Remove the shim kernel crate

kernel/src/net/socket/ip/stream/util.rs

@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: MPL-2.0
+
+use crate::prelude::*;
+
+#[derive(Debug, Clone, Copy, CopyGetters, Setters)]
+#[get_copy = "pub"]
+#[set = "pub"]
+pub struct TcpOptionSet {
+    no_delay: bool,
+    congestion: CongestionControl,
+    maxseg: u32,
+    window_clamp: u32,
+}
+
+pub const DEFAULT_MAXSEG: u32 = 536;
+pub const DEFAULT_WINDOW_CLAMP: u32 = 0x8000_0000;
+
+impl TcpOptionSet {
+    pub fn new() -> Self {
+        Self {
+            no_delay: false,
+            congestion: CongestionControl::Reno,
+            maxseg: DEFAULT_MAXSEG,
+            window_clamp: DEFAULT_WINDOW_CLAMP,
+        }
+    }
+}
+
+impl Default for TcpOptionSet {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+pub enum CongestionControl {
+    Reno,
+    Cubic,
+}
+
+impl CongestionControl {
+    const RENO: &'static str = "reno";
+    const CUBIC: &'static str = "cubic";
+
+    pub fn new(name: &str) -> Result<Self> {
+        let congestion = match name {
+            Self::RENO => Self::Reno,
+            Self::CUBIC => Self::Cubic,
+            _ => return_errno_with_message!(Errno::EINVAL, "unsupported congestion name"),
+        };
+
+        Ok(congestion)
+    }
+
+    pub fn name(&self) -> &'static str {
+        match self {
+            Self::Reno => Self::RENO,
+            Self::Cubic => Self::CUBIC,
+        }
+    }
+}