renet/renet
renet
/
renet
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Implement TCP TIME-WAIT timeouts.

This commit is contained in:
whitequark 2017-04-21 16:01:49 +00:00
parent 8087bf3755
commit 73bb4b8593
2 changed files with 56 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
README.md
View File

@ -55,6 +55,7 @@ The TCP protocol is supported over IPv4. Server and client sockets are supported
* Multiple packets will be transmitted without waiting for an acknowledgement.
* Lost packets will be retransmitted with exponential backoff, starting at
a fixed delay of 100 ms.
* After arriving at the TIME-WAIT state, sockets will close after a fixed delay of 10 s.
* TCP urgent pointer is **not** supported; any urgent octets will be received alongside
data octets.
* Reassembly of out-of-order segments is **not** supported.

60
src/socket/tcp.rs
View File

@ -253,13 +253,17 @@ pub struct TcpSocket<'a> {
remote_win_len: usize,
/// The maximum number of data octets that the remote side may receive.
remote_mss: usize,
/// The retransmit timeout.
retransmit: Retransmit,
/// The TIME-WAIT timeout.
time_wait_since: u64,
rx_buffer: SocketBuffer<'a>,
tx_buffer: SocketBuffer<'a>,
debug_id: usize
}
const DEFAULT_MSS: usize = 536;
const TIME_WAIT_TIMEOUT: u64 = 10_000;
impl<'a> TcpSocket<'a> {
/// Create a socket using the given buffers.
@ -283,6 +287,7 @@ impl<'a> TcpSocket<'a> {
remote_win_len: 0,
remote_mss: DEFAULT_MSS,
retransmit: Retransmit::new(),
time_wait_since: 0,
tx_buffer: tx_buffer.into(),
rx_buffer: rx_buffer.into(),
debug_id: 0
@ -320,6 +325,7 @@ impl<'a> TcpSocket<'a> {
}
fn reset(&mut self) {
self.state = State::Closed;
self.listen_address = IpAddress::default();
self.local_endpoint = IpEndpoint::default();
self.remote_endpoint = IpEndpoint::default();
@ -624,7 +630,7 @@ impl<'a> TcpSocket<'a> {
}
/// See [Socket::process](enum.Socket.html#method.process).
pub fn process(&mut self, _timestamp: u64, ip_repr: &IpRepr,
pub fn process(&mut self, timestamp: u64, ip_repr: &IpRepr,
payload: &[u8]) -> Result<(), Error> {
if self.state == State::Closed { return Err(Error::Rejected) }
@ -723,6 +729,10 @@ impl<'a> TcpSocket<'a> {
// of that, make sure we send the acknowledgement again.
self.remote_last_ack = next_remote_seq - 1;
self.retransmit.reset();
// If we're in the TIME-WAIT state, restart the TIME-WAIT timeout.
if self.state == State::TimeWait {
self.time_wait_since = timestamp;
}
return Err(Error::Dropped)
}
}
@ -842,10 +852,12 @@ impl<'a> TcpSocket<'a> {
}
}
// FIN packets in FIN-WAIT-1 state change it to CLOSING.
// FIN packets in FIN-WAIT-1 state change it to CLOSING, or to TIME-WAIT
// if they also acknowledge our FIN.
(State::FinWait1, TcpRepr { control: TcpControl::Fin, .. }) => {
self.remote_seq_no += 1;
if ack_of_fin {
self.time_wait_since = timestamp;
self.set_state(State::TimeWait);
} else {
self.set_state(State::Closing);
@ -856,6 +868,7 @@ impl<'a> TcpSocket<'a> {
// FIN packets in FIN-WAIT-2 state change it to TIME-WAIT.
(State::FinWait2, TcpRepr { control: TcpControl::Fin, .. }) => {
self.remote_seq_no += 1;
self.time_wait_since = timestamp;
self.set_state(State::TimeWait);
self.retransmit.reset();
}
@ -863,6 +876,7 @@ impl<'a> TcpSocket<'a> {
// ACK packets in CLOSING state change it to TIME-WAIT.
(State::Closing, TcpRepr { control: TcpControl::None, .. }) => {
if ack_of_fin {
self.time_wait_since = timestamp;
self.set_state(State::TimeWait);
} else {
self.retransmit.reset();
@ -954,6 +968,15 @@ impl<'a> TcpSocket<'a> {
return result
}
if self.state == State::TimeWait {
if timestamp >= self.time_wait_since + TIME_WAIT_TIMEOUT {
net_trace!("[{}]{}:{}: TIME-WAIT timeout",
self.debug_id, self.local_endpoint, self.remote_endpoint);
self.reset();
return Err(Error::Exhausted)
}
}
if self.retransmit.may_send_old(timestamp) {
// The retransmit timer has expired, so assume all in-flight data that
// has not been acknowledged is lost.
@ -1234,7 +1257,7 @@ mod test {
($socket:ident, $repr:expr, $result:expr) =>
(send!($socket, time 0, $repr, $result));
($socket:ident, time $time:expr, $repr:expr) =>
(send!($socket, time 0, $repr, Ok(())));
(send!($socket, time $time, $repr, Ok(())));
($socket:ident, time $time:expr, $repr:expr, $result:expr) =>
(assert_eq!(send(&mut $socket, $time, &$repr), $result));
}
@ -1262,6 +1285,7 @@ mod test {
assert_eq!(s1.remote_last_seq, s2.remote_last_seq, "remote_last_seq");
assert_eq!(s1.remote_last_ack, s2.remote_last_ack, "remote_last_ack");
assert_eq!(s1.remote_win_len, s2.remote_win_len, "remote_win_len");
assert_eq!(s1.time_wait_since, s2.time_wait_since, "time_wait_since");
if $retransmit {
assert_eq!(s1.retransmit, s2.retransmit, "retransmit");
} else {
@ -1872,7 +1896,7 @@ mod test {
#[test]
fn test_fin_wait_2_fin() {
let mut s = socket_fin_wait_2();
send!(s, TcpRepr {
send!(s, time 1_000, TcpRepr {
control: TcpControl::Fin,
seq_number: REMOTE_SEQ + 1,
ack_number: Some(LOCAL_SEQ + 1 + 1),
@ -1908,7 +1932,7 @@ mod test {
ack_number: Some(REMOTE_SEQ + 1 + 1),
..RECV_TEMPL
}]);
send!(s, TcpRepr {
send!(s, time 1_000, TcpRepr {
seq_number: REMOTE_SEQ + 1 + 1,
ack_number: Some(LOCAL_SEQ + 1 + 1),
..SEND_TEMPL
@ -1934,6 +1958,7 @@ mod test {
if from_closing {
s.remote_last_ack = REMOTE_SEQ + 1 + 1;
}
s.time_wait_since = 1_000;
s
}
@ -1960,6 +1985,31 @@ mod test {
assert_eq!(s.state, State::TimeWait);
}
#[test]
fn test_time_wait_retransmit() {
let mut s = socket_time_wait(false);
send!(s, time 5_000, TcpRepr {
control: TcpControl::Fin,
seq_number: REMOTE_SEQ + 1,
ack_number: Some(LOCAL_SEQ + 1 + 1),
..SEND_TEMPL
}, Err(Error::Dropped));
assert_eq!(s.time_wait_since, 5_000);
}
#[test]
fn test_time_wait_timeout() {
let mut s = socket_time_wait(false);
recv!(s, [TcpRepr {
seq_number: LOCAL_SEQ + 1 + 1,
ack_number: Some(REMOTE_SEQ + 1 + 1),
..RECV_TEMPL
}]);
assert_eq!(s.state, State::TimeWait);
recv!(s, time 60_000, Err(Error::Exhausted));
assert_eq!(s.state, State::Closed);
}
// =========================================================================================//
// Tests for the CLOSE-WAIT state.
// =========================================================================================//