Today I hit one of my new WARN_ONs in the mac80211 code because
a key wasn't being freed correctly. After wondering for a while
I finally tracked it to the fact that STA keys aren't added to
the per-sdata key list correctly, they are supposed to always be
on that list, not just for default keys. This patch fixes that.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
I noticed a bug I introduced when mesh is enabled: sta_info_destroy()
will end up calling cancel_timer() on a timer that has never been
initialized because the timer is only initialized in mesh_plink_alloc(),
not in sta_info_alloc(). This patch moves the initialization of all mesh
related fields into sta_info_alloc(), adds a bit of sanity checking to
the cfg80211 handlers and sta_info_insert() and makes mesh_plink_alloc()
a static helper function that is only used from the mesh plink code.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Quite a while ago I started this book. The required kernel-doc
patches have since gone into the tree so it is now possible to
build the book in mainline.
The actual documentation is still rather incomplete and not all
things are linked into the book, but this enables us to edit
the documentation collaboratively, hopefully driver authors can
add documentation based on their experience with mac80211.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Luis pointed out that this path is going to be freed right
away anyway so there's no point in assigning next_hop.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When we take down an interface, we need to remove the STA info
items that belong to it because otherwise we might invoke a
sta_notify() callback in the driver when we later delete the
STA entries, but in that case the driver will already have
removed its knowledge of the interface they belonged to leading
to confusion. Also, we could invoke the set_tim() callback after
the driver removed its knowledge of the interface, which can
lead to a crash if it requests a beacon with a then-invalid vif
pointer!
A side effect of this patch is that, because it was easier, it
disallows changing the WDS peer while an interface is up. Should
that actually be necessary, it can be added back, but the WDS
peer STA entry may not be added while the interface is UP so for
now I've simplified the WDS peer's STA entry lifetime management.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This patch cleans up the sta_info struct and documents how
each set of variables is locked. Notably, flags locking is
completely missing. It also adds kernel-doc for some (but
not all yet) members of the struct.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
sta_info_add() has two functions: allocating a station info
structure and inserting it into the hash table/list. Splitting
these two functions allows allocating with GFP_KERNEL in many
places instead of GFP_ATOMIC which is now required by the RCU
protection. Additionally, in many places RCU protection is now
no longer needed at all because between sta_info_alloc() and
sta_info_insert() the caller owns the structure.
This fixes a few race conditions with setting initial flags
and similar, but not all (see comments in ieee80211_sta.c and
cfg.c). More documentation on the existing races will be in
a follow-up patch.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This makes access to the STA hash table/list use RCU to protect
against freeing of items. However, it's not a true RCU, the
copy step is missing: whenever somebody changes a STA item it
is simply updated. This is an existing race condition that is
now somewhat understandable.
This patch also fixes the race key freeing vs. STA destruction
by making sure that sta_info_destroy() is always called under
RTNL and frees the key.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Split it into ieee80211_tx_data and ieee80211_rx_data to clarify
usage/flag usage and remove the stupid union thing.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Three __le16s followed by an enum (int) leave a two-byte hole
of padding which we can use for two of the other fields.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Accidentally copied in a __mesh_plink_deactivate, noticed by Luis
Carlos Cobo.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Moves another ifdef into the sta_info header file in favour of
compiling more code even w/o CONFIG_MAC80211_MESH.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This needs to be exported because rate control algorithms
can be modular.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This clarifies that the mesh networking code is currently
based on Draft 1.08 of the 802.11 Mesh Networking amendment.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This inserts a missing break statement which, if hit, would cause
the code to fall-through and unlock a spinlock twice. Noticed via
sparse's "lock count wrong in basic block" warning and careful
code inspection.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Currently marked BROKEN because of endianness problems.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This fixes missing unlocks noticed by sparse.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Various cleanups, reducing the #ifdef mess and other things.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This completes the mesh interface handling code and a few other
bits about the mac80211 module.
Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This adds code to allow adding mesh interfaces and configuring
mesh peers etc. Also, it adds code for station dumping.
Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This patch contains the debugfs code for mesh statistics and configuration
parameters. Please note that generic support for r/w debugfs attributes has been
added.
Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This file implements the on-demand Hybrid Wireless Mesh Protocol, at this moment
using hop-count as the metric. When no mesh path exists for a given destination
or the mesh path is not active, frames addressed to that destination will be
queued and a Path Request frame will be sent. Queued frames will be sent when
the path is resolved (usually after reception of a Path Response) or discarded
if discovery times out. Path Requests will also be sent to refresh paths that
are being used and are close to expiring.
Path Errors are sent when a path discovery process triggered by the attempt to
forward a frame originated in a different mesh point times out. Path Errors are
also sent when a peer link is determined to be unreachable because of high error
rates.
Multiple destination support in Path Requests and Path Errors and precursors
have not been implemented yet.
Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The mesh path table associates destinations with the next hop to reach them. The
table is a hash of linked lists protected by rcu mechanisms. Every mesh path
contains a lock to protect the mesh path state.
Each outgoing mesh frame requires a look up into this table. Therefore, the
table it has been designed so it is not necessary to hold any lock to find the
appropriate next hop.
If the path is determined to be active within a rcu context we can safely
dereference mpath->next_hop->addr, since it holds a reference to the sta
next_hop. After a mesh path has been set active for the first time it next_hop
must always point to a valid sta. If this is not possible the mpath must be
deleted or replaced in a RCU safe fashion.
Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This file implements mesh discovery and peer link establishment support using
the mesh peer link table provided in mesh_plinktbl.c.
Secure peer links have not been implemented yet.
Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This includes support for mesh network scanning. The ugly code in
ieee80211_sta_scan_result() is my approach to work around wext. This has been
tested with wireless tools version 29 and works as expected (the new interface
mode is just not shown).
Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Includes integration in struct sta_info of mesh peer link elements, previously
on their own mesh peer link table.
Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This changes the TX/RX paths in mac80211 to support mesh interfaces.
This code will be cleaned up later again before being enabled.
Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The two important features coded in mesh.c are:
Recently Multicast Cache: in on-demand HWMP, multicast traffic is retransmitted
by every receiving node. Even though a mesh TTL counter avoids infinite loops,
it is also necessary to avoid traffic explosion by keeping a cache of multicast
mesh frame that have been received recently. With this feature, maximum number
of retransmissions of a multicast frame for the case of N nodes within the range
of each other would be N. Without it, the maximum number of retransmissions
would be in the order of N^(MESH_TTL - 1).
Code to support mesh tables.
Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Added support for mesh id and mesh path operation as well as
station structure dumping.
Signed-off-by: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Even though I thought about it a lot and had also tested it, some
of my recent changes in the key code broke replacing keys, making
the kernel oops because a key is removed from a list while not on
it.
This patch fixes that using the list as an indication whether or
not the key is on it (an empty list means it's not on any list.)
Also, this patch fixes hw accel enabling, the check for not doing
hw accel when the interface is down was lost and is restored by
this.
Additionally, move adding the key to the list into the function
__ieee80211_key_replace() for more consistency.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
In order to RCU-ify sta_info, we need to be able to allocate
a key without linking it to an sdata/sta structure (because
allocation cannot be done in an rcu critical section). This
patch splits up ieee80211_key_alloc() and updates all users
appropriately.
While at it, this patch fixes a number of race conditions
such as finally making key replacement atomic, unfortunately
at the expense of more complex code.
Note that this patch documents /existing/ bugs with sta info
and key interaction, there is currently a race condition
when a sta info is freed without holding the RTNL. This will
finally be fixed by a followup patch.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
These things aren't used and the only possible use is within
rate control algorithms, however those can, if they need it,
keep track of it in their private data. last_ack_ms isn't
even updated so completely useless.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
If ieee80211_if_reinit() is called from ieee80211_unregister_hw()
then it is possible that the driver will still request a beacon
(it is allowed to until ieee80211_unregister_hw() has returned.)
This means we need to use an RCU-protected write to the beacon
information even in this function.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This patch fixes two errors introduced by
commit 19d35612f3cd7f60dd9174c0100584e21f5a1025
Author: Bruno Randolf <bruno@thinktube.com>
Date: Mon Feb 18 11:21:36 2008 +0900
mac80211: enable IBSS merging
The first error is an endianness problem that sparse found and
the second is a build failure when CONFIG_MAC80211_IBSS_DEBUG
is not set.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Bruno Randolf <bruno@thinktube.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When print_mac() was marked as __pure to avoid emitting a function
call in pr_debug() scenarios, a warning in this code surfaced since
it relies on the fact that the buffer is modified and doesn't use
the return value. This patch makes it use the return value instead.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Reported-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Disallow having more than one IBSS interface up at any time
because of beacon distribution issues, and for now also disallow
having more than one IBSS/STA interface up at the same time
because we use the master interface's BSS struct which would
be completely corrupted when we have more than one up.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When a STA structure is added, it is often checked whether it
already exists before adding it. This, however, isn't done
atomically so there is a race condition that could lead to two
STA structures being added with the same MAC address. This
patch changes sta_info_add() to return an ERR_PTR in case
of failure and adds the failure mode -EEXIST when the STA
already exists.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Luis Carlos Cobo <luisca@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This reworks the code for TX filtered frames, splitting it out to
a new function to handle those cases, making the clear instruction
a flag and renaming a few things to be easier to understand and
less Atheros hardware specific. Finally, it also makes the comments
explain more.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Configuration variables are only available to the preprocessor
Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This consolidates all TIM handling code to avoid re-introducing
errors with the bitmap/set_tim order and to reduce code. While
reading the code I noticed a possible problem so I also added
a comment about that.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The TIM flag that is kept in each station's info is completely
useless, there's no code (aside from the debugfs display code)
checking it, hence it can be removed. While doing that, I noticed
that the TIM handling is broken when buffered frames expire, so
fix that.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Drivers should be allowed to simply get a complete new beacon when
set_tim() is invoked (and set_tim() is required for drivers that
just want a beacon template!), so we need to update our own TIM
bitmap before calling set_tim() so that getting the beacon will
now get an already updated beacon.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This doesn't really need to be a full int variable since it's
just a flag to indicate a PS-poll is in progress.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
enable IBSS cell merging. if an IBSS beacon with the same channel, same ESSID
and a TSF higher than the local TSF (mactime) is received, we have to join its
BSSID. while this might not be immediately apparent from reading the 802.11
standard it is compliant and necessary to make IBSS mode functional in many
cases. most drivers have a similar behaviour.
* move the relevant code section (previously only containing debug code) down
to the end of the function, so we can reuse the bss structure.
* we have to compare the mactime (TSF at the time of packet receive) rather
than the current TSF. since mactime is defined as the time the first data
symbol arrived we add the time until byte 24 where the timestamp resides, since
this is how the beacon timestamp is defined. as some some drivers are not able
to give a reliable mactime we fall back to use the current TSF, which will be
enough to catch most (but not all) cases where an IBSS merge is necessary.
* in IBSS mode we want to allow beacons to override probe response info so we
can correctly do merges.
* we don't only configure beacons based on scan results, so change that
message.
* to enable this we have to let all beacons thru in IBSS mode, even if they
have a different BSSID.
Signed-off-by: Bruno Randolf <bruno@thinktube.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
this moves ieee80211_sta_join_ibss() up for the next patch (ibss merge).
Signed-off-by: Bruno Randolf <bruno@thinktube.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The functions time_before, time_before_eq, time_after, and time_after_eq are more robust for comparing jiffies against other values.
So following patch implements usage of the time_after() macro, defined at linux/jiffies.h, which deals with wrapping correctly
Cc: linux-wireless@vger.kernel.org
Signed-off-by: S.Çağlar Onur <caglar@pardus.org.tr>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This brain-damaged code just bothers me, fix it.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
