/* Copyright (C) 2000 MySQL AB This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ /* This implements 'user defined functions' */ /* ** Known bugs: ** ** Memory for functions are never freed! ** Shared libraries are not closed before mysqld exists; ** - This is because we can't be sure if some threads is using ** a functions. ** ** The buggs only affects applications that creates and frees a lot of ** dynamic functions, so this shouldn't be a real problem. */ #ifdef __GNUC__ #pragma implementation // gcc: implement sql_udf.h #endif #include "mysql_priv.h" #include <my_pthread.h> #ifdef HAVE_DLOPEN extern "C" { #if defined(__WIN__) void* dlsym(void* lib,const char* name) { return GetProcAddress((HMODULE)lib,name); } void* dlopen(const char* libname,int unused) { return LoadLibraryEx(libname,NULL,0); } void dlclose(void* lib) { FreeLibrary((HMODULE)lib); } #elif !defined(OS2) #include <dlfcn.h> #endif #include <stdarg.h> #include <hash.h> } #ifndef RTLD_NOW #define RTLD_NOW 1 // For FreeBSD 2.2.2 #endif #ifndef HAVE_DLERROR #define dlerror() "" #endif static bool initialized = 0; static MEM_ROOT mem; static HASH udf_hash; static rw_lock_t THR_LOCK_udf; static udf_func *add_udf(LEX_STRING *name, Item_result ret, char *dl, Item_udftype typ); static void del_udf(udf_func *udf); static void *find_udf_dl(const char *dl); static void init_syms(udf_func *tmp) { char nm[MAX_FIELD_NAME+16],*end; tmp->func = dlsym(tmp->dlhandle, tmp->name.str); end=strmov(nm,tmp->name.str); (void) strmov(end,"_init"); tmp->func_init = dlsym(tmp->dlhandle, nm); (void) strmov(end,"_deinit"); tmp->func_deinit = dlsym(tmp->dlhandle, nm); if (tmp->type == UDFTYPE_AGGREGATE) { (void)strmov( end, "_clear" ); tmp->func_clear = dlsym( tmp->dlhandle, nm ); (void)strmov( end, "_add" ); tmp->func_add = dlsym( tmp->dlhandle, nm ); /* Give error if _clear and _add doesn't exists */ if (!tmp->func_clear || ! tmp->func_add) tmp->func= 0; } } extern "C" byte* get_hash_key(const byte *buff,uint *length, my_bool not_used __attribute__((unused))) { udf_func *udf=(udf_func*) buff; *length=(uint) udf->name.length; return (byte*) udf->name.str; } /* ** Read all predeclared functions from func@mysql and accept all that ** can be used. */ void udf_init() { udf_func *tmp; TABLE_LIST tables; READ_RECORD read_record_info; TABLE *table; int error; DBUG_ENTER("ufd_init"); if (initialized) DBUG_VOID_RETURN; my_rwlock_init(&THR_LOCK_udf,NULL); init_sql_alloc(&mem, UDF_ALLOC_BLOCK_SIZE, 0); THD *new_thd = new THD; if (!new_thd || hash_init(&udf_hash,system_charset_info,32,0,0,get_hash_key, NULL, 0)) { sql_print_error("Can't allocate memory for udf structures"); hash_free(&udf_hash); free_root(&mem,MYF(0)); delete new_thd; DBUG_VOID_RETURN; } initialized = 1; new_thd->store_globals(); new_thd->db= my_strdup("mysql", MYF(0)); new_thd->db_length=5; bzero((gptr) &tables,sizeof(tables)); tables.alias= tables.real_name= (char*) "func"; tables.lock_type = TL_READ; tables.db=new_thd->db; if (simple_open_n_lock_tables(new_thd, &tables)) { DBUG_PRINT("error",("Can't open udf table")); sql_print_error("Can't open the mysql/func table. Please run the mysql_install_db script to create it."); goto end; } table= tables.table; init_read_record(&read_record_info, new_thd, table, NULL,1,0); while (!(error = read_record_info.read_record(&read_record_info))) { DBUG_PRINT("info",("init udf record")); LEX_STRING name; name.str=get_field(&mem, table->field[0]); name.length = strlen(name.str); char *dl_name= get_field(&mem, table->field[2]); bool new_dl=0; Item_udftype udftype=UDFTYPE_FUNCTION; if (table->fields >= 4) // New func table udftype=(Item_udftype) table->field[3]->val_int(); if (!(tmp = add_udf(&name,(Item_result) table->field[1]->val_int(), dl_name, udftype))) { sql_print_error("Can't alloc memory for udf function: name"); continue; } void *dl = find_udf_dl(tmp->dl); if (dl == NULL) { if (!(dl = dlopen(tmp->dl, RTLD_NOW))) { /* Print warning to log */ sql_print_error(ER(ER_CANT_OPEN_LIBRARY), tmp->dl,errno,dlerror()); /* Keep the udf in the hash so that we can remove it later */ continue; } new_dl=1; } tmp->dlhandle = dl; init_syms(tmp); if (!tmp->func) { sql_print_error(ER(ER_CANT_FIND_DL_ENTRY), name); del_udf(tmp); if (new_dl) dlclose(dl); } } if (error > 0) sql_print_error(ER(ER_GET_ERRNO), my_errno); end_read_record(&read_record_info); new_thd->version--; // Force close to free memory end: close_thread_tables(new_thd); delete new_thd; /* Remember that we don't have a THD */ my_pthread_setspecific_ptr(THR_THD, 0); DBUG_VOID_RETURN; } void udf_free() { /* close all shared libraries */ DBUG_ENTER("udf_free"); for (uint idx=0 ; idx < udf_hash.records ; idx++) { udf_func *udf=(udf_func*) hash_element(&udf_hash,idx); if (udf->dlhandle) // Not closed before { /* Mark all versions using the same handler as closed */ for (uint j=idx+1 ; j < udf_hash.records ; j++) { udf_func *tmp=(udf_func*) hash_element(&udf_hash,j); if (udf->dlhandle == tmp->dlhandle) tmp->dlhandle=0; // Already closed } dlclose(udf->dlhandle); } } hash_free(&udf_hash); free_root(&mem,MYF(0)); if (initialized) { initialized= 0; rwlock_destroy(&THR_LOCK_udf); } DBUG_VOID_RETURN; } static void del_udf(udf_func *udf) { DBUG_ENTER("del_udf"); if (!--udf->usage_count) { hash_delete(&udf_hash,(byte*) udf); using_udf_functions=udf_hash.records != 0; } else { /* The functions is in use ; Rename the functions instead of removing it. The functions will be automaticly removed when the least threads doesn't use it anymore */ char *name= udf->name.str; uint name_length=udf->name.length; udf->name.str=(char*) "*"; udf->name.length=1; hash_update(&udf_hash,(byte*) udf,(byte*) name,name_length); } DBUG_VOID_RETURN; } void free_udf(udf_func *udf) { DBUG_ENTER("free_udf"); rw_wrlock(&THR_LOCK_udf); if (!--udf->usage_count) { /* We come here when someone has deleted the udf function while another thread still was using the udf */ hash_delete(&udf_hash,(byte*) udf); using_udf_functions=udf_hash.records != 0; if (!find_udf_dl(udf->dl)) dlclose(udf->dlhandle); } rw_unlock(&THR_LOCK_udf); DBUG_VOID_RETURN; } /* This is only called if using_udf_functions != 0 */ udf_func *find_udf(const char *name,uint length,bool mark_used) { udf_func *udf=0; DBUG_ENTER("find_udf"); /* TODO: This should be changed to reader locks someday! */ rw_rdlock(&THR_LOCK_udf); if ((udf=(udf_func*) hash_search(&udf_hash,(byte*) name, length ? length : (uint) strlen(name)))) { if (!udf->dlhandle) udf=0; // Could not be opened else if (mark_used) udf->usage_count++; } rw_unlock(&THR_LOCK_udf); DBUG_RETURN(udf); } static void *find_udf_dl(const char *dl) { DBUG_ENTER("find_udf_dl"); /* Because only the function name is hashed, we have to search trough all rows to find the dl. */ for (uint idx=0 ; idx < udf_hash.records ; idx++) { udf_func *udf=(udf_func*) hash_element(&udf_hash,idx); if (!strcmp(dl, udf->dl) && udf->dlhandle != NULL) DBUG_RETURN(udf->dlhandle); } DBUG_RETURN(0); } /* Assume that name && dl is already allocated */ static udf_func *add_udf(LEX_STRING *name, Item_result ret, char *dl, Item_udftype type) { if (!name || !dl || !(uint) type || (uint) type > (uint) UDFTYPE_AGGREGATE) return 0; udf_func *tmp= (udf_func*) alloc_root(&mem, sizeof(udf_func)); if (!tmp) return 0; bzero((char*) tmp,sizeof(*tmp)); tmp->name = *name; //dup !! tmp->dl = dl; tmp->returns = ret; tmp->type = type; tmp->usage_count=1; if (my_hash_insert(&udf_hash,(byte*) tmp)) return 0; using_udf_functions=1; return tmp; } int mysql_create_function(THD *thd,udf_func *udf) { int error; void *dl=0; bool new_dl=0; TABLE *table; TABLE_LIST tables; udf_func *u_d; DBUG_ENTER("mysql_create_function"); if (!initialized) { send_error(thd, ER_OUT_OF_RESOURCES, ER(ER_OUT_OF_RESOURCES)); DBUG_RETURN(1); } /* Ensure that the .dll doesn't have a path This is done to ensure that only approved dll from the system directories are used (to make this even remotely secure). */ if (strchr(udf->dl, '/')) { send_error(thd, ER_UDF_NO_PATHS,ER(ER_UDF_NO_PATHS)); DBUG_RETURN(1); } if (udf->name.length > NAME_LEN) { net_printf(thd, ER_TOO_LONG_IDENT,udf->name); DBUG_RETURN(1); } rw_wrlock(&THR_LOCK_udf); if ((hash_search(&udf_hash,(byte*) udf->name.str, udf->name.length))) { net_printf(thd, ER_UDF_EXISTS, udf->name); goto err; } if (!(dl = find_udf_dl(udf->dl))) { if (!(dl = dlopen(udf->dl, RTLD_NOW))) { DBUG_PRINT("error",("dlopen of %s failed, error: %d (%s)", udf->dl,errno,dlerror())); net_printf(thd, ER_CANT_OPEN_LIBRARY, udf->dl, errno, dlerror()); goto err; } new_dl=1; } udf->dlhandle=dl; init_syms(udf); if (udf->func == NULL) { net_printf(thd, ER_CANT_FIND_DL_ENTRY, udf->name); goto err; } udf->name.str=strdup_root(&mem,udf->name.str); udf->dl=strdup_root(&mem,udf->dl); if (!(u_d=add_udf(&udf->name,udf->returns,udf->dl,udf->type))) { send_error(thd,0); // End of memory goto err; } u_d->dlhandle = dl; u_d->func=udf->func; u_d->func_init=udf->func_init; u_d->func_deinit=udf->func_deinit; u_d->func_clear=udf->func_clear; u_d->func_add=udf->func_add; /* create entry in mysql/func table */ bzero((char*) &tables,sizeof(tables)); tables.db= (char*) "mysql"; tables.real_name= tables.alias= (char*) "func"; /* Allow creation of functions even if we can't open func table */ if (!(table = open_ltable(thd,&tables,TL_WRITE))) goto err; restore_record(table,default_values); // Default values for fields table->field[0]->store(u_d->name.str, u_d->name.length, system_charset_info); table->field[1]->store((longlong) u_d->returns); table->field[2]->store(u_d->dl,(uint) strlen(u_d->dl), system_charset_info); if (table->fields >= 4) // If not old func format table->field[3]->store((longlong) u_d->type); error = table->file->write_row(table->record[0]); close_thread_tables(thd); if (error) { net_printf(thd, ER_ERROR_ON_WRITE, "func@mysql",error); del_udf(u_d); goto err; } rw_unlock(&THR_LOCK_udf); DBUG_RETURN(0); err: if (new_dl) dlclose(dl); rw_unlock(&THR_LOCK_udf); DBUG_RETURN(1); } int mysql_drop_function(THD *thd,const LEX_STRING *udf_name) { TABLE *table; TABLE_LIST tables; udf_func *udf; DBUG_ENTER("mysql_drop_function"); if (!initialized) { send_error(thd, ER_OUT_OF_RESOURCES, ER(ER_OUT_OF_RESOURCES)); DBUG_RETURN(1); } rw_wrlock(&THR_LOCK_udf); if (!(udf=(udf_func*) hash_search(&udf_hash,(byte*) udf_name->str, (uint) udf_name->length))) { net_printf(thd, ER_FUNCTION_NOT_DEFINED, udf_name); goto err; } del_udf(udf); /* Close the handle if this was function that was found during boot or CREATE FUNCTION and it's not in use by any other udf function */ if (udf->dlhandle && !find_udf_dl(udf->dl)) dlclose(udf->dlhandle); bzero((char*) &tables,sizeof(tables)); tables.db=(char*) "mysql"; tables.real_name= tables.alias= (char*) "func"; if (!(table = open_ltable(thd,&tables,TL_WRITE))) goto err; if (!table->file->index_read_idx(table->record[0],0,(byte*) udf_name->str, (uint) udf_name->length, HA_READ_KEY_EXACT)) { int error; if ((error = table->file->delete_row(table->record[0]))) table->file->print_error(error, MYF(0)); } close_thread_tables(thd); rw_unlock(&THR_LOCK_udf); DBUG_RETURN(0); err: rw_unlock(&THR_LOCK_udf); DBUG_RETURN(1); } #endif /* HAVE_DLOPEN */