如何使用Boost在C++中创建代理服务器

Question

我正在制作一个Web应用程序模糊器,对于我的代理服务器,我正在使用由一个名叫Alex Ott的人开发的开源代码(现在).我注意到,当我从一些网站发出请求时,我们确实想用C++编写自己的代理,但我完全不知道从哪里开始.有人可以向我解释一下吗？

最终目标是能够捕获并将通过代理发出的每个请求写入文件,我已经在做了,但我现在拥有的代理服务器并没有捕获所有这些请求,我知道在那里.

编辑:由于问题不清楚,这里是:我想知道使用Boost扩展库用C++编写的代理服务器的代码是什么.过去四个月的同样问题.

Answer 1

好吧,这是一个让您入门的功能性示例.它在两个连接之间转发.请注意,此简单示例不适用于Web浏览器,因为客户端将尝试进行多个连接,此示例仅侦听一个连接.使用它作为(非常简单)的基础,你应该能够取得一些进展.

有趣的东西发生在handle_read,这是收到数据时执行的回调.此函数在套接字之间转发数据.请注意,当我们最初为"本地"和"远程"连接调用它时,我们通过套接字的顺序被反转(read_from和write_to).

#include <iostream>
using namespace std;

#include <boost/asio.hpp>
#include <boost/lexical_cast.hpp>
#include <boost/thread.hpp>
#include <boost/bind.hpp>

boost::asio::io_service& io_service()
{
   static boost::asio::io_service svc;
   return svc;
}

char local_data[1024] = {0};
char remote_data[1024] = {0};

void handle_read(
   boost::asio::ip::tcp::socket& read_from,
   boost::asio::ip::tcp::socket& write_to,
   char* read_buffer,
   size_t bytes,
   const boost::system::error_code& e)
{
   // this function is called whenever data is received

   // for debugging purposes, show the data in the console window
   // or write to file, or whatever...
   std::string data(read_buffer, read_buffer + bytes);    
   std::cout << data << "\n";

   // forward the received data on to "the other side"    
   write_to.send(
      boost::asio::buffer(read_buffer, bytes));

   // read more data from "this side"
   read_from.async_read_some(
      boost::asio::buffer(read_buffer, 1024),
      boost::bind(handle_read, boost::ref(read_from), boost::ref(write_to), read_buffer, boost::asio::placeholders::bytes_transferred, boost::asio::placeholders::error));
}

int main(int argc, char** argv)
{
   if(argc == 5)
   {
      boost::asio::io_service::work w(io_service());

      boost::thread t(boost::bind(&boost::asio::io_service::run, (&io_service())));

      // extract the connection information from the command line
      boost::asio::ip::address local_address = boost::asio::ip::address::from_string(argv[1]);
      uint16_t local_port = boost::lexical_cast<uint16_t>(argv[2]);
      boost::asio::ip::address remote_address = boost::asio::ip::address::from_string(argv[3]);
      uint16_t remote_port = boost::lexical_cast<uint16_t>(argv[4]);

      boost::asio::ip::tcp::endpoint local_ep(local_address, local_port);
      boost::asio::ip::tcp::endpoint remote_ep(remote_address, remote_port);

      // start listening on the "local" socket -- note this does not
      // have to be local, you could in theory forward through a remote device
      // it's called "local" in the logical sense    
      boost::asio::ip::tcp::acceptor listen(io_service(), local_ep);
      boost::asio::ip::tcp::socket local_socket(io_service());
      listen.accept(local_socket);

      // open the remote connection
      boost::asio::ip::tcp::socket remote_socket(io_service());
      remote_socket.open(remote_ep.protocol());
      remote_socket.connect(remote_ep);

      // start listening for data on the "local" connection
      local_socket.async_receive(
         boost::asio::buffer(local_data, 1024),
         boost::bind(handle_read, boost::ref(local_socket), boost::ref(remote_socket), local_data, boost::asio::placeholders::bytes_transferred, boost::asio::placeholders::error));

      // also listen for data on the "remote" connection
      remote_socket.async_receive(
         boost::asio::buffer(remote_data, 1024),
         boost::bind(handle_read, boost::ref(remote_socket), boost::ref(local_socket), remote_data, boost::asio::placeholders::bytes_transferred, boost::asio::placeholders::error));

      t.join();
   }
   else
   {
      cout << "proxy <local ip> <port> <remote ip> <port>\n";
   }

   return 0;
}