ring: netsniff-ng: migrate capture only to TPACKET_V3

Lets migrate capturing to TPACKET_V3, since it will bring a better
performance due to fewer page cache misses caused by a higher density
of packets, since now they are contigous placed in the ring buffer.

It is said that TPACKET_V3 brings the following benefits:

 *) ~15 - 20% reduction in CPU-usage
 *) ~20% increase in packet capture rate
 *) ~2x increase in packet density
 *) Port aggregation analysis
 *) Non static frame size to capture entire packet payload

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/ring.h b/ring.h
index be04cf0..8bfe1eb 100644
--- a/ring.h
+++ b/ring.h
@@ -26,6 +26,13 @@
 #include "built_in.h"
 #include "die.h"
 
+union tpacket_uhdr {
+	struct tpacket_hdr  *h1;
+	struct tpacket2_hdr *h2;
+	struct tpacket3_hdr *h3;
+	void *raw;
+};
+
 struct frame_map {
 	struct tpacket2_hdr tp_h __aligned_tpacket;
 	struct sockaddr_ll s_ll __align_tpacket(sizeof(struct tpacket2_hdr));