PC World 2003 March/PCWorld_2003-03_cd.bin/Software/Topware/activeperl/ActivePerl/Perl/lib/Socket.pm

Perl POD Document | 2002-06-19 | 10.0 KB | 402 lines

package Socket;

our($VERSION, @ISA, @EXPORT, @EXPORT_OK, %EXPORT_TAGS);
$VERSION = "1.75";

=head1 NAME

Socket, sockaddr_in, sockaddr_un, inet_aton, inet_ntoa - load the C socket.h defines and structure manipulators

=head1 SYNOPSIS

    use Socket;

    $proto = getprotobyname('udp');
    socket(Socket_Handle, PF_INET, SOCK_DGRAM, $proto);
    $iaddr = gethostbyname('hishost.com');
    $port = getservbyname('time', 'udp');
    $sin = sockaddr_in($port, $iaddr);
    send(Socket_Handle, 0, 0, $sin);

    $proto = getprotobyname('tcp');
    socket(Socket_Handle, PF_INET, SOCK_STREAM, $proto);
    $port = getservbyname('smtp', 'tcp');
    $sin = sockaddr_in($port,inet_aton("127.1"));
    $sin = sockaddr_in(7,inet_aton("localhost"));
    $sin = sockaddr_in(7,INADDR_LOOPBACK);
    connect(Socket_Handle,$sin);

    ($port, $iaddr) = sockaddr_in(getpeername(Socket_Handle));
    $peer_host = gethostbyaddr($iaddr, AF_INET);
    $peer_addr = inet_ntoa($iaddr);

    $proto = getprotobyname('tcp');
    socket(Socket_Handle, PF_UNIX, SOCK_STREAM, $proto);
    unlink('/tmp/usock');
    $sun = sockaddr_un('/tmp/usock');
    connect(Socket_Handle,$sun);

=head1 DESCRIPTION

This module is just a translation of the C F<socket.h> file.
Unlike the old mechanism of requiring a translated F<socket.ph>
file, this uses the B<h2xs> program (see the Perl source distribution)
and your native C compiler.  This means that it has a
far more likely chance of getting the numbers right.  This includes
all of the commonly used pound-defines like AF_INET, SOCK_STREAM, etc.

Also, some common socket "newline" constants are provided: the
constants C<CR>, C<LF>, and C<CRLF>, as well as C<$CR>, C<$LF>, and
C<$CRLF>, which map to C<\015>, C<\012>, and C<\015\012>.  If you do
not want to use the literal characters in your programs, then use
the constants provided here.  They are not exported by default, but can
be imported individually, and with the C<:crlf> export tag:

    use Socket qw(:DEFAULT :crlf);

In addition, some structure manipulation functions are available:

=over 4

=item inet_aton HOSTNAME

Takes a string giving the name of a host, and translates that to an
opaque string (if programming in C, struct in_addr). Takes arguments
of both the 'rtfm.mit.edu' type and '18.181.0.24'. If the host name
cannot be resolved, returns undef.  For multi-homed hosts (hosts with
more than one address), the first address found is returned.

For portability do not assume that the result of inet_aton() is 32
bits wide, in other words, that it would contain only the IPv4 address
in network order.

=item inet_ntoa IP_ADDRESS

Takes a string (an opaque string as returned by inet_aton(),
or a v-string representing the four octets of the IPv4 address in
network order) and translates it into a string of the form 'd.d.d.d'
where the 'd's are numbers less than 256 (the normal human-readable
four dotted number notation for Internet addresses).

=item INADDR_ANY

Note: does not return a number, but a packed string.

Returns the 4-byte wildcard ip address which specifies any
of the hosts ip addresses.  (A particular machine can have
more than one ip address, each address corresponding to
a particular network interface. This wildcard address
allows you to bind to all of them simultaneously.)
Normally equivalent to inet_aton('0.0.0.0').

=item INADDR_BROADCAST

Note: does not return a number, but a packed string.

Returns the 4-byte 'this-lan' ip broadcast address.
This can be useful for some protocols to solicit information
from all servers on the same LAN cable.
Normally equivalent to inet_aton('255.255.255.255').

=item INADDR_LOOPBACK

Note - does not return a number.

Returns the 4-byte loopback address.  Normally equivalent
to inet_aton('localhost').

=item INADDR_NONE

Note - does not return a number.

Returns the 4-byte 'invalid' ip address.  Normally equivalent
to inet_aton('255.255.255.255').

=item sockaddr_family SOCKADDR

Takes a sockaddr structure (as returned by pack_sockaddr_in(),
pack_sockaddr_un() or the perl builtin functions getsockname() and
getpeername()) and returns the address family tag.  It will match the
constant AF_INET for a sockaddr_in and AF_UNIX for a sockaddr_un.  It
can be used to figure out what unpacker to use for a sockaddr of
unknown type.

=item sockaddr_in PORT, ADDRESS

=item sockaddr_in SOCKADDR_IN

In a list context, unpacks its SOCKADDR_IN argument and returns an array
consisting of (PORT, ADDRESS).  In a scalar context, packs its (PORT,
ADDRESS) arguments as a SOCKADDR_IN and returns it.  If this is confusing,
use pack_sockaddr_in() and unpack_sockaddr_in() explicitly.

=item pack_sockaddr_in PORT, IP_ADDRESS

Takes two arguments, a port number and an opaque string, IP_ADDRESS
(as returned by inet_aton(), or a v-string).  Returns the sockaddr_in
structure with those arguments packed in with AF_INET filled in.  For
Internet domain sockets, this structure is normally what you need for
the arguments in bind(), connect(), and send(), and is also returned
by getpeername(), getsockname() and recv().

=item unpack_sockaddr_in SOCKADDR_IN

Takes a sockaddr_in structure (as returned by pack_sockaddr_in()) and
returns an array of two elements: the port and an opaque string
representing the IP address (you can use inet_ntoa() to convert the
address to the four-dotted numeric format).  Will croak if the
structure does not have AF_INET in the right place.

=item sockaddr_un PATHNAME

=item sockaddr_un SOCKADDR_UN

In a list context, unpacks its SOCKADDR_UN argument and returns an array
consisting of (PATHNAME).  In a scalar context, packs its PATHNAME
arguments as a SOCKADDR_UN and returns it.  If this is confusing, use
pack_sockaddr_un() and unpack_sockaddr_un() explicitly.
These are only supported if your system has E<lt>F<sys/un.h>E<gt>.

=item pack_sockaddr_un PATH

Takes one argument, a pathname. Returns the sockaddr_un structure with
that path packed in with AF_UNIX filled in. For unix domain sockets, this
structure is normally what you need for the arguments in bind(),
connect(), and send(), and is also returned by getpeername(),
getsockname() and recv().

=item unpack_sockaddr_un SOCKADDR_UN

Takes a sockaddr_un structure (as returned by pack_sockaddr_un())
and returns the pathname.  Will croak if the structure does not
have AF_UNIX in the right place.

=back

=cut

use Carp;
use warnings::register;

require Exporter;
use XSLoader ();
@ISA = qw(Exporter);
@EXPORT = qw(
    inet_aton inet_ntoa
    sockaddr_family
    pack_sockaddr_in unpack_sockaddr_in
    pack_sockaddr_un unpack_sockaddr_un
    sockaddr_in sockaddr_un
    INADDR_ANY INADDR_BROADCAST INADDR_LOOPBACK INADDR_NONE
    AF_802
    AF_AAL
    AF_APPLETALK
    AF_CCITT
    AF_CHAOS
    AF_CTF
    AF_DATAKIT
    AF_DECnet
    AF_DLI
    AF_ECMA
    AF_GOSIP
    AF_HYLINK
    AF_IMPLINK
    AF_INET
    AF_INET6
    AF_ISO
    AF_KEY
    AF_LAST
    AF_LAT
    AF_LINK
    AF_MAX
    AF_NBS
    AF_NIT
    AF_NS
    AF_OSI
    AF_OSINET
    AF_PUP
    AF_ROUTE
    AF_SNA
    AF_UNIX
    AF_UNSPEC
    AF_USER
    AF_WAN
    AF_X25
    IOV_MAX
    MSG_BCAST
    MSG_BTAG
    MSG_CTLFLAGS
    MSG_CTLIGNORE
    MSG_CTRUNC
    MSG_DONTROUTE
    MSG_DONTWAIT
    MSG_EOF
    MSG_EOR
    MSG_ERRQUEUE
    MSG_ETAG
    MSG_FIN
    MSG_MAXIOVLEN
    MSG_MCAST
    MSG_NOSIGNAL
    MSG_OOB
    MSG_PEEK
    MSG_PROXY
    MSG_RST
    MSG_SYN
    MSG_TRUNC
    MSG_URG
    MSG_WAITALL
    MSG_WIRE
    PF_802
    PF_AAL
    PF_APPLETALK
    PF_CCITT
    PF_CHAOS
    PF_CTF
    PF_DATAKIT
    PF_DECnet
    PF_DLI
    PF_ECMA
    PF_GOSIP
    PF_HYLINK
    PF_IMPLINK
    PF_INET
    PF_INET6
    PF_ISO
    PF_KEY
    PF_LAST
    PF_LAT
    PF_LINK
    PF_MAX
    PF_NBS
    PF_NIT
    PF_NS
    PF_OSI
    PF_OSINET
    PF_PUP
    PF_ROUTE
    PF_SNA
    PF_UNIX
    PF_UNSPEC
    PF_USER
    PF_WAN
    PF_X25
    SCM_CONNECT
    SCM_CREDENTIALS
    SCM_CREDS
    SCM_RIGHTS
    SCM_TIMESTAMP
    SHUT_RD
    SHUT_RDWR
    SHUT_WR
    SOCK_DGRAM
    SOCK_RAW
    SOCK_RDM
    SOCK_SEQPACKET
    SOCK_STREAM
    SOL_SOCKET
    SOMAXCONN
    SO_ACCEPTCONN
    SO_ATTACH_FILTER
    SO_BACKLOG
    SO_BROADCAST
    SO_CHAMELEON
    SO_DEBUG
    SO_DETACH_FILTER
    SO_DGRAM_ERRIND
    SO_DONTLINGER
    SO_DONTROUTE
    SO_ERROR
    SO_FAMILY
    SO_KEEPALIVE
    SO_LINGER
    SO_OOBINLINE
    SO_PASSCRED
    SO_PASSIFNAME
    SO_PEERCRED
    SO_PROTOCOL
    SO_PROTOTYPE
    SO_RCVBUF
    SO_RCVLOWAT
    SO_RCVTIMEO
    SO_REUSEADDR
    SO_REUSEPORT
    SO_SECURITY_AUTHENTICATION
    SO_SECURITY_ENCRYPTION_NETWORK
    SO_SECURITY_ENCRYPTION_TRANSPORT
    SO_SNDBUF
    SO_SNDLOWAT
    SO_SNDTIMEO
    SO_STATE
    SO_TYPE
    SO_USELOOPBACK
    SO_XOPEN
    SO_XSE
    UIO_MAXIOV
);

@EXPORT_OK = qw(CR LF CRLF $CR $LF $CRLF

           IPPROTO_TCP
           TCP_KEEPALIVE
           TCP_MAXRT
           TCP_MAXSEG
           TCP_NODELAY
           TCP_STDURG);

%EXPORT_TAGS = (
    crlf    => [qw(CR LF CRLF $CR $LF $CRLF)],
    all     => [@EXPORT, @EXPORT_OK],
);

BEGIN {
    sub CR   () {"\015"}
    sub LF   () {"\012"}
    sub CRLF () {"\015\012"}
}

*CR   = \CR();
*LF   = \LF();
*CRLF = \CRLF();

sub sockaddr_in {
    if (@_ == 6 && !wantarray) { # perl5.001m compat; use this && die
    my($af, $port, @quad) = @_;
    warnings::warn "6-ARG sockaddr_in call is deprecated"
        if warnings::enabled();
    pack_sockaddr_in($port, inet_aton(join('.', @quad)));
    } elsif (wantarray) {
    croak "usage:   (port,iaddr) = sockaddr_in(sin_sv)" unless @_ == 1;
        unpack_sockaddr_in(@_);
    } else {
    croak "usage:   sin_sv = sockaddr_in(port,iaddr))" unless @_ == 2;
        pack_sockaddr_in(@_);
    }
}

sub sockaddr_un {
    if (wantarray) {
    croak "usage:   (filename) = sockaddr_un(sun_sv)" unless @_ == 1;
        unpack_sockaddr_un(@_);
    } else {
    croak "usage:   sun_sv = sockaddr_un(filename)" unless @_ == 1;
        pack_sockaddr_un(@_);
    }
}

sub AUTOLOAD {
    my($constname);
    ($constname = $AUTOLOAD) =~ s/.*:://;
    croak "&Socket::constant not defined" if $constname eq 'constant';
    my ($error, $val) = constant($constname);
    if ($error) {
    croak $error;
    }
    *$AUTOLOAD = sub { $val };
    goto &$AUTOLOAD;
}

XSLoader::load 'Socket', $VERSION;

1;