vsock: Properly shutdown and release UNIX proxy

When a vsock communicating with a UNIX proxy shuts down, the connection
between the UNIX proxy and communicating UNIX socket must also be
shutdown. The UNIX proxy must also remove itself from the proxy map
when released.

Signed-off-by: Tyler Fanelli <tfanelli@redhat.com>

src/devices/src/virtio/vsock/unix.rs

@@ -11,8 +11,8 @@ use std::sync::{Arc, Mutex};
 
 use nix::fcntl::{fcntl, FcntlArg, OFlag};
 use nix::sys::socket::{
-    accept, connect, recv, send, setsockopt, socket, sockopt, AddressFamily, MsgFlags, SockFlag,
-    SockType, UnixAddr,
+    accept, connect, recv, send, setsockopt, shutdown, socket, sockopt, AddressFamily, MsgFlags,
+    Shutdown, SockFlag, SockType, UnixAddr,
 };
 use nix::unistd::close;
 
@@ -429,12 +429,38 @@ impl Proxy for UnixProxy {
         todo!();
     }
 
-    fn shutdown(&mut self, _pkt: &VsockPacket) {
-        todo!();
+    fn shutdown(&mut self, pkt: &VsockPacket) {
+        let recv_off = pkt.flags() & uapi::VSOCK_FLAGS_SHUTDOWN_RCV != 0;
+        let send_off = pkt.flags() & uapi::VSOCK_FLAGS_SHUTDOWN_SEND != 0;
+
+        let how = if recv_off && send_off {
+            Shutdown::Both
+        } else if recv_off {
+            Shutdown::Read
+        } else {
+            Shutdown::Write
+        };
+
+        if let Err(e) = shutdown(self.fd, how) {
+            warn!("error sending shutdown to socket: {}", e);
+        }
     }
 
     fn release(&mut self) -> ProxyUpdate {
-        todo!();
+        debug!(
+            "release: id={}, tx_cnt={}, last_tx_cnt={}",
+            self.id, self.tx_cnt, self.last_tx_cnt_sent
+        );
+        let remove_proxy = if self.status == ProxyStatus::Listening {
+            ProxyRemoval::Immediate
+        } else {
+            ProxyRemoval::Deferred
+        };
+
+        ProxyUpdate {
+            remove_proxy,
+            ..Default::default()
+        }
     }
 
     fn process_event(&mut self, evset: EventSet) -> ProxyUpdate {