[TCP]: fix congestion window update when using TSO deferal

[mirror_ubuntu-bionic-kernel.git] / include / net / tcp.h

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 96cc3b434e40f7f3e68ccd1f6b06a5c564736777..15bdbc6bd571cbeec4de4b6c077df222461d71cb 100644 (file)
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -810,6 +810,27 @@ static __inline__ __u32 tcp_max_burst(const struct tcp_sock *tp)
        return 3;
 }
 
+/* RFC2861 Check whether we are limited by application or congestion window
+ * This is the inverse of cwnd check in tcp_tso_should_defer
+ */
+static inline int tcp_is_cwnd_limited(const struct sock *sk, u32 in_flight)
+{
+       const struct tcp_sock *tp = tcp_sk(sk);
+       u32 left;
+
+       if (in_flight >= tp->snd_cwnd)
+               return 1;
+
+       if (!(sk->sk_route_caps & NETIF_F_TSO))
+               return 0;
+
+       left = tp->snd_cwnd - in_flight;
+       if (sysctl_tcp_tso_win_divisor)
+               return left * sysctl_tcp_tso_win_divisor < tp->snd_cwnd;
+       else
+               return left <= tcp_max_burst(tp);
+}
+
 static __inline__ void tcp_minshall_update(struct tcp_sock *tp, int mss, 
                                           const struct sk_buff *skb)
 {