由查找session IP 展开---函数、触发器、包
一、userenv函数、sys_context函数
--查看当前客户端会话的session IP信息
SQL>select sys_context(‘userenv‘,‘ip_address‘) from dual;
SYS_CONTEXT(‘USERENV‘,‘IP_ADDRESS‘)
--------------------------------------------------------------------------------
192.168.56.117
展开：可以通过userenv函数或者sys_context函数可以获得当前会话的信息
SQL>SELECT USERENV(‘LANGUAGE‘) FROM DUAL;
USERENV(‘LANGUAGE‘)
----------------------------------------------------
AMERICAN_AMERICA.ZHS16GBK
--使用参数列举
--ISDBA：返回当前用户是否是dba，如果是则返回true
--SESSION：返回当前会话的标志
--EXTRYID：返回会话入口标志
--INSTANCE：返回当前instance的标志
--LANGUAGE：返回当前环境语言变量
--LANG：返回当前环境的语言缩写
--TERMINAL：返回用户的终端或机器的标志
SQL>SELECT SYS_CONTEXT(‘USERENV‘,‘LANGUAGE‘) FROM DUAL;
SYS_CONTEXT(‘USERENV‘,‘LANGUAGE‘)
------------------------------------------------------------------------------------------------
AMERICAN_AMERICA.ZHS16GBK
SQL>select sys_context(‘userenv‘,‘host‘) from dual;
SYS_CONTEXT(‘USERENV‘,‘HOST‘)
--------------------------------------------------------------------------------
WORKGROUP\FPA4GFVZXULBFCR
二、v$session视图中
通过v$session视图，将客户端IP信息存入client_identifier字段或client_info字段
使用client_info字段
SQL>execdbms_application_info.set_client_info(sys_context(‘userenv‘,‘ip_address‘));
SQL>select username,sid,serial#,client_info,client_identifier from v$session wheresid=(select sys_context(‘userenv‘,‘sid‘) from dual);
使用client_identifier字段
SQL>exec dbms_session.set_identifier(sys_context(‘userenv‘,‘ip_address‘));
SQL>select username,sid,serial#,client_info,client_identifier from v$session wheresid=(select sys_context(‘userenv‘,‘sid‘) from dual);
范例截图如下：
三、触发器
通过触发器调用，新的客户端连接开启时自动触发，将IP信息写入client_info字段
create or replace triggeron_login_trigger
after logon on database
begin
dbms_application_info.set_client_info(sys_context(‘USERENV‘,‘IP_ADDRESS‘));
end;
/
通过触发器调用，新的客户端连接开启时自动触发，将IP信息写入client_identifier字段
create or replace triggeron_login_trigger
after logon on database
begin
dbms_session.set_identifier(sys_context(‘userenv‘,‘ip_address‘));
end;
/
四、使用UTL_INADDR Package
在没有触发器记录的前提下，通过UTL_INADDR Package来实现获取SESSION IP，而且可以获取其它SESSION IP。
通过说明UTL_INADDR Package的工作原理，体现出UTL_INADDR Package是如何实现的。
实验分析开始：
[[email protected]~]# ps -ef |grep sql
oracle 2740 2707 0 21:17 pts/1 00:00:00 sqlplus
oracle 3479 3451 0 21:49 pts/2 00:00:00 sqlplus
root 3482 3375 0 21:49 pts/3 00:00:00 grep sql
[[email protected]~]# su - oracle
[[email protected]~]$ ps -ef |grep LO
oracle 2770 2740 0 21:18 ? 00:00:00 oraclemetro (DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))
oracle 3480 3479 0 21:49 ? 00:00:00 oraclemetro(DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))
oracle 3520 3488 0 21:50 pts/3 00:00:00 grep LO
补充：安装strace工具，跟踪进程执行时的系统调用和所接收的信号。
——引用自网络，strace注解：在Linux世界，进程不能直接访问硬件设备，当进程需要访问硬件设备(比如读取磁盘文件，接收网络数据等等)时，必须由用户态模式切换至内核态模式，通过系统调用访问硬件设备。strace可以跟踪到一个进程产生的系统调用,包括参数，返回值，执行消耗的时间。
——引用结束。
[[email protected]_5.5 x86_64 DVD]# cd Server/ --使用linux光盘安装工具
[[email protected]]# ls -ll |grep strace
-r--r--r-- 326root root 175066 Jan 18 2010 strace-4.5.18-5.el5_4.1.i386.rpm
[[email protected]]# rpm -ivh strace-4.5.18-5.el5_4.1.i386.rpm
warning:strace-4.5.18-5.el5_4.1.i386.rpm: Header V3 DSA signature: NOKEY, key ID37017186
Preparing... ########################################### [100%]
1:strace ###########################################[100%]
[[email protected]]# rpm -qa |grep strace
strace-4.5.18-5.el5_4.1
补充完毕
[[email protected]~]$ strace -p 2770 --打开跟踪
SQL>SELECT UTL_INADDR.get_host_address(‘org54‘) from dual; --执行查询
UTL_INADDR.GET_HOST_ADDRESS(‘ORG54‘)
--------------------------------------------------------------------------------------------------------
192.168.56.5
到strace跟踪信息界面下，查看信息如下：
Process 2770attached - interrupt to quit
read(8,"\0\323\0\0\6\0\0\0\0\0\3^!a\200\0\0\0\0\0\0TL\351\tj\0\0\0|\360\345"...,2064) = 211
gettimeofday({1404438819,340059}, NULL) = 0
gettimeofday({1404438819,340388}, NULL) = 0
getrusage(RUSAGE_SELF,{ru_utime={0, 440932}, ru_stime={0, 423935}, ...}) = 0
times(NULL) = 429805698
gettimeofday({1404438819,343035}, NULL) = 0
gettimeofday({1404438819,343625}, NULL) = 0
getrusage(RUSAGE_SELF,{ru_utime={0, 440932}, ru_stime={0, 423935}, ...}) = 0
gettimeofday({1404438819,344254}, NULL) = 0
times(NULL) = 429805698
getrusage(RUSAGE_SELF,{ru_utime={0, 440932}, ru_stime={0, 423935}, ...}) = 0
getrusage(RUSAGE_SELF,{ru_utime={0, 440932}, ru_stime={0, 423935}, ...}) = 0
times(NULL) = 429805698
gettimeofday({1404438819,345897}, NULL) = 0
gettimeofday({1404438819,346375}, NULL) = 0
getrusage(RUSAGE_SELF,{ru_utime={0, 440932}, ru_stime={0, 423935}, ...}) = 0
getrusage(RUSAGE_SELF,{ru_utime={0, 440932}, ru_stime={0, 423935}, ...}) = 0
gettimeofday({1404438819,348358}, NULL) = 0
getrusage(RUSAGE_SELF,{ru_utime={0, 440932}, ru_stime={0, 423935}, ...}) = 0
gettimeofday({1404438819,349038}, NULL) = 0
gettimeofday({1404438819,349493}, NULL) = 0
gettimeofday({1404438819,349742}, NULL) = 0
gettimeofday({1404438819,350092}, NULL) = 0
getrusage(RUSAGE_SELF,{ru_utime={0, 440932}, ru_stime={0, 423935}, ...}) = 0
gettimeofday({1404438819,350832}, NULL) = 0
gettimeofday({1404438819,351126}, NULL) = 0
gettimeofday({1404438819,351435}, NULL) = 0
gettimeofday({1404438819,351851}, NULL) = 0
gettimeofday({1404438819,352268}, NULL) = 0
getrusage(RUSAGE_SELF,{ru_utime={0, 440932}, ru_stime={0, 423935}, ...}) = 0
gettimeofday({1404438819,353079}, NULL) = 0
gettimeofday({1404438819,353494}, NULL) = 0
open("/etc/hosts",O_RDONLY) = 24
--注意此条语句，表示当我们进行UTL_INADDR.get_host_address查询时，后台进程会去读取hosts文件，如果存在解析关系，便会返回信息显示，以下会验证如果没有解析的现象
fcntl64(24,F_GETFD) = 0
fcntl64(24,F_SETFD, FD_CLOEXEC) = 0
fstat64(24,{st_mode=S_IFREG|0644, st_size=416, ...}) = 0
mmap2(NULL,4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x11a000
read(24,"# Do not remove the following li"..., 4096) = 416
close(24) = 0
munmap(0x11a000,4096) = 0
gettimeofday({1404438819,359617}, NULL) = 0
gettimeofday({1404438819,359908}, NULL) = 0
getrusage(RUSAGE_SELF,{ru_utime={0, 441932}, ru_stime={0, 424935}, ...}) = 0
gettimeofday({1404438819,360851}, NULL) = 0
gettimeofday({1404438819,363074}, NULL) = 0
getrusage(RUSAGE_SELF,{ru_utime={0, 442932}, ru_stime={0, 424935}, ...}) = 0
getrusage(RUSAGE_SELF,{ru_utime={0, 442932}, ru_stime={0, 424935}, ...}) = 0
times(NULL) = 429805700
gettimeofday({1404438819,366127}, NULL) = 0
write(11,"\1Q\0\0\6\0\0\0\0\0\20\27\30\252g\312N\23\337\326\212\21+%R>\367|xr\7\3"...,337) = 337
read(8,"\0\25\0\0\6\0\0\0\0\0\3\5\"\21\0\0\0\17\0\0\0", 2064) = 21
gettimeofday({1404438819,369259}, NULL) = 0
gettimeofday({1404438819,369906}, NULL) = 0
getrusage(RUSAGE_SELF,{ru_utime={0, 442932}, ru_stime={0, 424935}, ...}) = 0
times(NULL) = 429805701
gettimeofday({1404438819,370962}, NULL) = 0
gettimeofday({1404438819,371394}, NULL) = 0
getrusage(RUSAGE_SELF,{ru_utime={0, 442932}, ru_stime={0, 424935}, ...}) = 0
gettimeofday({1404438819,372304}, NULL) = 0
gettimeofday({1404438819,372741}, NULL) = 0
gettimeofday({1404438819,373117}, NULL) = 0
getrusage(RUSAGE_SELF,{ru_utime={0, 442932}, ru_stime={0, 424935}, ...}) = 0
getrusage(RUSAGE_SELF,{ru_utime={0, 442932}, ru_stime={0, 424935}, ...}) = 0
times(NULL) = 429805701
gettimeofday({1404438819,375003}, NULL) = 0
gettimeofday({1404438819,375561}, NULL) = 0
gettimeofday({1404438819,376567}, NULL) = 0
write(11,"\0\204\0\0\6\0\0\0\0\0\4\1\0\0\0\37\0\1\1\0\0\0{\5\0\0\0\0\21\0\0\0"...,132) = 132
read(8,"\0\34\0\0\6\0\0\0\0\0\21i#L,\351\t\1\0\0\0\21\0\0\0\3\223$", 2064) =28
gettimeofday({1404438819,378886}, NULL) = 0
gettimeofday({1404438819,379120}, NULL) = 0
getrusage(RUSAGE_SELF,{ru_utime={0, 442932}, ru_stime={0, 424935}, ...}) = 0
times(NULL) = 429805702
gettimeofday({1404438819,380076}, NULL) = 0
gettimeofday({1404438819,380433}, NULL) = 0
getrusage(RUSAGE_SELF,{ru_utime={0, 442932}, ru_stime={0, 424935}, ...}) = 0
getrusage(RUSAGE_SELF,{ru_utime={0, 442932}, ru_stime={0, 424935}, ...}) = 0
times(NULL) = 429805702
getrusage(RUSAGE_SELF,{ru_utime={0, 442932}, ru_stime={0, 424935}, ...}) = 0
times(NULL) = 429805702
gettimeofday({1404438819,384734}, NULL) = 0
gettimeofday({1404438819,385145}, NULL) = 0
getrusage(RUSAGE_SELF,{ru_utime={0, 442932}, ru_stime={0, 424935}, ...}) = 0
getrusage(RUSAGE_SELF,{ru_utime={0, 442932}, ru_stime={0, 424935}, ...}) = 0
times(NULL) = 429805703
gettimeofday({1404438819,386442}, NULL) = 0
gettimeofday({1404438819,386802}, NULL) = 0
gettimeofday({1404438819,387042}, NULL) = 0
write(11,"\0\21\0\0\6\0\0\0\0\0\t\1\0\0\0!\0", 17) = 17
read(8,
*缺少hosts解析时，UTL_INADDR.get_host_address查询现象
[[email protected]~]# vi /etc/hosts --将客户端FPA4GFVZXULBFCR解析地址注释掉
# Do notremove the following line, or various programs
# that requirenetwork functionality will fail.
127.0.0.1 localhost.localdomain localhost
::1 localhost6.localdomain6 localhost6
192.168.56.11rac11
192.168.56.22rac22
192.168.56.31rac11-vip
192.168.56.32rac22-vip
192.168.2.11rac11-priv
192.168.2.22rac22-priv
192.168.56.7node1
192.168.56.8gc1
192.168.56.5 org54
#192.168.56.117FPA4GFVZXULBFCR
~
~
"/etc/hosts"19L, 417C written
客户端登陆
主机端：
SQL>col MACHINE for a50
SQL>select username,machine,program,sql_id from v$session where username is notnull
--查询到登陆主机
USERNAME MACHINE PROGRAM SQL_ID
------------------------------------------------------------- -------------
SYS org54 [email protected] (TNS V1-V3)
SCOTT WORKGROUP\FPA4GFVZXULBFCR sqlplus.exe
SYS org54 [email protected] (TNS V1-V3) 8w8k8ss45hm25
SQL>select UTL_INADDR.get_host_address(‘FPA4GFVZXULBFCR‘) from dual; --在没有hosts解析的情况下，报错了
selectUTL_INADDR.get_host_address(‘FPA4GFVZXULBFCR‘) from dual
*
ERROR at line1:
ORA-29257:host FPA4GFVZXULBFCR unknown
ORA-06512: at"SYS.UTL_INADDR", line 19
ORA-06512: at"SYS.UTL_INADDR", line 40
ORA-06512: atline 1
[[email protected]~]# vi /etc/hosts --将客户端FPA4GFVZXULBFCR解析地址重新添加进去
# Do notremove the following line, or various programs
# that requirenetwork functionality will fail.
127.0.0.1 localhost.localdomain localhost
::1 localhost6.localdomain6 localhost6
192.168.56.11rac11
192.168.56.22rac22
192.168.56.31rac11-vip
192.168.56.32rac22-vip
192.168.2.11rac11-priv
192.168.2.22rac22-priv
192.168.56.7node1
192.168.56.8gc1
192.168.56.5 org54
192.168.56.117FPA4GFVZXULBFCR
~
~
"/etc/hosts"19L, 417C written
SQL>select UTL_INADDR.get_host_address(‘FPA4GFVZXULBFCR‘) from dual; --再次发起查询
UTL_INADDR.GET_HOST_ADDRESS(‘FPA4GFVZXULBFCR‘)
--------------------------------------------------------------------------------------------------------
192.168.56.117
小结：
综上可知，使用UTL_INADDR Package在捕获SESSION IP时不再依赖数据库的信息。在触发器没有记录的情况下，可以实现捕捉其它SESSION的地址信息。
***********************************************声明************************************************
原创作品，出自 “深蓝的blog” 博客，欢迎转载，转载时请务必注明出处（http://blog.csdn.net/huangyanlong）。
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