net: flow_dissector: add support for dissection of tcp flags

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>
Acked-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jiri Pirko 2017-05-23 18:40:44 +02:00 committed by David S. Miller
parent 2a7f38c538
commit ac4bb5de27
2 changed files with 38 additions and 0 deletions

View File

@ -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,
};

View File

@ -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 +708,10 @@ ip_proto_again:
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);
break;
default:
break;
}