发送数据包给客户端给定remote_endpoint对象和套接字？ [英] sending packets to a client given the remote_endpoint object and the socket?

问题描述

是否有一种方法可以向客户端发送数据包，了解 remote_endpoint 其中 endpoint.address 和<$ c $ <> ：我添加了 async_write / code> free函数，但我还是不知道如何指定ip-address或端口为 socket _ 发送 data_ 到（客户端）。更改是升级异步服务器示例的第44-49行。

  #include< cstdlib> 
 #include< iostream> 
 #include< boost / bind.hpp> 
 #include< boost / asio.hpp> 
 
使用boost :: asio :: ip :: tcp; 
 
 class session 
 {
 public：
 session（boost :: asio :: io_service& io_service）
：socket_（io_service）
 {
} 
 
 tcp :: socket& socket（）
 {
 return socket_; 
} 
 
 void start（）
 {
 std :: cout<<start（）：<< std :: endl; 
 socket_.async_read_some（boost :: asio :: buffer（data_，max_length），
 boost :: bind（& session :: handle_read，this，
 boost :: asio :: placeholders :: error，
 boost :: asio :: placeholders :: bytes_transferred））; 
} 
 void read_handler（const boost :: system :: error_code& ec，std :: size_t bytes_transferred）; 
 
 
 private：
 void handle_read（const boost :: system :: error_code& error，
 size_t bytes_transferred）
 {
 std： ：cout<<handle read：bytes_transferred<< bytes_transferred<< std :: endl; 
 if（！error）
 {
 data_ = {'0'，'1'，'2'，'3'，'4'，'5'，'6' 7'，'8'，'9'}; 
 / * read_handler（error，bytes_transferred）; 
 boost :: asio :: async_write（socket_，boost :: asio :: buffer（data_，bytes_transferred），
 boost :: bind（& session :: handle_write，this，
 boost :: asio :: placeholders :: error））; * / 
 boost :: system :: error_code ec; 
 boost :: asio :: ip :: tcp :: endpoint endpoint = socket_.remote_endpoint（ec）; 
 std :: cout<<ip address：<< endpoint.address（）<< std :: endl; 
 std :: cout<<port：<< endpoint.port（）<< std :: endl; 
 //如何获取套接字发送数据到特定端口，ip-address例如。通过编辑改变ip地址和端口？ 
 async_write（socket_，boost :: asio :: buffer（data_，max_length），boost :: bind（& session :: writeHandler，this，boost :: asio :: placeholders :: error，boost :: asio :: placeholder :: bytes_transferred））; 
} 
 else 
 {
 delete this; 
} 
} 
 void writeHandler（const boost :: system :: error_code& errorCode，size_t bytesTransferred）
 {
 std :: cout< DEBUG> Transfered< bytesTransferred<< 字节到< socket_.remote_endpoint（）。address（）。to_string（）< std :: endl; 
} 
 void handle_write（const boost :: system :: error_code& error）
 {
 std :: cout<<handle write：< ：endl; 
 
 if（！error）
 {
 std :: cout<<before：<< data_<< std :: endl; 
 
 socket_.async_read_some（boost :: asio :: buffer（data_，max_length），
 boost :: bind（& session :: handle_read，this，
 boost :: asio :: placeholder :: error，
 boost :: asio :: placeholders :: bytes_transferred））; 
 
 std :: cout<<after：<< data_<< std :: endl; 
} 
 else 
 {
 delete this; 
} 
} 
 
 tcp :: socket socket_; 
 enum {max_length = 1024}; 
 char data_ [max_length]; 
}; 
 void session :: read_handler（const boost :: system :: error_code& ec，std :: size_t bytes_transferred）
 {
 std :: cout<< bytes_transferred<< std :: endl; 
} 
 
类服务器
 {
 public：
服务器（boost :: asio :: io_service& io_service，短端口）
： io_service_（io_service），
 acceptor_（io_service，tcp :: endpoint（tcp :: v4（），port））
 {
 start_accept 
} 
 
 
 private：
 void start_accept（）
 {
 session * new_session = new session（io_service_）; 
 acceptor_.async_accept（new_session-> socket（），
 boost :: bind（& server :: handle_accept，this，new_session，
 boost :: asio :: placeholders :: error ））; 
} 
 
 void handle_accept（session * new_session，
 const boost :: system :: error_code& error）
 {
 if（！error）
 {
 new_session-> start（）; 
} 
 else 
 {
 delete new_session; 
} 
 
 start_accept（）; 
} 
 
 boost :: asio :: io_service& io_service_; 
 tcp :: acceptor acceptor_; 
}; 
 
 int main（）
 {
 try 
 {
 boost :: asio :: io_service io_service; 
服务器s（io_service，4000）; 
 
 io_service.run（）; 
} 
 catch（std :: exception& e）
 {
 std :: cerr< Exception：<< e.what（）< \\\
; 
} 
 
 return 0; 
} 
  




解决方案

假设TCP套接字是你在文档中链接的，没有那是不可能的。您需要一个套接字对象来发送数据，而不仅仅是一个端点。使用 async_write（） free函数，它的许多重载之一，或任何套接字类方法发送数据。

Is there a way to send a packet to a client knowing the remote_endpoint object where endpoint.address and endpoint.port are used?

EDIT: I added the async_write free function but I still don't know how to specify the ip-address or the port for the socket_ to send data_ to (the client). The changes are lines 44-49 to the boost async server example.

#include <cstdlib>
#include <iostream>
#include <boost/bind.hpp>
#include <boost/asio.hpp>

using boost::asio::ip::tcp;

class session
{
public:
  session(boost::asio::io_service& io_service)
    : socket_(io_service)
  {
  }

  tcp::socket& socket()
  {
    return socket_;
  }

  void start()
  {
      std::cout<<"start(): "<<std::endl;
          socket_.async_read_some(boost::asio::buffer(data_, max_length),
          boost::bind(&session::handle_read, this,
          boost::asio::placeholders::error,
          boost::asio::placeholders::bytes_transferred));
  }
void read_handler(const boost::system::error_code& ec, std::size_t bytes_transferred);


private:
  void handle_read(const boost::system::error_code& error,
      size_t bytes_transferred)
  {
      std::cout<<"handle read: bytes_transferred"<<bytes_transferred<<std::endl;
    if (!error)
    {
          data_ = {'0','1','2','3','4','5','6','7','8','9'};
          /*read_handler(error, bytes_transferred);
          boost::asio::async_write(socket_,boost::asio::buffer(data_, bytes_transferred),
                boost::bind(&session::handle_write, this,
                            boost::asio::placeholders::error));*/
          boost::system::error_code ec;
          boost::asio::ip::tcp::endpoint endpoint = socket_.remote_endpoint(ec);
          std::cout<<"ip address: "<<endpoint.address()<<std::endl;
          std::cout<<"port: "<<endpoint.port()<<std::endl;
          //how to get the socket to send data to specific port, ip-address e.g. changing the ip-address and port by editing it?
          async_write(socket_, boost::asio::buffer(data_, max_length), boost::bind(&session::writeHandler, this, boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred));
    }
    else
    {
      delete this;
    }
  }
  void writeHandler(const boost::system::error_code& errorCode, size_t bytesTransferred)
  {
        std::cout << "DEBUG> Transfered " << bytesTransferred << " bytes to " << socket_.remote_endpoint().address().to_string() << std::endl;
  }
  void handle_write(const boost::system::error_code& error)
  {
      std::cout<<"handle write: "<<std::endl;

    if (!error)
    {
            std::cout<<"before: "<<data_<<std::endl;

            socket_.async_read_some(boost::asio::buffer(data_, max_length),
            boost::bind(&session::handle_read, this,
            boost::asio::placeholders::error,
            boost::asio::placeholders::bytes_transferred));

            std::cout<<"after: "<<data_<<std::endl;
    }
    else
    {
      delete this;
    }
  }

  tcp::socket socket_;
  enum { max_length = 1024 };
  char data_[max_length];
};
void session::read_handler(const boost::system::error_code& ec, std::size_t bytes_transferred)
{
      std::cout<<bytes_transferred<<std::endl;
}

class server
{
public:
  server(boost::asio::io_service& io_service, short port)
    : io_service_(io_service),
      acceptor_(io_service, tcp::endpoint(tcp::v4(), port))
  {
    start_accept();
  }


private:
  void start_accept()
  {
    session* new_session = new session(io_service_);
    acceptor_.async_accept(new_session->socket(),
        boost::bind(&server::handle_accept, this, new_session,
          boost::asio::placeholders::error));
  }

  void handle_accept(session* new_session,
      const boost::system::error_code& error)
  {
    if (!error)
    {
      new_session->start();
    }
    else
    {
      delete new_session;
    }

    start_accept();
  }

  boost::asio::io_service& io_service_;
  tcp::acceptor acceptor_;
};

int main()
{
  try
  {
    boost::asio::io_service io_service;
    server s(io_service, 4000);

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

  return 0;
}

解决方案

Assuming TCP sockets since that is what you linked to in the documentation, no that is not possible. You need a socket object to send data, not just an endpoint. Use the async_write() free function, one of its many overloads, or any of the socket class methods to send data.

这篇关于发送数据包给客户端给定remote_endpoint对象和套接字？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！