source: branches/samba-3.3.x/source/libsmb/namecache.c

Last change on this file was 206, checked in by Herwig Bauernfeind, 16 years ago

Import Samba 3.3 branch at 3.0.0 level (psmedley's port)
File size: 8.5 KB
RevLine 
[206]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
36bool namecache_enable(void)
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 * Shutdown namecache. Routine calls gencache close function
66 * to safely close gencache file.
67 *
68 * @return true upon successful shutdown of the cache or
69 * false on failure
70 **/
71
72bool namecache_shutdown(void)
73{
74 if (!gencache_shutdown()) {
75 DEBUG(2, ("namecache_shutdown: "
76 "Couldn't close namecache on top of gencache.\n"));
77 return False;
78 }
79
80 DEBUG(5, ("namecache_shutdown: "
81 "netbios namecache closed successfully.\n"));
82 return True;
83}
84
85/**
86 * Generates a key for netbios name lookups on basis of
87 * netbios name and type.
88 * The caller must free returned key string when finished.
89 *
90 * @param name netbios name string (case insensitive)
91 * @param name_type netbios type of the name being looked up
92 *
93 * @return string consisted of uppercased name and appended
94 * type number
95 */
96
97static char* namecache_key(const char *name,
98 int name_type)
99{
100 char *keystr;
101 asprintf_strupper_m(&keystr, NBTKEY_FMT, name, name_type);
102
103 return keystr;
104}
105
106/**
107 * Store a name(s) in the name cache
108 *
109 * @param name netbios names array
110 * @param name_type integer netbios name type
111 * @param num_names number of names being stored
112 * @param ip_list array of in_addr structures containing
113 * ip addresses being stored
114 **/
115
116bool namecache_store(const char *name,
117 int name_type,
118 int num_names,
119 struct ip_service *ip_list)
120{
121 time_t expiry;
122 char *key, *value_string;
123 int i;
124 bool ret;
125
126 /*
127 * we use gecache call to avoid annoying debug messages about
128 * initialised namecache again and again...
129 */
130 if (!gencache_init()) {
131 return False;
132 }
133
134 if (name_type > 255) {
135 return False; /* Don't store non-real name types. */
136 }
137
138 if ( DEBUGLEVEL >= 5 ) {
139 TALLOC_CTX *ctx = talloc_stackframe();
140 char *addr = NULL;
141
142 DEBUG(5, ("namecache_store: storing %d address%s for %s#%02x: ",
143 num_names, num_names == 1 ? "": "es", name, name_type));
144
145 for (i = 0; i < num_names; i++) {
146 addr = print_canonical_sockaddr(ctx,
147 &ip_list[i].ss);
148 if (!addr) {
149 continue;
150 }
151 DEBUGADD(5, ("%s%s", addr,
152 (i == (num_names - 1) ? "" : ",")));
153
154 }
155 DEBUGADD(5, ("\n"));
156 TALLOC_FREE(ctx);
157 }
158
159 key = namecache_key(name, name_type);
160 if (!key) {
161 return False;
162 }
163
164 expiry = time(NULL) + lp_name_cache_timeout();
165
166 /*
167 * Generate string representation of ip addresses list
168 * First, store the number of ip addresses and then
169 * place each single ip
170 */
171 if (!ipstr_list_make(&value_string, ip_list, num_names)) {
172 SAFE_FREE(key);
173 SAFE_FREE(value_string);
174 return false;
175 }
176
177 /* set the entry */
178 ret = gencache_set(key, value_string, expiry);
179 SAFE_FREE(key);
180 SAFE_FREE(value_string);
181 return ret;
182}
183
184/**
185 * Look up a name in the cache.
186 *
187 * @param name netbios name to look up for
188 * @param name_type netbios name type of @param name
189 * @param ip_list mallocated list of IP addresses if found in the cache,
190 * NULL otherwise
191 * @param num_names number of entries found
192 *
193 * @return true upon successful fetch or
194 * false if name isn't found in the cache or has expired
195 **/
196
197bool namecache_fetch(const char *name,
198 int name_type,
199 struct ip_service **ip_list,
200 int *num_names)
201{
202 char *key, *value;
203 time_t timeout;
204
205 /* exit now if null pointers were passed as they're required further */
206 if (!ip_list || !num_names) {
207 return False;
208 }
209
210 if (!gencache_init()) {
211 return False;
212 }
213
214 if (name_type > 255) {
215 return False; /* Don't fetch non-real name types. */
216 }
217
218 *num_names = 0;
219
220 /*
221 * Use gencache interface - lookup the key
222 */
223 key = namecache_key(name, name_type);
224 if (!key) {
225 return False;
226 }
227
228 if (!gencache_get(key, &value, &timeout)) {
229 DEBUG(5, ("no entry for %s#%02X found.\n", name, name_type));
230 SAFE_FREE(key);
231 return False;
232 } else {
233 DEBUG(5, ("name %s#%02X found.\n", name, name_type));
234 }
235
236 /*
237 * Split up the stored value into the list of IP adresses
238 */
239 *num_names = ipstr_list_parse(value, ip_list);
240
241 SAFE_FREE(key);
242 SAFE_FREE(value);
243
244 return *num_names > 0; /* true only if some ip has been fetched */
245}
246
247/**
248 * Remove a namecache entry. Needed for site support.
249 *
250 **/
251
252bool namecache_delete(const char *name, int name_type)
253{
254 bool ret;
255 char *key;
256
257 if (!gencache_init())
258 return False;
259
260 if (name_type > 255) {
261 return False; /* Don't fetch non-real name types. */
262 }
263
264 key = namecache_key(name, name_type);
265 if (!key) {
266 return False;
267 }
268 ret = gencache_del(key);
269 SAFE_FREE(key);
270 return ret;
271}
272
273/**
274 * Delete single namecache entry. Look at the
275 * gencache_iterate definition.
276 *
277 **/
278
279static void flush_netbios_name(const char *key,
280 const char *value,
281 time_t timeout,
282 void *dptr)
283{
284 gencache_del(key);
285 DEBUG(5, ("Deleting entry %s\n", key));
286}
287
288/**
289 * Flush all names from the name cache.
290 * It's done by gencache_iterate()
291 *
292 * @return true upon successful deletion or
293 * false in case of an error
294 **/
295
296void namecache_flush(void)
297{
298 if (!gencache_init()) {
299 return;
300 }
301
302 /*
303 * iterate through each NBT cache's entry and flush it
304 * by flush_netbios_name function
305 */
306 gencache_iterate(flush_netbios_name, NULL, "NBT/*");
307 DEBUG(5, ("Namecache flushed\n"));
308}
309
310/* Construct a name status record key. */
311
312static char *namecache_status_record_key(const char *name,
313 int name_type1,
314 int name_type2,
315 const struct sockaddr_storage *keyip)
316{
317 char addr[INET6_ADDRSTRLEN];
318 char *keystr;
319
320 print_sockaddr(addr, sizeof(addr), keyip);
321 asprintf_strupper_m(&keystr, "NBT/%s#%02X.%02X.%s", name,
322 name_type1, name_type2, addr);
323 return keystr;
324}
325
326/* Store a name status record. */
327
328bool namecache_status_store(const char *keyname, int keyname_type,
329 int name_type, const struct sockaddr_storage *keyip,
330 const char *srvname)
331{
332 char *key;
333 time_t expiry;
334 bool ret;
335
336 if (!gencache_init()) {
337 return False;
338 }
339
340 key = namecache_status_record_key(keyname, keyname_type,
341 name_type, keyip);
342 if (!key)
343 return False;
344
345 expiry = time(NULL) + lp_name_cache_timeout();
346 ret = gencache_set(key, srvname, expiry);
347
348 if (ret) {
349 DEBUG(5, ("namecache_status_store: entry %s -> %s\n",
350 key, srvname ));
351 } else {
352 DEBUG(5, ("namecache_status_store: entry %s store failed.\n",
353 key ));
354 }
355
356 SAFE_FREE(key);
357 return ret;
358}
359
360/* Fetch a name status record. */
361
362bool namecache_status_fetch(const char *keyname,
363 int keyname_type,
364 int name_type,
365 const struct sockaddr_storage *keyip,
366 char *srvname_out)
367{
368 char *key = NULL;
369 char *value = NULL;
370 time_t timeout;
371
372 if (!gencache_init())
373 return False;
374
375 key = namecache_status_record_key(keyname, keyname_type,
376 name_type, keyip);
377 if (!key)
378 return False;
379
380 if (!gencache_get(key, &value, &timeout)) {
381 DEBUG(5, ("namecache_status_fetch: no entry for %s found.\n",
382 key));
383 SAFE_FREE(key);
384 return False;
385 } else {
386 DEBUG(5, ("namecache_status_fetch: key %s -> %s\n",
387 key, value ));
388 }
389
390 strlcpy(srvname_out, value, 16);
391 SAFE_FREE(key);
392 SAFE_FREE(value);
393 return True;
394}
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