From 12d976f7b5c8b644f58bff9af6c2d299c0887f1b Mon Sep 17 00:00:00 2001
From: Simon Duquennoy <simon.duquennoy@gmail.com>
Date: Thu, 6 Jul 2017 19:24:27 +0200
Subject: [PATCH] Emulate loopback: when sending an IP packet to one of our
 addresses, process it directly as input

---
 core/net/ip/tcpip.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/core/net/ip/tcpip.c b/core/net/ip/tcpip.c
index bf6d328e4..35600e7c6 100644
--- a/core/net/ip/tcpip.c
+++ b/core/net/ip/tcpip.c
@@ -672,6 +672,15 @@ tcpip_ipv6_output(void)
     goto send_packet;
   }
 
+  /* We first check if the destination address is one of ours. There is no
+   * loopback interface -- instead, process this directly as incoming. */
+  if(uip_ds6_is_my_addr(&UIP_IP_BUF->destipaddr)) {
+    LOG_INFO("output: sending to ourself\n");
+    packet_input();
+    return;
+  }
+
+  /* Look for a next hop */
   if((nexthop = get_nexthop(&ipaddr)) == NULL) {
     goto exit;
   }