Subject: [PATCH net-next 2/8] tcp: accept SOF_TIMESTAMPING_OPT_ID for passive TFO

From: Soheil Hassas Yeganeh <[email-masked]>
Date: Wed, 30 Mar 2016 18:37:22 -0400

From: Soheil Hassas Yeganeh <[email-masked]>

SOF_TIMESTAMPING_OPT_ID is set to get data-independent IDs
to associate timestamps with send calls. For TCP connections,
tp->snd_una is used as the starting point to calculate
relative IDs.

This socket option will fail if set before the handshake on a
passive TCP fast open connection with data in SYN or SYN/ACK,
since setsockopt requires the connection to be in the
ESTABLISHED state.

To address these, instead of limiting the option to the
ESTABLISHED state, accept the SOF_TIMESTAMPING_OPT_ID option as
long as the connection is not in LISTEN or CLOSE states.

Signed-off-by: Soheil Hassas Yeganeh <[email-masked]>
---
 net/core/sock.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/core/sock.c b/net/core/sock.c
index 66976f8..0a64fe2 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -832,7 +832,8 @@ set_rcvbuf:
 		    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
 			if (sk->sk_protocol == IPPROTO_TCP &&
 			    sk->sk_type == SOCK_STREAM) {
-				if (sk->sk_state != TCP_ESTABLISHED) {
+				if ((1 << sk->sk_state) &
+				    (TCPF_CLOSE | TCPF_LISTEN)) {
 					ret = -EINVAL;
 					break;
 				}
-- 
2.8.0.rc3.226.g39d4020