DNSClient.h

00001 // DNSClient.h 2013/4/5
00002 #pragma once
00003 
00004 #include "UDPSocket.h"
00005 
00006 //#define DBG_DNS 1
00007  
00008 class DNSClient {
00009 public:
00010     DNSClient();
00011     DNSClient(NetworkStack *ns, const char* hostname = NULL);
00012     DNSClient(NetworkStack *ns, SocketAddress* pHost);
00013     
00014     int setup(NetworkStack *ns);
00015 
00016     virtual ~DNSClient();
00017     bool lookup(const char* hostname);
00018     bool set_server(const char* serverip, int port=53);
00019     uint32_t get_ip() {return m_ip;}
00020     const char* get_ip_address() {return m_ipaddr;}
00021     
00022 protected:
00023     void poll();
00024     void callback();
00025     int response(uint8_t buf[], int size);
00026     int query(uint8_t buf[], int size, const char* hostname);
00027     void resolve(const char* hostname);
00028     uint8_t m_id[2];
00029     Timer m_interval;
00030     int m_retry;
00031     const char* m_hostname;
00032 
00033 private:
00034     enum MyNetDnsState
00035     {
00036         MYNETDNS_START,
00037         MYNETDNS_PROCESSING, //Req has not completed
00038         MYNETDNS_NOTFOUND,
00039         MYNETDNS_ERROR,
00040         MYNETDNS_OK
00041     };
00042     MyNetDnsState m_state;
00043     UDPSocket *m_udp;
00044     NetworkStack *m_ns;
00045 
00046     uint32_t m_ip;
00047     char m_ipaddr[24];
00048 };