Test-MIB.txt

-- Test-MIB.my
	Test-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
		-- 1.3.6.1.4.1.16535
		Test MODULE-IDENTITY
			LAST-UPDATED "200210091450Z" -- October 09, 2002 at 14:50 GMT
			ORGANIZATION
				""
			CONTACT-INFO
				""
			DESCRIPTION
				"Video's Server MIB."
			::= { enterprises 16535 }

-- Node definitions
-- This part will include all details about the Test.
		-- 1.3.6.1.4.1.16535.1
		Time OBJECT IDENTIFIER ::= { Test 1 }

		-- 1.3.6.1.4.1.16535.1.1
		GetTime OBJECT-TYPE
			SYNTAX DisplayString (SIZE (0..100))
			MAX-ACCESS read-only
			STATUS current
			DESCRIPTION
				"Example : 2013/4/11"
			::= { Time 1 }
	END

-- Test-MIB.my

Test.c

#include <net-snmp/net-snmp-config.h>
#include <net-snmp/net-snmp-includes.h>
#include <net-snmp/agent/net-snmp-agent-includes.h>
#include "Test.h"
#include <time.h>

/** Initializes the Test module */
void
init_Test(void)
{
	oid GetTime_oid[] = { 1, 3, 6, 1, 4, 1, 16535, 1, 1 };

	DEBUGMSGTL(("Test", "Initializing\n"));

	netsnmp_register_scalar(netsnmp_create_handler_registration
							("GetTime", handle_GetTime, GetTime_oid,
							OID_LENGTH(GetTime_oid), HANDLER_CAN_RONLY));
}

int
handle_GetTime(netsnmp_mib_handler *handler,
				netsnmp_handler_registration *reginfo,
				netsnmp_agent_request_info *reqinfo,
				netsnmp_request_info *requests)
{
	/*
	 * We are never called for a GETNEXT if it's registered as a
	 * "instance", as it's "magically" handled for us.
	 */
	/*
	 * a instance handler also only hands us one request at a time, so
	 * we don't need to loop over a list of requests; we'll only get one.
	 */

	time_t t;

	switch (reqinfo->mode) {
	case MODE_GET:
		time(&t);
		char szTime[100];
		snprintf(szTime, sizeof(szTime), "%s", ctime(&t));
		snmp_set_var_typed_value(requests->requestvb, ASN_OCTET_STR,
								/*
								 * XXX: a pointer to the scalar's data
								 */ (unsigned char *)szTime,
								/*
								 * XXX: the length of the data in bytes
								 */ strlen(szTime));
		break;

	default:
		/*
		 * we should never get here, so this is a really bad error
		 */
		snmp_log(LOG_ERR, "unknown mode (%d) in handle_GetTime\n",
			reqinfo->mode);

		return SNMP_ERR_GENERR;
	}

	return SNMP_ERR_NOERROR;
}

static int keep_running = 1;

RETSIGTYPE stop_server(int __attribute__((unused)) a) {
	keep_running = 0;
}

int main()
{
	int agentx_subagent=1; /* change this if you want to be a SNMP master agent */
	int background = 0; /* change this if you want to run in the background */
	int syslog = 1; /* change this if you want to use syslog */
	const char *app_name = "Test";

	/* print log errors to syslog or stderr */
	if (syslog)
		snmp_enable_calllog();
	else
		snmp_enable_stderrlog();

	/* we're an agentx subagent? */
	if (agentx_subagent) {
		/* make us a agentx client. */
		netsnmp_ds_set_boolean(NETSNMP_DS_APPLICATION_ID, NETSNMP_DS_AGENT_ROLE, 1);
	}
	
	/* run in background, if requested */
	if (background && netsnmp_daemonize(1, !syslog)) {
		exit(1);
	}
	
	/* initialize tcpip, if necessary */
	SOCK_STARTUP;
  
	/* initialize the agent library */
	init_agent(app_name);

	/* initialize your mib code here */
	init_Test();

	/* initialize vacm/usm access control  */
	//if (!agentx_subagent) {
	//	init_vacm_vars();
	//	init_usmUser();
	//}
  
	/* Test will be used to read Test.conf files. */
	init_snmp("Test");
	
	/* If we're going to be a snmp master agent, initial the ports */
	if (!agentx_subagent) {
		init_master_agent();  /* open the port to listen on (defaults to udp:161) */
	}
	
	/* In case we recevie a request to stop (kill -TERM or kill -INT) */
	keep_running = 1;

	while (keep_running) {
		/* if you use select(), see snmp_select_info() in snmp_api(3) */
		/*     --- OR ---  */
		agent_check_and_process(1);/* block every 1 second */
	}

	/* at shutdown time */
	snmp_shutdown(app_name);

	/* deinitialize your mib code here */

	/* shutdown the agent library */
	//shutdown_agent();
	SOCK_CLEANUP;
	
	return 0;
}

Test.h

/*
 * Note: this file originally auto-generated by mib2c using
 * $
 */
#ifndef TEST_H
#define TEST_H

/*
 * function declarations
 */
void init_Test(void);
Netsnmp_Node_Handler handle_GetTime;

#endif /* TEST_H */

test.sh

#!/bin/sh
#

gcc -fno-strict-aliasing -g -O2 -Ulinux -Dlinux=linux -D_REENTRANT \
        -D_GNU_SOURCE -fno-strict-aliasing -pipe -Wdeclaration-after-statement \
        -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 \
        -I/usr/include/gdbm -I/usr/lib64/perl5/5.8.8/x86_64-linux-thread-multi/CORE -I. \
        -I/usr/local/include -o Test Test.c -L/usr/local/lib -lnetsnmp -lnetsnmpmibs -lnetsnmpagent \
        -Wl,-E -Wl,-rpath,/usr/lib64/perl5/5.8.8/x86_64-linux-thread-multi/CORE -lnetsnmp -lcrypto