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
|
//
// async_udp_echo_server.cpp
// ~~~~~~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2023 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#include <cstdlib>
#include <iostream>
#include <boost/asio/ts/buffer.hpp>
#include <boost/asio/ts/internet.hpp>
using boost::asio::ip::udp;
class server
{
public:
server(boost::asio::io_context& io_context, short port)
: socket_(io_context, udp::endpoint(udp::v4(), port))
{
do_receive();
}
void do_receive()
{
socket_.async_receive_from(
boost::asio::buffer(data_, max_length), sender_endpoint_,
[this](boost::system::error_code ec, std::size_t bytes_recvd)
{
if (!ec && bytes_recvd > 0)
{
do_send(bytes_recvd);
}
else
{
do_receive();
}
});
}
void do_send(std::size_t length)
{
socket_.async_send_to(
boost::asio::buffer(data_, length), sender_endpoint_,
[this](boost::system::error_code /*ec*/, std::size_t /*bytes_sent*/)
{
do_receive();
});
}
private:
udp::socket socket_;
udp::endpoint sender_endpoint_;
enum { max_length = 1024 };
char data_[max_length];
};
int main(int argc, char* argv[])
{
try
{
if (argc != 2)
{
std::cerr << "Usage: async_udp_echo_server <port>\n";
return 1;
}
boost::asio::io_context io_context;
server s(io_context, std::atoi(argv[1]));
io_context.run();
}
catch (std::exception& e)
{
std::cerr << "Exception: " << e.what() << "\n";
}
return 0;
}
|
