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/*
dns.h - dns library declarations based on firedns Copyright (C) 2002 Ian Gulliver
This program is free software; you can redistribute it and/or modify
it under the terms of version 2 of the GNU General Public License as
published by the Free Software Foundation.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef _DNS_H
#define _DNS_H
#include <string>
#include "socket.h"
struct dns_ip4list {
in_addr ip;
dns_ip4list *next;
};
/** The DNS class allows fast nonblocking resolution of hostnames
* and ip addresses. It is based heavily upon firedns by Ian Gulliver.
*/
class DNS
{
private:
in_addr *binip;
char* result;
char localbuf[1024];
int t;
void dns_init();
int myfd;
void dns_init_2(const char* dnsserver);
in_addr *dns_aton4(const char * const ipstring);
char *dns_ntoa4(const in_addr * const ip);
int dns_getip4(const char * const name);
int dns_getip4list(const char * const name);
int dns_getname4(const in_addr * const ip);
char *dns_getresult(const int fd);
in_addr *dns_aton4_s(const char * const ipstring, in_addr * const ip);
char *dns_ntoa4_s(const in_addr * const ip, char * const result);
char *dns_getresult_s(const int fd, char * const result);
in_addr *dns_aton4_r(const char * const ipstring);
char *dns_ntoa4_r(const in_addr * const ip);
char *dns_getresult_r(const int fd);
public:
/** The default constructor uses dns addresses read from /etc/resolv.conf.
* Please note that it will re-read /etc/resolv.conf for each copy of the
* class you instantiate, causing disk access and slow lookups if you create
* a lot of them. Consider passing the constructor a server address as a parameter
* instead.
*/
DNS();
/** This constructor accepts a dns server address. The address must be in dotted
* decimal form, e.g. 1.2.3.4.
*/
DNS(const std::string &dnsserver);
/** The destructor frees all used structures.
*/
~DNS();
/** This method will start the reverse lookup of an ip given in dotted decimal
* format, e.g. 1.2.3.4, and returns true if the lookup was successfully
* initiated.
*/
bool ReverseLookup(const std::string &ip);
/** This method will start the forward lookup of a hostname, e.g. www.inspircd.org,
* and returns true if the lookup was successfully initiated.
*/
bool ForwardLookup(const std::string &host);
/** Used by modules to perform a dns lookup but have the socket engine poll a module, instead of the dns object directly.
*/
bool ForwardLookupWithFD(const std::string &host, int &fd);
/** This method will return true when the lookup is completed. It uses poll internally
* to determine the status of the socket.
*/
bool HasResult();
/** This method will return true if the lookup's fd matches the one provided
*/
bool HasResult(int fd);
/** This method returns the result of your query as a string, depending upon wether you
* called DNS::ReverseLookup() or DNS::ForwardLookup.
*/
std::string GetResult();
std::string GetResultIP();
/** This method returns the file handle used by the dns query socket or zero if the
* query is invalid for some reason, e.g. the dns server not responding.
*/
int GetFD();
void SetNS(const std::string &dnsserver);
};
/** This is the handler function for multi-threaded DNS.
* It cannot be a class member as pthread will not let us
* create a thread whos handler function is a member of
* a class (ugh).
*/
void* dns_task(void* arg);
#endif
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