This patch fixes the problem of dropping RANN element if the TTL
is 1. If the received RANN element TTL is 1 or greater than 1, the
RANN is processed. However, forwarding of received RANN element
with TTL 1 or less is prohibited according to the standard. This
is previously reported by Monthadar Al Jaberi.

Besides, this patch also avoid the processing of unicast PREQ
generation if the RANN element does not meet the acceptance
criteria mentioned in Sec. 13.10.12.4.2 of IEEE Std. 802.11-2012.
Reported-by: NMonthadar Al Jaberi <monthadar@gmail.com>
Signed-off-by: NChun-Yeow Yeoh <yeohchunyeow@gmail.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

As defined in section 13.10.9.3 Case D (802.11-2012), this
control variable is used to limit the mesh STA to send only
one PREQ to a root mesh STA within this interval of time
(in TUs). The default value for this variable is set to
2000 TUs. However, for current implementation, the maximum
configurable of dot11MeshHWMPconfirmationInterval is
restricted by dot11MeshHWMPactivePathTimeout.
Signed-off-by: NChun-Yeow Yeoh <yeohchunyeow@gmail.com>
[line-break commit log]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Generate the proactive PREP element in Proactive PREQ mode as
defined in Sec. 13.10.10.3 (Case D) of IEEE Std. 802.11-2012.
Signed-off-by: NChun-Yeow Yeoh <yeohchunyeow@gmail.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Generate the proactive PREQ element as defined in
Sec. 13.10.9.3 (Case C) of IEEE Std. 802.11-2012
based on the selection of dot11MeshHWMPRootMode as follow:
dot11MeshHWMPRootMode (2) is proactivePREQnoPREP
dot11MeshHWMPRootMode (3) is proactivePREQwithPREP

The proactive PREQ is generated based on the interval
defined by dot11MeshHWMProotInterval.

With this change, proactive RANN element is now generated
if the dot11MeshHWMPRootMode is set to (4) instead of (1).
Signed-off-by: NChun-Yeow Yeoh <yeohchunyeow@gmail.com>
[line-break commit log]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Signed-off-by: NJavier Cardona <javier@cozybit.com>
Reviewed-by: NJason Abele <jason@cozybit.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Signed-off-by: NJavier Cardona <javier@cozybit.com>
Reviewed-by: NJason Abele <jason@cozybit.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Standardize the debugging to be able to use dynamic_debug.

Coalesce formats, align arguments.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Forwarded PREQ is either unicast or multicast. The appropriate counters
should be incremented accordingly.
Signed-off-by: NChun-Yeow Yeoh <yeohchunyeow@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Use the new bool function ether_addr_equal to add
some clarity and reduce the likelihood for misuse
of compare_ether_addr for sorting.

Done via cocci script:

$ cat compare_ether_addr.cocci
@@
expression a,b;
@@
-	!compare_ether_addr(a, b)
+	ether_addr_equal(a, b)

@@
expression a,b;
@@
-	compare_ether_addr(a, b)
+	!ether_addr_equal(a, b)

@@
expression a,b;
@@
-	!ether_addr_equal(a, b) == 0
+	ether_addr_equal(a, b)

@@
expression a,b;
@@
-	!ether_addr_equal(a, b) != 0
+	!ether_addr_equal(a, b)

@@
expression a,b;
@@
-	ether_addr_equal(a, b) == 0
+	!ether_addr_equal(a, b)

@@
expression a,b;
@@
-	ether_addr_equal(a, b) != 0
+	ether_addr_equal(a, b)

@@
expression a,b;
@@
-	!!ether_addr_equal(a, b)
+	ether_addr_equal(a, b)
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Record the RANN sender's address only for RANNs that meet the acceptance
criteria (per sections 13.10.12.4.2).
Signed-off-by: NChun-Yeow Yeoh <yeohchunyeow@gmail.com>
Reviewed-by: NJavier Cardona <javier@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This patch is intended to solve the follwing issues in RANN propagation:
[1] The interval in propagated RANN should be based on the interval of received RANN.
[2] The aggregated path metric for propagated RANN is as received plus own link metric
    towards the transmitting mesh STA (not root mesh STA).
[3] The comparison of path metric for RANN with same sequence number should be done
    before deciding whether to propagate or not.
Signed-off-by: NChun-Yeow Yeoh <yeohchunyeow@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The HWMP sequence number of received RANN element is compared to decide whether to be
propagated. The sequence number is required to covert from 32bit little endian data into
CPUs endianness for comparison. The same applies to the RANN metric.
Signed-off-by: NChun-Yeow Yeoh <yeohchunyeow@gmail.com>
Signed-off-by: NJavier Cardona <javier@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Airtime link metric estimation was broken in HT mesh, use
cfg80211_calculate_bitrate to get the right rate value.

Also factor out tx rate copying from sta_set_sinfo().
Signed-off-by: NThomas Pedersen <thomas@cozybit.com>
Reviewed-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

RANN, PREP and PERR propagation should happen only if the
dot11MeshForwarding is true.  Besides, data frame should not be
forwarded if dot11MeshForwarding is false. This redundant checking
is necessary to avoid the broadcasted ARP breaking the non-forwarding
rule.
Signed-off-by: NChun-Yeow Yeoh <yeohchunyeow@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Because of the constant size and guaranteed 16 bit alignment, the inline
compare_ether_addr function is much cheaper than calling memcmp.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Acked-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

According to Section Y.7.4 Actions on receipt of proactive RANN, an individually
addressed PREQ should be generated towards the neighbor peer mesh STA indicated
in the RANN Sender Address field in the forwarding information.
Signed-off-by: NChun-Yeow Yeoh <yeohchunyeow@gmail.com>
Signed-off-by: NJavier Cardona <javier@cozybit.com>
Signed-off-by: NThomas Pedersen <thomas@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Some files implicitly get this via mesh.h
which itself doesn't need it, so move the
inclusion into the right files. Some other
files don't need it at all but include it,
so remove it from there.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

A mesh node that joins the mesh network is by default a forwarding entity. This patch allows
the mesh node to set as non-forwarding entity. Whenever dot11MeshForwarding is set to 0, the
mesh node can prevent itself from forwarding the traffic which is not destined to him.
Signed-off-by: NChun-Yeow Yeoh <yeohchunyeow@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Use local->tx_headroom instad of local->hw.extra_tx_headroom.
local->tx_headroom is the max of hw.extra_tx_headroom required by the
driver and the headroom required by mac80211 for status reporting.  On
drivers where hw.extra_tx_headroom is smaller than what mac80211
requires (e.g. ath5k), we would not reserve sufficient buffer space to
report tx status.

Also, don't reserve local->tx_headroom + local->hw.extra_tx_headroom.
Reported-by: NSimon Morgenthaler <s.morgenthaler@students.unibe.ch>
Reported-by: NKai Scharwies <kai@scharwies.de>
Signed-off-by: NJavier Cardona <javier@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We used to initiate a path discovery when receiving a frame for which
there is no forwarding information. To cut down on PREQ spam, just send
a (gated) PERR in response.

Also separate path discovery logic from nexthop querying. This patch
means we no longer queue frames when forwarding, so kill the PERR TX
stuff in discard_frame().
Signed-off-by: NThomas Pedersen <thomas@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

As per 802.11mb 13.9.11.3
Signed-off-by: NThomas Pedersen <thomas@cozybit.com>
Signed-off-by: NJavier Cardona <javier@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

HWMP originator and target addresses were switched on the air but also
on reception, which is why path selection still worked.
Signed-off-by: NThomas Pedersen <thomas@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Don't write the TA until next hop is actually known, since we might need
the original TA for sending a PERR. Previously we would send a PERR to
ourself if path resolution for a forwarded frame failed.
Signed-off-by: NThomas Pedersen <thomas@cozybit.com>
Signed-off-by: NJavier Cardona <javier@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

First time I tried smatch, and it says:
mesh_hwmp.c +870 mesh_queue_preq(21) error: double lock 'bottom_half:'
mesh_hwmp.c +873 mesh_queue_preq(24) error: double unlock 'bottom_half:'
mesh_hwmp.c +886 mesh_queue_preq(37) error: double unlock 'bottom_half:'

Which is indeed true -- there's no point in disabling BHs
again if we just did that a few lines earlier, so remove.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We recently introduced a return here, but we need to call kfree
first.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We only need to set the skb queue twice:

1. by the netdev, on local TX.
2. when forwarding a mesh frame.

We only need to set the qos header twice:

1. by mac80211, on local TX.
2. when putting a frame on the mpath->frame_queue

We also don't need the RA in order to set the proper queue mapping since
all mesh STAs are QoS, indicate this and do it once when the frame is
received. Also fixes an issue where the QoS header and queue mapping was not
set for unicast forwarded frames.
Signed-off-by: NJavier Cardona <javier@cozybit.com>
Signed-off-by: NThomas Pedersen <thomas@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Don't accept redundant PREQs for a given destination. This fixes a
problem under high load:

kernel: [20386.250913] mesh_queue_preq: 235 callbacks suppressed
kernel: [20386.253335] Mesh HWMP (mesh0): PREQ node queue full
kernel: [20386.253352] Mesh HWMP (mesh0): PREQ node queue full
(...)

The 802.11s protocol has a provision to limit the rate of path requests
(PREQs) are transmitted (dot11MeshHWMPpreqMinInterval) but there was no
limit on the rate at which PREQs were being queued up.  There is a valid
reason for queuing PREQs: this way we can even out PREQ bursts.  But
queueing multiple PREQs for the same destination is useless.
Reported-by: NPedro Larbig <pedro.larbig@carhs.de>
Signed-off-by: NJavier Cardona <javier@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Remove most references to magic numbers, save a few bytes and hopefully
improve readability.
Signed-off-by: NThomas Pedersen <thomas@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Mesh paths should only exist over established peer links.
Signed-off-by: NJavier Cardona <javier@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Per sec 7.1.3.5 of draft 12.0 of 802.11s, mesh frames indicate the
presence of the mesh control header in their QoS header.
Signed-off-by: NJavier Cardona <javier@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Under failure conditions, the mesh stack sends PERR messages to the
previous sender of the failed frame.  This happens in the tx feedback
path, in which the transmission queue lock may be taken.  Avoid a
deadlock by sending the path error via the pending queue.
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Allow userspace to set NL80211_MESHCONF_GATE_ANNOUNCEMENTS attribute,
which will advertise this mesh node as being a mesh gate.
NL80211_HWMP_ROOTMODE must be set or this will do nothing.
Signed-off-by: NJavier Cardona <javier@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Allow userspace to set Root Announcement Interval for our mesh
interface. Also, RANN interval is now in proper units of TUs.
Signed-off-by: NJavier Cardona <javier@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

In this implementation, a mesh gate is a root node with a certain bit
set in its RANN flags. The mpath to this root node is marked as a path
to a gate, and added to our list of known gates for this if_mesh. Once a
path discovery process fails, we forward the unresolved frames to a
known gate. Thanks to Luis Rodriguez for refactoring and bug fix help.
Signed-off-by: NJavier Cardona <javier@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

make hwmp_dbg print the relevant sdata->name by default and improve
formatting. Also add mpath_dbg macro for debugging of mesh path
operations.
Signed-off-by: NJavier Cardona <javier@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Make mesh path selection frames Mesh Action category, remove outdated
Mesh Path Selection category and defines, use updated reason codes, add
mesh_action_is_path_sel for readability, and update/correct path
selection IEs.
Signed-off-by: NThomas Pedersen <thomas@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When a PREQ or PREP is received from an intermediate node, it contains
useful information for path selection but it doesn't include the
originator's sequence number.   Therefore, when updating the mesh path
to that intermediate node, we should not set the MESH_PATH_SN_VALID
flag.  BUT, if the flag is set, it should not be unset as we might have
received a valid sequence number for that intermediate node in the past.

This issue was reported, fixed and tested by Ya Bo (游波) and Pedro
Larbig (ASPj).
Signed-off-by: NJavier Cardona <javier@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Make mesh_preq_queue_lock locking consistent with mesh_queue_preq() using
spin_lock_bh().
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NJavier Cardona <javier@cozybit.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

All these are instances of
  #define NAME value;
or
  #define NAME(params_opt) value;

These of course fail to build when used in contexts like
  if(foo $OP NAME)
  while(bar $OP NAME)
and may silently generate the wrong code in contexts such as
  foo = NAME + 1;    /* foo = value; + 1; */
  bar = NAME - 1;    /* bar = value; - 1; */
  baz = NAME & quux; /* baz = value; & quux; */

Reported on comp.lang.c,
Message-ID: <ab0d55fe-25e5-482b-811e-c475aa6065c3@c29g2000yqd.googlegroups.com>
Initial analysis of the dangers provided by Keith Thompson in that thread.

There are many more instances of more complicated macros having unnecessary
trailing semicolons, but this pile seems to be all of the cases of simple
values suffering from the problem. (Thus things that are likely to be found
in one of the contexts above, more complicated ones aren't.)
Signed-off-by: NPhil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

This adds sparse RCU annotations to most of
mac80211, only the mesh code remains to be
done.

Due the the previous patches, the annotations
are pretty simple. The only thing that this
actually changes is removing the RCU usage of
key->sta in debugfs since this pointer isn't
actually an RCU-managed pointer (it only has
a single assignment done before the key even
goes live). As that is otherwise harmless, I
decided to make it part of this patch.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>