napt: Fix IP forwarding when forward netif enable NAPT

* Fix communication between different netifs fails if NAPT is enabled * Fixes IDF-4896
espressif · Sep 22, 2023 · bc78df8 · bc78df8
1 parent b55e64a
commit bc78df8
Showing 1 changed file with 5 additions and 2 deletions.
diff --git a/src/core/ipv4/ip4.c b/src/core/ipv4/ip4.c
@@ -332,8 +332,11 @@ ip4_forward(struct pbuf *p, struct ip_hdr *iphdr, struct netif *inp)
 
 #if ESP_LWIP
 #if IP_NAPT
-  if (ip_napt_forward(p, iphdr, inp, netif) != ERR_OK)
-    return;
+  /* If the output netif uses NAPT, we will not perform NAPT forwarding (because NAPT netif will not search the NAPT table on ip4_input) */
+  if (!netif->napt) {
+    if (ip_napt_forward(p, iphdr, inp, netif) != ERR_OK)
+      return;
+  }
 #endif
 #endif /* ESP_LWIP */