Index: sys/net/if.c
===================================================================
RCS file: /mount/openbsd/cvs/src/sys/net/if.c,v
diff -u -p -u -p -r1.722 if.c
--- sys/net/if.c	16 Jan 2025 17:20:23 -0000	1.722
+++ sys/net/if.c	18 Jan 2025 23:15:49 -0000
@@ -981,6 +981,7 @@ void
 if_input_process(struct ifnet *ifp, struct mbuf_list *ml)
 {
 	struct mbuf *m;
+	struct softnet_storage thread_storage;
 
 	if (ml_empty(ml))
 		return;
@@ -995,10 +996,23 @@ if_input_process(struct ifnet *ifp, stru
 	 * read only or MP safe.  Usually they hold the exclusive net lock.
 	 */
 
+	ml_init(&thread_storage.sns_ml_tcp);
+	ml_init(&thread_storage.sns_ml_tcp6);
+
 	NET_LOCK_SHARED();
-	while ((m = ml_dequeue(ml)) != NULL)
+	while ((m = ml_dequeue(ml)) != NULL) {
+		m->m_pkthdr.ph_cookie = &thread_storage;
 		(*ifp->if_input)(ifp, m);
+	}
 	NET_UNLOCK_SHARED();
+
+	if (!ml_empty(&thread_storage.sns_ml_tcp) ||
+	    !ml_empty(&thread_storage.sns_ml_tcp6)) {
+		NET_LOCK();
+		tcp_input_mlist(&thread_storage.sns_ml_tcp, AF_INET);
+		tcp_input_mlist(&thread_storage.sns_ml_tcp6, AF_INET6);
+		NET_UNLOCK();
+	}
 }
 
 void
Index: sys/net/if_var.h
===================================================================
RCS file: /mount/openbsd/cvs/src/sys/net/if_var.h,v
diff -u -p -u -p -r1.133 if_var.h
--- sys/net/if_var.h	12 Oct 2024 23:18:10 -0000	1.133
+++ sys/net/if_var.h	18 Jan 2025 23:15:49 -0000
@@ -292,6 +292,11 @@ struct ifg_list {
 #define IF_WWAN_DEFAULT_PRIORITY	6
 #define IF_CARP_DEFAULT_PRIORITY	15
 
+struct softnet_storage {
+	struct mbuf_list	sns_ml_tcp;
+	struct mbuf_list	sns_ml_tcp6;
+};
+
 /*
  * Network stack input queues.
  */
Index: sys/netinet/in_proto.c
===================================================================
RCS file: /mount/openbsd/cvs/src/sys/netinet/in_proto.c,v
diff -u -p -u -p -r1.121 in_proto.c
--- sys/netinet/in_proto.c	5 Jan 2025 12:36:48 -0000	1.121
+++ sys/netinet/in_proto.c	18 Jan 2025 23:15:49 -0000
@@ -197,7 +197,8 @@ const struct protosw inetsw[] = {
   .pr_type	= SOCK_STREAM,
   .pr_domain	= &inetdomain,
   .pr_protocol	= IPPROTO_TCP,
-  .pr_flags	= PR_CONNREQUIRED|PR_WANTRCVD|PR_ABRTACPTDIS|PR_SPLICE,
+  .pr_flags	= PR_CONNREQUIRED|PR_WANTRCVD|PR_ABRTACPTDIS|PR_SPLICE|
+    PR_MPINPUT,
   .pr_input	= tcp_input,
   .pr_ctlinput	= tcp_ctlinput,
   .pr_ctloutput	= tcp_ctloutput,
Index: sys/netinet/tcp_input.c
===================================================================
RCS file: /mount/openbsd/cvs/src/sys/netinet/tcp_input.c,v
diff -u -p -u -p -r1.423 tcp_input.c
--- sys/netinet/tcp_input.c	16 Jan 2025 11:59:20 -0000	1.423
+++ sys/netinet/tcp_input.c	18 Jan 2025 23:15:49 -0000
@@ -100,9 +100,6 @@
 #include <net/pfvar.h>
 #endif
 
-int tcp_mss_adv(struct mbuf *, int);
-int tcp_flush_queue(struct tcpcb *);
-
 #ifdef INET6
 #include <netinet6/in6_var.h>
 #include <netinet6/nd6.h>
@@ -177,6 +174,9 @@ do { \
 	if_put(ifp); \
 } while (0)
 
+int	 tcp_input_mbuf(struct mbuf **, int *, int, int);
+int	 tcp_mss_adv(struct mbuf *, int);
+int	 tcp_flush_queue(struct tcpcb *);
 void	 tcp_sack_partialack(struct tcpcb *, struct tcphdr *);
 void	 tcp_newreno_partialack(struct tcpcb *, struct tcphdr *);
 
@@ -347,12 +347,54 @@ tcp_flush_queue(struct tcpcb *tp)
 	return (flags);
 }
 
+int
+tcp_input(struct mbuf **mp, int *offp, int proto, int af)
+{
+	struct softnet_storage *thread_storage;
+	struct mbuf_list *ml;
+
+	thread_storage = (*mp)->m_pkthdr.ph_cookie;
+	if (thread_storage == NULL)
+		return tcp_input_mbuf(mp, offp, proto, af);
+
+	(*mp)->m_pkthdr.ph_cookie = (void *)(long)(*offp);
+	switch (af) {
+	case AF_INET:
+		ml = &thread_storage->sns_ml_tcp;
+		break;
+#ifdef INET6
+	case AF_INET6:
+		ml = &thread_storage->sns_ml_tcp6;
+		break;
+#endif
+	default:
+		unhandled_af(af);
+	}
+	ml_enqueue(ml, *mp);
+	*mp = NULL;
+	return IPPROTO_DONE;
+}
+
+void
+tcp_input_mlist(struct mbuf_list *ml, int af)
+{
+	struct mbuf *m;
+	int off, nxt;
+
+	while ((m = ml_dequeue(ml)) != NULL) {
+		off = (long)m->m_pkthdr.ph_cookie;
+		m->m_pkthdr.ph_cookie = NULL;
+		nxt = tcp_input_mbuf(&m, &off, IPPROTO_TCP, af);
+		KASSERT(nxt == IPPROTO_DONE);
+	}
+}
+
 /*
  * TCP input routine, follows pages 65-76 of the
  * protocol specification dated September, 1981 very closely.
  */
 int
-tcp_input(struct mbuf **mp, int *offp, int proto, int af)
+tcp_input_mbuf(struct mbuf **mp, int *offp, int proto, int af)
 {
 	struct mbuf *m = *mp;
 	int iphlen = *offp;
Index: sys/netinet/tcp_var.h
===================================================================
RCS file: /mount/openbsd/cvs/src/sys/netinet/tcp_var.h,v
diff -u -p -u -p -r1.185 tcp_var.h
--- sys/netinet/tcp_var.h	16 Jan 2025 11:59:20 -0000	1.185
+++ sys/netinet/tcp_var.h	18 Jan 2025 23:15:49 -0000
@@ -718,6 +718,7 @@ int	 tcp_dooptions(struct tcpcb *, u_cha
 		struct mbuf *, int, struct tcp_opt_info *, u_int, uint64_t);
 void	 tcp_init(void);
 int	 tcp_input(struct mbuf **, int *, int, int);
+void	 tcp_input_mlist(struct mbuf_list *, int);
 int	 tcp_mss(struct tcpcb *, int);
 void	 tcp_mss_update(struct tcpcb *);
 u_int	 tcp_hdrsz(struct tcpcb *);
Index: sys/netinet6/in6_proto.c
===================================================================
RCS file: /mount/openbsd/cvs/src/sys/netinet6/in6_proto.c,v
diff -u -p -u -p -r1.124 in6_proto.c
--- sys/netinet6/in6_proto.c	5 Jan 2025 12:36:48 -0000	1.124
+++ sys/netinet6/in6_proto.c	18 Jan 2025 23:15:49 -0000
@@ -147,7 +147,8 @@ const struct protosw inet6sw[] = {
   .pr_type	= SOCK_STREAM,
   .pr_domain	= &inet6domain,
   .pr_protocol	= IPPROTO_TCP,
-  .pr_flags	= PR_CONNREQUIRED|PR_WANTRCVD|PR_ABRTACPTDIS|PR_SPLICE,
+  .pr_flags	= PR_CONNREQUIRED|PR_WANTRCVD|PR_ABRTACPTDIS|PR_SPLICE|
+    PR_MPINPUT,
   .pr_input	= tcp_input,
   .pr_ctlinput	= tcp6_ctlinput,
   .pr_ctloutput	= tcp_ctloutput,