3 files changed, 17 insertions, 6 deletions

diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index 66fd80ef2473..5c24db4a3c91 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -358,7 +358,8 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
 
         tcp_select_initial_window(tcp_full_space(sk), req->mss,
                                   &req->rcv_wnd, &req->window_clamp,
-                                  ireq->wscale_ok, &rcv_wscale);
+                                  ireq->wscale_ok, &rcv_wscale,
+                                  dst_metric(&rt->u.dst, RTAX_INITRWND));
 
         ireq->rcv_wscale  = rcv_wscale;
 
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 12b2af36eab8..4a1605d3f909 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -183,7 +183,8 @@ static inline void tcp_event_ack_sent(struct sock *sk, unsigned int pkts)
  */
 void tcp_select_initial_window(int __space, __u32 mss,
                                __u32 *rcv_wnd, __u32 *window_clamp,
-                               int wscale_ok, __u8 *rcv_wscale)
+                               int wscale_ok, __u8 *rcv_wscale,
+                               __u32 init_rcv_wnd)
 {
         unsigned int space = (__space < 0 ? 0 : __space);
 
@@ -232,7 +233,13 @@ void tcp_select_initial_window(int __space, __u32 mss,
                         init_cwnd = 2;
                 else if (mss > 1460)
                         init_cwnd = 3;
-                if (*rcv_wnd > init_cwnd * mss)
+                /* when initializing use the value from init_rcv_wnd
+                 * rather than the default from above
+                 */
+                if (init_rcv_wnd &&
+                    (*rcv_wnd > init_rcv_wnd * mss))
+                        *rcv_wnd = init_rcv_wnd * mss;
+                else if (*rcv_wnd > init_cwnd * mss)
                         *rcv_wnd = init_cwnd * mss;
         }
 
@@ -2417,7 +2424,8 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
                         &req->rcv_wnd,
                         &req->window_clamp,
                         ireq->wscale_ok,
-                        &rcv_wscale);
+                        &rcv_wscale,
+                        dst_metric(dst, RTAX_INITRWND));
                 ireq->rcv_wscale = rcv_wscale;
         }
 
@@ -2544,7 +2552,8 @@ static void tcp_connect_init(struct sock *sk)
                                   &tp->rcv_wnd,
                                   &tp->window_clamp,
                                   sysctl_tcp_window_scaling,
-                                  &rcv_wscale);
+                                  &rcv_wscale,
+                                  dst_metric(dst, RTAX_INITRWND));
 
         tp->rx_opt.rcv_wscale = rcv_wscale;
         tp->rcv_ssthresh = tp->rcv_wnd;
diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
index 7208a06576c6..34d1f0690d7e 100644
--- a/net/ipv6/syncookies.c
+++ b/net/ipv6/syncookies.c
@@ -269,7 +269,8 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
         req->window_clamp = tp->window_clamp ? :dst_metric(dst, RTAX_WINDOW);
         tcp_select_initial_window(tcp_full_space(sk), req->mss,
                                   &req->rcv_wnd, &req->window_clamp,
-                                  ireq->wscale_ok, &rcv_wscale);
+                                  ireq->wscale_ok, &rcv_wscale,
+                                  dst_metric(dst, RTAX_INITRWND));
 
         ireq->rcv_wscale = rcv_wscale;