cp: fix device file creation with -r flag

Fix cp -r to create device files instead of copying content when copying
character and block devices.

Add device detection for character and block devices similar to existing
FIFO handling. Implement make_char_device() and make_block_device()
functions in uucore using mknod syscall to create device files with
correct major/minor numbers.

Update copy logic to create device files when --recursive is used and
--copy-contents is not specified.

Fixes #8679

Author: AnarchistHoneybun

src/uu/cp/locales/en-US.ftl

@@ -86,6 +86,8 @@ cp-error-selinux-set-context = failed to set the security context of { $path }:
 cp-error-selinux-get-context = failed to get security context of { $path }
 cp-error-selinux-error = SELinux error: { $error }
 cp-error-cannot-create-fifo = cannot create fifo { $path }: File exists
+cp-error-cannot-create-char-device = cannot create character device { $path }
+cp-error-cannot-create-block-device = cannot create block device { $path }
 cp-error-invalid-attribute = invalid attribute { $value }
 cp-error-failed-to-create-whole-tree = failed to create whole tree
 cp-error-failed-to-create-directory = Failed to create directory: { $error }

src/uu/cp/locales/fr-FR.ftl

@@ -86,6 +86,8 @@ cp-error-selinux-set-context = échec de la définition du contexte de sécurit
 cp-error-selinux-get-context = échec de l'obtention du contexte de sécurité de { $path }
 cp-error-selinux-error = Erreur SELinux : { $error }
 cp-error-cannot-create-fifo = impossible de créer le fifo { $path } : Le fichier existe
+cp-error-cannot-create-char-device = impossible de créer le périphérique caractère { $path }
+cp-error-cannot-create-block-device = impossible de créer le périphérique bloc { $path }
 cp-error-invalid-attribute = attribut invalide { $value }
 cp-error-failed-to-create-whole-tree = échec de la création de l'arborescence complète
 cp-error-failed-to-create-directory = Échec de la création du répertoire : { $error }

src/uu/cp/src/cp.rs

@@ -10,7 +10,7 @@ use std::ffi::OsString;
 use std::fmt::Display;
 use std::fs::{self, Metadata, OpenOptions, Permissions};
 #[cfg(unix)]
-use std::os::unix::fs::{FileTypeExt, PermissionsExt};
+use std::os::unix::fs::{FileTypeExt, MetadataExt, PermissionsExt};
 #[cfg(unix)]
 use std::os::unix::net::UnixListener;
 use std::path::{Path, PathBuf, StripPrefixError};
@@ -28,7 +28,7 @@ use platform::copy_on_write;
 use uucore::display::Quotable;
 use uucore::error::{UError, UResult, UUsageError, set_exit_code};
 #[cfg(unix)]
-use uucore::fs::make_fifo;
+use uucore::fs::{make_fifo, make_char_device, make_block_device};
 use uucore::fs::{
     FileInformation, MissingHandling, ResolveMode, are_hardlinks_to_same_file, canonicalize,
     get_filename, is_symlink_loop, normalize_path, path_ends_with_terminator,
@@ -2082,6 +2082,8 @@ fn handle_copy_mode(
     source_in_command_line: bool,
     source_is_fifo: bool,
     source_is_socket: bool,
+    source_is_char_device: bool,
+    source_is_block_device: bool,
     #[cfg(unix)] source_is_stream: bool,
 ) -> CopyResult<PerformedAction> {
     let source_is_symlink = source_metadata.is_symlink();
@@ -2122,6 +2124,8 @@ fn handle_copy_mode(
                 source_is_symlink,
                 source_is_fifo,
                 source_is_socket,
+                source_is_char_device,
+                source_is_block_device,
                 symlinked_files,
                 #[cfg(unix)]
                 source_is_stream,
@@ -2145,6 +2149,8 @@ fn handle_copy_mode(
                             source_is_symlink,
                             source_is_fifo,
                             source_is_socket,
+                            source_is_char_device,
+                            source_is_block_device,
                             symlinked_files,
                             #[cfg(unix)]
                             source_is_stream,
@@ -2181,6 +2187,8 @@ fn handle_copy_mode(
                             source_is_symlink,
                             source_is_fifo,
                             source_is_socket,
+                            source_is_char_device,
+                            source_is_block_device,
                             symlinked_files,
                             #[cfg(unix)]
                             source_is_stream,
@@ -2196,6 +2204,8 @@ fn handle_copy_mode(
                     source_is_symlink,
                     source_is_fifo,
                     source_is_socket,
+                    source_is_char_device,
+                    source_is_block_device,
                     symlinked_files,
                     #[cfg(unix)]
                     source_is_stream,
@@ -2424,10 +2434,18 @@ fn copy_file(
     let source_is_fifo = source_metadata.file_type().is_fifo();
     #[cfg(unix)]
     let source_is_socket = source_metadata.file_type().is_socket();
+    #[cfg(unix)]
+    let source_is_char_device = source_metadata.file_type().is_char_device();
+    #[cfg(unix)]
+    let source_is_block_device = source_metadata.file_type().is_block_device();
     #[cfg(not(unix))]
     let source_is_fifo = false;
     #[cfg(not(unix))]
     let source_is_socket = false;
+    #[cfg(not(unix))]
+    let source_is_char_device = false;
+    #[cfg(not(unix))]
+    let source_is_block_device = false;
 
     let source_is_stream = is_stream(&source_metadata);
 
@@ -2441,6 +2459,8 @@ fn copy_file(
         source_in_command_line,
         source_is_fifo,
         source_is_socket,
+        source_is_char_device,
+        source_is_block_device,
         #[cfg(unix)]
         source_is_stream,
     )?;
@@ -2568,6 +2588,8 @@ fn copy_helper(
     source_is_symlink: bool,
     source_is_fifo: bool,
     source_is_socket: bool,
+    source_is_char_device: bool,
+    source_is_block_device: bool,
     symlinked_files: &mut HashSet<FileInformation>,
     #[cfg(unix)] source_is_stream: bool,
 ) -> CopyResult<()> {
@@ -2586,6 +2608,12 @@ fn copy_helper(
     } else if source_is_fifo && options.recursive && !options.copy_contents {
         #[cfg(unix)]
         copy_fifo(dest, options.overwrite, options.debug)?;
+    } else if source_is_char_device && options.recursive && !options.copy_contents {
+        #[cfg(unix)]
+        copy_char_device(source, dest, options.overwrite, options.debug)?;
+    } else if source_is_block_device && options.recursive && !options.copy_contents {
+        #[cfg(unix)]
+        copy_block_device(source, dest, options.overwrite, options.debug)?;
     } else if source_is_symlink {
         copy_link(source, dest, symlinked_files, options)?;
     } else {
@@ -2620,6 +2648,40 @@ fn copy_fifo(dest: &Path, overwrite: OverwriteMode, debug: bool) -> CopyResult<(
         .map_err(|_| translate!("cp-error-cannot-create-fifo", "path" => dest.quote()).into())
 }
 
+// "Copies" a character device by creating a new one with the same major/minor numbers.
+#[cfg(unix)]
+fn copy_char_device(source: &Path, dest: &Path, overwrite: OverwriteMode, debug: bool) -> CopyResult<()> {
+    if dest.exists() {
+        overwrite.verify(dest, debug)?;
+        fs::remove_file(dest)?;
+    }
+
+    let source_metadata = fs::metadata(source)?;
+    let device_id = source_metadata.rdev();
+    let major = ((device_id >> 8) & 0xff) as u32;
+    let minor = (device_id & 0xff) as u32;
+
+    make_char_device(dest, major, minor)
+        .map_err(|_| translate!("cp-error-cannot-create-char-device", "path" => dest.quote()).into())
+}
+
+// "Copies" a block device by creating a new one with the same major/minor numbers.
+#[cfg(unix)]
+fn copy_block_device(source: &Path, dest: &Path, overwrite: OverwriteMode, debug: bool) -> CopyResult<()> {
+    if dest.exists() {
+        overwrite.verify(dest, debug)?;
+        fs::remove_file(dest)?;
+    }
+
+    let source_metadata = fs::metadata(source)?;
+    let device_id = source_metadata.rdev();
+    let major = ((device_id >> 8) & 0xff) as u32;
+    let minor = (device_id & 0xff) as u32;
+
+    make_block_device(dest, major, minor)
+        .map_err(|_| translate!("cp-error-cannot-create-block-device", "path" => dest.quote()).into())
+}
+
 #[cfg(unix)]
 fn copy_socket(dest: &Path, overwrite: OverwriteMode, debug: bool) -> CopyResult<()> {
     if dest.exists() {

src/uucore/src/lib/features/fs.rs

@@ -11,7 +11,7 @@
 use libc::{
     S_IFBLK, S_IFCHR, S_IFDIR, S_IFIFO, S_IFLNK, S_IFMT, S_IFREG, S_IFSOCK, S_IRGRP, S_IROTH,
     S_IRUSR, S_ISGID, S_ISUID, S_ISVTX, S_IWGRP, S_IWOTH, S_IWUSR, S_IXGRP, S_IXOTH, S_IXUSR,
-    mkfifo, mode_t,
+    mkfifo, mknod, makedev, mode_t,
 };
 use std::collections::HashSet;
 use std::collections::VecDeque;
@@ -837,6 +837,42 @@ pub fn make_fifo(path: &Path) -> std::io::Result<()> {
     }
 }
 
+/// Create a character device file.
+///
+/// # Arguments
+/// * `path` - The path where the device file should be created
+/// * `major` - The major device number
+/// * `minor` - The minor device number
+#[cfg(unix)]
+pub fn make_char_device(path: &Path, major: u32, minor: u32) -> std::io::Result<()> {
+    let name = CString::new(path.to_str().unwrap()).unwrap();
+    let dev = makedev(major, minor);
+    let err = unsafe { mknod(name.as_ptr(), S_IFCHR | 0o666, dev) };
+    if err == -1 {
+        Err(std::io::Error::last_os_error())
+    } else {
+        Ok(())
+    }
+}
+
+/// Create a block device file.
+///
+/// # Arguments
+/// * `path` - The path where the device file should be created
+/// * `major` - The major device number
+/// * `minor` - The minor device number
+#[cfg(unix)]
+pub fn make_block_device(path: &Path, major: u32, minor: u32) -> std::io::Result<()> {
+    let name = CString::new(path.to_str().unwrap()).unwrap();
+    let dev = makedev(major, minor);
+    let err = unsafe { mknod(name.as_ptr(), S_IFBLK | 0o666, dev) };
+    if err == -1 {
+        Err(std::io::Error::last_os_error())
+    } else {
+        Ok(())
+    }
+}
+
 #[cfg(test)]
 mod tests {
     // Note this useful idiom: importing names from outer (for mod tests) scope.