Re: Minor feature additions

[Chris Backas <chb@xxxxxxxxxxxxxxxxxx>]

> Chris Backas a écrit :
>
> > > >
> > > Hmm, I think we don't have to add a function but rather understand  
> > > why
> > > it tries to make a DNS lookup even when we give out an IP address.
> > > Almost no highlevel framework adds an option to hint the resolver  
> > > that
> > > we gave a numeric IP, I think it should not be exported to the  
> > > public
> > > functions.
> > > I'm going to see what we do wrong, in worst case, doing a regexplike
> > > search on [0-9]+\.[0-9]+\.[0-9]+\.[0-9]+ is not that hard. (a bit  
> > > harder
> > > for ipv6).
> > In my own modification I did exactly that, had it detect when the  
> > host name 'looks like' an IP address, and then set the flag.
> > getaddrinfo(), at least on Mac OS X (where I'm using this) isn't  
> > clear about its resolution behavior. It says in the man page:
> > "An acceptable value for nodename is either a valid host name or a  
> > numeric host address string consisting of a dotted decimal IPv4  
> > address or an IPv6 address."
> > But that doesn't say how it treats them. Experimentally its seems  
> > to be "assume this is a host name, and if that fails then try it as  
> > a numeric address".  The AI_NUMERICHOST flag says:
> > "AI_NUMERICHOST  If the AI_NUMERICHOST bit is set, it indicates  
> > that nodename should be treated as a numeric string defining an  
> > IPv4 or IPv6 address and no name resolution should be attempted."
> > My reading of that is that the flag wouldn't need to exist if  
> > getaddrinfo() itself made any attempt to realize that the supplied  
> > value is not a host name.
>
> Hello Chris,
>
> I have implemented the change as we discussed, by a regular  
> expression matching in the connect code. look commit  
> 052073c36d33089d3a99992840c88c6245461813.
>
> I used extended posix regular expressions which I think are very  
> standard. Gladiac, do we need a particular cmake fix for  
> conditionnal compilation ?
>
> Thanks,
>
> Aris

Hi Aris,

I looked over this change, and "kicked the tires" a little. Looks  
good, and seems to work fine.  Just wondering about IPv6 addresses  
though. My own approach didn't handle these either, and the worst that  
happens is that the delay occurs on an IPv6 host since it's not  
recognized as an IP Address. So, no big deal, but perhaps the comments  
should reference it.  Just a thought.

Chris Backas