Re: [Qemu-devel] [PULL 4/4] net: disallow to specify multicast MAC address

[Amos Kong]

On Fri, Oct 18, 2013 at 03:35:14PM +0200, Stefan Hajnoczi wrote:
> From: Dmitry Krivenok <address@hidden>
> 
> Added explicit check of MAC address specified via macaddr option.
> Multicast MAC addresses are no longer allowed.
> This fixes bug lp#495566.
> 
> Signed-off-by: Dmitry V. Krivenok <address@hidden>
> Signed-off-by: Stefan Hajnoczi <address@hidden>
> ---
>  net/net.c  | 5 +++++
>  net/util.c | 5 +++++
>  net/util.h | 2 ++
>  3 files changed, 12 insertions(+)
> 
> diff --git a/net/net.c b/net/net.c
> index c330c9a..009dece 100644
> --- a/net/net.c
> +++ b/net/net.c
> @@ -689,6 +689,11 @@ static int net_init_nic(const NetClientOptions *opts, 
> const char *name,
>          error_report("invalid syntax for ethernet address");
>          return -1;
>      }
> +    if (nic->has_macaddr &&
> +        net_macaddr_is_multicast(nd->macaddr.a)) {
> +        error_report("NIC cannot have multicast MAC address (odd 1st byte)");
> +        return -1;
> +    }
>      qemu_macaddr_default_if_unset(&nd->macaddr);
>  
>      if (nic->has_vectors) {
> diff --git a/net/util.c b/net/util.c
> index 7e95076..0177bb3 100644
> --- a/net/util.c
> +++ b/net/util.c
> @@ -58,3 +58,8 @@ int net_parse_macaddr(uint8_t *macaddr, const char *p)
>  
>      return 0;
>  }
> +
> +bool net_macaddr_is_multicast(uint8_t *macaddr)
> +{
> +    return macaddr[0] % 2;
> +}

Duplicate, we already have is_multicast_ether_addr() in include/net/eth.h

> diff --git a/net/util.h b/net/util.h
> index 10c7da9..4581cb7 100644
> --- a/net/util.h
> +++ b/net/util.h
> @@ -26,7 +26,9 @@
>  #define QEMU_NET_UTIL_H
>  
>  #include <stdint.h>
> +#include <stdbool.h>
>  
>  int net_parse_macaddr(uint8_t *macaddr, const char *p);
> +bool net_macaddr_is_multicast(uint8_t *macaddr);
>  
>  #endif /* QEMU_NET_UTIL_H */
> -- 
> 1.8.3.1
> 

-- 
                        Amos.