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<title>lwn.git/net/batman-adv/soft-interface.c, branch docs-5.10-3</title>
<subtitle>Linux kernel documentation tree maintained by Jonathan Corbet</subtitle>
<id>http://mirrors.hust.edu.cn/git/lwn.git/atom?h=docs-5.10-3</id>
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<updated>2020-09-22T23:45:34+00:00</updated>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2020-09-22T23:45:34+00:00</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2020-09-22T23:45:34+00:00</published>
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<id>urn:sha1:3ab0a7a0c349a1d7beb2bb371a62669d1528269d</id>
<content type='text'>
Two minor conflicts:

1) net/ipv4/route.c, adding a new local variable while
   moving another local variable and removing it's
   initial assignment.

2) drivers/net/dsa/microchip/ksz9477.c, overlapping changes.
   One pretty prints the port mode differently, whilst another
   changes the driver to try and obtain the port mode from
   the port node rather than the switch node.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>batman-adv: mcast: fix duplicate mcast packets in BLA backbone from mesh</title>
<updated>2020-09-15T08:05:24+00:00</updated>
<author>
<name>Linus Lüssing</name>
<email>linus.luessing@c0d3.blue</email>
</author>
<published>2020-09-15T07:54:09+00:00</published>
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<id>urn:sha1:74c09b7275126da1b642b90c9cdc3ae8b729ad4b</id>
<content type='text'>
Scenario:
* Multicast frame send from mesh to a BLA backbone (multiple nodes
  with their bat0 bridged together, with BLA enabled)

Issue:
* BLA backbone nodes receive the frame multiple times on bat0,
  once from mesh-&gt;bat0 and once from each backbone_gw from LAN

For unicast, a node will send only to the best backbone gateway
according to the TQ. However for multicast we currently cannot determine
if multiple destination nodes share the same backbone if they don't share
the same backbone with us. So we need to keep sending the unicasts to
all backbone gateways and let the backbone gateways decide which one
will forward the frame. We can use the CLAIM mechanism to make this
decision.

One catch: The batman-adv gateway feature for DHCP packets potentially
sends multicast packets in the same batman-adv unicast header as the
multicast optimizations code. And we are not allowed to drop those even
if we did not claim the source address of the sender, as for such
packets there is only this one multicast-in-unicast packet.

How can we distinguish the two cases?

The gateway feature uses a batman-adv unicast 4 address header. While
the multicast-to-unicasts feature uses a simple, 3 address batman-adv
unicast header. So let's use this to distinguish.

Fixes: fe2da6ff27c7 ("batman-adv: check incoming packet type for bla")
Signed-off-by: Linus Lüssing &lt;linus.luessing@c0d3.blue&gt;
Signed-off-by: Sven Eckelmann &lt;sven@narfation.org&gt;
Signed-off-by: Simon Wunderlich &lt;sw@simonwunderlich.de&gt;
</content>
</entry>
<entry>
<title>batman-adv: mcast: fix duplicate mcast packets in BLA backbone from LAN</title>
<updated>2020-09-15T08:05:24+00:00</updated>
<author>
<name>Linus Lüssing</name>
<email>linus.luessing@c0d3.blue</email>
</author>
<published>2020-09-15T07:54:08+00:00</published>
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<id>urn:sha1:3236d215ad38a3f5372e65cd1e0a52cf93d3c6a2</id>
<content type='text'>
Scenario:
* Multicast frame send from a BLA backbone (multiple nodes with
  their bat0 bridged together, with BLA enabled)

Issue:
* BLA backbone nodes receive the frame multiple times on bat0

For multicast frames received via batman-adv broadcast packets the
originator of the broadcast packet is checked before decapsulating and
forwarding the frame to bat0 (batadv_bla_is_backbone_gw()-&gt;
batadv_recv_bcast_packet()). If it came from a node which shares the
same BLA backbone with us then it is not forwarded to bat0 to avoid a
loop.

When sending a multicast frame in a non-4-address batman-adv unicast
packet we are currently missing this check - and cannot do so because
the batman-adv unicast packet has no originator address field.

However, we can simply fix this on the sender side by only sending the
multicast frame via unicasts to interested nodes which do not share the
same BLA backbone with us. This also nicely avoids some unnecessary
transmissions on mesh side.

Note that no infinite loop was observed, probably because of dropping
via batadv_interface_tx()-&gt;batadv_bla_tx(). However the duplicates still
utterly confuse switches/bridges, ICMPv6 duplicate address detection and
neighbor discovery and therefore leads to long delays before being able
to establish TCP connections, for instance. And it also leads to the Linux
bridge printing messages like:
"br-lan: received packet on eth1 with own address as source address ..."

Fixes: 2d3f6ccc4ea5 ("batman-adv: Modified forwarding behaviour for multicast packets")
Signed-off-by: Linus Lüssing &lt;linus.luessing@c0d3.blue&gt;
Signed-off-by: Sven Eckelmann &lt;sven@narfation.org&gt;
Signed-off-by: Simon Wunderlich &lt;sw@simonwunderlich.de&gt;
</content>
</entry>
<entry>
<title>batman-adv: Drop repeated words in comments</title>
<updated>2020-08-18T17:39:54+00:00</updated>
<author>
<name>Sven Eckelmann</name>
<email>sven@narfation.org</email>
</author>
<published>2020-07-31T18:33:00+00:00</published>
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<id>urn:sha1:21ba5ab2aa8adecef4addf8f481c33f204da93d2</id>
<content type='text'>
checkpatch found various instances of "Possible repeated word" in various
comments.

Signed-off-by: Sven Eckelmann &lt;sven@narfation.org&gt;
Signed-off-by: Simon Wunderlich &lt;sw@simonwunderlich.de&gt;
</content>
</entry>
<entry>
<title>batman-adv: Fix typos and grammar in documentation</title>
<updated>2020-06-26T08:36:30+00:00</updated>
<author>
<name>Sven Eckelmann</name>
<email>sven@narfation.org</email>
</author>
<published>2020-06-01T18:13:21+00:00</published>
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<id>urn:sha1:bccb48c89fe3c09f1cbb7c8612e31f5daa1d4541</id>
<content type='text'>
Signed-off-by: Sven Eckelmann &lt;sven@narfation.org&gt;
Signed-off-by: Simon Wunderlich &lt;sw@simonwunderlich.de&gt;
</content>
</entry>
<entry>
<title>net: change addr_list_lock back to static key</title>
<updated>2020-06-09T19:59:45+00:00</updated>
<author>
<name>Cong Wang</name>
<email>xiyou.wangcong@gmail.com</email>
</author>
<published>2020-06-08T21:53:01+00:00</published>
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<id>urn:sha1:845e0ebb4408d4473cf60d21224a897037e9a77a</id>
<content type='text'>
The dynamic key update for addr_list_lock still causes troubles,
for example the following race condition still exists:

CPU 0:				CPU 1:
(RCU read lock)			(RTNL lock)
dev_mc_seq_show()		netdev_update_lockdep_key()
				  -&gt; lockdep_unregister_key()
 -&gt; netif_addr_lock_bh()

because lockdep doesn't provide an API to update it atomically.
Therefore, we have to move it back to static keys and use subclass
for nest locking like before.

In commit 1a33e10e4a95 ("net: partially revert dynamic lockdep key
changes"), I already reverted most parts of commit ab92d68fc22f
("net: core: add generic lockdep keys").

This patch reverts the rest and also part of commit f3b0a18bb6cb
("net: remove unnecessary variables and callback"). After this
patch, addr_list_lock changes back to using static keys and
subclasses to satisfy lockdep. Thanks to dev-&gt;lower_level, we do
not have to change back to -&gt;ndo_get_lock_subclass().

And hopefully this reduces some syzbot lockdep noises too.

Reported-by: syzbot+f3a0e80c34b3fc28ac5e@syzkaller.appspotmail.com
Cc: Taehee Yoo &lt;ap420073@gmail.com&gt;
Cc: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Signed-off-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>batman-adv: Revert "Drop lockdep.h include for soft-interface.c"</title>
<updated>2020-05-22T12:19:23+00:00</updated>
<author>
<name>Sven Eckelmann</name>
<email>sven@narfation.org</email>
</author>
<published>2020-05-06T20:13:30+00:00</published>
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<id>urn:sha1:2092c910e2399c9e13b199c07421133681b9eaff</id>
<content type='text'>
The commit 1a33e10e4a95 ("net: partially revert dynamic lockdep key
changes") reverts the commit ab92d68fc22f ("net: core: add generic lockdep
keys"). But it forgot to also revert the commit 5759af0682b3 ("batman-adv:
Drop lockdep.h include for soft-interface.c") which depends on the latter.

Signed-off-by: Sven Eckelmann &lt;sven@narfation.org&gt;
Signed-off-by: Simon Wunderlich &lt;sw@simonwunderlich.de&gt;
</content>
</entry>
<entry>
<title>net: partially revert dynamic lockdep key changes</title>
<updated>2020-05-04T19:05:56+00:00</updated>
<author>
<name>Cong Wang</name>
<email>xiyou.wangcong@gmail.com</email>
</author>
<published>2020-05-03T05:22:19+00:00</published>
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<id>urn:sha1:1a33e10e4a95cb109ff1145098175df3113313ef</id>
<content type='text'>
This patch reverts the folowing commits:

commit 064ff66e2bef84f1153087612032b5b9eab005bd
"bonding: add missing netdev_update_lockdep_key()"

commit 53d374979ef147ab51f5d632dfe20b14aebeccd0
"net: avoid updating qdisc_xmit_lock_key in netdev_update_lockdep_key()"

commit 1f26c0d3d24125992ab0026b0dab16c08df947c7
"net: fix kernel-doc warning in &lt;linux/netdevice.h&gt;"

commit ab92d68fc22f9afab480153bd82a20f6e2533769
"net: core: add generic lockdep keys"

but keeps the addr_list_lock_key because we still lock
addr_list_lock nestedly on stack devices, unlikely xmit_lock
this is safe because we don't take addr_list_lock on any fast
path.

Reported-and-tested-by: syzbot+aaa6fa4949cc5d9b7b25@syzkaller.appspotmail.com
Cc: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Cc: Taehee Yoo &lt;ap420073@gmail.com&gt;
Signed-off-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Acked-by: Taehee Yoo &lt;ap420073@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>batman-adv: Update copyright years for 2020</title>
<updated>2019-12-31T23:00:33+00:00</updated>
<author>
<name>Sven Eckelmann</name>
<email>sven@narfation.org</email>
</author>
<published>2019-12-31T23:00:01+00:00</published>
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<id>urn:sha1:68e039f966cb577c91649a02591646ac3919f8c9</id>
<content type='text'>
Signed-off-by: Sven Eckelmann &lt;sven@narfation.org&gt;
Signed-off-by: Simon Wunderlich &lt;sw@simonwunderlich.de&gt;
</content>
</entry>
<entry>
<title>batman-adv: Drop lockdep.h include for soft-interface.c</title>
<updated>2019-11-03T07:30:58+00:00</updated>
<author>
<name>Sven Eckelmann</name>
<email>sven@narfation.org</email>
</author>
<published>2019-10-30T07:03:49+00:00</published>
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<id>urn:sha1:5759af0682b3395e64cf615e062d6ecad01428dc</id>
<content type='text'>
The commit ab92d68fc22f ("net: core: add generic lockdep keys") removed
all lockdep functionality from soft-interface.c but didn't remove the
include for this functionality.

Signed-off-by: Sven Eckelmann &lt;sven@narfation.org&gt;
Signed-off-by: Simon Wunderlich &lt;sw@simonwunderlich.de&gt;
</content>
</entry>
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