Re: [PATCH] iplink: add an option to set IFLA_EXT_MASK attribute

[Stephen Hemminger <stephen@networkplumber.org>]

On Wed, 3 Apr 2024 11:20:21 +0800
renmingshuai <renmingshuai@huawei.com> wrote:

> Kernel has add IFLA_EXT_MASK attribute for indicating that certain
> extended ifinfo values are requested by the user application. The ip
> link show cmd always request VFs extended ifinfo.
> 
> RTM_GETLINK for greater than about 220 VFs truncates IFLA_VFINFO_LIST
> due to the maximum reach of nlattr's nla_len being exceeded.
> As a result, ip link show command only show the truncated VFs info sucn as:
> 
>     #ip link show dev eth0
>     1: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 ...
>         link/ether ...
>         vf 0     link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff ...
>     Truncated VF list: eth0
> 
> Add an option to set IFLA_EXT_MASK attribute and users can choose to
> show the extended ifinfo or not.
> 
> Signed-off-by: Mingshuai Ren <renmingshuai@huawei.com>

Adding a new option with on/off seems like more than is necessary.
If we need an option it should just be one word. Any new filter should
have same conventions as existing filters.  Maybe 'novf'

And it looks like not sending IFLA_EXT_MASK will break the changes
made for the link filter already done for VF's.