Commit 30ca22e4 authored by Ido Schimmel's avatar Ido Schimmel Committed by David S. Miller

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

This reverts commit edd7ceb7 ("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: edd7ceb7 ("ipv6: Allow non-gateway ECMP for IPv6")
Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Reported-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Tested-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 784813ae
...@@ -68,7 +68,8 @@ static inline bool rt6_need_strict(const struct in6_addr *daddr) ...@@ -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) 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); void ip6_route_input(struct sk_buff *skb);
......
...@@ -934,6 +934,9 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt, ...@@ -934,6 +934,9 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
* list. * list.
* Only static routes (which don't have flag * Only static routes (which don't have flag
* RTF_EXPIRES) are used for ECMPv6. * RTF_EXPIRES) are used for ECMPv6.
*
* To avoid long list, we only had siblings if the
* route have a gateway.
*/ */
if (rt_can_ecmp && if (rt_can_ecmp &&
rt6_qualify_for_ecmp(iter)) rt6_qualify_for_ecmp(iter))
......
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