| From foo@baz Mon May 16 11:20:33 PDT 2016 |
| From: Eric Dumazet <edumazet@google.com> |
| Date: Mon, 9 May 2016 20:55:16 -0700 |
| Subject: tcp: refresh skb timestamp at retransmit time |
| |
| From: Eric Dumazet <edumazet@google.com> |
| |
| [ Upstream commit 10a81980fc47e64ffac26a073139813d3f697b64 ] |
| |
| In the very unlikely case __tcp_retransmit_skb() can not use the cloning |
| done in tcp_transmit_skb(), we need to refresh skb_mstamp before doing |
| the copy and transmit, otherwise TCP TS val will be an exact copy of |
| original transmit. |
| |
| Fixes: 7faee5c0d514 ("tcp: remove TCP_SKB_CB(skb)->when") |
| Signed-off-by: Eric Dumazet <edumazet@google.com> |
| Cc: Yuchung Cheng <ycheng@google.com> |
| Acked-by: Yuchung Cheng <ycheng@google.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| net/ipv4/tcp_output.c | 6 ++++-- |
| 1 file changed, 4 insertions(+), 2 deletions(-) |
| |
| --- a/net/ipv4/tcp_output.c |
| +++ b/net/ipv4/tcp_output.c |
| @@ -2625,8 +2625,10 @@ int __tcp_retransmit_skb(struct sock *sk |
| */ |
| if (unlikely((NET_IP_ALIGN && ((unsigned long)skb->data & 3)) || |
| skb_headroom(skb) >= 0xFFFF)) { |
| - struct sk_buff *nskb = __pskb_copy(skb, MAX_TCP_HEADER, |
| - GFP_ATOMIC); |
| + struct sk_buff *nskb; |
| + |
| + skb_mstamp_get(&skb->skb_mstamp); |
| + nskb = __pskb_copy(skb, MAX_TCP_HEADER, GFP_ATOMIC); |
| err = nskb ? tcp_transmit_skb(sk, nskb, 0, GFP_ATOMIC) : |
| -ENOBUFS; |
| } else { |
