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DEFINITIONS
This source file includes following definitions.
- namecache_enable
- namecache_key
- namecache_store
- namecache_fetch
- namecache_delete
- flush_netbios_name
- namecache_flush
- namecache_status_record_key
- namecache_status_store
- namecache_status_fetch
1 /*
2 Unix SMB/CIFS implementation.
3
4 NetBIOS name cache module on top of gencache mechanism.
5
6 Copyright (C) Tim Potter 2002
7 Copyright (C) Rafal Szczesniak 2002
8 Copyright (C) Jeremy Allison 2007
9
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3 of the License, or
13 (at your option) any later version.
14
15 This program is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
19
20 You should have received a copy of the GNU General Public License
21 along with this program. If not, see <http://www.gnu.org/licenses/>.
22 */
23
24 #include "includes.h"
25
26 #define NBTKEY_FMT "NBT/%s#%02X"
27
28 /**
29 * Initialise namecache system. Function calls gencache
30 * initialisation function to perform necessary actions
31 *
32 * @return true upon successful initialisation of the cache or
33 * false on failure
34 **/
35
36 bool namecache_enable(void)
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37 {
38 /*
39 * Check if name caching disabled by setting the name cache
40 * timeout to zero.
41 */
42
43 if (lp_name_cache_timeout() == 0) {
44 DEBUG(5, ("namecache_enable: disabling netbios name cache\n"));
45 return False;
46 }
47
48 /* Init namecache by calling gencache initialisation */
49
50 if (!gencache_init()) {
51 DEBUG(2, ("namecache_enable: "
52 "Couldn't initialise namecache on top of gencache.\n"));
53 return False;
54 }
55
56 /* I leave it for now, though I don't think we really
57 * need this (mimir, 27.09.2002) */
58 DEBUG(5, ("namecache_enable: enabling netbios namecache, timeout %d "
59 "seconds\n", lp_name_cache_timeout()));
60
61 return True;
62 }
63
64 /**
65 * Generates a key for netbios name lookups on basis of
66 * netbios name and type.
67 * The caller must free returned key string when finished.
68 *
69 * @param name netbios name string (case insensitive)
70 * @param name_type netbios type of the name being looked up
71 *
72 * @return string consisted of uppercased name and appended
73 * type number
74 */
75
76 static char* namecache_key(const char *name,
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77 int name_type)
78 {
79 char *keystr;
80 asprintf_strupper_m(&keystr, NBTKEY_FMT, name, name_type);
81
82 return keystr;
83 }
84
85 /**
86 * Store a name(s) in the name cache
87 *
88 * @param name netbios names array
89 * @param name_type integer netbios name type
90 * @param num_names number of names being stored
91 * @param ip_list array of in_addr structures containing
92 * ip addresses being stored
93 **/
94
95 bool namecache_store(const char *name,
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96 int name_type,
97 int num_names,
98 struct ip_service *ip_list)
99 {
100 time_t expiry;
101 char *key, *value_string;
102 int i;
103 bool ret;
104
105 /*
106 * we use gecache call to avoid annoying debug messages about
107 * initialised namecache again and again...
108 */
109 if (!gencache_init()) {
110 return False;
111 }
112
113 if (name_type > 255) {
114 return False; /* Don't store non-real name types. */
115 }
116
117 if ( DEBUGLEVEL >= 5 ) {
118 TALLOC_CTX *ctx = talloc_stackframe();
119 char *addr = NULL;
120
121 DEBUG(5, ("namecache_store: storing %d address%s for %s#%02x: ",
122 num_names, num_names == 1 ? "": "es", name, name_type));
123
124 for (i = 0; i < num_names; i++) {
125 addr = print_canonical_sockaddr(ctx,
126 &ip_list[i].ss);
127 if (!addr) {
128 continue;
129 }
130 DEBUGADD(5, ("%s%s", addr,
131 (i == (num_names - 1) ? "" : ",")));
132
133 }
134 DEBUGADD(5, ("\n"));
135 TALLOC_FREE(ctx);
136 }
137
138 key = namecache_key(name, name_type);
139 if (!key) {
140 return False;
141 }
142
143 expiry = time(NULL) + lp_name_cache_timeout();
144
145 /*
146 * Generate string representation of ip addresses list
147 * First, store the number of ip addresses and then
148 * place each single ip
149 */
150 if (!ipstr_list_make(&value_string, ip_list, num_names)) {
151 SAFE_FREE(key);
152 SAFE_FREE(value_string);
153 return false;
154 }
155
156 /* set the entry */
157 ret = gencache_set(key, value_string, expiry);
158 SAFE_FREE(key);
159 SAFE_FREE(value_string);
160 return ret;
161 }
162
163 /**
164 * Look up a name in the cache.
165 *
166 * @param name netbios name to look up for
167 * @param name_type netbios name type of @param name
168 * @param ip_list mallocated list of IP addresses if found in the cache,
169 * NULL otherwise
170 * @param num_names number of entries found
171 *
172 * @return true upon successful fetch or
173 * false if name isn't found in the cache or has expired
174 **/
175
176 bool namecache_fetch(const char *name,
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177 int name_type,
178 struct ip_service **ip_list,
179 int *num_names)
180 {
181 char *key, *value;
182 time_t timeout;
183
184 /* exit now if null pointers were passed as they're required further */
185 if (!ip_list || !num_names) {
186 return False;
187 }
188
189 if (!gencache_init()) {
190 return False;
191 }
192
193 if (name_type > 255) {
194 return False; /* Don't fetch non-real name types. */
195 }
196
197 *num_names = 0;
198
199 /*
200 * Use gencache interface - lookup the key
201 */
202 key = namecache_key(name, name_type);
203 if (!key) {
204 return False;
205 }
206
207 if (!gencache_get(key, &value, &timeout)) {
208 DEBUG(5, ("no entry for %s#%02X found.\n", name, name_type));
209 SAFE_FREE(key);
210 return False;
211 } else {
212 DEBUG(5, ("name %s#%02X found.\n", name, name_type));
213 }
214
215 /*
216 * Split up the stored value into the list of IP adresses
217 */
218 *num_names = ipstr_list_parse(value, ip_list);
219
220 SAFE_FREE(key);
221 SAFE_FREE(value);
222
223 return *num_names > 0; /* true only if some ip has been fetched */
224 }
225
226 /**
227 * Remove a namecache entry. Needed for site support.
228 *
229 **/
230
231 bool namecache_delete(const char *name, int name_type)
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232 {
233 bool ret;
234 char *key;
235
236 if (!gencache_init())
237 return False;
238
239 if (name_type > 255) {
240 return False; /* Don't fetch non-real name types. */
241 }
242
243 key = namecache_key(name, name_type);
244 if (!key) {
245 return False;
246 }
247 ret = gencache_del(key);
248 SAFE_FREE(key);
249 return ret;
250 }
251
252 /**
253 * Delete single namecache entry. Look at the
254 * gencache_iterate definition.
255 *
256 **/
257
258 static void flush_netbios_name(const char *key,
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259 const char *value,
260 time_t timeout,
261 void *dptr)
262 {
263 gencache_del(key);
264 DEBUG(5, ("Deleting entry %s\n", key));
265 }
266
267 /**
268 * Flush all names from the name cache.
269 * It's done by gencache_iterate()
270 *
271 * @return true upon successful deletion or
272 * false in case of an error
273 **/
274
275 void namecache_flush(void)
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276 {
277 if (!gencache_init()) {
278 return;
279 }
280
281 /*
282 * iterate through each NBT cache's entry and flush it
283 * by flush_netbios_name function
284 */
285 gencache_iterate(flush_netbios_name, NULL, "NBT/*");
286 DEBUG(5, ("Namecache flushed\n"));
287 }
288
289 /* Construct a name status record key. */
290
291 static char *namecache_status_record_key(const char *name,
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292 int name_type1,
293 int name_type2,
294 const struct sockaddr_storage *keyip)
295 {
296 char addr[INET6_ADDRSTRLEN];
297 char *keystr;
298
299 print_sockaddr(addr, sizeof(addr), keyip);
300 asprintf_strupper_m(&keystr, "NBT/%s#%02X.%02X.%s", name,
301 name_type1, name_type2, addr);
302 return keystr;
303 }
304
305 /* Store a name status record. */
306
307 bool namecache_status_store(const char *keyname, int keyname_type,
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308 int name_type, const struct sockaddr_storage *keyip,
309 const char *srvname)
310 {
311 char *key;
312 time_t expiry;
313 bool ret;
314
315 if (!gencache_init()) {
316 return False;
317 }
318
319 key = namecache_status_record_key(keyname, keyname_type,
320 name_type, keyip);
321 if (!key)
322 return False;
323
324 expiry = time(NULL) + lp_name_cache_timeout();
325 ret = gencache_set(key, srvname, expiry);
326
327 if (ret) {
328 DEBUG(5, ("namecache_status_store: entry %s -> %s\n",
329 key, srvname ));
330 } else {
331 DEBUG(5, ("namecache_status_store: entry %s store failed.\n",
332 key ));
333 }
334
335 SAFE_FREE(key);
336 return ret;
337 }
338
339 /* Fetch a name status record. */
340
341 bool namecache_status_fetch(const char *keyname,
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342 int keyname_type,
343 int name_type,
344 const struct sockaddr_storage *keyip,
345 char *srvname_out)
346 {
347 char *key = NULL;
348 char *value = NULL;
349 time_t timeout;
350
351 if (!gencache_init())
352 return False;
353
354 key = namecache_status_record_key(keyname, keyname_type,
355 name_type, keyip);
356 if (!key)
357 return False;
358
359 if (!gencache_get(key, &value, &timeout)) {
360 DEBUG(5, ("namecache_status_fetch: no entry for %s found.\n",
361 key));
362 SAFE_FREE(key);
363 return False;
364 } else {
365 DEBUG(5, ("namecache_status_fetch: key %s -> %s\n",
366 key, value ));
367 }
368
369 strlcpy(srvname_out, value, 16);
370 SAFE_FREE(key);
371 SAFE_FREE(value);
372 return True;
373 }