History log of /net/batman-adv/unicast.c
Revision Date Author Comments
c1d07431b9f7fe3c5eb372f3a35d7cd7a18c3b15 15-Jan-2013 Antonio Quartulli <ordex@autistici.org> batman-adv: don't use !! in bool conversion

In C standard any expression different from 0 will be converted to
'true' when casting to bool (whatever is the length of the value).
Therefore all the "!!" conversions can be removed.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
0b87393146244c2dc31cb3c69c45f4948ca94ee1 04-Jan-2013 Antonio Quartulli <ordex@autistici.org> batman-adv: update copyright years

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
46d160ef887963f26fee2df3d3b99eab54637014 01-Dec-2012 Antonio Quartulli <ordex@autistici.org> batman-adv: remove useless blank lines before and after brackets

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
bb351ba0bba23f01af00e36bfe20897201f404fa 16-Oct-2012 Martin Hundebøll <martin@hundeboll.net> batman-adv: Add wrapper to look up neighbor and send skb

By adding batadv_send_skb_to_orig() in send.c, we can remove duplicate
code that looks up the next hop and then calls batadv_send_skb_packet().

Furthermore, this prepares the upcoming new implementation of
fragmentation, which requires the next hop to route packets.

Please note that this doesn't entirely remove the next-hop lookup in
routing.c and unicast.c, since it is used by the current fragmentation
code.

Also note that the next-hop info is removed from debug messages in
translation-table.c, since it is looked up elsewhere.

Signed-off-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
785ea1144182c341b8b85b0f8180291839d176a8 23-Nov-2011 Antonio Quartulli <ordex@autistici.org> batman-adv: Distributed ARP Table - create DHT helper functions

Add all the relevant functions in order to manage a Distributed Hash Table over
the B.A.T.M.A.N.-adv network. It will later be used to store several ARP entries
and implement DAT (Distributed ARP Table)

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
7cdcf6dddc428c90ac867267a8d301e9e8b25612 01-Oct-2012 Antonio Quartulli <ordex@autistici.org> batman-adv: add UNICAST_4ADDR packet type

The current unicast packet type does not contain the orig source address. This
patches add a new unicast packet (called UNICAST_4ADDR) which provides two new
fields: the originator source address and the subtype (the type of the data
contained in the packet payload). The former is useful to identify the node
which injected the packet into the network and the latter is useful to avoid
creating new unicast packet types in the future: a macro defining a new subtype
will be enough.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
c67893d17a6bbd16328a1ee38ab0cb460511014a 08-Jul-2012 Sven Eckelmann <sven@narfation.org> batman-adv: Reduce accumulated length of simple statements

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
bbb1f90efba89b31fc5e329d5fcaf10aca99212b 08-Jul-2012 Sven Eckelmann <sven@narfation.org> batman-adv: Don't break statements after assignment operator

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
0aca2369b19de3f3f1affcc5359c3d079e4e1940 19-Jun-2012 Sven Eckelmann <sven@narfation.org> batman-adv: Fix alignment after opened parentheses

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
56303d34a332be8e2f4daf7891ebc12cb7900529 05-Jun-2012 Sven Eckelmann <sven@narfation.org> batman-adv: Prefix types structs with batadv_

Reported-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
96412690116afcc1b2705615b5a7c8dc6c5e905f 05-Jun-2012 Sven Eckelmann <sven@narfation.org> batman-adv: Prefix packet structs with batadv_

Reported-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
acd34afa89772f6379b642bb979d0a112328c769 03-Jun-2012 Sven Eckelmann <sven@narfation.org> batman-adv: Prefix packet enum with BATADV_

Reported-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
42d0b044b7c9e5821f1bf3e2b4ea7861417c11c2 03-Jun-2012 Sven Eckelmann <sven@narfation.org> batman-adv: Prefix main defines with BATADV_

Reported-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
4d5d2db8d5a40b18e562fe2fa4ef9b1f9710ff82 03-Jun-2012 Sven Eckelmann <sven@narfation.org> batman-adv: Prefix unicast defines with BATADV_

Reported-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
7e071c79a6964130d1df4dc5ca5a6f3638680fce 03-Jun-2012 Sven Eckelmann <sven@narfation.org> batman-adv: Prefix packet defines with BATADV_

Reported-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
0354440ba142eb9b6a03d287349350c1f75e5786 16-May-2012 Sven Eckelmann <sven@narfation.org> batman-adv: Prefix unicast local static functions with batadv_

All non-static symbols of batman-adv were prefixed with batadv_ to avoid
collisions with other symbols of the kernel. Other symbols of batman-adv
should use the same prefix to keep the naming scheme consistent.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
da641193dd3117ccd408dc589a131f16286b0da0 12-May-2012 Sven Eckelmann <sven@narfation.org> batman-adv: Prefix originator static inline functions with batadv_

All non-static symbols of batman-adv were prefixed with batadv_ to avoid
collisions with other symbols of the kernel. Other symbols of batman-adv
should use the same prefix to keep the naming scheme consistent.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
e5d89254bf763da35b42a3c65289c9962f7240c2 12-May-2012 Sven Eckelmann <sven@narfation.org> batman-adv: Prefix hard-interface static inline functions with batadv_

All non-static symbols of batman-adv were prefixed with batadv_ to avoid
collisions with other symbols of the kernel. Other symbols of batman-adv
should use the same prefix to keep the naming scheme consistent.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
9cfc7bd608b97463993b4f3e4775d99022253f8d 12-May-2012 Sven Eckelmann <sven@narfation.org> batman-adv: Reformat multiline comments to consistent style

batman-adv doesn't follow the style for multiline comments that David S. Miller
prefers. All comments should be reformatted to follow this consistent style to
make the code slightly more readable.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
88ed1e7772bbedfd0bb013c209f61619eca0a781 12-May-2012 Sven Eckelmann <sven@narfation.org> batman-adv: Prefix unicast non-static functions with batadv_

batman-adv can be compiled as part of the kernel instead of an module. In that
case the linker will see all non-static symbols of batman-adv and all other
non-static symbols of the kernel. This could lead to symbol collisions. A
prefix for the batman-adv symbols that defines their private namespace avoids
such a problem.

Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
08c36d3e8ad1f73d3b0322842363b23f6d203630 12-May-2012 Sven Eckelmann <sven@narfation.org> batman-adv: Prefix translation-table non-static functions with batadv_

batman-adv can be compiled as part of the kernel instead of an module. In that
case the linker will see all non-static symbols of batman-adv and all other
non-static symbols of the kernel. This could lead to symbol collisions. A
prefix for the batman-adv symbols that defines their private namespace avoids
such a problem.

Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
04b482a21aaf22cf5b327fb6a3fba6fdc8cb3de9 12-May-2012 Sven Eckelmann <sven@narfation.org> batman-adv: Prefix soft-interface non-static functions with batadv_

batman-adv can be compiled as part of the kernel instead of an module. In that
case the linker will see all non-static symbols of batman-adv and all other
non-static symbols of the kernel. This could lead to symbol collisions. A
prefix for the batman-adv symbols that defines their private namespace avoids
such a problem.

Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
9455e34cb2ded22e01abb6daa65ba1caeed8d7fe 12-May-2012 Sven Eckelmann <sven@narfation.org> batman-adv: Prefix send non-static functions with batadv_

batman-adv can be compiled as part of the kernel instead of an module. In that
case the linker will see all non-static symbols of batman-adv and all other
non-static symbols of the kernel. This could lead to symbol collisions. A
prefix for the batman-adv symbols that defines their private namespace avoids
such a problem.

Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
30d3c5113f9a3f162d65d01b771b122afac0ce79 12-May-2012 Sven Eckelmann <sven@narfation.org> batman-adv: Prefix routing non-static functions with batadv_

batman-adv can be compiled as part of the kernel instead of an module. In that
case the linker will see all non-static symbols of batman-adv and all other
non-static symbols of the kernel. This could lead to symbol collisions. A
prefix for the batman-adv symbols that defines their private namespace avoids
such a problem.

Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
7d211efc5087bc8870fa3374da88b4bf8159e79b 12-May-2012 Sven Eckelmann <sven@narfation.org> batman-adv: Prefix originator non-static functions with batadv_

batman-adv can be compiled as part of the kernel instead of an module. In that
case the linker will see all non-static symbols of batman-adv and all other
non-static symbols of the kernel. This could lead to symbol collisions. A
prefix for the batman-adv symbols that defines their private namespace avoids
such a problem.

Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
7cf06bc6ff810178a7fb9f12aaa6b274fc520f6f 12-May-2012 Sven Eckelmann <sven@narfation.org> batman-adv: Prefix gateway-client non-static functions with batadv_

batman-adv can be compiled as part of the kernel instead of an module. In that
case the linker will see all non-static symbols of batman-adv and all other
non-static symbols of the kernel. This could lead to symbol collisions. A
prefix for the batman-adv symbols that defines their private namespace avoids
such a problem.

Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
3275e7cc84fb0574e9662e8e74c3b1dab38f7143 16-Mar-2012 Antonio Quartulli <ordex@autistici.org> batman-adv: improve unicast packet (re)routing

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: Antonio Quartulli <ordex@autistici.org>
40e0c4f51d3fc3fd54edc797adae314fbe2b96a6 07-Mar-2012 Sven Eckelmann <sven@narfation.org> batman-adv: Remove spaces after a cast

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
567db7b0b7c0a94cc62846f8ebb429bdda2884bc 01-Jan-2012 Sven Eckelmann <sven@narfation.org> batman-adv: Update copyright years

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
76543d14aec6ce5cb3fc7be9b39c50fcebd2043b 20-Nov-2011 Sven Eckelmann <sven@narfation.org> batman-adv: Explicitly mark the common header structure

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: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
3d393e47321062dbf9078a66a7cc1c2a52bafecc 07-Jul-2011 Antonio Quartulli <ordex@autistici.org> batman-adv: implement AP-isolation on the sender side

If a node has to send a packet issued by a WIFI client to another WIFI client,
the packet is dropped.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
a73105b8d4c765d9ebfb664d0a66802127d8e4c7 27-Apr-2011 Antonio Quartulli <ordex@autistici.org> batman-adv: improved client announcement mechanism

The client announcement mechanism informs every mesh node in the network
of any connected non-mesh client, in order to find the path towards that
client from any given point in the mesh.

The old implementation was based on the simple idea of appending a data
buffer to each OGM containing all the client MAC addresses the node is
serving. All other nodes can populate their global translation tables
(table which links client MAC addresses to node addresses) using this
MAC address buffer and linking it to the node's address contained in the
OGM. A node that wants to contact a client has to lookup the node the
client is connected to and its address in the global translation table.

It is easy to understand that this implementation suffers from several
issues:
- big overhead (each and every OGM contains the entire list of
connected clients)
- high latencies for client route updates due to long OGM trip time and
OGM losses

The new implementation addresses these issues by appending client
changes (new client joined or a client left) to the OGM instead of
filling it with all the client addresses each time. In this way nodes
can modify their global tables by means of "updates", thus reducing the
overhead within the OGMs.

To keep the entire network in sync each node maintains a translation
table version number (ttvn) and a translation table checksum. These
values are spread with the OGM to allow all the network participants to
determine whether or not they need to update their translation table
information.

When a translation table lookup is performed in order to send a packet
to a client attached to another node, the destination's ttvn is added to
the payload packet. Forwarding nodes can compare the packet's ttvn with
their destination's ttvn (this node could have a fresher information
than the source) and re-route the packet if necessary. This greatly
reduces the packet loss of clients roaming from one AP to the next.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
704509b8d44886cebfbaff1a9813c35dfa986954 14-May-2011 Sven Eckelmann <sven@narfation.org> batman-adv: Calculate sizeof using variable insead of types

Documentation/CodingStyle recommends to use the form

p = kmalloc(sizeof(*p), ...);

to calculate the size of a struct and not the version where the struct
name is spelled out to prevent bugs when the type of p changes. This
also seems appropriate for manipulation of buffers when they are
directly associated with p.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
958ca5985604a6f13387d32de489365df816558b 14-May-2011 Sven Eckelmann <sven@narfation.org> batman-adv: Remove casts from type x to type x

Casting from pointer like 'struct orig_node*' to 'struct orig_node *'
doesn't provide any additional functionality and can be savely removed.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
747e4221a03cde62402b614ca1f8e961b8416130 14-May-2011 Sven Eckelmann <sven@narfation.org> batman-adv: Add const type qualifier for pointers

batman-adv uses pointers which are marked as const and should not
violate that type qualifier by passing it to functions which force a
cast to the non-const version.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
e2cbc11c0e1225bd5fe183a967fc80df3db10745 08-May-2011 Antonio Quartulli <ordex@autistici.org> batman-adv: move neigh_node->if_incoming->if_status check in find_router()

Every time that find_router() is invoked, if_status has to be compared with
IF_ACTIVE. Moving this comparison inside find_router() will avoid to write it
each time.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
2dafb49d84a9195193b28ac5047df1bbab6053b9 05-May-2011 Antonio Quartulli <ordex@autistici.org> batman-adv: rename everything from *hna* into *tt* (translation table)

To be coherent, all the functions/variables/constants have been renamed
to the TranslationTable style

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
32ae9b221e788413ce68feaae2ca39e406211a0a 20-Apr-2011 Marek Lindner <lindner_marek@yahoo.de> batman-adv: Make bat_priv->primary_if an rcu protected pointer

The rcu protected macros rcu_dereference() and rcu_assign_pointer()
for the bat_priv->primary_if need to be used, as well as spin/rcu locking.

Otherwise we might end up using a primary_if pointer pointing to already
freed memory.

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
c4aac1ab9b973798163b34939b522f01e4d28ac9 23-Mar-2011 Marek Lindner <lindner_marek@yahoo.de> batman-adv: concentrate all curr_gw related rcu operations in select/deselect functions

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
e6c10f433af9c98994c94a10ae862c152fcfb2a9 18-Feb-2011 Marek Lindner <lindner_marek@yahoo.de> batman-adv: rename batman_if struct to hard_iface

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
d0072609baebaffb522083d367f4f195187f60f8 19-Jan-2011 Marek Lindner <lindner_marek@yahoo.de> batman-adv: remove orig_hash spinlock

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
7b36e8eef989fc59535b4f1d3fc0f83afaf419d4 18-Feb-2011 Marek Lindner <lindner_marek@yahoo.de> batman-adv: Correct rcu refcounting for orig_node

It might be possible that 2 threads access the same data in the same
rcu grace period. The first thread calls call_rcu() to decrement the
refcount and free the data while the second thread increases the
refcount to use the data. To avoid this race condition all refcount
operations have to be atomic.

Reported-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
7aadf889e897155c45cda230d2a6701ad1fbff61 18-Feb-2011 Marek Lindner <lindner_marek@yahoo.de> batman-adv: remove extra layer between hash and hash element - hash bucket

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
43c70ad5ce5691cce24dae6610731694c0f3fcc8 13-Feb-2011 Linus Lüssing <linus.luessing@ascom.ch> batman-adv: Increase orig_node refcount before releasing rcu read lock

When unicast_send_skb() is increasing the orig_node's refcount another
thread might have been freeing this orig_node already. We need to
increase the refcount in the rcu read lock protected area to avoid that.

Signed-off-by: Linus Lüssing <linus.luessing@ascom.ch>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
44524fcdf6ca19b58c24f7622c4af1d8d8fe59f8 10-Feb-2011 Marek Lindner <lindner_marek@yahoo.de> batman-adv: Correct rcu refcounting for neigh_node

It might be possible that 2 threads access the same data in the same
rcu grace period. The first thread calls call_rcu() to decrement the
refcount and free the data while the second thread increases the
refcount to use the data. To avoid this race condition all refcount
operations have to be atomic.

Reported-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
a4c135c561106c397bae33455acfca4aa8065a30 19-Jan-2011 Simon Wunderlich <siwu@hrz.tu-chemnitz.de> batman-adv: protect bonding with rcu locks

bonding / alternating candidates need to be secured by rcu locks
as well. This patch therefore converts the bonding list
from a plain pointer list to a rcu securable lists and references
the bonding candidates.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
fb778ea173fcd58b8fc3d75c674f07fab187b55f 19-Jan-2011 Marek Lindner <lindner_marek@yahoo.de> batman-adv: protect each hash row with rcu locks

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
3878f1f075470990d9c2418b53f31694e774f743 07-Feb-2011 Linus Lüssing <linus.luessing@ascom.ch> batman-adv: Disallow originator addressing within mesh layer

For a host in the mesh network, the batman layer should be transparent.
However, we had one exception, data packets within the mesh network
which have the same destination as a originator are being routed to
that node, although there is no host that node's bat0 interface and
therefore gets dropped anyway. This commit removes this exception.

Signed-off-by: Linus Lüssing <linus.luessing@ascom.ch>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
14062064167ecdda4a17ec9190740c189223550a 08-Feb-2011 Marek Lindner <lindner_marek@yahoo.de> batman-adv: Split combined variable declarations

Multiple variable declarations in a single statements over multiple lines can
be split into multiple variable declarations without changing the actual
behavior.

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
c2f7f0e7b3ce55eee32892d6aa5cd88a7512ea25 10-Feb-2011 Sven Eckelmann <sven@narfation.org> batman-adv: Use successive sequence numbers for fragments

The two fragments of an unicast packet must have successive sequence numbers to
allow the receiver side to detect matching fragments and merge them again. The
current implementation doesn't provide that property because a sequence of two
atomic_inc_return may be interleaved with another sequence which also changes
the variable.

The access to the fragment sequence number pool has either to be protected by
correct locking or it has to reserve two sequence numbers in a single fetch.
The latter one can easily be done by increasing the value of the last used
sequence number by 2 in a single step. The generated window of two currently
unused sequence numbers can now be scattered across the two fragments.

Reported-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
531c9da8c854c5b075383253a57fdd4e0be82e99 07-Feb-2011 Sven Eckelmann <sven@narfation.org> batman-adv: Linearize fragment packets before merge

We access the data inside the skbs of two fragments directly using memmove
during the merge. The data of the skb could span over multiple skb pages. An
direct access without knowledge about the pages would lead to an invalid memory
access.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
[lindner_marek@yahoo.de: Move return from function to the end]
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
64afe35398269577ef9809474dd7dc0e5d265176 27-Jan-2011 Sven Eckelmann <sven@narfation.org> batman-adv: Update copyright years

Signed-off-by: Sven Eckelmann <sven@narfation.org>
ae361ce19fa135035c6b83ac1f07090b72fd4b8f 25-Jan-2011 Sven Eckelmann <sven@narfation.org> batman-adv: Calculate correct size for merged packets

The routing algorithm must be able to decide if a fragment can be merged with
the missing part and still be passed to a forwarding interface. The fragments
can only differ by one byte in case that the original payload had an uneven
length. In that situation the sender has to inform all possible receivers that
the tail is one byte longer using the flag UNI_FRAG_LARGETAIL.

The combination of UNI_FRAG_LARGETAIL and UNI_FRAG_HEAD flag makes it possible
to calculate the correct length for even and uneven sized payloads.

The original formula missed to add the unicast header at all and forgot to
remove the fragment header of the second fragment. This made the results highly
unreliable and only useful for machines with large differences between the
configured MTUs.

Reported-by: Russell Senior <russell@personaltelco.net>
Reported-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
5c77d8bb8aeb4ec6804b6c32061109ba2ea6988d 25-Jan-2011 Sven Eckelmann <sven@narfation.org> batman-adv: Create roughly equal sized fragments

The routing algorithm must know how large two fragments are to be able to
decide that it is safe to merge them or if it should resubmit without waiting
for the second part. When these two fragments have a too different size, it is
not possible to guess right in every situation.

The user could easily configure the MTU of the attached cards so that one
fragment is forwarded and the other one is added to the fragments table to wait
for the missing part.

For even sized packets, it is possible to split it so that the resulting
packages are equal sized by ignoring the old non-fragment header at the
beginning of the original packet.

This still creates different sized fragments for uneven sized packets.

Reported-by: Russell Senior <russell@personaltelco.net>
Reported-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
ed7809d9c41b514115ddffaa860694393c2016b3 13-Jan-2011 Jesper Juhl <jj@chaosbits.net> batman-adv: Even Batman should not dereference NULL pointers

There's a problem in net/batman-adv/unicast.c::frag_send_skb().
dev_alloc_skb() allocates memory and may fail, thus returning NULL. If
this happens we'll pass a NULL pointer on to skb_split() which in turn
hands it to skb_split_inside_header() from where it gets passed to
skb_put() that lets skb_tail_pointer() play with it and that function
dereferences it. And thus the bat dies.

While I was at it I also moved the call to dev_alloc_skb() above the
assignment to 'unicast_packet' since there's no reason to do that
assignment if the memory allocation fails.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
c6c8fea29769d998d94fcec9b9f14d4b52b349d3 13-Dec-2010 Sven Eckelmann <sven@narfation.org> net: Add batman-adv meshing protocol

B.A.T.M.A.N. (better approach to mobile ad-hoc networking) is a routing
protocol for multi-hop ad-hoc mesh networks. The networks may be wired or
wireless. See http://www.open-mesh.org/ for more information and user space
tools.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>