src/net/net.cpp

   1 #include "Client.hpp"
   2 #include "ClientConnection.hpp"
   3 #include "Connection.hpp"
   4 #include "ConnectionHandler.hpp"
   5 #include "io.hpp"
   6 #include "Packet.hpp"
   7 #include "Server.hpp"
   8
   9 #include "../app/init.hpp"
  10 #include "../world/World.hpp"
  11
  12 #include <cstring>
  13 #include <iostream>
  14 #include <glm/gtx/io.hpp>
  15
  16 using namespace std;
  17
  18
  19 namespace blank {
  20
  21 constexpr size_t Packet::Ping::MAX_LEN;
  22 constexpr size_t Packet::Login::MAX_LEN;
  23 constexpr size_t Packet::Join::MAX_LEN;
  24 constexpr size_t Packet::Part::MAX_LEN;
  25 constexpr size_t Packet::PlayerUpdate::MAX_LEN;
  26
  27 namespace {
  28
  29 UDPsocket client_bind(Uint16 port) {
  30         UDPsocket sock = SDLNet_UDP_Open(port);
  31         if (!sock) {
  32                 throw NetError("SDLNet_UDP_Open");
  33         }
  34         return sock;
  35 }
  36
  37 IPaddress client_resolve(const char *host, Uint16 port) {
  38         IPaddress addr;
  39         if (SDLNet_ResolveHost(&addr, host, port) != 0) {
  40                 throw NetError("SDLNet_ResolveHost");
  41         }
  42         return addr;
  43 }
  44
  45 }
  46
  47 Client::Client(const Config &conf)
  48 : conn(client_resolve(conf.host.c_str(), conf.port))
  49 , client_sock(client_bind(0))
  50 , client_pack{ -1, nullptr, 0 } {
  51         client_pack.data = new Uint8[sizeof(Packet)];
  52         client_pack.maxlen = sizeof(Packet);
  53         // establish connection
  54         SendPing();
  55 }
  56
  57 Client::~Client() {
  58         delete[] client_pack.data;
  59         SDLNet_UDP_Close(client_sock);
  60 }
  61
  62
  63 void Client::Handle() {
  64         int result = SDLNet_UDP_Recv(client_sock, &client_pack);
  65         while (result > 0) {
  66                 HandlePacket(client_pack);
  67                 result = SDLNet_UDP_Recv(client_sock, &client_pack);
  68         }
  69         if (result == -1) {
  70                 // a boo boo happened
  71                 throw NetError("SDLNet_UDP_Recv");
  72         }
  73 }
  74
  75 void Client::HandlePacket(const UDPpacket &udp_pack) {
  76         if (!conn.Matches(udp_pack.address)) {
  77                 // packet came from somewhere else, drop
  78                 return;
  79         }
  80         const Packet &pack = *reinterpret_cast<const Packet *>(udp_pack.data);
  81         if (pack.header.tag != Packet::TAG) {
  82                 // mistagged packet, drop
  83                 return;
  84         }
  85
  86         conn.Received(udp_pack);
  87 }
  88
  89 void Client::Update(int dt) {
  90         conn.Update(dt);
  91         if (conn.ShouldPing()) {
  92                 SendPing();
  93         }
  94 }
  95
  96 uint16_t Client::SendPing() {
  97         return conn.SendPing(client_pack, client_sock);
  98 }
  99
 100 uint16_t Client::SendLogin(const string &name) {
 101         auto pack = Packet::Make<Packet::Login>(client_pack);
 102         pack.WritePlayerName(name);
 103         return conn.Send(client_pack, client_sock);
 104 }
 105
 106 uint16_t Client::SendPlayerUpdate(const Entity &player) {
 107         auto pack = Packet::Make<Packet::PlayerUpdate>(client_pack);
 108         pack.WritePlayer(player);
 109         return conn.Send(client_pack, client_sock);
 110 }
 111
 112
 113 ClientConnection::ClientConnection(Server &server, const IPaddress &addr)
 114 : server(server)
 115 , conn(addr)
 116 , player(nullptr) {
 117         conn.SetHandler(this);
 118 }
 119
 120 ClientConnection::~ClientConnection() {
 121         DetachPlayer();
 122 }
 123
 124 void ClientConnection::Update(int dt) {
 125         conn.Update(dt);
 126         if (Disconnected()) {
 127                 cout << "disconnect from " << conn.Address() << endl;
 128         } else if (conn.ShouldPing()) {
 129                 conn.SendPing(server.GetPacket(), server.GetSocket());
 130         }
 131 }
 132
 133 void ClientConnection::AttachPlayer(Entity &new_player) {
 134         DetachPlayer();
 135         player = &new_player;
 136         player->Ref();
 137 }
 138
 139 void ClientConnection::DetachPlayer() {
 140         if (!player) return;
 141         player->Kill();
 142         player->UnRef();
 143         player = nullptr;
 144 }
 145
 146 void ClientConnection::On(const Packet::Login &pack) {
 147         string name;
 148         pack.ReadPlayerName(name);
 149
 150         Entity *new_player = server.GetWorld().AddPlayer(name);
 151
 152         if (new_player) {
 153                 // success!
 154                 AttachPlayer(*new_player);
 155                 cout << "accepted login from player \"" << name << '"' << endl;
 156                 auto response = Packet::Make<Packet::Join>(server.GetPacket());
 157                 response.WritePlayer(*new_player);
 158                 response.WriteWorldName(server.GetWorld().Name());
 159                 conn.Send(server.GetPacket(), server.GetSocket());
 160         } else {
 161                 // aw no :(
 162                 cout << "rejected login from player \"" << name << '"' << endl;
 163                 Packet::Make<Packet::Part>(server.GetPacket());
 164                 conn.Send(server.GetPacket(), server.GetSocket());
 165                 conn.Close();
 166         }
 167 }
 168
 169 void ClientConnection::On(const Packet::Part &) {
 170         conn.Close();
 171 }
 172
 173 void ClientConnection::On(const Packet::PlayerUpdate &pack) {
 174         if (!HasPlayer()) return;
 175         pack.ReadPlayer(Player());
 176 }
 177
 178
 179 Connection::Connection(const IPaddress &addr)
 180 : handler(nullptr)
 181 , addr(addr)
 182 , send_timer(500)
 183 , recv_timer(10000)
 184 , ctrl_out{ 0, 0xFFFF, 0xFFFFFFFF }
 185 , ctrl_in{ 0, 0xFFFF, 0xFFFFFFFF }
 186 , closed(false) {
 187         send_timer.Start();
 188         recv_timer.Start();
 189 }
 190
 191 bool Connection::Matches(const IPaddress &remote) const noexcept {
 192         return memcmp(&addr, &remote, sizeof(IPaddress)) == 0;
 193 }
 194
 195 void Connection::FlagSend() noexcept {
 196         send_timer.Reset();
 197 }
 198
 199 void Connection::FlagRecv() noexcept {
 200         recv_timer.Reset();
 201 }
 202
 203 bool Connection::ShouldPing() const noexcept {
 204         return !closed && send_timer.HitOnce();
 205 }
 206
 207 bool Connection::TimedOut() const noexcept {
 208         return recv_timer.HitOnce();
 209 }
 210
 211 void Connection::Update(int dt) {
 212         send_timer.Update(dt);
 213         recv_timer.Update(dt);
 214         if (TimedOut()) {
 215                 Close();
 216                 if (HasHandler()) {
 217                         Handler().OnTimeout();
 218                 }
 219         }
 220 }
 221
 222
 223 uint16_t Connection::Send(UDPpacket &udp_pack, UDPsocket sock) {
 224         Packet &pack = *reinterpret_cast<Packet *>(udp_pack.data);
 225         pack.header.ctrl = ctrl_out;
 226         uint16_t seq = ctrl_out.seq++;
 227
 228         udp_pack.address = addr;
 229         if (SDLNet_UDP_Send(sock, -1, &udp_pack) == 0) {
 230                 throw NetError("SDLNet_UDP_Send");
 231         }
 232
 233         FlagSend();
 234         return seq;
 235 }
 236
 237 void Connection::Received(const UDPpacket &udp_pack) {
 238         Packet &pack = *reinterpret_cast<Packet *>(udp_pack.data);
 239
 240         // ack to the remote
 241         int16_t diff = int16_t(pack.header.ctrl.seq) - int16_t(ctrl_out.ack);
 242         if (diff > 0) {
 243                 if (diff >= 32) {
 244                         ctrl_out.hist = 0;
 245                 } else {
 246                         ctrl_out.hist <<= diff;
 247                         ctrl_out.hist |= 1 << (diff - 1);
 248                 }
 249         } else if (diff < 0 && diff >= -32) {
 250                 ctrl_out.hist |= 1 << (-diff - 1);
 251         }
 252         ctrl_out.ack = pack.header.ctrl.seq;
 253         FlagRecv();
 254
 255         if (!HasHandler()) {
 256                 return;
 257         }
 258
 259         Packet::TControl ctrl_new = pack.header.ctrl;
 260         Handler().Handle(udp_pack);
 261
 262         if (diff > 0) {
 263                 // if the packet holds more recent information
 264                 // check if remote failed to ack one of our packets
 265                 diff = int16_t(ctrl_new.ack) - int16_t(ctrl_in.ack);
 266                 // should always be true, but you never know…
 267                 if (diff > 0) {
 268                         for (int i = 0; i < diff; ++i) {
 269                                 if (i > 32 || (i < 32 && (ctrl_in.hist & (1 << (31 - i))) == 0)) {
 270                                         Handler().OnPacketLost(ctrl_in.ack - 32 + i);
 271                                 }
 272                         }
 273                 }
 274                 ctrl_in = ctrl_new;
 275         }
 276 }
 277
 278 uint16_t Connection::SendPing(UDPpacket &udp_pack, UDPsocket sock) {
 279         Packet::Make<Packet::Ping>(udp_pack);
 280         return Send(udp_pack, sock);
 281 }
 282
 283
 284 ostream &operator <<(ostream &out, const IPaddress &addr) {
 285         const unsigned char *host = reinterpret_cast<const unsigned char *>(&addr.host);
 286         out << int(host[0])
 287                 << '.' << int(host[1])
 288                 << '.' << int(host[2])
 289                 << '.' << int(host[3]);
 290         if (addr.port) {
 291                 out << ':' << SDLNet_Read16(&addr.port);
 292         }
 293         return out;
 294 }
 295
 296
 297 const char *Packet::Type2String(uint8_t t) noexcept {
 298         switch (t) {
 299                 case Ping::TYPE:
 300                         return "Ping";
 301                 case Login::TYPE:
 302                         return "Login";
 303                 case Join::TYPE:
 304                         return "Join";
 305                 case Part::TYPE:
 306                         return "Part";
 307                 case PlayerUpdate::TYPE:
 308                         return "PlayerUpdate";
 309                 default:
 310                         return "Unknown";
 311         }
 312 }
 313
 314 template<class T>
 315 void Packet::Payload::Write(const T &src, size_t off) noexcept {
 316         if ((length - off) < sizeof(T)) {
 317                 // dismiss out of bounds write
 318                 return;
 319         }
 320         *reinterpret_cast<T *>(&data[off]) = src;
 321 }
 322
 323 template<class T>
 324 void Packet::Payload::Read(T &dst, size_t off) const noexcept {
 325         if ((length - off) < sizeof(T)) {
 326                 // dismiss out of bounds read
 327                 return;
 328         }
 329         dst = *reinterpret_cast<T *>(&data[off]);
 330 }
 331
 332 void Packet::Payload::WriteString(const string &src, size_t off, size_t maxlen) noexcept {
 333         uint8_t *dst = &data[off];
 334         size_t len = min(maxlen, length - off);
 335         if (src.size() < len) {
 336                 memset(dst, '\0', len);
 337                 memcpy(dst, src.c_str(), src.size());
 338         } else {
 339                 memcpy(dst, src.c_str(), len);
 340         }
 341 }
 342
 343 void Packet::Payload::ReadString(string &dst, size_t off, size_t maxlen) const noexcept {
 344         size_t len = min(maxlen, length - off);
 345         dst.clear();
 346         dst.reserve(len);
 347         for (size_t i = 0; i < len && data[off + i] != '\0'; ++i) {
 348                 dst.push_back(data[off + i]);
 349         }
 350 }
 351
 352
 353 void Packet::Login::WritePlayerName(const string &name) noexcept {
 354         WriteString(name, 0, 32);
 355 }
 356
 357 void Packet::Login::ReadPlayerName(string &name) const noexcept {
 358         ReadString(name, 0, 32);
 359 }
 360
 361 void Packet::Join::WritePlayer(const Entity &player) noexcept {
 362         Write(player.ID(), 0);
 363         Write(player.ChunkCoords(), 4);
 364         Write(player.Position(), 16);
 365         Write(player.Velocity(), 28);
 366         Write(player.Orientation(), 40);
 367         Write(player.AngularVelocity(), 56);
 368 }
 369
 370 void Packet::Join::ReadPlayerID(uint32_t &id) const noexcept {
 371         Read(id, 0);
 372 }
 373
 374 void Packet::Join::ReadPlayer(Entity &player) const noexcept {
 375         glm::ivec3 chunk_coords(0);
 376         glm::vec3 pos;
 377         glm::vec3 vel;
 378         glm::quat rot;
 379         glm::vec3 ang;
 380
 381         Read(chunk_coords, 4);
 382         Read(pos, 16);
 383         Read(vel, 28);
 384         Read(rot, 40);
 385         Read(ang, 56);
 386
 387         player.Position(chunk_coords, pos);
 388         player.Velocity(vel);
 389         player.Orientation(rot);
 390         player.AngularVelocity(ang);
 391 }
 392
 393 void Packet::Join::WriteWorldName(const string &name) noexcept {
 394         WriteString(name, 68, 32);
 395 }
 396
 397 void Packet::Join::ReadWorldName(string &name) const noexcept {
 398         ReadString(name, 68, 32);
 399 }
 400
 401 void Packet::PlayerUpdate::WritePlayer(const Entity &player) noexcept {
 402         Write(player.ChunkCoords(), 0);
 403         Write(player.Position(), 12);
 404         Write(player.Velocity(), 24);
 405         Write(player.Orientation(), 36);
 406         Write(player.AngularVelocity(), 52);
 407 }
 408
 409 void Packet::PlayerUpdate::ReadPlayer(Entity &player) const noexcept {
 410         glm::ivec3 chunk_coords(0);
 411         glm::vec3 pos;
 412         glm::vec3 vel;
 413         glm::quat rot;
 414         glm::vec3 ang;
 415
 416         Read(chunk_coords, 0);
 417         Read(pos, 12);
 418         Read(vel, 24);
 419         Read(rot, 36);
 420         Read(ang, 52);
 421
 422         player.Position(chunk_coords, pos);
 423         player.Velocity(vel);
 424         player.Orientation(rot);
 425         player.AngularVelocity(ang);
 426 }
 427
 428
 429 void ConnectionHandler::Handle(const UDPpacket &udp_pack) {
 430         const Packet &pack = *reinterpret_cast<const Packet *>(udp_pack.data);
 431         switch (pack.Type()) {
 432                 case Packet::Ping::TYPE:
 433                         On(Packet::As<Packet::Ping>(udp_pack));
 434                         break;
 435                 case Packet::Login::TYPE:
 436                         On(Packet::As<Packet::Login>(udp_pack));
 437                         break;
 438                 case Packet::Join::TYPE:
 439                         On(Packet::As<Packet::Join>(udp_pack));
 440                         break;
 441                 case Packet::Part::TYPE:
 442                         On(Packet::As<Packet::Part>(udp_pack));
 443                         break;
 444                 case Packet::PlayerUpdate::TYPE:
 445                         On(Packet::As<Packet::PlayerUpdate>(udp_pack));
 446                         break;
 447                 default:
 448                         // drop unknown or unhandled packets
 449                         break;
 450         }
 451 }
 452
 453
 454 Server::Server(const Config &conf, World &world)
 455 : serv_sock(nullptr)
 456 , serv_pack{ -1, nullptr, 0 }
 457 , clients()
 458 , world(world) {
 459         serv_sock = SDLNet_UDP_Open(conf.port);
 460         if (!serv_sock) {
 461                 throw NetError("SDLNet_UDP_Open");
 462         }
 463
 464         serv_pack.data = new Uint8[sizeof(Packet)];
 465         serv_pack.maxlen = sizeof(Packet);
 466 }
 467
 468 Server::~Server() {
 469         delete[] serv_pack.data;
 470         SDLNet_UDP_Close(serv_sock);
 471 }
 472
 473
 474 void Server::Handle() {
 475         int result = SDLNet_UDP_Recv(serv_sock, &serv_pack);
 476         while (result > 0) {
 477                 HandlePacket(serv_pack);
 478                 result = SDLNet_UDP_Recv(serv_sock, &serv_pack);
 479         }
 480         if (result == -1) {
 481                 // a boo boo happened
 482                 throw NetError("SDLNet_UDP_Recv");
 483         }
 484 }
 485
 486 void Server::HandlePacket(const UDPpacket &udp_pack) {
 487         if (udp_pack.len < int(sizeof(Packet::Header))) {
 488                 // packet too small, drop
 489                 return;
 490         }
 491         const Packet &pack = *reinterpret_cast<const Packet *>(udp_pack.data);
 492         if (pack.header.tag != Packet::TAG) {
 493                 // mistagged packet, drop
 494                 return;
 495         }
 496
 497         ClientConnection &client = GetClient(udp_pack.address);
 498         client.GetConnection().Received(udp_pack);
 499 }
 500
 501 ClientConnection &Server::GetClient(const IPaddress &addr) {
 502         for (ClientConnection &client : clients) {
 503                 if (client.Matches(addr)) {
 504                         return client;
 505                 }
 506         }
 507         clients.emplace_back(*this, addr);
 508         return clients.back();
 509 }
 510
 511 void Server::Update(int dt) {
 512         for (list<ClientConnection>::iterator client(clients.begin()), end(clients.end()); client != end;) {
 513                 client->Update(dt);
 514                 if (client->Disconnected()) {
 515                         client = clients.erase(client);
 516                 } else {
 517                         ++client;
 518                 }
 519         }
 520 }
 521
 522 }