linux-toradex.git/net/batman-adv/multicast.c, branch v4.4.95

batman-adv: Add lockdep_asserts for documented external locks

2015-08-24T22:12:23+00:00

Some functions already have documentation about locks they require inside
their kerneldoc header. These can be directly tested during runtime using
the lockdep asserts.

Signed-off-by: Sven Eckelmann 
Signed-off-by: Marek Lindner 
Signed-off-by: Antonio Quartulli

batman-adv: Annotate deleting functions with external lock via lockdep

2015-08-24T22:12:23+00:00

Functions which use (h)list_del* are requiring correct locking when they
operate on global lists. Most of the time the search in the list and the
delete are done in the same function. All other cases should have it
visible that they require a special lock to avoid race conditions.

Lockdep asserts can be used to check these problem during runtime when the
lockdep functionality is enabled.

Signed-off-by: Sven Eckelmann 
Signed-off-by: Marek Lindner 
Signed-off-by: Antonio Quartulli

batman-adv: Replace C99 int types with kernel type

2015-08-24T22:12:17+00:00

(s|u)(8|16|32|64) are the preferred types in the kernel. The use of the
standard C99 types u?int(8|16|32|64)_t are objected by some people and even
checkpatch now warns about using them.

Signed-off-by: Sven Eckelmann 
Signed-off-by: Marek Lindner 
Signed-off-by: Antonio Quartulli

batman-adv: Fix potential synchronization issues in mcast tvlv handler

2015-08-14T20:52:08+00:00

So far the mcast tvlv handler did not anticipate the processing of
multiple incoming OGMs from the same originator at the same time. This
can lead to various issues:

* Broken refcounting: For instance two mcast handlers might both assume
  that an originator just got multicast capabilities and will together
  wrongly decrease mcast.num_disabled by two, potentially leading to
  an integer underflow.

* Potential kernel panic on hlist_del_rcu(): Two mcast handlers might
  one after another try to do an
  hlist_del_rcu(&orig->mcast_want_all_*_node). The second one will
  cause memory corruption / crashes.
  (Reported by: Sven Eckelmann )

Right in the beginning the code path makes assumptions about the current
multicast related state of an originator and bases all updates on that. The
easiest and least error prune way to fix the issues in this case is to
serialize multiple mcast handler invocations with a spinlock.

Fixes: 60432d756cf0 ("batman-adv: Announce new capability via multicast TVLV")
Signed-off-by: Linus Lüssing 
Signed-off-by: Marek Lindner 
Signed-off-by: Antonio Quartulli

batman-adv: Make MCAST capability changes atomic

2015-08-14T20:51:40+00:00

Bitwise OR/AND assignments in C aren't guaranteed to be atomic. One
OGM handler might undo the set/clear of a specific bit from another
handler run in between.

Fix this by using the atomic set_bit()/clear_bit()/test_bit() functions.

Fixes: 60432d756cf0 ("batman-adv: Announce new capability via multicast TVLV")
Signed-off-by: Linus Lüssing 
Signed-off-by: Marek Lindner 
Signed-off-by: Antonio Quartulli

batman-adv: Add required includes to all files

2015-06-07T15:07:19+00:00

The header files could not be build indepdent from each other. This is
happened because headers didn't include the files for things they've used.
This was problematic because the success of a build depended on the
knowledge about the right order of local includes.

Also source files were not including everything they've used explicitly.
Instead they required that transitive includes are always stable. This is
problematic because some transitive includes are not obvious, depend on
config settings and may not be stable in the future.

The order for include blocks are:

 * primary headers (main.h and the *.h file of a *.c file)
 * global linux headers
 * required local headers
 * extra forward declarations for pointers in function/struct declarations

The only exceptions are linux/bitops.h and linux/if_ether.h in packet.h.
This header file is shared with userspace applications like batctl and must
therefore build together with userspace applications. The header
linux/bitops.h is not part of the uapi headers and linux/if_ether.h
conflicts with the musl implementation of netinet/if_ether.h. The
maintainers rejected the use of __KERNEL__ preprocessor checks and thus
these two headers are only in main.h. All files using packet.h first have
to include main.h to work correctly.

Reported-by: Markus Pargmann 
Signed-off-by: Sven Eckelmann 
Signed-off-by: Marek Lindner

batman-adv: update copyright years for 2015

2015-05-29T08:13:35+00:00

Signed-off-by: Sven Eckelmann 
Signed-off-by: Marek Lindner

batman-adv: fix multicast counter when purging originators

2015-01-06T10:06:04+00:00

When purging an orig_node we should only decrease counter tracking the
number of nodes without multicast optimizations support if it was
increased through this orig_node before.

A not yet quite initialized orig_node (meaning it did not have its turn
in the mcast-tvlv handler so far) which gets purged would not adhere to
this and will lead to a counter imbalance.

Fixing this by adding a check whether the orig_node is mcast-initalized
before decreasing the counter in the mcast-orig_node-purging routine.

Introduced by 60432d756cf06e597ef9da511402dd059b112447
("batman-adv: Announce new capability via multicast TVLV")

Reported-by: Tobias Hachmer 
Signed-off-by: Linus Lüssing 
Signed-off-by: Marek Lindner 
Signed-off-by: Antonio Quartulli

batman-adv: fix counter for multicast supporting nodes

2015-01-06T10:05:42+00:00

A miscounting of nodes having multicast optimizations enabled can lead
to multicast packet loss in the following scenario:

If the first OGM a node receives from another one has no multicast
optimizations support (no multicast tvlv) then we are missing to
increase the counter. This potentially leads to the wrong assumption
that we could safely use multicast optimizations.

Fixings this by increasing the counter if the initial OGM has the
multicast TVLV unset, too.

Introduced by 60432d756cf06e597ef9da511402dd059b112447
("batman-adv: Announce new capability via multicast TVLV")

Reported-by: Tobias Hachmer 
Signed-off-by: Linus Lüssing 
Signed-off-by: Marek Lindner 
Signed-off-by: Antonio Quartulli

batman: fix duplicate #include of multicast.h

2014-08-07T23:02:57+00:00

The header multicast.h was included twice, so delete one of them.

Signed-off-by: Jean Sacren 
Cc: Marek Lindner 
Cc: Simon Wunderlich 
Cc: Antonio Quartulli 
Cc: b.a.t.m.a.n@lists.open-mesh.org
Signed-off-by: David S. Miller