1/*
2 Copyright (c) 2007-2016 Contributors as noted in the AUTHORS file
3
4 This file is part of libzmq, the ZeroMQ core engine in C++.
5
6 libzmq is free software; you can redistribute it and/or modify it under
7 the terms of the GNU Lesser General Public License (LGPL) as published
8 by the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
10
11 As a special exception, the Contributors give you permission to link
12 this library with independent modules to produce an executable,
13 regardless of the license terms of these independent modules, and to
14 copy and distribute the resulting executable under terms of your choice,
15 provided that you also meet, for each linked independent module, the
16 terms and conditions of the license of that module. An independent
17 module is a module which is not derived from or based on this library.
18 If you modify this library, you must extend this exception to your
19 version of the library.
20
21 libzmq is distributed in the hope that it will be useful, but WITHOUT
22 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
23 FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
24 License for more details.
25
26 You should have received a copy of the GNU Lesser General Public License
27 along with this program. If not, see <http://www.gnu.org/licenses/>.
28*/
29
30#ifndef __ZMQ_STREAM_ENGINE_BASE_HPP_INCLUDED__
31#define __ZMQ_STREAM_ENGINE_BASE_HPP_INCLUDED__
32
33#include <stddef.h>
34
35#include "fd.hpp"
36#include "i_engine.hpp"
37#include "io_object.hpp"
38#include "i_encoder.hpp"
39#include "i_decoder.hpp"
40#include "options.hpp"
41#include "socket_base.hpp"
42#include "metadata.hpp"
43#include "msg.hpp"
44#include "tcp.hpp"
45
46namespace zmq
47{
48class io_thread_t;
49class session_base_t;
50class mechanism_t;
51
52// This engine handles any socket with SOCK_STREAM semantics,
53// e.g. TCP socket or an UNIX domain socket.
54
55class stream_engine_base_t : public io_object_t, public i_engine
56{
57 public:
58 stream_engine_base_t (fd_t fd_,
59 const options_t &options_,
60 const endpoint_uri_pair_t &endpoint_uri_pair_);
61 ~stream_engine_base_t ();
62
63 // i_engine interface implementation.
64 void plug (zmq::io_thread_t *io_thread_, zmq::session_base_t *session_);
65 void terminate ();
66 bool restart_input ();
67 void restart_output ();
68 void zap_msg_available ();
69 const endpoint_uri_pair_t &get_endpoint () const;
70
71 // i_poll_events interface implementation.
72 void in_event ();
73 void out_event ();
74 void timer_event (int id_);
75
76 protected:
77 typedef metadata_t::dict_t properties_t;
78 bool init_properties (properties_t &properties_);
79
80 // Function to handle network disconnections.
81 virtual void error (error_reason_t reason_);
82
83 int next_handshake_command (msg_t *msg_);
84 int process_handshake_command (msg_t *msg_);
85
86 int pull_msg_from_session (msg_t *msg_);
87 int push_msg_to_session (msg_t *msg_);
88
89 int pull_and_encode (msg_t *msg_);
90 int decode_and_push (msg_t *msg_);
91
92 void set_handshake_timer ();
93
94 virtual bool handshake () { return true; };
95 virtual void plug_internal (){};
96
97 virtual int process_command_message (msg_t *msg_) { return -1; };
98 virtual int produce_ping_message (msg_t *msg_) { return -1; };
99 virtual int process_heartbeat_message (msg_t *msg_) { return -1; };
100 virtual int produce_pong_message (msg_t *msg_) { return -1; };
101
102 virtual int read (void *data, size_t size_);
103 virtual int write (const void *data_, size_t size_);
104
105 void reset_pollout () { io_object_t::reset_pollout (_handle); }
106 void set_pollout () { io_object_t::set_pollout (_handle); }
107 void set_pollin () { io_object_t::set_pollin (_handle); }
108 session_base_t *session () { return _session; }
109 socket_base_t *socket () { return _socket; }
110
111 const options_t _options;
112
113 unsigned char *_inpos;
114 size_t _insize;
115 i_decoder *_decoder;
116
117 unsigned char *_outpos;
118 size_t _outsize;
119 i_encoder *_encoder;
120
121 mechanism_t *_mechanism;
122
123 int (stream_engine_base_t::*_next_msg) (msg_t *msg_);
124 int (stream_engine_base_t::*_process_msg) (msg_t *msg_);
125
126 // Metadata to be attached to received messages. May be NULL.
127 metadata_t *_metadata;
128
129 // True iff the engine couldn't consume the last decoded message.
130 bool _input_stopped;
131
132 // True iff the engine doesn't have any message to encode.
133 bool _output_stopped;
134
135 // Representation of the connected endpoints.
136 const endpoint_uri_pair_t _endpoint_uri_pair;
137
138 // ID of the handshake timer
139 enum
140 {
141 handshake_timer_id = 0x40
142 };
143
144 // True is linger timer is running.
145 bool _has_handshake_timer;
146
147 // Heartbeat stuff
148 enum
149 {
150 heartbeat_ivl_timer_id = 0x80,
151 heartbeat_timeout_timer_id = 0x81,
152 heartbeat_ttl_timer_id = 0x82
153 };
154 bool _has_ttl_timer;
155 bool _has_timeout_timer;
156 bool _has_heartbeat_timer;
157
158
159 const std::string _peer_address;
160
161 private:
162 bool in_event_internal ();
163
164 // Unplug the engine from the session.
165 void unplug ();
166
167 int write_credential (msg_t *msg_);
168 int push_one_then_decode_and_push (msg_t *msg_);
169
170 void mechanism_ready ();
171
172 // Underlying socket.
173 fd_t _s;
174
175 handle_t _handle;
176
177 bool _plugged;
178
179 // When true, we are still trying to determine whether
180 // the peer is using versioned protocol, and if so, which
181 // version. When false, normal message flow has started.
182 bool _handshaking;
183
184 msg_t _tx_msg;
185
186 bool _io_error;
187
188 // The session this engine is attached to.
189 zmq::session_base_t *_session;
190
191 // Socket
192 zmq::socket_base_t *_socket;
193
194 ZMQ_NON_COPYABLE_NOR_MOVABLE (stream_engine_base_t)
195};
196}
197
198#endif
199