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1 : // Copyright (c) 2012-2019 Made to Order Software Corp. All Rights Reserved
2 : //
3 : // https://snapwebsites.org/project/eventdispatcher
4 : // contact@m2osw.com
5 : //
6 : // This program is free software; you can redistribute it and/or modify
7 : // it under the terms of the GNU General Public License as published by
8 : // the Free Software Foundation; either version 2 of the License, or
9 : // (at your option) any later version.
10 : //
11 : // This program is distributed in the hope that it will be useful,
12 : // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 : // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 : // GNU General Public License for more details.
15 : //
16 : // You should have received a copy of the GNU General Public License
17 : // along with this program; if not, write to the Free Software
18 : // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 :
20 : /** \file
21 : * \brief Implementation of the Snap Communicator class.
22 : *
23 : * This class wraps the C poll() interface in a C++ object with many types
24 : * of objects:
25 : *
26 : * \li Server Connections; for software that want to offer a port to
27 : * which clients can connect to; the server will call accept()
28 : * once a new client connection is ready; this results in a
29 : * Server/Client connection object
30 : * \li Client Connections; for software that want to connect to
31 : * a server; these expect the IP address and port to connect to
32 : * \li Server/Client Connections; for the server when it accepts a new
33 : * connection; in this case the server gets a socket from accept()
34 : * and creates one of these objects to handle the connection
35 : *
36 : * Using the poll() function is the easiest and allows us to listen
37 : * on pretty much any number of sockets (on my server it is limited
38 : * at 16,768 and frankly over 1,000 we probably will start to have
39 : * real slowness issues on small VPN servers.)
40 : */
41 :
42 :
43 : // self
44 : //
45 : #include "eventdispatcher/tcp_client_connection.h"
46 :
47 :
48 : // last include
49 : //
50 : #include <snapdev/poison.h>
51 :
52 :
53 :
54 : namespace ed
55 : {
56 :
57 :
58 :
59 : /** \brief Initializes the client connection.
60 : *
61 : * This function creates a connection using the address, port, and mode
62 : * parameters. This is very similar to using the bio_client class to
63 : * create a connection, only the resulting connection can be used with
64 : * the snap_communicator object.
65 : *
66 : * \note
67 : * The function also saves the remote address and port used to open
68 : * the connection which can later be retrieved using the
69 : * get_remote_address() function. That address will remain valid
70 : * even after the socket is closed.
71 : *
72 : * \todo
73 : * If the remote address is an IPv6, we need to put it between [...]
74 : * (i.e. [::1]:4040) so we can extract the port safely.
75 : *
76 : * \param[in] communicator The snap communicator controlling this connection.
77 : * \param[in] addr The address of the server to connect to.
78 : * \param[in] port The port to connect to.
79 : * \param[in] mode Type of connection: plain or secure.
80 : */
81 0 : tcp_client_connection::tcp_client_connection(std::string const & addr, int port, mode_t mode)
82 : : tcp_bio_client(addr, port, mode)
83 0 : , f_remote_address(get_client_addr() + ":" + std::to_string(get_client_port()))
84 : {
85 0 : }
86 :
87 :
88 : /** \brief Retrieve the remote address information.
89 : *
90 : * This function can be used to retrieve the remove address and port
91 : * information as was specified on the constructor. These can be used
92 : * to find this specific connection at a later time or create another
93 : * connection.
94 : *
95 : * For example, you may get 192.168.2.17:4040.
96 : *
97 : * The function works even after the socket gets closed as we save
98 : * the remote address and port in a string just after the connection
99 : * was established.
100 : *
101 : * \note
102 : * These parameters are the same as what was passed to the constructor,
103 : * only both will have been converted to numbers. So for example when
104 : * you used "localhost", here you get "::1" or "127.0.0.1" for the
105 : * address.
106 : *
107 : * \return The remote host address and connection port.
108 : */
109 0 : std::string const & tcp_client_connection::get_remote_address() const
110 : {
111 0 : return f_remote_address;
112 : }
113 :
114 :
115 : /** \brief Read from the client socket.
116 : *
117 : * This function reads data from the client socket and copy it in
118 : * \p buf. A maximum of \p count bytes are read.
119 : *
120 : * \param[in,out] buf The buffer where the data is read.
121 : * \param[in] count The maximum number of bytes to read.
122 : *
123 : * \return -1 if an error occurs, zero if no data gets read, a positive
124 : * number representing the number of bytes read otherwise.
125 : */
126 0 : ssize_t tcp_client_connection::read(void * buf, size_t count)
127 : {
128 0 : if(get_socket() == -1)
129 : {
130 0 : errno = EBADF;
131 0 : return -1;
132 : }
133 0 : return tcp_bio_client::read(reinterpret_cast<char *>(buf), count);
134 : }
135 :
136 :
137 : /** \brief Write to the client socket.
138 : *
139 : * This function writes \p count bytes from \p buf to this
140 : * client socket.
141 : *
142 : * The function can safely be called after the socket was closed, although
143 : * it will return -1 and set errno to EBADF in tha case.
144 : *
145 : * \param[in] buf The buffer to write to the client connection socket.
146 : * \param[in] count The maximum number of bytes to write on this connection.
147 : *
148 : * \return -1 if an error occurs, zero if nothing was written, a positive
149 : * number representing the number of bytes successfully written.
150 : */
151 0 : ssize_t tcp_client_connection::write(void const * buf, size_t count)
152 : {
153 0 : if(get_socket() == -1)
154 : {
155 0 : errno = EBADF;
156 0 : return -1;
157 : }
158 0 : return tcp_bio_client::write(reinterpret_cast<char const *>(buf), count);
159 : }
160 :
161 :
162 : /** \brief Check whether this connection is a reader.
163 : *
164 : * We change the default to true since TCP sockets are generally
165 : * always readers. You can still overload this function and
166 : * return false if necessary.
167 : *
168 : * However, we do not overload the is_writer() because that is
169 : * much more dynamic (i.e. you do not want to advertise as
170 : * being a writer unless you have data to write to the
171 : * socket.)
172 : *
173 : * \return The events to listen to for this connection.
174 : */
175 0 : bool tcp_client_connection::is_reader() const
176 : {
177 0 : return true;
178 : }
179 :
180 :
181 : /** \brief Retrieve the socket of this client connection.
182 : *
183 : * This function retrieves the socket this client connection. In this case
184 : * the socket is defined in the bio_client class.
185 : *
186 : * \return The socket of this client connection.
187 : */
188 0 : int tcp_client_connection::get_socket() const
189 : {
190 0 : return tcp_bio_client::get_socket();
191 : }
192 :
193 :
194 :
195 : } // namespace ed
196 : // vim: ts=4 sw=4 et
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