From 32f4631bae36001b7a72209835032c9f2c8d6773 Mon Sep 17 00:00:00 2001
From: Raimo Niskanen <raimo@erlang.org>
Date: Thu, 25 Jul 2024 17:51:36 +0200
Subject: [PATCH] Use read_ahead in SSL for KTLS

---
 lib/ssl/src/inet_tls_dist.erl          | 12 +++++++-----
 lib/ssl/src/tls_gen_connection_1_3.erl |  4 ++--
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/lib/ssl/src/inet_tls_dist.erl b/lib/ssl/src/inet_tls_dist.erl
index c93bb2759634..3f46d5663d22 100644
--- a/lib/ssl/src/inet_tls_dist.erl
+++ b/lib/ssl/src/inet_tls_dist.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2011-2023. All Rights Reserved.
+%% Copyright Ericsson AB 2011-2024. All Rights Reserved.
 %%
 %% Licensed under the Apache License, Version 2.0 (the "License");
 %% you may not use this file except in compliance with the License.
@@ -233,7 +233,8 @@ listen(Name, Host) ->
 
 fam_listen(Family, Name, Host) ->
     ForcedOptions =
-        [Family, {active, false}, {packet, 4}, {nodelay, true}],
+        [Family, {active, false}, {packet, 4},
+         {read_ahead, false}, {nodelay, true}],
     ListenFun =
         fun (First, Last, ListenOptions) ->
                 listen_loop(
@@ -342,7 +343,7 @@ accept_one(Family, Socket, NetKernel) ->
     case
         ssl:handshake(
           Socket,
-          trace([{active, false},{packet, 4}|Opts]),
+          trace([{active, false}, {packet, 4}, {read_ahead, false} | Opts]),
           net_kernel:connecttime())
     of
         {ok, SslSocket} ->
@@ -640,7 +641,8 @@ do_setup(
           inet_tcp_dist:merge_options(
             ConnectOptions,
             get_ssl_options(client)),
-          [Family, binary, {active, false}, {packet, 4}, {nodelay, true}],
+          [Family, binary, {active, false}, {packet, 4},
+           {read_ahead, false}, {nodelay, true}],
           [{server_name_indication, Host}]),
     KTLS = proplists:get_value(ktls, Opts, false),
     dist_util:reset_timer(Timer),
@@ -943,7 +945,7 @@ inet_set_ktls(
             inet:setopts(
               Socket,
               [list, {packet, Packet}, {packet_size, PacketSize},
-               {header, Header}, {active, Active}])
+               {read_ahead, false}, {header, Header}, {active, Active}])
         of
             ok ->
                 ok;
diff --git a/lib/ssl/src/tls_gen_connection_1_3.erl b/lib/ssl/src/tls_gen_connection_1_3.erl
index 22df97f066cd..fc9753200221 100644
--- a/lib/ssl/src/tls_gen_connection_1_3.erl
+++ b/lib/ssl/src/tls_gen_connection_1_3.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2022-2023. All Rights Reserved.
+%% Copyright Ericsson AB 2022-2024. All Rights Reserved.
 %%
 %% Licensed under the Apache License, Version 2.0 (the "License");
 %% you may not use this file except in compliance with the License.
@@ -380,7 +380,7 @@ init_max_early_data_size(server) ->
     ssl_config:get_max_early_data_size().
 
 internal_active_n(#{ktls := true}, Socket) ->
-    inet:setopts(Socket, [{packet, ssl_tls}]),
+    inet:setopts(Socket, [{packet, ssl_tls}, {read_ahead, false}]),
     1;
 internal_active_n(#{erl_dist := true}, _) ->
     %% Start with a random number between 1 and ?INTERNAL_ACTIVE_N