[PATCH net-next v2 5/5] tcp: add rcv_wnd and plb_rehash to TCP_INFO

[Mubashir Adnan Qureshi <mubashirmaq@gmail.com>]

From: Mubashir Adnan Qureshi <mubashirq@google.com>

rcv_wnd can be useful to diagnose TCP performance where receiver window
becomes the bottleneck. rehash reports the PLB and timeout triggered
rehash attempts by the TCP connection.

Signed-off-by: Mubashir Adnan Qureshi <mubashirq@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
---
 include/uapi/linux/tcp.h | 5 +++++
 net/ipv4/tcp.c           | 2 ++
 2 files changed, 7 insertions(+)

diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
index c9abe86eda5f..879eeb0a084b 100644
--- a/include/uapi/linux/tcp.h
+++ b/include/uapi/linux/tcp.h
@@ -284,6 +284,11 @@ struct tcp_info {
 	__u32	tcpi_snd_wnd;	     /* peer's advertised receive window after
 				      * scaling (bytes)
 				      */
+	__u32	tcpi_rcv_wnd;	     /* local advertised receive window after
+				      * scaling (bytes)
+				      */
+
+	__u32   tcpi_rehash;         /* PLB or timeout triggered rehash attempts */
 };
 
 /* netlink attributes types for SCM_TIMESTAMPING_OPT_STATS */
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 685c06c6d33f..a0b518f63c3a 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3936,6 +3936,8 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info)
 	info->tcpi_reord_seen = tp->reord_seen;
 	info->tcpi_rcv_ooopack = tp->rcv_ooopack;
 	info->tcpi_snd_wnd = tp->snd_wnd;
+	info->tcpi_rcv_wnd = tp->rcv_wnd;
+	info->tcpi_rehash = tp->plb_rehash + tp->timeout_rehash;
 	info->tcpi_fastopen_client_fail = tp->fastopen_client_fail;
 	unlock_sock_fast(sk, slow);
 }
-- 
2.38.0.rc1.362.ged0d419d3c-goog