On 11/19/2013 10:48 PM, Brian Utterback wrote: > On 11/19/2013 3:40 PM, Danny Mayer wrote: >> You should not be using literal IP addresses of either flavor without >> also setting the AI_NUMERICHOST flag otherwise it tries to do a DNS >> lookup. That's poorly written code otherwise. >> >> Danny > > Not so. The getaddrinfo function will recognize literal addresses and > merely convert them. The point is that for something like ssh or any > other network utility, the user is supposed to give a hostname, but in > virtually all cases you can give a literal address and the application > does not have to treat it differently. If you read the ipng mailing > list, you will see that they were trying to make the whole process of > writing a network application simpler, with getaddrinfo doing the heavy > lifting for all of the major cases. At the same time they were trying to > allow applications to work on either IPv4 or IPv6 systems without > changing them, or dual stack or any combination. But no matter what they > did there were edge cases that needed to work differently. > > Brian Utterback
That wasn't true the last time I had to read the source code for getaddrinfo(). A number of years ago I was debugging a problem with ntpd on a Unix box, I think it was FreeBSD, and it was doing a DNS Lookup. The ntpd code checks the string and sees if it is an IP address and takes the appropriate action before calling getaddrinfo(), at least it used to. Danny _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
