net: mrp: move struct definitions out of uapi

None of these are actually used in the kernel/userspace interface -
there's a userspace component of implementing MRP, and userspace will
need to construct certain frames to put on the wire, but there's no
reason the kernel should provide the relevant definitions in a UAPI
header.

In fact, some of those definitions were broken until previous commit,
so only keep the few that are actually referenced in the kernel code,
and move them to the br_private_mrp.h header.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: mrp: fix definitions of MRP test packets

Wireshark says that the MRP test packets cannot be decoded - and the
reason for that is that there's a two-byte hole filled with garbage
between the "transitions" and "timestamp" members.

So Wireshark decodes the two garbage bytes and the top two bytes of
the timestamp written by the kernel as the timestamp value (which thus
fluctuates wildly), and interprets the lower two bytes of the
timestamp as a new (type, length) pair, which is of course broken.

Even though this makes the timestamp field in the struct unaligned, it
actually makes it end up on a 32 bit boundary in the frame as mandated
by the standard, since it is preceded by a two byte TLV header.

The struct definitions live under include/uapi/, but they are not
really part of any kernel<->userspace API/ABI, so fixing the
definitions by adding the packed attribute should not cause any
compatibility issues.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

bridge: mrp: Implement LC mode for MRP

Extend MRP to support LC mode(link check) for the interconnect port.
This applies only to the interconnect ring.

Opposite to RC mode(ring check) the LC mode is using CFM frames to
detect when the link goes up or down and based on that the userspace
will need to react.
One advantage of the LC mode over RC mode is that there will be fewer
frames in the normal rings. Because RC mode generates InTest on all
ports while LC mode sends CFM frame only on the interconnect port.

All 4 nodes part of the interconnect ring needs to have the same mode.
And it is not possible to have running LC and RC mode at the same time
on a node.

Whenever the MIM starts it needs to detect the status of the other 3
nodes in the interconnect ring so it would send a frame called
InLinkStatus, on which the clients needs to reply with their link
status.

This patch adds InLinkStatus frame type and extends existing rules on
how to forward this frame.

Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Link: https://lore.kernel.org/r/20201124082525.273820-1-horatiu.vultur@microchip.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

bridge: uapi: mrp: Extend MRP attributes for MRP interconnect

Extend the existing MRP netlink attributes to allow to configure MRP
Interconnect:

IFLA_BRIDGE_MRP_IN_ROLE - the parameter type is br_mrp_in_role which
contains the interconnect id, the ring id, the interconnect role(MIM
or MIC) and the port ifindex that represents the interconnect port.

IFLA_BRIDGE_MRP_IN_STATE - the parameter type is br_mrp_in_state which
contains the interconnect id and the interconnect state.

IFLA_BRIDGE_MRP_IN_TEST - the parameter type is br_mrp_start_in_test
which contains the interconnect id, the interval at which to send
MRP_InTest frames, how many test frames can be missed before declaring
the interconnect ring open and the period which represents for how long
to send MRP_InTest frames.

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bridge: uapi: mrp: Fix MRP_PORT_ROLE

Currently the MRP_PORT_ROLE_NONE has the value 0x2 but this is in conflict
with the IEC 62439-2 standard. The standard defines the following port
roles: primary (0x0), secondary(0x1), interconnect(0x2).
Therefore remove the port role none.

Fixes: 4714d13791f831 ("bridge: uapi: mrp: Add mrp attributes.")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bridge: mrp: Add support for role MRA

A node that has the MRA role, it can behave as MRM or MRC.

Initially it starts as MRM and sends MRP_Test frames on both ring ports.
If it detects that there are MRP_Test send by another MRM, then it
checks if these frames have a lower priority than itself. In this case
it would send MRP_Nack frames to notify the other node that it needs to
stop sending MRP_Test frames.
If it receives a MRP_Nack frame then it stops sending MRP_Test frames
and starts to behave as a MRC but it would continue to monitor the
MRP_Test frames send by MRM. If at a point the MRM stops to send
MRP_Test frames it would get the MRM role and start to send MRP_Test
frames.

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bridge: mrp: Update MRP frame type

Replace u16/u32 with be16/be32 in the MRP frame types.
This fixes sparse warnings like:
warning: cast to restricted __be16

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bridge: uapi: mrp: Add mrp attributes.

Add new nested netlink attribute to configure the MRP. These attributes are used
by the userspace to add/delete/configure MRP instances and by the kernel to
notify the userspace when the MRP ring gets open/closed. MRP nested attribute
has the following attributes:

IFLA_BRIDGE_MRP_INSTANCE - the parameter type is br_mrp_instance which contains
the instance id, and the ifindex of the two ports. The ports can't be part of
multiple instances. This is used to create/delete MRP instances.

IFLA_BRIDGE_MRP_PORT_STATE - the parameter type is u32. Which can be forwarding,
blocking or disabled.

IFLA_BRIDGE_MRP_PORT_ROLE - the parameter type is br_mrp_port_role which
contains the instance id and the role. The role can be primary or secondary.

IFLA_BRIDGE_MRP_RING_STATE - the parameter type is br_mrp_ring_state which
contains the instance id and the state. The state can be open or closed.

IFLA_BRIDGE_MRP_RING_ROLE - the parameter type is br_mrp_ring_role which
contains the instance id and the ring role. The role can be MRM or MRC.

IFLA_BRIDGE_MRP_START_TEST - the parameter type is br_mrp_start_test which
contains the instance id, the interval at which to send the MRP_Test frames,
how many test frames can be missed before declaring the ring open and the
period which represent for how long to send the test frames.

Also add the file include/uapi/linux/mrp_bridge.h which defines all the types
used by MRP that are also needed by the userpace.

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>