Net-SNMP development snmpget for Simple Network Protocol snmp

Objective: To obtain desired information from the snmp Agent device through the development of the net-snmp snmpget source code

Prepare: Download The net-snmp-5.6.1.1.tar.gzsource code package from http://www.net-snmp.org/net.

 

Development Process:

1. decompress the source code

2. Go to the directory for extracting the source code.

1) Run./configure -- prefix =/usr/local/net-snmp
(Type "./configure -- help" for a quick usage summary .)
(-- Prefix = PATH will change the default/usr/local installation path .)
(See "Compilers and Options" on changing the compiler to use)

2) make

3) make install

3. installation is complete

The content under/usr/local/net-snmp is as follows:

Root @ an-virtual-machine:/usr/local/net-snmp # ls
Bin include lib sbin share

Go to lib and you will see the following content:

Root @ an-virtual-machine:/usr/local/net-snmp/lib # ls
Libnetsnmp. a libnetsnmpmibs. la
Libnetsnmpagent. a libnetsnmpmibs. so
Libnetsnmpagent. la libnetsnmpmibs. so.25
Libnetsnmpagent. so libnetsnmpmibs. so.25.0.2
Libnetsnmpagent. so.25 libnetsnmp. so
Libnetsnmpagent. so.25.0.2 libnetsnmp. so.25
Libnetsnmphelpers. a libnetsnmp. so.25.0.2
Libnetsnmphelpers. la libnetsnmptrapd.
Libnetsnmphelpers. so libnetsnmptrapd. la
Libnetsnmphelpers. so.25 libnetsnmptrapd. so
Libnetsnmphelpers. so.25.0.2 libnetsnmptrapd. so.25
Libnetsnmp. la libnetsnmptrapd. so.25.0.2
Libnetsnmpmibs.

4. Create a project TestNetSNMp in Qtcreator.

Put libnetsnmp. a In the above lib under the project

Add the following content to. pro:
INCLUDEPATH + =/usr/local/net-snmp/include

LIBS + =-L/root/wyz/TestNetSNMP-lnetsnmp

 

5. Add the code in main as follows:

#include <net-snmp/net-snmp-config.h>#if HAVE_STDLIB_H#include <stdlib.h>#endif#if HAVE_UNISTD_H#include <unistd.h>#endif#if HAVE_STRING_H#include <string.h>#else#include <strings.h>#endif#include <sys/types.h>#if HAVE_NETINET_IN_H#include <netinet/in.h>#endif#include <stdio.h>#include <ctype.h>#if TIME_WITH_SYS_TIME# ifdef WIN32#  include <sys/timeb.h># else#  include <sys/time.h># endif# include <time.h>#else# if HAVE_SYS_TIME_H#  include <sys/time.h># else#  include <time.h># endif#endif#if HAVE_SYS_SELECT_H#include <sys/select.h>#endif#if HAVE_WINSOCK_H#include <winsock.h>#endif#if HAVE_NETDB_H#include <netdb.h>#endif#if HAVE_ARPA_INET_H#include <arpa/inet.h>#endif#include <net-snmp/utilities.h>#include <net-snmp/net-snmp-includes.h>#include <vector>#include <map>#include <iostream>using namespace  std;#define NETSNMP_DS_APP_DONT_FIX_PDUS 0 string fprint_variable_1(const oid * objid,size_t objidlen, const netsnmp_variable_list * variable){    u_char         *buf = NULL;    size_t          buf_len = 256, out_len = 0;    if ((buf = (u_char *) calloc(buf_len, 1)) == NULL) {                return "";    } else {        if (sprint_realloc_variable(&buf, &buf_len, &out_len, 1,                                    objid, objidlen, variable)) {            string strTemp((char*)buf);                        int iFirst=strTemp.find_first_of(":");            string strInfo=strTemp.substr(iFirst,strTemp.length()-1);                        return strInfo;                    } else {            fprintf(stdout, "%s [TRUNCATED]\n", buf);        }    }    SNMP_FREE(buf);}string fprint_variable_2(const oid * objid,size_t objidlen, const netsnmp_variable_list * variable){    u_char         *buf = NULL;    size_t          buf_len = 256, out_len = 0;    if ((buf = (u_char *) calloc(buf_len, 1)) == NULL) {                return "";    } else {        if (sprint_realloc_variable(&buf, &buf_len, &out_len, 1,                                    objid, objidlen, variable)) {            string strTemp((char*)buf);                        return strTemp;                    } else {            fprintf(stdout, "%s [TRUNCATED]\n", buf);        }    }    SNMP_FREE(buf);}string SnmpGet(char *community,char *ip,char *oid_array)//snmpget -v2c -c public 10.0.0.11 1.3.6.1.2.1.1.5.0{    netsnmp_session session, *ss=(netsnmp_session*)malloc(sizeof(netsnmp_session));    netsnmp_pdu    *response=(netsnmp_pdu*)malloc(sizeof(netsnmp_pdu));        netsnmp_variable_list *vars=NULL;    netsnmp_pdu    *pdu;        if(!ss)        ss = (netsnmp_session*)malloc(sizeof(netsnmp_session));    if(!response)        response=(netsnmp_pdu*)malloc(sizeof(netsnmp_pdu));            int             count;    int             current_name = 0;    char           *names[SNMP_MAX_CMDLINE_OIDS];    oid             name[MAX_OID_LEN];    size_t          name_length;    int             status;    int             failures = 0;    int             exitval = 0;        snmp_sess_init(&session);        session.version = SNMP_VERSION_2c;        session.peername = ip;    session.community = (unsigned char*)community;    session.community_len = strlen(community);            names[0] = oid_array;    current_name = 1;        SOCK_STARTUP;        snmp_close(ss);    ss = snmp_open(&session);        if (ss == NULL) {        snmp_sess_perror("snmpget", &session);        SOCK_CLEANUP;        return "";    }        pdu = snmp_pdu_create(SNMP_MSG_GET);    for (count = 0; count < current_name; count++) {        name_length = MAX_OID_LEN;        if (!snmp_parse_oid(names[count], name, &name_length)) {            snmp_perror(names[count]);            failures++;        }        else        {            snmp_add_null_var(pdu, name, name_length);        }    }    if (failures) {        snmp_close(ss);        SOCK_CLEANUP;        return "";    }        retry:    status = snmp_synch_response(ss, pdu, &response);    if (status == STAT_SUCCESS) {        if (response->errstat == SNMP_ERR_NOERROR)        {               vars = response->variables;                        string strTemp=fprint_variable_1(vars->name, vars->name_length, vars);                        return strTemp;        }        else        {            printf("2\n");            fprintf(stderr, "Error in packet\nReason: %s\n",                    snmp_errstring(response->errstat));                        if (response->errindex != 0) {                fprintf(stderr, "Failed object: ");                for (count = 1, vars = response->variables;                     vars && count != response->errindex;                     vars = vars->next_variable, count++)                    /*EMPTY*/;                if (vars) {                    fprint_objid(stderr, vars->name, vars->name_length);                }                fprintf(stderr, "\n");            }            exitval = 2;                                    if (!netsnmp_ds_get_boolean(NETSNMP_DS_APPLICATION_ID,                                        NETSNMP_DS_APP_DONT_FIX_PDUS)) {                pdu = snmp_fix_pdu(response, SNMP_MSG_GET);                snmp_free_pdu(response);                response = NULL;                if (pdu != NULL) {                    goto retry;                }            }        }                       /* endif -- SNMP_ERR_NOERROR */            } else if (status == STAT_TIMEOUT) {        fprintf(stderr, "Timeout: No Response from %s.\n",                session.peername);        exitval = 1;            } else {                    /* status == STAT_ERROR */        snmp_sess_perror("snmpget", ss);        exitval = 1;            }                           /* endif -- STAT_SUCCESS */            if (response)        snmp_free_pdu(response);    snmp_close(ss);        SOCK_CLEANUP;        return "";}   int main(){    string strSnmpInfo;    //    strSnmpInfo=SnmpGet("2c","public","192.168.1.241",".1.3.6.1.4.1.11.2.3.9.1.1.7.0");    //    strSnmpInfo=SnmpGet("2c","public","192.168.1.241",".1.3.6.1.2.1.1.1.0");    strSnmpInfo=SnmpGet("public","192.168.1.133","1.3.6.1.2.1.1.1.0");          cout<<"wyz---------------snmpInfo::"<<strSnmpInfo<<endl;    return 0;}

 

The running result is as follows:

Root @ an-virtual-machine :~ /Wyz/TestNetSNMP-build-desktop #./TestNetSNMP
Wyz --------------- snmpInfo: "Linux an-virtual-machine 2.6.35-22-generic # 33-Ubuntu SMP Sun Sep 19 20:34:50 UTC 2010 i686"