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

4 files changed, 324 insertions, 58 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;
+}
diff --git a/src/shared/copy.h b/src/shared/copy.h
new file mode 100644
index 0000000000..5b569543ee
--- /dev/null
+++ b/src/shared/copy.h
@@ -0,0 +1,25 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#pragma once
+
+/***
+  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/>.
+***/
+
+int copy_file(const char *from, const char *to, int flags, mode_t mode);
+int copy_tree(const char *from, const char *to);
diff --git a/src/shared/util.c b/src/shared/util.c
index 2e832ca384..91cbf20454 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -804,7 +804,7 @@ char *strappend(const char *s, const char *suffix) {
         return strnappend(s, suffix, suffix ? strlen(suffix) : 0);
 }
 
-int readlink_malloc(const char *p, char **ret) {
+int readlinkat_malloc(int fd, const char *p, char **ret) {
         size_t l = 100;
         int r;
 
@@ -819,7 +819,7 @@ int readlink_malloc(const char *p, char **ret) {
                 if (!c)
                         return -ENOMEM;
 
-                n = readlink(p, c, l-1);
+                n = readlinkat(fd, p, c, l-1);
                 if (n < 0) {
                         r = -errno;
                         free(c);
@@ -837,6 +837,10 @@ int readlink_malloc(const char *p, char **ret) {
         }
 }
 
+int readlink_malloc(const char *p, char **ret) {
+        return readlinkat_malloc(AT_FDCWD, p, ret);
+}
+
 int readlink_and_make_absolute(const char *p, char **r) {
         _cleanup_free_ char *target = NULL;
         char *k;
@@ -4128,60 +4132,6 @@ int vt_disallocate(const char *name) {
         return 0;
 }
 
-int copy_file(const char *from, const char *to, int flags) {
-        _cleanup_close_ int fdf = -1;
-        int r, fdt;
-
-        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, 0644);
-        if (fdt < 0)
-                return -errno;
-
-        for (;;) {
-                char buf[PIPE_BUF];
-                ssize_t n, k;
-
-                n = read(fdf, buf, sizeof(buf));
-                if (n < 0) {
-                        r = -errno;
-
-                        close_nointr(fdt);
-                        unlink(to);
-
-                        return r;
-                }
-
-                if (n == 0)
-                        break;
-
-                errno = 0;
-                k = loop_write(fdt, buf, n, false);
-                if (n != k) {
-                        r = k < 0 ? k : (errno ? -errno : -EIO);
-
-                        close_nointr(fdt);
-                        unlink(to);
-
-                        return r;
-                }
-        }
-
-        r = close_nointr(fdt);
-
-        if (r < 0) {
-                unlink(to);
-                return r;
-        }
-
-        return 0;
-}
-
 int symlink_atomic(const char *from, const char *to) {
         char *x;
         _cleanup_free_ char *t;
diff --git a/src/shared/util.h b/src/shared/util.h
index 7618aefad5..0f8c393353 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -252,6 +252,7 @@ char *strnappend(const char *s, const char *suffix, size_t length);
 char *replace_env(const char *format, char **env);
 char **replace_env_argv(char **argv, char **env);
 
+int readlinkat_malloc(int fd, const char *p, char **ret);
 int readlink_malloc(const char *p, char **r);
 int readlink_and_make_absolute(const char *p, char **r);
 int readlink_and_canonicalize(const char *p, char **r);
@@ -521,8 +522,6 @@ int terminal_vhangup(const char *name);
 
 int vt_disallocate(const char *name);
 
-int copy_file(const char *from, const char *to, int flags);
-
 int symlink_atomic(const char *from, const char *to);
 
 int fchmod_umask(int fd, mode_t mode);