With this patch a node sends IPv4 multicast packets to nodes which
have a BATADV_MCAST_WANT_ALL_IPV4 flag set and IPv6 multicast packets
to nodes which have a BATADV_MCAST_WANT_ALL_IPV6 flag set, too.
Why is this needed? There are scenarios involving bridges where
multicast report snooping and multicast TT announcements are not
sufficient, which would lead to packet loss for some nodes otherwise:
MLDv1 and IGMPv1/IGMPv2 have a suppression mechanism
for multicast listener reports. When we have an MLDv1/IGMPv1/IGMPv2
querier behind a bridge then our snooping bridge is potentially not
going to see any reports even though listeners exist because according
to RFC4541 such reports are only forwarded to multicast routers:
-----------------------------------------------------------
---------------
{Querier}---|Snoop. Switch|----{Listener}
---------------
\ ^
-------
| br0 | < ???
-------
\
_-~---~_
_-~/ ~-_
~ batman-adv \-----{Sender}
\~_ cloud ~/
-~~__-__-~_/
I) MLDv1 Query: {Querier} -> flooded
II) MLDv1 Report: {Listener} -> {Querier}
-> br0 cannot detect the {Listener}
=> Packets from {Sender} need to be forwarded to all
detected listeners and MLDv1/IGMPv1/IGMPv2 queriers.
-----------------------------------------------------------
Note that we do not need to explicitly forward to MLDv2/IGMPv3 queriers,
because these protocols have no report suppression: A bridge has no
trouble detecting MLDv2/IGMPv3 listeners.
Even though we do not support bridges yet we need to provide the
according infrastructure already to not break compatibility later.
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
With this patch a node may additionally perform the dropping or
unicasting behaviour for a link-local IPv4 and link-local-all-nodes
IPv6 multicast packet, too.
The extra counter and BATADV_MCAST_WANT_ALL_UNSNOOPABLES flag is needed
because with a future bridge snooping support integration a node with a
bridge on top of its soft interface is not able to reliably detect its
multicast listeners for IPv4 link-local and the IPv6
link-local-all-nodes addresses anymore (see RFC4541, section 2.1.2.2
and section 3).
Even though this new flag does make "no difference" now, it'll ensure
a seamless integration of multicast bridge support without needing to
break compatibility later.
Also note, that even with multicast bridge support it won't be possible
to optimize 224.0.0.x and ff02::1 towards nodes with bridges, they will
always receive these ranges.
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
With this patch a multicast packet is not always simply flooded anymore,
the behaviour for the following cases is changed to reduce
unnecessary overhead:
If all nodes within the horizon of a certain node have signalized
multicast listener announcement capability then an IPv6 multicast packet
with a destination of IPv6 link-local scope (excluding ff02::1) coming
from the upstream of this node...
* ...is dropped if there is no according multicast listener in the
translation table,
* ...is forwarded via unicast if there is a single node with interested
multicast listeners
* ...and otherwise still gets flooded.
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
If the soft interface of a node is not part of a bridge then a node
announces a new multicast TVLV: The existence of this TVLV
signalizes that this node is announcing all of its multicast listeners
via the translation table infrastructure.
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
Reported-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
On some architectures ether_addr_copy() is slightly faster
than memcpy() therefore use the former when possible.
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Our .ndo_start_xmit handler (batadv_interface_tx()) can rely on having
the skb mac header pointer set correctly since the following commit
present in kernels >= 3.9:
"net: reset mac header in dev_start_xmit()" (6d1ccff627)
Therefore we can safely use eth_hdr() and vlan_eth_hdr() instead of
skb->data now, which spares us some ugly type casts.
At the same time set the mac_header in batadv_dat_snoop_incoming_arp_request()
before sending the skb along the TX path.
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
If the same interface is used for sending and receiving, there might be
throughput degradation on half-duplex interfaces such as WiFi. Add a
penalty if the same interface is used to reflect this problem in the
metric. At the same time, change the hop penalty from 30 to 15 so there
will be no change for single wifi mesh network. the effective hop
penalty will stay at 30 due to the new wifi penalty for these networks.
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>
If a broadcast packet is coming from a client marked as
isolated, then mark the skb using the isolation mark so
that netfilter (or any other application) can recognise
them.
The mark is written in the skb based on the mask value:
only bits set in the mask are substitued by those in the
mark value
Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
A client sending packets which mark matches the value
configured via sysfs has to be identified as isolated using
the TT_CLIENT_ISOLA flag.
The match is mask based, meaning that only bits set in the
mask are compared with those in the mark value.
If the configured mask is equal to 0 no operation is
performed.
Such flag is then advertised within the classic client
announcement mechanism.
Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
This attribute can be used to set and read the value and the
mask of the skb mark which will be used to classify the
source non-mesh client as ISOLATED. In this way a client can
be advertised as such and the mark can potentially be
restored at the receiving node before delivering the skb.
This can be helpful for creating network wide netfilter
policies.
This sysfs file expects a string of the shape "$mark/$mask".
Where $mark has to be a 32-bit number in any base, while
$mask must be a 32bit mask expressed in hex base. Only bits
in $mark covered by the bitmask are really stored.
Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
In different situations it is possible that the DHCP server
or client uses broadcast Ethernet frames to send messages
to each other. The GW component in batman-adv takes care of
using bat-unicast packets to bring broadcast DHCP
Discover/Requests to the "best" server.
On the way back the DHCP server usually sends unicasts,
but upon client request it may decide to use broadcasts as
well.
This patch improves the GW component so that it now snoops
and sends as unicast all the DHCP packets, no matter if they
were generated by a DHCP server or client.
Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
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>
When batadv_get_vid() is invoked in interface_rx() the
batman-adv header has already been removed, therefore
the header_len argument has to be 0.
Introduced by c018ad3de6
("batman-adv: add the VLAN ID attribute to the TT entry")
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
If an interface enslaved into batman-adv is a bridge (or a
virtual interface built on top of a bridge) the nf_bridge
member of the skbs reaching the soft-interface is filled
with the state about "netfilter bridge" operations.
Then, if one of such skbs is locally delivered, the nf_bridge
member should be cleaned up to avoid that the old state
could mess up with other "netfilter bridge" operations when
entering a second bridge.
This is needed because batman-adv is an encapsulation
protocol.
However at the moment skb->nf_bridge is not released at all
leading to bogus "netfilter bridge" behaviours.
Fix this by cleaning the netfilter state of the skb before
it gets delivered to the upper layer in interface_rx().
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
The size of the batadv_header of 3 is problematic on some architectures
which automatically pad all structures to a 32 bit boundary. To not lose
performance by packing this struct, better embed it into the various
host structures.
Reported-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
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>
With this patch the functions batadv_send_skb_unicast() and
batadv_send_skb_unicast_4addr() are further refined into
batadv_send_skb_via_tt(), batadv_send_skb_via_tt_4addr() and
batadv_send_skb_via_gw(). This way we avoid any "guessing" about where to send
a packet in the unicast forwarding methods and let the callers decide.
This is going to be useful for the upcoming multicast related patches in
particular.
Further, the return values were polished a little to use the more
appropriate NET_XMIT_* defines.
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Acked-by: Antonio Quartulli <antonio@meshcoding.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
AP isolation has to be enabled on one VLAN interface only.
This patch moves the AP isolation attribute to the per-vlan
interface attribute set, enabling it to have a different
value depending on the selected vlan.
Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Each VLAN can now have its own set of attributes which are
exported through a new subfolder in the sysfs tree.
Each VLAN created on top of a soft_iface will have its own
subfolder.
The subfolder is named "vlan%VID" and it is created inside
the "mesh" sysfs folder belonging to batman-adv.
Attributes corresponding to the untagged LAN are stored in
the root sysfs folder as before.
This patch also creates all the needed macros and data
structures to easily handle new VLAN spacific attributes.
Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
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>
To make the translation table code VLAN-aware, each entry
must carry the VLAN ID which it belongs to. This patch adds
such attribute to the related TT structures.
Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
We do not actually need to set any rx filters for the virtual batman
soft interface. However a dummy handler enables a user to set static
multicast listeners for instance.
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
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>
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>
Non-broadcast packets larger than MTU are fragmented and sent with
an encapsulating header. Up to 16 fragments are supported, which are
sent in reverse order on the wire to allow minimal memory copying when
creating fragments.
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>
Fragments arriving at their destination are buffered for later merge.
Merged packets are passed to the main receive function as had they never
been fragmented.
Fragments are forwarded without merging if the MTU of the outgoing
interface is smaller than the size of the merged packet.
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>
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>
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>
Prior to this patch batman-adv read the advertised uplink bandwidth
from userspace and compressed this information into a single byte
called "gateway class".
Now the download & upload bandwidth information is sent as-is. No
userspace change is necessary since the sysfs API always allowed
to specify a bandwidth.
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Spyros Gasteratos <morfeas3000@gmail.com>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
When receiving or sending a packet a packet on a VLAN, the
vid has to be marked with the TAG flag in order to make any
component in batman-adv understand that the packet is coming
from a really tagged network.
This fix the Bridge Loop Avoidance behaviour which was not
able to send announces over VLAN interfaces.
Introduced by 0b1da1765fdb00ca5d53bc95c9abc70dfc9aae5b
("batman-adv: change VID semantic in the BLA code")
Signed-off-by: Antonio Quartulli <antonio@open-mesh.org>
Acked-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
The skb priority field may help the wireless driver to choose the right
queue (e.g. WMM queues). This should be set in batman-adv, as this
information is only available here.
This patch adds support for IPv4/IPv6 DS fields and VLAN PCP. Note that
only VLAN PCP is used if a VLAN header is present. Also initially set
TC_PRIO_CONTROL only for self-generated packets, and keep the priority
set by higher layers.
Signed-off-by: Simon Wunderlich <simon@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
There are several functions which might reallocate skb data. Currently
some places keep reusing their old ethhdr pointer regardless of whether
they became invalid after such a reallocation or not. This potentially
leads to kernel paging errors.
This patch fixes these by refetching the ethdr pointer after the
potential reallocations.
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
In order to make batman-adv fully vlan aware later, the
semantic used for variables storing the VLAN ID values has
to be changed in order to be adapted to the new one which
will be used batman-adv wide.
In particular, the VID has to be an "_unsigned_ short int"
and its 4 MSB will be used as a flag bitfield, while the
remaining 12 bits are used to store the real VID value
Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Acked-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Instead of casting the result of skb_mac_header() to
"struct ethhdr *" every time, the eth_hdr inline function
can be use to beautify the code and improve its readability.
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
On errors in batadv_mesh_init(), bat_counters will be freed in both
batadv_mesh_free() and batadv_softif_init_late(). This patch fixes this
by returning earlier from batadv_softif_init_late() in case of errors in
batadv_mesh_init() and by setting bat_counters to NULL after freeing.
Signed-off-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
batadv_mesh_free() schedules some RCU callbacks which need the bat_priv struct
to do their jobs, while free_netdev(), which is called immediately after, is
destroying the private data.
Put an rcu_barrier() in the middle so that free_netdev() is invoked only after
all the callbacks returned.
This bug has been introduced by ab8f433dd39be94e8617cff2dfe9f7eca162eb15
("batman-adv: Move deinitialization of soft-interface to destructor")
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
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>
The sysfs configuration interface of batman-adv to add/remove soft-interfaces
is not deadlock free and doesn't follow the currently common way to create new
virtual interfaces.
An additional interface though rtnl_link is introduced which provides easy device
creation/deletion with tools like "ip":
$ ip link add dev bat0 type batadv
$ ip link del dev bat0
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
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>
The deinitialization of the soft-interface created in ndo_init/constructor
should be done in the destructor and not directly before calling
unregister_netdevice
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>
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>
When receiving a network coded packet, the decoding buffer is searched
for a packet to use for decoding. The source, destination, and crc32 from
the coded packet is used to identify the wanted packet. The decoded
packet is passed to the usual unicast receiver function, as had it never
been network coded.
Signed-off-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
To be able to decode a network coded packet, a node must already know
one of the two coded packets. This is done by buffering skbs before
transmission and buffering packets sniffed with promiscuous mode from
other hosts.
Packets are kept in a buffer similar to the one with forward-skbs: A
hash table, where each entry, which corresponds to a src-dst pair, has a
linked list packets.
Signed-off-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Before adding forward-skbs to the coding buffer, the buffer is searched
for a potential coding opportunity. If one is found, the two packets are
network coded and transmitted right away. If not, the forward-skb is
added to the buffer.
Network coded packets are transmitted with information about the two
receivers and the two coded packets. The first receiver is given by the
MAC header, while the second is given in the payload/bat-header. The
second receiver uses promiscuous mode to receive the packet and check
the second destination.
Signed-off-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Network coding exploits the 802.11 shared medium to allow multiple
packets to be sent in a single transmission. In brief, a relay can XOR
two packets, and send the coded packet to two destinations. The
receivers can decode one of the original packets by XOR'ing the coded
packet with the other original packet. This will lead to increased
throughput in topologies where two packets cross one relay.
In a simple topology with three nodes, it takes four transmissions
without network coding to get one packet from Node A to Node B and one
from Node B to Node A:
1. Node A ---- p1 ---> Node R Node B
2. Node A Node R <--- p2 ---- Node B
3. Node A <--- p2 ---- Node R Node B
4. Node A Node R ---- p1 ---> Node B
With network coding, the relay only needs one transmission, which saves
us one slot of valuable airtime:
1. Node A ---- p1 ---> Node R Node B
2. Node A Node R <--- p2 ---- Node B
3. Node A <- p1 x p2 - Node R - p1 x p2 -> Node B
The same principle holds for a topology including five nodes. Here the
packets from Node A and Node B are overheard by Node C and Node D,
respectively. This allows Node R to send a network coded packet to save
one transmission:
Node A Node B
| \ / |
| p1 p2 |
| \ / |
p1 > Node R < p2
| |
| / \ |
| p1 x p2 p1 x p2 |
v / \ v
/ \
Node C < > Node D
More information is available on the open-mesh.org wiki[1].
This patch adds the initial code to support network coding in
batman-adv. It sets up a worker thread to do house keeping and adds a
sysfs file to enable/disable network coding. The feature is disabled by
default, as it requires a wifi-driver with working promiscuous mode, and
also because it adds a small delay at each hop.
[1] http://www.open-mesh.org/projects/batman-adv/wiki/Catwoman
Signed-off-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
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>
Linus Lüssing