Example of UCD-SNMP code (1)

After learning the SNMP protocol, we then perform an instance operation on the UCD-SNMP software. So we have already talked about some basic content about this software. The following network management program will be analyzed in detail.

A simple SNMP Network Management Program

Next, let's first use ucd-snmp to write an SNMP Network Program, and try to use this software package from the application perspective. this program is so simple that it does not support any command line parameters. It only obtains the system description from the agent.

The program code is as follows:

1) /* snmpapp.c - a simple SNMP application */
2) #include <ucd-snmp/ucd-snmp-config.h>;
3) #include <ucd-snmp/ucd-snmp-includes.h>;
4) #include <ucd-snmp/system.h>; 
5) int main(int argc, char * argv[])
6) {
7) struct snmp_session session, *ss;
8) struct snmp_pdu *request, *response;
9) 
10) oid myoid[MAX_OID_LEN];
11) size_t myoid_len = MAX_OID_LEN;
12) struct variable_list *vars;
13) int status;
14) init_snmp("snmpapp");
15) snmp_sess_init( &session );
16) session.version = SNMP_VERSION_1; 
17) session.peername = "localhost";
18) session.community = "public";
19) session.community_len = strlen(session.community);
20) SOCK_STARTUP;
21) ss = snmp_open(&session);
22) request = snmp_pdu_create(SNMP_MSG_GET);
23) read_objid("system.sysDescr.0", myoid, &myoid_len);
24) snmp_add_null_var(request, myoid, myoid_len);
25) status = snmp_synch_response(ss, request, &response);
26) if (status == STAT_SUCCESS && 
27) response->;errstat == SNMP_ERR_NOERROR)
28) {
29) for(vars = response->;variables; vars; vars = vars->;next_variable)
30) print_variable(vars->;name, vars->;name_length, vars);
31) } else {
32) if (status == STAT_SUCCESS)
33) fprintf(stderr, "Error in packet\nReason: %s\n",
34) snmp_errstring(response->;errstat));
35) else
36) snmp_sess_perror("snmpget", ss);
37) }
38) if (response)
39) snmp_free_pdu(response);
40) snmp_close(ss);
41) SOCK_CLEANUP;
42) return (0);
43) }