From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=7w7+tvnW1G+Cle3enHiPY2ZUGZs43aoQoOoR2xnTfDk=; b=qQBpX7EqHscfN/xttnOIq269jQJMhj2p5YKvSz2dLaR5FXlmfk12gczTp3DWFoO/qt 7tcvyb3ikdBmtwLr802xJ1ToVZPpjfy904wMElH3hQzVccak/k+9zFg0wCTJjZddGDbB xaxkaogbPyLlh+OYjSwI4qwbzT3D9RkeKgrgC8yAmOOvLHphBHx93fBP1iK47HYk2C4Y sxipObGsP3wAE8aM/O44cj8+qn1SGc48Q7r8X79oDvMR+zpvZ3hs7eHEkMlPW1WgZ+lp FLZKWhg1+o4pMBIrH5DcZApKoxeWvWDNHxXe05FvKLWr7q07292BhPKSC9M6xOtYYb6+ wgDA== Date: Fri, 4 Sep 2020 15:44:06 -0700 From: Stephen Hemminger Message-ID: <20200904154406.4fe55b9d@hermes.lan> In-Reply-To: <20200904091527.669109-1-henrik.bjoernlund@microchip.com> References: <20200904091527.669109-1-henrik.bjoernlund@microchip.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Bridge] [PATCH RFC 0/7] net: bridge: cfm: Add support for Connectivity Fault Management(CFM) List-Id: Linux Ethernet Bridging List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Henrik Bjoernlund Cc: netdev@vger.kernel.org, bridge@lists.linux-foundation.org, linux-kernel@vger.kernel.org, UNGLinuxDriver@microchip.com, idosch@mellanox.com, jiri@mellanox.com, nikolay@nvidia.com, roopa@nvidia.com, kuba@kernel.org, Horatiu Vultur , davem@davemloft.net On Fri, 4 Sep 2020 09:15:20 +0000 Henrik Bjoernlund wrote: > Connectivity Fault Management (CFM) is defined in 802.1Q section 12.14. >=20 > 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=E2=80=99s equipment. >=20 > CFM functions are partitioned as follows: > =E2=80=94 Path discovery > =E2=80=94 Fault detection > =E2=80=94 Fault verification and isolation > =E2=80=94 Fault notification > =E2=80=94 Fault recovery >=20 > 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. >=20 > There are defined the following CFM protocol functions: > -Continuity Check > -Loopback. Currently not supported. > -Linktrace. Currently not supported. >=20 > 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 > change. >=20 > 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). >=20 > Any notification emitted by CFM from the kernel can be monitored in user > space by starting 'cfm_server' program. >=20 > 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'. >=20 > Reviewed-by: Horatiu Vultur > Signed-off-by: Henrik Bjoernlund Could this be done in userspace? It is a control plane protocol. Could it be done by using eBPF? Adding more code in bridge impacts a large number of users of Linux distros. It creates bloat and potential security vulnerabilities.