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 8.2 (Berkeley) 4/29/95"; 36 #endif /* LIBC_SCCS and not lint */ 37 38 #include <sys/types.h> 39 40 #include <db.h> 41 #include <err.h> 42 #include <errno.h> 43 #include <fcntl.h> 44 #include <paths.h> 45 #include <stdio.h> 46 #include <string.h> 47 48 char * 49 devname(dev, type) 50 dev_t dev; 51 mode_t type; 52 { 53 struct { 54 mode_t type; 55 dev_t dev; 56 } bkey; 57 static DB *db; 58 static int failure; 59 DBT data, key; 60 61 if (!db && !failure && 62 !(db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL))) { 63 warn("warning: %s", _PATH_DEVDB); 64 failure = 1; 65 } 66 if (failure) 67 return (NULL); 68 69 /* 70 * Keys are a mode_t followed by a dev_t. The former is the type of 71 * the file (mode & S_IFMT), the latter is the st_rdev field. Be 72 * sure to clear any padding that may be found in bkey. 73 */ 74 memset(&bkey, 0, sizeof(bkey)); 75 bkey.dev = dev; 76 bkey.type = type; 77 key.data = &bkey; 78 key.size = sizeof(bkey); 79 return ((db->get)(db, &key, &data, 0) ? NULL : (char *)data.data); 80 } 81