tmpfiles: add new "C" line for copying files or directories

1 files changed, 292 insertions, 0 deletions

diff --git a/src/shared/copy.c b/src/shared/copy.c
new file mode 100644
index 0000000000..4dfc2f3fca
--- /dev/null
+++ b/src/shared/copy.c
@@ -0,0 +1,292 @@
+/*-*- 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"
+
+static int stream_bytes(int fdf, int fdt) {
+        assert(fdf >= 0);
+        assert(fdt >= 0);
+
+        for (;;) {
+                char buf[PIPE_BUF];
+                ssize_t n, k;
+
+                n = read(fdf, buf, sizeof(buf));
+                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;
+        }
+
+        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) {
+                if (errno == EEXIST)
+                        return 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) {
+                if (errno == EEXIST)
+                        return 0;
+
+                return -errno;
+        }
+
+        r = stream_bytes(fdf, fdt);
+        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) {
+                if (errno == EEXIST)
+                        return 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) {
+                if (errno == EEXIST)
+                        return 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) {
+        _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)
+                created = false;
+        else
+                return -errno;
+
+        fdt = openat(dt, to, O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
+        if (fdt < 0)
+                return -errno;
+
+        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);
+                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 < 0)
+                        r = q;
+        }
+
+        return r;
+}
+
+int copy_tree(const char *from, const char *to) {
+        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);
+        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 = stream_bytes(fdf, fdt);
+        if (r < 0) {
+                unlink(to);
+                return r;
+        }
+
+        r = close(fdt);
+        fdt = -1;
+
+        if (r < 0) {
+                r = -errno;
+                unlink(to);
+                return r;
+        }
+
+        return 0;
+}