1e1dd0a2th/*
2e1dd0a2th * CDDL HEADER START
3e1dd0a2th *
4e1dd0a2th * The contents of this file are subject to the terms of the
5e1dd0a2th * Common Development and Distribution License (the "License").
6e1dd0a2th * You may not use this file except in compliance with the License.
7e1dd0a2th *
8e1dd0a2th * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9e1dd0a2th * or http://www.opensolaris.org/os/licensing.
10e1dd0a2th * See the License for the specific language governing permissions
11e1dd0a2th * and limitations under the License.
12e1dd0a2th *
13e1dd0a2th * When distributing Covered Code, include this CDDL HEADER in each
14e1dd0a2th * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15e1dd0a2th * If applicable, add the following below this CDDL HEADER, with the
16e1dd0a2th * fields enclosed by brackets "[]" replaced with your own identifying
17e1dd0a2th * information: Portions Copyright [yyyy] [name of copyright owner]
18e1dd0a2th *
19e1dd0a2th * CDDL HEADER END
20e1dd0a2th */
21e1dd0a2th/*
22e1dd0a2th * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23e1dd0a2th * Use is subject to license terms.
24695ef82Gordon Ross *
25695ef82Gordon Ross * Copyright 2017 Nexenta Systems, Inc.  All rights reserved.
26e1dd0a2th */
27e1dd0a2th
28e1dd0a2th#ifndef	_NS_CONNMGMT_H
29e1dd0a2th#define	_NS_CONNMGMT_H
30e1dd0a2th
31e1dd0a2th#ifdef __cplusplus
32e1dd0a2thextern "C" {
33e1dd0a2th#endif
34e1dd0a2th
35e1dd0a2th#include <thread.h>
36e1dd0a2th#include "ns_sldap.h"
37e1dd0a2th#include "ns_internal.h"
38e1dd0a2th#include "ns_cache_door.h"
39e1dd0a2th
40e1dd0a2thstruct ns_conn_user; /* connection user, forward definition */
41e1dd0a2thstruct ns_conn_mt;   /* multi-threaded (MT) connection, forward definition */
42e1dd0a2thstruct ns_conn_mgmt; /* connection management, forward definition */
43e1dd0a2th
44e1dd0a2th#define	NS_CONN_MT_USER_NO_MAX	-1
45e1dd0a2th#define	NS_CONN_MT_USER_MAX	NS_CONN_MT_USER_NO_MAX
46e1dd0a2th#define	NS_LIST_TRY_MAX		3
47e1dd0a2th
48e1dd0a2th/*
49e1dd0a2th * Structure for handling the waiter of a pending multi-threaded (MT) connection
50e1dd0a2th */
51e1dd0a2thtypedef struct ns_conn_waiter {
52e1dd0a2th	cond_t			waitcv;
53e1dd0a2th	uint8_t			signaled;
54e1dd0a2th	struct ns_conn_user	*key;
55e1dd0a2th	struct ns_conn_waiter	*next, *prev;
56e1dd0a2th} ns_conn_waiter_t;
57e1dd0a2th
58e1dd0a2th/*
59e1dd0a2th * type of a connection user
60e1dd0a2th */
61e1dd0a2thtypedef enum {
62e1dd0a2th	NS_CONN_USER_SEARCH	= 1,
63e1dd0a2th	NS_CONN_USER_WRITE	= 2,
64e1dd0a2th	NS_CONN_USER_AUTH	= 3,
65e1dd0a2th	NS_CONN_USER_GETENT	= 4
66e1dd0a2th} ns_conn_user_type_t;
67e1dd0a2th
68e1dd0a2th/*
69e1dd0a2th * state of a connection user
70e1dd0a2th */
71e1dd0a2thtypedef enum {
72e1dd0a2th	NS_CONN_USER_UNINITED		= 0,
73e1dd0a2th	NS_CONN_USER_ALLOCATED		= 1,
74e1dd0a2th	NS_CONN_USER_FINDING		= 2, /* looking for an MT connection */
75e1dd0a2th	NS_CONN_USER_WAITING		= 3, /* waiting for an MT connection */
76e1dd0a2th	NS_CONN_USER_WOKEUP		= 4,
77e1dd0a2th	NS_CONN_USER_CONNECT_ERROR	= 5,
78e1dd0a2th	NS_CONN_USER_CONNECTED  	= 6,
79e1dd0a2th	NS_CONN_USER_DISCONNECTED	= 7,
80e1dd0a2th	NS_CONN_USER_FREED		= 8
81e1dd0a2th} ns_conn_user_state_t;
82e1dd0a2th
83e1dd0a2th/*
84e1dd0a2th * A connection user represents a request processed by libsldap. It
85e1dd0a2th * usually is a thread using the same connection from start to end.
86e1dd0a2th * Different connection users of the same type can share the same
87e1dd0a2th * connection opened for that type. But search and getent users can
88e1dd0a2th * share the same connection opened for either search or getent. AUTH
89e1dd0a2th * connection are not shareable.
90e1dd0a2th *
91e1dd0a2th * A getent user may have a longer lifespan and live outside of libsldap.
92e1dd0a2th * This is because the associated search cookie is passed back to the caller
93e1dd0a2th * via the firstEntry call and used in the subsequent nextEntry or endEntry
94e1dd0a2th * calls. Even though the firstEntry and the nextEntry/endEntry calls may
95e1dd0a2th * be running in a different thread, the connection being used will be the
96e1dd0a2th * same. It is the one assigend during the firstEntry call.
97e1dd0a2th */
98e1dd0a2thstruct ns_conn_user {
99e1dd0a2th	ns_conn_user_type_t	type; /* search, write, auth, getent, ... */
100e1dd0a2th	ns_conn_user_state_t	state;
101e1dd0a2th	thread_t		tid;   /* id of the thread starts the request */
102e1dd0a2th	struct ns_conn_user	*next; /* next conn_user in the linked list */
103e1dd0a2th	struct ns_conn_mt	*conn_mt; /* the MT connection being used */
104e1dd0a2th	struct ns_conn_mgmt	*conn_mgmt; /* ref counted conn management */
105e1dd0a2th	void			*userinfo; /* private data of the request */
106e1dd0a2th	ns_ldap_return_code	ns_rc; /* error return code */
107e1dd0a2th	ns_ldap_error_t		*ns_error; /* error info */
108e1dd0a2th	boolean_t		referral; /* using a referred server ? */
109e1dd0a2th	boolean_t		retry; /* retry the request on certain error? */
110e1dd0a2th	boolean_t		keep_conn; /* keep the conn for reuse ? */
111e1dd0a2th	boolean_t		use_mt_conn; /* using/used an MT connection ? */
112e1dd0a2th	boolean_t		bad_mt_conn; /* MT connection is not usable ? */
113e1dd0a2th};
114e1dd0a2th
115e1dd0a2th/*
116e1dd0a2th * state of an MT connection
117e1dd0a2th */
118e1dd0a2thtypedef enum {
119e1dd0a2th	NS_CONN_MT_UNINITED		= 0,
120e1dd0a2th	NS_CONN_MT_CONNECTING		= 1,
121e1dd0a2th	NS_CONN_MT_CONNECT_ERROR	= 2,
122e1dd0a2th	NS_CONN_MT_CONNECTED		= 3,
123e1dd0a2th	NS_CONN_MT_CLOSING		= 4
124e1dd0a2th} ns_conn_mt_state_t;
125e1dd0a2th
126e1dd0a2th/*
127e1dd0a2th * An ns_conn_mt (or MT connection) represents an ldap connection
128e1dd0a2th * that can be shared among multiple threads. It also represents
129e1dd0a2th * the set of connection users using the ldap connection. It contains
130e1dd0a2th * a pointer to the Connection structure that has the physical info
131e1dd0a2th * of the connection (server name, address, ldap handle, etc). It
132e1dd0a2th * also contains a linked list of all the conn_user using the ldap
133e1dd0a2th * connection. The connection users can wait on an MT connection
134e1dd0a2th * to become available or be told to abort and clean up when one of
135e1dd0a2th * the connection user detects an error and knows that the connection
136e1dd0a2th * is no longer usable. The error info is then saved in the structure
137e1dd0a2th * for other users to consume.
138e1dd0a2th *
139e1dd0a2th * An MT connection is meant to be shared concurrently and persistent.
140e1dd0a2th * Even when there's no current user, it will be kept by the connection
141e1dd0a2th * management, waiting for the next user. It will be closed when
142e1dd0a2th * a connection error is detected, when a better server should be
143e1dd0a2th * used, when the Native LDAP configuration change, or when the libsldap
144e1dd0a2th * is being unloaded.
145e1dd0a2th */
146e1dd0a2thtypedef struct ns_conn_mt {
147e1dd0a2th	mutex_t			lock;
148e1dd0a2th	ns_conn_mt_state_t	state;
149e1dd0a2th	pid_t			pid; /* process creates the connection */
150e1dd0a2th	thread_t		tid; /* thread creates the connection */
151e1dd0a2th	struct ns_conn_mt	*next; /* next conn_mt in the linked list */
152e1dd0a2th	ns_conn_user_t		*cu_head; /* head of conn_user linked list */
153e1dd0a2th	ns_conn_user_t		*cu_tail; /* tail of conn_user linked list */
154e1dd0a2th	struct ns_conn_mgmt	*conn_mgmt; /* ref counted conn management */
155e1dd0a2th	ns_conn_waiter_t	waiter; /* first of the connection waiters */
156e1dd0a2th	uint_t			cu_cnt; /* number of the using conn_user */
157e1dd0a2th	int32_t			cu_max; /* max. allowed number of conn_user */
158e1dd0a2th	uint_t			waiter_cnt; /* number of waiters */
159e1dd0a2th	ns_conn_user_type_t	opened_for; /* type of conn_user opened for */
160e1dd0a2th	Connection		*conn; /* name, IP address, ldap handle, etc */
161e1dd0a2th	time_t			create_time; /* time when connection created */
162e1dd0a2th	time_t			access_time; /* time when last used */
163e1dd0a2th	ns_ldap_return_code	ns_rc; /* saved error code */
164e1dd0a2th	ns_ldap_error_t		*ns_error; /* saved error info */
165e1dd0a2th	boolean_t		close_when_nouser;  /* close connection when */
166e1dd0a2th						    /* last user is done ? */
167e1dd0a2th	boolean_t		detached; /* no longer in connection pool? */
168e1dd0a2th	boolean_t		referral; /* using a referred server ? */
169e1dd0a2th} ns_conn_mt_t;
170e1dd0a2th
171e1dd0a2th/*
172e1dd0a2th * state of a connection management
173e1dd0a2th * (a connection pool sharing the same native LDAP configuration)
174e1dd0a2th */
175e1dd0a2thtypedef enum {
176e1dd0a2th	NS_CONN_MGMT_UNINITED	= 0,
177e1dd0a2th	NS_CONN_MGMT_INACTIVE	= 1, /* conn sharing not yet requested */
178e1dd0a2th	NS_CONN_MGMT_ACTIVE	= 2, /* connection sharing required/requested */
179e1dd0a2th	NS_CONN_MGMT_DETACHED	= 3  /* on the way down, no new user allowed */
180e1dd0a2th} ns_conn_mgmt_state_t;
181e1dd0a2th
182e1dd0a2th/*
183e1dd0a2th * An ns_conn_mgmt (or connection management) represents the set of MT
184e1dd0a2th * connections using the same native LDAP configuration. It is a connection
185e1dd0a2th * pool that can adjust the MT connection status and usage based on the
186e1dd0a2th * change notifications it receives from the ldap_cachemgr daemon, OR When
187e1dd0a2th * the change is detected at config refresh time. When a server status
188e1dd0a2th * change (up or down) notification is received or detected, it will
189e1dd0a2th * close the MT connections using the server. Or mark them as to-be-closed
190e1dd0a2th * and close them when all users are done using them. When a config change
191e1dd0a2th * notice is received, it will detach itself and allow a new ns_conn_mgmt be
192e1dd0a2th * created for the new configuration. The old config would still be used
193e1dd0a2th * by the detached ns_conn_mgmt. Both will be destroyed when all existing
194e1dd0a2th * conn_user are done. Any conn_user and MT connection created after the
195e1dd0a2th * configuration switch will use the new configuration.
196e1dd0a2th *
197e1dd0a2th * Note that there's always just one current ns_conn_mgmt. Its usage is
198e1dd0a2th * reference counted. Any new conn_user or MT connection referencing
199e1dd0a2th * the ns_conn_mgmt adds 1 to the count, any release of the ns_conn_mgmt
200e1dd0a2th * decrement the count by 1. The ns_conn_mgmt can not be freed until
201e1dd0a2th * the reference count becomes zero.
202e1dd0a2th *
203e1dd0a2th * Each ns_conn_mgmt references a native LDAP configuration. The config
204e1dd0a2th * component of this library always maintains a global configuration. It is
205e1dd0a2th * referred to as the current global config. The current ns_conn_mgmt
206e1dd0a2th * uses that global config. When an ns_conn_mgmt is detached, or not
207e1dd0a2th * longer active/current, the config it uses is no longer the current global
208e1dd0a2th * one, which is referred as the per connection management config. When
209e1dd0a2th * the ns_conn_mgmt is freed, the config will also be destroyed.
210e1dd0a2th */
211e1dd0a2th
212e1dd0a2thtypedef struct ns_conn_mgmt {
213e1dd0a2th	mutex_t		lock;
214e1dd0a2th	ns_conn_mgmt_state_t state;
215e1dd0a2th	pid_t		pid; /* process creates the conn_mgmt */
216e1dd0a2th	thread_t	procchg_tid; /* id of the change monitor thread */
217e1dd0a2th	ns_conn_mt_t	*cm_head; /* head of the conn_mt linked list */
218e1dd0a2th	ns_conn_mt_t	*cm_tail; /* tail of the conn_mt linked list */
219e1dd0a2th	mutex_t		cfg_lock; /* lock serializes access to config */
220e1dd0a2th	ldap_get_chg_cookie_t cfg_cookie; /* used to detect if config changes */
221e1dd0a2th	ns_config_t	*config; /* the native LDAP config being used */
222e1dd0a2th	char		**pservers; /* preferred servers defined in config */
223e1dd0a2th	uint_t		cm_cnt;  /* number of MT connection in the pool */
224e1dd0a2th	uint_t		ref_cnt; /* number of reference by conn_MT/conn_user */
225e1dd0a2th	boolean_t	is_nscd; /* running in a nscd ? */
226e1dd0a2th	boolean_t	is_peruser_nscd; /* running in a per-user nscd ? */
227e1dd0a2th	boolean_t	ldap_mt; /* libldap supports multi-threaded client ? */
228e1dd0a2th	boolean_t	do_mt_conn;	/* need and able to do MT conn ? */
229e1dd0a2th	boolean_t	shutting_down;  /* on the way down ? */
230e1dd0a2th	boolean_t	cfg_reloaded;   /* config is not current ? */
231e1dd0a2th	boolean_t	procchg_started; /* change monitor thread started ? */
232e1dd0a2th	boolean_t	procchg_door_call; /* in door call and waiting ? */
233e1dd0a2th	boolean_t	pservers_loaded; /* pservers array is set ? */
234e1dd0a2th} ns_conn_mgmt_t;
235e1dd0a2th
236e1dd0a2th/*
237e1dd0a2th * For a connection management and the conn_mt connections it manages, it is
238e1dd0a2th * very helpful to know exactly when the Native LDAP configuration changes
239e1dd0a2th * and when the status of the configured servers change. If the config
240e1dd0a2th * changes, new connection management will be created. If servers go up
241e1dd0a2th * or down, conn_mt connections being used need to be dropped or switched.
242e1dd0a2th * For processes other than the main nscd, the changes has to be detected
243e1dd0a2th * in a less efficient way by libsldap. For the main nscd (not including
244e1dd0a2th * peruser nscd), the connection management which has active conn_mt
245e1dd0a2th * connections can rely on the ldap_cachemgr daemon to report if there's any
246e1dd0a2th * change in servers' status or if the native LDAP configuration has changed.
247e1dd0a2th *
248e1dd0a2th * The mechanism for reporting of the changes is a door call sent from
249e1dd0a2th * libsldap to ldap_cachemgr. The call will not be returned until changes
250e1dd0a2th * detected by ldap_cachemgr. When the change info is passed back to
251e1dd0a2th * libsldap, the change monitor thread will wake up from the door call
252e1dd0a2th * and process the notification. For servers went from up to down, the
253e1dd0a2th * associated MT connections will be closed, and then all conn_users'
254e1dd0a2th * state will be marked as closing. When a conn_user notices it, the
255e1dd0a2th * operations represented by that conn_user will be ended with error
256e1dd0a2th * info. When a more preferred server is up, MT connections using
257e1dd0a2th * less preferred servers will be marked as closed-when-all-user-done,
258e1dd0a2th * so that new connection will be opened and using the preferred server.
259e1dd0a2th * A configuration change causes the current connection management and
260e1dd0a2th * the configuration it uses to become detached but continually being
261e1dd0a2th * used by the old MT connections. Any new MT connection opened will
262e1dd0a2th * be put in a new connection management and uses the new configuration
263e1dd0a2th * immediately.
264e1dd0a2th */
265e1dd0a2thtypedef enum {
266e1dd0a2th	NS_SERVER_UP	= 1,
267e1dd0a2th	NS_SERVER_DOWN	= 2
268e1dd0a2th} ns_server_status_t;
269e1dd0a2th
270e1dd0a2thtypedef struct ns_server_status_change {
271e1dd0a2th	int			num_server;
272e1dd0a2th	boolean_t		config_changed;
273e1dd0a2th	ns_server_status_t	*changes;	/* array of status change */
274e1dd0a2th	char			**servers;	/* array of server */
275e1dd0a2th} ns_server_status_change_t;
276e1dd0a2th
277e1dd0a2th/*
278e1dd0a2th * connection management functions
279e1dd0a2th */
280e1dd0a2thns_conn_mgmt_t *__s_api_conn_mgmt_init();
281e1dd0a2thint __s_api_setup_mt_ld(LDAP *ld);
282e1dd0a2thint __s_api_check_mtckey();
283e1dd0a2thvoid __s_api_use_prev_conn_mgmt(int, ns_config_t *);
284e1dd0a2thns_conn_user_t *__s_api_conn_user_init(int, void *, boolean_t);
285e1dd0a2thvoid __s_api_conn_mt_return(ns_conn_user_t *);
286e1dd0a2thvoid __s_api_conn_user_free(ns_conn_user_t *);
287e1dd0a2thint __s_api_conn_mt_add(Connection *con, ns_conn_user_t *, ns_ldap_error_t **);
288e1dd0a2thint __s_api_conn_mt_get(const char *, const int, const ns_cred_t *,
289e1dd0a2th	Connection **, ns_ldap_error_t **, ns_conn_user_t *);
290e1dd0a2thvoid __s_api_conn_mt_remove(ns_conn_user_t *, int, ns_ldap_error_t **);
291e1dd0a2thint __s_api_check_libldap_MT_conn_support(ns_conn_user_t *, LDAP *ld,
292e1dd0a2th	ns_ldap_error_t **);
293e1dd0a2thvoid __s_api_conn_mt_close(ns_conn_user_t *, int, ns_ldap_error_t **);
294e1dd0a2thvoid __s_api_reinit_conn_mgmt_new_config(ns_config_t *);
295e1dd0a2thint __s_api_setup_retry_search(ns_conn_user_t **, ns_conn_user_type_t, int *,
296e1dd0a2th	int *, ns_ldap_error_t **);
297e1dd0a2thint __s_api_setup_getnext(ns_conn_user_t *, int *, ns_ldap_error_t **);
298e1dd0a2thvoid __s_api_shutdown_conn_mgmt();
299e1dd0a2th
300e1dd0a2th#ifdef __cplusplus
301e1dd0a2th}
302e1dd0a2th#endif
303e1dd0a2th
304e1dd0a2th#endif /* _NS_CONNMGMT_H */
305