Re: [Qemu-devel] [PATCH v2] net/net: Change the default mac address of nic

[mike <qiudayu@linux.vnet.ibm.com>]

On 10/14/2013 03:30 PM, Mike Qiu wrote:

Sorry for the first version make a mistake of the sender.

There is no difference with v1.

Thanks
Mike
> The default mac address is 52:54:00:12:34:56 + index, this will
> cause problem that when we boot up more than one guest with all
> mac addresses unset by default, assume that each guest has one
> nic. In this situation, all the guest's nic has the same mac address.
>
> This patch is to solve this bug.
>
> Signed-off-by: Mike Qiu <qiudayu@linux.vnet.ibm.com>
> ---
>   net/net.c | 9 ++++++---
>   1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/net/net.c b/net/net.c
> index c330c9a..2796d04 100644
> --- a/net/net.c
> +++ b/net/net.c
> @@ -21,6 +21,8 @@
>    * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
>    * THE SOFTWARE.
>    */
> +#include <time.h>
> +
>   #include "config-host.h"
>
>   #include "net/net.h"
> @@ -147,12 +149,13 @@ void qemu_macaddr_default_if_unset(MACAddr *macaddr)
>
>       if (memcmp(macaddr, &zero, sizeof(zero)) != 0)
>           return;
> +    srand((unsigned)time(NULL));
>       macaddr->a[0] = 0x52;
>       macaddr->a[1] = 0x54;
>       macaddr->a[2] = 0x00;
> -    macaddr->a[3] = 0x12;
> -    macaddr->a[4] = 0x34;
> -    macaddr->a[5] = 0x56 + index++;
> +    macaddr->a[3] = rand() % 256;
> +    macaddr->a[4] = rand() % 256;
> +    macaddr->a[5] = rand() % 256 + index++;
>   }
>
>   /**