From e488dca1245ee9d5f6bf81023a2839fc53b13852 Mon Sep 17 00:00:00 2001
From: Anthony Ramine <nox@nox.paris>
Date: Mon, 31 Jan 2022 11:06:06 +0100
Subject: [PATCH] Don't return shutdown errors during shutdown

---
 tokio-boring/src/lib.rs | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/tokio-boring/src/lib.rs b/tokio-boring/src/lib.rs
index 0de479c3..20315633 100644
--- a/tokio-boring/src/lib.rs
+++ b/tokio-boring/src/lib.rs
@@ -254,6 +254,19 @@ where
                 return Poll::Pending;
             }
             Err(e) => {
+                // If boring returns PROTOCOL_IS_SHUTDOWN then the connection
+                // has already been shutdown and we can just return Ok(()), as
+                // this was exactly what we wanted to do anyway.
+                if e.code() == ErrorCode::SSL {
+                    if let Some(stack) = e.ssl_error() {
+                        if let Some(first) = stack.errors.first() {
+                            if first.code() as i32 == boring_sys::SSL_R_PROTOCOL_IS_SHUTDOWN {
+                                return Poll::Ready(Ok(()));
+                            }
+                        }
+                    }
+                }
+
                 return Poll::Ready(Err(e
                     .into_io_error()
                     .unwrap_or_else(|e| io::Error::new(io::ErrorKind::Other, e))));