Commit 0df48c26 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

tcp: add tcpi_bytes_acked to tcp_info 



This patch tracks total number of bytes acked for a TCP socket.
This is the sum of all changes done to tp->snd_una, and allows
for precise tracking of delivered data.

RFC4898 named this : tcpEStatsAppHCThruOctetsAcked

This is a 64bit field, 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->bytes_acked was placed near tp->snd_una for
best data locality and minimal performance impact.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Acked-by: default avatarYuchung Cheng <ycheng@google.com>
Cc: Matt Mathis <mattmathis@google.com>
Cc: Eric Salo <salo@google.com>
Cc: Martin Lau <kafai@fb.com>
Cc: Chris Rapier <rapier@psc.edu>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2decb268

include/linux/tcp.h

+4 −0
Original line number Diff line number Diff line
@@ -150,6 +150,10 @@ struct tcp_sock { 
	u32	rcv_wup;	/* rcv_nxt on last window update sent	*/

 	u32	snd_nxt;	/* Next sequence we send		*/



	u64	bytes_acked;	/* RFC4898 tcpEStatsAppHCThruOctetsAcked

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

				 * were acked.

				 */

 	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) */

include/net/tcp.h

+1 −1
Original line number Diff line number Diff line
@@ -576,7 +576,7 @@ static inline int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize) 
}



/* tcp.c */

void tcp_get_info(const struct sock *, struct tcp_info *);

void tcp_get_info(struct sock *, struct tcp_info *);



/* Read 'sendfile()'-style from a TCP socket */

typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,

include/uapi/linux/tcp.h

+1 −0
Original line number Diff line number Diff line
@@ -189,6 +189,7 @@ struct tcp_info { 


	__u64	tcpi_pacing_rate;

	__u64	tcpi_max_pacing_rate;

	__u64	tcpi_bytes_acked; /* RFC4898 tcpEStatsAppHCThruOctetsAcked */

};



/* for TCP_MD5SIG socket option */

net/ipv4/tcp.c

+5 −1
Original line number Diff line number Diff line
@@ -2592,7 +2592,7 @@ EXPORT_SYMBOL(compat_tcp_setsockopt); 
#endif



/* Return information about state of tcp endpoint in API format. */

void tcp_get_info(const struct sock *sk, struct tcp_info *info)

void tcp_get_info(struct sock *sk, struct tcp_info *info)

{

	const struct tcp_sock *tp = tcp_sk(sk);

	const struct inet_connection_sock *icsk = inet_csk(sk);
@@ -2663,6 +2663,10 @@ void tcp_get_info(const struct sock *sk, struct tcp_info *info) 


	rate = READ_ONCE(sk->sk_max_pacing_rate);

	info->tcpi_max_pacing_rate = rate != ~0U ? rate : ~0ULL;



	spin_lock_bh(&sk->sk_lock.slock);

	info->tcpi_bytes_acked = tp->bytes_acked;

	spin_unlock_bh(&sk->sk_lock.slock);

}

EXPORT_SYMBOL_GPL(tcp_get_info);

net/ipv4/tcp_input.c

+11 −2
Original line number Diff line number Diff line
@@ -3280,6 +3280,15 @@ static inline bool tcp_may_update_window(const struct tcp_sock *tp, 
		(ack_seq == tp->snd_wl1 && nwin > tp->snd_wnd);

}



/* If we update tp->snd_una, also update tp->bytes_acked */

static void tcp_snd_una_update(struct tcp_sock *tp, u32 ack)

{

	u32 delta = ack - tp->snd_una;



	tp->bytes_acked += delta;

	tp->snd_una = ack;

}



/* Update our send window.

 *

 * Window update algorithm, described in RFC793/RFC1122 (used in linux-2.2
@@ -3315,7 +3324,7 @@ static int tcp_ack_update_window(struct sock *sk, const struct sk_buff *skb, u32 
		}

	}



	tp->snd_una = ack;

	tcp_snd_una_update(tp, ack);



	return flag;

}
@@ -3497,7 +3506,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag) 
		 * Note, we use the fact that SND.UNA>=SND.WL2.

		 */

		tcp_update_wl(tp, ack_seq);

		tp->snd_una = ack;

		tcp_snd_una_update(tp, ack);

		flag |= FLAG_WIN_UPDATE;



		tcp_in_ack_event(sk, CA_ACK_WIN_UPDATE);

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