From 5630f636cd35e60eff3a49afd91ecf22111eee89 Mon Sep 17 00:00:00 2001
From: Avi Kivity <avi@cloudius-systems.com>
Date: Wed, 10 Sep 2014 10:42:21 +0300
Subject: [PATCH] net: add protcol stack adapter for native stack

This defines adapter classes for converting from the tcp<> class to the
abstractions that applications use.

Still very inefficient due to impedance mismatch between the data types used.
---
 net/stack.cc | 139 +++++++++++++++++++++++++++++++++++++++++++++++++++
 net/stack.hh |  17 +++++++
 2 files changed, 156 insertions(+)
 create mode 100644 net/stack.cc
 create mode 100644 net/stack.hh

diff --git a/net/stack.cc b/net/stack.cc
new file mode 100644
index 0000000000..aa838b00e7
--- /dev/null
+++ b/net/stack.cc
@@ -0,0 +1,139 @@
+/*
+ * Copyright (C) 2014 Cloudius Systems, Ltd.
+ */
+
+#include "stack.hh"
+#include "net.hh"
+#include "ip.hh"
+#include "tcp.hh"
+#include <memory>
+#include <queue>
+
+namespace net {
+
+class native_networking_stack;
+
+template <typename Protocol>
+class native_server_socket_impl;
+
+template <typename Protocol>
+class native_connected_socket_impl;
+
+template <typename Protocol>
+class native_connected_socket_impl : public connected_socket_impl {
+    typename Protocol::connection _conn;
+    class native_data_source_impl;
+    class native_data_sink_impl;
+public:
+    explicit native_connected_socket_impl(typename Protocol::connection conn)
+        : _conn(std::move(conn)) {}
+    virtual input_stream<char> input() override;
+    virtual output_stream<char> output() override;
+};
+
+template <typename Protocol>
+class native_server_socket_impl : public server_socket_impl {
+    Protocol& _proto;
+    uint16_t _port;
+public:
+    native_server_socket_impl(Protocol& proto, uint16_t port, listen_options opt);
+    virtual future<connected_socket, socket_address> accept() override;
+};
+
+class native_networking_stack : public networking_stack {
+    static std::unique_ptr<native_networking_stack> _s;
+    interface _netif;
+    ipv4 _inet;
+    using tcp4 = tcp<ipv4_traits>;
+public:
+    explicit native_networking_stack(std::unique_ptr<device> dev);
+    virtual server_socket listen(socket_address sa, listen_options opt) override;
+    friend class native_server_socket_impl<tcp4>;
+};
+
+native_networking_stack::native_networking_stack(std::unique_ptr<device> dev)
+    : _netif(std::move(dev))
+    , _inet(&_netif) {
+}
+
+template <typename Protocol>
+native_server_socket_impl<Protocol>::native_server_socket_impl(Protocol& proto, uint16_t port, listen_options opt)
+    : _proto(proto), _port(port) {
+}
+
+template <typename Protocol>
+future<connected_socket, socket_address>
+native_server_socket_impl<Protocol>::accept() {
+    return _proto.listen(_port).then([this] (typename Protocol::connection conn) {
+        return make_ready_future<connected_socket, socket_address>(
+                connected_socket(std::make_unique<native_connected_socket_impl<Protocol>>(std::move(conn))),
+                socket_address()); // FIXME: don't fake it
+    });
+}
+
+server_socket
+native_networking_stack::listen(socket_address sa, listen_options opts) {
+    assert(sa.as_posix_sockaddr().sa_family == AF_INET);
+    return server_socket(std::make_unique<native_server_socket_impl<tcp4>>(
+            _inet.get_tcp(), sa.as_posix_sockaddr_in().sin_port, opts));
+}
+
+template <typename Protocol>
+class native_connected_socket_impl<Protocol>::native_data_source_impl final
+    : public data_source_impl {
+    typename Protocol::connection& _conn;
+    size_t _cur_frag = 0;
+    packet _buf;
+public:
+    explicit native_data_source_impl(typename Protocol::connection& conn)
+        : _conn(conn) {}
+    virtual future<temporary_buffer<char>> get() override {
+        if (_cur_frag != _buf.fragments.size()) {
+            auto& f = _buf.fragments[_cur_frag++];
+            return make_ready_future<temporary_buffer<char>>(
+                    temporary_buffer<char>(f.base, f.size,
+                            make_deleter(nullptr, [p = _buf.share()] () mutable {})));
+        }
+        return _conn.wait_for_data().then([this] {
+            _buf = _conn.read();
+            _cur_frag = 0;
+            return get();
+        });
+    }
+};
+
+template <typename Protocol>
+class native_connected_socket_impl<Protocol>::native_data_sink_impl final
+    : public data_sink_impl {
+    typename Protocol::connection& _conn;
+public:
+    explicit native_data_sink_impl(typename Protocol::connection& conn)
+        : _conn(conn) {}
+    virtual future<> put(std::vector<temporary_buffer<char>> data) override {
+        std::vector<fragment> frags;
+        frags.reserve(data.size());
+        for (auto& e : data) {
+            frags.push_back(fragment{e.get_write(), e.size()});
+        }
+        return _conn.send(packet(std::move(frags), [tmp = std::move(data)] () mutable {}));
+    }
+};
+
+template <typename Protocol>
+input_stream<char>
+native_connected_socket_impl<Protocol>::input() {
+    data_source ds(std::make_unique<native_data_source_impl>(_conn));
+    return input_stream<char>(std::move(ds));
+}
+
+template <typename Protocol>
+output_stream<char>
+native_connected_socket_impl<Protocol>::output() {
+    data_sink ds(std::make_unique<native_data_sink_impl>(_conn));
+    return output_stream<char>(std::move(ds), 8192);
+}
+
+
+std::unique_ptr<native_networking_stack> native_networking_stack::_s;
+
+}
diff --git a/net/stack.hh b/net/stack.hh
new file mode 100644
index 0000000000..5976f4bd57
--- /dev/null
+++ b/net/stack.hh
@@ -0,0 +1,17 @@
+/*
+ * Copyright (C) 2014 Cloudius Systems, Ltd.
+ */
+
+#ifndef STACK_HH_
+#define STACK_HH_
+
+#include "core/reactor.hh"
+
+namespace net {
+
+std::unique_ptr<networking_stack>
+create_native_networking_stack();
+
+}
+
+#endif /* STACK_HH_ */