108 lines
2.6 KiB
Ruby
108 lines
2.6 KiB
Ruby
# $Id$
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#
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# NET::SNMP
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#
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#----------------------------------------------------------------------------
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#
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# Copyright (C) 2006 by Francis Cianfrocca. All Rights Reserved.
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#
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# Gmail: garbagecat10
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#
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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#
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#---------------------------------------------------------------------------
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#
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#
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require 'net/ber'
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module Net
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class SNMP
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AsnSyntax = BER.compile_syntax({
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:application => {
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:primitive => {
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},
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:constructed => {
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}
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},
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:context_specific => {
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:primitive => {
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},
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:constructed => {
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0 => :array # GetRequest PDU (RFC1157 pgh 4.1.2)
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}
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}
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})
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end
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class SnmpPdu
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class Error < Exception; end
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attr_reader :version, :community, :pdu_type, :request_id, :variables
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#--
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# TODO, improve the error-trapping.
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# We want to wrap up Ruby errors like array-ranges, which can appear if we get bad data.
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# We should probably do the whole parse under a catch-all block.
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def initialize ber_object
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begin
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parse_ber_object ber_object
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rescue RuntimeError
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# Wrap any basic parsing error so it becomes a PDU-format error
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raise Error.new( "snmp-pdu format error" )
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end
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end
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def parse_ber_object ber_object
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@version = ber_object[0].to_i
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unless [0,2].include?(@version)
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raise Error.new("unknown snmp-version: #{@version}")
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end
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@community = ber_object[1].to_s
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data = ber_object[2]
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app_tag = data.ber_identifier & 31
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case app_tag
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when 0
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@pdu_type = :get_request
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parse_get_request data
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else
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raise Error.new( "unknown snmp-pdu type: #{app_tag}" )
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end
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end
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#--
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# Defined in RFC1157, pgh 4.1.2.
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def parse_get_request data
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@request_id = data[0].to_i
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# data[1] is error-status, always 0.
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# data[2] is error-index, always 0.
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@variables = data[3].map {|v|
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# A variable-binding, of which there may be several,
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# consists of an OID and a BER null.
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# We're ignoring the null, we might want to verify it instead.
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v[0]
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}
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end
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end
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end
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