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author | Su, Xuemin <suxm@chinanetcenter.com> | 2016-06-13 11:02:50 +0800 |
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committer | David S. Miller <davem@davemloft.net> | 2016-06-14 17:23:09 -0400 |
commit | d1e37288c9146dccff830e3253e403af8705b51f (patch) | |
tree | 573ea16d2781cf3754df56de05a306f8fff17c88 /drivers/net/geneve.c | |
parent | 6c0d54f1897d229748d4f41ef919078db6db2123 (diff) | |
download | linux-d1e37288c9146dccff830e3253e403af8705b51f.tar.bz2 |
udp reuseport: fix packet of same flow hashed to different socket
There is a corner case in which udp packets belonging to a same
flow are hashed to different socket when hslot->count changes from 10
to 11:
1) When hslot->count <= 10, __udp_lib_lookup() searches udp_table->hash,
and always passes 'daddr' to udp_ehashfn().
2) When hslot->count > 10, __udp_lib_lookup() searches udp_table->hash2,
but may pass 'INADDR_ANY' to udp_ehashfn() if the sockets are bound to
INADDR_ANY instead of some specific addr.
That means when hslot->count changes from 10 to 11, the hash calculated by
udp_ehashfn() is also changed, and the udp packets belonging to a same
flow will be hashed to different socket.
This is easily reproduced:
1) Create 10 udp sockets and bind all of them to 0.0.0.0:40000.
2) From the same host send udp packets to 127.0.0.1:40000, record the
socket index which receives the packets.
3) Create 1 more udp socket and bind it to 0.0.0.0:44096. The number 44096
is 40000 + UDP_HASH_SIZE(4096), this makes the new socket put into the
same hslot as the aformentioned 10 sockets, and makes the hslot->count
change from 10 to 11.
4) From the same host send udp packets to 127.0.0.1:40000, and the socket
index which receives the packets will be different from the one received
in step 2.
This should not happen as the socket bound to 0.0.0.0:44096 should not
change the behavior of the sockets bound to 0.0.0.0:40000.
It's the same case for IPv6, and this patch also fixes that.
Signed-off-by: Su, Xuemin <suxm@chinanetcenter.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/geneve.c')
0 files changed, 0 insertions, 0 deletions