Created attachment 1240354 [details]
test perl file

Briefly looking at the HTTP::Daemon code, I think HTTP::Daemon does not support IPv6 and it should be ported from IO::Socket::INET to IO::Socket::IP.

Regarding the attached reproducer, it uses HTTP::Daemon::SSL not delivered by Red Hat. If I use HTTP-Daemon-SSL-1.04 from CPAN, I even cannot start the reproducer because it complains that "[::]" is unknown service ("unable to create web socket: Name or service not known at test.pl"). If I correct the LocalAddr to "::", then I can only get bug report from HTTP/Daemon.pm line 51 about the same Socket::inet_ntoa issue. Not line 48. How do you invoke an HTTP client?

Created attachment 1241332 [details]
Proposed fix

Created attachment 1241785 [details]
Proposed fix

How to test:

(1) Create an HTTP::Daemon object with an IPv6 listen address and check that url() method on the object returns HTTP URL a client can connect to. E.g:

 $ perl -MHTTP::Daemon -e '$d=HTTP::Daemon->new(LocalAddr=>q{::1}) or die $@; print $d->url, qq{\n}'

Before: It reports this error:
HTTP::Daemon: Bad hostname '::1' at -e line 1.

After: It prints an URL with "::1" as a host name:
http://[::1]:34389/

You try different listen addresses like "127.0.0.1", "::", "0.0.0.0". Please note that in case of unspecified address a hostname is returned.

Hello Petr,

Can I have a test package pls. A brewbuild would do.

Thanks.

Unsupported testing build is available on <http://people.redhat.com/~ppisar/perl-HTTP-Daemon-6.01-6.el7/>.

Any chance of getting this into RHEL 6?

This package is not in RHEL 6.

(In reply to Petr Pisar from comment #11)
> This package is not in RHEL 6.

I see that /usr/share/perl5/vendor_perl/HTTP/Daemon.pm is part of perl-libwww-perl
So, any chance of getting into perl-libwww-perl? I wanted to confirm that as we are already into Prod phase 2 for RHEL 6.

If possible, I shall open up a seperate BZ for that.

Thanks

You are right. The module lives in different package. But I'm reluctant to update it in RHEL-6. First the RHEL-6 HTTP::Daemon documentation clearly states that it supports IPv4 only:

  The C<HTTP::Daemon> is a subclass of C<IO::Socket::INET>

and second RHEL-6 is beyond accepting new features.

(In reply to Petr Pisar from comment #16)
> This is because IO::Socket::IP behaves differently from IO::Socket::INET.
> This applies not only to empty string, but also to undef value, or invalid
> addresses like q{0.1}. None of the HTTP::Daemon, IO::Socket::IP, and
> IO::Socket::INET specifies behavior in these cases.
> 
Reported to IO-Socket-IP upstream <https://rt.cpan.org/Public/Bug/Display.html?id=123069>.

(In reply to Petr Pisar from comment #16)
> I can introduce special handling for undef and empty string to behave as the
> previous implementation, but it's impossible to emulate all the other corner
> cases.
> 
Actually this does not work with perl-IO-Socket-IP-0.21-4.el7.noarch because that IO::Socket::IP cannot deal with non-existing LocalAddr argument:

$ perl -MIO::Socket::IP -e '$a=IO::Socket::IP->new(Proto=>q{tcp}, Listen=>1) or die qq{Error: $@\n}; print `ss -tnlp`'
Error: 

While it works with latest upstream IO-Socket-IP-0.39:

$ perl -MIO::Socket::IP -e '$a=IO::Socket::IP->new(Proto=>q{tcp}, Listen=>1) or die qq{Error: $@\n}; print `ss -tnlp`'
State      Recv-Q Send-Q Local Address:Port               Peer Address:Port              
LISTEN     0      128          *:22                       *:*                  
LISTEN     0      1           :::36309                   :::*                   users:(("perl",pid=13539,fd=3))
LISTEN     0      128         :::22                      :::*                  

This incompatibility was probably fixed in IO-Socket-IP-0.25 <https://rt.cpan.org/Public/Bug/Display.html?id=91982> and to be fixed in perl-IO-Socket-IP before we can proceed with this perl-HTTP-Daemon bug.

Just a demonstration how it affects perl-HTTP-Daemon:

Patched perl-HTTP-Daemon with broken perl-IO-Socket-IP:

$ perl -Ilib -MHTTP::Daemon -e '$d=HTTP::Daemon->new() or die $@; print $d->url, qq{\n}'
Died at -e line 1.

Previous perl-HTTP-Daemon on IO::Socket-INET:

[test@rhel-7-5 HTTP-Daemon-6.01]$ perl -MHTTP::Daemon -e '$d=HTTP::Daemon->new() or die $@; print $d->url, qq{\n}'
http://rhel-7-5:41466/

(In reply to Petr Pisar from comment #18)
> (In reply to Petr Pisar from comment #16)
> > I can introduce special handling for undef and empty string to behave as the
> > previous implementation, but it's impossible to emulate all the other corner
> > cases.
> > 
> Actually this does not work with perl-IO-Socket-IP-0.21-4.el7.noarch because
> that IO::Socket::IP cannot deal with non-existing LocalAddr argument:
>
[...] 
> This incompatibility was probably fixed in IO-Socket-IP-0.25
> <https://rt.cpan.org/Public/Bug/Display.html?id=91982> and to be fixed in
> perl-IO-Socket-IP before we can proceed with this perl-HTTP-Daemon bug.

Yes, it was fixed and I have fix prepared in bug #1492760. With the fixed perl-IO-Socket-IP, the special handling for empty and undefined strings works.

Created attachment 1327543 [details]
Proposed fix to handle undefined and empty string LocalAddr

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2018:0665