summaryrefslogtreecommitdiff
path: root/net/ipv4/tcp_output.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/ipv4/tcp_output.c')
-rw-r--r--net/ipv4/tcp_output.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 21e8a9f33287..c5eadec001c1 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -269,6 +269,7 @@ EXPORT_SYMBOL(tcp_select_initial_window);
static u16 tcp_select_window(struct sock *sk)
{
struct tcp_sock *tp = tcp_sk(sk);
+ u32 old_win = tp->rcv_wnd;
u32 cur_win = tcp_receive_window(tp);
u32 new_win = __tcp_select_window(sk);
@@ -281,6 +282,9 @@ static u16 tcp_select_window(struct sock *sk)
*
* Relax Will Robinson.
*/
+ if (new_win == 0)
+ NET_INC_STATS(sock_net(sk),
+ LINUX_MIB_TCPWANTZEROWINDOWADV);
new_win = ALIGN(cur_win, 1 << tp->rx_opt.rcv_wscale);
}
tp->rcv_wnd = new_win;
@@ -298,8 +302,14 @@ static u16 tcp_select_window(struct sock *sk)
new_win >>= tp->rx_opt.rcv_wscale;
/* If we advertise zero window, disable fast path. */
- if (new_win == 0)
+ if (new_win == 0) {
tp->pred_flags = 0;
+ if (old_win)
+ NET_INC_STATS(sock_net(sk),
+ LINUX_MIB_TCPTOZEROWINDOWADV);
+ } else if (old_win == 0) {
+ NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPFROMZEROWINDOWADV);
+ }
return new_win;
}