Fix for #2212 (mysql_change_user doesn't work in embedded library)

now it's working


include/mysql.h:
  read_change_user_result 'virtual' method added
libmysql/client_settings.h:
  cli_read_change_user_result interface
libmysql/libmysql.c:
  cli_read_change_user_result implementation
libmysqld/lib_sql.cc:
  emb_read_change_user_result implementation
sql-common/client.c:
  cli_read_change_user_result added to the method's table
sql/sql_parse.cc:
  fixes to make mysql_change_user working in embedded library

include/mysql.h

@@ -575,6 +575,7 @@ typedef struct st_mysql_methods
   void (*free_embedded_thd)(MYSQL *mysql);
   const char *(*read_statistic)(MYSQL *mysql);
   int (*next_result)(MYSQL *mysql);
+  int (*read_change_user_result)(MYSQL *mysql, char *buff, const char *passwd);
 #endif
 } MYSQL_METHODS;
 

libmysql/client_settings.h

@@ -58,6 +58,7 @@ int cli_stmt_execute(MYSQL_STMT *stmt);
 MYSQL_DATA * cli_read_binary_rows(MYSQL_STMT *stmt);
 int cli_unbuffered_fetch(MYSQL *mysql, char **row);
 const char * cli_read_statistic(MYSQL *mysql);
+int cli_read_change_user_result(MYSQL *mysql, char *buff, const char *passwd);
 
 #ifdef EMBEDDED_LIBRARY
 int init_embedded_server(int argc, char **argv, char **groups);

libmysql/libmysql.c

@@ -606,13 +606,42 @@ mysql_connect(MYSQL *mysql,const char *host,
 /**************************************************************************
   Change user and database
 **************************************************************************/
+int cli_read_change_user_result(MYSQL *mysql, char *buff, const char *passwd)
+{
+  NET *net= &mysql->net;
+  ulong pkt_length;
+
+  pkt_length= net_safe_read(mysql);
+  
+  if (pkt_length == packet_error)
+    return 1;
+
+  if (pkt_length == 1 && net->read_pos[0] == 254 &&
+      mysql->server_capabilities & CLIENT_SECURE_CONNECTION)
+  {
+    /*
+      By sending this very specific reply server asks us to send scrambled
+      password in old format. The reply contains scramble_323.
+    */
+    scramble_323(buff, mysql->scramble, passwd);
+    if (my_net_write(net, buff, SCRAMBLE_LENGTH_323 + 1) || net_flush(net))
+    {
+      net->last_errno= CR_SERVER_LOST;
+      strmov(net->sqlstate, unknown_sqlstate);
+      strmov(net->last_error,ER(net->last_errno));
+      return 1;
+    }
+    /* Read what server thinks about out new auth message report */
+    if (net_safe_read(mysql) == packet_error)
+      return 1;
+  }
+  return 0;
+}
 
 my_bool	STDCALL mysql_change_user(MYSQL *mysql, const char *user,
 				  const char *passwd, const char *db)
 {
   char buff[512],*end=buff;
-  NET *net= &mysql->net;
-  ulong pkt_length;
   DBUG_ENTER("mysql_change_user");
 
   if (!user)
@@ -646,31 +675,8 @@ my_bool	STDCALL mysql_change_user(MYSQL *mysql, const char *user,
   /* Write authentication package */
   simple_command(mysql,COM_CHANGE_USER, buff,(ulong) (end-buff),1);
 
-  pkt_length= net_safe_read(mysql);
+  if ((*mysql->methods->read_change_user_result)(mysql, buff, passwd))
-
+    DBUG_RETURN(1);
-  if (pkt_length == packet_error)
-    goto error;
-
-  if (pkt_length == 1 && net->read_pos[0] == 254 &&
-      mysql->server_capabilities & CLIENT_SECURE_CONNECTION)
-  {
-    /*
-      By sending this very specific reply server asks us to send scrambled
-      password in old format. The reply contains scramble_323.
-    */
-    scramble_323(buff, mysql->scramble, passwd);
-    if (my_net_write(net, buff, SCRAMBLE_LENGTH_323 + 1) || net_flush(net))
-    {
-      net->last_errno= CR_SERVER_LOST;
-      strmov(net->sqlstate, unknown_sqlstate);
-      strmov(net->last_error,ER(net->last_errno));
-      goto error;
-    }
-    /* Read what server thinks about out new auth message report */
-    if (net_safe_read(mysql) == packet_error)
-      goto error;
-  }
-
   /* Free old connect information */
   my_free(mysql->user,MYF(MY_ALLOW_ZERO_PTR));
   my_free(mysql->passwd,MYF(MY_ALLOW_ZERO_PTR));
@@ -681,9 +687,6 @@ my_bool	STDCALL mysql_change_user(MYSQL *mysql, const char *user,
   mysql->passwd=my_strdup(passwd,MYF(MY_WME));
   mysql->db=    db ? my_strdup(db,MYF(MY_WME)) : 0;
   DBUG_RETURN(0);
-
-error:
-  DBUG_RETURN(1);
 }
 
 #if defined(HAVE_GETPWUID) && defined(NO_GETPWUID_DECL)

libmysqld/lib_sql.cc

@@ -258,6 +258,13 @@ int emb_next_result(MYSQL *mysql)
   DBUG_RETURN(0);				/* No more results */
 }
 
+int emb_read_change_user_result(MYSQL *mysql, 
+				char *buff __attribute__((unused)),
+				const char *passwd __attribute__((unused)))
+{
+  return mysql_errno(mysql);
+}
+
 MYSQL_METHODS embedded_methods= 
 {
   emb_mysql_read_query_result,
@@ -272,7 +279,8 @@ MYSQL_METHODS embedded_methods=
   emb_unbuffered_fetch,
   emb_free_embedded_thd,
   emb_read_statistic,
-  emb_next_result
+  emb_next_result,
+  emb_read_change_user_result
 };
 
 C_MODE_END

sql-common/client.c

@@ -1421,7 +1421,8 @@ static MYSQL_METHODS client_methods=
   cli_unbuffered_fetch,
   NULL,
   cli_read_statistic,
-  cli_read_query_result
+  cli_read_query_result,
+  cli_read_change_user_result
 #endif
 };
 

sql/sql_parse.cc

@@ -206,7 +206,21 @@ int check_user(THD *thd, enum enum_server_command command,
   
 #ifdef NO_EMBEDDED_ACCESS_CHECKS
   thd->master_access= GLOBAL_ACLS;			// Full rights
-  return 0;
+  /* Change database if necessary: OK or FAIL is sent in mysql_change_db */
+  if (db && db[0])
+  {
+    thd->db= 0;
+    thd->db_length= 0;
+    if (mysql_change_db(thd, db))
+    {
+      if (thd->user_connect)
+	decrease_user_connections(thd->user_connect);
+      DBUG_RETURN(-1);
+    }
+  }
+  else
+    send_ok(thd);
+  DBUG_RETURN(0);
 #else
 
   my_bool opt_secure_auth_local;
@@ -1282,7 +1296,6 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
       send_error(thd); // dump to NET
     break;
   }
-#ifndef EMBEDDED_LIBRARY
   case COM_CHANGE_USER:
   {
     thd->change_user();
@@ -1301,13 +1314,14 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
     uint passwd_len= thd->client_capabilities & CLIENT_SECURE_CONNECTION ? 
       *passwd++ : strlen(passwd);
     db+= passwd_len + 1;
+#ifndef EMBEDDED_LIBRARY
     /* Small check for incomming packet */
     if ((uint) ((uchar*) db - net->read_pos) > packet_length)
     {
       send_error(thd, ER_UNKNOWN_COM_ERROR);
       break;
     }
-
+#endif
     /* Convert database name to utf8 */
     db_buff[copy_and_convert(db_buff, sizeof(db_buff)-1,
                              system_charset_info, db, strlen(db),
@@ -1358,7 +1372,6 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
     }
     break;
   }
-#endif /* EMBEDDED_LIBRARY */
   case COM_EXECUTE:
   {
     mysql_stmt_execute(thd, packet);