tcp: add rcv_wnd and plb_rehash to TCP_INFO

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>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
index c9abe86..879eeb0 100644 (file)
--- 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 1da7c53..de8f0cd 100644 (file)
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3940,6 +3940,8 @@ 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);
 }