-----Original Message----- From: Eric Dumazet edumazet@google.com Sent: Wednesday, June 25, 2025 10:05 AM To: Chia-Yu Chang (Nokia) chia-yu.chang@nokia-bell-labs.com Cc: pabeni@redhat.com; linux-doc@vger.kernel.org; corbet@lwn.net; horms@kernel.org; dsahern@kernel.org; kuniyu@amazon.com; bpf@vger.kernel.org; netdev@vger.kernel.org; dave.taht@gmail.com; jhs@mojatatu.com; kuba@kernel.org; stephen@networkplumber.org; xiyou.wangcong@gmail.com; jiri@resnulli.us; davem@davemloft.net; andrew+netdev@lunn.ch; donald.hunter@gmail.com; ast@fiberby.net; liuhangbin@gmail.com; shuah@kernel.org; linux-kselftest@vger.kernel.org; ij@kernel.org; ncardwell@google.com; Koen De Schepper (Nokia) koen.de_schepper@nokia-bell-labs.com; g.white@cablelabs.com; ingemar.s.johansson@ericsson.com; mirja.kuehlewind@ericsson.com; cheshire@apple.com; rs.ietf@gmx.at; Jason_Livingood@comcast.com; vidhi_goel@apple.com Subject: Re: [PATCH v9 net-next 06/15] tcp: accecn: add AccECN rx byte counters
CAUTION: This is an external email. Please be very careful when clicking links or opening attachments. See the URL nok.it/ext for additional information.
On Sat, Jun 21, 2025 at 12:37 PM chia-yu.chang@nokia-bell-labs.com wrote:
From: Ilpo Järvinen ij@kernel.org
[...]
--- 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