s3:libsmb: s/struct event_context/struct tevent_context
[Samba/gebeck_regimport.git] / source3 / libsmb / conncache.c
blob66353188d2b3fa8f36b8727cfbcd3d38cc841527
1 /*
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
10 Copyright (C) Volker Lendecke 2009
12 This program is free software; you can redistribute it and/or modify
13 it under the terms of the GNU General Public License as published by
14 the Free Software Foundation; either version 3 of the License, or
15 (at your option) any later version.
17 This program is distributed in the hope that it will be useful,
18 but WITHOUT ANY WARRANTY; without even the implied warranty of
19 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 GNU General Public License for more details.
22 You should have received a copy of the GNU General Public License
23 along with this program. If not, see <http://www.gnu.org/licenses/>.
27 #include "includes.h"
29 /**
30 * @file
31 * Negative connection cache implemented in terms of gencache API
33 * The negative connection cache stores names of servers which have
34 * been unresponsive so that we don't waste time repeatedly trying
35 * to contact them. It used to use an in-memory linked list, but
36 * this limited its utility to a single process
40 /**
41 * Marshalls the domain and server name into the key for the gencache
42 * record
44 * @param[in] domain required
45 * @param[in] server may be a FQDN or an IP address
46 * @return the resulting string, which the caller is responsible for
47 * SAFE_FREE()ing
48 * @retval NULL returned on error
50 static char *negative_conn_cache_keystr(const char *domain, const char *server)
52 char *keystr = NULL;
54 if (domain == NULL) {
55 return NULL;
57 if (server == NULL)
58 server = "";
60 keystr = talloc_asprintf(talloc_tos(), "NEG_CONN_CACHE/%s,%s",
61 domain, server);
62 if (keystr == NULL) {
63 DEBUG(0, ("negative_conn_cache_keystr: malloc error\n"));
66 return keystr;
69 /**
70 * Marshalls the NT status into a printable value field for the gencache
71 * record
73 * @param[in] status
74 * @return the resulting string, which the caller is responsible for
75 * SAFE_FREE()ing
76 * @retval NULL returned on error
78 static char *negative_conn_cache_valuestr(NTSTATUS status)
80 char *valuestr = NULL;
82 valuestr = talloc_asprintf(talloc_tos(), "%x", NT_STATUS_V(status));
83 if (valuestr == NULL) {
84 DEBUG(0, ("negative_conn_cache_valuestr: malloc error\n"));
87 return valuestr;
90 /**
91 * Un-marshalls the NT status from a printable field for the gencache
92 * record
94 * @param[in] value The value field from the record
95 * @return the decoded NT status
96 * @retval NT_STATUS_OK returned on error
98 static NTSTATUS negative_conn_cache_valuedecode(const char *value)
100 unsigned int v = NT_STATUS_V(NT_STATUS_INTERNAL_ERROR);
102 if (value == NULL) {
103 return NT_STATUS_INTERNAL_ERROR;
105 if (sscanf(value, "%x", &v) != 1) {
106 DEBUG(0, ("negative_conn_cache_valuedecode: unable to parse "
107 "value field '%s'\n", value));
109 return NT_STATUS(v);
113 * Function passed to gencache_iterate to remove any matching items
114 * from the list
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)
124 gencache_del(key);
129 * Checks for a given domain/server record in the negative cache
131 * @param[in] domain
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;
139 char *key = NULL;
140 char *value = NULL;
142 key = negative_conn_cache_keystr(domain, server);
143 if (key == NULL)
144 goto done;
146 if (gencache_get(key, &value, NULL))
147 result = negative_conn_cache_valuedecode(value);
148 done:
149 DEBUG(9,("check_negative_conn_cache returning result %d for domain %s "
150 "server %s\n", NT_STATUS_V(result), domain, server));
151 TALLOC_FREE(key);
152 SAFE_FREE(value);
153 return result;
157 * Add an entry to the failed connection cache
159 * @param[in] domain
160 * @param[in] server may be a FQDN or an IP addr in printable form
161 * @param[in] result error to cache; must not be NT_STATUS_OK
163 void add_failed_connection_entry(const char *domain, const char *server,
164 NTSTATUS result)
166 char *key = NULL;
167 char *value = NULL;
169 if (NT_STATUS_IS_OK(result)) {
170 /* Nothing failed here */
171 return;
174 key = negative_conn_cache_keystr(domain, server);
175 if (key == NULL) {
176 DEBUG(0, ("add_failed_connection_entry: key creation error\n"));
177 goto done;
180 value = negative_conn_cache_valuestr(result);
181 if (value == NULL) {
182 DEBUG(0, ("add_failed_connection_entry: value creation error\n"));
183 goto done;
186 if (gencache_set(key, value,
187 time(NULL) + FAILED_CONNECTION_CACHE_TIMEOUT))
188 DEBUG(9,("add_failed_connection_entry: added domain %s (%s) "
189 "to failed conn cache\n", domain, server ));
190 else
191 DEBUG(1,("add_failed_connection_entry: failed to add "
192 "domain %s (%s) to failed conn cache\n",
193 domain, server));
195 done:
196 TALLOC_FREE(key);
197 TALLOC_FREE(value);
198 return;
202 * Deletes all records for a specified domain from the negative connection
203 * cache
205 * @param[in] domain String to match against domain portion of keys, or "*"
206 * to match all domains
208 void flush_negative_conn_cache_for_domain(const char *domain)
210 char *key_pattern = NULL;
212 key_pattern = negative_conn_cache_keystr(domain,"*");
213 if (key_pattern == NULL) {
214 DEBUG(0, ("flush_negative_conn_cache_for_domain: "
215 "key creation error\n"));
216 goto done;
219 gencache_iterate(delete_matches, NULL, key_pattern);
220 DEBUG(8, ("flush_negative_conn_cache_for_domain: flushed domain %s\n",
221 domain));
223 done:
224 TALLOC_FREE(key_pattern);
225 return;