On Thu, 2015-05-28 at 11:19 -0700, Tom Herbert wrote:
> In flow_dissector set the flow label in flow_keys for IPv6. This also
> removes the shortcircuiting of flow dissection when a non-zero label
> is present, the flow label can be considered to provide additional
> entropy for a hash.
>
> Signed-off-by: Tom Herbert <[email protected]>
> ---
> include/net/flow_dissector.h | 4 +++-
> net/core/flow_dissector.c | 31 +++++++++++--------------------
> 2 files changed, 14 insertions(+), 21 deletions(-)
>
> diff --git a/include/net/flow_dissector.h b/include/net/flow_dissector.h
> index 08480fb..14d8483 100644
> --- a/include/net/flow_dissector.h
> +++ b/include/net/flow_dissector.h
> @@ -28,7 +28,8 @@ struct flow_dissector_key_basic {
> };
>
> struct flow_dissector_key_tags {
> - u32 vlan_id:12;
> + u32 vlan_id:12,
> + flow_label:20;
> };
>
> /**
> @@ -111,6 +112,7 @@ enum flow_dissector_key_id {
> FLOW_DISSECTOR_KEY_ETH_ADDRS, /* struct flow_dissector_key_eth_addrs */
> FLOW_DISSECTOR_KEY_TIPC_ADDRS, /* struct flow_dissector_key_tipc_addrs
> */
> FLOW_DISSECTOR_KEY_VLANID, /* struct flow_dissector_key_flow_tags */
> + FLOW_DISSECTOR_KEY_FLOW_LABEL, /* struct flow_dissector_key_flow_tags */
>
> FLOW_DISSECTOR_KEY_MAX,
> };
> diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
> index 5c66cb2..ba089d9 100644
> --- a/net/core/flow_dissector.c
> +++ b/net/core/flow_dissector.c
> @@ -190,7 +190,7 @@ ip:
> case htons(ETH_P_IPV6): {
> const struct ipv6hdr *iph;
> struct ipv6hdr _iph;
> - __be32 flow_label;
> + u32 flow_label;
You change flow_label from __be32 to u32.
>
> ipv6:
> iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data,
> hlen, &_iph);
> @@ -210,30 +210,17 @@ ipv6:
>
> memcpy(key_ipv6_addrs, &iph->saddr,
> sizeof(*key_ipv6_addrs));
> key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
> - goto flow_label;
> }
> - break;
> -flow_label:
> +
> flow_label = ip6_flowlabel(iph);
But ip6_flowlabel() returns a __be32. This should not please sparse.
> if (flow_label) {
> - /* Awesome, IPv6 packet has a flow label so we can
> - * use that to represent the ports without any
> - * further dissection.
> - */
> -
> - key_basic->n_proto = proto;
> - key_basic->ip_proto = ip_proto;
> - key_control->thoff = (u16)nhoff;
> -
> if (skb_flow_dissector_uses_key(flow_dissector,
> -
> FLOW_DISSECTOR_KEY_PORTS)) {
> - key_ports =
> skb_flow_dissector_target(flow_dissector,
> -
> FLOW_DISSECTOR_KEY_PORTS,
> -
> target_container);
> - key_ports->ports = flow_label;
> + FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
> + key_tags =
> skb_flow_dissector_target(flow_dissector,
> +
> FLOW_DISSECTOR_KEY_FLOW_LABEL,
> +
> target_container);
> + key_tags->flow_label = ntohl(flow_label);
Then you call ntohl() on u32 variable. This should also complain.
Have you run sparse ?
make C=2 CF=-D__CHECK_ENDIAN__ net/core/flow_dissector.o
Thanks.
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