tcp: add send queue size stat in SCM_TIMESTAMPING_OPT_STATS

This patch adds TCP_NLA_SENDQ_SIZE stat into SCM_TIMESTAMPING_OPT_STATS.
It reports no. of bytes present in send queue, when timestamp is
generated.

Signed-off-by: Priyaranjan Jha <priyarjha@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 1 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index a33539798bf6..162ba4227446 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3031,7 +3031,7 @@ struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk)
         u32 rate;
 
         stats = alloc_skb(7 * nla_total_size_64bit(sizeof(u64)) +
-                          3 * nla_total_size(sizeof(u32)) +
+                          4 * nla_total_size(sizeof(u32)) +
                           2 * nla_total_size(sizeof(u8)), GFP_ATOMIC);
         if (!stats)
                 return NULL;
@@ -3061,6 +3061,8 @@ struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk)
 
         nla_put_u8(stats, TCP_NLA_RECUR_RETRANS, inet_csk(sk)->icsk_retransmits);
         nla_put_u8(stats, TCP_NLA_DELIVERY_RATE_APP_LMT, !!tp->rate_app_limited);
+
+        nla_put_u32(stats, TCP_NLA_SNDQ_SIZE, tp->write_seq - tp->snd_una);
         return stats;
 }