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author | Hannes Frederic Sowa <hannes@stressinduktion.org> | 2013-07-03 20:45:04 +0200 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-07-28 16:29:50 -0700 |
commit | c3a5491228f90fd82e67b7ccd2fcbaf984d44c07 (patch) | |
tree | 43a6b534063e550cabe28b13ae9fdee8f6738765 /net | |
parent | 7852c5bf367a01828edd02974c0a185b1be7b577 (diff) | |
download | linux-3.10-c3a5491228f90fd82e67b7ccd2fcbaf984d44c07.tar.gz linux-3.10-c3a5491228f90fd82e67b7ccd2fcbaf984d44c07.tar.bz2 linux-3.10-c3a5491228f90fd82e67b7ccd2fcbaf984d44c07.zip |
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')
-rw-r--r-- | net/ipv6/route.c | 2 |
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(); |