summaryrefslogtreecommitdiff
path: root/source4/lib/socket/interface.c
blob: 00550a9ed4c5238807c104724b096e556f524c94 (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
/* 
   Unix SMB/CIFS implementation.

   multiple interface handling

   Copyright (C) Andrew Tridgell 1992-2005
   
   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 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/>.
*/

#include "includes.h"
#include "system/network.h"
#include "param/param.h"
#include "lib/socket/netif.h"
#include "../lib/util/util_net.h"
#include "../lib/util/dlinklist.h"

/* used for network interfaces */
struct interface {
	struct interface *next, *prev;
	char *name;
	int flags;
	struct sockaddr_storage ip;
	struct sockaddr_storage netmask;
	struct sockaddr_storage bcast;
	const char *ip_s;
	const char *bcast_s;
	const char *nmask_s;
};

#define ALLONES  ((uint32_t)0xFFFFFFFF)
/*
  address construction based on a patch from fred@datalync.com
*/
#define MKBCADDR(_IP, _NM) ((_IP & _NM) | (_NM ^ ALLONES))
#define MKNETADDR(_IP, _NM) (_IP & _NM)

/****************************************************************************
Try and find an interface that matches an ip. If we cannot, return NULL
  **************************************************************************/
static struct interface *iface_list_find(struct interface *interfaces,
					 const struct sockaddr *ip,
					 bool check_mask)
{
	struct interface *i;

	if (is_address_any(ip)) {
		return interfaces;
	}

	for (i=interfaces;i;i=i->next) {
		if (check_mask) {
			if (same_net(ip, (struct sockaddr *)&i->ip, (struct sockaddr *)&i->netmask)) {
				return i;
			}
		} else if (sockaddr_equal((struct sockaddr *)&i->ip, ip)) {
			return i;
		}
	}

	return NULL;
}

/****************************************************************************
add an interface to the linked list of interfaces
****************************************************************************/
static void add_interface(TALLOC_CTX *mem_ctx, const struct iface_struct *ifs, struct interface **interfaces,
			  bool enable_ipv6)
{
	char addr[INET6_ADDRSTRLEN];
	struct interface *iface;

	if (iface_list_find(*interfaces, (const struct sockaddr *)&ifs->ip, false)) {
		DEBUG(3,("add_interface: not adding duplicate interface %s\n",
			print_sockaddr(addr, sizeof(addr), &ifs->ip) ));
		return;
	}

	if (!(ifs->flags & (IFF_BROADCAST|IFF_LOOPBACK))) {
		DEBUG(3,("not adding non-broadcast interface %s\n",
					ifs->name ));
		return;
	}

	if (!enable_ipv6 && ifs->ip.ss_family != AF_INET) {
		return;
	}

	iface = talloc(*interfaces == NULL ? mem_ctx : *interfaces, struct interface);
	if (iface == NULL) 
		return;
	
	ZERO_STRUCTPN(iface);

	iface->name = talloc_strdup(iface, ifs->name);
	if (!iface->name) {
		SAFE_FREE(iface);
		return;
	}
	iface->flags = ifs->flags;
	iface->ip = ifs->ip;
	iface->netmask = ifs->netmask;
	iface->bcast = ifs->bcast;

	/* keep string versions too, to avoid people tripping over the implied
	   static in inet_ntoa() */
	print_sockaddr(addr, sizeof(addr), &iface->ip);
	DEBUG(2,("added interface %s ip=%s ",
		 iface->name, addr));
	iface->ip_s = talloc_strdup(iface, addr);

	print_sockaddr(addr, sizeof(addr),
		       &iface->bcast);
	DEBUG(2,("bcast=%s ", addr));
	iface->bcast_s = talloc_strdup(iface, addr);

	print_sockaddr(addr, sizeof(addr),
		       &iface->netmask);
	DEBUG(2,("netmask=%s\n", addr));
	iface->nmask_s = talloc_strdup(iface, addr);

	/*
	   this needs to be a ADD_END, as some tests (such as the
	   spoolss notify test) depend on the interfaces ordering
	*/
	DLIST_ADD_END(*interfaces, iface, NULL);
}

/**
interpret a single element from a interfaces= config line 

This handles the following different forms:

1) wildcard interface name
2) DNS name
3) IP/masklen
4) ip/mask
5) bcast/mask
**/
static void interpret_interface(TALLOC_CTX *mem_ctx, 
				const char *token, 
				struct iface_struct *probed_ifaces, 
				int total_probed,
				struct interface **local_interfaces,
				bool enable_ipv6)
{
	struct sockaddr_storage ss;
	struct sockaddr_storage ss_mask;
	struct sockaddr_storage ss_net;
	struct sockaddr_storage ss_bcast;
	struct iface_struct ifs;
	char *p;
	int i;
	bool added=false;
	bool goodaddr = false;

	/* first check if it is an interface name */
	for (i=0;i<total_probed;i++) {
		if (gen_fnmatch(token, probed_ifaces[i].name) == 0) {
			add_interface(mem_ctx, &probed_ifaces[i],
				      local_interfaces, enable_ipv6);
			added = true;
		}
	}
	if (added) {
		return;
	}

	/* maybe it is a DNS name */
	p = strchr_m(token,'/');
	if (p == NULL) {
		if (!interpret_string_addr(&ss, token, 0)) {
			DEBUG(2, ("interpret_interface: Can't find address "
				  "for %s\n", token));
			return;
		}

		for (i=0;i<total_probed;i++) {
			if (sockaddr_equal((struct sockaddr *)&ss, (struct sockaddr *)&probed_ifaces[i].ip)) {
				add_interface(mem_ctx, &probed_ifaces[i],
					      local_interfaces, enable_ipv6);
				return;
			}
		}
		DEBUG(2,("interpret_interface: "
			"can't determine interface for %s\n",
			token));
		return;
	}

	/* parse it into an IP address/netmasklength pair */
	*p = 0;
	goodaddr = interpret_string_addr(&ss, token, 0);
	*p++ = '/';

	if (!goodaddr) {
		DEBUG(2,("interpret_interface: "
			"can't determine interface for %s\n",
			token));
		return;
	}

	if (strlen(p) > 2) {
		goodaddr = interpret_string_addr(&ss_mask, p, 0);
		if (!goodaddr) {
			DEBUG(2,("interpret_interface: "
				"can't determine netmask from %s\n",
				p));
			return;
		}
	} else {
		char *endp = NULL;
		unsigned long val = strtoul(p, &endp, 0);
		if (p == endp || (endp && *endp != '\0')) {
			DEBUG(2,("interpret_interface: "
				"can't determine netmask value from %s\n",
				p));
			return;
		}
		if (!make_netmask(&ss_mask, &ss, val)) {
			DEBUG(2,("interpret_interface: "
				"can't apply netmask value %lu from %s\n",
				val,
				p));
			return;
		}
	}

	make_bcast(&ss_bcast, &ss, &ss_mask);
	make_net(&ss_net, &ss, &ss_mask);

	/* Maybe the first component was a broadcast address. */
	if (sockaddr_equal((struct sockaddr *)&ss_bcast, (struct sockaddr *)&ss) ||
		sockaddr_equal((struct sockaddr *)&ss_net, (struct sockaddr *)&ss)) {
		for (i=0;i<total_probed;i++) {
			if (same_net((struct sockaddr *)&ss,
						 (struct sockaddr *)&probed_ifaces[i].ip,
						 (struct sockaddr *)&ss_mask)) {
				/* Temporarily replace netmask on
				 * the detected interface - user knows
				 * best.... */
				struct sockaddr_storage saved_mask =
					probed_ifaces[i].netmask;
				probed_ifaces[i].netmask = ss_mask;
				DEBUG(2,("interpret_interface: "
					"using netmask value %s from "
					"config file on interface %s\n",
					p,
					probed_ifaces[i].name));
				add_interface(mem_ctx, &probed_ifaces[i],
					      local_interfaces, enable_ipv6);
				probed_ifaces[i].netmask = saved_mask;
				return;
			}
		}
		DEBUG(2,("interpret_interface: Can't determine ip for "
			"broadcast address %s\n",
			token));
		return;
	}

	/* Just fake up the interface definition. User knows best. */

	DEBUG(2,("interpret_interface: Adding interface %s\n",
		token));

	ZERO_STRUCT(ifs);
	(void)strlcpy(ifs.name, token, sizeof(ifs.name));
	ifs.flags = IFF_BROADCAST;
	ifs.ip = ss;
	ifs.netmask = ss_mask;
	ifs.bcast = ss_bcast;
	add_interface(mem_ctx, &ifs,
		      local_interfaces, enable_ipv6);
}


/**
load the list of network interfaces
**/
void load_interface_list(TALLOC_CTX *mem_ctx, struct loadparm_context *lp_ctx, struct interface **local_interfaces)
{
	const char **ptr = lpcfg_interfaces(lp_ctx);
	int i;
	struct iface_struct *ifaces;
	int total_probed;
	bool enable_ipv6 = lpcfg_parm_bool(lp_ctx, NULL, "ipv6", "enable", false);

	*local_interfaces = NULL;

	/* probe the kernel for interfaces */
	total_probed = get_interfaces(mem_ctx, &ifaces);

	/* if we don't have a interfaces line then use all interfaces
	   except loopback */
	if (!ptr || !*ptr || !**ptr) {
		if (total_probed <= 0) {
			DEBUG(0,("ERROR: Could not determine network interfaces, you must use a interfaces config line\n"));
		}
		for (i=0;i<total_probed;i++) {
			if (!is_loopback_addr((struct sockaddr *)&ifaces[i].ip)) {
				add_interface(mem_ctx, &ifaces[i], local_interfaces, enable_ipv6);
			}
		}
	}

	while (ptr && *ptr) {
		interpret_interface(mem_ctx, *ptr, ifaces, total_probed, local_interfaces, enable_ipv6);
		ptr++;
	}

	if (!*local_interfaces) {
		DEBUG(0,("WARNING: no network interfaces found\n"));
	}
	talloc_free(ifaces);
}

/**
  how many interfaces do we have
  **/
int iface_list_count(struct interface *ifaces)
{
	int ret = 0;
	struct interface *i;

	for (i=ifaces;i;i=i->next)
		ret++;
	return ret;
}

/**
  return IP of the Nth interface
  **/
const char *iface_list_n_ip(struct interface *ifaces, int n)
{
	struct interface *i;
  
	for (i=ifaces;i && n;i=i->next)
		n--;

	if (i) {
		return i->ip_s;
	}
	return NULL;
}


/**
  return the first IPv4 interface address we have registered
  **/
const char *iface_list_first_v4(struct interface *ifaces)
{
	struct interface *i;

	for (i=ifaces; i; i=i->next) {
		if (i->ip.ss_family == AF_INET) {
			return i->ip_s;
		}
	}
	return NULL;
}

/**
   check if an interface is IPv4
  **/
bool iface_list_n_is_v4(struct interface *ifaces, int n)
{
	struct interface *i;

	for (i=ifaces;i && n;i=i->next)
		n--;

	if (i) {
		return i->ip.ss_family == AF_INET;
	}
	return false;
}

/**
  return bcast of the Nth interface
  **/
const char *iface_list_n_bcast(struct interface *ifaces, int n)
{
	struct interface *i;
  
	for (i=ifaces;i && n;i=i->next)
		n--;

	if (i) {
		return i->bcast_s;
	}
	return NULL;
}

/**
  return netmask of the Nth interface
  **/
const char *iface_list_n_netmask(struct interface *ifaces, int n)
{
	struct interface *i;
  
	for (i=ifaces;i && n;i=i->next)
		n--;

	if (i) {
		return i->nmask_s;
	}
	return NULL;
}

/**
  return the local IP address that best matches a destination IP, or
  our first interface if none match
*/
const char *iface_list_best_ip(struct interface *ifaces, const char *dest)
{
	struct interface *iface;
	struct sockaddr_storage ss;

	if (!interpret_string_addr(&ss, dest, AI_NUMERICHOST)) {
		return iface_list_n_ip(ifaces, 0);
	}
	iface = iface_list_find(ifaces, (const struct sockaddr *)&ss, true);
	if (iface) {
		return iface->ip_s;
	}
	return iface_list_n_ip(ifaces, 0);
}

/**
  return true if an IP is one one of our local networks
*/
bool iface_list_is_local(struct interface *ifaces, const char *dest)
{
	struct sockaddr_storage ss;

	if (!interpret_string_addr(&ss, dest, AI_NUMERICHOST)) {
		return false;
	}
	if (iface_list_find(ifaces, (const struct sockaddr *)&ss, true)) {
		return true;
	}
	return false;
}

/**
  return true if a IP matches a IP/netmask pair
*/
bool iface_list_same_net(const char *ip1, const char *ip2, const char *netmask)
{
	return same_net_v4(interpret_addr2(ip1),
			interpret_addr2(ip2),
			interpret_addr2(netmask));
}

/**
   return the list of wildcard interfaces
   this will include the IPv4 0.0.0.0, and may include IPv6 ::
   it is overridden by the 'socket address' option in smb.conf
*/
const char **iface_list_wildcard(TALLOC_CTX *mem_ctx, struct loadparm_context *lp_ctx)
{
	const char **ret;
	const char *socket_address;

	/* the user may have configured a specific address */
	socket_address = lpcfg_socket_address(lp_ctx);
	if (strcmp(socket_address, "") != 0) {
		ret = (const char **)str_list_make(mem_ctx, socket_address, NULL);
		return ret;
	}

	ret = (const char **)str_list_make(mem_ctx, "0.0.0.0", NULL);
	if (ret == NULL) return NULL;

#ifdef HAVE_IPV6
	if (lpcfg_parm_bool(lp_ctx, NULL, "ipv6", "enable", false)) {
		return str_list_add(ret, "::");
	}
#endif

	return ret;
}