[PATCH V4 net-next 2/3] tcp: Add tcp_retransmit_stamp() helper routine

From: Jon Maxwell
Date: Wed Jul 18 2018 - 21:15:45 EST


Create a seperate helper routine as per Neal Cardwells suggestion. To
be used by the final commit in this series and retransmits_timed_out().

Signed-off-by: Jon Maxwell <jmaxwell37@xxxxxxxxx>
---
net/ipv4/tcp_timer.c | 25 +++++++++++++++++--------
1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index fa34984d0b12..d212f183dd2d 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -22,6 +22,20 @@
#include <linux/gfp.h>
#include <net/tcp.h>

+u32 tcp_retransmit_stamp(const struct sock *sk)
+{
+ u32 start_ts = tcp_sk(sk)->retrans_stamp;
+
+ if (unlikely(!start_ts)) {
+ struct sk_buff *head = tcp_rtx_queue_head(sk);
+
+ if (!head)
+ return 0;
+ start_ts = tcp_skb_timestamp(head);
+ }
+ return start_ts;
+}
+
/**
* tcp_write_err() - close socket and save error info
* @sk: The socket the error has appeared on.
@@ -166,14 +180,9 @@ static bool retransmits_timed_out(struct sock *sk,
if (!inet_csk(sk)->icsk_retransmits)
return false;

- start_ts = tcp_sk(sk)->retrans_stamp;
- if (unlikely(!start_ts)) {
- struct sk_buff *head = tcp_rtx_queue_head(sk);
-
- if (!head)
- return false;
- start_ts = tcp_skb_timestamp(head);
- }
+ start_ts = tcp_retransmit_stamp(sk);
+ if (!start_ts)
+ return false;

if (likely(timeout == 0)) {
linear_backoff_thresh = ilog2(TCP_RTO_MAX/rto_base);
--
2.13.6