tcp: add related fields into SCM_TIMESTAMPING_OPT_STATS

Add the following stats into SCM_TIMESTAMPING_OPT_STATS control msg:
    TCP_NLA_PACING_RATE
    TCP_NLA_DELIVERY_RATE
    TCP_NLA_SND_CWND
    TCP_NLA_REORDERING
    TCP_NLA_MIN_RTT
    TCP_NLA_RECUR_RETRANS
    TCP_NLA_DELIVERY_RATE_APP_LMT

Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/tcp.h

@@ -231,6 +231,14 @@ enum {
 	TCP_NLA_SNDBUF_LIMITED,	/* Time (usec) limited by send buffer */
 	TCP_NLA_DATA_SEGS_OUT,	/* Data pkts sent including retransmission */
 	TCP_NLA_TOTAL_RETRANS,	/* Data pkts retransmitted */
+	TCP_NLA_PACING_RATE,    /* Pacing rate in bytes per second */
+	TCP_NLA_DELIVERY_RATE,  /* Delivery rate in bytes per second */
+	TCP_NLA_SND_CWND,       /* Sending congestion window */
+	TCP_NLA_REORDERING,     /* Reordering metric */
+	TCP_NLA_MIN_RTT,        /* minimum RTT */
+	TCP_NLA_RECUR_RETRANS,  /* Recurring retransmits for the current pkt */
+	TCP_NLA_DELIVERY_RATE_APP_LMT, /* delivery rate application limited ? */
+
 };
 
 /* for TCP_MD5SIG socket option */

net/ipv4/tcp.c

@@ -2840,8 +2840,12 @@ struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk)
 	const struct tcp_sock *tp = tcp_sk(sk);
 	struct sk_buff *stats;
 	struct tcp_info info;
+	u64 rate64;
+	u32 rate;
 
-	stats = alloc_skb(5 * nla_total_size_64bit(sizeof(u64)), GFP_ATOMIC);
+	stats = alloc_skb(7 * nla_total_size_64bit(sizeof(u64)) +
+			  3 * nla_total_size(sizeof(u32)) +
+			  2 * nla_total_size(sizeof(u8)), GFP_ATOMIC);
 	if (!stats)
 		return NULL;
 
@@ -2856,6 +2860,20 @@ struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk)
 			  tp->data_segs_out, TCP_NLA_PAD);
 	nla_put_u64_64bit(stats, TCP_NLA_TOTAL_RETRANS,
 			  tp->total_retrans, TCP_NLA_PAD);
+
+	rate = READ_ONCE(sk->sk_pacing_rate);
+	rate64 = rate != ~0U ? rate : ~0ULL;
+	nla_put_u64_64bit(stats, TCP_NLA_PACING_RATE, rate64, TCP_NLA_PAD);
+
+	rate64 = tcp_compute_delivery_rate(tp);
+	nla_put_u64_64bit(stats, TCP_NLA_DELIVERY_RATE, rate64, TCP_NLA_PAD);
+
+	nla_put_u32(stats, TCP_NLA_SND_CWND, tp->snd_cwnd);
+	nla_put_u32(stats, TCP_NLA_REORDERING, tp->reordering);
+	nla_put_u32(stats, TCP_NLA_MIN_RTT, tcp_min_rtt(tp));
+
+	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);
 	return stats;
 }