Question

我正在尝试使用多播接收器的示例来侦听通过网络发送UDP多播数据的应用程序。

收听IP为193.x.x.107
发件人IP为193.x.x.109
组播地址为231.11.1.5:6005

这是一个Wireshark数据捕获，以确保数据通过：

以下是来自boost库的代码：

 //
 // receiver.cpp
 // ~~~~~~~~~~~~
 //
 // Copyright (c) 2003-2017 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 <iostream>
 #include <string>
 #include <boost/asio.hpp>
 #include "boost/bind.hpp"

 const short multicast_port = 6005;

 class receiver
 {
      public:
        receiver(boost::asio::io_service& io_service,
        const boost::asio::ip::address& listen_address,
        const boost::asio::ip::address& multicast_address)
        : socket_(io_service)
 {
     // Create the socket so that multiple may be bound to the same           address.
     boost::asio::ip::udp::endpoint listen_endpoint(listen_address, multicast_port);
     socket_.open(listen_endpoint.protocol());
     socket_.set_option(boost::asio::ip::udp::socket::reuse_address(true));
     socket_.bind(listen_endpoint);

     std::cout << "Socket Created : " << std::endl;

     // Join the multicast group.
    socket_.set_option(
         boost::asio::ip::multicast::join_group(multicast_address));

    socket_.async_receive_from(
        boost::asio::buffer(data_, max_length), sender_endpoint_,
        boost::bind(&receiver::handle_receive_from, this,
        boost::asio::placeholders::error,
        boost::asio::placeholders::bytes_transferred));

    std::cout << "Mutilcast Group Joined : " << std::endl;
}

void handle_receive_from(const boost::system::error_code& error,
  size_t bytes_recvd)
{
     if (!error)
     {
         std::cout.write(data_, bytes_recvd);
         std::cout << std::endl;

         socket_.async_receive_from(
                boost::asio::buffer(data_, max_length), sender_endpoint_,
                boost::bind(&receiver::handle_receive_from, this,
                boost::asio::placeholders::error,
                boost::asio::placeholders::bytes_transferred));
    }
}

 private:
    boost::asio::ip::udp::socket socket_;
    boost::asio::ip::udp::endpoint sender_endpoint_;
    enum { max_length = 1024 };
    char data_[max_length];
 };

int main(int argc, char* argv[])
{
   try
   {
      if (argc != 3)
      {
          std::cerr << "Usage: receiver <listen_address> <multicast_address>\n";
          std::cerr << "  For IPv4, try:\n";
          std::cerr << "    receiver 0.0.0.0 239.255.0.1\n";
          std::cerr << "  For IPv6, try:\n";
          std::cerr << "    receiver 0::0 ff31::8000:1234\n";
          return 1;
      }

      boost::asio::io_service io_service;
      receiver r(io_service,
              boost::asio::ip::address::from_string(argv[1]),
              boost::asio::ip::address::from_string(argv[2]));

     std::cout << "Starting listening... " <<  std::endl;
     io_service.run();
  }
  catch (std::exception& e)
  {
      std::cerr << "Exception: " << e.what() << "\n";
}

return 0;
}

问题是尽管Wireshark可以看到数据，但数据传递却没有被套接字看到。

我试图以root身份运行套接字，但没有取得多大成功。

有人知道这段代码是错的吗？

Answer 1

感谢您试图帮助我。事实上，网站上的例子很好。

我正在尝试捕获另一个应用程序发送的流量（查看wireshark屏幕捕获）。请注意，193.x.x.109不运行sender.cpp，而是发送其他数据。看看下面的小图：

193.x.x.109 ------------------------------Multicast data -------------> 231.11.1.5:6005
                                                 |
193.x.x.107 -(Running receiver.cpp)--------------|

这些数据是二进制的（不是字符串），如果这很重要的话。

tcpdump命令的等价物是：

tcpdump -i bond1 dst port 6005

Answer 2

我试过网站上的例子：

所有人看起来都很好。什么更让你烦恼？

具有boost c ++的多播接收器无法看到数据

2 个答案: