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author | Paul Marks <pmarks@google.com> | 2012-12-03 10:26:54 +0000 |
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committer | David S. Miller <davem@davemloft.net> | 2012-12-03 15:34:47 -0500 |
commit | a5a81f0b9025867efb999d14a8dfc1907c5a4c3b (patch) | |
tree | 4b2de223b5e08e0dcd4604d3619c738ff45eb2d3 /init | |
parent | 5d097109257c03a71845729f8db6b5770c4bbedc (diff) | |
download | linux-a5a81f0b9025867efb999d14a8dfc1907c5a4c3b.tar.bz2 |
ipv6: Fix default route failover when CONFIG_IPV6_ROUTER_PREF=n
I believe this commit from 2008 was incorrect:
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=398bcbebb6f721ac308df1e3d658c0029bb74503
When CONFIG_IPV6_ROUTER_PREF is disabled, the kernel should follow
RFC4861 section 6.3.6: if no route is NUD_VALID, then traffic should be
sprayed across all routers (indirectly triggering NUD) until one of them
becomes NUD_VALID.
However, the following experiment demonstrates that this does not work:
1) Connect to an IPv6 network.
2) Change the router's MAC (and link-local) address.
The kernel will lock onto the first router and never try the new one, even
if the first becomes unreachable. This patch fixes the problem by
allowing rt6_check_neigh() to return 0; if all routers return 0, then
rt6_select() will fall back to round-robin behavior.
This patch should have no effect when CONFIG_IPV6_ROUTER_PREF=y.
Note that rt6_check_neigh() is only used in a boolean context, so I've
changed its return type accordingly.
Signed-off-by: Paul Marks <pmarks@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'init')
0 files changed, 0 insertions, 0 deletions