Im trying to implement agent trap v3 sender using net-snmp.
currently my status is im able to start snmpd and daemon is sending coldstart trap to host defined in snmpd.conf
my snmpd.conf:
createUser myuser SHA "12345678" AES
rouser myuser auth
trapsess -v 3 -u myuser -n contextname -l authPriv -a SHA -A 12345678 -x AES - X 12345678 host_ip:162
group groupv3 usm myuser
## incl/excl subtree mask
view all included .1 80
access groupv3 "" any auth exact all all all
var/net-snmp/snmpd.conf contain the hash user, if im using snmptrap command in linux i can see the trap recived by host with wireshark sniffer.
But im unable to send traps from code (im restricted to C, embedded system). im using send_v2trap() api, and when im defined vars list nothing is sent out. im not sure what i need to define, do i need to open session or snmpd.conf file is enough? what i need to define to send trap via code?
i tried to use some examples provided with no luck
this is one of them:
int
write_exampletrap2(int action,
u_char * var_val,
u_char var_val_type,
size_t var_val_len,
u_char * statP, oid * name, size_t name_len)
{
long intval;
/*
* these variales will be used when we send the trap
*/
oid objid_snmptrap[] = { 1, 3, 6, 1, 6, 3, 1, 1, 4, 1, 0 }; /* snmpTrapOID.0 */
oid demo_trap[] = { 1, 3, 6, 1, 4, 1, 2021, 13, 990 }; /*demo-trap */
oid example_string_oid[] =
{ 1, 3, 6, 1, 4, 1, 2021, 254, 1, 0 };
static netsnmp_variable_list var_trap;
static netsnmp_variable_list var_obj;
DEBUGMSGTL(("example", "write_exampletrap2 entered: action=%d\n",
action));
switch (action) {
case RESERVE1:
/*
* The only acceptable value is the integer 1
*/
if (var_val_type != ASN_INTEGER) {
DEBUGMSGTL(("example", "%x not integer type", var_val_type));
return SNMP_ERR_WRONGTYPE;
}
if (var_val_len > sizeof(long)) {
DEBUGMSGTL(("example", "wrong length %" NETSNMP_PRIz "u",
var_val_len));
return SNMP_ERR_WRONGLENGTH;
}
intval = *((long *) var_val);
if (intval != 1) {
DEBUGMSGTL(("example", "wrong value %lx", intval));
return SNMP_ERR_WRONGVALUE;
}
break;
case RESERVE2:
/*
* No resources are required....
*/
break;
case FREE:
/*
* ... so no resources need be freed
*/
break;
case ACTION:
/*
* Having triggered the sending of a trap,
* it would be impossible to revoke this,
* so we can't actually invoke the action here.
*/
break;
case UNDO:
/*
* We haven't done anything yet,
* so there's nothing to undo
*/
break;
case COMMIT:
/*
* Everything else worked, so it's now safe
* to trigger the trap.
* Note that this is *only* acceptable since
* the trap sending routines are "failsafe".
* (In fact, they can fail, but they return no
* indication of this, which is the next best thing!)
*/
/*
* trap definition objects
*/
var_trap.next_variable = &var_obj; /* next variable */
var_trap.name = objid_snmptrap; /* snmpTrapOID.0 */
var_trap.name_length = sizeof(objid_snmptrap) / sizeof(oid); /* number of sub-ids */
var_trap.type = ASN_OBJECT_ID;
var_trap.val.objid = demo_trap; /* demo-trap objid */
var_trap.val_len = sizeof(demo_trap); /* length in bytes (not number of subids!) */
/*
* additional objects
*/
var_obj.next_variable = NULL; /* No more variables after this one */
var_obj.name = example_string_oid;
var_obj.name_length = sizeof(example_string_oid) / sizeof(oid); /* number of sub-ids */
var_obj.type = ASN_OCTET_STR; /* type of variable */
var_obj.val.string = (unsigned char *) example_str; /* value */
var_obj.val_len = strlen(example_str);
DEBUGMSGTL(("example", "write_exampletrap2 sending the v2 trap\n"));
send_v2trap(&var_trap);
DEBUGMSGTL(("example", "write_exampletrap2 v2 trap sent\n"));
break;
}
return SNMP_ERR_NOERROR;
}
any help or example will be very appreciated
Thanks in advance
