Re: COMPAT_50 vs NET_RT_IFLIST

[Paul Goyette <paul%whooppee.com@localhost>]

On Fri, 26 Apr 2019, Paul Goyette wrote:

> On Thu, 25 Apr 2019, Mouse wrote:
>
> > > > > I have, at work, a program, designed and written under 5.2 [...].
> > > > > I just now tried running this, with the associated 5.2 userland
> > > > > fragments, under an 8.0 kernel [...].
> > > Let me know if there's any way I can help.
> >
> > About all I can think of at the moment would be to try 5.2 userland
> > with an 8.0 kernel, with a particular focus on network interfaces
> > (things like ifconfig -l, ifconfig -au, etc).  Either replace a 5.2
> > system's kernel with an 8.0 kernel or run a 5.2 userland chrooted on an
> > 8.0 system, those are how I'd try it.
> >
> > I don't _think_ anything I've done to the system is relevant here, but
> > it would be nice to have that confirmed-or-refuted before I (or anyone
> > else  for that matter) starts chasing after it.  The turnkey system in
> > question does require some changes in order to run, and it's possible,
> > albeit unlikely, that something else slipped in.
> >
> > I'm going to try to find the time to pull over completely stock 5.2 and
> > try that, but (a) it may take some time for me to scrape up the round
> > tuits for that and (b) relatively independent attempts to reproduce it
> > would be nice in any case.
>
> Well, I'm not super-familiar with setting up test environments using
> chroot, but I was unable to get a qemu install of 5.2 (seems that
> recent qemu doesn't deal well with piixide driver).  So I created a
> new directory, and unpacked the 5.2 base.tgz distribution set in it.
>
> I then did a chroot to the new directory, and tried to run ifconfig.
> The results are not what I expected.  First, I verified that I had
> all the right pieces inside the chroot directory - everything looks
> good - at least its all from the right year!
>
> # ls -l /sbin/ifconfig
> -r-xr-xr-x  1 0  20  114557 Nov 28  2012 /sbin/ifconfig
> # ldd /sbin/ifconfig
> /sbin/ifconfig:
>        -lutil.7 => /lib/libutil.so.7
>        -lc.12 => /lib/libc.so.12
>        -lprop.0 => /lib/libprop.so.0
> # ls -l /lib/libutil.so*
> lrwxrwxr-x  1 0  20     15 Nov 28  2012 /lib/libutil.so -> libutil.so.7.15
> lrwxrwxr-x  1 0  20     15 Nov 28  2012 /lib/libutil.so.7 -> libutil.so.7.15
> -r--r--r--  1 0  20  96585 Nov 28  2012 /lib/libutil.so.7.15
> # ls -l /lib/libc.so*
> lrwxrwxr-x  1 0  20       14 Nov 28  2012 /lib/libc.so -> libc.so.12.164
> lrwxrwxr-x  1 0  20       14 Nov 28  2012 /lib/libc.so.12 -> libc.so.12.164
> -r--r--r--  1 0  20  1317667 Nov 28  2012 /lib/libc.so.12.164
> # ls -l /lib/libprop*
> lrwxrwxr-x  1 0  20     14 Nov 28  2012 /lib/libprop.so -> libprop.so.0.7
> lrwxrwxr-x  1 0  20     14 Nov 28  2012 /lib/libprop.so.0 -> libprop.so.0.7
> -r--r--r--  1 0  20  82138 Nov 28  2012 /lib/libprop.so.0.7
>
>
> But, ifconfig fails to run:
>
> # ifconfig -l
> ifconfig: getifaddrs: No such file or directory
> # ifconfig -a
> ifconfig: getifaddrs: No such file or directory
>
>
> FWIW, this is running on a -current host (8.99.37, from yesterday), and
> with the compat_50 (and above) modules loaded.
>
> # modstat | grep compat
> compat_50        exec     filesys  -        0       - compat_60
> compat_60        exec     filesys  a        1       - compat_70
> compat_70        exec     filesys  a        1       - compat_80
> compat_80        exec     filesys  a        1       - -
> compat_util      misc     builtin  -        0       - -
> # uname -a
> NetBSD speedy.whooppee.com 8.99.37 NetBSD 8.99.37 (SPEEDY 2019-04-24 23:45:06 
> UTC) #0: Thu Apr 25 09:00:09 UTC 2019 
> paul%speedy.whooppee.com@localhost:/build/netbsd-local/obj/amd64/sys/arch/amd64/compile/SPEEDY 
> amd64

Digging just a little bit deeper with ktrace/kdump, I find

  7806      1 ifconfig CALL  __sysctl(0x7f7fff5d66d0,6,0,0x7f7fff5d66e8,0,0)
  7806      1 ifconfig RET   __sysctl -1 errno 2 No such file or directory
  7806      1 ifconfig CALL  write(2,0x7f7fff5d5ce0,0xa)
  7806      1 ifconfig GIO   fd 2 wrote 10 bytes
       "ifconfig: "
  7806      1 ifconfig RET   write 10/0xa
  7806      1 ifconfig CALL  write(2,0x7f7fff5d5dc0,0xa)
  7806      1 ifconfig GIO   fd 2 wrote 10 bytes
       "getifaddrs"
  7806      1 ifconfig RET   write 10/0xa
  7806      1 ifconfig CALL  write(2,0x774133de753f,2)
  7806      1 ifconfig GIO   fd 2 wrote 2 bytes
       ": "
  7806      1 ifconfig RET   write 2
  7806      1 ifconfig CALL  issetugid
  7806      1 ifconfig RET   issetugid 0
  7806      1 ifconfig CALL  issetugid
  7806      1 ifconfig RET   issetugid 0
  7806      1 ifconfig CALL  open(0x7f7fff5d5900,0,0)
  7806      1 ifconfig NAMI  "/usr/share/nls/nls.alias.db"
  7806      1 ifconfig RET   open -1 errno 2 No such file or directory

So looks to me like the sysctl() call is failing.



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