aboutsummaryrefslogtreecommitdiffstats
path: root/src/client/Client.hxx
blob: 0e3047d584e4ebd1a2a03ae4ec9bbc34b89049eb (plain) (blame)
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
/*
 * Copyright (C) 2003-2015 The Music Player Daemon Project
 * http://www.musicpd.org
 *
 * This program 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; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#ifndef MPD_CLIENT_H
#define MPD_CLIENT_H

#include "check.h"
#include "ClientMessage.hxx"
#include "command/CommandListBuilder.hxx"
#include "event/FullyBufferedSocket.hxx"
#include "event/TimeoutMonitor.hxx"
#include "Compiler.h"

#include <boost/intrusive/list.hpp>

#include <set>
#include <string>
#include <list>

#include <stddef.h>
#include <stdarg.h>

class SocketAddress;
class EventLoop;
class Path;
struct Partition;
class Database;
class Storage;

class Client final
	: FullyBufferedSocket, TimeoutMonitor,
	  public boost::intrusive::list_base_hook<boost::intrusive::link_mode<boost::intrusive::normal_link>> {
public:
	Partition &partition;
	struct playlist &playlist;
	struct PlayerControl &player_control;

	struct Disposer {
		void operator()(Client *client) const {
			delete client;
		}
	};

	unsigned permission;

	/** the uid of the client process, or -1 if unknown */
	int uid;

	CommandListBuilder cmd_list;

	unsigned int num;	/* client number */

	/** is this client waiting for an "idle" response? */
	bool idle_waiting;

	/** idle flags pending on this client, to be sent as soon as
	    the client enters "idle" */
	unsigned idle_flags;

	/** idle flags that the client wants to receive */
	unsigned idle_subscriptions;

	/**
	 * A list of channel names this client is subscribed to.
	 */
	std::set<std::string> subscriptions;

	/**
	 * The number of subscriptions in #subscriptions.  Used to
	 * limit the number of subscriptions.
	 */
	unsigned num_subscriptions;

	/**
	 * A list of messages this client has received.
	 */
	std::list<ClientMessage> messages;

	Client(EventLoop &loop, Partition &partition,
	       int fd, int uid, int num);

	~Client() {
		if (FullyBufferedSocket::IsDefined())
			FullyBufferedSocket::Close();
	}

	bool IsConnected() const {
		return FullyBufferedSocket::IsDefined();
	}

	gcc_pure
	bool IsExpired() const {
		return !FullyBufferedSocket::IsDefined();
	}

	void Close();
	void SetExpired();

	bool Write(const void *data, size_t length);

	/**
	 * returns the uid of the client process, or a negative value
	 * if the uid is unknown
	 */
	int GetUID() const {
		return uid;
	}

	/**
	 * Is this client running on the same machine, connected with
	 * a local (UNIX domain) socket?
	 */
	bool IsLocal() const {
		return uid >= 0;
	}

	unsigned GetPermission() const {
		return permission;
	}

	void SetPermission(unsigned _permission) {
		permission = _permission;
	}

	/**
	 * Send "idle" response to this client.
	 */
	void IdleNotify();
	void IdleAdd(unsigned flags);
	bool IdleWait(unsigned flags);

	enum class SubscribeResult {
		/** success */
		OK,

		/** invalid channel name */
		INVALID,

		/** already subscribed to this channel */
		ALREADY,

		/** too many subscriptions */
		FULL,
	};

	gcc_pure
	bool IsSubscribed(const char *channel_name) const {
		return subscriptions.find(channel_name) != subscriptions.end();
	}

	SubscribeResult Subscribe(const char *channel);
	bool Unsubscribe(const char *channel);
	void UnsubscribeAll();
	bool PushMessage(const ClientMessage &msg);

	/**
	 * Is this client allowed to use the specified local file?
	 *
	 * Note that this function is vulnerable to timing/symlink attacks.
	 * We cannot fix this as long as there are plugins that open a file by
	 * its name, and not by file descriptor / callbacks.
	 *
	 * @param path_fs the absolute path name in filesystem encoding
	 * @return true if access is allowed
	 */
	bool AllowFile(Path path_fs, Error &error) const;

	/**
	 * Wrapper for Instance::GetDatabase().
	 */
	gcc_pure
	const Database *GetDatabase(Error &error) const;

	gcc_pure
	const Storage *GetStorage() const;

private:
	/* virtual methods from class BufferedSocket */
	virtual InputResult OnSocketInput(void *data, size_t length) override;
	virtual void OnSocketError(Error &&error) override;
	virtual void OnSocketClosed() override;

	/* virtual methods from class TimeoutMonitor */
	virtual void OnTimeout() override;
};

void
client_manager_init();

void
client_new(EventLoop &loop, Partition &partition,
	   int fd, SocketAddress address, int uid);

/**
 * Write a C string to the client.
 */
void client_puts(Client &client, const char *s);

/**
 * Write a printf-like formatted string to the client.
 */
void client_vprintf(Client &client, const char *fmt, va_list args);

/**
 * Write a printf-like formatted string to the client.
 */
gcc_printf(2,3)
void
client_printf(Client &client, const char *fmt, ...);

#endif