Hi Jinmei, Thanks for bringing up this point. Please see my comment below.
> > As requested, here are my comments about the addrselect-api draft. > > One additional comment (I think this has not been pointed out by > anyone. sorry if not): > > Using new flags for ai_flags of getaddrinfo() may have a compatibility > issue. RFC3493 says: > > The ai_flags field to which hints parameter points shall be set to > zero or be the bitwise-inclusive OR of one or more of the values > AI_PASSIVE, AI_CANONNAME, AI_NUMERICHOST, AI_NUMERICSERV, > AI_V4MAPPED, AI_ALL, and AI_ADDRCONFIG. > > I personally don't think this prohibits the use of other flags, but > some existing implementations seem to interpret this part in the > strictest way. Those return an error of EAI_BADFLAGS if an unknown > flag is specified in hints.ai_flags. getaddrinfo contained in BSD > variants and in the "libbind" library of ISC BIND behave this way. > For those implementations, applications that use this API extensions > will simply not be working, which is probably what we want to avoid. > It may vary implementation to implementation. I can't think of any other way than changing the implementation to support the new API. Those implementations that don't support the new AI_* flag will return EAI_BADFLAGS with getaddrinfo(). I'd say that similar could be true for new socket options. > However, I cannot think of any other solutions than having these > implementations change the behavior. So, we should probably first > agree on what the implementation should do for unknown flags and > describe the clarification in this document. As you mentioned that RFC3494 already defines : [EAI_BADFLAGS] The flags parameter had an invalid value. Are you implying that the document (RFC3494) should clarify that the implementation can return EAI_BADFLAGS for unknown flag value? If so, it makes sense to me. However, I'd interpret unknown value as invalid value as well. -Samita -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
