Commit f19c29e3 authored by Yuchung Cheng's avatar Yuchung Cheng Committed by David S. Miller
Browse files

tcp: snmp stats for Fast Open, SYN rtx, and data pkts 



Add the following snmp stats:

TCPFastOpenActiveFail: Fast Open attempts (SYN/data) failed beacuse
the remote does not accept it or the attempts timed out.

TCPSynRetrans: number of SYN and SYN/ACK retransmits to break down
retransmissions into SYN, fast-retransmits, timeout retransmits, etc.

TCPOrigDataSent: number of outgoing packets with original data (excluding
retransmission but including data-in-SYN). This counter is different from
TcpOutSegs because TcpOutSegs also tracks pure ACKs. TCPOrigDataSent is
more useful to track the TCP retransmission rate.

Change TCPFastOpenActive to track only successful Fast Opens to be symmetric to
TCPFastOpenPassive.

Signed-off-by: default avatarYuchung Cheng <ycheng@google.com>
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarNandita Dukkipati <nanditad@google.com>
Signed-off-by: default avatarLawrence Brakmo <brakmo@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a135e598

include/uapi/linux/snmp.h

+3 −0
Original line number Diff line number Diff line
@@ -252,6 +252,7 @@ enum 
	LINUX_MIB_TCPCHALLENGEACK,		/* TCPChallengeACK */

	LINUX_MIB_TCPSYNCHALLENGE,		/* TCPSYNChallenge */

	LINUX_MIB_TCPFASTOPENACTIVE,		/* TCPFastOpenActive */

	LINUX_MIB_TCPFASTOPENACTIVEFAIL,	/* TCPFastOpenActiveFail */

	LINUX_MIB_TCPFASTOPENPASSIVE,		/* TCPFastOpenPassive*/

	LINUX_MIB_TCPFASTOPENPASSIVEFAIL,	/* TCPFastOpenPassiveFail */

	LINUX_MIB_TCPFASTOPENLISTENOVERFLOW,	/* TCPFastOpenListenOverflow */
@@ -262,6 +263,8 @@ enum 
	LINUX_MIB_TCPFROMZEROWINDOWADV,		/* TCPFromZeroWindowAdv */

	LINUX_MIB_TCPTOZEROWINDOWADV,		/* TCPToZeroWindowAdv */

	LINUX_MIB_TCPWANTZEROWINDOWADV,		/* TCPWantZeroWindowAdv */

	LINUX_MIB_TCPSYNRETRANS,		/* TCPSynRetrans */

	LINUX_MIB_TCPORIGDATASENT,		/* TCPOrigDataSent */

	__LINUX_MIB_MAX

};

net/ipv4/proc.c

+3 −0
Original line number Diff line number Diff line
@@ -273,6 +273,7 @@ static const struct snmp_mib snmp4_net_list[] = { 
	SNMP_MIB_ITEM("TCPChallengeACK", LINUX_MIB_TCPCHALLENGEACK),

	SNMP_MIB_ITEM("TCPSYNChallenge", LINUX_MIB_TCPSYNCHALLENGE),

	SNMP_MIB_ITEM("TCPFastOpenActive", LINUX_MIB_TCPFASTOPENACTIVE),

	SNMP_MIB_ITEM("TCPFastOpenActiveFail", LINUX_MIB_TCPFASTOPENACTIVEFAIL),

	SNMP_MIB_ITEM("TCPFastOpenPassive", LINUX_MIB_TCPFASTOPENPASSIVE),

	SNMP_MIB_ITEM("TCPFastOpenPassiveFail", LINUX_MIB_TCPFASTOPENPASSIVEFAIL),

	SNMP_MIB_ITEM("TCPFastOpenListenOverflow", LINUX_MIB_TCPFASTOPENLISTENOVERFLOW),
@@ -283,6 +284,8 @@ static const struct snmp_mib snmp4_net_list[] = { 
	SNMP_MIB_ITEM("TCPFromZeroWindowAdv", LINUX_MIB_TCPFROMZEROWINDOWADV),

	SNMP_MIB_ITEM("TCPToZeroWindowAdv", LINUX_MIB_TCPTOZEROWINDOWADV),

	SNMP_MIB_ITEM("TCPWantZeroWindowAdv", LINUX_MIB_TCPWANTZEROWINDOWADV),

	SNMP_MIB_ITEM("TCPSynRetrans", LINUX_MIB_TCPSYNRETRANS),

	SNMP_MIB_ITEM("TCPOrigDataSent", LINUX_MIB_TCPORIGDATASENT),

	SNMP_MIB_SENTINEL

};

net/ipv4/tcp_input.c

+3 −0
Original line number Diff line number Diff line
@@ -5393,9 +5393,12 @@ static bool tcp_rcv_fastopen_synack(struct sock *sk, struct sk_buff *synack, 
				break;

		}

		tcp_rearm_rto(sk);

		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPFASTOPENACTIVEFAIL);

		return true;

	}

	tp->syn_data_acked = tp->syn_data;

	if (tp->syn_data_acked)

		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPFASTOPENACTIVE);

	return false;

}

net/ipv4/tcp_ipv4.c

+3 −1
Original line number Diff line number Diff line
@@ -854,8 +854,10 @@ static int tcp_v4_rtx_synack(struct sock *sk, struct request_sock *req) 
{

	int res = tcp_v4_send_synack(sk, NULL, req, 0);



	if (!res)

	if (!res) {

		TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);

		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPSYNRETRANS);

	}

	return res;

}

net/ipv4/tcp_output.c

+6 −2
Original line number Diff line number Diff line
@@ -86,6 +86,9 @@ static void tcp_event_new_data_sent(struct sock *sk, const struct sk_buff *skb) 
	    icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {

		tcp_rearm_rto(sk);

	}



	NET_ADD_STATS_BH(sock_net(sk), LINUX_MIB_TCPORIGDATASENT,

			 tcp_skb_pcount(skb));

}



/* SND.NXT, if window was not shrunk.
@@ -2433,7 +2436,8 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb) 
	if (err == 0) {

		/* Update global TCP statistics. */

		TCP_INC_STATS(sock_net(sk), TCP_MIB_RETRANSSEGS);



		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)

			NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPSYNRETRANS);

		tp->total_retrans++;



#if FASTRETRANS_DEBUG > 0
@@ -2958,7 +2962,7 @@ static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn) 


	if (tcp_transmit_skb(sk, syn_data, 0, sk->sk_allocation) == 0) {

		tp->syn_data = (fo->copied > 0);

		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPFASTOPENACTIVE);

		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPORIGDATASENT);

		goto done;

	}

	syn_data = NULL;

CRA Git | Maintained and supported by SUSTech CRA and CCSE