From 0c7df119c2b71bed814db7b3da8fc379131433fe Mon Sep 17 00:00:00 2001
From: Kim Alvefur <zash@zash.se>
Date: Wed, 27 Jul 2022 08:16:43 +0200
Subject: [PATCH] feat(tcp): Add support for TCP Fast Open

---
 docs/tcp.html |  4 ++++
 src/options.c | 16 ++++++++++++++++
 src/options.h |  7 +++++++
 src/tcp.c     |  6 ++++++
 4 files changed, 33 insertions(+)

diff --git a/docs/tcp.html b/docs/tcp.html
index 9cc173e..f15196c 100644
--- a/docs/tcp.html
+++ b/docs/tcp.html
@@ -485,6 +485,10 @@ disables the Nagle's algorithm for the connection;</li>
 
 <li> '<tt>tcp-keepintvl</tt>': value for <tt>TCP_KEEPINTVL</tt> Linux only!!</li>
 
+<li> '<tt>tcp-fastopen</tt>': value for <tt>TCP_FASTOPEN</tt> Linux only!!</li>
+
+<li> '<tt>tcp-fastopen-connect</tt>': value for <tt>TCP_FASTOPEN_CONNECT</tt> Linux only!!</li>
+
 <li> '<tt>ipv6-v6only</tt>':
 Setting this option to <tt>true</tt> restricts an <tt>inet6</tt> socket to
 sending and receiving only IPv6 packets.</li>
diff --git a/src/options.c b/src/options.c
index 2b53c67..51ea351 100644
--- a/src/options.c
+++ b/src/options.c
@@ -190,6 +190,22 @@ int opt_set_send_buf_size(lua_State *L, p_socket ps)
 	return opt_setint(L, ps, SOL_SOCKET, SO_SNDBUF);
 }
 
+// /*------------------------------------------------------*/
+
+#ifdef TCP_FASTOPEN
+int opt_set_tcp_fastopen(lua_State *L, p_socket ps)
+{
+    return opt_setint(L, ps, IPPROTO_TCP, TCP_FASTOPEN);
+}
+#endif
+
+#ifdef TCP_FASTOPEN_CONNECT
+int opt_set_tcp_fastopen_connect(lua_State *L, p_socket ps)
+{
+    return opt_setint(L, ps, IPPROTO_TCP, TCP_FASTOPEN_CONNECT);
+}
+#endif
+
 /*------------------------------------------------------*/
 int opt_set_ip6_unicast_hops(lua_State *L, p_socket ps)
 {
diff --git a/src/options.h b/src/options.h
index 41f7337..a4d5d75 100644
--- a/src/options.h
+++ b/src/options.h
@@ -64,6 +64,13 @@ int opt_get_recv_buf_size(lua_State *L, p_socket ps);
 int opt_set_send_buf_size(lua_State *L, p_socket ps);
 int opt_get_send_buf_size(lua_State *L, p_socket ps);
 
+#ifdef TCP_FASTOPEN
+int opt_set_tcp_fastopen(lua_State *L, p_socket ps);
+#endif
+#ifdef TCP_FASTOPEN_CONNECT
+int opt_set_tcp_fastopen_connect(lua_State *L, p_socket ps);
+#endif
+
 int opt_set_ip6_unicast_hops(lua_State *L, p_socket ps);
 int opt_get_ip6_unicast_hops(lua_State *L, p_socket ps);
 
diff --git a/src/tcp.c b/src/tcp.c
index 5876bfb..e24cb0c 100644
--- a/src/tcp.c
+++ b/src/tcp.c
@@ -109,6 +109,12 @@ static t_opt optset[] = {
     {"linger",      opt_set_linger},
 	{"recv-buffer-size",     opt_set_recv_buf_size},
 	{"send-buffer-size",     opt_set_send_buf_size},
+#ifdef TCP_FASTOPEN
+    {"tcp-fastopen", opt_set_tcp_fastopen},
+#endif
+#ifdef TCP_FASTOPEN_CONNECT
+    {"tcp-fastopen-connect", opt_set_tcp_fastopen_connect},
+#endif
     {NULL,          NULL}
 };