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
|
package main
import (
"context"
"encoding/binary"
"fmt"
"github.com/flier/gohs/hyperscan"
"github.com/google/gopacket"
"github.com/google/gopacket/tcpassembly"
"log"
"sync"
"time"
)
type BiDirectionalStreamFactory struct {
storage Storage
serverIp gopacket.Endpoint
connections map[StreamKey]ConnectionHandler
mConnections sync.Mutex
patterns hyperscan.StreamDatabase
mPatterns sync.Mutex
scratches []*hyperscan.Scratch
}
type StreamKey [4]gopacket.Endpoint
type ConnectionHandler interface {
Complete(handler *StreamHandler)
Storage() Storage
Context() context.Context
Patterns() hyperscan.StreamDatabase
}
type connectionHandlerImpl struct {
storage Storage
net, transport gopacket.Flow
initiator StreamKey
connectionKey string
mComplete sync.Mutex
otherStream *StreamHandler
context context.Context
patterns hyperscan.StreamDatabase
}
func (factory *BiDirectionalStreamFactory) New(net, transport gopacket.Flow) tcpassembly.Stream {
key := StreamKey{net.Src(), net.Dst(), transport.Src(), transport.Dst()}
invertedKey := StreamKey{net.Dst(), net.Src(), transport.Dst(), transport.Src()}
factory.mConnections.Lock()
connection, isPresent := factory.connections[invertedKey]
if isPresent {
delete(factory.connections, invertedKey)
} else {
var initiator StreamKey
if net.Src() == factory.serverIp {
initiator = invertedKey
} else {
initiator = key
}
connection = &connectionHandlerImpl{
storage: factory.storage,
net: net,
transport: transport,
initiator: initiator,
mComplete: sync.Mutex{},
context: context.Background(),
patterns : factory.patterns,
}
factory.connections[key] = connection
}
factory.mConnections.Unlock()
streamHandler := NewStreamHandler(connection, key, factory.takeScratch())
return &streamHandler
}
func (factory *BiDirectionalStreamFactory) UpdatePatternsDatabase(database hyperscan.StreamDatabase) {
factory.mPatterns.Lock()
factory.patterns = database
for _, s := range factory.scratches {
err := s.Realloc(database)
if err != nil {
fmt.Println("failed to realloc an existing scratch")
}
}
factory.mPatterns.Unlock()
}
func (ch *connectionHandlerImpl) Complete(handler *StreamHandler) {
ch.mComplete.Lock()
if ch.otherStream == nil {
ch.otherStream = handler
ch.mComplete.Unlock()
return
}
ch.mComplete.Unlock()
var startedAt, closedAt time.Time
if handler.firstPacketSeen.Before(ch.otherStream.firstPacketSeen) {
startedAt = handler.firstPacketSeen
} else {
startedAt = ch.otherStream.firstPacketSeen
}
if handler.lastPacketSeen.After(ch.otherStream.lastPacketSeen) {
closedAt = handler.lastPacketSeen
} else {
closedAt = ch.otherStream.lastPacketSeen
}
var client, server *StreamHandler
if handler.streamKey == ch.initiator {
client = handler
server = ch.otherStream
} else {
client = ch.otherStream
server = handler
}
ch.generateConnectionKey(startedAt)
_, err := ch.storage.InsertOne(ch.context, "connections", OrderedDocument{
{"_id", ch.connectionKey},
{"ip_src", ch.initiator[0].String()},
{"ip_dst", ch.initiator[1].String()},
{"port_src", ch.initiator[2].String()},
{"port_dst", ch.initiator[3].String()},
{"started_at", startedAt},
{"closed_at", closedAt},
{"client_bytes", client.streamLength},
{"server_bytes", server.streamLength},
{"client_documents", len(client.documentsKeys)},
{"server_documents", len(server.documentsKeys)},
{"processed_at", time.Now()},
})
if err != nil {
log.Println("error inserting document on collection connections with _id = ", ch.connectionKey)
}
streamsIds := append(client.documentsKeys, server.documentsKeys...)
n, err := ch.storage.UpdateOne(ch.context, "connection_streams",
UnorderedDocument{"_id": UnorderedDocument{"$in": streamsIds}},
UnorderedDocument{"connection_id": ch.connectionKey},
false)
if err != nil {
log.Println("failed to update connection streams", err)
}
if n != len(streamsIds) {
log.Println("failed to update all connections streams")
}
}
func (ch *connectionHandlerImpl) Storage() Storage {
return ch.storage
}
func (ch *connectionHandlerImpl) Context() context.Context {
return ch.context
}
func (ch *connectionHandlerImpl) Patterns() hyperscan.StreamDatabase {
return ch.patterns
}
func (ch *connectionHandlerImpl) generateConnectionKey(firstPacketSeen time.Time) {
hash := make([]byte, 16)
binary.BigEndian.PutUint64(hash, uint64(firstPacketSeen.UnixNano()))
binary.BigEndian.PutUint64(hash[8:], ch.net.FastHash()^ch.transport.FastHash())
ch.connectionKey = fmt.Sprintf("%x", hash)
}
func (factory *BiDirectionalStreamFactory) takeScratch() *hyperscan.Scratch {
factory.mPatterns.Lock()
defer factory.mPatterns.Unlock()
if len(factory.scratches) == 0 {
scratch, err := hyperscan.NewScratch(factory.patterns)
if err != nil {
fmt.Println("failed to alloc a new scratch")
}
return scratch
}
index := len(factory.scratches) - 1
scratch := factory.scratches[index]
factory.scratches = factory.scratches[:index]
return scratch
}
func (factory *BiDirectionalStreamFactory) releaseScratch(scratch *hyperscan.Scratch) {
factory.mPatterns.Lock()
factory.scratches = append(factory.scratches, scratch)
factory.mPatterns.Unlock()
}
|
