xref: /illumos-gate/usr/src/cmd/nscd/cache.h (revision 6a634c9d)
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 (c) 1994, 2010, Oracle and/or its affiliates. All rights reserved.
23  */
24 
25 #ifndef _NSCD_H
26 #define	_NSCD_H
27 
28 /*
29  * This is a private header file.  Applications should not directly include
30  * this file.
31  */
32 
33 #ifdef	__cplusplus
34 extern "C" {
35 #endif
36 
37 #include <sys/avl.h>
38 #include <thread.h>
39 #include <synch.h>
40 #include <nss_dbdefs.h>
41 #include "getxby_door.h"
42 #include "nscd_common.h"
43 #include "nscd_config.h"
44 
45 /*
46  * OR'D in by server to call self for updates
47  */
48 #define	UPDATEBIT	(1<<30)
49 #define	MASKUPDATEBIT(a) ((~UPDATEBIT)&(a))
50 
51 /*
52  * debug levels
53  */
54 #define	DBG_OFF		0
55 #define	DBG_CANT_FIND	2
56 #define	DBG_NETLOOKUPS	4
57 #define	DBG_ALL		6
58 
59 /*
60  * Max size name we allow to be passed to avoid
61  * buffer overflow problems
62  */
63 #define	NSCDMAXNAMELEN	255
64 
65 /*
66  * cached entry status
67  */
68 #define	ST_UPDATE_PENDING	0x1
69 #define	ST_LOOKUP_PENDING	0x2
70 #define	ST_PENDING		(ST_LOOKUP_PENDING | ST_UPDATE_PENDING)
71 #define	ST_NEW_ENTRY		0x4
72 #define	ST_DISCARD		0x8
73 
74 /*
75  * Cache eviction start and stop levels
76  */
77 #define	_NSC_EVICTION_START_LEVEL	90
78 #define	_NSC_EVICTION_SAFE_LEVEL	80
79 
80 /*
81  * other internal constants
82  */
83 #define	_NSC_MAX_DB		3
84 #define	_NSC_PUBLIC_ACCESS	-1
85 #define	_NSC_FILE_CHECK_TIME	0	/* check always for backwards compat */
86 
87 /*
88  * Macros used for logging purposes
89  */
90 #define	yes_no(flag)	(flag == nscd_true)?"yes":"no"
91 #define	check_null(str)	(str)?str:"<null>"
92 
93 /*
94  * Macros used by compare routines
95  */
96 #define	_NSC_INT_KEY_CMP(n1, n2) \
97 	(n1 > n2)?1:((n1 == n2)?0:-1)
98 
99 #define	_NSC_GET_HITRATE(sp) \
100 	sp->hitrate = sp->pos_misses + sp->neg_misses + \
101 		sp->pos_hits + sp->neg_hits; \
102 	if (sp->hitrate > 0.0) \
103 		sp->hitrate = (100.0 * \
104 			((double)sp->pos_hits + \
105 			(double)sp->neg_hits)) / sp->hitrate;
106 
107 /*
108  * nsc_lookup action
109  */
110 typedef enum {
111 	_NSC_NSLOOKUP = 0,
112 	_NSC_WAIT,
113 	_NSC_USECACHED
114 } nsc_action_t;
115 
116 /*
117  *  What each entry in the nameserver cache looks like.
118  */
119 
120 typedef struct nsc_entry_stat {
121 	uint_t		hits;		/* number of hits */
122 	uint8_t		status;		/* activity status */
123 	time_t		timestamp;	/* expiry time */
124 	int 		refcount;	/* reference count */
125 } nsc_entry_stat_t;
126 
127 typedef struct nsc_entry {
128 	avl_node_t		avl_link;	/* libavl requirement */
129 	struct nsc_entry 	*qnext;		/* next on pqueue */
130 	struct nsc_entry 	*qprev;		/* prev on pqueue */
131 	nsc_entry_stat_t	stats;		/* entry's statistics */
132 	nss_XbyY_key_t		key;		/* entry's key */
133 	void			*buffer;	/* data buffer */
134 	size_t			bufsize;	/* data buffer length */
135 } nsc_entry_t;
136 
137 typedef struct nsc_keephot {
138 	void	*ptr;
139 	uint_t	num;
140 } nsc_keephot_t;
141 
142 /*
143  * Structure to handle waiting for pending name service requests
144  */
145 typedef struct waiter {
146 	cond_t		w_waitcv;
147 	uint8_t		w_signaled;
148 	nsc_entry_t	*w_key;
149 	struct waiter	*w_next, *w_prev;
150 } waiter_t;
151 
152 /*
153  * Macros used by hash table
154  *
155  * _NSC_HTSIZE_PRIMES are prime numbers that are used as hash table
156  * sizes when hash table type is nsc_ht_prime. For hash tables of
157  * type nsc_ht_power2, the size is automatically calculated.
158  * Number of primes listed below is _NSC_HTSIZE_NUM_SLOTS + 1.
159  * Each number (except the first) is a prime closest to a
160  * power of 2 in increasing order. Ex: 509 is the closest prime to
161  * 512 (2**9), 1021 is closest to 1024 (2**10), and so on.
162  * The first prime is chosen as 211 for historical reasons.
163  */
164 #define	_NSC_INIT_HTSIZE_PRIME	211
165 #define	_NSC_INIT_HTSIZE_POWER2	256
166 #define	_NSC_INIT_HTSIZE_SLOT_VALUE	2896
167 #define	_NSC_HTSIZE_NUM_SLOTS	10
168 #define	_NSC_HTSIZE_PRIMES	211, 509, 1021, 2053, 4099, 8191, \
169 				16381, 32771, 65537, 131071, 262147
170 
171 #define	_NSC_DB_CES_KEY(ptr) \
172 		((ptr)->db_type == nsc_key_ces)
173 #define	_NSC_DB_CIS_KEY(ptr) \
174 		((ptr)->db_type == nsc_key_cis)
175 #define	_NSC_DB_STR_KEY(ptr) \
176 		_NSC_DB_CES_KEY(ptr) || _NSC_DB_CIS_KEY(ptr)
177 #define	_NSC_DB_INT_KEY(ptr) \
178 		((ptr)->db_type == nsc_key_int)
179 
180 /*
181  * cache backend param group (global)
182  */
183 #define	NSCD_CFG_GROUP_INFO_GLOBAL_CACHE	{1, 0x0001}
184 typedef struct nscd_cfg_global_cache {
185 	nscd_cfg_group_info_t	gi;	/* config requirement */
186 	nscd_bool_t	enable;
187 } nscd_cfg_global_cache_t;
188 
189 #define	NSCD_CFG_GLOBAL_CACHE_DEFAULTS \
190 	{ NSCD_CFG_GROUP_INFO_GLOBAL_CACHE, nscd_true }
191 
192 /*
193  * cache backend param group (per database)
194  */
195 #define	NSCD_CFG_GROUP_INFO_CACHE	{12, 0x0fff}
196 typedef struct nscd_cfg_cache {
197 	nscd_cfg_group_info_t	gi;	/* config requirement */
198 	nscd_bool_t	enable;		/* if false return NOSERVER */
199 	nscd_bool_t	per_user;	/* if true per user access */
200 	nscd_bool_t	avoid_ns;	/* if true avoid name service */
201 	nscd_bool_t	check_files;	/* if true check file */
202 	int		check_interval;	/* check interval */
203 	int		pos_ttl;	/* time to live for +ve entries */
204 	int		neg_ttl;	/* time to live for -ve entries */
205 	int		keephot;	/* keep hot count */
206 	int		hint_size;	/* size to return for a GETHINTS */
207 	ulong_t		maxentries;	/* maximum entries allowed */
208 	int		suggestedsize;	/* obsolete */
209 	nscd_bool_t	old_data_ok;	/* obsolete */
210 } nscd_cfg_cache_t;
211 
212 #define	NSCD_CFG_CACHE_DEFAULTS \
213 	{ \
214 		NSCD_CFG_GROUP_INFO_CACHE, \
215 		nscd_true, nscd_false, nscd_false, nscd_true, \
216 		_NSC_FILE_CHECK_TIME, 600, 10, 0, 1 << 11, 0, \
217 		0,  nscd_false \
218 	}
219 
220 /*
221  * cache backend stat group (per database)
222  */
223 #define	NSCD_CFG_STAT_GROUP_INFO_CACHE	{9, 0x01ff}
224 typedef struct nscd_cfg_stat_cache {
225 	nscd_cfg_group_info_t	gi;	/* config requirement */
226 	ulong_t	pos_hits;		/* hits on +ve entries */
227 	ulong_t	neg_hits;		/* hits on -ve entries */
228 	ulong_t	pos_misses;		/* misses on +ve entries */
229 	ulong_t	neg_misses;		/* misses on -ve entries */
230 	ulong_t	entries;		/* count of cache entries */
231 	ulong_t	drop_count;		/* cache queries dropped */
232 	ulong_t	wait_count;		/* cache queries queued */
233 	ulong_t	invalidate_count;	/* count for cache invalidation */
234 	double	hitrate;		/* computed from other fields */
235 } nscd_cfg_stat_cache_t;
236 
237 typedef struct nsc_db {
238 	/*
239 	 * Data
240 	 */
241 	avl_tree_t	tree;
242 	nsc_entry_t	**htable;
243 	nsc_entry_t	*qhead;
244 	nsc_entry_t	*qtail;
245 	nsc_entry_t	*reap_node;
246 	int 		callnumber;
247 	int		dbop;
248 	char 		*name;
249 	mutex_t		db_mutex;
250 	waiter_t	db_wait;	/* lookup wait CV */
251 	int		htsize;
252 	enum hash_type {
253 		nsc_ht_default = 0,
254 		nsc_ht_prime = 1,
255 		nsc_ht_power2 = 2
256 	} hash_type;
257 	enum db_type {
258 		nsc_key_ces = 0,
259 		nsc_key_cis = 1,
260 		nsc_key_int = 2,
261 		nsc_key_other = 3
262 	} db_type;
263 	/*
264 	 * Methods
265 	 */
266 	uint_t (*gethash)(nss_XbyY_key_t *, int);
267 	int (*compar)(const void *, const void *);
268 	void (*getlogstr)(char *, char *, size_t, nss_XbyY_args_t *);
269 	/*
270 	 * Config
271 	 */
272 	nscd_cfg_cache_t	cfg;
273 	time_t			cfg_mtime;
274 } nsc_db_t;
275 
276 
277 typedef struct nsc_ctx {
278 	char 		*dbname;		/* cache name */
279 	nscd_cfg_stat_cache_t	stats;		/* statistics */
280 	nscd_cfg_cache_t	cfg;		/* configs */
281 	time_t		cfg_mtime;		/* config last modified time */
282 	rwlock_t	cfg_rwlp;		/* config rwlock */
283 	mutex_t		stats_mutex;		/* stats mutex */
284 	mutex_t		file_mutex;		/* file mutex */
285 	time_t		file_mtime;		/* file last modified time */
286 	time_t		file_chktime; 		/* file last checked time */
287 	off_t		file_size;		/* file size at last check */
288 	ino_t		file_ino;		/* file inode at last check */
289 	const char 	*file_name;		/* filename for check_files */
290 	int		db_count;	/* number of caches, max _NSC_MAX_DB */
291 	nsc_db_t 	*nsc_db[_NSC_MAX_DB];	/* caches */
292 	sema_t		throttle_sema;		/* throttle lookups */
293 	sema_t		revalidate_sema;	/* revalidation threads */
294 	nscd_bool_t	revalidate_on;		/* reval. thread started */
295 	nscd_bool_t	reaper_on;		/* reaper thread started */
296 } nsc_ctx_t;
297 
298 typedef struct nsc_lookup_args {
299 	nsc_ctx_t	*ctx;
300 	nsc_db_t	*nscdb;
301 	void		*buffer;
302 	size_t		bufsize;
303 } nsc_lookup_args_t;
304 
305 #define	CACHE_CTX_COUNT	19
306 
307 /* Context initialization */
308 extern void passwd_init_ctx(nsc_ctx_t *);
309 extern void group_init_ctx(nsc_ctx_t *);
310 extern void host_init_ctx(nsc_ctx_t *);
311 extern void ipnode_init_ctx(nsc_ctx_t *);
312 extern void exec_init_ctx(nsc_ctx_t *);
313 extern void prof_init_ctx(nsc_ctx_t *);
314 extern void user_init_ctx(nsc_ctx_t *);
315 extern void ether_init_ctx(nsc_ctx_t *);
316 extern void rpc_init_ctx(nsc_ctx_t *);
317 extern void proto_init_ctx(nsc_ctx_t *);
318 extern void net_init_ctx(nsc_ctx_t *);
319 extern void bootp_init_ctx(nsc_ctx_t *);
320 extern void auth_init_ctx(nsc_ctx_t *);
321 extern void serv_init_ctx(nsc_ctx_t *);
322 extern void netmask_init_ctx(nsc_ctx_t *);
323 extern void printer_init_ctx(nsc_ctx_t *);
324 extern void project_init_ctx(nsc_ctx_t *);
325 extern void tnrhtp_init_ctx(nsc_ctx_t *);
326 extern void tnrhdb_init_ctx(nsc_ctx_t *);
327 
328 /* Functions used to throttle threads */
329 extern int nscd_wait(nsc_ctx_t *, nsc_db_t *, nsc_entry_t *);
330 extern int nscd_signal(nsc_ctx_t *, nsc_db_t *, nsc_entry_t *);
331 
332 /* Cache creation and initialization */
333 extern nscd_rc_t init_cache();
334 extern nsc_db_t *make_cache(enum db_type, int, char *,
335 	int (*compar) (const void *, const void *),
336 	void (*getlogstr)(char *, char *, size_t, nss_XbyY_args_t *),
337 	uint_t (*gethash)(nss_XbyY_key_t *, int),
338 	enum hash_type, int);
339 
340 /* Cache backend lookup */
341 extern void nsc_lookup(nsc_lookup_args_t *, int);
342 
343 /* Cache backend info */
344 extern void nsc_info(nsc_ctx_t *, char *, nscd_cfg_cache_t cfg[],
345 		nscd_cfg_stat_cache_t stats[]);
346 #ifdef NSCD_DEBUG
347 extern int nsc_dump(char *, int);
348 #endif	/* NSCD_DEBUG */
349 
350 /* Cache invalidate */
351 extern void nsc_invalidate(nsc_ctx_t *, char *, nsc_ctx_t **);
352 
353 /* Keep hot functions */
354 extern nsc_keephot_t *maken(int);
355 extern void *insertn(nsc_keephot_t *, uint_t, void *);
356 
357 /* hash related routines */
358 extern uint_t cis_gethash(const char *, int);
359 extern uint_t ces_gethash(const char *, int);
360 extern uint_t db_gethash(const void *, int, int);
361 
362 extern void leave(int n);
363 extern int get_cache_idx(char *);
364 
365 #ifdef	__cplusplus
366 }
367 #endif
368 
369 #endif	/* _NSCD_H */
370