Real-time collaboration for Jupyter Notebooks, Linux Terminals, LaTeX, VS Code, R IDE, and more,
all in one place.

1
#
2
# Copyright (c) 2004 David R. Halliday
3
# All rights reserved.
4
#
5
# This SNMP library is free software.  Redistribution is permitted under the
6
# same terms and conditions as the standard Ruby distribution.  See the
7
# COPYING file in the Ruby distribution for details.
8
#
9

10
require 'snmp/ber'
11

12
include SNMP::BER
13

14
module SNMP
15

16
class UnsupportedValueTag < RuntimeError; end
17
class InvalidIpAddress < ArgumentError; end
18

19
class VarBindList < Array
20
    def self.decode(data)
21
        list = VarBindList.new
22
        varbind_data, remainder = decode_sequence(data)
23
        while varbind_data != ""
24
            varbind, varbind_data = VarBind.decode(varbind_data)
25
            list << varbind
26
        end
27
        return list, remainder    
28
    end
29

30
    def initialize(varbind_list=[])
31
        super()
32
        if varbind_list.respond_to? :to_str
33
            self << ObjectId.new(varbind_list.to_str).to_varbind
34
        elsif varbind_list.respond_to? :to_varbind
35
            self << varbind_list.to_varbind
36
        else
37
            varbind_list.each do |item|
38
                if item.respond_to? :to_str
39
                    self << ObjectId.new(item.to_str).to_varbind
40
                else
41
                    self << item.to_varbind
42
                end
43
            end
44
        end
45
    end
46
    
47
    def asn1_type
48
        "VarBindList"
49
    end
50
    
51
    def encode
52
        varbind_data = ""
53
        self.each do |varbind|
54
            varbind_data << varbind.encode
55
        end
56
        encode_sequence(varbind_data)
57
    end
58
end
59

60
class Integer
61
    include Comparable
62
    
63
    def self.decode(value_data)
64
        Integer.new(decode_integer_value(value_data))
65
    end
66
    
67
    def asn1_type
68
        "INTEGER"
69
    end
70

71
    def initialize(value)
72
        @value = value.to_i
73
    end
74

75
    def <=>(other)
76
        @value <=> other.to_i
77
    end
78
    
79
    def coerce(other)
80
        if other.kind_of? Integer
81
            return [other, @value]
82
        else
83
            return [other.to_f, self.to_f]
84
        end
85
    end
86
    
87
    def to_s
88
        @value.to_s
89
    end
90

91
    def to_i
92
        @value
93
    end
94
    
95
    def to_f
96
        @value.to_f
97
    end
98
    
99
    def encode
100
        encode_integer(@value)
101
    end
102
    
103
    def to_oid
104
        raise RangeError, "@{value} cannot be an OID (must be >0)" if @value < 0
105
        ObjectId.new([@value])
106
    end
107
end
108

109
class Integer32 < Integer
110
    def initialize(value)
111
        super(value)
112
        raise ArgumentError, "Out of range: #{value}" if value < -2147483648
113
        raise ArgumentError, "Out of range: #{value}" if value > 2147483647
114
    end
115
end
116

117
class OctetString < String
118
    def self.decode(value_data)
119
        OctetString.new(value_data)
120
    end
121

122
    def asn1_type
123
        "OCTET STRING"
124
    end
125
    
126
    def encode
127
        encode_octet_string(self)
128
    end
129
    
130
    def to_oid
131
        oid = ObjectId.new
132
        each_byte { |b| oid << b }
133
        oid
134
    end
135
end
136

137
class ObjectId < Array
138
    include Comparable
139
    
140
    def self.decode(value_data)
141
        ObjectId.new(decode_object_id_value(value_data))
142
    end
143

144
    def asn1_type
145
        "OBJECT IDENTIFIER"
146
    end
147
    
148
    ##
149
    # Create an object id.  The input is expected to be either a string
150
    # in the format "n.n.n.n.n.n" or an array of integers.
151
    #
152
    def initialize(id=[])
153
        if id.nil?
154
            raise ArgumentError
155
        elsif id.respond_to? :to_str
156
            super(make_integers(id.to_str.split(".")))
157
        else
158
            super(make_integers(id.to_ary))
159
        end
160
    rescue ArgumentError
161
        raise ArgumentError, "#{id.inspect}:#{id.class} not a valid object ID"
162
    end
163
    
164
    def to_varbind
165
        VarBind.new(self, Null)
166
    end
167
    
168
    def to_oid
169
        self
170
    end
171
    
172
    def to_s
173
        self.join('.')
174
    end
175
    
176
    def inspect
177
        "[#{self.to_s}]"
178
    end
179
    
180
    def encode
181
        encode_object_id(self)
182
    end
183
    
184
    ##
185
    # Returns true if this ObjectId is a subtree of the provided parent tree
186
    # ObjectId.  For example, "1.3.6.1.5" is a subtree of "1.3.6.1".
187
    #
188
    def subtree_of?(parent_tree)
189
        parent_tree = make_object_id(parent_tree)
190
        if parent_tree.length > self.length
191
            false
192
        else
193
            parent_tree.each_index do |i|
194
                return false if parent_tree[i] != self[i]
195
            end
196
            true
197
        end
198
    end
199
    
200
    ##
201
    # Returns an index based on the difference between this ObjectId
202
    # and the provided parent ObjectId.
203
    #
204
    # For example, ObjectId.new("1.3.6.1.5").index("1.3.6.1") returns an
205
    # ObjectId of "5".
206
    #
207
    def index(parent_tree)
208
        parent_tree = make_object_id(parent_tree)
209
        if not subtree_of?(parent_tree)
210
            raise ArgumentError, "#{self.to_s} not a subtree of #{parent_tree.to_s}"
211
        elsif self.length == parent_tree.length
212
            raise ArgumentError, "OIDs are the same"
213
        else
214
            ObjectId.new(self[parent_tree.length..-1])
215
        end
216
    end
217
    
218
    private
219
    
220
    def make_integers(list)
221
        list.collect{|n| Integer(n)}
222
    end 
223
    
224
    def make_object_id(oid)
225
        oid.kind_of?(ObjectId) ? oid : ObjectId.new(oid)
226
    end
227
    
228
end
229

230
class IpAddress
231
    class << self
232
        def decode(value_data)
233
            IpAddress.new(value_data)
234
        end
235
    end
236

237
    def asn1_type
238
        "IpAddress"
239
    end
240

241
    ##
242
    # Create an IpAddress object.  The constructor accepts either a raw
243
    # four-octet string or a formatted string of integers separated by dots
244
    # (i.e. "10.1.2.3").
245
    #
246
    def initialize(value_data)
247
        ip = value_data.to_str
248
        if ip.length > 4
249
            ip = parse_string(ip)
250
        elsif ip.length != 4
251
            raise InvalidIpAddress, "Expected 4 octets or formatted string, got #{value_data.inspect}"
252
        end
253
        @value = ip
254
    end
255
    
256
    ##
257
    # Returns a raw four-octet string representing this IpAddress.
258
    #
259
    def to_str
260
        @value.dup
261
    end
262
    
263
    ##
264
    # Returns a formatted, dot-separated string representing this IpAddress.
265
    #
266
    def to_s
267
        octets = []
268
        @value.each_byte { |b| octets << b.to_s }
269
        octets.join('.')    
270
    end
271
    
272
    def to_oid
273
        oid = ObjectId.new
274
        @value.each_byte { |b| oid << b }
275
        oid
276
    end
277
    
278
    def ==(other)
279
        if other.respond_to? :to_str
280
            return @value.eql?(other.to_str)
281
        else
282
            return false
283
        end
284
    end
285
    
286
    def eql?(other)
287
        self == other
288
    end
289
    
290
    def hash
291
        @value.hash
292
    end
293
    
294
    def encode
295
        encode_tlv(IpAddress_TAG, @value)
296
    end
297

298
    private
299
    def parse_string(ip_string)
300
        parts = ip_string.split(".")
301
        raise InvalidIpAddress, ip_string.inspect if parts.length != 4
302
        value_data = ""
303
        parts.each do |s| 
304
            octet = s.to_i
305
            raise InvalidIpAddress, ip_string.inspect if octet > 255
306
            raise InvalidIpAddress, ip_string.inspect if octet < 0
307
            value_data << octet.chr
308
        end
309
        value_data
310
    end
311

312
end
313

314
class UnsignedInteger < Integer
315
    def initialize(value)
316
        super(value)
317
        raise ArgumentError, "Negative integer invalid: #{value}" if value < 0
318
        raise ArgumentError, "Out of range: #{value}" if value > 4294967295
319
    end
320
    
321
    def self.decode(value_data)
322
        self.new(decode_uinteger_value(value_data))
323
    end
324
end
325

326
class Counter32 < UnsignedInteger
327
    def asn1_type
328
        "Counter32"
329
    end
330

331
    def encode
332
        encode_tagged_integer(Counter32_TAG, @value)
333
    end
334
end
335

336
class Gauge32 < UnsignedInteger
337
    def asn1_type
338
        "Gauge32"
339
    end
340

341
    def encode
342
        encode_tagged_integer(Gauge32_TAG, @value)
343
    end
344
end
345

346
class Unsigned32 < UnsignedInteger
347
    def asn1_type
348
        "Unsigned32"
349
    end
350

351
    def encode
352
        encode_tagged_integer(Unsigned32_TAG, @value)
353
    end
354
end
355

356
class TimeTicks < UnsignedInteger
357
    def asn1_type
358
        "TimeTicks"
359
    end
360

361
    def encode
362
        encode_tagged_integer(TimeTicks_TAG, @value)
363
    end
364
    
365
    def to_s
366
        days, remainder = @value.divmod(8640000)
367
        hours, remainder = remainder.divmod(360000)
368
        minutes, remainder = remainder.divmod(6000)
369
        seconds, hundredths = remainder.divmod(100)
370
        case
371
            when days < 1
372
                sprintf('%02d:%02d:%02d.%02d',
373
                        hours, minutes, seconds, hundredths)
374
            when days == 1
375
                sprintf('1 day, %02d:%02d:%02d.%02d',
376
                        hours, minutes, seconds, hundredths)
377
            when days > 1
378
                sprintf('%d days, %02d:%02d:%02d.%02d',
379
                        days, hours, minutes, seconds, hundredths)
380
        end
381
    end
382
end
383

384
class Opaque < OctetString
385
    def self.decode(value_data)
386
        Opaque.new(value_data)
387
    end
388
    
389
    def asn1_type
390
        "Opaque"
391
    end
392
    
393
    def encode
394
        encode_tlv(Opaque_TAG, self)
395
    end
396
end
397

398
class Counter64 < Integer
399
    def self.decode(value_data)
400
        Counter64.new(decode_integer_value(value_data))
401
    end
402

403
    def asn1_type
404
        "Counter64"
405
    end
406

407
    def initialize(value)
408
        super(value)
409
        raise ArgumentError, "Negative integer invalid: #{value}" if value < 0
410
        raise ArgumentError, "Out of range: #{value}" if value > 18446744073709551615
411
    end    
412
    
413
    def encode
414
        encode_tagged_integer(Counter64_TAG, @value)
415
    end
416
end
417

418
class Null
419
    class << self
420
        def decode(value_data)
421
            Null
422
        end
423

424
        def encode
425
            encode_null
426
        end
427
        
428
        def asn1_type
429
            'Null'
430
        end
431

432
        def to_s
433
            asn1_type
434
        end
435
    end
436
end
437

438
class NoSuchObject
439
    class << self
440
        def decode(value_data)
441
            NoSuchObject
442
        end
443

444
        def encode
445
            encode_exception(NoSuchObject_TAG)
446
        end
447

448
        def asn1_type
449
            'noSuchObject'
450
        end
451
        
452
        def to_s
453
            asn1_type
454
        end
455
    end
456
end
457

458
class NoSuchInstance
459
    class << self
460
        def decode(value_data)
461
            NoSuchInstance
462
        end
463

464
        def encode
465
            encode_exception(NoSuchInstance_TAG)
466
        end
467
        
468
        def asn1_type
469
            'noSuchInstance'
470
        end
471
        
472
        def to_s
473
            asn1_type
474
        end
475
    end
476
end
477

478
class EndOfMibView
479
    class << self
480
        def decode(value_data)
481
            EndOfMibView
482
        end
483

484
        def encode
485
            encode_exception(EndOfMibView_TAG)
486
        end
487
        
488
        def asn1_type
489
            'endOfMibView'
490
        end
491
        
492
        def to_s
493
            asn1_type
494
        end
495
    end
496
end
497

498
class VarBind
499
    attr_accessor :name
500
    attr_accessor :value
501
    
502
    alias :oid :name
503
    
504
    class << self
505
        def decode(data)
506
            varbind_data, remaining_varbind_data = decode_sequence(data)
507
            name, remainder = decode_object_id(varbind_data)
508
            value, remainder = decode_value(remainder)
509
            assert_no_remainder(remainder)
510
            return VarBind.new(name, value), remaining_varbind_data
511
        end
512

513
        ValueDecoderMap = {
514
            INTEGER_TAG           => Integer,
515
            OCTET_STRING_TAG      => OctetString,
516
            NULL_TAG              => Null,
517
            OBJECT_IDENTIFIER_TAG => ObjectId,
518
            IpAddress_TAG         => IpAddress,
519
            Counter32_TAG         => Counter32,
520
            Gauge32_TAG           => Gauge32,
521
            # note Gauge32 tag same as Unsigned32
522
            TimeTicks_TAG         => TimeTicks,
523
            Opaque_TAG            => Opaque,
524
            Counter64_TAG         => Counter64,
525
            NoSuchObject_TAG      => NoSuchObject,
526
            NoSuchInstance_TAG    => NoSuchInstance,
527
            EndOfMibView_TAG      => EndOfMibView
528
        }
529
        
530
        def decode_value(data)
531
            value_tag, value_data, remainder = decode_tlv(data)
532
            decoder_class = ValueDecoderMap[value_tag]
533
            if decoder_class
534
                value = decoder_class.decode(value_data)
535
            else
536
               raise UnsupportedValueTag, value_tag.to_s
537
            end
538
            return value, remainder
539
        end
540
    end
541
    
542
    def initialize(name, value=Null)
543
        if name.kind_of? ObjectId
544
            @name = name
545
        else
546
            @name = ObjectName.new(name)
547
        end
548
        @value = value
549
    end
550

551
    def asn1_type
552
        "VarBind"
553
    end
554
    
555
    def to_varbind
556
        self
557
    end
558
    
559
    def to_s
560
        "[name=#{@name.to_s}, value=#{@value.to_s} (#{@value.asn1_type})]"
561
    end
562
    
563
    def each
564
        yield self
565
    end
566
    
567
    def encode
568
        data = encode_object_id(@name) << value.encode
569
        encode_sequence(data)
570
    end
571
end
572

573
class ObjectName < ObjectId
574
    def asn1_type
575
        "ObjectName"
576
    end
577
end
578

579
end
580

581