ddclient / ddclient

There is a confusing line of code at

Line 2573 in afa1275

my $ipversion = ($params{ipversion}) ? int($params{ipversion}) : 0;

Which outputs at

Line 2642 in afa1275

    
           warning("curl cannot connect to %s://%s using IPv%s",${protocol},${server},$ipversion);

as well as

ddclient/ddclient.in

Line 2604 in afa1275

debug("ip ver = %s", $ipversion);

The problem with this is that when there is an error, the script outputs something like the following:

WARNING:  CURL error (6) Couldn't resolve host. The given remote host was not resolved.
WARNING:  curl cannot connect to https://api.gandi.net/ using IPv0
FAILED:   @ -- Could not connect to api.gandi.net.

This could lead users to falsely believe that the issue is that we are trying to use a non-existent IP version.

I'm confused about what the intent of setting it to 0 is. Is it to indicate that we are supposed to use all available protocols (meaning 4 and 6)? If that is the case, wouldn't it be better to do something like

my $ipversion = ($params{ipversion}) ? int($params{ipversion}) : "4/6";

instead then? Obviously would need to string-ify the only 4 and only 6 cases, but this would better indicate to the user what is going on.

And if this isn't the case, if we don't read an IP version number from $params{ipversion}, shouldn't we handle that error instead of continuing with 0?

The ipversion parameter to geturl() is only used to force IPv4/6 respectively. So neither being forced (ipversion = 0) is a valid usecase of the function. The log messages should probably be reworded to omit the "using IPv*" part if neither IP version option is forced.

Incorrectly reports using non-existent IP version 0