From: Philip Guenther <guenther@gmail.com>
Subject: Re: gethostbyname(3) should always set ai_canonname
To: tech <tech@openbsd.org>
Date: Tue, 20 Aug 2024 16:47:39 -0700

Makes sense to me.  ok guenther@

On Tue, Aug 20, 2024 at 5:58 AM Florian Obser <florian@openbsd.org> wrote:
>
> Consulting the Book of Armaments:
>
> | If nodename is not null, and if requested by the AI_CANONNAME flag, the
> | ai_canonname field of the first returned addrinfo structure shall point
> | to a null-terminated string containing the canonical name corresponding
> | to the input nodename; if the canonical name is not available, then
> | ai_canonname shall refer to the nodename argument or a string with the
> | same contents.
> | --- https://pubs.opengroup.org/onlinepubs/9799919799/functions/freeaddrinfo.html
>
> Our documentation also claims that ai_canonname is set:
>
>                     AI_CANONNAME    If the AI_CANONNAME bit is set, a
>                                     successful call to getaddrinfo() will
>                                     return a NUL-terminated string containing
>                                     the canonical name of the specified host
>                                     name in the ai_canonname element of the
>                                     first addrinfo structure returned.
>
>
> OK?
>
> (There is a check in addrinfo_add to see if the AI_CANONNAME flag is
> set.)
>
> diff --git lib/libc/asr/getaddrinfo_async.c lib/libc/asr/getaddrinfo_async.c
> index 23262f5163f..d5cf56cd0d7 100644
> --- lib/libc/asr/getaddrinfo_async.c
> +++ lib/libc/asr/getaddrinfo_async.c
> @@ -280,7 +280,7 @@ getaddrinfo_async_run(struct asr_query *as, struct asr_result *ar)
>                             as->as.ai.hostname) == -1)
>                                 continue;
>
> -                       if ((r = addrinfo_add(as, &sa.sa, NULL)))
> +                       if ((r = addrinfo_add(as, &sa.sa, as->as.ai.hostname)))
>                                 ar->ar_gai_errno = r;
>                         break;
>                 }
> @@ -681,7 +681,7 @@ addrinfo_from_pkt(struct asr_query *as, char *pkt, size_t pktlen)
>                 if (as->as.ai.hints.ai_flags & AI_CANONNAME) {
>                         _asr_strdname(rr.rr_dname, buf, sizeof buf);
>                         buf[strlen(buf) - 1] = '\0';
> -                       c = res_hnok(buf) ? buf : NULL;
> +                       c = res_hnok(buf) ? buf : as->as.ai.hostname;
>                 } else if (as->as.ai.hints.ai_flags & AI_FQDN)
>                         c = as->as.ai.fqdn;
>                 else
>
>
> --
> In my defence, I have been left unsupervised.
>