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Upgrade Socket to 2.002
[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
3be135d8 6our $VERSION = '2.002';
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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
c2654555 111=head2 MSG_BCAST, MSG_OOB, MSG_TRUNC, ...
d3f248d3 112
c2654555 113Message flag constants for send() and recv().
d3f248d3 114
c2654555 115=head2 SHUT_RD, SHUT_RDWR, SHUT_WR
d3f248d3 116
c2654555 117Direction constants for shutdown().
d3f248d3 118
c2654555 119=head2 INADDR_ANY, INADDR_BROADCAST, INADDR_LOOPBACK, INADDR_NONE
2a84dff3 120
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121Constants giving the special C<AF_INET> addresses for wildcard, broadcast,
122local loopback, and invalid addresses.
123
124Normally equivalent to inet_aton('0.0.0.0'), inet_aton('255.255.255.255'),
125inet_aton('localhost') and inet_aton('255.255.255.255') respectively.
126
127=head2 IPPROTO_IP, IPPROTO_IPV6, IPPROTO_TCP, ...
128
129IP protocol constants to use as the third argument to socket(), the level
130argument to getsockopt() or setsockopt(), or the value of the C<SO_PROTOCOL>
131socket option.
132
133=head2 TCP_CORK, TCP_KEEPALIVE, TCP_NODELAY, ...
134
135Socket option name constants for TCP socket options at the C<IPPROTO_TCP>
136level.
137
138=head2 IN6ADDR_ANY, IN6ADDR_LOOPBACK
139
140Constants giving the special C<AF_INET6> addresses for wildcard and local
141loopback.
142
143Normally equivalent to inet_pton(AF_INET6, "::") and
144inet_pton(AF_INET6, "::1") respectively.
145
146=head2 IPV6_ADD_MEMBERSHIP, IPV6_MTU, IPV6_V6ONLY, ...
147
148Socket option name constants for IPv6 socket options at the C<IPPROTO_IPV6>
149level.
150
151=cut
152
153# Still undocumented: SCM_*, SOMAXCONN, IOV_MAX, UIO_MAXIOV
154
155=head1 STRUCTURE MANIPULATORS
156
157The following functions convert between lists of Perl values and packed binary
158strings representing structures.
159
160=cut
2a84dff3 161
c2654555 162=head2 $family = sockaddr_family $sockaddr
4633a7c4 163
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164Takes a packed socket address (as returned by pack_sockaddr_in(),
165pack_sockaddr_un() or the perl builtin functions getsockname() and
166getpeername()). Returns the address family tag. This will be one of the
167C<AF_*> constants, such as C<AF_INET> for a C<sockaddr_in> addresses or
168C<AF_UNIX> for a C<sockaddr_un>. It can be used to figure out what unpack to
169use for a sockaddr of unknown type.
4633a7c4 170
c2654555 171=head2 $sockaddr = pack_sockaddr_in $port, $ip_address
4633a7c4 172
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173Takes two arguments, a port number and an opaque string (as returned by
174inet_aton(), or a v-string). Returns the C<sockaddr_in> structure with those
175arguments packed in and C<AF_INET> filled in. For Internet domain sockets,
176this structure is normally what you need for the arguments in bind(),
177connect(), and send().
8e07c86e 178
c2654555 179=head2 ($port, $ip_address) = unpack_sockaddr_in $sockaddr
8e07c86e 180
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181Takes a C<sockaddr_in> structure (as returned by pack_sockaddr_in(),
182getpeername() or recv()). Returns a list of two elements: the port and an
183opaque string representing the IP address (you can use inet_ntoa() to convert
184the address to the four-dotted numeric format). Will croak if the structure
185does not represent an C<AF_INET> address.
8e07c86e 186
c2654555 187=head2 $sockaddr = sockaddr_in $port, $ip_address
4633a7c4 188
c2654555 189=head2 ($port, $ip_address) = sockaddr_in $sockaddr
4bc6101e 190
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191A wrapper of pack_sockaddr_in() or unpack_sockaddr_in(). In list context,
192unpacks its argument and returns a list consisting of the port and IP address.
193In scalar context, packs its port and IP address arguments as a C<sockaddr_in>
194and returns it.
4bc6101e 195
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196Provided largely for legacy compatibility; it is better to use
197pack_sockaddr_in() or unpack_sockaddr_in() explicitly.
4bc6101e 198
c2654555 199=head2 $sockaddr = pack_sockaddr_in6 $port, $ip6_address, [$scope_id, [$flowinfo]]
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200
201Takes two to four arguments, a port number, an opaque string (as returned by
202inet_pton()), optionally a scope ID number, and optionally a flow label
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203number. Returns the C<sockaddr_in6> structure with those arguments packed in
204and C<AF_INET6> filled in. IPv6 equivalent of pack_sockaddr_in().
205
206=head2 ($port, $ip6_address, $scope_id, $flowinfo) = unpack_sockaddr_in6 $sockaddr
207
208Takes a C<sockaddr_in6> structure. Returns a list of four elements: the port
209number, an opaque string representing the IPv6 address, the scope ID, and the
210flow label. (You can use inet_ntop() to convert the address to the usual
211string format). Will croak if the structure does not represent an C<AF_INET6>
212address.
213
214=head2 $sockaddr = sockaddr_in6 $port, $ip6_address, [$scope_id, [$flowinfo]]
215
216=head2 ($port, $ip6_address, $scope_id, $flowinfo) = sockaddr_in6 $sockaddr
217
218A wrapper of pack_sockaddr_in6() or unpack_sockaddr_in6(). In list context,
219unpacks its argument according to unpack_sockaddr_in6(). In scalar context,
220packs its arguments according to pack_sockaddr_in6().
221
222Provided largely for legacy compatibility; it is better to use
223pack_sockaddr_in6() or unpack_sockaddr_in6() explicitly.
224
225=head2 $sockaddr = pack_sockaddr_un $path
226
227Takes one argument, a pathname. Returns the C<sockaddr_un> structure with that
228path packed in with C<AF_UNIX> filled in. For C<PF_UNIX> sockets, this
229structure is normally what you need for the arguments in bind(), connect(),
230and send().
231
232=head2 ($path) = unpack_sockaddr_un $sockaddr
233
234Takes a C<sockaddr_un> structure (as returned by pack_sockaddr_un(),
235getpeername() or recv()). Returns a list of one element: the pathname. Will
236croak if the structure does not represent an C<AF_UNIX> address.
c73aa44c 237
c2654555 238=head2 $sockaddr = sockaddr_un $path
c73aa44c 239
c2654555 240=head2 ($path) = sockaddr_un $sockaddr
c73aa44c 241
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242A wrapper of pack_sockaddr_un() or unpack_sockaddr_un(). In a list context,
243unpacks its argument and returns a list consisting of the pathname. In a
244scalar context, packs its pathname as a C<sockaddr_un> and returns it.
4633a7c4 245
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246Provided largely for legacy compatibility; it is better to use
247pack_sockaddr_un() or unpack_sockaddr_un() explicitly.
4633a7c4 248
1fef88e7 249These are only supported if your system has E<lt>F<sys/un.h>E<gt>.
4633a7c4 250
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251=head2 $ip_mreq = pack_ip_mreq $multiaddr, $interface
252
253Takes an IPv4 multicast address and optionally an interface address (or
254C<INADDR_ANY>). Returns the C<ip_mreq> structure with those arguments packed
255in. Suitable for use with the C<IP_ADD_MEMBERSHIP> and C<IP_DROP_MEMBERSHIP>
256sockopts.
257
258=head2 ($multiaddr, $interface) = unpack_ip_mreq $ip_mreq
c2654555 259
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260Takes an C<ip_mreq> structure. Returns a list of two elements; the IPv4
261multicast address and interface address.
c2654555 262
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263=head2 $ipv6_mreq = pack_ipv6_mreq $multiaddr6, $ifindex
264
265Takes an IPv6 multicast address and an interface number. Returns the
266C<ipv6_mreq> structure with those arguments packed in. Suitable for use with
267the C<IPV6_ADD_MEMBERSHIP> and C<IPV6_DROP_MEMBERSHIP> sockopts.
268
269=head2 ($multiaddr6, $ifindex) = unpack_ipv6_mreq $ipv6_mreq
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270
271Takes an C<ipv6_mreq> structure. Returns a list of two elements; the IPv6
272address and an interface number.
273
274=cut
275
276=head1 FUNCTIONS
277
278=cut
279
280=head2 $ip_address = inet_aton $string
281
282Takes a string giving the name of a host, or a textual representation of an IP
283address and translates that to an packed binary address structure suitable to
284pass to pack_sockaddr_in(). If passed a hostname that cannot be resolved,
285returns C<undef>. For multi-homed hosts (hosts with more than one address),
286the first address found is returned.
4633a7c4 287
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288For portability do not assume that the result of inet_aton() is 32 bits wide,
289in other words, that it would contain only the IPv4 address in network order.
4633a7c4 290
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291This IPv4-only function is provided largely for legacy reasons. Newly-written
292code should use getaddrinfo() or inet_pton() instead for IPv6 support.
4633a7c4 293
c2654555 294=head2 $string = inet_ntoa $ip_address
3b35bae3 295
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296Takes a packed binary address structure such as returned by
297unpack_sockaddr_in() (or a v-string representing the four octets of the IPv4
298address in network order) and translates it into a string of the form
299C<d.d.d.d> where the C<d>s are numbers less than 256 (the normal
300human-readable four dotted number notation for Internet addresses).
036d8bd4 301
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302This IPv4-only function is provided largely for legacy reasons. Newly-written
303code should use getnameinfo() or inet_ntop() instead for IPv6 support.
036d8bd4 304
c2654555 305=head2 $address = inet_pton $family, $string
d6896be3 306
c2654555 307Takes an address family (such as C<AF_INET> or C<AF_INET6>) and a string
23296748 308containing a textual representation of an address in that family and
c2654555 309translates that to an packed binary address structure.
036d8bd4 310
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311See also getaddrinfo() for a more powerful and flexible function to look up
312socket addresses given hostnames or textual addresses.
036d8bd4 313
c2654555 314=head2 $string = inet_ntop $family, $address
d6896be3 315
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316Takes an address family and a packed binary address structure and translates
317it into a human-readable textual representation of the address; typically in
318C<d.d.d.d> form for C<AF_INET> or C<hhhh:hhhh::hhhh> form for C<AF_INET6>.
e57a891d 319
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320See also getnameinfo() for a more powerful and flexible function to turn
321socket addresses into human-readable textual representations.
e57a891d 322
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323=head2 ($err, @result) = getaddrinfo $host, $service, [$hints]
324
325Given both a hostname and service name, this function attempts to resolve the
326host name into a list of network addresses, and the service name into a
327protocol and port number, and then returns a list of address structures
328suitable to connect() to it.
329
330Given just a host name, this function attempts to resolve it to a list of
331network addresses, and then returns a list of address structures giving these
332addresses.
333
334Given just a service name, this function attempts to resolve it to a protocol
335and port number, and then returns a list of address structures that represent
336it suitable to bind() to. This use should be combined with the C<AI_PASSIVE>
337flag; see below.
338
339Given neither name, it generates an error.
340
341If present, $hints should be a reference to a hash, where the following keys
342are recognised:
343
344=over 4
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345
346=item flags => INT
347
c2654555 348A bitfield containing C<AI_*> constants; see below.
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349
350=item family => INT
351
352Restrict to only generating addresses in this address family
353
354=item socktype => INT
355
356Restrict to only generating addresses of this socket type
357
358=item protocol => INT
359
360Restrict to only generating addresses for this protocol
361
362=back
363
364The return value will be a list; the first value being an error indication,
c2654555 365followed by a list of address structures (if no error occurred).
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366
367The error value will be a dualvar; comparable to the C<EI_*> error constants,
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368or printable as a human-readable error message string. If no error occurred it
369will be zero numerically and an empty string.
370
371Each value in the results list will be a hash reference containing the following
372fields:
e57a891d 373
c2654555 374=over 4
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375
376=item family => INT
377
c2654555 378The address family (e.g. C<AF_INET>)
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379
380=item socktype => INT
381
c2654555 382The socket type (e.g. C<SOCK_STREAM>)
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383
384=item protocol => INT
385
c2654555 386The protocol (e.g. C<IPPROTO_TCP>)
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387
388=item addr => STRING
389
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390The address in a packed string (such as would be returned by
391pack_sockaddr_in())
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392
393=item canonname => STRING
394
395The canonical name for the host if the C<AI_CANONNAME> flag was provided, or
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396C<undef> otherwise. This field will only be present on the first returned
397address.
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398
399=back
400
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401The following flag constants are recognised in the $hints hash. Other flag
402constants may exist as provided by the OS.
403
404=over 4
405
406=item AI_PASSIVE
e57a891d 407
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408Indicates that this resolution is for a local bind() for a passive (i.e.
409listening) socket, rather than an active (i.e. connecting) socket.
410
411=item AI_CANONNAME
412
413Indicates that the caller wishes the canonical hostname (C<canonname>) field
414of the result to be filled in.
415
416=item AI_NUMERICHOST
417
418Indicates that the caller will pass a numeric address, rather than a hostname,
419and that getaddrinfo() must not perform a resolve operation on this name. This
420flag will prevent a possibly-slow network lookup operation, and instead return
421an error if a hostname is passed.
422
423=back
424
425=head2 ($err, $hostname, $servicename) = getnameinfo $sockaddr, [$flags, [$xflags]]
426
427Given a packed socket address (such as from getsockname(), getpeername(), or
428returned by getaddrinfo() in a C<addr> field), returns the hostname and
429symbolic service name it represents. $flags may be a bitmask of C<NI_*>
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430constants, or defaults to 0 if unspecified.
431
432The return value will be a list; the first value being an error condition,
433followed by the hostname and service name.
434
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435The error value will be a dualvar; comparable to the C<EI_*> error constants,
436or printable as a human-readable error message string. The host and service
437names will be plain strings.
438
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439The following flag constants are recognised as $flags. Other flag constants may
440exist as provided by the OS.
441
442=over 4
443
444=item NI_NUMERICHOST
445
446Requests that a human-readable string representation of the numeric address be
447returned directly, rather than performing a name resolve operation that may
448convert it into a hostname. This will also avoid potentially-blocking network
449IO.
450
451=item NI_NUMERICSERV
452
453Requests that the port number be returned directly as a number representation
454rather than performing a name resolve operation that may convert it into a
455service name.
456
457=item NI_NAMEREQD
458
459If a name resolve operation fails to provide a name, then this flag will cause
460getnameinfo() to indicate an error, rather than returning the numeric
461representation as a human-readable string.
462
463=item NI_DGRAM
464
465Indicates that the socket address relates to a C<SOCK_DGRAM> socket, for the
466services whose name differs between TCP and UDP protocols.
467
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468=back
469
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470The following constants may be supplied as $xflags.
471
472=over 4
4f5bb87f 473
c2654555 474=item NIx_NOHOST
4f5bb87f 475
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476Indicates that the caller is not interested in the hostname of the result, so
477it does not have to be converted. C<undef> will be returned as the hostname.
4f5bb87f 478
c2654555 479=item NIx_NOSERV
4f5bb87f 480
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481Indicates that the caller is not interested in the service name of the result,
482so it does not have to be converted. C<undef> will be returned as the service
483name.
484
485=back
486
487=head1 getaddrinfo() / getnameinfo() ERROR CONSTANTS
488
489The following constants may be returned by getaddrinfo() or getnameinfo().
490Others may be provided by the OS.
491
492=over 4
493
494=item EAI_AGAIN
495
496A temporary failure occurred during name resolution. The operation may be
497successful if it is retried later.
498
499=item EAI_BADFLAGS
500
501The value of the C<flags> hint to getaddrinfo(), or the $flags parameter to
502getnameinfo() contains unrecognised flags.
503
504=item EAI_FAMILY
505
506The C<family> hint to getaddrinfo(), or the family of the socket address
507passed to getnameinfo() is not supported.
508
509=item EAI_NODATA
510
511The host name supplied to getaddrinfo() did not provide any usable address
512data.
513
514=item EAI_NONAME
515
516The host name supplied to getaddrinfo() does not exist, or the address
517supplied to getnameinfo() is not associated with a host name and the
518C<NI_NAMEREQD> flag was supplied.
519
520=item EAI_SERVICE
521
522The service name supplied to getaddrinfo() is not available for the socket
523type given in the $hints.
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524
525=back
526
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527=cut
528
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529=head1 EXAMPLES
530
531=head2 Lookup for connect()
532
533The getaddrinfo() function converts a hostname and a service name into a list
534of structures, each containing a potential way to connect() to the named
535service on the named host.
536
537 use IO::Socket;
538 use Socket qw(SOCK_STREAM getaddrinfo);
539
540 my %hints = (socktype => SOCK_STREAM);
541 my ($err, @res) = getaddrinfo("localhost", "echo", \%hints);
542 die "Cannot getaddrinfo - $err" if $err;
543
544 my $sock;
545
546 foreach my $ai (@res) {
547 my $candidate = IO::Socket->new();
548
549 $candidate->socket($ai->{family}, $ai->{socktype}, $ai->{protocol})
550 or next;
551
552 $candidate->connect($ai->{addr})
553 or next;
554
555 $sock = $candidate;
556 last;
557 }
558
559 die "Cannot connect to localhost:echo" unless $sock;
560
561 $sock->print("Hello, world!\n");
562 print <$sock>;
563
564Because a list of potential candidates is returned, the C<while> loop tries
565each in turn until it it finds one that succeeds both the socket() and
566connect() calls.
567
568This function performs the work of the legacy functions gethostbyname(),
569getservbyname(), inet_aton() and pack_sockaddr_in().
570
571In practice this logic is better performed by L<IO::Socket::IP>.
572
573=head2 Making a human-readable string out of an address
574
575The getnameinfo() function converts a socket address, such as returned by
576getsockname() or getpeername(), into a pair of human-readable strings
577representing the address and service name.
578
579 use IO::Socket::IP;
580 use Socket qw(getnameinfo);
581
582 my $server = IO::Socket::IP->new(LocalPort => 12345, Listen => 1) or
583 die "Cannot listen - $@";
584
585 my $socket = $server->accept or die "accept: $!";
586
587 my ($err, $hostname, $servicename) = getnameinfo($socket->peername);
588 die "Cannot getnameinfo - $err" if $err;
589
590 print "The peer is connected from $hostname\n";
591
592Since in this example only the hostname was used, the redundant conversion of
593the port number into a service name may be omitted by passing the
594C<NIx_NOSERV> flag.
595
596 use Socket qw(getnameinfo NIx_NOSERV);
597
598 my ($err, $hostname) = getnameinfo($socket->peername, 0, NIx_NOSERV);
599
600This function performs the work of the legacy functions unpack_sockaddr_in(),
601inet_ntoa(), gethostbyaddr() and getservbyport().
602
603In practice this logic is better performed by L<IO::Socket::IP>.
604
605=head2 Resolving hostnames into IP addresses
606
607To turn a hostname into a human-readable plain IP address use getaddrinfo()
608to turn the hostname into a list of socket structures, then getnameinfo() on
609each one to make it a readable IP address again.
610
611 use Socket qw(:addrinfo SOCK_RAW);
612
613 my ($err, @res) = getaddrinfo($hostname, "", {socktype => SOCK_RAW});
614 die "Cannot getaddrinfo - $err" if $err;
615
616 while( my $ai = shift @res ) {
617 my ($err, $ipaddr) = getnameinfo($ai->{addr}, NI_NUMERICHOST, NIx_NOSERV);
618 die "Cannot getnameinfo - $err" if $err;
619
620 print "$ipaddr\n";
621 }
622
623The C<socktype> hint to getaddrinfo() filters the results to only include one
624socket type and protocol. Without this most OSes return three combinations,
625for C<SOCK_STREAM>, C<SOCK_DGRAM> and C<SOCK_RAW>, resulting in triplicate
626output of addresses. The C<NI_NUMERICHOST> flag to getnameinfo() causes it to
627return a string-formatted plain IP address, rather than reverse resolving it
628back into a hostname.
629
630This combination performs the work of the legacy functions gethostbyname()
631and inet_ntoa().
632
633=head2 Accessing socket options
634
635The many C<SO_*> and other constants provide the socket option names for
636getsockopt() and setsockopt().
637
638 use IO::Socket::INET;
639 use Socket qw(SOL_SOCKET SO_RCVBUF IPPROTO_IP IP_TTL);
640
641 my $socket = IO::Socket::INET->new(LocalPort => 0, Proto => 'udp')
642 or die "Cannot create socket: $@";
643
644 $socket->setsockopt(SOL_SOCKET, SO_RCVBUF, 64*1024) or
645 die "setsockopt: $!";
646
647 print "Receive buffer is ", $socket->getsockopt(SOL_SOCKET, SO_RCVBUF),
648 " bytes\n";
649
650 print "IP TTL is ", $socket->getsockopt(IPPROTO_IP, IP_TTL), "\n";
651
652As a convenience, L<IO::Socket>'s setsockopt() method will convert a number
653into a packed byte buffer, and getsockopt() will unpack a byte buffer of the
654correct size back into a number.
655
656=cut
657
658=head1 AUTHOR
659
660This module was originally maintained in Perl core by the Perl 5 Porters.
661
662It was extracted to dual-life on CPAN at version 1.95 by
663Paul Evans <leonerd@leonerd.org.uk>
664
665=cut
666
a0d0e21e 667use Carp;
d3a7d8c7 668use warnings::register;
a0d0e21e
LW
669
670require Exporter;
da4061d3 671require XSLoader;
c2654555 672our @ISA = qw(Exporter);
80531fbd
LB
673
674# <@Nicholas> you can't change @EXPORT without breaking the implicit API
675# Please put any new constants in @EXPORT_OK!
c2654555
CBW
676
677# List re-ordered to match documentation above. Try to keep the ordering
678# consistent so it's easier to see which ones are or aren't documented.
679our @EXPORT = qw(
680 PF_802 PF_AAL PF_APPLETALK PF_CCITT PF_CHAOS PF_CTF PF_DATAKIT
681 PF_DECnet PF_DLI PF_ECMA PF_GOSIP PF_HYLINK PF_IMPLINK PF_INET PF_INET6
682 PF_ISO PF_KEY PF_LAST PF_LAT PF_LINK PF_MAX PF_NBS PF_NIT PF_NS PF_OSI
683 PF_OSINET PF_PUP PF_ROUTE PF_SNA PF_UNIX PF_UNSPEC PF_USER PF_WAN
a0d0e21e 684 PF_X25
c2654555
CBW
685
686 AF_802 AF_AAL AF_APPLETALK AF_CCITT AF_CHAOS AF_CTF AF_DATAKIT
687 AF_DECnet AF_DLI AF_ECMA AF_GOSIP AF_HYLINK AF_IMPLINK AF_INET AF_INET6
688 AF_ISO AF_KEY AF_LAST AF_LAT AF_LINK AF_MAX AF_NBS AF_NIT AF_NS AF_OSI
689 AF_OSINET AF_PUP AF_ROUTE AF_SNA AF_UNIX AF_UNSPEC AF_USER AF_WAN
690 AF_X25
691
692 SOCK_DGRAM SOCK_RAW SOCK_RDM SOCK_SEQPACKET SOCK_STREAM
693
a0d0e21e 694 SOL_SOCKET
c2654555
CBW
695
696 SO_ACCEPTCONN SO_ATTACH_FILTER SO_BACKLOG SO_BROADCAST SO_CHAMELEON
eabcd9c8
A
697 SO_DEBUG SO_DETACH_FILTER SO_DGRAM_ERRIND SO_DOMAIN SO_DONTLINGER
698 SO_DONTROUTE SO_ERROR SO_FAMILY SO_KEEPALIVE SO_LINGER SO_OOBINLINE
699 SO_PASSCRED SO_PASSIFNAME SO_PEERCRED SO_PROTOCOL SO_PROTOTYPE
700 SO_RCVBUF SO_RCVLOWAT SO_RCVTIMEO SO_REUSEADDR SO_REUSEPORT
c2654555
CBW
701 SO_SECURITY_AUTHENTICATION SO_SECURITY_ENCRYPTION_NETWORK
702 SO_SECURITY_ENCRYPTION_TRANSPORT SO_SNDBUF SO_SNDLOWAT SO_SNDTIMEO
703 SO_STATE SO_TYPE SO_USELOOPBACK SO_XOPEN SO_XSE
704
705 IP_OPTIONS IP_HDRINCL IP_TOS IP_TTL IP_RECVOPTS IP_RECVRETOPTS
706 IP_RETOPTS
707
708 MSG_BCAST MSG_BTAG MSG_CTLFLAGS MSG_CTLIGNORE MSG_CTRUNC MSG_DONTROUTE
709 MSG_DONTWAIT MSG_EOF MSG_EOR MSG_ERRQUEUE MSG_ETAG MSG_FIN
710 MSG_MAXIOVLEN MSG_MCAST MSG_NOSIGNAL MSG_OOB MSG_PEEK MSG_PROXY MSG_RST
711 MSG_SYN MSG_TRUNC MSG_URG MSG_WAITALL MSG_WIRE
712
713 SHUT_RD SHUT_RDWR SHUT_WR
714
715 INADDR_ANY INADDR_BROADCAST INADDR_LOOPBACK INADDR_NONE
716
717 SCM_CONNECT SCM_CREDENTIALS SCM_CREDS SCM_RIGHTS SCM_TIMESTAMP
718
a0d0e21e 719 SOMAXCONN
c2654555
CBW
720
721 IOV_MAX
6b1016b5 722 UIO_MAXIOV
c2654555
CBW
723
724 sockaddr_family
725 pack_sockaddr_in unpack_sockaddr_in sockaddr_in
726 pack_sockaddr_in6 unpack_sockaddr_in6 sockaddr_in6
727 pack_sockaddr_un unpack_sockaddr_un sockaddr_un
728
729 inet_aton inet_ntoa
730);
731
732# List re-ordered to match documentation above. Try to keep the ordering
733# consistent so it's easier to see which ones are or aren't documented.
734our @EXPORT_OK = qw(
735 CR LF CRLF $CR $LF $CRLF
736
3be135d8
TC
737 SOCK_NONBLOCK SOCK_CLOEXEC
738
739 IP_ADD_MEMBERSHIP IP_DROP_MEMBERSHIP IP_MULTICAST_IF
740 IP_MULTICAST_LOOP IP_MULTICAST_TTL
741
c2654555
CBW
742 IPPROTO_IP IPPROTO_IPV6 IPPROTO_RAW IPPROTO_ICMP IPPROTO_TCP
743 IPPROTO_UDP
744
745 TCP_CONGESTION TCP_CORK TCP_DEFER_ACCEPT TCP_INFO TCP_KEEPALIVE
746 TCP_KEEPCNT TCP_KEEPIDLE TCP_KEEPINTVL TCP_LINGER2 TCP_MAXRT TCP_MAXSEG
747 TCP_MD5SIG TCP_NODELAY TCP_QUICKACK TCP_STDURG TCP_SYNCNT
748 TCP_WINDOW_CLAMP
749
750 IN6ADDR_ANY IN6ADDR_LOOPBACK
751
752 IPV6_ADD_MEMBERSHIP IPV6_DROP_MEMBERSHIP IPV6_MTU IPV6_MTU_DISCOVER
753 IPV6_MULTICAST_HOPS IPV6_MULTICAST_IF IPV6_MULTICAST_LOOP
754 IPV6_UNICAST_HOPS IPV6_V6ONLY
755
3be135d8
TC
756 pack_ip_mreq unpack_ip_mreq
757
c2654555
CBW
758 pack_ipv6_mreq unpack_ipv6_mreq
759
760 inet_pton inet_ntop
761
762 getaddrinfo getnameinfo
763
764 AI_ADDRCONFIG AI_ALL AI_CANONIDN AI_CANONNAME AI_IDN
765 AI_IDN_ALLOW_UNASSIGNED AI_IDN_USE_STD3_ASCII_RULES AI_NUMERICHOST
766 AI_NUMERICSERV AI_PASSIVE AI_V4MAPPED
767
768 NI_DGRAM NI_IDN NI_IDN_ALLOW_UNASSIGNED NI_IDN_USE_STD3_ASCII_RULES
769 NI_NAMEREQD NI_NOFQDN NI_NUMERICHOST NI_NUMERICSERV
770
771 NIx_NOHOST NIx_NOSERV
772
773 EAI_ADDRFAMILY EAI_AGAIN EAI_BADFLAGS EAI_BADHINTS EAI_FAIL EAI_FAMILY
774 EAI_NODATA EAI_NONAME EAI_PROTOCOL EAI_SERVICE EAI_SOCKTYPE EAI_SYSTEM
a0d0e21e
LW
775);
776
c2654555
CBW
777our %EXPORT_TAGS = (
778 crlf => [qw(CR LF CRLF $CR $LF $CRLF)],
779 addrinfo => [qw(getaddrinfo getnameinfo), grep m/^(?:AI|NI|NIx|EAI)_/, @EXPORT_OK],
780 all => [@EXPORT, @EXPORT_OK],
fdb41d65
CN
781);
782
783BEGIN {
784 sub CR () {"\015"}
785 sub LF () {"\012"}
786 sub CRLF () {"\015\012"}
c2654555
CBW
787
788 # These are not gni() constants; they're extensions for the perl API
789 # The definitions in Socket.pm and Socket.xs must match
790 sub NIx_NOHOST() {1 << 0}
791 sub NIx_NOSERV() {1 << 1}
fdb41d65
CN
792}
793
794*CR = \CR();
795*LF = \LF();
796*CRLF = \CRLF();
797
4633a7c4
LW
798sub sockaddr_in {
799 if (@_ == 6 && !wantarray) { # perl5.001m compat; use this && die
800 my($af, $port, @quad) = @_;
c2654555 801 warnings::warn "6-ARG sockaddr_in call is deprecated"
d3a7d8c7 802 if warnings::enabled();
4633a7c4
LW
803 pack_sockaddr_in($port, inet_aton(join('.', @quad)));
804 } elsif (wantarray) {
805 croak "usage: (port,iaddr) = sockaddr_in(sin_sv)" unless @_ == 1;
806 unpack_sockaddr_in(@_);
807 } else {
808 croak "usage: sin_sv = sockaddr_in(port,iaddr))" unless @_ == 2;
809 pack_sockaddr_in(@_);
810 }
811}
812
4bc6101e
PLE
813sub sockaddr_in6 {
814 if (wantarray) {
815 croak "usage: (port,in6addr,scope_id,flowinfo) = sockaddr_in6(sin6_sv)" unless @_ == 1;
816 unpack_sockaddr_in6(@_);
817 }
818 else {
819 croak "usage: sin6_sv = sockaddr_in6(port,in6addr,[scope_id,[flowinfo]])" unless @_ >= 2 and @_ <= 4;
820 pack_sockaddr_in6(@_);
821 }
822}
823
4633a7c4
LW
824sub sockaddr_un {
825 if (wantarray) {
826 croak "usage: (filename) = sockaddr_un(sun_sv)" unless @_ == 1;
827 unpack_sockaddr_un(@_);
828 } else {
37120919
AD
829 croak "usage: sun_sv = sockaddr_un(filename)" unless @_ == 1;
830 pack_sockaddr_un(@_);
4633a7c4
LW
831 }
832}
833
4c3d8e12 834XSLoader::load(__PACKAGE__, $VERSION);
a0d0e21e 835
c2219427
PLE
836my %errstr;
837
32b40adf
NC
838if( defined &getaddrinfo ) {
839 # These are not part of the API, nothing uses them, and deleting them
840 # reduces the size of %Socket:: by about 12K
841 delete $Socket::{fake_getaddrinfo};
842 delete $Socket::{fake_getnameinfo};
843} else {
0f41f5e2
PLE
844 require Scalar::Util;
845
846 *getaddrinfo = \&fake_getaddrinfo;
847 *getnameinfo = \&fake_getnameinfo;
848
849 # These numbers borrowed from GNU libc's implementation, but since
850 # they're only used by our emulation, it doesn't matter if the real
851 # platform's values differ
852 my %constants = (
853 AI_PASSIVE => 1,
854 AI_CANONNAME => 2,
855 AI_NUMERICHOST => 4,
0369a5a5
PLE
856 AI_V4MAPPED => 8,
857 AI_ALL => 16,
858 AI_ADDRCONFIG => 32,
0f41f5e2
PLE
859 # RFC 2553 doesn't define this but Linux does - lets be nice and
860 # provide it since we can
861 AI_NUMERICSERV => 1024,
862
863 EAI_BADFLAGS => -1,
864 EAI_NONAME => -2,
865 EAI_NODATA => -5,
866 EAI_FAMILY => -6,
867 EAI_SERVICE => -8,
868
869 NI_NUMERICHOST => 1,
870 NI_NUMERICSERV => 2,
0369a5a5 871 NI_NOFQDN => 4,
0f41f5e2
PLE
872 NI_NAMEREQD => 8,
873 NI_DGRAM => 16,
0369a5a5
PLE
874
875 # Constants we don't support. Export them, but croak if anyone tries to
876 # use them
877 AI_IDN => 64,
878 AI_CANONIDN => 128,
879 AI_IDN_ALLOW_UNASSIGNED => 256,
880 AI_IDN_USE_STD3_ASCII_RULES => 512,
881 NI_IDN => 32,
882 NI_IDN_ALLOW_UNASSIGNED => 64,
883 NI_IDN_USE_STD3_ASCII_RULES => 128,
884
885 # Error constants we'll never return, so it doesn't matter what value
886 # these have, nor that we don't provide strings for them
887 EAI_SYSTEM => -11,
888 EAI_BADHINTS => -1000,
889 EAI_PROTOCOL => -1001
0f41f5e2
PLE
890 );
891
892 foreach my $name ( keys %constants ) {
893 my $value = $constants{$name};
894
895 no strict 'refs';
896 defined &$name or *$name = sub () { $value };
897 }
898
899 %errstr = (
900 # These strings from RFC 2553
901 EAI_BADFLAGS() => "invalid value for ai_flags",
902 EAI_NONAME() => "nodename nor servname provided, or not known",
903 EAI_NODATA() => "no address associated with nodename",
904 EAI_FAMILY() => "ai_family not supported",
905 EAI_SERVICE() => "servname not supported for ai_socktype",
906 );
c2219427
PLE
907}
908
909# The following functions are used if the system does not have a
910# getaddrinfo(3) function in libc; and are used to emulate it for the AF_INET
911# family
912
c2219427
PLE
913# Borrowed from Regexp::Common::net
914my $REGEXP_IPv4_DECIMAL = qr/25[0-5]|2[0-4][0-9]|1?[0-9][0-9]{1,2}/;
915my $REGEXP_IPv4_DOTTEDQUAD = qr/$REGEXP_IPv4_DECIMAL\.$REGEXP_IPv4_DECIMAL\.$REGEXP_IPv4_DECIMAL\.$REGEXP_IPv4_DECIMAL/;
916
917sub fake_makeerr
918{
0f41f5e2
PLE
919 my ( $errno ) = @_;
920 my $errstr = $errno == 0 ? "" : ( $errstr{$errno} || $errno );
921 return Scalar::Util::dualvar( $errno, $errstr );
c2219427
PLE
922}
923
924sub fake_getaddrinfo
925{
0f41f5e2
PLE
926 my ( $node, $service, $hints ) = @_;
927
928 $node = "" unless defined $node;
929
930 $service = "" unless defined $service;
931
932 my ( $family, $socktype, $protocol, $flags ) = @$hints{qw( family socktype protocol flags )};
933
934 $family ||= Socket::AF_INET(); # 0 == AF_UNSPEC, which we want too
935 $family == Socket::AF_INET() or return fake_makeerr( EAI_FAMILY() );
936
937 $socktype ||= 0;
938
939 $protocol ||= 0;
940
941 $flags ||= 0;
942
943 my $flag_passive = $flags & AI_PASSIVE(); $flags &= ~AI_PASSIVE();
944 my $flag_canonname = $flags & AI_CANONNAME(); $flags &= ~AI_CANONNAME();
945 my $flag_numerichost = $flags & AI_NUMERICHOST(); $flags &= ~AI_NUMERICHOST();
946 my $flag_numericserv = $flags & AI_NUMERICSERV(); $flags &= ~AI_NUMERICSERV();
947
0369a5a5
PLE
948 # These constants don't apply to AF_INET-only lookups, so we might as well
949 # just ignore them. For AI_ADDRCONFIG we just presume the host has ability
950 # to talk AF_INET. If not we'd have to return no addresses at all. :)
951 $flags &= ~(AI_V4MAPPED()|AI_ALL()|AI_ADDRCONFIG());
952
953 $flags & (AI_IDN()|AI_CANONIDN()|AI_IDN_ALLOW_UNASSIGNED()|AI_IDN_USE_STD3_ASCII_RULES()) and
954 croak "Socket::getaddrinfo() does not support IDN";
955
0f41f5e2
PLE
956 $flags == 0 or return fake_makeerr( EAI_BADFLAGS() );
957
958 $node eq "" and $service eq "" and return fake_makeerr( EAI_NONAME() );
959
960 my $canonname;
961 my @addrs;
962 if( $node ne "" ) {
963 return fake_makeerr( EAI_NONAME() ) if( $flag_numerichost and $node !~ m/^$REGEXP_IPv4_DOTTEDQUAD$/ );
964 ( $canonname, undef, undef, undef, @addrs ) = gethostbyname( $node );
965 defined $canonname or return fake_makeerr( EAI_NONAME() );
966
967 undef $canonname unless $flag_canonname;
968 }
969 else {
970 $addrs[0] = $flag_passive ? Socket::inet_aton( "0.0.0.0" )
971 : Socket::inet_aton( "127.0.0.1" );
972 }
973
974 my @ports; # Actually ARRAYrefs of [ socktype, protocol, port ]
975 my $protname = "";
976 if( $protocol ) {
977 $protname = getprotobynumber( $protocol );
978 }
979
980 if( $service ne "" and $service !~ m/^\d+$/ ) {
981 return fake_makeerr( EAI_NONAME() ) if( $flag_numericserv );
982 getservbyname( $service, $protname ) or return fake_makeerr( EAI_SERVICE() );
983 }
984
985 foreach my $this_socktype ( Socket::SOCK_STREAM(), Socket::SOCK_DGRAM(), Socket::SOCK_RAW() ) {
986 next if $socktype and $this_socktype != $socktype;
987
988 my $this_protname = "raw";
989 $this_socktype == Socket::SOCK_STREAM() and $this_protname = "tcp";
990 $this_socktype == Socket::SOCK_DGRAM() and $this_protname = "udp";
991
992 next if $protname and $this_protname ne $protname;
993
994 my $port;
995 if( $service ne "" ) {
996 if( $service =~ m/^\d+$/ ) {
997 $port = "$service";
998 }
999 else {
1000 ( undef, undef, $port, $this_protname ) = getservbyname( $service, $this_protname );
1001 next unless defined $port;
1002 }
1003 }
1004 else {
1005 $port = 0;
1006 }
1007
1008 push @ports, [ $this_socktype, scalar getprotobyname( $this_protname ) || 0, $port ];
1009 }
1010
1011 my @ret;
1012 foreach my $addr ( @addrs ) {
1013 foreach my $portspec ( @ports ) {
1014 my ( $socktype, $protocol, $port ) = @$portspec;
1015 push @ret, {
1016 family => $family,
1017 socktype => $socktype,
1018 protocol => $protocol,
1019 addr => Socket::pack_sockaddr_in( $port, $addr ),
0cd14f2e 1020 canonname => undef,
0f41f5e2
PLE
1021 };
1022 }
1023 }
1024
0cd14f2e
PLE
1025 # Only supply canonname for the first result
1026 if( defined $canonname ) {
1027 $ret[0]->{canonname} = $canonname;
1028 }
1029
0f41f5e2 1030 return ( fake_makeerr( 0 ), @ret );
c2219427
PLE
1031}
1032
1033sub fake_getnameinfo
1034{
c2654555 1035 my ( $addr, $flags, $xflags ) = @_;
0f41f5e2
PLE
1036
1037 my ( $port, $inetaddr );
1038 eval { ( $port, $inetaddr ) = Socket::unpack_sockaddr_in( $addr ) }
1039 or return fake_makeerr( EAI_FAMILY() );
1040
1041 my $family = Socket::AF_INET();
1042
1043 $flags ||= 0;
1044
1045 my $flag_numerichost = $flags & NI_NUMERICHOST(); $flags &= ~NI_NUMERICHOST();
1046 my $flag_numericserv = $flags & NI_NUMERICSERV(); $flags &= ~NI_NUMERICSERV();
0369a5a5 1047 my $flag_nofqdn = $flags & NI_NOFQDN(); $flags &= ~NI_NOFQDN();
0f41f5e2
PLE
1048 my $flag_namereqd = $flags & NI_NAMEREQD(); $flags &= ~NI_NAMEREQD();
1049 my $flag_dgram = $flags & NI_DGRAM() ; $flags &= ~NI_DGRAM();
1050
0369a5a5
PLE
1051 $flags & (NI_IDN()|NI_IDN_ALLOW_UNASSIGNED()|NI_IDN_USE_STD3_ASCII_RULES()) and
1052 croak "Socket::getnameinfo() does not support IDN";
1053
0f41f5e2
PLE
1054 $flags == 0 or return fake_makeerr( EAI_BADFLAGS() );
1055
c2654555
CBW
1056 $xflags ||= 0;
1057
0f41f5e2 1058 my $node;
c2654555
CBW
1059 if( $xflags & NIx_NOHOST ) {
1060 $node = undef;
1061 }
1062 elsif( $flag_numerichost ) {
0f41f5e2
PLE
1063 $node = Socket::inet_ntoa( $inetaddr );
1064 }
1065 else {
1066 $node = gethostbyaddr( $inetaddr, $family );
1067 if( !defined $node ) {
1068 return fake_makeerr( EAI_NONAME() ) if $flag_namereqd;
1069 $node = Socket::inet_ntoa( $inetaddr );
1070 }
0369a5a5
PLE
1071 elsif( $flag_nofqdn ) {
1072 my ( $shortname ) = split m/\./, $node;
1073 my ( $fqdn ) = gethostbyname $shortname;
1074 $node = $shortname if defined $fqdn and $fqdn eq $node;
1075 }
0f41f5e2
PLE
1076 }
1077
1078 my $service;
c2654555
CBW
1079 if( $xflags & NIx_NOSERV ) {
1080 $service = undef;
1081 }
1082 elsif( $flag_numericserv ) {
0f41f5e2
PLE
1083 $service = "$port";
1084 }
1085 else {
1086 my $protname = $flag_dgram ? "udp" : "";
1087 $service = getservbyport( $port, $protname );
1088 if( !defined $service ) {
1089 $service = "$port";
1090 }
1091 }
1092
1093 return ( fake_makeerr( 0 ), $node, $service );
c2219427
PLE
1094}
1095
a0d0e21e 10961;