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-rw-r--r--src/libbasic/copy.c603
1 files changed, 603 insertions, 0 deletions
diff --git a/src/libbasic/copy.c b/src/libbasic/copy.c
new file mode 100644
index 0000000000..c3586728d0
--- /dev/null
+++ b/src/libbasic/copy.c
@@ -0,0 +1,603 @@
+/***
+ This file is part of systemd.
+
+ Copyright 2014 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 <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/sendfile.h>
+#include <sys/stat.h>
+#include <sys/xattr.h>
+#include <time.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 "fileio.h"
+#include "fs-util.h"
+#include "io-util.h"
+#include "macro.h"
+#include "missing.h"
+#include "string-util.h"
+#include "strv.h"
+#include "time-util.h"
+#include "umask-util.h"
+#include "xattr-util.h"
+
+#define COPY_BUFFER_SIZE (16*1024u)
+
+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 int flags) {
+ static int have = -1;
+ ssize_t r;
+
+ if (have == false)
+ return -ENOSYS;
+
+ r = copy_file_range(fd_in, off_in, fd_out, off_out, len, flags);
+ if (_unlikely_(have < 0))
+ have = r >= 0 || errno != ENOSYS;
+ if (r >= 0)
+ return r;
+ else
+ return -errno;
+}
+
+int copy_bytes(int fdf, int fdt, uint64_t max_bytes, bool try_reflink) {
+ bool try_cfr = true, try_sendfile = true, try_splice = true;
+ int r;
+ size_t m = SSIZE_MAX; /* that is the maximum that sendfile and c_f_r accept */
+
+ assert(fdf >= 0);
+ assert(fdt >= 0);
+
+ /* Try btrfs reflinks first. */
+ if (try_reflink &&
+ max_bytes == (uint64_t) -1 &&
+ lseek(fdf, 0, SEEK_CUR) == 0 &&
+ lseek(fdt, 0, SEEK_CUR) == 0) {
+
+ r = btrfs_reflink(fdf, fdt);
+ if (r >= 0)
+ return 0; /* we copied the whole thing, hence hit EOF, return 0 */
+ }
+
+ for (;;) {
+ ssize_t n;
+
+ if (max_bytes != (uint64_t) -1) {
+ if (max_bytes <= 0)
+ return 1; /* return > 0 if we hit the max_bytes limit */
+
+ if (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) {
+ n = splice(fdf, NULL, fdt, NULL, m, 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)];
+
+ n = read(fdf, buf, sizeof buf);
+ if (n < 0)
+ return -errno;
+ if (n == 0) /* EOF */
+ break;
+
+ r = loop_write(fdt, buf, (size_t) n, false);
+ if (r < 0)
+ return r;
+ }
+
+ next:
+ 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 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) {
+ _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 (symlinkat(target, dt, to) < 0)
+ return -errno;
+
+ if (fchownat(dt, to, st->st_uid, 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) {
+ _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;
+
+ fdt = openat(dt, to, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, st->st_mode & 07777);
+ if (fdt < 0)
+ return -errno;
+
+ r = copy_bytes(fdf, fdt, (uint64_t) -1, true);
+ if (r < 0) {
+ unlinkat(dt, to, 0);
+ return r;
+ }
+
+ if (fchown(fdt, st->st_uid, 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;
+ 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) {
+ int r;
+
+ assert(from);
+ assert(st);
+ assert(to);
+
+ r = mkfifoat(dt, to, st->st_mode & 07777);
+ if (r < 0)
+ return -errno;
+
+ if (fchownat(dt, to, st->st_uid, 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) {
+ int r;
+
+ assert(from);
+ assert(st);
+ assert(to);
+
+ r = mknodat(dt, to, st->st_mode, st->st_rdev);
+ if (r < 0)
+ return -errno;
+
+ if (fchownat(dt, to, st->st_uid, 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,
+ bool merge) {
+
+ _cleanup_close_ int fdf = -1, fdt = -1;
+ _cleanup_closedir_ DIR *d = NULL;
+ struct dirent *de;
+ bool created;
+ int r;
+
+ assert(st);
+ assert(to);
+
+ 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;
+
+ r = mkdirat(dt, to, st->st_mode & 07777);
+ if (r >= 0)
+ created = true;
+ else if (errno == EEXIST && 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) {
+ struct stat buf;
+ int q;
+
+ if (STR_IN_SET(de->d_name, ".", ".."))
+ continue;
+
+ if (fstatat(dirfd(d), de->d_name, &buf, AT_SYMLINK_NOFOLLOW) < 0) {
+ r = -errno;
+ continue;
+ }
+
+ if (buf.st_dev != original_device)
+ continue;
+
+ if (S_ISREG(buf.st_mode))
+ q = fd_copy_regular(dirfd(d), de->d_name, &buf, fdt, de->d_name);
+ else if (S_ISDIR(buf.st_mode))
+ q = fd_copy_directory(dirfd(d), de->d_name, &buf, fdt, de->d_name, original_device, merge);
+ else if (S_ISLNK(buf.st_mode))
+ q = fd_copy_symlink(dirfd(d), de->d_name, &buf, fdt, de->d_name);
+ else if (S_ISFIFO(buf.st_mode))
+ q = fd_copy_fifo(dirfd(d), de->d_name, &buf, fdt, de->d_name);
+ 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);
+ else
+ q = -EOPNOTSUPP;
+
+ if (q == -EEXIST && merge)
+ q = 0;
+
+ if (q < 0)
+ r = q;
+ }
+
+ if (created) {
+ struct timespec ut[2] = {
+ st->st_atim,
+ st->st_mtim
+ };
+
+ if (fchown(fdt, st->st_uid, 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(int fdf, const char *from, int fdt, const char *to, bool merge) {
+ 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);
+ else if (S_ISDIR(st.st_mode))
+ return fd_copy_directory(fdf, from, &st, fdt, to, st.st_dev, merge);
+ else if (S_ISLNK(st.st_mode))
+ return fd_copy_symlink(fdf, from, &st, fdt, to);
+ else if (S_ISFIFO(st.st_mode))
+ return fd_copy_fifo(fdf, from, &st, fdt, to);
+ 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);
+ else
+ return -EOPNOTSUPP;
+}
+
+int copy_tree(const char *from, const char *to, bool merge) {
+ return copy_tree_at(AT_FDCWD, from, AT_FDCWD, to, merge);
+}
+
+int copy_directory_fd(int dirfd, const char *to, bool merge) {
+ 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, merge);
+}
+
+int copy_directory(const char *from, const char *to, bool merge) {
+ 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, merge);
+}
+
+int copy_file_fd(const char *from, int fdt, bool try_reflink) {
+ _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(fdf, fdt, (uint64_t) -1, try_reflink);
+
+ (void) copy_times(fdf, fdt);
+ (void) copy_xattr(fdf, fdt);
+
+ return r;
+}
+
+int copy_file(const char *from, const char *to, int flags, mode_t mode, unsigned chattr_flags) {
+ int fdt = -1, r;
+
+ assert(from);
+ assert(to);
+
+ RUN_WITH_UMASK(0000) {
+ fdt = open(to, flags|O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, mode);
+ if (fdt < 0)
+ return -errno;
+ }
+
+ if (chattr_flags != 0)
+ (void) chattr_fd(fdt, chattr_flags, (unsigned) -1);
+
+ r = copy_file_fd(from, fdt, true);
+ if (r < 0) {
+ close(fdt);
+ unlink(to);
+ return r;
+ }
+
+ if (close(fdt) < 0) {
+ unlink_noerrno(to);
+ return -errno;
+ }
+
+ return 0;
+}
+
+int copy_file_atomic(const char *from, const char *to, mode_t mode, bool replace, unsigned chattr_flags) {
+ _cleanup_free_ char *t = NULL;
+ int r;
+
+ assert(from);
+ assert(to);
+
+ r = tempfn_random(to, NULL, &t);
+ if (r < 0)
+ return r;
+
+ r = copy_file(from, t, O_NOFOLLOW|O_EXCL, mode, chattr_flags);
+ if (r < 0)
+ return r;
+
+ if (replace) {
+ r = renameat(AT_FDCWD, t, AT_FDCWD, to);
+ if (r < 0)
+ r = -errno;
+ } else
+ r = rename_noreplace(AT_FDCWD, t, AT_FDCWD, to);
+ if (r < 0) {
+ (void) unlink_noerrno(t);
+ return r;
+ }
+
+ return 0;
+}
+
+int copy_times(int fdf, int fdt) {
+ struct timespec ut[2];
+ struct stat st;
+ usec_t crtime = 0;
+
+ 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 (fd_getcrtime(fdf, &crtime) >= 0)
+ (void) fd_setcrtime(fdt, crtime);
+
+ return 0;
+}
+
+int copy_xattr(int fdf, int fdt) {
+ _cleanup_free_ char *bufa = NULL, *bufb = NULL;
+ size_t sza = 100, szb = 100;
+ ssize_t n;
+ int ret = 0;
+ const char *p;
+
+ for (;;) {
+ bufa = malloc(sza);
+ if (!bufa)
+ return -ENOMEM;
+
+ n = flistxattr(fdf, bufa, sza);
+ if (n == 0)
+ return 0;
+ if (n > 0)
+ break;
+ if (errno != ERANGE)
+ return -errno;
+
+ sza *= 2;
+
+ bufa = mfree(bufa);
+ }
+
+ p = bufa;
+ while (n > 0) {
+ size_t l;
+
+ l = strlen(p);
+ assert(l < (size_t) n);
+
+ if (startswith(p, "user.")) {
+ ssize_t m;
+
+ if (!bufb) {
+ bufb = malloc(szb);
+ if (!bufb)
+ return -ENOMEM;
+ }
+
+ m = fgetxattr(fdf, p, bufb, szb);
+ if (m < 0) {
+ if (errno == ERANGE) {
+ szb *= 2;
+ bufb = mfree(bufb);
+ continue;
+ }
+
+ return -errno;
+ }
+
+ if (fsetxattr(fdt, p, bufb, m, 0) < 0)
+ ret = -errno;
+ }
+
+ p += l + 1;
+ n -= l + 1;
+ }
+
+ return ret;
+}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-12-26 05:11:13 +0000