Remove the shim kernel crate

kernel/src/syscall/getsockopt.rs

@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: MPL-2.0
+
+use super::SyscallReturn;
+use crate::{
+    fs::file_table::FileDesc,
+    prelude::*,
+    util::net::{get_socket_from_fd, new_raw_socket_option, CSocketOptionLevel},
+};
+
+pub fn sys_getsockopt(
+    sockfd: FileDesc,
+    level: i32,
+    optname: i32,
+    optval: Vaddr,
+    optlen_addr: Vaddr,
+    ctx: &Context,
+) -> Result<SyscallReturn> {
+    let level = CSocketOptionLevel::try_from(level)?;
+    if optval == 0 || optlen_addr == 0 {
+        return_errno_with_message!(Errno::EINVAL, "optval or optlen_addr is null pointer");
+    }
+    let user_space = ctx.get_user_space();
+
+    let optlen: u32 = user_space.read_val(optlen_addr)?;
+    debug!("level = {level:?}, sockfd = {sockfd}, optname = {optname:?}, optlen = {optlen}");
+
+    let socket = get_socket_from_fd(sockfd)?;
+
+    let mut raw_option = new_raw_socket_option(level, optname)?;
+
+    debug!("raw option: {:?}", raw_option);
+
+    socket.get_option(raw_option.as_sock_option_mut())?;
+
+    let write_len = raw_option.write_to_user(optval, optlen)?;
+
+    user_space.write_val(optlen_addr, &(write_len as u32))?;
+
+    Ok(SyscallReturn::Return(0))
+}