blob: 97d566c5b936b250c0bc7693f58d567de982c95d [file] [log] [blame] [raw]
/* SPDX-License-Identifier: LGPL-2.1+ */
#include <errno.h>
#include <fcntl.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/sendfile.h>
#include <sys/xattr.h>
#include <unistd.h>
#include "alloc-util.h"
#include "btrfs-util.h"
#include "chattr-util.h"
#include "copy.h"
#include "dirent-util.h"
#include "fd-util.h"
#include "fs-util.h"
#include "io-util.h"
#include "macro.h"
#include "missing_syscall.h"
#include "mountpoint-util.h"
#include "nulstr-util.h"
#include "selinux-util.h"
#include "stat-util.h"
#include "string-util.h"
#include "strv.h"
#include "time-util.h"
#include "tmpfile-util.h"
#include "umask-util.h"
#include "user-util.h"
#include "xattr-util.h"
#define COPY_BUFFER_SIZE (16U*1024U)
/* A safety net for descending recursively into file system trees to copy. On Linux PATH_MAX is 4096, which means the
* deepest valid path one can build is around 2048, which we hence use as a safety net here, to not spin endlessly in
* case of bind mount cycles and suchlike. */
#define COPY_DEPTH_MAX 2048U
static ssize_t try_copy_file_range(
int fd_in, loff_t *off_in,
int fd_out, loff_t *off_out,
size_t len,
unsigned flags) {
static int have = -1;
ssize_t r;
if (have == 0)
return -ENOSYS;
r = copy_file_range(fd_in, off_in, fd_out, off_out, len, flags);
if (have < 0)
have = r >= 0 || errno != ENOSYS;
if (r < 0)
return -errno;
return r;
}
enum {
FD_IS_NO_PIPE,
FD_IS_BLOCKING_PIPE,
FD_IS_NONBLOCKING_PIPE,
};
static int fd_is_nonblock_pipe(int fd) {
struct stat st;
int flags;
/* Checks whether the specified file descriptor refers to a pipe, and if so if O_NONBLOCK is set. */
if (fstat(fd, &st) < 0)
return -errno;
if (!S_ISFIFO(st.st_mode))
return FD_IS_NO_PIPE;
flags = fcntl(fd, F_GETFL);
if (flags < 0)
return -errno;
return FLAGS_SET(flags, O_NONBLOCK) ? FD_IS_NONBLOCKING_PIPE : FD_IS_BLOCKING_PIPE;
}
static int sigint_pending(void) {
sigset_t ss;
assert_se(sigemptyset(&ss) >= 0);
assert_se(sigaddset(&ss, SIGINT) >= 0);
if (sigtimedwait(&ss, NULL, &(struct timespec) { 0, 0 }) < 0) {
if (errno == EAGAIN)
return false;
return -errno;
}
return true;
}
int copy_bytes_full(
int fdf, int fdt,
uint64_t max_bytes,
CopyFlags copy_flags,
void **ret_remains,
size_t *ret_remains_size,
copy_progress_bytes_t progress,
void *userdata) {
bool try_cfr = true, try_sendfile = true, try_splice = true;
int r, nonblock_pipe = -1;
size_t m = SSIZE_MAX; /* that is the maximum that sendfile and c_f_r accept */
assert(fdf >= 0);
assert(fdt >= 0);
/* Tries to copy bytes from the file descriptor 'fdf' to 'fdt' in the smartest possible way. Copies a maximum
* of 'max_bytes', which may be specified as UINT64_MAX, in which no maximum is applied. Returns negative on
* error, zero if EOF is hit before the bytes limit is hit and positive otherwise. If the copy fails for some
* reason but we read but didn't yet write some data an ret_remains/ret_remains_size is not NULL, then it will
* be initialized with an allocated buffer containing this "remaining" data. Note that these two parameters are
* initialized with a valid buffer only on failure and only if there's actually data already read. Otherwise
* these parameters if non-NULL are set to NULL. */
if (ret_remains)
*ret_remains = NULL;
if (ret_remains_size)
*ret_remains_size = 0;
/* Try btrfs reflinks first. This only works on regular, seekable files, hence let's check the file offsets of
* source and destination first. */
if ((copy_flags & COPY_REFLINK)) {
off_t foffset;
foffset = lseek(fdf, 0, SEEK_CUR);
if (foffset >= 0) {
off_t toffset;
toffset = lseek(fdt, 0, SEEK_CUR);
if (toffset >= 0) {
if (foffset == 0 && toffset == 0 && max_bytes == UINT64_MAX)
r = btrfs_reflink(fdf, fdt); /* full file reflink */
else
r = btrfs_clone_range(fdf, foffset, fdt, toffset, max_bytes == UINT64_MAX ? 0 : max_bytes); /* partial reflink */
if (r >= 0) {
off_t t;
/* This worked, yay! Now — to be fully correct — let's adjust the file pointers */
if (max_bytes == UINT64_MAX) {
/* We cloned to the end of the source file, let's position the read
* pointer there, and query it at the same time. */
t = lseek(fdf, 0, SEEK_END);
if (t < 0)
return -errno;
if (t < foffset)
return -ESPIPE;
/* Let's adjust the destination file write pointer by the same number
* of bytes. */
t = lseek(fdt, toffset + (t - foffset), SEEK_SET);
if (t < 0)
return -errno;
return 0; /* we copied the whole thing, hence hit EOF, return 0 */
} else {
t = lseek(fdf, foffset + max_bytes, SEEK_SET);
if (t < 0)
return -errno;
t = lseek(fdt, toffset + max_bytes, SEEK_SET);
if (t < 0)
return -errno;
return 1; /* we copied only some number of bytes, which worked, but this means we didn't hit EOF, return 1 */
}
}
}
}
}
for (;;) {
ssize_t n;
if (max_bytes <= 0)
return 1; /* return > 0 if we hit the max_bytes limit */
if (FLAGS_SET(copy_flags, COPY_SIGINT)) {
r = sigint_pending();
if (r < 0)
return r;
if (r > 0)
return -EINTR;
}
if (max_bytes != UINT64_MAX && m > max_bytes)
m = max_bytes;
/* First try copy_file_range(), unless we already tried */
if (try_cfr) {
n = try_copy_file_range(fdf, NULL, fdt, NULL, m, 0u);
if (n < 0) {
if (!IN_SET(n, -EINVAL, -ENOSYS, -EXDEV, -EBADF))
return n;
try_cfr = false;
/* use fallback below */
} else if (n == 0) /* EOF */
break;
else
/* Success! */
goto next;
}
/* First try sendfile(), unless we already tried */
if (try_sendfile) {
n = sendfile(fdt, fdf, NULL, m);
if (n < 0) {
if (!IN_SET(errno, EINVAL, ENOSYS))
return -errno;
try_sendfile = false;
/* use fallback below */
} else if (n == 0) /* EOF */
break;
else
/* Success! */
goto next;
}
/* Then try splice, unless we already tried. */
if (try_splice) {
/* splice()'s asynchronous I/O support is a bit weird. When it encounters a pipe file
* descriptor, then it will ignore its O_NONBLOCK flag and instead only honour the
* SPLICE_F_NONBLOCK flag specified in its flag parameter. Let's hide this behaviour here, and
* check if either of the specified fds are a pipe, and if so, let's pass the flag
* automatically, depending on O_NONBLOCK being set.
*
* Here's a twist though: when we use it to move data between two pipes of which one has
* O_NONBLOCK set and the other has not, then we have no individual control over O_NONBLOCK
* behaviour. Hence in that case we can't use splice() and still guarantee systematic
* O_NONBLOCK behaviour, hence don't. */
if (nonblock_pipe < 0) {
int a, b;
/* Check if either of these fds is a pipe, and if so non-blocking or not */
a = fd_is_nonblock_pipe(fdf);
if (a < 0)
return a;
b = fd_is_nonblock_pipe(fdt);
if (b < 0)
return b;
if ((a == FD_IS_NO_PIPE && b == FD_IS_NO_PIPE) ||
(a == FD_IS_BLOCKING_PIPE && b == FD_IS_NONBLOCKING_PIPE) ||
(a == FD_IS_NONBLOCKING_PIPE && b == FD_IS_BLOCKING_PIPE))
/* splice() only works if one of the fds is a pipe. If neither is, let's skip
* this step right-away. As mentioned above, if one of the two fds refers to a
* blocking pipe and the other to a non-blocking pipe, we can't use splice()
* either, hence don't try either. This hence means we can only use splice() if
* either only one of the two fds is a pipe, or if both are pipes with the same
* nonblocking flag setting. */
try_splice = false;
else
nonblock_pipe = a == FD_IS_NONBLOCKING_PIPE || b == FD_IS_NONBLOCKING_PIPE;
}
}
if (try_splice) {
n = splice(fdf, NULL, fdt, NULL, m, nonblock_pipe ? SPLICE_F_NONBLOCK : 0);
if (n < 0) {
if (!IN_SET(errno, EINVAL, ENOSYS))
return -errno;
try_splice = false;
/* use fallback below */
} else if (n == 0) /* EOF */
break;
else
/* Success! */
goto next;
}
/* As a fallback just copy bits by hand */
{
uint8_t buf[MIN(m, COPY_BUFFER_SIZE)], *p = buf;
ssize_t z;
n = read(fdf, buf, sizeof buf);
if (n < 0)
return -errno;
if (n == 0) /* EOF */
break;
z = (size_t) n;
do {
ssize_t k;
k = write(fdt, p, z);
if (k < 0) {
r = -errno;
if (ret_remains) {
void *copy;
copy = memdup(p, z);
if (!copy)
return -ENOMEM;
*ret_remains = copy;
}
if (ret_remains_size)
*ret_remains_size = z;
return r;
}
assert(k <= z);
z -= k;
p += k;
} while (z > 0);
}
next:
if (progress) {
r = progress(n, userdata);
if (r < 0)
return r;
}
if (max_bytes != (uint64_t) -1) {
assert(max_bytes >= (uint64_t) n);
max_bytes -= n;
}
/* sendfile accepts at most SSIZE_MAX-offset bytes to copy,
* so reduce our maximum by the amount we already copied,
* but don't go below our copy buffer size, unless we are
* close the limit of bytes we are allowed to copy. */
m = MAX(MIN(COPY_BUFFER_SIZE, max_bytes), m - n);
}
return 0; /* return 0 if we hit EOF earlier than the size limit */
}
static int fd_copy_symlink(
int df,
const char *from,
const struct stat *st,
int dt,
const char *to,
uid_t override_uid,
gid_t override_gid,
CopyFlags copy_flags) {
_cleanup_free_ char *target = NULL;
int r;
assert(from);
assert(st);
assert(to);
r = readlinkat_malloc(df, from, &target);
if (r < 0)
return r;
if (copy_flags & COPY_MAC_CREATE) {
r = mac_selinux_create_file_prepare_at(dt, to, S_IFLNK);
if (r < 0)
return r;
}
r = symlinkat(target, dt, to);
if (copy_flags & COPY_MAC_CREATE)
mac_selinux_create_file_clear();
if (r < 0)
return -errno;
if (fchownat(dt, to,
uid_is_valid(override_uid) ? override_uid : st->st_uid,
gid_is_valid(override_gid) ? override_gid : st->st_gid,
AT_SYMLINK_NOFOLLOW) < 0)
return -errno;
return 0;
}
static int fd_copy_regular(
int df,
const char *from,
const struct stat *st,
int dt,
const char *to,
uid_t override_uid,
gid_t override_gid,
CopyFlags copy_flags,
copy_progress_bytes_t progress,
void *userdata) {
_cleanup_close_ int fdf = -1, fdt = -1;
struct timespec ts[2];
int r, q;
assert(from);
assert(st);
assert(to);
fdf = openat(df, from, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
if (fdf < 0)
return -errno;
if (copy_flags & COPY_MAC_CREATE) {
r = mac_selinux_create_file_prepare_at(dt, to, S_IFREG);
if (r < 0)
return r;
}
fdt = openat(dt, to, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, st->st_mode & 07777);
if (copy_flags & COPY_MAC_CREATE)
mac_selinux_create_file_clear();
if (fdt < 0)
return -errno;
r = copy_bytes_full(fdf, fdt, (uint64_t) -1, copy_flags, NULL, NULL, progress, userdata);
if (r < 0) {
(void) unlinkat(dt, to, 0);
return r;
}
if (fchown(fdt,
uid_is_valid(override_uid) ? override_uid : st->st_uid,
gid_is_valid(override_gid) ? override_gid : st->st_gid) < 0)
r = -errno;
if (fchmod(fdt, st->st_mode & 07777) < 0)
r = -errno;
ts[0] = st->st_atim;
ts[1] = st->st_mtim;
(void) futimens(fdt, ts);
(void) copy_xattr(fdf, fdt);
q = close(fdt);
fdt = -1;
if (q < 0) {
r = -errno;
(void) unlinkat(dt, to, 0);
}
return r;
}
static int fd_copy_fifo(
int df,
const char *from,
const struct stat *st,
int dt,
const char *to,
uid_t override_uid,
gid_t override_gid,
CopyFlags copy_flags) {
int r;
assert(from);
assert(st);
assert(to);
if (copy_flags & COPY_MAC_CREATE) {
r = mac_selinux_create_file_prepare_at(dt, to, S_IFIFO);
if (r < 0)
return r;
}
r = mkfifoat(dt, to, st->st_mode & 07777);
if (copy_flags & COPY_MAC_CREATE)
mac_selinux_create_file_clear();
if (r < 0)
return -errno;
if (fchownat(dt, to,
uid_is_valid(override_uid) ? override_uid : st->st_uid,
gid_is_valid(override_gid) ? override_gid : st->st_gid,
AT_SYMLINK_NOFOLLOW) < 0)
r = -errno;
if (fchmodat(dt, to, st->st_mode & 07777, 0) < 0)
r = -errno;
return r;
}
static int fd_copy_node(
int df,
const char *from,
const struct stat *st,
int dt,
const char *to,
uid_t override_uid,
gid_t override_gid,
CopyFlags copy_flags) {
int r;
assert(from);
assert(st);
assert(to);
if (copy_flags & COPY_MAC_CREATE) {
r = mac_selinux_create_file_prepare_at(dt, to, st->st_mode & S_IFMT);
if (r < 0)
return r;
}
r = mknodat(dt, to, st->st_mode, st->st_rdev);
if (copy_flags & COPY_MAC_CREATE)
mac_selinux_create_file_clear();
if (r < 0)
return -errno;
if (fchownat(dt, to,
uid_is_valid(override_uid) ? override_uid : st->st_uid,
gid_is_valid(override_gid) ? override_gid : st->st_gid,
AT_SYMLINK_NOFOLLOW) < 0)
r = -errno;
if (fchmodat(dt, to, st->st_mode & 07777, 0) < 0)
r = -errno;
return r;
}
static int fd_copy_directory(
int df,
const char *from,
const struct stat *st,
int dt,
const char *to,
dev_t original_device,
unsigned depth_left,
uid_t override_uid,
gid_t override_gid,
CopyFlags copy_flags,
const char *display_path,
copy_progress_path_t progress_path,
copy_progress_bytes_t progress_bytes,
void *userdata) {
_cleanup_close_ int fdf = -1, fdt = -1;
_cleanup_closedir_ DIR *d = NULL;
struct dirent *de;
bool exists, created;
int r;
assert(st);
assert(to);
if (depth_left == 0)
return -ENAMETOOLONG;
if (from)
fdf = openat(df, from, O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
else
fdf = fcntl(df, F_DUPFD_CLOEXEC, 3);
if (fdf < 0)
return -errno;
d = fdopendir(fdf);
if (!d)
return -errno;
fdf = -1;
exists = false;
if (copy_flags & COPY_MERGE_EMPTY) {
r = dir_is_empty_at(dt, to);
if (r < 0 && r != -ENOENT)
return r;
else if (r == 1)
exists = true;
}
if (exists)
created = false;
else {
if (copy_flags & COPY_MAC_CREATE)
r = mkdirat_label(dt, to, st->st_mode & 07777);
else
r = mkdirat(dt, to, st->st_mode & 07777);
if (r >= 0)
created = true;
else if (errno == EEXIST && (copy_flags & COPY_MERGE))
created = false;
else
return -errno;
}
fdt = openat(dt, to, O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
if (fdt < 0)
return -errno;
r = 0;
FOREACH_DIRENT_ALL(de, d, return -errno) {
const char *child_display_path = NULL;
_cleanup_free_ char *dp = NULL;
struct stat buf;
int q;
if (dot_or_dot_dot(de->d_name))
continue;
if (FLAGS_SET(copy_flags, COPY_SIGINT)) {
r = sigint_pending();
if (r < 0)
return r;
if (r > 0)
return -EINTR;
}
if (fstatat(dirfd(d), de->d_name, &buf, AT_SYMLINK_NOFOLLOW) < 0) {
r = -errno;
continue;
}
if (progress_path) {
if (display_path)
child_display_path = dp = path_join(display_path, de->d_name);
else
child_display_path = de->d_name;
r = progress_path(child_display_path, &buf, userdata);
if (r < 0)
return r;
}
if (S_ISDIR(buf.st_mode)) {
/*
* Don't descend into directories on other file systems, if this is requested. We do a simple
* .st_dev check here, which basically comes for free. Note that we do this check only on
* directories, not other kind of file system objects, for two reason:
*
* • The kernel's overlayfs pseudo file system that overlays multiple real file systems
* propagates the .st_dev field of the file system a file originates from all the way up
* through the stack to stat(). It doesn't do that for directories however. This means that
* comparing .st_dev on non-directories suggests that they all are mount points. To avoid
* confusion we hence avoid relying on this check for regular files.
*
* • The main reason we do this check at all is to protect ourselves from bind mount cycles,
* where we really want to avoid descending down in all eternity. However the .st_dev check
* is usually not sufficient for this protection anyway, as bind mount cycles from the same
* file system onto itself can't be detected that way. (Note we also do a recursion depth
* check, which is probably the better protection in this regard, which is why
* COPY_SAME_MOUNT is optional).
*/
if (FLAGS_SET(copy_flags, COPY_SAME_MOUNT)) {
if (buf.st_dev != original_device)
continue;
r = fd_is_mount_point(dirfd(d), de->d_name, 0);
if (r < 0)
return r;
if (r > 0)
continue;
}
q = fd_copy_directory(dirfd(d), de->d_name, &buf, fdt, de->d_name, original_device, depth_left-1, override_uid, override_gid, copy_flags, child_display_path, progress_path, progress_bytes, userdata);
} else if (S_ISREG(buf.st_mode))
q = fd_copy_regular(dirfd(d), de->d_name, &buf, fdt, de->d_name, override_uid, override_gid, copy_flags, progress_bytes, userdata);
else if (S_ISLNK(buf.st_mode))
q = fd_copy_symlink(dirfd(d), de->d_name, &buf, fdt, de->d_name, override_uid, override_gid, copy_flags);
else if (S_ISFIFO(buf.st_mode))
q = fd_copy_fifo(dirfd(d), de->d_name, &buf, fdt, de->d_name, override_uid, override_gid, copy_flags);
else if (S_ISBLK(buf.st_mode) || S_ISCHR(buf.st_mode) || S_ISSOCK(buf.st_mode))
q = fd_copy_node(dirfd(d), de->d_name, &buf, fdt, de->d_name, override_uid, override_gid, copy_flags);
else
q = -EOPNOTSUPP;
if (q == -EINTR) /* Propagate SIGINT up instantly */
return q;
if (q == -EEXIST && (copy_flags & COPY_MERGE))
q = 0;
if (q < 0)
r = q;
}
if (created) {
struct timespec ut[2] = {
st->st_atim,
st->st_mtim
};
if (fchown(fdt,
uid_is_valid(override_uid) ? override_uid : st->st_uid,
gid_is_valid(override_gid) ? override_gid : st->st_gid) < 0)
r = -errno;
if (fchmod(fdt, st->st_mode & 07777) < 0)
r = -errno;
(void) copy_xattr(dirfd(d), fdt);
(void) futimens(fdt, ut);
}
return r;
}
int copy_tree_at_full(
int fdf,
const char *from,
int fdt,
const char *to,
uid_t override_uid,
gid_t override_gid,
CopyFlags copy_flags,
copy_progress_path_t progress_path,
copy_progress_bytes_t progress_bytes,
void *userdata) {
struct stat st;
assert(from);
assert(to);
if (fstatat(fdf, from, &st, AT_SYMLINK_NOFOLLOW) < 0)
return -errno;
if (S_ISREG(st.st_mode))
return fd_copy_regular(fdf, from, &st, fdt, to, override_uid, override_gid, copy_flags, progress_bytes, userdata);
else if (S_ISDIR(st.st_mode))
return fd_copy_directory(fdf, from, &st, fdt, to, st.st_dev, COPY_DEPTH_MAX, override_uid, override_gid, copy_flags, NULL, progress_path, progress_bytes, userdata);
else if (S_ISLNK(st.st_mode))
return fd_copy_symlink(fdf, from, &st, fdt, to, override_uid, override_gid, copy_flags);
else if (S_ISFIFO(st.st_mode))
return fd_copy_fifo(fdf, from, &st, fdt, to, override_uid, override_gid, copy_flags);
else if (S_ISBLK(st.st_mode) || S_ISCHR(st.st_mode) || S_ISSOCK(st.st_mode))
return fd_copy_node(fdf, from, &st, fdt, to, override_uid, override_gid, copy_flags);
else
return -EOPNOTSUPP;
}
int copy_directory_fd_full(
int dirfd,
const char *to,
CopyFlags copy_flags,
copy_progress_path_t progress_path,
copy_progress_bytes_t progress_bytes,
void *userdata) {
struct stat st;
assert(dirfd >= 0);
assert(to);
if (fstat(dirfd, &st) < 0)
return -errno;
if (!S_ISDIR(st.st_mode))
return -ENOTDIR;
return fd_copy_directory(dirfd, NULL, &st, AT_FDCWD, to, st.st_dev, COPY_DEPTH_MAX, UID_INVALID, GID_INVALID, copy_flags, NULL, progress_path, progress_bytes, userdata);
}
int copy_directory_full(
const char *from,
const char *to,
CopyFlags copy_flags,
copy_progress_path_t progress_path,
copy_progress_bytes_t progress_bytes,
void *userdata) {
struct stat st;
assert(from);
assert(to);
if (lstat(from, &st) < 0)
return -errno;
if (!S_ISDIR(st.st_mode))
return -ENOTDIR;
return fd_copy_directory(AT_FDCWD, from, &st, AT_FDCWD, to, st.st_dev, COPY_DEPTH_MAX, UID_INVALID, GID_INVALID, copy_flags, NULL, progress_path, progress_bytes, userdata);
}
int copy_file_fd_full(
const char *from,
int fdt,
CopyFlags copy_flags,
copy_progress_bytes_t progress_bytes,
void *userdata) {
_cleanup_close_ int fdf = -1;
int r;
assert(from);
assert(fdt >= 0);
fdf = open(from, O_RDONLY|O_CLOEXEC|O_NOCTTY);
if (fdf < 0)
return -errno;
r = copy_bytes_full(fdf, fdt, (uint64_t) -1, copy_flags, NULL, NULL, progress_bytes, userdata);
(void) copy_times(fdf, fdt, copy_flags);
(void) copy_xattr(fdf, fdt);
return r;
}
int copy_file_full(
const char *from,
const char *to,
int flags,
mode_t mode,
unsigned chattr_flags,
unsigned chattr_mask,
CopyFlags copy_flags,
copy_progress_bytes_t progress_bytes,
void *userdata) {
int fdt = -1, r;
assert(from);
assert(to);
RUN_WITH_UMASK(0000) {
if (copy_flags & COPY_MAC_CREATE) {
r = mac_selinux_create_file_prepare(to, S_IFREG);
if (r < 0)
return r;
}
fdt = open(to, flags|O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, mode);
if (copy_flags & COPY_MAC_CREATE)
mac_selinux_create_file_clear();
if (fdt < 0)
return -errno;
}
if (chattr_mask != 0)
(void) chattr_fd(fdt, chattr_flags, chattr_mask & CHATTR_EARLY_FL, NULL);
r = copy_file_fd_full(from, fdt, copy_flags, progress_bytes, userdata);
if (r < 0) {
close(fdt);
(void) unlink(to);
return r;
}
if (chattr_mask != 0)
(void) chattr_fd(fdt, chattr_flags, chattr_mask & ~CHATTR_EARLY_FL, NULL);
if (close(fdt) < 0) {
unlink_noerrno(to);
return -errno;
}
return 0;
}
int copy_file_atomic_full(
const char *from,
const char *to,
mode_t mode,
unsigned chattr_flags,
unsigned chattr_mask,
CopyFlags copy_flags,
copy_progress_bytes_t progress_bytes,
void *userdata) {
_cleanup_(unlink_and_freep) char *t = NULL;
_cleanup_close_ int fdt = -1;
int r;
assert(from);
assert(to);
/* We try to use O_TMPFILE here to create the file if we can. Note that that only works if COPY_REPLACE is not
* set though as we need to use linkat() for linking the O_TMPFILE file into the file system but that system
* call can't replace existing files. Hence, if COPY_REPLACE is set we create a temporary name in the file
* system right-away and unconditionally which we then can renameat() to the right name after we completed
* writing it. */
if (copy_flags & COPY_REPLACE) {
r = tempfn_random(to, NULL, &t);
if (r < 0)
return r;
if (copy_flags & COPY_MAC_CREATE) {
r = mac_selinux_create_file_prepare(to, S_IFREG);
if (r < 0) {
t = mfree(t);
return r;
}
}
fdt = open(t, O_CREAT|O_EXCL|O_NOFOLLOW|O_NOCTTY|O_WRONLY|O_CLOEXEC, 0600);
if (copy_flags & COPY_MAC_CREATE)
mac_selinux_create_file_clear();
if (fdt < 0) {
t = mfree(t);
return -errno;
}
} else {
if (copy_flags & COPY_MAC_CREATE) {
r = mac_selinux_create_file_prepare(to, S_IFREG);
if (r < 0)
return r;
}
fdt = open_tmpfile_linkable(to, O_WRONLY|O_CLOEXEC, &t);
if (copy_flags & COPY_MAC_CREATE)
mac_selinux_create_file_clear();
if (fdt < 0)
return fdt;
}
if (chattr_mask != 0)
(void) chattr_fd(fdt, chattr_flags, chattr_mask & CHATTR_EARLY_FL, NULL);
r = copy_file_fd_full(from, fdt, copy_flags, progress_bytes, userdata);
if (r < 0)
return r;
if (fchmod(fdt, mode) < 0)
return -errno;
if (copy_flags & COPY_REPLACE) {
if (renameat(AT_FDCWD, t, AT_FDCWD, to) < 0)
return -errno;
} else {
r = link_tmpfile(fdt, t, to);
if (r < 0)
return r;
}
if (chattr_mask != 0)
(void) chattr_fd(fdt, chattr_flags, chattr_mask & ~CHATTR_EARLY_FL, NULL);
t = mfree(t);
return 0;
}
int copy_times(int fdf, int fdt, CopyFlags flags) {
struct timespec ut[2];
struct stat st;
assert(fdf >= 0);
assert(fdt >= 0);
if (fstat(fdf, &st) < 0)
return -errno;
ut[0] = st.st_atim;
ut[1] = st.st_mtim;
if (futimens(fdt, ut) < 0)
return -errno;
if (FLAGS_SET(flags, COPY_CRTIME)) {
usec_t crtime;
if (fd_getcrtime(fdf, &crtime) >= 0)
(void) fd_setcrtime(fdt, crtime);
}
return 0;
}
int copy_xattr(int fdf, int fdt) {
_cleanup_free_ char *names = NULL;
int ret = 0, r;
const char *p;
r = flistxattr_malloc(fdf, &names);
if (r < 0)
return r;
NULSTR_FOREACH(p, names) {
_cleanup_free_ char *value = NULL;
if (!startswith(p, "user."))
continue;
r = fgetxattr_malloc(fdf, p, &value);
if (r == -ENODATA)
continue; /* gone by now */
if (r < 0)
return r;
if (fsetxattr(fdt, p, value, r, 0) < 0)
ret = -errno;
}
return ret;
}