From 307f2fb95e9b96b3577916e73d92e104f8f26494 Mon Sep 17 00:00:00 2001 From: Hannes Frederic Sowa Date: Fri, 12 Jul 2013 23:46:33 +0200 Subject: [PATCH] ipv6: only static routes qualify for equal cost multipathing Static routes in this case are non-expiring routes which did not get configured by autoconf or by icmpv6 redirects. To make sure we actually get an ecmp route while searching for the first one in this fib6_node's leafs, also make sure it matches the ecmp route assumptions. v2: a) Removed RTF_EXPIRE check in dst.from chain. The check of RTF_ADDRCONF already ensures that this route, even if added again without RTF_EXPIRES (in case of a RA announcement with infinite timeout), does not cause the rt6i_nsiblings logic to go wrong if a later RA updates the expiration time later. v3: a) Allow RTF_EXPIRES routes to enter the ecmp route set. We have to do so, because an pmtu event could update the RTF_EXPIRES flag and we would not count this route, if another route joins this set. We now filter only for RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC, which are flags that don't get changed after rt6_info construction. Cc: Nicolas Dichtel Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller --- net/ipv6/ip6_fib.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index 192dd1a0e188..5fc9c7a68d8d 100644 --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -632,6 +632,12 @@ insert_above: return ln; } +static inline bool rt6_qualify_for_ecmp(struct rt6_info *rt) +{ + return (rt->rt6i_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) == + RTF_GATEWAY; +} + /* * Insert routing information in a node. */ @@ -646,6 +652,7 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt, int add = (!info->nlh || (info->nlh->nlmsg_flags & NLM_F_CREATE)); int found = 0; + bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); ins = &fn->leaf; @@ -691,9 +698,8 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt, * To avoid long list, we only had siblings if the * route have a gateway. */ - if (rt->rt6i_flags & RTF_GATEWAY && - !(rt->rt6i_flags & RTF_EXPIRES) && - !(iter->rt6i_flags & RTF_EXPIRES)) + if (rt_can_ecmp && + rt6_qualify_for_ecmp(iter)) rt->rt6i_nsiblings++; } @@ -715,7 +721,8 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt, /* Find the first route that have the same metric */ sibling = fn->leaf; while (sibling) { - if (sibling->rt6i_metric == rt->rt6i_metric) { + if (sibling->rt6i_metric == rt->rt6i_metric && + rt6_qualify_for_ecmp(sibling)) { list_add_tail(&rt->rt6i_siblings, &sibling->rt6i_siblings); break;