From 121f9febc759a8ad2eb16ce04a59c8058a58e6c7 Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Thu, 2 Mar 2023 17:56:27 -0800
Subject: [PATCH] ircd::net: Add TCP_CORK support to socket options interface.

---
 include/ircd/net/sock_opts.h |  3 +++
 ircd/net.cc                  | 50 ++++++++++++++++++++++++++++++++++++
 2 files changed, 53 insertions(+)

diff --git a/include/ircd/net/sock_opts.h b/include/ircd/net/sock_opts.h
index 6b251ad8b..14eb72f1c 100644
--- a/include/ircd/net/sock_opts.h
+++ b/include/ircd/net/sock_opts.h
@@ -17,6 +17,7 @@ namespace ircd::net
 
 	bool v6only(const socket &);
 	bool blocking(const socket &);
+	bool nopush(const socket &);
 	bool nodelay(const socket &);
 	bool quickack(const socket &);
 	bool keepalive(const socket &);
@@ -30,6 +31,7 @@ namespace ircd::net
 	// returns true if supported, false if unsupported; failures will throw.
 	bool v6only(socket &, const bool &);
 	bool blocking(socket &, const bool &);
+	bool nopush(socket &, const bool &);
 	bool nodelay(socket &, const bool &);
 	bool quickack(socket &, const bool &);
 	bool keepalive(socket &, const bool &);
@@ -57,6 +59,7 @@ struct ircd::net::sock_opts
 
 	int8_t v6only { IGN };
 	int8_t blocking { IGN };             // Simulates blocking behavior
+	int8_t nopush { IGN };
 	int8_t nodelay { IGN };
 	int8_t quickack { IGN };
 	int8_t keepalive { IGN };
diff --git a/ircd/net.cc b/ircd/net.cc
index ab53cc654..9b4e0172d 100644
--- a/ircd/net.cc
+++ b/ircd/net.cc
@@ -825,6 +825,7 @@ ircd::net::open(socket &socket,
 ircd::net::sock_opts::sock_opts(const socket &socket)
 :v6only{net::v6only(socket)}
 ,blocking{net::blocking(socket)}
+,nopush{net::nopush(socket)}
 ,nodelay{net::nodelay(socket)}
 ,quickack{net::quickack(socket)}
 ,keepalive{net::keepalive(socket)}
@@ -848,6 +849,9 @@ ircd::net::set(socket &socket,
 	if(opts.blocking != opts.IGN)
 		net::blocking(socket, opts.blocking);
 
+	if(opts.nopush != opts.IGN)
+		net::nopush(socket, opts.nopush);
+
 	if(opts.nodelay != opts.IGN)
 		net::nodelay(socket, opts.nodelay);
 
@@ -1056,6 +1060,29 @@ ircd::net::nodelay(socket &socket,
 	return true;
 }
 
+bool
+ircd::net::nopush(socket &socket,
+                  const bool &b)
+#if defined(TCP_CORK) && defined(SOL_SOCKET)
+{
+	ip::tcp::socket &sd(socket);
+	const auto &fd
+	{
+		sd.lowest_layer().native_handle()
+	};
+
+	const int val(b);
+	const socklen_t len(sizeof(val));
+	syscall(::setsockopt, fd, SOL_SOCKET, TCP_CORK, &val, len);
+	return true;
+}
+#else
+{
+	#warning "TCP_CORK is not defined on this platform."
+	return false;
+}
+#endif
+
 /// Toggles the behavior of non-async asio calls.
 ///
 /// This option affects very little in practice and only sets a flag in
@@ -1207,6 +1234,29 @@ ircd::net::nodelay(const socket &socket)
 	return option.value();
 }
 
+bool
+ircd::net::nopush(const socket &socket)
+#if defined(TCP_CORK) && defined(SOL_SOCKET)
+{
+	const ip::tcp::socket &sd(socket);
+	const auto &fd
+	{
+		mutable_cast(sd).lowest_layer().native_handle()
+	};
+
+	uint32_t ret;
+	socklen_t len(sizeof(ret));
+	syscall(::getsockopt, fd, SOL_SOCKET, TCP_CORK, &ret, &len);
+	assert(len <= sizeof(ret));
+	return ret;
+}
+#else
+{
+	#warning "TCP_CORK is not defined on this platform."
+	return false;
+}
+#endif
+
 bool
 ircd::net::blocking(const socket &socket)
 {