… | |
… | |
2 | |
2 | |
3 | AnyEvent::DNS - fully asynchronous DNS resolution |
3 | AnyEvent::DNS - fully asynchronous DNS resolution |
4 | |
4 | |
5 | =head1 SYNOPSIS |
5 | =head1 SYNOPSIS |
6 | |
6 | |
7 | use AnyEvent::DNS; |
7 | use AnyEvent::DNS; |
8 | |
8 | |
9 | my $cv = AnyEvent->condvar; |
9 | my $cv = AnyEvent->condvar; |
10 | AnyEvent::DNS::a "www.google.de", $cv; |
10 | AnyEvent::DNS::a "www.google.de", $cv; |
11 | # ... later |
11 | # ... later |
12 | my @addrs = $cv->recv; |
12 | my @addrs = $cv->recv; |
13 | |
13 | |
14 | =head1 DESCRIPTION |
14 | =head1 DESCRIPTION |
15 | |
15 | |
16 | This module offers both a number of DNS convenience functions as well |
16 | This module offers both a number of DNS convenience functions as well |
17 | as a fully asynchronous and high-performance pure-perl stub resolver. |
17 | as a fully asynchronous and high-performance pure-perl stub resolver. |
18 | |
18 | |
19 | The stub resolver supports DNS over UDP, optional EDNS0 support for up to |
19 | The stub resolver supports DNS over IPv4 and IPv6, UDP and TCP, optional |
20 | 4kiB datagrams and automatically falls back to virtual circuit mode for |
20 | EDNS0 support for up to 4kiB datagrams and automatically falls back to |
21 | large responses. |
21 | virtual circuit mode for large responses. |
22 | |
22 | |
23 | =head2 CONVENIENCE FUNCTIONS |
23 | =head2 CONVENIENCE FUNCTIONS |
24 | |
24 | |
25 | =over 4 |
25 | =over 4 |
26 | |
26 | |
… | |
… | |
35 | |
35 | |
36 | use AnyEvent (); |
36 | use AnyEvent (); |
37 | use AnyEvent::Handle (); |
37 | use AnyEvent::Handle (); |
38 | use AnyEvent::Util qw(AF_INET6); |
38 | use AnyEvent::Util qw(AF_INET6); |
39 | |
39 | |
40 | our $VERSION = '1.0'; |
40 | our $VERSION = 4.352; |
41 | |
41 | |
42 | our @DNS_FALLBACK = (v208.67.220.220, v208.67.222.222); |
42 | our @DNS_FALLBACK = (v208.67.220.220, v208.67.222.222); |
43 | |
43 | |
44 | =item AnyEvent::DNS::a $domain, $cb->(@addrs) |
44 | =item AnyEvent::DNS::a $domain, $cb->(@addrs) |
45 | |
45 | |
… | |
… | |
65 | =item AnyEvent::DNS::srv $service, $proto, $domain, $cb->(@srv_rr) |
65 | =item AnyEvent::DNS::srv $service, $proto, $domain, $cb->(@srv_rr) |
66 | |
66 | |
67 | Tries to resolve the given service, protocol and domain name into a list |
67 | Tries to resolve the given service, protocol and domain name into a list |
68 | of service records. |
68 | of service records. |
69 | |
69 | |
70 | Each srv_rr is an array reference with the following contents: |
70 | Each C<$srv_rr> is an array reference with the following contents: |
71 | C<[$priority, $weight, $transport, $target]>. |
71 | C<[$priority, $weight, $transport, $target]>. |
72 | |
72 | |
73 | They will be sorted with lowest priority, highest weight first (TODO: |
73 | They will be sorted with lowest priority first, then randomly |
74 | should use the RFC algorithm to reorder same-priority records for weight). |
74 | distributed by weight as per RFC 2782. |
75 | |
75 | |
76 | Example: |
76 | Example: |
77 | |
77 | |
78 | AnyEvent::DNS::srv "sip", "udp", "schmorp.de", sub { ... |
78 | AnyEvent::DNS::srv "sip", "udp", "schmorp.de", sub { ... |
79 | # @_ = ( [10, 10, 5060, "sip1.schmorp.de" ] ) |
79 | # @_ = ( [10, 10, 5060, "sip1.schmorp.de" ] ) |
80 | |
80 | |
81 | =item AnyEvent::DNS::ptr $ipv4_or_6, $cb->(@hostnames) |
81 | =item AnyEvent::DNS::ptr $domain, $cb->(@hostnames) |
|
|
82 | |
|
|
83 | Tries to make a PTR lookup on the given domain. See C<reverse_lookup> |
|
|
84 | and C<reverse_verify> if you want to resolve an IP address to a hostname |
|
|
85 | instead. |
|
|
86 | |
|
|
87 | =item AnyEvent::DNS::any $domain, $cb->(@rrs) |
|
|
88 | |
|
|
89 | Tries to resolve the given domain and passes all resource records found to |
|
|
90 | the callback. |
|
|
91 | |
|
|
92 | =item AnyEvent::DNS::reverse_lookup $ipv4_or_6, $cb->(@hostnames) |
82 | |
93 | |
83 | Tries to reverse-resolve the given IPv4 or IPv6 address (in textual form) |
94 | Tries to reverse-resolve the given IPv4 or IPv6 address (in textual form) |
84 | into it's hostname(s). |
95 | into it's hostname(s). Handles V4MAPPED and V4COMPAT IPv6 addresses |
|
|
96 | transparently. |
|
|
97 | |
|
|
98 | =item AnyEvent::DNS::reverse_verify $ipv4_or_6, $cb->(@hostnames) |
|
|
99 | |
|
|
100 | The same as C<reverse_lookup>, but does forward-lookups to verify that |
|
|
101 | the resolved hostnames indeed point to the address, which makes spoofing |
|
|
102 | harder. |
|
|
103 | |
|
|
104 | If you want to resolve an address into a hostname, this is the preferred |
|
|
105 | method: The DNS records could still change, but at least this function |
|
|
106 | verified that the hostname, at one point in the past, pointed at the IP |
|
|
107 | address you originally resolved. |
85 | |
108 | |
86 | Example: |
109 | Example: |
87 | |
110 | |
88 | AnyEvent::DNS::ptr "2001:500:2f::f", sub { print shift }; |
111 | AnyEvent::DNS::ptr "2001:500:2f::f", sub { print shift }; |
89 | # => f.root-servers.net |
112 | # => f.root-servers.net |
90 | |
|
|
91 | =item AnyEvent::DNS::any $domain, $cb->(@rrs) |
|
|
92 | |
|
|
93 | Tries to resolve the given domain and passes all resource records found to |
|
|
94 | the callback. |
|
|
95 | |
113 | |
96 | =cut |
114 | =cut |
97 | |
115 | |
98 | sub MAX_PKT() { 4096 } # max packet size we advertise and accept |
116 | sub MAX_PKT() { 4096 } # max packet size we advertise and accept |
99 | |
117 | |
… | |
… | |
144 | sub srv($$$$) { |
162 | sub srv($$$$) { |
145 | my ($service, $proto, $domain, $cb) = @_; |
163 | my ($service, $proto, $domain, $cb) = @_; |
146 | |
164 | |
147 | # todo, ask for any and check glue records |
165 | # todo, ask for any and check glue records |
148 | resolver->resolve ("_$service._$proto.$domain" => "srv", sub { |
166 | resolver->resolve ("_$service._$proto.$domain" => "srv", sub { |
149 | $cb->(map [@$_[3,4,5,6]], sort { $a->[3] <=> $b->[3] || $b->[4] <=> $a->[4] } @_); |
167 | my @res; |
|
|
168 | |
|
|
169 | # classify by priority |
|
|
170 | my %pri; |
|
|
171 | push @{ $pri{$_->[3]} }, [ @$_[3,4,5,6] ] |
|
|
172 | for @_; |
|
|
173 | |
|
|
174 | # order by priority |
|
|
175 | for my $pri (sort { $a <=> $b } keys %pri) { |
|
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176 | # order by weight |
|
|
177 | my @rr = sort { $a->[1] <=> $b->[1] } @{ delete $pri{$pri} }; |
|
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178 | |
|
|
179 | my $sum; $sum += $_->[1] for @rr; |
|
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180 | |
|
|
181 | while (@rr) { |
|
|
182 | my $w = int rand $sum + 1; |
|
|
183 | for (0 .. $#rr) { |
|
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184 | if (($w -= $rr[$_][1]) <= 0) { |
|
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185 | $sum -= $rr[$_][1]; |
|
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186 | push @res, splice @rr, $_, 1, (); |
|
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187 | last; |
|
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188 | } |
|
|
189 | } |
|
|
190 | } |
|
|
191 | } |
|
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192 | |
|
|
193 | $cb->(@res); |
150 | }); |
194 | }); |
151 | } |
195 | } |
152 | |
196 | |
153 | sub ptr($$) { |
197 | sub ptr($$) { |
|
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198 | my ($domain, $cb) = @_; |
|
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199 | |
|
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200 | resolver->resolve ($domain => "ptr", sub { |
|
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201 | $cb->(map $_->[3], @_); |
|
|
202 | }); |
|
|
203 | } |
|
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204 | |
|
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205 | sub any($$) { |
|
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206 | my ($domain, $cb) = @_; |
|
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207 | |
|
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208 | resolver->resolve ($domain => "*", $cb); |
|
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209 | } |
|
|
210 | |
|
|
211 | # convert textual ip address into reverse lookup form |
|
|
212 | sub _munge_ptr($) { |
|
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213 | my $ipn = $_[0] |
|
|
214 | or return; |
|
|
215 | |
|
|
216 | my $ptr; |
|
|
217 | |
|
|
218 | my $af = AnyEvent::Socket::address_family ($ipn); |
|
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219 | |
|
|
220 | if ($af == AF_INET6) { |
|
|
221 | $ipn = substr $ipn, 0, 16; # anticipate future expansion |
|
|
222 | |
|
|
223 | # handle v4mapped and v4compat |
|
|
224 | if ($ipn =~ s/^\x00{10}(?:\xff\xff|\x00\x00)//) { |
|
|
225 | $af = AF_INET; |
|
|
226 | } else { |
|
|
227 | $ptr = join ".", (reverse split //, unpack "H32", $ipn), "ip6.arpa."; |
|
|
228 | } |
|
|
229 | } |
|
|
230 | |
|
|
231 | if ($af == AF_INET) { |
|
|
232 | $ptr = join ".", (reverse unpack "C4", $ipn), "in-addr.arpa."; |
|
|
233 | } |
|
|
234 | |
|
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235 | $ptr |
|
|
236 | } |
|
|
237 | |
|
|
238 | sub reverse_lookup($$) { |
154 | my ($ip, $cb) = @_; |
239 | my ($ip, $cb) = @_; |
155 | |
240 | |
156 | $ip = AnyEvent::Socket::parse_address ($ip) |
241 | $ip = _munge_ptr AnyEvent::Socket::parse_address ($ip) |
157 | or return $cb->(); |
242 | or return $cb->(); |
158 | |
|
|
159 | my $af = AnyEvent::Socket::address_family ($ip); |
|
|
160 | |
|
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161 | if ($af == AF_INET) { |
|
|
162 | $ip = join ".", (reverse split /\./, $ip), "in-addr.arpa."; |
|
|
163 | } elsif ($af == AF_INET6) { |
|
|
164 | $ip = join ".", (reverse split //, unpack "H*", $ip), "ip6.arpa."; |
|
|
165 | } else { |
|
|
166 | return $cb->(); |
|
|
167 | } |
|
|
168 | |
243 | |
169 | resolver->resolve ($ip => "ptr", sub { |
244 | resolver->resolve ($ip => "ptr", sub { |
170 | $cb->(map $_->[3], @_); |
245 | $cb->(map $_->[3], @_); |
171 | }); |
246 | }); |
172 | } |
247 | } |
173 | |
248 | |
174 | sub any($$) { |
249 | sub reverse_verify($$) { |
175 | my ($domain, $cb) = @_; |
250 | my ($ip, $cb) = @_; |
|
|
251 | |
|
|
252 | my $ipn = AnyEvent::Socket::parse_address ($ip) |
|
|
253 | or return $cb->(); |
176 | |
254 | |
177 | resolver->resolve ($domain => "*", $cb); |
255 | my $af = AnyEvent::Socket::address_family ($ipn); |
|
|
256 | |
|
|
257 | my @res; |
|
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258 | my $cnt; |
|
|
259 | |
|
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260 | my $ptr = _munge_ptr $ipn |
|
|
261 | or return $cb->(); |
|
|
262 | |
|
|
263 | $ip = AnyEvent::Socket::format_address ($ipn); # normalise into the same form |
|
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264 | |
|
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265 | ptr $ptr, sub { |
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266 | for my $name (@_) { |
|
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267 | ++$cnt; |
|
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268 | |
|
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269 | # () around AF_INET to work around bug in 5.8 |
|
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270 | resolver->resolve ("$name." => ($af == (AF_INET) ? "a" : "aaaa"), sub { |
|
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271 | for (@_) { |
|
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272 | push @res, $name |
|
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273 | if $_->[3] eq $ip; |
|
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274 | } |
|
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275 | $cb->(@res) unless --$cnt; |
|
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276 | }); |
|
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277 | } |
|
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278 | |
|
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279 | $cb->() unless $cnt; |
|
|
280 | }; |
178 | } |
281 | } |
179 | |
282 | |
180 | ################################################################################# |
283 | ################################################################################# |
181 | |
284 | |
182 | =back |
285 | =back |
… | |
… | |
248 | minfo => 14, |
351 | minfo => 14, |
249 | mx => 15, |
352 | mx => 15, |
250 | txt => 16, |
353 | txt => 16, |
251 | aaaa => 28, |
354 | aaaa => 28, |
252 | srv => 33, |
355 | srv => 33, |
|
|
356 | naptr => 35, # rfc2915 |
253 | opt => 41, |
357 | opt => 41, |
254 | spf => 99, |
358 | spf => 99, |
255 | tkey => 249, |
359 | tkey => 249, |
256 | tsig => 250, |
360 | tsig => 250, |
257 | ixfr => 251, |
361 | ixfr => 251, |
… | |
… | |
270 | "*" => 255, |
374 | "*" => 255, |
271 | ); |
375 | ); |
272 | |
376 | |
273 | our %class_str = reverse %class_id; |
377 | our %class_str = reverse %class_id; |
274 | |
378 | |
275 | # names MUST have a trailing dot |
|
|
276 | sub _enc_name($) { |
379 | sub _enc_name($) { |
277 | pack "(C/a*)*", (split /\./, shift), "" |
380 | pack "(C/a*)*", (split /\./, shift), "" |
278 | } |
381 | } |
279 | |
382 | |
280 | sub _enc_qd() { |
383 | sub _enc_qd() { |
… | |
… | |
287 | die "encoding of resource records is not supported"; |
390 | die "encoding of resource records is not supported"; |
288 | } |
391 | } |
289 | |
392 | |
290 | =item $pkt = AnyEvent::DNS::dns_pack $dns |
393 | =item $pkt = AnyEvent::DNS::dns_pack $dns |
291 | |
394 | |
292 | Packs a perl data structure into a DNS packet. Reading RFC1034 is strongly |
395 | Packs a perl data structure into a DNS packet. Reading RFC 1035 is strongly |
293 | recommended, then everything will be totally clear. Or maybe not. |
396 | recommended, then everything will be totally clear. Or maybe not. |
294 | |
397 | |
295 | Resource records are not yet encodable. |
398 | Resource records are not yet encodable. |
296 | |
399 | |
297 | Examples: |
400 | Examples: |
298 | |
401 | |
299 | # very simple request, using lots of default values: |
402 | # very simple request, using lots of default values: |
300 | { rd => 1, qd => [ [ "host.domain", "a"] ] } |
403 | { rd => 1, qd => [ [ "host.domain", "a"] ] } |
301 | |
404 | |
302 | # more complex example, showing how flags etc. are named: |
405 | # more complex example, showing how flags etc. are named: |
303 | |
406 | |
304 | { |
407 | { |
305 | id => 10000, |
408 | id => 10000, |
306 | op => "query", |
409 | op => "query", |
307 | rc => "nxdomain", |
410 | rc => "nxdomain", |
308 | |
411 | |
309 | # flags |
412 | # flags |
310 | qr => 1, |
413 | qr => 1, |
311 | aa => 0, |
414 | aa => 0, |
312 | tc => 0, |
415 | tc => 0, |
313 | rd => 0, |
416 | rd => 0, |
314 | ra => 0, |
417 | ra => 0, |
315 | ad => 0, |
418 | ad => 0, |
316 | cd => 0, |
419 | cd => 0, |
317 | |
420 | |
318 | qd => [@rr], # query section |
421 | qd => [@rr], # query section |
319 | an => [@rr], # answer section |
422 | an => [@rr], # answer section |
320 | ns => [@rr], # authority section |
423 | ns => [@rr], # authority section |
321 | ar => [@rr], # additional records section |
424 | ar => [@rr], # additional records section |
322 | } |
425 | } |
323 | |
426 | |
324 | =cut |
427 | =cut |
325 | |
428 | |
326 | sub dns_pack($) { |
429 | sub dns_pack($) { |
327 | my ($req) = @_; |
430 | my ($req) = @_; |
… | |
… | |
340 | + $rcode_id{$req->{rc}} * 0x0001, |
443 | + $rcode_id{$req->{rc}} * 0x0001, |
341 | |
444 | |
342 | scalar @{ $req->{qd} || [] }, |
445 | scalar @{ $req->{qd} || [] }, |
343 | scalar @{ $req->{an} || [] }, |
446 | scalar @{ $req->{an} || [] }, |
344 | scalar @{ $req->{ns} || [] }, |
447 | scalar @{ $req->{ns} || [] }, |
345 | $EDNS0 + scalar @{ $req->{ar} || [] }, # include EDNS0 option here |
448 | $EDNS0 + scalar @{ $req->{ar} || [] }, # EDNS0 option included here |
346 | |
449 | |
347 | (join "", map _enc_qd, @{ $req->{qd} || [] }), |
450 | (join "", map _enc_qd, @{ $req->{qd} || [] }), |
348 | (join "", map _enc_rr, @{ $req->{an} || [] }), |
451 | (join "", map _enc_rr, @{ $req->{an} || [] }), |
349 | (join "", map _enc_rr, @{ $req->{ns} || [] }), |
452 | (join "", map _enc_rr, @{ $req->{ns} || [] }), |
350 | (join "", map _enc_rr, @{ $req->{ar} || [] }), |
453 | (join "", map _enc_rr, @{ $req->{ar} || [] }), |
351 | |
454 | |
352 | ($EDNS0 ? pack "C nnNn", 0, 41, MAX_PKT, 0, 0 : "") # EDNS0, 4kiB udp payload size |
455 | ($EDNS0 ? pack "C nnNn", 0, 41, MAX_PKT, 0, 0 : "") # EDNS0 option |
353 | } |
456 | } |
354 | |
457 | |
355 | our $ofs; |
458 | our $ofs; |
356 | our $pkt; |
459 | our $pkt; |
357 | |
460 | |
… | |
… | |
402 | 13 => sub { unpack "C/a* C/a*", $_ }, # hinfo |
505 | 13 => sub { unpack "C/a* C/a*", $_ }, # hinfo |
403 | 15 => sub { local $ofs = $ofs + 2 - length; ((unpack "n", $_), _dec_name) }, # mx |
506 | 15 => sub { local $ofs = $ofs + 2 - length; ((unpack "n", $_), _dec_name) }, # mx |
404 | 16 => sub { unpack "(C/a*)*", $_ }, # txt |
507 | 16 => sub { unpack "(C/a*)*", $_ }, # txt |
405 | 28 => sub { AnyEvent::Socket::format_address ($_) }, # aaaa |
508 | 28 => sub { AnyEvent::Socket::format_address ($_) }, # aaaa |
406 | 33 => sub { local $ofs = $ofs + 6 - length; ((unpack "nnn", $_), _dec_name) }, # srv |
509 | 33 => sub { local $ofs = $ofs + 6 - length; ((unpack "nnn", $_), _dec_name) }, # srv |
|
|
510 | 35 => sub { # naptr |
|
|
511 | # requires perl 5.10, sorry |
|
|
512 | my ($order, $preference, $flags, $service, $regexp, $offset) = unpack "nn C/a* C/a* C/a* .", $_; |
|
|
513 | local $ofs = $ofs + $offset - length; |
|
|
514 | ($order, $preference, $flags, $service, $regexp, _dec_name) |
|
|
515 | }, |
407 | 99 => sub { unpack "(C/a*)*", $_ }, # spf |
516 | 99 => sub { unpack "(C/a*)*", $_ }, # spf |
408 | ); |
517 | ); |
409 | |
518 | |
410 | sub _dec_rr { |
519 | sub _dec_rr { |
411 | my $name = _dec_name; |
520 | my $name = _dec_name; |
… | |
… | |
425 | |
534 | |
426 | Unpacks a DNS packet into a perl data structure. |
535 | Unpacks a DNS packet into a perl data structure. |
427 | |
536 | |
428 | Examples: |
537 | Examples: |
429 | |
538 | |
430 | # an unsuccessful reply |
539 | # an unsuccessful reply |
431 | { |
540 | { |
432 | 'qd' => [ |
541 | 'qd' => [ |
433 | [ 'ruth.plan9.de.mach.uni-karlsruhe.de', '*', 'in' ] |
542 | [ 'ruth.plan9.de.mach.uni-karlsruhe.de', '*', 'in' ] |
434 | ], |
543 | ], |
435 | 'rc' => 'nxdomain', |
544 | 'rc' => 'nxdomain', |
436 | 'ar' => [], |
545 | 'ar' => [], |
437 | 'ns' => [ |
546 | 'ns' => [ |
438 | [ |
547 | [ |
439 | 'uni-karlsruhe.de', |
548 | 'uni-karlsruhe.de', |
440 | 'soa', |
549 | 'soa', |
441 | 'in', |
550 | 'in', |
442 | 'netserv.rz.uni-karlsruhe.de', |
551 | 'netserv.rz.uni-karlsruhe.de', |
443 | 'hostmaster.rz.uni-karlsruhe.de', |
552 | 'hostmaster.rz.uni-karlsruhe.de', |
444 | 2008052201, 10800, 1800, 2592000, 86400 |
553 | 2008052201, 10800, 1800, 2592000, 86400 |
445 | ] |
554 | ] |
446 | ], |
555 | ], |
447 | 'tc' => '', |
556 | 'tc' => '', |
448 | 'ra' => 1, |
557 | 'ra' => 1, |
449 | 'qr' => 1, |
558 | 'qr' => 1, |
450 | 'id' => 45915, |
559 | 'id' => 45915, |
451 | 'aa' => '', |
560 | 'aa' => '', |
452 | 'an' => [], |
561 | 'an' => [], |
453 | 'rd' => 1, |
562 | 'rd' => 1, |
454 | 'op' => 'query' |
563 | 'op' => 'query' |
455 | } |
564 | } |
456 | |
565 | |
457 | # a successful reply |
566 | # a successful reply |
458 | |
567 | |
459 | { |
568 | { |
460 | 'qd' => [ [ 'www.google.de', 'a', 'in' ] ], |
569 | 'qd' => [ [ 'www.google.de', 'a', 'in' ] ], |
461 | 'rc' => 0, |
570 | 'rc' => 0, |
462 | 'ar' => [ |
571 | 'ar' => [ |
463 | [ 'a.l.google.com', 'a', 'in', '209.85.139.9' ], |
572 | [ 'a.l.google.com', 'a', 'in', '209.85.139.9' ], |
464 | [ 'b.l.google.com', 'a', 'in', '64.233.179.9' ], |
573 | [ 'b.l.google.com', 'a', 'in', '64.233.179.9' ], |
465 | [ 'c.l.google.com', 'a', 'in', '64.233.161.9' ], |
574 | [ 'c.l.google.com', 'a', 'in', '64.233.161.9' ], |
466 | ], |
575 | ], |
467 | 'ns' => [ |
576 | 'ns' => [ |
468 | [ 'l.google.com', 'ns', 'in', 'a.l.google.com' ], |
577 | [ 'l.google.com', 'ns', 'in', 'a.l.google.com' ], |
469 | [ 'l.google.com', 'ns', 'in', 'b.l.google.com' ], |
578 | [ 'l.google.com', 'ns', 'in', 'b.l.google.com' ], |
470 | ], |
579 | ], |
471 | 'tc' => '', |
580 | 'tc' => '', |
472 | 'ra' => 1, |
581 | 'ra' => 1, |
473 | 'qr' => 1, |
582 | 'qr' => 1, |
474 | 'id' => 64265, |
583 | 'id' => 64265, |
475 | 'aa' => '', |
584 | 'aa' => '', |
476 | 'an' => [ |
585 | 'an' => [ |
477 | [ 'www.google.de', 'cname', 'in', 'www.google.com' ], |
586 | [ 'www.google.de', 'cname', 'in', 'www.google.com' ], |
478 | [ 'www.google.com', 'cname', 'in', 'www.l.google.com' ], |
587 | [ 'www.google.com', 'cname', 'in', 'www.l.google.com' ], |
479 | [ 'www.l.google.com', 'a', 'in', '66.249.93.104' ], |
588 | [ 'www.l.google.com', 'a', 'in', '66.249.93.104' ], |
480 | [ 'www.l.google.com', 'a', 'in', '66.249.93.147' ], |
589 | [ 'www.l.google.com', 'a', 'in', '66.249.93.147' ], |
481 | ], |
590 | ], |
482 | 'rd' => 1, |
591 | 'rd' => 1, |
483 | 'op' => 0 |
592 | 'op' => 0 |
484 | } |
593 | } |
485 | |
594 | |
486 | =cut |
595 | =cut |
487 | |
596 | |
488 | sub dns_unpack($) { |
597 | sub dns_unpack($) { |
489 | local $pkt = shift; |
598 | local $pkt = shift; |
… | |
… | |
581 | The number of dots (default: C<1>) that a name must have so that the resolver |
690 | The number of dots (default: C<1>) that a name must have so that the resolver |
582 | tries to resolve the name without any suffixes first. |
691 | tries to resolve the name without any suffixes first. |
583 | |
692 | |
584 | =item max_outstanding => $integer |
693 | =item max_outstanding => $integer |
585 | |
694 | |
586 | Most name servers do not handle many parallel requests very well. This option |
695 | Most name servers do not handle many parallel requests very well. This |
587 | limits the number of outstanding requests to C<$n> (default: C<10>), that means |
696 | option limits the number of outstanding requests to C<$integer> |
588 | if you request more than this many requests, then the additional requests will be queued |
697 | (default: C<10>), that means if you request more than this many requests, |
589 | until some other requests have been resolved. |
698 | then the additional requests will be queued until some other requests have |
|
|
699 | been resolved. |
590 | |
700 | |
591 | =item reuse => $seconds |
701 | =item reuse => $seconds |
592 | |
702 | |
593 | The number of seconds (default: C<300>) that a query id cannot be re-used |
703 | The number of seconds (default: C<300>) that a query id cannot be re-used |
594 | after a timeout. If there as no time-out then query id's can be reused |
704 | after a timeout. If there was no time-out then query ids can be reused |
595 | immediately. |
705 | immediately. |
596 | |
706 | |
597 | =back |
707 | =back |
598 | |
708 | |
599 | =cut |
709 | =cut |
600 | |
710 | |
601 | sub new { |
711 | sub new { |
602 | my ($class, %arg) = @_; |
712 | my ($class, %arg) = @_; |
603 | |
|
|
604 | # try to create a ipv4 and an ipv6 socket |
|
|
605 | # only fail when we cnanot create either |
|
|
606 | |
|
|
607 | socket my $fh4, AF_INET , &Socket::SOCK_DGRAM, 0; |
|
|
608 | socket my $fh6, AF_INET6, &Socket::SOCK_DGRAM, 0; |
|
|
609 | |
|
|
610 | $fh4 || $fh6 |
|
|
611 | or Carp::croak "unable to create either an IPv6 or an IPv4 socket"; |
|
|
612 | |
713 | |
613 | my $self = bless { |
714 | my $self = bless { |
614 | server => [], |
715 | server => [], |
615 | timeout => [2, 5, 5], |
716 | timeout => [2, 5, 5], |
616 | search => [], |
717 | search => [], |
617 | ndots => 1, |
718 | ndots => 1, |
618 | max_outstanding => 10, |
719 | max_outstanding => 10, |
619 | reuse => 300, # reuse id's after 5 minutes only, if possible |
720 | reuse => 300, |
620 | %arg, |
721 | %arg, |
621 | reuse_q => [], |
722 | reuse_q => [], |
622 | }, $class; |
723 | }, $class; |
623 | |
724 | |
624 | # search should default to gethostname's domain |
725 | # search should default to gethostname's domain |
625 | # but perl lacks a good posix module |
726 | # but perl lacks a good posix module |
626 | |
727 | |
|
|
728 | # try to create an ipv4 and an ipv6 socket |
|
|
729 | # only fail when we cannot create either |
|
|
730 | my $got_socket; |
|
|
731 | |
627 | Scalar::Util::weaken (my $wself = $self); |
732 | Scalar::Util::weaken (my $wself = $self); |
628 | |
733 | |
629 | if ($fh4) { |
734 | if (socket my $fh4, AF_INET , &Socket::SOCK_DGRAM, 0) { |
|
|
735 | ++$got_socket; |
|
|
736 | |
630 | AnyEvent::Util::fh_nonblocking $fh4, 1; |
737 | AnyEvent::Util::fh_nonblocking $fh4, 1; |
631 | $self->{fh4} = $fh4; |
738 | $self->{fh4} = $fh4; |
632 | $self->{rw4} = AnyEvent->io (fh => $fh4, poll => "r", cb => sub { |
739 | $self->{rw4} = AnyEvent->io (fh => $fh4, poll => "r", cb => sub { |
633 | if (my $peer = recv $fh4, my $pkt, MAX_PKT, 0) { |
740 | if (my $peer = recv $fh4, my $pkt, MAX_PKT, 0) { |
634 | $wself->_recv ($pkt, $peer); |
741 | $wself->_recv ($pkt, $peer); |
635 | } |
742 | } |
636 | }); |
743 | }); |
637 | } |
744 | } |
638 | |
745 | |
639 | if ($fh6) { |
746 | if (AF_INET6 && socket my $fh6, AF_INET6, &Socket::SOCK_DGRAM, 0) { |
|
|
747 | ++$got_socket; |
|
|
748 | |
640 | $self->{fh6} = $fh6; |
749 | $self->{fh6} = $fh6; |
641 | AnyEvent::Util::fh_nonblocking $fh6, 1; |
750 | AnyEvent::Util::fh_nonblocking $fh6, 1; |
642 | $self->{rw6} = AnyEvent->io (fh => $fh6, poll => "r", cb => sub { |
751 | $self->{rw6} = AnyEvent->io (fh => $fh6, poll => "r", cb => sub { |
643 | if (my $peer = recv $fh6, my $pkt, MAX_PKT, 0) { |
752 | if (my $peer = recv $fh6, my $pkt, MAX_PKT, 0) { |
644 | $wself->_recv ($pkt, $peer); |
753 | $wself->_recv ($pkt, $peer); |
645 | } |
754 | } |
646 | }); |
755 | }); |
647 | } |
756 | } |
|
|
757 | |
|
|
758 | $got_socket |
|
|
759 | or Carp::croak "unable to create either an IPv4 or an IPv6 socket"; |
648 | |
760 | |
649 | $self->_compile; |
761 | $self->_compile; |
650 | |
762 | |
651 | $self |
763 | $self |
652 | } |
764 | } |
… | |
… | |
729 | # - the registry thing needs separate code on win32 native vs. cygwin |
841 | # - the registry thing needs separate code on win32 native vs. cygwin |
730 | # - the registry layout differs between windows versions |
842 | # - the registry layout differs between windows versions |
731 | # - calling windows api functions doesn't work on cygwin |
843 | # - calling windows api functions doesn't work on cygwin |
732 | # - ipconfig uses locale-specific messages |
844 | # - ipconfig uses locale-specific messages |
733 | |
845 | |
734 | # we use ipconfig parsing because, despite all it's brokenness, |
846 | # we use ipconfig parsing because, despite all its brokenness, |
735 | # it seems most stable in practise. |
847 | # it seems most stable in practise. |
736 | # for good measure, we append a fallback nameserver to our list. |
848 | # for good measure, we append a fallback nameserver to our list. |
737 | |
849 | |
738 | if (open my $fh, "ipconfig /all |") { |
850 | if (open my $fh, "ipconfig /all |") { |
739 | # parsing strategy: we go through the output and look for |
851 | # parsing strategy: we go through the output and look for |
… | |
… | |
748 | } elsif (/^\S/ || /^\s[^:]{16,}: /) { |
860 | } elsif (/^\S/ || /^\s[^:]{16,}: /) { |
749 | $dns = 0; |
861 | $dns = 0; |
750 | } |
862 | } |
751 | if ($dns && /^\s*(\S+)\s*$/) { |
863 | if ($dns && /^\s*(\S+)\s*$/) { |
752 | my $s = $1; |
864 | my $s = $1; |
753 | $s =~ s/%\d+(?!\S)//; # get rid of scope id |
865 | $s =~ s/%\d+(?!\S)//; # get rid of ipv6 scope id |
754 | if (my $ipn = AnyEvent::Socket::parse_address ($s)) { |
866 | if (my $ipn = AnyEvent::Socket::parse_address ($s)) { |
755 | push @{ $self->{server} }, $ipn; |
867 | push @{ $self->{server} }, $ipn; |
756 | } else { |
868 | } else { |
757 | push @{ $self->{search} }, $s; |
869 | push @{ $self->{search} }, $s; |
758 | } |
870 | } |
… | |
… | |
772 | $self->parse_resolv_conf (<$fh>); |
884 | $self->parse_resolv_conf (<$fh>); |
773 | } |
885 | } |
774 | } |
886 | } |
775 | } |
887 | } |
776 | |
888 | |
|
|
889 | =item $resolver->timeout ($timeout, ...) |
|
|
890 | |
|
|
891 | Sets the timeout values. See the C<timeout> constructor argument (and note |
|
|
892 | that this method uses the values itself, not an array-reference). |
|
|
893 | |
|
|
894 | =cut |
|
|
895 | |
|
|
896 | sub timeout { |
|
|
897 | my ($self, @timeout) = @_; |
|
|
898 | |
|
|
899 | $self->{timeout} = \@timeout; |
|
|
900 | $self->_compile; |
|
|
901 | } |
|
|
902 | |
|
|
903 | =item $resolver->max_outstanding ($nrequests) |
|
|
904 | |
|
|
905 | Sets the maximum number of outstanding requests to C<$nrequests>. See the |
|
|
906 | C<max_outstanding> constructor argument. |
|
|
907 | |
|
|
908 | =cut |
|
|
909 | |
|
|
910 | sub max_outstanding { |
|
|
911 | my ($self, $max) = @_; |
|
|
912 | |
|
|
913 | $self->{max_outstanding} = $max; |
|
|
914 | $self->_scheduler; |
|
|
915 | } |
|
|
916 | |
777 | sub _compile { |
917 | sub _compile { |
778 | my $self = shift; |
918 | my $self = shift; |
779 | |
919 | |
780 | my %search; $self->{search} = [grep 0 < length, grep !$search{$_}++, @{ $self->{search} }]; |
920 | my %search; $self->{search} = [grep 0 < length, grep !$search{$_}++, @{ $self->{search} }]; |
781 | my %server; $self->{server} = [grep 0 < length, grep !$server{$_}++, @{ $self->{server} }]; |
921 | my %server; $self->{server} = [grep 0 < length, grep !$server{$_}++, @{ $self->{server} }]; |
… | |
… | |
858 | |
998 | |
859 | $self->{id}{$req->[2]} = [AnyEvent->timer (after => $timeout, cb => sub { |
999 | $self->{id}{$req->[2]} = [AnyEvent->timer (after => $timeout, cb => sub { |
860 | $NOW = time; |
1000 | $NOW = time; |
861 | |
1001 | |
862 | # timeout, try next |
1002 | # timeout, try next |
863 | &$do_retry; |
1003 | &$do_retry if $do_retry; |
864 | }), sub { |
1004 | }), sub { |
865 | my ($res) = @_; |
1005 | my ($res) = @_; |
866 | |
1006 | |
867 | if ($res->{tc}) { |
1007 | if ($res->{tc}) { |
868 | # success, but truncated, so use tcp |
1008 | # success, but truncated, so use tcp |
869 | AnyEvent::Socket::tcp_connect (AnyEvent::Socket::format_address ($server), DOMAIN_PORT, sub { |
1009 | AnyEvent::Socket::tcp_connect (AnyEvent::Socket::format_address ($server), DOMAIN_PORT, sub { |
|
|
1010 | return unless $do_retry; # some other request could have invalidated us already |
|
|
1011 | |
870 | my ($fh) = @_ |
1012 | my ($fh) = @_ |
871 | or return &$do_retry; |
1013 | or return &$do_retry; |
872 | |
1014 | |
873 | my $handle = new AnyEvent::Handle |
1015 | my $handle; $handle = new AnyEvent::Handle |
874 | fh => $fh, |
1016 | fh => $fh, |
|
|
1017 | timeout => $timeout, |
875 | on_error => sub { |
1018 | on_error => sub { |
|
|
1019 | undef $handle; |
|
|
1020 | return unless $do_retry; # some other request could have invalidated us already |
876 | # failure, try next |
1021 | # failure, try next |
877 | &$do_retry; |
1022 | &$do_retry; |
878 | }; |
1023 | }; |
879 | |
1024 | |
880 | $handle->push_write (pack "n/a", $req->[0]); |
1025 | $handle->push_write (pack "n/a", $req->[0]); |
881 | $handle->push_read (chunk => 2, sub { |
1026 | $handle->push_read (chunk => 2, sub { |
882 | $handle->unshift_read (chunk => (unpack "n", $_[1]), sub { |
1027 | $handle->unshift_read (chunk => (unpack "n", $_[1]), sub { |
|
|
1028 | undef $handle; |
883 | $self->_feed ($_[1]); |
1029 | $self->_feed ($_[1]); |
884 | }); |
1030 | }); |
885 | }); |
1031 | }); |
886 | shutdown $fh, 1; |
|
|
887 | |
1032 | |
888 | }, sub { $timeout }); |
1033 | }, sub { $timeout }); |
889 | |
1034 | |
890 | } else { |
1035 | } else { |
891 | # success |
1036 | # success |
… | |
… | |
907 | } |
1052 | } |
908 | |
1053 | |
909 | sub _scheduler { |
1054 | sub _scheduler { |
910 | my ($self) = @_; |
1055 | my ($self) = @_; |
911 | |
1056 | |
|
|
1057 | no strict 'refs'; |
|
|
1058 | |
912 | $NOW = time; |
1059 | $NOW = time; |
913 | |
1060 | |
914 | # first clear id reuse queue |
1061 | # first clear id reuse queue |
915 | delete $self->{id}{ (shift @{ $self->{reuse_q} })->[1] } |
1062 | delete $self->{id}{ (shift @{ $self->{reuse_q} })->[1] } |
916 | while @{ $self->{reuse_q} } && $self->{reuse_q}[0][0] <= $NOW; |
1063 | while @{ $self->{reuse_q} } && $self->{reuse_q}[0][0] <= $NOW; |
… | |
… | |
924 | $self->_scheduler; |
1071 | $self->_scheduler; |
925 | }); |
1072 | }); |
926 | last; |
1073 | last; |
927 | } |
1074 | } |
928 | |
1075 | |
929 | my $req = shift @{ $self->{queue} } |
1076 | if (my $req = shift @{ $self->{queue} }) { |
930 | or last; |
1077 | # found a request in the queue, execute it |
931 | |
|
|
932 | while () { |
1078 | while () { |
933 | $req->[2] = int rand 65536; |
1079 | $req->[2] = int rand 65536; |
934 | last unless exists $self->{id}{$req->[2]}; |
1080 | last unless exists $self->{id}{$req->[2]}; |
|
|
1081 | } |
|
|
1082 | |
|
|
1083 | ++$self->{outstanding}; |
|
|
1084 | $self->{id}{$req->[2]} = 1; |
|
|
1085 | substr $req->[0], 0, 2, pack "n", $req->[2]; |
|
|
1086 | |
|
|
1087 | $self->_exec ($req); |
|
|
1088 | |
|
|
1089 | } elsif (my $cb = shift @{ $self->{wait} }) { |
|
|
1090 | # found a wait_for_slot callback, call that one first |
|
|
1091 | $cb->($self); |
|
|
1092 | |
|
|
1093 | } else { |
|
|
1094 | # nothing to do, just exit |
|
|
1095 | last; |
935 | } |
1096 | } |
936 | |
|
|
937 | ++$self->{outstanding}; |
|
|
938 | $self->{id}{$req->[2]} = 1; |
|
|
939 | substr $req->[0], 0, 2, pack "n", $req->[2]; |
|
|
940 | |
|
|
941 | $self->_exec ($req); |
|
|
942 | } |
1097 | } |
943 | } |
1098 | } |
944 | |
1099 | |
945 | =item $resolver->request ($req, $cb->($res)) |
1100 | =item $resolver->request ($req, $cb->($res)) |
946 | |
1101 | |
|
|
1102 | This is the main low-level workhorse for sending DNS requests. |
|
|
1103 | |
947 | Sends a single request (a hash-ref formated as specified for |
1104 | This function sends a single request (a hash-ref formated as specified |
948 | C<dns_pack>) to the configured nameservers including |
1105 | for C<dns_pack>) to the configured nameservers in turn until it gets a |
|
|
1106 | response. It handles timeouts, retries and automatically falls back to |
|
|
1107 | virtual circuit mode (TCP) when it receives a truncated reply. |
|
|
1108 | |
949 | retries. Calls the callback with the decoded response packet if a reply |
1109 | Calls the callback with the decoded response packet if a reply was |
950 | was received, or no arguments on timeout. |
1110 | received, or no arguments in case none of the servers answered. |
951 | |
1111 | |
952 | =cut |
1112 | =cut |
953 | |
1113 | |
954 | sub request($$) { |
1114 | sub request($$) { |
955 | my ($self, $req, $cb) = @_; |
1115 | my ($self, $req, $cb) = @_; |
956 | |
1116 | |
957 | push @{ $self->{queue} }, [dns_pack $req, $cb]; |
1117 | push @{ $self->{queue} }, [dns_pack $req, $cb]; |
958 | $self->_scheduler; |
1118 | $self->_scheduler; |
959 | } |
1119 | } |
960 | |
1120 | |
961 | =item $resolver->resolve ($qname, $qtype, %options, $cb->($rcode, @rr)) |
1121 | =item $resolver->resolve ($qname, $qtype, %options, $cb->(@rr)) |
962 | |
1122 | |
963 | Queries the DNS for the given domain name C<$qname> of type C<$qtype> (a |
1123 | Queries the DNS for the given domain name C<$qname> of type C<$qtype>. |
964 | qtype of "*" is supported and means "any"). |
1124 | |
|
|
1125 | A C<$qtype> is either a numerical query type (e.g. C<1> for A records) or |
|
|
1126 | a lowercase name (you have to look at the source to see which aliases are |
|
|
1127 | supported, but all types from RFC 1035, C<aaaa>, C<srv>, C<spf> and a few |
|
|
1128 | more are known to this module). A C<$qtype> of "*" is supported and means |
|
|
1129 | "any" record type. |
965 | |
1130 | |
966 | The callback will be invoked with a list of matching result records or |
1131 | The callback will be invoked with a list of matching result records or |
967 | none on any error or if the name could not be found. |
1132 | none on any error or if the name could not be found. |
968 | |
1133 | |
969 | CNAME chains (although illegal) are followed up to a length of 8. |
1134 | CNAME chains (although illegal) are followed up to a length of 10. |
|
|
1135 | |
|
|
1136 | The callback will be invoked with arraryefs of the form C<[$name, $type, |
|
|
1137 | $class, @data>], where C<$name> is the domain name, C<$type> a type string |
|
|
1138 | or number, C<$class> a class name and @data is resource-record-dependent |
|
|
1139 | data. For C<a> records, this will be the textual IPv4 addresses, for C<ns> |
|
|
1140 | or C<cname> records this will be a domain name, for C<txt> records these |
|
|
1141 | are all the strings and so on. |
|
|
1142 | |
|
|
1143 | All types mentioned in RFC 1035, C<aaaa>, C<srv>, C<naptr> and C<spf> are |
|
|
1144 | decoded. All resource records not known to this module will have |
|
|
1145 | the raw C<rdata> field as fourth entry. |
970 | |
1146 | |
971 | Note that this resolver is just a stub resolver: it requires a name server |
1147 | Note that this resolver is just a stub resolver: it requires a name server |
972 | supporting recursive queries, will not do any recursive queries itself and |
1148 | supporting recursive queries, will not do any recursive queries itself and |
973 | is not secure when used against an untrusted name server. |
1149 | is not secure when used against an untrusted name server. |
974 | |
1150 | |
… | |
… | |
978 | |
1154 | |
979 | =item search => [$suffix...] |
1155 | =item search => [$suffix...] |
980 | |
1156 | |
981 | Use the given search list (which might be empty), by appending each one |
1157 | Use the given search list (which might be empty), by appending each one |
982 | in turn to the C<$qname>. If this option is missing then the configured |
1158 | in turn to the C<$qname>. If this option is missing then the configured |
983 | C<ndots> and C<search> define its value. If the C<$qname> ends in a dot, |
1159 | C<ndots> and C<search> values define its value (depending on C<ndots>, the |
984 | then the searchlist will be ignored. |
1160 | empty suffix will be prepended or appended to that C<search> value). If |
|
|
1161 | the C<$qname> ends in a dot, then the searchlist will be ignored. |
985 | |
1162 | |
986 | =item accept => [$type...] |
1163 | =item accept => [$type...] |
987 | |
1164 | |
988 | Lists the acceptable result types: only result types in this set will be |
1165 | Lists the acceptable result types: only result types in this set will be |
989 | accepted and returned. The default includes the C<$qtype> and nothing |
1166 | accepted and returned. The default includes the C<$qtype> and nothing |
990 | else. |
1167 | else. If this list includes C<cname>, then CNAME-chains will not be |
|
|
1168 | followed (because you asked for the CNAME record). |
991 | |
1169 | |
992 | =item class => "class" |
1170 | =item class => "class" |
993 | |
1171 | |
994 | Specify the query class ("in" for internet, "ch" for chaosnet and "hs" for |
1172 | Specify the query class ("in" for internet, "ch" for chaosnet and "hs" for |
995 | hesiod are the only ones making sense). The default is "in", of course. |
1173 | hesiod are the only ones making sense). The default is "in", of course. |
996 | |
1174 | |
997 | =back |
1175 | =back |
998 | |
1176 | |
999 | Examples: |
1177 | Examples: |
1000 | |
1178 | |
1001 | $res->resolve ("ruth.plan9.de", "a", sub { |
1179 | # full example, you can paste this into perl: |
1002 | warn Dumper [@_]; |
1180 | use Data::Dumper; |
1003 | }); |
1181 | use AnyEvent::DNS; |
|
|
1182 | AnyEvent::DNS::resolver->resolve ( |
|
|
1183 | "google.com", "*", my $cv = AnyEvent->condvar); |
|
|
1184 | warn Dumper [$cv->recv]; |
1004 | |
1185 | |
|
|
1186 | # shortened result: |
1005 | [ |
1187 | # [ |
|
|
1188 | # [ 'google.com', 'soa', 'in', 'ns1.google.com', 'dns-admin.google.com', |
|
|
1189 | # 2008052701, 7200, 1800, 1209600, 300 ], |
1006 | [ |
1190 | # [ |
1007 | 'ruth.schmorp.de', |
1191 | # 'google.com', 'txt', 'in', |
1008 | 'a', |
1192 | # 'v=spf1 include:_netblocks.google.com ~all' |
1009 | 'in', |
1193 | # ], |
1010 | '129.13.162.95' |
1194 | # [ 'google.com', 'a', 'in', '64.233.187.99' ], |
|
|
1195 | # [ 'google.com', 'mx', 'in', 10, 'smtp2.google.com' ], |
|
|
1196 | # [ 'google.com', 'ns', 'in', 'ns2.google.com' ], |
1011 | ] |
1197 | # ] |
|
|
1198 | |
|
|
1199 | # resolve a records: |
|
|
1200 | $res->resolve ("ruth.plan9.de", "a", sub { warn Dumper [@_] }); |
|
|
1201 | |
|
|
1202 | # result: |
|
|
1203 | # [ |
|
|
1204 | # [ 'ruth.schmorp.de', 'a', 'in', '129.13.162.95' ] |
1012 | ] |
1205 | # ] |
1013 | |
1206 | |
|
|
1207 | # resolve any records, but return only a and aaaa records: |
1014 | $res->resolve ("test1.laendle", "*", |
1208 | $res->resolve ("test1.laendle", "*", |
1015 | accept => ["a", "aaaa"], |
1209 | accept => ["a", "aaaa"], |
1016 | sub { |
1210 | sub { |
1017 | warn Dumper [@_]; |
1211 | warn Dumper [@_]; |
1018 | } |
1212 | } |
1019 | ); |
1213 | ); |
1020 | |
1214 | |
1021 | [ |
1215 | # result: |
1022 | [ |
1216 | # [ |
1023 | 'test1.laendle', |
1217 | # [ 'test1.laendle', 'a', 'in', '10.0.0.255' ], |
1024 | 'a', |
1218 | # [ 'test1.laendle', 'aaaa', 'in', '3ffe:1900:4545:0002:0240:0000:0000:f7e1' ] |
1025 | 'in', |
|
|
1026 | '10.0.0.255' |
|
|
1027 | ], |
|
|
1028 | [ |
|
|
1029 | 'test1.laendle', |
|
|
1030 | 'aaaa', |
|
|
1031 | 'in', |
|
|
1032 | '3ffe:1900:4545:0002:0240:0000:0000:f7e1' |
|
|
1033 | ] |
1219 | # ] |
1034 | ] |
|
|
1035 | |
1220 | |
1036 | =cut |
1221 | =cut |
1037 | |
1222 | |
1038 | sub resolve($%) { |
1223 | sub resolve($%) { |
1039 | my $cb = pop; |
1224 | my $cb = pop; |
… | |
… | |
1059 | $do_search = sub { |
1244 | $do_search = sub { |
1060 | @search |
1245 | @search |
1061 | or (undef $do_search), (undef $do_req), return $cb->(); |
1246 | or (undef $do_search), (undef $do_req), return $cb->(); |
1062 | |
1247 | |
1063 | (my $name = lc "$qname." . shift @search) =~ s/\.$//; |
1248 | (my $name = lc "$qname." . shift @search) =~ s/\.$//; |
1064 | my $depth = 2; |
1249 | my $depth = 10; |
1065 | |
1250 | |
1066 | # advance in cname-chain |
1251 | # advance in cname-chain |
1067 | $do_req = sub { |
1252 | $do_req = sub { |
1068 | $self->request ({ |
1253 | $self->request ({ |
1069 | rd => 1, |
1254 | rd => 1, |
… | |
… | |
1107 | }; |
1292 | }; |
1108 | |
1293 | |
1109 | $do_search->(); |
1294 | $do_search->(); |
1110 | } |
1295 | } |
1111 | |
1296 | |
|
|
1297 | =item $resolver->wait_for_slot ($cb->($resolver)) |
|
|
1298 | |
|
|
1299 | Wait until a free request slot is available and call the callback with the |
|
|
1300 | resolver object. |
|
|
1301 | |
|
|
1302 | A request slot is used each time a request is actually sent to the |
|
|
1303 | nameservers: There are never more than C<max_outstanding> of them. |
|
|
1304 | |
|
|
1305 | Although you can submit more requests (they will simply be queued until |
|
|
1306 | a request slot becomes available), sometimes, usually for rate-limiting |
|
|
1307 | purposes, it is useful to instead wait for a slot before generating the |
|
|
1308 | request (or simply to know when the request load is low enough so one can |
|
|
1309 | submit requests again). |
|
|
1310 | |
|
|
1311 | This is what this method does: The callback will be called when submitting |
|
|
1312 | a DNS request will not result in that request being queued. The callback |
|
|
1313 | may or may not generate any requests in response. |
|
|
1314 | |
|
|
1315 | Note that the callback will only be invoked when the request queue is |
|
|
1316 | empty, so this does not play well if somebody else keeps the request queue |
|
|
1317 | full at all times. |
|
|
1318 | |
|
|
1319 | =cut |
|
|
1320 | |
|
|
1321 | sub wait_for_slot { |
|
|
1322 | my ($self, $cb) = @_; |
|
|
1323 | |
|
|
1324 | push @{ $self->{wait} }, $cb; |
|
|
1325 | $self->_scheduler; |
|
|
1326 | } |
|
|
1327 | |
1112 | use AnyEvent::Socket (); # circular dependency, so do not import anything and do it at the end |
1328 | use AnyEvent::Socket (); # circular dependency, so do not import anything and do it at the end |
1113 | |
1329 | |
1114 | 1; |
1330 | 1; |
1115 | |
1331 | |
1116 | =back |
1332 | =back |
1117 | |
1333 | |
1118 | =head1 AUTHOR |
1334 | =head1 AUTHOR |
1119 | |
1335 | |
1120 | Marc Lehmann <schmorp@schmorp.de> |
1336 | Marc Lehmann <schmorp@schmorp.de> |
1121 | http://home.schmorp.de/ |
1337 | http://home.schmorp.de/ |
1122 | |
1338 | |
1123 | =cut |
1339 | =cut |
1124 | |
1340 | |