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/* SPDX-License-Identifier: LGPL-2.1+ */
/***
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 <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <sys/xattr.h>
#include "alloc-util.h"
#include "fd-util.h"
#include "macro.h"
#include "sparse-endian.h"
#include "stdio-util.h"
#include "time-util.h"
#include "xattr-util.h"
int getxattr_malloc(const char *path, const char *name, char **value, bool allow_symlink) {
char *v;
size_t l;
ssize_t n;
assert(path);
assert(name);
assert(value);
for (l = 100; ; l = (size_t) n + 1) {
v = new0(char, l);
if (!v)
return -ENOMEM;
if (allow_symlink)
n = lgetxattr(path, name, v, l);
else
n = getxattr(path, name, v, l);
if (n >= 0 && (size_t) n < l) {
*value = v;
return n;
}
free(v);
if (n < 0 && errno != ERANGE)
return -errno;
if (allow_symlink)
n = lgetxattr(path, name, NULL, 0);
else
n = getxattr(path, name, NULL, 0);
if (n < 0)
return -errno;
}
}
int fgetxattr_malloc(int fd, const char *name, char **value) {
char *v;
size_t l;
ssize_t n;
assert(fd >= 0);
assert(name);
assert(value);
for (l = 100; ; l = (size_t) n + 1) {
v = new0(char, l);
if (!v)
return -ENOMEM;
n = fgetxattr(fd, name, v, l);
if (n >= 0 && (size_t) n < l) {
*value = v;
return n;
}
free(v);
if (n < 0 && errno != ERANGE)
return -errno;
n = fgetxattr(fd, name, NULL, 0);
if (n < 0)
return -errno;
}
}
ssize_t fgetxattrat_fake(int dirfd, const char *filename, const char *attribute, void *value, size_t size, int flags) {
char fn[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int) + 1];
_cleanup_close_ int fd = -1;
ssize_t l;
/* The kernel doesn't have a fgetxattrat() command, hence let's emulate one */
fd = openat(dirfd, filename, O_CLOEXEC|O_PATH|(flags & AT_SYMLINK_NOFOLLOW ? O_NOFOLLOW : 0));
if (fd < 0)
return -errno;
xsprintf(fn, "/proc/self/fd/%i", fd);
l = getxattr(fn, attribute, value, size);
if (l < 0)
return -errno;
return l;
}
static int parse_crtime(le64_t le, usec_t *usec) {
uint64_t u;
assert(usec);
u = le64toh(le);
if (IN_SET(u, 0, (uint64_t) -1))
return -EIO;
*usec = (usec_t) u;
return 0;
}
int fd_getcrtime(int fd, usec_t *usec) {
le64_t le;
ssize_t n;
assert(fd >= 0);
assert(usec);
/* Until Linux gets a real concept of birthtime/creation time,
* let's fake one with xattrs */
n = fgetxattr(fd, "user.crtime_usec", &le, sizeof(le));
if (n < 0)
return -errno;
if (n != sizeof(le))
return -EIO;
return parse_crtime(le, usec);
}
int fd_getcrtime_at(int dirfd, const char *name, usec_t *usec, int flags) {
le64_t le;
ssize_t n;
n = fgetxattrat_fake(dirfd, name, "user.crtime_usec", &le, sizeof(le), flags);
if (n < 0)
return -errno;
if (n != sizeof(le))
return -EIO;
return parse_crtime(le, usec);
}
int path_getcrtime(const char *p, usec_t *usec) {
le64_t le;
ssize_t n;
assert(p);
assert(usec);
n = getxattr(p, "user.crtime_usec", &le, sizeof(le));
if (n < 0)
return -errno;
if (n != sizeof(le))
return -EIO;
return parse_crtime(le, usec);
}
int fd_setcrtime(int fd, usec_t usec) {
le64_t le;
assert(fd >= 0);
if (usec <= 0)
usec = now(CLOCK_REALTIME);
le = htole64((uint64_t) usec);
if (fsetxattr(fd, "user.crtime_usec", &le, sizeof(le), 0) < 0)
return -errno;
return 0;
}
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