tcp: introduce tcp_skb_timestamp_us() helper
There are few places where TCP reads skb->skb_mstamp expecting
a value in usec unit.
skb->tstamp (aka skb->skb_mstamp) will soon store CLOCK_TAI nsec value.
Add tcp_skb_timestamp_us() to provide proper conversion when needed.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 09547ef..1f2496e 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -544,7 +544,7 @@ void tcp_v4_err(struct sk_buff *icmp_skb, u32 info)
BUG_ON(!skb);
tcp_mstamp_refresh(tp);
- delta_us = (u32)(tp->tcp_mstamp - skb->skb_mstamp);
+ delta_us = (u32)(tp->tcp_mstamp - tcp_skb_timestamp_us(skb));
remaining = icsk->icsk_rto -
usecs_to_jiffies(delta_us);