1 files changed, 35 insertions, 0 deletions

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 0d60fbc59d8f..7e25043d826c 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -863,6 +863,41 @@ static int ip6_dst_lookup_tail(struct sock *sk,
                         goto out_err_release;
         }
 
+#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
+                /*
+                 * Here if the dst entry we've looked up
+                 * has a neighbour entry that is in the INCOMPLETE
+                 * state and the src address from the flow is
+                 * marked as OPTIMISTIC, we release the found
+                 * dst entry and replace it instead with the
+                 * dst entry of the nexthop router
+                 */
+                if (!((*dst)->neighbour->nud_state & NUD_VALID)) {
+                        struct inet6_ifaddr *ifp;
+                        struct flowi fl_gw;
+                        int redirect;
+
+                        ifp = ipv6_get_ifaddr(&fl->fl6_src, (*dst)->dev, 1);
+
+                        redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC);
+                        if (ifp)
+                                in6_ifa_put(ifp);
+
+                        if (redirect) {
+                                /*
+                                 * We need to get the dst entry for the
+                                 * default router instead
+                                 */
+                                dst_release(*dst);
+                                memcpy(&fl_gw, fl, sizeof(struct flowi));
+                                memset(&fl_gw.fl6_dst, 0, sizeof(struct in6_addr));
+                                *dst = ip6_route_output(sk, &fl_gw);
+                                if ((err = (*dst)->error))
+                                        goto out_err_release;
+                        }
+                }
+#endif
+
         return 0;
 
 out_err_release: