/* * Copyright 2000 Massachusetts Institute of Technology * * Permission to use, copy, modify, and distribute this software and * its documentation for any purpose and without fee is hereby * granted, provided that both the above copyright notice and this * permission notice appear in all copies, that both the above * copyright notice and this permission notice appear in all * supporting documentation, and that the name of M.I.T. not be used * in advertising or publicity pertaining to distribution of the * software without specific, written prior permission. M.I.T. makes * no representations about the suitability of this software for any * purpose. It is provided "as is" without express or implied * warranty. * * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''. M.I.T. DISCLAIMS * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE, * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT * SHALL M.I.T. 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. * * $FreeBSD: src/lib/libc/gen/posixshm.c,v 1.2.2.1 2000/08/22 01:48:12 jhb Exp $ */ #include "namespace.h" #include #include #include #include #include #include #include #include #include "un-namespace.h" static int mkintermediatedirs(int dfd, const char *path); int shm_open(const char *path, int flags, mode_t mode) { int dfd; int fd; struct stat stab; if ((flags & O_ACCMODE) == O_WRONLY) { errno = EINVAL; return (-1); } while (*path == '/') ++path; /* * Expect a tmpfs filesystem for our shm base. If for some reason * it does not exist (it really should), fall-back to /tmp. */ dfd = _open("/var/run/shm", O_RDONLY|O_DIRECTORY); if (dfd < 0) dfd = _open("/tmp", O_RDONLY|O_DIRECTORY); if (dfd >= 0) { fd = _openat(dfd, path, flags, mode); if (fd < 0 && errno == ENOENT && mkintermediatedirs(dfd, path) == 0) { fd = _openat(dfd, path, flags, mode); } _close(dfd); } else { fd = -1; } if (fd != -1) { if (_fstat(fd, &stab) != 0 || !S_ISREG(stab.st_mode)) { _close(fd); errno = EINVAL; return (-1); } if (_fcntl(fd, F_SETFD, FD_CLOEXEC) != 0 || _fcntl(fd, F_SETFL, (int)FPOSIXSHM) != 0) { _close(fd); return (-1); } } return (fd); } int shm_unlink(const char *path) { int res; int dfd; while (*path == '/') ++path; /* * Expect a tmpfs filesystem for our shm base. If for some reason * it does not exist (it really should), fall-back to /tmp. */ dfd = _open("/var/run/shm", O_RDONLY|O_DIRECTORY); if (dfd < 0) dfd = _open("/tmp", O_RDONLY|O_DIRECTORY); if (dfd >= 0) { res = _unlinkat(dfd, path, 0); _close(dfd); } else { res = -1; } return res; } /* * Create any missing intermediate directories, modes 1777 */ static int mkintermediatedirs(int dfd, const char *path) { const char *eptr; char buf[PATH_MAX+1]; size_t len; int res = 0; eptr = path - 1; while ((eptr = strchr(eptr + 1, '/')) != NULL) { len = eptr - path; if (len > PATH_MAX) { errno = EINVAL; return -1; } bcopy(path, buf, len); buf[len] = 0; res = _mkdirat(dfd, buf, 01777); if (res < 0 && errno != EEXIST) break; } return res; }