tcp: allow segment with FIN in tcp_try_coalesce()

We can allow a segment with FIN to be aggregated,
if we take care to add tcp flags,
and if skb_try_coalesce() takes care of zero sized skbs.

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

1 files changed, 1 insertions, 3 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 8f639a4face9..228bf0c5ff19 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4143,9 +4143,6 @@ static bool tcp_try_coalesce(struct sock *sk,
 
         *fragstolen = false;
 
-        if (tcp_hdr(from)->fin)
-                return false;
-
         /* Its possible this segment overlaps with prior segment in queue */
         if (TCP_SKB_CB(from)->seq != TCP_SKB_CB(to)->end_seq)
                 return false;
@@ -4158,6 +4155,7 @@ static bool tcp_try_coalesce(struct sock *sk,
         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPRCVCOALESCE);
         TCP_SKB_CB(to)->end_seq = TCP_SKB_CB(from)->end_seq;
         TCP_SKB_CB(to)->ack_seq = TCP_SKB_CB(from)->ack_seq;
+        TCP_SKB_CB(to)->tcp_flags |= TCP_SKB_CB(from)->tcp_flags;
         return true;
 }