net-snmp c开发

Net-snmp 使用c 扩展agent

摘要：

netSNMP开发，使用c开发对SNMP进行扩展，将代码编译到netsnmp中。

官网：https://www.360docs.net/doc/1713829134.html,

版本：NET-SNMP version 5.7.2.1

系统：CentOS X64

软件包：net-snmp-5.7.2.1.tar.gz

解压安装包：

[root@localhost snmp]# pwd

/root/snmp

[root@localhost snmp]# ls

net-snmp-5.7.2.1.tar.gz

[root@localhost snmp]# tar xzvf net-snmp-5.7.2.1.tar.gz

[root@localhost snmp]# ls

net-snmp-5.7.2.1 net-snmp-5.7.2.1.tar.gz

配置

[root@localhost snmp]# cd net-snmp-5.7.2.1

[root@localhost net-snmp-5.7.2.1]# pwd

/root/snmp/net-snmp-5.7.2.1

[root@localhost net-snmp-5.7.2.1]# ./configure

配置完成后，会显示如下configure摘要信息

---------------------------------------------------------

Net-SNMP configuration summary:

---------------------------------------------------------

SNMP Versions Supported: 1 2c 3

Building for: linux

Net-SNMP Version: 5.7.2.1

Network transport support: Callback Unix Alias TCP UDP IPv4Base SocketBase TCPBase UDPIPv4Base UDPBase

SNMPv3 Security Modules: usm

Agent MIB code: default_modules => snmpv3mibs mibII ucd_snmp notification notification-log-mib target agent_mibs agentx disman/event disman/schedule utilities host

MYSQL Trap Logging: unavailable

Embedded Perl support: enabled

SNMP Perl modules: building -- embeddable

SNMP Python modules: disabled

Crypto support from: crypto

Authentication support: MD5 SHA1

Encryption support: DES AES

Local DNSSEC validation: disabled

编译、安装

make && make install

配置snmpd.conf

[root@localhost snmp]# pwd

/usr/local/share/snmp

[root@localhost snmp]# snmpconf

The following installed configuration files were found:

1: ./snmpd.conf

2: ./snmptrapd.conf

3: /usr/local/share/snmp/snmpd.conf

4: /usr/local/share/snmp/snmptrapd.conf

Would you like me to read them in? Their content will be merged with the

output files created by this session.

Valid answer examples: "all", "none","3","1,2,5"

Read in which (default = all): none

I can create the following types of configuration files for you.

Select the file type you wish to create:

(you can create more than one as you run this program)

1: snmpd.conf

2: snmptrapd.conf

3: snmp.conf

Other options: quit

Select File: 1

The configuration information which can be put into snmpd.conf is divided into sections. Select a configuration section for snmpd.conf

that you wish to create:

1: Access Control Setup

2: Extending the Agent

3: Trap Destinations

4: Monitor Various Aspects of the Running Host

5: Agent Operating Mode

6: System Information Setup

Other options: finished

Select section: 1

Section: Access Control Setup

Description:

This section defines who is allowed to talk to your running

snmp agent.

Select from:

1: a SNMPv3 read-write user

2: a SNMPv3 read-only user

3: a SNMPv1/SNMPv2c read-only access community name

4: a SNMPv1/SNMPv2c read-write access community name

Other options: finished, list

Select section: 3

Configuring: rocommunity

Description:

a SNMPv1/SNMPv2c read-only access community name

arguments: community [default|hostname|network/bits] [oid]

The community name to add read-only access for: public

The hostname or network address to accept this community name from [RETURN for all]: The OID that this community should be restricted to [RETURN for no-restriction]:

Finished Output: rocommunity public

Section: Access Control Setup

Description:

This section defines who is allowed to talk to your running

snmp agent.

Select from:

1: a SNMPv3 read-write user

2: a SNMPv3 read-only user

3: a SNMPv1/SNMPv2c read-only access community name

4: a SNMPv1/SNMPv2c read-write access community name

Other options: finished, list

Select section: 4

Configuring: rwcommunity

Description:

a SNMPv1/SNMPv2c read-write access community name

arguments: community [default|hostname|network/bits] [oid]

Enter the community name to add read-write access for: private

The hostname or network address to accept this community name from [RETURN for all]: The OID that this community should be restricted to [RETURN for no-restriction]:

Finished Output: rwcommunity private

Section: Access Control Setup

Description:

This section defines who is allowed to talk to your running

snmp agent.

Select from:

1: a SNMPv3 read-write user

2: a SNMPv3 read-only user

3: a SNMPv1/SNMPv2c read-only access community name

4: a SNMPv1/SNMPv2c read-write access community name

Other options: finished, list

Select section: finished

The configuration information which can be put into snmpd.conf is divided into sections. Select a configuration section for snmpd.conf

that you wish to create:

1: Access Control Setup

2: Extending the Agent

3: Trap Destinations

4: Monitor Various Aspects of the Running Host

5: Agent Operating Mode

6: System Information Setup

Other options: finished

Select section: finished

I can create the following types of configuration files for you.

Select the file type you wish to create:

(you can create more than one as you run this program)

1: snmpd.conf

2: snmptrapd.conf

3: snmp.conf

Other options: quit

Select File: quit

Error: An snmpd.conf file already exists in this directory.

'overwrite', 'skip', 'rename' or 'append'? : overwrite

The following files were created:

snmpd.conf

These files should be moved to /usr/local/share/snmp if y ou

want them used by everyone on the system. In the future, if you add

the -i option to the command line I'll copy them there automatically for you.

Or, if you want them for your personal use only, copy them to

/root/.snmp . In the future, if you add the -p option to the

command line I'll copy them there automatically for you.

snmpd.conf配置文件

[root@localhost snmp]# pwd

/usr/local/share/snmp

[root@localhost snmp]# cat snmpd.conf

rocommunity public

rwcommunity private

[root@localhost snmp]#

编写MIB文件

[root@localhost snmp_c]# pwd

/root/snmp/test/snmp_c

[root@localhost snmp_c]# cat Inspur-MIB.my

-- Inspur-MIB.my

Inspur-MIB DEFINITIONS ::= BEGIN

IMPORTS

OBJECT-GROUP, MODULE-COMPLIANCE, NOTIFICATION-GROUP

FROM SNMPv2-CONF

enterprises, Integer32, Unsigned32, OBJECT-TYPE, MODULE-IDENTITY,

NOTIFICATION-TYPE

FROM SNMPv2-SMI

DisplayString

FROM SNMPv2-TC;

-- October 09, 2002 at 14:50 GMT

-- 1.3.6.1.4.1.37945

Test MODULE-IDENTITY

LAST-UPDATED "200210091450Z" -- October 09, 2002 at 14:50 GMT

ORGANIZATION

""

CONTACT-INFO

""

DESCRIPTION

"Video's Server MIB."

::= { enterprises 37945 }

-- Node definitions

-- This part will include all details about the Test.

-- 1.3.6.1.4.1.37945.1

Time OBJECT IDENTIFIER ::= { Test 1 }

-- 1.3.6.1.4.1.37945.1.1

GetTime OBJECT-TYPE

SYNTAX DisplayString (SIZE (0..100))

MAX-ACCESS read-only

STATUS current

DESCRIPTION

"Example : 2013/4/11"

::= { Time 1 }

END

-- Inspur-MIB.my

复制mib文件到指定目录

[root@localhost snmp_c]# cp Inspur-MIB.my /usr/local/share/snmp/mibs/ 测试mib文件

[root@localhost snmp_c]# snmptranslate -Tp -IR Inspur-MIB::Test

+--Test(37945)

|

+--Time(1)

|

+-- -R-- String GetTime(1)

Textual Convention: DisplayString

Size: 0..100

生成源码

[root@localhost snmp_c]# pwd

/root/snmp/test/snmp_c

[root@localhost snmp_c]# env MIBS="+/usr/local/share/snmp/mibs/Inspur-MIB.my" mib2c Test writing to -

mib2c has multiple configuration files depending on the type of

code you need to write. You must pick one depending on your need.

You requested mib2c to be run on the following part of the MIB tree:

OID: Test

numeric translation: .1.3.6.1.4.1.37945

number of scalars within: 1

number of tables within: 0

number of notifications within: 0

First, do you want to generate code that is compatible with the

ucd-snmp 4.X line of code, or code for the newer Net-SNMP 5.X code

base (which provides a much greater choice of APIs to pick from):

1) ucd-snmp style code

2) Net-SNMP style code

Select your choice : 2

********************************************************************** GENERATING CODE FOR SCALAR OBJECTS:

**********************************************************************

It looks like you have some scalars in the mib you requested, so I

will now generate code for them if you wish. You have two choices

for scalar API styles currently. Pick between them, or choose not

to generate any code for the scalars:

1) If you're writing code for some generic scalars

(by hand use: "mib2c -c mib2c.scalar.conf Test")

2) If you want to magically "tie" integer variables to integer

scalars

(by hand use: "mib2c -c mib2c.int_watch.conf Test")

3) Don't generate any code for the scalars

Select your choice: 1

using the mib2c.scalar.conf configuration file to generate your code.

writing to Test.h

writing to Test.c

**********************************************************************

* NOTE WELL: The code generated by mib2c is only a template. *YOU* *

* must fill in the code before it'll work most of the time. In many *

* cases, spots that MUST be edited within the files are marked with *

* /* XXX */ or /* TODO */ comments. *

********************************************************************** running indent on Test.h

running indent on Test.c

[root@localhost snmp_c]# ls

Inspur-MIB.my Test.c Test.h

修改测试程序Test.c

修改40-44行中的XXX：

case MODE_GET:

snmp_set_var_typed_value(requests->requestvb, ASN_OCTET_STR,

"hello inspur" /* XXX: a pointer to the scalar's data */,

strlen("hello inspur")/* XXX: the length of the data in bytes */);

break;

移动.c和.h文件

移动到源码目录agent/mibgroup/下

[root@localhost snmp_c]# cp Test.[ch] /root/snmp/net-snmp-5.7.2.1/agent/mibgroup/ 重新配置

进入源码目录重新configure，并增加参数--with-mib-modules=Test

[root@localhost net-snmp-5.7.2.1]# pwd

/root/snmp/net-snmp-5.7.2.1

[root@localhost net-snmp-5.7.2.1]# ./configure --with-mib-modules=Test

配置完成后从概要信息中能够看到自己的Test模块

---------------------------------------------------------

Net-SNMP configuration summary:

---------------------------------------------------------

SNMP Versions Supported: 1 2c 3

Building for: linux

Net-SNMP Version: 5.7.2.1

Network transport support: Callback Unix Alias TCP UDP IPv4Base SocketBase TCPBase UDPIPv4Base UDPBase

SNMPv3 Security Modules: usm

Agent MIB code: Test default_modules => snmpv3mibs mibII ucd_snmp notification notification-log-mib target agent_mibs agentx disman/event disman/schedule utilities host

MYSQL Trap Logging: unavailable

Embedded Perl support: enabled

SNMP Perl modules: building -- embeddable

SNMP Python modules: disabled

Crypto support from: crypto

Authentication support: MD5 SHA1

Encryption support: DES AES

Local DNSSEC validation: disabled

重新编译安装

[root@localhost net-snmp-5.7.2.1]# make && make install

开启另一个终端，启动snmpd服务

显示debug信息

[root@localhost snmp]# snmpd -f -Le -d

NET-SNMP version 5.7.2.1

回到原来终端，执行测试程序，发送get请求

[root@localhost snmp_c]# snmpget -v2c -c public localhost .1.3.6.1.4.1.37945.1.1.0

SNMPv2-SMI::enterprises.37945.1.1.0 = STRING: "hello inspur"

查看原来终端的debug信息

[root@localhost ~]# snmpd -Le -f -d

NET-SNMP version 5.7.2.1

Received 46 byte packet from UDP: [127.0.0.1]:34999->[127.0.0.1]:161 0000: 30 2C 02 01 01 04 06 70 75 62 6C 69 63 A0 1F 02 0,.....public... 0016: 04 2E 76 25 8B 02 01 00 02 01 00 30 11 30 0F 06 ..v%.......0.0.. 0032: 0B 2B 06 01 04 01 82 A8 39 01 01 00 05 00 .+......9.....

Sending 58 bytes to UDP: [127.0.0.1]:34999->[127.0.0.1]:161

0000: 30 38 02 01 01 04 06 70 75 62 6C 69 63 A2 2B 02 08.....public.+. 0016: 04 2E 76 25 8B 02 01 00 02 01 00 30 1D 30 1B 06 ..v%.......0.0.. 0032: 0B 2B 06 01 04 01 82 A8 39 01 01 00 04 0C 68 65 .+......9.....he 0048: 6C 6C 6F 20 69 6E 73 70 75 72 llo inspur