Fix typos and add utils

services/libs/jinux-std/src/fs/file_handle.rs

@@ -2,6 +2,7 @@
 
 use crate::events::Observer;
 use crate::fs::utils::{AccessMode, IoEvents, IoctlCmd, Metadata, Poller, SeekFrom, StatusFlags};
+use crate::net::socket::Socket;
 use crate::prelude::*;
 
 use core::any::Any;
@@ -67,6 +68,10 @@ pub trait FileLike: Send + Sync + Any {
     ) -> Result<Weak<dyn Observer<IoEvents>>> {
         return_errno_with_message!(Errno::EINVAL, "unregister_observer is not supported")
     }
+
+    fn as_socket(&self) -> Option<&dyn Socket> {
+        None
+    }
 }
 
 impl dyn FileLike {

services/libs/jinux-std/src/fs/file_table.rs

@@ -1,4 +1,5 @@
 use crate::events::{Events, Observer, Subject};
+use crate::net::socket::Socket;
 use crate::prelude::*;
 
 use core::cell::Cell;
@@ -101,6 +102,12 @@ impl FileTable {
             .ok_or(Error::with_message(Errno::EBADF, "fd not exits"))
     }
 
+    pub fn get_socket(&self, sockfd: FileDescripter) -> Result<&dyn Socket> {
+        self.get_file(sockfd)?
+            .as_socket()
+            .ok_or_else(|| Error::with_message(Errno::ENOTSOCK, "the fd is not a socket"))
+    }
+
     pub fn get_entry(&self, fd: FileDescripter) -> Result<&FileTableEntry> {
         self.table
             .get(fd as usize)

services/libs/jinux-std/src/fs/utils/poll.rs

@@ -8,6 +8,7 @@ use keyable_arc::KeyableWeak;
 
 /// A pollee maintains a set of active events, which can be polled with
 /// pollers or be monitored with observers.
+#[derive(Clone)]
 pub struct Pollee {
     inner: Arc<PolleeInner>,
 }