batman-adv: Check hardif MTU against runtime MTU

If the MTU of the soft/mesh interface was already reduced (enough), it is
not necessary to print a warning about a hard interface not having a MTU to
transport ethernet payloads of 1500 bytes.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Don't increase MTU when set by user

If the user set an MTU value, it usually means that there are special
requirements for the MTU. But if an interface gots activated, the MTU was
always recalculated and then the user set value was overwritten.

The only reason why this user set value has to be overwritten, is when the
MTU has to be decreased because batman-adv is not able to transfer packets
with the user specified size.

Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol")
Cc: stable@vger.kernel.org
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Trigger events for auto adjusted MTU

If an interface changes the MTU, it is expected that an NETDEV_PRECHANGEMTU
and NETDEV_CHANGEMTU notification events is triggered. This worked fine for
.ndo_change_mtu based changes because core networking code took care of it.
But for auto-adjustments after hard-interfaces changes, these events were
simply missing.

Due to this problem, non-batman-adv components weren't aware of MTU changes
and thus couldn't perform their own tasks correctly.

Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol")
Cc: stable@vger.kernel.org
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Fix hang up with small MTU hard-interface

The system hangs up when batman-adv soft-interface is created on
hard-interface with small MTU. For example, the following commands
create batman-adv soft-interface on dummy interface with zero MTU:

# ip link add name dummy0 type dummy
# ip link set mtu 0 dev dummy0
# ip link set up dev dummy0
# ip link add name bat0 type batadv
# ip link set dev dummy0 master bat0

These commands cause the system hang up with the following messages:

[ 90.578925][ T6689] batman_adv: bat0: Adding interface: dummy0
[ 90.580884][ T6689] batman_adv: bat0: The MTU of interface dummy0 is too small (0) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem.
[ 90.586264][ T6689] batman_adv: bat0: Interface activated: dummy0
[ 90.590061][ T6689] batman_adv: bat0: Forced to purge local tt entries to fit new maximum fragment MTU (-320)
[ 90.595517][ T6689] batman_adv: bat0: Forced to purge local tt entries to fit new maximum fragment MTU (-320)
[ 90.598499][ T6689] batman_adv: bat0: Forced to purge local tt entries to fit new maximum fragment MTU (-320)

This patch fixes this issue by returning error when enabling
hard-interface with small MTU size.

Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol")
Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

net: wrap the wireless pointers in struct net_device in an ifdef

Most protocol-specific pointers in struct net_device are under
a respective ifdef. Wireless is the notable exception. Since
there's a sizable number of custom-built kernels for datacenter
workloads which don't build wireless it seems reasonable to
ifdefy those pointers as well.

While at it move IPv4 and IPv6 pointers up, those are special
for obvious reasons.

Acked-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org> # ieee802154
Acked-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

batman-adv: Demote batadv-on-batadv skip error message

The error message "Cannot find parent device" was shown for users of
macvtap (on batadv devices) whenever the macvtap was moved to a different
netns. This happens because macvtap doesn't provide an implementation for
rtnl_link_ops->get_link_net.

The situation for which this message is printed is actually not an error
but just a warning that the optional sanity check was skipped. So demote
the message from error to warning and adjust the text to better explain
what happened.

Reported-by: Leonardo Mörlein <freifunk@irrelefant.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Migrate to linux/container_of.h

The commit d2a8ebbf8192 ("kernel.h: split out container_of() and
typeof_member() macros") introduced a new header for the container_of
related macros from (previously) linux/kernel.h.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Don't expect inter-netns unique iflink indices

The ifindex doesn't have to be unique for multiple network namespaces on
the same machine.

$ ip netns add test1
$ ip -net test1 link add dummy1 type dummy
$ ip netns add test2
$ ip -net test2 link add dummy2 type dummy

$ ip -net test1 link show dev dummy1
6: dummy1: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether 96:81:55:1e:dd:85 brd ff:ff:ff:ff:ff:ff
$ ip -net test2 link show dev dummy2
6: dummy2: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether 5a:3c:af:35:07:c3 brd ff:ff:ff:ff:ff:ff

But the batman-adv code to walk through the various layers of virtual
interfaces uses this assumption because dev_get_iflink handles it
internally and doesn't return the actual netns of the iflink. And
dev_get_iflink only documents the situation where ifindex == iflink for
physical devices.

But only checking for dev->netdev_ops->ndo_get_iflink is also not an option
because ipoib_get_iflink implements it even when it sometimes returns an
iflink != ifindex and sometimes iflink == ifindex. The caller must
therefore make sure itself to check both netns and iflink + ifindex for
equality. Only when they are equal, a "physical" interface was detected
which should stop the traversal. On the other hand, vxcan_get_iflink can
also return 0 in case there was currently no valid peer. In this case, it
is still necessary to stop.

Fixes: b7eddd0b3950 ("batman-adv: prevent using any virtual device created on batman-adv as hard-interface")
Fixes: 5ed4a460a1d3 ("batman-adv: additional checks for virtual interfaces on top of WiFi")
Reported-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Request iflink once in batadv_get_real_netdevice

There is no need to call dev_get_iflink multiple times for the same
net_device in batadv_get_real_netdevice. And since some of the
ndo_get_iflink callbacks are dynamic (for example via RCUs like in
vxcan_get_iflink), it could easily happen that the returned values are not
stable. The pre-checks before __dev_get_by_index are then of course bogus.

Fixes: 5ed4a460a1d3 ("batman-adv: additional checks for virtual interfaces on top of WiFi")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Request iflink once in batadv-on-batadv check

There is no need to call dev_get_iflink multiple times for the same
net_device in batadv_is_on_batman_iface. And since some of the
.ndo_get_iflink callbacks are dynamic (for example via RCUs like in
vxcan_get_iflink), it could easily happen that the returned values are not
stable. The pre-checks before __dev_get_by_index are then of course bogus.

Fixes: b7eddd0b3950 ("batman-adv: prevent using any virtual device created on batman-adv as hard-interface")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Drop NULL check before dropping references

The check if a batman-adv related object is NULL or not is now directly in
the batadv_*_put functions. It is not needed anymore to perform this check
outside these function:

The changes were generated using a coccinelle semantic patch:

@@
expression E;
@@
- if (likely(E != NULL))
(
batadv_backbone_gw_put
|
batadv_claim_put
|
batadv_dat_entry_put
|
batadv_gw_node_put
|
batadv_hardif_neigh_put
|
batadv_hardif_put
|
batadv_nc_node_put
|
batadv_nc_path_put
|
batadv_neigh_ifinfo_put
|
batadv_neigh_node_put
|
batadv_orig_ifinfo_put
|
batadv_orig_node_put
|
batadv_orig_node_vlan_put
|
batadv_softif_vlan_put
|
batadv_tp_vars_put
|
batadv_tt_global_entry_put
|
batadv_tt_local_entry_put
|
batadv_tt_orig_list_entry_put
|
batadv_tt_req_node_put
|
batadv_tvlv_container_put
|
batadv_tvlv_handler_put
)(E);

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Drop NULL check before dropping references

The check if a batman-adv related object is NULL or not is now directly in
the batadv_*_put functions. It is not needed anymore to perform this check
outside these function:

The changes were generated using a coccinelle semantic patch:

@@
expression E;
@@
- if (likely(E != NULL))
(
batadv_backbone_gw_put
|
batadv_claim_put
|
batadv_dat_entry_put
|
batadv_gw_node_put
|
batadv_hardif_neigh_put
|
batadv_hardif_put
|
batadv_nc_node_put
|
batadv_nc_path_put
|
batadv_neigh_ifinfo_put
|
batadv_neigh_node_put
|
batadv_orig_ifinfo_put
|
batadv_orig_node_put
|
batadv_orig_node_vlan_put
|
batadv_softif_vlan_put
|
batadv_tp_vars_put
|
batadv_tt_global_entry_put
|
batadv_tt_local_entry_put
|
batadv_tt_orig_list_entry_put
|
batadv_tt_req_node_put
|
batadv_tvlv_container_put
|
batadv_tvlv_handler_put
)(E);

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Drop reduntant batadv interface check

If batadv_hardif_enable_interface is called then its called from its
callback ndo_add_slave. It is therefore not necessary to check if it is a
batadv interface.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Don't manually reattach hard-interface

The batadv_hardif_enable_interface is now only called from the callback
ndo_add_slave. This callback is only used by do_set_master in the rtnetlink
code which only does two things:

1. remove the net_device from its old master
2. add the net_device to its new batadv master

The code to replicate the first step in batman-adv is therefore unused
since the sysfs code was dropped.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Avoid name based attaching of hard interfaces

The sysfs code for the batman-adv/mesh_iface file was receiving a string of
the batadv interface. This interface name was then provided to the code
which shared sysfs+rtnetlink code for attaching an hard-interface to an
batadv interface. The rtnetlink code was also using the (extracted)
interface name from the ndo_add_slave callback to increase the shared code
- even when it would have been more efficient to use the provided
net_device object directly instead of searching it again (based on its
name) in batadv_hardif_enable_interface.

But this indirect handling is no longer necessary because the sysfs code
was dropped. There is now only a single code path which is using
batadv_hardif_enable_interface.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Drop implicit creation of batadv net_devices

The sysfs code in batman-adv was could create a new batadv interfaces on
demand when a string (interface name) was written to the
batman-adv/mesh_iface file. But the code no longer exists in the current
batman-adv codebase. The helper code to implement this behavior must be
considered as unused and can be dropped.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Fix spelling mistakes

Fix some spelling mistakes in comments:
containg ==> containing
dont ==> don't
datas ==> data
brodcast ==> broadcast

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Drop publication years from copyright info

The batman-adv source code was using the year of publication (to net-next)
as "last" year for the copyright statement. The whole source code mentioned
in the MAINTAINERS "BATMAN ADVANCED" section was handled as a single entity
regarding the publishing year.

This avoided having outdated (in sense of year information - not copyright
holder) publishing information inside several files. But since the simple
"update copyright year" commit (without other changes) in the file was not
well received in the upstream kernel, the option to not have a copyright
year (for initial and last publication) in the files are chosen instead.
More detailed information about the years can still be retrieved from the
SCM system.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Acked-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Drop legacy code for auto deleting mesh interfaces

The only way to automatically drop batadv mesh interfaces when all soft
interfaces were removed was dropped with the sysfs support. It is no longer
needed to have them handled by kernel anymore.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Drop deprecated debugfs support

The debugfs support in batman-adv was marked as deprecated by the commit
00caf6a2b318 ("batman-adv: Mark debugfs functionality as deprecated") and
scheduled for removal in 2021.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Drop deprecated sysfs support

The sysfs in batman-adv support was marked as deprecated by the commit
42cdd521487f ("batman-adv: ABI: Mark sysfs files as deprecated") and
scheduled for removal in 2021.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Add new include for min/max helpers

The commit b296a6d53339 ("kernel.h: split out min()/max() et al. helpers")
moved the min/max helper functionality from kernel.h to minmax.h. Adjust
the kernel code accordingly to avoid fragile indirect includes.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Consider fragmentation for needed_headroom

If a batman-adv packets has to be fragmented, then the original batman-adv
packet header is not stripped away. Instead, only a new header is added in
front of the packet after it was split.

This size must be considered to avoid cost intensive reallocations during
the transmission through the various device layers.

Fixes: 7bca68c7844b ("batman-adv: Add lower layer needed_(head|tail)room to own ones")
Reported-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Drop repeated words in comments

checkpatch found various instances of "Possible repeated word" in various
comments.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Drop unused function batadv_hardif_remove_interfaces()

The function batadv_hardif_remove_interfaces was meant to remove all
interfaces which are currently in the list of known (compatible) hardifs
during module unload. But the function unregister_netdevice_notifier is
called in batadv_exit before batadv_hardif_remove_interfaces. This will
trigger NETDEV_UNREGISTER events for all available interfaces and in this
process remove all interfaces from batadv_hardif_list. And
batadv_hardif_remove_interfaces only operated on this (empty) list.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Introduce a configurable per interface hop penalty

In some setups multiple hard interfaces with similar link qualities
or throughput values are available. But people have expressed the desire
to consider one of them as a backup only.

Some creative solutions are currently in use: Such people are
configuring multiple batman-adv mesh/soft interfaces, wire them
together with some veth pairs and then tune the hop penalty to achieve
an effect similar to a tunable per interface hop penalty.

This patch introduces a new, configurable, per hard interface hop penalty
to simplify such setups.

Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Fix typos and grammar in documentation

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: use rcu_replace_pointer() where appropriate

In commit a63fc6b75cca ("rcu: Upgrade rcu_swap_protected() to
rcu_replace_pointer()") a new helper macro named rcu_replace_pointer() was
introduced to simplify code requiring to switch an rcu pointer to a new
value while extracting the old one.

Use rcu_replace_pointer() where appropriate to make code slimer.

Signed-off-by: Antonio Quartulli <a@unstable.cc>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Update copyright years for 2020

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Avoid free/alloc race when handling OGM buffer

Each slave interface of an B.A.T.M.A.N. IV virtual interface has an OGM
packet buffer which is initialized using data from netdevice notifier and
other rtnetlink related hooks. It is sent regularly via various slave
interfaces of the batadv virtual interface and in this process also
modified (realloced) to integrate additional state information via TVLV
containers.

It must be avoided that the worker item is executed without a common lock
with the netdevice notifier/rtnetlink helpers. Otherwise it can either
happen that half modified/freed data is sent out or functions modifying the
OGM buffer try to access already freed memory regions.

Reported-by: syzbot+0cc629f19ccb8534935b@syzkaller.appspotmail.com
Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: no need to check return value of debugfs_create functions

When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.

Because we don't care if debugfs works or not, this trickles back a bit
so we can clean things up by making some functions return void instead
of an error value that is never going to fail.

Cc: Marek Lindner <mareklindner@neomailbox.ch>
Cc: Simon Wunderlich <sw@simonwunderlich.de>
Cc: Antonio Quartulli <a@unstable.cc>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: b.a.t.m.a.n@lists.open-mesh.org
Cc: netdev@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[sven@narfation.org: drop unused variables]
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Fix duplicated OGMs on NETDEV_UP

The state of slave interfaces are handled differently depending on whether
the interface is up or not. All active interfaces (IFF_UP) will transmit
OGMs. But for B.A.T.M.A.N. IV, also non-active interfaces are scheduling
(low TTL) OGMs on active interfaces. The code which setups and schedules
the OGMs must therefore already be called when the interfaces gets added as
slave interface and the transmit function must then check whether it has to
send out the OGM or not on the specific slave interface.

But the commit f0d97253fb5f ("batman-adv: remove ogm_emit and ogm_schedule
API calls") moved the setup code from the enable function to the activate
function. The latter is called either when the added slave was already up
when batadv_hardif_enable_interface processed the new interface or when a
NETDEV_UP event was received for this slave interfac. As result, each
NETDEV_UP would schedule a new OGM worker for the interface and thus OGMs
would be send a lot more than expected.

Fixes: f0d97253fb5f ("batman-adv: remove ogm_emit and ogm_schedule API calls")
Reported-by: Linus Lüssing <linus.luessing@c0d3.blue>
Tested-by: Linus Lüssing <linus.luessing@c0d3.blue>
Acked-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Fix includes for *_MAX constants

The commit 54d50897d544 ("linux/kernel.h: split *_MAX and *_MIN macros into
<linux/limits.h>") moved the U32_MAX/INT_MAX/ULONG_MAX from linux/kernel.h
to linux/limits.h. Adjust the includes accordingly.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Drop license boilerplate

All files got a SPDX-License-Identifier with commit 7db7d9f369a4
("batman-adv: Add SPDX license identifier above copyright header"). All the
required information about the license conditions can be found in
LICENSES/.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Update copyright years for 2019

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Avoid WARN on net_device without parent in netns

It is not allowed to use WARN* helpers on potential incorrect input from
the user or transient problems because systems configured as panic_on_warn
will reboot due to such a problem.

A NULL return value of __dev_get_by_index can be caused by various problems
which can either be related to the system configuration or problems
(incorrectly returned network namespaces) in other (virtual) net_device
drivers. batman-adv should not cause a (harmful) WARN in this situation and
instead only report it via a simple message.

Fixes: b7eddd0b3950 ("batman-adv: prevent using any virtual device created on batman-adv as hard-interface")
Reported-by: syzbot+c764de0fcfadca9a8595@syzkaller.appspotmail.com
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Add inconsistent hardif netlink dump detection

The netlink dump functionality transfers a large number of entries from the
kernel to userspace. It is rather likely that the transfer has to
interrupted and later continued. During that time, it can happen that
either new entries are added or removed. The userspace could than either
receive some entries multiple times or miss entries.

Commit 670dc2833d14 ("netlink: advertise incomplete dumps") introduced a
mechanism to inform userspace about this problem. Userspace can then decide
whether it is necessary or not to retry dumping the information again.

The netlink dump functions have to be switched to exclusive locks to avoid
changes while the current message is prepared. And an external generation
sequence counter is introduced which tracks all modifications of the list.

Reported-by: Matthias Schiffer <mschiffer@universe-factory.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Move OGM rebroadcast stats to orig_ifinfo

B.A.T.M.A.N. IV requires the number of rebroadcast from a neighboring
originator. These statistics are gathered per interface which transmitted
the OGM (and then received it again). Since an originator is not interface
specific, a resizable array was used in each originator.

This resizable array had an entry for each interface and had to be resizes
(for all OGMs) when the number of active interface was modified. This could
cause problems when a large number of interface is added and not enough
continuous memory is available to allocate the array.

There is already a per interface originator structure "batadv_orig_ifinfo"
which can be used to store this information.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Fix debugfs path for renamed softif

batman-adv is creating special debugfs directories in the init
net_namespace for each created soft-interface (batadv net_device). But it
is possible to rename a net_device to a completely different name then the
original one.

It can therefore happen that a user registers a new batadv net_device with
the name "bat0". batman-adv is then also adding a new directory under
$debugfs/batman-adv/ with the name "wlan0".

The user then decides to rename this device to "bat1" and registers a
different batadv device with the name "bat0". batman-adv will then try to
create a directory with the name "bat0" under $debugfs/batman-adv/ again.
But there already exists one with this name under this path and thus this
fails. batman-adv will detect a problem and rollback the registering of
this device.

batman-adv must therefore take care of renaming the debugfs directories for
soft-interfaces whenever it detects such a net_device rename.

Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Fix debugfs path for renamed hardif

batman-adv is creating special debugfs directories in the init
net_namespace for each valid hard-interface (net_device). But it is
possible to rename a net_device to a completely different name then the
original one.

It can therefore happen that a user registers a new net_device which gets
the name "wlan0" assigned by default. batman-adv is also adding a new
directory under $debugfs/batman-adv/ with the name "wlan0".

The user then decides to rename this device to "wl_pri" and registers a
different device. The kernel may now decide to use the name "wlan0" again
for this new device. batman-adv will detect it as a valid net_device and
tries to create a directory with the name "wlan0" under
$debugfs/batman-adv/. But there already exists one with this name under
this path and thus this fails. batman-adv will detect a problem and
rollback the registering of this device.

batman-adv must therefore take care of renaming the debugfs directories
for hard-interfaces whenever it detects such a net_device rename.

Fixes: 5bc7c1eb44f2 ("batman-adv: add debugfs structure for information per interface")
Reported-by: John Soros <sorosj@gmail.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Update copyright years for 2018

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Fix internal interface indices types

batman-adv uses internal indices for each enabled and active interface.
It is currently used by the B.A.T.M.A.N. IV algorithm to identifify the
correct position in the ogm_cnt bitmaps.

The type for the number of enabled interfaces (which defines the next
interface index) was set to char. This type can be (depending on the
architecture) either signed (limiting batman-adv to 127 active slave
interfaces) or unsigned (limiting batman-adv to 255 active slave
interfaces).

This limit was not correctly checked when an interface was enabled and thus
an overflow happened. This was only catched on systems with the signed char
type when the B.A.T.M.A.N. IV code tried to resize its counter arrays with
a negative size.

The if_num interface index was only a s16 and therefore significantly
smaller than the ifindex (int) used by the code net code.

Both &batadv_hard_iface->if_num and &batadv_priv->num_ifaces must be
(unsigned) int to support the same number of slave interfaces as the net
core code. And the interface activation code must check the number of
active slave interfaces to avoid integer overflows.

Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Convert packet.h to uapi header

The header file is used by different userspace programs to inject packets
or to decode sniffed packets. It should therefore be available to them as
userspace header.

Also other components in the kernel (like the flow dissector) require
access to the packet definitions to be able to decode ETH_P_BATMAN ethernet
packets.

Signed-off-by: Sven Eckelmann <sven.eckelmann@openmesh.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

batman-adv: Add kernel-doc to externally visible functions

According to the kernel-doc documentation, externally visible functions
should be documented. This refers to all all non-static function which can
(and will) be used by functions in other sources files.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Use parentheses in function kernel-doc

The documentation describing kernel-doc comments for functions ("How to
format kernel-doc comments") uses parentheses at the end of the function
name. Using this format allows to use a consistent style when adding
documentation to a function and when referencing this function in a
different kernel-doc section.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: include gfp.h for GFP_* defines

The linux/gfp.h provides the GFP_ATOMIC and GFP_KERNEL define. It should
therefore be included instead of linux/fs.h.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Add SPDX license identifier above copyright header

The "Linux kernel licensing rules" require that each file has a SPDX
license identifier as first line (and sometimes as second line).

The FSFE REUSE practices [1] would also require the same tags but have no
restrictions on the placement in the source file. Using the "Linux kernel
licensing rules" is therefore also fulfilling the FSFE REUSE practices
requirements at the same time.

[1] https://reuse.software/practices/

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

net: Add extack to upper device linking

Add extack arg to netdev_upper_dev_link and netdev_master_upper_dev_link

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

batman-adv: Remove unnecessary parentheses

checkpatch introduced with commit 63b7c73ec86b ("checkpatch: add --strict
check for ifs with unnecessary parentheses") an additional test which
identifies some unnecessary parentheses.

Remove these unnecessary parentheses to avoid the warnings and to unify the
coding style slightly more.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: update copyright years for 2017

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Update wifi flags on upper link change

Things like VLANs don't have their link set when they are created. Thus
the wifi flags have to be evaluated later to fix their contents for the
link interface.

Signed-off-by: Sven Eckelmann <sven.eckelmann@open-mesh.com>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: retrieve B.A.T.M.A.N. V WiFi neighbor stats from real interface

Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
[sven.eckelmann@open-mesh.com: re-add batadv_get_real_netdev to take rtnl
semaphore for batadv_get_real_netdevice]
Signed-off-by: Sven Eckelmann <sven.eckelmann@open-mesh.com>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: additional checks for virtual interfaces on top of WiFi

In a few situations batman-adv tries to determine whether a given interface
is a WiFi interface to enable specific WiFi optimizations. If the interface
batman-adv has been configured with is a virtual interface (e.g. VLAN) it
would not be properly detected as WiFi interface and thus not benefit from
the special WiFi treatment.
This patch changes that by peeking under the hood whenever a virtual
interface is in play.

Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
[sven.eckelmann@open-mesh.com: integrate in wifi_flags caching, retrieve
namespace of link interface]
Signed-off-by: Sven Eckelmann <sven.eckelmann@open-mesh.com>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Cache the type of wifi device for each hardif

batman-adv is requiring the type of wifi device in different contexts. Some
of them can take the rtnl semaphore and some of them already have the
semaphore taken. But even others don't allow that the semaphore will be
taken.

The data has to be retrieved when the hardif is added to batman-adv because
some of the wifi information for an hardif will only be available with rtnl
lock. It can then be cached in the batadv_hard_iface and the functions
is_wifi_netdev and is_cfg80211_netdev can just compare the correct bits
without imposing extra locking requirements.

Signed-off-by: Sven Eckelmann <sven.eckelmann@open-mesh.com>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: refactor wifi interface detection

The ELP protocol requires cfg80211 to auto-detect the WiFi througput
to a given neighbor. Use batadv_is_cfg80211_netdev() to determine
whether or not an interface is eligible.

Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Sven Eckelmann <sven.eckelmann@open-mesh.com>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Return non-const ptr in batadv_getlink_net

The returned net_namespace of batadv_getlink_net may be used with functions
that potentially modify the struct. Thus it must return the pointer as
non-const like rtnl_link_ops::get_link_net does.

Signed-off-by: Sven Eckelmann <sven.eckelmann@open-mesh.com>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Revert "fix splat on disabling an interface"

The commit 9799c50372b2 ("batman-adv: fix splat on disabling an interface")
fixed a warning but at the same time broke the rtnl function add_slave for
devices which were temporarily removed.

batadv_softif_slave_add requires soft_iface of and hard_iface to be NULL
before it is allowed to be enslaved. But this resetting of soft_iface to
NULL in batadv_hardif_disable_interface was removed with the aforementioned
commit.

Reported-by: Julian Labus <julian@freifunk-rtk.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Acked-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Simple (re)broadcast avoidance

With this patch, (re)broadcasting on a specific interfaces is avoided:

* No neighbor: There is no need to broadcast on an interface if there
is no node behind it.

* Single neighbor is source: If there is just one neighbor on an
interface and if this neighbor is the one we actually got this
broadcast packet from, then we do not need to echo it back.

* Single neighbor is originator: If there is just one neighbor on
an interface and if this neighbor is the originator of this
broadcast packet, then we do not need to echo it back.

Goodies for BATMAN V:

("Upgrade your BATMAN IV network to V now to get these for free!")

Thanks to the split of OGMv1 into two packet types, OGMv2 and ELP
that is, we can now apply the same optimizations stated above to OGMv2
packets, too.

Furthermore, with BATMAN V, rebroadcasts can be reduced in certain
multi interface cases, too, where BATMAN IV cannot. This is thanks to
the removal of the "secondary interface originator" concept in BATMAN V.

Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: fix splat on disabling an interface

As long as there is still a reference for a hard interface held, there might
still be a forwarding packet relying on its attributes.

Therefore avoid setting hard_iface->soft_iface to NULL when disabling a hard
interface.

This fixes the following, potential splat:

batman_adv: bat0: Interface deactivated: eth1
batman_adv: bat0: Removing interface: eth1
cgroup: new mount options do not match the existing superblock, will be ignored
batman_adv: bat0: Interface deactivated: eth3
batman_adv: bat0: Removing interface: eth3
------------[ cut here ]------------
WARNING: CPU: 3 PID: 1986 at ./net/batman-adv/bat_iv_ogm.c:549 batadv_iv_send_outstanding_bat_ogm_packet+0x145/0x643 [batman_adv]
Modules linked in: batman_adv(O-) <...>
CPU: 3 PID: 1986 Comm: kworker/u8:2 Tainted: G W O 4.6.0-rc6+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet [batman_adv]
0000000000000000 ffff88001d93bca0 ffffffff8126c26b 0000000000000000
0000000000000000 ffff88001d93bcf0 ffffffff81051615 ffff88001f19f818
000002251d93bd68 0000000000000046 ffff88001dc04a00 ffff88001becbe48
Call Trace:
[<ffffffff8126c26b>] dump_stack+0x67/0x90
[<ffffffff81051615>] __warn+0xc7/0xe5
[<ffffffff8105164b>] warn_slowpath_null+0x18/0x1a
[<ffffffffa0356f24>] batadv_iv_send_outstanding_bat_ogm_packet+0x145/0x643 [batman_adv]
[<ffffffff8108b01f>] ? __lock_is_held+0x32/0x54
[<ffffffff810689a2>] process_one_work+0x2a8/0x4f5
[<ffffffff81068856>] ? process_one_work+0x15c/0x4f5
[<ffffffff81068df2>] worker_thread+0x1d5/0x2c0
[<ffffffff81068c1d>] ? process_scheduled_works+0x2e/0x2e
[<ffffffff81068c1d>] ? process_scheduled_works+0x2e/0x2e
[<ffffffff8106dd90>] kthread+0xc0/0xc8
[<ffffffff8144de82>] ret_from_fork+0x22/0x40
[<ffffffff8106dcd0>] ? __init_kthread_worker+0x55/0x55
---[ end trace 647f9f325123dc05 ]---

What happened here is, that there was still a forw_packet (here: a BATMAN IV
OGM) in the queue of eth3 with the forw_packet->if_incoming set to eth1 and the
forw_packet->if_outgoing set to eth3.

When eth3 is to be deactivated and removed, then this thread waits for the
forw_packet queued on eth3 to finish. Because eth1 was deactivated and removed
earlier and by that had forw_packet->if_incoming->soft_iface, set to NULL, the
splat when trying to send/flush the OGM on eth3 occures.

Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol")
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
[sven@narfation.org: Reduced size of Oops message]
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Keep batadv netdev when hardif disappears

Switch-like virtual interfaces like bridge or openvswitch don't destroy
itself when all their attached netdevices dissappear. Instead they only
remove the link to the unregistered device and keep working until they get
removed manually.

This has the benefit that all configurations for this interfaces are kept
and daemons reacting to rtnl events can just add new slave interfaces
without going through the complete configuration of the switch-like
netdevice.

Handling unregister events of client devices similar in batman-adv allows
users to drop their current workaround of dummy netdevices attached to
batman-adv soft-interfaces.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Place kref_get for hard_iface near use

It is hard to understand why the refcnt is increased when it isn't done
near the actual place the new reference is used. So using kref_get right
before the place which requires the reference and in the same function
helps to avoid accidental problems caused by incorrect reference counting.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Handle parent interfaces in a different netns

batman-adv tries to prevent the user from placing a batX soft
interface into another batman mesh as a hard interface. It does this
by walking up the devices list of parents and ensures they are all
none batX interfaces. iflink can point to an interface in a different
namespace, so also retrieve the parents name space when finding the
parent and use it when doing the comparison.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
[sven@narfation.org: Fix alignments, simplify parent netns retrieval]
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>

batman-adv: Revert "postpone sysfs removal when unregistering"

Postponing the removal of the interface breaks the expected behavior of
NETDEV_UNREGISTER and NETDEV_PRE_TYPE_CHANGE. This is especially
problematic when an interface is removed and added in quick succession.

This reverts commit 5bc44dc8458c ("batman-adv: postpone sysfs removal when
unregistering").

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: split routing API data structure in subobjects

The routing API data structure contains several function
pointers that can easily be grouped together based on the
component they work with.

Split the API in subobjects in order to improve definition readability.

At the same time, remove the "bat_" prefix from the API object and
its fields names. These are batman-adv private structs and there is no
need to always prepend such prefix, which only makes function invocations
much much longer.

Signed-off-by: Antonio Quartulli <a@unstable.cc>
Reviewed-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Fix bat_(iv|v) function declaration header

The bat_algo.h had some functions declared which were not part of the
bat_algo.c file. These are instead stored in bat_v.c and bat_iv_ogm.c. The
declaration should therefore be also in bat_v.h and bat_iv_ogm,h to make
them easier to find.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Consolidate logging related functions

There are several places in batman-adv which provide logging related
functions. These should be grouped together in the log.* files to make them
easier to find.

Reported-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Keep includes ordered by filename

It is easier to detect if a include is already there for a used
functionality when the includes are ordered. Using an alphabetic order
together with the grouping in commit 1e2c2a4fe4a5 ("batman-adv: Add
required includes to all files") makes includes better manageable.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: init ELP tweaking options only once

The ELP interval and throughput override interface settings are initialized
with default settings on every time an interface is added to a mesh.
This patch prevents this behavior by moving the configuration init to the
interface detection routine which runs only once per interface.

Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
[a@unstable.cc: move initialization to batadv_v_hardif_init]
Signed-off-by: Antonio Quartulli <a@unstable.cc>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: remove ogm_emit and ogm_schedule API calls

The ogm_emit and ogm_schedule API calls were rather tight to the
B.A.T.M.A.N. IV logic and therefore rather difficult to use
with other algorithm implementations.

Remove such calls and move the surrounding logic into the
B.A.T.M.A.N. IV specific code.

Signed-off-by: Antonio Quartulli <a@unstable.cc>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

batman-adv: Use bool as return type for boolean functions

It is easier to understand that the returned value of a specific function
doesn't have to be 0 when the functions was successful when the actual
return type is bool. This is especially true when all surrounding functions
with return type int use negative values to return the error code.

Reported-by: Nicholas Krause <xerofoify@gmail.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>

batman-adv: Use kref_get for hard_iface subfunctions

The callers of the functions using batadv_hard_iface objects already make
sure that they hold a valid reference. The subfunctions don't have
to check whether the reference counter is > 0 because this was checked by
the callers.

The kref_get function instead WARNs (with debug information) when the
reference counter would still be 0. This makes a bug in batman-adv better
visible because kref_get_unless_zero would have ignored this problem.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>

batman-adv: Increase hard_iface refcnt for ptype

The hard_iface is referenced in the packet_type for batman-adv. Increase
the refcounter of the hard_interface for it to have an explicit reference
for it in case this functionality gets refactorted and the currently
used implicit reference for it will be removed.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>

batman-adv: Create batman soft interfaces within correct netns.

When creating a soft interface, create it in the same netns as the
hard interface. Replace all references to init_net with the correct
name space for the interface being manipulated.

Suggested-by: Daniel Ehlers <danielehlers@mindeye.net>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Antonio Quartulli <a@unstable.cc>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>

batman-adv: B.A.T.M.A.N V - make sure iface is reactivated upon NETDEV_UP event

At the moment there is no explicit reactivation of an hard-interface
upon NETDEV_UP event. In case of B.A.T.M.A.N. IV the interface is
reactivated as soon as the next OGM is scheduled for sending, but this
mechanism does not work with B.A.T.M.A.N. V. The latter does not rely
on the same scheduling mechanism as its predecessor and for this reason
the hard-interface remains deactivated forever after being brought down
once.

This patch fixes the reactivation mechanism by adding a new routing API
which explicitly allows each algorithm to perform any needed operation
upon interface re-activation.

Such API is optional and is implemented by B.A.T.M.A.N. V only and it
just takes care of setting the iface status to ACTIVE

Signed-off-by: Antonio Quartulli <a@unstable.cc>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>

batman-adv: Deactivate TO_BE_ACTIVATED hardif on shutdown

The shutdown of an batman-adv interface can happen with one of its slave
interfaces still being in the BATADV_IF_TO_BE_ACTIVATED state. A possible
reason for it is that the routing algorithm BATMAN_V was selected and
batadv_schedule_bat_ogm was not yet called for this interface. This slave
interface still has to be set to BATADV_IF_INACTIVE or the batman-adv
interface will never reduce its usage counter and thus never gets shutdown.

This problem can be simulated via:

$ modprobe dummy
$ modprobe batman-adv routing_algo=BATMAN_V
$ ip link add bat0 type batadv
$ ip link set dummy0 master bat0
$ ip link set dummy0 up
$ ip link del bat0
unregister_netdevice: waiting for bat0 to become free. Usage count = 3

Reported-by: Matthias Schiffer <mschiffer@universe-factory.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>

batman-adv: Rename batadv_hardif *_free_ref function to *_put

The batman-adv source code is the only place in the kernel which uses the
*_free_ref naming scheme for the *_put functions. Changing it to *_put
makes it more consistent and makes it easier to understand the connection
to the *_get functions.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>

batman-adv: Avoid endless loop in bat-on-bat netdevice check

batman-adv checks in different situation if a new device is already on top
of a different batman-adv device. This is done by getting the iflink of a
device and all its parent. It assumes that this iflink is always a parent
device in an acyclic graph. But this assumption is broken by devices like
veth which are actually a pair of two devices linked to each other. The
recursive check would therefore get veth0 when calling dev_get_iflink on
veth1. And it gets veth0 when calling dev_get_iflink with veth1.

Creating a veth pair and loading batman-adv freezes parts of the system

ip link add veth0 type veth peer name veth1
modprobe batman-adv

An RCU stall will be detected on the system which cannot be fixed.

INFO: rcu_sched self-detected stall on CPU
1: (5264 ticks this GP) idle=3e9/140000000000001/0
softirq=144683/144686 fqs=5249
(t=5250 jiffies g=46 c=45 q=43)
Task dump for CPU 1:
insmod R running task 0 247 245 0x00000008
ffffffff8151f140 ffffffff8107888e ffff88000fd141c0 ffffffff8151f140
0000000000000000 ffffffff81552df0 ffffffff8107b420 0000000000000001
ffff88000e3fa700 ffffffff81540b00 ffffffff8107d667 0000000000000001
Call Trace:
<IRQ> [<ffffffff8107888e>] ? rcu_dump_cpu_stacks+0x7e/0xd0
[<ffffffff8107b420>] ? rcu_check_callbacks+0x3f0/0x6b0
[<ffffffff8107d667>] ? hrtimer_run_queues+0x47/0x180
[<ffffffff8107cf9d>] ? update_process_times+0x2d/0x50
[<ffffffff810873fb>] ? tick_handle_periodic+0x1b/0x60
[<ffffffff810290ae>] ? smp_trace_apic_timer_interrupt+0x5e/0x90
[<ffffffff813bbae2>] ? apic_timer_interrupt+0x82/0x90
<EOI> [<ffffffff812c3fd7>] ? __dev_get_by_index+0x37/0x40
[<ffffffffa0031f3e>] ? batadv_hard_if_event+0xee/0x3a0 [batman_adv]
[<ffffffff812c5801>] ? register_netdevice_notifier+0x81/0x1a0
[...]

This can be avoided by checking if two devices are each others parent and
stopping the check in this situation.

Fixes: b7eddd0b3950 ("batman-adv: prevent using any virtual device created on batman-adv as hard-interface")
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
[sven@narfation.org: rewritten description, extracted fix]
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>

batman-adv: Convert batadv_hard_iface to kref

batman-adv uses a self-written reference implementation which is just based
on atomic_t. This is less obvious when reading the code than kref and
therefore increases the change that the reference counting will be missed.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>

batman-adv: Drop reference to netdevice on last reference

The references to the network device should be dropped inside the release
function for batadv_hard_iface similar to what is done with the batman-adv
internal datastructures.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>

batman-adv: update copyright years for 2016

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>

batman-adv: Fix kerneldoc parsing of return description

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>

batman-adv: add list of unique single hop neighbors per hard-interface

Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>

batman-adv: Act on NETDEV_*_TYPE_CHANGE events

A network interface can change type. It may change from a type which
batman does not support, e.g. hdlc, to one it does, e.g. hdlc-eth.
When an interface changes type, it sends two notifications. Handle
these notifications.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: add possibility to pass information about upper device via notifier

Sometimes the drivers and other code would find it handy to know some
internal information about upper device being changed. So allow upper-code
to pass information down to notifier listeners during linking.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: propagate upper priv via netdev_master_upper_dev_link

Eliminate netdev_master_upper_dev_link_private and pass priv directly as
a parameter of netdev_master_upper_dev_link.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

batman-adv: Add lower layer needed_(head|tail)room to own ones

The maximum of hard_header_len and maximum of all needed_(head|tail)room of
all slave interfaces of a batman-adv device must be used to define the
batman-adv device needed_(head|tail)room. This is required to avoid too
small buffer problems when these slave devices try to send the encapsulated
packet in a tx path without the possibility to resize the skbuff.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>

batman-adv: don't access unregistered net_device object

In batadv_hardif_disable_interface() there is a call to
batadv_softif_destroy_sysfs() which in turns invokes
unregister_netdevice() on the soft_iface.
After this point we cannot rely on the soft_iface object
anymore because it might get free'd by the netdev periodic
routine at any time.

For this reason the netdev_upper_dev_unlink(.., soft_iface) call
is moved before the invocation of batadv_softif_destroy_sysfs() so
that we can be sure that the soft_iface object is still valid.

Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>

batman-adv: Add required includes to all files

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 <mpa@pengutronix.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>

batman-adv: update copyright years for 2015

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>

dev: introduce dev_get_iflink()

The goal of this patch is to prepare the removal of the iflink field. It
introduces a new ndo function, which will be implemented by virtual interfaces.

There is no functional change into this patch. All readers of iflink field
now call dev_get_iflink().

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

batman: fix a bogus warning from batadv_is_on_batman_iface()

batman tries to search dev->iflink to check if it's a batman interface,
but ->iflink could be 0, which is not a valid ifindex. It should just
avoid iflink == 0 case.

Reported-by: Jet Chen <jet.chen@intel.com>
Tested-by: Jet Chen <jet.chen@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Antonio Quartulli <antonio@open-mesh.com>
Cc: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

batman-adv: fix soft-interface MTU computation

The current MTU computation always returns a value
smaller than 1500bytes even if the real interfaces
have an MTU large enough to compensate the batman-adv
overhead.

Fix the computation by properly returning the highest
admitted value.

Introduced by a19d3d85e1b854e4a483a55d740a42458085560d
("batman-adv: limit local translation table max size")

Reported-by: Russell Senior <russell@personaltelco.net>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>

batman-adv: use __dev_get_by_index instead of dev_get_by_index to find interface

The following call chains indicate that batadv_is_on_batman_iface()
is always under rtnl_lock protection as call_netdevice_notifier()
is protected by rtnl_lock. So if __dev_get_by_index() rather than
dev_get_by_index() is used to find interface handler in it, this
would help us avoid to change interface reference counter.

call_netdevice_notifier()
batadv_hard_if_event()
batadv_hardif_add_interface()
batadv_is_valid_iface()
batadv_is_on_batman_iface()

Cc: Antonio Quartulli <antonio@meshcoding.com>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Antonio Quartulli <antonio@meshcoding.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

batman-adv: update copyright years for 2014

Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>

batman-adv: add debugfs structure for information per interface

To show information per interface, add a debugfs hardif structure
similar to the system in sysfs. Hard interface folders will be created
in "$debugfs/batman-adv/". Files are not yet added.

Signed-off-by: Simon Wunderlich <simon@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>

batman-adv: remove FSF address from GPL disclaimer

As suggested by checkpatch, remove all the references to the
FSF address since the kernel already has one reference in
its documentation.

In this way it is easier to update it in case of future
changes.

Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>

batman-adv: invoke dev_get_by_index() outside of is_wifi_iface()

Upcoming changes need to perform other checks on the
incoming net_device struct.

To avoid performing dev_get_by_index() for each and every
check, it is better to move it outside of is_wifi_iface()
and search the netdev object once only.

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>

batman-adv: send GW_DEL event in case of soft-iface destruction

In case of soft_iface destruction send a GW DEL event to
userspace so that applications which are listening for GW
events are informed about the lost of connectivity and can
react accordingly.

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>

batman-adv: limit local translation table max size

The local translation table size is limited by what can be
transferred from one node to another via a full table request.

The number of entries fitting into a full table request depend
on whether the fragmentation is enabled or not. Therefore this
patch introduces a max table size check and refuses to add
more local clients when that size is reached. Moreover, if the
max full table packet size changes (MTU change or fragmentation
is disabled) the local table is downsized instantaneously.

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Acked-by: Antonio Quartulli <ordex@autistici.org>

batman-adv: add per VLAN interface attribute framework

Since batman-adv is now fully VLAN-aware, a proper framework
able to handle per-vlan-interface attributes is needed.

Those attributes will affect the associated VLAN interface
only, rather than the real soft_iface (which would result
in every vlan interface having the same attribute
configuration).

To make the code simpler and easier to extend, attributes
associated to the standalone soft_iface are now treated
like belonging to yet another vlan having a special vid.
This vid is different from the others because it is made up
by all zeros and the VLAN_HAS_TAG bit is not set.

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>

batman-adv: consider network coding overhead when calculating required mtu

The module prints a warning when the MTU on the hard interface is too
small to transfer payload traffic without fragmentation. The required
MTU is calculated based on the encapsulation header size. If network
coding is compild into the module its header size is taken into
account as well.

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>

batman-adv: use htons when possible

When comparing a network ordered value with a constant, it
is better to convert the constant at compile time by means
of htons() instead of converting the value at runtime using
ntohs().

This refactoring may slightly improve the code performance.

Moreover substitute __constant_htons() with htons() since
the latter increase readability and it is smart enough to be
as efficient as the former

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Acked-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>

batman-adv: Remove old fragmentation code

Remove the existing fragmentation code before adding the new version
and delete unicast.{h,c}.

batadv_unicast_send_skb() is moved to send.c and renamed to
batadv_send_skb_unicast().

fragmentation entry in sysfs (bat_priv->fragmentation) is kept for use in
the new fragmentation code.

BATADV_UNICAST_FRAG packet type is renamed to BATADV_FRAG for use in the
new fragmentation code.

Signed-off-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>

batman-adv: remove vis functionality

This is replaced by a userspace program, we don't need this
functionality to bloat the kernel.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>

batman-adv: don't initialise batman_iv private members in hard-interface.c

hard-interface.c has to do not contain any routing algorithm
specific code.

Allocate the hard-interface with kzalloc() and remove any
useless and algorithm specific member initialisation

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>

batman-adv: send each broadcast only once on non-wireless interfaces

While it makes sense to send each broadcast thrice on 802.11 (WLAN) interfaces
as broadcasts are often unreliable on these, there is no reason to do so on
other interface types.

The increased the overhead can be harmful on low-bandwidth links like VPN
connections over slow internet lines, therefore it is better to reduce the
number of broadcast packets sent on non-wireless links to one.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

batman-adv: split batadv_is_wifi_iface() into two functions

Previously batadv_is_wifi_iface() did two things at once: looking up a
net_device from an interface index, and determining if it is a wifi device.

The second part is useful itself when the caller already has a net_device
reference.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

net: pass info struct via netdevice notifier

So far, only net_device * could be passed along with netdevice notifier
event. This patch provides a possibility to pass custom structure
able to provide info that event listener needs to know.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>

v2->v3: fix typo on simeth
shortened dev_getter
shortened notifier_info struct name
v1->v2: fix notifier_call parameter in call_netdevice_notifier()
Signed-off-by: David S. Miller <davem@davemloft.net>

batman-adv: free an hard-interface before adding it

When adding a new hard interface (e.g. wlan0) to a soft interface (e.g. bat0)
and the former is already enslaved in another virtual interface (e.g. a software
bridge) batman-adv has to free it first and then continue with the adding
mechanism.

In this way the behaviour becomes consistent with what "ip link set master"
does. At the moment batman-adv enslaves the hard interface without checking for
the master device, possibly causing strange behaviours which are never wanted by
the users.

Reported-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>

batman-adv: Allow to modify slaves of soft-interfaces through rntl_link

The sysfs configuration interface of batman-adv to add/remove slaves of an
soft-iface is not deadlock free and doesn't follow the currently common way to
modify slaves of an interface.

An additional configuration interface though rtnl_link is introduced which
provides easy device adding/removing with tools like "ip":
$ ip link set dev eth0 master bat0
$ ip link set dev eth0 nomaster

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Acked-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

batman-adv: rename batadv_softif_destroy to reflect sysfs use case

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
CC: Sven Eckelmann <sven@narfation.org>
Acked-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

batman-adv: Don't always delete softif when last slave was removed

batman-adv has an unusual way to manage softinterfaces. These will be created
automatically when a user writes to the batman-adv/mesh_iface file in sysfs and
removed when no slave device exists anymore.

This behaviour cannot be changed without breaking compatibility with existing
code. Instead other interfaces should be able to slightly reduce this behaviour
and provide a more common reaction to a removal of a slave interface.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Acked-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

batman-adv: Move soft-interface initialization to ndo_init

The initialization of an net_device object should be done in the
init/constructor function and not from the outside after the register_netdevice
was done to avoid race conditions.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Acked-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: 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>

batman-adv: postpone sysfs removal when unregistering

When processing the unregister notify for a hard interface, removing
the sysfs files may lead to a circular deadlock (rtnl mutex <->
s_active).

To overcome this problem, postpone the sysfs removal in a worker.

Reported-by: Sasha Levin <sasha.levin@oracle.com>
Reported-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

batman-adv: use ETH_P_BATMAN

The ETH_P_BATMAN ethertype is now defined kernel-wide. Use it instead
of the private BATADV_ETH_P_BATMAN define.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>

batman-adv: prevent using any virtual device created on batman-adv as hard-interface

Any virtual device created on top of a batman-adv mesh interface must be
prevented to be used to create a new mesh network (this would lead to an
unwanted batman-over-batman configuration)

Signed-off-by: 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>

batman-adv: split hard_iface struct for each routing protocol

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

batman-adv: Split batadv_priv in sub-structures for features

The structure batadv_priv grows everytime a new feature is introduced. It gets
hard to find the parts of the struct that belongs to a specific feature. This
becomes even harder by the fact that not every feature uses a prefix in the
member name.

The variables for bridge loop avoidence, gateway handling, translation table
and visualization server are moved into separate structs that are included in
the bat_priv main struct.

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

batman-adv: check batadv_orig_hash_add_if() return code

If this call fails, some of the orig_nodes spaces may have been
resized for the increased number of interface, and some may not.
If we would just continue with the larger number of interfaces,
this would lead to access to not allocated memory later.

We better check the return code, and don't add the interface if
no memory is available. OTOH, keeping some of the orig_nodes
with too much memory allocated should hurt no one (except for
a few too many bytes allocated).

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

batman-adv: Fix alignment after opened parentheses

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

batman-adv: Remove bat_ prefix from bat_{debugfs, sysfs}.{c, h}

The "bat_" prefix in the source files implementing the batman-adv sysfs and
debugfs interface doesn't have a special meaning and are only used by these
files and files that implement the actual B.A.T.M.A.N. path finding algorithm.

The prefix is better suited to mark files that are used to implement the main
part of the path finding. All other files should not use it and therefore gets
renamed.

Signed-off-by: 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>

batman-adv: Prefix packet structs with batadv_

Reported-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>

batman-adv: Prefix hard-interface enum with BATADV_

Reported-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: 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>

batman-adv: Prefix types defines with BATADV_

Reported-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: 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>

batman-adv: Prefix remaining function like macros with batadv_

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

batman-adv: Prefix hard-interface 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>

batman-adv: Prefix main 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>

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>

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>

batman-adv: Prefix main 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>

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>

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>

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>

batman-adv: Prefix hard-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>

batman-adv: Prefix bridge_loop_avoidance 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>

batman-adv: Prefix bat_sysfs 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>

batman-adv: Return error codes instead of -1 on failures

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

batman-adv: use shorter pr_warn instead of pr_warning

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

batman-adv: refactoring API: find generalized name for bat_ogm_update_mac callback

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

batman-adv: introduce packet type handler array for incoming packets

The packet handler array replaces the growing switch statement, thus
dealing with incoming packets in a more efficient way. It also adds
to possibility to register packet handlers on the fly.

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Acked-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

batman-adv: use ETH_HLEN instead of sizeof(struct ethhdr)

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: Antonio Quartulli <ordex@autistici.org>

batman-adv: mark existing ogm variables as batman iv

The coming protocol changes also will have a part called "OGM". That
makes it necessary to introduce a distinction in the code base.

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

batman-adv: refactoring API: find generalized name for bat_ogm_init_primary callback

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

batman-adv: handle routing code initialization properly

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

batman-adv: add iface_disable() callback to routing API

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

batman-adv: refactoring API: find generalized name for bat_ogm_init callback

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

batman-adv: move ogm initialization into the proper function

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

batman-adv: add basic bridge loop avoidance code

This second version of the bridge loop avoidance for batman-adv
avoids loops between the mesh and a backbone (usually a LAN).

By connecting multiple batman-adv mesh nodes to the same ethernet
segment a loop can be created when the soft-interface is bridged
into that ethernet segment. A simple visualization of the loop
involving the most common case - a LAN as ethernet segment:

node1 <-- LAN --> node2
| |
wifi <-- mesh --> wifi

Packets from the LAN (e.g. ARP broadcasts) will circle forever from
node1 or node2 over the mesh back into the LAN.

With this patch, batman recognizes backbone gateways, nodes which are
part of the mesh and backbone/LAN at the same time. Each backbone
gateway "claims" clients from within the mesh to handle them
exclusively. By restricting that only responsible backbone gateways
may handle their claimed clients traffic, loops are effectively
avoided.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

batman-adv: Ignore 80-chars per line limits for strings

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

batman-adv: Fix indentation of multiline statements

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

batman-adv: Update copyright years

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

batman-adv: convert batman iv algorithm to use dynamic infrastructure

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

batman-adv: warn if added interface is part of a bridge

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

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>

batman-adv: Remove unnecessary OOM logging messages

Removing unnecessary messages saves code and text.

Site specific OOM messages are duplications of a generic MM
out of memory message and aren't really useful, so just
delete them.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>

batman-adv: agglomerate all batman iv ogm sending functions in the batman iv file

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: Marek Lindner <lindner_marek@yahoo.de>

batman-adv: move routing packet initialization into corresponding file

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

batman-adv: agglomerate all batman iv ogm processing functions in a single file

In preparation of the upcoming improved routing algorithm the code based has
to be re-organized to allow choosing the routing algorithm at compile time.

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

batman-adv: rename all instances of batman_packet to batman_ogm_packet

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

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

batman-adv: detect clients connected through a 802.11 device

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: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>

batman-adv: correct several typ0s in the comments

Several typos have been corrected and some sentences have been rephrased

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>

batman-adv: improved roaming mechanism

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

batman-adv: use NO_FLAGS define instead of hard-coding 0

The definition NO_FLAGS was introduced to make the code more
readable and shall be used to initialize flag fields.

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

net: Remove unnecessary semicolons

Semicolons are not necessary after switch/while/for/if braces
so remove them.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

batman-adv: Use rcu_dereference_protected by update-side

Usually rcu_dereference isn't necessary in situations were the
RCU-protected data structure cannot change, but sparse and lockdep still
need a similar functionality for analysis. rcu_dereference_protected
implements the reduced version which should be used to support the
dynamic and static analysis.

Signed-off-by: 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>

batman-adv: Remove explicit casts cast from void* for store

It is not necessary to cast a void* to the pointer type when we just
store it and don't want to do pointer arithmetic before the actual
assignment.

Signed-off-by: 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>

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>

batman-adv: Remove unnecessary hardif_list_lock

hardif_list_lock is unneccessary because we already ensure that no
multiple admin operations can take place through rtnl_lock.
hardif_list_lock only adds additional overhead and complexity.

Critical functions now check whether they are called with rtnl_lock
using ASSERT_RTNL.

It indirectly fixes the problem that orig_hash_del_if() expects that
only one interface is deleted from hardif_list at a time, but
hardif_remove_interfaces() removes all at once and then calls
orig_hash_del_if().

Reported-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>

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>

batman-adv: Disallow regular interface as mesh device

When trying to associate a net_device with another net_device which
already exists, batman-adv assumes that this interface is a fully
initialized batman mesh interface without checking it. The behaviour
when accessing data behind netdev_priv of a random net_device is
undefined and potentially dangerous.

Reported-by: Linus Lüssing <linus.luessing@ascom.ch>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>

batman-adv: rename batman_if struct to hard_iface

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

batman-adv: rename global if_list to hardif_list

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: Marek Lindner <lindner_marek@yahoo.de>

batman-adv: separate ethernet comparing calls from hash functions

Note: The function compare_ether_addr() provided by the Linux kernel
requires aligned memory.

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

batman-adv: Correct rcu refcounting for batman_if

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>

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>

batman-adv: Update copyright years

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

batman-adv: Remove declaration of batman_skb_recv

batman_skb_recv can be defined in hard-interface.c as static because it is
never used outside of that file.

Signed-off-by: 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>