Commit 2efd055c authored by Marcelo Ricardo Leitner's avatar Marcelo Ricardo Leitner Committed by David S. Miller
Browse files

tcp: add tcpi_segs_in and tcpi_segs_out to tcp_info 



This patch tracks the total number of inbound and outbound segments on a
TCP socket. One may use this number to have an idea on connection
quality when compared against the retransmissions.

RFC4898 named these : tcpEStatsPerfSegsIn and tcpEStatsPerfSegsOut

These are a 32bit field each and can be fetched both from TCP_INFO
getsockopt() if one has a handle on a TCP socket, or from inet_diag
netlink facility (iproute2/ss patch will follow)

Note that tp->segs_out was placed near tp->snd_nxt for good data
locality and minimal performance impact, while tp->segs_in was placed
near tp->bytes_received for the same reason.

Join work with Eric Dumazet.

Note that received SYN are accounted on the listener, but sent SYNACK
are not accounted.

Signed-off-by: default avatarMarcelo Ricardo Leitner <mleitner@redhat.com>
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 48ed7b26

include/linux/tcp.h

+6 −1
Original line number Diff line number Diff line
@@ -149,11 +149,16 @@ struct tcp_sock { 
				 * sum(delta(rcv_nxt)), or how many bytes

				 * were acked.

				 */

	u32	segs_in;	/* RFC4898 tcpEStatsPerfSegsIn

				 * total number of segments in.

				 */

 	u32	rcv_nxt;	/* What we want to receive next 	*/

	u32	copied_seq;	/* Head of yet unread data		*/

	u32	rcv_wup;	/* rcv_nxt on last window update sent	*/

 	u32	snd_nxt;	/* Next sequence we send		*/



	u32	segs_out;	/* RFC4898 tcpEStatsPerfSegsOut

				 * The total number of segments sent.

				 */

	u64	bytes_acked;	/* RFC4898 tcpEStatsAppHCThruOctetsAcked

				 * sum(delta(snd_una)), or how many bytes

				 * were acked.

include/uapi/linux/tcp.h

+3 −1
Original line number Diff line number Diff line
@@ -194,6 +194,8 @@ struct tcp_info { 
	__u64	tcpi_max_pacing_rate;

	__u64	tcpi_bytes_acked;    /* RFC4898 tcpEStatsAppHCThruOctetsAcked */

	__u64	tcpi_bytes_received; /* RFC4898 tcpEStatsAppHCThruOctetsReceived */

	__u32	tcpi_segs_out;	     /* RFC4898 tcpEStatsPerfSegsOut */

	__u32	tcpi_segs_in;	     /* RFC4898 tcpEStatsPerfSegsIn */

};



/* for TCP_MD5SIG socket option */

net/ipv4/tcp.c

+2 −0
Original line number Diff line number Diff line
@@ -2695,6 +2695,8 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info) 
	spin_lock_bh(&sk->sk_lock.slock);

	info->tcpi_bytes_acked = tp->bytes_acked;

	info->tcpi_bytes_received = tp->bytes_received;

	info->tcpi_segs_out = tp->segs_out;

	info->tcpi_segs_in = tp->segs_in;

	spin_unlock_bh(&sk->sk_lock.slock);

}

EXPORT_SYMBOL_GPL(tcp_get_info);

net/ipv4/tcp_ipv4.c

+1 −0
Original line number Diff line number Diff line
@@ -1626,6 +1626,7 @@ process: 
	skb->dev = NULL;



	bh_lock_sock_nested(sk);

	tcp_sk(sk)->segs_in += max_t(u16, 1, skb_shinfo(skb)->gso_segs);

	ret = 0;

	if (!sock_owned_by_user(sk)) {

		if (!tcp_prequeue(sk, skb))

net/ipv4/tcp_minisocks.c

+1 −0
Original line number Diff line number Diff line
@@ -448,6 +448,7 @@ struct sock *tcp_create_openreq_child(struct sock *sk, struct request_sock *req, 


		newtp->rcv_wup = newtp->copied_seq =

		newtp->rcv_nxt = treq->rcv_isn + 1;

		newtp->segs_in = 0;



		newtp->snd_sml = newtp->snd_una =

		newtp->snd_nxt = newtp->snd_up = treq->snt_isn + 1;

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