diff mbox

[net-next,2/5] net: flow_dissector: add support for dissection of tcp flags

Message ID 20170523143110.5006-3-jiri@resnulli.us
State Superseded, archived
Delegated to: David Miller
Headers show

Commit Message

Jiri Pirko May 23, 2017, 2:31 p.m. UTC 
From: Jiri Pirko <jiri@mellanox.com>

Add support for dissection of tcp flags. Uses similar function call to
tcp dissection function as arp, mpls and others.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
---
 include/net/flow_dissector.h |  9 +++++++++
 net/core/flow_dissector.c    | 31 +++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+)

Comments

Or Gerlitz May 23, 2017, 3:18 p.m. UTC | #1 
On 5/23/2017 5:31 PM, Jiri Pirko wrote:
> @@ -683,6 +708,12 @@ bool __skb_flow_dissect(const struct sk_buff *skb,
>   	case IPPROTO_MPLS:
>   		proto = htons(ETH_P_MPLS_UC);
>   		goto mpls;
> +	case IPPROTO_TCP:
> +		__skb_flow_dissect_tcp(skb, flow_dissector, target_container,
> +				       data, nhoff, hlen);
> +		/* Regardless of the return value, continue to process TCP
> +		 * ports dissection below.
> +		 */

the comment here is a bit misleading, since __skb_flow_dissect_tcp is void

other-wise

Acked-by: Or Gerlitz <ogerlitz@mellanox.com>
Jiri Pirko May 23, 2017, 3:22 p.m. UTC | #2 
Tue, May 23, 2017 at 05:18:33PM CEST, ogerlitz@mellanox.com wrote:
>On 5/23/2017 5:31 PM, Jiri Pirko wrote:
>> @@ -683,6 +708,12 @@ bool __skb_flow_dissect(const struct sk_buff *skb,
>>   	case IPPROTO_MPLS:
>>   		proto = htons(ETH_P_MPLS_UC);
>>   		goto mpls;
>> +	case IPPROTO_TCP:
>> +		__skb_flow_dissect_tcp(skb, flow_dissector, target_container,
>> +				       data, nhoff, hlen);
>> +		/* Regardless of the return value, continue to process TCP
>> +		 * ports dissection below.
>> +		 */
>
>the comment here is a bit misleading, since __skb_flow_dissect_tcp is void


Fixed for v2

>
>other-wise
>
>Acked-by: Or Gerlitz <ogerlitz@mellanox.com>

Thanks
diff mbox

Patch

diff --git a/include/net/flow_dissector.h b/include/net/flow_dissector.h
index 8d21d44..efe34eec 100644
--- a/include/net/flow_dissector.h
+++ b/include/net/flow_dissector.h
@@ -157,6 +157,14 @@  struct flow_dissector_key_eth_addrs {
 	unsigned char src[ETH_ALEN];
 };
 
+/**
+ * struct flow_dissector_key_tcp:
+ * @flags: flags
+ */
+struct flow_dissector_key_tcp {
+	__be16 flags;
+};
+
 enum flow_dissector_key_id {
 	FLOW_DISSECTOR_KEY_CONTROL, /* struct flow_dissector_key_control */
 	FLOW_DISSECTOR_KEY_BASIC, /* struct flow_dissector_key_basic */
@@ -177,6 +185,7 @@  enum flow_dissector_key_id {
 	FLOW_DISSECTOR_KEY_ENC_CONTROL, /* struct flow_dissector_key_control */
 	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_MAX,
 };
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 28d94bc..3fb3388 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -18,6 +18,7 @@ 
 #include <linux/stddef.h>
 #include <linux/if_ether.h>
 #include <linux/mpls.h>
+#include <linux/tcp.h>
 #include <net/flow_dissector.h>
 #include <scsi/fc/fc_fcoe.h>
 
@@ -342,6 +343,30 @@  __skb_flow_dissect_gre(const struct sk_buff *skb,
 	return FLOW_DISSECT_RET_OUT_PROTO_AGAIN;
 }
 
+static void
+__skb_flow_dissect_tcp(const struct sk_buff *skb,
+		       struct flow_dissector *flow_dissector,
+		       void *target_container, void *data, int thoff, int hlen)
+{
+	struct flow_dissector_key_tcp *key_tcp;
+	struct tcphdr *th, _th;
+
+	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP))
+		return;
+
+	th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th);
+	if (!th)
+		return;
+
+	if (unlikely(__tcp_hdrlen(th) < sizeof(_th)))
+		return;
+
+	key_tcp = skb_flow_dissector_target(flow_dissector,
+					    FLOW_DISSECTOR_KEY_TCP,
+					    target_container);
+	key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF));
+}
+
 /**
  * __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
@@ -683,6 +708,12 @@  bool __skb_flow_dissect(const struct sk_buff *skb,
 	case IPPROTO_MPLS:
 		proto = htons(ETH_P_MPLS_UC);
 		goto mpls;
+	case IPPROTO_TCP:
+		__skb_flow_dissect_tcp(skb, flow_dissector, target_container,
+				       data, nhoff, hlen);
+		/* Regardless of the return value, continue to process TCP
+		 * ports dissection below.
+		 */
 	default:
 		break;
 	}