devname.c revision 23658
11573Srgrimes/* 21573Srgrimes * Copyright (c) 1989, 1993 31573Srgrimes * The Regents of the University of California. All rights reserved. 41573Srgrimes * 51573Srgrimes * Redistribution and use in source and binary forms, with or without 61573Srgrimes * modification, are permitted provided that the following conditions 71573Srgrimes * are met: 81573Srgrimes * 1. Redistributions of source code must retain the above copyright 91573Srgrimes * notice, this list of conditions and the following disclaimer. 101573Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 111573Srgrimes * notice, this list of conditions and the following disclaimer in the 121573Srgrimes * documentation and/or other materials provided with the distribution. 131573Srgrimes * 3. All advertising materials mentioning features or use of this software 141573Srgrimes * must display the following acknowledgement: 151573Srgrimes * This product includes software developed by the University of 161573Srgrimes * California, Berkeley and its contributors. 171573Srgrimes * 4. Neither the name of the University nor the names of its contributors 181573Srgrimes * may be used to endorse or promote products derived from this software 191573Srgrimes * without specific prior written permission. 201573Srgrimes * 211573Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 221573Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 231573Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 241573Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 251573Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 261573Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 271573Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 281573Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 291573Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 301573Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 311573Srgrimes * SUCH DAMAGE. 321573Srgrimes */ 331573Srgrimes 341573Srgrimes#if defined(LIBC_SCCS) && !defined(lint) 3523658Speterstatic char sccsid[] = "@(#)devname.c 8.2 (Berkeley) 4/29/95"; 361573Srgrimes#endif /* LIBC_SCCS and not lint */ 371573Srgrimes 381573Srgrimes#include <sys/types.h> 391573Srgrimes 401573Srgrimes#include <db.h> 411573Srgrimes#include <err.h> 421573Srgrimes#include <errno.h> 431573Srgrimes#include <fcntl.h> 441573Srgrimes#include <paths.h> 451573Srgrimes#include <stdio.h> 461573Srgrimes#include <string.h> 471573Srgrimes 481573Srgrimeschar * 491573Srgrimesdevname(dev, type) 501573Srgrimes dev_t dev; 511573Srgrimes mode_t type; 521573Srgrimes{ 531573Srgrimes struct { 541573Srgrimes mode_t type; 551573Srgrimes dev_t dev; 561573Srgrimes } bkey; 571573Srgrimes static DB *db; 581573Srgrimes static int failure; 591573Srgrimes DBT data, key; 601573Srgrimes 611573Srgrimes if (!db && !failure && 621573Srgrimes !(db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL))) { 631573Srgrimes warn("warning: %s", _PATH_DEVDB); 641573Srgrimes failure = 1; 651573Srgrimes } 661573Srgrimes if (failure) 6723658Speter return (NULL); 681573Srgrimes 691573Srgrimes /* 701573Srgrimes * Keys are a mode_t followed by a dev_t. The former is the type of 711573Srgrimes * the file (mode & S_IFMT), the latter is the st_rdev field. Be 721573Srgrimes * sure to clear any padding that may be found in bkey. 731573Srgrimes */ 741573Srgrimes memset(&bkey, 0, sizeof(bkey)); 751573Srgrimes bkey.dev = dev; 761573Srgrimes bkey.type = type; 771573Srgrimes key.data = &bkey; 781573Srgrimes key.size = sizeof(bkey); 7923658Speter return ((db->get)(db, &key, &data, 0) ? NULL : (char *)data.data); 801573Srgrimes} 81