# coding: utf-8
# This file is part of PacketGen
# See https://github.com/sdaubert/packetgen for more informations
# Copyright (C) 2016 Sylvain Daubert <sylvain.daubert@laposte.net>
# This program is published under MIT license.
module PacketGen
module Header
# Dissect error
class DissectError < ParseError; end
# Simple Network Management Protocol (SNMP)
# @author Sylvain Daubert
# @since 2.0.0
class SNMP < ASN1Base
# Agents listen to this port
UDP_PORT1 = 161
# Configuration sinks listen to this port
UDP_PORT2 = 162
PDU_GET = 0
PDU_NEXT = 1
PDU_RESPONSE = 2
PDU_SET = 3
PDU_TRAPv1 = 4
PDU_BULK = 5
PDU_INFORM = 6
PDU_TRAPv2 = 7
PDU_REPORT = 8
ERRORS = { 'no_error' => 0,
'too_big' => 1,
'no_such_name' => 2,
'bad_value' => 3,
'read_only' => 4,
'generic_error' => 5,
'no_access' => 6,
'wrong_type' => 7,
'wrong_length' => 8,
'wrong_encoding' => 9,
'wrong_value' => 10,
'no_creation' => 11,
'inconsistent_value' => 12,
'ressource_unavailable' => 13,
'commit_failed' => 14,
'undo_failed' => 15,
'authorization_error' => 16,
'not_writable' => 17,
'inconsistent_name' => 18
}
# Class to handle SNMP VarBind
# VarBind ::= SEQUENCE {
# name OBJECT IDENTIFIER,
# value ANY -- depends on name
# }
# @author Sylvain Daubert
class VarBind < RASN1::Model
sequence :varbind,
content: [objectid(:name),
any(:value)]
end
# Class to handle SNMP VariableBindingsList
# VarBindList ::= SEQUENCE (SIZE (0..max-bindings)) OF VarBind
# @author Sylvain Daubert
class VariableBindings < RASN1::Model
sequence_of :bindings, VarBind
end
# Class to handle GetRequest PDU
# GetRequest-PDU ::= [0] IMPLICIT PDU
#
# PDU ::= SEQUENCE {
# request-id INTEGER (-214783648..214783647),
#
# error-status -- sometimes ignored
# INTEGER {
# noError(0),
# tooBig(1),
# noSuchName(2), -- for proxy compatibility
# badValue(3), -- for proxy compatibility
# readOnly(4), -- for proxy compatibility
# genErr(5),
# noAccess(6),
# wrongType(7),
# wrongLength(8),
# wrongEncoding(9),
# wrongValue(10),
# noCreation(11),
# inconsistentValue(12),
# resourceUnavailable(13),
# commitFailed(14),
# undoFailed(15),
# authorizationError(16),
# notWritable(17),
# inconsistentName(18)
# },
#
# error-index -- sometimes ignored
# INTEGER (0..max-bindings),
#
# variable-bindings -- values are sometimes ignored
# VarBindList
# }
# @author Sylvain Daubert
class GetRequest < RASN1::Model
sequence :pdu,
implicit: SNMP::PDU_GET, constructed: true,
content: [integer(:id, value: 0),
enumerated(:error, enum: ERRORS),
integer(:error_index),
model(:varbindlist, VariableBindings)]
# @return [String]
def inspect
Inspect.inspect_body(to_der, self.class)
end
end
# Class to handle GetNextRequest PDU
# GetNextRequest-PDU ::= [1] IMPLICIT PDU -- PDU definition: see GetRequest
# @author Sylvain Daubert
class GetNextRequest < GetRequest
root_options implicit: SNMP::PDU_NEXT
end
# Class to handle GetResponse PDU
# GetResponse-PDU ::= [2] IMPLICIT PDU -- PDU definition: see GetRequest
# @author Sylvain Daubert
class GetResponse < GetRequest
root_options implicit: SNMP::PDU_RESPONSE
end
# Class to handle SetRequest PDU
# SetRequest-PDU ::= [3] IMPLICIT PDU -- PDU definition: see GetRequest
# @author Sylvain Daubert
class SetRequest < GetRequest
root_options implicit: SNMP::PDU_GET
end
# Class to handle Trap from SNMPv1
# Trap-PDU ::= [4] IMPLICIT SEQUENCE {
# enterprise OBJECT IDENTIFIER,
# agent-addr NetworkAddress,
# generic-trap -- generic trap type
# INTEGER {
# coldStart(0),
# warmStart(1),
# linkDown(2),
# linkUp(3),
# authenticationFailure(4),
# egpNeighborLoss(5),
# enterpriseSpecific(6)
# },
# specific-trap INTEGER,
# time-stamp TimeTicks,
# variable-bindings VarBindList
# }
class Trapv1 < RASN1::Model
sequence :trap,
implicit: SNMP::PDU_TRAPv1, constructed: true,
content: [objectid(:enterprise),
octet_string(:agent_addr),
enumerated(:generic_trap, enum: { 'cold_start' => 0,
'warm_start' => 1,
'link_down' => 2,
'link_up' => 3,
'auth_failure' => 4,
'egp_neighbor_loss' => 5,
'specific' => 6 }),
integer(:specific_trap),
integer(:timestamp),
model(:varbindlist, VariableBindings)]
end
# Class to handle Bulk PDU
# GetBulkRequest-PDU ::= [5] IMPLICIT BulkPDU
#
# BulkPDU ::= -- must be identical in
# SEQUENCE { -- structure to PDU
# request-id INTEGER (-214783648..214783647),
# non-repeaters INTEGER (0..max-bindings),
# max-repetitions INTEGER (0..max-bindings),
# variable-bindings -- values are ignored
# VarBindList
# }
# @author Sylvain Daubert
class Bulk < RASN1::Model
sequence :bulkpdu,
implicit: SNMP::PDU_BULK, constructed: true,
content: [integer(:id, value: 0),
integer(:non_repeaters),
integer(:max_repetitions),
model(:varbindlist, VariableBindings)]
# @return [String]
def inspect
Inspect.inspect_body(to_der, self.class)
end
end
# Class to handle InformRequest PDU
# InformRequest-PDU ::= [6] IMPLICIT PDU -- PDU definition: see GetRequest
# @author Sylvain Daubert
class InformRequest < GetRequest
root_options implicit: SNMP::PDU_INFORM
end
# Class to handle Trapv2 PDU
# SNMPv2-Trap-PDU ::= [7] IMPLICIT PDU -- PDU definition: see GetRequest
# @author Sylvain Daubert
class Trapv2 < GetRequest
root_options implicit: SNMP::PDU_TRAPv2
end
# Class to handle Report PDU
# Report-PDU ::= [8] IMPLICIT PDU -- PDU definition: see GetRequest
# @author Sylvain Daubert
class Report < GetRequest
root_options implicit: SNMP::PDU_REPORT
end
# Class to handle PDUs from SNMP packet
# PDUs ::= CHOICE {
# get-request [0] IMPLICIT PDU,
# get-next-request [1] IMPLICIT PDU,
# get-response [2] IMPLICIT PDU,
# set-request [3] IMPLICIT PDU,
# snmpV1-trap [4] IMPLICIT PDU,
# get-bulk-request [5] IMPLICIT PDU,
# inform-request [6] IMPLICIT PDU,
# snmpV2-trap [7] IMPLICIT PDU,
# report [8] IMPLICIT PDU
# }
# @author Sylvain Daubert
class PDUs < RASN1::Model
choice :pdus,
content: [model(:get_request, GetRequest),
model(:get_next_request, GetNextRequest),
model(:get_response, GetResponse),
model(:set_request, SetRequest),
#model(:trapv1, Trapv1),
model(:bulk, Bulk),
model(:inform, InformRequest),
model(:trapv2, Trapv2),
model(:report, Report)]
end
sequence :message,
content: [enumerated(:version, value: 'v2c',
enum: { 'v1' => 0, 'v2c' => 1, 'v2' => 2, 'v3' => 3 }),
octet_string(:community, value: 'public'),
model(:data, PDUs)]
define_attributes :version, :community
# accessor to data payload
# @return [GetRequest]
def data
@elements[:data]
end
def inspect
str = super
str << Inspect.shift_level(2)
if self[:data].chosen.nil?
str << Inspect::FMT_ATTR % [self[:data].type, :data, '']
else
data = self[:data]
str << Inspect::FMT_ATTR % [data.type, :data, data.chosen_value.type]
str << data.chosen_value.inspect
end
end
end
self.add_class SNMP
UDP.bind_header SNMP, dport: SNMP::UDP_PORT1, sport: SNMP::UDP_PORT1
UDP.bind_header SNMP, dport: SNMP::UDP_PORT2, sport: SNMP::UDP_PORT2
end
end