goldsi...@gmx.de wrote: > On 12.11.2018 01:04, Craig McQueen wrote: > > DHCP option 120 provides SIP server address(es), which may be an IP > address or a DNS name. If it's a DNS name, then it is already encoded in the > encoding used for DNS look-ups (RFC 1035). See RFC 3361 section 3.1. > > > > What is the best way to look up such a name via lwIP? > > The only lookup lwIP supports is the normal dotted string notation. > > > Shall I convert it from the RFC 1035 encoding to the normal dotted string > notation, and not fret about the perceived inefficiency that lwIP will just > convert it back to RFC 1035 encoding? (it's converted in dns_send().) > Alternatively, core/dns.c could be modified to provide an API function that > takes a hostname in the RFC 1035 encoding. > > dns.c implements a cache. Taking one name as RFC1035 is not enough: > future comparisons must match it, too. So either we're buffering in > RFC1035 or in dotted strings. I'd say given the length of such names (and > unless there's a different point in keeping names in RFC1035 format), it's > probably not worth changing anything from the current state...
I looked into DNS internationalization and Punycode. I can't see any problem with internationalization with either RFC1035 encoding or dotted string notation. So I think that's not a concern, regardless of what RFC3361 stated about internationalization. So, I think the most straight-forward solution is for my code to just convert from the RFC 1035 encoding to dotted string notation, and avoid fretting about the double conversion. -- Craig McQueen _______________________________________________ lwip-users mailing list lwip-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/lwip-users
