fix(rustls): read buffer if we received a bufffer full error instead …

…of processing new packets

Signed-off-by: Florentin Dubois <[email protected]>

lib/src/socket.rs

@@ -181,6 +181,7 @@ impl SocketHandler for FrontRustls {
                 break;
             }
 
+            let mut is_rustls_backpressuring = false;
             match self.session.read_tls(&mut self.stream) {
                 Ok(0) => {
                     can_read = false;
@@ -196,6 +197,12 @@ impl SocketHandler for FrontRustls {
                     | ErrorKind::BrokenPipe => {
                         is_closed = true;
                     }
+                    // According to rustls comment here https://github.com/rustls/rustls/blob/main/rustls/src/conn.rs#L482-L500,
+                    // [`ErrorKind::Other`] error signal that the buffer is full, we need to read it before processing new packets.
+                    ErrorKind::Other => {
+                        warn!("rustls buffer is full, we will consume it, before processing new incoming packets, to mitigate this issue, you could try to increase the buffer size, {:?}", e);
+                        is_rustls_backpressuring = true;
+                    }
                     _ => {
                         error!("could not read TLS stream from socket: {:?}", e);
                         is_error = true;
@@ -204,10 +211,12 @@ impl SocketHandler for FrontRustls {
                 },
             }
 
-            if let Err(e) = self.session.process_new_packets() {
-                error!("could not process read TLS packets: {:?}", e);
-                is_error = true;
-                break;
+            if !is_rustls_backpressuring {
+                if let Err(e) = self.session.process_new_packets() {
+                    error!("could not process read TLS packets: {:?}", e);
+                    is_error = true;
+                    break;
+                }
             }
 
             while !self.session.wants_read() {