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Diffstat (limited to 'contrib/perl5/lib/Net/netent.pm')
| -rw-r--r-- | contrib/perl5/lib/Net/netent.pm | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/contrib/perl5/lib/Net/netent.pm b/contrib/perl5/lib/Net/netent.pm new file mode 100644 index 0000000000000..b82447cad71ab --- /dev/null +++ b/contrib/perl5/lib/Net/netent.pm @@ -0,0 +1,167 @@ +package Net::netent; +use strict; + +BEGIN { + use Exporter (); + use vars qw(@EXPORT @EXPORT_OK %EXPORT_TAGS); + @EXPORT = qw(getnetbyname getnetbyaddr getnet); + @EXPORT_OK = qw( + $n_name @n_aliases + $n_addrtype $n_net + ); + %EXPORT_TAGS = ( FIELDS => [ @EXPORT_OK, @EXPORT ] ); +} +use vars @EXPORT_OK; + +# Class::Struct forbids use of @ISA +sub import { goto &Exporter::import } + +use Class::Struct qw(struct); +struct 'Net::netent' => [ + name => '$', + aliases => '@', + addrtype => '$', + net => '$', +]; + +sub populate (@) { + return unless @_; + my $nob = new(); + $n_name = $nob->[0] = $_[0]; + @n_aliases = @{ $nob->[1] } = split ' ', $_[1]; + $n_addrtype = $nob->[2] = $_[2]; + $n_net = $nob->[3] = $_[3]; + return $nob; +} + +sub getnetbyname ($) { populate(CORE::getnetbyname(shift)) } + +sub getnetbyaddr ($;$) { + my ($net, $addrtype); + $net = shift; + require Socket if @_; + $addrtype = @_ ? shift : Socket::AF_INET(); + populate(CORE::getnetbyaddr($net, $addrtype)) +} + +sub getnet($) { + if ($_[0] =~ /^\d+(?:\.\d+(?:\.\d+(?:\.\d+)?)?)?$/) { + require Socket; + &getnetbyaddr(Socket::inet_aton(shift)); + } else { + &getnetbyname; + } +} + +1; +__END__ + +=head1 NAME + +Net::netent - by-name interface to Perl's built-in getnet*() functions + +=head1 SYNOPSIS + + use Net::netent qw(:FIELDS); + getnetbyname("loopback") or die "bad net"; + printf "%s is %08X\n", $n_name, $n_net; + + use Net::netent; + + $n = getnetbyname("loopback") or die "bad net"; + { # there's gotta be a better way, eh? + @bytes = unpack("C4", pack("N", $n->net)); + shift @bytes while @bytes && $bytes[0] == 0; + } + printf "%s is %08X [%d.%d.%d.%d]\n", $n->name, $n->net, @bytes; + +=head1 DESCRIPTION + +This module's default exports override the core getnetbyname() and +getnetbyaddr() functions, replacing them with versions that return +"Net::netent" objects. This object has methods that return the similarly +named structure field name from the C's netent structure from F<netdb.h>; +namely name, aliases, addrtype, and net. The aliases +method returns an array reference, the rest scalars. + +You may also import all the structure fields directly into your namespace +as regular variables using the :FIELDS import tag. (Note that this still +overrides your core functions.) Access these fields as variables named +with a preceding C<n_>. Thus, C<$net_obj-E<gt>name()> corresponds to +$n_name if you import the fields. Array references are available as +regular array variables, so for example C<@{ $net_obj-E<gt>aliases() +}> would be simply @n_aliases. + +The getnet() funtion is a simple front-end that forwards a numeric +argument to getnetbyaddr(), and the rest +to getnetbyname(). + +To access this functionality without the core overrides, +pass the C<use> an empty import list, and then access +function functions with their full qualified names. +On the other hand, the built-ins are still available +via the C<CORE::> pseudo-package. + +=head1 EXAMPLES + +The getnet() functions do this in the Perl core: + + sv_setiv(sv, (I32)nent->n_net); + +The gethost() functions do this in the Perl core: + + sv_setpvn(sv, hent->h_addr, len); + +That means that the address comes back in binary for the +host functions, and as a regular perl integer for the net ones. +This seems a bug, but here's how to deal with it: + + use strict; + use Socket; + use Net::netent; + + @ARGV = ('loopback') unless @ARGV; + + my($n, $net); + + for $net ( @ARGV ) { + + unless ($n = getnetbyname($net)) { + warn "$0: no such net: $net\n"; + next; + } + + printf "\n%s is %s%s\n", + $net, + lc($n->name) eq lc($net) ? "" : "*really* ", + $n->name; + + print "\taliases are ", join(", ", @{$n->aliases}), "\n" + if @{$n->aliases}; + + # this is stupid; first, why is this not in binary? + # second, why am i going through these convolutions + # to make it looks right + { + my @a = unpack("C4", pack("N", $n->net)); + shift @a while @a && $a[0] == 0; + printf "\taddr is %s [%d.%d.%d.%d]\n", $n->net, @a; + } + + if ($n = getnetbyaddr($n->net)) { + if (lc($n->name) ne lc($net)) { + printf "\tThat addr reverses to net %s!\n", $n->name; + $net = $n->name; + redo; + } + } + } + +=head1 NOTE + +While this class is currently implemented using the Class::Struct +module to build a struct-like class, you shouldn't rely upon this. + +=head1 AUTHOR + +Tom Christiansen |