1 /* $OpenBSD: devname.c,v 1.7 2006/03/31 00:41:20 deraadt Exp $ */ 2 /* 3 * Copyright (c) 1989, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <sys/types.h> 32 33 #include <db.h> 34 #include <err.h> 35 #include <errno.h> 36 #include <fcntl.h> 37 #include <paths.h> 38 #include <stdio.h> 39 #include <string.h> 40 #include <stdlib.h> 41 42 char * 43 devname(int dev, mode_t type) 44 { 45 struct { 46 mode_t type; 47 dev_t dev; 48 } bkey; 49 static DB *db; 50 static int failure; 51 DBT data, key; 52 53 if (!db && !failure && 54 !(db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL))) { 55 _warn("warning: %s", _PATH_DEVDB); 56 failure = 1; 57 } 58 if (failure) 59 return ("??"); 60 61 /* 62 * Keys are a mode_t followed by a dev_t. The former is the type of 63 * the file (mode & S_IFMT), the latter is the st_rdev field. Be 64 * sure to clear any padding that may be found in bkey. 65 */ 66 memset(&bkey, 0, sizeof(bkey)); 67 bkey.dev = dev; 68 bkey.type = type; 69 key.data = &bkey; 70 key.size = sizeof(bkey); 71 return ((db->get)(db, &key, &data, 0) ? "??" : (char *)data.data); 72 } 73