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/***
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 "systemd-basic/chattr-util.h"
#include "systemd-basic/fd-util.h"
#include "systemd-basic/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);
}
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