Patch socketpair (#576)

* 将sockets分成inet和unix域
- 添加File端点
- 添加SocketPair trait并将Socket trait中的pair相关方法移动
- 添加对SockAddrUn的处理

* 精简SocketHandleItem

* 重构socketpair相关逻辑
- 将File端点换成Inode端点
- 尝试使用SocketInode进行socketpair(未成功)


* 将SocketPair trait合并到Socket trait中，去除downcast

user/apps/test_socket/src/main.rs

@@ -0,0 +1,21 @@
+mod test_unix_stream;
+mod test_unix_stream_pair;
+
+use test_unix_stream::test_unix_stream;
+use test_unix_stream_pair::test_unix_stream_pair;
+
+fn main() -> std::io::Result<()> {
+    if let Err(e) = test_unix_stream() {
+        println!("[ fault ] test_unix_stream, err: {}", e);
+    } else {
+        println!("[success] test_unix_stream");
+    }
+
+    if let Err(e) = test_unix_stream_pair() {
+        println!("[ fault ] test_unix_stream_pair, err: {}", e);
+    } else {
+        println!("[success] test_unix_stream_pair");
+    }
+
+    Ok(())
+}

user/apps/test_socket/src/test_unix_stream.rs

@@ -0,0 +1,42 @@
+use std::io::{Error, Read, Write};
+use std::os::unix::net::{UnixListener, UnixStream};
+use std::thread;
+use std::{fs, str};
+
+const SOCKET_PATH: &str = "/test.socket";
+const MSG: &str = "Hello, unix stream socket!";
+
+fn client() -> std::io::Result<()> {
+    // 连接到服务器
+    let mut stream = UnixStream::connect(SOCKET_PATH)?;
+    // 发送消息到服务器
+    stream.write_all(MSG.as_bytes())?;
+    Ok(())
+}
+
+pub fn test_unix_stream() -> std::io::Result<()> {
+    println!("unix stream socket path: {}", SOCKET_PATH);
+    // 删除可能已存在的socket文件
+    fs::remove_file(&SOCKET_PATH).ok();
+    // 创建Unix域监听socket
+    let listener = UnixListener::bind(SOCKET_PATH)?;
+
+    let client_thread = thread::spawn(move || client());
+
+    // 监听并接受连接
+    let (mut stream, _) = listener.accept().expect("listen error");
+
+    let mut buffer = [0; 1024];
+    let nbytes = stream.read(&mut buffer).expect("read error");
+    let received_msg = str::from_utf8(&buffer[..nbytes]).unwrap();
+
+    client_thread.join().ok();
+
+    fs::remove_file(&SOCKET_PATH).ok();
+
+    if received_msg == MSG {
+        Ok(())
+    } else {
+        Err(Error::from_raw_os_error(-1))
+    }
+}

user/apps/test_socket/src/test_unix_stream_pair.rs

@@ -0,0 +1,21 @@
+use std::io::{Error, Read, Write};
+use std::os::unix::net::UnixStream;
+use std::str;
+
+const MSG: &str = "Hello, unix stream socketpair!";
+
+pub fn test_unix_stream_pair() -> std::io::Result<()> {
+    let (mut sock0, mut sock1) = UnixStream::pair()?;
+
+    sock1.write_all(MSG.as_bytes())?;
+
+    let mut buffer = [0; 1024];
+    let nbytes = sock0.read(&mut buffer).expect("read error");
+    let received_msg = str::from_utf8(&buffer[..nbytes]).unwrap();
+
+    if received_msg == MSG {
+        Ok(())
+    } else {
+        Err(Error::from_raw_os_error(-1))
+    }
+}