If a TCP FIN|ACK also ACKs our FIN, transition to TIME-WAIT.

This commit is contained in:
whitequark 2017-01-25 03:58:03 +00:00
parent f6d542b739
commit bef01740a7
1 changed files with 36 additions and 1 deletions

View File

@ -778,7 +778,17 @@ impl<'a> TcpSocket<'a> {
// We could've sent data before the FIN, so only remove FIN from the sequence
// space if all of that data is acknowledged.
if sent_fin && self.tx_buffer.len() + 1 == ack_len {
ack_len -= 1
ack_len -= 1;
net_trace!("[{}]{}:{}: received ACK of FIN",
self.debug_id, self.local_endpoint, self.remote_endpoint);
// If we've just switched from the FIN-WAIT-1 state to the CLOSING state
// because we've received a FIN, and the same packet simultaneously acknowledges
// the FIN we've sent, this is our only opportunity to move to the TIME-WAIT state.
match self.state {
State::Closing =>
self.set_state(State::TimeWait),
_ => ()
}
}
if ack_len > 0 {
net_trace!("[{}]{}:{}: tx buffer: dequeueing {} octets (now {})",
@ -1957,6 +1967,31 @@ mod test {
recv!(s, []);
}
#[test]
fn test_simultaneous_close_combined_fin_ack() {
let mut s = socket_established();
s.close();
assert_eq!(s.state, State::FinWait1);
recv!(s, [TcpRepr {
control: TcpControl::Fin,
seq_number: LOCAL_SEQ + 1,
ack_number: Some(REMOTE_SEQ + 1),
..RECV_TEMPL
}]);
send!(s, TcpRepr {
control: TcpControl::Fin,
seq_number: REMOTE_SEQ + 1,
ack_number: Some(LOCAL_SEQ + 1 + 1),
..SEND_TEMPL
});
assert_eq!(s.state, State::TimeWait);
recv!(s, [TcpRepr {
seq_number: LOCAL_SEQ + 1 + 1,
ack_number: Some(REMOTE_SEQ + 1 + 1),
..RECV_TEMPL
}]);
}
#[test]
fn test_fin_with_data() {
let mut s = socket_established();