summaryrefslogtreecommitdiff
path: root/source4/kdc/kdc.c
blob: 97f82460024880c981baea572d345efef37f936d (plain)
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
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
/* 
   Unix SMB/CIFS implementation.

   KDC Server startup

   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005
   Copyright (C) Andrew Tridgell	2005
   Copyright (C) Stefan Metzmacher	2005

   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; either version 2 of the License, or
   (at your option) any later version.
   
   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, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "includes.h"
#include "smbd/service_task.h"
#include "smbd/service.h"
#include "smbd/service_stream.h"
#include "smbd/process_model.h"
#include "lib/events/events.h"
#include "lib/socket/socket.h"
#include "kdc/kdc.h"
#include "system/network.h"
#include "dlinklist.h"
#include "lib/messaging/irpc.h"
#include "lib/stream/packet.h"
#include "librpc/gen_ndr/samr.h"
#include "netif/netif.h"

/* hold all the info needed to send a reply */
struct kdc_reply {
	struct kdc_reply *next, *prev;
	struct socket_address *dest;
	DATA_BLOB packet;
};

typedef BOOL (*kdc_process_fn_t)(struct kdc_server *kdc,
				 TALLOC_CTX *mem_ctx, 
				 DATA_BLOB *input, 
				 DATA_BLOB *reply,
				 struct socket_address *peer_addr, 
				 struct socket_address *my_addr);

/* hold information about one kdc socket */
struct kdc_socket {
	struct socket_context *sock;
	struct kdc_server *kdc;
	struct fd_event *fde;

	/* a queue of outgoing replies that have been deferred */
	struct kdc_reply *send_queue;

	kdc_process_fn_t process;
};
/*
  state of an open tcp connection
*/
struct kdc_tcp_connection {
	/* stream connection we belong to */
	struct stream_connection *conn;

	/* the kdc_server the connection belongs to */
	struct kdc_server *kdc;

	struct packet_context *packet;

	kdc_process_fn_t process;
};

/*
  handle fd send events on a KDC socket
*/
static void kdc_send_handler(struct kdc_socket *kdc_socket)
{
	while (kdc_socket->send_queue) {
		struct kdc_reply *rep = kdc_socket->send_queue;
		NTSTATUS status;
		size_t sendlen;

		status = socket_sendto(kdc_socket->sock, &rep->packet, &sendlen, 0,
				       rep->dest);
		if (NT_STATUS_EQUAL(status, STATUS_MORE_ENTRIES)) {
			break;
		}
		if (NT_STATUS_EQUAL(status, NT_STATUS_INVALID_BUFFER_SIZE)) {
			/* Replace with a krb err, response to big */
		}
		
		DLIST_REMOVE(kdc_socket->send_queue, rep);
		talloc_free(rep);
	}

	if (kdc_socket->send_queue == NULL) {
		EVENT_FD_NOT_WRITEABLE(kdc_socket->fde);
	}
}


/*
  handle fd recv events on a KDC socket
*/
static void kdc_recv_handler(struct kdc_socket *kdc_socket)
{
	NTSTATUS status;
	TALLOC_CTX *tmp_ctx = talloc_new(kdc_socket);
	DATA_BLOB blob;
	struct kdc_reply *rep;
	DATA_BLOB reply;
	size_t nread, dsize;
	struct socket_address *src;
	struct socket_address *my_addr;
	int ret;

	status = socket_pending(kdc_socket->sock, &dsize);
	if (!NT_STATUS_IS_OK(status)) {
		talloc_free(tmp_ctx);
		return;
	}

	blob = data_blob_talloc(kdc_socket, NULL, dsize);
	if (blob.data == NULL) {
		/* hope this is a temporary low memory condition */
		talloc_free(tmp_ctx);
		return;
	}

	status = socket_recvfrom(kdc_socket->sock, blob.data, blob.length, &nread, 0,
				 tmp_ctx, &src);
	if (!NT_STATUS_IS_OK(status)) {
		talloc_free(tmp_ctx);
		return;
	}
	blob.length = nread;
	
	DEBUG(10,("Received krb5 UDP packet of length %lu from %s:%u\n", 
		 (long)blob.length, src->addr, (uint16_t)src->port));
	
	my_addr = socket_get_my_addr(kdc_socket->sock, tmp_ctx);
	if (!my_addr) {
		talloc_free(tmp_ctx);
		return;
	}


	/* Call krb5 */
	ret = kdc_socket->process(kdc_socket->kdc, 
				  tmp_ctx, 
				  &blob,  
				  &reply,
				  src, my_addr);
	if (!ret) {
		talloc_free(tmp_ctx);
		return;
	}

	/* queue a pending reply */
	rep = talloc(kdc_socket, struct kdc_reply);
	if (rep == NULL) {
		talloc_free(tmp_ctx);
		return;
	}
	rep->dest         = talloc_steal(rep, src);
	rep->packet       = reply;
	talloc_steal(rep, reply.data);

	if (rep->packet.data == NULL) {
		talloc_free(rep);
		talloc_free(tmp_ctx);
		return;
	}

	DLIST_ADD_END(kdc_socket->send_queue, rep, struct kdc_reply *);
	EVENT_FD_WRITEABLE(kdc_socket->fde);
	talloc_free(tmp_ctx);
}

/*
  handle fd events on a KDC socket
*/
static void kdc_socket_handler(struct event_context *ev, struct fd_event *fde,
			       uint16_t flags, void *private)
{
	struct kdc_socket *kdc_socket = talloc_get_type(private, struct kdc_socket);
	if (flags & EVENT_FD_WRITE) {
		kdc_send_handler(kdc_socket);
	} 
	if (flags & EVENT_FD_READ) {
		kdc_recv_handler(kdc_socket);
	}
}

static void kdc_tcp_terminate_connection(struct kdc_tcp_connection *kdcconn, const char *reason)
{
	stream_terminate_connection(kdcconn->conn, reason);
}

/*
  receive a full packet on a KDC connection
*/
static NTSTATUS kdc_tcp_recv(void *private, DATA_BLOB blob)
{
	struct kdc_tcp_connection *kdcconn = talloc_get_type(private, 
							     struct kdc_tcp_connection);
	NTSTATUS status = NT_STATUS_UNSUCCESSFUL;
	TALLOC_CTX *tmp_ctx = talloc_new(kdcconn);
	int ret;
	DATA_BLOB input, reply;
	struct socket_address *src_addr;
	struct socket_address *my_addr;

	talloc_steal(tmp_ctx, blob.data);

	src_addr = socket_get_peer_addr(kdcconn->conn->socket, tmp_ctx);
	if (!src_addr) {
		talloc_free(tmp_ctx);
		return NT_STATUS_NO_MEMORY;
	}

	my_addr = socket_get_my_addr(kdcconn->conn->socket, tmp_ctx);
	if (!my_addr) {
		talloc_free(tmp_ctx);
		return NT_STATUS_NO_MEMORY;
	}

	/* Call krb5 */
	input = data_blob_const(blob.data + 4, blob.length - 4); 

	ret = kdcconn->process(kdcconn->kdc, 
			       tmp_ctx,
			       &input,
			       &reply,
			       src_addr,
			       my_addr);
	if (!ret) {
		talloc_free(tmp_ctx);
		return NT_STATUS_INTERNAL_ERROR;
	}

	/* and now encode the reply */
	blob = data_blob_talloc(kdcconn, NULL, reply.length + 4);
	if (!blob.data) {
		talloc_free(tmp_ctx);
		return NT_STATUS_NO_MEMORY;
	}

	RSIVAL(blob.data, 0, reply.length);
	memcpy(blob.data + 4, reply.data, reply.length);	

	status = packet_send(kdcconn->packet, blob);
	if (!NT_STATUS_IS_OK(status)) {
		talloc_free(tmp_ctx);
		return status;
	}

	/* the call isn't needed any more */
	talloc_free(tmp_ctx);
	return NT_STATUS_OK;
}

/*
  receive some data on a KDC connection
*/
static void kdc_tcp_recv_handler(struct stream_connection *conn, uint16_t flags)
{
	struct kdc_tcp_connection *kdcconn = talloc_get_type(conn->private, 
							     struct kdc_tcp_connection);
	packet_recv(kdcconn->packet);
}

/*
  called on a tcp recv error
*/
static void kdc_tcp_recv_error(void *private, NTSTATUS status)
{
	struct kdc_tcp_connection *kdcconn = talloc_get_type(private, struct kdc_tcp_connection);
	kdc_tcp_terminate_connection(kdcconn, nt_errstr(status));
}

/*
  called when we can write to a connection
*/
static void kdc_tcp_send(struct stream_connection *conn, uint16_t flags)
{
	struct kdc_tcp_connection *kdcconn = talloc_get_type(conn->private, 
							     struct kdc_tcp_connection);
	packet_queue_run(kdcconn->packet);
}

/**
   Wrapper for krb5_kdc_process_krb5_request, converting to/from Samba
   calling conventions
*/

static BOOL kdc_process(struct kdc_server *kdc,
			TALLOC_CTX *mem_ctx, 
			DATA_BLOB *input, 
			DATA_BLOB *reply,
			struct socket_address *peer_addr, 
			struct socket_address *my_addr)
{
	int ret;	
	krb5_data k5_reply;

	DEBUG(10,("Received KDC packet of length %lu from %s:%d\n", 
		  (long)input->length - 4, peer_addr->addr, peer_addr->port));

	ret = krb5_kdc_process_krb5_request(kdc->smb_krb5_context->krb5_context, 
					    kdc->config,
					    input->data, input->length,
					    &k5_reply,
					    peer_addr->addr,
					    peer_addr->sockaddr);
	if (ret == -1) {
		*reply = data_blob(NULL, 0);
		return False;
	}
	*reply = data_blob_talloc(mem_ctx, k5_reply.data, k5_reply.length);
	krb5_data_free(&k5_reply);
	return True;
}

/*
  called when we get a new connection
*/
static void kdc_tcp_generic_accept(struct stream_connection *conn, kdc_process_fn_t process_fn)
{
	struct kdc_server *kdc = talloc_get_type(conn->private, struct kdc_server);
	struct kdc_tcp_connection *kdcconn;

	kdcconn = talloc_zero(conn, struct kdc_tcp_connection);
	if (!kdcconn) {
		stream_terminate_connection(conn, "kdc_tcp_accept: out of memory");
		return;
	}
	kdcconn->conn	 = conn;
	kdcconn->kdc	 = kdc;
	kdcconn->process = process_fn;
	conn->private    = kdcconn;

	kdcconn->packet = packet_init(kdcconn);
	if (kdcconn->packet == NULL) {
		kdc_tcp_terminate_connection(kdcconn, "kdc_tcp_accept: out of memory");
		return;
	}
	packet_set_private(kdcconn->packet, kdcconn);
	packet_set_socket(kdcconn->packet, conn->socket);
	packet_set_callback(kdcconn->packet, kdc_tcp_recv);
	packet_set_full_request(kdcconn->packet, packet_full_request_u32);
	packet_set_error_handler(kdcconn->packet, kdc_tcp_recv_error);
	packet_set_event_context(kdcconn->packet, conn->event.ctx);
	packet_set_fde(kdcconn->packet, conn->event.fde);
	packet_set_serialise(kdcconn->packet);
}

static void kdc_tcp_accept(struct stream_connection *conn)
{
	kdc_tcp_generic_accept(conn, kdc_process);
}

static const struct stream_server_ops kdc_tcp_stream_ops = {
	.name			= "kdc_tcp",
	.accept_connection	= kdc_tcp_accept,
	.recv_handler		= kdc_tcp_recv_handler,
	.send_handler		= kdc_tcp_send
};

static void kpasswdd_tcp_accept(struct stream_connection *conn)
{
	kdc_tcp_generic_accept(conn, kpasswdd_process);
}

static const struct stream_server_ops kpasswdd_tcp_stream_ops = {
	.name			= "kpasswdd_tcp",
	.accept_connection	= kpasswdd_tcp_accept,
	.recv_handler		= kdc_tcp_recv_handler,
	.send_handler		= kdc_tcp_send
};

/*
  start listening on the given address
*/
static NTSTATUS kdc_add_socket(struct kdc_server *kdc, const char *address)
{
	const struct model_ops *model_ops;
 	struct kdc_socket *kdc_socket;
 	struct kdc_socket *kpasswd_socket;
	struct socket_address *kdc_address, *kpasswd_address;
	NTSTATUS status;
	uint16_t kdc_port = lp_krb5_port();
	uint16_t kpasswd_port = lp_kpasswd_port();

	kdc_socket = talloc(kdc, struct kdc_socket);
	NT_STATUS_HAVE_NO_MEMORY(kdc_socket);

	kpasswd_socket = talloc(kdc, struct kdc_socket);
	NT_STATUS_HAVE_NO_MEMORY(kpasswd_socket);

	status = socket_create("ip", SOCKET_TYPE_DGRAM, &kdc_socket->sock, 0);
	if (!NT_STATUS_IS_OK(status)) {
		talloc_free(kdc_socket);
		return status;
	}

	status = socket_create("ip", SOCKET_TYPE_DGRAM, &kpasswd_socket->sock, 0);
	if (!NT_STATUS_IS_OK(status)) {
		talloc_free(kpasswd_socket);
		return status;
	}

	kdc_socket->kdc = kdc;
	kdc_socket->send_queue = NULL;
	kdc_socket->process = kdc_process;

	talloc_steal(kdc_socket, kdc_socket->sock);

	kdc_socket->fde = event_add_fd(kdc->task->event_ctx, kdc, 
				       socket_get_fd(kdc_socket->sock), EVENT_FD_READ,
				       kdc_socket_handler, kdc_socket);

	kdc_address = socket_address_from_strings(kdc_socket, kdc_socket->sock->backend_name, 
						  address, kdc_port);
	NT_STATUS_HAVE_NO_MEMORY(kdc_address);

	status = socket_listen(kdc_socket->sock, kdc_address, 0, 0);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(0,("Failed to bind to %s:%d UDP for kdc - %s\n", 
			 address, kdc_port, nt_errstr(status)));
		talloc_free(kdc_socket);
		return status;
	}

	kpasswd_socket->kdc = kdc;
	kpasswd_socket->send_queue = NULL;
	kpasswd_socket->process = kpasswdd_process;

	talloc_steal(kpasswd_socket, kpasswd_socket->sock);

	kpasswd_socket->fde = event_add_fd(kdc->task->event_ctx, kdc, 
					   socket_get_fd(kpasswd_socket->sock), EVENT_FD_READ,
					   kdc_socket_handler, kpasswd_socket);
	
	kpasswd_address = socket_address_from_strings(kpasswd_socket, kpasswd_socket->sock->backend_name, 
						      address, kpasswd_port);
	NT_STATUS_HAVE_NO_MEMORY(kpasswd_address);

	status = socket_listen(kpasswd_socket->sock, kpasswd_address, 0, 0);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(0,("Failed to bind to %s:%d UDP for kpasswd - %s\n", 
			 address, kpasswd_port, nt_errstr(status)));
		talloc_free(kpasswd_socket);
		return status;
	}

	/* within the kdc task we want to be a single process, so
	   ask for the single process model ops and pass these to the
	   stream_setup_socket() call. */
	model_ops = process_model_byname("single");
	if (!model_ops) {
		DEBUG(0,("Can't find 'single' process model_ops\n"));
		talloc_free(kdc_socket);
		return NT_STATUS_INTERNAL_ERROR;
	}

	status = stream_setup_socket(kdc->task->event_ctx, model_ops, 
				     &kdc_tcp_stream_ops, 
				     "ip", address, &kdc_port, kdc);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
			 address, kdc_port, nt_errstr(status)));
		talloc_free(kdc_socket);
		return status;
	}

	status = stream_setup_socket(kdc->task->event_ctx, model_ops, 
				     &kpasswdd_tcp_stream_ops, 
				     "ip", address, &kpasswd_port, kdc);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
			 address, kpasswd_port, nt_errstr(status)));
		talloc_free(kdc_socket);
		return status;
	}

	return NT_STATUS_OK;
}


/*
  setup our listening sockets on the configured network interfaces
*/
static NTSTATUS kdc_startup_interfaces(struct kdc_server *kdc)
{
	int num_interfaces = iface_count();
	TALLOC_CTX *tmp_ctx = talloc_new(kdc);
	NTSTATUS status;
	
	int i;
	
	for (i=0; i<num_interfaces; i++) {
		const char *address = talloc_strdup(tmp_ctx, iface_n_ip(i));
		status = kdc_add_socket(kdc, address);
		NT_STATUS_NOT_OK_RETURN(status);
	}

	talloc_free(tmp_ctx);

	return NT_STATUS_OK;
}

/*
  startup the kdc task
*/
static void kdc_task_init(struct task_server *task)
{
	struct kdc_server *kdc;
	NTSTATUS status;
	krb5_error_code ret;

	switch (lp_server_role()) {
	case ROLE_STANDALONE:
		task_server_terminate(task, "kdc: no KDC required in standalone configuration");
		return;
	case ROLE_DOMAIN_MEMBER:
		task_server_terminate(task, "kdc: no KDC required in member server configuration");
		return;
	case ROLE_DOMAIN_PDC:
	case ROLE_DOMAIN_BDC:
		/* Yes, we want a KDC */
		break;
	}

	if (iface_count() == 0) {
		task_server_terminate(task, "kdc: no network interfaces configured");
		return;
	}

	kdc = talloc(task, struct kdc_server);
	if (kdc == NULL) {
		task_server_terminate(task, "kdc: out of memory");
		return;
	}

	kdc->task = task;

	/* Setup the KDC configuration */
	kdc->config = talloc(kdc, krb5_kdc_configuration);
	if (!kdc->config) {
		task_server_terminate(task, "kdc: out of memory");
		return;
	}
	krb5_kdc_default_config(kdc->config);

	initialize_krb5_error_table();

	ret = smb_krb5_init_context(kdc, &kdc->smb_krb5_context);
	if (ret) {
		DEBUG(1,("kdc_task_init: krb5_init_context failed (%s)\n", 
			 error_message(ret)));
		task_server_terminate(task, "kdc: krb5_init_context failed");
		return; 
	}

	krb5_add_et_list(kdc->smb_krb5_context->krb5_context, initialize_hdb_error_table_r);

	kdc->config->logf = kdc->smb_krb5_context->logf;
	kdc->config->db = talloc(kdc->config, struct HDB *);
	if (!kdc->config->db) {
		task_server_terminate(task, "kdc: out of memory");
		return;
	}
	kdc->config->num_db = 1;
		
	status = kdc_hdb_ldb_create(kdc, kdc->smb_krb5_context->krb5_context, 
				    &kdc->config->db[0], NULL);
	if (!NT_STATUS_IS_OK(status)) {
		task_server_terminate(task, "kdc: hdb_ldb_create (setup KDC database) failed");
		return; 
	}

	ret = krb5_kt_register(kdc->smb_krb5_context->krb5_context, &hdb_kt_ops);
	if(ret) {
		task_server_terminate(task, "kdc: failed to register hdb keytab");
		return;
	}
	/* start listening on the configured network interfaces */
	status = kdc_startup_interfaces(kdc);
	if (!NT_STATUS_IS_OK(status)) {
		task_server_terminate(task, "kdc failed to setup interfaces");
		return;
	}

	irpc_add_name(task->msg_ctx, "kdc_server");
}


/*
  called on startup of the KDC service 
*/
static NTSTATUS kdc_init(struct event_context *event_ctx, 
			 const struct model_ops *model_ops)
{	
	return task_server_startup(event_ctx, model_ops, kdc_task_init);
}

/* called at smbd startup - register ourselves as a server service */
NTSTATUS server_service_kdc_init(void)
{
	return register_server_service("kdc", kdc_init);
}