src/server/net.cpp

   1 #include "ClientConnection.hpp"
   2 #include "ChunkTransmitter.hpp"
   3 #include "Server.hpp"
   4
   5 #include "../app/init.hpp"
   6 #include "../io/WorldSave.hpp"
   7 #include "../model/CompositeModel.hpp"
   8 #include "../world/ChunkIndex.hpp"
   9 #include "../world/Entity.hpp"
  10 #include "../world/World.hpp"
  11
  12 #include <iostream>
  13 #include <zlib.h>
  14 #include <glm/gtx/io.hpp>
  15
  16 using namespace std;
  17
  18
  19 namespace blank {
  20 namespace server {
  21
  22 ChunkTransmitter::ChunkTransmitter(ClientConnection &conn)
  23 : conn(conn)
  24 , current(nullptr)
  25 , buffer_size(Chunk::BlockSize() + 10)
  26 , buffer(new uint8_t[buffer_size])
  27 , buffer_len(0)
  28 , packet_len(Packet::ChunkData::MAX_DATA_LEN)
  29 , cursor(0)
  30 , num_packets(0)
  31 , begin_packet(-1)
  32 , data_packets()
  33 , confirm_wait(0)
  34 , trans_id(0)
  35 , compressed(false) {
  36
  37 }
  38
  39 ChunkTransmitter::~ChunkTransmitter() {
  40         Abort();
  41 }
  42
  43 bool ChunkTransmitter::Idle() const noexcept {
  44         return !Transmitting() && !Waiting();
  45 }
  46
  47 bool ChunkTransmitter::Transmitting() const noexcept {
  48         return cursor < num_packets;
  49 }
  50
  51 void ChunkTransmitter::Transmit() {
  52         if (cursor < num_packets) {
  53                 SendData(cursor);
  54                 ++cursor;
  55         }
  56 }
  57
  58 bool ChunkTransmitter::Waiting() const noexcept {
  59         return confirm_wait > 0;
  60 }
  61
  62 void ChunkTransmitter::Ack(uint16_t seq) {
  63         if (!Waiting()) {
  64                 return;
  65         }
  66         if (seq == begin_packet) {
  67                 begin_packet = -1;
  68                 --confirm_wait;
  69                 if (Idle()) {
  70                         Release();
  71                 }
  72                 return;
  73         }
  74         for (int i = 0, end = data_packets.size(); i < end; ++i) {
  75                 if (seq == data_packets[i]) {
  76                         data_packets[i] = -1;
  77                         --confirm_wait;
  78                         if (Idle()) {
  79                                 Release();
  80                         }
  81                         return;
  82                 }
  83         }
  84 }
  85
  86 void ChunkTransmitter::Nack(uint16_t seq) {
  87         if (!Waiting()) {
  88                 return;
  89         }
  90         if (seq == begin_packet) {
  91                 SendBegin();
  92                 return;
  93         }
  94         for (size_t i = 0, end = data_packets.size(); i < end; ++i) {
  95                 if (seq == data_packets[i]) {
  96                         SendData(i);
  97                         return;
  98                 }
  99         }
 100 }
 101
 102 void ChunkTransmitter::Abort() {
 103         if (!current) return;
 104
 105         Release();
 106
 107         begin_packet = -1;
 108         data_packets.clear();
 109         confirm_wait = 0;
 110 }
 111
 112 void ChunkTransmitter::Send(Chunk &chunk) {
 113         // abort current chunk, if any
 114         Abort();
 115
 116         current = &chunk;
 117         current->Ref();
 118
 119         // load new chunk data
 120         compressed = true;
 121         buffer_len = buffer_size;
 122         if (compress(buffer.get(), &buffer_len, reinterpret_cast<const Bytef *>(chunk.BlockData()), Chunk::BlockSize()) != Z_OK) {
 123                 // compression failed, send it uncompressed
 124                 buffer_len = Chunk::BlockSize();
 125                 memcpy(buffer.get(), chunk.BlockData(), buffer_len);
 126                 compressed = false;
 127         }
 128         cursor = 0;
 129         num_packets = (buffer_len / packet_len) + (buffer_len % packet_len != 0);
 130         data_packets.resize(num_packets, -1);
 131
 132         ++trans_id;
 133         SendBegin();
 134 }
 135
 136 void ChunkTransmitter::SendBegin() {
 137         uint32_t flags = compressed;
 138         auto pack = conn.Prepare<Packet::ChunkBegin>();
 139         pack.WriteTransmissionId(trans_id);
 140         pack.WriteFlags(flags);
 141         pack.WriteChunkCoords(current->Position());
 142         pack.WriteDataSize(buffer_len);
 143         if (begin_packet == -1) {
 144                 ++confirm_wait;
 145         }
 146         begin_packet = conn.Send();
 147 }
 148
 149 void ChunkTransmitter::SendData(size_t i) {
 150         int pos = i * packet_len;
 151         int len = min(packet_len, buffer_len - pos);
 152         const uint8_t *data = &buffer[pos];
 153
 154         auto pack = conn.Prepare<Packet::ChunkData>();
 155         pack.WriteTransmissionId(trans_id);
 156         pack.WriteDataOffset(pos);
 157         pack.WriteDataSize(len);
 158         pack.WriteData(data, len);
 159
 160         if (data_packets[i] == -1) {
 161                 ++confirm_wait;
 162         }
 163         data_packets[i] = conn.Send();
 164 }
 165
 166 void ChunkTransmitter::Release() {
 167         if (current) {
 168                 current->UnRef();
 169                 current = nullptr;
 170         }
 171 }
 172
 173
 174 ClientConnection::ClientConnection(Server &server, const IPaddress &addr)
 175 : server(server)
 176 , conn(addr)
 177 , input()
 178 , player_model(nullptr)
 179 , spawns()
 180 , confirm_wait(0)
 181 , entity_updates()
 182 , player_update_state()
 183 , player_update_pack(0)
 184 , player_update_timer(1500)
 185 , old_actions(0)
 186 , transmitter(*this)
 187 , chunk_queue()
 188 , old_base() {
 189         conn.SetHandler(this);
 190 }
 191
 192 ClientConnection::~ClientConnection() {
 193         DetachPlayer();
 194 }
 195
 196 void ClientConnection::Update(int dt) {
 197         conn.Update(dt);
 198         if (Disconnected()) {
 199                 return;
 200         }
 201         if (HasPlayer()) {
 202                 // sync entities
 203                 auto global_iter = server.GetWorld().Entities().begin();
 204                 auto global_end = server.GetWorld().Entities().end();
 205                 auto local_iter = spawns.begin();
 206                 auto local_end = spawns.end();
 207
 208                 while (global_iter != global_end && local_iter != local_end) {
 209                         if (global_iter->ID() == local_iter->entity->ID()) {
 210                                 // they're the same
 211                                 if (CanDespawn(*global_iter)) {
 212                                         SendDespawn(*local_iter);
 213                                 } else {
 214                                         // update
 215                                         QueueUpdate(*local_iter);
 216                                 }
 217                                 ++global_iter;
 218                                 ++local_iter;
 219                         } else if (global_iter->ID() < local_iter->entity->ID()) {
 220                                 // global entity was inserted
 221                                 if (CanSpawn(*global_iter)) {
 222                                         auto spawned = spawns.emplace(local_iter, *global_iter);
 223                                         SendSpawn(*spawned);
 224                                 }
 225                                 ++global_iter;
 226                         } else {
 227                                 // global entity was removed
 228                                 SendDespawn(*local_iter);
 229                                 ++local_iter;
 230                         }
 231                 }
 232
 233                 // leftover spawns
 234                 while (global_iter != global_end) {
 235                         if (CanSpawn(*global_iter)) {
 236                                 spawns.emplace_back(*global_iter);
 237                                 SendSpawn(spawns.back());
 238                         }
 239                         ++global_iter;
 240                 }
 241
 242                 // leftover despawns
 243                 while (local_iter != local_end) {
 244                         SendDespawn(*local_iter);
 245                         ++local_iter;
 246                 }
 247                 SendUpdates();
 248
 249                 input->Update(dt);
 250                 CheckPlayerFix();
 251                 CheckChunkQueue();
 252         }
 253         if (conn.ShouldPing()) {
 254                 conn.SendPing(server.GetPacket(), server.GetSocket());
 255         }
 256 }
 257
 258 ClientConnection::SpawnStatus::SpawnStatus(Entity &e)
 259 : entity(&e)
 260 , spawn_pack(-1)
 261 , despawn_pack(-1) {
 262         entity->Ref();
 263 }
 264
 265 ClientConnection::SpawnStatus::~SpawnStatus() {
 266         entity->UnRef();
 267 }
 268
 269 bool ClientConnection::CanSpawn(const Entity &e) const noexcept {
 270         return
 271                 &e != &PlayerEntity() &&
 272                 !e.Dead() &&
 273                 manhattan_radius(e.ChunkCoords() - PlayerEntity().ChunkCoords()) < 7;
 274 }
 275
 276 bool ClientConnection::CanDespawn(const Entity &e) const noexcept {
 277         return
 278                 e.Dead() ||
 279                 manhattan_radius(e.ChunkCoords() - PlayerEntity().ChunkCoords()) > 7;
 280 }
 281
 282 uint16_t ClientConnection::Send() {
 283         return conn.Send(server.GetPacket(), server.GetSocket());
 284 }
 285
 286 uint16_t ClientConnection::Send(size_t len) {
 287         server.GetPacket().len = sizeof(Packet::Header) + len;
 288         return Send();
 289 }
 290
 291 void ClientConnection::SendSpawn(SpawnStatus &status) {
 292         // don't double spawn
 293         if (status.spawn_pack != -1) return;
 294
 295         auto pack = Prepare<Packet::SpawnEntity>();
 296         pack.WriteEntity(*status.entity);
 297         status.spawn_pack = Send();
 298         ++confirm_wait;
 299 }
 300
 301 void ClientConnection::SendDespawn(SpawnStatus &status) {
 302         // don't double despawn
 303         if (status.despawn_pack != -1) return;
 304
 305         auto pack = Prepare<Packet::DespawnEntity>();
 306         pack.WriteEntityID(status.entity->ID());
 307         status.despawn_pack = Send();
 308         ++confirm_wait;
 309 }
 310
 311 void ClientConnection::QueueUpdate(SpawnStatus &status) {
 312         // don't send updates while spawn not ack'd or despawn sent
 313         if (status.spawn_pack == -1 && status.despawn_pack == -1) {
 314                 entity_updates.push_back(&status);
 315         }
 316 }
 317
 318 void ClientConnection::SendUpdates() {
 319         auto pack = Prepare<Packet::EntityUpdate>();
 320         int entity_pos = 0;
 321         for (SpawnStatus *status : entity_updates) {
 322                 pack.WriteEntity(*status->entity, entity_pos);
 323                 ++entity_pos;
 324                 if (entity_pos == Packet::EntityUpdate::MAX_ENTITIES) {
 325                         pack.WriteEntityCount(entity_pos);
 326                         Send(Packet::EntityUpdate::GetSize(entity_pos));
 327                         pack = Prepare<Packet::EntityUpdate>();
 328                         entity_pos = 0;
 329                 }
 330         }
 331         if (entity_pos > 0) {
 332                 pack.WriteEntityCount(entity_pos);
 333                 Send(Packet::EntityUpdate::GetSize(entity_pos));
 334         }
 335         entity_updates.clear();
 336 }
 337
 338 void ClientConnection::CheckPlayerFix() {
 339         // player_update_state's position holds the client's most recent prediction
 340         glm::vec3 diff = player_update_state.Diff(PlayerEntity().GetState());
 341         float dist_squared = dot(diff, diff);
 342
 343         // if client's prediction is off by more than 1cm, send
 344         // our (authoritative) state back so it can fix it
 345         constexpr float fix_thresh = 0.0001f;
 346
 347         if (dist_squared > fix_thresh) {
 348                 auto pack = Prepare<Packet::PlayerCorrection>();
 349                 pack.WritePacketSeq(player_update_pack);
 350                 pack.WritePlayer(PlayerEntity());
 351                 Send();
 352         }
 353 }
 354
 355 void ClientConnection::CheckChunkQueue() {
 356         if (PlayerChunks().Base() != old_base) {
 357                 Chunk::Pos begin = PlayerChunks().CoordsBegin();
 358                 Chunk::Pos end = PlayerChunks().CoordsEnd();
 359                 for (Chunk::Pos pos = begin; pos.z < end.z; ++pos.z) {
 360                         for (pos.y = begin.y; pos.y < end.y; ++pos.y) {
 361                                 for (pos.x = begin.x; pos.x < end.x; ++pos.x) {
 362                                         if (manhattan_radius(pos - old_base) > PlayerChunks().Extent()) {
 363                                                 chunk_queue.push_back(pos);
 364                                         }
 365                                 }
 366                         }
 367                 }
 368                 old_base = PlayerChunks().Base();
 369         }
 370         if (transmitter.Transmitting()) {
 371                 transmitter.Transmit();
 372                 return;
 373         }
 374         if (transmitter.Idle()) {
 375                 int count = 0;
 376                 constexpr int max = 64;
 377                 while (count < max && !chunk_queue.empty()) {
 378                         Chunk::Pos pos = chunk_queue.front();
 379                         chunk_queue.pop_front();
 380                         if (PlayerChunks().InRange(pos)) {
 381                                 Chunk *chunk = PlayerChunks().Get(pos);
 382                                 if (chunk) {
 383                                         transmitter.Send(*chunk);
 384                                         return;
 385                                 } else {
 386                                         chunk_queue.push_back(pos);
 387                                 }
 388                                 ++count;
 389                         }
 390                 }
 391         }
 392 }
 393
 394 void ClientConnection::AttachPlayer(Player &player) {
 395         DetachPlayer();
 396         input.reset(new DirectInput(server.GetWorld(), player, server));
 397         PlayerEntity().Ref();
 398         if (server.GetWorldSave().Exists(player)) {
 399                 server.GetWorldSave().Read(player);
 400         }
 401
 402         old_base = PlayerChunks().Base();
 403         Chunk::Pos begin = PlayerChunks().CoordsBegin();
 404         Chunk::Pos end = PlayerChunks().CoordsEnd();
 405         for (Chunk::Pos pos = begin; pos.z < end.z; ++pos.z) {
 406                 for (pos.y = begin.y; pos.y < end.y; ++pos.y) {
 407                         for (pos.x = begin.x; pos.x < end.x; ++pos.x) {
 408                                 chunk_queue.push_back(pos);
 409                         }
 410                 }
 411         }
 412         if (HasPlayerModel()) {
 413                 GetPlayerModel().Instantiate(PlayerEntity().GetModel());
 414         }
 415
 416         cout << "player \"" << player.Name() << "\" joined" << endl;
 417 }
 418
 419 void ClientConnection::DetachPlayer() {
 420         if (!HasPlayer()) return;
 421         cout << "player \"" << input->GetPlayer().Name() << "\" left" << endl;
 422         server.GetWorldSave().Write(input->GetPlayer());
 423         PlayerEntity().Kill();
 424         PlayerEntity().UnRef();
 425         input.reset();
 426         transmitter.Abort();
 427         chunk_queue.clear();
 428         old_actions = 0;
 429 }
 430
 431 void ClientConnection::SetPlayerModel(const CompositeModel &m) noexcept {
 432         player_model = &m;
 433         if (HasPlayer()) {
 434                 m.Instantiate(PlayerEntity().GetModel());
 435         }
 436 }
 437
 438 bool ClientConnection::HasPlayerModel() const noexcept {
 439         return player_model;
 440 }
 441
 442 const CompositeModel &ClientConnection::GetPlayerModel() const noexcept {
 443         return *player_model;
 444 }
 445
 446 void ClientConnection::OnPacketReceived(uint16_t seq) {
 447         if (transmitter.Waiting()) {
 448                 transmitter.Ack(seq);
 449         }
 450         if (!confirm_wait) return;
 451         for (auto iter = spawns.begin(), end = spawns.end(); iter != end; ++iter) {
 452                 if (seq == iter->spawn_pack) {
 453                         iter->spawn_pack = -1;
 454                         --confirm_wait;
 455                         return;
 456                 }
 457                 if (seq == iter->despawn_pack) {
 458                         spawns.erase(iter);
 459                         --confirm_wait;
 460                         return;
 461                 }
 462         }
 463 }
 464
 465 void ClientConnection::OnPacketLost(uint16_t seq) {
 466         if (transmitter.Waiting()) {
 467                 transmitter.Nack(seq);
 468         }
 469         if (!confirm_wait) return;
 470         for (SpawnStatus &status : spawns) {
 471                 if (seq == status.spawn_pack) {
 472                         status.spawn_pack = -1;
 473                         --confirm_wait;
 474                         SendSpawn(status);
 475                         return;
 476                 }
 477                 if (seq == status.despawn_pack) {
 478                         status.despawn_pack = -1;
 479                         --confirm_wait;
 480                         SendDespawn(status);
 481                         return;
 482                 }
 483         }
 484 }
 485
 486 void ClientConnection::On(const Packet::Login &pack) {
 487         string name;
 488         pack.ReadPlayerName(name);
 489
 490         Player *new_player = server.GetWorld().AddPlayer(name);
 491
 492         if (new_player) {
 493                 // success!
 494                 AttachPlayer(*new_player);
 495                 cout << "accepted login from player \"" << name << '"' << endl;
 496                 auto response = Prepare<Packet::Join>();
 497                 response.WritePlayer(new_player->GetEntity());
 498                 response.WriteWorldName(server.GetWorld().Name());
 499                 Send();
 500                 // set up update tracking
 501                 player_update_state = new_player->GetEntity().GetState();
 502                 player_update_pack = pack.Seq();
 503                 player_update_timer.Reset();
 504                 player_update_timer.Start();
 505         } else {
 506                 // aw no :(
 507                 cout << "rejected login from player \"" << name << '"' << endl;
 508                 Prepare<Packet::Part>();
 509                 Send();
 510                 conn.Close();
 511         }
 512 }
 513
 514 void ClientConnection::On(const Packet::Part &) {
 515         conn.Close();
 516 }
 517
 518 void ClientConnection::On(const Packet::PlayerUpdate &pack) {
 519         if (!HasPlayer()) return;
 520         int pack_diff = int16_t(pack.Seq()) - int16_t(player_update_pack);
 521         bool overdue = player_update_timer.HitOnce();
 522         player_update_timer.Reset();
 523         if (pack_diff <= 0 && !overdue) {
 524                 // drop old packets if we have a fairly recent state
 525                 return;
 526         }
 527         glm::vec3 movement(0.0f);
 528         float pitch = 0.0f;
 529         float yaw = 0.0f;
 530         uint8_t new_actions;
 531         uint8_t slot;
 532
 533         player_update_pack = pack.Seq();
 534         pack.ReadPredictedState(player_update_state);
 535         pack.ReadMovement(movement);
 536         pack.ReadPitch(pitch);
 537         pack.ReadYaw(yaw);
 538         pack.ReadActions(new_actions);
 539         pack.ReadSlot(slot);
 540
 541         input->SetMovement(movement);
 542         input->TurnHead(pitch - input->GetPitch(), yaw - input->GetYaw());
 543         input->SelectInventory(slot);
 544
 545         if ((new_actions & 0x01) && !(old_actions & 0x01)) {
 546                 input->StartPrimaryAction();
 547         } else if (!(new_actions & 0x01) && (old_actions & 0x01)) {
 548                 input->StopPrimaryAction();
 549         }
 550         if ((new_actions & 0x02) && !(old_actions & 0x02)) {
 551                 input->StartSecondaryAction();
 552         } else if (!(new_actions & 0x02) && (old_actions & 0x02)) {
 553                 input->StopSecondaryAction();
 554         }
 555         if ((new_actions & 0x04) && !(old_actions & 0x04)) {
 556                 input->StartTertiaryAction();
 557         } else if (!(new_actions & 0x04) && (old_actions & 0x04)) {
 558                 input->StopTertiaryAction();
 559         }
 560         old_actions = new_actions;
 561 }
 562
 563 bool ClientConnection::ChunkInRange(const glm::ivec3 &pos) const noexcept {
 564         return HasPlayer() && PlayerChunks().InRange(pos);
 565 }
 566
 567
 568 Server::Server(const Config::Network &conf, World &world, const WorldSave &save)
 569 : serv_sock(nullptr)
 570 , serv_pack{ -1, nullptr, 0 }
 571 , clients()
 572 , world(world)
 573 , save(save)
 574 , player_model(nullptr) {
 575         serv_sock = SDLNet_UDP_Open(conf.port);
 576         if (!serv_sock) {
 577                 throw NetError("SDLNet_UDP_Open");
 578         }
 579
 580         serv_pack.data = new Uint8[sizeof(Packet)];
 581         serv_pack.maxlen = sizeof(Packet);
 582 }
 583
 584 Server::~Server() {
 585         delete[] serv_pack.data;
 586         SDLNet_UDP_Close(serv_sock);
 587 }
 588
 589
 590 void Server::Handle() {
 591         int result = SDLNet_UDP_Recv(serv_sock, &serv_pack);
 592         while (result > 0) {
 593                 HandlePacket(serv_pack);
 594                 result = SDLNet_UDP_Recv(serv_sock, &serv_pack);
 595         }
 596         if (result == -1) {
 597                 // a boo boo happened
 598                 throw NetError("SDLNet_UDP_Recv");
 599         }
 600 }
 601
 602 void Server::HandlePacket(const UDPpacket &udp_pack) {
 603         if (udp_pack.len < int(sizeof(Packet::Header))) {
 604                 // packet too small, drop
 605                 return;
 606         }
 607         const Packet &pack = *reinterpret_cast<const Packet *>(udp_pack.data);
 608         if (pack.header.tag != Packet::TAG) {
 609                 // mistagged packet, drop
 610                 return;
 611         }
 612
 613         ClientConnection &client = GetClient(udp_pack.address);
 614         client.GetConnection().Received(udp_pack);
 615 }
 616
 617 ClientConnection &Server::GetClient(const IPaddress &addr) {
 618         for (ClientConnection &client : clients) {
 619                 if (client.Matches(addr)) {
 620                         return client;
 621                 }
 622         }
 623         clients.emplace_back(*this, addr);
 624         if (HasPlayerModel()) {
 625                 clients.back().SetPlayerModel(GetPlayerModel());
 626         }
 627         return clients.back();
 628 }
 629
 630 void Server::Update(int dt) {
 631         for (list<ClientConnection>::iterator client(clients.begin()), end(clients.end()); client != end;) {
 632                 client->Update(dt);
 633                 if (client->Disconnected()) {
 634                         client = clients.erase(client);
 635                 } else {
 636                         ++client;
 637                 }
 638         }
 639 }
 640
 641 void Server::SetPlayerModel(const CompositeModel &m) noexcept {
 642         player_model = &m;
 643         for (ClientConnection &client : clients) {
 644                 client.SetPlayerModel(m);
 645         }
 646 }
 647
 648 bool Server::HasPlayerModel() const noexcept {
 649         return player_model;
 650 }
 651
 652 const CompositeModel &Server::GetPlayerModel() const noexcept {
 653         return *player_model;
 654 }
 655
 656 void Server::SetBlock(Chunk &chunk, int index, const Block &block) {
 657         chunk.SetBlock(index, block);
 658         // TODO: batch chunk changes
 659         auto pack = Packet::Make<Packet::BlockUpdate>(GetPacket());
 660         pack.WriteChunkCoords(chunk.Position());
 661         pack.WriteBlockCount(uint32_t(1));
 662         pack.WriteIndex(index, 0);
 663         pack.WriteBlock(chunk.BlockAt(index), 0);
 664         GetPacket().len = sizeof(Packet::Header) + Packet::BlockUpdate::GetSize(1);
 665         for (ClientConnection &client : clients) {
 666                 if (client.ChunkInRange(chunk.Position())) {
 667                         client.Send();
 668                 }
 669         }
 670 }
 671
 672 }
 673 }