freebsd-skq/lib/libc/gen/devname.c

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/*
* 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.
*
* $FreeBSD$
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*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)devname.c 8.2 (Berkeley) 4/29/95";
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#endif /* LIBC_SCCS and not lint */
#include <sys/types.h>
#include <sys/sysctl.h>
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#include <db.h>
#include <err.h>
#include <fcntl.h>
#include <paths.h>
#include <stdio.h>
#include <string.h>
#include <sys/param.h>
#include <sys/stat.h>
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static char *
xdevname(dev, type)
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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)))
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failure = 1;
if (failure)
return (NULL);
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/*
* 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);
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}
char *
devname(dev, type)
dev_t dev;
mode_t type;
{
static char buf[SPECNAMELEN + 1];
int i;
size_t j;
char *r;
/* First check the DB file. */
r = xdevname(dev, type);
if (r != NULL)
return (r);
/* Then ask the kernel. */
if ((type & S_IFMT) == S_IFCHR) {
j = sizeof(buf);
i = sysctlbyname("kern.devname", buf, &j, &dev, sizeof (dev));
if (i == 0)
return (buf);
}
/* Finally just format it */
if (minor(dev) > 255)
r = "#%c:%d:0x%x";
else
r = "#%c:%d:0x%d";
snprintf(buf, SPECNAMELEN + 1, r,
(type & S_IFMT) == S_IFCHR ? 'C' : 'B', major(dev), minor(dev));
return (buf);
}