cp: require preserve only certain attributes (#4099)

* cp: require preserve only certain attributes

# Conflicts:
#	src/uu/cp/src/copydir.rs
#	src/uu/cp/src/cp.rs

* tests/cp: preserve all and preserve xattr tests with todos

* tests/cp: rename preserve tests

* tests/cp: add android fail test for preserve=xattr

On Android, this cp with explicit preserve of xattr must fail, because of the limitations of the filesystem setup used on Android.

* cp: verify some metadata in cp preserve tests

# Conflicts:
#	tests/by-util/test_cp.rs

* cp: run test_cp_preserve_all in all OS's but only check metadata on linux

* test/cp: don't expect the mode to change in explicit cp preserve

* cp: attributes struct instead of enum for unified required tracking

* cp: refactor preserver and handle_preserve

# Conflicts:
#	src/uu/cp/src/cp.rs

* cp: update preserve attr to max

* test/cp: fix the preserve xattr test

Access timestamps appear to be modified only in this test. Running the command directly does not alter the access timestamp.

* cp/test: preserve all and context case

* cp: fix preserve args value source

* test/cp: don't check mtime on freebsd

* test/cp: don't check mtime on macos

* test/cp: fix freebsd deps

* test/cp: support freebsd tests

* cp: simplify try_set_from_string

* cp: parse context attr in preserve in any case to show warning later

* cp: print warnings for attribute errors if not required

* cp: show SELinux warning only once

* cp: show SELinux warning without error

* Revert "cp: show SELinux warning without error"

This reverts commit d130cf0d8c8e28ac2c903413992613241decf879.

* cp: add documentation for preserve components

* cp: simplify try_set_from_string

* cp: EN_US "behavior" spelling for cspell

tests/by-util/test_cp.rs

@@ -22,9 +22,7 @@ use filetime::FileTime;
 use rlimit::Resource;
 #[cfg(any(target_os = "linux", target_os = "android"))]
 use std::fs as std_fs;
-#[cfg(not(target_os = "freebsd"))]
 use std::thread::sleep;
-#[cfg(not(target_os = "freebsd"))]
 use std::time::Duration;
 
 static TEST_EXISTING_FILE: &str = "existing_file.txt";
@@ -907,6 +905,91 @@ fn test_cp_preserve_no_args() {
     }
 }
 
+#[test]
+fn test_cp_preserve_all() {
+    let (at, mut ucmd) = at_and_ucmd!();
+    let src_file = "a";
+    let dst_file = "b";
+
+    // Prepare the source file
+    at.touch(src_file);
+    #[cfg(unix)]
+    at.set_mode(src_file, 0o0500);
+
+    // TODO: create a destination that does not allow copying of xattr and context
+    // Copy
+    ucmd.arg(src_file)
+        .arg(dst_file)
+        .arg("--preserve=all")
+        .succeeds();
+
+    #[cfg(all(unix, not(target_os = "freebsd")))]
+    {
+        // Assert that the mode, ownership, and timestamps are preserved
+        // NOTICE: the ownership is not modified on the src file, because that requires root permissions
+        let metadata_src = at.metadata(src_file);
+        let metadata_dst = at.metadata(dst_file);
+        assert_metadata_eq!(metadata_src, metadata_dst);
+    }
+}
+
+#[test]
+#[cfg(all(unix, not(target_os = "android")))]
+fn test_cp_preserve_xattr() {
+    let (at, mut ucmd) = at_and_ucmd!();
+    let src_file = "a";
+    let dst_file = "b";
+
+    // Prepare the source file
+    at.touch(src_file);
+    #[cfg(unix)]
+    at.set_mode(src_file, 0o0500);
+
+    // Sleep so that the time stats are different
+    sleep(Duration::from_secs(1));
+
+    // TODO: create a destination that does not allow copying of xattr and context
+    // Copy
+    ucmd.arg(src_file)
+        .arg(dst_file)
+        .arg("--preserve=xattr")
+        .succeeds();
+
+    // FIXME: macos copy keeps the original mtime
+    #[cfg(not(any(target_os = "freebsd", target_os = "macos")))]
+    {
+        // Assert that the mode, ownership, and timestamps are *NOT* preserved
+        // NOTICE: the ownership is not modified on the src file, because that requires root permissions
+        let metadata_src = at.metadata(src_file);
+        let metadata_dst = at.metadata(dst_file);
+        assert_ne!(metadata_src.mtime(), metadata_dst.mtime());
+        // TODO: verify access time as well. It shouldn't change, however, it does change in this test.
+    }
+}
+
+#[test]
+#[cfg(all(target_os = "linux", not(feature = "feat_selinux")))]
+fn test_cp_preserve_all_context_fails_on_non_selinux() {
+    new_ucmd!()
+        .arg(TEST_COPY_FROM_FOLDER_FILE)
+        .arg(TEST_HELLO_WORLD_DEST)
+        .arg("--preserve=all,context")
+        .fails();
+}
+
+#[test]
+#[cfg(any(target_os = "android"))]
+fn test_cp_preserve_xattr_fails_on_android() {
+    // Because of the SELinux extended attributes used on Android, trying to copy extended
+    // attributes has to fail in this case, since we specify `--preserve=xattr` and this puts it
+    // into the required attributes
+    new_ucmd!()
+        .arg(TEST_COPY_FROM_FOLDER_FILE)
+        .arg(TEST_HELLO_WORLD_DEST)
+        .arg("--preserve=xattr")
+        .fails();
+}
+
 #[test]
 // For now, disable the test on Windows. Symlinks aren't well support on Windows.
 // It works on Unix for now and it works locally when run from a powershell