> -----Original Message-----
> From: Eric Dumazet <edumazet@xxxxxxxxxx>
> Sent: Wednesday, June 25, 2025 10:05 AM
> To: Chia-Yu Chang (Nokia) <chia-yu.chang@xxxxxxxxxxxxxxxxxxx>
> Cc: pabeni@xxxxxxxxxx; linux-doc@xxxxxxxxxxxxxxx; corbet@xxxxxxx; horms@xxxxxxxxxx; dsahern@xxxxxxxxxx; kuniyu@xxxxxxxxxx; bpf@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; dave.taht@xxxxxxxxx; jhs@xxxxxxxxxxxx; kuba@xxxxxxxxxx; stephen@xxxxxxxxxxxxxxxxxx; xiyou.wangcong@xxxxxxxxx; jiri@xxxxxxxxxxx; davem@xxxxxxxxxxxxx; andrew+netdev@xxxxxxx; donald.hunter@xxxxxxxxx; ast@xxxxxxxxxxx; liuhangbin@xxxxxxxxx; shuah@xxxxxxxxxx; linux-kselftest@xxxxxxxxxxxxxxx; ij@xxxxxxxxxx; ncardwell@xxxxxxxxxx; Koen De Schepper (Nokia) <koen.de_schepper@xxxxxxxxxxxxxxxxxxx>; g.white@xxxxxxxxxxxxx; ingemar.s.johansson@xxxxxxxxxxxx; mirja.kuehlewind@xxxxxxxxxxxx; cheshire@xxxxxxxxx; rs.ietf@xxxxxx; Jason_Livingood@xxxxxxxxxxx; vidhi_goel@xxxxxxxxx
> Subject: Re: [PATCH v9 net-next 06/15] tcp: accecn: add AccECN rx byte counters
>
>
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>
> On Sat, Jun 21, 2025 at 12:37 PM <chia-yu.chang@xxxxxxxxxxxxxxxxxxx> wrote:
> >
> > From: Ilpo Järvinen <ij@xxxxxxxxxx>
> >
[...]
> > --- a/net/ipv4/tcp_input.c
> > +++ b/net/ipv4/tcp_input.c
> > @@ -6013,8 +6013,17 @@ static void tcp_urg(struct sock *sk, struct sk_buff *skb, const struct tcphdr *t
> > }
> > }
> >
> > +void tcp_ecn_received_counters_payload(struct sock *sk,
> > + const struct sk_buff *skb) {
> > + const struct tcphdr *th = (const struct tcphdr *)skb->data;
> > +
> > + tcp_ecn_received_counters(sk, skb, skb->len - th->doff * 4); }
> > +
> > /* Updates Accurate ECN received counters from the received IP ECN
> > field */ -void tcp_ecn_received_counters(struct sock *sk, const struct
> > sk_buff *skb)
> > +void tcp_ecn_received_counters(struct sock *sk, const struct sk_buff *skb,
> > + u32 payload_len)
> > {
> > u8 ecnfield = TCP_SKB_CB(skb)->ip_dsfield & INET_ECN_MASK;
> > u8 is_ce = INET_ECN_is_ce(ecnfield); @@ -6034,6 +6043,9 @@
> > void tcp_ecn_received_counters(struct sock *sk, const struct sk_buff *skb)
> > tp->received_ce += pcount;
> > tp->received_ce_pending = min(tp->received_ce_pending + pcount,
> > 0xfU);
> > +
> > + if (payload_len > 0)
> > + tp->received_ecn_bytes[ecnfield - 1] +=
> > + payload_len;
> > }
> > }
> >
> > @@ -6307,7 +6319,7 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb)
> > flag |= __tcp_replace_ts_recent(tp,
> >
> > delta);
> >
> > - tcp_ecn_received_counters(sk, skb);
> > + tcp_ecn_received_counters(sk, skb, 0);
> >
> > /* We know that such packets are checksummed
> > * on entry.
> > @@ -6353,7 +6365,8 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb)
> > /* Bulk data transfer: receiver */
> > tcp_cleanup_skb(skb);
> > __skb_pull(skb, tcp_header_len);
> > - tcp_ecn_received_counters(sk, skb);
> > + tcp_ecn_received_counters(sk, skb,
> > + len -
> > + tcp_header_len);
> > eaten = tcp_queue_rcv(sk, skb, &fragstolen);
> >
> > tcp_event_data_recv(sk, skb); @@ -6400,7
> > +6413,7 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb)
> > tcp_accecn_third_ack(sk, skb, tp->syn_ect_snt);
> > tcp_fast_path_on(tp);
> > }
> > - tcp_ecn_received_counters(sk, skb);
> > + tcp_ecn_received_counters_payload(sk, skb);
>
> I missed this from a prior patch, but is it expected to account bytes even if the packet is dropped ?
>
Hi Eric,
What I know is that packets will be acoounted after validation.
So, if one packet is discarded due to tcp_validate_incoming(), it will NOT be counted in the AccECN counters.
Best regards,
Chia-Yu
