From 96ac0b2b7ebcc829f79e71d8d1a22105236a0af1 Mon Sep 17 00:00:00 2001
From: Ben Pope <ben@redpanda.com>
Date: Thu, 22 Jun 2023 21:03:16 +0100
Subject: [PATCH] net: ss::nested_exception might be a disconnect_exception

Look through an ss::nested_exception to see if it's a
`disconnect_exception`.

Fixes #11617

Signed-off-by: Ben Pope <ben@redpanda.com>
(cherry picked from commit 2e10dcb6cd3c5f6eab865bc01b13b985199330fa)
---
 src/v/net/connection.cc        |  7 +++++
 src/v/net/tests/CMakeLists.txt | 10 +++++++
 src/v/net/tests/connection.cc  | 50 ++++++++++++++++++++++++++++++++++
 3 files changed, 67 insertions(+)
 create mode 100644 src/v/net/tests/connection.cc

diff --git a/src/v/net/connection.cc b/src/v/net/connection.cc
index 792ddd2d5347..96dafc00dd8f 100644
--- a/src/v/net/connection.cc
+++ b/src/v/net/connection.cc
@@ -12,6 +12,8 @@
 #include "net/exceptions.h"
 #include "rpc/service.h"
 
+#include <seastar/core/future.hh>
+
 #include <gnutls/gnutls.h>
 
 namespace net {
@@ -86,6 +88,11 @@ std::optional<ss::sstring> is_disconnect_exception(std::exception_ptr e) {
             return fmt::format("invalid request: {}", e.what());
         }
         return "invalid request";
+    } catch (const ss::nested_exception& e) {
+        if (auto err = is_disconnect_exception(e.inner)) {
+            return err;
+        }
+        return is_disconnect_exception(e.outer);
     } catch (...) {
         // Global catch-all prevents stranded/non-handled exceptional futures.
         // In all other non-explicity handled cases, the exception will not be
diff --git a/src/v/net/tests/CMakeLists.txt b/src/v/net/tests/CMakeLists.txt
index 0fa1e96027f6..6842c65fdf84 100644
--- a/src/v/net/tests/CMakeLists.txt
+++ b/src/v/net/tests/CMakeLists.txt
@@ -29,3 +29,13 @@ rp_test(
         ARGS "-- -c 1"
         LABELS net
 )
+
+rp_test(
+        UNIT_TEST
+        BINARY_NAME net_connection
+        SOURCES
+        connection.cc
+        DEFINITIONS BOOST_TEST_DYN_LINK
+        LIBRARIES v::seastar_testing_main Boost::unit_test_framework v::net
+        LABELS net
+)
diff --git a/src/v/net/tests/connection.cc b/src/v/net/tests/connection.cc
new file mode 100644
index 000000000000..345b2e626182
--- /dev/null
+++ b/src/v/net/tests/connection.cc
@@ -0,0 +1,50 @@
+/*
+ * Copyright 2023 Redpanda Data, Inc.
+ *
+ * Licensed as a Redpanda Enterprise file under the Redpanda Community
+ * License (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * https://github.com/redpanda-data/redpanda/blob/master/licenses/rcl.md
+ */
+
+#include "net/connection.h"
+
+#include <seastar/core/future.hh>
+
+#include <boost/test/auto_unit_test.hpp>
+#include <boost/test/test_tools.hpp>
+
+#include <exception>
+#include <system_error>
+
+BOOST_AUTO_TEST_CASE(test_is_disconnect_error) {
+    auto is_a_de = std::system_error(
+      std::make_error_code(std::errc::broken_pipe));
+    auto not_a_de = std::system_error(
+      std::make_error_code(std::errc::is_a_directory));
+
+    BOOST_CHECK(net::is_disconnect_exception(std::make_exception_ptr(is_a_de))
+                  .has_value());
+
+    BOOST_CHECK(!net::is_disconnect_exception(std::make_exception_ptr(not_a_de))
+                   .has_value());
+
+    BOOST_CHECK(
+      net::is_disconnect_exception(
+        std::make_exception_ptr(ss::nested_exception(
+          std::make_exception_ptr(is_a_de), std::make_exception_ptr(not_a_de))))
+        .has_value());
+
+    BOOST_CHECK(
+      net::is_disconnect_exception(
+        std::make_exception_ptr(ss::nested_exception(
+          std::make_exception_ptr(not_a_de), std::make_exception_ptr(is_a_de))))
+        .has_value());
+
+    BOOST_CHECK(!net::is_disconnect_exception(
+                   std::make_exception_ptr(ss::nested_exception(
+                     std::make_exception_ptr(not_a_de),
+                     std::make_exception_ptr(not_a_de))))
+                   .has_value());
+}