diff options
Diffstat (limited to 'src/libbasic/chattr-util.c')
-rw-r--r-- | src/libbasic/chattr-util.c | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/src/libbasic/chattr-util.c b/src/libbasic/chattr-util.c new file mode 100644 index 0000000000..2896a729af --- /dev/null +++ b/src/libbasic/chattr-util.c @@ -0,0 +1,107 @@ +/*** + 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); +} |