| Subject: | Mishandling of valid IPv6 address in ip_is_ipv6 |
| Date: | Tue, 12 Oct 2010 19:08:29 +0200 |
| To: | bug-Net-IP [...] rt.cpan.org |
| From: | Test <Test [...] globis.net> |
I have been building my own IPv6 libraries on top of Net::IP. Thanks
very much for the basis.
I think I have found a bug in the Net::IP library during my testing.
The subroutine ip_is_ipv6 seems to be incorrectly handling prefixes
where the last valid hexseq of 4 hex digits of 0000 is replaced by "::".
That in turn is messing up address expansion as it cannot determine what
sort of address it is (v4 or v6).
Quoting rfc3513
The use of "::" indicates one or more groups of 16 bits of zeros.
The "::" can only appear once in an address. The "::" can also be
used to compress leading or trailing zeros in an address.
Here's my test harness. The last test gives the unexpected result.
I would expect that the string "2001:2:3:4:5:6:7::" is a valid IPv6
address and represents the expanded address prefix
"2001:0002:0003:0004:0005:0006:0007:0000" but the routine currently
returns undef, as it seems to be getting confused about the last
trailing colon. Haven't worked out exactly why yet, but I thought I'd
report it to see what you thought about this.
Wouldn't it potentially be better to use the regexp IPv6_re from
Regexp::IPv6 that includes the full grammar from rfc2373?
-------002_base.t--------
# -*- perl -*-
# t/002_base.t - test base routines
use strict;
use warnings;
use Test::More qw(no_plan);
BEGIN { use_ok( 'Net::IP' ); }
my $expected;
my $address
use Net::IP qw(ip_is_ipv6);
$address=ip_is_ipv6('2001:2:3:4:5:6:7:8');
$expected=1;
is ($address,$expected,"Check ipv6 unicast 2001:2:3:4:5:6:7:8");
$address=ip_is_ipv6('::1');
$expected=1;
is ($address,$expected,"Check ipv6 loopback ::1");
$address=ip_is_ipv6('2001:2:3:4:5:6:7:8:9');
$expected=0;
is ($address,$expected,"Check invalid ipv6 unicast 2001:2:3:4:5:6:7:8:9
= too long");
$expected=0;
is ($address,$expected,"Check invalid ipv6 unicast 2001:2::3:4::5:6 = 2
sets of colons");
$address=ip_is_ipv6('2001:2:3:4:5:6::');
$expected=1;
is ($address,$expected,"Check ipv6 unicast prefix 2001:2:3:4:5:6::");
$address=ip_is_ipv6('2001:2:3:4:5:6:7::');
$expected=1;
is ($address,$expected,"Check ipv6 unicast prefix 2001:2:3:4:5:6:7::");