implemented socket pair

driver/io-unix.cpp

@@ -247,6 +247,24 @@ Conveyor<Own<NetworkAddress>> UnixNetwork::parseAddress(const std::string &path,
 		event_port, path, port_hint, std::move(addresses))};
 }
 
+ErrorOr<SocketPair> UnixNetwork::socketPair() {
+	int sv[2];
+
+	int rc = ::socketpair(AF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
+						  0, sv);
+	if (rc < 0) {
+		return criticalError("Failed to create");
+	}
+
+	SocketPair socket_pair;
+	socket_pair.stream[0] =
+		heap<UnixIoStream>(event_port, sv[0], 0, EPOLLIN | EPOLLOUT);
+	socket_pair.stream[1] =
+		heap<UnixIoStream>(event_port, sv[1], 0, EPOLLIN | EPOLLOUT);
+
+	return socket_pair;
+}
+
 UnixIoProvider::UnixIoProvider(UnixEventPort &port_ref, Own<EventPort> port)
 	: event_port{port_ref}, event_loop{std::move(port)}, unix_network{
 															 port_ref} {}

driver/io-unix.h

@@ -419,6 +419,8 @@ public:
 
 	Conveyor<Own<NetworkAddress>> parseAddress(const std::string &address,
 											   uint16_t port_hint = 0) override;
+
+	ErrorOr<SocketPair> socketPair() override;
 };
 
 class UnixIoProvider final : public IoProvider {

source/forstio/io.h

@@ -92,6 +92,11 @@ public:
 	virtual Conveyor<Own<IoStream>> accept() = 0;
 };
 
+class SocketPair {
+public:
+	std::array<Own<IoStream>, 2> stream;
+};
+
 class NetworkAddress {
 public:
 	virtual ~NetworkAddress() = default;
@@ -114,6 +119,11 @@ public:
 
 	virtual Conveyor<Own<NetworkAddress>>
 	parseAddress(const std::string &addr, uint16_t port_hint = 0) = 0;
+
+	/**
+	 * Creates an unnamed pair of bidirectional fds
+	 */
+	virtual ErrorOr<SocketPair> socketPair() = 0;
 };
 
 class IoProvider {

source/forstio/tls/tls.cpp

@@ -260,6 +260,10 @@ Conveyor<Own<NetworkAddress>> TlsNetwork::parseAddress(const std::string &addr,
 			});
 }
 
+ErrorOr<SocketPair> TlsNetwork::socketPair(){
+	return criticalError("Unimplemented");
+}
+
 std::optional<Own<TlsNetwork>> setupTlsNetwork(Network &network) {
 	return std::nullopt;
 }

source/forstio/tls/tls.h

@@ -62,6 +62,8 @@ public:
 
 	Conveyor<Own<NetworkAddress>> parseAddress(const std::string &addr,
 											   uint16_t port = 0) override;
+
+	ErrorOr<SocketPair> socketPair() override;
 };
 
 std::optional<Own<TlsNetwork>> setupTlsNetwork(Network &network);

test/io.cpp

@@ -0,0 +1,29 @@
+#include "suite/suite.h"
+
+#include "source/forstio/io.h"
+
+namespace {
+SAW_TEST("Io Socket Pair"){
+	using namespace saw;
+
+	auto err_or_aio = setupAsyncIo();
+	SAW_EXPECT(!err_or_aio.isError(), "Async Io setup failed");
+	AsyncIoContext& aio = err_or_aio.value();
+	WaitScope wait_scope{aio.event_loop};
+
+	SAW_EXPECT(aio.io, "Faulty async io context created");
+	auto err_or_sp = aio.io->network().socketPair();
+	SAW_EXPECT(!err_or_sp.isError(), "Couldn't create socket pair");
+	
+	SocketPair& sp = err_or_sp.value();
+	
+	uint8_t buffer_out[3] = {1,2,3};
+	sp.stream[0]->write(buffer_out,3);
+	uint8_t buffer_in[3];
+	sp.stream[1]->read(buffer_in, 3);
+
+	SAW_EXPECT(buffer_in[0] == 1, "Element 1 failed");
+	SAW_EXPECT(buffer_in[1] == 2, "Element 2 failed");
+	SAW_EXPECT(buffer_in[2] == 3, "Element 3 failed");
+}
+}