From 446aff49ef4a4a415565875a5639cfd24d40632e Mon Sep 17 00:00:00 2001
From: Julien CLEMENT <julien.clement@epita.fr>
Date: Sun, 25 Dec 2022 15:38:45 +0100
Subject: [PATCH] add ISO read

Signed-off-by: Julien CLEMENT <julien.clement@epita.fr>
---
 src/fd/mod.rs         |  2 +-
 src/fs/iso/fd.rs      | 40 ++++++++++++++++++++++++++++++++++------
 src/fs/iso/iso9660.rs |  2 +-
 src/fs/iso/mod.rs     | 19 ++++++++++---------
 src/lib.rs            |  6 +++++-
 5 files changed, 51 insertions(+), 18 deletions(-)

diff --git a/src/fd/mod.rs b/src/fd/mod.rs
index 7aaec5e..c79edca 100644
--- a/src/fd/mod.rs
+++ b/src/fd/mod.rs
@@ -47,5 +47,5 @@ impl FDTable {
 pub trait FileDescriptor {
     fn get_fd(&self) -> FDId;
     async fn write(&mut self, buf: &[u8], count: usize) -> isize;
-    async fn read(&mut self, buf: &[u8], count: usize) -> isize;
+    async fn read(&mut self, buf: &mut [u8], count: usize) -> isize;
 }
diff --git a/src/fs/iso/fd.rs b/src/fs/iso/fd.rs
index 1134950..0b0a2a4 100644
--- a/src/fs/iso/fd.rs
+++ b/src/fs/iso/fd.rs
@@ -1,6 +1,8 @@
+use crate::drivers::atapi::read_block;
 use crate::fd::{FDId, FDt, FileDescriptor};
 use crate::println;
-use crate::utils::mutex::AsyncMutex;
+
+use super::iso9660::{IsoDir, ISO_BLOCK_SIZE};
 
 use alloc::{boxed::Box, sync::Arc};
 use async_trait::async_trait;
@@ -8,11 +10,19 @@ use core::cell::RefCell;
 
 pub struct IsoFD {
     pub fd: FDId,
+    offset: u32,
+    lba: u32,
+    size: u32
 }
 
 impl IsoFD {
-    pub fn new() -> FDt {
-        Arc::new(RefCell::new(IsoFD { fd: FDId::new() }))
+    pub fn new(entry: &IsoDir) -> FDt {
+        Arc::new(RefCell::new(IsoFD {
+            fd: FDId::new(),
+            offset: 0,
+            lba: entry.data_blk.le,
+            size: entry.file_size.le,
+        }))
     }
 }
 
@@ -26,8 +36,26 @@ impl FileDescriptor for IsoFD {
         0
     }
 
-    async fn read(&mut self, buf: &[u8], count: usize) -> isize {
-        println!("Read from fd");
-        0
+    #[allow(unaligned_references)]
+    async fn read(&mut self, buf: &mut [u8], count: usize) -> isize {
+        let mut block_offset = self.offset / ISO_BLOCK_SIZE;
+        let mut content = read_block(self.lba + block_offset).await;
+        let mut read: isize = 0;
+        for _ in 0..count {
+            if self.offset >= self.size {
+                break;
+            }
+
+            buf[read as usize] = content[(self.offset % ISO_BLOCK_SIZE) as usize];
+            read += 1;
+            self.offset += 1;
+
+            if self.offset % ISO_BLOCK_SIZE == 0 {
+                block_offset += 1;
+                content = read_block(self.lba + block_offset).await;
+            }
+        }
+
+        read
     }
 }
diff --git a/src/fs/iso/iso9660.rs b/src/fs/iso/iso9660.rs
index 34afb61..793118d 100644
--- a/src/fs/iso/iso9660.rs
+++ b/src/fs/iso/iso9660.rs
@@ -1,4 +1,4 @@
-pub const ISO_BLOCK_SIZE: usize = 2048;
+pub const ISO_BLOCK_SIZE: u32 = 2048;
 
 // Twin values structs
 
diff --git a/src/fs/iso/mod.rs b/src/fs/iso/mod.rs
index 73e2ae0..ef7b7fe 100644
--- a/src/fs/iso/mod.rs
+++ b/src/fs/iso/mod.rs
@@ -17,6 +17,7 @@ use async_trait::async_trait;
 pub struct IsoFS {}
 
 #[async_trait(?Send)]
+#[allow(unaligned_references)]
 impl FileSystem for IsoFS {
     async fn open(&mut self, path: &str, flags: u32) -> Option<FDt> {
         // ISO is a read only file system
@@ -31,12 +32,13 @@ impl FileSystem for IsoFS {
             return None;
         }
 
-        let root: IsoDir = voldesc.root_dir;
-        let mut curr_entry_block: [u8; iso9660::ISO_BLOCK_SIZE] = read_block(root.data_blk.le).await;
+        let root: &IsoDir = &voldesc.root_dir;
+        let mut curr_entry_block: [u8; iso9660::ISO_BLOCK_SIZE as usize] = read_block(root.data_blk.le).await;
 
         let mut curr_entry: &IsoDir = unserialize(curr_entry_block.as_ptr());
 
         let path_s: String = String::from(path);
+        let path_split: Vec<&str> = path_s.split("/").collect();
         let path_it = path_s
             .split("/")
             .filter(|p| p != &"");
@@ -44,15 +46,14 @@ impl FileSystem for IsoFS {
         for path_component in path_it {
             let mut found = false;
             while curr_entry.idf_len != 0 {
-                serial_println!("{:?}", curr_entry.idf_len);
-                serial_println!("{:?}", alloc::str::from_utf8(curr_entry.get_idf()).unwrap());
 
                 // Found entry
                 if curr_entry.matches(path_component) {
-                    serial_println!("Found {}", path_component);
                     found = true;
-                    curr_entry_block = read_block(curr_entry.data_blk.le).await;
-                    curr_entry = unserialize(curr_entry_block.as_ptr());
+                    if path_component != path_split[path_split.len() - 1] {
+                        curr_entry_block = read_block(curr_entry.data_blk.le).await;
+                        curr_entry = unserialize(curr_entry_block.as_ptr());
+                    }
                     break;
                 }
 
@@ -64,9 +65,9 @@ impl FileSystem for IsoFS {
             }
         }
 
-        let fd = IsoFD::new();
+        let fd = IsoFD::new(curr_entry);
         FD_TABLE.lock().await.register_fd(fd.clone());
-        Some(fd.clone())
+        Some(fd)
     }
 }
 
diff --git a/src/lib.rs b/src/lib.rs
index 32c7641..4aa5b95 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -71,5 +71,9 @@ async fn get_file() {
         .open("///boot/grub//grub.cfg", syscalls::io::O_RDONLY)
         .await
         .unwrap();
-    fd.borrow_mut().read(&[], 0).await;
+    let mut buf: [u8; 100] = [0; 100];
+    let read = fd.borrow_mut().read(&mut buf, 100).await;
+
+    println!("{:?}", read);
+    println!("{:?}", alloc::str::from_utf8(&buf).unwrap());
 }