2
Unix SMB/CIFS implementation.
4
Winbind daemon connection manager
6
Copyright (C) Tim Potter 2001
7
Copyright (C) Andrew Bartlett 2002
8
Copyright (C) Gerald (Jerry) Carter 2003
9
Copyright (C) Marc VanHeyningen 2008
11
This program is free software; you can redistribute it and/or modify
12
it under the terms of the GNU General Public License as published by
13
the Free Software Foundation; either version 3 of the License, or
14
(at your option) any later version.
16
This program is distributed in the hope that it will be useful,
17
but WITHOUT ANY WARRANTY; without even the implied warranty of
18
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19
GNU General Public License for more details.
21
You should have received a copy of the GNU General Public License
22
along with this program. If not, see <http://www.gnu.org/licenses/>.
30
* Negative connection cache implemented in terms of gencache API
32
* The negative connection cache stores names of servers which have
33
* been unresponsive so that we don't waste time repeatedly trying
34
* to contact them. It used to use an in-memory linked list, but
35
* this limited its utility to a single process
40
* prefix used for all entries put into the general cache
42
static const char NEGATIVE_CONN_CACHE_PREFIX[] = "NEG_CONN_CACHE";
45
* Marshalls the domain and server name into the key for the gencache
48
* @param[in] domain required
49
* @param[in] server may be a FQDN or an IP address
50
* @return the resulting string, which the caller is responsible for
52
* @retval NULL returned on error
54
static char *negative_conn_cache_keystr(const char *domain, const char *server)
56
const char NEGATIVE_CONN_CACHE_KEY_FMT[] = "%s/%s,%s";
59
SMB_ASSERT(domain != NULL);
63
keystr = talloc_asprintf(talloc_tos(),NEGATIVE_CONN_CACHE_KEY_FMT,
64
NEGATIVE_CONN_CACHE_PREFIX, domain, server);
66
DEBUG(0, ("negative_conn_cache_keystr: malloc error\n"));
73
* Marshalls the NT status into a printable value field for the gencache
77
* @return the resulting string, which the caller is responsible for
79
* @retval NULL returned on error
81
static char *negative_conn_cache_valuestr(NTSTATUS status)
83
char *valuestr = NULL;
85
valuestr = talloc_asprintf(talloc_tos(), "%x", NT_STATUS_V(status));
86
if (valuestr == NULL) {
87
DEBUG(0, ("negative_conn_cache_valuestr: malloc error\n"));
94
* Un-marshalls the NT status from a printable field for the gencache
97
* @param[in] value The value field from the record
98
* @return the decoded NT status
99
* @retval NT_STATUS_OK returned on error
101
static NTSTATUS negative_conn_cache_valuedecode(const char *value)
103
NTSTATUS result = NT_STATUS_OK;
105
SMB_ASSERT(value != NULL);
106
if (sscanf(value, "%x", &(NT_STATUS_V(result))) != 1)
107
DEBUG(0, ("negative_conn_cache_valuestr: unable to parse "
108
"value field '%s'\n", value));
113
* Function passed to gencache_iterate to remove any matching items
116
* @param[in] key Key to the record found and to be deleted
117
* @param[in] value Value to the record (ignored)
118
* @param[in] timeout Timeout remaining for the record (ignored)
119
* @param[in] dptr Handle for passing additional data (ignored)
121
static void delete_matches(const char *key, const char *value,
122
time_t timeout, void *dptr)
129
* Checks for a given domain/server record in the negative cache
132
* @param[in] server may be either a FQDN or an IP address
133
* @return The cached failure status
134
* @retval NT_STATUS_OK returned if no record is found or an error occurs
136
NTSTATUS check_negative_conn_cache( const char *domain, const char *server)
138
NTSTATUS result = NT_STATUS_OK;
142
key = negative_conn_cache_keystr(domain, server);
146
if (gencache_get(key, &value, (time_t *) NULL))
147
result = negative_conn_cache_valuedecode(value);
149
DEBUG(9,("check_negative_conn_cache returning result %d for domain %s "
150
"server %s\n", NT_STATUS_V(result), domain, server));
157
* Delete any negative cache entry for the given domain/server
160
* @param[in] server may be either a FQDN or an IP address
162
void delete_negative_conn_cache(const char *domain, const char *server)
166
key = negative_conn_cache_keystr(domain, server);
171
DEBUG(9,("delete_negative_conn_cache removing domain %s server %s\n",
180
* Add an entry to the failed connection cache
183
* @param[in] server may be a FQDN or an IP addr in printable form
184
* @param[in] result error to cache; must not be NT_STATUS_OK
186
void add_failed_connection_entry(const char *domain, const char *server,
192
SMB_ASSERT(!NT_STATUS_IS_OK(result));
194
key = negative_conn_cache_keystr(domain, server);
196
DEBUG(0, ("add_failed_connection_entry: key creation error\n"));
200
value = negative_conn_cache_valuestr(result);
202
DEBUG(0, ("add_failed_connection_entry: value creation error\n"));
206
if (gencache_set(key, value,
207
time((time_t *) NULL)
208
+ FAILED_CONNECTION_CACHE_TIMEOUT))
209
DEBUG(9,("add_failed_connection_entry: added domain %s (%s) "
210
"to failed conn cache\n", domain, server ));
212
DEBUG(1,("add_failed_connection_entry: failed to add "
213
"domain %s (%s) to failed conn cache\n",
223
* Deletes all records from the negative connection cache in all domains
225
void flush_negative_conn_cache( void )
227
flush_negative_conn_cache_for_domain("*");
232
* Deletes all records for a specified domain from the negative connection
235
* @param[in] domain String to match against domain portion of keys, or "*"
236
* to match all domains
238
void flush_negative_conn_cache_for_domain(const char *domain)
240
char *key_pattern = NULL;
242
key_pattern = negative_conn_cache_keystr(domain,"*");
243
if (key_pattern == NULL) {
244
DEBUG(0, ("flush_negative_conn_cache_for_domain: "
245
"key creation error\n"));
249
gencache_iterate(delete_matches, (void *) NULL, key_pattern);
250
DEBUG(8, ("flush_negative_conn_cache_for_domain: flushed domain %s\n",
254
TALLOC_FREE(key_pattern);