minix/lib/nbsd_libc/gen/devname.c

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/* $NetBSD: devname.c,v 1.21 2010/03/23 20:28:59 drochner Exp $ */
/*-
* Copyright (c) 2000 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Simon Burge.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*-
* Copyright (c) 1992 Keith Muller.
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Keith Muller of the University of California, San Diego.
*
* 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 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 1.21 2010/03/23 20:28:59 drochner Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <db.h>
#include <fcntl.h>
#include <paths.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <err.h>
#define DEV_SZ 317 /* show be prime for best results */
#define VALID 1 /* entry and devname are valid */
#define INVALID 2 /* entry valid, devname NOT valid */
typedef struct devc {
int valid; /* entry valid? */
dev_t dev; /* cached device */
mode_t type; /* cached file type */
char name[NAME_MAX]; /* device name */
} DEVC;
char *
devname(dev, type)
dev_t dev;
mode_t type;
{
struct {
mode_t type;
dev_t dev;
} bkey;
struct {
mode_t type;
int32_t dev;
} obkey;
static DB *db;
static int failure;
DBT data, key;
DEVC *ptr, **pptr;
static DEVC **devtb = NULL;
static devmajor_t pts;
static int pts_valid = 0;
if (!db && !failure &&
!(db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL))) {
warn("warning: %s", _PATH_DEVDB);
failure = 1;
}
/* initialise dev cache */
if (!failure && devtb == NULL) {
devtb = calloc(DEV_SZ, sizeof(DEVC *));
if (devtb == NULL)
failure= 1;
}
if (failure)
return (NULL);
/* see if we have this dev/type cached */
pptr = devtb + (size_t)((dev + type) % DEV_SZ);
ptr = *pptr;
if (ptr && ptr->valid > 0 && ptr->dev == dev && ptr->type == type) {
if (ptr->valid == VALID)
return (ptr->name);
return (NULL);
}
if (ptr == NULL)
*pptr = ptr = malloc(sizeof(DEVC));
/*
* 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.
*/
(void)memset(&bkey, 0, sizeof(bkey));
bkey.dev = dev;
bkey.type = type;
key.data = &bkey;
key.size = sizeof(bkey);
if ((db->get)(db, &key, &data, 0) == 0) {
found_it:
if (ptr == NULL)
return (char *)data.data;
ptr->dev = dev;
ptr->type = type;
strncpy(ptr->name, (char *)data.data, NAME_MAX);
ptr->name[NAME_MAX - 1] = '\0';
ptr->valid = VALID;
} else {
/* Look for a 32 bit dev_t. */
(void)memset(&obkey, 0, sizeof(obkey));
obkey.dev = (int32_t)(uint32_t)dev;
obkey.type = type;
key.data = &obkey;
key.size = sizeof(obkey);
if ((db->get)(db, &key, &data, 0) == 0)
goto found_it;
if (ptr == NULL)
return (NULL);
ptr->valid = INVALID;
if (type == S_IFCHR) {
if (!pts_valid) {
pts = getdevmajor("pts", S_IFCHR);
pts_valid = 1;
}
if (pts != NODEVMAJOR && major(dev) == pts) {
(void)snprintf(ptr->name, sizeof(ptr->name),
"%s%d", _PATH_DEV_PTS +
sizeof(_PATH_DEV) - 1,
minor(dev));
ptr->valid = VALID;
}
}
ptr->dev = dev;
ptr->type = type;
}
if (ptr->valid == VALID)
return (ptr->name);
else
return (NULL);
}