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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $FreeBSD: src/lib/libc/gen/devname.c,v 1.2.2.2 2001/07/31 20:10:19 tmm Exp $ 30 * $DragonFly: src/lib/libc/gen/devname.c,v 1.6 2005/04/26 16:59:56 joerg Exp $ 31 * 32 * @(#)devname.c 8.2 (Berkeley) 4/29/95 33 */ 34 35 #include <sys/types.h> 36 #include <sys/stat.h> 37 #include <sys/sysctl.h> 38 39 #include <db.h> 40 #include <err.h> 41 #include <fcntl.h> 42 #include <paths.h> 43 #include <stdio.h> 44 #include <stdlib.h> 45 #include <string.h> 46 47 #define DEVNAME_DEVFS_COMPAT 1 48 49 #ifdef DEVNAME_DEVFS_COMPAT 50 static char * 51 xdevname(dev_t dev, 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 #endif 82 83 char * 84 devname_r(dev_t dev, mode_t type, char *buf, size_t len) 85 { 86 char *r; 87 size_t n = len; 88 89 if (sysctlbyname("kern.devname", buf, &n, &dev, sizeof(dev)) == 0) 90 return buf; 91 92 #ifdef DEVNAME_DEVFS_COMPAT 93 /* Fall back to old method if compat for devfs is set */ 94 /* First check the DB file. */ 95 r = xdevname(dev, type); 96 if (r != NULL) { 97 strlcpy(buf, r, len); 98 return (buf); 99 } 100 #endif 101 102 /* Finally just format it */ 103 snprintf(buf, len, "#%c%d:0x%x", 104 (type & S_IFMT) == S_IFCHR ? 'C' : 'B', 105 major(dev), minor(dev)); 106 107 return (buf); 108 } 109 110 char * 111 devname(dev_t dev, mode_t type) 112 { 113 static char buf[30]; /* XXX: pick up from <sys/conf.h> */ 114 115 strlcpy(buf, devname_r(dev, type, buf, sizeof(buf)), sizeof(buf)); 116 117 return (buf); 118 } 119