Re: COMPAT_50 vs NET_RT_IFLIST

[Roy Marples <roy%marples.name@localhost>]

On 25/04/2019 16:08, Mouse wrote:
> I have, at work, a program, designed and written under 5.2, that uses
> sysctl on <CTL_NET, PF_ROUTE, 0, 0, NET_RT_IFLIST, 0> to get a list of
> network interfaces, which it then walks looking for things.  (It's part
> of a turnkey system.)
>
> I just now tried running this, with the associated 5.2 userland
> fragments, under an 8.0 kernel (I just replaced the 5.2 kernel with an
> 8.0 kernel on the turnkey system, the idea being to get 8.0's hardware
> support).  It fails, complaining about RTM_IFINFO blobs with RTA_IFP
> set overrunning available space and about blob version numbers being 4
> rather than 3.
>
> Is this expected?  Does COMPAT_50 not extend to this operation?  Or am
> I doing something wrong?
>
> I can show exact code if it would help, but before throwing that at
> people I thought I'd first ask if it's even supposed to work.

Sounds like you didn't compare rtm_version with RTM_VERSION.
See here in libc:
https://nxr.netbsd.org/xref/src/lib/libc/net/getifaddrs.c#106

Roy