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Upgrade Socket from version 2.019 to 2.020
[perl5.git] / cpan / Socket / Socket.pm
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a0d0e21e 1package Socket;
73c78b0a 2
e71d7b85 3use strict;
9dea6244 4{ use 5.006001; }
e71d7b85 5
50e79584 6our $VERSION = '2.020';
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7
8=head1 NAME
9
c2654555 10C<Socket> - networking constants and support functions
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11
12=head1 SYNOPSIS
13
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14C<Socket> a low-level module used by, among other things, the L<IO::Socket>
15family of modules. The following examples demonstrate some low-level uses but
16a practical program would likely use the higher-level API provided by
17C<IO::Socket> or similar instead.
18
19 use Socket qw(PF_INET SOCK_STREAM pack_sockaddr_in inet_aton);
20
21 socket(my $socket, PF_INET, SOCK_STREAM, 0)
22 or die "socket: $!";
23
24 my $port = getservbyname "echo", "tcp";
25 connect($socket, pack_sockaddr_in($port, inet_aton("localhost")))
26 or die "connect: $!";
27
28 print $socket "Hello, world!\n";
29 print <$socket>;
30
31See also the L</EXAMPLES> section.
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32
33=head1 DESCRIPTION
34
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35This module provides a variety of constants, structure manipulators and other
36functions related to socket-based networking. The values and functions
37provided are useful when used in conjunction with Perl core functions such as
38socket(), setsockopt() and bind(). It also provides several other support
39functions, mostly for dealing with conversions of network addresses between
40human-readable and native binary forms, and for hostname resolver operations.
3b35bae3 41
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42Some constants and functions are exported by default by this module; but for
43backward-compatibility any recently-added symbols are not exported by default
44and must be requested explicitly. When an import list is provided to the
45C<use Socket> line, the default exports are not automatically imported. It is
46therefore best practice to always to explicitly list all the symbols required.
fdb41d65 47
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48Also, some common socket "newline" constants are provided: the constants
49C<CR>, C<LF>, and C<CRLF>, as well as C<$CR>, C<$LF>, and C<$CRLF>, which map
50to C<\015>, C<\012>, and C<\015\012>. If you do not want to use the literal
51characters in your programs, then use the constants provided here. They are
52not exported by default, but can be imported individually, and with the
53C<:crlf> export tag:
fdb41d65 54
c2654555 55 use Socket qw(:DEFAULT :crlf);
8e07c86e 56
c2654555 57 $sock->print("GET / HTTP/1.0$CRLF");
2ae324a7 58
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59The entire getaddrinfo() subsystem can be exported using the tag C<:addrinfo>;
60this exports the getaddrinfo() and getnameinfo() functions, and all the
61C<AI_*>, C<NI_*>, C<NIx_*> and C<EAI_*> constants.
8e07c86e 62
c2654555 63=cut
8e07c86e 64
c2654555 65=head1 CONSTANTS
2528d3bc 66
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67In each of the following groups, there may be many more constants provided
68than just the ones given as examples in the section heading. If the heading
69ends C<...> then this means there are likely more; the exact constants
70provided will depend on the OS and headers found at compile-time.
8e07c86e 71
c2654555 72=cut
8e07c86e 73
c2654555 74=head2 PF_INET, PF_INET6, PF_UNIX, ...
8e07c86e 75
c2654555 76Protocol family constants to use as the first argument to socket() or the
eabcd9c8 77value of the C<SO_DOMAIN> or C<SO_FAMILY> socket option.
8e07c86e 78
c2654555 79=head2 AF_INET, AF_INET6, AF_UNIX, ...
8e07c86e 80
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81Address family constants used by the socket address structures, to pass to
82such functions as inet_pton() or getaddrinfo(), or are returned by such
83functions as sockaddr_family().
7e1af8bc 84
c2654555 85=head2 SOCK_STREAM, SOCK_DGRAM, SOCK_RAW, ...
7e1af8bc 86
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87Socket type constants to use as the second argument to socket(), or the value
88of the C<SO_TYPE> socket option.
7e1af8bc 89
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90=head2 SOCK_NONBLOCK. SOCK_CLOEXEC
91
92Linux-specific shortcuts to specify the C<O_NONBLOCK> and C<FD_CLOEXEC> flags
93during a C<socket(2)> call.
94
95 socket( my $sockh, PF_INET, SOCK_DGRAM|SOCK_NONBLOCK, 0 )
96
c2654555 97=head2 SOL_SOCKET
8e07c86e 98
c2654555 99Socket option level constant for setsockopt() and getsockopt().
8e07c86e 100
c2654555 101=head2 SO_ACCEPTCONN, SO_BROADCAST, SO_ERROR, ...
3b35bae3 102
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103Socket option name constants for setsockopt() and getsockopt() at the
104C<SOL_SOCKET> level.
8e07c86e 105
c2654555 106=head2 IP_OPTIONS, IP_TOS, IP_TTL, ...
8e07c86e 107
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108Socket option name constants for IPv4 socket options at the C<IPPROTO_IP>
109level.
8e07c86e 110
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111=head2 IPTOS_LOWDELAY, IPTOS_THROUGHPUT, IPTOS_RELIABILITY, ...
112
113Socket option value constants for C<IP_TOS> socket option.
114
c2654555 115=head2 MSG_BCAST, MSG_OOB, MSG_TRUNC, ...
d3f248d3 116
c2654555 117Message flag constants for send() and recv().
d3f248d3 118
c2654555 119=head2 SHUT_RD, SHUT_RDWR, SHUT_WR
d3f248d3 120
c2654555 121Direction constants for shutdown().
d3f248d3 122
c2654555 123=head2 INADDR_ANY, INADDR_BROADCAST, INADDR_LOOPBACK, INADDR_NONE
2a84dff3 124
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125Constants giving the special C<AF_INET> addresses for wildcard, broadcast,
126local loopback, and invalid addresses.
127
128Normally equivalent to inet_aton('0.0.0.0'), inet_aton('255.255.255.255'),
129inet_aton('localhost') and inet_aton('255.255.255.255') respectively.
130
131=head2 IPPROTO_IP, IPPROTO_IPV6, IPPROTO_TCP, ...
132
133IP protocol constants to use as the third argument to socket(), the level
134argument to getsockopt() or setsockopt(), or the value of the C<SO_PROTOCOL>
135socket option.
136
137=head2 TCP_CORK, TCP_KEEPALIVE, TCP_NODELAY, ...
138
139Socket option name constants for TCP socket options at the C<IPPROTO_TCP>
140level.
141
142=head2 IN6ADDR_ANY, IN6ADDR_LOOPBACK
143
144Constants giving the special C<AF_INET6> addresses for wildcard and local
145loopback.
146
147Normally equivalent to inet_pton(AF_INET6, "::") and
148inet_pton(AF_INET6, "::1") respectively.
149
150=head2 IPV6_ADD_MEMBERSHIP, IPV6_MTU, IPV6_V6ONLY, ...
151
152Socket option name constants for IPv6 socket options at the C<IPPROTO_IPV6>
153level.
154
155=cut
156
157# Still undocumented: SCM_*, SOMAXCONN, IOV_MAX, UIO_MAXIOV
158
159=head1 STRUCTURE MANIPULATORS
160
161The following functions convert between lists of Perl values and packed binary
162strings representing structures.
163
164=cut
2a84dff3 165
c2654555 166=head2 $family = sockaddr_family $sockaddr
4633a7c4 167
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168Takes a packed socket address (as returned by pack_sockaddr_in(),
169pack_sockaddr_un() or the perl builtin functions getsockname() and
170getpeername()). Returns the address family tag. This will be one of the
171C<AF_*> constants, such as C<AF_INET> for a C<sockaddr_in> addresses or
172C<AF_UNIX> for a C<sockaddr_un>. It can be used to figure out what unpack to
173use for a sockaddr of unknown type.
4633a7c4 174
c2654555 175=head2 $sockaddr = pack_sockaddr_in $port, $ip_address
4633a7c4 176
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177Takes two arguments, a port number and an opaque string (as returned by
178inet_aton(), or a v-string). Returns the C<sockaddr_in> structure with those
179arguments packed in and C<AF_INET> filled in. For Internet domain sockets,
180this structure is normally what you need for the arguments in bind(),
181connect(), and send().
8e07c86e 182
c2654555 183=head2 ($port, $ip_address) = unpack_sockaddr_in $sockaddr
8e07c86e 184
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185Takes a C<sockaddr_in> structure (as returned by pack_sockaddr_in(),
186getpeername() or recv()). Returns a list of two elements: the port and an
187opaque string representing the IP address (you can use inet_ntoa() to convert
188the address to the four-dotted numeric format). Will croak if the structure
189does not represent an C<AF_INET> address.
8e07c86e 190
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191In scalar context will return just the IP address.
192
c2654555 193=head2 $sockaddr = sockaddr_in $port, $ip_address
4633a7c4 194
c2654555 195=head2 ($port, $ip_address) = sockaddr_in $sockaddr
4bc6101e 196
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197A wrapper of pack_sockaddr_in() or unpack_sockaddr_in(). In list context,
198unpacks its argument and returns a list consisting of the port and IP address.
199In scalar context, packs its port and IP address arguments as a C<sockaddr_in>
200and returns it.
4bc6101e 201
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202Provided largely for legacy compatibility; it is better to use
203pack_sockaddr_in() or unpack_sockaddr_in() explicitly.
4bc6101e 204
c2654555 205=head2 $sockaddr = pack_sockaddr_in6 $port, $ip6_address, [$scope_id, [$flowinfo]]
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206
207Takes two to four arguments, a port number, an opaque string (as returned by
208inet_pton()), optionally a scope ID number, and optionally a flow label
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209number. Returns the C<sockaddr_in6> structure with those arguments packed in
210and C<AF_INET6> filled in. IPv6 equivalent of pack_sockaddr_in().
211
212=head2 ($port, $ip6_address, $scope_id, $flowinfo) = unpack_sockaddr_in6 $sockaddr
213
214Takes a C<sockaddr_in6> structure. Returns a list of four elements: the port
215number, an opaque string representing the IPv6 address, the scope ID, and the
216flow label. (You can use inet_ntop() to convert the address to the usual
217string format). Will croak if the structure does not represent an C<AF_INET6>
218address.
219
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220In scalar context will return just the IP address.
221
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222=head2 $sockaddr = sockaddr_in6 $port, $ip6_address, [$scope_id, [$flowinfo]]
223
224=head2 ($port, $ip6_address, $scope_id, $flowinfo) = sockaddr_in6 $sockaddr
225
226A wrapper of pack_sockaddr_in6() or unpack_sockaddr_in6(). In list context,
227unpacks its argument according to unpack_sockaddr_in6(). In scalar context,
228packs its arguments according to pack_sockaddr_in6().
229
230Provided largely for legacy compatibility; it is better to use
231pack_sockaddr_in6() or unpack_sockaddr_in6() explicitly.
232
233=head2 $sockaddr = pack_sockaddr_un $path
234
235Takes one argument, a pathname. Returns the C<sockaddr_un> structure with that
236path packed in with C<AF_UNIX> filled in. For C<PF_UNIX> sockets, this
237structure is normally what you need for the arguments in bind(), connect(),
238and send().
239
240=head2 ($path) = unpack_sockaddr_un $sockaddr
241
242Takes a C<sockaddr_un> structure (as returned by pack_sockaddr_un(),
243getpeername() or recv()). Returns a list of one element: the pathname. Will
244croak if the structure does not represent an C<AF_UNIX> address.
c73aa44c 245
c2654555 246=head2 $sockaddr = sockaddr_un $path
c73aa44c 247
c2654555 248=head2 ($path) = sockaddr_un $sockaddr
c73aa44c 249
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250A wrapper of pack_sockaddr_un() or unpack_sockaddr_un(). In a list context,
251unpacks its argument and returns a list consisting of the pathname. In a
252scalar context, packs its pathname as a C<sockaddr_un> and returns it.
4633a7c4 253
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254Provided largely for legacy compatibility; it is better to use
255pack_sockaddr_un() or unpack_sockaddr_un() explicitly.
4633a7c4 256
1fef88e7 257These are only supported if your system has E<lt>F<sys/un.h>E<gt>.
4633a7c4 258
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259=head2 $ip_mreq = pack_ip_mreq $multiaddr, $interface
260
261Takes an IPv4 multicast address and optionally an interface address (or
262C<INADDR_ANY>). Returns the C<ip_mreq> structure with those arguments packed
263in. Suitable for use with the C<IP_ADD_MEMBERSHIP> and C<IP_DROP_MEMBERSHIP>
264sockopts.
265
266=head2 ($multiaddr, $interface) = unpack_ip_mreq $ip_mreq
c2654555 267
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268Takes an C<ip_mreq> structure. Returns a list of two elements; the IPv4
269multicast address and interface address.
c2654555 270
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271=head2 $ip_mreq_source = pack_ip_mreq_source $multiaddr, $source, $interface
272
273Takes an IPv4 multicast address, source address, and optionally an interface
274address (or C<INADDR_ANY>). Returns the C<ip_mreq_source> structure with those
275arguments packed in. Suitable for use with the C<IP_ADD_SOURCE_MEMBERSHIP>
276and C<IP_DROP_SOURCE_MEMBERSHIP> sockopts.
277
278=head2 ($multiaddr, $source, $interface) = unpack_ip_mreq_source $ip_mreq
279
280Takes an C<ip_mreq_source> structure. Returns a list of three elements; the
281IPv4 multicast address, source address and interface address.
282
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283=head2 $ipv6_mreq = pack_ipv6_mreq $multiaddr6, $ifindex
284
285Takes an IPv6 multicast address and an interface number. Returns the
286C<ipv6_mreq> structure with those arguments packed in. Suitable for use with
287the C<IPV6_ADD_MEMBERSHIP> and C<IPV6_DROP_MEMBERSHIP> sockopts.
288
289=head2 ($multiaddr6, $ifindex) = unpack_ipv6_mreq $ipv6_mreq
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290
291Takes an C<ipv6_mreq> structure. Returns a list of two elements; the IPv6
292address and an interface number.
293
294=cut
295
296=head1 FUNCTIONS
297
298=cut
299
300=head2 $ip_address = inet_aton $string
301
302Takes a string giving the name of a host, or a textual representation of an IP
303address and translates that to an packed binary address structure suitable to
304pass to pack_sockaddr_in(). If passed a hostname that cannot be resolved,
305returns C<undef>. For multi-homed hosts (hosts with more than one address),
306the first address found is returned.
4633a7c4 307
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308For portability do not assume that the result of inet_aton() is 32 bits wide,
309in other words, that it would contain only the IPv4 address in network order.
4633a7c4 310
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311This IPv4-only function is provided largely for legacy reasons. Newly-written
312code should use getaddrinfo() or inet_pton() instead for IPv6 support.
4633a7c4 313
c2654555 314=head2 $string = inet_ntoa $ip_address
3b35bae3 315
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316Takes a packed binary address structure such as returned by
317unpack_sockaddr_in() (or a v-string representing the four octets of the IPv4
318address in network order) and translates it into a string of the form
319C<d.d.d.d> where the C<d>s are numbers less than 256 (the normal
320human-readable four dotted number notation for Internet addresses).
036d8bd4 321
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322This IPv4-only function is provided largely for legacy reasons. Newly-written
323code should use getnameinfo() or inet_ntop() instead for IPv6 support.
036d8bd4 324
c2654555 325=head2 $address = inet_pton $family, $string
d6896be3 326
c2654555 327Takes an address family (such as C<AF_INET> or C<AF_INET6>) and a string
23296748 328containing a textual representation of an address in that family and
c2654555 329translates that to an packed binary address structure.
036d8bd4 330
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331See also getaddrinfo() for a more powerful and flexible function to look up
332socket addresses given hostnames or textual addresses.
036d8bd4 333
c2654555 334=head2 $string = inet_ntop $family, $address
d6896be3 335
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336Takes an address family and a packed binary address structure and translates
337it into a human-readable textual representation of the address; typically in
338C<d.d.d.d> form for C<AF_INET> or C<hhhh:hhhh::hhhh> form for C<AF_INET6>.
e57a891d 339
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340See also getnameinfo() for a more powerful and flexible function to turn
341socket addresses into human-readable textual representations.
e57a891d 342
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343=head2 ($err, @result) = getaddrinfo $host, $service, [$hints]
344
345Given both a hostname and service name, this function attempts to resolve the
346host name into a list of network addresses, and the service name into a
347protocol and port number, and then returns a list of address structures
348suitable to connect() to it.
349
350Given just a host name, this function attempts to resolve it to a list of
351network addresses, and then returns a list of address structures giving these
352addresses.
353
354Given just a service name, this function attempts to resolve it to a protocol
355and port number, and then returns a list of address structures that represent
356it suitable to bind() to. This use should be combined with the C<AI_PASSIVE>
357flag; see below.
358
359Given neither name, it generates an error.
360
361If present, $hints should be a reference to a hash, where the following keys
362are recognised:
363
364=over 4
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365
366=item flags => INT
367
c2654555 368A bitfield containing C<AI_*> constants; see below.
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369
370=item family => INT
371
372Restrict to only generating addresses in this address family
373
374=item socktype => INT
375
376Restrict to only generating addresses of this socket type
377
378=item protocol => INT
379
380Restrict to only generating addresses for this protocol
381
382=back
383
384The return value will be a list; the first value being an error indication,
c2654555 385followed by a list of address structures (if no error occurred).
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386
387The error value will be a dualvar; comparable to the C<EI_*> error constants,
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388or printable as a human-readable error message string. If no error occurred it
389will be zero numerically and an empty string.
390
391Each value in the results list will be a hash reference containing the following
392fields:
e57a891d 393
c2654555 394=over 4
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395
396=item family => INT
397
c2654555 398The address family (e.g. C<AF_INET>)
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399
400=item socktype => INT
401
c2654555 402The socket type (e.g. C<SOCK_STREAM>)
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403
404=item protocol => INT
405
c2654555 406The protocol (e.g. C<IPPROTO_TCP>)
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407
408=item addr => STRING
409
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410The address in a packed string (such as would be returned by
411pack_sockaddr_in())
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412
413=item canonname => STRING
414
415The canonical name for the host if the C<AI_CANONNAME> flag was provided, or
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416C<undef> otherwise. This field will only be present on the first returned
417address.
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418
419=back
420
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421The following flag constants are recognised in the $hints hash. Other flag
422constants may exist as provided by the OS.
423
424=over 4
425
426=item AI_PASSIVE
e57a891d 427
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428Indicates that this resolution is for a local bind() for a passive (i.e.
429listening) socket, rather than an active (i.e. connecting) socket.
430
431=item AI_CANONNAME
432
433Indicates that the caller wishes the canonical hostname (C<canonname>) field
434of the result to be filled in.
435
436=item AI_NUMERICHOST
437
438Indicates that the caller will pass a numeric address, rather than a hostname,
439and that getaddrinfo() must not perform a resolve operation on this name. This
440flag will prevent a possibly-slow network lookup operation, and instead return
441an error if a hostname is passed.
442
443=back
444
445=head2 ($err, $hostname, $servicename) = getnameinfo $sockaddr, [$flags, [$xflags]]
446
447Given a packed socket address (such as from getsockname(), getpeername(), or
448returned by getaddrinfo() in a C<addr> field), returns the hostname and
449symbolic service name it represents. $flags may be a bitmask of C<NI_*>
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450constants, or defaults to 0 if unspecified.
451
452The return value will be a list; the first value being an error condition,
453followed by the hostname and service name.
454
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455The error value will be a dualvar; comparable to the C<EI_*> error constants,
456or printable as a human-readable error message string. The host and service
457names will be plain strings.
458
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459The following flag constants are recognised as $flags. Other flag constants may
460exist as provided by the OS.
461
462=over 4
463
464=item NI_NUMERICHOST
465
466Requests that a human-readable string representation of the numeric address be
467returned directly, rather than performing a name resolve operation that may
468convert it into a hostname. This will also avoid potentially-blocking network
469IO.
470
471=item NI_NUMERICSERV
472
473Requests that the port number be returned directly as a number representation
474rather than performing a name resolve operation that may convert it into a
475service name.
476
477=item NI_NAMEREQD
478
479If a name resolve operation fails to provide a name, then this flag will cause
480getnameinfo() to indicate an error, rather than returning the numeric
481representation as a human-readable string.
482
483=item NI_DGRAM
484
485Indicates that the socket address relates to a C<SOCK_DGRAM> socket, for the
486services whose name differs between TCP and UDP protocols.
487
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488=back
489
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490The following constants may be supplied as $xflags.
491
492=over 4
4f5bb87f 493
c2654555 494=item NIx_NOHOST
4f5bb87f 495
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496Indicates that the caller is not interested in the hostname of the result, so
497it does not have to be converted. C<undef> will be returned as the hostname.
4f5bb87f 498
c2654555 499=item NIx_NOSERV
4f5bb87f 500
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501Indicates that the caller is not interested in the service name of the result,
502so it does not have to be converted. C<undef> will be returned as the service
503name.
504
505=back
506
507=head1 getaddrinfo() / getnameinfo() ERROR CONSTANTS
508
509The following constants may be returned by getaddrinfo() or getnameinfo().
510Others may be provided by the OS.
511
512=over 4
513
514=item EAI_AGAIN
515
516A temporary failure occurred during name resolution. The operation may be
517successful if it is retried later.
518
519=item EAI_BADFLAGS
520
521The value of the C<flags> hint to getaddrinfo(), or the $flags parameter to
522getnameinfo() contains unrecognised flags.
523
524=item EAI_FAMILY
525
526The C<family> hint to getaddrinfo(), or the family of the socket address
527passed to getnameinfo() is not supported.
528
529=item EAI_NODATA
530
531The host name supplied to getaddrinfo() did not provide any usable address
532data.
533
534=item EAI_NONAME
535
536The host name supplied to getaddrinfo() does not exist, or the address
537supplied to getnameinfo() is not associated with a host name and the
538C<NI_NAMEREQD> flag was supplied.
539
540=item EAI_SERVICE
541
542The service name supplied to getaddrinfo() is not available for the socket
543type given in the $hints.
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544
545=back
546
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547=cut
548
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549=head1 EXAMPLES
550
551=head2 Lookup for connect()
552
553The getaddrinfo() function converts a hostname and a service name into a list
554of structures, each containing a potential way to connect() to the named
555service on the named host.
556
557 use IO::Socket;
558 use Socket qw(SOCK_STREAM getaddrinfo);
559
560 my %hints = (socktype => SOCK_STREAM);
561 my ($err, @res) = getaddrinfo("localhost", "echo", \%hints);
562 die "Cannot getaddrinfo - $err" if $err;
563
564 my $sock;
565
566 foreach my $ai (@res) {
567 my $candidate = IO::Socket->new();
568
569 $candidate->socket($ai->{family}, $ai->{socktype}, $ai->{protocol})
570 or next;
571
572 $candidate->connect($ai->{addr})
573 or next;
574
575 $sock = $candidate;
576 last;
577 }
578
579 die "Cannot connect to localhost:echo" unless $sock;
580
581 $sock->print("Hello, world!\n");
582 print <$sock>;
583
584Because a list of potential candidates is returned, the C<while> loop tries
a5c69419
AP
585each in turn until it finds one that succeeds both the socket() and connect()
586calls.
c2654555
CBW
587
588This function performs the work of the legacy functions gethostbyname(),
589getservbyname(), inet_aton() and pack_sockaddr_in().
590
591In practice this logic is better performed by L<IO::Socket::IP>.
592
593=head2 Making a human-readable string out of an address
594
595The getnameinfo() function converts a socket address, such as returned by
596getsockname() or getpeername(), into a pair of human-readable strings
597representing the address and service name.
598
599 use IO::Socket::IP;
600 use Socket qw(getnameinfo);
601
602 my $server = IO::Socket::IP->new(LocalPort => 12345, Listen => 1) or
603 die "Cannot listen - $@";
604
605 my $socket = $server->accept or die "accept: $!";
606
607 my ($err, $hostname, $servicename) = getnameinfo($socket->peername);
608 die "Cannot getnameinfo - $err" if $err;
609
610 print "The peer is connected from $hostname\n";
611
612Since in this example only the hostname was used, the redundant conversion of
613the port number into a service name may be omitted by passing the
614C<NIx_NOSERV> flag.
615
616 use Socket qw(getnameinfo NIx_NOSERV);
617
618 my ($err, $hostname) = getnameinfo($socket->peername, 0, NIx_NOSERV);
619
620This function performs the work of the legacy functions unpack_sockaddr_in(),
621inet_ntoa(), gethostbyaddr() and getservbyport().
622
623In practice this logic is better performed by L<IO::Socket::IP>.
624
625=head2 Resolving hostnames into IP addresses
626
627To turn a hostname into a human-readable plain IP address use getaddrinfo()
628to turn the hostname into a list of socket structures, then getnameinfo() on
629each one to make it a readable IP address again.
630
631 use Socket qw(:addrinfo SOCK_RAW);
632
633 my ($err, @res) = getaddrinfo($hostname, "", {socktype => SOCK_RAW});
634 die "Cannot getaddrinfo - $err" if $err;
635
636 while( my $ai = shift @res ) {
637 my ($err, $ipaddr) = getnameinfo($ai->{addr}, NI_NUMERICHOST, NIx_NOSERV);
638 die "Cannot getnameinfo - $err" if $err;
639
640 print "$ipaddr\n";
641 }
642
643The C<socktype> hint to getaddrinfo() filters the results to only include one
644socket type and protocol. Without this most OSes return three combinations,
645for C<SOCK_STREAM>, C<SOCK_DGRAM> and C<SOCK_RAW>, resulting in triplicate
646output of addresses. The C<NI_NUMERICHOST> flag to getnameinfo() causes it to
647return a string-formatted plain IP address, rather than reverse resolving it
648back into a hostname.
649
650This combination performs the work of the legacy functions gethostbyname()
651and inet_ntoa().
652
653=head2 Accessing socket options
654
655The many C<SO_*> and other constants provide the socket option names for
656getsockopt() and setsockopt().
657
658 use IO::Socket::INET;
659 use Socket qw(SOL_SOCKET SO_RCVBUF IPPROTO_IP IP_TTL);
660
661 my $socket = IO::Socket::INET->new(LocalPort => 0, Proto => 'udp')
662 or die "Cannot create socket: $@";
663
664 $socket->setsockopt(SOL_SOCKET, SO_RCVBUF, 64*1024) or
665 die "setsockopt: $!";
666
667 print "Receive buffer is ", $socket->getsockopt(SOL_SOCKET, SO_RCVBUF),
668 " bytes\n";
669
670 print "IP TTL is ", $socket->getsockopt(IPPROTO_IP, IP_TTL), "\n";
671
672As a convenience, L<IO::Socket>'s setsockopt() method will convert a number
673into a packed byte buffer, and getsockopt() will unpack a byte buffer of the
674correct size back into a number.
675
676=cut
677
678=head1 AUTHOR
679
680This module was originally maintained in Perl core by the Perl 5 Porters.
681
682It was extracted to dual-life on CPAN at version 1.95 by
683Paul Evans <leonerd@leonerd.org.uk>
684
685=cut
686
a0d0e21e 687use Carp;
d3a7d8c7 688use warnings::register;
a0d0e21e
LW
689
690require Exporter;
da4061d3 691require XSLoader;
c2654555 692our @ISA = qw(Exporter);
80531fbd
LB
693
694# <@Nicholas> you can't change @EXPORT without breaking the implicit API
695# Please put any new constants in @EXPORT_OK!
c2654555
CBW
696
697# List re-ordered to match documentation above. Try to keep the ordering
698# consistent so it's easier to see which ones are or aren't documented.
699our @EXPORT = qw(
700 PF_802 PF_AAL PF_APPLETALK PF_CCITT PF_CHAOS PF_CTF PF_DATAKIT
701 PF_DECnet PF_DLI PF_ECMA PF_GOSIP PF_HYLINK PF_IMPLINK PF_INET PF_INET6
702 PF_ISO PF_KEY PF_LAST PF_LAT PF_LINK PF_MAX PF_NBS PF_NIT PF_NS PF_OSI
703 PF_OSINET PF_PUP PF_ROUTE PF_SNA PF_UNIX PF_UNSPEC PF_USER PF_WAN
a0d0e21e 704 PF_X25
c2654555
CBW
705
706 AF_802 AF_AAL AF_APPLETALK AF_CCITT AF_CHAOS AF_CTF AF_DATAKIT
707 AF_DECnet AF_DLI AF_ECMA AF_GOSIP AF_HYLINK AF_IMPLINK AF_INET AF_INET6
708 AF_ISO AF_KEY AF_LAST AF_LAT AF_LINK AF_MAX AF_NBS AF_NIT AF_NS AF_OSI
709 AF_OSINET AF_PUP AF_ROUTE AF_SNA AF_UNIX AF_UNSPEC AF_USER AF_WAN
710 AF_X25
711
712 SOCK_DGRAM SOCK_RAW SOCK_RDM SOCK_SEQPACKET SOCK_STREAM
713
a0d0e21e 714 SOL_SOCKET
c2654555
CBW
715
716 SO_ACCEPTCONN SO_ATTACH_FILTER SO_BACKLOG SO_BROADCAST SO_CHAMELEON
eabcd9c8
A
717 SO_DEBUG SO_DETACH_FILTER SO_DGRAM_ERRIND SO_DOMAIN SO_DONTLINGER
718 SO_DONTROUTE SO_ERROR SO_FAMILY SO_KEEPALIVE SO_LINGER SO_OOBINLINE
719 SO_PASSCRED SO_PASSIFNAME SO_PEERCRED SO_PROTOCOL SO_PROTOTYPE
720 SO_RCVBUF SO_RCVLOWAT SO_RCVTIMEO SO_REUSEADDR SO_REUSEPORT
c2654555
CBW
721 SO_SECURITY_AUTHENTICATION SO_SECURITY_ENCRYPTION_NETWORK
722 SO_SECURITY_ENCRYPTION_TRANSPORT SO_SNDBUF SO_SNDLOWAT SO_SNDTIMEO
723 SO_STATE SO_TYPE SO_USELOOPBACK SO_XOPEN SO_XSE
724
725 IP_OPTIONS IP_HDRINCL IP_TOS IP_TTL IP_RECVOPTS IP_RECVRETOPTS
726 IP_RETOPTS
727
728 MSG_BCAST MSG_BTAG MSG_CTLFLAGS MSG_CTLIGNORE MSG_CTRUNC MSG_DONTROUTE
729 MSG_DONTWAIT MSG_EOF MSG_EOR MSG_ERRQUEUE MSG_ETAG MSG_FIN
730 MSG_MAXIOVLEN MSG_MCAST MSG_NOSIGNAL MSG_OOB MSG_PEEK MSG_PROXY MSG_RST
731 MSG_SYN MSG_TRUNC MSG_URG MSG_WAITALL MSG_WIRE
732
733 SHUT_RD SHUT_RDWR SHUT_WR
734
735 INADDR_ANY INADDR_BROADCAST INADDR_LOOPBACK INADDR_NONE
736
737 SCM_CONNECT SCM_CREDENTIALS SCM_CREDS SCM_RIGHTS SCM_TIMESTAMP
738
a0d0e21e 739 SOMAXCONN
c2654555
CBW
740
741 IOV_MAX
6b1016b5 742 UIO_MAXIOV
c2654555
CBW
743
744 sockaddr_family
745 pack_sockaddr_in unpack_sockaddr_in sockaddr_in
746 pack_sockaddr_in6 unpack_sockaddr_in6 sockaddr_in6
747 pack_sockaddr_un unpack_sockaddr_un sockaddr_un
748
749 inet_aton inet_ntoa
750);
751
752# List re-ordered to match documentation above. Try to keep the ordering
753# consistent so it's easier to see which ones are or aren't documented.
754our @EXPORT_OK = qw(
755 CR LF CRLF $CR $LF $CRLF
756
3be135d8
TC
757 SOCK_NONBLOCK SOCK_CLOEXEC
758
d4ada64a
SH
759 IP_ADD_MEMBERSHIP IP_ADD_SOURCE_MEMBERSHIP IP_DROP_MEMBERSHIP
760 IP_DROP_SOURCE_MEMBERSHIP IP_MULTICAST_IF IP_MULTICAST_LOOP
761 IP_MULTICAST_TTL
3be135d8 762
50e79584
SH
763 IPPROTO_IP IPPROTO_IPV6 IPPROTO_RAW IPPROTO_ICMP IPPROTO_IGMP
764 IPPROTO_TCP IPPROTO_UDP IPPROTO_GRE IPPROTO_ESP IPPROTO_AH
765 IPPROTO_SCTP
c2654555 766
a5c69419
AP
767 IPTOS_LOWDELAY IPTOS_THROUGHPUT IPTOS_RELIABILITY IPTOS_MINCOST
768
d4ada64a
SH
769 TCP_CONGESTION TCP_CONNECTIONTIMEOUT TCP_CORK TCP_DEFER_ACCEPT TCP_INFO
770 TCP_INIT_CWND TCP_KEEPALIVE TCP_KEEPCNT TCP_KEEPIDLE TCP_KEEPINTVL
771 TCP_LINGER2 TCP_MAXRT TCP_MAXSEG TCP_MD5SIG TCP_NODELAY TCP_NOOPT
772 TCP_NOPUSH TCP_QUICKACK TCP_SACK_ENABLE TCP_STDURG TCP_SYNCNT
773 TCP_WINDOW_CLAMP
c2654555
CBW
774
775 IN6ADDR_ANY IN6ADDR_LOOPBACK
776
d4ada64a
SH
777 IPV6_ADD_MEMBERSHIP IPV6_DROP_MEMBERSHIP IPV6_JOIN_GROUP
778 IPV6_LEAVE_GROUP IPV6_MTU IPV6_MTU_DISCOVER IPV6_MULTICAST_HOPS
779 IPV6_MULTICAST_IF IPV6_MULTICAST_LOOP IPV6_UNICAST_HOPS IPV6_V6ONLY
c2654555 780
d4ada64a 781 pack_ip_mreq unpack_ip_mreq pack_ip_mreq_source unpack_ip_mreq_source
3be135d8 782
c2654555
CBW
783 pack_ipv6_mreq unpack_ipv6_mreq
784
785 inet_pton inet_ntop
786
787 getaddrinfo getnameinfo
788
789 AI_ADDRCONFIG AI_ALL AI_CANONIDN AI_CANONNAME AI_IDN
790 AI_IDN_ALLOW_UNASSIGNED AI_IDN_USE_STD3_ASCII_RULES AI_NUMERICHOST
791 AI_NUMERICSERV AI_PASSIVE AI_V4MAPPED
792
793 NI_DGRAM NI_IDN NI_IDN_ALLOW_UNASSIGNED NI_IDN_USE_STD3_ASCII_RULES
794 NI_NAMEREQD NI_NOFQDN NI_NUMERICHOST NI_NUMERICSERV
795
796 NIx_NOHOST NIx_NOSERV
797
798 EAI_ADDRFAMILY EAI_AGAIN EAI_BADFLAGS EAI_BADHINTS EAI_FAIL EAI_FAMILY
799 EAI_NODATA EAI_NONAME EAI_PROTOCOL EAI_SERVICE EAI_SOCKTYPE EAI_SYSTEM
a0d0e21e
LW
800);
801
c2654555
CBW
802our %EXPORT_TAGS = (
803 crlf => [qw(CR LF CRLF $CR $LF $CRLF)],
804 addrinfo => [qw(getaddrinfo getnameinfo), grep m/^(?:AI|NI|NIx|EAI)_/, @EXPORT_OK],
805 all => [@EXPORT, @EXPORT_OK],
fdb41d65
CN
806);
807
808BEGIN {
809 sub CR () {"\015"}
810 sub LF () {"\012"}
811 sub CRLF () {"\015\012"}
c2654555
CBW
812
813 # These are not gni() constants; they're extensions for the perl API
814 # The definitions in Socket.pm and Socket.xs must match
815 sub NIx_NOHOST() {1 << 0}
816 sub NIx_NOSERV() {1 << 1}
fdb41d65
CN
817}
818
819*CR = \CR();
820*LF = \LF();
821*CRLF = \CRLF();
822
4633a7c4
LW
823sub sockaddr_in {
824 if (@_ == 6 && !wantarray) { # perl5.001m compat; use this && die
825 my($af, $port, @quad) = @_;
c2654555 826 warnings::warn "6-ARG sockaddr_in call is deprecated"
d3a7d8c7 827 if warnings::enabled();
4633a7c4
LW
828 pack_sockaddr_in($port, inet_aton(join('.', @quad)));
829 } elsif (wantarray) {
830 croak "usage: (port,iaddr) = sockaddr_in(sin_sv)" unless @_ == 1;
831 unpack_sockaddr_in(@_);
832 } else {
833 croak "usage: sin_sv = sockaddr_in(port,iaddr))" unless @_ == 2;
834 pack_sockaddr_in(@_);
835 }
836}
837
4bc6101e
PE
838sub sockaddr_in6 {
839 if (wantarray) {
840 croak "usage: (port,in6addr,scope_id,flowinfo) = sockaddr_in6(sin6_sv)" unless @_ == 1;
841 unpack_sockaddr_in6(@_);
842 }
843 else {
844 croak "usage: sin6_sv = sockaddr_in6(port,in6addr,[scope_id,[flowinfo]])" unless @_ >= 2 and @_ <= 4;
845 pack_sockaddr_in6(@_);
846 }
847}
848
4633a7c4
LW
849sub sockaddr_un {
850 if (wantarray) {
851 croak "usage: (filename) = sockaddr_un(sun_sv)" unless @_ == 1;
852 unpack_sockaddr_un(@_);
853 } else {
37120919
AD
854 croak "usage: sun_sv = sockaddr_un(filename)" unless @_ == 1;
855 pack_sockaddr_un(@_);
4633a7c4
LW
856 }
857}
858
4c3d8e12 859XSLoader::load(__PACKAGE__, $VERSION);
a0d0e21e 860
c2219427
PLE
861my %errstr;
862
32b40adf
NC
863if( defined &getaddrinfo ) {
864 # These are not part of the API, nothing uses them, and deleting them
865 # reduces the size of %Socket:: by about 12K
866 delete $Socket::{fake_getaddrinfo};
867 delete $Socket::{fake_getnameinfo};
868} else {
0f41f5e2
PLE
869 require Scalar::Util;
870
871 *getaddrinfo = \&fake_getaddrinfo;
872 *getnameinfo = \&fake_getnameinfo;
873
874 # These numbers borrowed from GNU libc's implementation, but since
875 # they're only used by our emulation, it doesn't matter if the real
876 # platform's values differ
877 my %constants = (
878 AI_PASSIVE => 1,
879 AI_CANONNAME => 2,
880 AI_NUMERICHOST => 4,
0369a5a5
PLE
881 AI_V4MAPPED => 8,
882 AI_ALL => 16,
883 AI_ADDRCONFIG => 32,
0f41f5e2
PLE
884 # RFC 2553 doesn't define this but Linux does - lets be nice and
885 # provide it since we can
886 AI_NUMERICSERV => 1024,
887
888 EAI_BADFLAGS => -1,
889 EAI_NONAME => -2,
890 EAI_NODATA => -5,
891 EAI_FAMILY => -6,
892 EAI_SERVICE => -8,
893
894 NI_NUMERICHOST => 1,
895 NI_NUMERICSERV => 2,
0369a5a5 896 NI_NOFQDN => 4,
0f41f5e2
PLE
897 NI_NAMEREQD => 8,
898 NI_DGRAM => 16,
0369a5a5
PLE
899
900 # Constants we don't support. Export them, but croak if anyone tries to
901 # use them
902 AI_IDN => 64,
903 AI_CANONIDN => 128,
904 AI_IDN_ALLOW_UNASSIGNED => 256,
905 AI_IDN_USE_STD3_ASCII_RULES => 512,
906 NI_IDN => 32,
907 NI_IDN_ALLOW_UNASSIGNED => 64,
908 NI_IDN_USE_STD3_ASCII_RULES => 128,
909
910 # Error constants we'll never return, so it doesn't matter what value
911 # these have, nor that we don't provide strings for them
912 EAI_SYSTEM => -11,
913 EAI_BADHINTS => -1000,
914 EAI_PROTOCOL => -1001
0f41f5e2
PLE
915 );
916
917 foreach my $name ( keys %constants ) {
918 my $value = $constants{$name};
919
920 no strict 'refs';
921 defined &$name or *$name = sub () { $value };
922 }
923
924 %errstr = (
925 # These strings from RFC 2553
926 EAI_BADFLAGS() => "invalid value for ai_flags",
927 EAI_NONAME() => "nodename nor servname provided, or not known",
928 EAI_NODATA() => "no address associated with nodename",
929 EAI_FAMILY() => "ai_family not supported",
930 EAI_SERVICE() => "servname not supported for ai_socktype",
931 );
c2219427
PLE
932}
933
934# The following functions are used if the system does not have a
935# getaddrinfo(3) function in libc; and are used to emulate it for the AF_INET
936# family
937
c2219427 938# Borrowed from Regexp::Common::net
36998252 939my $REGEXP_IPv4_DECIMAL = qr/25[0-5]|2[0-4][0-9]|[0-1]?[0-9]{1,2}/;
c2219427
PLE
940my $REGEXP_IPv4_DOTTEDQUAD = qr/$REGEXP_IPv4_DECIMAL\.$REGEXP_IPv4_DECIMAL\.$REGEXP_IPv4_DECIMAL\.$REGEXP_IPv4_DECIMAL/;
941
942sub fake_makeerr
943{
0f41f5e2
PLE
944 my ( $errno ) = @_;
945 my $errstr = $errno == 0 ? "" : ( $errstr{$errno} || $errno );
946 return Scalar::Util::dualvar( $errno, $errstr );
c2219427
PLE
947}
948
949sub fake_getaddrinfo
950{
0f41f5e2
PLE
951 my ( $node, $service, $hints ) = @_;
952
953 $node = "" unless defined $node;
954
955 $service = "" unless defined $service;
956
957 my ( $family, $socktype, $protocol, $flags ) = @$hints{qw( family socktype protocol flags )};
958
959 $family ||= Socket::AF_INET(); # 0 == AF_UNSPEC, which we want too
960 $family == Socket::AF_INET() or return fake_makeerr( EAI_FAMILY() );
961
962 $socktype ||= 0;
963
964 $protocol ||= 0;
965
966 $flags ||= 0;
967
968 my $flag_passive = $flags & AI_PASSIVE(); $flags &= ~AI_PASSIVE();
969 my $flag_canonname = $flags & AI_CANONNAME(); $flags &= ~AI_CANONNAME();
970 my $flag_numerichost = $flags & AI_NUMERICHOST(); $flags &= ~AI_NUMERICHOST();
971 my $flag_numericserv = $flags & AI_NUMERICSERV(); $flags &= ~AI_NUMERICSERV();
972
0369a5a5
PLE
973 # These constants don't apply to AF_INET-only lookups, so we might as well
974 # just ignore them. For AI_ADDRCONFIG we just presume the host has ability
975 # to talk AF_INET. If not we'd have to return no addresses at all. :)
976 $flags &= ~(AI_V4MAPPED()|AI_ALL()|AI_ADDRCONFIG());
977
978 $flags & (AI_IDN()|AI_CANONIDN()|AI_IDN_ALLOW_UNASSIGNED()|AI_IDN_USE_STD3_ASCII_RULES()) and
979 croak "Socket::getaddrinfo() does not support IDN";
980
0f41f5e2
PLE
981 $flags == 0 or return fake_makeerr( EAI_BADFLAGS() );
982
983 $node eq "" and $service eq "" and return fake_makeerr( EAI_NONAME() );
984
985 my $canonname;
986 my @addrs;
987 if( $node ne "" ) {
988 return fake_makeerr( EAI_NONAME() ) if( $flag_numerichost and $node !~ m/^$REGEXP_IPv4_DOTTEDQUAD$/ );
989 ( $canonname, undef, undef, undef, @addrs ) = gethostbyname( $node );
990 defined $canonname or return fake_makeerr( EAI_NONAME() );
991
992 undef $canonname unless $flag_canonname;
993 }
994 else {
995 $addrs[0] = $flag_passive ? Socket::inet_aton( "0.0.0.0" )
996 : Socket::inet_aton( "127.0.0.1" );
997 }
998
999 my @ports; # Actually ARRAYrefs of [ socktype, protocol, port ]
1000 my $protname = "";
1001 if( $protocol ) {
c6d5e127 1002 $protname = eval { getprotobynumber( $protocol ) };
0f41f5e2
PLE
1003 }
1004
1005 if( $service ne "" and $service !~ m/^\d+$/ ) {
1006 return fake_makeerr( EAI_NONAME() ) if( $flag_numericserv );
1007 getservbyname( $service, $protname ) or return fake_makeerr( EAI_SERVICE() );
1008 }
1009
1010 foreach my $this_socktype ( Socket::SOCK_STREAM(), Socket::SOCK_DGRAM(), Socket::SOCK_RAW() ) {
1011 next if $socktype and $this_socktype != $socktype;
1012
1013 my $this_protname = "raw";
1014 $this_socktype == Socket::SOCK_STREAM() and $this_protname = "tcp";
1015 $this_socktype == Socket::SOCK_DGRAM() and $this_protname = "udp";
1016
1017 next if $protname and $this_protname ne $protname;
1018
1019 my $port;
1020 if( $service ne "" ) {
1021 if( $service =~ m/^\d+$/ ) {
1022 $port = "$service";
1023 }
1024 else {
1025 ( undef, undef, $port, $this_protname ) = getservbyname( $service, $this_protname );
1026 next unless defined $port;
1027 }
1028 }
1029 else {
1030 $port = 0;
1031 }
1032
c6d5e127 1033 push @ports, [ $this_socktype, eval { scalar getprotobyname( $this_protname ) } || 0, $port ];
0f41f5e2
PLE
1034 }
1035
1036 my @ret;
1037 foreach my $addr ( @addrs ) {
1038 foreach my $portspec ( @ports ) {
1039 my ( $socktype, $protocol, $port ) = @$portspec;
1040 push @ret, {
1041 family => $family,
1042 socktype => $socktype,
1043 protocol => $protocol,
1044 addr => Socket::pack_sockaddr_in( $port, $addr ),
0cd14f2e 1045 canonname => undef,
0f41f5e2
PLE
1046 };
1047 }
1048 }
1049
0cd14f2e
PLE
1050 # Only supply canonname for the first result
1051 if( defined $canonname ) {
1052 $ret[0]->{canonname} = $canonname;
1053 }
1054
0f41f5e2 1055 return ( fake_makeerr( 0 ), @ret );
c2219427
PLE
1056}
1057
1058sub fake_getnameinfo
1059{
c2654555 1060 my ( $addr, $flags, $xflags ) = @_;
0f41f5e2
PLE
1061
1062 my ( $port, $inetaddr );
1063 eval { ( $port, $inetaddr ) = Socket::unpack_sockaddr_in( $addr ) }
1064 or return fake_makeerr( EAI_FAMILY() );
1065
1066 my $family = Socket::AF_INET();
1067
1068 $flags ||= 0;
1069
1070 my $flag_numerichost = $flags & NI_NUMERICHOST(); $flags &= ~NI_NUMERICHOST();
1071 my $flag_numericserv = $flags & NI_NUMERICSERV(); $flags &= ~NI_NUMERICSERV();
0369a5a5 1072 my $flag_nofqdn = $flags & NI_NOFQDN(); $flags &= ~NI_NOFQDN();
0f41f5e2
PLE
1073 my $flag_namereqd = $flags & NI_NAMEREQD(); $flags &= ~NI_NAMEREQD();
1074 my $flag_dgram = $flags & NI_DGRAM() ; $flags &= ~NI_DGRAM();
1075
0369a5a5
PLE
1076 $flags & (NI_IDN()|NI_IDN_ALLOW_UNASSIGNED()|NI_IDN_USE_STD3_ASCII_RULES()) and
1077 croak "Socket::getnameinfo() does not support IDN";
1078
0f41f5e2
PLE
1079 $flags == 0 or return fake_makeerr( EAI_BADFLAGS() );
1080
c2654555
CBW
1081 $xflags ||= 0;
1082
0f41f5e2 1083 my $node;
c2654555
CBW
1084 if( $xflags & NIx_NOHOST ) {
1085 $node = undef;
1086 }
1087 elsif( $flag_numerichost ) {
0f41f5e2
PLE
1088 $node = Socket::inet_ntoa( $inetaddr );
1089 }
1090 else {
1091 $node = gethostbyaddr( $inetaddr, $family );
1092 if( !defined $node ) {
1093 return fake_makeerr( EAI_NONAME() ) if $flag_namereqd;
1094 $node = Socket::inet_ntoa( $inetaddr );
1095 }
0369a5a5
PLE
1096 elsif( $flag_nofqdn ) {
1097 my ( $shortname ) = split m/\./, $node;
1098 my ( $fqdn ) = gethostbyname $shortname;
1099 $node = $shortname if defined $fqdn and $fqdn eq $node;
1100 }
0f41f5e2
PLE
1101 }
1102
1103 my $service;
c2654555
CBW
1104 if( $xflags & NIx_NOSERV ) {
1105 $service = undef;
1106 }
1107 elsif( $flag_numericserv ) {
0f41f5e2
PLE
1108 $service = "$port";
1109 }
1110 else {
1111 my $protname = $flag_dgram ? "udp" : "";
1112 $service = getservbyport( $port, $protname );
1113 if( !defined $service ) {
1114 $service = "$port";
1115 }
1116 }
1117
1118 return ( fake_makeerr( 0 ), $node, $service );
c2219427
PLE
1119}
1120
a0d0e21e 11211;