rtnetlink: prepare nla_put_iflink() to run under RCU

We want to be able to run rtnl_fill_ifinfo() under RCU protection
instead of RTNL in the future.

This patch prepares dev_get_iflink() and nla_put_iflink()
to run either with RTNL or RCU held.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: fill in MODULE_DESCRIPTION()s for ieee802154

W=1 builds now warn if module is built without a MODULE_DESCRIPTION().
Add descriptions to ieee802154 modules.

Signed-off-by: Breno Leitao <leitao@debian.org>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: don't include ndisc.h from ipv6.h

Nothing in ipv6.h needs ndisc.h, drop it.

Link: https://lore.kernel.org/r/20220203043457.2222388-1-kuba@kernel.org
Acked-by: Jeremy Kerr <jk@codeconstruct.com.au>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org>
Link: https://lore.kernel.org/r/20220203231240.2297588-1-kuba@kernel.org
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mac802154: use dev_addr_set() - manual

Commit 406f42fa0d3c ("net-next: When a bond have a massive amount
of VLANs...") introduced a rbtree for faster Ethernet address look
up. To maintain netdev->dev_addr in this tree we need to make all
the writes to it got through appropriate helpers.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: partially revert dynamic lockdep key changes

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 <linux/netdevice.h>"

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 <dvyukov@google.com>
Cc: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: core: add generic lockdep keys

Some interface types could be nested.
(VLAN, BONDING, TEAM, MACSEC, MACVLAN, IPVLAN, VIRT_WIFI, VXLAN, etc..)
These interface types should set lockdep class because, without lockdep
class key, lockdep always warn about unexisting circular locking.

In the current code, these interfaces have their own lockdep class keys and
these manage itself. So that there are so many duplicate code around the
/driver/net and /net/.
This patch adds new generic lockdep keys and some helper functions for it.

This patch does below changes.
a) Add lockdep class keys in struct net_device
- qdisc_running, xmit, addr_list, qdisc_busylock
- these keys are used as dynamic lockdep key.
b) When net_device is being allocated, lockdep keys are registered.
- alloc_netdev_mqs()
c) When net_device is being free'd llockdep keys are unregistered.
- free_netdev()
d) Add generic lockdep key helper function
- netdev_register_lockdep_key()
- netdev_unregister_lockdep_key()
- netdev_update_lockdep_key()
e) Remove unnecessary generic lockdep macro and functions
f) Remove unnecessary lockdep code of each interfaces.

After this patch, each interface modules don't need to maintain
their lockdep keys.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ieee802154: 6lowpan: set IFLA_LINK

Otherwise NetworkManager (and iproute alike) is not able to identify the
parent IEEE 802.15.4 interface of a 6LoWPAN link.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Alexander Aring <aring@mojatatu.com>
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>

ieee802154: 6lowpan: fix possible NULL deref in lowpan_device_event()

A tun device type can trivially be set to arbitrary value using
TUNSETLINK ioctl().

Therefore, lowpan_device_event() must really check that ieee802154_ptr
is not NULL.

Fixes: 2c88b5283f60d ("ieee802154: 6lowpan: remove check on null")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Alexander Aring <alex.aring@gmail.com>
Cc: Stefan Schmidt <stefan@osg.samsung.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ieee802154: 6lowpan: set IFF_NO_QUEUE

This patch sets the IFF_NO_QUEUE for IEEE 802.15.4 6lowpan interfaces. As
commit 24dcbf662205 ("6lowpan: Don't set IFF_NO_QUEUE") removes it for
"reasons" from the bluetooth 6lowpan subsystem. In IEEE 802.15.4 the lower
interface deals with one qdisc for the real hardware, 6LoWPAN does the
protocol adaption only and no second queuing on top.

Signed-off-by: Alexander Aring <aring@mojatatu.com>
Signed-off-by: Stefan Schmidt <stefan@osg.samsung.com>

ieee802154: 6lowpan: make header_ops const

Make this const as it is only stored as a reference in a const field of
a net_device structure.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Acked-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net: add netlink_ext_ack argument to rtnl_link_ops.validate

Add support for extended error reporting.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: add netlink_ext_ack argument to rtnl_link_ops.newlink

Add support for extended error reporting.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Fix inconsistent teardown and release of private netdev state.

Network devices can allocate reasources and private memory using
netdev_ops->ndo_init(). However, the release of these resources
can occur in one of two different places.

Either netdev_ops->ndo_uninit() or netdev->destructor().

The decision of which operation frees the resources depends upon
whether it is necessary for all netdev refs to be released before it
is safe to perform the freeing.

netdev_ops->ndo_uninit() presumably can occur right after the
NETDEV_UNREGISTER notifier completes and the unicast and multicast
address lists are flushed.

netdev->destructor(), on the other hand, does not run until the
netdev references all go away.

Further complicating the situation is that netdev->destructor()
almost universally does also a free_netdev().

This creates a problem for the logic in register_netdevice().
Because all callers of register_netdevice() manage the freeing
of the netdev, and invoke free_netdev(dev) if register_netdevice()
fails.

If netdev_ops->ndo_init() succeeds, but something else fails inside
of register_netdevice(), it does call ndo_ops->ndo_uninit(). But
it is not able to invoke netdev->destructor().

This is because netdev->destructor() will do a free_netdev() and
then the caller of register_netdevice() will do the same.

However, this means that the resources that would normally be released
by netdev->destructor() will not be.

Over the years drivers have added local hacks to deal with this, by
invoking their destructor parts by hand when register_netdevice()
fails.

Many drivers do not try to deal with this, and instead we have leaks.

Let's close this hole by formalizing the distinction between what
private things need to be freed up by netdev->destructor() and whether
the driver needs unregister_netdevice() to perform the free_netdev().

netdev->priv_destructor() performs all actions to free up the private
resources that used to be freed by netdev->destructor(), except for
free_netdev().

netdev->needs_free_netdev is a boolean that indicates whether
free_netdev() should be done at the end of unregister_netdevice().

Now, register_netdevice() can sanely release all resources after
ndo_ops->ndo_init() succeeds, by invoking both ndo_ops->ndo_uninit()
and netdev->priv_destructor().

And at the end of unregister_netdevice(), we invoke
netdev->priv_destructor() and optionally call free_netdev().

Signed-off-by: David S. Miller <davem@davemloft.net>

ieee802154: allow netns create of lowpan interface

This patch reverts commit f9d1ce8f81eb ("ieee802154: fix netns settings").
The lowpan interface need to be created inside the net namespace where
the wpan interface is available. The wpan namespace can be changed only
by nl802154 before. Without this patch it's not possible to create a
lowpan interface for a wpan interface which isn't inside init_net
namespace.

Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Alexander Aring <aar@pengutronix.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net: add dev arg to ndo_neigh_construct/destroy

As the following patch will allow upper devices to follow the call down
lower devices, we need to add dev here and not rely on n->dev.

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

6lowpan: add private neighbour data

This patch will introduce a 6lowpan neighbour private data. Like the
interface private data we handle private data for generic 6lowpan and
for link-layer specific 6lowpan.

The current first use case if to save the short address for a 802.15.4
6lowpan neighbour.

Cc: David S. Miller <davem@davemloft.net>
Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Alexander Aring <aar@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: add netdev_lockdep_set_classes() helper

It is time to add netdev_lockdep_set_classes() helper
so that lockdep annotations per device type are easier to manage.

This removes a lot of copies and missing annotations.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net_sched: transform qdisc running bit into a seqcount

Instead of using a single bit (__QDISC___STATE_RUNNING)
in sch->__state, use a seqcount.

This adds lockdep support, but more importantly it will allow us
to sample qdisc/class statistics without having to grab qdisc root lock.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

6lowpan: change naming for lowpan private data

This patch changes the naming for interface private data for lowpan
intefaces. The current private data scheme is:

-------------------------------------------------
| 6LoWPAN Generic | LinkLayer 6LoWPAN |
-------------------------------------------------

the current naming schemes are:

- 6LoWPAN Generic:
- lowpan_priv
- LinkLayer 6LoWPAN:
- BTLE
- lowpan_dev
- 802.15.4:
- lowpan_dev_info

the new naming scheme with this patch will be:

- 6LoWPAN Generic:
- lowpan_dev
- LinkLayer 6LoWPAN:
- BTLE
- lowpan_btle_dev
- 802.15.4:
- lowpan_802154_dev

Signed-off-by: Alexander Aring <aar@pengutronix.de>
Reviewed-by: Stefan Schmidt<stefan@osg.samsung.com>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

ieee802154: 6lowpan: fix return of netdev notifier

This patch fixed the return value of netdev notifier. If the command is
a don't care a NOTIFY_DONE should be returned. If the command matched a
NOTIFY_OK should be returned.

Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Alexander Aring <aar@pengutronix.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

6lowpan: add lowpan dev register helpers

This patch introduces register and unregister functionality for lowpan
interfaces. While register a lowpan interface there are several things
which need to be initialize by the 6lowpan subsystem. Upcoming
functionality need to register/unregister per interface components e.g.
debugfs entry.

Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

6lowpan: move shared settings to lowpan_netdev_setup

This patch moves values for all lowpan interface to the shared
implementation of 6lowpan. This patch also quietly fixes the forgotten
IFF_NO_QUEUE flag for the bluetooth 6LoWPAN interface. An identically
commit is 4afbc0d ("net: 6lowpan: convert to using IFF_NO_QUEUE") which
wasn't changed for bluetooth 6lowpan.

All 6lowpan interfaces should be virtual with IFF_NO_QUEUE, using EUI64
address length, the mtu size is 1280 (IPV6_MIN_MTU) and the netdev type
is ARPHRD_6LOWPAN.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

ieee802154: change needed headroom/tailroom

This patch cleanups needed_headroom, needed_tailroom and hard_header_len
fields for wpan and lowpan interfaces.

For wpan interfaces the worst case mac header len should be part of
needed_headroom, currently this is set as hard_header_len, but
hard_header_len should be set to the minimum header length which xmit
call assumes and this is the minimum frame length of 802.15.4.
The hard_header_len value will check inside send callbacl of AF_PACKET
raw sockets.

For lowpan interfaces, if fragmentation isn't needed the skb will
call dev_hard_header for 802154 layer and queue it afterwards. This
happens without new skb allocation, so we need the same headroom and
tailroom lengths like 802154 inside 802154 6lowpan layer. At least we
assume as minimum header length an ipv6 header size.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

ieee802154: 6lowpan: remove set to zero

Internal mechanism by calling netdev_alloc which use kzalloc already
sets these variables to zero. This patch cleanup the setup of net_device.

Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

ieee802154: 6lowpan: remove check on null

This patch removes one check on null which should be already done by
checking before for ARPHRD_IEEE802154. All ARPHRD_IEEE802154 and
ARPHRD_IEEE802154_MONITOR should have wdev->ieee802154_ptr, where
ARPHRD_IEEE802154 is currently a node interface only.

Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

ieee802154: 6lowpan: register packet layer while open

This patch moves the open count handling while doing open of a lowpan
interface. We need the packet handler register at first when one lowpan
interface is up. There exists a small case when all lowpan interfaces
are down and the 802154 packet layer is still registered. To reduce some
overhead we will register the packet layer when the first lowpan
interface comes up and unregister when the last interface will become down.

Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

ieee802154: 6lowpan: change dev vars to wdev and ldev

Inside the IEEE 802.15.4 6LoWPAN subsystem we use two interfaces which
are wpan and lowpan interfaces. Instead of using always the variable
name "dev" for both we rename the "dev" variable to wdev which means the
wpan net_device and ldev which means a lowpan net_device. This avoids
confusing and always looking back to see which net_device is meant by
the variable name "dev".

Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net: 6lowpan: convert to using IFF_NO_QUEUE

Signed-off-by: Phil Sutter <phil@nwl.cc>
Cc: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ieee802154: 6lowpan: fix packet layer registration

This patch fixes 802.15.4 packet layer registration when mutliple
lowpan interfaces will be added. We need to register the packet layer at
the first lowpan interface and deregister it at the last interface. This
done by open_count variable which is protected by rtnl.

Additional do a quiet fix by adding dev_put(real_dev) when netdev
registration fails, which fix the refcount for the wpan dev.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

6lowpan: add generic 6lowpan netdev private data

This patch introduced the 6lowpan netdev private data struct. We name it
lowpan_priv and it's placed at the beginning of netdev private data. All
lowpan interfaces should allocate this room at first of netdev private
data. 6LoWPAN LL private data can be allocate by additional netdev private
data, e.g. dev->priv_size should be "sizeof(struct lowpan_priv) +
sizeof(LL_LOWPAN_PRIVATE_DATA)".

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

ieee802154: 6lowpan: remove multiple lowpan per wpan support

We currently supports multiple lowpan interfaces per wpan interface. I
never saw any use case into such functionality. We drop this feature now
because it's much easier do deal with address changes inside the under
laying wpan interface.

This patch removes the multiple lowpan interface and adds a lowpan_dev
netdev pointer into the wpan_dev, if this pointer isn't null the wpan
interface belongs to the assigned lowpan interface.

Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Tested-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

mac802154: remove mib lock

This patch removes the mib lock. The new locking mechanism is to protect
the mib values with the rtnl lock. Note that this isn't always necessary
if we have an interface up the most mib values are readonly (e.g.
address settings). With this behaviour we can remove locking in
hotpath like frame parsing completely. It depends on context if we need
to hold the rtnl lock or not, this makes the callbacks of
ieee802154_mlme_ops unnecessary because these callbacks hols always the
locks.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

mac802154: use atomic ops for sequence incrementation

This patch will use atomic operations for sequence number incrementation
while MAC header generation. Upper layers like af_802154 or 6LoWPAN
could call this function in a parallel context while generating 802.15.4
MAC header before queuing into wpan interfaces transmit queue.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

ieee802154: 6lowpan: fix ARPHRD to ARPHRD_6LOWPAN

Currently there exists two interface types with ARPHRD_IEEE802154. These
are the 802.15.4 interfaces and 802.15.4 6LoWPAN interfaces. This is
more a bug because some userspace applications checks on this value like
wireshark. This occurs that wireshark will always try to parse a lowpan
interface as 802.15.4 frames. With ARPHRD_6LOWPAN wireshark will parse
it as IPv6 frames which is correct.

Much applications checks on this value to readout the EUI64 mac address
which should be the same for ARPHRD_6LOWPAN. BTLE 6LoWPAN and ieee802154
6LoWPAN will share now the same ARPHRD.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

ieee802154: fix netns settings

6LoWPAN currently doesn't supports x-netns and works only in init_net.

With this patch, we ensure that:
- the wpan interface cannot be moved to another netns;
- the 6lowpan interface cannot be moved to another netns;
- the wpan interface is in the same netns than the 6lowpan interface;
- the 6lowpan interface is in init_net.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

ieee802154: 6lowpan: rename to core

This patch renames the 6lowpan_rtnl.c file to core.c. 6lowpan_rtnl.c
contains functionality to put all 802.15.4 6LoWPAN functionality
together.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>