Commit | Line | Data |
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36477c24 | 1 | package Net::netent; |
2 | use strict; | |
3 | ||
17f410f9 GS |
4 | use 5.005_64; |
5 | our(@EXPORT, @EXPORT_OK, %EXPORT_TAGS); | |
36477c24 | 6 | BEGIN { |
7 | use Exporter (); | |
36477c24 | 8 | @EXPORT = qw(getnetbyname getnetbyaddr getnet); |
9 | @EXPORT_OK = qw( | |
10 | $n_name @n_aliases | |
11 | $n_addrtype $n_net | |
12 | ); | |
13 | %EXPORT_TAGS = ( FIELDS => [ @EXPORT_OK, @EXPORT ] ); | |
14 | } | |
15 | use vars @EXPORT_OK; | |
16 | ||
8cc95fdb | 17 | # Class::Struct forbids use of @ISA |
18 | sub import { goto &Exporter::import } | |
19 | ||
20 | use Class::Struct qw(struct); | |
36477c24 | 21 | struct 'Net::netent' => [ |
22 | name => '$', | |
23 | aliases => '@', | |
24 | addrtype => '$', | |
25 | net => '$', | |
26 | ]; | |
27 | ||
28 | sub populate (@) { | |
29 | return unless @_; | |
30 | my $nob = new(); | |
31 | $n_name = $nob->[0] = $_[0]; | |
32 | @n_aliases = @{ $nob->[1] } = split ' ', $_[1]; | |
33 | $n_addrtype = $nob->[2] = $_[2]; | |
34 | $n_net = $nob->[3] = $_[3]; | |
35 | return $nob; | |
36 | } | |
37 | ||
38 | sub getnetbyname ($) { populate(CORE::getnetbyname(shift)) } | |
39 | ||
40 | sub getnetbyaddr ($;$) { | |
41 | my ($net, $addrtype); | |
42 | $net = shift; | |
43 | require Socket if @_; | |
44 | $addrtype = @_ ? shift : Socket::AF_INET(); | |
45 | populate(CORE::getnetbyaddr($net, $addrtype)) | |
46 | } | |
47 | ||
48 | sub getnet($) { | |
49 | if ($_[0] =~ /^\d+(?:\.\d+(?:\.\d+(?:\.\d+)?)?)?$/) { | |
50 | require Socket; | |
51 | &getnetbyaddr(Socket::inet_aton(shift)); | |
52 | } else { | |
53 | &getnetbyname; | |
54 | } | |
55 | } | |
56 | ||
57 | 1; | |
58 | __END__ | |
59 | ||
60 | =head1 NAME | |
61 | ||
62 | Net::netent - by-name interface to Perl's built-in getnet*() functions | |
63 | ||
64 | =head1 SYNOPSIS | |
65 | ||
66 | use Net::netent qw(:FIELDS); | |
67 | getnetbyname("loopback") or die "bad net"; | |
68 | printf "%s is %08X\n", $n_name, $n_net; | |
69 | ||
70 | use Net::netent; | |
71 | ||
72 | $n = getnetbyname("loopback") or die "bad net"; | |
73 | { # there's gotta be a better way, eh? | |
74 | @bytes = unpack("C4", pack("N", $n->net)); | |
75 | shift @bytes while @bytes && $bytes[0] == 0; | |
76 | } | |
77 | printf "%s is %08X [%d.%d.%d.%d]\n", $n->name, $n->net, @bytes; | |
78 | ||
79 | =head1 DESCRIPTION | |
80 | ||
81 | This module's default exports override the core getnetbyname() and | |
82 | getnetbyaddr() functions, replacing them with versions that return | |
83 | "Net::netent" objects. This object has methods that return the similarly | |
84 | named structure field name from the C's netent structure from F<netdb.h>; | |
85 | namely name, aliases, addrtype, and net. The aliases | |
86 | method returns an array reference, the rest scalars. | |
87 | ||
88 | You may also import all the structure fields directly into your namespace | |
89 | as regular variables using the :FIELDS import tag. (Note that this still | |
90 | overrides your core functions.) Access these fields as variables named | |
91 | with a preceding C<n_>. Thus, C<$net_obj-E<gt>name()> corresponds to | |
92 | $n_name if you import the fields. Array references are available as | |
93 | regular array variables, so for example C<@{ $net_obj-E<gt>aliases() | |
94 | }> would be simply @n_aliases. | |
95 | ||
8dcee03e | 96 | The getnet() function is a simple front-end that forwards a numeric |
36477c24 | 97 | argument to getnetbyaddr(), and the rest |
98 | to getnetbyname(). | |
99 | ||
100 | To access this functionality without the core overrides, | |
101 | pass the C<use> an empty import list, and then access | |
102 | function functions with their full qualified names. | |
103 | On the other hand, the built-ins are still available | |
104 | via the C<CORE::> pseudo-package. | |
105 | ||
106 | =head1 EXAMPLES | |
107 | ||
108 | The getnet() functions do this in the Perl core: | |
109 | ||
110 | sv_setiv(sv, (I32)nent->n_net); | |
111 | ||
112 | The gethost() functions do this in the Perl core: | |
113 | ||
114 | sv_setpvn(sv, hent->h_addr, len); | |
115 | ||
116 | That means that the address comes back in binary for the | |
117 | host functions, and as a regular perl integer for the net ones. | |
118 | This seems a bug, but here's how to deal with it: | |
a6006777 | 119 | |
36477c24 | 120 | use strict; |
121 | use Socket; | |
122 | use Net::netent; | |
3cb6de81 | 123 | |
36477c24 | 124 | @ARGV = ('loopback') unless @ARGV; |
3cb6de81 | 125 | |
36477c24 | 126 | my($n, $net); |
3cb6de81 | 127 | |
36477c24 | 128 | for $net ( @ARGV ) { |
3cb6de81 | 129 | |
36477c24 | 130 | unless ($n = getnetbyname($net)) { |
131 | warn "$0: no such net: $net\n"; | |
132 | next; | |
133 | } | |
3cb6de81 | 134 | |
36477c24 | 135 | printf "\n%s is %s%s\n", |
136 | $net, | |
137 | lc($n->name) eq lc($net) ? "" : "*really* ", | |
138 | $n->name; | |
3cb6de81 | 139 | |
36477c24 | 140 | print "\taliases are ", join(", ", @{$n->aliases}), "\n" |
141 | if @{$n->aliases}; | |
3cb6de81 | 142 | |
36477c24 | 143 | # this is stupid; first, why is this not in binary? |
144 | # second, why am i going through these convolutions | |
145 | # to make it looks right | |
146 | { | |
147 | my @a = unpack("C4", pack("N", $n->net)); | |
148 | shift @a while @a && $a[0] == 0; | |
149 | printf "\taddr is %s [%d.%d.%d.%d]\n", $n->net, @a; | |
150 | } | |
3cb6de81 | 151 | |
36477c24 | 152 | if ($n = getnetbyaddr($n->net)) { |
153 | if (lc($n->name) ne lc($net)) { | |
154 | printf "\tThat addr reverses to net %s!\n", $n->name; | |
155 | $net = $n->name; | |
156 | redo; | |
157 | } | |
158 | } | |
159 | } | |
a6006777 | 160 | |
36477c24 | 161 | =head1 NOTE |
162 | ||
8cc95fdb | 163 | While this class is currently implemented using the Class::Struct |
36477c24 | 164 | module to build a struct-like class, you shouldn't rely upon this. |
165 | ||
166 | =head1 AUTHOR | |
167 | ||
168 | Tom Christiansen |