Commit Graph

209 Commits

Author SHA1 Message Date
Sven Eckelmann
5c77d8bb8a 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>
2011-01-31 14:57:08 +01:00
Sven Eckelmann
1181e1daac batman-adv: Make vis info stack traversal threadsafe
The batman-adv vis server has to a stack which stores all information
about packets which should be send later. This stack is protected
with a spinlock that is used to prevent concurrent write access to it.

The send_vis_packets function has to take all elements from the stack
and send them to other hosts over the primary interface. The send will
be initiated without the lock which protects the stack.

The implementation using list_for_each_entry_safe has the problem that
it stores the next element as "safe ptr" to allow the deletion of the
current element in the list. The list may be modified during the
unlock/lock pair in the loop body which may make the safe pointer
not pointing to correct next element.

It is safer to remove and use the first element from the stack until no
elements are available. This does not need reduntant information which
would have to be validated each time the lock was removed.

Reported-by: Russell Senior <russell@personaltelco.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-01-30 10:32:08 +01:00
Sven Eckelmann
dda9fc6b2c batman-adv: Remove vis info element in free_info
The free_info function will be called when no reference to the info
object exists anymore. It must be ensured that the allocated memory
gets freed and not only the elements which are managed by the info
object.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-01-30 10:32:06 +01:00
Sven Eckelmann
2674c15870 batman-adv: Remove vis info on hashing errors
A newly created vis info object must be removed when it couldn't be
added to the hash. The old_info which has to be replaced was already
removed and isn't related to the hash anymore.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-01-30 10:32:02 +01:00
Linus Lüssing
dd58ddc692 batman-adv: Fix kernel panic when fetching vis data on a vis server
The hash_iterate removal introduced a bug leading to a kernel panic when
fetching the vis data on a vis server. That commit forgot to rename one
variable name, which this commit fixes now.

Reported-by: Russell Senior <russell@personaltelco.net>
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-01-25 23:58:33 +01:00
Sven Eckelmann
aa0adb1a85 batman-adv: Use "__attribute__" shortcut macros
Linux 2.6.21 defines different macros for __attribute__ which are also
used inside batman-adv. The next version of checkpatch.pl warns about
the usage of __attribute__((packed))).

Linux 2.6.33 defines an extra macro __always_unused which is used to
assist source code analyzers and can be used to removed the last
existing __attribute__ inside the source code.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
2011-01-16 03:25:19 +01:00
Jesper Juhl
ed7809d9c4 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>
2011-01-13 22:11:12 +01:00
Sven Eckelmann
53320fe3bb batman-adv: Return hna count on local buffer fill
hna_local_fill_buffer must return the number of added hna entries and
not the last checked hash bucket.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-20 10:32:03 -08:00
Sven Eckelmann
c6c8fea297 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>
2010-12-16 13:44:24 -08:00