NetBSD/lib/libc/gen/devname.c

94 lines
3.1 KiB
C

/* $NetBSD: devname.c,v 1.8 2000/01/22 22:19:09 mycroft Exp $ */
/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. 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 the University of
* California, Berkeley and its contributors.
* 4. 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 REGENTS 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 THE REGENTS 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>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)devname.c 8.2 (Berkeley) 4/29/95";
#else
__RCSID("$NetBSD: devname.c,v 1.8 2000/01/22 22:19:09 mycroft Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include <sys/types.h>
#include <db.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <err.h>
#ifdef __weak_alias
__weak_alias(devname,_devname)
#endif
char *
devname(dev, type)
dev_t dev;
mode_t type;
{
struct {
mode_t type;
dev_t dev;
} bkey;
static DB *db;
static int failure;
DBT data, key;
if (!db && !failure &&
!(db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL))) {
warn("warning: %s", _PATH_DEVDB);
failure = 1;
}
if (failure)
return (NULL);
/*
* Keys are a mode_t followed by a dev_t. The former is the type of
* the file (mode & S_IFMT), the latter is the st_rdev field. Be
* sure to clear any padding that may be found in bkey.
*/
memset(&bkey, 0, sizeof(bkey));
bkey.dev = dev;
bkey.type = type;
key.data = &bkey;
key.size = sizeof(bkey);
return ((db->get)(db, &key, &data, 0) ? NULL : (char *)data.data);
}