Programming using the net-snmp API

A Redback sms10000 Access Server is used in a project. As an additional requirement, an SNMP interface program is required to send a subscriber Reauth snmp package to the access server;
Because there are relatively few SNMP routines, we will make a note and record the SNMP-related part in this cut-down program.
The program uses the net-snmp API, so the system must install net-snmp in advance;
During compilation, use the line command to bring netsnmp:
Gcc-O redweb. C-lkstat-lm-lsocket-ladm-lnetsnmp-lcrypto
Don't be more arrogant. They are all written in the program. The so-called knowledge has no value.
Static char snmpreauth [] = ". 1.3.6.1.4.1.2352.2.14.1.2.1.1 .";
Struct snmp_session session, * ss;
Struct snmp_pdu * response;
Struct snmp_pdu * PDU;
Char snmpcommunity [32];
Char snmpstr [256];
Char tmpstr [128];
Char * endptr;
Oid name [512];
Int name_length;
Int CNT, id = 0;
Int snmpsetvalue = 1;
Init_mib ();
Add_mibdir ("/opt/weblogin/mibs ");
// Include Redback mibs File
Snmp_sess_init (& session );
Session. Version = snmp_version_1;
Session. peername = strdup (data. nas_address );
Session. Community = strdup (snmpcommunity );
Session. community_len = strlen (session. Community );
Session. retries = 0;
Session. Timeout = 12000;
Session. sessid = strtol (data. timeid, & endptr, 0 );
Sock_startup;
/* Macro
* Open an SNMP session
*/
Ss = snmp_open (& session );
If (Ss = NULL ){
/*
* Diagnose snmp_open errors with the input netsnmp_session pointer
*/
Snmp_sess_perror ("snmptable", & session );
Sock_cleanup;
}
/*
* Create PDU for Set Request and add object names and values to request
*/
PDU = (struct snmp_pdu *) snmp_pdu_create (snmp_msg_set );
If (PDU = NULL)
{
Printf ("unable to create the PDU ");
}
Sprintf (snmpstr, "% S17", snmpreauth );
For (CNT = 0; CNT <17; CNT ++)
{
Sprintf (tmpstr, ". % d", (char *) data. session_id [CNT]);
// Data. session_id Mac Format String
Strcat (snmpstr, tmpstr );
}
// Fixme
Name_length = 512;
If (! Read_objid (snmpstr, name, & name_length )){
Printf ("error in read_objid ");
Exit (1 );
};
Snmp_pdu_add_variable (PDU, name, name_length, asn_integer,
& Snmpsetvalue, sizeof (snmpsetvalue ));
Status = snmp_synch_response (SS, PDU, & response );
// Sync SNMP
If (status = stat_success ){
If (response-> errstat = snmp_err_noerror ){
}
Exitval = 2;
} Else if (status = stat_timeout ){
　　
　　
Fprintf (stderr, "SNMP Timeout: no response from % s ",
Session. peername );
Exitval = 1;
} Else {
Snmp_sess_perror ("snmpset", SS );
Printf ("SNMP session else ");
Exitval = 1;
}
If (response)
Snmp_free_pdu (response );
Snmp_close (SS );
Sock_cleanup;
/* Macro off
* Final a snmp session
*/