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().OnPacketLost(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().OnPacketReceived(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 ostream &operator <<(ostream &out, const IPaddress &addr) {
 149         const unsigned char *host = reinterpret_cast<const unsigned char *>(&addr.host);
 150         out << int(host[0])
 151                 << '.' << int(host[1])
 152                 << '.' << int(host[2])
 153                 << '.' << int(host[3]);
 154         if (addr.port) {
 155                 out << ':' << SDLNet_Read16(&addr.port);
 156         }
 157         return out;
 158 }
 159
 160
 161 const char *Packet::Type2String(uint8_t t) noexcept {
 162         switch (t) {
 163                 case Ping::TYPE:
 164                         return "Ping";
 165                 case Login::TYPE:
 166                         return "Login";
 167                 case Join::TYPE:
 168                         return "Join";
 169                 case Part::TYPE:
 170                         return "Part";
 171                 case PlayerUpdate::TYPE:
 172                         return "PlayerUpdate";
 173                 case SpawnEntity::TYPE:
 174                         return "SpawnEntity";
 175                 case DespawnEntity::TYPE:
 176                         return "DespawnEntity";
 177                 case EntityUpdate::TYPE:
 178                         return "EntityUpdate";
 179                 case PlayerCorrection::TYPE:
 180                         return "PlayerCorrection";
 181                 case ChunkBegin::TYPE:
 182                         return "ChunkBegin";
 183                 case ChunkData::TYPE:
 184                         return "ChunkData";
 185                 default:
 186                         return "Unknown";
 187         }
 188 }
 189
 190 template<class T>
 191 void Packet::Payload::Write(const T &src, size_t off) noexcept {
 192         if ((length - off) < sizeof(T)) {
 193                 // dismiss out of bounds write
 194                 return;
 195         }
 196         *reinterpret_cast<T *>(&data[off]) = src;
 197 }
 198
 199 template<class T>
 200 void Packet::Payload::Read(T &dst, size_t off) const noexcept {
 201         if ((length - off) < sizeof(T)) {
 202                 // dismiss out of bounds read
 203                 return;
 204         }
 205         dst = *reinterpret_cast<T *>(&data[off]);
 206 }
 207
 208 void Packet::Payload::WriteString(const string &src, size_t off, size_t maxlen) noexcept {
 209         uint8_t *dst = &data[off];
 210         size_t len = min(maxlen, length - off);
 211         if (src.size() < len) {
 212                 memset(dst, '\0', len);
 213                 memcpy(dst, src.c_str(), src.size());
 214         } else {
 215                 memcpy(dst, src.c_str(), len);
 216         }
 217 }
 218
 219 void Packet::Payload::ReadString(string &dst, size_t off, size_t maxlen) const noexcept {
 220         size_t len = min(maxlen, length - off);
 221         dst.clear();
 222         dst.reserve(len);
 223         for (size_t i = 0; i < len && data[off + i] != '\0'; ++i) {
 224                 dst.push_back(data[off + i]);
 225         }
 226 }
 227
 228
 229 void Packet::Login::WritePlayerName(const string &name) noexcept {
 230         WriteString(name, 0, 32);
 231 }
 232
 233 void Packet::Login::ReadPlayerName(string &name) const noexcept {
 234         ReadString(name, 0, 32);
 235 }
 236
 237 void Packet::Join::WritePlayer(const Entity &player) noexcept {
 238         Write(player.ID(), 0);
 239         Write(player.GetState(), 4);
 240 }
 241
 242 void Packet::Join::ReadPlayerID(uint32_t &id) const noexcept {
 243         Read(id, 0);
 244 }
 245
 246 void Packet::Join::ReadPlayerState(EntityState &state) const noexcept {
 247         Read(state, 4);
 248 }
 249
 250 void Packet::Join::WriteWorldName(const string &name) noexcept {
 251         WriteString(name, 68, 32);
 252 }
 253
 254 void Packet::Join::ReadWorldName(string &name) const noexcept {
 255         ReadString(name, 68, 32);
 256 }
 257
 258 void Packet::PlayerUpdate::WritePlayer(const Entity &player) noexcept {
 259         Write(player.GetState(), 0);
 260 }
 261
 262 void Packet::PlayerUpdate::ReadPlayerState(EntityState &state) const noexcept {
 263         Read(state, 0);
 264 }
 265
 266 void Packet::SpawnEntity::WriteEntity(const Entity &e) noexcept {
 267         Write(e.ID(), 0);
 268         if (e.GetModel()) {
 269                 Write(e.GetModel().GetModel().ID(), 4);
 270         } else {
 271                 Write(uint32_t(0), 4);
 272         }
 273         Write(e.GetState(), 8);
 274         Write(e.Bounds(), 72);
 275         uint32_t flags = 0;
 276         if (e.WorldCollidable()) {
 277                 flags |= 1;
 278         }
 279         Write(flags, 96);
 280         WriteString(e.Name(), 100, 32);
 281 }
 282
 283 void Packet::SpawnEntity::ReadEntityID(uint32_t &id) const noexcept {
 284         Read(id, 0);
 285 }
 286
 287 void Packet::SpawnEntity::ReadSkeletonID(uint32_t &id) const noexcept {
 288         Read(id, 4);
 289 }
 290
 291 void Packet::SpawnEntity::ReadEntity(Entity &e) const noexcept {
 292         EntityState state;
 293         AABB bounds;
 294         uint32_t flags = 0;
 295         string name;
 296
 297         Read(state, 8);
 298         Read(bounds, 72);
 299         Read(flags, 96);
 300         ReadString(name, 100, 32);
 301
 302         e.SetState(state);
 303         e.Bounds(bounds);
 304         e.WorldCollidable(flags & 1);
 305         e.Name(name);
 306 }
 307
 308 void Packet::DespawnEntity::WriteEntityID(uint32_t id) noexcept {
 309         Write(id, 0);
 310 }
 311
 312 void Packet::DespawnEntity::ReadEntityID(uint32_t &id) const noexcept {
 313         Read(id, 0);
 314 }
 315
 316 void Packet::EntityUpdate::WriteEntityCount(uint32_t count) noexcept {
 317         Write(count, 0);
 318 }
 319
 320 void Packet::EntityUpdate::ReadEntityCount(uint32_t &count) const noexcept {
 321         Read(count, 0);
 322 }
 323
 324 void Packet::EntityUpdate::WriteEntity(const Entity &entity, uint32_t num) noexcept {
 325         uint32_t off = 4 + (num * 64);
 326
 327         Write(entity.ID(), off);
 328         Write(entity.GetState(), off + 4);
 329 }
 330
 331 void Packet::EntityUpdate::ReadEntityID(uint32_t &id, uint32_t num) const noexcept {
 332         Read(id, 4 + (num * 64));
 333 }
 334
 335 void Packet::EntityUpdate::ReadEntityState(EntityState &state, uint32_t num) const noexcept {
 336         uint32_t off = 4 + (num * 64);
 337         Read(state, off + 4);
 338 }
 339
 340 void Packet::PlayerCorrection::WritePacketSeq(std::uint16_t s) noexcept {
 341         Write(s, 0);
 342 }
 343
 344 void Packet::PlayerCorrection::ReadPacketSeq(std::uint16_t &s) const noexcept {
 345         Read(s, 0);
 346 }
 347
 348 void Packet::PlayerCorrection::WritePlayer(const Entity &player) noexcept {
 349         Write(player.GetState(), 2);
 350 }
 351
 352 void Packet::PlayerCorrection::ReadPlayerState(EntityState &state) const noexcept {
 353         Read(state, 2);
 354 }
 355
 356 void Packet::ChunkBegin::WriteTransmissionId(uint32_t id) noexcept {
 357         Write(id, 0);
 358 }
 359
 360 void Packet::ChunkBegin::ReadTransmissionId(uint32_t &id) const noexcept {
 361         Read(id, 0);
 362 }
 363
 364 void Packet::ChunkBegin::WriteFlags(uint32_t f) noexcept {
 365         Write(f, 4);
 366 }
 367
 368 void Packet::ChunkBegin::ReadFlags(uint32_t &f) const noexcept {
 369         Read(f, 4);
 370 }
 371
 372 void Packet::ChunkBegin::WriteChunkCoords(const glm::ivec3 &pos) noexcept {
 373         Write(pos, 8);
 374 }
 375
 376 void Packet::ChunkBegin::ReadChunkCoords(glm::ivec3 &pos) const noexcept {
 377         Read(pos, 8);
 378 }
 379
 380 void Packet::ChunkBegin::WriteDataSize(uint32_t s) noexcept {
 381         Write(s, 20);
 382 }
 383
 384 void Packet::ChunkBegin::ReadDataSize(uint32_t &s) const noexcept {
 385         Read(s, 20);
 386 }
 387
 388 void Packet::ChunkData::WriteTransmissionId(uint32_t id) noexcept {
 389         Write(id, 0);
 390 }
 391
 392 void Packet::ChunkData::ReadTransmissionId(uint32_t &id) const noexcept {
 393         Read(id, 0);
 394 }
 395
 396 void Packet::ChunkData::WriteDataOffset(uint32_t o) noexcept {
 397         Write(o, 4);
 398 }
 399
 400 void Packet::ChunkData::ReadDataOffset(uint32_t &o) const noexcept {
 401         Read(o, 4);
 402 }
 403
 404 void Packet::ChunkData::WriteDataSize(uint32_t s) noexcept {
 405         Write(s, 8);
 406 }
 407
 408 void Packet::ChunkData::ReadDataSize(uint32_t &s) const noexcept {
 409         Read(s, 8);
 410 }
 411
 412 void Packet::ChunkData::WriteData(const uint8_t *d, size_t l) noexcept {
 413         size_t len = min(length - 12, l);
 414         memcpy(&data[12], d, len);
 415 }
 416
 417 void Packet::ChunkData::ReadData(uint8_t *d, size_t l) const noexcept {
 418         size_t len = min(length - 12, l);
 419         memcpy(d, &data[12], len);
 420 }
 421
 422
 423 void ConnectionHandler::Handle(const UDPpacket &udp_pack) {
 424         const Packet &pack = *reinterpret_cast<const Packet *>(udp_pack.data);
 425         switch (pack.Type()) {
 426                 case Packet::Ping::TYPE:
 427                         On(Packet::As<Packet::Ping>(udp_pack));
 428                         break;
 429                 case Packet::Login::TYPE:
 430                         On(Packet::As<Packet::Login>(udp_pack));
 431                         break;
 432                 case Packet::Join::TYPE:
 433                         On(Packet::As<Packet::Join>(udp_pack));
 434                         break;
 435                 case Packet::Part::TYPE:
 436                         On(Packet::As<Packet::Part>(udp_pack));
 437                         break;
 438                 case Packet::PlayerUpdate::TYPE:
 439                         On(Packet::As<Packet::PlayerUpdate>(udp_pack));
 440                         break;
 441                 case Packet::SpawnEntity::TYPE:
 442                         On(Packet::As<Packet::SpawnEntity>(udp_pack));
 443                         break;
 444                 case Packet::DespawnEntity::TYPE:
 445                         On(Packet::As<Packet::DespawnEntity>(udp_pack));
 446                         break;
 447                 case Packet::EntityUpdate::TYPE:
 448                         On(Packet::As<Packet::EntityUpdate>(udp_pack));
 449                         break;
 450                 case Packet::PlayerCorrection::TYPE:
 451                         On(Packet::As<Packet::PlayerCorrection>(udp_pack));
 452                         break;
 453                 case Packet::ChunkBegin::TYPE:
 454                         On(Packet::As<Packet::ChunkBegin>(udp_pack));
 455                         break;
 456                 case Packet::ChunkData::TYPE:
 457                         On(Packet::As<Packet::ChunkData>(udp_pack));
 458                         break;
 459                 default:
 460                         // drop unknown or unhandled packets
 461                         break;
 462         }
 463 }
 464
 465 }