On Mon, Oct 21, 2019 at 10:09:46PM +0200, Matteo Croce wrote:
> FLOW_DISSECTOR_KEY_ICMP is checked for every packet, not only ICMP ones.
> Even if the test overhead is probably negligible, move the
> ICMP dissector code under the big 'switch(ip_proto)' so it gets called
> only for ICMP packets.
>
> Signed-off-by: Matteo Croce <mcr...@redhat.com>
Reviewed-by: Simon Horman <simon.hor...@netronome.com>
> ---
> net/core/flow_dissector.c | 34 +++++++++++++++++++++++++---------
> 1 file changed, 25 insertions(+), 9 deletions(-)
>
> diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
> index affde70dad47..6443fac65ce8 100644
> --- a/net/core/flow_dissector.c
> +++ b/net/core/flow_dissector.c
> @@ -203,6 +203,25 @@ __be32 __skb_flow_get_ports(const struct sk_buff *skb,
> int thoff, u8 ip_proto,
> }
> EXPORT_SYMBOL(__skb_flow_get_ports);
>
> +/* If FLOW_DISSECTOR_KEY_ICMP is set, get the Type and Code from an ICMP
> packet
> + * using skb_flow_get_be16().
> + */
> +static void __skb_flow_dissect_icmp(const struct sk_buff *skb,
> + struct flow_dissector *flow_dissector,
> + void *target_container,
> + void *data, int thoff, int hlen)
> +{
> + struct flow_dissector_key_icmp *key_icmp;
> +
> + if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ICMP))
> + return;
> +
> + key_icmp = skb_flow_dissector_target(flow_dissector,
> + FLOW_DISSECTOR_KEY_ICMP,
> + target_container);
> + key_icmp->icmp = skb_flow_get_be16(skb, thoff, data, hlen);
> +}
> +
> void skb_flow_dissect_meta(const struct sk_buff *skb,
> struct flow_dissector *flow_dissector,
> void *target_container)
> @@ -853,7 +872,6 @@ bool __skb_flow_dissect(const struct net *net,
> struct flow_dissector_key_basic *key_basic;
> struct flow_dissector_key_addrs *key_addrs;
> struct flow_dissector_key_ports *key_ports;
> - struct flow_dissector_key_icmp *key_icmp;
> struct flow_dissector_key_tags *key_tags;
> struct flow_dissector_key_vlan *key_vlan;
> struct bpf_prog *attached = NULL;
> @@ -1295,6 +1313,12 @@ bool __skb_flow_dissect(const struct net *net,
> data, nhoff, hlen);
> break;
>
> + case IPPROTO_ICMP:
> + case IPPROTO_ICMPV6:
> + __skb_flow_dissect_icmp(skb, flow_dissector, target_container,
> + data, nhoff, hlen);
> + break;
> +
> default:
> break;
> }
> @@ -1308,14 +1332,6 @@ bool __skb_flow_dissect(const struct net *net,
> data, hlen);
> }
>
> - if (dissector_uses_key(flow_dissector,
> - FLOW_DISSECTOR_KEY_ICMP)) {
> - key_icmp = skb_flow_dissector_target(flow_dissector,
> - FLOW_DISSECTOR_KEY_ICMP,
> - target_container);
> - key_icmp->icmp = skb_flow_get_be16(skb, nhoff, data, hlen);
> - }
> -
> /* Process result of IP proto processing */
> switch (fdret) {
> case FLOW_DISSECT_RET_PROTO_AGAIN:
> --
> 2.21.0
>
