According to the synchronization rules for .ndo_get_stats() as seen in
Documentation/networking/netdevices.rst, acquiring a plain spin_lock()
should not be illegal, but the bridge driver implementation makes it so.
After running these commands, I am being faced with the following
lockdep splat:
$ ip link add link swp0 name macsec0 type macsec encrypt on && ip link set swp0 up
$ ip link add dev br0 type bridge vlan_filtering 1 && ip link set br0 up
$ ip link set macsec0 master br0 && ip link set macsec0 up
========================================================
WARNING: possible irq lock inversion dependency detected
6.4.0-04295-g31b577b4bd4a #603 Not tainted
--------------------------------------------------------
swapper/1/0 just changed the state of lock:
ffff6bd348724cd8 (&br->lock){+.-.}-{3:3}, at: br_forward_delay_timer_expired+0x34/0x198
but this lock took another, SOFTIRQ-unsafe lock in the past:
(&ocelot->stats_lock){+.+.}-{3:3}
and interrupts could create inverse lock ordering between them.
other info that might help us debug this:
Chain exists of:
&br->lock --> &br->hash_lock --> &ocelot->stats_lock
Possible interrupt unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&ocelot->stats_lock);
local_irq_disable();
lock(&br->lock);
lock(&br->hash_lock);
<Interrupt>
lock(&br->lock);
*** DEADLOCK ***
(details about the 3 locks skipped)
swp0 is instantiated by drivers/net/dsa/ocelot/felix.c, and this
only matters to the extent that its .ndo_get_stats64() method calls
spin_lock(&ocelot->stats_lock).
Documentation/locking/lockdep-design.rst says:
| A lock is irq-safe means it was ever used in an irq context, while a lock
| is irq-unsafe means it was ever acquired with irq enabled.
(...)
| Furthermore, the following usage based lock dependencies are not allowed
| between any two lock-classes::
|
| <hardirq-safe> -> <hardirq-unsafe>
| <softirq-safe> -> <softirq-unsafe>
Lockdep marks br->hash_lock as softirq-safe, because it is sometimes
taken in softirq context (for example br_fdb_update() which runs in
NET_RX softirq), and when it's not in softirq context it blocks softirqs
by using spin_lock_bh().
Lockdep marks ocelot->stats_lock as softirq-unsafe, because it never
blocks softirqs from running, and it is never taken from softirq
context. So it can always be interrupted by softirqs.
There is a call path through which a function that holds br->hash_lock:
fdb_add_hw_addr() will call a function that acquires ocelot->stats_lock:
ocelot_port_get_stats64(). This can be seen below:
ocelot_port_get_stats64+0x3c/0x1e0
felix_get_stats64+0x20/0x38
dsa_slave_get_stats64+0x3c/0x60
dev_get_stats+0x74/0x2c8
rtnl_fill_stats+0x4c/0x150
rtnl_fill_ifinfo+0x5cc/0x7b8
rtmsg_ifinfo_build_skb+0xe4/0x150
rtmsg_ifinfo+0x5c/0xb0
__dev_notify_flags+0x58/0x200
__dev_set_promiscuity+0xa0/0x1f8
dev_set_promiscuity+0x30/0x70
macsec_dev_change_rx_flags+0x68/0x88
__dev_set_promiscuity+0x1a8/0x1f8
__dev_set_rx_mode+0x74/0xa8
dev_uc_add+0x74/0xa0
fdb_add_hw_addr+0x68/0xd8
fdb_add_local+0xc4/0x110
br_fdb_add_local+0x54/0x88
br_add_if+0x338/0x4a0
br_add_slave+0x20/0x38
do_setlink+0x3a4/0xcb8
rtnl_newlink+0x758/0x9d0
rtnetlink_rcv_msg+0x2f0/0x550
netlink_rcv_skb+0x128/0x148
rtnetlink_rcv+0x24/0x38
the plain English explanation for it is:
The macsec0 bridge port is created without p->flags & BR_PROMISC,
because it is what br_manage_promisc() decides for a VLAN filtering
bridge with a single auto port.
As part of the br_add_if() procedure, br_fdb_add_local() is called for
the MAC address of the device, and this results in a call to
dev_uc_add() for macsec0 while the softirq-safe br->hash_lock is taken.
Because macsec0 does not have IFF_UNICAST_FLT, dev_uc_add() ends up
calling __dev_set_promiscuity() for macsec0, which is propagated by its
implementation, macsec_dev_change_rx_flags(), to the lower device: swp0.
This triggers the call path:
dev_set_promiscuity(swp0)
-> rtmsg_ifinfo()
-> dev_get_stats()
-> ocelot_port_get_stats64()
with a calling context that lockdep doesn't like (br->hash_lock held).
Normally we don't see this, because even though many drivers that can be
bridge ports don't support IFF_UNICAST_FLT, we need a driver that
(a) doesn't support IFF_UNICAST_FLT, *and*
(b) it forwards the IFF_PROMISC flag to another driver, and
(c) *that* driver implements ndo_get_stats64() using a softirq-unsafe
spinlock.
Condition (b) is necessary because the first __dev_set_rx_mode() calls
__dev_set_promiscuity() with "bool notify=false", and thus, the
rtmsg_ifinfo() code path won't be entered.
The same criteria also hold true for DSA switches which don't report
IFF_UNICAST_FLT. When the DSA master uses a spin_lock() in its
ndo_get_stats64() method, the same lockdep splat can be seen.
I think the deadlock possibility is real, even though I didn't reproduce
it, and I'm thinking of the following situation to support that claim:
fdb_add_hw_addr() runs on a CPU A, in a context with softirqs locally
disabled and br->hash_lock held, and may end up attempting to acquire
ocelot->stats_lock.
In parallel, ocelot->stats_lock is currently held by a thread B (say,
ocelot_check_stats_work()), which is interrupted while holding it by a
softirq which attempts to lock br->hash_lock.
Thread B cannot make progress because br->hash_lock is held by A. Whereas
thread A cannot make progress because ocelot->stats_lock is held by B.
When taking the issue at face value, the bridge can avoid that problem
by simply making the ports promiscuous from a code path with a saner
calling context (br->hash_lock not held). A bridge port without
IFF_UNICAST_FLT is going to become promiscuous as soon as we call
dev_uc_add() on it (which we do unconditionally), so why not be
preemptive and make it promiscuous right from the beginning, so as to
not be taken by surprise.
With this, we've broken the links between code that holds br->hash_lock
or br->lock and code that calls into the ndo_change_rx_flags() or
ndo_get_stats64() ops of the bridge port.
Fixes: 2796d0c648 ("bridge: Automatically manage port promiscuous mode.")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The bridge driver gates the neighbor suppression code behind an internal
per-bridge flag called 'BROPT_NEIGH_SUPPRESS_ENABLED'. The flag is set
when at least one bridge port has neighbor suppression enabled.
As a preparation for per-{Port, VLAN} neighbor suppression, make sure
the global flag is also set if per-{Port, VLAN} neighbor suppression is
enabled. That is, when the 'BR_NEIGH_VLAN_SUPPRESS' flag is set on at
least one bridge port.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since commit ee6d3dd4ed ("driver core: make kobj_type constant.")
the driver core allows the usage of const struct kobj_type.
Take advantage of this to constify the structure definition to prevent
modification at runtime.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The call, kobject_get_ownership(), does not modify the kobject passed
into it, so make it const. This propagates down into the kobj_type
function callbacks so make the kobject passed into them also const,
ensuring that nothing in the kobject is being changed here.
This helps make it more obvious what calls and callbacks do, and do not,
modify structures passed to them.
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Roopa Prabhu <roopa@nvidia.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: linux-nfs@vger.kernel.org
Cc: bridge@lists.linux-foundation.org
Cc: netdev@vger.kernel.org
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/r/20221121094649.1556002-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As 2.5G, 5G ethernet ports are more common and affordable,
these ports are being used in LAN bridge devices.
STP port_cost() is missing path_cost assignment for these link speeds,
causes highest cost 100 being used.
This result in lower speed port being picked
when there is loop between 5G and 1G ports.
Original path_cost: 10G=2, 1G=4, 100m=19, 10m=100
Adjusted path_cost: 10G=2, 5G=3, 2.5G=4, 1G=5, 100m=19, 10m=100
speed greater than 10G = 1
Signed-off-by: Steven Hsieh <steven.hsieh@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When DSA gains support for multiple CPU ports in a LAG, it will become
mandatory to monitor the changeupper events for the DSA master.
In fact, there are already some restrictions to be imposed in that area,
namely that a DSA master cannot be a bridge port except in some special
circumstances.
Centralize the restrictions at the level of the DSA layer as a
preliminary step.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Netdev reference helpers have a dev_ prefix for historic
reasons. Renaming the old helpers would be too much churn
but we can rename the tracking ones which are relatively
recent and should be the default for new code.
Rename:
dev_hold_track() -> netdev_hold()
dev_put_track() -> netdev_put()
dev_replace_track() -> netdev_ref_replace()
Link: https://lore.kernel.org/r/20220608043955.919359-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Drivers should call the TSO setting helper, GSO is controllable
by user space.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
I left one dev_put() in br_add_if() error path and sure enough
syzbot found its way.
As the tracker is allocated in new_nbp(), we must make sure
to properly free it.
We have to call dev_put_track(dev, &p->dev_tracker) before
@p object is freed, of course. This is not an issue because
br_add_if() owns a reference on @dev.
Fixes: b2dcdc7f73 ("net: bridge: add net device refcount tracker")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
dev->gso_max_segs is written under RTNL protection, or when the device is
not yet visible, but is read locklessly.
Add netif_set_gso_max_segs() helper.
Add the READ_ONCE()/WRITE_ONCE() pairs, and use netif_set_gso_max_segs()
where we can to better document what is going on.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
dev->gso_max_size is written under RTNL protection, or when the device is
not yet visible, but is read locklessly.
Add the READ_ONCE()/WRITE_ONCE() pairs, and use netif_set_gso_max_size()
where we can to better document what is going on.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The 'inuse' bitmap is local to this function. So we can use the
non-atomic '__set_bit()' to save a few cycles.
While at it, also remove some useless {}.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
br_fdb_insert() is a wrapper over fdb_insert() that also takes the
bridge hash_lock.
With fdb_insert() being renamed to fdb_add_local(), rename
br_fdb_insert() to br_fdb_add_local().
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make use of netdev helper functions to improve code readability.
Replace 'dev->priv_flags & IFF_EBRIDGE' with netif_is_bridge_master(dev).
Signed-off-by: Kyungrok Chung <acadx0@gmail.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Before commit ad2f99aedf ("net: bridge: move bridge ioctls out of
.ndo_do_ioctl") the bridge ioctl calls were divided in two parts:
one was deviceless called by sock_ioctl and didn't expect rtnl to be held,
the other was with a device called by dev_ifsioc() and expected rtnl to be
held. After the commit above they were united in a single ioctl stub, but
it didn't take care of the locking expectations.
For sock_ioctl now we acquire (1) br_ioctl_mutex, (2) rtnl
and for dev_ifsioc we acquire (1) rtnl, (2) br_ioctl_mutex
The fix is to get a refcnt on the netdev for dev_ifsioc calls and drop rtnl
then to reacquire it in the bridge ioctl stub after br_ioctl_mutex has
been acquired. That will avoid playing locking games and make the rules
straight-forward: we always take br_ioctl_mutex first, and then rtnl.
Reported-by: syzbot+34fe5894623c4ab1b379@syzkaller.appspotmail.com
Fixes: ad2f99aedf ("net: bridge: move bridge ioctls out of .ndo_do_ioctl")
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
On reception of an skb, the bridge checks if it was marked as 'already
forwarded in hardware' (checks if skb->offload_fwd_mark == 1), and if it
is, it assigns the source hardware domain of that skb based on the
hardware domain of the ingress port. Then during forwarding, it enforces
that the egress port must have a different hardware domain than the
ingress one (this is done in nbp_switchdev_allowed_egress).
Non-switchdev drivers don't report any physical switch id (neither
through devlink nor .ndo_get_port_parent_id), therefore the bridge
assigns them a hardware domain of 0, and packets coming from them will
always have skb->offload_fwd_mark = 0. So there aren't any restrictions.
Problems appear due to the fact that DSA would like to perform software
fallback for bonding and team interfaces that the physical switch cannot
offload.
+-- br0 ---+
/ / | \
/ / | \
/ | | bond0
/ | | / \
swp0 swp1 swp2 swp3 swp4
There, it is desirable that the presence of swp3 and swp4 under a
non-offloaded LAG does not preclude us from doing hardware bridging
beteen swp0, swp1 and swp2. The bandwidth of the CPU is often times high
enough that software bridging between {swp0,swp1,swp2} and bond0 is not
impractical.
But this creates an impossible paradox given the current way in which
port hardware domains are assigned. When the driver receives a packet
from swp0 (say, due to flooding), it must set skb->offload_fwd_mark to
something.
- If we set it to 0, then the bridge will forward it towards swp1, swp2
and bond0. But the switch has already forwarded it towards swp1 and
swp2 (not to bond0, remember, that isn't offloaded, so as far as the
switch is concerned, ports swp3 and swp4 are not looking up the FDB,
and the entire bond0 is a destination that is strictly behind the
CPU). But we don't want duplicated traffic towards swp1 and swp2, so
it's not ok to set skb->offload_fwd_mark = 0.
- If we set it to 1, then the bridge will not forward the skb towards
the ports with the same switchdev mark, i.e. not to swp1, swp2 and
bond0. Towards swp1 and swp2 that's ok, but towards bond0? It should
have forwarded the skb there.
So the real issue is that bond0 will be assigned the same hardware
domain as {swp0,swp1,swp2}, because the function that assigns hardware
domains to bridge ports, nbp_switchdev_add(), recurses through bond0's
lower interfaces until it finds something that implements devlink (calls
dev_get_port_parent_id with bool recurse = true). This is a problem
because the fact that bond0 can be offloaded by swp3 and swp4 in our
example is merely an assumption.
A solution is to give the bridge explicit hints as to what hardware
domain it should use for each port.
Currently, the bridging offload is very 'silent': a driver registers a
netdevice notifier, which is put on the netns's notifier chain, and
which sniffs around for NETDEV_CHANGEUPPER events where the upper is a
bridge, and the lower is an interface it knows about (one registered by
this driver, normally). Then, from within that notifier, it does a bunch
of stuff behind the bridge's back, without the bridge necessarily
knowing that there's somebody offloading that port. It looks like this:
ip link set swp0 master br0
|
v
br_add_if() calls netdev_master_upper_dev_link()
|
v
call_netdevice_notifiers
|
v
dsa_slave_netdevice_event
|
v
oh, hey! it's for me!
|
v
.port_bridge_join
What we do to solve the conundrum is to be less silent, and change the
switchdev drivers to present themselves to the bridge. Something like this:
ip link set swp0 master br0
|
v
br_add_if() calls netdev_master_upper_dev_link()
|
v bridge: Aye! I'll use this
call_netdevice_notifiers ^ ppid as the
| | hardware domain for
v | this port, and zero
dsa_slave_netdevice_event | if I got nothing.
| |
v |
oh, hey! it's for me! |
| |
v |
.port_bridge_join |
| |
+------------------------+
switchdev_bridge_port_offload(swp0, swp0)
Then stacked interfaces (like bond0 on top of swp3/swp4) would be
treated differently in DSA, depending on whether we can or cannot
offload them.
The offload case:
ip link set bond0 master br0
|
v
br_add_if() calls netdev_master_upper_dev_link()
|
v bridge: Aye! I'll use this
call_netdevice_notifiers ^ ppid as the
| | switchdev mark for
v | bond0.
dsa_slave_netdevice_event | Coincidentally (or not),
| | bond0 and swp0, swp1, swp2
v | all have the same switchdev
hmm, it's not quite for me, | mark now, since the ASIC
but my driver has already | is able to forward towards
called .port_lag_join | all these ports in hw.
for it, because I have |
a port with dp->lag_dev == bond0. |
| |
v |
.port_bridge_join |
for swp3 and swp4 |
| |
+------------------------+
switchdev_bridge_port_offload(bond0, swp3)
switchdev_bridge_port_offload(bond0, swp4)
And the non-offload case:
ip link set bond0 master br0
|
v
br_add_if() calls netdev_master_upper_dev_link()
|
v bridge waiting:
call_netdevice_notifiers ^ huh, switchdev_bridge_port_offload
| | wasn't called, okay, I'll use a
v | hwdom of zero for this one.
dsa_slave_netdevice_event : Then packets received on swp0 will
| : not be software-forwarded towards
v : swp1, but they will towards bond0.
it's not for me, but
bond0 is an upper of swp3
and swp4, but their dp->lag_dev
is NULL because they couldn't
offload it.
Basically we can draw the conclusion that the lowers of a bridge port
can come and go, so depending on the configuration of lowers for a
bridge port, it can dynamically toggle between offloaded and unoffloaded.
Therefore, we need an equivalent switchdev_bridge_port_unoffload too.
This patch changes the way any switchdev driver interacts with the
bridge. From now on, everybody needs to call switchdev_bridge_port_offload
and switchdev_bridge_port_unoffload, otherwise the bridge will treat the
port as non-offloaded and allow software flooding to other ports from
the same ASIC.
Note that these functions lay the ground for a more complex handshake
between switchdev drivers and the bridge in the future.
For drivers that will request a replay of the switchdev objects when
they offload and unoffload a bridge port (DSA, dpaa2-switch, ocelot), we
place the call to switchdev_bridge_port_unoffload() strategically inside
the NETDEV_PRECHANGEUPPER notifier's code path, and not inside
NETDEV_CHANGEUPPER. This is because the switchdev object replay helpers
need the netdev adjacency lists to be valid, and that is only true in
NETDEV_PRECHANGEUPPER.
Cc: Vadym Kochan <vkochan@marvell.com>
Cc: Taras Chornyi <tchornyi@marvell.com>
Cc: Ioana Ciornei <ioana.ciornei@nxp.com>
Cc: Lars Povlsen <lars.povlsen@microchip.com>
Cc: Steen Hegelund <Steen.Hegelund@microchip.com>
Cc: UNGLinuxDriver@microchip.com
Cc: Claudiu Manoil <claudiu.manoil@nxp.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch: regression
Acked-by: Ioana Ciornei <ioana.ciornei@nxp.com> # dpaa2-switch
Tested-by: Horatiu Vultur <horatiu.vultur@microchip.com> # ocelot-switch
Signed-off-by: David S. Miller <davem@davemloft.net>
Since hwdoms have only been used thus far for equality comparisons, the
bridge has used the simplest possible assignment policy; using a
counter to keep track of the last value handed out.
With the upcoming transmit offloading, we need to perform set
operations efficiently based on hwdoms, e.g. we want to answer
questions like "has this skb been forwarded to any port within this
hwdom?"
Move to a bitmap-based allocation scheme that recycles hwdoms once all
members leaves the bridge. This means that we can use a single
unsigned long to keep track of the hwdoms that have received an skb.
v1->v2: convert the typedef DECLARE_BITMAP(br_hwdom_map_t, BR_HWDOM_MAX)
into a plain unsigned long.
v2->v6: none
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Before this change, four related - but distinct - concepts where named
offload_fwd_mark:
- skb->offload_fwd_mark: Set by the switchdev driver if the underlying
hardware has already forwarded this frame to the other ports in the
same hardware domain.
- nbp->offload_fwd_mark: An idetifier used to group ports that share
the same hardware forwarding domain.
- br->offload_fwd_mark: Counter used to make sure that unique IDs are
used in cases where a bridge contains ports from multiple hardware
domains.
- skb->cb->offload_fwd_mark: The hardware domain on which the frame
ingressed and was forwarded.
Introduce the term "hardware forwarding domain" ("hwdom") in the
bridge to denote a set of ports with the following property:
If an skb with skb->offload_fwd_mark set, is received on a port
belonging to hwdom N, that frame has already been forwarded to all
other ports in hwdom N.
By decoupling the name from "offload_fwd_mark", we can extend the
term's definition in the future - e.g. to add constraints that
describe expected egress behavior - without overloading the meaning of
"offload_fwd_mark".
- nbp->offload_fwd_mark thus becomes nbp->hwdom.
- br->offload_fwd_mark becomes br->last_hwdom.
- skb->cb->offload_fwd_mark becomes skb->cb->src_hwdom. The slight
change in naming here mandates a slight change in behavior of the
nbp_switchdev_frame_mark() function. Previously, it only set this
value in skb->cb for packets with skb->offload_fwd_mark true (ones
which were forwarded in hardware). Whereas now we always track the
incoming hwdom for all packets coming from a switchdev (even for the
packets which weren't forwarded in hardware, such as STP BPDUs, IGMP
reports etc). As all uses of skb->cb->offload_fwd_mark were already
gated behind checks of skb->offload_fwd_mark, this will not introduce
any functional change, but it paves the way for future changes where
the ingressing hwdom must be known for frames coming from a switchdev
regardless of whether they were forwarded in hardware or not
(basically, if the skb comes from a switchdev, skb->cb->src_hwdom now
always tracks which one).
A typical example where this is relevant: the switchdev has a fixed
configuration to trap STP BPDUs, but STP is not running on the bridge
and the group_fwd_mask allows them to be forwarded. Say we have this
setup:
br0
/ | \
/ | \
swp0 swp1 swp2
A BPDU comes in on swp0 and is trapped to the CPU; the driver does not
set skb->offload_fwd_mark. The bridge determines that the frame should
be forwarded to swp{1,2}. It is imperative that forward offloading is
_not_ allowed in this case, as the source hwdom is already "poisoned".
Recording the source hwdom allows this case to be handled properly.
v2->v3: added code comments
v3->v6: none
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since commit 2796d0c648 ("bridge: Automatically manage
port promiscuous mode.")
bridges with `vlan_filtering 1` and only 1 auto-port don't
set IFF_PROMISC for unicast-filtering-capable ports.
Normally on port changes `br_manage_promisc` is called to
update the promisc flags and unicast filters if necessary,
but it cannot distinguish between *new* ports and ones
losing their promisc flag, and new ports end up not
receiving the MAC address list.
Fix this by calling `br_fdb_sync_static` in `br_add_if`
after the port promisc flags are updated and the unicast
filter was supposed to have been filled.
Fixes: 2796d0c648 ("bridge: Automatically manage port promiscuous mode.")
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is the first commit of the implementation of the CFM protocol
according to 802.1Q section 12.14.
It contains MEP instance create, delete and configuration.
Connectivity Fault Management (CFM) comprises capabilities for
detecting, verifying, and isolating connectivity failures in
Virtual Bridged Networks. These capabilities can be used in
networks operated by multiple independent organizations, each
with restricted management access to each others equipment.
CFM functions are partitioned as follows:
- Path discovery
- Fault detection
- Fault verification and isolation
- Fault notification
- Fault recovery
Interface consists of these functions:
br_cfm_mep_create()
br_cfm_mep_delete()
br_cfm_mep_config_set()
br_cfm_cc_config_set()
br_cfm_cc_peer_mep_add()
br_cfm_cc_peer_mep_remove()
A MEP instance is created by br_cfm_mep_create()
-It is the Maintenance association End Point
described in 802.1Q section 19.2.
-It is created on a specific level (1-7) and is assuring
that no CFM frames are passing through this MEP on lower levels.
-It initiates and validates CFM frames on its level.
-It can only exist on a port that is related to a bridge.
-Attributes given cannot be changed until the instance is
deleted.
A MEP instance can be deleted by br_cfm_mep_delete().
A created MEP instance has attributes that can be
configured by br_cfm_mep_config_set().
A MEP Continuity Check feature can be configured by
br_cfm_cc_config_set()
The Continuity Check Receiver state machine can be
enabled and disabled.
According to 802.1Q section 19.2.8
A MEP can have Peer MEPs added and removed by
br_cfm_cc_peer_mep_add() and br_cfm_cc_peer_mep_remove()
The Continuity Check feature can maintain connectivity
status on each added Peer MEP.
Signed-off-by: Henrik Bjoernlund <henrik.bjoernlund@microchip.com>
Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit 8db0a2ee2c ("net: bridge: reject DSA-enabled master netdevices
as bridge members") added a special check in br_if.c in order to check
for a DSA master network device with a tagging protocol configured. This
was done because back then, such devices, once enslaved in a bridge
would become inoperative and would not pass DSA tagged traffic anymore
due to br_handle_frame returning RX_HANDLER_CONSUMED.
But right now we have valid use cases which do require bridging of DSA
masters. One such example is when the DSA master ports are DSA switch
ports themselves (in a disjoint tree setup). This should be completely
equivalent, functionally speaking, from having multiple DSA switches
hanging off of the ports of a switchdev driver. So we should allow the
enslaving of DSA tagged master network devices.
Instead of the regular br_handle_frame(), install a new function
br_handle_frame_dummy() on these DSA masters, which returns
RX_HANDLER_PASS in order to call into the DSA specific tagging protocol
handlers, and lift the restriction from br_add_if.
Suggested-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Suggested-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
To integrate MRP into the bridge, the bridge needs to do the following:
- detect if the MRP frame was received on MRP ring port in that case it would be
processed otherwise just forward it as usual.
- enable parsing of MRP
- before whenever the bridge was set up, it would set all the ports in
forwarding state. Add an extra check to not set ports in forwarding state if
the port is an MRP ring port. The reason of this change is that if the MRP
instance initially sets the port in blocked state by setting the bridge up it
would overwrite this setting.
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 3029 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently error return from kobject_init_and_add() is not followed by a
call to kobject_put(). This means there is a memory leak. We currently
set p to NULL so that kfree() may be called on it as a noop, the code is
arguably clearer if we move the kfree() up closer to where it is
called (instead of after goto jump).
Remove a goto label 'err1' and jump to call to kobject_put() in error
return from kobject_init_and_add() fixing the memory leak. Re-name goto
label 'put_back' to 'err1' now that we don't use err1, following current
nomenclature (err1, err2 ...). Move call to kfree out of the error
code at bottom of function up to closer to where memory was allocated.
Add comment to clarify call to kfree().
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Replace the br_port_exists() macro with its twin from netdevice.h
CC: Roopa Prabhu <roopa@cumulusnetworks.com>
CC: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a port is attached to a bridge, the address of the bridge in
question may change as well. Even if it would not change at this
point (because the current bridge address is lower), it might end up
changing later as a result of detach of another port, which can't be
vetoed.
Therefore issue NETDEV_PRE_CHANGEADDR regardless of whether the address
will be used at this point or not, and make sure all involved parties
would agree with the change.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ndo_bridge_setlink has been updated in the previous patch to have extack
available, and changelink RTNL op has had this argument since the time
extack was added. Propagate both through the bridge driver to eventually
reach br_switchdev_port_vlan_add(), where it will be used by subsequent
patches.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Acked-by: Ivan Vecera <ivecera@redhat.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Allow querying bridge port flags so that drivers capable of performing
VxLAN learning will update the bridge driver only if learning is enabled
on its bridge port corresponding to the VxLAN device.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Convert the last remaining bool option to a bit thus reducing the overall
net_bridge size further by 8 bytes.
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Switch to bitmap_zalloc() to show clearly what we are allocating.
Besides that it returns pointer of bitmap type instead of opaque void *.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds a new port attribute - IFLA_BRPORT_BACKUP_PORT, which
allows to set a backup port to be used for known unicast traffic if the
port has gone carrier down. The backup pointer is rcu protected and set
only under RTNL, a counter is maintained so when deleting a port we know
how many other ports reference it as a backup and we remove it from all.
Also the pointer is in the first cache line which is hot at the time of
the check and thus in the common case we only add one more test.
The backup port will be used only for the non-flooding case since
it's a part of the bridge and the flooded packets will be forwarded to it
anyway. To remove the forwarding just send a 0/non-existing backup port.
This is used to avoid numerous scalability problems when using MLAG most
notably if we have thousands of fdbs one would need to change all of them
on port carrier going down which takes too long and causes a storm of fdb
notifications (and again when the port comes back up). In a Multi-chassis
Link Aggregation setup usually hosts are connected to two different
switches which act as a single logical switch. Those switches usually have
a control and backup link between them called peerlink which might be used
for communication in case a host loses connectivity to one of them.
We need a fast way to failover in case a host port goes down and currently
none of the solutions (like bond) cannot fulfill the requirements because
the participating ports are actually the "master" devices and must have the
same peerlink as their backup interface and at the same time all of them
must participate in the bridge device. As Roopa noted it's normal practice
in routing called fast re-route where a precalculated backup path is used
when the main one is down.
Another use case of this is with EVPN, having a single vxlan device which
is backup of every port. Due to the nature of master devices it's not
currently possible to use one device as a backup for many and still have
all of them participate in the bridge (which is master itself).
More detailed information about MLAG is available at the link below.
https://docs.cumulusnetworks.com/display/DOCS/Multi-Chassis+Link+Aggregation+-+MLAG
Further explanation and a diagram by Roopa:
Two switches acting in a MLAG pair are connected by the peerlink
interface which is a bridge port.
the config on one of the switches looks like the below. The other
switch also has a similar config.
eth0 is connected to one port on the server. And the server is
connected to both switches.
br0 -- team0---eth0
|
-- switch-peerlink
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When creating various bridge objects in /sys/class/net/... make sure
that they belong to the container's owner instead of global root (if
they belong to a container/namespace).
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While handling netdevice events, br_device_event() sometimes uses
br_stp_(disable|enable)_port which unconditionally send a notification,
but then a second notification for the same event is sent at the end of
the br_device_event() function. To avoid sending duplicate notifications
in such cases, check if one has already been sent (i.e.
br_stp_enable/disable_port have been called).
The patch is based on a change by Satish Ashok.
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When we set a bond slave's master to bridge via ioctl, we only check
the IFF_BRIDGE_PORT flag. Although we will find the slave's real master
at netdev_master_upper_dev_link() later, it already does some settings
and allocates some resources. It would be better to return as early
as possible.
v1 -> v2:
use netdev_master_upper_dev_get() instead of netdev_has_any_upper_dev()
to check if we have a master, because not all upper devs are masters,
e.g. vlan device.
Reported-by: syzbot+de73361ee4971b6e6f75@syzkaller.appspotmail.com
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As Roopa noted today the biggest source of problems when configuring
bridge and ports is that the bridge MTU keeps changing automatically on
port events (add/del/changemtu). That leads to inconsistent behaviour
and network config software needs to chase the MTU and fix it on each
such event. Let's improve on that situation and allow for the user to
set any MTU within ETH_MIN/MAX limits, but once manually configured it
is the user's responsibility to keep it correct afterwards.
In case the MTU isn't manually set - the behaviour reverts to the
previous and the bridge follows the minimum MTU.
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Recently the bridge was changed to automatically set maximum MTU on port
events (add/del/changemtu) when vlan filtering is enabled, but that
actually changes behaviour in a way which breaks some setups and can lead
to packet drops. In order to still allow that maximum to be set while being
compatible, we add the ability for the user to tune the bridge MTU up to
the maximum when vlan filtering is enabled, but that has to be done
explicitly and all port events (add/del/changemtu) lead to resetting that
MTU to the minimum as before.
Suggested-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We need to use br_vlan_enabled() helper otherwise we'll break builds
without bridge vlans:
net/bridge//br_if.c: In function ‘br_mtu’:
net/bridge//br_if.c:458:8: error: ‘const struct net_bridge’ has no
member named ‘vlan_enabled’
if (br->vlan_enabled)
^
net/bridge//br_if.c:462:1: warning: control reaches end of non-void
function [-Wreturn-type]
}
^
scripts/Makefile.build:324: recipe for target 'net/bridge//br_if.o'
failed
Fixes: 419d14af9e ("bridge: Allow max MTU when multiple VLANs present")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If the bridge is allowing multiple VLANs, some VLANs may have
different MTUs. Instead of choosing the minimum MTU for the
bridge interface, choose the maximum MTU of the bridge members.
With this the user only needs to set a larger MTU on the member
ports that are participating in the large MTU VLANS.
Signed-off-by: Chas Williams <3chas3@gmail.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently the bridge device doesn't generate any notifications upon vlan
modifications on itself because it doesn't use the generic bridge
notifications.
With the recent changes we know if anything was modified in the vlan config
thus we can generate a notification when necessary for the bridge device
so add support to br_ifinfo_notify() similar to how other combined
functions are done - if port is present it takes precedence, otherwise
notify about the bridge. I've explicitly marked the locations where the
notification should be always for the port by setting bridge to NULL.
I've also taken the liberty to rearrange each modified function's local
variables in reverse xmas tree as well.
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds a new bridge port flag BR_NEIGH_SUPPRESS to
suppress arp and nd flood on bridge ports. It implements
rfc7432, section 10.
https://tools.ietf.org/html/rfc7432#section-10
for ethernet VPN deployments. It is similar to the existing
BR_PROXYARP* flags but has a few semantic differences to conform
to EVPN standard. Unlike the existing flags, this new flag suppresses
flood of all neigh discovery packets (arp and nd) to tunnel ports.
Supports both vlan filtering and non-vlan filtering bridges.
In case of EVPN, it is mainly used to avoid flooding
of arp and nd packets to tunnel ports like vxlan.
This patch adds netlink and sysfs support to set this bridge port
flag.
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pass extack arg to br_add_if. Add messages for a couple of failures
and pass arg to netdev_master_upper_dev_link.
Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add extack arg to netdev_upper_dev_link and netdev_master_upper_dev_link
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It's useful for drivers supporting bridge offload to be able to query
the bridge's VLAN filtering state.
Currently, upon enslavement to a bridge master, the offloading driver
will only learn about the bridge's VLAN filtering state after the bridge
device was already linked with its slave.
Being able to query the bridge's VLAN filtering state allows such
drivers to forbid enslavement in case resource couldn't be allocated for
a VLAN-aware bridge and also choose the correct initialization routine
for the enslaved port, which is dependent on the bridge type.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Support for l2 multicast flood control was added in commit b6cb5ac833
("net: bridge: add per-port multicast flood flag"). It allows broadcast
as it was introduced specifically for unknown multicast flood control.
But as broadcast is a special case of multicast, this may also need to
be disabled. For this purpose, introduce a flag to disable the flooding
of received l2 broadcasts. This approach is backwards compatible and
provides flexibility in filtering for the desired packet types.
Cc: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Mike Manning <mmanning@brocade.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
During removing a bridge device, if the bridge is still up, a new mdb entry
still can be added in br_multicast_add_group() after all mdb entries are
removed in br_multicast_dev_del(). Like the path:
mld_ifc_timer_expire ->
mld_sendpack -> ...
br_multicast_rcv ->
br_multicast_add_group
The new mp's timer will be set up. If the timer expires after the bridge
is freed, it may cause use-after-free panic in br_multicast_group_expired.
BUG: unable to handle kernel NULL pointer dereference at 0000000000000048
IP: [<ffffffffa07ed2c8>] br_multicast_group_expired+0x28/0xb0 [bridge]
Call Trace:
<IRQ>
[<ffffffff81094536>] call_timer_fn+0x36/0x110
[<ffffffffa07ed2a0>] ? br_mdb_free+0x30/0x30 [bridge]
[<ffffffff81096967>] run_timer_softirq+0x237/0x340
[<ffffffff8108dcbf>] __do_softirq+0xef/0x280
[<ffffffff8169889c>] call_softirq+0x1c/0x30
[<ffffffff8102c275>] do_softirq+0x65/0xa0
[<ffffffff8108e055>] irq_exit+0x115/0x120
[<ffffffff81699515>] smp_apic_timer_interrupt+0x45/0x60
[<ffffffff81697a5d>] apic_timer_interrupt+0x6d/0x80
Nikolay also found it would cause a memory leak - the mdb hash is
reallocated and not freed due to the mdb rehash.
unreferenced object 0xffff8800540ba800 (size 2048):
backtrace:
[<ffffffff816e2287>] kmemleak_alloc+0x67/0xc0
[<ffffffff81260bea>] __kmalloc+0x1ba/0x3e0
[<ffffffffa05c60ee>] br_mdb_rehash+0x5e/0x340 [bridge]
[<ffffffffa05c74af>] br_multicast_new_group+0x43f/0x6e0 [bridge]
[<ffffffffa05c7aa3>] br_multicast_add_group+0x203/0x260 [bridge]
[<ffffffffa05ca4b5>] br_multicast_rcv+0x945/0x11d0 [bridge]
[<ffffffffa05b6b10>] br_dev_xmit+0x180/0x470 [bridge]
[<ffffffff815c781b>] dev_hard_start_xmit+0xbb/0x3d0
[<ffffffff815c8743>] __dev_queue_xmit+0xb13/0xc10
[<ffffffff815c8850>] dev_queue_xmit+0x10/0x20
[<ffffffffa02f8d7a>] ip6_finish_output2+0x5ca/0xac0 [ipv6]
[<ffffffffa02fbfc6>] ip6_finish_output+0x126/0x2c0 [ipv6]
[<ffffffffa02fc245>] ip6_output+0xe5/0x390 [ipv6]
[<ffffffffa032b92c>] NF_HOOK.constprop.44+0x6c/0x240 [ipv6]
[<ffffffffa032bd16>] mld_sendpack+0x216/0x3e0 [ipv6]
[<ffffffffa032d5eb>] mld_ifc_timer_expire+0x18b/0x2b0 [ipv6]
This could happen when ip link remove a bridge or destroy a netns with a
bridge device inside.
With Nikolay's suggestion, this patch is to clean up bridge multicast in
ndo_uninit after bridge dev is shutdown, instead of br_dev_delete, so
that netif_running check in br_multicast_add_group can avoid this issue.
v1->v2:
- fix this issue by moving br_multicast_dev_del to ndo_uninit, instead
of calling dev_close in br_dev_delete.
(NOTE: Depends upon b6fe0440c6 ("bridge: implement missing ndo_uninit()"))
Fixes: e10177abf8 ("bridge: multicast: fix handling of temp and perm entries")
Reported-by: Jianwen Ji <jiji@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
