Oracle 使用sqlnet.ora/trigger限制/允许某IP或IP段访问指定用户

注释：
接触MySQL的朋友想必都知道mysql可针对指定IP/IP段来限制用户的访问，在Oracle数据库中默认有账号密码访问主机的权限的IP都可登陆该DB用户；
那么,Oracle 如何实现针对DB、单个用户来限制/允许IP访问呢？
1、整个DB层：可设置$ORACLE_HOME/network/admin/sqlnet.ora文件，限制/允许IP访问；  -->不可针对IP段..
2、单个用户：可通过trigger触发器限制/允许某IP或IP段访问；                 -->实验不可对整个DB层 (AFTER LOGON ON database)登陆提示告警..

一、sqlnet.ora
[oracle@10.240.1.7 admin]$ cat sqlnet.ora
tcp.validnode_checking = yes                       #需要设置成yes，方可激活生效
tcp.invited_nodes=(10.240.1.8,10.240.1.7)      #允许访问的IP
#tcp.excluded_nodes=(10.240.1.8,10.240.1.7) #不允许访问的IP
注释：
在9i提供了几个参数：-->9i以前版本更改protocol.ora文件...
TCP.EXCLUDED_NODES    ：设置禁止访问数据库的IP地址列表。
TCP.INVITED_NODES     ：设置允许访问数据库的IP地址列表，当这个参数和TCP.EXCLUDED_NODES设置的地址相同的时候将覆盖TCP.EXCLUDED_NODES设置。
TCP.VALIDNODE_CHECKING：检测上述参数的设置。

简单演示：
[oracle@10.240.1.8 ~]$ sqlplus lottery/lottery@10.240.1.7/test
SQL*Plus: Release 11.2.0.4.0 Production on Wed Apr 27 18:44:15 2016
Copyright (c) 1982, 2013, Oracle.  All rights reserved.
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
SQL>
[oracle@10.240.1.9 ~]$  sqlplus lottery/lottery@10.240.1.7/test
SQL*Plus: Release 11.2.0.4.0 Production on Wed Apr 27 18:44:40 2016
Copyright (c) 1982, 2013, Oracle.  All rights reserved.
ERROR:
ORA-12547: TNS:lost contact
ORA-01017: invalid username/password; logon denied
SP2-0157: unable to CONNECT to ORACLE after 3 attempts, exiting SQL*Plus
[oracle@10.240.1.9 ~]$

二、触发器
-->TRIGGER限制10.240.1.%网段访问lottery用户
CREATE OR REPLACE TRIGGER DISABLELOGIN
AFTER LOGON ON LOTTERY.SCHEMA  -->使用方式为USERNAME.SCHEMA，若直接写database，RAISE_APPLICATION_ERROR部分不起作用..
BEGIN
IF ORA_CLIENT_IP_ADDRESS LIKE ('10.240.1.%') THEN
RAISE_APPLICATION_ERROR(-20001,'USER '||ORA_LOGIN_USER||' IS NOT ALLOWED TO CONNECT FROM '||ORA_CLIENT_IP_ADDRESS);
END IF;
END;
--不能指定sys.schema，会报《ORA-30510: 系统触发器不能在 SYS 用户方案中定义》
--限制某IP  ORA_CLIENT_IP_ADDRESS IN ('10.240.1.7','10.240.1.8')

简单演示：
[oracle@10.240.1.7 ~]$ sqlplus lottery/lottery@10.240.1.7/test
SQL*Plus: Release 11.2.0.4.0 Production on Wed Apr 27 16:05:55 2016
Copyright (c) 1982, 2013, Oracle.  All rights reserved.
ERROR:
ORA-00604: error occurred at recursive SQL level 1
ORA-20001: USER LOTTERY IS NOT ALLOWED TO CONNECT FROM 10.240.1.7
ORA-06512: at line 3
[oracle@10.240.1.7 admin]$

[oracle@10.240.1.8 ~]$ sqlplus lottery/lottery@10.240.1.7/test
SQL*Plus: Release 11.2.0.4.0 Production on Wed Apr 27 16:05:55 2016
Copyright (c) 1982, 2013, Oracle.  All rights reserved.
ERROR:
ORA-00604: error occurred at recursive SQL level 1
ORA-20001: USER LOTTERY IS NOT ALLOWED TO CONNECT FROM 10.240.1.8
ORA-06512: at line 3
[oracle@10.240.1.8 ~]$

[oracle@10.240.2.8 ~]$  sqlplus lottery/lottery@10.240.1.7/test
SQL*Plus: Release 11.2.0.4.0 Production on Wed Apr 27 16:23:33 2016
Copyright (c) 1982, 2013, Oracle.  All rights reserved.
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
SQL>
SQL> SELECT * FROM DBA_TRIGGERS WHERE trigger_name='DISABLELOGIN' ;