[PATCH dpdk] net: enforce 2-bytes alignment on IPv6 headers

[Morten Brørup]

> From: Robin Jarry [mailto:rjarry at redhat.com]
> Sent: Tuesday, 5 November 2024 13.25
> 
> IPv6 headers are always aligned on a 2-bytes grid. Reflect this in the
> structure definition.
> 
> Signed-off-by: Robin Jarry <rjarry at redhat.com>
> ---
>  lib/net/rte_ip6.h | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/lib/net/rte_ip6.h b/lib/net/rte_ip6.h
> index 3ae38811b27c..fea7d7b0cd73 100644
> --- a/lib/net/rte_ip6.h
> +++ b/lib/net/rte_ip6.h
> @@ -460,7 +460,7 @@ rte_ether_mcast_from_ipv6(struct rte_ether_addr
> *mac, const struct rte_ipv6_addr
>  /**
>   * IPv6 Header
>   */
> -struct rte_ipv6_hdr {
> +struct __rte_aligned(2) rte_ipv6_hdr {
>  	union {
>  		rte_be32_t vtc_flow;        /**< IP version, traffic class
> & flow label. */
>  		__extension__
> @@ -507,7 +507,7 @@ static inline int rte_ipv6_check_version(const
> struct rte_ipv6_hdr *ip)
>  /**
>   * IPv6 Routing Extension Header
>   */
> -struct rte_ipv6_routing_ext {
> +struct __rte_aligned(2) rte_ipv6_routing_ext {
>  	uint8_t next_hdr;			/**< Protocol, next header. */
>  	uint8_t hdr_len;			/**< Header length. */
>  	uint8_t type;				/**< Extension header type.
> */
> @@ -751,7 +751,7 @@ rte_ipv6_udptcp_cksum_mbuf_verify(const struct
> rte_mbuf *m,
>  #define RTE_IPV6_SET_FRAG_DATA(fo, mf)	\
>  	(((fo) & RTE_IPV6_EHDR_FO_MASK) | ((mf) & RTE_IPV6_EHDR_MF_MASK))
> 
> -struct rte_ipv6_fragment_ext {
> +struct __rte_aligned(2) rte_ipv6_fragment_ext {
>  	uint8_t next_header;	/**< Next header type */
>  	uint8_t reserved;	/**< Reserved */
>  	rte_be16_t frag_data;	/**< All fragmentation data */
> --
> 2.47.0

Reviewed-by: Morten Brørup <mb at smartsharesystems.com>