tcp: Introduce scatter-gather IO path from socket to tap

...similarly to what was done for UDP. Quick performance test with
32KiB buffers, host to VM:

$ iperf3 -c 192.0.2.2 -N
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  8.47 GBytes  7.27 Gbits/sec    0             sender
[  5]   0.00-10.00  sec  8.45 GBytes  7.26 Gbits/sec                  receiver

$ iperf3 -c 2a01:598:88ba:a056:271f:473a:c0d9:abc1
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  8.43 GBytes  7.24 Gbits/sec    0             sender
[  5]   0.00-10.00  sec  8.41 GBytes  7.22 Gbits/sec                  receiver

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/passt.c b/passt.c
index c01a031..ff850e7 100644
--- a/passt.c
+++ b/passt.c
@@ -441,6 +441,7 @@ static void timer_handler(struct ctx *c, struct timespec *now)
 void proto_update_l2_buf(unsigned char *eth_d, unsigned char *eth_s,
 			 uint32_t *ip_da)
 {
+	tcp_update_l2_buf(eth_d, eth_s, ip_da);
 	udp_update_l2_buf(eth_d, eth_s, ip_da);
 }