1 files changed, 398 insertions, 4 deletions

diff --git a/src/network/room.cpp b/src/network/room.cpp
index 48de2f5cb..8b7915bb7 100644
--- a/src/network/room.cpp
+++ b/src/network/room.cpp
@@ -2,7 +2,13 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include <algorithm>
+#include <atomic>
+#include <random>
+#include <thread>
+#include <vector>
 #include "enet/enet.h"
+#include "network/packet.h"
 #include "network/room.h"
 
 namespace Network {
@@ -12,12 +18,395 @@ static constexpr u32 MaxConcurrentConnections = 10;
 
 class Room::RoomImpl {
 public:
+    // This MAC address is used to generate a 'Nintendo' like Mac address.
+    const MacAddress NintendoOUI = {0x00, 0x1F, 0x32, 0x00, 0x00, 0x00};
+    std::mt19937 random_gen; ///< Random number generator. Used for GenerateMacAddress
+
     ENetHost* server = nullptr; ///< Network interface.
 
     std::atomic<State> state{State::Closed}; ///< Current state of the room.
     RoomInformation room_information;        ///< Information about this room.
+
+    struct Member {
+        std::string nickname;   ///< The nickname of the member.
+        std::string game_name;  ///< The current game of the member
+        MacAddress mac_address; ///< The assigned mac address of the member.
+        ENetPeer* peer;         ///< The remote peer.
+    };
+    using MemberList = std::vector<Member>;
+    MemberList members; ///< Information about the members of this room.
+
+    RoomImpl() : random_gen(std::random_device()()) {}
+
+    /// Thread that receives and dispatches network packets
+    std::unique_ptr<std::thread> room_thread;
+
+    /// Thread function that will receive and dispatch messages until the room is destroyed.
+    void ServerLoop();
+    void StartLoop();
+
+    /**
+     * Parses and answers a room join request from a client.
+     * Validates the uniqueness of the username and assigns the MAC address
+     * that the client will use for the remainder of the connection.
+     */
+    void HandleJoinRequest(const ENetEvent* event);
+
+    /**
+     * Returns whether the nickname is valid, ie. isn't already taken by someone else in the room.
+     */
+    bool IsValidNickname(const std::string& nickname) const;
+
+    /**
+     * Returns whether the MAC address is valid, ie. isn't already taken by someone else in the
+     * room.
+     */
+    bool IsValidMacAddress(const MacAddress& address) const;
+
+    /**
+     * Sends a ID_ROOM_NAME_COLLISION message telling the client that the name is invalid.
+     */
+    void SendNameCollision(ENetPeer* client);
+
+    /**
+     * Sends a ID_ROOM_MAC_COLLISION message telling the client that the MAC is invalid.
+     */
+    void SendMacCollision(ENetPeer* client);
+
+    /**
+     * Sends a ID_ROOM_VERSION_MISMATCH message telling the client that the version is invalid.
+     */
+    void SendVersionMismatch(ENetPeer* client);
+
+    /**
+     * Notifies the member that its connection attempt was successful,
+     * and it is now part of the room.
+     */
+    void SendJoinSuccess(ENetPeer* client, MacAddress mac_address);
+
+    /**
+     * Notifies the members that the room is closed,
+     */
+    void SendCloseMessage();
+
+    /**
+     * Sends the information about the room, along with the list of members
+     * to every connected client in the room.
+     * The packet has the structure:
+     * <MessageID>ID_ROOM_INFORMATION
+     * <String> room_name
+     * <u32> member_slots: The max number of clients allowed in this room
+     * <u32> num_members: the number of currently joined clients
+     * This is followed by the following three values for each member:
+     * <String> nickname of that member
+     * <MacAddress> mac_address of that member
+     * <String> game_name of that member
+     */
+    void BroadcastRoomInformation();
+
+    /**
+     * Generates a free MAC address to assign to a new client.
+     * The first 3 bytes are the NintendoOUI 0x00, 0x1F, 0x32
+     */
+    MacAddress GenerateMacAddress();
+
+    /**
+     * Broadcasts this packet to all members except the sender.
+     * @param event The ENet event containing the data
+     */
+    void HandleWifiPacket(const ENetEvent* event);
+
+    /**
+     * Extracts a chat entry from a received ENet packet and adds it to the chat queue.
+     * @param event The ENet event that was received.
+     */
+    void HandleChatPacket(const ENetEvent* event);
+
+    /**
+     * Extracts the game name from a received ENet packet and broadcasts it.
+     * @param event The ENet event that was received.
+     */
+    void HandleGameNamePacket(const ENetEvent* event);
+
+    /**
+     * Removes the client from the members list if it was in it and announces the change
+     * to all other clients.
+     */
+    void HandleClientDisconnection(ENetPeer* client);
 };
 
+// RoomImpl
+void Room::RoomImpl::ServerLoop() {
+    while (state != State::Closed) {
+        ENetEvent event;
+        if (enet_host_service(server, &event, 100) > 0) {
+            switch (event.type) {
+            case ENET_EVENT_TYPE_RECEIVE:
+                switch (event.packet->data[0]) {
+                case IdJoinRequest:
+                    HandleJoinRequest(&event);
+                    break;
+                case IdSetGameName:
+                    HandleGameNamePacket(&event);
+                    break;
+                case IdWifiPacket:
+                    HandleWifiPacket(&event);
+                    break;
+                case IdChatMessage:
+                    HandleChatPacket(&event);
+                    break;
+                }
+                enet_packet_destroy(event.packet);
+                break;
+            case ENET_EVENT_TYPE_DISCONNECT:
+                HandleClientDisconnection(event.peer);
+                break;
+            }
+        }
+    }
+    // Close the connection to all members:
+    SendCloseMessage();
+}
+
+void Room::RoomImpl::StartLoop() {
+    room_thread = std::make_unique<std::thread>(&Room::RoomImpl::ServerLoop, this);
+}
+
+void Room::RoomImpl::HandleJoinRequest(const ENetEvent* event) {
+    Packet packet;
+    packet.Append(event->packet->data, event->packet->dataLength);
+    packet.IgnoreBytes(sizeof(u8)); // Igonore the message type
+    std::string nickname;
+    packet >> nickname;
+
+    MacAddress preferred_mac;
+    packet >> preferred_mac;
+
+    u32 client_version;
+    packet >> client_version;
+
+    if (!IsValidNickname(nickname)) {
+        SendNameCollision(event->peer);
+        return;
+    }
+
+    if (preferred_mac != NoPreferredMac) {
+        // Verify if the preferred mac is available
+        if (!IsValidMacAddress(preferred_mac)) {
+            SendMacCollision(event->peer);
+            return;
+        }
+    } else {
+        // Assign a MAC address of this client automatically
+        preferred_mac = GenerateMacAddress();
+    }
+
+    if (client_version != network_version) {
+        SendVersionMismatch(event->peer);
+        return;
+    }
+
+    // At this point the client is ready to be added to the room.
+    Member member{};
+    member.mac_address = preferred_mac;
+    member.nickname = nickname;
+    member.peer = event->peer;
+
+    members.push_back(std::move(member));
+
+    // Notify everyone that the room information has changed.
+    BroadcastRoomInformation();
+    SendJoinSuccess(event->peer, preferred_mac);
+}
+
+bool Room::RoomImpl::IsValidNickname(const std::string& nickname) const {
+    // A nickname is valid if it is not already taken by anybody else in the room.
+    // TODO(B3N30): Check for empty names, spaces, etc.
+    return std::all_of(members.begin(), members.end(),
+                       [&nickname](const auto& member) { return member.nickname != nickname; });
+}
+
+bool Room::RoomImpl::IsValidMacAddress(const MacAddress& address) const {
+    // A MAC address is valid if it is not already taken by anybody else in the room.
+    return std::all_of(members.begin(), members.end(),
+                       [&address](const auto& member) { return member.mac_address != address; });
+}
+
+void Room::RoomImpl::SendNameCollision(ENetPeer* client) {
+    Packet packet;
+    packet << static_cast<u8>(IdNameCollision);
+
+    ENetPacket* enet_packet =
+        enet_packet_create(packet.GetData(), packet.GetDataSize(), ENET_PACKET_FLAG_RELIABLE);
+    enet_peer_send(client, 0, enet_packet);
+    enet_host_flush(server);
+}
+
+void Room::RoomImpl::SendMacCollision(ENetPeer* client) {
+    Packet packet;
+    packet << static_cast<u8>(IdMacCollision);
+
+    ENetPacket* enet_packet =
+        enet_packet_create(packet.GetData(), packet.GetDataSize(), ENET_PACKET_FLAG_RELIABLE);
+    enet_peer_send(client, 0, enet_packet);
+    enet_host_flush(server);
+}
+
+void Room::RoomImpl::SendVersionMismatch(ENetPeer* client) {
+    Packet packet;
+    packet << static_cast<u8>(IdVersionMismatch);
+    packet << network_version;
+
+    ENetPacket* enet_packet =
+        enet_packet_create(packet.GetData(), packet.GetDataSize(), ENET_PACKET_FLAG_RELIABLE);
+    enet_peer_send(client, 0, enet_packet);
+    enet_host_flush(server);
+}
+
+void Room::RoomImpl::SendJoinSuccess(ENetPeer* client, MacAddress mac_address) {
+    Packet packet;
+    packet << static_cast<u8>(IdJoinSuccess);
+    packet << mac_address;
+    ENetPacket* enet_packet =
+        enet_packet_create(packet.GetData(), packet.GetDataSize(), ENET_PACKET_FLAG_RELIABLE);
+    enet_peer_send(client, 0, enet_packet);
+    enet_host_flush(server);
+}
+
+void Room::RoomImpl::SendCloseMessage() {
+    Packet packet;
+    packet << static_cast<u8>(IdCloseRoom);
+    ENetPacket* enet_packet =
+        enet_packet_create(packet.GetData(), packet.GetDataSize(), ENET_PACKET_FLAG_RELIABLE);
+    for (auto& member : members) {
+        enet_peer_send(member.peer, 0, enet_packet);
+    }
+    enet_host_flush(server);
+    for (auto& member : members) {
+        enet_peer_disconnect(member.peer, 0);
+    }
+}
+
+void Room::RoomImpl::BroadcastRoomInformation() {
+    Packet packet;
+    packet << static_cast<u8>(IdRoomInformation);
+    packet << room_information.name;
+    packet << room_information.member_slots;
+
+    packet << static_cast<u32>(members.size());
+    for (const auto& member : members) {
+        packet << member.nickname;
+        packet << member.mac_address;
+        packet << member.game_name;
+    }
+
+    ENetPacket* enet_packet =
+        enet_packet_create(packet.GetData(), packet.GetDataSize(), ENET_PACKET_FLAG_RELIABLE);
+    enet_host_broadcast(server, 0, enet_packet);
+    enet_host_flush(server);
+}
+
+MacAddress Room::RoomImpl::GenerateMacAddress() {
+    MacAddress result_mac =
+        NintendoOUI; // The first three bytes of each MAC address will be the NintendoOUI
+    std::uniform_int_distribution<> dis(0x00, 0xFF); // Random byte between 0 and 0xFF
+    do {
+        for (size_t i = 3; i < result_mac.size(); ++i) {
+            result_mac[i] = dis(random_gen);
+        }
+    } while (!IsValidMacAddress(result_mac));
+    return result_mac;
+}
+
+void Room::RoomImpl::HandleWifiPacket(const ENetEvent* event) {
+    Packet in_packet;
+    in_packet.Append(event->packet->data, event->packet->dataLength);
+    in_packet.IgnoreBytes(sizeof(u8));         // Message type
+    in_packet.IgnoreBytes(sizeof(u8));         // WifiPacket Type
+    in_packet.IgnoreBytes(sizeof(u8));         // WifiPacket Channel
+    in_packet.IgnoreBytes(sizeof(MacAddress)); // WifiPacket Transmitter Address
+    MacAddress destination_address;
+    in_packet >> destination_address;
+
+    Packet out_packet;
+    out_packet.Append(event->packet->data, event->packet->dataLength);
+    ENetPacket* enet_packet = enet_packet_create(out_packet.GetData(), out_packet.GetDataSize(),
+                                                 ENET_PACKET_FLAG_RELIABLE);
+
+    if (destination_address == BroadcastMac) { // Send the data to everyone except the sender
+        for (const auto& member : members) {
+            if (member.peer != event->peer)
+                enet_peer_send(member.peer, 0, enet_packet);
+        }
+    } else { // Send the data only to the destination client
+        auto member = std::find_if(members.begin(), members.end(),
+                                   [destination_address](const Member& member) -> bool {
+                                       return member.mac_address == destination_address;
+                                   });
+        if (member != members.end()) {
+            enet_peer_send(member->peer, 0, enet_packet);
+        }
+    }
+    enet_host_flush(server);
+}
+
+void Room::RoomImpl::HandleChatPacket(const ENetEvent* event) {
+    Packet in_packet;
+    in_packet.Append(event->packet->data, event->packet->dataLength);
+
+    in_packet.IgnoreBytes(sizeof(u8)); // Igonore the message type
+    std::string message;
+    in_packet >> message;
+    auto CompareNetworkAddress = [event](const Member member) -> bool {
+        return member.peer == event->peer;
+    };
+    const auto sending_member = std::find_if(members.begin(), members.end(), CompareNetworkAddress);
+    if (sending_member == members.end()) {
+        return; // Received a chat message from a unknown sender
+    }
+
+    Packet out_packet;
+    out_packet << static_cast<u8>(IdChatMessage);
+    out_packet << sending_member->nickname;
+    out_packet << message;
+
+    ENetPacket* enet_packet = enet_packet_create(out_packet.GetData(), out_packet.GetDataSize(),
+                                                 ENET_PACKET_FLAG_RELIABLE);
+    for (const auto& member : members) {
+        if (member.peer != event->peer)
+            enet_peer_send(member.peer, 0, enet_packet);
+    }
+    enet_host_flush(server);
+}
+
+void Room::RoomImpl::HandleGameNamePacket(const ENetEvent* event) {
+    Packet in_packet;
+    in_packet.Append(event->packet->data, event->packet->dataLength);
+
+    in_packet.IgnoreBytes(sizeof(u8)); // Igonore the message type
+    std::string game_name;
+    in_packet >> game_name;
+    auto member =
+        std::find_if(members.begin(), members.end(),
+                     [event](const Member& member) -> bool { return member.peer == event->peer; });
+    if (member != members.end()) {
+        member->game_name = game_name;
+        BroadcastRoomInformation();
+    }
+}
+
+void Room::RoomImpl::HandleClientDisconnection(ENetPeer* client) {
+    // Remove the client from the members list.
+    members.erase(std::remove_if(members.begin(), members.end(),
+                                 [client](const Member& member) { return member.peer == client; }),
+                  members.end());
+
+    // Announce the change to all clients.
+    enet_peer_disconnect(client, 0);
+    BroadcastRoomInformation();
+}
+
+// Room
 Room::Room() : room_impl{std::make_unique<RoomImpl>()} {}
 
 Room::~Room() = default;
@@ -25,7 +414,9 @@ Room::~Room() = default;
 void Room::Create(const std::string& name, const std::string& server_address, u16 server_port) {
     ENetAddress address;
     address.host = ENET_HOST_ANY;
-    enet_address_set_host(&address, server_address.c_str());
+    if (!server_address.empty()) {
+        enet_address_set_host(&address, server_address.c_str());
+    }
     address.port = server_port;
 
     room_impl->server = enet_host_create(&address, MaxConcurrentConnections, NumChannels, 0, 0);
@@ -34,8 +425,7 @@ void Room::Create(const std::string& name, const std::string& server_address, u1
 
     room_impl->room_information.name = name;
     room_impl->room_information.member_slots = MaxConcurrentConnections;
-
-    // TODO(B3N30): Start the receiving thread
+    room_impl->StartLoop();
 }
 
 Room::State Room::GetState() const {
@@ -48,13 +438,17 @@ const RoomInformation& Room::GetRoomInformation() const {
 
 void Room::Destroy() {
     room_impl->state = State::Closed;
-    // TODO(B3n30): Join the receiving thread
+    room_impl->room_thread->join();
+    room_impl->room_thread.reset();
 
     if (room_impl->server) {
         enet_host_destroy(room_impl->server);
     }
     room_impl->room_information = {};
     room_impl->server = nullptr;
+    room_impl->members.clear();
+    room_impl->room_information.member_slots = 0;
+    room_impl->room_information.name.clear();
 }
 
 } // namespace Network