From 3035ef07fb45d5eb9cfcbd849aef6caddae2de37 Mon Sep 17 00:00:00 2001
From: whitequark <pz@m-labs.hk>
Date: Fri, 25 Aug 2017 06:27:00 +0000
Subject: [PATCH] Fix a bug that caused TCP packets with PSH bit to be dropped.

---
 src/socket/tcp.rs | 26 ++++++++++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/src/socket/tcp.rs b/src/socket/tcp.rs
index 09e36b7..2547d49 100644
--- a/src/socket/tcp.rs
+++ b/src/socket/tcp.rs
@@ -750,7 +750,7 @@ impl<'a> TcpSocket<'a> {
         if self.state == State::Closed { return Err(Error::Rejected) }
 
         let packet = TcpPacket::new_checked(&payload[..ip_repr.payload_len()])?;
-        let repr = TcpRepr::parse(&packet, &ip_repr.src_addr(), &ip_repr.dst_addr())?;
+        let mut repr = TcpRepr::parse(&packet, &ip_repr.src_addr(), &ip_repr.dst_addr())?;
 
         // If we're still listening for SYNs and the packet has an ACK, it cannot
         // be destined to this socket, but another one may well listen on the same
@@ -901,6 +901,11 @@ impl<'a> TcpSocket<'a> {
             }
         }
 
+        if repr.control == TcpControl::Psh {
+            // We don't care about the PSH flag.
+            repr.control = TcpControl::None;
+        }
+
         // Validate and update the state.
         match (self.state, repr) {
             // RSTs are not accepted in the LISTEN state.
@@ -2891,7 +2896,7 @@ mod test {
     // =========================================================================================//
 
     #[test]
-    fn test_psh() {
+    fn test_psh_transmit() {
         let mut s = socket_established();
         s.remote_win_len = 6;
         s.send_slice(b"abcdef").unwrap();
@@ -2911,4 +2916,21 @@ mod test {
             ..RECV_TEMPL
         }), exact);
     }
+
+    #[test]
+    fn test_psh_receive() {
+        let mut s = socket_established();
+        send!(s, TcpRepr {
+            control:    TcpControl::Psh,
+            seq_number: REMOTE_SEQ + 1,
+            ack_number: Some(LOCAL_SEQ + 1),
+            payload:    &b"abcdef"[..],
+            ..SEND_TEMPL
+        }, Ok(Some(TcpRepr {
+            seq_number: LOCAL_SEQ + 1,
+            ack_number: Some(REMOTE_SEQ + 1 + 6),
+            window_len: 58,
+            ..RECV_TEMPL
+        })));
+    }
 }