From 34f1c2ccf76e1e321085d5b8c4b03092f66c7031 Mon Sep 17 00:00:00 2001
From: Mark Poliakov <mark@alnyan.me>
Date: Sat, 22 Jul 2023 00:39:50 +0300
Subject: [PATCH] Support for Read/OpenDirectory

---
 src/io/file.rs | 18 +++++++++++++++++-
 src/io/mod.rs  | 27 ++++++++++++++++++++-------
 src/macros.rs  |  2 +-
 src/syscall.rs |  4 ++++
 4 files changed, 42 insertions(+), 9 deletions(-)

diff --git a/src/io/file.rs b/src/io/file.rs
index 94d40499..f8eba099 100644
--- a/src/io/file.rs
+++ b/src/io/file.rs
@@ -1,4 +1,4 @@
-use crate::bitflags;
+use crate::{bitflags, primitive_enum};
 
 bitflags! {
     #[doc = "Defines the access mode of the file"]
@@ -47,6 +47,22 @@ bitflags! {
     }
 }
 
+primitive_enum!(
+    #[doc = "Defines a type of a file"]
+    pub enum FileType: u32 {
+        #[doc = "Regular file"]
+        File = 0,
+        #[doc = "Directory"]
+        Directory = 1,
+        #[doc = "Not yet implemented"]
+        Symlink = 2,
+        #[doc = "Block device"]
+        Block = 3,
+        #[doc = "Character device (e.g. terminal)"]
+        Char = 4,
+    }
+);
+
 impl FileMode {
     /// File mode with all access bits set
     pub const fn all() -> Self {
diff --git a/src/io/mod.rs b/src/io/mod.rs
index a9d6261e..50080b47 100644
--- a/src/io/mod.rs
+++ b/src/io/mod.rs
@@ -1,17 +1,27 @@
 //! I/O control data structures
 
+mod file;
+mod terminal;
+
+pub use file::{FileMode, FileType, OpenOptions};
+pub use terminal::{
+    TerminalInputOptions, TerminalLineOptions, TerminalOptions, TerminalOutputOptions,
+};
+
 /// Raw file descriptor representation
 #[derive(Clone, Copy, PartialEq, Debug, PartialOrd, Ord, Eq)]
 #[repr(transparent)]
 pub struct RawFd(pub u32);
 
-mod file;
-mod terminal;
-
-pub use file::{FileMode, OpenOptions};
-pub use terminal::{
-    TerminalInputOptions, TerminalLineOptions, TerminalOptions, TerminalOutputOptions,
-};
+/// Raw directory entry representation
+#[derive(Clone, Copy, Debug)]
+#[repr(C)]
+pub struct DirectoryEntry {
+    /// Name of the entry
+    pub name: [u8; 256],
+    /// Type of the entry
+    pub ty: FileType,
+}
 
 /// Describes how a mount operation should be performed
 #[derive(Clone, Debug)]
@@ -40,4 +50,7 @@ impl RawFd {
     pub const STDOUT: Self = Self(1);
     /// Error output descriptor of a process
     pub const STDERR: Self = Self(2);
+
+    /// Temporary hack to represent Option<RawFd>::None
+    pub const NONE: Self = Self(u32::MAX);
 }
diff --git a/src/macros.rs b/src/macros.rs
index 02165bfa..75521902 100644
--- a/src/macros.rs
+++ b/src/macros.rs
@@ -4,7 +4,7 @@ macro_rules! primitive_enum {
     ($(#[doc = $enum_doc:expr])? $vis:vis enum $name:ident: $repr:ty {
         $( $(#[doc = $doc:expr])? $variant:ident = $discriminant:literal, )+
     }) => {
-        #[derive(Clone, Copy, Debug, PartialEq)]
+        #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
         #[repr($repr)]
         $(#[doc = $enum_doc])?
         $vis enum $name {
diff --git a/src/syscall.rs b/src/syscall.rs
index bba7a4ff..c709fbd8 100644
--- a/src/syscall.rs
+++ b/src/syscall.rs
@@ -20,6 +20,10 @@ primitive_enum!(
         Open = 7,
         #[doc = "Close a file descriptor"]
         Close = 8,
+        #[doc = "Open a directory for reading"]
+        OpenDirectory = 9,
+        #[doc = "Read entries from a directory descriptor"]
+        ReadDirectory = 10,
 
         #[doc = "Mount a filesystem"]
         Mount = 101,