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 * $FreeBSD: src/lib/libc/gen/devname.c,v 1.2.2.2 2001/07/31 20:10:19 tmm Exp $ 34 * $DragonFly: src/lib/libc/gen/devname.c,v 1.6 2005/04/26 16:59:56 joerg Exp $ 35 * 36 * @(#)devname.c 8.2 (Berkeley) 4/29/95 37 */ 38 39 #include <sys/types.h> 40 #include <sys/stat.h> 41 #include <sys/sysctl.h> 42 43 #include <db.h> 44 #include <err.h> 45 #include <fcntl.h> 46 #include <paths.h> 47 #include <stdio.h> 48 #include <stdlib.h> 49 #include <string.h> 50 51 #define DEVNAME_DEVFS_COMPAT 1 52 53 #ifdef DEVNAME_DEVFS_COMPAT 54 static char * 55 xdevname(dev_t dev, mode_t type) 56 { 57 struct { 58 mode_t type; 59 dev_t dev; 60 } bkey; 61 static DB *db; 62 static int failure; 63 DBT data, key; 64 65 if (!db && !failure && 66 !(db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL))) { 67 warn("warning: %s", _PATH_DEVDB); 68 failure = 1; 69 } 70 if (failure) 71 return (NULL); 72 73 /* 74 * Keys are a mode_t followed by a dev_t. The former is the type of 75 * the file (mode & S_IFMT), the latter is the st_rdev field. Be 76 * sure to clear any padding that may be found in bkey. 77 */ 78 memset(&bkey, 0, sizeof(bkey)); 79 bkey.dev = dev; 80 bkey.type = type; 81 key.data = &bkey; 82 key.size = sizeof(bkey); 83 return ((db->get)(db, &key, &data, 0) ? NULL : (char *)data.data); 84 } 85 #endif 86 87 char * 88 devname_r(dev_t dev, mode_t type, char *buf, size_t len) 89 { 90 char *r; 91 size_t n = len; 92 93 if (sysctlbyname("kern.devname", buf, &n, &dev, sizeof(dev)) == 0) 94 return buf; 95 96 #ifdef DEVNAME_DEVFS_COMPAT 97 /* Fall back to old method if compat for devfs is set */ 98 /* First check the DB file. */ 99 r = xdevname(dev, type); 100 if (r != NULL) { 101 strlcpy(buf, r, len); 102 return (buf); 103 } 104 #endif 105 106 /* Finally just format it */ 107 snprintf(buf, len, "#%c%d:0x%x", 108 (type & S_IFMT) == S_IFCHR ? 'C' : 'B', 109 major(dev), minor(dev)); 110 111 return (buf); 112 } 113 114 char * 115 devname(dev_t dev, mode_t type) 116 { 117 static char buf[30]; /* XXX: pick up from <sys/conf.h> */ 118 119 strlcpy(buf, devname_r(dev, type, buf, sizeof(buf)), sizeof(buf)); 120 121 return (buf); 122 } 123