[ovs-dev] [PATCH v5 3/4] lib/flow: Add IPv6 support for flow_compose().

[Ben Pfaff]

On Fri, Dec 06, 2013 at 12:54:40PM -0800, Jarno Rajahalme wrote:
> I had forgot the line in there, was testing for alignment just for
> my own understanding. flow_compose() would be little simpler if we
> had the 32-bit aligned header definitions available. I felt hesitant
> about using the Linux definitions, as they might not be portable to
> other systems.

Do you mean, e.g., "struct ip6_hdr"?  That is portable to at least
BSD, although it is not in POSIX.  Until OVS 1.9.3, we used it without
user complaints, so it is probably OK to use it in flow_compose().
But I like how ovs_16aligned_ip6_hdr is safe even if we make a small
alignment error, so I am not sure that it is worth changing the code
now that it is written.