summaryrefslogtreecommitdiff
path: root/src/network/network_command.cpp
blob: d43e971ff956646579fa2050b5fce843b93d1005 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file network_command.cpp Command handling over network connections. */

#include "../stdafx.h"
#include "network_admin.h"
#include "network_client.h"
#include "network_server.h"
#include "../command_func.h"
#include "../company_func.h"
#include "../settings_type.h"

#include "../safeguards.h"

/** Table with all the callbacks we'll use for conversion*/
static CommandCallback * const _callback_table[] = {
	/* 0x00 */ nullptr,
	/* 0x01 */ CcBuildPrimaryVehicle,
	/* 0x02 */ CcBuildAirport,
	/* 0x03 */ CcBuildBridge,
	/* 0x04 */ CcPlaySound_CONSTRUCTION_WATER,
	/* 0x05 */ CcBuildDocks,
	/* 0x06 */ CcFoundTown,
	/* 0x07 */ CcBuildRoadTunnel,
	/* 0x08 */ CcBuildRailTunnel,
	/* 0x09 */ CcBuildWagon,
	/* 0x0A */ CcRoadDepot,
	/* 0x0B */ CcRailDepot,
	/* 0x0C */ CcPlaceSign,
	/* 0x0D */ CcPlaySound_EXPLOSION,
	/* 0x0E */ CcPlaySound_CONSTRUCTION_OTHER,
	/* 0x0F */ CcPlaySound_CONSTRUCTION_RAIL,
	/* 0x10 */ CcStation,
	/* 0x11 */ CcTerraform,
	/* 0x12 */ CcAI,
	/* 0x13 */ CcCloneVehicle,
	/* 0x14 */ nullptr,
	/* 0x15 */ CcCreateGroup,
	/* 0x16 */ CcFoundRandomTown,
	/* 0x17 */ CcRoadStop,
	/* 0x18 */ CcBuildIndustry,
	/* 0x19 */ CcStartStopVehicle,
	/* 0x1A */ CcGame,
	/* 0x1B */ CcAddVehicleNewGroup,
};

/**
 * Append a CommandPacket at the end of the queue.
 * @param p The packet to append to the queue.
 * @note A new instance of the CommandPacket will be made.
 */
void CommandQueue::Append(CommandPacket *p)
{
	CommandPacket *add = new CommandPacket();
	*add = *p;
	add->next = nullptr;
	if (this->first == nullptr) {
		this->first = add;
	} else {
		this->last->next = add;
	}
	this->last = add;
	this->count++;
}

/**
 * Return the first item in the queue and remove it from the queue.
 * @param ignore_paused Whether to ignore commands that may not be executed while paused.
 * @return the first item in the queue.
 */
CommandPacket *CommandQueue::Pop(bool ignore_paused)
{
	CommandPacket **prev = &this->first;
	CommandPacket *ret = this->first;
	CommandPacket *prev_item = nullptr;
	if (ignore_paused && _pause_mode != PM_UNPAUSED) {
		while (ret != nullptr && !IsCommandAllowedWhilePaused(ret->cmd)) {
			prev_item = ret;
			prev = &ret->next;
			ret = ret->next;
		}
	}
	if (ret != nullptr) {
		if (ret == this->last) this->last = prev_item;
		*prev = ret->next;
		this->count--;
	}
	return ret;
}

/**
 * Return the first item in the queue, but don't remove it.
 * @param ignore_paused Whether to ignore commands that may not be executed while paused.
 * @return the first item in the queue.
 */
CommandPacket *CommandQueue::Peek(bool ignore_paused)
{
	if (!ignore_paused || _pause_mode == PM_UNPAUSED) return this->first;

	for (CommandPacket *p = this->first; p != nullptr; p = p->next) {
		if (IsCommandAllowedWhilePaused(p->cmd)) return p;
	}
	return nullptr;
}

/** Free everything that is in the queue. */
void CommandQueue::Free()
{
	CommandPacket *cp;
	while ((cp = this->Pop()) != nullptr) {
		delete cp;
	}
	assert(this->count == 0);
}

/** Local queue of packets waiting for handling. */
static CommandQueue _local_wait_queue;
/** Local queue of packets waiting for execution. */
static CommandQueue _local_execution_queue;

/**
 * Prepare a DoCommand to be send over the network
 * @param tile The tile to perform a command on (see #CommandProc)
 * @param p1 Additional data for the command (see #CommandProc)
 * @param p2 Additional data for the command (see #CommandProc)
 * @param cmd The command to execute (a CMD_* value)
 * @param callback A callback function to call after the command is finished
 * @param text The text to pass
 * @param company The company that wants to send the command
 */
void NetworkSendCommand(TileIndex tile, uint32 p1, uint32 p2, uint32 cmd, CommandCallback *callback, const std::string &text, CompanyID company)
{
	assert((cmd & CMD_FLAGS_MASK) == 0);

	CommandPacket c;
	c.company  = company;
	c.tile     = tile;
	c.p1       = p1;
	c.p2       = p2;
	c.cmd      = cmd;
	c.callback = callback;
	c.text     = text;

	if (_network_server) {
		/* If we are the server, we queue the command in our 'special' queue.
		 *   In theory, we could execute the command right away, but then the
		 *   client on the server can do everything 1 tick faster than others.
		 *   So to keep the game fair, we delay the command with 1 tick
		 *   which gives about the same speed as most clients.
		 */
		c.frame = _frame_counter_max + 1;
		c.my_cmd = true;

		_local_wait_queue.Append(&c);
		return;
	}

	c.frame = 0; // The client can't tell which frame, so just make it 0

	/* Clients send their command to the server and forget all about the packet */
	MyClient::SendCommand(&c);
}

/**
 * Sync our local command queue to the command queue of the given
 * socket. This is needed for the case where we receive a command
 * before saving the game for a joining client, but without the
 * execution of those commands. Not syncing those commands means
 * that the client will never get them and as such will be in a
 * desynced state from the time it started with joining.
 * @param cs The client to sync the queue to.
 */
void NetworkSyncCommandQueue(NetworkClientSocket *cs)
{
	for (CommandPacket *p = _local_execution_queue.Peek(); p != nullptr; p = p->next) {
		CommandPacket c = *p;
		c.callback = 0;
		cs->outgoing_queue.Append(&c);
	}
}

/**
 * Execute all commands on the local command queue that ought to be executed this frame.
 */
void NetworkExecuteLocalCommandQueue()
{
	assert(IsLocalCompany());

	CommandQueue &queue = (_network_server ? _local_execution_queue : ClientNetworkGameSocketHandler::my_client->incoming_queue);

	CommandPacket *cp;
	while ((cp = queue.Peek()) != nullptr) {
		/* The queue is always in order, which means
		 * that the first element will be executed first. */
		if (_frame_counter < cp->frame) break;

		if (_frame_counter > cp->frame) {
			/* If we reach here, it means for whatever reason, we've already executed
			 * past the command we need to execute. */
			error("[net] Trying to execute a packet in the past!");
		}

		/* We can execute this command */
		_current_company = cp->company;
		cp->cmd |= CMD_NETWORK_COMMAND;
		DoCommandP(cp, cp->my_cmd);

		queue.Pop();
		delete cp;
	}

	/* Local company may have changed, so we should not restore the old value */
	_current_company = _local_company;
}

/**
 * Free the local command queues.
 */
void NetworkFreeLocalCommandQueue()
{
	_local_wait_queue.Free();
	_local_execution_queue.Free();
}

/**
 * "Send" a particular CommandPacket to all clients.
 * @param cp    The command that has to be distributed.
 * @param owner The client that owns the command,
 */
static void DistributeCommandPacket(CommandPacket &cp, const NetworkClientSocket *owner)
{
	CommandCallback *callback = cp.callback;
	cp.frame = _frame_counter_max + 1;

	for (NetworkClientSocket *cs : NetworkClientSocket::Iterate()) {
		if (cs->status >= NetworkClientSocket::STATUS_MAP) {
			/* Callbacks are only send back to the client who sent them in the
			 *  first place. This filters that out. */
			cp.callback = (cs != owner) ? nullptr : callback;
			cp.my_cmd = (cs == owner);
			cs->outgoing_queue.Append(&cp);
		}
	}

	cp.callback = (nullptr != owner) ? nullptr : callback;
	cp.my_cmd = (nullptr == owner);
	_local_execution_queue.Append(&cp);
}

/**
 * "Send" a particular CommandQueue to all clients.
 * @param queue The queue of commands that has to be distributed.
 * @param owner The client that owns the commands,
 */
static void DistributeQueue(CommandQueue *queue, const NetworkClientSocket *owner)
{
#ifdef DEBUG_DUMP_COMMANDS
	/* When replaying we do not want this limitation. */
	int to_go = UINT16_MAX;
#else
	int to_go = _settings_client.network.commands_per_frame;
#endif

	CommandPacket *cp;
	while (--to_go >= 0 && (cp = queue->Pop(true)) != nullptr) {
		DistributeCommandPacket(*cp, owner);
		NetworkAdminCmdLogging(owner, cp);
		delete cp;
	}
}

/** Distribute the commands of ourself and the clients. */
void NetworkDistributeCommands()
{
	/* First send the server's commands. */
	DistributeQueue(&_local_wait_queue, nullptr);

	/* Then send the queues of the others. */
	for (NetworkClientSocket *cs : NetworkClientSocket::Iterate()) {
		DistributeQueue(&cs->incoming_queue, cs);
	}
}

/**
 * Receives a command from the network.
 * @param p the packet to read from.
 * @param cp the struct to write the data to.
 * @return an error message. When nullptr there has been no error.
 */
const char *NetworkGameSocketHandler::ReceiveCommand(Packet *p, CommandPacket *cp)
{
	cp->company = (CompanyID)p->Recv_uint8();
	cp->cmd     = p->Recv_uint32();
	if (!IsValidCommand(cp->cmd))               return "invalid command";
	if (GetCommandFlags(cp->cmd) & CMD_OFFLINE) return "single-player only command";
	if ((cp->cmd & CMD_FLAGS_MASK) != 0)        return "invalid command flag";

	cp->p1      = p->Recv_uint32();
	cp->p2      = p->Recv_uint32();
	cp->tile    = p->Recv_uint32();
	cp->text    = p->Recv_string(NETWORK_COMPANY_NAME_LENGTH, (!_network_server && GetCommandFlags(cp->cmd) & CMD_STR_CTRL) != 0 ? SVS_ALLOW_CONTROL_CODE | SVS_REPLACE_WITH_QUESTION_MARK : SVS_REPLACE_WITH_QUESTION_MARK);

	byte callback = p->Recv_uint8();
	if (callback >= lengthof(_callback_table))  return "invalid callback";

	cp->callback = _callback_table[callback];
	return nullptr;
}

/**
 * Sends a command over the network.
 * @param p the packet to send it in.
 * @param cp the packet to actually send.
 */
void NetworkGameSocketHandler::SendCommand(Packet *p, const CommandPacket *cp)
{
	p->Send_uint8 (cp->company);
	p->Send_uint32(cp->cmd);
	p->Send_uint32(cp->p1);
	p->Send_uint32(cp->p2);
	p->Send_uint32(cp->tile);
	p->Send_string(cp->text);

	byte callback = 0;
	while (callback < lengthof(_callback_table) && _callback_table[callback] != cp->callback) {
		callback++;
	}

	if (callback == lengthof(_callback_table)) {
		DEBUG(net, 0, "Unknown callback for command; no callback sent (command: %d)", cp->cmd);
		callback = 0; // _callback_table[0] == nullptr
	}
	p->Send_uint8 (callback);
}