ldn: Initial implementation

src/network/room.cpp

@@ -211,6 +211,12 @@ public:
      */
     void HandleProxyPacket(const ENetEvent* event);
 
+    /**
+     * Broadcasts this packet to all members except the sender.
+     * @param event The ENet event containing the data
+     */
+    void HandleLdnPacket(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.
@@ -247,6 +253,9 @@ void Room::RoomImpl::ServerLoop() {
                 case IdProxyPacket:
                     HandleProxyPacket(&event);
                     break;
+                case IdLdnPacket:
+                    HandleLdnPacket(&event);
+                    break;
                 case IdChatMessage:
                     HandleChatPacket(&event);
                     break;
@@ -861,6 +870,60 @@ void Room::RoomImpl::HandleProxyPacket(const ENetEvent* event) {
     enet_host_flush(server);
 }
 
+void Room::RoomImpl::HandleLdnPacket(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));          // LAN packet type
+    in_packet.IgnoreBytes(sizeof(IPv4Address)); // Local IP
+
+    IPv4Address remote_ip;
+    in_packet.Read(remote_ip); // Remote IP
+
+    bool broadcast;
+    in_packet.Read(broadcast); // Broadcast
+
+    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);
+
+    const auto& destination_address = remote_ip;
+    if (broadcast) { // Send the data to everyone except the sender
+        std::lock_guard lock(member_mutex);
+        bool sent_packet = false;
+        for (const auto& member : members) {
+            if (member.peer != event->peer) {
+                sent_packet = true;
+                enet_peer_send(member.peer, 0, enet_packet);
+            }
+        }
+
+        if (!sent_packet) {
+            enet_packet_destroy(enet_packet);
+        }
+    } else {
+        std::lock_guard lock(member_mutex);
+        auto member = std::find_if(members.begin(), members.end(),
+                                   [destination_address](const Member& member_entry) -> bool {
+                                       return member_entry.fake_ip == destination_address;
+                                   });
+        if (member != members.end()) {
+            enet_peer_send(member->peer, 0, enet_packet);
+        } else {
+            LOG_ERROR(Network,
+                      "Attempting to send to unknown IP address: "
+                      "{}.{}.{}.{}",
+                      destination_address[0], destination_address[1], destination_address[2],
+                      destination_address[3]);
+            enet_packet_destroy(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);

src/network/room.h

@@ -40,6 +40,7 @@ enum RoomMessageTypes : u8 {
     IdRoomInformation,
     IdSetGameInfo,
     IdProxyPacket,
+    IdLdnPacket,
     IdChatMessage,
     IdNameCollision,
     IdIpCollision,

src/network/room_member.cpp

@@ -58,6 +58,7 @@ public:
 
     private:
         CallbackSet<ProxyPacket> callback_set_proxy_packet;
+        CallbackSet<LDNPacket> callback_set_ldn_packet;
         CallbackSet<ChatEntry> callback_set_chat_messages;
         CallbackSet<StatusMessageEntry> callback_set_status_messages;
         CallbackSet<RoomInformation> callback_set_room_information;
@@ -107,6 +108,12 @@ public:
      */
     void HandleProxyPackets(const ENetEvent* event);
 
+    /**
+     * Extracts an LdnPacket from a received ENet packet.
+     * @param event The ENet event that was received.
+     */
+    void HandleLdnPackets(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.
@@ -166,6 +173,9 @@ void RoomMember::RoomMemberImpl::MemberLoop() {
                 case IdProxyPacket:
                     HandleProxyPackets(&event);
                     break;
+                case IdLdnPacket:
+                    HandleLdnPackets(&event);
+                    break;
                 case IdChatMessage:
                     HandleChatPacket(&event);
                     break;
@@ -372,6 +382,27 @@ void RoomMember::RoomMemberImpl::HandleProxyPackets(const ENetEvent* event) {
     Invoke<ProxyPacket>(proxy_packet);
 }
 
+void RoomMember::RoomMemberImpl::HandleLdnPackets(const ENetEvent* event) {
+    LDNPacket ldn_packet{};
+    Packet packet;
+    packet.Append(event->packet->data, event->packet->dataLength);
+
+    // Ignore the first byte, which is the message id.
+    packet.IgnoreBytes(sizeof(u8)); // Ignore the message type
+
+    u8 packet_type;
+    packet.Read(packet_type);
+    ldn_packet.type = static_cast<LDNPacketType>(packet_type);
+
+    packet.Read(ldn_packet.local_ip);
+    packet.Read(ldn_packet.remote_ip);
+    packet.Read(ldn_packet.broadcast);
+
+    packet.Read(ldn_packet.data);
+
+    Invoke<LDNPacket>(ldn_packet);
+}
+
 void RoomMember::RoomMemberImpl::HandleChatPacket(const ENetEvent* event) {
     Packet packet;
     packet.Append(event->packet->data, event->packet->dataLength);
@@ -449,6 +480,11 @@ RoomMember::RoomMemberImpl::CallbackSet<ProxyPacket>& RoomMember::RoomMemberImpl
     return callback_set_proxy_packet;
 }
 
+template <>
+RoomMember::RoomMemberImpl::CallbackSet<LDNPacket>& RoomMember::RoomMemberImpl::Callbacks::Get() {
+    return callback_set_ldn_packet;
+}
+
 template <>
 RoomMember::RoomMemberImpl::CallbackSet<RoomMember::State>&
 RoomMember::RoomMemberImpl::Callbacks::Get() {
@@ -607,6 +643,21 @@ void RoomMember::SendProxyPacket(const ProxyPacket& proxy_packet) {
     room_member_impl->Send(std::move(packet));
 }
 
+void RoomMember::SendLdnPacket(const LDNPacket& ldn_packet) {
+    Packet packet;
+    packet.Write(static_cast<u8>(IdLdnPacket));
+
+    packet.Write(static_cast<u8>(ldn_packet.type));
+
+    packet.Write(ldn_packet.local_ip);
+    packet.Write(ldn_packet.remote_ip);
+    packet.Write(ldn_packet.broadcast);
+
+    packet.Write(ldn_packet.data);
+
+    room_member_impl->Send(std::move(packet));
+}
+
 void RoomMember::SendChatMessage(const std::string& message) {
     Packet packet;
     packet.Write(static_cast<u8>(IdChatMessage));
@@ -663,6 +714,11 @@ RoomMember::CallbackHandle<ProxyPacket> RoomMember::BindOnProxyPacketReceived(
     return room_member_impl->Bind(callback);
 }
 
+RoomMember::CallbackHandle<LDNPacket> RoomMember::BindOnLdnPacketReceived(
+    std::function<void(const LDNPacket&)> callback) {
+    return room_member_impl->Bind(callback);
+}
+
 RoomMember::CallbackHandle<RoomInformation> RoomMember::BindOnRoomInformationChanged(
     std::function<void(const RoomInformation&)> callback) {
     return room_member_impl->Bind(callback);
@@ -699,6 +755,7 @@ void RoomMember::Leave() {
 }
 
 template void RoomMember::Unbind(CallbackHandle<ProxyPacket>);
+template void RoomMember::Unbind(CallbackHandle<LDNPacket>);
 template void RoomMember::Unbind(CallbackHandle<RoomMember::State>);
 template void RoomMember::Unbind(CallbackHandle<RoomMember::Error>);
 template void RoomMember::Unbind(CallbackHandle<RoomInformation>);

src/network/room_member.h

@@ -17,7 +17,24 @@ namespace Network {
 using AnnounceMultiplayerRoom::GameInfo;
 using AnnounceMultiplayerRoom::RoomInformation;
 
-/// Information about the received WiFi packets.
+enum class LDNPacketType : u8 {
+    Scan,
+    ScanResp,
+    Connect,
+    SyncNetwork,
+    Disconnect,
+    DestroyNetwork,
+};
+
+struct LDNPacket {
+    LDNPacketType type;
+    IPv4Address local_ip;
+    IPv4Address remote_ip;
+    bool broadcast;
+    std::vector<u8> data;
+};
+
+/// Information about the received proxy packets.
 struct ProxyPacket {
     SockAddrIn local_endpoint;
     SockAddrIn remote_endpoint;
@@ -151,6 +168,12 @@ public:
      */
     void SendProxyPacket(const ProxyPacket& packet);
 
+    /**
+     * Sends an LDN packet to the room.
+     * @param packet The WiFi packet to send.
+     */
+    void SendLdnPacket(const LDNPacket& packet);
+
     /**
      * Sends a chat message to the room.
      * @param message The contents of the message.
@@ -204,6 +227,16 @@ public:
     CallbackHandle<ProxyPacket> BindOnProxyPacketReceived(
         std::function<void(const ProxyPacket&)> callback);
 
+    /**
+     * Binds a function to an event that will be triggered every time an LDNPacket is received.
+     * The function wil be called everytime the event is triggered.
+     * The callback function must not bind or unbind a function. Doing so will cause a deadlock
+     * @param callback The function to call
+     * @return A handle used for removing the function from the registered list
+     */
+    CallbackHandle<LDNPacket> BindOnLdnPacketReceived(
+        std::function<void(const LDNPacket&)> callback);
+
     /**
      * Binds a function to an event that will be triggered every time the RoomInformation changes.
      * The function wil be called every time the event is triggered.