devname.c revision 90039
11573Srgrimes/* 21573Srgrimes * Copyright (c) 1989, 1993 31573Srgrimes * The Regents of the University of California. All rights reserved. 41573Srgrimes * 51573Srgrimes * Redistribution and use in source and binary forms, with or without 61573Srgrimes * modification, are permitted provided that the following conditions 71573Srgrimes * are met: 81573Srgrimes * 1. Redistributions of source code must retain the above copyright 91573Srgrimes * notice, this list of conditions and the following disclaimer. 101573Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 111573Srgrimes * notice, this list of conditions and the following disclaimer in the 121573Srgrimes * documentation and/or other materials provided with the distribution. 131573Srgrimes * 3. All advertising materials mentioning features or use of this software 141573Srgrimes * must display the following acknowledgement: 151573Srgrimes * This product includes software developed by the University of 161573Srgrimes * California, Berkeley and its contributors. 171573Srgrimes * 4. Neither the name of the University nor the names of its contributors 181573Srgrimes * may be used to endorse or promote products derived from this software 191573Srgrimes * without specific prior written permission. 201573Srgrimes * 211573Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 221573Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 231573Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 241573Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 251573Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 261573Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 271573Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 281573Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 291573Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 301573Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 311573Srgrimes * SUCH DAMAGE. 321573Srgrimes */ 331573Srgrimes 341573Srgrimes#if defined(LIBC_SCCS) && !defined(lint) 3523658Speterstatic char sccsid[] = "@(#)devname.c 8.2 (Berkeley) 4/29/95"; 361573Srgrimes#endif /* LIBC_SCCS and not lint */ 3790039Sobrien#include <sys/cdefs.h> 3890039Sobrien__FBSDID("$FreeBSD: head/lib/libc/gen/devname.c 90039 2002-02-01 00:57:29Z obrien $"); 391573Srgrimes 401573Srgrimes#include <sys/types.h> 4165632Sphk#include <sys/sysctl.h> 421573Srgrimes 431573Srgrimes#include <db.h> 441573Srgrimes#include <err.h> 451573Srgrimes#include <fcntl.h> 461573Srgrimes#include <paths.h> 471573Srgrimes#include <stdio.h> 481573Srgrimes#include <string.h> 4965955Sphk#include <sys/param.h> 5048882Sphk#include <sys/stat.h> 511573Srgrimes 5248882Sphkstatic char * 5348882Sphkxdevname(dev, type) 541573Srgrimes dev_t dev; 551573Srgrimes mode_t type; 561573Srgrimes{ 571573Srgrimes struct { 581573Srgrimes mode_t type; 591573Srgrimes dev_t dev; 601573Srgrimes } bkey; 611573Srgrimes static DB *db; 621573Srgrimes static int failure; 631573Srgrimes DBT data, key; 641573Srgrimes 651573Srgrimes if (!db && !failure && 6665955Sphk !(db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL))) 671573Srgrimes failure = 1; 681573Srgrimes if (failure) 6923658Speter return (NULL); 701573Srgrimes 711573Srgrimes /* 721573Srgrimes * Keys are a mode_t followed by a dev_t. The former is the type of 731573Srgrimes * the file (mode & S_IFMT), the latter is the st_rdev field. Be 741573Srgrimes * sure to clear any padding that may be found in bkey. 751573Srgrimes */ 761573Srgrimes memset(&bkey, 0, sizeof(bkey)); 771573Srgrimes bkey.dev = dev; 781573Srgrimes bkey.type = type; 791573Srgrimes key.data = &bkey; 801573Srgrimes key.size = sizeof(bkey); 8123658Speter return ((db->get)(db, &key, &data, 0) ? NULL : (char *)data.data); 821573Srgrimes} 8348882Sphk 8448882Sphkchar * 8548882Sphkdevname(dev, type) 8648882Sphk dev_t dev; 8748882Sphk mode_t type; 8848882Sphk{ 8965955Sphk static char buf[SPECNAMELEN + 1]; 9080552Stmm int i; 9180552Stmm size_t j; 9248882Sphk char *r; 9348882Sphk 9465632Sphk /* First check the DB file. */ 9548882Sphk r = xdevname(dev, type); 9665632Sphk if (r != NULL) 9765632Sphk return (r); 9865632Sphk 9965632Sphk /* Then ask the kernel. */ 10065632Sphk if ((type & S_IFMT) == S_IFCHR) { 10165632Sphk j = sizeof(buf); 10265632Sphk i = sysctlbyname("kern.devname", buf, &j, &dev, sizeof (dev)); 10365632Sphk if (i == 0) 10465632Sphk return (buf); 10548882Sphk } 10665632Sphk 10765632Sphk /* Finally just format it */ 10865955Sphk if (minor(dev) > 255) 10965955Sphk r = "#%c:%d:0x%x"; 11065955Sphk else 11165955Sphk r = "#%c:%d:0x%d"; 11265955Sphk snprintf(buf, SPECNAMELEN + 1, r, 11365955Sphk (type & S_IFMT) == S_IFCHR ? 'C' : 'B', major(dev), minor(dev)); 11465955Sphk return (buf); 11548882Sphk} 116