#include "time-util.h"
#include "xattr-util.h"
-int getxattr_malloc(
+int getxattr_at_malloc(
+ int fd,
const char *path,
const char *name,
- char **ret,
- bool allow_symlink) {
+ int flags,
+ char **ret) {
+ _cleanup_close_ int opened_fd = -1;
+ unsigned n_attempts = 7;
+ bool by_procfs = false;
size_t l = 100;
- assert(path);
+ assert(fd >= 0 || fd == AT_FDCWD);
assert(name);
+ assert((flags & ~(AT_SYMLINK_FOLLOW|AT_EMPTY_PATH)) == 0);
assert(ret);
- for(;;) {
- _cleanup_free_ char *v = NULL;
- ssize_t n;
-
- v = new0(char, l+1);
- if (!v)
- return -ENOMEM;
+ /* So, this is single function that does what getxattr()/lgetxattr()/fgetxattr() does, but in one go,
+ * and with additional bells and whistles. Specifically:
+ *
+ * 1. This works on O_PATH fds (which fgetxattr() does not)
+ * 2. Provides full openat()-style semantics, i.e. by-fd, by-path and combination thereof
+ * 3. As extension to openat()-style semantics implies AT_EMPTY_PATH if path is NULL.
+ * 4. Does a malloc() loop, automatically sizing the allocation
+ * 5. NUL-terminates the returned buffer (for safety)
+ */
+
+ if (!path) /* If path is NULL, imply AT_EMPTY_PATH. – But if it's "", don't — for safety reasons. */
+ flags |= AT_EMPTY_PATH;
+
+ if (isempty(path)) {
+ if (!FLAGS_SET(flags, AT_EMPTY_PATH))
+ return -EINVAL;
- if (allow_symlink)
- n = lgetxattr(path, name, v, l);
+ if (fd == AT_FDCWD) /* Both unspecified? Then operate on current working directory */
+ path = ".";
else
- n = getxattr(path, name, v, l);
- if (n < 0) {
- if (errno != ERANGE)
- return -errno;
- } else {
- v[n] = 0; /* NUL terminate */
- *ret = TAKE_PTR(v);
- return (int) n;
- }
+ path = NULL;
- if (allow_symlink)
- n = lgetxattr(path, name, NULL, 0);
- else
- n = getxattr(path, name, NULL, 0);
- if (n < 0)
+ } else if (fd != AT_FDCWD) {
+
+ /* If both have been specified, then we go via O_PATH */
+ opened_fd = openat(fd, path, O_PATH|O_CLOEXEC|(FLAGS_SET(flags, AT_SYMLINK_FOLLOW) ? 0 : O_NOFOLLOW));
+ if (opened_fd < 0)
return -errno;
- if (n > INT_MAX) /* We couldn't return this as 'int' anymore */
- return -E2BIG;
- l = (size_t) n;
+ fd = opened_fd;
+ path = NULL;
+ by_procfs = true; /* fgetxattr() is not going to work, go via /proc/ link right-away */
}
-}
-int fgetxattr_malloc(
- int fd,
- const char *name,
- char **ret) {
-
- size_t l = 100;
-
- assert(fd >= 0);
- assert(name);
- assert(ret);
-
- for (;;) {
+ for(;;) {
_cleanup_free_ char *v = NULL;
ssize_t n;
- v = new(char, l+1);
+ if (n_attempts == 0) /* If someone is racing against us, give up eventually */
+ return -EBUSY;
+ n_attempts--;
+
+ v = new0(char, l+1);
if (!v)
return -ENOMEM;
- n = fgetxattr(fd, name, v, l);
+ l = MALLOC_ELEMENTSOF(v) - 1;
+
+ if (path)
+ n = FLAGS_SET(flags, AT_SYMLINK_FOLLOW) ? getxattr(path, name, v, l) : lgetxattr(path, name, v, l);
+ else
+ n = by_procfs ? getxattr(FORMAT_PROC_FD_PATH(fd), name, v, l) : fgetxattr(fd, name, v, l);
if (n < 0) {
+ if (errno == EBADF) {
+ if (by_procfs || path)
+ return -EBADF;
+
+ by_procfs = true; /* Might be an O_PATH fd, try again via /proc/ link */
+ continue;
+ }
+
if (errno != ERANGE)
return -errno;
} else {
return (int) n;
}
- n = fgetxattr(fd, name, NULL, 0);
+ if (path)
+ n = FLAGS_SET(flags, AT_SYMLINK_FOLLOW) ? getxattr(path, name, NULL, 0) : lgetxattr(path, name, NULL, 0);
+ else
+ n = by_procfs ? getxattr(FORMAT_PROC_FD_PATH(fd), name, NULL, 0) : fgetxattr(fd, name, NULL, 0);
if (n < 0)
return -errno;
if (n > INT_MAX) /* We couldn't return this as 'int' anymore */
}
}
-/* Note: ret_fn should already be allocated for the usual xsprintf and /proc/self/fd/%i pattern. */
-static int getxattrat_fake_prepare(
- int dirfd,
- const char *filename,
- int flags,
- char ret_fn[static PROC_FD_PATH_MAX],
- int *ret_fd) {
-
- _cleanup_close_ int fd = -1;
- assert(ret_fn);
- assert(ret_fd);
-
- /* The kernel doesn't have a fgetxattrat() command, hence let's emulate one */
-
- if (flags & ~(AT_SYMLINK_NOFOLLOW|AT_EMPTY_PATH))
- return -EINVAL;
-
- if (isempty(filename)) {
- if (!(flags & AT_EMPTY_PATH))
- return -EINVAL;
-
- assert(dirfd >= 0);
-
- format_proc_fd_path(ret_fn, dirfd);
- } else {
- fd = openat(dirfd, filename, O_CLOEXEC|O_PATH|(flags & AT_SYMLINK_NOFOLLOW ? O_NOFOLLOW : 0));
- if (fd < 0)
- return -errno;
-
- format_proc_fd_path(ret_fn, fd);
- }
-
- /* Pass the FD to the caller, since in case we do openat() the filename depends on it. */
- *ret_fd = TAKE_FD(fd);
-
- return 0;
-}
-
-int fgetxattrat_fake(
- int dirfd,
- const char *filename,
- const char *attribute,
- void *value, size_t size,
- int flags,
- size_t *ret_size) {
-
- _cleanup_close_ int fd = -1;
- char fn[PROC_FD_PATH_MAX];
- ssize_t l;
- int r;
-
- r = getxattrat_fake_prepare(dirfd, filename, flags, fn, &fd);
- if (r < 0)
- return r;
-
- l = getxattr(fn, attribute, value, size);
- if (l < 0)
- return -errno;
-
- *ret_size = l;
- return 0;
-}
-
-int fgetxattrat_fake_malloc(
- int dirfd,
- const char *filename,
- const char *attribute,
- int flags,
- char **value) {
-
- _cleanup_close_ int fd = -1;
- char fn[PROC_FD_PATH_MAX];
- int r;
-
- r = getxattrat_fake_prepare(dirfd, filename, flags, fn, &fd);
- if (r < 0)
- return r;
-
- return getxattr_malloc(fn, attribute, value, false);
-}
-
static int parse_crtime(le64_t le, usec_t *usec) {
uint64_t u;
return 0;
}
-int fd_getcrtime_at(int dirfd, const char *name, usec_t *ret, int flags) {
+int fd_getcrtime_at(
+ int fd,
+ const char *path,
+ int flags,
+ usec_t *ret) {
+
+ _cleanup_free_ le64_t *le = NULL;
STRUCT_STATX_DEFINE(sx);
usec_t a, b;
- le64_t le;
- size_t n;
int r;
+ assert(fd >= 0 || fd == AT_FDCWD);
+ assert((flags & ~(AT_SYMLINK_FOLLOW|AT_EMPTY_PATH)) == 0);
assert(ret);
- if (flags & ~(AT_EMPTY_PATH|AT_SYMLINK_NOFOLLOW))
- return -EINVAL;
+ if (!path)
+ flags |= AT_EMPTY_PATH;
/* So here's the deal: the creation/birth time (crtime/btime) of a file is a relatively newly supported concept
* on Linux (or more strictly speaking: a concept that only recently got supported in the API, it was
* concept is useful for determining how "old" a file really is, and hence using the older of the two makes
* most sense. */
- if (statx(dirfd, strempty(name), flags|AT_STATX_DONT_SYNC, STATX_BTIME, &sx) >= 0 &&
+ if (statx(fd, strempty(path),
+ (flags & ~AT_SYMLINK_FOLLOW)|(FLAGS_SET(flags, AT_SYMLINK_FOLLOW) ? 0 : AT_SYMLINK_NOFOLLOW)|AT_STATX_DONT_SYNC,
+ STATX_BTIME,
+ &sx) >= 0 &&
(sx.stx_mask & STATX_BTIME) &&
sx.stx_btime.tv_sec != 0)
a = (usec_t) sx.stx_btime.tv_sec * USEC_PER_SEC +
else
a = USEC_INFINITY;
- r = fgetxattrat_fake(dirfd, name, "user.crtime_usec", &le, sizeof(le), flags, &n);
+ r = getxattr_at_malloc(fd, path, "user.crtime_usec", flags, (char**) &le);
if (r >= 0) {
- if (n != sizeof(le))
+ if (r != sizeof(*le))
r = -EIO;
else
- r = parse_crtime(le, &b);
+ r = parse_crtime(*le, &b);
}
if (r < 0) {
if (a != USEC_INFINITY) {
return 0;
}
-int fd_getcrtime(int fd, usec_t *ret) {
- return fd_getcrtime_at(fd, NULL, ret, AT_EMPTY_PATH);
-}
-
int fd_setcrtime(int fd, usec_t usec) {
le64_t le;
return 0;
}
-int flistxattr_malloc(int fd, char **ret) {
+int listxattr_at_malloc(
+ int fd,
+ const char *path,
+ int flags,
+ char **ret) {
+
+ _cleanup_close_ int opened_fd = -1;
+ bool by_procfs = false;
+ unsigned n_attempts = 7;
size_t l = 100;
- assert(fd >= 0);
+ assert(fd >= 0 || fd == AT_FDCWD);
+ assert((flags & ~(AT_SYMLINK_FOLLOW|AT_EMPTY_PATH)) == 0);
assert(ret);
+ /* This is to listxattr()/llistattr()/flistattr() what getxattr_at_malloc() is to getxattr()/… */
+
+ if (!path) /* If path is NULL, imply AT_EMPTY_PATH. – But if it's "", don't. */
+ flags |= AT_EMPTY_PATH;
+
+ if (isempty(path)) {
+ if (!FLAGS_SET(flags, AT_EMPTY_PATH))
+ return -EINVAL;
+
+ if (fd == AT_FDCWD) /* Both unspecified? Then operate on current working directory */
+ path = ".";
+ else
+ path = NULL;
+
+ } else if (fd != AT_FDCWD) {
+ /* If both have been specified, then we go via O_PATH */
+ opened_fd = openat(fd, path, O_PATH|O_CLOEXEC|(FLAGS_SET(flags, AT_SYMLINK_FOLLOW) ? 0 : O_NOFOLLOW));
+ if (opened_fd < 0)
+ return -errno;
+
+ fd = opened_fd;
+ path = NULL;
+ by_procfs = true;
+ }
+
for (;;) {
_cleanup_free_ char *v = NULL;
ssize_t n;
+ if (n_attempts == 0) /* If someone is racing against us, give up eventually */
+ return -EBUSY;
+ n_attempts--;
+
v = new(char, l+1);
if (!v)
return -ENOMEM;
- n = flistxattr(fd, v, l);
+ l = MALLOC_ELEMENTSOF(v) - 1;
+
+ if (path)
+ n = FLAGS_SET(flags, AT_SYMLINK_FOLLOW) ? listxattr(path, v, l) : llistxattr(path, v, l);
+ else
+ n = by_procfs ? listxattr(FORMAT_PROC_FD_PATH(fd), v, l) : flistxattr(fd, v, l);
if (n < 0) {
+ if (errno == EBADF) {
+ if (by_procfs || path)
+ return -EBADF;
+
+ by_procfs = true; /* Might be an O_PATH fd, try again via /proc/ link */
+ continue;
+ }
+
if (errno != ERANGE)
return -errno;
} else {
return (int) n;
}
- n = flistxattr(fd, NULL, 0);
+ if (path)
+ n = FLAGS_SET(flags, AT_SYMLINK_FOLLOW) ? listxattr(path, NULL, 0) : llistxattr(path, NULL, 0);
+ else
+ n = by_procfs ? listxattr(FORMAT_PROC_FD_PATH(fd), NULL, 0) : flistxattr(fd, NULL, 0);
if (n < 0)
return -errno;
if (n > INT_MAX) /* We couldn't return this as 'int' anymore */
#include "time-util.h"
-int getxattr_malloc(const char *path, const char *name, char **value, bool allow_symlink);
-int fgetxattr_malloc(int fd, const char *name, char **value);
-
-int fgetxattrat_fake(
- int dirfd,
- const char *filename,
- const char *attribute,
- void *value, size_t size,
- int flags,
- size_t *ret_size);
-int fgetxattrat_fake_malloc(
- int dirfd,
- const char *filename,
- const char *attribute,
- int flags,
- char **value);
+int getxattr_at_malloc(int fd, const char *path, const char *name, int flags, char **ret);
+static inline int getxattr_malloc(const char *path, const char *name, char **ret) {
+ return getxattr_at_malloc(AT_FDCWD, path, name, AT_SYMLINK_FOLLOW, ret);
+}
+static inline int lgetxattr_malloc(const char *path, const char *name, char **ret) {
+ return getxattr_at_malloc(AT_FDCWD, path, name, 0, ret);
+}
+static inline int fgetxattr_malloc(int fd, const char *name, char **ret) {
+ return getxattr_at_malloc(fd, NULL, name, AT_EMPTY_PATH, ret);
+}
int fd_setcrtime(int fd, usec_t usec);
-int fd_getcrtime(int fd, usec_t *usec);
-int fd_getcrtime_at(int dirfd, const char *name, usec_t *usec, int flags);
+int fd_getcrtime_at(int fd, const char *name, int flags, usec_t *ret);
+static inline int fd_getcrtime(int fd, usec_t *ret) {
+ return fd_getcrtime_at(fd, NULL, 0, ret);
+}
+
-int flistxattr_malloc(int fd, char **ret);
+int listxattr_at_malloc(int fd, const char *path, int flags, char **ret);
+static inline int listxattr_malloc(const char *path, char **ret) {
+ return listxattr_at_malloc(AT_FDCWD, path, AT_SYMLINK_FOLLOW, ret);
+}
+static inline int llistxattr_malloc(const char *path, char **ret) {
+ return listxattr_at_malloc(AT_FDCWD, path, 0, ret);
+}
+static inline int flistxattr_malloc(int fd, char **ret) {
+ return listxattr_at_malloc(fd, NULL, AT_EMPTY_PATH, ret);
+}
#include "tmpfile-util.h"
#include "xattr-util.h"
-static void test_fgetxattrat_fake(void) {
+static void test_getxattr_at_malloc(void) {
char t[] = "/var/tmp/xattrtestXXXXXX";
_cleanup_free_ char *value = NULL;
_cleanup_close_ int fd = -1;
const char *x;
- char v[3];
int r;
- size_t size;
log_info("/* %s */", __func__);
fd = open(t, O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY);
assert_se(fd >= 0);
- assert_se(fgetxattrat_fake(fd, "test", "user.foo", v, 3, 0, &size) >= 0);
- assert_se(size == 3);
- assert_se(memcmp(v, "bar", 3) == 0);
+ assert_se(getxattr_at_malloc(fd, "test", "user.foo", 0, &value) == 3);
+ assert_se(memcmp(value, "bar", 3) == 0);
+ value = mfree(value);
+
+ assert_se(getxattr_at_malloc(AT_FDCWD, x, "user.foo", 0, &value) == 3);
+ assert_se(memcmp(value, "bar", 3) == 0);
+ value = mfree(value);
safe_close(fd);
fd = open("/", O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY);
assert_se(fd >= 0);
- r = fgetxattrat_fake(fd, "usr", "user.idontexist", v, 3, 0, &size);
+ r = getxattr_at_malloc(fd, "usr", "user.idontexist", 0, &value);
assert_se(r == -ENODATA || ERRNO_IS_NOT_SUPPORTED(r));
safe_close(fd);
fd = open(x, O_PATH|O_CLOEXEC);
assert_se(fd >= 0);
- r = fgetxattrat_fake_malloc(fd, NULL, "user.foo", AT_EMPTY_PATH, &value);
- assert_se(r == 3);
+ assert_se(getxattr_at_malloc(fd, NULL, "user.foo", 0, &value) == 3);
assert_se(streq(value, "bar"));
cleanup:
log_info("/* %s */", __func__);
- assert_se(tmp_dir(&vt) >= 0);
+ assert_se(var_tmp_dir(&vt) >= 0);
fd = open_tmpfile_unlinkable(vt, O_RDWR);
assert_se(fd >= 0);
int main(void) {
test_setup_logging(LOG_DEBUG);
- test_fgetxattrat_fake();
+ test_getxattr_at_malloc();
test_getcrtime();
return 0;
projects / thirdparty / systemd.git / commitdiff
