/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** 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 "util.h" #include "copy.h" int copy_bytes(int fdf, int fdt, off_t max_bytes) { assert(fdf >= 0); assert(fdt >= 0); for (;;) { char buf[PIPE_BUF]; ssize_t n, k; size_t m = sizeof(buf); if (max_bytes != (off_t) -1) { if (max_bytes <= 0) return -E2BIG; if ((off_t) m > max_bytes) m = (size_t) max_bytes; } n = read(fdf, buf, m); if (n < 0) return -errno; if (n == 0) break; errno = 0; k = loop_write(fdt, buf, n, false); if (k < 0) return k; if (k != n) return errno ? -errno : -EIO; if (max_bytes != (off_t) -1) { assert(max_bytes >= n); max_bytes -= n; } } return 0; } 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; 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, (off_t) -1); 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; 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(from); assert(st); assert(to); fdf = openat(df, from, O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW); 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; if (created) { if (fchown(fdt, st->st_uid, st->st_gid) < 0) r = -errno; if (fchmod(fdt, st->st_mode & 07777) < 0) r = -errno; } FOREACH_DIRENT(de, d, return -errno) { struct stat buf; int q; 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)) q = fd_copy_node(dirfd(d), de->d_name, &buf, fdt, de->d_name); else q = -ENOTSUP; if (q == -EEXIST && merge) q = 0; if (q < 0) r = q; } return r; } int copy_tree(const char *from, const char *to, bool merge) { struct stat st; assert(from); assert(to); if (lstat(from, &st) < 0) return -errno; if (S_ISREG(st.st_mode)) return fd_copy_regular(AT_FDCWD, from, &st, AT_FDCWD, to); else if (S_ISDIR(st.st_mode)) return fd_copy_directory(AT_FDCWD, from, &st, AT_FDCWD, to, st.st_dev, merge); else if (S_ISLNK(st.st_mode)) return fd_copy_symlink(AT_FDCWD, from, &st, AT_FDCWD, to); else if (S_ISFIFO(st.st_mode)) return fd_copy_fifo(AT_FDCWD, from, &st, AT_FDCWD, to); else if (S_ISBLK(st.st_mode) || S_ISCHR(st.st_mode)) return fd_copy_node(AT_FDCWD, from, &st, AT_FDCWD, to); else return -ENOTSUP; } int copy_file(const char *from, const char *to, int flags, mode_t mode) { _cleanup_close_ int fdf = -1, fdt = -1; int r; assert(from); assert(to); fdf = open(from, O_RDONLY|O_CLOEXEC|O_NOCTTY); if (fdf < 0) return -errno; fdt = open(to, flags|O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, mode); if (fdt < 0) return -errno; r = copy_bytes(fdf, fdt, (off_t) -1); if (r < 0) { unlink(to); return r; } r = close(fdt); fdt = -1; if (r < 0) { r = -errno; unlink(to); return r; } return 0; }