Commit 4b506af9 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

tcp: add two drop reasons for tcp_ack() 



Add TCP_TOO_OLD_ACK and TCP_ACK_UNSENT_DATA drop
reasons so that tcp_rcv_established() can report
them.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 669da7a7

include/linux/skbuff.h

+2 −0
Original line number Diff line number Diff line
@@ -390,6 +390,8 @@ enum skb_drop_reason { 
	SKB_DROP_REASON_TCP_CLOSE,	/* TCP socket in CLOSE state */

	SKB_DROP_REASON_TCP_FASTOPEN,	/* dropped by FASTOPEN request socket */

	SKB_DROP_REASON_TCP_OLD_ACK,	/* TCP ACK is old, but in window */

	SKB_DROP_REASON_TCP_TOO_OLD_ACK, /* TCP ACK is too old */

	SKB_DROP_REASON_TCP_ACK_UNSENT_DATA, /* TCP ACK for data we haven't sent yet */

	SKB_DROP_REASON_IP_OUTNOROUTES,	/* route lookup failed */

	SKB_DROP_REASON_BPF_CGROUP_EGRESS,	/* dropped by

						 * BPF_PROG_TYPE_CGROUP_SKB

include/trace/events/skb.h

+3 −0
Original line number Diff line number Diff line
@@ -45,6 +45,9 @@ 
	EM(SKB_DROP_REASON_TCP_CLOSE, TCP_CLOSE)		\

	EM(SKB_DROP_REASON_TCP_FASTOPEN, TCP_FASTOPEN)		\

	EM(SKB_DROP_REASON_TCP_OLD_ACK, TCP_OLD_ACK)		\

	EM(SKB_DROP_REASON_TCP_TOO_OLD_ACK, TCP_TOO_OLD_ACK)	\

	EM(SKB_DROP_REASON_TCP_ACK_UNSENT_DATA,			\

	   TCP_ACK_UNSENT_DATA)					\

	EM(SKB_DROP_REASON_IP_OUTNOROUTES, IP_OUTNOROUTES)	\

	EM(SKB_DROP_REASON_BPF_CGROUP_EGRESS,			\

	   BPF_CGROUP_EGRESS)					\

net/ipv4/tcp_input.c

+4 −3
Original line number Diff line number Diff line
@@ -3766,7 +3766,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag) 
		if (before(ack, prior_snd_una - tp->max_window)) {

			if (!(flag & FLAG_NO_CHALLENGE_ACK))

				tcp_send_challenge_ack(sk);

			return -1;

			return -SKB_DROP_REASON_TCP_TOO_OLD_ACK;

		}

		goto old_ack;

	}
@@ -3775,7 +3775,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag) 
	 * this segment (RFC793 Section 3.9).

	 */

	if (after(ack, tp->snd_nxt))

		return -1;

		return -SKB_DROP_REASON_TCP_ACK_UNSENT_DATA;



	if (after(ack, prior_snd_una)) {

		flag |= FLAG_SND_UNA_ADVANCED;
@@ -5962,7 +5962,8 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb) 
		return;



step5:

	if (tcp_ack(sk, skb, FLAG_SLOWPATH | FLAG_UPDATE_TS_RECENT) < 0)

	reason = tcp_ack(sk, skb, FLAG_SLOWPATH | FLAG_UPDATE_TS_RECENT);

	if (reason < 0)

		goto discard;



	tcp_rcv_rtt_measure_ts(sk, skb);