+to: Various CPU architecture maintainers +to: Stephen (already participating in this discussion) +cc: x86 CPU architecture maintainers
> From: Robin Jarry [mailto:rja...@redhat.com] > Sent: Tuesday, 1 October 2024 10.17 > > There is currently no structure defined for IPv6 addresses. Introduce > one that is simply a uint8_t array of 16 elements without any union. > The > idea is to ensure this structure alignment is 1 so that it can be > mapped > directly on unaligned packet memory. > > Signed-off-by: Robin Jarry <rja...@redhat.com> > --- > lib/net/rte_ip6.h | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/lib/net/rte_ip6.h b/lib/net/rte_ip6.h > index 5ad1dd25db08..52c41088681e 100644 > --- a/lib/net/rte_ip6.h > +++ b/lib/net/rte_ip6.h > @@ -35,6 +35,16 @@ > extern "C" { > #endif > > +#define RTE_IPV6_ADDR_SIZE 16 > +#define RTE_IPV6_MAX_DEPTH 128 > + > +/** > + * IPv6 Address > + */ > +struct rte_ipv6_addr { > + unsigned char a[RTE_IPV6_ADDR_SIZE]; > +}; This has been discussed before, but I want to double check... If - sometime in the future - we want to add a union to offer a 2-byte access variant and make the structure to 2-byte aligned (which is the common case in Ethernet packets), it will break both API and ABI. This seems unlikely to get accepted at a later time, so I think we are - right now - in a situation where it's now or never: struct rte_ipv6_addr { __extension__ union { unsigned char a[RTE_IPV6_ADDR_SIZE]; uint16_t w[RTE_IPV6_ADDR_SIZE / 2]; }; }; Unless some of the CPU folks want the 2-byte aligned variant, stick with what you offered.
