Re: SIOCGIFHWADDR support for pfinet

[Marcus Brinkmann]

At Tue, 03 Aug 2004 16:03:11 +0200,
Marco Gerards wrote:
> On debian-hurd someone noticed SIOCGIFHWADDR does not exist for
> GNU/Hurd.  I have included the required patches for the Hurd and glibc
> with this email.  Or can someone suggest a better way to read the
> hardware address?

It seems basically ok to me.  However, I think that two small changes
could/should be made.

1. Only copy dev->addr_len bytes into the user buffer.  It's best to
   give out less information than more.

2. Independent of that, do we need to check if there even is a
   hardware address?  For example, what is the dev_addr of the
   loopback interface?  How does Linux ifconfig detect that the
   loopback interface doesn't have a valid MAC?  Do we initialize it
   correctly in loopback.c and does your code deal with it in a
   compatible way?

I didn't do much to try to answer the second question, although the
answer should be readily available by looking at Linux and net-tools
source code.  Once we have determined that unconditionally copying the
dev_addr field is ok, or did an appropriate check, it can go in (with
the addr_len change mentioned above).

Thanks,
Marcus

> 2004-08-03  Marco Gerards  <metgerards@student.han.nl>
> 
>       * sysdeps/mach/hurd/bits/ioctls.h (SIOCGIFHWADDR): New macro.
> 
> 
> Index: sysdeps/mach/hurd/bits/ioctls.h
> ===================================================================
> RCS file: /cvs/glibc/libc/sysdeps/mach/hurd/bits/ioctls.h,v
> retrieving revision 1.7
> diff -u -p -u -p -r1.7 ioctls.h
> --- sysdeps/mach/hurd/bits/ioctls.h   6 Jul 2001 04:55:58 -0000       1.7
> +++ sysdeps/mach/hurd/bits/ioctls.h   3 Aug 2004 13:55:34 -0000
> @@ -226,6 +226,7 @@ enum __ioctl_datum { IOC_8, IOC_16, IOC_
>  #define      SIOCSIFADDR     _IOW('i', 12, struct ifreq)     /* set ifnet 
> address */
>  #define      OSIOCGIFADDR    _IOWR('i',13, struct ifreq)     /* get ifnet 
> address */
>  #define      SIOCGIFADDR     _IOWR('i',33, struct ifreq)     /* get ifnet 
> address */
> +#define      SIOCGIFHWADDR   _IOWR('i',39, struct ifreq)     /* get 
> hwaddress */
>  #define      SIOCSIFDSTADDR  _IOW('i', 14, struct ifreq)     /* set p-p 
> address */
>  #define      OSIOCGIFDSTADDR _IOWR('i',15, struct ifreq)     /* get p-p 
> address */
>  #define      SIOCGIFDSTADDR  _IOWR('i',34, struct ifreq)     /* get p-p 
> address */
> 
> 
> 
> 2004-08-03  Marco Gerards  <metgerards@student.han.nl>
> 
>       * iioctl.defs (iioctl_siocgifhwaddr): New RPC.
> 
> Index: iioctl.defs
> ===================================================================
> RCS file: /cvsroot/hurd/hurd/hurd/iioctl.defs,v
> retrieving revision 1.1
> diff -u -p -r1.1 iioctl.defs
> --- iioctl.defs       11 Jan 2001 22:28:29 -0000      1.1
> +++ iioctl.defs       3 Aug 2004 13:12:34 -0000
> @@ -131,7 +131,14 @@ routine iioctl_siocgifnetmask (
>       inout ifnam: ifname_t;
>       inout netmask: sockaddr_t);
>  
> -skip; skip; skip; skip; /* 38, 39, 40, 41 unused */
> +skip; /* 38 SIOCGARP -- Not implemented yet */
> +
> +routine iioctl_siocgifhwaddr (
> +     reqport: io_t;
> +     inout ifnam: ifname_t;
> +     inout netmask: sockaddr_t);
> +
> +skip; skip; /* 40, 41 unused */
>  skip; skip; skip; skip; /* 42, 43, 44, 45 unused */
>  skip; skip; skip; skip; /* 46, 47, 48, 49 unused */
>  skip; /* 50 unused */
> 
> 
> 
> 2004-08-03  Marco Gerards  <metgerards@student.han.nl>
> 
>       * iioctl-ops.c (S_iioctl_siocgifhwaddr): New function.
> 
> 
> Index: iioctl-ops.c
> ===================================================================
> RCS file: /cvsroot/hurd/hurd/pfinet/iioctl-ops.c,v
> retrieving revision 1.2
> diff -u -p -r1.2 iioctl-ops.c
> --- iioctl-ops.c      17 Jan 2001 01:37:51 -0000      1.2
> +++ iioctl-ops.c      3 Aug 2004 13:11:45 -0000
> @@ -361,3 +361,28 @@ S_iioctl_siocgifname (io_t port,
>  
>    return err;
>  }
> +
> +error_t
> +S_iioctl_siocgifhwaddr (io_t port,
> +                     ifname_t ifname,
> +                     sockaddr_t *addr)
> +{
> +  error_t err = 0;
> +  struct device *dev;
> +
> +  if (!port)
> +    return EOPNOTSUPP;
> +
> +  dev = get_dev (ifname);
> +  if (!dev)
> +    err = ENODEV;
> +  else
> +    {
> +      memcpy (addr->sa_data, dev->dev_addr, MAX_ADDR_LEN);
> +      addr->sa_family = dev->type;
> +
> +    }
> +  
> +  __mutex_unlock (&global_lock);
> +  return err;
> +}
> 
> 
> 
> _______________________________________________
> Bug-hurd mailing list
> Bug-hurd@gnu.org
> http://lists.gnu.org/mailman/listinfo/bug-hurd
>