tcp: Add TCP_INFO counter for packets received out-of-order
For receive-heavy cases on the server-side, we want to track the
connection quality for individual client IPs. This counter, similar to
the existing system-wide TCPOFOQueue counter in /proc/net/netstat,
tracks out-of-order packet reception. By providing this counter in
TCP_INFO, it will allow understanding to what degree receive-heavy
sockets are experiencing out-of-order delivery and packet drops
indicating congestion.
Please note that this is similar to the counter in NetBSD TCP_INFO, and
has the same name.
Also note that we avoid increasing the size of the tcp_sock struct by
taking advantage of a hole.
Signed-off-by: Thomas Higdon <tph@fb.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 94df48b..4cf5820 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2653,6 +2653,7 @@ int tcp_disconnect(struct sock *sk, int flags)
tp->rx_opt.saw_tstamp = 0;
tp->rx_opt.dsack = 0;
tp->rx_opt.num_sacks = 0;
+ tp->rcv_ooopack = 0;
/* Clean up fastopen related fields */
@@ -3295,6 +3296,7 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info)
info->tcpi_bytes_retrans = tp->bytes_retrans;
info->tcpi_dsack_dups = tp->dsack_dups;
info->tcpi_reord_seen = tp->reord_seen;
+ info->tcpi_rcv_ooopack = tp->rcv_ooopack;
unlock_sock_fast(sk, slow);
}
EXPORT_SYMBOL_GPL(tcp_get_info);