prefer ip address for host in $d->url

[skaji]

This PR will fix #38, that is "Sometimes cannot be accessed via $d->url".

When we are not able to access servers via $d->url

Let's say we create an HTTP::Daemon server by

my $d = HTTP::Daemon->new()

Then, $d->sockaddr is INADDR_ANY (0.0.0.0) or IN6ADDR_ANY (::1), so $d->url returns http://hostname:XXX/, where hostname is the hostname of the local machine returned by Sys::Hostname::hostname, and XXX is some port number.

Then, there are 2 cases that we are not able to access the server via $d->url:

• case1: The hostname is not resolvable to IP addresses.
  • This can be seen in OpenBSD result by jkeenan
• case2: The hostname is resolved to IPv4, but $d restricts connections to IPv6 only.
  • At least, on OpenBSD, IPv6 sockets are always IPv6-only. See manpage.
  • This can be seen in FreeBSD result by jkeenan

How to fix it

• if $d->sockhost is '0.0.0.0', then use '127.0.0.1' for host in $d->url
• if $d->sockhost is '::', then use '::1' for host in $d->url
• and in any cases, use ip address (that is $d->sockhost), not hostname or domain.

Backward compatibility

Although this PR will fix #38, we should note that this PR may break some use cases.

As I mentioned above, currently, when we create HTTP::Daemon by my $d = HTTP::Daemon->new, $d->url becomes http://hostname:XXX. But after this PR, $d->url will become http://127.0.0.1:XXX or http://[::1]:XXX.

Apparently, the ip addresses 127.0.0.1 and ::1 are reasonable only in the local machine. On the other hand, the hostname may be reasonable not only in local machine, but also in remote machines.

So this PR may cause an issue "we are not able to access servers from remote machines via $d->url".

[jkeenan]

So far so good. I applied your patch to existing HTTP-Daemon-6.07 and called the result 6.07_001. I added one more debugging line to your first test program so as to print the perlversion. Results on 3 BSDs:

FreeBSD

$ uname -mrs
FreeBSD 11.2-STABLE amd64

$ perl -I/usr/home/jkeenan/learn/perl/HTTP-Daemon-6.07-patched/lib skaji-http-daemon-gh38-test.pl
Perl version:           v5.28.2
HTTP::Daemon version:   6.07_001
HTTP::Response version: 6.18
HTTP GET http://[::1]:64633/
200 OK

$ bleadperl -I/usr/home/jkeenan/learn/perl/HTTP-Daemon-6.07-patched/lib skaji-http-daemon-gh38-test.pl
Perl version:           v5.31.12
HTTP::Daemon version:   6.07_001
HTTP::Response version: 6.22
HTTP GET http://[::1]:10182/
200 OK

OpenBSD

$ uname -mrs
OpenBSD 6.6 amd64

$ perl -I/home/jkeenan/learn/perl/HTTP-Daemon-6.07-patched/lib skaji-http-daemon->
Perl version:           v5.28.2
HTTP::Daemon version:   6.07_001
HTTP::Response version: 6.13
HTTP GET http://127.0.0.1:22871/
200 OK

$ bleadperl -I/home/jkeenan/learn/perl/HTTP-Daemon-6.07-patched/lib skaji-http-da>
Perl version:           v5.31.12
HTTP::Daemon version:   6.07_001
HTTP::Response version: 6.22
HTTP GET http://127.0.0.1:6970/
200 OK

NetBSD

$ uname -mrs
NetBSD 8.0 amd64

$ perl -I/home/jkeenan/learn/perl/HTTP-Daemon-6.07-patched/lib   skaji-http-daemon-gh38-test.pl
Perl version:           v5.30.2
HTTP::Daemon version:   6.07_001
HTTP::Response version: 6.18
HTTP GET http://[::1]:65393/
200 OK

$ bleadperl -I/home/jkeenan/learn/perl/HTTP-Daemon-6.07-patched/lib   skaji-http-daemon-gh38-test.pl
Perl version:           v5.32.0
HTTP::Daemon version:   6.07_001
HTTP::Response version: 6.24
HTTP GET http://[::1]:65391/
200 OK

I have not yet had an opportunity to run the Test-Smoke test suite with this patch but will try to do so in the coming days. Please let me know what other testing procedures you might need.

Thank you very much. Jim Keenan

[jkeenan]

So far so good. I applied your patch to existing HTTP-Daemon-6.07 and called the result 6.07_001. I added one more debugging line to your first test program so as to print the perlversion. Results on 3 BSDs:

[snip]

I have not yet had an opportunity to run the Test-Smoke test suite with this patch but will try to do so in the coming days. Please let me know what other testing procedures you might need.

I have now run the Test-Smoke test suite with your patched HTTP::Daemon. Please see: https://rt.cpan.org/Ticket/Display.html?id=132642#txn-1898592

These results suggest that while LWP::UserAgent and HTTP::Tiny "play well" with the patched version of HTTP::Daemon, HTTP::Lite has problems.

Thank you very much. Jim Keenan

[oalders]

Thanks everyone!