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| author | Johannes Berg <johannes.berg@intel.com> | 2016-02-04 13:31:17 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-02-11 04:27:35 -0500 |
| commit | 12b74dfadb5a7a23baf4db941dc9fd9d371f249a (patch) | |
| tree | 40009e4d2e0eb925967d1ffde4f0c3b415f47ee3 /Documentation | |
| parent | ccad0993567812e88617f105c01b04f1528538b6 (diff) | |
| download | linux-12b74dfadb5a7a23baf4db941dc9fd9d371f249a.tar.bz2 | |
ipv4: add option to drop unicast encapsulated in L2 multicast
In order to solve a problem with 802.11, the so-called hole-196 attack,
add an option (sysctl) called "drop_unicast_in_l2_multicast" which, if
enabled, causes the stack to drop IPv4 unicast packets encapsulated in
link-layer multi- or broadcast frames. Such frames can (as an attack)
be created by any member of the same wireless network and transmitted
as valid encrypted frames since the symmetric key for broadcast frames
is shared between all stations.
Additionally, enabling this option provides compliance with a SHOULD
clause of RFC 1122.
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/networking/ip-sysctl.txt | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 73b36d7c7b0d..d5910d63214d 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -1216,6 +1216,13 @@ promote_secondaries - BOOLEAN promote a corresponding secondary IP address instead of removing all the corresponding secondary IP addresses. +drop_unicast_in_l2_multicast - BOOLEAN + Drop any unicast IP packets that are received in link-layer + multicast (or broadcast) frames. + This behavior (for multicast) is actually a SHOULD in RFC + 1122, but is disabled by default for compatibility reasons. + Default: off (0) + tag - INTEGER Allows you to write a number, which can be used as required. |