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authorHannes Frederic Sowa <hannes@stressinduktion.org>2013-07-03 20:45:04 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-07-28 16:29:50 -0700
commitc3a5491228f90fd82e67b7ccd2fcbaf984d44c07 (patch)
tree43a6b534063e550cabe28b13ae9fdee8f6738765 /net/ipv6
parent7852c5bf367a01828edd02974c0a185b1be7b577 (diff)
ipv6: rt6_check_neigh should successfully verify neigh if no NUD information are available
[ Upstream commit 3630d40067a21d4dfbadc6002bb469ce26ac5d52 ] After the removal of rt->n we do not create a neighbour entry at route insertion time (rt6_bind_neighbour is gone). As long as no neighbour is created because of "useful traffic" we skip this routing entry because rt6_check_neigh cannot pick up a valid neighbour (neigh == NULL) and thus returns false. This change was introduced by commit 887c95cc1da53f66a5890fdeab13414613010097 ("ipv6: Complete neighbour entry removal from dst_entry.") To quote RFC4191: "If the host has no information about the router's reachability, then the host assumes the router is reachable." and also: "A host MUST NOT probe a router's reachability in the absence of useful traffic that the host would have sent to the router if it were reachable." So, just assume the router is reachable and let's rt6_probe do the rest. We don't need to create a neighbour on route insertion time. If we don't compile with CONFIG_IPV6_ROUTER_PREF (RFC4191 support) a neighbour is only valid if its nud_state is NUD_VALID. I did not find any references that we should probe the router on route insertion time via the other RFCs. So skip this route in that case. v2: a) use IS_ENABLED instead of #ifdefs (thanks to Sergei Shtylyov) Reported-by: Pierre Emeriaud <petrus.lt@gmail.com> Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/ipv6')
-rw-r--r--net/ipv6/route.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index ad0aa6b0b86..7f1332fc434 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -547,6 +547,8 @@ static inline bool rt6_check_neigh(struct rt6_info *rt)
ret = true;
#endif
read_unlock(&neigh->lock);
+ } else if (IS_ENABLED(CONFIG_IPV6_ROUTER_PREF)) {
+ ret = true;
}
rcu_read_unlock_bh();