Net::DNS::Resolver::Programmable(3pm)

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NAME

6       Net::DNS::Resolver::Programmable - programmable DNS resolver class for
7       offline emulation of DNS
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SYNOPSIS

10           use Net::DNS::Resolver::Programmable;
11           use Net::DNS::RR;
12
13           my $resolver = Net::DNS::Resolver::Programmable->new(
14               records         => {
15                   'example.com'     => [
16                       Net::DNS::RR->new('example.com.     NS  ns.example.org.'),
17                       Net::DNS::RR->new('example.com.     A   192.168.0.1')
18                   ],
19                   'ns.example.org'  => [
20                       Net::DNS::RR->new('ns.example.org.  A   192.168.1.1')
21                   ]
22               },
23
24               resolver_code   => sub {
25                   my ($domain, $rr_type, $class) = @_;
26                   ...
27                   return ($result, $aa, @rrs);
28               }
29           );
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DESCRIPTION

32       Net::DNS::Resolver::Programmable is a Net::DNS::Resolver descendant
33       class that allows a virtual DNS to be emulated instead of querying the
34       real DNS.  A set of static DNS records may be supplied, or arbitrary
35       code may be specified as a means for retrieving DNS records, or even
36       generating them on the fly.
37
38   Constructor
39       The following constructor is provided:
40
41       new(%options): returns Net::DNS::Resolver::Programmable
42           Creates a new programmed DNS resolver object.
43
44           %options is a list of key/value pairs representing any of the
45           following options:
46
47           records
48               A reference to a hash of arrays containing a static set of
49               Net::DNS::RR objects.  The hash entries must be indexed by
50               fully qualified domain names (lower-case, without any trailing
51               dots), and the entries themselves must be arrays of the RR
52               objects pertaining to these domain names.  For example:
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54                   records => {
55                       'example.com'     => [
56                           Net::DNS::RR->new('example.com.     NS  ns.example.org.'),
57                           Net::DNS::RR->new('example.com.     A   192.168.0.1')
58                       ],
59                       'www.example.com' => [
60                           Net::DNS::RR->new('www.example.com. A   192.168.0.2')
61                       ],
62                       'ns.example.org'  => [
63                           Net::DNS::RR->new('ns.example.org.  A   192.168.1.1')
64                       ]
65                   }
66
67               If this option is specified, the resolver retrieves requested
68               RRs from this data structure.
69
70           resolver_code
71               A code reference used as a call-back for dynamically retrieving
72               requested RRs.
73
74               The code must take the following query parameters as arguments:
75               the domain, RR type, and class.
76
77               It must return a list composed of: the response's RCODE (by
78               name, as returned by Net::DNS::Header->rcode), the "aa"
79               (authoritative answer) flag (boolean, use undef if you don't
80               care), and the Net::DNS::RR answer objects.  If an error string
81               is returned instead of a valid RCODE, a Net::DNS::Packet object
82               is not constructed but an error condition for the resolver is
83               signaled instead.
84
85               For example:
86
87                   resolver_code => sub {
88                       my ($domain, $rr_type, $class) = @_;
89                       ...
90                       return ($result, $aa, @rrs);
91                   }
92
93               If both this and the "records" option are specified, then
94               statically programmed records are used in addition to any that
95               are returned by the configured resolver code.
96
97           defnames
98           dnsrch
99           domain
100           searchlist
101           debug
102               These Net::DNS::Resolver options are also meaningful with
103               Net::DNS::Resolver::Programmable.  See Net::DNS::Resolver for
104               their descriptions.
105
106   Instance methods
107       The following instance methods of Net::DNS::Resolver are also supported
108       by Net::DNS::Resolver::Programmable:
109
110       search: returns Net::DNS::Packet
111       query: returns Net::DNS::Packet
112       send: returns Net::DNS::Packet
113           Performs an offline DNS query, using the statically programmed DNS
114           RRs and/or the configured dynamic resolver code.  See the "new"
115           constructor's "records" and "resolver_code" options.  See the
116           descriptions of search, query, and send for details about the
117           calling syntax of these methods.
118
119       print
120       string: returns string
121       searchlist: returns list of string
122       defnames: returns boolean
123       dnsrch: returns boolean
124       debug: returns boolean
125       errorstring: returns string
126       answerfrom: returns string
127       answersize: returns integer
128           See "METHODS" in Net::DNS::Resolver.
129
130       Currently the following methods of Net::DNS::Resolver are not
131       supported: axfr, axfr_start, axfr_next, nameservers, port, srcport,
132       srcaddr, bgsend, bgread, bgisready, tsig, retrans, retry, recurse,
133       usevc, tcp_timeout, udp_timeout, persistent_tcp, persistent_udp, igntc,
134       dnssec, cdflag, udppacketsize.  The effects of using these on
135       Net::DNS::Resolver::Programmable objects are undefined.
136

AUTHORS

144       David Precious (BIGPRESH) "<davidp@preshweb.co.uk>" took on
145       maintainership in July 2017
146
147       Original author Julian Mehnle "<julian@mehnle.net>"
148

ACKNOWLEDGEMENTS

150       Dick Franks (rwfranks)
151
152       (This section was added by BIGPRESH in July 2017, so currently omits
153       acknowledgements for those who contributed things in the past; I may
154       retrospectively add them in future.)
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158perl v5.36.0                      2023-01-20Net::DNS::Resolver::Programmable(3)

NAME

SYNOPSIS

DESCRIPTION

SEE ALSO

AUTHORS

ACKNOWLEDGEMENTS