src/net/net.cpp

   1 #include "Connection.hpp"
   2 #include "ConnectionHandler.hpp"
   3 #include "io.hpp"
   4 #include "Packet.hpp"
   5
   6 #include "../app/init.hpp"
   7 #include "../model/Model.hpp"
   8 #include "../world/Entity.hpp"
   9 #include "../world/EntityState.hpp"
  10
  11 #include <cstring>
  12
  13 using namespace std;
  14
  15
  16 namespace blank {
  17
  18 constexpr size_t Packet::Ping::MAX_LEN;
  19 constexpr size_t Packet::Login::MAX_LEN;
  20 constexpr size_t Packet::Join::MAX_LEN;
  21 constexpr size_t Packet::Part::MAX_LEN;
  22 constexpr size_t Packet::PlayerUpdate::MAX_LEN;
  23 constexpr size_t Packet::SpawnEntity::MAX_LEN;
  24 constexpr size_t Packet::DespawnEntity::MAX_LEN;
  25 constexpr size_t Packet::EntityUpdate::MAX_LEN;
  26 constexpr size_t Packet::PlayerCorrection::MAX_LEN;
  27 constexpr size_t Packet::ChunkBegin::MAX_LEN;
  28 constexpr size_t Packet::ChunkData::MAX_LEN;
  29 constexpr size_t Packet::BlockUpdate::MAX_LEN;
  30
  31 Connection::Connection(const IPaddress &addr)
  32 : handler(nullptr)
  33 , addr(addr)
  34 , send_timer(500)
  35 , recv_timer(10000)
  36 , ctrl_out{ 0, 0xFFFF, 0xFFFFFFFF }
  37 , ctrl_in{ 0, 0xFFFF, 0xFFFFFFFF }
  38 , closed(false) {
  39         send_timer.Start();
  40         recv_timer.Start();
  41 }
  42
  43 bool Connection::Matches(const IPaddress &remote) const noexcept {
  44         return memcmp(&addr, &remote, sizeof(IPaddress)) == 0;
  45 }
  46
  47 void Connection::FlagSend() noexcept {
  48         send_timer.Reset();
  49 }
  50
  51 void Connection::FlagRecv() noexcept {
  52         recv_timer.Reset();
  53 }
  54
  55 bool Connection::ShouldPing() const noexcept {
  56         return !closed && send_timer.HitOnce();
  57 }
  58
  59 bool Connection::TimedOut() const noexcept {
  60         return recv_timer.HitOnce();
  61 }
  62
  63 void Connection::Update(int dt) {
  64         send_timer.Update(dt);
  65         recv_timer.Update(dt);
  66         if (TimedOut()) {
  67                 Close();
  68                 if (HasHandler()) {
  69                         Handler().OnTimeout();
  70                 }
  71         }
  72 }
  73
  74
  75 uint16_t Connection::Send(UDPpacket &udp_pack, UDPsocket sock) {
  76         Packet &pack = *reinterpret_cast<Packet *>(udp_pack.data);
  77         pack.header.ctrl = ctrl_out;
  78         uint16_t seq = ctrl_out.seq++;
  79
  80         udp_pack.address = addr;
  81         if (SDLNet_UDP_Send(sock, -1, &udp_pack) == 0) {
  82                 throw NetError("SDLNet_UDP_Send");
  83         }
  84
  85         FlagSend();
  86         return seq;
  87 }
  88
  89 void Connection::Received(const UDPpacket &udp_pack) {
  90         Packet &pack = *reinterpret_cast<Packet *>(udp_pack.data);
  91
  92         // ack to the remote
  93         int16_t diff = int16_t(pack.header.ctrl.seq) - int16_t(ctrl_out.ack);
  94         if (diff > 0) {
  95                 if (diff >= 32) {
  96                         ctrl_out.hist = 0;
  97                 } else {
  98                         ctrl_out.hist <<= diff;
  99                         ctrl_out.hist |= 1 << (diff - 1);
 100                 }
 101         } else if (diff < 0 && diff >= -32) {
 102                 ctrl_out.hist |= 1 << (-diff - 1);
 103         }
 104         ctrl_out.ack = pack.header.ctrl.seq;
 105         FlagRecv();
 106
 107         if (!HasHandler()) {
 108                 return;
 109         }
 110
 111         Packet::TControl ctrl_new = pack.header.ctrl;
 112         Handler().Handle(udp_pack);
 113
 114         if (diff > 0) {
 115                 // if the packet holds more recent information
 116                 // check if remote failed to ack one of our packets
 117                 diff = int16_t(ctrl_new.ack) - int16_t(ctrl_in.ack);
 118                 // should always be true, but you never know…
 119                 if (diff > 0) {
 120                         for (int i = 0; i < diff; ++i) {
 121                                 if (i > 32 || (i < 32 && (ctrl_in.hist & (1 << (31 - i))) == 0)) {
 122                                         Handler().PacketLost(ctrl_in.ack - 32 + i);
 123                                 }
 124                         }
 125                 }
 126                 // check for newly ack'd packets
 127                 for (uint16_t s = ctrl_new.AckBegin(); s != ctrl_new.AckEnd(); --s) {
 128                         if (ctrl_new.Acks(s) && !ctrl_in.Acks(s)) {
 129                                 Handler().PacketReceived(s);
 130                         }
 131                 }
 132                 ctrl_in = ctrl_new;
 133         }
 134 }
 135
 136 bool Packet::TControl::Acks(uint16_t s) const noexcept {
 137         int16_t diff = int16_t(ack) - int16_t(s);
 138         if (diff == 0) return true;
 139         if (diff < 0 || diff > 32) return false;
 140         return (hist & (1 << (diff - 1))) != 0;
 141 }
 142
 143 uint16_t Connection::SendPing(UDPpacket &udp_pack, UDPsocket sock) {
 144         Packet::Make<Packet::Ping>(udp_pack);
 145         return Send(udp_pack, sock);
 146 }
 147
 148
 149 ConnectionHandler::ConnectionHandler()
 150 : packets_lost(0)
 151 , packets_received(0)
 152 , packet_loss(0.0f) {
 153
 154 }
 155
 156 void ConnectionHandler::PacketLost(uint16_t seq) {
 157         OnPacketLost(seq);
 158         ++packets_lost;
 159         UpdatePacketLoss();
 160 }
 161
 162 void ConnectionHandler::PacketReceived(uint16_t seq) {
 163         OnPacketReceived(seq);
 164         ++packets_received;
 165         UpdatePacketLoss();
 166 }
 167
 168 void ConnectionHandler::UpdatePacketLoss() noexcept {
 169         unsigned int packets_total = packets_lost + packets_received;
 170         if (packets_total >= 256) {
 171                 packet_loss = float(packets_lost) / float(packets_total);
 172                 packets_lost = 0;
 173                 packets_received = 0;
 174         }
 175 }
 176
 177
 178 ostream &operator <<(ostream &out, const IPaddress &addr) {
 179         const unsigned char *host = reinterpret_cast<const unsigned char *>(&addr.host);
 180         out << int(host[0])
 181                 << '.' << int(host[1])
 182                 << '.' << int(host[2])
 183                 << '.' << int(host[3]);
 184         if (addr.port) {
 185                 out << ':' << SDLNet_Read16(&addr.port);
 186         }
 187         return out;
 188 }
 189
 190
 191 const char *Packet::Type2String(uint8_t t) noexcept {
 192         switch (t) {
 193                 case Ping::TYPE:
 194                         return "Ping";
 195                 case Login::TYPE:
 196                         return "Login";
 197                 case Join::TYPE:
 198                         return "Join";
 199                 case Part::TYPE:
 200                         return "Part";
 201                 case PlayerUpdate::TYPE:
 202                         return "PlayerUpdate";
 203                 case SpawnEntity::TYPE:
 204                         return "SpawnEntity";
 205                 case DespawnEntity::TYPE:
 206                         return "DespawnEntity";
 207                 case EntityUpdate::TYPE:
 208                         return "EntityUpdate";
 209                 case PlayerCorrection::TYPE:
 210                         return "PlayerCorrection";
 211                 case ChunkBegin::TYPE:
 212                         return "ChunkBegin";
 213                 case ChunkData::TYPE:
 214                         return "ChunkData";
 215                 case BlockUpdate::TYPE:
 216                         return "BlockUpdate";
 217                 default:
 218                         return "Unknown";
 219         }
 220 }
 221
 222 template<class T>
 223 void Packet::Payload::Write(const T &src, size_t off) noexcept {
 224         if ((length - off) < sizeof(T)) {
 225                 // dismiss out of bounds write
 226                 return;
 227         }
 228         *reinterpret_cast<T *>(&data[off]) = src;
 229 }
 230
 231 template<class T>
 232 void Packet::Payload::Read(T &dst, size_t off) const noexcept {
 233         if ((length - off) < sizeof(T)) {
 234                 // dismiss out of bounds read
 235                 return;
 236         }
 237         dst = *reinterpret_cast<T *>(&data[off]);
 238 }
 239
 240 void Packet::Payload::WriteString(const string &src, size_t off, size_t maxlen) noexcept {
 241         uint8_t *dst = &data[off];
 242         size_t len = min(maxlen, length - off);
 243         if (src.size() < len) {
 244                 memset(dst, '\0', len);
 245                 memcpy(dst, src.c_str(), src.size());
 246         } else {
 247                 memcpy(dst, src.c_str(), len);
 248         }
 249 }
 250
 251 void Packet::Payload::ReadString(string &dst, size_t off, size_t maxlen) const noexcept {
 252         size_t len = min(maxlen, length - off);
 253         dst.clear();
 254         dst.reserve(len);
 255         for (size_t i = 0; i < len && data[off + i] != '\0'; ++i) {
 256                 dst.push_back(data[off + i]);
 257         }
 258 }
 259
 260
 261 void Packet::Login::WritePlayerName(const string &name) noexcept {
 262         WriteString(name, 0, 32);
 263 }
 264
 265 void Packet::Login::ReadPlayerName(string &name) const noexcept {
 266         ReadString(name, 0, 32);
 267 }
 268
 269 void Packet::Join::WritePlayer(const Entity &player) noexcept {
 270         Write(player.ID(), 0);
 271         Write(player.GetState(), 4);
 272 }
 273
 274 void Packet::Join::ReadPlayerID(uint32_t &id) const noexcept {
 275         Read(id, 0);
 276 }
 277
 278 void Packet::Join::ReadPlayerState(EntityState &state) const noexcept {
 279         Read(state, 4);
 280 }
 281
 282 void Packet::Join::WriteWorldName(const string &name) noexcept {
 283         WriteString(name, 68, 32);
 284 }
 285
 286 void Packet::Join::ReadWorldName(string &name) const noexcept {
 287         ReadString(name, 68, 32);
 288 }
 289
 290 void Packet::PlayerUpdate::WritePredictedState(const EntityState &state) noexcept {
 291         Write(state, 0);
 292 }
 293
 294 void Packet::PlayerUpdate::ReadPredictedState(EntityState &state) const noexcept {
 295         Read(state, 0);
 296 }
 297
 298 void Packet::PlayerUpdate::WriteMovement(const glm::vec3 &mov) noexcept {
 299         glm::ivec3 conv = clamp(glm::ivec3(mov * 32767.0f), -32767, 32767);
 300         Write(int16_t(conv.x), 64);
 301         Write(int16_t(conv.y), 66);
 302         Write(int16_t(conv.z), 68);
 303 }
 304
 305 void Packet::PlayerUpdate::ReadMovement(glm::vec3 &mov) const noexcept {
 306         int16_t x, y, z;
 307         Read(x, 64);
 308         Read(y, 66);
 309         Read(z, 68);
 310         mov = glm::vec3(x, y, z) * .00003051850947599719f;
 311 }
 312
 313 void Packet::PlayerUpdate::WritePitch(float pitch) noexcept {
 314         int16_t conv = pitch * 20860.12008116853786870640f;
 315         Write(conv, 70);
 316 }
 317
 318 void Packet::PlayerUpdate::ReadPitch(float &pitch) const noexcept {
 319         int16_t conv = 0;
 320         Read(conv, 70);
 321         pitch = conv * .00004793836258415163f;
 322 }
 323
 324 void Packet::PlayerUpdate::WriteYaw(float yaw) noexcept {
 325         int16_t conv = yaw * 10430.06004058426893435320f;
 326         Write(conv, 72);
 327 }
 328
 329 void Packet::PlayerUpdate::ReadYaw(float &yaw) const noexcept {
 330         int16_t conv = 0;
 331         Read(conv, 72);
 332         yaw = conv * .00009587672516830326f;
 333 }
 334
 335 void Packet::PlayerUpdate::WriteActions(uint8_t actions) noexcept {
 336         Write(actions, 74);
 337 }
 338
 339 void Packet::PlayerUpdate::ReadActions(uint8_t &actions) const noexcept {
 340         Read(actions, 74);
 341 }
 342
 343 void Packet::PlayerUpdate::WriteSlot(uint8_t slot) noexcept {
 344         Write(slot, 75);
 345 }
 346
 347 void Packet::PlayerUpdate::ReadSlot(uint8_t &slot) const noexcept {
 348         Read(slot, 75);
 349 }
 350
 351 void Packet::SpawnEntity::WriteEntity(const Entity &e) noexcept {
 352         Write(e.ID(), 0);
 353         if (e.GetModel()) {
 354                 Write(e.GetModel().GetModel().ID(), 4);
 355         } else {
 356                 Write(uint32_t(0), 4);
 357         }
 358         Write(e.GetState(), 8);
 359         Write(e.Bounds(), 72);
 360         uint32_t flags = 0;
 361         if (e.WorldCollidable()) {
 362                 flags |= 1;
 363         }
 364         Write(flags, 96);
 365         WriteString(e.Name(), 100, 32);
 366 }
 367
 368 void Packet::SpawnEntity::ReadEntityID(uint32_t &id) const noexcept {
 369         Read(id, 0);
 370 }
 371
 372 void Packet::SpawnEntity::ReadSkeletonID(uint32_t &id) const noexcept {
 373         Read(id, 4);
 374 }
 375
 376 void Packet::SpawnEntity::ReadEntity(Entity &e) const noexcept {
 377         EntityState state;
 378         AABB bounds;
 379         uint32_t flags = 0;
 380         string name;
 381
 382         Read(state, 8);
 383         Read(bounds, 72);
 384         Read(flags, 96);
 385         ReadString(name, 100, 32);
 386
 387         e.SetState(state);
 388         e.Bounds(bounds);
 389         e.WorldCollidable(flags & 1);
 390         e.Name(name);
 391 }
 392
 393 void Packet::DespawnEntity::WriteEntityID(uint32_t id) noexcept {
 394         Write(id, 0);
 395 }
 396
 397 void Packet::DespawnEntity::ReadEntityID(uint32_t &id) const noexcept {
 398         Read(id, 0);
 399 }
 400
 401 void Packet::EntityUpdate::WriteEntityCount(uint32_t count) noexcept {
 402         Write(count, 0);
 403 }
 404
 405 void Packet::EntityUpdate::ReadEntityCount(uint32_t &count) const noexcept {
 406         Read(count, 0);
 407 }
 408
 409 void Packet::EntityUpdate::WriteEntity(const Entity &entity, uint32_t num) noexcept {
 410         uint32_t off = GetSize(num);
 411
 412         Write(entity.ID(), off);
 413         Write(entity.GetState(), off + 4);
 414 }
 415
 416 void Packet::EntityUpdate::ReadEntityID(uint32_t &id, uint32_t num) const noexcept {
 417         uint32_t off = GetSize(num);
 418         Read(id, off);
 419 }
 420
 421 void Packet::EntityUpdate::ReadEntityState(EntityState &state, uint32_t num) const noexcept {
 422         uint32_t off = GetSize(num);
 423         Read(state, off + 4);
 424 }
 425
 426 void Packet::PlayerCorrection::WritePacketSeq(std::uint16_t s) noexcept {
 427         Write(s, 0);
 428 }
 429
 430 void Packet::PlayerCorrection::ReadPacketSeq(std::uint16_t &s) const noexcept {
 431         Read(s, 0);
 432 }
 433
 434 void Packet::PlayerCorrection::WritePlayer(const Entity &player) noexcept {
 435         Write(player.GetState(), 2);
 436 }
 437
 438 void Packet::PlayerCorrection::ReadPlayerState(EntityState &state) const noexcept {
 439         Read(state, 2);
 440 }
 441
 442 void Packet::ChunkBegin::WriteTransmissionId(uint32_t id) noexcept {
 443         Write(id, 0);
 444 }
 445
 446 void Packet::ChunkBegin::ReadTransmissionId(uint32_t &id) const noexcept {
 447         Read(id, 0);
 448 }
 449
 450 void Packet::ChunkBegin::WriteFlags(uint32_t f) noexcept {
 451         Write(f, 4);
 452 }
 453
 454 void Packet::ChunkBegin::ReadFlags(uint32_t &f) const noexcept {
 455         Read(f, 4);
 456 }
 457
 458 void Packet::ChunkBegin::WriteChunkCoords(const glm::ivec3 &pos) noexcept {
 459         Write(pos, 8);
 460 }
 461
 462 void Packet::ChunkBegin::ReadChunkCoords(glm::ivec3 &pos) const noexcept {
 463         Read(pos, 8);
 464 }
 465
 466 void Packet::ChunkBegin::WriteDataSize(uint32_t s) noexcept {
 467         Write(s, 20);
 468 }
 469
 470 void Packet::ChunkBegin::ReadDataSize(uint32_t &s) const noexcept {
 471         Read(s, 20);
 472 }
 473
 474 void Packet::ChunkData::WriteTransmissionId(uint32_t id) noexcept {
 475         Write(id, 0);
 476 }
 477
 478 void Packet::ChunkData::ReadTransmissionId(uint32_t &id) const noexcept {
 479         Read(id, 0);
 480 }
 481
 482 void Packet::ChunkData::WriteDataOffset(uint32_t o) noexcept {
 483         Write(o, 4);
 484 }
 485
 486 void Packet::ChunkData::ReadDataOffset(uint32_t &o) const noexcept {
 487         Read(o, 4);
 488 }
 489
 490 void Packet::ChunkData::WriteDataSize(uint32_t s) noexcept {
 491         Write(s, 8);
 492 }
 493
 494 void Packet::ChunkData::ReadDataSize(uint32_t &s) const noexcept {
 495         Read(s, 8);
 496 }
 497
 498 void Packet::ChunkData::WriteData(const uint8_t *d, size_t l) noexcept {
 499         size_t len = min(length - 12, l);
 500         memcpy(&data[12], d, len);
 501 }
 502
 503 void Packet::ChunkData::ReadData(uint8_t *d, size_t l) const noexcept {
 504         size_t len = min(length - 12, l);
 505         memcpy(d, &data[12], len);
 506 }
 507
 508 void Packet::BlockUpdate::WriteChunkCoords(const glm::ivec3 &coords) noexcept {
 509         Write(coords, 0);
 510 }
 511
 512 void Packet::BlockUpdate::ReadChunkCoords(glm::ivec3 &coords) const noexcept {
 513         Read(coords, 0);
 514 }
 515
 516 void Packet::BlockUpdate::WriteBlockCount(uint32_t count) noexcept {
 517         Write(count, 12);
 518 }
 519
 520 void Packet::BlockUpdate::ReadBlockCount(uint32_t &count) const noexcept {
 521         Read(count, 12);
 522 }
 523
 524 void Packet::BlockUpdate::WriteIndex(uint16_t index, uint32_t num) noexcept {
 525         uint32_t off = GetSize(num);
 526         Write(index, off);
 527 }
 528
 529 void Packet::BlockUpdate::ReadIndex(uint16_t &index, uint32_t num) const noexcept {
 530         uint32_t off = GetSize(num);
 531         Read(index, off);
 532 }
 533
 534 void Packet::BlockUpdate::WriteBlock(const Block &block, uint32_t num) noexcept {
 535         uint32_t off = GetSize(num) + 2;
 536         Write(block, off);
 537 }
 538
 539 void Packet::BlockUpdate::ReadBlock(Block &block, uint32_t num) const noexcept {
 540         uint32_t off = GetSize(num) + 2;
 541         Read(block, off);
 542 }
 543
 544
 545 void ConnectionHandler::Handle(const UDPpacket &udp_pack) {
 546         const Packet &pack = *reinterpret_cast<const Packet *>(udp_pack.data);
 547         switch (pack.Type()) {
 548                 case Packet::Ping::TYPE:
 549                         On(Packet::As<Packet::Ping>(udp_pack));
 550                         break;
 551                 case Packet::Login::TYPE:
 552                         On(Packet::As<Packet::Login>(udp_pack));
 553                         break;
 554                 case Packet::Join::TYPE:
 555                         On(Packet::As<Packet::Join>(udp_pack));
 556                         break;
 557                 case Packet::Part::TYPE:
 558                         On(Packet::As<Packet::Part>(udp_pack));
 559                         break;
 560                 case Packet::PlayerUpdate::TYPE:
 561                         On(Packet::As<Packet::PlayerUpdate>(udp_pack));
 562                         break;
 563                 case Packet::SpawnEntity::TYPE:
 564                         On(Packet::As<Packet::SpawnEntity>(udp_pack));
 565                         break;
 566                 case Packet::DespawnEntity::TYPE:
 567                         On(Packet::As<Packet::DespawnEntity>(udp_pack));
 568                         break;
 569                 case Packet::EntityUpdate::TYPE:
 570                         On(Packet::As<Packet::EntityUpdate>(udp_pack));
 571                         break;
 572                 case Packet::PlayerCorrection::TYPE:
 573                         On(Packet::As<Packet::PlayerCorrection>(udp_pack));
 574                         break;
 575                 case Packet::ChunkBegin::TYPE:
 576                         On(Packet::As<Packet::ChunkBegin>(udp_pack));
 577                         break;
 578                 case Packet::ChunkData::TYPE:
 579                         On(Packet::As<Packet::ChunkData>(udp_pack));
 580                         break;
 581                 case Packet::BlockUpdate::TYPE:
 582                         On(Packet::As<Packet::BlockUpdate>(udp_pack));
 583                         break;
 584                 default:
 585                         // drop unknown or unhandled packets
 586                         break;
 587         }
 588 }
 589
 590 }