aboutsummaryrefslogtreecommitdiff
path: root/pcap_importer.go
blob: 388ec2deeae13a33e3652aab75565bfbc1c264ab (plain) (blame)
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
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
/*
 * This file is part of caronte (https://github.com/eciavatta/caronte).
 * Copyright (c) 2020 Emiliano Ciavatta.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, version 3.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

package main

import (
	"context"
	"errors"
	"net"
	"os"
	"path"
	"path/filepath"
	"sort"
	"sync"
	"time"

	"github.com/google/gopacket"
	"github.com/google/gopacket/layers"
	"github.com/google/gopacket/pcap"
	"github.com/google/gopacket/tcpassembly"
	log "github.com/sirupsen/logrus"
)

const PcapsBasePath = "pcaps/"
const ProcessingPcapsBasePath = PcapsBasePath + "processing/"
const initialAssemblerPoolSize = 16
const importUpdateProgressInterval = 100 * time.Millisecond
const MAX_PCAPS = 100

type PcapImporter struct {
	storage                Storage
	streamPool             *tcpassembly.StreamPool
	assemblers             []*tcpassembly.Assembler
	sessions               map[string]ImportingSession
	mAssemblers            sync.Mutex
	mSessions              sync.Mutex
	serverNet              net.IPNet
	notificationController *NotificationController
}

type ImportingSession struct {
	ID                string               `json:"id" bson:"_id"`
	StartedAt         time.Time            `json:"started_at" bson:"started_at"`
	Size              int64                `json:"size" bson:"size"`
	CompletedAt       time.Time            `json:"completed_at" bson:"completed_at,omitempty"`
	ProcessedPackets  int                  `json:"processed_packets" bson:"processed_packets"`
	InvalidPackets    int                  `json:"invalid_packets" bson:"invalid_packets"`
	PacketsPerService map[uint16]flowCount `json:"packets_per_service" bson:"packets_per_service"`
	ImportingError    string               `json:"importing_error" bson:"importing_error,omitempty"`
	cancelFunc        context.CancelFunc
	completed         chan string
}

type flowCount [2]int

func NewPcapImporter(storage Storage, serverNet net.IPNet, rulesManager RulesManager,
	notificationController *NotificationController) *PcapImporter {
	streamPool := tcpassembly.NewStreamPool(NewBiDirectionalStreamFactory(storage, serverNet, rulesManager))

	var result []ImportingSession
	if err := storage.Find(ImportingSessions).All(&result); err != nil {
		log.WithError(err).Panic("failed to retrieve importing sessions")
	}
	sessions := make(map[string]ImportingSession)
	for _, session := range result {
		sessions[session.ID] = session
	}

	return &PcapImporter{
		storage:                storage,
		streamPool:             streamPool,
		assemblers:             make([]*tcpassembly.Assembler, 0, initialAssemblerPoolSize),
		sessions:               sessions,
		mAssemblers:            sync.Mutex{},
		mSessions:              sync.Mutex{},
		serverNet:              serverNet,
		notificationController: notificationController,
	}
}

// Import a pcap file to the database. The pcap file must be present at the fileName path. If the pcap is already
// going to be imported or if it has been already imported in the past the function returns an error. Otherwise it
// create a new session and starts to import the pcap, and returns immediately the session name (that is the sha256
// of the pcap).
func (pi *PcapImporter) ImportPcap(fileName string, flushAll bool) (string, error) {
	switch filepath.Ext(fileName) {
	case ".pcap":
	case ".pcapng":
	default:
		deleteProcessingFile(fileName)
		return "", errors.New("invalid file extension")
	}

	hash, err := Sha256Sum(ProcessingPcapsBasePath + fileName)
	if err != nil {
		log.WithError(err).Panic("failed to calculate pcap sha256")
		deleteProcessingFile(fileName)
	}

	pi.mSessions.Lock()
	if _, isPresent := pi.sessions[hash]; isPresent {
		pi.mSessions.Unlock()
		deleteProcessingFile(fileName)
		return hash, errors.New("pcap already processed")
	}

	ctx, cancelFunc := context.WithCancel(context.Background())
	session := ImportingSession{
		ID:                hash,
		StartedAt:         time.Now(),
		Size:              FileSize(ProcessingPcapsBasePath + fileName),
		PacketsPerService: make(map[uint16]flowCount),
		cancelFunc:        cancelFunc,
		completed:         make(chan string),
	}

	pi.sessions[hash] = session
	pi.mSessions.Unlock()

	go pi.parsePcap(session, fileName, flushAll, ctx)

	return hash, nil
}

func (pi *PcapImporter) GetSessions() []ImportingSession {
	pi.mSessions.Lock()
	sessions := make([]ImportingSession, 0, len(pi.sessions))
	for _, session := range pi.sessions {
		sessions = append(sessions, session)
	}
	sort.Slice(sessions, func(i, j int) bool {
		return sessions[i].StartedAt.Before(sessions[j].StartedAt)
	})
	pi.mSessions.Unlock()
	return sessions
}

func (pi *PcapImporter) GetSession(sessionID string) (ImportingSession, bool) {
	pi.mSessions.Lock()
	defer pi.mSessions.Unlock()
	session, isPresent := pi.sessions[sessionID]
	return session, isPresent
}

func (pi *PcapImporter) CancelSession(sessionID string) bool {
	pi.mSessions.Lock()
	session, isPresent := pi.sessions[sessionID]
	if isPresent {
		session.cancelFunc()
	}
	pi.mSessions.Unlock()
	return isPresent
}

func (pi *PcapImporter) FlushConnections(olderThen time.Time, closeAll bool) (flushed, closed int) {
	assembler := pi.takeAssembler()
	flushed, closed = assembler.FlushWithOptions(tcpassembly.FlushOptions{
		T:        olderThen,
		CloseAll: closeAll,
	})
	pi.releaseAssembler(assembler)
	return
}

// Read the pcap and save the tcp stream flow to the database
func (pi *PcapImporter) parsePcap(session ImportingSession, fileName string, flushAll bool, ctx context.Context) {
	pcapHandle, err := pcap.OpenOffline(ProcessingPcapsBasePath + fileName)
	if err != nil {
		pi.progressUpdate(session, fileName, false, "failed to process pcap")
		log.WithError(err).WithFields(log.Fields{"session": session, "fileName": fileName}).
			Error("failed to open pcap")
		return
	}

	packetSource := gopacket.NewPacketSource(pcapHandle, pcapHandle.LinkType())
	packetSource.NoCopy = true
	assembler := pi.takeAssembler()
	packets := packetSource.Packets()
	updateProgressInterval := time.Tick(importUpdateProgressInterval)

	for {
		select {
		case <-ctx.Done():
			pcapHandle.Close()
			pi.releaseAssembler(assembler)
			pi.progressUpdate(session, fileName, false, "import process cancelled")
			return
		default:
		}

		select {
		case packet := <-packets:

			if packet == nil {
				// we read all the packets
				if flushAll {
					connectionsClosed := assembler.FlushAll()
					log.Debugf("connections closed after flush: %v", connectionsClosed)
				}
				pcapHandle.Close()
				pi.tryDeleteOldPcaps()
				pi.releaseAssembler(assembler)
				pi.progressUpdate(session, fileName, true, "")
				pi.notificationController.Notify("pcap.completed", session)

				return
			}

			session.ProcessedPackets++

			if packet.NetworkLayer() == nil {
				log.Warn("Invalid packet: no network layer")
				session.InvalidPackets++
				continue
			} else if packet.TransportLayer() == nil {
				log.Warn("Invalid packet: no transport layer")
				session.InvalidPackets++
				continue
			} else if packet.TransportLayer().LayerType() != layers.LayerTypeTCP {
				log.Warn("Invalid packet: no network or transport layer")
				session.InvalidPackets++
				continue
			}

			tcp := packet.TransportLayer().(*layers.TCP)
			var servicePort uint16
			var index int

			isDstServer := pi.serverNet.Contains(packet.NetworkLayer().NetworkFlow().Dst().Raw())
			isSrcServer := pi.serverNet.Contains(packet.NetworkLayer().NetworkFlow().Src().Raw())
			if isDstServer && !isSrcServer {
				servicePort = uint16(tcp.DstPort)
				index = 0
			} else if isSrcServer && !isDstServer {
				servicePort = uint16(tcp.SrcPort)
				index = 1
			} else {
				log.Warn("Invalid packet: source and destination are the same")
				session.InvalidPackets++
				continue
			}
			fCount, isPresent := session.PacketsPerService[servicePort]
			if !isPresent {
				fCount = flowCount{0, 0}
			}
			fCount[index]++
			session.PacketsPerService[servicePort] = fCount

			assembler.AssembleWithTimestamp(packet.NetworkLayer().NetworkFlow(), tcp, packet.Metadata().Timestamp)
		case <-updateProgressInterval:
			pi.progressUpdate(session, fileName, false, "")
		}
	}
}

func (pi *PcapImporter) tryDeleteOldPcaps() {
	sessions := pi.GetSessions()
	size := len(sessions)

	if size > MAX_PCAPS {
		hash := sessions[0].ID
		// delete the oldest session pcap file
		deletePcapFile(hash)
	}
}

func (pi *PcapImporter) progressUpdate(session ImportingSession, fileName string, completed bool, err string) {
	if completed {
		session.CompletedAt = time.Now()
	}
	session.ImportingError = err

	packetsPerService := session.PacketsPerService
	session.PacketsPerService = make(map[uint16]flowCount, len(packetsPerService))
	for key, value := range packetsPerService {
		session.PacketsPerService[key] = value
	}

	pi.mSessions.Lock()
	pi.sessions[session.ID] = session
	pi.mSessions.Unlock()

	if completed || session.ImportingError != "" {
		if _, _err := pi.storage.Insert(ImportingSessions).One(session); _err != nil {
			log.WithError(_err).WithField("session", session).Error("failed to insert importing stats")
		}
		if completed {
			moveProcessingFile(session.ID, fileName)
		} else {
			deleteProcessingFile(fileName)
		}
		close(session.completed)
	}
}

func (pi *PcapImporter) takeAssembler() *tcpassembly.Assembler {
	pi.mAssemblers.Lock()
	defer pi.mAssemblers.Unlock()

	if len(pi.assemblers) == 0 {
		return tcpassembly.NewAssembler(pi.streamPool)
	}

	index := len(pi.assemblers) - 1
	assembler := pi.assemblers[index]
	pi.assemblers = pi.assemblers[:index]

	return assembler
}

func (pi *PcapImporter) releaseAssembler(assembler *tcpassembly.Assembler) {
	pi.mAssemblers.Lock()
	pi.assemblers = append(pi.assemblers, assembler)
	pi.mAssemblers.Unlock()
}

func deleteProcessingFile(fileName string) {
	err := os.Remove(ProcessingPcapsBasePath + fileName)
	if err != nil {
		log.WithError(err).Error("failed to delete processing file")
	}
}

func deletePcapFile(fileName string) {
	err := os.Remove(PcapsBasePath + fileName)
	if err != nil {
		log.WithError(err).Error("failed to delete pcap file")
	}
}

func moveProcessingFile(sessionID string, oldFileName string) {
	oldExt := path.Ext(oldFileName)
	oldpath := ProcessingPcapsBasePath + oldFileName
	newpath := PcapsBasePath + sessionID + oldExt

	err := os.Rename(oldpath, newpath)
	if err != nil {
		log.WithError(err).Error("failed to move processed file")
	}
}