Update nftable template to make acc snat rules

Change-Id: I9c4865f3372a10f546d7d884002dd707528715b2
diff --git a/templates/nftables.conf.j2 b/templates/nftables.conf.j2
index fda523a..c66cc9f 100644
--- a/templates/nftables.conf.j2
+++ b/templates/nftables.conf.j2
@@ -27,6 +27,9 @@
 
     # Allow SSH on all interfaces
     tcp dport ssh accept
+    # Allow IPsec ports on external interface
+    iif "{{ netprep_nftables["external_if"] }}" udp dport 500 accept
+    iif "{{ netprep_nftables["external_if"] }}" udp dport 4500 accept
 
     {% if "interface_subnets" in netprep_nftables %}
     # The ingress traffic restriction of internal networks
@@ -54,13 +57,21 @@
   chain postrouting {
     type nat hook postrouting priority 100;
     oifname "{{ netprep_nftables["external_if"] }}" masquerade;
-    {% if "ue_routing" in netprep_nftables %}
-    {% for src_subnet in netprep_nftables["ue_routing"]["src_subnets"] %}
-      {% for ue_subnet in netprep_nftables["ue_routing"]["ue_subnets"] %}
+
+    {% if "ue_routing" in netprep_nftables -%}
+    {%- for src_subnet in netprep_nftables["ue_routing"]["src_subnets"] -%}
+      {%- for ue_subnet in netprep_nftables["ue_routing"]["ue_subnets"] %}
     ip saddr {{ src_subnet }} ip daddr {{ ue_subnet }} counter snat to {{ netprep_nftables["ue_routing"]["snat_addr"] }};
       {% endfor %}
     {% endfor %}
+    {% endif %}
 
+    {% if "acc_routing" in netprep_nftables -%}
+    {%- for src_subnet in netprep_nftables["acc_routing"]["src_subnets"] -%}
+      {%- for acc_subnet in netprep_nftables["acc_routing"]["acc_subnets"] %}
+    ip saddr {{ src_subnet }} ip daddr {{ acc_subnet }} counter snat to {{ netprep_nftables["acc_routing"]["snat_addr"] }};
+      {% endfor %}
+    {% endfor %}
     {% endif %}
   }
 }