=
n
>>>>> 'struct
>>>>>>> in6_addr'
>>>>>>>   95 |                 ipv6->sin6_addr.s6_addr32[3] =3D 0;
>>>>>>>      |                 ~~~~~~~~~~~~~~~ ^
>>>>>>> but yet, we kinda define them, but only for the kernel and boot l=
oader:
>>>>>>> /*
>>>>>>> * IPv6 address
>>>>>>> */
>>>>>>> struct in6_addr {
>>>>>>>        union {
>>>>>>>                uint8_t         __u6_addr8[16];
>>>>>>>                uint16_t        __u6_addr16[8];
>>>>>>>                uint32_t        __u6_addr32[4];
>>>>>>>        } __u6_addr;                    /* 128-bit IP6 address */
>>>>>>> };
>>>>>>>
>>>>>>> #define s6_addr   __u6_addr.__u6_addr8
>>>>>>> #if defined(_KERNEL) || defined(_STANDALONE) /* XXX nonstandard *=
/
>>>>>>> #define s6_addr8  __u6_addr.__u6_addr8
>>>>>>> #define s6_addr16 __u6_addr.__u6_addr16
>>>>>>> #define s6_addr32 __u6_addr.__u6_addr32
>>>>>>> #endif
>>>>>>>
>>>>>>> I'm wondering if anybody why it's like that? git blame suggests w=
e
>>>>> imported
>>>>>>> that from kame, with
>>>>>>> only tweaks by people that are now deceased*.*
>>>>>>>
>>>>>>> Why not just expose them?
>>>>>>
>>>>>> Looks like only s6_addr is specified in the RFCs (2553 and 3493). =
 Oddly,
>>>>>> though, the RFCs give an example implementation using that union w=
ith
>>>>>> different element names (like _S6_u8), and show the one #define.
>>>>>> Similarly, POSIX specifies only s6_addr, but it allows other membe=
rs
>>>>>> of the structure, so I don't see a problem with exposing them all =
even
>>>>>> in a POSIX environment.
>>>>>>
>>>>>> I would have no objection to exposing all four definitions, especi=
ally
>>>>>> if Linux apps use them.
>>>>>
>>>>> I put the change, along with an explanatory comment, in
>>>>> https://reviews.freebsd.org/D44979.  Comments welcome.
>>>>>
>>>>
>>>> Thanks! I was testing a similar change, but I like yours better... t=
hough
>>>> maybe
>>>> we should just make it visible when __BSD_VISIBLE is true.... I'll h=
ave to
>>>> look
>>>> closely at what Linux does here... I think they have it always visib=
le, or
>>>> at least
>>>> musl does that (glibc is harder to track down due to the many layers=
 of
>>>> indirection).
>>>
>>> I thought briefly about __BSD_VISIBLE, but wasn't sure it was necessa=
ry.
>>> Let me know what you find out.  I think it should work either way; in=
=2Eh
>>> includes cdefs.h, so it's guaranteed to have been included.
>>
>> If the -ms-extensions option is used with gcc or clang, this ugliness =
can
>> go away as you can have nested anonymous unions or -structs and their =
fields
>> can be referenced as if they're directly in the parent struct/union.
>>
>> [IIRC this was present in Plan9 C from very early on. Also in C11 or l=
ater]
>>
>> True. In fact c11 and newer doesn't need anything on the command line =
here. If it were only in the kernel then I'd chamge it like thay while I =
was here... but lots of code in ports will specify c99 + POSIX 2001 and t=
o compile there your only hope is this construct....
>
> Such defines were typically within #if defined(KERNEL) .. #endif
> so non-kld ports shouldn't be referring to them, right?!

I don't know if that is typical, but in this case the point is to make it=

visible to user level.  We don't expect base/ports to do that currently,
but imported programs will.

		Mike