tcp: Add connection union type

Currently, the tables for spliced and non-spliced connections are entirely
separate, with different types in different arrays.  We want to unify them.
As a first step, create a union type which can represent either a spliced
or non-spliced connection.  For them to be distinguishable, the individual
types need to have a common header added, with a bit indicating which type
this structure is.

This comes at the cost of increasing the size of tcp_tap_conn to over one
(64 byte) cacheline.  This isn't ideal, but it makes things simpler for now
and we'll re-optimize this later.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/tcp_splice.c b/tcp_splice.c
index cbfab01..d8be91b 100644
--- a/tcp_splice.c
+++ b/tcp_splice.c
@@ -46,6 +46,7 @@
 #include <sys/epoll.h>
 #include <sys/types.h>
 #include <sys/socket.h>
+#include <assert.h>
 
 #include "util.h"
 #include "passt.h"
@@ -554,6 +555,7 @@ void tcp_sock_handler_splice(struct ctx *c, union epoll_ref ref,
 		}
 
 		conn = CONN(c->tcp.splice_conn_count++);
+		conn->c.spliced = true;
 		conn->a = s;
 		conn->flags = ref.r.p.tcp.tcp.v6 ? SPLICE_V6 : 0;