/* * Copyright (c) 2000, Todd C. Miller. All rights reserved. * Copyright (c) 1996, Jason Downs. All rights reserved. * * 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 AUTHOR(S) ``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 AUTHOR(S) 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 <ctype.h> #include <errno.h> #include <fcntl.h> #include <limits.h> #include <paths.h> #include <stdio.h> #include <string.h> #include <pthread.h> #include "util.h" /* * opendev(3) is an inherently non-thread-safe API, since * it returns a buffer to global storage. However we can * at least make sure the storage allocation is thread safe * and does not leak memory in case of simultaneous * initialization */ static pthread_once_t opendev_namebuf_once = PTHREAD_ONCE_INIT; static char *namebuf = NULL; static void opendev_namebuf_init(void); int opendev(path, oflags, dflags, realpath) char *path; int oflags; int dflags; char **realpath; { int fd; char *slash, *prefix; /* Initial state */ if (realpath) *realpath = path; fd = -1; errno = ENOENT; if (pthread_once(&opendev_namebuf_once, opendev_namebuf_init) || !namebuf) { errno = ENOMEM; return -1; } if (dflags & OPENDEV_BLCK) prefix = ""; /* block device */ else prefix = "r"; /* character device */ if ((slash = strchr(path, '/'))) fd = open(path, oflags); else if (dflags & OPENDEV_PART) { if (snprintf(namebuf, PATH_MAX, "%s%s%s", _PATH_DEV, prefix, path) < PATH_MAX) { char *slice; while ((slice = strrchr(namebuf, 's')) && isdigit(*(slice-1))) *slice = '\0'; fd = open(namebuf, oflags); if (realpath) *realpath = namebuf; } else errno = ENAMETOOLONG; } if (!slash && fd == -1 && errno == ENOENT) { if (snprintf(namebuf, PATH_MAX, "%s%s%s", _PATH_DEV, prefix, path) < PATH_MAX) { fd = open(namebuf, oflags); if (realpath) *realpath = namebuf; } else errno = ENAMETOOLONG; } return (fd); } static void opendev_namebuf_init(void) { namebuf = malloc(PATH_MAX); }