linux.git/net/wireless/core.h, branch v2.6.32

cfg80211: sme: deauthenticate on assoc failure

2009-10-27T20:29:47+00:00

When the in-kernel SME gets an association failure from
the AP we don't deauthenticate, and thus get into a very
confused state which will lead to warnings later on. Fix
this by actually deauthenticating when the AP indicates
an association failure.

(Brought to you by the hacking session at Kernel Summit 2009 in Tokyo,
Japan. -- JWL)

Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville

cfg80211: clean up properly on interface type change

2009-08-28T18:40:31+00:00

When the interface type changes while connected, and the
driver does not require the interface to be down for a
type change, it is currently possible to get very strange
results unless the driver takes special care, which it
shouldn't have to.

To fix this, take care to disconnect/leave IBSS when
changing the interface type -- even if the driver may fail
the call. Also process all events that may be pending to
avoid running into a situation where an event is reported
but only processed after the type has already changed,
which would lead to missing events and warnings.

A side effect of this is that you will have disconnected
or left the IBSS even if the mode change ultimately fails,
but since the intention was to change it and thus leave or
disconnect, this is not a problem.

Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville

cfg80211: make spurious warnings less likely, configurable

2009-08-28T18:40:30+00:00

Bob reported that he got warnings in IBSS mode about
the ssid_len being zero on a joined event, but only
when kmemcheck was enabled. This appears to be due
to a race condition between drivers and userspace,
when the driver reports joined but the user in the
meantime decided to leave the IBSS again, the warning
would trigger. This was made more likely by kmemcheck
delaying the code that does the check and sends the
event.

So first, make the warning trigger closer to the
driver, which means it's not locked, but since only
the warning depends on it that's ok.

And secondly, users will not want to have spurious
warnings at all, so make those that are known to be
racy in such a way configurable.

Reported-by: Bob Copeland 
Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville

cfg80211: check lost scans later, fix bug

2009-08-28T18:40:25+00:00

When we lose a scan, cfg80211 tries to clean up after
the driver. However, it currently does this too early,
it does this in GOING_DOWN already instead of DOWN, so
it may happen with mac80211. Besides fixing this, also
make it more robust by leaking the scan request so if
the driver later actually finishes the scan, it won't
crash. Also check in ___cfg80211_scan_done whether a
scan request is still pending and exit if not.

Reported-by: Felix Fietkau 
Signed-off-by: Johannes Berg 
Tested-by: Felix Fietkau 
Signed-off-by: John W. Linville

cfg80211: fix dangling scan request checking

2009-08-20T15:36:05+00:00

My patch "cfg80211: fix deadlock" broke the code it
was supposed to fix, the scan request checking. But
it's not trivial to put it back the way it was, since
the original patch had a deadlock.

Now do it in a completely new way: queue the check
off to a work struct, where we can freely lock. But
that has some more complications, like needing to
wait for it to be done before the wiphy/rdev can be
destroyed, so some code is required to handle that.

Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville

cfg80211: check for and abort dangling scan requests

2009-08-14T13:14:07+00:00

If you trigger a scan request on an interface and then
take it down, or rmmod the module or unplug the device
the driver might "forget" to cancel the scan request.
That is a bug in the driver, but the current behaviour
is that we just hang endlessly waiting for the netdev
refcount to become 0 which it never will. To improve
robustness, check for this situation in cfg80211, warn
about it and clean up behind the driver. I don't just
clean up silently because it's likely that the driver
also has some internal state it has now leaked.

Additionally, this fixes a locking bug, clearing the
scan_req pointer should be done under the rdev lock.

Finally, we also need to _wait_ for the scan work and
not just abort it since it might be pending and wanting
to do a cleanup.

Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville

cfg80211: fix locking for SIWFREQ

2009-08-14T13:13:51+00:00

"cfg80211: validate channel settings across interfaces"
contained a locking bug -- in the managed-mode SIWFREQ
call it would end up running into a lock recursion.

This fixes it by not checking that particular interface
for a channel that it needs to stay on, which is as it
should be as that's the interface we're setting the
channel for.

Reported-by: Reinette Chatre 
Reported-by: Kalle Valo 
Signed-off-by: Johannes Berg 
Tested-by: Kalle Valo 
Tested-by: Reinette Chatre 
Signed-off-by: John W. Linville

nl80211: add generation number to all dumps

2009-08-14T13:13:43+00:00

In order for userspace to be able to figure out whether
it obtained a consistent snapshot of data or not when
using netlink dumps, we need to have a generation number
in each dump message that indicates whether the list has
changed or not -- its value is arbitrary.

This patch adds such a number to all dumps, this needs
some mac80211 involvement to keep track of a generation
number to start with when adding/removing mesh paths or
stations.

The wiphy and netdev lists can be fully handled within
cfg80211, of course, but generation numbers need to be
stored there as well.

Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville

cfg80211: use reassociation when possible

2009-08-14T13:13:43+00:00

With the move of everything related to the SME from
mac80211 to cfg80211, we lost the ability to send
reassociation frames. This adds them back, but only
for wireless extensions. With the userspace SME, it
shall control assoc vs. reassoc (it already can do
so with the nl80211 interface).

I haven't touched the connect() implementation, so
it is not possible to reassociate with the nl80211
connect primitive. I think that should be done with
the NL80211_CMD_ROAM command, but we'll have to see
how that can be handled in the future, especially
with fullmac chips.

This patch addresses only the immediate regression
we had in mac80211, which previously sent reassoc.

Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville

cfg80211: validate channel settings across interfaces

2009-08-14T13:13:42+00:00

Currently, there's a problem that affects regulatory
enforcement and connection stability, in that it is
possible to switch the channel while connected to a
network or joined to an IBSS.

The problem comes from the fact that we only validate
the channel against the current interface's type, not
against any other interface. Thus, you have any type
of interface up, additionally bring up a monitor mode
interface and switch the channel on the monitor. This
will obviously also switch the channel on the other
interface.

The problem now is that if you do that while sending
beacons for IBSS mode, you can switch to a disabled
channel or a channel that doesn't allow beaconing.
Combined with a managed mode interface connected to
an AP instead of an IBSS interface, you can easily
break the connection that way.

To fix this, this patch validates any channel change
with all available interfaces, and disallows such
changes on secondary interfaces if another interface
is connected to an AP or joined to an IBSS.

Signed-off-by: Johannes Berg 
Signed-off-by: John W. Linville