Remove the shim kernel crate

kernel/src/util/net/options/tcp.rs

@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: MPL-2.0
+
+use super::RawSocketOption;
+use crate::{
+    impl_raw_socket_option,
+    net::socket::ip::stream::options::{Congestion, MaxSegment, NoDelay, WindowClamp},
+    prelude::*,
+    util::net::options::SocketOption,
+};
+
+/// Sock options for tcp socket.
+///
+/// The raw definition is from https://elixir.bootlin.com/linux/v6.0.9/source/include/uapi/linux/tcp.h#L92
+#[repr(i32)]
+#[derive(Debug, Clone, Copy, TryFromInt)]
+#[allow(non_camel_case_types)]
+#[allow(clippy::upper_case_acronyms)]
+pub enum CTcpOptionName {
+    NODELAY = 1,       /* Turn off Nagle's algorithm. */
+    MAXSEG = 2,        /* Limit MSS */
+    CORK = 3,          /* Never send partially complete segments */
+    KEEPIDLE = 4,      /* Start keeplives after this period */
+    KEEPALIVE = 5,     /* Interval between keepalives */
+    WINDOW_CLAMP = 10, /* Bound advertised window */
+    CONGESTION = 13,   /* Congestion control algorithm */
+}
+
+pub fn new_tcp_option(name: i32) -> Result<Box<dyn RawSocketOption>> {
+    let name = CTcpOptionName::try_from(name)?;
+    match name {
+        CTcpOptionName::NODELAY => Ok(Box::new(NoDelay::new())),
+        CTcpOptionName::CONGESTION => Ok(Box::new(Congestion::new())),
+        CTcpOptionName::MAXSEG => Ok(Box::new(MaxSegment::new())),
+        CTcpOptionName::WINDOW_CLAMP => Ok(Box::new(WindowClamp::new())),
+        _ => todo!(),
+    }
+}
+
+impl_raw_socket_option!(NoDelay);
+impl_raw_socket_option!(Congestion);
+impl_raw_socket_option!(MaxSegment);
+impl_raw_socket_option!(WindowClamp);