Prior to this patch the translation table code made assumptions about how
the routing protocol works and where its buffers are stored (to directly
modify them).
Each protocol now calls the tt code with the relevant pointers, thereby
abstracting the code.
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
Acked-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

In the code we neever need to atomically check and set the bat_priv->tt_crc
field value. It is simply set and read once in different pieces of the code.
Therefore this field can be safely be converted from atomic_t to uint16_t.
Reported-by: NAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

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

Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
Acked-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

Instead of using sizeof(struct ethhdr) it is strongly recommended to use the
kernel macro ETH_HLEN. This patch substitute each occurrence of the former
expressione with the latter one.
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>

Using BATMAN_OGM_LEN leaves one with the impression that this is
the full packet size which is not the case. Therefore the variable
is renamed.
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
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>

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

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>

In the process the batman iv OGM aggregation code could be merged
into the batman iv code base which makes the separate aggregation
files superfluous.
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

The follow-up routing code changes are going to introduce additional
routing packet types which make this distinction necessary.
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 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>

The primary interface OGM has to be broadcasted on all hard-interfaces
even if the primary interface is not the first interface (if_num = 0).
Therefore the code has to compare the originating interface with the
primary interface instead of checking the if_num.
Reported-by: NLinus Luessing <linus.luessing@web.de>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

In order to make possible to use the broadcast list for delayed sendings
the "delay" parameter is now provided instead of using 1 as hardcoded
value.
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

With the current client announcement implementation, in case of roaming,
an update is triggered on the new AP serving the client. At that point
the new information is spread around by means of the OGM broadcasting
mechanism. Until this operations is not executed, no node is able to
correctly route traffic towards the client. This obviously causes packet
drops and introduces a delay in the time needed by the client to recover
its connections.

A new packet type called ROAMING_ADVERTISEMENT is added to account this
issue.

This message is sent in case of roaming from the new AP serving the
client to the old one and will contain the client MAC address. In this
way an out-of-OGM update is immediately committed, so that the old node
can update its global translation table. Traffic reaching this node will
then be redirected to the correct destination utilising the fresher
information. Thus reducing the packet drops and the connection recovery
delay.
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

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

char was used in different places to store information without really
using the characteristics of that data type or by ignoring the fact that
char has not a well defined signedness.
Signed-off-by: NSven Eckelmann <sven@narfation.org>

The definition NO_FLAGS was introduced to make the code more
readable and shall be used to initialize flag fields.
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

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: NSven Eckelmann <sven@narfation.org>

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: NSven Eckelmann <sven@narfation.org>

The broadcast flood protection should be reset to its original value
if the primary interface could not be retrieved.
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

add_bcast_packet_to_list increases the refcount for if_incoming but the
reference count is never decreased. The reference count must be
increased for all kinds of forwarded packets which have the primary
interface stored and forw_packet_free must decrease them. Also
purge_outstanding_packets has to invoke forw_packet_free when a work
item was really cancelled.

This regression was introduced in
32ae9b22.
Reported-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

To be coherent, all the functions/variables/constants have been renamed
to the TranslationTable style
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

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

atomic_dec_not_zero() is very useful and it is currently defined
multiple times. So it is possible to move it in main.h
Signed-off-by: NAntonio Quartulli <ordex@autistici.org>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

The rcu protected macros rcu_dereference() and rcu_assign_pointer()
for the orig_node->router need to be used, as well as spin/rcu locking.
Otherwise we might end up using a router pointer pointing to already
freed memory.

Therefore this commit introduces the safe getter method
orig_node_get_router().
Signed-off-by: NLinus Lüssing <linus.luessing@web.de>
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>

Batman-adv works with "hard interfaces" as well as "soft interfaces".
The new name should better make clear which kind of interfaces this
list stores.
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

Note: The function compare_ether_addr() provided by the Linux kernel
requires aligned memory.
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>

types.h is included by main.h, which is included at the beginning of any
other c-file anyway. Therefore this commit removes those duplicate
inclussions.
Signed-off-by: NLinus Lüssing <linus.luessing@ascom.ch>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

Signed-off-by: NSven Eckelmann <sven@narfation.org>

Some function parameters are obsolete now and can be removed.
Reported-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NSven Eckelmann <sven@narfation.org>

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

Via the /sys filesystem you can change the gateway mode of a node using
gw_mode. Adjustments to it can be done using gw_bandwidth for server
mode and gw_sel_class for client mode.
Signed-off-by: NMarek Lindner <lindner_marek@yahoo.de>
[sven.eckelmann@gmx.de: Rework on top of current version]
Signed-off-by: NSven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

spin_lock_irqsave disables the IRQs and stores them inside the flags
provided by the caller. This is needed to protect a bottom half handler
or a user context critical section from being interrupted by an
interrupt handler which also tries to acquire the spinlock and locks
forever.

The linux device drivers will receive the packets inside an interrupt
handler and the network infrastructure will process them inside bottom
half. Thus batman-adv will only run in user context and bottom half
handlers. We can conclude that batman-adv doesn't share its own
spinlocks with real interrupt handlers.

This makes it possible to exchange the quite complex spin_lock_irqsave
with spin_lock_bh which only stops bottom halves from running on the
current cpu, but allows interrupt handlers to take over to keep the
interrupt latency low.
Signed-off-by: NSven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Function pointers cannot be inlined by a compiler and thus always has
the overhead of an call. hashdata_compare_cb's are one of the most often
called function pointers and its overhead must kept relative low.

As first step, every function which uses this function pointer takes it
as parameter instead of storing it inside the hash abstraction
structure.

This not generate any performance gain right now. The called functions
must also be able to be inlined by the calling functions to enable
inlining of the function pointer.
Reported-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

When having a mixed topology of both very mobile and rather static
nodes, you are usually best advised to set the originator interval on
all nodes to a level best suited for the most mobile node.

However, if most of the nodes are rather static, this can create a lot
of undesired overhead as a trade-off then. If setting the interval too
low on the static nodes, a mobile node might be chosen as a router for
too long, not switching away from it fast enough because of its
mobility and the low frequency of ogms of static nodes.

Exposing the hop_penalty is especially useful for the stated scenario: A
static node can keep the default originator interval, a mobile node can
select a quicker one resulting in faster route updates towards this
mobile node. Additionally, such a mobile node could select a higher hop
penalty (or even set it to 255 to disable acting as a router for other
nodes) to make it less desirable, letting other nodes avoid selecting
this mobile node as a router.
Signed-off-by: NLinus Lüssing <linus.luessing@ascom.ch>
Signed-off-by: NSven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>