summaryrefslogtreecommitdiff
path: root/source3/nmbd/nmbd_subnetdb.c
blob: 7fd241cf624c58cc0f1f6b4d87b8b120fdf28cb3 (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
/* 
   Unix SMB/CIFS implementation.
   NBT netbios routines and daemon - version 2
   Copyright (C) Andrew Tridgell 1994-1998
   Copyright (C) Luke Kenneth Casson Leighton 1994-1998
   Copyright (C) Jeremy Allison 1994-1998
   
   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 3 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, see <http://www.gnu.org/licenses/>.
   
   Revision History:

*/

#include "includes.h"

extern int global_nmb_port;

/* This is the broadcast subnets database. */
struct subnet_record *subnetlist = NULL;

/* Extra subnets - keep these separate so enumeration code doesn't
   run onto it by mistake. */

struct subnet_record *unicast_subnet = NULL;
struct subnet_record *remote_broadcast_subnet = NULL;
struct subnet_record *wins_server_subnet = NULL;

extern uint16 samba_nb_type; /* Samba's NetBIOS name type. */

/****************************************************************************
  Add a subnet into the list.
  **************************************************************************/

static void add_subnet(struct subnet_record *subrec)
{
	DLIST_ADD(subnetlist, subrec);
}

/****************************************************************************
stop listening on a subnet
we don't free the record as we don't have proper reference counting for it
yet and it may be in use by a response record
  ****************************************************************************/

void close_subnet(struct subnet_record *subrec)
{
	if (subrec->dgram_sock != -1) {
		close(subrec->dgram_sock);
		subrec->dgram_sock = -1;
	}
	if (subrec->nmb_sock != -1) {
		close(subrec->nmb_sock);
		subrec->nmb_sock = -1;
	}

	DLIST_REMOVE(subnetlist, subrec);
}

/****************************************************************************
  Create a subnet entry.
  ****************************************************************************/

static struct subnet_record *make_subnet(const char *name, enum subnet_type type,
					 struct in_addr myip, struct in_addr bcast_ip, 
					 struct in_addr mask_ip)
{
	struct subnet_record *subrec = NULL;
	int nmb_sock, dgram_sock;

	/* Check if we are creating a non broadcast subnet - if so don't create
		sockets.  */

	if(type != NORMAL_SUBNET) {
		nmb_sock = -1;
		dgram_sock = -1;
	} else {
		/*
		 * Attempt to open the sockets on port 137/138 for this interface
		 * and bind them.
		 * Fail the subnet creation if this fails.
		 */

		if((nmb_sock = open_socket_in(SOCK_DGRAM, global_nmb_port,0, myip.s_addr,True)) == -1) {
			if( DEBUGLVL( 0 ) ) {
				Debug1( "nmbd_subnetdb:make_subnet()\n" );
				Debug1( "  Failed to open nmb socket on interface %s ", inet_ntoa(myip) );
				Debug1( "for port %d.  ", global_nmb_port );
				Debug1( "Error was %s\n", strerror(errno) );
			}
			return NULL;
		}

		if((dgram_sock = open_socket_in(SOCK_DGRAM,DGRAM_PORT,3, myip.s_addr,True)) == -1) {
			if( DEBUGLVL( 0 ) ) {
				Debug1( "nmbd_subnetdb:make_subnet()\n" );
				Debug1( "  Failed to open dgram socket on interface %s ", inet_ntoa(myip) );
				Debug1( "for port %d.  ", DGRAM_PORT );
				Debug1( "Error was %s\n", strerror(errno) );
			}
			return NULL;
		}

		/* Make sure we can broadcast from these sockets. */
		set_socket_options(nmb_sock,"SO_BROADCAST");
		set_socket_options(dgram_sock,"SO_BROADCAST");

		/* Set them non-blocking. */
		set_blocking(nmb_sock, False);
		set_blocking(dgram_sock, False);
	}

	subrec = SMB_MALLOC_P(struct subnet_record);
	if (!subrec) {
		DEBUG(0,("make_subnet: malloc fail !\n"));
		if (nmb_sock != -1) {
			close(nmb_sock);
		}
		if (dgram_sock != -1) {
			close(dgram_sock);
		}
		return(NULL);
	}
  
	ZERO_STRUCTP(subrec);

	if((subrec->subnet_name = SMB_STRDUP(name)) == NULL) {
		DEBUG(0,("make_subnet: malloc fail for subnet name !\n"));
		if (nmb_sock != -1) {
			close(nmb_sock);
		}
		if (dgram_sock != -1) {
			close(dgram_sock);
		}
		ZERO_STRUCTP(subrec);
		SAFE_FREE(subrec);
		return(NULL);
	}

	DEBUG(2, ("making subnet name:%s ", name ));
	DEBUG(2, ("Broadcast address:%s ", inet_ntoa(bcast_ip)));
	DEBUG(2, ("Subnet mask:%s\n", inet_ntoa(mask_ip)));
 
	subrec->namelist_changed = False;
	subrec->work_changed = False;
 
	subrec->bcast_ip = bcast_ip;
	subrec->mask_ip  = mask_ip;
	subrec->myip = myip;
	subrec->type = type;
	subrec->nmb_sock = nmb_sock;
	subrec->dgram_sock = dgram_sock;
  
	return subrec;
}

/****************************************************************************
  Create a normal subnet
**************************************************************************/

struct subnet_record *make_normal_subnet(const struct interface *iface)
{

	struct subnet_record *subrec;
	const struct in_addr *pip = &((const struct sockaddr_in *)&iface->ip)->sin_addr;
	const struct in_addr *pbcast = &((const struct sockaddr_in *)&iface->bcast)->sin_addr;
	const struct in_addr *pnmask = &((const struct sockaddr_in *)&iface->netmask)->sin_addr;

	subrec = make_subnet(inet_ntoa(*pip), NORMAL_SUBNET,
			     *pip, *pbcast, *pnmask);
	if (subrec) {
		add_subnet(subrec);
	}
	return subrec;
}

/****************************************************************************
  Create subnet entries.
**************************************************************************/

BOOL create_subnets(void)
{
	/* We only count IPv4 interfaces whilst we're waiting. */
	int num_interfaces = iface_count_v4();
	int i;
	struct in_addr unicast_ip, ipzero;

	if(num_interfaces == 0) {
		void (*saved_handler)(int);

		DEBUG(0,("create_subnets: No local interfaces !\n"));
		DEBUG(0,("create_subnets: Waiting for an interface to appear ...\n"));

		/*
		 * Whilst we're waiting for an interface, allow SIGTERM to
		 * cause us to exit.
		 */

		saved_handler = CatchSignal( SIGTERM, SIGNAL_CAST SIG_DFL );

		/* We only count IPv4 interfaces here. */
		while (iface_count_v4() == 0) {
			sleep(5);
			load_interfaces();
		}

		/*
		 * We got an interface, restore our normal term handler.
		 */

		CatchSignal( SIGTERM, SIGNAL_CAST saved_handler );
	}

	/*
	 * Here we count v4 and v6 - we know there's at least one
	 * IPv4 interface and we filter on it below.
	 */
	num_interfaces = iface_count();

	/*
	 * Create subnets from all the local interfaces and thread them onto
	 * the linked list.
	 */

	for (i = 0 ; i < num_interfaces; i++) {
		const struct interface *iface = get_interface(i);

		if (!iface) {
			DEBUG(2,("create_subnets: can't get interface %d.\n", i ));
			continue;
		}

		/* Ensure we're only dealing with IPv4 here. */
		if (iface->ip.ss_family != AF_INET) {
			DEBUG(2,("create_subnets: "
				"ignoring non IPv4 interface.\n"));
			continue;
		}

		/*
		 * We don't want to add a loopback interface, in case
		 * someone has added 127.0.0.1 for smbd, nmbd needs to
		 * ignore it here. JRA.
		 */

		if (is_loopback_addr(&iface->ip)) {
			DEBUG(2,("create_subnets: Ignoring loopback interface.\n" ));
			continue;
		}

		if (!make_normal_subnet(iface))
			return False;
	}

        /* We must have at least one subnet. */
	if (subnetlist == NULL) {
		DEBUG(0,("create_subnets: unable to create any subnet from "
				"given interfaces. nmbd is terminating\n"));
		return False;
	}

	if (lp_we_are_a_wins_server()) {
		/* Pick the first interface IPv4 address as the WINS server ip. */
		const struct in_addr *nip = first_ipv4_iface();

		if (!nip) {
			return False;
		}

		unicast_ip = *nip;
	} else {
		/* note that we do not set the wins server IP here. We just
			set it at zero and let the wins registration code cope
			with getting the IPs right for each packet */
		zero_ip_v4(&unicast_ip);
	}

	/*
	 * Create the unicast and remote broadcast subnets.
	 * Don't put these onto the linked list.
	 * The ip address of the unicast subnet is set to be
	 * the WINS server address, if it exists, or ipzero if not.
	 */

	unicast_subnet = make_subnet( "UNICAST_SUBNET", UNICAST_SUBNET, 
				unicast_ip, unicast_ip, unicast_ip);

	zero_ip_v4(&ipzero);

	remote_broadcast_subnet = make_subnet( "REMOTE_BROADCAST_SUBNET",
				REMOTE_BROADCAST_SUBNET,
				ipzero, ipzero, ipzero);

	if((unicast_subnet == NULL) || (remote_broadcast_subnet == NULL))
		return False;

	/* 
	 * If we are WINS server, create the WINS_SERVER_SUBNET - don't put on
	 * the linked list.
	 */

	if (lp_we_are_a_wins_server()) {
		if( (wins_server_subnet = make_subnet( "WINS_SERVER_SUBNET",
						WINS_SERVER_SUBNET, 
						ipzero, ipzero, ipzero )) == NULL )
			return False;
	}

	return True;
}

/*******************************************************************
Function to tell us if we can use the unicast subnet.
******************************************************************/

BOOL we_are_a_wins_client(void)
{
	if (wins_srv_count() > 0) {
		return True;
	}

	return False;
}

/*******************************************************************
Access function used by NEXT_SUBNET_INCLUDING_UNICAST
******************************************************************/

struct subnet_record *get_next_subnet_maybe_unicast(struct subnet_record *subrec)
{
	if(subrec == unicast_subnet)
		return NULL;
	else if((subrec->next == NULL) && we_are_a_wins_client())
		return unicast_subnet;
	else
		return subrec->next;
}

/*******************************************************************
 Access function used by retransmit_or_expire_response_records() in
 nmbd_packets.c. Patch from Andrey Alekseyev <fetch@muffin.arcadia.spb.ru>
 Needed when we need to enumerate all the broadcast, unicast and
 WINS subnets.
******************************************************************/

struct subnet_record *get_next_subnet_maybe_unicast_or_wins_server(struct subnet_record *subrec)
{
	if(subrec == unicast_subnet) {
		if(wins_server_subnet)
			return wins_server_subnet;
		else
			return NULL;
	}

	if(wins_server_subnet && subrec == wins_server_subnet)
		return NULL;

	if((subrec->next == NULL) && we_are_a_wins_client())
		return unicast_subnet;
	else
		return subrec->next;
}