tcp: consolidate SYNACK RTT sampling
The first patch consolidates SYNACK and other RTT measurement to use a
central function tcp_ack_update_rtt(). A (small) bonus is now SYNACK
RTT measurement happens after PAWS check, potentially reducing the
impact of RTO seeding on bad TCP timestamps values.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index ab1c086..58a3e69 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -411,6 +411,8 @@
newtp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
tcp_enable_early_retrans(newtp);
newtp->tlp_high_seq = 0;
+ newtp->lsndtime = treq->snt_synack;
+ newtp->total_retrans = req->num_retrans;
/* So many TCP implementations out there (incorrectly) count the
* initial SYN frame in their delayed-ACK and congestion control
@@ -666,12 +668,6 @@
if (!(flg & TCP_FLAG_ACK))
return NULL;
- /* Got ACK for our SYNACK, so update baseline for SYNACK RTT sample. */
- if (tmp_opt.saw_tstamp && tmp_opt.rcv_tsecr)
- tcp_rsk(req)->snt_synack = tmp_opt.rcv_tsecr;
- else if (req->num_retrans) /* don't take RTT sample if retrans && ~TS */
- tcp_rsk(req)->snt_synack = 0;
-
/* For Fast Open no more processing is needed (sk is the
* child socket).
*/