| 1 | /* |
| 2 | * Copyright (c) 2000, Todd C. Miller. All rights reserved. |
| 3 | * Copyright (c) 1996, Jason Downs. All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in the |
| 12 | * documentation and/or other materials provided with the distribution. |
| 13 | * |
| 14 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS |
| 15 | * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| 16 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| 17 | * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, |
| 18 | * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| 19 | * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
| 20 | * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| 21 | * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 22 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 23 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 24 | * SUCH DAMAGE. |
| 25 | */ |
| 26 | |
| 27 | #include <ctype.h> |
| 28 | #include <errno.h> |
| 29 | #include <fcntl.h> |
| 30 | #include <limits.h> |
| 31 | #include <paths.h> |
| 32 | #include <stdio.h> |
| 33 | #include <string.h> |
| 34 | #include <pthread.h> |
| 35 | |
| 36 | #include "util.h" |
| 37 | |
| 38 | /* |
| 39 | * opendev(3) is an inherently non-thread-safe API, since |
| 40 | * it returns a buffer to global storage. However we can |
| 41 | * at least make sure the storage allocation is thread safe |
| 42 | * and does not leak memory in case of simultaneous |
| 43 | * initialization |
| 44 | */ |
| 45 | static pthread_once_t opendev_namebuf_once = PTHREAD_ONCE_INIT; |
| 46 | static char *namebuf = NULL; |
| 47 | |
| 48 | static void opendev_namebuf_init(void); |
| 49 | |
| 50 | int |
| 51 | opendev(path, oflags, dflags, realpath) |
| 52 | char *path; |
| 53 | int oflags; |
| 54 | int dflags; |
| 55 | char **realpath; |
| 56 | { |
| 57 | int fd; |
| 58 | char *slash, *prefix; |
| 59 | |
| 60 | /* Initial state */ |
| 61 | if (realpath) |
| 62 | *realpath = path; |
| 63 | fd = -1; |
| 64 | errno = ENOENT; |
| 65 | |
| 66 | if (pthread_once(&opendev_namebuf_once, |
| 67 | opendev_namebuf_init) |
| 68 | || !namebuf) { |
| 69 | errno = ENOMEM; |
| 70 | return -1; |
| 71 | } |
| 72 | |
| 73 | if (dflags & OPENDEV_BLCK) |
| 74 | prefix = ""; /* block device */ |
| 75 | else |
| 76 | prefix = "r"; /* character device */ |
| 77 | |
| 78 | if ((slash = strchr(path, '/'))) |
| 79 | fd = open(path, oflags); |
| 80 | else if (dflags & OPENDEV_PART) { |
| 81 | if (snprintf(namebuf, PATH_MAX, "%s%s%s", |
| 82 | _PATH_DEV, prefix, path) < PATH_MAX) { |
| 83 | char *slice; |
| 84 | while ((slice = strrchr(namebuf, 's')) && |
| 85 | isdigit(*(slice-1))) *slice = '\0'; |
| 86 | fd = open(namebuf, oflags); |
| 87 | if (realpath) |
| 88 | *realpath = namebuf; |
| 89 | } else |
| 90 | errno = ENAMETOOLONG; |
| 91 | } |
| 92 | if (!slash && fd == -1 && errno == ENOENT) { |
| 93 | if (snprintf(namebuf, PATH_MAX, "%s%s%s", |
| 94 | _PATH_DEV, prefix, path) < PATH_MAX) { |
| 95 | fd = open(namebuf, oflags); |
| 96 | if (realpath) |
| 97 | *realpath = namebuf; |
| 98 | } else |
| 99 | errno = ENAMETOOLONG; |
| 100 | } |
| 101 | return (fd); |
| 102 | } |
| 103 | |
| 104 | static void opendev_namebuf_init(void) |
| 105 | { |
| 106 | namebuf = malloc(PATH_MAX); |
| 107 | } |