source: branches/samba-3.0/source/libsmb/namecache.c@ 621

Last change on this file since 621 was 1, checked in by Paul Smedley, 19 years ago

Initial code import
File size: 8.2 KB
Line 
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
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2 of the License, or
12 (at your option) any later version.
13
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
18
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22*/
23
24#include "includes.h"
25
26#define NBTKEY_FMT "NBT/%s#%02X"
27
28
29/**
30 * Initialise namecache system. Function calls gencache
31 * initialisation function to perform necessary actions
32 *
33 * @return true upon successful initialisation of the cache or
34 * false on failure
35 **/
36
37BOOL namecache_enable(void)
38{
39 /*
40 * Check if name caching disabled by setting the name cache
41 * timeout to zero.
42 */
43
44 if (lp_name_cache_timeout() == 0) {
45 DEBUG(5, ("namecache_enable: disabling netbios name cache\n"));
46 return False;
47 }
48
49 /* Init namecache by calling gencache initialisation */
50
51 if (!gencache_init()) {
52 DEBUG(2, ("namecache_enable: 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 need this (mimir, 27.09.2002) */
57 DEBUG(5, ("namecache_enable: enabling netbios namecache, timeout %d "
58 "seconds\n", lp_name_cache_timeout()));
59
60 return True;
61}
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: Couldn't close namecache on top of gencache.\n"));
76 return False;
77 }
78
79 DEBUG(5, ("namecache_shutdown: netbios namecache closed successfully.\n"));
80 return True;
81}
82
83
84/**
85 * Generates a key for netbios name lookups on basis of
86 * netbios name and type.
87 * The caller must free returned key string when finished.
88 *
89 * @param name netbios name string (case insensitive)
90 * @param name_type netbios type of the name being looked up
91 *
92 * @return string consisted of uppercased name and appended
93 * type number
94 */
95
96static char* namecache_key(const char *name, int name_type)
97{
98 char *keystr;
99 asprintf(&keystr, NBTKEY_FMT, strupper_static(name), name_type);
100
101 return keystr;
102}
103
104
105/**
106 * Store a name(s) in the name cache
107 *
108 * @param name netbios names array
109 * @param name_type integer netbios name type
110 * @param num_names number of names being stored
111 * @param ip_list array of in_addr structures containing
112 * ip addresses being stored
113 **/
114
115BOOL namecache_store(const char *name, int name_type,
116 int num_names, struct ip_service *ip_list)
117{
118 time_t expiry;
119 char *key, *value_string;
120 int i;
121 BOOL ret;
122
123 /*
124 * we use gecache call to avoid annoying debug messages about
125 * initialised namecache again and again...
126 */
127 if (!gencache_init()) return False;
128
129 if (name_type > 255) {
130 return False; /* Don't store non-real name types. */
131 }
132
133 if ( DEBUGLEVEL >= 5 ) {
134 DEBUG(5, ("namecache_store: storing %d address%s for %s#%02x: ",
135 num_names, num_names == 1 ? "": "es", name, name_type));
136
137 for (i = 0; i < num_names; i++)
138 DEBUGADD(5, ("%s:%d%s", inet_ntoa(ip_list[i].ip),
139 ip_list[i].port, (i == (num_names - 1) ? "" : ",")));
140
141 DEBUGADD(5, ("\n"));
142 }
143
144 key = namecache_key(name, name_type);
145 if (!key) {
146 return False;
147 }
148
149 expiry = time(NULL) + lp_name_cache_timeout();
150
151 /*
152 * Generate string representation of ip addresses list
153 * First, store the number of ip addresses and then
154 * place each single ip
155 */
156 if (!ipstr_list_make(&value_string, ip_list, num_names)) {
157 SAFE_FREE(key);
158 SAFE_FREE(value_string);
159 return False;
160 }
161
162 /* set the entry */
163 ret = gencache_set(key, value_string, expiry);
164 SAFE_FREE(key);
165 SAFE_FREE(value_string);
166 return ret;
167}
168
169
170/**
171 * Look up a name in the cache.
172 *
173 * @param name netbios name to look up for
174 * @param name_type netbios name type of @param name
175 * @param ip_list mallocated list of IP addresses if found in the cache,
176 * NULL otherwise
177 * @param num_names number of entries found
178 *
179 * @return true upon successful fetch or
180 * false if name isn't found in the cache or has expired
181 **/
182
183BOOL namecache_fetch(const char *name, int name_type, struct ip_service **ip_list,
184 int *num_names)
185{
186 char *key, *value;
187 time_t timeout;
188
189 /* exit now if null pointers were passed as they're required further */
190 if (!ip_list || !num_names) return False;
191
192 if (!gencache_init())
193 return False;
194
195 if (name_type > 255) {
196 return False; /* Don't fetch non-real name types. */
197 }
198
199 *num_names = 0;
200
201 /*
202 * Use gencache interface - lookup the key
203 */
204 key = namecache_key(name, name_type);
205 if (!key) {
206 return False;
207 }
208
209 if (!gencache_get(key, &value, &timeout)) {
210 DEBUG(5, ("no entry for %s#%02X found.\n", name, name_type));
211 SAFE_FREE(key);
212 return False;
213 } else {
214 DEBUG(5, ("name %s#%02X found.\n", name, name_type));
215 }
216
217 /*
218 * Split up the stored value into the list of IP adresses
219 */
220 *num_names = ipstr_list_parse(value, ip_list);
221
222 SAFE_FREE(key);
223 SAFE_FREE(value);
224
225 return *num_names > 0; /* true only if some ip has been fetched */
226}
227
228/**
229 * Remove a namecache entry. Needed for site support.
230 *
231 **/
232
233BOOL namecache_delete(const char *name, int name_type)
234{
235 BOOL ret;
236 char *key;
237
238 if (!gencache_init())
239 return False;
240
241 if (name_type > 255) {
242 return False; /* Don't fetch non-real name types. */
243 }
244
245 key = namecache_key(name, name_type);
246 if (!key) {
247 return False;
248 }
249 ret = gencache_del(key);
250 SAFE_FREE(key);
251 return ret;
252}
253
254/**
255 * Delete single namecache entry. Look at the
256 * gencache_iterate definition.
257 *
258 **/
259
260static void flush_netbios_name(const char* key, const char *value, time_t timeout, void* dptr)
261{
262 gencache_del(key);
263 DEBUG(5, ("Deleting entry %s\n", key));
264}
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
275void namecache_flush(void)
276{
277 if (!gencache_init())
278 return;
279
280 /*
281 * iterate through each NBT cache's entry and flush it
282 * by flush_netbios_name function
283 */
284 gencache_iterate(flush_netbios_name, NULL, "NBT/*");
285 DEBUG(5, ("Namecache flushed\n"));
286}
287
288/* Construct a name status record key. */
289
290static char *namecache_status_record_key(const char *name, int name_type1,
291 int name_type2, struct in_addr keyip)
292{
293 char *keystr;
294
295 asprintf(&keystr, "NBT/%s#%02X.%02X.%s",
296 strupper_static(name), name_type1, name_type2, inet_ntoa(keyip));
297 return keystr;
298}
299
300/* Store a name status record. */
301
302BOOL namecache_status_store(const char *keyname, int keyname_type,
303 int name_type, struct in_addr keyip,
304 const char *srvname)
305{
306 char *key;
307 time_t expiry;
308 BOOL ret;
309
310 if (!gencache_init())
311 return False;
312
313 key = namecache_status_record_key(keyname, keyname_type, name_type, keyip);
314 if (!key)
315 return False;
316
317 expiry = time(NULL) + lp_name_cache_timeout();
318 ret = gencache_set(key, srvname, expiry);
319
320 if (ret)
321 DEBUG(5, ("namecache_status_store: entry %s -> %s\n", key, srvname ));
322 else
323 DEBUG(5, ("namecache_status_store: entry %s store failed.\n", key ));
324
325 SAFE_FREE(key);
326 return ret;
327}
328
329/* Fetch a name status record. */
330
331BOOL namecache_status_fetch(const char *keyname, int keyname_type,
332 int name_type, struct in_addr keyip, char *srvname_out)
333{
334 char *key = NULL;
335 char *value = NULL;
336 time_t timeout;
337
338 if (!gencache_init())
339 return False;
340
341 key = namecache_status_record_key(keyname, keyname_type, name_type, keyip);
342 if (!key)
343 return False;
344
345 if (!gencache_get(key, &value, &timeout)) {
346 DEBUG(5, ("namecache_status_fetch: no entry for %s found.\n", key));
347 SAFE_FREE(key);
348 return False;
349 } else {
350 DEBUG(5, ("namecache_status_fetch: key %s -> %s\n", key, value ));
351 }
352
353 strlcpy(srvname_out, value, 16);
354 SAFE_FREE(key);
355 SAFE_FREE(value);
356 return True;
357}
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