This reverts commit 81100eb80a for the
release, to avoid the unnecessary warning noise that is only really
relevant to wireless driver developers.
The warning will probably go right back in after I cut the release, but
at least we won't unnecessarily worry users.
Acked-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch makes mac80211 warn (once) when the driver passes up a
frame in which the payload data is not aligned on a four-byte
boundary, with a long comment for people who run into the condition
and need to know what to do.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This patch fixes a regression I (most likely) introduced, namely that
unencrypted frames are right now accepted even if we have a key for that
specific sender. That has very bad security implications.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Make "decrypt failed" and "have no key" debugging messages compile
conditionally upon CONFIG_MAC80211_DEBUG. They have been useful for
finding certain problems in the past, but in many cases they just
clutter a user's logs.
A typical example is an enviornment where multiple SSIDs are using a
single BSSID but with different protection schemes or different keys
for each SSID. In such an environment these messages are just noise.
Let's just leave them for those interested enough to turn-on debugging.
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The decryption handlers will skip the frame if the RX_FLAG_DECRYPTED
flag is set, so the early flag setting introduced by Johannes breaks
decryption. To work around this, call the handlers first and then set
the flag.
Signed-off-by: Mattias Nissler <mattias.nissler@gmx.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This "algorithm" is used only internally and is not useful.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Michael Buesch <mb@bu3sch.de>
Acked-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This makes mac80211 set the RX_FLAG_DECRYPTED flag for frames
decrypted in software allowing us to handle some things more
uniformly.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, we have three RX handlers doing the decryption.
This patch changes it to have only one handler doing
everything, thereby getting rid of many duplicate checks.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
--
net/mac80211/rx.c | 46 ++++++++++++----------------------------------
1 files changed, 12 insertions(+), 34 deletions(-)
This moves the sta_process RX handler to after decryption
so that frames that cannot be decrypted don't influence
statistics, it is likely that they were injected or something
else is totally wrong.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Removes the management interface since it is only required
for hostapd/userspace MLME, will not be in the final tree
at least in this form and hostapd/userspace MLME currently
do not work against this tree anyway.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since I cannot convince the lazy driver authors (hello Michael)
to stop (ab)using the MGMT interface type internally in their
drivers, this patch introduces a new _INVALID type especially
for their use and changes all affected drivers to use it.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When we update the counters iff_promiscs and iff_allmultis
in struct ieee80211_local we have no common lock held to
protect them. The problem is that the update to each counter
may not be atomic, so we could end up with iff_promiscs == -1
in unfortunate conditions. To fix it, use atomic_t values.
It doesn't matter whether the two counters are updated
together atomically or not, if there are two invocations
of set_multicast_list we will end up with multiple
configure_filter() invocations of which the latter will always
be correct.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
VLAN interfaces have yet another bug: they aren't accounted
for properly in the receive path in prepare_for_handlers().
I noticed this by code inspection, but it would be easy for
the compiler to catch such things if we'd just use the proper
enum where appropriate.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Currently, we run through all three crypto algorithms for each
received frame even though we have previously determined which
key we have and as such already know which algorithm will be
used. Change it to invoke only the needed function. Also move
the WEP decrypt handler to wep.c so that fewer functions need
to be non-static.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This makes mac80211 pass all frames to monitor interfaces early
before all receive processing with the benefit that only a single
copy needs to be made, all monitors can receive clones of the skb
and if the frame will be discarded we don't even need to make a
single copy.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Florian Lohoff noticed a bug in mac80211: when bringing the
master interface down while other virtual interfaces are up
we call dev_close() under a spinlock which is not allowed.
This patch removes the sub_if_lock used by mac80211 in favour
of using an RCU list. All list manipulations are already done
under rtnl so are well protected against each other, and the
read-side locks we took in the RX and TX code are already in
RCU read-side critical sections.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Florian Lohoff <flo@rfc822.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Cc: Satyam Sharma <satyam@infradead.org>
Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Drivers are currently supposed to keep track of monitor
interfaces if they allow so-called "hard" monitor, and
they are also supposed to keep track of multicast etc.
This patch changes that, replaces the set_multicast_list()
callback with a new configure_filter() callback that takes
filter flags (FIF_*) instead of interface flags (IFF_*).
For a driver, this means it should open the filter as much
as necessary to get all frames requested by the filter flags.
Accordingly, the filter flags are named "positively", e.g.
FIF_ALLMULTI.
Multicast filtering is a bit special in that drivers that
have no multicast address filters need to allow multicast
frames through when either the FIF_ALLMULTI flag is set or
when the mc_count value is positive.
At the same time, drivers are no longer notified about
monitor interfaces at all, this means they now need to
implement the start() and stop() callbacks and the new
change_filter_flags() callback. Also, the start()/stop()
ordering changed, start() is now called *before* any
add_interface() as it really should be, and stop() after
any remove_interface().
The patch also changes the behaviour of setting the bssid
to multicast for scanning when IEEE80211_HW_NO_PROBE_FILTERING
is set; the IEEE80211_HW_NO_PROBE_FILTERING flag is removed
and the filter flag FIF_BCN_PRBRESP_PROMISC introduced.
This is a lot more efficient for hardware like b43 that
supports it and other hardware can still set the BSSID
to all-ones.
Driver modifications by Johannes Berg (b43 & iwlwifi), Michael Wu
(rtl8187, adm8211, and p54), Larry Finger (b43legacy), and
Ivo van Doorn (rt2x00).
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This makes mac80211 print out the wiphy name instead of the
master device name where appropriate.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch removes the key threshold stuff from mac80211.
I have patches for later that add it as a per-key setting
to nl/cfg80211.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch allows drivers to indicate bad FCS/PLCP CRC to the stack and
have the stack drop packets like that except for monitor interfaces.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are a few TODO comments in the mac80211 sources regarding
hardware offload for Michael MIC verification. Those items are,
however, better handled in the driver instead of the stack, if
any device requires such hand-holding.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stats are now available for device usage inside network_device
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch reworks the various hardware crypto related
flags to make them more local, i.e. put them with each
key or each packet instead of into the hw struct.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch removes all mention of the atheros turbo modes that
can't possibly work properly anyway since in some places we don't
check for them when we should.
I have no idea what the iwlwifi drivers were doing with these but
it can't possibly have been correct.
Cc: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
During receive processing, we select the key long before using it and
because there's no locking it is possible that we kfree() the key
after having selected it but before using it for crypto operations.
Obviously, this is bad.
Secondly, during transmit processing, there are two possible races: We
have a similar race between select_key() and using it for encryption,
but we also have a race here between select_key() and hardware
encryption (both when a key is removed.)
This patch solves these issues by using RCU: when a key is to be freed,
we first remove the pointer from the appropriate places (sdata->keys,
sdata->default_key, sta->key) using rcu_assign_pointer() and then
synchronize_rcu(). Then, we can safely kfree() the key and remove it
from the hardware. There's a window here where the hardware may still
be using it for decryption, but we can't work around that without having
two hardware callbacks, one to disable the key for RX and one to disable
it for TX; but the worst thing that will happen is that we receive a
packet decrypted that we don't find a key for any more and then drop it.
When we add a key, we first need to upload it to the hardware and then,
using rcu_assign_pointer() again, link it into our structures.
In the code using keys (TX/RX paths) we use rcu_dereference() to get the
key and enclose the whole tx/rx section in a rcu_read_lock() ...
rcu_read_unlock() block. Because we've uploaded the key to hardware
before linking it into internal structures, we can guarantee that it is
valid once get to into tx().
One possible race condition remains, however: when we have hardware
acceleration enabled and the driver shuts down the queues, we end up
queueing the frame. If now somebody removes the key, the key will be
removed from hwaccel and then then driver will be asked to encrypt the
frame with a key index that has been removed. Hence, drivers will need
to be aware that the hw_key_index they are passed might not be under
all circumstances. Most drivers will, however, simply ignore that
condition and encrypt the frame with the selected key anyway, this
only results in a frame being encrypted with a wrong key or dropped
(rightfully) because the key was not valid. There isn't much we can
do about it unless we want to walk the pending frame queue every time
a key is removed and remove all frames that used it.
This race condition, however, will most likely be solved once we add
multiqueue support to mac80211 because then frames will be queued
further up the stack instead of after being processed.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The sta_info.assoc_ap value is used as a flag, move it
into flags.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When I changed the code there I forgot to mention what happens
with multicast frames in a regular BSS and keep wondering myself
if the code is correct. Add appropriate comments.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In STA mode, the AP will echo our traffic. This includes multicast
traffic.
Receiving these frames confuses some protocols and applications,
notably IPv6 Duplicate Address Detection.
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current version of wireless statistics contains a bug in the averaging
that makes the numbers be too sticky and not react to small changes. This
patch removes all averaging.
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Jiri Benc <jbenc@suse.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This moves all the key handling code out from ieee80211_ioctl.c
into key.c and also does the following changes including documentation
updates in mac80211.h:
1) Turn off hardware acceleration for keys when the interface
is down. This is necessary because otherwise monitor
interfaces could be decrypting frames for other interfaces
that are down at the moment. Also, it should go some way
towards better suspend/resume support, in any case the
routines used here could be used for that as well.
Additionally, this makes the driver interface nicer, keys
for a specific local MAC address are only ever present
while an interface with that MAC address is enabled.
2) Change driver set_key() callback interface to allow only
return values of -ENOSPC, -EOPNOTSUPP and 0, warn on all
other return values. This allows debugging the stack when
a driver notices it's handed a key while it is down.
3) Invert the flag meaning to KEY_FLAG_UPLOADED_TO_HARDWARE.
4) Remove REMOVE_ALL_KEYS command as it isn't used nor do we
want to use it, we'll use DISABLE_KEY for each key. It is
hard to use REMOVE_ALL_KEYS because we can handle multiple
virtual interfaces with different key configuration, so we'd
have to keep track of a lot of state for this and that isn't
worth it.
5) Warn when disabling a key fails, it musn't.
6) Remove IEEE80211_HW_NO_TKIP_WMM_HWACCEL in favour of per-key
IEEE80211_KEY_FLAG_WMM_STA to let driver sort it out itself.
7) Tell driver that a (non-WEP) key is used only for transmission
by using an all-zeroes station MAC address when configuring.
8) Change the set_key() callback to have access to the local MAC
address the key is being added for.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch embeds the struct ieee80211_key_conf into struct ieee80211_key
and thus avoids allocations and having data present twice.
This required some more changes:
1) The removal of the IEEE80211_KEY_DEFAULT_TX_KEY key flag.
This flag isn't used by drivers nor should it be since
we have a set_key_idx() callback. Maybe that callback needs
to be extended to include the key conf, but only a driver that
requires it will tell.
2) The removal of the IEEE80211_KEY_DEFAULT_WEP_ONLY key flag.
This flag is global, so it shouldn't be passed in the key
conf structure. Pass it to the function instead.
Also, this patch removes the AID parameter to the set_key() callback
because it is currently unused and the hardware currently cannot know
about the AID anyway. I suspect this was used with some hardware that
actually selected the AID itself, but that functionality was removed.
Additionally, I've removed the ALG_NULL key algorithm since we have
ALG_NONE.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
mac80211, remove bitfields from struct ieee80211_sub_if_data
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
mac80211, remove bitfields from struct ieee80211_txrx_data
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
remove bitfields from struct ieee80211_tx_packet_data
[Johannes: completely clear flags in ieee80211_remove_tx_extra]
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Create a new file event.c that will contain code to send mac/mlme
events to userspace. For now put the Michael MIC failure condition
into it and remove sending of that condition via the management
interface, hostapd interestingly doesn't do anything when it gets
such a packet besides printing a message, it reacts only on the
private iwevent.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When doing key selection for software decryption, mac80211 gets
a few things wrong: it always uses pairwise keys if configured,
even if the frame is addressed to a multicast address. Also, it
doesn't allow using a key index of zero if a pairwise key has
also been found.
This patch changes the key selection code to be (more) in line
with the 802.11 specification. I have confirmed that with this,
multicast frames are correctly decrypted and I've tested with
WEP as well.
While at it, I've cleaned up the semantics of the hardware flags
IEEE80211_HW_WEP_INCLUDE_IV and IEEE80211_HW_DEVICE_HIDES_WEP
and clarified them in the mac80211.h header; it is also now
allowed to set the IEEE80211_HW_DEVICE_HIDES_WEP option even if
it only applies to frames that have been decrypted by the hw,
unencrypted frames must be dropped but encrypted frames that
the hardware couldn't handle can be passed up unmodified.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Neither hostapd nor wpa_supplicant really use it.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Many if not all of these messages can be triggered by sending
a few rogue frames which is trivially done and then we overflow
our logs.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
David Woodhouse noticed that under some circumstances the number of slab
allocations kept growing. After looking a bit, this seemed to happen
when you had a management mode interface that was *down*.
The reason for this is that when the device is down, all management
frames get queued to the in-kernel MLME (via ieee80211_sta_rx_mgmt) but
then the sta work is invoked but doesn't run when the netif is down.
When you then bring the interface up, all such frames are freed, but if
you change the mode all of them are lost because the skb queue is
reinitialised as soon as you go back to managed mode. The skb queue is
correctly cleared when the interface is brought down, but the code
doesn't account for the fact that it may be filled while it is not up.
This patch should fix the issue by simply ignoring all interfaces that
are down when going through the RX handlers.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some more outdenting to make the code more readable.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Jiri Benc <jbenc@suse.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
pre_rx handlers can't really touch sta since for IBSS it might not be
assigned yet, it can create sta info structs on-the-fly.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Jiri Benc <jbenc@suse.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The really indented part that does the huge switch on the interface
type is a nuisance. Put it into an own function 'prepare_for_handlers'.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Jiri Benc <jbenc@suse.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The ieee80211_rx_h_check handler really does two things, it's
a lot easier to understand if it's split into ieee80211_rx_h_check
and ieee80211_rx_h_load_key, and it may be possible in the future
to optimise the key loading to not do it for each interface.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Jiri Benc <jbenc@suse.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Make some really indented code more readable by outdenting.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Jiri Benc <jbenc@suse.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This patch moves the QoS handlers into rx.c making it possible
to compile wme.c only when NET_SCHED is defined.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Jiri Benc <jbenc@suse.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Jiri Benc <jbenc@suse.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>