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Message-ID: <a7d1ebef-7161-9ecc-09ca-83f868ff7dac@ti.com>
Date: Tue, 26 May 2020 10:12:20 -0400
From: Murali Karicheri <m-karicheri2@...com>
To: Vladimir Oltean <olteanv@...il.com>,
Vinicius Costa Gomes <vinicius.gomes@...el.com>
CC: "David S. Miller" <davem@...emloft.net>,
Jakub Kicinski <kuba@...nel.org>,
netdev <netdev@...r.kernel.org>,
lkml <linux-kernel@...r.kernel.org>, <linux-api@...r.kernel.org>,
Sekhar Nori <nsekhar@...com>,
Grygorii Strashko <grygorii.strashko@...com>
Subject: Re: [net-next RFC PATCH 00/13] net: hsr: Add PRP driver
Hi Vladimir,
On 5/25/20 5:37 PM, Vladimir Oltean wrote:
> Hi Vinicius,
>
> On Thu, 21 May 2020 at 20:33, Vinicius Costa Gomes
> <vinicius.gomes@...el.com> wrote:
>>
>> Murali Karicheri <m-karicheri2@...com> writes:
>>
>>> This RFC series add support for Parallel Redundancy Protocol (PRP)
>>> as defined in IEC-62439-3 in the kernel networking subsystem. PRP
>>> Uses a Redundancy Control Trailer (RCT) the format of which is
>>> similar to HSR Tag. This is used for implementing redundancy.
>>> RCT consists of 6 bytes similar to HSR tag and contain following
>>> fields:-
>>>
>>> - 16-bit sequence number (SeqNr);
>>> - 4-bit LAN identifier (LanId);
>>> - 12 bit frame size (LSDUsize);
>>> - 16-bit suffix (PRPsuffix).
>>>
>>> The PRPsuffix identifies PRP frames and distinguishes PRP frames
>>> from other protocols that also append a trailer to their useful
>>> data. The LSDUsize field allows the receiver to distinguish PRP
>>> frames from random, nonredundant frames as an additional check.
>>> LSDUsize is the size of the Ethernet payload inclusive of the
>>> RCT. Sequence number along with LanId is used for duplicate
>>> detection and discard.
>>>
>>> PRP node is also known as Dual Attached Node (DAN-P) since it
>>> is typically attached to two different LAN for redundancy.
>>> DAN-P duplicates each of L2 frames and send it over the two
>>> Ethernet links. Each outgoing frame is appended with RCT.
>>> Unlike HSR, these are added to the end of L2 frame and may be
>>> treated as padding by bridges and therefore would be work with
>>> traditional bridges or switches, where as HSR wouldn't as Tag
>>> is prefixed to the Ethenet frame. At the remote end, these are
>>> received and the duplicate frame is discarded before the stripped
>>> frame is send up the networking stack. Like HSR, PRP also sends
>>> periodic Supervision frames to the network. These frames are
>>> received and MAC address from the SV frames are populated in a
>>> database called Node Table. The above functions are grouped into
>>> a block called Link Redundancy Entity (LRE) in the IEC spec.
>>>
>>> As there are many similarities between HSR and PRP protocols,
>>> this patch re-use the code from HSR driver to implement PRP
>>> driver. As many part of the code can be re-used, this patch
>>> introduces a new common API definitions for both protocols and
>>> propose to obsolete the existing HSR defines in
>>> include/uapi/linux/if_link.h. New definitions are prefixed
>>> with a HSR_PRP prefix. Similarly include/uapi/linux/hsr_netlink.h
>>> is proposed to be replaced with include/uapi/linux/hsr_prp_netlink.h
>>> which also uses the HSR_PRP prefix. The netlink socket interface
>>> code is migrated (as well as the iproute2 being sent as a follow up
>>> patch) to use the new API definitions. To re-use the code,
>>> following are done as a preparatory patch before adding the PRP
>>> functionality:-
>>>
>>> - prefix all common code with hsr_prp
>>> - net/hsr -> renamed to net/hsr-prp
>>> - All common struct types, constants, functions renamed with
>>> hsr{HSR}_prp{PRP} prefix.
>>
>> I don't really like these prefixes, I am thinking of when support for
>> IEEE 802.1CB is added, do we rename this to "hsr_prp_frer"?
>>
>> And it gets even more complicated, and using 802.1CB you can configure
>> the tagging method and the stream identification function so a system
>> can interoperate in a HSR or PRP network.
>>
>
> Is it a given that 802.1CB in Linux should be implemented using an hsr
> upper device?
> 802.1CB is _much_ more flexible than both HSR and PRP. You can have
> more than 2 ports, you can have per-stream rules (each stream has its
> own sequence number), and those rules can identify the source, the
> destination, or both the source and the destination.
>
I haven't looked the spec for 802.1CB. If they re-use HSR/PRP Tag in the
L2 protocol it make sense to enhance the driver. Else I don't see any
re-use possibility. Do you know the above?
Thanks
Murali
>> So, I see this as different methods of achieving the same result, which
>> makes me think that the different "methods/types" (HSR and PRP in your
>> case) should be basically different implementations of a "struct
>> hsr_ops" interface. With this hsr_ops something like this:
>>
>> struct hsr_ops {
>> int (*handle_frame)()
>> int (*add_port)()
>> int (*remove_port)()
>> int (*setup)()
>> void (*teardown)()
>> };
>>
>>>
>>> Please review this and provide me feedback so that I can work to
>>> incorporate them and send a formal patch series for this. As this
>>> series impacts user space, I am not sure if this is the right
>>> approach to introduce a new definitions and obsolete the old
>>> API definitions for HSR. The current approach is choosen
>>> to avoid redundant code in iproute2 and in the netlink driver
>>> code (hsr_netlink.c). Other approach we discussed internally was
>>> to Keep the HSR prefix in the user space and kernel code, but
>>> live with the redundant code in the iproute2 and hsr netlink
>>> code. Would like to hear from you what is the best way to add
>>> this feature to networking core. If there is any other
>>> alternative approach possible, I would like to hear about the
>>> same.
>>
>> Why redudant code is needed in the netlink parts and in iproute2 when
>> keeping the hsr prefix?
>>
>>>
>>> The patch was tested using two TI AM57x IDK boards which are
>>> connected back to back over two CPSW ports.
>>>
>>> Script used for creating the hsr/prp interface is given below
>>> and uses the ip link command. Also provided logs from the tests
>>> I have executed for your reference.
>>>
>>> iproute2 related patches will follow soon....
>>>
>>> Murali Karicheri
>>> Texas Instruments
>>>
>>> ============ setup.sh =================================================
>>> #!/bin/sh
>>> if [ $# -lt 4 ]
>>> then
>>> echo "setup-cpsw.sh <hsr/prp> <MAC-Address of slave-A>"
>>> echo " <ip address for hsr/prp interface>"
>>> echo " <if_name of hsr/prp interface>"
>>> exit
>>> fi
>>>
>>> if [ "$1" != "hsr" ] && [ "$1" != "prp" ]
>>> then
>>> echo "use hsr or prp as first argument"
>>> exit
>>> fi
>>>
>>> if_a=eth2
>>> if_b=eth3
>>> if_name=$4
>>>
>>> ifconfig $if_a down
>>> ifconfig $if_b down
>>> ifconfig $if_a hw ether $2
>>> ifconfig $if_b hw ether $2
>>> ifconfig $if_a up
>>> ifconfig $if_b up
>>>
>>> echo "Setting up $if_name with MAC address $2 for slaves and IP address $3"
>>> echo " using $if_a and $if_b"
>>>
>>> if [ "$1" = "hsr" ]; then
>>> options="version 1"
>>> else
>>> options=""
>>> fi
>>>
>>> ip link add name $if_name type $1 slave1 $if_a slave2 $if_b supervision 0 $options
>>> ifconfig $if_name $3 up
>>> ==================================================================================
>>> PRP Logs:
>>>
>>> DUT-1 : https://pastebin.ubuntu.com/p/hhsRjTQpcr/
>>> DUT-2 : https://pastebin.ubuntu.com/p/snPFKhnpk4/
>>>
>>> HSR Logs:
>>>
>>> DUT-1 : https://pastebin.ubuntu.com/p/FZPNc6Nwdm/
>>> DUT-2 : https://pastebin.ubuntu.com/p/CtV4ZVS3Yd/
>>>
>>> Murali Karicheri (13):
>>> net: hsr: Re-use Kconfig option to support PRP
>>> net: hsr: rename hsr directory to hsr-prp to introduce PRP
>>> net: hsr: rename files to introduce PRP support
>>> net: hsr: rename hsr variable inside struct hsr_port to priv
>>> net: hsr: rename hsr_port_get_hsr() to hsr_prp_get_port()
>>> net: hsr: some renaming to introduce PRP driver support
>>> net: hsr: introduce common uapi include/definitions for HSR and PRP
>>> net: hsr: migrate HSR netlink socket code to use new common API
>>> net: hsr: move re-usable code for PRP to hsr_prp_netlink.c
>>> net: hsr: add netlink socket interface for PRP
>>> net: prp: add supervision frame generation and handling support
>>> net: prp: add packet handling support
>>> net: prp: enhance debugfs to display PRP specific info in node table
>>>
>>> MAINTAINERS | 2 +-
>>> include/uapi/linux/hsr_netlink.h | 3 +
>>> include/uapi/linux/hsr_prp_netlink.h | 50 ++
>>> include/uapi/linux/if_link.h | 19 +
>>> net/Kconfig | 2 +-
>>> net/Makefile | 2 +-
>>> net/hsr-prp/Kconfig | 37 ++
>>> net/hsr-prp/Makefile | 11 +
>>> net/hsr-prp/hsr_netlink.c | 202 +++++++
>>> net/{hsr => hsr-prp}/hsr_netlink.h | 15 +-
>>> .../hsr_prp_debugfs.c} | 82 +--
>>> net/hsr-prp/hsr_prp_device.c | 562 ++++++++++++++++++
>>> net/hsr-prp/hsr_prp_device.h | 23 +
>>> net/hsr-prp/hsr_prp_forward.c | 558 +++++++++++++++++
>>> .../hsr_prp_forward.h} | 10 +-
>>> .../hsr_prp_framereg.c} | 323 +++++-----
>>> net/hsr-prp/hsr_prp_framereg.h | 68 +++
>>> net/hsr-prp/hsr_prp_main.c | 194 ++++++
>>> net/hsr-prp/hsr_prp_main.h | 289 +++++++++
>>> net/hsr-prp/hsr_prp_netlink.c | 365 ++++++++++++
>>> net/hsr-prp/hsr_prp_netlink.h | 28 +
>>> net/hsr-prp/hsr_prp_slave.c | 222 +++++++
>>> net/hsr-prp/hsr_prp_slave.h | 37 ++
>>> net/hsr-prp/prp_netlink.c | 141 +++++
>>> net/hsr-prp/prp_netlink.h | 27 +
>>> net/hsr/Kconfig | 29 -
>>> net/hsr/Makefile | 10 -
>>> net/hsr/hsr_device.c | 509 ----------------
>>> net/hsr/hsr_device.h | 22 -
>>> net/hsr/hsr_forward.c | 379 ------------
>>> net/hsr/hsr_framereg.h | 62 --
>>> net/hsr/hsr_main.c | 154 -----
>>> net/hsr/hsr_main.h | 188 ------
>>> net/hsr/hsr_netlink.c | 514 ----------------
>>> net/hsr/hsr_slave.c | 198 ------
>>> net/hsr/hsr_slave.h | 33 -
>>> 36 files changed, 3084 insertions(+), 2286 deletions(-)
>>> create mode 100644 include/uapi/linux/hsr_prp_netlink.h
>>> create mode 100644 net/hsr-prp/Kconfig
>>> create mode 100644 net/hsr-prp/Makefile
>>> create mode 100644 net/hsr-prp/hsr_netlink.c
>>> rename net/{hsr => hsr-prp}/hsr_netlink.h (58%)
>>> rename net/{hsr/hsr_debugfs.c => hsr-prp/hsr_prp_debugfs.c} (52%)
>>> create mode 100644 net/hsr-prp/hsr_prp_device.c
>>> create mode 100644 net/hsr-prp/hsr_prp_device.h
>>> create mode 100644 net/hsr-prp/hsr_prp_forward.c
>>> rename net/{hsr/hsr_forward.h => hsr-prp/hsr_prp_forward.h} (50%)
>>> rename net/{hsr/hsr_framereg.c => hsr-prp/hsr_prp_framereg.c} (56%)
>>> create mode 100644 net/hsr-prp/hsr_prp_framereg.h
>>> create mode 100644 net/hsr-prp/hsr_prp_main.c
>>> create mode 100644 net/hsr-prp/hsr_prp_main.h
>>> create mode 100644 net/hsr-prp/hsr_prp_netlink.c
>>> create mode 100644 net/hsr-prp/hsr_prp_netlink.h
>>> create mode 100644 net/hsr-prp/hsr_prp_slave.c
>>> create mode 100644 net/hsr-prp/hsr_prp_slave.h
>>> create mode 100644 net/hsr-prp/prp_netlink.c
>>> create mode 100644 net/hsr-prp/prp_netlink.h
>>> delete mode 100644 net/hsr/Kconfig
>>> delete mode 100644 net/hsr/Makefile
>>> delete mode 100644 net/hsr/hsr_device.c
>>> delete mode 100644 net/hsr/hsr_device.h
>>> delete mode 100644 net/hsr/hsr_forward.c
>>> delete mode 100644 net/hsr/hsr_framereg.h
>>> delete mode 100644 net/hsr/hsr_main.c
>>> delete mode 100644 net/hsr/hsr_main.h
>>> delete mode 100644 net/hsr/hsr_netlink.c
>>> delete mode 100644 net/hsr/hsr_slave.c
>>> delete mode 100644 net/hsr/hsr_slave.h
>>>
>>> --
>>> 2.17.1
>>>
>>
>> --
>> Vinicius
>
> Thanks,
> -Vladimir
>
--
Murali Karicheri
Texas Instruments
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