[v2] net: add bit fields to IPv6 header definition
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Commit Message
DPDK IPv6 header definition combined the `version`, `traffic class`
and `flow label` header fields into a single 32 bits structure member
`vtc_flow`.
The patch expands IPv6 header definition with dedicated structure
members for the `version`, `traffic class` and `flow label` fields.
The `traffic class` is also separated into DS and ECN fields.
The patch also preserves existing `vtc_flow` structure member for
backward compatibility.
Signed-off-by: Gregory Etelson <getelson@nvidia.com>
---
v2:
Replace uint32_t with rte_be32_t.
Split traffic_class into DS and ECN bits.
---
lib/net/rte_ip.h | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)
--
2.43.0
Comments
> From: Gregory Etelson [mailto:getelson@nvidia.com]
> Sent: Tuesday, 18 June 2024 09.58
>
> DPDK IPv6 header definition combined the `version`, `traffic class`
> and `flow label` header fields into a single 32 bits structure member
> `vtc_flow`.
>
> The patch expands IPv6 header definition with dedicated structure
> members for the `version`, `traffic class` and `flow label` fields.
> The `traffic class` is also separated into DS and ECN fields.
>
> The patch also preserves existing `vtc_flow` structure member for
> backward compatibility.
>
> Signed-off-by: Gregory Etelson <getelson@nvidia.com>
> ---
> v2:
> Replace uint32_t with rte_be32_t.
> Split traffic_class into DS and ECN bits.
> ---
> lib/net/rte_ip.h | 18 +++++++++++++++++-
> 1 file changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/lib/net/rte_ip.h b/lib/net/rte_ip.h
> index 0d103d4127..fe1d596054 100644
> --- a/lib/net/rte_ip.h
> +++ b/lib/net/rte_ip.h
> @@ -524,7 +524,23 @@ rte_ipv4_udptcp_cksum_mbuf_verify(const struct rte_mbuf
> *m,
> * IPv6 Header
> */
> struct rte_ipv6_hdr {
> - rte_be32_t vtc_flow; /**< IP version, traffic class & flow label.
> */
> + union {
> + rte_be32_t vtc_flow; /**< IP version, traffic class & flow
> label. */
> + __extension__
> + struct {
> +#if RTE_BYTE_ORDER == RTE_LITTLE_ENDIAN
> + rte_be32_t flow_label:20; /**< flow label */
I don't know if sub-unions of bitfields are possible and/or require special magic for packing the bits.
If possible, expanding the 8 bit "tc" field like this would be nice:
+ union {
+ rte_be32_t tc:8;
+ __extension__
+ struct {
> + rte_be32_t ecn:2; /**< ECN */
> + rte_be32_t ds:6; /**< differentiated services */
+ };
+ };
> + rte_be32_t version:4; /**< version */
> +#elif RTE_BYTE_ORDER == RTE_BIG_ENDIAN
> + rte_be32_t version:4; /**< version */
> + rte_be32_t ds:6; /**< differentiated services */
> + rte_be32_t ecn:2; /**< ECN */
> + rte_be32_t flow_label:20; /**< flow label */
> +#endif
> + };
> + };
> rte_be16_t payload_len; /**< IP payload size, including ext. headers
> */
> uint8_t proto; /**< Protocol, next header. */
> uint8_t hop_limits; /**< Hop limits. */
> --
> 2.43.0
Without the suggested addition,
Reviewed-by: Morten Brørup <mb@smartsharesystems.com>
With the suggested addition,
Acked-by: Morten Brørup <mb@smartsharesystems.com>
@@ -524,7 +524,23 @@ rte_ipv4_udptcp_cksum_mbuf_verify(const struct rte_mbuf *m,
* IPv6 Header
*/
struct rte_ipv6_hdr {
- rte_be32_t vtc_flow; /**< IP version, traffic class & flow label. */
+ union {
+ rte_be32_t vtc_flow; /**< IP version, traffic class & flow label. */
+ __extension__
+ struct {
+#if RTE_BYTE_ORDER == RTE_LITTLE_ENDIAN
+ rte_be32_t flow_label:20; /**< flow label */
+ rte_be32_t ecn:2; /**< ECN */
+ rte_be32_t ds:6; /**< differentiated services */
+ rte_be32_t version:4; /**< version */
+#elif RTE_BYTE_ORDER == RTE_BIG_ENDIAN
+ rte_be32_t version:4; /**< version */
+ rte_be32_t ds:6; /**< differentiated services */
+ rte_be32_t ecn:2; /**< ECN */
+ rte_be32_t flow_label:20; /**< flow label */
+#endif
+ };
+ };
rte_be16_t payload_len; /**< IP payload size, including ext. headers */
uint8_t proto; /**< Protocol, next header. */
uint8_t hop_limits; /**< Hop limits. */