FreeBSD-5.3/usr.sbin/ypserv/yp_dblookup.c
/*
* Copyright (c) 1995
* Bill Paul <wpaul@ctr.columbia.edu>. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Bill Paul.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL Bill Paul OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/usr.sbin/ypserv/yp_dblookup.c,v 1.25 2003/05/03 21:06:42 obrien Exp $");
#include <db.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <paths.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <rpcsvc/yp.h>
#include "yp_extern.h"
int ypdb_debug = 0;
enum ypstat yp_errno = YP_TRUE;
#define PERM_SECURE (S_IRUSR|S_IWUSR)
HASHINFO openinfo = {
4096, /* bsize */
32, /* ffactor */
256, /* nelem */
2048 * 512, /* cachesize */
NULL, /* hash */
0, /* lorder */
};
#ifdef DB_CACHE
#include <sys/queue.h>
#ifndef MAXDBS
#define MAXDBS 20
#endif
static int numdbs = 0;
struct dbent {
DB *dbp;
char *name;
char *key;
int size;
int flags;
};
static TAILQ_HEAD(circlehead, circleq_entry) qhead;
struct circleq_entry {
struct dbent *dbptr;
TAILQ_ENTRY(circleq_entry) links;
};
/*
* Initialize the circular queue.
*/
void
yp_init_dbs(void)
{
TAILQ_INIT(&qhead);
return;
}
/*
* Dynamically allocate an entry for the circular queue.
* Return a NULL pointer on failure.
*/
static struct circleq_entry *
yp_malloc_qent(void)
{
register struct circleq_entry *q;
q = (struct circleq_entry *)malloc(sizeof(struct circleq_entry));
if (q == NULL) {
yp_error("failed to malloc() circleq entry");
return(NULL);
}
bzero((char *)q, sizeof(struct circleq_entry));
q->dbptr = (struct dbent *)malloc(sizeof(struct dbent));
if (q->dbptr == NULL) {
yp_error("failed to malloc() circleq entry");
free(q);
return(NULL);
}
bzero((char *)q->dbptr, sizeof(struct dbent));
return(q);
}
/*
* Free a previously allocated circular queue
* entry.
*/
static void
yp_free_qent(struct circleq_entry *q)
{
/*
* First, close the database. In theory, this is also
* supposed to free the resources allocated by the DB
* package, including the memory pointed to by q->dbptr->key.
* This means we don't have to free q->dbptr->key here.
*/
if (q->dbptr->dbp) {
(void)(q->dbptr->dbp->close)(q->dbptr->dbp);
q->dbptr->dbp = NULL;
}
/*
* Then free the database name, which was strdup()'ed.
*/
free(q->dbptr->name);
/*
* Free the rest of the dbent struct.
*/
free(q->dbptr);
q->dbptr = NULL;
/*
* Free the circleq struct.
*/
free(q);
q = NULL;
return;
}
/*
* Zorch a single entry in the dbent queue and release
* all its resources. (This always removes the last entry
* in the queue.)
*/
static void
yp_flush(void)
{
register struct circleq_entry *qptr;
qptr = TAILQ_LAST(&qhead, circlehead);
TAILQ_REMOVE(&qhead, qptr, links);
yp_free_qent(qptr);
numdbs--;
return;
}
/*
* Close all databases, erase all database names and empty the queue.
*/
void
yp_flush_all(void)
{
register struct circleq_entry *qptr;
while (!TAILQ_EMPTY(&qhead)) {
qptr = TAILQ_FIRST(&qhead); /* save this */
TAILQ_REMOVE(&qhead, qptr, links);
yp_free_qent(qptr);
}
numdbs = 0;
return;
}
static char *inter_string = "YP_INTERDOMAIN";
static char *secure_string = "YP_SECURE";
static int inter_sz = sizeof("YP_INTERDOMAIN") - 1;
static int secure_sz = sizeof("YP_SECURE") - 1;
static int
yp_setflags(DB *dbp)
{
DBT key = { NULL, 0 }, data = { NULL, 0 };
int flags = 0;
key.data = inter_string;
key.size = inter_sz;
if (!(dbp->get)(dbp, &key, &data, 0))
flags |= YP_INTERDOMAIN;
key.data = secure_string;
key.size = secure_sz;
if (!(dbp->get)(dbp, &key, &data, 0))
flags |= YP_SECURE;
return(flags);
}
int
yp_testflag(char *map, char *domain, int flag)
{
char buf[MAXPATHLEN + 2];
register struct circleq_entry *qptr;
if (map == NULL || domain == NULL)
return(0);
strcpy(buf, domain);
strcat(buf, "/");
strcat(buf, map);
TAILQ_FOREACH(qptr, &qhead, links) {
if (!strcmp(qptr->dbptr->name, buf)) {
if (qptr->dbptr->flags & flag)
return(1);
else
return(0);
}
}
if (yp_open_db_cache(domain, map, NULL, 0) == NULL)
return(0);
if (TAILQ_FIRST(&qhead)->dbptr->flags & flag)
return(1);
return(0);
}
/*
* Add a DB handle and database name to the cache. We only maintain
* fixed number of entries in the cache, so if we're asked to store
* a new entry when all our slots are already filled, we have to kick
* out the entry in the last slot to make room.
*/
static int
yp_cache_db(DB *dbp, char *name, int size)
{
register struct circleq_entry *qptr;
if (numdbs == MAXDBS) {
if (ypdb_debug)
yp_error("queue overflow -- releasing last slot");
yp_flush();
}
/*
* Allocate a new queue entry.
*/
if ((qptr = yp_malloc_qent()) == NULL) {
yp_error("failed to allocate a new cache entry");
return(1);
}
qptr->dbptr->dbp = dbp;
qptr->dbptr->name = strdup(name);
qptr->dbptr->size = size;
qptr->dbptr->key = NULL;
qptr->dbptr->flags = yp_setflags(dbp);
TAILQ_INSERT_HEAD(&qhead, qptr, links);
numdbs++;
return(0);
}
/*
* Search the list for a database matching 'name.' If we find it,
* move it to the head of the list and return its DB handle. If
* not, just fail: yp_open_db_cache() will subsequently try to open
* the database itself and call yp_cache_db() to add it to the
* list.
*
* The search works like this:
*
* - The caller specifies the name of a database to locate. We try to
* find an entry in our queue with a matching name.
*
* - If the caller doesn't specify a key or size, we assume that the
* first entry that we encounter with a matching name is returned.
* This will result in matches regardless of the key/size values
* stored in the queue entry.
*
* - If the caller also specifies a key and length, we check to see
* if the key and length saved in the queue entry also matches.
* This lets us return a DB handle that's already positioned at the
* correct location within a database.
*
* - Once we have a match, it gets migrated to the top of the queue
* so that it will be easier to find if another request for
* the same database comes in later.
*/
static DB *
yp_find_db(const char *name, const char *key, int size)
{
register struct circleq_entry *qptr;
TAILQ_FOREACH(qptr, &qhead, links) {
if (!strcmp(qptr->dbptr->name, name)) {
if (size) {
if (size != qptr->dbptr->size ||
strncmp(qptr->dbptr->key, key, size))
continue;
} else {
if (qptr->dbptr->size)
continue;
}
if (qptr != TAILQ_FIRST(&qhead)) {
TAILQ_REMOVE(&qhead, qptr, links);
TAILQ_INSERT_HEAD(&qhead, qptr, links);
}
return(qptr->dbptr->dbp);
}
}
return(NULL);
}
/*
* Open a DB database and cache the handle for later use. We first
* check the cache to see if the required database is already open.
* If so, we fetch the handle from the cache. If not, we try to open
* the database and save the handle in the cache for later use.
*/
DB *
yp_open_db_cache(const char *domain, const char *map, const char *key,
const int size)
{
DB *dbp = NULL;
char buf[MAXPATHLEN + 2];
/*
snprintf(buf, sizeof(buf), "%s/%s", domain, map);
*/
yp_errno = YP_TRUE;
strcpy(buf, domain);
strcat(buf, "/");
strcat(buf, map);
if ((dbp = yp_find_db(buf, key, size)) != NULL) {
return(dbp);
} else {
if ((dbp = yp_open_db(domain, map)) != NULL) {
if (yp_cache_db(dbp, buf, size)) {
(void)(dbp->close)(dbp);
yp_errno = YP_YPERR;
return(NULL);
}
}
}
return (dbp);
}
#endif
/*
* Open a DB database.
*/
DB *
yp_open_db(const char *domain, const char *map)
{
DB *dbp = NULL;
char buf[MAXPATHLEN + 2];
yp_errno = YP_TRUE;
if (map[0] == '.' || strchr(map, '/')) {
yp_errno = YP_BADARGS;
return (NULL);
}
#ifdef DB_CACHE
if (yp_validdomain(domain)) {
yp_errno = YP_NODOM;
return(NULL);
}
#endif
snprintf(buf, sizeof(buf), "%s/%s/%s", yp_dir, domain, map);
#ifdef DB_CACHE
again:
#endif
dbp = dbopen(buf,O_RDONLY, PERM_SECURE, DB_HASH, NULL);
if (dbp == NULL) {
switch (errno) {
#ifdef DB_CACHE
case ENFILE:
/*
* We ran out of file descriptors. Nuke an
* open one and try again.
*/
yp_error("ran out of file descriptors");
yp_flush();
goto again;
break;
#endif
case ENOENT:
yp_errno = YP_NOMAP;
break;
case EFTYPE:
yp_errno = YP_BADDB;
break;
default:
yp_errno = YP_YPERR;
break;
}
}
return (dbp);
}
/*
* Database access routines.
*
* - yp_get_record(): retrieve an arbitrary key/data pair given one key
* to match against.
*
* - yp_first_record(): retrieve first key/data base in a database.
*
* - yp_next_record(): retrieve key/data pair that sequentially follows
* the supplied key value in the database.
*/
#ifdef DB_CACHE
int
yp_get_record(DB *dbp, const DBT *key, DBT *data, int allow)
#else
int
yp_get_record(const char *domain, const char *map,
const DBT *key, DBT *data, int allow)
#endif
{
#ifndef DB_CACHE
DB *dbp;
#endif
int rval = 0;
#ifndef DB_CACHE
static unsigned char buf[YPMAXRECORD];
#endif
if (ypdb_debug)
yp_error("looking up key [%.*s]",
(int)key->size, (char *)key->data);
/*
* Avoid passing back magic "YP_*" entries unless
* the caller specifically requested them by setting
* the 'allow' flag.
*/
if (!allow && !strncmp(key->data, "YP_", 3))
return(YP_NOKEY);
#ifndef DB_CACHE
if ((dbp = yp_open_db(domain, map)) == NULL) {
return(yp_errno);
}
#endif
if ((rval = (dbp->get)(dbp, key, data, 0)) != 0) {
#ifdef DB_CACHE
TAILQ_FIRST(&qhead)->dbptr->size = 0;
#else
(void)(dbp->close)(dbp);
#endif
if (rval == 1)
return(YP_NOKEY);
else
return(YP_BADDB);
}
if (ypdb_debug)
yp_error("result of lookup: key: [%.*s] data: [%.*s]",
(int)key->size, (char *)key->data,
(int)data->size, (char *)data->data);
#ifdef DB_CACHE
if (TAILQ_FIRST(&qhead)->dbptr->size) {
TAILQ_FIRST(&qhead)->dbptr->key = "";
TAILQ_FIRST(&qhead)->dbptr->size = 0;
}
#else
bcopy(data->data, &buf, data->size);
data->data = &buf;
(void)(dbp->close)(dbp);
#endif
return(YP_TRUE);
}
int
yp_first_record(const DB *dbp, DBT *key, DBT *data, int allow)
{
int rval;
#ifndef DB_CACHE
static unsigned char buf[YPMAXRECORD];
#endif
if (ypdb_debug)
yp_error("retrieving first key in map");
if ((rval = (dbp->seq)(dbp,key,data,R_FIRST)) != 0) {
#ifdef DB_CACHE
TAILQ_FIRST(&qhead)->dbptr->size = 0;
#endif
if (rval == 1)
return(YP_NOKEY);
else
return(YP_BADDB);
}
/* Avoid passing back magic "YP_*" records. */
while (!strncmp(key->data, "YP_", 3) && !allow) {
if ((rval = (dbp->seq)(dbp,key,data,R_NEXT)) != 0) {
#ifdef DB_CACHE
TAILQ_FIRST(&qhead)->dbptr->size = 0;
#endif
if (rval == 1)
return(YP_NOKEY);
else
return(YP_BADDB);
}
}
if (ypdb_debug)
yp_error("result of lookup: key: [%.*s] data: [%.*s]",
(int)key->size, (char *)key->data,
(int)data->size, (char *)data->data);
#ifdef DB_CACHE
if (TAILQ_FIRST(&qhead)->dbptr->size) {
TAILQ_FIRST(&qhead)->dbptr->key = key->data;
TAILQ_FIRST(&qhead)->dbptr->size = key->size;
}
#else
bcopy(data->data, &buf, data->size);
data->data = &buf;
#endif
return(YP_TRUE);
}
int
yp_next_record(const DB *dbp, DBT *key, DBT *data, int all, int allow)
{
static DBT lkey = { NULL, 0 };
static DBT ldata = { NULL, 0 };
int rval;
#ifndef DB_CACHE
static unsigned char keybuf[YPMAXRECORD];
static unsigned char datbuf[YPMAXRECORD];
#endif
if (key == NULL || !key->size || key->data == NULL) {
rval = yp_first_record(dbp,key,data,allow);
if (rval == YP_NOKEY)
return(YP_NOMORE);
else {
#ifdef DB_CACHE
TAILQ_FIRST(&qhead)->dbptr->key = key->data;
TAILQ_FIRST(&qhead)->dbptr->size = key->size;
#endif
return(rval);
}
}
if (ypdb_debug)
yp_error("retrieving next key, previous was: [%.*s]",
(int)key->size, (char *)key->data);
if (!all) {
#ifdef DB_CACHE
if (TAILQ_FIRST(&qhead)->dbptr->key == NULL) {
#endif
(dbp->seq)(dbp,&lkey,&ldata,R_FIRST);
while (key->size != lkey.size ||
strncmp(key->data, lkey.data,
(int)key->size))
if ((dbp->seq)(dbp,&lkey,&ldata,R_NEXT)) {
#ifdef DB_CACHE
TAILQ_FIRST(&qhead)->dbptr->size = 0;
#endif
return(YP_NOKEY);
}
#ifdef DB_CACHE
}
#endif
}
if ((dbp->seq)(dbp,key,data,R_NEXT)) {
#ifdef DB_CACHE
TAILQ_FIRST(&qhead)->dbptr->size = 0;
#endif
return(YP_NOMORE);
}
/* Avoid passing back magic "YP_*" records. */
while (!strncmp(key->data, "YP_", 3) && !allow)
if ((dbp->seq)(dbp,key,data,R_NEXT)) {
#ifdef DB_CACHE
TAILQ_FIRST(&qhead)->dbptr->size = 0;
#endif
return(YP_NOMORE);
}
if (ypdb_debug)
yp_error("result of lookup: key: [%.*s] data: [%.*s]",
(int)key->size, (char *)key->data,
(int)data->size, (char *)data->data);
#ifdef DB_CACHE
if (TAILQ_FIRST(&qhead)->dbptr->size) {
TAILQ_FIRST(&qhead)->dbptr->key = key->data;
TAILQ_FIRST(&qhead)->dbptr->size = key->size;
}
#else
bcopy(key->data, &keybuf, key->size);
lkey.data = &keybuf;
lkey.size = key->size;
bcopy(data->data, &datbuf, data->size);
data->data = &datbuf;
#endif
return(YP_TRUE);
}
#ifdef DB_CACHE
/*
* Database glue functions.
*/
static DB *yp_currmap_db = NULL;
static int yp_allow_db = 0;
ypstat
yp_select_map(char *map, char *domain, keydat *key, int allow)
{
if (key == NULL)
yp_currmap_db = yp_open_db_cache(domain, map, NULL, 0);
else
yp_currmap_db = yp_open_db_cache(domain, map,
key->keydat_val,
key->keydat_len);
yp_allow_db = allow;
return(yp_errno);
}
ypstat
yp_getbykey(keydat *key, valdat *val)
{
DBT db_key = { NULL, 0 }, db_val = { NULL, 0 };
ypstat rval;
db_key.data = key->keydat_val;
db_key.size = key->keydat_len;
rval = yp_get_record(yp_currmap_db,
&db_key, &db_val, yp_allow_db);
if (rval == YP_TRUE) {
val->valdat_val = db_val.data;
val->valdat_len = db_val.size;
}
return(rval);
}
ypstat
yp_firstbykey(keydat *key, valdat *val)
{
DBT db_key = { NULL, 0 }, db_val = { NULL, 0 };
ypstat rval;
rval = yp_first_record(yp_currmap_db, &db_key, &db_val, yp_allow_db);
if (rval == YP_TRUE) {
key->keydat_val = db_key.data;
key->keydat_len = db_key.size;
val->valdat_val = db_val.data;
val->valdat_len = db_val.size;
}
return(rval);
}
ypstat
yp_nextbykey(keydat *key, valdat *val)
{
DBT db_key = { NULL, 0 }, db_val = { NULL, 0 };
ypstat rval;
db_key.data = key->keydat_val;
db_key.size = key->keydat_len;
rval = yp_next_record(yp_currmap_db, &db_key, &db_val, 0, yp_allow_db);
if (rval == YP_TRUE) {
key->keydat_val = db_key.data;
key->keydat_len = db_key.size;
val->valdat_val = db_val.data;
val->valdat_len = db_val.size;
}
return(rval);
}
#endif