ipv6: Revert "ipv6: Allow non-gateway ECMP for IPv6"

This reverts commit edd7ceb ("ipv6: Allow non-gateway ECMP for IPv6"). Eric reported a division by zero in rt6_multipath_rebalance() which is caused by above commit that considers identical local routes to be siblings. The division by zero happens because a nexthop weight is not set for local routes. Revert the commit as it does not fix a bug and has side effects. To reproduce: # ip -6 address add 2001:db8::1/64 dev dummy0 # ip -6 address add 2001:db8::1/64 dev dummy1 Fixes: edd7ceb ("ipv6: Allow non-gateway ECMP for IPv6") Signed-off-by: Ido Schimmel <[email protected]> Reported-by: Eric Dumazet <[email protected]> Tested-by: Eric Dumazet <[email protected]> Signed-off-by: David S. Miller <[email protected]>
ambv · May 2, 2018 · 30ca22e · 30ca22e
1 parent 784813a
commit 30ca22e
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diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
@@ -68,7 +68,8 @@ static inline bool rt6_need_strict(const struct in6_addr *daddr)
 
 static inline bool rt6_qualify_for_ecmp(const struct rt6_info *rt)
 {
-	return (rt->rt6i_flags & (RTF_ADDRCONF | RTF_DYNAMIC)) == 0;
+	return (rt->rt6i_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) ==
+	       RTF_GATEWAY;
 }
 
 void ip6_route_input(struct sk_buff *skb);

diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
@@ -934,6 +934,9 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
 			 * list.
 			 * Only static routes (which don't have flag
 			 * RTF_EXPIRES) are used for ECMPv6.
+			 *
+			 * To avoid long list, we only had siblings if the
+			 * route have a gateway.
 			 */
 			if (rt_can_ecmp &&
 			    rt6_qualify_for_ecmp(iter))