summaryrefslogtreecommitdiff
path: root/source3/libsmb/namecache.c
blob: 7a0eb5212aa0faf3893aa716a387d2148253f64d (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
/* 
   Unix SMB/CIFS implementation.

   NetBIOS name cache module on top of gencache mechanism.
   
   Copyright (C) Tim Potter         2002
   Copyright (C) Rafal Szczesniak   2002
   
   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"

#define NBTKEY_FMT  "NBT/%s#%02X"


/**
 * Initialise namecache system. Function calls gencache
 * initialisation function to perform necessary actions
 * 
 * @return true upon successful initialisation of the cache or
 *         false on failure
 **/

BOOL namecache_enable(void)
{
	/*
	 * Check if name caching disabled by setting the name cache
	 * timeout to zero.
	 */ 

	if (lp_name_cache_timeout() == 0) {
		DEBUG(5, ("namecache_enable: disabling netbios name cache\n"));
		return False;
	}

	/* Init namecache by calling gencache initialisation */

	if (!gencache_init()) {
		DEBUG(2, ("namecache_enable: Couldn't initialise namecache on top of gencache.\n"));
		return False;
	}

	/* I leave it for now, though I don't think we really need this (mimir, 27.09.2002) */
	DEBUG(5, ("namecache_enable: enabling netbios namecache, timeout %d "
		  "seconds\n", lp_name_cache_timeout()));

	return True;
}


/**
 * Shutdown namecache. Routine calls gencache close function
 * to safely close gencache file.
 *
 * @return true upon successful shutdown of the cache or
 *         false on failure
 **/
 
BOOL namecache_shutdown(void)
{
	if (!gencache_shutdown()) {
		DEBUG(2, ("namecache_shutdown: Couldn't close namecache on top of gencache.\n"));
		return False;
	}
	
	DEBUG(5, ("namecache_shutdown: netbios namecache closed successfully.\n"));
	return True;
}


/**
 * Generates a key for netbios name lookups on basis of
 * netbios name and type.
 * The caller must free returned key string when finished.
 *
 * @param name netbios name string (case insensitive)
 * @param name_type netbios type of the name being looked up
 *
 * @return string consisted of uppercased name and appended
 *         type number
 */

static char* namecache_key(const char *name, int name_type)
{
	char *keystr;
	asprintf(&keystr, NBTKEY_FMT, strupper_static(name), name_type);

	return keystr;
}


/**
 * Store a name(s) in the name cache
 *
 * @param name netbios names array
 * @param name_type integer netbios name type
 * @param num_names number of names being stored
 * @param ip_list array of in_addr structures containing
 *        ip addresses being stored
 **/

BOOL namecache_store(const char *name, int name_type,
                     int num_names, struct in_addr *ip_list)
{
	time_t expiry;
	char *key, *value_string;
	int i;
	BOOL ret;

	/*
	 * we use gecache call to avoid annoying debug messages about
	 * initialised namecache again and again...
	 */
	if (!gencache_init()) return False;

	DEBUG(5, ("namecache_store: storing %d address%s for %s#%02x: ",
	          num_names, num_names == 1 ? "": "es", name, name_type));

	for (i = 0; i < num_names; i++) 
		DEBUGADD(5, ("%s%s", inet_ntoa(ip_list[i]),
		             i == (num_names - 1) ? "" : ", "));

	DEBUGADD(5, ("\n"));

	key = namecache_key(name, name_type);

	/* 
	 * Cache pdc location or dc lists for only a little while
	 * otherwise if we lock on to a bad DC we can potentially be
	 * out of action for the entire cache timeout time!
	 */

#if 0
	        /*
		 * I don't think we need to do this. We are
		 * checking at a higher level for failed DC
		 * connections. JRA.
		 */

	if (name_type == 0x1b || name_type == 0x1c)
		expiry = time(NULL) + 10;
	else
		expiry = time(NULL) + lp_name_cache_timeout();
#endif
	expiry = time(NULL) + lp_name_cache_timeout();

	/*
	 * Generate string representation of ip addresses list
	 * First, store the number of ip addresses and then
	 * place each single ip
	 */
	if (!ipstr_list_make(&value_string, ip_list, num_names)) {
		SAFE_FREE(key);
		SAFE_FREE(value_string);
		return False;
	}
	
	/* set the entry */
	ret = gencache_set(key, value_string, expiry);
	SAFE_FREE(key);
	SAFE_FREE(value_string);
	return ret;
}


/**
 * Look up a name in the cache.
 *
 * @param name netbios name to look up for
 * @param name_type netbios name type of @param name
 * @param ip_list mallocated list of IP addresses if found in the cache,
 *        NULL otherwise
 * @param num_names number of entries found
 *
 * @return true upon successful fetch or
 *         false if name isn't found in the cache or has expired
 **/

BOOL namecache_fetch(const char *name, int name_type, struct in_addr **ip_list,
                     int *num_names)
{
	char *key, *value;
	time_t timeout;

	*num_names = 0;

	/* exit now if null pointers were passed as they're required further */
	if (!ip_list || !num_names) return False;

	if (!gencache_init())
		return False;

	/* 
	 * Use gencache interface - lookup the key
	 */
	key = namecache_key(name, name_type);

	if (!gencache_get(key, &value, &timeout)) {
		DEBUG(5, ("no entry for %s#%02X found.\n", name, name_type));
		gencache_del(key);
		SAFE_FREE(key);
		SAFE_FREE(value);		 
		return False;
	} else {
		DEBUG(5, ("name %s#%02X found.\n", name, name_type));
	}
	
	/*
	 * Split up the stored value into the list of IP adresses
	 */
	*num_names = ipstr_list_parse(value, ip_list);
	
	SAFE_FREE(key);
	SAFE_FREE(value);		 
	return *num_names > 0;		/* true only if some ip has been fetched */
}


/**
 * Delete single namecache entry. Look at the
 * gencache_iterate definition.
 *
 **/

static void flush_netbios_name(const char* key, const char *value, time_t timeout, void* dptr)
{
	gencache_del(key);
	DEBUG(5, ("Deleting entry %s\n", key));
}


/**
 * Flush all names from the name cache.
 * It's done by gencache_iterate()
 *
 * @return True upon successful deletion or
 *         False in case of an error
 **/

void namecache_flush(void)
{
	if (!gencache_init())
		return;

	/* 
	 * iterate through each NBT cache's entry and flush it
	 * by flush_netbios_name function
	 */
	gencache_iterate(flush_netbios_name, NULL, "NBT/*");
	DEBUG(5, ("Namecache flushed\n"));
}

/* Construct a name status record key. */

static char *namecache_status_record_key(const char *name, int name_type1,
				int name_type2, struct in_addr keyip)
{
	char *keystr;

	asprintf(&keystr, "NBT/%s#%02X.%02X.%s",
			strupper_static(name), name_type1, name_type2, inet_ntoa(keyip));
	return keystr;
}

/* Store a name status record. */

BOOL namecache_status_store(const char *keyname, int keyname_type,
		int name_type, struct in_addr keyip,
		const char *srvname)
{
	char *key;
	time_t expiry;
	BOOL ret;

	if (!gencache_init())
		return False;

	key = namecache_status_record_key(keyname, keyname_type, name_type, keyip);
	if (!key)
		return False;

	expiry = time(NULL) + lp_name_cache_timeout();
	ret = gencache_set(key, srvname, expiry);

	if (ret)
		DEBUG(5, ("namecache_status_store: entry %s -> %s\n", key, srvname ));
	else
		DEBUG(5, ("namecache_status_store: entry %s store failed.\n", key ));

	SAFE_FREE(key);
	return ret;
}

/* Fetch a name status record. */

BOOL namecache_status_fetch(const char *keyname, int keyname_type,
			int name_type, struct in_addr keyip, char *srvname_out)
{
	char *key = NULL;
	char *value = NULL;
	time_t timeout;

	if (!gencache_init())
		return False;

	key = namecache_status_record_key(keyname, keyname_type, name_type, keyip);
	if (!key)
		return False;

	if (!gencache_get(key, &value, &timeout)) {
		DEBUG(5, ("namecache_status_fetch: no entry for %s found.\n", key));
		gencache_del(key);
		SAFE_FREE(key);
		SAFE_FREE(value);
		return False;
	} else {
		DEBUG(5, ("namecache_status_fetch: key %s -> %s\n", key, value ));
	}

	strlcpy(srvname_out, value, 16);
	SAFE_FREE(key);
	SAFE_FREE(value);
	return True;
}