* Copyright (c) 1990, 1993

/* $NetBSD: ypdb.c,v 1.13 2023/08/01 08:47:25 mrg Exp $ */

/*
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Margo Seltzer.
*
* This code is derived from ndbm module of BSD4.4 db (hash) by
* Mats O Jansson
*
* 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. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 THE AUTHOR 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>
#ifndef lint
__RCSID("$NetBSD: ypdb.c,v 1.13 2023/08/01 08:47:25 mrg Exp $");
#endif

#include <sys/param.h>
#include <sys/types.h>
#include <sys/stat.h>

#include <db.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <rpcsvc/yp.h>

#include "ypdb.h"

static DBM *_ypdb_dbopen(const char *, int, mode_t);

/*
* ypdb_open --
* dbopen(3) file, read-only.
* First ensure that file has a suffix of YPDB_SUFFIX.
* Try opening as a DB_BTREE first, then DB_HASH.
*
* Returns:
* *DBM on success
* NULL on failure
*/

DBM *
ypdb_open(const char *file)
{
char path[MAXPATHLEN];
const char *cp, *suffix;

cp = strrchr(file, '.');
if (cp != NULL && strcmp(cp, YPDB_SUFFIX) == 0)
suffix = "";
else
suffix = YPDB_SUFFIX;
if ((size_t)snprintf(path, sizeof(path), "%s%s", file, suffix) >
sizeof(path)) {
warnx("File name `%s' is too long", file);
return NULL;
}
return _ypdb_dbopen(path, O_RDONLY, 0444);
}

/*
* ypdb_mktemp --
* Create a temporary file using mkstemp(3) based on the
* template provided in file.
* dbopen(3) file, read-write, 0644 (modified by umask(2)).
* Try opening as a DB_BTREE first, then DB_HASH.
* file won't have YPDB_SUFFIX.
*
* Returns:
* *DBM on success; file now exists.
* NULL on failure
*/

DBM *
ypdb_mktemp(char *file)
{
int fd = -1;
DBM *db = NULL;
mode_t myumask;
int save_errno;

if ((fd = mkstemp(file)) == -1)
return NULL;

myumask = umask(0);
(void)umask(myumask);
if (fchmod(fd, 0644 & ~myumask) == -1)
goto bad;

(void) close(fd);
fd = -1;

if ((db = _ypdb_dbopen(file, O_RDWR, 0644)) == NULL)
goto bad;

return db;

bad:
save_errno = errno;
if (fd != 1)
(void) close(fd);
(void) unlink(file);
errno = save_errno;
return NULL;
}

/*
* _ypdb_dbopen --
* dbopen(3) path with the flags & mode.
* Try opening as a DB_BTREE first, then DB_HASH.
*/

static DBM *
_ypdb_dbopen(const char *path, int flags, mode_t mode)
{
DBM *db;
BTREEINFO info;

/* try our btree format first */
info.flags = 0;
info.cachesize = 0;
info.maxkeypage = 0;
info.minkeypage = 0;
info.psize = 0;
info.compare = NULL;
info.prefix = NULL;
info.lorder = 0;
db = (DBM *)dbopen(path, flags, mode, DB_BTREE, (void *)&info);
if (db != NULL || errno != EFTYPE)
return (db);

/* fallback to standard hash (for sendmail's aliases.db) */
db = (DBM *)dbopen(path, flags, mode, DB_HASH, NULL);
return (db);
}

/*
* ypdb_close --
* Close the db
*/

void
ypdb_close(DBM *db)
{
(void)(db->close)(db);
}

/*
* Returns:
* DATUM on success
* NULL on failure
*/

datum
ypdb_fetch(DBM *db, datum key)
{
datum retkey;
DBT nk, nd;
int status;

nk.data = key.dptr;
nk.size = key.dsize;
status = (db->get)(db, &nk, &nd, 0);
if (status) {
retkey.dptr = NULL;
retkey.dsize = 0;
} else {
retkey.dptr = nd.data;
retkey.dsize = nd.size;
}
return (retkey);
}

/*
* Returns:
* DATUM on success
* NULL on failure
*/

datum
ypdb_firstkey(DBM *db)
{
int status;
datum retkey;
DBT nk, nd;

status = (db->seq)(db, &nk, &nd, R_FIRST);
if (status) {
retkey.dptr = NULL;
retkey.dsize = 0;
} else {
retkey.dptr = nk.data;
retkey.dsize = nk.size;
}
return (retkey);
}

/*
* Returns:
* DATUM on success
* NULL on failure
*/

datum
ypdb_nextkey(DBM *db)
{
int status;
datum retkey;
DBT nk, nd;

status = (db->seq)(db, &nk, &nd, R_NEXT);
if (status) {
retkey.dptr = NULL;
retkey.dsize = 0;
} else {
retkey.dptr = nk.data;
retkey.dsize = nk.size;
}
return (retkey);
}

/*
* Returns:
* DATUM on success
* NULL on failure
*/

datum
ypdb_setkey(DBM *db, datum key)
{
int status;
DBT nk, nd;

nk.data = key.dptr;
nk.size = key.dsize;
status = (db->seq)(db, &nk, &nd, R_CURSOR);
if (status) {
key.dptr = NULL;
key.dsize = 0;
}
return (key);
}

/*
* Returns:
* 0 on success
* <0 failure
*/

int
ypdb_delete(DBM *db, datum key)
{
int status;
DBT nk;

nk.data = key.dptr;
nk.size = key.dsize;
status = (db->del)(db, &nk, 0);
if (status)
return (-1);
else
return (0);
}

/*
* Returns:
* 0 on success
* <0 failure
* 1 if YPDB_INSERT and entry exists
*/

int
ypdb_store(DBM *db, datum key, datum content, int flags)
{
DBT nk, nd;

if (key.dsize > YPMAXRECORD || content.dsize > YPMAXRECORD)
return -1;
nk.data = key.dptr;
nk.size = key.dsize;
nd.data = content.dptr;
nd.size = content.dsize;
return ((db->put)(db, &nk, &nd,
(flags == YPDB_INSERT) ? R_NOOVERWRITE : 0));
}