tcp: extract code to compute SYNACK RTT
In preparation for adding another spot where we compute the SYNACK
RTT, extract this code so that it can be shared.
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/tcp.h b/include/net/tcp.h
index a8cb00c..a718d0e 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1137,6 +1137,15 @@
ireq->loc_port = tcp_hdr(skb)->dest;
}
+/* Compute time elapsed between SYNACK and the ACK completing 3WHS */
+static inline void tcp_synack_rtt_meas(struct sock *sk,
+ struct request_sock *req)
+{
+ if (tcp_rsk(req)->snt_synack)
+ tcp_valid_rtt_meas(sk,
+ tcp_time_stamp - tcp_rsk(req)->snt_synack);
+}
+
extern void tcp_enter_memory_pressure(struct sock *sk);
static inline int keepalive_intvl_when(const struct tcp_sock *tp)
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index e64abed..1e66f7f 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1733,9 +1733,7 @@
newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
tcp_initialize_rcv_mss(newsk);
- if (tcp_rsk(req)->snt_synack)
- tcp_valid_rtt_meas(newsk,
- tcp_time_stamp - tcp_rsk(req)->snt_synack);
+ tcp_synack_rtt_meas(newsk, req);
newtp->total_retrans = req->retrans;
#ifdef CONFIG_TCP_MD5SIG
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index f3bfb8b..cfeeeb7 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1348,9 +1348,7 @@
newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
tcp_initialize_rcv_mss(newsk);
- if (tcp_rsk(req)->snt_synack)
- tcp_valid_rtt_meas(newsk,
- tcp_time_stamp - tcp_rsk(req)->snt_synack);
+ tcp_synack_rtt_meas(newsk, req);
newtp->total_retrans = req->retrans;
newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;