From e37d2e3e708db78f9b8f15eb34bb266cfae7bb42 Mon Sep 17 00:00:00 2001
From: "Ondrej Zajicek (work)" <santiago@crfreenet.org>
Date: Wed, 20 Jul 2016 15:06:57 +0200
Subject: [PATCH] Netlink: Ignore tentative addresses

Ignore tentative IPv6 addresses and wait until finish of Duplicate
Address Detection (We got notification when an address is no longer
tentative) to avoid problems when protocols try to use interfaces
with tentative link-local addresses.

Based on patch from Jan Moskyto Matejka
---
 sysdep/linux/netlink.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/sysdep/linux/netlink.c b/sysdep/linux/netlink.c
index b42e7b6f..f6cedbd8 100644
--- a/sysdep/linux/netlink.c
+++ b/sysdep/linux/netlink.c
@@ -247,18 +247,20 @@ static struct nl_want_attrs ifla_attr_want[BIRD_IFLA_MAX] = {
 };
 
 
-#define BIRD_IFA_MAX  (IFA_ANYCAST+1)
+#define BIRD_IFA_MAX  (IFA_FLAGS+1)
 
 #ifndef IPV6
 static struct nl_want_attrs ifa_attr_want4[BIRD_IFA_MAX] = {
   [IFA_ADDRESS]	  = { 1, 1, sizeof(ip4_addr) },
   [IFA_LOCAL]	  = { 1, 1, sizeof(ip4_addr) },
   [IFA_BROADCAST] = { 1, 1, sizeof(ip4_addr) },
+  [IFA_FLAGS]	  = { 1, 1, sizeof(u32) },
 };
 #else
 static struct nl_want_attrs ifa_attr_want6[BIRD_IFA_MAX] = {
   [IFA_ADDRESS]	  = { 1, 1, sizeof(ip6_addr) },
   [IFA_LOCAL]	  = { 1, 1, sizeof(ip6_addr) },
+  [IFA_FLAGS]	  = { 1, 1, sizeof(u32) },
 };
 #endif
 
@@ -611,6 +613,7 @@ nl_parse_addr(struct nlmsghdr *h, int scan)
   struct ifa ifa;
   struct iface *ifi;
   int scope;
+  u32 ifa_flags;
 
   if (!(i = nl_checkin(h, sizeof(*i))))
     return;
@@ -643,6 +646,11 @@ nl_parse_addr(struct nlmsghdr *h, int scan)
       return;
     }
 
+  if (a[IFA_FLAGS])
+    ifa_flags = rta_get_u32(a[IFA_FLAGS]);
+  else
+    ifa_flags = i->ifa_flags;
+
   ifi = if_find_by_index(i->ifa_index);
   if (!ifi)
     {
@@ -652,9 +660,15 @@ nl_parse_addr(struct nlmsghdr *h, int scan)
 
   bzero(&ifa, sizeof(ifa));
   ifa.iface = ifi;
-  if (i->ifa_flags & IFA_F_SECONDARY)
+  if (ifa_flags & IFA_F_SECONDARY)
     ifa.flags |= IA_SECONDARY;
 
+#ifdef IPV6
+  /* Ignore tentative addresses silently */
+  if (ifa_flags & IFA_F_TENTATIVE)
+    return;
+#endif
+
   /* IFA_LOCAL can be unset for IPv6 interfaces */
   memcpy(&ifa.ip, RTA_DATA(a[IFA_LOCAL] ? : a[IFA_ADDRESS]), sizeof(ifa.ip));
   ipa_ntoh(ifa.ip);