From beb653305967b62210eb3fbf635587445b2fbc6f Mon Sep 17 00:00:00 2001
From: WangRunji <wangrunji0408@163.com>
Date: Thu, 8 Nov 2018 16:56:01 +0800
Subject: [PATCH] impl sys_getdirentry. 'ls' ok.

---
 kernel/Cargo.lock     |  2 +-
 kernel/src/syscall.rs | 44 ++++++++++++++++++++++++++++++++++++++++---
 2 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/kernel/Cargo.lock b/kernel/Cargo.lock
index d715539..0e42a9c 100644
--- a/kernel/Cargo.lock
+++ b/kernel/Cargo.lock
@@ -209,7 +209,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "simple-filesystem"
 version = "0.0.1"
-source = "git+https://github.com/wangrunji0408/SimpleFileSystem-Rust?branch=multi-thread#fe473bc987a9a5dfd7ffe91883f8781b910ed45e"
+source = "git+https://github.com/wangrunji0408/SimpleFileSystem-Rust?branch=multi-thread#978c3a70ca7bd3fdd536cc91b8d2f2f3b2dcb29b"
 dependencies = [
  "bit-vec 0.5.0 (git+https://github.com/AltSysrq/bit-vec.git)",
  "spin 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/kernel/src/syscall.rs b/kernel/src/syscall.rs
index d9f916c..1d79e66 100644
--- a/kernel/src/syscall.rs
+++ b/kernel/src/syscall.rs
@@ -1,7 +1,5 @@
 //! System call
 
-#![allow(unused)]
-
 use arch::interrupt::TrapFrame;
 use process::*;
 use thread;
@@ -24,7 +22,7 @@ pub fn syscall(id: usize, args: [usize; 6], tf: &TrapFrame) -> i32 {
         110 => sys_fstat(args[0], args[1] as *mut Stat),
 //        111 => sys_fsync(),
 //        121 => sys_getcwd(),
-//        128 => sys_getdirentry(args[0], args[1]),
+        128 => sys_getdirentry(args[0], args[1] as *mut DirEntry),
         130 => sys_dup(args[0], args[1]),
 
         // process
@@ -138,6 +136,26 @@ fn sys_fstat(fd: usize, stat_ptr: *mut Stat) -> i32 {
     0
 }
 
+/// entry_id = dentry.offset / 256
+/// dentry.name = entry_name
+/// dentry.offset += 256
+fn sys_getdirentry(fd: usize, dentry_ptr: *mut DirEntry) -> i32 {
+    // TODO: check ptr
+    info!("getdirentry: {}", fd);
+    let file = process().files.get(&fd);
+    if file.is_none() { return -1; }
+    let file = file.unwrap();
+    let dentry = unsafe { &mut *dentry_ptr };
+    if !dentry.check() { return -1; }
+    let info = file.lock().info().unwrap();
+    if info.type_ != FileType::Dir || info.size <= dentry.entry_id() { return -1; }
+    let name = file.lock().get_entry(dentry.entry_id());
+    if name.is_err() { return -1; }
+    let name = name.unwrap();
+    dentry.set_name(name.as_str());
+    0
+}
+
 fn sys_dup(fd1: usize, fd2: usize) -> i32 {
     info!("dup: {} {}", fd1, fd2);
     let file = process().files.get(&fd1);
@@ -271,6 +289,26 @@ impl VfsFlags {
     }
 }
 
+#[repr(C)]
+struct DirEntry {
+    offset: u32,
+    name: [u8; 256],
+}
+
+impl DirEntry {
+    fn check(&self) -> bool {
+        self.offset % 256 == 0
+    }
+    fn entry_id(&self) -> usize {
+        (self.offset / 256) as usize
+    }
+    fn set_name(&mut self, name: &str) {
+        self.name[..name.len()].copy_from_slice(name.as_bytes());
+        self.name[name.len()] = 0;
+        self.offset += 256;
+    }
+}
+
 #[repr(C)]
 struct Stat {
     /// protection mode and file type