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Revision 1.7 by root, Fri May 23 17:47:06 2008 UTC vs.
Revision 1.63 by root, Wed Oct 1 07:40:39 2008 UTC

2 2
3AnyEvent::Socket - useful IPv4 and IPv6 stuff. 3AnyEvent::Socket - useful IPv4 and IPv6 stuff.
4 4
5=head1 SYNOPSIS 5=head1 SYNOPSIS
6 6
7 use AnyEvent::Socket; 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 };
8 22
9=head1 DESCRIPTION 23=head1 DESCRIPTION
10 24
11This module implements various utility functions for handling internet 25This module implements various utility functions for handling internet
12protocol addresses and sockets, in an as transparent and simple way as 26protocol addresses and sockets, in an as transparent and simple way as
24no warnings; 38no warnings;
25use strict; 39use strict;
26 40
27use Carp (); 41use Carp ();
28use Errno (); 42use Errno ();
29use Socket (); 43use Socket qw(AF_INET AF_UNIX SOCK_STREAM SOCK_DGRAM SOL_SOCKET SO_REUSEADDR);
30 44
31use AnyEvent (); 45use AnyEvent ();
32use AnyEvent::Util qw(guard fh_nonblocking); 46use AnyEvent::Util qw(guard fh_nonblocking AF_INET6);
47use AnyEvent::DNS ();
33 48
34use base 'Exporter'; 49use base 'Exporter';
35 50
36BEGIN { 51our @EXPORT = qw(
37 *socket_inet_aton = \&Socket::inet_aton; # take a copy, in case Coro::LWP overrides it 52 parse_hostport
38} 53 parse_ipv4 parse_ipv6
54 parse_ip parse_address
55 format_ip format_address
56 address_family
57 inet_aton
58 tcp_server
59 tcp_connect
60);
39 61
40our @EXPORT = qw(inet_aton tcp_server tcp_connect);
41
42our $VERSION = '1.0'; 62our $VERSION = 4.3;
43 63
44sub dotted_quad($) { 64=item $ipn = parse_ipv4 $dotted_quad
45 $_[0] =~ /^(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[0-9][0-9]?) 65
46 \.(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[0-9][0-9]?) 66Tries to parse the given dotted quad IPv4 address and return it in
47 \.(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[0-9][0-9]?) 67octet form (or undef when it isn't in a parsable format). Supports all
48 \.(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[0-9][0-9]?)$/x 68forms specified by POSIX (e.g. C<10.0.0.1>, C<10.1>, C<10.0x020304>,
69C<0x12345678> or C<0377.0377.0377.0377>).
70
71=cut
72
73sub parse_ipv4($) {
74 $_[0] =~ /^ (?: 0x[0-9a-fA-F]+ | 0[0-7]* | [1-9][0-9]* )
75 (?:\. (?: 0x[0-9a-fA-F]+ | 0[0-7]* | [1-9][0-9]* ) ){0,3}$/x
76 or return undef;
77
78 @_ = map /^0/ ? oct : $_, split /\./, $_[0];
79
80 # check leading parts against range
81 return undef if grep $_ >= 256, @_[0 .. @_ - 2];
82
83 # check trailing part against range
84 return undef if $_[-1] >= 2 ** (8 * (4 - $#_));
85
86 pack "N", (pop)
87 + ($_[0] << 24)
88 + ($_[1] << 16)
89 + ($_[2] << 8);
49} 90}
91
92=item $ipn = parse_ipv6 $textual_ipv6_address
93
94Tries to parse the given IPv6 address and return it in
95octet form (or undef when it isn't in a parsable format).
96
97Should support all forms specified by RFC 2373 (and additionally all IPv4
98forms supported by parse_ipv4). Note that scope-id's are not supported
99(and will not parse).
100
101This function works similarly to C<inet_pton AF_INET6, ...>.
102
103=cut
104
105sub parse_ipv6($) {
106 # quick test to avoid longer processing
107 my $n = $_[0] =~ y/://;
108 return undef if $n < 2 || $n > 8;
109
110 my ($h, $t) = split /::/, $_[0], 2;
111
112 unless (defined $t) {
113 ($h, $t) = (undef, $h);
114 }
115
116 my @h = split /:/, $h;
117 my @t = split /:/, $t;
118
119 # check for ipv4 tail
120 if (@t && $t[-1]=~ /\./) {
121 return undef if $n > 6;
122
123 my $ipn = parse_ipv4 pop @t
124 or return undef;
125
126 push @t, map +(sprintf "%x", $_), unpack "nn", $ipn;
127 }
128
129 # no :: then we need to have exactly 8 components
130 return undef unless @h + @t == 8 || $_[0] =~ /::/;
131
132 # now check all parts for validity
133 return undef if grep !/^[0-9a-fA-F]{1,4}$/, @h, @t;
134
135 # now pad...
136 push @h, 0 while @h + @t < 8;
137
138 # and done
139 pack "n*", map hex, @h, @t
140}
141
142sub parse_unix($) {
143 $_[0] eq "unix/"
144 ? pack "S", AF_UNIX
145 : undef
146
147}
148
149=item $ipn = parse_address $text
150
151Combines C<parse_ipv4> and C<parse_ipv6> in one function. The address
152here refers to the host address (not socket address) in network form
153(binary).
154
155If the C<$text> is C<unix/>, then this function returns a special token
156recognised by the other functions in this module to mean "UNIX domain
157socket".
158
159=item $text = AnyEvent::Socket::aton $ipn
160
161Same as C<parse_address>, but not exported (think C<Socket::inet_aton> but
162I<without> name resolution).
163
164=cut
165
166sub parse_address($) {
167 &parse_ipv4 || &parse_ipv6 || &parse_unix
168}
169
170*aton = \&parse_address;
171
172=item ($host, $service) = parse_hostport $string[, $default_service]
173
174Splitting a string of the form C<hostname:port> is a common
175problem. Unfortunately, just splitting on the colon makes it hard to
176specify IPv6 addresses and doesn't support the less common but well
177standardised C<[ip literal]> syntax.
178
179This function tries to do this job in a better way, it supports the
180following formats, where C<port> can be a numerical port number of a
181service name, or a C<name=port> string, and the C< port> and C<:port>
182parts are optional. Also, everywhere where an IP address is supported
183a hostname or unix domain socket address is also supported (see
184C<parse_unix>).
185
186 hostname:port e.g. "www.linux.org", "www.x.de:443", "www.x.de:https=443"
187 ipv4:port e.g. "198.182.196.56", "127.1:22"
188 ipv6 e.g. "::1", "affe::1"
189 [ipv4or6]:port e.g. "[::1]", "[10.0.1]:80"
190 [ipv4or6] port e.g. "[127.0.0.1]", "[www.x.org] 17"
191 ipv4or6 port e.g. "::1 443", "10.0.0.1 smtp"
192
193It also supports defaulting the service name in a simple way by using
194C<$default_service> if no service was detected. If neither a service was
195detected nor a default was specified, then this function returns the
196empty list. The same happens when a parse error weas detected, such as a
197hostname with a colon in it (the function is rather conservative, though).
198
199Example:
200
201 print join ",", parse_hostport "localhost:443";
202 # => "localhost,443"
203
204 print join ",", parse_hostport "localhost", "https";
205 # => "localhost,https"
206
207 print join ",", parse_hostport "[::1]";
208 # => "," (empty list)
209
210=cut
211
212sub parse_hostport($;$) {
213 my ($host, $port);
214
215 for ("$_[0]") { # work on a copy, just in case, and also reset pos
216
217 # parse host, special cases: "ipv6" or "ipv6 port"
218 unless (
219 ($host) = /^\s* ([0-9a-fA-F:]*:[0-9a-fA-F:]*:[0-9a-fA-F\.:]*)/xgc
220 and parse_ipv6 $host
221 ) {
222 /^\s*/xgc;
223
224 if (/^ \[ ([^\[\]]+) \]/xgc) {
225 $host = $1;
226 } elsif (/^ ([^\[\]:\ ]+) /xgc) {
227 $host = $1;
228 } else {
229 return;
230 }
231 }
232
233 # parse port
234 if (/\G (?:\s+|:) ([^:[:space:]]+) \s*$/xgc) {
235 $port = $1;
236 } elsif (/\G\s*$/gc && length $_[1]) {
237 $port = $_[1];
238 } else {
239 return;
240 }
241 }
242
243 # hostnames must not contain :'s
244 return if $host =~ /:/ && !parse_ipv6 $host;
245
246 ($host, $port)
247}
248
249=item $sa_family = address_family $ipn
250
251Returns the address family/protocol-family (AF_xxx/PF_xxx, in one value :)
252of the given host address in network format.
253
254=cut
255
256sub address_family($) {
257 4 == length $_[0]
258 ? AF_INET
259 : 16 == length $_[0]
260 ? AF_INET6
261 : unpack "S", $_[0]
262}
263
264=item $text = format_address $ipn
265
266Covnvert a host address in network format (e.g. 4 octets for IPv4 or 16
267octets for IPv6) and convert it into textual form.
268
269Returns C<unix/> for UNIX domain sockets.
270
271This function works similarly to C<inet_ntop AF_INET || AF_INET6, ...>,
272except it automatically detects the address type.
273
274Returns C<undef> if it cannot detect the type.
275
276=item $text = AnyEvent::Socket::ntoa $ipn
277
278Same as format_address, but not exported (think C<inet_ntoa>).
279
280=cut
281
282sub format_address;
283sub format_address($) {
284 my $af = address_family $_[0];
285 if ($af == AF_INET) {
286 return join ".", unpack "C4", $_[0]
287 } elsif ($af == AF_INET6) {
288 if (v0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0 eq $_[0]) {
289 return "::";
290 } elsif (v0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.1 eq $_[0]) {
291 return "::1";
292 } elsif (v0.0.0.0.0.0.0.0.0.0.0.0 eq substr $_[0], 0, 12) {
293 # v4compatible
294 return "::" . format_address substr $_[0], 12;
295 } elsif (v0.0.0.0.0.0.0.0.0.0.255.255 eq substr $_[0], 0, 12) {
296 # v4mapped
297 return "::ffff:" . format_address substr $_[0], 12;
298 } elsif (v0.0.0.0.0.0.0.0.255.255.0.0 eq substr $_[0], 0, 12) {
299 # v4translated
300 return "::ffff:0:" . format_address substr $_[0], 12;
301 } else {
302 my $ip = sprintf "%x:%x:%x:%x:%x:%x:%x:%x", unpack "n8", $_[0];
303
304 # this is rather sucky, I admit
305 $ip =~ s/^0:(?:0:)*(0$)?/::/
306 or $ip =~ s/(:0){7}$/::/ or $ip =~ s/(:0){7}/:/
307 or $ip =~ s/(:0){6}$/::/ or $ip =~ s/(:0){6}/:/
308 or $ip =~ s/(:0){5}$/::/ or $ip =~ s/(:0){5}/:/
309 or $ip =~ s/(:0){4}$/::/ or $ip =~ s/(:0){4}/:/
310 or $ip =~ s/(:0){3}$/::/ or $ip =~ s/(:0){3}/:/
311 or $ip =~ s/(:0){2}$/::/ or $ip =~ s/(:0){2}/:/
312 or $ip =~ s/(:0){1}$/::/ or $ip =~ s/(:0){1}/:/;
313 return $ip
314 }
315 } elsif ($af == AF_UNIX) {
316 return "unix/"
317 } else {
318 return undef
319 }
320}
321
322*ntoa = \&format_address;
50 323
51=item inet_aton $name_or_address, $cb->(@addresses) 324=item inet_aton $name_or_address, $cb->(@addresses)
52 325
53Works similarly to its Socket counterpart, except that it uses a 326Works similarly to its Socket counterpart, except that it uses a
54callback. Also, if a host has only an IPv6 address, this might be passed 327callback. Also, if a host has only an IPv6 address, this might be passed
55to the callback instead (use the length to detect this - 4 for IPv4, 16 328to the callback instead (use the length to detect this - 4 for IPv4, 16
56for IPv6). 329for IPv6).
57 330
58Unlike the L<Socket> function of the same name, you can get multiple IPv4 331Unlike the L<Socket> function of the same name, you can get multiple IPv4
59and IPv6 addresses as result. 332and IPv6 addresses as result (and maybe even other adrdess types).
60 333
61=cut 334=cut
62 335
63sub inet_aton { 336sub inet_aton {
64 my ($name, $cb) = @_; 337 my ($name, $cb) = @_;
65 338
66 if (&dotted_quad) { 339 if (my $ipn = &parse_ipv4) {
67 $cb->(socket_inet_aton $name); 340 $cb->($ipn);
341 } elsif (my $ipn = &parse_ipv6) {
342 $cb->($ipn);
68 } elsif ($name eq "localhost") { # rfc2606 et al. 343 } elsif ($name eq "localhost") { # rfc2606 et al.
69 $cb->(v127.0.0.1); 344 $cb->(v127.0.0.1, v0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.1);
70 } else { 345 } else {
71 require AnyEvent::DNS; 346 require AnyEvent::DNS;
72 347
73 # simple, bad suboptimal algorithm 348 # simple, bad suboptimal algorithm
74 AnyEvent::DNS::a ($name, sub { 349 AnyEvent::DNS::a ($name, sub {
75 if (@_) { 350 if (@_) {
76 &$cb; 351 $cb->(map +(parse_ipv4 $_), @_);
77 } else { 352 } else {
353 $cb->();
78 AnyEvent::DNS::aaaa ($name, $cb); 354 #AnyEvent::DNS::aaaa ($name, $cb); need inet_pton
79 } 355 }
80 }); 356 });
81 } 357 }
82} 358}
83 359
84sub _tcp_port($) { 360# check for broken platforms with extra field in sockaddr structure
85 $_[0] =~ /^(\d*)$/ and return $1*1; 361# kind of a rfc vs. bsd issue, as usual (ok, normally it's a
362# unix vs. bsd issue, a iso C vs. bsd issue or simply a
363# correctness vs. bsd issue.
364my $pack_family = (0x55 == Socket::sockaddr_family "\x55\x55")
365 ? "xC" : "S";
86 366
87 (getservbyname $_[0], "tcp")[2] 367=item $sa = AnyEvent::Socket::pack_sockaddr $service, $host
368
369Pack the given port/host combination into a binary sockaddr
370structure. Handles both IPv4 and IPv6 host addresses, as well as UNIX
371domain sockets (C<$host> == C<unix/> and C<$service> == absolute
372pathname).
373
374=cut
375
376sub pack_sockaddr($$) {
377 my $af = address_family $_[1];
378
379 if ($af == AF_INET) {
380 Socket::pack_sockaddr_in $_[0], $_[1]
381 } elsif ($af == AF_INET6) {
382 pack "$pack_family nL a16 L",
383 AF_INET6,
384 $_[0], # port
385 0, # flowinfo
386 $_[1], # addr
387 0 # scope id
388 } elsif ($af == AF_UNIX) {
389 Socket::pack_sockaddr_un $_[0]
390 } else {
391 Carp::croak "pack_sockaddr: invalid host";
392 }
393}
394
395=item ($service, $host) = AnyEvent::Socket::unpack_sockaddr $sa
396
397Unpack the given binary sockaddr structure (as used by bind, getpeername
398etc.) into a C<$service, $host> combination.
399
400For IPv4 and IPv6, C<$service> is the port number and C<$host> the host
401address in network format (binary).
402
403For UNIX domain sockets, C<$service> is the absolute pathname and C<$host>
404is a special token that is understood by the other functions in this
405module (C<format_address> converts it to C<unix/>).
406
407=cut
408
409sub unpack_sockaddr($) {
410 my $af = Socket::sockaddr_family $_[0];
411
412 if ($af == AF_INET) {
413 Socket::unpack_sockaddr_in $_[0]
414 } elsif ($af == AF_INET6) {
415 unpack "x2 n x4 a16", $_[0]
416 } elsif ($af == AF_UNIX) {
417 ((Socket::unpack_sockaddr_un $_[0]), pack "S", AF_UNIX)
418 } else {
419 Carp::croak "unpack_sockaddr: unsupported protocol family $af";
420 }
421}
422
423=item resolve_sockaddr $node, $service, $proto, $family, $type, $cb->([$family, $type, $proto, $sockaddr], ...)
424
425Tries to resolve the given nodename and service name into protocol families
426and sockaddr structures usable to connect to this node and service in a
427protocol-independent way. It works remotely similar to the getaddrinfo
428posix function.
429
430For internet addresses, C<$node> is either an IPv4 or IPv6 address or an
431internet hostname, and C<$service> is either a service name (port name
432from F</etc/services>) or a numerical port number. If both C<$node> and
433C<$service> are names, then SRV records will be consulted to find the real
434service, otherwise they will be used as-is. If you know that the service
435name is not in your services database, then you can specify the service in
436the format C<name=port> (e.g. C<http=80>).
437
438For UNIX domain sockets, C<$node> must be the string C<unix/> and
439C<$service> must be the absolute pathname of the socket. In this case,
440C<$proto> will be ignored.
441
442C<$proto> must be a protocol name, currently C<tcp>, C<udp> or
443C<sctp>. The default is currently C<tcp>, but in the future, this function
444might try to use other protocols such as C<sctp>, depending on the socket
445type and any SRV records it might find.
446
447C<$family> must be either C<0> (meaning any protocol is OK), C<4> (use
448only IPv4) or C<6> (use only IPv6). This setting might be influenced by
449C<$ENV{PERL_ANYEVENT_PROTOCOLS}>.
450
451C<$type> must be C<SOCK_STREAM>, C<SOCK_DGRAM> or C<SOCK_SEQPACKET> (or
452C<undef> in which case it gets automatically chosen).
453
454The callback will receive zero or more array references that contain
455C<$family, $type, $proto> for use in C<socket> and a binary
456C<$sockaddr> for use in C<connect> (or C<bind>).
457
458The application should try these in the order given.
459
460Example:
461
462 resolve_sockaddr "google.com", "http", 0, undef, undef, sub { ... };
463
464=cut
465
466# microsoft can't even get getprotobyname working (the etc/protocols file
467# gets lost fairly often on windows), so we have to hardcode some common
468# protocol numbers ourselves.
469our %PROTO_BYNAME;
470
471$PROTO_BYNAME{tcp} = &Socket::IPPROTO_TCP if defined &Socket::IPPROTO_TCP;
472$PROTO_BYNAME{udp} = &Socket::IPPROTO_UDP if defined &Socket::IPPROTO_UDP;
473$PROTO_BYNAME{icmp} = &Socket::IPPROTO_ICMP if defined &Socket::IPPROTO_ICMP;
474
475sub resolve_sockaddr($$$$$$) {
476 my ($node, $service, $proto, $family, $type, $cb) = @_;
477
478 if ($node eq "unix/") {
479 return $cb->() if $family || !/^\//; # no can do
480
481 return $cb->([AF_UNIX, $type, 0, Socket::pack_sockaddr_un $service]);
482 }
483
484 unless (AF_INET6) {
485 $family != 6
486 or return $cb->();
487
488 $family = 4;
489 }
490
491 $cb->() if $family == 4 && !$AnyEvent::PROTOCOL{ipv4};
492 $cb->() if $family == 6 && !$AnyEvent::PROTOCOL{ipv6};
493
494 $family ||= 4 unless $AnyEvent::PROTOCOL{ipv6};
495 $family ||= 6 unless $AnyEvent::PROTOCOL{ipv4};
496
497 $proto ||= "tcp";
498 $type ||= $proto eq "udp" ? SOCK_DGRAM : SOCK_STREAM;
499
500 my $proton = $PROTO_BYNAME{lc $proto} || (getprotobyname $proto)[2]
88 or Carp::croak "$_[0]: service unknown" 501 or Carp::croak "$proto: protocol unknown";
89}
90 502
503 my $port;
504
505 if ($service =~ /^(\S+)=(\d+)$/) {
506 ($service, $port) = ($1, $2);
507 } elsif ($service =~ /^\d+$/) {
508 ($service, $port) = (undef, $service);
509 } else {
510 $port = (getservbyname $service, $proto)[2]
511 or Carp::croak "$service/$proto: service unknown";
512 }
513
514 my @target = [$node, $port];
515
516 # resolve a records / provide sockaddr structures
517 my $resolve = sub {
518 my @res;
519 my $cv = AnyEvent->condvar (cb => sub {
520 $cb->(
521 map $_->[2],
522 sort {
523 $AnyEvent::PROTOCOL{$b->[1]} <=> $AnyEvent::PROTOCOL{$a->[1]}
524 or $a->[0] <=> $b->[0]
525 }
526 @res
527 )
528 });
529
530 $cv->begin;
531 for my $idx (0 .. $#target) {
532 my ($node, $port) = @{ $target[$idx] };
533
534 if (my $noden = parse_address $node) {
535 my $af = address_family $noden;
536
537 if ($af == AF_INET && $family != 6) {
538 push @res, [$idx, "ipv4", [AF_INET, $type, $proton,
539 pack_sockaddr $port, $noden]]
540 }
541
542 if ($af == AF_INET6 && $family != 4) {
543 push @res, [$idx, "ipv6", [AF_INET6, $type, $proton,
544 pack_sockaddr $port, $noden]]
545 }
546 } else {
547 # ipv4
548 if ($family != 6) {
549 $cv->begin;
550 AnyEvent::DNS::a $node, sub {
551 push @res, [$idx, "ipv4", [AF_INET, $type, $proton,
552 pack_sockaddr $port, parse_ipv4 $_]]
553 for @_;
554 $cv->end;
555 };
556 }
557
558 # ipv6
559 if ($family != 4) {
560 $cv->begin;
561 AnyEvent::DNS::aaaa $node, sub {
562 push @res, [$idx, "ipv6", [AF_INET6, $type, $proton,
563 pack_sockaddr $port, parse_ipv6 $_]]
564 for @_;
565 $cv->end;
566 };
567 }
568 }
569 }
570 $cv->end;
571 };
572
573 # try srv records, if applicable
574 if ($node eq "localhost") {
575 @target = (["127.0.0.1", $port], ["::1", $port]);
576 &$resolve;
577 } elsif (defined $service && !parse_address $node) {
578 AnyEvent::DNS::srv $service, $proto, $node, sub {
579 my (@srv) = @_;
580
581 # no srv records, continue traditionally
582 @srv
583 or return &$resolve;
584
585 # the only srv record has "." ("" here) => abort
586 $srv[0][2] ne "" || $#srv
587 or return $cb->();
588
589 # use srv records then
590 @target = map ["$_->[3].", $_->[2]],
591 grep $_->[3] ne ".",
592 @srv;
593
594 &$resolve;
595 };
596 } else {
597 &$resolve;
598 }
599}
600
91=item $guard = tcp_connect $host, $port, $connect_cb[, $prepare_cb] 601=item $guard = tcp_connect $host, $service, $connect_cb[, $prepare_cb]
92 602
93This is a convenience function that creates a tcp socket and makes a 100% 603This is a convenience function that creates a TCP socket and makes a 100%
94non-blocking connect to the given C<$host> (which can be a hostname or a 604non-blocking connect to the given C<$host> (which can be a hostname or
95textual IP address) and C<$port> (which can be a numeric port number or a 605a textual IP address, or the string C<unix/> for UNIX domain sockets)
96service name). 606and C<$service> (which can be a numeric port number or a service name,
607or a C<servicename=portnumber> string, or the pathname to a UNIX domain
608socket).
97 609
98Unless called in void context, it returns a guard object that will 610If both C<$host> and C<$port> are names, then this function will use SRV
99automatically abort connecting when it gets destroyed (it does not do 611records to locate the real target(s).
100anything to the socket after the connect was successful). 612
613In either case, it will create a list of target hosts (e.g. for multihomed
614hosts or hosts with both IPv4 and IPv6 addresses) and try to connect to
615each in turn.
101 616
102If the connect is successful, then the C<$connect_cb> will be invoked with 617If the connect is successful, then the C<$connect_cb> will be invoked with
103the socket filehandle (in non-blocking mode) as first and the peer host 618the socket file handle (in non-blocking mode) as first and the peer host
104(as a textual IP address) and peer port as second and third arguments, 619(as a textual IP address) and peer port as second and third arguments,
105respectively. 620respectively. The fourth argument is a code reference that you can call
621if, for some reason, you don't like this connection, which will cause
622C<tcp_connect> to try the next one (or call your callback without any
623arguments if there are no more connections). In most cases, you can simply
624ignore this argument.
625
626 $cb->($filehandle, $host, $port, $retry)
106 627
107If the connect is unsuccessful, then the C<$connect_cb> will be invoked 628If the connect is unsuccessful, then the C<$connect_cb> will be invoked
108without any arguments and C<$!> will be set appropriately (with C<ENXIO> 629without any arguments and C<$!> will be set appropriately (with C<ENXIO>
109indicating a dns resolution failure). 630indicating a DNS resolution failure).
110 631
111The filehandle is suitable to be plugged into L<AnyEvent::Handle>, but can 632The file handle is perfect for being plugged into L<AnyEvent::Handle>, but
112be used as a normal perl file handle as well. 633can be used as a normal perl file handle as well.
634
635Unless called in void context, C<tcp_connect> returns a guard object that
636will automatically abort connecting when it gets destroyed (it does not do
637anything to the socket after the connect was successful).
113 638
114Sometimes you need to "prepare" the socket before connecting, for example, 639Sometimes you need to "prepare" the socket before connecting, for example,
115to C<bind> it to some port, or you want a specific connect timeout that 640to C<bind> it to some port, or you want a specific connect timeout that
116is lower than your kernel's default timeout. In this case you can specify 641is lower than your kernel's default timeout. In this case you can specify
117a second callback, C<$prepare_cb>. It will be called with the file handle 642a second callback, C<$prepare_cb>. It will be called with the file handle
118in not-yet-connected state as only argument and must return the connection 643in not-yet-connected state as only argument and must return the connection
119timeout value (or C<0>, C<undef> or the empty list to indicate the default 644timeout value (or C<0>, C<undef> or the empty list to indicate the default
120timeout is to be used). 645timeout is to be used).
121 646
122Note that the socket could be either a IPv4 TCP socket or an IPv6 tcp 647Note that the socket could be either a IPv4 TCP socket or an IPv6 TCP
123socket (although only IPv4 is currently supported by this module). 648socket (although only IPv4 is currently supported by this module).
124 649
650Note to the poor Microsoft Windows users: Windows (of course) doesn't
651correctly signal connection errors, so unless your event library works
652around this, failed connections will simply hang. The only event libraries
653that handle this condition correctly are L<EV> and L<Glib>. Additionally,
654AnyEvent works around this bug with L<Event> and in its pure-perl
655backend. All other libraries cannot correctly handle this condition. To
656lessen the impact of this windows bug, a default timeout of 30 seconds
657will be imposed on windows. Cygwin is not affected.
658
125Simple Example: connect to localhost on port 22. 659Simple Example: connect to localhost on port 22.
126 660
127 AnyEvent::Util::tcp_connect localhost => 22, sub { 661 tcp_connect localhost => 22, sub {
128 my $fh = shift 662 my $fh = shift
129 or die "unable to connect: $!"; 663 or die "unable to connect: $!";
130 # do something 664 # do something
131 }; 665 };
132 666
133Complex Example: connect to www.google.com on port 80 and make a simple 667Complex Example: connect to www.google.com on port 80 and make a simple
134GET request without much error handling. Also limit the connection timeout 668GET request without much error handling. Also limit the connection timeout
135to 15 seconds. 669to 15 seconds.
136 670
166 # could call $fh->bind etc. here 700 # could call $fh->bind etc. here
167 701
168 15 702 15
169 }; 703 };
170 704
705Example: connect to a UNIX domain socket.
706
707 tcp_connect "unix/", "/tmp/.X11-unix/X0", sub {
708 ...
709 }
710
171=cut 711=cut
172 712
173sub tcp_connect($$$;$) { 713sub tcp_connect($$$;$) {
174 my ($host, $port, $connect, $prepare) = @_; 714 my ($host, $port, $connect, $prepare) = @_;
175 715
176 # see http://cr.yp.to/docs/connect.html for some background 716 # see http://cr.yp.to/docs/connect.html for some background
717 # also http://advogato.org/article/672.html
177 718
178 my %state = ( fh => undef ); 719 my %state = ( fh => undef );
179 720
180 # name resolution 721 # name/service to type/sockaddr resolution
181 inet_aton $host, sub { 722 resolve_sockaddr $host, $port, 0, 0, 0, sub {
723 my @target = @_;
724
725 $state{next} = sub {
182 return unless exists $state{fh}; 726 return unless exists $state{fh};
183 727
184 my $ipn = shift; 728 my $target = shift @target
185
186 4 == length $ipn
187 or do { 729 or do {
188 %state = (); 730 %state = ();
189 $! = &Errno::ENXIO;
190 return $connect->(); 731 return $connect->();
732 };
733
734 my ($domain, $type, $proto, $sockaddr) = @$target;
735
736 # socket creation
737 socket $state{fh}, $domain, $type, $proto
738 or return $state{next}();
739
740 fh_nonblocking $state{fh}, 1;
741
742 my $timeout = $prepare && $prepare->($state{fh});
743
744 $timeout ||= 30 if AnyEvent::WIN32;
745
746 $state{to} = AnyEvent->timer (after => $timeout, cb => sub {
747 $! = &Errno::ETIMEDOUT;
748 $state{next}();
749 }) if $timeout;
750
751 # called when the connect was successful, which,
752 # in theory, could be the case immediately (but never is in practise)
753 my $connected = sub {
754 delete $state{ww};
755 delete $state{to};
756
757 # we are connected, or maybe there was an error
758 if (my $sin = getpeername $state{fh}) {
759 my ($port, $host) = unpack_sockaddr $sin;
760
761 my $guard = guard {
762 %state = ();
763 };
764
765 $connect->($state{fh}, format_address $host, $port, sub {
766 $guard->cancel;
767 $state{next}();
768 });
769 } else {
770 # dummy read to fetch real error code
771 sysread $state{fh}, my $buf, 1 if $! == &Errno::ENOTCONN;
772 $state{next}();
773 }
191 }; 774 };
192 775
193 # socket creation 776 # now connect
194 socket $state{fh}, &Socket::AF_INET, &Socket::SOCK_STREAM, 0 777 if (connect $state{fh}, $sockaddr) {
195 or do {
196 %state = ();
197 return $connect->();
198 };
199
200 fh_nonblocking $state{fh}, 1;
201
202 # prepare and optional timeout
203 if ($prepare) {
204 my $timeout = $prepare->($state{fh});
205
206 $state{to} = AnyEvent->timer (after => $timeout, cb => sub {
207 %state = ();
208 $! = &Errno::ETIMEDOUT;
209 $connect->(); 778 $connected->();
210 }) if $timeout; 779 } elsif ($! == &Errno::EINPROGRESS # POSIX
211 } 780 || $! == &Errno::EWOULDBLOCK
212 781 # WSAEINPROGRESS intentionally not checked - it means something else entirely
213 # called when the connect was successful, which, 782 || $! == AnyEvent::Util::WSAEINVAL # not convinced, but doesn't hurt
214 # in theory, could be the case immediately (but never is in practise) 783 || $! == AnyEvent::Util::WSAEWOULDBLOCK) {
215 my $connected = sub { 784 $state{ww} = AnyEvent->io (fh => $state{fh}, poll => 'w', cb => $connected);
216 my $fh = delete $state{fh};
217 %state = ();
218
219 # we are connected, or maybe there was an error
220 if (my $sin = getpeername $fh) {
221 my ($port, $host) = Socket::unpack_sockaddr_in $sin;
222 $connect->($fh, (Socket::inet_ntoa $host), $port);
223 } else { 785 } else {
224 # dummy read to fetch real error code 786 $state{next}();
225 sysread $fh, my $buf, 1 if $! == &Errno::ENOTCONN;
226 $connect->();
227 } 787 }
228 }; 788 };
229 789
230 # now connect 790 $! = &Errno::ENXIO;
231 if (connect $state{fh}, Socket::pack_sockaddr_in _tcp_port $port, $ipn) { 791 $state{next}();
232 $connected->();
233 } elsif ($! == &Errno::EINPROGRESS || $! == &Errno::EWOULDBLOCK) { # EINPROGRESS is POSIX
234 $state{ww} = AnyEvent->io (fh => $state{fh}, poll => 'w', cb => $connected);
235 } else {
236 %state = ();
237 $connect->();
238 }
239 }; 792 };
240 793
241 defined wantarray 794 defined wantarray && guard { %state = () }
242 ? guard { %state = () } # break any circular dependencies and unregister watchers
243 : ()
244} 795}
245 796
246=item $guard = tcp_server $host, $port, $accept_cb[, $prepare_cb] 797=item $guard = tcp_server $host, $service, $accept_cb[, $prepare_cb]
247 798
248Create and bind a tcp socket to the given host (any IPv4 host if undef, 799Create and bind a stream socket to the given host, and port, set the
249otherwise it must be an IPv4 or IPv6 address) and port (service name or 800SO_REUSEADDR flag (if applicable) and call C<listen>. Unlike the name
250numeric port number, or an ephemeral port if given as zero or undef), set 801implies, this function can also bind on UNIX domain sockets.
251the SO_REUSEADDR flag and call C<listen>.
252 802
803For internet sockets, C<$host> must be an IPv4 or IPv6 address (or
804C<undef>, in which case it binds either to C<0> or to C<::>, depending
805on whether IPv4 or IPv6 is the preferred protocol, and maybe to both in
806future versions, as applicable).
807
808To bind to the IPv4 wildcard address, use C<0>, to bind to the IPv6
809wildcard address, use C<::>.
810
811The port is specified by C<$service>, which must be either a service name or
812a numeric port number (or C<0> or C<undef>, in which case an ephemeral
813port will be used).
814
815For UNIX domain sockets, C<$host> must be C<unix/> and C<$service> must be
816the absolute pathname of the socket. This function will try to C<unlink>
817the socket before it tries to bind to it. See SECURITY CONSIDERATIONS,
818below.
819
253For each new connection that could be C<accept>ed, call the C<$accept_cb> 820For each new connection that could be C<accept>ed, call the C<<
254with the filehandle (in non-blocking mode) as first and the peer host and 821$accept_cb->($fh, $host, $port) >> with the file handle (in non-blocking
255port as second and third arguments (see C<tcp_connect> for details). 822mode) as first and the peer host and port as second and third arguments
823(see C<tcp_connect> for details).
256 824
257Croaks on any errors. 825Croaks on any errors it can detect before the listen.
258 826
259If called in non-void context, then this function returns a guard object 827If called in non-void context, then this function returns a guard object
260whose lifetime it tied to the tcp server: If the object gets destroyed, 828whose lifetime it tied to the TCP server: If the object gets destroyed,
261the server will be stopped (but existing accepted connections will 829the server will be stopped (but existing accepted connections will
262continue). 830continue).
263 831
264If you need more control over the listening socket, you can provide a 832If you need more control over the listening socket, you can provide a
265C<$prepare_cb>, which is called just before the C<listen ()> call, with 833C<< $prepare_cb->($fh, $host, $port) >>, which is called just before the
266the listen file handle as first argument. 834C<listen ()> call, with the listen file handle as first argument, and IP
835address and port number of the local socket endpoint as second and third
836arguments.
267 837
268It should return the length of the listen queue (or C<0> for the default). 838It should return the length of the listen queue (or C<0> for the default).
269 839
840Note to IPv6 users: RFC-compliant behaviour for IPv6 sockets listening on
841C<::> is to bind to both IPv6 and IPv4 addresses by default on dual-stack
842hosts. Unfortunately, only GNU/Linux seems to implement this properly, so
843if you want both IPv4 and IPv6 listening sockets you should create the
844IPv6 socket first and then attempt to bind on the IPv4 socket, but ignore
845any C<EADDRINUSE> errors.
846
270Example: bind on tcp port 8888 on the local machine and tell each client 847Example: bind on some TCP port on the local machine and tell each client
271to go away. 848to go away.
272 849
273 tcp_server undef, 8888, sub { 850 tcp_server undef, undef, sub {
274 my ($fh, $host, $port) = @_; 851 my ($fh, $host, $port) = @_;
275 852
276 syswrite $fh, "The internet is full, $host:$port. Go away!\015\012"; 853 syswrite $fh, "The internet is full, $host:$port. Go away!\015\012";
854 }, sub {
855 my ($fh, $thishost, $thisport) = @_;
856 warn "bound to $thishost, port $thisport\n";
277 }; 857 };
278 858
279=cut 859=cut
280 860
281sub tcp_server($$$;$) { 861sub tcp_server($$$;$) {
282 my ($host, $port, $accept, $prepare) = @_; 862 my ($host, $service, $accept, $prepare) = @_;
863
864 $host = $AnyEvent::PROTOCOL{ipv4} < $AnyEvent::PROTOCOL{ipv6} && AF_INET6
865 ? "::" : "0"
866 unless defined $host;
867
868 my $ipn = parse_address $host
869 or Carp::croak "AnyEvent::Socket::tcp_server: cannot parse '$host' as host address";
870
871 my $af = address_family $ipn;
283 872
284 my %state; 873 my %state;
285 874
286 socket $state{fh}, &Socket::AF_INET, &Socket::SOCK_STREAM, 0 875 # win32 perl is too stupid to get this right :/
876 Carp::croak "tcp_server/socket: address family not supported"
877 if AnyEvent::WIN32 && $af == AF_UNIX;
878
879 socket $state{fh}, $af, SOCK_STREAM, 0
287 or Carp::croak "socket: $!"; 880 or Carp::croak "tcp_server/socket: $!";
288 881
882 if ($af == AF_INET || $af == AF_INET6) {
289 setsockopt $state{fh}, &Socket::SOL_SOCKET, &Socket::SO_REUSEADDR, 1 883 setsockopt $state{fh}, SOL_SOCKET, SO_REUSEADDR, 1
290 or Carp::croak "so_reuseaddr: $!"; 884 or Carp::croak "tcp_server/so_reuseaddr: $!"
885 unless AnyEvent::WIN32; # work around windows bug
291 886
292 bind $state{fh}, Socket::pack_sockaddr_in _tcp_port $port, socket_inet_aton ($host || "0.0.0.0") 887 unless ($service =~ /^\d*$/) {
888 $service = (getservbyname $service, "tcp")[2]
889 or Carp::croak "$service: service unknown"
890 }
891 } elsif ($af == AF_UNIX) {
892 unlink $service;
893 }
894
895 bind $state{fh}, pack_sockaddr $service, $ipn
293 or Carp::croak "bind: $!"; 896 or Carp::croak "bind: $!";
294 897
295 fh_nonblocking $state{fh}, 1; 898 fh_nonblocking $state{fh}, 1;
296 899
297 my $len = ($prepare && $prepare->($state{fh})) || 128; 900 my $len;
901
902 if ($prepare) {
903 my ($service, $host) = unpack_sockaddr getsockname $state{fh};
904 $len = $prepare && $prepare->($state{fh}, format_address $host, $service);
905 }
906
907 $len ||= 128;
298 908
299 listen $state{fh}, $len 909 listen $state{fh}, $len
300 or Carp::croak "listen: $!"; 910 or Carp::croak "listen: $!";
301 911
302 $state{aw} = AnyEvent->io (fh => $state{fh}, poll => 'r', cb => sub { 912 $state{aw} = AnyEvent->io (fh => $state{fh}, poll => 'r', cb => sub {
303 # this closure keeps $state alive 913 # this closure keeps $state alive
304 while (my $peer = accept my $fh, $state{fh}) { 914 while (my $peer = accept my $fh, $state{fh}) {
305 fh_nonblocking $fh, 1; # POSIX requires inheritance, the outside world does not 915 fh_nonblocking $fh, 1; # POSIX requires inheritance, the outside world does not
916
306 my ($port, $host) = Socket::unpack_sockaddr_in $peer; 917 my ($service, $host) = unpack_sockaddr $peer;
307 $accept->($fh, (Socket::inet_ntoa $host), $port); 918 $accept->($fh, format_address $host, $service);
308 } 919 }
309 }); 920 });
310 921
311 defined wantarray 922 defined wantarray
312 ? guard { %state = () } # clear fh and watcher, which breaks the circular dependency 923 ? guard { %state = () } # clear fh and watcher, which breaks the circular dependency
315 926
3161; 9271;
317 928
318=back 929=back
319 930
931=head1 SECURITY CONSIDERATIONS
932
933This module is quite powerful, with with power comes the ability to abuse
934as well: If you accept "hostnames" and ports from untrusted sources,
935then note that this can be abused to delete files (host=C<unix/>). This
936is not really a problem with this module, however, as blindly accepting
937any address and protocol and trying to bind a server or connect to it is
938harmful in general.
939
320=head1 AUTHOR 940=head1 AUTHOR
321 941
322 Marc Lehmann <schmorp@schmorp.de> 942 Marc Lehmann <schmorp@schmorp.de>
323 http://home.schmorp.de/ 943 http://home.schmorp.de/
324 944

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