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 1.4 2004/01/06 15:38:09 eirikn Exp $ 35 * 36 * @(#)devname.c 8.2 (Berkeley) 4/29/95 37 */ 38 39 #include <sys/types.h> 40 #include <sys/sysctl.h> 41 42 #include <db.h> 43 #include <err.h> 44 #include <errno.h> 45 #include <fcntl.h> 46 #include <paths.h> 47 #include <stdio.h> 48 #include <string.h> 49 #include <sys/stat.h> 50 51 static char * 52 xdevname(dev_t dev, mode_t type) 53 { 54 struct { 55 mode_t type; 56 dev_t dev; 57 } bkey; 58 static DB *db; 59 static int failure; 60 DBT data, key; 61 62 if (!db && !failure && 63 !(db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL))) { 64 warn("warning: %s", _PATH_DEVDB); 65 failure = 1; 66 } 67 if (failure) 68 return (NULL); 69 70 /* 71 * Keys are a mode_t followed by a dev_t. The former is the type of 72 * the file (mode & S_IFMT), the latter is the st_rdev field. Be 73 * sure to clear any padding that may be found in bkey. 74 */ 75 memset(&bkey, 0, sizeof(bkey)); 76 bkey.dev = dev; 77 bkey.type = type; 78 key.data = &bkey; 79 key.size = sizeof(bkey); 80 return ((db->get)(db, &key, &data, 0) ? NULL : (char *)data.data); 81 } 82 83 char * 84 devname_r(dev_t dev, mode_t type, char *buf, size_t len) 85 { 86 int i; 87 size_t j; 88 char *r; 89 90 /* First check the DB file. */ 91 r = xdevname(dev, type); 92 if (r != NULL) { 93 strlcpy(buf, r, len); 94 return (buf); 95 } 96 97 #if 0 98 /* The kern.devname sysctl does not exist */ 99 /* Then ask the kernel. */ 100 if ((type & S_IFMT) == S_IFCHR) { 101 j = sizeof(buf); 102 i = sysctlbyname("kern.devname", buf, &j, &dev, sizeof (dev)); 103 if (i == 0) 104 return (buf); 105 } 106 #endif 107 108 /* Finally just format it */ 109 if (minor(dev) > 255) { 110 snprintf(buf, len, "#%c%d:0x%x", 111 (type & S_IFMT) == S_IFCHR ? 'C' : 'B', 112 major(dev), minor(dev)); 113 } else { 114 snprintf(buf, len, "#%c%d:%d", 115 (type & S_IFMT) == S_IFCHR ? 'C' : 'B', 116 major(dev), minor(dev)); 117 } 118 return (buf); 119 } 120 121 char * 122 devname(dev_t dev, mode_t type) 123 { 124 static char buf[30]; /* XXX: pick up from <sys/conf.h> */ 125 126 strncpy(buf, devname_r(dev, type, buf, sizeof(buf)), sizeof(buf)); 127 128 return (buf); 129 } 130