From ed8d74879a1cfd79715d2384d4f67fa3d121a75c Mon Sep 17 00:00:00 2001
From: Tommaso Pecorella <tommaso.pecorella@unifi.it>
Date: Sun, 10 Oct 2021 00:09:00 +0200
Subject: [PATCH] internet: Fix src address selection for localhost

---
 src/internet/model/ipv6-l3-protocol.cc | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/internet/model/ipv6-l3-protocol.cc b/src/internet/model/ipv6-l3-protocol.cc
index edf5f60b8..e3f68c8ed 100644
--- a/src/internet/model/ipv6-l3-protocol.cc
+++ b/src/internet/model/ipv6-l3-protocol.cc
@@ -601,6 +601,11 @@ Ipv6Address Ipv6L3Protocol::SourceAddressSelection (uint32_t interface, Ipv6Addr
   NS_LOG_FUNCTION (this << interface << dest);
   Ipv6Address ret;
 
+  if (dest.IsLocalhost ())
+    {
+      return Ipv6Address::GetLoopback ();
+    }
+  
   if (dest.IsLinkLocal () || dest.IsLinkLocalMulticast ())
     {
       for (uint32_t i = 0; i < GetNAddresses (interface); i++)
@@ -632,6 +637,8 @@ Ipv6Address Ipv6L3Protocol::SourceAddressSelection (uint32_t interface, Ipv6Addr
     }
 
   // no specific match found. Use a global address (any useful is fine).
+  NS_ASSERT_MSG (!ret.IsAny (),
+                 "Could not find any address for " << dest << " on interface " << interface);
   return ret;
 }