1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26
27 #ifndef _NS_CONNMGMT_H
28 #define _NS_CONNMGMT_H
29
30 #pragma ident "%Z%%M% %I% %E% SMI"
31
32 #ifdef __cplusplus
33 extern "C" {
34 #endif
35
36 #include <thread.h>
37 #include "ns_sldap.h"
38 #include "ns_internal.h"
39 #include "ns_cache_door.h"
40
41 struct ns_conn_user; /* connection user, forward definition */
42 struct ns_conn_mt; /* multi-threaded (MT) connection, forward definition */
43 struct ns_conn_mgmt; /* connection management, forward definition */
44
45 #define NS_CONN_MT_USER_NO_MAX -1
46 #define NS_CONN_MT_USER_MAX NS_CONN_MT_USER_NO_MAX
47 #define NS_LIST_TRY_MAX 3
48
49 /*
50 * Structure for handling the waiter of a pending multi-threaded (MT) connection
51 */
52 typedef struct ns_conn_waiter {
53 cond_t waitcv;
54 uint8_t signaled;
55 struct ns_conn_user *key;
56 struct ns_conn_waiter *next, *prev;
57 } ns_conn_waiter_t;
58
59 /*
60 * type of a connection user
61 */
62 typedef enum {
63 NS_CONN_USER_SEARCH = 1,
64 NS_CONN_USER_WRITE = 2,
65 NS_CONN_USER_AUTH = 3,
66 NS_CONN_USER_GETENT = 4
67 } ns_conn_user_type_t;
68
69 /*
70 * state of a connection user
71 */
72 typedef enum {
73 NS_CONN_USER_UNINITED = 0,
74 NS_CONN_USER_ALLOCATED = 1,
75 NS_CONN_USER_FINDING = 2, /* looking for an MT connection */
76 NS_CONN_USER_WAITING = 3, /* waiting for an MT connection */
77 NS_CONN_USER_WOKEUP = 4,
78 NS_CONN_USER_CONNECT_ERROR = 5,
79 NS_CONN_USER_CONNECTED = 6,
80 NS_CONN_USER_DISCONNECTED = 7,
81 NS_CONN_USER_FREED = 8
82 } ns_conn_user_state_t;
83
84 /*
85 * A connection user represents a request processed by libsldap. It
86 * usually is a thread using the same connection from start to end.
87 * Different connection users of the same type can share the same
88 * connection opened for that type. But search and getent users can
89 * share the same connection opened for either search or getent. AUTH
90 * connection are not shareable.
91 *
92 * A getent user may have a longer lifespan and live outside of libsldap.
93 * This is because the associated search cookie is passed back to the caller
94 * via the firstEntry call and used in the subsequent nextEntry or endEntry
95 * calls. Even though the firstEntry and the nextEntry/endEntry calls may
96 * be running in a different thread, the connection being used will be the
97 * same. It is the one assigend during the firstEntry call.
98 */
99 struct ns_conn_user {
100 ns_conn_user_type_t type; /* search, write, auth, getent, ... */
101 ns_conn_user_state_t state;
102 thread_t tid; /* id of the thread starts the request */
103 struct ns_conn_user *next; /* next conn_user in the linked list */
104 struct ns_conn_mt *conn_mt; /* the MT connection being used */
105 struct ns_conn_mgmt *conn_mgmt; /* ref counted conn management */
106 void *userinfo; /* private data of the request */
107 ns_ldap_return_code ns_rc; /* error return code */
108 ns_ldap_error_t *ns_error; /* error info */
109 boolean_t referral; /* using a referred server ? */
110 boolean_t retry; /* retry the request on certain error? */
111 boolean_t keep_conn; /* keep the conn for reuse ? */
112 boolean_t use_mt_conn; /* using/used an MT connection ? */
113 boolean_t bad_mt_conn; /* MT connection is not usable ? */
114 };
115
116 /*
117 * state of an MT connection
118 */
119 typedef enum {
120 NS_CONN_MT_UNINITED = 0,
121 NS_CONN_MT_CONNECTING = 1,
122 NS_CONN_MT_CONNECT_ERROR = 2,
123 NS_CONN_MT_CONNECTED = 3,
124 NS_CONN_MT_CLOSING = 4
125 } ns_conn_mt_state_t;
126
127 /*
128 * An ns_conn_mt (or MT connection) represents an ldap connection
129 * that can be shared among multiple threads. It also represents
130 * the set of connection users using the ldap connection. It contains
131 * a pointer to the Connection structure that has the physical info
132 * of the connection (server name, address, ldap handle, etc). It
133 * also contains a linked list of all the conn_user using the ldap
134 * connection. The connection users can wait on an MT connection
135 * to become available or be told to abort and clean up when one of
136 * the connection user detects an error and knows that the connection
137 * is no longer usable. The error info is then saved in the structure
138 * for other users to consume.
139 *
140 * An MT connection is meant to be shared concurrently and persistent.
141 * Even when there's no current user, it will be kept by the connection
142 * management, waiting for the next user. It will be closed when
143 * a connection error is detected, when a better server should be
144 * used, when the Native LDAP configuration change, or when the libsldap
145 * is being unloaded.
146 */
147 typedef struct ns_conn_mt {
148 mutex_t lock;
149 ns_conn_mt_state_t state;
150 pid_t pid; /* process creates the connection */
151 thread_t tid; /* thread creates the connection */
152 struct ns_conn_mt *next; /* next conn_mt in the linked list */
153 ns_conn_user_t *cu_head; /* head of conn_user linked list */
154 ns_conn_user_t *cu_tail; /* tail of conn_user linked list */
155 struct ns_conn_mgmt *conn_mgmt; /* ref counted conn management */
156 ns_conn_waiter_t waiter; /* first of the connection waiters */
157 uint_t cu_cnt; /* number of the using conn_user */
158 int32_t cu_max; /* max. allowed number of conn_user */
159 uint_t waiter_cnt; /* number of waiters */
160 ns_conn_user_type_t opened_for; /* type of conn_user opened for */
161 Connection *conn; /* name, IP address, ldap handle, etc */
162 time_t create_time; /* time when connection created */
163 time_t access_time; /* time when last used */
164 ns_ldap_return_code ns_rc; /* saved error code */
165 ns_ldap_error_t *ns_error; /* saved error info */
166 boolean_t close_when_nouser; /* close connection when */
167 /* last user is done ? */
168 boolean_t detached; /* no longer in connection pool? */
169 boolean_t referral; /* using a referred server ? */
170 } ns_conn_mt_t;
171
172 /*
173 * state of a connection management
174 * (a connection pool sharing the same native LDAP configuration)
175 */
176 typedef enum {
177 NS_CONN_MGMT_UNINITED = 0,
178 NS_CONN_MGMT_INACTIVE = 1, /* conn sharing not yet requested */
179 NS_CONN_MGMT_ACTIVE = 2, /* connection sharing required/requested */
180 NS_CONN_MGMT_DETACHED = 3 /* on the way down, no new user allowed */
181 } ns_conn_mgmt_state_t;
182
183 /*
184 * An ns_conn_mgmt (or connection management) represents the set of MT
185 * connections using the same native LDAP configuration. It is a connection
186 * pool that can adjust the MT connection status and usage based on the
187 * change notifications it receives from the ldap_cachemgr daemon, OR When
188 * the change is detected at config refresh time. When a server status
189 * change (up or down) notification is received or detected, it will
190 * close the MT connections using the server. Or mark them as to-be-closed
191 * and close them when all users are done using them. When a config change
192 * notice is received, it will detach itself and allow a new ns_conn_mgmt be
193 * created for the new configuration. The old config would still be used
194 * by the detached ns_conn_mgmt. Both will be destroyed when all existing
195 * conn_user are done. Any conn_user and MT connection created after the
196 * configuration switch will use the new configuration.
197 *
198 * Note that there's always just one current ns_conn_mgmt. Its usage is
199 * reference counted. Any new conn_user or MT connection referencing
200 * the ns_conn_mgmt adds 1 to the count, any release of the ns_conn_mgmt
201 * decrement the count by 1. The ns_conn_mgmt can not be freed until
202 * the reference count becomes zero.
203 *
204 * Each ns_conn_mgmt references a native LDAP configuration. The config
205 * component of this library always maintains a global configuration. It is
206 * referred to as the current global config. The current ns_conn_mgmt
207 * uses that global config. When an ns_conn_mgmt is detached, or not
208 * longer active/current, the config it uses is no longer the current global
209 * one, which is referred as the per connection management config. When
210 * the ns_conn_mgmt is freed, the config will also be destroyed.
211 */
212
213 typedef struct ns_conn_mgmt {
214 mutex_t lock;
215 ns_conn_mgmt_state_t state;
216 pid_t pid; /* process creates the conn_mgmt */
217 thread_t procchg_tid; /* id of the change monitor thread */
218 ns_conn_mt_t *cm_head; /* head of the conn_mt linked list */
219 ns_conn_mt_t *cm_tail; /* tail of the conn_mt linked list */
220 mutex_t cfg_lock; /* lock serializes access to config */
221 ldap_get_chg_cookie_t cfg_cookie; /* used to detect if config changes */
222 ns_config_t *config; /* the native LDAP config being used */
223 char **pservers; /* preferred servers defined in config */
224 uint_t cm_cnt; /* number of MT connection in the pool */
225 uint_t ref_cnt; /* number of reference by conn_MT/conn_user */
226 boolean_t is_nscd; /* running in a nscd ? */
227 boolean_t is_peruser_nscd; /* running in a per-user nscd ? */
228 boolean_t ldap_mt; /* libldap supports multi-threaded client ? */
229 boolean_t do_mt_conn; /* need and able to do MT conn ? */
230 boolean_t shutting_down; /* on the way down ? */
231 boolean_t cfg_reloaded; /* config is not current ? */
232 boolean_t procchg_started; /* change monitor thread started ? */
233 boolean_t procchg_door_call; /* in door call and waiting ? */
234 boolean_t pservers_loaded; /* pservers array is set ? */
235 } ns_conn_mgmt_t;
236
237 /*
238 * For a connection management and the conn_mt connections it manages, it is
239 * very helpful to know exactly when the Native LDAP configuration changes
240 * and when the status of the configured servers change. If the config
241 * changes, new connection management will be created. If servers go up
242 * or down, conn_mt connections being used need to be dropped or switched.
243 * For processes other than the main nscd, the changes has to be detected
244 * in a less efficient way by libsldap. For the main nscd (not including
245 * peruser nscd), the connection management which has active conn_mt
246 * connections can rely on the ldap_cachemgr daemon to report if there's any
247 * change in servers' status or if the native LDAP configuration has changed.
248 *
249 * The mechanism for reporting of the changes is a door call sent from
250 * libsldap to ldap_cachemgr. The call will not be returned until changes
251 * detected by ldap_cachemgr. When the change info is passed back to
252 * libsldap, the change monitor thread will wake up from the door call
253 * and process the notification. For servers went from up to down, the
254 * associated MT connections will be closed, and then all conn_users'
255 * state will be marked as closing. When a conn_user notices it, the
256 * operations represented by that conn_user will be ended with error
257 * info. When a more preferred server is up, MT connections using
258 * less preferred servers will be marked as closed-when-all-user-done,
259 * so that new connection will be opened and using the preferred server.
260 * A configuration change causes the current connection management and
261 * the configuration it uses to become detached but continually being
262 * used by the old MT connections. Any new MT connection opened will
263 * be put in a new connection management and uses the new configuration
264 * immediately.
265 */
266 typedef enum {
267 NS_SERVER_UP = 1,
268 NS_SERVER_DOWN = 2
269 } ns_server_status_t;
270
271 typedef struct ns_server_status_change {
272 int num_server;
273 boolean_t config_changed;
274 ns_server_status_t *changes; /* array of status change */
275 char **servers; /* array of server */
276 } ns_server_status_change_t;
277
278 /*
279 * connection management functions
280 */
281 ns_conn_mgmt_t *__s_api_conn_mgmt_init();
282 int __s_api_setup_mt_ld(LDAP *ld);
283 int __s_api_check_mtckey();
284 void __s_api_use_prev_conn_mgmt(int, ns_config_t *);
285 ns_conn_user_t *__s_api_conn_user_init(int, void *, boolean_t);
286 void __s_api_conn_mt_return(ns_conn_user_t *);
287 void __s_api_conn_user_free(ns_conn_user_t *);
288 int __s_api_conn_mt_add(Connection *con, ns_conn_user_t *, ns_ldap_error_t **);
289 int __s_api_conn_mt_get(const char *, const int, const ns_cred_t *,
290 Connection **, ns_ldap_error_t **, ns_conn_user_t *);
291 void __s_api_conn_mt_remove(ns_conn_user_t *, int, ns_ldap_error_t **);
292 int __s_api_check_libldap_MT_conn_support(ns_conn_user_t *, LDAP *ld,
293 ns_ldap_error_t **);
294 void __s_api_conn_mt_close(ns_conn_user_t *, int, ns_ldap_error_t **);
295 void __s_api_reinit_conn_mgmt_new_config(ns_config_t *);
296 int __s_api_setup_retry_search(ns_conn_user_t **, ns_conn_user_type_t, int *,
297 int *, ns_ldap_error_t **);
298 int __s_api_setup_getnext(ns_conn_user_t *, int *, ns_ldap_error_t **);
299 void __s_api_shutdown_conn_mgmt();
300
301 #ifdef __cplusplus
302 }
303 #endif
304
305 #endif /* _NS_CONNMGMT_H */