Analogous keepalive fixes to the client module

Author: samuela

russh/src/client/encrypted.rs

@@ -605,7 +605,6 @@ impl Session {
                         Ok((client, self))
                     }
                     _ => {
-                        self.common.received_data = false;
                         let wants_reply = r.read_byte().map_err(crate::Error::from)?;
                         if wants_reply == 1 {
                             if let Some(ref mut enc) = self.common.encrypted {
@@ -705,7 +704,6 @@ impl Session {
                         push_packet!(enc.write, enc.write.push(msg::REQUEST_FAILURE))
                     }
                 }
-                self.common.received_data = false;
                 Ok((client, self))
             }
             Some(&msg::CHANNEL_SUCCESS) => {
@@ -828,7 +826,6 @@ impl Session {
                 Ok((client, self))
             }
             _ => {
-                self.common.received_data = false;
                 info!("Unhandled packet: {:?}", buf);
                 Ok((client, self))
             }

russh/src/client/mod.rs

@@ -858,6 +858,14 @@ impl Session {
                 }
             }
 
+            if self.common.received_data {
+                // Reset the number of failed keepalive attempts. We don't
+                // bother detecting keepalive response messages specifically
+                // (OpenSSH_9.6p1 responds with REQUEST_FAILURE aka 82). Instead
+                // we assume that the server is still alive if we receive any
+                // data from it.
+                self.common.alive_timeouts = 0;
+            }
             if self.common.received_data || sent_keepalive {
                 if let (futures::future::Either::Right(ref mut sleep), Some(d)) = (
                     keepalive_timer.as_mut().as_pin_mut(),