loadext.c.svn-base
上传用户:sunhongbo
上传日期:2022-01-25
资源大小:3010k
文件大小:15k
- /*
- ** 2006 June 7
- **
- ** The author disclaims copyright to this source code. In place of
- ** a legal notice, here is a blessing:
- **
- ** May you do good and not evil.
- ** May you find forgiveness for yourself and forgive others.
- ** May you share freely, never taking more than you give.
- **
- *************************************************************************
- ** This file contains code used to dynamically load extensions into
- ** the SQLite library.
- */
- #ifndef SQLITE_CORE
- #define SQLITE_CORE 1 /* Disable the API redefinition in sqlite3ext.h */
- #endif
- #include "sqlite3ext.h"
- #include "sqliteInt.h"
- #include <string.h>
- #include <ctype.h>
- #ifndef SQLITE_OMIT_LOAD_EXTENSION
- /*
- ** Some API routines are omitted when various features are
- ** excluded from a build of SQLite. Substitute a NULL pointer
- ** for any missing APIs.
- */
- #ifndef SQLITE_ENABLE_COLUMN_METADATA
- # define sqlite3_column_database_name 0
- # define sqlite3_column_database_name16 0
- # define sqlite3_column_table_name 0
- # define sqlite3_column_table_name16 0
- # define sqlite3_column_origin_name 0
- # define sqlite3_column_origin_name16 0
- # define sqlite3_table_column_metadata 0
- #endif
- #ifdef SQLITE_OMIT_AUTHORIZATION
- # define sqlite3_set_authorizer 0
- #endif
- #ifdef SQLITE_OMIT_UTF16
- # define sqlite3_bind_text16 0
- # define sqlite3_collation_needed16 0
- # define sqlite3_column_decltype16 0
- # define sqlite3_column_name16 0
- # define sqlite3_column_text16 0
- # define sqlite3_complete16 0
- # define sqlite3_create_collation16 0
- # define sqlite3_create_function16 0
- # define sqlite3_errmsg16 0
- # define sqlite3_open16 0
- # define sqlite3_prepare16 0
- # define sqlite3_prepare16_v2 0
- # define sqlite3_result_error16 0
- # define sqlite3_result_text16 0
- # define sqlite3_result_text16be 0
- # define sqlite3_result_text16le 0
- # define sqlite3_value_text16 0
- # define sqlite3_value_text16be 0
- # define sqlite3_value_text16le 0
- # define sqlite3_column_database_name16 0
- # define sqlite3_column_table_name16 0
- # define sqlite3_column_origin_name16 0
- #endif
- #ifdef SQLITE_OMIT_COMPLETE
- # define sqlite3_complete 0
- # define sqlite3_complete16 0
- #endif
- #ifdef SQLITE_OMIT_PROGRESS_CALLBACK
- # define sqlite3_progress_handler 0
- #endif
- #ifdef SQLITE_OMIT_VIRTUALTABLE
- # define sqlite3_create_module 0
- # define sqlite3_create_module_v2 0
- # define sqlite3_declare_vtab 0
- #endif
- #ifdef SQLITE_OMIT_SHARED_CACHE
- # define sqlite3_enable_shared_cache 0
- #endif
- #ifdef SQLITE_OMIT_TRACE
- # define sqlite3_profile 0
- # define sqlite3_trace 0
- #endif
- #ifdef SQLITE_OMIT_GET_TABLE
- # define sqlite3_free_table 0
- # define sqlite3_get_table 0
- #endif
- #ifdef SQLITE_OMIT_INCRBLOB
- #define sqlite3_bind_zeroblob 0
- #define sqlite3_blob_bytes 0
- #define sqlite3_blob_close 0
- #define sqlite3_blob_open 0
- #define sqlite3_blob_read 0
- #define sqlite3_blob_write 0
- #endif
- /*
- ** The following structure contains pointers to all SQLite API routines.
- ** A pointer to this structure is passed into extensions when they are
- ** loaded so that the extension can make calls back into the SQLite
- ** library.
- **
- ** When adding new APIs, add them to the bottom of this structure
- ** in order to preserve backwards compatibility.
- **
- ** Extensions that use newer APIs should first call the
- ** sqlite3_libversion_number() to make sure that the API they
- ** intend to use is supported by the library. Extensions should
- ** also check to make sure that the pointer to the function is
- ** not NULL before calling it.
- */
- static const sqlite3_api_routines sqlite3Apis = {
- sqlite3_aggregate_context,
- sqlite3_aggregate_count,
- sqlite3_bind_blob,
- sqlite3_bind_double,
- sqlite3_bind_int,
- sqlite3_bind_int64,
- sqlite3_bind_null,
- sqlite3_bind_parameter_count,
- sqlite3_bind_parameter_index,
- sqlite3_bind_parameter_name,
- sqlite3_bind_text,
- sqlite3_bind_text16,
- sqlite3_bind_value,
- sqlite3_busy_handler,
- sqlite3_busy_timeout,
- sqlite3_changes,
- sqlite3_close,
- sqlite3_collation_needed,
- sqlite3_collation_needed16,
- sqlite3_column_blob,
- sqlite3_column_bytes,
- sqlite3_column_bytes16,
- sqlite3_column_count,
- sqlite3_column_database_name,
- sqlite3_column_database_name16,
- sqlite3_column_decltype,
- sqlite3_column_decltype16,
- sqlite3_column_double,
- sqlite3_column_int,
- sqlite3_column_int64,
- sqlite3_column_name,
- sqlite3_column_name16,
- sqlite3_column_origin_name,
- sqlite3_column_origin_name16,
- sqlite3_column_table_name,
- sqlite3_column_table_name16,
- sqlite3_column_text,
- sqlite3_column_text16,
- sqlite3_column_type,
- sqlite3_column_value,
- sqlite3_commit_hook,
- sqlite3_complete,
- sqlite3_complete16,
- sqlite3_create_collation,
- sqlite3_create_collation16,
- sqlite3_create_function,
- sqlite3_create_function16,
- sqlite3_create_module,
- sqlite3_data_count,
- sqlite3_db_handle,
- sqlite3_declare_vtab,
- sqlite3_enable_shared_cache,
- sqlite3_errcode,
- sqlite3_errmsg,
- sqlite3_errmsg16,
- sqlite3_exec,
- sqlite3_expired,
- sqlite3_finalize,
- sqlite3_free,
- sqlite3_free_table,
- sqlite3_get_autocommit,
- sqlite3_get_auxdata,
- sqlite3_get_table,
- 0, /* Was sqlite3_global_recover(), but that function is deprecated */
- sqlite3_interrupt,
- sqlite3_last_insert_rowid,
- sqlite3_libversion,
- sqlite3_libversion_number,
- sqlite3_malloc,
- sqlite3_mprintf,
- sqlite3_open,
- sqlite3_open16,
- sqlite3_prepare,
- sqlite3_prepare16,
- sqlite3_profile,
- sqlite3_progress_handler,
- sqlite3_realloc,
- sqlite3_reset,
- sqlite3_result_blob,
- sqlite3_result_double,
- sqlite3_result_error,
- sqlite3_result_error16,
- sqlite3_result_int,
- sqlite3_result_int64,
- sqlite3_result_null,
- sqlite3_result_text,
- sqlite3_result_text16,
- sqlite3_result_text16be,
- sqlite3_result_text16le,
- sqlite3_result_value,
- sqlite3_rollback_hook,
- sqlite3_set_authorizer,
- sqlite3_set_auxdata,
- sqlite3_snprintf,
- sqlite3_step,
- sqlite3_table_column_metadata,
- sqlite3_thread_cleanup,
- sqlite3_total_changes,
- sqlite3_trace,
- sqlite3_transfer_bindings,
- sqlite3_update_hook,
- sqlite3_user_data,
- sqlite3_value_blob,
- sqlite3_value_bytes,
- sqlite3_value_bytes16,
- sqlite3_value_double,
- sqlite3_value_int,
- sqlite3_value_int64,
- sqlite3_value_numeric_type,
- sqlite3_value_text,
- sqlite3_value_text16,
- sqlite3_value_text16be,
- sqlite3_value_text16le,
- sqlite3_value_type,
- sqlite3_vmprintf,
- /*
- ** The original API set ends here. All extensions can call any
- ** of the APIs above provided that the pointer is not NULL. But
- ** before calling APIs that follow, extension should check the
- ** sqlite3_libversion_number() to make sure they are dealing with
- ** a library that is new enough to support that API.
- *************************************************************************
- */
- sqlite3_overload_function,
- /*
- ** Added after 3.3.13
- */
- sqlite3_prepare_v2,
- sqlite3_prepare16_v2,
- sqlite3_clear_bindings,
- /*
- ** Added for 3.4.1
- */
- sqlite3_create_module_v2,
- /*
- ** Added for 3.5.0
- */
- sqlite3_bind_zeroblob,
- sqlite3_blob_bytes,
- sqlite3_blob_close,
- sqlite3_blob_open,
- sqlite3_blob_read,
- sqlite3_blob_write,
- sqlite3_create_collation_v2,
- sqlite3_file_control,
- sqlite3_memory_highwater,
- sqlite3_memory_used,
- #ifdef SQLITE_MUTEX_NOOP
- 0,
- 0,
- 0,
- 0,
- 0,
- #else
- sqlite3_mutex_alloc,
- sqlite3_mutex_enter,
- sqlite3_mutex_free,
- sqlite3_mutex_leave,
- sqlite3_mutex_try,
- #endif
- sqlite3_open_v2,
- sqlite3_release_memory,
- sqlite3_result_error_nomem,
- sqlite3_result_error_toobig,
- sqlite3_sleep,
- sqlite3_soft_heap_limit,
- sqlite3_vfs_find,
- sqlite3_vfs_register,
- sqlite3_vfs_unregister,
- /*
- ** Added for 3.5.8
- */
- sqlite3_threadsafe,
- sqlite3_result_zeroblob,
- sqlite3_result_error_code,
- sqlite3_test_control,
- sqlite3_randomness,
- sqlite3_context_db_handle,
- };
- /*
- ** Attempt to load an SQLite extension library contained in the file
- ** zFile. The entry point is zProc. zProc may be 0 in which case a
- ** default entry point name (sqlite3_extension_init) is used. Use
- ** of the default name is recommended.
- **
- ** Return SQLITE_OK on success and SQLITE_ERROR if something goes wrong.
- **
- ** If an error occurs and pzErrMsg is not 0, then fill *pzErrMsg with
- ** error message text. The calling function should free this memory
- ** by calling sqlite3_free().
- */
- static int sqlite3LoadExtension(
- sqlite3 *db, /* Load the extension into this database connection */
- const char *zFile, /* Name of the shared library containing extension */
- const char *zProc, /* Entry point. Use "sqlite3_extension_init" if 0 */
- char **pzErrMsg /* Put error message here if not 0 */
- ){
- sqlite3_vfs *pVfs = db->pVfs;
- void *handle;
- int (*xInit)(sqlite3*,char**,const sqlite3_api_routines*);
- char *zErrmsg = 0;
- void **aHandle;
- /* Ticket #1863. To avoid a creating security problems for older
- ** applications that relink against newer versions of SQLite, the
- ** ability to run load_extension is turned off by default. One
- ** must call sqlite3_enable_load_extension() to turn on extension
- ** loading. Otherwise you get the following error.
- */
- if( (db->flags & SQLITE_LoadExtension)==0 ){
- if( pzErrMsg ){
- *pzErrMsg = sqlite3_mprintf("not authorized");
- }
- return SQLITE_ERROR;
- }
- if( zProc==0 ){
- zProc = "sqlite3_extension_init";
- }
- handle = sqlite3OsDlOpen(pVfs, zFile);
- if( handle==0 ){
- if( pzErrMsg ){
- char zErr[256];
- zErr[sizeof(zErr)-1] = ' ';
- sqlite3_snprintf(sizeof(zErr)-1, zErr,
- "unable to open shared library [%s]", zFile);
- sqlite3OsDlError(pVfs, sizeof(zErr)-1, zErr);
- *pzErrMsg = sqlite3DbStrDup(db, zErr);
- }
- return SQLITE_ERROR;
- }
- xInit = (int(*)(sqlite3*,char**,const sqlite3_api_routines*))
- sqlite3OsDlSym(pVfs, handle, zProc);
- if( xInit==0 ){
- if( pzErrMsg ){
- char zErr[256];
- zErr[sizeof(zErr)-1] = ' ';
- sqlite3_snprintf(sizeof(zErr)-1, zErr,
- "no entry point [%s] in shared library [%s]", zProc,zFile);
- sqlite3OsDlError(pVfs, sizeof(zErr)-1, zErr);
- *pzErrMsg = sqlite3DbStrDup(db, zErr);
- sqlite3OsDlClose(pVfs, handle);
- }
- return SQLITE_ERROR;
- }else if( xInit(db, &zErrmsg, &sqlite3Apis) ){
- if( pzErrMsg ){
- *pzErrMsg = sqlite3_mprintf("error during initialization: %s", zErrmsg);
- }
- sqlite3_free(zErrmsg);
- sqlite3OsDlClose(pVfs, handle);
- return SQLITE_ERROR;
- }
- /* Append the new shared library handle to the db->aExtension array. */
- db->nExtension++;
- aHandle = sqlite3DbMallocZero(db, sizeof(handle)*db->nExtension);
- if( aHandle==0 ){
- return SQLITE_NOMEM;
- }
- if( db->nExtension>0 ){
- memcpy(aHandle, db->aExtension, sizeof(handle)*(db->nExtension-1));
- }
- sqlite3_free(db->aExtension);
- db->aExtension = aHandle;
- db->aExtension[db->nExtension-1] = handle;
- return SQLITE_OK;
- }
- int sqlite3_load_extension(
- sqlite3 *db, /* Load the extension into this database connection */
- const char *zFile, /* Name of the shared library containing extension */
- const char *zProc, /* Entry point. Use "sqlite3_extension_init" if 0 */
- char **pzErrMsg /* Put error message here if not 0 */
- ){
- int rc;
- sqlite3_mutex_enter(db->mutex);
- rc = sqlite3LoadExtension(db, zFile, zProc, pzErrMsg);
- sqlite3_mutex_leave(db->mutex);
- return rc;
- }
- /*
- ** Call this routine when the database connection is closing in order
- ** to clean up loaded extensions
- */
- void sqlite3CloseExtensions(sqlite3 *db){
- int i;
- assert( sqlite3_mutex_held(db->mutex) );
- for(i=0; i<db->nExtension; i++){
- sqlite3OsDlClose(db->pVfs, db->aExtension[i]);
- }
- sqlite3_free(db->aExtension);
- }
- /*
- ** Enable or disable extension loading. Extension loading is disabled by
- ** default so as not to open security holes in older applications.
- */
- int sqlite3_enable_load_extension(sqlite3 *db, int onoff){
- sqlite3_mutex_enter(db->mutex);
- if( onoff ){
- db->flags |= SQLITE_LoadExtension;
- }else{
- db->flags &= ~SQLITE_LoadExtension;
- }
- sqlite3_mutex_leave(db->mutex);
- return SQLITE_OK;
- }
- #endif /* SQLITE_OMIT_LOAD_EXTENSION */
- /*
- ** The auto-extension code added regardless of whether or not extension
- ** loading is supported. We need a dummy sqlite3Apis pointer for that
- ** code if regular extension loading is not available. This is that
- ** dummy pointer.
- */
- #ifdef SQLITE_OMIT_LOAD_EXTENSION
- static const sqlite3_api_routines sqlite3Apis = { 0 };
- #endif
- /*
- ** The following object holds the list of automatically loaded
- ** extensions.
- **
- ** This list is shared across threads. The SQLITE_MUTEX_STATIC_MASTER
- ** mutex must be held while accessing this list.
- */
- static struct {
- int nExt; /* Number of entries in aExt[] */
- void **aExt; /* Pointers to the extension init functions */
- } autoext = { 0, 0 };
- /*
- ** Register a statically linked extension that is automatically
- ** loaded by every new database connection.
- */
- int sqlite3_auto_extension(void *xInit){
- int i;
- int rc = SQLITE_OK;
- sqlite3_mutex *mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER);
- sqlite3_mutex_enter(mutex);
- for(i=0; i<autoext.nExt; i++){
- if( autoext.aExt[i]==xInit ) break;
- }
- if( i==autoext.nExt ){
- int nByte = (autoext.nExt+1)*sizeof(autoext.aExt[0]);
- void **aNew;
- aNew = sqlite3_realloc(autoext.aExt, nByte);
- if( aNew==0 ){
- rc = SQLITE_NOMEM;
- }else{
- autoext.aExt = aNew;
- autoext.aExt[autoext.nExt] = xInit;
- autoext.nExt++;
- }
- }
- sqlite3_mutex_leave(mutex);
- assert( (rc&0xff)==rc );
- return rc;
- }
- /*
- ** Reset the automatic extension loading mechanism.
- */
- void sqlite3_reset_auto_extension(void){
- sqlite3_mutex *mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER);
- sqlite3_mutex_enter(mutex);
- sqlite3_free(autoext.aExt);
- autoext.aExt = 0;
- autoext.nExt = 0;
- sqlite3_mutex_leave(mutex);
- }
- /*
- ** Load all automatic extensions.
- */
- int sqlite3AutoLoadExtensions(sqlite3 *db){
- int i;
- int go = 1;
- int rc = SQLITE_OK;
- int (*xInit)(sqlite3*,char**,const sqlite3_api_routines*);
- if( autoext.nExt==0 ){
- /* Common case: early out without every having to acquire a mutex */
- return SQLITE_OK;
- }
- for(i=0; go; i++){
- char *zErrmsg = 0;
- sqlite3_mutex *mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER);
- sqlite3_mutex_enter(mutex);
- if( i>=autoext.nExt ){
- xInit = 0;
- go = 0;
- }else{
- xInit = (int(*)(sqlite3*,char**,const sqlite3_api_routines*))
- autoext.aExt[i];
- }
- sqlite3_mutex_leave(mutex);
- if( xInit && xInit(db, &zErrmsg, &sqlite3Apis) ){
- sqlite3Error(db, SQLITE_ERROR,
- "automatic extension loading failed: %s", zErrmsg);
- go = 0;
- rc = SQLITE_ERROR;
- sqlite3_free(zErrmsg);
- }
- }
- return rc;
- }