tcp: replace tcp_time_stamp_raw()

In preparation of usec TCP TS support, remove tcp_time_stamp_raw()
in favor of tcp_clock_ts() helper. This helper will return a suitable
32bit result to feed TS values, depending on a socket field.

Also add tcp_tw_tsval() and tcp_rsk_tsval() helpers to factorize
the details.

We do not yet support usec timestamps.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 19 insertions, 6 deletions

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 3bdf1141f5a2..0534526a535d 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -803,6 +803,16 @@ static inline u64 tcp_clock_ms(void)
 	return div_u64(tcp_clock_ns(), NSEC_PER_MSEC);
 }
 
+/* TCP Timestamp included in TS option (RFC 1323) can either use ms
+ * or usec resolution. Each socket carries a flag to select one or other
+ * resolution, as the route attribute could change anytime.
+ * Each flow must stick to initial resolution.
+ */
+static inline u32 tcp_clock_ts(bool usec_ts)
+{
+	return usec_ts ? tcp_clock_us() : tcp_clock_ms();
+}
+
 /* This should only be used in contexts where tp->tcp_mstamp is up to date */
 static inline u32 tcp_time_stamp(const struct tcp_sock *tp)
 {
@@ -820,12 +830,6 @@ static inline u64 tcp_ns_to_ts(u64 ns)
 	return div_u64(ns, NSEC_PER_SEC / TCP_TS_HZ);
 }
 
-/* Could use tcp_clock_us() / 1000, but this version uses a single divide */
-static inline u32 tcp_time_stamp_raw(void)
-{
-	return tcp_ns_to_ts(tcp_clock_ns());
-}
-
 void tcp_mstamp_refresh(struct tcp_sock *tp);
 
 static inline u32 tcp_stamp_us_delta(u64 t1, u64 t0)
@@ -844,6 +848,15 @@ static inline u64 tcp_skb_timestamp_us(const struct sk_buff *skb)
 	return div_u64(skb->skb_mstamp_ns, NSEC_PER_USEC);
 }
 
+static inline u32 tcp_tw_tsval(const struct tcp_timewait_sock *tcptw)
+{
+	return tcp_clock_ts(false) + tcptw->tw_ts_offset;
+}
+
+static inline u32 tcp_rsk_tsval(const struct tcp_request_sock *treq)
+{
+	return tcp_clock_ts(false) + treq->ts_off;
+}
 
 #define tcp_flag_byte(th) (((u_int8_t *)th)[13])