/*** This file is part of systemd. Copyright 2010 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <errno.h> #include <fcntl.h> #include <sys/ioctl.h> #include <sys/stat.h> #include <linux/fs.h> #include "chattr-util.h" #include "fd-util.h" #include "macro.h" int chattr_fd(int fd, unsigned value, unsigned mask) { unsigned old_attr, new_attr; struct stat st; assert(fd >= 0); if (fstat(fd, &st) < 0) return -errno; /* Explicitly check whether this is a regular file or * directory. If it is anything else (such as a device node or * fifo), then the ioctl will not hit the file systems but * possibly drivers, where the ioctl might have different * effects. Notably, DRM is using the same ioctl() number. */ if (!S_ISDIR(st.st_mode) && !S_ISREG(st.st_mode)) return -ENOTTY; if (mask == 0) return 0; if (ioctl(fd, FS_IOC_GETFLAGS, &old_attr) < 0) return -errno; new_attr = (old_attr & ~mask) | (value & mask); if (new_attr == old_attr) return 0; if (ioctl(fd, FS_IOC_SETFLAGS, &new_attr) < 0) return -errno; return 1; } int chattr_path(const char *p, unsigned value, unsigned mask) { _cleanup_close_ int fd = -1; assert(p); if (mask == 0) return 0; fd = open(p, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW); if (fd < 0) return -errno; return chattr_fd(fd, value, mask); } int read_attr_fd(int fd, unsigned *ret) { struct stat st; assert(fd >= 0); if (fstat(fd, &st) < 0) return -errno; if (!S_ISDIR(st.st_mode) && !S_ISREG(st.st_mode)) return -ENOTTY; if (ioctl(fd, FS_IOC_GETFLAGS, ret) < 0) return -errno; return 0; } int read_attr_path(const char *p, unsigned *ret) { _cleanup_close_ int fd = -1; assert(p); assert(ret); fd = open(p, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW); if (fd < 0) return -errno; return read_attr_fd(fd, ret); }