Re: [PATCH iproute2-next v3] iproute2: Add 'netshaper' command to 'ip link' for netdev shaping

[Stephen Hemminger <stephen@networkplumber.org>]

On Sun, 24 Aug 2025 06:40:17 -0700
Erni Sri Satya Vennela <ernis@linux.microsoft.com> wrote:

> On Thu, Aug 21, 2025 at 07:12:59AM -0700, Jakub Kicinski wrote:
> > On Thu, 21 Aug 2025 04:06:07 -0700 Erni Sri Satya Vennela wrote:  
> > > > Somewhat related -- what's your take on integrating / vendoring in YNL?
> > > > mnl doesn't provide any extack support..    
> > > 
> > > I have done some tests and found that if we install pkg-config and
> > > libmnl packages beforehand. The extack error messages from the kernel
> > > are being printed to the stdout.  
> > 
> > Sorry, I wasn't very precise, it supports printing the string messages.
> > But nothing that requires actually understanding the message.
> > No bad attribute errors, no missing attribute errors, no policy errors.  
> 
> Are you referring to the following error logs from the ynl tool?
> 
> $./tools/net/ynl/pyynl/cli.py
>  --spec Documentation/netlink/specs/net_shaper.yaml
>  --do set 
>  --json '{"ifindex":'3',
> 	  "handle":{"scope": "netdev", "id":'1' },
> 	  "bw-max": 200001000 }'
> 
> Netlink error: Invalid argument
> nl_len = 92 (76) nl_flags = 0x300 nl_type = 2
>         error: -22
>         extack: {'msg': 'mana: Please use multiples of 100Mbps for
> bandwidth'}
> 
> If yes, would it be reasonable to add support in iproute2 itself for
> displaying such error logs?

other parts of iproute2 already use libmnl to display extack messages.