--- elwix/patches/freebsd.pf.3whs.PR197484.patch	2017/06/13 17:50:07	1.1
+++ elwix/patches/freebsd.pf.3whs.PR197484.patch	2021/03/11 13:59:52	1.2
@@ -0,0 +1,13 @@
+Index: sys/netpfil/pf/pf.c
+===================================================================
+--- sys/netpfil/pf/pf.c	(revision 277815)
++++ sys/netpfil/pf/pf.c	(working copy)
+@@ -4199,7 +4199,7 @@
+ 			    TH_SYN|TH_ACK, 0, (*state)->src.mss, 0, 1, 0, NULL);
+ 			REASON_SET(reason, PFRES_SYNPROXY);
+ 			return (PF_SYNPROXY_DROP);
+-		} else if (!(th->th_flags & TH_ACK) ||
++		} else if ((th->th_flags & (TH_ACK|TH_RST|TH_FIN)) != TH_ACK ||
+ 		    (ntohl(th->th_ack) != (*state)->src.seqhi + 1) ||
+ 		    (ntohl(th->th_seq) != (*state)->src.seqlo + 1)) {
+ 			REASON_SET(reason, PFRES_SYNPROXY);