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Description of problem:
The perl-net-ping module delivers the wrong return value on failing DNS name lookup


Version-Release number of selected component (if applicable):
- Tested with perl-Net-Ping-2.55-419.el8.noarch in RHEL 8.4
- Found by a customer on RHEL 8.2

How reproducible:
- With non-existing dns hosts

Steps to Reproduce:
1. install perl-Net-Ping-2.55-419.el8.noarch
2. create example perl script:
   
   use Net::Ping;
   $ping = Net::Ping->new('tcp');
   $result = $ping->ping('blah.example.com'); # host does not exist in DNS.
   if (defined $result && $result)
      { print "OK\n"; }
   else
      { print "ERROR\n"; }

3. run script

Actual results:
Error message is displayed:
getaddrinfo(blah.lnx.aaxc.org,,AF_INET) failed - Name or service not known at test.pl line 3.

Expected results:
The output should be "ERROR"

Additional info:
Looks like this has been fixed upstream: https://metacpan.org/dist/Net-Ping/changes (line 60)

------------------------------------------------
2.68  Wed Jun 27 11:55:06 CEST 2018 (rurban)
       Bugfixes
       - Fixed _resolv return value on failing DNS name lookup. (GH #12 nlv02636)
------------------------------------------------

Thank you for report. I can confirm the issue.

perl-Net-Ping is subpackage of perl.

These two changes has to be backported to solve the issue. 

2.68  Wed Jun 27 11:55:06 CEST 2018 (rurban)
       Bugfixes
       - Fixed _resolv return value on failing DNS name lookup. (GH #12 nlv02636)

2.67  Mon Jun 25 18:10:42 CEST 2018 (rurban)
       Bugfixes
       - Change croak on failing name lookup to return undef,
         matching the documentation.
         Fixes the regression from 2.43, RT #124830


After the fix, final result of the reproducer will be:
# perl bz1973030.pl 
getaddrinfo(blah.example.com,,AF_INET) failed - Name or service not known at /usr/share/perl5/Net/Ping.pm line 1861.
ERROR

Created attachment 1791764 [details]
Replace croak by carp

Created attachment 1791765 [details]
Fix _resolv return value

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 (perl bug fix and enhancement update), 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-2021:4459