Re: kern/39424 (SIOCGIFFLAGS ioctl(2) from 4.0 does not work under compat netbsd32)

[Nicolas Joly <njoly%pasteur.fr@localhost>]

On Sat, Dec 05, 2009 at 10:22:23PM +0000, Christos Zoulas wrote:
> In article <5470.1260044119%splode.eterna.com.au@localhost>,
> matthew green  <mrg%eterna.com.au@localhost> wrote:
> >
> >   On Dec 5,  8:41am, mrg%eterna.com.au@localhost (matthew green) wrote:
> >   -- Subject: re: kern/39424 (SIOCGIFFLAGS ioctl(2) from 4.0 does not work 
> > unde
> >   
> >   | 
> >   | my guess is that this commit is the problem:
> >   | 
> >   |         
> > http://mail-index.netbsd.org/source-changes/2007/05/29/msg186117.html
> >   | 
> >   | it changed the size of struct ifreq, pushing the ifru_flags flags 
> > further
> >   | into memory by sizeof(struct sockaddr_storage).
> >   | 
> >   | christos?  the comment says it should be backwrds compatible.
> >   
> >   Yes, the code is supposed to be backwards compatible by checking the
> >type/size
> >   of the ioctl and emulating it.
> >
> >i don't see any references to "oifreq" in sys/compat/netbsd32.
> >
> >can you have a look at this please?
> 
> Sure, can njoly provide an example binary for me to test?

Here it is. Attached sample code and corresponding NetBSD/i386 4.0.1
binary which exhibit the problem on a -current amd64 machine.

njoly@nicodeme [netbsd/ioctls]> ifconfig lo0 | grep flags
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 33648

njoly@nicodeme [netbsd/ioctls]> file siocgifflags
siocgifflags: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), 
dynamically linked (uses shared libs), for NetBSD 4.0, not stripped
njoly@nicodeme [netbsd/ioctls]> ./siocgifflags
lo0 0x52c4

njoly@nicodeme [netbsd/ioctls]> file siocgifflags
siocgifflags: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), 
dynamically linked (uses shared libs), for NetBSD 5.99.22, not stripped
njoly@nicodeme [netbsd/ioctls]> ./siocgifflags
lo0 0x8049

Thanks for looking into it.

-- 
Nicolas Joly

Biological Software and Databanks.
Institut Pasteur, Paris.

#include <arpa/inet.h>
#include <net/if.h>

#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/types.h>

#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

int main() {
  int res, fd;
  struct ifreq ifr;

  fd = socket(AF_INET, SOCK_DGRAM, 0);
  if (fd == -1)
    err(1, "socket failed");

  sprintf(ifr.ifr_name, "lo0");
  res = ioctl(fd, SIOCGIFFLAGS, &ifr);
  if (res == -1)
    err(1, "ioctl failed");

  printf("%s 0x%hx\n", ifr.ifr_name, ifr.ifr_flags);

  res = close(fd);
  if (res == -1)
    err(1, "close failed");

  return 0; }

Attachment: siocgifflags
Description: Binary data