From 0a7734cf648ec7b64b91fe9478e31c917aedb0a9 Mon Sep 17 00:00:00 2001
From: Dirk Ziegelmeier <dirk@ziegelmeier.net>
Date: Thu, 23 Feb 2017 16:36:40 +0100
Subject: [PATCH] Preparation for task #14369: Define ways to work with a netif
 having multiple ports Let ethernet_input() fill in pbuf's if_idx (if not
 already set by driver or an L2 bridge)

---
 src/netif/ethernet.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/netif/ethernet.c b/src/netif/ethernet.c
index 4596b32c..7270cfd8 100644
--- a/src/netif/ethernet.c
+++ b/src/netif/ethernet.c
@@ -94,6 +94,10 @@ ethernet_input(struct pbuf *p, struct netif *netif)
     goto free_and_return;
   }
 
+  if (p->if_idx == NETIF_NO_INDEX) {
+    p->if_idx = netif_get_index(netif);
+  }
+
   /* points to packet payload, which starts with an Ethernet header */
   ethhdr = (struct eth_hdr *)p->payload;
   LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE,