tcp: ecn functions in separated include file

The following patches will modify ECN helpers and add AccECN herlpers,
and this patch moves the existing ones into a separated include file.

No functional changes.

Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250911110642.87529-5-chia-yu.chang@nokia-bell-labs.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 1 insertions, 44 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index f1be65af1a77..b2793e749cfd 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -72,6 +72,7 @@
 #include <linux/prefetch.h>
 #include <net/dst.h>
 #include <net/tcp.h>
+#include <net/tcp_ecn.h>
 #include <net/proto_memory.h>
 #include <net/inet_common.h>
 #include <linux/ipsec.h>
@@ -339,31 +340,6 @@ static bool tcp_in_quickack_mode(struct sock *sk)
 		(icsk->icsk_ack.quick && !inet_csk_in_pingpong_mode(sk));
 }
 
-static void tcp_ecn_queue_cwr(struct tcp_sock *tp)
-{
-	if (tcp_ecn_mode_rfc3168(tp))
-		tp->ecn_flags |= TCP_ECN_QUEUE_CWR;
-}
-
-static void tcp_ecn_accept_cwr(struct sock *sk, const struct sk_buff *skb)
-{
-	if (tcp_hdr(skb)->cwr) {
-		tcp_sk(sk)->ecn_flags &= ~TCP_ECN_DEMAND_CWR;
-
-		/* If the sender is telling us it has entered CWR, then its
-		 * cwnd may be very low (even just 1 packet), so we should ACK
-		 * immediately.
-		 */
-		if (TCP_SKB_CB(skb)->seq != TCP_SKB_CB(skb)->end_seq)
-			inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_NOW;
-	}
-}
-
-static void tcp_ecn_withdraw_cwr(struct tcp_sock *tp)
-{
-	tp->ecn_flags &= ~TCP_ECN_QUEUE_CWR;
-}
-
 static void tcp_data_ecn_check(struct sock *sk, const struct sk_buff *skb)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
@@ -399,25 +375,6 @@ static void tcp_data_ecn_check(struct sock *sk, const struct sk_buff *skb)
 	}
 }
 
-static void tcp_ecn_rcv_synack(struct tcp_sock *tp, const struct tcphdr *th)
-{
-	if (tcp_ecn_mode_rfc3168(tp) && (!th->ece || th->cwr))
-		tcp_ecn_mode_set(tp, TCP_ECN_DISABLED);
-}
-
-static void tcp_ecn_rcv_syn(struct tcp_sock *tp, const struct tcphdr *th)
-{
-	if (tcp_ecn_mode_rfc3168(tp) && (!th->ece || !th->cwr))
-		tcp_ecn_mode_set(tp, TCP_ECN_DISABLED);
-}
-
-static bool tcp_ecn_rcv_ecn_echo(const struct tcp_sock *tp, const struct tcphdr *th)
-{
-	if (th->ece && !th->syn && tcp_ecn_mode_rfc3168(tp))
-		return true;
-	return false;
-}
-
 static void tcp_count_delivered_ce(struct tcp_sock *tp, u32 ecn_count)
 {
 	tp->delivered_ce += ecn_count;