
39 # define sqlite3_set_authorizer         0
40 #endif
41 
42 #ifdef SQLITE_OMIT_UTF16
43 # define sqlite3_bind_text16            0
44 # define sqlite3_collation_needed16     0
45 # define sqlite3_column_decltype16      0
46 # define sqlite3_column_name16          0
47 # define sqlite3_column_text16          0
48 # define sqlite3_complete16             0
49 # define sqlite3_create_collation16     0
50 # define sqlite3_create_function16      0
51 # define sqlite3_errmsg16               0
52 # define sqlite3_open16                 0
53 # define sqlite3_prepare16              0
54 # define sqlite3_prepare16_v2           0
55 # define sqlite3_result_error16         0
56 # define sqlite3_result_text16          0
57 # define sqlite3_result_text16be        0
58 # define sqlite3_result_text16le        0
59 # define sqlite3_value_text16           0
60 # define sqlite3_value_text16be         0
61 # define sqlite3_value_text16le         0
62 # define sqlite3_column_database_name16 0
63 # define sqlite3_column_table_name16    0
64 # define sqlite3_column_origin_name16   0
65 #endif
66 
67 #ifdef SQLITE_OMIT_COMPLETE
68 # define sqlite3_complete 0
69 # define sqlite3_complete16 0
70 #endif
71 
72 #ifdef SQLITE_OMIT_PROGRESS_CALLBACK
73 # define sqlite3_progress_handler 0
74 #endif
75 
76 #ifdef SQLITE_OMIT_VIRTUALTABLE
77 # define sqlite3_create_module 0
78 # define sqlite3_create_module_v2 0
79 # define sqlite3_declare_vtab 0
80 #endif
81 
82 #ifdef SQLITE_OMIT_SHARED_CACHE
83 # define sqlite3_enable_shared_cache 0
84 #endif
85 
86 #ifdef SQLITE_OMIT_TRACE
87 # define sqlite3_profile       0
88 # define sqlite3_trace         0
89 #endif
90 
91 #ifdef SQLITE_OMIT_GET_TABLE
92 # define sqlite3_free_table    0
93 # define sqlite3_get_table     0
94 #endif
95 
96 #ifdef SQLITE_OMIT_INCRBLOB
97 #define sqlite3_bind_zeroblob  0
98 #define sqlite3_blob_bytes     0
99 #define sqlite3_blob_close     0
100 #define sqlite3_blob_open      0
101 #define sqlite3_blob_read      0
102 #define sqlite3_blob_write     0
103 #endif
104 
105 /*
106 ** The following structure contains pointers to all SQLite API routines.
107 ** A pointer to this structure is passed into extensions when they are
108 ** loaded so that the extension can make calls back into the SQLite
109 ** library.
110 **
111 ** When adding new APIs, add them to the bottom of this structure
112 ** in order to preserve backwards compatibility.
113 **
114 ** Extensions that use newer APIs should first call the
115 ** sqlite3_libversion_number() to make sure that the API they
116 ** intend to use is supported by the library.  Extensions should
117 ** also check to make sure that the pointer to the function is
118 ** not NULL before calling it.
119 */
120 const sqlite3_api_routines sqlite3_apis = {
121   sqlite3_aggregate_context,
122   sqlite3_aggregate_count,
123   sqlite3_bind_blob,
124   sqlite3_bind_double,
125   sqlite3_bind_int,
126   sqlite3_bind_int64,
127   sqlite3_bind_null,
128   sqlite3_bind_parameter_count,
129   sqlite3_bind_parameter_index,
130   sqlite3_bind_parameter_name,
131   sqlite3_bind_text,
132   sqlite3_bind_text16,
133   sqlite3_bind_value,
134   sqlite3_busy_handler,
135   sqlite3_busy_timeout,
136   sqlite3_changes,
137   sqlite3_close,
138   sqlite3_collation_needed,
139   sqlite3_collation_needed16,
140   sqlite3_column_blob,
141   sqlite3_column_bytes,
142   sqlite3_column_bytes16,
143   sqlite3_column_count,
144   sqlite3_column_database_name,
145   sqlite3_column_database_name16,
146   sqlite3_column_decltype,
147   sqlite3_column_decltype16,
148   sqlite3_column_double,
149   sqlite3_column_int,
150   sqlite3_column_int64,
151   sqlite3_column_name,
152   sqlite3_column_name16,
153   sqlite3_column_origin_name,
154   sqlite3_column_origin_name16,
155   sqlite3_column_table_name,
156   sqlite3_column_table_name16,
157   sqlite3_column_text,
158   sqlite3_column_text16,
159   sqlite3_column_type,
160   sqlite3_column_value,
161   sqlite3_commit_hook,
162   sqlite3_complete,
163   sqlite3_complete16,
164   sqlite3_create_collation,
165   sqlite3_create_collation16,
166   sqlite3_create_function,
167   sqlite3_create_function16,
168   sqlite3_create_module,
169   sqlite3_data_count,
170   sqlite3_db_handle,
171   sqlite3_declare_vtab,
172   sqlite3_enable_shared_cache,
173   sqlite3_errcode,
174   sqlite3_errmsg,
175   sqlite3_errmsg16,
176   sqlite3_exec,
177   sqlite3_expired,
178   sqlite3_finalize,
179   sqlite3_free,
180   sqlite3_free_table,
181   sqlite3_get_autocommit,
182   sqlite3_get_auxdata,
183   sqlite3_get_table,
184   0,     /* Was sqlite3_global_recover(), but that function is deprecated */
185   sqlite3_interrupt,
186   sqlite3_last_insert_rowid,
187   sqlite3_libversion,
188   sqlite3_libversion_number,
189   sqlite3_malloc,
190   sqlite3_mprintf,
191   sqlite3_open,
192   sqlite3_open16,
193   sqlite3_prepare,
194   sqlite3_prepare16,
195   sqlite3_profile,
196   sqlite3_progress_handler,
197   sqlite3_realloc,
198   sqlite3_reset,
199   sqlite3_result_blob,
200   sqlite3_result_double,
201   sqlite3_result_error,
202   sqlite3_result_error16,
203   sqlite3_result_int,
204   sqlite3_result_int64,
205   sqlite3_result_null,
206   sqlite3_result_text,
207   sqlite3_result_text16,
208   sqlite3_result_text16be,
209   sqlite3_result_text16le,
210   sqlite3_result_value,
211   sqlite3_rollback_hook,
212   sqlite3_set_authorizer,
213   sqlite3_set_auxdata,
214   sqlite3_snprintf,
215   sqlite3_step,
216   sqlite3_table_column_metadata,
217   sqlite3_thread_cleanup,
218   sqlite3_total_changes,
219   sqlite3_trace,
220   sqlite3_transfer_bindings,
221   sqlite3_update_hook,
222   sqlite3_user_data,
223   sqlite3_value_blob,
224   sqlite3_value_bytes,
225   sqlite3_value_bytes16,
226   sqlite3_value_double,
227   sqlite3_value_int,
228   sqlite3_value_int64,
229   sqlite3_value_numeric_type,
230   sqlite3_value_text,
231   sqlite3_value_text16,
232   sqlite3_value_text16be,
233   sqlite3_value_text16le,
234   sqlite3_value_type,
235   sqlite3_vmprintf,
236   /*
237   ** The original API set ends here.  All extensions can call any
238   ** of the APIs above provided that the pointer is not NULL.  But
239   ** before calling APIs that follow, extension should check the
240   ** sqlite3_libversion_number() to make sure they are dealing with
241   ** a library that is new enough to support that API.
242   *************************************************************************
243   */
244   sqlite3_overload_function,
245 
246   /*
247   ** Added after 3.3.13
248   */
249   sqlite3_prepare_v2,
250   sqlite3_prepare16_v2,
251   sqlite3_clear_bindings,
252 
253   /*
254   ** Added for 3.4.1
255   */
256   sqlite3_create_module_v2,
257 
258   /*
259   ** Added for 3.5.0
260   */
261   sqlite3_bind_zeroblob,
262   sqlite3_blob_bytes,
263   sqlite3_blob_close,
264   sqlite3_blob_open,
265   sqlite3_blob_read,
266   sqlite3_blob_write,
267   sqlite3_create_collation_v2,
268   sqlite3_file_control,
269   sqlite3_memory_highwater,
270   sqlite3_memory_used,
271 #ifdef SQLITE_MUTEX_NOOP
272   0,
273   0,
274   0,
275   0,
276   0,
277 #else
278   sqlite3_mutex_alloc,
279   sqlite3_mutex_enter,
280   sqlite3_mutex_free,
281   sqlite3_mutex_leave,
282   sqlite3_mutex_try,
283 #endif
284   sqlite3_open_v2,
285   sqlite3_release_memory,
286   sqlite3_result_error_nomem,
287   sqlite3_result_error_toobig,
288   sqlite3_sleep,
289   sqlite3_soft_heap_limit,
290   sqlite3_vfs_find,
291   sqlite3_vfs_register,
292   sqlite3_vfs_unregister,
293 };
294 
295 /*
296 ** Attempt to load an SQLite extension library contained in the file
297 ** zFile.  The entry point is zProc.  zProc may be 0 in which case a
298 ** default entry point name (sqlite3_extension_init) is used.  Use
299 ** of the default name is recommended.
300 **
301 ** Return SQLITE_OK on success and SQLITE_ERROR if something goes wrong.
302 **
303 ** If an error occurs and pzErrMsg is not 0, then fill *pzErrMsg with
304 ** error message text.  The calling function should free this memory
305 ** by calling sqlite3_free().
306 */
307 static int sqlite3LoadExtension(
308   sqlite3 *db,          /* Load the extension into this database connection */
309   const char *zFile,    /* Name of the shared library containing extension */
310   const char *zProc,    /* Entry point.  Use "sqlite3_extension_init" if 0 */
311   char **pzErrMsg       /* Put error message here if not 0 */
312 ){
313   sqlite3_vfs *pVfs = db->pVfs;
314   void *handle;
315   int (*xInit)(sqlite3*,char**,const sqlite3_api_routines*);
316   char *zErrmsg = 0;
317   void **aHandle;
318 
319   /* Ticket #1863.  To avoid a creating security problems for older
320   ** applications that relink against newer versions of SQLite, the
321   ** ability to run load_extension is turned off by default.  One
322   ** must call sqlite3_enable_load_extension() to turn on extension
323   ** loading.  Otherwise you get the following error.
324   */
325   if( (db->flags & SQLITE_LoadExtension)==0 ){
326     if( pzErrMsg ){
327       *pzErrMsg = sqlite3_mprintf("not authorized");
328     }
329     return SQLITE_ERROR;
330   }
331 
332   if( zProc==0 ){
333     zProc = "sqlite3_extension_init";
334   }
335 
336   handle = sqlite3OsDlOpen(pVfs, zFile);
337   if( handle==0 ){
338     if( pzErrMsg ){
339       char zErr[256];
340       zErr[sizeof(zErr)-1] = '\0';
341       sqlite3_snprintf(sizeof(zErr)-1, zErr,
342           "unable to open shared library [%s]", zFile);
343       sqlite3OsDlError(pVfs, sizeof(zErr)-1, zErr);
344       *pzErrMsg = sqlite3DbStrDup(db, zErr);
345     }
346     return SQLITE_ERROR;
347   }
348   xInit = (int(*)(sqlite3*,char**,const sqlite3_api_routines*))
349                    sqlite3OsDlSym(pVfs, handle, zProc);
350   if( xInit==0 ){
351     if( pzErrMsg ){
352       char zErr[256];
353       zErr[sizeof(zErr)-1] = '\0';
354       sqlite3_snprintf(sizeof(zErr)-1, zErr,
355           "no entry point [%s] in shared library [%s]", zProc,zFile);
356       sqlite3OsDlError(pVfs, sizeof(zErr)-1, zErr);
357       *pzErrMsg = sqlite3DbStrDup(db, zErr);
358       sqlite3OsDlClose(pVfs, handle);
359     }
360     return SQLITE_ERROR;
361   }else if( xInit(db, &zErrmsg, &sqlite3_apis) ){
362     if( pzErrMsg ){
363       *pzErrMsg = sqlite3_mprintf("error during initialization: %s", zErrmsg);
364     }
365     sqlite3_free(zErrmsg);
366     sqlite3OsDlClose(pVfs, handle);
367     return SQLITE_ERROR;
368   }
369 
370   /* Append the new shared library handle to the db->aExtension array. */
371   db->nExtension++;
372   aHandle = sqlite3DbMallocZero(db, sizeof(handle)*db->nExtension);
373   if( aHandle==0 ){
374     return SQLITE_NOMEM;
375   }
376   if( db->nExtension>0 ){
377     memcpy(aHandle, db->aExtension, sizeof(handle)*(db->nExtension-1));
378   }
379   sqlite3_free(db->aExtension);
380   db->aExtension = aHandle;
381 
382   db->aExtension[db->nExtension-1] = handle;
383   return SQLITE_OK;
384 }
385 int sqlite3_load_extension(
386   sqlite3 *db,          /* Load the extension into this database connection */
387   const char *zFile,    /* Name of the shared library containing extension */
388   const char *zProc,    /* Entry point.  Use "sqlite3_extension_init" if 0 */
389   char **pzErrMsg       /* Put error message here if not 0 */
390 ){
391   int rc;
392   sqlite3_mutex_enter(db->mutex);
393   rc = sqlite3LoadExtension(db, zFile, zProc, pzErrMsg);
394   sqlite3_mutex_leave(db->mutex);
395   return rc;
396 }
397 
398 /*
399 ** Call this routine when the database connection is closing in order
400 ** to clean up loaded extensions
401 */
402 void sqlite3CloseExtensions(sqlite3 *db){
403   int i;
404   assert( sqlite3_mutex_held(db->mutex) );
405   for(i=0; i<db->nExtension; i++){
406     sqlite3OsDlClose(db->pVfs, db->aExtension[i]);
407   }
408   sqlite3_free(db->aExtension);
409 }
410 
411 /*
412 ** Enable or disable extension loading.  Extension loading is disabled by
413 ** default so as not to open security holes in older applications.
414 */
415 int sqlite3_enable_load_extension(sqlite3 *db, int onoff){
416   sqlite3_mutex_enter(db->mutex);
417   if( onoff ){
418     db->flags |= SQLITE_LoadExtension;
419   }else{
420     db->flags &= ~SQLITE_LoadExtension;
421   }
422   sqlite3_mutex_leave(db->mutex);
423   return SQLITE_OK;
424 }
425 
426 /*
427 ** The following object holds the list of automatically loaded
428 ** extensions.
429 **
430 ** This list is shared across threads.  The SQLITE_MUTEX_STATIC_MASTER
431 ** mutex must be held while accessing this list.
432 */
433 static struct {
434   int nExt;        /* Number of entries in aExt[] */
435   void **aExt;     /* Pointers to the extension init functions */
436 } autoext = { 0, 0 };
437 
438 
439 /*
440 ** Register a statically linked extension that is automatically
441 ** loaded by every new database connection.
442 */
443 int sqlite3_auto_extension(void *xInit){
444   int i;
445   int rc = SQLITE_OK;
446   sqlite3_mutex *mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER);
447   sqlite3_mutex_enter(mutex);
448   for(i=0; i<autoext.nExt; i++){
449     if( autoext.aExt[i]==xInit ) break;
450   }
451   if( i==autoext.nExt ){
452     int nByte = (autoext.nExt+1)*sizeof(autoext.aExt[0]);
453     void **aNew;
454     aNew = sqlite3_realloc(autoext.aExt, nByte);
455     if( aNew==0 ){
456       rc = SQLITE_NOMEM;
457     }else{
458       autoext.aExt = aNew;
459       autoext.aExt[autoext.nExt] = xInit;
460       autoext.nExt++;
461     }
462   }
463   sqlite3_mutex_leave(mutex);
464   assert( (rc&0xff)==rc );
465   return rc;
466 }
467 
468 /*
469 ** Reset the automatic extension loading mechanism.
470 */
471 void sqlite3_reset_auto_extension(void){
472   sqlite3_mutex *mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER);
473   sqlite3_mutex_enter(mutex);
474   sqlite3_free(autoext.aExt);
475   autoext.aExt = 0;
476   autoext.nExt = 0;
477   sqlite3_mutex_leave(mutex);
478 }
479 
480 /*
481 ** Load all automatic extensions.
482 */
483 int sqlite3AutoLoadExtensions(sqlite3 *db){
484   int i;
485   int go = 1;
486   int rc = SQLITE_OK;
487   int (*xInit)(sqlite3*,char**,const sqlite3_api_routines*);
488 
489   if( autoext.nExt==0 ){
490     /* Common case: early out without every having to acquire a mutex */
491     return SQLITE_OK;
492   }
493   for(i=0; go; i++){
494     char *zErrmsg = 0;
495     sqlite3_mutex *mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER);
496     sqlite3_mutex_enter(mutex);
497     if( i>=autoext.nExt ){
498       xInit = 0;
499       go = 0;
500     }else{
501       xInit = (int(*)(sqlite3*,char**,const sqlite3_api_routines*))
502               autoext.aExt[i];
503     }
504     sqlite3_mutex_leave(mutex);
505     if( xInit && xInit(db, &zErrmsg, &sqlite3_apis) ){
506       sqlite3Error(db, SQLITE_ERROR,
507             "automatic extension loading failed: %s", zErrmsg);
508       go = 0;
509       rc = SQLITE_ERROR;
510       sqlite3_free(zErrmsg);
511     }
512   }
513   return rc;
514 }
515 
516 #endif /* SQLITE_OMIT_LOAD_EXTENSION */
517