diff options
| author | Johan Almbladh <johan.almbladh@anyfinetworks.com> | 2021-06-28 15:32:46 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-09-18 14:40:28 +0300 |
| commit | 9713dfa5185ac06efa5998c61d4287d8306f60f4 (patch) | |
| tree | 7f60d36dfdd5c811c2aef4685ce8bc012ed519a9 /net/mac80211 | |
| parent | 83449db3aac0895147eac723bf23d0739720b968 (diff) | |
| download | linux-9713dfa5185ac06efa5998c61d4287d8306f60f4.tar.xz | |
mac80211: Fix monitor MTU limit so that A-MSDUs get through
[ Upstream commit 79f5962baea74ce1cd4e5949598944bff854b166 ]
The maximum MTU was set to 2304, which is the maximum MSDU size. While
this is valid for normal WLAN interfaces, it is too low for monitor
interfaces. A monitor interface may receive and inject MPDU frames, and
the maximum MPDU frame size is larger than 2304. The MPDU may also
contain an A-MSDU frame, in which case the size may be much larger than
the MTU limit. Since the maximum size of an A-MSDU depends on the PHY
mode of the transmitting STA, it is not possible to set an exact MTU
limit for a monitor interface. Now the maximum MTU for a monitor
interface is unrestricted.
Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Link: https://lore.kernel.org/r/20210628123246.2070558-1-johan.almbladh@anyfinetworks.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net/mac80211')
| -rw-r--r-- | net/mac80211/iface.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index 30589b4c09da..3a15ef8dd322 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -2000,9 +2000,16 @@ int ieee80211_if_add(struct ieee80211_local *local, const char *name, netdev_set_default_ethtool_ops(ndev, &ieee80211_ethtool_ops); - /* MTU range: 256 - 2304 */ + /* MTU range is normally 256 - 2304, where the upper limit is + * the maximum MSDU size. Monitor interfaces send and receive + * MPDU and A-MSDU frames which may be much larger so we do + * not impose an upper limit in that case. + */ ndev->min_mtu = 256; - ndev->max_mtu = local->hw.max_mtu; + if (type == NL80211_IFTYPE_MONITOR) + ndev->max_mtu = 0; + else + ndev->max_mtu = local->hw.max_mtu; ret = register_netdevice(ndev); if (ret) { |