source: trunk/server/source3/libsmb/namecache.c

Last change on this file was 745, checked in by Silvan Scherrer, 13 years ago

Samba Server: updated trunk to 3.6.0
File size: 7.1 KB
RevLine 
[745]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 * Generates a key for netbios name lookups on basis of
30 * netbios name and type.
31 * The caller must free returned key string when finished.
32 *
33 * @param name netbios name string (case insensitive)
34 * @param name_type netbios type of the name being looked up
35 *
36 * @return string consisted of uppercased name and appended
37 * type number
38 */
39
40static char* namecache_key(const char *name,
41 int name_type)
42{
43 char *keystr;
44 asprintf_strupper_m(&keystr, NBTKEY_FMT, name, name_type);
45
46 return keystr;
47}
48
49/**
50 * Store a name(s) in the name cache
51 *
52 * @param name netbios names array
53 * @param name_type integer netbios name type
54 * @param num_names number of names being stored
55 * @param ip_list array of in_addr structures containing
56 * ip addresses being stored
57 **/
58
59bool namecache_store(const char *name,
60 int name_type,
61 int num_names,
62 struct ip_service *ip_list)
63{
64 time_t expiry;
65 char *key, *value_string;
66 int i;
67 bool ret;
68
69 if (name_type > 255) {
70 return False; /* Don't store non-real name types. */
71 }
72
73 if ( DEBUGLEVEL >= 5 ) {
74 TALLOC_CTX *ctx = talloc_stackframe();
75 char *addr = NULL;
76
77 DEBUG(5, ("namecache_store: storing %d address%s for %s#%02x: ",
78 num_names, num_names == 1 ? "": "es", name, name_type));
79
80 for (i = 0; i < num_names; i++) {
81 addr = print_canonical_sockaddr(ctx,
82 &ip_list[i].ss);
83 if (!addr) {
84 continue;
85 }
86 DEBUGADD(5, ("%s%s", addr,
87 (i == (num_names - 1) ? "" : ",")));
88
89 }
90 DEBUGADD(5, ("\n"));
91 TALLOC_FREE(ctx);
92 }
93
94 key = namecache_key(name, name_type);
95 if (!key) {
96 return False;
97 }
98
99 expiry = time(NULL) + lp_name_cache_timeout();
100
101 /*
102 * Generate string representation of ip addresses list
103 * First, store the number of ip addresses and then
104 * place each single ip
105 */
106 if (!ipstr_list_make(&value_string, ip_list, num_names)) {
107 SAFE_FREE(key);
108 SAFE_FREE(value_string);
109 return false;
110 }
111
112 /* set the entry */
113 ret = gencache_set(key, value_string, expiry);
114 SAFE_FREE(key);
115 SAFE_FREE(value_string);
116 return ret;
117}
118
119/**
120 * Look up a name in the cache.
121 *
122 * @param name netbios name to look up for
123 * @param name_type netbios name type of @param name
124 * @param ip_list mallocated list of IP addresses if found in the cache,
125 * NULL otherwise
126 * @param num_names number of entries found
127 *
128 * @return true upon successful fetch or
129 * false if name isn't found in the cache or has expired
130 **/
131
132bool namecache_fetch(const char *name,
133 int name_type,
134 struct ip_service **ip_list,
135 int *num_names)
136{
137 char *key, *value;
138 time_t timeout;
139
140 /* exit now if null pointers were passed as they're required further */
141 if (!ip_list || !num_names) {
142 return False;
143 }
144
145 if (name_type > 255) {
146 return False; /* Don't fetch non-real name types. */
147 }
148
149 *num_names = 0;
150
151 /*
152 * Use gencache interface - lookup the key
153 */
154 key = namecache_key(name, name_type);
155 if (!key) {
156 return False;
157 }
158
159 if (!gencache_get(key, &value, &timeout)) {
160 DEBUG(5, ("no entry for %s#%02X found.\n", name, name_type));
161 SAFE_FREE(key);
162 return False;
163 }
164
165 DEBUG(5, ("name %s#%02X found.\n", name, name_type));
166
167 /*
168 * Split up the stored value into the list of IP adresses
169 */
170 *num_names = ipstr_list_parse(value, ip_list);
171
172 SAFE_FREE(key);
173 SAFE_FREE(value);
174
175 return *num_names > 0; /* true only if some ip has been fetched */
176}
177
178/**
179 * Remove a namecache entry. Needed for site support.
180 *
181 **/
182
183bool namecache_delete(const char *name, int name_type)
184{
185 bool ret;
186 char *key;
187
188 if (name_type > 255) {
189 return False; /* Don't fetch non-real name types. */
190 }
191
192 key = namecache_key(name, name_type);
193 if (!key) {
194 return False;
195 }
196 ret = gencache_del(key);
197 SAFE_FREE(key);
198 return ret;
199}
200
201/**
202 * Delete single namecache entry. Look at the
203 * gencache_iterate definition.
204 *
205 **/
206
207static void flush_netbios_name(const char *key,
208 const char *value,
209 time_t timeout,
210 void *dptr)
211{
212 gencache_del(key);
213 DEBUG(5, ("Deleting entry %s\n", key));
214}
215
216/**
217 * Flush all names from the name cache.
218 * It's done by gencache_iterate()
219 *
220 * @return true upon successful deletion or
221 * false in case of an error
222 **/
223
224void namecache_flush(void)
225{
226 /*
227 * iterate through each NBT cache's entry and flush it
228 * by flush_netbios_name function
229 */
230 gencache_iterate(flush_netbios_name, NULL, "NBT/*");
231 DEBUG(5, ("Namecache flushed\n"));
232}
233
234/* Construct a name status record key. */
235
236static char *namecache_status_record_key(const char *name,
237 int name_type1,
238 int name_type2,
239 const struct sockaddr_storage *keyip)
240{
241 char addr[INET6_ADDRSTRLEN];
242 char *keystr;
243
244 print_sockaddr(addr, sizeof(addr), keyip);
245 asprintf_strupper_m(&keystr, "NBT/%s#%02X.%02X.%s", name,
246 name_type1, name_type2, addr);
247 return keystr;
248}
249
250/* Store a name status record. */
251
252bool namecache_status_store(const char *keyname, int keyname_type,
253 int name_type, const struct sockaddr_storage *keyip,
254 const char *srvname)
255{
256 char *key;
257 time_t expiry;
258 bool ret;
259
260 key = namecache_status_record_key(keyname, keyname_type,
261 name_type, keyip);
262 if (!key)
263 return False;
264
265 expiry = time(NULL) + lp_name_cache_timeout();
266 ret = gencache_set(key, srvname, expiry);
267
268 if (ret) {
269 DEBUG(5, ("namecache_status_store: entry %s -> %s\n",
270 key, srvname ));
271 } else {
272 DEBUG(5, ("namecache_status_store: entry %s store failed.\n",
273 key ));
274 }
275
276 SAFE_FREE(key);
277 return ret;
278}
279
280/* Fetch a name status record. */
281
282bool namecache_status_fetch(const char *keyname,
283 int keyname_type,
284 int name_type,
285 const struct sockaddr_storage *keyip,
286 char *srvname_out)
287{
288 char *key = NULL;
289 char *value = NULL;
290 time_t timeout;
291
292 key = namecache_status_record_key(keyname, keyname_type,
293 name_type, keyip);
294 if (!key)
295 return False;
296
297 if (!gencache_get(key, &value, &timeout)) {
298 DEBUG(5, ("namecache_status_fetch: no entry for %s found.\n",
299 key));
300 SAFE_FREE(key);
301 return False;
302 } else {
303 DEBUG(5, ("namecache_status_fetch: key %s -> %s\n",
304 key, value ));
305 }
306
307 strlcpy(srvname_out, value, 16);
308 SAFE_FREE(key);
309 SAFE_FREE(value);
310 return True;
311}
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