devname.c revision 1.10
1 /* $NetBSD: devname.c,v 1.10 2003/08/07 16:42:47 agc Exp $ */ 2 3 /*- 4 * Copyright (c) 2000 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Simon Burge. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 /*- 40 * Copyright (c) 1989, 1993 41 * The Regents of the University of California. All rights reserved. 42 * 43 * This code is derived from software contributed to Berkeley by 44 * Keith Muller of the University of California, San Diego. 45 * 46 * Redistribution and use in source and binary forms, with or without 47 * modification, are permitted provided that the following conditions 48 * are met: 49 * 1. Redistributions of source code must retain the above copyright 50 * notice, this list of conditions and the following disclaimer. 51 * 2. Redistributions in binary form must reproduce the above copyright 52 * notice, this list of conditions and the following disclaimer in the 53 * documentation and/or other materials provided with the distribution. 54 * 3. Neither the name of the University nor the names of its contributors 55 * may be used to endorse or promote products derived from this software 56 * without specific prior written permission. 57 * 58 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 59 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 60 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 61 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 62 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 63 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 64 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 65 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 66 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 67 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 68 * SUCH DAMAGE. 69 */ 70 71 /*- 72 * Copyright (c) 1992 Keith Muller. 73 * 74 * This code is derived from software contributed to Berkeley by 75 * Keith Muller of the University of California, San Diego. 76 * 77 * Redistribution and use in source and binary forms, with or without 78 * modification, are permitted provided that the following conditions 79 * are met: 80 * 1. Redistributions of source code must retain the above copyright 81 * notice, this list of conditions and the following disclaimer. 82 * 2. Redistributions in binary form must reproduce the above copyright 83 * notice, this list of conditions and the following disclaimer in the 84 * documentation and/or other materials provided with the distribution. 85 * 3. All advertising materials mentioning features or use of this software 86 * must display the following acknowledgement: 87 * This product includes software developed by the University of 88 * California, Berkeley and its contributors. 89 * 4. Neither the name of the University nor the names of its contributors 90 * may be used to endorse or promote products derived from this software 91 * without specific prior written permission. 92 * 93 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 94 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 95 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 96 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 97 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 98 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 99 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 100 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 101 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 102 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 103 * SUCH DAMAGE. 104 */ 105 106 #include <sys/cdefs.h> 107 #if defined(LIBC_SCCS) && !defined(lint) 108 #if 0 109 static char sccsid[] = "@(#)devname.c 8.2 (Berkeley) 4/29/95"; 110 #else 111 __RCSID("$NetBSD: devname.c,v 1.10 2003/08/07 16:42:47 agc Exp $"); 112 #endif 113 #endif /* LIBC_SCCS and not lint */ 114 115 #include "namespace.h" 116 #include <sys/types.h> 117 118 #include <db.h> 119 #include <fcntl.h> 120 #include <paths.h> 121 #include <stdio.h> 122 #include <string.h> 123 #include <stdlib.h> 124 #include <err.h> 125 126 #ifdef __weak_alias 127 __weak_alias(devname,_devname) 128 #endif 129 130 #define DEV_SZ 317 /* show be prime for best results */ 131 #define VALID 1 /* entry and devname are valid */ 132 #define INVALID 2 /* entry valid, devname NOT valid */ 133 134 typedef struct devc { 135 int valid; /* entry valid? */ 136 dev_t dev; /* cached device */ 137 mode_t type; /* cached file type */ 138 char name[NAME_MAX]; /* device name */ 139 } DEVC; 140 141 char * 142 devname(dev, type) 143 dev_t dev; 144 mode_t type; 145 { 146 struct { 147 mode_t type; 148 dev_t dev; 149 } bkey; 150 static DB *db; 151 static int failure; 152 DBT data, key; 153 DEVC *ptr, **pptr; 154 static DEVC **devtb = NULL; 155 156 if (!db && !failure && 157 !(db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL))) { 158 warn("warning: %s", _PATH_DEVDB); 159 failure = 1; 160 } 161 /* initialise dev cache */ 162 if (!failure && devtb == NULL) { 163 devtb = (DEVC **)calloc(DEV_SZ, sizeof(DEVC *)); 164 if (devtb == NULL) 165 failure= 1; 166 } 167 if (failure) 168 return (NULL); 169 170 /* see if we have this dev/type cached */ 171 pptr = devtb + ((dev + type) % DEV_SZ); 172 ptr = *pptr; 173 174 if (ptr && ptr->valid > 0 && ptr->dev == dev && ptr->type == type) { 175 if (ptr->valid == VALID) 176 return (ptr->name); 177 return (NULL); 178 } 179 180 if (ptr == NULL) 181 *pptr = ptr = (DEVC *)malloc(sizeof(DEVC)); 182 183 /* 184 * Keys are a mode_t followed by a dev_t. The former is the type of 185 * the file (mode & S_IFMT), the latter is the st_rdev field. Be 186 * sure to clear any padding that may be found in bkey. 187 */ 188 memset(&bkey, 0, sizeof(bkey)); 189 bkey.dev = dev; 190 bkey.type = type; 191 key.data = &bkey; 192 key.size = sizeof(bkey); 193 if ((db->get)(db, &key, &data, 0) == 0) { 194 if (ptr == NULL) 195 return (char *)data.data; 196 ptr->dev = dev; 197 ptr->type = type; 198 strncpy(ptr->name, (char *)data.data, NAME_MAX); 199 ptr->name[NAME_MAX - 1] = '\0'; 200 ptr->valid = VALID; 201 return (ptr->name); 202 } else { 203 if (ptr == NULL) 204 return (NULL); 205 ptr->dev = dev; 206 ptr->type = type; 207 ptr->valid = INVALID; 208 return (NULL); 209 } 210 } 211
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