summaryrefslogtreecommitdiffstats
path: root/server.go
blob: 35764756c68649f9e5b4526939f94a05a2822eea (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
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
package ldap

import (
	"crypto/tls"
	"io"
	"log"
	"net"
	"strings"
	"sync"

	"github.com/nmcclain/asn1-ber"
)

type Binder interface {
	Bind(bindDN, bindSimplePw string, conn net.Conn) (LDAPResultCode, error)
}
type Searcher interface {
	Search(boundDN string, req SearchRequest, conn net.Conn) (ServerSearchResult, error)
}
type Adder interface {
	Add(boundDN string, req AddRequest, conn net.Conn) (LDAPResultCode, error)
}
type Modifier interface {
	Modify(boundDN string, req ModifyRequest, conn net.Conn) (LDAPResultCode, error)
}
type Deleter interface {
	Delete(boundDN, deleteDN string, conn net.Conn) (LDAPResultCode, error)
}
type ModifyDNr interface {
	ModifyDN(boundDN string, req ModifyDNRequest, conn net.Conn) (LDAPResultCode, error)
}
type Comparer interface {
	Compare(boundDN string, req CompareRequest, conn net.Conn) (LDAPResultCode, error)
}
type Abandoner interface {
	Abandon(boundDN string, conn net.Conn) error
}
type Extender interface {
	Extended(boundDN string, req ExtendedRequest, conn net.Conn) (LDAPResultCode, error)
}
type Unbinder interface {
	Unbind(boundDN string, conn net.Conn) (LDAPResultCode, error)
}
type Closer interface {
	Close(boundDN string, conn net.Conn) error
}

//
type Server struct {
	BindFns     map[string]Binder
	SearchFns   map[string]Searcher
	AddFns      map[string]Adder
	ModifyFns   map[string]Modifier
	DeleteFns   map[string]Deleter
	ModifyDNFns map[string]ModifyDNr
	CompareFns  map[string]Comparer
	AbandonFns  map[string]Abandoner
	ExtendedFns map[string]Extender
	UnbindFns   map[string]Unbinder
	CloseFns    map[string]Closer
	Quit        chan bool
	EnforceLDAP bool
	Stats       *Stats
}

type Stats struct {
	Conns      int
	Binds      int
	Unbinds    int
	Searches   int
	statsMutex sync.Mutex
}

type ServerSearchResult struct {
	Entries    []*Entry
	Referrals  []string
	Controls   []Control
	ResultCode LDAPResultCode
}

//
func NewServer() *Server {
	s := new(Server)
	s.Quit = make(chan bool)

	d := defaultHandler{}
	s.BindFns = make(map[string]Binder)
	s.SearchFns = make(map[string]Searcher)
	s.AddFns = make(map[string]Adder)
	s.ModifyFns = make(map[string]Modifier)
	s.DeleteFns = make(map[string]Deleter)
	s.ModifyDNFns = make(map[string]ModifyDNr)
	s.CompareFns = make(map[string]Comparer)
	s.AbandonFns = make(map[string]Abandoner)
	s.ExtendedFns = make(map[string]Extender)
	s.UnbindFns = make(map[string]Unbinder)
	s.CloseFns = make(map[string]Closer)
	s.BindFunc("", d)
	s.SearchFunc("", d)
	s.AddFunc("", d)
	s.ModifyFunc("", d)
	s.DeleteFunc("", d)
	s.ModifyDNFunc("", d)
	s.CompareFunc("", d)
	s.AbandonFunc("", d)
	s.ExtendedFunc("", d)
	s.UnbindFunc("", d)
	s.CloseFunc("", d)
	s.Stats = nil
	return s
}
func (server *Server) BindFunc(baseDN string, f Binder) {
	server.BindFns[baseDN] = f
}
func (server *Server) SearchFunc(baseDN string, f Searcher) {
	server.SearchFns[baseDN] = f
}
func (server *Server) AddFunc(baseDN string, f Adder) {
	server.AddFns[baseDN] = f
}
func (server *Server) ModifyFunc(baseDN string, f Modifier) {
	server.ModifyFns[baseDN] = f
}
func (server *Server) DeleteFunc(baseDN string, f Deleter) {
	server.DeleteFns[baseDN] = f
}
func (server *Server) ModifyDNFunc(baseDN string, f ModifyDNr) {
	server.ModifyDNFns[baseDN] = f
}
func (server *Server) CompareFunc(baseDN string, f Comparer) {
	server.CompareFns[baseDN] = f
}
func (server *Server) AbandonFunc(baseDN string, f Abandoner) {
	server.AbandonFns[baseDN] = f
}
func (server *Server) ExtendedFunc(baseDN string, f Extender) {
	server.ExtendedFns[baseDN] = f
}
func (server *Server) UnbindFunc(baseDN string, f Unbinder) {
	server.UnbindFns[baseDN] = f
}
func (server *Server) CloseFunc(baseDN string, f Closer) {
	server.CloseFns[baseDN] = f
}
func (server *Server) QuitChannel(quit chan bool) {
	server.Quit = quit
}

func (server *Server) ListenAndServeTLS(listenString string, certFile string, keyFile string) error {
	cert, err := tls.LoadX509KeyPair(certFile, keyFile)
	if err != nil {
		return err
	}
	tlsConfig := tls.Config{Certificates: []tls.Certificate{cert}}
	tlsConfig.ServerName = "localhost"
	ln, err := tls.Listen("tcp", listenString, &tlsConfig)
	if err != nil {
		return err
	}
	err = server.Serve(ln)
	if err != nil {
		return err
	}
	return nil
}

func (server *Server) SetStats(enable bool) {
	if enable {
		server.Stats = &Stats{}
	} else {
		server.Stats = nil
	}
}

func (server *Server) GetStats() Stats {
	defer func() {
		server.Stats.statsMutex.Unlock()
	}()
	server.Stats.statsMutex.Lock()
	return *server.Stats
}

func (server *Server) ListenAndServe(listenString string) error {
	ln, err := net.Listen("tcp", listenString)
	if err != nil {
		return err
	}
	err = server.Serve(ln)
	if err != nil {
		return err
	}
	return nil
}

func (server *Server) Serve(ln net.Listener) error {
	newConn := make(chan net.Conn)
	go func() {
		for {
			conn, err := ln.Accept()
			if err != nil {
				if !strings.HasSuffix(err.Error(), "use of closed network connection") {
					log.Printf("Error accepting network connection: %s", err.Error())
				}
				break
			}
			newConn <- conn
		}
	}()

listener:
	for {
		select {
		case c := <-newConn:
			server.Stats.countConns(1)
			go server.handleConnection(c)
		case <-server.Quit:
			ln.Close()
			break listener
		}
	}
	return nil
}

//
func (server *Server) handleConnection(conn net.Conn) {
	boundDN := "" // "" == anonymous

handler:
	for {
		// read incoming LDAP packet
		packet, err := ber.ReadPacket(conn)
		if err == io.EOF { // Client closed connection
			break
		} else if err != nil {
			log.Printf("handleConnection ber.ReadPacket ERROR: %s", err.Error())
			break
		}

		// sanity check this packet
		if len(packet.Children) < 2 {
			log.Print("len(packet.Children) < 2")
			break
		}
		// check the message ID and ClassType
		messageID, ok := packet.Children[0].Value.(uint64)
		if !ok {
			log.Print("malformed messageID")
			break
		}
		req := packet.Children[1]
		if req.ClassType != ber.ClassApplication {
			log.Print("req.ClassType != ber.ClassApplication")
			break
		}
		// handle controls if present
		controls := []Control{}
		if len(packet.Children) > 2 {
			for _, child := range packet.Children[2].Children {
				controls = append(controls, DecodeControl(child))
			}
		}

		//log.Printf("DEBUG: handling operation: %s [%d]", ApplicationMap[req.Tag], req.Tag)
		//ber.PrintPacket(packet) // DEBUG

		// dispatch the LDAP operation
		switch req.Tag { // ldap op code
		default:
			responsePacket := encodeLDAPResponse(messageID, ApplicationAddResponse, LDAPResultOperationsError, "Unsupported operation: add")
			if err = sendPacket(conn, responsePacket); err != nil {
				log.Printf("sendPacket error %s", err.Error())
			}
			log.Printf("Unhandled operation: %s [%d]", ApplicationMap[req.Tag], req.Tag)
			break handler

		case ApplicationBindRequest:
			server.Stats.countBinds(1)
			ldapResultCode := HandleBindRequest(req, server.BindFns, conn)
			if ldapResultCode == LDAPResultSuccess {
				boundDN, ok = req.Children[1].Value.(string)
				if !ok {
					log.Printf("Malformed Bind DN")
					break handler
				}
			}
			responsePacket := encodeBindResponse(messageID, ldapResultCode)
			if err = sendPacket(conn, responsePacket); err != nil {
				log.Printf("sendPacket error %s", err.Error())
				break handler
			}
		case ApplicationSearchRequest:
			server.Stats.countSearches(1)
			if err := HandleSearchRequest(req, &controls, messageID, boundDN, server, conn); err != nil {
				log.Printf("handleSearchRequest error %s", err.Error()) // TODO: make this more testable/better err handling - stop using log, stop using breaks?
				e := err.(*Error)
				if err = sendPacket(conn, encodeSearchDone(messageID, e.ResultCode)); err != nil {
					log.Printf("sendPacket error %s", err.Error())
					break handler
				}
				break handler
			} else {
				if err = sendPacket(conn, encodeSearchDone(messageID, LDAPResultSuccess)); err != nil {
					log.Printf("sendPacket error %s", err.Error())
					break handler
				}
			}
		case ApplicationUnbindRequest:
			server.Stats.countUnbinds(1)
			break handler // simply disconnect
		case ApplicationExtendedRequest:
			ldapResultCode := HandleExtendedRequest(req, boundDN, server.ExtendedFns, conn)
			responsePacket := encodeLDAPResponse(messageID, ApplicationExtendedResponse, ldapResultCode, LDAPResultCodeMap[ldapResultCode])
			if err = sendPacket(conn, responsePacket); err != nil {
				log.Printf("sendPacket error %s", err.Error())
				break handler
			}
		case ApplicationAbandonRequest:
			HandleAbandonRequest(req, boundDN, server.AbandonFns, conn)
			break handler

		case ApplicationAddRequest:
			ldapResultCode := HandleAddRequest(req, boundDN, server.AddFns, conn)
			responsePacket := encodeLDAPResponse(messageID, ApplicationAddResponse, ldapResultCode, LDAPResultCodeMap[ldapResultCode])
			if err = sendPacket(conn, responsePacket); err != nil {
				log.Printf("sendPacket error %s", err.Error())
				break handler
			}
		case ApplicationModifyRequest:
			ldapResultCode := HandleModifyRequest(req, boundDN, server.ModifyFns, conn)
			responsePacket := encodeLDAPResponse(messageID, ApplicationModifyResponse, ldapResultCode, LDAPResultCodeMap[ldapResultCode])
			if err = sendPacket(conn, responsePacket); err != nil {
				log.Printf("sendPacket error %s", err.Error())
				break handler
			}
		case ApplicationDelRequest:
			ldapResultCode := HandleDeleteRequest(req, boundDN, server.DeleteFns, conn)
			responsePacket := encodeLDAPResponse(messageID, ApplicationDelResponse, ldapResultCode, LDAPResultCodeMap[ldapResultCode])
			if err = sendPacket(conn, responsePacket); err != nil {
				log.Printf("sendPacket error %s", err.Error())
				break handler
			}
		case ApplicationModifyDNRequest:
			ldapResultCode := HandleModifyDNRequest(req, boundDN, server.ModifyDNFns, conn)
			responsePacket := encodeLDAPResponse(messageID, ApplicationModifyDNResponse, ldapResultCode, LDAPResultCodeMap[ldapResultCode])
			if err = sendPacket(conn, responsePacket); err != nil {
				log.Printf("sendPacket error %s", err.Error())
				break handler
			}
		case ApplicationCompareRequest:
			ldapResultCode := HandleCompareRequest(req, boundDN, server.CompareFns, conn)
			responsePacket := encodeLDAPResponse(messageID, ApplicationCompareResponse, ldapResultCode, LDAPResultCodeMap[ldapResultCode])
			if err = sendPacket(conn, responsePacket); err != nil {
				log.Printf("sendPacket error %s", err.Error())
				break handler
			}
		}
	}

	for _, c := range server.CloseFns {
		c.Close(boundDN, conn)
	}

	conn.Close()
}

//
func sendPacket(conn net.Conn, packet *ber.Packet) error {
	_, err := conn.Write(packet.Bytes())
	if err != nil {
		log.Printf("Error Sending Message: %s", err.Error())
		return err
	}
	return nil
}

//
func routeFunc(dn string, funcNames []string) string {
	bestPick := ""
	for _, fn := range funcNames {
		if strings.HasSuffix(dn, fn) {
			l := len(strings.Split(bestPick, ","))
			if bestPick == "" {
				l = 0
			}
			if len(strings.Split(fn, ",")) > l {
				bestPick = fn
			}
		}
	}
	return bestPick
}

//
func encodeLDAPResponse(messageID uint64, responseType uint8, ldapResultCode LDAPResultCode, message string) *ber.Packet {
	responsePacket := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "LDAP Response")
	responsePacket.AppendChild(ber.NewInteger(ber.ClassUniversal, ber.TypePrimitive, ber.TagInteger, messageID, "Message ID"))
	reponse := ber.Encode(ber.ClassApplication, ber.TypeConstructed, responseType, nil, ApplicationMap[responseType])
	reponse.AppendChild(ber.NewInteger(ber.ClassUniversal, ber.TypePrimitive, ber.TagEnumerated, uint64(ldapResultCode), "resultCode: "))
	reponse.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, "", "matchedDN: "))
	reponse.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, message, "errorMessage: "))
	responsePacket.AppendChild(reponse)
	return responsePacket
}

//
type defaultHandler struct {
}

func (h defaultHandler) Bind(bindDN, bindSimplePw string, conn net.Conn) (LDAPResultCode, error) {
	return LDAPResultInvalidCredentials, nil
}
func (h defaultHandler) Search(boundDN string, req SearchRequest, conn net.Conn) (ServerSearchResult, error) {
	return ServerSearchResult{make([]*Entry, 0), []string{}, []Control{}, LDAPResultSuccess}, nil
}
func (h defaultHandler) Add(boundDN string, req AddRequest, conn net.Conn) (LDAPResultCode, error) {
	return LDAPResultInsufficientAccessRights, nil
}
func (h defaultHandler) Modify(boundDN string, req ModifyRequest, conn net.Conn) (LDAPResultCode, error) {
	return LDAPResultInsufficientAccessRights, nil
}
func (h defaultHandler) Delete(boundDN, deleteDN string, conn net.Conn) (LDAPResultCode, error) {
	return LDAPResultInsufficientAccessRights, nil
}
func (h defaultHandler) ModifyDN(boundDN string, req ModifyDNRequest, conn net.Conn) (LDAPResultCode, error) {
	return LDAPResultInsufficientAccessRights, nil
}
func (h defaultHandler) Compare(boundDN string, req CompareRequest, conn net.Conn) (LDAPResultCode, error) {
	return LDAPResultInsufficientAccessRights, nil
}
func (h defaultHandler) Abandon(boundDN string, conn net.Conn) error {
	return nil
}
func (h defaultHandler) Extended(boundDN string, req ExtendedRequest, conn net.Conn) (LDAPResultCode, error) {
	return LDAPResultProtocolError, nil
}
func (h defaultHandler) Unbind(boundDN string, conn net.Conn) (LDAPResultCode, error) {
	return LDAPResultSuccess, nil
}
func (h defaultHandler) Close(boundDN string, conn net.Conn) error {
	conn.Close()
	return nil
}

//
func (stats *Stats) countConns(delta int) {
	if stats != nil {
		stats.statsMutex.Lock()
		stats.Conns += delta
		stats.statsMutex.Unlock()
	}
}
func (stats *Stats) countBinds(delta int) {
	if stats != nil {
		stats.statsMutex.Lock()
		stats.Binds += delta
		stats.statsMutex.Unlock()
	}
}
func (stats *Stats) countUnbinds(delta int) {
	if stats != nil {
		stats.statsMutex.Lock()
		stats.Unbinds += delta
		stats.statsMutex.Unlock()
	}
}
func (stats *Stats) countSearches(delta int) {
	if stats != nil {
		stats.statsMutex.Lock()
		stats.Searches += delta
		stats.statsMutex.Unlock()
	}
}

//