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