1 /* $OpenBSD: opendev.c,v 1.8 2004/05/28 07:03:47 deraadt Exp $ */ 2 3 /* 4 * Copyright (c) 2000, Todd C. Miller. All rights reserved. 5 * Copyright (c) 1996, Jason Downs. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS 17 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 19 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, 20 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 22 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 23 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <errno.h> 30 #include <fcntl.h> 31 #include <limits.h> 32 #include <paths.h> 33 #include <stdio.h> 34 #include <string.h> 35 36 #include "util.h" 37 38 /* 39 * This routine is a generic rewrite of the original code found in 40 * disklabel(8). 41 */ 42 43 int 44 opendev(char *path, int oflags, int dflags, char **realpath) 45 { 46 static char namebuf[PATH_MAX]; 47 char *slash, *prefix; 48 int fd; 49 50 /* Initial state */ 51 if (realpath) 52 *realpath = path; 53 fd = -1; 54 errno = ENOENT; 55 56 if (dflags & OPENDEV_BLCK) 57 prefix = ""; /* block device */ 58 else 59 prefix = "r"; /* character device */ 60 61 if ((slash = strchr(path, '/'))) 62 fd = open(path, oflags); 63 else if (dflags & OPENDEV_PART) { 64 /* 65 * First try raw partition (for removable drives) 66 */ 67 if (snprintf(namebuf, sizeof(namebuf), "%s%s%s%c", 68 _PATH_DEV, prefix, path, 'a' + getrawpartition()) 69 < sizeof(namebuf)) { 70 fd = open(namebuf, oflags); 71 if (realpath) 72 *realpath = namebuf; 73 } else 74 errno = ENAMETOOLONG; 75 } 76 if (!slash && fd == -1 && errno == ENOENT) { 77 if (snprintf(namebuf, sizeof(namebuf), "%s%s%s", 78 _PATH_DEV, prefix, path) < sizeof(namebuf)) { 79 fd = open(namebuf, oflags); 80 if (realpath) 81 *realpath = namebuf; 82 } else 83 errno = ENAMETOOLONG; 84 } 85 return (fd); 86 } 87