[Bridge] [PATCH RFC 0/7] net: bridge: cfm: Add support for Connectivity Fault Management(CFM)

Henrik Bjoernlund henrik.bjoernlund at microchip.com
Fri Sep 4 09:15:20 UTC 2020

Connectivity Fault Management (CFM) is defined in 802.1Q section 12.14.

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 other’s equipment.

CFM functions are partitioned as follows:
    — Path discovery
    — Fault detection
    — Fault verification and isolation
    — Fault notification
    — Fault recovery

The primary CFM protocol shims are called Maintenance Points (MPs).
A MP can be either a MEP or a MHF.
The MEP:
    -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 terminates/validates CFM frames on its level.
    -It can only exist on a port that is related to a bridge.
The MHF:
    -It is the Maintenance Domain Intermediate Point
     (MIP) Half Function (MHF) described in 802.1Q section 19.3.
    -It is created on a specific level (1-7).
    -It is extracting/injecting certain CFM frame on this level.
    -It can only exist on a port that is related to a bridge.
    -Currently not supported.

There are defined the following CFM protocol functions:
    -Continuity Check
    -Loopback. Currently not supported.
    -Linktrace. Currently not supported.

This CFM component supports create/delete of MEP instances and
configuration of the different CFM protocols. Also status information
can be fetched and delivered through notification due to defect status

The user interacts with CFM using the 'cfm' user space client program, the
client talks with the kernel using netlink. The kernel will try to offload
the requests to the HW via switchdev API (not implemented yet).

Any notification emitted by CFM from the kernel can be monitored in user
space by starting 'cfm_server' program.

Currently this 'cfm' and 'cfm_server' programs are standalone placed in a
cfm repository https://github.com/microchip-ung/cfm but it is considered
to integrate this into 'iproute2'.

Reviewed-by: Horatiu Vultur  <horatiu.vultur at microchip.com>
Signed-off-by: Henrik Bjoernlund  <henrik.bjoernlund at microchip.com>

Henrik Bjoernlund (7):
  net: bridge: extend the process of special frames
  bridge: cfm: Add BRIDGE_CFM to Kconfig.
  bridge: uapi: cfm: Added EtherType used by the CFM protocol.
  bridge: cfm: Kernel space implementation of CFM.
  bridge: cfm: Netlink Interface.
  bridge: cfm: Netlink Notifications.
  bridge: cfm: Bridge port remove.

 include/uapi/linux/cfm_bridge.h |  75 +++
 include/uapi/linux/if_bridge.h  | 125 +++++
 include/uapi/linux/if_ether.h   |   1 +
 include/uapi/linux/rtnetlink.h  |   2 +
 net/bridge/Kconfig              |  11 +
 net/bridge/Makefile             |   2 +
 net/bridge/br_cfm.c             | 936 ++++++++++++++++++++++++++++++++
 net/bridge/br_cfm_netlink.c     | 690 +++++++++++++++++++++++
 net/bridge/br_device.c          |   4 +
 net/bridge/br_if.c              |   1 +
 net/bridge/br_input.c           |  31 +-
 net/bridge/br_mrp.c             |  19 +-
 net/bridge/br_netlink.c         | 126 ++++-
 net/bridge/br_private.h         |  82 ++-
 net/bridge/br_private_cfm.h     | 242 +++++++++
 15 files changed, 2326 insertions(+), 21 deletions(-)
 create mode 100644 include/uapi/linux/cfm_bridge.h
 create mode 100644 net/bridge/br_cfm.c
 create mode 100644 net/bridge/br_cfm_netlink.c
 create mode 100644 net/bridge/br_private_cfm.h


More information about the Bridge mailing list