neigh: fix ARP retransmit timer guard

In commit 19e16d220f0a ("neigh: support smaller retrans_time settting")
we add more accurate control for ARP and NS. But for ARP I forgot to
update the latest guard in neigh_timer_handler(), then the next
retransmit would be reset to jiffies + HZ/2 if we set the retrans_time
less than 500ms. Fix it by setting the time_before() check to HZ/100.

IPv6 does not have this issue.

Reported-by: Jianwen Ji <jiji@redhat.com>
Fixes: 19e16d220f0a ("neigh: support smaller retrans_time settting")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 1161392..dbe0c6e 100644 (file)
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1082,8 +1082,8 @@ static void neigh_timer_handler(struct timer_list *t)
        }
 
        if (neigh->nud_state & NUD_IN_TIMER) {
-               if (time_before(next, jiffies + HZ/2))
-                       next = jiffies + HZ/2;
+               if (time_before(next, jiffies + HZ/100))
+                       next = jiffies + HZ/100;
                if (!mod_timer(&neigh->timer, next))
                        neigh_hold(neigh);
        }