3:29 p.m.
On 09/16/2010 04:52 AM, Bruno Haible wrote:
<snip>
This message talks about the unportability of a field
's6_addr32' in
'struct in6_addr'. Sure this is unportable: POSIX [1] specifies only the
presence of 's6_addr'.
I don't see why gnulib should support this: An application can perfectly
access the 16 bytes of the s6_addr[] array. Why would it need to access a
specific part of it in a special way?
My apologies. I should have been significantly clearer in what I was
trying for there. :)
(adding the libvirt devel mailing list back in, due to relevance)
Tried compiling libvirt on OS X, which errored on this piece of IPv6 code:
http://www.redhat.com/archives/libvir-list/2010-September/msg00243.html
The message I quoted to Eric above, which you've then looked at, was
danpb wondering whether we should be using gnulib to avoid the
portability problem.
This stuff is outside my area of expertise though. :)
Regards and best wishes,
Justin Clift
3:32 p.m.
New subject: [libvirt] IPv6 structs on MacOS X
On 09/15/2010 02:29 PM, Justin Clift wrote:
On 09/16/2010 04:52 AM, Bruno Haible wrote:
<snip>
> This message talks about the unportability of a field 's6_addr32' in
> 'struct in6_addr'. Sure this is unportable: POSIX [1] specifies only the
> presence of 's6_addr'.
>
> I don't see why gnulib should support this: An application can perfectly
> access the 16 bytes of the s6_addr[] array. Why would it need to access a
> specific part of it in a special way?
My apologies. I should have been significantly clearer in what I was
trying for there. :)
(adding the libvirt devel mailing list back in, due to relevance)
Tried compiling libvirt on OS X, which errored on this piece of IPv6 code:
http://www.redhat.com/archives/libvir-list/2010-September/msg00243.html
The message I quoted to Eric above, which you've then looked at, was
danpb wondering whether we should be using gnulib to avoid the
portability problem.
I agree with Bruno - the portability problem stems from using a field
member not specified by POSIX in the first place. It should be
sufficiently easy to rewrite the offending libvirt code to use only the
portable interfaces, without burdening gnulib with the effort of
supporting multi-byte alias names for the same data.
--
Eric Blake eblake(a)redhat.com +1-801-349-2682
Libvirt virtualization library http://libvirt.org
3:35 p.m.
New subject: [libvirt] IPv6 structs on MacOS X
On 09/16/2010 06:32 AM, Eric Blake wrote:
<snip>
I agree with Bruno - the portability problem stems from using a
field
member not specified by POSIX in the first place. It should be
sufficiently easy to rewrite the offending libvirt code to use only the
portable interfaces, without burdening gnulib with the effort of
supporting multi-byte alias names for the same data.
Cool, got it. Thanks guys. :)
3:52 p.m.
New subject: [libvirt] [PATCH] build: avoid non-portable IPv6 struct member, for MacOS X
* src/util/network.c (getIPv6Addr): Manually join s6_addr bytes,
instead of assuming s6_addr16 shorts.
Reported by Justin Clifton; solution suggested by Bruno Haible.
---
Like this. Tested on Fedora, not MacOS X; but since getting it wrong
_does_ fail the testsuite, I'm confident it works (spoken as one who
swapped the in6_addr[2*i] and in6_addr[2*i+1] bytes on my first attempt).
src/util/network.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/src/util/network.c b/src/util/network.c
index b17d419..17aa746 100644
--- a/src/util/network.c
+++ b/src/util/network.c
@@ -47,7 +47,8 @@ static int getIPv6Addr(virSocketAddrPtr addr, virIPv6AddrPtr tab) {
return(-1);
for (i = 0;i < 8;i++) {
- (*tab)[i] = ntohs(addr->inet6.sin6_addr.s6_addr16[i]);
+ (*tab)[i] = ((addr->inet6.sin6_addr.s6_addr[2 * i] << 8) |
+ addr->inet6.sin6_addr.s6_addr[2 * i + 1]);
}
return(0);
--
1.7.2.3
4 p.m.
New subject: [libvirt] [PATCH] build: avoid non-portable IPv6 struct member, for MacOS X
On 09/16/2010 06:52 AM, Eric Blake wrote:
* src/util/network.c (getIPv6Addr): Manually join s6_addr bytes,
instead of assuming s6_addr16 shorts.
Reported by Justin Clifton; solution suggested by Bruno Haible.
---
Like this. Tested on Fedora, not MacOS X; but since getting it wrong
_does_ fail the testsuite, I'm confident it works (spoken as one who
swapped the in6_addr[2*i] and in6_addr[2*i+1] bytes on my first attempt).
ACK. Compiles fine on OSX now. :)
4:03 p.m.
New subject: [libvirt] [PATCH] build: avoid non-portable IPv6 struct member, for MacOS X
On 09/15/2010 03:00 PM, Justin Clift wrote:
On 09/16/2010 06:52 AM, Eric Blake wrote:
> * src/util/network.c (getIPv6Addr): Manually join s6_addr bytes,
> instead of assuming s6_addr16 shorts.
> Reported by Justin Clifton; solution suggested by Bruno Haible.
> ---
>
> Like this. Tested on Fedora, not MacOS X; but since getting it wrong
> _does_ fail the testsuite, I'm confident it works (spoken as one who
> swapped the in6_addr[2*i] and in6_addr[2*i+1] bytes on my first attempt).
ACK. Compiles fine on OSX now. :)
Thanks; pushed.
--
Eric Blake eblake(a)redhat.com +1-801-349-2682
Libvirt virtualization library http://libvirt.org
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