tcp: add SYN/data info to TCP_INFO
Add a bit TCPI_OPT_SYN_DATA (32) to the socket option TCP_INFO:tcpi_options.
It's set if the data in SYN (sent or received) is acked by SYN-ACK. Server or
client application can use this information to check Fast Open success rate.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 8a7fc4b..60b7aac 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -191,7 +191,8 @@
u8 do_early_retrans:1,/* Enable RFC5827 early-retransmit */
early_retrans_delayed:1, /* Delayed ER timer installed */
syn_data:1, /* SYN includes data */
- syn_fastopen:1; /* SYN includes Fast Open option */
+ syn_fastopen:1, /* SYN includes Fast Open option */
+ syn_data_acked:1;/* data in SYN is acked by SYN-ACK */
/* RTT measurement */
u32 srtt; /* smoothed round trip time << 3 */
diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
index c4b89a5..e962faa 100644
--- a/include/uapi/linux/tcp.h
+++ b/include/uapi/linux/tcp.h
@@ -130,6 +130,7 @@
#define TCPI_OPT_WSCALE 4
#define TCPI_OPT_ECN 8 /* ECN was negociated at TCP session init */
#define TCPI_OPT_ECN_SEEN 16 /* we received at least one packet with ECT */
+#define TCPI_OPT_SYN_DATA 32 /* SYN-ACK acked data in SYN sent or rcvd */
enum tcp_ca_state {
TCP_CA_Open = 0,