public inbox for netdev@vger.kernel.org 
 help / color / mirror / Atom feed
From: Eric Dumazet <eric.dumazet@gmail•com>
To: "David S . Miller" <davem@davemloft•net>,
	Jakub Kicinski <kuba@kernel•org>, Paolo Abeni <pabeni@redhat•com>
Cc: netdev <netdev@vger•kernel.org>,
	Eric Dumazet <edumazet@google•com>,
	Eric Dumazet <eric.dumazet@gmail•com>
Subject: [PATCH net-next 06/10] tcp: add two drop reasons for tcp_ack()
Date: Fri, 15 Apr 2022 17:10:44 -0700	[thread overview]
Message-ID: <20220416001048.2218911-7-eric.dumazet@gmail.com> (raw)
In-Reply-To: <20220416001048.2218911-1-eric.dumazet@gmail.com>

From: Eric Dumazet <edumazet@google•com>

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

Signed-off-by: Eric Dumazet <edumazet@google•com>
---
 include/linux/skbuff.h     | 2 ++
 include/trace/events/skb.h | 3 +++
 net/ipv4/tcp_input.c       | 7 ++++---
 3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 6f1410b5ff1372d9e1f7a75c303f8d7876c83ef0..9ff5557b190905f716a25f67113c1db822707959 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -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
diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h
index fbe21ad038bc6701ed04cb6be417c544de0dae84..eab0b09223f3c66255f930d44be61d45e83ca6e8 100644
--- a/include/trace/events/skb.h
+++ b/include/trace/events/skb.h
@@ -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)					\
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 85fae79c894d4b96820747c658bb4d884981c49e..8a68785b04053b8e622404035284920e51cd953c 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -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);
-- 
2.36.0.rc0.470.gd361397f0d-goog


  parent reply	other threads:[~2022-04-16  0:11 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-16  0:10 [PATCH net-next 00/10] tcp: drop reason additions Eric Dumazet
2022-04-16  0:10 ` [PATCH net-next 01/10] tcp: consume incoming skb leading to a reset Eric Dumazet
2022-04-16  0:10 ` [PATCH net-next 02/10] tcp: get rid of rst_seq_match Eric Dumazet
2022-04-16  0:10 ` [PATCH net-next 03/10] tcp: add drop reason support to tcp_validate_incoming() Eric Dumazet
2022-04-16  0:10 ` [PATCH net-next 04/10] tcp: make tcp_rcv_state_process() drop monitor friendly Eric Dumazet
2022-04-16  0:10 ` [PATCH net-next 05/10] tcp: add drop reasons to tcp_rcv_state_process() Eric Dumazet
2022-04-16  0:10 ` Eric Dumazet [this message]
2022-04-16  0:10 ` [PATCH net-next 07/10] tcp: add drop reason support to tcp_prune_ofo_queue() Eric Dumazet
2022-04-16  0:10 ` [PATCH net-next 08/10] tcp: make tcp_rcv_synsent_state_process() drop monitor friend Eric Dumazet
2022-04-16  0:10 ` [PATCH net-next 09/10] tcp: add drop reasons to tcp_rcv_synsent_state_process() Eric Dumazet
2022-04-16  0:10 ` [PATCH net-next 10/10] tcp: add drop reason support to tcp_ofo_queue() Eric Dumazet
2022-04-17 12:40 ` [PATCH net-next 00/10] tcp: drop reason additions patchwork-bot+netdevbpf

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20220416001048.2218911-7-eric.dumazet@gmail.com \
    --to=eric.dumazet@gmail$(echo .)com \
    --cc=davem@davemloft$(echo .)net \
    --cc=edumazet@google$(echo .)com \
    --cc=kuba@kernel$(echo .)org \
    --cc=netdev@vger$(echo .)kernel.org \
    --cc=pabeni@redhat$(echo .)com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox