From 2a82db4cafbb826ecfd84b79d8c7ffac6d99b285 Mon Sep 17 00:00:00 2001
From: Simon Kelley <simon@thekelleys.org.uk>
Date: Sat, 10 Mar 2012 21:40:10 +0000
Subject: [PATCH] Supply zero preference in advertise and reply messages

---
 src/option.c  | 2 +-
 src/rfc3315.c | 6 +++++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/option.c b/src/option.c
index 9259430..050a953 100644
--- a/src/option.c
+++ b/src/option.c
@@ -580,7 +580,7 @@ char *option_string(int prot, unsigned int opt, unsigned char *val, int opt_len,
 	break;
       }
 
-  if (buf && (!ot[o].name || nodecode))
+  if (opt_len != 0 && buf && (!ot[o].name || nodecode))
     {
       int trunc  = 0;
       if (opt_len > 13)
diff --git a/src/rfc3315.c b/src/rfc3315.c
index f28f5f6..b0c31ad 100644
--- a/src/rfc3315.c
+++ b/src/rfc3315.c
@@ -763,7 +763,11 @@ static int dhcp6_no_relay(int msg_type, struct in6_addr *link_address, struct dh
 		      }
 		    
 		    end_opt6(o);
-		    
+		    	
+		    o = new_opt6(OPTION6_PREFERENCE);
+		    put_opt6_char(0);
+		    end_opt6(o);
+
 		    break;
 		  }
 	      }