On Thu, May 25, 2017 at 6:24 AM, Or Gerlitz <ogerl...@mellanox.com> wrote:
> Add support for dissection of ip tos and ttl and ipv6 traffic-class
> and hoplimit. Both are dissected into the same struct.
>
> Uses similar call to ip dissection function as with tcp, arp and others.
>
> Signed-off-by: Or Gerlitz <ogerl...@mellanox.com>
> Reviewed-by: Jiri Pirko <j...@mellanox.com>
> ---
> include/net/flow_dissector.h | 11 +++++++++++
> net/core/flow_dissector.c | 40 ++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 51 insertions(+)
>
> diff --git a/include/net/flow_dissector.h b/include/net/flow_dissector.h
> index efe34eec..e2663e9 100644
> --- a/include/net/flow_dissector.h
> +++ b/include/net/flow_dissector.h
> @@ -165,6 +165,16 @@ struct flow_dissector_key_tcp {
> __be16 flags;
> };
>
> +/**
> + * struct flow_dissector_key_ip:
> + * @tos: tos
> + * @ttl: ttl
> + */
> +struct flow_dissector_key_ip {
> + __u8 tos;
> + __u8 ttl;
> +};
> +
Looks like yet more complexity be piled onto flow dissector. Instead
of splitting out individual fields can we just return a pointer to the
IP header and let the caller extract the fields they're interested in?
Tom
> enum flow_dissector_key_id {
> FLOW_DISSECTOR_KEY_CONTROL, /* struct flow_dissector_key_control */
> FLOW_DISSECTOR_KEY_BASIC, /* struct flow_dissector_key_basic */
> @@ -186,6 +196,7 @@ enum flow_dissector_key_id {
> FLOW_DISSECTOR_KEY_ENC_PORTS, /* struct flow_dissector_key_ports */
> FLOW_DISSECTOR_KEY_MPLS, /* struct flow_dissector_key_mpls */
> FLOW_DISSECTOR_KEY_TCP, /* struct flow_dissector_key_tcp */
> + FLOW_DISSECTOR_KEY_IP, /* struct flow_dissector_key_ip */
>
> FLOW_DISSECTOR_KEY_MAX,
> };
> diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
> index 5a45943..fc5fc45 100644
> --- a/net/core/flow_dissector.c
> +++ b/net/core/flow_dissector.c
> @@ -367,6 +367,40 @@ __skb_flow_dissect_tcp(const struct sk_buff *skb,
> key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF));
> }
>
> +static void
> +__skb_flow_dissect_ipv4(const struct sk_buff *skb,
> + struct flow_dissector *flow_dissector,
> + void *target_container, void *data, const struct
> iphdr *iph)
> +{
> + struct flow_dissector_key_ip *key_ip;
> +
> + if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
> + return;
> +
> + key_ip = skb_flow_dissector_target(flow_dissector,
> + FLOW_DISSECTOR_KEY_IP,
> + target_container);
> + key_ip->tos = iph->tos;
> + key_ip->ttl = iph->ttl;
> +}
> +
> +static void
> +__skb_flow_dissect_ipv6(const struct sk_buff *skb,
> + struct flow_dissector *flow_dissector,
> + void *target_container, void *data, const struct
> ipv6hdr *iph)
> +{
> + struct flow_dissector_key_ip *key_ip;
> +
> + if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
> + return;
> +
> + key_ip = skb_flow_dissector_target(flow_dissector,
> + FLOW_DISSECTOR_KEY_IP,
> + target_container);
> + key_ip->tos = ipv6_get_dsfield(iph);
> + key_ip->ttl = iph->hop_limit;
> +}
> +
> /**
> * __skb_flow_dissect - extract the flow_keys struct and return it
> * @skb: sk_buff to extract the flow from, can be NULL if the rest are
> specified
> @@ -469,6 +503,9 @@ bool __skb_flow_dissect(const struct sk_buff *skb,
> }
> }
>
> + __skb_flow_dissect_ipv4(skb, flow_dissector,
> + target_container, data, iph);
> +
> if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
> goto out_good;
>
> @@ -514,6 +551,9 @@ bool __skb_flow_dissect(const struct sk_buff *skb,
> goto out_good;
> }
>
> + __skb_flow_dissect_ipv6(skb, flow_dissector,
> + target_container, data, iph);
> +
> if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
> goto out_good;
>
> --
> 2.3.7
>
