/* $NetBSD: devname.c,v 1.21 2010/03/23 20:28:59 drochner Exp $ */ /*- * Copyright (c) 2000 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Simon Burge. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /*- * Copyright (c) 1992 Keith Muller. * Copyright (c) 1989, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Keith Muller of the University of California, San Diego. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #if defined(LIBC_SCCS) && !defined(lint) #if 0 static char sccsid[] = "@(#)devname.c 8.2 (Berkeley) 4/29/95"; #else __RCSID("$NetBSD: devname.c,v 1.21 2010/03/23 20:28:59 drochner Exp $"); #endif #endif /* LIBC_SCCS and not lint */ #include "namespace.h" #include #include #include #include #include #include #include #include #include #include #define DEV_SZ 317 /* show be prime for best results */ #define VALID 1 /* entry and devname are valid */ #define INVALID 2 /* entry valid, devname NOT valid */ typedef struct devc { int valid; /* entry valid? */ dev_t dev; /* cached device */ mode_t type; /* cached file type */ char name[NAME_MAX]; /* device name */ } DEVC; char * devname(dev, type) dev_t dev; mode_t type; { struct { mode_t type; dev_t dev; } bkey; struct { mode_t type; int32_t dev; } obkey; static DB *db; static int failure; DBT data, key; DEVC *ptr, **pptr; static DEVC **devtb = NULL; static devmajor_t pts; static int pts_valid = 0; if (!db && !failure && !(db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL))) { warn("warning: %s", _PATH_DEVDB); failure = 1; } /* initialise dev cache */ if (!failure && devtb == NULL) { devtb = calloc(DEV_SZ, sizeof(DEVC *)); if (devtb == NULL) failure= 1; } if (failure) return (NULL); /* see if we have this dev/type cached */ pptr = devtb + (size_t)((dev + type) % DEV_SZ); ptr = *pptr; if (ptr && ptr->valid > 0 && ptr->dev == dev && ptr->type == type) { if (ptr->valid == VALID) return (ptr->name); return (NULL); } if (ptr == NULL) *pptr = ptr = malloc(sizeof(DEVC)); /* * Keys are a mode_t followed by a dev_t. The former is the type of * the file (mode & S_IFMT), the latter is the st_rdev field. Be * sure to clear any padding that may be found in bkey. */ (void)memset(&bkey, 0, sizeof(bkey)); bkey.dev = dev; bkey.type = type; key.data = &bkey; key.size = sizeof(bkey); if ((db->get)(db, &key, &data, 0) == 0) { found_it: if (ptr == NULL) return (char *)data.data; ptr->dev = dev; ptr->type = type; strncpy(ptr->name, (char *)data.data, NAME_MAX); ptr->name[NAME_MAX - 1] = '\0'; ptr->valid = VALID; } else { /* Look for a 32 bit dev_t. */ (void)memset(&obkey, 0, sizeof(obkey)); obkey.dev = (int32_t)(uint32_t)dev; obkey.type = type; key.data = &obkey; key.size = sizeof(obkey); if ((db->get)(db, &key, &data, 0) == 0) goto found_it; if (ptr == NULL) return (NULL); ptr->valid = INVALID; if (type == S_IFCHR) { if (!pts_valid) { pts = getdevmajor("pts", S_IFCHR); pts_valid = 1; } if (pts != NODEVMAJOR && major(dev) == pts) { (void)snprintf(ptr->name, sizeof(ptr->name), "%s%d", _PATH_DEV_PTS + sizeof(_PATH_DEV) - 1, minor(dev)); ptr->valid = VALID; } } ptr->dev = dev; ptr->type = type; } if (ptr->valid == VALID) return (ptr->name); else return (NULL); }