netdev - [PATCH net v2] ipv6: only static routes qualify for equal cost multipathing

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 12 Jul 2013 04:37:31 +0200
From:	Hannes Frederic Sowa <hannes@...essinduktion.org>
To:	netdev@...r.kernel.org
Subject: [PATCH net v2] 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 manually again without
   RTF_EXPIRES (or RA switches to infinite timeout), does not cause the
   rt6i_nsiblings logic to go wrong if a later RA updates the expiration
   time later.

Cc: Nicolas Dichtel <nicolas.dichtel@...nd.com>
Signed-off-by: Hannes Frederic Sowa <hannes@...essinduktion.org>
---
 net/ipv6/ip6_fib.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 192dd1a..662b90c 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -632,6 +632,13 @@ insert_above:
 	return ln;
 }
 
+static inline bool rt6_qualify_for_ecmp(struct rt6_info *rt)
+{
+	return (rt->rt6i_flags &
+		(RTF_EXPIRES|RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) ==
+	       RTF_GATEWAY;
+}
+
 /*
  *	Insert routing information in a node.
  */
@@ -646,6 +653,7 @@ 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 +699,8 @@ 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 +722,8 @@ 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;
-- 
1.8.1.4

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html