3 * Bill Paul <wpaul@ctr.columbia.edu>. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
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11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by Bill Paul.
16 * 4. Neither the name of the author nor the names of any co-contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL Bill Paul OR CONTRIBUTORS BE LIABLE
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32 * $FreeBSD: src/usr.sbin/ypserv/yp_dblookup.c,v 1.25 2003/05/03 21:06:42 obrien Exp $
45 #include <sys/param.h>
46 #include <rpcsvc/yp.h>
47 #include "yp_extern.h"
50 enum ypstat yp_errno = YP_TRUE;
52 #define PERM_SECURE (S_IRUSR|S_IWUSR)
57 2048 * 512, /* cachesize */
63 #include <sys/queue.h>
69 static int numdbs = 0;
79 static TAILQ_HEAD(circlehead, circleq_entry) qhead;
81 struct circleq_entry {
83 TAILQ_ENTRY(circleq_entry) links;
87 * Initialize the circular queue.
96 * Dynamically allocate an entry for the circular queue.
97 * Return a NULL pointer on failure.
99 static struct circleq_entry *
102 struct circleq_entry *q;
104 q = (struct circleq_entry *)malloc(sizeof(struct circleq_entry));
106 yp_error("failed to malloc() circleq entry");
109 bzero((char *)q, sizeof(struct circleq_entry));
110 q->dbptr = (struct dbent *)malloc(sizeof(struct dbent));
111 if (q->dbptr == NULL) {
112 yp_error("failed to malloc() circleq entry");
116 bzero((char *)q->dbptr, sizeof(struct dbent));
122 * Free a previously allocated circular queue
126 yp_free_qent(struct circleq_entry *q)
129 * First, close the database. In theory, this is also
130 * supposed to free the resources allocated by the DB
131 * package, including the memory pointed to by q->dbptr->key.
132 * This means we don't have to free q->dbptr->key here.
135 q->dbptr->dbp->close(q->dbptr->dbp);
136 q->dbptr->dbp = NULL;
139 * Then free the database name, which was strdup()'ed.
141 free(q->dbptr->name);
144 * Free the rest of the dbent struct.
150 * Free the circleq struct.
157 * Zorch a single entry in the dbent queue and release
158 * all its resources. (This always removes the last entry
164 struct circleq_entry *qptr;
166 qptr = TAILQ_LAST(&qhead, circlehead);
167 TAILQ_REMOVE(&qhead, qptr, links);
173 * Close all databases, erase all database names and empty the queue.
178 struct circleq_entry *qptr;
180 while (!TAILQ_EMPTY(&qhead)) {
181 qptr = TAILQ_FIRST(&qhead); /* save this */
182 TAILQ_REMOVE(&qhead, qptr, links);
188 static char *inter_string = "YP_INTERDOMAIN";
189 static char *secure_string = "YP_SECURE";
190 static int inter_sz = sizeof("YP_INTERDOMAIN") - 1;
191 static int secure_sz = sizeof("YP_SECURE") - 1;
196 DBT key = { NULL, 0 }, data = { NULL, 0 };
199 key.data = inter_string;
202 if (!(dbp->get)(dbp, &key, &data, 0))
203 flags |= YP_INTERDOMAIN;
205 key.data = secure_string;
206 key.size = secure_sz;
208 if (!(dbp->get)(dbp, &key, &data, 0))
215 yp_testflag(char *map, char *domain, int flag)
217 char buf[MAXPATHLEN + 2];
218 struct circleq_entry *qptr;
220 if (map == NULL || domain == NULL)
227 TAILQ_FOREACH(qptr, &qhead, links) {
228 if (!strcmp(qptr->dbptr->name, buf)) {
229 if (qptr->dbptr->flags & flag)
236 if (yp_open_db_cache(domain, map, NULL, 0) == NULL)
239 if (TAILQ_FIRST(&qhead)->dbptr->flags & flag)
246 * Add a DB handle and database name to the cache. We only maintain
247 * fixed number of entries in the cache, so if we're asked to store
248 * a new entry when all our slots are already filled, we have to kick
249 * out the entry in the last slot to make room.
252 yp_cache_db(DB *dbp, char *name, int size)
254 struct circleq_entry *qptr;
256 if (numdbs == MAXDBS) {
258 yp_error("queue overflow -- releasing last slot");
263 * Allocate a new queue entry.
266 if ((qptr = yp_malloc_qent()) == NULL) {
267 yp_error("failed to allocate a new cache entry");
271 qptr->dbptr->dbp = dbp;
272 qptr->dbptr->name = strdup(name);
273 qptr->dbptr->size = size;
274 qptr->dbptr->key = NULL;
276 qptr->dbptr->flags = yp_setflags(dbp);
278 TAILQ_INSERT_HEAD(&qhead, qptr, links);
285 * Search the list for a database matching 'name.' If we find it,
286 * move it to the head of the list and return its DB handle. If
287 * not, just fail: yp_open_db_cache() will subsequently try to open
288 * the database itself and call yp_cache_db() to add it to the
291 * The search works like this:
293 * - The caller specifies the name of a database to locate. We try to
294 * find an entry in our queue with a matching name.
296 * - If the caller doesn't specify a key or size, we assume that the
297 * first entry that we encounter with a matching name is returned.
298 * This will result in matches regardless of the key/size values
299 * stored in the queue entry.
301 * - If the caller also specifies a key and length, we check to see
302 * if the key and length saved in the queue entry also matches.
303 * This lets us return a DB handle that's already positioned at the
304 * correct location within a database.
306 * - Once we have a match, it gets migrated to the top of the queue
307 * so that it will be easier to find if another request for
308 * the same database comes in later.
311 yp_find_db(const char *name, const char *key, const int size)
313 struct circleq_entry *qptr;
315 TAILQ_FOREACH(qptr, &qhead, links) {
316 if (!strcmp(qptr->dbptr->name, name)) {
318 if (size != qptr->dbptr->size ||
319 strncmp(qptr->dbptr->key, key, size))
322 if (qptr->dbptr->size)
325 if (qptr != TAILQ_FIRST(&qhead)) {
326 TAILQ_REMOVE(&qhead, qptr, links);
327 TAILQ_INSERT_HEAD(&qhead, qptr, links);
329 return(qptr->dbptr->dbp);
337 * Open a DB database and cache the handle for later use. We first
338 * check the cache to see if the required database is already open.
339 * If so, we fetch the handle from the cache. If not, we try to open
340 * the database and save the handle in the cache for later use.
343 yp_open_db_cache(const char *domain, const char *map, const char *key,
347 char buf[MAXPATHLEN + 2];
349 snprintf(buf, sizeof(buf), "%s/%s", domain, map);
357 if ((dbp = yp_find_db(buf, key, size)) != NULL) {
360 if ((dbp = yp_open_db(domain, map)) != NULL) {
361 if (yp_cache_db(dbp, buf, size)) {
374 * Open a DB database.
377 yp_open_db(const char *domain, const char *map)
380 char buf[MAXPATHLEN + 2];
384 if (map[0] == '.' || strchr(map, '/')) {
385 yp_errno = YP_BADARGS;
390 if (yp_validdomain(domain)) {
395 snprintf(buf, sizeof(buf), "%s/%s/%s", yp_dir, domain, map);
400 dbp = dbopen(buf,O_RDONLY, PERM_SECURE, DB_HASH, NULL);
407 * We ran out of file descriptors. Nuke an
408 * open one and try again.
410 yp_error("ran out of file descriptors");
431 * Database access routines.
433 * - yp_get_record(): retrieve an arbitrary key/data pair given one key
436 * - yp_first_record(): retrieve first key/data base in a database.
438 * - yp_next_record(): retrieve key/data pair that sequentially follows
439 * the supplied key value in the database.
444 yp_get_record(DB *dbp, const DBT *key, DBT *data, int allow)
447 yp_get_record(const char *domain, const char *map, const DBT *key,
448 DBT *data, int allow)
456 static unsigned char buf[YPMAXRECORD];
460 yp_error("looking up key [%.*s]",
461 (int)key->size, (char *)key->data);
464 * Avoid passing back magic "YP_*" entries unless
465 * the caller specifically requested them by setting
468 if (!allow && !strncmp(key->data, "YP_", 3))
472 if ((dbp = yp_open_db(domain, map)) == NULL) {
477 if ((rval = (dbp->get)(dbp, key, data, 0)) != 0) {
479 TAILQ_FIRST(&qhead)->dbptr->size = 0;
490 yp_error("result of lookup: key: [%.*s] data: [%.*s]",
491 (int)key->size, (char *)key->data,
492 (int)data->size, (char *)data->data);
495 if (TAILQ_FIRST(&qhead)->dbptr->size) {
496 TAILQ_FIRST(&qhead)->dbptr->key = "";
497 TAILQ_FIRST(&qhead)->dbptr->size = 0;
500 bcopy(data->data, &buf, data->size);
509 yp_first_record(const DB *dbp, DBT *key, DBT *data, int allow)
513 static unsigned char buf[YPMAXRECORD];
517 yp_error("retrieving first key in map");
519 if ((rval = (dbp->seq)(dbp,key,data,R_FIRST)) != 0) {
521 TAILQ_FIRST(&qhead)->dbptr->size = 0;
529 /* Avoid passing back magic "YP_*" records. */
530 while (!strncmp(key->data, "YP_", 3) && !allow) {
531 if ((rval = (dbp->seq)(dbp,key,data,R_NEXT)) != 0) {
533 TAILQ_FIRST(&qhead)->dbptr->size = 0;
543 yp_error("result of lookup: key: [%.*s] data: [%.*s]",
544 (int)key->size, (char *)key->data,
545 (int)data->size, (char *)data->data);
548 if (TAILQ_FIRST(&qhead)->dbptr->size) {
549 TAILQ_FIRST(&qhead)->dbptr->key = key->data;
550 TAILQ_FIRST(&qhead)->dbptr->size = key->size;
553 bcopy(data->data, &buf, data->size);
561 yp_next_record(const DB *dbp, DBT *key, DBT *data, int all, int allow)
563 static DBT lkey = { NULL, 0 };
564 static DBT ldata = { NULL, 0 };
567 static unsigned char keybuf[YPMAXRECORD];
568 static unsigned char datbuf[YPMAXRECORD];
571 if (key == NULL || !key->size || key->data == NULL) {
572 rval = yp_first_record(dbp,key,data,allow);
573 if (rval == YP_NOKEY)
577 TAILQ_FIRST(&qhead)->dbptr->key = key->data;
578 TAILQ_FIRST(&qhead)->dbptr->size = key->size;
585 yp_error("retrieving next key, previous was: [%.*s]",
586 (int)key->size, (char *)key->data);
590 if (TAILQ_FIRST(&qhead)->dbptr->key == NULL) {
592 (dbp->seq)(dbp,&lkey,&ldata,R_FIRST);
593 while (key->size != lkey.size ||
594 strncmp(key->data, lkey.data,
596 if ((dbp->seq)(dbp,&lkey,&ldata,R_NEXT)) {
598 TAILQ_FIRST(&qhead)->dbptr->size = 0;
608 if ((dbp->seq)(dbp,key,data,R_NEXT)) {
610 TAILQ_FIRST(&qhead)->dbptr->size = 0;
615 /* Avoid passing back magic "YP_*" records. */
616 while (!strncmp(key->data, "YP_", 3) && !allow)
617 if ((dbp->seq)(dbp,key,data,R_NEXT)) {
619 TAILQ_FIRST(&qhead)->dbptr->size = 0;
625 yp_error("result of lookup: key: [%.*s] data: [%.*s]",
626 (int)key->size, (char *)key->data,
627 (int)data->size, (char *)data->data);
630 if (TAILQ_FIRST(&qhead)->dbptr->size) {
631 TAILQ_FIRST(&qhead)->dbptr->key = key->data;
632 TAILQ_FIRST(&qhead)->dbptr->size = key->size;
635 bcopy(key->data, &keybuf, key->size);
637 lkey.size = key->size;
638 bcopy(data->data, &datbuf, data->size);
639 data->data = &datbuf;
647 * Database glue functions.
650 static DB *yp_currmap_db = NULL;
651 static int yp_allow_db = 0;
654 yp_select_map(char *map, char *domain, keydat *key, int allow)
657 yp_currmap_db = yp_open_db_cache(domain, map, NULL, 0);
659 yp_currmap_db = yp_open_db_cache(domain, map,
668 yp_getbykey(keydat *key, valdat *val)
670 DBT db_key = { NULL, 0 }, db_val = { NULL, 0 };
673 db_key.data = key->keydat_val;
674 db_key.size = key->keydat_len;
676 rval = yp_get_record(yp_currmap_db,
677 &db_key, &db_val, yp_allow_db);
679 if (rval == YP_TRUE) {
680 val->valdat_val = db_val.data;
681 val->valdat_len = db_val.size;
688 yp_firstbykey(keydat *key, valdat *val)
690 DBT db_key = { NULL, 0 }, db_val = { NULL, 0 };
693 rval = yp_first_record(yp_currmap_db, &db_key, &db_val, yp_allow_db);
695 if (rval == YP_TRUE) {
696 key->keydat_val = db_key.data;
697 key->keydat_len = db_key.size;
698 val->valdat_val = db_val.data;
699 val->valdat_len = db_val.size;
706 yp_nextbykey(keydat *key, valdat *val)
708 DBT db_key = { NULL, 0 }, db_val = { NULL, 0 };
711 db_key.data = key->keydat_val;
712 db_key.size = key->keydat_len;
714 rval = yp_next_record(yp_currmap_db, &db_key, &db_val, 0, yp_allow_db);
716 if (rval == YP_TRUE) {
717 key->keydat_val = db_key.data;
718 key->keydat_len = db_key.size;
719 val->valdat_val = db_val.data;
720 val->valdat_len = db_val.size;