tcp: move tcp_v6_early_demux() to net/ipv6/ip6_input.c

tcp_v6_early_demux() has a single caller : ip6_rcv_finish_core().

Move it to net/ipv6/ip6_input.c and mark it static, for possible
compiler/linker optimizations.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260304022706.1062459-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 40 insertions, 39 deletions

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 3f1fe954e6aa..a64641423806 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1142,7 +1142,6 @@ static inline int tcp_v6_sdif(const struct sk_buff *skb)
 extern const struct inet_connection_sock_af_ops ipv6_specific;
 
 INDIRECT_CALLABLE_DECLARE(int tcp_v6_rcv(struct sk_buff *skb));
-void tcp_v6_early_demux(struct sk_buff *skb);
 
 #endif
 
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index 2bcb981c91aa..967b07aeb683 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -44,6 +44,46 @@
 #include <net/xfrm.h>
 #include <net/inet_ecn.h>
 #include <net/dst_metadata.h>
+#include <net/inet6_hashtables.h>
+
+static void tcp_v6_early_demux(struct sk_buff *skb)
+{
+	struct net *net = dev_net_rcu(skb->dev);
+	const struct ipv6hdr *hdr;
+	const struct tcphdr *th;
+	struct sock *sk;
+
+	if (skb->pkt_type != PACKET_HOST)
+		return;
+
+	if (!pskb_may_pull(skb, skb_transport_offset(skb) +
+				sizeof(struct tcphdr)))
+		return;
+
+	hdr = ipv6_hdr(skb);
+	th = tcp_hdr(skb);
+
+	if (th->doff < sizeof(struct tcphdr) / 4)
+		return;
+
+	/* Note : We use inet6_iif() here, not tcp_v6_iif() */
+	sk = __inet6_lookup_established(net, &hdr->saddr, th->source,
+					&hdr->daddr, ntohs(th->dest),
+					inet6_iif(skb), inet6_sdif(skb));
+	if (sk) {
+		skb->sk = sk;
+		skb->destructor = sock_edemux;
+		if (sk_fullsock(sk)) {
+			struct dst_entry *dst = rcu_dereference(sk->sk_rx_dst);
+
+			if (dst)
+				dst = dst_check(dst, sk->sk_rx_dst_cookie);
+			if (dst &&
+			    sk->sk_rx_dst_ifindex == skb->skb_iif)
+				skb_dst_set_noref(skb, dst);
+		}
+	}
+}
 
 static void ip6_rcv_finish_core(struct net *net, struct sock *sk,
 				struct sk_buff *skb)
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index a62dd2999aec..164dceb842af 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1972,44 +1972,6 @@ do_time_wait:
 	goto discard_it;
 }
 
-void tcp_v6_early_demux(struct sk_buff *skb)
-{
-	struct net *net = dev_net_rcu(skb->dev);
-	const struct ipv6hdr *hdr;
-	const struct tcphdr *th;
-	struct sock *sk;
-
-	if (skb->pkt_type != PACKET_HOST)
-		return;
-
-	if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
-		return;
-
-	hdr = ipv6_hdr(skb);
-	th = tcp_hdr(skb);
-
-	if (th->doff < sizeof(struct tcphdr) / 4)
-		return;
-
-	/* Note : We use inet6_iif() here, not tcp_v6_iif() */
-	sk = __inet6_lookup_established(net, &hdr->saddr, th->source,
-					&hdr->daddr, ntohs(th->dest),
-					inet6_iif(skb), inet6_sdif(skb));
-	if (sk) {
-		skb->sk = sk;
-		skb->destructor = sock_edemux;
-		if (sk_fullsock(sk)) {
-			struct dst_entry *dst = rcu_dereference(sk->sk_rx_dst);
-
-			if (dst)
-				dst = dst_check(dst, sk->sk_rx_dst_cookie);
-			if (dst &&
-			    sk->sk_rx_dst_ifindex == skb->skb_iif)
-				skb_dst_set_noref(skb, dst);
-		}
-	}
-}
-
 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
 	.twsk_obj_size	= sizeof(struct tcp6_timewait_sock),
 };