I would also add to Dan's comment a note about: > Note that for some resolvers, it may be necessary to back translate their > response code to the DNS RFCs'. But that work ends up in curllib, not in the > application.
Assuming that it would be always possible to translate back resolver-specific codes into some general "DNS codes" (although it might be not always the case), such translation logic will create a dependency on the resolver. So, whenever the resolver add/modify/remove its internal codes in a new version, libcurl will have to update the translation layer (if it is implemented there) to keep it up to date. And for multiple resolvers, it will be a maintenance mess. On the other hand, the application knows which resolver (and which specific version) it uses, so it can update the translation layer (code-to-text, if it needs it) once it updates the resolver version. Returning an opaque resolver code in case of host resolution failures is enough debug information for application developers to build application-specific resolver translation layers, which will be aligned with resolver versions their application is using (i.e. specific version of c-ares etc). -----Original Message----- From: curl-library <curl-library-boun...@lists.haxx.se> On Behalf Of Dan Fandrich via curl-library Sent: Tuesday, April 19, 2022 3:26 PM To: curl-library@lists.haxx.se Cc: Dan Fandrich <d...@coneharvesters.com> Subject: Re: Feature request about curlinfo option returning resolver status/error code On Tue, Apr 19, 2022 at 04:14:23PM -0400, Timothe Litt via curl-library wrote: > No. No need to invent abstract codes. Use the DNS RCODE + (if > available) the ENS EDNS0 EDE (RFC8914). But do those codes include errors that only a local resolver might face? Things like access or syntax errors on /etc/resolv.conf, inability to connect to the local resolver daemon, or out of memory? In just looking at the set of c-ares error codes, they're defined in sections with 6 in the "server error codes" section and 11 in the "locally-generated error codes" section. -- Unsubscribe: https://lists.haxx.se/listinfo/curl-library Etiquette: https://curl.haxx.se/mail/etiquette.html -- Unsubscribe: https://lists.haxx.se/listinfo/curl-library Etiquette: https://curl.haxx.se/mail/etiquette.html
