问题
I have made a private MIB - RASP-MIB.
Here is the mib
RASP-MIB DEFINITIONS ::= BEGIN
IMPORTS
OBJECT-TYPE, MODULE-IDENTITY,enterprises FROM SNMPv2-SMI
TEXTUAL-CONVENTION FROM SNMPv2-TC;
rasp MODULE-IDENTITY
LAST-UPDATED "201804210000Z" -- 21 April 2018, midnight
ORGANIZATION "net-snmp"
CONTACT-INFO "postal: ABC HELLO
CHECK 512310
email: net-snmp-coders@lists.sourceforge.net"
DESCRIPTION "A simple mib for Raspberry PI information gathering."
::={enterprises 9100}
RowStatus ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"The RowStatus textual convention is used to manage the
creation and deletion of conceptual rows, and is used as the
value of the SYNTAX clause for the status column of a
conceptual row."
SYNTAX INTEGER {
-- the following two values are states:
-- these values may be read or written
active(1), -- state: read/write
notInService(2), -- state: read/write
notReady(3), -- state: read only
createAndGo(4), -- action: write only
createAndWait(5), -- action: write only
destroy(6) -- action: write only
}
raspScalar OBJECT IDENTIFIER ::= {rasp 1}
raspTable OBJECT IDENTIFIER ::= {rasp 2}
freeSpaceAvailable OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-write
STATUS current
DESCRIPTION "The free space available in the system in MB"
DEFVAL { 2 }
::= { raspScalar 1 }
scalar2 OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-write
STATUS current
DESCRIPTION "scalar2"
DEFVAL { 4 }
::= { raspScalar 2 }
raspTableOne OBJECT-TYPE
SYNTAX SEQUENCE OF raspTable1Entry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION "Table 1"
::= { raspTable 1 }
raspTable1Entry OBJECT-TYPE
SYNTAX raspTable1Entry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION "Entry"
INDEX { tIndex }
::= { raspTableOne 1 }
raspTable1Entry ::= SEQUENCE {
tIndex Integer32,
tName DisplayString,
tMarks Integer32,
tRowStatus INTEGER
}
tIndex OBJECT-TYPE
SYNTAX Integer32 (1..100)
MAX-ACCESS read-only
STATUS current
DESCRIPTION "Index for Table 1"
::= { raspTable1Entry 1 }
tName OBJECT-TYPE
SYNTAX DisplayString
MAX-ACCESS read-create
STATUS current
DESCRIPTION "Name for Table 1"
::= { raspTable1Entry 2 }
tMarks OBJECT-TYPE
SYNTAX Integer32(1..100)
MAX-ACCESS read-create
STATUS current
DESCRIPTION "Marks for Table 1"
::= { raspTable1Entry 3 }
tRowStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION "The status"
::= { raspTable1Entry 4 }
END
Next,This mib has a scalar object - freeSpaceAvailable. I am trying to use this one.
1) First I translated this using snmptranslate
$snmptranslate -m +RASP-MIB -IR -On freeSpaceAvailable
.1.3.6.1.4.1.9100.1.1
2) Next, I have generated mib2c code -
env MIBS="+RASP-MIB" mibc2c freeSpaceAvailable
3) Next, I have modified this file to return a hardcoded value
4) Compiled it as subAgent
$net-snmp-config --compile-subagent mysubagent freeSpaceAvailable.c
5) Started snmp daemon
sudo service snmpd start
6) tested whether it is working or not
snmpwalk localhost -c public -v1
7) Running my sub-agent
$./mysubagent &
$pidof mysubagent
27709
Now, not sure why do I get this problem?
$snmpget -v 1 -c public localhost .1.3.6.1.4.1.9100.1.1
Error in packet
Reason: (noSuchName) There is no such variable name in this MIB.
Failed object: iso.3.6.1.4.1.9100.1.1
Here is the screen shot -
Here is the freeSpaceAvailable.c code
/*
* Note: this file originally auto-generated by mib2c using
* $
*/
#include <net-snmp/net-snmp-config.h>
#include <net-snmp/net-snmp-includes.h>
#include <net-snmp/agent/net-snmp-agent-includes.h>
#include "freeSpaceAvailable.h"
static unsigned long myVarUlong = 0;
/** Initializes the freeSpaceAvailable module */
void
init_freeSpaceAvailable(void)
{
const oid freeSpaceAvailable_oid[] =
{ 1, 3, 6, 1, 4, 1, 9100, 1, 1 };
DEBUGMSGTL(("freeSpaceAvailable", "Initializing\n"));
netsnmp_register_scalar(netsnmp_create_handler_registration
("freeSpaceAvailable",
handle_freeSpaceAvailable,
freeSpaceAvailable_oid,
OID_LENGTH(freeSpaceAvailable_oid),
HANDLER_CAN_RWRITE));
}
int
handle_freeSpaceAvailable(netsnmp_mib_handler *handler,
netsnmp_handler_registration *reginfo,
netsnmp_agent_request_info *reqinfo,
netsnmp_request_info *requests)
{
int ret = -1;
/*
* 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.
*/
switch (reqinfo->mode) {
case MODE_GET:
snmp_set_var_typed_value(requests->requestvb, ASN_INTEGER, &myVarUlong,sizeof(myVarUlong) );
break;
/*
* SET REQUEST
*
* multiple states in the transaction. See:
* http://www.net-snmp.org/tutorial-5/toolkit/mib_module/set-actions.jpg
*/
case MODE_SET_RESERVE1:
/*
* or you could use netsnmp_check_vb_type_and_size instead
*/
ret = netsnmp_check_vb_type(requests->requestvb, ASN_INTEGER);
if (ret != SNMP_ERR_NOERROR) {
netsnmp_set_request_error(reqinfo, requests, ret);
}
break;
case MODE_SET_RESERVE2:
/*
* XXX malloc "undo" storage buffer
*/
//if ( /* XXX if malloc, or whatever, failed: */ ) {
// netsnmp_set_request_error(reqinfo, requests,
// SNMP_ERR_RESOURCEUNAVAILABLE);
// }
break;
case MODE_SET_FREE:
/*
* XXX: free resources allocated in RESERVE1 and/or
* RESERVE2. Something failed somewhere, and the states
* below won't be called.
*/
break;
case MODE_SET_ACTION:
/*
* XXX: perform the value change here
*/
myVarUlong = (unsigned long)*requests->requestvb->val.integer;
if ( myVarUlong == 0 ) {
netsnmp_set_request_error(reqinfo, requests, ret
);
}
break;
case MODE_SET_COMMIT:
/*
* XXX: delete temporary storage
*/
//if ( /* XXX: error? */ ) {
/*
* try _really_really_ hard to never get to this point
*/
// netsnmp_set_request_error(reqinfo, requests,
// SNMP_ERR_COMMITFAILED);
// }
break;
case MODE_SET_UNDO:
/*
* XXX: UNDO and return to previous value for the object
*/
#if 0
if ( /* XXX: error? */ ) {
/*
* try _really_really_ hard to never get to this point
*/
netsnmp_set_request_error(reqinfo, requests,
SNMP_ERR_UNDOFAILED);
}
#endif
break;
default:
/*
* we should never get here, so this is a really bad error
*/
snmp_log(LOG_ERR,
"unknown mode (%d) in handle_freeSpaceAvailable\n",
reqinfo->mode);
return SNMP_ERR_GENERR;
}
return SNMP_ERR_NOERROR;
}
It seems like main SNMP daemon doesn't get notified at all. I have added a debug information in
/etc/default/snmpd
SNMPDOPTS='-LS 0-4 d -Lf /dev/null -u snmp -g snmp -I -smux,mteTrigger,mteTriggerConf -p /var/run/snmpd.pid'
in the syslog -
sudo tail -f /var/log/syslog
Apr 23 16:00:17 pc snmpd[11340]: /etc/snmp/snmpd.conf: line 143: Warning: Unknown token: defaultMonitors.
Apr 23 16:00:17 pc snmpd[11340]: /etc/snmp/snmpd.conf: line 145: Warning: Unknown token: linkUpDownNotifications.
Apr 23 16:00:17 pc snmpd[11340]: /var/lib/snmp/snmpd.conf: line 32: Warning: Unknown token: _mteTTable.
Apr 23 16:00:17 pc snmpd[11340]: /var/lib/snmp/snmpd.conf: line 33: Warning: Unknown token: _mteTTable.
Apr 23 16:00:17 pc snmpd[11340]: /var/lib/snmp/snmpd.conf: line 34: Warning: Unknown token: _mteTTable.
Apr 23 16:00:17 pc snmpd[11340]: /var/lib/snmp/snmpd.conf: line 35: Warning: Unknown token: _mteTTable.
Apr 23 16:00:17 pc snmpd[11340]: /var/lib/snmp/snmpd.conf: line 36: Warning: Unknown token: _mteTTable.
Apr 23 16:00:17 pc snmpd[11340]: /var/lib/snmp/snmpd.conf: line 37: Warning: Unknown token: _mteTTable.
Apr 23 16:00:17 pc snmpd[11340]: /var/lib/snmp/snmpd.conf: line 38: Warning: Unknown token: _mteTTable.
Even if I kill or spawn the mysubagent, it doesn't make any difference.
回答1:
There's an small bug in the node definition. It should be ::= { raspScalar 1 }
freeSpaceAvailable OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-write
STATUS current
DESCRIPTION "The free space available in the system in MB"
DEFVAL { 2 }
::= { raspScalar 1 }
I used tkmib (linux) to troubleshoot the issue.
Following this tutorial, I was able to get good responses
c code fragment:
int fSpace;
// inside init_freeSpaceAvailable
fSpace = (int) random();
// inside switch statement
case MODE_GET:
snmp_set_var_typed_value(requests->requestvb, ASN_INTEGER,
(u_char *)&fSpace,
sizeof(fSpace));
break;
on /etc/snmp/snmpd.conf add
master agentx
start snmpd as
sudo snmpd -f -Lo -C --rwcommunity=public --master=agentx --agentXSocket=tcp:localhost:1705
start agent as
./mysubagent -f -Lo -x tcp:localhost:1705
Test as
snmpget -v 1 -c public localhost RASP-MIB::freeSpaceAvailable.0
RASP-MIB::freeSpaceAvailable.0 = INTEGER: 924855091
or by OID
snmpget -v 1 -c public -m "+RASP-MIB" localhost 1.3.6.1.4.1.9100.1.1.0
RASP-MIB::freeSpaceAvailable.0 = INTEGER: 924855091
来源：https://stackoverflow.com/questions/49971904/error-nosuchname-there-is-no-such-variable-name-in-this-mib-netsnmp