src/network/connection.h

   1 /*
   2 Minetest
   3 Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
   4
   5 This program is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU Lesser General Public License as published by
   7 the Free Software Foundation; either version 2.1 of the License, or
   8 (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU Lesser General Public License for more details.
  14
  15 You should have received a copy of the GNU Lesser General Public License along
  16 with this program; if not, write to the Free Software Foundation, Inc.,
  17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20 #pragma once
  21
  22 #include "irrlichttypes.h"
  23 #include "peerhandler.h"
  24 #include "socket.h"
  25 #include "constants.h"
  26 #include "util/pointer.h"
  27 #include "util/container.h"
  28 #include "util/thread.h"
  29 #include "util/numeric.h"
  30 #include "networkprotocol.h"
  31 #include <iostream>
  32 #include <vector>
  33 #include <map>
  34
  35 class NetworkPacket;
  36
  37 namespace con
  38 {
  39
  40 class ConnectionReceiveThread;
  41 class ConnectionSendThread;
  42
  43 typedef enum MTProtocols {
  44         MTP_PRIMARY,
  45         MTP_UDP,
  46         MTP_MINETEST_RELIABLE_UDP
  47 } MTProtocols;
  48
  49 #define MAX_UDP_PEERS 65535
  50
  51 #define SEQNUM_MAX 65535
  52
  53 inline bool seqnum_higher(u16 totest, u16 base)
  54 {
  55         if (totest > base)
  56         {
  57                 if ((totest - base) > (SEQNUM_MAX/2))
  58                         return false;
  59
  60                 return true;
  61         }
  62
  63         if ((base - totest) > (SEQNUM_MAX/2))
  64                 return true;
  65
  66         return false;
  67 }
  68
  69 inline bool seqnum_in_window(u16 seqnum, u16 next,u16 window_size)
  70 {
  71         u16 window_start = next;
  72         u16 window_end   = ( next + window_size ) % (SEQNUM_MAX+1);
  73
  74         if (window_start < window_end) {
  75                 return ((seqnum >= window_start) && (seqnum < window_end));
  76         }
  77
  78
  79         return ((seqnum < window_end) || (seqnum >= window_start));
  80 }
  81
  82 static inline float CALC_DTIME(u64 lasttime, u64 curtime)
  83 {
  84         float value = ( curtime - lasttime) / 1000.0;
  85         return MYMAX(MYMIN(value,0.1),0.0);
  86 }
  87
  88 struct BufferedPacket
  89 {
  90         BufferedPacket(u8 *a_data, u32 a_size):
  91                 data(a_data, a_size)
  92         {}
  93         BufferedPacket(u32 a_size):
  94                 data(a_size)
  95         {}
  96         Buffer<u8> data; // Data of the packet, including headers
  97         float time = 0.0f; // Seconds from buffering the packet or re-sending
  98         float totaltime = 0.0f; // Seconds from buffering the packet
  99         u64 absolute_send_time = -1;
 100         Address address; // Sender or destination
 101         unsigned int resend_count = 0;
 102 };
 103
 104 // This adds the base headers to the data and makes a packet out of it
 105 BufferedPacket makePacket(Address &address, const SharedBuffer<u8> &data,
 106                 u32 protocol_id, session_t sender_peer_id, u8 channel);
 107
 108 // Depending on size, make a TYPE_ORIGINAL or TYPE_SPLIT packet
 109 // Increments split_seqnum if a split packet is made
 110 void makeAutoSplitPacket(const SharedBuffer<u8> &data, u32 chunksize_max,
 111                 u16 &split_seqnum, std::list<SharedBuffer<u8>> *list);
 112
 113 // Add the TYPE_RELIABLE header to the data
 114 SharedBuffer<u8> makeReliablePacket(const SharedBuffer<u8> &data, u16 seqnum);
 115
 116 struct IncomingSplitPacket
 117 {
 118         IncomingSplitPacket(u32 cc, bool r):
 119                 chunk_count(cc), reliable(r) {}
 120
 121         IncomingSplitPacket() = delete;
 122
 123         float time = 0.0f; // Seconds from adding
 124         u32 chunk_count;
 125         bool reliable; // If true, isn't deleted on timeout
 126
 127         bool allReceived() const
 128         {
 129                 return (chunks.size() == chunk_count);
 130         }
 131         bool insert(u32 chunk_num, SharedBuffer<u8> &chunkdata);
 132         SharedBuffer<u8> reassemble();
 133
 134 private:
 135         // Key is chunk number, value is data without headers
 136         std::map<u16, SharedBuffer<u8>> chunks;
 137 };
 138
 139 /*
 140 === NOTES ===
 141
 142 A packet is sent through a channel to a peer with a basic header:
 143         Header (7 bytes):
 144         [0] u32 protocol_id
 145         [4] session_t sender_peer_id
 146         [6] u8 channel
 147 sender_peer_id:
 148         Unique to each peer.
 149         value 0 (PEER_ID_INEXISTENT) is reserved for making new connections
 150         value 1 (PEER_ID_SERVER) is reserved for server
 151         these constants are defined in constants.h
 152 channel:
 153         Channel numbers have no intrinsic meaning. Currently only 0, 1, 2 exist.
 154 */
 155 #define BASE_HEADER_SIZE 7
 156 #define CHANNEL_COUNT 3
 157 /*
 158 Packet types:
 159
 160 CONTROL: This is a packet used by the protocol.
 161 - When this is processed, nothing is handed to the user.
 162         Header (2 byte):
 163         [0] u8 type
 164         [1] u8 controltype
 165 controltype and data description:
 166         CONTROLTYPE_ACK
 167                 [2] u16 seqnum
 168         CONTROLTYPE_SET_PEER_ID
 169                 [2] session_t peer_id_new
 170         CONTROLTYPE_PING
 171         - There is no actual reply, but this can be sent in a reliable
 172           packet to get a reply
 173         CONTROLTYPE_DISCO
 174 */
 175 //#define TYPE_CONTROL 0
 176 #define CONTROLTYPE_ACK 0
 177 #define CONTROLTYPE_SET_PEER_ID 1
 178 #define CONTROLTYPE_PING 2
 179 #define CONTROLTYPE_DISCO 3
 180
 181 /*
 182 ORIGINAL: This is a plain packet with no control and no error
 183 checking at all.
 184 - When this is processed, it is directly handed to the user.
 185         Header (1 byte):
 186         [0] u8 type
 187 */
 188 //#define TYPE_ORIGINAL 1
 189 #define ORIGINAL_HEADER_SIZE 1
 190 /*
 191 SPLIT: These are sequences of packets forming one bigger piece of
 192 data.
 193 - When processed and all the packet_nums 0...packet_count-1 are
 194   present (this should be buffered), the resulting data shall be
 195   directly handed to the user.
 196 - If the data fails to come up in a reasonable time, the buffer shall
 197   be silently discarded.
 198 - These can be sent as-is or atop of a RELIABLE packet stream.
 199         Header (7 bytes):
 200         [0] u8 type
 201         [1] u16 seqnum
 202         [3] u16 chunk_count
 203         [5] u16 chunk_num
 204 */
 205 //#define TYPE_SPLIT 2
 206 /*
 207 RELIABLE: Delivery of all RELIABLE packets shall be forced by ACKs,
 208 and they shall be delivered in the same order as sent. This is done
 209 with a buffer in the receiving and transmitting end.
 210 - When this is processed, the contents of each packet is recursively
 211   processed as packets.
 212         Header (3 bytes):
 213         [0] u8 type
 214         [1] u16 seqnum
 215
 216 */
 217 //#define TYPE_RELIABLE 3
 218 #define RELIABLE_HEADER_SIZE 3
 219 #define SEQNUM_INITIAL 65500
 220
 221 enum PacketType: u8 {
 222         PACKET_TYPE_CONTROL = 0,
 223         PACKET_TYPE_ORIGINAL = 1,
 224         PACKET_TYPE_SPLIT = 2,
 225         PACKET_TYPE_RELIABLE = 3,
 226         PACKET_TYPE_MAX
 227 };
 228 /*
 229         A buffer which stores reliable packets and sorts them internally
 230         for fast access to the smallest one.
 231 */
 232
 233 typedef std::list<BufferedPacket>::iterator RPBSearchResult;
 234
 235 class ReliablePacketBuffer
 236 {
 237 public:
 238         ReliablePacketBuffer() = default;
 239
 240         bool getFirstSeqnum(u16& result);
 241
 242         BufferedPacket popFirst();
 243         BufferedPacket popSeqnum(u16 seqnum);
 244         void insert(const BufferedPacket &p, u16 next_expected);
 245
 246         void incrementTimeouts(float dtime);
 247         std::list<BufferedPacket> getTimedOuts(float timeout, u32 max_packets);
 248
 249         void print();
 250         bool empty();
 251         u32 size();
 252
 253
 254 private:
 255         RPBSearchResult findPacket(u16 seqnum); // does not perform locking
 256         inline RPBSearchResult notFound() { return m_list.end(); }
 257
 258         std::list<BufferedPacket> m_list;
 259
 260         u16 m_oldest_non_answered_ack;
 261
 262         std::mutex m_list_mutex;
 263 };
 264
 265 /*
 266         A buffer for reconstructing split packets
 267 */
 268
 269 class IncomingSplitBuffer
 270 {
 271 public:
 272         ~IncomingSplitBuffer();
 273         /*
 274                 Returns a reference counted buffer of length != 0 when a full split
 275                 packet is constructed. If not, returns one of length 0.
 276         */
 277         SharedBuffer<u8> insert(const BufferedPacket &p, bool reliable);
 278
 279         void removeUnreliableTimedOuts(float dtime, float timeout);
 280
 281 private:
 282         // Key is seqnum
 283         std::map<u16, IncomingSplitPacket*> m_buf;
 284
 285         std::mutex m_map_mutex;
 286 };
 287
 288 struct OutgoingPacket
 289 {
 290         session_t peer_id;
 291         u8 channelnum;
 292         SharedBuffer<u8> data;
 293         bool reliable;
 294         bool ack;
 295
 296         OutgoingPacket(session_t peer_id_, u8 channelnum_, const SharedBuffer<u8> &data_,
 297                         bool reliable_,bool ack_=false):
 298                 peer_id(peer_id_),
 299                 channelnum(channelnum_),
 300                 data(data_),
 301                 reliable(reliable_),
 302                 ack(ack_)
 303         {
 304         }
 305 };
 306
 307 enum ConnectionCommandType{
 308         CONNCMD_NONE,
 309         CONNCMD_SERVE,
 310         CONNCMD_CONNECT,
 311         CONNCMD_DISCONNECT,
 312         CONNCMD_DISCONNECT_PEER,
 313         CONNCMD_SEND,
 314         CONNCMD_SEND_TO_ALL,
 315         CONCMD_ACK,
 316         CONCMD_CREATE_PEER
 317 };
 318
 319 struct ConnectionCommand
 320 {
 321         enum ConnectionCommandType type = CONNCMD_NONE;
 322         Address address;
 323         session_t peer_id = PEER_ID_INEXISTENT;
 324         u8 channelnum = 0;
 325         Buffer<u8> data;
 326         bool reliable = false;
 327         bool raw = false;
 328
 329         ConnectionCommand() = default;
 330
 331         void serve(Address address_)
 332         {
 333                 type = CONNCMD_SERVE;
 334                 address = address_;
 335         }
 336         void connect(Address address_)
 337         {
 338                 type = CONNCMD_CONNECT;
 339                 address = address_;
 340         }
 341         void disconnect()
 342         {
 343                 type = CONNCMD_DISCONNECT;
 344         }
 345         void disconnect_peer(session_t peer_id_)
 346         {
 347                 type = CONNCMD_DISCONNECT_PEER;
 348                 peer_id = peer_id_;
 349         }
 350
 351         void send(session_t peer_id_, u8 channelnum_, NetworkPacket *pkt, bool reliable_);
 352
 353         void ack(session_t peer_id_, u8 channelnum_, const Buffer<u8> &data_)
 354         {
 355                 type = CONCMD_ACK;
 356                 peer_id = peer_id_;
 357                 channelnum = channelnum_;
 358                 data = data_;
 359                 reliable = false;
 360         }
 361
 362         void createPeer(session_t peer_id_, const Buffer<u8> &data_)
 363         {
 364                 type = CONCMD_CREATE_PEER;
 365                 peer_id = peer_id_;
 366                 data = data_;
 367                 channelnum = 0;
 368                 reliable = true;
 369                 raw = true;
 370         }
 371 };
 372
 373 /* maximum window size to use, 0xFFFF is theoretical maximum. don't think about
 374  * touching it, the less you're away from it the more likely data corruption
 375  * will occur
 376  */
 377 #define MAX_RELIABLE_WINDOW_SIZE 0x8000
 378 /* starting value for window size */
 379 #define START_RELIABLE_WINDOW_SIZE 0x400
 380 /* minimum value for window size */
 381 #define MIN_RELIABLE_WINDOW_SIZE 0x40
 382
 383 class Channel
 384 {
 385
 386 public:
 387         u16 readNextIncomingSeqNum();
 388         u16 incNextIncomingSeqNum();
 389
 390         u16 getOutgoingSequenceNumber(bool& successfull);
 391         u16 readOutgoingSequenceNumber();
 392         bool putBackSequenceNumber(u16);
 393
 394         u16 readNextSplitSeqNum();
 395         void setNextSplitSeqNum(u16 seqnum);
 396
 397         // This is for buffering the incoming packets that are coming in
 398         // the wrong order
 399         ReliablePacketBuffer incoming_reliables;
 400         // This is for buffering the sent packets so that the sender can
 401         // re-send them if no ACK is received
 402         ReliablePacketBuffer outgoing_reliables_sent;
 403
 404         //queued reliable packets
 405         std::queue<BufferedPacket> queued_reliables;
 406
 407         //queue commands prior splitting to packets
 408         std::deque<ConnectionCommand> queued_commands;
 409
 410         IncomingSplitBuffer incoming_splits;
 411
 412         Channel() = default;
 413         ~Channel() = default;
 414
 415         void UpdatePacketLossCounter(unsigned int count);
 416         void UpdatePacketTooLateCounter();
 417         void UpdateBytesSent(unsigned int bytes,unsigned int packages=1);
 418         void UpdateBytesLost(unsigned int bytes);
 419         void UpdateBytesReceived(unsigned int bytes);
 420
 421         void UpdateTimers(float dtime);
 422
 423         const float getCurrentDownloadRateKB()
 424                 { MutexAutoLock lock(m_internal_mutex); return cur_kbps; };
 425         const float getMaxDownloadRateKB()
 426                 { MutexAutoLock lock(m_internal_mutex); return max_kbps; };
 427
 428         const float getCurrentLossRateKB()
 429                 { MutexAutoLock lock(m_internal_mutex); return cur_kbps_lost; };
 430         const float getMaxLossRateKB()
 431                 { MutexAutoLock lock(m_internal_mutex); return max_kbps_lost; };
 432
 433         const float getCurrentIncomingRateKB()
 434                 { MutexAutoLock lock(m_internal_mutex); return cur_incoming_kbps; };
 435         const float getMaxIncomingRateKB()
 436                 { MutexAutoLock lock(m_internal_mutex); return max_incoming_kbps; };
 437
 438         const float getAvgDownloadRateKB()
 439                 { MutexAutoLock lock(m_internal_mutex); return avg_kbps; };
 440         const float getAvgLossRateKB()
 441                 { MutexAutoLock lock(m_internal_mutex); return avg_kbps_lost; };
 442         const float getAvgIncomingRateKB()
 443                 { MutexAutoLock lock(m_internal_mutex); return avg_incoming_kbps; };
 444
 445         const unsigned int getWindowSize() const { return window_size; };
 446
 447         void setWindowSize(unsigned int size) { window_size = size; };
 448 private:
 449         std::mutex m_internal_mutex;
 450         int window_size = MIN_RELIABLE_WINDOW_SIZE;
 451
 452         u16 next_incoming_seqnum = SEQNUM_INITIAL;
 453
 454         u16 next_outgoing_seqnum = SEQNUM_INITIAL;
 455         u16 next_outgoing_split_seqnum = SEQNUM_INITIAL;
 456
 457         unsigned int current_packet_loss = 0;
 458         unsigned int current_packet_too_late = 0;
 459         unsigned int current_packet_successful = 0;
 460         float packet_loss_counter = 0.0f;
 461
 462         unsigned int current_bytes_transfered = 0;
 463         unsigned int current_bytes_received = 0;
 464         unsigned int current_bytes_lost = 0;
 465         float max_kbps = 0.0f;
 466         float cur_kbps = 0.0f;
 467         float avg_kbps = 0.0f;
 468         float max_incoming_kbps = 0.0f;
 469         float cur_incoming_kbps = 0.0f;
 470         float avg_incoming_kbps = 0.0f;
 471         float max_kbps_lost = 0.0f;
 472         float cur_kbps_lost = 0.0f;
 473         float avg_kbps_lost = 0.0f;
 474         float bpm_counter = 0.0f;
 475
 476         unsigned int rate_samples = 0;
 477 };
 478
 479 class Peer;
 480
 481 class PeerHelper
 482 {
 483 public:
 484         PeerHelper() = default;
 485         PeerHelper(Peer* peer);
 486         ~PeerHelper();
 487
 488         PeerHelper&   operator=(Peer* peer);
 489         Peer*         operator->() const;
 490         bool          operator!();
 491         Peer*         operator&() const;
 492         bool          operator!=(void* ptr);
 493
 494 private:
 495         Peer *m_peer = nullptr;
 496 };
 497
 498 class Connection;
 499
 500 typedef enum {
 501         CUR_DL_RATE,
 502         AVG_DL_RATE,
 503         CUR_INC_RATE,
 504         AVG_INC_RATE,
 505         CUR_LOSS_RATE,
 506         AVG_LOSS_RATE,
 507 } rate_stat_type;
 508
 509 class Peer {
 510         public:
 511                 friend class PeerHelper;
 512
 513                 Peer(Address address_,u16 id_,Connection* connection) :
 514                         id(id_),
 515                         m_connection(connection),
 516                         address(address_),
 517                         m_last_timeout_check(porting::getTimeMs())
 518                 {
 519                 };
 520
 521                 virtual ~Peer() {
 522                         MutexAutoLock usage_lock(m_exclusive_access_mutex);
 523                         FATAL_ERROR_IF(m_usage != 0, "Reference counting failure");
 524                 };
 525
 526                 // Unique id of the peer
 527                 u16 id;
 528
 529                 void Drop();
 530
 531                 virtual void PutReliableSendCommand(ConnectionCommand &c,
 532                                                 unsigned int max_packet_size) {};
 533
 534                 virtual bool getAddress(MTProtocols type, Address& toset) = 0;
 535
 536                 bool isPendingDeletion()
 537                 { MutexAutoLock lock(m_exclusive_access_mutex); return m_pending_deletion; };
 538
 539                 void ResetTimeout()
 540                         {MutexAutoLock lock(m_exclusive_access_mutex); m_timeout_counter = 0.0; };
 541
 542                 bool isTimedOut(float timeout);
 543
 544                 unsigned int m_increment_packets_remaining = 0;
 545
 546                 virtual u16 getNextSplitSequenceNumber(u8 channel) { return 0; };
 547                 virtual void setNextSplitSequenceNumber(u8 channel, u16 seqnum) {};
 548                 virtual SharedBuffer<u8> addSplitPacket(u8 channel, const BufferedPacket &toadd,
 549                                 bool reliable)
 550                 {
 551                         errorstream << "Peer::addSplitPacket called,"
 552                                         << " this is supposed to be never called!" << std::endl;
 553                         return SharedBuffer<u8>(0);
 554                 };
 555
 556                 virtual bool Ping(float dtime, SharedBuffer<u8>& data) { return false; };
 557
 558                 virtual float getStat(rtt_stat_type type) const {
 559                         switch (type) {
 560                                 case MIN_RTT:
 561                                         return m_rtt.min_rtt;
 562                                 case MAX_RTT:
 563                                         return m_rtt.max_rtt;
 564                                 case AVG_RTT:
 565                                         return m_rtt.avg_rtt;
 566                                 case MIN_JITTER:
 567                                         return m_rtt.jitter_min;
 568                                 case MAX_JITTER:
 569                                         return m_rtt.jitter_max;
 570                                 case AVG_JITTER:
 571                                         return m_rtt.jitter_avg;
 572                         }
 573                         return -1;
 574                 }
 575         protected:
 576                 virtual void reportRTT(float rtt) {};
 577
 578                 void RTTStatistics(float rtt,
 579                                                         const std::string &profiler_id = "",
 580                                                         unsigned int num_samples = 1000);
 581
 582                 bool IncUseCount();
 583                 void DecUseCount();
 584
 585                 std::mutex m_exclusive_access_mutex;
 586
 587                 bool m_pending_deletion = false;
 588
 589                 Connection* m_connection;
 590
 591                 // Address of the peer
 592                 Address address;
 593
 594                 // Ping timer
 595                 float m_ping_timer = 0.0f;
 596         private:
 597
 598                 struct rttstats {
 599                         float jitter_min = FLT_MAX;
 600                         float jitter_max = 0.0f;
 601                         float jitter_avg = -1.0f;
 602                         float min_rtt = FLT_MAX;
 603                         float max_rtt = 0.0f;
 604                         float avg_rtt = -1.0f;
 605
 606                         rttstats() = default;
 607                 };
 608
 609                 rttstats m_rtt;
 610                 float m_last_rtt = -1.0f;
 611
 612                 // current usage count
 613                 unsigned int m_usage = 0;
 614
 615                 // Seconds from last receive
 616                 float m_timeout_counter = 0.0f;
 617
 618                 u64 m_last_timeout_check;
 619 };
 620
 621 class UDPPeer : public Peer
 622 {
 623 public:
 624
 625         friend class PeerHelper;
 626         friend class ConnectionReceiveThread;
 627         friend class ConnectionSendThread;
 628         friend class Connection;
 629
 630         UDPPeer(u16 a_id, Address a_address, Connection* connection);
 631         virtual ~UDPPeer() = default;
 632
 633         void PutReliableSendCommand(ConnectionCommand &c,
 634                                                         unsigned int max_packet_size);
 635
 636         bool getAddress(MTProtocols type, Address& toset);
 637
 638         u16 getNextSplitSequenceNumber(u8 channel);
 639         void setNextSplitSequenceNumber(u8 channel, u16 seqnum);
 640
 641         SharedBuffer<u8> addSplitPacket(u8 channel, const BufferedPacket &toadd,
 642                 bool reliable);
 643
 644 protected:
 645         /*
 646                 Calculates avg_rtt and resend_timeout.
 647                 rtt=-1 only recalculates resend_timeout
 648         */
 649         void reportRTT(float rtt);
 650
 651         void RunCommandQueues(
 652                                         unsigned int max_packet_size,
 653                                         unsigned int maxcommands,
 654                                         unsigned int maxtransfer);
 655
 656         float getResendTimeout()
 657                 { MutexAutoLock lock(m_exclusive_access_mutex); return resend_timeout; }
 658
 659         void setResendTimeout(float timeout)
 660                 { MutexAutoLock lock(m_exclusive_access_mutex); resend_timeout = timeout; }
 661         bool Ping(float dtime,SharedBuffer<u8>& data);
 662
 663         Channel channels[CHANNEL_COUNT];
 664         bool m_pending_disconnect = false;
 665 private:
 666         // This is changed dynamically
 667         float resend_timeout = 0.5;
 668
 669         bool processReliableSendCommand(
 670                                         ConnectionCommand &c,
 671                                         unsigned int max_packet_size);
 672 };
 673
 674 /*
 675         Connection
 676 */
 677
 678 enum ConnectionEventType{
 679         CONNEVENT_NONE,
 680         CONNEVENT_DATA_RECEIVED,
 681         CONNEVENT_PEER_ADDED,
 682         CONNEVENT_PEER_REMOVED,
 683         CONNEVENT_BIND_FAILED,
 684 };
 685
 686 struct ConnectionEvent
 687 {
 688         enum ConnectionEventType type = CONNEVENT_NONE;
 689         session_t peer_id = 0;
 690         Buffer<u8> data;
 691         bool timeout = false;
 692         Address address;
 693
 694         ConnectionEvent() = default;
 695
 696         const char *describe() const
 697         {
 698                 switch(type) {
 699                 case CONNEVENT_NONE:
 700                         return "CONNEVENT_NONE";
 701                 case CONNEVENT_DATA_RECEIVED:
 702                         return "CONNEVENT_DATA_RECEIVED";
 703                 case CONNEVENT_PEER_ADDED:
 704                         return "CONNEVENT_PEER_ADDED";
 705                 case CONNEVENT_PEER_REMOVED:
 706                         return "CONNEVENT_PEER_REMOVED";
 707                 case CONNEVENT_BIND_FAILED:
 708                         return "CONNEVENT_BIND_FAILED";
 709                 }
 710                 return "Invalid ConnectionEvent";
 711         }
 712
 713         void dataReceived(session_t peer_id_, const Buffer<u8> &data_)
 714         {
 715                 type = CONNEVENT_DATA_RECEIVED;
 716                 peer_id = peer_id_;
 717                 data = data_;
 718         }
 719         void peerAdded(session_t peer_id_, Address address_)
 720         {
 721                 type = CONNEVENT_PEER_ADDED;
 722                 peer_id = peer_id_;
 723                 address = address_;
 724         }
 725         void peerRemoved(session_t peer_id_, bool timeout_, Address address_)
 726         {
 727                 type = CONNEVENT_PEER_REMOVED;
 728                 peer_id = peer_id_;
 729                 timeout = timeout_;
 730                 address = address_;
 731         }
 732         void bindFailed()
 733         {
 734                 type = CONNEVENT_BIND_FAILED;
 735         }
 736 };
 737
 738 class PeerHandler;
 739
 740 class Connection
 741 {
 742 public:
 743         friend class ConnectionSendThread;
 744         friend class ConnectionReceiveThread;
 745
 746         Connection(u32 protocol_id, u32 max_packet_size, float timeout, bool ipv6,
 747                         PeerHandler *peerhandler);
 748         ~Connection();
 749
 750         /* Interface */
 751         ConnectionEvent waitEvent(u32 timeout_ms);
 752         // Warning: creates an unnecessary copy, prefer putCommand(T&&) if possible
 753         void putCommand(const ConnectionCommand &c);
 754         void putCommand(ConnectionCommand &&c);
 755
 756         void SetTimeoutMs(u32 timeout) { m_bc_receive_timeout = timeout; }
 757         void Serve(Address bind_addr);
 758         void Connect(Address address);
 759         bool Connected();
 760         void Disconnect();
 761         void Receive(NetworkPacket* pkt);
 762         bool TryReceive(NetworkPacket *pkt);
 763         void Send(session_t peer_id, u8 channelnum, NetworkPacket *pkt, bool reliable);
 764         session_t GetPeerID() const { return m_peer_id; }
 765         Address GetPeerAddress(session_t peer_id);
 766         float getPeerStat(session_t peer_id, rtt_stat_type type);
 767         float getLocalStat(rate_stat_type type);
 768         const u32 GetProtocolID() const { return m_protocol_id; };
 769         const std::string getDesc();
 770         void DisconnectPeer(session_t peer_id);
 771
 772 protected:
 773         PeerHelper getPeerNoEx(session_t peer_id);
 774         u16   lookupPeer(Address& sender);
 775
 776         u16 createPeer(Address& sender, MTProtocols protocol, int fd);
 777         UDPPeer*  createServerPeer(Address& sender);
 778         bool deletePeer(session_t peer_id, bool timeout);
 779
 780         void SetPeerID(session_t id) { m_peer_id = id; }
 781
 782         void sendAck(session_t peer_id, u8 channelnum, u16 seqnum);
 783
 784         void PrintInfo(std::ostream &out);
 785
 786         std::vector<session_t> getPeerIDs()
 787         {
 788                 MutexAutoLock peerlock(m_peers_mutex);
 789                 return m_peer_ids;
 790         }
 791
 792         UDPSocket m_udpSocket;
 793         // Command queue: user -> SendThread
 794         MutexedQueue<ConnectionCommand> m_command_queue;
 795
 796         bool Receive(NetworkPacket *pkt, u32 timeout);
 797
 798         // Warning: creates an unnecessary copy, prefer putEvent(T&&) if possible
 799         void putEvent(const ConnectionEvent &e);
 800         void putEvent(ConnectionEvent &&e);
 801
 802         void TriggerSend();
 803
 804         bool ConnectedToServer()
 805         {
 806                 return getPeerNoEx(PEER_ID_SERVER) != nullptr;
 807         }
 808 private:
 809         // Event queue: ReceiveThread -> user
 810         MutexedQueue<ConnectionEvent> m_event_queue;
 811
 812         session_t m_peer_id = 0;
 813         u32 m_protocol_id;
 814
 815         std::map<session_t, Peer *> m_peers;
 816         std::vector<session_t> m_peer_ids;
 817         std::mutex m_peers_mutex;
 818
 819         std::unique_ptr<ConnectionSendThread> m_sendThread;
 820         std::unique_ptr<ConnectionReceiveThread> m_receiveThread;
 821
 822         std::mutex m_info_mutex;
 823
 824         // Backwards compatibility
 825         PeerHandler *m_bc_peerhandler;
 826         u32 m_bc_receive_timeout = 0;
 827
 828         bool m_shutting_down = false;
 829
 830         session_t m_next_remote_peer_id = 2;
 831 };
 832
 833 } // namespace