[Nut-upsdev] Re: [nut-commits] svn commit r714 - in trunk: . server

[Arjen de Korte]

> OK, I have removed the autoconf test for s6_addr32 (which is no longer
> used), and wrote a new test for IN6_IS_ADDR_V4MAPPED. The latter is
> probably portable, but since we're already in the business of testing,
> it does not hurt to do so.

The macro is defined in RFC 2553 (and notably, AI_ADDRCONFIG too), so I
think it should be portable. But until we're absolutely sure it is,
testing for it is probably the right thing to do.

> Arjen, I wonder about server/access.c, line 60-61:
>
>        return (IN6_IS_ADDR_V4MAPPED(ip6) &&
>           ((((const u_int32_t *)ip6)[3] & (u_int32_t)prefix) ==
> net->s_addr));
>
> Comparing this with line 38:
>
>       return((((struct sockaddr_in*)ip_addr)->sin_addr.s_addr &
> htonl(prefix)) == ((struct sockaddr_in*)net_addr)->sin_addr.s_addr);
>
> I wonder if it shouldn't be htonl(prefix) in line 61, or perhaps
> ntohl(net->s_addr) in line 61. I don't understand these data
> structures well, and presumably the patch came from someone who tested
> it on a little-endian machine, but it seems to me from inet(3) that:
>
> *.s_addr                          is in network byte order,
> ((const u_int32_t *)ip6)[3]       is in network byte order (???)
> prefix                            is in host byte order.
>
> I cannot find the man page for struct in6_addr, so I am not sure about
> the byte order of ip6, but it seems that if it's a byte array
> converted to a int32 array, it should be big-endian.

You could be right, I didn't look at this. And neither did I for most
other things that were introduced with the IPv6 patch. I only have a
little endian machine available for testing, so trying this out is not an
option. All this juggling with casting data from one type to the the other
made my head spin after a couple of hours. :-)

For me, the IPv6 patch seems to do what it needs to do, but it would be
really useful to try this out on a big endian machine too.

Best regards, Arjen
-- 
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