From b0b009c639aa332195a5aa8b647f6f003f234d95 Mon Sep 17 00:00:00 2001
From: Stefan Lankes <slankes@eonerc.rwth-aachen.de>
Date: Sat, 2 Sep 2023 09:28:02 +0200
Subject: [PATCH 1/2] return error also in the closing state

If smoltcp receives a FIN message, the socket changes the state
to the `closing`, but the socket is still active. To close the
socket, the kernel returns a error if the socket is in the
closing state.

The PR should solve issue hermit-os/kernel#880
---
 src/fd/socket/tcp.rs | 76 ++++++++++++++++++++++++++------------------
 1 file changed, 45 insertions(+), 31 deletions(-)

diff --git a/src/fd/socket/tcp.rs b/src/fd/socket/tcp.rs
index eb68974ead..85aa598138 100644
--- a/src/fd/socket/tcp.rs
+++ b/src/fd/socket/tcp.rs
@@ -71,22 +71,28 @@ impl<T> Socket<T> {
 	#[allow(clippy::needless_pass_by_ref_mut)]
 	async fn async_read(&self, buffer: &mut [u8]) -> Result<isize, i32> {
 		future::poll_fn(|cx| {
-			self.with(|socket| {
-				if !socket.is_active() {
-					Poll::Ready(Err(-crate::errno::EIO))
-				} else if socket.can_recv() {
-					Poll::Ready(
-						socket
-							.recv(|data| {
-								let len = core::cmp::min(buffer.len(), data.len());
-								buffer[..len].copy_from_slice(&data[..len]);
-								(len, isize::try_from(len).unwrap())
-							})
-							.map_err(|_| -crate::errno::EIO),
-					)
-				} else {
-					socket.register_recv_waker(cx.waker());
-					Poll::Pending
+			self.with(|socket| match socket.state() {
+				tcp::State::FinWait1
+				| tcp::State::FinWait2
+				| tcp::State::Closed
+				| tcp::State::Closing
+				| tcp::State::CloseWait
+				| tcp::State::TimeWait => Poll::Ready(Err(-crate::errno::EIO)),
+				_ => {
+					if socket.can_recv() {
+						Poll::Ready(
+							socket
+								.recv(|data| {
+									let len = core::cmp::min(buffer.len(), data.len());
+									buffer[..len].copy_from_slice(&data[..len]);
+									(len, isize::try_from(len).unwrap())
+								})
+								.map_err(|_| -crate::errno::EIO),
+						)
+					} else {
+						socket.register_recv_waker(cx.waker());
+						Poll::Pending
+					}
 				}
 			})
 		})
@@ -99,21 +105,29 @@ impl<T> Socket<T> {
 		while pos < buffer.len() {
 			let n = future::poll_fn(|cx| {
 				self.with(|socket| {
-					if !socket.is_active() {
-						Poll::Ready(Err(-crate::errno::EIO))
-					} else if socket.can_send() {
-						Poll::Ready(
-							socket
-								.send_slice(&buffer[pos..])
-								.map_err(|_| -crate::errno::EIO),
-						)
-					} else if pos > 0 {
-						// we already send some data => return 0 as signal to stop the
-						// async write
-						Poll::Ready(Ok(0))
-					} else {
-						socket.register_send_waker(cx.waker());
-						Poll::Pending
+					match socket.state() {
+						tcp::State::FinWait1
+						| tcp::State::FinWait2
+						| tcp::State::Closed
+						| tcp::State::Closing
+						| tcp::State::CloseWait
+						| tcp::State::TimeWait => Poll::Ready(Err(-crate::errno::EIO)),
+						_ => {
+							if socket.can_send() {
+								Poll::Ready(
+									socket
+										.send_slice(&buffer[pos..])
+										.map_err(|_| -crate::errno::EIO),
+								)
+							} else if pos > 0 {
+								// we already send some data => return 0 as signal to stop the
+								// async write
+								Poll::Ready(Ok(0))
+							} else {
+								socket.register_send_waker(cx.waker());
+								Poll::Pending
+							}
+						}
 					}
 				})
 			})

From 73de27b6df924d2dba20092fbd7fdfcd70e7b0a7 Mon Sep 17 00:00:00 2001
From: Stefan Lankes <slankes@eonerc.rwth-aachen.de>
Date: Sun, 3 Sep 2023 20:34:48 +0200
Subject: [PATCH 2/2] read should return 0 if socket is in state closed/closing

---
 src/fd/socket/tcp.rs | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/src/fd/socket/tcp.rs b/src/fd/socket/tcp.rs
index 85aa598138..01cb4f9069 100644
--- a/src/fd/socket/tcp.rs
+++ b/src/fd/socket/tcp.rs
@@ -72,11 +72,12 @@ impl<T> Socket<T> {
 	async fn async_read(&self, buffer: &mut [u8]) -> Result<isize, i32> {
 		future::poll_fn(|cx| {
 			self.with(|socket| match socket.state() {
+				tcp::State::Closed | tcp::State::Closing | tcp::State::CloseWait => {
+					Poll::Ready(Ok(0))
+				}
 				tcp::State::FinWait1
 				| tcp::State::FinWait2
-				| tcp::State::Closed
-				| tcp::State::Closing
-				| tcp::State::CloseWait
+				| tcp::State::Listen
 				| tcp::State::TimeWait => Poll::Ready(Err(-crate::errno::EIO)),
 				_ => {
 					if socket.can_recv() {
@@ -106,11 +107,12 @@ impl<T> Socket<T> {
 			let n = future::poll_fn(|cx| {
 				self.with(|socket| {
 					match socket.state() {
+						tcp::State::Closed | tcp::State::Closing | tcp::State::CloseWait => {
+							Poll::Ready(Ok(0))
+						}
 						tcp::State::FinWait1
 						| tcp::State::FinWait2
-						| tcp::State::Closed
-						| tcp::State::Closing
-						| tcp::State::CloseWait
+						| tcp::State::Listen
 						| tcp::State::TimeWait => Poll::Ready(Err(-crate::errno::EIO)),
 						_ => {
 							if socket.can_send() {