2 dns.h - dns library declarations based on firedns Copyright (C) 2002 Ian Gulliver
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22 #include "inspircd_config.h"
33 /** The DNS class allows fast nonblocking resolution of hostnames
34 * and ip addresses. It is based heavily upon firedns by Ian Gulliver.
36 class DNS : public Extensible
45 void dns_init_2(const char* dnsserver);
46 in_addr *dns_aton4(const char * const ipstring);
47 char *dns_ntoa4(const in_addr * const ip);
48 int dns_getip4(const char * const name);
49 int dns_getip4list(const char * const name);
50 int dns_getname4(const in_addr * const ip);
51 char *dns_getresult(const int fd);
52 in_addr *dns_aton4_s(const char * const ipstring, in_addr * const ip);
53 char *dns_ntoa4_s(const in_addr * const ip, char * const result);
54 char *dns_getresult_s(const int fd, char * const result);
55 in_addr *dns_aton4_r(const char * const ipstring);
56 char *dns_ntoa4_r(const in_addr * const ip);
57 char *dns_getresult_r(const int fd);
59 /** The default constructor uses dns addresses read from /etc/resolv.conf.
60 * Please note that it will re-read /etc/resolv.conf for each copy of the
61 * class you instantiate, causing disk access and slow lookups if you create
62 * a lot of them. Consider passing the constructor a server address as a parameter
66 /** This constructor accepts a dns server address. The address must be in dotted
67 * decimal form, e.g. 1.2.3.4.
69 DNS(const std::string &dnsserver);
70 /** The destructor frees all used structures.
73 /** This method will start the reverse lookup of an ip given in dotted decimal
74 * format, e.g. 1.2.3.4, and returns true if the lookup was successfully
77 bool ReverseLookup(const std::string &ip);
78 /** This method will start the forward lookup of a hostname, e.g. www.inspircd.org,
79 * and returns true if the lookup was successfully initiated.
81 bool ForwardLookup(const std::string &host);
82 /** Used by modules to perform a dns lookup but have the socket engine poll a module, instead of the dns object directly.
84 bool ForwardLookupWithFD(const std::string &host, int &fd);
85 /** This method will return true when the lookup is completed. It uses poll internally
86 * to determine the status of the socket.
89 /** This method will return true if the lookup's fd matches the one provided
91 bool HasResult(int fd);
92 /** This method returns the result of your query as a string, depending upon wether you
93 * called DNS::ReverseLookup() or DNS::ForwardLookup.
95 std::string GetResult();
96 std::string GetResultIP();
97 /** This method returns the file handle used by the dns query socket or zero if the
98 * query is invalid for some reason, e.g. the dns server not responding.
101 void SetNS(const std::string &dnsserver);
104 /** This is the handler function for multi-threaded DNS.
105 * It cannot be a class member as pthread will not let us
106 * create a thread whos handler function is a member of
109 void* dns_task(void* arg);