Home | History | Annotate | Line # | Download | only in gen
devname.c revision 1.3.2.1 
      1 /*
      2  * Copyright (c) 1989, 1993
      3  *	The Regents of the University of California.  All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  * 3. All advertising materials mentioning features or use of this software
     14  *    must display the following acknowledgement:
     15  *	This product includes software developed by the University of
     16  *	California, Berkeley and its contributors.
     17  * 4. Neither the name of the University nor the names of its contributors
     18  *    may be used to endorse or promote products derived from this software
     19  *    without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     31  * SUCH DAMAGE.
     32  */
     33 
     34 #if defined(LIBC_SCCS) && !defined(lint)
     35 static char sccsid[] = "@(#)devname.c	8.1 (Berkeley) 6/4/93";
     36 #endif /* LIBC_SCCS and not lint */
     37 
     38 #include "namespace.h"
     39 #include <sys/types.h>
     40 
     41 #include <db.h>
     42 #include <err.h>
     43 #include <errno.h>
     44 #include <fcntl.h>
     45 #include <paths.h>
     46 #include <stdio.h>
     47 #include <string.h>
     48 
     49 char *
     50 devname(dev, type)
     51 	dev_t dev;
     52 	mode_t type;
     53 {
     54 	struct {
     55 		mode_t type;
     56 		dev_t dev;
     57 	} bkey;
     58 	static DB *db;
     59 	static int failure;
     60 	DBT data, key;
     61 
     62 	if (!db && !failure &&
     63 	    !(db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL))) {
     64 		_warn("warning: %s", _PATH_DEVDB);
     65 		failure = 1;
     66 	}
     67 	if (failure)
     68 		return ("??");
     69 
     70 	/*
     71 	 * Keys are a mode_t followed by a dev_t.  The former is the type of
     72 	 * the file (mode & S_IFMT), the latter is the st_rdev field.  Be
     73 	 * sure to clear any padding that may be found in bkey.
     74 	 */
     75 	memset(&bkey, 0, sizeof(bkey));
     76 	bkey.dev = dev;
     77 	bkey.type = type;
     78 	key.data = &bkey;
     79 	key.size = sizeof(bkey);
     80 	return ((db->get)(db, &key, &data, 0) ? "??" : (char *)data.data);
     81 }
     82