revert incorrect keepalive behaviour from 0.51.0

Author: Eugeny

russh/src/client/encrypted.rs

@@ -562,7 +562,6 @@ impl Session {
                         if wants_reply == 1 {
                             trace!("Received keep alive message: {req:?}",);
                             self.common.wants_reply = false;
-                            self.common.ever_received_keepalive = true;
                             push_packet!(enc.write, enc.write.push(msg::REQUEST_SUCCESS));
                         } else {
                             warn!("Received keepalive without reply request!");

russh/src/client/mod.rs

@@ -889,7 +889,6 @@ where
             alive_timeouts: 0,
             received_data: false,
             remote_sshid: sshid.into(),
-            ever_received_keepalive: false,
         },
         session_receiver,
         session_sender,
@@ -1075,7 +1074,7 @@ impl Session {
                     reading.set(start_reading(stream_read, buffer, opening_cipher));
                 }
                 () = &mut keepalive_timer => {
-                    if self.common.config.keepalive_max != 0 && self.common.alive_timeouts > self.common.config.keepalive_max && self.common.ever_received_keepalive {
+                    if self.common.config.keepalive_max != 0 && self.common.alive_timeouts > self.common.config.keepalive_max {
                         debug!("Timeout, server not responding to keepalives");
                         return Err(crate::Error::KeepaliveTimeout.into());
                     }

russh/src/server/mod.rs

@@ -992,7 +992,6 @@ async fn read_ssh_id<R: AsyncRead + Unpin>(
         alive_timeouts: 0,
         received_data: false,
         remote_sshid: sshid.into(),
-        ever_received_keepalive: false,
     };
     Ok(session)
 }

russh/src/session.rs

@@ -72,7 +72,6 @@ pub(crate) struct CommonSession<Config> {
     pub strict_kex: bool,
     pub alive_timeouts: usize,
     pub received_data: bool,
-    pub ever_received_keepalive: bool,
 }
 
 impl<C> Debug for CommonSession<C> {