forked from packethost/goflow
-
Notifications
You must be signed in to change notification settings - Fork 0
/
sflow.go
321 lines (292 loc) · 9.48 KB
/
sflow.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
package sflow
import (
"bytes"
"fmt"
"github.com/cloudflare/goflow/decoders/utils"
)
const (
FORMAT_EXT_SWITCH = 1001
FORMAT_EXT_ROUTER = 1002
FORMAT_EXT_GATEWAY = 1003
FORMAT_RAW_PKT = 1
FORMAT_ETH = 2
FORMAT_IPV4 = 3
FORMAT_IPV6 = 4
)
type ErrorDecodingSFlow struct {
msg string
}
func NewErrorDecodingSFlow(msg string) *ErrorDecodingSFlow {
return &ErrorDecodingSFlow{
msg: msg,
}
}
func (e *ErrorDecodingSFlow) Error() string {
return fmt.Sprintf("Error decoding sFlow: %v", e.msg)
}
type ErrorDataFormat struct {
dataformat uint32
}
func NewErrorDataFormat(dataformat uint32) *ErrorDataFormat {
return &ErrorDataFormat{
dataformat: dataformat,
}
}
func (e *ErrorDataFormat) Error() string {
return fmt.Sprintf("Unknown data format %v", e.dataformat)
}
type ErrorIPVersion struct {
version uint32
}
func NewErrorIPVersion(version uint32) *ErrorIPVersion {
return &ErrorIPVersion{
version: version,
}
}
func (e *ErrorIPVersion) Error() string {
return fmt.Sprintf("Unknown IP version: %v", e.version)
}
type ErrorVersion struct {
version uint32
}
func NewErrorVersion(version uint32) *ErrorVersion {
return &ErrorVersion{
version: version,
}
}
func (e *ErrorVersion) Error() string {
return fmt.Sprintf("Unknown sFlow version %v (supported v5)", e.version)
}
func DecodeCounterRecord(header *RecordHeader, payload *bytes.Buffer) (CounterRecord, error) {
counterRecord := CounterRecord{
Header: *header,
}
switch (*header).DataFormat {
case 1:
ifCounters := IfCounters{}
utils.BinaryDecoder(payload, &ifCounters)
counterRecord.Data = ifCounters
case 2:
ethernetCounters := EthernetCounters{}
utils.BinaryDecoder(payload, ðernetCounters)
counterRecord.Data = ethernetCounters
default:
return counterRecord, NewErrorDataFormat((*header).DataFormat)
}
return counterRecord, nil
}
func DecodeIP(payload *bytes.Buffer) (uint32, []byte, error) {
var ipVersion uint32
utils.BinaryDecoder(payload, &ipVersion)
var ip []byte
if ipVersion == 1 {
ip = make([]byte, 4)
} else if ipVersion == 2 {
ip = make([]byte, 16)
} else {
return ipVersion, ip, NewErrorIPVersion(ipVersion)
}
if payload.Len() >= len(ip) {
utils.BinaryDecoder(payload, &ip)
} else {
return ipVersion, ip, NewErrorDecodingSFlow(fmt.Sprintf("Not enough data: %v, needs %v.", payload.Len(), len(ip)))
}
return ipVersion, ip, nil
}
func DecodeFlowRecord(header *RecordHeader, payload *bytes.Buffer) (FlowRecord, error) {
flowRecord := FlowRecord{
Header: *header,
}
switch (*header).DataFormat {
case FORMAT_EXT_SWITCH:
extendedSwitch := ExtendedSwitch{}
utils.BinaryDecoder(payload, &extendedSwitch)
flowRecord.Data = extendedSwitch
case FORMAT_RAW_PKT:
sampledHeader := SampledHeader{}
utils.BinaryDecoder(payload, &(sampledHeader.Protocol), &(sampledHeader.FrameLength), &(sampledHeader.Stripped), &(sampledHeader.OriginalLength))
sampledHeader.HeaderData = payload.Bytes()
flowRecord.Data = sampledHeader
case FORMAT_IPV4:
sampledIPBase := SampledIP_Base{
SrcIP: make([]byte, 4),
DstIP: make([]byte, 4),
}
utils.BinaryDecoder(payload, &sampledIPBase)
sampledIPv4 := SampledIPv4{
Base: sampledIPBase,
}
utils.BinaryDecoder(payload, &(sampledIPv4.Tos))
flowRecord.Data = sampledIPv4
case FORMAT_IPV6:
sampledIPBase := SampledIP_Base{
SrcIP: make([]byte, 16),
DstIP: make([]byte, 16),
}
utils.BinaryDecoder(payload, &sampledIPBase)
sampledIPv6 := SampledIPv6{
Base: sampledIPBase,
}
utils.BinaryDecoder(payload, &(sampledIPv6.Priority))
flowRecord.Data = sampledIPv6
case FORMAT_EXT_ROUTER:
extendedRouter := ExtendedRouter{}
ipVersion, ip, err := DecodeIP(payload)
if err != nil {
return flowRecord, err
}
extendedRouter.NextHopIPVersion = ipVersion
extendedRouter.NextHop = ip
utils.BinaryDecoder(payload, &(extendedRouter.SrcMaskLen), &(extendedRouter.DstMaskLen))
flowRecord.Data = extendedRouter
case FORMAT_EXT_GATEWAY:
extendedGateway := ExtendedGateway{}
ipVersion, ip, err := DecodeIP(payload)
if err != nil {
return flowRecord, err
}
extendedGateway.NextHopIPVersion = ipVersion
extendedGateway.NextHop = ip
utils.BinaryDecoder(payload, &(extendedGateway.AS), &(extendedGateway.SrcAS), &(extendedGateway.SrcPeerAS),
&(extendedGateway.ASDestinations))
asPath := make([]uint32, 0)
if extendedGateway.ASDestinations != 0 {
utils.BinaryDecoder(payload, &(extendedGateway.ASPathType), &(extendedGateway.ASPathLength))
if int(extendedGateway.ASPathLength) > payload.Len()-4 {
return flowRecord, NewErrorDecodingSFlow(fmt.Sprintf("Invalid AS path length.", extendedGateway.ASPathLength))
}
asPath = make([]uint32, extendedGateway.ASPathLength)
if len(asPath) > 0 {
utils.BinaryDecoder(payload, asPath)
}
}
extendedGateway.ASPath = asPath
utils.BinaryDecoder(payload, &(extendedGateway.CommunitiesLength))
if int(extendedGateway.CommunitiesLength) > payload.Len()-4 {
return flowRecord, NewErrorDecodingSFlow(fmt.Sprintf("Invalid Communities length.", extendedGateway.ASPathLength))
}
communities := make([]uint32, extendedGateway.CommunitiesLength)
if len(communities) > 0 {
utils.BinaryDecoder(payload, communities)
}
utils.BinaryDecoder(payload, &(extendedGateway.LocalPref))
extendedGateway.Communities = communities
flowRecord.Data = extendedGateway
default:
return flowRecord, NewErrorDecodingSFlow(fmt.Sprintf("Unknown data format %v.", (*header).DataFormat))
}
return flowRecord, nil
}
func DecodeSample(header *SampleHeader, payload *bytes.Buffer) (interface{}, error) {
format := (*header).Format
var sample interface{}
utils.BinaryDecoder(payload, &((*header).SampleSequenceNumber))
if format == FORMAT_RAW_PKT || format == FORMAT_ETH {
var sourceId uint32
utils.BinaryDecoder(payload, &sourceId)
(*header).SourceIdType = sourceId >> 24
(*header).SourceIdValue = sourceId & 0x00ffffff
} else if format == FORMAT_IPV4 || format == FORMAT_IPV6 {
utils.BinaryDecoder(payload, &((*header).SourceIdType), &((*header).SourceIdValue))
} else {
return nil, NewErrorDataFormat(format)
}
var recordsCount uint32
var flowSample FlowSample
var counterSample CounterSample
var expandedFlowSample ExpandedFlowSample
if format == FORMAT_RAW_PKT {
flowSample = FlowSample{
Header: *header,
}
utils.BinaryDecoder(payload, &(flowSample.SamplingRate), &(flowSample.SamplePool),
&(flowSample.Drops), &(flowSample.Input), &(flowSample.Output), &(flowSample.FlowRecordsCount))
recordsCount = flowSample.FlowRecordsCount
flowSample.Records = make([]FlowRecord, recordsCount)
sample = flowSample
} else if format == FORMAT_ETH || format == FORMAT_IPV6 {
utils.BinaryDecoder(payload, &recordsCount)
counterSample = CounterSample{
Header: *header,
CounterRecordsCount: recordsCount,
}
counterSample.Records = make([]CounterRecord, recordsCount)
sample = counterSample
} else if format == FORMAT_IPV4 {
expandedFlowSample = ExpandedFlowSample{
Header: *header,
}
utils.BinaryDecoder(payload, &(expandedFlowSample.SamplingRate), &(expandedFlowSample.SamplePool),
&(expandedFlowSample.Drops), &(expandedFlowSample.InputIfFormat), &(expandedFlowSample.InputIfValue),
&(expandedFlowSample.OutputIfFormat), &(expandedFlowSample.OutputIfValue), &(expandedFlowSample.FlowRecordsCount))
recordsCount = expandedFlowSample.FlowRecordsCount
expandedFlowSample.Records = make([]FlowRecord, recordsCount)
sample = expandedFlowSample
}
for i := 0; i < int(recordsCount) && payload.Len() >= 8; i++ {
recordHeader := RecordHeader{}
utils.BinaryDecoder(payload, &(recordHeader.DataFormat), &(recordHeader.Length))
if int(recordHeader.Length) > payload.Len() {
break
}
recordReader := bytes.NewBuffer(payload.Next(int(recordHeader.Length)))
if format == FORMAT_RAW_PKT || format == FORMAT_IPV4 {
record, err := DecodeFlowRecord(&recordHeader, recordReader)
if err != nil {
continue
}
if format == FORMAT_RAW_PKT {
flowSample.Records[i] = record
} else if format == FORMAT_IPV4 {
expandedFlowSample.Records[i] = record
}
} else if format == FORMAT_ETH || format == FORMAT_IPV6 {
record, err := DecodeCounterRecord(&recordHeader, recordReader)
if err != nil {
continue
}
counterSample.Records[i] = record
}
}
return sample, nil
}
func DecodeMessage(payload *bytes.Buffer) (interface{}, error) {
var version uint32
utils.BinaryDecoder(payload, &version)
packetV5 := Packet{}
if version == 5 {
packetV5.Version = version
utils.BinaryDecoder(payload, &(packetV5.IPVersion))
var ip []byte
if packetV5.IPVersion == 1 {
ip = make([]byte, 4)
utils.BinaryDecoder(payload, ip)
} else if packetV5.IPVersion == 2 {
ip = make([]byte, 16)
utils.BinaryDecoder(payload, ip)
} else {
return nil, NewErrorIPVersion(packetV5.IPVersion)
}
packetV5.AgentIP = ip
utils.BinaryDecoder(payload, &(packetV5.SubAgentId), &(packetV5.SequenceNumber), &(packetV5.Uptime), &(packetV5.SamplesCount))
packetV5.Samples = make([]interface{}, int(packetV5.SamplesCount))
for i := 0; i < int(packetV5.SamplesCount) && payload.Len() >= 8; i++ {
header := SampleHeader{}
utils.BinaryDecoder(payload, &(header.Format), &(header.Length))
if int(header.Length) > payload.Len() {
break
}
sampleReader := bytes.NewBuffer(payload.Next(int(header.Length)))
sample, err := DecodeSample(&header, sampleReader)
if err != nil {
continue
} else {
packetV5.Samples[i] = sample
}
}
return packetV5, nil
} else {
return nil, NewErrorVersion(version)
}
return nil, nil
}