start implementing parsing of packets server-side

cmake/CompilerWarnings.cmake

@@ -73,7 +73,6 @@ function(set_project_warnings project_name)
             -Werror=missing-declarations
             -Werror=missing-field-initializers
             -Werror=ctor-dtor-privacy
-            -Werror=switch-enum
             -Wswitch-default
             -Werror=unused-result
             -Werror=implicit-fallthrough

include/Network.h

@@ -4,9 +4,10 @@
 #include "Sync.h"
 #include "Transport.h"
 #include <boost/asio.hpp>
+#include <boost/thread/scoped_thread.hpp>
 #include <cstdint>
-#include <memory>
 #include <filesystem>
+#include <memory>
 #include <unordered_map>
 #include <vector>
 
@@ -26,24 +27,40 @@ struct Packet {
 struct Client {
     using Ptr = std::shared_ptr<Client>;
     ClientID id;
-    bmp::State state;
+    bmp::State state { bmp::State::None };
 
+    /// Reads a single packet from the TCP stream. Blocks all other reads (not writes).
     Packet tcp_read();
+    /// Writes the packet to the TCP stream. Blocks all other writes.
     void tcp_write(const Packet& packet);
+    /// Writes the specified to the TCP stream without a header or any metadata - use in
+    /// conjunction with something else. Blocks other writes.
     void tcp_write_file_raw(const std::filesystem::path& path);
-    Packet udp_read(ip::udp::socket& socket);
-    void udp_write(const Packet& packet, ip::udp::socket& socket);
 
-    Client(ip::udp::endpoint& ep, ip::tcp::socket&& socket);
+    Client(ClientID id, class Network& network, ip::tcp::socket&& tcp_socket);
     ~Client();
 
+    ip::tcp::socket& tcp_socket() { return m_tcp_socket; }
+
+    [[nodiscard]] const ip::udp::endpoint& udp_endpoint() const { return m_udp_ep; }
+    void set_udp_endpoint(const ip::udp::endpoint& ep) { m_udp_ep = ep; }
+
+    void start_tcp();
+
 private:
+
+    void tcp_main();
+
     std::mutex m_tcp_read_mtx;
     std::mutex m_tcp_write_mtx;
     std::mutex m_udp_read_mtx;
 
     ip::udp::endpoint m_udp_ep;
     ip::tcp::socket m_tcp_socket;
+
+    boost::scoped_thread<> m_tcp_thread;
+
+    class Network& m_network;
 };
 
 struct Vehicle {
@@ -54,11 +71,38 @@ struct Vehicle {
 
 class Network {
 public:
+    Network();
+    ~Network();
 
+    /// Reads a packet from the given UDP socket, returning the client's endpoint as an out-argument.
+    Packet udp_read(ip::udp::endpoint& out_ep);
+    /// Sends a packet to the specified UDP endpoint via the UDP socket.
+    void udp_write(const Packet& packet, const ip::udp::endpoint& to_ep);
+
+    void disconnect(ClientID id, const std::string& msg);
+
+    void handle_packet(ClientID i, const Packet& packet);
 
 private:
-    Sync<std::unordered_map<ClientID, Client::Ptr>> m_clients;
+    void udp_read_main();
-    Sync<std::unordered_map<VehicleID, Vehicle::Ptr>> m_vehicles;
+    void tcp_listen_main();
-    boost::asio::io_context m_io;
-};
 
+    Sync<std::unordered_map<ClientID, Client::Ptr>> m_clients {};
+    Sync<std::unordered_map<VehicleID, Vehicle::Ptr>> m_vehicles {};
+
+    ClientID new_client_id() {
+        static Sync<ClientID> s_id { 0 };
+        auto id = s_id.synchronize();
+        ClientID new_id = *id;
+        *id += 1;
+        return new_id;
+    }
+
+    boost::scoped_thread<> m_tcp_listen_thread;
+    boost::scoped_thread<> m_udp_read_thread;
+
+    io_context m_io {};
+    thread_pool m_threadpool {};
+    Sync<bool> m_shutdown { false };
+    ip::udp::socket m_udp_socket { m_io };
+};

src/Network.cpp

@@ -1,14 +1,16 @@
 #include "Network.h"
+#include "ClientInfo.h"
 #include "Common.h"
 #include "Environment.h"
+#include "ProtocolVersion.h"
+#include "ServerInfo.h"
 
 #if defined(BEAMMP_LINUX)
-#include <cstring>
 #include <cerrno>
+#include <cstring>
 #include <sys/sendfile.h>
 #include <unistd.h>
 #elif defined(BEAMMP_WINDOWS)
-#else
 #include <boost/iostreams/device/mapped_file.hpp>
 #endif
 
@@ -39,38 +41,8 @@ void Client::tcp_write(const Packet& packet) {
     write(m_tcp_socket, buffer(packet.data));
 }
 
-Packet Client::udp_read(ip::udp::socket& socket) {
-    // maximum we can ever expect from udp
-    static thread_local std::vector<uint8_t> s_buffer(std::numeric_limits<uint16_t>::max());
-    std::unique_lock lock(m_udp_read_mtx);
-    socket.receive_from(buffer(s_buffer), m_udp_ep, {});
-    Packet packet;
-    bmp::Header header {};
-    auto offset = header.deserialize_from(s_buffer);
-    if (header.flags != bmp::Flags::None) {
-        beammp_errorf("Flags are not implemented");
-        return {};
-    }
-    return packet;
-}
-
-void Client::udp_write(const Packet& packet, ip::udp::socket& socket) {
-    auto header = packet.header();
-    std::vector<uint8_t> data(header.size + bmp::Header::SERIALIZED_SIZE);
-    auto offset = header.serialize_to(data);
-    std::copy(packet.data.begin(), packet.data.end(), data.begin() + static_cast<long>(offset));
-    socket.send_to(buffer(data), m_udp_ep, {});
-}
-
-Client::~Client() {
-    m_tcp_socket.shutdown(boost::asio::socket_base::shutdown_receive);
-}
-
-Client::Client(ip::udp::endpoint& ep, ip::tcp::socket&& socket)
-    : m_udp_ep(ep)
-    , m_tcp_socket(std::forward<ip::tcp::socket&&>(socket)) {
-}
 void Client::tcp_write_file_raw(const std::filesystem::path& path) {
+    std::unique_lock lock(m_tcp_write_mtx);
 #if defined(BEAMMP_LINUX)
     // sendfile
     auto size = std::filesystem::file_size(path);
@@ -88,10 +60,42 @@ void Client::tcp_write_file_raw(const std::filesystem::path& path) {
     // TODO: Use TransmitFile on Windows for better performance
     // primitive implementation using a memory-mapped file
     boost::iostreams::mapped_file f(path.generic_string(), boost::iostreams::mapped_file::mapmode::readonly);
-    std::unique_lock lock(m_tcp_write_mtx);
     write(m_tcp_socket, buffer(f.data(), f.size()));
 #endif
 }
+
+Client::~Client() {
+    beammp_debugf("Client {} shutting down", id);
+    m_tcp_socket.shutdown(boost::asio::socket_base::shutdown_receive);
+    m_tcp_thread.interrupt();
+    beammp_debugf("Client {} shut down", id);
+}
+
+Client::Client(ClientID id, Network& network, ip::tcp::socket&& tcp_socket)
+    : id(id)
+    , m_tcp_socket(std::forward<ip::tcp::socket&&>(tcp_socket))
+    , m_network(network) {
+    beammp_debugf("Client {} created", id);
+}
+
+void Client::start_tcp() {
+    m_tcp_thread = boost::scoped_thread<>(&Client::tcp_main, this);
+}
+
+void Client::tcp_main() {
+    beammp_debugf("TCP thread started for client {}", id);
+    try {
+        while (true) {
+            auto packet = tcp_read();
+            m_network.handle_packet(id, packet);
+        }
+    } catch (const std::exception& e) {
+        beammp_errorf("Error in tcp loop of client {}: {}", id, e.what());
+        m_network.disconnect(id, "error in tcp loop");
+    }
+    beammp_debugf("TCP thread stopped for client {}", id);
+}
+
 bmp::Header Packet::header() const {
     return {
         .purpose = purpose,
@@ -100,3 +104,164 @@ bmp::Header Packet::header() const {
         .size = static_cast<uint32_t>(data.size()),
     };
 }
+
+Packet Network::udp_read(ip::udp::endpoint& out_ep) {
+    // maximum we can ever expect from udp
+    static thread_local std::vector<uint8_t> s_buffer(std::numeric_limits<uint16_t>::max());
+    m_udp_socket.receive_from(buffer(s_buffer), out_ep, {});
+    Packet packet;
+    bmp::Header header {};
+    auto offset = header.deserialize_from(s_buffer);
+    if (header.flags != bmp::Flags::None) {
+        beammp_errorf("Flags are not implemented");
+        return {};
+    }
+    return packet;
+}
+
+void Network::udp_write(const Packet& packet, const ip::udp::endpoint& to_ep) {
+    auto header = packet.header();
+    std::vector<uint8_t> data(header.size + bmp::Header::SERIALIZED_SIZE);
+    auto offset = header.serialize_to(data);
+    std::copy(packet.data.begin(), packet.data.end(), data.begin() + static_cast<long>(offset));
+    m_udp_socket.send_to(buffer(data), to_ep, {});
+}
+
+Network::Network()
+    : m_tcp_listen_thread(&Network::tcp_listen_main, this)
+    , m_udp_read_thread(&Network::udp_read_main, this)
+    , m_threadpool(std::thread::hardware_concurrency()) {
+    Application::RegisterShutdownHandler([this] {
+        *m_shutdown = true;
+        m_tcp_listen_thread.interrupt();
+        m_udp_read_thread.interrupt();
+    });
+}
+
+Network::~Network() {
+    *m_shutdown = true;
+}
+
+void Network::tcp_listen_main() {
+    ip::tcp::endpoint listen_ep(ip::address::from_string("0.0.0.0"), static_cast<uint16_t>(Application::Settings.Port));
+    ip::tcp::socket listener(m_threadpool);
+    boost::system::error_code ec;
+    listener.open(listen_ep.protocol(), ec);
+    if (ec) {
+        beammp_errorf("Failed to open socket: {}", ec.message());
+        return;
+    }
+    socket_base::linger linger_opt {};
+    linger_opt.enabled(false);
+    listener.set_option(linger_opt, ec);
+    if (ec) {
+        beammp_errorf("Failed to set up listening socket to not linger / reuse address. "
+                      "This may cause the socket to refuse to bind(). Error: {}",
+            ec.message());
+    }
+
+    ip::tcp::acceptor acceptor(m_threadpool, listen_ep);
+    acceptor.listen(socket_base::max_listen_connections, ec);
+    if (ec) {
+        beammp_errorf("listen() failed, which is needed for the server to operate. "
+                      "Shutting down. Error: {}",
+            ec.message());
+        Application::GracefullyShutdown();
+    }
+    while (!*m_shutdown) {
+        auto new_socket = acceptor.accept();
+        if (ec) {
+            beammp_errorf("Failed to accept client: {}", ec.message());
+            continue;
+        }
+        // TODO: Remove log
+        beammp_debugf("New connection from {}", new_socket.remote_endpoint().address().to_string(), new_socket.remote_endpoint().port());
+        auto new_id = new_client_id();
+        std::shared_ptr<Client> new_client(std::make_shared<Client>(new_id, *this, std::move(new_socket)));
+        m_clients->emplace(new_id, new_client);
+    }
+}
+
+void Network::udp_read_main() {
+    while (!*m_shutdown) {
+    }
+}
+
+void Network::disconnect(ClientID id, const std::string& msg) {
+    beammp_infof("Disconnecting client {}: {}", id, msg);
+    m_clients->erase(id);
+}
+void Network::handle_packet(ClientID id, const Packet& packet) {
+    std::shared_ptr<Client> client;
+    {
+        auto clients = m_clients.synchronize();
+        if (!clients->contains(id)) {
+            beammp_warnf("Tried to handle packet for client {} who is already disconnected", id);
+            return;
+        }
+        client = clients->at(id);
+    }
+    switch (client->state) {
+    case bmp::State::None:
+        // move to identification
+        client->state = bmp::State::Identification;
+        // and fall through
+        [[fallthrough]];
+    case bmp::State::Identification:
+        switch (packet.purpose) {
+        case bmp::Purpose::ProtocolVersion: {
+            struct bmp::ProtocolVersion protocol_version { };
+            protocol_version.deserialize_from(packet.data);
+            if (protocol_version.version.major != 1) {
+                beammp_debugf("{}: Protocol version bad", id);
+                // version bad
+                Packet protocol_v_bad_packet {
+                    .purpose = bmp::ProtocolVersionBad,
+                };
+                client->tcp_write(protocol_v_bad_packet);
+                disconnect(id, fmt::format("bad protocol version: {}.{}.{}", protocol_version.version.major, protocol_version.version.minor, protocol_version.version.patch));
+            } else {
+                beammp_debugf("{}: Protocol version ok", id);
+                // version ok
+                Packet protocol_v_ok_packet {
+                    .purpose = bmp::ProtocolVersionOk,
+                };
+                client->tcp_write(protocol_v_ok_packet);
+            }
+            break;
+        }
+        case bmp::Purpose::ClientInfo: {
+            struct bmp::ClientInfo cinfo { };
+            cinfo.deserialize_from(packet.data);
+            beammp_debugf("{} is running game version: v{}.{}.{}, mod version: v{}.{}.{}, client implementation '{}' v{}.{}.{}",
+                id,
+                cinfo.game_version.major,
+                cinfo.game_version.minor,
+                cinfo.game_version.patch,
+                cinfo.mod_version.major,
+                cinfo.mod_version.minor,
+                cinfo.mod_version.patch,
+                cinfo.implementation.value,
+                cinfo.program_version.major,
+                cinfo.program_version.minor,
+                cinfo.program_version.patch);
+            break;
+        }
+        default:
+            beammp_errorf("Got 0x{:x} in state {}. This is not allowed disconnecting the client", uint16_t(packet.purpose), int(client->state));
+            disconnect(id, "invalid purpose in current state");
+            return;
+        }
+        break;
+    case bmp::State::Authentication:
+        break;
+    case bmp::State::ModDownload:
+        break;
+    case bmp::State::SessionSetup:
+        break;
+    case bmp::State::Playing:
+        break;
+    case bmp::State::Leaving:
+        break;
+    }
+}