ipv6: Add IFA_F_DADFAILED flag

Add IFA_F_DADFAILED flag to denote an IPv6 address that has
failed Duplicate Address Detection, that way tools like
/sbin/ip can be more informative.

3: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qlen 1000
    inet6 2001:db8::1/64 scope global tentative dadfailed
       valid_lft forever preferred_lft forever

Signed-off-by: Brian Haley <brian.haley@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 5 deletions

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 43b3c9f89c12..c9b369034a40 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -1371,12 +1371,14 @@ struct inet6_ifaddr *ipv6_get_ifaddr(struct net *net, const struct in6_addr *add
 
 /* Gets referenced address, destroys ifaddr */
 
-static void addrconf_dad_stop(struct inet6_ifaddr *ifp)
+static void addrconf_dad_stop(struct inet6_ifaddr *ifp, int dad_failed)
 {
         if (ifp->flags&IFA_F_PERMANENT) {
                 spin_lock_bh(&ifp->lock);
                 addrconf_del_timer(ifp);
                 ifp->flags |= IFA_F_TENTATIVE;
+                if (dad_failed)
+                        ifp->flags |= IFA_F_DADFAILED;
                 spin_unlock_bh(&ifp->lock);
                 in6_ifa_put(ifp);
 #ifdef CONFIG_IPV6_PRIVACY
@@ -1422,7 +1424,7 @@ void addrconf_dad_failure(struct inet6_ifaddr *ifp)
                 }
         }
 
-        addrconf_dad_stop(ifp);
+        addrconf_dad_stop(ifp, 1);
 }
 
 /* Join to solicited addr multicast group. */
@@ -2778,7 +2780,7 @@ static void addrconf_dad_start(struct inet6_ifaddr *ifp, u32 flags)
             idev->cnf.accept_dad < 1 ||
             !(ifp->flags&IFA_F_TENTATIVE) ||
             ifp->flags & IFA_F_NODAD) {
-                ifp->flags &= ~(IFA_F_TENTATIVE|IFA_F_OPTIMISTIC);
+                ifp->flags &= ~(IFA_F_TENTATIVE|IFA_F_OPTIMISTIC|IFA_F_DADFAILED);
                 spin_unlock_bh(&ifp->lock);
                 read_unlock_bh(&idev->lock);
 
@@ -2795,7 +2797,7 @@ static void addrconf_dad_start(struct inet6_ifaddr *ifp, u32 flags)
                  * - otherwise, kill it.
                  */
                 in6_ifa_hold(ifp);
-                addrconf_dad_stop(ifp);
+                addrconf_dad_stop(ifp, 0);
                 return;
         }
 
@@ -2829,7 +2831,7 @@ static void addrconf_dad_timer(unsigned long data)
                  * DAD was successful
                  */
 
-                ifp->flags &= ~(IFA_F_TENTATIVE|IFA_F_OPTIMISTIC);
+                ifp->flags &= ~(IFA_F_TENTATIVE|IFA_F_OPTIMISTIC|IFA_F_DADFAILED);
                 spin_unlock_bh(&ifp->lock);
                 read_unlock_bh(&idev->lock);