[net-next,2/4] flow_dissector: skip the ICMP dissector for non ICMP packets
diff mbox series

Message ID 20191021200948.23775-3-mcroce@redhat.com
State Changes Requested
Delegated to: David Miller
Headers show
Series
  • ICMP flow improvements
Related show

Commit Message

Matteo Croce Oct. 21, 2019, 8:09 p.m. UTC
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 <mcroce@redhat.com>
---
 net/core/flow_dissector.c | 34 +++++++++++++++++++++++++---------
 1 file changed, 25 insertions(+), 9 deletions(-)

Comments

Simon Horman Oct. 23, 2019, 9:57 a.m. UTC | #1
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 <mcroce@redhat.com>

Reviewed-by: Simon Horman <simon.horman@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
>

Patch
diff mbox series

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: