1 /* $NetBSD: getdiskrawname.c,v 1.5 2014/09/17 23:54:42 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 2012 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Christos Zoulas. 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 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 #include <sys/cdefs.h> 32 __RCSID("$NetBSD: getdiskrawname.c,v 1.5 2014/09/17 23:54:42 christos Exp $"); 33 34 #include <sys/stat.h> 35 36 #include <stdio.h> 37 #include <string.h> 38 #include <errno.h> 39 #include <util.h> 40 #include <limits.h> 41 #include <unistd.h> 42 43 static const char * 44 resolve_link(char *buf, size_t bufsiz, const char *name) 45 { 46 const char *dp; 47 size_t nlen; 48 ssize_t dlen; 49 50 dlen = readlink(name, buf, bufsiz - 1); 51 if (dlen == -1) 52 return name; 53 54 buf[dlen] = '\0'; 55 56 if (buf[0] != '/') { 57 dp = strrchr(name, '/'); 58 if (dp != NULL) { 59 nlen = dp - name + 1; 60 if (nlen + 1 > bufsiz) 61 return NULL; 62 if (nlen + dlen + 1 > bufsiz) 63 return NULL; 64 65 memmove(buf + nlen, buf, (size_t)dlen + 1); 66 memcpy(buf, name, nlen); 67 } 68 } 69 70 return buf; 71 } 72 73 const char * 74 getdiskrawname(char *buf, size_t bufsiz, const char *name) 75 { 76 const char *dp; 77 struct stat st; 78 char dest[PATH_MAX]; 79 80 if ((name = resolve_link(dest, sizeof(dest), name)) == NULL) { 81 errno = EINVAL; 82 return NULL; 83 } 84 85 dp = strrchr(name, '/'); 86 87 if (stat(name, &st) == -1) 88 return NULL; 89 90 if (!S_ISBLK(st.st_mode)) { 91 errno = EFTYPE; 92 return NULL; 93 } 94 95 if (dp != NULL) 96 (void)snprintf(buf, bufsiz, "%.*s/r%s", (int)(dp - name), name, dp + 1); 97 else 98 (void)snprintf(buf, bufsiz, "r%s", name); 99 100 return buf; 101 } 102 103 const char * 104 getdiskcookedname(char *buf, size_t bufsiz, const char *name) 105 { 106 const char *dp; 107 struct stat st; 108 char dest[PATH_MAX]; 109 110 if ((name = resolve_link(dest, sizeof(dest), name)) == NULL) { 111 errno = EINVAL; 112 return NULL; 113 } 114 115 dp = strrchr(name, '/'); 116 117 if ((dp != NULL && dp[1] != 'r') || (dp == NULL && name[0] != 'r')) { 118 errno = EINVAL; 119 return NULL; 120 } 121 122 if (stat(name, &st) == -1) 123 return NULL; 124 125 if (!S_ISCHR(st.st_mode)) { 126 errno = EFTYPE; 127 return NULL; 128 } 129 130 if (dp != NULL) 131 (void)snprintf(buf, bufsiz, "%.*s/%s", (int)(dp - name), name, dp + 2); 132 else 133 (void)snprintf(buf, bufsiz, "%s", name + 1); 134 135 return buf; 136 } 137