Re: [PATCH iproute2] ip link: add sub-command to view and change DSA master

On Sun,  4 Sep 2022 22:00:25 +0300
Vladimir Oltean [off-list ref] wrote:

Support the "dsa" kind of rtnl_link_ops exported by the kernel, and
export reads/writes to IFLA_DSA_MASTER.

Examples:

$ ip link set swp0 type dsa master eth1

$ ip -d link show dev swp0
    (...)
    dsa master eth0

$ ip -d -j link show swp0
[
	{
		"link": "eth1",
		"linkinfo": {
			"info_kind": "dsa",
			"info_data": {
				"master": "eth1"
			}
		},
	}
]

Note that by construction and as shown in the example, the IFLA_LINK
reported by a DSA user port is identical to what is reported through
IFLA_DSA_MASTER. However IFLA_LINK is not writable, and overloading its
meaning to make it writable would clash with other users of IFLA_LINK
(vlan etc) for which writing this property does not make sense.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---

Using the term master is an unfortunate choice.
Although it is common practice in Linux it is not part of any
current standard and goes against the Linux Foundation non-inclusive
naming policy.