[RFC PATCH v2 4/5] tcp: added segment sent

[Natale Patriciello]

Inform the congestion control of the number of segment sent in normal
conditions, it means segments that left the node without involving
recovery or retransmission procedures.

Signed-off-by: Natale Patriciello <natale.patricie...@gmail.com>
---
 include/net/tcp.h     |  2 ++
 net/ipv4/tcp_output.c | 10 +++++++++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 3561eca5a61f..aebe225ab8b1 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1021,6 +1021,8 @@ struct tcp_congestion_ops {
        void (*pacing_timer_expired)(struct sock *sk);
        /* get the # segs to send out when the timer expires (optional) */
        u32 (*get_segs_per_round)(struct sock *sk);
+       /* the TCP has sent some segments (optional) */
+       void (*segments_sent)(struct sock *sk, u32 sent);
 
        char            name[TCP_CA_NAME_MAX];
        struct module   *owner;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index e37941e4328b..ef50202659da 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2250,6 +2250,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int 
mss_now, int nonagle,
        bool is_cwnd_limited = false, is_rwnd_limited = false;
        u32 max_segs;
        u32 pacing_allowed_segs = 0;
+       bool notify = false;
 
        sent_pkts = 0;
 
@@ -2268,8 +2269,12 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int 
mss_now, int nonagle,
 
        if (!tcp_pacing_timer_check(sk)) {
                pacing_allowed_segs = 1;
-               if (ca_ops && ca_ops->pacing_timer_expired)
+
+               if (ca_ops && ca_ops->pacing_timer_expired) {
                        ca_ops->pacing_timer_expired(sk);
+                       notify = true;
+               }
+
                if (ca_ops && ca_ops->get_segs_per_round)
                        pacing_allowed_segs = ca_ops->get_segs_per_round(sk);
        }
@@ -2348,6 +2353,9 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int 
mss_now, int nonagle,
                        break;
        }
 
+       if (ca_ops && notify && ca_ops->segments_sent)
+               ca_ops->segments_sent(sk, sent_pkts);
+
        if (is_rwnd_limited)
                tcp_chrono_start(sk, TCP_CHRONO_RWND_LIMITED);
        else
-- 
2.14.2