Index: sys/netpfil/ipfw/nat64/nat64lsn.c
===================================================================
--- sys/netpfil/ipfw/nat64/nat64lsn.c
+++ sys/netpfil/ipfw/nat64/nat64lsn.c
@@ -1143,26 +1143,27 @@
 	if (link == NULL)
 		return (PG_ERROR(1));
 
-	/*
-	 * TODO: check that we did not already allocated PG in
-	 *	 previous call.
-	 */
-
 	ret = 0;
 	alias = link->alias;
 	/* Find place in pgchunk where PG can be added */
 	switch (ji->proto) {
 	case IPPROTO_TCP:
+		if (!ck_pr_load_ptr(&alias->tcp_pg))
+			break;
 		ret = nat64lsn_alloc_proto_pg(cfg, alias,
 		    &alias->tcp_chunkmask, alias->tcp_pgmask,
 		    alias->tcp, &alias->tcp_pg, ji->proto);
 		break;
 	case IPPROTO_UDP:
+		if (!ck_pr_load_ptr(&alias->udp_pg))
+			break;
 		ret = nat64lsn_alloc_proto_pg(cfg, alias,
 		    &alias->udp_chunkmask, alias->udp_pgmask,
 		    alias->udp, &alias->udp_pg, ji->proto);
 		break;
 	case IPPROTO_ICMP:
+		if (!ck_pr_load_ptr(&alias->icmp_pg))
+			break;
 		ret = nat64lsn_alloc_proto_pg(cfg, alias,
 		    &alias->icmp_chunkmask, alias->icmp_pgmask,
 		    alias->icmp, &alias->icmp_pg, ji->proto);