modified by ohneta
Dependents: HelloESP8266Interface_mine
Fork of DnsQuery by
Diff: DnsQuery.h
- Revision:
- 0:fff4b9055396
- Child:
- 1:5d978992a518
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/DnsQuery.h Tue Jul 14 20:48:12 2015 +0000 @@ -0,0 +1,90 @@ +/* Copyright (c) 2013 Henry Leinen (henry[dot]leinen [at] online [dot] de) + * + * Permission is hereby granted, free of charge, to any person obtaining a copy of this software + * and associated documentation files (the "Software"), to deal in the Software without restriction, + * including without limitation the rights to use, copy, modify, merge, publish, distribute, + * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in all copies or + * substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING + * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, + * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + */ +#ifndef __DNSQUERY_H__ +#define __DNSQUERY_H__ + +#include "Endpoint.h" +#include "UDPSocket.h" +typedef struct { + union { + struct { + char o1, o2, o3, o4; + }; + char o[4]; + } sin_addr; + operator char* () { return (char*)this; } + char* string_format() { + char ip[7]; + sprintf(ip,"%d.%d.%d.%d", this->sin_addr.o1, this->sin_addr.o2, this->sin_addr.o3, this->sin_addr.o4); + return ip; + } +} IPADDRESS_t; + +/** Class DnsQuery implements DNS over UDP functionality. + * Example as a typical use case : + * @code + * #include "mbed.h" + * #include "DnsQuery.h" + * + * void main(void) + * { + * IPADDRESS_t ipAddress; // will receive the ip address of the host + * IPADDRESS_t dnsIp = { 192, 168, 178, 1 }; // Ip Address of the DNS server + * + * DnsQuery dns(Wifi::getInstance(), &dnsIp); + * if (dns.gethostbyname("mbed.org", ipAddress)) { + * printf("Ip-Address of mbed.org is %d.%d.%d.%d\n", ipAddress.sin_addr.o1, ipAddress.sin_addr.o2, ipAddress.sin_addr.o3, ipAddress.sin_addr.o4); + * } else { + * printf("Unable to obtain IP-Address\n"); + * } + * } + * @endcode + */ +class DnsQuery +{ +public: + /** Constructor to instantiate a DnsQuery object. + * @param wifi : A valid pointer to a Wifi Object, which can be used to obtain a UDP socket object. + * @param dnsip : A valid pointer which holds the IPAddress of the DNS server to query. + */ + DnsQuery(IPADDRESS_t* dnsip); + + + /** Function gethostbyname implements the functionality to query a domain name server for an IP-Address of a given hostname. + * @param hostname : the hostname of interest as a string. + * @param ipaddress : a reference to a IPADDRESS_t object which will receive the resolved IP Address of the host in question. + * @returns true if successfull, or false otherwise. + */ + static bool gethostbyname(char* hostname, IPADDRESS_t &ipaddress); + /** Function gethostbyname implements the functionality to query a domain name server for an IP-Address of a given hostname. + * @param hostname : the hostname of interest as a string. + * @param ipaddress : a reference to a IPADDRESS_t object which will receive the resolved IP Address of the host in question. + * @returns true if successfull, or false otherwise. + */ + bool getIP(char* hostname, IPADDRESS_t &ipaddress); +protected: + bool resolve(char* resp, IPADDRESS_t &ipaddress); + bool parseRR(char *resp, int& c, IPADDRESS_t& adr ); + +protected: + Endpoint* _endpoint; + IPADDRESS_t _dnsip; + char* _string_ip; +}; + +#endif // __DNSQUERY_H__ \ No newline at end of file