releases/2.6.20.2/fix-tcp-fin-handling.patch

   1 From stable-bounces@linux.kernel.org Tue Feb  6 21:58:49 2007
   2 From: John Heffner <jheffner@psc.edu>
   3 Date: Tue, 06 Feb 2007 21:57:34 -0800 (PST)
   4 Subject: Fix TCP FIN handling
   5 To: stable@kernel.org
   6 Cc: bunk@stusta.de
   7 Message-ID: <20070206.215734.83621142.davem@davemloft.net>
   8
   9 From: John Heffner <jheffner@psc.edu>
  10
  11 We can accidently spit out a huge burst of packets with TSO
  12 when the FIN back is piggybacked onto the final packet.
  13
  14 [TCP]: Don't apply FIN exception to full TSO segments.
  15
  16 Signed-off-by: John Heffner <jheffner@psc.edu>
  17 Signed-off-by: David S. Miller <davem@davemloft.net>
  18 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  19
  20 ---
  21  net/ipv4/tcp_output.c |    3 ++-
  22  1 file changed, 2 insertions(+), 1 deletion(-)
  23
  24 --- linux-2.6.20.1.orig/net/ipv4/tcp_output.c
  25 +++ linux-2.6.20.1/net/ipv4/tcp_output.c
  26 @@ -965,7 +965,8 @@ static inline unsigned int tcp_cwnd_test
  27         u32 in_flight, cwnd;
  28
  29         /* Don't be strict about the congestion window for the final FIN.  */
  30 -       if (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN)
  31 +       if ((TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN) &&
  32 +           tcp_skb_pcount(skb) == 1)
  33                 return 1;
  34
  35         in_flight = tcp_packets_in_flight(tp);