[ Upstream commit 099e6cc1582dc2903fecb898bbeae8f7cf4262c7 ]

Currently incoming ARP Replies, for example via a DHT-PUT message, do
not update the timeout for an already existing DAT entry. These ARP
Replies are dropped instead.

This however defeats the purpose of the DHCPACK snooping, for instance.
Right now, a DAT entry in the DHT will be purged every five minutes,
likely leading to a mesh-wide ARP Request broadcast after this timeout.
Which then recreates the entry. The idea of the DHCPACK snooping is to
be able to update an entry before a timeout happens, to avoid ARP Request
flooding.

This patch fixes this issue by updating a DAT entry on incoming
ARP Replies even if a matching DAT entry already exists. While still
filtering the ARP Reply towards the soft-interface, to avoid duplicate
messages on the client device side.
Signed-off-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Acked-by: NAntonio Quartulli <a@unstable.cc>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: NSasha Levin <sashal@kernel.org>

commit a3c7cd0cdf1107f891aff847ad481e34df727055 upstream.

Syzbot has reported some issues with the locking assumptions made for
the multicast tt/tvlv worker: It was able to trigger the WARN_ON() in
batadv_mcast_mla_tt_retract() and batadv_mcast_mla_tt_add().
While hard/not reproduceable for us so far it seems that the
delayed_work_pending() we use might not be quite safe from reordering.

Therefore this patch adds an explicit, new spinlock to protect the
update of the mla_list and flags in bat_priv and then removes the
WARN_ON(delayed_work_pending()).

Reported-by: syzbot+83f2d54ec6b7e417e13f@syzkaller.appspotmail.com
Reported-by: syzbot+050927a651272b145a5d@syzkaller.appspotmail.com
Reported-by: syzbot+979ffc89b87309b1b94b@syzkaller.appspotmail.com
Reported-by: syzbot+f9f3f388440283da2965@syzkaller.appspotmail.com
Fixes: cbebd363 ("batman-adv: Use own timer for multicast TT and TVLV updates")
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>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit ca8c3b922e7032aff6cc3fd05548f4df1f3df90e ]

When CONFIG_CFG80211 isn't enabled the compiler correcly warns about
'sinfo.pertid' may be unused. It can also happen for other error
conditions that it not warn about.

net/batman-adv/bat_v_elp.c: In function ‘batadv_v_elp_get_throughput.isra.0’:
include/net/cfg80211.h:6370:13: warning: ‘sinfo.pertid’ may be used
 uninitialized in this function [-Wmaybe-uninitialized]
  kfree(sinfo->pertid);
        ~~~~~^~~~~~~~

Rework so that we only release '&sinfo' if cfg80211_get_station returns
zero.

Fixes: 7d652669b61d ("batman-adv: release station info tidstats")
Signed-off-by: NAnders Roxell <anders.roxell@linaro.org>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit f131a56880d10932931e74773fb8702894a94a75 ]

The batadv_hash_remove is a function which searches the hashtable for an
entry using a needle, a hashtable bucket selection function and a compare
function. It will lock the bucket list and delete an entry when the compare
function matches it with the needle. It returns the pointer to the
hlist_node which matches or NULL when no entry matches the needle.

The batadv_tt_global_free is not itself protected in anyway to avoid that
any other function is modifying the hashtable between the search for the
entry and the call to batadv_hash_remove. It can therefore happen that the
entry either doesn't exist anymore or an entry was deleted which is not the
same object as the needle. In such an situation, the reference counter (for
the reference stored in the hashtable) must not be reduced for the needle.
Instead the reference counter of the actually removed entry has to be
reduced.

Otherwise the reference counter will underflow and the object might be
freed before all its references were dropped. The kref helpers reported
this problem as:

  refcount_t: underflow; use-after-free.

Fixes: 7683fdc1 ("batman-adv: protect the local and the global trans-tables with rcu")
Reported-by: NMartin Weinelt <martin@linuxlounge.net>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Acked-by: NAntonio Quartulli <a@unstable.cc>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 3d65b9accab4a7ed5038f6df403fbd5e298398c7 ]

The batadv_hash_remove is a function which searches the hashtable for an
entry using a needle, a hashtable bucket selection function and a compare
function. It will lock the bucket list and delete an entry when the compare
function matches it with the needle. It returns the pointer to the
hlist_node which matches or NULL when no entry matches the needle.

The batadv_tt_local_remove is not itself protected in anyway to avoid that
any other function is modifying the hashtable between the search for the
entry and the call to batadv_hash_remove. It can therefore happen that the
entry either doesn't exist anymore or an entry was deleted which is not the
same object as the needle. In such an situation, the reference counter (for
the reference stored in the hashtable) must not be reduced for the needle.
Instead the reference counter of the actually removed entry has to be
reduced.

Otherwise the reference counter will underflow and the object might be
freed before all its references were dropped. The kref helpers reported
this problem as:

  refcount_t: underflow; use-after-free.

Fixes: ef72706a ("batman-adv: protect tt_local_entry from concurrent delete events")
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 4ba104f468bbfc27362c393815d03aa18fb7a20f ]

The batadv_hash_remove is a function which searches the hashtable for an
entry using a needle, a hashtable bucket selection function and a compare
function. It will lock the bucket list and delete an entry when the compare
function matches it with the needle. It returns the pointer to the
hlist_node which matches or NULL when no entry matches the needle.

The batadv_bla_del_claim is not itself protected in anyway to avoid that
any other function is modifying the hashtable between the search for the
entry and the call to batadv_hash_remove. It can therefore happen that the
entry either doesn't exist anymore or an entry was deleted which is not the
same object as the needle. In such an situation, the reference counter (for
the reference stored in the hashtable) must not be reduced for the needle.
Instead the reference counter of the actually removed entry has to be
reduced.

Otherwise the reference counter will underflow and the object might be
freed before all its references were dropped. The kref helpers reported
this problem as:

  refcount_t: underflow; use-after-free.

Fixes: 23721387 ("batman-adv: add basic bridge loop avoidance code")
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 7d652669b61d702c6e62a39579d17f6881670ab6 ]

With the addition of TXQ stats in the per-tid statistics the struct
station_info grew significantly. This resulted in stack size warnings
due to the structure itself being above the limit for the warnings.

To work around this, the TID array was allocated dynamically. Also a
function to free this content was introduced with commit 7ea3e110
("cfg80211: release station info tidstats where needed") but the necessary
changes were not provided for batman-adv's B.A.T.M.A.N. V implementation.
Signed-off-by: NFelix Fietkau <nbd@nbd.name>
Fixes: 8689c051 ("cfg80211: dynamically allocate per-tid stats for station info")
[sven@narfation.org: add commit message]
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 4ffcbfac60642f63ae3d80891f573ba7e94a265c ]

KMSAN reported batadv_interface_tx() was possibly using a
garbage value [1]

batadv_get_vid() does have a pskb_may_pull() call
but batadv_interface_tx() does not actually make sure
this did not fail.

[1]
BUG: KMSAN: uninit-value in batadv_interface_tx+0x908/0x1e40 net/batman-adv/soft-interface.c:231
CPU: 0 PID: 10006 Comm: syz-executor469 Not tainted 4.20.0-rc7+ #5
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x173/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x12e/0x2a0 mm/kmsan/kmsan.c:613
 __msan_warning+0x82/0xf0 mm/kmsan/kmsan_instr.c:313
 batadv_interface_tx+0x908/0x1e40 net/batman-adv/soft-interface.c:231
 __netdev_start_xmit include/linux/netdevice.h:4356 [inline]
 netdev_start_xmit include/linux/netdevice.h:4365 [inline]
 xmit_one net/core/dev.c:3257 [inline]
 dev_hard_start_xmit+0x607/0xc40 net/core/dev.c:3273
 __dev_queue_xmit+0x2e42/0x3bc0 net/core/dev.c:3843
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3876
 packet_snd net/packet/af_packet.c:2928 [inline]
 packet_sendmsg+0x8306/0x8f30 net/packet/af_packet.c:2953
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 __sys_sendto+0x8c4/0xac0 net/socket.c:1788
 __do_sys_sendto net/socket.c:1800 [inline]
 __se_sys_sendto+0x107/0x130 net/socket.c:1796
 __x64_sys_sendto+0x6e/0x90 net/socket.c:1796
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x441889
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 bb 10 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffdda6fd468 EFLAGS: 00000216 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000441889
RDX: 000000000000000e RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000216 R12: 00007ffdda6fd4c0
R13: 00007ffdda6fd4b0 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:204 [inline]
 kmsan_internal_poison_shadow+0x92/0x150 mm/kmsan/kmsan.c:158
 kmsan_kmalloc+0xa6/0x130 mm/kmsan/kmsan_hooks.c:176
 kmsan_slab_alloc+0xe/0x10 mm/kmsan/kmsan_hooks.c:185
 slab_post_alloc_hook mm/slab.h:446 [inline]
 slab_alloc_node mm/slub.c:2759 [inline]
 __kmalloc_node_track_caller+0xe18/0x1030 mm/slub.c:4383
 __kmalloc_reserve net/core/skbuff.c:137 [inline]
 __alloc_skb+0x309/0xa20 net/core/skbuff.c:205
 alloc_skb include/linux/skbuff.h:998 [inline]
 alloc_skb_with_frags+0x1c7/0xac0 net/core/skbuff.c:5220
 sock_alloc_send_pskb+0xafd/0x10e0 net/core/sock.c:2083
 packet_alloc_skb net/packet/af_packet.c:2781 [inline]
 packet_snd net/packet/af_packet.c:2872 [inline]
 packet_sendmsg+0x661a/0x8f30 net/packet/af_packet.c:2953
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 __sys_sendto+0x8c4/0xac0 net/socket.c:1788
 __do_sys_sendto net/socket.c:1800 [inline]
 __se_sys_sendto+0x107/0x130 net/socket.c:1796
 __x64_sys_sendto+0x6e/0x90 net/socket.c:1796
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Fixes: c6c8fea2 ("net: Add batman-adv meshing protocol")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Cc:	Marek Lindner <mareklindner@neomailbox.ch>
Cc:	Simon Wunderlich <sw@simonwunderlich.de>
Cc:	Antonio Quartulli <a@unstable.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 9114daa825fc3f335f9bea3313ce667090187280 upstream.

The caller of ndo_start_xmit may not already have called
skb_reset_mac_header. The returned value of skb_mac_header/eth_hdr
therefore can be in the wrong position and even outside the current skbuff.
This for example happens when the user binds to the device using a
PF_PACKET-SOCK_RAW with enabled qdisc-bypass:

  int opt = 4;
  setsockopt(sock, SOL_PACKET, PACKET_QDISC_BYPASS, &opt, sizeof(opt));

Since eth_hdr is used all over the codebase, the batadv_interface_tx
function must always take care of resetting it.

Fixes: c6c8fea2 ("net: Add batman-adv meshing protocol")
Reported-by: syzbot+9d7405c7faa390e60b4e@syzkaller.appspotmail.com
Reported-by: syzbot+7d20bc3f1ddddc0f9079@syzkaller.appspotmail.com
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 955d3411a17f590364238bd0d3329b61f20c1cd2 upstream.

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: b7eddd0b ("batman-adv: prevent using any virtual device created on batman-adv as hard-interface")
Reported-by: syzbot+c764de0fcfadca9a8595@syzkaller.appspotmail.com
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit d7d8bbb4 ]

The complete size ("total_size") of the fragmented packet is stored in the
fragment header and in the size of the fragment chain. When the fragments
are ready for merge, the skbuff's tail of the first fragment is expanded to
have enough room after the data pointer for at least total_size. This means
that it gets expanded by total_size - first_skb->len.

But this is ignoring the fact that after expanding the buffer, the fragment
header is pulled by from this buffer. Assuming that the tailroom of the
buffer was already 0, the buffer after the data pointer of the skbuff is
now only total_size - len(fragment_header) large. When the merge function
is then processing the remaining fragments, the code to copy the data over
to the merged skbuff will cause an skb_over_panic when it tries to actually
put enough data to fill the total_size bytes of the packet.

The size of the skb_pull must therefore also be taken into account when the
buffer's tailroom is expanded.

Fixes: 610bfc6b ("batman-adv: Receive fragmented packets and merge")
Reported-by: NMartin Weinelt <martin@darmstadt.freifunk.net>
Co-authored-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit f4156f96 ]

The announcement messages of batman-adv COMPAT_VERSION 15 have the
possibility to announce additional information via a dynamic TVLV part.
This part is optional for the ELP packets and currently not parsed by the
Linux implementation. Still out-of-tree versions are using it to transport
things like neighbor hashes to optimize the rebroadcast behavior.

Since the ELP broadcast packets are smaller than the minimal ethernet
packet, it often has to be padded. This is often done (as specified in
RFC894) with octets of zero and thus work perfectly fine with the TVLV
part (making it a zero length and thus empty). But not all ethernet
compatible hardware seems to follow this advice. To avoid ambiguous
situations when parsing the TVLV header, just force the 4 bytes (TVLV
length + padding) after the required ELP header to zero.

Fixes: d6f94d91 ("batman-adv: ELP - adding basic infrastructure")
Reported-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: NSasha Levin <sashal@kernel.org>

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

The hardif_neigh refcounter is to be decreased by the queued work and
currently is never decreased if the queue_work() call fails.
Fix by checking the queue_work() return value and decrease refcount
if necessary.
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

The backbone_gw refcounter is to be decreased by the queued work and
currently is never decreased if the queue_work() call fails.
Fix by checking the queue_work() return value and decrease refcount
if necessary.
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

The function batadv_tvlv_handler_register is responsible for adding new
tvlv_handler to the handler_list. It first checks whether the entry
already is in the list or not. If it is, then the creation of a new entry
is aborted.

But the lock for the list is only held when the list is really modified.
This could lead to duplicated entries because another context could create
an entry with the same key between the check and the list manipulation.

The check and the manipulation of the list must therefore be in the same
locked code section.

Fixes: ef261577 ("batman-adv: tvlv - basic infrastructure")
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

The function batadv_tt_global_orig_entry_add is responsible for adding new
tt_orig_list_entry to the orig_list. It first checks whether the entry
already is in the list or not. If it is, then the creation of a new entry
is aborted.

But the lock for the list is only held when the list is really modified.
This could lead to duplicated entries because another context could create
an entry with the same key between the check and the list manipulation.

The check and the manipulation of the list must therefore be in the same
locked code section.

Fixes: d657e621 ("batman-adv: add reference counting for type batadv_tt_orig_list_entry")
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

The function batadv_softif_vlan_get is responsible for adding new
softif_vlan to the softif_vlan_list. It first checks whether the entry
already is in the list or not. If it is, then the creation of a new entry
is aborted.

But the lock for the list is only held when the list is really modified.
This could lead to duplicated entries because another context could create
an entry with the same key between the check and the list manipulation.

The check and the manipulation of the list must therefore be in the same
locked code section.

Fixes: 5d2c05b2 ("batman-adv: add per VLAN interface attribute framework")
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

The function batadv_nc_get_nc_node is responsible for adding new nc_nodes
to the in_coding_list and out_coding_list. It first checks whether the
entry already is in the list or not. If it is, then the creation of a new
entry is aborted.

But the lock for the list is only held when the list is really modified.
This could lead to duplicated entries because another context could create
an entry with the same key between the check and the list manipulation.

The check and the manipulation of the list must therefore be in the same
locked code section.

Fixes: d56b1705 ("batman-adv: network coding - detect coding nodes and remove these after timeout")
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Acked-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

The function batadv_gw_node_add is responsible for adding new gw_node to
the gateway_list. It is expecting that the caller already checked that
there is not already an entry with the same key or not.

But the lock for the list is only held when the list is really modified.
This could lead to duplicated entries because another context could create
an entry with the same key between the check and the list manipulation.

The check and the manipulation of the list must therefore be in the same
locked code section.

Fixes: c6c8fea2 ("net: Add batman-adv meshing protocol")
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Acked-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

The per hardif sysfs file "batman_adv/elp_interval" is using the generic
functions to store/show uint values. The helper __batadv_store_uint_attr
requires the softif net_device as parameter to print the resulting change
as info text when the users writes to this file. It uses the helper
function batadv_info to add it at the same time to the kernel ring buffer
and to the batman-adv debug log (when CONFIG_BATMAN_ADV_DEBUG is enabled).

The function batadv_info requires as first parameter the batman-adv softif
net_device. This parameter is then used to find the private buffer which
contains the debug log for this batman-adv interface. But
batadv_store_throughput_override used as first argument the slave
net_device. This slave device doesn't have the batadv_priv private data
which is access by batadv_info.

Writing to this file with CONFIG_BATMAN_ADV_DEBUG enabled can either lead
to a segfault or to memory corruption.

Fixes: 0744ff8f ("batman-adv: Add hard_iface specific sysfs wrapper macros for UINT")
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Acked-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

The per hardif sysfs file "batman_adv/throughput_override" prints the
resulting change as info text when the users writes to this file. It uses
the helper function batadv_info to add it at the same time to the kernel
ring buffer and to the batman-adv debug log (when CONFIG_BATMAN_ADV_DEBUG
is enabled).

The function batadv_info requires as first parameter the batman-adv softif
net_device. This parameter is then used to find the private buffer which
contains the debug log for this batman-adv interface. But
batadv_store_throughput_override used as first argument the slave
net_device. This slave device doesn't have the batadv_priv private data
which is access by batadv_info.

Writing to this file with CONFIG_BATMAN_ADV_DEBUG enabled can either lead
to a segfault or to memory corruption.

Fixes: 0b5ecc68 ("batman-adv: add throughput override attribute to hard_ifaces")
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Acked-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

The probe ELPs for WiFi interfaces are expanded to contain at least
BATADV_ELP_MIN_PROBE_SIZE bytes. This is usually a lot more than the
number of bytes which the template ELP packet requires.

These extra padding bytes were not initialized and thus could contain data
which were previously stored at the same location. It is therefore required
to set it to some predefined or random values to avoid leaking private
information from the system transmitting these kind of packets.

Fixes: e4623c913508 ("batman-adv: Avoid probe ELP information leak")
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Acked-by: NAntonio Quartulli <a@unstable.cc>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

The #define for batadv_dat_addr_t is doing nothing else than giving u16 a
new typename. But C already has the special keyword "typedef" which is also
better supported by kernel-doc.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Acked-by: NAntonio Quartulli <a@unstable.cc>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

The single line function batadv_purge_orig_ref has no function beside
providing the name used by other source files. This can also be done
simpler by just renaming _batadv_purge_orig to batadv_purge_orig_ref.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

All other include guards in batman-adv use the style:

* _NET_BATMAN_ADV_$(FILENAME)_
* uppercase only
* "." & "-" replaced with "_"

Use this also in the B.A.T.M.A.N. IV/V OGM implementation headers.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

commit a2d4df9b673c ("spelling.txt: add more spellings to spelling.txt")
introduced the spellcheck of "cache" for checkpatch.pl.
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

The "default n" is the default value for any bool or tristate Kconfig
setting. It is therefore not necessary to add it to a config entry.
Reported-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

DAT (Distributed ARP Table) has been enabled by default
in the out-of-tree batman-adv kernel module for several
years already.
It can now be enabled in the kernel too.
Signed-off-by: NAntonio Quartulli <a@unstable.cc>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

The Kconfig option BATMAN_ADV_BATMAN_V is now enabled by default when the
BATMAN_ADV is enabled. A feature which is enabled by default for a module
should not be considered experimental.
Reported-by: NJoe Perches <joe@perches.com>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

When a (broken) node wrongly sends multicast TT entries with a ROAM
flag then this causes any receiving node to drop all entries for the
same multicast MAC address announced by other nodes, leading to
packet loss.

Fix this DoS vector by only storing TT sync flags. For multicast TT
non-sync'ing flag bits like ROAM are unused so far anyway.

Fixes: 1d8ab8d3 ("batman-adv: Modified forwarding behaviour for multicast packets")
Reported-by: NLeonardo Mörlein <me@irrelefant.net>
Signed-off-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

Since commit 54e22f26 ("batman-adv: fix TT sync flag inconsistencies")
TT sync flags and TT non-sync'd flags are supposed to be stored
separately.

The previous patch missed to apply this separation on a TT entry with
only a single TT orig entry.

This is a minor fix because with only a single TT orig entry the DDoS
issue the former patch solves does not apply.

Fixes: 54e22f26 ("batman-adv: fix TT sync flag inconsistencies")
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>

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: c6c8fea2 ("net: Add batman-adv meshing protocol")
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

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: 5bc7c1eb ("batman-adv: add debugfs structure for information per interface")
Reported-by: NJohn Soros <sorosj@gmail.com>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

A reference for the best gateway is taken when the list of gateways in the
mesh is sent via netlink. This is necessary to check whether the currently
dumped entry is the currently selected gateway or not. This information is
then transferred as flag BATADV_ATTR_FLAG_BEST.

After the comparison of the current entry is done,
batadv_v_gw_dump_entry() has to decrease the reference counter again.
Otherwise the reference will be held and thus prevents a proper shutdown of
the batman-adv interfaces (and some of the interfaces enslaved in it).

Fixes: b71bb6f9 ("batman-adv: add B.A.T.M.A.N. V bat_gw_dump implementations")
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Acked-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

A reference for the best gateway is taken when the list of gateways in the
mesh is sent via netlink. This is necessary to check whether the currently
dumped entry is the currently selected gateway or not. This information is
then transferred as flag BATADV_ATTR_FLAG_BEST.

After the comparison of the current entry is done,
batadv_iv_gw_dump_entry() has to decrease the reference counter again.
Otherwise the reference will be held and thus prevents a proper shutdown of
the batman-adv interfaces (and some of the interfaces enslaved in it).

Fixes: efb766af ("batman-adv: add B.A.T.M.A.N. IV bat_gw_dump implementations")
Reported-by: NAndreas Ziegler <dev@andreas-ziegler.de>
Tested-by: NAndreas Ziegler <dev@andreas-ziegler.de>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Acked-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

random_ether_addr is a #define for eth_random_addr which is
generally preferred in kernel code by ~3:1

Convert the uses of random_ether_addr to enable removing the #define

Miscellanea:

o Convert &vfmac[0] to equivalent vfmac and avoid unnecessary line wrap
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

Virtual interface drivers such as tun / tap interfaces, VLAN, etc tend
to initialize the interface throughput with some value for the sake of
having a throughput number to export via ethtool. This exported
throughput leaves batman-adv to conclude the interface throughput is
genuine (reflecting reality), thus no measurements are necessary.

Based on the observation that those interface types also tend to set
the link auto-negotiation to 'off', batman-adv shall check this
setting to differentiate between genuine link throughput information
and placeholders installed by virtual interfaces.

The "default throughput" setting exported via sysfs still allows to
configure the batman-adv throughput for the interface, thus disabling
the measurements.
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
Acked-by: NAntonio Quartulli <a@unstable.cc>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>

A translation table TVLV changset sent with an OGM consists
of a number of headers (one per VLAN) plus the changeset
itself (addition and/or deletion of entries).

The per-VLAN headers are used by OGM recipients for consistency
checks. Said consistency check might determine that a full
translation table request is needed to restore consistency. If
the TT sender adds per-VLAN headers of empty VLANs into the OGM,
recipients are led to believe to have reached an inconsistent
state and thus request a full table update. The full table does
not contain empty VLANs (due to missing entries) the cycle
restarts when the next OGM is issued.

Consequently, when the translation table TVLV headers are
composed, empty VLANs are to be excluded.

Fixes: 21a57f6e7a3b ("batman-adv: make the TT CRC logic VLAN specific")
Signed-off-by: NMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wunderlich <sw@simonwunderlich.de>