When trying to add a new tt_local_entry, if such entry already exists, we have
to ensure that the TT_CLIENT_PENDING flag is not set, otherwise the entry will
be deleted soon.
Reported-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

In case of a client X roaming from a generic node A to another node B, it is
possible that a third node C gets A's OGM but not B's. At this point in time, if
C wants to send data to X it will send a unicast packet destined to A. The
packet header will contain A's last ttvn (C got A's OGM and so it knows it).

The packet will travel towards A without being intercepted because the ttvn
contained in its header is the newest for A.

Once A will receive the packet, A's state will not report to be in a "roaming
phase" (because, after a roaming, once A sends out its OGM, all the changes are
committed and the node is considered not to be in the roaming state anymore)
and it will match the ttvn carried by the packet. Therefore there is no reason
for A to try to alter the packet's route, thus dropping the packet because the
destination client is not there anymore.

However, C is well aware that it's routing information towards the client X is
outdated as it received an OGM from A saying that the client roamed away.
Thanks to this detail, this patch introduces a small change in behaviour: as
long as C is in the state of not knowing the new location of client X it will
forward the traffic to its last known location using ttvn-1 of the destination.
By using an older ttvn node A will be forced to re-route the packet.
Intermediate nodes are also allowed to update the packet's destination as long
as they have the information about the client's new location.
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

translation_table.{c,h} have been heavily modified by another contributor and
for legal purposes it is better to include his name into the contributor list
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

Before sending out a TT_Request packet we must convert the tt_crc field value
to network order (since it is 16bits long).
Reported-by: NAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

As the backbone gateways are connected to the same backbone, they
should announce the same clients on the backbone non-exclusively.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

as backbone gateways will all independently announce the same clients,
also the tt global table must be able to hold multiple originators per
client entry.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

Signed-off-by: NSven Eckelmann <sven@narfation.org>
Acked-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

Actually the TT_CLIENT_PENDING flag is never set in the tt_global_entry
structure, therefore this code is useless and can be removed.
Reported-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

Each tt_local_set_pending is always followed by a bat_dbg invocation. This can
be simplified by moving the bat_dbg() call.
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

In case of a new tt_local_entry, the TT_CLIENT_NEW flag has to be set before
adding such entry to the hash table. Otherwise, it opens a race condition
in which the entry can be found but the flag has not been set.
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

Signed-off-by: NSven Eckelmann <sven@narfation.org>
Acked-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

To increase readability the has_timed_out() functions has been introduced.
This patch converts existing time_after() calls to use this wrapper
function (if applicable).
This patch also converts all timeouts to miliseconds to be consistent.
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>

Both translation tables and network coding use timeouts to do house
keeping, so we might as well share the function used to compare a
timestamp+timeout with current time.

For readability and simplicity, the function is renamed to
has_timed_out() and uses time_is_before_jiffies() instead of
time_after().
Signed-off-by: NMartin Hundebøll <martin@hundeboll.net>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

All batman-adv packets have a common 3 byte header. It can be used to share
some code between different code paths, but it was never explicit stated that
this header has to be always the same for all packets. Therefore, new code
changes always have the problem that they may accidently introduce regressions
by moving some elements around.

A new structure is introduced that contains the common header and makes it
easier visible that these 3 bytes have to be the same for all on-wire packets.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

(ttvn == 0) is currently used as initial condition. However this is not a good
idea because ttvn gets the vale zero each time after reaching the maximum value
(wrap around). For this reason a new flag is added in order to define whether a
node has an initialised table or not. Moreover, after invoking
tt_global_del_orig(), tt_initialised has to be set to false
Reported-by: NAlexey Fisher <bug-track@fisher-privat.net>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Tested-by: NAlexey Fisher <bug-track@fisher-privat.net>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

I didn't resolve the merge properly during the last pull of the net
tree into net-next.

The code in the final resolution should set flags to TT_CLIENT_ROAM
not TT_CLIENT_PENDING.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When receiving a DEL change for a client due to a roaming event (change is
marked with TT_CLIENT_ROAM), each node  has to check if the client roamed
to itself or somewhere else.

In the latter case the global entry is kept to avoid having no route at all
otherwise we can safely delete the global entry
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

In case of a client roaming from node A to node B, the latter have to mark the
corresponding global entry with TT_CLIENT_ROAM (instead of TT_CLIENT_PENDING).

Marking a global entry with TT_CLIENT_PENDING will end up in keeping such entry
forever (because this flag is only meant to be used with local entries and it is
never checked on global ones).

In the worst case (all the clients roaming to the same node A) the local and the
global table will contain exactly the same clients. Batman-adv will continue to
work, but the memory usage is duplicated.
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

if hash_add() fails, we should remove the structure to avoid memory
leaks.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Acked-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

The tt_local_reset_flags() is actually used for one use case only. It is not
generalised enough to be used indifferent situations. This patch make it general
enough in order to let other code use it whenever a flag set is requested over
the whole hash table (passed as parameter). The function is now called
tt_set_flags()
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

Several functions in the translation table management code assume that the
tt_global_entry and tt_local_entry structures have the same initial fields such
as 'addr' and 'hash_entry'. To improve the code readability and to avoid
mistakes in later changes, a common substructure that substitute the shared
fields has been introduced (struct tt_common_entry).

Thanks to this modification, it has also been possible to slightly reduce the
code length by merging some functions like compare_ltt/gtt() and
tt_local/global_hash_find()
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

When the translation tables (global and local) are written for debugfs,
it is not neccesary to allocate a buffer, we can directly use
seq_printf() to print them out.

This might actually be safer if the table changes between size
calculation and traversal, and we can't estimate the required size
wrong.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

There are two reasons for this fix:
- the result of choose_orig() and vis_choose() is an index and therefore it can't
  be negative. Hence it is correct to make the return type unsigned too.

- sizeof(int) may not be the same on ALL the architectures. Since we plan to use
  choose_orig() as DHT hash function, we need to guarantee that, given the same
  argument, the result is the same. Then it is correct to explicitly express
  the size of the return type (and the second argument). Since the expected
  length is currently 4, uint32_t is the most convenient choice.
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

get_orig_node() tries to retrieve an orig_node object based on a mac address
and creates it if not present. This is not the wanted behaviour in the
translation table code as we don't want to create new orig_code objects but
expect a NULL pointer if the object does not exist.
Reported-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

When deleting the entries, tt_global_del_orig() has to print the message passed
as argument instead of a static one.
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

After removing the batman-adv module, the hash may be already gone
when tt_global_del_orig() tries to clean the hash. This patch adds
a sanity check to avoid this.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Tested-by: NAlexey Fisher <bug-track@fisher-privat.net>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

struct tt_global_entry holds a reference to an orig_node which must be
decremented before deallocating the structure.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Tested-by: NAlexey Fisher <bug-track@fisher-privat.net>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

In the TT_RESPONSE packet, the number of carried entries is not correctly set.
This leads to a wrong interpretation of the packet payload on the receiver side
causing random entries to be added to the global translation table. Therefore
the latter gets always corrupted, triggering a table recovery all the time.
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

Currently the counter of tt_local_entry structures (tt_local_num) is incremented
each time the tt_local_reset_flags() is invoked causing the node to send wrong
TT_REPONSE packets containing a copy of non-initialised memory thus corrupting
other nodes global translation table and making higher level communication
impossible.
Reported-by: NJunkeun Song <jun361@gmail.com>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Acked-by: NJunkeun Song <jun361@gmail.com>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

Since clients can have several flags on or off, this patches make them
appear in the local/global transtable output so that they can be checked
for debugging purposes.
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

If a node has to send a packet issued by a WIFI client to another WIFI client,
the packet is dropped.
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

When a node receives a unicast packet it checks if the source and the
destination client can communicate or not due to the AP isolation
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

Clients connected through a 802.11 device are now marked with the
TT_CLIENT_WIFI flag. This flag is also advertised with the tt
announcement.
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

Several typos have been corrected and some sentences have been rephrased
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

To keep consistency of other originator tables, new clients detected as
roamed, are kept in the global table but are marked as TT_CLIENT_PENDING
They are purged only when the new ttvn is received by the corresponding
originator. Moreover they need to be considered as removed in case of global
transtable lookup.
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

To keep transtable consistency among all the nodes, an originator must
not send not yet announced clients within a full table TT_RESPONSE.
Instead, deleted client have to be kept in the table in order to be sent
within an immediate TT_RESPONSE. In this way all the nodes in the
network will always provide the same response for the same request.

All the modification are committed at the next ttvn increment event.
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>