diff mbox series

[v2,net-next,04/15] tcp: accecn: add AccECN rx byte counters

Message ID 20250318002710.29483-5-chia-yu.chang@nokia-bell-labs.com (mailing list archive)
State New
Headers show
Series AccECN protocol patch series | expand

Commit Message

Chia-Yu Chang (Nokia) March 18, 2025, 12:26 a.m. UTC 
From: Ilpo Järvinen <ij@kernel.org>

These counters track IP ECN field payload byte sums for all
arriving (acceptable) packets. The AccECN option (added by
a later patch in the series) echoes these counters back to
sender side.

Signed-off-by: Ilpo Järvinen <ij@kernel.org>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com>
---
 include/linux/tcp.h      |  1 +
 include/net/tcp.h        | 18 +++++++++++++++++-
 net/ipv4/tcp.c           |  3 ++-
 net/ipv4/tcp_input.c     | 13 +++++++++----
 net/ipv4/tcp_minisocks.c |  3 ++-
 5 files changed, 31 insertions(+), 7 deletions(-)
diff mbox series

Patch

diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 2ddc9076235b..9de5090fadfb 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -300,6 +300,7 @@  struct tcp_sock {
 	u32	delivered;	/* Total data packets delivered incl. rexmits */
 	u32	delivered_ce;	/* Like the above but only ECE marked packets */
 	u32	received_ce;	/* Like the above but for rcvd CE marked pkts */
+	u32	received_ecn_bytes[3];
 	u8	received_ce_pending:4, /* Not yet transmit cnt of received_ce */
 		unused2:4;
 	u32	app_limited;	/* limited until "delivered" reaches this val */
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 93fffeb59a15..aff31ba1dea9 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -467,7 +467,8 @@  static inline int tcp_accecn_extract_syn_ect(u8 ace)
 bool tcp_accecn_validate_syn_feedback(struct sock *sk, u8 ace, u8 sent_ect);
 void tcp_accecn_third_ack(struct sock *sk, const struct sk_buff *skb,
 			  u8 syn_ect_snt);
-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);
 
 enum tcp_tw_status {
 	TCP_TW_SUCCESS = 0,
@@ -1034,11 +1035,26 @@  static inline u32 tcp_rsk_tsval(const struct tcp_request_sock *treq)
  * See draft-ietf-tcpm-accurate-ecn for the latest values.
  */
 #define TCP_ACCECN_CEP_INIT_OFFSET 5
+#define TCP_ACCECN_E1B_INIT_OFFSET 1
+#define TCP_ACCECN_E0B_INIT_OFFSET 1
+#define TCP_ACCECN_CEB_INIT_OFFSET 0
+
+static inline void __tcp_accecn_init_bytes_counters(int *counter_array)
+{
+	BUILD_BUG_ON(INET_ECN_ECT_1 != 0x1);
+	BUILD_BUG_ON(INET_ECN_ECT_0 != 0x2);
+	BUILD_BUG_ON(INET_ECN_CE != 0x3);
+
+	counter_array[INET_ECN_ECT_1 - 1] = 0;
+	counter_array[INET_ECN_ECT_0 - 1] = 0;
+	counter_array[INET_ECN_CE - 1] = 0;
+}
 
 static inline void tcp_accecn_init_counters(struct tcp_sock *tp)
 {
 	tp->received_ce = 0;
 	tp->received_ce_pending = 0;
+	__tcp_accecn_init_bytes_counters(tp->received_ecn_bytes);
 }
 
 /* State flags for sacked in struct tcp_skb_cb */
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 3c8894de5495..49289b5243e3 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -5063,6 +5063,7 @@  static void __init tcp_struct_check(void)
 	CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, delivered);
 	CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, delivered_ce);
 	CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, received_ce);
+	CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, received_ecn_bytes);
 	CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, app_limited);
 	CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, rcv_wnd);
 	CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_txrx, rx_opt);
@@ -5070,7 +5071,7 @@  static void __init tcp_struct_check(void)
 	/* 32bit arches with 8byte alignment on u64 fields might need padding
 	 * before tcp_clock_cache.
 	 */
-	CACHELINE_ASSERT_GROUP_SIZE(struct tcp_sock, tcp_sock_write_txrx, 97 + 7);
+	CACHELINE_ASSERT_GROUP_SIZE(struct tcp_sock, tcp_sock_write_txrx, 109 + 3);
 
 	/* RX read-write hotpath cache lines */
 	CACHELINE_ASSERT_GROUP_MEMBER(struct tcp_sock, tcp_sock_write_rx, bytes_received);
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 47da42707738..57e3cdb44a51 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -6107,7 +6107,8 @@  static void tcp_urg(struct sock *sk, struct sk_buff *skb, const struct tcphdr *t
 }
 
 /* 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);
@@ -6122,6 +6123,9 @@  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;
 	}
 }
 
@@ -6399,7 +6403,7 @@  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.
@@ -6445,7 +6449,8 @@  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);
@@ -6492,7 +6497,7 @@  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(sk, skb, len - th->doff * 4);
 
 	reason = tcp_ack(sk, skb, FLAG_SLOWPATH | FLAG_UPDATE_TS_RECENT);
 	if ((int)reason < 0) {
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 0e63f691a387..550c2d9d08b7 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -494,10 +494,11 @@  static void tcp_ecn_openreq_child(struct sock *sk,
 	struct tcp_sock *tp = tcp_sk(sk);
 
 	if (treq->accecn_ok) {
+		const struct tcphdr *th = (const struct tcphdr *)skb->data;
 		tcp_ecn_mode_set(tp, TCP_ECN_MODE_ACCECN);
 		tp->syn_ect_snt = treq->syn_ect_snt;
 		tcp_accecn_third_ack(sk, skb, treq->syn_ect_snt);
-		tcp_ecn_received_counters(sk, skb);
+		tcp_ecn_received_counters(sk, skb, skb->len - th->doff * 4);
 	} else {
 		tcp_ecn_mode_set(tp, inet_rsk(req)->ecn_ok ?
 				     TCP_ECN_MODE_RFC3168 :