Line data    Source code

       1             : /*
       2             :  * Copyright (c) 2013 Juniper Networks, Inc. All rights reserved.
       3             :  */
       4             : 
       5             : #ifndef __bind_resolver_h__
       6             : #define __bind_resolver_h__
       7             : 
       8             : #include <iostream>
       9             : #include <stdint.h>
      10             : #include <vector>
      11             : #include <boost/asio.hpp>
      12             : #include <boost/function.hpp>
      13             : 
      14             : class BindResolver {
      15             : public:
      16             :     typedef boost::function<void(uint8_t *, std::size_t)> Callback;
      17             :     static const int max_pkt_size = 1024;
      18             :     static const uint8_t max_dns_servers = 2;
      19             : 
      20             :     struct DnsServer {
      21          16 :         DnsServer (const std::string &ip, uint16_t port)
      22          16 :             : ip_(ip), port_(port) {}
      23             : 
      24             :         std::string ip_;
      25             :         uint16_t port_;
      26             :     };
      27             : 
      28             :     BindResolver(boost::asio::io_context &io,
      29             :                  const std::vector<DnsServer> &dns_servers,
      30             :                  uint16_t client_port, Callback cb, uint8_t dscp);
      31             :     virtual ~BindResolver();
      32             :     void SetupResolver(const DnsServer &server, uint8_t idx);
      33             :     bool DnsSend(uint8_t *pkt, unsigned int dns_srv_index, std::size_t len);
      34             :     bool DnsSend(uint8_t *pkt, boost::asio::ip::udp::endpoint ep,
      35             :                  std::size_t len);
      36             :     void SetDscpValue(uint8_t val);
      37             :     uint8_t GetDscpValue();
      38             : 
      39             :     static void Init(boost::asio::io_context &io,
      40             :                      const std::vector<DnsServer> &dns_servers,
      41             :                      uint16_t client_port, Callback cb, uint8_t dscp);
      42             :     static void Shutdown();
      43           0 :     static BindResolver *Resolver() { return resolver_; }
      44             : 
      45             : private:
      46             :     void SetDscpSocketOption();
      47             :     void AsyncRead();
      48             :     void DnsSendHandler(const boost::system::error_code &error,
      49             :                         std::size_t length, uint8_t *pkt);
      50             :     void DnsRcvHandler(const boost::system::error_code &error,
      51             :                        std::size_t length);
      52             : 
      53             :     uint8_t *pkt_buf_;
      54             :     Callback cb_;
      55             :     boost::asio::ip::udp::socket sock_;
      56             :     std::vector<boost::asio::ip::udp::endpoint *> dns_ep_;
      57             :     uint8_t dscp_value_;
      58             :     static BindResolver *resolver_;
      59             : 
      60             :     DISALLOW_COPY_AND_ASSIGN(BindResolver);
      61             : };
      62             : 
      63             : #endif // __bind_resolver_h__