The commit d2a8ebbf ("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: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

We currently have two code paths for broadcast packets:

A) self-generated, via batadv_interface_tx()->
   batadv_send_bcast_packet().
B) received/forwarded, via batadv_recv_bcast_packet()->
   batadv_forw_bcast_packet().

For A), self-generated broadcast packets:

The only modifications to the skb data is the ethernet header which is
added/pushed to the skb in
batadv_send_broadcast_skb()->batadv_send_skb_packet(). However before
doing so, batadv_skb_head_push() is called which calls skb_cow_head() to
unshare the space for the to be pushed ethernet header. So for this
case, it is safe to use skb clones.

For B), received/forwarded packets:

The same applies as in A) for the to be forwarded packets. Only the
ethernet header is added. However after (queueing for) forwarding the
packet in batadv_recv_bcast_packet()->batadv_forw_bcast_packet(), a
packet is additionally decapsulated and is sent up the stack through
batadv_recv_bcast_packet()->batadv_interface_rx().

Protocols higher up the stack are already required to check if the
packet is shared and create a copy for further modifications. When the
next (protocol) layer works correctly, it cannot happen that it tries to
operate on the data behind the skb clone which is still queued up for
forwarding.
Co-authored-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

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

We currently have two code paths for broadcast packets:

A) self-generated, via batadv_interface_tx()->
   batadv_send_bcast_packet().
B) received/forwarded, via batadv_recv_bcast_packet()->
   batadv_forw_bcast_packet().

For A), self-generated broadcast packets:

The only modifications to the skb data is the ethernet header which is
added/pushed to the skb in
batadv_send_broadcast_skb()->batadv_send_skb_packet(). However before
doing so, batadv_skb_head_push() is called which calls skb_cow_head() to
unshare the space for the to be pushed ethernet header. So for this
case, it is safe to use skb clones.

For B), received/forwarded packets:

The same applies as in A) for the to be forwarded packets. Only the
ethernet header is added. However after (queueing for) forwarding the
packet in batadv_recv_bcast_packet()->batadv_forw_bcast_packet(), a
packet is additionally decapsulated and is sent up the stack through
batadv_recv_bcast_packet()->batadv_interface_rx().

Protocols higher up the stack are already required to check if the
packet is shared and create a copy for further modifications. When the
next (protocol) layer works correctly, it cannot happen that it tries to
operate on the data behind the skb clone which is still queued up for
forwarding.
Co-authored-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

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

Broadcast packets send via batadv_send_outstanding_bcast_packet() were
originally copied in batadv_forw_bcast_packet_to_list() before being
queued. And after that only the ethernet header will be pushed through
batadv_send_broadcast_skb()->batadv_send_skb_packet() which works safely
on skb clones as it uses batadv_skb_head_push()->skb_cow_head().
Signed-off-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

Currently we schedule a broadcast packet like:

3x: [ [(re-)queue] --> for(hard-if): maybe-transmit ]

The intention of queueing a broadcast packet multiple times is to
increase robustness for wireless interfaces. However on interfaces
which we only broadcast on once the queueing induces an unnecessary
penalty. This patch restructures the queueing to be performed on a per
interface basis:

for(hard-if):
- transmit
- if wireless: [queue] --> transmit --> [requeue] --> transmit

Next to the performance benefits on non-wireless interfaces this
should also make it easier to apply alternative strategies for
transmissions on wireless interfaces in the future (for instance sending
via unicast transmissions on wireless interfaces, without queueing in
batman-adv, if appropriate).
Signed-off-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

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: NSven Eckelmann <sven@narfation.org>
Acked-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

checkpatch found various instances of "Possible repeated word" in various
comments.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

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

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

All files got a SPDX-License-Identifier with commit 7db7d9f3
("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: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

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

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

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

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

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

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

checkpatch introduced with commit 63b7c73e ("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: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

Trivial fix to spelling mistakes in batadv_dbg debug messages and
also in a comment and ensure comment line is not wider than 80
characters

"ourselve" -> "ourselves"
"surpressed" -> "suppressed"
"troughput" -> "throughput"
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

The function names in batman-adv changed slightly in the past. But some of
the debug messages were not updated correctly and therefore some messages
were incorrect. To avoid this in the future, these kind of messages should
use __func__ to automatically print the correct function name.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

This patch refactors the num_packets counter of a forw_packet in the
following three ways:

1) Removed dual-use of forw_packet::num_packets:
   -> now for aggregation purposes only
2) Using forw_packet::skb::cb::num_bcasts instead:
   -> for easier access in aggregation code later
3) make access to num_bcasts private to batadv_forw_packet_*()
Signed-off-by: NLinus Lüssing <linus.luessing@c0d3.blue>
[sven@narfation.org: Change num_bcasts to unsigned]
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

An skb is assigned to a forw_packet only once, shortly after the
forw_packet allocation.

With this patch the assignment is moved into the this allocation
function.
Signed-off-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

The net_xmit_eval has side effects because it is not making sure that e
isn't evaluated twice.

    #define net_xmit_eval(e)        ((e) == NET_XMIT_CN ? 0 : (e))

The code requested by David Miller [1]

    return net_xmit_eval(dev_queue_xmit(skb));

will get transformed into

    return ((dev_queue_xmit(skb)) == NET_XMIT_CN ? 0 : (dev_queue_xmit(skb)))

dev_queue_xmit will therefore be tried again (with an already consumed skb)
whenever the return code is not NET_XMIT_CN.

[1] https://lkml.kernel.org/r/20170125.225624.965229145391320056.davem@davemloft.net

Fixes: c3370518 ("batman-adv: Treat NET_XMIT_CN as transmit successfully")
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

The tc could return NET_XMIT_CN as one congestion notification, but
it does not mean the packet is lost. Other modules like ipvlan,
macvlan, and others treat NET_XMIT_CN as success too.

So batman-adv should handle NET_XMIT_CN also as NET_XMIT_SUCCESS.
Signed-off-by: NGao Feng <gfree.wind@gmail.com>
[sven@narfation.org: Moved NET_XMIT_CN handling to batadv_send_skb_packet]
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

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

In rare cases during shutdown the following general protection fault can
happen:

  general protection fault: 0000 [#1] SMP
  Modules linked in: batman_adv(O-) [...]
  CPU: 3 PID: 1714 Comm: rmmod Tainted: G           O    4.6.0-rc6+ #1
  [...]
  Call Trace:
   [<ffffffffa0363294>] batadv_hardif_disable_interface+0x29a/0x3a6 [batman_adv]
   [<ffffffffa0373db4>] batadv_softif_destroy_netlink+0x4b/0xa4 [batman_adv]
   [<ffffffff813b52f3>] __rtnl_link_unregister+0x48/0x92
   [<ffffffff813b9240>] rtnl_link_unregister+0xc1/0xdb
   [<ffffffff8108547c>] ? bit_waitqueue+0x87/0x87
   [<ffffffffa03850d2>] batadv_exit+0x1a/0xf48 [batman_adv]
   [<ffffffff810c26f9>] SyS_delete_module+0x136/0x1b0
   [<ffffffff8144dc65>] entry_SYSCALL_64_fastpath+0x18/0xa8
   [<ffffffff8108aaca>] ? trace_hardirqs_off_caller+0x37/0xa6
  Code: 89 f7 e8 21 bd 0d e1 4d 85 e4 75 0e 31 f6 48 c7 c7 50 d7 3b a0 e8 50 16 f2 e0 49 8b 9c 24 28 01 00 00 48 85 db 0f 84 b2 00 00 00 <48> 8b 03 4d 85 ed 48 89 45 c8 74 09 4c 39 ab f8 00 00 00 75 1c
  RIP  [<ffffffffa0371852>] batadv_purge_outstanding_packets+0x1c8/0x291 [batman_adv]
   RSP <ffff88001da5fd78>
  ---[ end trace 803b9bdc6a4a952b ]---
  Kernel panic - not syncing: Fatal exception in interrupt
  Kernel Offset: disabled
  ---[ end Kernel panic - not syncing: Fatal exception in interrupt

It does not happen often, but may potentially happen when frequently
shutting down and reinitializing an interface. With some carefully
placed msleep()s/mdelay()s it can be reproduced easily.

The issue is, that on interface removal, any still running worker thread
of a forwarding packet will race with the interface purging routine to
free a forwarding packet. Temporarily giving up a spin-lock to be able
to sleep in the purging routine is not safe.

Furthermore, there is a potential general protection fault not just for
the purging side shown above, but also on the worker side: Temporarily
removing a forw_packet from the according forw_{bcast,bat}_list will make
it impossible for the purging routine to catch and cancel it.

 # How this patch tries to fix it:

With this patch we split the queue purging into three steps: Step 1),
removing forward packets from the queue of an interface and by that
claim it as our responsibility to free.

Step 2), we are either lucky to cancel a pending worker before it starts
to run. Or if it is already running, we wait and let it do its thing,
except two things:

Through the claiming in step 1) we prevent workers from a) re-arming
themselves. And b) prevent workers from freeing packets which we still
hold in the interface purging routine.

Finally, step 3, we are sure that no forwarding packets are pending or
even running anymore on the interface to remove. We can then safely free
the claimed forwarding packets.
Signed-off-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

No caller of batadv_send_skb_to_orig is expecting the results to be -1
(-EPERM) anymore when the skbuff was not consumed. They will instead expect
that the skbuff is always consumed. Having such return code filter is
therefore not needed anymore.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

Sending functions in Linux consume the supplied skbuff. Doing the same in
batadv_send_skb_to_orig avoids the hack of returning -1 (-EPERM) to signal
the caller that he is responsible for cleaning up the skb.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

kfree_skb assumes that an skb is dropped after an failure and notes that.
consume_skb should be used in non-failure situations. Such information is
important for dropmonitor netlink which tells how many packets were dropped
and where this drop happened.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

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: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

During broadcast queueing, the skb_reset_mac_header() sets the skb
to a place invalid for a MAC header, pointing right into the
batman-adv broadcast packet. Luckily, no one seems to actually use
eth_hdr(skb) afterwards until batadv_send_skb_packet() resets the
header to a valid position again.

Therefore removing this unnecessary, weird skb_reset_mac_header()
call.
Signed-off-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

Some variables are overwritten immediatelly in a functions. These don't
have to be initialized to a specific value on the stack because the value
will be overwritten before they will be used anywhere.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

The function batadv_send_skb_unicast is not acquiring a reference for an
orig_node nor removing it from any datastructure. It still reduces the
reference counter for an object which is still in the hands of the caller.

This is confusing and can lead in the future to problems in the reference
handling of the caller function.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Acked-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

This patch abstracts the forward packet creation into the new function
batadv_forw_packet_alloc().

The queue counting and interface reference counters are now handled
internally within batadv_forw_packet_alloc() and its
batadv_forw_packet_free() counterpart. This should reduce the risk of
having reference/queue counting bugs again and should increase
code readibility.
Signed-off-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

Speedy join only works when the received packet is either broadcast or an
4addr unicast packet. Thus packets converted from broadcast to unicast via
the gateway handling code have to be converted to 4addr packets to allow
the receiving gateway server to add the sender address as temporary entry
to the translation table.

Not doing it will make the batman-adv gateway server drop the DHCP response
in many situations because it doesn't yet have the TT entry for the
destination of the DHCP response.

Fixes: 37135173 ("batman-adv: change interface_rx to get orig node")
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Acked-by: NAntonio Quartulli <a@unstable.cc>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

Return the proper netdev TX status along the TX path so that the tp_meter
can understand when the queue is full and should stop sending packets.
Signed-off-by: NAntonio Quartulli <antonio.quartulli@open-mesh.com>
Signed-off-by: NSven Eckelmann <sven.eckelmann@open-mesh.com>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

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: NMarkus Pargmann <mpa@pengutronix.de>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

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 1e2c2a4f ("batman-adv: Add
required includes to all files") makes includes better manageable.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

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: NAntonio Quartulli <a@unstable.cc>
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>