devname.c revision 65955
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. 3265632Sphk * 3365632Sphk * $FreeBSD: head/lib/libc/gen/devname.c 65955 2000-09-16 21:58:53Z phk $ 341573Srgrimes */ 351573Srgrimes 361573Srgrimes#if defined(LIBC_SCCS) && !defined(lint) 3723658Speterstatic char sccsid[] = "@(#)devname.c 8.2 (Berkeley) 4/29/95"; 381573Srgrimes#endif /* LIBC_SCCS and not lint */ 391573Srgrimes 401573Srgrimes#include <sys/types.h> 4165632Sphk#include <sys/sysctl.h> 421573Srgrimes 431573Srgrimes#include <db.h> 441573Srgrimes#include <err.h> 451573Srgrimes#include <errno.h> 461573Srgrimes#include <fcntl.h> 471573Srgrimes#include <paths.h> 481573Srgrimes#include <stdio.h> 491573Srgrimes#include <string.h> 5065955Sphk#include <sys/param.h> 5148882Sphk#include <sys/stat.h> 521573Srgrimes 5348882Sphkstatic char * 5448882Sphkxdevname(dev, type) 551573Srgrimes dev_t dev; 561573Srgrimes mode_t type; 571573Srgrimes{ 581573Srgrimes struct { 591573Srgrimes mode_t type; 601573Srgrimes dev_t dev; 611573Srgrimes } bkey; 621573Srgrimes static DB *db; 631573Srgrimes static int failure; 641573Srgrimes DBT data, key; 651573Srgrimes 661573Srgrimes if (!db && !failure && 6765955Sphk !(db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL))) 681573Srgrimes failure = 1; 691573Srgrimes if (failure) 7023658Speter return (NULL); 711573Srgrimes 721573Srgrimes /* 731573Srgrimes * Keys are a mode_t followed by a dev_t. The former is the type of 741573Srgrimes * the file (mode & S_IFMT), the latter is the st_rdev field. Be 751573Srgrimes * sure to clear any padding that may be found in bkey. 761573Srgrimes */ 771573Srgrimes memset(&bkey, 0, sizeof(bkey)); 781573Srgrimes bkey.dev = dev; 791573Srgrimes bkey.type = type; 801573Srgrimes key.data = &bkey; 811573Srgrimes key.size = sizeof(bkey); 8223658Speter return ((db->get)(db, &key, &data, 0) ? NULL : (char *)data.data); 831573Srgrimes} 8448882Sphk 8548882Sphkchar * 8648882Sphkdevname(dev, type) 8748882Sphk dev_t dev; 8848882Sphk mode_t type; 8948882Sphk{ 9065955Sphk static char buf[SPECNAMELEN + 1]; 9165632Sphk int i, 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