tcp: add dsack blocks received stats
Introduce a new TCP stat to record the number of DSACK blocks received
(RFC4989 tcpEStatsStackDSACKDups) and expose it in both tcp_info
(TCP_INFO) and opt_stats (SOF_TIMESTAMPING_OPT_STATS).
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index fb67f9a..da6281c 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -188,6 +188,9 @@ struct tcp_sock {
* sum(delta(snd_una)), or how many bytes
* were acked.
*/
+ u32 dsack_dups; /* RFC4898 tcpEStatsStackDSACKDups
+ * total number of DSACK blocks received
+ */
u32 snd_una; /* First byte we want an ack for */
u32 snd_sml; /* Last byte of the most recently transmitted small packet */
u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */
diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h
index c31f510..0e1c0ae 100644
--- a/include/uapi/linux/tcp.h
+++ b/include/uapi/linux/tcp.h
@@ -238,6 +238,7 @@ struct tcp_info {
__u64 tcpi_bytes_sent; /* RFC4898 tcpEStatsPerfHCDataOctetsOut */
__u64 tcpi_bytes_retrans; /* RFC4898 tcpEStatsPerfOctetsRetrans */
+ __u32 tcpi_dsack_dups; /* RFC4898 tcpEStatsStackDSACKDups */
};
/* netlink attributes types for SCM_TIMESTAMPING_OPT_STATS */
@@ -262,6 +263,7 @@ enum {
TCP_NLA_DELIVERED_CE, /* Like above but only ones w/ CE marks */
TCP_NLA_BYTES_SENT, /* Data bytes sent including retransmission */
TCP_NLA_BYTES_RETRANS, /* Data bytes retransmitted */
+ TCP_NLA_DSACK_DUPS, /* DSACK blocks received */
};
/* for TCP_MD5SIG socket option */
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 5ed1be8..d6232b5 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2596,6 +2596,7 @@ int tcp_disconnect(struct sock *sk, int flags)
tp->compressed_ack = 0;
tp->bytes_sent = 0;
tp->bytes_retrans = 0;
+ tp->dsack_dups = 0;
/* Clean up fastopen related fields */
tcp_free_fastopen_req(tp);
@@ -3205,6 +3206,7 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info)
info->tcpi_delivered_ce = tp->delivered_ce;
info->tcpi_bytes_sent = tp->bytes_sent;
info->tcpi_bytes_retrans = tp->bytes_retrans;
+ info->tcpi_dsack_dups = tp->dsack_dups;
unlock_sock_fast(sk, slow);
}
EXPORT_SYMBOL_GPL(tcp_get_info);
@@ -3231,6 +3233,7 @@ static size_t tcp_opt_stats_get_size(void)
nla_total_size(sizeof(u32)) + /* TCP_NLA_DELIVERED_CE */
nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BYTES_SENT */
nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BYTES_RETRANS */
+ nla_total_size(sizeof(u32)) + /* TCP_NLA_DSACK_DUPS */
0;
}
@@ -3282,6 +3285,7 @@ struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk)
TCP_NLA_PAD);
nla_put_u64_64bit(stats, TCP_NLA_BYTES_RETRANS, tp->bytes_retrans,
TCP_NLA_PAD);
+ nla_put_u32(stats, TCP_NLA_DSACK_DUPS, tp->dsack_dups);
return stats;
}
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index d51fa35..fbc85ff 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -874,6 +874,7 @@ static void tcp_dsack_seen(struct tcp_sock *tp)
{
tp->rx_opt.sack_ok |= TCP_DSACK_SEEN;
tp->rack.dsack_seen = 1;
+ tp->dsack_dups++;
}
/* It's reordering when higher sequence was delivered (i.e. sacked) before