This reverts commit edd7ceb78296 ("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: edd7ceb78296 ("ipv6: Allow non-gateway ECMP for IPv6")
Signed-off-by: Ido Schimmel <[email protected]>
Reported-by: Eric Dumazet <[email protected]>
---
include/net/ip6_route.h | 3 ++-
net/ipv6/ip6_fib.c | 3 +++
2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index abceb5864d99..08b132381984 100644
--- 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
index 3c97c29d4401..deab2db6692e 100644
--- 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))
--
2.14.3
