Line data Source code
1 : // Copyright (c) 2012-2022 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 along
17 : // with this program; if not, write to the Free Software Foundation, Inc.,
18 : // 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 : // self
43 : //
44 : #include "eventdispatcher/tcp_server_client_message_connection.h"
45 :
46 : #include "eventdispatcher/exception.h"
47 :
48 :
49 : // snaplogger lib
50 : //
51 : #include <snaplogger/message.h>
52 :
53 :
54 : // C++ lib
55 : //
56 : #include <cstring>
57 :
58 :
59 : // C lib
60 : //
61 : #include <arpa/inet.h>
62 : #include <sys/socket.h>
63 :
64 :
65 : // last include
66 : //
67 : #include <snapdev/poison.h>
68 :
69 :
70 :
71 : namespace ed
72 : {
73 :
74 :
75 :
76 : /** \brief Initializes a client to read messages from a socket.
77 : *
78 : * This implementation creates a message in/out client.
79 : * This is the most useful client in our Snap! Communicator
80 : * as it directly sends and receives messages.
81 : *
82 : * \param[in] client The client representing the in/out socket.
83 : */
84 0 : tcp_server_client_message_connection::tcp_server_client_message_connection(tcp_bio_client::pointer_t client)
85 0 : : tcp_server_client_buffer_connection(client)
86 : {
87 : // TODO: somehow the port seems wrong (i.e. all connections return the same port)
88 : // I changed this to do the getpeername() at the time you call the
89 : // get_remote_address() and I use the addr::addr get_from_socket()
90 : // so now it may work? I need to test it again
91 :
92 : // make sure the socket is defined and well
93 : //
94 0 : int const socket(client->get_socket());
95 0 : if(socket < 0)
96 : {
97 0 : SNAP_LOG_ERROR
98 : << "called with a closed client connection."
99 : << SNAP_LOG_SEND;
100 0 : throw std::runtime_error("tcp_server_client_message_connection() called with a closed client connection.");
101 : }
102 0 : }
103 :
104 :
105 : /** \brief Process a line (string) just received.
106 : *
107 : * The function parses the line as a message and then calls the
108 : * process_message() function if the line was valid.
109 : *
110 : * \param[in] line The line of text that was just read.
111 : */
112 0 : void tcp_server_client_message_connection::process_line(std::string const & line)
113 : {
114 : // empty lines should not occur, but just in case, just ignore
115 0 : if(line.empty())
116 : {
117 0 : return;
118 : }
119 :
120 0 : message msg;
121 0 : if(msg.from_message(line))
122 : {
123 0 : dispatch_message(msg);
124 : }
125 : else
126 : {
127 : // TODO: what to do here? This could because the version changed
128 : // and the messages are not compatible anymore.
129 : //
130 0 : SNAP_LOG_ERROR
131 : << "process_line() was asked to process an invalid message ("
132 : << line
133 : << ")"
134 : << SNAP_LOG_SEND;
135 : }
136 : }
137 :
138 :
139 : /** \brief Send a message.
140 : *
141 : * This function sends a message to the client on the other side
142 : * of this connection.
143 : *
144 : * \exception event_dispatcher_runtime_error
145 : * This function throws this exception if the write() to the pipe
146 : * fails to write the entire message. This should only happen if
147 : * the pipe gets severed.
148 : *
149 : * \param[in] msg The message to be processed.
150 : * \param[in] cache Whether to cache the message if there is no connection.
151 : * (Ignore because a client socket has to be there until
152 : * closed and then it can't be reopened by the server.)
153 : *
154 : * \return Always true. If an error occurs the function throws.
155 : */
156 0 : bool tcp_server_client_message_connection::send_message(
157 : message & msg
158 : , bool cache)
159 : {
160 0 : snapdev::NOT_USED(cache);
161 :
162 : // transform the message to a string and write to the socket
163 : // the writing is asynchronous so the message is saved in a cache
164 : // and transferred only later when the run() loop is hit again
165 : //
166 0 : std::string buf(msg.to_message());
167 0 : buf += '\n';
168 0 : return write(buf.c_str(), buf.length()) == static_cast<ssize_t>(buf.length());
169 : }
170 :
171 :
172 : /** \brief Retrieve the remote address information.
173 : *
174 : * This function can be used to retrieve the remove address and port
175 : * information as was specified on the constructor. These can be used
176 : * to find this specific connection at a later time or create another
177 : * connection.
178 : *
179 : * For example, you may get 192.168.2.17:4040.
180 : *
181 : * The function works even after the socket gets closed as we save
182 : * the remote address and port in a string just after the connection
183 : * was established.
184 : *
185 : * \warning
186 : * This function returns BOTH: the address and the port.
187 : *
188 : * \note
189 : * These parameters are the same as what was passed to the constructor,
190 : * only both will have been converted to numbers. So for example when
191 : * you used "localhost", here you get "::1" or "127.0.0.1" for the
192 : * address.
193 : *
194 : * \return The remote host address and connection port.
195 : */
196 0 : addr::addr tcp_server_client_message_connection::get_remote_address()
197 : {
198 0 : if(f_remote_address.is_default())
199 : {
200 0 : int const s(get_socket());
201 0 : if(s >= 0)
202 : {
203 0 : f_remote_address.set_from_socket(s, true);
204 : }
205 : }
206 :
207 0 : return f_remote_address;
208 : }
209 :
210 :
211 6 : } // namespace ed
212 : // vim: ts=4 sw=4 et
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