1 |
=head1 NAME |
2 |
|
3 |
AnyEvent::Socket - useful IPv4 and IPv6 stuff. |
4 |
|
5 |
=head1 SYNOPSIS |
6 |
|
7 |
use AnyEvent::Socket; |
8 |
|
9 |
tcp_connect "gameserver.deliantra.net", 13327, sub { |
10 |
my ($fh) = @_ |
11 |
or die "gameserver.deliantra.net connect failed: $!"; |
12 |
|
13 |
# enjoy your filehandle |
14 |
}; |
15 |
|
16 |
# a simple tcp server |
17 |
tcp_server undef, 8888, sub { |
18 |
my ($fh, $host, $port) = @_; |
19 |
|
20 |
syswrite $fh, "The internet is full, $host:$port. Go away!\015\012"; |
21 |
}; |
22 |
|
23 |
=head1 DESCRIPTION |
24 |
|
25 |
This module implements various utility functions for handling internet |
26 |
protocol addresses and sockets, in an as transparent and simple way as |
27 |
possible. |
28 |
|
29 |
All functions documented without C<AnyEvent::Socket::> prefix are exported |
30 |
by default. |
31 |
|
32 |
=over 4 |
33 |
|
34 |
=cut |
35 |
|
36 |
package AnyEvent::Socket; |
37 |
|
38 |
no warnings; |
39 |
use strict; |
40 |
|
41 |
use Carp (); |
42 |
use Errno (); |
43 |
use Socket qw(AF_INET SOCK_STREAM SOCK_DGRAM SOL_SOCKET SO_REUSEADDR); |
44 |
|
45 |
use AnyEvent (); |
46 |
use AnyEvent::Util qw(guard fh_nonblocking AF_INET6); |
47 |
use AnyEvent::DNS (); |
48 |
|
49 |
use base 'Exporter'; |
50 |
|
51 |
our @EXPORT = qw(parse_ipv4 parse_ipv6 parse_ip format_ip inet_aton tcp_server tcp_connect); |
52 |
|
53 |
our $VERSION = '1.0'; |
54 |
|
55 |
=item $ipn = parse_ipv4 $dotted_quad |
56 |
|
57 |
Tries to parse the given dotted quad IPv4 address and return it in |
58 |
octet form (or undef when it isn't in a parsable format). Supports all |
59 |
forms specified by POSIX (e.g. C<10.0.0.1>, C<10.1>, C<10.0x020304>, |
60 |
C<0x12345678> or C<0377.0377.0377.0377>). |
61 |
|
62 |
=cut |
63 |
|
64 |
sub parse_ipv4($) { |
65 |
$_[0] =~ /^ (?: 0x[0-9a-fA-F]+ | 0[0-7]* | [1-9][0-9]* ) |
66 |
(?:\. (?: 0x[0-9a-fA-F]+ | 0[0-7]* | [1-9][0-9]* ) ){0,3}$/x |
67 |
or return undef; |
68 |
|
69 |
@_ = map /^0/ ? oct : $_, split /\./, $_[0]; |
70 |
|
71 |
# check leading parts against range |
72 |
return undef if grep $_ >= 256, @_[0 .. @_ - 2]; |
73 |
|
74 |
# check trailing part against range |
75 |
return undef if $_[-1] >= 1 << (8 * (4 - $#_)); |
76 |
|
77 |
pack "N", (pop) |
78 |
+ ($_[0] << 24) |
79 |
+ ($_[1] << 16) |
80 |
+ ($_[2] << 8); |
81 |
} |
82 |
|
83 |
=item $ipn = parse_ipv6 $textual_ipv6_address |
84 |
|
85 |
Tries to parse the given IPv6 address and return it in |
86 |
octet form (or undef when it isn't in a parsable format). |
87 |
|
88 |
Should support all forms specified by RFC 2373 (and additionally all IPv4 |
89 |
forms supported by parse_ipv4). |
90 |
|
91 |
This function works similarly to C<inet_pton AF_INET6, ...>. |
92 |
|
93 |
=cut |
94 |
|
95 |
sub parse_ipv6($) { |
96 |
# quick test to avoid longer processing |
97 |
my $n = $_[0] =~ y/://; |
98 |
return undef if $n < 2 || $n > 8; |
99 |
|
100 |
my ($h, $t) = split /::/, $_[0], 2; |
101 |
|
102 |
unless (defined $t) { |
103 |
($h, $t) = (undef, $h); |
104 |
} |
105 |
|
106 |
my @h = split /:/, $h; |
107 |
my @t = split /:/, $t; |
108 |
|
109 |
# check for ipv4 tail |
110 |
if (@t && $t[-1]=~ /\./) { |
111 |
return undef if $n > 6; |
112 |
|
113 |
my $ipn = parse_ipv4 pop @t |
114 |
or return undef; |
115 |
|
116 |
push @t, map +(sprintf "%x", $_), unpack "nn", $ipn; |
117 |
} |
118 |
|
119 |
# no :: then we need to have exactly 8 components |
120 |
return undef unless @h + @t == 8 || $_[0] =~ /::/; |
121 |
|
122 |
# now check all parts for validity |
123 |
return undef if grep !/^[0-9a-fA-F]{1,4}$/, @h, @t; |
124 |
|
125 |
# now pad... |
126 |
push @h, 0 while @h + @t < 8; |
127 |
|
128 |
# and done |
129 |
pack "n*", map hex, @h, @t |
130 |
} |
131 |
|
132 |
=item $ipn = parse_ip $text |
133 |
|
134 |
Combines C<parse_ipv4> and C<parse_ipv6> in one function. |
135 |
|
136 |
=cut |
137 |
|
138 |
sub parse_ip($) { |
139 |
&parse_ipv4 || &parse_ipv6 |
140 |
} |
141 |
|
142 |
=item $text = format_ip $ipn |
143 |
|
144 |
Takes either an IPv4 address (4 octets) or and IPv6 address (16 octets) |
145 |
and converts it into textual form. |
146 |
|
147 |
This function works similarly to C<inet_ntop AF_INET || AF_INET6, ...>, |
148 |
except it automatically detects the address type. |
149 |
|
150 |
=cut |
151 |
|
152 |
sub format_ip; |
153 |
sub format_ip($) { |
154 |
if (4 == length $_[0]) { |
155 |
return join ".", unpack "C4", $_[0] |
156 |
} elsif (16 == length $_[0]) { |
157 |
if (v0.0.0.0.0.0.0.0.0.0.255.255 eq substr $_[0], 0, 12) { |
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# v4mapped |
159 |
return "::ffff:" . format_ip substr $_[0], 12; |
160 |
} else { |
161 |
my $ip = sprintf "%x:%x:%x:%x:%x:%x:%x:%x", unpack "n8", $_[0]; |
162 |
|
163 |
$ip =~ s/^0:(?:0:)*(0$)?/::/ |
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or $ip =~ s/(:0)+$/::/ |
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or $ip =~ s/(:0)+/:/; |
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return $ip |
167 |
} |
168 |
} else { |
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return undef |
170 |
} |
171 |
} |
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|
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=item inet_aton $name_or_address, $cb->(@addresses) |
174 |
|
175 |
Works similarly to its Socket counterpart, except that it uses a |
176 |
callback. Also, if a host has only an IPv6 address, this might be passed |
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to the callback instead (use the length to detect this - 4 for IPv4, 16 |
178 |
for IPv6). |
179 |
|
180 |
Unlike the L<Socket> function of the same name, you can get multiple IPv4 |
181 |
and IPv6 addresses as result. |
182 |
|
183 |
=cut |
184 |
|
185 |
sub inet_aton { |
186 |
my ($name, $cb) = @_; |
187 |
|
188 |
if (my $ipn = &parse_ipv4) { |
189 |
$cb->($ipn); |
190 |
} elsif (my $ipn = &parse_ipv6) { |
191 |
$cb->($ipn); |
192 |
} elsif ($name eq "localhost") { # rfc2606 et al. |
193 |
$cb->(v127.0.0.1, v0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.1); |
194 |
} else { |
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require AnyEvent::DNS; |
196 |
|
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# simple, bad suboptimal algorithm |
198 |
AnyEvent::DNS::a ($name, sub { |
199 |
if (@_) { |
200 |
$cb->(map +(parse_ipv4 $_), @_); |
201 |
} else { |
202 |
$cb->(); |
203 |
#AnyEvent::DNS::aaaa ($name, $cb); need inet_pton |
204 |
} |
205 |
}); |
206 |
} |
207 |
} |
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|
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=item $sa = AnyEvent::Socket::pack_sockaddr $port, $host |
210 |
|
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Pack the given port/host combination into a binary sockaddr structure. Handles |
212 |
both IPv4 and IPv6 host addresses. |
213 |
|
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=cut |
215 |
|
216 |
sub pack_sockaddr($$) { |
217 |
if (4 == length $_[1]) { |
218 |
Socket::pack_sockaddr_in $_[0], $_[1] |
219 |
} elsif (16 == length $_[1]) { |
220 |
pack "SnL a16 L", |
221 |
AF_INET6, |
222 |
$_[0], # port |
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0, # flowinfo |
224 |
$_[1], # addr |
225 |
0 # scope id |
226 |
} else { |
227 |
Carp::croak "pack_sockaddr: invalid host"; |
228 |
} |
229 |
} |
230 |
|
231 |
=item ($port, $host) = AnyEvent::Socket::unpack_sockaddr $sa |
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|
233 |
Unpack the given binary sockaddr structure (as used by bind, getpeername |
234 |
etc.) into a C<$port, $host> combination. |
235 |
|
236 |
Handles both IPv4 and IPv6 sockaddr structures. |
237 |
|
238 |
=cut |
239 |
|
240 |
sub unpack_sockaddr($) { |
241 |
my $af = unpack "S", $_[0]; |
242 |
|
243 |
if ($af == AF_INET) { |
244 |
Socket::unpack_sockaddr_in $_[0] |
245 |
} elsif ($af == AF_INET6) { |
246 |
unpack "x2 n x4 a16", $_[0] |
247 |
} else { |
248 |
Carp::croak "unpack_sockaddr: unsupported protocol family $af"; |
249 |
} |
250 |
} |
251 |
|
252 |
sub _tcp_port($) { |
253 |
$_[0] =~ /^(\d*)$/ and return $1*1; |
254 |
|
255 |
(getservbyname $_[0], "tcp")[2] |
256 |
or Carp::croak "$_[0]: service unknown" |
257 |
} |
258 |
|
259 |
=item $guard = tcp_connect $host, $service, $connect_cb[, $prepare_cb] |
260 |
|
261 |
This is a convenience function that creates a TCP socket and makes a 100% |
262 |
non-blocking connect to the given C<$host> (which can be a hostname or a |
263 |
textual IP address) and C<$service> (which can be a numeric port number or |
264 |
a service name, or a C<servicename=portnumber> string). |
265 |
|
266 |
If both C<$host> and C<$port> are names, then this function will use SRV |
267 |
records to locate the real target(s). |
268 |
|
269 |
In either case, it will create a list of target hosts (e.g. for multihomed |
270 |
hosts or hosts with both IPv4 and IPv6 addresses) and try to connect to |
271 |
each in turn. |
272 |
|
273 |
If the connect is successful, then the C<$connect_cb> will be invoked with |
274 |
the socket file handle (in non-blocking mode) as first and the peer host |
275 |
(as a textual IP address) and peer port as second and third arguments, |
276 |
respectively. The fourth argument is a code reference that you can call |
277 |
if, for some reason, you don't like this connection, which will cause |
278 |
C<tcp_connect> to try the next one (or call your callback without any |
279 |
arguments if there are no more connections). In most cases, you can simply |
280 |
ignore this argument. |
281 |
|
282 |
$cb->($filehandle, $host, $port, $retry) |
283 |
|
284 |
If the connect is unsuccessful, then the C<$connect_cb> will be invoked |
285 |
without any arguments and C<$!> will be set appropriately (with C<ENXIO> |
286 |
indicating a DNS resolution failure). |
287 |
|
288 |
The file handle is perfect for being plugged into L<AnyEvent::Handle>, but |
289 |
can be used as a normal perl file handle as well. |
290 |
|
291 |
Unless called in void context, C<tcp_connect> returns a guard object that |
292 |
will automatically abort connecting when it gets destroyed (it does not do |
293 |
anything to the socket after the connect was successful). |
294 |
|
295 |
Sometimes you need to "prepare" the socket before connecting, for example, |
296 |
to C<bind> it to some port, or you want a specific connect timeout that |
297 |
is lower than your kernel's default timeout. In this case you can specify |
298 |
a second callback, C<$prepare_cb>. It will be called with the file handle |
299 |
in not-yet-connected state as only argument and must return the connection |
300 |
timeout value (or C<0>, C<undef> or the empty list to indicate the default |
301 |
timeout is to be used). |
302 |
|
303 |
Note that the socket could be either a IPv4 TCP socket or an IPv6 TCP |
304 |
socket (although only IPv4 is currently supported by this module). |
305 |
|
306 |
Simple Example: connect to localhost on port 22. |
307 |
|
308 |
tcp_connect localhost => 22, sub { |
309 |
my $fh = shift |
310 |
or die "unable to connect: $!"; |
311 |
# do something |
312 |
}; |
313 |
|
314 |
Complex Example: connect to www.google.com on port 80 and make a simple |
315 |
GET request without much error handling. Also limit the connection timeout |
316 |
to 15 seconds. |
317 |
|
318 |
tcp_connect "www.google.com", "http", |
319 |
sub { |
320 |
my ($fh) = @_ |
321 |
or die "unable to connect: $!"; |
322 |
|
323 |
my $handle; # avoid direct assignment so on_eof has it in scope. |
324 |
$handle = new AnyEvent::Handle |
325 |
fh => $fh, |
326 |
on_eof => sub { |
327 |
undef $handle; # keep it alive till eof |
328 |
warn "done.\n"; |
329 |
}; |
330 |
|
331 |
$handle->push_write ("GET / HTTP/1.0\015\012\015\012"); |
332 |
|
333 |
$handle->push_read_line ("\015\012\015\012", sub { |
334 |
my ($handle, $line) = @_; |
335 |
|
336 |
# print response header |
337 |
print "HEADER\n$line\n\nBODY\n"; |
338 |
|
339 |
$handle->on_read (sub { |
340 |
# print response body |
341 |
print $_[0]->rbuf; |
342 |
$_[0]->rbuf = ""; |
343 |
}); |
344 |
}); |
345 |
}, sub { |
346 |
my ($fh) = @_; |
347 |
# could call $fh->bind etc. here |
348 |
|
349 |
15 |
350 |
}; |
351 |
|
352 |
=cut |
353 |
|
354 |
sub tcp_connect($$$;$) { |
355 |
my ($host, $port, $connect, $prepare) = @_; |
356 |
|
357 |
# see http://cr.yp.to/docs/connect.html for some background |
358 |
|
359 |
my %state = ( fh => undef ); |
360 |
|
361 |
# name resolution |
362 |
AnyEvent::DNS::addr $host, $port, 0, 0, 0, sub { |
363 |
my @target = @_; |
364 |
|
365 |
$state{next} = sub { |
366 |
return unless exists $state{fh}; |
367 |
|
368 |
my $target = shift @target |
369 |
or do { |
370 |
%state = (); |
371 |
return $connect->(); |
372 |
}; |
373 |
|
374 |
my ($domain, $type, $proto, $sockaddr) = @$target; |
375 |
|
376 |
# socket creation |
377 |
socket $state{fh}, $domain, $type, $proto |
378 |
or return $state{next}(); |
379 |
|
380 |
fh_nonblocking $state{fh}, 1; |
381 |
|
382 |
# prepare and optional timeout |
383 |
if ($prepare) { |
384 |
my $timeout = $prepare->($state{fh}); |
385 |
|
386 |
$state{to} = AnyEvent->timer (after => $timeout, cb => sub { |
387 |
$! = &Errno::ETIMEDOUT; |
388 |
$state{next}(); |
389 |
}) if $timeout; |
390 |
} |
391 |
|
392 |
# called when the connect was successful, which, |
393 |
# in theory, could be the case immediately (but never is in practise) |
394 |
my $connected = sub { |
395 |
delete $state{ww}; |
396 |
delete $state{to}; |
397 |
|
398 |
# we are connected, or maybe there was an error |
399 |
if (my $sin = getpeername $state{fh}) { |
400 |
my ($port, $host) = unpack_sockaddr $sin; |
401 |
|
402 |
my $guard = guard { |
403 |
%state = (); |
404 |
}; |
405 |
|
406 |
$connect->($state{fh}, format_ip $host, $port, sub { |
407 |
$guard->cancel; |
408 |
$state{next}(); |
409 |
}); |
410 |
} else { |
411 |
# dummy read to fetch real error code |
412 |
sysread $state{fh}, my $buf, 1 if $! == &Errno::ENOTCONN; |
413 |
$state{next}(); |
414 |
} |
415 |
}; |
416 |
|
417 |
# now connect |
418 |
if (connect $state{fh}, $sockaddr) { |
419 |
$connected->(); |
420 |
} elsif ($! == &Errno::EINPROGRESS || $! == &Errno::EWOULDBLOCK) { # EINPROGRESS is POSIX |
421 |
$state{ww} = AnyEvent->io (fh => $state{fh}, poll => 'w', cb => $connected); |
422 |
} else { |
423 |
%state = (); |
424 |
$connect->(); |
425 |
} |
426 |
}; |
427 |
|
428 |
$! = &Errno::ENXIO; |
429 |
$state{next}(); |
430 |
}; |
431 |
|
432 |
defined wantarray && guard { %state = () } |
433 |
} |
434 |
|
435 |
=item $guard = tcp_server $host, $port, $accept_cb[, $prepare_cb] |
436 |
|
437 |
Create and bind a TCP socket to the given host, and port, set the |
438 |
SO_REUSEADDR flag and call C<listen>. |
439 |
|
440 |
C<$host> must be an IPv4 or IPv6 address (or C<undef>, in which case it |
441 |
binds either to C<0> or to C<::>, depending on whether IPv4 or IPv6 is the |
442 |
preferred protocol). |
443 |
|
444 |
To bind to the IPv4 wildcard address, use C<0>, to bind to the IPv6 |
445 |
wildcard address, use C<::>. |
446 |
|
447 |
The port is specified by C<$port>, which must be either a service name or |
448 |
a numeric port number (or C<0> or C<undef>, in which case an ephemeral |
449 |
port will be used). |
450 |
|
451 |
For each new connection that could be C<accept>ed, call the C<< |
452 |
$accept_cb->($fh, $host, $port) >> with the file handle (in non-blocking |
453 |
mode) as first and the peer host and port as second and third arguments |
454 |
(see C<tcp_connect> for details). |
455 |
|
456 |
Croaks on any errors it can detect before the listen. |
457 |
|
458 |
If called in non-void context, then this function returns a guard object |
459 |
whose lifetime it tied to the TCP server: If the object gets destroyed, |
460 |
the server will be stopped (but existing accepted connections will |
461 |
continue). |
462 |
|
463 |
If you need more control over the listening socket, you can provide a |
464 |
C<< $prepare_cb->($fh, $host, $port) >>, which is called just before the |
465 |
C<listen ()> call, with the listen file handle as first argument, and IP |
466 |
address and port number of the local socket endpoint as second and third |
467 |
arguments. |
468 |
|
469 |
It should return the length of the listen queue (or C<0> for the default). |
470 |
|
471 |
Example: bind on some TCP port on the local machine and tell each client |
472 |
to go away. |
473 |
|
474 |
tcp_server undef, undef, sub { |
475 |
my ($fh, $host, $port) = @_; |
476 |
|
477 |
syswrite $fh, "The internet is full, $host:$port. Go away!\015\012"; |
478 |
}, sub { |
479 |
my ($fh, $thishost, $thisport) = @_; |
480 |
warn "bound to $thishost, port $thisport\n"; |
481 |
}; |
482 |
|
483 |
=cut |
484 |
|
485 |
sub tcp_server($$$;$) { |
486 |
my ($host, $port, $accept, $prepare) = @_; |
487 |
|
488 |
$host = $AnyEvent::PROTOCOL{ipv4} < $AnyEvent::PROTOCOL{ipv6} && AF_INET6 |
489 |
? "::" : "0" |
490 |
unless defined $host; |
491 |
|
492 |
my $ipn = parse_ip $host |
493 |
or Carp::croak "AnyEvent::Socket::tcp_server: cannot parse '$host' as IPv4 or IPv6 address"; |
494 |
|
495 |
my $domain = 4 == length $ipn ? AF_INET : AF_INET6; |
496 |
|
497 |
my %state; |
498 |
|
499 |
socket $state{fh}, $domain, SOCK_STREAM, 0 |
500 |
or Carp::croak "socket: $!"; |
501 |
|
502 |
setsockopt $state{fh}, SOL_SOCKET, SO_REUSEADDR, 1 |
503 |
or Carp::croak "so_reuseaddr: $!"; |
504 |
|
505 |
bind $state{fh}, pack_sockaddr _tcp_port $port, $ipn |
506 |
or Carp::croak "bind: $!"; |
507 |
|
508 |
fh_nonblocking $state{fh}, 1; |
509 |
|
510 |
my $len; |
511 |
|
512 |
if ($prepare) { |
513 |
my ($port, $host) = unpack_sockaddr getsockname $state{fh}; |
514 |
$len = $prepare && $prepare->($state{fh}, format_ip $host, $port); |
515 |
} |
516 |
|
517 |
$len ||= 128; |
518 |
|
519 |
listen $state{fh}, $len |
520 |
or Carp::croak "listen: $!"; |
521 |
|
522 |
$state{aw} = AnyEvent->io (fh => $state{fh}, poll => 'r', cb => sub { |
523 |
# this closure keeps $state alive |
524 |
while (my $peer = accept my $fh, $state{fh}) { |
525 |
fh_nonblocking $fh, 1; # POSIX requires inheritance, the outside world does not |
526 |
my ($port, $host) = unpack_sockaddr $peer; |
527 |
$accept->($fh, format_ip $host, $port); |
528 |
} |
529 |
}); |
530 |
|
531 |
defined wantarray |
532 |
? guard { %state = () } # clear fh and watcher, which breaks the circular dependency |
533 |
: () |
534 |
} |
535 |
|
536 |
1; |
537 |
|
538 |
=back |
539 |
|
540 |
=head1 AUTHOR |
541 |
|
542 |
Marc Lehmann <schmorp@schmorp.de> |
543 |
http://home.schmorp.de/ |
544 |
|
545 |
=cut |
546 |
|