1 /*
2 Minetest
3 Copyright (C) 2010-2014 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 "irr_v3d.h"                   // for irrlicht datatypes
23 
24 #include "constants.h"
25 #include "serialization.h"             // for SER_FMT_VER_INVALID
26 #include "network/networkpacket.h"
27 #include "network/networkprotocol.h"
28 #include "network/address.h"
29 #include "porting.h"
30 
31 #include <list>
32 #include <vector>
33 #include <set>
34 #include <mutex>
35 
36 class MapBlock;
37 class ServerEnvironment;
38 class EmergeManager;
39 
40 /*
41  * State Transitions
42 
43       Start
44   (peer connect)
45         |
46         v
47       /-----------------\
48       |                 |
49       |    Created      |
50       |                 |
51       \-----------------/
52                |                  depending of the incoming packet
53                ----------------------------------------
54                                                       v
55                                        +-----------------------------+
56                                        |IN:                          |
57                                        | TOSERVER_INIT               |
58                                        +-----------------------------+
59                                                       | invalid playername
60                                                       | or denied by mod
61                                                       v
62                                        +-----------------------------+
63                                        |OUT:                         |
64                                        | TOCLIENT_HELLO              |
65                                        +-----------------------------+
66                                                       |
67                                                       |
68                                                       v
69       /-----------------\                    /-----------------\
70       |                 |                    |                 |
71       |  AwaitingInit2  |<---------          |    HelloSent    |
72       |                 |         |          |                 |
73       \-----------------/         |          \-----------------/
74                |                  |                   |
75 +-----------------------------+   |    *-----------------------------*     Auth fails
76 |IN:                          |   |    |Authentication, depending on |------------------
77 | TOSERVER_INIT2              |   |    | packet sent by client       |                 |
78 +-----------------------------+   |    *-----------------------------*                 |
79                |                  |                   |                                |
80                |                  |                   | Authentication                 |
81                v                  |                   |  successful                    |
82       /-----------------\         |                   v                                |
83       |                 |         |    +-----------------------------+                 |
84       |    InitDone     |         |    |OUT:                         |                 |
85       |                 |         |    | TOCLIENT_AUTH_ACCEPT        |                 |
86       \-----------------/         |    +-----------------------------+                 |
87                |                  |                   |                                |
88 +-----------------------------+   ---------------------                                |
89 |OUT:                         |                                                        |
90 | TOCLIENT_MOVEMENT           |                                                        |
91 | TOCLIENT_ITEMDEF            |                                                        |
92 | TOCLIENT_NODEDEF            |                                                        |
93 | TOCLIENT_ANNOUNCE_MEDIA     |                                                        |
94 | TOCLIENT_DETACHED_INVENTORY |                                                        |
95 | TOCLIENT_TIME_OF_DAY        |                                                        |
96 +-----------------------------+                                                        |
97                |                                                                       |
98                |                                                                       |
99                |      -----------------------------                                    |
100                v      |                           |                                    |
101       /-----------------\                         v                                    |
102       |                 |             +-----------------------------+                  |
103       | DefinitionsSent |             |IN:                          |                  |
104       |                 |             | TOSERVER_REQUEST_MEDIA      |                  |
105       \-----------------/             |                             |                  |
106                |                      +-----------------------------+                  |
107                |      ^                           |                                    |
108                |      -----------------------------                                    |
109                v                                                                       v
110 +-----------------------------+                        --------------------------------+
111 |IN:                          |                        |                               ^
112 | TOSERVER_CLIENT_READY       |                        v                               |
113 +-----------------------------+            +------------------------+                  |
114                |                           |OUT:                    |                  |
115                v                           | TOCLIENT_ACCESS_DENIED |                  |
116 +-----------------------------+            +------------------------+                  |
117 |OUT:                         |                        |                               |
118 | TOCLIENT_MOVE_PLAYER        |                        v                               |
119 | TOCLIENT_PRIVILEGES         |                /-----------------\                     |
120 | TOCLIENT_INVENTORY_FORMSPEC |                |                 |                     |
121 | UpdateCrafting              |                |     Denied      |                     |
122 | TOCLIENT_INVENTORY          |                |                 |                     |
123 | TOCLIENT_HP (opt)           |                \-----------------/                     |
124 | TOCLIENT_BREATH             |                                                        |
125 | TOCLIENT_DEATHSCREEN        |                                                        |
126 +-----------------------------+                                                        |
127               |                                                                        |
128               v                                                                        |
129       /-----------------\      async mod action (ban, kick)                            |
130       |                 |---------------------------------------------------------------
131  ---->|     Active      |
132  |    |                 |----------------------------------------------
133  |    \-----------------/      timeout                                v
134  |       |           |                                  +-----------------------------+
135  |       |           |                                  |OUT:                         |
136  |       |           |                                  | TOCLIENT_DISCONNECT         |
137  |       |           |                                  +-----------------------------+
138  |       |           |                                                |
139  |       |           v                                                v
140  |       |  +-----------------------------+                    /-----------------\
141  |       |  |IN:                          |                    |                 |
142  |       |  | TOSERVER_DISCONNECT         |------------------->|  Disconnecting  |
143  |       |  +-----------------------------+                    |                 |
144  |       |                                                     \-----------------/
145  |       | any auth packet which was
146  |       | allowed in TOCLIENT_AUTH_ACCEPT
147  |       v
148  |    *-----------------------------* Auth      +-------------------------------+
149  |    |Authentication, depending on | succeeds  |OUT:                           |
150  |    | packet sent by client       |---------->| TOCLIENT_ACCEPT_SUDO_MODE     |
151  |    *-----------------------------*           +-------------------------------+
152  |                  |                                            |
153  |                  | Auth fails                        /-----------------\
154  |                  v                                   |                 |
155  |    +-------------------------------+                 |    SudoMode     |
156  |    |OUT:                           |                 |                 |
157  |    | TOCLIENT_DENY_SUDO_MODE       |                 \-----------------/
158  |    +-------------------------------+                          |
159  |                  |                                            v
160  |                  |                               +-----------------------------+
161  |                  |    sets password accordingly  |IN:                          |
162  -------------------+-------------------------------| TOSERVER_FIRST_SRP          |
163                                                     +-----------------------------+
164 
165 */
166 namespace con {
167 	class Connection;
168 }
169 
170 
171 // Also make sure to update the ClientInterface::statenames
172 // array when modifying these enums
173 
174 enum ClientState
175 {
176 	CS_Invalid,
177 	CS_Disconnecting,
178 	CS_Denied,
179 	CS_Created,
180 	CS_AwaitingInit2,
181 	CS_HelloSent,
182 	CS_InitDone,
183 	CS_DefinitionsSent,
184 	CS_Active,
185 	CS_SudoMode
186 };
187 
188 enum ClientStateEvent
189 {
190 	CSE_Hello,
191 	CSE_AuthAccept,
192 	CSE_GotInit2,
193 	CSE_SetDenied,
194 	CSE_SetDefinitionsSent,
195 	CSE_SetClientReady,
196 	CSE_SudoSuccess,
197 	CSE_SudoLeave,
198 	CSE_Disconnect
199 };
200 
201 /*
202 	Used for queueing and sorting block transfers in containers
203 
204 	Lower priority number means higher priority.
205 */
206 struct PrioritySortedBlockTransfer
207 {
PrioritySortedBlockTransferPrioritySortedBlockTransfer208 	PrioritySortedBlockTransfer(float a_priority, const v3s16 &a_pos, session_t a_peer_id)
209 	{
210 		priority = a_priority;
211 		pos = a_pos;
212 		peer_id = a_peer_id;
213 	}
214 	bool operator < (const PrioritySortedBlockTransfer &other) const
215 	{
216 		return priority < other.priority;
217 	}
218 	float priority;
219 	v3s16 pos;
220 	session_t peer_id;
221 };
222 
223 class RemoteClient
224 {
225 public:
226 	// peer_id=0 means this client has no associated peer
227 	// NOTE: If client is made allowed to exist while peer doesn't,
228 	//       this has to be set to 0 when there is no peer.
229 	//       Also, the client must be moved to some other container.
230 	session_t peer_id = PEER_ID_INEXISTENT;
231 	// The serialization version to use with the client
232 	u8 serialization_version = SER_FMT_VER_INVALID;
233 	//
234 	u16 net_proto_version = 0;
235 
236 	/* Authentication information */
237 	std::string enc_pwd = "";
238 	bool create_player_on_auth_success = false;
239 	AuthMechanism chosen_mech  = AUTH_MECHANISM_NONE;
240 	void *auth_data = nullptr;
241 	u32 allowed_auth_mechs = 0;
242 	u32 allowed_sudo_mechs = 0;
243 
isSudoMechAllowed(AuthMechanism mech)244 	bool isSudoMechAllowed(AuthMechanism mech)
245 	{ return allowed_sudo_mechs & mech; }
isMechAllowed(AuthMechanism mech)246 	bool isMechAllowed(AuthMechanism mech)
247 	{ return allowed_auth_mechs & mech; }
248 
249 	RemoteClient();
250 	~RemoteClient() = default;
251 
252 	/*
253 		Finds block that should be sent next to the client.
254 		Environment should be locked when this is called.
255 		dtime is used for resetting send radius at slow interval
256 	*/
257 	void GetNextBlocks(ServerEnvironment *env, EmergeManager* emerge,
258 			float dtime, std::vector<PrioritySortedBlockTransfer> &dest);
259 
260 	void GotBlock(v3s16 p);
261 
262 	void SentBlock(v3s16 p);
263 
264 	void SetBlockNotSent(v3s16 p);
265 	void SetBlocksNotSent(std::map<v3s16, MapBlock*> &blocks);
266 
267 	/**
268 	 * tell client about this block being modified right now.
269 	 * this information is required to requeue the block in case it's "on wire"
270 	 * while modification is processed by server
271 	 * @param p position of modified block
272 	 */
273 	void ResendBlockIfOnWire(v3s16 p);
274 
getSendingCount()275 	u32 getSendingCount() const { return m_blocks_sending.size(); }
276 
isBlockSent(v3s16 p)277 	bool isBlockSent(v3s16 p) const
278 	{
279 		return m_blocks_sent.find(p) != m_blocks_sent.end();
280 	}
281 
282 	// Increments timeouts and removes timed-out blocks from list
283 	// NOTE: This doesn't fix the server-not-sending-block bug
284 	//       because it is related to emerging, not sending.
285 	//void RunSendingTimeouts(float dtime, float timeout);
286 
PrintInfo(std::ostream & o)287 	void PrintInfo(std::ostream &o)
288 	{
289 		o<<"RemoteClient "<<peer_id<<": "
290 				<<"m_blocks_sent.size()="<<m_blocks_sent.size()
291 				<<", m_blocks_sending.size()="<<m_blocks_sending.size()
292 				<<", m_nearest_unsent_d="<<m_nearest_unsent_d
293 				<<", m_excess_gotblocks="<<m_excess_gotblocks
294 				<<std::endl;
295 		m_excess_gotblocks = 0;
296 	}
297 
298 	// Time from last placing or removing blocks
299 	float m_time_from_building = 9999;
300 
301 	/*
302 		List of active objects that the client knows of.
303 	*/
304 	std::set<u16> m_known_objects;
305 
getState()306 	ClientState getState() const { return m_state; }
307 
getName()308 	std::string getName() const { return m_name; }
309 
setName(const std::string & name)310 	void setName(const std::string &name) { m_name = name; }
311 
312 	/* update internal client state */
313 	void notifyEvent(ClientStateEvent event);
314 
315 	/* set expected serialization version */
setPendingSerializationVersion(u8 version)316 	void setPendingSerializationVersion(u8 version)
317 		{ m_pending_serialization_version = version; }
318 
setDeployedCompressionMode(u16 byteFlag)319 	void setDeployedCompressionMode(u16 byteFlag)
320 		{ m_deployed_compression = byteFlag; }
321 
confirmSerializationVersion()322 	void confirmSerializationVersion()
323 		{ serialization_version = m_pending_serialization_version; }
324 
325 	/* get uptime */
326 	u64 uptime() const;
327 
328 	/* set version information */
setVersionInfo(u8 major,u8 minor,u8 patch,const std::string & full)329 	void setVersionInfo(u8 major, u8 minor, u8 patch, const std::string &full)
330 	{
331 		m_version_major = major;
332 		m_version_minor = minor;
333 		m_version_patch = patch;
334 		m_full_version = full;
335 	}
336 
337 	/* read version information */
getMajor()338 	u8 getMajor() const { return m_version_major; }
getMinor()339 	u8 getMinor() const { return m_version_minor; }
getPatch()340 	u8 getPatch() const { return m_version_patch; }
getFullVer()341 	const std::string &getFullVer() const { return m_full_version; }
342 
setLangCode(const std::string & code)343 	void setLangCode(const std::string &code) { m_lang_code = code; }
getLangCode()344 	const std::string &getLangCode() const { return m_lang_code; }
345 
setCachedAddress(const Address & addr)346 	void setCachedAddress(const Address &addr) { m_addr = addr; }
getAddress()347 	const Address &getAddress() const { return m_addr; }
348 
349 private:
350 	// Version is stored in here after INIT before INIT2
351 	u8 m_pending_serialization_version = SER_FMT_VER_INVALID;
352 
353 	/* current state of client */
354 	ClientState m_state = CS_Created;
355 
356 	// Cached here so retrieval doesn't have to go to connection API
357 	Address m_addr;
358 
359 	// Client sent language code
360 	std::string m_lang_code;
361 
362 	/*
363 		Blocks that have been sent to client.
364 		- These don't have to be sent again.
365 		- A block is cleared from here when client says it has
366 		  deleted it from it's memory
367 
368 		List of block positions.
369 		No MapBlock* is stored here because the blocks can get deleted.
370 	*/
371 	std::set<v3s16> m_blocks_sent;
372 	s16 m_nearest_unsent_d = 0;
373 	v3s16 m_last_center;
374 	v3f m_last_camera_dir;
375 
376 	const u16 m_max_simul_sends;
377 	const float m_min_time_from_building;
378 	const s16 m_max_send_distance;
379 	const s16 m_block_optimize_distance;
380 	const s16 m_max_gen_distance;
381 	const bool m_occ_cull;
382 
383 	/*
384 		Blocks that are currently on the line.
385 		This is used for throttling the sending of blocks.
386 		- The size of this list is limited to some value
387 		Block is added when it is sent with BLOCKDATA.
388 		Block is removed when GOTBLOCKS is received.
389 		Value is time from sending. (not used at the moment)
390 	*/
391 	std::map<v3s16, float> m_blocks_sending;
392 
393 	/*
394 		Blocks that have been modified since blocks were
395 		sent to the client last (getNextBlocks()).
396 		This is used to reset the unsent distance, so that
397 		modified blocks are resent to the client.
398 
399 		List of block positions.
400 	*/
401 	std::set<v3s16> m_blocks_modified;
402 
403 	/*
404 		Count of excess GotBlocks().
405 		There is an excess amount because the client sometimes
406 		gets a block so late that the server sends it again,
407 		and the client then sends two GOTBLOCKs.
408 		This is resetted by PrintInfo()
409 	*/
410 	u32 m_excess_gotblocks = 0;
411 
412 	// CPU usage optimization
413 	float m_nothing_to_send_pause_timer = 0.0f;
414 
415 	/*
416 		name of player using this client
417 	*/
418 	std::string m_name = "";
419 
420 	/*
421 		client information
422 	*/
423 	u8 m_version_major = 0;
424 	u8 m_version_minor = 0;
425 	u8 m_version_patch = 0;
426 
427 	std::string m_full_version = "unknown";
428 
429 	u16 m_deployed_compression = 0;
430 
431 	/*
432 		time this client was created
433 	 */
434 	const u64 m_connection_time = porting::getTimeS();
435 };
436 
437 typedef std::unordered_map<u16, RemoteClient*> RemoteClientMap;
438 
439 class ClientInterface {
440 public:
441 
442 	friend class Server;
443 
444 	ClientInterface(const std::shared_ptr<con::Connection> &con);
445 	~ClientInterface();
446 
447 	/* run sync step */
448 	void step(float dtime);
449 
450 	/* get list of active client id's */
451 	std::vector<session_t> getClientIDs(ClientState min_state=CS_Active);
452 
453 	/* mark block as not sent to active client sessions */
454 	void markBlockposAsNotSent(const v3s16 &pos);
455 
456 	/* verify is server user limit was reached */
457 	bool isUserLimitReached();
458 
459 	/* get list of client player names */
getPlayerNames()460 	const std::vector<std::string> &getPlayerNames() const { return m_clients_names; }
461 
462 	/* send message to client */
463 	void send(session_t peer_id, u8 channelnum, NetworkPacket *pkt, bool reliable);
464 
465 	/* send to all clients */
466 	void sendToAll(NetworkPacket *pkt);
467 	void sendToAllCompat(NetworkPacket *pkt, NetworkPacket *legacypkt, u16 min_proto_ver);
468 
469 	/* delete a client */
470 	void DeleteClient(session_t peer_id);
471 
472 	/* create client */
473 	void CreateClient(session_t peer_id);
474 
475 	/* get a client by peer_id */
476 	RemoteClient *getClientNoEx(session_t peer_id,  ClientState state_min = CS_Active);
477 
478 	/* get client by peer_id (make sure you have list lock before!*/
479 	RemoteClient *lockedGetClientNoEx(session_t peer_id,  ClientState state_min = CS_Active);
480 
481 	/* get state of client by id*/
482 	ClientState getClientState(session_t peer_id);
483 
484 	/* set client playername */
485 	void setPlayerName(session_t peer_id, const std::string &name);
486 
487 	/* get protocol version of client */
488 	u16 getProtocolVersion(session_t peer_id);
489 
490 	/* set client version */
491 	void setClientVersion(session_t peer_id, u8 major, u8 minor, u8 patch,
492 			const std::string &full);
493 
494 	/* event to update client state */
495 	void event(session_t peer_id, ClientStateEvent event);
496 
497 	/* Set environment. Do not call this function if environment is already set */
setEnv(ServerEnvironment * env)498 	void setEnv(ServerEnvironment *env)
499 	{
500 		assert(m_env == NULL); // pre-condition
501 		m_env = env;
502 	}
503 
504 	static std::string state2Name(ClientState state);
505 protected:
506 	//TODO find way to avoid this functions
lock()507 	void lock() { m_clients_mutex.lock(); }
unlock()508 	void unlock() { m_clients_mutex.unlock(); }
509 
getClientList()510 	RemoteClientMap& getClientList() { return m_clients; }
511 
512 private:
513 	/* update internal player list */
514 	void UpdatePlayerList();
515 
516 	// Connection
517 	std::shared_ptr<con::Connection> m_con;
518 	std::recursive_mutex m_clients_mutex;
519 	// Connected clients (behind the con mutex)
520 	RemoteClientMap m_clients;
521 	std::vector<std::string> m_clients_names; //for announcing masterserver
522 
523 	// Environment
524 	ServerEnvironment *m_env;
525 
526 	float m_print_info_timer;
527 
528 	static const char *statenames[];
529 };
530